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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 <linux/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 /*
126 * If we need to extend the journal get a few extra blocks
127 * while we're at it for efficiency's sake.
128 */
129 needed += 3;
130 err = ext4_journal_extend(handle, needed - handle->h_buffer_credits);
131 if (err <= 0)
132 return err;
133 err = ext4_truncate_restart_trans(handle, inode, needed);
134 if (err == 0)
135 err = -EAGAIN;
136
137 return err;
138}
139
140/*
141 * could return:
142 * - EROFS
143 * - ENOMEM
144 */
145static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
146 struct ext4_ext_path *path)
147{
148 if (path->p_bh) {
149 /* path points to block */
150 BUFFER_TRACE(path->p_bh, "get_write_access");
151 return ext4_journal_get_write_access(handle, path->p_bh);
152 }
153 /* path points to leaf/index in inode body */
154 /* we use in-core data, no need to protect them */
155 return 0;
156}
157
158/*
159 * could return:
160 * - EROFS
161 * - ENOMEM
162 * - EIO
163 */
164int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle,
165 struct inode *inode, struct ext4_ext_path *path)
166{
167 int err;
168
169 WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
170 if (path->p_bh) {
171 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
172 /* path points to block */
173 err = __ext4_handle_dirty_metadata(where, line, handle,
174 inode, path->p_bh);
175 } else {
176 /* path points to leaf/index in inode body */
177 err = ext4_mark_inode_dirty(handle, inode);
178 }
179 return err;
180}
181
182static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
183 struct ext4_ext_path *path,
184 ext4_lblk_t block)
185{
186 if (path) {
187 int depth = path->p_depth;
188 struct ext4_extent *ex;
189
190 /*
191 * Try to predict block placement assuming that we are
192 * filling in a file which will eventually be
193 * non-sparse --- i.e., in the case of libbfd writing
194 * an ELF object sections out-of-order but in a way
195 * the eventually results in a contiguous object or
196 * executable file, or some database extending a table
197 * space file. However, this is actually somewhat
198 * non-ideal if we are writing a sparse file such as
199 * qemu or KVM writing a raw image file that is going
200 * to stay fairly sparse, since it will end up
201 * fragmenting the file system's free space. Maybe we
202 * should have some hueristics or some way to allow
203 * userspace to pass a hint to file system,
204 * especially if the latter case turns out to be
205 * common.
206 */
207 ex = path[depth].p_ext;
208 if (ex) {
209 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
210 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
211
212 if (block > ext_block)
213 return ext_pblk + (block - ext_block);
214 else
215 return ext_pblk - (ext_block - block);
216 }
217
218 /* it looks like index is empty;
219 * try to find starting block from index itself */
220 if (path[depth].p_bh)
221 return path[depth].p_bh->b_blocknr;
222 }
223
224 /* OK. use inode's group */
225 return ext4_inode_to_goal_block(inode);
226}
227
228/*
229 * Allocation for a meta data block
230 */
231static ext4_fsblk_t
232ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
233 struct ext4_ext_path *path,
234 struct ext4_extent *ex, int *err, unsigned int flags)
235{
236 ext4_fsblk_t goal, newblock;
237
238 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
239 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
240 NULL, err);
241 return newblock;
242}
243
244static inline int ext4_ext_space_block(struct inode *inode, int check)
245{
246 int size;
247
248 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
249 / sizeof(struct ext4_extent);
250#ifdef AGGRESSIVE_TEST
251 if (!check && size > 6)
252 size = 6;
253#endif
254 return size;
255}
256
257static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
258{
259 int size;
260
261 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
262 / sizeof(struct ext4_extent_idx);
263#ifdef AGGRESSIVE_TEST
264 if (!check && size > 5)
265 size = 5;
266#endif
267 return size;
268}
269
270static inline int ext4_ext_space_root(struct inode *inode, int check)
271{
272 int size;
273
274 size = sizeof(EXT4_I(inode)->i_data);
275 size -= sizeof(struct ext4_extent_header);
276 size /= sizeof(struct ext4_extent);
277#ifdef AGGRESSIVE_TEST
278 if (!check && size > 3)
279 size = 3;
280#endif
281 return size;
282}
283
284static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
285{
286 int size;
287
288 size = sizeof(EXT4_I(inode)->i_data);
289 size -= sizeof(struct ext4_extent_header);
290 size /= sizeof(struct ext4_extent_idx);
291#ifdef AGGRESSIVE_TEST
292 if (!check && size > 4)
293 size = 4;
294#endif
295 return size;
296}
297
298static inline int
299ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
300 struct ext4_ext_path **ppath, ext4_lblk_t lblk,
301 int nofail)
302{
303 struct ext4_ext_path *path = *ppath;
304 int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
305
306 return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ?
307 EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
308 EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO |
309 (nofail ? EXT4_GET_BLOCKS_METADATA_NOFAIL:0));
310}
311
312/*
313 * Calculate the number of metadata blocks needed
314 * to allocate @blocks
315 * Worse case is one block per extent
316 */
317int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
318{
319 struct ext4_inode_info *ei = EXT4_I(inode);
320 int idxs;
321
322 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
323 / sizeof(struct ext4_extent_idx));
324
325 /*
326 * If the new delayed allocation block is contiguous with the
327 * previous da block, it can share index blocks with the
328 * previous block, so we only need to allocate a new index
329 * block every idxs leaf blocks. At ldxs**2 blocks, we need
330 * an additional index block, and at ldxs**3 blocks, yet
331 * another index blocks.
332 */
333 if (ei->i_da_metadata_calc_len &&
334 ei->i_da_metadata_calc_last_lblock+1 == lblock) {
335 int num = 0;
336
337 if ((ei->i_da_metadata_calc_len % idxs) == 0)
338 num++;
339 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
340 num++;
341 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
342 num++;
343 ei->i_da_metadata_calc_len = 0;
344 } else
345 ei->i_da_metadata_calc_len++;
346 ei->i_da_metadata_calc_last_lblock++;
347 return num;
348 }
349
350 /*
351 * In the worst case we need a new set of index blocks at
352 * every level of the inode's extent tree.
353 */
354 ei->i_da_metadata_calc_len = 1;
355 ei->i_da_metadata_calc_last_lblock = lblock;
356 return ext_depth(inode) + 1;
357}
358
359static int
360ext4_ext_max_entries(struct inode *inode, int depth)
361{
362 int max;
363
364 if (depth == ext_depth(inode)) {
365 if (depth == 0)
366 max = ext4_ext_space_root(inode, 1);
367 else
368 max = ext4_ext_space_root_idx(inode, 1);
369 } else {
370 if (depth == 0)
371 max = ext4_ext_space_block(inode, 1);
372 else
373 max = ext4_ext_space_block_idx(inode, 1);
374 }
375
376 return max;
377}
378
379static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
380{
381 ext4_fsblk_t block = ext4_ext_pblock(ext);
382 int len = ext4_ext_get_actual_len(ext);
383 ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
384
385 /*
386 * We allow neither:
387 * - zero length
388 * - overflow/wrap-around
389 */
390 if (lblock + len <= lblock)
391 return 0;
392 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
393}
394
395static int ext4_valid_extent_idx(struct inode *inode,
396 struct ext4_extent_idx *ext_idx)
397{
398 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
399
400 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
401}
402
403static int ext4_valid_extent_entries(struct inode *inode,
404 struct ext4_extent_header *eh,
405 int depth)
406{
407 unsigned short entries;
408 if (eh->eh_entries == 0)
409 return 1;
410
411 entries = le16_to_cpu(eh->eh_entries);
412
413 if (depth == 0) {
414 /* leaf entries */
415 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
416 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
417 ext4_fsblk_t pblock = 0;
418 ext4_lblk_t lblock = 0;
419 ext4_lblk_t prev = 0;
420 int len = 0;
421 while (entries) {
422 if (!ext4_valid_extent(inode, ext))
423 return 0;
424
425 /* Check for overlapping extents */
426 lblock = le32_to_cpu(ext->ee_block);
427 len = ext4_ext_get_actual_len(ext);
428 if ((lblock <= prev) && prev) {
429 pblock = ext4_ext_pblock(ext);
430 es->s_last_error_block = cpu_to_le64(pblock);
431 return 0;
432 }
433 ext++;
434 entries--;
435 prev = lblock + len - 1;
436 }
437 } else {
438 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
439 while (entries) {
440 if (!ext4_valid_extent_idx(inode, ext_idx))
441 return 0;
442 ext_idx++;
443 entries--;
444 }
445 }
446 return 1;
447}
448
449static int __ext4_ext_check(const char *function, unsigned int line,
450 struct inode *inode, struct ext4_extent_header *eh,
451 int depth, ext4_fsblk_t pblk)
452{
453 const char *error_msg;
454 int max = 0, err = -EFSCORRUPTED;
455
456 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
457 error_msg = "invalid magic";
458 goto corrupted;
459 }
460 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
461 error_msg = "unexpected eh_depth";
462 goto corrupted;
463 }
464 if (unlikely(eh->eh_max == 0)) {
465 error_msg = "invalid eh_max";
466 goto corrupted;
467 }
468 max = ext4_ext_max_entries(inode, depth);
469 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
470 error_msg = "too large eh_max";
471 goto corrupted;
472 }
473 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
474 error_msg = "invalid eh_entries";
475 goto corrupted;
476 }
477 if (!ext4_valid_extent_entries(inode, eh, depth)) {
478 error_msg = "invalid extent entries";
479 goto corrupted;
480 }
481 if (unlikely(depth > 32)) {
482 error_msg = "too large eh_depth";
483 goto corrupted;
484 }
485 /* Verify checksum on non-root extent tree nodes */
486 if (ext_depth(inode) != depth &&
487 !ext4_extent_block_csum_verify(inode, eh)) {
488 error_msg = "extent tree corrupted";
489 err = -EFSBADCRC;
490 goto corrupted;
491 }
492 return 0;
493
494corrupted:
495 ext4_error_inode(inode, function, line, 0,
496 "pblk %llu bad header/extent: %s - magic %x, "
497 "entries %u, max %u(%u), depth %u(%u)",
498 (unsigned long long) pblk, error_msg,
499 le16_to_cpu(eh->eh_magic),
500 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
501 max, le16_to_cpu(eh->eh_depth), depth);
502 return err;
503}
504
505#define ext4_ext_check(inode, eh, depth, pblk) \
506 __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk))
507
508int ext4_ext_check_inode(struct inode *inode)
509{
510 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
511}
512
513static struct buffer_head *
514__read_extent_tree_block(const char *function, unsigned int line,
515 struct inode *inode, ext4_fsblk_t pblk, int depth,
516 int flags)
517{
518 struct buffer_head *bh;
519 int err;
520
521 bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
522 if (unlikely(!bh))
523 return ERR_PTR(-ENOMEM);
524
525 if (!bh_uptodate_or_lock(bh)) {
526 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
527 err = bh_submit_read(bh);
528 if (err < 0)
529 goto errout;
530 }
531 if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
532 return bh;
533 err = __ext4_ext_check(function, line, inode,
534 ext_block_hdr(bh), depth, pblk);
535 if (err)
536 goto errout;
537 set_buffer_verified(bh);
538 /*
539 * If this is a leaf block, cache all of its entries
540 */
541 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
542 struct ext4_extent_header *eh = ext_block_hdr(bh);
543 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
544 ext4_lblk_t prev = 0;
545 int i;
546
547 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
548 unsigned int status = EXTENT_STATUS_WRITTEN;
549 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
550 int len = ext4_ext_get_actual_len(ex);
551
552 if (prev && (prev != lblk))
553 ext4_es_cache_extent(inode, prev,
554 lblk - prev, ~0,
555 EXTENT_STATUS_HOLE);
556
557 if (ext4_ext_is_unwritten(ex))
558 status = EXTENT_STATUS_UNWRITTEN;
559 ext4_es_cache_extent(inode, lblk, len,
560 ext4_ext_pblock(ex), status);
561 prev = lblk + len;
562 }
563 }
564 return bh;
565errout:
566 put_bh(bh);
567 return ERR_PTR(err);
568
569}
570
571#define read_extent_tree_block(inode, pblk, depth, flags) \
572 __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \
573 (depth), (flags))
574
575/*
576 * This function is called to cache a file's extent information in the
577 * extent status tree
578 */
579int ext4_ext_precache(struct inode *inode)
580{
581 struct ext4_inode_info *ei = EXT4_I(inode);
582 struct ext4_ext_path *path = NULL;
583 struct buffer_head *bh;
584 int i = 0, depth, ret = 0;
585
586 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
587 return 0; /* not an extent-mapped inode */
588
589 down_read(&ei->i_data_sem);
590 depth = ext_depth(inode);
591
592 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
593 GFP_NOFS);
594 if (path == NULL) {
595 up_read(&ei->i_data_sem);
596 return -ENOMEM;
597 }
598
599 /* Don't cache anything if there are no external extent blocks */
600 if (depth == 0)
601 goto out;
602 path[0].p_hdr = ext_inode_hdr(inode);
603 ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
604 if (ret)
605 goto out;
606 path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
607 while (i >= 0) {
608 /*
609 * If this is a leaf block or we've reached the end of
610 * the index block, go up
611 */
612 if ((i == depth) ||
613 path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
614 brelse(path[i].p_bh);
615 path[i].p_bh = NULL;
616 i--;
617 continue;
618 }
619 bh = read_extent_tree_block(inode,
620 ext4_idx_pblock(path[i].p_idx++),
621 depth - i - 1,
622 EXT4_EX_FORCE_CACHE);
623 if (IS_ERR(bh)) {
624 ret = PTR_ERR(bh);
625 break;
626 }
627 i++;
628 path[i].p_bh = bh;
629 path[i].p_hdr = ext_block_hdr(bh);
630 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
631 }
632 ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
633out:
634 up_read(&ei->i_data_sem);
635 ext4_ext_drop_refs(path);
636 kfree(path);
637 return ret;
638}
639
640#ifdef EXT_DEBUG
641static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
642{
643 int k, l = path->p_depth;
644
645 ext_debug("path:");
646 for (k = 0; k <= l; k++, path++) {
647 if (path->p_idx) {
648 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
649 ext4_idx_pblock(path->p_idx));
650 } else if (path->p_ext) {
651 ext_debug(" %d:[%d]%d:%llu ",
652 le32_to_cpu(path->p_ext->ee_block),
653 ext4_ext_is_unwritten(path->p_ext),
654 ext4_ext_get_actual_len(path->p_ext),
655 ext4_ext_pblock(path->p_ext));
656 } else
657 ext_debug(" []");
658 }
659 ext_debug("\n");
660}
661
662static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
663{
664 int depth = ext_depth(inode);
665 struct ext4_extent_header *eh;
666 struct ext4_extent *ex;
667 int i;
668
669 if (!path)
670 return;
671
672 eh = path[depth].p_hdr;
673 ex = EXT_FIRST_EXTENT(eh);
674
675 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
676
677 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
678 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
679 ext4_ext_is_unwritten(ex),
680 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
681 }
682 ext_debug("\n");
683}
684
685static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
686 ext4_fsblk_t newblock, int level)
687{
688 int depth = ext_depth(inode);
689 struct ext4_extent *ex;
690
691 if (depth != level) {
692 struct ext4_extent_idx *idx;
693 idx = path[level].p_idx;
694 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
695 ext_debug("%d: move %d:%llu in new index %llu\n", level,
696 le32_to_cpu(idx->ei_block),
697 ext4_idx_pblock(idx),
698 newblock);
699 idx++;
700 }
701
702 return;
703 }
704
705 ex = path[depth].p_ext;
706 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
707 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
708 le32_to_cpu(ex->ee_block),
709 ext4_ext_pblock(ex),
710 ext4_ext_is_unwritten(ex),
711 ext4_ext_get_actual_len(ex),
712 newblock);
713 ex++;
714 }
715}
716
717#else
718#define ext4_ext_show_path(inode, path)
719#define ext4_ext_show_leaf(inode, path)
720#define ext4_ext_show_move(inode, path, newblock, level)
721#endif
722
723void ext4_ext_drop_refs(struct ext4_ext_path *path)
724{
725 int depth, i;
726
727 if (!path)
728 return;
729 depth = path->p_depth;
730 for (i = 0; i <= depth; i++, path++)
731 if (path->p_bh) {
732 brelse(path->p_bh);
733 path->p_bh = NULL;
734 }
735}
736
737/*
738 * ext4_ext_binsearch_idx:
739 * binary search for the closest index of the given block
740 * the header must be checked before calling this
741 */
742static void
743ext4_ext_binsearch_idx(struct inode *inode,
744 struct ext4_ext_path *path, ext4_lblk_t block)
745{
746 struct ext4_extent_header *eh = path->p_hdr;
747 struct ext4_extent_idx *r, *l, *m;
748
749
750 ext_debug("binsearch for %u(idx): ", block);
751
752 l = EXT_FIRST_INDEX(eh) + 1;
753 r = EXT_LAST_INDEX(eh);
754 while (l <= r) {
755 m = l + (r - l) / 2;
756 if (block < le32_to_cpu(m->ei_block))
757 r = m - 1;
758 else
759 l = m + 1;
760 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
761 m, le32_to_cpu(m->ei_block),
762 r, le32_to_cpu(r->ei_block));
763 }
764
765 path->p_idx = l - 1;
766 ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
767 ext4_idx_pblock(path->p_idx));
768
769#ifdef CHECK_BINSEARCH
770 {
771 struct ext4_extent_idx *chix, *ix;
772 int k;
773
774 chix = ix = EXT_FIRST_INDEX(eh);
775 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
776 if (k != 0 &&
777 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
778 printk(KERN_DEBUG "k=%d, ix=0x%p, "
779 "first=0x%p\n", k,
780 ix, EXT_FIRST_INDEX(eh));
781 printk(KERN_DEBUG "%u <= %u\n",
782 le32_to_cpu(ix->ei_block),
783 le32_to_cpu(ix[-1].ei_block));
784 }
785 BUG_ON(k && le32_to_cpu(ix->ei_block)
786 <= le32_to_cpu(ix[-1].ei_block));
787 if (block < le32_to_cpu(ix->ei_block))
788 break;
789 chix = ix;
790 }
791 BUG_ON(chix != path->p_idx);
792 }
793#endif
794
795}
796
797/*
798 * ext4_ext_binsearch:
799 * binary search for closest extent of the given block
800 * the header must be checked before calling this
801 */
802static void
803ext4_ext_binsearch(struct inode *inode,
804 struct ext4_ext_path *path, ext4_lblk_t block)
805{
806 struct ext4_extent_header *eh = path->p_hdr;
807 struct ext4_extent *r, *l, *m;
808
809 if (eh->eh_entries == 0) {
810 /*
811 * this leaf is empty:
812 * we get such a leaf in split/add case
813 */
814 return;
815 }
816
817 ext_debug("binsearch for %u: ", block);
818
819 l = EXT_FIRST_EXTENT(eh) + 1;
820 r = EXT_LAST_EXTENT(eh);
821
822 while (l <= r) {
823 m = l + (r - l) / 2;
824 if (block < le32_to_cpu(m->ee_block))
825 r = m - 1;
826 else
827 l = m + 1;
828 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
829 m, le32_to_cpu(m->ee_block),
830 r, le32_to_cpu(r->ee_block));
831 }
832
833 path->p_ext = l - 1;
834 ext_debug(" -> %d:%llu:[%d]%d ",
835 le32_to_cpu(path->p_ext->ee_block),
836 ext4_ext_pblock(path->p_ext),
837 ext4_ext_is_unwritten(path->p_ext),
838 ext4_ext_get_actual_len(path->p_ext));
839
840#ifdef CHECK_BINSEARCH
841 {
842 struct ext4_extent *chex, *ex;
843 int k;
844
845 chex = ex = EXT_FIRST_EXTENT(eh);
846 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
847 BUG_ON(k && le32_to_cpu(ex->ee_block)
848 <= le32_to_cpu(ex[-1].ee_block));
849 if (block < le32_to_cpu(ex->ee_block))
850 break;
851 chex = ex;
852 }
853 BUG_ON(chex != path->p_ext);
854 }
855#endif
856
857}
858
859int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
860{
861 struct ext4_extent_header *eh;
862
863 eh = ext_inode_hdr(inode);
864 eh->eh_depth = 0;
865 eh->eh_entries = 0;
866 eh->eh_magic = EXT4_EXT_MAGIC;
867 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
868 ext4_mark_inode_dirty(handle, inode);
869 return 0;
870}
871
872struct ext4_ext_path *
873ext4_find_extent(struct inode *inode, ext4_lblk_t block,
874 struct ext4_ext_path **orig_path, int flags)
875{
876 struct ext4_extent_header *eh;
877 struct buffer_head *bh;
878 struct ext4_ext_path *path = orig_path ? *orig_path : NULL;
879 short int depth, i, ppos = 0;
880 int ret;
881
882 eh = ext_inode_hdr(inode);
883 depth = ext_depth(inode);
884
885 if (path) {
886 ext4_ext_drop_refs(path);
887 if (depth > path[0].p_maxdepth) {
888 kfree(path);
889 *orig_path = path = NULL;
890 }
891 }
892 if (!path) {
893 /* account possible depth increase */
894 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
895 GFP_NOFS);
896 if (unlikely(!path))
897 return ERR_PTR(-ENOMEM);
898 path[0].p_maxdepth = depth + 1;
899 }
900 path[0].p_hdr = eh;
901 path[0].p_bh = NULL;
902
903 i = depth;
904 /* walk through the tree */
905 while (i) {
906 ext_debug("depth %d: num %d, max %d\n",
907 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
908
909 ext4_ext_binsearch_idx(inode, path + ppos, block);
910 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
911 path[ppos].p_depth = i;
912 path[ppos].p_ext = NULL;
913
914 bh = read_extent_tree_block(inode, path[ppos].p_block, --i,
915 flags);
916 if (IS_ERR(bh)) {
917 ret = PTR_ERR(bh);
918 goto err;
919 }
920
921 eh = ext_block_hdr(bh);
922 ppos++;
923 path[ppos].p_bh = bh;
924 path[ppos].p_hdr = eh;
925 }
926
927 path[ppos].p_depth = i;
928 path[ppos].p_ext = NULL;
929 path[ppos].p_idx = NULL;
930
931 /* find extent */
932 ext4_ext_binsearch(inode, path + ppos, block);
933 /* if not an empty leaf */
934 if (path[ppos].p_ext)
935 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
936
937 ext4_ext_show_path(inode, path);
938
939 return path;
940
941err:
942 ext4_ext_drop_refs(path);
943 kfree(path);
944 if (orig_path)
945 *orig_path = NULL;
946 return ERR_PTR(ret);
947}
948
949/*
950 * ext4_ext_insert_index:
951 * insert new index [@logical;@ptr] into the block at @curp;
952 * check where to insert: before @curp or after @curp
953 */
954static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
955 struct ext4_ext_path *curp,
956 int logical, ext4_fsblk_t ptr)
957{
958 struct ext4_extent_idx *ix;
959 int len, err;
960
961 err = ext4_ext_get_access(handle, inode, curp);
962 if (err)
963 return err;
964
965 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
966 EXT4_ERROR_INODE(inode,
967 "logical %d == ei_block %d!",
968 logical, le32_to_cpu(curp->p_idx->ei_block));
969 return -EFSCORRUPTED;
970 }
971
972 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
973 >= le16_to_cpu(curp->p_hdr->eh_max))) {
974 EXT4_ERROR_INODE(inode,
975 "eh_entries %d >= eh_max %d!",
976 le16_to_cpu(curp->p_hdr->eh_entries),
977 le16_to_cpu(curp->p_hdr->eh_max));
978 return -EFSCORRUPTED;
979 }
980
981 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
982 /* insert after */
983 ext_debug("insert new index %d after: %llu\n", logical, ptr);
984 ix = curp->p_idx + 1;
985 } else {
986 /* insert before */
987 ext_debug("insert new index %d before: %llu\n", logical, ptr);
988 ix = curp->p_idx;
989 }
990
991 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
992 BUG_ON(len < 0);
993 if (len > 0) {
994 ext_debug("insert new index %d: "
995 "move %d indices from 0x%p to 0x%p\n",
996 logical, len, ix, ix + 1);
997 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
998 }
999
1000 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
1001 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
1002 return -EFSCORRUPTED;
1003 }
1004
1005 ix->ei_block = cpu_to_le32(logical);
1006 ext4_idx_store_pblock(ix, ptr);
1007 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
1008
1009 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
1010 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
1011 return -EFSCORRUPTED;
1012 }
1013
1014 err = ext4_ext_dirty(handle, inode, curp);
1015 ext4_std_error(inode->i_sb, err);
1016
1017 return err;
1018}
1019
1020/*
1021 * ext4_ext_split:
1022 * inserts new subtree into the path, using free index entry
1023 * at depth @at:
1024 * - allocates all needed blocks (new leaf and all intermediate index blocks)
1025 * - makes decision where to split
1026 * - moves remaining extents and index entries (right to the split point)
1027 * into the newly allocated blocks
1028 * - initializes subtree
1029 */
1030static int ext4_ext_split(handle_t *handle, struct inode *inode,
1031 unsigned int flags,
1032 struct ext4_ext_path *path,
1033 struct ext4_extent *newext, int at)
1034{
1035 struct buffer_head *bh = NULL;
1036 int depth = ext_depth(inode);
1037 struct ext4_extent_header *neh;
1038 struct ext4_extent_idx *fidx;
1039 int i = at, k, m, a;
1040 ext4_fsblk_t newblock, oldblock;
1041 __le32 border;
1042 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1043 int err = 0;
1044
1045 /* make decision: where to split? */
1046 /* FIXME: now decision is simplest: at current extent */
1047
1048 /* if current leaf will be split, then we should use
1049 * border from split point */
1050 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1051 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1052 return -EFSCORRUPTED;
1053 }
1054 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1055 border = path[depth].p_ext[1].ee_block;
1056 ext_debug("leaf will be split."
1057 " next leaf starts at %d\n",
1058 le32_to_cpu(border));
1059 } else {
1060 border = newext->ee_block;
1061 ext_debug("leaf will be added."
1062 " next leaf starts at %d\n",
1063 le32_to_cpu(border));
1064 }
1065
1066 /*
1067 * If error occurs, then we break processing
1068 * and mark filesystem read-only. index won't
1069 * be inserted and tree will be in consistent
1070 * state. Next mount will repair buffers too.
1071 */
1072
1073 /*
1074 * Get array to track all allocated blocks.
1075 * We need this to handle errors and free blocks
1076 * upon them.
1077 */
1078 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
1079 if (!ablocks)
1080 return -ENOMEM;
1081
1082 /* allocate all needed blocks */
1083 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
1084 for (a = 0; a < depth - at; a++) {
1085 newblock = ext4_ext_new_meta_block(handle, inode, path,
1086 newext, &err, flags);
1087 if (newblock == 0)
1088 goto cleanup;
1089 ablocks[a] = newblock;
1090 }
1091
1092 /* initialize new leaf */
1093 newblock = ablocks[--a];
1094 if (unlikely(newblock == 0)) {
1095 EXT4_ERROR_INODE(inode, "newblock == 0!");
1096 err = -EFSCORRUPTED;
1097 goto cleanup;
1098 }
1099 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1100 if (unlikely(!bh)) {
1101 err = -ENOMEM;
1102 goto cleanup;
1103 }
1104 lock_buffer(bh);
1105
1106 err = ext4_journal_get_create_access(handle, bh);
1107 if (err)
1108 goto cleanup;
1109
1110 neh = ext_block_hdr(bh);
1111 neh->eh_entries = 0;
1112 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1113 neh->eh_magic = EXT4_EXT_MAGIC;
1114 neh->eh_depth = 0;
1115
1116 /* move remainder of path[depth] to the new leaf */
1117 if (unlikely(path[depth].p_hdr->eh_entries !=
1118 path[depth].p_hdr->eh_max)) {
1119 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1120 path[depth].p_hdr->eh_entries,
1121 path[depth].p_hdr->eh_max);
1122 err = -EFSCORRUPTED;
1123 goto cleanup;
1124 }
1125 /* start copy from next extent */
1126 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1127 ext4_ext_show_move(inode, path, newblock, depth);
1128 if (m) {
1129 struct ext4_extent *ex;
1130 ex = EXT_FIRST_EXTENT(neh);
1131 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1132 le16_add_cpu(&neh->eh_entries, m);
1133 }
1134
1135 ext4_extent_block_csum_set(inode, neh);
1136 set_buffer_uptodate(bh);
1137 unlock_buffer(bh);
1138
1139 err = ext4_handle_dirty_metadata(handle, inode, bh);
1140 if (err)
1141 goto cleanup;
1142 brelse(bh);
1143 bh = NULL;
1144
1145 /* correct old leaf */
1146 if (m) {
1147 err = ext4_ext_get_access(handle, inode, path + depth);
1148 if (err)
1149 goto cleanup;
1150 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1151 err = ext4_ext_dirty(handle, inode, path + depth);
1152 if (err)
1153 goto cleanup;
1154
1155 }
1156
1157 /* create intermediate indexes */
1158 k = depth - at - 1;
1159 if (unlikely(k < 0)) {
1160 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1161 err = -EFSCORRUPTED;
1162 goto cleanup;
1163 }
1164 if (k)
1165 ext_debug("create %d intermediate indices\n", k);
1166 /* insert new index into current index block */
1167 /* current depth stored in i var */
1168 i = depth - 1;
1169 while (k--) {
1170 oldblock = newblock;
1171 newblock = ablocks[--a];
1172 bh = sb_getblk(inode->i_sb, newblock);
1173 if (unlikely(!bh)) {
1174 err = -ENOMEM;
1175 goto cleanup;
1176 }
1177 lock_buffer(bh);
1178
1179 err = ext4_journal_get_create_access(handle, bh);
1180 if (err)
1181 goto cleanup;
1182
1183 neh = ext_block_hdr(bh);
1184 neh->eh_entries = cpu_to_le16(1);
1185 neh->eh_magic = EXT4_EXT_MAGIC;
1186 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1187 neh->eh_depth = cpu_to_le16(depth - i);
1188 fidx = EXT_FIRST_INDEX(neh);
1189 fidx->ei_block = border;
1190 ext4_idx_store_pblock(fidx, oldblock);
1191
1192 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1193 i, newblock, le32_to_cpu(border), oldblock);
1194
1195 /* move remainder of path[i] to the new index block */
1196 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1197 EXT_LAST_INDEX(path[i].p_hdr))) {
1198 EXT4_ERROR_INODE(inode,
1199 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1200 le32_to_cpu(path[i].p_ext->ee_block));
1201 err = -EFSCORRUPTED;
1202 goto cleanup;
1203 }
1204 /* start copy indexes */
1205 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1206 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1207 EXT_MAX_INDEX(path[i].p_hdr));
1208 ext4_ext_show_move(inode, path, newblock, i);
1209 if (m) {
1210 memmove(++fidx, path[i].p_idx,
1211 sizeof(struct ext4_extent_idx) * m);
1212 le16_add_cpu(&neh->eh_entries, m);
1213 }
1214 ext4_extent_block_csum_set(inode, neh);
1215 set_buffer_uptodate(bh);
1216 unlock_buffer(bh);
1217
1218 err = ext4_handle_dirty_metadata(handle, inode, bh);
1219 if (err)
1220 goto cleanup;
1221 brelse(bh);
1222 bh = NULL;
1223
1224 /* correct old index */
1225 if (m) {
1226 err = ext4_ext_get_access(handle, inode, path + i);
1227 if (err)
1228 goto cleanup;
1229 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1230 err = ext4_ext_dirty(handle, inode, path + i);
1231 if (err)
1232 goto cleanup;
1233 }
1234
1235 i--;
1236 }
1237
1238 /* insert new index */
1239 err = ext4_ext_insert_index(handle, inode, path + at,
1240 le32_to_cpu(border), newblock);
1241
1242cleanup:
1243 if (bh) {
1244 if (buffer_locked(bh))
1245 unlock_buffer(bh);
1246 brelse(bh);
1247 }
1248
1249 if (err) {
1250 /* free all allocated blocks in error case */
1251 for (i = 0; i < depth; i++) {
1252 if (!ablocks[i])
1253 continue;
1254 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1255 EXT4_FREE_BLOCKS_METADATA);
1256 }
1257 }
1258 kfree(ablocks);
1259
1260 return err;
1261}
1262
1263/*
1264 * ext4_ext_grow_indepth:
1265 * implements tree growing procedure:
1266 * - allocates new block
1267 * - moves top-level data (index block or leaf) into the new block
1268 * - initializes new top-level, creating index that points to the
1269 * just created block
1270 */
1271static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1272 unsigned int flags)
1273{
1274 struct ext4_extent_header *neh;
1275 struct buffer_head *bh;
1276 ext4_fsblk_t newblock, goal = 0;
1277 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
1278 int err = 0;
1279
1280 /* Try to prepend new index to old one */
1281 if (ext_depth(inode))
1282 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
1283 if (goal > le32_to_cpu(es->s_first_data_block)) {
1284 flags |= EXT4_MB_HINT_TRY_GOAL;
1285 goal--;
1286 } else
1287 goal = ext4_inode_to_goal_block(inode);
1288 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
1289 NULL, &err);
1290 if (newblock == 0)
1291 return err;
1292
1293 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1294 if (unlikely(!bh))
1295 return -ENOMEM;
1296 lock_buffer(bh);
1297
1298 err = ext4_journal_get_create_access(handle, bh);
1299 if (err) {
1300 unlock_buffer(bh);
1301 goto out;
1302 }
1303
1304 /* move top-level index/leaf into new block */
1305 memmove(bh->b_data, EXT4_I(inode)->i_data,
1306 sizeof(EXT4_I(inode)->i_data));
1307
1308 /* set size of new block */
1309 neh = ext_block_hdr(bh);
1310 /* old root could have indexes or leaves
1311 * so calculate e_max right way */
1312 if (ext_depth(inode))
1313 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1314 else
1315 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1316 neh->eh_magic = EXT4_EXT_MAGIC;
1317 ext4_extent_block_csum_set(inode, neh);
1318 set_buffer_uptodate(bh);
1319 unlock_buffer(bh);
1320
1321 err = ext4_handle_dirty_metadata(handle, inode, bh);
1322 if (err)
1323 goto out;
1324
1325 /* Update top-level index: num,max,pointer */
1326 neh = ext_inode_hdr(inode);
1327 neh->eh_entries = cpu_to_le16(1);
1328 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1329 if (neh->eh_depth == 0) {
1330 /* Root extent block becomes index block */
1331 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1332 EXT_FIRST_INDEX(neh)->ei_block =
1333 EXT_FIRST_EXTENT(neh)->ee_block;
1334 }
1335 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1336 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1337 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1338 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1339
1340 le16_add_cpu(&neh->eh_depth, 1);
1341 ext4_mark_inode_dirty(handle, inode);
1342out:
1343 brelse(bh);
1344
1345 return err;
1346}
1347
1348/*
1349 * ext4_ext_create_new_leaf:
1350 * finds empty index and adds new leaf.
1351 * if no free index is found, then it requests in-depth growing.
1352 */
1353static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1354 unsigned int mb_flags,
1355 unsigned int gb_flags,
1356 struct ext4_ext_path **ppath,
1357 struct ext4_extent *newext)
1358{
1359 struct ext4_ext_path *path = *ppath;
1360 struct ext4_ext_path *curp;
1361 int depth, i, err = 0;
1362
1363repeat:
1364 i = depth = ext_depth(inode);
1365
1366 /* walk up to the tree and look for free index entry */
1367 curp = path + depth;
1368 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1369 i--;
1370 curp--;
1371 }
1372
1373 /* we use already allocated block for index block,
1374 * so subsequent data blocks should be contiguous */
1375 if (EXT_HAS_FREE_INDEX(curp)) {
1376 /* if we found index with free entry, then use that
1377 * entry: create all needed subtree and add new leaf */
1378 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
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 } else {
1389 /* tree is full, time to grow in depth */
1390 err = ext4_ext_grow_indepth(handle, inode, mb_flags);
1391 if (err)
1392 goto out;
1393
1394 /* refill path */
1395 path = ext4_find_extent(inode,
1396 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1397 ppath, gb_flags);
1398 if (IS_ERR(path)) {
1399 err = PTR_ERR(path);
1400 goto out;
1401 }
1402
1403 /*
1404 * only first (depth 0 -> 1) produces free space;
1405 * in all other cases we have to split the grown tree
1406 */
1407 depth = ext_depth(inode);
1408 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1409 /* now we need to split */
1410 goto repeat;
1411 }
1412 }
1413
1414out:
1415 return err;
1416}
1417
1418/*
1419 * search the closest allocated block to the left for *logical
1420 * and returns it at @logical + it's physical address at @phys
1421 * if *logical is the smallest allocated block, the function
1422 * returns 0 at @phys
1423 * return value contains 0 (success) or error code
1424 */
1425static int ext4_ext_search_left(struct inode *inode,
1426 struct ext4_ext_path *path,
1427 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1428{
1429 struct ext4_extent_idx *ix;
1430 struct ext4_extent *ex;
1431 int depth, ee_len;
1432
1433 if (unlikely(path == NULL)) {
1434 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1435 return -EFSCORRUPTED;
1436 }
1437 depth = path->p_depth;
1438 *phys = 0;
1439
1440 if (depth == 0 && path->p_ext == NULL)
1441 return 0;
1442
1443 /* usually extent in the path covers blocks smaller
1444 * then *logical, but it can be that extent is the
1445 * first one in the file */
1446
1447 ex = path[depth].p_ext;
1448 ee_len = ext4_ext_get_actual_len(ex);
1449 if (*logical < le32_to_cpu(ex->ee_block)) {
1450 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1451 EXT4_ERROR_INODE(inode,
1452 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1453 *logical, le32_to_cpu(ex->ee_block));
1454 return -EFSCORRUPTED;
1455 }
1456 while (--depth >= 0) {
1457 ix = path[depth].p_idx;
1458 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1459 EXT4_ERROR_INODE(inode,
1460 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1461 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1462 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1463 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1464 depth);
1465 return -EFSCORRUPTED;
1466 }
1467 }
1468 return 0;
1469 }
1470
1471 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1472 EXT4_ERROR_INODE(inode,
1473 "logical %d < ee_block %d + ee_len %d!",
1474 *logical, le32_to_cpu(ex->ee_block), ee_len);
1475 return -EFSCORRUPTED;
1476 }
1477
1478 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1479 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1480 return 0;
1481}
1482
1483/*
1484 * search the closest allocated block to the right for *logical
1485 * and returns it at @logical + it's physical address at @phys
1486 * if *logical is the largest allocated block, the function
1487 * returns 0 at @phys
1488 * return value contains 0 (success) or error code
1489 */
1490static int ext4_ext_search_right(struct inode *inode,
1491 struct ext4_ext_path *path,
1492 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1493 struct ext4_extent **ret_ex)
1494{
1495 struct buffer_head *bh = NULL;
1496 struct ext4_extent_header *eh;
1497 struct ext4_extent_idx *ix;
1498 struct ext4_extent *ex;
1499 ext4_fsblk_t block;
1500 int depth; /* Note, NOT eh_depth; depth from top of tree */
1501 int ee_len;
1502
1503 if (unlikely(path == NULL)) {
1504 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1505 return -EFSCORRUPTED;
1506 }
1507 depth = path->p_depth;
1508 *phys = 0;
1509
1510 if (depth == 0 && path->p_ext == NULL)
1511 return 0;
1512
1513 /* usually extent in the path covers blocks smaller
1514 * then *logical, but it can be that extent is the
1515 * first one in the file */
1516
1517 ex = path[depth].p_ext;
1518 ee_len = ext4_ext_get_actual_len(ex);
1519 if (*logical < le32_to_cpu(ex->ee_block)) {
1520 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1521 EXT4_ERROR_INODE(inode,
1522 "first_extent(path[%d].p_hdr) != ex",
1523 depth);
1524 return -EFSCORRUPTED;
1525 }
1526 while (--depth >= 0) {
1527 ix = path[depth].p_idx;
1528 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1529 EXT4_ERROR_INODE(inode,
1530 "ix != EXT_FIRST_INDEX *logical %d!",
1531 *logical);
1532 return -EFSCORRUPTED;
1533 }
1534 }
1535 goto found_extent;
1536 }
1537
1538 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1539 EXT4_ERROR_INODE(inode,
1540 "logical %d < ee_block %d + ee_len %d!",
1541 *logical, le32_to_cpu(ex->ee_block), ee_len);
1542 return -EFSCORRUPTED;
1543 }
1544
1545 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1546 /* next allocated block in this leaf */
1547 ex++;
1548 goto found_extent;
1549 }
1550
1551 /* go up and search for index to the right */
1552 while (--depth >= 0) {
1553 ix = path[depth].p_idx;
1554 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1555 goto got_index;
1556 }
1557
1558 /* we've gone up to the root and found no index to the right */
1559 return 0;
1560
1561got_index:
1562 /* we've found index to the right, let's
1563 * follow it and find the closest allocated
1564 * block to the right */
1565 ix++;
1566 block = ext4_idx_pblock(ix);
1567 while (++depth < path->p_depth) {
1568 /* subtract from p_depth to get proper eh_depth */
1569 bh = read_extent_tree_block(inode, block,
1570 path->p_depth - depth, 0);
1571 if (IS_ERR(bh))
1572 return PTR_ERR(bh);
1573 eh = ext_block_hdr(bh);
1574 ix = EXT_FIRST_INDEX(eh);
1575 block = ext4_idx_pblock(ix);
1576 put_bh(bh);
1577 }
1578
1579 bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0);
1580 if (IS_ERR(bh))
1581 return PTR_ERR(bh);
1582 eh = ext_block_hdr(bh);
1583 ex = EXT_FIRST_EXTENT(eh);
1584found_extent:
1585 *logical = le32_to_cpu(ex->ee_block);
1586 *phys = ext4_ext_pblock(ex);
1587 *ret_ex = ex;
1588 if (bh)
1589 put_bh(bh);
1590 return 0;
1591}
1592
1593/*
1594 * ext4_ext_next_allocated_block:
1595 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1596 * NOTE: it considers block number from index entry as
1597 * allocated block. Thus, index entries have to be consistent
1598 * with leaves.
1599 */
1600ext4_lblk_t
1601ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1602{
1603 int depth;
1604
1605 BUG_ON(path == NULL);
1606 depth = path->p_depth;
1607
1608 if (depth == 0 && path->p_ext == NULL)
1609 return EXT_MAX_BLOCKS;
1610
1611 while (depth >= 0) {
1612 if (depth == path->p_depth) {
1613 /* leaf */
1614 if (path[depth].p_ext &&
1615 path[depth].p_ext !=
1616 EXT_LAST_EXTENT(path[depth].p_hdr))
1617 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1618 } else {
1619 /* index */
1620 if (path[depth].p_idx !=
1621 EXT_LAST_INDEX(path[depth].p_hdr))
1622 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1623 }
1624 depth--;
1625 }
1626
1627 return EXT_MAX_BLOCKS;
1628}
1629
1630/*
1631 * ext4_ext_next_leaf_block:
1632 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1633 */
1634static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1635{
1636 int depth;
1637
1638 BUG_ON(path == NULL);
1639 depth = path->p_depth;
1640
1641 /* zero-tree has no leaf blocks at all */
1642 if (depth == 0)
1643 return EXT_MAX_BLOCKS;
1644
1645 /* go to index block */
1646 depth--;
1647
1648 while (depth >= 0) {
1649 if (path[depth].p_idx !=
1650 EXT_LAST_INDEX(path[depth].p_hdr))
1651 return (ext4_lblk_t)
1652 le32_to_cpu(path[depth].p_idx[1].ei_block);
1653 depth--;
1654 }
1655
1656 return EXT_MAX_BLOCKS;
1657}
1658
1659/*
1660 * ext4_ext_correct_indexes:
1661 * if leaf gets modified and modified extent is first in the leaf,
1662 * then we have to correct all indexes above.
