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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 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}
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
4 * Written by Alex Tomas <alex@clusterfs.com>
5 *
6 * Architecture independence:
7 * Copyright (c) 2005, Bull S.A.
8 * Written by Pierre Peiffer <pierre.peiffer@bull.net>
9 */
10
11/*
12 * Extents support for EXT4
13 *
14 * TODO:
15 * - ext4*_error() should be used in some situations
16 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
17 * - smart tree reduction
18 */
19
20#include <linux/fs.h>
21#include <linux/time.h>
22#include <linux/jbd2.h>
23#include <linux/highuid.h>
24#include <linux/pagemap.h>
25#include <linux/quotaops.h>
26#include <linux/string.h>
27#include <linux/slab.h>
28#include <linux/uaccess.h>
29#include <linux/fiemap.h>
30#include <linux/iomap.h>
31#include <linux/sched/mm.h>
32#include "ext4_jbd2.h"
33#include "ext4_extents.h"
34#include "xattr.h"
35
36#include <trace/events/ext4.h>
37
38/*
39 * used by extent splitting.
40 */
41#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
42 due to ENOSPC */
43#define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */
44#define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */
45
46#define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
47#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
48
49static __le32 ext4_extent_block_csum(struct inode *inode,
50 struct ext4_extent_header *eh)
51{
52 struct ext4_inode_info *ei = EXT4_I(inode);
53 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
54 __u32 csum;
55
56 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
57 EXT4_EXTENT_TAIL_OFFSET(eh));
58 return cpu_to_le32(csum);
59}
60
61static int ext4_extent_block_csum_verify(struct inode *inode,
62 struct ext4_extent_header *eh)
63{
64 struct ext4_extent_tail *et;
65
66 if (!ext4_has_metadata_csum(inode->i_sb))
67 return 1;
68
69 et = find_ext4_extent_tail(eh);
70 if (et->et_checksum != ext4_extent_block_csum(inode, eh))
71 return 0;
72 return 1;
73}
74
75static void ext4_extent_block_csum_set(struct inode *inode,
76 struct ext4_extent_header *eh)
77{
78 struct ext4_extent_tail *et;
79
80 if (!ext4_has_metadata_csum(inode->i_sb))
81 return;
82
83 et = find_ext4_extent_tail(eh);
84 et->et_checksum = ext4_extent_block_csum(inode, eh);
85}
86
87static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
88 struct inode *inode,
89 struct ext4_ext_path *path,
90 ext4_lblk_t split,
91 int split_flag, int flags);
92
93static int ext4_ext_trunc_restart_fn(struct inode *inode, int *dropped)
94{
95 /*
96 * Drop i_data_sem to avoid deadlock with ext4_map_blocks. At this
97 * moment, get_block can be called only for blocks inside i_size since
98 * page cache has been already dropped and writes are blocked by
99 * i_rwsem. So we can safely drop the i_data_sem here.
100 */
101 BUG_ON(EXT4_JOURNAL(inode) == NULL);
102 ext4_discard_preallocations(inode);
103 up_write(&EXT4_I(inode)->i_data_sem);
104 *dropped = 1;
105 return 0;
106}
107
108static inline void ext4_ext_path_brelse(struct ext4_ext_path *path)
109{
110 brelse(path->p_bh);
111 path->p_bh = NULL;
112}
113
114static void ext4_ext_drop_refs(struct ext4_ext_path *path)
115{
116 int depth, i;
117
118 if (IS_ERR_OR_NULL(path))
119 return;
120 depth = path->p_depth;
121 for (i = 0; i <= depth; i++, path++)
122 ext4_ext_path_brelse(path);
123}
124
125void ext4_free_ext_path(struct ext4_ext_path *path)
126{
127 if (IS_ERR_OR_NULL(path))
128 return;
129 ext4_ext_drop_refs(path);
130 kfree(path);
131}
132
133/*
134 * Make sure 'handle' has at least 'check_cred' credits. If not, restart
135 * transaction with 'restart_cred' credits. The function drops i_data_sem
136 * when restarting transaction and gets it after transaction is restarted.
137 *
138 * The function returns 0 on success, 1 if transaction had to be restarted,
139 * and < 0 in case of fatal error.
140 */
141int ext4_datasem_ensure_credits(handle_t *handle, struct inode *inode,
142 int check_cred, int restart_cred,
143 int revoke_cred)
144{
145 int ret;
146 int dropped = 0;
147
148 ret = ext4_journal_ensure_credits_fn(handle, check_cred, restart_cred,
149 revoke_cred, ext4_ext_trunc_restart_fn(inode, &dropped));
150 if (dropped)
151 down_write(&EXT4_I(inode)->i_data_sem);
152 return ret;
153}
154
155/*
156 * could return:
157 * - EROFS
158 * - ENOMEM
159 */
160static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
161 struct ext4_ext_path *path)
162{
163 int err = 0;
164
165 if (path->p_bh) {
166 /* path points to block */
167 BUFFER_TRACE(path->p_bh, "get_write_access");
168 err = ext4_journal_get_write_access(handle, inode->i_sb,
169 path->p_bh, EXT4_JTR_NONE);
170 /*
171 * The extent buffer's verified bit will be set again in
172 * __ext4_ext_dirty(). We could leave an inconsistent
173 * buffer if the extents updating procudure break off du
174 * to some error happens, force to check it again.
175 */
176 if (!err)
177 clear_buffer_verified(path->p_bh);
178 }
179 /* path points to leaf/index in inode body */
180 /* we use in-core data, no need to protect them */
181 return err;
182}
183
184/*
185 * could return:
186 * - EROFS
187 * - ENOMEM
188 * - EIO
189 */
190static int __ext4_ext_dirty(const char *where, unsigned int line,
191 handle_t *handle, struct inode *inode,
192 struct ext4_ext_path *path)
193{
194 int err;
195
196 WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
197 if (path->p_bh) {
198 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
199 /* path points to block */
200 err = __ext4_handle_dirty_metadata(where, line, handle,
201 inode, path->p_bh);
202 /* Extents updating done, re-set verified flag */
203 if (!err)
204 set_buffer_verified(path->p_bh);
205 } else {
206 /* path points to leaf/index in inode body */
207 err = ext4_mark_inode_dirty(handle, inode);
208 }
209 return err;
210}
211
212#define ext4_ext_dirty(handle, inode, path) \
213 __ext4_ext_dirty(__func__, __LINE__, (handle), (inode), (path))
214
215static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
216 struct ext4_ext_path *path,
217 ext4_lblk_t block)
218{
219 if (path) {
220 int depth = path->p_depth;
221 struct ext4_extent *ex;
222
223 /*
224 * Try to predict block placement assuming that we are
225 * filling in a file which will eventually be
226 * non-sparse --- i.e., in the case of libbfd writing
227 * an ELF object sections out-of-order but in a way
228 * the eventually results in a contiguous object or
229 * executable file, or some database extending a table
230 * space file. However, this is actually somewhat
231 * non-ideal if we are writing a sparse file such as
232 * qemu or KVM writing a raw image file that is going
233 * to stay fairly sparse, since it will end up
234 * fragmenting the file system's free space. Maybe we
235 * should have some hueristics or some way to allow
236 * userspace to pass a hint to file system,
237 * especially if the latter case turns out to be
238 * common.
239 */
240 ex = path[depth].p_ext;
241 if (ex) {
242 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
243 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
244
245 if (block > ext_block)
246 return ext_pblk + (block - ext_block);
247 else
248 return ext_pblk - (ext_block - block);
249 }
250
251 /* it looks like index is empty;
252 * try to find starting block from index itself */
253 if (path[depth].p_bh)
254 return path[depth].p_bh->b_blocknr;
255 }
256
257 /* OK. use inode's group */
258 return ext4_inode_to_goal_block(inode);
259}
260
261/*
262 * Allocation for a meta data block
263 */
264static ext4_fsblk_t
265ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
266 struct ext4_ext_path *path,
267 struct ext4_extent *ex, int *err, unsigned int flags)
268{
269 ext4_fsblk_t goal, newblock;
270
271 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
272 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
273 NULL, err);
274 return newblock;
275}
276
277static inline int ext4_ext_space_block(struct inode *inode, int check)
278{
279 int size;
280
281 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
282 / sizeof(struct ext4_extent);
283#ifdef AGGRESSIVE_TEST
284 if (!check && size > 6)
285 size = 6;
286#endif
287 return size;
288}
289
290static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
291{
292 int size;
293
294 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
295 / sizeof(struct ext4_extent_idx);
296#ifdef AGGRESSIVE_TEST
297 if (!check && size > 5)
298 size = 5;
299#endif
300 return size;
301}
302
303static inline int ext4_ext_space_root(struct inode *inode, int check)
304{
305 int size;
306
307 size = sizeof(EXT4_I(inode)->i_data);
308 size -= sizeof(struct ext4_extent_header);
309 size /= sizeof(struct ext4_extent);
310#ifdef AGGRESSIVE_TEST
311 if (!check && size > 3)
312 size = 3;
313#endif
314 return size;
315}
316
317static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
318{
319 int size;
320
321 size = sizeof(EXT4_I(inode)->i_data);
322 size -= sizeof(struct ext4_extent_header);
323 size /= sizeof(struct ext4_extent_idx);
324#ifdef AGGRESSIVE_TEST
325 if (!check && size > 4)
326 size = 4;
327#endif
328 return size;
329}
330
331static inline struct ext4_ext_path *
332ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
333 struct ext4_ext_path *path, ext4_lblk_t lblk,
334 int nofail)
335{
336 int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
337 int flags = EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO;
338
339 if (nofail)
340 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL | EXT4_EX_NOFAIL;
341
342 return ext4_split_extent_at(handle, inode, path, lblk, unwritten ?
