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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
4 * Written by Alex Tomas <alex@clusterfs.com>
5 *
6 * Architecture independence:
7 * Copyright (c) 2005, Bull S.A.
8 * Written by Pierre Peiffer <pierre.peiffer@bull.net>
9 */
10
11/*
12 * Extents support for EXT4
13 *
14 * TODO:
15 * - ext4*_error() should be used in some situations
16 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
17 * - smart tree reduction
18 */
19
20#include <linux/fs.h>
21#include <linux/time.h>
22#include <linux/jbd2.h>
23#include <linux/highuid.h>
24#include <linux/pagemap.h>
25#include <linux/quotaops.h>
26#include <linux/string.h>
27#include <linux/slab.h>
28#include <linux/uaccess.h>
29#include <linux/fiemap.h>
30#include <linux/iomap.h>
31#include <linux/sched/mm.h>
32#include "ext4_jbd2.h"
33#include "ext4_extents.h"
34#include "xattr.h"
35
36#include <trace/events/ext4.h>
37
38/*
39 * used by extent splitting.
40 */
41#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
42 due to ENOSPC */
43#define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */
44#define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */
45
46#define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
47#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
48
49static __le32 ext4_extent_block_csum(struct inode *inode,
50 struct ext4_extent_header *eh)
51{
52 struct ext4_inode_info *ei = EXT4_I(inode);
53 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
54 __u32 csum;
55
56 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
57 EXT4_EXTENT_TAIL_OFFSET(eh));
58 return cpu_to_le32(csum);
59}
60
61static int ext4_extent_block_csum_verify(struct inode *inode,
62 struct ext4_extent_header *eh)
63{
64 struct ext4_extent_tail *et;
65
66 if (!ext4_has_metadata_csum(inode->i_sb))
67 return 1;
68
69 et = find_ext4_extent_tail(eh);
70 if (et->et_checksum != ext4_extent_block_csum(inode, eh))
71 return 0;
72 return 1;
73}
74
75static void ext4_extent_block_csum_set(struct inode *inode,
76 struct ext4_extent_header *eh)
77{
78 struct ext4_extent_tail *et;
79
80 if (!ext4_has_metadata_csum(inode->i_sb))
81 return;
82
83 et = find_ext4_extent_tail(eh);
84 et->et_checksum = ext4_extent_block_csum(inode, eh);
85}
86
87static int ext4_split_extent_at(handle_t *handle,
88 struct inode *inode,
89 struct ext4_ext_path **ppath,
90 ext4_lblk_t split,
91 int split_flag,
92 int flags);
93
94static int ext4_ext_trunc_restart_fn(struct inode *inode, int *dropped)
95{
96 /*
97 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
98 * moment, get_block can be called only for blocks inside i_size since
99 * page cache has been already dropped and writes are blocked by
100 * i_rwsem. So we can safely drop the i_data_sem here.
101 */
102 BUG_ON(EXT4_JOURNAL(inode) == NULL);
103 ext4_discard_preallocations(inode, 0);
104 up_write(&EXT4_I(inode)->i_data_sem);
105 *dropped = 1;
106 return 0;
107}
108
109static void ext4_ext_drop_refs(struct ext4_ext_path *path)
110{
111 int depth, i;
112
113 if (!path)
114 return;
115 depth = path->p_depth;
116 for (i = 0; i <= depth; i++, path++) {
117 brelse(path->p_bh);
118 path->p_bh = NULL;
119 }
120}
121
122void ext4_free_ext_path(struct ext4_ext_path *path)
123{
124 ext4_ext_drop_refs(path);
125 kfree(path);
126}
127
128/*
129 * Make sure 'handle' has at least 'check_cred' credits. If not, restart
130 * transaction with 'restart_cred' credits. The function drops i_data_sem
131 * when restarting transaction and gets it after transaction is restarted.
132 *
133 * The function returns 0 on success, 1 if transaction had to be restarted,
134 * and < 0 in case of fatal error.
135 */
136int ext4_datasem_ensure_credits(handle_t *handle, struct inode *inode,
137 int check_cred, int restart_cred,
138 int revoke_cred)
139{
140 int ret;
141 int dropped = 0;
142
143 ret = ext4_journal_ensure_credits_fn(handle, check_cred, restart_cred,
144 revoke_cred, ext4_ext_trunc_restart_fn(inode, &dropped));
145 if (dropped)
146 down_write(&EXT4_I(inode)->i_data_sem);
147 return ret;
148}
149
150/*
151 * could return:
152 * - EROFS
153 * - ENOMEM
154 */
155static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
156 struct ext4_ext_path *path)
157{
158 int err = 0;
159
160 if (path->p_bh) {
161 /* path points to block */
162 BUFFER_TRACE(path->p_bh, "get_write_access");
163 err = ext4_journal_get_write_access(handle, inode->i_sb,
164 path->p_bh, EXT4_JTR_NONE);
165 /*
166 * The extent buffer's verified bit will be set again in
167 * __ext4_ext_dirty(). We could leave an inconsistent
168 * buffer if the extents updating procudure break off du
169 * to some error happens, force to check it again.
170 */
171 if (!err)
172 clear_buffer_verified(path->p_bh);
173 }
174 /* path points to leaf/index in inode body */
175 /* we use in-core data, no need to protect them */
176 return err;
177}
178
179/*
180 * could return:
181 * - EROFS
182 * - ENOMEM
183 * - EIO
184 */
185static int __ext4_ext_dirty(const char *where, unsigned int line,
186 handle_t *handle, struct inode *inode,
187 struct ext4_ext_path *path)
188{
189 int err;
190
191 WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
192 if (path->p_bh) {
193 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
194 /* path points to block */
195 err = __ext4_handle_dirty_metadata(where, line, handle,
196 inode, path->p_bh);
197 /* Extents updating done, re-set verified flag */
198 if (!err)
199 set_buffer_verified(path->p_bh);
200 } else {
201 /* path points to leaf/index in inode body */
202 err = ext4_mark_inode_dirty(handle, inode);
203 }
204 return err;
205}
206
207#define ext4_ext_dirty(handle, inode, path) \
208 __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
209
210static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
211 struct ext4_ext_path *path,
212 ext4_lblk_t block)
213{
214 if (path) {
215 int depth = path->p_depth;
216 struct ext4_extent *ex;
217
218 /*
219 * Try to predict block placement assuming that we are
220 * filling in a file which will eventually be
221 * non-sparse --- i.e., in the case of libbfd writing
222 * an ELF object sections out-of-order but in a way
223 * the eventually results in a contiguous object or
224 * executable file, or some database extending a table
225 * space file. However, this is actually somewhat
226 * non-ideal if we are writing a sparse file such as
227 * qemu or KVM writing a raw image file that is going
228 * to stay fairly sparse, since it will end up
229 * fragmenting the file system's free space. Maybe we
230 * should have some hueristics or some way to allow
231 * userspace to pass a hint to file system,
232 * especially if the latter case turns out to be
233 * common.
234 */
235 ex = path[depth].p_ext;
236 if (ex) {
237 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
238 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
239
240 if (block > ext_block)
241 return ext_pblk + (block - ext_block);
242 else
243 return ext_pblk - (ext_block - block);
244 }
245
246 /* it looks like index is empty;
247 * try to find starting block from index itself */
248 if (path[depth].p_bh)
249 return path[depth].p_bh->b_blocknr;
250 }
251
252 /* OK. use inode's group */
253 return ext4_inode_to_goal_block(inode);
254}
255
256/*
257 * Allocation for a meta data block
258 */
259static ext4_fsblk_t
260ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
261 struct ext4_ext_path *path,
262 struct ext4_extent *ex, int *err, unsigned int flags)
263{
264 ext4_fsblk_t goal, newblock;
265
266 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
267 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
268 NULL, err);
269 return newblock;
270}
271
272static inline int ext4_ext_space_block(struct inode *inode, int check)
273{
274 int size;
275
276 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
277 / sizeof(struct ext4_extent);
278#ifdef AGGRESSIVE_TEST
279 if (!check && size > 6)
280 size = 6;
281#endif
282 return size;
283}
284
285static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
286{
287 int size;
288
289 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
290 / sizeof(struct ext4_extent_idx);
291#ifdef AGGRESSIVE_TEST
292 if (!check && size > 5)
293 size = 5;
294#endif
295 return size;
296}
297
298static inline int ext4_ext_space_root(struct inode *inode, int check)
299{
300 int size;
301
302 size = sizeof(EXT4_I(inode)->i_data);
303 size -= sizeof(struct ext4_extent_header);
304 size /= sizeof(struct ext4_extent);
305#ifdef AGGRESSIVE_TEST
306 if (!check && size > 3)
307 size = 3;
308#endif
309 return size;
310}
311
312static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
313{
314 int size;
315
316 size = sizeof(EXT4_I(inode)->i_data);
317 size -= sizeof(struct ext4_extent_header);
318 size /= sizeof(struct ext4_extent_idx);
319#ifdef AGGRESSIVE_TEST
320 if (!check && size > 4)
321 size = 4;
322#endif
323 return size;
324}
325
326static inline int
327ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
328 struct ext4_ext_path **ppath, ext4_lblk_t lblk,
329 int nofail)
330{
331 struct ext4_ext_path *path = *ppath;
332 int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
333 int flags = EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO;
334
335 if (nofail)
336 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL | EXT4_EX_NOFAIL;
337
338 return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ?
339 EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
340 flags);
341}
342
343static int
344ext4_ext_max_entries(struct inode *inode, int depth)
345{
346 int max;
347
348 if (depth == ext_depth(inode)) {
349 if (depth == 0)
350 max = ext4_ext_space_root(inode, 1);
351 else
352 max = ext4_ext_space_root_idx(inode, 1);
353 } else {
354 if (depth == 0)
355 max = ext4_ext_space_block(inode, 1);
356 else
357 max = ext4_ext_space_block_idx(inode, 1);
358 }
359
360 return max;
361}
362
363static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
364{
365 ext4_fsblk_t block = ext4_ext_pblock(ext);
366 int len = ext4_ext_get_actual_len(ext);
367 ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
368
369 /*
370 * We allow neither:
371 * - zero length
372 * - overflow/wrap-around
373 */
374 if (lblock + len <= lblock)
375 return 0;
376 return ext4_inode_block_valid(inode, block, len);
377}
378
379static int ext4_valid_extent_idx(struct inode *inode,
380 struct ext4_extent_idx *ext_idx)
381{
382 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
383
384 return ext4_inode_block_valid(inode, block, 1);
385}
386
387static int ext4_valid_extent_entries(struct inode *inode,
388 struct ext4_extent_header *eh,
389 ext4_lblk_t lblk, ext4_fsblk_t *pblk,
390 int depth)
391{
392 unsigned short entries;
393 ext4_lblk_t lblock = 0;
394 ext4_lblk_t cur = 0;
395
396 if (eh->eh_entries == 0)
397 return 1;
398
399 entries = le16_to_cpu(eh->eh_entries);
400
401 if (depth == 0) {
402 /* leaf entries */
403 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
404
405 /*
406 * The logical block in the first entry should equal to
407 * the number in the index block.
408 */
409 if (depth != ext_depth(inode) &&
410 lblk != le32_to_cpu(ext->ee_block))
411 return 0;
412 while (entries) {
413 if (!ext4_valid_extent(inode, ext))
414 return 0;
415
416 /* Check for overlapping extents */
417 lblock = le32_to_cpu(ext->ee_block);
418 if (lblock < cur) {
419 *pblk = ext4_ext_pblock(ext);
420 return 0;
421 }
422 cur = lblock + ext4_ext_get_actual_len(ext);
423 ext++;
424 entries--;
425 }
426 } else {
427 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
428
429 /*
430 * The logical block in the first entry should equal to
431 * the number in the parent index block.
432 */
433 if (depth != ext_depth(inode) &&
434 lblk != le32_to_cpu(ext_idx->ei_block))
435 return 0;
436 while (entries) {
437 if (!ext4_valid_extent_idx(inode, ext_idx))
438 return 0;
439
440 /* Check for overlapping index extents */
441 lblock = le32_to_cpu(ext_idx->ei_block);
442 if (lblock < cur) {
443 *pblk = ext4_idx_pblock(ext_idx);
444 return 0;
445 }
446 ext_idx++;
447 entries--;
448 cur = lblock + 1;
449 }
450 }
451 return 1;
452}
453
454static int __ext4_ext_check(const char *function, unsigned int line,
455 struct inode *inode, struct ext4_extent_header *eh,
456 int depth, ext4_fsblk_t pblk, ext4_lblk_t lblk)
457{
458 const char *error_msg;
459 int max = 0, err = -EFSCORRUPTED;
460
461 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
462 error_msg = "invalid magic";
463 goto corrupted;
464 }
465 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
466 error_msg = "unexpected eh_depth";
467 goto corrupted;
468 }
469 if (unlikely(eh->eh_max == 0)) {
470 error_msg = "invalid eh_max";
471 goto corrupted;
472 }
473 max = ext4_ext_max_entries(inode, depth);
474 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
475 error_msg = "too large eh_max";
476 goto corrupted;
477 }
478 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
479 error_msg = "invalid eh_entries";
480 goto corrupted;
481 }
482 if (unlikely((eh->eh_entries == 0) && (depth > 0))) {
483 error_msg = "eh_entries is 0 but eh_depth is > 0";
484 goto corrupted;
485 }
486 if (!ext4_valid_extent_entries(inode, eh, lblk, &pblk, depth)) {
487 error_msg = "invalid extent entries";
488 goto corrupted;
489 }
490 if (unlikely(depth > 32)) {
491 error_msg = "too large eh_depth";
492 goto corrupted;
493 }
494 /* Verify checksum on non-root extent tree nodes */
495 if (ext_depth(inode) != depth &&
496 !ext4_extent_block_csum_verify(inode, eh)) {
497 error_msg = "extent tree corrupted";
498 err = -EFSBADCRC;
499 goto corrupted;
500 }
501 return 0;
502
503corrupted:
504 ext4_error_inode_err(inode, function, line, 0, -err,
505 "pblk %llu bad header/extent: %s - magic %x, "
506 "entries %u, max %u(%u), depth %u(%u)",
507 (unsigned long long) pblk, error_msg,
508 le16_to_cpu(eh->eh_magic),
509 le16_to_cpu(eh->eh_entries),
510 le16_to_cpu(eh->eh_max),
511 max, le16_to_cpu(eh->eh_depth), depth);
512 return err;
513}
514
515#define ext4_ext_check(inode, eh, depth, pblk) \
516 __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk), 0)
517
518int ext4_ext_check_inode(struct inode *inode)
519{
520 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
521}
522
523static void ext4_cache_extents(struct inode *inode,
524 struct ext4_extent_header *eh)
525{
526 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
527 ext4_lblk_t prev = 0;
528 int i;
529
530 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
531 unsigned int status = EXTENT_STATUS_WRITTEN;
532 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
533 int len = ext4_ext_get_actual_len(ex);
534
535 if (prev && (prev != lblk))
536 ext4_es_cache_extent(inode, prev, lblk - prev, ~0,
537 EXTENT_STATUS_HOLE);
538
539 if (ext4_ext_is_unwritten(ex))
540 status = EXTENT_STATUS_UNWRITTEN;
541 ext4_es_cache_extent(inode, lblk, len,
542 ext4_ext_pblock(ex), status);
543 prev = lblk + len;
544 }
545}
546
547static struct buffer_head *
548__read_extent_tree_block(const char *function, unsigned int line,
549 struct inode *inode, struct ext4_extent_idx *idx,
550 int depth, int flags)
551{
552 struct buffer_head *bh;
553 int err;
554 gfp_t gfp_flags = __GFP_MOVABLE | GFP_NOFS;
555 ext4_fsblk_t pblk;
556
557 if (flags & EXT4_EX_NOFAIL)
558 gfp_flags |= __GFP_NOFAIL;
559
560 pblk = ext4_idx_pblock(idx);
561 bh = sb_getblk_gfp(inode->i_sb, pblk, gfp_flags);
562 if (unlikely(!bh))
563 return ERR_PTR(-ENOMEM);
564
565 if (!bh_uptodate_or_lock(bh)) {
566 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
567 err = ext4_read_bh(bh, 0, NULL);
568 if (err < 0)
569 goto errout;
570 }
571 if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
572 return bh;
573 err = __ext4_ext_check(function, line, inode, ext_block_hdr(bh),
574 depth, pblk, le32_to_cpu(idx->ei_block));
575 if (err)
576 goto errout;
577 set_buffer_verified(bh);
578 /*
579 * If this is a leaf block, cache all of its entries
580 */
581 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
582 struct ext4_extent_header *eh = ext_block_hdr(bh);
583 ext4_cache_extents(inode, eh);
584 }
585 return bh;
586errout:
587 put_bh(bh);
588 return ERR_PTR(err);
589
590}
591
592#define read_extent_tree_block(inode, idx, depth, flags) \
593 __read_extent_tree_block(__func__, __LINE__, (inode), (idx), \
594 (depth), (flags))
595
596/*
597 * This function is called to cache a file's extent information in the
598 * extent status tree
599 */
600int ext4_ext_precache(struct inode *inode)
601{
602 struct ext4_inode_info *ei = EXT4_I(inode);
603 struct ext4_ext_path *path = NULL;
604 struct buffer_head *bh;
605 int i = 0, depth, ret = 0;
606
607 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
608 return 0; /* not an extent-mapped inode */
609
610 down_read(&ei->i_data_sem);
611 depth = ext_depth(inode);
612
613 /* Don't cache anything if there are no external extent blocks */
614 if (!depth) {
615 up_read(&ei->i_data_sem);
616 return ret;
617 }
618
619 path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
620 GFP_NOFS);
621 if (path == NULL) {
622 up_read(&ei->i_data_sem);
623 return -ENOMEM;
624 }
625
626 path[0].p_hdr = ext_inode_hdr(inode);
627 ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
628 if (ret)
629 goto out;
630 path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
631 while (i >= 0) {
632 /*
633 * If this is a leaf block or we've reached the end of
634 * the index block, go up
635 */
636 if ((i == depth) ||
637 path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
638 brelse(path[i].p_bh);
639 path[i].p_bh = NULL;
640 i--;
641 continue;
642 }
643 bh = read_extent_tree_block(inode, path[i].p_idx++,
644 depth - i - 1,
645 EXT4_EX_FORCE_CACHE);
646 if (IS_ERR(bh)) {
647 ret = PTR_ERR(bh);
648 break;
649 }
650 i++;
651 path[i].p_bh = bh;
652 path[i].p_hdr = ext_block_hdr(bh);
653 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
654 }
655 ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
656out:
657 up_read(&ei->i_data_sem);
658 ext4_free_ext_path(path);
659 return ret;
660}
661
662#ifdef EXT_DEBUG
663static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
664{
665 int k, l = path->p_depth;
666
667 ext_debug(inode, "path:");
668 for (k = 0; k <= l; k++, path++) {
669 if (path->p_idx) {
670 ext_debug(inode, " %d->%llu",
671 le32_to_cpu(path->p_idx->ei_block),
672 ext4_idx_pblock(path->p_idx));
673 } else if (path->p_ext) {
674 ext_debug(inode, " %d:[%d]%d:%llu ",
675 le32_to_cpu(path->p_ext->ee_block),
676 ext4_ext_is_unwritten(path->p_ext),
677 ext4_ext_get_actual_len(path->p_ext),
678 ext4_ext_pblock(path->p_ext));
679 } else
680 ext_debug(inode, " []");
681 }
682 ext_debug(inode, "\n");
683}
684
685static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
686{
687 int depth = ext_depth(inode);
688 struct ext4_extent_header *eh;
689 struct ext4_extent *ex;
690 int i;
691
692 if (!path)
693 return;
694
695 eh = path[depth].p_hdr;
696 ex = EXT_FIRST_EXTENT(eh);
697
698 ext_debug(inode, "Displaying leaf extents\n");
699
700 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
701 ext_debug(inode, "%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
702 ext4_ext_is_unwritten(ex),
703 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
704 }
705 ext_debug(inode, "\n");
706}
707
708static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
709 ext4_fsblk_t newblock, int level)
710{
711 int depth = ext_depth(inode);
712 struct ext4_extent *ex;
713
714 if (depth != level) {
715 struct ext4_extent_idx *idx;
716 idx = path[level].p_idx;
717 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
718 ext_debug(inode, "%d: move %d:%llu in new index %llu\n",
719 level, le32_to_cpu(idx->ei_block),
720 ext4_idx_pblock(idx), newblock);
721 idx++;
722 }
723
724 return;
725 }
726
727 ex = path[depth].p_ext;
728 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
729 ext_debug(inode, "move %d:%llu:[%d]%d in new leaf %llu\n",
730 le32_to_cpu(ex->ee_block),
731 ext4_ext_pblock(ex),
732 ext4_ext_is_unwritten(ex),
733 ext4_ext_get_actual_len(ex),
734 newblock);
735 ex++;
736 }
737}
738
739#else
740#define ext4_ext_show_path(inode, path)
741#define ext4_ext_show_leaf(inode, path)
742#define ext4_ext_show_move(inode, path, newblock, level)
743#endif
744
745/*
746 * ext4_ext_binsearch_idx:
747 * binary search for the closest index of the given block
748 * the header must be checked before calling this
749 */
750static void
751ext4_ext_binsearch_idx(struct inode *inode,
752 struct ext4_ext_path *path, ext4_lblk_t block)
753{
754 struct ext4_extent_header *eh = path->p_hdr;
755 struct ext4_extent_idx *r, *l, *m;
756
757
758 ext_debug(inode, "binsearch for %u(idx): ", block);
759
760 l = EXT_FIRST_INDEX(eh) + 1;
761 r = EXT_LAST_INDEX(eh);
762 while (l <= r) {
763 m = l + (r - l) / 2;
764 ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l,
765 le32_to_cpu(l->ei_block), m, le32_to_cpu(m->ei_block),
766 r, le32_to_cpu(r->ei_block));
767
768 if (block < le32_to_cpu(m->ei_block))
769 r = m - 1;
770 else
771 l = m + 1;
772 }
773
774 path->p_idx = l - 1;
775 ext_debug(inode, " -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
776 ext4_idx_pblock(path->p_idx));
777
778#ifdef CHECK_BINSEARCH
779 {
780 struct ext4_extent_idx *chix, *ix;
781 int k;
782
783 chix = ix = EXT_FIRST_INDEX(eh);
784 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
785 if (k != 0 && le32_to_cpu(ix->ei_block) <=
786 le32_to_cpu(ix[-1].ei_block)) {
787 printk(KERN_DEBUG "k=%d, ix=0x%p, "
788 "first=0x%p\n", k,
789 ix, EXT_FIRST_INDEX(eh));
790 printk(KERN_DEBUG "%u <= %u\n",
791 le32_to_cpu(ix->ei_block),
792 le32_to_cpu(ix[-1].ei_block));
793 }
794 BUG_ON(k && le32_to_cpu(ix->ei_block)
795 <= le32_to_cpu(ix[-1].ei_block));
796 if (block < le32_to_cpu(ix->ei_block))
797 break;
798 chix = ix;
799 }
800 BUG_ON(chix != path->p_idx);
801 }
802#endif
803
804}
805
806/*
807 * ext4_ext_binsearch:
808 * binary search for closest extent of the given block
809 * the header must be checked before calling this
810 */
811static void
812ext4_ext_binsearch(struct inode *inode,
813 struct ext4_ext_path *path, ext4_lblk_t block)
814{
815 struct ext4_extent_header *eh = path->p_hdr;
816 struct ext4_extent *r, *l, *m;
817
818 if (eh->eh_entries == 0) {
819 /*
820 * this leaf is empty:
821 * we get such a leaf in split/add case
822 */
823 return;
824 }
825
826 ext_debug(inode, "binsearch for %u: ", block);
827
828 l = EXT_FIRST_EXTENT(eh) + 1;
829 r = EXT_LAST_EXTENT(eh);
830
831 while (l <= r) {
832 m = l + (r - l) / 2;
833 ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l,
834 le32_to_cpu(l->ee_block), m, le32_to_cpu(m->ee_block),
835 r, le32_to_cpu(r->ee_block));
836
837 if (block < le32_to_cpu(m->ee_block))
838 r = m - 1;
839 else
840 l = m + 1;
841 }
842
843 path->p_ext = l - 1;
844 ext_debug(inode, " -> %d:%llu:[%d]%d ",
845 le32_to_cpu(path->p_ext->ee_block),
846 ext4_ext_pblock(path->p_ext),
847 ext4_ext_is_unwritten(path->p_ext),
848 ext4_ext_get_actual_len(path->p_ext));
849
850#ifdef CHECK_BINSEARCH
851 {
852 struct ext4_extent *chex, *ex;
853 int k;
854
855 chex = ex = EXT_FIRST_EXTENT(eh);
856 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
857 BUG_ON(k && le32_to_cpu(ex->ee_block)
858 <= le32_to_cpu(ex[-1].ee_block));
859 if (block < le32_to_cpu(ex->ee_block))
860 break;
861 chex = ex;
862 }
863 BUG_ON(chex != path->p_ext);
864 }
865#endif
866
867}
868
869void ext4_ext_tree_init(handle_t *handle, struct inode *inode)
870{
871 struct ext4_extent_header *eh;
872
873 eh = ext_inode_hdr(inode);
874 eh->eh_depth = 0;
875 eh->eh_entries = 0;
876 eh->eh_magic = EXT4_EXT_MAGIC;
877 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
878 eh->eh_generation = 0;
879 ext4_mark_inode_dirty(handle, inode);
880}
881
882struct ext4_ext_path *
883ext4_find_extent(struct inode *inode, ext4_lblk_t block,
884 struct ext4_ext_path **orig_path, int flags)
885{
886 struct ext4_extent_header *eh;
887 struct buffer_head *bh;
888 struct ext4_ext_path *path = orig_path ? *orig_path : NULL;
889 short int depth, i, ppos = 0;
890 int ret;
891 gfp_t gfp_flags = GFP_NOFS;
892
893 if (flags & EXT4_EX_NOFAIL)
894 gfp_flags |= __GFP_NOFAIL;
895
896 eh = ext_inode_hdr(inode);
897 depth = ext_depth(inode);
898 if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) {
899 EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d",
900 depth);
901 ret = -EFSCORRUPTED;
902 goto err;
903 }
904
905 if (path) {
906 ext4_ext_drop_refs(path);
907 if (depth > path[0].p_maxdepth) {
908 kfree(path);
909 *orig_path = path = NULL;
910 }
911 }
912 if (!path) {
913 /* account possible depth increase */
914 path = kcalloc(depth + 2, sizeof(struct ext4_ext_path),
915 gfp_flags);
916 if (unlikely(!path))
917 return ERR_PTR(-ENOMEM);
918 path[0].p_maxdepth = depth + 1;
919 }
920 path[0].p_hdr = eh;
921 path[0].p_bh = NULL;
922
923 i = depth;
924 if (!(flags & EXT4_EX_NOCACHE) && depth == 0)
925 ext4_cache_extents(inode, eh);
926 /* walk through the tree */
927 while (i) {
928 ext_debug(inode, "depth %d: num %d, max %d\n",
929 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
930
931 ext4_ext_binsearch_idx(inode, path + ppos, block);
932 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
933 path[ppos].p_depth = i;
934 path[ppos].p_ext = NULL;
935
936 bh = read_extent_tree_block(inode, path[ppos].p_idx, --i, flags);
937 if (IS_ERR(bh)) {
938 ret = PTR_ERR(bh);
939 goto err;
940 }
941
942 eh = ext_block_hdr(bh);
943 ppos++;
944 path[ppos].p_bh = bh;
945 path[ppos].p_hdr = eh;
946 }
947
948 path[ppos].p_depth = i;
949 path[ppos].p_ext = NULL;
950 path[ppos].p_idx = NULL;
951
952 /* find extent */
953 ext4_ext_binsearch(inode, path + ppos, block);
954 /* if not an empty leaf */
955 if (path[ppos].p_ext)
956 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
957
958 ext4_ext_show_path(inode, path);
959
960 return path;
961
962err:
963 ext4_free_ext_path(path);
964 if (orig_path)
965 *orig_path = NULL;
966 return ERR_PTR(ret);
967}
968
969/*
970 * ext4_ext_insert_index:
971 * insert new index [@logical;@ptr] into the block at @curp;
972 * check where to insert: before @curp or after @curp
973 */
974static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
975 struct ext4_ext_path *curp,
976 int logical, ext4_fsblk_t ptr)
977{
978 struct ext4_extent_idx *ix;
979 int len, err;
980
981 err = ext4_ext_get_access(handle, inode, curp);
982 if (err)
983 return err;
984
985 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
986 EXT4_ERROR_INODE(inode,
987 "logical %d == ei_block %d!",
988 logical, le32_to_cpu(curp->p_idx->ei_block));
989 return -EFSCORRUPTED;
990 }
991
992 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
993 >= le16_to_cpu(curp->p_hdr->eh_max))) {
994 EXT4_ERROR_INODE(inode,
995 "eh_entries %d >= eh_max %d!",
996 le16_to_cpu(curp->p_hdr->eh_entries),
997 le16_to_cpu(curp->p_hdr->eh_max));
998 return -EFSCORRUPTED;
999 }
1000
1001 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
1002 /* insert after */
1003 ext_debug(inode, "insert new index %d after: %llu\n",
1004 logical, ptr);
1005 ix = curp->p_idx + 1;
1006 } else {
1007 /* insert before */
1008 ext_debug(inode, "insert new index %d before: %llu\n",
1009 logical, ptr);
1010 ix = curp->p_idx;
1011 }
1012
1013 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
1014 BUG_ON(len < 0);
1015 if (len > 0) {
1016 ext_debug(inode, "insert new index %d: "
1017 "move %d indices from 0x%p to 0x%p\n",
1018 logical, len, ix, ix + 1);
1019 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
1020 }
1021
1022 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
1023 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
1024 return -EFSCORRUPTED;
1025 }
1026
1027 ix->ei_block = cpu_to_le32(logical);
1028 ext4_idx_store_pblock(ix, ptr);
1029 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
1030
1031 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
1032 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
1033 return -EFSCORRUPTED;
1034 }
1035
1036 err = ext4_ext_dirty(handle, inode, curp);
1037 ext4_std_error(inode->i_sb, err);
1038
1039 return err;
1040}
1041
1042/*
1043 * ext4_ext_split:
1044 * inserts new subtree into the path, using free index entry
1045 * at depth @at:
1046 * - allocates all needed blocks (new leaf and all intermediate index blocks)
1047 * - makes decision where to split
1048 * - moves remaining extents and index entries (right to the split point)
1049 * into the newly allocated blocks
1050 * - initializes subtree
1051 */
1052static int ext4_ext_split(handle_t *handle, struct inode *inode,
1053 unsigned int flags,
1054 struct ext4_ext_path *path,
1055 struct ext4_extent *newext, int at)
1056{
1057 struct buffer_head *bh = NULL;
1058 int depth = ext_depth(inode);
1059 struct ext4_extent_header *neh;
1060 struct ext4_extent_idx *fidx;
1061 int i = at, k, m, a;
1062 ext4_fsblk_t newblock, oldblock;
1063 __le32 border;
1064 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1065 gfp_t gfp_flags = GFP_NOFS;
1066 int err = 0;
1067 size_t ext_size = 0;
1068
1069 if (flags & EXT4_EX_NOFAIL)
1070 gfp_flags |= __GFP_NOFAIL;
1071
1072 /* make decision: where to split? */
1073 /* FIXME: now decision is simplest: at current extent */
1074
1075 /* if current leaf will be split, then we should use
1076 * border from split point */
1077 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1078 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1079 return -EFSCORRUPTED;
1080 }
1081 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1082 border = path[depth].p_ext[1].ee_block;
1083 ext_debug(inode, "leaf will be split."
1084 " next leaf starts at %d\n",
1085 le32_to_cpu(border));
1086 } else {
1087 border = newext->ee_block;
1088 ext_debug(inode, "leaf will be added."
1089 " next leaf starts at %d\n",
1090 le32_to_cpu(border));
1091 }
1092
1093 /*
1094 * If error occurs, then we break processing
1095 * and mark filesystem read-only. index won't
1096 * be inserted and tree will be in consistent
1097 * state. Next mount will repair buffers too.
1098 */
1099
1100 /*
1101 * Get array to track all allocated blocks.
1102 * We need this to handle errors and free blocks
1103 * upon them.
1104 */
1105 ablocks = kcalloc(depth, sizeof(ext4_fsblk_t), gfp_flags);
1106 if (!ablocks)
1107 return -ENOMEM;
1108
1109 /* allocate all needed blocks */
1110 ext_debug(inode, "allocate %d blocks for indexes/leaf\n", depth - at);
1111 for (a = 0; a < depth - at; a++) {
1112 newblock = ext4_ext_new_meta_block(handle, inode, path,
1113 newext, &err, flags);
1114 if (newblock == 0)
1115 goto cleanup;
1116 ablocks[a] = newblock;
1117 }
1118
1119 /* initialize new leaf */
1120 newblock = ablocks[--a];
1121 if (unlikely(newblock == 0)) {
1122 EXT4_ERROR_INODE(inode, "newblock == 0!");
1123 err = -EFSCORRUPTED;
1124 goto cleanup;
1125 }
1126 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1127 if (unlikely(!bh)) {
1128 err = -ENOMEM;
1129 goto cleanup;
1130 }
1131 lock_buffer(bh);
1132
1133 err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1134 EXT4_JTR_NONE);
1135 if (err)
1136 goto cleanup;
1137
1138 neh = ext_block_hdr(bh);
1139 neh->eh_entries = 0;
1140 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1141 neh->eh_magic = EXT4_EXT_MAGIC;
1142 neh->eh_depth = 0;
1143 neh->eh_generation = 0;
1144
1145 /* move remainder of path[depth] to the new leaf */
1146 if (unlikely(path[depth].p_hdr->eh_entries !=
1147 path[depth].p_hdr->eh_max)) {
1148 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1149 path[depth].p_hdr->eh_entries,
1150 path[depth].p_hdr->eh_max);
1151 err = -EFSCORRUPTED;
1152 goto cleanup;
1153 }
1154 /* start copy from next extent */
1155 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1156 ext4_ext_show_move(inode, path, newblock, depth);
1157 if (m) {
1158 struct ext4_extent *ex;
1159 ex = EXT_FIRST_EXTENT(neh);
1160 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1161 le16_add_cpu(&neh->eh_entries, m);
1162 }
1163
1164 /* zero out unused area in the extent block */
1165 ext_size = sizeof(struct ext4_extent_header) +
1166 sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries);
1167 memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
1168 ext4_extent_block_csum_set(inode, neh);
1169 set_buffer_uptodate(bh);
1170 unlock_buffer(bh);
1171
1172 err = ext4_handle_dirty_metadata(handle, inode, bh);
1173 if (err)
1174 goto cleanup;
1175 brelse(bh);
1176 bh = NULL;
1177
1178 /* correct old leaf */
1179 if (m) {
1180 err = ext4_ext_get_access(handle, inode, path + depth);
1181 if (err)
1182 goto cleanup;
1183 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1184 err = ext4_ext_dirty(handle, inode, path + depth);
1185 if (err)
1186 goto cleanup;
1187
1188 }
1189
1190 /* create intermediate indexes */
1191 k = depth - at - 1;
1192 if (unlikely(k < 0)) {
1193 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1194 err = -EFSCORRUPTED;
1195 goto cleanup;
1196 }
1197 if (k)
1198 ext_debug(inode, "create %d intermediate indices\n", k);
1199 /* insert new index into current index block */
1200 /* current depth stored in i var */
1201 i = depth - 1;
1202 while (k--) {
1203 oldblock = newblock;
1204 newblock = ablocks[--a];
1205 bh = sb_getblk(inode->i_sb, newblock);
1206 if (unlikely(!bh)) {
1207 err = -ENOMEM;
1208 goto cleanup;
1209 }
1210 lock_buffer(bh);
1211
1212 err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1213 EXT4_JTR_NONE);
1214 if (err)
1215 goto cleanup;
1216
1217 neh = ext_block_hdr(bh);
1218 neh->eh_entries = cpu_to_le16(1);
1219 neh->eh_magic = EXT4_EXT_MAGIC;
1220 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1221 neh->eh_depth = cpu_to_le16(depth - i);
1222 neh->eh_generation = 0;
1223 fidx = EXT_FIRST_INDEX(neh);
1224 fidx->ei_block = border;
1225 ext4_idx_store_pblock(fidx, oldblock);
1226
1227 ext_debug(inode, "int.index at %d (block %llu): %u -> %llu\n",
1228 i, newblock, le32_to_cpu(border), oldblock);
1229
1230 /* move remainder of path[i] to the new index block */
1231 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1232 EXT_LAST_INDEX(path[i].p_hdr))) {
1233 EXT4_ERROR_INODE(inode,
1234 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1235 le32_to_cpu(path[i].p_ext->ee_block));
1236 err = -EFSCORRUPTED;
1237 goto cleanup;
1238 }
1239 /* start copy indexes */
1240 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1241 ext_debug(inode, "cur 0x%p, last 0x%p\n", path[i].p_idx,
1242 EXT_MAX_INDEX(path[i].p_hdr));
1243 ext4_ext_show_move(inode, path, newblock, i);
1244 if (m) {
1245 memmove(++fidx, path[i].p_idx,
1246 sizeof(struct ext4_extent_idx) * m);
1247 le16_add_cpu(&neh->eh_entries, m);
1248 }
1249 /* zero out unused area in the extent block */
1250 ext_size = sizeof(struct ext4_extent_header) +
1251 (sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries));
1252 memset(bh->b_data + ext_size, 0,
1253 inode->i_sb->s_blocksize - ext_size);
1254 ext4_extent_block_csum_set(inode, neh);
1255 set_buffer_uptodate(bh);
1256 unlock_buffer(bh);
1257
1258 err = ext4_handle_dirty_metadata(handle, inode, bh);
1259 if (err)
1260 goto cleanup;
1261 brelse(bh);
1262 bh = NULL;
1263
1264 /* correct old index */
1265 if (m) {
1266 err = ext4_ext_get_access(handle, inode, path + i);
1267 if (err)
1268 goto cleanup;
1269 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1270 err = ext4_ext_dirty(handle, inode, path + i);
1271 if (err)
1272 goto cleanup;
1273 }
1274
1275 i--;
1276 }
1277
1278 /* insert new index */
1279 err = ext4_ext_insert_index(handle, inode, path + at,
1280 le32_to_cpu(border), newblock);
1281
1282cleanup:
1283 if (bh) {
1284 if (buffer_locked(bh))
1285 unlock_buffer(bh);
1286 brelse(bh);
1287 }
1288
1289 if (err) {
1290 /* free all allocated blocks in error case */
1291 for (i = 0; i < depth; i++) {
1292 if (!ablocks[i])
1293 continue;
1294 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1295 EXT4_FREE_BLOCKS_METADATA);
1296 }
1297 }
1298 kfree(ablocks);
1299
1300 return err;
1301}
1302
1303/*
1304 * ext4_ext_grow_indepth:
1305 * implements tree growing procedure:
1306 * - allocates new block
1307 * - moves top-level data (index block or leaf) into the new block
1308 * - initializes new top-level, creating index that points to the
1309 * just created block
1310 */
1311static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1312 unsigned int flags)
1313{
1314 struct ext4_extent_header *neh;
1315 struct buffer_head *bh;
1316 ext4_fsblk_t newblock, goal = 0;
1317 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
1318 int err = 0;
1319 size_t ext_size = 0;
1320
1321 /* Try to prepend new index to old one */
1322 if (ext_depth(inode))
1323 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
1324 if (goal > le32_to_cpu(es->s_first_data_block)) {
1325 flags |= EXT4_MB_HINT_TRY_GOAL;
1326 goal--;
1327 } else
1328 goal = ext4_inode_to_goal_block(inode);
1329 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
1330 NULL, &err);
1331 if (newblock == 0)
1332 return err;
1333
1334 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1335 if (unlikely(!bh))
1336 return -ENOMEM;
1337 lock_buffer(bh);
1338
1339 err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1340 EXT4_JTR_NONE);
1341 if (err) {
1342 unlock_buffer(bh);
1343 goto out;
1344 }
1345
1346 ext_size = sizeof(EXT4_I(inode)->i_data);
1347 /* move top-level index/leaf into new block */
1348 memmove(bh->b_data, EXT4_I(inode)->i_data, ext_size);
1349 /* zero out unused area in the extent block */
1350 memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
1351
1352 /* set size of new block */
1353 neh = ext_block_hdr(bh);
1354 /* old root could have indexes or leaves
1355 * so calculate e_max right way */
1356 if (ext_depth(inode))
1357 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1358 else
1359 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1360 neh->eh_magic = EXT4_EXT_MAGIC;
1361 ext4_extent_block_csum_set(inode, neh);
1362 set_buffer_uptodate(bh);
1363 set_buffer_verified(bh);
1364 unlock_buffer(bh);
1365
1366 err = ext4_handle_dirty_metadata(handle, inode, bh);
1367 if (err)
1368 goto out;
1369
1370 /* Update top-level index: num,max,pointer */
1371 neh = ext_inode_hdr(inode);
1372 neh->eh_entries = cpu_to_le16(1);
1373 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1374 if (neh->eh_depth == 0) {
1375 /* Root extent block becomes index block */
1376 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1377 EXT_FIRST_INDEX(neh)->ei_block =
1378 EXT_FIRST_EXTENT(neh)->ee_block;
1379 }
1380 ext_debug(inode, "new root: num %d(%d), lblock %d, ptr %llu\n",
1381 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1382 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1383 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1384
1385 le16_add_cpu(&neh->eh_depth, 1);
1386 err = ext4_mark_inode_dirty(handle, inode);
1387out:
1388 brelse(bh);
1389
1390 return err;
1391}
1392
1393/*
1394 * ext4_ext_create_new_leaf:
1395 * finds empty index and adds new leaf.
1396 * if no free index is found, then it requests in-depth growing.
1397 */
1398static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1399 unsigned int mb_flags,
1400 unsigned int gb_flags,
1401 struct ext4_ext_path **ppath,
1402 struct ext4_extent *newext)
1403{
1404 struct ext4_ext_path *path = *ppath;
1405 struct ext4_ext_path *curp;
1406 int depth, i, err = 0;
1407
1408repeat:
1409 i = depth = ext_depth(inode);
1410
1411 /* walk up to the tree and look for free index entry */
1412 curp = path + depth;
1413 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1414 i--;
1415 curp--;
1416 }
1417
1418 /* we use already allocated block for index block,
1419 * so subsequent data blocks should be contiguous */
1420 if (EXT_HAS_FREE_INDEX(curp)) {
1421 /* if we found index with free entry, then use that
1422 * entry: create all needed subtree and add new leaf */
1423 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
1424 if (err)
1425 goto out;
1426
1427 /* refill path */
1428 path = ext4_find_extent(inode,
1429 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1430 ppath, gb_flags);
1431 if (IS_ERR(path))
1432 err = PTR_ERR(path);
1433 } else {
1434 /* tree is full, time to grow in depth */
1435 err = ext4_ext_grow_indepth(handle, inode, mb_flags);
1436 if (err)
1437 goto out;
1438
1439 /* refill path */
1440 path = ext4_find_extent(inode,
1441 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1442 ppath, gb_flags);
1443 if (IS_ERR(path)) {
1444 err = PTR_ERR(path);
1445 goto out;
1446 }
1447
1448 /*
1449 * only first (depth 0 -> 1) produces free space;
1450 * in all other cases we have to split the grown tree
1451 */
1452 depth = ext_depth(inode);
1453 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1454 /* now we need to split */
1455 goto repeat;
1456 }
1457 }
1458
1459out:
1460 return err;
1461}
1462
1463/*
1464 * search the closest allocated block to the left for *logical
1465 * and returns it at @logical + it's physical address at @phys
1466 * if *logical is the smallest allocated block, the function
1467 * returns 0 at @phys
1468 * return value contains 0 (success) or error code
1469 */
1470static int ext4_ext_search_left(struct inode *inode,
1471 struct ext4_ext_path *path,
1472 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1473{
1474 struct ext4_extent_idx *ix;
1475 struct ext4_extent *ex;
1476 int depth, ee_len;
1477
1478 if (unlikely(path == NULL)) {
1479 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1480 return -EFSCORRUPTED;
1481 }
1482 depth = path->p_depth;
1483 *phys = 0;
1484
1485 if (depth == 0 && path->p_ext == NULL)
1486 return 0;
1487
1488 /* usually extent in the path covers blocks smaller
1489 * then *logical, but it can be that extent is the
1490 * first one in the file */
1491
1492 ex = path[depth].p_ext;
1493 ee_len = ext4_ext_get_actual_len(ex);
1494 if (*logical < le32_to_cpu(ex->ee_block)) {
1495 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1496 EXT4_ERROR_INODE(inode,
1497 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1498 *logical, le32_to_cpu(ex->ee_block));
1499 return -EFSCORRUPTED;
1500 }
1501 while (--depth >= 0) {
1502 ix = path[depth].p_idx;
1503 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1504 EXT4_ERROR_INODE(inode,
1505 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1506 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1507 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block),
1508 depth);
1509 return -EFSCORRUPTED;
1510 }
1511 }
1512 return 0;
1513 }
1514
1515 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1516 EXT4_ERROR_INODE(inode,
1517 "logical %d < ee_block %d + ee_len %d!",
1518 *logical, le32_to_cpu(ex->ee_block), ee_len);
1519 return -EFSCORRUPTED;
1520 }
1521
1522 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1523 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1524 return 0;
1525}
1526
1527/*
1528 * Search the closest allocated block to the right for *logical
1529 * and returns it at @logical + it's physical address at @phys.
1530 * If not exists, return 0 and @phys is set to 0. We will return
1531 * 1 which means we found an allocated block and ret_ex is valid.
1532 * Or return a (< 0) error code.
1533 */
1534static int ext4_ext_search_right(struct inode *inode,
1535 struct ext4_ext_path *path,
1536 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1537 struct ext4_extent *ret_ex)
1538{
1539 struct buffer_head *bh = NULL;
1540 struct ext4_extent_header *eh;
1541 struct ext4_extent_idx *ix;
1542 struct ext4_extent *ex;
1543 int depth; /* Note, NOT eh_depth; depth from top of tree */
1544 int ee_len;
1545
1546 if (unlikely(path == NULL)) {
1547 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1548 return -EFSCORRUPTED;
1549 }
1550 depth = path->p_depth;
1551 *phys = 0;
1552
1553 if (depth == 0 && path->p_ext == NULL)
1554 return 0;
1555
1556 /* usually extent in the path covers blocks smaller
1557 * then *logical, but it can be that extent is the
1558 * first one in the file */
1559
1560 ex = path[depth].p_ext;
1561 ee_len = ext4_ext_get_actual_len(ex);
1562 if (*logical < le32_to_cpu(ex->ee_block)) {
1563 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1564 EXT4_ERROR_INODE(inode,
1565 "first_extent(path[%d].p_hdr) != ex",
1566 depth);
1567 return -EFSCORRUPTED;
1568 }
1569 while (--depth >= 0) {
1570 ix = path[depth].p_idx;
1571 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1572 EXT4_ERROR_INODE(inode,
1573 "ix != EXT_FIRST_INDEX *logical %d!",
1574 *logical);
1575 return -EFSCORRUPTED;
1576 }
1577 }
1578 goto found_extent;
1579 }
1580
1581 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1582 EXT4_ERROR_INODE(inode,
1583 "logical %d < ee_block %d + ee_len %d!",
1584 *logical, le32_to_cpu(ex->ee_block), ee_len);
1585 return -EFSCORRUPTED;
1586 }
1587
1588 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1589 /* next allocated block in this leaf */
1590 ex++;
1591 goto found_extent;
1592 }
1593
1594 /* go up and search for index to the right */
1595 while (--depth >= 0) {
1596 ix = path[depth].p_idx;
1597 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1598 goto got_index;
1599 }
1600
1601 /* we've gone up to the root and found no index to the right */
1602 return 0;
1603
1604got_index:
1605 /* we've found index to the right, let's
1606 * follow it and find the closest allocated
1607 * block to the right */
1608 ix++;
1609 while (++depth < path->p_depth) {
1610 /* subtract from p_depth to get proper eh_depth */
1611 bh = read_extent_tree_block(inode, ix, path->p_depth - depth, 0);
1612 if (IS_ERR(bh))
1613 return PTR_ERR(bh);
1614 eh = ext_block_hdr(bh);
1615 ix = EXT_FIRST_INDEX(eh);
1616 put_bh(bh);
1617 }
1618
1619 bh = read_extent_tree_block(inode, ix, path->p_depth - depth, 0);
1620 if (IS_ERR(bh))
1621 return PTR_ERR(bh);
1622 eh = ext_block_hdr(bh);
1623 ex = EXT_FIRST_EXTENT(eh);
1624found_extent:
1625 *logical = le32_to_cpu(ex->ee_block);
1626 *phys = ext4_ext_pblock(ex);
1627 if (ret_ex)
1628 *ret_ex = *ex;
1629 if (bh)
1630 put_bh(bh);
1631 return 1;
1632}
1633
1634/*
1635 * ext4_ext_next_allocated_block:
1636 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1637 * NOTE: it considers block number from index entry as
1638 * allocated block. Thus, index entries have to be consistent
1639 * with leaves.
1640 */
1641ext4_lblk_t
1642ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1643{
1644 int depth;
1645
1646 BUG_ON(path == NULL);
1647 depth = path->p_depth;
1648
1649 if (depth == 0 && path->p_ext == NULL)
1650 return EXT_MAX_BLOCKS;
1651
1652 while (depth >= 0) {
1653 struct ext4_ext_path *p = &path[depth];
1654
1655 if (depth == path->p_depth) {
1656 /* leaf */
1657 if (p->p_ext && p->p_ext != EXT_LAST_EXTENT(p->p_hdr))
1658 return le32_to_cpu(p->p_ext[1].ee_block);
1659 } else {
1660 /* index */
1661 if (p->p_idx != EXT_LAST_INDEX(p->p_hdr))
1662 return le32_to_cpu(p->p_idx[1].ei_block);
1663 }
1664 depth--;
1665 }
1666
1667 return EXT_MAX_BLOCKS;
1668}
1669
1670/*
1671 * ext4_ext_next_leaf_block:
1672 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1673 */
1674static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1675{
1676 int depth;
1677
1678 BUG_ON(path == NULL);
1679 depth = path->p_depth;
1680
1681 /* zero-tree has no leaf blocks at all */
1682 if (depth == 0)
1683 return EXT_MAX_BLOCKS;
1684
1685 /* go to index block */
1686 depth--;
1687
1688 while (depth >= 0) {
1689 if (path[depth].p_idx !=
1690 EXT_LAST_INDEX(path[depth].p_hdr))
1691 return (ext4_lblk_t)
1692 le32_to_cpu(path[depth].p_idx[1].ei_block);
1693 depth--;
1694 }
1695
1696 return EXT_MAX_BLOCKS;
1697}
1698
1699/*
1700 * ext4_ext_correct_indexes:
1701 * if leaf gets modified and modified extent is first in the leaf,
1702 * then we have to correct all indexes above.