1663 * TODO: do we need to correct tree in all cases?
1664 */
1665static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1666 struct ext4_ext_path *path)
1667{
1668 struct ext4_extent_header *eh;
1669 int depth = ext_depth(inode);
1670 struct ext4_extent *ex;
1671 __le32 border;
1672 int k, err = 0;
1673
1674 eh = path[depth].p_hdr;
1675 ex = path[depth].p_ext;
1676
1677 if (unlikely(ex == NULL || eh == NULL)) {
1678 EXT4_ERROR_INODE(inode,
1679 "ex %p == NULL or eh %p == NULL", ex, eh);
1680 return -EFSCORRUPTED;
1681 }
1682
1683 if (depth == 0) {
1684 /* there is no tree at all */
1685 return 0;
1686 }
1687
1688 if (ex != EXT_FIRST_EXTENT(eh)) {
1689 /* we correct tree if first leaf got modified only */
1690 return 0;
1691 }
1692
1693 /*
1694 * TODO: we need correction if border is smaller than current one
1695 */
1696 k = depth - 1;
1697 border = path[depth].p_ext->ee_block;
1698 err = ext4_ext_get_access(handle, inode, path + k);
1699 if (err)
1700 return err;
1701 path[k].p_idx->ei_block = border;
1702 err = ext4_ext_dirty(handle, inode, path + k);
1703 if (err)
1704 return err;
1705
1706 while (k--) {
1707 /* change all left-side indexes */
1708 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1709 break;
1710 err = ext4_ext_get_access(handle, inode, path + k);
1711 if (err)
1712 break;
1713 path[k].p_idx->ei_block = border;
1714 err = ext4_ext_dirty(handle, inode, path + k);
1715 if (err)
1716 break;
1717 }
1718
1719 return err;
1720}
1721
1722int
1723ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1724 struct ext4_extent *ex2)
1725{
1726 unsigned short ext1_ee_len, ext2_ee_len;
1727
1728 if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
1729 return 0;
1730
1731 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1732 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1733
1734 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1735 le32_to_cpu(ex2->ee_block))
1736 return 0;
1737
1738 /*
1739 * To allow future support for preallocated extents to be added
1740 * as an RO_COMPAT feature, refuse to merge to extents if
1741 * this can result in the top bit of ee_len being set.
1742 */
1743 if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1744 return 0;
1745 /*
1746 * The check for IO to unwritten extent is somewhat racy as we
1747 * increment i_unwritten / set EXT4_STATE_DIO_UNWRITTEN only after
1748 * dropping i_data_sem. But reserved blocks should save us in that
1749 * case.
1750 */
1751 if (ext4_ext_is_unwritten(ex1) &&
1752 (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) ||
1753 atomic_read(&EXT4_I(inode)->i_unwritten) ||
1754 (ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)))
1755 return 0;
1756#ifdef AGGRESSIVE_TEST
1757 if (ext1_ee_len >= 4)
1758 return 0;
1759#endif
1760
1761 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1762 return 1;
1763 return 0;
1764}
1765
1766/*
1767 * This function tries to merge the "ex" extent to the next extent in the tree.
1768 * It always tries to merge towards right. If you want to merge towards
1769 * left, pass "ex - 1" as argument instead of "ex".
1770 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1771 * 1 if they got merged.
1772 */
1773static int ext4_ext_try_to_merge_right(struct inode *inode,
1774 struct ext4_ext_path *path,
1775 struct ext4_extent *ex)
1776{
1777 struct ext4_extent_header *eh;
1778 unsigned int depth, len;
1779 int merge_done = 0, unwritten;
1780
1781 depth = ext_depth(inode);
1782 BUG_ON(path[depth].p_hdr == NULL);
1783 eh = path[depth].p_hdr;
1784
1785 while (ex < EXT_LAST_EXTENT(eh)) {
1786 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1787 break;
1788 /* merge with next extent! */
1789 unwritten = ext4_ext_is_unwritten(ex);
1790 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1791 + ext4_ext_get_actual_len(ex + 1));
1792 if (unwritten)
1793 ext4_ext_mark_unwritten(ex);
1794
1795 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1796 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1797 * sizeof(struct ext4_extent);
1798 memmove(ex + 1, ex + 2, len);
1799 }
1800 le16_add_cpu(&eh->eh_entries, -1);
1801 merge_done = 1;
1802 WARN_ON(eh->eh_entries == 0);
1803 if (!eh->eh_entries)
1804 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1805 }
1806
1807 return merge_done;
1808}
1809
1810/*
1811 * This function does a very simple check to see if we can collapse
1812 * an extent tree with a single extent tree leaf block into the inode.
1813 */
1814static void ext4_ext_try_to_merge_up(handle_t *handle,
1815 struct inode *inode,
1816 struct ext4_ext_path *path)
1817{
1818 size_t s;
1819 unsigned max_root = ext4_ext_space_root(inode, 0);
1820 ext4_fsblk_t blk;
1821
1822 if ((path[0].p_depth != 1) ||
1823 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1824 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1825 return;
1826
1827 /*
1828 * We need to modify the block allocation bitmap and the block
1829 * group descriptor to release the extent tree block. If we
1830 * can't get the journal credits, give up.
1831 */
1832 if (ext4_journal_extend(handle, 2))
1833 return;
1834
1835 /*
1836 * Copy the extent data up to the inode
1837 */
1838 blk = ext4_idx_pblock(path[0].p_idx);
1839 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1840 sizeof(struct ext4_extent_idx);
1841 s += sizeof(struct ext4_extent_header);
1842
1843 path[1].p_maxdepth = path[0].p_maxdepth;
1844 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1845 path[0].p_depth = 0;
1846 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1847 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1848 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1849
1850 brelse(path[1].p_bh);
1851 ext4_free_blocks(handle, inode, NULL, blk, 1,
1852 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1853}
1854
1855/*
1856 * This function tries to merge the @ex extent to neighbours in the tree.
1857 * return 1 if merge left else 0.
1858 */
1859static void ext4_ext_try_to_merge(handle_t *handle,
1860 struct inode *inode,
1861 struct ext4_ext_path *path,
1862 struct ext4_extent *ex) {
1863 struct ext4_extent_header *eh;
1864 unsigned int depth;
1865 int merge_done = 0;
1866
1867 depth = ext_depth(inode);
1868 BUG_ON(path[depth].p_hdr == NULL);
1869 eh = path[depth].p_hdr;
1870
1871 if (ex > EXT_FIRST_EXTENT(eh))
1872 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1873
1874 if (!merge_done)
1875 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1876
1877 ext4_ext_try_to_merge_up(handle, inode, path);
1878}
1879
1880/*
1881 * check if a portion of the "newext" extent overlaps with an
1882 * existing extent.
1883 *
1884 * If there is an overlap discovered, it updates the length of the newext
1885 * such that there will be no overlap, and then returns 1.
1886 * If there is no overlap found, it returns 0.
1887 */
1888static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1889 struct inode *inode,
1890 struct ext4_extent *newext,
1891 struct ext4_ext_path *path)
1892{
1893 ext4_lblk_t b1, b2;
1894 unsigned int depth, len1;
1895 unsigned int ret = 0;
1896
1897 b1 = le32_to_cpu(newext->ee_block);
1898 len1 = ext4_ext_get_actual_len(newext);
1899 depth = ext_depth(inode);
1900 if (!path[depth].p_ext)
1901 goto out;
1902 b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
1903
1904 /*
1905 * get the next allocated block if the extent in the path
1906 * is before the requested block(s)
1907 */
1908 if (b2 < b1) {
1909 b2 = ext4_ext_next_allocated_block(path);
1910 if (b2 == EXT_MAX_BLOCKS)
1911 goto out;
1912 b2 = EXT4_LBLK_CMASK(sbi, b2);
1913 }
1914
1915 /* check for wrap through zero on extent logical start block*/
1916 if (b1 + len1 < b1) {
1917 len1 = EXT_MAX_BLOCKS - b1;
1918 newext->ee_len = cpu_to_le16(len1);
1919 ret = 1;
1920 }
1921
1922 /* check for overlap */
1923 if (b1 + len1 > b2) {
1924 newext->ee_len = cpu_to_le16(b2 - b1);
1925 ret = 1;
1926 }
1927out:
1928 return ret;
1929}
1930
1931/*
1932 * ext4_ext_insert_extent:
1933 * tries to merge requsted extent into the existing extent or
1934 * inserts requested extent as new one into the tree,
1935 * creating new leaf in the no-space case.
1936 */
1937int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1938 struct ext4_ext_path **ppath,
1939 struct ext4_extent *newext, int gb_flags)
1940{
1941 struct ext4_ext_path *path = *ppath;
1942 struct ext4_extent_header *eh;
1943 struct ext4_extent *ex, *fex;
1944 struct ext4_extent *nearex; /* nearest extent */
1945 struct ext4_ext_path *npath = NULL;
1946 int depth, len, err;
1947 ext4_lblk_t next;
1948 int mb_flags = 0, unwritten;
1949
1950 if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1951 mb_flags |= EXT4_MB_DELALLOC_RESERVED;
1952 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1953 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1954 return -EFSCORRUPTED;
1955 }
1956 depth = ext_depth(inode);
1957 ex = path[depth].p_ext;
1958 eh = path[depth].p_hdr;
1959 if (unlikely(path[depth].p_hdr == NULL)) {
1960 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1961 return -EFSCORRUPTED;
1962 }
1963
1964 /* try to insert block into found extent and return */
1965 if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
1966
1967 /*
1968 * Try to see whether we should rather test the extent on
1969 * right from ex, or from the left of ex. This is because
1970 * ext4_find_extent() can return either extent on the
1971 * left, or on the right from the searched position. This
1972 * will make merging more effective.
1973 */
1974 if (ex < EXT_LAST_EXTENT(eh) &&
1975 (le32_to_cpu(ex->ee_block) +
1976 ext4_ext_get_actual_len(ex) <
1977 le32_to_cpu(newext->ee_block))) {
1978 ex += 1;
1979 goto prepend;
1980 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
1981 (le32_to_cpu(newext->ee_block) +
1982 ext4_ext_get_actual_len(newext) <
1983 le32_to_cpu(ex->ee_block)))
1984 ex -= 1;
1985
1986 /* Try to append newex to the ex */
1987 if (ext4_can_extents_be_merged(inode, ex, newext)) {
1988 ext_debug("append [%d]%d block to %u:[%d]%d"
1989 "(from %llu)\n",
1990 ext4_ext_is_unwritten(newext),
1991 ext4_ext_get_actual_len(newext),
1992 le32_to_cpu(ex->ee_block),
1993 ext4_ext_is_unwritten(ex),
1994 ext4_ext_get_actual_len(ex),
1995 ext4_ext_pblock(ex));
1996 err = ext4_ext_get_access(handle, inode,
1997 path + depth);
1998 if (err)
1999 return err;
2000 unwritten = ext4_ext_is_unwritten(ex);
2001 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2002 + ext4_ext_get_actual_len(newext));
2003 if (unwritten)
2004 ext4_ext_mark_unwritten(ex);
2005 eh = path[depth].p_hdr;
2006 nearex = ex;
2007 goto merge;
2008 }
2009
2010prepend:
2011 /* Try to prepend newex to the ex */
2012 if (ext4_can_extents_be_merged(inode, newext, ex)) {
2013 ext_debug("prepend %u[%d]%d block to %u:[%d]%d"
2014 "(from %llu)\n",
2015 le32_to_cpu(newext->ee_block),
2016 ext4_ext_is_unwritten(newext),
2017 ext4_ext_get_actual_len(newext),
2018 le32_to_cpu(ex->ee_block),
2019 ext4_ext_is_unwritten(ex),
2020 ext4_ext_get_actual_len(ex),
2021 ext4_ext_pblock(ex));
2022 err = ext4_ext_get_access(handle, inode,
2023 path + depth);
2024 if (err)
2025 return err;
2026
2027 unwritten = ext4_ext_is_unwritten(ex);
2028 ex->ee_block = newext->ee_block;
2029 ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
2030 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2031 + ext4_ext_get_actual_len(newext));
2032 if (unwritten)
2033 ext4_ext_mark_unwritten(ex);
2034 eh = path[depth].p_hdr;
2035 nearex = ex;
2036 goto merge;
2037 }
2038 }
2039
2040 depth = ext_depth(inode);
2041 eh = path[depth].p_hdr;
2042 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
2043 goto has_space;
2044
2045 /* probably next leaf has space for us? */
2046 fex = EXT_LAST_EXTENT(eh);
2047 next = EXT_MAX_BLOCKS;
2048 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
2049 next = ext4_ext_next_leaf_block(path);
2050 if (next != EXT_MAX_BLOCKS) {
2051 ext_debug("next leaf block - %u\n", next);
2052 BUG_ON(npath != NULL);
2053 npath = ext4_find_extent(inode, next, NULL, 0);
2054 if (IS_ERR(npath))
2055 return PTR_ERR(npath);
2056 BUG_ON(npath->p_depth != path->p_depth);
2057 eh = npath[depth].p_hdr;
2058 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2059 ext_debug("next leaf isn't full(%d)\n",
2060 le16_to_cpu(eh->eh_entries));
2061 path = npath;
2062 goto has_space;
2063 }
2064 ext_debug("next leaf has no free space(%d,%d)\n",
2065 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2066 }
2067
2068 /*
2069 * There is no free space in the found leaf.
2070 * We're gonna add a new leaf in the tree.
2071 */
2072 if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2073 mb_flags |= EXT4_MB_USE_RESERVED;
2074 err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2075 ppath, newext);
2076 if (err)
2077 goto cleanup;
2078 depth = ext_depth(inode);
2079 eh = path[depth].p_hdr;
2080
2081has_space:
2082 nearex = path[depth].p_ext;
2083
2084 err = ext4_ext_get_access(handle, inode, path + depth);
2085 if (err)
2086 goto cleanup;
2087
2088 if (!nearex) {
2089 /* there is no extent in this leaf, create first one */
2090 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
2091 le32_to_cpu(newext->ee_block),
2092 ext4_ext_pblock(newext),
2093 ext4_ext_is_unwritten(newext),
2094 ext4_ext_get_actual_len(newext));
2095 nearex = EXT_FIRST_EXTENT(eh);
2096 } else {
2097 if (le32_to_cpu(newext->ee_block)
2098 > le32_to_cpu(nearex->ee_block)) {
2099 /* Insert after */
2100 ext_debug("insert %u:%llu:[%d]%d before: "
2101 "nearest %p\n",
2102 le32_to_cpu(newext->ee_block),
2103 ext4_ext_pblock(newext),
2104 ext4_ext_is_unwritten(newext),
2105 ext4_ext_get_actual_len(newext),
2106 nearex);
2107 nearex++;
2108 } else {
2109 /* Insert before */
2110 BUG_ON(newext->ee_block == nearex->ee_block);
2111 ext_debug("insert %u:%llu:[%d]%d after: "
2112 "nearest %p\n",
2113 le32_to_cpu(newext->ee_block),
2114 ext4_ext_pblock(newext),
2115 ext4_ext_is_unwritten(newext),
2116 ext4_ext_get_actual_len(newext),
2117 nearex);
2118 }
2119 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2120 if (len > 0) {
2121 ext_debug("insert %u:%llu:[%d]%d: "
2122 "move %d extents from 0x%p to 0x%p\n",
2123 le32_to_cpu(newext->ee_block),
2124 ext4_ext_pblock(newext),
2125 ext4_ext_is_unwritten(newext),
2126 ext4_ext_get_actual_len(newext),
2127 len, nearex, nearex + 1);
2128 memmove(nearex + 1, nearex,
2129 len * sizeof(struct ext4_extent));
2130 }
2131 }
2132
2133 le16_add_cpu(&eh->eh_entries, 1);
2134 path[depth].p_ext = nearex;
2135 nearex->ee_block = newext->ee_block;
2136 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2137 nearex->ee_len = newext->ee_len;
2138
2139merge:
2140 /* try to merge extents */
2141 if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2142 ext4_ext_try_to_merge(handle, inode, path, nearex);
2143
2144
2145 /* time to correct all indexes above */
2146 err = ext4_ext_correct_indexes(handle, inode, path);
2147 if (err)
2148 goto cleanup;
2149
2150 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2151
2152cleanup:
2153 ext4_ext_drop_refs(npath);
2154 kfree(npath);
2155 return err;
2156}
2157
2158static int ext4_fill_fiemap_extents(struct inode *inode,
2159 ext4_lblk_t block, ext4_lblk_t num,
2160 struct fiemap_extent_info *fieinfo)
2161{
2162 struct ext4_ext_path *path = NULL;
2163 struct ext4_extent *ex;
2164 struct extent_status es;
2165 ext4_lblk_t next, next_del, start = 0, end = 0;
2166 ext4_lblk_t last = block + num;
2167 int exists, depth = 0, err = 0;
2168 unsigned int flags = 0;
2169 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2170
2171 while (block < last && block != EXT_MAX_BLOCKS) {
2172 num = last - block;
2173 /* find extent for this block */
2174 down_read(&EXT4_I(inode)->i_data_sem);
2175
2176 path = ext4_find_extent(inode, block, &path, 0);
2177 if (IS_ERR(path)) {
2178 up_read(&EXT4_I(inode)->i_data_sem);
2179 err = PTR_ERR(path);
2180 path = NULL;
2181 break;
2182 }
2183
2184 depth = ext_depth(inode);
2185 if (unlikely(path[depth].p_hdr == NULL)) {
2186 up_read(&EXT4_I(inode)->i_data_sem);
2187 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2188 err = -EFSCORRUPTED;
2189 break;
2190 }
2191 ex = path[depth].p_ext;
2192 next = ext4_ext_next_allocated_block(path);
2193
2194 flags = 0;
2195 exists = 0;
2196 if (!ex) {
2197 /* there is no extent yet, so try to allocate
2198 * all requested space */
2199 start = block;
2200 end = block + num;
2201 } else if (le32_to_cpu(ex->ee_block) > block) {
2202 /* need to allocate space before found extent */
2203 start = block;
2204 end = le32_to_cpu(ex->ee_block);
2205 if (block + num < end)
2206 end = block + num;
2207 } else if (block >= le32_to_cpu(ex->ee_block)
2208 + ext4_ext_get_actual_len(ex)) {
2209 /* need to allocate space after found extent */
2210 start = block;
2211 end = block + num;
2212 if (end >= next)
2213 end = next;
2214 } else if (block >= le32_to_cpu(ex->ee_block)) {
2215 /*
2216 * some part of requested space is covered
2217 * by found extent
2218 */
2219 start = block;
2220 end = le32_to_cpu(ex->ee_block)
2221 + ext4_ext_get_actual_len(ex);
2222 if (block + num < end)
2223 end = block + num;
2224 exists = 1;
2225 } else {
2226 BUG();
2227 }
2228 BUG_ON(end <= start);
2229
2230 if (!exists) {
2231 es.es_lblk = start;
2232 es.es_len = end - start;
2233 es.es_pblk = 0;
2234 } else {
2235 es.es_lblk = le32_to_cpu(ex->ee_block);
2236 es.es_len = ext4_ext_get_actual_len(ex);
2237 es.es_pblk = ext4_ext_pblock(ex);
2238 if (ext4_ext_is_unwritten(ex))
2239 flags |= FIEMAP_EXTENT_UNWRITTEN;
2240 }
2241
2242 /*
2243 * Find delayed extent and update es accordingly. We call
2244 * it even in !exists case to find out whether es is the
2245 * last existing extent or not.
2246 */
2247 next_del = ext4_find_delayed_extent(inode, &es);
2248 if (!exists && next_del) {
2249 exists = 1;
2250 flags |= (FIEMAP_EXTENT_DELALLOC |
2251 FIEMAP_EXTENT_UNKNOWN);
2252 }
2253 up_read(&EXT4_I(inode)->i_data_sem);
2254
2255 if (unlikely(es.es_len == 0)) {
2256 EXT4_ERROR_INODE(inode, "es.es_len == 0");
2257 err = -EFSCORRUPTED;
2258 break;
2259 }
2260
2261 /*
2262 * This is possible iff next == next_del == EXT_MAX_BLOCKS.
2263 * we need to check next == EXT_MAX_BLOCKS because it is
2264 * possible that an extent is with unwritten and delayed
2265 * status due to when an extent is delayed allocated and
2266 * is allocated by fallocate status tree will track both of
2267 * them in a extent.
2268 *
2269 * So we could return a unwritten and delayed extent, and
2270 * its block is equal to 'next'.
2271 */
2272 if (next == next_del && next == EXT_MAX_BLOCKS) {
2273 flags |= FIEMAP_EXTENT_LAST;
2274 if (unlikely(next_del != EXT_MAX_BLOCKS ||
2275 next != EXT_MAX_BLOCKS)) {
2276 EXT4_ERROR_INODE(inode,
2277 "next extent == %u, next "
2278 "delalloc extent = %u",
2279 next, next_del);
2280 err = -EFSCORRUPTED;
2281 break;
2282 }
2283 }
2284
2285 if (exists) {
2286 err = fiemap_fill_next_extent(fieinfo,
2287 (__u64)es.es_lblk << blksize_bits,
2288 (__u64)es.es_pblk << blksize_bits,
2289 (__u64)es.es_len << blksize_bits,
2290 flags);
2291 if (err < 0)
2292 break;
2293 if (err == 1) {
2294 err = 0;
2295 break;
2296 }
2297 }
2298
2299 block = es.es_lblk + es.es_len;
2300 }
2301
2302 ext4_ext_drop_refs(path);
2303 kfree(path);
2304 return err;
2305}
2306
2307/*
2308 * ext4_ext_determine_hole - determine hole around given block
2309 * @inode: inode we lookup in
2310 * @path: path in extent tree to @lblk
2311 * @lblk: pointer to logical block around which we want to determine hole
2312 *
2313 * Determine hole length (and start if easily possible) around given logical
2314 * block. We don't try too hard to find the beginning of the hole but @path
2315 * actually points to extent before @lblk, we provide it.
2316 *
2317 * The function returns the length of a hole starting at @lblk. We update @lblk
2318 * to the beginning of the hole if we managed to find it.
2319 */
2320static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode,
2321 struct ext4_ext_path *path,
2322 ext4_lblk_t *lblk)
2323{
2324 int depth = ext_depth(inode);
2325 struct ext4_extent *ex;
2326 ext4_lblk_t len;
2327
2328 ex = path[depth].p_ext;
2329 if (ex == NULL) {
2330 /* there is no extent yet, so gap is [0;-] */
2331 *lblk = 0;
2332 len = EXT_MAX_BLOCKS;
2333 } else if (*lblk < le32_to_cpu(ex->ee_block)) {
2334 len = le32_to_cpu(ex->ee_block) - *lblk;
2335 } else if (*lblk >= le32_to_cpu(ex->ee_block)
2336 + ext4_ext_get_actual_len(ex)) {
2337 ext4_lblk_t next;
2338
2339 *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
2340 next = ext4_ext_next_allocated_block(path);
2341 BUG_ON(next == *lblk);
2342 len = next - *lblk;
2343 } else {
2344 BUG();
2345 }
2346 return len;
2347}
2348
2349/*
2350 * ext4_ext_put_gap_in_cache:
2351 * calculate boundaries of the gap that the requested block fits into
2352 * and cache this gap
2353 */
2354static void
2355ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start,
2356 ext4_lblk_t hole_len)
2357{
2358 struct extent_status es;
2359
2360 ext4_es_find_delayed_extent_range(inode, hole_start,
2361 hole_start + hole_len - 1, &es);
2362 if (es.es_len) {
2363 /* There's delayed extent containing lblock? */
2364 if (es.es_lblk <= hole_start)
2365 return;
2366 hole_len = min(es.es_lblk - hole_start, hole_len);
2367 }
2368 ext_debug(" -> %u:%u\n", hole_start, hole_len);
2369 ext4_es_insert_extent(inode, hole_start, hole_len, ~0,
2370 EXTENT_STATUS_HOLE);
2371}
2372
2373/*
2374 * ext4_ext_rm_idx:
2375 * removes index from the index block.
2376 */
2377static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2378 struct ext4_ext_path *path, int depth)
2379{
2380 int err;
2381 ext4_fsblk_t leaf;
2382
2383 /* free index block */
2384 depth--;
2385 path = path + depth;
2386 leaf = ext4_idx_pblock(path->p_idx);
2387 if (unlikely(path->p_hdr->eh_entries == 0)) {
2388 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2389 return -EFSCORRUPTED;
2390 }
2391 err = ext4_ext_get_access(handle, inode, path);
2392 if (err)
2393 return err;
2394
2395 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2396 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2397 len *= sizeof(struct ext4_extent_idx);
2398 memmove(path->p_idx, path->p_idx + 1, len);
2399 }
2400
2401 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2402 err = ext4_ext_dirty(handle, inode, path);
2403 if (err)
2404 return err;
2405 ext_debug("index is empty, remove it, free block %llu\n", leaf);
2406 trace_ext4_ext_rm_idx(inode, leaf);
2407
2408 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2409 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2410
2411 while (--depth >= 0) {
2412 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2413 break;
2414 path--;
2415 err = ext4_ext_get_access(handle, inode, path);
2416 if (err)
2417 break;
2418 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2419 err = ext4_ext_dirty(handle, inode, path);
2420 if (err)
2421 break;
2422 }
2423 return err;
2424}
2425
2426/*
2427 * ext4_ext_calc_credits_for_single_extent:
2428 * This routine returns max. credits that needed to insert an extent
2429 * to the extent tree.
2430 * When pass the actual path, the caller should calculate credits
2431 * under i_data_sem.
2432 */
2433int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2434 struct ext4_ext_path *path)
2435{
2436 if (path) {
2437 int depth = ext_depth(inode);
2438 int ret = 0;
2439
2440 /* probably there is space in leaf? */
2441 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2442 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2443
2444 /*
2445 * There are some space in the leaf tree, no
2446 * need to account for leaf block credit
2447 *
2448 * bitmaps and block group descriptor blocks
2449 * and other metadata blocks still need to be
2450 * accounted.
2451 */
2452 /* 1 bitmap, 1 block group descriptor */
2453 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2454 return ret;
2455 }
2456 }
2457
2458 return ext4_chunk_trans_blocks(inode, nrblocks);
2459}
2460
2461/*
2462 * How many index/leaf blocks need to change/allocate to add @extents extents?
2463 *
2464 * If we add a single extent, then in the worse case, each tree level
2465 * index/leaf need to be changed in case of the tree split.
2466 *
2467 * If more extents are inserted, they could cause the whole tree split more
2468 * than once, but this is really rare.
2469 */
2470int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2471{
2472 int index;
2473 int depth;
2474
2475 /* If we are converting the inline data, only one is needed here. */
2476 if (ext4_has_inline_data(inode))
2477 return 1;
2478
2479 depth = ext_depth(inode);
2480
2481 if (extents <= 1)
2482 index = depth * 2;
2483 else
2484 index = depth * 3;
2485
2486 return index;
2487}
2488
2489static inline int get_default_free_blocks_flags(struct inode *inode)
2490{
2491 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2492 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2493 else if (ext4_should_journal_data(inode))
2494 return EXT4_FREE_BLOCKS_FORGET;
2495 return 0;
2496}
2497
2498static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2499 struct ext4_extent *ex,
2500 long long *partial_cluster,
2501 ext4_lblk_t from, ext4_lblk_t to)
2502{
2503 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2504 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2505 ext4_fsblk_t pblk;
2506 int flags = get_default_free_blocks_flags(inode);
2507
2508 /*
2509 * For bigalloc file systems, we never free a partial cluster
2510 * at the beginning of the extent. Instead, we make a note
2511 * that we tried freeing the cluster, and check to see if we
2512 * need to free it on a subsequent call to ext4_remove_blocks,
2513 * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
2514 */
2515 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2516
2517 trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2518 /*
2519 * If we have a partial cluster, and it's different from the
2520 * cluster of the last block, we need to explicitly free the
2521 * partial cluster here.
2522 */
2523 pblk = ext4_ext_pblock(ex) + ee_len - 1;
2524 if (*partial_cluster > 0 &&
2525 *partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2526 ext4_free_blocks(handle, inode, NULL,
2527 EXT4_C2B(sbi, *partial_cluster),
2528 sbi->s_cluster_ratio, flags);
2529 *partial_cluster = 0;
2530 }
2531
2532#ifdef EXTENTS_STATS
2533 {
2534 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2535 spin_lock(&sbi->s_ext_stats_lock);
2536 sbi->s_ext_blocks += ee_len;
2537 sbi->s_ext_extents++;
2538 if (ee_len < sbi->s_ext_min)
2539 sbi->s_ext_min = ee_len;
2540 if (ee_len > sbi->s_ext_max)
2541 sbi->s_ext_max = ee_len;
2542 if (ext_depth(inode) > sbi->s_depth_max)
2543 sbi->s_depth_max = ext_depth(inode);
2544 spin_unlock(&sbi->s_ext_stats_lock);
2545 }
2546#endif
2547 if (from >= le32_to_cpu(ex->ee_block)
2548 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2549 /* tail removal */
2550 ext4_lblk_t num;
2551 long long first_cluster;
2552
2553 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2554 pblk = ext4_ext_pblock(ex) + ee_len - num;
2555 /*
2556 * Usually we want to free partial cluster at the end of the
2557 * extent, except for the situation when the cluster is still
2558 * used by any other extent (partial_cluster is negative).
2559 */
2560 if (*partial_cluster < 0 &&
2561 *partial_cluster == -(long long) EXT4_B2C(sbi, pblk+num-1))
2562 flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2563
2564 ext_debug("free last %u blocks starting %llu partial %lld\n",
2565 num, pblk, *partial_cluster);
2566 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2567 /*
2568 * If the block range to be freed didn't start at the
2569 * beginning of a cluster, and we removed the entire
2570 * extent and the cluster is not used by any other extent,
2571 * save the partial cluster here, since we might need to
2572 * delete if we determine that the truncate or punch hole
2573 * operation has removed all of the blocks in the cluster.
2574 * If that cluster is used by another extent, preserve its
2575 * negative value so it isn't freed later on.
2576 *
2577 * If the whole extent wasn't freed, we've reached the
2578 * start of the truncated/punched region and have finished
2579 * removing blocks. If there's a partial cluster here it's
2580 * shared with the remainder of the extent and is no longer
2581 * a candidate for removal.
2582 */
2583 if (EXT4_PBLK_COFF(sbi, pblk) && ee_len == num) {
2584 first_cluster = (long long) EXT4_B2C(sbi, pblk);
2585 if (first_cluster != -*partial_cluster)
2586 *partial_cluster = first_cluster;
2587 } else {
2588 *partial_cluster = 0;
2589 }
2590 } else
2591 ext4_error(sbi->s_sb, "strange request: removal(2) "
2592 "%u-%u from %u:%u",
2593 from, to, le32_to_cpu(ex->ee_block), ee_len);
2594 return 0;
2595}
2596
2597
2598/*
2599 * ext4_ext_rm_leaf() Removes the extents associated with the
2600 * blocks appearing between "start" and "end". Both "start"
2601 * and "end" must appear in the same extent or EIO is returned.
2602 *
2603 * @handle: The journal handle
2604 * @inode: The files inode
2605 * @path: The path to the leaf
2606 * @partial_cluster: The cluster which we'll have to free if all extents
2607 * has been released from it. However, if this value is
2608 * negative, it's a cluster just to the right of the
2609 * punched region and it must not be freed.
2610 * @start: The first block to remove
2611 * @end: The last block to remove
2612 */
2613static int
2614ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2615 struct ext4_ext_path *path,
2616 long long *partial_cluster,
2617 ext4_lblk_t start, ext4_lblk_t end)
2618{
2619 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2620 int err = 0, correct_index = 0;
2621 int depth = ext_depth(inode), credits;
2622 struct ext4_extent_header *eh;
2623 ext4_lblk_t a, b;
2624 unsigned num;
2625 ext4_lblk_t ex_ee_block;
2626 unsigned short ex_ee_len;
2627 unsigned unwritten = 0;
2628 struct ext4_extent *ex;
2629 ext4_fsblk_t pblk;
2630
2631 /* the header must be checked already in ext4_ext_remove_space() */
2632 ext_debug("truncate since %u in leaf to %u\n", start, end);
2633 if (!path[depth].p_hdr)
2634 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2635 eh = path[depth].p_hdr;
2636 if (unlikely(path[depth].p_hdr == NULL)) {
2637 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2638 return -EFSCORRUPTED;
2639 }
2640 /* find where to start removing */
2641 ex = path[depth].p_ext;
2642 if (!ex)
2643 ex = EXT_LAST_EXTENT(eh);
2644
2645 ex_ee_block = le32_to_cpu(ex->ee_block);
2646 ex_ee_len = ext4_ext_get_actual_len(ex);
2647
2648 trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2649
2650 while (ex >= EXT_FIRST_EXTENT(eh) &&
2651 ex_ee_block + ex_ee_len > start) {
2652
2653 if (ext4_ext_is_unwritten(ex))
2654 unwritten = 1;
2655 else
2656 unwritten = 0;
2657
2658 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2659 unwritten, ex_ee_len);
2660 path[depth].p_ext = ex;
2661
2662 a = ex_ee_block > start ? ex_ee_block : start;
2663 b = ex_ee_block+ex_ee_len - 1 < end ?
2664 ex_ee_block+ex_ee_len - 1 : end;
2665
2666 ext_debug(" border %u:%u\n", a, b);
2667
2668 /* If this extent is beyond the end of the hole, skip it */
2669 if (end < ex_ee_block) {
2670 /*
2671 * We're going to skip this extent and move to another,
2672 * so note that its first cluster is in use to avoid
2673 * freeing it when removing blocks. Eventually, the
2674 * right edge of the truncated/punched region will
2675 * be just to the left.
2676 */
2677 if (sbi->s_cluster_ratio > 1) {
2678 pblk = ext4_ext_pblock(ex);
2679 *partial_cluster =
2680 -(long long) EXT4_B2C(sbi, pblk);
2681 }
2682 ex--;
2683 ex_ee_block = le32_to_cpu(ex->ee_block);
2684 ex_ee_len = ext4_ext_get_actual_len(ex);
2685 continue;
2686 } else if (b != ex_ee_block + ex_ee_len - 1) {
2687 EXT4_ERROR_INODE(inode,
2688 "can not handle truncate %u:%u "
2689 "on extent %u:%u",
2690 start, end, ex_ee_block,
2691 ex_ee_block + ex_ee_len - 1);
2692 err = -EFSCORRUPTED;
2693 goto out;
2694 } else if (a != ex_ee_block) {
2695 /* remove tail of the extent */
2696 num = a - ex_ee_block;
2697 } else {
2698 /* remove whole extent: excellent! */
2699 num = 0;
2700 }
2701 /*
2702 * 3 for leaf, sb, and inode plus 2 (bmap and group
2703 * descriptor) for each block group; assume two block
2704 * groups plus ex_ee_len/blocks_per_block_group for
2705 * the worst case
2706 */
2707 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2708 if (ex == EXT_FIRST_EXTENT(eh)) {
2709 correct_index = 1;
2710 credits += (ext_depth(inode)) + 1;
2711 }
2712 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2713
2714 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2715 if (err)
2716 goto out;
2717
2718 err = ext4_ext_get_access(handle, inode, path + depth);
2719 if (err)
2720 goto out;
2721
2722 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2723 a, b);
2724 if (err)
2725 goto out;
2726
2727 if (num == 0)
2728 /* this extent is removed; mark slot entirely unused */
2729 ext4_ext_store_pblock(ex, 0);
2730
2731 ex->ee_len = cpu_to_le16(num);
2732 /*
2733 * Do not mark unwritten if all the blocks in the
2734 * extent have been removed.
2735 */
2736 if (unwritten && num)
2737 ext4_ext_mark_unwritten(ex);
2738 /*
2739 * If the extent was completely released,
2740 * we need to remove it from the leaf
2741 */
2742 if (num == 0) {
2743 if (end != EXT_MAX_BLOCKS - 1) {
2744 /*
2745 * For hole punching, we need to scoot all the
2746 * extents up when an extent is removed so that
2747 * we dont have blank extents in the middle
2748 */
2749 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2750 sizeof(struct ext4_extent));
2751
2752 /* Now get rid of the one at the end */
2753 memset(EXT_LAST_EXTENT(eh), 0,
2754 sizeof(struct ext4_extent));
2755 }
2756 le16_add_cpu(&eh->eh_entries, -1);
2757 }
2758
2759 err = ext4_ext_dirty(handle, inode, path + depth);
2760 if (err)
2761 goto out;
2762
2763 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2764 ext4_ext_pblock(ex));
2765 ex--;
2766 ex_ee_block = le32_to_cpu(ex->ee_block);
2767 ex_ee_len = ext4_ext_get_actual_len(ex);
2768 }
2769
2770 if (correct_index && eh->eh_entries)
2771 err = ext4_ext_correct_indexes(handle, inode, path);
2772
2773 /*
2774 * If there's a partial cluster and at least one extent remains in
2775 * the leaf, free the partial cluster if it isn't shared with the
2776 * current extent. If it is shared with the current extent
2777 * we zero partial_cluster because we've reached the start of the
2778 * truncated/punched region and we're done removing blocks.
2779 */
2780 if (*partial_cluster > 0 && ex >= EXT_FIRST_EXTENT(eh)) {
2781 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
2782 if (*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2783 ext4_free_blocks(handle, inode, NULL,
2784 EXT4_C2B(sbi, *partial_cluster),
2785 sbi->s_cluster_ratio,
2786 get_default_free_blocks_flags(inode));
2787 }
2788 *partial_cluster = 0;
2789 }
2790
2791 /* if this leaf is free, then we should
2792 * remove it from index block above */
2793 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2794 err = ext4_ext_rm_idx(handle, inode, path, depth);
2795
2796out:
2797 return err;
2798}
2799
2800/*
2801 * ext4_ext_more_to_rm:
2802 * returns 1 if current index has to be freed (even partial)
2803 */
2804static int
2805ext4_ext_more_to_rm(struct ext4_ext_path *path)
2806{
2807 BUG_ON(path->p_idx == NULL);
2808
2809 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2810 return 0;
2811
2812 /*
2813 * if truncate on deeper level happened, it wasn't partial,
2814 * so we have to consider current index for truncation
2815 */
2816 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2817 return 0;
2818 return 1;
2819}
2820
2821int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2822 ext4_lblk_t end)
2823{
2824 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2825 int depth = ext_depth(inode);
2826 struct ext4_ext_path *path = NULL;
2827 long long partial_cluster = 0;
2828 handle_t *handle;
2829 int i = 0, err = 0;
2830
2831 ext_debug("truncate since %u to %u\n", start, end);
2832
2833 /* probably first extent we're gonna free will be last in block */
2834 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1);
2835 if (IS_ERR(handle))
2836 return PTR_ERR(handle);
2837
2838again:
2839 trace_ext4_ext_remove_space(inode, start, end, depth);
2840
2841 /*
2842 * Check if we are removing extents inside the extent tree. If that
2843 * is the case, we are going to punch a hole inside the extent tree
2844 * so we have to check whether we need to split the extent covering
2845 * the last block to remove so we can easily remove the part of it
2846 * in ext4_ext_rm_leaf().
2847 */
2848 if (end < EXT_MAX_BLOCKS - 1) {
2849 struct ext4_extent *ex;
2850 ext4_lblk_t ee_block, ex_end, lblk;
2851 ext4_fsblk_t pblk;
2852
2853 /* find extent for or closest extent to this block */
2854 path = ext4_find_extent(inode, end, NULL, EXT4_EX_NOCACHE);
2855 if (IS_ERR(path)) {
2856 ext4_journal_stop(handle);
2857 return PTR_ERR(path);
2858 }
2859 depth = ext_depth(inode);
2860 /* Leaf not may not exist only if inode has no blocks at all */
2861 ex = path[depth].p_ext;
2862 if (!ex) {
2863 if (depth) {
2864 EXT4_ERROR_INODE(inode,
2865 "path[%d].p_hdr == NULL",
2866 depth);
2867 err = -EFSCORRUPTED;
2868 }
2869 goto out;
2870 }
2871
2872 ee_block = le32_to_cpu(ex->ee_block);
2873 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
2874
2875 /*
2876 * See if the last block is inside the extent, if so split
2877 * the extent at 'end' block so we can easily remove the
2878 * tail of the first part of the split extent in
2879 * ext4_ext_rm_leaf().
2880 */
2881 if (end >= ee_block && end < ex_end) {
2882
2883 /*
2884 * If we're going to split the extent, note that
2885 * the cluster containing the block after 'end' is
2886 * in use to avoid freeing it when removing blocks.
2887 */
2888 if (sbi->s_cluster_ratio > 1) {
2889 pblk = ext4_ext_pblock(ex) + end - ee_block + 2;
2890 partial_cluster =
2891 -(long long) EXT4_B2C(sbi, pblk);
2892 }
2893
2894 /*
2895 * Split the extent in two so that 'end' is the last
2896 * block in the first new extent. Also we should not
2897 * fail removing space due to ENOSPC so try to use
2898 * reserved block if that happens.
2899 */
2900 err = ext4_force_split_extent_at(handle, inode, &path,
2901 end + 1, 1);
2902 if (err < 0)
2903 goto out;
2904
2905 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end) {
2906 /*
2907 * If there's an extent to the right its first cluster
2908 * contains the immediate right boundary of the
2909 * truncated/punched region. Set partial_cluster to
2910 * its negative value so it won't be freed if shared
2911 * with the current extent. The end < ee_block case
2912 * is handled in ext4_ext_rm_leaf().
2913 */
2914 lblk = ex_end + 1;
2915 err = ext4_ext_search_right(inode, path, &lblk, &pblk,
2916 &ex);
2917 if (err)
2918 goto out;
2919 if (pblk)
2920 partial_cluster =
2921 -(long long) EXT4_B2C(sbi, pblk);
2922 }
2923 }
2924 /*
2925 * We start scanning from right side, freeing all the blocks
2926 * after i_size and walking into the tree depth-wise.