343 EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
344 flags);
345}
346
347static int
348ext4_ext_max_entries(struct inode *inode, int depth)
349{
350 int max;
351
352 if (depth == ext_depth(inode)) {
353 if (depth == 0)
354 max = ext4_ext_space_root(inode, 1);
355 else
356 max = ext4_ext_space_root_idx(inode, 1);
357 } else {
358 if (depth == 0)
359 max = ext4_ext_space_block(inode, 1);
360 else
361 max = ext4_ext_space_block_idx(inode, 1);
362 }
363
364 return max;
365}
366
367static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
368{
369 ext4_fsblk_t block = ext4_ext_pblock(ext);
370 int len = ext4_ext_get_actual_len(ext);
371 ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
372
373 /*
374 * We allow neither:
375 * - zero length
376 * - overflow/wrap-around
377 */
378 if (lblock + len <= lblock)
379 return 0;
380 return ext4_inode_block_valid(inode, block, len);
381}
382
383static int ext4_valid_extent_idx(struct inode *inode,
384 struct ext4_extent_idx *ext_idx)
385{
386 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
387
388 return ext4_inode_block_valid(inode, block, 1);
389}
390
391static int ext4_valid_extent_entries(struct inode *inode,
392 struct ext4_extent_header *eh,
393 ext4_lblk_t lblk, ext4_fsblk_t *pblk,
394 int depth)
395{
396 unsigned short entries;
397 ext4_lblk_t lblock = 0;
398 ext4_lblk_t cur = 0;
399
400 if (eh->eh_entries == 0)
401 return 1;
402
403 entries = le16_to_cpu(eh->eh_entries);
404
405 if (depth == 0) {
406 /* leaf entries */
407 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
408
409 /*
410 * The logical block in the first entry should equal to
411 * the number in the index block.
412 */
413 if (depth != ext_depth(inode) &&
414 lblk != le32_to_cpu(ext->ee_block))
415 return 0;
416 while (entries) {
417 if (!ext4_valid_extent(inode, ext))
418 return 0;
419
420 /* Check for overlapping extents */
421 lblock = le32_to_cpu(ext->ee_block);
422 if (lblock < cur) {
423 *pblk = ext4_ext_pblock(ext);
424 return 0;
425 }
426 cur = lblock + ext4_ext_get_actual_len(ext);
427 ext++;
428 entries--;
429 }
430 } else {
431 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
432
433 /*
434 * The logical block in the first entry should equal to
435 * the number in the parent index block.
436 */
437 if (depth != ext_depth(inode) &&
438 lblk != le32_to_cpu(ext_idx->ei_block))
439 return 0;
440 while (entries) {
441 if (!ext4_valid_extent_idx(inode, ext_idx))
442 return 0;
443
444 /* Check for overlapping index extents */
445 lblock = le32_to_cpu(ext_idx->ei_block);
446 if (lblock < cur) {
447 *pblk = ext4_idx_pblock(ext_idx);
448 return 0;
449 }
450 ext_idx++;
451 entries--;
452 cur = lblock + 1;
453 }
454 }
455 return 1;
456}
457
458static int __ext4_ext_check(const char *function, unsigned int line,
459 struct inode *inode, struct ext4_extent_header *eh,
460 int depth, ext4_fsblk_t pblk, ext4_lblk_t lblk)
461{
462 const char *error_msg;
463 int max = 0, err = -EFSCORRUPTED;
464
465 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
466 error_msg = "invalid magic";
467 goto corrupted;
468 }
469 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
470 error_msg = "unexpected eh_depth";
471 goto corrupted;
472 }
473 if (unlikely(eh->eh_max == 0)) {
474 error_msg = "invalid eh_max";
475 goto corrupted;
476 }
477 max = ext4_ext_max_entries(inode, depth);
478 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
479 error_msg = "too large eh_max";
480 goto corrupted;
481 }
482 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
483 error_msg = "invalid eh_entries";
484 goto corrupted;
485 }
486 if (unlikely((eh->eh_entries == 0) && (depth > 0))) {
487 error_msg = "eh_entries is 0 but eh_depth is > 0";
488 goto corrupted;
489 }
490 if (!ext4_valid_extent_entries(inode, eh, lblk, &pblk, depth)) {
491 error_msg = "invalid extent entries";
492 goto corrupted;
493 }
494 if (unlikely(depth > 32)) {
495 error_msg = "too large eh_depth";
496 goto corrupted;
497 }
498 /* Verify checksum on non-root extent tree nodes */
499 if (ext_depth(inode) != depth &&
500 !ext4_extent_block_csum_verify(inode, eh)) {
501 error_msg = "extent tree corrupted";
502 err = -EFSBADCRC;
503 goto corrupted;
504 }
505 return 0;
506
507corrupted:
508 ext4_error_inode_err(inode, function, line, 0, -err,
509 "pblk %llu bad header/extent: %s - magic %x, "
510 "entries %u, max %u(%u), depth %u(%u)",
511 (unsigned long long) pblk, error_msg,
512 le16_to_cpu(eh->eh_magic),
513 le16_to_cpu(eh->eh_entries),
514 le16_to_cpu(eh->eh_max),
515 max, le16_to_cpu(eh->eh_depth), depth);
516 return err;
517}
518
519#define ext4_ext_check(inode, eh, depth, pblk) \
520 __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk), 0)
521
522int ext4_ext_check_inode(struct inode *inode)
523{
524 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
525}
526
527static void ext4_cache_extents(struct inode *inode,
528 struct ext4_extent_header *eh)
529{
530 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
531 ext4_lblk_t prev = 0;
532 int i;
533
534 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
535 unsigned int status = EXTENT_STATUS_WRITTEN;
536 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
537 int len = ext4_ext_get_actual_len(ex);
538
539 if (prev && (prev != lblk))
540 ext4_es_cache_extent(inode, prev, lblk - prev, ~0,
541 EXTENT_STATUS_HOLE);
542
543 if (ext4_ext_is_unwritten(ex))
544 status = EXTENT_STATUS_UNWRITTEN;
545 ext4_es_cache_extent(inode, lblk, len,
546 ext4_ext_pblock(ex), status);
547 prev = lblk + len;
548 }
549}
550
551static struct buffer_head *
552__read_extent_tree_block(const char *function, unsigned int line,
553 struct inode *inode, struct ext4_extent_idx *idx,
554 int depth, int flags)
555{
556 struct buffer_head *bh;
557 int err;
558 gfp_t gfp_flags = __GFP_MOVABLE | GFP_NOFS;
559 ext4_fsblk_t pblk;
560
561 if (flags & EXT4_EX_NOFAIL)
562 gfp_flags |= __GFP_NOFAIL;
563
564 pblk = ext4_idx_pblock(idx);
565 bh = sb_getblk_gfp(inode->i_sb, pblk, gfp_flags);
566 if (unlikely(!bh))
567 return ERR_PTR(-ENOMEM);
568
569 if (!bh_uptodate_or_lock(bh)) {
570 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
571 err = ext4_read_bh(bh, 0, NULL, false);
572 if (err < 0)
573 goto errout;
574 }
575 if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
576 return bh;
577 err = __ext4_ext_check(function, line, inode, ext_block_hdr(bh),
578 depth, pblk, le32_to_cpu(idx->ei_block));
579 if (err)
580 goto errout;
581 set_buffer_verified(bh);
582 /*
583 * If this is a leaf block, cache all of its entries
584 */
585 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
586 struct ext4_extent_header *eh = ext_block_hdr(bh);
587 ext4_cache_extents(inode, eh);
588 }
589 return bh;
590errout:
591 put_bh(bh);
592 return ERR_PTR(err);
593
594}
595
596#define read_extent_tree_block(inode, idx, depth, flags) \
597 __read_extent_tree_block(__func__, __LINE__, (inode), (idx), \
598 (depth), (flags))
599
600/*
601 * This function is called to cache a file's extent information in the
602 * extent status tree
603 */
604int ext4_ext_precache(struct inode *inode)
605{
606 struct ext4_inode_info *ei = EXT4_I(inode);
607 struct ext4_ext_path *path = NULL;
608 struct buffer_head *bh;
609 int i = 0, depth, ret = 0;
610
611 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
612 return 0; /* not an extent-mapped inode */
613
614 down_read(&ei->i_data_sem);
615 depth = ext_depth(inode);
616
617 /* Don't cache anything if there are no external extent blocks */
618 if (!depth) {
619 up_read(&ei->i_data_sem);
620 return ret;
621 }
622
623 path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
624 GFP_NOFS);
625 if (path == NULL) {
626 up_read(&ei->i_data_sem);
627 return -ENOMEM;
628 }
629
630 path[0].p_hdr = ext_inode_hdr(inode);
631 ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
632 if (ret)
633 goto out;
634 path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
635 while (i >= 0) {
636 /*
637 * If this is a leaf block or we've reached the end of
638 * the index block, go up
639 */
640 if ((i == depth) ||
641 path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
642 ext4_ext_path_brelse(path + i);
643 i--;
644 continue;
645 }
646 bh = read_extent_tree_block(inode, path[i].p_idx++,
647 depth - i - 1,
648 EXT4_EX_FORCE_CACHE);
649 if (IS_ERR(bh)) {
650 ret = PTR_ERR(bh);
651 break;
652 }
653 i++;
654 path[i].p_bh = bh;
