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1/*
2 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
3 * Written by Alex Tomas <alex@clusterfs.com>
4 *
5 * Architecture independence:
6 * Copyright (c) 2005, Bull S.A.
7 * Written by Pierre Peiffer <pierre.peiffer@bull.net>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
21 */
22
23/*
24 * Extents support for EXT4
25 *
26 * TODO:
27 * - ext4*_error() should be used in some situations
28 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
29 * - smart tree reduction
30 */
31
32#include <linux/fs.h>
33#include <linux/time.h>
34#include <linux/jbd2.h>
35#include <linux/highuid.h>
36#include <linux/pagemap.h>
37#include <linux/quotaops.h>
38#include <linux/string.h>
39#include <linux/slab.h>
40#include <asm/uaccess.h>
41#include <linux/fiemap.h>
42#include <linux/backing-dev.h>
43#include "ext4_jbd2.h"
44#include "ext4_extents.h"
45#include "xattr.h"
46
47#include <trace/events/ext4.h>
48
49/*
50 * used by extent splitting.
51 */
52#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
53 due to ENOSPC */
54#define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */
55#define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */
56
57#define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
58#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
59
60static __le32 ext4_extent_block_csum(struct inode *inode,
61 struct ext4_extent_header *eh)
62{
63 struct ext4_inode_info *ei = EXT4_I(inode);
64 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
65 __u32 csum;
66
67 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
68 EXT4_EXTENT_TAIL_OFFSET(eh));
69 return cpu_to_le32(csum);
70}
71
72static int ext4_extent_block_csum_verify(struct inode *inode,
73 struct ext4_extent_header *eh)
74{
75 struct ext4_extent_tail *et;
76
77 if (!ext4_has_metadata_csum(inode->i_sb))
78 return 1;
79
80 et = find_ext4_extent_tail(eh);
81 if (et->et_checksum != ext4_extent_block_csum(inode, eh))
82 return 0;
83 return 1;
84}
85
86static void ext4_extent_block_csum_set(struct inode *inode,
87 struct ext4_extent_header *eh)
88{
89 struct ext4_extent_tail *et;
90
91 if (!ext4_has_metadata_csum(inode->i_sb))
92 return;
93
94 et = find_ext4_extent_tail(eh);
95 et->et_checksum = ext4_extent_block_csum(inode, eh);
96}
97
98static int ext4_split_extent(handle_t *handle,
99 struct inode *inode,
100 struct ext4_ext_path **ppath,
101 struct ext4_map_blocks *map,
102 int split_flag,
103 int flags);
104
105static int ext4_split_extent_at(handle_t *handle,
106 struct inode *inode,
107 struct ext4_ext_path **ppath,
108 ext4_lblk_t split,
109 int split_flag,
110 int flags);
111
112static int ext4_find_delayed_extent(struct inode *inode,
113 struct extent_status *newes);
114
115static int ext4_ext_truncate_extend_restart(handle_t *handle,
116 struct inode *inode,
117 int needed)
118{
119 int err;
120
121 if (!ext4_handle_valid(handle))
122 return 0;
123 if (handle->h_buffer_credits > needed)
124 return 0;
125 err = ext4_journal_extend(handle, needed);
126 if (err <= 0)
127 return err;
128 err = ext4_truncate_restart_trans(handle, inode, needed);
129 if (err == 0)
130 err = -EAGAIN;
131
132 return err;
133}
134
135/*
136 * could return:
137 * - EROFS
138 * - ENOMEM
139 */
140static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
141 struct ext4_ext_path *path)
142{
143 if (path->p_bh) {
144 /* path points to block */
145 BUFFER_TRACE(path->p_bh, "get_write_access");
146 return ext4_journal_get_write_access(handle, path->p_bh);
147 }
148 /* path points to leaf/index in inode body */
149 /* we use in-core data, no need to protect them */
150 return 0;
151}
152
153/*
154 * could return:
155 * - EROFS
156 * - ENOMEM
157 * - EIO
158 */
159int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle,
160 struct inode *inode, struct ext4_ext_path *path)
161{
162 int err;
163
164 WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
165 if (path->p_bh) {
166 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
167 /* path points to block */
168 err = __ext4_handle_dirty_metadata(where, line, handle,
169 inode, path->p_bh);
170 } else {
171 /* path points to leaf/index in inode body */
172 err = ext4_mark_inode_dirty(handle, inode);
173 }
174 return err;
175}
176
177static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
178 struct ext4_ext_path *path,
179 ext4_lblk_t block)
180{
181 if (path) {
182 int depth = path->p_depth;
183 struct ext4_extent *ex;
184
185 /*
186 * Try to predict block placement assuming that we are
187 * filling in a file which will eventually be
188 * non-sparse --- i.e., in the case of libbfd writing
189 * an ELF object sections out-of-order but in a way
190 * the eventually results in a contiguous object or
191 * executable file, or some database extending a table
192 * space file. However, this is actually somewhat
193 * non-ideal if we are writing a sparse file such as
194 * qemu or KVM writing a raw image file that is going
195 * to stay fairly sparse, since it will end up
196 * fragmenting the file system's free space. Maybe we
197 * should have some hueristics or some way to allow
198 * userspace to pass a hint to file system,
199 * especially if the latter case turns out to be
200 * common.
201 */
202 ex = path[depth].p_ext;
203 if (ex) {
204 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
205 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
206
207 if (block > ext_block)
208 return ext_pblk + (block - ext_block);
209 else
210 return ext_pblk - (ext_block - block);
211 }
212
213 /* it looks like index is empty;
214 * try to find starting block from index itself */
215 if (path[depth].p_bh)
216 return path[depth].p_bh->b_blocknr;
217 }
218
219 /* OK. use inode's group */
220 return ext4_inode_to_goal_block(inode);
221}
222
223/*
224 * Allocation for a meta data block
225 */
226static ext4_fsblk_t
227ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
228 struct ext4_ext_path *path,
229 struct ext4_extent *ex, int *err, unsigned int flags)
230{
231 ext4_fsblk_t goal, newblock;
232
233 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
234 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
235 NULL, err);
236 return newblock;
237}
238
239static inline int ext4_ext_space_block(struct inode *inode, int check)
240{
241 int size;
242
243 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
244 / sizeof(struct ext4_extent);
245#ifdef AGGRESSIVE_TEST
246 if (!check && size > 6)
247 size = 6;
248#endif
249 return size;
250}
251
252static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
253{
254 int size;
255
256 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
257 / sizeof(struct ext4_extent_idx);
258#ifdef AGGRESSIVE_TEST
259 if (!check && size > 5)
260 size = 5;
261#endif
262 return size;
263}
264
265static inline int ext4_ext_space_root(struct inode *inode, int check)
266{
267 int size;
268
269 size = sizeof(EXT4_I(inode)->i_data);
270 size -= sizeof(struct ext4_extent_header);
271 size /= sizeof(struct ext4_extent);
272#ifdef AGGRESSIVE_TEST
273 if (!check && size > 3)
274 size = 3;
275#endif
276 return size;
277}
278
279static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
280{
281 int size;
282
283 size = sizeof(EXT4_I(inode)->i_data);
284 size -= sizeof(struct ext4_extent_header);
285 size /= sizeof(struct ext4_extent_idx);
286#ifdef AGGRESSIVE_TEST
287 if (!check && size > 4)
288 size = 4;
289#endif
290 return size;
291}
292
293static inline int
294ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
295 struct ext4_ext_path **ppath, ext4_lblk_t lblk,
296 int nofail)
297{
298 struct ext4_ext_path *path = *ppath;
299 int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
300
301 return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ?
302 EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
303 EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO |
304 (nofail ? EXT4_GET_BLOCKS_METADATA_NOFAIL:0));
305}
306
307/*
308 * Calculate the number of metadata blocks needed
309 * to allocate @blocks
310 * Worse case is one block per extent
311 */
312int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
313{
314 struct ext4_inode_info *ei = EXT4_I(inode);
315 int idxs;
316
317 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
318 / sizeof(struct ext4_extent_idx));
319
320 /*
321 * If the new delayed allocation block is contiguous with the
322 * previous da block, it can share index blocks with the
323 * previous block, so we only need to allocate a new index
324 * block every idxs leaf blocks. At ldxs**2 blocks, we need
325 * an additional index block, and at ldxs**3 blocks, yet
326 * another index blocks.
327 */
328 if (ei->i_da_metadata_calc_len &&
329 ei->i_da_metadata_calc_last_lblock+1 == lblock) {
330 int num = 0;
331
332 if ((ei->i_da_metadata_calc_len % idxs) == 0)
333 num++;
334 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
335 num++;
336 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
337 num++;
338 ei->i_da_metadata_calc_len = 0;
339 } else
340 ei->i_da_metadata_calc_len++;
341 ei->i_da_metadata_calc_last_lblock++;
342 return num;
343 }
344
345 /*
346 * In the worst case we need a new set of index blocks at
347 * every level of the inode's extent tree.
348 */
349 ei->i_da_metadata_calc_len = 1;
350 ei->i_da_metadata_calc_last_lblock = lblock;
351 return ext_depth(inode) + 1;
352}
353
354static int
355ext4_ext_max_entries(struct inode *inode, int depth)
356{
357 int max;
358
359 if (depth == ext_depth(inode)) {
360 if (depth == 0)
361 max = ext4_ext_space_root(inode, 1);
362 else
363 max = ext4_ext_space_root_idx(inode, 1);
364 } else {
365 if (depth == 0)
366 max = ext4_ext_space_block(inode, 1);
367 else
368 max = ext4_ext_space_block_idx(inode, 1);
369 }
370
371 return max;
372}
373
374static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
375{
376 ext4_fsblk_t block = ext4_ext_pblock(ext);
377 int len = ext4_ext_get_actual_len(ext);
378 ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
379 ext4_lblk_t last = lblock + len - 1;
380
381 if (len == 0 || lblock > last)
382 return 0;
383 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
384}
385
386static int ext4_valid_extent_idx(struct inode *inode,
387 struct ext4_extent_idx *ext_idx)
388{
389 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
390
391 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
392}
393
394static int ext4_valid_extent_entries(struct inode *inode,
395 struct ext4_extent_header *eh,
396 int depth)
397{
398 unsigned short entries;
399 if (eh->eh_entries == 0)
400 return 1;
401
402 entries = le16_to_cpu(eh->eh_entries);
403
404 if (depth == 0) {
405 /* leaf entries */
406 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
407 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
408 ext4_fsblk_t pblock = 0;
409 ext4_lblk_t lblock = 0;
410 ext4_lblk_t prev = 0;
411 int len = 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 len = ext4_ext_get_actual_len(ext);
419 if ((lblock <= prev) && prev) {
420 pblock = ext4_ext_pblock(ext);
421 es->s_last_error_block = cpu_to_le64(pblock);
422 return 0;
423 }
424 ext++;
425 entries--;
426 prev = lblock + len - 1;
427 }
428 } else {
429 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
430 while (entries) {
431 if (!ext4_valid_extent_idx(inode, ext_idx))
432 return 0;
433 ext_idx++;
434 entries--;
435 }
436 }
437 return 1;
438}
439
440static int __ext4_ext_check(const char *function, unsigned int line,
441 struct inode *inode, struct ext4_extent_header *eh,
442 int depth, ext4_fsblk_t pblk)
443{
444 const char *error_msg;
445 int max = 0, err = -EFSCORRUPTED;
446
447 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
448 error_msg = "invalid magic";
449 goto corrupted;
450 }
451 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
452 error_msg = "unexpected eh_depth";
453 goto corrupted;
454 }
455 if (unlikely(eh->eh_max == 0)) {
456 error_msg = "invalid eh_max";
457 goto corrupted;
458 }
459 max = ext4_ext_max_entries(inode, depth);
460 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
461 error_msg = "too large eh_max";
462 goto corrupted;
463 }
464 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
465 error_msg = "invalid eh_entries";
466 goto corrupted;
467 }
468 if (!ext4_valid_extent_entries(inode, eh, depth)) {
469 error_msg = "invalid extent entries";
470 goto corrupted;
471 }
472 /* Verify checksum on non-root extent tree nodes */
473 if (ext_depth(inode) != depth &&
474 !ext4_extent_block_csum_verify(inode, eh)) {
475 error_msg = "extent tree corrupted";
476 err = -EFSBADCRC;
477 goto corrupted;
478 }
479 return 0;
480
481corrupted:
482 ext4_error_inode(inode, function, line, 0,
483 "pblk %llu bad header/extent: %s - magic %x, "
484 "entries %u, max %u(%u), depth %u(%u)",
485 (unsigned long long) pblk, error_msg,
486 le16_to_cpu(eh->eh_magic),
487 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
488 max, le16_to_cpu(eh->eh_depth), depth);
489 return err;
490}
491
492#define ext4_ext_check(inode, eh, depth, pblk) \
493 __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk))
494
495int ext4_ext_check_inode(struct inode *inode)
496{
497 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
498}
499
500static struct buffer_head *
501__read_extent_tree_block(const char *function, unsigned int line,
502 struct inode *inode, ext4_fsblk_t pblk, int depth,
503 int flags)
504{
505 struct buffer_head *bh;
506 int err;
507
508 bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
509 if (unlikely(!bh))
510 return ERR_PTR(-ENOMEM);
511
512 if (!bh_uptodate_or_lock(bh)) {
513 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
514 err = bh_submit_read(bh);
515 if (err < 0)
516 goto errout;
517 }
518 if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
519 return bh;
520 err = __ext4_ext_check(function, line, inode,
521 ext_block_hdr(bh), depth, pblk);
522 if (err)
523 goto errout;
524 set_buffer_verified(bh);
525 /*
526 * If this is a leaf block, cache all of its entries
527 */
528 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
529 struct ext4_extent_header *eh = ext_block_hdr(bh);
530 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
531 ext4_lblk_t prev = 0;
532 int i;
533
534 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
535 unsigned int status = EXTENT_STATUS_WRITTEN;
536 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
537 int len = ext4_ext_get_actual_len(ex);
538
539 if (prev && (prev != lblk))
540 ext4_es_cache_extent(inode, prev,
541 lblk - prev, ~0,
542 EXTENT_STATUS_HOLE);
543
544 if (ext4_ext_is_unwritten(ex))
545 status = EXTENT_STATUS_UNWRITTEN;
546 ext4_es_cache_extent(inode, lblk, len,
547 ext4_ext_pblock(ex), status);
548 prev = lblk + len;
549 }
550 }
551 return bh;
552errout:
553 put_bh(bh);
554 return ERR_PTR(err);
555
556}
557
558#define read_extent_tree_block(inode, pblk, depth, flags) \
559 __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \
560 (depth), (flags))
561
562/*
563 * This function is called to cache a file's extent information in the
564 * extent status tree
565 */
566int ext4_ext_precache(struct inode *inode)
567{
568 struct ext4_inode_info *ei = EXT4_I(inode);
569 struct ext4_ext_path *path = NULL;
570 struct buffer_head *bh;
571 int i = 0, depth, ret = 0;
572
573 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
574 return 0; /* not an extent-mapped inode */
575
576 down_read(&ei->i_data_sem);
577 depth = ext_depth(inode);
578
579 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
580 GFP_NOFS);
581 if (path == NULL) {
582 up_read(&ei->i_data_sem);
583 return -ENOMEM;
584 }
585
586 /* Don't cache anything if there are no external extent blocks */
587 if (depth == 0)
588 goto out;
589 path[0].p_hdr = ext_inode_hdr(inode);
590 ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
591 if (ret)
592 goto out;
593 path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
594 while (i >= 0) {
595 /*
596 * If this is a leaf block or we've reached the end of
597 * the index block, go up
598 */
599 if ((i == depth) ||
600 path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
601 brelse(path[i].p_bh);
602 path[i].p_bh = NULL;
603 i--;
604 continue;
605 }
606 bh = read_extent_tree_block(inode,
607 ext4_idx_pblock(path[i].p_idx++),
608 depth - i - 1,
609 EXT4_EX_FORCE_CACHE);
610 if (IS_ERR(bh)) {
611 ret = PTR_ERR(bh);
612 break;
613 }
614 i++;
615 path[i].p_bh = bh;
616 path[i].p_hdr = ext_block_hdr(bh);
617 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
618 }
619 ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
620out:
621 up_read(&ei->i_data_sem);
622 ext4_ext_drop_refs(path);
623 kfree(path);
624 return ret;
625}
626
627#ifdef EXT_DEBUG
628static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
629{
630 int k, l = path->p_depth;
631
632 ext_debug("path:");
633 for (k = 0; k <= l; k++, path++) {
634 if (path->p_idx) {
635 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
636 ext4_idx_pblock(path->p_idx));
637 } else if (path->p_ext) {
638 ext_debug(" %d:[%d]%d:%llu ",
639 le32_to_cpu(path->p_ext->ee_block),
640 ext4_ext_is_unwritten(path->p_ext),
641 ext4_ext_get_actual_len(path->p_ext),
642 ext4_ext_pblock(path->p_ext));
643 } else
644 ext_debug(" []");
645 }
646 ext_debug("\n");
647}
648
649static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
650{
651 int depth = ext_depth(inode);
652 struct ext4_extent_header *eh;
653 struct ext4_extent *ex;
654 int i;
655
656 if (!path)
657 return;
658
659 eh = path[depth].p_hdr;
660 ex = EXT_FIRST_EXTENT(eh);
661
662 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
663
664 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
665 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
666 ext4_ext_is_unwritten(ex),
667 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
668 }
669 ext_debug("\n");
670}
671
672static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
673 ext4_fsblk_t newblock, int level)
674{
675 int depth = ext_depth(inode);
676 struct ext4_extent *ex;
677
678 if (depth != level) {
679 struct ext4_extent_idx *idx;
680 idx = path[level].p_idx;
681 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
682 ext_debug("%d: move %d:%llu in new index %llu\n", level,
683 le32_to_cpu(idx->ei_block),
684 ext4_idx_pblock(idx),
685 newblock);
686 idx++;
687 }
688
689 return;
690 }
691
692 ex = path[depth].p_ext;
693 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
694 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
695 le32_to_cpu(ex->ee_block),
696 ext4_ext_pblock(ex),
697 ext4_ext_is_unwritten(ex),
698 ext4_ext_get_actual_len(ex),
699 newblock);
700 ex++;
701 }
702}
703
704#else
705#define ext4_ext_show_path(inode, path)
706#define ext4_ext_show_leaf(inode, path)
707#define ext4_ext_show_move(inode, path, newblock, level)
708#endif
709
710void ext4_ext_drop_refs(struct ext4_ext_path *path)
711{
712 int depth, i;
713
714 if (!path)
715 return;
716 depth = path->p_depth;
717 for (i = 0; i <= depth; i++, path++)
718 if (path->p_bh) {
719 brelse(path->p_bh);
720 path->p_bh = NULL;
721 }
722}
723
724/*
725 * ext4_ext_binsearch_idx:
726 * binary search for the closest index of the given block
727 * the header must be checked before calling this
728 */
729static void
730ext4_ext_binsearch_idx(struct inode *inode,
731 struct ext4_ext_path *path, ext4_lblk_t block)
732{
733 struct ext4_extent_header *eh = path->p_hdr;
734 struct ext4_extent_idx *r, *l, *m;
735
736
737 ext_debug("binsearch for %u(idx): ", block);
738
739 l = EXT_FIRST_INDEX(eh) + 1;
740 r = EXT_LAST_INDEX(eh);
741 while (l <= r) {
742 m = l + (r - l) / 2;
743 if (block < le32_to_cpu(m->ei_block))
744 r = m - 1;
745 else
746 l = m + 1;
747 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
748 m, le32_to_cpu(m->ei_block),
749 r, le32_to_cpu(r->ei_block));
750 }
751
752 path->p_idx = l - 1;
753 ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
754 ext4_idx_pblock(path->p_idx));
755
756#ifdef CHECK_BINSEARCH
757 {
758 struct ext4_extent_idx *chix, *ix;
759 int k;
760
761 chix = ix = EXT_FIRST_INDEX(eh);
762 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
763 if (k != 0 &&
764 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
765 printk(KERN_DEBUG "k=%d, ix=0x%p, "
766 "first=0x%p\n", k,
767 ix, EXT_FIRST_INDEX(eh));
768 printk(KERN_DEBUG "%u <= %u\n",
769 le32_to_cpu(ix->ei_block),
770 le32_to_cpu(ix[-1].ei_block));
771 }
772 BUG_ON(k && le32_to_cpu(ix->ei_block)
773 <= le32_to_cpu(ix[-1].ei_block));
774 if (block < le32_to_cpu(ix->ei_block))
775 break;
776 chix = ix;
777 }
778 BUG_ON(chix != path->p_idx);
779 }
780#endif
781
782}
783
784/*
785 * ext4_ext_binsearch:
786 * binary search for closest extent of the given block
787 * the header must be checked before calling this
788 */
789static void
790ext4_ext_binsearch(struct inode *inode,
791 struct ext4_ext_path *path, ext4_lblk_t block)
792{
793 struct ext4_extent_header *eh = path->p_hdr;
794 struct ext4_extent *r, *l, *m;
795
796 if (eh->eh_entries == 0) {
797 /*
798 * this leaf is empty:
799 * we get such a leaf in split/add case
800 */
801 return;
802 }
803
804 ext_debug("binsearch for %u: ", block);
805
806 l = EXT_FIRST_EXTENT(eh) + 1;
807 r = EXT_LAST_EXTENT(eh);
808
809 while (l <= r) {
810 m = l + (r - l) / 2;
811 if (block < le32_to_cpu(m->ee_block))
812 r = m - 1;
813 else
814 l = m + 1;
815 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
816 m, le32_to_cpu(m->ee_block),
817 r, le32_to_cpu(r->ee_block));
818 }
819
820 path->p_ext = l - 1;
821 ext_debug(" -> %d:%llu:[%d]%d ",
822 le32_to_cpu(path->p_ext->ee_block),
823 ext4_ext_pblock(path->p_ext),
824 ext4_ext_is_unwritten(path->p_ext),
825 ext4_ext_get_actual_len(path->p_ext));
826
827#ifdef CHECK_BINSEARCH
828 {
829 struct ext4_extent *chex, *ex;
830 int k;
831
832 chex = ex = EXT_FIRST_EXTENT(eh);
833 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
834 BUG_ON(k && le32_to_cpu(ex->ee_block)
835 <= le32_to_cpu(ex[-1].ee_block));
836 if (block < le32_to_cpu(ex->ee_block))
837 break;
838 chex = ex;
839 }
840 BUG_ON(chex != path->p_ext);
841 }
842#endif
843
844}
845
846int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
847{
848 struct ext4_extent_header *eh;
849
850 eh = ext_inode_hdr(inode);
851 eh->eh_depth = 0;
852 eh->eh_entries = 0;
853 eh->eh_magic = EXT4_EXT_MAGIC;
854 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
855 ext4_mark_inode_dirty(handle, inode);
856 return 0;
857}
858
859struct ext4_ext_path *
860ext4_find_extent(struct inode *inode, ext4_lblk_t block,
861 struct ext4_ext_path **orig_path, int flags)
862{
863 struct ext4_extent_header *eh;
864 struct buffer_head *bh;
865 struct ext4_ext_path *path = orig_path ? *orig_path : NULL;
866 short int depth, i, ppos = 0;
867 int ret;
868
869 eh = ext_inode_hdr(inode);
870 depth = ext_depth(inode);
871
872 if (path) {
873 ext4_ext_drop_refs(path);
874 if (depth > path[0].p_maxdepth) {
875 kfree(path);
876 *orig_path = path = NULL;
877 }
878 }
879 if (!path) {
880 /* account possible depth increase */
881 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
882 GFP_NOFS);
883 if (unlikely(!path))
884 return ERR_PTR(-ENOMEM);
885 path[0].p_maxdepth = depth + 1;
886 }
887 path[0].p_hdr = eh;
888 path[0].p_bh = NULL;
889
890 i = depth;
891 /* walk through the tree */
892 while (i) {
893 ext_debug("depth %d: num %d, max %d\n",
894 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
895
896 ext4_ext_binsearch_idx(inode, path + ppos, block);
897 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
898 path[ppos].p_depth = i;
899 path[ppos].p_ext = NULL;
900
901 bh = read_extent_tree_block(inode, path[ppos].p_block, --i,
902 flags);
903 if (IS_ERR(bh)) {
904 ret = PTR_ERR(bh);
905 goto err;
906 }
907
908 eh = ext_block_hdr(bh);
909 ppos++;
910 if (unlikely(ppos > depth)) {
911 put_bh(bh);
912 EXT4_ERROR_INODE(inode,
913 "ppos %d > depth %d", ppos, depth);
914 ret = -EFSCORRUPTED;
915 goto err;
916 }
917 path[ppos].p_bh = bh;
918 path[ppos].p_hdr = eh;
919 }
920
921 path[ppos].p_depth = i;
922 path[ppos].p_ext = NULL;
923 path[ppos].p_idx = NULL;
924
925 /* find extent */
926 ext4_ext_binsearch(inode, path + ppos, block);
927 /* if not an empty leaf */
928 if (path[ppos].p_ext)
929 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
930
931 ext4_ext_show_path(inode, path);
932
933 return path;
934
935err:
936 ext4_ext_drop_refs(path);
937 kfree(path);
938 if (orig_path)
939 *orig_path = NULL;
940 return ERR_PTR(ret);
941}
942
943/*
944 * ext4_ext_insert_index:
945 * insert new index [@logical;@ptr] into the block at @curp;
946 * check where to insert: before @curp or after @curp
947 */
948static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
949 struct ext4_ext_path *curp,
950 int logical, ext4_fsblk_t ptr)
951{
952 struct ext4_extent_idx *ix;
953 int len, err;
954
955 err = ext4_ext_get_access(handle, inode, curp);
956 if (err)
957 return err;
958
959 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
960 EXT4_ERROR_INODE(inode,
961 "logical %d == ei_block %d!",
962 logical, le32_to_cpu(curp->p_idx->ei_block));
963 return -EFSCORRUPTED;
964 }
965
966 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
967 >= le16_to_cpu(curp->p_hdr->eh_max))) {
968 EXT4_ERROR_INODE(inode,
969 "eh_entries %d >= eh_max %d!",
970 le16_to_cpu(curp->p_hdr->eh_entries),
971 le16_to_cpu(curp->p_hdr->eh_max));
972 return -EFSCORRUPTED;
973 }
974
975 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
976 /* insert after */
977 ext_debug("insert new index %d after: %llu\n", logical, ptr);
978 ix = curp->p_idx + 1;
979 } else {
980 /* insert before */
981 ext_debug("insert new index %d before: %llu\n", logical, ptr);
982 ix = curp->p_idx;
983 }
984
985 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
986 BUG_ON(len < 0);
987 if (len > 0) {
988 ext_debug("insert new index %d: "
989 "move %d indices from 0x%p to 0x%p\n",
990 logical, len, ix, ix + 1);
991 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
992 }
993
994 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
995 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
996 return -EFSCORRUPTED;
997 }
998
999 ix->ei_block = cpu_to_le32(logical);
1000 ext4_idx_store_pblock(ix, ptr);
1001 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
1002
1003 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
1004 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
1005 return -EFSCORRUPTED;
1006 }
1007
1008 err = ext4_ext_dirty(handle, inode, curp);
1009 ext4_std_error(inode->i_sb, err);
1010
1011 return err;
1012}
1013
1014/*
1015 * ext4_ext_split:
1016 * inserts new subtree into the path, using free index entry
1017 * at depth @at:
1018 * - allocates all needed blocks (new leaf and all intermediate index blocks)
1019 * - makes decision where to split
1020 * - moves remaining extents and index entries (right to the split point)
1021 * into the newly allocated blocks
1022 * - initializes subtree
1023 */
1024static int ext4_ext_split(handle_t *handle, struct inode *inode,
1025 unsigned int flags,
1026 struct ext4_ext_path *path,
1027 struct ext4_extent *newext, int at)
1028{
1029 struct buffer_head *bh = NULL;
1030 int depth = ext_depth(inode);
1031 struct ext4_extent_header *neh;
1032 struct ext4_extent_idx *fidx;
1033 int i = at, k, m, a;
1034 ext4_fsblk_t newblock, oldblock;
1035 __le32 border;
1036 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1037 int err = 0;
1038
1039 /* make decision: where to split? */
1040 /* FIXME: now decision is simplest: at current extent */
1041
1042 /* if current leaf will be split, then we should use
1043 * border from split point */
1044 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1045 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1046 return -EFSCORRUPTED;
1047 }
1048 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1049 border = path[depth].p_ext[1].ee_block;
1050 ext_debug("leaf will be split."
1051 " next leaf starts at %d\n",
1052 le32_to_cpu(border));
1053 } else {
1054 border = newext->ee_block;
1055 ext_debug("leaf will be added."
1056 " next leaf starts at %d\n",
1057 le32_to_cpu(border));
1058 }
1059
1060 /*
1061 * If error occurs, then we break processing
1062 * and mark filesystem read-only. index won't
1063 * be inserted and tree will be in consistent
1064 * state. Next mount will repair buffers too.
1065 */
1066
1067 /*
1068 * Get array to track all allocated blocks.
1069 * We need this to handle errors and free blocks
1070 * upon them.
1071 */
1072 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
1073 if (!ablocks)
1074 return -ENOMEM;
1075
1076 /* allocate all needed blocks */
1077 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
1078 for (a = 0; a < depth - at; a++) {
1079 newblock = ext4_ext_new_meta_block(handle, inode, path,
1080 newext, &err, flags);
1081 if (newblock == 0)
1082 goto cleanup;
1083 ablocks[a] = newblock;
1084 }
1085
1086 /* initialize new leaf */
1087 newblock = ablocks[--a];
1088 if (unlikely(newblock == 0)) {
1089 EXT4_ERROR_INODE(inode, "newblock == 0!");
1090 err = -EFSCORRUPTED;
1091 goto cleanup;
1092 }
1093 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1094 if (unlikely(!bh)) {
1095 err = -ENOMEM;
1096 goto cleanup;
1097 }
1098 lock_buffer(bh);
1099
1100 err = ext4_journal_get_create_access(handle, bh);
1101 if (err)
1102 goto cleanup;
1103
1104 neh = ext_block_hdr(bh);
1105 neh->eh_entries = 0;
1106 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1107 neh->eh_magic = EXT4_EXT_MAGIC;
1108 neh->eh_depth = 0;
1109
1110 /* move remainder of path[depth] to the new leaf */
1111 if (unlikely(path[depth].p_hdr->eh_entries !=
1112 path[depth].p_hdr->eh_max)) {
1113 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1114 path[depth].p_hdr->eh_entries,
1115 path[depth].p_hdr->eh_max);
1116 err = -EFSCORRUPTED;
1117 goto cleanup;
1118 }
1119 /* start copy from next extent */
1120 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1121 ext4_ext_show_move(inode, path, newblock, depth);
1122 if (m) {
1123 struct ext4_extent *ex;
1124 ex = EXT_FIRST_EXTENT(neh);
1125 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1126 le16_add_cpu(&neh->eh_entries, m);
1127 }
1128
1129 ext4_extent_block_csum_set(inode, neh);
1130 set_buffer_uptodate(bh);
1131 unlock_buffer(bh);
1132
1133 err = ext4_handle_dirty_metadata(handle, inode, bh);
1134 if (err)
1135 goto cleanup;
1136 brelse(bh);
1137 bh = NULL;
1138
1139 /* correct old leaf */
1140 if (m) {
1141 err = ext4_ext_get_access(handle, inode, path + depth);
1142 if (err)
1143 goto cleanup;
1144 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1145 err = ext4_ext_dirty(handle, inode, path + depth);
1146 if (err)
1147 goto cleanup;
1148
1149 }
1150
1151 /* create intermediate indexes */
1152 k = depth - at - 1;
1153 if (unlikely(k < 0)) {
1154 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1155 err = -EFSCORRUPTED;
1156 goto cleanup;
1157 }
1158 if (k)
1159 ext_debug("create %d intermediate indices\n", k);
1160 /* insert new index into current index block */
1161 /* current depth stored in i var */
1162 i = depth - 1;
1163 while (k--) {
1164 oldblock = newblock;
1165 newblock = ablocks[--a];
1166 bh = sb_getblk(inode->i_sb, newblock);
1167 if (unlikely(!bh)) {
1168 err = -ENOMEM;
1169 goto cleanup;
1170 }
1171 lock_buffer(bh);
1172
1173 err = ext4_journal_get_create_access(handle, bh);
1174 if (err)
1175 goto cleanup;
1176
1177 neh = ext_block_hdr(bh);
1178 neh->eh_entries = cpu_to_le16(1);
1179 neh->eh_magic = EXT4_EXT_MAGIC;
1180 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1181 neh->eh_depth = cpu_to_le16(depth - i);
1182 fidx = EXT_FIRST_INDEX(neh);
1183 fidx->ei_block = border;
1184 ext4_idx_store_pblock(fidx, oldblock);
1185
1186 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1187 i, newblock, le32_to_cpu(border), oldblock);
1188
1189 /* move remainder of path[i] to the new index block */
1190 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1191 EXT_LAST_INDEX(path[i].p_hdr))) {
1192 EXT4_ERROR_INODE(inode,
1193 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1194 le32_to_cpu(path[i].p_ext->ee_block));
1195 err = -EFSCORRUPTED;
1196 goto cleanup;
1197 }
1198 /* start copy indexes */
1199 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1200 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1201 EXT_MAX_INDEX(path[i].p_hdr));
1202 ext4_ext_show_move(inode, path, newblock, i);
1203 if (m) {
1204 memmove(++fidx, path[i].p_idx,
1205 sizeof(struct ext4_extent_idx) * m);
1206 le16_add_cpu(&neh->eh_entries, m);
1207 }
1208 ext4_extent_block_csum_set(inode, neh);
1209 set_buffer_uptodate(bh);
1210 unlock_buffer(bh);
1211
1212 err = ext4_handle_dirty_metadata(handle, inode, bh);
1213 if (err)
1214 goto cleanup;
1215 brelse(bh);
1216 bh = NULL;
1217
1218 /* correct old index */
1219 if (m) {
1220 err = ext4_ext_get_access(handle, inode, path + i);
1221 if (err)
1222 goto cleanup;
1223 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1224 err = ext4_ext_dirty(handle, inode, path + i);
1225 if (err)
1226 goto cleanup;
1227 }
1228
1229 i--;
1230 }
1231
1232 /* insert new index */
1233 err = ext4_ext_insert_index(handle, inode, path + at,
1234 le32_to_cpu(border), newblock);
1235
1236cleanup:
1237 if (bh) {
1238 if (buffer_locked(bh))
1239 unlock_buffer(bh);
1240 brelse(bh);
1241 }
1242
1243 if (err) {
1244 /* free all allocated blocks in error case */
1245 for (i = 0; i < depth; i++) {
1246 if (!ablocks[i])
1247 continue;
1248 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1249 EXT4_FREE_BLOCKS_METADATA);
1250 }
1251 }
1252 kfree(ablocks);
1253
1254 return err;
1255}
1256
1257/*
1258 * ext4_ext_grow_indepth:
1259 * implements tree growing procedure:
1260 * - allocates new block
1261 * - moves top-level data (index block or leaf) into the new block
1262 * - initializes new top-level, creating index that points to the
1263 * just created block
1264 */
1265static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1266 unsigned int flags)
1267{
1268 struct ext4_extent_header *neh;
1269 struct buffer_head *bh;
1270 ext4_fsblk_t newblock, goal = 0;
1271 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
1272 int err = 0;
1273
1274 /* Try to prepend new index to old one */
1275 if (ext_depth(inode))
1276 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
1277 if (goal > le32_to_cpu(es->s_first_data_block)) {
1278 flags |= EXT4_MB_HINT_TRY_GOAL;
1279 goal--;
1280 } else
1281 goal = ext4_inode_to_goal_block(inode);
1282 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
1283 NULL, &err);
1284 if (newblock == 0)
1285 return err;
1286
1287 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1288 if (unlikely(!bh))
1289 return -ENOMEM;
1290 lock_buffer(bh);
1291
1292 err = ext4_journal_get_create_access(handle, bh);
1293 if (err) {
1294 unlock_buffer(bh);
1295 goto out;
1296 }
1297
1298 /* move top-level index/leaf into new block */
1299 memmove(bh->b_data, EXT4_I(inode)->i_data,
1300 sizeof(EXT4_I(inode)->i_data));
1301
1302 /* set size of new block */
1303 neh = ext_block_hdr(bh);
1304 /* old root could have indexes or leaves
1305 * so calculate e_max right way */
1306 if (ext_depth(inode))
1307 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1308 else
1309 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1310 neh->eh_magic = EXT4_EXT_MAGIC;
1311 ext4_extent_block_csum_set(inode, neh);
1312 set_buffer_uptodate(bh);
1313 unlock_buffer(bh);
1314
1315 err = ext4_handle_dirty_metadata(handle, inode, bh);
1316 if (err)
1317 goto out;
1318
1319 /* Update top-level index: num,max,pointer */
1320 neh = ext_inode_hdr(inode);
1321 neh->eh_entries = cpu_to_le16(1);
1322 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1323 if (neh->eh_depth == 0) {
1324 /* Root extent block becomes index block */
1325 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1326 EXT_FIRST_INDEX(neh)->ei_block =
1327 EXT_FIRST_EXTENT(neh)->ee_block;
1328 }
1329 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1330 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1331 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1332 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1333
1334 le16_add_cpu(&neh->eh_depth, 1);
1335 ext4_mark_inode_dirty(handle, inode);
1336out:
1337 brelse(bh);
1338
1339 return err;
1340}
1341
1342/*
1343 * ext4_ext_create_new_leaf:
1344 * finds empty index and adds new leaf.
1345 * if no free index is found, then it requests in-depth growing.
1346 */
1347static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1348 unsigned int mb_flags,
1349 unsigned int gb_flags,
1350 struct ext4_ext_path **ppath,
1351 struct ext4_extent *newext)
1352{
1353 struct ext4_ext_path *path = *ppath;
1354 struct ext4_ext_path *curp;
1355 int depth, i, err = 0;
1356
1357repeat:
1358 i = depth = ext_depth(inode);
1359
1360 /* walk up to the tree and look for free index entry */
1361 curp = path + depth;
1362 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1363 i--;
1364 curp--;
1365 }
1366
1367 /* we use already allocated block for index block,
1368 * so subsequent data blocks should be contiguous */
1369 if (EXT_HAS_FREE_INDEX(curp)) {
1370 /* if we found index with free entry, then use that
1371 * entry: create all needed subtree and add new leaf */
1372 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
1373 if (err)
1374 goto out;
1375
1376 /* refill path */
1377 path = ext4_find_extent(inode,
1378 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1379 ppath, gb_flags);
1380 if (IS_ERR(path))
1381 err = PTR_ERR(path);
1382 } else {
1383 /* tree is full, time to grow in depth */
1384 err = ext4_ext_grow_indepth(handle, inode, mb_flags);
1385 if (err)
1386 goto out;
1387
1388 /* refill path */
1389 path = ext4_find_extent(inode,
1390 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1391 ppath, gb_flags);
1392 if (IS_ERR(path)) {
1393 err = PTR_ERR(path);
1394 goto out;
1395 }
1396
1397 /*
1398 * only first (depth 0 -> 1) produces free space;
1399 * in all other cases we have to split the grown tree
1400 */
1401 depth = ext_depth(inode);
1402 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1403 /* now we need to split */
1404 goto repeat;
1405 }
1406 }
1407
1408out:
1409 return err;
1410}
1411
1412/*
1413 * search the closest allocated block to the left for *logical
1414 * and returns it at @logical + it's physical address at @phys
1415 * if *logical is the smallest allocated block, the function
1416 * returns 0 at @phys
1417 * return value contains 0 (success) or error code
1418 */
1419static int ext4_ext_search_left(struct inode *inode,
1420 struct ext4_ext_path *path,
1421 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1422{
1423 struct ext4_extent_idx *ix;
1424 struct ext4_extent *ex;
1425 int depth, ee_len;
1426
1427 if (unlikely(path == NULL)) {
1428 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1429 return -EFSCORRUPTED;
1430 }
1431 depth = path->p_depth;
1432 *phys = 0;
1433
1434 if (depth == 0 && path->p_ext == NULL)
1435 return 0;
1436
1437 /* usually extent in the path covers blocks smaller
1438 * then *logical, but it can be that extent is the
1439 * first one in the file */
1440
1441 ex = path[depth].p_ext;
1442 ee_len = ext4_ext_get_actual_len(ex);
1443 if (*logical < le32_to_cpu(ex->ee_block)) {
1444 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1445 EXT4_ERROR_INODE(inode,
1446 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1447 *logical, le32_to_cpu(ex->ee_block));
1448 return -EFSCORRUPTED;
1449 }
1450 while (--depth >= 0) {
1451 ix = path[depth].p_idx;
1452 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1453 EXT4_ERROR_INODE(inode,
1454 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1455 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1456 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1457 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1458 depth);
1459 return -EFSCORRUPTED;
1460 }
1461 }
1462 return 0;
1463 }
1464
1465 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1466 EXT4_ERROR_INODE(inode,
1467 "logical %d < ee_block %d + ee_len %d!",
1468 *logical, le32_to_cpu(ex->ee_block), ee_len);
1469 return -EFSCORRUPTED;
1470 }
1471
1472 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1473 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1474 return 0;
1475}
1476
1477/*
1478 * search the closest allocated block to the right for *logical
1479 * and returns it at @logical + it's physical address at @phys
1480 * if *logical is the largest allocated block, the function
1481 * returns 0 at @phys
1482 * return value contains 0 (success) or error code
1483 */
1484static int ext4_ext_search_right(struct inode *inode,
1485 struct ext4_ext_path *path,
1486 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1487 struct ext4_extent **ret_ex)
1488{
1489 struct buffer_head *bh = NULL;
1490 struct ext4_extent_header *eh;
1491 struct ext4_extent_idx *ix;
1492 struct ext4_extent *ex;
1493 ext4_fsblk_t block;
1494 int depth; /* Note, NOT eh_depth; depth from top of tree */
1495 int ee_len;
1496
1497 if (unlikely(path == NULL)) {
1498 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1499 return -EFSCORRUPTED;
1500 }
1501 depth = path->p_depth;
1502 *phys = 0;
1503
1504 if (depth == 0 && path->p_ext == NULL)
1505 return 0;
1506
1507 /* usually extent in the path covers blocks smaller
1508 * then *logical, but it can be that extent is the
1509 * first one in the file */
1510
1511 ex = path[depth].p_ext;
1512 ee_len = ext4_ext_get_actual_len(ex);
1513 if (*logical < le32_to_cpu(ex->ee_block)) {
1514 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1515 EXT4_ERROR_INODE(inode,
1516 "first_extent(path[%d].p_hdr) != ex",
1517 depth);
1518 return -EFSCORRUPTED;
1519 }
1520 while (--depth >= 0) {
1521 ix = path[depth].p_idx;
1522 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1523 EXT4_ERROR_INODE(inode,
1524 "ix != EXT_FIRST_INDEX *logical %d!",
1525 *logical);
1526 return -EFSCORRUPTED;
1527 }
1528 }
1529 goto found_extent;
1530 }
1531
1532 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1533 EXT4_ERROR_INODE(inode,
1534 "logical %d < ee_block %d + ee_len %d!",
1535 *logical, le32_to_cpu(ex->ee_block), ee_len);
1536 return -EFSCORRUPTED;
1537 }
1538
1539 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1540 /* next allocated block in this leaf */
1541 ex++;
1542 goto found_extent;
1543 }
1544
1545 /* go up and search for index to the right */
1546 while (--depth >= 0) {
1547 ix = path[depth].p_idx;
1548 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1549 goto got_index;
1550 }
1551
1552 /* we've gone up to the root and found no index to the right */
1553 return 0;
1554
1555got_index:
1556 /* we've found index to the right, let's
1557 * follow it and find the closest allocated
1558 * block to the right */
1559 ix++;
1560 block = ext4_idx_pblock(ix);
1561 while (++depth < path->p_depth) {
1562 /* subtract from p_depth to get proper eh_depth */
1563 bh = read_extent_tree_block(inode, block,
1564 path->p_depth - depth, 0);
1565 if (IS_ERR(bh))
1566 return PTR_ERR(bh);
1567 eh = ext_block_hdr(bh);
1568 ix = EXT_FIRST_INDEX(eh);
1569 block = ext4_idx_pblock(ix);
1570 put_bh(bh);
1571 }
1572
1573 bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0);
1574 if (IS_ERR(bh))
1575 return PTR_ERR(bh);
1576 eh = ext_block_hdr(bh);
1577 ex = EXT_FIRST_EXTENT(eh);
1578found_extent:
1579 *logical = le32_to_cpu(ex->ee_block);
1580 *phys = ext4_ext_pblock(ex);
1581 *ret_ex = ex;
1582 if (bh)
1583 put_bh(bh);
1584 return 0;
1585}
1586
1587/*
1588 * ext4_ext_next_allocated_block:
1589 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1590 * NOTE: it considers block number from index entry as
1591 * allocated block. Thus, index entries have to be consistent
1592 * with leaves.
1593 */
1594ext4_lblk_t
1595ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1596{
1597 int depth;
1598
1599 BUG_ON(path == NULL);
1600 depth = path->p_depth;
1601
1602 if (depth == 0 && path->p_ext == NULL)
1603 return EXT_MAX_BLOCKS;
1604
1605 while (depth >= 0) {
1606 if (depth == path->p_depth) {
1607 /* leaf */
1608 if (path[depth].p_ext &&
1609 path[depth].p_ext !=
1610 EXT_LAST_EXTENT(path[depth].p_hdr))
1611 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1612 } else {
1613 /* index */
1614 if (path[depth].p_idx !=
1615 EXT_LAST_INDEX(path[depth].p_hdr))
1616 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1617 }
1618 depth--;
1619 }
1620
1621 return EXT_MAX_BLOCKS;
1622}
1623
1624/*
1625 * ext4_ext_next_leaf_block:
1626 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1627 */
1628static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1629{
1630 int depth;
1631
1632 BUG_ON(path == NULL);
1633 depth = path->p_depth;
1634
1635 /* zero-tree has no leaf blocks at all */
1636 if (depth == 0)
1637 return EXT_MAX_BLOCKS;
1638
1639 /* go to index block */
1640 depth--;
1641
1642 while (depth >= 0) {
1643 if (path[depth].p_idx !=
1644 EXT_LAST_INDEX(path[depth].p_hdr))
1645 return (ext4_lblk_t)
1646 le32_to_cpu(path[depth].p_idx[1].ei_block);
1647 depth--;
1648 }
1649
1650 return EXT_MAX_BLOCKS;
1651}
1652
1653/*
1654 * ext4_ext_correct_indexes:
1655 * if leaf gets modified and modified extent is first in the leaf,
1656 * then we have to correct all indexes above.
1657 * TODO: do we need to correct tree in all cases?