2927 */
2928 depth = ext_depth(inode);
2929 if (path) {
2930 int k = i = depth;
2931 while (--k > 0)
2932 path[k].p_block =
2933 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2934 } else {
2935 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2936 GFP_NOFS);
2937 if (path == NULL) {
2938 ext4_journal_stop(handle);
2939 return -ENOMEM;
2940 }
2941 path[0].p_maxdepth = path[0].p_depth = depth;
2942 path[0].p_hdr = ext_inode_hdr(inode);
2943 i = 0;
2944
2945 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2946 err = -EFSCORRUPTED;
2947 goto out;
2948 }
2949 }
2950 err = 0;
2951
2952 while (i >= 0 && err == 0) {
2953 if (i == depth) {
2954 /* this is leaf block */
2955 err = ext4_ext_rm_leaf(handle, inode, path,
2956 &partial_cluster, start,
2957 end);
2958 /* root level has p_bh == NULL, brelse() eats this */
2959 brelse(path[i].p_bh);
2960 path[i].p_bh = NULL;
2961 i--;
2962 continue;
2963 }
2964
2965 /* this is index block */
2966 if (!path[i].p_hdr) {
2967 ext_debug("initialize header\n");
2968 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2969 }
2970
2971 if (!path[i].p_idx) {
2972 /* this level hasn't been touched yet */
2973 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2974 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2975 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2976 path[i].p_hdr,
2977 le16_to_cpu(path[i].p_hdr->eh_entries));
2978 } else {
2979 /* we were already here, see at next index */
2980 path[i].p_idx--;
2981 }
2982
2983 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2984 i, EXT_FIRST_INDEX(path[i].p_hdr),
2985 path[i].p_idx);
2986 if (ext4_ext_more_to_rm(path + i)) {
2987 struct buffer_head *bh;
2988 /* go to the next level */
2989 ext_debug("move to level %d (block %llu)\n",
2990 i + 1, ext4_idx_pblock(path[i].p_idx));
2991 memset(path + i + 1, 0, sizeof(*path));
2992 bh = read_extent_tree_block(inode,
2993 ext4_idx_pblock(path[i].p_idx), depth - i - 1,
2994 EXT4_EX_NOCACHE);
2995 if (IS_ERR(bh)) {
2996 /* should we reset i_size? */
2997 err = PTR_ERR(bh);
2998 break;
2999 }
3000 /* Yield here to deal with large extent trees.
3001 * Should be a no-op if we did IO above. */
3002 cond_resched();
3003 if (WARN_ON(i + 1 > depth)) {
3004 err = -EFSCORRUPTED;
3005 break;
3006 }
3007 path[i + 1].p_bh = bh;
3008
3009 /* save actual number of indexes since this
3010 * number is changed at the next iteration */
3011 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
3012 i++;
3013 } else {
3014 /* we finished processing this index, go up */
3015 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
3016 /* index is empty, remove it;
3017 * handle must be already prepared by the
3018 * truncatei_leaf() */
3019 err = ext4_ext_rm_idx(handle, inode, path, i);
3020 }
3021 /* root level has p_bh == NULL, brelse() eats this */
3022 brelse(path[i].p_bh);
3023 path[i].p_bh = NULL;
3024 i--;
3025 ext_debug("return to level %d\n", i);
3026 }
3027 }
3028
3029 trace_ext4_ext_remove_space_done(inode, start, end, depth,
3030 partial_cluster, path->p_hdr->eh_entries);
3031
3032 /*
3033 * If we still have something in the partial cluster and we have removed
3034 * even the first extent, then we should free the blocks in the partial
3035 * cluster as well. (This code will only run when there are no leaves
3036 * to the immediate left of the truncated/punched region.)
3037 */
3038 if (partial_cluster > 0 && err == 0) {
3039 /* don't zero partial_cluster since it's not used afterwards */
3040 ext4_free_blocks(handle, inode, NULL,
3041 EXT4_C2B(sbi, partial_cluster),
3042 sbi->s_cluster_ratio,
3043 get_default_free_blocks_flags(inode));
3044 }
3045
3046 /* TODO: flexible tree reduction should be here */
3047 if (path->p_hdr->eh_entries == 0) {
3048 /*
3049 * truncate to zero freed all the tree,
3050 * so we need to correct eh_depth
3051 */
3052 err = ext4_ext_get_access(handle, inode, path);
3053 if (err == 0) {
3054 ext_inode_hdr(inode)->eh_depth = 0;
3055 ext_inode_hdr(inode)->eh_max =
3056 cpu_to_le16(ext4_ext_space_root(inode, 0));
3057 err = ext4_ext_dirty(handle, inode, path);
3058 }
3059 }
3060out:
3061 ext4_ext_drop_refs(path);
3062 kfree(path);
3063 path = NULL;
3064 if (err == -EAGAIN)
3065 goto again;
3066 ext4_journal_stop(handle);
3067
3068 return err;
3069}
3070
3071/*
3072 * called at mount time
3073 */
3074void ext4_ext_init(struct super_block *sb)
3075{
3076 /*
3077 * possible initialization would be here
3078 */
3079
3080 if (ext4_has_feature_extents(sb)) {
3081#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
3082 printk(KERN_INFO "EXT4-fs: file extents enabled"
3083#ifdef AGGRESSIVE_TEST
3084 ", aggressive tests"
3085#endif
3086#ifdef CHECK_BINSEARCH
3087 ", check binsearch"
3088#endif
3089#ifdef EXTENTS_STATS
3090 ", stats"
3091#endif
3092 "\n");
3093#endif
3094#ifdef EXTENTS_STATS
3095 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3096 EXT4_SB(sb)->s_ext_min = 1 << 30;
3097 EXT4_SB(sb)->s_ext_max = 0;
3098#endif
3099 }
3100}
3101
3102/*
3103 * called at umount time
3104 */
3105void ext4_ext_release(struct super_block *sb)
3106{
3107 if (!ext4_has_feature_extents(sb))
3108 return;
3109
3110#ifdef EXTENTS_STATS
3111 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3112 struct ext4_sb_info *sbi = EXT4_SB(sb);
3113 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3114 sbi->s_ext_blocks, sbi->s_ext_extents,
3115 sbi->s_ext_blocks / sbi->s_ext_extents);
3116 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3117 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3118 }
3119#endif
3120}
3121
3122static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3123{
3124 ext4_lblk_t ee_block;
3125 ext4_fsblk_t ee_pblock;
3126 unsigned int ee_len;
3127
3128 ee_block = le32_to_cpu(ex->ee_block);
3129 ee_len = ext4_ext_get_actual_len(ex);
3130 ee_pblock = ext4_ext_pblock(ex);
3131
3132 if (ee_len == 0)
3133 return 0;
3134
3135 return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3136 EXTENT_STATUS_WRITTEN);
3137}
3138
3139/* FIXME!! we need to try to merge to left or right after zero-out */
3140static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3141{
3142 ext4_fsblk_t ee_pblock;
3143 unsigned int ee_len;
3144
3145 ee_len = ext4_ext_get_actual_len(ex);
3146 ee_pblock = ext4_ext_pblock(ex);
3147 return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock,
3148 ee_len);
3149}
3150
3151/*
3152 * ext4_split_extent_at() splits an extent at given block.
3153 *
3154 * @handle: the journal handle
3155 * @inode: the file inode
3156 * @path: the path to the extent
3157 * @split: the logical block where the extent is splitted.
3158 * @split_flags: indicates if the extent could be zeroout if split fails, and
3159 * the states(init or unwritten) of new extents.
3160 * @flags: flags used to insert new extent to extent tree.
3161 *
3162 *
3163 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3164 * of which are deterimined by split_flag.
3165 *
3166 * There are two cases:
3167 * a> the extent are splitted into two extent.
3168 * b> split is not needed, and just mark the extent.
3169 *
3170 * return 0 on success.
3171 */
3172static int ext4_split_extent_at(handle_t *handle,
3173 struct inode *inode,
3174 struct ext4_ext_path **ppath,
3175 ext4_lblk_t split,
3176 int split_flag,
3177 int flags)
3178{
3179 struct ext4_ext_path *path = *ppath;
3180 ext4_fsblk_t newblock;
3181 ext4_lblk_t ee_block;
3182 struct ext4_extent *ex, newex, orig_ex, zero_ex;
3183 struct ext4_extent *ex2 = NULL;
3184 unsigned int ee_len, depth;
3185 int err = 0;
3186
3187 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3188 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3189
3190 ext_debug("ext4_split_extents_at: inode %lu, logical"
3191 "block %llu\n", inode->i_ino, (unsigned long long)split);
3192
3193 ext4_ext_show_leaf(inode, path);
3194
3195 depth = ext_depth(inode);
3196 ex = path[depth].p_ext;
3197 ee_block = le32_to_cpu(ex->ee_block);
3198 ee_len = ext4_ext_get_actual_len(ex);
3199 newblock = split - ee_block + ext4_ext_pblock(ex);
3200
3201 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3202 BUG_ON(!ext4_ext_is_unwritten(ex) &&
3203 split_flag & (EXT4_EXT_MAY_ZEROOUT |
3204 EXT4_EXT_MARK_UNWRIT1 |
3205 EXT4_EXT_MARK_UNWRIT2));
3206
3207 err = ext4_ext_get_access(handle, inode, path + depth);
3208 if (err)
3209 goto out;
3210
3211 if (split == ee_block) {
3212 /*
3213 * case b: block @split is the block that the extent begins with
3214 * then we just change the state of the extent, and splitting
3215 * is not needed.
3216 */
3217 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3218 ext4_ext_mark_unwritten(ex);
3219 else
3220 ext4_ext_mark_initialized(ex);
3221
3222 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3223 ext4_ext_try_to_merge(handle, inode, path, ex);
3224
3225 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3226 goto out;
3227 }
3228
3229 /* case a */
3230 memcpy(&orig_ex, ex, sizeof(orig_ex));
3231 ex->ee_len = cpu_to_le16(split - ee_block);
3232 if (split_flag & EXT4_EXT_MARK_UNWRIT1)
3233 ext4_ext_mark_unwritten(ex);
3234
3235 /*
3236 * path may lead to new leaf, not to original leaf any more
3237 * after ext4_ext_insert_extent() returns,
3238 */
3239 err = ext4_ext_dirty(handle, inode, path + depth);
3240 if (err)
3241 goto fix_extent_len;
3242
3243 ex2 = &newex;
3244 ex2->ee_block = cpu_to_le32(split);
3245 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
3246 ext4_ext_store_pblock(ex2, newblock);
3247 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3248 ext4_ext_mark_unwritten(ex2);
3249
3250 err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
3251 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3252 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3253 if (split_flag & EXT4_EXT_DATA_VALID1) {
3254 err = ext4_ext_zeroout(inode, ex2);
3255 zero_ex.ee_block = ex2->ee_block;
3256 zero_ex.ee_len = cpu_to_le16(
3257 ext4_ext_get_actual_len(ex2));
3258 ext4_ext_store_pblock(&zero_ex,
3259 ext4_ext_pblock(ex2));
3260 } else {
3261 err = ext4_ext_zeroout(inode, ex);
3262 zero_ex.ee_block = ex->ee_block;
3263 zero_ex.ee_len = cpu_to_le16(
3264 ext4_ext_get_actual_len(ex));
3265 ext4_ext_store_pblock(&zero_ex,
3266 ext4_ext_pblock(ex));
3267 }
3268 } else {
3269 err = ext4_ext_zeroout(inode, &orig_ex);
3270 zero_ex.ee_block = orig_ex.ee_block;
3271 zero_ex.ee_len = cpu_to_le16(
3272 ext4_ext_get_actual_len(&orig_ex));
3273 ext4_ext_store_pblock(&zero_ex,
3274 ext4_ext_pblock(&orig_ex));
3275 }
3276
3277 if (err)
3278 goto fix_extent_len;
3279 /* update the extent length and mark as initialized */
3280 ex->ee_len = cpu_to_le16(ee_len);
3281 ext4_ext_try_to_merge(handle, inode, path, ex);
3282 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3283 if (err)
3284 goto fix_extent_len;
3285
3286 /* update extent status tree */
3287 err = ext4_zeroout_es(inode, &zero_ex);
3288
3289 goto out;
3290 } else if (err)
3291 goto fix_extent_len;
3292
3293out:
3294 ext4_ext_show_leaf(inode, path);
3295 return err;
3296
3297fix_extent_len:
3298 ex->ee_len = orig_ex.ee_len;
3299 ext4_ext_dirty(handle, inode, path + path->p_depth);
3300 return err;
3301}
3302
3303/*
3304 * ext4_split_extents() splits an extent and mark extent which is covered
3305 * by @map as split_flags indicates
3306 *
3307 * It may result in splitting the extent into multiple extents (up to three)
3308 * There are three possibilities:
3309 * a> There is no split required
3310 * b> Splits in two extents: Split is happening at either end of the extent
3311 * c> Splits in three extents: Somone is splitting in middle of the extent
3312 *
3313 */
3314static int ext4_split_extent(handle_t *handle,
3315 struct inode *inode,
3316 struct ext4_ext_path **ppath,
3317 struct ext4_map_blocks *map,
3318 int split_flag,
3319 int flags)
3320{
3321 struct ext4_ext_path *path = *ppath;
3322 ext4_lblk_t ee_block;
3323 struct ext4_extent *ex;
3324 unsigned int ee_len, depth;
3325 int err = 0;
3326 int unwritten;
3327 int split_flag1, flags1;
3328 int allocated = map->m_len;
3329
3330 depth = ext_depth(inode);
3331 ex = path[depth].p_ext;
3332 ee_block = le32_to_cpu(ex->ee_block);
3333 ee_len = ext4_ext_get_actual_len(ex);
3334 unwritten = ext4_ext_is_unwritten(ex);
3335
3336 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3337 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3338 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3339 if (unwritten)
3340 split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
3341 EXT4_EXT_MARK_UNWRIT2;
3342 if (split_flag & EXT4_EXT_DATA_VALID2)
3343 split_flag1 |= EXT4_EXT_DATA_VALID1;
3344 err = ext4_split_extent_at(handle, inode, ppath,
3345 map->m_lblk + map->m_len, split_flag1, flags1);
3346 if (err)
3347 goto out;
3348 } else {
3349 allocated = ee_len - (map->m_lblk - ee_block);
3350 }
3351 /*
3352 * Update path is required because previous ext4_split_extent_at() may
3353 * result in split of original leaf or extent zeroout.
3354 */
3355 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3356 if (IS_ERR(path))
3357 return PTR_ERR(path);
3358 depth = ext_depth(inode);
3359 ex = path[depth].p_ext;
3360 if (!ex) {
3361 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3362 (unsigned long) map->m_lblk);
3363 return -EFSCORRUPTED;
3364 }
3365 unwritten = ext4_ext_is_unwritten(ex);
3366 split_flag1 = 0;
3367
3368 if (map->m_lblk >= ee_block) {
3369 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3370 if (unwritten) {
3371 split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
3372 split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3373 EXT4_EXT_MARK_UNWRIT2);
3374 }
3375 err = ext4_split_extent_at(handle, inode, ppath,
3376 map->m_lblk, split_flag1, flags);
3377 if (err)
3378 goto out;
3379 }
3380
3381 ext4_ext_show_leaf(inode, path);
3382out:
3383 return err ? err : allocated;
3384}
3385
3386/*
3387 * This function is called by ext4_ext_map_blocks() if someone tries to write
3388 * to an unwritten extent. It may result in splitting the unwritten
3389 * extent into multiple extents (up to three - one initialized and two
3390 * unwritten).
3391 * There are three possibilities:
3392 * a> There is no split required: Entire extent should be initialized
3393 * b> Splits in two extents: Write is happening at either end of the extent
3394 * c> Splits in three extents: Somone is writing in middle of the extent
3395 *
3396 * Pre-conditions:
3397 * - The extent pointed to by 'path' is unwritten.
3398 * - The extent pointed to by 'path' contains a superset
3399 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3400 *
3401 * Post-conditions on success:
3402 * - the returned value is the number of blocks beyond map->l_lblk
3403 * that are allocated and initialized.
3404 * It is guaranteed to be >= map->m_len.
3405 */
3406static int ext4_ext_convert_to_initialized(handle_t *handle,
3407 struct inode *inode,
3408 struct ext4_map_blocks *map,
3409 struct ext4_ext_path **ppath,
3410 int flags)
3411{
3412 struct ext4_ext_path *path = *ppath;
3413 struct ext4_sb_info *sbi;
3414 struct ext4_extent_header *eh;
3415 struct ext4_map_blocks split_map;
3416 struct ext4_extent zero_ex;
3417 struct ext4_extent *ex, *abut_ex;
3418 ext4_lblk_t ee_block, eof_block;
3419 unsigned int ee_len, depth, map_len = map->m_len;
3420 int allocated = 0, max_zeroout = 0;
3421 int err = 0;
3422 int split_flag = 0;
3423
3424 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3425 "block %llu, max_blocks %u\n", inode->i_ino,
3426 (unsigned long long)map->m_lblk, map_len);
3427
3428 sbi = EXT4_SB(inode->i_sb);
3429 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3430 inode->i_sb->s_blocksize_bits;
3431 if (eof_block < map->m_lblk + map_len)
3432 eof_block = map->m_lblk + map_len;
3433
3434 depth = ext_depth(inode);
3435 eh = path[depth].p_hdr;
3436 ex = path[depth].p_ext;
3437 ee_block = le32_to_cpu(ex->ee_block);
3438 ee_len = ext4_ext_get_actual_len(ex);
3439 zero_ex.ee_len = 0;
3440
3441 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3442
3443 /* Pre-conditions */
3444 BUG_ON(!ext4_ext_is_unwritten(ex));
3445 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3446
3447 /*
3448 * Attempt to transfer newly initialized blocks from the currently
3449 * unwritten extent to its neighbor. This is much cheaper
3450 * than an insertion followed by a merge as those involve costly
3451 * memmove() calls. Transferring to the left is the common case in
3452 * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3453 * followed by append writes.
3454 *
3455 * Limitations of the current logic:
3456 * - L1: we do not deal with writes covering the whole extent.
3457 * This would require removing the extent if the transfer
3458 * is possible.
3459 * - L2: we only attempt to merge with an extent stored in the
3460 * same extent tree node.
3461 */
3462 if ((map->m_lblk == ee_block) &&
3463 /* See if we can merge left */
3464 (map_len < ee_len) && /*L1*/
3465 (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/
3466 ext4_lblk_t prev_lblk;
3467 ext4_fsblk_t prev_pblk, ee_pblk;
3468 unsigned int prev_len;
3469
3470 abut_ex = ex - 1;
3471 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3472 prev_len = ext4_ext_get_actual_len(abut_ex);
3473 prev_pblk = ext4_ext_pblock(abut_ex);
3474 ee_pblk = ext4_ext_pblock(ex);
3475
3476 /*
3477 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3478 * upon those conditions:
3479 * - C1: abut_ex is initialized,
3480 * - C2: abut_ex is logically abutting ex,
3481 * - C3: abut_ex is physically abutting ex,
3482 * - C4: abut_ex can receive the additional blocks without
3483 * overflowing the (initialized) length limit.
3484 */
3485 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3486 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3487 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3488 (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3489 err = ext4_ext_get_access(handle, inode, path + depth);
3490 if (err)
3491 goto out;
3492
3493 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3494 map, ex, abut_ex);
3495
3496 /* Shift the start of ex by 'map_len' blocks */
3497 ex->ee_block = cpu_to_le32(ee_block + map_len);
3498 ext4_ext_store_pblock(ex, ee_pblk + map_len);
3499 ex->ee_len = cpu_to_le16(ee_len - map_len);
3500 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3501
3502 /* Extend abut_ex by 'map_len' blocks */
3503 abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3504
3505 /* Result: number of initialized blocks past m_lblk */
3506 allocated = map_len;
3507 }
3508 } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3509 (map_len < ee_len) && /*L1*/
3510 ex < EXT_LAST_EXTENT(eh)) { /*L2*/
3511 /* See if we can merge right */
3512 ext4_lblk_t next_lblk;
3513 ext4_fsblk_t next_pblk, ee_pblk;
3514 unsigned int next_len;
3515
3516 abut_ex = ex + 1;
3517 next_lblk = le32_to_cpu(abut_ex->ee_block);
3518 next_len = ext4_ext_get_actual_len(abut_ex);
3519 next_pblk = ext4_ext_pblock(abut_ex);
3520 ee_pblk = ext4_ext_pblock(ex);
3521
3522 /*
3523 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3524 * upon those conditions:
3525 * - C1: abut_ex is initialized,
3526 * - C2: abut_ex is logically abutting ex,
3527 * - C3: abut_ex is physically abutting ex,
3528 * - C4: abut_ex can receive the additional blocks without
3529 * overflowing the (initialized) length limit.
3530 */
3531 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3532 ((map->m_lblk + map_len) == next_lblk) && /*C2*/
3533 ((ee_pblk + ee_len) == next_pblk) && /*C3*/
3534 (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3535 err = ext4_ext_get_access(handle, inode, path + depth);
3536 if (err)
3537 goto out;
3538
3539 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3540 map, ex, abut_ex);
3541
3542 /* Shift the start of abut_ex by 'map_len' blocks */
3543 abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3544 ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3545 ex->ee_len = cpu_to_le16(ee_len - map_len);
3546 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3547
3548 /* Extend abut_ex by 'map_len' blocks */
3549 abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3550
3551 /* Result: number of initialized blocks past m_lblk */
3552 allocated = map_len;
3553 }
3554 }
3555 if (allocated) {
3556 /* Mark the block containing both extents as dirty */
3557 ext4_ext_dirty(handle, inode, path + depth);
3558
3559 /* Update path to point to the right extent */
3560 path[depth].p_ext = abut_ex;
3561 goto out;
3562 } else
3563 allocated = ee_len - (map->m_lblk - ee_block);
3564
3565 WARN_ON(map->m_lblk < ee_block);
3566 /*
3567 * It is safe to convert extent to initialized via explicit
3568 * zeroout only if extent is fully inside i_size or new_size.
3569 */
3570 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3571
3572 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3573 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3574 (inode->i_sb->s_blocksize_bits - 10);
3575
3576 if (ext4_encrypted_inode(inode))
3577 max_zeroout = 0;
3578
3579 /* If extent is less than s_max_zeroout_kb, zeroout directly */
3580 if (max_zeroout && (ee_len <= max_zeroout)) {
3581 err = ext4_ext_zeroout(inode, ex);
3582 if (err)
3583 goto out;
3584 zero_ex.ee_block = ex->ee_block;
3585 zero_ex.ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex));
3586 ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex));
3587
3588 err = ext4_ext_get_access(handle, inode, path + depth);
3589 if (err)
3590 goto out;
3591 ext4_ext_mark_initialized(ex);
3592 ext4_ext_try_to_merge(handle, inode, path, ex);
3593 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3594 goto out;
3595 }
3596
3597 /*
3598 * four cases:
3599 * 1. split the extent into three extents.
3600 * 2. split the extent into two extents, zeroout the first half.
3601 * 3. split the extent into two extents, zeroout the second half.
3602 * 4. split the extent into two extents with out zeroout.
3603 */
3604 split_map.m_lblk = map->m_lblk;
3605 split_map.m_len = map->m_len;
3606
3607 if (max_zeroout && (allocated > map->m_len)) {
3608 if (allocated <= max_zeroout) {
3609 /* case 3 */
3610 zero_ex.ee_block =
3611 cpu_to_le32(map->m_lblk);
3612 zero_ex.ee_len = cpu_to_le16(allocated);
3613 ext4_ext_store_pblock(&zero_ex,
3614 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
3615 err = ext4_ext_zeroout(inode, &zero_ex);
3616 if (err)
3617 goto out;
3618 split_map.m_lblk = map->m_lblk;
3619 split_map.m_len = allocated;
3620 } else if (map->m_lblk - ee_block + map->m_len < max_zeroout) {
3621 /* case 2 */
3622 if (map->m_lblk != ee_block) {
3623 zero_ex.ee_block = ex->ee_block;
3624 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
3625 ee_block);
3626 ext4_ext_store_pblock(&zero_ex,
3627 ext4_ext_pblock(ex));
3628 err = ext4_ext_zeroout(inode, &zero_ex);
3629 if (err)
3630 goto out;
3631 }
3632
3633 split_map.m_lblk = ee_block;
3634 split_map.m_len = map->m_lblk - ee_block + map->m_len;
3635 allocated = map->m_len;
3636 }
3637 }
3638
3639 err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
3640 flags);
3641 if (err > 0)
3642 err = 0;
3643out:
3644 /* If we have gotten a failure, don't zero out status tree */
3645 if (!err)
3646 err = ext4_zeroout_es(inode, &zero_ex);
3647 return err ? err : allocated;
3648}
3649
3650/*
3651 * This function is called by ext4_ext_map_blocks() from
3652 * ext4_get_blocks_dio_write() when DIO to write
3653 * to an unwritten extent.
3654 *
3655 * Writing to an unwritten extent may result in splitting the unwritten
3656 * extent into multiple initialized/unwritten extents (up to three)
3657 * There are three possibilities:
3658 * a> There is no split required: Entire extent should be unwritten
3659 * b> Splits in two extents: Write is happening at either end of the extent
3660 * c> Splits in three extents: Somone is writing in middle of the extent
3661 *
3662 * This works the same way in the case of initialized -> unwritten conversion.
3663 *
3664 * One of more index blocks maybe needed if the extent tree grow after
3665 * the unwritten extent split. To prevent ENOSPC occur at the IO
3666 * complete, we need to split the unwritten extent before DIO submit
3667 * the IO. The unwritten extent called at this time will be split
3668 * into three unwritten extent(at most). After IO complete, the part
3669 * being filled will be convert to initialized by the end_io callback function
3670 * via ext4_convert_unwritten_extents().
3671 *
3672 * Returns the size of unwritten extent to be written on success.
3673 */
3674static int ext4_split_convert_extents(handle_t *handle,
3675 struct inode *inode,
3676 struct ext4_map_blocks *map,
3677 struct ext4_ext_path **ppath,
3678 int flags)
3679{
3680 struct ext4_ext_path *path = *ppath;
3681 ext4_lblk_t eof_block;
3682 ext4_lblk_t ee_block;
3683 struct ext4_extent *ex;
3684 unsigned int ee_len;
3685 int split_flag = 0, depth;
3686
3687 ext_debug("%s: inode %lu, logical block %llu, max_blocks %u\n",
3688 __func__, inode->i_ino,
3689 (unsigned long long)map->m_lblk, map->m_len);
3690
3691 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3692 inode->i_sb->s_blocksize_bits;
3693 if (eof_block < map->m_lblk + map->m_len)
3694 eof_block = map->m_lblk + map->m_len;
3695 /*
3696 * It is safe to convert extent to initialized via explicit
3697 * zeroout only if extent is fully insde i_size or new_size.
3698 */
3699 depth = ext_depth(inode);
3700 ex = path[depth].p_ext;
3701 ee_block = le32_to_cpu(ex->ee_block);
3702 ee_len = ext4_ext_get_actual_len(ex);
3703
3704 /* Convert to unwritten */
3705 if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
3706 split_flag |= EXT4_EXT_DATA_VALID1;
3707 /* Convert to initialized */
3708 } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
3709 split_flag |= ee_block + ee_len <= eof_block ?
3710 EXT4_EXT_MAY_ZEROOUT : 0;
3711 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
3712 }
3713 flags |= EXT4_GET_BLOCKS_PRE_IO;
3714 return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
3715}
3716
3717static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3718 struct inode *inode,
3719 struct ext4_map_blocks *map,
3720 struct ext4_ext_path **ppath)
3721{
3722 struct ext4_ext_path *path = *ppath;
3723 struct ext4_extent *ex;
3724 ext4_lblk_t ee_block;
3725 unsigned int ee_len;
3726 int depth;
3727 int err = 0;
3728
3729 depth = ext_depth(inode);
3730 ex = path[depth].p_ext;
3731 ee_block = le32_to_cpu(ex->ee_block);
3732 ee_len = ext4_ext_get_actual_len(ex);
3733
3734 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3735 "block %llu, max_blocks %u\n", inode->i_ino,
3736 (unsigned long long)ee_block, ee_len);
3737
3738 /* If extent is larger than requested it is a clear sign that we still
3739 * have some extent state machine issues left. So extent_split is still
3740 * required.
3741 * TODO: Once all related issues will be fixed this situation should be
3742 * illegal.
3743 */
3744 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3745#ifdef EXT4_DEBUG
3746 ext4_warning("Inode (%ld) finished: extent logical block %llu,"
3747 " len %u; IO logical block %llu, len %u",
3748 inode->i_ino, (unsigned long long)ee_block, ee_len,
3749 (unsigned long long)map->m_lblk, map->m_len);
3750#endif
3751 err = ext4_split_convert_extents(handle, inode, map, ppath,
3752 EXT4_GET_BLOCKS_CONVERT);
3753 if (err < 0)
3754 return err;
3755 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3756 if (IS_ERR(path))
3757 return PTR_ERR(path);
3758 depth = ext_depth(inode);
3759 ex = path[depth].p_ext;
3760 }
3761
3762 err = ext4_ext_get_access(handle, inode, path + depth);
3763 if (err)
3764 goto out;
3765 /* first mark the extent as initialized */
3766 ext4_ext_mark_initialized(ex);
3767
3768 /* note: ext4_ext_correct_indexes() isn't needed here because
3769 * borders are not changed
3770 */
3771 ext4_ext_try_to_merge(handle, inode, path, ex);
3772
3773 /* Mark modified extent as dirty */
3774 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3775out:
3776 ext4_ext_show_leaf(inode, path);
3777 return err;
3778}
3779
3780/*
3781 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3782 */
3783static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3784 ext4_lblk_t lblk,
3785 struct ext4_ext_path *path,
3786 unsigned int len)
3787{
3788 int i, depth;
3789 struct ext4_extent_header *eh;
3790 struct ext4_extent *last_ex;
3791
3792 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3793 return 0;
3794
3795 depth = ext_depth(inode);
3796 eh = path[depth].p_hdr;
3797
3798 /*
3799 * We're going to remove EOFBLOCKS_FL entirely in future so we
3800 * do not care for this case anymore. Simply remove the flag
3801 * if there are no extents.
3802 */
3803 if (unlikely(!eh->eh_entries))
3804 goto out;
3805 last_ex = EXT_LAST_EXTENT(eh);
3806 /*
3807 * We should clear the EOFBLOCKS_FL flag if we are writing the
3808 * last block in the last extent in the file. We test this by
3809 * first checking to see if the caller to
3810 * ext4_ext_get_blocks() was interested in the last block (or
3811 * a block beyond the last block) in the current extent. If
3812 * this turns out to be false, we can bail out from this
3813 * function immediately.
3814 */
3815 if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3816 ext4_ext_get_actual_len(last_ex))
3817 return 0;
3818 /*
3819 * If the caller does appear to be planning to write at or
3820 * beyond the end of the current extent, we then test to see
3821 * if the current extent is the last extent in the file, by
3822 * checking to make sure it was reached via the rightmost node
3823 * at each level of the tree.
3824 */
3825 for (i = depth-1; i >= 0; i--)
3826 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3827 return 0;
3828out:
3829 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3830 return ext4_mark_inode_dirty(handle, inode);
3831}
3832
3833/**
3834 * ext4_find_delalloc_range: find delayed allocated block in the given range.
3835 *
3836 * Return 1 if there is a delalloc block in the range, otherwise 0.
3837 */
3838int ext4_find_delalloc_range(struct inode *inode,
3839 ext4_lblk_t lblk_start,
3840 ext4_lblk_t lblk_end)
3841{
3842 struct extent_status es;
3843
3844 ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es);
3845 if (es.es_len == 0)
3846 return 0; /* there is no delay extent in this tree */
3847 else if (es.es_lblk <= lblk_start &&
3848 lblk_start < es.es_lblk + es.es_len)
3849 return 1;
3850 else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end)
3851 return 1;
3852 else
3853 return 0;
3854}
3855
3856int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
3857{
3858 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3859 ext4_lblk_t lblk_start, lblk_end;
3860 lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
3861 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3862
3863 return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
3864}
3865
3866/**
3867 * Determines how many complete clusters (out of those specified by the 'map')
3868 * are under delalloc and were reserved quota for.
3869 * This function is called when we are writing out the blocks that were
3870 * originally written with their allocation delayed, but then the space was
3871 * allocated using fallocate() before the delayed allocation could be resolved.
3872 * The cases to look for are:
3873 * ('=' indicated delayed allocated blocks
3874 * '-' indicates non-delayed allocated blocks)
3875 * (a) partial clusters towards beginning and/or end outside of allocated range
3876 * are not delalloc'ed.
3877 * Ex:
3878 * |----c---=|====c====|====c====|===-c----|
3879 * |++++++ allocated ++++++|
3880 * ==> 4 complete clusters in above example
3881 *
3882 * (b) partial cluster (outside of allocated range) towards either end is
3883 * marked for delayed allocation. In this case, we will exclude that
3884 * cluster.
3885 * Ex:
3886 * |----====c========|========c========|
3887 * |++++++ allocated ++++++|
3888 * ==> 1 complete clusters in above example
3889 *
3890 * Ex:
3891 * |================c================|
3892 * |++++++ allocated ++++++|
3893 * ==> 0 complete clusters in above example
3894 *
3895 * The ext4_da_update_reserve_space will be called only if we
3896 * determine here that there were some "entire" clusters that span
3897 * this 'allocated' range.
3898 * In the non-bigalloc case, this function will just end up returning num_blks
3899 * without ever calling ext4_find_delalloc_range.
3900 */
3901static unsigned int
3902get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3903 unsigned int num_blks)
3904{
3905 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3906 ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3907 ext4_lblk_t lblk_from, lblk_to, c_offset;
3908 unsigned int allocated_clusters = 0;
3909
3910 alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3911 alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3912
3913 /* max possible clusters for this allocation */
3914 allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3915
3916 trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3917
3918 /* Check towards left side */
3919 c_offset = EXT4_LBLK_COFF(sbi, lblk_start);
3920 if (c_offset) {
3921 lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start);
3922 lblk_to = lblk_from + c_offset - 1;
3923
3924 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3925 allocated_clusters--;
3926 }
3927
3928 /* Now check towards right. */
3929 c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks);
3930 if (allocated_clusters && c_offset) {
3931 lblk_from = lblk_start + num_blks;
3932 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3933
3934 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3935 allocated_clusters--;
3936 }
3937
3938 return allocated_clusters;
3939}
3940
3941static int
3942convert_initialized_extent(handle_t *handle, struct inode *inode,
3943 struct ext4_map_blocks *map,
3944 struct ext4_ext_path **ppath,
3945 unsigned int allocated)
3946{
3947 struct ext4_ext_path *path = *ppath;
3948 struct ext4_extent *ex;
3949 ext4_lblk_t ee_block;
3950 unsigned int ee_len;
3951 int depth;
3952 int err = 0;
3953
3954 /*
3955 * Make sure that the extent is no bigger than we support with
3956 * unwritten extent
3957 */
3958 if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
3959 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
3960
3961 depth = ext_depth(inode);
3962 ex = path[depth].p_ext;
3963 ee_block = le32_to_cpu(ex->ee_block);
3964 ee_len = ext4_ext_get_actual_len(ex);
3965
3966 ext_debug("%s: inode %lu, logical"
3967 "block %llu, max_blocks %u\n", __func__, inode->i_ino,
3968 (unsigned long long)ee_block, ee_len);
3969
3970 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3971 err = ext4_split_convert_extents(handle, inode, map, ppath,
3972 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
3973 if (err < 0)
3974 return err;
3975 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3976 if (IS_ERR(path))
3977 return PTR_ERR(path);
3978 depth = ext_depth(inode);
3979 ex = path[depth].p_ext;
3980 if (!ex) {
3981 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3982 (unsigned long) map->m_lblk);
3983 return -EFSCORRUPTED;
3984 }
3985 }
3986
3987 err = ext4_ext_get_access(handle, inode, path + depth);
3988 if (err)
3989 return err;
3990 /* first mark the extent as unwritten */
3991 ext4_ext_mark_unwritten(ex);
3992
3993 /* note: ext4_ext_correct_indexes() isn't needed here because
3994 * borders are not changed
3995 */
3996 ext4_ext_try_to_merge(handle, inode, path, ex);
3997
3998 /* Mark modified extent as dirty */
3999 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
4000 if (err)
4001 return err;
4002 ext4_ext_show_leaf(inode, path);
4003
4004 ext4_update_inode_fsync_trans(handle, inode, 1);
4005 err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len);
4006 if (err)
4007 return err;
4008 map->m_flags |= EXT4_MAP_UNWRITTEN;
4009 if (allocated > map->m_len)
4010 allocated = map->m_len;
4011 map->m_len = allocated;
4012 return allocated;
4013}
4014
4015static int
4016ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
4017 struct ext4_map_blocks *map,
4018 struct ext4_ext_path **ppath, int flags,
4019 unsigned int allocated, ext4_fsblk_t newblock)
4020{
4021 struct ext4_ext_path *path = *ppath;
4022 int ret = 0;
4023 int err = 0;
4024
4025 ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical "
4026 "block %llu, max_blocks %u, flags %x, allocated %u\n",
4027 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
4028 flags, allocated);
4029 ext4_ext_show_leaf(inode, path);
4030
4031 /*
4032 * When writing into unwritten space, we should not fail to
4033 * allocate metadata blocks for the new extent block if needed.
4034 */
4035 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
4036
4037 trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
4038 allocated, newblock);
4039
4040 /* get_block() before submit the IO, split the extent */
4041 if (flags & EXT4_GET_BLOCKS_PRE_IO) {
4042 ret = ext4_split_convert_extents(handle, inode, map, ppath,
4043 flags | EXT4_GET_BLOCKS_CONVERT);
4044 if (ret <= 0)
4045 goto out;
4046 map->m_flags |= EXT4_MAP_UNWRITTEN;
4047 goto out;
4048 }
4049 /* IO end_io complete, convert the filled extent to written */
4050 if (flags & EXT4_GET_BLOCKS_CONVERT) {
4051 if (flags & EXT4_GET_BLOCKS_ZERO) {
4052 if (allocated > map->m_len)
4053 allocated = map->m_len;
4054 err = ext4_issue_zeroout(inode, map->m_lblk, newblock,
4055 allocated);
4056 if (err < 0)
4057 goto out2;
4058 }
4059 ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
4060 ppath);
4061 if (ret >= 0) {
4062 ext4_update_inode_fsync_trans(handle, inode, 1);
4063 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4064 path, map->m_len);
4065 } else
4066 err = ret;
4067 map->m_flags |= EXT4_MAP_MAPPED;
4068 map->m_pblk = newblock;
4069 if (allocated > map->m_len)
4070 allocated = map->m_len;
4071 map->m_len = allocated;
4072 goto out2;
4073 }
4074 /* buffered IO case */
4075 /*
4076 * repeat fallocate creation request
4077 * we already have an unwritten extent
4078 */
4079 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
4080 map->m_flags |= EXT4_MAP_UNWRITTEN;
4081 goto map_out;
4082 }
4083
4084 /* buffered READ or buffered write_begin() lookup */
4085 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4086 /*
4087 * We have blocks reserved already. We
4088 * return allocated blocks so that delalloc
4089 * won't do block reservation for us. But
4090 * the buffer head will be unmapped so that
4091 * a read from the block returns 0s.
4092 */
4093 map->m_flags |= EXT4_MAP_UNWRITTEN;
4094 goto out1;
4095 }
4096
4097 /* buffered write, writepage time, convert*/
4098 ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags);
4099 if (ret >= 0)
4100 ext4_update_inode_fsync_trans(handle, inode, 1);
4101out:
4102 if (ret <= 0) {
4103 err = ret;
4104 goto out2;
4105 } else
4106 allocated = ret;
4107 map->m_flags |= EXT4_MAP_NEW;
4108 /*
4109 * if we allocated more blocks than requested
4110 * we need to make sure we unmap the extra block
4111 * allocated. The actual needed block will get
4112 * unmapped later when we find the buffer_head marked
4113 * new.
4114 */
4115 if (allocated > map->m_len) {
4116 clean_bdev_aliases(inode->i_sb->s_bdev, newblock + map->m_len,
4117 allocated - map->m_len);
4118 allocated = map->m_len;
4119 }
4120 map->m_len = allocated;
4121
4122 /*
4123 * If we have done fallocate with the offset that is already
4124 * delayed allocated, we would have block reservation
4125 * and quota reservation done in the delayed write path.
4126 * But fallocate would have already updated quota and block
4127 * count for this offset. So cancel these reservation
4128 */
4129 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4130 unsigned int reserved_clusters;
4131 reserved_clusters = get_reserved_cluster_alloc(inode,
4132 map->m_lblk, map->m_len);
4133 if (reserved_clusters)
4134 ext4_da_update_reserve_space(inode,
4135 reserved_clusters,
4136 0);
4137 }
4138
4139map_out:
4140 map->m_flags |= EXT4_MAP_MAPPED;
4141 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
4142 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
4143 map->m_len);
4144 if (err < 0)
4145 goto out2;
4146 }
4147out1:
4148 if (allocated > map->m_len)
4149 allocated = map->m_len;
4150 ext4_ext_show_leaf(inode, path);
4151 map->m_pblk = newblock;
4152 map->m_len = allocated;
4153out2:
4154 return err ? err : allocated;
4155}
4156
4157/*
4158 * get_implied_cluster_alloc - check to see if the requested
4159 * allocation (in the map structure) overlaps with a cluster already
4160 * allocated in an extent.
4161 * @sb The filesystem superblock structure
4162 * @map The requested lblk->pblk mapping
4163 * @ex The extent structure which might contain an implied
4164 * cluster allocation
4165 *
4166 * This function is called by ext4_ext_map_blocks() after we failed to
4167 * find blocks that were already in the inode's extent tree. Hence,
4168 * we know that the beginning of the requested region cannot overlap
4169 * the extent from the inode's extent tree. There are three cases we
4170 * want to catch. The first is this case:
4171 *
4172 * |--- cluster # N--|
4173 * |--- extent ---| |---- requested region ---|
4174 * |==========|
4175 *
4176 * The second case that we need to test for is this one:
4177 *
4178 * |--------- cluster # N ----------------|
4179 * |--- requested region --| |------- extent ----|
4180 * |=======================|
4181 *
4182 * The third case is when the requested region lies between two extents
4183 * within the same cluster:
4184 * |------------- cluster # N-------------|
4185 * |----- ex -----| |---- ex_right ----|
4186 * |------ requested region ------|
4187 * |================|
4188 *
4189 * In each of the above cases, we need to set the map->m_pblk and
4190 * map->m_len so it corresponds to the return the extent labelled as
4191 * "|====|" from cluster #N, since it is already in use for data in
4192 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
4193 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
4194 * as a new "allocated" block region. Otherwise, we will return 0 and
4195 * ext4_ext_map_blocks() will then allocate one or more new clusters
4196 * by calling ext4_mb_new_blocks().