1703 * TODO: do we need to correct tree in all cases?
1704 */
1705static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1706 struct ext4_ext_path *path)
1707{
1708 struct ext4_extent_header *eh;
1709 int depth = ext_depth(inode);
1710 struct ext4_extent *ex;
1711 __le32 border;
1712 int k, err = 0;
1713
1714 eh = path[depth].p_hdr;
1715 ex = path[depth].p_ext;
1716
1717 if (unlikely(ex == NULL || eh == NULL)) {
1718 EXT4_ERROR_INODE(inode,
1719 "ex %p == NULL or eh %p == NULL", ex, eh);
1720 return -EFSCORRUPTED;
1721 }
1722
1723 if (depth == 0) {
1724 /* there is no tree at all */
1725 return 0;
1726 }
1727
1728 if (ex != EXT_FIRST_EXTENT(eh)) {
1729 /* we correct tree if first leaf got modified only */
1730 return 0;
1731 }
1732
1733 /*
1734 * TODO: we need correction if border is smaller than current one
1735 */
1736 k = depth - 1;
1737 border = path[depth].p_ext->ee_block;
1738 err = ext4_ext_get_access(handle, inode, path + k);
1739 if (err)
1740 return err;
1741 path[k].p_idx->ei_block = border;
1742 err = ext4_ext_dirty(handle, inode, path + k);
1743 if (err)
1744 return err;
1745
1746 while (k--) {
1747 /* change all left-side indexes */
1748 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1749 break;
1750 err = ext4_ext_get_access(handle, inode, path + k);
1751 if (err)
1752 break;
1753 path[k].p_idx->ei_block = border;
1754 err = ext4_ext_dirty(handle, inode, path + k);
1755 if (err)
1756 break;
1757 }
1758
1759 return err;
1760}
1761
1762static int ext4_can_extents_be_merged(struct inode *inode,
1763 struct ext4_extent *ex1,
1764 struct ext4_extent *ex2)
1765{
1766 unsigned short ext1_ee_len, ext2_ee_len;
1767
1768 if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
1769 return 0;
1770
1771 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1772 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1773
1774 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1775 le32_to_cpu(ex2->ee_block))
1776 return 0;
1777
1778 if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1779 return 0;
1780
1781 if (ext4_ext_is_unwritten(ex1) &&
1782 ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)
1783 return 0;
1784#ifdef AGGRESSIVE_TEST
1785 if (ext1_ee_len >= 4)
1786 return 0;
1787#endif
1788
1789 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1790 return 1;
1791 return 0;
1792}
1793
1794/*
1795 * This function tries to merge the "ex" extent to the next extent in the tree.
1796 * It always tries to merge towards right. If you want to merge towards
1797 * left, pass "ex - 1" as argument instead of "ex".
1798 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1799 * 1 if they got merged.
1800 */
1801static int ext4_ext_try_to_merge_right(struct inode *inode,
1802 struct ext4_ext_path *path,
1803 struct ext4_extent *ex)
1804{
1805 struct ext4_extent_header *eh;
1806 unsigned int depth, len;
1807 int merge_done = 0, unwritten;
1808
1809 depth = ext_depth(inode);
1810 BUG_ON(path[depth].p_hdr == NULL);
1811 eh = path[depth].p_hdr;
1812
1813 while (ex < EXT_LAST_EXTENT(eh)) {
1814 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1815 break;
1816 /* merge with next extent! */
1817 unwritten = ext4_ext_is_unwritten(ex);
1818 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1819 + ext4_ext_get_actual_len(ex + 1));
1820 if (unwritten)
1821 ext4_ext_mark_unwritten(ex);
1822
1823 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1824 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1825 * sizeof(struct ext4_extent);
1826 memmove(ex + 1, ex + 2, len);
1827 }
1828 le16_add_cpu(&eh->eh_entries, -1);
1829 merge_done = 1;
1830 WARN_ON(eh->eh_entries == 0);
1831 if (!eh->eh_entries)
1832 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1833 }
1834
1835 return merge_done;
1836}
1837
1838/*
1839 * This function does a very simple check to see if we can collapse
1840 * an extent tree with a single extent tree leaf block into the inode.
1841 */
1842static void ext4_ext_try_to_merge_up(handle_t *handle,
1843 struct inode *inode,
1844 struct ext4_ext_path *path)
1845{
1846 size_t s;
1847 unsigned max_root = ext4_ext_space_root(inode, 0);
1848 ext4_fsblk_t blk;
1849
1850 if ((path[0].p_depth != 1) ||
1851 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1852 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1853 return;
1854
1855 /*
1856 * We need to modify the block allocation bitmap and the block
1857 * group descriptor to release the extent tree block. If we
1858 * can't get the journal credits, give up.
1859 */
1860 if (ext4_journal_extend(handle, 2,
1861 ext4_free_metadata_revoke_credits(inode->i_sb, 1)))
1862 return;
1863
1864 /*
1865 * Copy the extent data up to the inode
1866 */
1867 blk = ext4_idx_pblock(path[0].p_idx);
1868 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1869 sizeof(struct ext4_extent_idx);
1870 s += sizeof(struct ext4_extent_header);
1871
1872 path[1].p_maxdepth = path[0].p_maxdepth;
1873 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1874 path[0].p_depth = 0;
1875 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1876 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1877 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1878
1879 brelse(path[1].p_bh);
1880 ext4_free_blocks(handle, inode, NULL, blk, 1,
1881 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1882}
1883
1884/*
1885 * This function tries to merge the @ex extent to neighbours in the tree, then
1886 * tries to collapse the extent tree into the inode.
1887 */
1888static void ext4_ext_try_to_merge(handle_t *handle,
1889 struct inode *inode,
1890 struct ext4_ext_path *path,
1891 struct ext4_extent *ex)
1892{
1893 struct ext4_extent_header *eh;
1894 unsigned int depth;
1895 int merge_done = 0;
1896
1897 depth = ext_depth(inode);
1898 BUG_ON(path[depth].p_hdr == NULL);
1899 eh = path[depth].p_hdr;
1900
1901 if (ex > EXT_FIRST_EXTENT(eh))
1902 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1903
1904 if (!merge_done)
1905 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1906
1907 ext4_ext_try_to_merge_up(handle, inode, path);
1908}
1909
1910/*
1911 * check if a portion of the "newext" extent overlaps with an
1912 * existing extent.
1913 *
1914 * If there is an overlap discovered, it updates the length of the newext
1915 * such that there will be no overlap, and then returns 1.
1916 * If there is no overlap found, it returns 0.
1917 */
1918static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1919 struct inode *inode,
1920 struct ext4_extent *newext,
1921 struct ext4_ext_path *path)
1922{
1923 ext4_lblk_t b1, b2;
1924 unsigned int depth, len1;
1925 unsigned int ret = 0;
1926
1927 b1 = le32_to_cpu(newext->ee_block);
1928 len1 = ext4_ext_get_actual_len(newext);
1929 depth = ext_depth(inode);
1930 if (!path[depth].p_ext)
1931 goto out;
1932 b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
1933
1934 /*
1935 * get the next allocated block if the extent in the path
1936 * is before the requested block(s)
1937 */
1938 if (b2 < b1) {
1939 b2 = ext4_ext_next_allocated_block(path);
1940 if (b2 == EXT_MAX_BLOCKS)
1941 goto out;
1942 b2 = EXT4_LBLK_CMASK(sbi, b2);
1943 }
1944
1945 /* check for wrap through zero on extent logical start block*/
1946 if (b1 + len1 < b1) {
1947 len1 = EXT_MAX_BLOCKS - b1;
1948 newext->ee_len = cpu_to_le16(len1);
1949 ret = 1;
1950 }
1951
1952 /* check for overlap */
1953 if (b1 + len1 > b2) {
1954 newext->ee_len = cpu_to_le16(b2 - b1);
1955 ret = 1;
1956 }
1957out:
1958 return ret;
1959}
1960
1961/*
1962 * ext4_ext_insert_extent:
1963 * tries to merge requested extent into the existing extent or
1964 * inserts requested extent as new one into the tree,
1965 * creating new leaf in the no-space case.
1966 */
1967int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1968 struct ext4_ext_path **ppath,
1969 struct ext4_extent *newext, int gb_flags)
1970{
1971 struct ext4_ext_path *path = *ppath;
1972 struct ext4_extent_header *eh;
1973 struct ext4_extent *ex, *fex;
1974 struct ext4_extent *nearex; /* nearest extent */
1975 struct ext4_ext_path *npath = NULL;
1976 int depth, len, err;
1977 ext4_lblk_t next;
1978 int mb_flags = 0, unwritten;
1979
1980 if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1981 mb_flags |= EXT4_MB_DELALLOC_RESERVED;
1982 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1983 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1984 return -EFSCORRUPTED;
1985 }
1986 depth = ext_depth(inode);
1987 ex = path[depth].p_ext;
1988 eh = path[depth].p_hdr;
1989 if (unlikely(path[depth].p_hdr == NULL)) {
1990 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1991 return -EFSCORRUPTED;
1992 }
1993
1994 /* try to insert block into found extent and return */
1995 if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
1996
1997 /*
1998 * Try to see whether we should rather test the extent on
1999 * right from ex, or from the left of ex. This is because
2000 * ext4_find_extent() can return either extent on the
2001 * left, or on the right from the searched position. This
2002 * will make merging more effective.
2003 */
2004 if (ex < EXT_LAST_EXTENT(eh) &&
2005 (le32_to_cpu(ex->ee_block) +
2006 ext4_ext_get_actual_len(ex) <
2007 le32_to_cpu(newext->ee_block))) {
2008 ex += 1;
2009 goto prepend;
2010 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
2011 (le32_to_cpu(newext->ee_block) +
2012 ext4_ext_get_actual_len(newext) <
2013 le32_to_cpu(ex->ee_block)))
2014 ex -= 1;
2015
2016 /* Try to append newex to the ex */
2017 if (ext4_can_extents_be_merged(inode, ex, newext)) {
2018 ext_debug(inode, "append [%d]%d block to %u:[%d]%d"
2019 "(from %llu)\n",
2020 ext4_ext_is_unwritten(newext),
2021 ext4_ext_get_actual_len(newext),
2022 le32_to_cpu(ex->ee_block),
2023 ext4_ext_is_unwritten(ex),
2024 ext4_ext_get_actual_len(ex),
2025 ext4_ext_pblock(ex));
2026 err = ext4_ext_get_access(handle, inode,
2027 path + depth);
2028 if (err)
2029 return err;
2030 unwritten = ext4_ext_is_unwritten(ex);
2031 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2032 + ext4_ext_get_actual_len(newext));
2033 if (unwritten)
2034 ext4_ext_mark_unwritten(ex);
2035 nearex = ex;
2036 goto merge;
2037 }
2038
2039prepend:
2040 /* Try to prepend newex to the ex */
2041 if (ext4_can_extents_be_merged(inode, newext, ex)) {
2042 ext_debug(inode, "prepend %u[%d]%d block to %u:[%d]%d"
2043 "(from %llu)\n",
2044 le32_to_cpu(newext->ee_block),
2045 ext4_ext_is_unwritten(newext),
2046 ext4_ext_get_actual_len(newext),
2047 le32_to_cpu(ex->ee_block),
2048 ext4_ext_is_unwritten(ex),
2049 ext4_ext_get_actual_len(ex),
2050 ext4_ext_pblock(ex));
2051 err = ext4_ext_get_access(handle, inode,
2052 path + depth);
2053 if (err)
2054 return err;
2055
2056 unwritten = ext4_ext_is_unwritten(ex);
2057 ex->ee_block = newext->ee_block;
2058 ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
2059 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2060 + ext4_ext_get_actual_len(newext));
2061 if (unwritten)
2062 ext4_ext_mark_unwritten(ex);
2063 nearex = ex;
2064 goto merge;
2065 }
2066 }
2067
2068 depth = ext_depth(inode);
2069 eh = path[depth].p_hdr;
2070 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
2071 goto has_space;
2072
2073 /* probably next leaf has space for us? */
2074 fex = EXT_LAST_EXTENT(eh);
2075 next = EXT_MAX_BLOCKS;
2076 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
2077 next = ext4_ext_next_leaf_block(path);
2078 if (next != EXT_MAX_BLOCKS) {
2079 ext_debug(inode, "next leaf block - %u\n", next);
2080 BUG_ON(npath != NULL);
2081 npath = ext4_find_extent(inode, next, NULL, gb_flags);
2082 if (IS_ERR(npath))
2083 return PTR_ERR(npath);
2084 BUG_ON(npath->p_depth != path->p_depth);
2085 eh = npath[depth].p_hdr;
2086 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2087 ext_debug(inode, "next leaf isn't full(%d)\n",
2088 le16_to_cpu(eh->eh_entries));
2089 path = npath;
2090 goto has_space;
2091 }
2092 ext_debug(inode, "next leaf has no free space(%d,%d)\n",
2093 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2094 }
2095
2096 /*
2097 * There is no free space in the found leaf.
2098 * We're gonna add a new leaf in the tree.
2099 */
2100 if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2101 mb_flags |= EXT4_MB_USE_RESERVED;
2102 err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2103 ppath, newext);
2104 if (err)
2105 goto cleanup;
2106 depth = ext_depth(inode);
2107 eh = path[depth].p_hdr;
2108
2109has_space:
2110 nearex = path[depth].p_ext;
2111
2112 err = ext4_ext_get_access(handle, inode, path + depth);
2113 if (err)
2114 goto cleanup;
2115
2116 if (!nearex) {
2117 /* there is no extent in this leaf, create first one */
2118 ext_debug(inode, "first extent in the leaf: %u:%llu:[%d]%d\n",
2119 le32_to_cpu(newext->ee_block),
2120 ext4_ext_pblock(newext),
2121 ext4_ext_is_unwritten(newext),
2122 ext4_ext_get_actual_len(newext));
2123 nearex = EXT_FIRST_EXTENT(eh);
2124 } else {
2125 if (le32_to_cpu(newext->ee_block)
2126 > le32_to_cpu(nearex->ee_block)) {
2127 /* Insert after */
2128 ext_debug(inode, "insert %u:%llu:[%d]%d before: "
2129 "nearest %p\n",
2130 le32_to_cpu(newext->ee_block),
2131 ext4_ext_pblock(newext),
2132 ext4_ext_is_unwritten(newext),
2133 ext4_ext_get_actual_len(newext),
2134 nearex);
2135 nearex++;
2136 } else {
2137 /* Insert before */
2138 BUG_ON(newext->ee_block == nearex->ee_block);
2139 ext_debug(inode, "insert %u:%llu:[%d]%d after: "
2140 "nearest %p\n",
2141 le32_to_cpu(newext->ee_block),
2142 ext4_ext_pblock(newext),
2143 ext4_ext_is_unwritten(newext),
2144 ext4_ext_get_actual_len(newext),
2145 nearex);
2146 }
2147 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2148 if (len > 0) {
2149 ext_debug(inode, "insert %u:%llu:[%d]%d: "
2150 "move %d extents from 0x%p to 0x%p\n",
2151 le32_to_cpu(newext->ee_block),
2152 ext4_ext_pblock(newext),
2153 ext4_ext_is_unwritten(newext),
2154 ext4_ext_get_actual_len(newext),
2155 len, nearex, nearex + 1);
2156 memmove(nearex + 1, nearex,
2157 len * sizeof(struct ext4_extent));
2158 }
2159 }
2160
2161 le16_add_cpu(&eh->eh_entries, 1);
2162 path[depth].p_ext = nearex;
2163 nearex->ee_block = newext->ee_block;
2164 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2165 nearex->ee_len = newext->ee_len;
2166
2167merge:
2168 /* try to merge extents */
2169 if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2170 ext4_ext_try_to_merge(handle, inode, path, nearex);
2171
2172
2173 /* time to correct all indexes above */
2174 err = ext4_ext_correct_indexes(handle, inode, path);
2175 if (err)
2176 goto cleanup;
2177
2178 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2179
2180cleanup:
2181 ext4_free_ext_path(npath);
2182 return err;
2183}
2184
2185static int ext4_fill_es_cache_info(struct inode *inode,
2186 ext4_lblk_t block, ext4_lblk_t num,
2187 struct fiemap_extent_info *fieinfo)
2188{
2189 ext4_lblk_t next, end = block + num - 1;
2190 struct extent_status es;
2191 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2192 unsigned int flags;
2193 int err;
2194
2195 while (block <= end) {
2196 next = 0;
2197 flags = 0;
2198 if (!ext4_es_lookup_extent(inode, block, &next, &es))
2199 break;
2200 if (ext4_es_is_unwritten(&es))
2201 flags |= FIEMAP_EXTENT_UNWRITTEN;
2202 if (ext4_es_is_delayed(&es))
2203 flags |= (FIEMAP_EXTENT_DELALLOC |
2204 FIEMAP_EXTENT_UNKNOWN);
2205 if (ext4_es_is_hole(&es))
2206 flags |= EXT4_FIEMAP_EXTENT_HOLE;
2207 if (next == 0)
2208 flags |= FIEMAP_EXTENT_LAST;
2209 if (flags & (FIEMAP_EXTENT_DELALLOC|
2210 EXT4_FIEMAP_EXTENT_HOLE))
2211 es.es_pblk = 0;
2212 else
2213 es.es_pblk = ext4_es_pblock(&es);
2214 err = fiemap_fill_next_extent(fieinfo,
2215 (__u64)es.es_lblk << blksize_bits,
2216 (__u64)es.es_pblk << blksize_bits,
2217 (__u64)es.es_len << blksize_bits,
2218 flags);
2219 if (next == 0)
2220 break;
2221 block = next;
2222 if (err < 0)
2223 return err;
2224 if (err == 1)
2225 return 0;
2226 }
2227 return 0;
2228}
2229
2230
2231/*
2232 * ext4_ext_determine_hole - determine hole around given block
2233 * @inode: inode we lookup in
2234 * @path: path in extent tree to @lblk
2235 * @lblk: pointer to logical block around which we want to determine hole
2236 *
2237 * Determine hole length (and start if easily possible) around given logical
2238 * block. We don't try too hard to find the beginning of the hole but @path
2239 * actually points to extent before @lblk, we provide it.
2240 *
2241 * The function returns the length of a hole starting at @lblk. We update @lblk
2242 * to the beginning of the hole if we managed to find it.
2243 */
2244static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode,
2245 struct ext4_ext_path *path,
2246 ext4_lblk_t *lblk)
2247{
2248 int depth = ext_depth(inode);
2249 struct ext4_extent *ex;
2250 ext4_lblk_t len;
2251
2252 ex = path[depth].p_ext;
2253 if (ex == NULL) {
2254 /* there is no extent yet, so gap is [0;-] */
2255 *lblk = 0;
2256 len = EXT_MAX_BLOCKS;
2257 } else if (*lblk < le32_to_cpu(ex->ee_block)) {
2258 len = le32_to_cpu(ex->ee_block) - *lblk;
2259 } else if (*lblk >= le32_to_cpu(ex->ee_block)
2260 + ext4_ext_get_actual_len(ex)) {
2261 ext4_lblk_t next;
2262
2263 *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
2264 next = ext4_ext_next_allocated_block(path);
2265 BUG_ON(next == *lblk);
2266 len = next - *lblk;
2267 } else {
2268 BUG();
2269 }
2270 return len;
2271}
2272
2273/*
2274 * ext4_ext_put_gap_in_cache:
2275 * calculate boundaries of the gap that the requested block fits into
2276 * and cache this gap
2277 */
2278static void
2279ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start,
2280 ext4_lblk_t hole_len)
2281{
2282 struct extent_status es;
2283
2284 ext4_es_find_extent_range(inode, &ext4_es_is_delayed, hole_start,
2285 hole_start + hole_len - 1, &es);
2286 if (es.es_len) {
2287 /* There's delayed extent containing lblock? */
2288 if (es.es_lblk <= hole_start)
2289 return;
2290 hole_len = min(es.es_lblk - hole_start, hole_len);
2291 }
2292 ext_debug(inode, " -> %u:%u\n", hole_start, hole_len);
2293 ext4_es_insert_extent(inode, hole_start, hole_len, ~0,
2294 EXTENT_STATUS_HOLE);
2295}
2296
2297/*
2298 * ext4_ext_rm_idx:
2299 * removes index from the index block.
2300 */
2301static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2302 struct ext4_ext_path *path, int depth)
2303{
2304 int err;
2305 ext4_fsblk_t leaf;
2306
2307 /* free index block */
2308 depth--;
2309 path = path + depth;
2310 leaf = ext4_idx_pblock(path->p_idx);
2311 if (unlikely(path->p_hdr->eh_entries == 0)) {
2312 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2313 return -EFSCORRUPTED;
2314 }
2315 err = ext4_ext_get_access(handle, inode, path);
2316 if (err)
2317 return err;
2318
2319 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2320 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2321 len *= sizeof(struct ext4_extent_idx);
2322 memmove(path->p_idx, path->p_idx + 1, len);
2323 }
2324
2325 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2326 err = ext4_ext_dirty(handle, inode, path);
2327 if (err)
2328 return err;
2329 ext_debug(inode, "index is empty, remove it, free block %llu\n", leaf);
2330 trace_ext4_ext_rm_idx(inode, leaf);
2331
2332 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2333 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2334
2335 while (--depth >= 0) {
2336 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2337 break;
2338 path--;
2339 err = ext4_ext_get_access(handle, inode, path);
2340 if (err)
2341 break;
2342 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2343 err = ext4_ext_dirty(handle, inode, path);
2344 if (err)
2345 break;
2346 }
2347 return err;
2348}
2349
2350/*
2351 * ext4_ext_calc_credits_for_single_extent:
2352 * This routine returns max. credits that needed to insert an extent
2353 * to the extent tree.
2354 * When pass the actual path, the caller should calculate credits
2355 * under i_data_sem.
2356 */
2357int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2358 struct ext4_ext_path *path)
2359{
2360 if (path) {
2361 int depth = ext_depth(inode);
2362 int ret = 0;
2363
2364 /* probably there is space in leaf? */
2365 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2366 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2367
2368 /*
2369 * There are some space in the leaf tree, no
2370 * need to account for leaf block credit
2371 *
2372 * bitmaps and block group descriptor blocks
2373 * and other metadata blocks still need to be
2374 * accounted.
2375 */
2376 /* 1 bitmap, 1 block group descriptor */
2377 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2378 return ret;
2379 }
2380 }
2381
2382 return ext4_chunk_trans_blocks(inode, nrblocks);
2383}
2384
2385/*
2386 * How many index/leaf blocks need to change/allocate to add @extents extents?
2387 *
2388 * If we add a single extent, then in the worse case, each tree level
2389 * index/leaf need to be changed in case of the tree split.
2390 *
2391 * If more extents are inserted, they could cause the whole tree split more
2392 * than once, but this is really rare.
2393 */
2394int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2395{
2396 int index;
2397 int depth;
2398
2399 /* If we are converting the inline data, only one is needed here. */
2400 if (ext4_has_inline_data(inode))
2401 return 1;
2402
2403 depth = ext_depth(inode);
2404
2405 if (extents <= 1)
2406 index = depth * 2;
2407 else
2408 index = depth * 3;
2409
2410 return index;
2411}
2412
2413static inline int get_default_free_blocks_flags(struct inode *inode)
2414{
2415 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) ||
2416 ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE))
2417 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2418 else if (ext4_should_journal_data(inode))
2419 return EXT4_FREE_BLOCKS_FORGET;
2420 return 0;
2421}
2422
2423/*
2424 * ext4_rereserve_cluster - increment the reserved cluster count when
2425 * freeing a cluster with a pending reservation
2426 *
2427 * @inode - file containing the cluster
2428 * @lblk - logical block in cluster to be reserved
2429 *
2430 * Increments the reserved cluster count and adjusts quota in a bigalloc
2431 * file system when freeing a partial cluster containing at least one
2432 * delayed and unwritten block. A partial cluster meeting that
2433 * requirement will have a pending reservation. If so, the
2434 * RERESERVE_CLUSTER flag is used when calling ext4_free_blocks() to
2435 * defer reserved and allocated space accounting to a subsequent call
2436 * to this function.
2437 */
2438static void ext4_rereserve_cluster(struct inode *inode, ext4_lblk_t lblk)
2439{
2440 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2441 struct ext4_inode_info *ei = EXT4_I(inode);
2442
2443 dquot_reclaim_block(inode, EXT4_C2B(sbi, 1));
2444
2445 spin_lock(&ei->i_block_reservation_lock);
2446 ei->i_reserved_data_blocks++;
2447 percpu_counter_add(&sbi->s_dirtyclusters_counter, 1);
2448 spin_unlock(&ei->i_block_reservation_lock);
2449
2450 percpu_counter_add(&sbi->s_freeclusters_counter, 1);
2451 ext4_remove_pending(inode, lblk);
2452}
2453
2454static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2455 struct ext4_extent *ex,
2456 struct partial_cluster *partial,
2457 ext4_lblk_t from, ext4_lblk_t to)
2458{
2459 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2460 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2461 ext4_fsblk_t last_pblk, pblk;
2462 ext4_lblk_t num;
2463 int flags;
2464
2465 /* only extent tail removal is allowed */
2466 if (from < le32_to_cpu(ex->ee_block) ||
2467 to != le32_to_cpu(ex->ee_block) + ee_len - 1) {
2468 ext4_error(sbi->s_sb,
2469 "strange request: removal(2) %u-%u from %u:%u",
2470 from, to, le32_to_cpu(ex->ee_block), ee_len);
2471 return 0;
2472 }
2473
2474#ifdef EXTENTS_STATS
2475 spin_lock(&sbi->s_ext_stats_lock);
2476 sbi->s_ext_blocks += ee_len;
2477 sbi->s_ext_extents++;
2478 if (ee_len < sbi->s_ext_min)
2479 sbi->s_ext_min = ee_len;
2480 if (ee_len > sbi->s_ext_max)
2481 sbi->s_ext_max = ee_len;
2482 if (ext_depth(inode) > sbi->s_depth_max)
2483 sbi->s_depth_max = ext_depth(inode);
2484 spin_unlock(&sbi->s_ext_stats_lock);
2485#endif
2486
2487 trace_ext4_remove_blocks(inode, ex, from, to, partial);
2488
2489 /*
2490 * if we have a partial cluster, and it's different from the
2491 * cluster of the last block in the extent, we free it
2492 */
2493 last_pblk = ext4_ext_pblock(ex) + ee_len - 1;
2494
2495 if (partial->state != initial &&
2496 partial->pclu != EXT4_B2C(sbi, last_pblk)) {
2497 if (partial->state == tofree) {
2498 flags = get_default_free_blocks_flags(inode);
2499 if (ext4_is_pending(inode, partial->lblk))
2500 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2501 ext4_free_blocks(handle, inode, NULL,
2502 EXT4_C2B(sbi, partial->pclu),
2503 sbi->s_cluster_ratio, flags);
2504 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2505 ext4_rereserve_cluster(inode, partial->lblk);
2506 }
2507 partial->state = initial;
2508 }
2509
2510 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2511 pblk = ext4_ext_pblock(ex) + ee_len - num;
2512
2513 /*
2514 * We free the partial cluster at the end of the extent (if any),
2515 * unless the cluster is used by another extent (partial_cluster
2516 * state is nofree). If a partial cluster exists here, it must be
2517 * shared with the last block in the extent.
2518 */
2519 flags = get_default_free_blocks_flags(inode);
2520
2521 /* partial, left end cluster aligned, right end unaligned */
2522 if ((EXT4_LBLK_COFF(sbi, to) != sbi->s_cluster_ratio - 1) &&
2523 (EXT4_LBLK_CMASK(sbi, to) >= from) &&
2524 (partial->state != nofree)) {
2525 if (ext4_is_pending(inode, to))
2526 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2527 ext4_free_blocks(handle, inode, NULL,
2528 EXT4_PBLK_CMASK(sbi, last_pblk),
2529 sbi->s_cluster_ratio, flags);
2530 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2531 ext4_rereserve_cluster(inode, to);
2532 partial->state = initial;
2533 flags = get_default_free_blocks_flags(inode);
2534 }
2535
2536 flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2537
2538 /*
2539 * For bigalloc file systems, we never free a partial cluster
2540 * at the beginning of the extent. Instead, we check to see if we
2541 * need to free it on a subsequent call to ext4_remove_blocks,
2542 * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
2543 */
2544 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2545 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2546
2547 /* reset the partial cluster if we've freed past it */
2548 if (partial->state != initial && partial->pclu != EXT4_B2C(sbi, pblk))
2549 partial->state = initial;
2550
2551 /*
2552 * If we've freed the entire extent but the beginning is not left
2553 * cluster aligned and is not marked as ineligible for freeing we
2554 * record the partial cluster at the beginning of the extent. It
2555 * wasn't freed by the preceding ext4_free_blocks() call, and we
2556 * need to look farther to the left to determine if it's to be freed
2557 * (not shared with another extent). Else, reset the partial
2558 * cluster - we're either done freeing or the beginning of the
2559 * extent is left cluster aligned.
2560 */
2561 if (EXT4_LBLK_COFF(sbi, from) && num == ee_len) {
2562 if (partial->state == initial) {
2563 partial->pclu = EXT4_B2C(sbi, pblk);
2564 partial->lblk = from;
2565 partial->state = tofree;
2566 }
2567 } else {
2568 partial->state = initial;
2569 }
2570
2571 return 0;
2572}
2573
2574/*
2575 * ext4_ext_rm_leaf() Removes the extents associated with the
2576 * blocks appearing between "start" and "end". Both "start"
2577 * and "end" must appear in the same extent or EIO is returned.
2578 *
2579 * @handle: The journal handle
2580 * @inode: The files inode
2581 * @path: The path to the leaf
2582 * @partial_cluster: The cluster which we'll have to free if all extents
2583 * has been released from it. However, if this value is
2584 * negative, it's a cluster just to the right of the
2585 * punched region and it must not be freed.
2586 * @start: The first block to remove
2587 * @end: The last block to remove
2588 */
2589static int
2590ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2591 struct ext4_ext_path *path,
2592 struct partial_cluster *partial,
2593 ext4_lblk_t start, ext4_lblk_t end)
2594{
2595 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2596 int err = 0, correct_index = 0;
2597 int depth = ext_depth(inode), credits, revoke_credits;
2598 struct ext4_extent_header *eh;
2599 ext4_lblk_t a, b;
2600 unsigned num;
2601 ext4_lblk_t ex_ee_block;
2602 unsigned short ex_ee_len;
2603 unsigned unwritten = 0;
2604 struct ext4_extent *ex;
2605 ext4_fsblk_t pblk;
2606
2607 /* the header must be checked already in ext4_ext_remove_space() */
2608 ext_debug(inode, "truncate since %u in leaf to %u\n", start, end);
2609 if (!path[depth].p_hdr)
2610 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2611 eh = path[depth].p_hdr;
2612 if (unlikely(path[depth].p_hdr == NULL)) {
2613 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2614 return -EFSCORRUPTED;
2615 }
2616 /* find where to start removing */
2617 ex = path[depth].p_ext;
2618 if (!ex)
2619 ex = EXT_LAST_EXTENT(eh);
2620
2621 ex_ee_block = le32_to_cpu(ex->ee_block);
2622 ex_ee_len = ext4_ext_get_actual_len(ex);
2623
2624 trace_ext4_ext_rm_leaf(inode, start, ex, partial);
2625
2626 while (ex >= EXT_FIRST_EXTENT(eh) &&
2627 ex_ee_block + ex_ee_len > start) {
2628
2629 if (ext4_ext_is_unwritten(ex))
2630 unwritten = 1;
2631 else
2632 unwritten = 0;
2633
2634 ext_debug(inode, "remove ext %u:[%d]%d\n", ex_ee_block,
2635 unwritten, ex_ee_len);
2636 path[depth].p_ext = ex;
2637
2638 a = max(ex_ee_block, start);
2639 b = min(ex_ee_block + ex_ee_len - 1, end);
2640
2641 ext_debug(inode, " border %u:%u\n", a, b);
2642
2643 /* If this extent is beyond the end of the hole, skip it */
2644 if (end < ex_ee_block) {
2645 /*
2646 * We're going to skip this extent and move to another,
2647 * so note that its first cluster is in use to avoid
2648 * freeing it when removing blocks. Eventually, the
2649 * right edge of the truncated/punched region will
2650 * be just to the left.
2651 */
2652 if (sbi->s_cluster_ratio > 1) {
2653 pblk = ext4_ext_pblock(ex);
2654 partial->pclu = EXT4_B2C(sbi, pblk);
2655 partial->state = nofree;
2656 }
2657 ex--;
2658 ex_ee_block = le32_to_cpu(ex->ee_block);
2659 ex_ee_len = ext4_ext_get_actual_len(ex);
2660 continue;
2661 } else if (b != ex_ee_block + ex_ee_len - 1) {
2662 EXT4_ERROR_INODE(inode,
2663 "can not handle truncate %u:%u "
2664 "on extent %u:%u",
2665 start, end, ex_ee_block,
2666 ex_ee_block + ex_ee_len - 1);
2667 err = -EFSCORRUPTED;
2668 goto out;
2669 } else if (a != ex_ee_block) {
2670 /* remove tail of the extent */
2671 num = a - ex_ee_block;
2672 } else {
2673 /* remove whole extent: excellent! */
2674 num = 0;
2675 }
2676 /*
2677 * 3 for leaf, sb, and inode plus 2 (bmap and group
2678 * descriptor) for each block group; assume two block
2679 * groups plus ex_ee_len/blocks_per_block_group for
2680 * the worst case
2681 */
2682 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2683 if (ex == EXT_FIRST_EXTENT(eh)) {
2684 correct_index = 1;
2685 credits += (ext_depth(inode)) + 1;
2686 }
2687 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2688 /*
2689 * We may end up freeing some index blocks and data from the
2690 * punched range. Note that partial clusters are accounted for
2691 * by ext4_free_data_revoke_credits().
2692 */
2693 revoke_credits =
2694 ext4_free_metadata_revoke_credits(inode->i_sb,
2695 ext_depth(inode)) +
2696 ext4_free_data_revoke_credits(inode, b - a + 1);
2697
2698 err = ext4_datasem_ensure_credits(handle, inode, credits,
2699 credits, revoke_credits);
2700 if (err) {
2701 if (err > 0)
2702 err = -EAGAIN;
2703 goto out;
2704 }
2705
2706 err = ext4_ext_get_access(handle, inode, path + depth);
2707 if (err)
2708 goto out;
2709
2710 err = ext4_remove_blocks(handle, inode, ex, partial, a, b);
2711 if (err)
2712 goto out;
2713
2714 if (num == 0)
2715 /* this extent is removed; mark slot entirely unused */
2716 ext4_ext_store_pblock(ex, 0);
2717
2718 ex->ee_len = cpu_to_le16(num);
2719 /*
2720 * Do not mark unwritten if all the blocks in the
2721 * extent have been removed.
2722 */
2723 if (unwritten && num)
2724 ext4_ext_mark_unwritten(ex);
2725 /*
2726 * If the extent was completely released,
2727 * we need to remove it from the leaf
2728 */
2729 if (num == 0) {
2730 if (end != EXT_MAX_BLOCKS - 1) {
2731 /*
2732 * For hole punching, we need to scoot all the
2733 * extents up when an extent is removed so that
2734 * we dont have blank extents in the middle
2735 */
2736 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2737 sizeof(struct ext4_extent));
2738
2739 /* Now get rid of the one at the end */
2740 memset(EXT_LAST_EXTENT(eh), 0,
2741 sizeof(struct ext4_extent));
2742 }
2743 le16_add_cpu(&eh->eh_entries, -1);
2744 }
2745
2746 err = ext4_ext_dirty(handle, inode, path + depth);
2747 if (err)
2748 goto out;
2749
2750 ext_debug(inode, "new extent: %u:%u:%llu\n", ex_ee_block, num,
2751 ext4_ext_pblock(ex));
2752 ex--;
2753 ex_ee_block = le32_to_cpu(ex->ee_block);
2754 ex_ee_len = ext4_ext_get_actual_len(ex);
2755 }
2756
2757 if (correct_index && eh->eh_entries)
2758 err = ext4_ext_correct_indexes(handle, inode, path);
2759
2760 /*
2761 * If there's a partial cluster and at least one extent remains in
2762 * the leaf, free the partial cluster if it isn't shared with the
2763 * current extent. If it is shared with the current extent
2764 * we reset the partial cluster because we've reached the start of the
2765 * truncated/punched region and we're done removing blocks.
2766 */
2767 if (partial->state == tofree && ex >= EXT_FIRST_EXTENT(eh)) {
2768 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
2769 if (partial->pclu != EXT4_B2C(sbi, pblk)) {
2770 int flags = get_default_free_blocks_flags(inode);
2771
2772 if (ext4_is_pending(inode, partial->lblk))
2773 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2774 ext4_free_blocks(handle, inode, NULL,
2775 EXT4_C2B(sbi, partial->pclu),
2776 sbi->s_cluster_ratio, flags);
2777 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2778 ext4_rereserve_cluster(inode, partial->lblk);
2779 }
2780 partial->state = initial;
2781 }
2782
2783 /* if this leaf is free, then we should
2784 * remove it from index block above */
2785 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2786 err = ext4_ext_rm_idx(handle, inode, path, depth);
2787
2788out:
2789 return err;
2790}
2791
2792/*
2793 * ext4_ext_more_to_rm:
2794 * returns 1 if current index has to be freed (even partial)
2795 */
2796static int
2797ext4_ext_more_to_rm(struct ext4_ext_path *path)
2798{
2799 BUG_ON(path->p_idx == NULL);
2800
2801 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2802 return 0;
2803
2804 /*
2805 * if truncate on deeper level happened, it wasn't partial,
2806 * so we have to consider current index for truncation
2807 */
2808 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2809 return 0;
2810 return 1;
2811}
2812
2813int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2814 ext4_lblk_t end)
2815{
2816 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2817 int depth = ext_depth(inode);
2818 struct ext4_ext_path *path = NULL;
2819 struct partial_cluster partial;
2820 handle_t *handle;
2821 int i = 0, err = 0;
2822
2823 partial.pclu = 0;
2824 partial.lblk = 0;
2825 partial.state = initial;
2826
2827 ext_debug(inode, "truncate since %u to %u\n", start, end);
2828
2829 /* probably first extent we're gonna free will be last in block */
2830 handle = ext4_journal_start_with_revoke(inode, EXT4_HT_TRUNCATE,
2831 depth + 1,
2832 ext4_free_metadata_revoke_credits(inode->i_sb, depth));
2833 if (IS_ERR(handle))
2834 return PTR_ERR(handle);
2835
2836again:
2837 trace_ext4_ext_remove_space(inode, start, end, depth);
2838
2839 /*
2840 * Check if we are removing extents inside the extent tree. If that
2841 * is the case, we are going to punch a hole inside the extent tree
2842 * so we have to check whether we need to split the extent covering
2843 * the last block to remove so we can easily remove the part of it
2844 * in ext4_ext_rm_leaf().
2845 */
2846 if (end < EXT_MAX_BLOCKS - 1) {
2847 struct ext4_extent *ex;
2848 ext4_lblk_t ee_block, ex_end, lblk;
2849 ext4_fsblk_t pblk;
2850
2851 /* find extent for or closest extent to this block */
2852 path = ext4_find_extent(inode, end, NULL,
2853 EXT4_EX_NOCACHE | EXT4_EX_NOFAIL);
2854 if (IS_ERR(path)) {
2855 ext4_journal_stop(handle);
2856 return PTR_ERR(path);
2857 }
2858 depth = ext_depth(inode);
2859 /* Leaf not may not exist only if inode has no blocks at all */
2860 ex = path[depth].p_ext;
2861 if (!ex) {
2862 if (depth) {
2863 EXT4_ERROR_INODE(inode,
2864 "path[%d].p_hdr == NULL",
2865 depth);
2866 err = -EFSCORRUPTED;
2867 }
2868 goto out;
2869 }
2870
2871 ee_block = le32_to_cpu(ex->ee_block);
2872 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
2873
2874 /*
2875 * See if the last block is inside the extent, if so split
2876 * the extent at 'end' block so we can easily remove the
2877 * tail of the first part of the split extent in
2878 * ext4_ext_rm_leaf().
2879 */
2880 if (end >= ee_block && end < ex_end) {
2881
2882 /*
2883 * If we're going to split the extent, note that
2884 * the cluster containing the block after 'end' is
2885 * in use to avoid freeing it when removing blocks.
2886 */
2887 if (sbi->s_cluster_ratio > 1) {
2888 pblk = ext4_ext_pblock(ex) + end - ee_block + 1;
2889 partial.pclu = EXT4_B2C(sbi, pblk);
2890 partial.state = nofree;
2891 }
2892
2893 /*
2894 * Split the extent in two so that 'end' is the last
2895 * block in the first new extent. Also we should not
2896 * fail removing space due to ENOSPC so try to use
2897 * reserved block if that happens.
2898 */
2899 err = ext4_force_split_extent_at(handle, inode, &path,
2900 end + 1, 1);
2901 if (err < 0)
2902 goto out;
2903
2904 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end &&
2905 partial.state == initial) {
2906 /*
2907 * If we're punching, there's an extent to the right.
2908 * If the partial cluster hasn't been set, set it to
2909 * that extent's first cluster and its state to nofree
2910 * so it won't be freed should it contain blocks to be
2911 * removed. If it's already set (tofree/nofree), we're
2912 * retrying and keep the original partial cluster info
2913 * so a cluster marked tofree as a result of earlier
2914 * extent removal is not lost.
2915 */
2916 lblk = ex_end + 1;
2917 err = ext4_ext_search_right(inode, path, &lblk, &pblk,
2918 NULL);
2919 if (err < 0)
2920 goto out;
2921 if (pblk) {
2922 partial.pclu = EXT4_B2C(sbi, pblk);
2923 partial.state = nofree;
2924 }
2925 }
2926 }
2927 /*
2928 * We start scanning from right side, freeing all the blocks
2929 * after i_size and walking into the tree depth-wise.
2930 */
2931 depth = ext_depth(inode);
2932 if (path) {
2933 int k = i = depth;
2934 while (--k > 0)
2935 path[k].p_block =
2936 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2937 } else {
2938 path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
2939 GFP_NOFS | __GFP_NOFAIL);
2940 if (path == NULL) {
2941 ext4_journal_stop(handle);
2942 return -ENOMEM;
2943 }
2944 path[0].p_maxdepth = path[0].p_depth = depth;
2945 path[0].p_hdr = ext_inode_hdr(inode);
2946 i = 0;
2947
2948 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2949 err = -EFSCORRUPTED;
2950 goto out;
2951 }
2952 }
2953 err = 0;
2954
2955 while (i >= 0 && err == 0) {
2956 if (i == depth) {
2957 /* this is leaf block */
2958 err = ext4_ext_rm_leaf(handle, inode, path,
2959 &partial, start, end);
2960 /* root level has p_bh == NULL, brelse() eats this */
2961 brelse(path[i].p_bh);
2962 path[i].p_bh = NULL;
2963 i--;
2964 continue;
2965 }
2966
2967 /* this is index block */
2968 if (!path[i].p_hdr) {
2969 ext_debug(inode, "initialize header\n");
2970 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2971 }
2972
2973 if (!path[i].p_idx) {
2974 /* this level hasn't been touched yet */
2975 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2976 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2977 ext_debug(inode, "init index ptr: hdr 0x%p, num %d\n",
2978 path[i].p_hdr,
2979 le16_to_cpu(path[i].p_hdr->eh_entries));
2980 } else {
2981 /* we were already here, see at next index */
2982 path[i].p_idx--;
2983 }
2984
2985 ext_debug(inode, "level %d - index, first 0x%p, cur 0x%p\n",
2986 i, EXT_FIRST_INDEX(path[i].p_hdr),
2987 path[i].p_idx);
2988 if (ext4_ext_more_to_rm(path + i)) {
2989 struct buffer_head *bh;
2990 /* go to the next level */
2991 ext_debug(inode, "move to level %d (block %llu)\n",
2992 i + 1, ext4_idx_pblock(path[i].p_idx));
2993 memset(path + i + 1, 0, sizeof(*path));
2994 bh = read_extent_tree_block(inode, path[i].p_idx,
2995 depth - i - 1,
2996 EXT4_EX_NOCACHE);
2997 if (IS_ERR(bh)) {
2998 /* should we reset i_size? */
2999 err = PTR_ERR(bh);
3000 break;
3001 }
3002 /* Yield here to deal with large extent trees.
3003 * Should be a no-op if we did IO above. */
3004 cond_resched();
3005 if (WARN_ON(i + 1 > depth)) {
3006 err = -EFSCORRUPTED;
3007 break;
3008 }
3009 path[i + 1].p_bh = bh;
3010
3011 /* save actual number of indexes since this
3012 * number is changed at the next iteration */
3013 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
3014 i++;
3015 } else {
3016 /* we finished processing this index, go up */
3017 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
3018 /* index is empty, remove it;
3019 * handle must be already prepared by the
3020 * truncatei_leaf() */
3021 err = ext4_ext_rm_idx(handle, inode, path, i);
3022 }
3023 /* root level has p_bh == NULL, brelse() eats this */
3024 brelse(path[i].p_bh);
3025 path[i].p_bh = NULL;
3026 i--;
3027 ext_debug(inode, "return to level %d\n", i);
3028 }
3029 }
3030
3031 trace_ext4_ext_remove_space_done(inode, start, end, depth, &partial,
3032 path->p_hdr->eh_entries);
3033
3034 /*
3035 * if there's a partial cluster and we have removed the first extent
3036 * in the file, then we also free the partial cluster, if any
3037 */
3038 if (partial.state == tofree && err == 0) {
3039 int flags = get_default_free_blocks_flags(inode);
3040
3041 if (ext4_is_pending(inode, partial.lblk))
3042 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
3043 ext4_free_blocks(handle, inode, NULL,
3044 EXT4_C2B(sbi, partial.pclu),
3045 sbi->s_cluster_ratio, flags);
3046 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
3047 ext4_rereserve_cluster(inode, partial.lblk);
3048 partial.state = initial;
3049 }
3050
3051 /* TODO: flexible tree reduction should be here */
3052 if (path->p_hdr->eh_entries == 0) {
3053 /*
3054 * truncate to zero freed all the tree,
3055 * so we need to correct eh_depth
3056 */
3057 err = ext4_ext_get_access(handle, inode, path);
3058 if (err == 0) {
3059 ext_inode_hdr(inode)->eh_depth = 0;
3060 ext_inode_hdr(inode)->eh_max =
3061 cpu_to_le16(ext4_ext_space_root(inode, 0));
3062 err = ext4_ext_dirty(handle, inode, path);
3063 }
3064 }
3065out:
3066 ext4_free_ext_path(path);
3067 path = NULL;
3068 if (err == -EAGAIN)
3069 goto again;
3070 ext4_journal_stop(handle);
3071
3072 return err;
3073}
3074
3075/*
3076 * called at mount time
3077 */
3078void ext4_ext_init(struct super_block *sb)
3079{
3080 /*
3081 * possible initialization would be here
3082 */
3083
3084 if (ext4_has_feature_extents(sb)) {
3085#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
3086 printk(KERN_INFO "EXT4-fs: file extents enabled"
3087#ifdef AGGRESSIVE_TEST
3088 ", aggressive tests"
3089#endif
3090#ifdef CHECK_BINSEARCH
3091 ", check binsearch"
3092#endif
3093#ifdef EXTENTS_STATS
3094 ", stats"
3095#endif
3096 "\n");
3097#endif
3098#ifdef EXTENTS_STATS
3099 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3100 EXT4_SB(sb)->s_ext_min = 1 << 30;
3101 EXT4_SB(sb)->s_ext_max = 0;
3102#endif
3103 }
3104}
3105
3106/*
3107 * called at umount time
3108 */
3109void ext4_ext_release(struct super_block *sb)
3110{
3111 if (!ext4_has_feature_extents(sb))
3112 return;
3113
3114#ifdef EXTENTS_STATS
3115 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3116 struct ext4_sb_info *sbi = EXT4_SB(sb);
3117 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3118 sbi->s_ext_blocks, sbi->s_ext_extents,
3119 sbi->s_ext_blocks / sbi->s_ext_extents);
3120 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3121 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3122 }
3123#endif
3124}
3125
3126static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3127{
3128 ext4_lblk_t ee_block;
3129 ext4_fsblk_t ee_pblock;
3130 unsigned int ee_len;
3131
3132 ee_block = le32_to_cpu(ex->ee_block);
3133 ee_len = ext4_ext_get_actual_len(ex);
3134 ee_pblock = ext4_ext_pblock(ex);
3135
3136 if (ee_len == 0)
3137 return 0;
3138
3139 return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3140 EXTENT_STATUS_WRITTEN);
3141}
3142
3143/* FIXME!! we need to try to merge to left or right after zero-out */
3144static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3145{
3146 ext4_fsblk_t ee_pblock;
3147 unsigned int ee_len;
3148
3149 ee_len = ext4_ext_get_actual_len(ex);
3150 ee_pblock = ext4_ext_pblock(ex);
3151 return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock,
3152 ee_len);
3153}
3154
3155/*
3156 * ext4_split_extent_at() splits an extent at given block.
3157 *
3158 * @handle: the journal handle
3159 * @inode: the file inode
3160 * @path: the path to the extent
3161 * @split: the logical block where the extent is splitted.
3162 * @split_flags: indicates if the extent could be zeroout if split fails, and
3163 * the states(init or unwritten) of new extents.
3164 * @flags: flags used to insert new extent to extent tree.
3165 *
3166 *
3167 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3168 * of which are determined by split_flag.
3169 *
3170 * There are two cases:
3171 * a> the extent are splitted into two extent.