1658 */
1659static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1660 struct ext4_ext_path *path)
1661{
1662 struct ext4_extent_header *eh;
1663 int depth = ext_depth(inode);
1664 struct ext4_extent *ex;
1665 __le32 border;
1666 int k, err = 0;
1667
1668 eh = path[depth].p_hdr;
1669 ex = path[depth].p_ext;
1670
1671 if (unlikely(ex == NULL || eh == NULL)) {
1672 EXT4_ERROR_INODE(inode,
1673 "ex %p == NULL or eh %p == NULL", ex, eh);
1674 return -EFSCORRUPTED;
1675 }
1676
1677 if (depth == 0) {
1678 /* there is no tree at all */
1679 return 0;
1680 }
1681
1682 if (ex != EXT_FIRST_EXTENT(eh)) {
1683 /* we correct tree if first leaf got modified only */
1684 return 0;
1685 }
1686
1687 /*
1688 * TODO: we need correction if border is smaller than current one
1689 */
1690 k = depth - 1;
1691 border = path[depth].p_ext->ee_block;
1692 err = ext4_ext_get_access(handle, inode, path + k);
1693 if (err)
1694 return err;
1695 path[k].p_idx->ei_block = border;
1696 err = ext4_ext_dirty(handle, inode, path + k);
1697 if (err)
1698 return err;
1699
1700 while (k--) {
1701 /* change all left-side indexes */
1702 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1703 break;
1704 err = ext4_ext_get_access(handle, inode, path + k);
1705 if (err)
1706 break;
1707 path[k].p_idx->ei_block = border;
1708 err = ext4_ext_dirty(handle, inode, path + k);
1709 if (err)
1710 break;
1711 }
1712
1713 return err;
1714}
1715
1716int
1717ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1718 struct ext4_extent *ex2)
1719{
1720 unsigned short ext1_ee_len, ext2_ee_len;
1721
1722 if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
1723 return 0;
1724
1725 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1726 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1727
1728 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1729 le32_to_cpu(ex2->ee_block))
1730 return 0;
1731
1732 /*
1733 * To allow future support for preallocated extents to be added
1734 * as an RO_COMPAT feature, refuse to merge to extents if
1735 * this can result in the top bit of ee_len being set.
1736 */
1737 if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1738 return 0;
1739 /*
1740 * The check for IO to unwritten extent is somewhat racy as we
1741 * increment i_unwritten / set EXT4_STATE_DIO_UNWRITTEN only after
1742 * dropping i_data_sem. But reserved blocks should save us in that
1743 * case.
1744 */
1745 if (ext4_ext_is_unwritten(ex1) &&
1746 (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) ||
1747 atomic_read(&EXT4_I(inode)->i_unwritten) ||
1748 (ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)))
1749 return 0;
1750#ifdef AGGRESSIVE_TEST
1751 if (ext1_ee_len >= 4)
1752 return 0;
1753#endif
1754
1755 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1756 return 1;
1757 return 0;
1758}
1759
1760/*
1761 * This function tries to merge the "ex" extent to the next extent in the tree.
1762 * It always tries to merge towards right. If you want to merge towards
1763 * left, pass "ex - 1" as argument instead of "ex".
1764 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1765 * 1 if they got merged.
1766 */
1767static int ext4_ext_try_to_merge_right(struct inode *inode,
1768 struct ext4_ext_path *path,
1769 struct ext4_extent *ex)
1770{
1771 struct ext4_extent_header *eh;
1772 unsigned int depth, len;
1773 int merge_done = 0, unwritten;
1774
1775 depth = ext_depth(inode);
1776 BUG_ON(path[depth].p_hdr == NULL);
1777 eh = path[depth].p_hdr;
1778
1779 while (ex < EXT_LAST_EXTENT(eh)) {
1780 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1781 break;
1782 /* merge with next extent! */
1783 unwritten = ext4_ext_is_unwritten(ex);
1784 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1785 + ext4_ext_get_actual_len(ex + 1));
1786 if (unwritten)
1787 ext4_ext_mark_unwritten(ex);
1788
1789 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1790 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1791 * sizeof(struct ext4_extent);
1792 memmove(ex + 1, ex + 2, len);
1793 }
1794 le16_add_cpu(&eh->eh_entries, -1);
1795 merge_done = 1;
1796 WARN_ON(eh->eh_entries == 0);
1797 if (!eh->eh_entries)
1798 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1799 }
1800
1801 return merge_done;
1802}
1803
1804/*
1805 * This function does a very simple check to see if we can collapse
1806 * an extent tree with a single extent tree leaf block into the inode.
1807 */
1808static void ext4_ext_try_to_merge_up(handle_t *handle,
1809 struct inode *inode,
1810 struct ext4_ext_path *path)
1811{
1812 size_t s;
1813 unsigned max_root = ext4_ext_space_root(inode, 0);
1814 ext4_fsblk_t blk;
1815
1816 if ((path[0].p_depth != 1) ||
1817 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1818 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1819 return;
1820
1821 /*
1822 * We need to modify the block allocation bitmap and the block
1823 * group descriptor to release the extent tree block. If we
1824 * can't get the journal credits, give up.
1825 */
1826 if (ext4_journal_extend(handle, 2))
1827 return;
1828
1829 /*
1830 * Copy the extent data up to the inode
1831 */
1832 blk = ext4_idx_pblock(path[0].p_idx);
1833 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1834 sizeof(struct ext4_extent_idx);
1835 s += sizeof(struct ext4_extent_header);
1836
1837 path[1].p_maxdepth = path[0].p_maxdepth;
1838 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1839 path[0].p_depth = 0;
1840 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1841 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1842 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1843
1844 brelse(path[1].p_bh);
1845 ext4_free_blocks(handle, inode, NULL, blk, 1,
1846 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1847}
1848
1849/*
1850 * This function tries to merge the @ex extent to neighbours in the tree.
1851 * return 1 if merge left else 0.
1852 */
1853static void ext4_ext_try_to_merge(handle_t *handle,
1854 struct inode *inode,
1855 struct ext4_ext_path *path,
1856 struct ext4_extent *ex) {
1857 struct ext4_extent_header *eh;
1858 unsigned int depth;
1859 int merge_done = 0;
1860
1861 depth = ext_depth(inode);
1862 BUG_ON(path[depth].p_hdr == NULL);
1863 eh = path[depth].p_hdr;
1864
1865 if (ex > EXT_FIRST_EXTENT(eh))
1866 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1867
1868 if (!merge_done)
1869 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1870
1871 ext4_ext_try_to_merge_up(handle, inode, path);
1872}
1873
1874/*
1875 * check if a portion of the "newext" extent overlaps with an
1876 * existing extent.
1877 *
1878 * If there is an overlap discovered, it updates the length of the newext
1879 * such that there will be no overlap, and then returns 1.
1880 * If there is no overlap found, it returns 0.
1881 */
1882static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1883 struct inode *inode,
1884 struct ext4_extent *newext,
1885 struct ext4_ext_path *path)
1886{
1887 ext4_lblk_t b1, b2;
1888 unsigned int depth, len1;
1889 unsigned int ret = 0;
1890
1891 b1 = le32_to_cpu(newext->ee_block);
1892 len1 = ext4_ext_get_actual_len(newext);
1893 depth = ext_depth(inode);
1894 if (!path[depth].p_ext)
1895 goto out;
1896 b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
1897
1898 /*
1899 * get the next allocated block if the extent in the path
1900 * is before the requested block(s)
1901 */
1902 if (b2 < b1) {
1903 b2 = ext4_ext_next_allocated_block(path);
1904 if (b2 == EXT_MAX_BLOCKS)
1905 goto out;
1906 b2 = EXT4_LBLK_CMASK(sbi, b2);
1907 }
1908
1909 /* check for wrap through zero on extent logical start block*/
1910 if (b1 + len1 < b1) {
1911 len1 = EXT_MAX_BLOCKS - b1;
1912 newext->ee_len = cpu_to_le16(len1);
1913 ret = 1;
1914 }
1915
1916 /* check for overlap */
1917 if (b1 + len1 > b2) {
1918 newext->ee_len = cpu_to_le16(b2 - b1);
1919 ret = 1;
1920 }
1921out:
1922 return ret;
1923}
1924
1925/*
1926 * ext4_ext_insert_extent:
1927 * tries to merge requsted extent into the existing extent or
1928 * inserts requested extent as new one into the tree,
1929 * creating new leaf in the no-space case.
1930 */
1931int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1932 struct ext4_ext_path **ppath,
1933 struct ext4_extent *newext, int gb_flags)
1934{
1935 struct ext4_ext_path *path = *ppath;
1936 struct ext4_extent_header *eh;
1937 struct ext4_extent *ex, *fex;
1938 struct ext4_extent *nearex; /* nearest extent */
1939 struct ext4_ext_path *npath = NULL;
1940 int depth, len, err;
1941 ext4_lblk_t next;
1942 int mb_flags = 0, unwritten;
1943
1944 if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1945 mb_flags |= EXT4_MB_DELALLOC_RESERVED;
1946 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1947 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1948 return -EFSCORRUPTED;
1949 }
1950 depth = ext_depth(inode);
1951 ex = path[depth].p_ext;
1952 eh = path[depth].p_hdr;
1953 if (unlikely(path[depth].p_hdr == NULL)) {
1954 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1955 return -EFSCORRUPTED;
1956 }
1957
1958 /* try to insert block into found extent and return */
1959 if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
1960
1961 /*
1962 * Try to see whether we should rather test the extent on
1963 * right from ex, or from the left of ex. This is because
1964 * ext4_find_extent() can return either extent on the
1965 * left, or on the right from the searched position. This
1966 * will make merging more effective.
1967 */
1968 if (ex < EXT_LAST_EXTENT(eh) &&
1969 (le32_to_cpu(ex->ee_block) +
1970 ext4_ext_get_actual_len(ex) <
1971 le32_to_cpu(newext->ee_block))) {
1972 ex += 1;
1973 goto prepend;
1974 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
1975 (le32_to_cpu(newext->ee_block) +
1976 ext4_ext_get_actual_len(newext) <
1977 le32_to_cpu(ex->ee_block)))
1978 ex -= 1;
1979
1980 /* Try to append newex to the ex */
1981 if (ext4_can_extents_be_merged(inode, ex, newext)) {
1982 ext_debug("append [%d]%d block to %u:[%d]%d"
1983 "(from %llu)\n",
1984 ext4_ext_is_unwritten(newext),
1985 ext4_ext_get_actual_len(newext),
1986 le32_to_cpu(ex->ee_block),
1987 ext4_ext_is_unwritten(ex),
1988 ext4_ext_get_actual_len(ex),
1989 ext4_ext_pblock(ex));
1990 err = ext4_ext_get_access(handle, inode,
1991 path + depth);
1992 if (err)
1993 return err;
1994 unwritten = ext4_ext_is_unwritten(ex);
1995 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1996 + ext4_ext_get_actual_len(newext));
1997 if (unwritten)
1998 ext4_ext_mark_unwritten(ex);
1999 eh = path[depth].p_hdr;
2000 nearex = ex;
2001 goto merge;
2002 }
2003
2004prepend:
2005 /* Try to prepend newex to the ex */
2006 if (ext4_can_extents_be_merged(inode, newext, ex)) {
2007 ext_debug("prepend %u[%d]%d block to %u:[%d]%d"
2008 "(from %llu)\n",
2009 le32_to_cpu(newext->ee_block),
2010 ext4_ext_is_unwritten(newext),
2011 ext4_ext_get_actual_len(newext),
2012 le32_to_cpu(ex->ee_block),
2013 ext4_ext_is_unwritten(ex),
2014 ext4_ext_get_actual_len(ex),
2015 ext4_ext_pblock(ex));
2016 err = ext4_ext_get_access(handle, inode,
2017 path + depth);
2018 if (err)
2019 return err;
2020
2021 unwritten = ext4_ext_is_unwritten(ex);
2022 ex->ee_block = newext->ee_block;
2023 ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
2024 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2025 + ext4_ext_get_actual_len(newext));
2026 if (unwritten)
2027 ext4_ext_mark_unwritten(ex);
2028 eh = path[depth].p_hdr;
2029 nearex = ex;
2030 goto merge;
2031 }
2032 }
2033
2034 depth = ext_depth(inode);
2035 eh = path[depth].p_hdr;
2036 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
2037 goto has_space;
2038
2039 /* probably next leaf has space for us? */
2040 fex = EXT_LAST_EXTENT(eh);
2041 next = EXT_MAX_BLOCKS;
2042 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
2043 next = ext4_ext_next_leaf_block(path);
2044 if (next != EXT_MAX_BLOCKS) {
2045 ext_debug("next leaf block - %u\n", next);
2046 BUG_ON(npath != NULL);
2047 npath = ext4_find_extent(inode, next, NULL, 0);
2048 if (IS_ERR(npath))
2049 return PTR_ERR(npath);
2050 BUG_ON(npath->p_depth != path->p_depth);
2051 eh = npath[depth].p_hdr;
2052 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2053 ext_debug("next leaf isn't full(%d)\n",
2054 le16_to_cpu(eh->eh_entries));
2055 path = npath;
2056 goto has_space;
2057 }
2058 ext_debug("next leaf has no free space(%d,%d)\n",
2059 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2060 }
2061
2062 /*
2063 * There is no free space in the found leaf.
2064 * We're gonna add a new leaf in the tree.
2065 */
2066 if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2067 mb_flags |= EXT4_MB_USE_RESERVED;
2068 err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2069 ppath, newext);
2070 if (err)
2071 goto cleanup;
2072 depth = ext_depth(inode);
2073 eh = path[depth].p_hdr;
2074
2075has_space:
2076 nearex = path[depth].p_ext;
2077
2078 err = ext4_ext_get_access(handle, inode, path + depth);
2079 if (err)
2080 goto cleanup;
2081
2082 if (!nearex) {
2083 /* there is no extent in this leaf, create first one */
2084 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
2085 le32_to_cpu(newext->ee_block),
2086 ext4_ext_pblock(newext),
2087 ext4_ext_is_unwritten(newext),
2088 ext4_ext_get_actual_len(newext));
2089 nearex = EXT_FIRST_EXTENT(eh);
2090 } else {
2091 if (le32_to_cpu(newext->ee_block)
2092 > le32_to_cpu(nearex->ee_block)) {
2093 /* Insert after */
2094 ext_debug("insert %u:%llu:[%d]%d before: "
2095 "nearest %p\n",
2096 le32_to_cpu(newext->ee_block),
2097 ext4_ext_pblock(newext),
2098 ext4_ext_is_unwritten(newext),
2099 ext4_ext_get_actual_len(newext),
2100 nearex);
2101 nearex++;
2102 } else {
2103 /* Insert before */
2104 BUG_ON(newext->ee_block == nearex->ee_block);
2105 ext_debug("insert %u:%llu:[%d]%d after: "
2106 "nearest %p\n",
2107 le32_to_cpu(newext->ee_block),
2108 ext4_ext_pblock(newext),
2109 ext4_ext_is_unwritten(newext),
2110 ext4_ext_get_actual_len(newext),
2111 nearex);
2112 }
2113 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2114 if (len > 0) {
2115 ext_debug("insert %u:%llu:[%d]%d: "
2116 "move %d extents from 0x%p to 0x%p\n",
2117 le32_to_cpu(newext->ee_block),
2118 ext4_ext_pblock(newext),
2119 ext4_ext_is_unwritten(newext),
2120 ext4_ext_get_actual_len(newext),
2121 len, nearex, nearex + 1);
2122 memmove(nearex + 1, nearex,
2123 len * sizeof(struct ext4_extent));
2124 }
2125 }
2126
2127 le16_add_cpu(&eh->eh_entries, 1);
2128 path[depth].p_ext = nearex;
2129 nearex->ee_block = newext->ee_block;
2130 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2131 nearex->ee_len = newext->ee_len;
2132
2133merge:
2134 /* try to merge extents */
2135 if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2136 ext4_ext_try_to_merge(handle, inode, path, nearex);
2137
2138
2139 /* time to correct all indexes above */
2140 err = ext4_ext_correct_indexes(handle, inode, path);
2141 if (err)
2142 goto cleanup;
2143
2144 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2145
2146cleanup:
2147 ext4_ext_drop_refs(npath);
2148 kfree(npath);
2149 return err;
2150}
2151
2152static int ext4_fill_fiemap_extents(struct inode *inode,
2153 ext4_lblk_t block, ext4_lblk_t num,
2154 struct fiemap_extent_info *fieinfo)
2155{
2156 struct ext4_ext_path *path = NULL;
2157 struct ext4_extent *ex;
2158 struct extent_status es;
2159 ext4_lblk_t next, next_del, start = 0, end = 0;
2160 ext4_lblk_t last = block + num;
2161 int exists, depth = 0, err = 0;
2162 unsigned int flags = 0;
2163 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2164
2165 while (block < last && block != EXT_MAX_BLOCKS) {
2166 num = last - block;
2167 /* find extent for this block */
2168 down_read(&EXT4_I(inode)->i_data_sem);
2169
2170 path = ext4_find_extent(inode, block, &path, 0);
2171 if (IS_ERR(path)) {
2172 up_read(&EXT4_I(inode)->i_data_sem);
2173 err = PTR_ERR(path);
2174 path = NULL;
2175 break;
2176 }
2177
2178 depth = ext_depth(inode);
2179 if (unlikely(path[depth].p_hdr == NULL)) {
2180 up_read(&EXT4_I(inode)->i_data_sem);
2181 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2182 err = -EFSCORRUPTED;
2183 break;
2184 }
2185 ex = path[depth].p_ext;
2186 next = ext4_ext_next_allocated_block(path);
2187
2188 flags = 0;
2189 exists = 0;
2190 if (!ex) {
2191 /* there is no extent yet, so try to allocate
2192 * all requested space */
2193 start = block;
2194 end = block + num;
2195 } else if (le32_to_cpu(ex->ee_block) > block) {
2196 /* need to allocate space before found extent */
2197 start = block;
2198 end = le32_to_cpu(ex->ee_block);
2199 if (block + num < end)
2200 end = block + num;
2201 } else if (block >= le32_to_cpu(ex->ee_block)
2202 + ext4_ext_get_actual_len(ex)) {
2203 /* need to allocate space after found extent */
2204 start = block;
2205 end = block + num;
2206 if (end >= next)
2207 end = next;
2208 } else if (block >= le32_to_cpu(ex->ee_block)) {
2209 /*
2210 * some part of requested space is covered
2211 * by found extent
2212 */
2213 start = block;
2214 end = le32_to_cpu(ex->ee_block)
2215 + ext4_ext_get_actual_len(ex);
2216 if (block + num < end)
2217 end = block + num;
2218 exists = 1;
2219 } else {
2220 BUG();
2221 }
2222 BUG_ON(end <= start);
2223
2224 if (!exists) {
2225 es.es_lblk = start;
2226 es.es_len = end - start;
2227 es.es_pblk = 0;
2228 } else {
2229 es.es_lblk = le32_to_cpu(ex->ee_block);
2230 es.es_len = ext4_ext_get_actual_len(ex);
2231 es.es_pblk = ext4_ext_pblock(ex);
2232 if (ext4_ext_is_unwritten(ex))
2233 flags |= FIEMAP_EXTENT_UNWRITTEN;
2234 }
2235
2236 /*
2237 * Find delayed extent and update es accordingly. We call
2238 * it even in !exists case to find out whether es is the
2239 * last existing extent or not.
2240 */
2241 next_del = ext4_find_delayed_extent(inode, &es);
2242 if (!exists && next_del) {
2243 exists = 1;
2244 flags |= (FIEMAP_EXTENT_DELALLOC |
2245 FIEMAP_EXTENT_UNKNOWN);
2246 }
2247 up_read(&EXT4_I(inode)->i_data_sem);
2248
2249 if (unlikely(es.es_len == 0)) {
2250 EXT4_ERROR_INODE(inode, "es.es_len == 0");
2251 err = -EFSCORRUPTED;
2252 break;
2253 }
2254
2255 /*
2256 * This is possible iff next == next_del == EXT_MAX_BLOCKS.
2257 * we need to check next == EXT_MAX_BLOCKS because it is
2258 * possible that an extent is with unwritten and delayed
2259 * status due to when an extent is delayed allocated and
2260 * is allocated by fallocate status tree will track both of
2261 * them in a extent.
2262 *
2263 * So we could return a unwritten and delayed extent, and
2264 * its block is equal to 'next'.
2265 */
2266 if (next == next_del && next == EXT_MAX_BLOCKS) {
2267 flags |= FIEMAP_EXTENT_LAST;
2268 if (unlikely(next_del != EXT_MAX_BLOCKS ||
2269 next != EXT_MAX_BLOCKS)) {
2270 EXT4_ERROR_INODE(inode,
2271 "next extent == %u, next "
2272 "delalloc extent = %u",
2273 next, next_del);
2274 err = -EFSCORRUPTED;
2275 break;
2276 }
2277 }
2278
2279 if (exists) {
2280 err = fiemap_fill_next_extent(fieinfo,
2281 (__u64)es.es_lblk << blksize_bits,
2282 (__u64)es.es_pblk << blksize_bits,
2283 (__u64)es.es_len << blksize_bits,
2284 flags);
2285 if (err < 0)
2286 break;
2287 if (err == 1) {
2288 err = 0;
2289 break;
2290 }
2291 }
2292
2293 block = es.es_lblk + es.es_len;
2294 }
2295
2296 ext4_ext_drop_refs(path);
2297 kfree(path);
2298 return err;
2299}
2300
2301/*
2302 * ext4_ext_determine_hole - determine hole around given block
2303 * @inode: inode we lookup in
2304 * @path: path in extent tree to @lblk
2305 * @lblk: pointer to logical block around which we want to determine hole
2306 *
2307 * Determine hole length (and start if easily possible) around given logical
2308 * block. We don't try too hard to find the beginning of the hole but @path
2309 * actually points to extent before @lblk, we provide it.
2310 *
2311 * The function returns the length of a hole starting at @lblk. We update @lblk
2312 * to the beginning of the hole if we managed to find it.
2313 */
2314static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode,
2315 struct ext4_ext_path *path,
2316 ext4_lblk_t *lblk)
2317{
2318 int depth = ext_depth(inode);
2319 struct ext4_extent *ex;
2320 ext4_lblk_t len;
2321
2322 ex = path[depth].p_ext;
2323 if (ex == NULL) {
2324 /* there is no extent yet, so gap is [0;-] */
2325 *lblk = 0;
2326 len = EXT_MAX_BLOCKS;
2327 } else if (*lblk < le32_to_cpu(ex->ee_block)) {
2328 len = le32_to_cpu(ex->ee_block) - *lblk;
2329 } else if (*lblk >= le32_to_cpu(ex->ee_block)
2330 + ext4_ext_get_actual_len(ex)) {
2331 ext4_lblk_t next;
2332
2333 *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
2334 next = ext4_ext_next_allocated_block(path);
2335 BUG_ON(next == *lblk);
2336 len = next - *lblk;
2337 } else {
2338 BUG();
2339 }
2340 return len;
2341}
2342
2343/*
2344 * ext4_ext_put_gap_in_cache:
2345 * calculate boundaries of the gap that the requested block fits into
2346 * and cache this gap
2347 */
2348static void
2349ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start,
2350 ext4_lblk_t hole_len)
2351{
2352 struct extent_status es;
2353
2354 ext4_es_find_delayed_extent_range(inode, hole_start,
2355 hole_start + hole_len - 1, &es);
2356 if (es.es_len) {
2357 /* There's delayed extent containing lblock? */
2358 if (es.es_lblk <= hole_start)
2359 return;
2360 hole_len = min(es.es_lblk - hole_start, hole_len);
2361 }
2362 ext_debug(" -> %u:%u\n", hole_start, hole_len);
2363 ext4_es_insert_extent(inode, hole_start, hole_len, ~0,
2364 EXTENT_STATUS_HOLE);
2365}
2366
2367/*
2368 * ext4_ext_rm_idx:
2369 * removes index from the index block.
2370 */
2371static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2372 struct ext4_ext_path *path, int depth)
2373{
2374 int err;
2375 ext4_fsblk_t leaf;
2376
2377 /* free index block */
2378 depth--;
2379 path = path + depth;
2380 leaf = ext4_idx_pblock(path->p_idx);
2381 if (unlikely(path->p_hdr->eh_entries == 0)) {
2382 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2383 return -EFSCORRUPTED;
2384 }
2385 err = ext4_ext_get_access(handle, inode, path);
2386 if (err)
2387 return err;
2388
2389 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2390 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2391 len *= sizeof(struct ext4_extent_idx);
2392 memmove(path->p_idx, path->p_idx + 1, len);
2393 }
2394
2395 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2396 err = ext4_ext_dirty(handle, inode, path);
2397 if (err)
2398 return err;
2399 ext_debug("index is empty, remove it, free block %llu\n", leaf);
2400 trace_ext4_ext_rm_idx(inode, leaf);
2401
2402 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2403 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2404
2405 while (--depth >= 0) {
2406 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2407 break;
2408 path--;
2409 err = ext4_ext_get_access(handle, inode, path);
2410 if (err)
2411 break;
2412 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2413 err = ext4_ext_dirty(handle, inode, path);
2414 if (err)
2415 break;
2416 }
2417 return err;
2418}
2419
2420/*
2421 * ext4_ext_calc_credits_for_single_extent:
2422 * This routine returns max. credits that needed to insert an extent
2423 * to the extent tree.
2424 * When pass the actual path, the caller should calculate credits
2425 * under i_data_sem.
2426 */
2427int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2428 struct ext4_ext_path *path)
2429{
2430 if (path) {
2431 int depth = ext_depth(inode);
2432 int ret = 0;
2433
2434 /* probably there is space in leaf? */
2435 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2436 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2437
2438 /*
2439 * There are some space in the leaf tree, no
2440 * need to account for leaf block credit
2441 *
2442 * bitmaps and block group descriptor blocks
2443 * and other metadata blocks still need to be
2444 * accounted.
2445 */
2446 /* 1 bitmap, 1 block group descriptor */
2447 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2448 return ret;
2449 }
2450 }
2451
2452 return ext4_chunk_trans_blocks(inode, nrblocks);
2453}
2454
2455/*
2456 * How many index/leaf blocks need to change/allocate to add @extents extents?
2457 *
2458 * If we add a single extent, then in the worse case, each tree level
2459 * index/leaf need to be changed in case of the tree split.
2460 *
2461 * If more extents are inserted, they could cause the whole tree split more
2462 * than once, but this is really rare.
2463 */
2464int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2465{
2466 int index;
2467 int depth;
2468
2469 /* If we are converting the inline data, only one is needed here. */
2470 if (ext4_has_inline_data(inode))
2471 return 1;
2472
2473 depth = ext_depth(inode);
2474
2475 if (extents <= 1)
2476 index = depth * 2;
2477 else
2478 index = depth * 3;
2479
2480 return index;
2481}
2482
2483static inline int get_default_free_blocks_flags(struct inode *inode)
2484{
2485 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2486 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2487 else if (ext4_should_journal_data(inode))
2488 return EXT4_FREE_BLOCKS_FORGET;
2489 return 0;
2490}
2491
2492static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2493 struct ext4_extent *ex,
2494 long long *partial_cluster,
2495 ext4_lblk_t from, ext4_lblk_t to)
2496{
2497 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2498 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2499 ext4_fsblk_t pblk;
2500 int flags = get_default_free_blocks_flags(inode);
2501
2502 /*
2503 * For bigalloc file systems, we never free a partial cluster
2504 * at the beginning of the extent. Instead, we make a note
2505 * that we tried freeing the cluster, and check to see if we
2506 * need to free it on a subsequent call to ext4_remove_blocks,
2507 * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
2508 */
2509 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2510
2511 trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2512 /*
2513 * If we have a partial cluster, and it's different from the
2514 * cluster of the last block, we need to explicitly free the
2515 * partial cluster here.
2516 */
2517 pblk = ext4_ext_pblock(ex) + ee_len - 1;
2518 if (*partial_cluster > 0 &&
2519 *partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2520 ext4_free_blocks(handle, inode, NULL,
2521 EXT4_C2B(sbi, *partial_cluster),
2522 sbi->s_cluster_ratio, flags);
2523 *partial_cluster = 0;
2524 }
2525
2526#ifdef EXTENTS_STATS
2527 {
2528 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2529 spin_lock(&sbi->s_ext_stats_lock);
2530 sbi->s_ext_blocks += ee_len;
2531 sbi->s_ext_extents++;
2532 if (ee_len < sbi->s_ext_min)
2533 sbi->s_ext_min = ee_len;
2534 if (ee_len > sbi->s_ext_max)
2535 sbi->s_ext_max = ee_len;
2536 if (ext_depth(inode) > sbi->s_depth_max)
2537 sbi->s_depth_max = ext_depth(inode);
2538 spin_unlock(&sbi->s_ext_stats_lock);
2539 }
2540#endif
2541 if (from >= le32_to_cpu(ex->ee_block)
2542 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2543 /* tail removal */
2544 ext4_lblk_t num;
2545 long long first_cluster;
2546
2547 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2548 pblk = ext4_ext_pblock(ex) + ee_len - num;
2549 /*
2550 * Usually we want to free partial cluster at the end of the
2551 * extent, except for the situation when the cluster is still
2552 * used by any other extent (partial_cluster is negative).
2553 */
2554 if (*partial_cluster < 0 &&
2555 *partial_cluster == -(long long) EXT4_B2C(sbi, pblk+num-1))
2556 flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2557
2558 ext_debug("free last %u blocks starting %llu partial %lld\n",
2559 num, pblk, *partial_cluster);
2560 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2561 /*
2562 * If the block range to be freed didn't start at the
2563 * beginning of a cluster, and we removed the entire
2564 * extent and the cluster is not used by any other extent,
2565 * save the partial cluster here, since we might need to
2566 * delete if we determine that the truncate or punch hole
2567 * operation has removed all of the blocks in the cluster.
2568 * If that cluster is used by another extent, preserve its
2569 * negative value so it isn't freed later on.
2570 *
2571 * If the whole extent wasn't freed, we've reached the
2572 * start of the truncated/punched region and have finished
2573 * removing blocks. If there's a partial cluster here it's
2574 * shared with the remainder of the extent and is no longer
2575 * a candidate for removal.
2576 */
2577 if (EXT4_PBLK_COFF(sbi, pblk) && ee_len == num) {
2578 first_cluster = (long long) EXT4_B2C(sbi, pblk);
2579 if (first_cluster != -*partial_cluster)
2580 *partial_cluster = first_cluster;
2581 } else {
2582 *partial_cluster = 0;
2583 }
2584 } else
2585 ext4_error(sbi->s_sb, "strange request: removal(2) "
2586 "%u-%u from %u:%u\n",
2587 from, to, le32_to_cpu(ex->ee_block), ee_len);
2588 return 0;
2589}
2590
2591
2592/*
2593 * ext4_ext_rm_leaf() Removes the extents associated with the
2594 * blocks appearing between "start" and "end". Both "start"
2595 * and "end" must appear in the same extent or EIO is returned.
2596 *
2597 * @handle: The journal handle
2598 * @inode: The files inode
2599 * @path: The path to the leaf
2600 * @partial_cluster: The cluster which we'll have to free if all extents
2601 * has been released from it. However, if this value is
2602 * negative, it's a cluster just to the right of the
2603 * punched region and it must not be freed.
2604 * @start: The first block to remove
2605 * @end: The last block to remove
2606 */
2607static int
2608ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2609 struct ext4_ext_path *path,
2610 long long *partial_cluster,
2611 ext4_lblk_t start, ext4_lblk_t end)
2612{
2613 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2614 int err = 0, correct_index = 0;
2615 int depth = ext_depth(inode), credits;
2616 struct ext4_extent_header *eh;
2617 ext4_lblk_t a, b;
2618 unsigned num;
2619 ext4_lblk_t ex_ee_block;
2620 unsigned short ex_ee_len;
2621 unsigned unwritten = 0;
2622 struct ext4_extent *ex;
2623 ext4_fsblk_t pblk;
2624
2625 /* the header must be checked already in ext4_ext_remove_space() */
2626 ext_debug("truncate since %u in leaf to %u\n", start, end);
2627 if (!path[depth].p_hdr)
2628 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2629 eh = path[depth].p_hdr;
2630 if (unlikely(path[depth].p_hdr == NULL)) {
2631 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2632 return -EFSCORRUPTED;
2633 }
2634 /* find where to start removing */
2635 ex = path[depth].p_ext;
2636 if (!ex)
2637 ex = EXT_LAST_EXTENT(eh);
2638
2639 ex_ee_block = le32_to_cpu(ex->ee_block);
2640 ex_ee_len = ext4_ext_get_actual_len(ex);
2641
2642 trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2643
2644 while (ex >= EXT_FIRST_EXTENT(eh) &&
2645 ex_ee_block + ex_ee_len > start) {
2646
2647 if (ext4_ext_is_unwritten(ex))
2648 unwritten = 1;
2649 else
2650 unwritten = 0;
2651
2652 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2653 unwritten, ex_ee_len);
2654 path[depth].p_ext = ex;
2655
2656 a = ex_ee_block > start ? ex_ee_block : start;
2657 b = ex_ee_block+ex_ee_len - 1 < end ?
2658 ex_ee_block+ex_ee_len - 1 : end;
2659
2660 ext_debug(" border %u:%u\n", a, b);
2661
2662 /* If this extent is beyond the end of the hole, skip it */
2663 if (end < ex_ee_block) {
2664 /*
2665 * We're going to skip this extent and move to another,
2666 * so note that its first cluster is in use to avoid
2667 * freeing it when removing blocks. Eventually, the
2668 * right edge of the truncated/punched region will
2669 * be just to the left.
2670 */
2671 if (sbi->s_cluster_ratio > 1) {
2672 pblk = ext4_ext_pblock(ex);
2673 *partial_cluster =
2674 -(long long) EXT4_B2C(sbi, pblk);
2675 }
2676 ex--;
2677 ex_ee_block = le32_to_cpu(ex->ee_block);
2678 ex_ee_len = ext4_ext_get_actual_len(ex);
2679 continue;
2680 } else if (b != ex_ee_block + ex_ee_len - 1) {
2681 EXT4_ERROR_INODE(inode,
2682 "can not handle truncate %u:%u "
2683 "on extent %u:%u",
2684 start, end, ex_ee_block,
2685 ex_ee_block + ex_ee_len - 1);
2686 err = -EFSCORRUPTED;
2687 goto out;
2688 } else if (a != ex_ee_block) {
2689 /* remove tail of the extent */
2690 num = a - ex_ee_block;
2691 } else {
2692 /* remove whole extent: excellent! */
2693 num = 0;
2694 }
2695 /*
2696 * 3 for leaf, sb, and inode plus 2 (bmap and group
2697 * descriptor) for each block group; assume two block
2698 * groups plus ex_ee_len/blocks_per_block_group for
2699 * the worst case
2700 */
2701 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2702 if (ex == EXT_FIRST_EXTENT(eh)) {
2703 correct_index = 1;
2704 credits += (ext_depth(inode)) + 1;
2705 }
2706 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2707
2708 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2709 if (err)
2710 goto out;
2711
2712 err = ext4_ext_get_access(handle, inode, path + depth);
2713 if (err)
2714 goto out;
2715
2716 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2717 a, b);
2718 if (err)
2719 goto out;
2720
2721 if (num == 0)
2722 /* this extent is removed; mark slot entirely unused */
2723 ext4_ext_store_pblock(ex, 0);
2724
2725 ex->ee_len = cpu_to_le16(num);
2726 /*
2727 * Do not mark unwritten if all the blocks in the
2728 * extent have been removed.
2729 */
2730 if (unwritten && num)
2731 ext4_ext_mark_unwritten(ex);
2732 /*
2733 * If the extent was completely released,
2734 * we need to remove it from the leaf
2735 */
2736 if (num == 0) {
2737 if (end != EXT_MAX_BLOCKS - 1) {
2738 /*
2739 * For hole punching, we need to scoot all the
2740 * extents up when an extent is removed so that
2741 * we dont have blank extents in the middle
2742 */
2743 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2744 sizeof(struct ext4_extent));
2745
2746 /* Now get rid of the one at the end */
2747 memset(EXT_LAST_EXTENT(eh), 0,
2748 sizeof(struct ext4_extent));
2749 }
2750 le16_add_cpu(&eh->eh_entries, -1);
2751 }
2752
2753 err = ext4_ext_dirty(handle, inode, path + depth);
2754 if (err)
2755 goto out;
2756
2757 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2758 ext4_ext_pblock(ex));
2759 ex--;
2760 ex_ee_block = le32_to_cpu(ex->ee_block);
2761 ex_ee_len = ext4_ext_get_actual_len(ex);
2762 }
2763
2764 if (correct_index && eh->eh_entries)
2765 err = ext4_ext_correct_indexes(handle, inode, path);
2766
2767 /*
2768 * If there's a partial cluster and at least one extent remains in
2769 * the leaf, free the partial cluster if it isn't shared with the
2770 * current extent. If it is shared with the current extent
2771 * we zero partial_cluster because we've reached the start of the
2772 * truncated/punched region and we're done removing blocks.
2773 */
2774 if (*partial_cluster > 0 && ex >= EXT_FIRST_EXTENT(eh)) {
2775 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
2776 if (*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2777 ext4_free_blocks(handle, inode, NULL,
2778 EXT4_C2B(sbi, *partial_cluster),
2779 sbi->s_cluster_ratio,
2780 get_default_free_blocks_flags(inode));
2781 }
2782 *partial_cluster = 0;
2783 }
2784
2785 /* if this leaf is free, then we should
2786 * remove it from index block above */
2787 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2788 err = ext4_ext_rm_idx(handle, inode, path, depth);
2789
2790out:
2791 return err;
2792}
2793
2794/*
2795 * ext4_ext_more_to_rm:
2796 * returns 1 if current index has to be freed (even partial)
2797 */
2798static int
2799ext4_ext_more_to_rm(struct ext4_ext_path *path)
2800{
2801 BUG_ON(path->p_idx == NULL);
2802
2803 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2804 return 0;
2805
2806 /*
2807 * if truncate on deeper level happened, it wasn't partial,
2808 * so we have to consider current index for truncation
2809 */
2810 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2811 return 0;
2812 return 1;
2813}
2814
2815int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2816 ext4_lblk_t end)
2817{
2818 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2819 int depth = ext_depth(inode);
2820 struct ext4_ext_path *path = NULL;
2821 long long partial_cluster = 0;
2822 handle_t *handle;
2823 int i = 0, err = 0;
2824
2825 ext_debug("truncate since %u to %u\n", start, end);
2826
2827 /* probably first extent we're gonna free will be last in block */
2828 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1);
2829 if (IS_ERR(handle))
2830 return PTR_ERR(handle);
2831
2832again:
2833 trace_ext4_ext_remove_space(inode, start, end, depth);
2834
2835 /*
2836 * Check if we are removing extents inside the extent tree. If that
2837 * is the case, we are going to punch a hole inside the extent tree
2838 * so we have to check whether we need to split the extent covering
2839 * the last block to remove so we can easily remove the part of it
2840 * in ext4_ext_rm_leaf().
2841 */
2842 if (end < EXT_MAX_BLOCKS - 1) {
2843 struct ext4_extent *ex;
2844 ext4_lblk_t ee_block, ex_end, lblk;
2845 ext4_fsblk_t pblk;
2846
2847 /* find extent for or closest extent to this block */
2848 path = ext4_find_extent(inode, end, NULL, EXT4_EX_NOCACHE);
2849 if (IS_ERR(path)) {
2850 ext4_journal_stop(handle);
2851 return PTR_ERR(path);
2852 }
2853 depth = ext_depth(inode);
2854 /* Leaf not may not exist only if inode has no blocks at all */
2855 ex = path[depth].p_ext;
2856 if (!ex) {
2857 if (depth) {
2858 EXT4_ERROR_INODE(inode,
2859 "path[%d].p_hdr == NULL",
2860 depth);
2861 err = -EFSCORRUPTED;
2862 }
2863 goto out;
2864 }
2865
2866 ee_block = le32_to_cpu(ex->ee_block);
2867 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
2868
2869 /*
2870 * See if the last block is inside the extent, if so split
2871 * the extent at 'end' block so we can easily remove the
2872 * tail of the first part of the split extent in
2873 * ext4_ext_rm_leaf().
2874 */
2875 if (end >= ee_block && end < ex_end) {
2876
2877 /*
2878 * If we're going to split the extent, note that
2879 * the cluster containing the block after 'end' is
2880 * in use to avoid freeing it when removing blocks.
2881 */
2882 if (sbi->s_cluster_ratio > 1) {
2883 pblk = ext4_ext_pblock(ex) + end - ee_block + 2;
2884 partial_cluster =
2885 -(long long) EXT4_B2C(sbi, pblk);
2886 }
2887
2888 /*
2889 * Split the extent in two so that 'end' is the last
2890 * block in the first new extent. Also we should not
2891 * fail removing space due to ENOSPC so try to use
2892 * reserved block if that happens.
2893 */
2894 err = ext4_force_split_extent_at(handle, inode, &path,
2895 end + 1, 1);
2896 if (err < 0)
2897 goto out;
2898
2899 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end) {
2900 /*
2901 * If there's an extent to the right its first cluster
2902 * contains the immediate right boundary of the
2903 * truncated/punched region. Set partial_cluster to
2904 * its negative value so it won't be freed if shared
2905 * with the current extent. The end < ee_block case
2906 * is handled in ext4_ext_rm_leaf().
2907 */
2908 lblk = ex_end + 1;
2909 err = ext4_ext_search_right(inode, path, &lblk, &pblk,
2910 &ex);
2911 if (err)
2912 goto out;
2913 if (pblk)
2914 partial_cluster =
2915 -(long long) EXT4_B2C(sbi, pblk);
2916 }
2917 }
2918 /*
2919 * We start scanning from right side, freeing all the blocks
2920 * after i_size and walking into the tree depth-wise.
2921 */
2922 depth = ext_depth(inode);
2923 if (path) {
2924 int k = i = depth;
2925 while (--k > 0)
2926 path[k].p_block =
2927 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2928 } else {
2929 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2930 GFP_NOFS);
2931 if (path == NULL) {
2932 ext4_journal_stop(handle);
2933 return -ENOMEM;
2934 }
2935 path[0].p_maxdepth = path[0].p_depth = depth;
2936 path[0].p_hdr = ext_inode_hdr(inode);
2937 i = 0;
2938
2939 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2940 err = -EFSCORRUPTED;
2941 goto out;
2942 }
2943 }
2944 err = 0;
2945
2946 while (i >= 0 && err == 0) {
2947 if (i == depth) {
2948 /* this is leaf block */
2949 err = ext4_ext_rm_leaf(handle, inode, path,
2950 &partial_cluster, start,
2951 end);
2952 /* root level has p_bh == NULL, brelse() eats this */
2953 brelse(path[i].p_bh);
2954 path[i].p_bh = NULL;
2955 i--;
2956 continue;
2957 }
2958
2959 /* this is index block */
2960 if (!path[i].p_hdr) {
2961 ext_debug("initialize header\n");
2962 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2963 }
2964
2965 if (!path[i].p_idx) {
2966 /* this level hasn't been touched yet */
2967 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2968 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2969 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2970 path[i].p_hdr,
2971 le16_to_cpu(path[i].p_hdr->eh_entries));
2972 } else {
2973 /* we were already here, see at next index */
2974 path[i].p_idx--;
2975 }
2976
2977 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2978 i, EXT_FIRST_INDEX(path[i].p_hdr),
2979 path[i].p_idx);
2980 if (ext4_ext_more_to_rm(path + i)) {
2981 struct buffer_head *bh;
2982 /* go to the next level */
2983 ext_debug("move to level %d (block %llu)\n",
2984 i + 1, ext4_idx_pblock(path[i].p_idx));
2985 memset(path + i + 1, 0, sizeof(*path));
2986 bh = read_extent_tree_block(inode,
2987 ext4_idx_pblock(path[i].p_idx), depth - i - 1,
2988 EXT4_EX_NOCACHE);
2989 if (IS_ERR(bh)) {
2990 /* should we reset i_size? */
2991 err = PTR_ERR(bh);
2992 break;
2993 }
2994 /* Yield here to deal with large extent trees.
2995 * Should be a no-op if we did IO above. */
2996 cond_resched();
2997 if (WARN_ON(i + 1 > depth)) {
2998 err = -EFSCORRUPTED;
2999 break;
3000 }
3001 path[i + 1].p_bh = bh;
3002
3003 /* save actual number of indexes since this
3004 * number is changed at the next iteration */
3005 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
3006 i++;
3007 } else {
3008 /* we finished processing this index, go up */
3009 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
3010 /* index is empty, remove it;
3011 * handle must be already prepared by the
3012 * truncatei_leaf() */
3013 err = ext4_ext_rm_idx(handle, inode, path, i);
3014 }
3015 /* root level has p_bh == NULL, brelse() eats this */
3016 brelse(path[i].p_bh);
3017 path[i].p_bh = NULL;
3018 i--;
3019 ext_debug("return to level %d\n", i);
3020 }
3021 }
3022
3023 trace_ext4_ext_remove_space_done(inode, start, end, depth,
3024 partial_cluster, path->p_hdr->eh_entries);
3025
3026 /*
3027 * If we still have something in the partial cluster and we have removed
3028 * even the first extent, then we should free the blocks in the partial
3029 * cluster as well. (This code will only run when there are no leaves
3030 * to the immediate left of the truncated/punched region.)
3031 */
3032 if (partial_cluster > 0 && err == 0) {
3033 /* don't zero partial_cluster since it's not used afterwards */
3034 ext4_free_blocks(handle, inode, NULL,
3035 EXT4_C2B(sbi, partial_cluster),
3036 sbi->s_cluster_ratio,
3037 get_default_free_blocks_flags(inode));
3038 }
3039
3040 /* TODO: flexible tree reduction should be here */
3041 if (path->p_hdr->eh_entries == 0) {
3042 /*
3043 * truncate to zero freed all the tree,
3044 * so we need to correct eh_depth
3045 */
3046 err = ext4_ext_get_access(handle, inode, path);
3047 if (err == 0) {
3048 ext_inode_hdr(inode)->eh_depth = 0;
3049 ext_inode_hdr(inode)->eh_max =
3050 cpu_to_le16(ext4_ext_space_root(inode, 0));
3051 err = ext4_ext_dirty(handle, inode, path);
3052 }
3053 }
3054out:
3055 ext4_ext_drop_refs(path);
3056 kfree(path);
3057 path = NULL;
3058 if (err == -EAGAIN)
3059 goto again;
3060 ext4_journal_stop(handle);
3061
3062 return err;
3063}
3064
3065/*
3066 * called at mount time
3067 */
3068void ext4_ext_init(struct super_block *sb)
3069{
3070 /*
3071 * possible initialization would be here
3072 */
3073
3074 if (ext4_has_feature_extents(sb)) {
3075#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
3076 printk(KERN_INFO "EXT4-fs: file extents enabled"
3077#ifdef AGGRESSIVE_TEST
3078 ", aggressive tests"
3079#endif
3080#ifdef CHECK_BINSEARCH
3081 ", check binsearch"
3082#endif
3083#ifdef EXTENTS_STATS
3084 ", stats"
3085#endif
3086 "\n");
3087#endif
3088#ifdef EXTENTS_STATS
3089 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3090 EXT4_SB(sb)->s_ext_min = 1 << 30;
3091 EXT4_SB(sb)->s_ext_max = 0;
3092#endif
3093 }
3094}
3095
3096/*
3097 * called at umount time
3098 */
3099void ext4_ext_release(struct super_block *sb)
3100{
3101 if (!ext4_has_feature_extents(sb))
3102 return;
3103
3104#ifdef EXTENTS_STATS
3105 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3106 struct ext4_sb_info *sbi = EXT4_SB(sb);
3107 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3108 sbi->s_ext_blocks, sbi->s_ext_extents,
3109 sbi->s_ext_blocks / sbi->s_ext_extents);
3110 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3111 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3112 }
3113#endif
3114}
3115
3116static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3117{
3118 ext4_lblk_t ee_block;
3119 ext4_fsblk_t ee_pblock;
3120 unsigned int ee_len;
3121
3122 ee_block = le32_to_cpu(ex->ee_block);
3123 ee_len = ext4_ext_get_actual_len(ex);
3124 ee_pblock = ext4_ext_pblock(ex);
3125
3126 if (ee_len == 0)
3127 return 0;
3128
3129 return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3130 EXTENT_STATUS_WRITTEN);
3131}
3132
3133/* FIXME!! we need to try to merge to left or right after zero-out */
3134static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3135{
3136 ext4_fsblk_t ee_pblock;
3137 unsigned int ee_len;
3138
3139 ee_len = ext4_ext_get_actual_len(ex);
3140 ee_pblock = ext4_ext_pblock(ex);
3141 return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock,
3142 ee_len);
3143}
3144
3145/*
3146 * ext4_split_extent_at() splits an extent at given block.