655 path[i].p_hdr = ext_block_hdr(bh);
656 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
657 }
658 ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
659out:
660 up_read(&ei->i_data_sem);
661 ext4_free_ext_path(path);
662 return ret;
663}
664
665#ifdef EXT_DEBUG
666static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
667{
668 int k, l = path->p_depth;
669
670 ext_debug(inode, "path:");
671 for (k = 0; k <= l; k++, path++) {
672 if (path->p_idx) {
673 ext_debug(inode, " %d->%llu",
674 le32_to_cpu(path->p_idx->ei_block),
675 ext4_idx_pblock(path->p_idx));
676 } else if (path->p_ext) {
677 ext_debug(inode, " %d:[%d]%d:%llu ",
678 le32_to_cpu(path->p_ext->ee_block),
679 ext4_ext_is_unwritten(path->p_ext),
680 ext4_ext_get_actual_len(path->p_ext),
681 ext4_ext_pblock(path->p_ext));
682 } else
683 ext_debug(inode, " []");
684 }
685 ext_debug(inode, "\n");
686}
687
688static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
689{
690 int depth = ext_depth(inode);
691 struct ext4_extent_header *eh;
692 struct ext4_extent *ex;
693 int i;
694
695 if (IS_ERR_OR_NULL(path))
696 return;
697
698 eh = path[depth].p_hdr;
699 ex = EXT_FIRST_EXTENT(eh);
700
701 ext_debug(inode, "Displaying leaf extents\n");
702
703 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
704 ext_debug(inode, "%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
705 ext4_ext_is_unwritten(ex),
706 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
707 }
708 ext_debug(inode, "\n");
709}
710
711static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
712 ext4_fsblk_t newblock, int level)
713{
714 int depth = ext_depth(inode);
715 struct ext4_extent *ex;
716
717 if (depth != level) {
718 struct ext4_extent_idx *idx;
719 idx = path[level].p_idx;
720 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
721 ext_debug(inode, "%d: move %d:%llu in new index %llu\n",
722 level, le32_to_cpu(idx->ei_block),
723 ext4_idx_pblock(idx), newblock);
724 idx++;
725 }
726
727 return;
728 }
729
730 ex = path[depth].p_ext;
731 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
732 ext_debug(inode, "move %d:%llu:[%d]%d in new leaf %llu\n",
733 le32_to_cpu(ex->ee_block),
734 ext4_ext_pblock(ex),
735 ext4_ext_is_unwritten(ex),
736 ext4_ext_get_actual_len(ex),
737 newblock);
738 ex++;
739 }
740}
741
742#else
743#define ext4_ext_show_path(inode, path)
744#define ext4_ext_show_leaf(inode, path)
745#define ext4_ext_show_move(inode, path, newblock, level)
746#endif
747
748/*
749 * ext4_ext_binsearch_idx:
750 * binary search for the closest index of the given block
751 * the header must be checked before calling this
752 */
753static void
754ext4_ext_binsearch_idx(struct inode *inode,
755 struct ext4_ext_path *path, ext4_lblk_t block)
756{
757 struct ext4_extent_header *eh = path->p_hdr;
758 struct ext4_extent_idx *r, *l, *m;
759
760
761 ext_debug(inode, "binsearch for %u(idx): ", block);
762
763 l = EXT_FIRST_INDEX(eh) + 1;
764 r = EXT_LAST_INDEX(eh);
765 while (l <= r) {
766 m = l + (r - l) / 2;
767 ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l,
768 le32_to_cpu(l->ei_block), m, le32_to_cpu(m->ei_block),
769 r, le32_to_cpu(r->ei_block));
770
771 if (block < le32_to_cpu(m->ei_block))
772 r = m - 1;
773 else
774 l = m + 1;
775 }
776
777 path->p_idx = l - 1;
778 ext_debug(inode, " -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
779 ext4_idx_pblock(path->p_idx));
780
781#ifdef CHECK_BINSEARCH
782 {
783 struct ext4_extent_idx *chix, *ix;
784 int k;
785
786 chix = ix = EXT_FIRST_INDEX(eh);
787 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
788 if (k != 0 && le32_to_cpu(ix->ei_block) <=
789 le32_to_cpu(ix[-1].ei_block)) {
790 printk(KERN_DEBUG "k=%d, ix=0x%p, "
791 "first=0x%p\n", k,
792 ix, EXT_FIRST_INDEX(eh));
793 printk(KERN_DEBUG "%u <= %u\n",
794 le32_to_cpu(ix->ei_block),
795 le32_to_cpu(ix[-1].ei_block));
796 }
797 BUG_ON(k && le32_to_cpu(ix->ei_block)
798 <= le32_to_cpu(ix[-1].ei_block));
799 if (block < le32_to_cpu(ix->ei_block))
800 break;
801 chix = ix;
802 }
803 BUG_ON(chix != path->p_idx);
804 }
805#endif
806
807}
808
809/*
810 * ext4_ext_binsearch:
811 * binary search for closest extent of the given block
812 * the header must be checked before calling this
813 */
814static void
815ext4_ext_binsearch(struct inode *inode,
816 struct ext4_ext_path *path, ext4_lblk_t block)
817{
818 struct ext4_extent_header *eh = path->p_hdr;
819 struct ext4_extent *r, *l, *m;
820
821 if (eh->eh_entries == 0) {
822 /*
823 * this leaf is empty:
824 * we get such a leaf in split/add case
825 */
826 return;
827 }
828
829 ext_debug(inode, "binsearch for %u: ", block);
830
831 l = EXT_FIRST_EXTENT(eh) + 1;
832 r = EXT_LAST_EXTENT(eh);
833
834 while (l <= r) {
835 m = l + (r - l) / 2;
836 ext_debug(inode, "%p(%u):%p(%u):%p(%u) ", l,
837 le32_to_cpu(l->ee_block), m, le32_to_cpu(m->ee_block),
838 r, le32_to_cpu(r->ee_block));
839
840 if (block < le32_to_cpu(m->ee_block))
841 r = m - 1;
842 else
843 l = m + 1;
844 }
845
846 path->p_ext = l - 1;
847 ext_debug(inode, " -> %d:%llu:[%d]%d ",
848 le32_to_cpu(path->p_ext->ee_block),
849 ext4_ext_pblock(path->p_ext),
850 ext4_ext_is_unwritten(path->p_ext),
851 ext4_ext_get_actual_len(path->p_ext));
852
853#ifdef CHECK_BINSEARCH
854 {
855 struct ext4_extent *chex, *ex;
856 int k;
857
858 chex = ex = EXT_FIRST_EXTENT(eh);
859 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
860 BUG_ON(k && le32_to_cpu(ex->ee_block)
861 <= le32_to_cpu(ex[-1].ee_block));
862 if (block < le32_to_cpu(ex->ee_block))
863 break;
864 chex = ex;
865 }
866 BUG_ON(chex != path->p_ext);
867 }
868#endif
869
870}
871
872void ext4_ext_tree_init(handle_t *handle, struct inode *inode)
873{
874 struct ext4_extent_header *eh;
875
876 eh = ext_inode_hdr(inode);
877 eh->eh_depth = 0;
878 eh->eh_entries = 0;
879 eh->eh_magic = EXT4_EXT_MAGIC;
880 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
881 eh->eh_generation = 0;
882 ext4_mark_inode_dirty(handle, inode);
883}
884
885struct ext4_ext_path *
886ext4_find_extent(struct inode *inode, ext4_lblk_t block,
887 struct ext4_ext_path *path, int flags)
888{
889 struct ext4_extent_header *eh;
890 struct buffer_head *bh;
891 short int depth, i, ppos = 0;
892 int ret;
893 gfp_t gfp_flags = GFP_NOFS;
894
895 if (flags & EXT4_EX_NOFAIL)
896 gfp_flags |= __GFP_NOFAIL;
897
898 eh = ext_inode_hdr(inode);
899 depth = ext_depth(inode);
900 if (depth < 0 || depth > EXT4_MAX_EXTENT_DEPTH) {
901 EXT4_ERROR_INODE(inode, "inode has invalid extent depth: %d",
902 depth);
903 ret = -EFSCORRUPTED;
904 goto err;
905 }
906
907 if (path) {
908 ext4_ext_drop_refs(path);
909 if (depth > path[0].p_maxdepth) {
910 kfree(path);
911 path = NULL;
912 }
913 }
914 if (!path) {
915 /* account possible depth increase */
916 path = kcalloc(depth + 2, sizeof(struct ext4_ext_path),
917 gfp_flags);
918 if (unlikely(!path))
919 return ERR_PTR(-ENOMEM);
920 path[0].p_maxdepth = depth + 1;
921 }
922 path[0].p_hdr = eh;
923 path[0].p_bh = NULL;
924
925 i = depth;
926 if (!(flags & EXT4_EX_NOCACHE) && depth == 0)
927 ext4_cache_extents(inode, eh);
928 /* walk through the tree */
929 while (i) {
930 ext_debug(inode, "depth %d: num %d, max %d\n",
931 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
932
933 ext4_ext_binsearch_idx(inode, path + ppos, block);
934 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
935 path[ppos].p_depth = i;
936 path[ppos].p_ext = NULL;
937
938 bh = read_extent_tree_block(inode, path[ppos].p_idx, --i, flags);
939 if (IS_ERR(bh)) {
940 ret = PTR_ERR(bh);
941 goto err;
942 }
943
944 eh = ext_block_hdr(bh);
945 ppos++;
946 path[ppos].p_bh = bh;
947 path[ppos].p_hdr = eh;
948 }
949
950 path[ppos].p_depth = i;
951 path[ppos].p_ext = NULL;
952 path[ppos].p_idx = NULL;
953
954 /* find extent */
955 ext4_ext_binsearch(inode, path + ppos, block);
956 /* if not an empty leaf */
957 if (path[ppos].p_ext)
958 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
959
960 ext4_ext_show_path(inode, path);
961
962 return path;
963
964err:
965 ext4_free_ext_path(path);
966 return ERR_PTR(ret);
967}
968
969/*
970 * ext4_ext_insert_index:
971 * insert new index [@logical;@ptr] into the block at @curp;
972 * check where to insert: before @curp or after @curp
973 */
974static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
975 struct ext4_ext_path *curp,
976 int logical, ext4_fsblk_t ptr)
977{
978 struct ext4_extent_idx *ix;
979 int len, err;
980