3172 * b> split is not needed, and just mark the extent.
3173 *
3174 * return 0 on success.
3175 */
3176static int ext4_split_extent_at(handle_t *handle,
3177 struct inode *inode,
3178 struct ext4_ext_path **ppath,
3179 ext4_lblk_t split,
3180 int split_flag,
3181 int flags)
3182{
3183 struct ext4_ext_path *path = *ppath;
3184 ext4_fsblk_t newblock;
3185 ext4_lblk_t ee_block;
3186 struct ext4_extent *ex, newex, orig_ex, zero_ex;
3187 struct ext4_extent *ex2 = NULL;
3188 unsigned int ee_len, depth;
3189 int err = 0;
3190
3191 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3192 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3193
3194 ext_debug(inode, "logical block %llu\n", (unsigned long long)split);
3195
3196 ext4_ext_show_leaf(inode, path);
3197
3198 depth = ext_depth(inode);
3199 ex = path[depth].p_ext;
3200 ee_block = le32_to_cpu(ex->ee_block);
3201 ee_len = ext4_ext_get_actual_len(ex);
3202 newblock = split - ee_block + ext4_ext_pblock(ex);
3203
3204 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3205 BUG_ON(!ext4_ext_is_unwritten(ex) &&
3206 split_flag & (EXT4_EXT_MAY_ZEROOUT |
3207 EXT4_EXT_MARK_UNWRIT1 |
3208 EXT4_EXT_MARK_UNWRIT2));
3209
3210 err = ext4_ext_get_access(handle, inode, path + depth);
3211 if (err)
3212 goto out;
3213
3214 if (split == ee_block) {
3215 /*
3216 * case b: block @split is the block that the extent begins with
3217 * then we just change the state of the extent, and splitting
3218 * is not needed.
3219 */
3220 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3221 ext4_ext_mark_unwritten(ex);
3222 else
3223 ext4_ext_mark_initialized(ex);
3224
3225 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3226 ext4_ext_try_to_merge(handle, inode, path, ex);
3227
3228 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3229 goto out;
3230 }
3231
3232 /* case a */
3233 memcpy(&orig_ex, ex, sizeof(orig_ex));
3234 ex->ee_len = cpu_to_le16(split - ee_block);
3235 if (split_flag & EXT4_EXT_MARK_UNWRIT1)
3236 ext4_ext_mark_unwritten(ex);
3237
3238 /*
3239 * path may lead to new leaf, not to original leaf any more
3240 * after ext4_ext_insert_extent() returns,
3241 */
3242 err = ext4_ext_dirty(handle, inode, path + depth);
3243 if (err)
3244 goto fix_extent_len;
3245
3246 ex2 = &newex;
3247 ex2->ee_block = cpu_to_le32(split);
3248 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
3249 ext4_ext_store_pblock(ex2, newblock);
3250 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3251 ext4_ext_mark_unwritten(ex2);
3252
3253 err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
3254 if (err != -ENOSPC && err != -EDQUOT)
3255 goto out;
3256
3257 if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
3258 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3259 if (split_flag & EXT4_EXT_DATA_VALID1) {
3260 err = ext4_ext_zeroout(inode, ex2);
3261 zero_ex.ee_block = ex2->ee_block;
3262 zero_ex.ee_len = cpu_to_le16(
3263 ext4_ext_get_actual_len(ex2));
3264 ext4_ext_store_pblock(&zero_ex,
3265 ext4_ext_pblock(ex2));
3266 } else {
3267 err = ext4_ext_zeroout(inode, ex);
3268 zero_ex.ee_block = ex->ee_block;
3269 zero_ex.ee_len = cpu_to_le16(
3270 ext4_ext_get_actual_len(ex));
3271 ext4_ext_store_pblock(&zero_ex,
3272 ext4_ext_pblock(ex));
3273 }
3274 } else {
3275 err = ext4_ext_zeroout(inode, &orig_ex);
3276 zero_ex.ee_block = orig_ex.ee_block;
3277 zero_ex.ee_len = cpu_to_le16(
3278 ext4_ext_get_actual_len(&orig_ex));
3279 ext4_ext_store_pblock(&zero_ex,
3280 ext4_ext_pblock(&orig_ex));
3281 }
3282
3283 if (!err) {
3284 /* update the extent length and mark as initialized */
3285 ex->ee_len = cpu_to_le16(ee_len);
3286 ext4_ext_try_to_merge(handle, inode, path, ex);
3287 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3288 if (!err)
3289 /* update extent status tree */
3290 err = ext4_zeroout_es(inode, &zero_ex);
3291 /* If we failed at this point, we don't know in which
3292 * state the extent tree exactly is so don't try to fix
3293 * length of the original extent as it may do even more
3294 * damage.
3295 */
3296 goto out;
3297 }
3298 }
3299
3300fix_extent_len:
3301 ex->ee_len = orig_ex.ee_len;
3302 /*
3303 * Ignore ext4_ext_dirty return value since we are already in error path
3304 * and err is a non-zero error code.
3305 */
3306 ext4_ext_dirty(handle, inode, path + path->p_depth);
3307 return err;
3308out:
3309 ext4_ext_show_leaf(inode, path);
3310 return err;
3311}
3312
3313/*
3314 * ext4_split_extents() splits an extent and mark extent which is covered
3315 * by @map as split_flags indicates
3316 *
3317 * It may result in splitting the extent into multiple extents (up to three)
3318 * There are three possibilities:
3319 * a> There is no split required
3320 * b> Splits in two extents: Split is happening at either end of the extent
3321 * c> Splits in three extents: Somone is splitting in middle of the extent
3322 *
3323 */
3324static int ext4_split_extent(handle_t *handle,
3325 struct inode *inode,
3326 struct ext4_ext_path **ppath,
3327 struct ext4_map_blocks *map,
3328 int split_flag,
3329 int flags)
3330{
3331 struct ext4_ext_path *path = *ppath;
3332 ext4_lblk_t ee_block;
3333 struct ext4_extent *ex;
3334 unsigned int ee_len, depth;
3335 int err = 0;
3336 int unwritten;
3337 int split_flag1, flags1;
3338 int allocated = map->m_len;
3339
3340 depth = ext_depth(inode);
3341 ex = path[depth].p_ext;
3342 ee_block = le32_to_cpu(ex->ee_block);
3343 ee_len = ext4_ext_get_actual_len(ex);
3344 unwritten = ext4_ext_is_unwritten(ex);
3345
3346 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3347 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3348 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3349 if (unwritten)
3350 split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
3351 EXT4_EXT_MARK_UNWRIT2;
3352 if (split_flag & EXT4_EXT_DATA_VALID2)
3353 split_flag1 |= EXT4_EXT_DATA_VALID1;
3354 err = ext4_split_extent_at(handle, inode, ppath,
3355 map->m_lblk + map->m_len, split_flag1, flags1);
3356 if (err)
3357 goto out;
3358 } else {
3359 allocated = ee_len - (map->m_lblk - ee_block);
3360 }
3361 /*
3362 * Update path is required because previous ext4_split_extent_at() may
3363 * result in split of original leaf or extent zeroout.
3364 */
3365 path = ext4_find_extent(inode, map->m_lblk, ppath, flags);
3366 if (IS_ERR(path))
3367 return PTR_ERR(path);
3368 depth = ext_depth(inode);
3369 ex = path[depth].p_ext;
3370 if (!ex) {
3371 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3372 (unsigned long) map->m_lblk);
3373 return -EFSCORRUPTED;
3374 }
3375 unwritten = ext4_ext_is_unwritten(ex);
3376
3377 if (map->m_lblk >= ee_block) {
3378 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3379 if (unwritten) {
3380 split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
3381 split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3382 EXT4_EXT_MARK_UNWRIT2);
3383 }
3384 err = ext4_split_extent_at(handle, inode, ppath,
3385 map->m_lblk, split_flag1, flags);
3386 if (err)
3387 goto out;
3388 }
3389
3390 ext4_ext_show_leaf(inode, path);
3391out:
3392 return err ? err : allocated;
3393}
3394
3395/*
3396 * This function is called by ext4_ext_map_blocks() if someone tries to write
3397 * to an unwritten extent. It may result in splitting the unwritten
3398 * extent into multiple extents (up to three - one initialized and two
3399 * unwritten).
3400 * There are three possibilities:
3401 * a> There is no split required: Entire extent should be initialized
3402 * b> Splits in two extents: Write is happening at either end of the extent
3403 * c> Splits in three extents: Somone is writing in middle of the extent
3404 *
3405 * Pre-conditions:
3406 * - The extent pointed to by 'path' is unwritten.
3407 * - The extent pointed to by 'path' contains a superset
3408 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3409 *
3410 * Post-conditions on success:
3411 * - the returned value is the number of blocks beyond map->l_lblk
3412 * that are allocated and initialized.
3413 * It is guaranteed to be >= map->m_len.
3414 */
3415static int ext4_ext_convert_to_initialized(handle_t *handle,
3416 struct inode *inode,
3417 struct ext4_map_blocks *map,
3418 struct ext4_ext_path **ppath,
3419 int flags)
3420{
3421 struct ext4_ext_path *path = *ppath;
3422 struct ext4_sb_info *sbi;
3423 struct ext4_extent_header *eh;
3424 struct ext4_map_blocks split_map;
3425 struct ext4_extent zero_ex1, zero_ex2;
3426 struct ext4_extent *ex, *abut_ex;
3427 ext4_lblk_t ee_block, eof_block;
3428 unsigned int ee_len, depth, map_len = map->m_len;
3429 int allocated = 0, max_zeroout = 0;
3430 int err = 0;
3431 int split_flag = EXT4_EXT_DATA_VALID2;
3432
3433 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3434 (unsigned long long)map->m_lblk, map_len);
3435
3436 sbi = EXT4_SB(inode->i_sb);
3437 eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1)
3438 >> inode->i_sb->s_blocksize_bits;
3439 if (eof_block < map->m_lblk + map_len)
3440 eof_block = map->m_lblk + map_len;
3441
3442 depth = ext_depth(inode);
3443 eh = path[depth].p_hdr;
3444 ex = path[depth].p_ext;
3445 ee_block = le32_to_cpu(ex->ee_block);
3446 ee_len = ext4_ext_get_actual_len(ex);
3447 zero_ex1.ee_len = 0;
3448 zero_ex2.ee_len = 0;
3449
3450 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3451
3452 /* Pre-conditions */
3453 BUG_ON(!ext4_ext_is_unwritten(ex));
3454 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3455
3456 /*
3457 * Attempt to transfer newly initialized blocks from the currently
3458 * unwritten extent to its neighbor. This is much cheaper
3459 * than an insertion followed by a merge as those involve costly
3460 * memmove() calls. Transferring to the left is the common case in
3461 * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3462 * followed by append writes.
3463 *
3464 * Limitations of the current logic:
3465 * - L1: we do not deal with writes covering the whole extent.
3466 * This would require removing the extent if the transfer
3467 * is possible.
3468 * - L2: we only attempt to merge with an extent stored in the
3469 * same extent tree node.
3470 */
3471 if ((map->m_lblk == ee_block) &&
3472 /* See if we can merge left */
3473 (map_len < ee_len) && /*L1*/
3474 (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/
3475 ext4_lblk_t prev_lblk;
3476 ext4_fsblk_t prev_pblk, ee_pblk;
3477 unsigned int prev_len;
3478
3479 abut_ex = ex - 1;
3480 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3481 prev_len = ext4_ext_get_actual_len(abut_ex);
3482 prev_pblk = ext4_ext_pblock(abut_ex);
3483 ee_pblk = ext4_ext_pblock(ex);
3484
3485 /*
3486 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3487 * upon those conditions:
3488 * - C1: abut_ex is initialized,
3489 * - C2: abut_ex is logically abutting ex,
3490 * - C3: abut_ex is physically abutting ex,
3491 * - C4: abut_ex can receive the additional blocks without
3492 * overflowing the (initialized) length limit.
3493 */
3494 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3495 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3496 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3497 (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3498 err = ext4_ext_get_access(handle, inode, path + depth);
3499 if (err)
3500 goto out;
3501
3502 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3503 map, ex, abut_ex);
3504
3505 /* Shift the start of ex by 'map_len' blocks */
3506 ex->ee_block = cpu_to_le32(ee_block + map_len);
3507 ext4_ext_store_pblock(ex, ee_pblk + map_len);
3508 ex->ee_len = cpu_to_le16(ee_len - map_len);
3509 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3510
3511 /* Extend abut_ex by 'map_len' blocks */
3512 abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3513
3514 /* Result: number of initialized blocks past m_lblk */
3515 allocated = map_len;
3516 }
3517 } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3518 (map_len < ee_len) && /*L1*/
3519 ex < EXT_LAST_EXTENT(eh)) { /*L2*/
3520 /* See if we can merge right */
3521 ext4_lblk_t next_lblk;
3522 ext4_fsblk_t next_pblk, ee_pblk;
3523 unsigned int next_len;
3524
3525 abut_ex = ex + 1;
3526 next_lblk = le32_to_cpu(abut_ex->ee_block);
3527 next_len = ext4_ext_get_actual_len(abut_ex);
3528 next_pblk = ext4_ext_pblock(abut_ex);
3529 ee_pblk = ext4_ext_pblock(ex);
3530
3531 /*
3532 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3533 * upon those conditions:
3534 * - C1: abut_ex is initialized,
3535 * - C2: abut_ex is logically abutting ex,
3536 * - C3: abut_ex is physically abutting ex,
3537 * - C4: abut_ex can receive the additional blocks without
3538 * overflowing the (initialized) length limit.
3539 */
3540 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3541 ((map->m_lblk + map_len) == next_lblk) && /*C2*/
3542 ((ee_pblk + ee_len) == next_pblk) && /*C3*/
3543 (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3544 err = ext4_ext_get_access(handle, inode, path + depth);
3545 if (err)
3546 goto out;
3547
3548 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3549 map, ex, abut_ex);
3550
3551 /* Shift the start of abut_ex by 'map_len' blocks */
3552 abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3553 ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3554 ex->ee_len = cpu_to_le16(ee_len - map_len);
3555 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3556
3557 /* Extend abut_ex by 'map_len' blocks */
3558 abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3559
3560 /* Result: number of initialized blocks past m_lblk */
3561 allocated = map_len;
3562 }
3563 }
3564 if (allocated) {
3565 /* Mark the block containing both extents as dirty */
3566 err = ext4_ext_dirty(handle, inode, path + depth);
3567
3568 /* Update path to point to the right extent */
3569 path[depth].p_ext = abut_ex;
3570 goto out;
3571 } else
3572 allocated = ee_len - (map->m_lblk - ee_block);
3573
3574 WARN_ON(map->m_lblk < ee_block);
3575 /*
3576 * It is safe to convert extent to initialized via explicit
3577 * zeroout only if extent is fully inside i_size or new_size.
3578 */
3579 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3580
3581 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3582 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3583 (inode->i_sb->s_blocksize_bits - 10);
3584
3585 /*
3586 * five cases:
3587 * 1. split the extent into three extents.
3588 * 2. split the extent into two extents, zeroout the head of the first
3589 * extent.
3590 * 3. split the extent into two extents, zeroout the tail of the second
3591 * extent.
3592 * 4. split the extent into two extents with out zeroout.
3593 * 5. no splitting needed, just possibly zeroout the head and / or the
3594 * tail of the extent.
3595 */
3596 split_map.m_lblk = map->m_lblk;
3597 split_map.m_len = map->m_len;
3598
3599 if (max_zeroout && (allocated > split_map.m_len)) {
3600 if (allocated <= max_zeroout) {
3601 /* case 3 or 5 */
3602 zero_ex1.ee_block =
3603 cpu_to_le32(split_map.m_lblk +
3604 split_map.m_len);
3605 zero_ex1.ee_len =
3606 cpu_to_le16(allocated - split_map.m_len);
3607 ext4_ext_store_pblock(&zero_ex1,
3608 ext4_ext_pblock(ex) + split_map.m_lblk +
3609 split_map.m_len - ee_block);
3610 err = ext4_ext_zeroout(inode, &zero_ex1);
3611 if (err)
3612 goto fallback;
3613 split_map.m_len = allocated;
3614 }
3615 if (split_map.m_lblk - ee_block + split_map.m_len <
3616 max_zeroout) {
3617 /* case 2 or 5 */
3618 if (split_map.m_lblk != ee_block) {
3619 zero_ex2.ee_block = ex->ee_block;
3620 zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk -
3621 ee_block);
3622 ext4_ext_store_pblock(&zero_ex2,
3623 ext4_ext_pblock(ex));
3624 err = ext4_ext_zeroout(inode, &zero_ex2);
3625 if (err)
3626 goto fallback;
3627 }
3628
3629 split_map.m_len += split_map.m_lblk - ee_block;
3630 split_map.m_lblk = ee_block;
3631 allocated = map->m_len;
3632 }
3633 }
3634
3635fallback:
3636 err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
3637 flags);
3638 if (err > 0)
3639 err = 0;
3640out:
3641 /* If we have gotten a failure, don't zero out status tree */
3642 if (!err) {
3643 err = ext4_zeroout_es(inode, &zero_ex1);
3644 if (!err)
3645 err = ext4_zeroout_es(inode, &zero_ex2);
3646 }
3647 return err ? err : allocated;
3648}
3649
3650/*
3651 * This function is called by ext4_ext_map_blocks() from
3652 * ext4_get_blocks_dio_write() when DIO to write
3653 * to an unwritten extent.
3654 *
3655 * Writing to an unwritten extent may result in splitting the unwritten
3656 * extent into multiple initialized/unwritten extents (up to three)
3657 * There are three possibilities:
3658 * a> There is no split required: Entire extent should be unwritten
3659 * b> Splits in two extents: Write is happening at either end of the extent
3660 * c> Splits in three extents: Somone is writing in middle of the extent
3661 *
3662 * This works the same way in the case of initialized -> unwritten conversion.
3663 *
3664 * One of more index blocks maybe needed if the extent tree grow after
3665 * the unwritten extent split. To prevent ENOSPC occur at the IO
3666 * complete, we need to split the unwritten extent before DIO submit
3667 * the IO. The unwritten extent called at this time will be split
3668 * into three unwritten extent(at most). After IO complete, the part
3669 * being filled will be convert to initialized by the end_io callback function
3670 * via ext4_convert_unwritten_extents().
3671 *
3672 * Returns the size of unwritten extent to be written on success.
3673 */
3674static int ext4_split_convert_extents(handle_t *handle,
3675 struct inode *inode,
3676 struct ext4_map_blocks *map,
3677 struct ext4_ext_path **ppath,
3678 int flags)
3679{
3680 struct ext4_ext_path *path = *ppath;
3681 ext4_lblk_t eof_block;
3682 ext4_lblk_t ee_block;
3683 struct ext4_extent *ex;
3684 unsigned int ee_len;
3685 int split_flag = 0, depth;
3686
3687 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3688 (unsigned long long)map->m_lblk, map->m_len);
3689
3690 eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1)
3691 >> inode->i_sb->s_blocksize_bits;
3692 if (eof_block < map->m_lblk + map->m_len)
3693 eof_block = map->m_lblk + map->m_len;
3694 /*
3695 * It is safe to convert extent to initialized via explicit
3696 * zeroout only if extent is fully inside i_size or new_size.
3697 */
3698 depth = ext_depth(inode);
3699 ex = path[depth].p_ext;
3700 ee_block = le32_to_cpu(ex->ee_block);
3701 ee_len = ext4_ext_get_actual_len(ex);
3702
3703 /* Convert to unwritten */
3704 if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
3705 split_flag |= EXT4_EXT_DATA_VALID1;
3706 /* Convert to initialized */
3707 } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
3708 split_flag |= ee_block + ee_len <= eof_block ?
3709 EXT4_EXT_MAY_ZEROOUT : 0;
3710 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
3711 }
3712 flags |= EXT4_GET_BLOCKS_PRE_IO;
3713 return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
3714}
3715
3716static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3717 struct inode *inode,
3718 struct ext4_map_blocks *map,
3719 struct ext4_ext_path **ppath)
3720{
3721 struct ext4_ext_path *path = *ppath;
3722 struct ext4_extent *ex;
3723 ext4_lblk_t ee_block;
3724 unsigned int ee_len;
3725 int depth;
3726 int err = 0;
3727
3728 depth = ext_depth(inode);
3729 ex = path[depth].p_ext;
3730 ee_block = le32_to_cpu(ex->ee_block);
3731 ee_len = ext4_ext_get_actual_len(ex);
3732
3733 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3734 (unsigned long long)ee_block, ee_len);
3735
3736 /* If extent is larger than requested it is a clear sign that we still
3737 * have some extent state machine issues left. So extent_split is still
3738 * required.
3739 * TODO: Once all related issues will be fixed this situation should be
3740 * illegal.
3741 */
3742 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3743#ifdef CONFIG_EXT4_DEBUG
3744 ext4_warning(inode->i_sb, "Inode (%ld) finished: extent logical block %llu,"
3745 " len %u; IO logical block %llu, len %u",
3746 inode->i_ino, (unsigned long long)ee_block, ee_len,
3747 (unsigned long long)map->m_lblk, map->m_len);
3748#endif
3749 err = ext4_split_convert_extents(handle, inode, map, ppath,
3750 EXT4_GET_BLOCKS_CONVERT);
3751 if (err < 0)
3752 return err;
3753 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3754 if (IS_ERR(path))
3755 return PTR_ERR(path);
3756 depth = ext_depth(inode);
3757 ex = path[depth].p_ext;
3758 }
3759
3760 err = ext4_ext_get_access(handle, inode, path + depth);
3761 if (err)
3762 goto out;
3763 /* first mark the extent as initialized */
3764 ext4_ext_mark_initialized(ex);
3765
3766 /* note: ext4_ext_correct_indexes() isn't needed here because
3767 * borders are not changed
3768 */
3769 ext4_ext_try_to_merge(handle, inode, path, ex);
3770
3771 /* Mark modified extent as dirty */
3772 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3773out:
3774 ext4_ext_show_leaf(inode, path);
3775 return err;
3776}
3777
3778static int
3779convert_initialized_extent(handle_t *handle, struct inode *inode,
3780 struct ext4_map_blocks *map,
3781 struct ext4_ext_path **ppath,
3782 unsigned int *allocated)
3783{
3784 struct ext4_ext_path *path = *ppath;
3785 struct ext4_extent *ex;
3786 ext4_lblk_t ee_block;
3787 unsigned int ee_len;
3788 int depth;
3789 int err = 0;
3790
3791 /*
3792 * Make sure that the extent is no bigger than we support with
3793 * unwritten extent
3794 */
3795 if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
3796 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
3797
3798 depth = ext_depth(inode);
3799 ex = path[depth].p_ext;
3800 ee_block = le32_to_cpu(ex->ee_block);
3801 ee_len = ext4_ext_get_actual_len(ex);
3802
3803 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3804 (unsigned long long)ee_block, ee_len);
3805
3806 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3807 err = ext4_split_convert_extents(handle, inode, map, ppath,
3808 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
3809 if (err < 0)
3810 return err;
3811 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3812 if (IS_ERR(path))
3813 return PTR_ERR(path);
3814 depth = ext_depth(inode);
3815 ex = path[depth].p_ext;
3816 if (!ex) {
3817 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3818 (unsigned long) map->m_lblk);
3819 return -EFSCORRUPTED;
3820 }
3821 }
3822
3823 err = ext4_ext_get_access(handle, inode, path + depth);
3824 if (err)
3825 return err;
3826 /* first mark the extent as unwritten */
3827 ext4_ext_mark_unwritten(ex);
3828
3829 /* note: ext4_ext_correct_indexes() isn't needed here because
3830 * borders are not changed
3831 */
3832 ext4_ext_try_to_merge(handle, inode, path, ex);
3833
3834 /* Mark modified extent as dirty */
3835 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3836 if (err)
3837 return err;
3838 ext4_ext_show_leaf(inode, path);
3839
3840 ext4_update_inode_fsync_trans(handle, inode, 1);
3841
3842 map->m_flags |= EXT4_MAP_UNWRITTEN;
3843 if (*allocated > map->m_len)
3844 *allocated = map->m_len;
3845 map->m_len = *allocated;
3846 return 0;
3847}
3848
3849static int
3850ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
3851 struct ext4_map_blocks *map,
3852 struct ext4_ext_path **ppath, int flags,
3853 unsigned int allocated, ext4_fsblk_t newblock)
3854{
3855 struct ext4_ext_path __maybe_unused *path = *ppath;
3856 int ret = 0;
3857 int err = 0;
3858
3859 ext_debug(inode, "logical block %llu, max_blocks %u, flags 0x%x, allocated %u\n",
3860 (unsigned long long)map->m_lblk, map->m_len, flags,
3861 allocated);
3862 ext4_ext_show_leaf(inode, path);
3863
3864 /*
3865 * When writing into unwritten space, we should not fail to
3866 * allocate metadata blocks for the new extent block if needed.
3867 */
3868 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
3869
3870 trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
3871 allocated, newblock);
3872
3873 /* get_block() before submitting IO, split the extent */
3874 if (flags & EXT4_GET_BLOCKS_PRE_IO) {
3875 ret = ext4_split_convert_extents(handle, inode, map, ppath,
3876 flags | EXT4_GET_BLOCKS_CONVERT);
3877 if (ret < 0) {
3878 err = ret;
3879 goto out2;
3880 }
3881 /*
3882 * shouldn't get a 0 return when splitting an extent unless
3883 * m_len is 0 (bug) or extent has been corrupted
3884 */
3885 if (unlikely(ret == 0)) {
3886 EXT4_ERROR_INODE(inode,
3887 "unexpected ret == 0, m_len = %u",
3888 map->m_len);
3889 err = -EFSCORRUPTED;
3890 goto out2;
3891 }
3892 map->m_flags |= EXT4_MAP_UNWRITTEN;
3893 goto out;
3894 }
3895 /* IO end_io complete, convert the filled extent to written */
3896 if (flags & EXT4_GET_BLOCKS_CONVERT) {
3897 err = ext4_convert_unwritten_extents_endio(handle, inode, map,
3898 ppath);
3899 if (err < 0)
3900 goto out2;
3901 ext4_update_inode_fsync_trans(handle, inode, 1);
3902 goto map_out;
3903 }
3904 /* buffered IO cases */
3905 /*
3906 * repeat fallocate creation request
3907 * we already have an unwritten extent
3908 */
3909 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
3910 map->m_flags |= EXT4_MAP_UNWRITTEN;
3911 goto map_out;
3912 }
3913
3914 /* buffered READ or buffered write_begin() lookup */
3915 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3916 /*
3917 * We have blocks reserved already. We
3918 * return allocated blocks so that delalloc
3919 * won't do block reservation for us. But
3920 * the buffer head will be unmapped so that
3921 * a read from the block returns 0s.
3922 */
3923 map->m_flags |= EXT4_MAP_UNWRITTEN;
3924 goto out1;
3925 }
3926
3927 /*
3928 * Default case when (flags & EXT4_GET_BLOCKS_CREATE) == 1.
3929 * For buffered writes, at writepage time, etc. Convert a
3930 * discovered unwritten extent to written.
3931 */
3932 ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags);
3933 if (ret < 0) {
3934 err = ret;
3935 goto out2;
3936 }
3937 ext4_update_inode_fsync_trans(handle, inode, 1);
3938 /*
3939 * shouldn't get a 0 return when converting an unwritten extent
3940 * unless m_len is 0 (bug) or extent has been corrupted
3941 */
3942 if (unlikely(ret == 0)) {
3943 EXT4_ERROR_INODE(inode, "unexpected ret == 0, m_len = %u",
3944 map->m_len);
3945 err = -EFSCORRUPTED;
3946 goto out2;
3947 }
3948
3949out:
3950 allocated = ret;
3951 map->m_flags |= EXT4_MAP_NEW;
3952map_out:
3953 map->m_flags |= EXT4_MAP_MAPPED;
3954out1:
3955 map->m_pblk = newblock;
3956 if (allocated > map->m_len)
3957 allocated = map->m_len;
3958 map->m_len = allocated;
3959 ext4_ext_show_leaf(inode, path);
3960out2:
3961 return err ? err : allocated;
3962}
3963
3964/*
3965 * get_implied_cluster_alloc - check to see if the requested
3966 * allocation (in the map structure) overlaps with a cluster already
3967 * allocated in an extent.
3968 * @sb The filesystem superblock structure
3969 * @map The requested lblk->pblk mapping
3970 * @ex The extent structure which might contain an implied
3971 * cluster allocation
3972 *
3973 * This function is called by ext4_ext_map_blocks() after we failed to
3974 * find blocks that were already in the inode's extent tree. Hence,
3975 * we know that the beginning of the requested region cannot overlap
3976 * the extent from the inode's extent tree. There are three cases we
3977 * want to catch. The first is this case:
3978 *
3979 * |--- cluster # N--|
3980 * |--- extent ---| |---- requested region ---|
3981 * |==========|
3982 *
3983 * The second case that we need to test for is this one:
3984 *
3985 * |--------- cluster # N ----------------|
3986 * |--- requested region --| |------- extent ----|
3987 * |=======================|
3988 *
3989 * The third case is when the requested region lies between two extents
3990 * within the same cluster:
3991 * |------------- cluster # N-------------|
3992 * |----- ex -----| |---- ex_right ----|
3993 * |------ requested region ------|
3994 * |================|
3995 *
3996 * In each of the above cases, we need to set the map->m_pblk and
3997 * map->m_len so it corresponds to the return the extent labelled as
3998 * "|====|" from cluster #N, since it is already in use for data in
3999 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
4000 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
4001 * as a new "allocated" block region. Otherwise, we will return 0 and
4002 * ext4_ext_map_blocks() will then allocate one or more new clusters
4003 * by calling ext4_mb_new_blocks().
4004 */
4005static int get_implied_cluster_alloc(struct super_block *sb,
4006 struct ext4_map_blocks *map,
4007 struct ext4_extent *ex,
4008 struct ext4_ext_path *path)
4009{
4010 struct ext4_sb_info *sbi = EXT4_SB(sb);
4011 ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4012 ext4_lblk_t ex_cluster_start, ex_cluster_end;
4013 ext4_lblk_t rr_cluster_start;
4014 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4015 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4016 unsigned short ee_len = ext4_ext_get_actual_len(ex);
4017
4018 /* The extent passed in that we are trying to match */
4019 ex_cluster_start = EXT4_B2C(sbi, ee_block);
4020 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
4021
4022 /* The requested region passed into ext4_map_blocks() */
4023 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
4024
4025 if ((rr_cluster_start == ex_cluster_end) ||
4026 (rr_cluster_start == ex_cluster_start)) {
4027 if (rr_cluster_start == ex_cluster_end)
4028 ee_start += ee_len - 1;
4029 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
4030 map->m_len = min(map->m_len,
4031 (unsigned) sbi->s_cluster_ratio - c_offset);
4032 /*
4033 * Check for and handle this case:
4034 *
4035 * |--------- cluster # N-------------|
4036 * |------- extent ----|
4037 * |--- requested region ---|
4038 * |===========|
4039 */
4040
4041 if (map->m_lblk < ee_block)
4042 map->m_len = min(map->m_len, ee_block - map->m_lblk);
4043
4044 /*
4045 * Check for the case where there is already another allocated
4046 * block to the right of 'ex' but before the end of the cluster.
4047 *
4048 * |------------- cluster # N-------------|
4049 * |----- ex -----| |---- ex_right ----|
4050 * |------ requested region ------|
4051 * |================|
4052 */
4053 if (map->m_lblk > ee_block) {
4054 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4055 map->m_len = min(map->m_len, next - map->m_lblk);
4056 }
4057
4058 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4059 return 1;
4060 }
4061
4062 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4063 return 0;
4064}
4065
4066
4067/*
4068 * Block allocation/map/preallocation routine for extents based files
4069 *
4070 *
4071 * Need to be called with
4072 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4073 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4074 *
4075 * return > 0, number of blocks already mapped/allocated
4076 * if create == 0 and these are pre-allocated blocks
4077 * buffer head is unmapped
4078 * otherwise blocks are mapped
4079 *
4080 * return = 0, if plain look up failed (blocks have not been allocated)
4081 * buffer head is unmapped
4082 *
4083 * return < 0, error case.
4084 */
4085int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4086 struct ext4_map_blocks *map, int flags)
4087{
4088 struct ext4_ext_path *path = NULL;
4089 struct ext4_extent newex, *ex, ex2;
4090 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4091 ext4_fsblk_t newblock = 0, pblk;
4092 int err = 0, depth, ret;
4093 unsigned int allocated = 0, offset = 0;
4094 unsigned int allocated_clusters = 0;
4095 struct ext4_allocation_request ar;
4096 ext4_lblk_t cluster_offset;
4097
4098 ext_debug(inode, "blocks %u/%u requested\n", map->m_lblk, map->m_len);
4099 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4100
4101 /* find extent for this block */
4102 path = ext4_find_extent(inode, map->m_lblk, NULL, 0);
4103 if (IS_ERR(path)) {
4104 err = PTR_ERR(path);
4105 path = NULL;
4106 goto out;
4107 }
4108
4109 depth = ext_depth(inode);
4110
4111 /*
4112 * consistent leaf must not be empty;
4113 * this situation is possible, though, _during_ tree modification;
4114 * this is why assert can't be put in ext4_find_extent()
4115 */
4116 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4117 EXT4_ERROR_INODE(inode, "bad extent address "
4118 "lblock: %lu, depth: %d pblock %lld",
4119 (unsigned long) map->m_lblk, depth,
4120 path[depth].p_block);
4121 err = -EFSCORRUPTED;
4122 goto out;
4123 }
4124
4125 ex = path[depth].p_ext;
4126 if (ex) {
4127 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4128 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4129 unsigned short ee_len;
4130
4131
4132 /*
4133 * unwritten extents are treated as holes, except that
4134 * we split out initialized portions during a write.
4135 */
4136 ee_len = ext4_ext_get_actual_len(ex);
4137
4138 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4139
4140 /* if found extent covers block, simply return it */
4141 if (in_range(map->m_lblk, ee_block, ee_len)) {
4142 newblock = map->m_lblk - ee_block + ee_start;
4143 /* number of remaining blocks in the extent */
4144 allocated = ee_len - (map->m_lblk - ee_block);
4145 ext_debug(inode, "%u fit into %u:%d -> %llu\n",
4146 map->m_lblk, ee_block, ee_len, newblock);
4147
4148 /*
4149 * If the extent is initialized check whether the
4150 * caller wants to convert it to unwritten.
4151 */
4152 if ((!ext4_ext_is_unwritten(ex)) &&
4153 (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
4154 err = convert_initialized_extent(handle,
4155 inode, map, &path, &allocated);
4156 goto out;
4157 } else if (!ext4_ext_is_unwritten(ex)) {
4158 map->m_flags |= EXT4_MAP_MAPPED;
4159 map->m_pblk = newblock;
4160 if (allocated > map->m_len)
4161 allocated = map->m_len;
4162 map->m_len = allocated;
4163 ext4_ext_show_leaf(inode, path);
4164 goto out;
4165 }
4166
4167 ret = ext4_ext_handle_unwritten_extents(
4168 handle, inode, map, &path, flags,
4169 allocated, newblock);
4170 if (ret < 0)
4171 err = ret;
4172 else
4173 allocated = ret;
4174 goto out;
4175 }
4176 }
4177
4178 /*
4179 * requested block isn't allocated yet;
4180 * we couldn't try to create block if create flag is zero
4181 */
4182 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4183 ext4_lblk_t hole_start, hole_len;
4184
4185 hole_start = map->m_lblk;
4186 hole_len = ext4_ext_determine_hole(inode, path, &hole_start);
4187 /*
4188 * put just found gap into cache to speed up
4189 * subsequent requests
4190 */
4191 ext4_ext_put_gap_in_cache(inode, hole_start, hole_len);
4192
4193 /* Update hole_len to reflect hole size after map->m_lblk */
4194 if (hole_start != map->m_lblk)
4195 hole_len -= map->m_lblk - hole_start;
4196 map->m_pblk = 0;
4197 map->m_len = min_t(unsigned int, map->m_len, hole_len);
4198
4199 goto out;
4200 }
4201
4202 /*
4203 * Okay, we need to do block allocation.
4204 */
4205 newex.ee_block = cpu_to_le32(map->m_lblk);
4206 cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4207
4208 /*
4209 * If we are doing bigalloc, check to see if the extent returned
4210 * by ext4_find_extent() implies a cluster we can use.
4211 */
4212 if (cluster_offset && ex &&
4213 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4214 ar.len = allocated = map->m_len;
4215 newblock = map->m_pblk;
4216 goto got_allocated_blocks;
4217 }
4218
4219 /* find neighbour allocated blocks */
4220 ar.lleft = map->m_lblk;
4221 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4222 if (err)
4223 goto out;
4224 ar.lright = map->m_lblk;
4225 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4226 if (err < 0)
4227 goto out;
4228
4229 /* Check if the extent after searching to the right implies a
4230 * cluster we can use. */
4231 if ((sbi->s_cluster_ratio > 1) && err &&
4232 get_implied_cluster_alloc(inode->i_sb, map, &ex2, path)) {
4233 ar.len = allocated = map->m_len;
4234 newblock = map->m_pblk;
4235 goto got_allocated_blocks;
4236 }
4237
4238 /*
4239 * See if request is beyond maximum number of blocks we can have in
4240 * a single extent. For an initialized extent this limit is
4241 * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
4242 * EXT_UNWRITTEN_MAX_LEN.
4243 */
4244 if (map->m_len > EXT_INIT_MAX_LEN &&
4245 !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4246 map->m_len = EXT_INIT_MAX_LEN;
4247 else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
4248 (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4249 map->m_len = EXT_UNWRITTEN_MAX_LEN;
4250
4251 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4252 newex.ee_len = cpu_to_le16(map->m_len);
4253 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4254 if (err)
4255 allocated = ext4_ext_get_actual_len(&newex);
4256 else
4257 allocated = map->m_len;
4258
4259 /* allocate new block */
4260 ar.inode = inode;
4261 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4262 ar.logical = map->m_lblk;
4263 /*
4264 * We calculate the offset from the beginning of the cluster
4265 * for the logical block number, since when we allocate a
4266 * physical cluster, the physical block should start at the
4267 * same offset from the beginning of the cluster. This is
4268 * needed so that future calls to get_implied_cluster_alloc()
4269 * work correctly.
4270 */
4271 offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4272 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4273 ar.goal -= offset;
4274 ar.logical -= offset;
4275 if (S_ISREG(inode->i_mode))
4276 ar.flags = EXT4_MB_HINT_DATA;
4277 else
4278 /* disable in-core preallocation for non-regular files */
4279 ar.flags = 0;
4280 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4281 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4282 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4283 ar.flags |= EXT4_MB_DELALLOC_RESERVED;
4284 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
4285 ar.flags |= EXT4_MB_USE_RESERVED;
4286 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4287 if (!newblock)
4288 goto out;
4289 allocated_clusters = ar.len;
4290 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4291 ext_debug(inode, "allocate new block: goal %llu, found %llu/%u, requested %u\n",
4292 ar.goal, newblock, ar.len, allocated);
4293 if (ar.len > allocated)
4294 ar.len = allocated;
4295
4296got_allocated_blocks:
4297 /* try to insert new extent into found leaf and return */
4298 pblk = newblock + offset;
4299 ext4_ext_store_pblock(&newex, pblk);
4300 newex.ee_len = cpu_to_le16(ar.len);
4301 /* Mark unwritten */
4302 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
4303 ext4_ext_mark_unwritten(&newex);
4304 map->m_flags |= EXT4_MAP_UNWRITTEN;
4305 }
4306
4307 err = ext4_ext_insert_extent(handle, inode, &path, &newex, flags);
4308 if (err) {
4309 if (allocated_clusters) {
4310 int fb_flags = 0;
4311
4312 /*
4313 * free data blocks we just allocated.
4314 * not a good idea to call discard here directly,
4315 * but otherwise we'd need to call it every free().
4316 */
4317 ext4_discard_preallocations(inode, 0);
4318 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4319 fb_flags = EXT4_FREE_BLOCKS_NO_QUOT_UPDATE;
4320 ext4_free_blocks(handle, inode, NULL, newblock,
4321 EXT4_C2B(sbi, allocated_clusters),
4322 fb_flags);
4323 }
4324 goto out;
4325 }
4326
4327 /*
4328 * Reduce the reserved cluster count to reflect successful deferred
4329 * allocation of delayed allocated clusters or direct allocation of
4330 * clusters discovered to be delayed allocated. Once allocated, a
4331 * cluster is not included in the reserved count.
4332 */
4333 if (test_opt(inode->i_sb, DELALLOC) && allocated_clusters) {
4334 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4335 /*
4336 * When allocating delayed allocated clusters, simply
4337 * reduce the reserved cluster count and claim quota
4338 */
4339 ext4_da_update_reserve_space(inode, allocated_clusters,
4340 1);
4341 } else {
4342 ext4_lblk_t lblk, len;
4343 unsigned int n;
4344
4345 /*
4346 * When allocating non-delayed allocated clusters
4347 * (from fallocate, filemap, DIO, or clusters
4348 * allocated when delalloc has been disabled by
4349 * ext4_nonda_switch), reduce the reserved cluster
4350 * count by the number of allocated clusters that
4351 * have previously been delayed allocated. Quota
4352 * has been claimed by ext4_mb_new_blocks() above,
4353 * so release the quota reservations made for any
4354 * previously delayed allocated clusters.
4355 */
4356 lblk = EXT4_LBLK_CMASK(sbi, map->m_lblk);
4357 len = allocated_clusters << sbi->s_cluster_bits;
4358 n = ext4_es_delayed_clu(inode, lblk, len);
4359 if (n > 0)
4360 ext4_da_update_reserve_space(inode, (int) n, 0);
4361 }
4362 }
4363
4364 /*
4365 * Cache the extent and update transaction to commit on fdatasync only
4366 * when it is _not_ an unwritten extent.
4367 */
4368 if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
4369 ext4_update_inode_fsync_trans(handle, inode, 1);
4370 else
4371 ext4_update_inode_fsync_trans(handle, inode, 0);
4372
4373 map->m_flags |= (EXT4_MAP_NEW | EXT4_MAP_MAPPED);
4374 map->m_pblk = pblk;
4375 map->m_len = ar.len;
4376 allocated = map->m_len;
4377 ext4_ext_show_leaf(inode, path);
4378out:
4379 ext4_free_ext_path(path);
4380
4381 trace_ext4_ext_map_blocks_exit(inode, flags, map,
4382 err ? err : allocated);
4383 return err ? err : allocated;
4384}
4385
4386int ext4_ext_truncate(handle_t *handle, struct inode *inode)
4387{
4388 struct super_block *sb = inode->i_sb;
4389 ext4_lblk_t last_block;
4390 int err = 0;
4391
4392 /*
4393 * TODO: optimization is possible here.
4394 * Probably we need not scan at all,
4395 * because page truncation is enough.
4396 */
4397
4398 /* we have to know where to truncate from in crash case */
4399 EXT4_I(inode)->i_disksize = inode->i_size;
4400 err = ext4_mark_inode_dirty(handle, inode);
4401 if (err)
4402 return err;
4403
4404 last_block = (inode->i_size + sb->s_blocksize - 1)
4405 >> EXT4_BLOCK_SIZE_BITS(sb);
4406retry:
4407 err = ext4_es_remove_extent(inode, last_block,
4408 EXT_MAX_BLOCKS - last_block);
4409 if (err == -ENOMEM) {
4410 memalloc_retry_wait(GFP_ATOMIC);
4411 goto retry;
4412 }
4413 if (err)
4414 return err;
4415retry_remove_space:
4416 err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4417 if (err == -ENOMEM) {
4418 memalloc_retry_wait(GFP_ATOMIC);
4419 goto retry_remove_space;
4420 }
4421 return err;
4422}
4423
4424static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
4425 ext4_lblk_t len, loff_t new_size,
4426 int flags)
4427{
4428 struct inode *inode = file_inode(file);
4429 handle_t *handle;
4430 int ret = 0, ret2 = 0, ret3 = 0;
4431 int retries = 0;
4432 int depth = 0;
4433 struct ext4_map_blocks map;
4434 unsigned int credits;
4435 loff_t epos;
4436
4437 BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS));
4438 map.m_lblk = offset;
4439 map.m_len = len;
4440 /*
4441 * Don't normalize the request if it can fit in one extent so
4442 * that it doesn't get unnecessarily split into multiple
4443 * extents.
4444 */
4445 if (len <= EXT_UNWRITTEN_MAX_LEN)
4446 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4447
4448 /*
4449 * credits to insert 1 extent into extent tree
4450 */
4451 credits = ext4_chunk_trans_blocks(inode, len);
4452 depth = ext_depth(inode);
4453
4454retry:
4455 while (len) {
4456 /*
4457 * Recalculate credits when extent tree depth changes.
4458 */
4459 if (depth != ext_depth(inode)) {
4460 credits = ext4_chunk_trans_blocks(inode, len);
4461 depth = ext_depth(inode);
4462 }
4463
4464 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4465 credits);
4466 if (IS_ERR(handle)) {
4467 ret = PTR_ERR(handle);
4468 break;
4469 }
4470 ret = ext4_map_blocks(handle, inode, &map, flags);
4471 if (ret <= 0) {
4472 ext4_debug("inode #%lu: block %u: len %u: "
4473 "ext4_ext_map_blocks returned %d",
4474 inode->i_ino, map.m_lblk,
4475 map.m_len, ret);
4476 ext4_mark_inode_dirty(handle, inode);
4477 ext4_journal_stop(handle);
4478 break;
4479 }
4480 /*
4481 * allow a full retry cycle for any remaining allocations
4482 */
4483 retries = 0;
4484 map.m_lblk += ret;
4485 map.m_len = len = len - ret;
4486 epos = (loff_t)map.m_lblk << inode->i_blkbits;
4487 inode->i_ctime = current_time(inode);
4488 if (new_size) {
4489 if (epos > new_size)
4490 epos = new_size;
4491 if (ext4_update_inode_size(inode, epos) & 0x1)
4492 inode->i_mtime = inode->i_ctime;
4493 }
4494 ret2 = ext4_mark_inode_dirty(handle, inode);
4495 ext4_update_inode_fsync_trans(handle, inode, 1);
4496 ret3 = ext4_journal_stop(handle);
4497 ret2 = ret3 ? ret3 : ret2;
4498 if (unlikely(ret2))
4499 break;
4500 }
4501 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
4502 goto retry;
4503
4504 return ret > 0 ? ret2 : ret;
4505}
4506
4507static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len);
4508
4509static int ext4_insert_range(struct file *file, loff_t offset, loff_t len);
4510
4511static long ext4_zero_range(struct file *file, loff_t offset,
4512 loff_t len, int mode)
4513{
4514 struct inode *inode = file_inode(file);
4515 struct address_space *mapping = file->f_mapping;
4516 handle_t *handle = NULL;
4517 unsigned int max_blocks;
4518 loff_t new_size = 0;
4519 int ret = 0;
4520 int flags;
4521 int credits;
4522 int partial_begin, partial_end;
4523 loff_t start, end;
4524 ext4_lblk_t lblk;
4525 unsigned int blkbits = inode->i_blkbits;
4526
4527 trace_ext4_zero_range(inode, offset, len, mode);
4528
4529 /* Call ext4_force_commit to flush all data in case of data=journal. */
4530 if (ext4_should_journal_data(inode)) {
4531 ret = ext4_force_commit(inode->i_sb);
4532 if (ret)
4533 return ret;
4534 }
4535
4536 /*
4537 * Round up offset. This is not fallocate, we need to zero out
4538 * blocks, so convert interior block aligned part of the range to
4539 * unwritten and possibly manually zero out unaligned parts of the
4540 * range.
4541 */
4542 start = round_up(offset, 1 << blkbits);
4543 end = round_down((offset + len), 1 << blkbits);
4544
4545 if (start < offset || end > offset + len)
4546 return -EINVAL;
4547 partial_begin = offset & ((1 << blkbits) - 1);
4548 partial_end = (offset + len) & ((1 << blkbits) - 1);
4549
4550 lblk = start >> blkbits;
4551 max_blocks = (end >> blkbits);
4552 if (max_blocks < lblk)
4553 max_blocks = 0;
4554 else
4555 max_blocks -= lblk;
4556
4557 inode_lock(inode);
4558
4559 /*
4560 * Indirect files do not support unwritten extents
4561 */
4562 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4563 ret = -EOPNOTSUPP;
4564 goto out_mutex;
4565 }
4566
4567 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4568 (offset + len > inode->i_size ||
4569 offset + len > EXT4_I(inode)->i_disksize)) {
4570 new_size = offset + len;
4571 ret = inode_newsize_ok(inode, new_size);
4572 if (ret)
4573 goto out_mutex;
4574 }
4575
4576 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4577
4578 /* Wait all existing dio workers, newcomers will block on i_rwsem */
4579 inode_dio_wait(inode);
4580
4581 ret = file_modified(file);
4582 if (ret)
4583 goto out_mutex;
4584
4585 /* Preallocate the range including the unaligned edges */
4586 if (partial_begin || partial_end) {
4587 ret = ext4_alloc_file_blocks(file,
4588 round_down(offset, 1 << blkbits) >> blkbits,
4589 (round_up((offset + len), 1 << blkbits) -
4590 round_down(offset, 1 << blkbits)) >> blkbits,
4591 new_size, flags);
4592 if (ret)
4593 goto out_mutex;
4594
4595 }
4596
4597 /* Zero range excluding the unaligned edges */
4598 if (max_blocks > 0) {
4599 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
4600 EXT4_EX_NOCACHE);
4601
4602 /*
4603 * Prevent page faults from reinstantiating pages we have
4604 * released from page cache.