3147 *
3148 * @handle: the journal handle
3149 * @inode: the file inode
3150 * @path: the path to the extent
3151 * @split: the logical block where the extent is splitted.
3152 * @split_flags: indicates if the extent could be zeroout if split fails, and
3153 * the states(init or unwritten) of new extents.
3154 * @flags: flags used to insert new extent to extent tree.
3155 *
3156 *
3157 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3158 * of which are deterimined by split_flag.
3159 *
3160 * There are two cases:
3161 * a> the extent are splitted into two extent.
3162 * b> split is not needed, and just mark the extent.
3163 *
3164 * return 0 on success.
3165 */
3166static int ext4_split_extent_at(handle_t *handle,
3167 struct inode *inode,
3168 struct ext4_ext_path **ppath,
3169 ext4_lblk_t split,
3170 int split_flag,
3171 int flags)
3172{
3173 struct ext4_ext_path *path = *ppath;
3174 ext4_fsblk_t newblock;
3175 ext4_lblk_t ee_block;
3176 struct ext4_extent *ex, newex, orig_ex, zero_ex;
3177 struct ext4_extent *ex2 = NULL;
3178 unsigned int ee_len, depth;
3179 int err = 0;
3180
3181 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3182 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3183
3184 ext_debug("ext4_split_extents_at: inode %lu, logical"
3185 "block %llu\n", inode->i_ino, (unsigned long long)split);
3186
3187 ext4_ext_show_leaf(inode, path);
3188
3189 depth = ext_depth(inode);
3190 ex = path[depth].p_ext;
3191 ee_block = le32_to_cpu(ex->ee_block);
3192 ee_len = ext4_ext_get_actual_len(ex);
3193 newblock = split - ee_block + ext4_ext_pblock(ex);
3194
3195 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3196 BUG_ON(!ext4_ext_is_unwritten(ex) &&
3197 split_flag & (EXT4_EXT_MAY_ZEROOUT |
3198 EXT4_EXT_MARK_UNWRIT1 |
3199 EXT4_EXT_MARK_UNWRIT2));
3200
3201 err = ext4_ext_get_access(handle, inode, path + depth);
3202 if (err)
3203 goto out;
3204
3205 if (split == ee_block) {
3206 /*
3207 * case b: block @split is the block that the extent begins with
3208 * then we just change the state of the extent, and splitting
3209 * is not needed.
3210 */
3211 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3212 ext4_ext_mark_unwritten(ex);
3213 else
3214 ext4_ext_mark_initialized(ex);
3215
3216 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3217 ext4_ext_try_to_merge(handle, inode, path, ex);
3218
3219 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3220 goto out;
3221 }
3222
3223 /* case a */
3224 memcpy(&orig_ex, ex, sizeof(orig_ex));
3225 ex->ee_len = cpu_to_le16(split - ee_block);
3226 if (split_flag & EXT4_EXT_MARK_UNWRIT1)
3227 ext4_ext_mark_unwritten(ex);
3228
3229 /*
3230 * path may lead to new leaf, not to original leaf any more
3231 * after ext4_ext_insert_extent() returns,
3232 */
3233 err = ext4_ext_dirty(handle, inode, path + depth);
3234 if (err)
3235 goto fix_extent_len;
3236
3237 ex2 = &newex;
3238 ex2->ee_block = cpu_to_le32(split);
3239 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
3240 ext4_ext_store_pblock(ex2, newblock);
3241 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3242 ext4_ext_mark_unwritten(ex2);
3243
3244 err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
3245 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3246 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3247 if (split_flag & EXT4_EXT_DATA_VALID1) {
3248 err = ext4_ext_zeroout(inode, ex2);
3249 zero_ex.ee_block = ex2->ee_block;
3250 zero_ex.ee_len = cpu_to_le16(
3251 ext4_ext_get_actual_len(ex2));
3252 ext4_ext_store_pblock(&zero_ex,
3253 ext4_ext_pblock(ex2));
3254 } else {
3255 err = ext4_ext_zeroout(inode, ex);
3256 zero_ex.ee_block = ex->ee_block;
3257 zero_ex.ee_len = cpu_to_le16(
3258 ext4_ext_get_actual_len(ex));
3259 ext4_ext_store_pblock(&zero_ex,
3260 ext4_ext_pblock(ex));
3261 }
3262 } else {
3263 err = ext4_ext_zeroout(inode, &orig_ex);
3264 zero_ex.ee_block = orig_ex.ee_block;
3265 zero_ex.ee_len = cpu_to_le16(
3266 ext4_ext_get_actual_len(&orig_ex));
3267 ext4_ext_store_pblock(&zero_ex,
3268 ext4_ext_pblock(&orig_ex));
3269 }
3270
3271 if (err)
3272 goto fix_extent_len;
3273 /* update the extent length and mark as initialized */
3274 ex->ee_len = cpu_to_le16(ee_len);
3275 ext4_ext_try_to_merge(handle, inode, path, ex);
3276 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3277 if (err)
3278 goto fix_extent_len;
3279
3280 /* update extent status tree */
3281 err = ext4_zeroout_es(inode, &zero_ex);
3282
3283 goto out;
3284 } else if (err)
3285 goto fix_extent_len;
3286
3287out:
3288 ext4_ext_show_leaf(inode, path);
3289 return err;
3290
3291fix_extent_len:
3292 ex->ee_len = orig_ex.ee_len;
3293 ext4_ext_dirty(handle, inode, path + path->p_depth);
3294 return err;
3295}
3296
3297/*
3298 * ext4_split_extents() splits an extent and mark extent which is covered
3299 * by @map as split_flags indicates
3300 *
3301 * It may result in splitting the extent into multiple extents (up to three)
3302 * There are three possibilities:
3303 * a> There is no split required
3304 * b> Splits in two extents: Split is happening at either end of the extent
3305 * c> Splits in three extents: Somone is splitting in middle of the extent
3306 *
3307 */
3308static int ext4_split_extent(handle_t *handle,
3309 struct inode *inode,
3310 struct ext4_ext_path **ppath,
3311 struct ext4_map_blocks *map,
3312 int split_flag,
3313 int flags)
3314{
3315 struct ext4_ext_path *path = *ppath;
3316 ext4_lblk_t ee_block;
3317 struct ext4_extent *ex;
3318 unsigned int ee_len, depth;
3319 int err = 0;
3320 int unwritten;
3321 int split_flag1, flags1;
3322 int allocated = map->m_len;
3323
3324 depth = ext_depth(inode);
3325 ex = path[depth].p_ext;
3326 ee_block = le32_to_cpu(ex->ee_block);
3327 ee_len = ext4_ext_get_actual_len(ex);
3328 unwritten = ext4_ext_is_unwritten(ex);
3329
3330 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3331 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3332 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3333 if (unwritten)
3334 split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
3335 EXT4_EXT_MARK_UNWRIT2;
3336 if (split_flag & EXT4_EXT_DATA_VALID2)
3337 split_flag1 |= EXT4_EXT_DATA_VALID1;
3338 err = ext4_split_extent_at(handle, inode, ppath,
3339 map->m_lblk + map->m_len, split_flag1, flags1);
3340 if (err)
3341 goto out;
3342 } else {
3343 allocated = ee_len - (map->m_lblk - ee_block);
3344 }
3345 /*
3346 * Update path is required because previous ext4_split_extent_at() may
3347 * result in split of original leaf or extent zeroout.
3348 */
3349 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3350 if (IS_ERR(path))
3351 return PTR_ERR(path);
3352 depth = ext_depth(inode);
3353 ex = path[depth].p_ext;
3354 if (!ex) {
3355 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3356 (unsigned long) map->m_lblk);
3357 return -EFSCORRUPTED;
3358 }
3359 unwritten = ext4_ext_is_unwritten(ex);
3360 split_flag1 = 0;
3361
3362 if (map->m_lblk >= ee_block) {
3363 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3364 if (unwritten) {
3365 split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
3366 split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3367 EXT4_EXT_MARK_UNWRIT2);
3368 }
3369 err = ext4_split_extent_at(handle, inode, ppath,
3370 map->m_lblk, split_flag1, flags);
3371 if (err)
3372 goto out;
3373 }
3374
3375 ext4_ext_show_leaf(inode, path);
3376out:
3377 return err ? err : allocated;
3378}
3379
3380/*
3381 * This function is called by ext4_ext_map_blocks() if someone tries to write
3382 * to an unwritten extent. It may result in splitting the unwritten
3383 * extent into multiple extents (up to three - one initialized and two
3384 * unwritten).
3385 * There are three possibilities:
3386 * a> There is no split required: Entire extent should be initialized
3387 * b> Splits in two extents: Write is happening at either end of the extent
3388 * c> Splits in three extents: Somone is writing in middle of the extent
3389 *
3390 * Pre-conditions:
3391 * - The extent pointed to by 'path' is unwritten.
3392 * - The extent pointed to by 'path' contains a superset
3393 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3394 *
3395 * Post-conditions on success:
3396 * - the returned value is the number of blocks beyond map->l_lblk
3397 * that are allocated and initialized.
3398 * It is guaranteed to be >= map->m_len.
3399 */
3400static int ext4_ext_convert_to_initialized(handle_t *handle,
3401 struct inode *inode,
3402 struct ext4_map_blocks *map,
3403 struct ext4_ext_path **ppath,
3404 int flags)
3405{
3406 struct ext4_ext_path *path = *ppath;
3407 struct ext4_sb_info *sbi;
3408 struct ext4_extent_header *eh;
3409 struct ext4_map_blocks split_map;
3410 struct ext4_extent zero_ex;
3411 struct ext4_extent *ex, *abut_ex;
3412 ext4_lblk_t ee_block, eof_block;
3413 unsigned int ee_len, depth, map_len = map->m_len;
3414 int allocated = 0, max_zeroout = 0;
3415 int err = 0;
3416 int split_flag = 0;
3417
3418 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3419 "block %llu, max_blocks %u\n", inode->i_ino,
3420 (unsigned long long)map->m_lblk, map_len);
3421
3422 sbi = EXT4_SB(inode->i_sb);
3423 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3424 inode->i_sb->s_blocksize_bits;
3425 if (eof_block < map->m_lblk + map_len)
3426 eof_block = map->m_lblk + map_len;
3427
3428 depth = ext_depth(inode);
3429 eh = path[depth].p_hdr;
3430 ex = path[depth].p_ext;
3431 ee_block = le32_to_cpu(ex->ee_block);
3432 ee_len = ext4_ext_get_actual_len(ex);
3433 zero_ex.ee_len = 0;
3434
3435 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3436
3437 /* Pre-conditions */
3438 BUG_ON(!ext4_ext_is_unwritten(ex));
3439 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3440
3441 /*
3442 * Attempt to transfer newly initialized blocks from the currently
3443 * unwritten extent to its neighbor. This is much cheaper
3444 * than an insertion followed by a merge as those involve costly
3445 * memmove() calls. Transferring to the left is the common case in
3446 * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3447 * followed by append writes.
3448 *
3449 * Limitations of the current logic:
3450 * - L1: we do not deal with writes covering the whole extent.
3451 * This would require removing the extent if the transfer
3452 * is possible.
3453 * - L2: we only attempt to merge with an extent stored in the
3454 * same extent tree node.
3455 */
3456 if ((map->m_lblk == ee_block) &&
3457 /* See if we can merge left */
3458 (map_len < ee_len) && /*L1*/
3459 (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/
3460 ext4_lblk_t prev_lblk;
3461 ext4_fsblk_t prev_pblk, ee_pblk;
3462 unsigned int prev_len;
3463
3464 abut_ex = ex - 1;
3465 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3466 prev_len = ext4_ext_get_actual_len(abut_ex);
3467 prev_pblk = ext4_ext_pblock(abut_ex);
3468 ee_pblk = ext4_ext_pblock(ex);
3469
3470 /*
3471 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3472 * upon those conditions:
3473 * - C1: abut_ex is initialized,
3474 * - C2: abut_ex is logically abutting ex,
3475 * - C3: abut_ex is physically abutting ex,
3476 * - C4: abut_ex can receive the additional blocks without
3477 * overflowing the (initialized) length limit.
3478 */
3479 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3480 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3481 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3482 (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3483 err = ext4_ext_get_access(handle, inode, path + depth);
3484 if (err)
3485 goto out;
3486
3487 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3488 map, ex, abut_ex);
3489
3490 /* Shift the start of ex by 'map_len' blocks */
3491 ex->ee_block = cpu_to_le32(ee_block + map_len);
3492 ext4_ext_store_pblock(ex, ee_pblk + map_len);
3493 ex->ee_len = cpu_to_le16(ee_len - map_len);
3494 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3495
3496 /* Extend abut_ex by 'map_len' blocks */
3497 abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3498
3499 /* Result: number of initialized blocks past m_lblk */
3500 allocated = map_len;
3501 }
3502 } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3503 (map_len < ee_len) && /*L1*/
3504 ex < EXT_LAST_EXTENT(eh)) { /*L2*/
3505 /* See if we can merge right */
3506 ext4_lblk_t next_lblk;
3507 ext4_fsblk_t next_pblk, ee_pblk;
3508 unsigned int next_len;
3509
3510 abut_ex = ex + 1;
3511 next_lblk = le32_to_cpu(abut_ex->ee_block);
3512 next_len = ext4_ext_get_actual_len(abut_ex);
3513 next_pblk = ext4_ext_pblock(abut_ex);
3514 ee_pblk = ext4_ext_pblock(ex);
3515
3516 /*
3517 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3518 * upon those conditions:
3519 * - C1: abut_ex is initialized,
3520 * - C2: abut_ex is logically abutting ex,
3521 * - C3: abut_ex is physically abutting ex,
3522 * - C4: abut_ex can receive the additional blocks without
3523 * overflowing the (initialized) length limit.
3524 */
3525 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3526 ((map->m_lblk + map_len) == next_lblk) && /*C2*/
3527 ((ee_pblk + ee_len) == next_pblk) && /*C3*/
3528 (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3529 err = ext4_ext_get_access(handle, inode, path + depth);
3530 if (err)
3531 goto out;
3532
3533 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3534 map, ex, abut_ex);
3535
3536 /* Shift the start of abut_ex by 'map_len' blocks */
3537 abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3538 ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3539 ex->ee_len = cpu_to_le16(ee_len - map_len);
3540 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3541
3542 /* Extend abut_ex by 'map_len' blocks */
3543 abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3544
3545 /* Result: number of initialized blocks past m_lblk */
3546 allocated = map_len;
3547 }
3548 }
3549 if (allocated) {
3550 /* Mark the block containing both extents as dirty */
3551 ext4_ext_dirty(handle, inode, path + depth);
3552
3553 /* Update path to point to the right extent */
3554 path[depth].p_ext = abut_ex;
3555 goto out;
3556 } else
3557 allocated = ee_len - (map->m_lblk - ee_block);
3558
3559 WARN_ON(map->m_lblk < ee_block);
3560 /*
3561 * It is safe to convert extent to initialized via explicit
3562 * zeroout only if extent is fully inside i_size or new_size.
3563 */
3564 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3565
3566 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3567 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3568 (inode->i_sb->s_blocksize_bits - 10);
3569
3570 if (ext4_encrypted_inode(inode))
3571 max_zeroout = 0;
3572
3573 /* If extent is less than s_max_zeroout_kb, zeroout directly */
3574 if (max_zeroout && (ee_len <= max_zeroout)) {
3575 err = ext4_ext_zeroout(inode, ex);
3576 if (err)
3577 goto out;
3578 zero_ex.ee_block = ex->ee_block;
3579 zero_ex.ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex));
3580 ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex));
3581
3582 err = ext4_ext_get_access(handle, inode, path + depth);
3583 if (err)
3584 goto out;
3585 ext4_ext_mark_initialized(ex);
3586 ext4_ext_try_to_merge(handle, inode, path, ex);
3587 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3588 goto out;
3589 }
3590
3591 /*
3592 * four cases:
3593 * 1. split the extent into three extents.
3594 * 2. split the extent into two extents, zeroout the first half.
3595 * 3. split the extent into two extents, zeroout the second half.
3596 * 4. split the extent into two extents with out zeroout.
3597 */
3598 split_map.m_lblk = map->m_lblk;
3599 split_map.m_len = map->m_len;
3600
3601 if (max_zeroout && (allocated > map->m_len)) {
3602 if (allocated <= max_zeroout) {
3603 /* case 3 */
3604 zero_ex.ee_block =
3605 cpu_to_le32(map->m_lblk);
3606 zero_ex.ee_len = cpu_to_le16(allocated);
3607 ext4_ext_store_pblock(&zero_ex,
3608 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
3609 err = ext4_ext_zeroout(inode, &zero_ex);
3610 if (err)
3611 goto out;
3612 split_map.m_lblk = map->m_lblk;
3613 split_map.m_len = allocated;
3614 } else if (map->m_lblk - ee_block + map->m_len < max_zeroout) {
3615 /* case 2 */
3616 if (map->m_lblk != ee_block) {
3617 zero_ex.ee_block = ex->ee_block;
3618 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
3619 ee_block);
3620 ext4_ext_store_pblock(&zero_ex,
3621 ext4_ext_pblock(ex));
3622 err = ext4_ext_zeroout(inode, &zero_ex);
3623 if (err)
3624 goto out;
3625 }
3626
3627 split_map.m_lblk = ee_block;
3628 split_map.m_len = map->m_lblk - ee_block + map->m_len;
3629 allocated = map->m_len;
3630 }
3631 }
3632
3633 err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
3634 flags);
3635 if (err > 0)
3636 err = 0;
3637out:
3638 /* If we have gotten a failure, don't zero out status tree */
3639 if (!err)
3640 err = ext4_zeroout_es(inode, &zero_ex);
3641 return err ? err : allocated;
3642}
3643
3644/*
3645 * This function is called by ext4_ext_map_blocks() from
3646 * ext4_get_blocks_dio_write() when DIO to write
3647 * to an unwritten extent.
3648 *
3649 * Writing to an unwritten extent may result in splitting the unwritten
3650 * extent into multiple initialized/unwritten extents (up to three)
3651 * There are three possibilities:
3652 * a> There is no split required: Entire extent should be unwritten
3653 * b> Splits in two extents: Write is happening at either end of the extent
3654 * c> Splits in three extents: Somone is writing in middle of the extent
3655 *
3656 * This works the same way in the case of initialized -> unwritten conversion.
3657 *
3658 * One of more index blocks maybe needed if the extent tree grow after
3659 * the unwritten extent split. To prevent ENOSPC occur at the IO
3660 * complete, we need to split the unwritten extent before DIO submit
3661 * the IO. The unwritten extent called at this time will be split
3662 * into three unwritten extent(at most). After IO complete, the part
3663 * being filled will be convert to initialized by the end_io callback function
3664 * via ext4_convert_unwritten_extents().
3665 *
3666 * Returns the size of unwritten extent to be written on success.
3667 */
3668static int ext4_split_convert_extents(handle_t *handle,
3669 struct inode *inode,
3670 struct ext4_map_blocks *map,
3671 struct ext4_ext_path **ppath,
3672 int flags)
3673{
3674 struct ext4_ext_path *path = *ppath;
3675 ext4_lblk_t eof_block;
3676 ext4_lblk_t ee_block;
3677 struct ext4_extent *ex;
3678 unsigned int ee_len;
3679 int split_flag = 0, depth;
3680
3681 ext_debug("%s: inode %lu, logical block %llu, max_blocks %u\n",
3682 __func__, inode->i_ino,
3683 (unsigned long long)map->m_lblk, map->m_len);
3684
3685 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3686 inode->i_sb->s_blocksize_bits;
3687 if (eof_block < map->m_lblk + map->m_len)
3688 eof_block = map->m_lblk + map->m_len;
3689 /*
3690 * It is safe to convert extent to initialized via explicit
3691 * zeroout only if extent is fully insde i_size or new_size.
3692 */
3693 depth = ext_depth(inode);
3694 ex = path[depth].p_ext;
3695 ee_block = le32_to_cpu(ex->ee_block);
3696 ee_len = ext4_ext_get_actual_len(ex);
3697
3698 /* Convert to unwritten */
3699 if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
3700 split_flag |= EXT4_EXT_DATA_VALID1;
3701 /* Convert to initialized */
3702 } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
3703 split_flag |= ee_block + ee_len <= eof_block ?
3704 EXT4_EXT_MAY_ZEROOUT : 0;
3705 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
3706 }
3707 flags |= EXT4_GET_BLOCKS_PRE_IO;
3708 return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
3709}
3710
3711static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3712 struct inode *inode,
3713 struct ext4_map_blocks *map,
3714 struct ext4_ext_path **ppath)
3715{
3716 struct ext4_ext_path *path = *ppath;
3717 struct ext4_extent *ex;
3718 ext4_lblk_t ee_block;
3719 unsigned int ee_len;
3720 int depth;
3721 int err = 0;
3722
3723 depth = ext_depth(inode);
3724 ex = path[depth].p_ext;
3725 ee_block = le32_to_cpu(ex->ee_block);
3726 ee_len = ext4_ext_get_actual_len(ex);
3727
3728 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3729 "block %llu, max_blocks %u\n", inode->i_ino,
3730 (unsigned long long)ee_block, ee_len);
3731
3732 /* If extent is larger than requested it is a clear sign that we still
3733 * have some extent state machine issues left. So extent_split is still
3734 * required.
3735 * TODO: Once all related issues will be fixed this situation should be
3736 * illegal.
3737 */
3738 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3739#ifdef EXT4_DEBUG
3740 ext4_warning("Inode (%ld) finished: extent logical block %llu,"
3741 " len %u; IO logical block %llu, len %u\n",
3742 inode->i_ino, (unsigned long long)ee_block, ee_len,
3743 (unsigned long long)map->m_lblk, map->m_len);
3744#endif
3745 err = ext4_split_convert_extents(handle, inode, map, ppath,
3746 EXT4_GET_BLOCKS_CONVERT);
3747 if (err < 0)
3748 return err;
3749 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3750 if (IS_ERR(path))
3751 return PTR_ERR(path);
3752 depth = ext_depth(inode);
3753 ex = path[depth].p_ext;
3754 }
3755
3756 err = ext4_ext_get_access(handle, inode, path + depth);
3757 if (err)
3758 goto out;
3759 /* first mark the extent as initialized */
3760 ext4_ext_mark_initialized(ex);
3761
3762 /* note: ext4_ext_correct_indexes() isn't needed here because
3763 * borders are not changed
3764 */
3765 ext4_ext_try_to_merge(handle, inode, path, ex);
3766
3767 /* Mark modified extent as dirty */
3768 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3769out:
3770 ext4_ext_show_leaf(inode, path);
3771 return err;
3772}
3773
3774static void unmap_underlying_metadata_blocks(struct block_device *bdev,
3775 sector_t block, int count)
3776{
3777 int i;
3778 for (i = 0; i < count; i++)
3779 unmap_underlying_metadata(bdev, block + i);
3780}
3781
3782/*
3783 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3784 */
3785static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3786 ext4_lblk_t lblk,
3787 struct ext4_ext_path *path,
3788 unsigned int len)
3789{
3790 int i, depth;
3791 struct ext4_extent_header *eh;
3792 struct ext4_extent *last_ex;
3793
3794 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3795 return 0;
3796
3797 depth = ext_depth(inode);
3798 eh = path[depth].p_hdr;
3799
3800 /*
3801 * We're going to remove EOFBLOCKS_FL entirely in future so we
3802 * do not care for this case anymore. Simply remove the flag
3803 * if there are no extents.
3804 */
3805 if (unlikely(!eh->eh_entries))
3806 goto out;
3807 last_ex = EXT_LAST_EXTENT(eh);
3808 /*
3809 * We should clear the EOFBLOCKS_FL flag if we are writing the
3810 * last block in the last extent in the file. We test this by
3811 * first checking to see if the caller to
3812 * ext4_ext_get_blocks() was interested in the last block (or
3813 * a block beyond the last block) in the current extent. If
3814 * this turns out to be false, we can bail out from this
3815 * function immediately.
3816 */
3817 if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3818 ext4_ext_get_actual_len(last_ex))
3819 return 0;
3820 /*
3821 * If the caller does appear to be planning to write at or
3822 * beyond the end of the current extent, we then test to see
3823 * if the current extent is the last extent in the file, by
3824 * checking to make sure it was reached via the rightmost node
3825 * at each level of the tree.
3826 */
3827 for (i = depth-1; i >= 0; i--)
3828 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3829 return 0;
3830out:
3831 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3832 return ext4_mark_inode_dirty(handle, inode);
3833}
3834
3835/**
3836 * ext4_find_delalloc_range: find delayed allocated block in the given range.
3837 *
3838 * Return 1 if there is a delalloc block in the range, otherwise 0.
3839 */
3840int ext4_find_delalloc_range(struct inode *inode,
3841 ext4_lblk_t lblk_start,
3842 ext4_lblk_t lblk_end)
3843{
3844 struct extent_status es;
3845
3846 ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es);
3847 if (es.es_len == 0)
3848 return 0; /* there is no delay extent in this tree */
3849 else if (es.es_lblk <= lblk_start &&
3850 lblk_start < es.es_lblk + es.es_len)
3851 return 1;
3852 else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end)
3853 return 1;
3854 else
3855 return 0;
3856}
3857
3858int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
3859{
3860 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3861 ext4_lblk_t lblk_start, lblk_end;
3862 lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
3863 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3864
3865 return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
3866}
3867
3868/**
3869 * Determines how many complete clusters (out of those specified by the 'map')
3870 * are under delalloc and were reserved quota for.
3871 * This function is called when we are writing out the blocks that were
3872 * originally written with their allocation delayed, but then the space was
3873 * allocated using fallocate() before the delayed allocation could be resolved.
3874 * The cases to look for are:
3875 * ('=' indicated delayed allocated blocks
3876 * '-' indicates non-delayed allocated blocks)
3877 * (a) partial clusters towards beginning and/or end outside of allocated range
3878 * are not delalloc'ed.
3879 * Ex:
3880 * |----c---=|====c====|====c====|===-c----|
3881 * |++++++ allocated ++++++|
3882 * ==> 4 complete clusters in above example
3883 *
3884 * (b) partial cluster (outside of allocated range) towards either end is
3885 * marked for delayed allocation. In this case, we will exclude that
3886 * cluster.
3887 * Ex:
3888 * |----====c========|========c========|
3889 * |++++++ allocated ++++++|
3890 * ==> 1 complete clusters in above example
3891 *
3892 * Ex:
3893 * |================c================|
3894 * |++++++ allocated ++++++|
3895 * ==> 0 complete clusters in above example
3896 *
3897 * The ext4_da_update_reserve_space will be called only if we
3898 * determine here that there were some "entire" clusters that span
3899 * this 'allocated' range.
3900 * In the non-bigalloc case, this function will just end up returning num_blks
3901 * without ever calling ext4_find_delalloc_range.
3902 */
3903static unsigned int
3904get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3905 unsigned int num_blks)
3906{
3907 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3908 ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3909 ext4_lblk_t lblk_from, lblk_to, c_offset;
3910 unsigned int allocated_clusters = 0;
3911
3912 alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3913 alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3914
3915 /* max possible clusters for this allocation */
3916 allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3917
3918 trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3919
3920 /* Check towards left side */
3921 c_offset = EXT4_LBLK_COFF(sbi, lblk_start);
3922 if (c_offset) {
3923 lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start);
3924 lblk_to = lblk_from + c_offset - 1;
3925
3926 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3927 allocated_clusters--;
3928 }
3929
3930 /* Now check towards right. */
3931 c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks);
3932 if (allocated_clusters && c_offset) {
3933 lblk_from = lblk_start + num_blks;
3934 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3935
3936 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3937 allocated_clusters--;
3938 }
3939
3940 return allocated_clusters;
3941}
3942
3943static int
3944convert_initialized_extent(handle_t *handle, struct inode *inode,
3945 struct ext4_map_blocks *map,
3946 struct ext4_ext_path **ppath,
3947 unsigned int allocated)
3948{
3949 struct ext4_ext_path *path = *ppath;
3950 struct ext4_extent *ex;
3951 ext4_lblk_t ee_block;
3952 unsigned int ee_len;
3953 int depth;
3954 int err = 0;
3955
3956 /*
3957 * Make sure that the extent is no bigger than we support with
3958 * unwritten extent
3959 */
3960 if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
3961 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
3962
3963 depth = ext_depth(inode);
3964 ex = path[depth].p_ext;
3965 ee_block = le32_to_cpu(ex->ee_block);
3966 ee_len = ext4_ext_get_actual_len(ex);
3967
3968 ext_debug("%s: inode %lu, logical"
3969 "block %llu, max_blocks %u\n", __func__, inode->i_ino,
3970 (unsigned long long)ee_block, ee_len);
3971
3972 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3973 err = ext4_split_convert_extents(handle, inode, map, ppath,
3974 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
3975 if (err < 0)
3976 return err;
3977 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3978 if (IS_ERR(path))
3979 return PTR_ERR(path);
3980 depth = ext_depth(inode);
3981 ex = path[depth].p_ext;
3982 if (!ex) {
3983 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3984 (unsigned long) map->m_lblk);
3985 return -EFSCORRUPTED;
3986 }
3987 }
3988
3989 err = ext4_ext_get_access(handle, inode, path + depth);
3990 if (err)
3991 return err;
3992 /* first mark the extent as unwritten */
3993 ext4_ext_mark_unwritten(ex);
3994
3995 /* note: ext4_ext_correct_indexes() isn't needed here because
3996 * borders are not changed
3997 */
3998 ext4_ext_try_to_merge(handle, inode, path, ex);
3999
4000 /* Mark modified extent as dirty */
4001 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
4002 if (err)
4003 return err;
4004 ext4_ext_show_leaf(inode, path);
4005
4006 ext4_update_inode_fsync_trans(handle, inode, 1);
4007 err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len);
4008 if (err)
4009 return err;
4010 map->m_flags |= EXT4_MAP_UNWRITTEN;
4011 if (allocated > map->m_len)
4012 allocated = map->m_len;
4013 map->m_len = allocated;
4014 return allocated;
4015}
4016
4017static int
4018ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
4019 struct ext4_map_blocks *map,
4020 struct ext4_ext_path **ppath, int flags,
4021 unsigned int allocated, ext4_fsblk_t newblock)
4022{
4023 struct ext4_ext_path *path = *ppath;
4024 int ret = 0;
4025 int err = 0;
4026
4027 ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical "
4028 "block %llu, max_blocks %u, flags %x, allocated %u\n",
4029 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
4030 flags, allocated);
4031 ext4_ext_show_leaf(inode, path);
4032
4033 /*
4034 * When writing into unwritten space, we should not fail to
4035 * allocate metadata blocks for the new extent block if needed.
4036 */
4037 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
4038
4039 trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
4040 allocated, newblock);
4041
4042 /* get_block() before submit the IO, split the extent */
4043 if (flags & EXT4_GET_BLOCKS_PRE_IO) {
4044 ret = ext4_split_convert_extents(handle, inode, map, ppath,
4045 flags | EXT4_GET_BLOCKS_CONVERT);
4046 if (ret <= 0)
4047 goto out;
4048 map->m_flags |= EXT4_MAP_UNWRITTEN;
4049 goto out;
4050 }
4051 /* IO end_io complete, convert the filled extent to written */
4052 if (flags & EXT4_GET_BLOCKS_CONVERT) {
4053 if (flags & EXT4_GET_BLOCKS_ZERO) {
4054 if (allocated > map->m_len)
4055 allocated = map->m_len;
4056 err = ext4_issue_zeroout(inode, map->m_lblk, newblock,
4057 allocated);
4058 if (err < 0)
4059 goto out2;
4060 }
4061 ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
4062 ppath);
4063 if (ret >= 0) {
4064 ext4_update_inode_fsync_trans(handle, inode, 1);
4065 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4066 path, map->m_len);
4067 } else
4068 err = ret;
4069 map->m_flags |= EXT4_MAP_MAPPED;
4070 map->m_pblk = newblock;
4071 if (allocated > map->m_len)
4072 allocated = map->m_len;
4073 map->m_len = allocated;
4074 goto out2;
4075 }
4076 /* buffered IO case */
4077 /*
4078 * repeat fallocate creation request
4079 * we already have an unwritten extent
4080 */
4081 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
4082 map->m_flags |= EXT4_MAP_UNWRITTEN;
4083 goto map_out;
4084 }
4085
4086 /* buffered READ or buffered write_begin() lookup */
4087 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4088 /*
4089 * We have blocks reserved already. We
4090 * return allocated blocks so that delalloc
4091 * won't do block reservation for us. But
4092 * the buffer head will be unmapped so that
4093 * a read from the block returns 0s.
4094 */
4095 map->m_flags |= EXT4_MAP_UNWRITTEN;
4096 goto out1;
4097 }
4098
4099 /* buffered write, writepage time, convert*/
4100 ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags);
4101 if (ret >= 0)
4102 ext4_update_inode_fsync_trans(handle, inode, 1);
4103out:
4104 if (ret <= 0) {
4105 err = ret;
4106 goto out2;
4107 } else
4108 allocated = ret;
4109 map->m_flags |= EXT4_MAP_NEW;
4110 /*
4111 * if we allocated more blocks than requested
4112 * we need to make sure we unmap the extra block
4113 * allocated. The actual needed block will get
4114 * unmapped later when we find the buffer_head marked
4115 * new.
4116 */
4117 if (allocated > map->m_len) {
4118 unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
4119 newblock + map->m_len,
4120 allocated - map->m_len);
4121 allocated = map->m_len;
4122 }
4123 map->m_len = allocated;
4124
4125 /*
4126 * If we have done fallocate with the offset that is already
4127 * delayed allocated, we would have block reservation
4128 * and quota reservation done in the delayed write path.
4129 * But fallocate would have already updated quota and block
4130 * count for this offset. So cancel these reservation
4131 */
4132 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4133 unsigned int reserved_clusters;
4134 reserved_clusters = get_reserved_cluster_alloc(inode,
4135 map->m_lblk, map->m_len);
4136 if (reserved_clusters)
4137 ext4_da_update_reserve_space(inode,
4138 reserved_clusters,
4139 0);
4140 }
4141
4142map_out:
4143 map->m_flags |= EXT4_MAP_MAPPED;
4144 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
4145 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
4146 map->m_len);
4147 if (err < 0)
4148 goto out2;
4149 }
4150out1:
4151 if (allocated > map->m_len)
4152 allocated = map->m_len;
4153 ext4_ext_show_leaf(inode, path);
4154 map->m_pblk = newblock;
4155 map->m_len = allocated;
4156out2:
4157 return err ? err : allocated;
4158}
4159
4160/*
4161 * get_implied_cluster_alloc - check to see if the requested
4162 * allocation (in the map structure) overlaps with a cluster already
4163 * allocated in an extent.
4164 * @sb The filesystem superblock structure
4165 * @map The requested lblk->pblk mapping
4166 * @ex The extent structure which might contain an implied
4167 * cluster allocation
4168 *
4169 * This function is called by ext4_ext_map_blocks() after we failed to
4170 * find blocks that were already in the inode's extent tree. Hence,
4171 * we know that the beginning of the requested region cannot overlap
4172 * the extent from the inode's extent tree. There are three cases we
4173 * want to catch. The first is this case:
4174 *
4175 * |--- cluster # N--|
4176 * |--- extent ---| |---- requested region ---|
4177 * |==========|
4178 *
4179 * The second case that we need to test for is this one:
4180 *
4181 * |--------- cluster # N ----------------|
4182 * |--- requested region --| |------- extent ----|
4183 * |=======================|
4184 *
4185 * The third case is when the requested region lies between two extents
4186 * within the same cluster:
4187 * |------------- cluster # N-------------|
4188 * |----- ex -----| |---- ex_right ----|
4189 * |------ requested region ------|
4190 * |================|
4191 *
4192 * In each of the above cases, we need to set the map->m_pblk and
4193 * map->m_len so it corresponds to the return the extent labelled as
4194 * "|====|" from cluster #N, since it is already in use for data in
4195 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
4196 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
4197 * as a new "allocated" block region. Otherwise, we will return 0 and
4198 * ext4_ext_map_blocks() will then allocate one or more new clusters
4199 * by calling ext4_mb_new_blocks().
4200 */
4201static int get_implied_cluster_alloc(struct super_block *sb,
4202 struct ext4_map_blocks *map,
4203 struct ext4_extent *ex,
4204 struct ext4_ext_path *path)
4205{
4206 struct ext4_sb_info *sbi = EXT4_SB(sb);
4207 ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4208 ext4_lblk_t ex_cluster_start, ex_cluster_end;
4209 ext4_lblk_t rr_cluster_start;
4210 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4211 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4212 unsigned short ee_len = ext4_ext_get_actual_len(ex);
4213
4214 /* The extent passed in that we are trying to match */
4215 ex_cluster_start = EXT4_B2C(sbi, ee_block);
4216 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
4217
4218 /* The requested region passed into ext4_map_blocks() */
4219 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
4220
4221 if ((rr_cluster_start == ex_cluster_end) ||
4222 (rr_cluster_start == ex_cluster_start)) {
4223 if (rr_cluster_start == ex_cluster_end)
4224 ee_start += ee_len - 1;
4225 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
4226 map->m_len = min(map->m_len,
4227 (unsigned) sbi->s_cluster_ratio - c_offset);
4228 /*
4229 * Check for and handle this case:
4230 *
4231 * |--------- cluster # N-------------|
4232 * |------- extent ----|
4233 * |--- requested region ---|
4234 * |===========|
4235 */
4236
4237 if (map->m_lblk < ee_block)
4238 map->m_len = min(map->m_len, ee_block - map->m_lblk);
4239
4240 /*
4241 * Check for the case where there is already another allocated
4242 * block to the right of 'ex' but before the end of the cluster.
4243 *
4244 * |------------- cluster # N-------------|
4245 * |----- ex -----| |---- ex_right ----|
4246 * |------ requested region ------|
4247 * |================|
4248 */
4249 if (map->m_lblk > ee_block) {
4250 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4251 map->m_len = min(map->m_len, next - map->m_lblk);
4252 }
4253
4254 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4255 return 1;
4256 }
4257
4258 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4259 return 0;
4260}
4261
4262
4263/*
4264 * Block allocation/map/preallocation routine for extents based files
4265 *
4266 *
4267 * Need to be called with
4268 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4269 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4270 *
4271 * return > 0, number of of blocks already mapped/allocated
4272 * if create == 0 and these are pre-allocated blocks
4273 * buffer head is unmapped
4274 * otherwise blocks are mapped
4275 *
4276 * return = 0, if plain look up failed (blocks have not been allocated)
4277 * buffer head is unmapped
4278 *
4279 * return < 0, error case.
4280 */
4281int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4282 struct ext4_map_blocks *map, int flags)
4283{
4284 struct ext4_ext_path *path = NULL;
4285 struct ext4_extent newex, *ex, *ex2;
4286 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4287 ext4_fsblk_t newblock = 0;
4288 int free_on_err = 0, err = 0, depth, ret;
4289 unsigned int allocated = 0, offset = 0;
4290 unsigned int allocated_clusters = 0;
4291 struct ext4_allocation_request ar;
4292 ext4_lblk_t cluster_offset;
4293 bool map_from_cluster = false;
4294
4295 ext_debug("blocks %u/%u requested for inode %lu\n",
4296 map->m_lblk, map->m_len, inode->i_ino);
4297 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4298
4299 /* find extent for this block */
4300 path = ext4_find_extent(inode, map->m_lblk, NULL, 0);
4301 if (IS_ERR(path)) {
4302 err = PTR_ERR(path);
4303 path = NULL;
4304 goto out2;
4305 }
4306
4307 depth = ext_depth(inode);
4308
4309 /*
4310 * consistent leaf must not be empty;
4311 * this situation is possible, though, _during_ tree modification;
4312 * this is why assert can't be put in ext4_find_extent()
4313 */
4314 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4315 EXT4_ERROR_INODE(inode, "bad extent address "
4316 "lblock: %lu, depth: %d pblock %lld",
4317 (unsigned long) map->m_lblk, depth,
4318 path[depth].p_block);
4319 err = -EFSCORRUPTED;
4320 goto out2;
4321 }
4322
4323 ex = path[depth].p_ext;
4324 if (ex) {
4325 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4326 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4327 unsigned short ee_len;
4328
4329
4330 /*
4331 * unwritten extents are treated as holes, except that
4332 * we split out initialized portions during a write.
4333 */
4334 ee_len = ext4_ext_get_actual_len(ex);
4335
4336 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4337
4338 /* if found extent covers block, simply return it */
4339 if (in_range(map->m_lblk, ee_block, ee_len)) {
4340 newblock = map->m_lblk - ee_block + ee_start;
4341 /* number of remaining blocks in the extent */
4342 allocated = ee_len - (map->m_lblk - ee_block);
4343 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
4344 ee_block, ee_len, newblock);
4345
4346 /*
4347 * If the extent is initialized check whether the
4348 * caller wants to convert it to unwritten.
4349 */
4350 if ((!ext4_ext_is_unwritten(ex)) &&
4351 (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
4352 allocated = convert_initialized_extent(
4353 handle, inode, map, &path,
4354 allocated);
4355 goto out2;
4356 } else if (!ext4_ext_is_unwritten(ex))
4357 goto out;
4358
4359 ret = ext4_ext_handle_unwritten_extents(
4360 handle, inode, map, &path, flags,
4361 allocated, newblock);
4362 if (ret < 0)
4363 err = ret;
4364 else
4365 allocated = ret;
4366 goto out2;
4367 }
4368 }
4369
4370 /*
4371 * requested block isn't allocated yet;
4372 * we couldn't try to create block if create flag is zero
4373 */
4374 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4375 ext4_lblk_t hole_start, hole_len;
4376
4377 hole_start = map->m_lblk;
4378 hole_len = ext4_ext_determine_hole(inode, path, &hole_start);
4379 /*
4380 * put just found gap into cache to speed up
4381 * subsequent requests
4382 */
4383 ext4_ext_put_gap_in_cache(inode, hole_start, hole_len);
4384
4385 /* Update hole_len to reflect hole size after map->m_lblk */
4386 if (hole_start != map->m_lblk)
4387 hole_len -= map->m_lblk - hole_start;
4388 map->m_pblk = 0;
4389 map->m_len = min_t(unsigned int, map->m_len, hole_len);
4390
4391 goto out2;
4392 }
4393
4394 /*
4395 * Okay, we need to do block allocation.
4396 */
4397 newex.ee_block = cpu_to_le32(map->m_lblk);
4398 cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4399
4400 /*
4401 * If we are doing bigalloc, check to see if the extent returned
4402 * by ext4_find_extent() implies a cluster we can use.
4403 */
4404 if (cluster_offset && ex &&
4405 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4406 ar.len = allocated = map->m_len;
4407 newblock = map->m_pblk;
4408 map_from_cluster = true;
4409 goto got_allocated_blocks;
4410 }
4411
4412 /* find neighbour allocated blocks */
4413 ar.lleft = map->m_lblk;
4414 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4415 if (err)
4416 goto out2;
4417 ar.lright = map->m_lblk;
4418 ex2 = NULL;
4419 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4420 if (err)
4421 goto out2;
4422
4423 /* Check if the extent after searching to the right implies a
4424 * cluster we can use. */
4425 if ((sbi->s_cluster_ratio > 1) && ex2 &&
4426 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
4427 ar.len = allocated = map->m_len;
4428 newblock = map->m_pblk;
4429 map_from_cluster = true;
4430 goto got_allocated_blocks;
4431 }
4432
4433 /*
4434 * See if request is beyond maximum number of blocks we can have in
4435 * a single extent. For an initialized extent this limit is
4436 * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
4437 * EXT_UNWRITTEN_MAX_LEN.
4438 */
4439 if (map->m_len > EXT_INIT_MAX_LEN &&
4440 !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4441 map->m_len = EXT_INIT_MAX_LEN;
4442 else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
4443 (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4444 map->m_len = EXT_UNWRITTEN_MAX_LEN;
4445
4446 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4447 newex.ee_len = cpu_to_le16(map->m_len);
4448 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4449 if (err)
4450 allocated = ext4_ext_get_actual_len(&newex);
4451 else
4452 allocated = map->m_len;
4453
4454 /* allocate new block */
4455 ar.inode = inode;
4456 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4457 ar.logical = map->m_lblk;
4458 /*
4459 * We calculate the offset from the beginning of the cluster
4460 * for the logical block number, since when we allocate a
4461 * physical cluster, the physical block should start at the
4462 * same offset from the beginning of the cluster. This is
4463 * needed so that future calls to get_implied_cluster_alloc()
4464 * work correctly.
4465 */
4466 offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4467 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4468 ar.goal -= offset;
4469 ar.logical -= offset;
4470 if (S_ISREG(inode->i_mode))
4471 ar.flags = EXT4_MB_HINT_DATA;
4472 else
4473 /* disable in-core preallocation for non-regular files */
4474 ar.flags = 0;
4475 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4476 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4477 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4478 ar.flags |= EXT4_MB_DELALLOC_RESERVED;
4479 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
4480 ar.flags |= EXT4_MB_USE_RESERVED;
4481 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4482 if (!newblock)
4483 goto out2;
4484 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4485 ar.goal, newblock, allocated);
4486 free_on_err = 1;
4487 allocated_clusters = ar.len;
4488 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4489 if (ar.len > allocated)
4490 ar.len = allocated;
4491
4492got_allocated_blocks:
4493 /* try to insert new extent into found leaf and return */
4494 ext4_ext_store_pblock(&newex, newblock + offset);
4495 newex.ee_len = cpu_to_le16(ar.len);
4496 /* Mark unwritten */
4497 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){
4498 ext4_ext_mark_unwritten(&newex);
4499 map->m_flags |= EXT4_MAP_UNWRITTEN;
4500 }
4501
4502 err = 0;
4503 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4504 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4505 path, ar.len);
4506 if (!err)
4507 err = ext4_ext_insert_extent(handle, inode, &path,
4508 &newex, flags);
4509
4510 if (err && free_on_err) {
4511 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4512 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4513 /* free data blocks we just allocated */
4514 /* not a good idea to call discard here directly,
4515 * but otherwise we'd need to call it every free() */
4516 ext4_discard_preallocations(inode);
4517 ext4_free_blocks(handle, inode, NULL, newblock,
4518 EXT4_C2B(sbi, allocated_clusters), fb_flags);
4519 goto out2;
4520 }
4521
4522 /* previous routine could use block we allocated */
4523 newblock = ext4_ext_pblock(&newex);
4524 allocated = ext4_ext_get_actual_len(&newex);
4525 if (allocated > map->m_len)
4526 allocated = map->m_len;
4527 map->m_flags |= EXT4_MAP_NEW;
4528
4529 /*
4530 * Update reserved blocks/metadata blocks after successful
4531 * block allocation which had been deferred till now.