981 err = ext4_ext_get_access(handle, inode, curp);
982 if (err)
983 return err;
984
985 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
986 EXT4_ERROR_INODE(inode,
987 "logical %d == ei_block %d!",
988 logical, le32_to_cpu(curp->p_idx->ei_block));
989 return -EFSCORRUPTED;
990 }
991
992 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
993 >= le16_to_cpu(curp->p_hdr->eh_max))) {
994 EXT4_ERROR_INODE(inode,
995 "eh_entries %d >= eh_max %d!",
996 le16_to_cpu(curp->p_hdr->eh_entries),
997 le16_to_cpu(curp->p_hdr->eh_max));
998 return -EFSCORRUPTED;
999 }
1000
1001 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
1002 /* insert after */
1003 ext_debug(inode, "insert new index %d after: %llu\n",
1004 logical, ptr);
1005 ix = curp->p_idx + 1;
1006 } else {
1007 /* insert before */
1008 ext_debug(inode, "insert new index %d before: %llu\n",
1009 logical, ptr);
1010 ix = curp->p_idx;
1011 }
1012
1013 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
1014 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
1015 return -EFSCORRUPTED;
1016 }
1017
1018 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
1019 BUG_ON(len < 0);
1020 if (len > 0) {
1021 ext_debug(inode, "insert new index %d: "
1022 "move %d indices from 0x%p to 0x%p\n",
1023 logical, len, ix, ix + 1);
1024 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
1025 }
1026
1027 ix->ei_block = cpu_to_le32(logical);
1028 ext4_idx_store_pblock(ix, ptr);
1029 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
1030
1031 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
1032 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
1033 return -EFSCORRUPTED;
1034 }
1035
1036 err = ext4_ext_dirty(handle, inode, curp);
1037 ext4_std_error(inode->i_sb, err);
1038
1039 return err;
1040}
1041
1042/*
1043 * ext4_ext_split:
1044 * inserts new subtree into the path, using free index entry
1045 * at depth @at:
1046 * - allocates all needed blocks (new leaf and all intermediate index blocks)
1047 * - makes decision where to split
1048 * - moves remaining extents and index entries (right to the split point)
1049 * into the newly allocated blocks
1050 * - initializes subtree
1051 */
1052static int ext4_ext_split(handle_t *handle, struct inode *inode,
1053 unsigned int flags,
1054 struct ext4_ext_path *path,
1055 struct ext4_extent *newext, int at)
1056{
1057 struct buffer_head *bh = NULL;
1058 int depth = ext_depth(inode);
1059 struct ext4_extent_header *neh;
1060 struct ext4_extent_idx *fidx;
1061 int i = at, k, m, a;
1062 ext4_fsblk_t newblock, oldblock;
1063 __le32 border;
1064 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1065 gfp_t gfp_flags = GFP_NOFS;
1066 int err = 0;
1067 size_t ext_size = 0;
1068
1069 if (flags & EXT4_EX_NOFAIL)
1070 gfp_flags |= __GFP_NOFAIL;
1071
1072 /* make decision: where to split? */
1073 /* FIXME: now decision is simplest: at current extent */
1074
1075 /* if current leaf will be split, then we should use
1076 * border from split point */
1077 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1078 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1079 return -EFSCORRUPTED;
1080 }
1081 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1082 border = path[depth].p_ext[1].ee_block;
1083 ext_debug(inode, "leaf will be split."
1084 " next leaf starts at %d\n",
1085 le32_to_cpu(border));
1086 } else {
1087 border = newext->ee_block;
1088 ext_debug(inode, "leaf will be added."
1089 " next leaf starts at %d\n",
1090 le32_to_cpu(border));
1091 }
1092
1093 /*
1094 * If error occurs, then we break processing
1095 * and mark filesystem read-only. index won't
1096 * be inserted and tree will be in consistent
1097 * state. Next mount will repair buffers too.
1098 */
1099
1100 /*
1101 * Get array to track all allocated blocks.
1102 * We need this to handle errors and free blocks
1103 * upon them.
1104 */
1105 ablocks = kcalloc(depth, sizeof(ext4_fsblk_t), gfp_flags);
1106 if (!ablocks)
1107 return -ENOMEM;
1108
1109 /* allocate all needed blocks */
1110 ext_debug(inode, "allocate %d blocks for indexes/leaf\n", depth - at);
1111 for (a = 0; a < depth - at; a++) {
1112 newblock = ext4_ext_new_meta_block(handle, inode, path,
1113 newext, &err, flags);
1114 if (newblock == 0)
1115 goto cleanup;
1116 ablocks[a] = newblock;
1117 }
1118
1119 /* initialize new leaf */
1120 newblock = ablocks[--a];
1121 if (unlikely(newblock == 0)) {
1122 EXT4_ERROR_INODE(inode, "newblock == 0!");
1123 err = -EFSCORRUPTED;
1124 goto cleanup;
1125 }
1126 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1127 if (unlikely(!bh)) {
1128 err = -ENOMEM;
1129 goto cleanup;
1130 }
1131 lock_buffer(bh);
1132
1133 err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1134 EXT4_JTR_NONE);
1135 if (err)
1136 goto cleanup;
1137
1138 neh = ext_block_hdr(bh);
1139 neh->eh_entries = 0;
1140 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1141 neh->eh_magic = EXT4_EXT_MAGIC;
1142 neh->eh_depth = 0;
1143 neh->eh_generation = 0;
1144
1145 /* move remainder of path[depth] to the new leaf */
1146 if (unlikely(path[depth].p_hdr->eh_entries !=
1147 path[depth].p_hdr->eh_max)) {
1148 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1149 path[depth].p_hdr->eh_entries,
1150 path[depth].p_hdr->eh_max);
1151 err = -EFSCORRUPTED;
1152 goto cleanup;
1153 }
1154 /* start copy from next extent */
1155 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1156 ext4_ext_show_move(inode, path, newblock, depth);
1157 if (m) {
1158 struct ext4_extent *ex;
1159 ex = EXT_FIRST_EXTENT(neh);
1160 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1161 le16_add_cpu(&neh->eh_entries, m);
1162 }
1163
1164 /* zero out unused area in the extent block */
1165 ext_size = sizeof(struct ext4_extent_header) +
1166 sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries);
1167 memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
1168 ext4_extent_block_csum_set(inode, neh);
1169 set_buffer_uptodate(bh);
1170 unlock_buffer(bh);
1171
1172 err = ext4_handle_dirty_metadata(handle, inode, bh);
1173 if (err)
1174 goto cleanup;
1175 brelse(bh);
1176 bh = NULL;
1177
1178 /* correct old leaf */
1179 if (m) {
1180 err = ext4_ext_get_access(handle, inode, path + depth);
1181 if (err)
1182 goto cleanup;
1183 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1184 err = ext4_ext_dirty(handle, inode, path + depth);
1185 if (err)
1186 goto cleanup;
1187
1188 }
1189
1190 /* create intermediate indexes */
1191 k = depth - at - 1;
1192 if (unlikely(k < 0)) {
1193 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1194 err = -EFSCORRUPTED;
1195 goto cleanup;
1196 }
1197 if (k)
1198 ext_debug(inode, "create %d intermediate indices\n", k);
1199 /* insert new index into current index block */
1200 /* current depth stored in i var */
1201 i = depth - 1;
1202 while (k--) {
1203 oldblock = newblock;
1204 newblock = ablocks[--a];
1205 bh = sb_getblk(inode->i_sb, newblock);
1206 if (unlikely(!bh)) {
1207 err = -ENOMEM;
1208 goto cleanup;
1209 }
1210 lock_buffer(bh);
1211
1212 err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1213 EXT4_JTR_NONE);
1214 if (err)
1215 goto cleanup;
1216
1217 neh = ext_block_hdr(bh);
1218 neh->eh_entries = cpu_to_le16(1);
1219 neh->eh_magic = EXT4_EXT_MAGIC;
1220 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1221 neh->eh_depth = cpu_to_le16(depth - i);
1222 neh->eh_generation = 0;
1223 fidx = EXT_FIRST_INDEX(neh);
1224 fidx->ei_block = border;
1225 ext4_idx_store_pblock(fidx, oldblock);
1226
1227 ext_debug(inode, "int.index at %d (block %llu): %u -> %llu\n",
1228 i, newblock, le32_to_cpu(border), oldblock);
1229
1230 /* move remainder of path[i] to the new index block */
1231 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1232 EXT_LAST_INDEX(path[i].p_hdr))) {
1233 EXT4_ERROR_INODE(inode,
1234 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1235 le32_to_cpu(path[i].p_ext->ee_block));
1236 err = -EFSCORRUPTED;
1237 goto cleanup;
1238 }
1239 /* start copy indexes */
1240 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1241 ext_debug(inode, "cur 0x%p, last 0x%p\n", path[i].p_idx,
1242 EXT_MAX_INDEX(path[i].p_hdr));
1243 ext4_ext_show_move(inode, path, newblock, i);
1244 if (m) {
1245 memmove(++fidx, path[i].p_idx,
1246 sizeof(struct ext4_extent_idx) * m);
1247 le16_add_cpu(&neh->eh_entries, m);
1248 }
1249 /* zero out unused area in the extent block */
1250 ext_size = sizeof(struct ext4_extent_header) +