4197 */
4198static int get_implied_cluster_alloc(struct super_block *sb,
4199 struct ext4_map_blocks *map,
4200 struct ext4_extent *ex,
4201 struct ext4_ext_path *path)
4202{
4203 struct ext4_sb_info *sbi = EXT4_SB(sb);
4204 ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4205 ext4_lblk_t ex_cluster_start, ex_cluster_end;
4206 ext4_lblk_t rr_cluster_start;
4207 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4208 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4209 unsigned short ee_len = ext4_ext_get_actual_len(ex);
4210
4211 /* The extent passed in that we are trying to match */
4212 ex_cluster_start = EXT4_B2C(sbi, ee_block);
4213 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
4214
4215 /* The requested region passed into ext4_map_blocks() */
4216 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
4217
4218 if ((rr_cluster_start == ex_cluster_end) ||
4219 (rr_cluster_start == ex_cluster_start)) {
4220 if (rr_cluster_start == ex_cluster_end)
4221 ee_start += ee_len - 1;
4222 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
4223 map->m_len = min(map->m_len,
4224 (unsigned) sbi->s_cluster_ratio - c_offset);
4225 /*
4226 * Check for and handle this case:
4227 *
4228 * |--------- cluster # N-------------|
4229 * |------- extent ----|
4230 * |--- requested region ---|
4231 * |===========|
4232 */
4233
4234 if (map->m_lblk < ee_block)
4235 map->m_len = min(map->m_len, ee_block - map->m_lblk);
4236
4237 /*
4238 * Check for the case where there is already another allocated
4239 * block to the right of 'ex' but before the end of the cluster.
4240 *
4241 * |------------- cluster # N-------------|
4242 * |----- ex -----| |---- ex_right ----|
4243 * |------ requested region ------|
4244 * |================|
4245 */
4246 if (map->m_lblk > ee_block) {
4247 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4248 map->m_len = min(map->m_len, next - map->m_lblk);
4249 }
4250
4251 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4252 return 1;
4253 }
4254
4255 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4256 return 0;
4257}
4258
4259
4260/*
4261 * Block allocation/map/preallocation routine for extents based files
4262 *
4263 *
4264 * Need to be called with
4265 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4266 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4267 *
4268 * return > 0, number of of blocks already mapped/allocated
4269 * if create == 0 and these are pre-allocated blocks
4270 * buffer head is unmapped
4271 * otherwise blocks are mapped
4272 *
4273 * return = 0, if plain look up failed (blocks have not been allocated)
4274 * buffer head is unmapped
4275 *
4276 * return < 0, error case.
4277 */
4278int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4279 struct ext4_map_blocks *map, int flags)
4280{
4281 struct ext4_ext_path *path = NULL;
4282 struct ext4_extent newex, *ex, *ex2;
4283 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4284 ext4_fsblk_t newblock = 0;
4285 int free_on_err = 0, err = 0, depth, ret;
4286 unsigned int allocated = 0, offset = 0;
4287 unsigned int allocated_clusters = 0;
4288 struct ext4_allocation_request ar;
4289 ext4_lblk_t cluster_offset;
4290 bool map_from_cluster = false;
4291
4292 ext_debug("blocks %u/%u requested for inode %lu\n",
4293 map->m_lblk, map->m_len, inode->i_ino);
4294 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4295
4296 /* find extent for this block */
4297 path = ext4_find_extent(inode, map->m_lblk, NULL, 0);
4298 if (IS_ERR(path)) {
4299 err = PTR_ERR(path);
4300 path = NULL;
4301 goto out2;
4302 }
4303
4304 depth = ext_depth(inode);
4305
4306 /*
4307 * consistent leaf must not be empty;
4308 * this situation is possible, though, _during_ tree modification;
4309 * this is why assert can't be put in ext4_find_extent()
4310 */
4311 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4312 EXT4_ERROR_INODE(inode, "bad extent address "
4313 "lblock: %lu, depth: %d pblock %lld",
4314 (unsigned long) map->m_lblk, depth,
4315 path[depth].p_block);
4316 err = -EFSCORRUPTED;
4317 goto out2;
4318 }
4319
4320 ex = path[depth].p_ext;
4321 if (ex) {
4322 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4323 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4324 unsigned short ee_len;
4325
4326
4327 /*
4328 * unwritten extents are treated as holes, except that
4329 * we split out initialized portions during a write.
4330 */
4331 ee_len = ext4_ext_get_actual_len(ex);
4332
4333 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4334
4335 /* if found extent covers block, simply return it */
4336 if (in_range(map->m_lblk, ee_block, ee_len)) {
4337 newblock = map->m_lblk - ee_block + ee_start;
4338 /* number of remaining blocks in the extent */
4339 allocated = ee_len - (map->m_lblk - ee_block);
4340 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
4341 ee_block, ee_len, newblock);
4342
4343 /*
4344 * If the extent is initialized check whether the
4345 * caller wants to convert it to unwritten.
4346 */
4347 if ((!ext4_ext_is_unwritten(ex)) &&
4348 (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
4349 allocated = convert_initialized_extent(
4350 handle, inode, map, &path,
4351 allocated);
4352 goto out2;
4353 } else if (!ext4_ext_is_unwritten(ex))
4354 goto out;
4355
4356 ret = ext4_ext_handle_unwritten_extents(
4357 handle, inode, map, &path, flags,
4358 allocated, newblock);
4359 if (ret < 0)
4360 err = ret;
4361 else
4362 allocated = ret;
4363 goto out2;
4364 }
4365 }
4366
4367 /*
4368 * requested block isn't allocated yet;
4369 * we couldn't try to create block if create flag is zero
4370 */
4371 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4372 ext4_lblk_t hole_start, hole_len;
4373
4374 hole_start = map->m_lblk;
4375 hole_len = ext4_ext_determine_hole(inode, path, &hole_start);
4376 /*
4377 * put just found gap into cache to speed up
4378 * subsequent requests
4379 */
4380 ext4_ext_put_gap_in_cache(inode, hole_start, hole_len);
4381
4382 /* Update hole_len to reflect hole size after map->m_lblk */
4383 if (hole_start != map->m_lblk)
4384 hole_len -= map->m_lblk - hole_start;
4385 map->m_pblk = 0;
4386 map->m_len = min_t(unsigned int, map->m_len, hole_len);
4387
4388 goto out2;
4389 }
4390
4391 /*
4392 * Okay, we need to do block allocation.
4393 */
4394 newex.ee_block = cpu_to_le32(map->m_lblk);
4395 cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4396
4397 /*
4398 * If we are doing bigalloc, check to see if the extent returned
4399 * by ext4_find_extent() implies a cluster we can use.
4400 */
4401 if (cluster_offset && ex &&
4402 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4403 ar.len = allocated = map->m_len;
4404 newblock = map->m_pblk;
4405 map_from_cluster = true;
4406 goto got_allocated_blocks;
4407 }
4408
4409 /* find neighbour allocated blocks */
4410 ar.lleft = map->m_lblk;
4411 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4412 if (err)
4413 goto out2;
4414 ar.lright = map->m_lblk;
4415 ex2 = NULL;
4416 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4417 if (err)
4418 goto out2;
4419
4420 /* Check if the extent after searching to the right implies a
4421 * cluster we can use. */
4422 if ((sbi->s_cluster_ratio > 1) && ex2 &&
4423 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
4424 ar.len = allocated = map->m_len;
4425 newblock = map->m_pblk;
4426 map_from_cluster = true;
4427 goto got_allocated_blocks;
4428 }
4429
4430 /*
4431 * See if request is beyond maximum number of blocks we can have in
4432 * a single extent. For an initialized extent this limit is
4433 * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
4434 * EXT_UNWRITTEN_MAX_LEN.
4435 */
4436 if (map->m_len > EXT_INIT_MAX_LEN &&
4437 !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4438 map->m_len = EXT_INIT_MAX_LEN;
4439 else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
4440 (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4441 map->m_len = EXT_UNWRITTEN_MAX_LEN;
4442
4443 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4444 newex.ee_len = cpu_to_le16(map->m_len);
4445 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4446 if (err)
4447 allocated = ext4_ext_get_actual_len(&newex);
4448 else
4449 allocated = map->m_len;
4450
4451 /* allocate new block */
4452 ar.inode = inode;
4453 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4454 ar.logical = map->m_lblk;
4455 /*
4456 * We calculate the offset from the beginning of the cluster
4457 * for the logical block number, since when we allocate a
4458 * physical cluster, the physical block should start at the
4459 * same offset from the beginning of the cluster. This is
4460 * needed so that future calls to get_implied_cluster_alloc()
4461 * work correctly.
4462 */
4463 offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4464 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4465 ar.goal -= offset;
4466 ar.logical -= offset;
4467 if (S_ISREG(inode->i_mode))
4468 ar.flags = EXT4_MB_HINT_DATA;
4469 else
4470 /* disable in-core preallocation for non-regular files */
4471 ar.flags = 0;
4472 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4473 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4474 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4475 ar.flags |= EXT4_MB_DELALLOC_RESERVED;
4476 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
4477 ar.flags |= EXT4_MB_USE_RESERVED;
4478 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4479 if (!newblock)
4480 goto out2;
4481 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4482 ar.goal, newblock, allocated);
4483 free_on_err = 1;
4484 allocated_clusters = ar.len;
4485 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4486 if (ar.len > allocated)
4487 ar.len = allocated;
4488
4489got_allocated_blocks:
4490 /* try to insert new extent into found leaf and return */
4491 ext4_ext_store_pblock(&newex, newblock + offset);
4492 newex.ee_len = cpu_to_le16(ar.len);
4493 /* Mark unwritten */
4494 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){
4495 ext4_ext_mark_unwritten(&newex);
4496 map->m_flags |= EXT4_MAP_UNWRITTEN;
4497 }
4498
4499 err = 0;
4500 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4501 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4502 path, ar.len);
4503 if (!err)
4504 err = ext4_ext_insert_extent(handle, inode, &path,
4505 &newex, flags);
4506
4507 if (err && free_on_err) {
4508 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4509 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4510 /* free data blocks we just allocated */
4511 /* not a good idea to call discard here directly,
4512 * but otherwise we'd need to call it every free() */
4513 ext4_discard_preallocations(inode);
4514 ext4_free_blocks(handle, inode, NULL, newblock,
4515 EXT4_C2B(sbi, allocated_clusters), fb_flags);
4516 goto out2;
4517 }
4518
4519 /* previous routine could use block we allocated */
4520 newblock = ext4_ext_pblock(&newex);
4521 allocated = ext4_ext_get_actual_len(&newex);
4522 if (allocated > map->m_len)
4523 allocated = map->m_len;
4524 map->m_flags |= EXT4_MAP_NEW;
4525
4526 /*
4527 * Update reserved blocks/metadata blocks after successful
4528 * block allocation which had been deferred till now.
4529 */
4530 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4531 unsigned int reserved_clusters;
4532 /*
4533 * Check how many clusters we had reserved this allocated range
4534 */
4535 reserved_clusters = get_reserved_cluster_alloc(inode,
4536 map->m_lblk, allocated);
4537 if (!map_from_cluster) {
4538 BUG_ON(allocated_clusters < reserved_clusters);
4539 if (reserved_clusters < allocated_clusters) {
4540 struct ext4_inode_info *ei = EXT4_I(inode);
4541 int reservation = allocated_clusters -
4542 reserved_clusters;
4543 /*
4544 * It seems we claimed few clusters outside of
4545 * the range of this allocation. We should give
4546 * it back to the reservation pool. This can
4547 * happen in the following case:
4548 *
4549 * * Suppose s_cluster_ratio is 4 (i.e., each
4550 * cluster has 4 blocks. Thus, the clusters
4551 * are [0-3],[4-7],[8-11]...
4552 * * First comes delayed allocation write for
4553 * logical blocks 10 & 11. Since there were no
4554 * previous delayed allocated blocks in the
4555 * range [8-11], we would reserve 1 cluster
4556 * for this write.
4557 * * Next comes write for logical blocks 3 to 8.
4558 * In this case, we will reserve 2 clusters
4559 * (for [0-3] and [4-7]; and not for [8-11] as
4560 * that range has a delayed allocated blocks.
4561 * Thus total reserved clusters now becomes 3.
4562 * * Now, during the delayed allocation writeout
4563 * time, we will first write blocks [3-8] and
4564 * allocate 3 clusters for writing these
4565 * blocks. Also, we would claim all these
4566 * three clusters above.
4567 * * Now when we come here to writeout the
4568 * blocks [10-11], we would expect to claim
4569 * the reservation of 1 cluster we had made
4570 * (and we would claim it since there are no
4571 * more delayed allocated blocks in the range
4572 * [8-11]. But our reserved cluster count had
4573 * already gone to 0.
4574 *
4575 * Thus, at the step 4 above when we determine
4576 * that there are still some unwritten delayed
4577 * allocated blocks outside of our current
4578 * block range, we should increment the
4579 * reserved clusters count so that when the
4580 * remaining blocks finally gets written, we
4581 * could claim them.
4582 */
4583 dquot_reserve_block(inode,
4584 EXT4_C2B(sbi, reservation));
4585 spin_lock(&ei->i_block_reservation_lock);
4586 ei->i_reserved_data_blocks += reservation;
4587 spin_unlock(&ei->i_block_reservation_lock);
4588 }
4589 /*
4590 * We will claim quota for all newly allocated blocks.
4591 * We're updating the reserved space *after* the
4592 * correction above so we do not accidentally free
4593 * all the metadata reservation because we might
4594 * actually need it later on.
4595 */
4596 ext4_da_update_reserve_space(inode, allocated_clusters,
4597 1);
4598 }
4599 }
4600
4601 /*
4602 * Cache the extent and update transaction to commit on fdatasync only
4603 * when it is _not_ an unwritten extent.
4604 */
4605 if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
4606 ext4_update_inode_fsync_trans(handle, inode, 1);
4607 else
4608 ext4_update_inode_fsync_trans(handle, inode, 0);
4609out:
4610 if (allocated > map->m_len)
4611 allocated = map->m_len;
4612 ext4_ext_show_leaf(inode, path);
4613 map->m_flags |= EXT4_MAP_MAPPED;
4614 map->m_pblk = newblock;
4615 map->m_len = allocated;
4616out2:
4617 ext4_ext_drop_refs(path);
4618 kfree(path);
4619
4620 trace_ext4_ext_map_blocks_exit(inode, flags, map,
4621 err ? err : allocated);
4622 return err ? err : allocated;
4623}
4624
4625int ext4_ext_truncate(handle_t *handle, struct inode *inode)
4626{
4627 struct super_block *sb = inode->i_sb;
4628 ext4_lblk_t last_block;
4629 int err = 0;
4630
4631 /*
4632 * TODO: optimization is possible here.
4633 * Probably we need not scan at all,
4634 * because page truncation is enough.
4635 */
4636
4637 /* we have to know where to truncate from in crash case */
4638 EXT4_I(inode)->i_disksize = inode->i_size;
4639 err = ext4_mark_inode_dirty(handle, inode);
4640 if (err)
4641 return err;
4642
4643 last_block = (inode->i_size + sb->s_blocksize - 1)
4644 >> EXT4_BLOCK_SIZE_BITS(sb);
4645retry:
4646 err = ext4_es_remove_extent(inode, last_block,
4647 EXT_MAX_BLOCKS - last_block);
4648 if (err == -ENOMEM) {
4649 cond_resched();
4650 congestion_wait(BLK_RW_ASYNC, HZ/50);
4651 goto retry;
4652 }
4653 if (err)
4654 return err;
4655 return ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4656}
4657
4658static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
4659 ext4_lblk_t len, loff_t new_size,
4660 int flags, int mode)
4661{
4662 struct inode *inode = file_inode(file);
4663 handle_t *handle;
4664 int ret = 0;
4665 int ret2 = 0;
4666 int retries = 0;
4667 int depth = 0;
4668 struct ext4_map_blocks map;
4669 unsigned int credits;
4670 loff_t epos;
4671
4672 BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS));
4673 map.m_lblk = offset;
4674 map.m_len = len;
4675 /*
4676 * Don't normalize the request if it can fit in one extent so
4677 * that it doesn't get unnecessarily split into multiple
4678 * extents.
4679 */
4680 if (len <= EXT_UNWRITTEN_MAX_LEN)
4681 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4682
4683 /*
4684 * credits to insert 1 extent into extent tree
4685 */
4686 credits = ext4_chunk_trans_blocks(inode, len);
4687 depth = ext_depth(inode);
4688
4689retry:
4690 while (ret >= 0 && len) {
4691 /*
4692 * Recalculate credits when extent tree depth changes.
4693 */
4694 if (depth != ext_depth(inode)) {
4695 credits = ext4_chunk_trans_blocks(inode, len);
4696 depth = ext_depth(inode);
4697 }
4698
4699 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4700 credits);
4701 if (IS_ERR(handle)) {
4702 ret = PTR_ERR(handle);
4703 break;
4704 }
4705 ret = ext4_map_blocks(handle, inode, &map, flags);
4706 if (ret <= 0) {
4707 ext4_debug("inode #%lu: block %u: len %u: "
4708 "ext4_ext_map_blocks returned %d",
4709 inode->i_ino, map.m_lblk,
4710 map.m_len, ret);
4711 ext4_mark_inode_dirty(handle, inode);
4712 ret2 = ext4_journal_stop(handle);
4713 break;
4714 }
4715 map.m_lblk += ret;
4716 map.m_len = len = len - ret;
4717 epos = (loff_t)map.m_lblk << inode->i_blkbits;
4718 inode->i_ctime = current_time(inode);
4719 if (new_size) {
4720 if (epos > new_size)
4721 epos = new_size;
4722 if (ext4_update_inode_size(inode, epos) & 0x1)
4723 inode->i_mtime = inode->i_ctime;
4724 } else {
4725 if (epos > inode->i_size)
4726 ext4_set_inode_flag(inode,
4727 EXT4_INODE_EOFBLOCKS);
4728 }
4729 ext4_mark_inode_dirty(handle, inode);
4730 ret2 = ext4_journal_stop(handle);
4731 if (ret2)
4732 break;
4733 }
4734 if (ret == -ENOSPC &&
4735 ext4_should_retry_alloc(inode->i_sb, &retries)) {
4736 ret = 0;
4737 goto retry;
4738 }
4739
4740 return ret > 0 ? ret2 : ret;
4741}
4742
4743static long ext4_zero_range(struct file *file, loff_t offset,
4744 loff_t len, int mode)
4745{
4746 struct inode *inode = file_inode(file);
4747 handle_t *handle = NULL;
4748 unsigned int max_blocks;
4749 loff_t new_size = 0;
4750 int ret = 0;
4751 int flags;
4752 int credits;
4753 int partial_begin, partial_end;
4754 loff_t start, end;
4755 ext4_lblk_t lblk;
4756 unsigned int blkbits = inode->i_blkbits;
4757
4758 trace_ext4_zero_range(inode, offset, len, mode);
4759
4760 if (!S_ISREG(inode->i_mode))
4761 return -EINVAL;
4762
4763 /* Call ext4_force_commit to flush all data in case of data=journal. */
4764 if (ext4_should_journal_data(inode)) {
4765 ret = ext4_force_commit(inode->i_sb);
4766 if (ret)
4767 return ret;
4768 }
4769
4770 /*
4771 * Round up offset. This is not fallocate, we neet to zero out
4772 * blocks, so convert interior block aligned part of the range to
4773 * unwritten and possibly manually zero out unaligned parts of the
4774 * range.
4775 */
4776 start = round_up(offset, 1 << blkbits);
4777 end = round_down((offset + len), 1 << blkbits);
4778
4779 if (start < offset || end > offset + len)
4780 return -EINVAL;
4781 partial_begin = offset & ((1 << blkbits) - 1);
4782 partial_end = (offset + len) & ((1 << blkbits) - 1);
4783
4784 lblk = start >> blkbits;
4785 max_blocks = (end >> blkbits);
4786 if (max_blocks < lblk)
4787 max_blocks = 0;
4788 else
4789 max_blocks -= lblk;
4790
4791 inode_lock(inode);
4792
4793 /*
4794 * Indirect files do not support unwritten extnets
4795 */
4796 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4797 ret = -EOPNOTSUPP;
4798 goto out_mutex;
4799 }
4800
4801 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4802 offset + len > i_size_read(inode)) {
4803 new_size = offset + len;
4804 ret = inode_newsize_ok(inode, new_size);
4805 if (ret)
4806 goto out_mutex;
4807 }
4808
4809 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4810 if (mode & FALLOC_FL_KEEP_SIZE)
4811 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4812
4813 /* Wait all existing dio workers, newcomers will block on i_mutex */
4814 ext4_inode_block_unlocked_dio(inode);
4815 inode_dio_wait(inode);
4816
4817 /* Preallocate the range including the unaligned edges */
4818 if (partial_begin || partial_end) {
4819 ret = ext4_alloc_file_blocks(file,
4820 round_down(offset, 1 << blkbits) >> blkbits,
4821 (round_up((offset + len), 1 << blkbits) -
4822 round_down(offset, 1 << blkbits)) >> blkbits,
4823 new_size, flags, mode);
4824 if (ret)
4825 goto out_dio;
4826
4827 }
4828
4829 /* Zero range excluding the unaligned edges */
4830 if (max_blocks > 0) {
4831 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
4832 EXT4_EX_NOCACHE);
4833
4834 /*
4835 * Prevent page faults from reinstantiating pages we have
4836 * released from page cache.
4837 */
4838 down_write(&EXT4_I(inode)->i_mmap_sem);
4839 ret = ext4_update_disksize_before_punch(inode, offset, len);
4840 if (ret) {
4841 up_write(&EXT4_I(inode)->i_mmap_sem);
4842 goto out_dio;
4843 }
4844 /* Now release the pages and zero block aligned part of pages */
4845 truncate_pagecache_range(inode, start, end - 1);
4846 inode->i_mtime = inode->i_ctime = current_time(inode);
4847
4848 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4849 flags, mode);
4850 up_write(&EXT4_I(inode)->i_mmap_sem);
4851 if (ret)
4852 goto out_dio;
4853 }
4854 if (!partial_begin && !partial_end)
4855 goto out_dio;
4856
4857 /*
4858 * In worst case we have to writeout two nonadjacent unwritten
4859 * blocks and update the inode
4860 */
4861 credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
4862 if (ext4_should_journal_data(inode))
4863 credits += 2;
4864 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
4865 if (IS_ERR(handle)) {
4866 ret = PTR_ERR(handle);
4867 ext4_std_error(inode->i_sb, ret);
4868 goto out_dio;
4869 }
4870
4871 inode->i_mtime = inode->i_ctime = current_time(inode);
4872 if (new_size) {
4873 ext4_update_inode_size(inode, new_size);
4874 } else {
4875 /*
4876 * Mark that we allocate beyond EOF so the subsequent truncate
4877 * can proceed even if the new size is the same as i_size.
4878 */
4879 if ((offset + len) > i_size_read(inode))
4880 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4881 }
4882 ext4_mark_inode_dirty(handle, inode);
4883
4884 /* Zero out partial block at the edges of the range */
4885 ret = ext4_zero_partial_blocks(handle, inode, offset, len);
4886
4887 if (file->f_flags & O_SYNC)
4888 ext4_handle_sync(handle);
4889
4890 ext4_journal_stop(handle);
4891out_dio:
4892 ext4_inode_resume_unlocked_dio(inode);
4893out_mutex:
4894 inode_unlock(inode);
4895 return ret;
4896}
4897
4898/*
4899 * preallocate space for a file. This implements ext4's fallocate file
4900 * operation, which gets called from sys_fallocate system call.
4901 * For block-mapped files, posix_fallocate should fall back to the method
4902 * of writing zeroes to the required new blocks (the same behavior which is
4903 * expected for file systems which do not support fallocate() system call).
4904 */
4905long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4906{
4907 struct inode *inode = file_inode(file);
4908 loff_t new_size = 0;
4909 unsigned int max_blocks;
4910 int ret = 0;
4911 int flags;
4912 ext4_lblk_t lblk;
4913 unsigned int blkbits = inode->i_blkbits;
4914
4915 /*
4916 * Encrypted inodes can't handle collapse range or insert
4917 * range since we would need to re-encrypt blocks with a
4918 * different IV or XTS tweak (which are based on the logical
4919 * block number).
4920 *
4921 * XXX It's not clear why zero range isn't working, but we'll
4922 * leave it disabled for encrypted inodes for now. This is a
4923 * bug we should fix....
4924 */
4925 if (ext4_encrypted_inode(inode) &&
4926 (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE |
4927 FALLOC_FL_ZERO_RANGE)))
4928 return -EOPNOTSUPP;
4929
4930 /* Return error if mode is not supported */
4931 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
4932 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
4933 FALLOC_FL_INSERT_RANGE))
4934 return -EOPNOTSUPP;
4935
4936 if (mode & FALLOC_FL_PUNCH_HOLE)
4937 return ext4_punch_hole(inode, offset, len);
4938
4939 ret = ext4_convert_inline_data(inode);
4940 if (ret)
4941 return ret;
4942
4943 if (mode & FALLOC_FL_COLLAPSE_RANGE)
4944 return ext4_collapse_range(inode, offset, len);
4945
4946 if (mode & FALLOC_FL_INSERT_RANGE)
4947 return ext4_insert_range(inode, offset, len);
4948
4949 if (mode & FALLOC_FL_ZERO_RANGE)
4950 return ext4_zero_range(file, offset, len, mode);
4951
4952 trace_ext4_fallocate_enter(inode, offset, len, mode);
4953 lblk = offset >> blkbits;
4954
4955 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
4956 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4957 if (mode & FALLOC_FL_KEEP_SIZE)
4958 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4959
4960 inode_lock(inode);
4961
4962 /*
4963 * We only support preallocation for extent-based files only
4964 */
4965 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4966 ret = -EOPNOTSUPP;
4967 goto out;
4968 }
4969
4970 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4971 offset + len > i_size_read(inode)) {
4972 new_size = offset + len;
4973 ret = inode_newsize_ok(inode, new_size);
4974 if (ret)
4975 goto out;
4976 }
4977
4978 /* Wait all existing dio workers, newcomers will block on i_mutex */
4979 ext4_inode_block_unlocked_dio(inode);
4980 inode_dio_wait(inode);
4981
4982 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4983 flags, mode);
4984 ext4_inode_resume_unlocked_dio(inode);
4985 if (ret)
4986 goto out;
4987
4988 if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
4989 ret = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal,
4990 EXT4_I(inode)->i_sync_tid);
4991 }
4992out:
4993 inode_unlock(inode);
4994 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4995 return ret;
4996}
4997
4998/*
4999 * This function convert a range of blocks to written extents
5000 * The caller of this function will pass the start offset and the size.
5001 * all unwritten extents within this range will be converted to
5002 * written extents.
5003 *
5004 * This function is called from the direct IO end io call back
5005 * function, to convert the fallocated extents after IO is completed.
5006 * Returns 0 on success.
5007 */
5008int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
5009 loff_t offset, ssize_t len)
5010{
5011 unsigned int max_blocks;
5012 int ret = 0;
5013 int ret2 = 0;
5014 struct ext4_map_blocks map;
5015 unsigned int credits, blkbits = inode->i_blkbits;
5016
5017 map.m_lblk = offset >> blkbits;
5018 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
5019
5020 /*
5021 * This is somewhat ugly but the idea is clear: When transaction is
5022 * reserved, everything goes into it. Otherwise we rather start several
5023 * smaller transactions for conversion of each extent separately.
5024 */
5025 if (handle) {
5026 handle = ext4_journal_start_reserved(handle,
5027 EXT4_HT_EXT_CONVERT);
5028 if (IS_ERR(handle))
5029 return PTR_ERR(handle);
5030 credits = 0;
5031 } else {
5032 /*
5033 * credits to insert 1 extent into extent tree
5034 */
5035 credits = ext4_chunk_trans_blocks(inode, max_blocks);
5036 }
5037 while (ret >= 0 && ret < max_blocks) {
5038 map.m_lblk += ret;
5039 map.m_len = (max_blocks -= ret);
5040 if (credits) {
5041 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
5042 credits);
5043 if (IS_ERR(handle)) {
5044 ret = PTR_ERR(handle);
5045 break;
5046 }
5047 }
5048 ret = ext4_map_blocks(handle, inode, &map,
5049 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
5050 if (ret <= 0)
5051 ext4_warning(inode->i_sb,
5052 "inode #%lu: block %u: len %u: "
5053 "ext4_ext_map_blocks returned %d",
5054 inode->i_ino, map.m_lblk,
5055 map.m_len, ret);
5056 ext4_mark_inode_dirty(handle, inode);
5057 if (credits)
5058 ret2 = ext4_journal_stop(handle);
5059 if (ret <= 0 || ret2)
5060 break;
5061 }
5062 if (!credits)
5063 ret2 = ext4_journal_stop(handle);
5064 return ret > 0 ? ret2 : ret;
5065}
5066
5067/*
5068 * If newes is not existing extent (newes->ec_pblk equals zero) find
5069 * delayed extent at start of newes and update newes accordingly and
5070 * return start of the next delayed extent.
5071 *
5072 * If newes is existing extent (newes->ec_pblk is not equal zero)
5073 * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
5074 * extent found. Leave newes unmodified.
5075 */
5076static int ext4_find_delayed_extent(struct inode *inode,
5077 struct extent_status *newes)
5078{
5079 struct extent_status es;
5080 ext4_lblk_t block, next_del;
5081
5082 if (newes->es_pblk == 0) {
5083 ext4_es_find_delayed_extent_range(inode, newes->es_lblk,
5084 newes->es_lblk + newes->es_len - 1, &es);
5085
5086 /*
5087 * No extent in extent-tree contains block @newes->es_pblk,
5088 * then the block may stay in 1)a hole or 2)delayed-extent.
5089 */
5090 if (es.es_len == 0)
5091 /* A hole found. */
5092 return 0;
5093
5094 if (es.es_lblk > newes->es_lblk) {
5095 /* A hole found. */
5096 newes->es_len = min(es.es_lblk - newes->es_lblk,
5097 newes->es_len);
5098 return 0;
5099 }
5100
5101 newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
5102 }
5103
5104 block = newes->es_lblk + newes->es_len;
5105 ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es);
5106 if (es.es_len == 0)
5107 next_del = EXT_MAX_BLOCKS;
5108 else
5109 next_del = es.es_lblk;
5110
5111 return next_del;
5112}
5113/* fiemap flags we can handle specified here */
5114#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
5115
5116static int ext4_xattr_fiemap(struct inode *inode,
5117 struct fiemap_extent_info *fieinfo)
5118{
5119 __u64 physical = 0;
5120 __u64 length;
5121 __u32 flags = FIEMAP_EXTENT_LAST;
5122 int blockbits = inode->i_sb->s_blocksize_bits;
5123 int error = 0;
5124
5125 /* in-inode? */
5126 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
5127 struct ext4_iloc iloc;
5128 int offset; /* offset of xattr in inode */
5129
5130 error = ext4_get_inode_loc(inode, &iloc);
5131 if (error)
5132 return error;
5133 physical = (__u64)iloc.bh->b_blocknr << blockbits;
5134 offset = EXT4_GOOD_OLD_INODE_SIZE +
5135 EXT4_I(inode)->i_extra_isize;
5136 physical += offset;
5137 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
5138 flags |= FIEMAP_EXTENT_DATA_INLINE;
5139 brelse(iloc.bh);
5140 } else { /* external block */
5141 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
5142 length = inode->i_sb->s_blocksize;
5143 }
5144
5145 if (physical)
5146 error = fiemap_fill_next_extent(fieinfo, 0, physical,
5147 length, flags);
5148 return (error < 0 ? error : 0);
5149}
5150
5151int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
5152 __u64 start, __u64 len)
5153{
5154 ext4_lblk_t start_blk;
5155 int error = 0;
5156
5157 if (ext4_has_inline_data(inode)) {
5158 int has_inline = 1;
5159
5160 error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
5161 start, len);
5162
5163 if (has_inline)
5164 return error;
5165 }
5166
5167 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
5168 error = ext4_ext_precache(inode);
5169 if (error)
5170 return error;
5171 }
5172
5173 /* fallback to generic here if not in extents fmt */
5174 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
5175 return generic_block_fiemap(inode, fieinfo, start, len,
5176 ext4_get_block);
5177
5178 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
5179 return -EBADR;
5180
5181 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
5182 error = ext4_xattr_fiemap(inode, fieinfo);
5183 } else {
5184 ext4_lblk_t len_blks;
5185 __u64 last_blk;
5186
5187 start_blk = start >> inode->i_sb->s_blocksize_bits;
5188 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
5189 if (last_blk >= EXT_MAX_BLOCKS)
5190 last_blk = EXT_MAX_BLOCKS-1;
5191 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
5192
5193 /*
5194 * Walk the extent tree gathering extent information
5195 * and pushing extents back to the user.
5196 */
5197 error = ext4_fill_fiemap_extents(inode, start_blk,
5198 len_blks, fieinfo);
5199 }
5200 return error;
5201}
5202
5203/*
5204 * ext4_access_path:
5205 * Function to access the path buffer for marking it dirty.
5206 * It also checks if there are sufficient credits left in the journal handle
5207 * to update path.
5208 */
5209static int
5210ext4_access_path(handle_t *handle, struct inode *inode,
5211 struct ext4_ext_path *path)
5212{
5213 int credits, err;
5214
5215 if (!ext4_handle_valid(handle))
5216 return 0;
5217
5218 /*
5219 * Check if need to extend journal credits
5220 * 3 for leaf, sb, and inode plus 2 (bmap and group
5221 * descriptor) for each block group; assume two block
5222 * groups
5223 */
5224 if (handle->h_buffer_credits < 7) {
5225 credits = ext4_writepage_trans_blocks(inode);
5226 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
5227 /* EAGAIN is success */
5228 if (err && err != -EAGAIN)
5229 return err;
5230 }
5231
5232 err = ext4_ext_get_access(handle, inode, path);
5233 return err;
5234}
5235
5236/*
5237 * ext4_ext_shift_path_extents:
5238 * Shift the extents of a path structure lying between path[depth].p_ext
5239 * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
5240 * if it is right shift or left shift operation.
5241 */
5242static int
5243ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
5244 struct inode *inode, handle_t *handle,
5245 enum SHIFT_DIRECTION SHIFT)
5246{
5247 int depth, err = 0;
5248 struct ext4_extent *ex_start, *ex_last;
5249 bool update = 0;
5250 depth = path->p_depth;
5251
5252 while (depth >= 0) {
5253 if (depth == path->p_depth) {
5254 ex_start = path[depth].p_ext;
5255 if (!ex_start)
5256 return -EFSCORRUPTED;
5257
5258 ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
5259
5260 err = ext4_access_path(handle, inode, path + depth);
5261 if (err)
5262 goto out;
5263
5264 if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr))
5265 update = 1;
5266
5267 while (ex_start <= ex_last) {
5268 if (SHIFT == SHIFT_LEFT) {
5269 le32_add_cpu(&ex_start->ee_block,
5270 -shift);
5271 /* Try to merge to the left. */
5272 if ((ex_start >
5273 EXT_FIRST_EXTENT(path[depth].p_hdr))
5274 &&
5275 ext4_ext_try_to_merge_right(inode,
5276 path, ex_start - 1))
5277 ex_last--;
5278 else
5279 ex_start++;
5280 } else {
5281 le32_add_cpu(&ex_last->ee_block, shift);
5282 ext4_ext_try_to_merge_right(inode, path,
5283 ex_last);
5284 ex_last--;
5285 }
5286 }
5287 err = ext4_ext_dirty(handle, inode, path + depth);
5288 if (err)
5289 goto out;
5290
5291 if (--depth < 0 || !update)
5292 break;
5293 }
5294
5295 /* Update index too */
5296 err = ext4_access_path(handle, inode, path + depth);
5297 if (err)
5298 goto out;
5299
5300 if (SHIFT == SHIFT_LEFT)
5301 le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
5302 else
5303 le32_add_cpu(&path[depth].p_idx->ei_block, shift);
5304 err = ext4_ext_dirty(handle, inode, path + depth);
5305 if (err)
5306 goto out;
5307
5308 /* we are done if current index is not a starting index */
5309 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
5310 break;
5311
5312 depth--;
5313 }
5314
5315out:
5316 return err;
5317}
5318
5319/*
5320 * ext4_ext_shift_extents:
5321 * All the extents which lies in the range from @start to the last allocated
5322 * block for the @inode are shifted either towards left or right (depending
5323 * upon @SHIFT) by @shift blocks.
5324 * On success, 0 is returned, error otherwise.
5325 */
5326static int
5327ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
5328 ext4_lblk_t start, ext4_lblk_t shift,
5329 enum SHIFT_DIRECTION SHIFT)
5330{
5331 struct ext4_ext_path *path;
5332 int ret = 0, depth;
5333 struct ext4_extent *extent;
5334 ext4_lblk_t stop, *iterator, ex_start, ex_end;
5335
5336 /* Let path point to the last extent */
5337 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
5338 EXT4_EX_NOCACHE);
5339 if (IS_ERR(path))
5340 return PTR_ERR(path);
5341
5342 depth = path->p_depth;
5343 extent = path[depth].p_ext;
5344 if (!extent)
5345 goto out;
5346
5347 stop = le32_to_cpu(extent->ee_block);
5348
5349 /*
5350 * In case of left shift, Don't start shifting extents until we make
5351 * sure the hole is big enough to accommodate the shift.
5352 */
5353 if (SHIFT == SHIFT_LEFT) {
5354 path = ext4_find_extent(inode, start - 1, &path,
5355 EXT4_EX_NOCACHE);
5356 if (IS_ERR(path))
5357 return PTR_ERR(path);
5358 depth = path->p_depth;
5359 extent = path[depth].p_ext;
5360 if (extent) {
5361 ex_start = le32_to_cpu(extent->ee_block);
5362 ex_end = le32_to_cpu(extent->ee_block) +
5363 ext4_ext_get_actual_len(extent);
5364 } else {
5365 ex_start = 0;
5366 ex_end = 0;
5367 }
5368
5369 if ((start == ex_start && shift > ex_start) ||
5370 (shift > start - ex_end)) {
5371 ext4_ext_drop_refs(path);
5372 kfree(path);
5373 return -EINVAL;
5374 }
5375 }
5376
5377 /*
5378 * In case of left shift, iterator points to start and it is increased
5379 * till we reach stop. In case of right shift, iterator points to stop
5380 * and it is decreased till we reach start.
5381 */
5382 if (SHIFT == SHIFT_LEFT)
5383 iterator = &start;
5384 else
5385 iterator = &stop;
5386
5387 /*
5388 * Its safe to start updating extents. Start and stop are unsigned, so
5389 * in case of right shift if extent with 0 block is reached, iterator
5390 * becomes NULL to indicate the end of the loop.
5391 */
5392 while (iterator && start <= stop) {
5393 path = ext4_find_extent(inode, *iterator, &path,
5394 EXT4_EX_NOCACHE);
5395 if (IS_ERR(path))
5396 return PTR_ERR(path);
5397 depth = path->p_depth;
5398 extent = path[depth].p_ext;
5399 if (!extent) {
5400 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
5401 (unsigned long) *iterator);
5402 return -EFSCORRUPTED;
5403 }
5404 if (SHIFT == SHIFT_LEFT && *iterator >
5405 le32_to_cpu(extent->ee_block)) {
5406 /* Hole, move to the next extent */
5407 if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
5408 path[depth].p_ext++;
5409 } else {
5410 *iterator = ext4_ext_next_allocated_block(path);
5411 continue;
5412 }
5413 }
5414
5415 if (SHIFT == SHIFT_LEFT) {
5416 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5417 *iterator = le32_to_cpu(extent->ee_block) +
5418 ext4_ext_get_actual_len(extent);
5419 } else {
5420 extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
5421 if (le32_to_cpu(extent->ee_block) > 0)
5422 *iterator = le32_to_cpu(extent->ee_block) - 1;
5423 else
5424 /* Beginning is reached, end of the loop */
5425 iterator = NULL;
5426 /* Update path extent in case we need to stop */
5427 while (le32_to_cpu(extent->ee_block) < start)
5428 extent++;
5429 path[depth].p_ext = extent;
5430 }
5431 ret = ext4_ext_shift_path_extents(path, shift, inode,
5432 handle, SHIFT);
5433 if (ret)
5434 break;
5435 }
5436out:
5437 ext4_ext_drop_refs(path);
5438 kfree(path);
5439 return ret;
5440}
5441
5442/*
5443 * ext4_collapse_range:
5444 * This implements the fallocate's collapse range functionality for ext4
5445 * Returns: 0 and non-zero on error.
5446 */
5447int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
5448{
5449 struct super_block *sb = inode->i_sb;
5450 ext4_lblk_t punch_start, punch_stop;
5451 handle_t *handle;
5452 unsigned int credits;
5453 loff_t new_size, ioffset;
5454 int ret;
5455
5456 /*
5457 * We need to test this early because xfstests assumes that a
5458 * collapse range of (0, 1) will return EOPNOTSUPP if the file
5459 * system does not support collapse range.
5460 */
5461 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5462 return -EOPNOTSUPP;
5463
5464 /* Collapse range works only on fs block size aligned offsets. */
5465 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
5466 len & (EXT4_CLUSTER_SIZE(sb) - 1))
5467 return -EINVAL;
5468
5469 if (!S_ISREG(inode->i_mode))
5470 return -EINVAL;
5471
5472 trace_ext4_collapse_range(inode, offset, len);
5473
5474 punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5475 punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb);
5476
5477 /* Call ext4_force_commit to flush all data in case of data=journal. */
5478 if (ext4_should_journal_data(inode)) {
5479 ret = ext4_force_commit(inode->i_sb);
5480 if (ret)
5481 return ret;
5482 }
5483
5484 inode_lock(inode);
5485 /*
5486 * There is no need to overlap collapse range with EOF, in which case
5487 * it is effectively a truncate operation
5488 */
5489 if (offset + len >= i_size_read(inode)) {
5490 ret = -EINVAL;
5491 goto out_mutex;
5492 }
5493
5494 /* Currently just for extent based files */
5495 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5496 ret = -EOPNOTSUPP;
5497 goto out_mutex;
5498 }
5499
5500 /* Wait for existing dio to complete */
5501 ext4_inode_block_unlocked_dio(inode);
5502 inode_dio_wait(inode);
5503
5504 /*
5505 * Prevent page faults from reinstantiating pages we have released from
5506 * page cache.
5507 */
5508 down_write(&EXT4_I(inode)->i_mmap_sem);
5509 /*
5510 * Need to round down offset to be aligned with page size boundary
5511 * for page size > block size.
5512 */
5513 ioffset = round_down(offset, PAGE_SIZE);
5514 /*
5515 * Write tail of the last page before removed range since it will get
5516 * removed from the page cache below.
5517 */
5518 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, offset);
5519 if (ret)
5520 goto out_mmap;
5521 /*
5522 * Write data that will be shifted to preserve them when discarding
5523 * page cache below. We are also protected from pages becoming dirty
5524 * by i_mmap_sem.