4532 */
4533 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4534 unsigned int reserved_clusters;
4535 /*
4536 * Check how many clusters we had reserved this allocated range
4537 */
4538 reserved_clusters = get_reserved_cluster_alloc(inode,
4539 map->m_lblk, allocated);
4540 if (!map_from_cluster) {
4541 BUG_ON(allocated_clusters < reserved_clusters);
4542 if (reserved_clusters < allocated_clusters) {
4543 struct ext4_inode_info *ei = EXT4_I(inode);
4544 int reservation = allocated_clusters -
4545 reserved_clusters;
4546 /*
4547 * It seems we claimed few clusters outside of
4548 * the range of this allocation. We should give
4549 * it back to the reservation pool. This can
4550 * happen in the following case:
4551 *
4552 * * Suppose s_cluster_ratio is 4 (i.e., each
4553 * cluster has 4 blocks. Thus, the clusters
4554 * are [0-3],[4-7],[8-11]...
4555 * * First comes delayed allocation write for
4556 * logical blocks 10 & 11. Since there were no
4557 * previous delayed allocated blocks in the
4558 * range [8-11], we would reserve 1 cluster
4559 * for this write.
4560 * * Next comes write for logical blocks 3 to 8.
4561 * In this case, we will reserve 2 clusters
4562 * (for [0-3] and [4-7]; and not for [8-11] as
4563 * that range has a delayed allocated blocks.
4564 * Thus total reserved clusters now becomes 3.
4565 * * Now, during the delayed allocation writeout
4566 * time, we will first write blocks [3-8] and
4567 * allocate 3 clusters for writing these
4568 * blocks. Also, we would claim all these
4569 * three clusters above.
4570 * * Now when we come here to writeout the
4571 * blocks [10-11], we would expect to claim
4572 * the reservation of 1 cluster we had made
4573 * (and we would claim it since there are no
4574 * more delayed allocated blocks in the range
4575 * [8-11]. But our reserved cluster count had
4576 * already gone to 0.
4577 *
4578 * Thus, at the step 4 above when we determine
4579 * that there are still some unwritten delayed
4580 * allocated blocks outside of our current
4581 * block range, we should increment the
4582 * reserved clusters count so that when the
4583 * remaining blocks finally gets written, we
4584 * could claim them.
4585 */
4586 dquot_reserve_block(inode,
4587 EXT4_C2B(sbi, reservation));
4588 spin_lock(&ei->i_block_reservation_lock);
4589 ei->i_reserved_data_blocks += reservation;
4590 spin_unlock(&ei->i_block_reservation_lock);
4591 }
4592 /*
4593 * We will claim quota for all newly allocated blocks.
4594 * We're updating the reserved space *after* the
4595 * correction above so we do not accidentally free
4596 * all the metadata reservation because we might
4597 * actually need it later on.
4598 */
4599 ext4_da_update_reserve_space(inode, allocated_clusters,
4600 1);
4601 }
4602 }
4603
4604 /*
4605 * Cache the extent and update transaction to commit on fdatasync only
4606 * when it is _not_ an unwritten extent.
4607 */
4608 if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
4609 ext4_update_inode_fsync_trans(handle, inode, 1);
4610 else
4611 ext4_update_inode_fsync_trans(handle, inode, 0);
4612out:
4613 if (allocated > map->m_len)
4614 allocated = map->m_len;
4615 ext4_ext_show_leaf(inode, path);
4616 map->m_flags |= EXT4_MAP_MAPPED;
4617 map->m_pblk = newblock;
4618 map->m_len = allocated;
4619out2:
4620 ext4_ext_drop_refs(path);
4621 kfree(path);
4622
4623 trace_ext4_ext_map_blocks_exit(inode, flags, map,
4624 err ? err : allocated);
4625 return err ? err : allocated;
4626}
4627
4628void ext4_ext_truncate(handle_t *handle, struct inode *inode)
4629{
4630 struct super_block *sb = inode->i_sb;
4631 ext4_lblk_t last_block;
4632 int err = 0;
4633
4634 /*
4635 * TODO: optimization is possible here.
4636 * Probably we need not scan at all,
4637 * because page truncation is enough.
4638 */
4639
4640 /* we have to know where to truncate from in crash case */
4641 EXT4_I(inode)->i_disksize = inode->i_size;
4642 ext4_mark_inode_dirty(handle, inode);
4643
4644 last_block = (inode->i_size + sb->s_blocksize - 1)
4645 >> EXT4_BLOCK_SIZE_BITS(sb);
4646retry:
4647 err = ext4_es_remove_extent(inode, last_block,
4648 EXT_MAX_BLOCKS - last_block);
4649 if (err == -ENOMEM) {
4650 cond_resched();
4651 congestion_wait(BLK_RW_ASYNC, HZ/50);
4652 goto retry;
4653 }
4654 if (err) {
4655 ext4_std_error(inode->i_sb, err);
4656 return;
4657 }
4658 err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4659 ext4_std_error(inode->i_sb, err);
4660}
4661
4662static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
4663 ext4_lblk_t len, loff_t new_size,
4664 int flags, int mode)
4665{
4666 struct inode *inode = file_inode(file);
4667 handle_t *handle;
4668 int ret = 0;
4669 int ret2 = 0;
4670 int retries = 0;
4671 int depth = 0;
4672 struct ext4_map_blocks map;
4673 unsigned int credits;
4674 loff_t epos;
4675
4676 map.m_lblk = offset;
4677 map.m_len = len;
4678 /*
4679 * Don't normalize the request if it can fit in one extent so
4680 * that it doesn't get unnecessarily split into multiple
4681 * extents.
4682 */
4683 if (len <= EXT_UNWRITTEN_MAX_LEN)
4684 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4685
4686 /*
4687 * credits to insert 1 extent into extent tree
4688 */
4689 credits = ext4_chunk_trans_blocks(inode, len);
4690 /*
4691 * We can only call ext_depth() on extent based inodes
4692 */
4693 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
4694 depth = ext_depth(inode);
4695 else
4696 depth = -1;
4697
4698retry:
4699 while (ret >= 0 && len) {
4700 /*
4701 * Recalculate credits when extent tree depth changes.
4702 */
4703 if (depth >= 0 && depth != ext_depth(inode)) {
4704 credits = ext4_chunk_trans_blocks(inode, len);
4705 depth = ext_depth(inode);
4706 }
4707
4708 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4709 credits);
4710 if (IS_ERR(handle)) {
4711 ret = PTR_ERR(handle);
4712 break;
4713 }
4714 ret = ext4_map_blocks(handle, inode, &map, flags);
4715 if (ret <= 0) {
4716 ext4_debug("inode #%lu: block %u: len %u: "
4717 "ext4_ext_map_blocks returned %d",
4718 inode->i_ino, map.m_lblk,
4719 map.m_len, ret);
4720 ext4_mark_inode_dirty(handle, inode);
4721 ret2 = ext4_journal_stop(handle);
4722 break;
4723 }
4724 map.m_lblk += ret;
4725 map.m_len = len = len - ret;
4726 epos = (loff_t)map.m_lblk << inode->i_blkbits;
4727 inode->i_ctime = ext4_current_time(inode);
4728 if (new_size) {
4729 if (epos > new_size)
4730 epos = new_size;
4731 if (ext4_update_inode_size(inode, epos) & 0x1)
4732 inode->i_mtime = inode->i_ctime;
4733 } else {
4734 if (epos > inode->i_size)
4735 ext4_set_inode_flag(inode,
4736 EXT4_INODE_EOFBLOCKS);
4737 }
4738 ext4_mark_inode_dirty(handle, inode);
4739 ret2 = ext4_journal_stop(handle);
4740 if (ret2)
4741 break;
4742 }
4743 if (ret == -ENOSPC &&
4744 ext4_should_retry_alloc(inode->i_sb, &retries)) {
4745 ret = 0;
4746 goto retry;
4747 }
4748
4749 return ret > 0 ? ret2 : ret;
4750}
4751
4752static long ext4_zero_range(struct file *file, loff_t offset,
4753 loff_t len, int mode)
4754{
4755 struct inode *inode = file_inode(file);
4756 handle_t *handle = NULL;
4757 unsigned int max_blocks;
4758 loff_t new_size = 0;
4759 int ret = 0;
4760 int flags;
4761 int credits;
4762 int partial_begin, partial_end;
4763 loff_t start, end;
4764 ext4_lblk_t lblk;
4765 unsigned int blkbits = inode->i_blkbits;
4766
4767 trace_ext4_zero_range(inode, offset, len, mode);
4768
4769 if (!S_ISREG(inode->i_mode))
4770 return -EINVAL;
4771
4772 /* Call ext4_force_commit to flush all data in case of data=journal. */
4773 if (ext4_should_journal_data(inode)) {
4774 ret = ext4_force_commit(inode->i_sb);
4775 if (ret)
4776 return ret;
4777 }
4778
4779 /*
4780 * Round up offset. This is not fallocate, we neet to zero out
4781 * blocks, so convert interior block aligned part of the range to
4782 * unwritten and possibly manually zero out unaligned parts of the
4783 * range.
4784 */
4785 start = round_up(offset, 1 << blkbits);
4786 end = round_down((offset + len), 1 << blkbits);
4787
4788 if (start < offset || end > offset + len)
4789 return -EINVAL;
4790 partial_begin = offset & ((1 << blkbits) - 1);
4791 partial_end = (offset + len) & ((1 << blkbits) - 1);
4792
4793 lblk = start >> blkbits;
4794 max_blocks = (end >> blkbits);
4795 if (max_blocks < lblk)
4796 max_blocks = 0;
4797 else
4798 max_blocks -= lblk;
4799
4800 inode_lock(inode);
4801
4802 /*
4803 * Indirect files do not support unwritten extnets
4804 */
4805 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4806 ret = -EOPNOTSUPP;
4807 goto out_mutex;
4808 }
4809
4810 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4811 offset + len > i_size_read(inode)) {
4812 new_size = offset + len;
4813 ret = inode_newsize_ok(inode, new_size);
4814 if (ret)
4815 goto out_mutex;
4816 }
4817
4818 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4819 if (mode & FALLOC_FL_KEEP_SIZE)
4820 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4821
4822 /* Wait all existing dio workers, newcomers will block on i_mutex */
4823 ext4_inode_block_unlocked_dio(inode);
4824 inode_dio_wait(inode);
4825
4826 /* Preallocate the range including the unaligned edges */
4827 if (partial_begin || partial_end) {
4828 ret = ext4_alloc_file_blocks(file,
4829 round_down(offset, 1 << blkbits) >> blkbits,
4830 (round_up((offset + len), 1 << blkbits) -
4831 round_down(offset, 1 << blkbits)) >> blkbits,
4832 new_size, flags, mode);
4833 if (ret)
4834 goto out_dio;
4835
4836 }
4837
4838 /* Zero range excluding the unaligned edges */
4839 if (max_blocks > 0) {
4840 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
4841 EXT4_EX_NOCACHE);
4842
4843 /*
4844 * Prevent page faults from reinstantiating pages we have
4845 * released from page cache.
4846 */
4847 down_write(&EXT4_I(inode)->i_mmap_sem);
4848 ret = ext4_update_disksize_before_punch(inode, offset, len);
4849 if (ret) {
4850 up_write(&EXT4_I(inode)->i_mmap_sem);
4851 goto out_dio;
4852 }
4853 /* Now release the pages and zero block aligned part of pages */
4854 truncate_pagecache_range(inode, start, end - 1);
4855 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4856
4857 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4858 flags, mode);
4859 up_write(&EXT4_I(inode)->i_mmap_sem);
4860 if (ret)
4861 goto out_dio;
4862 }
4863 if (!partial_begin && !partial_end)
4864 goto out_dio;
4865
4866 /*
4867 * In worst case we have to writeout two nonadjacent unwritten
4868 * blocks and update the inode
4869 */
4870 credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
4871 if (ext4_should_journal_data(inode))
4872 credits += 2;
4873 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
4874 if (IS_ERR(handle)) {
4875 ret = PTR_ERR(handle);
4876 ext4_std_error(inode->i_sb, ret);
4877 goto out_dio;
4878 }
4879
4880 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4881 if (new_size) {
4882 ext4_update_inode_size(inode, new_size);
4883 } else {
4884 /*
4885 * Mark that we allocate beyond EOF so the subsequent truncate
4886 * can proceed even if the new size is the same as i_size.
4887 */
4888 if ((offset + len) > i_size_read(inode))
4889 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4890 }
4891 ext4_mark_inode_dirty(handle, inode);
4892
4893 /* Zero out partial block at the edges of the range */
4894 ret = ext4_zero_partial_blocks(handle, inode, offset, len);
4895
4896 if (file->f_flags & O_SYNC)
4897 ext4_handle_sync(handle);
4898
4899 ext4_journal_stop(handle);
4900out_dio:
4901 ext4_inode_resume_unlocked_dio(inode);
4902out_mutex:
4903 inode_unlock(inode);
4904 return ret;
4905}
4906
4907/*
4908 * preallocate space for a file. This implements ext4's fallocate file
4909 * operation, which gets called from sys_fallocate system call.
4910 * For block-mapped files, posix_fallocate should fall back to the method
4911 * of writing zeroes to the required new blocks (the same behavior which is
4912 * expected for file systems which do not support fallocate() system call).
4913 */
4914long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4915{
4916 struct inode *inode = file_inode(file);
4917 loff_t new_size = 0;
4918 unsigned int max_blocks;
4919 int ret = 0;
4920 int flags;
4921 ext4_lblk_t lblk;
4922 unsigned int blkbits = inode->i_blkbits;
4923
4924 /*
4925 * Encrypted inodes can't handle collapse range or insert
4926 * range since we would need to re-encrypt blocks with a
4927 * different IV or XTS tweak (which are based on the logical
4928 * block number).
4929 *
4930 * XXX It's not clear why zero range isn't working, but we'll
4931 * leave it disabled for encrypted inodes for now. This is a
4932 * bug we should fix....
4933 */
4934 if (ext4_encrypted_inode(inode) &&
4935 (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE |
4936 FALLOC_FL_ZERO_RANGE)))
4937 return -EOPNOTSUPP;
4938
4939 /* Return error if mode is not supported */
4940 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
4941 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
4942 FALLOC_FL_INSERT_RANGE))
4943 return -EOPNOTSUPP;
4944
4945 if (mode & FALLOC_FL_PUNCH_HOLE)
4946 return ext4_punch_hole(inode, offset, len);
4947
4948 ret = ext4_convert_inline_data(inode);
4949 if (ret)
4950 return ret;
4951
4952 if (mode & FALLOC_FL_COLLAPSE_RANGE)
4953 return ext4_collapse_range(inode, offset, len);
4954
4955 if (mode & FALLOC_FL_INSERT_RANGE)
4956 return ext4_insert_range(inode, offset, len);
4957
4958 if (mode & FALLOC_FL_ZERO_RANGE)
4959 return ext4_zero_range(file, offset, len, mode);
4960
4961 trace_ext4_fallocate_enter(inode, offset, len, mode);
4962 lblk = offset >> blkbits;
4963 /*
4964 * We can't just convert len to max_blocks because
4965 * If blocksize = 4096 offset = 3072 and len = 2048
4966 */
4967 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
4968 - lblk;
4969
4970 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4971 if (mode & FALLOC_FL_KEEP_SIZE)
4972 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4973
4974 inode_lock(inode);
4975
4976 /*
4977 * We only support preallocation for extent-based files only
4978 */
4979 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4980 ret = -EOPNOTSUPP;
4981 goto out;
4982 }
4983
4984 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4985 offset + len > i_size_read(inode)) {
4986 new_size = offset + len;
4987 ret = inode_newsize_ok(inode, new_size);
4988 if (ret)
4989 goto out;
4990 }
4991
4992 /* Wait all existing dio workers, newcomers will block on i_mutex */
4993 ext4_inode_block_unlocked_dio(inode);
4994 inode_dio_wait(inode);
4995
4996 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4997 flags, mode);
4998 ext4_inode_resume_unlocked_dio(inode);
4999 if (ret)
5000 goto out;
5001
5002 if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
5003 ret = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal,
5004 EXT4_I(inode)->i_sync_tid);
5005 }
5006out:
5007 inode_unlock(inode);
5008 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
5009 return ret;
5010}
5011
5012/*
5013 * This function convert a range of blocks to written extents
5014 * The caller of this function will pass the start offset and the size.
5015 * all unwritten extents within this range will be converted to
5016 * written extents.
5017 *
5018 * This function is called from the direct IO end io call back
5019 * function, to convert the fallocated extents after IO is completed.
5020 * Returns 0 on success.
5021 */
5022int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
5023 loff_t offset, ssize_t len)
5024{
5025 unsigned int max_blocks;
5026 int ret = 0;
5027 int ret2 = 0;
5028 struct ext4_map_blocks map;
5029 unsigned int credits, blkbits = inode->i_blkbits;
5030
5031 map.m_lblk = offset >> blkbits;
5032 /*
5033 * We can't just convert len to max_blocks because
5034 * If blocksize = 4096 offset = 3072 and len = 2048
5035 */
5036 max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
5037 map.m_lblk);
5038 /*
5039 * This is somewhat ugly but the idea is clear: When transaction is
5040 * reserved, everything goes into it. Otherwise we rather start several
5041 * smaller transactions for conversion of each extent separately.
5042 */
5043 if (handle) {
5044 handle = ext4_journal_start_reserved(handle,
5045 EXT4_HT_EXT_CONVERT);
5046 if (IS_ERR(handle))
5047 return PTR_ERR(handle);
5048 credits = 0;
5049 } else {
5050 /*
5051 * credits to insert 1 extent into extent tree
5052 */
5053 credits = ext4_chunk_trans_blocks(inode, max_blocks);
5054 }
5055 while (ret >= 0 && ret < max_blocks) {
5056 map.m_lblk += ret;
5057 map.m_len = (max_blocks -= ret);
5058 if (credits) {
5059 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
5060 credits);
5061 if (IS_ERR(handle)) {
5062 ret = PTR_ERR(handle);
5063 break;
5064 }
5065 }
5066 ret = ext4_map_blocks(handle, inode, &map,
5067 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
5068 if (ret <= 0)
5069 ext4_warning(inode->i_sb,
5070 "inode #%lu: block %u: len %u: "
5071 "ext4_ext_map_blocks returned %d",
5072 inode->i_ino, map.m_lblk,
5073 map.m_len, ret);
5074 ext4_mark_inode_dirty(handle, inode);
5075 if (credits)
5076 ret2 = ext4_journal_stop(handle);
5077 if (ret <= 0 || ret2)
5078 break;
5079 }
5080 if (!credits)
5081 ret2 = ext4_journal_stop(handle);
5082 return ret > 0 ? ret2 : ret;
5083}
5084
5085/*
5086 * If newes is not existing extent (newes->ec_pblk equals zero) find
5087 * delayed extent at start of newes and update newes accordingly and
5088 * return start of the next delayed extent.
5089 *
5090 * If newes is existing extent (newes->ec_pblk is not equal zero)
5091 * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
5092 * extent found. Leave newes unmodified.
5093 */
5094static int ext4_find_delayed_extent(struct inode *inode,
5095 struct extent_status *newes)
5096{
5097 struct extent_status es;
5098 ext4_lblk_t block, next_del;
5099
5100 if (newes->es_pblk == 0) {
5101 ext4_es_find_delayed_extent_range(inode, newes->es_lblk,
5102 newes->es_lblk + newes->es_len - 1, &es);
5103
5104 /*
5105 * No extent in extent-tree contains block @newes->es_pblk,
5106 * then the block may stay in 1)a hole or 2)delayed-extent.
5107 */
5108 if (es.es_len == 0)
5109 /* A hole found. */
5110 return 0;
5111
5112 if (es.es_lblk > newes->es_lblk) {
5113 /* A hole found. */
5114 newes->es_len = min(es.es_lblk - newes->es_lblk,
5115 newes->es_len);
5116 return 0;
5117 }
5118
5119 newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
5120 }
5121
5122 block = newes->es_lblk + newes->es_len;
5123 ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es);
5124 if (es.es_len == 0)
5125 next_del = EXT_MAX_BLOCKS;
5126 else
5127 next_del = es.es_lblk;
5128
5129 return next_del;
5130}
5131/* fiemap flags we can handle specified here */
5132#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
5133
5134static int ext4_xattr_fiemap(struct inode *inode,
5135 struct fiemap_extent_info *fieinfo)
5136{
5137 __u64 physical = 0;
5138 __u64 length;
5139 __u32 flags = FIEMAP_EXTENT_LAST;
5140 int blockbits = inode->i_sb->s_blocksize_bits;
5141 int error = 0;
5142
5143 /* in-inode? */
5144 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
5145 struct ext4_iloc iloc;
5146 int offset; /* offset of xattr in inode */
5147
5148 error = ext4_get_inode_loc(inode, &iloc);
5149 if (error)
5150 return error;
5151 physical = (__u64)iloc.bh->b_blocknr << blockbits;
5152 offset = EXT4_GOOD_OLD_INODE_SIZE +
5153 EXT4_I(inode)->i_extra_isize;
5154 physical += offset;
5155 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
5156 flags |= FIEMAP_EXTENT_DATA_INLINE;
5157 brelse(iloc.bh);
5158 } else { /* external block */
5159 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
5160 length = inode->i_sb->s_blocksize;
5161 }
5162
5163 if (physical)
5164 error = fiemap_fill_next_extent(fieinfo, 0, physical,
5165 length, flags);
5166 return (error < 0 ? error : 0);
5167}
5168
5169int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
5170 __u64 start, __u64 len)
5171{
5172 ext4_lblk_t start_blk;
5173 int error = 0;
5174
5175 if (ext4_has_inline_data(inode)) {
5176 int has_inline = 1;
5177
5178 error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
5179 start, len);
5180
5181 if (has_inline)
5182 return error;
5183 }
5184
5185 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
5186 error = ext4_ext_precache(inode);
5187 if (error)
5188 return error;
5189 }
5190
5191 /* fallback to generic here if not in extents fmt */
5192 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
5193 return generic_block_fiemap(inode, fieinfo, start, len,
5194 ext4_get_block);
5195
5196 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
5197 return -EBADR;
5198
5199 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
5200 error = ext4_xattr_fiemap(inode, fieinfo);
5201 } else {
5202 ext4_lblk_t len_blks;
5203 __u64 last_blk;
5204
5205 start_blk = start >> inode->i_sb->s_blocksize_bits;
5206 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
5207 if (last_blk >= EXT_MAX_BLOCKS)
5208 last_blk = EXT_MAX_BLOCKS-1;
5209 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
5210
5211 /*
5212 * Walk the extent tree gathering extent information
5213 * and pushing extents back to the user.
5214 */
5215 error = ext4_fill_fiemap_extents(inode, start_blk,
5216 len_blks, fieinfo);
5217 }
5218 return error;
5219}
5220
5221/*
5222 * ext4_access_path:
5223 * Function to access the path buffer for marking it dirty.
5224 * It also checks if there are sufficient credits left in the journal handle
5225 * to update path.
5226 */
5227static int
5228ext4_access_path(handle_t *handle, struct inode *inode,
5229 struct ext4_ext_path *path)
5230{
5231 int credits, err;
5232
5233 if (!ext4_handle_valid(handle))
5234 return 0;
5235
5236 /*
5237 * Check if need to extend journal credits
5238 * 3 for leaf, sb, and inode plus 2 (bmap and group
5239 * descriptor) for each block group; assume two block
5240 * groups
5241 */
5242 if (handle->h_buffer_credits < 7) {
5243 credits = ext4_writepage_trans_blocks(inode);
5244 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
5245 /* EAGAIN is success */
5246 if (err && err != -EAGAIN)
5247 return err;
5248 }
5249
5250 err = ext4_ext_get_access(handle, inode, path);
5251 return err;
5252}
5253
5254/*
5255 * ext4_ext_shift_path_extents:
5256 * Shift the extents of a path structure lying between path[depth].p_ext
5257 * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
5258 * if it is right shift or left shift operation.
5259 */
5260static int
5261ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
5262 struct inode *inode, handle_t *handle,
5263 enum SHIFT_DIRECTION SHIFT)
5264{
5265 int depth, err = 0;
5266 struct ext4_extent *ex_start, *ex_last;
5267 bool update = 0;
5268 depth = path->p_depth;
5269
5270 while (depth >= 0) {
5271 if (depth == path->p_depth) {
5272 ex_start = path[depth].p_ext;
5273 if (!ex_start)
5274 return -EFSCORRUPTED;
5275
5276 ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
5277
5278 err = ext4_access_path(handle, inode, path + depth);
5279 if (err)
5280 goto out;
5281
5282 if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr))
5283 update = 1;
5284
5285 while (ex_start <= ex_last) {
5286 if (SHIFT == SHIFT_LEFT) {
5287 le32_add_cpu(&ex_start->ee_block,
5288 -shift);
5289 /* Try to merge to the left. */
5290 if ((ex_start >
5291 EXT_FIRST_EXTENT(path[depth].p_hdr))
5292 &&
5293 ext4_ext_try_to_merge_right(inode,
5294 path, ex_start - 1))
5295 ex_last--;
5296 else
5297 ex_start++;
5298 } else {
5299 le32_add_cpu(&ex_last->ee_block, shift);
5300 ext4_ext_try_to_merge_right(inode, path,
5301 ex_last);
5302 ex_last--;
5303 }
5304 }
5305 err = ext4_ext_dirty(handle, inode, path + depth);
5306 if (err)
5307 goto out;
5308
5309 if (--depth < 0 || !update)
5310 break;
5311 }
5312
5313 /* Update index too */
5314 err = ext4_access_path(handle, inode, path + depth);
5315 if (err)
5316 goto out;
5317
5318 if (SHIFT == SHIFT_LEFT)
5319 le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
5320 else
5321 le32_add_cpu(&path[depth].p_idx->ei_block, shift);
5322 err = ext4_ext_dirty(handle, inode, path + depth);
5323 if (err)
5324 goto out;
5325
5326 /* we are done if current index is not a starting index */
5327 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
5328 break;
5329
5330 depth--;
5331 }
5332
5333out:
5334 return err;
5335}
5336
5337/*
5338 * ext4_ext_shift_extents:
5339 * All the extents which lies in the range from @start to the last allocated
5340 * block for the @inode are shifted either towards left or right (depending
5341 * upon @SHIFT) by @shift blocks.
5342 * On success, 0 is returned, error otherwise.
5343 */
5344static int
5345ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
5346 ext4_lblk_t start, ext4_lblk_t shift,
5347 enum SHIFT_DIRECTION SHIFT)
5348{
5349 struct ext4_ext_path *path;
5350 int ret = 0, depth;
5351 struct ext4_extent *extent;
5352 ext4_lblk_t stop, *iterator, ex_start, ex_end;
5353
5354 /* Let path point to the last extent */
5355 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 0);
5356 if (IS_ERR(path))
5357 return PTR_ERR(path);
5358
5359 depth = path->p_depth;
5360 extent = path[depth].p_ext;
5361 if (!extent)
5362 goto out;
5363
5364 stop = le32_to_cpu(extent->ee_block) +
5365 ext4_ext_get_actual_len(extent);
5366
5367 /*
5368 * In case of left shift, Don't start shifting extents until we make
5369 * sure the hole is big enough to accommodate the shift.
5370 */
5371 if (SHIFT == SHIFT_LEFT) {
5372 path = ext4_find_extent(inode, start - 1, &path, 0);
5373 if (IS_ERR(path))
5374 return PTR_ERR(path);
5375 depth = path->p_depth;
5376 extent = path[depth].p_ext;
5377 if (extent) {
5378 ex_start = le32_to_cpu(extent->ee_block);
5379 ex_end = le32_to_cpu(extent->ee_block) +
5380 ext4_ext_get_actual_len(extent);
5381 } else {
5382 ex_start = 0;
5383 ex_end = 0;
5384 }
5385
5386 if ((start == ex_start && shift > ex_start) ||
5387 (shift > start - ex_end)) {
5388 ext4_ext_drop_refs(path);
5389 kfree(path);
5390 return -EINVAL;
5391 }
5392 }
5393
5394 /*
5395 * In case of left shift, iterator points to start and it is increased
5396 * till we reach stop. In case of right shift, iterator points to stop
5397 * and it is decreased till we reach start.
5398 */
5399 if (SHIFT == SHIFT_LEFT)
5400 iterator = &start;
5401 else
5402 iterator = &stop;
5403
5404 /* Its safe to start updating extents */
5405 while (start < stop) {
5406 path = ext4_find_extent(inode, *iterator, &path, 0);
5407 if (IS_ERR(path))
5408 return PTR_ERR(path);
5409 depth = path->p_depth;
5410 extent = path[depth].p_ext;
5411 if (!extent) {
5412 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
5413 (unsigned long) *iterator);
5414 return -EFSCORRUPTED;
5415 }
5416 if (SHIFT == SHIFT_LEFT && *iterator >
5417 le32_to_cpu(extent->ee_block)) {
5418 /* Hole, move to the next extent */
5419 if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
5420 path[depth].p_ext++;
5421 } else {
5422 *iterator = ext4_ext_next_allocated_block(path);
5423 continue;
5424 }
5425 }
5426
5427 if (SHIFT == SHIFT_LEFT) {
5428 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5429 *iterator = le32_to_cpu(extent->ee_block) +
5430 ext4_ext_get_actual_len(extent);
5431 } else {
5432 extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
5433 *iterator = le32_to_cpu(extent->ee_block) > 0 ?
5434 le32_to_cpu(extent->ee_block) - 1 : 0;
5435 /* Update path extent in case we need to stop */
5436 while (le32_to_cpu(extent->ee_block) < start)
5437 extent++;
5438 path[depth].p_ext = extent;
5439 }
5440 ret = ext4_ext_shift_path_extents(path, shift, inode,
5441 handle, SHIFT);
5442 if (ret)
5443 break;
5444 }
5445out:
5446 ext4_ext_drop_refs(path);
5447 kfree(path);
5448 return ret;
5449}
5450
5451/*
5452 * ext4_collapse_range:
5453 * This implements the fallocate's collapse range functionality for ext4
5454 * Returns: 0 and non-zero on error.
5455 */
5456int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
5457{
5458 struct super_block *sb = inode->i_sb;
5459 ext4_lblk_t punch_start, punch_stop;
5460 handle_t *handle;
5461 unsigned int credits;
5462 loff_t new_size, ioffset;
5463 int ret;
5464
5465 /*
5466 * We need to test this early because xfstests assumes that a
5467 * collapse range of (0, 1) will return EOPNOTSUPP if the file
5468 * system does not support collapse range.
5469 */
5470 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5471 return -EOPNOTSUPP;
5472
5473 /* Collapse range works only on fs block size aligned offsets. */
5474 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
5475 len & (EXT4_CLUSTER_SIZE(sb) - 1))
5476 return -EINVAL;
5477
5478 if (!S_ISREG(inode->i_mode))
5479 return -EINVAL;
5480
5481 trace_ext4_collapse_range(inode, offset, len);
5482
5483 punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5484 punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb);
5485
5486 /* Call ext4_force_commit to flush all data in case of data=journal. */
5487 if (ext4_should_journal_data(inode)) {
5488 ret = ext4_force_commit(inode->i_sb);
5489 if (ret)
5490 return ret;
5491 }
5492
5493 inode_lock(inode);
5494 /*
5495 * There is no need to overlap collapse range with EOF, in which case
5496 * it is effectively a truncate operation
5497 */
5498 if (offset + len >= i_size_read(inode)) {
5499 ret = -EINVAL;
5500 goto out_mutex;
5501 }
5502
5503 /* Currently just for extent based files */
5504 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5505 ret = -EOPNOTSUPP;
5506 goto out_mutex;
5507 }
5508
5509 /* Wait for existing dio to complete */
5510 ext4_inode_block_unlocked_dio(inode);
5511 inode_dio_wait(inode);
5512
5513 /*
5514 * Prevent page faults from reinstantiating pages we have released from
5515 * page cache.
5516 */
5517 down_write(&EXT4_I(inode)->i_mmap_sem);
5518 /*
5519 * Need to round down offset to be aligned with page size boundary
5520 * for page size > block size.
5521 */
5522 ioffset = round_down(offset, PAGE_SIZE);
5523 /*
5524 * Write tail of the last page before removed range since it will get
5525 * removed from the page cache below.
5526 */
5527 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, offset);
5528 if (ret)
5529 goto out_mmap;
5530 /*
5531 * Write data that will be shifted to preserve them when discarding
5532 * page cache below. We are also protected from pages becoming dirty
5533 * by i_mmap_sem.
5534 */
5535 ret = filemap_write_and_wait_range(inode->i_mapping, offset + len,
5536 LLONG_MAX);
5537 if (ret)
5538 goto out_mmap;
5539 truncate_pagecache(inode, ioffset);
5540
5541 credits = ext4_writepage_trans_blocks(inode);
5542 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5543 if (IS_ERR(handle)) {
5544 ret = PTR_ERR(handle);
5545 goto out_mmap;
5546 }
5547
5548 down_write(&EXT4_I(inode)->i_data_sem);
5549 ext4_discard_preallocations(inode);
5550
5551 ret = ext4_es_remove_extent(inode, punch_start,
5552 EXT_MAX_BLOCKS - punch_start);
5553 if (ret) {
5554 up_write(&EXT4_I(inode)->i_data_sem);
5555 goto out_stop;
5556 }
5557
5558 ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
5559 if (ret) {
5560 up_write(&EXT4_I(inode)->i_data_sem);
5561 goto out_stop;
5562 }
5563 ext4_discard_preallocations(inode);
5564
5565 ret = ext4_ext_shift_extents(inode, handle, punch_stop,
5566 punch_stop - punch_start, SHIFT_LEFT);
5567 if (ret) {
5568 up_write(&EXT4_I(inode)->i_data_sem);
5569 goto out_stop;
5570 }
5571
5572 new_size = i_size_read(inode) - len;
5573 i_size_write(inode, new_size);
5574 EXT4_I(inode)->i_disksize = new_size;
5575
5576 up_write(&EXT4_I(inode)->i_data_sem);
5577 if (IS_SYNC(inode))
5578 ext4_handle_sync(handle);
5579 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
5580 ext4_mark_inode_dirty(handle, inode);
5581
5582out_stop:
5583 ext4_journal_stop(handle);
5584out_mmap:
5585 up_write(&EXT4_I(inode)->i_mmap_sem);
5586 ext4_inode_resume_unlocked_dio(inode);
5587out_mutex:
5588 inode_unlock(inode);
5589 return ret;
5590}
5591
5592/*
5593 * ext4_insert_range:
5594 * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
5595 * The data blocks starting from @offset to the EOF are shifted by @len
5596 * towards right to create a hole in the @inode. Inode size is increased
5597 * by len bytes.
5598 * Returns 0 on success, error otherwise.
5599 */
5600int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
5601{
5602 struct super_block *sb = inode->i_sb;
5603 handle_t *handle;
5604 struct ext4_ext_path *path;
5605 struct ext4_extent *extent;
5606 ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
5607 unsigned int credits, ee_len;
5608 int ret = 0, depth, split_flag = 0;
5609 loff_t ioffset;
5610
5611 /*
5612 * We need to test this early because xfstests assumes that an
5613 * insert range of (0, 1) will return EOPNOTSUPP if the file
5614 * system does not support insert range.
5615 */
5616 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5617 return -EOPNOTSUPP;
5618
5619 /* Insert range works only on fs block size aligned offsets. */
5620 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
5621 len & (EXT4_CLUSTER_SIZE(sb) - 1))
5622 return -EINVAL;
5623
5624 if (!S_ISREG(inode->i_mode))
5625 return -EOPNOTSUPP;
5626
5627 trace_ext4_insert_range(inode, offset, len);
5628
5629 offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5630 len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
5631
5632 /* Call ext4_force_commit to flush all data in case of data=journal */
5633 if (ext4_should_journal_data(inode)) {
5634 ret = ext4_force_commit(inode->i_sb);
5635 if (ret)
5636 return ret;
5637 }
5638
5639 inode_lock(inode);
5640 /* Currently just for extent based files */
5641 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5642 ret = -EOPNOTSUPP;
5643 goto out_mutex;
5644 }
5645
5646 /* Check for wrap through zero */
5647 if (inode->i_size + len > inode->i_sb->s_maxbytes) {
5648 ret = -EFBIG;
5649 goto out_mutex;
5650 }
5651
5652 /* Offset should be less than i_size */
5653 if (offset >= i_size_read(inode)) {
5654 ret = -EINVAL;
5655 goto out_mutex;
5656 }
5657
5658 /* Wait for existing dio to complete */
5659 ext4_inode_block_unlocked_dio(inode);
5660 inode_dio_wait(inode);
5661
5662 /*
5663 * Prevent page faults from reinstantiating pages we have released from
5664 * page cache.
5665 */
5666 down_write(&EXT4_I(inode)->i_mmap_sem);
5667 /*
5668 * Need to round down to align start offset to page size boundary
5669 * for page size > block size.
5670 */
5671 ioffset = round_down(offset, PAGE_SIZE);
5672 /* Write out all dirty pages */
5673 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5674 LLONG_MAX);
5675 if (ret)
5676 goto out_mmap;
5677 truncate_pagecache(inode, ioffset);
5678
5679 credits = ext4_writepage_trans_blocks(inode);
5680 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5681 if (IS_ERR(handle)) {
5682 ret = PTR_ERR(handle);
5683 goto out_mmap;
5684 }
5685
5686 /* Expand file to avoid data loss if there is error while shifting */
5687 inode->i_size += len;
5688 EXT4_I(inode)->i_disksize += len;
5689 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
5690 ret = ext4_mark_inode_dirty(handle, inode);
5691 if (ret)
5692 goto out_stop;
5693
5694 down_write(&EXT4_I(inode)->i_data_sem);
5695 ext4_discard_preallocations(inode);
5696
5697 path = ext4_find_extent(inode, offset_lblk, NULL, 0);
5698 if (IS_ERR(path)) {
5699 up_write(&EXT4_I(inode)->i_data_sem);
5700 goto out_stop;
5701 }
5702
5703 depth = ext_depth(inode);
5704 extent = path[depth].p_ext;
5705 if (extent) {
5706 ee_start_lblk = le32_to_cpu(extent->ee_block);
5707 ee_len = ext4_ext_get_actual_len(extent);
5708
5709 /*
5710 * If offset_lblk is not the starting block of extent, split
5711 * the extent @offset_lblk
5712 */
5713 if ((offset_lblk > ee_start_lblk) &&
5714 (offset_lblk < (ee_start_lblk + ee_len))) {
5715 if (ext4_ext_is_unwritten(extent))
5716 split_flag = EXT4_EXT_MARK_UNWRIT1 |
5717 EXT4_EXT_MARK_UNWRIT2;
5718 ret = ext4_split_extent_at(handle, inode, &path,
5719 offset_lblk, split_flag,
5720 EXT4_EX_NOCACHE |
5721 EXT4_GET_BLOCKS_PRE_IO |
5722 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5723 }
5724
5725 ext4_ext_drop_refs(path);
5726 kfree(path);
5727 if (ret < 0) {
5728 up_write(&EXT4_I(inode)->i_data_sem);
5729 goto out_stop;
5730 }
5731 }
5732
5733 ret = ext4_es_remove_extent(inode, offset_lblk,
5734 EXT_MAX_BLOCKS - offset_lblk);
5735 if (ret) {
5736 up_write(&EXT4_I(inode)->i_data_sem);
5737 goto out_stop;
5738 }
5739
5740 /*
5741 * if offset_lblk lies in a hole which is at start of file, use
5742 * ee_start_lblk to shift extents
5743 */
5744 ret = ext4_ext_shift_extents(inode, handle,
5745 ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk,
5746 len_lblk, SHIFT_RIGHT);
5747
5748 up_write(&EXT4_I(inode)->i_data_sem);
5749 if (IS_SYNC(inode))
5750 ext4_handle_sync(handle);
5751
5752out_stop:
5753 ext4_journal_stop(handle);
5754out_mmap:
5755 up_write(&EXT4_I(inode)->i_mmap_sem);
5756 ext4_inode_resume_unlocked_dio(inode);
5757out_mutex:
5758 inode_unlock(inode);
5759 return ret;
5760}
5761
5762/**
5763 * ext4_swap_extents - Swap extents between two inodes
5764 *
5765 * @inode1: First inode
5766 * @inode2: Second inode
5767 * @lblk1: Start block for first inode
5768 * @lblk2: Start block for second inode
5769 * @count: Number of blocks to swap
5770 * @mark_unwritten: Mark second inode's extents as unwritten after swap
5771 * @erp: Pointer to save error value
5772 *
5773 * This helper routine does exactly what is promise "swap extents". All other
5774 * stuff such as page-cache locking consistency, bh mapping consistency or
5775 * extent's data copying must be performed by caller.
5776 * Locking:
5777 * i_mutex is held for both inodes
5778 * i_data_sem is locked for write for both inodes
5779 * Assumptions:
5780 * All pages from requested range are locked for both inodes
5781 */
5782int
5783ext4_swap_extents(handle_t *handle, struct inode *inode1,
5784 struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
5785 ext4_lblk_t count, int unwritten, int *erp)
5786{
5787 struct ext4_ext_path *path1 = NULL;
5788 struct ext4_ext_path *path2 = NULL;
5789 int replaced_count = 0;
5790
5791 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
5792 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
5793 BUG_ON(!inode_is_locked(inode1));
5794 BUG_ON(!inode_is_locked(inode2));
5795
5796 *erp = ext4_es_remove_extent(inode1, lblk1, count);
5797 if (unlikely(*erp))
5798 return 0;
5799 *erp = ext4_es_remove_extent(inode2, lblk2, count);
5800 if (unlikely(*erp))
5801 return 0;
5802
5803 while (count) {
5804 struct ext4_extent *ex1, *ex2, tmp_ex;
5805 ext4_lblk_t e1_blk, e2_blk;
5806 int e1_len, e2_len, len;
5807 int split = 0;
5808
5809 path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE);
5810 if (IS_ERR(path1)) {
5811 *erp = PTR_ERR(path1);
5812 path1 = NULL;
5813 finish:
5814 count = 0;
5815 goto repeat;
5816 }
5817 path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE);
5818 if (IS_ERR(path2)) {
5819 *erp = PTR_ERR(path2);
5820 path2 = NULL;
5821 goto finish;
5822 }
5823 ex1 = path1[path1->p_depth].p_ext;
5824 ex2 = path2[path2->p_depth].p_ext;
5825 /* Do we have somthing to swap ? */
5826 if (unlikely(!ex2 || !ex1))
5827 goto finish;
5828
5829 e1_blk = le32_to_cpu(ex1->ee_block);
5830 e2_blk = le32_to_cpu(ex2->ee_block);
5831 e1_len = ext4_ext_get_actual_len(ex1);
5832 e2_len = ext4_ext_get_actual_len(ex2);
5833
5834 /* Hole handling */
5835 if (!in_range(lblk1, e1_blk, e1_len) ||
5836 !in_range(lblk2, e2_blk, e2_len)) {
5837 ext4_lblk_t next1, next2;
5838
5839 /* if hole after extent, then go to next extent */
5840 next1 = ext4_ext_next_allocated_block(path1);
5841 next2 = ext4_ext_next_allocated_block(path2);
5842 /* If hole before extent, then shift to that extent */
5843 if (e1_blk > lblk1)
5844 next1 = e1_blk;
5845 if (e2_blk > lblk2)
5846 next2 = e1_blk;
5847 /* Do we have something to swap */
5848 if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
5849 goto finish;
5850 /* Move to the rightest boundary */
5851 len = next1 - lblk1;
5852 if (len < next2 - lblk2)
5853 len = next2 - lblk2;
5854 if (len > count)
5855 len = count;
5856 lblk1 += len;
5857 lblk2 += len;
5858 count -= len;
5859 goto repeat;
5860 }
5861
5862 /* Prepare left boundary */
5863 if (e1_blk < lblk1) {
5864 split = 1;
5865 *erp = ext4_force_split_extent_at(handle, inode1,
5866 &path1, lblk1, 0);
5867 if (unlikely(*erp))
5868 goto finish;
5869 }
5870 if (e2_blk < lblk2) {
5871 split = 1;
5872 *erp = ext4_force_split_extent_at(handle, inode2,
5873 &path2, lblk2, 0);
5874 if (unlikely(*erp))
5875 goto finish;
5876 }
5877 /* ext4_split_extent_at() may result in leaf extent split,
5878 * path must to be revalidated. */
5879 if (split)
5880 goto repeat;
5881
5882 /* Prepare right boundary */
5883 len = count;
5884 if (len > e1_blk + e1_len - lblk1)
5885 len = e1_blk + e1_len - lblk1;
5886 if (len > e2_blk + e2_len - lblk2)
5887 len = e2_blk + e2_len - lblk2;
5888
5889 if (len != e1_len) {
5890 split = 1;
5891 *erp = ext4_force_split_extent_at(handle, inode1,
5892 &path1, lblk1 + len, 0);
5893 if (unlikely(*erp))
5894 goto finish;
5895 }
5896 if (len != e2_len) {
5897 split = 1;
5898 *erp = ext4_force_split_extent_at(handle, inode2,
5899 &path2, lblk2 + len, 0);
5900 if (*erp)
5901 goto finish;
5902 }
5903 /* ext4_split_extent_at() may result in leaf extent split,
5904 * path must to be revalidated. */
5905 if (split)
5906 goto repeat;
5907
5908 BUG_ON(e2_len != e1_len);
5909 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
5910 if (unlikely(*erp))
5911 goto finish;
5912 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
5913 if (unlikely(*erp))
5914 goto finish;
5915
5916 /* Both extents are fully inside boundaries. Swap it now */
5917 tmp_ex = *ex1;
5918 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
5919 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
5920 ex1->ee_len = cpu_to_le16(e2_len);
5921 ex2->ee_len = cpu_to_le16(e1_len);
5922 if (unwritten)
5923 ext4_ext_mark_unwritten(ex2);
5924 if (ext4_ext_is_unwritten(&tmp_ex))
5925 ext4_ext_mark_unwritten(ex1);
5926
5927 ext4_ext_try_to_merge(handle, inode2, path2, ex2);
5928 ext4_ext_try_to_merge(handle, inode1, path1, ex1);
5929 *erp = ext4_ext_dirty(handle, inode2, path2 +
5930 path2->p_depth);
5931 if (unlikely(*erp))
5932 goto finish;
5933 *erp = ext4_ext_dirty(handle, inode1, path1 +
5934 path1->p_depth);
5935 /*
5936 * Looks scarry ah..? second inode already points to new blocks,
5937 * and it was successfully dirtied. But luckily error may happen
5938 * only due to journal error, so full transaction will be
5939 * aborted anyway.