4605 */
4606 filemap_invalidate_lock(mapping);
4607
4608 ret = ext4_break_layouts(inode);
4609 if (ret) {
4610 filemap_invalidate_unlock(mapping);
4611 goto out_mutex;
4612 }
4613
4614 ret = ext4_update_disksize_before_punch(inode, offset, len);
4615 if (ret) {
4616 filemap_invalidate_unlock(mapping);
4617 goto out_mutex;
4618 }
4619 /* Now release the pages and zero block aligned part of pages */
4620 truncate_pagecache_range(inode, start, end - 1);
4621 inode->i_mtime = inode->i_ctime = current_time(inode);
4622
4623 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4624 flags);
4625 filemap_invalidate_unlock(mapping);
4626 if (ret)
4627 goto out_mutex;
4628 }
4629 if (!partial_begin && !partial_end)
4630 goto out_mutex;
4631
4632 /*
4633 * In worst case we have to writeout two nonadjacent unwritten
4634 * blocks and update the inode
4635 */
4636 credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
4637 if (ext4_should_journal_data(inode))
4638 credits += 2;
4639 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
4640 if (IS_ERR(handle)) {
4641 ret = PTR_ERR(handle);
4642 ext4_std_error(inode->i_sb, ret);
4643 goto out_mutex;
4644 }
4645
4646 inode->i_mtime = inode->i_ctime = current_time(inode);
4647 if (new_size)
4648 ext4_update_inode_size(inode, new_size);
4649 ret = ext4_mark_inode_dirty(handle, inode);
4650 if (unlikely(ret))
4651 goto out_handle;
4652 /* Zero out partial block at the edges of the range */
4653 ret = ext4_zero_partial_blocks(handle, inode, offset, len);
4654 if (ret >= 0)
4655 ext4_update_inode_fsync_trans(handle, inode, 1);
4656
4657 if (file->f_flags & O_SYNC)
4658 ext4_handle_sync(handle);
4659
4660out_handle:
4661 ext4_journal_stop(handle);
4662out_mutex:
4663 inode_unlock(inode);
4664 return ret;
4665}
4666
4667/*
4668 * preallocate space for a file. This implements ext4's fallocate file
4669 * operation, which gets called from sys_fallocate system call.
4670 * For block-mapped files, posix_fallocate should fall back to the method
4671 * of writing zeroes to the required new blocks (the same behavior which is
4672 * expected for file systems which do not support fallocate() system call).
4673 */
4674long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4675{
4676 struct inode *inode = file_inode(file);
4677 loff_t new_size = 0;
4678 unsigned int max_blocks;
4679 int ret = 0;
4680 int flags;
4681 ext4_lblk_t lblk;
4682 unsigned int blkbits = inode->i_blkbits;
4683
4684 /*
4685 * Encrypted inodes can't handle collapse range or insert
4686 * range since we would need to re-encrypt blocks with a
4687 * different IV or XTS tweak (which are based on the logical
4688 * block number).
4689 */
4690 if (IS_ENCRYPTED(inode) &&
4691 (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE)))
4692 return -EOPNOTSUPP;
4693
4694 /* Return error if mode is not supported */
4695 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
4696 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
4697 FALLOC_FL_INSERT_RANGE))
4698 return -EOPNOTSUPP;
4699
4700 inode_lock(inode);
4701 ret = ext4_convert_inline_data(inode);
4702 inode_unlock(inode);
4703 if (ret)
4704 goto exit;
4705
4706 if (mode & FALLOC_FL_PUNCH_HOLE) {
4707 ret = ext4_punch_hole(file, offset, len);
4708 goto exit;
4709 }
4710
4711 if (mode & FALLOC_FL_COLLAPSE_RANGE) {
4712 ret = ext4_collapse_range(file, offset, len);
4713 goto exit;
4714 }
4715
4716 if (mode & FALLOC_FL_INSERT_RANGE) {
4717 ret = ext4_insert_range(file, offset, len);
4718 goto exit;
4719 }
4720
4721 if (mode & FALLOC_FL_ZERO_RANGE) {
4722 ret = ext4_zero_range(file, offset, len, mode);
4723 goto exit;
4724 }
4725 trace_ext4_fallocate_enter(inode, offset, len, mode);
4726 lblk = offset >> blkbits;
4727
4728 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
4729 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4730
4731 inode_lock(inode);
4732
4733 /*
4734 * We only support preallocation for extent-based files only
4735 */
4736 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4737 ret = -EOPNOTSUPP;
4738 goto out;
4739 }
4740
4741 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4742 (offset + len > inode->i_size ||
4743 offset + len > EXT4_I(inode)->i_disksize)) {
4744 new_size = offset + len;
4745 ret = inode_newsize_ok(inode, new_size);
4746 if (ret)
4747 goto out;
4748 }
4749
4750 /* Wait all existing dio workers, newcomers will block on i_rwsem */
4751 inode_dio_wait(inode);
4752
4753 ret = file_modified(file);
4754 if (ret)
4755 goto out;
4756
4757 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags);
4758 if (ret)
4759 goto out;
4760
4761 if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
4762 ret = ext4_fc_commit(EXT4_SB(inode->i_sb)->s_journal,
4763 EXT4_I(inode)->i_sync_tid);
4764 }
4765out:
4766 inode_unlock(inode);
4767 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4768exit:
4769 return ret;
4770}
4771
4772/*
4773 * This function convert a range of blocks to written extents
4774 * The caller of this function will pass the start offset and the size.
4775 * all unwritten extents within this range will be converted to
4776 * written extents.
4777 *
4778 * This function is called from the direct IO end io call back
4779 * function, to convert the fallocated extents after IO is completed.
4780 * Returns 0 on success.
4781 */
4782int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
4783 loff_t offset, ssize_t len)
4784{
4785 unsigned int max_blocks;
4786 int ret = 0, ret2 = 0, ret3 = 0;
4787 struct ext4_map_blocks map;
4788 unsigned int blkbits = inode->i_blkbits;
4789 unsigned int credits = 0;
4790
4791 map.m_lblk = offset >> blkbits;
4792 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
4793
4794 if (!handle) {
4795 /*
4796 * credits to insert 1 extent into extent tree
4797 */
4798 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4799 }
4800 while (ret >= 0 && ret < max_blocks) {
4801 map.m_lblk += ret;
4802 map.m_len = (max_blocks -= ret);
4803 if (credits) {
4804 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4805 credits);
4806 if (IS_ERR(handle)) {
4807 ret = PTR_ERR(handle);
4808 break;
4809 }
4810 }
4811 ret = ext4_map_blocks(handle, inode, &map,
4812 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
4813 if (ret <= 0)
4814 ext4_warning(inode->i_sb,
4815 "inode #%lu: block %u: len %u: "
4816 "ext4_ext_map_blocks returned %d",
4817 inode->i_ino, map.m_lblk,
4818 map.m_len, ret);
4819 ret2 = ext4_mark_inode_dirty(handle, inode);
4820 if (credits) {
4821 ret3 = ext4_journal_stop(handle);
4822 if (unlikely(ret3))
4823 ret2 = ret3;
4824 }
4825
4826 if (ret <= 0 || ret2)
4827 break;
4828 }
4829 return ret > 0 ? ret2 : ret;
4830}
4831
4832int ext4_convert_unwritten_io_end_vec(handle_t *handle, ext4_io_end_t *io_end)
4833{
4834 int ret = 0, err = 0;
4835 struct ext4_io_end_vec *io_end_vec;
4836
4837 /*
4838 * This is somewhat ugly but the idea is clear: When transaction is
4839 * reserved, everything goes into it. Otherwise we rather start several
4840 * smaller transactions for conversion of each extent separately.
4841 */
4842 if (handle) {
4843 handle = ext4_journal_start_reserved(handle,
4844 EXT4_HT_EXT_CONVERT);
4845 if (IS_ERR(handle))
4846 return PTR_ERR(handle);
4847 }
4848
4849 list_for_each_entry(io_end_vec, &io_end->list_vec, list) {
4850 ret = ext4_convert_unwritten_extents(handle, io_end->inode,
4851 io_end_vec->offset,
4852 io_end_vec->size);
4853 if (ret)
4854 break;
4855 }
4856
4857 if (handle)
4858 err = ext4_journal_stop(handle);
4859
4860 return ret < 0 ? ret : err;
4861}
4862
4863static int ext4_iomap_xattr_fiemap(struct inode *inode, struct iomap *iomap)
4864{
4865 __u64 physical = 0;
4866 __u64 length = 0;
4867 int blockbits = inode->i_sb->s_blocksize_bits;
4868 int error = 0;
4869 u16 iomap_type;
4870
4871 /* in-inode? */
4872 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
4873 struct ext4_iloc iloc;
4874 int offset; /* offset of xattr in inode */
4875
4876 error = ext4_get_inode_loc(inode, &iloc);
4877 if (error)
4878 return error;
4879 physical = (__u64)iloc.bh->b_blocknr << blockbits;
4880 offset = EXT4_GOOD_OLD_INODE_SIZE +
4881 EXT4_I(inode)->i_extra_isize;
4882 physical += offset;
4883 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
4884 brelse(iloc.bh);
4885 iomap_type = IOMAP_INLINE;
4886 } else if (EXT4_I(inode)->i_file_acl) { /* external block */
4887 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
4888 length = inode->i_sb->s_blocksize;
4889 iomap_type = IOMAP_MAPPED;
4890 } else {
4891 /* no in-inode or external block for xattr, so return -ENOENT */
4892 error = -ENOENT;
4893 goto out;
4894 }
4895
4896 iomap->addr = physical;
4897 iomap->offset = 0;
4898 iomap->length = length;
4899 iomap->type = iomap_type;
4900 iomap->flags = 0;
4901out:
4902 return error;
4903}
4904
4905static int ext4_iomap_xattr_begin(struct inode *inode, loff_t offset,
4906 loff_t length, unsigned flags,
4907 struct iomap *iomap, struct iomap *srcmap)
4908{
4909 int error;
4910
4911 error = ext4_iomap_xattr_fiemap(inode, iomap);
4912 if (error == 0 && (offset >= iomap->length))
4913 error = -ENOENT;
4914 return error;
4915}
4916
4917static const struct iomap_ops ext4_iomap_xattr_ops = {
4918 .iomap_begin = ext4_iomap_xattr_begin,
4919};
4920
4921static int ext4_fiemap_check_ranges(struct inode *inode, u64 start, u64 *len)
4922{
4923 u64 maxbytes;
4924
4925 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
4926 maxbytes = inode->i_sb->s_maxbytes;
4927 else
4928 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
4929
4930 if (*len == 0)
4931 return -EINVAL;
4932 if (start > maxbytes)
4933 return -EFBIG;
4934
4935 /*
4936 * Shrink request scope to what the fs can actually handle.
4937 */
4938 if (*len > maxbytes || (maxbytes - *len) < start)
4939 *len = maxbytes - start;
4940 return 0;
4941}
4942
4943int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4944 u64 start, u64 len)
4945{
4946 int error = 0;
4947
4948 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
4949 error = ext4_ext_precache(inode);
4950 if (error)
4951 return error;
4952 fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
4953 }
4954
4955 /*
4956 * For bitmap files the maximum size limit could be smaller than
4957 * s_maxbytes, so check len here manually instead of just relying on the
4958 * generic check.
4959 */
4960 error = ext4_fiemap_check_ranges(inode, start, &len);
4961 if (error)
4962 return error;
4963
4964 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
4965 fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR;
4966 return iomap_fiemap(inode, fieinfo, start, len,
4967 &ext4_iomap_xattr_ops);
4968 }
4969
4970 return iomap_fiemap(inode, fieinfo, start, len, &ext4_iomap_report_ops);
4971}
4972
4973int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo,
4974 __u64 start, __u64 len)
4975{
4976 ext4_lblk_t start_blk, len_blks;
4977 __u64 last_blk;
4978 int error = 0;
4979
4980 if (ext4_has_inline_data(inode)) {
4981 int has_inline;
4982
4983 down_read(&EXT4_I(inode)->xattr_sem);
4984 has_inline = ext4_has_inline_data(inode);
4985 up_read(&EXT4_I(inode)->xattr_sem);
4986 if (has_inline)
4987 return 0;
4988 }
4989
4990 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
4991 error = ext4_ext_precache(inode);
4992 if (error)
4993 return error;
4994 fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
4995 }
4996
4997 error = fiemap_prep(inode, fieinfo, start, &len, 0);
4998 if (error)
4999 return error;
5000
5001 error = ext4_fiemap_check_ranges(inode, start, &len);
5002 if (error)
5003 return error;
5004
5005 start_blk = start >> inode->i_sb->s_blocksize_bits;
5006 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
5007 if (last_blk >= EXT_MAX_BLOCKS)
5008 last_blk = EXT_MAX_BLOCKS-1;
5009 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
5010
5011 /*
5012 * Walk the extent tree gathering extent information
5013 * and pushing extents back to the user.
5014 */
5015 return ext4_fill_es_cache_info(inode, start_blk, len_blks, fieinfo);
5016}
5017
5018/*
5019 * ext4_ext_shift_path_extents:
5020 * Shift the extents of a path structure lying between path[depth].p_ext
5021 * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
5022 * if it is right shift or left shift operation.
5023 */
5024static int
5025ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
5026 struct inode *inode, handle_t *handle,
5027 enum SHIFT_DIRECTION SHIFT)
5028{
5029 int depth, err = 0;
5030 struct ext4_extent *ex_start, *ex_last;
5031 bool update = false;
5032 int credits, restart_credits;
5033 depth = path->p_depth;
5034
5035 while (depth >= 0) {
5036 if (depth == path->p_depth) {
5037 ex_start = path[depth].p_ext;
5038 if (!ex_start)
5039 return -EFSCORRUPTED;
5040
5041 ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
5042 /* leaf + sb + inode */
5043 credits = 3;
5044 if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) {
5045 update = true;
5046 /* extent tree + sb + inode */
5047 credits = depth + 2;
5048 }
5049
5050 restart_credits = ext4_writepage_trans_blocks(inode);
5051 err = ext4_datasem_ensure_credits(handle, inode, credits,
5052 restart_credits, 0);
5053 if (err) {
5054 if (err > 0)
5055 err = -EAGAIN;
5056 goto out;
5057 }
5058
5059 err = ext4_ext_get_access(handle, inode, path + depth);
5060 if (err)
5061 goto out;
5062
5063 while (ex_start <= ex_last) {
5064 if (SHIFT == SHIFT_LEFT) {
5065 le32_add_cpu(&ex_start->ee_block,
5066 -shift);
5067 /* Try to merge to the left. */
5068 if ((ex_start >
5069 EXT_FIRST_EXTENT(path[depth].p_hdr))
5070 &&
5071 ext4_ext_try_to_merge_right(inode,
5072 path, ex_start - 1))
5073 ex_last--;
5074 else
5075 ex_start++;
5076 } else {
5077 le32_add_cpu(&ex_last->ee_block, shift);
5078 ext4_ext_try_to_merge_right(inode, path,
5079 ex_last);
5080 ex_last--;
5081 }
5082 }
5083 err = ext4_ext_dirty(handle, inode, path + depth);
5084 if (err)
5085 goto out;
5086
5087 if (--depth < 0 || !update)
5088 break;
5089 }
5090
5091 /* Update index too */
5092 err = ext4_ext_get_access(handle, inode, path + depth);
5093 if (err)
5094 goto out;
5095
5096 if (SHIFT == SHIFT_LEFT)
5097 le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
5098 else
5099 le32_add_cpu(&path[depth].p_idx->ei_block, shift);
5100 err = ext4_ext_dirty(handle, inode, path + depth);
5101 if (err)
5102 goto out;
5103
5104 /* we are done if current index is not a starting index */
5105 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
5106 break;
5107
5108 depth--;
5109 }
5110
5111out:
5112 return err;
5113}
5114
5115/*
5116 * ext4_ext_shift_extents:
5117 * All the extents which lies in the range from @start to the last allocated
5118 * block for the @inode are shifted either towards left or right (depending
5119 * upon @SHIFT) by @shift blocks.
5120 * On success, 0 is returned, error otherwise.
5121 */
5122static int
5123ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
5124 ext4_lblk_t start, ext4_lblk_t shift,
5125 enum SHIFT_DIRECTION SHIFT)
5126{
5127 struct ext4_ext_path *path;
5128 int ret = 0, depth;
5129 struct ext4_extent *extent;
5130 ext4_lblk_t stop, *iterator, ex_start, ex_end;
5131 ext4_lblk_t tmp = EXT_MAX_BLOCKS;
5132
5133 /* Let path point to the last extent */
5134 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
5135 EXT4_EX_NOCACHE);
5136 if (IS_ERR(path))
5137 return PTR_ERR(path);
5138
5139 depth = path->p_depth;
5140 extent = path[depth].p_ext;
5141 if (!extent)
5142 goto out;
5143
5144 stop = le32_to_cpu(extent->ee_block);
5145
5146 /*
5147 * For left shifts, make sure the hole on the left is big enough to
5148 * accommodate the shift. For right shifts, make sure the last extent
5149 * won't be shifted beyond EXT_MAX_BLOCKS.
5150 */
5151 if (SHIFT == SHIFT_LEFT) {
5152 path = ext4_find_extent(inode, start - 1, &path,
5153 EXT4_EX_NOCACHE);
5154 if (IS_ERR(path))
5155 return PTR_ERR(path);
5156 depth = path->p_depth;
5157 extent = path[depth].p_ext;
5158 if (extent) {
5159 ex_start = le32_to_cpu(extent->ee_block);
5160 ex_end = le32_to_cpu(extent->ee_block) +
5161 ext4_ext_get_actual_len(extent);
5162 } else {
5163 ex_start = 0;
5164 ex_end = 0;
5165 }
5166
5167 if ((start == ex_start && shift > ex_start) ||
5168 (shift > start - ex_end)) {
5169 ret = -EINVAL;
5170 goto out;
5171 }
5172 } else {
5173 if (shift > EXT_MAX_BLOCKS -
5174 (stop + ext4_ext_get_actual_len(extent))) {
5175 ret = -EINVAL;
5176 goto out;
5177 }
5178 }
5179
5180 /*
5181 * In case of left shift, iterator points to start and it is increased
5182 * till we reach stop. In case of right shift, iterator points to stop
5183 * and it is decreased till we reach start.
5184 */
5185again:
5186 ret = 0;
5187 if (SHIFT == SHIFT_LEFT)
5188 iterator = &start;
5189 else
5190 iterator = &stop;
5191
5192 if (tmp != EXT_MAX_BLOCKS)
5193 *iterator = tmp;
5194
5195 /*
5196 * Its safe to start updating extents. Start and stop are unsigned, so
5197 * in case of right shift if extent with 0 block is reached, iterator
5198 * becomes NULL to indicate the end of the loop.
5199 */
5200 while (iterator && start <= stop) {
5201 path = ext4_find_extent(inode, *iterator, &path,
5202 EXT4_EX_NOCACHE);
5203 if (IS_ERR(path))
5204 return PTR_ERR(path);
5205 depth = path->p_depth;
5206 extent = path[depth].p_ext;
5207 if (!extent) {
5208 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
5209 (unsigned long) *iterator);
5210 return -EFSCORRUPTED;
5211 }
5212 if (SHIFT == SHIFT_LEFT && *iterator >
5213 le32_to_cpu(extent->ee_block)) {
5214 /* Hole, move to the next extent */
5215 if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
5216 path[depth].p_ext++;
5217 } else {
5218 *iterator = ext4_ext_next_allocated_block(path);
5219 continue;
5220 }
5221 }
5222
5223 tmp = *iterator;
5224 if (SHIFT == SHIFT_LEFT) {
5225 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5226 *iterator = le32_to_cpu(extent->ee_block) +
5227 ext4_ext_get_actual_len(extent);
5228 } else {
5229 extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
5230 if (le32_to_cpu(extent->ee_block) > start)
5231 *iterator = le32_to_cpu(extent->ee_block) - 1;
5232 else if (le32_to_cpu(extent->ee_block) == start)
5233 iterator = NULL;
5234 else {
5235 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5236 while (le32_to_cpu(extent->ee_block) >= start)
5237 extent--;
5238
5239 if (extent == EXT_LAST_EXTENT(path[depth].p_hdr))
5240 break;
5241
5242 extent++;
5243 iterator = NULL;
5244 }
5245 path[depth].p_ext = extent;
5246 }
5247 ret = ext4_ext_shift_path_extents(path, shift, inode,
5248 handle, SHIFT);
5249 /* iterator can be NULL which means we should break */
5250 if (ret == -EAGAIN)
5251 goto again;
5252 if (ret)
5253 break;
5254 }
5255out:
5256 ext4_free_ext_path(path);
5257 return ret;
5258}
5259
5260/*
5261 * ext4_collapse_range:
5262 * This implements the fallocate's collapse range functionality for ext4
5263 * Returns: 0 and non-zero on error.
5264 */
5265static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
5266{
5267 struct inode *inode = file_inode(file);
5268 struct super_block *sb = inode->i_sb;
5269 struct address_space *mapping = inode->i_mapping;
5270 ext4_lblk_t punch_start, punch_stop;
5271 handle_t *handle;
5272 unsigned int credits;
5273 loff_t new_size, ioffset;
5274 int ret;
5275
5276 /*
5277 * We need to test this early because xfstests assumes that a
5278 * collapse range of (0, 1) will return EOPNOTSUPP if the file
5279 * system does not support collapse range.
5280 */
5281 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5282 return -EOPNOTSUPP;
5283
5284 /* Collapse range works only on fs cluster size aligned regions. */
5285 if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
5286 return -EINVAL;
5287
5288 trace_ext4_collapse_range(inode, offset, len);
5289
5290 punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5291 punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb);
5292
5293 /* Call ext4_force_commit to flush all data in case of data=journal. */
5294 if (ext4_should_journal_data(inode)) {
5295 ret = ext4_force_commit(inode->i_sb);
5296 if (ret)
5297 return ret;
5298 }
5299
5300 inode_lock(inode);
5301 /*
5302 * There is no need to overlap collapse range with EOF, in which case
5303 * it is effectively a truncate operation
5304 */
5305 if (offset + len >= inode->i_size) {
5306 ret = -EINVAL;
5307 goto out_mutex;
5308 }
5309
5310 /* Currently just for extent based files */
5311 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5312 ret = -EOPNOTSUPP;
5313 goto out_mutex;
5314 }
5315
5316 /* Wait for existing dio to complete */
5317 inode_dio_wait(inode);
5318
5319 ret = file_modified(file);
5320 if (ret)
5321 goto out_mutex;
5322
5323 /*
5324 * Prevent page faults from reinstantiating pages we have released from
5325 * page cache.
5326 */
5327 filemap_invalidate_lock(mapping);
5328
5329 ret = ext4_break_layouts(inode);
5330 if (ret)
5331 goto out_mmap;
5332
5333 /*
5334 * Need to round down offset to be aligned with page size boundary
5335 * for page size > block size.
5336 */
5337 ioffset = round_down(offset, PAGE_SIZE);
5338 /*
5339 * Write tail of the last page before removed range since it will get
5340 * removed from the page cache below.
5341 */
5342 ret = filemap_write_and_wait_range(mapping, ioffset, offset);
5343 if (ret)
5344 goto out_mmap;
5345 /*
5346 * Write data that will be shifted to preserve them when discarding
5347 * page cache below. We are also protected from pages becoming dirty
5348 * by i_rwsem and invalidate_lock.
5349 */
5350 ret = filemap_write_and_wait_range(mapping, offset + len,
5351 LLONG_MAX);
5352 if (ret)
5353 goto out_mmap;
5354 truncate_pagecache(inode, ioffset);
5355
5356 credits = ext4_writepage_trans_blocks(inode);
5357 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5358 if (IS_ERR(handle)) {
5359 ret = PTR_ERR(handle);
5360 goto out_mmap;
5361 }
5362 ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
5363
5364 down_write(&EXT4_I(inode)->i_data_sem);
5365 ext4_discard_preallocations(inode, 0);
5366
5367 ret = ext4_es_remove_extent(inode, punch_start,
5368 EXT_MAX_BLOCKS - punch_start);
5369 if (ret) {
5370 up_write(&EXT4_I(inode)->i_data_sem);
5371 goto out_stop;
5372 }
5373
5374 ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
5375 if (ret) {
5376 up_write(&EXT4_I(inode)->i_data_sem);
5377 goto out_stop;
5378 }
5379 ext4_discard_preallocations(inode, 0);
5380
5381 ret = ext4_ext_shift_extents(inode, handle, punch_stop,
5382 punch_stop - punch_start, SHIFT_LEFT);
5383 if (ret) {
5384 up_write(&EXT4_I(inode)->i_data_sem);
5385 goto out_stop;
5386 }
5387
5388 new_size = inode->i_size - len;
5389 i_size_write(inode, new_size);
5390 EXT4_I(inode)->i_disksize = new_size;
5391
5392 up_write(&EXT4_I(inode)->i_data_sem);
5393 if (IS_SYNC(inode))
5394 ext4_handle_sync(handle);
5395 inode->i_mtime = inode->i_ctime = current_time(inode);
5396 ret = ext4_mark_inode_dirty(handle, inode);
5397 ext4_update_inode_fsync_trans(handle, inode, 1);
5398
5399out_stop:
5400 ext4_journal_stop(handle);
5401out_mmap:
5402 filemap_invalidate_unlock(mapping);
5403out_mutex:
5404 inode_unlock(inode);
5405 return ret;
5406}
5407
5408/*
5409 * ext4_insert_range:
5410 * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
5411 * The data blocks starting from @offset to the EOF are shifted by @len
5412 * towards right to create a hole in the @inode. Inode size is increased
5413 * by len bytes.
5414 * Returns 0 on success, error otherwise.
5415 */
5416static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
5417{
5418 struct inode *inode = file_inode(file);
5419 struct super_block *sb = inode->i_sb;
5420 struct address_space *mapping = inode->i_mapping;
5421 handle_t *handle;
5422 struct ext4_ext_path *path;
5423 struct ext4_extent *extent;
5424 ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
5425 unsigned int credits, ee_len;
5426 int ret = 0, depth, split_flag = 0;
5427 loff_t ioffset;
5428
5429 /*
5430 * We need to test this early because xfstests assumes that an
5431 * insert range of (0, 1) will return EOPNOTSUPP if the file
5432 * system does not support insert range.
5433 */
5434 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5435 return -EOPNOTSUPP;
5436
5437 /* Insert range works only on fs cluster size aligned regions. */
5438 if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
5439 return -EINVAL;
5440
5441 trace_ext4_insert_range(inode, offset, len);
5442
5443 offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5444 len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
5445
5446 /* Call ext4_force_commit to flush all data in case of data=journal */
5447 if (ext4_should_journal_data(inode)) {
5448 ret = ext4_force_commit(inode->i_sb);
5449 if (ret)
5450 return ret;
5451 }
5452
5453 inode_lock(inode);
5454 /* Currently just for extent based files */
5455 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5456 ret = -EOPNOTSUPP;
5457 goto out_mutex;
5458 }
5459
5460 /* Check whether the maximum file size would be exceeded */
5461 if (len > inode->i_sb->s_maxbytes - inode->i_size) {
5462 ret = -EFBIG;
5463 goto out_mutex;
5464 }
5465
5466 /* Offset must be less than i_size */
5467 if (offset >= inode->i_size) {
5468 ret = -EINVAL;
5469 goto out_mutex;
5470 }
5471
5472 /* Wait for existing dio to complete */
5473 inode_dio_wait(inode);
5474
5475 ret = file_modified(file);
5476 if (ret)
5477 goto out_mutex;
5478
5479 /*
5480 * Prevent page faults from reinstantiating pages we have released from
5481 * page cache.
5482 */
5483 filemap_invalidate_lock(mapping);
5484
5485 ret = ext4_break_layouts(inode);
5486 if (ret)
5487 goto out_mmap;
5488
5489 /*
5490 * Need to round down to align start offset to page size boundary
5491 * for page size > block size.
5492 */
5493 ioffset = round_down(offset, PAGE_SIZE);
5494 /* Write out all dirty pages */
5495 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5496 LLONG_MAX);
5497 if (ret)
5498 goto out_mmap;
5499 truncate_pagecache(inode, ioffset);
5500
5501 credits = ext4_writepage_trans_blocks(inode);
5502 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5503 if (IS_ERR(handle)) {
5504 ret = PTR_ERR(handle);
5505 goto out_mmap;
5506 }
5507 ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
5508
5509 /* Expand file to avoid data loss if there is error while shifting */
5510 inode->i_size += len;
5511 EXT4_I(inode)->i_disksize += len;
5512 inode->i_mtime = inode->i_ctime = current_time(inode);
5513 ret = ext4_mark_inode_dirty(handle, inode);
5514 if (ret)
5515 goto out_stop;
5516
5517 down_write(&EXT4_I(inode)->i_data_sem);
5518 ext4_discard_preallocations(inode, 0);
5519
5520 path = ext4_find_extent(inode, offset_lblk, NULL, 0);
5521 if (IS_ERR(path)) {
5522 up_write(&EXT4_I(inode)->i_data_sem);
5523 goto out_stop;
5524 }
5525
5526 depth = ext_depth(inode);
5527 extent = path[depth].p_ext;
5528 if (extent) {
5529 ee_start_lblk = le32_to_cpu(extent->ee_block);
5530 ee_len = ext4_ext_get_actual_len(extent);
5531
5532 /*
5533 * If offset_lblk is not the starting block of extent, split
5534 * the extent @offset_lblk
5535 */
5536 if ((offset_lblk > ee_start_lblk) &&
5537 (offset_lblk < (ee_start_lblk + ee_len))) {
5538 if (ext4_ext_is_unwritten(extent))
5539 split_flag = EXT4_EXT_MARK_UNWRIT1 |
5540 EXT4_EXT_MARK_UNWRIT2;
5541 ret = ext4_split_extent_at(handle, inode, &path,
5542 offset_lblk, split_flag,
5543 EXT4_EX_NOCACHE |
5544 EXT4_GET_BLOCKS_PRE_IO |
5545 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5546 }
5547
5548 ext4_free_ext_path(path);
5549 if (ret < 0) {
5550 up_write(&EXT4_I(inode)->i_data_sem);
5551 goto out_stop;
5552 }
5553 } else {
5554 ext4_free_ext_path(path);
5555 }
5556
5557 ret = ext4_es_remove_extent(inode, offset_lblk,
5558 EXT_MAX_BLOCKS - offset_lblk);
5559 if (ret) {
5560 up_write(&EXT4_I(inode)->i_data_sem);
5561 goto out_stop;
5562 }
5563
5564 /*
5565 * if offset_lblk lies in a hole which is at start of file, use
5566 * ee_start_lblk to shift extents
5567 */
5568 ret = ext4_ext_shift_extents(inode, handle,
5569 max(ee_start_lblk, offset_lblk), len_lblk, SHIFT_RIGHT);
5570
5571 up_write(&EXT4_I(inode)->i_data_sem);
5572 if (IS_SYNC(inode))
5573 ext4_handle_sync(handle);
5574 if (ret >= 0)
5575 ext4_update_inode_fsync_trans(handle, inode, 1);
5576
5577out_stop:
5578 ext4_journal_stop(handle);
5579out_mmap:
5580 filemap_invalidate_unlock(mapping);
5581out_mutex:
5582 inode_unlock(inode);
5583 return ret;
5584}
5585
5586/**
5587 * ext4_swap_extents() - Swap extents between two inodes
5588 * @handle: handle for this transaction
5589 * @inode1: First inode
5590 * @inode2: Second inode
5591 * @lblk1: Start block for first inode
5592 * @lblk2: Start block for second inode
5593 * @count: Number of blocks to swap
5594 * @unwritten: Mark second inode's extents as unwritten after swap
5595 * @erp: Pointer to save error value
5596 *
5597 * This helper routine does exactly what is promise "swap extents". All other
5598 * stuff such as page-cache locking consistency, bh mapping consistency or
5599 * extent's data copying must be performed by caller.
5600 * Locking:
5601 * i_rwsem is held for both inodes
5602 * i_data_sem is locked for write for both inodes
5603 * Assumptions:
5604 * All pages from requested range are locked for both inodes
5605 */
5606int
5607ext4_swap_extents(handle_t *handle, struct inode *inode1,
5608 struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
5609 ext4_lblk_t count, int unwritten, int *erp)
5610{
5611 struct ext4_ext_path *path1 = NULL;
5612 struct ext4_ext_path *path2 = NULL;
5613 int replaced_count = 0;
5614
5615 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
5616 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
5617 BUG_ON(!inode_is_locked(inode1));
5618 BUG_ON(!inode_is_locked(inode2));
5619
5620 *erp = ext4_es_remove_extent(inode1, lblk1, count);
5621 if (unlikely(*erp))
5622 return 0;
5623 *erp = ext4_es_remove_extent(inode2, lblk2, count);
5624 if (unlikely(*erp))
5625 return 0;
5626
5627 while (count) {
5628 struct ext4_extent *ex1, *ex2, tmp_ex;
5629 ext4_lblk_t e1_blk, e2_blk;
5630 int e1_len, e2_len, len;
5631 int split = 0;
5632
5633 path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE);
5634 if (IS_ERR(path1)) {
5635 *erp = PTR_ERR(path1);
5636 path1 = NULL;
5637 finish:
5638 count = 0;
5639 goto repeat;
5640 }
5641 path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE);
5642 if (IS_ERR(path2)) {
5643 *erp = PTR_ERR(path2);
5644 path2 = NULL;
5645 goto finish;
5646 }
5647 ex1 = path1[path1->p_depth].p_ext;
5648 ex2 = path2[path2->p_depth].p_ext;
5649 /* Do we have something to swap ? */
5650 if (unlikely(!ex2 || !ex1))
5651 goto finish;
5652
5653 e1_blk = le32_to_cpu(ex1->ee_block);
5654 e2_blk = le32_to_cpu(ex2->ee_block);
5655 e1_len = ext4_ext_get_actual_len(ex1);
5656 e2_len = ext4_ext_get_actual_len(ex2);
5657
5658 /* Hole handling */
5659 if (!in_range(lblk1, e1_blk, e1_len) ||
5660 !in_range(lblk2, e2_blk, e2_len)) {
5661 ext4_lblk_t next1, next2;
5662
5663 /* if hole after extent, then go to next extent */
5664 next1 = ext4_ext_next_allocated_block(path1);
5665 next2 = ext4_ext_next_allocated_block(path2);
5666 /* If hole before extent, then shift to that extent */
5667 if (e1_blk > lblk1)
5668 next1 = e1_blk;
5669 if (e2_blk > lblk2)
5670 next2 = e2_blk;
5671 /* Do we have something to swap */
5672 if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
5673 goto finish;
5674 /* Move to the rightest boundary */
5675 len = next1 - lblk1;
5676 if (len < next2 - lblk2)
5677 len = next2 - lblk2;
5678 if (len > count)
5679 len = count;
5680 lblk1 += len;
5681 lblk2 += len;
5682 count -= len;
5683 goto repeat;
5684 }
5685
5686 /* Prepare left boundary */
5687 if (e1_blk < lblk1) {
5688 split = 1;
5689 *erp = ext4_force_split_extent_at(handle, inode1,
5690 &path1, lblk1, 0);
5691 if (unlikely(*erp))
5692 goto finish;
5693 }
5694 if (e2_blk < lblk2) {
5695 split = 1;
5696 *erp = ext4_force_split_extent_at(handle, inode2,
5697 &path2, lblk2, 0);
5698 if (unlikely(*erp))
5699 goto finish;
5700 }
5701 /* ext4_split_extent_at() may result in leaf extent split,
5702 * path must to be revalidated. */
5703 if (split)
5704 goto repeat;
5705
5706 /* Prepare right boundary */
5707 len = count;
5708 if (len > e1_blk + e1_len - lblk1)
5709 len = e1_blk + e1_len - lblk1;
5710 if (len > e2_blk + e2_len - lblk2)
5711 len = e2_blk + e2_len - lblk2;
5712
5713 if (len != e1_len) {
5714 split = 1;
5715 *erp = ext4_force_split_extent_at(handle, inode1,
5716 &path1, lblk1 + len, 0);
5717 if (unlikely(*erp))
5718 goto finish;
5719 }
5720 if (len != e2_len) {
5721 split = 1;
5722 *erp = ext4_force_split_extent_at(handle, inode2,
5723 &path2, lblk2 + len, 0);
5724 if (*erp)
5725 goto finish;
5726 }
5727 /* ext4_split_extent_at() may result in leaf extent split,
5728 * path must to be revalidated. */
5729 if (split)
5730 goto repeat;
5731
5732 BUG_ON(e2_len != e1_len);
5733 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
5734 if (unlikely(*erp))
5735 goto finish;
5736 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
5737 if (unlikely(*erp))
5738 goto finish;
5739
5740 /* Both extents are fully inside boundaries. Swap it now */
5741 tmp_ex = *ex1;
5742 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
5743 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
5744 ex1->ee_len = cpu_to_le16(e2_len);
5745 ex2->ee_len = cpu_to_le16(e1_len);
5746 if (unwritten)
5747 ext4_ext_mark_unwritten(ex2);
5748 if (ext4_ext_is_unwritten(&tmp_ex))
5749 ext4_ext_mark_unwritten(ex1);
5750
5751 ext4_ext_try_to_merge(handle, inode2, path2, ex2);
5752 ext4_ext_try_to_merge(handle, inode1, path1, ex1);
5753 *erp = ext4_ext_dirty(handle, inode2, path2 +
5754 path2->p_depth);
5755 if (unlikely(*erp))
5756 goto finish;
5757 *erp = ext4_ext_dirty(handle, inode1, path1 +
5758 path1->p_depth);
5759 /*
5760 * Looks scarry ah..? second inode already points to new blocks,
5761 * and it was successfully dirtied. But luckily error may happen
5762 * only due to journal error, so full transaction will be
5763 * aborted anyway.
5764 */
5765 if (unlikely(*erp))
5766 goto finish;
5767 lblk1 += len;
5768 lblk2 += len;
5769 replaced_count += len;
5770 count -= len;
5771
5772 repeat:
5773 ext4_free_ext_path(path1);
5774 ext4_free_ext_path(path2);
5775 path1 = path2 = NULL;
5776 }
5777 return replaced_count;
5778}
5779
5780/*
5781 * ext4_clu_mapped - determine whether any block in a logical cluster has
5782 * been mapped to a physical cluster
5783 *
5784 * @inode - file containing the logical cluster
5785 * @lclu - logical cluster of interest
5786 *
5787 * Returns 1 if any block in the logical cluster is mapped, signifying
5788 * that a physical cluster has been allocated for it. Otherwise,
5789 * returns 0. Can also return negative error codes. Derived from
5790 * ext4_ext_map_blocks().
5791 */
5792int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu)
5793{
5794 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5795 struct ext4_ext_path *path;
5796 int depth, mapped = 0, err = 0;
5797 struct ext4_extent *extent;
5798 ext4_lblk_t first_lblk, first_lclu, last_lclu;
5799
5800 /*
5801 * if data can be stored inline, the logical cluster isn't
5802 * mapped - no physical clusters have been allocated, and the
5803 * file has no extents
5804 */
5805 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA))
5806 return 0;
5807
5808 /* search for the extent closest to the first block in the cluster */
5809 path = ext4_find_extent(inode, EXT4_C2B(sbi, lclu), NULL, 0);
5810 if (IS_ERR(path)) {
5811 err = PTR_ERR(path);
5812 path = NULL;
5813 goto out;
5814 }
5815
5816 depth = ext_depth(inode);
5817
5818 /*
5819 * A consistent leaf must not be empty. This situation is possible,
5820 * though, _during_ tree modification, and it's why an assert can't
5821 * be put in ext4_find_extent().
5822 */
5823 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
5824 EXT4_ERROR_INODE(inode,
5825 "bad extent address - lblock: %lu, depth: %d, pblock: %lld",
5826 (unsigned long) EXT4_C2B(sbi, lclu),
5827 depth, path[depth].p_block);
5828 err = -EFSCORRUPTED;
5829 goto out;
5830 }
5831
5832 extent = path[depth].p_ext;
5833
5834 /* can't be mapped if the extent tree is empty */
5835 if (extent == NULL)
5836 goto out;
5837
5838 first_lblk = le32_to_cpu(extent->ee_block);
5839 first_lclu = EXT4_B2C(sbi, first_lblk);
5840
5841 /*
5842 * Three possible outcomes at this point - found extent spanning
5843 * the target cluster, to the left of the target cluster, or to the
5844 * right of the target cluster. The first two cases are handled here.
5845 * The last case indicates the target cluster is not mapped.
5846 */
5847 if (lclu >= first_lclu) {
5848 last_lclu = EXT4_B2C(sbi, first_lblk +
5849 ext4_ext_get_actual_len(extent) - 1);
5850 if (lclu <= last_lclu) {
5851 mapped = 1;
5852 } else {
5853 first_lblk = ext4_ext_next_allocated_block(path);
5854 first_lclu = EXT4_B2C(sbi, first_lblk);
5855 if (lclu == first_lclu)
5856 mapped = 1;
5857 }
5858 }
5859
5860out:
5861 ext4_free_ext_path(path);
5862
5863 return err ? err : mapped;
5864}
5865
5866/*
5867 * Updates physical block address and unwritten status of extent
5868 * starting at lblk start and of len. If such an extent doesn't exist,
5869 * this function splits the extent tree appropriately to create an
5870 * extent like this. This function is called in the fast commit
5871 * replay path. Returns 0 on success and error on failure.
5872 */
5873int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start,
5874 int len, int unwritten, ext4_fsblk_t pblk)
5875{
5876 struct ext4_ext_path *path = NULL, *ppath;
5877 struct ext4_extent *ex;
5878 int ret;
5879
5880 path = ext4_find_extent(inode, start, NULL, 0);
5881 if (IS_ERR(path))
5882 return PTR_ERR(path);
5883 ex = path[path->p_depth].p_ext;
5884 if (!ex) {
5885 ret = -EFSCORRUPTED;
5886 goto out;
5887 }
5888
5889 if (le32_to_cpu(ex->ee_block) != start ||
5890 ext4_ext_get_actual_len(ex) != len) {
5891 /* We need to split this extent to match our extent first */
5892 ppath = path;
5893 down_write(&EXT4_I(inode)->i_data_sem);
5894 ret = ext4_force_split_extent_at(NULL, inode, &ppath, start, 1);
5895 up_write(&EXT4_I(inode)->i_data_sem);
5896 if (ret)
5897 goto out;
5898 kfree(path);
5899 path = ext4_find_extent(inode, start, NULL, 0);
5900 if (IS_ERR(path))
5901 return -1;
5902 ppath = path;
5903 ex = path[path->p_depth].p_ext;
5904 WARN_ON(le32_to_cpu(ex->ee_block) != start);
5905 if (ext4_ext_get_actual_len(ex) != len) {
5906 down_write(&EXT4_I(inode)->i_data_sem);
5907 ret = ext4_force_split_extent_at(NULL, inode, &ppath,
5908 start + len, 1);
5909 up_write(&EXT4_I(inode)->i_data_sem);
5910 if (ret)
5911 goto out;
5912 kfree(path);
5913 path = ext4_find_extent(inode, start, NULL, 0);
5914 if (IS_ERR(path))
5915 return -EINVAL;
5916 ex = path[path->p_depth].p_ext;
5917 }
5918 }
5919 if (unwritten)
5920 ext4_ext_mark_unwritten(ex);
5921 else
5922 ext4_ext_mark_initialized(ex);
5923 ext4_ext_store_pblock(ex, pblk);
5924 down_write(&EXT4_I(inode)->i_data_sem);
5925 ret = ext4_ext_dirty(NULL, inode, &path[path->p_depth]);
5926 up_write(&EXT4_I(inode)->i_data_sem);
5927out:
5928 ext4_free_ext_path(path);
5929 ext4_mark_inode_dirty(NULL, inode);
5930 return ret;
5931}
5932
5933/* Try to shrink the extent tree */
5934void ext4_ext_replay_shrink_inode(struct inode *inode, ext4_lblk_t end)
5935{
5936 struct ext4_ext_path *path = NULL;
5937 struct ext4_extent *ex;
5938 ext4_lblk_t old_cur, cur = 0;
5939
5940 while (cur < end) {
5941 path = ext4_find_extent(inode, cur, NULL, 0);
5942 if (IS_ERR(path))
5943 return;
5944 ex = path[path->p_depth].p_ext;
5945 if (!ex) {
5946 ext4_free_ext_path(path);
5947 ext4_mark_inode_dirty(NULL, inode);
5948 return;
5949 }
5950 old_cur = cur;
5951 cur = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
5952 if (cur <= old_cur)
5953 cur = old_cur + 1;
5954 ext4_ext_try_to_merge(NULL, inode, path, ex);
5955 down_write(&EXT4_I(inode)->i_data_sem);
5956 ext4_ext_dirty(NULL, inode, &path[path->p_depth]);
5957 up_write(&EXT4_I(inode)->i_data_sem);
5958 ext4_mark_inode_dirty(NULL, inode);
5959 ext4_free_ext_path(path);
5960 }
5961}
5962
5963/* Check if *cur is a hole and if it is, skip it */
5964static int skip_hole(struct inode *inode, ext4_lblk_t *cur)
5965{
5966 int ret;
5967 struct ext4_map_blocks map;
5968
5969 map.m_lblk = *cur;
5970 map.m_len = ((inode->i_size) >> inode->i_sb->s_blocksize_bits) - *cur;
5971
5972 ret = ext4_map_blocks(NULL, inode, &map, 0);
5973 if (ret < 0)
5974 return ret;
5975 if (ret != 0)
5976 return 0;
5977 *cur = *cur + map.m_len;
5978 return 0;
5979}
5980
5981/* Count number of blocks used by this inode and update i_blocks */
5982int ext4_ext_replay_set_iblocks(struct inode *inode)
5983{
5984 struct ext4_ext_path *path = NULL, *path2 = NULL;
5985 struct ext4_extent *ex;
5986 ext4_lblk_t cur = 0, end;
5987 int numblks = 0, i, ret = 0;
5988 ext4_fsblk_t cmp1, cmp2;
5989 struct ext4_map_blocks map;
5990
5991 /* Determin the size of the file first */
5992 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
5993 EXT4_EX_NOCACHE);
5994 if (IS_ERR(path))
5995 return PTR_ERR(path);
5996 ex = path[path->p_depth].p_ext;
5997 if (!ex) {
5998 ext4_free_ext_path(path);
5999 goto out;
6000 }
6001 end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
6002 ext4_free_ext_path(path);
6003
6004 /* Count the number of data blocks */
6005 cur = 0;
6006 while (cur < end) {
6007 map.m_lblk = cur;
6008 map.m_len = end - cur;
6009 ret = ext4_map_blocks(NULL, inode, &map, 0);
6010 if (ret < 0)
6011 break;
6012 if (ret > 0)
6013 numblks += ret;
6014 cur = cur + map.m_len;
6015 }
6016
6017 /*
6018 * Count the number of extent tree blocks. We do it by looking up
6019 * two successive extents and determining the difference between
6020 * their paths. When path is different for 2 successive extents
6021 * we compare the blocks in the path at each level and increment
6022 * iblocks by total number of differences found.
6023 */
6024 cur = 0;
6025 ret = skip_hole(inode, &cur);
6026 if (ret < 0)
6027 goto out;
6028 path = ext4_find_extent(inode, cur, NULL, 0);
6029 if (IS_ERR(path))
6030 goto out;
6031 numblks += path->p_depth;
6032 ext4_free_ext_path(path);
6033 while (cur < end) {
6034 path = ext4_find_extent(inode, cur, NULL, 0);
6035 if (IS_ERR(path))
6036 break;
6037 ex = path[path->p_depth].p_ext;
6038 if (!ex) {
6039 ext4_free_ext_path(path);
6040 return 0;
6041 }
6042 cur = max(cur + 1, le32_to_cpu(ex->ee_block) +
6043 ext4_ext_get_actual_len(ex));
6044 ret = skip_hole(inode, &cur);
6045 if (ret < 0) {
6046 ext4_free_ext_path(path);
6047 break;
6048 }
6049 path2 = ext4_find_extent(inode, cur, NULL, 0);
6050 if (IS_ERR(path2)) {
6051 ext4_free_ext_path(path);
6052 break;
6053 }
6054 for (i = 0; i <= max(path->p_depth, path2->p_depth); i++) {
6055 cmp1 = cmp2 = 0;
6056 if (i <= path->p_depth)
6057 cmp1 = path[i].p_bh ?
6058 path[i].p_bh->b_blocknr : 0;
6059 if (i <= path2->p_depth)
6060 cmp2 = path2[i].p_bh ?
6061 path2[i].p_bh->b_blocknr : 0;
6062 if (cmp1 != cmp2 && cmp2 != 0)
6063 numblks++;
6064 }
6065 ext4_free_ext_path(path);
6066 ext4_free_ext_path(path2);
6067 }
6068
6069out:
6070 inode->i_blocks = numblks << (inode->i_sb->s_blocksize_bits - 9);
6071 ext4_mark_inode_dirty(NULL, inode);
6072 return 0;
6073}
6074
6075int ext4_ext_clear_bb(struct inode *inode)
6076{
6077 struct ext4_ext_path *path = NULL;
6078 struct ext4_extent *ex;
6079 ext4_lblk_t cur = 0, end;
6080 int j, ret = 0;
6081 struct ext4_map_blocks map;
6082
6083 if (ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA))
6084 return 0;
6085
6086 /* Determin the size of the file first */
6087 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
6088 EXT4_EX_NOCACHE);
6089 if (IS_ERR(path))
6090 return PTR_ERR(path);
6091 ex = path[path->p_depth].p_ext;
6092 if (!ex) {
6093 ext4_free_ext_path(path);
6094 return 0;
6095 }
6096 end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
6097 ext4_free_ext_path(path);
6098
6099 cur = 0;
6100 while (cur < end) {
6101 map.m_lblk = cur;
6102 map.m_len = end - cur;
6103 ret = ext4_map_blocks(NULL, inode, &map, 0);
6104 if (ret < 0)
6105 break;
6106 if (ret > 0) {
6107 path = ext4_find_extent(inode, map.m_lblk, NULL, 0);
6108 if (!IS_ERR_OR_NULL(path)) {
6109 for (j = 0; j < path->p_depth; j++) {
6110
6111 ext4_mb_mark_bb(inode->i_sb,
6112 path[j].p_block, 1, 0);
6113 ext4_fc_record_regions(inode->i_sb, inode->i_ino,
6114 0, path[j].p_block, 1, 1);
6115 }
6116 ext4_free_ext_path(path);
6117 }
6118 ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, 0);
6119 ext4_fc_record_regions(inode->i_sb, inode->i_ino,
6120 map.m_lblk, map.m_pblk, map.m_len, 1);
6121 }
6122 cur = cur + map.m_len;
6123 }
6124
6125 return 0;
6126}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
4 * Written by Alex Tomas <alex@clusterfs.com>
5 *
6 * Architecture independence:
7 * Copyright (c) 2005, Bull S.A.