5525 */
5526 ret = filemap_write_and_wait_range(inode->i_mapping, offset + len,
5527 LLONG_MAX);
5528 if (ret)
5529 goto out_mmap;
5530 truncate_pagecache(inode, ioffset);
5531
5532 credits = ext4_writepage_trans_blocks(inode);
5533 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5534 if (IS_ERR(handle)) {
5535 ret = PTR_ERR(handle);
5536 goto out_mmap;
5537 }
5538
5539 down_write(&EXT4_I(inode)->i_data_sem);
5540 ext4_discard_preallocations(inode);
5541
5542 ret = ext4_es_remove_extent(inode, punch_start,
5543 EXT_MAX_BLOCKS - punch_start);
5544 if (ret) {
5545 up_write(&EXT4_I(inode)->i_data_sem);
5546 goto out_stop;
5547 }
5548
5549 ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
5550 if (ret) {
5551 up_write(&EXT4_I(inode)->i_data_sem);
5552 goto out_stop;
5553 }
5554 ext4_discard_preallocations(inode);
5555
5556 ret = ext4_ext_shift_extents(inode, handle, punch_stop,
5557 punch_stop - punch_start, SHIFT_LEFT);
5558 if (ret) {
5559 up_write(&EXT4_I(inode)->i_data_sem);
5560 goto out_stop;
5561 }
5562
5563 new_size = i_size_read(inode) - len;
5564 i_size_write(inode, new_size);
5565 EXT4_I(inode)->i_disksize = new_size;
5566
5567 up_write(&EXT4_I(inode)->i_data_sem);
5568 if (IS_SYNC(inode))
5569 ext4_handle_sync(handle);
5570 inode->i_mtime = inode->i_ctime = current_time(inode);
5571 ext4_mark_inode_dirty(handle, inode);
5572
5573out_stop:
5574 ext4_journal_stop(handle);
5575out_mmap:
5576 up_write(&EXT4_I(inode)->i_mmap_sem);
5577 ext4_inode_resume_unlocked_dio(inode);
5578out_mutex:
5579 inode_unlock(inode);
5580 return ret;
5581}
5582
5583/*
5584 * ext4_insert_range:
5585 * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
5586 * The data blocks starting from @offset to the EOF are shifted by @len
5587 * towards right to create a hole in the @inode. Inode size is increased
5588 * by len bytes.
5589 * Returns 0 on success, error otherwise.
5590 */
5591int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
5592{
5593 struct super_block *sb = inode->i_sb;
5594 handle_t *handle;
5595 struct ext4_ext_path *path;
5596 struct ext4_extent *extent;
5597 ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
5598 unsigned int credits, ee_len;
5599 int ret = 0, depth, split_flag = 0;
5600 loff_t ioffset;
5601
5602 /*
5603 * We need to test this early because xfstests assumes that an
5604 * insert range of (0, 1) will return EOPNOTSUPP if the file
5605 * system does not support insert range.
5606 */
5607 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5608 return -EOPNOTSUPP;
5609
5610 /* Insert range works only on fs block size aligned offsets. */
5611 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
5612 len & (EXT4_CLUSTER_SIZE(sb) - 1))
5613 return -EINVAL;
5614
5615 if (!S_ISREG(inode->i_mode))
5616 return -EOPNOTSUPP;
5617
5618 trace_ext4_insert_range(inode, offset, len);
5619
5620 offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5621 len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
5622
5623 /* Call ext4_force_commit to flush all data in case of data=journal */
5624 if (ext4_should_journal_data(inode)) {
5625 ret = ext4_force_commit(inode->i_sb);
5626 if (ret)
5627 return ret;
5628 }
5629
5630 inode_lock(inode);
5631 /* Currently just for extent based files */
5632 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5633 ret = -EOPNOTSUPP;
5634 goto out_mutex;
5635 }
5636
5637 /* Check for wrap through zero */
5638 if (inode->i_size + len > inode->i_sb->s_maxbytes) {
5639 ret = -EFBIG;
5640 goto out_mutex;
5641 }
5642
5643 /* Offset should be less than i_size */
5644 if (offset >= i_size_read(inode)) {
5645 ret = -EINVAL;
5646 goto out_mutex;
5647 }
5648
5649 /* Wait for existing dio to complete */
5650 ext4_inode_block_unlocked_dio(inode);
5651 inode_dio_wait(inode);
5652
5653 /*
5654 * Prevent page faults from reinstantiating pages we have released from
5655 * page cache.
5656 */
5657 down_write(&EXT4_I(inode)->i_mmap_sem);
5658 /*
5659 * Need to round down to align start offset to page size boundary
5660 * for page size > block size.
5661 */
5662 ioffset = round_down(offset, PAGE_SIZE);
5663 /* Write out all dirty pages */
5664 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5665 LLONG_MAX);
5666 if (ret)
5667 goto out_mmap;
5668 truncate_pagecache(inode, ioffset);
5669
5670 credits = ext4_writepage_trans_blocks(inode);
5671 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5672 if (IS_ERR(handle)) {
5673 ret = PTR_ERR(handle);
5674 goto out_mmap;
5675 }
5676
5677 /* Expand file to avoid data loss if there is error while shifting */
5678 inode->i_size += len;
5679 EXT4_I(inode)->i_disksize += len;
5680 inode->i_mtime = inode->i_ctime = current_time(inode);
5681 ret = ext4_mark_inode_dirty(handle, inode);
5682 if (ret)
5683 goto out_stop;
5684
5685 down_write(&EXT4_I(inode)->i_data_sem);
5686 ext4_discard_preallocations(inode);
5687
5688 path = ext4_find_extent(inode, offset_lblk, NULL, 0);
5689 if (IS_ERR(path)) {
5690 up_write(&EXT4_I(inode)->i_data_sem);
5691 goto out_stop;
5692 }
5693
5694 depth = ext_depth(inode);
5695 extent = path[depth].p_ext;
5696 if (extent) {
5697 ee_start_lblk = le32_to_cpu(extent->ee_block);
5698 ee_len = ext4_ext_get_actual_len(extent);
5699
5700 /*
5701 * If offset_lblk is not the starting block of extent, split
5702 * the extent @offset_lblk
5703 */
5704 if ((offset_lblk > ee_start_lblk) &&
5705 (offset_lblk < (ee_start_lblk + ee_len))) {
5706 if (ext4_ext_is_unwritten(extent))
5707 split_flag = EXT4_EXT_MARK_UNWRIT1 |
5708 EXT4_EXT_MARK_UNWRIT2;
5709 ret = ext4_split_extent_at(handle, inode, &path,
5710 offset_lblk, split_flag,
5711 EXT4_EX_NOCACHE |
5712 EXT4_GET_BLOCKS_PRE_IO |
5713 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5714 }
5715
5716 ext4_ext_drop_refs(path);
5717 kfree(path);
5718 if (ret < 0) {
5719 up_write(&EXT4_I(inode)->i_data_sem);
5720 goto out_stop;
5721 }
5722 } else {
5723 ext4_ext_drop_refs(path);
5724 kfree(path);
5725 }
5726
5727 ret = ext4_es_remove_extent(inode, offset_lblk,
5728 EXT_MAX_BLOCKS - offset_lblk);
5729 if (ret) {
5730 up_write(&EXT4_I(inode)->i_data_sem);
5731 goto out_stop;
5732 }
5733
5734 /*
5735 * if offset_lblk lies in a hole which is at start of file, use
5736 * ee_start_lblk to shift extents
5737 */
5738 ret = ext4_ext_shift_extents(inode, handle,
5739 ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk,
5740 len_lblk, SHIFT_RIGHT);
5741
5742 up_write(&EXT4_I(inode)->i_data_sem);
5743 if (IS_SYNC(inode))
5744 ext4_handle_sync(handle);
5745
5746out_stop:
5747 ext4_journal_stop(handle);
5748out_mmap:
5749 up_write(&EXT4_I(inode)->i_mmap_sem);
5750 ext4_inode_resume_unlocked_dio(inode);
5751out_mutex:
5752 inode_unlock(inode);
5753 return ret;
5754}
5755
5756/**
5757 * ext4_swap_extents - Swap extents between two inodes
5758 *
5759 * @inode1: First inode
5760 * @inode2: Second inode
5761 * @lblk1: Start block for first inode
5762 * @lblk2: Start block for second inode
5763 * @count: Number of blocks to swap
5764 * @mark_unwritten: Mark second inode's extents as unwritten after swap
5765 * @erp: Pointer to save error value
5766 *
5767 * This helper routine does exactly what is promise "swap extents". All other
5768 * stuff such as page-cache locking consistency, bh mapping consistency or
5769 * extent's data copying must be performed by caller.
5770 * Locking:
5771 * i_mutex is held for both inodes
5772 * i_data_sem is locked for write for both inodes
5773 * Assumptions:
5774 * All pages from requested range are locked for both inodes
5775 */
5776int
5777ext4_swap_extents(handle_t *handle, struct inode *inode1,
5778 struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
5779 ext4_lblk_t count, int unwritten, int *erp)
5780{
5781 struct ext4_ext_path *path1 = NULL;
5782 struct ext4_ext_path *path2 = NULL;
5783 int replaced_count = 0;
5784
5785 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
5786 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
5787 BUG_ON(!inode_is_locked(inode1));
5788 BUG_ON(!inode_is_locked(inode2));
5789
5790 *erp = ext4_es_remove_extent(inode1, lblk1, count);
5791 if (unlikely(*erp))
5792 return 0;
5793 *erp = ext4_es_remove_extent(inode2, lblk2, count);
5794 if (unlikely(*erp))
5795 return 0;
5796
5797 while (count) {
5798 struct ext4_extent *ex1, *ex2, tmp_ex;
5799 ext4_lblk_t e1_blk, e2_blk;
5800 int e1_len, e2_len, len;
5801 int split = 0;
5802
5803 path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE);
5804 if (IS_ERR(path1)) {
5805 *erp = PTR_ERR(path1);
5806 path1 = NULL;
5807 finish:
5808 count = 0;
5809 goto repeat;
5810 }
5811 path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE);
5812 if (IS_ERR(path2)) {
5813 *erp = PTR_ERR(path2);
5814 path2 = NULL;
5815 goto finish;
5816 }
5817 ex1 = path1[path1->p_depth].p_ext;
5818 ex2 = path2[path2->p_depth].p_ext;
5819 /* Do we have somthing to swap ? */
5820 if (unlikely(!ex2 || !ex1))
5821 goto finish;
5822
5823 e1_blk = le32_to_cpu(ex1->ee_block);
5824 e2_blk = le32_to_cpu(ex2->ee_block);
5825 e1_len = ext4_ext_get_actual_len(ex1);
5826 e2_len = ext4_ext_get_actual_len(ex2);
5827
5828 /* Hole handling */
5829 if (!in_range(lblk1, e1_blk, e1_len) ||
5830 !in_range(lblk2, e2_blk, e2_len)) {
5831 ext4_lblk_t next1, next2;
5832
5833 /* if hole after extent, then go to next extent */
5834 next1 = ext4_ext_next_allocated_block(path1);
5835 next2 = ext4_ext_next_allocated_block(path2);
5836 /* If hole before extent, then shift to that extent */
5837 if (e1_blk > lblk1)
5838 next1 = e1_blk;
5839 if (e2_blk > lblk2)
5840 next2 = e1_blk;
5841 /* Do we have something to swap */
5842 if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
5843 goto finish;
5844 /* Move to the rightest boundary */
5845 len = next1 - lblk1;
5846 if (len < next2 - lblk2)
5847 len = next2 - lblk2;
5848 if (len > count)
5849 len = count;
5850 lblk1 += len;
5851 lblk2 += len;
5852 count -= len;
5853 goto repeat;
5854 }
5855
5856 /* Prepare left boundary */
5857 if (e1_blk < lblk1) {
5858 split = 1;
5859 *erp = ext4_force_split_extent_at(handle, inode1,
5860 &path1, lblk1, 0);
5861 if (unlikely(*erp))
5862 goto finish;
5863 }
5864 if (e2_blk < lblk2) {
5865 split = 1;
5866 *erp = ext4_force_split_extent_at(handle, inode2,
5867 &path2, lblk2, 0);
5868 if (unlikely(*erp))
5869 goto finish;
5870 }
5871 /* ext4_split_extent_at() may result in leaf extent split,
5872 * path must to be revalidated. */
5873 if (split)
5874 goto repeat;
5875
5876 /* Prepare right boundary */
5877 len = count;
5878 if (len > e1_blk + e1_len - lblk1)
5879 len = e1_blk + e1_len - lblk1;
5880 if (len > e2_blk + e2_len - lblk2)
5881 len = e2_blk + e2_len - lblk2;
5882
5883 if (len != e1_len) {
5884 split = 1;
5885 *erp = ext4_force_split_extent_at(handle, inode1,
5886 &path1, lblk1 + len, 0);
5887 if (unlikely(*erp))
5888 goto finish;
5889 }
5890 if (len != e2_len) {
5891 split = 1;
5892 *erp = ext4_force_split_extent_at(handle, inode2,
5893 &path2, lblk2 + len, 0);
5894 if (*erp)
5895 goto finish;
5896 }
5897 /* ext4_split_extent_at() may result in leaf extent split,
5898 * path must to be revalidated. */
5899 if (split)
5900 goto repeat;
5901
5902 BUG_ON(e2_len != e1_len);
5903 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
5904 if (unlikely(*erp))
5905 goto finish;
5906 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
5907 if (unlikely(*erp))
5908 goto finish;
5909
5910 /* Both extents are fully inside boundaries. Swap it now */
5911 tmp_ex = *ex1;
5912 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
5913 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
5914 ex1->ee_len = cpu_to_le16(e2_len);
5915 ex2->ee_len = cpu_to_le16(e1_len);
5916 if (unwritten)
5917 ext4_ext_mark_unwritten(ex2);
5918 if (ext4_ext_is_unwritten(&tmp_ex))
5919 ext4_ext_mark_unwritten(ex1);
5920
5921 ext4_ext_try_to_merge(handle, inode2, path2, ex2);
5922 ext4_ext_try_to_merge(handle, inode1, path1, ex1);
5923 *erp = ext4_ext_dirty(handle, inode2, path2 +
5924 path2->p_depth);
5925 if (unlikely(*erp))
5926 goto finish;
5927 *erp = ext4_ext_dirty(handle, inode1, path1 +
5928 path1->p_depth);
5929 /*
5930 * Looks scarry ah..? second inode already points to new blocks,
5931 * and it was successfully dirtied. But luckily error may happen
5932 * only due to journal error, so full transaction will be
5933 * aborted anyway.
5934 */
5935 if (unlikely(*erp))
5936 goto finish;
5937 lblk1 += len;
5938 lblk2 += len;
5939 replaced_count += len;
5940 count -= len;
5941
5942 repeat:
5943 ext4_ext_drop_refs(path1);
5944 kfree(path1);
5945 ext4_ext_drop_refs(path2);
5946 kfree(path2);
5947 path1 = path2 = NULL;
5948 }
5949 return replaced_count;
5950}
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 Licens
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 <linux/falloc.h>
41#include <asm/uaccess.h>
42#include <linux/fiemap.h>
43#include "ext4_jbd2.h"
44
45#include <trace/events/ext4.h>
46
47/*
48 * used by extent splitting.
49 */
50#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
51 due to ENOSPC */
52#define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */
53#define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */
54
55static __le32 ext4_extent_block_csum(struct inode *inode,
56 struct ext4_extent_header *eh)
57{
58 struct ext4_inode_info *ei = EXT4_I(inode);
59 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
60 __u32 csum;
61
62 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
63 EXT4_EXTENT_TAIL_OFFSET(eh));
64 return cpu_to_le32(csum);
65}
66
67static int ext4_extent_block_csum_verify(struct inode *inode,
68 struct ext4_extent_header *eh)
69{
70 struct ext4_extent_tail *et;
71
72 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
73 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
74 return 1;
75
76 et = find_ext4_extent_tail(eh);
77 if (et->et_checksum != ext4_extent_block_csum(inode, eh))
78 return 0;
79 return 1;
80}
81
82static void ext4_extent_block_csum_set(struct inode *inode,
83 struct ext4_extent_header *eh)
84{
85 struct ext4_extent_tail *et;
86
87 if (!EXT4_HAS_RO_COMPAT_FEATURE(inode->i_sb,
88 EXT4_FEATURE_RO_COMPAT_METADATA_CSUM))
89 return;
90
91 et = find_ext4_extent_tail(eh);
92 et->et_checksum = ext4_extent_block_csum(inode, eh);
93}
94
95static int ext4_split_extent(handle_t *handle,
96 struct inode *inode,
97 struct ext4_ext_path *path,
98 struct ext4_map_blocks *map,
99 int split_flag,
100 int flags);
101
102static int ext4_split_extent_at(handle_t *handle,
103 struct inode *inode,
104 struct ext4_ext_path *path,
105 ext4_lblk_t split,
106 int split_flag,
107 int flags);
108
109static int ext4_ext_truncate_extend_restart(handle_t *handle,
110 struct inode *inode,
111 int needed)
112{
113 int err;
114
115 if (!ext4_handle_valid(handle))
116 return 0;
117 if (handle->h_buffer_credits > needed)
118 return 0;
119 err = ext4_journal_extend(handle, needed);
120 if (err <= 0)
121 return err;
122 err = ext4_truncate_restart_trans(handle, inode, needed);
123 if (err == 0)
124 err = -EAGAIN;
125
126 return err;
127}
128
129/*
130 * could return:
131 * - EROFS
132 * - ENOMEM
133 */
134static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
135 struct ext4_ext_path *path)
136{
137 if (path->p_bh) {
138 /* path points to block */
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 */
152#define ext4_ext_dirty(handle, inode, path) \
153 __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
154static int __ext4_ext_dirty(const char *where, unsigned int line,
155 handle_t *handle, struct inode *inode,
156 struct ext4_ext_path *path)
157{
158 int err;
159 if (path->p_bh) {
160 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
161 /* path points to block */
162 err = __ext4_handle_dirty_metadata(where, line, handle,
163 inode, path->p_bh);
164 } else {
165 /* path points to leaf/index in inode body */
166 err = ext4_mark_inode_dirty(handle, inode);
167 }
168 return err;
169}
170
171static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
172 struct ext4_ext_path *path,
173 ext4_lblk_t block)
174{
175 if (path) {
176 int depth = path->p_depth;
177 struct ext4_extent *ex;
178
179 /*
180 * Try to predict block placement assuming that we are
181 * filling in a file which will eventually be
182 * non-sparse --- i.e., in the case of libbfd writing
183 * an ELF object sections out-of-order but in a way
184 * the eventually results in a contiguous object or
185 * executable file, or some database extending a table
186 * space file. However, this is actually somewhat
187 * non-ideal if we are writing a sparse file such as
188 * qemu or KVM writing a raw image file that is going
189 * to stay fairly sparse, since it will end up
190 * fragmenting the file system's free space. Maybe we
191 * should have some hueristics or some way to allow
192 * userspace to pass a hint to file system,
193 * especially if the latter case turns out to be
194 * common.
195 */
196 ex = path[depth].p_ext;
197 if (ex) {
198 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
199 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
200
201 if (block > ext_block)
202 return ext_pblk + (block - ext_block);
203 else
204 return ext_pblk - (ext_block - block);
205 }
206
207 /* it looks like index is empty;
208 * try to find starting block from index itself */
209 if (path[depth].p_bh)
210 return path[depth].p_bh->b_blocknr;
211 }
212
213 /* OK. use inode's group */
214 return ext4_inode_to_goal_block(inode);
215}
216
217/*
218 * Allocation for a meta data block
219 */
220static ext4_fsblk_t
221ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
222 struct ext4_ext_path *path,
223 struct ext4_extent *ex, int *err, unsigned int flags)
224{
225 ext4_fsblk_t goal, newblock;
226
227 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
228 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
229 NULL, err);
230 return newblock;
231}
232
233static inline int ext4_ext_space_block(struct inode *inode, int check)
234{
235 int size;
236
237 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
238 / sizeof(struct ext4_extent);
239#ifdef AGGRESSIVE_TEST
240 if (!check && size > 6)
241 size = 6;
242#endif
243 return size;
244}
245
246static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
247{
248 int size;
249
250 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
251 / sizeof(struct ext4_extent_idx);
252#ifdef AGGRESSIVE_TEST
253 if (!check && size > 5)
254 size = 5;
255#endif
256 return size;
257}
258
259static inline int ext4_ext_space_root(struct inode *inode, int check)
260{
261 int size;
262
263 size = sizeof(EXT4_I(inode)->i_data);
264 size -= sizeof(struct ext4_extent_header);
265 size /= sizeof(struct ext4_extent);
266#ifdef AGGRESSIVE_TEST
267 if (!check && size > 3)
268 size = 3;
269#endif
270 return size;
271}
272
273static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
274{
275 int size;
276
277 size = sizeof(EXT4_I(inode)->i_data);
278 size -= sizeof(struct ext4_extent_header);
279 size /= sizeof(struct ext4_extent_idx);
280#ifdef AGGRESSIVE_TEST
281 if (!check && size > 4)
282 size = 4;
283#endif
284 return size;
285}
286
287/*
288 * Calculate the number of metadata blocks needed
289 * to allocate @blocks
290 * Worse case is one block per extent
291 */
292int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
293{
294 struct ext4_inode_info *ei = EXT4_I(inode);
295 int idxs;
296
297 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
298 / sizeof(struct ext4_extent_idx));
299
300 /*
301 * If the new delayed allocation block is contiguous with the
302 * previous da block, it can share index blocks with the
303 * previous block, so we only need to allocate a new index
304 * block every idxs leaf blocks. At ldxs**2 blocks, we need
305 * an additional index block, and at ldxs**3 blocks, yet
306 * another index blocks.
307 */
308 if (ei->i_da_metadata_calc_len &&
309 ei->i_da_metadata_calc_last_lblock+1 == lblock) {
310 int num = 0;
311
312 if ((ei->i_da_metadata_calc_len % idxs) == 0)
313 num++;
314 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
315 num++;
316 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
317 num++;
318 ei->i_da_metadata_calc_len = 0;
319 } else
320 ei->i_da_metadata_calc_len++;
321 ei->i_da_metadata_calc_last_lblock++;
322 return num;
323 }
324
325 /*
326 * In the worst case we need a new set of index blocks at
327 * every level of the inode's extent tree.
328 */
329 ei->i_da_metadata_calc_len = 1;
330 ei->i_da_metadata_calc_last_lblock = lblock;
331 return ext_depth(inode) + 1;
332}
333
334static int
335ext4_ext_max_entries(struct inode *inode, int depth)
336{
337 int max;
338
339 if (depth == ext_depth(inode)) {
340 if (depth == 0)
341 max = ext4_ext_space_root(inode, 1);
342 else
343 max = ext4_ext_space_root_idx(inode, 1);
344 } else {
345 if (depth == 0)
346 max = ext4_ext_space_block(inode, 1);
347 else
348 max = ext4_ext_space_block_idx(inode, 1);
349 }
350
351 return max;
352}
353
354static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
355{
356 ext4_fsblk_t block = ext4_ext_pblock(ext);
357 int len = ext4_ext_get_actual_len(ext);
358
359 if (len == 0)
360 return 0;
361 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
362}
363
364static int ext4_valid_extent_idx(struct inode *inode,
365 struct ext4_extent_idx *ext_idx)
366{
367 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
368
369 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
370}
371
372static int ext4_valid_extent_entries(struct inode *inode,
373 struct ext4_extent_header *eh,
374 int depth)
375{
376 unsigned short entries;
377 if (eh->eh_entries == 0)
378 return 1;
379
380 entries = le16_to_cpu(eh->eh_entries);
381
382 if (depth == 0) {
383 /* leaf entries */
384 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
385 while (entries) {
386 if (!ext4_valid_extent(inode, ext))
387 return 0;
388 ext++;
389 entries--;
390 }
391 } else {
392 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
393 while (entries) {
394 if (!ext4_valid_extent_idx(inode, ext_idx))
395 return 0;
396 ext_idx++;
397 entries--;
398 }
399 }
400 return 1;
401}
402
403static int __ext4_ext_check(const char *function, unsigned int line,
404 struct inode *inode, struct ext4_extent_header *eh,
405 int depth)
406{
407 const char *error_msg;
408 int max = 0;
409
410 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
411 error_msg = "invalid magic";
412 goto corrupted;
413 }
414 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
415 error_msg = "unexpected eh_depth";
416 goto corrupted;
417 }
418 if (unlikely(eh->eh_max == 0)) {
419 error_msg = "invalid eh_max";
420 goto corrupted;
421 }
422 max = ext4_ext_max_entries(inode, depth);
423 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
424 error_msg = "too large eh_max";
425 goto corrupted;
426 }
427 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
428 error_msg = "invalid eh_entries";
429 goto corrupted;
430 }
431 if (!ext4_valid_extent_entries(inode, eh, depth)) {
432 error_msg = "invalid extent entries";
433 goto corrupted;
434 }
435 /* Verify checksum on non-root extent tree nodes */
436 if (ext_depth(inode) != depth &&
437 !ext4_extent_block_csum_verify(inode, eh)) {
438 error_msg = "extent tree corrupted";
439 goto corrupted;
440 }
441 return 0;
442
443corrupted:
444 ext4_error_inode(inode, function, line, 0,
445 "bad header/extent: %s - magic %x, "
446 "entries %u, max %u(%u), depth %u(%u)",
447 error_msg, le16_to_cpu(eh->eh_magic),
448 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
449 max, le16_to_cpu(eh->eh_depth), depth);
450
451 return -EIO;
452}
453
454#define ext4_ext_check(inode, eh, depth) \
455 __ext4_ext_check(__func__, __LINE__, inode, eh, depth)
456
457int ext4_ext_check_inode(struct inode *inode)
458{
459 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
460}
461
462static int __ext4_ext_check_block(const char *function, unsigned int line,
463 struct inode *inode,
464 struct ext4_extent_header *eh,
465 int depth,
466 struct buffer_head *bh)
467{
468 int ret;
469
470 if (buffer_verified(bh))
471 return 0;
472 ret = ext4_ext_check(inode, eh, depth);
473 if (ret)
474 return ret;
475 set_buffer_verified(bh);
476 return ret;
477}
478
479#define ext4_ext_check_block(inode, eh, depth, bh) \
480 __ext4_ext_check_block(__func__, __LINE__, inode, eh, depth, bh)
481
482#ifdef EXT_DEBUG
483static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
484{
485 int k, l = path->p_depth;
486
487 ext_debug("path:");
488 for (k = 0; k <= l; k++, path++) {
489 if (path->p_idx) {
490 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
491 ext4_idx_pblock(path->p_idx));
492 } else if (path->p_ext) {
493 ext_debug(" %d:[%d]%d:%llu ",
494 le32_to_cpu(path->p_ext->ee_block),
495 ext4_ext_is_uninitialized(path->p_ext),
496 ext4_ext_get_actual_len(path->p_ext),
497 ext4_ext_pblock(path->p_ext));
498 } else
499 ext_debug(" []");
500 }
501 ext_debug("\n");
502}
503
504static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
505{
506 int depth = ext_depth(inode);
507 struct ext4_extent_header *eh;
508 struct ext4_extent *ex;
509 int i;
510
511 if (!path)
512 return;
513
514 eh = path[depth].p_hdr;
515 ex = EXT_FIRST_EXTENT(eh);
516
517 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
518
519 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
520 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
521 ext4_ext_is_uninitialized(ex),
522 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
523 }
524 ext_debug("\n");
525}
526
527static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
528 ext4_fsblk_t newblock, int level)
529{
530 int depth = ext_depth(inode);
531 struct ext4_extent *ex;
532
533 if (depth != level) {
534 struct ext4_extent_idx *idx;
535 idx = path[level].p_idx;
536 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
537 ext_debug("%d: move %d:%llu in new index %llu\n", level,
538 le32_to_cpu(idx->ei_block),
539 ext4_idx_pblock(idx),
540 newblock);
541 idx++;
542 }
543
544 return;
545 }
546
547 ex = path[depth].p_ext;
548 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
549 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
550 le32_to_cpu(ex->ee_block),
551 ext4_ext_pblock(ex),
552 ext4_ext_is_uninitialized(ex),
553 ext4_ext_get_actual_len(ex),
554 newblock);
555 ex++;
556 }
557}
558
559#else
560#define ext4_ext_show_path(inode, path)
561#define ext4_ext_show_leaf(inode, path)
562#define ext4_ext_show_move(inode, path, newblock, level)
563#endif
564
565void ext4_ext_drop_refs(struct ext4_ext_path *path)
566{
567 int depth = path->p_depth;
568 int i;
569
570 for (i = 0; i <= depth; i++, path++)
571 if (path->p_bh) {
572 brelse(path->p_bh);
573 path->p_bh = NULL;
574 }
575}
576
577/*
578 * ext4_ext_binsearch_idx:
579 * binary search for the closest index of the given block
580 * the header must be checked before calling this
581 */
582static void
583ext4_ext_binsearch_idx(struct inode *inode,
584 struct ext4_ext_path *path, ext4_lblk_t block)
585{
586 struct ext4_extent_header *eh = path->p_hdr;
587 struct ext4_extent_idx *r, *l, *m;
588
589
590 ext_debug("binsearch for %u(idx): ", block);
591
592 l = EXT_FIRST_INDEX(eh) + 1;
593 r = EXT_LAST_INDEX(eh);
594 while (l <= r) {
595 m = l + (r - l) / 2;
596 if (block < le32_to_cpu(m->ei_block))
597 r = m - 1;
598 else
599 l = m + 1;
600 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
601 m, le32_to_cpu(m->ei_block),
602 r, le32_to_cpu(r->ei_block));
603 }
604
605 path->p_idx = l - 1;
606 ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
607 ext4_idx_pblock(path->p_idx));
608
609#ifdef CHECK_BINSEARCH
610 {
611 struct ext4_extent_idx *chix, *ix;
612 int k;
613
614 chix = ix = EXT_FIRST_INDEX(eh);
615 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
616 if (k != 0 &&
617 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
618 printk(KERN_DEBUG "k=%d, ix=0x%p, "
619 "first=0x%p\n", k,
620 ix, EXT_FIRST_INDEX(eh));
621 printk(KERN_DEBUG "%u <= %u\n",
622 le32_to_cpu(ix->ei_block),
623 le32_to_cpu(ix[-1].ei_block));
624 }
625 BUG_ON(k && le32_to_cpu(ix->ei_block)
626 <= le32_to_cpu(ix[-1].ei_block));
627 if (block < le32_to_cpu(ix->ei_block))
628 break;
629 chix = ix;
630 }
631 BUG_ON(chix != path->p_idx);
632 }
633#endif
634
635}
636
637/*
638 * ext4_ext_binsearch:
639 * binary search for closest extent of the given block
640 * the header must be checked before calling this
641 */
642static void
643ext4_ext_binsearch(struct inode *inode,
644 struct ext4_ext_path *path, ext4_lblk_t block)
645{
646 struct ext4_extent_header *eh = path->p_hdr;
647 struct ext4_extent *r, *l, *m;
648
649 if (eh->eh_entries == 0) {
650 /*
651 * this leaf is empty:
652 * we get such a leaf in split/add case
653 */
654 return;
655 }
656
657 ext_debug("binsearch for %u: ", block);
658
659 l = EXT_FIRST_EXTENT(eh) + 1;
660 r = EXT_LAST_EXTENT(eh);
661
662 while (l <= r) {
663 m = l + (r - l) / 2;
664 if (block < le32_to_cpu(m->ee_block))
665 r = m - 1;
666 else
667 l = m + 1;
668 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
669 m, le32_to_cpu(m->ee_block),
670 r, le32_to_cpu(r->ee_block));
671 }
672
673 path->p_ext = l - 1;
674 ext_debug(" -> %d:%llu:[%d]%d ",
675 le32_to_cpu(path->p_ext->ee_block),
676 ext4_ext_pblock(path->p_ext),
677 ext4_ext_is_uninitialized(path->p_ext),
678 ext4_ext_get_actual_len(path->p_ext));
679
680#ifdef CHECK_BINSEARCH
681 {
682 struct ext4_extent *chex, *ex;
683 int k;
684
685 chex = ex = EXT_FIRST_EXTENT(eh);
686 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
687 BUG_ON(k && le32_to_cpu(ex->ee_block)
688 <= le32_to_cpu(ex[-1].ee_block));
689 if (block < le32_to_cpu(ex->ee_block))
690 break;
691 chex = ex;
692 }
693 BUG_ON(chex != path->p_ext);
694 }
695#endif
696
697}
698
699int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
700{
701 struct ext4_extent_header *eh;
702
703 eh = ext_inode_hdr(inode);
704 eh->eh_depth = 0;
705 eh->eh_entries = 0;
706 eh->eh_magic = EXT4_EXT_MAGIC;
707 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
708 ext4_mark_inode_dirty(handle, inode);
709 ext4_ext_invalidate_cache(inode);
710 return 0;
711}
712
713struct ext4_ext_path *
714ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
715 struct ext4_ext_path *path)
716{
717 struct ext4_extent_header *eh;
718 struct buffer_head *bh;
719 short int depth, i, ppos = 0, alloc = 0;
720
721 eh = ext_inode_hdr(inode);
722 depth = ext_depth(inode);
723
724 /* account possible depth increase */
725 if (!path) {
726 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
727 GFP_NOFS);
728 if (!path)
729 return ERR_PTR(-ENOMEM);
730 alloc = 1;
731 }
732 path[0].p_hdr = eh;
733 path[0].p_bh = NULL;
734
735 i = depth;
736 /* walk through the tree */
737 while (i) {
738 ext_debug("depth %d: num %d, max %d\n",
739 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
740
741 ext4_ext_binsearch_idx(inode, path + ppos, block);
742 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
743 path[ppos].p_depth = i;
744 path[ppos].p_ext = NULL;
745
746 bh = sb_getblk(inode->i_sb, path[ppos].p_block);
747 if (unlikely(!bh))
748 goto err;
749 if (!bh_uptodate_or_lock(bh)) {
750 trace_ext4_ext_load_extent(inode, block,
751 path[ppos].p_block);
752 if (bh_submit_read(bh) < 0) {
753 put_bh(bh);
754 goto err;
755 }
756 }
757 eh = ext_block_hdr(bh);
758 ppos++;
759 if (unlikely(ppos > depth)) {
760 put_bh(bh);
761 EXT4_ERROR_INODE(inode,
762 "ppos %d > depth %d", ppos, depth);
763 goto err;
764 }
765 path[ppos].p_bh = bh;
766 path[ppos].p_hdr = eh;
767 i--;
768
769 if (ext4_ext_check_block(inode, eh, i, bh))
770 goto err;
771 }
772
773 path[ppos].p_depth = i;
774 path[ppos].p_ext = NULL;
775 path[ppos].p_idx = NULL;
776
777 /* find extent */
778 ext4_ext_binsearch(inode, path + ppos, block);
779 /* if not an empty leaf */
780 if (path[ppos].p_ext)
781 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
782
783 ext4_ext_show_path(inode, path);
784
785 return path;
786
787err:
788 ext4_ext_drop_refs(path);
789 if (alloc)
790 kfree(path);
791 return ERR_PTR(-EIO);
792}
793
794/*
795 * ext4_ext_insert_index:
796 * insert new index [@logical;@ptr] into the block at @curp;
797 * check where to insert: before @curp or after @curp
798 */
799static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
800 struct ext4_ext_path *curp,
801 int logical, ext4_fsblk_t ptr)
802{
803 struct ext4_extent_idx *ix;
804 int len, err;
805
806 err = ext4_ext_get_access(handle, inode, curp);
807 if (err)
808 return err;
809
810 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
811 EXT4_ERROR_INODE(inode,
812 "logical %d == ei_block %d!",
813 logical, le32_to_cpu(curp->p_idx->ei_block));
814 return -EIO;
815 }
816
817 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
818 >= le16_to_cpu(curp->p_hdr->eh_max))) {
819 EXT4_ERROR_INODE(inode,
820 "eh_entries %d >= eh_max %d!",
821 le16_to_cpu(curp->p_hdr->eh_entries),
822 le16_to_cpu(curp->p_hdr->eh_max));
823 return -EIO;
824 }
825
826 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
827 /* insert after */
828 ext_debug("insert new index %d after: %llu\n", logical, ptr);
829 ix = curp->p_idx + 1;
830 } else {
831 /* insert before */
832 ext_debug("insert new index %d before: %llu\n", logical, ptr);
833 ix = curp->p_idx;
834 }
835
836 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
837 BUG_ON(len < 0);
838 if (len > 0) {
839 ext_debug("insert new index %d: "
840 "move %d indices from 0x%p to 0x%p\n",
841 logical, len, ix, ix + 1);
842 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
843 }
844
845 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
846 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
847 return -EIO;
848 }
849
850 ix->ei_block = cpu_to_le32(logical);
851 ext4_idx_store_pblock(ix, ptr);
852 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
853
854 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
855 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
856 return -EIO;
857 }
858
859 err = ext4_ext_dirty(handle, inode, curp);
860 ext4_std_error(inode->i_sb, err);
861
862 return err;
863}
864
865/*
866 * ext4_ext_split:
867 * inserts new subtree into the path, using free index entry
868 * at depth @at:
869 * - allocates all needed blocks (new leaf and all intermediate index blocks)
870 * - makes decision where to split
871 * - moves remaining extents and index entries (right to the split point)
872 * into the newly allocated blocks
873 * - initializes subtree
874 */
875static int ext4_ext_split(handle_t *handle, struct inode *inode,
876 unsigned int flags,
877 struct ext4_ext_path *path,
878 struct ext4_extent *newext, int at)
879{
880 struct buffer_head *bh = NULL;
881 int depth = ext_depth(inode);
882 struct ext4_extent_header *neh;
883 struct ext4_extent_idx *fidx;
884 int i = at, k, m, a;
885 ext4_fsblk_t newblock, oldblock;
886 __le32 border;
887 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
888 int err = 0;
889
890 /* make decision: where to split? */
891 /* FIXME: now decision is simplest: at current extent */
892
893 /* if current leaf will be split, then we should use
894 * border from split point */
895 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
896 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
897 return -EIO;
898 }
899 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
900 border = path[depth].p_ext[1].ee_block;
901 ext_debug("leaf will be split."
902 " next leaf starts at %d\n",
903 le32_to_cpu(border));
904 } else {
905 border = newext->ee_block;
906 ext_debug("leaf will be added."
907 " next leaf starts at %d\n",
908 le32_to_cpu(border));
909 }
910
911 /*
912 * If error occurs, then we break processing
913 * and mark filesystem read-only. index won't
914 * be inserted and tree will be in consistent
915 * state. Next mount will repair buffers too.
916 */
917
918 /*
919 * Get array to track all allocated blocks.
920 * We need this to handle errors and free blocks
921 * upon them.
922 */
923 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
924 if (!ablocks)
925 return -ENOMEM;
926
927 /* allocate all needed blocks */
928 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
929 for (a = 0; a < depth - at; a++) {
930 newblock = ext4_ext_new_meta_block(handle, inode, path,
931 newext, &err, flags);
932 if (newblock == 0)
933 goto cleanup;
934 ablocks[a] = newblock;
935 }
936
937 /* initialize new leaf */
938 newblock = ablocks[--a];
939 if (unlikely(newblock == 0)) {
940 EXT4_ERROR_INODE(inode, "newblock == 0!");
941 err = -EIO;
942 goto cleanup;
943 }
944 bh = sb_getblk(inode->i_sb, newblock);
945 if (!bh) {
946 err = -EIO;
947 goto cleanup;
948 }
949 lock_buffer(bh);
950
951 err = ext4_journal_get_create_access(handle, bh);
952 if (err)
953 goto cleanup;
954
955 neh = ext_block_hdr(bh);
956 neh->eh_entries = 0;
957 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
958 neh->eh_magic = EXT4_EXT_MAGIC;
959 neh->eh_depth = 0;
960
961 /* move remainder of path[depth] to the new leaf */
962 if (unlikely(path[depth].p_hdr->eh_entries !=
963 path[depth].p_hdr->eh_max)) {
964 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
965 path[depth].p_hdr->eh_entries,
966 path[depth].p_hdr->eh_max);
967 err = -EIO;
968 goto cleanup;
969 }
970 /* start copy from next extent */
971 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
972 ext4_ext_show_move(inode, path, newblock, depth);
973 if (m) {
974 struct ext4_extent *ex;
975 ex = EXT_FIRST_EXTENT(neh);
976 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
977 le16_add_cpu(&neh->eh_entries, m);
978 }
979
980 ext4_extent_block_csum_set(inode, neh);
981 set_buffer_uptodate(bh);
982 unlock_buffer(bh);
983
984 err = ext4_handle_dirty_metadata(handle, inode, bh);
985 if (err)
986 goto cleanup;
987 brelse(bh);
988 bh = NULL;
989
990 /* correct old leaf */
991 if (m) {
992 err = ext4_ext_get_access(handle, inode, path + depth);
993 if (err)
994 goto cleanup;
995 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
996 err = ext4_ext_dirty(handle, inode, path + depth);
997 if (err)
998 goto cleanup;
999
1000 }
1001
1002 /* create intermediate indexes */
1003 k = depth - at - 1;
1004 if (unlikely(k < 0)) {
1005 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1006 err = -EIO;
1007 goto cleanup;
1008 }
1009 if (k)
1010 ext_debug("create %d intermediate indices\n", k);
1011 /* insert new index into current index block */
1012 /* current depth stored in i var */
1013 i = depth - 1;
1014 while (k--) {
1015 oldblock = newblock;
1016 newblock = ablocks[--a];
1017 bh = sb_getblk(inode->i_sb, newblock);
1018 if (!bh) {
1019 err = -EIO;
1020 goto cleanup;
1021 }
1022 lock_buffer(bh);
1023
1024 err = ext4_journal_get_create_access(handle, bh);
1025 if (err)
1026 goto cleanup;
1027
1028 neh = ext_block_hdr(bh);
1029 neh->eh_entries = cpu_to_le16(1);
1030 neh->eh_magic = EXT4_EXT_MAGIC;
1031 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1032 neh->eh_depth = cpu_to_le16(depth - i);
1033 fidx = EXT_FIRST_INDEX(neh);
1034 fidx->ei_block = border;
1035 ext4_idx_store_pblock(fidx, oldblock);
1036
1037 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1038 i, newblock, le32_to_cpu(border), oldblock);
1039
1040 /* move remainder of path[i] to the new index block */
1041 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1042 EXT_LAST_INDEX(path[i].p_hdr))) {
1043 EXT4_ERROR_INODE(inode,
1044 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1045 le32_to_cpu(path[i].p_ext->ee_block));
1046 err = -EIO;
1047 goto cleanup;
1048 }
1049 /* start copy indexes */
1050 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1051 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1052 EXT_MAX_INDEX(path[i].p_hdr));
1053 ext4_ext_show_move(inode, path, newblock, i);
1054 if (m) {
1055 memmove(++fidx, path[i].p_idx,
1056 sizeof(struct ext4_extent_idx) * m);
1057 le16_add_cpu(&neh->eh_entries, m);
1058 }
1059 ext4_extent_block_csum_set(inode, neh);
1060 set_buffer_uptodate(bh);
1061 unlock_buffer(bh);
1062
1063 err = ext4_handle_dirty_metadata(handle, inode, bh);
1064 if (err)
1065 goto cleanup;
1066 brelse(bh);
1067 bh = NULL;
1068
1069 /* correct old index */
1070 if (m) {
1071 err = ext4_ext_get_access(handle, inode, path + i);
1072 if (err)
1073 goto cleanup;
1074 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1075 err = ext4_ext_dirty(handle, inode, path + i);
1076 if (err)
1077 goto cleanup;
1078 }
1079
1080 i--;
1081 }
1082
1083 /* insert new index */
1084 err = ext4_ext_insert_index(handle, inode, path + at,
1085 le32_to_cpu(border), newblock);
1086
1087cleanup:
1088 if (bh) {
1089 if (buffer_locked(bh))
1090 unlock_buffer(bh);
1091 brelse(bh);
1092 }
1093
1094 if (err) {
1095 /* free all allocated blocks in error case */
1096 for (i = 0; i < depth; i++) {
1097 if (!ablocks[i])
1098 continue;
1099 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1100 EXT4_FREE_BLOCKS_METADATA);
1101 }
1102 }
1103 kfree(ablocks);
1104
1105 return err;
1106}
1107
1108/*
1109 * ext4_ext_grow_indepth:
1110 * implements tree growing procedure:
1111 * - allocates new block
1112 * - moves top-level data (index block or leaf) into the new block
1113 * - initializes new top-level, creating index that points to the
1114 * just created block
1115 */
1116static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1117 unsigned int flags,
1118 struct ext4_extent *newext)
1119{
1120 struct ext4_extent_header *neh;
1121 struct buffer_head *bh;
1122 ext4_fsblk_t newblock;
1123 int err = 0;
1124
1125 newblock = ext4_ext_new_meta_block(handle, inode, NULL,
1126 newext, &err, flags);
1127 if (newblock == 0)
1128 return err;
1129
1130 bh = sb_getblk(inode->i_sb, newblock);
1131 if (!bh) {
1132 err = -EIO;
1133 ext4_std_error(inode->i_sb, err);
1134 return err;
1135 }
1136 lock_buffer(bh);
1137
1138 err = ext4_journal_get_create_access(handle, bh);
1139 if (err) {
1140 unlock_buffer(bh);
1141 goto out;
1142 }
1143
1144 /* move top-level index/leaf into new block */
1145 memmove(bh->b_data, EXT4_I(inode)->i_data,
1146 sizeof(EXT4_I(inode)->i_data));
1147
1148 /* set size of new block */
1149 neh = ext_block_hdr(bh);
1150 /* old root could have indexes or leaves
1151 * so calculate e_max right way */
1152 if (ext_depth(inode))
1153 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1154 else
1155 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1156 neh->eh_magic = EXT4_EXT_MAGIC;
1157 ext4_extent_block_csum_set(inode, neh);
1158 set_buffer_uptodate(bh);
1159 unlock_buffer(bh);
1160
1161 err = ext4_handle_dirty_metadata(handle, inode, bh);
1162 if (err)
1163 goto out;
1164
1165 /* Update top-level index: num,max,pointer */
1166 neh = ext_inode_hdr(inode);
1167 neh->eh_entries = cpu_to_le16(1);
1168 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1169 if (neh->eh_depth == 0) {
1170 /* Root extent block becomes index block */
1171 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1172 EXT_FIRST_INDEX(neh)->ei_block =
1173 EXT_FIRST_EXTENT(neh)->ee_block;
1174 }
1175 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1176 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1177 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1178 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1179
1180 neh->eh_depth = cpu_to_le16(le16_to_cpu(neh->eh_depth) + 1);
1181 ext4_mark_inode_dirty(handle, inode);
1182out:
1183 brelse(bh);
1184
1185 return err;
1186}
1187
1188/*
1189 * ext4_ext_create_new_leaf:
1190 * finds empty index and adds new leaf.