5940 */
5941 if (unlikely(*erp))
5942 goto finish;
5943 lblk1 += len;
5944 lblk2 += len;
5945 replaced_count += len;
5946 count -= len;
5947
5948 repeat:
5949 ext4_ext_drop_refs(path1);
5950 kfree(path1);
5951 ext4_ext_drop_refs(path2);
5952 kfree(path2);
5953 path1 = path2 = NULL;
5954 }
5955 return replaced_count;
5956}
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/backing-dev.h>
31#include "ext4_jbd2.h"
32#include "ext4_extents.h"
33#include "xattr.h"
34
35#include <trace/events/ext4.h>
36
37/*
38 * used by extent splitting.
39 */
40#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
41 due to ENOSPC */
42#define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */
43#define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */
44
45#define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
46#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
47
48static __le32 ext4_extent_block_csum(struct inode *inode,
49 struct ext4_extent_header *eh)
50{
51 struct ext4_inode_info *ei = EXT4_I(inode);
52 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
53 __u32 csum;
54
55 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
56 EXT4_EXTENT_TAIL_OFFSET(eh));
57 return cpu_to_le32(csum);
58}
59
60static int ext4_extent_block_csum_verify(struct inode *inode,
61 struct ext4_extent_header *eh)
62{
63 struct ext4_extent_tail *et;
64
65 if (!ext4_has_metadata_csum(inode->i_sb))
66 return 1;
67
68 et = find_ext4_extent_tail(eh);
69 if (et->et_checksum != ext4_extent_block_csum(inode, eh))
70 return 0;
71 return 1;
72}
73
74static void ext4_extent_block_csum_set(struct inode *inode,
75 struct ext4_extent_header *eh)
76{
77 struct ext4_extent_tail *et;
78
79 if (!ext4_has_metadata_csum(inode->i_sb))
80 return;
81
82 et = find_ext4_extent_tail(eh);
83 et->et_checksum = ext4_extent_block_csum(inode, eh);
84}
85
86static int ext4_split_extent(handle_t *handle,
87 struct inode *inode,
88 struct ext4_ext_path **ppath,
89 struct ext4_map_blocks *map,
90 int split_flag,
91 int flags);
92
93static int ext4_split_extent_at(handle_t *handle,
94 struct inode *inode,
95 struct ext4_ext_path **ppath,
96 ext4_lblk_t split,
97 int split_flag,
98 int flags);
99
100static int ext4_find_delayed_extent(struct inode *inode,
101 struct extent_status *newes);
102
103static int ext4_ext_truncate_extend_restart(handle_t *handle,
104 struct inode *inode,
105 int needed)
106{
107 int err;
108
109 if (!ext4_handle_valid(handle))
110 return 0;
111 if (handle->h_buffer_credits >= needed)
112 return 0;
113 /*
114 * If we need to extend the journal get a few extra blocks
115 * while we're at it for efficiency's sake.
116 */
117 needed += 3;
118 err = ext4_journal_extend(handle, needed - handle->h_buffer_credits);
119 if (err <= 0)
120 return err;
121 err = ext4_truncate_restart_trans(handle, inode, needed);
122 if (err == 0)
123 err = -EAGAIN;
124
125 return err;
126}
127
128/*
129 * could return:
130 * - EROFS
131 * - ENOMEM
132 */
133static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
134 struct ext4_ext_path *path)
135{
136 if (path->p_bh) {
137 /* path points to block */
138 BUFFER_TRACE(path->p_bh, "get_write_access");
139 return ext4_journal_get_write_access(handle, path->p_bh);
140 }
141 /* path points to leaf/index in inode body */
142 /* we use in-core data, no need to protect them */
143 return 0;
144}
145
146/*
147 * could return:
148 * - EROFS
149 * - ENOMEM
150 * - EIO
151 */
152int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle,
153 struct inode *inode, struct ext4_ext_path *path)
154{
155 int err;
156
157 WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
158 if (path->p_bh) {
159 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
160 /* path points to block */
161 err = __ext4_handle_dirty_metadata(where, line, handle,
162 inode, path->p_bh);
163 } else {
164 /* path points to leaf/index in inode body */
165 err = ext4_mark_inode_dirty(handle, inode);
166 }
167 return err;
168}
169
170static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
171 struct ext4_ext_path *path,
172 ext4_lblk_t block)
173{
174 if (path) {
175 int depth = path->p_depth;
176 struct ext4_extent *ex;
177
178 /*
179 * Try to predict block placement assuming that we are
180 * filling in a file which will eventually be
181 * non-sparse --- i.e., in the case of libbfd writing
182 * an ELF object sections out-of-order but in a way
183 * the eventually results in a contiguous object or
184 * executable file, or some database extending a table
185 * space file. However, this is actually somewhat
186 * non-ideal if we are writing a sparse file such as
187 * qemu or KVM writing a raw image file that is going
188 * to stay fairly sparse, since it will end up
189 * fragmenting the file system's free space. Maybe we
190 * should have some hueristics or some way to allow
191 * userspace to pass a hint to file system,
192 * especially if the latter case turns out to be
193 * common.
194 */
195 ex = path[depth].p_ext;
196 if (ex) {
197 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
198 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
199
200 if (block > ext_block)
201 return ext_pblk + (block - ext_block);
202 else
203 return ext_pblk - (ext_block - block);
204 }
205
206 /* it looks like index is empty;
207 * try to find starting block from index itself */
208 if (path[depth].p_bh)
209 return path[depth].p_bh->b_blocknr;
210 }
211
212 /* OK. use inode's group */
213 return ext4_inode_to_goal_block(inode);
214}
215
216/*
217 * Allocation for a meta data block
218 */
219static ext4_fsblk_t
220ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
221 struct ext4_ext_path *path,
222 struct ext4_extent *ex, int *err, unsigned int flags)
223{
224 ext4_fsblk_t goal, newblock;
225
226 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
227 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
228 NULL, err);
229 return newblock;
230}
231
232static inline int ext4_ext_space_block(struct inode *inode, int check)
233{
234 int size;
235
236 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
237 / sizeof(struct ext4_extent);
238#ifdef AGGRESSIVE_TEST
239 if (!check && size > 6)
240 size = 6;
241#endif
242 return size;
243}
244
245static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
246{
247 int size;
248
249 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
250 / sizeof(struct ext4_extent_idx);
251#ifdef AGGRESSIVE_TEST
252 if (!check && size > 5)
253 size = 5;
254#endif
255 return size;
256}
257
258static inline int ext4_ext_space_root(struct inode *inode, int check)
259{
260 int size;
261
262 size = sizeof(EXT4_I(inode)->i_data);
263 size -= sizeof(struct ext4_extent_header);
264 size /= sizeof(struct ext4_extent);
265#ifdef AGGRESSIVE_TEST
266 if (!check && size > 3)
267 size = 3;
268#endif
269 return size;
270}
271
272static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
273{
274 int size;
275
276 size = sizeof(EXT4_I(inode)->i_data);
277 size -= sizeof(struct ext4_extent_header);
278 size /= sizeof(struct ext4_extent_idx);
279#ifdef AGGRESSIVE_TEST
280 if (!check && size > 4)
281 size = 4;
282#endif
283 return size;
284}
285
286static inline int
287ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
288 struct ext4_ext_path **ppath, ext4_lblk_t lblk,
289 int nofail)
290{
291 struct ext4_ext_path *path = *ppath;
292 int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
293
294 return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ?
295 EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
296 EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO |
297 (nofail ? EXT4_GET_BLOCKS_METADATA_NOFAIL:0));
298}
299
300/*
301 * Calculate the number of metadata blocks needed
302 * to allocate @blocks
303 * Worse case is one block per extent
304 */
305int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
306{
307 struct ext4_inode_info *ei = EXT4_I(inode);
308 int idxs;
309
310 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
311 / sizeof(struct ext4_extent_idx));
312
313 /*
314 * If the new delayed allocation block is contiguous with the
315 * previous da block, it can share index blocks with the
316 * previous block, so we only need to allocate a new index
317 * block every idxs leaf blocks. At ldxs**2 blocks, we need
318 * an additional index block, and at ldxs**3 blocks, yet
319 * another index blocks.
320 */
321 if (ei->i_da_metadata_calc_len &&
322 ei->i_da_metadata_calc_last_lblock+1 == lblock) {
323 int num = 0;
324
325 if ((ei->i_da_metadata_calc_len % idxs) == 0)
326 num++;
327 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
328 num++;
329 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
330 num++;
331 ei->i_da_metadata_calc_len = 0;
332 } else
333 ei->i_da_metadata_calc_len++;
334 ei->i_da_metadata_calc_last_lblock++;
335 return num;
336 }
337
338 /*
339 * In the worst case we need a new set of index blocks at
340 * every level of the inode's extent tree.
341 */
342 ei->i_da_metadata_calc_len = 1;
343 ei->i_da_metadata_calc_last_lblock = lblock;
344 return ext_depth(inode) + 1;
345}
346
347static int
348ext4_ext_max_entries(struct inode *inode, int depth)
349{
350 int max;
351
352 if (depth == ext_depth(inode)) {
353 if (depth == 0)
354 max = ext4_ext_space_root(inode, 1);
355 else
356 max = ext4_ext_space_root_idx(inode, 1);
357 } else {
358 if (depth == 0)
359 max = ext4_ext_space_block(inode, 1);
360 else
361 max = ext4_ext_space_block_idx(inode, 1);
362 }
363
364 return max;
365}
366
367static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
368{
369 ext4_fsblk_t block = ext4_ext_pblock(ext);
370 int len = ext4_ext_get_actual_len(ext);
371 ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
372
373 /*
374 * We allow neither:
375 * - zero length
376 * - overflow/wrap-around
377 */
378 if (lblock + len <= lblock)
379 return 0;
380 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
381}
382
383static int ext4_valid_extent_idx(struct inode *inode,
384 struct ext4_extent_idx *ext_idx)
385{
386 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
387
388 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
389}
390
391static int ext4_valid_extent_entries(struct inode *inode,
392 struct ext4_extent_header *eh,
393 int depth)
394{
395 unsigned short entries;
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 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
405 ext4_fsblk_t pblock = 0;
406 ext4_lblk_t lblock = 0;
407 ext4_lblk_t prev = 0;
408 int len = 0;
409 while (entries) {
410 if (!ext4_valid_extent(inode, ext))
411 return 0;
412
413 /* Check for overlapping extents */
414 lblock = le32_to_cpu(ext->ee_block);
415 len = ext4_ext_get_actual_len(ext);
416 if ((lblock <= prev) && prev) {
417 pblock = ext4_ext_pblock(ext);
418 es->s_last_error_block = cpu_to_le64(pblock);
419 return 0;
420 }
421 ext++;
422 entries--;
423 prev = lblock + len - 1;
424 }
425 } else {
426 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
427 while (entries) {
428 if (!ext4_valid_extent_idx(inode, ext_idx))
429 return 0;
430 ext_idx++;
431 entries--;
432 }
433 }
434 return 1;
435}
436
437static int __ext4_ext_check(const char *function, unsigned int line,
438 struct inode *inode, struct ext4_extent_header *eh,
439 int depth, ext4_fsblk_t pblk)
440{
441 const char *error_msg;
442 int max = 0, err = -EFSCORRUPTED;
443
444 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
445 error_msg = "invalid magic";
446 goto corrupted;
447 }
448 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
449 error_msg = "unexpected eh_depth";
450 goto corrupted;
451 }
452 if (unlikely(eh->eh_max == 0)) {
453 error_msg = "invalid eh_max";
454 goto corrupted;
455 }
456 max = ext4_ext_max_entries(inode, depth);
457 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
458 error_msg = "too large eh_max";
459 goto corrupted;
460 }
461 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
462 error_msg = "invalid eh_entries";
463 goto corrupted;
464 }
465 if (!ext4_valid_extent_entries(inode, eh, depth)) {
466 error_msg = "invalid extent entries";
467 goto corrupted;
468 }
469 if (unlikely(depth > 32)) {
470 error_msg = "too large eh_depth";
471 goto corrupted;
472 }
473 /* Verify checksum on non-root extent tree nodes */
474 if (ext_depth(inode) != depth &&
475 !ext4_extent_block_csum_verify(inode, eh)) {
476 error_msg = "extent tree corrupted";
477 err = -EFSBADCRC;
478 goto corrupted;
479 }
480 return 0;
481
482corrupted:
483 ext4_error_inode(inode, function, line, 0,
484 "pblk %llu bad header/extent: %s - magic %x, "
485 "entries %u, max %u(%u), depth %u(%u)",
486 (unsigned long long) pblk, error_msg,
487 le16_to_cpu(eh->eh_magic),
488 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
489 max, le16_to_cpu(eh->eh_depth), depth);
490 return err;
491}
492
493#define ext4_ext_check(inode, eh, depth, pblk) \
494 __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk))
495
496int ext4_ext_check_inode(struct inode *inode)
497{
498 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
499}
500
501static struct buffer_head *
502__read_extent_tree_block(const char *function, unsigned int line,
503 struct inode *inode, ext4_fsblk_t pblk, int depth,
504 int flags)
505{
506 struct buffer_head *bh;
507 int err;
508
509 bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
510 if (unlikely(!bh))
511 return ERR_PTR(-ENOMEM);
512
513 if (!bh_uptodate_or_lock(bh)) {
514 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
515 err = bh_submit_read(bh);
516 if (err < 0)
517 goto errout;
518 }
519 if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
520 return bh;
521 err = __ext4_ext_check(function, line, inode,
522 ext_block_hdr(bh), depth, pblk);
523 if (err)
524 goto errout;
525 set_buffer_verified(bh);
526 /*
527 * If this is a leaf block, cache all of its entries
528 */
529 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
530 struct ext4_extent_header *eh = ext_block_hdr(bh);
531 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
532 ext4_lblk_t prev = 0;
533 int i;
534
535 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
536 unsigned int status = EXTENT_STATUS_WRITTEN;
537 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
538 int len = ext4_ext_get_actual_len(ex);
539
540 if (prev && (prev != lblk))
541 ext4_es_cache_extent(inode, prev,
542 lblk - prev, ~0,
543 EXTENT_STATUS_HOLE);
544
545 if (ext4_ext_is_unwritten(ex))
546 status = EXTENT_STATUS_UNWRITTEN;
547 ext4_es_cache_extent(inode, lblk, len,
548 ext4_ext_pblock(ex), status);
549 prev = lblk + len;
550 }
551 }
552 return bh;
553errout:
554 put_bh(bh);
555 return ERR_PTR(err);
556
557}
558
559#define read_extent_tree_block(inode, pblk, depth, flags) \
560 __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \
561 (depth), (flags))
562
563/*
564 * This function is called to cache a file's extent information in the
565 * extent status tree
566 */
567int ext4_ext_precache(struct inode *inode)
568{
569 struct ext4_inode_info *ei = EXT4_I(inode);
570 struct ext4_ext_path *path = NULL;
571 struct buffer_head *bh;
572 int i = 0, depth, ret = 0;
573
574 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
575 return 0; /* not an extent-mapped inode */
576
577 down_read(&ei->i_data_sem);
578 depth = ext_depth(inode);
579
580 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
581 GFP_NOFS);
582 if (path == NULL) {
583 up_read(&ei->i_data_sem);
584 return -ENOMEM;
585 }
586
587 /* Don't cache anything if there are no external extent blocks */
588 if (depth == 0)
589 goto out;
590 path[0].p_hdr = ext_inode_hdr(inode);
591 ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
592 if (ret)
593 goto out;
594 path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
595 while (i >= 0) {
596 /*
597 * If this is a leaf block or we've reached the end of
598 * the index block, go up
599 */
600 if ((i == depth) ||
601 path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
602 brelse(path[i].p_bh);
603 path[i].p_bh = NULL;
604 i--;
605 continue;
606 }
607 bh = read_extent_tree_block(inode,
608 ext4_idx_pblock(path[i].p_idx++),
609 depth - i - 1,
610 EXT4_EX_FORCE_CACHE);
611 if (IS_ERR(bh)) {
612 ret = PTR_ERR(bh);
613 break;
614 }
615 i++;
616 path[i].p_bh = bh;
617 path[i].p_hdr = ext_block_hdr(bh);
618 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
619 }
620 ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
621out:
622 up_read(&ei->i_data_sem);
623 ext4_ext_drop_refs(path);
624 kfree(path);
625 return ret;
626}
627
628#ifdef EXT_DEBUG
629static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
630{
631 int k, l = path->p_depth;
632
633 ext_debug("path:");
634 for (k = 0; k <= l; k++, path++) {
635 if (path->p_idx) {
636 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
637 ext4_idx_pblock(path->p_idx));
638 } else if (path->p_ext) {
639 ext_debug(" %d:[%d]%d:%llu ",
640 le32_to_cpu(path->p_ext->ee_block),
641 ext4_ext_is_unwritten(path->p_ext),
642 ext4_ext_get_actual_len(path->p_ext),
643 ext4_ext_pblock(path->p_ext));
644 } else
645 ext_debug(" []");
646 }
647 ext_debug("\n");
648}
649
650static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
651{
652 int depth = ext_depth(inode);
653 struct ext4_extent_header *eh;
654 struct ext4_extent *ex;
655 int i;
656
657 if (!path)
658 return;
659
660 eh = path[depth].p_hdr;
661 ex = EXT_FIRST_EXTENT(eh);
662
663 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
664
665 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
666 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
667 ext4_ext_is_unwritten(ex),
668 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
669 }
670 ext_debug("\n");
671}
672
673static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
674 ext4_fsblk_t newblock, int level)
675{
676 int depth = ext_depth(inode);
677 struct ext4_extent *ex;
678
679 if (depth != level) {
680 struct ext4_extent_idx *idx;
681 idx = path[level].p_idx;
682 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
683 ext_debug("%d: move %d:%llu in new index %llu\n", level,
684 le32_to_cpu(idx->ei_block),
685 ext4_idx_pblock(idx),
686 newblock);
687 idx++;
688 }
689
690 return;
691 }
692
693 ex = path[depth].p_ext;
694 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
695 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
696 le32_to_cpu(ex->ee_block),
697 ext4_ext_pblock(ex),
698 ext4_ext_is_unwritten(ex),
699 ext4_ext_get_actual_len(ex),
700 newblock);
701 ex++;
702 }
703}
704
705#else
706#define ext4_ext_show_path(inode, path)
707#define ext4_ext_show_leaf(inode, path)
708#define ext4_ext_show_move(inode, path, newblock, level)
709#endif
710
711void ext4_ext_drop_refs(struct ext4_ext_path *path)
712{
713 int depth, i;
714
715 if (!path)
716 return;
717 depth = path->p_depth;
718 for (i = 0; i <= depth; i++, path++)
719 if (path->p_bh) {
720 brelse(path->p_bh);
721 path->p_bh = NULL;
722 }
723}
724
725/*
726 * ext4_ext_binsearch_idx:
727 * binary search for the closest index of the given block
728 * the header must be checked before calling this
729 */
730static void
731ext4_ext_binsearch_idx(struct inode *inode,
732 struct ext4_ext_path *path, ext4_lblk_t block)
733{
734 struct ext4_extent_header *eh = path->p_hdr;
735 struct ext4_extent_idx *r, *l, *m;
736
737
738 ext_debug("binsearch for %u(idx): ", block);
739
740 l = EXT_FIRST_INDEX(eh) + 1;
741 r = EXT_LAST_INDEX(eh);
742 while (l <= r) {
743 m = l + (r - l) / 2;
744 if (block < le32_to_cpu(m->ei_block))
745 r = m - 1;
746 else
747 l = m + 1;
748 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
749 m, le32_to_cpu(m->ei_block),
750 r, le32_to_cpu(r->ei_block));
751 }
752
753 path->p_idx = l - 1;
754 ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
755 ext4_idx_pblock(path->p_idx));
756
757#ifdef CHECK_BINSEARCH
758 {
759 struct ext4_extent_idx *chix, *ix;
760 int k;
761
762 chix = ix = EXT_FIRST_INDEX(eh);
763 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
764 if (k != 0 &&
765 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
766 printk(KERN_DEBUG "k=%d, ix=0x%p, "
767 "first=0x%p\n", k,
768 ix, EXT_FIRST_INDEX(eh));
769 printk(KERN_DEBUG "%u <= %u\n",
770 le32_to_cpu(ix->ei_block),
771 le32_to_cpu(ix[-1].ei_block));
772 }
773 BUG_ON(k && le32_to_cpu(ix->ei_block)
774 <= le32_to_cpu(ix[-1].ei_block));
775 if (block < le32_to_cpu(ix->ei_block))
776 break;
777 chix = ix;
778 }
779 BUG_ON(chix != path->p_idx);
780 }
781#endif
782
783}
784
785/*
786 * ext4_ext_binsearch:
787 * binary search for closest extent of the given block
788 * the header must be checked before calling this
789 */
790static void
791ext4_ext_binsearch(struct inode *inode,
792 struct ext4_ext_path *path, ext4_lblk_t block)
793{
794 struct ext4_extent_header *eh = path->p_hdr;
795 struct ext4_extent *r, *l, *m;
796
797 if (eh->eh_entries == 0) {
798 /*
799 * this leaf is empty:
800 * we get such a leaf in split/add case
801 */
802 return;
803 }
804
805 ext_debug("binsearch for %u: ", block);
806
807 l = EXT_FIRST_EXTENT(eh) + 1;
808 r = EXT_LAST_EXTENT(eh);
809
810 while (l <= r) {
811 m = l + (r - l) / 2;
812 if (block < le32_to_cpu(m->ee_block))
813 r = m - 1;
814 else
815 l = m + 1;
816 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
817 m, le32_to_cpu(m->ee_block),
818 r, le32_to_cpu(r->ee_block));
819 }
820
821 path->p_ext = l - 1;
822 ext_debug(" -> %d:%llu:[%d]%d ",
823 le32_to_cpu(path->p_ext->ee_block),
824 ext4_ext_pblock(path->p_ext),
825 ext4_ext_is_unwritten(path->p_ext),
826 ext4_ext_get_actual_len(path->p_ext));
827
828#ifdef CHECK_BINSEARCH
829 {
830 struct ext4_extent *chex, *ex;
831 int k;
832
833 chex = ex = EXT_FIRST_EXTENT(eh);
834 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
835 BUG_ON(k && le32_to_cpu(ex->ee_block)
836 <= le32_to_cpu(ex[-1].ee_block));
837 if (block < le32_to_cpu(ex->ee_block))
838 break;
839 chex = ex;
840 }
841 BUG_ON(chex != path->p_ext);
842 }
843#endif
844
845}
846
847int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
848{
849 struct ext4_extent_header *eh;
850
851 eh = ext_inode_hdr(inode);
852 eh->eh_depth = 0;
853 eh->eh_entries = 0;
854 eh->eh_magic = EXT4_EXT_MAGIC;
855 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
856 ext4_mark_inode_dirty(handle, inode);
857 return 0;
858}
859
860struct ext4_ext_path *
861ext4_find_extent(struct inode *inode, ext4_lblk_t block,
862 struct ext4_ext_path **orig_path, int flags)
863{
864 struct ext4_extent_header *eh;
865 struct buffer_head *bh;
866 struct ext4_ext_path *path = orig_path ? *orig_path : NULL;
867 short int depth, i, ppos = 0;
868 int ret;
869
870 eh = ext_inode_hdr(inode);
871 depth = ext_depth(inode);
872
873 if (path) {
874 ext4_ext_drop_refs(path);
875 if (depth > path[0].p_maxdepth) {
876 kfree(path);
877 *orig_path = path = NULL;
878 }
879 }
880 if (!path) {
881 /* account possible depth increase */
882 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
883 GFP_NOFS);
884 if (unlikely(!path))
885 return ERR_PTR(-ENOMEM);
886 path[0].p_maxdepth = depth + 1;
887 }
888 path[0].p_hdr = eh;
889 path[0].p_bh = NULL;
890
891 i = depth;
892 /* walk through the tree */
893 while (i) {
894 ext_debug("depth %d: num %d, max %d\n",
895 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
896
897 ext4_ext_binsearch_idx(inode, path + ppos, block);
898 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
899 path[ppos].p_depth = i;
900 path[ppos].p_ext = NULL;
901
902 bh = read_extent_tree_block(inode, path[ppos].p_block, --i,
903 flags);
904 if (IS_ERR(bh)) {
905 ret = PTR_ERR(bh);
906 goto err;
907 }
908
909 eh = ext_block_hdr(bh);
910 ppos++;
911 path[ppos].p_bh = bh;
912 path[ppos].p_hdr = eh;
913 }
914
915 path[ppos].p_depth = i;
916 path[ppos].p_ext = NULL;
917 path[ppos].p_idx = NULL;
918
919 /* find extent */
920 ext4_ext_binsearch(inode, path + ppos, block);
921 /* if not an empty leaf */
922 if (path[ppos].p_ext)
923 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
924
925 ext4_ext_show_path(inode, path);
926
927 return path;
928
929err:
930 ext4_ext_drop_refs(path);
931 kfree(path);
932 if (orig_path)
933 *orig_path = NULL;
934 return ERR_PTR(ret);
935}
936
937/*
938 * ext4_ext_insert_index:
939 * insert new index [@logical;@ptr] into the block at @curp;
940 * check where to insert: before @curp or after @curp
941 */
942static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
943 struct ext4_ext_path *curp,
944 int logical, ext4_fsblk_t ptr)
945{
946 struct ext4_extent_idx *ix;
947 int len, err;
948
949 err = ext4_ext_get_access(handle, inode, curp);
950 if (err)
951 return err;
952
953 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
954 EXT4_ERROR_INODE(inode,
955 "logical %d == ei_block %d!",
956 logical, le32_to_cpu(curp->p_idx->ei_block));
957 return -EFSCORRUPTED;
958 }
959
960 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
961 >= le16_to_cpu(curp->p_hdr->eh_max))) {
962 EXT4_ERROR_INODE(inode,
963 "eh_entries %d >= eh_max %d!",
964 le16_to_cpu(curp->p_hdr->eh_entries),
965 le16_to_cpu(curp->p_hdr->eh_max));
966 return -EFSCORRUPTED;
967 }
968
969 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
970 /* insert after */
971 ext_debug("insert new index %d after: %llu\n", logical, ptr);
972 ix = curp->p_idx + 1;
973 } else {
974 /* insert before */
975 ext_debug("insert new index %d before: %llu\n", logical, ptr);
976 ix = curp->p_idx;
977 }
978
979 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
980 BUG_ON(len < 0);
981 if (len > 0) {
982 ext_debug("insert new index %d: "
983 "move %d indices from 0x%p to 0x%p\n",
984 logical, len, ix, ix + 1);
985 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
986 }
987
988 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
989 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
990 return -EFSCORRUPTED;
991 }
992
993 ix->ei_block = cpu_to_le32(logical);
994 ext4_idx_store_pblock(ix, ptr);
995 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
996
997 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
998 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
999 return -EFSCORRUPTED;
1000 }
1001
1002 err = ext4_ext_dirty(handle, inode, curp);
1003 ext4_std_error(inode->i_sb, err);
1004
1005 return err;
1006}
1007
1008/*
1009 * ext4_ext_split:
1010 * inserts new subtree into the path, using free index entry
1011 * at depth @at:
1012 * - allocates all needed blocks (new leaf and all intermediate index blocks)
1013 * - makes decision where to split
1014 * - moves remaining extents and index entries (right to the split point)
1015 * into the newly allocated blocks
1016 * - initializes subtree
1017 */
1018static int ext4_ext_split(handle_t *handle, struct inode *inode,
1019 unsigned int flags,
1020 struct ext4_ext_path *path,
1021 struct ext4_extent *newext, int at)
1022{
1023 struct buffer_head *bh = NULL;
1024 int depth = ext_depth(inode);
1025 struct ext4_extent_header *neh;
1026 struct ext4_extent_idx *fidx;
1027 int i = at, k, m, a;
1028 ext4_fsblk_t newblock, oldblock;
1029 __le32 border;
1030 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1031 int err = 0;
1032
1033 /* make decision: where to split? */
1034 /* FIXME: now decision is simplest: at current extent */
1035
1036 /* if current leaf will be split, then we should use
1037 * border from split point */
1038 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1039 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1040 return -EFSCORRUPTED;
1041 }
1042 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1043 border = path[depth].p_ext[1].ee_block;
1044 ext_debug("leaf will be split."
1045 " next leaf starts at %d\n",
1046 le32_to_cpu(border));
1047 } else {
1048 border = newext->ee_block;
1049 ext_debug("leaf will be added."
1050 " next leaf starts at %d\n",
1051 le32_to_cpu(border));
1052 }
1053
1054 /*
1055 * If error occurs, then we break processing
1056 * and mark filesystem read-only. index won't
1057 * be inserted and tree will be in consistent
1058 * state. Next mount will repair buffers too.
1059 */
1060
1061 /*
1062 * Get array to track all allocated blocks.
1063 * We need this to handle errors and free blocks
1064 * upon them.
1065 */
1066 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
1067 if (!ablocks)
1068 return -ENOMEM;
1069
1070 /* allocate all needed blocks */
1071 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
1072 for (a = 0; a < depth - at; a++) {
1073 newblock = ext4_ext_new_meta_block(handle, inode, path,
1074 newext, &err, flags);
1075 if (newblock == 0)
1076 goto cleanup;
1077 ablocks[a] = newblock;
1078 }
1079
1080 /* initialize new leaf */
1081 newblock = ablocks[--a];
1082 if (unlikely(newblock == 0)) {
1083 EXT4_ERROR_INODE(inode, "newblock == 0!");
1084 err = -EFSCORRUPTED;
1085 goto cleanup;
1086 }
1087 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1088 if (unlikely(!bh)) {
1089 err = -ENOMEM;
1090 goto cleanup;
1091 }
1092 lock_buffer(bh);
1093
1094 err = ext4_journal_get_create_access(handle, bh);
1095 if (err)
1096 goto cleanup;
1097
1098 neh = ext_block_hdr(bh);
1099 neh->eh_entries = 0;
1100 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1101 neh->eh_magic = EXT4_EXT_MAGIC;
1102 neh->eh_depth = 0;
1103
1104 /* move remainder of path[depth] to the new leaf */
1105 if (unlikely(path[depth].p_hdr->eh_entries !=
1106 path[depth].p_hdr->eh_max)) {
1107 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1108 path[depth].p_hdr->eh_entries,
1109 path[depth].p_hdr->eh_max);
1110 err = -EFSCORRUPTED;
1111 goto cleanup;
1112 }
1113 /* start copy from next extent */
1114 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1115 ext4_ext_show_move(inode, path, newblock, depth);
1116 if (m) {
1117 struct ext4_extent *ex;
1118 ex = EXT_FIRST_EXTENT(neh);
1119 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1120 le16_add_cpu(&neh->eh_entries, m);
1121 }
1122
1123 ext4_extent_block_csum_set(inode, neh);
1124 set_buffer_uptodate(bh);
1125 unlock_buffer(bh);
1126
1127 err = ext4_handle_dirty_metadata(handle, inode, bh);
1128 if (err)
1129 goto cleanup;
1130 brelse(bh);
1131 bh = NULL;
1132
1133 /* correct old leaf */
1134 if (m) {
1135 err = ext4_ext_get_access(handle, inode, path + depth);
1136 if (err)
1137 goto cleanup;
1138 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1139 err = ext4_ext_dirty(handle, inode, path + depth);
1140 if (err)
1141 goto cleanup;
1142
1143 }
1144
1145 /* create intermediate indexes */
1146 k = depth - at - 1;
1147 if (unlikely(k < 0)) {
1148 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1149 err = -EFSCORRUPTED;
1150 goto cleanup;
1151 }
1152 if (k)
1153 ext_debug("create %d intermediate indices\n", k);
1154 /* insert new index into current index block */
1155 /* current depth stored in i var */
1156 i = depth - 1;
1157 while (k--) {
1158 oldblock = newblock;
1159 newblock = ablocks[--a];
1160 bh = sb_getblk(inode->i_sb, newblock);
1161 if (unlikely(!bh)) {
1162 err = -ENOMEM;
1163 goto cleanup;
1164 }
1165 lock_buffer(bh);
1166
1167 err = ext4_journal_get_create_access(handle, bh);
1168 if (err)
1169 goto cleanup;
1170
1171 neh = ext_block_hdr(bh);
1172 neh->eh_entries = cpu_to_le16(1);
1173 neh->eh_magic = EXT4_EXT_MAGIC;
1174 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1175 neh->eh_depth = cpu_to_le16(depth - i);
1176 fidx = EXT_FIRST_INDEX(neh);
1177 fidx->ei_block = border;
1178 ext4_idx_store_pblock(fidx, oldblock);
1179
1180 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1181 i, newblock, le32_to_cpu(border), oldblock);
1182
1183 /* move remainder of path[i] to the new index block */
1184 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1185 EXT_LAST_INDEX(path[i].p_hdr))) {
1186 EXT4_ERROR_INODE(inode,
1187 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1188 le32_to_cpu(path[i].p_ext->ee_block));
1189 err = -EFSCORRUPTED;
1190 goto cleanup;
1191 }
1192 /* start copy indexes */
1193 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1194 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1195 EXT_MAX_INDEX(path[i].p_hdr));
1196 ext4_ext_show_move(inode, path, newblock, i);
1197 if (m) {
1198 memmove(++fidx, path[i].p_idx,
1199 sizeof(struct ext4_extent_idx) * m);
1200 le16_add_cpu(&neh->eh_entries, m);
1201 }
1202 ext4_extent_block_csum_set(inode, neh);
1203 set_buffer_uptodate(bh);
1204 unlock_buffer(bh);
1205
1206 err = ext4_handle_dirty_metadata(handle, inode, bh);
1207 if (err)
1208 goto cleanup;
1209 brelse(bh);
1210 bh = NULL;
1211
1212 /* correct old index */
1213 if (m) {
1214 err = ext4_ext_get_access(handle, inode, path + i);
1215 if (err)
1216 goto cleanup;
1217 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1218 err = ext4_ext_dirty(handle, inode, path + i);
1219 if (err)
1220 goto cleanup;
1221 }
1222
1223 i--;
1224 }
1225
1226 /* insert new index */
1227 err = ext4_ext_insert_index(handle, inode, path + at,
1228 le32_to_cpu(border), newblock);
1229
1230cleanup:
1231 if (bh) {
1232 if (buffer_locked(bh))
1233 unlock_buffer(bh);
1234 brelse(bh);
1235 }
1236
1237 if (err) {
1238 /* free all allocated blocks in error case */
1239 for (i = 0; i < depth; i++) {
1240 if (!ablocks[i])
1241 continue;
1242 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1243 EXT4_FREE_BLOCKS_METADATA);
1244 }
1245 }
1246 kfree(ablocks);
1247
1248 return err;
1249}
1250
1251/*
1252 * ext4_ext_grow_indepth:
1253 * implements tree growing procedure:
1254 * - allocates new block
1255 * - moves top-level data (index block or leaf) into the new block
1256 * - initializes new top-level, creating index that points to the
1257 * just created block
1258 */
1259static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1260 unsigned int flags)
1261{
1262 struct ext4_extent_header *neh;
1263 struct buffer_head *bh;
1264 ext4_fsblk_t newblock, goal = 0;
1265 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
1266 int err = 0;
1267
1268 /* Try to prepend new index to old one */
1269 if (ext_depth(inode))
1270 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
1271 if (goal > le32_to_cpu(es->s_first_data_block)) {
1272 flags |= EXT4_MB_HINT_TRY_GOAL;
1273 goal--;
1274 } else
1275 goal = ext4_inode_to_goal_block(inode);
1276 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
1277 NULL, &err);
1278 if (newblock == 0)
1279 return err;
1280
1281 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1282 if (unlikely(!bh))
1283 return -ENOMEM;
1284 lock_buffer(bh);
1285
1286 err = ext4_journal_get_create_access(handle, bh);
1287 if (err) {
1288 unlock_buffer(bh);
1289 goto out;
1290 }
1291
1292 /* move top-level index/leaf into new block */
1293 memmove(bh->b_data, EXT4_I(inode)->i_data,
1294 sizeof(EXT4_I(inode)->i_data));
1295
1296 /* set size of new block */
1297 neh = ext_block_hdr(bh);
1298 /* old root could have indexes or leaves
1299 * so calculate e_max right way */
1300 if (ext_depth(inode))
1301 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1302 else
1303 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1304 neh->eh_magic = EXT4_EXT_MAGIC;
1305 ext4_extent_block_csum_set(inode, neh);
1306 set_buffer_uptodate(bh);
1307 unlock_buffer(bh);
1308
1309 err = ext4_handle_dirty_metadata(handle, inode, bh);
1310 if (err)
1311 goto out;
1312
1313 /* Update top-level index: num,max,pointer */
1314 neh = ext_inode_hdr(inode);
1315 neh->eh_entries = cpu_to_le16(1);
1316 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1317 if (neh->eh_depth == 0) {
1318 /* Root extent block becomes index block */
1319 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1320 EXT_FIRST_INDEX(neh)->ei_block =
1321 EXT_FIRST_EXTENT(neh)->ee_block;
1322 }
1323 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1324 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1325 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1326 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1327
1328 le16_add_cpu(&neh->eh_depth, 1);
1329 ext4_mark_inode_dirty(handle, inode);
1330out:
1331 brelse(bh);
1332
1333 return err;
1334}
1335
1336/*
1337 * ext4_ext_create_new_leaf:
1338 * finds empty index and adds new leaf.
1339 * if no free index is found, then it requests in-depth growing.
1340 */
1341static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1342 unsigned int mb_flags,
1343 unsigned int gb_flags,
1344 struct ext4_ext_path **ppath,
1345 struct ext4_extent *newext)
1346{
1347 struct ext4_ext_path *path = *ppath;
1348 struct ext4_ext_path *curp;
1349 int depth, i, err = 0;
1350
1351repeat:
1352 i = depth = ext_depth(inode);
1353
1354 /* walk up to the tree and look for free index entry */
1355 curp = path + depth;
1356 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1357 i--;
1358 curp--;
1359 }
1360
1361 /* we use already allocated block for index block,
1362 * so subsequent data blocks should be contiguous */
1363 if (EXT_HAS_FREE_INDEX(curp)) {
1364 /* if we found index with free entry, then use that
1365 * entry: create all needed subtree and add new leaf */
1366 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
1367 if (err)
1368 goto out;
1369
1370 /* refill path */
1371 path = ext4_find_extent(inode,
1372 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1373 ppath, gb_flags);
1374 if (IS_ERR(path))
1375 err = PTR_ERR(path);
1376 } else {
1377 /* tree is full, time to grow in depth */
1378 err = ext4_ext_grow_indepth(handle, inode, mb_flags);
1379 if (err)
1380 goto out;
1381
1382 /* refill path */
1383 path = ext4_find_extent(inode,
1384 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1385 ppath, gb_flags);
1386 if (IS_ERR(path)) {
1387 err = PTR_ERR(path);
1388 goto out;
1389 }
1390
1391 /*
1392 * only first (depth 0 -> 1) produces free space;
1393 * in all other cases we have to split the grown tree
1394 */
1395 depth = ext_depth(inode);
1396 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1397 /* now we need to split */
1398 goto repeat;
1399 }
1400 }
1401
1402out:
1403 return err;
1404}
1405
1406/*
1407 * search the closest allocated block to the left for *logical
1408 * and returns it at @logical + it's physical address at @phys
1409 * if *logical is the smallest allocated block, the function
1410 * returns 0 at @phys
1411 * return value contains 0 (success) or error code
1412 */
1413static int ext4_ext_search_left(struct inode *inode,
1414 struct ext4_ext_path *path,
1415 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1416{
1417 struct ext4_extent_idx *ix;
1418 struct ext4_extent *ex;
1419 int depth, ee_len;
1420
1421 if (unlikely(path == NULL)) {
1422 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1423 return -EFSCORRUPTED;
1424 }
1425 depth = path->p_depth;
1426 *phys = 0;
1427
1428 if (depth == 0 && path->p_ext == NULL)
1429 return 0;
1430
1431 /* usually extent in the path covers blocks smaller
1432 * then *logical, but it can be that extent is the
1433 * first one in the file */
1434
1435 ex = path[depth].p_ext;
1436 ee_len = ext4_ext_get_actual_len(ex);
1437 if (*logical < le32_to_cpu(ex->ee_block)) {
1438 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1439 EXT4_ERROR_INODE(inode,
1440 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1441 *logical, le32_to_cpu(ex->ee_block));
1442 return -EFSCORRUPTED;
1443 }
1444 while (--depth >= 0) {
1445 ix = path[depth].p_idx;
1446 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1447 EXT4_ERROR_INODE(inode,
1448 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1449 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1450 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1451 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1452 depth);
1453 return -EFSCORRUPTED;
1454 }
1455 }
1456 return 0;
1457 }
1458
1459 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1460 EXT4_ERROR_INODE(inode,
1461 "logical %d < ee_block %d + ee_len %d!",
1462 *logical, le32_to_cpu(ex->ee_block), ee_len);
1463 return -EFSCORRUPTED;
1464 }
1465
1466 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1467 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1468 return 0;
1469}
1470
1471/*
1472 * search the closest allocated block to the right for *logical
1473 * and returns it at @logical + it's physical address at @phys
1474 * if *logical is the largest allocated block, the function
1475 * returns 0 at @phys
1476 * return value contains 0 (success) or error code
1477 */
1478static int ext4_ext_search_right(struct inode *inode,
1479 struct ext4_ext_path *path,
1480 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1481 struct ext4_extent **ret_ex)
1482{
1483 struct buffer_head *bh = NULL;
1484 struct ext4_extent_header *eh;
1485 struct ext4_extent_idx *ix;
1486 struct ext4_extent *ex;
1487 ext4_fsblk_t block;
1488 int depth; /* Note, NOT eh_depth; depth from top of tree */
1489 int ee_len;
1490
1491 if (unlikely(path == NULL)) {
1492 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1493 return -EFSCORRUPTED;
1494 }
1495 depth = path->p_depth;
1496 *phys = 0;
1497
1498 if (depth == 0 && path->p_ext == NULL)
1499 return 0;
1500
1501 /* usually extent in the path covers blocks smaller
1502 * then *logical, but it can be that extent is the
1503 * first one in the file */
1504
1505 ex = path[depth].p_ext;
1506 ee_len = ext4_ext_get_actual_len(ex);
1507 if (*logical < le32_to_cpu(ex->ee_block)) {
1508 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1509 EXT4_ERROR_INODE(inode,
1510 "first_extent(path[%d].p_hdr) != ex",
1511 depth);
1512 return -EFSCORRUPTED;
1513 }
1514 while (--depth >= 0) {
1515 ix = path[depth].p_idx;
1516 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1517 EXT4_ERROR_INODE(inode,
1518 "ix != EXT_FIRST_INDEX *logical %d!",
1519 *logical);
1520 return -EFSCORRUPTED;
1521 }
1522 }
1523 goto found_extent;
1524 }
1525
1526 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1527 EXT4_ERROR_INODE(inode,
1528 "logical %d < ee_block %d + ee_len %d!",
1529 *logical, le32_to_cpu(ex->ee_block), ee_len);
1530 return -EFSCORRUPTED;
1531 }
1532
1533 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1534 /* next allocated block in this leaf */
1535 ex++;
1536 goto found_extent;
1537 }
1538
1539 /* go up and search for index to the right */
1540 while (--depth >= 0) {
1541 ix = path[depth].p_idx;
1542 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1543 goto got_index;
1544 }
1545
1546 /* we've gone up to the root and found no index to the right */
1547 return 0;
1548
1549got_index:
1550 /* we've found index to the right, let's
1551 * follow it and find the closest allocated
1552 * block to the right */
1553 ix++;
1554 block = ext4_idx_pblock(ix);
1555 while (++depth < path->p_depth) {
1556 /* subtract from p_depth to get proper eh_depth */
1557 bh = read_extent_tree_block(inode, block,
1558 path->p_depth - depth, 0);
1559 if (IS_ERR(bh))
1560 return PTR_ERR(bh);
1561 eh = ext_block_hdr(bh);
1562 ix = EXT_FIRST_INDEX(eh);
1563 block = ext4_idx_pblock(ix);
1564 put_bh(bh);
1565 }
1566
1567 bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0);
1568 if (IS_ERR(bh))
1569 return PTR_ERR(bh);
1570 eh = ext_block_hdr(bh);
1571 ex = EXT_FIRST_EXTENT(eh);
1572found_extent:
1573 *logical = le32_to_cpu(ex->ee_block);
1574 *phys = ext4_ext_pblock(ex);
1575 *ret_ex = ex;
1576 if (bh)
1577 put_bh(bh);
1578 return 0;
1579}
1580
1581/*
1582 * ext4_ext_next_allocated_block:
1583 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1584 * NOTE: it considers block number from index entry as
1585 * allocated block. Thus, index entries have to be consistent
1586 * with leaves.
1587 */
1588ext4_lblk_t
1589ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1590{
1591 int depth;
1592
1593 BUG_ON(path == NULL);
1594 depth = path->p_depth;
1595
1596 if (depth == 0 && path->p_ext == NULL)
1597 return EXT_MAX_BLOCKS;
1598
1599 while (depth >= 0) {
1600 if (depth == path->p_depth) {
1601 /* leaf */
1602 if (path[depth].p_ext &&
1603 path[depth].p_ext !=
1604 EXT_LAST_EXTENT(path[depth].p_hdr))
1605 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1606 } else {
1607 /* index */
1608 if (path[depth].p_idx !=
1609 EXT_LAST_INDEX(path[depth].p_hdr))
1610 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1611 }
1612 depth--;
1613 }
1614
1615 return EXT_MAX_BLOCKS;
1616}
1617
1618/*
1619 * ext4_ext_next_leaf_block:
1620 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1621 */
1622static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1623{
1624 int depth;
1625
1626 BUG_ON(path == NULL);
1627 depth = path->p_depth;
1628
1629 /* zero-tree has no leaf blocks at all */
1630 if (depth == 0)
1631 return EXT_MAX_BLOCKS;
1632
1633 /* go to index block */
1634 depth--;
1635
1636 while (depth >= 0) {
1637 if (path[depth].p_idx !=
1638 EXT_LAST_INDEX(path[depth].p_hdr))
1639 return (ext4_lblk_t)
1640 le32_to_cpu(path[depth].p_idx[1].ei_block);
1641 depth--;
1642 }
1643
1644 return EXT_MAX_BLOCKS;
1645}
1646
1647/*
1648 * ext4_ext_correct_indexes:
1649 * if leaf gets modified and modified extent is first in the leaf,
1650 * then we have to correct all indexes above.
1651 * TODO: do we need to correct tree in all cases?