8 * Written by Pierre Peiffer <pierre.peiffer@bull.net>
9 */
10
11/*
12 * Extents support for EXT4
13 *
14 * TODO:
15 * - ext4*_error() should be used in some situations
16 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
17 * - smart tree reduction
18 */
19
20#include <linux/fs.h>
21#include <linux/time.h>
22#include <linux/jbd2.h>
23#include <linux/highuid.h>
24#include <linux/pagemap.h>
25#include <linux/quotaops.h>
26#include <linux/string.h>
27#include <linux/slab.h>
28#include <linux/uaccess.h>
29#include <linux/fiemap.h>
30#include <linux/iomap.h>
31#include <linux/sched/mm.h>
32#include "ext4_jbd2.h"
33#include "ext4_extents.h"
34#include "xattr.h"
35
36#include <trace/events/ext4.h>
37
38/*
39 * used by extent splitting.
40 */
41#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
42 due to ENOSPC */
43#define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */
44#define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */
45
46#define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
47#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
48
49static __le32 ext4_extent_block_csum(struct inode *inode,
50 struct ext4_extent_header *eh)
51{
52 struct ext4_inode_info *ei = EXT4_I(inode);
53 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
54 __u32 csum;
55
56 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
57 EXT4_EXTENT_TAIL_OFFSET(eh));
58 return cpu_to_le32(csum);
59}
60
61static int ext4_extent_block_csum_verify(struct inode *inode,
62 struct ext4_extent_header *eh)
63{
64 struct ext4_extent_tail *et;
65
66 if (!ext4_has_metadata_csum(inode->i_sb))
67 return 1;
68
69 et = find_ext4_extent_tail(eh);
70 if (et->et_checksum != ext4_extent_block_csum(inode, eh))
71 return 0;
72 return 1;
73}
74
75static void ext4_extent_block_csum_set(struct inode *inode,
76 struct ext4_extent_header *eh)
77{
78 struct ext4_extent_tail *et;
79
80 if (!ext4_has_metadata_csum(inode->i_sb))
81 return;
82
83 et = find_ext4_extent_tail(eh);
84 et->et_checksum = ext4_extent_block_csum(inode, eh);
85}
86
87static int ext4_split_extent_at(handle_t *handle,
88 struct inode *inode,
89 struct ext4_ext_path **ppath,
90 ext4_lblk_t split,
91 int split_flag,
92 int flags);
93
94static int ext4_ext_trunc_restart_fn(struct inode *inode, int *dropped)
95{
96 /*
97 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
98 * moment, get_block can be called only for blocks inside i_size since
99 * page cache has been already dropped and writes are blocked by
100 * i_rwsem. So we can safely drop the i_data_sem here.
101 */
102 BUG_ON(EXT4_JOURNAL(inode) == NULL);
103 ext4_discard_preallocations(inode);
104 up_write(&EXT4_I(inode)->i_data_sem);
105 *dropped = 1;
106 return 0;
107}
108
109static void ext4_ext_drop_refs(struct ext4_ext_path *path)
110{
111 int depth, i;
112
113 if (!path)
114 return;
115 depth = path->p_depth;
116 for (i = 0; i <= depth; i++, path++) {
117 brelse(path->p_bh);
118 path->p_bh = NULL;
119 }
120}
121
122void ext4_free_ext_path(struct ext4_ext_path *path)
123{
124 ext4_ext_drop_refs(path);
125 kfree(path);
126}
127
128/*
129 * Make sure 'handle' has at least 'check_cred' credits. If not, restart
130 * transaction with 'restart_cred' credits. The function drops i_data_sem
131 * when restarting transaction and gets it after transaction is restarted.
132 *
133 * The function returns 0 on success, 1 if transaction had to be restarted,
134 * and < 0 in case of fatal error.
135 */
136int ext4_datasem_ensure_credits(handle_t *handle, struct inode *inode,
137 int check_cred, int restart_cred,
138 int revoke_cred)
139{
140 int ret;
141 int dropped = 0;
142
143 ret = ext4_journal_ensure_credits_fn(handle, check_cred, restart_cred,
144 revoke_cred, ext4_ext_trunc_restart_fn(inode, &dropped));
145 if (dropped)
146 down_write(&EXT4_I(inode)->i_data_sem);
147 return ret;
148}
149
150/*
151 * could return:
152 * - EROFS
153 * - ENOMEM
154 */
155static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
156 struct ext4_ext_path *path)
157{
158 int err = 0;
159
160 if (path->p_bh) {
161 /* path points to block */
162 BUFFER_TRACE(path->p_bh, "get_write_access");
163 err = ext4_journal_get_write_access(handle, inode->i_sb,
164 path->p_bh, EXT4_JTR_NONE);
165 /*
166 * The extent buffer's verified bit will be set again in
167 * __ext4_ext_dirty(). We could leave an inconsistent
168 * buffer if the extents updating procudure break off du
169 * to some error happens, force to check it again.
170 */
171 if (!err)
172 clear_buffer_verified(path->p_bh);
173 }
174 /* path points to leaf/index in inode body */
175 /* we use in-core data, no need to protect them */
176 return err;
177}
178
179/*
180 * could return:
181 * - EROFS
182 * - ENOMEM
183 * - EIO
184 */
185static int __ext4_ext_dirty(const char *where, unsigned int line,
186 handle_t *handle, struct inode *inode,
187 struct ext4_ext_path *path)
188{
189 int err;
190
191 WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
192 if (path->p_bh) {
193 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
194 /* path points to block */
195 err = __ext4_handle_dirty_metadata(where, line, handle,
196 inode, path->p_bh);
197 /* Extents updating done, re-set verified flag */
198 if (!err)
199 set_buffer_verified(path->p_bh);
200 } else {
201 /* path points to leaf/index in inode body */
202 err = ext4_mark_inode_dirty(handle, inode);
203 }
204 return err;
205}
206
207#define ext4_ext_dirty(handle, inode, path) \
208 __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
209
210static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
211 struct ext4_ext_path *path,
212 ext4_lblk_t block)
213{
214 if (path) {
215 int depth = path->p_depth;
216 struct ext4_extent *ex;
217
218 /*
219 * Try to predict block placement assuming that we are
220 * filling in a file which will eventually be
221 * non-sparse --- i.e., in the case of libbfd writing
222 * an ELF object sections out-of-order but in a way
223 * the eventually results in a contiguous object or
224 * executable file, or some database extending a table
225 * space file. However, this is actually somewhat
226 * non-ideal if we are writing a sparse file such as
227 * qemu or KVM writing a raw image file that is going
228 * to stay fairly sparse, since it will end up
229 * fragmenting the file system's free space. Maybe we
230 * should have some hueristics or some way to allow
231 * userspace to pass a hint to file system,
232 * especially if the latter case turns out to be
233 * common.
234 */
235 ex = path[depth].p_ext;
236 if (ex) {
237 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
238 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
239
240 if (block > ext_block)
241 return ext_pblk + (block - ext_block);
242 else
243 return ext_pblk - (ext_block - block);
244 }
245
246 /* it looks like index is empty;
247 * try to find starting block from index itself */
248 if (path[depth].p_bh)
249 return path[depth].p_bh->b_blocknr;
250 }
251
252 /* OK. use inode's group */
253 return ext4_inode_to_goal_block(inode);
254}
255
256/*
257 * Allocation for a meta data block
258 */
259static ext4_fsblk_t
260ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
261 struct ext4_ext_path *path,
262 struct ext4_extent *ex, int *err, unsigned int flags)
263{
264 ext4_fsblk_t goal, newblock;
265
266 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
267 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
268 NULL, err);
269 return newblock;
270}
271
272static inline int ext4_ext_space_block(struct inode *inode, int check)
273{
274 int size;
275
276 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
277 / sizeof(struct ext4_extent);
278#ifdef AGGRESSIVE_TEST
279 if (!check && size > 6)
280 size = 6;
281#endif
282 return size;
283}
284
285static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
286{
287 int size;
288
289 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
290 / sizeof(struct ext4_extent_idx);
291#ifdef AGGRESSIVE_TEST
292 if (!check && size > 5)
293 size = 5;
294#endif
295 return size;
296}
297
298static inline int ext4_ext_space_root(struct inode *inode, int check)
299{
300 int size;
301
302 size = sizeof(EXT4_I(inode)->i_data);
303 size -= sizeof(struct ext4_extent_header);
304 size /= sizeof(struct ext4_extent);
305#ifdef AGGRESSIVE_TEST
306 if (!check && size > 3)
307 size = 3;
308#endif
309 return size;
310}
311
312static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
313{
314 int size;
315
316 size = sizeof(EXT4_I(inode)->i_data);
317 size -= sizeof(struct ext4_extent_header);
318 size /= sizeof(struct ext4_extent_idx);
319#ifdef AGGRESSIVE_TEST
320 if (!check && size > 4)
321 size = 4;
322#endif
323 return size;
324}
325
326static inline int
327ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
328 struct ext4_ext_path **ppath, ext4_lblk_t lblk,
329 int nofail)
330{
331 struct ext4_ext_path *path = *ppath;
332 int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
333 int flags = EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO;
334
335 if (nofail)
336 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL | EXT4_EX_NOFAIL;
337
338 return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ?
339 EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
340 flags);
341}
342
343static int
344ext4_ext_max_entries(struct inode *inode, int depth)
345{
346 int max;
347
348 if (depth == ext_depth(inode)) {
349 if (depth == 0)
350 max = ext4_ext_space_root(inode, 1);
351 else
352 max = ext4_ext_space_root_idx(inode, 1);
353 } else {
354 if (depth == 0)
355 max = ext4_ext_space_block(inode, 1);
356 else
357 max = ext4_ext_space_block_idx(inode, 1);
358 }
359
360 return max;
361}
362
363static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
364{
365 ext4_fsblk_t block = ext4_ext_pblock(ext);
366 int len = ext4_ext_get_actual_len(ext);
367 ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
368
369 /*
370 * We allow neither:
371 * - zero length
372 * - overflow/wrap-around
373 */
374 if (lblock + len <= lblock)
375 return 0;
376 return ext4_inode_block_valid(inode, block, len);
377}
378
379static int ext4_valid_extent_idx(struct inode *inode,
380 struct ext4_extent_idx *ext_idx)
381{
382 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
383
384 return ext4_inode_block_valid(inode, block, 1);
385}
386
387static int ext4_valid_extent_entries(struct inode *inode,
388 struct ext4_extent_header *eh,
389 ext4_lblk_t lblk, ext4_fsblk_t *pblk,
390 int depth)
391{
392 unsigned short entries;
393 ext4_lblk_t lblock = 0;
394 ext4_lblk_t cur = 0;
395
396 if (eh->eh_entries == 0)
397 return 1;
398
399 entries = le16_to_cpu(eh->eh_entries);
400
401 if (depth == 0) {
402 /* leaf entries */
403 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
404
405 /*
406 * The logical block in the first entry should equal to
407 * the number in the index block.
408 */
409 if (depth != ext_depth(inode) &&
410 lblk != le32_to_cpu(ext->ee_block))
411 return 0;
412 while (entries) {
413 if (!ext4_valid_extent(inode, ext))
414 return 0;
415
416 /* Check for overlapping extents */
417 lblock = le32_to_cpu(ext->ee_block);
418 if (lblock < cur) {
419 *pblk = ext4_ext_pblock(ext);
420 return 0;
421 }
422 cur = lblock + ext4_ext_get_actual_len(ext);
423 ext++;
424 entries--;
425 }
426 } else {
427 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
428
429 /*
430 * The logical block in the first entry should equal to
431 * the number in the parent index block.
432 */
433 if (depth != ext_depth(inode) &&
434 lblk != le32_to_cpu(ext_idx->ei_block))
435 return 0;
436 while (entries) {
437 if (!ext4_valid_extent_idx(inode, ext_idx))
438 return 0;
439
440 /* Check for overlapping index extents */
441 lblock = le32_to_cpu(ext_idx->ei_block);
442 if (lblock < cur) {
443 *pblk = ext4_idx_pblock(ext_idx);
444 return 0;
445 }
446 ext_idx++;
447 entries--;
448 cur = lblock + 1;
449 }
450 }
451 return 1;
452}
453
454static int __ext4_ext_check(const char *function, unsigned int line,
455 struct inode *inode, struct ext4_extent_header *eh,
456 int depth, ext4_fsblk_t pblk, ext4_lblk_t lblk)
457{
458 const char *error_msg;
459 int max = 0, err = -EFSCORRUPTED;
460
461 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
462 error_msg = "invalid magic";
463 goto corrupted;
464 }
465 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
466 error_msg = "unexpected eh_depth";
467 goto corrupted;
468 }
469 if (unlikely(eh->eh_max == 0)) {
470 error_msg = "invalid eh_max";
471 goto corrupted;
472 }
473 max = ext4_ext_max_entries(inode, depth);
474 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
475 error_msg = "too large eh_max";
476 goto corrupted;
477 }
478 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
479 error_msg = "invalid eh_entries";
480 goto corrupted;
481 }
482 if (unlikely((eh->eh_entries == 0) && (depth > 0))) {
483 error_msg = "eh_entries is 0 but eh_depth is > 0";
484 goto corrupted;
485 }
486 if (!ext4_valid_extent_entries(inode, eh, lblk, &pblk, depth)) {
487 error_msg = "invalid extent entries";
488 goto corrupted;
489 }
490 if (unlikely(depth > 32)) {
491 error_msg = "too large eh_depth";
492 goto corrupted;
493 }
494 /* Verify checksum on non-root extent tree nodes */
495 if (ext_depth(inode) != depth &&
496 !ext4_extent_block_csum_verify(inode, eh)) {
497 error_msg = "extent tree corrupted";
498 err = -EFSBADCRC;
499 goto corrupted;
500 }
501 return 0;
502
503corrupted:
504 ext4_error_inode_err(inode, function, line, 0, -err,
505 "pblk %llu bad header/extent: %s - magic %x, "
506 "entries %u, max %u(%u), depth %u(%u)",
507 (unsigned long long) pblk, error_msg,
508 le16_to_cpu(eh->eh_magic),
509 le16_to_cpu(eh->eh_entries),
510 le16_to_cpu(eh->eh_max),
511 max, le16_to_cpu(eh->eh_depth), depth);
512 return err;
513}
514
515#define ext4_ext_check(inode, eh, depth, pblk) \
516 __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk), 0)
517
518int ext4_ext_check_inode(struct inode *inode)
519{
520 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
521}
522
523static void ext4_cache_extents(struct inode *inode,
524 struct ext4_extent_header *eh)
525{
526 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
527 ext4_lblk_t prev = 0;
528 int i;
529
530 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
531 unsigned int status = EXTENT_STATUS_WRITTEN;
532 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
533 int len = ext4_ext_get_actual_len(ex);
534
535 if (prev && (prev != lblk))
536 ext4_es_cache_extent(inode, prev, lblk - prev, ~0,
537 EXTENT_STATUS_HOLE);
538
539 if (ext4_ext_is_unwritten(ex))
540 status = EXTENT_STATUS_UNWRITTEN;
541 ext4_es_cache_extent(inode, lblk, len,
542 ext4_ext_pblock(ex), status);
543 prev = lblk + len;
544 }
545}
546
547static struct buffer_head *
548__read_extent_tree_block(const char *function, unsigned int line,
549 struct inode *inode, struct ext4_extent_idx *idx,
550 int depth, int flags)
551{
552 struct buffer_head *bh;
553 int err;
554 gfp_t gfp_flags = __GFP_MOVABLE | GFP_NOFS;
555 ext4_fsblk_t pblk;
556
557 if (flags & EXT4_EX_NOFAIL)
558 gfp_flags |= __GFP_NOFAIL;
559
560 pblk = ext4_idx_pblock(idx);
561 bh = sb_getblk_gfp(inode->i_sb, pblk, gfp_flags);
562 if (unlikely(!bh))
563 return ERR_PTR(-ENOMEM);
564
565 if (!bh_uptodate_or_lock(bh)) {
566 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
567 err = ext4_read_bh(bh, 0, NULL);
568 if (err < 0)
569 goto errout;
570 }
571 if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
572 return bh;
573 err = __ext4_ext_check(function, line, inode, ext_block_hdr(bh),
574 depth, pblk, le32_to_cpu(idx->ei_block));
575 if (err)
576 goto errout;
577 set_buffer_verified(bh);
578 /*
579 * If this is a leaf block, cache all of its entries
580 */
581 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
582 struct ext4_extent_header *eh = ext_block_hdr(bh);
583 ext4_cache_extents(inode, eh);
584 }
585 return bh;
586errout:
587 put_bh(bh);
588 return ERR_PTR(err);
589
590}
591
592#define read_extent_tree_block(inode, idx, depth, flags) \
593 __read_extent_tree_block(__func__, __LINE__, (inode), (idx), \
594 (depth), (flags))
595
596/*
597 * This function is called to cache a file's extent information in the
598 * extent status tree
599 */
600int ext4_ext_precache(struct inode *inode)
601{
602 struct ext4_inode_info *ei = EXT4_I(inode);
603 struct ext4_ext_path *path = NULL;
604 struct buffer_head *bh;
605 int i = 0, depth, ret = 0;
606
607 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
608 return 0; /* not an extent-mapped inode */
609
610 down_read(&ei->i_data_sem);
611 depth = ext_depth(inode);
612
613 /* Don't cache anything if there are no external extent blocks */
614 if (!depth) {
615 up_read(&ei->i_data_sem);
616 return ret;
617 }
618
619 path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
620 GFP_NOFS);
621 if (path == NULL) {
622 up_read(&ei->i_data_sem);
623 return -ENOMEM;
624 }
625
626 path[0].p_hdr = ext_inode_hdr(inode);
627 ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
628 if (ret)
629 goto out;
630 path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
631 while (i >= 0) {
632 /*
633 * If this is a leaf block or we've reached the end of
634 * the index block, go up
635 */
636 if ((i == depth) ||
637 path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
638 brelse(path[i].p_bh);
639 path[i].p_bh = NULL;
640 i--;
641 continue;
642 }
643 bh = read_extent_tree_block(inode, path[i].p_idx++,
644 depth - i - 1,
645 EXT4_EX_FORCE_CACHE);
646 if (IS_ERR(bh)) {
647 ret = PTR_ERR(bh);
648 break;
649 }
650 i++;
651 path[i].p_bh = bh;
652 path[i].p_hdr = ext_block_hdr(bh);
653 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
654 }
655 ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
656out:
657 up_read(&ei->i_data_sem);
658 ext4_free_ext_path(path);
659 return ret;
660}
661
662#ifdef EXT_DEBUG
663static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
664{
665 int k, l = path->p_depth;
666
667 ext_debug(inode, "path:");
668 for (k = 0; k <= l; k++, path++) {
669 if (path->p_idx) {
670 ext_debug(inode, " %d->%llu",
671 le32_to_cpu(path->p_idx->ei_block),
672 ext4_idx_pblock(path->p_idx));
673 } else if (path->p_ext) {
674 ext_debug(inode, " %d:[%d]%d:%llu ",
675 le32_to_cpu(path->p_ext->ee_block),
676 ext4_ext_is_unwritten(path->p_ext),
677 ext4_ext_get_actual_len(path->p_ext),
678 ext4_ext_pblock(path->p_ext));
679 } else
680 ext_debug(inode, " []");
681 }
682 ext_debug(inode, "\n");
683}
684
685static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
686{
687 int depth = ext_depth(inode);
688 struct ext4_extent_header *eh;
689 struct ext4_extent *ex;
690 int i;
691
692 if (!path)
693 return;
694
695 eh = path[depth].p_hdr;
696 ex = EXT_FIRST_EXTENT(eh);
697
698 ext_debug(inode, "Displaying leaf extents\n");
699
700 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
701 ext_debug(inode, "%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
702 ext4_ext_is_unwritten(ex),
703 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
704 }
705 ext_debug(inode, "\n");
706}
707
708static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
709 ext4_fsblk_t newblock, int level)
710{
711 int depth = ext_depth(inode);
712 struct ext4_extent *ex;
713
714 if (depth != level) {
715 struct ext4_extent_idx *idx;
716 idx = path[level].p_idx;
717 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
718 ext_debug(inode, "%d: move %d:%llu in new index %llu\n",
719 level, le32_to_cpu(idx->ei_block),
720 ext4_idx_pblock(idx), newblock);
721 idx++;
722 }
723
724 return;
725 }
726
727 ex = path[depth].p_ext;
728 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
729 ext_debug(inode, "move %d:%llu:[%d]%d in new leaf %llu\n",
730 le32_to_cpu(ex->ee_block),
731 ext4_ext_pblock(ex),
732 ext4_ext_is_unwritten(ex),
733 ext4_ext_get_actual_len(ex),
734 newblock);
735 ex++;
736 }
737}
738
739#else
740#define ext4_ext_show_path(inode, path)
741#define ext4_ext_show_leaf(inode, path)
742#define ext4_ext_show_move(inode, path, newblock, level)
743#endif
744
745/*
746 * ext4_ext_binsearch_idx:
747 * binary search for the closest index of the given block
748 * the header must be checked before calling this
749 */
750static void
751ext4_ext_binsearch_idx(struct inode *inode,
752 struct ext4_ext_path *path, ext4_lblk_t block)
753{
754 struct ext4_extent_header *eh = path->p_hdr;
755 struct ext4_extent_idx *r, *l, *m;
756
757
758 ext_debug(inode, "binsearch for %u(idx): ", block);
759
760 l = EXT_FIRST_INDEX(eh) + 1;
761 r = EXT_LAST_INDEX(eh);
762 while (l <= r) {
763 m = l + (r - l) / 2;
764 ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l,
765 le32_to_cpu(l->ei_block), m, le32_to_cpu(m->ei_block),
766 r, le32_to_cpu(r->ei_block));
767
768 if (block < le32_to_cpu(m->ei_block))
769 r = m - 1;
770 else
771 l = m + 1;
772 }
773
774 path->p_idx = l - 1;
775 ext_debug(inode, " -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
776 ext4_idx_pblock(path->p_idx));
777
778#ifdef CHECK_BINSEARCH
779 {
780 struct ext4_extent_idx *chix, *ix;
781 int k;
782
783 chix = ix = EXT_FIRST_INDEX(eh);
784 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
785 if (k != 0 && le32_to_cpu(ix->ei_block) <=
786 le32_to_cpu(ix[-1].ei_block)) {
787 printk(KERN_DEBUG "k=%d, ix=0x%p, "
788 "first=0x%p\n", k,
789 ix, EXT_FIRST_INDEX(eh));
790 printk(KERN_DEBUG "%u <= %u\n",
791 le32_to_cpu(ix->ei_block),
792 le32_to_cpu(ix[-1].ei_block));
793 }
794 BUG_ON(k && le32_to_cpu(ix->ei_block)
795 <= le32_to_cpu(ix[-1].ei_block));
796 if (block < le32_to_cpu(ix->ei_block))
797 break;
798 chix = ix;
799 }
800 BUG_ON(chix != path->p_idx);
801 }
802#endif
803
804}
805
806/*
807 * ext4_ext_binsearch:
808 * binary search for closest extent of the given block
809 * the header must be checked before calling this
810 */
811static void
812ext4_ext_binsearch(struct inode *inode,
813 struct ext4_ext_path *path, ext4_lblk_t block)
814{
815 struct ext4_extent_header *eh = path->p_hdr;
816 struct ext4_extent *r, *l, *m;
817
818 if (eh->eh_entries == 0) {
819 /*
820 * this leaf is empty:
821 * we get such a leaf in split/add case
822 */
823 return;
824 }
825
826 ext_debug(inode, "binsearch for %u: ", block);
827
828 l = EXT_FIRST_EXTENT(eh) + 1;
829 r = EXT_LAST_EXTENT(eh);
830
831 while (l <= r) {
832 m = l + (r - l) / 2;
833 ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l,
834 le32_to_cpu(l->ee_block), m, le32_to_cpu(m->ee_block),
835 r, le32_to_cpu(r->ee_block));
836
837 if (block < le32_to_cpu(m->ee_block))
838 r = m - 1;
839 else
840 l = m + 1;
841 }
842
843 path->p_ext = l - 1;
844 ext_debug(inode, " -> %d:%llu:[%d]%d ",
845 le32_to_cpu(path->p_ext->ee_block),
846 ext4_ext_pblock(path->p_ext),
847 ext4_ext_is_unwritten(path->p_ext),
848 ext4_ext_get_actual_len(path->p_ext));
849
850#ifdef CHECK_BINSEARCH
851 {
852 struct ext4_extent *chex, *ex;
853 int k;
854
855 chex = ex = EXT_FIRST_EXTENT(eh);
856 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
857 BUG_ON(k && le32_to_cpu(ex->ee_block)
858 <= le32_to_cpu(ex[-1].ee_block));
859 if (block < le32_to_cpu(ex->ee_block))
860 break;
861 chex = ex;
862 }
863 BUG_ON(chex != path->p_ext);
864 }
865#endif
866
867}
868
869void ext4_ext_tree_init(handle_t *handle, struct inode *inode)
870{
871 struct ext4_extent_header *eh;
872
873 eh = ext_inode_hdr(inode);
874 eh->eh_depth = 0;
875 eh->eh_entries = 0;
876 eh->eh_magic = EXT4_EXT_MAGIC;
877 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
878 eh->eh_generation = 0;
879 ext4_mark_inode_dirty(handle, inode);
880}
881
882struct ext4_ext_path *
883ext4_find_extent(struct inode *inode, ext4_lblk_t block,
884 struct ext4_ext_path **orig_path, int flags)
885{
886 struct ext4_extent_header *eh;
887 struct buffer_head *bh;
888 struct ext4_ext_path *path = orig_path ? *orig_path : NULL;
889 short int depth, i, ppos = 0;
890 int ret;
891 gfp_t gfp_flags = GFP_NOFS;
892
893 if (flags & EXT4_EX_NOFAIL)
894 gfp_flags |= __GFP_NOFAIL;
895
896 eh = ext_inode_hdr(inode);
897 depth = ext_depth(inode);
898 if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) {
899 EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d",
900 depth);
901 ret = -EFSCORRUPTED;
902 goto err;
903 }
904
905 if (path) {
906 ext4_ext_drop_refs(path);
907 if (depth > path[0].p_maxdepth) {
908 kfree(path);
909 *orig_path = path = NULL;
910 }
911 }
912 if (!path) {
913 /* account possible depth increase */
914 path = kcalloc(depth + 2, sizeof(struct ext4_ext_path),
915 gfp_flags);
916 if (unlikely(!path))
917 return ERR_PTR(-ENOMEM);
918 path[0].p_maxdepth = depth + 1;
919 }
920 path[0].p_hdr = eh;
921 path[0].p_bh = NULL;
922
923 i = depth;
924 if (!(flags & EXT4_EX_NOCACHE) && depth == 0)
925 ext4_cache_extents(inode, eh);
926 /* walk through the tree */
927 while (i) {
928 ext_debug(inode, "depth %d: num %d, max %d\n",
929 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
930
931 ext4_ext_binsearch_idx(inode, path + ppos, block);
932 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
933 path[ppos].p_depth = i;
934 path[ppos].p_ext = NULL;
935
936 bh = read_extent_tree_block(inode, path[ppos].p_idx, --i, flags);
937 if (IS_ERR(bh)) {
938 ret = PTR_ERR(bh);
939 goto err;
940 }
941
942 eh = ext_block_hdr(bh);
943 ppos++;
944 path[ppos].p_bh = bh;
945 path[ppos].p_hdr = eh;
946 }
947
948 path[ppos].p_depth = i;
949 path[ppos].p_ext = NULL;
950 path[ppos].p_idx = NULL;
951
952 /* find extent */
953 ext4_ext_binsearch(inode, path + ppos, block);
954 /* if not an empty leaf */
955 if (path[ppos].p_ext)
956 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
957
958 ext4_ext_show_path(inode, path);
959
960 return path;
961
962err:
963 ext4_free_ext_path(path);
964 if (orig_path)
965 *orig_path = NULL;
966 return ERR_PTR(ret);
967}
968
969/*
970 * ext4_ext_insert_index:
971 * insert new index [@logical;@ptr] into the block at @curp;
972 * check where to insert: before @curp or after @curp
973 */
974static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
975 struct ext4_ext_path *curp,
976 int logical, ext4_fsblk_t ptr)
977{
978 struct ext4_extent_idx *ix;
979 int len, err;
980
981 err = ext4_ext_get_access(handle, inode, curp);
982 if (err)
983 return err;
984
985 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
986 EXT4_ERROR_INODE(inode,
987 "logical %d == ei_block %d!",
988 logical, le32_to_cpu(curp->p_idx->ei_block));
989 return -EFSCORRUPTED;
990 }
991
992 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
993 >= le16_to_cpu(curp->p_hdr->eh_max))) {
994 EXT4_ERROR_INODE(inode,
995 "eh_entries %d >= eh_max %d!",
996 le16_to_cpu(curp->p_hdr->eh_entries),
997 le16_to_cpu(curp->p_hdr->eh_max));
998 return -EFSCORRUPTED;
999 }
1000
1001 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
1002 /* insert after */
1003 ext_debug(inode, "insert new index %d after: %llu\n",
1004 logical, ptr);
1005 ix = curp->p_idx + 1;
1006 } else {
1007 /* insert before */
1008 ext_debug(inode, "insert new index %d before: %llu\n",
1009 logical, ptr);
1010 ix = curp->p_idx;
1011 }
1012
1013 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
1014 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
1015 return -EFSCORRUPTED;
1016 }
1017
1018 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
1019 BUG_ON(len < 0);
1020 if (len > 0) {
1021 ext_debug(inode, "insert new index %d: "
1022 "move %d indices from 0x%p to 0x%p\n",
1023 logical, len, ix, ix + 1);
1024 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
1025 }
1026
1027 ix->ei_block = cpu_to_le32(logical);
1028 ext4_idx_store_pblock(ix, ptr);
1029 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
1030
1031 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
1032 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
1033 return -EFSCORRUPTED;
1034 }
1035
1036 err = ext4_ext_dirty(handle, inode, curp);
1037 ext4_std_error(inode->i_sb, err);
1038
1039 return err;
1040}
1041
1042/*
1043 * ext4_ext_split:
1044 * inserts new subtree into the path, using free index entry
1045 * at depth @at:
1046 * - allocates all needed blocks (new leaf and all intermediate index blocks)
1047 * - makes decision where to split
1048 * - moves remaining extents and index entries (right to the split point)
1049 * into the newly allocated blocks
1050 * - initializes subtree
1051 */
1052static int ext4_ext_split(handle_t *handle, struct inode *inode,
1053 unsigned int flags,
1054 struct ext4_ext_path *path,
1055 struct ext4_extent *newext, int at)
1056{
1057 struct buffer_head *bh = NULL;
1058 int depth = ext_depth(inode);
1059 struct ext4_extent_header *neh;
1060 struct ext4_extent_idx *fidx;
1061 int i = at, k, m, a;
1062 ext4_fsblk_t newblock, oldblock;
1063 __le32 border;
1064 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1065 gfp_t gfp_flags = GFP_NOFS;
1066 int err = 0;
1067 size_t ext_size = 0;
1068
1069 if (flags & EXT4_EX_NOFAIL)
1070 gfp_flags |= __GFP_NOFAIL;
1071
1072 /* make decision: where to split? */
1073 /* FIXME: now decision is simplest: at current extent */
1074
1075 /* if current leaf will be split, then we should use
1076 * border from split point */
1077 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1078 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1079 return -EFSCORRUPTED;
1080 }
1081 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1082 border = path[depth].p_ext[1].ee_block;
1083 ext_debug(inode, "leaf will be split."
1084 " next leaf starts at %d\n",
1085 le32_to_cpu(border));
1086 } else {
1087 border = newext->ee_block;
1088 ext_debug(inode, "leaf will be added."
1089 " next leaf starts at %d\n",
1090 le32_to_cpu(border));
1091 }
1092
1093 /*
1094 * If error occurs, then we break processing
1095 * and mark filesystem read-only. index won't
1096 * be inserted and tree will be in consistent
1097 * state. Next mount will repair buffers too.
1098 */
1099
1100 /*
1101 * Get array to track all allocated blocks.
1102 * We need this to handle errors and free blocks
1103 * upon them.
1104 */
1105 ablocks = kcalloc(depth, sizeof(ext4_fsblk_t), gfp_flags);
1106 if (!ablocks)
1107 return -ENOMEM;
1108
1109 /* allocate all needed blocks */
1110 ext_debug(inode, "allocate %d blocks for indexes/leaf\n", depth - at);
1111 for (a = 0; a < depth - at; a++) {
1112 newblock = ext4_ext_new_meta_block(handle, inode, path,
1113 newext, &err, flags);
1114 if (newblock == 0)
1115 goto cleanup;
1116 ablocks[a] = newblock;
1117 }
1118
1119 /* initialize new leaf */
1120 newblock = ablocks[--a];
1121 if (unlikely(newblock == 0)) {
1122 EXT4_ERROR_INODE(inode, "newblock == 0!");
1123 err = -EFSCORRUPTED;
1124 goto cleanup;
1125 }
1126 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1127 if (unlikely(!bh)) {
1128 err = -ENOMEM;
1129 goto cleanup;
1130 }
1131 lock_buffer(bh);
1132
1133 err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1134 EXT4_JTR_NONE);
1135 if (err)
1136 goto cleanup;
1137
1138 neh = ext_block_hdr(bh);
1139 neh->eh_entries = 0;
1140 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1141 neh->eh_magic = EXT4_EXT_MAGIC;
1142 neh->eh_depth = 0;
1143 neh->eh_generation = 0;
1144
1145 /* move remainder of path[depth] to the new leaf */
1146 if (unlikely(path[depth].p_hdr->eh_entries !=
1147 path[depth].p_hdr->eh_max)) {
1148 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1149 path[depth].p_hdr->eh_entries,
1150 path[depth].p_hdr->eh_max);
1151 err = -EFSCORRUPTED;
1152 goto cleanup;
1153 }
1154 /* start copy from next extent */
1155 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1156 ext4_ext_show_move(inode, path, newblock, depth);
1157 if (m) {
1158 struct ext4_extent *ex;
1159 ex = EXT_FIRST_EXTENT(neh);
1160 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1161 le16_add_cpu(&neh->eh_entries, m);
1162 }
1163
1164 /* zero out unused area in the extent block */
1165 ext_size = sizeof(struct ext4_extent_header) +
1166 sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries);
1167 memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
1168 ext4_extent_block_csum_set(inode, neh);
1169 set_buffer_uptodate(bh);
1170 unlock_buffer(bh);
1171
1172 err = ext4_handle_dirty_metadata(handle, inode, bh);
1173 if (err)
1174 goto cleanup;
1175 brelse(bh);
1176 bh = NULL;
1177
1178 /* correct old leaf */
1179 if (m) {
1180 err = ext4_ext_get_access(handle, inode, path + depth);
1181 if (err)
1182 goto cleanup;
1183 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1184 err = ext4_ext_dirty(handle, inode, path + depth);
1185 if (err)
1186 goto cleanup;
1187
1188 }
1189
1190 /* create intermediate indexes */
1191 k = depth - at - 1;
1192 if (unlikely(k < 0)) {
1193 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1194 err = -EFSCORRUPTED;
1195 goto cleanup;
1196 }
1197 if (k)
1198 ext_debug(inode, "create %d intermediate indices\n", k);
1199 /* insert new index into current index block */
1200 /* current depth stored in i var */
1201 i = depth - 1;
1202 while (k--) {
1203 oldblock = newblock;
1204 newblock = ablocks[--a];
1205 bh = sb_getblk(inode->i_sb, newblock);
1206 if (unlikely(!bh)) {
1207 err = -ENOMEM;
1208 goto cleanup;
1209 }
1210 lock_buffer(bh);
1211
1212 err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1213 EXT4_JTR_NONE);
1214 if (err)
1215 goto cleanup;
1216
1217 neh = ext_block_hdr(bh);
1218 neh->eh_entries = cpu_to_le16(1);
1219 neh->eh_magic = EXT4_EXT_MAGIC;
1220 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1221 neh->eh_depth = cpu_to_le16(depth - i);
1222 neh->eh_generation = 0;
1223 fidx = EXT_FIRST_INDEX(neh);
1224 fidx->ei_block = border;
1225 ext4_idx_store_pblock(fidx, oldblock);
1226
1227 ext_debug(inode, "int.index at %d (block %llu): %u -> %llu\n",
1228 i, newblock, le32_to_cpu(border), oldblock);
1229
1230 /* move remainder of path[i] to the new index block */
1231 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1232 EXT_LAST_INDEX(path[i].p_hdr))) {
1233 EXT4_ERROR_INODE(inode,
1234 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1235 le32_to_cpu(path[i].p_ext->ee_block));
1236 err = -EFSCORRUPTED;
1237 goto cleanup;
1238 }
1239 /* start copy indexes */
1240 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1241 ext_debug(inode, "cur 0x%p, last 0x%p\n", path[i].p_idx,
1242 EXT_MAX_INDEX(path[i].p_hdr));
1243 ext4_ext_show_move(inode, path, newblock, i);
1244 if (m) {
1245 memmove(++fidx, path[i].p_idx,
1246 sizeof(struct ext4_extent_idx) * m);
1247 le16_add_cpu(&neh->eh_entries, m);
1248 }
1249 /* zero out unused area in the extent block */
1250 ext_size = sizeof(struct ext4_extent_header) +
1251 (sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries));
1252 memset(bh->b_data + ext_size, 0,
1253 inode->i_sb->s_blocksize - ext_size);
1254 ext4_extent_block_csum_set(inode, neh);
1255 set_buffer_uptodate(bh);
1256 unlock_buffer(bh);
1257
1258 err = ext4_handle_dirty_metadata(handle, inode, bh);
1259 if (err)
1260 goto cleanup;
1261 brelse(bh);
1262 bh = NULL;
1263
1264 /* correct old index */
1265 if (m) {
1266 err = ext4_ext_get_access(handle, inode, path + i);
1267 if (err)
1268 goto cleanup;
1269 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1270 err = ext4_ext_dirty(handle, inode, path + i);
1271 if (err)
1272 goto cleanup;
1273 }
1274
1275 i--;
1276 }
1277
1278 /* insert new index */
1279 err = ext4_ext_insert_index(handle, inode, path + at,
1280 le32_to_cpu(border), newblock);
1281
1282cleanup:
1283 if (bh) {
1284 if (buffer_locked(bh))
1285 unlock_buffer(bh);
1286 brelse(bh);
1287 }
1288
1289 if (err) {
1290 /* free all allocated blocks in error case */
1291 for (i = 0; i < depth; i++) {
1292 if (!ablocks[i])
1293 continue;
1294 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1295 EXT4_FREE_BLOCKS_METADATA);
1296 }
1297 }
1298 kfree(ablocks);
1299
1300 return err;
1301}
1302
1303/*
1304 * ext4_ext_grow_indepth:
1305 * implements tree growing procedure:
1306 * - allocates new block
1307 * - moves top-level data (index block or leaf) into the new block
1308 * - initializes new top-level, creating index that points to the
1309 * just created block
1310 */
1311static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1312 unsigned int flags)
1313{
1314 struct ext4_extent_header *neh;
1315 struct buffer_head *bh;
1316 ext4_fsblk_t newblock, goal = 0;
1317 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
1318 int err = 0;
1319 size_t ext_size = 0;
1320
1321 /* Try to prepend new index to old one */
1322 if (ext_depth(inode))
1323 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
1324 if (goal > le32_to_cpu(es->s_first_data_block)) {
1325 flags |= EXT4_MB_HINT_TRY_GOAL;
1326 goal--;
1327 } else
1328 goal = ext4_inode_to_goal_block(inode);
1329 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
1330 NULL, &err);
1331 if (newblock == 0)
1332 return err;
1333
1334 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1335 if (unlikely(!bh))
1336 return -ENOMEM;
1337 lock_buffer(bh);
1338
1339 err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1340 EXT4_JTR_NONE);
1341 if (err) {
1342 unlock_buffer(bh);
1343 goto out;
1344 }
1345
1346 ext_size = sizeof(EXT4_I(inode)->i_data);
1347 /* move top-level index/leaf into new block */
1348 memmove(bh->b_data, EXT4_I(inode)->i_data, ext_size);
1349 /* zero out unused area in the extent block */
1350 memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
1351
1352 /* set size of new block */
1353 neh = ext_block_hdr(bh);
1354 /* old root could have indexes or leaves
1355 * so calculate e_max right way */
1356 if (ext_depth(inode))
1357 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1358 else
1359 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1360 neh->eh_magic = EXT4_EXT_MAGIC;
1361 ext4_extent_block_csum_set(inode, neh);
1362 set_buffer_uptodate(bh);
1363 set_buffer_verified(bh);
1364 unlock_buffer(bh);
1365
1366 err = ext4_handle_dirty_metadata(handle, inode, bh);
1367 if (err)
1368 goto out;
1369
1370 /* Update top-level index: num,max,pointer */
1371 neh = ext_inode_hdr(inode);
1372 neh->eh_entries = cpu_to_le16(1);
1373 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1374 if (neh->eh_depth == 0) {
1375 /* Root extent block becomes index block */
1376 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1377 EXT_FIRST_INDEX(neh)->ei_block =
1378 EXT_FIRST_EXTENT(neh)->ee_block;
1379 }
1380 ext_debug(inode, "new root: num %d(%d), lblock %d, ptr %llu\n",
1381 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1382 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1383 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1384
1385 le16_add_cpu(&neh->eh_depth, 1);
1386 err = ext4_mark_inode_dirty(handle, inode);
1387out:
1388 brelse(bh);
1389
1390 return err;
1391}
1392
1393/*
1394 * ext4_ext_create_new_leaf:
1395 * finds empty index and adds new leaf.
1396 * if no free index is found, then it requests in-depth growing.
1397 */
1398static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1399 unsigned int mb_flags,
1400 unsigned int gb_flags,
1401 struct ext4_ext_path **ppath,
1402 struct ext4_extent *newext)
1403{
1404 struct ext4_ext_path *path = *ppath;
1405 struct ext4_ext_path *curp;
1406 int depth, i, err = 0;
1407
1408repeat:
1409 i = depth = ext_depth(inode);
1410
1411 /* walk up to the tree and look for free index entry */
1412 curp = path + depth;
1413 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1414 i--;
1415 curp--;
1416 }
1417
1418 /* we use already allocated block for index block,
1419 * so subsequent data blocks should be contiguous */
1420 if (EXT_HAS_FREE_INDEX(curp)) {
1421 /* if we found index with free entry, then use that
1422 * entry: create all needed subtree and add new leaf */
1423 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
1424 if (err)
1425 goto out;
1426
1427 /* refill path */
1428 path = ext4_find_extent(inode,
1429 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1430 ppath, gb_flags);
1431 if (IS_ERR(path))
1432 err = PTR_ERR(path);
1433 } else {
1434 /* tree is full, time to grow in depth */
1435 err = ext4_ext_grow_indepth(handle, inode, mb_flags);
1436 if (err)
1437 goto out;
1438
1439 /* refill path */
1440 path = ext4_find_extent(inode,
1441 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1442 ppath, gb_flags);
1443 if (IS_ERR(path)) {
1444 err = PTR_ERR(path);
1445 goto out;
1446 }
1447
1448 /*
1449 * only first (depth 0 -> 1) produces free space;
1450 * in all other cases we have to split the grown tree
1451 */
1452 depth = ext_depth(inode);
1453 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1454 /* now we need to split */
1455 goto repeat;
1456 }
1457 }
1458
1459out:
1460 return err;
1461}
1462
1463/*
1464 * search the closest allocated block to the left for *logical
1465 * and returns it at @logical + it's physical address at @phys
1466 * if *logical is the smallest allocated block, the function
1467 * returns 0 at @phys
1468 * return value contains 0 (success) or error code
1469 */
1470static int ext4_ext_search_left(struct inode *inode,
1471 struct ext4_ext_path *path,
1472 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1473{
1474 struct ext4_extent_idx *ix;
1475 struct ext4_extent *ex;
1476 int depth, ee_len;
1477
1478 if (unlikely(path == NULL)) {
1479 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1480 return -EFSCORRUPTED;
1481 }
1482 depth = path->p_depth;
1483 *phys = 0;
1484
1485 if (depth == 0 && path->p_ext == NULL)
1486 return 0;
1487
1488 /* usually extent in the path covers blocks smaller
1489 * then *logical, but it can be that extent is the
1490 * first one in the file */
1491
1492 ex = path[depth].p_ext;
1493 ee_len = ext4_ext_get_actual_len(ex);
1494 if (*logical < le32_to_cpu(ex->ee_block)) {
1495 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1496 EXT4_ERROR_INODE(inode,
1497 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1498 *logical, le32_to_cpu(ex->ee_block));
1499 return -EFSCORRUPTED;
1500 }
1501 while (--depth >= 0) {
1502 ix = path[depth].p_idx;
1503 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1504 EXT4_ERROR_INODE(inode,
1505 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1506 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1507 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block),
1508 depth);
1509 return -EFSCORRUPTED;
1510 }
1511 }
1512 return 0;
1513 }
1514
1515 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1516 EXT4_ERROR_INODE(inode,
1517 "logical %d < ee_block %d + ee_len %d!",
1518 *logical, le32_to_cpu(ex->ee_block), ee_len);
1519 return -EFSCORRUPTED;
1520 }
1521
1522 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1523 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1524 return 0;
1525}
1526
1527/*
1528 * Search the closest allocated block to the right for *logical
1529 * and returns it at @logical + it's physical address at @phys.
1530 * If not exists, return 0 and @phys is set to 0. We will return
1531 * 1 which means we found an allocated block and ret_ex is valid.
1532 * Or return a (< 0) error code.
1533 */
1534static int ext4_ext_search_right(struct inode *inode,
1535 struct ext4_ext_path *path,
1536 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1537 struct ext4_extent *ret_ex)
1538{
1539 struct buffer_head *bh = NULL;
1540 struct ext4_extent_header *eh;
1541 struct ext4_extent_idx *ix;
1542 struct ext4_extent *ex;
1543 int depth; /* Note, NOT eh_depth; depth from top of tree */
1544 int ee_len;
1545
1546 if (unlikely(path == NULL)) {
1547 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1548 return -EFSCORRUPTED;
1549 }
1550 depth = path->p_depth;
1551 *phys = 0;
1552
1553 if (depth == 0 && path->p_ext == NULL)
1554 return 0;
1555
1556 /* usually extent in the path covers blocks smaller
1557 * then *logical, but it can be that extent is the
1558 * first one in the file */
1559
1560 ex = path[depth].p_ext;
1561 ee_len = ext4_ext_get_actual_len(ex);
1562 if (*logical < le32_to_cpu(ex->ee_block)) {
1563 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1564 EXT4_ERROR_INODE(inode,
1565 "first_extent(path[%d].p_hdr) != ex",
1566 depth);
1567 return -EFSCORRUPTED;
1568 }
1569 while (--depth >= 0) {
1570 ix = path[depth].p_idx;
1571 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1572 EXT4_ERROR_INODE(inode,
1573 "ix != EXT_FIRST_INDEX *logical %d!",
1574 *logical);
1575 return -EFSCORRUPTED;
1576 }
1577 }
1578 goto found_extent;
1579 }
1580
1581 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1582 EXT4_ERROR_INODE(inode,
1583 "logical %d < ee_block %d + ee_len %d!",
1584 *logical, le32_to_cpu(ex->ee_block), ee_len);
1585 return -EFSCORRUPTED;
1586 }
1587
1588 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1589 /* next allocated block in this leaf */
1590 ex++;
1591 goto found_extent;
1592 }
1593
1594 /* go up and search for index to the right */
1595 while (--depth >= 0) {
1596 ix = path[depth].p_idx;
1597 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1598 goto got_index;
1599 }
1600
1601 /* we've gone up to the root and found no index to the right */
1602 return 0;
1603
1604got_index:
1605 /* we've found index to the right, let's
1606 * follow it and find the closest allocated
1607 * block to the right */
1608 ix++;
1609 while (++depth < path->p_depth) {
1610 /* subtract from p_depth to get proper eh_depth */
1611 bh = read_extent_tree_block(inode, ix, path->p_depth - depth, 0);
1612 if (IS_ERR(bh))
1613 return PTR_ERR(bh);
1614 eh = ext_block_hdr(bh);
1615 ix = EXT_FIRST_INDEX(eh);
1616 put_bh(bh);
1617 }
1618
1619 bh = read_extent_tree_block(inode, ix, path->p_depth - depth, 0);
1620 if (IS_ERR(bh))
1621 return PTR_ERR(bh);
1622 eh = ext_block_hdr(bh);
1623 ex = EXT_FIRST_EXTENT(eh);
1624found_extent:
1625 *logical = le32_to_cpu(ex->ee_block);
1626 *phys = ext4_ext_pblock(ex);
1627 if (ret_ex)
1628 *ret_ex = *ex;
1629 if (bh)
1630 put_bh(bh);
1631 return 1;
1632}
1633
1634/*
1635 * ext4_ext_next_allocated_block:
1636 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1637 * NOTE: it considers block number from index entry as
1638 * allocated block. Thus, index entries have to be consistent
1639 * with leaves.
1640 */
1641ext4_lblk_t
1642ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1643{
1644 int depth;
1645
1646 BUG_ON(path == NULL);
1647 depth = path->p_depth;
1648
1649 if (depth == 0 && path->p_ext == NULL)
1650 return EXT_MAX_BLOCKS;
1651
1652 while (depth >= 0) {
1653 struct ext4_ext_path *p = &path[depth];
1654
1655 if (depth == path->p_depth) {
1656 /* leaf */
1657 if (p->p_ext && p->p_ext != EXT_LAST_EXTENT(p->p_hdr))
1658 return le32_to_cpu(p->p_ext[1].ee_block);
1659 } else {
1660 /* index */
1661 if (p->p_idx != EXT_LAST_INDEX(p->p_hdr))
1662 return le32_to_cpu(p->p_idx[1].ei_block);
1663 }
1664 depth--;
1665 }
1666
1667 return EXT_MAX_BLOCKS;
1668}
1669
1670/*
1671 * ext4_ext_next_leaf_block:
1672 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1673 */
1674static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1675{
1676 int depth;
1677
1678 BUG_ON(path == NULL);
1679 depth = path->p_depth;
1680
1681 /* zero-tree has no leaf blocks at all */
1682 if (depth == 0)
1683 return EXT_MAX_BLOCKS;
1684
1685 /* go to index block */
1686 depth--;
1687
1688 while (depth >= 0) {
1689 if (path[depth].p_idx !=
1690 EXT_LAST_INDEX(path[depth].p_hdr))
1691 return (ext4_lblk_t)
1692 le32_to_cpu(path[depth].p_idx[1].ei_block);
1693 depth--;
1694 }
1695
1696 return EXT_MAX_BLOCKS;
1697}
1698
1699/*
1700 * ext4_ext_correct_indexes:
1701 * if leaf gets modified and modified extent is first in the leaf,
1702 * then we have to correct all indexes above.