1191 * if no free index is found, then it requests in-depth growing.
1192 */
1193static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1194 unsigned int flags,
1195 struct ext4_ext_path *path,
1196 struct ext4_extent *newext)
1197{
1198 struct ext4_ext_path *curp;
1199 int depth, i, err = 0;
1200
1201repeat:
1202 i = depth = ext_depth(inode);
1203
1204 /* walk up to the tree and look for free index entry */
1205 curp = path + depth;
1206 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1207 i--;
1208 curp--;
1209 }
1210
1211 /* we use already allocated block for index block,
1212 * so subsequent data blocks should be contiguous */
1213 if (EXT_HAS_FREE_INDEX(curp)) {
1214 /* if we found index with free entry, then use that
1215 * entry: create all needed subtree and add new leaf */
1216 err = ext4_ext_split(handle, inode, flags, path, newext, i);
1217 if (err)
1218 goto out;
1219
1220 /* refill path */
1221 ext4_ext_drop_refs(path);
1222 path = ext4_ext_find_extent(inode,
1223 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1224 path);
1225 if (IS_ERR(path))
1226 err = PTR_ERR(path);
1227 } else {
1228 /* tree is full, time to grow in depth */
1229 err = ext4_ext_grow_indepth(handle, inode, flags, newext);
1230 if (err)
1231 goto out;
1232
1233 /* refill path */
1234 ext4_ext_drop_refs(path);
1235 path = ext4_ext_find_extent(inode,
1236 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1237 path);
1238 if (IS_ERR(path)) {
1239 err = PTR_ERR(path);
1240 goto out;
1241 }
1242
1243 /*
1244 * only first (depth 0 -> 1) produces free space;
1245 * in all other cases we have to split the grown tree
1246 */
1247 depth = ext_depth(inode);
1248 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1249 /* now we need to split */
1250 goto repeat;
1251 }
1252 }
1253
1254out:
1255 return err;
1256}
1257
1258/*
1259 * search the closest allocated block to the left for *logical
1260 * and returns it at @logical + it's physical address at @phys
1261 * if *logical is the smallest allocated block, the function
1262 * returns 0 at @phys
1263 * return value contains 0 (success) or error code
1264 */
1265static int ext4_ext_search_left(struct inode *inode,
1266 struct ext4_ext_path *path,
1267 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1268{
1269 struct ext4_extent_idx *ix;
1270 struct ext4_extent *ex;
1271 int depth, ee_len;
1272
1273 if (unlikely(path == NULL)) {
1274 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1275 return -EIO;
1276 }
1277 depth = path->p_depth;
1278 *phys = 0;
1279
1280 if (depth == 0 && path->p_ext == NULL)
1281 return 0;
1282
1283 /* usually extent in the path covers blocks smaller
1284 * then *logical, but it can be that extent is the
1285 * first one in the file */
1286
1287 ex = path[depth].p_ext;
1288 ee_len = ext4_ext_get_actual_len(ex);
1289 if (*logical < le32_to_cpu(ex->ee_block)) {
1290 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1291 EXT4_ERROR_INODE(inode,
1292 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1293 *logical, le32_to_cpu(ex->ee_block));
1294 return -EIO;
1295 }
1296 while (--depth >= 0) {
1297 ix = path[depth].p_idx;
1298 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1299 EXT4_ERROR_INODE(inode,
1300 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1301 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1302 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1303 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1304 depth);
1305 return -EIO;
1306 }
1307 }
1308 return 0;
1309 }
1310
1311 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1312 EXT4_ERROR_INODE(inode,
1313 "logical %d < ee_block %d + ee_len %d!",
1314 *logical, le32_to_cpu(ex->ee_block), ee_len);
1315 return -EIO;
1316 }
1317
1318 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1319 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1320 return 0;
1321}
1322
1323/*
1324 * search the closest allocated block to the right for *logical
1325 * and returns it at @logical + it's physical address at @phys
1326 * if *logical is the largest allocated block, the function
1327 * returns 0 at @phys
1328 * return value contains 0 (success) or error code
1329 */
1330static int ext4_ext_search_right(struct inode *inode,
1331 struct ext4_ext_path *path,
1332 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1333 struct ext4_extent **ret_ex)
1334{
1335 struct buffer_head *bh = NULL;
1336 struct ext4_extent_header *eh;
1337 struct ext4_extent_idx *ix;
1338 struct ext4_extent *ex;
1339 ext4_fsblk_t block;
1340 int depth; /* Note, NOT eh_depth; depth from top of tree */
1341 int ee_len;
1342
1343 if (unlikely(path == NULL)) {
1344 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1345 return -EIO;
1346 }
1347 depth = path->p_depth;
1348 *phys = 0;
1349
1350 if (depth == 0 && path->p_ext == NULL)
1351 return 0;
1352
1353 /* usually extent in the path covers blocks smaller
1354 * then *logical, but it can be that extent is the
1355 * first one in the file */
1356
1357 ex = path[depth].p_ext;
1358 ee_len = ext4_ext_get_actual_len(ex);
1359 if (*logical < le32_to_cpu(ex->ee_block)) {
1360 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1361 EXT4_ERROR_INODE(inode,
1362 "first_extent(path[%d].p_hdr) != ex",
1363 depth);
1364 return -EIO;
1365 }
1366 while (--depth >= 0) {
1367 ix = path[depth].p_idx;
1368 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1369 EXT4_ERROR_INODE(inode,
1370 "ix != EXT_FIRST_INDEX *logical %d!",
1371 *logical);
1372 return -EIO;
1373 }
1374 }
1375 goto found_extent;
1376 }
1377
1378 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1379 EXT4_ERROR_INODE(inode,
1380 "logical %d < ee_block %d + ee_len %d!",
1381 *logical, le32_to_cpu(ex->ee_block), ee_len);
1382 return -EIO;
1383 }
1384
1385 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1386 /* next allocated block in this leaf */
1387 ex++;
1388 goto found_extent;
1389 }
1390
1391 /* go up and search for index to the right */
1392 while (--depth >= 0) {
1393 ix = path[depth].p_idx;
1394 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1395 goto got_index;
1396 }
1397
1398 /* we've gone up to the root and found no index to the right */
1399 return 0;
1400
1401got_index:
1402 /* we've found index to the right, let's
1403 * follow it and find the closest allocated
1404 * block to the right */
1405 ix++;
1406 block = ext4_idx_pblock(ix);
1407 while (++depth < path->p_depth) {
1408 bh = sb_bread(inode->i_sb, block);
1409 if (bh == NULL)
1410 return -EIO;
1411 eh = ext_block_hdr(bh);
1412 /* subtract from p_depth to get proper eh_depth */
1413 if (ext4_ext_check_block(inode, eh,
1414 path->p_depth - depth, bh)) {
1415 put_bh(bh);
1416 return -EIO;
1417 }
1418 ix = EXT_FIRST_INDEX(eh);
1419 block = ext4_idx_pblock(ix);
1420 put_bh(bh);
1421 }
1422
1423 bh = sb_bread(inode->i_sb, block);
1424 if (bh == NULL)
1425 return -EIO;
1426 eh = ext_block_hdr(bh);
1427 if (ext4_ext_check_block(inode, eh, path->p_depth - depth, bh)) {
1428 put_bh(bh);
1429 return -EIO;
1430 }
1431 ex = EXT_FIRST_EXTENT(eh);
1432found_extent:
1433 *logical = le32_to_cpu(ex->ee_block);
1434 *phys = ext4_ext_pblock(ex);
1435 *ret_ex = ex;
1436 if (bh)
1437 put_bh(bh);
1438 return 0;
1439}
1440
1441/*
1442 * ext4_ext_next_allocated_block:
1443 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1444 * NOTE: it considers block number from index entry as
1445 * allocated block. Thus, index entries have to be consistent
1446 * with leaves.
1447 */
1448static ext4_lblk_t
1449ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1450{
1451 int depth;
1452
1453 BUG_ON(path == NULL);
1454 depth = path->p_depth;
1455
1456 if (depth == 0 && path->p_ext == NULL)
1457 return EXT_MAX_BLOCKS;
1458
1459 while (depth >= 0) {
1460 if (depth == path->p_depth) {
1461 /* leaf */
1462 if (path[depth].p_ext &&
1463 path[depth].p_ext !=
1464 EXT_LAST_EXTENT(path[depth].p_hdr))
1465 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1466 } else {
1467 /* index */
1468 if (path[depth].p_idx !=
1469 EXT_LAST_INDEX(path[depth].p_hdr))
1470 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1471 }
1472 depth--;
1473 }
1474
1475 return EXT_MAX_BLOCKS;
1476}
1477
1478/*
1479 * ext4_ext_next_leaf_block:
1480 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1481 */
1482static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1483{
1484 int depth;
1485
1486 BUG_ON(path == NULL);
1487 depth = path->p_depth;
1488
1489 /* zero-tree has no leaf blocks at all */
1490 if (depth == 0)
1491 return EXT_MAX_BLOCKS;
1492
1493 /* go to index block */
1494 depth--;
1495
1496 while (depth >= 0) {
1497 if (path[depth].p_idx !=
1498 EXT_LAST_INDEX(path[depth].p_hdr))
1499 return (ext4_lblk_t)
1500 le32_to_cpu(path[depth].p_idx[1].ei_block);
1501 depth--;
1502 }
1503
1504 return EXT_MAX_BLOCKS;
1505}
1506
1507/*
1508 * ext4_ext_correct_indexes:
1509 * if leaf gets modified and modified extent is first in the leaf,
1510 * then we have to correct all indexes above.
1511 * TODO: do we need to correct tree in all cases?
1512 */
1513static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1514 struct ext4_ext_path *path)
1515{
1516 struct ext4_extent_header *eh;
1517 int depth = ext_depth(inode);
1518 struct ext4_extent *ex;
1519 __le32 border;
1520 int k, err = 0;
1521
1522 eh = path[depth].p_hdr;
1523 ex = path[depth].p_ext;
1524
1525 if (unlikely(ex == NULL || eh == NULL)) {
1526 EXT4_ERROR_INODE(inode,
1527 "ex %p == NULL or eh %p == NULL", ex, eh);
1528 return -EIO;
1529 }
1530
1531 if (depth == 0) {
1532 /* there is no tree at all */
1533 return 0;
1534 }
1535
1536 if (ex != EXT_FIRST_EXTENT(eh)) {
1537 /* we correct tree if first leaf got modified only */
1538 return 0;
1539 }
1540
1541 /*
1542 * TODO: we need correction if border is smaller than current one
1543 */
1544 k = depth - 1;
1545 border = path[depth].p_ext->ee_block;
1546 err = ext4_ext_get_access(handle, inode, path + k);
1547 if (err)
1548 return err;
1549 path[k].p_idx->ei_block = border;
1550 err = ext4_ext_dirty(handle, inode, path + k);
1551 if (err)
1552 return err;
1553
1554 while (k--) {
1555 /* change all left-side indexes */
1556 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1557 break;
1558 err = ext4_ext_get_access(handle, inode, path + k);
1559 if (err)
1560 break;
1561 path[k].p_idx->ei_block = border;
1562 err = ext4_ext_dirty(handle, inode, path + k);
1563 if (err)
1564 break;
1565 }
1566
1567 return err;
1568}
1569
1570int
1571ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1572 struct ext4_extent *ex2)
1573{
1574 unsigned short ext1_ee_len, ext2_ee_len, max_len;
1575
1576 /*
1577 * Make sure that either both extents are uninitialized, or
1578 * both are _not_.
1579 */
1580 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
1581 return 0;
1582
1583 if (ext4_ext_is_uninitialized(ex1))
1584 max_len = EXT_UNINIT_MAX_LEN;
1585 else
1586 max_len = EXT_INIT_MAX_LEN;
1587
1588 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1589 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1590
1591 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1592 le32_to_cpu(ex2->ee_block))
1593 return 0;
1594
1595 /*
1596 * To allow future support for preallocated extents to be added
1597 * as an RO_COMPAT feature, refuse to merge to extents if
1598 * this can result in the top bit of ee_len being set.
1599 */
1600 if (ext1_ee_len + ext2_ee_len > max_len)
1601 return 0;
1602#ifdef AGGRESSIVE_TEST
1603 if (ext1_ee_len >= 4)
1604 return 0;
1605#endif
1606
1607 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1608 return 1;
1609 return 0;
1610}
1611
1612/*
1613 * This function tries to merge the "ex" extent to the next extent in the tree.
1614 * It always tries to merge towards right. If you want to merge towards
1615 * left, pass "ex - 1" as argument instead of "ex".
1616 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1617 * 1 if they got merged.
1618 */
1619static int ext4_ext_try_to_merge_right(struct inode *inode,
1620 struct ext4_ext_path *path,
1621 struct ext4_extent *ex)
1622{
1623 struct ext4_extent_header *eh;
1624 unsigned int depth, len;
1625 int merge_done = 0;
1626 int uninitialized = 0;
1627
1628 depth = ext_depth(inode);
1629 BUG_ON(path[depth].p_hdr == NULL);
1630 eh = path[depth].p_hdr;
1631
1632 while (ex < EXT_LAST_EXTENT(eh)) {
1633 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1634 break;
1635 /* merge with next extent! */
1636 if (ext4_ext_is_uninitialized(ex))
1637 uninitialized = 1;
1638 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1639 + ext4_ext_get_actual_len(ex + 1));
1640 if (uninitialized)
1641 ext4_ext_mark_uninitialized(ex);
1642
1643 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1644 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1645 * sizeof(struct ext4_extent);
1646 memmove(ex + 1, ex + 2, len);
1647 }
1648 le16_add_cpu(&eh->eh_entries, -1);
1649 merge_done = 1;
1650 WARN_ON(eh->eh_entries == 0);
1651 if (!eh->eh_entries)
1652 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1653 }
1654
1655 return merge_done;
1656}
1657
1658/*
1659 * This function tries to merge the @ex extent to neighbours in the tree.
1660 * return 1 if merge left else 0.
1661 */
1662static int ext4_ext_try_to_merge(struct inode *inode,
1663 struct ext4_ext_path *path,
1664 struct ext4_extent *ex) {
1665 struct ext4_extent_header *eh;
1666 unsigned int depth;
1667 int merge_done = 0;
1668 int ret = 0;
1669
1670 depth = ext_depth(inode);
1671 BUG_ON(path[depth].p_hdr == NULL);
1672 eh = path[depth].p_hdr;
1673
1674 if (ex > EXT_FIRST_EXTENT(eh))
1675 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1676
1677 if (!merge_done)
1678 ret = ext4_ext_try_to_merge_right(inode, path, ex);
1679
1680 return ret;
1681}
1682
1683/*
1684 * check if a portion of the "newext" extent overlaps with an
1685 * existing extent.
1686 *
1687 * If there is an overlap discovered, it updates the length of the newext
1688 * such that there will be no overlap, and then returns 1.
1689 * If there is no overlap found, it returns 0.
1690 */
1691static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1692 struct inode *inode,
1693 struct ext4_extent *newext,
1694 struct ext4_ext_path *path)
1695{
1696 ext4_lblk_t b1, b2;
1697 unsigned int depth, len1;
1698 unsigned int ret = 0;
1699
1700 b1 = le32_to_cpu(newext->ee_block);
1701 len1 = ext4_ext_get_actual_len(newext);
1702 depth = ext_depth(inode);
1703 if (!path[depth].p_ext)
1704 goto out;
1705 b2 = le32_to_cpu(path[depth].p_ext->ee_block);
1706 b2 &= ~(sbi->s_cluster_ratio - 1);
1707
1708 /*
1709 * get the next allocated block if the extent in the path
1710 * is before the requested block(s)
1711 */
1712 if (b2 < b1) {
1713 b2 = ext4_ext_next_allocated_block(path);
1714 if (b2 == EXT_MAX_BLOCKS)
1715 goto out;
1716 b2 &= ~(sbi->s_cluster_ratio - 1);
1717 }
1718
1719 /* check for wrap through zero on extent logical start block*/
1720 if (b1 + len1 < b1) {
1721 len1 = EXT_MAX_BLOCKS - b1;
1722 newext->ee_len = cpu_to_le16(len1);
1723 ret = 1;
1724 }
1725
1726 /* check for overlap */
1727 if (b1 + len1 > b2) {
1728 newext->ee_len = cpu_to_le16(b2 - b1);
1729 ret = 1;
1730 }
1731out:
1732 return ret;
1733}
1734
1735/*
1736 * ext4_ext_insert_extent:
1737 * tries to merge requsted extent into the existing extent or
1738 * inserts requested extent as new one into the tree,
1739 * creating new leaf in the no-space case.
1740 */
1741int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1742 struct ext4_ext_path *path,
1743 struct ext4_extent *newext, int flag)
1744{
1745 struct ext4_extent_header *eh;
1746 struct ext4_extent *ex, *fex;
1747 struct ext4_extent *nearex; /* nearest extent */
1748 struct ext4_ext_path *npath = NULL;
1749 int depth, len, err;
1750 ext4_lblk_t next;
1751 unsigned uninitialized = 0;
1752 int flags = 0;
1753
1754 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1755 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1756 return -EIO;
1757 }
1758 depth = ext_depth(inode);
1759 ex = path[depth].p_ext;
1760 if (unlikely(path[depth].p_hdr == NULL)) {
1761 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1762 return -EIO;
1763 }
1764
1765 /* try to insert block into found extent and return */
1766 if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO)
1767 && ext4_can_extents_be_merged(inode, ex, newext)) {
1768 ext_debug("append [%d]%d block to %u:[%d]%d (from %llu)\n",
1769 ext4_ext_is_uninitialized(newext),
1770 ext4_ext_get_actual_len(newext),
1771 le32_to_cpu(ex->ee_block),
1772 ext4_ext_is_uninitialized(ex),
1773 ext4_ext_get_actual_len(ex),
1774 ext4_ext_pblock(ex));
1775 err = ext4_ext_get_access(handle, inode, path + depth);
1776 if (err)
1777 return err;
1778
1779 /*
1780 * ext4_can_extents_be_merged should have checked that either
1781 * both extents are uninitialized, or both aren't. Thus we
1782 * need to check only one of them here.
1783 */
1784 if (ext4_ext_is_uninitialized(ex))
1785 uninitialized = 1;
1786 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1787 + ext4_ext_get_actual_len(newext));
1788 if (uninitialized)
1789 ext4_ext_mark_uninitialized(ex);
1790 eh = path[depth].p_hdr;
1791 nearex = ex;
1792 goto merge;
1793 }
1794
1795 depth = ext_depth(inode);
1796 eh = path[depth].p_hdr;
1797 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1798 goto has_space;
1799
1800 /* probably next leaf has space for us? */
1801 fex = EXT_LAST_EXTENT(eh);
1802 next = EXT_MAX_BLOCKS;
1803 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
1804 next = ext4_ext_next_leaf_block(path);
1805 if (next != EXT_MAX_BLOCKS) {
1806 ext_debug("next leaf block - %u\n", next);
1807 BUG_ON(npath != NULL);
1808 npath = ext4_ext_find_extent(inode, next, NULL);
1809 if (IS_ERR(npath))
1810 return PTR_ERR(npath);
1811 BUG_ON(npath->p_depth != path->p_depth);
1812 eh = npath[depth].p_hdr;
1813 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
1814 ext_debug("next leaf isn't full(%d)\n",
1815 le16_to_cpu(eh->eh_entries));
1816 path = npath;
1817 goto has_space;
1818 }
1819 ext_debug("next leaf has no free space(%d,%d)\n",
1820 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
1821 }
1822
1823 /*
1824 * There is no free space in the found leaf.
1825 * We're gonna add a new leaf in the tree.
1826 */
1827 if (flag & EXT4_GET_BLOCKS_PUNCH_OUT_EXT)
1828 flags = EXT4_MB_USE_ROOT_BLOCKS;
1829 err = ext4_ext_create_new_leaf(handle, inode, flags, path, newext);
1830 if (err)
1831 goto cleanup;
1832 depth = ext_depth(inode);
1833 eh = path[depth].p_hdr;
1834
1835has_space:
1836 nearex = path[depth].p_ext;
1837
1838 err = ext4_ext_get_access(handle, inode, path + depth);
1839 if (err)
1840 goto cleanup;
1841
1842 if (!nearex) {
1843 /* there is no extent in this leaf, create first one */
1844 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
1845 le32_to_cpu(newext->ee_block),
1846 ext4_ext_pblock(newext),
1847 ext4_ext_is_uninitialized(newext),
1848 ext4_ext_get_actual_len(newext));
1849 nearex = EXT_FIRST_EXTENT(eh);
1850 } else {
1851 if (le32_to_cpu(newext->ee_block)
1852 > le32_to_cpu(nearex->ee_block)) {
1853 /* Insert after */
1854 ext_debug("insert %u:%llu:[%d]%d before: "
1855 "nearest %p\n",
1856 le32_to_cpu(newext->ee_block),
1857 ext4_ext_pblock(newext),
1858 ext4_ext_is_uninitialized(newext),
1859 ext4_ext_get_actual_len(newext),
1860 nearex);
1861 nearex++;
1862 } else {
1863 /* Insert before */
1864 BUG_ON(newext->ee_block == nearex->ee_block);
1865 ext_debug("insert %u:%llu:[%d]%d after: "
1866 "nearest %p\n",
1867 le32_to_cpu(newext->ee_block),
1868 ext4_ext_pblock(newext),
1869 ext4_ext_is_uninitialized(newext),
1870 ext4_ext_get_actual_len(newext),
1871 nearex);
1872 }
1873 len = EXT_LAST_EXTENT(eh) - nearex + 1;
1874 if (len > 0) {
1875 ext_debug("insert %u:%llu:[%d]%d: "
1876 "move %d extents from 0x%p to 0x%p\n",
1877 le32_to_cpu(newext->ee_block),
1878 ext4_ext_pblock(newext),
1879 ext4_ext_is_uninitialized(newext),
1880 ext4_ext_get_actual_len(newext),
1881 len, nearex, nearex + 1);
1882 memmove(nearex + 1, nearex,
1883 len * sizeof(struct ext4_extent));
1884 }
1885 }
1886
1887 le16_add_cpu(&eh->eh_entries, 1);
1888 path[depth].p_ext = nearex;
1889 nearex->ee_block = newext->ee_block;
1890 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
1891 nearex->ee_len = newext->ee_len;
1892
1893merge:
1894 /* try to merge extents to the right */
1895 if (!(flag & EXT4_GET_BLOCKS_PRE_IO))
1896 ext4_ext_try_to_merge(inode, path, nearex);
1897
1898 /* try to merge extents to the left */
1899
1900 /* time to correct all indexes above */
1901 err = ext4_ext_correct_indexes(handle, inode, path);
1902 if (err)
1903 goto cleanup;
1904
1905 err = ext4_ext_dirty(handle, inode, path + depth);
1906
1907cleanup:
1908 if (npath) {
1909 ext4_ext_drop_refs(npath);
1910 kfree(npath);
1911 }
1912 ext4_ext_invalidate_cache(inode);
1913 return err;
1914}
1915
1916static int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block,
1917 ext4_lblk_t num, ext_prepare_callback func,
1918 void *cbdata)
1919{
1920 struct ext4_ext_path *path = NULL;
1921 struct ext4_ext_cache cbex;
1922 struct ext4_extent *ex;
1923 ext4_lblk_t next, start = 0, end = 0;
1924 ext4_lblk_t last = block + num;
1925 int depth, exists, err = 0;
1926
1927 BUG_ON(func == NULL);
1928 BUG_ON(inode == NULL);
1929
1930 while (block < last && block != EXT_MAX_BLOCKS) {
1931 num = last - block;
1932 /* find extent for this block */
1933 down_read(&EXT4_I(inode)->i_data_sem);
1934 path = ext4_ext_find_extent(inode, block, path);
1935 up_read(&EXT4_I(inode)->i_data_sem);
1936 if (IS_ERR(path)) {
1937 err = PTR_ERR(path);
1938 path = NULL;
1939 break;
1940 }
1941
1942 depth = ext_depth(inode);
1943 if (unlikely(path[depth].p_hdr == NULL)) {
1944 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1945 err = -EIO;
1946 break;
1947 }
1948 ex = path[depth].p_ext;
1949 next = ext4_ext_next_allocated_block(path);
1950
1951 exists = 0;
1952 if (!ex) {
1953 /* there is no extent yet, so try to allocate
1954 * all requested space */
1955 start = block;
1956 end = block + num;
1957 } else if (le32_to_cpu(ex->ee_block) > block) {
1958 /* need to allocate space before found extent */
1959 start = block;
1960 end = le32_to_cpu(ex->ee_block);
1961 if (block + num < end)
1962 end = block + num;
1963 } else if (block >= le32_to_cpu(ex->ee_block)
1964 + ext4_ext_get_actual_len(ex)) {
1965 /* need to allocate space after found extent */
1966 start = block;
1967 end = block + num;
1968 if (end >= next)
1969 end = next;
1970 } else if (block >= le32_to_cpu(ex->ee_block)) {
1971 /*
1972 * some part of requested space is covered
1973 * by found extent
1974 */
1975 start = block;
1976 end = le32_to_cpu(ex->ee_block)
1977 + ext4_ext_get_actual_len(ex);
1978 if (block + num < end)
1979 end = block + num;
1980 exists = 1;
1981 } else {
1982 BUG();
1983 }
1984 BUG_ON(end <= start);
1985
1986 if (!exists) {
1987 cbex.ec_block = start;
1988 cbex.ec_len = end - start;
1989 cbex.ec_start = 0;
1990 } else {
1991 cbex.ec_block = le32_to_cpu(ex->ee_block);
1992 cbex.ec_len = ext4_ext_get_actual_len(ex);
1993 cbex.ec_start = ext4_ext_pblock(ex);
1994 }
1995
1996 if (unlikely(cbex.ec_len == 0)) {
1997 EXT4_ERROR_INODE(inode, "cbex.ec_len == 0");
1998 err = -EIO;
1999 break;
2000 }
2001 err = func(inode, next, &cbex, ex, cbdata);
2002 ext4_ext_drop_refs(path);
2003
2004 if (err < 0)
2005 break;
2006
2007 if (err == EXT_REPEAT)
2008 continue;
2009 else if (err == EXT_BREAK) {
2010 err = 0;
2011 break;
2012 }
2013
2014 if (ext_depth(inode) != depth) {
2015 /* depth was changed. we have to realloc path */
2016 kfree(path);
2017 path = NULL;
2018 }
2019
2020 block = cbex.ec_block + cbex.ec_len;
2021 }
2022
2023 if (path) {
2024 ext4_ext_drop_refs(path);
2025 kfree(path);
2026 }
2027
2028 return err;
2029}
2030
2031static void
2032ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
2033 __u32 len, ext4_fsblk_t start)
2034{
2035 struct ext4_ext_cache *cex;
2036 BUG_ON(len == 0);
2037 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
2038 trace_ext4_ext_put_in_cache(inode, block, len, start);
2039 cex = &EXT4_I(inode)->i_cached_extent;
2040 cex->ec_block = block;
2041 cex->ec_len = len;
2042 cex->ec_start = start;
2043 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
2044}
2045
2046/*
2047 * ext4_ext_put_gap_in_cache:
2048 * calculate boundaries of the gap that the requested block fits into
2049 * and cache this gap
2050 */
2051static void
2052ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
2053 ext4_lblk_t block)
2054{
2055 int depth = ext_depth(inode);
2056 unsigned long len;
2057 ext4_lblk_t lblock;
2058 struct ext4_extent *ex;
2059
2060 ex = path[depth].p_ext;
2061 if (ex == NULL) {
2062 /* there is no extent yet, so gap is [0;-] */
2063 lblock = 0;
2064 len = EXT_MAX_BLOCKS;
2065 ext_debug("cache gap(whole file):");
2066 } else if (block < le32_to_cpu(ex->ee_block)) {
2067 lblock = block;
2068 len = le32_to_cpu(ex->ee_block) - block;
2069 ext_debug("cache gap(before): %u [%u:%u]",
2070 block,
2071 le32_to_cpu(ex->ee_block),
2072 ext4_ext_get_actual_len(ex));
2073 } else if (block >= le32_to_cpu(ex->ee_block)
2074 + ext4_ext_get_actual_len(ex)) {
2075 ext4_lblk_t next;
2076 lblock = le32_to_cpu(ex->ee_block)
2077 + ext4_ext_get_actual_len(ex);
2078
2079 next = ext4_ext_next_allocated_block(path);
2080 ext_debug("cache gap(after): [%u:%u] %u",
2081 le32_to_cpu(ex->ee_block),
2082 ext4_ext_get_actual_len(ex),
2083 block);
2084 BUG_ON(next == lblock);
2085 len = next - lblock;
2086 } else {
2087 lblock = len = 0;
2088 BUG();
2089 }
2090
2091 ext_debug(" -> %u:%lu\n", lblock, len);
2092 ext4_ext_put_in_cache(inode, lblock, len, 0);
2093}
2094
2095/*
2096 * ext4_ext_check_cache()
2097 * Checks to see if the given block is in the cache.
2098 * If it is, the cached extent is stored in the given
2099 * cache extent pointer. If the cached extent is a hole,
2100 * this routine should be used instead of
2101 * ext4_ext_in_cache if the calling function needs to
2102 * know the size of the hole.
2103 *
2104 * @inode: The files inode
2105 * @block: The block to look for in the cache
2106 * @ex: Pointer where the cached extent will be stored
2107 * if it contains block
2108 *
2109 * Return 0 if cache is invalid; 1 if the cache is valid
2110 */
2111static int ext4_ext_check_cache(struct inode *inode, ext4_lblk_t block,
2112 struct ext4_ext_cache *ex){
2113 struct ext4_ext_cache *cex;
2114 struct ext4_sb_info *sbi;
2115 int ret = 0;
2116
2117 /*
2118 * We borrow i_block_reservation_lock to protect i_cached_extent
2119 */
2120 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
2121 cex = &EXT4_I(inode)->i_cached_extent;
2122 sbi = EXT4_SB(inode->i_sb);
2123
2124 /* has cache valid data? */
2125 if (cex->ec_len == 0)
2126 goto errout;
2127
2128 if (in_range(block, cex->ec_block, cex->ec_len)) {
2129 memcpy(ex, cex, sizeof(struct ext4_ext_cache));
2130 ext_debug("%u cached by %u:%u:%llu\n",
2131 block,
2132 cex->ec_block, cex->ec_len, cex->ec_start);
2133 ret = 1;
2134 }
2135errout:
2136 trace_ext4_ext_in_cache(inode, block, ret);
2137 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
2138 return ret;
2139}
2140
2141/*
2142 * ext4_ext_in_cache()
2143 * Checks to see if the given block is in the cache.
2144 * If it is, the cached extent is stored in the given
2145 * extent pointer.
2146 *
2147 * @inode: The files inode
2148 * @block: The block to look for in the cache
2149 * @ex: Pointer where the cached extent will be stored
2150 * if it contains block
2151 *
2152 * Return 0 if cache is invalid; 1 if the cache is valid
2153 */
2154static int
2155ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
2156 struct ext4_extent *ex)
2157{
2158 struct ext4_ext_cache cex;
2159 int ret = 0;
2160
2161 if (ext4_ext_check_cache(inode, block, &cex)) {
2162 ex->ee_block = cpu_to_le32(cex.ec_block);
2163 ext4_ext_store_pblock(ex, cex.ec_start);
2164 ex->ee_len = cpu_to_le16(cex.ec_len);
2165 ret = 1;
2166 }
2167
2168 return ret;
2169}
2170
2171
2172/*
2173 * ext4_ext_rm_idx:
2174 * removes index from the index block.
2175 */
2176static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2177 struct ext4_ext_path *path)
2178{
2179 int err;
2180 ext4_fsblk_t leaf;
2181
2182 /* free index block */
2183 path--;
2184 leaf = ext4_idx_pblock(path->p_idx);
2185 if (unlikely(path->p_hdr->eh_entries == 0)) {
2186 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2187 return -EIO;
2188 }
2189 err = ext4_ext_get_access(handle, inode, path);
2190 if (err)
2191 return err;
2192
2193 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2194 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2195 len *= sizeof(struct ext4_extent_idx);
2196 memmove(path->p_idx, path->p_idx + 1, len);
2197 }
2198
2199 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2200 err = ext4_ext_dirty(handle, inode, path);
2201 if (err)
2202 return err;
2203 ext_debug("index is empty, remove it, free block %llu\n", leaf);
2204 trace_ext4_ext_rm_idx(inode, leaf);
2205
2206 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2207 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2208 return err;
2209}
2210
2211/*
2212 * ext4_ext_calc_credits_for_single_extent:
2213 * This routine returns max. credits that needed to insert an extent
2214 * to the extent tree.
2215 * When pass the actual path, the caller should calculate credits
2216 * under i_data_sem.
2217 */
2218int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2219 struct ext4_ext_path *path)
2220{
2221 if (path) {
2222 int depth = ext_depth(inode);
2223 int ret = 0;
2224
2225 /* probably there is space in leaf? */
2226 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2227 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2228
2229 /*
2230 * There are some space in the leaf tree, no
2231 * need to account for leaf block credit
2232 *
2233 * bitmaps and block group descriptor blocks
2234 * and other metadata blocks still need to be
2235 * accounted.
2236 */
2237 /* 1 bitmap, 1 block group descriptor */
2238 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2239 return ret;
2240 }
2241 }
2242
2243 return ext4_chunk_trans_blocks(inode, nrblocks);
2244}
2245
2246/*
2247 * How many index/leaf blocks need to change/allocate to modify nrblocks?
2248 *
2249 * if nrblocks are fit in a single extent (chunk flag is 1), then
2250 * in the worse case, each tree level index/leaf need to be changed
2251 * if the tree split due to insert a new extent, then the old tree
2252 * index/leaf need to be updated too
2253 *
2254 * If the nrblocks are discontiguous, they could cause
2255 * the whole tree split more than once, but this is really rare.
2256 */
2257int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
2258{
2259 int index;
2260 int depth = ext_depth(inode);
2261
2262 if (chunk)
2263 index = depth * 2;
2264 else
2265 index = depth * 3;
2266
2267 return index;
2268}
2269
2270static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2271 struct ext4_extent *ex,
2272 ext4_fsblk_t *partial_cluster,
2273 ext4_lblk_t from, ext4_lblk_t to)
2274{
2275 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2276 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2277 ext4_fsblk_t pblk;
2278 int flags = EXT4_FREE_BLOCKS_FORGET;
2279
2280 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2281 flags |= EXT4_FREE_BLOCKS_METADATA;
2282 /*
2283 * For bigalloc file systems, we never free a partial cluster
2284 * at the beginning of the extent. Instead, we make a note
2285 * that we tried freeing the cluster, and check to see if we
2286 * need to free it on a subsequent call to ext4_remove_blocks,
2287 * or at the end of the ext4_truncate() operation.
2288 */
2289 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2290
2291 trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2292 /*
2293 * If we have a partial cluster, and it's different from the
2294 * cluster of the last block, we need to explicitly free the
2295 * partial cluster here.
2296 */
2297 pblk = ext4_ext_pblock(ex) + ee_len - 1;
2298 if (*partial_cluster && (EXT4_B2C(sbi, pblk) != *partial_cluster)) {
2299 ext4_free_blocks(handle, inode, NULL,
2300 EXT4_C2B(sbi, *partial_cluster),
2301 sbi->s_cluster_ratio, flags);
2302 *partial_cluster = 0;
2303 }
2304
2305#ifdef EXTENTS_STATS
2306 {
2307 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2308 spin_lock(&sbi->s_ext_stats_lock);
2309 sbi->s_ext_blocks += ee_len;
2310 sbi->s_ext_extents++;
2311 if (ee_len < sbi->s_ext_min)
2312 sbi->s_ext_min = ee_len;
2313 if (ee_len > sbi->s_ext_max)
2314 sbi->s_ext_max = ee_len;
2315 if (ext_depth(inode) > sbi->s_depth_max)
2316 sbi->s_depth_max = ext_depth(inode);
2317 spin_unlock(&sbi->s_ext_stats_lock);
2318 }
2319#endif
2320 if (from >= le32_to_cpu(ex->ee_block)
2321 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2322 /* tail removal */
2323 ext4_lblk_t num;
2324
2325 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2326 pblk = ext4_ext_pblock(ex) + ee_len - num;
2327 ext_debug("free last %u blocks starting %llu\n", num, pblk);
2328 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2329 /*
2330 * If the block range to be freed didn't start at the
2331 * beginning of a cluster, and we removed the entire
2332 * extent, save the partial cluster here, since we
2333 * might need to delete if we determine that the
2334 * truncate operation has removed all of the blocks in
2335 * the cluster.
2336 */
2337 if (pblk & (sbi->s_cluster_ratio - 1) &&
2338 (ee_len == num))
2339 *partial_cluster = EXT4_B2C(sbi, pblk);
2340 else
2341 *partial_cluster = 0;
2342 } else if (from == le32_to_cpu(ex->ee_block)
2343 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
2344 /* head removal */
2345 ext4_lblk_t num;
2346 ext4_fsblk_t start;
2347
2348 num = to - from;
2349 start = ext4_ext_pblock(ex);
2350
2351 ext_debug("free first %u blocks starting %llu\n", num, start);
2352 ext4_free_blocks(handle, inode, NULL, start, num, flags);
2353
2354 } else {
2355 printk(KERN_INFO "strange request: removal(2) "
2356 "%u-%u from %u:%u\n",
2357 from, to, le32_to_cpu(ex->ee_block), ee_len);
2358 }
2359 return 0;
2360}
2361
2362
2363/*
2364 * ext4_ext_rm_leaf() Removes the extents associated with the
2365 * blocks appearing between "start" and "end", and splits the extents
2366 * if "start" and "end" appear in the same extent
2367 *
2368 * @handle: The journal handle
2369 * @inode: The files inode
2370 * @path: The path to the leaf
2371 * @start: The first block to remove
2372 * @end: The last block to remove
2373 */
2374static int
2375ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2376 struct ext4_ext_path *path, ext4_fsblk_t *partial_cluster,
2377 ext4_lblk_t start, ext4_lblk_t end)
2378{
2379 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2380 int err = 0, correct_index = 0;
2381 int depth = ext_depth(inode), credits;
2382 struct ext4_extent_header *eh;
2383 ext4_lblk_t a, b;
2384 unsigned num;
2385 ext4_lblk_t ex_ee_block;
2386 unsigned short ex_ee_len;
2387 unsigned uninitialized = 0;
2388 struct ext4_extent *ex;
2389
2390 /* the header must be checked already in ext4_ext_remove_space() */
2391 ext_debug("truncate since %u in leaf to %u\n", start, end);
2392 if (!path[depth].p_hdr)
2393 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2394 eh = path[depth].p_hdr;
2395 if (unlikely(path[depth].p_hdr == NULL)) {
2396 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2397 return -EIO;
2398 }
2399 /* find where to start removing */
2400 ex = EXT_LAST_EXTENT(eh);
2401
2402 ex_ee_block = le32_to_cpu(ex->ee_block);
2403 ex_ee_len = ext4_ext_get_actual_len(ex);
2404
2405 trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2406
2407 while (ex >= EXT_FIRST_EXTENT(eh) &&
2408 ex_ee_block + ex_ee_len > start) {
2409
2410 if (ext4_ext_is_uninitialized(ex))
2411 uninitialized = 1;
2412 else
2413 uninitialized = 0;
2414
2415 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2416 uninitialized, ex_ee_len);
2417 path[depth].p_ext = ex;
2418
2419 a = ex_ee_block > start ? ex_ee_block : start;
2420 b = ex_ee_block+ex_ee_len - 1 < end ?