1652 */
1653static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1654 struct ext4_ext_path *path)
1655{
1656 struct ext4_extent_header *eh;
1657 int depth = ext_depth(inode);
1658 struct ext4_extent *ex;
1659 __le32 border;
1660 int k, err = 0;
1661
1662 eh = path[depth].p_hdr;
1663 ex = path[depth].p_ext;
1664
1665 if (unlikely(ex == NULL || eh == NULL)) {
1666 EXT4_ERROR_INODE(inode,
1667 "ex %p == NULL or eh %p == NULL", ex, eh);
1668 return -EFSCORRUPTED;
1669 }
1670
1671 if (depth == 0) {
1672 /* there is no tree at all */
1673 return 0;
1674 }
1675
1676 if (ex != EXT_FIRST_EXTENT(eh)) {
1677 /* we correct tree if first leaf got modified only */
1678 return 0;
1679 }
1680
1681 /*
1682 * TODO: we need correction if border is smaller than current one
1683 */
1684 k = depth - 1;
1685 border = path[depth].p_ext->ee_block;
1686 err = ext4_ext_get_access(handle, inode, path + k);
1687 if (err)
1688 return err;
1689 path[k].p_idx->ei_block = border;
1690 err = ext4_ext_dirty(handle, inode, path + k);
1691 if (err)
1692 return err;
1693
1694 while (k--) {
1695 /* change all left-side indexes */
1696 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1697 break;
1698 err = ext4_ext_get_access(handle, inode, path + k);
1699 if (err)
1700 break;
1701 path[k].p_idx->ei_block = border;
1702 err = ext4_ext_dirty(handle, inode, path + k);
1703 if (err)
1704 break;
1705 }
1706
1707 return err;
1708}
1709
1710int
1711ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1712 struct ext4_extent *ex2)
1713{
1714 unsigned short ext1_ee_len, ext2_ee_len;
1715
1716 if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
1717 return 0;
1718
1719 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1720 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1721
1722 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1723 le32_to_cpu(ex2->ee_block))
1724 return 0;
1725
1726 /*
1727 * To allow future support for preallocated extents to be added
1728 * as an RO_COMPAT feature, refuse to merge to extents if
1729 * this can result in the top bit of ee_len being set.
1730 */
1731 if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1732 return 0;
1733 /*
1734 * The check for IO to unwritten extent is somewhat racy as we
1735 * increment i_unwritten / set EXT4_STATE_DIO_UNWRITTEN only after
1736 * dropping i_data_sem. But reserved blocks should save us in that
1737 * case.
1738 */
1739 if (ext4_ext_is_unwritten(ex1) &&
1740 (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) ||
1741 atomic_read(&EXT4_I(inode)->i_unwritten) ||
1742 (ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)))
1743 return 0;
1744#ifdef AGGRESSIVE_TEST
1745 if (ext1_ee_len >= 4)
1746 return 0;
1747#endif
1748
1749 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1750 return 1;
1751 return 0;
1752}
1753
1754/*
1755 * This function tries to merge the "ex" extent to the next extent in the tree.
1756 * It always tries to merge towards right. If you want to merge towards
1757 * left, pass "ex - 1" as argument instead of "ex".
1758 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1759 * 1 if they got merged.
1760 */
1761static int ext4_ext_try_to_merge_right(struct inode *inode,
1762 struct ext4_ext_path *path,
1763 struct ext4_extent *ex)
1764{
1765 struct ext4_extent_header *eh;
1766 unsigned int depth, len;
1767 int merge_done = 0, unwritten;
1768
1769 depth = ext_depth(inode);
1770 BUG_ON(path[depth].p_hdr == NULL);
1771 eh = path[depth].p_hdr;
1772
1773 while (ex < EXT_LAST_EXTENT(eh)) {
1774 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1775 break;
1776 /* merge with next extent! */
1777 unwritten = ext4_ext_is_unwritten(ex);
1778 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1779 + ext4_ext_get_actual_len(ex + 1));
1780 if (unwritten)
1781 ext4_ext_mark_unwritten(ex);
1782
1783 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1784 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1785 * sizeof(struct ext4_extent);
1786 memmove(ex + 1, ex + 2, len);
1787 }
1788 le16_add_cpu(&eh->eh_entries, -1);
1789 merge_done = 1;
1790 WARN_ON(eh->eh_entries == 0);
1791 if (!eh->eh_entries)
1792 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1793 }
1794
1795 return merge_done;
1796}
1797
1798/*
1799 * This function does a very simple check to see if we can collapse
1800 * an extent tree with a single extent tree leaf block into the inode.
1801 */
1802static void ext4_ext_try_to_merge_up(handle_t *handle,
1803 struct inode *inode,
1804 struct ext4_ext_path *path)
1805{
1806 size_t s;
1807 unsigned max_root = ext4_ext_space_root(inode, 0);
1808 ext4_fsblk_t blk;
1809
1810 if ((path[0].p_depth != 1) ||
1811 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1812 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1813 return;
1814
1815 /*
1816 * We need to modify the block allocation bitmap and the block
1817 * group descriptor to release the extent tree block. If we
1818 * can't get the journal credits, give up.
1819 */
1820 if (ext4_journal_extend(handle, 2))
1821 return;
1822
1823 /*
1824 * Copy the extent data up to the inode
1825 */
1826 blk = ext4_idx_pblock(path[0].p_idx);
1827 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1828 sizeof(struct ext4_extent_idx);
1829 s += sizeof(struct ext4_extent_header);
1830
1831 path[1].p_maxdepth = path[0].p_maxdepth;
1832 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1833 path[0].p_depth = 0;
1834 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1835 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1836 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1837
1838 brelse(path[1].p_bh);
1839 ext4_free_blocks(handle, inode, NULL, blk, 1,
1840 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1841}
1842
1843/*
1844 * This function tries to merge the @ex extent to neighbours in the tree.
1845 * return 1 if merge left else 0.
1846 */
1847static void ext4_ext_try_to_merge(handle_t *handle,
1848 struct inode *inode,
1849 struct ext4_ext_path *path,
1850 struct ext4_extent *ex) {
1851 struct ext4_extent_header *eh;
1852 unsigned int depth;
1853 int merge_done = 0;
1854
1855 depth = ext_depth(inode);
1856 BUG_ON(path[depth].p_hdr == NULL);
1857 eh = path[depth].p_hdr;
1858
1859 if (ex > EXT_FIRST_EXTENT(eh))
1860 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1861
1862 if (!merge_done)
1863 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1864
1865 ext4_ext_try_to_merge_up(handle, inode, path);
1866}
1867
1868/*
1869 * check if a portion of the "newext" extent overlaps with an
1870 * existing extent.
1871 *
1872 * If there is an overlap discovered, it updates the length of the newext
1873 * such that there will be no overlap, and then returns 1.
1874 * If there is no overlap found, it returns 0.
1875 */
1876static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1877 struct inode *inode,
1878 struct ext4_extent *newext,
1879 struct ext4_ext_path *path)
1880{
1881 ext4_lblk_t b1, b2;
1882 unsigned int depth, len1;
1883 unsigned int ret = 0;
1884
1885 b1 = le32_to_cpu(newext->ee_block);
1886 len1 = ext4_ext_get_actual_len(newext);
1887 depth = ext_depth(inode);
1888 if (!path[depth].p_ext)
1889 goto out;
1890 b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
1891
1892 /*
1893 * get the next allocated block if the extent in the path
1894 * is before the requested block(s)
1895 */
1896 if (b2 < b1) {
1897 b2 = ext4_ext_next_allocated_block(path);
1898 if (b2 == EXT_MAX_BLOCKS)
1899 goto out;
1900 b2 = EXT4_LBLK_CMASK(sbi, b2);
1901 }
1902
1903 /* check for wrap through zero on extent logical start block*/
1904 if (b1 + len1 < b1) {
1905 len1 = EXT_MAX_BLOCKS - b1;
1906 newext->ee_len = cpu_to_le16(len1);
1907 ret = 1;
1908 }
1909
1910 /* check for overlap */
1911 if (b1 + len1 > b2) {
1912 newext->ee_len = cpu_to_le16(b2 - b1);
1913 ret = 1;
1914 }
1915out:
1916 return ret;
1917}
1918
1919/*
1920 * ext4_ext_insert_extent:
1921 * tries to merge requsted extent into the existing extent or
1922 * inserts requested extent as new one into the tree,
1923 * creating new leaf in the no-space case.
1924 */
1925int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1926 struct ext4_ext_path **ppath,
1927 struct ext4_extent *newext, int gb_flags)
1928{
1929 struct ext4_ext_path *path = *ppath;
1930 struct ext4_extent_header *eh;
1931 struct ext4_extent *ex, *fex;
1932 struct ext4_extent *nearex; /* nearest extent */
1933 struct ext4_ext_path *npath = NULL;
1934 int depth, len, err;
1935 ext4_lblk_t next;
1936 int mb_flags = 0, unwritten;
1937
1938 if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1939 mb_flags |= EXT4_MB_DELALLOC_RESERVED;
1940 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1941 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1942 return -EFSCORRUPTED;
1943 }
1944 depth = ext_depth(inode);
1945 ex = path[depth].p_ext;
1946 eh = path[depth].p_hdr;
1947 if (unlikely(path[depth].p_hdr == NULL)) {
1948 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1949 return -EFSCORRUPTED;
1950 }
1951
1952 /* try to insert block into found extent and return */
1953 if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
1954
1955 /*
1956 * Try to see whether we should rather test the extent on
1957 * right from ex, or from the left of ex. This is because
1958 * ext4_find_extent() can return either extent on the
1959 * left, or on the right from the searched position. This
1960 * will make merging more effective.
1961 */
1962 if (ex < EXT_LAST_EXTENT(eh) &&
1963 (le32_to_cpu(ex->ee_block) +
1964 ext4_ext_get_actual_len(ex) <
1965 le32_to_cpu(newext->ee_block))) {
1966 ex += 1;
1967 goto prepend;
1968 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
1969 (le32_to_cpu(newext->ee_block) +
1970 ext4_ext_get_actual_len(newext) <
1971 le32_to_cpu(ex->ee_block)))
1972 ex -= 1;
1973
1974 /* Try to append newex to the ex */
1975 if (ext4_can_extents_be_merged(inode, ex, newext)) {
1976 ext_debug("append [%d]%d block to %u:[%d]%d"
1977 "(from %llu)\n",
1978 ext4_ext_is_unwritten(newext),
1979 ext4_ext_get_actual_len(newext),
1980 le32_to_cpu(ex->ee_block),
1981 ext4_ext_is_unwritten(ex),
1982 ext4_ext_get_actual_len(ex),
1983 ext4_ext_pblock(ex));
1984 err = ext4_ext_get_access(handle, inode,
1985 path + depth);
1986 if (err)
1987 return err;
1988 unwritten = ext4_ext_is_unwritten(ex);
1989 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1990 + ext4_ext_get_actual_len(newext));
1991 if (unwritten)
1992 ext4_ext_mark_unwritten(ex);
1993 eh = path[depth].p_hdr;
1994 nearex = ex;
1995 goto merge;
1996 }
1997
1998prepend:
1999 /* Try to prepend newex to the ex */
2000 if (ext4_can_extents_be_merged(inode, newext, ex)) {
2001 ext_debug("prepend %u[%d]%d block to %u:[%d]%d"
2002 "(from %llu)\n",
2003 le32_to_cpu(newext->ee_block),
2004 ext4_ext_is_unwritten(newext),
2005 ext4_ext_get_actual_len(newext),
2006 le32_to_cpu(ex->ee_block),
2007 ext4_ext_is_unwritten(ex),
2008 ext4_ext_get_actual_len(ex),
2009 ext4_ext_pblock(ex));
2010 err = ext4_ext_get_access(handle, inode,
2011 path + depth);
2012 if (err)
2013 return err;
2014
2015 unwritten = ext4_ext_is_unwritten(ex);
2016 ex->ee_block = newext->ee_block;
2017 ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
2018 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2019 + ext4_ext_get_actual_len(newext));
2020 if (unwritten)
2021 ext4_ext_mark_unwritten(ex);
2022 eh = path[depth].p_hdr;
2023 nearex = ex;
2024 goto merge;
2025 }
2026 }
2027
2028 depth = ext_depth(inode);
2029 eh = path[depth].p_hdr;
2030 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
2031 goto has_space;
2032
2033 /* probably next leaf has space for us? */
2034 fex = EXT_LAST_EXTENT(eh);
2035 next = EXT_MAX_BLOCKS;
2036 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
2037 next = ext4_ext_next_leaf_block(path);
2038 if (next != EXT_MAX_BLOCKS) {
2039 ext_debug("next leaf block - %u\n", next);
2040 BUG_ON(npath != NULL);
2041 npath = ext4_find_extent(inode, next, NULL, 0);
2042 if (IS_ERR(npath))
2043 return PTR_ERR(npath);
2044 BUG_ON(npath->p_depth != path->p_depth);
2045 eh = npath[depth].p_hdr;
2046 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2047 ext_debug("next leaf isn't full(%d)\n",
2048 le16_to_cpu(eh->eh_entries));
2049 path = npath;
2050 goto has_space;
2051 }
2052 ext_debug("next leaf has no free space(%d,%d)\n",
2053 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2054 }
2055
2056 /*
2057 * There is no free space in the found leaf.
2058 * We're gonna add a new leaf in the tree.
2059 */
2060 if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2061 mb_flags |= EXT4_MB_USE_RESERVED;
2062 err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2063 ppath, newext);
2064 if (err)
2065 goto cleanup;
2066 depth = ext_depth(inode);
2067 eh = path[depth].p_hdr;
2068
2069has_space:
2070 nearex = path[depth].p_ext;
2071
2072 err = ext4_ext_get_access(handle, inode, path + depth);
2073 if (err)
2074 goto cleanup;
2075
2076 if (!nearex) {
2077 /* there is no extent in this leaf, create first one */
2078 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
2079 le32_to_cpu(newext->ee_block),
2080 ext4_ext_pblock(newext),
2081 ext4_ext_is_unwritten(newext),
2082 ext4_ext_get_actual_len(newext));
2083 nearex = EXT_FIRST_EXTENT(eh);
2084 } else {
2085 if (le32_to_cpu(newext->ee_block)
2086 > le32_to_cpu(nearex->ee_block)) {
2087 /* Insert after */
2088 ext_debug("insert %u:%llu:[%d]%d before: "
2089 "nearest %p\n",
2090 le32_to_cpu(newext->ee_block),
2091 ext4_ext_pblock(newext),
2092 ext4_ext_is_unwritten(newext),
2093 ext4_ext_get_actual_len(newext),
2094 nearex);
2095 nearex++;
2096 } else {
2097 /* Insert before */
2098 BUG_ON(newext->ee_block == nearex->ee_block);
2099 ext_debug("insert %u:%llu:[%d]%d after: "
2100 "nearest %p\n",
2101 le32_to_cpu(newext->ee_block),
2102 ext4_ext_pblock(newext),
2103 ext4_ext_is_unwritten(newext),
2104 ext4_ext_get_actual_len(newext),
2105 nearex);
2106 }
2107 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2108 if (len > 0) {
2109 ext_debug("insert %u:%llu:[%d]%d: "
2110 "move %d extents from 0x%p to 0x%p\n",
2111 le32_to_cpu(newext->ee_block),
2112 ext4_ext_pblock(newext),
2113 ext4_ext_is_unwritten(newext),
2114 ext4_ext_get_actual_len(newext),
2115 len, nearex, nearex + 1);
2116 memmove(nearex + 1, nearex,
2117 len * sizeof(struct ext4_extent));
2118 }
2119 }
2120
2121 le16_add_cpu(&eh->eh_entries, 1);
2122 path[depth].p_ext = nearex;
2123 nearex->ee_block = newext->ee_block;
2124 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2125 nearex->ee_len = newext->ee_len;
2126
2127merge:
2128 /* try to merge extents */
2129 if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2130 ext4_ext_try_to_merge(handle, inode, path, nearex);
2131
2132
2133 /* time to correct all indexes above */
2134 err = ext4_ext_correct_indexes(handle, inode, path);
2135 if (err)
2136 goto cleanup;
2137
2138 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2139
2140cleanup:
2141 ext4_ext_drop_refs(npath);
2142 kfree(npath);
2143 return err;
2144}
2145
2146static int ext4_fill_fiemap_extents(struct inode *inode,
2147 ext4_lblk_t block, ext4_lblk_t num,
2148 struct fiemap_extent_info *fieinfo)
2149{
2150 struct ext4_ext_path *path = NULL;
2151 struct ext4_extent *ex;
2152 struct extent_status es;
2153 ext4_lblk_t next, next_del, start = 0, end = 0;
2154 ext4_lblk_t last = block + num;
2155 int exists, depth = 0, err = 0;
2156 unsigned int flags = 0;
2157 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2158
2159 while (block < last && block != EXT_MAX_BLOCKS) {
2160 num = last - block;
2161 /* find extent for this block */
2162 down_read(&EXT4_I(inode)->i_data_sem);
2163
2164 path = ext4_find_extent(inode, block, &path, 0);
2165 if (IS_ERR(path)) {
2166 up_read(&EXT4_I(inode)->i_data_sem);
2167 err = PTR_ERR(path);
2168 path = NULL;
2169 break;
2170 }
2171
2172 depth = ext_depth(inode);
2173 if (unlikely(path[depth].p_hdr == NULL)) {
2174 up_read(&EXT4_I(inode)->i_data_sem);
2175 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2176 err = -EFSCORRUPTED;
2177 break;
2178 }
2179 ex = path[depth].p_ext;
2180 next = ext4_ext_next_allocated_block(path);
2181
2182 flags = 0;
2183 exists = 0;
2184 if (!ex) {
2185 /* there is no extent yet, so try to allocate
2186 * all requested space */
2187 start = block;
2188 end = block + num;
2189 } else if (le32_to_cpu(ex->ee_block) > block) {
2190 /* need to allocate space before found extent */
2191 start = block;
2192 end = le32_to_cpu(ex->ee_block);
2193 if (block + num < end)
2194 end = block + num;
2195 } else if (block >= le32_to_cpu(ex->ee_block)
2196 + ext4_ext_get_actual_len(ex)) {
2197 /* need to allocate space after found extent */
2198 start = block;
2199 end = block + num;
2200 if (end >= next)
2201 end = next;
2202 } else if (block >= le32_to_cpu(ex->ee_block)) {
2203 /*
2204 * some part of requested space is covered
2205 * by found extent
2206 */
2207 start = block;
2208 end = le32_to_cpu(ex->ee_block)
2209 + ext4_ext_get_actual_len(ex);
2210 if (block + num < end)
2211 end = block + num;
2212 exists = 1;
2213 } else {
2214 BUG();
2215 }
2216 BUG_ON(end <= start);
2217
2218 if (!exists) {
2219 es.es_lblk = start;
2220 es.es_len = end - start;
2221 es.es_pblk = 0;
2222 } else {
2223 es.es_lblk = le32_to_cpu(ex->ee_block);
2224 es.es_len = ext4_ext_get_actual_len(ex);
2225 es.es_pblk = ext4_ext_pblock(ex);
2226 if (ext4_ext_is_unwritten(ex))
2227 flags |= FIEMAP_EXTENT_UNWRITTEN;
2228 }
2229
2230 /*
2231 * Find delayed extent and update es accordingly. We call
2232 * it even in !exists case to find out whether es is the
2233 * last existing extent or not.
2234 */
2235 next_del = ext4_find_delayed_extent(inode, &es);
2236 if (!exists && next_del) {
2237 exists = 1;
2238 flags |= (FIEMAP_EXTENT_DELALLOC |
2239 FIEMAP_EXTENT_UNKNOWN);
2240 }
2241 up_read(&EXT4_I(inode)->i_data_sem);
2242
2243 if (unlikely(es.es_len == 0)) {
2244 EXT4_ERROR_INODE(inode, "es.es_len == 0");
2245 err = -EFSCORRUPTED;
2246 break;
2247 }
2248
2249 /*
2250 * This is possible iff next == next_del == EXT_MAX_BLOCKS.
2251 * we need to check next == EXT_MAX_BLOCKS because it is
2252 * possible that an extent is with unwritten and delayed
2253 * status due to when an extent is delayed allocated and
2254 * is allocated by fallocate status tree will track both of
2255 * them in a extent.
2256 *
2257 * So we could return a unwritten and delayed extent, and
2258 * its block is equal to 'next'.
2259 */
2260 if (next == next_del && next == EXT_MAX_BLOCKS) {
2261 flags |= FIEMAP_EXTENT_LAST;
2262 if (unlikely(next_del != EXT_MAX_BLOCKS ||
2263 next != EXT_MAX_BLOCKS)) {
2264 EXT4_ERROR_INODE(inode,
2265 "next extent == %u, next "
2266 "delalloc extent = %u",
2267 next, next_del);
2268 err = -EFSCORRUPTED;
2269 break;
2270 }
2271 }
2272
2273 if (exists) {
2274 err = fiemap_fill_next_extent(fieinfo,
2275 (__u64)es.es_lblk << blksize_bits,
2276 (__u64)es.es_pblk << blksize_bits,
2277 (__u64)es.es_len << blksize_bits,
2278 flags);
2279 if (err < 0)
2280 break;
2281 if (err == 1) {
2282 err = 0;
2283 break;
2284 }
2285 }
2286
2287 block = es.es_lblk + es.es_len;
2288 }
2289
2290 ext4_ext_drop_refs(path);
2291 kfree(path);
2292 return err;
2293}
2294
2295/*
2296 * ext4_ext_determine_hole - determine hole around given block
2297 * @inode: inode we lookup in
2298 * @path: path in extent tree to @lblk
2299 * @lblk: pointer to logical block around which we want to determine hole
2300 *
2301 * Determine hole length (and start if easily possible) around given logical
2302 * block. We don't try too hard to find the beginning of the hole but @path
2303 * actually points to extent before @lblk, we provide it.
2304 *
2305 * The function returns the length of a hole starting at @lblk. We update @lblk
2306 * to the beginning of the hole if we managed to find it.
2307 */
2308static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode,
2309 struct ext4_ext_path *path,
2310 ext4_lblk_t *lblk)
2311{
2312 int depth = ext_depth(inode);
2313 struct ext4_extent *ex;
2314 ext4_lblk_t len;
2315
2316 ex = path[depth].p_ext;
2317 if (ex == NULL) {
2318 /* there is no extent yet, so gap is [0;-] */
2319 *lblk = 0;
2320 len = EXT_MAX_BLOCKS;
2321 } else if (*lblk < le32_to_cpu(ex->ee_block)) {
2322 len = le32_to_cpu(ex->ee_block) - *lblk;
2323 } else if (*lblk >= le32_to_cpu(ex->ee_block)
2324 + ext4_ext_get_actual_len(ex)) {
2325 ext4_lblk_t next;
2326
2327 *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
2328 next = ext4_ext_next_allocated_block(path);
2329 BUG_ON(next == *lblk);
2330 len = next - *lblk;
2331 } else {
2332 BUG();
2333 }
2334 return len;
2335}
2336
2337/*
2338 * ext4_ext_put_gap_in_cache:
2339 * calculate boundaries of the gap that the requested block fits into
2340 * and cache this gap
2341 */
2342static void
2343ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start,
2344 ext4_lblk_t hole_len)
2345{
2346 struct extent_status es;
2347
2348 ext4_es_find_delayed_extent_range(inode, hole_start,
2349 hole_start + hole_len - 1, &es);
2350 if (es.es_len) {
2351 /* There's delayed extent containing lblock? */
2352 if (es.es_lblk <= hole_start)
2353 return;
2354 hole_len = min(es.es_lblk - hole_start, hole_len);
2355 }
2356 ext_debug(" -> %u:%u\n", hole_start, hole_len);
2357 ext4_es_insert_extent(inode, hole_start, hole_len, ~0,
2358 EXTENT_STATUS_HOLE);
2359}
2360
2361/*
2362 * ext4_ext_rm_idx:
2363 * removes index from the index block.
2364 */
2365static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2366 struct ext4_ext_path *path, int depth)
2367{
2368 int err;
2369 ext4_fsblk_t leaf;
2370
2371 /* free index block */
2372 depth--;
2373 path = path + depth;
2374 leaf = ext4_idx_pblock(path->p_idx);
2375 if (unlikely(path->p_hdr->eh_entries == 0)) {
2376 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2377 return -EFSCORRUPTED;
2378 }
2379 err = ext4_ext_get_access(handle, inode, path);
2380 if (err)
2381 return err;
2382
2383 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2384 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2385 len *= sizeof(struct ext4_extent_idx);
2386 memmove(path->p_idx, path->p_idx + 1, len);
2387 }
2388
2389 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2390 err = ext4_ext_dirty(handle, inode, path);
2391 if (err)
2392 return err;
2393 ext_debug("index is empty, remove it, free block %llu\n", leaf);
2394 trace_ext4_ext_rm_idx(inode, leaf);
2395
2396 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2397 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2398
2399 while (--depth >= 0) {
2400 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2401 break;
2402 path--;
2403 err = ext4_ext_get_access(handle, inode, path);
2404 if (err)
2405 break;
2406 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2407 err = ext4_ext_dirty(handle, inode, path);
2408 if (err)
2409 break;
2410 }
2411 return err;
2412}
2413
2414/*
2415 * ext4_ext_calc_credits_for_single_extent:
2416 * This routine returns max. credits that needed to insert an extent
2417 * to the extent tree.
2418 * When pass the actual path, the caller should calculate credits
2419 * under i_data_sem.
2420 */
2421int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2422 struct ext4_ext_path *path)
2423{
2424 if (path) {
2425 int depth = ext_depth(inode);
2426 int ret = 0;
2427
2428 /* probably there is space in leaf? */
2429 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2430 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2431
2432 /*
2433 * There are some space in the leaf tree, no
2434 * need to account for leaf block credit
2435 *
2436 * bitmaps and block group descriptor blocks
2437 * and other metadata blocks still need to be
2438 * accounted.
2439 */
2440 /* 1 bitmap, 1 block group descriptor */
2441 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2442 return ret;
2443 }
2444 }
2445
2446 return ext4_chunk_trans_blocks(inode, nrblocks);
2447}
2448
2449/*
2450 * How many index/leaf blocks need to change/allocate to add @extents extents?
2451 *
2452 * If we add a single extent, then in the worse case, each tree level
2453 * index/leaf need to be changed in case of the tree split.
2454 *
2455 * If more extents are inserted, they could cause the whole tree split more
2456 * than once, but this is really rare.
2457 */
2458int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2459{
2460 int index;
2461 int depth;
2462
2463 /* If we are converting the inline data, only one is needed here. */
2464 if (ext4_has_inline_data(inode))
2465 return 1;
2466
2467 depth = ext_depth(inode);
2468
2469 if (extents <= 1)
2470 index = depth * 2;
2471 else
2472 index = depth * 3;
2473
2474 return index;
2475}
2476
2477static inline int get_default_free_blocks_flags(struct inode *inode)
2478{
2479 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) ||
2480 ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE))
2481 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2482 else if (ext4_should_journal_data(inode))
2483 return EXT4_FREE_BLOCKS_FORGET;
2484 return 0;
2485}
2486
2487static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2488 struct ext4_extent *ex,
2489 long long *partial_cluster,
2490 ext4_lblk_t from, ext4_lblk_t to)
2491{
2492 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2493 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2494 ext4_fsblk_t pblk;
2495 int flags = get_default_free_blocks_flags(inode);
2496
2497 /*
2498 * For bigalloc file systems, we never free a partial cluster
2499 * at the beginning of the extent. Instead, we make a note
2500 * that we tried freeing the cluster, and check to see if we
2501 * need to free it on a subsequent call to ext4_remove_blocks,
2502 * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
2503 */
2504 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2505
2506 trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2507 /*
2508 * If we have a partial cluster, and it's different from the
2509 * cluster of the last block, we need to explicitly free the
2510 * partial cluster here.
2511 */
2512 pblk = ext4_ext_pblock(ex) + ee_len - 1;
2513 if (*partial_cluster > 0 &&
2514 *partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2515 ext4_free_blocks(handle, inode, NULL,
2516 EXT4_C2B(sbi, *partial_cluster),
2517 sbi->s_cluster_ratio, flags);
2518 *partial_cluster = 0;
2519 }
2520
2521#ifdef EXTENTS_STATS
2522 {
2523 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2524 spin_lock(&sbi->s_ext_stats_lock);
2525 sbi->s_ext_blocks += ee_len;
2526 sbi->s_ext_extents++;
2527 if (ee_len < sbi->s_ext_min)
2528 sbi->s_ext_min = ee_len;
2529 if (ee_len > sbi->s_ext_max)
2530 sbi->s_ext_max = ee_len;
2531 if (ext_depth(inode) > sbi->s_depth_max)
2532 sbi->s_depth_max = ext_depth(inode);
2533 spin_unlock(&sbi->s_ext_stats_lock);
2534 }
2535#endif
2536 if (from >= le32_to_cpu(ex->ee_block)
2537 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2538 /* tail removal */
2539 ext4_lblk_t num;
2540 long long first_cluster;
2541
2542 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2543 pblk = ext4_ext_pblock(ex) + ee_len - num;
2544 /*
2545 * Usually we want to free partial cluster at the end of the
2546 * extent, except for the situation when the cluster is still
2547 * used by any other extent (partial_cluster is negative).
2548 */
2549 if (*partial_cluster < 0 &&
2550 *partial_cluster == -(long long) EXT4_B2C(sbi, pblk+num-1))
2551 flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2552
2553 ext_debug("free last %u blocks starting %llu partial %lld\n",
2554 num, pblk, *partial_cluster);
2555 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2556 /*
2557 * If the block range to be freed didn't start at the
2558 * beginning of a cluster, and we removed the entire
2559 * extent and the cluster is not used by any other extent,
2560 * save the partial cluster here, since we might need to
2561 * delete if we determine that the truncate or punch hole
2562 * operation has removed all of the blocks in the cluster.
2563 * If that cluster is used by another extent, preserve its
2564 * negative value so it isn't freed later on.
2565 *
2566 * If the whole extent wasn't freed, we've reached the
2567 * start of the truncated/punched region and have finished
2568 * removing blocks. If there's a partial cluster here it's
2569 * shared with the remainder of the extent and is no longer
2570 * a candidate for removal.
2571 */
2572 if (EXT4_PBLK_COFF(sbi, pblk) && ee_len == num) {
2573 first_cluster = (long long) EXT4_B2C(sbi, pblk);
2574 if (first_cluster != -*partial_cluster)
2575 *partial_cluster = first_cluster;
2576 } else {
2577 *partial_cluster = 0;
2578 }
2579 } else
2580 ext4_error(sbi->s_sb, "strange request: removal(2) "
2581 "%u-%u from %u:%u",
2582 from, to, le32_to_cpu(ex->ee_block), ee_len);
2583 return 0;
2584}
2585
2586
2587/*
2588 * ext4_ext_rm_leaf() Removes the extents associated with the
2589 * blocks appearing between "start" and "end". Both "start"
2590 * and "end" must appear in the same extent or EIO is returned.
2591 *
2592 * @handle: The journal handle
2593 * @inode: The files inode
2594 * @path: The path to the leaf
2595 * @partial_cluster: The cluster which we'll have to free if all extents
2596 * has been released from it. However, if this value is
2597 * negative, it's a cluster just to the right of the
2598 * punched region and it must not be freed.
2599 * @start: The first block to remove
2600 * @end: The last block to remove
2601 */
2602static int
2603ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2604 struct ext4_ext_path *path,
2605 long long *partial_cluster,
2606 ext4_lblk_t start, ext4_lblk_t end)
2607{
2608 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2609 int err = 0, correct_index = 0;
2610 int depth = ext_depth(inode), credits;
2611 struct ext4_extent_header *eh;
2612 ext4_lblk_t a, b;
2613 unsigned num;
2614 ext4_lblk_t ex_ee_block;
2615 unsigned short ex_ee_len;
2616 unsigned unwritten = 0;
2617 struct ext4_extent *ex;
2618 ext4_fsblk_t pblk;
2619
2620 /* the header must be checked already in ext4_ext_remove_space() */
2621 ext_debug("truncate since %u in leaf to %u\n", start, end);
2622 if (!path[depth].p_hdr)
2623 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2624 eh = path[depth].p_hdr;
2625 if (unlikely(path[depth].p_hdr == NULL)) {
2626 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2627 return -EFSCORRUPTED;
2628 }
2629 /* find where to start removing */
2630 ex = path[depth].p_ext;
2631 if (!ex)
2632 ex = EXT_LAST_EXTENT(eh);
2633
2634 ex_ee_block = le32_to_cpu(ex->ee_block);
2635 ex_ee_len = ext4_ext_get_actual_len(ex);
2636
2637 trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2638
2639 while (ex >= EXT_FIRST_EXTENT(eh) &&
2640 ex_ee_block + ex_ee_len > start) {
2641
2642 if (ext4_ext_is_unwritten(ex))
2643 unwritten = 1;
2644 else
2645 unwritten = 0;
2646
2647 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2648 unwritten, ex_ee_len);
2649 path[depth].p_ext = ex;
2650
2651 a = ex_ee_block > start ? ex_ee_block : start;
2652 b = ex_ee_block+ex_ee_len - 1 < end ?
2653 ex_ee_block+ex_ee_len - 1 : end;
2654
2655 ext_debug(" border %u:%u\n", a, b);
2656
2657 /* If this extent is beyond the end of the hole, skip it */
2658 if (end < ex_ee_block) {
2659 /*
2660 * We're going to skip this extent and move to another,
2661 * so note that its first cluster is in use to avoid
2662 * freeing it when removing blocks. Eventually, the
2663 * right edge of the truncated/punched region will
2664 * be just to the left.
2665 */
2666 if (sbi->s_cluster_ratio > 1) {
2667 pblk = ext4_ext_pblock(ex);
2668 *partial_cluster =
2669 -(long long) EXT4_B2C(sbi, pblk);
2670 }
2671 ex--;
2672 ex_ee_block = le32_to_cpu(ex->ee_block);
2673 ex_ee_len = ext4_ext_get_actual_len(ex);
2674 continue;
2675 } else if (b != ex_ee_block + ex_ee_len - 1) {
2676 EXT4_ERROR_INODE(inode,
2677 "can not handle truncate %u:%u "
2678 "on extent %u:%u",
2679 start, end, ex_ee_block,
2680 ex_ee_block + ex_ee_len - 1);
2681 err = -EFSCORRUPTED;
2682 goto out;
2683 } else if (a != ex_ee_block) {
2684 /* remove tail of the extent */
2685 num = a - ex_ee_block;
2686 } else {
2687 /* remove whole extent: excellent! */
2688 num = 0;
2689 }
2690 /*
2691 * 3 for leaf, sb, and inode plus 2 (bmap and group
2692 * descriptor) for each block group; assume two block
2693 * groups plus ex_ee_len/blocks_per_block_group for
2694 * the worst case
2695 */
2696 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2697 if (ex == EXT_FIRST_EXTENT(eh)) {
2698 correct_index = 1;
2699 credits += (ext_depth(inode)) + 1;
2700 }
2701 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2702
2703 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2704 if (err)
2705 goto out;
2706
2707 err = ext4_ext_get_access(handle, inode, path + depth);
2708 if (err)
2709 goto out;
2710
2711 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2712 a, b);
2713 if (err)
2714 goto out;
2715
2716 if (num == 0)
2717 /* this extent is removed; mark slot entirely unused */
2718 ext4_ext_store_pblock(ex, 0);
2719
2720 ex->ee_len = cpu_to_le16(num);
2721 /*
2722 * Do not mark unwritten if all the blocks in the
2723 * extent have been removed.
2724 */
2725 if (unwritten && num)
2726 ext4_ext_mark_unwritten(ex);
2727 /*
2728 * If the extent was completely released,
2729 * we need to remove it from the leaf
2730 */
2731 if (num == 0) {
2732 if (end != EXT_MAX_BLOCKS - 1) {
2733 /*
2734 * For hole punching, we need to scoot all the
2735 * extents up when an extent is removed so that
2736 * we dont have blank extents in the middle
2737 */
2738 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2739 sizeof(struct ext4_extent));
2740
2741 /* Now get rid of the one at the end */
2742 memset(EXT_LAST_EXTENT(eh), 0,
2743 sizeof(struct ext4_extent));
2744 }
2745 le16_add_cpu(&eh->eh_entries, -1);
2746 }
2747
2748 err = ext4_ext_dirty(handle, inode, path + depth);
2749 if (err)
2750 goto out;
2751
2752 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2753 ext4_ext_pblock(ex));
2754 ex--;
2755 ex_ee_block = le32_to_cpu(ex->ee_block);
2756 ex_ee_len = ext4_ext_get_actual_len(ex);
2757 }
2758
2759 if (correct_index && eh->eh_entries)
2760 err = ext4_ext_correct_indexes(handle, inode, path);
2761
2762 /*
2763 * If there's a partial cluster and at least one extent remains in
2764 * the leaf, free the partial cluster if it isn't shared with the
2765 * current extent. If it is shared with the current extent
2766 * we zero partial_cluster because we've reached the start of the
2767 * truncated/punched region and we're done removing blocks.
2768 */
2769 if (*partial_cluster > 0 && ex >= EXT_FIRST_EXTENT(eh)) {
2770 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
2771 if (*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2772 ext4_free_blocks(handle, inode, NULL,
2773 EXT4_C2B(sbi, *partial_cluster),
2774 sbi->s_cluster_ratio,
2775 get_default_free_blocks_flags(inode));
2776 }
2777 *partial_cluster = 0;
2778 }
2779
2780 /* if this leaf is free, then we should
2781 * remove it from index block above */
2782 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2783 err = ext4_ext_rm_idx(handle, inode, path, depth);
2784
2785out:
2786 return err;
2787}
2788
2789/*
2790 * ext4_ext_more_to_rm:
2791 * returns 1 if current index has to be freed (even partial)
2792 */
2793static int
2794ext4_ext_more_to_rm(struct ext4_ext_path *path)
2795{
2796 BUG_ON(path->p_idx == NULL);
2797
2798 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2799 return 0;
2800
2801 /*
2802 * if truncate on deeper level happened, it wasn't partial,
2803 * so we have to consider current index for truncation
2804 */
2805 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2806 return 0;
2807 return 1;
2808}
2809
2810int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2811 ext4_lblk_t end)
2812{
2813 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2814 int depth = ext_depth(inode);
2815 struct ext4_ext_path *path = NULL;
2816 long long partial_cluster = 0;
2817 handle_t *handle;
2818 int i = 0, err = 0;
2819
2820 ext_debug("truncate since %u to %u\n", start, end);
2821
2822 /* probably first extent we're gonna free will be last in block */
2823 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1);
2824 if (IS_ERR(handle))
2825 return PTR_ERR(handle);
2826
2827again:
2828 trace_ext4_ext_remove_space(inode, start, end, depth);
2829
2830 /*
2831 * Check if we are removing extents inside the extent tree. If that
2832 * is the case, we are going to punch a hole inside the extent tree
2833 * so we have to check whether we need to split the extent covering
2834 * the last block to remove so we can easily remove the part of it
2835 * in ext4_ext_rm_leaf().
2836 */
2837 if (end < EXT_MAX_BLOCKS - 1) {
2838 struct ext4_extent *ex;
2839 ext4_lblk_t ee_block, ex_end, lblk;
2840 ext4_fsblk_t pblk;
2841
2842 /* find extent for or closest extent to this block */
2843 path = ext4_find_extent(inode, end, NULL, EXT4_EX_NOCACHE);
2844 if (IS_ERR(path)) {
2845 ext4_journal_stop(handle);
2846 return PTR_ERR(path);
2847 }
2848 depth = ext_depth(inode);
2849 /* Leaf not may not exist only if inode has no blocks at all */
2850 ex = path[depth].p_ext;
2851 if (!ex) {
2852 if (depth) {
2853 EXT4_ERROR_INODE(inode,
2854 "path[%d].p_hdr == NULL",
2855 depth);
2856 err = -EFSCORRUPTED;
2857 }
2858 goto out;
2859 }
2860
2861 ee_block = le32_to_cpu(ex->ee_block);
2862 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
2863
2864 /*
2865 * See if the last block is inside the extent, if so split
2866 * the extent at 'end' block so we can easily remove the
2867 * tail of the first part of the split extent in
2868 * ext4_ext_rm_leaf().
2869 */
2870 if (end >= ee_block && end < ex_end) {
2871
2872 /*
2873 * If we're going to split the extent, note that
2874 * the cluster containing the block after 'end' is
2875 * in use to avoid freeing it when removing blocks.
2876 */
2877 if (sbi->s_cluster_ratio > 1) {
2878 pblk = ext4_ext_pblock(ex) + end - ee_block + 2;
2879 partial_cluster =
2880 -(long long) EXT4_B2C(sbi, pblk);
2881 }
2882
2883 /*
2884 * Split the extent in two so that 'end' is the last
2885 * block in the first new extent. Also we should not
2886 * fail removing space due to ENOSPC so try to use
2887 * reserved block if that happens.
2888 */
2889 err = ext4_force_split_extent_at(handle, inode, &path,
2890 end + 1, 1);
2891 if (err < 0)
2892 goto out;
2893
2894 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end) {
2895 /*
2896 * If there's an extent to the right its first cluster
2897 * contains the immediate right boundary of the
2898 * truncated/punched region. Set partial_cluster to
2899 * its negative value so it won't be freed if shared
2900 * with the current extent. The end < ee_block case
2901 * is handled in ext4_ext_rm_leaf().
2902 */
2903 lblk = ex_end + 1;
2904 err = ext4_ext_search_right(inode, path, &lblk, &pblk,
2905 &ex);
2906 if (err)
2907 goto out;
2908 if (pblk)
2909 partial_cluster =
2910 -(long long) EXT4_B2C(sbi, pblk);
2911 }
2912 }
2913 /*
2914 * We start scanning from right side, freeing all the blocks
2915 * after i_size and walking into the tree depth-wise.
2916 */
2917 depth = ext_depth(inode);
2918 if (path) {
2919 int k = i = depth;
2920 while (--k > 0)
2921 path[k].p_block =
2922 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2923 } else {
2924 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2925 GFP_NOFS);
2926 if (path == NULL) {
2927 ext4_journal_stop(handle);
2928 return -ENOMEM;
2929 }
2930 path[0].p_maxdepth = path[0].p_depth = depth;
2931 path[0].p_hdr = ext_inode_hdr(inode);
2932 i = 0;
2933
2934 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2935 err = -EFSCORRUPTED;
2936 goto out;
2937 }
2938 }
2939 err = 0;
2940
2941 while (i >= 0 && err == 0) {
2942 if (i == depth) {
2943 /* this is leaf block */
2944 err = ext4_ext_rm_leaf(handle, inode, path,
2945 &partial_cluster, start,
2946 end);
2947 /* root level has p_bh == NULL, brelse() eats this */
2948 brelse(path[i].p_bh);
2949 path[i].p_bh = NULL;
2950 i--;
2951 continue;
2952 }
2953
2954 /* this is index block */
2955 if (!path[i].p_hdr) {
2956 ext_debug("initialize header\n");
2957 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2958 }
2959
2960 if (!path[i].p_idx) {
2961 /* this level hasn't been touched yet */
2962 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2963 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2964 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2965 path[i].p_hdr,
2966 le16_to_cpu(path[i].p_hdr->eh_entries));
2967 } else {
2968 /* we were already here, see at next index */
2969 path[i].p_idx--;
2970 }
2971
2972 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2973 i, EXT_FIRST_INDEX(path[i].p_hdr),
2974 path[i].p_idx);
2975 if (ext4_ext_more_to_rm(path + i)) {
2976 struct buffer_head *bh;
2977 /* go to the next level */
2978 ext_debug("move to level %d (block %llu)\n",
2979 i + 1, ext4_idx_pblock(path[i].p_idx));
2980 memset(path + i + 1, 0, sizeof(*path));
2981 bh = read_extent_tree_block(inode,
2982 ext4_idx_pblock(path[i].p_idx), depth - i - 1,
2983 EXT4_EX_NOCACHE);
2984 if (IS_ERR(bh)) {
2985 /* should we reset i_size? */
2986 err = PTR_ERR(bh);
2987 break;
2988 }
2989 /* Yield here to deal with large extent trees.
2990 * Should be a no-op if we did IO above. */
2991 cond_resched();
2992 if (WARN_ON(i + 1 > depth)) {
2993 err = -EFSCORRUPTED;
2994 break;
2995 }
2996 path[i + 1].p_bh = bh;
2997
2998 /* save actual number of indexes since this
2999 * number is changed at the next iteration */
3000 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
3001 i++;
3002 } else {
3003 /* we finished processing this index, go up */
3004 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
3005 /* index is empty, remove it;
3006 * handle must be already prepared by the
3007 * truncatei_leaf() */
3008 err = ext4_ext_rm_idx(handle, inode, path, i);
3009 }
3010 /* root level has p_bh == NULL, brelse() eats this */
3011 brelse(path[i].p_bh);
3012 path[i].p_bh = NULL;
3013 i--;
3014 ext_debug("return to level %d\n", i);
3015 }
3016 }
3017
3018 trace_ext4_ext_remove_space_done(inode, start, end, depth,
3019 partial_cluster, path->p_hdr->eh_entries);
3020
3021 /*
3022 * If we still have something in the partial cluster and we have removed
3023 * even the first extent, then we should free the blocks in the partial
3024 * cluster as well. (This code will only run when there are no leaves
3025 * to the immediate left of the truncated/punched region.)
3026 */
3027 if (partial_cluster > 0 && err == 0) {
3028 /* don't zero partial_cluster since it's not used afterwards */
3029 ext4_free_blocks(handle, inode, NULL,
3030 EXT4_C2B(sbi, partial_cluster),
3031 sbi->s_cluster_ratio,
3032 get_default_free_blocks_flags(inode));
3033 }
3034
3035 /* TODO: flexible tree reduction should be here */
3036 if (path->p_hdr->eh_entries == 0) {
3037 /*
3038 * truncate to zero freed all the tree,
3039 * so we need to correct eh_depth
3040 */
3041 err = ext4_ext_get_access(handle, inode, path);
3042 if (err == 0) {
3043 ext_inode_hdr(inode)->eh_depth = 0;
3044 ext_inode_hdr(inode)->eh_max =
3045 cpu_to_le16(ext4_ext_space_root(inode, 0));
3046 err = ext4_ext_dirty(handle, inode, path);
3047 }
3048 }
3049out:
3050 ext4_ext_drop_refs(path);
3051 kfree(path);
3052 path = NULL;
3053 if (err == -EAGAIN)
3054 goto again;
3055 ext4_journal_stop(handle);
3056
3057 return err;
3058}
3059
3060/*
3061 * called at mount time
3062 */
3063void ext4_ext_init(struct super_block *sb)
3064{
3065 /*
3066 * possible initialization would be here
3067 */
3068
3069 if (ext4_has_feature_extents(sb)) {
3070#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
3071 printk(KERN_INFO "EXT4-fs: file extents enabled"
3072#ifdef AGGRESSIVE_TEST
3073 ", aggressive tests"
3074#endif
3075#ifdef CHECK_BINSEARCH
3076 ", check binsearch"
3077#endif
3078#ifdef EXTENTS_STATS
3079 ", stats"
3080#endif
3081 "\n");
3082#endif
3083#ifdef EXTENTS_STATS
3084 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3085 EXT4_SB(sb)->s_ext_min = 1 << 30;
3086 EXT4_SB(sb)->s_ext_max = 0;
3087#endif
3088 }
3089}
3090
3091/*
3092 * called at umount time
3093 */
3094void ext4_ext_release(struct super_block *sb)
3095{
3096 if (!ext4_has_feature_extents(sb))
3097 return;
3098
3099#ifdef EXTENTS_STATS
3100 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3101 struct ext4_sb_info *sbi = EXT4_SB(sb);
3102 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3103 sbi->s_ext_blocks, sbi->s_ext_extents,
3104 sbi->s_ext_blocks / sbi->s_ext_extents);
3105 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3106 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3107 }
3108#endif
3109}
3110
3111static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3112{
3113 ext4_lblk_t ee_block;
3114 ext4_fsblk_t ee_pblock;
3115 unsigned int ee_len;
3116
3117 ee_block = le32_to_cpu(ex->ee_block);
3118 ee_len = ext4_ext_get_actual_len(ex);
3119 ee_pblock = ext4_ext_pblock(ex);
3120
3121 if (ee_len == 0)
3122 return 0;
3123
3124 return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3125 EXTENT_STATUS_WRITTEN);
3126}
3127
3128/* FIXME!! we need to try to merge to left or right after zero-out */
3129static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3130{
3131 ext4_fsblk_t ee_pblock;
3132 unsigned int ee_len;
3133
3134 ee_len = ext4_ext_get_actual_len(ex);
3135 ee_pblock = ext4_ext_pblock(ex);
3136 return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock,
3137 ee_len);
3138}
3139
3140/*
3141 * ext4_split_extent_at() splits an extent at given block.