1703 * TODO: do we need to correct tree in all cases?
1704 */
1705static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1706 struct ext4_ext_path *path)
1707{
1708 struct ext4_extent_header *eh;
1709 int depth = ext_depth(inode);
1710 struct ext4_extent *ex;
1711 __le32 border;
1712 int k, err = 0;
1713
1714 eh = path[depth].p_hdr;
1715 ex = path[depth].p_ext;
1716
1717 if (unlikely(ex == NULL || eh == NULL)) {
1718 EXT4_ERROR_INODE(inode,
1719 "ex %p == NULL or eh %p == NULL", ex, eh);
1720 return -EFSCORRUPTED;
1721 }
1722
1723 if (depth == 0) {
1724 /* there is no tree at all */
1725 return 0;
1726 }
1727
1728 if (ex != EXT_FIRST_EXTENT(eh)) {
1729 /* we correct tree if first leaf got modified only */
1730 return 0;
1731 }
1732
1733 /*
1734 * TODO: we need correction if border is smaller than current one
1735 */
1736 k = depth - 1;
1737 border = path[depth].p_ext->ee_block;
1738 err = ext4_ext_get_access(handle, inode, path + k);
1739 if (err)
1740 return err;
1741 path[k].p_idx->ei_block = border;
1742 err = ext4_ext_dirty(handle, inode, path + k);
1743 if (err)
1744 return err;
1745
1746 while (k--) {
1747 /* change all left-side indexes */
1748 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1749 break;
1750 err = ext4_ext_get_access(handle, inode, path + k);
1751 if (err)
1752 break;
1753 path[k].p_idx->ei_block = border;
1754 err = ext4_ext_dirty(handle, inode, path + k);
1755 if (err)
1756 break;
1757 }
1758
1759 return err;
1760}
1761
1762static int ext4_can_extents_be_merged(struct inode *inode,
1763 struct ext4_extent *ex1,
1764 struct ext4_extent *ex2)
1765{
1766 unsigned short ext1_ee_len, ext2_ee_len;
1767
1768 if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
1769 return 0;
1770
1771 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1772 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1773
1774 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1775 le32_to_cpu(ex2->ee_block))
1776 return 0;
1777
1778 if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1779 return 0;
1780
1781 if (ext4_ext_is_unwritten(ex1) &&
1782 ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)
1783 return 0;
1784#ifdef AGGRESSIVE_TEST
1785 if (ext1_ee_len >= 4)
1786 return 0;
1787#endif
1788
1789 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1790 return 1;
1791 return 0;
1792}
1793
1794/*
1795 * This function tries to merge the "ex" extent to the next extent in the tree.
1796 * It always tries to merge towards right. If you want to merge towards
1797 * left, pass "ex - 1" as argument instead of "ex".
1798 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1799 * 1 if they got merged.
1800 */
1801static int ext4_ext_try_to_merge_right(struct inode *inode,
1802 struct ext4_ext_path *path,
1803 struct ext4_extent *ex)
1804{
1805 struct ext4_extent_header *eh;
1806 unsigned int depth, len;
1807 int merge_done = 0, unwritten;
1808
1809 depth = ext_depth(inode);
1810 BUG_ON(path[depth].p_hdr == NULL);
1811 eh = path[depth].p_hdr;
1812
1813 while (ex < EXT_LAST_EXTENT(eh)) {
1814 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1815 break;
1816 /* merge with next extent! */
1817 unwritten = ext4_ext_is_unwritten(ex);
1818 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1819 + ext4_ext_get_actual_len(ex + 1));
1820 if (unwritten)
1821 ext4_ext_mark_unwritten(ex);
1822
1823 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1824 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1825 * sizeof(struct ext4_extent);
1826 memmove(ex + 1, ex + 2, len);
1827 }
1828 le16_add_cpu(&eh->eh_entries, -1);
1829 merge_done = 1;
1830 WARN_ON(eh->eh_entries == 0);
1831 if (!eh->eh_entries)
1832 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1833 }
1834
1835 return merge_done;
1836}
1837
1838/*
1839 * This function does a very simple check to see if we can collapse
1840 * an extent tree with a single extent tree leaf block into the inode.
1841 */
1842static void ext4_ext_try_to_merge_up(handle_t *handle,
1843 struct inode *inode,
1844 struct ext4_ext_path *path)
1845{
1846 size_t s;
1847 unsigned max_root = ext4_ext_space_root(inode, 0);
1848 ext4_fsblk_t blk;
1849
1850 if ((path[0].p_depth != 1) ||
1851 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1852 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1853 return;
1854
1855 /*
1856 * We need to modify the block allocation bitmap and the block
1857 * group descriptor to release the extent tree block. If we
1858 * can't get the journal credits, give up.
1859 */
1860 if (ext4_journal_extend(handle, 2,
1861 ext4_free_metadata_revoke_credits(inode->i_sb, 1)))
1862 return;
1863
1864 /*
1865 * Copy the extent data up to the inode
1866 */
1867 blk = ext4_idx_pblock(path[0].p_idx);
1868 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1869 sizeof(struct ext4_extent_idx);
1870 s += sizeof(struct ext4_extent_header);
1871
1872 path[1].p_maxdepth = path[0].p_maxdepth;
1873 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1874 path[0].p_depth = 0;
1875 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1876 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1877 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1878
1879 brelse(path[1].p_bh);
1880 ext4_free_blocks(handle, inode, NULL, blk, 1,
1881 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1882}
1883
1884/*
1885 * This function tries to merge the @ex extent to neighbours in the tree, then
1886 * tries to collapse the extent tree into the inode.
1887 */
1888static void ext4_ext_try_to_merge(handle_t *handle,
1889 struct inode *inode,
1890 struct ext4_ext_path *path,
1891 struct ext4_extent *ex)
1892{
1893 struct ext4_extent_header *eh;
1894 unsigned int depth;
1895 int merge_done = 0;
1896
1897 depth = ext_depth(inode);
1898 BUG_ON(path[depth].p_hdr == NULL);
1899 eh = path[depth].p_hdr;
1900
1901 if (ex > EXT_FIRST_EXTENT(eh))
1902 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1903
1904 if (!merge_done)
1905 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1906
1907 ext4_ext_try_to_merge_up(handle, inode, path);
1908}
1909
1910/*
1911 * check if a portion of the "newext" extent overlaps with an
1912 * existing extent.
1913 *
1914 * If there is an overlap discovered, it updates the length of the newext
1915 * such that there will be no overlap, and then returns 1.
1916 * If there is no overlap found, it returns 0.
1917 */
1918static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1919 struct inode *inode,
1920 struct ext4_extent *newext,
1921 struct ext4_ext_path *path)
1922{
1923 ext4_lblk_t b1, b2;
1924 unsigned int depth, len1;
1925 unsigned int ret = 0;
1926
1927 b1 = le32_to_cpu(newext->ee_block);
1928 len1 = ext4_ext_get_actual_len(newext);
1929 depth = ext_depth(inode);
1930 if (!path[depth].p_ext)
1931 goto out;
1932 b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
1933
1934 /*
1935 * get the next allocated block if the extent in the path
1936 * is before the requested block(s)
1937 */
1938 if (b2 < b1) {
1939 b2 = ext4_ext_next_allocated_block(path);
1940 if (b2 == EXT_MAX_BLOCKS)
1941 goto out;
1942 b2 = EXT4_LBLK_CMASK(sbi, b2);
1943 }
1944
1945 /* check for wrap through zero on extent logical start block*/
1946 if (b1 + len1 < b1) {
1947 len1 = EXT_MAX_BLOCKS - b1;
1948 newext->ee_len = cpu_to_le16(len1);
1949 ret = 1;
1950 }
1951
1952 /* check for overlap */
1953 if (b1 + len1 > b2) {
1954 newext->ee_len = cpu_to_le16(b2 - b1);
1955 ret = 1;
1956 }
1957out:
1958 return ret;
1959}
1960
1961/*
1962 * ext4_ext_insert_extent:
1963 * tries to merge requested extent into the existing extent or
1964 * inserts requested extent as new one into the tree,
1965 * creating new leaf in the no-space case.
1966 */
1967int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1968 struct ext4_ext_path **ppath,
1969 struct ext4_extent *newext, int gb_flags)
1970{
1971 struct ext4_ext_path *path = *ppath;
1972 struct ext4_extent_header *eh;
1973 struct ext4_extent *ex, *fex;
1974 struct ext4_extent *nearex; /* nearest extent */
1975 struct ext4_ext_path *npath = NULL;
1976 int depth, len, err;
1977 ext4_lblk_t next;
1978 int mb_flags = 0, unwritten;
1979
1980 if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1981 mb_flags |= EXT4_MB_DELALLOC_RESERVED;
1982 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1983 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1984 return -EFSCORRUPTED;
1985 }
1986 depth = ext_depth(inode);
1987 ex = path[depth].p_ext;
1988 eh = path[depth].p_hdr;
1989 if (unlikely(path[depth].p_hdr == NULL)) {
1990 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1991 return -EFSCORRUPTED;
1992 }
1993
1994 /* try to insert block into found extent and return */
1995 if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
1996
1997 /*
1998 * Try to see whether we should rather test the extent on
1999 * right from ex, or from the left of ex. This is because
2000 * ext4_find_extent() can return either extent on the
2001 * left, or on the right from the searched position. This
2002 * will make merging more effective.
2003 */
2004 if (ex < EXT_LAST_EXTENT(eh) &&
2005 (le32_to_cpu(ex->ee_block) +
2006 ext4_ext_get_actual_len(ex) <
2007 le32_to_cpu(newext->ee_block))) {
2008 ex += 1;
2009 goto prepend;
2010 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
2011 (le32_to_cpu(newext->ee_block) +
2012 ext4_ext_get_actual_len(newext) <
2013 le32_to_cpu(ex->ee_block)))
2014 ex -= 1;
2015
2016 /* Try to append newex to the ex */
2017 if (ext4_can_extents_be_merged(inode, ex, newext)) {
2018 ext_debug(inode, "append [%d]%d block to %u:[%d]%d"
2019 "(from %llu)\n",
2020 ext4_ext_is_unwritten(newext),
2021 ext4_ext_get_actual_len(newext),
2022 le32_to_cpu(ex->ee_block),
2023 ext4_ext_is_unwritten(ex),
2024 ext4_ext_get_actual_len(ex),
2025 ext4_ext_pblock(ex));
2026 err = ext4_ext_get_access(handle, inode,
2027 path + depth);
2028 if (err)
2029 return err;
2030 unwritten = ext4_ext_is_unwritten(ex);
2031 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2032 + ext4_ext_get_actual_len(newext));
2033 if (unwritten)
2034 ext4_ext_mark_unwritten(ex);
2035 nearex = ex;
2036 goto merge;
2037 }
2038
2039prepend:
2040 /* Try to prepend newex to the ex */
2041 if (ext4_can_extents_be_merged(inode, newext, ex)) {
2042 ext_debug(inode, "prepend %u[%d]%d block to %u:[%d]%d"
2043 "(from %llu)\n",
2044 le32_to_cpu(newext->ee_block),
2045 ext4_ext_is_unwritten(newext),
2046 ext4_ext_get_actual_len(newext),
2047 le32_to_cpu(ex->ee_block),
2048 ext4_ext_is_unwritten(ex),
2049 ext4_ext_get_actual_len(ex),
2050 ext4_ext_pblock(ex));
2051 err = ext4_ext_get_access(handle, inode,
2052 path + depth);
2053 if (err)
2054 return err;
2055
2056 unwritten = ext4_ext_is_unwritten(ex);
2057 ex->ee_block = newext->ee_block;
2058 ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
2059 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2060 + ext4_ext_get_actual_len(newext));
2061 if (unwritten)
2062 ext4_ext_mark_unwritten(ex);
2063 nearex = ex;
2064 goto merge;
2065 }
2066 }
2067
2068 depth = ext_depth(inode);
2069 eh = path[depth].p_hdr;
2070 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
2071 goto has_space;
2072
2073 /* probably next leaf has space for us? */
2074 fex = EXT_LAST_EXTENT(eh);
2075 next = EXT_MAX_BLOCKS;
2076 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
2077 next = ext4_ext_next_leaf_block(path);
2078 if (next != EXT_MAX_BLOCKS) {
2079 ext_debug(inode, "next leaf block - %u\n", next);
2080 BUG_ON(npath != NULL);
2081 npath = ext4_find_extent(inode, next, NULL, gb_flags);
2082 if (IS_ERR(npath))
2083 return PTR_ERR(npath);
2084 BUG_ON(npath->p_depth != path->p_depth);
2085 eh = npath[depth].p_hdr;
2086 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2087 ext_debug(inode, "next leaf isn't full(%d)\n",
2088 le16_to_cpu(eh->eh_entries));
2089 path = npath;
2090 goto has_space;
2091 }
2092 ext_debug(inode, "next leaf has no free space(%d,%d)\n",
2093 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2094 }
2095
2096 /*
2097 * There is no free space in the found leaf.
2098 * We're gonna add a new leaf in the tree.
2099 */
2100 if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2101 mb_flags |= EXT4_MB_USE_RESERVED;
2102 err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2103 ppath, newext);
2104 if (err)
2105 goto cleanup;
2106 depth = ext_depth(inode);
2107 eh = path[depth].p_hdr;
2108
2109has_space:
2110 nearex = path[depth].p_ext;
2111
2112 err = ext4_ext_get_access(handle, inode, path + depth);
2113 if (err)
2114 goto cleanup;
2115
2116 if (!nearex) {
2117 /* there is no extent in this leaf, create first one */
2118 ext_debug(inode, "first extent in the leaf: %u:%llu:[%d]%d\n",
2119 le32_to_cpu(newext->ee_block),
2120 ext4_ext_pblock(newext),
2121 ext4_ext_is_unwritten(newext),
2122 ext4_ext_get_actual_len(newext));
2123 nearex = EXT_FIRST_EXTENT(eh);
2124 } else {
2125 if (le32_to_cpu(newext->ee_block)
2126 > le32_to_cpu(nearex->ee_block)) {
2127 /* Insert after */
2128 ext_debug(inode, "insert %u:%llu:[%d]%d before: "
2129 "nearest %p\n",
2130 le32_to_cpu(newext->ee_block),
2131 ext4_ext_pblock(newext),
2132 ext4_ext_is_unwritten(newext),
2133 ext4_ext_get_actual_len(newext),
2134 nearex);
2135 nearex++;
2136 } else {
2137 /* Insert before */
2138 BUG_ON(newext->ee_block == nearex->ee_block);
2139 ext_debug(inode, "insert %u:%llu:[%d]%d after: "
2140 "nearest %p\n",
2141 le32_to_cpu(newext->ee_block),
2142 ext4_ext_pblock(newext),
2143 ext4_ext_is_unwritten(newext),
2144 ext4_ext_get_actual_len(newext),
2145 nearex);
2146 }
2147 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2148 if (len > 0) {
2149 ext_debug(inode, "insert %u:%llu:[%d]%d: "
2150 "move %d extents from 0x%p to 0x%p\n",
2151 le32_to_cpu(newext->ee_block),
2152 ext4_ext_pblock(newext),
2153 ext4_ext_is_unwritten(newext),
2154 ext4_ext_get_actual_len(newext),
2155 len, nearex, nearex + 1);
2156 memmove(nearex + 1, nearex,
2157 len * sizeof(struct ext4_extent));
2158 }
2159 }
2160
2161 le16_add_cpu(&eh->eh_entries, 1);
2162 path[depth].p_ext = nearex;
2163 nearex->ee_block = newext->ee_block;
2164 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2165 nearex->ee_len = newext->ee_len;
2166
2167merge:
2168 /* try to merge extents */
2169 if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2170 ext4_ext_try_to_merge(handle, inode, path, nearex);
2171
2172
2173 /* time to correct all indexes above */
2174 err = ext4_ext_correct_indexes(handle, inode, path);
2175 if (err)
2176 goto cleanup;
2177
2178 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2179
2180cleanup:
2181 ext4_free_ext_path(npath);
2182 return err;
2183}
2184
2185static int ext4_fill_es_cache_info(struct inode *inode,
2186 ext4_lblk_t block, ext4_lblk_t num,
2187 struct fiemap_extent_info *fieinfo)
2188{
2189 ext4_lblk_t next, end = block + num - 1;
2190 struct extent_status es;
2191 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2192 unsigned int flags;
2193 int err;
2194
2195 while (block <= end) {
2196 next = 0;
2197 flags = 0;
2198 if (!ext4_es_lookup_extent(inode, block, &next, &es))
2199 break;
2200 if (ext4_es_is_unwritten(&es))
2201 flags |= FIEMAP_EXTENT_UNWRITTEN;
2202 if (ext4_es_is_delayed(&es))
2203 flags |= (FIEMAP_EXTENT_DELALLOC |
2204 FIEMAP_EXTENT_UNKNOWN);
2205 if (ext4_es_is_hole(&es))
2206 flags |= EXT4_FIEMAP_EXTENT_HOLE;
2207 if (next == 0)
2208 flags |= FIEMAP_EXTENT_LAST;
2209 if (flags & (FIEMAP_EXTENT_DELALLOC|
2210 EXT4_FIEMAP_EXTENT_HOLE))
2211 es.es_pblk = 0;
2212 else
2213 es.es_pblk = ext4_es_pblock(&es);
2214 err = fiemap_fill_next_extent(fieinfo,
2215 (__u64)es.es_lblk << blksize_bits,
2216 (__u64)es.es_pblk << blksize_bits,
2217 (__u64)es.es_len << blksize_bits,
2218 flags);
2219 if (next == 0)
2220 break;
2221 block = next;
2222 if (err < 0)
2223 return err;
2224 if (err == 1)
2225 return 0;
2226 }
2227 return 0;
2228}
2229
2230
2231/*
2232 * ext4_ext_find_hole - find hole around given block according to the given path
2233 * @inode: inode we lookup in
2234 * @path: path in extent tree to @lblk
2235 * @lblk: pointer to logical block around which we want to determine hole
2236 *
2237 * Determine hole length (and start if easily possible) around given logical
2238 * block. We don't try too hard to find the beginning of the hole but @path
2239 * actually points to extent before @lblk, we provide it.
2240 *
2241 * The function returns the length of a hole starting at @lblk. We update @lblk
2242 * to the beginning of the hole if we managed to find it.
2243 */
2244static ext4_lblk_t ext4_ext_find_hole(struct inode *inode,
2245 struct ext4_ext_path *path,
2246 ext4_lblk_t *lblk)
2247{
2248 int depth = ext_depth(inode);
2249 struct ext4_extent *ex;
2250 ext4_lblk_t len;
2251
2252 ex = path[depth].p_ext;
2253 if (ex == NULL) {
2254 /* there is no extent yet, so gap is [0;-] */
2255 *lblk = 0;
2256 len = EXT_MAX_BLOCKS;
2257 } else if (*lblk < le32_to_cpu(ex->ee_block)) {
2258 len = le32_to_cpu(ex->ee_block) - *lblk;
2259 } else if (*lblk >= le32_to_cpu(ex->ee_block)
2260 + ext4_ext_get_actual_len(ex)) {
2261 ext4_lblk_t next;
2262
2263 *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
2264 next = ext4_ext_next_allocated_block(path);
2265 BUG_ON(next == *lblk);
2266 len = next - *lblk;
2267 } else {
2268 BUG();
2269 }
2270 return len;
2271}
2272
2273/*
2274 * ext4_ext_rm_idx:
2275 * removes index from the index block.
2276 */
2277static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2278 struct ext4_ext_path *path, int depth)
2279{
2280 int err;
2281 ext4_fsblk_t leaf;
2282
2283 /* free index block */
2284 depth--;
2285 path = path + depth;
2286 leaf = ext4_idx_pblock(path->p_idx);
2287 if (unlikely(path->p_hdr->eh_entries == 0)) {
2288 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2289 return -EFSCORRUPTED;
2290 }
2291 err = ext4_ext_get_access(handle, inode, path);
2292 if (err)
2293 return err;
2294
2295 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2296 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2297 len *= sizeof(struct ext4_extent_idx);
2298 memmove(path->p_idx, path->p_idx + 1, len);
2299 }
2300
2301 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2302 err = ext4_ext_dirty(handle, inode, path);
2303 if (err)
2304 return err;
2305 ext_debug(inode, "index is empty, remove it, free block %llu\n", leaf);
2306 trace_ext4_ext_rm_idx(inode, leaf);
2307
2308 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2309 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2310
2311 while (--depth >= 0) {
2312 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2313 break;
2314 path--;
2315 err = ext4_ext_get_access(handle, inode, path);
2316 if (err)
2317 break;
2318 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2319 err = ext4_ext_dirty(handle, inode, path);
2320 if (err)
2321 break;
2322 }
2323 return err;
2324}
2325
2326/*
2327 * ext4_ext_calc_credits_for_single_extent:
2328 * This routine returns max. credits that needed to insert an extent
2329 * to the extent tree.
2330 * When pass the actual path, the caller should calculate credits
2331 * under i_data_sem.
2332 */
2333int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2334 struct ext4_ext_path *path)
2335{
2336 if (path) {
2337 int depth = ext_depth(inode);
2338 int ret = 0;
2339
2340 /* probably there is space in leaf? */
2341 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2342 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2343
2344 /*
2345 * There are some space in the leaf tree, no
2346 * need to account for leaf block credit
2347 *
2348 * bitmaps and block group descriptor blocks
2349 * and other metadata blocks still need to be
2350 * accounted.
2351 */
2352 /* 1 bitmap, 1 block group descriptor */
2353 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2354 return ret;
2355 }
2356 }
2357
2358 return ext4_chunk_trans_blocks(inode, nrblocks);
2359}
2360
2361/*
2362 * How many index/leaf blocks need to change/allocate to add @extents extents?
2363 *
2364 * If we add a single extent, then in the worse case, each tree level
2365 * index/leaf need to be changed in case of the tree split.
2366 *
2367 * If more extents are inserted, they could cause the whole tree split more
2368 * than once, but this is really rare.
2369 */
2370int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2371{
2372 int index;
2373 int depth;
2374
2375 /* If we are converting the inline data, only one is needed here. */
2376 if (ext4_has_inline_data(inode))
2377 return 1;
2378
2379 depth = ext_depth(inode);
2380
2381 if (extents <= 1)
2382 index = depth * 2;
2383 else
2384 index = depth * 3;
2385
2386 return index;
2387}
2388
2389static inline int get_default_free_blocks_flags(struct inode *inode)
2390{
2391 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) ||
2392 ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE))
2393 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2394 else if (ext4_should_journal_data(inode))
2395 return EXT4_FREE_BLOCKS_FORGET;
2396 return 0;
2397}
2398
2399/*
2400 * ext4_rereserve_cluster - increment the reserved cluster count when
2401 * freeing a cluster with a pending reservation
2402 *
2403 * @inode - file containing the cluster
2404 * @lblk - logical block in cluster to be reserved
2405 *
2406 * Increments the reserved cluster count and adjusts quota in a bigalloc
2407 * file system when freeing a partial cluster containing at least one
2408 * delayed and unwritten block. A partial cluster meeting that
2409 * requirement will have a pending reservation. If so, the
2410 * RERESERVE_CLUSTER flag is used when calling ext4_free_blocks() to
2411 * defer reserved and allocated space accounting to a subsequent call
2412 * to this function.
2413 */
2414static void ext4_rereserve_cluster(struct inode *inode, ext4_lblk_t lblk)
2415{
2416 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2417 struct ext4_inode_info *ei = EXT4_I(inode);
2418
2419 dquot_reclaim_block(inode, EXT4_C2B(sbi, 1));
2420
2421 spin_lock(&ei->i_block_reservation_lock);
2422 ei->i_reserved_data_blocks++;
2423 percpu_counter_add(&sbi->s_dirtyclusters_counter, 1);
2424 spin_unlock(&ei->i_block_reservation_lock);
2425
2426 percpu_counter_add(&sbi->s_freeclusters_counter, 1);
2427 ext4_remove_pending(inode, lblk);
2428}
2429
2430static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2431 struct ext4_extent *ex,
2432 struct partial_cluster *partial,
2433 ext4_lblk_t from, ext4_lblk_t to)
2434{
2435 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2436 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2437 ext4_fsblk_t last_pblk, pblk;
2438 ext4_lblk_t num;
2439 int flags;
2440
2441 /* only extent tail removal is allowed */
2442 if (from < le32_to_cpu(ex->ee_block) ||
2443 to != le32_to_cpu(ex->ee_block) + ee_len - 1) {
2444 ext4_error(sbi->s_sb,
2445 "strange request: removal(2) %u-%u from %u:%u",
2446 from, to, le32_to_cpu(ex->ee_block), ee_len);
2447 return 0;
2448 }
2449
2450#ifdef EXTENTS_STATS
2451 spin_lock(&sbi->s_ext_stats_lock);
2452 sbi->s_ext_blocks += ee_len;
2453 sbi->s_ext_extents++;
2454 if (ee_len < sbi->s_ext_min)
2455 sbi->s_ext_min = ee_len;
2456 if (ee_len > sbi->s_ext_max)
2457 sbi->s_ext_max = ee_len;
2458 if (ext_depth(inode) > sbi->s_depth_max)
2459 sbi->s_depth_max = ext_depth(inode);
2460 spin_unlock(&sbi->s_ext_stats_lock);
2461#endif
2462
2463 trace_ext4_remove_blocks(inode, ex, from, to, partial);
2464
2465 /*
2466 * if we have a partial cluster, and it's different from the
2467 * cluster of the last block in the extent, we free it
2468 */
2469 last_pblk = ext4_ext_pblock(ex) + ee_len - 1;
2470
2471 if (partial->state != initial &&
2472 partial->pclu != EXT4_B2C(sbi, last_pblk)) {
2473 if (partial->state == tofree) {
2474 flags = get_default_free_blocks_flags(inode);
2475 if (ext4_is_pending(inode, partial->lblk))
2476 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2477 ext4_free_blocks(handle, inode, NULL,
2478 EXT4_C2B(sbi, partial->pclu),
2479 sbi->s_cluster_ratio, flags);
2480 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2481 ext4_rereserve_cluster(inode, partial->lblk);
2482 }
2483 partial->state = initial;
2484 }
2485
2486 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2487 pblk = ext4_ext_pblock(ex) + ee_len - num;
2488
2489 /*
2490 * We free the partial cluster at the end of the extent (if any),
2491 * unless the cluster is used by another extent (partial_cluster
2492 * state is nofree). If a partial cluster exists here, it must be
2493 * shared with the last block in the extent.
2494 */
2495 flags = get_default_free_blocks_flags(inode);
2496
2497 /* partial, left end cluster aligned, right end unaligned */
2498 if ((EXT4_LBLK_COFF(sbi, to) != sbi->s_cluster_ratio - 1) &&
2499 (EXT4_LBLK_CMASK(sbi, to) >= from) &&
2500 (partial->state != nofree)) {
2501 if (ext4_is_pending(inode, to))
2502 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2503 ext4_free_blocks(handle, inode, NULL,
2504 EXT4_PBLK_CMASK(sbi, last_pblk),
2505 sbi->s_cluster_ratio, flags);
2506 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2507 ext4_rereserve_cluster(inode, to);
2508 partial->state = initial;
2509 flags = get_default_free_blocks_flags(inode);
2510 }
2511
2512 flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2513
2514 /*
2515 * For bigalloc file systems, we never free a partial cluster
2516 * at the beginning of the extent. Instead, we check to see if we
2517 * need to free it on a subsequent call to ext4_remove_blocks,
2518 * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
2519 */
2520 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2521 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2522
2523 /* reset the partial cluster if we've freed past it */
2524 if (partial->state != initial && partial->pclu != EXT4_B2C(sbi, pblk))
2525 partial->state = initial;
2526
2527 /*
2528 * If we've freed the entire extent but the beginning is not left
2529 * cluster aligned and is not marked as ineligible for freeing we
2530 * record the partial cluster at the beginning of the extent. It
2531 * wasn't freed by the preceding ext4_free_blocks() call, and we
2532 * need to look farther to the left to determine if it's to be freed
2533 * (not shared with another extent). Else, reset the partial
2534 * cluster - we're either done freeing or the beginning of the
2535 * extent is left cluster aligned.
2536 */
2537 if (EXT4_LBLK_COFF(sbi, from) && num == ee_len) {
2538 if (partial->state == initial) {
2539 partial->pclu = EXT4_B2C(sbi, pblk);
2540 partial->lblk = from;
2541 partial->state = tofree;
2542 }
2543 } else {
2544 partial->state = initial;
2545 }
2546
2547 return 0;
2548}
2549
2550/*
2551 * ext4_ext_rm_leaf() Removes the extents associated with the
2552 * blocks appearing between "start" and "end". Both "start"
2553 * and "end" must appear in the same extent or EIO is returned.
2554 *
2555 * @handle: The journal handle
2556 * @inode: The files inode
2557 * @path: The path to the leaf
2558 * @partial_cluster: The cluster which we'll have to free if all extents
2559 * has been released from it. However, if this value is
2560 * negative, it's a cluster just to the right of the
2561 * punched region and it must not be freed.
2562 * @start: The first block to remove
2563 * @end: The last block to remove
2564 */
2565static int
2566ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2567 struct ext4_ext_path *path,
2568 struct partial_cluster *partial,
2569 ext4_lblk_t start, ext4_lblk_t end)
2570{
2571 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2572 int err = 0, correct_index = 0;
2573 int depth = ext_depth(inode), credits, revoke_credits;
2574 struct ext4_extent_header *eh;
2575 ext4_lblk_t a, b;
2576 unsigned num;
2577 ext4_lblk_t ex_ee_block;
2578 unsigned short ex_ee_len;
2579 unsigned unwritten = 0;
2580 struct ext4_extent *ex;
2581 ext4_fsblk_t pblk;
2582
2583 /* the header must be checked already in ext4_ext_remove_space() */
2584 ext_debug(inode, "truncate since %u in leaf to %u\n", start, end);
2585 if (!path[depth].p_hdr)
2586 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2587 eh = path[depth].p_hdr;
2588 if (unlikely(path[depth].p_hdr == NULL)) {
2589 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2590 return -EFSCORRUPTED;
2591 }
2592 /* find where to start removing */
2593 ex = path[depth].p_ext;
2594 if (!ex)
2595 ex = EXT_LAST_EXTENT(eh);
2596
2597 ex_ee_block = le32_to_cpu(ex->ee_block);
2598 ex_ee_len = ext4_ext_get_actual_len(ex);
2599
2600 trace_ext4_ext_rm_leaf(inode, start, ex, partial);
2601
2602 while (ex >= EXT_FIRST_EXTENT(eh) &&
2603 ex_ee_block + ex_ee_len > start) {
2604
2605 if (ext4_ext_is_unwritten(ex))
2606 unwritten = 1;
2607 else
2608 unwritten = 0;
2609
2610 ext_debug(inode, "remove ext %u:[%d]%d\n", ex_ee_block,
2611 unwritten, ex_ee_len);
2612 path[depth].p_ext = ex;
2613
2614 a = max(ex_ee_block, start);
2615 b = min(ex_ee_block + ex_ee_len - 1, end);
2616
2617 ext_debug(inode, " border %u:%u\n", a, b);
2618
2619 /* If this extent is beyond the end of the hole, skip it */
2620 if (end < ex_ee_block) {
2621 /*
2622 * We're going to skip this extent and move to another,
2623 * so note that its first cluster is in use to avoid
2624 * freeing it when removing blocks. Eventually, the
2625 * right edge of the truncated/punched region will
2626 * be just to the left.
2627 */
2628 if (sbi->s_cluster_ratio > 1) {
2629 pblk = ext4_ext_pblock(ex);
2630 partial->pclu = EXT4_B2C(sbi, pblk);
2631 partial->state = nofree;
2632 }
2633 ex--;
2634 ex_ee_block = le32_to_cpu(ex->ee_block);
2635 ex_ee_len = ext4_ext_get_actual_len(ex);
2636 continue;
2637 } else if (b != ex_ee_block + ex_ee_len - 1) {
2638 EXT4_ERROR_INODE(inode,
2639 "can not handle truncate %u:%u "
2640 "on extent %u:%u",
2641 start, end, ex_ee_block,
2642 ex_ee_block + ex_ee_len - 1);
2643 err = -EFSCORRUPTED;
2644 goto out;
2645 } else if (a != ex_ee_block) {
2646 /* remove tail of the extent */
2647 num = a - ex_ee_block;
2648 } else {
2649 /* remove whole extent: excellent! */
2650 num = 0;
2651 }
2652 /*
2653 * 3 for leaf, sb, and inode plus 2 (bmap and group
2654 * descriptor) for each block group; assume two block
2655 * groups plus ex_ee_len/blocks_per_block_group for
2656 * the worst case
2657 */
2658 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2659 if (ex == EXT_FIRST_EXTENT(eh)) {
2660 correct_index = 1;
2661 credits += (ext_depth(inode)) + 1;
2662 }
2663 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2664 /*
2665 * We may end up freeing some index blocks and data from the
2666 * punched range. Note that partial clusters are accounted for
2667 * by ext4_free_data_revoke_credits().
2668 */
2669 revoke_credits =
2670 ext4_free_metadata_revoke_credits(inode->i_sb,
2671 ext_depth(inode)) +
2672 ext4_free_data_revoke_credits(inode, b - a + 1);
2673
2674 err = ext4_datasem_ensure_credits(handle, inode, credits,
2675 credits, revoke_credits);
2676 if (err) {
2677 if (err > 0)
2678 err = -EAGAIN;
2679 goto out;
2680 }
2681
2682 err = ext4_ext_get_access(handle, inode, path + depth);
2683 if (err)
2684 goto out;
2685
2686 err = ext4_remove_blocks(handle, inode, ex, partial, a, b);
2687 if (err)
2688 goto out;
2689
2690 if (num == 0)
2691 /* this extent is removed; mark slot entirely unused */
2692 ext4_ext_store_pblock(ex, 0);
2693
2694 ex->ee_len = cpu_to_le16(num);
2695 /*
2696 * Do not mark unwritten if all the blocks in the
2697 * extent have been removed.
2698 */
2699 if (unwritten && num)
2700 ext4_ext_mark_unwritten(ex);
2701 /*
2702 * If the extent was completely released,
2703 * we need to remove it from the leaf
2704 */
2705 if (num == 0) {
2706 if (end != EXT_MAX_BLOCKS - 1) {
2707 /*
2708 * For hole punching, we need to scoot all the
2709 * extents up when an extent is removed so that
2710 * we dont have blank extents in the middle
2711 */
2712 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2713 sizeof(struct ext4_extent));
2714
2715 /* Now get rid of the one at the end */
2716 memset(EXT_LAST_EXTENT(eh), 0,
2717 sizeof(struct ext4_extent));
2718 }
2719 le16_add_cpu(&eh->eh_entries, -1);
2720 }
2721
2722 err = ext4_ext_dirty(handle, inode, path + depth);
2723 if (err)
2724 goto out;
2725
2726 ext_debug(inode, "new extent: %u:%u:%llu\n", ex_ee_block, num,
2727 ext4_ext_pblock(ex));
2728 ex--;
2729 ex_ee_block = le32_to_cpu(ex->ee_block);
2730 ex_ee_len = ext4_ext_get_actual_len(ex);
2731 }
2732
2733 if (correct_index && eh->eh_entries)
2734 err = ext4_ext_correct_indexes(handle, inode, path);
2735
2736 /*
2737 * If there's a partial cluster and at least one extent remains in
2738 * the leaf, free the partial cluster if it isn't shared with the
2739 * current extent. If it is shared with the current extent
2740 * we reset the partial cluster because we've reached the start of the
2741 * truncated/punched region and we're done removing blocks.
2742 */
2743 if (partial->state == tofree && ex >= EXT_FIRST_EXTENT(eh)) {
2744 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
2745 if (partial->pclu != EXT4_B2C(sbi, pblk)) {
2746 int flags = get_default_free_blocks_flags(inode);
2747
2748 if (ext4_is_pending(inode, partial->lblk))
2749 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2750 ext4_free_blocks(handle, inode, NULL,
2751 EXT4_C2B(sbi, partial->pclu),
2752 sbi->s_cluster_ratio, flags);
2753 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2754 ext4_rereserve_cluster(inode, partial->lblk);
2755 }
2756 partial->state = initial;
2757 }
2758
2759 /* if this leaf is free, then we should
2760 * remove it from index block above */
2761 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2762 err = ext4_ext_rm_idx(handle, inode, path, depth);
2763
2764out:
2765 return err;
2766}
2767
2768/*
2769 * ext4_ext_more_to_rm:
2770 * returns 1 if current index has to be freed (even partial)
2771 */
2772static int
2773ext4_ext_more_to_rm(struct ext4_ext_path *path)
2774{
2775 BUG_ON(path->p_idx == NULL);
2776
2777 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2778 return 0;
2779
2780 /*
2781 * if truncate on deeper level happened, it wasn't partial,
2782 * so we have to consider current index for truncation
2783 */
2784 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2785 return 0;
2786 return 1;
2787}
2788
2789int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2790 ext4_lblk_t end)
2791{
2792 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2793 int depth = ext_depth(inode);
2794 struct ext4_ext_path *path = NULL;
2795 struct partial_cluster partial;
2796 handle_t *handle;
2797 int i = 0, err = 0;
2798
2799 partial.pclu = 0;
2800 partial.lblk = 0;
2801 partial.state = initial;
2802
2803 ext_debug(inode, "truncate since %u to %u\n", start, end);
2804
2805 /* probably first extent we're gonna free will be last in block */
2806 handle = ext4_journal_start_with_revoke(inode, EXT4_HT_TRUNCATE,
2807 depth + 1,
2808 ext4_free_metadata_revoke_credits(inode->i_sb, depth));
2809 if (IS_ERR(handle))
2810 return PTR_ERR(handle);
2811
2812again:
2813 trace_ext4_ext_remove_space(inode, start, end, depth);
2814
2815 /*
2816 * Check if we are removing extents inside the extent tree. If that
2817 * is the case, we are going to punch a hole inside the extent tree
2818 * so we have to check whether we need to split the extent covering
2819 * the last block to remove so we can easily remove the part of it
2820 * in ext4_ext_rm_leaf().
2821 */
2822 if (end < EXT_MAX_BLOCKS - 1) {
2823 struct ext4_extent *ex;
2824 ext4_lblk_t ee_block, ex_end, lblk;
2825 ext4_fsblk_t pblk;
2826
2827 /* find extent for or closest extent to this block */
2828 path = ext4_find_extent(inode, end, NULL,
2829 EXT4_EX_NOCACHE | EXT4_EX_NOFAIL);
2830 if (IS_ERR(path)) {
2831 ext4_journal_stop(handle);
2832 return PTR_ERR(path);
2833 }
2834 depth = ext_depth(inode);
2835 /* Leaf not may not exist only if inode has no blocks at all */
2836 ex = path[depth].p_ext;
2837 if (!ex) {
2838 if (depth) {
2839 EXT4_ERROR_INODE(inode,
2840 "path[%d].p_hdr == NULL",
2841 depth);
2842 err = -EFSCORRUPTED;
2843 }
2844 goto out;
2845 }
2846
2847 ee_block = le32_to_cpu(ex->ee_block);
2848 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
2849
2850 /*
2851 * See if the last block is inside the extent, if so split
2852 * the extent at 'end' block so we can easily remove the
2853 * tail of the first part of the split extent in
2854 * ext4_ext_rm_leaf().
2855 */
2856 if (end >= ee_block && end < ex_end) {
2857
2858 /*
2859 * If we're going to split the extent, note that
2860 * the cluster containing the block after 'end' is
2861 * in use to avoid freeing it when removing blocks.
2862 */
2863 if (sbi->s_cluster_ratio > 1) {
2864 pblk = ext4_ext_pblock(ex) + end - ee_block + 1;
2865 partial.pclu = EXT4_B2C(sbi, pblk);
2866 partial.state = nofree;
2867 }
2868
2869 /*
2870 * Split the extent in two so that 'end' is the last
2871 * block in the first new extent. Also we should not
2872 * fail removing space due to ENOSPC so try to use
2873 * reserved block if that happens.
2874 */
2875 err = ext4_force_split_extent_at(handle, inode, &path,
2876 end + 1, 1);
2877 if (err < 0)
2878 goto out;
2879
2880 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end &&
2881 partial.state == initial) {
2882 /*
2883 * If we're punching, there's an extent to the right.
2884 * If the partial cluster hasn't been set, set it to
2885 * that extent's first cluster and its state to nofree
2886 * so it won't be freed should it contain blocks to be
2887 * removed. If it's already set (tofree/nofree), we're
2888 * retrying and keep the original partial cluster info
2889 * so a cluster marked tofree as a result of earlier
2890 * extent removal is not lost.
2891 */
2892 lblk = ex_end + 1;
2893 err = ext4_ext_search_right(inode, path, &lblk, &pblk,
2894 NULL);
2895 if (err < 0)
2896 goto out;
2897 if (pblk) {
2898 partial.pclu = EXT4_B2C(sbi, pblk);
2899 partial.state = nofree;
2900 }
2901 }
2902 }
2903 /*
2904 * We start scanning from right side, freeing all the blocks
2905 * after i_size and walking into the tree depth-wise.
2906 */
2907 depth = ext_depth(inode);
2908 if (path) {
2909 int k = i = depth;
2910 while (--k > 0)
2911 path[k].p_block =
2912 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2913 } else {
2914 path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
2915 GFP_NOFS | __GFP_NOFAIL);
2916 if (path == NULL) {
2917 ext4_journal_stop(handle);
2918 return -ENOMEM;
2919 }
2920 path[0].p_maxdepth = path[0].p_depth = depth;
2921 path[0].p_hdr = ext_inode_hdr(inode);
2922 i = 0;
2923
2924 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2925 err = -EFSCORRUPTED;
2926 goto out;
2927 }
2928 }
2929 err = 0;
2930
2931 while (i >= 0 && err == 0) {
2932 if (i == depth) {
2933 /* this is leaf block */
2934 err = ext4_ext_rm_leaf(handle, inode, path,
2935 &partial, start, end);
2936 /* root level has p_bh == NULL, brelse() eats this */
2937 brelse(path[i].p_bh);
2938 path[i].p_bh = NULL;
2939 i--;
2940 continue;
2941 }
2942
2943 /* this is index block */
2944 if (!path[i].p_hdr) {
2945 ext_debug(inode, "initialize header\n");
2946 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2947 }
2948
2949 if (!path[i].p_idx) {
2950 /* this level hasn't been touched yet */
2951 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2952 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2953 ext_debug(inode, "init index ptr: hdr 0x%p, num %d\n",
2954 path[i].p_hdr,
2955 le16_to_cpu(path[i].p_hdr->eh_entries));
2956 } else {
2957 /* we were already here, see at next index */
2958 path[i].p_idx--;
2959 }
2960
2961 ext_debug(inode, "level %d - index, first 0x%p, cur 0x%p\n",
2962 i, EXT_FIRST_INDEX(path[i].p_hdr),
2963 path[i].p_idx);
2964 if (ext4_ext_more_to_rm(path + i)) {
2965 struct buffer_head *bh;
2966 /* go to the next level */
2967 ext_debug(inode, "move to level %d (block %llu)\n",
2968 i + 1, ext4_idx_pblock(path[i].p_idx));
2969 memset(path + i + 1, 0, sizeof(*path));
2970 bh = read_extent_tree_block(inode, path[i].p_idx,
2971 depth - i - 1,
2972 EXT4_EX_NOCACHE);
2973 if (IS_ERR(bh)) {
2974 /* should we reset i_size? */
2975 err = PTR_ERR(bh);
2976 break;
2977 }
2978 /* Yield here to deal with large extent trees.
2979 * Should be a no-op if we did IO above. */
2980 cond_resched();
2981 if (WARN_ON(i + 1 > depth)) {
2982 err = -EFSCORRUPTED;
2983 break;
2984 }
2985 path[i + 1].p_bh = bh;
2986
2987 /* save actual number of indexes since this
2988 * number is changed at the next iteration */
2989 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2990 i++;
2991 } else {
2992 /* we finished processing this index, go up */
2993 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2994 /* index is empty, remove it;
2995 * handle must be already prepared by the
2996 * truncatei_leaf() */
2997 err = ext4_ext_rm_idx(handle, inode, path, i);
2998 }
2999 /* root level has p_bh == NULL, brelse() eats this */
3000 brelse(path[i].p_bh);
3001 path[i].p_bh = NULL;
3002 i--;
3003 ext_debug(inode, "return to level %d\n", i);
3004 }
3005 }
3006
3007 trace_ext4_ext_remove_space_done(inode, start, end, depth, &partial,
3008 path->p_hdr->eh_entries);
3009
3010 /*
3011 * if there's a partial cluster and we have removed the first extent
3012 * in the file, then we also free the partial cluster, if any
3013 */
3014 if (partial.state == tofree && err == 0) {
3015 int flags = get_default_free_blocks_flags(inode);
3016
3017 if (ext4_is_pending(inode, partial.lblk))
3018 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
3019 ext4_free_blocks(handle, inode, NULL,
3020 EXT4_C2B(sbi, partial.pclu),
3021 sbi->s_cluster_ratio, flags);
3022 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
3023 ext4_rereserve_cluster(inode, partial.lblk);
3024 partial.state = initial;
3025 }
3026
3027 /* TODO: flexible tree reduction should be here */
3028 if (path->p_hdr->eh_entries == 0) {
3029 /*
3030 * truncate to zero freed all the tree,
3031 * so we need to correct eh_depth
3032 */
3033 err = ext4_ext_get_access(handle, inode, path);
3034 if (err == 0) {
3035 ext_inode_hdr(inode)->eh_depth = 0;
3036 ext_inode_hdr(inode)->eh_max =
3037 cpu_to_le16(ext4_ext_space_root(inode, 0));
3038 err = ext4_ext_dirty(handle, inode, path);
3039 }
3040 }
3041out:
3042 ext4_free_ext_path(path);
3043 path = NULL;
3044 if (err == -EAGAIN)
3045 goto again;
3046 ext4_journal_stop(handle);
3047
3048 return err;
3049}
3050
3051/*
3052 * called at mount time
3053 */
3054void ext4_ext_init(struct super_block *sb)
3055{
3056 /*
3057 * possible initialization would be here
3058 */
3059
3060 if (ext4_has_feature_extents(sb)) {
3061#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
3062 printk(KERN_INFO "EXT4-fs: file extents enabled"
3063#ifdef AGGRESSIVE_TEST
3064 ", aggressive tests"
3065#endif
3066#ifdef CHECK_BINSEARCH
3067 ", check binsearch"
3068#endif
3069#ifdef EXTENTS_STATS
3070 ", stats"
3071#endif
3072 "\n");
3073#endif
3074#ifdef EXTENTS_STATS
3075 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3076 EXT4_SB(sb)->s_ext_min = 1 << 30;
3077 EXT4_SB(sb)->s_ext_max = 0;
3078#endif
3079 }
3080}
3081
3082/*
3083 * called at umount time
3084 */
3085void ext4_ext_release(struct super_block *sb)
3086{
3087 if (!ext4_has_feature_extents(sb))
3088 return;
3089
3090#ifdef EXTENTS_STATS
3091 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3092 struct ext4_sb_info *sbi = EXT4_SB(sb);
3093 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3094 sbi->s_ext_blocks, sbi->s_ext_extents,
3095 sbi->s_ext_blocks / sbi->s_ext_extents);
3096 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3097 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3098 }
3099#endif
3100}
3101
3102static void ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3103{
3104 ext4_lblk_t ee_block;
3105 ext4_fsblk_t ee_pblock;
3106 unsigned int ee_len;
3107
3108 ee_block = le32_to_cpu(ex->ee_block);
3109 ee_len = ext4_ext_get_actual_len(ex);
3110 ee_pblock = ext4_ext_pblock(ex);
3111
3112 if (ee_len == 0)
3113 return;
3114
3115 ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3116 EXTENT_STATUS_WRITTEN);
3117}
3118
3119/* FIXME!! we need to try to merge to left or right after zero-out */
3120static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3121{
3122 ext4_fsblk_t ee_pblock;
3123 unsigned int ee_len;
3124
3125 ee_len = ext4_ext_get_actual_len(ex);
3126 ee_pblock = ext4_ext_pblock(ex);
3127 return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock,
3128 ee_len);
3129}
3130
3131/*
3132 * ext4_split_extent_at() splits an extent at given block.
3133 *
3134 * @handle: the journal handle
3135 * @inode: the file inode
3136 * @path: the path to the extent
3137 * @split: the logical block where the extent is splitted.
3138 * @split_flags: indicates if the extent could be zeroout if split fails, and
3139 * the states(init or unwritten) of new extents.
3140 * @flags: flags used to insert new extent to extent tree.
3141 *
3142 *
3143 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3144 * of which are determined by split_flag.
3145 *
3146 * There are two cases:
3147 * a> the extent are splitted into two extent.
3148 * b> split is not needed, and just mark the extent.
3149 *
3150 * return 0 on success.
3151 */
3152static int ext4_split_extent_at(handle_t *handle,
3153 struct inode *inode,
3154 struct ext4_ext_path **ppath,
3155 ext4_lblk_t split,
3156 int split_flag,
3157 int flags)
3158{
3159 struct ext4_ext_path *path = *ppath;
3160 ext4_fsblk_t newblock;
3161 ext4_lblk_t ee_block;
3162 struct ext4_extent *ex, newex, orig_ex, zero_ex;
3163 struct ext4_extent *ex2 = NULL;
3164 unsigned int ee_len, depth;
3165 int err = 0;
3166
3167 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3168 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3169
3170 ext_debug(inode, "logical block %llu\n", (unsigned long long)split);
3171
3172 ext4_ext_show_leaf(inode, path);
3173
3174 depth = ext_depth(inode);
3175 ex = path[depth].p_ext;
3176 ee_block = le32_to_cpu(ex->ee_block);
3177 ee_len = ext4_ext_get_actual_len(ex);
3178 newblock = split - ee_block + ext4_ext_pblock(ex);
3179
3180 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3181 BUG_ON(!ext4_ext_is_unwritten(ex) &&
3182 split_flag & (EXT4_EXT_MAY_ZEROOUT |
3183 EXT4_EXT_MARK_UNWRIT1 |
3184 EXT4_EXT_MARK_UNWRIT2));
3185
3186 err = ext4_ext_get_access(handle, inode, path + depth);
3187 if (err)
3188 goto out;
3189
3190 if (split == ee_block) {
3191 /*
3192 * case b: block @split is the block that the extent begins with
3193 * then we just change the state of the extent, and splitting
3194 * is not needed.