2421 ex_ee_block+ex_ee_len - 1 : end;
2422
2423 ext_debug(" border %u:%u\n", a, b);
2424
2425 /* If this extent is beyond the end of the hole, skip it */
2426 if (end < ex_ee_block) {
2427 ex--;
2428 ex_ee_block = le32_to_cpu(ex->ee_block);
2429 ex_ee_len = ext4_ext_get_actual_len(ex);
2430 continue;
2431 } else if (b != ex_ee_block + ex_ee_len - 1) {
2432 EXT4_ERROR_INODE(inode,
2433 "can not handle truncate %u:%u "
2434 "on extent %u:%u",
2435 start, end, ex_ee_block,
2436 ex_ee_block + ex_ee_len - 1);
2437 err = -EIO;
2438 goto out;
2439 } else if (a != ex_ee_block) {
2440 /* remove tail of the extent */
2441 num = a - ex_ee_block;
2442 } else {
2443 /* remove whole extent: excellent! */
2444 num = 0;
2445 }
2446 /*
2447 * 3 for leaf, sb, and inode plus 2 (bmap and group
2448 * descriptor) for each block group; assume two block
2449 * groups plus ex_ee_len/blocks_per_block_group for
2450 * the worst case
2451 */
2452 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2453 if (ex == EXT_FIRST_EXTENT(eh)) {
2454 correct_index = 1;
2455 credits += (ext_depth(inode)) + 1;
2456 }
2457 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2458
2459 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2460 if (err)
2461 goto out;
2462
2463 err = ext4_ext_get_access(handle, inode, path + depth);
2464 if (err)
2465 goto out;
2466
2467 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2468 a, b);
2469 if (err)
2470 goto out;
2471
2472 if (num == 0)
2473 /* this extent is removed; mark slot entirely unused */
2474 ext4_ext_store_pblock(ex, 0);
2475
2476 ex->ee_len = cpu_to_le16(num);
2477 /*
2478 * Do not mark uninitialized if all the blocks in the
2479 * extent have been removed.
2480 */
2481 if (uninitialized && num)
2482 ext4_ext_mark_uninitialized(ex);
2483 /*
2484 * If the extent was completely released,
2485 * we need to remove it from the leaf
2486 */
2487 if (num == 0) {
2488 if (end != EXT_MAX_BLOCKS - 1) {
2489 /*
2490 * For hole punching, we need to scoot all the
2491 * extents up when an extent is removed so that
2492 * we dont have blank extents in the middle
2493 */
2494 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2495 sizeof(struct ext4_extent));
2496
2497 /* Now get rid of the one at the end */
2498 memset(EXT_LAST_EXTENT(eh), 0,
2499 sizeof(struct ext4_extent));
2500 }
2501 le16_add_cpu(&eh->eh_entries, -1);
2502 } else
2503 *partial_cluster = 0;
2504
2505 err = ext4_ext_dirty(handle, inode, path + depth);
2506 if (err)
2507 goto out;
2508
2509 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2510 ext4_ext_pblock(ex));
2511 ex--;
2512 ex_ee_block = le32_to_cpu(ex->ee_block);
2513 ex_ee_len = ext4_ext_get_actual_len(ex);
2514 }
2515
2516 if (correct_index && eh->eh_entries)
2517 err = ext4_ext_correct_indexes(handle, inode, path);
2518
2519 /*
2520 * If there is still a entry in the leaf node, check to see if
2521 * it references the partial cluster. This is the only place
2522 * where it could; if it doesn't, we can free the cluster.
2523 */
2524 if (*partial_cluster && ex >= EXT_FIRST_EXTENT(eh) &&
2525 (EXT4_B2C(sbi, ext4_ext_pblock(ex) + ex_ee_len - 1) !=
2526 *partial_cluster)) {
2527 int flags = EXT4_FREE_BLOCKS_FORGET;
2528
2529 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2530 flags |= EXT4_FREE_BLOCKS_METADATA;
2531
2532 ext4_free_blocks(handle, inode, NULL,
2533 EXT4_C2B(sbi, *partial_cluster),
2534 sbi->s_cluster_ratio, flags);
2535 *partial_cluster = 0;
2536 }
2537
2538 /* if this leaf is free, then we should
2539 * remove it from index block above */
2540 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2541 err = ext4_ext_rm_idx(handle, inode, path + depth);
2542
2543out:
2544 return err;
2545}
2546
2547/*
2548 * ext4_ext_more_to_rm:
2549 * returns 1 if current index has to be freed (even partial)
2550 */
2551static int
2552ext4_ext_more_to_rm(struct ext4_ext_path *path)
2553{
2554 BUG_ON(path->p_idx == NULL);
2555
2556 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2557 return 0;
2558
2559 /*
2560 * if truncate on deeper level happened, it wasn't partial,
2561 * so we have to consider current index for truncation
2562 */
2563 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2564 return 0;
2565 return 1;
2566}
2567
2568static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2569 ext4_lblk_t end)
2570{
2571 struct super_block *sb = inode->i_sb;
2572 int depth = ext_depth(inode);
2573 struct ext4_ext_path *path = NULL;
2574 ext4_fsblk_t partial_cluster = 0;
2575 handle_t *handle;
2576 int i = 0, err;
2577
2578 ext_debug("truncate since %u to %u\n", start, end);
2579
2580 /* probably first extent we're gonna free will be last in block */
2581 handle = ext4_journal_start(inode, depth + 1);
2582 if (IS_ERR(handle))
2583 return PTR_ERR(handle);
2584
2585again:
2586 ext4_ext_invalidate_cache(inode);
2587
2588 trace_ext4_ext_remove_space(inode, start, depth);
2589
2590 /*
2591 * Check if we are removing extents inside the extent tree. If that
2592 * is the case, we are going to punch a hole inside the extent tree
2593 * so we have to check whether we need to split the extent covering
2594 * the last block to remove so we can easily remove the part of it
2595 * in ext4_ext_rm_leaf().
2596 */
2597 if (end < EXT_MAX_BLOCKS - 1) {
2598 struct ext4_extent *ex;
2599 ext4_lblk_t ee_block;
2600
2601 /* find extent for this block */
2602 path = ext4_ext_find_extent(inode, end, NULL);
2603 if (IS_ERR(path)) {
2604 ext4_journal_stop(handle);
2605 return PTR_ERR(path);
2606 }
2607 depth = ext_depth(inode);
2608 ex = path[depth].p_ext;
2609 if (!ex) {
2610 ext4_ext_drop_refs(path);
2611 kfree(path);
2612 path = NULL;
2613 goto cont;
2614 }
2615
2616 ee_block = le32_to_cpu(ex->ee_block);
2617
2618 /*
2619 * See if the last block is inside the extent, if so split
2620 * the extent at 'end' block so we can easily remove the
2621 * tail of the first part of the split extent in
2622 * ext4_ext_rm_leaf().
2623 */
2624 if (end >= ee_block &&
2625 end < ee_block + ext4_ext_get_actual_len(ex) - 1) {
2626 int split_flag = 0;
2627
2628 if (ext4_ext_is_uninitialized(ex))
2629 split_flag = EXT4_EXT_MARK_UNINIT1 |
2630 EXT4_EXT_MARK_UNINIT2;
2631
2632 /*
2633 * Split the extent in two so that 'end' is the last
2634 * block in the first new extent
2635 */
2636 err = ext4_split_extent_at(handle, inode, path,
2637 end + 1, split_flag,
2638 EXT4_GET_BLOCKS_PRE_IO |
2639 EXT4_GET_BLOCKS_PUNCH_OUT_EXT);
2640
2641 if (err < 0)
2642 goto out;
2643 }
2644 }
2645cont:
2646
2647 /*
2648 * We start scanning from right side, freeing all the blocks
2649 * after i_size and walking into the tree depth-wise.
2650 */
2651 depth = ext_depth(inode);
2652 if (path) {
2653 int k = i = depth;
2654 while (--k > 0)
2655 path[k].p_block =
2656 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2657 } else {
2658 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2659 GFP_NOFS);
2660 if (path == NULL) {
2661 ext4_journal_stop(handle);
2662 return -ENOMEM;
2663 }
2664 path[0].p_depth = depth;
2665 path[0].p_hdr = ext_inode_hdr(inode);
2666 i = 0;
2667
2668 if (ext4_ext_check(inode, path[0].p_hdr, depth)) {
2669 err = -EIO;
2670 goto out;
2671 }
2672 }
2673 err = 0;
2674
2675 while (i >= 0 && err == 0) {
2676 if (i == depth) {
2677 /* this is leaf block */
2678 err = ext4_ext_rm_leaf(handle, inode, path,
2679 &partial_cluster, start,
2680 end);
2681 /* root level has p_bh == NULL, brelse() eats this */
2682 brelse(path[i].p_bh);
2683 path[i].p_bh = NULL;
2684 i--;
2685 continue;
2686 }
2687
2688 /* this is index block */
2689 if (!path[i].p_hdr) {
2690 ext_debug("initialize header\n");
2691 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2692 }
2693
2694 if (!path[i].p_idx) {
2695 /* this level hasn't been touched yet */
2696 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2697 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2698 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2699 path[i].p_hdr,
2700 le16_to_cpu(path[i].p_hdr->eh_entries));
2701 } else {
2702 /* we were already here, see at next index */
2703 path[i].p_idx--;
2704 }
2705
2706 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2707 i, EXT_FIRST_INDEX(path[i].p_hdr),
2708 path[i].p_idx);
2709 if (ext4_ext_more_to_rm(path + i)) {
2710 struct buffer_head *bh;
2711 /* go to the next level */
2712 ext_debug("move to level %d (block %llu)\n",
2713 i + 1, ext4_idx_pblock(path[i].p_idx));
2714 memset(path + i + 1, 0, sizeof(*path));
2715 bh = sb_bread(sb, ext4_idx_pblock(path[i].p_idx));
2716 if (!bh) {
2717 /* should we reset i_size? */
2718 err = -EIO;
2719 break;
2720 }
2721 if (WARN_ON(i + 1 > depth)) {
2722 err = -EIO;
2723 break;
2724 }
2725 if (ext4_ext_check_block(inode, ext_block_hdr(bh),
2726 depth - i - 1, bh)) {
2727 err = -EIO;
2728 break;
2729 }
2730 path[i + 1].p_bh = bh;
2731
2732 /* save actual number of indexes since this
2733 * number is changed at the next iteration */
2734 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2735 i++;
2736 } else {
2737 /* we finished processing this index, go up */
2738 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2739 /* index is empty, remove it;
2740 * handle must be already prepared by the
2741 * truncatei_leaf() */
2742 err = ext4_ext_rm_idx(handle, inode, path + i);
2743 }
2744 /* root level has p_bh == NULL, brelse() eats this */
2745 brelse(path[i].p_bh);
2746 path[i].p_bh = NULL;
2747 i--;
2748 ext_debug("return to level %d\n", i);
2749 }
2750 }
2751
2752 trace_ext4_ext_remove_space_done(inode, start, depth, partial_cluster,
2753 path->p_hdr->eh_entries);
2754
2755 /* If we still have something in the partial cluster and we have removed
2756 * even the first extent, then we should free the blocks in the partial
2757 * cluster as well. */
2758 if (partial_cluster && path->p_hdr->eh_entries == 0) {
2759 int flags = EXT4_FREE_BLOCKS_FORGET;
2760
2761 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2762 flags |= EXT4_FREE_BLOCKS_METADATA;
2763
2764 ext4_free_blocks(handle, inode, NULL,
2765 EXT4_C2B(EXT4_SB(sb), partial_cluster),
2766 EXT4_SB(sb)->s_cluster_ratio, flags);
2767 partial_cluster = 0;
2768 }
2769
2770 /* TODO: flexible tree reduction should be here */
2771 if (path->p_hdr->eh_entries == 0) {
2772 /*
2773 * truncate to zero freed all the tree,
2774 * so we need to correct eh_depth
2775 */
2776 err = ext4_ext_get_access(handle, inode, path);
2777 if (err == 0) {
2778 ext_inode_hdr(inode)->eh_depth = 0;
2779 ext_inode_hdr(inode)->eh_max =
2780 cpu_to_le16(ext4_ext_space_root(inode, 0));
2781 err = ext4_ext_dirty(handle, inode, path);
2782 }
2783 }
2784out:
2785 ext4_ext_drop_refs(path);
2786 kfree(path);
2787 if (err == -EAGAIN) {
2788 path = NULL;
2789 goto again;
2790 }
2791 ext4_journal_stop(handle);
2792
2793 return err;
2794}
2795
2796/*
2797 * called at mount time
2798 */
2799void ext4_ext_init(struct super_block *sb)
2800{
2801 /*
2802 * possible initialization would be here
2803 */
2804
2805 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2806#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
2807 printk(KERN_INFO "EXT4-fs: file extents enabled"
2808#ifdef AGGRESSIVE_TEST
2809 ", aggressive tests"
2810#endif
2811#ifdef CHECK_BINSEARCH
2812 ", check binsearch"
2813#endif
2814#ifdef EXTENTS_STATS
2815 ", stats"
2816#endif
2817 "\n");
2818#endif
2819#ifdef EXTENTS_STATS
2820 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
2821 EXT4_SB(sb)->s_ext_min = 1 << 30;
2822 EXT4_SB(sb)->s_ext_max = 0;
2823#endif
2824 }
2825}
2826
2827/*
2828 * called at umount time
2829 */
2830void ext4_ext_release(struct super_block *sb)
2831{
2832 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
2833 return;
2834
2835#ifdef EXTENTS_STATS
2836 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
2837 struct ext4_sb_info *sbi = EXT4_SB(sb);
2838 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
2839 sbi->s_ext_blocks, sbi->s_ext_extents,
2840 sbi->s_ext_blocks / sbi->s_ext_extents);
2841 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
2842 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
2843 }
2844#endif
2845}
2846
2847/* FIXME!! we need to try to merge to left or right after zero-out */
2848static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
2849{
2850 ext4_fsblk_t ee_pblock;
2851 unsigned int ee_len;
2852 int ret;
2853
2854 ee_len = ext4_ext_get_actual_len(ex);
2855 ee_pblock = ext4_ext_pblock(ex);
2856
2857 ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
2858 if (ret > 0)
2859 ret = 0;
2860
2861 return ret;
2862}
2863
2864/*
2865 * ext4_split_extent_at() splits an extent at given block.
2866 *
2867 * @handle: the journal handle
2868 * @inode: the file inode
2869 * @path: the path to the extent
2870 * @split: the logical block where the extent is splitted.
2871 * @split_flags: indicates if the extent could be zeroout if split fails, and
2872 * the states(init or uninit) of new extents.
2873 * @flags: flags used to insert new extent to extent tree.
2874 *
2875 *
2876 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
2877 * of which are deterimined by split_flag.
2878 *
2879 * There are two cases:
2880 * a> the extent are splitted into two extent.
2881 * b> split is not needed, and just mark the extent.
2882 *
2883 * return 0 on success.
2884 */
2885static int ext4_split_extent_at(handle_t *handle,
2886 struct inode *inode,
2887 struct ext4_ext_path *path,
2888 ext4_lblk_t split,
2889 int split_flag,
2890 int flags)
2891{
2892 ext4_fsblk_t newblock;
2893 ext4_lblk_t ee_block;
2894 struct ext4_extent *ex, newex, orig_ex;
2895 struct ext4_extent *ex2 = NULL;
2896 unsigned int ee_len, depth;
2897 int err = 0;
2898
2899 ext_debug("ext4_split_extents_at: inode %lu, logical"
2900 "block %llu\n", inode->i_ino, (unsigned long long)split);
2901
2902 ext4_ext_show_leaf(inode, path);
2903
2904 depth = ext_depth(inode);
2905 ex = path[depth].p_ext;
2906 ee_block = le32_to_cpu(ex->ee_block);
2907 ee_len = ext4_ext_get_actual_len(ex);
2908 newblock = split - ee_block + ext4_ext_pblock(ex);
2909
2910 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
2911
2912 err = ext4_ext_get_access(handle, inode, path + depth);
2913 if (err)
2914 goto out;
2915
2916 if (split == ee_block) {
2917 /*
2918 * case b: block @split is the block that the extent begins with
2919 * then we just change the state of the extent, and splitting
2920 * is not needed.
2921 */
2922 if (split_flag & EXT4_EXT_MARK_UNINIT2)
2923 ext4_ext_mark_uninitialized(ex);
2924 else
2925 ext4_ext_mark_initialized(ex);
2926
2927 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
2928 ext4_ext_try_to_merge(inode, path, ex);
2929
2930 err = ext4_ext_dirty(handle, inode, path + depth);
2931 goto out;
2932 }
2933
2934 /* case a */
2935 memcpy(&orig_ex, ex, sizeof(orig_ex));
2936 ex->ee_len = cpu_to_le16(split - ee_block);
2937 if (split_flag & EXT4_EXT_MARK_UNINIT1)
2938 ext4_ext_mark_uninitialized(ex);
2939
2940 /*
2941 * path may lead to new leaf, not to original leaf any more
2942 * after ext4_ext_insert_extent() returns,
2943 */
2944 err = ext4_ext_dirty(handle, inode, path + depth);
2945 if (err)
2946 goto fix_extent_len;
2947
2948 ex2 = &newex;
2949 ex2->ee_block = cpu_to_le32(split);
2950 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
2951 ext4_ext_store_pblock(ex2, newblock);
2952 if (split_flag & EXT4_EXT_MARK_UNINIT2)
2953 ext4_ext_mark_uninitialized(ex2);
2954
2955 err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
2956 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
2957 err = ext4_ext_zeroout(inode, &orig_ex);
2958 if (err)
2959 goto fix_extent_len;
2960 /* update the extent length and mark as initialized */
2961 ex->ee_len = cpu_to_le16(ee_len);
2962 ext4_ext_try_to_merge(inode, path, ex);
2963 err = ext4_ext_dirty(handle, inode, path + depth);
2964 goto out;
2965 } else if (err)
2966 goto fix_extent_len;
2967
2968out:
2969 ext4_ext_show_leaf(inode, path);
2970 return err;
2971
2972fix_extent_len:
2973 ex->ee_len = orig_ex.ee_len;
2974 ext4_ext_dirty(handle, inode, path + depth);
2975 return err;
2976}
2977
2978/*
2979 * ext4_split_extents() splits an extent and mark extent which is covered
2980 * by @map as split_flags indicates
2981 *
2982 * It may result in splitting the extent into multiple extents (upto three)
2983 * There are three possibilities:
2984 * a> There is no split required
2985 * b> Splits in two extents: Split is happening at either end of the extent
2986 * c> Splits in three extents: Somone is splitting in middle of the extent
2987 *
2988 */
2989static int ext4_split_extent(handle_t *handle,
2990 struct inode *inode,
2991 struct ext4_ext_path *path,
2992 struct ext4_map_blocks *map,
2993 int split_flag,
2994 int flags)
2995{
2996 ext4_lblk_t ee_block;
2997 struct ext4_extent *ex;
2998 unsigned int ee_len, depth;
2999 int err = 0;
3000 int uninitialized;
3001 int split_flag1, flags1;
3002
3003 depth = ext_depth(inode);
3004 ex = path[depth].p_ext;
3005 ee_block = le32_to_cpu(ex->ee_block);
3006 ee_len = ext4_ext_get_actual_len(ex);
3007 uninitialized = ext4_ext_is_uninitialized(ex);
3008
3009 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3010 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT ?
3011 EXT4_EXT_MAY_ZEROOUT : 0;
3012 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3013 if (uninitialized)
3014 split_flag1 |= EXT4_EXT_MARK_UNINIT1 |
3015 EXT4_EXT_MARK_UNINIT2;
3016 err = ext4_split_extent_at(handle, inode, path,
3017 map->m_lblk + map->m_len, split_flag1, flags1);
3018 if (err)
3019 goto out;
3020 }
3021
3022 ext4_ext_drop_refs(path);
3023 path = ext4_ext_find_extent(inode, map->m_lblk, path);
3024 if (IS_ERR(path))
3025 return PTR_ERR(path);
3026
3027 if (map->m_lblk >= ee_block) {
3028 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT ?
3029 EXT4_EXT_MAY_ZEROOUT : 0;
3030 if (uninitialized)
3031 split_flag1 |= EXT4_EXT_MARK_UNINIT1;
3032 if (split_flag & EXT4_EXT_MARK_UNINIT2)
3033 split_flag1 |= EXT4_EXT_MARK_UNINIT2;
3034 err = ext4_split_extent_at(handle, inode, path,
3035 map->m_lblk, split_flag1, flags);
3036 if (err)
3037 goto out;
3038 }
3039
3040 ext4_ext_show_leaf(inode, path);
3041out:
3042 return err ? err : map->m_len;
3043}
3044
3045#define EXT4_EXT_ZERO_LEN 7
3046/*
3047 * This function is called by ext4_ext_map_blocks() if someone tries to write
3048 * to an uninitialized extent. It may result in splitting the uninitialized
3049 * extent into multiple extents (up to three - one initialized and two
3050 * uninitialized).
3051 * There are three possibilities:
3052 * a> There is no split required: Entire extent should be initialized
3053 * b> Splits in two extents: Write is happening at either end of the extent
3054 * c> Splits in three extents: Somone is writing in middle of the extent
3055 *
3056 * Pre-conditions:
3057 * - The extent pointed to by 'path' is uninitialized.
3058 * - The extent pointed to by 'path' contains a superset
3059 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3060 *
3061 * Post-conditions on success:
3062 * - the returned value is the number of blocks beyond map->l_lblk
3063 * that are allocated and initialized.
3064 * It is guaranteed to be >= map->m_len.
3065 */
3066static int ext4_ext_convert_to_initialized(handle_t *handle,
3067 struct inode *inode,
3068 struct ext4_map_blocks *map,
3069 struct ext4_ext_path *path)
3070{
3071 struct ext4_extent_header *eh;
3072 struct ext4_map_blocks split_map;
3073 struct ext4_extent zero_ex;
3074 struct ext4_extent *ex;
3075 ext4_lblk_t ee_block, eof_block;
3076 unsigned int ee_len, depth;
3077 int allocated;
3078 int err = 0;
3079 int split_flag = 0;
3080
3081 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3082 "block %llu, max_blocks %u\n", inode->i_ino,
3083 (unsigned long long)map->m_lblk, map->m_len);
3084
3085 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3086 inode->i_sb->s_blocksize_bits;
3087 if (eof_block < map->m_lblk + map->m_len)
3088 eof_block = map->m_lblk + map->m_len;
3089
3090 depth = ext_depth(inode);
3091 eh = path[depth].p_hdr;
3092 ex = path[depth].p_ext;
3093 ee_block = le32_to_cpu(ex->ee_block);
3094 ee_len = ext4_ext_get_actual_len(ex);
3095 allocated = ee_len - (map->m_lblk - ee_block);
3096
3097 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3098
3099 /* Pre-conditions */
3100 BUG_ON(!ext4_ext_is_uninitialized(ex));
3101 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3102
3103 /*
3104 * Attempt to transfer newly initialized blocks from the currently
3105 * uninitialized extent to its left neighbor. This is much cheaper
3106 * than an insertion followed by a merge as those involve costly
3107 * memmove() calls. This is the common case in steady state for
3108 * workloads doing fallocate(FALLOC_FL_KEEP_SIZE) followed by append
3109 * writes.
3110 *
3111 * Limitations of the current logic:
3112 * - L1: we only deal with writes at the start of the extent.
3113 * The approach could be extended to writes at the end
3114 * of the extent but this scenario was deemed less common.
3115 * - L2: we do not deal with writes covering the whole extent.
3116 * This would require removing the extent if the transfer
3117 * is possible.
3118 * - L3: we only attempt to merge with an extent stored in the
3119 * same extent tree node.
3120 */
3121 if ((map->m_lblk == ee_block) && /*L1*/
3122 (map->m_len < ee_len) && /*L2*/
3123 (ex > EXT_FIRST_EXTENT(eh))) { /*L3*/
3124 struct ext4_extent *prev_ex;
3125 ext4_lblk_t prev_lblk;
3126 ext4_fsblk_t prev_pblk, ee_pblk;
3127 unsigned int prev_len, write_len;
3128
3129 prev_ex = ex - 1;
3130 prev_lblk = le32_to_cpu(prev_ex->ee_block);
3131 prev_len = ext4_ext_get_actual_len(prev_ex);
3132 prev_pblk = ext4_ext_pblock(prev_ex);
3133 ee_pblk = ext4_ext_pblock(ex);
3134 write_len = map->m_len;
3135
3136 /*
3137 * A transfer of blocks from 'ex' to 'prev_ex' is allowed
3138 * upon those conditions:
3139 * - C1: prev_ex is initialized,
3140 * - C2: prev_ex is logically abutting ex,
3141 * - C3: prev_ex is physically abutting ex,
3142 * - C4: prev_ex can receive the additional blocks without
3143 * overflowing the (initialized) length limit.
3144 */
3145 if ((!ext4_ext_is_uninitialized(prev_ex)) && /*C1*/
3146 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3147 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3148 (prev_len < (EXT_INIT_MAX_LEN - write_len))) { /*C4*/
3149 err = ext4_ext_get_access(handle, inode, path + depth);
3150 if (err)
3151 goto out;
3152
3153 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3154 map, ex, prev_ex);
3155
3156 /* Shift the start of ex by 'write_len' blocks */
3157 ex->ee_block = cpu_to_le32(ee_block + write_len);
3158 ext4_ext_store_pblock(ex, ee_pblk + write_len);
3159 ex->ee_len = cpu_to_le16(ee_len - write_len);
3160 ext4_ext_mark_uninitialized(ex); /* Restore the flag */
3161
3162 /* Extend prev_ex by 'write_len' blocks */
3163 prev_ex->ee_len = cpu_to_le16(prev_len + write_len);
3164
3165 /* Mark the block containing both extents as dirty */
3166 ext4_ext_dirty(handle, inode, path + depth);
3167
3168 /* Update path to point to the right extent */
3169 path[depth].p_ext = prev_ex;
3170
3171 /* Result: number of initialized blocks past m_lblk */
3172 allocated = write_len;
3173 goto out;
3174 }
3175 }
3176
3177 WARN_ON(map->m_lblk < ee_block);
3178 /*
3179 * It is safe to convert extent to initialized via explicit
3180 * zeroout only if extent is fully insde i_size or new_size.
3181 */
3182 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3183
3184 /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
3185 if (ee_len <= 2*EXT4_EXT_ZERO_LEN &&
3186 (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3187 err = ext4_ext_zeroout(inode, ex);
3188 if (err)
3189 goto out;
3190
3191 err = ext4_ext_get_access(handle, inode, path + depth);
3192 if (err)
3193 goto out;
3194 ext4_ext_mark_initialized(ex);
3195 ext4_ext_try_to_merge(inode, path, ex);
3196 err = ext4_ext_dirty(handle, inode, path + depth);
3197 goto out;
3198 }
3199
3200 /*
3201 * four cases:
3202 * 1. split the extent into three extents.
3203 * 2. split the extent into two extents, zeroout the first half.
3204 * 3. split the extent into two extents, zeroout the second half.
3205 * 4. split the extent into two extents with out zeroout.
3206 */
3207 split_map.m_lblk = map->m_lblk;
3208 split_map.m_len = map->m_len;
3209
3210 if (allocated > map->m_len) {
3211 if (allocated <= EXT4_EXT_ZERO_LEN &&
3212 (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3213 /* case 3 */
3214 zero_ex.ee_block =
3215 cpu_to_le32(map->m_lblk);
3216 zero_ex.ee_len = cpu_to_le16(allocated);
3217 ext4_ext_store_pblock(&zero_ex,
3218 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
3219 err = ext4_ext_zeroout(inode, &zero_ex);
3220 if (err)
3221 goto out;
3222 split_map.m_lblk = map->m_lblk;
3223 split_map.m_len = allocated;
3224 } else if ((map->m_lblk - ee_block + map->m_len <
3225 EXT4_EXT_ZERO_LEN) &&
3226 (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3227 /* case 2 */
3228 if (map->m_lblk != ee_block) {
3229 zero_ex.ee_block = ex->ee_block;
3230 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
3231 ee_block);
3232 ext4_ext_store_pblock(&zero_ex,
3233 ext4_ext_pblock(ex));
3234 err = ext4_ext_zeroout(inode, &zero_ex);
3235 if (err)
3236 goto out;
3237 }
3238
3239 split_map.m_lblk = ee_block;
3240 split_map.m_len = map->m_lblk - ee_block + map->m_len;
3241 allocated = map->m_len;
3242 }
3243 }
3244
3245 allocated = ext4_split_extent(handle, inode, path,
3246 &split_map, split_flag, 0);
3247 if (allocated < 0)
3248 err = allocated;
3249
3250out:
3251 return err ? err : allocated;
3252}
3253
3254/*
3255 * This function is called by ext4_ext_map_blocks() from
3256 * ext4_get_blocks_dio_write() when DIO to write
3257 * to an uninitialized extent.
3258 *
3259 * Writing to an uninitialized extent may result in splitting the uninitialized
3260 * extent into multiple /initialized uninitialized extents (up to three)
3261 * There are three possibilities:
3262 * a> There is no split required: Entire extent should be uninitialized
3263 * b> Splits in two extents: Write is happening at either end of the extent
3264 * c> Splits in three extents: Somone is writing in middle of the extent
3265 *
3266 * One of more index blocks maybe needed if the extent tree grow after
3267 * the uninitialized extent split. To prevent ENOSPC occur at the IO
3268 * complete, we need to split the uninitialized extent before DIO submit
3269 * the IO. The uninitialized extent called at this time will be split
3270 * into three uninitialized extent(at most). After IO complete, the part
3271 * being filled will be convert to initialized by the end_io callback function
3272 * via ext4_convert_unwritten_extents().
3273 *
3274 * Returns the size of uninitialized extent to be written on success.
3275 */
3276static int ext4_split_unwritten_extents(handle_t *handle,
3277 struct inode *inode,
3278 struct ext4_map_blocks *map,
3279 struct ext4_ext_path *path,
3280 int flags)
3281{
3282 ext4_lblk_t eof_block;
3283 ext4_lblk_t ee_block;
3284 struct ext4_extent *ex;
3285 unsigned int ee_len;
3286 int split_flag = 0, depth;
3287
3288 ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
3289 "block %llu, max_blocks %u\n", inode->i_ino,
3290 (unsigned long long)map->m_lblk, map->m_len);
3291
3292 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3293 inode->i_sb->s_blocksize_bits;
3294 if (eof_block < map->m_lblk + map->m_len)
3295 eof_block = map->m_lblk + map->m_len;
3296 /*
3297 * It is safe to convert extent to initialized via explicit
3298 * zeroout only if extent is fully insde i_size or new_size.
3299 */
3300 depth = ext_depth(inode);
3301 ex = path[depth].p_ext;
3302 ee_block = le32_to_cpu(ex->ee_block);
3303 ee_len = ext4_ext_get_actual_len(ex);
3304
3305 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3306 split_flag |= EXT4_EXT_MARK_UNINIT2;
3307
3308 flags |= EXT4_GET_BLOCKS_PRE_IO;
3309 return ext4_split_extent(handle, inode, path, map, split_flag, flags);
3310}
3311
3312static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3313 struct inode *inode,
3314 struct ext4_ext_path *path)
3315{
3316 struct ext4_extent *ex;
3317 int depth;
3318 int err = 0;
3319
3320 depth = ext_depth(inode);
3321 ex = path[depth].p_ext;
3322
3323 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3324 "block %llu, max_blocks %u\n", inode->i_ino,
3325 (unsigned long long)le32_to_cpu(ex->ee_block),
3326 ext4_ext_get_actual_len(ex));
3327
3328 err = ext4_ext_get_access(handle, inode, path + depth);
3329 if (err)
3330 goto out;
3331 /* first mark the extent as initialized */
3332 ext4_ext_mark_initialized(ex);
3333
3334 /* note: ext4_ext_correct_indexes() isn't needed here because
3335 * borders are not changed
3336 */
3337 ext4_ext_try_to_merge(inode, path, ex);
3338
3339 /* Mark modified extent as dirty */
3340 err = ext4_ext_dirty(handle, inode, path + depth);
3341out:
3342 ext4_ext_show_leaf(inode, path);
3343 return err;
3344}
3345
3346static void unmap_underlying_metadata_blocks(struct block_device *bdev,
3347 sector_t block, int count)
3348{
3349 int i;
3350 for (i = 0; i < count; i++)
3351 unmap_underlying_metadata(bdev, block + i);
3352}
3353
3354/*
3355 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3356 */
3357static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3358 ext4_lblk_t lblk,
3359 struct ext4_ext_path *path,
3360 unsigned int len)
3361{
3362 int i, depth;
3363 struct ext4_extent_header *eh;
3364 struct ext4_extent *last_ex;
3365
3366 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3367 return 0;
3368
3369 depth = ext_depth(inode);
3370 eh = path[depth].p_hdr;
3371
3372 /*
3373 * We're going to remove EOFBLOCKS_FL entirely in future so we
3374 * do not care for this case anymore. Simply remove the flag
3375 * if there are no extents.
3376 */
3377 if (unlikely(!eh->eh_entries))
3378 goto out;
3379 last_ex = EXT_LAST_EXTENT(eh);
3380 /*
3381 * We should clear the EOFBLOCKS_FL flag if we are writing the
3382 * last block in the last extent in the file. We test this by
3383 * first checking to see if the caller to
3384 * ext4_ext_get_blocks() was interested in the last block (or
3385 * a block beyond the last block) in the current extent. If
3386 * this turns out to be false, we can bail out from this
3387 * function immediately.
3388 */
3389 if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3390 ext4_ext_get_actual_len(last_ex))
3391 return 0;
3392 /*
3393 * If the caller does appear to be planning to write at or
3394 * beyond the end of the current extent, we then test to see
3395 * if the current extent is the last extent in the file, by
3396 * checking to make sure it was reached via the rightmost node
3397 * at each level of the tree.
3398 */
3399 for (i = depth-1; i >= 0; i--)
3400 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3401 return 0;
3402out:
3403 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3404 return ext4_mark_inode_dirty(handle, inode);
3405}
3406
3407/**
3408 * ext4_find_delalloc_range: find delayed allocated block in the given range.
3409 *
3410 * Goes through the buffer heads in the range [lblk_start, lblk_end] and returns
3411 * whether there are any buffers marked for delayed allocation. It returns '1'
3412 * on the first delalloc'ed buffer head found. If no buffer head in the given
3413 * range is marked for delalloc, it returns 0.
3414 * lblk_start should always be <= lblk_end.
3415 * search_hint_reverse is to indicate that searching in reverse from lblk_end to
3416 * lblk_start might be more efficient (i.e., we will likely hit the delalloc'ed
3417 * block sooner). This is useful when blocks are truncated sequentially from
3418 * lblk_start towards lblk_end.
3419 */
3420static int ext4_find_delalloc_range(struct inode *inode,
3421 ext4_lblk_t lblk_start,
3422 ext4_lblk_t lblk_end,
3423 int search_hint_reverse)
3424{
3425 struct address_space *mapping = inode->i_mapping;
3426 struct buffer_head *head, *bh = NULL;
3427 struct page *page;
3428 ext4_lblk_t i, pg_lblk;
3429 pgoff_t index;
3430
3431 if (!test_opt(inode->i_sb, DELALLOC))
3432 return 0;
3433
3434 /* reverse search wont work if fs block size is less than page size */
3435 if (inode->i_blkbits < PAGE_CACHE_SHIFT)
3436 search_hint_reverse = 0;
3437
3438 if (search_hint_reverse)
3439 i = lblk_end;
3440 else
3441 i = lblk_start;
3442
3443 index = i >> (PAGE_CACHE_SHIFT - inode->i_blkbits);
3444
3445 while ((i >= lblk_start) && (i <= lblk_end)) {
3446 page = find_get_page(mapping, index);
3447 if (!page)
3448 goto nextpage;
3449
3450 if (!page_has_buffers(page))
3451 goto nextpage;
3452
3453 head = page_buffers(page);
3454 if (!head)
3455 goto nextpage;
3456
3457 bh = head;
3458 pg_lblk = index << (PAGE_CACHE_SHIFT -
3459 inode->i_blkbits);
3460 do {
3461 if (unlikely(pg_lblk < lblk_start)) {
3462 /*
3463 * This is possible when fs block size is less
3464 * than page size and our cluster starts/ends in
3465 * middle of the page. So we need to skip the
3466 * initial few blocks till we reach the 'lblk'
3467 */
3468 pg_lblk++;
3469 continue;
3470 }
3471
3472 /* Check if the buffer is delayed allocated and that it
3473 * is not yet mapped. (when da-buffers are mapped during
3474 * their writeout, their da_mapped bit is set.)
3475 */
3476 if (buffer_delay(bh) && !buffer_da_mapped(bh)) {
3477 page_cache_release(page);
3478 trace_ext4_find_delalloc_range(inode,
3479 lblk_start, lblk_end,
3480 search_hint_reverse,
3481 1, i);
3482 return 1;
3483 }
3484 if (search_hint_reverse)
3485 i--;
3486 else
3487 i++;
3488 } while ((i >= lblk_start) && (i <= lblk_end) &&
3489 ((bh = bh->b_this_page) != head));
3490nextpage:
3491 if (page)
3492 page_cache_release(page);
3493 /*
3494 * Move to next page. 'i' will be the first lblk in the next
3495 * page.
3496 */
3497 if (search_hint_reverse)
3498 index--;
3499 else
3500 index++;
3501 i = index << (PAGE_CACHE_SHIFT - inode->i_blkbits);
3502 }
3503
3504 trace_ext4_find_delalloc_range(inode, lblk_start, lblk_end,
3505 search_hint_reverse, 0, 0);
3506 return 0;
3507}
3508
3509int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk,
3510 int search_hint_reverse)
3511{
3512 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3513 ext4_lblk_t lblk_start, lblk_end;
3514 lblk_start = lblk & (~(sbi->s_cluster_ratio - 1));
3515 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3516
3517 return ext4_find_delalloc_range(inode, lblk_start, lblk_end,
3518 search_hint_reverse);
3519}
3520
3521/**
3522 * Determines how many complete clusters (out of those specified by the 'map')
3523 * are under delalloc and were reserved quota for.
3524 * This function is called when we are writing out the blocks that were
3525 * originally written with their allocation delayed, but then the space was
3526 * allocated using fallocate() before the delayed allocation could be resolved.
3527 * The cases to look for are:
3528 * ('=' indicated delayed allocated blocks
3529 * '-' indicates non-delayed allocated blocks)
3530 * (a) partial clusters towards beginning and/or end outside of allocated range
3531 * are not delalloc'ed.
3532 * Ex:
3533 * |----c---=|====c====|====c====|===-c----|
3534 * |++++++ allocated ++++++|
3535 * ==> 4 complete clusters in above example
3536 *
3537 * (b) partial cluster (outside of allocated range) towards either end is
3538 * marked for delayed allocation. In this case, we will exclude that
3539 * cluster.
3540 * Ex:
3541 * |----====c========|========c========|
3542 * |++++++ allocated ++++++|
3543 * ==> 1 complete clusters in above example
3544 *
3545 * Ex:
3546 * |================c================|
3547 * |++++++ allocated ++++++|
3548 * ==> 0 complete clusters in above example
3549 *
3550 * The ext4_da_update_reserve_space will be called only if we
3551 * determine here that there were some "entire" clusters that span
3552 * this 'allocated' range.
3553 * In the non-bigalloc case, this function will just end up returning num_blks
3554 * without ever calling ext4_find_delalloc_range.
3555 */
3556static unsigned int
3557get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3558 unsigned int num_blks)
3559{
3560 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3561 ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3562 ext4_lblk_t lblk_from, lblk_to, c_offset;
3563 unsigned int allocated_clusters = 0;
3564
3565 alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3566 alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3567
3568 /* max possible clusters for this allocation */
3569 allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3570
3571 trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3572
3573 /* Check towards left side */
3574 c_offset = lblk_start & (sbi->s_cluster_ratio - 1);
3575 if (c_offset) {
3576 lblk_from = lblk_start & (~(sbi->s_cluster_ratio - 1));
3577 lblk_to = lblk_from + c_offset - 1;
3578
3579 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to, 0))
3580 allocated_clusters--;
3581 }
3582
3583 /* Now check towards right. */
3584 c_offset = (lblk_start + num_blks) & (sbi->s_cluster_ratio - 1);
3585 if (allocated_clusters && c_offset) {
3586 lblk_from = lblk_start + num_blks;
3587 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3588
3589 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to, 0))
3590 allocated_clusters--;
3591 }
3592
3593 return allocated_clusters;
3594}
3595
3596static int
3597ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
3598 struct ext4_map_blocks *map,
3599 struct ext4_ext_path *path, int flags,
3600 unsigned int allocated, ext4_fsblk_t newblock)
3601{
3602 int ret = 0;
3603 int err = 0;
3604 ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
3605
3606 ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical "
3607 "block %llu, max_blocks %u, flags %x, allocated %u\n",
3608 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
3609 flags, allocated);
3610 ext4_ext_show_leaf(inode, path);
3611
3612 trace_ext4_ext_handle_uninitialized_extents(inode, map, allocated,
3613 newblock);
3614
3615 /* get_block() before submit the IO, split the extent */
3616 if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
3617 ret = ext4_split_unwritten_extents(handle, inode, map,
3618 path, flags);
3619 /*
3620 * Flag the inode(non aio case) or end_io struct (aio case)
3621 * that this IO needs to conversion to written when IO is
3622 * completed
3623 */
3624 if (io)
3625 ext4_set_io_unwritten_flag(inode, io);
3626 else
3627 ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3628 if (ext4_should_dioread_nolock(inode))
3629 map->m_flags |= EXT4_MAP_UNINIT;
3630 goto out;
3631 }
3632 /* IO end_io complete, convert the filled extent to written */
3633 if ((flags & EXT4_GET_BLOCKS_CONVERT)) {
3634 ret = ext4_convert_unwritten_extents_endio(handle, inode,
3635 path);
3636 if (ret >= 0) {
3637 ext4_update_inode_fsync_trans(handle, inode, 1);
3638 err = check_eofblocks_fl(handle, inode, map->m_lblk,
3639 path, map->m_len);
3640 } else
3641 err = ret;
3642 goto out2;
3643 }
3644 /* buffered IO case */
3645 /*
3646 * repeat fallocate creation request
3647 * we already have an unwritten extent
3648 */
3649 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)
3650 goto map_out;
3651
3652 /* buffered READ or buffered write_begin() lookup */
3653 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3654 /*
3655 * We have blocks reserved already. We
3656 * return allocated blocks so that delalloc
3657 * won't do block reservation for us. But
3658 * the buffer head will be unmapped so that
3659 * a read from the block returns 0s.
3660 */
3661 map->m_flags |= EXT4_MAP_UNWRITTEN;
3662 goto out1;
3663 }
3664
3665 /* buffered write, writepage time, convert*/
3666 ret = ext4_ext_convert_to_initialized(handle, inode, map, path);
3667 if (ret >= 0)
3668 ext4_update_inode_fsync_trans(handle, inode, 1);
3669out:
3670 if (ret <= 0) {
3671 err = ret;
3672 goto out2;
3673 } else
3674 allocated = ret;
3675 map->m_flags |= EXT4_MAP_NEW;
3676 /*
3677 * if we allocated more blocks than requested
3678 * we need to make sure we unmap the extra block
3679 * allocated. The actual needed block will get
3680 * unmapped later when we find the buffer_head marked
3681 * new.