1251 (sizeof(struct ext4_extent) * le16_to_cpu(neh->eh_entries));
1252 memset(bh->b_data + ext_size, 0,
1253 inode->i_sb->s_blocksize - ext_size);
1254 ext4_extent_block_csum_set(inode, neh);
1255 set_buffer_uptodate(bh);
1256 unlock_buffer(bh);
1257
1258 err = ext4_handle_dirty_metadata(handle, inode, bh);
1259 if (err)
1260 goto cleanup;
1261 brelse(bh);
1262 bh = NULL;
1263
1264 /* correct old index */
1265 if (m) {
1266 err = ext4_ext_get_access(handle, inode, path + i);
1267 if (err)
1268 goto cleanup;
1269 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1270 err = ext4_ext_dirty(handle, inode, path + i);
1271 if (err)
1272 goto cleanup;
1273 }
1274
1275 i--;
1276 }
1277
1278 /* insert new index */
1279 err = ext4_ext_insert_index(handle, inode, path + at,
1280 le32_to_cpu(border), newblock);
1281
1282cleanup:
1283 if (bh) {
1284 if (buffer_locked(bh))
1285 unlock_buffer(bh);
1286 brelse(bh);
1287 }
1288
1289 if (err) {
1290 /* free all allocated blocks in error case */
1291 for (i = 0; i < depth; i++) {
1292 if (!ablocks[i])
1293 continue;
1294 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1295 EXT4_FREE_BLOCKS_METADATA);
1296 }
1297 }
1298 kfree(ablocks);
1299
1300 return err;
1301}
1302
1303/*
1304 * ext4_ext_grow_indepth:
1305 * implements tree growing procedure:
1306 * - allocates new block
1307 * - moves top-level data (index block or leaf) into the new block
1308 * - initializes new top-level, creating index that points to the
1309 * just created block
1310 */
1311static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1312 unsigned int flags)
1313{
1314 struct ext4_extent_header *neh;
1315 struct buffer_head *bh;
1316 ext4_fsblk_t newblock, goal = 0;
1317 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
1318 int err = 0;
1319 size_t ext_size = 0;
1320
1321 /* Try to prepend new index to old one */
1322 if (ext_depth(inode))
1323 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
1324 if (goal > le32_to_cpu(es->s_first_data_block)) {
1325 flags |= EXT4_MB_HINT_TRY_GOAL;
1326 goal--;
1327 } else
1328 goal = ext4_inode_to_goal_block(inode);
1329 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
1330 NULL, &err);
1331 if (newblock == 0)
1332 return err;
1333
1334 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1335 if (unlikely(!bh))
1336 return -ENOMEM;
1337 lock_buffer(bh);
1338
1339 err = ext4_journal_get_create_access(handle, inode->i_sb, bh,
1340 EXT4_JTR_NONE);
1341 if (err) {
1342 unlock_buffer(bh);
1343 goto out;
1344 }
1345
1346 ext_size = sizeof(EXT4_I(inode)->i_data);
1347 /* move top-level index/leaf into new block */
1348 memmove(bh->b_data, EXT4_I(inode)->i_data, ext_size);
1349 /* zero out unused area in the extent block */
1350 memset(bh->b_data + ext_size, 0, inode->i_sb->s_blocksize - ext_size);
1351
1352 /* set size of new block */
1353 neh = ext_block_hdr(bh);
1354 /* old root could have indexes or leaves
1355 * so calculate e_max right way */
1356 if (ext_depth(inode))
1357 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1358 else
1359 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1360 neh->eh_magic = EXT4_EXT_MAGIC;
1361 ext4_extent_block_csum_set(inode, neh);
1362 set_buffer_uptodate(bh);
1363 set_buffer_verified(bh);
1364 unlock_buffer(bh);
1365
1366 err = ext4_handle_dirty_metadata(handle, inode, bh);
1367 if (err)
1368 goto out;
1369
1370 /* Update top-level index: num,max,pointer */
1371 neh = ext_inode_hdr(inode);
1372 neh->eh_entries = cpu_to_le16(1);
1373 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1374 if (neh->eh_depth == 0) {
1375 /* Root extent block becomes index block */
1376 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1377 EXT_FIRST_INDEX(neh)->ei_block =
1378 EXT_FIRST_EXTENT(neh)->ee_block;
1379 }
1380 ext_debug(inode, "new root: num %d(%d), lblock %d, ptr %llu\n",
1381 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1382 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1383 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1384
1385 le16_add_cpu(&neh->eh_depth, 1);
1386 err = ext4_mark_inode_dirty(handle, inode);
1387out:
1388 brelse(bh);
1389
1390 return err;
1391}
1392
1393/*
1394 * ext4_ext_create_new_leaf:
1395 * finds empty index and adds new leaf.
1396 * if no free index is found, then it requests in-depth growing.
1397 */
1398static struct ext4_ext_path *
1399ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1400 unsigned int mb_flags, unsigned int gb_flags,
1401 struct ext4_ext_path *path,
1402 struct ext4_extent *newext)
1403{
1404 struct ext4_ext_path *curp;
1405 int depth, i, err = 0;
1406 ext4_lblk_t ee_block = le32_to_cpu(newext->ee_block);
1407
1408repeat:
1409 i = depth = ext_depth(inode);
1410
1411 /* walk up to the tree and look for free index entry */
1412 curp = path + depth;
1413 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1414 i--;
1415 curp--;
1416 }
1417
1418 /* we use already allocated block for index block,
1419 * so subsequent data blocks should be contiguous */
1420 if (EXT_HAS_FREE_INDEX(curp)) {
1421 /* if we found index with free entry, then use that
1422 * entry: create all needed subtree and add new leaf */
1423 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
1424 if (err)
1425 goto errout;
1426
1427 /* refill path */
1428 path = ext4_find_extent(inode, ee_block, path, gb_flags);
1429 return path;
1430 }
1431
1432 /* tree is full, time to grow in depth */
1433 err = ext4_ext_grow_indepth(handle, inode, mb_flags);
1434 if (err)
1435 goto errout;
1436
1437 /* refill path */
1438 path = ext4_find_extent(inode, ee_block, path, gb_flags);
1439 if (IS_ERR(path))
1440 return path;
1441
1442 /*
1443 * only first (depth 0 -> 1) produces free space;
1444 * in all other cases we have to split the grown tree
1445 */
1446 depth = ext_depth(inode);
1447 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1448 /* now we need to split */
1449 goto repeat;
1450 }
1451
1452 return path;
1453
1454errout:
1455 ext4_free_ext_path(path);
1456 return ERR_PTR(err);
1457}
1458
1459/*
1460 * search the closest allocated block to the left for *logical
1461 * and returns it at @logical + it's physical address at @phys
1462 * if *logical is the smallest allocated block, the function
1463 * returns 0 at @phys
1464 * return value contains 0 (success) or error code
1465 */
1466static int ext4_ext_search_left(struct inode *inode,
1467 struct ext4_ext_path *path,
1468 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1469{
1470 struct ext4_extent_idx *ix;
1471 struct ext4_extent *ex;
1472 int depth, ee_len;
1473
1474 if (unlikely(path == NULL)) {
1475 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1476 return -EFSCORRUPTED;
1477 }
1478 depth = path->p_depth;
1479 *phys = 0;
1480
1481 if (depth == 0 && path->p_ext == NULL)
1482 return 0;
1483
1484 /* usually extent in the path covers blocks smaller
1485 * then *logical, but it can be that extent is the
1486 * first one in the file */
1487
1488 ex = path[depth].p_ext;
1489 ee_len = ext4_ext_get_actual_len(ex);
1490 if (*logical < le32_to_cpu(ex->ee_block)) {
1491 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1492 EXT4_ERROR_INODE(inode,
1493 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1494 *logical, le32_to_cpu(ex->ee_block));
1495 return -EFSCORRUPTED;
1496 }
1497 while (--depth >= 0) {
1498 ix = path[depth].p_idx;
1499 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1500 EXT4_ERROR_INODE(inode,
1501 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1502 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1503 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block),
1504 depth);
1505 return -EFSCORRUPTED;
1506 }
1507 }
1508 return 0;
1509 }
1510
1511 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1512 EXT4_ERROR_INODE(inode,
1513 "logical %d < ee_block %d + ee_len %d!",
1514 *logical, le32_to_cpu(ex->ee_block), ee_len);
1515 return -EFSCORRUPTED;
1516 }
1517
1518 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1519 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1520 return 0;
1521}
1522
1523/*
1524 * Search the closest allocated block to the right for *logical
1525 * and returns it at @logical + it's physical address at @phys.
1526 * If not exists, return 0 and @phys is set to 0. We will return
1527 * 1 which means we found an allocated block and ret_ex is valid.
1528 * Or return a (< 0) error code.