3142 *
3143 * @handle: the journal handle
3144 * @inode: the file inode
3145 * @path: the path to the extent
3146 * @split: the logical block where the extent is splitted.
3147 * @split_flags: indicates if the extent could be zeroout if split fails, and
3148 * the states(init or unwritten) of new extents.
3149 * @flags: flags used to insert new extent to extent tree.
3150 *
3151 *
3152 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3153 * of which are deterimined by split_flag.
3154 *
3155 * There are two cases:
3156 * a> the extent are splitted into two extent.
3157 * b> split is not needed, and just mark the extent.
3158 *
3159 * return 0 on success.
3160 */
3161static int ext4_split_extent_at(handle_t *handle,
3162 struct inode *inode,
3163 struct ext4_ext_path **ppath,
3164 ext4_lblk_t split,
3165 int split_flag,
3166 int flags)
3167{
3168 struct ext4_ext_path *path = *ppath;
3169 ext4_fsblk_t newblock;
3170 ext4_lblk_t ee_block;
3171 struct ext4_extent *ex, newex, orig_ex, zero_ex;
3172 struct ext4_extent *ex2 = NULL;
3173 unsigned int ee_len, depth;
3174 int err = 0;
3175
3176 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3177 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3178
3179 ext_debug("ext4_split_extents_at: inode %lu, logical"
3180 "block %llu\n", inode->i_ino, (unsigned long long)split);
3181
3182 ext4_ext_show_leaf(inode, path);
3183
3184 depth = ext_depth(inode);
3185 ex = path[depth].p_ext;
3186 ee_block = le32_to_cpu(ex->ee_block);
3187 ee_len = ext4_ext_get_actual_len(ex);
3188 newblock = split - ee_block + ext4_ext_pblock(ex);
3189
3190 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3191 BUG_ON(!ext4_ext_is_unwritten(ex) &&
3192 split_flag & (EXT4_EXT_MAY_ZEROOUT |
3193 EXT4_EXT_MARK_UNWRIT1 |
3194 EXT4_EXT_MARK_UNWRIT2));
3195
3196 err = ext4_ext_get_access(handle, inode, path + depth);
3197 if (err)
3198 goto out;
3199
3200 if (split == ee_block) {
3201 /*
3202 * case b: block @split is the block that the extent begins with
3203 * then we just change the state of the extent, and splitting
3204 * is not needed.
3205 */
3206 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3207 ext4_ext_mark_unwritten(ex);
3208 else
3209 ext4_ext_mark_initialized(ex);
3210
3211 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3212 ext4_ext_try_to_merge(handle, inode, path, ex);
3213
3214 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3215 goto out;
3216 }
3217
3218 /* case a */
3219 memcpy(&orig_ex, ex, sizeof(orig_ex));
3220 ex->ee_len = cpu_to_le16(split - ee_block);
3221 if (split_flag & EXT4_EXT_MARK_UNWRIT1)
3222 ext4_ext_mark_unwritten(ex);
3223
3224 /*
3225 * path may lead to new leaf, not to original leaf any more
3226 * after ext4_ext_insert_extent() returns,
3227 */
3228 err = ext4_ext_dirty(handle, inode, path + depth);
3229 if (err)
3230 goto fix_extent_len;
3231
3232 ex2 = &newex;
3233 ex2->ee_block = cpu_to_le32(split);
3234 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
3235 ext4_ext_store_pblock(ex2, newblock);
3236 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3237 ext4_ext_mark_unwritten(ex2);
3238
3239 err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
3240 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3241 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3242 if (split_flag & EXT4_EXT_DATA_VALID1) {
3243 err = ext4_ext_zeroout(inode, ex2);
3244 zero_ex.ee_block = ex2->ee_block;
3245 zero_ex.ee_len = cpu_to_le16(
3246 ext4_ext_get_actual_len(ex2));
3247 ext4_ext_store_pblock(&zero_ex,
3248 ext4_ext_pblock(ex2));
3249 } else {
3250 err = ext4_ext_zeroout(inode, ex);
3251 zero_ex.ee_block = ex->ee_block;
3252 zero_ex.ee_len = cpu_to_le16(
3253 ext4_ext_get_actual_len(ex));
3254 ext4_ext_store_pblock(&zero_ex,
3255 ext4_ext_pblock(ex));
3256 }
3257 } else {
3258 err = ext4_ext_zeroout(inode, &orig_ex);
3259 zero_ex.ee_block = orig_ex.ee_block;
3260 zero_ex.ee_len = cpu_to_le16(
3261 ext4_ext_get_actual_len(&orig_ex));
3262 ext4_ext_store_pblock(&zero_ex,
3263 ext4_ext_pblock(&orig_ex));
3264 }
3265
3266 if (err)
3267 goto fix_extent_len;
3268 /* update the extent length and mark as initialized */
3269 ex->ee_len = cpu_to_le16(ee_len);
3270 ext4_ext_try_to_merge(handle, inode, path, ex);
3271 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3272 if (err)
3273 goto fix_extent_len;
3274
3275 /* update extent status tree */
3276 err = ext4_zeroout_es(inode, &zero_ex);
3277
3278 goto out;
3279 } else if (err)
3280 goto fix_extent_len;
3281
3282out:
3283 ext4_ext_show_leaf(inode, path);
3284 return err;
3285
3286fix_extent_len:
3287 ex->ee_len = orig_ex.ee_len;
3288 ext4_ext_dirty(handle, inode, path + path->p_depth);
3289 return err;
3290}
3291
3292/*
3293 * ext4_split_extents() splits an extent and mark extent which is covered
3294 * by @map as split_flags indicates
3295 *
3296 * It may result in splitting the extent into multiple extents (up to three)
3297 * There are three possibilities:
3298 * a> There is no split required
3299 * b> Splits in two extents: Split is happening at either end of the extent
3300 * c> Splits in three extents: Somone is splitting in middle of the extent
3301 *
3302 */
3303static int ext4_split_extent(handle_t *handle,
3304 struct inode *inode,
3305 struct ext4_ext_path **ppath,
3306 struct ext4_map_blocks *map,
3307 int split_flag,
3308 int flags)
3309{
3310 struct ext4_ext_path *path = *ppath;
3311 ext4_lblk_t ee_block;
3312 struct ext4_extent *ex;
3313 unsigned int ee_len, depth;
3314 int err = 0;
3315 int unwritten;
3316 int split_flag1, flags1;
3317 int allocated = map->m_len;
3318
3319 depth = ext_depth(inode);
3320 ex = path[depth].p_ext;
3321 ee_block = le32_to_cpu(ex->ee_block);
3322 ee_len = ext4_ext_get_actual_len(ex);
3323 unwritten = ext4_ext_is_unwritten(ex);
3324
3325 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3326 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3327 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3328 if (unwritten)
3329 split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
3330 EXT4_EXT_MARK_UNWRIT2;
3331 if (split_flag & EXT4_EXT_DATA_VALID2)
3332 split_flag1 |= EXT4_EXT_DATA_VALID1;
3333 err = ext4_split_extent_at(handle, inode, ppath,
3334 map->m_lblk + map->m_len, split_flag1, flags1);
3335 if (err)
3336 goto out;
3337 } else {
3338 allocated = ee_len - (map->m_lblk - ee_block);
3339 }
3340 /*
3341 * Update path is required because previous ext4_split_extent_at() may
3342 * result in split of original leaf or extent zeroout.
3343 */
3344 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3345 if (IS_ERR(path))
3346 return PTR_ERR(path);
3347 depth = ext_depth(inode);
3348 ex = path[depth].p_ext;
3349 if (!ex) {
3350 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3351 (unsigned long) map->m_lblk);
3352 return -EFSCORRUPTED;
3353 }
3354 unwritten = ext4_ext_is_unwritten(ex);
3355 split_flag1 = 0;
3356
3357 if (map->m_lblk >= ee_block) {
3358 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3359 if (unwritten) {
3360 split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
3361 split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3362 EXT4_EXT_MARK_UNWRIT2);
3363 }
3364 err = ext4_split_extent_at(handle, inode, ppath,
3365 map->m_lblk, split_flag1, flags);
3366 if (err)
3367 goto out;
3368 }
3369
3370 ext4_ext_show_leaf(inode, path);
3371out:
3372 return err ? err : allocated;
3373}
3374
3375/*
3376 * This function is called by ext4_ext_map_blocks() if someone tries to write
3377 * to an unwritten extent. It may result in splitting the unwritten
3378 * extent into multiple extents (up to three - one initialized and two
3379 * unwritten).
3380 * There are three possibilities:
3381 * a> There is no split required: Entire extent should be initialized
3382 * b> Splits in two extents: Write is happening at either end of the extent
3383 * c> Splits in three extents: Somone is writing in middle of the extent
3384 *
3385 * Pre-conditions:
3386 * - The extent pointed to by 'path' is unwritten.
3387 * - The extent pointed to by 'path' contains a superset
3388 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3389 *
3390 * Post-conditions on success:
3391 * - the returned value is the number of blocks beyond map->l_lblk
3392 * that are allocated and initialized.
3393 * It is guaranteed to be >= map->m_len.
3394 */
3395static int ext4_ext_convert_to_initialized(handle_t *handle,
3396 struct inode *inode,
3397 struct ext4_map_blocks *map,
3398 struct ext4_ext_path **ppath,
3399 int flags)
3400{
3401 struct ext4_ext_path *path = *ppath;
3402 struct ext4_sb_info *sbi;
3403 struct ext4_extent_header *eh;
3404 struct ext4_map_blocks split_map;
3405 struct ext4_extent zero_ex1, zero_ex2;
3406 struct ext4_extent *ex, *abut_ex;
3407 ext4_lblk_t ee_block, eof_block;
3408 unsigned int ee_len, depth, map_len = map->m_len;
3409 int allocated = 0, max_zeroout = 0;
3410 int err = 0;
3411 int split_flag = EXT4_EXT_DATA_VALID2;
3412
3413 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3414 "block %llu, max_blocks %u\n", inode->i_ino,
3415 (unsigned long long)map->m_lblk, map_len);
3416
3417 sbi = EXT4_SB(inode->i_sb);
3418 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3419 inode->i_sb->s_blocksize_bits;
3420 if (eof_block < map->m_lblk + map_len)
3421 eof_block = map->m_lblk + map_len;
3422
3423 depth = ext_depth(inode);
3424 eh = path[depth].p_hdr;
3425 ex = path[depth].p_ext;
3426 ee_block = le32_to_cpu(ex->ee_block);
3427 ee_len = ext4_ext_get_actual_len(ex);
3428 zero_ex1.ee_len = 0;
3429 zero_ex2.ee_len = 0;
3430
3431 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3432
3433 /* Pre-conditions */
3434 BUG_ON(!ext4_ext_is_unwritten(ex));
3435 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3436
3437 /*
3438 * Attempt to transfer newly initialized blocks from the currently
3439 * unwritten extent to its neighbor. This is much cheaper
3440 * than an insertion followed by a merge as those involve costly
3441 * memmove() calls. Transferring to the left is the common case in
3442 * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3443 * followed by append writes.
3444 *
3445 * Limitations of the current logic:
3446 * - L1: we do not deal with writes covering the whole extent.
3447 * This would require removing the extent if the transfer
3448 * is possible.
3449 * - L2: we only attempt to merge with an extent stored in the
3450 * same extent tree node.
3451 */
3452 if ((map->m_lblk == ee_block) &&
3453 /* See if we can merge left */
3454 (map_len < ee_len) && /*L1*/
3455 (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/
3456 ext4_lblk_t prev_lblk;
3457 ext4_fsblk_t prev_pblk, ee_pblk;
3458 unsigned int prev_len;
3459
3460 abut_ex = ex - 1;
3461 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3462 prev_len = ext4_ext_get_actual_len(abut_ex);
3463 prev_pblk = ext4_ext_pblock(abut_ex);
3464 ee_pblk = ext4_ext_pblock(ex);
3465
3466 /*
3467 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3468 * upon those conditions:
3469 * - C1: abut_ex is initialized,
3470 * - C2: abut_ex is logically abutting ex,
3471 * - C3: abut_ex is physically abutting ex,
3472 * - C4: abut_ex can receive the additional blocks without
3473 * overflowing the (initialized) length limit.
3474 */
3475 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3476 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3477 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3478 (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3479 err = ext4_ext_get_access(handle, inode, path + depth);
3480 if (err)
3481 goto out;
3482
3483 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3484 map, ex, abut_ex);
3485
3486 /* Shift the start of ex by 'map_len' blocks */
3487 ex->ee_block = cpu_to_le32(ee_block + map_len);
3488 ext4_ext_store_pblock(ex, ee_pblk + map_len);
3489 ex->ee_len = cpu_to_le16(ee_len - map_len);
3490 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3491
3492 /* Extend abut_ex by 'map_len' blocks */
3493 abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3494
3495 /* Result: number of initialized blocks past m_lblk */
3496 allocated = map_len;
3497 }
3498 } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3499 (map_len < ee_len) && /*L1*/
3500 ex < EXT_LAST_EXTENT(eh)) { /*L2*/
3501 /* See if we can merge right */
3502 ext4_lblk_t next_lblk;
3503 ext4_fsblk_t next_pblk, ee_pblk;
3504 unsigned int next_len;
3505
3506 abut_ex = ex + 1;
3507 next_lblk = le32_to_cpu(abut_ex->ee_block);
3508 next_len = ext4_ext_get_actual_len(abut_ex);
3509 next_pblk = ext4_ext_pblock(abut_ex);
3510 ee_pblk = ext4_ext_pblock(ex);
3511
3512 /*
3513 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3514 * upon those conditions:
3515 * - C1: abut_ex is initialized,
3516 * - C2: abut_ex is logically abutting ex,
3517 * - C3: abut_ex is physically abutting ex,
3518 * - C4: abut_ex can receive the additional blocks without
3519 * overflowing the (initialized) length limit.
3520 */
3521 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3522 ((map->m_lblk + map_len) == next_lblk) && /*C2*/
3523 ((ee_pblk + ee_len) == next_pblk) && /*C3*/
3524 (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3525 err = ext4_ext_get_access(handle, inode, path + depth);
3526 if (err)
3527 goto out;
3528
3529 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3530 map, ex, abut_ex);
3531
3532 /* Shift the start of abut_ex by 'map_len' blocks */
3533 abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3534 ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3535 ex->ee_len = cpu_to_le16(ee_len - map_len);
3536 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3537
3538 /* Extend abut_ex by 'map_len' blocks */
3539 abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3540
3541 /* Result: number of initialized blocks past m_lblk */
3542 allocated = map_len;
3543 }
3544 }
3545 if (allocated) {
3546 /* Mark the block containing both extents as dirty */
3547 ext4_ext_dirty(handle, inode, path + depth);
3548
3549 /* Update path to point to the right extent */
3550 path[depth].p_ext = abut_ex;
3551 goto out;
3552 } else
3553 allocated = ee_len - (map->m_lblk - ee_block);
3554
3555 WARN_ON(map->m_lblk < ee_block);
3556 /*
3557 * It is safe to convert extent to initialized via explicit
3558 * zeroout only if extent is fully inside i_size or new_size.
3559 */
3560 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3561
3562 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3563 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3564 (inode->i_sb->s_blocksize_bits - 10);
3565
3566 if (ext4_encrypted_inode(inode))
3567 max_zeroout = 0;
3568
3569 /*
3570 * five cases:
3571 * 1. split the extent into three extents.
3572 * 2. split the extent into two extents, zeroout the head of the first
3573 * extent.
3574 * 3. split the extent into two extents, zeroout the tail of the second
3575 * extent.
3576 * 4. split the extent into two extents with out zeroout.
3577 * 5. no splitting needed, just possibly zeroout the head and / or the
3578 * tail of the extent.
3579 */
3580 split_map.m_lblk = map->m_lblk;
3581 split_map.m_len = map->m_len;
3582
3583 if (max_zeroout && (allocated > split_map.m_len)) {
3584 if (allocated <= max_zeroout) {
3585 /* case 3 or 5 */
3586 zero_ex1.ee_block =
3587 cpu_to_le32(split_map.m_lblk +
3588 split_map.m_len);
3589 zero_ex1.ee_len =
3590 cpu_to_le16(allocated - split_map.m_len);
3591 ext4_ext_store_pblock(&zero_ex1,
3592 ext4_ext_pblock(ex) + split_map.m_lblk +
3593 split_map.m_len - ee_block);
3594 err = ext4_ext_zeroout(inode, &zero_ex1);
3595 if (err)
3596 goto out;
3597 split_map.m_len = allocated;
3598 }
3599 if (split_map.m_lblk - ee_block + split_map.m_len <
3600 max_zeroout) {
3601 /* case 2 or 5 */
3602 if (split_map.m_lblk != ee_block) {
3603 zero_ex2.ee_block = ex->ee_block;
3604 zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk -
3605 ee_block);
3606 ext4_ext_store_pblock(&zero_ex2,
3607 ext4_ext_pblock(ex));
3608 err = ext4_ext_zeroout(inode, &zero_ex2);
3609 if (err)
3610 goto out;
3611 }
3612
3613 split_map.m_len += split_map.m_lblk - ee_block;
3614 split_map.m_lblk = ee_block;
3615 allocated = map->m_len;
3616 }
3617 }
3618
3619 err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
3620 flags);
3621 if (err > 0)
3622 err = 0;
3623out:
3624 /* If we have gotten a failure, don't zero out status tree */
3625 if (!err) {
3626 err = ext4_zeroout_es(inode, &zero_ex1);
3627 if (!err)
3628 err = ext4_zeroout_es(inode, &zero_ex2);
3629 }
3630 return err ? err : allocated;
3631}
3632
3633/*
3634 * This function is called by ext4_ext_map_blocks() from
3635 * ext4_get_blocks_dio_write() when DIO to write
3636 * to an unwritten extent.
3637 *
3638 * Writing to an unwritten extent may result in splitting the unwritten
3639 * extent into multiple initialized/unwritten extents (up to three)
3640 * There are three possibilities:
3641 * a> There is no split required: Entire extent should be unwritten
3642 * b> Splits in two extents: Write is happening at either end of the extent
3643 * c> Splits in three extents: Somone is writing in middle of the extent
3644 *
3645 * This works the same way in the case of initialized -> unwritten conversion.
3646 *
3647 * One of more index blocks maybe needed if the extent tree grow after
3648 * the unwritten extent split. To prevent ENOSPC occur at the IO
3649 * complete, we need to split the unwritten extent before DIO submit
3650 * the IO. The unwritten extent called at this time will be split
3651 * into three unwritten extent(at most). After IO complete, the part
3652 * being filled will be convert to initialized by the end_io callback function
3653 * via ext4_convert_unwritten_extents().
3654 *
3655 * Returns the size of unwritten extent to be written on success.
3656 */
3657static int ext4_split_convert_extents(handle_t *handle,
3658 struct inode *inode,
3659 struct ext4_map_blocks *map,
3660 struct ext4_ext_path **ppath,
3661 int flags)
3662{
3663 struct ext4_ext_path *path = *ppath;
3664 ext4_lblk_t eof_block;
3665 ext4_lblk_t ee_block;
3666 struct ext4_extent *ex;
3667 unsigned int ee_len;
3668 int split_flag = 0, depth;
3669
3670 ext_debug("%s: inode %lu, logical block %llu, max_blocks %u\n",
3671 __func__, inode->i_ino,
3672 (unsigned long long)map->m_lblk, map->m_len);
3673
3674 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3675 inode->i_sb->s_blocksize_bits;
3676 if (eof_block < map->m_lblk + map->m_len)
3677 eof_block = map->m_lblk + map->m_len;
3678 /*
3679 * It is safe to convert extent to initialized via explicit
3680 * zeroout only if extent is fully insde i_size or new_size.
3681 */
3682 depth = ext_depth(inode);
3683 ex = path[depth].p_ext;
3684 ee_block = le32_to_cpu(ex->ee_block);
3685 ee_len = ext4_ext_get_actual_len(ex);
3686
3687 /* Convert to unwritten */
3688 if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
3689 split_flag |= EXT4_EXT_DATA_VALID1;
3690 /* Convert to initialized */
3691 } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
3692 split_flag |= ee_block + ee_len <= eof_block ?
3693 EXT4_EXT_MAY_ZEROOUT : 0;
3694 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
3695 }
3696 flags |= EXT4_GET_BLOCKS_PRE_IO;
3697 return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
3698}
3699
3700static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3701 struct inode *inode,
3702 struct ext4_map_blocks *map,
3703 struct ext4_ext_path **ppath)
3704{
3705 struct ext4_ext_path *path = *ppath;
3706 struct ext4_extent *ex;
3707 ext4_lblk_t ee_block;
3708 unsigned int ee_len;
3709 int depth;
3710 int err = 0;
3711
3712 depth = ext_depth(inode);
3713 ex = path[depth].p_ext;
3714 ee_block = le32_to_cpu(ex->ee_block);
3715 ee_len = ext4_ext_get_actual_len(ex);
3716
3717 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3718 "block %llu, max_blocks %u\n", inode->i_ino,
3719 (unsigned long long)ee_block, ee_len);
3720
3721 /* If extent is larger than requested it is a clear sign that we still
3722 * have some extent state machine issues left. So extent_split is still
3723 * required.
3724 * TODO: Once all related issues will be fixed this situation should be
3725 * illegal.
3726 */
3727 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3728#ifdef EXT4_DEBUG
3729 ext4_warning("Inode (%ld) finished: extent logical block %llu,"
3730 " len %u; IO logical block %llu, len %u",
3731 inode->i_ino, (unsigned long long)ee_block, ee_len,
3732 (unsigned long long)map->m_lblk, map->m_len);
3733#endif
3734 err = ext4_split_convert_extents(handle, inode, map, ppath,
3735 EXT4_GET_BLOCKS_CONVERT);
3736 if (err < 0)
3737 return err;
3738 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3739 if (IS_ERR(path))
3740 return PTR_ERR(path);
3741 depth = ext_depth(inode);
3742 ex = path[depth].p_ext;
3743 }
3744
3745 err = ext4_ext_get_access(handle, inode, path + depth);
3746 if (err)
3747 goto out;
3748 /* first mark the extent as initialized */
3749 ext4_ext_mark_initialized(ex);
3750
3751 /* note: ext4_ext_correct_indexes() isn't needed here because
3752 * borders are not changed
3753 */
3754 ext4_ext_try_to_merge(handle, inode, path, ex);
3755
3756 /* Mark modified extent as dirty */
3757 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3758out:
3759 ext4_ext_show_leaf(inode, path);
3760 return err;
3761}
3762
3763/*
3764 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3765 */
3766static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3767 ext4_lblk_t lblk,
3768 struct ext4_ext_path *path,
3769 unsigned int len)
3770{
3771 int i, depth;
3772 struct ext4_extent_header *eh;
3773 struct ext4_extent *last_ex;
3774
3775 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3776 return 0;
3777
3778 depth = ext_depth(inode);
3779 eh = path[depth].p_hdr;
3780
3781 /*
3782 * We're going to remove EOFBLOCKS_FL entirely in future so we
3783 * do not care for this case anymore. Simply remove the flag
3784 * if there are no extents.
3785 */
3786 if (unlikely(!eh->eh_entries))
3787 goto out;
3788 last_ex = EXT_LAST_EXTENT(eh);
3789 /*
3790 * We should clear the EOFBLOCKS_FL flag if we are writing the
3791 * last block in the last extent in the file. We test this by
3792 * first checking to see if the caller to
3793 * ext4_ext_get_blocks() was interested in the last block (or
3794 * a block beyond the last block) in the current extent. If
3795 * this turns out to be false, we can bail out from this
3796 * function immediately.
3797 */
3798 if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3799 ext4_ext_get_actual_len(last_ex))
3800 return 0;
3801 /*
3802 * If the caller does appear to be planning to write at or
3803 * beyond the end of the current extent, we then test to see
3804 * if the current extent is the last extent in the file, by
3805 * checking to make sure it was reached via the rightmost node
3806 * at each level of the tree.
3807 */
3808 for (i = depth-1; i >= 0; i--)
3809 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3810 return 0;
3811out:
3812 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3813 return ext4_mark_inode_dirty(handle, inode);
3814}
3815
3816/**
3817 * ext4_find_delalloc_range: find delayed allocated block in the given range.
3818 *
3819 * Return 1 if there is a delalloc block in the range, otherwise 0.
3820 */
3821int ext4_find_delalloc_range(struct inode *inode,
3822 ext4_lblk_t lblk_start,
3823 ext4_lblk_t lblk_end)
3824{
3825 struct extent_status es;
3826
3827 ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es);
3828 if (es.es_len == 0)
3829 return 0; /* there is no delay extent in this tree */
3830 else if (es.es_lblk <= lblk_start &&
3831 lblk_start < es.es_lblk + es.es_len)
3832 return 1;
3833 else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end)
3834 return 1;
3835 else
3836 return 0;
3837}
3838
3839int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
3840{
3841 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3842 ext4_lblk_t lblk_start, lblk_end;
3843 lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
3844 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3845
3846 return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
3847}
3848
3849/**
3850 * Determines how many complete clusters (out of those specified by the 'map')
3851 * are under delalloc and were reserved quota for.
3852 * This function is called when we are writing out the blocks that were
3853 * originally written with their allocation delayed, but then the space was
3854 * allocated using fallocate() before the delayed allocation could be resolved.
3855 * The cases to look for are:
3856 * ('=' indicated delayed allocated blocks
3857 * '-' indicates non-delayed allocated blocks)
3858 * (a) partial clusters towards beginning and/or end outside of allocated range
3859 * are not delalloc'ed.
3860 * Ex:
3861 * |----c---=|====c====|====c====|===-c----|
3862 * |++++++ allocated ++++++|
3863 * ==> 4 complete clusters in above example
3864 *
3865 * (b) partial cluster (outside of allocated range) towards either end is
3866 * marked for delayed allocation. In this case, we will exclude that
3867 * cluster.
3868 * Ex:
3869 * |----====c========|========c========|
3870 * |++++++ allocated ++++++|
3871 * ==> 1 complete clusters in above example
3872 *
3873 * Ex:
3874 * |================c================|
3875 * |++++++ allocated ++++++|
3876 * ==> 0 complete clusters in above example
3877 *
3878 * The ext4_da_update_reserve_space will be called only if we
3879 * determine here that there were some "entire" clusters that span
3880 * this 'allocated' range.
3881 * In the non-bigalloc case, this function will just end up returning num_blks
3882 * without ever calling ext4_find_delalloc_range.
3883 */
3884static unsigned int
3885get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3886 unsigned int num_blks)
3887{
3888 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3889 ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3890 ext4_lblk_t lblk_from, lblk_to, c_offset;
3891 unsigned int allocated_clusters = 0;
3892
3893 alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3894 alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3895
3896 /* max possible clusters for this allocation */
3897 allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3898
3899 trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3900
3901 /* Check towards left side */
3902 c_offset = EXT4_LBLK_COFF(sbi, lblk_start);
3903 if (c_offset) {
3904 lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start);
3905 lblk_to = lblk_from + c_offset - 1;
3906
3907 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3908 allocated_clusters--;
3909 }
3910
3911 /* Now check towards right. */
3912 c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks);
3913 if (allocated_clusters && c_offset) {
3914 lblk_from = lblk_start + num_blks;
3915 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3916
3917 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3918 allocated_clusters--;
3919 }
3920
3921 return allocated_clusters;
3922}
3923
3924static int
3925convert_initialized_extent(handle_t *handle, struct inode *inode,
3926 struct ext4_map_blocks *map,
3927 struct ext4_ext_path **ppath,
3928 unsigned int allocated)
3929{
3930 struct ext4_ext_path *path = *ppath;
3931 struct ext4_extent *ex;
3932 ext4_lblk_t ee_block;
3933 unsigned int ee_len;
3934 int depth;
3935 int err = 0;
3936
3937 /*
3938 * Make sure that the extent is no bigger than we support with
3939 * unwritten extent
3940 */
3941 if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
3942 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
3943
3944 depth = ext_depth(inode);
3945 ex = path[depth].p_ext;
3946 ee_block = le32_to_cpu(ex->ee_block);
3947 ee_len = ext4_ext_get_actual_len(ex);
3948
3949 ext_debug("%s: inode %lu, logical"
3950 "block %llu, max_blocks %u\n", __func__, inode->i_ino,
3951 (unsigned long long)ee_block, ee_len);
3952
3953 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3954 err = ext4_split_convert_extents(handle, inode, map, ppath,
3955 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
3956 if (err < 0)
3957 return err;
3958 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3959 if (IS_ERR(path))
3960 return PTR_ERR(path);
3961 depth = ext_depth(inode);
3962 ex = path[depth].p_ext;
3963 if (!ex) {
3964 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3965 (unsigned long) map->m_lblk);
3966 return -EFSCORRUPTED;
3967 }
3968 }
3969
3970 err = ext4_ext_get_access(handle, inode, path + depth);
3971 if (err)
3972 return err;
3973 /* first mark the extent as unwritten */
3974 ext4_ext_mark_unwritten(ex);
3975
3976 /* note: ext4_ext_correct_indexes() isn't needed here because
3977 * borders are not changed
3978 */
3979 ext4_ext_try_to_merge(handle, inode, path, ex);
3980
3981 /* Mark modified extent as dirty */
3982 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3983 if (err)
3984 return err;
3985 ext4_ext_show_leaf(inode, path);
3986
3987 ext4_update_inode_fsync_trans(handle, inode, 1);
3988 err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len);
3989 if (err)
3990 return err;
3991 map->m_flags |= EXT4_MAP_UNWRITTEN;
3992 if (allocated > map->m_len)
3993 allocated = map->m_len;
3994 map->m_len = allocated;
3995 return allocated;
3996}
3997
3998static int
3999ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
4000 struct ext4_map_blocks *map,
4001 struct ext4_ext_path **ppath, int flags,
4002 unsigned int allocated, ext4_fsblk_t newblock)
4003{
4004 struct ext4_ext_path *path = *ppath;
4005 int ret = 0;
4006 int err = 0;
4007
4008 ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical "
4009 "block %llu, max_blocks %u, flags %x, allocated %u\n",
4010 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
4011 flags, allocated);
4012 ext4_ext_show_leaf(inode, path);
4013
4014 /*
4015 * When writing into unwritten space, we should not fail to
4016 * allocate metadata blocks for the new extent block if needed.
4017 */
4018 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
4019
4020 trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
4021 allocated, newblock);
4022
4023 /* get_block() before submit the IO, split the extent */
4024 if (flags & EXT4_GET_BLOCKS_PRE_IO) {
4025 ret = ext4_split_convert_extents(handle, inode, map, ppath,
4026 flags | EXT4_GET_BLOCKS_CONVERT);
4027 if (ret <= 0)
4028 goto out;
4029 map->m_flags |= EXT4_MAP_UNWRITTEN;
4030 goto out;
4031 }
4032 /* IO end_io complete, convert the filled extent to written */
4033 if (flags & EXT4_GET_BLOCKS_CONVERT) {
4034 if (flags & EXT4_GET_BLOCKS_ZERO) {
4035 if (allocated > map->m_len)
4036 allocated = map->m_len;
4037 err = ext4_issue_zeroout(inode, map->m_lblk, newblock,
4038 allocated);
4039 if (err < 0)
4040 goto out2;
4041 }
4042 ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
4043 ppath);
4044 if (ret >= 0) {
4045 ext4_update_inode_fsync_trans(handle, inode, 1);
4046 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4047 path, map->m_len);
4048 } else
4049 err = ret;
4050 map->m_flags |= EXT4_MAP_MAPPED;
4051 map->m_pblk = newblock;
4052 if (allocated > map->m_len)
4053 allocated = map->m_len;
4054 map->m_len = allocated;
4055 goto out2;
4056 }
4057 /* buffered IO case */
4058 /*
4059 * repeat fallocate creation request
4060 * we already have an unwritten extent
4061 */
4062 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
4063 map->m_flags |= EXT4_MAP_UNWRITTEN;
4064 goto map_out;
4065 }
4066
4067 /* buffered READ or buffered write_begin() lookup */
4068 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4069 /*
4070 * We have blocks reserved already. We
4071 * return allocated blocks so that delalloc
4072 * won't do block reservation for us. But
4073 * the buffer head will be unmapped so that
4074 * a read from the block returns 0s.
4075 */
4076 map->m_flags |= EXT4_MAP_UNWRITTEN;
4077 goto out1;
4078 }
4079
4080 /* buffered write, writepage time, convert*/
4081 ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags);
4082 if (ret >= 0)
4083 ext4_update_inode_fsync_trans(handle, inode, 1);
4084out:
4085 if (ret <= 0) {
4086 err = ret;
4087 goto out2;
4088 } else
4089 allocated = ret;
4090 map->m_flags |= EXT4_MAP_NEW;
4091 /*
4092 * if we allocated more blocks than requested
4093 * we need to make sure we unmap the extra block
4094 * allocated. The actual needed block will get
4095 * unmapped later when we find the buffer_head marked
4096 * new.
4097 */
4098 if (allocated > map->m_len) {
4099 clean_bdev_aliases(inode->i_sb->s_bdev, newblock + map->m_len,
4100 allocated - map->m_len);
4101 allocated = map->m_len;
4102 }
4103 map->m_len = allocated;
4104
4105 /*
4106 * If we have done fallocate with the offset that is already
4107 * delayed allocated, we would have block reservation
4108 * and quota reservation done in the delayed write path.
4109 * But fallocate would have already updated quota and block
4110 * count for this offset. So cancel these reservation
4111 */
4112 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4113 unsigned int reserved_clusters;
4114 reserved_clusters = get_reserved_cluster_alloc(inode,
4115 map->m_lblk, map->m_len);
4116 if (reserved_clusters)
4117 ext4_da_update_reserve_space(inode,
4118 reserved_clusters,
4119 0);
4120 }
4121
4122map_out:
4123 map->m_flags |= EXT4_MAP_MAPPED;
4124 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
4125 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
4126 map->m_len);
4127 if (err < 0)
4128 goto out2;
4129 }
4130out1:
4131 if (allocated > map->m_len)
4132 allocated = map->m_len;
4133 ext4_ext_show_leaf(inode, path);
4134 map->m_pblk = newblock;
4135 map->m_len = allocated;
4136out2:
4137 return err ? err : allocated;
4138}
4139
4140/*
4141 * get_implied_cluster_alloc - check to see if the requested
4142 * allocation (in the map structure) overlaps with a cluster already
4143 * allocated in an extent.
4144 * @sb The filesystem superblock structure
4145 * @map The requested lblk->pblk mapping
4146 * @ex The extent structure which might contain an implied
4147 * cluster allocation
4148 *
4149 * This function is called by ext4_ext_map_blocks() after we failed to
4150 * find blocks that were already in the inode's extent tree. Hence,
4151 * we know that the beginning of the requested region cannot overlap
4152 * the extent from the inode's extent tree. There are three cases we
4153 * want to catch. The first is this case:
4154 *
4155 * |--- cluster # N--|
4156 * |--- extent ---| |---- requested region ---|
4157 * |==========|
4158 *
4159 * The second case that we need to test for is this one:
4160 *
4161 * |--------- cluster # N ----------------|
4162 * |--- requested region --| |------- extent ----|
4163 * |=======================|
4164 *
4165 * The third case is when the requested region lies between two extents
4166 * within the same cluster:
4167 * |------------- cluster # N-------------|
4168 * |----- ex -----| |---- ex_right ----|
4169 * |------ requested region ------|
4170 * |================|
4171 *
4172 * In each of the above cases, we need to set the map->m_pblk and
4173 * map->m_len so it corresponds to the return the extent labelled as
4174 * "|====|" from cluster #N, since it is already in use for data in
4175 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
4176 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
4177 * as a new "allocated" block region. Otherwise, we will return 0 and
4178 * ext4_ext_map_blocks() will then allocate one or more new clusters
4179 * by calling ext4_mb_new_blocks().
4180 */
4181static int get_implied_cluster_alloc(struct super_block *sb,
4182 struct ext4_map_blocks *map,
4183 struct ext4_extent *ex,
4184 struct ext4_ext_path *path)
4185{
4186 struct ext4_sb_info *sbi = EXT4_SB(sb);
4187 ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4188 ext4_lblk_t ex_cluster_start, ex_cluster_end;
4189 ext4_lblk_t rr_cluster_start;
4190 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4191 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4192 unsigned short ee_len = ext4_ext_get_actual_len(ex);
4193
4194 /* The extent passed in that we are trying to match */
4195 ex_cluster_start = EXT4_B2C(sbi, ee_block);
4196 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
4197
4198 /* The requested region passed into ext4_map_blocks() */
4199 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
4200
4201 if ((rr_cluster_start == ex_cluster_end) ||
4202 (rr_cluster_start == ex_cluster_start)) {
4203 if (rr_cluster_start == ex_cluster_end)
4204 ee_start += ee_len - 1;
4205 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
4206 map->m_len = min(map->m_len,
4207 (unsigned) sbi->s_cluster_ratio - c_offset);
4208 /*
4209 * Check for and handle this case:
4210 *
4211 * |--------- cluster # N-------------|
4212 * |------- extent ----|
4213 * |--- requested region ---|
4214 * |===========|
4215 */
4216
4217 if (map->m_lblk < ee_block)
4218 map->m_len = min(map->m_len, ee_block - map->m_lblk);
4219
4220 /*
4221 * Check for the case where there is already another allocated
4222 * block to the right of 'ex' but before the end of the cluster.
4223 *
4224 * |------------- cluster # N-------------|
4225 * |----- ex -----| |---- ex_right ----|
4226 * |------ requested region ------|
4227 * |================|
4228 */
4229 if (map->m_lblk > ee_block) {
4230 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4231 map->m_len = min(map->m_len, next - map->m_lblk);
4232 }
4233
4234 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4235 return 1;
4236 }
4237
4238 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4239 return 0;
4240}
4241
4242
4243/*
4244 * Block allocation/map/preallocation routine for extents based files
4245 *
4246 *
4247 * Need to be called with
4248 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4249 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4250 *
4251 * return > 0, number of of blocks already mapped/allocated
4252 * if create == 0 and these are pre-allocated blocks
4253 * buffer head is unmapped
4254 * otherwise blocks are mapped
4255 *
4256 * return = 0, if plain look up failed (blocks have not been allocated)
4257 * buffer head is unmapped
4258 *
4259 * return < 0, error case.
4260 */
4261int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4262 struct ext4_map_blocks *map, int flags)
4263{
4264 struct ext4_ext_path *path = NULL;
4265 struct ext4_extent newex, *ex, *ex2;
4266 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4267 ext4_fsblk_t newblock = 0;
4268 int free_on_err = 0, err = 0, depth, ret;
4269 unsigned int allocated = 0, offset = 0;
4270 unsigned int allocated_clusters = 0;
4271 struct ext4_allocation_request ar;
4272 ext4_lblk_t cluster_offset;
4273 bool map_from_cluster = false;
4274
4275 ext_debug("blocks %u/%u requested for inode %lu\n",
4276 map->m_lblk, map->m_len, inode->i_ino);
4277 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4278
4279 /* find extent for this block */
4280 path = ext4_find_extent(inode, map->m_lblk, NULL, 0);
4281 if (IS_ERR(path)) {
4282 err = PTR_ERR(path);
4283 path = NULL;
4284 goto out2;
4285 }
4286
4287 depth = ext_depth(inode);
4288
4289 /*
4290 * consistent leaf must not be empty;
4291 * this situation is possible, though, _during_ tree modification;
4292 * this is why assert can't be put in ext4_find_extent()
4293 */
4294 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4295 EXT4_ERROR_INODE(inode, "bad extent address "
4296 "lblock: %lu, depth: %d pblock %lld",
4297 (unsigned long) map->m_lblk, depth,
4298 path[depth].p_block);
4299 err = -EFSCORRUPTED;
4300 goto out2;
4301 }
4302
4303 ex = path[depth].p_ext;
4304 if (ex) {
4305 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4306 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4307 unsigned short ee_len;
4308
4309
4310 /*
4311 * unwritten extents are treated as holes, except that
4312 * we split out initialized portions during a write.
4313 */
4314 ee_len = ext4_ext_get_actual_len(ex);
4315
4316 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4317
4318 /* if found extent covers block, simply return it */
4319 if (in_range(map->m_lblk, ee_block, ee_len)) {
4320 newblock = map->m_lblk - ee_block + ee_start;
4321 /* number of remaining blocks in the extent */
4322 allocated = ee_len - (map->m_lblk - ee_block);
4323 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
4324 ee_block, ee_len, newblock);
4325
4326 /*
4327 * If the extent is initialized check whether the
4328 * caller wants to convert it to unwritten.
4329 */
4330 if ((!ext4_ext_is_unwritten(ex)) &&
4331 (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
4332 allocated = convert_initialized_extent(
4333 handle, inode, map, &path,
4334 allocated);
4335 goto out2;
4336 } else if (!ext4_ext_is_unwritten(ex))
4337 goto out;
4338
4339 ret = ext4_ext_handle_unwritten_extents(
4340 handle, inode, map, &path, flags,
4341 allocated, newblock);
4342 if (ret < 0)
4343 err = ret;
4344 else
4345 allocated = ret;
4346 goto out2;
4347 }
4348 }
4349
4350 /*
4351 * requested block isn't allocated yet;
4352 * we couldn't try to create block if create flag is zero
4353 */
4354 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4355 ext4_lblk_t hole_start, hole_len;
4356
4357 hole_start = map->m_lblk;
4358 hole_len = ext4_ext_determine_hole(inode, path, &hole_start);
4359 /*
4360 * put just found gap into cache to speed up
4361 * subsequent requests
4362 */
4363 ext4_ext_put_gap_in_cache(inode, hole_start, hole_len);
4364
4365 /* Update hole_len to reflect hole size after map->m_lblk */
4366 if (hole_start != map->m_lblk)
4367 hole_len -= map->m_lblk - hole_start;
4368 map->m_pblk = 0;
4369 map->m_len = min_t(unsigned int, map->m_len, hole_len);
4370
4371 goto out2;
4372 }
4373
4374 /*
4375 * Okay, we need to do block allocation.
4376 */
4377 newex.ee_block = cpu_to_le32(map->m_lblk);
4378 cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4379
4380 /*
4381 * If we are doing bigalloc, check to see if the extent returned
4382 * by ext4_find_extent() implies a cluster we can use.
4383 */
4384 if (cluster_offset && ex &&
4385 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4386 ar.len = allocated = map->m_len;
4387 newblock = map->m_pblk;
4388 map_from_cluster = true;
4389 goto got_allocated_blocks;
4390 }
4391
4392 /* find neighbour allocated blocks */
4393 ar.lleft = map->m_lblk;
4394 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4395 if (err)
4396 goto out2;
4397 ar.lright = map->m_lblk;
4398 ex2 = NULL;
4399 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4400 if (err)
4401 goto out2;
4402
4403 /* Check if the extent after searching to the right implies a
4404 * cluster we can use. */
4405 if ((sbi->s_cluster_ratio > 1) && ex2 &&
4406 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
4407 ar.len = allocated = map->m_len;
4408 newblock = map->m_pblk;
4409 map_from_cluster = true;
4410 goto got_allocated_blocks;
4411 }
4412
4413 /*
4414 * See if request is beyond maximum number of blocks we can have in
4415 * a single extent. For an initialized extent this limit is
4416 * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
4417 * EXT_UNWRITTEN_MAX_LEN.
4418 */
4419 if (map->m_len > EXT_INIT_MAX_LEN &&
4420 !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4421 map->m_len = EXT_INIT_MAX_LEN;
4422 else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
4423 (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4424 map->m_len = EXT_UNWRITTEN_MAX_LEN;
4425
4426 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4427 newex.ee_len = cpu_to_le16(map->m_len);
4428 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4429 if (err)
4430 allocated = ext4_ext_get_actual_len(&newex);
4431 else
4432 allocated = map->m_len;
4433
4434 /* allocate new block */
4435 ar.inode = inode;
4436 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4437 ar.logical = map->m_lblk;
4438 /*
4439 * We calculate the offset from the beginning of the cluster
4440 * for the logical block number, since when we allocate a
4441 * physical cluster, the physical block should start at the
4442 * same offset from the beginning of the cluster. This is
4443 * needed so that future calls to get_implied_cluster_alloc()
4444 * work correctly.
4445 */
4446 offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4447 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4448 ar.goal -= offset;
4449 ar.logical -= offset;
4450 if (S_ISREG(inode->i_mode))
4451 ar.flags = EXT4_MB_HINT_DATA;
4452 else
4453 /* disable in-core preallocation for non-regular files */
4454 ar.flags = 0;
4455 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4456 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4457 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4458 ar.flags |= EXT4_MB_DELALLOC_RESERVED;
4459 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
4460 ar.flags |= EXT4_MB_USE_RESERVED;
4461 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4462 if (!newblock)
4463 goto out2;
4464 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4465 ar.goal, newblock, allocated);
4466 free_on_err = 1;
4467 allocated_clusters = ar.len;
4468 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4469 if (ar.len > allocated)
4470 ar.len = allocated;
4471
4472got_allocated_blocks:
4473 /* try to insert new extent into found leaf and return */
4474 ext4_ext_store_pblock(&newex, newblock + offset);
4475 newex.ee_len = cpu_to_le16(ar.len);
4476 /* Mark unwritten */
4477 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){
4478 ext4_ext_mark_unwritten(&newex);
4479 map->m_flags |= EXT4_MAP_UNWRITTEN;
4480 }
4481
4482 err = 0;
4483 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4484 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4485 path, ar.len);
4486 if (!err)
4487 err = ext4_ext_insert_extent(handle, inode, &path,
4488 &newex, flags);
4489
4490 if (err && free_on_err) {
4491 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4492 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4493 /* free data blocks we just allocated */
4494 /* not a good idea to call discard here directly,
4495 * but otherwise we'd need to call it every free() */
4496 ext4_discard_preallocations(inode);
4497 ext4_free_blocks(handle, inode, NULL, newblock,
4498 EXT4_C2B(sbi, allocated_clusters), fb_flags);
4499 goto out2;
4500 }
4501
4502 /* previous routine could use block we allocated */
4503 newblock = ext4_ext_pblock(&newex);
4504 allocated = ext4_ext_get_actual_len(&newex);
4505 if (allocated > map->m_len)
4506 allocated = map->m_len;
4507 map->m_flags |= EXT4_MAP_NEW;
4508
4509 /*
4510 * Update reserved blocks/metadata blocks after successful
4511 * block allocation which had been deferred till now.