3682 */
3683 if (allocated > map->m_len) {
3684 unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
3685 newblock + map->m_len,
3686 allocated - map->m_len);
3687 allocated = map->m_len;
3688 }
3689
3690 /*
3691 * If we have done fallocate with the offset that is already
3692 * delayed allocated, we would have block reservation
3693 * and quota reservation done in the delayed write path.
3694 * But fallocate would have already updated quota and block
3695 * count for this offset. So cancel these reservation
3696 */
3697 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
3698 unsigned int reserved_clusters;
3699 reserved_clusters = get_reserved_cluster_alloc(inode,
3700 map->m_lblk, map->m_len);
3701 if (reserved_clusters)
3702 ext4_da_update_reserve_space(inode,
3703 reserved_clusters,
3704 0);
3705 }
3706
3707map_out:
3708 map->m_flags |= EXT4_MAP_MAPPED;
3709 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
3710 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
3711 map->m_len);
3712 if (err < 0)
3713 goto out2;
3714 }
3715out1:
3716 if (allocated > map->m_len)
3717 allocated = map->m_len;
3718 ext4_ext_show_leaf(inode, path);
3719 map->m_pblk = newblock;
3720 map->m_len = allocated;
3721out2:
3722 if (path) {
3723 ext4_ext_drop_refs(path);
3724 kfree(path);
3725 }
3726 return err ? err : allocated;
3727}
3728
3729/*
3730 * get_implied_cluster_alloc - check to see if the requested
3731 * allocation (in the map structure) overlaps with a cluster already
3732 * allocated in an extent.
3733 * @sb The filesystem superblock structure
3734 * @map The requested lblk->pblk mapping
3735 * @ex The extent structure which might contain an implied
3736 * cluster allocation
3737 *
3738 * This function is called by ext4_ext_map_blocks() after we failed to
3739 * find blocks that were already in the inode's extent tree. Hence,
3740 * we know that the beginning of the requested region cannot overlap
3741 * the extent from the inode's extent tree. There are three cases we
3742 * want to catch. The first is this case:
3743 *
3744 * |--- cluster # N--|
3745 * |--- extent ---| |---- requested region ---|
3746 * |==========|
3747 *
3748 * The second case that we need to test for is this one:
3749 *
3750 * |--------- cluster # N ----------------|
3751 * |--- requested region --| |------- extent ----|
3752 * |=======================|
3753 *
3754 * The third case is when the requested region lies between two extents
3755 * within the same cluster:
3756 * |------------- cluster # N-------------|
3757 * |----- ex -----| |---- ex_right ----|
3758 * |------ requested region ------|
3759 * |================|
3760 *
3761 * In each of the above cases, we need to set the map->m_pblk and
3762 * map->m_len so it corresponds to the return the extent labelled as
3763 * "|====|" from cluster #N, since it is already in use for data in
3764 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
3765 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
3766 * as a new "allocated" block region. Otherwise, we will return 0 and
3767 * ext4_ext_map_blocks() will then allocate one or more new clusters
3768 * by calling ext4_mb_new_blocks().
3769 */
3770static int get_implied_cluster_alloc(struct super_block *sb,
3771 struct ext4_map_blocks *map,
3772 struct ext4_extent *ex,
3773 struct ext4_ext_path *path)
3774{
3775 struct ext4_sb_info *sbi = EXT4_SB(sb);
3776 ext4_lblk_t c_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
3777 ext4_lblk_t ex_cluster_start, ex_cluster_end;
3778 ext4_lblk_t rr_cluster_start;
3779 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
3780 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
3781 unsigned short ee_len = ext4_ext_get_actual_len(ex);
3782
3783 /* The extent passed in that we are trying to match */
3784 ex_cluster_start = EXT4_B2C(sbi, ee_block);
3785 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
3786
3787 /* The requested region passed into ext4_map_blocks() */
3788 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
3789
3790 if ((rr_cluster_start == ex_cluster_end) ||
3791 (rr_cluster_start == ex_cluster_start)) {
3792 if (rr_cluster_start == ex_cluster_end)
3793 ee_start += ee_len - 1;
3794 map->m_pblk = (ee_start & ~(sbi->s_cluster_ratio - 1)) +
3795 c_offset;
3796 map->m_len = min(map->m_len,
3797 (unsigned) sbi->s_cluster_ratio - c_offset);
3798 /*
3799 * Check for and handle this case:
3800 *
3801 * |--------- cluster # N-------------|
3802 * |------- extent ----|
3803 * |--- requested region ---|
3804 * |===========|
3805 */
3806
3807 if (map->m_lblk < ee_block)
3808 map->m_len = min(map->m_len, ee_block - map->m_lblk);
3809
3810 /*
3811 * Check for the case where there is already another allocated
3812 * block to the right of 'ex' but before the end of the cluster.
3813 *
3814 * |------------- cluster # N-------------|
3815 * |----- ex -----| |---- ex_right ----|
3816 * |------ requested region ------|
3817 * |================|
3818 */
3819 if (map->m_lblk > ee_block) {
3820 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
3821 map->m_len = min(map->m_len, next - map->m_lblk);
3822 }
3823
3824 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
3825 return 1;
3826 }
3827
3828 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
3829 return 0;
3830}
3831
3832
3833/*
3834 * Block allocation/map/preallocation routine for extents based files
3835 *
3836 *
3837 * Need to be called with
3838 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
3839 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
3840 *
3841 * return > 0, number of of blocks already mapped/allocated
3842 * if create == 0 and these are pre-allocated blocks
3843 * buffer head is unmapped
3844 * otherwise blocks are mapped
3845 *
3846 * return = 0, if plain look up failed (blocks have not been allocated)
3847 * buffer head is unmapped
3848 *
3849 * return < 0, error case.
3850 */
3851int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3852 struct ext4_map_blocks *map, int flags)
3853{
3854 struct ext4_ext_path *path = NULL;
3855 struct ext4_extent newex, *ex, *ex2;
3856 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3857 ext4_fsblk_t newblock = 0;
3858 int free_on_err = 0, err = 0, depth, ret;
3859 unsigned int allocated = 0, offset = 0;
3860 unsigned int allocated_clusters = 0;
3861 struct ext4_allocation_request ar;
3862 ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
3863 ext4_lblk_t cluster_offset;
3864
3865 ext_debug("blocks %u/%u requested for inode %lu\n",
3866 map->m_lblk, map->m_len, inode->i_ino);
3867 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
3868
3869 /* check in cache */
3870 if (ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
3871 if (!newex.ee_start_lo && !newex.ee_start_hi) {
3872 if ((sbi->s_cluster_ratio > 1) &&
3873 ext4_find_delalloc_cluster(inode, map->m_lblk, 0))
3874 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3875
3876 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3877 /*
3878 * block isn't allocated yet and
3879 * user doesn't want to allocate it
3880 */
3881 goto out2;
3882 }
3883 /* we should allocate requested block */
3884 } else {
3885 /* block is already allocated */
3886 if (sbi->s_cluster_ratio > 1)
3887 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3888 newblock = map->m_lblk
3889 - le32_to_cpu(newex.ee_block)
3890 + ext4_ext_pblock(&newex);
3891 /* number of remaining blocks in the extent */
3892 allocated = ext4_ext_get_actual_len(&newex) -
3893 (map->m_lblk - le32_to_cpu(newex.ee_block));
3894 goto out;
3895 }
3896 }
3897
3898 /* find extent for this block */
3899 path = ext4_ext_find_extent(inode, map->m_lblk, NULL);
3900 if (IS_ERR(path)) {
3901 err = PTR_ERR(path);
3902 path = NULL;
3903 goto out2;
3904 }
3905
3906 depth = ext_depth(inode);
3907
3908 /*
3909 * consistent leaf must not be empty;
3910 * this situation is possible, though, _during_ tree modification;
3911 * this is why assert can't be put in ext4_ext_find_extent()
3912 */
3913 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
3914 EXT4_ERROR_INODE(inode, "bad extent address "
3915 "lblock: %lu, depth: %d pblock %lld",
3916 (unsigned long) map->m_lblk, depth,
3917 path[depth].p_block);
3918 err = -EIO;
3919 goto out2;
3920 }
3921
3922 ex = path[depth].p_ext;
3923 if (ex) {
3924 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
3925 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
3926 unsigned short ee_len;
3927
3928 /*
3929 * Uninitialized extents are treated as holes, except that
3930 * we split out initialized portions during a write.
3931 */
3932 ee_len = ext4_ext_get_actual_len(ex);
3933
3934 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
3935
3936 /* if found extent covers block, simply return it */
3937 if (in_range(map->m_lblk, ee_block, ee_len)) {
3938 newblock = map->m_lblk - ee_block + ee_start;
3939 /* number of remaining blocks in the extent */
3940 allocated = ee_len - (map->m_lblk - ee_block);
3941 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
3942 ee_block, ee_len, newblock);
3943
3944 /*
3945 * Do not put uninitialized extent
3946 * in the cache
3947 */
3948 if (!ext4_ext_is_uninitialized(ex)) {
3949 ext4_ext_put_in_cache(inode, ee_block,
3950 ee_len, ee_start);
3951 goto out;
3952 }
3953 ret = ext4_ext_handle_uninitialized_extents(
3954 handle, inode, map, path, flags,
3955 allocated, newblock);
3956 return ret;
3957 }
3958 }
3959
3960 if ((sbi->s_cluster_ratio > 1) &&
3961 ext4_find_delalloc_cluster(inode, map->m_lblk, 0))
3962 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3963
3964 /*
3965 * requested block isn't allocated yet;
3966 * we couldn't try to create block if create flag is zero
3967 */
3968 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3969 /*
3970 * put just found gap into cache to speed up
3971 * subsequent requests
3972 */
3973 ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
3974 goto out2;
3975 }
3976
3977 /*
3978 * Okay, we need to do block allocation.
3979 */
3980 map->m_flags &= ~EXT4_MAP_FROM_CLUSTER;
3981 newex.ee_block = cpu_to_le32(map->m_lblk);
3982 cluster_offset = map->m_lblk & (sbi->s_cluster_ratio-1);
3983
3984 /*
3985 * If we are doing bigalloc, check to see if the extent returned
3986 * by ext4_ext_find_extent() implies a cluster we can use.
3987 */
3988 if (cluster_offset && ex &&
3989 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
3990 ar.len = allocated = map->m_len;
3991 newblock = map->m_pblk;
3992 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
3993 goto got_allocated_blocks;
3994 }
3995
3996 /* find neighbour allocated blocks */
3997 ar.lleft = map->m_lblk;
3998 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
3999 if (err)
4000 goto out2;
4001 ar.lright = map->m_lblk;
4002 ex2 = NULL;
4003 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4004 if (err)
4005 goto out2;
4006
4007 /* Check if the extent after searching to the right implies a
4008 * cluster we can use. */
4009 if ((sbi->s_cluster_ratio > 1) && ex2 &&
4010 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
4011 ar.len = allocated = map->m_len;
4012 newblock = map->m_pblk;
4013 map->m_flags |= EXT4_MAP_FROM_CLUSTER;
4014 goto got_allocated_blocks;
4015 }
4016
4017 /*
4018 * See if request is beyond maximum number of blocks we can have in
4019 * a single extent. For an initialized extent this limit is
4020 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
4021 * EXT_UNINIT_MAX_LEN.
4022 */
4023 if (map->m_len > EXT_INIT_MAX_LEN &&
4024 !(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
4025 map->m_len = EXT_INIT_MAX_LEN;
4026 else if (map->m_len > EXT_UNINIT_MAX_LEN &&
4027 (flags & EXT4_GET_BLOCKS_UNINIT_EXT))
4028 map->m_len = EXT_UNINIT_MAX_LEN;
4029
4030 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4031 newex.ee_len = cpu_to_le16(map->m_len);
4032 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4033 if (err)
4034 allocated = ext4_ext_get_actual_len(&newex);
4035 else
4036 allocated = map->m_len;
4037
4038 /* allocate new block */
4039 ar.inode = inode;
4040 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4041 ar.logical = map->m_lblk;
4042 /*
4043 * We calculate the offset from the beginning of the cluster
4044 * for the logical block number, since when we allocate a
4045 * physical cluster, the physical block should start at the
4046 * same offset from the beginning of the cluster. This is
4047 * needed so that future calls to get_implied_cluster_alloc()
4048 * work correctly.
4049 */
4050 offset = map->m_lblk & (sbi->s_cluster_ratio - 1);
4051 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4052 ar.goal -= offset;
4053 ar.logical -= offset;
4054 if (S_ISREG(inode->i_mode))
4055 ar.flags = EXT4_MB_HINT_DATA;
4056 else
4057 /* disable in-core preallocation for non-regular files */
4058 ar.flags = 0;
4059 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4060 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4061 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4062 if (!newblock)
4063 goto out2;
4064 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4065 ar.goal, newblock, allocated);
4066 free_on_err = 1;
4067 allocated_clusters = ar.len;
4068 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4069 if (ar.len > allocated)
4070 ar.len = allocated;
4071
4072got_allocated_blocks:
4073 /* try to insert new extent into found leaf and return */
4074 ext4_ext_store_pblock(&newex, newblock + offset);
4075 newex.ee_len = cpu_to_le16(ar.len);
4076 /* Mark uninitialized */
4077 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
4078 ext4_ext_mark_uninitialized(&newex);
4079 /*
4080 * io_end structure was created for every IO write to an
4081 * uninitialized extent. To avoid unnecessary conversion,
4082 * here we flag the IO that really needs the conversion.
4083 * For non asycn direct IO case, flag the inode state
4084 * that we need to perform conversion when IO is done.
4085 */
4086 if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
4087 if (io)
4088 ext4_set_io_unwritten_flag(inode, io);
4089 else
4090 ext4_set_inode_state(inode,
4091 EXT4_STATE_DIO_UNWRITTEN);
4092 }
4093 if (ext4_should_dioread_nolock(inode))
4094 map->m_flags |= EXT4_MAP_UNINIT;
4095 }
4096
4097 err = 0;
4098 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4099 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4100 path, ar.len);
4101 if (!err)
4102 err = ext4_ext_insert_extent(handle, inode, path,
4103 &newex, flags);
4104 if (err && free_on_err) {
4105 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4106 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4107 /* free data blocks we just allocated */
4108 /* not a good idea to call discard here directly,
4109 * but otherwise we'd need to call it every free() */
4110 ext4_discard_preallocations(inode);
4111 ext4_free_blocks(handle, inode, NULL, ext4_ext_pblock(&newex),
4112 ext4_ext_get_actual_len(&newex), fb_flags);
4113 goto out2;
4114 }
4115
4116 /* previous routine could use block we allocated */
4117 newblock = ext4_ext_pblock(&newex);
4118 allocated = ext4_ext_get_actual_len(&newex);
4119 if (allocated > map->m_len)
4120 allocated = map->m_len;
4121 map->m_flags |= EXT4_MAP_NEW;
4122
4123 /*
4124 * Update reserved blocks/metadata blocks after successful
4125 * block allocation which had been deferred till now.
4126 */
4127 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4128 unsigned int reserved_clusters;
4129 /*
4130 * Check how many clusters we had reserved this allocated range
4131 */
4132 reserved_clusters = get_reserved_cluster_alloc(inode,
4133 map->m_lblk, allocated);
4134 if (map->m_flags & EXT4_MAP_FROM_CLUSTER) {
4135 if (reserved_clusters) {
4136 /*
4137 * We have clusters reserved for this range.
4138 * But since we are not doing actual allocation
4139 * and are simply using blocks from previously
4140 * allocated cluster, we should release the
4141 * reservation and not claim quota.
4142 */
4143 ext4_da_update_reserve_space(inode,
4144 reserved_clusters, 0);
4145 }
4146 } else {
4147 BUG_ON(allocated_clusters < reserved_clusters);
4148 /* We will claim quota for all newly allocated blocks.*/
4149 ext4_da_update_reserve_space(inode, allocated_clusters,
4150 1);
4151 if (reserved_clusters < allocated_clusters) {
4152 struct ext4_inode_info *ei = EXT4_I(inode);
4153 int reservation = allocated_clusters -
4154 reserved_clusters;
4155 /*
4156 * It seems we claimed few clusters outside of
4157 * the range of this allocation. We should give
4158 * it back to the reservation pool. This can
4159 * happen in the following case:
4160 *
4161 * * Suppose s_cluster_ratio is 4 (i.e., each
4162 * cluster has 4 blocks. Thus, the clusters
4163 * are [0-3],[4-7],[8-11]...
4164 * * First comes delayed allocation write for
4165 * logical blocks 10 & 11. Since there were no
4166 * previous delayed allocated blocks in the
4167 * range [8-11], we would reserve 1 cluster
4168 * for this write.
4169 * * Next comes write for logical blocks 3 to 8.
4170 * In this case, we will reserve 2 clusters
4171 * (for [0-3] and [4-7]; and not for [8-11] as
4172 * that range has a delayed allocated blocks.
4173 * Thus total reserved clusters now becomes 3.
4174 * * Now, during the delayed allocation writeout
4175 * time, we will first write blocks [3-8] and
4176 * allocate 3 clusters for writing these
4177 * blocks. Also, we would claim all these
4178 * three clusters above.
4179 * * Now when we come here to writeout the
4180 * blocks [10-11], we would expect to claim
4181 * the reservation of 1 cluster we had made
4182 * (and we would claim it since there are no
4183 * more delayed allocated blocks in the range
4184 * [8-11]. But our reserved cluster count had
4185 * already gone to 0.
4186 *
4187 * Thus, at the step 4 above when we determine
4188 * that there are still some unwritten delayed
4189 * allocated blocks outside of our current
4190 * block range, we should increment the
4191 * reserved clusters count so that when the
4192 * remaining blocks finally gets written, we
4193 * could claim them.
4194 */
4195 dquot_reserve_block(inode,
4196 EXT4_C2B(sbi, reservation));
4197 spin_lock(&ei->i_block_reservation_lock);
4198 ei->i_reserved_data_blocks += reservation;
4199 spin_unlock(&ei->i_block_reservation_lock);
4200 }
4201 }
4202 }
4203
4204 /*
4205 * Cache the extent and update transaction to commit on fdatasync only
4206 * when it is _not_ an uninitialized extent.
4207 */
4208 if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) {
4209 ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock);
4210 ext4_update_inode_fsync_trans(handle, inode, 1);
4211 } else
4212 ext4_update_inode_fsync_trans(handle, inode, 0);
4213out:
4214 if (allocated > map->m_len)
4215 allocated = map->m_len;
4216 ext4_ext_show_leaf(inode, path);
4217 map->m_flags |= EXT4_MAP_MAPPED;
4218 map->m_pblk = newblock;
4219 map->m_len = allocated;
4220out2:
4221 if (path) {
4222 ext4_ext_drop_refs(path);
4223 kfree(path);
4224 }
4225
4226 trace_ext4_ext_map_blocks_exit(inode, map->m_lblk,
4227 newblock, map->m_len, err ? err : allocated);
4228
4229 return err ? err : allocated;
4230}
4231
4232void ext4_ext_truncate(struct inode *inode)
4233{
4234 struct address_space *mapping = inode->i_mapping;
4235 struct super_block *sb = inode->i_sb;
4236 ext4_lblk_t last_block;
4237 handle_t *handle;
4238 loff_t page_len;
4239 int err = 0;
4240
4241 /*
4242 * finish any pending end_io work so we won't run the risk of
4243 * converting any truncated blocks to initialized later
4244 */
4245 ext4_flush_completed_IO(inode);
4246
4247 /*
4248 * probably first extent we're gonna free will be last in block
4249 */
4250 err = ext4_writepage_trans_blocks(inode);
4251 handle = ext4_journal_start(inode, err);
4252 if (IS_ERR(handle))
4253 return;
4254
4255 if (inode->i_size % PAGE_CACHE_SIZE != 0) {
4256 page_len = PAGE_CACHE_SIZE -
4257 (inode->i_size & (PAGE_CACHE_SIZE - 1));
4258
4259 err = ext4_discard_partial_page_buffers(handle,
4260 mapping, inode->i_size, page_len, 0);
4261
4262 if (err)
4263 goto out_stop;
4264 }
4265
4266 if (ext4_orphan_add(handle, inode))
4267 goto out_stop;
4268
4269 down_write(&EXT4_I(inode)->i_data_sem);
4270 ext4_ext_invalidate_cache(inode);
4271
4272 ext4_discard_preallocations(inode);
4273
4274 /*
4275 * TODO: optimization is possible here.
4276 * Probably we need not scan at all,
4277 * because page truncation is enough.
4278 */
4279
4280 /* we have to know where to truncate from in crash case */
4281 EXT4_I(inode)->i_disksize = inode->i_size;
4282 ext4_mark_inode_dirty(handle, inode);
4283
4284 last_block = (inode->i_size + sb->s_blocksize - 1)
4285 >> EXT4_BLOCK_SIZE_BITS(sb);
4286 err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4287
4288 /* In a multi-transaction truncate, we only make the final
4289 * transaction synchronous.
4290 */
4291 if (IS_SYNC(inode))
4292 ext4_handle_sync(handle);
4293
4294 up_write(&EXT4_I(inode)->i_data_sem);
4295
4296out_stop:
4297 /*
4298 * If this was a simple ftruncate() and the file will remain alive,
4299 * then we need to clear up the orphan record which we created above.
4300 * However, if this was a real unlink then we were called by
4301 * ext4_delete_inode(), and we allow that function to clean up the
4302 * orphan info for us.
4303 */
4304 if (inode->i_nlink)
4305 ext4_orphan_del(handle, inode);
4306
4307 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4308 ext4_mark_inode_dirty(handle, inode);
4309 ext4_journal_stop(handle);
4310}
4311
4312static void ext4_falloc_update_inode(struct inode *inode,
4313 int mode, loff_t new_size, int update_ctime)
4314{
4315 struct timespec now;
4316
4317 if (update_ctime) {
4318 now = current_fs_time(inode->i_sb);
4319 if (!timespec_equal(&inode->i_ctime, &now))
4320 inode->i_ctime = now;
4321 }
4322 /*
4323 * Update only when preallocation was requested beyond
4324 * the file size.
4325 */
4326 if (!(mode & FALLOC_FL_KEEP_SIZE)) {
4327 if (new_size > i_size_read(inode))
4328 i_size_write(inode, new_size);
4329 if (new_size > EXT4_I(inode)->i_disksize)
4330 ext4_update_i_disksize(inode, new_size);
4331 } else {
4332 /*
4333 * Mark that we allocate beyond EOF so the subsequent truncate
4334 * can proceed even if the new size is the same as i_size.
4335 */
4336 if (new_size > i_size_read(inode))
4337 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4338 }
4339
4340}
4341
4342/*
4343 * preallocate space for a file. This implements ext4's fallocate file
4344 * operation, which gets called from sys_fallocate system call.
4345 * For block-mapped files, posix_fallocate should fall back to the method
4346 * of writing zeroes to the required new blocks (the same behavior which is
4347 * expected for file systems which do not support fallocate() system call).
4348 */
4349long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4350{
4351 struct inode *inode = file->f_path.dentry->d_inode;
4352 handle_t *handle;
4353 loff_t new_size;
4354 unsigned int max_blocks;
4355 int ret = 0;
4356 int ret2 = 0;
4357 int retries = 0;
4358 int flags;
4359 struct ext4_map_blocks map;
4360 unsigned int credits, blkbits = inode->i_blkbits;
4361
4362 /*
4363 * currently supporting (pre)allocate mode for extent-based
4364 * files _only_
4365 */
4366 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4367 return -EOPNOTSUPP;
4368
4369 /* Return error if mode is not supported */
4370 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
4371 return -EOPNOTSUPP;
4372
4373 if (mode & FALLOC_FL_PUNCH_HOLE)
4374 return ext4_punch_hole(file, offset, len);
4375
4376 trace_ext4_fallocate_enter(inode, offset, len, mode);
4377 map.m_lblk = offset >> blkbits;
4378 /*
4379 * We can't just convert len to max_blocks because
4380 * If blocksize = 4096 offset = 3072 and len = 2048
4381 */
4382 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
4383 - map.m_lblk;
4384 /*
4385 * credits to insert 1 extent into extent tree
4386 */
4387 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4388 mutex_lock(&inode->i_mutex);
4389 ret = inode_newsize_ok(inode, (len + offset));
4390 if (ret) {
4391 mutex_unlock(&inode->i_mutex);
4392 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4393 return ret;
4394 }
4395 flags = EXT4_GET_BLOCKS_CREATE_UNINIT_EXT;
4396 if (mode & FALLOC_FL_KEEP_SIZE)
4397 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4398 /*
4399 * Don't normalize the request if it can fit in one extent so
4400 * that it doesn't get unnecessarily split into multiple
4401 * extents.
4402 */
4403 if (len <= EXT_UNINIT_MAX_LEN << blkbits)
4404 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4405retry:
4406 while (ret >= 0 && ret < max_blocks) {
4407 map.m_lblk = map.m_lblk + ret;
4408 map.m_len = max_blocks = max_blocks - ret;
4409 handle = ext4_journal_start(inode, credits);
4410 if (IS_ERR(handle)) {
4411 ret = PTR_ERR(handle);
4412 break;
4413 }
4414 ret = ext4_map_blocks(handle, inode, &map, flags);
4415 if (ret <= 0) {
4416#ifdef EXT4FS_DEBUG
4417 WARN_ON(ret <= 0);
4418 printk(KERN_ERR "%s: ext4_ext_map_blocks "
4419 "returned error inode#%lu, block=%u, "
4420 "max_blocks=%u", __func__,
4421 inode->i_ino, map.m_lblk, max_blocks);
4422#endif
4423 ext4_mark_inode_dirty(handle, inode);
4424 ret2 = ext4_journal_stop(handle);
4425 break;
4426 }
4427 if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
4428 blkbits) >> blkbits))
4429 new_size = offset + len;
4430 else
4431 new_size = ((loff_t) map.m_lblk + ret) << blkbits;
4432
4433 ext4_falloc_update_inode(inode, mode, new_size,
4434 (map.m_flags & EXT4_MAP_NEW));
4435 ext4_mark_inode_dirty(handle, inode);
4436 ret2 = ext4_journal_stop(handle);
4437 if (ret2)
4438 break;
4439 }
4440 if (ret == -ENOSPC &&
4441 ext4_should_retry_alloc(inode->i_sb, &retries)) {
4442 ret = 0;
4443 goto retry;
4444 }
4445 mutex_unlock(&inode->i_mutex);
4446 trace_ext4_fallocate_exit(inode, offset, max_blocks,
4447 ret > 0 ? ret2 : ret);
4448 return ret > 0 ? ret2 : ret;
4449}
4450
4451/*
4452 * This function convert a range of blocks to written extents
4453 * The caller of this function will pass the start offset and the size.
4454 * all unwritten extents within this range will be converted to
4455 * written extents.
4456 *
4457 * This function is called from the direct IO end io call back
4458 * function, to convert the fallocated extents after IO is completed.
4459 * Returns 0 on success.
4460 */
4461int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
4462 ssize_t len)
4463{
4464 handle_t *handle;
4465 unsigned int max_blocks;
4466 int ret = 0;
4467 int ret2 = 0;
4468 struct ext4_map_blocks map;
4469 unsigned int credits, blkbits = inode->i_blkbits;
4470
4471 map.m_lblk = offset >> blkbits;
4472 /*
4473 * We can't just convert len to max_blocks because
4474 * If blocksize = 4096 offset = 3072 and len = 2048
4475 */
4476 max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
4477 map.m_lblk);
4478 /*
4479 * credits to insert 1 extent into extent tree
4480 */
4481 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4482 while (ret >= 0 && ret < max_blocks) {
4483 map.m_lblk += ret;
4484 map.m_len = (max_blocks -= ret);
4485 handle = ext4_journal_start(inode, credits);
4486 if (IS_ERR(handle)) {
4487 ret = PTR_ERR(handle);
4488 break;
4489 }
4490 ret = ext4_map_blocks(handle, inode, &map,
4491 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
4492 if (ret <= 0) {
4493 WARN_ON(ret <= 0);
4494 ext4_msg(inode->i_sb, KERN_ERR,
4495 "%s:%d: inode #%lu: block %u: len %u: "
4496 "ext4_ext_map_blocks returned %d",
4497 __func__, __LINE__, inode->i_ino, map.m_lblk,
4498 map.m_len, ret);
4499 }
4500 ext4_mark_inode_dirty(handle, inode);
4501 ret2 = ext4_journal_stop(handle);
4502 if (ret <= 0 || ret2 )
4503 break;
4504 }
4505 return ret > 0 ? ret2 : ret;
4506}
4507
4508/*
4509 * Callback function called for each extent to gather FIEMAP information.
4510 */
4511static int ext4_ext_fiemap_cb(struct inode *inode, ext4_lblk_t next,
4512 struct ext4_ext_cache *newex, struct ext4_extent *ex,
4513 void *data)
4514{
4515 __u64 logical;
4516 __u64 physical;
4517 __u64 length;
4518 __u32 flags = 0;
4519 int ret = 0;
4520 struct fiemap_extent_info *fieinfo = data;
4521 unsigned char blksize_bits;
4522
4523 blksize_bits = inode->i_sb->s_blocksize_bits;
4524 logical = (__u64)newex->ec_block << blksize_bits;
4525
4526 if (newex->ec_start == 0) {
4527 /*
4528 * No extent in extent-tree contains block @newex->ec_start,
4529 * then the block may stay in 1)a hole or 2)delayed-extent.
4530 *
4531 * Holes or delayed-extents are processed as follows.
4532 * 1. lookup dirty pages with specified range in pagecache.
4533 * If no page is got, then there is no delayed-extent and
4534 * return with EXT_CONTINUE.
4535 * 2. find the 1st mapped buffer,
4536 * 3. check if the mapped buffer is both in the request range
4537 * and a delayed buffer. If not, there is no delayed-extent,
4538 * then return.
4539 * 4. a delayed-extent is found, the extent will be collected.
4540 */
4541 ext4_lblk_t end = 0;
4542 pgoff_t last_offset;
4543 pgoff_t offset;
4544 pgoff_t index;
4545 pgoff_t start_index = 0;
4546 struct page **pages = NULL;
4547 struct buffer_head *bh = NULL;
4548 struct buffer_head *head = NULL;
4549 unsigned int nr_pages = PAGE_SIZE / sizeof(struct page *);
4550
4551 pages = kmalloc(PAGE_SIZE, GFP_KERNEL);
4552 if (pages == NULL)
4553 return -ENOMEM;
4554
4555 offset = logical >> PAGE_SHIFT;
4556repeat:
4557 last_offset = offset;
4558 head = NULL;
4559 ret = find_get_pages_tag(inode->i_mapping, &offset,
4560 PAGECACHE_TAG_DIRTY, nr_pages, pages);
4561
4562 if (!(flags & FIEMAP_EXTENT_DELALLOC)) {
4563 /* First time, try to find a mapped buffer. */
4564 if (ret == 0) {
4565out:
4566 for (index = 0; index < ret; index++)
4567 page_cache_release(pages[index]);
4568 /* just a hole. */
4569 kfree(pages);
4570 return EXT_CONTINUE;
4571 }
4572 index = 0;
4573
4574next_page:
4575 /* Try to find the 1st mapped buffer. */
4576 end = ((__u64)pages[index]->index << PAGE_SHIFT) >>
4577 blksize_bits;
4578 if (!page_has_buffers(pages[index]))
4579 goto out;
4580 head = page_buffers(pages[index]);
4581 if (!head)
4582 goto out;
4583
4584 index++;
4585 bh = head;
4586 do {
4587 if (end >= newex->ec_block +
4588 newex->ec_len)
4589 /* The buffer is out of
4590 * the request range.
4591 */
4592 goto out;
4593
4594 if (buffer_mapped(bh) &&
4595 end >= newex->ec_block) {
4596 start_index = index - 1;
4597 /* get the 1st mapped buffer. */
4598 goto found_mapped_buffer;
4599 }
4600
4601 bh = bh->b_this_page;
4602 end++;
4603 } while (bh != head);
4604
4605 /* No mapped buffer in the range found in this page,
4606 * We need to look up next page.
4607 */
4608 if (index >= ret) {
4609 /* There is no page left, but we need to limit
4610 * newex->ec_len.
4611 */
4612 newex->ec_len = end - newex->ec_block;
4613 goto out;
4614 }
4615 goto next_page;
4616 } else {
4617 /*Find contiguous delayed buffers. */
4618 if (ret > 0 && pages[0]->index == last_offset)
4619 head = page_buffers(pages[0]);
4620 bh = head;
4621 index = 1;
4622 start_index = 0;
4623 }
4624
4625found_mapped_buffer:
4626 if (bh != NULL && buffer_delay(bh)) {
4627 /* 1st or contiguous delayed buffer found. */
4628 if (!(flags & FIEMAP_EXTENT_DELALLOC)) {
4629 /*
4630 * 1st delayed buffer found, record
4631 * the start of extent.
4632 */
4633 flags |= FIEMAP_EXTENT_DELALLOC;
4634 newex->ec_block = end;
4635 logical = (__u64)end << blksize_bits;
4636 }
4637 /* Find contiguous delayed buffers. */
4638 do {
4639 if (!buffer_delay(bh))
4640 goto found_delayed_extent;
4641 bh = bh->b_this_page;
4642 end++;
4643 } while (bh != head);
4644
4645 for (; index < ret; index++) {
4646 if (!page_has_buffers(pages[index])) {
4647 bh = NULL;
4648 break;
4649 }
4650 head = page_buffers(pages[index]);
4651 if (!head) {
4652 bh = NULL;
4653 break;
4654 }
4655
4656 if (pages[index]->index !=
4657 pages[start_index]->index + index
4658 - start_index) {
4659 /* Blocks are not contiguous. */
4660 bh = NULL;
4661 break;
4662 }
4663 bh = head;
4664 do {
4665 if (!buffer_delay(bh))
4666 /* Delayed-extent ends. */
4667 goto found_delayed_extent;
4668 bh = bh->b_this_page;
4669 end++;
4670 } while (bh != head);
4671 }
4672 } else if (!(flags & FIEMAP_EXTENT_DELALLOC))
4673 /* a hole found. */
4674 goto out;
4675
4676found_delayed_extent:
4677 newex->ec_len = min(end - newex->ec_block,
4678 (ext4_lblk_t)EXT_INIT_MAX_LEN);
4679 if (ret == nr_pages && bh != NULL &&
4680 newex->ec_len < EXT_INIT_MAX_LEN &&
4681 buffer_delay(bh)) {
4682 /* Have not collected an extent and continue. */
4683 for (index = 0; index < ret; index++)
4684 page_cache_release(pages[index]);
4685 goto repeat;
4686 }
4687
4688 for (index = 0; index < ret; index++)
4689 page_cache_release(pages[index]);
4690 kfree(pages);
4691 }
4692
4693 physical = (__u64)newex->ec_start << blksize_bits;
4694 length = (__u64)newex->ec_len << blksize_bits;
4695
4696 if (ex && ext4_ext_is_uninitialized(ex))
4697 flags |= FIEMAP_EXTENT_UNWRITTEN;
4698
4699 if (next == EXT_MAX_BLOCKS)
4700 flags |= FIEMAP_EXTENT_LAST;
4701
4702 ret = fiemap_fill_next_extent(fieinfo, logical, physical,
4703 length, flags);
4704 if (ret < 0)
4705 return ret;
4706 if (ret == 1)
4707 return EXT_BREAK;
4708 return EXT_CONTINUE;
4709}
4710/* fiemap flags we can handle specified here */
4711#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
4712
4713static int ext4_xattr_fiemap(struct inode *inode,
4714 struct fiemap_extent_info *fieinfo)
4715{
4716 __u64 physical = 0;
4717 __u64 length;
4718 __u32 flags = FIEMAP_EXTENT_LAST;
4719 int blockbits = inode->i_sb->s_blocksize_bits;
4720 int error = 0;
4721
4722 /* in-inode? */
4723 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
4724 struct ext4_iloc iloc;
4725 int offset; /* offset of xattr in inode */
4726
4727 error = ext4_get_inode_loc(inode, &iloc);
4728 if (error)
4729 return error;
4730 physical = iloc.bh->b_blocknr << blockbits;
4731 offset = EXT4_GOOD_OLD_INODE_SIZE +
4732 EXT4_I(inode)->i_extra_isize;
4733 physical += offset;
4734 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
4735 flags |= FIEMAP_EXTENT_DATA_INLINE;
4736 brelse(iloc.bh);
4737 } else { /* external block */
4738 physical = EXT4_I(inode)->i_file_acl << blockbits;
4739 length = inode->i_sb->s_blocksize;
4740 }
4741
4742 if (physical)
4743 error = fiemap_fill_next_extent(fieinfo, 0, physical,
4744 length, flags);
4745 return (error < 0 ? error : 0);
4746}
4747
4748/*
4749 * ext4_ext_punch_hole
4750 *
4751 * Punches a hole of "length" bytes in a file starting
4752 * at byte "offset"
4753 *
4754 * @inode: The inode of the file to punch a hole in
4755 * @offset: The starting byte offset of the hole
4756 * @length: The length of the hole
4757 *
4758 * Returns the number of blocks removed or negative on err
4759 */
4760int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
4761{
4762 struct inode *inode = file->f_path.dentry->d_inode;
4763 struct super_block *sb = inode->i_sb;
4764 ext4_lblk_t first_block, stop_block;
4765 struct address_space *mapping = inode->i_mapping;
4766 handle_t *handle;
4767 loff_t first_page, last_page, page_len;
4768 loff_t first_page_offset, last_page_offset;
4769 int credits, err = 0;
4770
4771 /* No need to punch hole beyond i_size */
4772 if (offset >= inode->i_size)
4773 return 0;
4774
4775 /*
4776 * If the hole extends beyond i_size, set the hole
4777 * to end after the page that contains i_size
4778 */
4779 if (offset + length > inode->i_size) {
4780 length = inode->i_size +
4781 PAGE_CACHE_SIZE - (inode->i_size & (PAGE_CACHE_SIZE - 1)) -
4782 offset;
4783 }
4784
4785 first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
4786 last_page = (offset + length) >> PAGE_CACHE_SHIFT;
4787
4788 first_page_offset = first_page << PAGE_CACHE_SHIFT;
4789 last_page_offset = last_page << PAGE_CACHE_SHIFT;
4790
4791 /*
4792 * Write out all dirty pages to avoid race conditions
4793 * Then release them.
4794 */
4795 if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
4796 err = filemap_write_and_wait_range(mapping,
4797 offset, offset + length - 1);
4798
4799 if (err)
4800 return err;
4801 }
4802
4803 /* Now release the pages */
4804 if (last_page_offset > first_page_offset) {
4805 truncate_pagecache_range(inode, first_page_offset,
4806 last_page_offset - 1);
4807 }
4808
4809 /* finish any pending end_io work */
4810 ext4_flush_completed_IO(inode);
4811
4812 credits = ext4_writepage_trans_blocks(inode);
4813 handle = ext4_journal_start(inode, credits);
4814 if (IS_ERR(handle))
4815 return PTR_ERR(handle);
4816
4817 err = ext4_orphan_add(handle, inode);
4818 if (err)
4819 goto out;
4820
4821 /*
4822 * Now we need to zero out the non-page-aligned data in the
4823 * pages at the start and tail of the hole, and unmap the buffer
4824 * heads for the block aligned regions of the page that were
4825 * completely zeroed.
4826 */
4827 if (first_page > last_page) {
4828 /*
4829 * If the file space being truncated is contained within a page
4830 * just zero out and unmap the middle of that page
4831 */
4832 err = ext4_discard_partial_page_buffers(handle,
4833 mapping, offset, length, 0);
4834
4835 if (err)
4836 goto out;
4837 } else {
4838 /*
4839 * zero out and unmap the partial page that contains
4840 * the start of the hole
4841 */
4842 page_len = first_page_offset - offset;
4843 if (page_len > 0) {
4844 err = ext4_discard_partial_page_buffers(handle, mapping,
4845 offset, page_len, 0);
4846 if (err)
4847 goto out;
4848 }
4849
4850 /*
4851 * zero out and unmap the partial page that contains
4852 * the end of the hole
4853 */
4854 page_len = offset + length - last_page_offset;
4855 if (page_len > 0) {
4856 err = ext4_discard_partial_page_buffers(handle, mapping,
4857 last_page_offset, page_len, 0);
4858 if (err)
4859 goto out;
4860 }
4861 }
4862
4863 /*
4864 * If i_size is contained in the last page, we need to
4865 * unmap and zero the partial page after i_size
4866 */
4867 if (inode->i_size >> PAGE_CACHE_SHIFT == last_page &&
4868 inode->i_size % PAGE_CACHE_SIZE != 0) {
4869
4870 page_len = PAGE_CACHE_SIZE -
4871 (inode->i_size & (PAGE_CACHE_SIZE - 1));
4872
4873 if (page_len > 0) {
4874 err = ext4_discard_partial_page_buffers(handle,
4875 mapping, inode->i_size, page_len, 0);
4876
4877 if (err)
4878 goto out;
4879 }
4880 }
4881
4882 first_block = (offset + sb->s_blocksize - 1) >>
4883 EXT4_BLOCK_SIZE_BITS(sb);
4884 stop_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
4885
4886 /* If there are no blocks to remove, return now */
4887 if (first_block >= stop_block)
4888 goto out;
4889
4890 down_write(&EXT4_I(inode)->i_data_sem);
4891 ext4_ext_invalidate_cache(inode);
4892 ext4_discard_preallocations(inode);
4893
4894 err = ext4_ext_remove_space(inode, first_block, stop_block - 1);
4895
4896 ext4_ext_invalidate_cache(inode);
4897 ext4_discard_preallocations(inode);
4898
4899 if (IS_SYNC(inode))
4900 ext4_handle_sync(handle);
4901
4902 up_write(&EXT4_I(inode)->i_data_sem);
4903
4904out:
4905 ext4_orphan_del(handle, inode);
4906 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4907 ext4_mark_inode_dirty(handle, inode);
4908 ext4_journal_stop(handle);
4909 return err;
4910}
4911int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4912 __u64 start, __u64 len)
4913{
4914 ext4_lblk_t start_blk;
4915 int error = 0;
4916
4917 /* fallback to generic here if not in extents fmt */
4918 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4919 return generic_block_fiemap(inode, fieinfo, start, len,
4920 ext4_get_block);
4921
4922 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
4923 return -EBADR;
4924
4925 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
4926 error = ext4_xattr_fiemap(inode, fieinfo);
4927 } else {
4928 ext4_lblk_t len_blks;
4929 __u64 last_blk;
4930
4931 start_blk = start >> inode->i_sb->s_blocksize_bits;
4932 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
4933 if (last_blk >= EXT_MAX_BLOCKS)
4934 last_blk = EXT_MAX_BLOCKS-1;
4935 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
4936
4937 /*
4938 * Walk the extent tree gathering extent information.
4939 * ext4_ext_fiemap_cb will push extents back to user.
4940 */
4941 error = ext4_ext_walk_space(inode, start_blk, len_blks,
4942 ext4_ext_fiemap_cb, fieinfo);
4943 }
4944
4945 return error;
4946}