1529 */
1530static int ext4_ext_search_right(struct inode *inode,
1531 struct ext4_ext_path *path,
1532 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1533 struct ext4_extent *ret_ex)
1534{
1535 struct buffer_head *bh = NULL;
1536 struct ext4_extent_header *eh;
1537 struct ext4_extent_idx *ix;
1538 struct ext4_extent *ex;
1539 int depth; /* Note, NOT eh_depth; depth from top of tree */
1540 int ee_len;
1541
1542 if (unlikely(path == NULL)) {
1543 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1544 return -EFSCORRUPTED;
1545 }
1546 depth = path->p_depth;
1547 *phys = 0;
1548
1549 if (depth == 0 && path->p_ext == NULL)
1550 return 0;
1551
1552 /* usually extent in the path covers blocks smaller
1553 * then *logical, but it can be that extent is the
1554 * first one in the file */
1555
1556 ex = path[depth].p_ext;
1557 ee_len = ext4_ext_get_actual_len(ex);
1558 if (*logical < le32_to_cpu(ex->ee_block)) {
1559 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1560 EXT4_ERROR_INODE(inode,
1561 "first_extent(path[%d].p_hdr) != ex",
1562 depth);
1563 return -EFSCORRUPTED;
1564 }
1565 while (--depth >= 0) {
1566 ix = path[depth].p_idx;
1567 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1568 EXT4_ERROR_INODE(inode,
1569 "ix != EXT_FIRST_INDEX *logical %d!",
1570 *logical);
1571 return -EFSCORRUPTED;
1572 }
1573 }
1574 goto found_extent;
1575 }
1576
1577 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1578 EXT4_ERROR_INODE(inode,
1579 "logical %d < ee_block %d + ee_len %d!",
1580 *logical, le32_to_cpu(ex->ee_block), ee_len);
1581 return -EFSCORRUPTED;
1582 }
1583
1584 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1585 /* next allocated block in this leaf */
1586 ex++;
1587 goto found_extent;
1588 }
1589
1590 /* go up and search for index to the right */
1591 while (--depth >= 0) {
1592 ix = path[depth].p_idx;
1593 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1594 goto got_index;
1595 }
1596
1597 /* we've gone up to the root and found no index to the right */
1598 return 0;
1599
1600got_index:
1601 /* we've found index to the right, let's
1602 * follow it and find the closest allocated
1603 * block to the right */
1604 ix++;
1605 while (++depth < path->p_depth) {
1606 /* subtract from p_depth to get proper eh_depth */
1607 bh = read_extent_tree_block(inode, ix, path->p_depth - depth, 0);
1608 if (IS_ERR(bh))
1609 return PTR_ERR(bh);
1610 eh = ext_block_hdr(bh);
1611 ix = EXT_FIRST_INDEX(eh);
1612 put_bh(bh);
1613 }
1614
1615 bh = read_extent_tree_block(inode, ix, path->p_depth - depth, 0);
1616 if (IS_ERR(bh))
1617 return PTR_ERR(bh);
1618 eh = ext_block_hdr(bh);
1619 ex = EXT_FIRST_EXTENT(eh);
1620found_extent:
1621 *logical = le32_to_cpu(ex->ee_block);
1622 *phys = ext4_ext_pblock(ex);
1623 if (ret_ex)
1624 *ret_ex = *ex;
1625 if (bh)
1626 put_bh(bh);
1627 return 1;
1628}
1629
1630/*
1631 * ext4_ext_next_allocated_block:
1632 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1633 * NOTE: it considers block number from index entry as
1634 * allocated block. Thus, index entries have to be consistent
1635 * with leaves.
1636 */
1637ext4_lblk_t
1638ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1639{
1640 int depth;
1641
1642 BUG_ON(path == NULL);
1643 depth = path->p_depth;
1644
1645 if (depth == 0 && path->p_ext == NULL)
1646 return EXT_MAX_BLOCKS;
1647
1648 while (depth >= 0) {
1649 struct ext4_ext_path *p = &path[depth];
1650
1651 if (depth == path->p_depth) {
1652 /* leaf */
1653 if (p->p_ext && p->p_ext != EXT_LAST_EXTENT(p->p_hdr))
1654 return le32_to_cpu(p->p_ext[1].ee_block);
1655 } else {
1656 /* index */
1657 if (p->p_idx != EXT_LAST_INDEX(p->p_hdr))
1658 return le32_to_cpu(p->p_idx[1].ei_block);
1659 }
1660 depth--;
1661 }
1662
1663 return EXT_MAX_BLOCKS;
1664}
1665
1666/*
1667 * ext4_ext_next_leaf_block:
1668 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1669 */
1670static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1671{
1672 int depth;
1673
1674 BUG_ON(path == NULL);
1675 depth = path->p_depth;
1676
1677 /* zero-tree has no leaf blocks at all */
1678 if (depth == 0)
1679 return EXT_MAX_BLOCKS;
1680
1681 /* go to index block */
1682 depth--;
1683
1684 while (depth >= 0) {
1685 if (path[depth].p_idx !=
1686 EXT_LAST_INDEX(path[depth].p_hdr))
1687 return (ext4_lblk_t)
1688 le32_to_cpu(path[depth].p_idx[1].ei_block);
1689 depth--;
1690 }
1691
1692 return EXT_MAX_BLOCKS;
1693}
1694
1695/*
1696 * ext4_ext_correct_indexes:
1697 * if leaf gets modified and modified extent is first in the leaf,
1698 * then we have to correct all indexes above.
1699 * TODO: do we need to correct tree in all cases?
1700 */
1701static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1702 struct ext4_ext_path *path)
1703{
1704 struct ext4_extent_header *eh;
1705 int depth = ext_depth(inode);
1706 struct ext4_extent *ex;
1707 __le32 border;
1708 int k, err = 0;
1709
1710 eh = path[depth].p_hdr;
1711 ex = path[depth].p_ext;
1712
1713 if (unlikely(ex == NULL || eh == NULL)) {
1714 EXT4_ERROR_INODE(inode,
1715 "ex %p == NULL or eh %p == NULL", ex, eh);
1716 return -EFSCORRUPTED;
1717 }
1718
1719 if (depth == 0) {
1720 /* there is no tree at all */
1721 return 0;
1722 }
1723
1724 if (ex != EXT_FIRST_EXTENT(eh)) {
1725 /* we correct tree if first leaf got modified only */
1726 return 0;
1727 }
1728
1729 /*
1730 * TODO: we need correction if border is smaller than current one
1731 */
1732 k = depth - 1;
1733 border = path[depth].p_ext->ee_block;
1734 err = ext4_ext_get_access(handle, inode, path + k);
1735 if (err)
1736 return err;
1737 path[k].p_idx->ei_block = border;
1738 err = ext4_ext_dirty(handle, inode, path + k);
1739 if (err)
1740 return err;
1741
1742 while (k--) {
1743 /* change all left-side indexes */
1744 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1745 break;
1746 err = ext4_ext_get_access(handle, inode, path + k);
1747 if (err)
1748 goto clean;
1749 path[k].p_idx->ei_block = border;
1750 err = ext4_ext_dirty(handle, inode, path + k);
1751 if (err)
1752 goto clean;
1753 }
1754 return 0;
1755
1756clean:
1757 /*
1758 * The path[k].p_bh is either unmodified or with no verified bit
1759 * set (see ext4_ext_get_access()). So just clear the verified bit
1760 * of the successfully modified extents buffers, which will force
1761 * these extents to be checked to avoid using inconsistent data.
1762 */
1763 while (++k < depth)
1764 clear_buffer_verified(path[k].p_bh);
1765
1766 return err;
1767}
1768
1769static int ext4_can_extents_be_merged(struct inode *inode,
1770 struct ext4_extent *ex1,
1771 struct ext4_extent *ex2)
1772{
1773 unsigned short ext1_ee_len, ext2_ee_len;
1774
1775 if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
1776 return 0;
1777
1778 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1779 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1780
1781 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1782 le32_to_cpu(ex2->ee_block))
1783 return 0;
1784
1785 if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1786 return 0;
1787
1788 if (ext4_ext_is_unwritten(ex1) &&
1789 ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)
1790 return 0;
1791#ifdef AGGRESSIVE_TEST
1792 if (ext1_ee_len >= 4)
1793 return 0;
1794#endif
1795
1796 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1797 return 1;
1798 return 0;
1799}
1800
1801/*
1802 * This function tries to merge the "ex" extent to the next extent in the tree.
1803 * It always tries to merge towards right. If you want to merge towards
1804 * left, pass "ex - 1" as argument instead of "ex".
1805 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1806 * 1 if they got merged.
1807 */
1808static int ext4_ext_try_to_merge_right(struct inode *inode,
1809 struct ext4_ext_path *path,
1810 struct ext4_extent *ex)
1811{
1812 struct ext4_extent_header *eh;
1813 unsigned int depth, len;
1814 int merge_done = 0, unwritten;
1815
1816 depth = ext_depth(inode);
1817 BUG_ON(path[depth].p_hdr == NULL);
1818 eh = path[depth].p_hdr;
1819
1820 while (ex < EXT_LAST_EXTENT(eh)) {
1821 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1822 break;
1823 /* merge with next extent! */
1824 unwritten = ext4_ext_is_unwritten(ex);
1825 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1826 + ext4_ext_get_actual_len(ex + 1));
1827 if (unwritten)
1828 ext4_ext_mark_unwritten(ex);
1829
1830 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1831 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1832 * sizeof(struct ext4_extent);
1833 memmove(ex + 1, ex + 2, len);
1834 }
1835 le16_add_cpu(&eh->eh_entries, -1);
1836 merge_done = 1;
1837 WARN_ON(eh->eh_entries == 0);
1838 if (!eh->eh_entries)
1839 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1840 }
1841
1842 return merge_done;
1843}
1844
1845/*
1846 * This function does a very simple check to see if we can collapse
1847 * an extent tree with a single extent tree leaf block into the inode.