4512 */
4513 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4514 unsigned int reserved_clusters;
4515 /*
4516 * Check how many clusters we had reserved this allocated range
4517 */
4518 reserved_clusters = get_reserved_cluster_alloc(inode,
4519 map->m_lblk, allocated);
4520 if (!map_from_cluster) {
4521 BUG_ON(allocated_clusters < reserved_clusters);
4522 if (reserved_clusters < allocated_clusters) {
4523 struct ext4_inode_info *ei = EXT4_I(inode);
4524 int reservation = allocated_clusters -
4525 reserved_clusters;
4526 /*
4527 * It seems we claimed few clusters outside of
4528 * the range of this allocation. We should give
4529 * it back to the reservation pool. This can
4530 * happen in the following case:
4531 *
4532 * * Suppose s_cluster_ratio is 4 (i.e., each
4533 * cluster has 4 blocks. Thus, the clusters
4534 * are [0-3],[4-7],[8-11]...
4535 * * First comes delayed allocation write for
4536 * logical blocks 10 & 11. Since there were no
4537 * previous delayed allocated blocks in the
4538 * range [8-11], we would reserve 1 cluster
4539 * for this write.
4540 * * Next comes write for logical blocks 3 to 8.
4541 * In this case, we will reserve 2 clusters
4542 * (for [0-3] and [4-7]; and not for [8-11] as
4543 * that range has a delayed allocated blocks.
4544 * Thus total reserved clusters now becomes 3.
4545 * * Now, during the delayed allocation writeout
4546 * time, we will first write blocks [3-8] and
4547 * allocate 3 clusters for writing these
4548 * blocks. Also, we would claim all these
4549 * three clusters above.
4550 * * Now when we come here to writeout the
4551 * blocks [10-11], we would expect to claim
4552 * the reservation of 1 cluster we had made
4553 * (and we would claim it since there are no
4554 * more delayed allocated blocks in the range
4555 * [8-11]. But our reserved cluster count had
4556 * already gone to 0.
4557 *
4558 * Thus, at the step 4 above when we determine
4559 * that there are still some unwritten delayed
4560 * allocated blocks outside of our current
4561 * block range, we should increment the
4562 * reserved clusters count so that when the
4563 * remaining blocks finally gets written, we
4564 * could claim them.
4565 */
4566 dquot_reserve_block(inode,
4567 EXT4_C2B(sbi, reservation));
4568 spin_lock(&ei->i_block_reservation_lock);
4569 ei->i_reserved_data_blocks += reservation;
4570 spin_unlock(&ei->i_block_reservation_lock);
4571 }
4572 /*
4573 * We will claim quota for all newly allocated blocks.
4574 * We're updating the reserved space *after* the
4575 * correction above so we do not accidentally free
4576 * all the metadata reservation because we might
4577 * actually need it later on.
4578 */
4579 ext4_da_update_reserve_space(inode, allocated_clusters,
4580 1);
4581 }
4582 }
4583
4584 /*
4585 * Cache the extent and update transaction to commit on fdatasync only
4586 * when it is _not_ an unwritten extent.
4587 */
4588 if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
4589 ext4_update_inode_fsync_trans(handle, inode, 1);
4590 else
4591 ext4_update_inode_fsync_trans(handle, inode, 0);
4592out:
4593 if (allocated > map->m_len)
4594 allocated = map->m_len;
4595 ext4_ext_show_leaf(inode, path);
4596 map->m_flags |= EXT4_MAP_MAPPED;
4597 map->m_pblk = newblock;
4598 map->m_len = allocated;
4599out2:
4600 ext4_ext_drop_refs(path);
4601 kfree(path);
4602
4603 trace_ext4_ext_map_blocks_exit(inode, flags, map,
4604 err ? err : allocated);
4605 return err ? err : allocated;
4606}
4607
4608int ext4_ext_truncate(handle_t *handle, struct inode *inode)
4609{
4610 struct super_block *sb = inode->i_sb;
4611 ext4_lblk_t last_block;
4612 int err = 0;
4613
4614 /*
4615 * TODO: optimization is possible here.
4616 * Probably we need not scan at all,
4617 * because page truncation is enough.
4618 */
4619
4620 /* we have to know where to truncate from in crash case */
4621 EXT4_I(inode)->i_disksize = inode->i_size;
4622 err = ext4_mark_inode_dirty(handle, inode);
4623 if (err)
4624 return err;
4625
4626 last_block = (inode->i_size + sb->s_blocksize - 1)
4627 >> EXT4_BLOCK_SIZE_BITS(sb);
4628retry:
4629 err = ext4_es_remove_extent(inode, last_block,
4630 EXT_MAX_BLOCKS - last_block);
4631 if (err == -ENOMEM) {
4632 cond_resched();
4633 congestion_wait(BLK_RW_ASYNC, HZ/50);
4634 goto retry;
4635 }
4636 if (err)
4637 return err;
4638 return ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4639}
4640
4641static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
4642 ext4_lblk_t len, loff_t new_size,
4643 int flags)
4644{
4645 struct inode *inode = file_inode(file);
4646 handle_t *handle;
4647 int ret = 0;
4648 int ret2 = 0;
4649 int retries = 0;
4650 int depth = 0;
4651 struct ext4_map_blocks map;
4652 unsigned int credits;
4653 loff_t epos;
4654
4655 BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS));
4656 map.m_lblk = offset;
4657 map.m_len = len;
4658 /*
4659 * Don't normalize the request if it can fit in one extent so
4660 * that it doesn't get unnecessarily split into multiple
4661 * extents.
4662 */
4663 if (len <= EXT_UNWRITTEN_MAX_LEN)
4664 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4665
4666 /*
4667 * credits to insert 1 extent into extent tree
4668 */
4669 credits = ext4_chunk_trans_blocks(inode, len);
4670 depth = ext_depth(inode);
4671
4672retry:
4673 while (ret >= 0 && len) {
4674 /*
4675 * Recalculate credits when extent tree depth changes.
4676 */
4677 if (depth != ext_depth(inode)) {
4678 credits = ext4_chunk_trans_blocks(inode, len);
4679 depth = ext_depth(inode);
4680 }
4681
4682 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4683 credits);
4684 if (IS_ERR(handle)) {
4685 ret = PTR_ERR(handle);
4686 break;
4687 }
4688 ret = ext4_map_blocks(handle, inode, &map, flags);
4689 if (ret <= 0) {
4690 ext4_debug("inode #%lu: block %u: len %u: "
4691 "ext4_ext_map_blocks returned %d",
4692 inode->i_ino, map.m_lblk,
4693 map.m_len, ret);
4694 ext4_mark_inode_dirty(handle, inode);
4695 ret2 = ext4_journal_stop(handle);
4696 break;
4697 }
4698 map.m_lblk += ret;
4699 map.m_len = len = len - ret;
4700 epos = (loff_t)map.m_lblk << inode->i_blkbits;
4701 inode->i_ctime = current_time(inode);
4702 if (new_size) {
4703 if (epos > new_size)
4704 epos = new_size;
4705 if (ext4_update_inode_size(inode, epos) & 0x1)
4706 inode->i_mtime = inode->i_ctime;
4707 } else {
4708 if (epos > inode->i_size)
4709 ext4_set_inode_flag(inode,
4710 EXT4_INODE_EOFBLOCKS);
4711 }
4712 ext4_mark_inode_dirty(handle, inode);
4713 ext4_update_inode_fsync_trans(handle, inode, 1);
4714 ret2 = ext4_journal_stop(handle);
4715 if (ret2)
4716 break;
4717 }
4718 if (ret == -ENOSPC &&
4719 ext4_should_retry_alloc(inode->i_sb, &retries)) {
4720 ret = 0;
4721 goto retry;
4722 }
4723
4724 return ret > 0 ? ret2 : ret;
4725}
4726
4727static long ext4_zero_range(struct file *file, loff_t offset,
4728 loff_t len, int mode)
4729{
4730 struct inode *inode = file_inode(file);
4731 handle_t *handle = NULL;
4732 unsigned int max_blocks;
4733 loff_t new_size = 0;
4734 int ret = 0;
4735 int flags;
4736 int credits;
4737 int partial_begin, partial_end;
4738 loff_t start, end;
4739 ext4_lblk_t lblk;
4740 unsigned int blkbits = inode->i_blkbits;
4741
4742 trace_ext4_zero_range(inode, offset, len, mode);
4743
4744 if (!S_ISREG(inode->i_mode))
4745 return -EINVAL;
4746
4747 /* Call ext4_force_commit to flush all data in case of data=journal. */
4748 if (ext4_should_journal_data(inode)) {
4749 ret = ext4_force_commit(inode->i_sb);
4750 if (ret)
4751 return ret;
4752 }
4753
4754 /*
4755 * Round up offset. This is not fallocate, we neet to zero out
4756 * blocks, so convert interior block aligned part of the range to
4757 * unwritten and possibly manually zero out unaligned parts of the
4758 * range.
4759 */
4760 start = round_up(offset, 1 << blkbits);
4761 end = round_down((offset + len), 1 << blkbits);
4762
4763 if (start < offset || end > offset + len)
4764 return -EINVAL;
4765 partial_begin = offset & ((1 << blkbits) - 1);
4766 partial_end = (offset + len) & ((1 << blkbits) - 1);
4767
4768 lblk = start >> blkbits;
4769 max_blocks = (end >> blkbits);
4770 if (max_blocks < lblk)
4771 max_blocks = 0;
4772 else
4773 max_blocks -= lblk;
4774
4775 inode_lock(inode);
4776
4777 /*
4778 * Indirect files do not support unwritten extnets
4779 */
4780 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4781 ret = -EOPNOTSUPP;
4782 goto out_mutex;
4783 }
4784
4785 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4786 (offset + len > i_size_read(inode) ||
4787 offset + len > EXT4_I(inode)->i_disksize)) {
4788 new_size = offset + len;
4789 ret = inode_newsize_ok(inode, new_size);
4790 if (ret)
4791 goto out_mutex;
4792 }
4793
4794 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4795 if (mode & FALLOC_FL_KEEP_SIZE)
4796 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4797
4798 /* Wait all existing dio workers, newcomers will block on i_mutex */
4799 inode_dio_wait(inode);
4800
4801 /* Preallocate the range including the unaligned edges */
4802 if (partial_begin || partial_end) {
4803 ret = ext4_alloc_file_blocks(file,
4804 round_down(offset, 1 << blkbits) >> blkbits,
4805 (round_up((offset + len), 1 << blkbits) -
4806 round_down(offset, 1 << blkbits)) >> blkbits,
4807 new_size, flags);
4808 if (ret)
4809 goto out_mutex;
4810
4811 }
4812
4813 /* Zero range excluding the unaligned edges */
4814 if (max_blocks > 0) {
4815 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
4816 EXT4_EX_NOCACHE);
4817
4818 /*
4819 * Prevent page faults from reinstantiating pages we have
4820 * released from page cache.
4821 */
4822 down_write(&EXT4_I(inode)->i_mmap_sem);
4823 ret = ext4_update_disksize_before_punch(inode, offset, len);
4824 if (ret) {
4825 up_write(&EXT4_I(inode)->i_mmap_sem);
4826 goto out_mutex;
4827 }
4828 /* Now release the pages and zero block aligned part of pages */
4829 truncate_pagecache_range(inode, start, end - 1);
4830 inode->i_mtime = inode->i_ctime = current_time(inode);
4831
4832 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4833 flags);
4834 up_write(&EXT4_I(inode)->i_mmap_sem);
4835 if (ret)
4836 goto out_mutex;
4837 }
4838 if (!partial_begin && !partial_end)
4839 goto out_mutex;
4840
4841 /*
4842 * In worst case we have to writeout two nonadjacent unwritten
4843 * blocks and update the inode
4844 */
4845 credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
4846 if (ext4_should_journal_data(inode))
4847 credits += 2;
4848 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
4849 if (IS_ERR(handle)) {
4850 ret = PTR_ERR(handle);
4851 ext4_std_error(inode->i_sb, ret);
4852 goto out_mutex;
4853 }
4854
4855 inode->i_mtime = inode->i_ctime = current_time(inode);
4856 if (new_size) {
4857 ext4_update_inode_size(inode, new_size);
4858 } else {
4859 /*
4860 * Mark that we allocate beyond EOF so the subsequent truncate
4861 * can proceed even if the new size is the same as i_size.
4862 */
4863 if ((offset + len) > i_size_read(inode))
4864 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4865 }
4866 ext4_mark_inode_dirty(handle, inode);
4867
4868 /* Zero out partial block at the edges of the range */
4869 ret = ext4_zero_partial_blocks(handle, inode, offset, len);
4870 if (ret >= 0)
4871 ext4_update_inode_fsync_trans(handle, inode, 1);
4872
4873 if (file->f_flags & O_SYNC)
4874 ext4_handle_sync(handle);
4875
4876 ext4_journal_stop(handle);
4877out_mutex:
4878 inode_unlock(inode);
4879 return ret;
4880}
4881
4882/*
4883 * preallocate space for a file. This implements ext4's fallocate file
4884 * operation, which gets called from sys_fallocate system call.
4885 * For block-mapped files, posix_fallocate should fall back to the method
4886 * of writing zeroes to the required new blocks (the same behavior which is
4887 * expected for file systems which do not support fallocate() system call).
4888 */
4889long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4890{
4891 struct inode *inode = file_inode(file);
4892 loff_t new_size = 0;
4893 unsigned int max_blocks;
4894 int ret = 0;
4895 int flags;
4896 ext4_lblk_t lblk;
4897 unsigned int blkbits = inode->i_blkbits;
4898
4899 /*
4900 * Encrypted inodes can't handle collapse range or insert
4901 * range since we would need to re-encrypt blocks with a
4902 * different IV or XTS tweak (which are based on the logical
4903 * block number).
4904 *
4905 * XXX It's not clear why zero range isn't working, but we'll
4906 * leave it disabled for encrypted inodes for now. This is a
4907 * bug we should fix....
4908 */
4909 if (ext4_encrypted_inode(inode) &&
4910 (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE |
4911 FALLOC_FL_ZERO_RANGE)))
4912 return -EOPNOTSUPP;
4913
4914 /* Return error if mode is not supported */
4915 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
4916 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
4917 FALLOC_FL_INSERT_RANGE))
4918 return -EOPNOTSUPP;
4919
4920 if (mode & FALLOC_FL_PUNCH_HOLE)
4921 return ext4_punch_hole(inode, offset, len);
4922
4923 ret = ext4_convert_inline_data(inode);
4924 if (ret)
4925 return ret;
4926
4927 if (mode & FALLOC_FL_COLLAPSE_RANGE)
4928 return ext4_collapse_range(inode, offset, len);
4929
4930 if (mode & FALLOC_FL_INSERT_RANGE)
4931 return ext4_insert_range(inode, offset, len);
4932
4933 if (mode & FALLOC_FL_ZERO_RANGE)
4934 return ext4_zero_range(file, offset, len, mode);
4935
4936 trace_ext4_fallocate_enter(inode, offset, len, mode);
4937 lblk = offset >> blkbits;
4938
4939 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
4940 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4941 if (mode & FALLOC_FL_KEEP_SIZE)
4942 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4943
4944 inode_lock(inode);
4945
4946 /*
4947 * We only support preallocation for extent-based files only
4948 */
4949 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4950 ret = -EOPNOTSUPP;
4951 goto out;
4952 }
4953
4954 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4955 (offset + len > i_size_read(inode) ||
4956 offset + len > EXT4_I(inode)->i_disksize)) {
4957 new_size = offset + len;
4958 ret = inode_newsize_ok(inode, new_size);
4959 if (ret)
4960 goto out;
4961 }
4962
4963 /* Wait all existing dio workers, newcomers will block on i_mutex */
4964 inode_dio_wait(inode);
4965
4966 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags);
4967 if (ret)
4968 goto out;
4969
4970 if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
4971 ret = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal,
4972 EXT4_I(inode)->i_sync_tid);
4973 }
4974out:
4975 inode_unlock(inode);
4976 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4977 return ret;
4978}
4979
4980/*
4981 * This function convert a range of blocks to written extents
4982 * The caller of this function will pass the start offset and the size.
4983 * all unwritten extents within this range will be converted to
4984 * written extents.
4985 *
4986 * This function is called from the direct IO end io call back
4987 * function, to convert the fallocated extents after IO is completed.
4988 * Returns 0 on success.
4989 */
4990int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
4991 loff_t offset, ssize_t len)
4992{
4993 unsigned int max_blocks;
4994 int ret = 0;
4995 int ret2 = 0;
4996 struct ext4_map_blocks map;
4997 unsigned int credits, blkbits = inode->i_blkbits;
4998
4999 map.m_lblk = offset >> blkbits;
5000 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
5001
5002 /*
5003 * This is somewhat ugly but the idea is clear: When transaction is
5004 * reserved, everything goes into it. Otherwise we rather start several
5005 * smaller transactions for conversion of each extent separately.
5006 */
5007 if (handle) {
5008 handle = ext4_journal_start_reserved(handle,
5009 EXT4_HT_EXT_CONVERT);
5010 if (IS_ERR(handle))
5011 return PTR_ERR(handle);
5012 credits = 0;
5013 } else {
5014 /*
5015 * credits to insert 1 extent into extent tree
5016 */
5017 credits = ext4_chunk_trans_blocks(inode, max_blocks);
5018 }
5019 while (ret >= 0 && ret < max_blocks) {
5020 map.m_lblk += ret;
5021 map.m_len = (max_blocks -= ret);
5022 if (credits) {
5023 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
5024 credits);
5025 if (IS_ERR(handle)) {
5026 ret = PTR_ERR(handle);
5027 break;
5028 }
5029 }
5030 ret = ext4_map_blocks(handle, inode, &map,
5031 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
5032 if (ret <= 0)
5033 ext4_warning(inode->i_sb,
5034 "inode #%lu: block %u: len %u: "
5035 "ext4_ext_map_blocks returned %d",
5036 inode->i_ino, map.m_lblk,
5037 map.m_len, ret);
5038 ext4_mark_inode_dirty(handle, inode);
5039 if (credits)
5040 ret2 = ext4_journal_stop(handle);
5041 if (ret <= 0 || ret2)
5042 break;
5043 }
5044 if (!credits)
5045 ret2 = ext4_journal_stop(handle);
5046 return ret > 0 ? ret2 : ret;
5047}
5048
5049/*
5050 * If newes is not existing extent (newes->ec_pblk equals zero) find
5051 * delayed extent at start of newes and update newes accordingly and
5052 * return start of the next delayed extent.
5053 *
5054 * If newes is existing extent (newes->ec_pblk is not equal zero)
5055 * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
5056 * extent found. Leave newes unmodified.
5057 */
5058static int ext4_find_delayed_extent(struct inode *inode,
5059 struct extent_status *newes)
5060{
5061 struct extent_status es;
5062 ext4_lblk_t block, next_del;
5063
5064 if (newes->es_pblk == 0) {
5065 ext4_es_find_delayed_extent_range(inode, newes->es_lblk,
5066 newes->es_lblk + newes->es_len - 1, &es);
5067
5068 /*
5069 * No extent in extent-tree contains block @newes->es_pblk,
5070 * then the block may stay in 1)a hole or 2)delayed-extent.
5071 */
5072 if (es.es_len == 0)
5073 /* A hole found. */
5074 return 0;
5075
5076 if (es.es_lblk > newes->es_lblk) {
5077 /* A hole found. */
5078 newes->es_len = min(es.es_lblk - newes->es_lblk,
5079 newes->es_len);
5080 return 0;
5081 }
5082
5083 newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
5084 }
5085
5086 block = newes->es_lblk + newes->es_len;
5087 ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es);
5088 if (es.es_len == 0)
5089 next_del = EXT_MAX_BLOCKS;
5090 else
5091 next_del = es.es_lblk;
5092
5093 return next_del;
5094}
5095/* fiemap flags we can handle specified here */
5096#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
5097
5098static int ext4_xattr_fiemap(struct inode *inode,
5099 struct fiemap_extent_info *fieinfo)
5100{
5101 __u64 physical = 0;
5102 __u64 length;
5103 __u32 flags = FIEMAP_EXTENT_LAST;
5104 int blockbits = inode->i_sb->s_blocksize_bits;
5105 int error = 0;
5106
5107 /* in-inode? */
5108 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
5109 struct ext4_iloc iloc;
5110 int offset; /* offset of xattr in inode */
5111
5112 error = ext4_get_inode_loc(inode, &iloc);
5113 if (error)
5114 return error;
5115 physical = (__u64)iloc.bh->b_blocknr << blockbits;
5116 offset = EXT4_GOOD_OLD_INODE_SIZE +
5117 EXT4_I(inode)->i_extra_isize;
5118 physical += offset;
5119 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
5120 flags |= FIEMAP_EXTENT_DATA_INLINE;
5121 brelse(iloc.bh);
5122 } else { /* external block */
5123 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
5124 length = inode->i_sb->s_blocksize;
5125 }
5126
5127 if (physical)
5128 error = fiemap_fill_next_extent(fieinfo, 0, physical,
5129 length, flags);
5130 return (error < 0 ? error : 0);
5131}
5132
5133int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
5134 __u64 start, __u64 len)
5135{
5136 ext4_lblk_t start_blk;
5137 int error = 0;
5138
5139 if (ext4_has_inline_data(inode)) {
5140 int has_inline = 1;
5141
5142 error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
5143 start, len);
5144
5145 if (has_inline)
5146 return error;
5147 }
5148
5149 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
5150 error = ext4_ext_precache(inode);
5151 if (error)
5152 return error;
5153 }
5154
5155 /* fallback to generic here if not in extents fmt */
5156 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
5157 return generic_block_fiemap(inode, fieinfo, start, len,
5158 ext4_get_block);
5159
5160 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
5161 return -EBADR;
5162
5163 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
5164 error = ext4_xattr_fiemap(inode, fieinfo);
5165 } else {
5166 ext4_lblk_t len_blks;
5167 __u64 last_blk;
5168
5169 start_blk = start >> inode->i_sb->s_blocksize_bits;
5170 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
5171 if (last_blk >= EXT_MAX_BLOCKS)
5172 last_blk = EXT_MAX_BLOCKS-1;
5173 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
5174
5175 /*
5176 * Walk the extent tree gathering extent information
5177 * and pushing extents back to the user.
5178 */
5179 error = ext4_fill_fiemap_extents(inode, start_blk,
5180 len_blks, fieinfo);
5181 }
5182 return error;
5183}
5184
5185/*
5186 * ext4_access_path:
5187 * Function to access the path buffer for marking it dirty.
5188 * It also checks if there are sufficient credits left in the journal handle
5189 * to update path.
5190 */
5191static int
5192ext4_access_path(handle_t *handle, struct inode *inode,
5193 struct ext4_ext_path *path)
5194{
5195 int credits, err;
5196
5197 if (!ext4_handle_valid(handle))
5198 return 0;
5199
5200 /*
5201 * Check if need to extend journal credits
5202 * 3 for leaf, sb, and inode plus 2 (bmap and group
5203 * descriptor) for each block group; assume two block
5204 * groups
5205 */
5206 if (handle->h_buffer_credits < 7) {
5207 credits = ext4_writepage_trans_blocks(inode);
5208 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
5209 /* EAGAIN is success */
5210 if (err && err != -EAGAIN)
5211 return err;
5212 }
5213
5214 err = ext4_ext_get_access(handle, inode, path);
5215 return err;
5216}
5217
5218/*
5219 * ext4_ext_shift_path_extents:
5220 * Shift the extents of a path structure lying between path[depth].p_ext
5221 * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
5222 * if it is right shift or left shift operation.
5223 */
5224static int
5225ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
5226 struct inode *inode, handle_t *handle,
5227 enum SHIFT_DIRECTION SHIFT)
5228{
5229 int depth, err = 0;
5230 struct ext4_extent *ex_start, *ex_last;
5231 bool update = 0;
5232 depth = path->p_depth;
5233
5234 while (depth >= 0) {
5235 if (depth == path->p_depth) {
5236 ex_start = path[depth].p_ext;
5237 if (!ex_start)
5238 return -EFSCORRUPTED;
5239
5240 ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
5241
5242 err = ext4_access_path(handle, inode, path + depth);
5243 if (err)
5244 goto out;
5245
5246 if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr))
5247 update = 1;
5248
5249 while (ex_start <= ex_last) {
5250 if (SHIFT == SHIFT_LEFT) {
5251 le32_add_cpu(&ex_start->ee_block,
5252 -shift);
5253 /* Try to merge to the left. */
5254 if ((ex_start >
5255 EXT_FIRST_EXTENT(path[depth].p_hdr))
5256 &&
5257 ext4_ext_try_to_merge_right(inode,
5258 path, ex_start - 1))
5259 ex_last--;
5260 else
5261 ex_start++;
5262 } else {
5263 le32_add_cpu(&ex_last->ee_block, shift);
5264 ext4_ext_try_to_merge_right(inode, path,
5265 ex_last);
5266 ex_last--;
5267 }
5268 }
5269 err = ext4_ext_dirty(handle, inode, path + depth);
5270 if (err)
5271 goto out;
5272
5273 if (--depth < 0 || !update)
5274 break;
5275 }
5276
5277 /* Update index too */
5278 err = ext4_access_path(handle, inode, path + depth);
5279 if (err)
5280 goto out;
5281
5282 if (SHIFT == SHIFT_LEFT)
5283 le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
5284 else
5285 le32_add_cpu(&path[depth].p_idx->ei_block, shift);
5286 err = ext4_ext_dirty(handle, inode, path + depth);
5287 if (err)
5288 goto out;
5289
5290 /* we are done if current index is not a starting index */
5291 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
5292 break;
5293
5294 depth--;
5295 }
5296
5297out:
5298 return err;
5299}
5300
5301/*
5302 * ext4_ext_shift_extents:
5303 * All the extents which lies in the range from @start to the last allocated
5304 * block for the @inode are shifted either towards left or right (depending
5305 * upon @SHIFT) by @shift blocks.
5306 * On success, 0 is returned, error otherwise.
5307 */
5308static int
5309ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
5310 ext4_lblk_t start, ext4_lblk_t shift,
5311 enum SHIFT_DIRECTION SHIFT)
5312{
5313 struct ext4_ext_path *path;
5314 int ret = 0, depth;
5315 struct ext4_extent *extent;
5316 ext4_lblk_t stop, *iterator, ex_start, ex_end;
5317
5318 /* Let path point to the last extent */
5319 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
5320 EXT4_EX_NOCACHE);
5321 if (IS_ERR(path))
5322 return PTR_ERR(path);
5323
5324 depth = path->p_depth;
5325 extent = path[depth].p_ext;
5326 if (!extent)
5327 goto out;
5328
5329 stop = le32_to_cpu(extent->ee_block);
5330
5331 /*
5332 * For left shifts, make sure the hole on the left is big enough to
5333 * accommodate the shift. For right shifts, make sure the last extent
5334 * won't be shifted beyond EXT_MAX_BLOCKS.
5335 */
5336 if (SHIFT == SHIFT_LEFT) {
5337 path = ext4_find_extent(inode, start - 1, &path,
5338 EXT4_EX_NOCACHE);
5339 if (IS_ERR(path))
5340 return PTR_ERR(path);
5341 depth = path->p_depth;
5342 extent = path[depth].p_ext;
5343 if (extent) {
5344 ex_start = le32_to_cpu(extent->ee_block);
5345 ex_end = le32_to_cpu(extent->ee_block) +
5346 ext4_ext_get_actual_len(extent);
5347 } else {
5348 ex_start = 0;
5349 ex_end = 0;
5350 }
5351
5352 if ((start == ex_start && shift > ex_start) ||
5353 (shift > start - ex_end)) {
5354 ret = -EINVAL;
5355 goto out;
5356 }
5357 } else {
5358 if (shift > EXT_MAX_BLOCKS -
5359 (stop + ext4_ext_get_actual_len(extent))) {
5360 ret = -EINVAL;
5361 goto out;
5362 }
5363 }
5364
5365 /*
5366 * In case of left shift, iterator points to start and it is increased
5367 * till we reach stop. In case of right shift, iterator points to stop
5368 * and it is decreased till we reach start.
5369 */
5370 if (SHIFT == SHIFT_LEFT)
5371 iterator = &start;
5372 else
5373 iterator = &stop;
5374
5375 /*
5376 * Its safe to start updating extents. Start and stop are unsigned, so
5377 * in case of right shift if extent with 0 block is reached, iterator
5378 * becomes NULL to indicate the end of the loop.
5379 */
5380 while (iterator && start <= stop) {
5381 path = ext4_find_extent(inode, *iterator, &path,
5382 EXT4_EX_NOCACHE);
5383 if (IS_ERR(path))
5384 return PTR_ERR(path);
5385 depth = path->p_depth;
5386 extent = path[depth].p_ext;
5387 if (!extent) {
5388 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
5389 (unsigned long) *iterator);
5390 return -EFSCORRUPTED;
5391 }
5392 if (SHIFT == SHIFT_LEFT && *iterator >
5393 le32_to_cpu(extent->ee_block)) {
5394 /* Hole, move to the next extent */
5395 if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
5396 path[depth].p_ext++;
5397 } else {
5398 *iterator = ext4_ext_next_allocated_block(path);
5399 continue;
5400 }
5401 }
5402
5403 if (SHIFT == SHIFT_LEFT) {
5404 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5405 *iterator = le32_to_cpu(extent->ee_block) +
5406 ext4_ext_get_actual_len(extent);
5407 } else {
5408 extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
5409 if (le32_to_cpu(extent->ee_block) > 0)
5410 *iterator = le32_to_cpu(extent->ee_block) - 1;
5411 else
5412 /* Beginning is reached, end of the loop */
5413 iterator = NULL;
5414 /* Update path extent in case we need to stop */
5415 while (le32_to_cpu(extent->ee_block) < start)
5416 extent++;
5417 path[depth].p_ext = extent;
5418 }
5419 ret = ext4_ext_shift_path_extents(path, shift, inode,
5420 handle, SHIFT);
5421 if (ret)
5422 break;
5423 }
5424out:
5425 ext4_ext_drop_refs(path);
5426 kfree(path);
5427 return ret;
5428}
5429
5430/*
5431 * ext4_collapse_range:
5432 * This implements the fallocate's collapse range functionality for ext4
5433 * Returns: 0 and non-zero on error.
5434 */
5435int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
5436{
5437 struct super_block *sb = inode->i_sb;
5438 ext4_lblk_t punch_start, punch_stop;
5439 handle_t *handle;
5440 unsigned int credits;
5441 loff_t new_size, ioffset;
5442 int ret;
5443
5444 /*
5445 * We need to test this early because xfstests assumes that a
5446 * collapse range of (0, 1) will return EOPNOTSUPP if the file
5447 * system does not support collapse range.
5448 */
5449 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5450 return -EOPNOTSUPP;
5451
5452 /* Collapse range works only on fs block size aligned offsets. */
5453 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
5454 len & (EXT4_CLUSTER_SIZE(sb) - 1))
5455 return -EINVAL;
5456
5457 if (!S_ISREG(inode->i_mode))
5458 return -EINVAL;
5459
5460 trace_ext4_collapse_range(inode, offset, len);
5461
5462 punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5463 punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb);
5464
5465 /* Call ext4_force_commit to flush all data in case of data=journal. */
5466 if (ext4_should_journal_data(inode)) {
5467 ret = ext4_force_commit(inode->i_sb);
5468 if (ret)
5469 return ret;
5470 }
5471
5472 inode_lock(inode);
5473 /*
5474 * There is no need to overlap collapse range with EOF, in which case
5475 * it is effectively a truncate operation
5476 */
5477 if (offset + len >= i_size_read(inode)) {
5478 ret = -EINVAL;
5479 goto out_mutex;
5480 }
5481
5482 /* Currently just for extent based files */
5483 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5484 ret = -EOPNOTSUPP;
5485 goto out_mutex;
5486 }
5487
5488 /* Wait for existing dio to complete */
5489 inode_dio_wait(inode);
5490
5491 /*
5492 * Prevent page faults from reinstantiating pages we have released from
5493 * page cache.
5494 */
5495 down_write(&EXT4_I(inode)->i_mmap_sem);
5496 /*
5497 * Need to round down offset to be aligned with page size boundary
5498 * for page size > block size.
5499 */
5500 ioffset = round_down(offset, PAGE_SIZE);
5501 /*
5502 * Write tail of the last page before removed range since it will get
5503 * removed from the page cache below.
5504 */
5505 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, offset);
5506 if (ret)
5507 goto out_mmap;
5508 /*
5509 * Write data that will be shifted to preserve them when discarding
5510 * page cache below. We are also protected from pages becoming dirty
5511 * by i_mmap_sem.
5512 */
5513 ret = filemap_write_and_wait_range(inode->i_mapping, offset + len,
5514 LLONG_MAX);
5515 if (ret)
5516 goto out_mmap;
5517 truncate_pagecache(inode, ioffset);
5518
5519 credits = ext4_writepage_trans_blocks(inode);
5520 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5521 if (IS_ERR(handle)) {
5522 ret = PTR_ERR(handle);
5523 goto out_mmap;
5524 }
5525
5526 down_write(&EXT4_I(inode)->i_data_sem);
5527 ext4_discard_preallocations(inode);
5528
5529 ret = ext4_es_remove_extent(inode, punch_start,
5530 EXT_MAX_BLOCKS - punch_start);
5531 if (ret) {
5532 up_write(&EXT4_I(inode)->i_data_sem);
5533 goto out_stop;
5534 }
5535
5536 ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
5537 if (ret) {
5538 up_write(&EXT4_I(inode)->i_data_sem);
5539 goto out_stop;
5540 }
5541 ext4_discard_preallocations(inode);
5542
5543 ret = ext4_ext_shift_extents(inode, handle, punch_stop,
5544 punch_stop - punch_start, SHIFT_LEFT);
5545 if (ret) {
5546 up_write(&EXT4_I(inode)->i_data_sem);
5547 goto out_stop;
5548 }
5549
5550 new_size = i_size_read(inode) - len;
5551 i_size_write(inode, new_size);
5552 EXT4_I(inode)->i_disksize = new_size;
5553
5554 up_write(&EXT4_I(inode)->i_data_sem);
5555 if (IS_SYNC(inode))
5556 ext4_handle_sync(handle);
5557 inode->i_mtime = inode->i_ctime = current_time(inode);
5558 ext4_mark_inode_dirty(handle, inode);
5559 ext4_update_inode_fsync_trans(handle, inode, 1);
5560
5561out_stop:
5562 ext4_journal_stop(handle);
5563out_mmap:
5564 up_write(&EXT4_I(inode)->i_mmap_sem);
5565out_mutex:
5566 inode_unlock(inode);
5567 return ret;
5568}
5569
5570/*
5571 * ext4_insert_range:
5572 * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
5573 * The data blocks starting from @offset to the EOF are shifted by @len
5574 * towards right to create a hole in the @inode. Inode size is increased
5575 * by len bytes.
5576 * Returns 0 on success, error otherwise.
5577 */
5578int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
5579{
5580 struct super_block *sb = inode->i_sb;
5581 handle_t *handle;
5582 struct ext4_ext_path *path;
5583 struct ext4_extent *extent;
5584 ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
5585 unsigned int credits, ee_len;
5586 int ret = 0, depth, split_flag = 0;
5587 loff_t ioffset;
5588
5589 /*
5590 * We need to test this early because xfstests assumes that an
5591 * insert range of (0, 1) will return EOPNOTSUPP if the file
5592 * system does not support insert range.
5593 */
5594 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5595 return -EOPNOTSUPP;
5596
5597 /* Insert range works only on fs block size aligned offsets. */
5598 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
5599 len & (EXT4_CLUSTER_SIZE(sb) - 1))
5600 return -EINVAL;
5601
5602 if (!S_ISREG(inode->i_mode))
5603 return -EOPNOTSUPP;
5604
5605 trace_ext4_insert_range(inode, offset, len);
5606
5607 offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5608 len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
5609
5610 /* Call ext4_force_commit to flush all data in case of data=journal */
5611 if (ext4_should_journal_data(inode)) {
5612 ret = ext4_force_commit(inode->i_sb);
5613 if (ret)
5614 return ret;
5615 }
5616
5617 inode_lock(inode);
5618 /* Currently just for extent based files */
5619 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5620 ret = -EOPNOTSUPP;
5621 goto out_mutex;
5622 }
5623
5624 /* Check for wrap through zero */
5625 if (inode->i_size + len > inode->i_sb->s_maxbytes) {
5626 ret = -EFBIG;
5627 goto out_mutex;
5628 }
5629
5630 /* Offset should be less than i_size */
5631 if (offset >= i_size_read(inode)) {
5632 ret = -EINVAL;
5633 goto out_mutex;
5634 }
5635
5636 /* Wait for existing dio to complete */
5637 inode_dio_wait(inode);
5638
5639 /*
5640 * Prevent page faults from reinstantiating pages we have released from
5641 * page cache.
5642 */
5643 down_write(&EXT4_I(inode)->i_mmap_sem);
5644 /*
5645 * Need to round down to align start offset to page size boundary
5646 * for page size > block size.
5647 */
5648 ioffset = round_down(offset, PAGE_SIZE);
5649 /* Write out all dirty pages */
5650 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5651 LLONG_MAX);
5652 if (ret)
5653 goto out_mmap;
5654 truncate_pagecache(inode, ioffset);
5655
5656 credits = ext4_writepage_trans_blocks(inode);
5657 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5658 if (IS_ERR(handle)) {
5659 ret = PTR_ERR(handle);
5660 goto out_mmap;
5661 }
5662
5663 /* Expand file to avoid data loss if there is error while shifting */
5664 inode->i_size += len;
5665 EXT4_I(inode)->i_disksize += len;
5666 inode->i_mtime = inode->i_ctime = current_time(inode);
5667 ret = ext4_mark_inode_dirty(handle, inode);
5668 if (ret)
5669 goto out_stop;
5670
5671 down_write(&EXT4_I(inode)->i_data_sem);
5672 ext4_discard_preallocations(inode);
5673
5674 path = ext4_find_extent(inode, offset_lblk, NULL, 0);
5675 if (IS_ERR(path)) {
5676 up_write(&EXT4_I(inode)->i_data_sem);
5677 goto out_stop;
5678 }
5679
5680 depth = ext_depth(inode);
5681 extent = path[depth].p_ext;
5682 if (extent) {
5683 ee_start_lblk = le32_to_cpu(extent->ee_block);
5684 ee_len = ext4_ext_get_actual_len(extent);
5685
5686 /*
5687 * If offset_lblk is not the starting block of extent, split
5688 * the extent @offset_lblk
5689 */
5690 if ((offset_lblk > ee_start_lblk) &&
5691 (offset_lblk < (ee_start_lblk + ee_len))) {
5692 if (ext4_ext_is_unwritten(extent))
5693 split_flag = EXT4_EXT_MARK_UNWRIT1 |
5694 EXT4_EXT_MARK_UNWRIT2;
5695 ret = ext4_split_extent_at(handle, inode, &path,
5696 offset_lblk, split_flag,
5697 EXT4_EX_NOCACHE |
5698 EXT4_GET_BLOCKS_PRE_IO |
5699 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5700 }
5701
5702 ext4_ext_drop_refs(path);
5703 kfree(path);
5704 if (ret < 0) {
5705 up_write(&EXT4_I(inode)->i_data_sem);
5706 goto out_stop;
5707 }
5708 } else {
5709 ext4_ext_drop_refs(path);
5710 kfree(path);
5711 }
5712
5713 ret = ext4_es_remove_extent(inode, offset_lblk,
5714 EXT_MAX_BLOCKS - offset_lblk);
5715 if (ret) {
5716 up_write(&EXT4_I(inode)->i_data_sem);
5717 goto out_stop;
5718 }
5719
5720 /*
5721 * if offset_lblk lies in a hole which is at start of file, use
5722 * ee_start_lblk to shift extents
5723 */
5724 ret = ext4_ext_shift_extents(inode, handle,
5725 ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk,
5726 len_lblk, SHIFT_RIGHT);
5727
5728 up_write(&EXT4_I(inode)->i_data_sem);
5729 if (IS_SYNC(inode))
5730 ext4_handle_sync(handle);
5731 if (ret >= 0)
5732 ext4_update_inode_fsync_trans(handle, inode, 1);
5733
5734out_stop:
5735 ext4_journal_stop(handle);
5736out_mmap:
5737 up_write(&EXT4_I(inode)->i_mmap_sem);
5738out_mutex:
5739 inode_unlock(inode);
5740 return ret;
5741}
5742
5743/**
5744 * ext4_swap_extents - Swap extents between two inodes
5745 *
5746 * @inode1: First inode
5747 * @inode2: Second inode
5748 * @lblk1: Start block for first inode
5749 * @lblk2: Start block for second inode
5750 * @count: Number of blocks to swap
5751 * @unwritten: Mark second inode's extents as unwritten after swap
5752 * @erp: Pointer to save error value
5753 *
5754 * This helper routine does exactly what is promise "swap extents". All other
5755 * stuff such as page-cache locking consistency, bh mapping consistency or
5756 * extent's data copying must be performed by caller.
5757 * Locking:
5758 * i_mutex is held for both inodes
5759 * i_data_sem is locked for write for both inodes
5760 * Assumptions:
5761 * All pages from requested range are locked for both inodes
5762 */
5763int
5764ext4_swap_extents(handle_t *handle, struct inode *inode1,
5765 struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
5766 ext4_lblk_t count, int unwritten, int *erp)
5767{
5768 struct ext4_ext_path *path1 = NULL;
5769 struct ext4_ext_path *path2 = NULL;
5770 int replaced_count = 0;
5771
5772 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
5773 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
5774 BUG_ON(!inode_is_locked(inode1));
5775 BUG_ON(!inode_is_locked(inode2));
5776
5777 *erp = ext4_es_remove_extent(inode1, lblk1, count);
5778 if (unlikely(*erp))
5779 return 0;
5780 *erp = ext4_es_remove_extent(inode2, lblk2, count);
5781 if (unlikely(*erp))
5782 return 0;
5783
5784 while (count) {
5785 struct ext4_extent *ex1, *ex2, tmp_ex;
5786 ext4_lblk_t e1_blk, e2_blk;
5787 int e1_len, e2_len, len;
5788 int split = 0;
5789
5790 path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE);
5791 if (IS_ERR(path1)) {
5792 *erp = PTR_ERR(path1);
5793 path1 = NULL;
5794 finish:
5795 count = 0;
5796 goto repeat;
5797 }
5798 path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE);
5799 if (IS_ERR(path2)) {
5800 *erp = PTR_ERR(path2);
5801 path2 = NULL;
5802 goto finish;
5803 }
5804 ex1 = path1[path1->p_depth].p_ext;
5805 ex2 = path2[path2->p_depth].p_ext;
5806 /* Do we have somthing to swap ? */
5807 if (unlikely(!ex2 || !ex1))
5808 goto finish;
5809
5810 e1_blk = le32_to_cpu(ex1->ee_block);
5811 e2_blk = le32_to_cpu(ex2->ee_block);
5812 e1_len = ext4_ext_get_actual_len(ex1);
5813 e2_len = ext4_ext_get_actual_len(ex2);
5814
5815 /* Hole handling */
5816 if (!in_range(lblk1, e1_blk, e1_len) ||
5817 !in_range(lblk2, e2_blk, e2_len)) {
5818 ext4_lblk_t next1, next2;
5819
5820 /* if hole after extent, then go to next extent */
5821 next1 = ext4_ext_next_allocated_block(path1);
5822 next2 = ext4_ext_next_allocated_block(path2);
5823 /* If hole before extent, then shift to that extent */
5824 if (e1_blk > lblk1)
5825 next1 = e1_blk;
5826 if (e2_blk > lblk2)
5827 next2 = e2_blk;
5828 /* Do we have something to swap */
5829 if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
5830 goto finish;
5831 /* Move to the rightest boundary */
5832 len = next1 - lblk1;
5833 if (len < next2 - lblk2)
5834 len = next2 - lblk2;
5835 if (len > count)
5836 len = count;
5837 lblk1 += len;
5838 lblk2 += len;
5839 count -= len;
5840 goto repeat;
5841 }
5842
5843 /* Prepare left boundary */
5844 if (e1_blk < lblk1) {
5845 split = 1;
5846 *erp = ext4_force_split_extent_at(handle, inode1,
5847 &path1, lblk1, 0);
5848 if (unlikely(*erp))
5849 goto finish;
5850 }
5851 if (e2_blk < lblk2) {
5852 split = 1;
5853 *erp = ext4_force_split_extent_at(handle, inode2,
5854 &path2, lblk2, 0);
5855 if (unlikely(*erp))
5856 goto finish;
5857 }
5858 /* ext4_split_extent_at() may result in leaf extent split,
5859 * path must to be revalidated. */
5860 if (split)
5861 goto repeat;
5862
5863 /* Prepare right boundary */
5864 len = count;
5865 if (len > e1_blk + e1_len - lblk1)
5866 len = e1_blk + e1_len - lblk1;
5867 if (len > e2_blk + e2_len - lblk2)
5868 len = e2_blk + e2_len - lblk2;
5869
5870 if (len != e1_len) {
5871 split = 1;
5872 *erp = ext4_force_split_extent_at(handle, inode1,
5873 &path1, lblk1 + len, 0);
5874 if (unlikely(*erp))
5875 goto finish;
5876 }
5877 if (len != e2_len) {
5878 split = 1;
5879 *erp = ext4_force_split_extent_at(handle, inode2,
5880 &path2, lblk2 + len, 0);
5881 if (*erp)
5882 goto finish;
5883 }
5884 /* ext4_split_extent_at() may result in leaf extent split,
5885 * path must to be revalidated. */
5886 if (split)
5887 goto repeat;
5888
5889 BUG_ON(e2_len != e1_len);
5890 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
5891 if (unlikely(*erp))
5892 goto finish;
5893 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
5894 if (unlikely(*erp))
5895 goto finish;
5896
5897 /* Both extents are fully inside boundaries. Swap it now */
5898 tmp_ex = *ex1;
5899 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
5900 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
5901 ex1->ee_len = cpu_to_le16(e2_len);
5902 ex2->ee_len = cpu_to_le16(e1_len);
5903 if (unwritten)
5904 ext4_ext_mark_unwritten(ex2);
5905 if (ext4_ext_is_unwritten(&tmp_ex))
5906 ext4_ext_mark_unwritten(ex1);
5907
5908 ext4_ext_try_to_merge(handle, inode2, path2, ex2);
5909 ext4_ext_try_to_merge(handle, inode1, path1, ex1);
5910 *erp = ext4_ext_dirty(handle, inode2, path2 +
5911 path2->p_depth);
5912 if (unlikely(*erp))
5913 goto finish;
5914 *erp = ext4_ext_dirty(handle, inode1, path1 +
5915 path1->p_depth);
5916 /*
5917 * Looks scarry ah..? second inode already points to new blocks,
5918 * and it was successfully dirtied. But luckily error may happen
5919 * only due to journal error, so full transaction will be
5920 * aborted anyway.
5921 */
5922 if (unlikely(*erp))
5923 goto finish;
5924 lblk1 += len;
5925 lblk2 += len;
5926 replaced_count += len;
5927 count -= len;
5928
5929 repeat:
5930 ext4_ext_drop_refs(path1);
5931 kfree(path1);
5932 ext4_ext_drop_refs(path2);
5933 kfree(path2);
5934 path1 = path2 = NULL;
5935 }
5936 return replaced_count;
5937}