3195 */
3196 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3197 ext4_ext_mark_unwritten(ex);
3198 else
3199 ext4_ext_mark_initialized(ex);
3200
3201 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3202 ext4_ext_try_to_merge(handle, inode, path, ex);
3203
3204 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3205 goto out;
3206 }
3207
3208 /* case a */
3209 memcpy(&orig_ex, ex, sizeof(orig_ex));
3210 ex->ee_len = cpu_to_le16(split - ee_block);
3211 if (split_flag & EXT4_EXT_MARK_UNWRIT1)
3212 ext4_ext_mark_unwritten(ex);
3213
3214 /*
3215 * path may lead to new leaf, not to original leaf any more
3216 * after ext4_ext_insert_extent() returns,
3217 */
3218 err = ext4_ext_dirty(handle, inode, path + depth);
3219 if (err)
3220 goto fix_extent_len;
3221
3222 ex2 = &newex;
3223 ex2->ee_block = cpu_to_le32(split);
3224 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
3225 ext4_ext_store_pblock(ex2, newblock);
3226 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3227 ext4_ext_mark_unwritten(ex2);
3228
3229 err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
3230 if (err != -ENOSPC && err != -EDQUOT && err != -ENOMEM)
3231 goto out;
3232
3233 if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
3234 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3235 if (split_flag & EXT4_EXT_DATA_VALID1) {
3236 err = ext4_ext_zeroout(inode, ex2);
3237 zero_ex.ee_block = ex2->ee_block;
3238 zero_ex.ee_len = cpu_to_le16(
3239 ext4_ext_get_actual_len(ex2));
3240 ext4_ext_store_pblock(&zero_ex,
3241 ext4_ext_pblock(ex2));
3242 } else {
3243 err = ext4_ext_zeroout(inode, ex);
3244 zero_ex.ee_block = ex->ee_block;
3245 zero_ex.ee_len = cpu_to_le16(
3246 ext4_ext_get_actual_len(ex));
3247 ext4_ext_store_pblock(&zero_ex,
3248 ext4_ext_pblock(ex));
3249 }
3250 } else {
3251 err = ext4_ext_zeroout(inode, &orig_ex);
3252 zero_ex.ee_block = orig_ex.ee_block;
3253 zero_ex.ee_len = cpu_to_le16(
3254 ext4_ext_get_actual_len(&orig_ex));
3255 ext4_ext_store_pblock(&zero_ex,
3256 ext4_ext_pblock(&orig_ex));
3257 }
3258
3259 if (!err) {
3260 /* update the extent length and mark as initialized */
3261 ex->ee_len = cpu_to_le16(ee_len);
3262 ext4_ext_try_to_merge(handle, inode, path, ex);
3263 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3264 if (!err)
3265 /* update extent status tree */
3266 ext4_zeroout_es(inode, &zero_ex);
3267 /* If we failed at this point, we don't know in which
3268 * state the extent tree exactly is so don't try to fix
3269 * length of the original extent as it may do even more
3270 * damage.
3271 */
3272 goto out;
3273 }
3274 }
3275
3276fix_extent_len:
3277 ex->ee_len = orig_ex.ee_len;
3278 /*
3279 * Ignore ext4_ext_dirty return value since we are already in error path
3280 * and err is a non-zero error code.
3281 */
3282 ext4_ext_dirty(handle, inode, path + path->p_depth);
3283 return err;
3284out:
3285 ext4_ext_show_leaf(inode, path);
3286 return err;
3287}
3288
3289/*
3290 * ext4_split_extents() splits an extent and mark extent which is covered
3291 * by @map as split_flags indicates
3292 *
3293 * It may result in splitting the extent into multiple extents (up to three)
3294 * There are three possibilities:
3295 * a> There is no split required
3296 * b> Splits in two extents: Split is happening at either end of the extent
3297 * c> Splits in three extents: Somone is splitting in middle of the extent
3298 *
3299 */
3300static int ext4_split_extent(handle_t *handle,
3301 struct inode *inode,
3302 struct ext4_ext_path **ppath,
3303 struct ext4_map_blocks *map,
3304 int split_flag,
3305 int flags)
3306{
3307 struct ext4_ext_path *path = *ppath;
3308 ext4_lblk_t ee_block;
3309 struct ext4_extent *ex;
3310 unsigned int ee_len, depth;
3311 int err = 0;
3312 int unwritten;
3313 int split_flag1, flags1;
3314 int allocated = map->m_len;
3315
3316 depth = ext_depth(inode);
3317 ex = path[depth].p_ext;
3318 ee_block = le32_to_cpu(ex->ee_block);
3319 ee_len = ext4_ext_get_actual_len(ex);
3320 unwritten = ext4_ext_is_unwritten(ex);
3321
3322 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3323 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3324 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3325 if (unwritten)
3326 split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
3327 EXT4_EXT_MARK_UNWRIT2;
3328 if (split_flag & EXT4_EXT_DATA_VALID2)
3329 split_flag1 |= EXT4_EXT_DATA_VALID1;
3330 err = ext4_split_extent_at(handle, inode, ppath,
3331 map->m_lblk + map->m_len, split_flag1, flags1);
3332 if (err)
3333 goto out;
3334 } else {
3335 allocated = ee_len - (map->m_lblk - ee_block);
3336 }
3337 /*
3338 * Update path is required because previous ext4_split_extent_at() may
3339 * result in split of original leaf or extent zeroout.
3340 */
3341 path = ext4_find_extent(inode, map->m_lblk, ppath, flags);
3342 if (IS_ERR(path))
3343 return PTR_ERR(path);
3344 depth = ext_depth(inode);
3345 ex = path[depth].p_ext;
3346 if (!ex) {
3347 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3348 (unsigned long) map->m_lblk);
3349 return -EFSCORRUPTED;
3350 }
3351 unwritten = ext4_ext_is_unwritten(ex);
3352
3353 if (map->m_lblk >= ee_block) {
3354 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3355 if (unwritten) {
3356 split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
3357 split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3358 EXT4_EXT_MARK_UNWRIT2);
3359 }
3360 err = ext4_split_extent_at(handle, inode, ppath,
3361 map->m_lblk, split_flag1, flags);
3362 if (err)
3363 goto out;
3364 }
3365
3366 ext4_ext_show_leaf(inode, path);
3367out:
3368 return err ? err : allocated;
3369}
3370
3371/*
3372 * This function is called by ext4_ext_map_blocks() if someone tries to write
3373 * to an unwritten extent. It may result in splitting the unwritten
3374 * extent into multiple extents (up to three - one initialized and two
3375 * unwritten).
3376 * There are three possibilities:
3377 * a> There is no split required: Entire extent should be initialized
3378 * b> Splits in two extents: Write is happening at either end of the extent
3379 * c> Splits in three extents: Somone is writing in middle of the extent
3380 *
3381 * Pre-conditions:
3382 * - The extent pointed to by 'path' is unwritten.
3383 * - The extent pointed to by 'path' contains a superset
3384 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3385 *
3386 * Post-conditions on success:
3387 * - the returned value is the number of blocks beyond map->l_lblk
3388 * that are allocated and initialized.
3389 * It is guaranteed to be >= map->m_len.
3390 */
3391static int ext4_ext_convert_to_initialized(handle_t *handle,
3392 struct inode *inode,
3393 struct ext4_map_blocks *map,
3394 struct ext4_ext_path **ppath,
3395 int flags)
3396{
3397 struct ext4_ext_path *path = *ppath;
3398 struct ext4_sb_info *sbi;
3399 struct ext4_extent_header *eh;
3400 struct ext4_map_blocks split_map;
3401 struct ext4_extent zero_ex1, zero_ex2;
3402 struct ext4_extent *ex, *abut_ex;
3403 ext4_lblk_t ee_block, eof_block;
3404 unsigned int ee_len, depth, map_len = map->m_len;
3405 int allocated = 0, max_zeroout = 0;
3406 int err = 0;
3407 int split_flag = EXT4_EXT_DATA_VALID2;
3408
3409 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3410 (unsigned long long)map->m_lblk, map_len);
3411
3412 sbi = EXT4_SB(inode->i_sb);
3413 eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1)
3414 >> inode->i_sb->s_blocksize_bits;
3415 if (eof_block < map->m_lblk + map_len)
3416 eof_block = map->m_lblk + map_len;
3417
3418 depth = ext_depth(inode);
3419 eh = path[depth].p_hdr;
3420 ex = path[depth].p_ext;
3421 ee_block = le32_to_cpu(ex->ee_block);
3422 ee_len = ext4_ext_get_actual_len(ex);
3423 zero_ex1.ee_len = 0;
3424 zero_ex2.ee_len = 0;
3425
3426 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3427
3428 /* Pre-conditions */
3429 BUG_ON(!ext4_ext_is_unwritten(ex));
3430 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3431
3432 /*
3433 * Attempt to transfer newly initialized blocks from the currently
3434 * unwritten extent to its neighbor. This is much cheaper
3435 * than an insertion followed by a merge as those involve costly
3436 * memmove() calls. Transferring to the left is the common case in
3437 * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3438 * followed by append writes.
3439 *
3440 * Limitations of the current logic:
3441 * - L1: we do not deal with writes covering the whole extent.
3442 * This would require removing the extent if the transfer
3443 * is possible.
3444 * - L2: we only attempt to merge with an extent stored in the
3445 * same extent tree node.
3446 */
3447 if ((map->m_lblk == ee_block) &&
3448 /* See if we can merge left */
3449 (map_len < ee_len) && /*L1*/
3450 (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/
3451 ext4_lblk_t prev_lblk;
3452 ext4_fsblk_t prev_pblk, ee_pblk;
3453 unsigned int prev_len;
3454
3455 abut_ex = ex - 1;
3456 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3457 prev_len = ext4_ext_get_actual_len(abut_ex);
3458 prev_pblk = ext4_ext_pblock(abut_ex);
3459 ee_pblk = ext4_ext_pblock(ex);
3460
3461 /*
3462 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3463 * upon those conditions:
3464 * - C1: abut_ex is initialized,
3465 * - C2: abut_ex is logically abutting ex,
3466 * - C3: abut_ex is physically abutting ex,
3467 * - C4: abut_ex can receive the additional blocks without
3468 * overflowing the (initialized) length limit.
3469 */
3470 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3471 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3472 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3473 (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3474 err = ext4_ext_get_access(handle, inode, path + depth);
3475 if (err)
3476 goto out;
3477
3478 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3479 map, ex, abut_ex);
3480
3481 /* Shift the start of ex by 'map_len' blocks */
3482 ex->ee_block = cpu_to_le32(ee_block + map_len);
3483 ext4_ext_store_pblock(ex, ee_pblk + map_len);
3484 ex->ee_len = cpu_to_le16(ee_len - map_len);
3485 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3486
3487 /* Extend abut_ex by 'map_len' blocks */
3488 abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3489
3490 /* Result: number of initialized blocks past m_lblk */
3491 allocated = map_len;
3492 }
3493 } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3494 (map_len < ee_len) && /*L1*/
3495 ex < EXT_LAST_EXTENT(eh)) { /*L2*/
3496 /* See if we can merge right */
3497 ext4_lblk_t next_lblk;
3498 ext4_fsblk_t next_pblk, ee_pblk;
3499 unsigned int next_len;
3500
3501 abut_ex = ex + 1;
3502 next_lblk = le32_to_cpu(abut_ex->ee_block);
3503 next_len = ext4_ext_get_actual_len(abut_ex);
3504 next_pblk = ext4_ext_pblock(abut_ex);
3505 ee_pblk = ext4_ext_pblock(ex);
3506
3507 /*
3508 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3509 * upon those conditions:
3510 * - C1: abut_ex is initialized,
3511 * - C2: abut_ex is logically abutting ex,
3512 * - C3: abut_ex is physically abutting ex,
3513 * - C4: abut_ex can receive the additional blocks without
3514 * overflowing the (initialized) length limit.
3515 */
3516 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3517 ((map->m_lblk + map_len) == next_lblk) && /*C2*/
3518 ((ee_pblk + ee_len) == next_pblk) && /*C3*/
3519 (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3520 err = ext4_ext_get_access(handle, inode, path + depth);
3521 if (err)
3522 goto out;
3523
3524 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3525 map, ex, abut_ex);
3526
3527 /* Shift the start of abut_ex by 'map_len' blocks */
3528 abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3529 ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3530 ex->ee_len = cpu_to_le16(ee_len - map_len);
3531 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3532
3533 /* Extend abut_ex by 'map_len' blocks */
3534 abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3535
3536 /* Result: number of initialized blocks past m_lblk */
3537 allocated = map_len;
3538 }
3539 }
3540 if (allocated) {
3541 /* Mark the block containing both extents as dirty */
3542 err = ext4_ext_dirty(handle, inode, path + depth);
3543
3544 /* Update path to point to the right extent */
3545 path[depth].p_ext = abut_ex;
3546 goto out;
3547 } else
3548 allocated = ee_len - (map->m_lblk - ee_block);
3549
3550 WARN_ON(map->m_lblk < ee_block);
3551 /*
3552 * It is safe to convert extent to initialized via explicit
3553 * zeroout only if extent is fully inside i_size or new_size.
3554 */
3555 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3556
3557 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3558 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3559 (inode->i_sb->s_blocksize_bits - 10);
3560
3561 /*
3562 * five cases:
3563 * 1. split the extent into three extents.
3564 * 2. split the extent into two extents, zeroout the head of the first
3565 * extent.
3566 * 3. split the extent into two extents, zeroout the tail of the second
3567 * extent.
3568 * 4. split the extent into two extents with out zeroout.
3569 * 5. no splitting needed, just possibly zeroout the head and / or the
3570 * tail of the extent.
3571 */
3572 split_map.m_lblk = map->m_lblk;
3573 split_map.m_len = map->m_len;
3574
3575 if (max_zeroout && (allocated > split_map.m_len)) {
3576 if (allocated <= max_zeroout) {
3577 /* case 3 or 5 */
3578 zero_ex1.ee_block =
3579 cpu_to_le32(split_map.m_lblk +
3580 split_map.m_len);
3581 zero_ex1.ee_len =
3582 cpu_to_le16(allocated - split_map.m_len);
3583 ext4_ext_store_pblock(&zero_ex1,
3584 ext4_ext_pblock(ex) + split_map.m_lblk +
3585 split_map.m_len - ee_block);
3586 err = ext4_ext_zeroout(inode, &zero_ex1);
3587 if (err)
3588 goto fallback;
3589 split_map.m_len = allocated;
3590 }
3591 if (split_map.m_lblk - ee_block + split_map.m_len <
3592 max_zeroout) {
3593 /* case 2 or 5 */
3594 if (split_map.m_lblk != ee_block) {
3595 zero_ex2.ee_block = ex->ee_block;
3596 zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk -
3597 ee_block);
3598 ext4_ext_store_pblock(&zero_ex2,
3599 ext4_ext_pblock(ex));
3600 err = ext4_ext_zeroout(inode, &zero_ex2);
3601 if (err)
3602 goto fallback;
3603 }
3604
3605 split_map.m_len += split_map.m_lblk - ee_block;
3606 split_map.m_lblk = ee_block;
3607 allocated = map->m_len;
3608 }
3609 }
3610
3611fallback:
3612 err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
3613 flags);
3614 if (err > 0)
3615 err = 0;
3616out:
3617 /* If we have gotten a failure, don't zero out status tree */
3618 if (!err) {
3619 ext4_zeroout_es(inode, &zero_ex1);
3620 ext4_zeroout_es(inode, &zero_ex2);
3621 }
3622 return err ? err : allocated;
3623}
3624
3625/*
3626 * This function is called by ext4_ext_map_blocks() from
3627 * ext4_get_blocks_dio_write() when DIO to write
3628 * to an unwritten extent.
3629 *
3630 * Writing to an unwritten extent may result in splitting the unwritten
3631 * extent into multiple initialized/unwritten extents (up to three)
3632 * There are three possibilities:
3633 * a> There is no split required: Entire extent should be unwritten
3634 * b> Splits in two extents: Write is happening at either end of the extent
3635 * c> Splits in three extents: Somone is writing in middle of the extent
3636 *
3637 * This works the same way in the case of initialized -> unwritten conversion.
3638 *
3639 * One of more index blocks maybe needed if the extent tree grow after
3640 * the unwritten extent split. To prevent ENOSPC occur at the IO
3641 * complete, we need to split the unwritten extent before DIO submit
3642 * the IO. The unwritten extent called at this time will be split
3643 * into three unwritten extent(at most). After IO complete, the part
3644 * being filled will be convert to initialized by the end_io callback function
3645 * via ext4_convert_unwritten_extents().
3646 *
3647 * Returns the size of unwritten extent to be written on success.
3648 */
3649static int ext4_split_convert_extents(handle_t *handle,
3650 struct inode *inode,
3651 struct ext4_map_blocks *map,
3652 struct ext4_ext_path **ppath,
3653 int flags)
3654{
3655 struct ext4_ext_path *path = *ppath;
3656 ext4_lblk_t eof_block;
3657 ext4_lblk_t ee_block;
3658 struct ext4_extent *ex;
3659 unsigned int ee_len;
3660 int split_flag = 0, depth;
3661
3662 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3663 (unsigned long long)map->m_lblk, map->m_len);
3664
3665 eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1)
3666 >> inode->i_sb->s_blocksize_bits;
3667 if (eof_block < map->m_lblk + map->m_len)
3668 eof_block = map->m_lblk + map->m_len;
3669 /*
3670 * It is safe to convert extent to initialized via explicit
3671 * zeroout only if extent is fully inside i_size or new_size.
3672 */
3673 depth = ext_depth(inode);
3674 ex = path[depth].p_ext;
3675 ee_block = le32_to_cpu(ex->ee_block);
3676 ee_len = ext4_ext_get_actual_len(ex);
3677
3678 /* Convert to unwritten */
3679 if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
3680 split_flag |= EXT4_EXT_DATA_VALID1;
3681 /* Convert to initialized */
3682 } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
3683 split_flag |= ee_block + ee_len <= eof_block ?
3684 EXT4_EXT_MAY_ZEROOUT : 0;
3685 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
3686 }
3687 flags |= EXT4_GET_BLOCKS_PRE_IO;
3688 return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
3689}
3690
3691static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3692 struct inode *inode,
3693 struct ext4_map_blocks *map,
3694 struct ext4_ext_path **ppath)
3695{
3696 struct ext4_ext_path *path = *ppath;
3697 struct ext4_extent *ex;
3698 ext4_lblk_t ee_block;
3699 unsigned int ee_len;
3700 int depth;
3701 int err = 0;
3702
3703 depth = ext_depth(inode);
3704 ex = path[depth].p_ext;
3705 ee_block = le32_to_cpu(ex->ee_block);
3706 ee_len = ext4_ext_get_actual_len(ex);
3707
3708 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3709 (unsigned long long)ee_block, ee_len);
3710
3711 /* If extent is larger than requested it is a clear sign that we still
3712 * have some extent state machine issues left. So extent_split is still
3713 * required.
3714 * TODO: Once all related issues will be fixed this situation should be
3715 * illegal.
3716 */
3717 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3718#ifdef CONFIG_EXT4_DEBUG
3719 ext4_warning(inode->i_sb, "Inode (%ld) finished: extent logical block %llu,"
3720 " len %u; IO logical block %llu, len %u",
3721 inode->i_ino, (unsigned long long)ee_block, ee_len,
3722 (unsigned long long)map->m_lblk, map->m_len);
3723#endif
3724 err = ext4_split_convert_extents(handle, inode, map, ppath,
3725 EXT4_GET_BLOCKS_CONVERT);
3726 if (err < 0)
3727 return err;
3728 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3729 if (IS_ERR(path))
3730 return PTR_ERR(path);
3731 depth = ext_depth(inode);
3732 ex = path[depth].p_ext;
3733 }
3734
3735 err = ext4_ext_get_access(handle, inode, path + depth);
3736 if (err)
3737 goto out;
3738 /* first mark the extent as initialized */
3739 ext4_ext_mark_initialized(ex);
3740
3741 /* note: ext4_ext_correct_indexes() isn't needed here because
3742 * borders are not changed
3743 */
3744 ext4_ext_try_to_merge(handle, inode, path, ex);
3745
3746 /* Mark modified extent as dirty */
3747 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3748out:
3749 ext4_ext_show_leaf(inode, path);
3750 return err;
3751}
3752
3753static int
3754convert_initialized_extent(handle_t *handle, struct inode *inode,
3755 struct ext4_map_blocks *map,
3756 struct ext4_ext_path **ppath,
3757 unsigned int *allocated)
3758{
3759 struct ext4_ext_path *path = *ppath;
3760 struct ext4_extent *ex;
3761 ext4_lblk_t ee_block;
3762 unsigned int ee_len;
3763 int depth;
3764 int err = 0;
3765
3766 /*
3767 * Make sure that the extent is no bigger than we support with
3768 * unwritten extent
3769 */
3770 if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
3771 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
3772
3773 depth = ext_depth(inode);
3774 ex = path[depth].p_ext;
3775 ee_block = le32_to_cpu(ex->ee_block);
3776 ee_len = ext4_ext_get_actual_len(ex);
3777
3778 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3779 (unsigned long long)ee_block, ee_len);
3780
3781 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3782 err = ext4_split_convert_extents(handle, inode, map, ppath,
3783 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
3784 if (err < 0)
3785 return err;
3786 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3787 if (IS_ERR(path))
3788 return PTR_ERR(path);
3789 depth = ext_depth(inode);
3790 ex = path[depth].p_ext;
3791 if (!ex) {
3792 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3793 (unsigned long) map->m_lblk);
3794 return -EFSCORRUPTED;
3795 }
3796 }
3797
3798 err = ext4_ext_get_access(handle, inode, path + depth);
3799 if (err)
3800 return err;
3801 /* first mark the extent as unwritten */
3802 ext4_ext_mark_unwritten(ex);
3803
3804 /* note: ext4_ext_correct_indexes() isn't needed here because
3805 * borders are not changed
3806 */
3807 ext4_ext_try_to_merge(handle, inode, path, ex);
3808
3809 /* Mark modified extent as dirty */
3810 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3811 if (err)
3812 return err;
3813 ext4_ext_show_leaf(inode, path);
3814
3815 ext4_update_inode_fsync_trans(handle, inode, 1);
3816
3817 map->m_flags |= EXT4_MAP_UNWRITTEN;
3818 if (*allocated > map->m_len)
3819 *allocated = map->m_len;
3820 map->m_len = *allocated;
3821 return 0;
3822}
3823
3824static int
3825ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
3826 struct ext4_map_blocks *map,
3827 struct ext4_ext_path **ppath, int flags,
3828 unsigned int allocated, ext4_fsblk_t newblock)
3829{
3830 struct ext4_ext_path __maybe_unused *path = *ppath;
3831 int ret = 0;
3832 int err = 0;
3833
3834 ext_debug(inode, "logical block %llu, max_blocks %u, flags 0x%x, allocated %u\n",
3835 (unsigned long long)map->m_lblk, map->m_len, flags,
3836 allocated);
3837 ext4_ext_show_leaf(inode, path);
3838
3839 /*
3840 * When writing into unwritten space, we should not fail to
3841 * allocate metadata blocks for the new extent block if needed.
3842 */
3843 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
3844
3845 trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
3846 allocated, newblock);
3847
3848 /* get_block() before submitting IO, split the extent */
3849 if (flags & EXT4_GET_BLOCKS_PRE_IO) {
3850 ret = ext4_split_convert_extents(handle, inode, map, ppath,
3851 flags | EXT4_GET_BLOCKS_CONVERT);
3852 if (ret < 0) {
3853 err = ret;
3854 goto out2;
3855 }
3856 /*
3857 * shouldn't get a 0 return when splitting an extent unless
3858 * m_len is 0 (bug) or extent has been corrupted
3859 */
3860 if (unlikely(ret == 0)) {
3861 EXT4_ERROR_INODE(inode,
3862 "unexpected ret == 0, m_len = %u",
3863 map->m_len);
3864 err = -EFSCORRUPTED;
3865 goto out2;
3866 }
3867 map->m_flags |= EXT4_MAP_UNWRITTEN;
3868 goto out;
3869 }
3870 /* IO end_io complete, convert the filled extent to written */
3871 if (flags & EXT4_GET_BLOCKS_CONVERT) {
3872 err = ext4_convert_unwritten_extents_endio(handle, inode, map,
3873 ppath);
3874 if (err < 0)
3875 goto out2;
3876 ext4_update_inode_fsync_trans(handle, inode, 1);
3877 goto map_out;
3878 }
3879 /* buffered IO cases */
3880 /*
3881 * repeat fallocate creation request
3882 * we already have an unwritten extent
3883 */
3884 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
3885 map->m_flags |= EXT4_MAP_UNWRITTEN;
3886 goto map_out;
3887 }
3888
3889 /* buffered READ or buffered write_begin() lookup */
3890 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3891 /*
3892 * We have blocks reserved already. We
3893 * return allocated blocks so that delalloc
3894 * won't do block reservation for us. But
3895 * the buffer head will be unmapped so that
3896 * a read from the block returns 0s.
3897 */
3898 map->m_flags |= EXT4_MAP_UNWRITTEN;
3899 goto out1;
3900 }
3901
3902 /*
3903 * Default case when (flags & EXT4_GET_BLOCKS_CREATE) == 1.
3904 * For buffered writes, at writepage time, etc. Convert a
3905 * discovered unwritten extent to written.
3906 */
3907 ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags);
3908 if (ret < 0) {
3909 err = ret;
3910 goto out2;
3911 }
3912 ext4_update_inode_fsync_trans(handle, inode, 1);
3913 /*
3914 * shouldn't get a 0 return when converting an unwritten extent
3915 * unless m_len is 0 (bug) or extent has been corrupted
3916 */
3917 if (unlikely(ret == 0)) {
3918 EXT4_ERROR_INODE(inode, "unexpected ret == 0, m_len = %u",
3919 map->m_len);
3920 err = -EFSCORRUPTED;
3921 goto out2;
3922 }
3923
3924out:
3925 allocated = ret;
3926 map->m_flags |= EXT4_MAP_NEW;
3927map_out:
3928 map->m_flags |= EXT4_MAP_MAPPED;
3929out1:
3930 map->m_pblk = newblock;
3931 if (allocated > map->m_len)
3932 allocated = map->m_len;
3933 map->m_len = allocated;
3934 ext4_ext_show_leaf(inode, path);
3935out2:
3936 return err ? err : allocated;
3937}
3938
3939/*
3940 * get_implied_cluster_alloc - check to see if the requested
3941 * allocation (in the map structure) overlaps with a cluster already
3942 * allocated in an extent.
3943 * @sb The filesystem superblock structure
3944 * @map The requested lblk->pblk mapping
3945 * @ex The extent structure which might contain an implied
3946 * cluster allocation
3947 *
3948 * This function is called by ext4_ext_map_blocks() after we failed to
3949 * find blocks that were already in the inode's extent tree. Hence,
3950 * we know that the beginning of the requested region cannot overlap
3951 * the extent from the inode's extent tree. There are three cases we
3952 * want to catch. The first is this case:
3953 *
3954 * |--- cluster # N--|
3955 * |--- extent ---| |---- requested region ---|
3956 * |==========|
3957 *
3958 * The second case that we need to test for is this one:
3959 *
3960 * |--------- cluster # N ----------------|
3961 * |--- requested region --| |------- extent ----|
3962 * |=======================|
3963 *
3964 * The third case is when the requested region lies between two extents
3965 * within the same cluster:
3966 * |------------- cluster # N-------------|
3967 * |----- ex -----| |---- ex_right ----|
3968 * |------ requested region ------|
3969 * |================|
3970 *
3971 * In each of the above cases, we need to set the map->m_pblk and
3972 * map->m_len so it corresponds to the return the extent labelled as
3973 * "|====|" from cluster #N, since it is already in use for data in
3974 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
3975 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
3976 * as a new "allocated" block region. Otherwise, we will return 0 and
3977 * ext4_ext_map_blocks() will then allocate one or more new clusters
3978 * by calling ext4_mb_new_blocks().
3979 */
3980static int get_implied_cluster_alloc(struct super_block *sb,
3981 struct ext4_map_blocks *map,
3982 struct ext4_extent *ex,
3983 struct ext4_ext_path *path)
3984{
3985 struct ext4_sb_info *sbi = EXT4_SB(sb);
3986 ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
3987 ext4_lblk_t ex_cluster_start, ex_cluster_end;
3988 ext4_lblk_t rr_cluster_start;
3989 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
3990 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
3991 unsigned short ee_len = ext4_ext_get_actual_len(ex);
3992
3993 /* The extent passed in that we are trying to match */
3994 ex_cluster_start = EXT4_B2C(sbi, ee_block);
3995 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
3996
3997 /* The requested region passed into ext4_map_blocks() */
3998 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
3999
4000 if ((rr_cluster_start == ex_cluster_end) ||
4001 (rr_cluster_start == ex_cluster_start)) {
4002 if (rr_cluster_start == ex_cluster_end)
4003 ee_start += ee_len - 1;
4004 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
4005 map->m_len = min(map->m_len,
4006 (unsigned) sbi->s_cluster_ratio - c_offset);
4007 /*
4008 * Check for and handle this case:
4009 *
4010 * |--------- cluster # N-------------|
4011 * |------- extent ----|
4012 * |--- requested region ---|
4013 * |===========|
4014 */
4015
4016 if (map->m_lblk < ee_block)
4017 map->m_len = min(map->m_len, ee_block - map->m_lblk);
4018
4019 /*
4020 * Check for the case where there is already another allocated
4021 * block to the right of 'ex' but before the end of the cluster.
4022 *
4023 * |------------- cluster # N-------------|
4024 * |----- ex -----| |---- ex_right ----|
4025 * |------ requested region ------|
4026 * |================|
4027 */
4028 if (map->m_lblk > ee_block) {
4029 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4030 map->m_len = min(map->m_len, next - map->m_lblk);
4031 }
4032
4033 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4034 return 1;
4035 }
4036
4037 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4038 return 0;
4039}
4040
4041/*
4042 * Determine hole length around the given logical block, first try to
4043 * locate and expand the hole from the given @path, and then adjust it
4044 * if it's partially or completely converted to delayed extents, insert
4045 * it into the extent cache tree if it's indeed a hole, finally return
4046 * the length of the determined extent.
4047 */
4048static ext4_lblk_t ext4_ext_determine_insert_hole(struct inode *inode,
4049 struct ext4_ext_path *path,
4050 ext4_lblk_t lblk)
4051{
4052 ext4_lblk_t hole_start, len;
4053 struct extent_status es;
4054
4055 hole_start = lblk;
4056 len = ext4_ext_find_hole(inode, path, &hole_start);
4057again:
4058 ext4_es_find_extent_range(inode, &ext4_es_is_delayed, hole_start,
4059 hole_start + len - 1, &es);
4060 if (!es.es_len)
4061 goto insert_hole;
4062
4063 /*
4064 * There's a delalloc extent in the hole, handle it if the delalloc
4065 * extent is in front of, behind and straddle the queried range.
4066 */
4067 if (lblk >= es.es_lblk + es.es_len) {
4068 /*
4069 * The delalloc extent is in front of the queried range,
4070 * find again from the queried start block.
4071 */
4072 len -= lblk - hole_start;
4073 hole_start = lblk;
4074 goto again;
4075 } else if (in_range(lblk, es.es_lblk, es.es_len)) {
4076 /*
4077 * The delalloc extent containing lblk, it must have been
4078 * added after ext4_map_blocks() checked the extent status
4079 * tree so we are not holding i_rwsem and delalloc info is
4080 * only stabilized by i_data_sem we are going to release
4081 * soon. Don't modify the extent status tree and report
4082 * extent as a hole, just adjust the length to the delalloc
4083 * extent's after lblk.
4084 */
4085 len = es.es_lblk + es.es_len - lblk;
4086 return len;
4087 } else {
4088 /*
4089 * The delalloc extent is partially or completely behind
4090 * the queried range, update hole length until the
4091 * beginning of the delalloc extent.
4092 */
4093 len = min(es.es_lblk - hole_start, len);
4094 }
4095
4096insert_hole:
4097 /* Put just found gap into cache to speed up subsequent requests */
4098 ext_debug(inode, " -> %u:%u\n", hole_start, len);
4099 ext4_es_insert_extent(inode, hole_start, len, ~0, EXTENT_STATUS_HOLE);
4100
4101 /* Update hole_len to reflect hole size after lblk */
4102 if (hole_start != lblk)
4103 len -= lblk - hole_start;
4104
4105 return len;
4106}
4107
4108/*
4109 * Block allocation/map/preallocation routine for extents based files
4110 *
4111 *
4112 * Need to be called with
4113 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4114 * (ie, flags is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4115 *
4116 * return > 0, number of blocks already mapped/allocated
4117 * if flags doesn't contain EXT4_GET_BLOCKS_CREATE and these are pre-allocated blocks
4118 * buffer head is unmapped
4119 * otherwise blocks are mapped
4120 *
4121 * return = 0, if plain look up failed (blocks have not been allocated)
4122 * buffer head is unmapped
4123 *
4124 * return < 0, error case.
4125 */
4126int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4127 struct ext4_map_blocks *map, int flags)
4128{
4129 struct ext4_ext_path *path = NULL;
4130 struct ext4_extent newex, *ex, ex2;
4131 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4132 ext4_fsblk_t newblock = 0, pblk;
4133 int err = 0, depth, ret;
4134 unsigned int allocated = 0, offset = 0;
4135 unsigned int allocated_clusters = 0;
4136 struct ext4_allocation_request ar;
4137 ext4_lblk_t cluster_offset;
4138
4139 ext_debug(inode, "blocks %u/%u requested\n", map->m_lblk, map->m_len);
4140 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4141
4142 /* find extent for this block */
4143 path = ext4_find_extent(inode, map->m_lblk, NULL, 0);
4144 if (IS_ERR(path)) {
4145 err = PTR_ERR(path);
4146 path = NULL;
4147 goto out;
4148 }
4149
4150 depth = ext_depth(inode);
4151
4152 /*
4153 * consistent leaf must not be empty;
4154 * this situation is possible, though, _during_ tree modification;
4155 * this is why assert can't be put in ext4_find_extent()
4156 */
4157 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4158 EXT4_ERROR_INODE(inode, "bad extent address "
4159 "lblock: %lu, depth: %d pblock %lld",
4160 (unsigned long) map->m_lblk, depth,
4161 path[depth].p_block);
4162 err = -EFSCORRUPTED;
4163 goto out;
4164 }
4165
4166 ex = path[depth].p_ext;
4167 if (ex) {
4168 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4169 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4170 unsigned short ee_len;
4171
4172
4173 /*
4174 * unwritten extents are treated as holes, except that
4175 * we split out initialized portions during a write.
4176 */
4177 ee_len = ext4_ext_get_actual_len(ex);
4178
4179 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4180
4181 /* if found extent covers block, simply return it */
4182 if (in_range(map->m_lblk, ee_block, ee_len)) {
4183 newblock = map->m_lblk - ee_block + ee_start;
4184 /* number of remaining blocks in the extent */
4185 allocated = ee_len - (map->m_lblk - ee_block);
4186 ext_debug(inode, "%u fit into %u:%d -> %llu\n",
4187 map->m_lblk, ee_block, ee_len, newblock);
4188
4189 /*
4190 * If the extent is initialized check whether the
4191 * caller wants to convert it to unwritten.
4192 */
4193 if ((!ext4_ext_is_unwritten(ex)) &&
4194 (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
4195 err = convert_initialized_extent(handle,
4196 inode, map, &path, &allocated);
4197 goto out;
4198 } else if (!ext4_ext_is_unwritten(ex)) {
4199 map->m_flags |= EXT4_MAP_MAPPED;
4200 map->m_pblk = newblock;
4201 if (allocated > map->m_len)
4202 allocated = map->m_len;
4203 map->m_len = allocated;
4204 ext4_ext_show_leaf(inode, path);
4205 goto out;
4206 }
4207
4208 ret = ext4_ext_handle_unwritten_extents(
4209 handle, inode, map, &path, flags,
4210 allocated, newblock);
4211 if (ret < 0)
4212 err = ret;
4213 else
4214 allocated = ret;
4215 goto out;
4216 }
4217 }
4218
4219 /*
4220 * requested block isn't allocated yet;
4221 * we couldn't try to create block if flags doesn't contain EXT4_GET_BLOCKS_CREATE
4222 */
4223 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4224 ext4_lblk_t len;
4225
4226 len = ext4_ext_determine_insert_hole(inode, path, map->m_lblk);
4227
4228 map->m_pblk = 0;
4229 map->m_len = min_t(unsigned int, map->m_len, len);
4230 goto out;
4231 }
4232
4233 /*
4234 * Okay, we need to do block allocation.
4235 */
4236 newex.ee_block = cpu_to_le32(map->m_lblk);
4237 cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4238
4239 /*
4240 * If we are doing bigalloc, check to see if the extent returned
4241 * by ext4_find_extent() implies a cluster we can use.
4242 */
4243 if (cluster_offset && ex &&
4244 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4245 ar.len = allocated = map->m_len;
4246 newblock = map->m_pblk;
4247 goto got_allocated_blocks;
4248 }
4249
4250 /* find neighbour allocated blocks */
4251 ar.lleft = map->m_lblk;
4252 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4253 if (err)
4254 goto out;
4255 ar.lright = map->m_lblk;
4256 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4257 if (err < 0)
4258 goto out;
4259
4260 /* Check if the extent after searching to the right implies a
4261 * cluster we can use. */
4262 if ((sbi->s_cluster_ratio > 1) && err &&
4263 get_implied_cluster_alloc(inode->i_sb, map, &ex2, path)) {
4264 ar.len = allocated = map->m_len;
4265 newblock = map->m_pblk;
4266 goto got_allocated_blocks;
4267 }
4268
4269 /*
4270 * See if request is beyond maximum number of blocks we can have in
4271 * a single extent. For an initialized extent this limit is
4272 * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
4273 * EXT_UNWRITTEN_MAX_LEN.
4274 */
4275 if (map->m_len > EXT_INIT_MAX_LEN &&
4276 !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4277 map->m_len = EXT_INIT_MAX_LEN;
4278 else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
4279 (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4280 map->m_len = EXT_UNWRITTEN_MAX_LEN;
4281
4282 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4283 newex.ee_len = cpu_to_le16(map->m_len);
4284 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4285 if (err)
4286 allocated = ext4_ext_get_actual_len(&newex);
4287 else
4288 allocated = map->m_len;
4289
4290 /* allocate new block */
4291 ar.inode = inode;
4292 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4293 ar.logical = map->m_lblk;
4294 /*
4295 * We calculate the offset from the beginning of the cluster
4296 * for the logical block number, since when we allocate a
4297 * physical cluster, the physical block should start at the
4298 * same offset from the beginning of the cluster. This is
4299 * needed so that future calls to get_implied_cluster_alloc()
4300 * work correctly.
4301 */
4302 offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4303 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4304 ar.goal -= offset;
4305 ar.logical -= offset;
4306 if (S_ISREG(inode->i_mode))
4307 ar.flags = EXT4_MB_HINT_DATA;
4308 else
4309 /* disable in-core preallocation for non-regular files */
4310 ar.flags = 0;
4311 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4312 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4313 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4314 ar.flags |= EXT4_MB_DELALLOC_RESERVED;
4315 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
4316 ar.flags |= EXT4_MB_USE_RESERVED;
4317 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4318 if (!newblock)
4319 goto out;
4320 allocated_clusters = ar.len;
4321 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4322 ext_debug(inode, "allocate new block: goal %llu, found %llu/%u, requested %u\n",
4323 ar.goal, newblock, ar.len, allocated);
4324 if (ar.len > allocated)
4325 ar.len = allocated;
4326
4327got_allocated_blocks:
4328 /* try to insert new extent into found leaf and return */
4329 pblk = newblock + offset;
4330 ext4_ext_store_pblock(&newex, pblk);
4331 newex.ee_len = cpu_to_le16(ar.len);
4332 /* Mark unwritten */
4333 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
4334 ext4_ext_mark_unwritten(&newex);
4335 map->m_flags |= EXT4_MAP_UNWRITTEN;
4336 }
4337
4338 err = ext4_ext_insert_extent(handle, inode, &path, &newex, flags);
4339 if (err) {
4340 if (allocated_clusters) {
4341 int fb_flags = 0;
4342
4343 /*
4344 * free data blocks we just allocated.
4345 * not a good idea to call discard here directly,
4346 * but otherwise we'd need to call it every free().
4347 */
4348 ext4_discard_preallocations(inode);
4349 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4350 fb_flags = EXT4_FREE_BLOCKS_NO_QUOT_UPDATE;
4351 ext4_free_blocks(handle, inode, NULL, newblock,
4352 EXT4_C2B(sbi, allocated_clusters),
4353 fb_flags);
4354 }
4355 goto out;
4356 }
4357
4358 /*
4359 * Reduce the reserved cluster count to reflect successful deferred
4360 * allocation of delayed allocated clusters or direct allocation of
4361 * clusters discovered to be delayed allocated. Once allocated, a
4362 * cluster is not included in the reserved count.
4363 */
4364 if (test_opt(inode->i_sb, DELALLOC) && allocated_clusters) {
4365 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4366 /*
4367 * When allocating delayed allocated clusters, simply
4368 * reduce the reserved cluster count and claim quota
4369 */
4370 ext4_da_update_reserve_space(inode, allocated_clusters,
4371 1);
4372 } else {
4373 ext4_lblk_t lblk, len;
4374 unsigned int n;
4375
4376 /*
4377 * When allocating non-delayed allocated clusters
4378 * (from fallocate, filemap, DIO, or clusters
4379 * allocated when delalloc has been disabled by
4380 * ext4_nonda_switch), reduce the reserved cluster
4381 * count by the number of allocated clusters that
4382 * have previously been delayed allocated. Quota
4383 * has been claimed by ext4_mb_new_blocks() above,
4384 * so release the quota reservations made for any
4385 * previously delayed allocated clusters.
4386 */
4387 lblk = EXT4_LBLK_CMASK(sbi, map->m_lblk);
4388 len = allocated_clusters << sbi->s_cluster_bits;
4389 n = ext4_es_delayed_clu(inode, lblk, len);
4390 if (n > 0)
4391 ext4_da_update_reserve_space(inode, (int) n, 0);
4392 }
4393 }
4394
4395 /*
4396 * Cache the extent and update transaction to commit on fdatasync only
4397 * when it is _not_ an unwritten extent.
4398 */
4399 if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
4400 ext4_update_inode_fsync_trans(handle, inode, 1);
4401 else
4402 ext4_update_inode_fsync_trans(handle, inode, 0);
4403
4404 map->m_flags |= (EXT4_MAP_NEW | EXT4_MAP_MAPPED);
4405 map->m_pblk = pblk;
4406 map->m_len = ar.len;
4407 allocated = map->m_len;
4408 ext4_ext_show_leaf(inode, path);
4409out:
4410 ext4_free_ext_path(path);
4411
4412 trace_ext4_ext_map_blocks_exit(inode, flags, map,
4413 err ? err : allocated);
4414 return err ? err : allocated;
4415}
4416
4417int ext4_ext_truncate(handle_t *handle, struct inode *inode)
4418{
4419 struct super_block *sb = inode->i_sb;
4420 ext4_lblk_t last_block;
4421 int err = 0;
4422
4423 /*
4424 * TODO: optimization is possible here.
4425 * Probably we need not scan at all,
4426 * because page truncation is enough.
4427 */
4428
4429 /* we have to know where to truncate from in crash case */
4430 EXT4_I(inode)->i_disksize = inode->i_size;
4431 err = ext4_mark_inode_dirty(handle, inode);
4432 if (err)
4433 return err;
4434
4435 last_block = (inode->i_size + sb->s_blocksize - 1)
4436 >> EXT4_BLOCK_SIZE_BITS(sb);
4437 ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block);
4438
4439retry_remove_space:
4440 err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4441 if (err == -ENOMEM) {
4442 memalloc_retry_wait(GFP_ATOMIC);
4443 goto retry_remove_space;
4444 }
4445 return err;
4446}
4447
4448static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
4449 ext4_lblk_t len, loff_t new_size,
4450 int flags)
4451{
4452 struct inode *inode = file_inode(file);
4453 handle_t *handle;
4454 int ret = 0, ret2 = 0, ret3 = 0;
4455 int retries = 0;
4456 int depth = 0;
4457 struct ext4_map_blocks map;
4458 unsigned int credits;
4459 loff_t epos;
4460
4461 BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS));
4462 map.m_lblk = offset;
4463 map.m_len = len;
4464 /*
4465 * Don't normalize the request if it can fit in one extent so
4466 * that it doesn't get unnecessarily split into multiple
4467 * extents.
4468 */
4469 if (len <= EXT_UNWRITTEN_MAX_LEN)
4470 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4471
4472 /*
4473 * credits to insert 1 extent into extent tree
4474 */
4475 credits = ext4_chunk_trans_blocks(inode, len);
4476 depth = ext_depth(inode);
4477
4478retry:
4479 while (len) {
4480 /*
4481 * Recalculate credits when extent tree depth changes.
4482 */
4483 if (depth != ext_depth(inode)) {
4484 credits = ext4_chunk_trans_blocks(inode, len);
4485 depth = ext_depth(inode);
4486 }
4487
4488 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4489 credits);
4490 if (IS_ERR(handle)) {
4491 ret = PTR_ERR(handle);
4492 break;
4493 }
4494 ret = ext4_map_blocks(handle, inode, &map, flags);
4495 if (ret <= 0) {
4496 ext4_debug("inode #%lu: block %u: len %u: "
4497 "ext4_ext_map_blocks returned %d",
4498 inode->i_ino, map.m_lblk,
4499 map.m_len, ret);
4500 ext4_mark_inode_dirty(handle, inode);
4501 ext4_journal_stop(handle);
4502 break;
4503 }
4504 /*
4505 * allow a full retry cycle for any remaining allocations
4506 */
4507 retries = 0;
4508 map.m_lblk += ret;
4509 map.m_len = len = len - ret;
4510 epos = (loff_t)map.m_lblk << inode->i_blkbits;
4511 inode_set_ctime_current(inode);
4512 if (new_size) {
4513 if (epos > new_size)
4514 epos = new_size;
4515 if (ext4_update_inode_size(inode, epos) & 0x1)
4516 inode_set_mtime_to_ts(inode,
4517 inode_get_ctime(inode));
4518 }
4519 ret2 = ext4_mark_inode_dirty(handle, inode);
4520 ext4_update_inode_fsync_trans(handle, inode, 1);
4521 ret3 = ext4_journal_stop(handle);
4522 ret2 = ret3 ? ret3 : ret2;
4523 if (unlikely(ret2))
4524 break;
4525 }
4526 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
4527 goto retry;
4528
4529 return ret > 0 ? ret2 : ret;
4530}
4531
4532static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len);
4533
4534static int ext4_insert_range(struct file *file, loff_t offset, loff_t len);
4535
4536static long ext4_zero_range(struct file *file, loff_t offset,
4537 loff_t len, int mode)
4538{
4539 struct inode *inode = file_inode(file);
4540 struct address_space *mapping = file->f_mapping;
4541 handle_t *handle = NULL;
4542 unsigned int max_blocks;
4543 loff_t new_size = 0;
4544 int ret = 0;
4545 int flags;
4546 int credits;
4547 int partial_begin, partial_end;
4548 loff_t start, end;
4549 ext4_lblk_t lblk;
4550 unsigned int blkbits = inode->i_blkbits;
4551
4552 trace_ext4_zero_range(inode, offset, len, mode);
4553
4554 /*
4555 * Round up offset. This is not fallocate, we need to zero out
4556 * blocks, so convert interior block aligned part of the range to
4557 * unwritten and possibly manually zero out unaligned parts of the
4558 * range. Here, start and partial_begin are inclusive, end and
4559 * partial_end are exclusive.
4560 */
4561 start = round_up(offset, 1 << blkbits);
4562 end = round_down((offset + len), 1 << blkbits);
4563
4564 if (start < offset || end > offset + len)
4565 return -EINVAL;
4566 partial_begin = offset & ((1 << blkbits) - 1);
4567 partial_end = (offset + len) & ((1 << blkbits) - 1);
4568
4569 lblk = start >> blkbits;
4570 max_blocks = (end >> blkbits);
4571 if (max_blocks < lblk)
4572 max_blocks = 0;
4573 else
4574 max_blocks -= lblk;
4575
4576 inode_lock(inode);
4577
4578 /*
4579 * Indirect files do not support unwritten extents
4580 */
4581 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4582 ret = -EOPNOTSUPP;
4583 goto out_mutex;
4584 }
4585
4586 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4587 (offset + len > inode->i_size ||
4588 offset + len > EXT4_I(inode)->i_disksize)) {
4589 new_size = offset + len;
4590 ret = inode_newsize_ok(inode, new_size);
4591 if (ret)
4592 goto out_mutex;
4593 }
4594
4595 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4596
4597 /* Wait all existing dio workers, newcomers will block on i_rwsem */
4598 inode_dio_wait(inode);
4599
4600 ret = file_modified(file);
4601 if (ret)
4602 goto out_mutex;
4603
4604 /* Preallocate the range including the unaligned edges */
4605 if (partial_begin || partial_end) {
4606 ret = ext4_alloc_file_blocks(file,
4607 round_down(offset, 1 << blkbits) >> blkbits,
4608 (round_up((offset + len), 1 << blkbits) -
4609 round_down(offset, 1 << blkbits)) >> blkbits,
4610 new_size, flags);
4611 if (ret)
4612 goto out_mutex;
4613
4614 }
4615
4616 /* Zero range excluding the unaligned edges */
4617 if (max_blocks > 0) {
4618 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
4619 EXT4_EX_NOCACHE);
4620
4621 /*
4622 * Prevent page faults from reinstantiating pages we have
4623 * released from page cache.