1848 */
1849static void ext4_ext_try_to_merge_up(handle_t *handle,
1850 struct inode *inode,
1851 struct ext4_ext_path *path)
1852{
1853 size_t s;
1854 unsigned max_root = ext4_ext_space_root(inode, 0);
1855 ext4_fsblk_t blk;
1856
1857 if ((path[0].p_depth != 1) ||
1858 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1859 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1860 return;
1861
1862 /*
1863 * We need to modify the block allocation bitmap and the block
1864 * group descriptor to release the extent tree block. If we
1865 * can't get the journal credits, give up.
1866 */
1867 if (ext4_journal_extend(handle, 2,
1868 ext4_free_metadata_revoke_credits(inode->i_sb, 1)))
1869 return;
1870
1871 /*
1872 * Copy the extent data up to the inode
1873 */
1874 blk = ext4_idx_pblock(path[0].p_idx);
1875 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1876 sizeof(struct ext4_extent_idx);
1877 s += sizeof(struct ext4_extent_header);
1878
1879 path[1].p_maxdepth = path[0].p_maxdepth;
1880 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1881 path[0].p_depth = 0;
1882 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1883 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1884 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1885
1886 ext4_ext_path_brelse(path + 1);
1887 ext4_free_blocks(handle, inode, NULL, blk, 1,
1888 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1889}
1890
1891/*
1892 * This function tries to merge the @ex extent to neighbours in the tree, then
1893 * tries to collapse the extent tree into the inode.
1894 */
1895static void ext4_ext_try_to_merge(handle_t *handle,
1896 struct inode *inode,
1897 struct ext4_ext_path *path,
1898 struct ext4_extent *ex)
1899{
1900 struct ext4_extent_header *eh;
1901 unsigned int depth;
1902 int merge_done = 0;
1903
1904 depth = ext_depth(inode);
1905 BUG_ON(path[depth].p_hdr == NULL);
1906 eh = path[depth].p_hdr;
1907
1908 if (ex > EXT_FIRST_EXTENT(eh))
1909 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1910
1911 if (!merge_done)
1912 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1913
1914 ext4_ext_try_to_merge_up(handle, inode, path);
1915}
1916
1917/*
1918 * check if a portion of the "newext" extent overlaps with an
1919 * existing extent.
1920 *
1921 * If there is an overlap discovered, it updates the length of the newext
1922 * such that there will be no overlap, and then returns 1.
1923 * If there is no overlap found, it returns 0.
1924 */
1925static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1926 struct inode *inode,
1927 struct ext4_extent *newext,
1928 struct ext4_ext_path *path)
1929{
1930 ext4_lblk_t b1, b2;
1931 unsigned int depth, len1;
1932 unsigned int ret = 0;
1933
1934 b1 = le32_to_cpu(newext->ee_block);
1935 len1 = ext4_ext_get_actual_len(newext);
1936 depth = ext_depth(inode);
1937 if (!path[depth].p_ext)
1938 goto out;
1939 b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
1940
1941 /*
1942 * get the next allocated block if the extent in the path
1943 * is before the requested block(s)
1944 */
1945 if (b2 < b1) {
1946 b2 = ext4_ext_next_allocated_block(path);
1947 if (b2 == EXT_MAX_BLOCKS)
1948 goto out;
1949 b2 = EXT4_LBLK_CMASK(sbi, b2);
1950 }
1951
1952 /* check for wrap through zero on extent logical start block*/
1953 if (b1 + len1 < b1) {
1954 len1 = EXT_MAX_BLOCKS - b1;
1955 newext->ee_len = cpu_to_le16(len1);
1956 ret = 1;
1957 }
1958
1959 /* check for overlap */
1960 if (b1 + len1 > b2) {
1961 newext->ee_len = cpu_to_le16(b2 - b1);
1962 ret = 1;
1963 }
1964out:
1965 return ret;
1966}
1967
1968/*
1969 * ext4_ext_insert_extent:
1970 * tries to merge requested extent into the existing extent or
1971 * inserts requested extent as new one into the tree,
1972 * creating new leaf in the no-space case.
1973 */
1974struct ext4_ext_path *
1975ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1976 struct ext4_ext_path *path,
1977 struct ext4_extent *newext, int gb_flags)
1978{
1979 struct ext4_extent_header *eh;
1980 struct ext4_extent *ex, *fex;
1981 struct ext4_extent *nearex; /* nearest extent */
1982 int depth, len, err = 0;
1983 ext4_lblk_t next;
1984 int mb_flags = 0, unwritten;
1985
1986 if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1987 mb_flags |= EXT4_MB_DELALLOC_RESERVED;
1988 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1989 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1990 err = -EFSCORRUPTED;
1991 goto errout;
1992 }
1993 depth = ext_depth(inode);
1994 ex = path[depth].p_ext;
1995 eh = path[depth].p_hdr;
1996 if (unlikely(path[depth].p_hdr == NULL)) {
1997 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1998 err = -EFSCORRUPTED;
1999 goto errout;
2000 }
2001
2002 /* try to insert block into found extent and return */
2003 if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
2004
2005 /*
2006 * Try to see whether we should rather test the extent on
2007 * right from ex, or from the left of ex. This is because
2008 * ext4_find_extent() can return either extent on the
2009 * left, or on the right from the searched position. This
2010 * will make merging more effective.
2011 */
2012 if (ex < EXT_LAST_EXTENT(eh) &&
2013 (le32_to_cpu(ex->ee_block) +
2014 ext4_ext_get_actual_len(ex) <
2015 le32_to_cpu(newext->ee_block))) {
2016 ex += 1;
2017 goto prepend;
2018 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
2019 (le32_to_cpu(newext->ee_block) +
2020 ext4_ext_get_actual_len(newext) <
2021 le32_to_cpu(ex->ee_block)))
2022 ex -= 1;
2023
2024 /* Try to append newex to the ex */
2025 if (ext4_can_extents_be_merged(inode, ex, newext)) {
2026 ext_debug(inode, "append [%d]%d block to %u:[%d]%d"
2027 "(from %llu)\n",
2028 ext4_ext_is_unwritten(newext),
2029 ext4_ext_get_actual_len(newext),
2030 le32_to_cpu(ex->ee_block),
2031 ext4_ext_is_unwritten(ex),
2032 ext4_ext_get_actual_len(ex),
2033 ext4_ext_pblock(ex));
2034 err = ext4_ext_get_access(handle, inode,
2035 path + depth);
2036 if (err)
2037 goto errout;
2038 unwritten = ext4_ext_is_unwritten(ex);
2039 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2040 + ext4_ext_get_actual_len(newext));
2041 if (unwritten)
2042 ext4_ext_mark_unwritten(ex);
2043 nearex = ex;
2044 goto merge;
2045 }
2046
2047prepend:
2048 /* Try to prepend newex to the ex */
2049 if (ext4_can_extents_be_merged(inode, newext, ex)) {
2050 ext_debug(inode, "prepend %u[%d]%d block to %u:[%d]%d"
2051 "(from %llu)\n",
2052 le32_to_cpu(newext->ee_block),
2053 ext4_ext_is_unwritten(newext),
2054 ext4_ext_get_actual_len(newext),
2055 le32_to_cpu(ex->ee_block),
2056 ext4_ext_is_unwritten(ex),
2057 ext4_ext_get_actual_len(ex),
2058 ext4_ext_pblock(ex));
2059 err = ext4_ext_get_access(handle, inode,
2060 path + depth);
2061 if (err)
2062 goto errout;
2063
2064 unwritten = ext4_ext_is_unwritten(ex);
2065 ex->ee_block = newext->ee_block;
2066 ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
2067 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2068 + ext4_ext_get_actual_len(newext));
2069 if (unwritten)
2070 ext4_ext_mark_unwritten(ex);
2071 nearex = ex;
2072 goto merge;
2073 }
2074 }
2075
2076 depth = ext_depth(inode);
2077 eh = path[depth].p_hdr;
2078 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
2079 goto has_space;
2080
2081 /* probably next leaf has space for us? */
2082 fex = EXT_LAST_EXTENT(eh);
2083 next = EXT_MAX_BLOCKS;
2084 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
2085 next = ext4_ext_next_leaf_block(path);
2086 if (next != EXT_MAX_BLOCKS) {
2087 struct ext4_ext_path *npath;
2088
2089 ext_debug(inode, "next leaf block - %u\n", next);
2090 npath = ext4_find_extent(inode, next, NULL, gb_flags);
2091 if (IS_ERR(npath)) {
2092 err = PTR_ERR(npath);
2093 goto errout;
2094 }
2095 BUG_ON(npath->p_depth != path->p_depth);
2096 eh = npath[depth].p_hdr;
2097 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2098 ext_debug(inode, "next leaf isn't full(%d)\n",
2099 le16_to_cpu(eh->eh_entries));
2100 ext4_free_ext_path(path);
2101 path = npath;
2102 goto has_space;
2103 }
2104 ext_debug(inode, "next leaf has no free space(%d,%d)\n",
2105 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2106 ext4_free_ext_path(npath);
2107 }
2108
2109 /*
2110 * There is no free space in the found leaf.
2111 * We're gonna add a new leaf in the tree.