4624 */
4625 filemap_invalidate_lock(mapping);
4626
4627 ret = ext4_break_layouts(inode);
4628 if (ret) {
4629 filemap_invalidate_unlock(mapping);
4630 goto out_mutex;
4631 }
4632
4633 ret = ext4_update_disksize_before_punch(inode, offset, len);
4634 if (ret) {
4635 filemap_invalidate_unlock(mapping);
4636 goto out_mutex;
4637 }
4638
4639 /*
4640 * For journalled data we need to write (and checkpoint) pages
4641 * before discarding page cache to avoid inconsitent data on
4642 * disk in case of crash before zeroing trans is committed.
4643 */
4644 if (ext4_should_journal_data(inode)) {
4645 ret = filemap_write_and_wait_range(mapping, start,
4646 end - 1);
4647 if (ret) {
4648 filemap_invalidate_unlock(mapping);
4649 goto out_mutex;
4650 }
4651 }
4652
4653 /* Now release the pages and zero block aligned part of pages */
4654 truncate_pagecache_range(inode, start, end - 1);
4655 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
4656
4657 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4658 flags);
4659 filemap_invalidate_unlock(mapping);
4660 if (ret)
4661 goto out_mutex;
4662 }
4663 if (!partial_begin && !partial_end)
4664 goto out_mutex;
4665
4666 /*
4667 * In worst case we have to writeout two nonadjacent unwritten
4668 * blocks and update the inode
4669 */
4670 credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
4671 if (ext4_should_journal_data(inode))
4672 credits += 2;
4673 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
4674 if (IS_ERR(handle)) {
4675 ret = PTR_ERR(handle);
4676 ext4_std_error(inode->i_sb, ret);
4677 goto out_mutex;
4678 }
4679
4680 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
4681 if (new_size)
4682 ext4_update_inode_size(inode, new_size);
4683 ret = ext4_mark_inode_dirty(handle, inode);
4684 if (unlikely(ret))
4685 goto out_handle;
4686 /* Zero out partial block at the edges of the range */
4687 ret = ext4_zero_partial_blocks(handle, inode, offset, len);
4688 if (ret >= 0)
4689 ext4_update_inode_fsync_trans(handle, inode, 1);
4690
4691 if (file->f_flags & O_SYNC)
4692 ext4_handle_sync(handle);
4693
4694out_handle:
4695 ext4_journal_stop(handle);
4696out_mutex:
4697 inode_unlock(inode);
4698 return ret;
4699}
4700
4701/*
4702 * preallocate space for a file. This implements ext4's fallocate file
4703 * operation, which gets called from sys_fallocate system call.
4704 * For block-mapped files, posix_fallocate should fall back to the method
4705 * of writing zeroes to the required new blocks (the same behavior which is
4706 * expected for file systems which do not support fallocate() system call).
4707 */
4708long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4709{
4710 struct inode *inode = file_inode(file);
4711 loff_t new_size = 0;
4712 unsigned int max_blocks;
4713 int ret = 0;
4714 int flags;
4715 ext4_lblk_t lblk;
4716 unsigned int blkbits = inode->i_blkbits;
4717
4718 /*
4719 * Encrypted inodes can't handle collapse range or insert
4720 * range since we would need to re-encrypt blocks with a
4721 * different IV or XTS tweak (which are based on the logical
4722 * block number).
4723 */
4724 if (IS_ENCRYPTED(inode) &&
4725 (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE)))
4726 return -EOPNOTSUPP;
4727
4728 /* Return error if mode is not supported */
4729 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
4730 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
4731 FALLOC_FL_INSERT_RANGE))
4732 return -EOPNOTSUPP;
4733
4734 inode_lock(inode);
4735 ret = ext4_convert_inline_data(inode);
4736 inode_unlock(inode);
4737 if (ret)
4738 goto exit;
4739
4740 if (mode & FALLOC_FL_PUNCH_HOLE) {
4741 ret = ext4_punch_hole(file, offset, len);
4742 goto exit;
4743 }
4744
4745 if (mode & FALLOC_FL_COLLAPSE_RANGE) {
4746 ret = ext4_collapse_range(file, offset, len);
4747 goto exit;
4748 }
4749
4750 if (mode & FALLOC_FL_INSERT_RANGE) {
4751 ret = ext4_insert_range(file, offset, len);
4752 goto exit;
4753 }
4754
4755 if (mode & FALLOC_FL_ZERO_RANGE) {
4756 ret = ext4_zero_range(file, offset, len, mode);
4757 goto exit;
4758 }
4759 trace_ext4_fallocate_enter(inode, offset, len, mode);
4760 lblk = offset >> blkbits;
4761
4762 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
4763 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4764
4765 inode_lock(inode);
4766
4767 /*
4768 * We only support preallocation for extent-based files only
4769 */
4770 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4771 ret = -EOPNOTSUPP;
4772 goto out;
4773 }
4774
4775 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4776 (offset + len > inode->i_size ||
4777 offset + len > EXT4_I(inode)->i_disksize)) {
4778 new_size = offset + len;
4779 ret = inode_newsize_ok(inode, new_size);
4780 if (ret)
4781 goto out;
4782 }
4783
4784 /* Wait all existing dio workers, newcomers will block on i_rwsem */
4785 inode_dio_wait(inode);
4786
4787 ret = file_modified(file);
4788 if (ret)
4789 goto out;
4790
4791 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags);
4792 if (ret)
4793 goto out;
4794
4795 if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
4796 ret = ext4_fc_commit(EXT4_SB(inode->i_sb)->s_journal,
4797 EXT4_I(inode)->i_sync_tid);
4798 }
4799out:
4800 inode_unlock(inode);
4801 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4802exit:
4803 return ret;
4804}
4805
4806/*
4807 * This function convert a range of blocks to written extents
4808 * The caller of this function will pass the start offset and the size.
4809 * all unwritten extents within this range will be converted to
4810 * written extents.
4811 *
4812 * This function is called from the direct IO end io call back
4813 * function, to convert the fallocated extents after IO is completed.
4814 * Returns 0 on success.
4815 */
4816int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
4817 loff_t offset, ssize_t len)
4818{
4819 unsigned int max_blocks;
4820 int ret = 0, ret2 = 0, ret3 = 0;
4821 struct ext4_map_blocks map;
4822 unsigned int blkbits = inode->i_blkbits;
4823 unsigned int credits = 0;
4824
4825 map.m_lblk = offset >> blkbits;
4826 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
4827
4828 if (!handle) {
4829 /*
4830 * credits to insert 1 extent into extent tree
4831 */
4832 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4833 }
4834 while (ret >= 0 && ret < max_blocks) {
4835 map.m_lblk += ret;
4836 map.m_len = (max_blocks -= ret);
4837 if (credits) {
4838 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4839 credits);
4840 if (IS_ERR(handle)) {
4841 ret = PTR_ERR(handle);
4842 break;
4843 }
4844 }
4845 ret = ext4_map_blocks(handle, inode, &map,
4846 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
4847 if (ret <= 0)
4848 ext4_warning(inode->i_sb,
4849 "inode #%lu: block %u: len %u: "
4850 "ext4_ext_map_blocks returned %d",
4851 inode->i_ino, map.m_lblk,
4852 map.m_len, ret);
4853 ret2 = ext4_mark_inode_dirty(handle, inode);
4854 if (credits) {
4855 ret3 = ext4_journal_stop(handle);
4856 if (unlikely(ret3))
4857 ret2 = ret3;
4858 }
4859
4860 if (ret <= 0 || ret2)
4861 break;
4862 }
4863 return ret > 0 ? ret2 : ret;
4864}
4865
4866int ext4_convert_unwritten_io_end_vec(handle_t *handle, ext4_io_end_t *io_end)
4867{
4868 int ret = 0, err = 0;
4869 struct ext4_io_end_vec *io_end_vec;
4870
4871 /*
4872 * This is somewhat ugly but the idea is clear: When transaction is
4873 * reserved, everything goes into it. Otherwise we rather start several
4874 * smaller transactions for conversion of each extent separately.
4875 */
4876 if (handle) {
4877 handle = ext4_journal_start_reserved(handle,
4878 EXT4_HT_EXT_CONVERT);
4879 if (IS_ERR(handle))
4880 return PTR_ERR(handle);
4881 }
4882
4883 list_for_each_entry(io_end_vec, &io_end->list_vec, list) {
4884 ret = ext4_convert_unwritten_extents(handle, io_end->inode,
4885 io_end_vec->offset,
4886 io_end_vec->size);
4887 if (ret)
4888 break;
4889 }
4890
4891 if (handle)
4892 err = ext4_journal_stop(handle);
4893
4894 return ret < 0 ? ret : err;
4895}
4896
4897static int ext4_iomap_xattr_fiemap(struct inode *inode, struct iomap *iomap)
4898{
4899 __u64 physical = 0;
4900 __u64 length = 0;
4901 int blockbits = inode->i_sb->s_blocksize_bits;
4902 int error = 0;
4903 u16 iomap_type;
4904
4905 /* in-inode? */
4906 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
4907 struct ext4_iloc iloc;
4908 int offset; /* offset of xattr in inode */
4909
4910 error = ext4_get_inode_loc(inode, &iloc);
4911 if (error)
4912 return error;
4913 physical = (__u64)iloc.bh->b_blocknr << blockbits;
4914 offset = EXT4_GOOD_OLD_INODE_SIZE +
4915 EXT4_I(inode)->i_extra_isize;
4916 physical += offset;
4917 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
4918 brelse(iloc.bh);
4919 iomap_type = IOMAP_INLINE;
4920 } else if (EXT4_I(inode)->i_file_acl) { /* external block */
4921 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
4922 length = inode->i_sb->s_blocksize;
4923 iomap_type = IOMAP_MAPPED;
4924 } else {
4925 /* no in-inode or external block for xattr, so return -ENOENT */
4926 error = -ENOENT;
4927 goto out;
4928 }
4929
4930 iomap->addr = physical;
4931 iomap->offset = 0;
4932 iomap->length = length;
4933 iomap->type = iomap_type;
4934 iomap->flags = 0;
4935out:
4936 return error;
4937}
4938
4939static int ext4_iomap_xattr_begin(struct inode *inode, loff_t offset,
4940 loff_t length, unsigned flags,
4941 struct iomap *iomap, struct iomap *srcmap)
4942{
4943 int error;
4944
4945 error = ext4_iomap_xattr_fiemap(inode, iomap);
4946 if (error == 0 && (offset >= iomap->length))
4947 error = -ENOENT;
4948 return error;
4949}
4950
4951static const struct iomap_ops ext4_iomap_xattr_ops = {
4952 .iomap_begin = ext4_iomap_xattr_begin,
4953};
4954
4955static int ext4_fiemap_check_ranges(struct inode *inode, u64 start, u64 *len)
4956{
4957 u64 maxbytes;
4958
4959 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
4960 maxbytes = inode->i_sb->s_maxbytes;
4961 else
4962 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
4963
4964 if (*len == 0)
4965 return -EINVAL;
4966 if (start > maxbytes)
4967 return -EFBIG;
4968
4969 /*
4970 * Shrink request scope to what the fs can actually handle.
4971 */
4972 if (*len > maxbytes || (maxbytes - *len) < start)
4973 *len = maxbytes - start;
4974 return 0;
4975}
4976
4977int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4978 u64 start, u64 len)
4979{
4980 int error = 0;
4981
4982 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
4983 error = ext4_ext_precache(inode);
4984 if (error)
4985 return error;
4986 fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
4987 }
4988
4989 /*
4990 * For bitmap files the maximum size limit could be smaller than
4991 * s_maxbytes, so check len here manually instead of just relying on the
4992 * generic check.
4993 */
4994 error = ext4_fiemap_check_ranges(inode, start, &len);
4995 if (error)
4996 return error;
4997
4998 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
4999 fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR;
5000 return iomap_fiemap(inode, fieinfo, start, len,
5001 &ext4_iomap_xattr_ops);
5002 }
5003
5004 return iomap_fiemap(inode, fieinfo, start, len, &ext4_iomap_report_ops);
5005}
5006
5007int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo,
5008 __u64 start, __u64 len)
5009{
5010 ext4_lblk_t start_blk, len_blks;
5011 __u64 last_blk;
5012 int error = 0;
5013
5014 if (ext4_has_inline_data(inode)) {
5015 int has_inline;
5016
5017 down_read(&EXT4_I(inode)->xattr_sem);
5018 has_inline = ext4_has_inline_data(inode);
5019 up_read(&EXT4_I(inode)->xattr_sem);
5020 if (has_inline)
5021 return 0;
5022 }
5023
5024 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
5025 error = ext4_ext_precache(inode);
5026 if (error)
5027 return error;
5028 fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
5029 }
5030
5031 error = fiemap_prep(inode, fieinfo, start, &len, 0);
5032 if (error)
5033 return error;
5034
5035 error = ext4_fiemap_check_ranges(inode, start, &len);
5036 if (error)
5037 return error;
5038
5039 start_blk = start >> inode->i_sb->s_blocksize_bits;
5040 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
5041 if (last_blk >= EXT_MAX_BLOCKS)
5042 last_blk = EXT_MAX_BLOCKS-1;
5043 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
5044
5045 /*
5046 * Walk the extent tree gathering extent information
5047 * and pushing extents back to the user.
5048 */
5049 return ext4_fill_es_cache_info(inode, start_blk, len_blks, fieinfo);
5050}
5051
5052/*
5053 * ext4_ext_shift_path_extents:
5054 * Shift the extents of a path structure lying between path[depth].p_ext
5055 * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
5056 * if it is right shift or left shift operation.
5057 */
5058static int
5059ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
5060 struct inode *inode, handle_t *handle,
5061 enum SHIFT_DIRECTION SHIFT)
5062{
5063 int depth, err = 0;
5064 struct ext4_extent *ex_start, *ex_last;
5065 bool update = false;
5066 int credits, restart_credits;
5067 depth = path->p_depth;
5068
5069 while (depth >= 0) {
5070 if (depth == path->p_depth) {
5071 ex_start = path[depth].p_ext;
5072 if (!ex_start)
5073 return -EFSCORRUPTED;
5074
5075 ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
5076 /* leaf + sb + inode */
5077 credits = 3;
5078 if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) {
5079 update = true;
5080 /* extent tree + sb + inode */
5081 credits = depth + 2;
5082 }
5083
5084 restart_credits = ext4_writepage_trans_blocks(inode);
5085 err = ext4_datasem_ensure_credits(handle, inode, credits,
5086 restart_credits, 0);
5087 if (err) {
5088 if (err > 0)
5089 err = -EAGAIN;
5090 goto out;
5091 }
5092
5093 err = ext4_ext_get_access(handle, inode, path + depth);
5094 if (err)
5095 goto out;
5096
5097 while (ex_start <= ex_last) {
5098 if (SHIFT == SHIFT_LEFT) {
5099 le32_add_cpu(&ex_start->ee_block,
5100 -shift);
5101 /* Try to merge to the left. */
5102 if ((ex_start >
5103 EXT_FIRST_EXTENT(path[depth].p_hdr))
5104 &&
5105 ext4_ext_try_to_merge_right(inode,
5106 path, ex_start - 1))
5107 ex_last--;
5108 else
5109 ex_start++;
5110 } else {
5111 le32_add_cpu(&ex_last->ee_block, shift);
5112 ext4_ext_try_to_merge_right(inode, path,
5113 ex_last);
5114 ex_last--;
5115 }
5116 }
5117 err = ext4_ext_dirty(handle, inode, path + depth);
5118 if (err)
5119 goto out;
5120
5121 if (--depth < 0 || !update)
5122 break;
5123 }
5124
5125 /* Update index too */
5126 err = ext4_ext_get_access(handle, inode, path + depth);
5127 if (err)
5128 goto out;
5129
5130 if (SHIFT == SHIFT_LEFT)
5131 le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
5132 else
5133 le32_add_cpu(&path[depth].p_idx->ei_block, shift);
5134 err = ext4_ext_dirty(handle, inode, path + depth);
5135 if (err)
5136 goto out;
5137
5138 /* we are done if current index is not a starting index */
5139 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
5140 break;
5141
5142 depth--;
5143 }
5144
5145out:
5146 return err;
5147}
5148
5149/*
5150 * ext4_ext_shift_extents:
5151 * All the extents which lies in the range from @start to the last allocated
5152 * block for the @inode are shifted either towards left or right (depending
5153 * upon @SHIFT) by @shift blocks.
5154 * On success, 0 is returned, error otherwise.
5155 */
5156static int
5157ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
5158 ext4_lblk_t start, ext4_lblk_t shift,
5159 enum SHIFT_DIRECTION SHIFT)
5160{
5161 struct ext4_ext_path *path;
5162 int ret = 0, depth;
5163 struct ext4_extent *extent;
5164 ext4_lblk_t stop, *iterator, ex_start, ex_end;
5165 ext4_lblk_t tmp = EXT_MAX_BLOCKS;
5166
5167 /* Let path point to the last extent */
5168 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
5169 EXT4_EX_NOCACHE);
5170 if (IS_ERR(path))
5171 return PTR_ERR(path);
5172
5173 depth = path->p_depth;
5174 extent = path[depth].p_ext;
5175 if (!extent)
5176 goto out;
5177
5178 stop = le32_to_cpu(extent->ee_block);
5179
5180 /*
5181 * For left shifts, make sure the hole on the left is big enough to
5182 * accommodate the shift. For right shifts, make sure the last extent
5183 * won't be shifted beyond EXT_MAX_BLOCKS.
5184 */
5185 if (SHIFT == SHIFT_LEFT) {
5186 path = ext4_find_extent(inode, start - 1, &path,
5187 EXT4_EX_NOCACHE);
5188 if (IS_ERR(path))
5189 return PTR_ERR(path);
5190 depth = path->p_depth;
5191 extent = path[depth].p_ext;
5192 if (extent) {
5193 ex_start = le32_to_cpu(extent->ee_block);
5194 ex_end = le32_to_cpu(extent->ee_block) +
5195 ext4_ext_get_actual_len(extent);
5196 } else {
5197 ex_start = 0;
5198 ex_end = 0;
5199 }
5200
5201 if ((start == ex_start && shift > ex_start) ||
5202 (shift > start - ex_end)) {
5203 ret = -EINVAL;
5204 goto out;
5205 }
5206 } else {
5207 if (shift > EXT_MAX_BLOCKS -
5208 (stop + ext4_ext_get_actual_len(extent))) {
5209 ret = -EINVAL;
5210 goto out;
5211 }
5212 }
5213
5214 /*
5215 * In case of left shift, iterator points to start and it is increased
5216 * till we reach stop. In case of right shift, iterator points to stop
5217 * and it is decreased till we reach start.
5218 */
5219again:
5220 ret = 0;
5221 if (SHIFT == SHIFT_LEFT)
5222 iterator = &start;
5223 else
5224 iterator = &stop;
5225
5226 if (tmp != EXT_MAX_BLOCKS)
5227 *iterator = tmp;
5228
5229 /*
5230 * Its safe to start updating extents. Start and stop are unsigned, so
5231 * in case of right shift if extent with 0 block is reached, iterator
5232 * becomes NULL to indicate the end of the loop.
5233 */
5234 while (iterator && start <= stop) {
5235 path = ext4_find_extent(inode, *iterator, &path,
5236 EXT4_EX_NOCACHE);
5237 if (IS_ERR(path))
5238 return PTR_ERR(path);
5239 depth = path->p_depth;
5240 extent = path[depth].p_ext;
5241 if (!extent) {
5242 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
5243 (unsigned long) *iterator);
5244 return -EFSCORRUPTED;
5245 }
5246 if (SHIFT == SHIFT_LEFT && *iterator >
5247 le32_to_cpu(extent->ee_block)) {
5248 /* Hole, move to the next extent */
5249 if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
5250 path[depth].p_ext++;
5251 } else {
5252 *iterator = ext4_ext_next_allocated_block(path);
5253 continue;
5254 }
5255 }
5256
5257 tmp = *iterator;
5258 if (SHIFT == SHIFT_LEFT) {
5259 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5260 *iterator = le32_to_cpu(extent->ee_block) +
5261 ext4_ext_get_actual_len(extent);
5262 } else {
5263 extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
5264 if (le32_to_cpu(extent->ee_block) > start)
5265 *iterator = le32_to_cpu(extent->ee_block) - 1;
5266 else if (le32_to_cpu(extent->ee_block) == start)
5267 iterator = NULL;
5268 else {
5269 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5270 while (le32_to_cpu(extent->ee_block) >= start)
5271 extent--;
5272
5273 if (extent == EXT_LAST_EXTENT(path[depth].p_hdr))
5274 break;
5275
5276 extent++;
5277 iterator = NULL;
5278 }
5279 path[depth].p_ext = extent;
5280 }
5281 ret = ext4_ext_shift_path_extents(path, shift, inode,
5282 handle, SHIFT);
5283 /* iterator can be NULL which means we should break */
5284 if (ret == -EAGAIN)
5285 goto again;
5286 if (ret)
5287 break;
5288 }
5289out:
5290 ext4_free_ext_path(path);
5291 return ret;
5292}
5293
5294/*
5295 * ext4_collapse_range:
5296 * This implements the fallocate's collapse range functionality for ext4
5297 * Returns: 0 and non-zero on error.
5298 */
5299static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
5300{
5301 struct inode *inode = file_inode(file);
5302 struct super_block *sb = inode->i_sb;
5303 struct address_space *mapping = inode->i_mapping;
5304 ext4_lblk_t punch_start, punch_stop;
5305 handle_t *handle;
5306 unsigned int credits;
5307 loff_t new_size, ioffset;
5308 int ret;
5309
5310 /*
5311 * We need to test this early because xfstests assumes that a
5312 * collapse range of (0, 1) will return EOPNOTSUPP if the file
5313 * system does not support collapse range.
5314 */
5315 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5316 return -EOPNOTSUPP;
5317
5318 /* Collapse range works only on fs cluster size aligned regions. */
5319 if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
5320 return -EINVAL;
5321
5322 trace_ext4_collapse_range(inode, offset, len);
5323
5324 punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5325 punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb);
5326
5327 inode_lock(inode);
5328 /*
5329 * There is no need to overlap collapse range with EOF, in which case
5330 * it is effectively a truncate operation
5331 */
5332 if (offset + len >= inode->i_size) {
5333 ret = -EINVAL;
5334 goto out_mutex;
5335 }
5336
5337 /* Currently just for extent based files */
5338 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5339 ret = -EOPNOTSUPP;
5340 goto out_mutex;
5341 }
5342
5343 /* Wait for existing dio to complete */
5344 inode_dio_wait(inode);
5345
5346 ret = file_modified(file);
5347 if (ret)
5348 goto out_mutex;
5349
5350 /*
5351 * Prevent page faults from reinstantiating pages we have released from
5352 * page cache.
5353 */
5354 filemap_invalidate_lock(mapping);
5355
5356 ret = ext4_break_layouts(inode);
5357 if (ret)
5358 goto out_mmap;
5359
5360 /*
5361 * Need to round down offset to be aligned with page size boundary
5362 * for page size > block size.
5363 */
5364 ioffset = round_down(offset, PAGE_SIZE);
5365 /*
5366 * Write tail of the last page before removed range since it will get
5367 * removed from the page cache below.
5368 */
5369 ret = filemap_write_and_wait_range(mapping, ioffset, offset);
5370 if (ret)
5371 goto out_mmap;
5372 /*
5373 * Write data that will be shifted to preserve them when discarding
5374 * page cache below. We are also protected from pages becoming dirty
5375 * by i_rwsem and invalidate_lock.
5376 */
5377 ret = filemap_write_and_wait_range(mapping, offset + len,
5378 LLONG_MAX);
5379 if (ret)
5380 goto out_mmap;
5381 truncate_pagecache(inode, ioffset);
5382
5383 credits = ext4_writepage_trans_blocks(inode);
5384 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5385 if (IS_ERR(handle)) {
5386 ret = PTR_ERR(handle);
5387 goto out_mmap;
5388 }
5389 ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
5390
5391 down_write(&EXT4_I(inode)->i_data_sem);
5392 ext4_discard_preallocations(inode);
5393 ext4_es_remove_extent(inode, punch_start, EXT_MAX_BLOCKS - punch_start);
5394
5395 ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
5396 if (ret) {
5397 up_write(&EXT4_I(inode)->i_data_sem);
5398 goto out_stop;
5399 }
5400 ext4_discard_preallocations(inode);
5401
5402 ret = ext4_ext_shift_extents(inode, handle, punch_stop,
5403 punch_stop - punch_start, SHIFT_LEFT);
5404 if (ret) {
5405 up_write(&EXT4_I(inode)->i_data_sem);
5406 goto out_stop;
5407 }
5408
5409 new_size = inode->i_size - len;
5410 i_size_write(inode, new_size);
5411 EXT4_I(inode)->i_disksize = new_size;
5412
5413 up_write(&EXT4_I(inode)->i_data_sem);
5414 if (IS_SYNC(inode))
5415 ext4_handle_sync(handle);
5416 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
5417 ret = ext4_mark_inode_dirty(handle, inode);
5418 ext4_update_inode_fsync_trans(handle, inode, 1);
5419
5420out_stop:
5421 ext4_journal_stop(handle);
5422out_mmap:
5423 filemap_invalidate_unlock(mapping);
5424out_mutex:
5425 inode_unlock(inode);
5426 return ret;
5427}
5428
5429/*
5430 * ext4_insert_range:
5431 * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
5432 * The data blocks starting from @offset to the EOF are shifted by @len
5433 * towards right to create a hole in the @inode. Inode size is increased
5434 * by len bytes.
5435 * Returns 0 on success, error otherwise.
5436 */
5437static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
5438{
5439 struct inode *inode = file_inode(file);
5440 struct super_block *sb = inode->i_sb;
5441 struct address_space *mapping = inode->i_mapping;
5442 handle_t *handle;
5443 struct ext4_ext_path *path;
5444 struct ext4_extent *extent;
5445 ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
5446 unsigned int credits, ee_len;
5447 int ret = 0, depth, split_flag = 0;
5448 loff_t ioffset;
5449
5450 /*
5451 * We need to test this early because xfstests assumes that an
5452 * insert range of (0, 1) will return EOPNOTSUPP if the file
5453 * system does not support insert range.
5454 */
5455 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5456 return -EOPNOTSUPP;
5457
5458 /* Insert range works only on fs cluster size aligned regions. */
5459 if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
5460 return -EINVAL;
5461
5462 trace_ext4_insert_range(inode, offset, len);
5463
5464 offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5465 len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
5466
5467 inode_lock(inode);
5468 /* Currently just for extent based files */
5469 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5470 ret = -EOPNOTSUPP;
5471 goto out_mutex;
5472 }
5473
5474 /* Check whether the maximum file size would be exceeded */
5475 if (len > inode->i_sb->s_maxbytes - inode->i_size) {
5476 ret = -EFBIG;
5477 goto out_mutex;
5478 }
5479
5480 /* Offset must be less than i_size */
5481 if (offset >= inode->i_size) {
5482 ret = -EINVAL;
5483 goto out_mutex;
5484 }
5485
5486 /* Wait for existing dio to complete */
5487 inode_dio_wait(inode);
5488
5489 ret = file_modified(file);
5490 if (ret)
5491 goto out_mutex;
5492
5493 /*
5494 * Prevent page faults from reinstantiating pages we have released from
5495 * page cache.
5496 */
5497 filemap_invalidate_lock(mapping);
5498
5499 ret = ext4_break_layouts(inode);
5500 if (ret)
5501 goto out_mmap;
5502
5503 /*
5504 * Need to round down to align start offset to page size boundary
5505 * for page size > block size.
5506 */
5507 ioffset = round_down(offset, PAGE_SIZE);
5508 /* Write out all dirty pages */
5509 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5510 LLONG_MAX);
5511 if (ret)
5512 goto out_mmap;
5513 truncate_pagecache(inode, ioffset);
5514
5515 credits = ext4_writepage_trans_blocks(inode);
5516 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5517 if (IS_ERR(handle)) {
5518 ret = PTR_ERR(handle);
5519 goto out_mmap;
5520 }
5521 ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
5522
5523 /* Expand file to avoid data loss if there is error while shifting */
5524 inode->i_size += len;
5525 EXT4_I(inode)->i_disksize += len;
5526 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
5527 ret = ext4_mark_inode_dirty(handle, inode);
5528 if (ret)
5529 goto out_stop;
5530
5531 down_write(&EXT4_I(inode)->i_data_sem);
5532 ext4_discard_preallocations(inode);
5533
5534 path = ext4_find_extent(inode, offset_lblk, NULL, 0);
5535 if (IS_ERR(path)) {
5536 up_write(&EXT4_I(inode)->i_data_sem);
5537 goto out_stop;
5538 }
5539
5540 depth = ext_depth(inode);
5541 extent = path[depth].p_ext;
5542 if (extent) {
5543 ee_start_lblk = le32_to_cpu(extent->ee_block);
5544 ee_len = ext4_ext_get_actual_len(extent);
5545
5546 /*
5547 * If offset_lblk is not the starting block of extent, split
5548 * the extent @offset_lblk
5549 */
5550 if ((offset_lblk > ee_start_lblk) &&
5551 (offset_lblk < (ee_start_lblk + ee_len))) {
5552 if (ext4_ext_is_unwritten(extent))
5553 split_flag = EXT4_EXT_MARK_UNWRIT1 |
5554 EXT4_EXT_MARK_UNWRIT2;
5555 ret = ext4_split_extent_at(handle, inode, &path,
5556 offset_lblk, split_flag,
5557 EXT4_EX_NOCACHE |
5558 EXT4_GET_BLOCKS_PRE_IO |
5559 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5560 }
5561
5562 ext4_free_ext_path(path);
5563 if (ret < 0) {
5564 up_write(&EXT4_I(inode)->i_data_sem);
5565 goto out_stop;
5566 }
5567 } else {
5568 ext4_free_ext_path(path);
5569 }
5570
5571 ext4_es_remove_extent(inode, offset_lblk, EXT_MAX_BLOCKS - offset_lblk);
5572
5573 /*
5574 * if offset_lblk lies in a hole which is at start of file, use
5575 * ee_start_lblk to shift extents
5576 */
5577 ret = ext4_ext_shift_extents(inode, handle,
5578 max(ee_start_lblk, offset_lblk), len_lblk, SHIFT_RIGHT);
5579
5580 up_write(&EXT4_I(inode)->i_data_sem);
5581 if (IS_SYNC(inode))
5582 ext4_handle_sync(handle);
5583 if (ret >= 0)
5584 ext4_update_inode_fsync_trans(handle, inode, 1);
5585
5586out_stop:
5587 ext4_journal_stop(handle);
5588out_mmap:
5589 filemap_invalidate_unlock(mapping);
5590out_mutex:
5591 inode_unlock(inode);
5592 return ret;
5593}
5594
5595/**
5596 * ext4_swap_extents() - Swap extents between two inodes
5597 * @handle: handle for this transaction
5598 * @inode1: First inode
5599 * @inode2: Second inode
5600 * @lblk1: Start block for first inode
5601 * @lblk2: Start block for second inode
5602 * @count: Number of blocks to swap
5603 * @unwritten: Mark second inode's extents as unwritten after swap
5604 * @erp: Pointer to save error value
5605 *
5606 * This helper routine does exactly what is promise "swap extents". All other
5607 * stuff such as page-cache locking consistency, bh mapping consistency or
5608 * extent's data copying must be performed by caller.
5609 * Locking:
5610 * i_rwsem is held for both inodes
5611 * i_data_sem is locked for write for both inodes
5612 * Assumptions:
5613 * All pages from requested range are locked for both inodes
5614 */
5615int
5616ext4_swap_extents(handle_t *handle, struct inode *inode1,
5617 struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
5618 ext4_lblk_t count, int unwritten, int *erp)
5619{
5620 struct ext4_ext_path *path1 = NULL;
5621 struct ext4_ext_path *path2 = NULL;
5622 int replaced_count = 0;
5623
5624 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
5625 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
5626 BUG_ON(!inode_is_locked(inode1));
5627 BUG_ON(!inode_is_locked(inode2));
5628
5629 ext4_es_remove_extent(inode1, lblk1, count);
5630 ext4_es_remove_extent(inode2, lblk2, count);
5631
5632 while (count) {
5633 struct ext4_extent *ex1, *ex2, tmp_ex;
5634 ext4_lblk_t e1_blk, e2_blk;
5635 int e1_len, e2_len, len;
5636 int split = 0;
5637
5638 path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE);
5639 if (IS_ERR(path1)) {
5640 *erp = PTR_ERR(path1);
5641 path1 = NULL;
5642 finish:
5643 count = 0;
5644 goto repeat;
5645 }
5646 path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE);
5647 if (IS_ERR(path2)) {
5648 *erp = PTR_ERR(path2);
5649 path2 = NULL;
5650 goto finish;
5651 }
5652 ex1 = path1[path1->p_depth].p_ext;
5653 ex2 = path2[path2->p_depth].p_ext;
5654 /* Do we have something to swap ? */
5655 if (unlikely(!ex2 || !ex1))
5656 goto finish;
5657
5658 e1_blk = le32_to_cpu(ex1->ee_block);
5659 e2_blk = le32_to_cpu(ex2->ee_block);
5660 e1_len = ext4_ext_get_actual_len(ex1);
5661 e2_len = ext4_ext_get_actual_len(ex2);
5662
5663 /* Hole handling */
5664 if (!in_range(lblk1, e1_blk, e1_len) ||
5665 !in_range(lblk2, e2_blk, e2_len)) {
5666 ext4_lblk_t next1, next2;
5667
5668 /* if hole after extent, then go to next extent */
5669 next1 = ext4_ext_next_allocated_block(path1);
5670 next2 = ext4_ext_next_allocated_block(path2);
5671 /* If hole before extent, then shift to that extent */
5672 if (e1_blk > lblk1)
5673 next1 = e1_blk;
5674 if (e2_blk > lblk2)
5675 next2 = e2_blk;
5676 /* Do we have something to swap */
5677 if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
5678 goto finish;
5679 /* Move to the rightest boundary */
5680 len = next1 - lblk1;
5681 if (len < next2 - lblk2)
5682 len = next2 - lblk2;
5683 if (len > count)
5684 len = count;
5685 lblk1 += len;
5686 lblk2 += len;
5687 count -= len;
5688 goto repeat;
5689 }
5690
5691 /* Prepare left boundary */
5692 if (e1_blk < lblk1) {
5693 split = 1;
5694 *erp = ext4_force_split_extent_at(handle, inode1,
5695 &path1, lblk1, 0);
5696 if (unlikely(*erp))
5697 goto finish;
5698 }
5699 if (e2_blk < lblk2) {
5700 split = 1;
5701 *erp = ext4_force_split_extent_at(handle, inode2,
5702 &path2, lblk2, 0);
5703 if (unlikely(*erp))
5704 goto finish;
5705 }
5706 /* ext4_split_extent_at() may result in leaf extent split,
5707 * path must to be revalidated. */
5708 if (split)
5709 goto repeat;
5710
5711 /* Prepare right boundary */
5712 len = count;
5713 if (len > e1_blk + e1_len - lblk1)
5714 len = e1_blk + e1_len - lblk1;
5715 if (len > e2_blk + e2_len - lblk2)
5716 len = e2_blk + e2_len - lblk2;
5717
5718 if (len != e1_len) {
5719 split = 1;
5720 *erp = ext4_force_split_extent_at(handle, inode1,
5721 &path1, lblk1 + len, 0);
5722 if (unlikely(*erp))
5723 goto finish;
5724 }
5725 if (len != e2_len) {
5726 split = 1;
5727 *erp = ext4_force_split_extent_at(handle, inode2,
5728 &path2, lblk2 + len, 0);
5729 if (*erp)
5730 goto finish;
5731 }
5732 /* ext4_split_extent_at() may result in leaf extent split,
5733 * path must to be revalidated. */
5734 if (split)
5735 goto repeat;
5736
5737 BUG_ON(e2_len != e1_len);
5738 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
5739 if (unlikely(*erp))
5740 goto finish;
5741 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
5742 if (unlikely(*erp))
5743 goto finish;
5744
5745 /* Both extents are fully inside boundaries. Swap it now */
5746 tmp_ex = *ex1;
5747 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
5748 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
5749 ex1->ee_len = cpu_to_le16(e2_len);
5750 ex2->ee_len = cpu_to_le16(e1_len);
5751 if (unwritten)
5752 ext4_ext_mark_unwritten(ex2);
5753 if (ext4_ext_is_unwritten(&tmp_ex))
5754 ext4_ext_mark_unwritten(ex1);
5755
5756 ext4_ext_try_to_merge(handle, inode2, path2, ex2);
5757 ext4_ext_try_to_merge(handle, inode1, path1, ex1);
5758 *erp = ext4_ext_dirty(handle, inode2, path2 +
5759 path2->p_depth);
5760 if (unlikely(*erp))
5761 goto finish;
5762 *erp = ext4_ext_dirty(handle, inode1, path1 +
5763 path1->p_depth);
5764 /*
5765 * Looks scarry ah..? second inode already points to new blocks,
5766 * and it was successfully dirtied. But luckily error may happen
5767 * only due to journal error, so full transaction will be
5768 * aborted anyway.
5769 */
5770 if (unlikely(*erp))
5771 goto finish;
5772 lblk1 += len;
5773 lblk2 += len;
5774 replaced_count += len;
5775 count -= len;
5776
5777 repeat:
5778 ext4_free_ext_path(path1);
5779 ext4_free_ext_path(path2);
5780 path1 = path2 = NULL;
5781 }
5782 return replaced_count;
5783}
5784
5785/*
5786 * ext4_clu_mapped - determine whether any block in a logical cluster has
5787 * been mapped to a physical cluster
5788 *
5789 * @inode - file containing the logical cluster
5790 * @lclu - logical cluster of interest
5791 *
5792 * Returns 1 if any block in the logical cluster is mapped, signifying
5793 * that a physical cluster has been allocated for it. Otherwise,
5794 * returns 0. Can also return negative error codes. Derived from
5795 * ext4_ext_map_blocks().
5796 */
5797int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu)
5798{
5799 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5800 struct ext4_ext_path *path;
5801 int depth, mapped = 0, err = 0;
5802 struct ext4_extent *extent;
5803 ext4_lblk_t first_lblk, first_lclu, last_lclu;
5804
5805 /*
5806 * if data can be stored inline, the logical cluster isn't
5807 * mapped - no physical clusters have been allocated, and the
5808 * file has no extents
5809 */
5810 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) ||
5811 ext4_has_inline_data(inode))
5812 return 0;
5813
5814 /* search for the extent closest to the first block in the cluster */
5815 path = ext4_find_extent(inode, EXT4_C2B(sbi, lclu), NULL, 0);
5816 if (IS_ERR(path)) {
5817 err = PTR_ERR(path);
5818 path = NULL;
5819 goto out;
5820 }
5821
5822 depth = ext_depth(inode);
5823
5824 /*
5825 * A consistent leaf must not be empty. This situation is possible,
5826 * though, _during_ tree modification, and it's why an assert can't
5827 * be put in ext4_find_extent().
5828 */
5829 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
5830 EXT4_ERROR_INODE(inode,
5831 "bad extent address - lblock: %lu, depth: %d, pblock: %lld",
5832 (unsigned long) EXT4_C2B(sbi, lclu),
5833 depth, path[depth].p_block);
5834 err = -EFSCORRUPTED;
5835 goto out;
5836 }
5837
5838 extent = path[depth].p_ext;
5839
5840 /* can't be mapped if the extent tree is empty */
5841 if (extent == NULL)
5842 goto out;
5843
5844 first_lblk = le32_to_cpu(extent->ee_block);
5845 first_lclu = EXT4_B2C(sbi, first_lblk);
5846
5847 /*
5848 * Three possible outcomes at this point - found extent spanning
5849 * the target cluster, to the left of the target cluster, or to the
5850 * right of the target cluster. The first two cases are handled here.
5851 * The last case indicates the target cluster is not mapped.
5852 */
5853 if (lclu >= first_lclu) {
5854 last_lclu = EXT4_B2C(sbi, first_lblk +
5855 ext4_ext_get_actual_len(extent) - 1);
5856 if (lclu <= last_lclu) {
5857 mapped = 1;
5858 } else {
5859 first_lblk = ext4_ext_next_allocated_block(path);
5860 first_lclu = EXT4_B2C(sbi, first_lblk);
5861 if (lclu == first_lclu)
5862 mapped = 1;
5863 }
5864 }
5865
5866out:
5867 ext4_free_ext_path(path);
5868
5869 return err ? err : mapped;
5870}
5871
5872/*
5873 * Updates physical block address and unwritten status of extent
5874 * starting at lblk start and of len. If such an extent doesn't exist,
5875 * this function splits the extent tree appropriately to create an
5876 * extent like this. This function is called in the fast commit
5877 * replay path. Returns 0 on success and error on failure.
5878 */
5879int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start,
5880 int len, int unwritten, ext4_fsblk_t pblk)
5881{
5882 struct ext4_ext_path *path = NULL, *ppath;
5883 struct ext4_extent *ex;
5884 int ret;
5885
5886 path = ext4_find_extent(inode, start, NULL, 0);
5887 if (IS_ERR(path))
5888 return PTR_ERR(path);
5889 ex = path[path->p_depth].p_ext;
5890 if (!ex) {
5891 ret = -EFSCORRUPTED;
5892 goto out;
5893 }
5894
5895 if (le32_to_cpu(ex->ee_block) != start ||
5896 ext4_ext_get_actual_len(ex) != len) {
5897 /* We need to split this extent to match our extent first */
5898 ppath = path;
5899 down_write(&EXT4_I(inode)->i_data_sem);
5900 ret = ext4_force_split_extent_at(NULL, inode, &ppath, start, 1);
5901 up_write(&EXT4_I(inode)->i_data_sem);
5902 if (ret)
5903 goto out;
5904 kfree(path);
5905 path = ext4_find_extent(inode, start, NULL, 0);
5906 if (IS_ERR(path))
5907 return -1;
5908 ppath = path;
5909 ex = path[path->p_depth].p_ext;
5910 WARN_ON(le32_to_cpu(ex->ee_block) != start);
5911 if (ext4_ext_get_actual_len(ex) != len) {
5912 down_write(&EXT4_I(inode)->i_data_sem);
5913 ret = ext4_force_split_extent_at(NULL, inode, &ppath,
5914 start + len, 1);
5915 up_write(&EXT4_I(inode)->i_data_sem);
5916 if (ret)
5917 goto out;
5918 kfree(path);
5919 path = ext4_find_extent(inode, start, NULL, 0);
5920 if (IS_ERR(path))
5921 return -EINVAL;
5922 ex = path[path->p_depth].p_ext;
5923 }
5924 }
5925 if (unwritten)
5926 ext4_ext_mark_unwritten(ex);
5927 else
5928 ext4_ext_mark_initialized(ex);
5929 ext4_ext_store_pblock(ex, pblk);
5930 down_write(&EXT4_I(inode)->i_data_sem);
5931 ret = ext4_ext_dirty(NULL, inode, &path[path->p_depth]);
5932 up_write(&EXT4_I(inode)->i_data_sem);
5933out:
5934 ext4_free_ext_path(path);
5935 ext4_mark_inode_dirty(NULL, inode);
5936 return ret;
5937}
5938
5939/* Try to shrink the extent tree */
5940void ext4_ext_replay_shrink_inode(struct inode *inode, ext4_lblk_t end)
5941{
5942 struct ext4_ext_path *path = NULL;
5943 struct ext4_extent *ex;
5944 ext4_lblk_t old_cur, cur = 0;
5945
5946 while (cur < end) {
5947 path = ext4_find_extent(inode, cur, NULL, 0);
5948 if (IS_ERR(path))
5949 return;
5950 ex = path[path->p_depth].p_ext;
5951 if (!ex) {
5952 ext4_free_ext_path(path);
5953 ext4_mark_inode_dirty(NULL, inode);
5954 return;
5955 }
5956 old_cur = cur;
5957 cur = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
5958 if (cur <= old_cur)
5959 cur = old_cur + 1;
5960 ext4_ext_try_to_merge(NULL, inode, path, ex);
5961 down_write(&EXT4_I(inode)->i_data_sem);
5962 ext4_ext_dirty(NULL, inode, &path[path->p_depth]);
5963 up_write(&EXT4_I(inode)->i_data_sem);
5964 ext4_mark_inode_dirty(NULL, inode);
5965 ext4_free_ext_path(path);
5966 }
5967}
5968
5969/* Check if *cur is a hole and if it is, skip it */
5970static int skip_hole(struct inode *inode, ext4_lblk_t *cur)
5971{
5972 int ret;
5973 struct ext4_map_blocks map;
5974
5975 map.m_lblk = *cur;
5976 map.m_len = ((inode->i_size) >> inode->i_sb->s_blocksize_bits) - *cur;
5977
5978 ret = ext4_map_blocks(NULL, inode, &map, 0);
5979 if (ret < 0)
5980 return ret;
5981 if (ret != 0)
5982 return 0;
5983 *cur = *cur + map.m_len;
5984 return 0;
5985}
5986
5987/* Count number of blocks used by this inode and update i_blocks */
5988int ext4_ext_replay_set_iblocks(struct inode *inode)
5989{
5990 struct ext4_ext_path *path = NULL, *path2 = NULL;
5991 struct ext4_extent *ex;
5992 ext4_lblk_t cur = 0, end;
5993 int numblks = 0, i, ret = 0;
5994 ext4_fsblk_t cmp1, cmp2;
5995 struct ext4_map_blocks map;
5996
5997 /* Determin the size of the file first */
5998 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
5999 EXT4_EX_NOCACHE);
6000 if (IS_ERR(path))
6001 return PTR_ERR(path);
6002 ex = path[path->p_depth].p_ext;
6003 if (!ex) {
6004 ext4_free_ext_path(path);
6005 goto out;
6006 }
6007 end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
6008 ext4_free_ext_path(path);
6009
6010 /* Count the number of data blocks */
6011 cur = 0;
6012 while (cur < end) {
6013 map.m_lblk = cur;
6014 map.m_len = end - cur;
6015 ret = ext4_map_blocks(NULL, inode, &map, 0);
6016 if (ret < 0)
6017 break;
6018 if (ret > 0)
6019 numblks += ret;
6020 cur = cur + map.m_len;
6021 }
6022
6023 /*
6024 * Count the number of extent tree blocks. We do it by looking up
6025 * two successive extents and determining the difference between
6026 * their paths. When path is different for 2 successive extents
6027 * we compare the blocks in the path at each level and increment
6028 * iblocks by total number of differences found.
6029 */
6030 cur = 0;
6031 ret = skip_hole(inode, &cur);
6032 if (ret < 0)
6033 goto out;
6034 path = ext4_find_extent(inode, cur, NULL, 0);
6035 if (IS_ERR(path))
6036 goto out;
6037 numblks += path->p_depth;
6038 ext4_free_ext_path(path);
6039 while (cur < end) {
6040 path = ext4_find_extent(inode, cur, NULL, 0);
6041 if (IS_ERR(path))
6042 break;
6043 ex = path[path->p_depth].p_ext;
6044 if (!ex) {
6045 ext4_free_ext_path(path);
6046 return 0;
6047 }
6048 cur = max(cur + 1, le32_to_cpu(ex->ee_block) +
6049 ext4_ext_get_actual_len(ex));
6050 ret = skip_hole(inode, &cur);
6051 if (ret < 0) {
6052 ext4_free_ext_path(path);
6053 break;
6054 }
6055 path2 = ext4_find_extent(inode, cur, NULL, 0);
6056 if (IS_ERR(path2)) {
6057 ext4_free_ext_path(path);
6058 break;
6059 }
6060 for (i = 0; i <= max(path->p_depth, path2->p_depth); i++) {
6061 cmp1 = cmp2 = 0;
6062 if (i <= path->p_depth)
6063 cmp1 = path[i].p_bh ?
6064 path[i].p_bh->b_blocknr : 0;
6065 if (i <= path2->p_depth)
6066 cmp2 = path2[i].p_bh ?
6067 path2[i].p_bh->b_blocknr : 0;
6068 if (cmp1 != cmp2 && cmp2 != 0)
6069 numblks++;
6070 }
6071 ext4_free_ext_path(path);
6072 ext4_free_ext_path(path2);
6073 }
6074
6075out:
6076 inode->i_blocks = numblks << (inode->i_sb->s_blocksize_bits - 9);
6077 ext4_mark_inode_dirty(NULL, inode);
6078 return 0;
6079}
6080
6081int ext4_ext_clear_bb(struct inode *inode)
6082{
6083 struct ext4_ext_path *path = NULL;
6084 struct ext4_extent *ex;
6085 ext4_lblk_t cur = 0, end;
6086 int j, ret = 0;
6087 struct ext4_map_blocks map;
6088
6089 if (ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA))
6090 return 0;
6091
6092 /* Determin the size of the file first */
6093 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
6094 EXT4_EX_NOCACHE);
6095 if (IS_ERR(path))
6096 return PTR_ERR(path);
6097 ex = path[path->p_depth].p_ext;
6098 if (!ex) {
6099 ext4_free_ext_path(path);
6100 return 0;
6101 }
6102 end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
6103 ext4_free_ext_path(path);
6104
6105 cur = 0;
6106 while (cur < end) {
6107 map.m_lblk = cur;
6108 map.m_len = end - cur;
6109 ret = ext4_map_blocks(NULL, inode, &map, 0);
6110 if (ret < 0)
6111 break;
6112 if (ret > 0) {
6113 path = ext4_find_extent(inode, map.m_lblk, NULL, 0);
6114 if (!IS_ERR_OR_NULL(path)) {
6115 for (j = 0; j < path->p_depth; j++) {
6116
6117 ext4_mb_mark_bb(inode->i_sb,
6118 path[j].p_block, 1, false);
6119 ext4_fc_record_regions(inode->i_sb, inode->i_ino,
6120 0, path[j].p_block, 1, 1);
6121 }
6122 ext4_free_ext_path(path);
6123 }
6124 ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, false);
6125 ext4_fc_record_regions(inode->i_sb, inode->i_ino,
6126 map.m_lblk, map.m_pblk, map.m_len, 1);
6127 }
6128 cur = cur + map.m_len;
6129 }
6130
6131 return 0;
6132}