2112 */
2113 if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2114 mb_flags |= EXT4_MB_USE_RESERVED;
2115 path = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2116 path, newext);
2117 if (IS_ERR(path))
2118 return path;
2119 depth = ext_depth(inode);
2120 eh = path[depth].p_hdr;
2121
2122has_space:
2123 nearex = path[depth].p_ext;
2124
2125 err = ext4_ext_get_access(handle, inode, path + depth);
2126 if (err)
2127 goto errout;
2128
2129 if (!nearex) {
2130 /* there is no extent in this leaf, create first one */
2131 ext_debug(inode, "first extent in the leaf: %u:%llu:[%d]%d\n",
2132 le32_to_cpu(newext->ee_block),
2133 ext4_ext_pblock(newext),
2134 ext4_ext_is_unwritten(newext),
2135 ext4_ext_get_actual_len(newext));
2136 nearex = EXT_FIRST_EXTENT(eh);
2137 } else {
2138 if (le32_to_cpu(newext->ee_block)
2139 > le32_to_cpu(nearex->ee_block)) {
2140 /* Insert after */
2141 ext_debug(inode, "insert %u:%llu:[%d]%d before: "
2142 "nearest %p\n",
2143 le32_to_cpu(newext->ee_block),
2144 ext4_ext_pblock(newext),
2145 ext4_ext_is_unwritten(newext),
2146 ext4_ext_get_actual_len(newext),
2147 nearex);
2148 nearex++;
2149 } else {
2150 /* Insert before */
2151 BUG_ON(newext->ee_block == nearex->ee_block);
2152 ext_debug(inode, "insert %u:%llu:[%d]%d after: "
2153 "nearest %p\n",
2154 le32_to_cpu(newext->ee_block),
2155 ext4_ext_pblock(newext),
2156 ext4_ext_is_unwritten(newext),
2157 ext4_ext_get_actual_len(newext),
2158 nearex);
2159 }
2160 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2161 if (len > 0) {
2162 ext_debug(inode, "insert %u:%llu:[%d]%d: "
2163 "move %d extents from 0x%p to 0x%p\n",
2164 le32_to_cpu(newext->ee_block),
2165 ext4_ext_pblock(newext),
2166 ext4_ext_is_unwritten(newext),
2167 ext4_ext_get_actual_len(newext),
2168 len, nearex, nearex + 1);
2169 memmove(nearex + 1, nearex,
2170 len * sizeof(struct ext4_extent));
2171 }
2172 }
2173
2174 le16_add_cpu(&eh->eh_entries, 1);
2175 path[depth].p_ext = nearex;
2176 nearex->ee_block = newext->ee_block;
2177 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2178 nearex->ee_len = newext->ee_len;
2179
2180merge:
2181 /* try to merge extents */
2182 if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2183 ext4_ext_try_to_merge(handle, inode, path, nearex);
2184
2185 /* time to correct all indexes above */
2186 err = ext4_ext_correct_indexes(handle, inode, path);
2187 if (err)
2188 goto errout;
2189
2190 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2191 if (err)
2192 goto errout;
2193
2194 return path;
2195
2196errout:
2197 ext4_free_ext_path(path);
2198 return ERR_PTR(err);
2199}
2200
2201static int ext4_fill_es_cache_info(struct inode *inode,
2202 ext4_lblk_t block, ext4_lblk_t num,
2203 struct fiemap_extent_info *fieinfo)
2204{
2205 ext4_lblk_t next, end = block + num - 1;
2206 struct extent_status es;
2207 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2208 unsigned int flags;
2209 int err;
2210
2211 while (block <= end) {
2212 next = 0;
2213 flags = 0;
2214 if (!ext4_es_lookup_extent(inode, block, &next, &es))
2215 break;
2216 if (ext4_es_is_unwritten(&es))
2217 flags |= FIEMAP_EXTENT_UNWRITTEN;
2218 if (ext4_es_is_delayed(&es))
2219 flags |= (FIEMAP_EXTENT_DELALLOC |
2220 FIEMAP_EXTENT_UNKNOWN);
2221 if (ext4_es_is_hole(&es))
2222 flags |= EXT4_FIEMAP_EXTENT_HOLE;
2223 if (next == 0)
2224 flags |= FIEMAP_EXTENT_LAST;
2225 if (flags & (FIEMAP_EXTENT_DELALLOC|
2226 EXT4_FIEMAP_EXTENT_HOLE))
2227 es.es_pblk = 0;
2228 else
2229 es.es_pblk = ext4_es_pblock(&es);
2230 err = fiemap_fill_next_extent(fieinfo,
2231 (__u64)es.es_lblk << blksize_bits,
2232 (__u64)es.es_pblk << blksize_bits,
2233 (__u64)es.es_len << blksize_bits,
2234 flags);
2235 if (next == 0)
2236 break;
2237 block = next;
2238 if (err < 0)
2239 return err;
2240 if (err == 1)
2241 return 0;
2242 }
2243 return 0;
2244}
2245
2246
2247/*
2248 * ext4_ext_find_hole - find hole around given block according to the given path
2249 * @inode: inode we lookup in
2250 * @path: path in extent tree to @lblk
2251 * @lblk: pointer to logical block around which we want to determine hole
2252 *
2253 * Determine hole length (and start if easily possible) around given logical
2254 * block. We don't try too hard to find the beginning of the hole but @path
2255 * actually points to extent before @lblk, we provide it.
2256 *
2257 * The function returns the length of a hole starting at @lblk. We update @lblk
2258 * to the beginning of the hole if we managed to find it.
2259 */
2260static ext4_lblk_t ext4_ext_find_hole(struct inode *inode,
2261 struct ext4_ext_path *path,
2262 ext4_lblk_t *lblk)
2263{
2264 int depth = ext_depth(inode);
2265 struct ext4_extent *ex;
2266 ext4_lblk_t len;
2267
2268 ex = path[depth].p_ext;
2269 if (ex == NULL) {
2270 /* there is no extent yet, so gap is [0;-] */
2271 *lblk = 0;
2272 len = EXT_MAX_BLOCKS;
2273 } else if (*lblk < le32_to_cpu(ex->ee_block)) {
2274 len = le32_to_cpu(ex->ee_block) - *lblk;
2275 } else if (*lblk >= le32_to_cpu(ex->ee_block)
2276 + ext4_ext_get_actual_len(ex)) {
2277 ext4_lblk_t next;
2278
2279 *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
2280 next = ext4_ext_next_allocated_block(path);
2281 BUG_ON(next == *lblk);
2282 len = next - *lblk;
2283 } else {
2284 BUG();
2285 }
2286 return len;
2287}
2288
2289/*
2290 * ext4_ext_rm_idx:
2291 * removes index from the index block.
2292 */
2293static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2294 struct ext4_ext_path *path, int depth)
2295{
2296 int err;
2297 ext4_fsblk_t leaf;
2298 int k = depth - 1;
2299
2300 /* free index block */
2301 leaf = ext4_idx_pblock(path[k].p_idx);
2302 if (unlikely(path[k].p_hdr->eh_entries == 0)) {
2303 EXT4_ERROR_INODE(inode, "path[%d].p_hdr->eh_entries == 0", k);
2304 return -EFSCORRUPTED;
2305 }
2306 err = ext4_ext_get_access(handle, inode, path + k);
2307 if (err)
2308 return err;
2309
2310 if (path[k].p_idx != EXT_LAST_INDEX(path[k].p_hdr)) {
2311 int len = EXT_LAST_INDEX(path[k].p_hdr) - path[k].p_idx;
2312 len *= sizeof(struct ext4_extent_idx);
2313 memmove(path[k].p_idx, path[k].p_idx + 1, len);
2314 }
2315
2316 le16_add_cpu(&path[k].p_hdr->eh_entries, -1);
2317 err = ext4_ext_dirty(handle, inode, path + k);
2318 if (err)
2319 return err;
2320 ext_debug(inode, "index is empty, remove it, free block %llu\n", leaf);
2321 trace_ext4_ext_rm_idx(inode, leaf);
2322
2323 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2324 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2325
2326 while (--k >= 0) {
2327 if (path[k + 1].p_idx != EXT_FIRST_INDEX(path[k + 1].p_hdr))
2328 break;
2329 err = ext4_ext_get_access(handle, inode, path + k);
2330 if (err)
2331 goto clean;
2332 path[k].p_idx->ei_block = path[k + 1].p_idx->ei_block;
2333 err = ext4_ext_dirty(handle, inode, path + k);
2334 if (err)
2335 goto clean;
2336 }
2337 return 0;
2338
2339clean:
2340 /*
2341 * The path[k].p_bh is either unmodified or with no verified bit
2342 * set (see ext4_ext_get_access()). So just clear the verified bit
2343 * of the successfully modified extents buffers, which will force
2344 * these extents to be checked to avoid using inconsistent data.
2345 */
2346 while (++k < depth)
2347 clear_buffer_verified(path[k].p_bh);
2348
2349 return err;
2350}
2351
2352/*
2353 * ext4_ext_calc_credits_for_single_extent:
2354 * This routine returns max. credits that needed to insert an extent
2355 * to the extent tree.
2356 * When pass the actual path, the caller should calculate credits
2357 * under i_data_sem.
2358 */
2359int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2360 struct ext4_ext_path *path)
2361{
2362 if (path) {
2363 int depth = ext_depth(inode);
2364 int ret = 0;
2365
2366 /* probably there is space in leaf? */
2367 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2368 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2369
2370 /*
2371 * There are some space in the leaf tree, no
2372 * need to account for leaf block credit
2373 *
2374 * bitmaps and block group descriptor blocks
2375 * and other metadata blocks still need to be
2376 * accounted.
2377 */
2378 /* 1 bitmap, 1 block group descriptor */
2379 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2380 return ret;
2381 }
2382 }
2383
2384 return ext4_chunk_trans_blocks(inode, nrblocks);
2385}
2386
2387/*
2388 * How many index/leaf blocks need to change/allocate to add @extents extents?
2389 *
2390 * If we add a single extent, then in the worse case, each tree level
2391 * index/leaf need to be changed in case of the tree split.
2392 *
2393 * If more extents are inserted, they could cause the whole tree split more
2394 * than once, but this is really rare.
2395 */
2396int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2397{
2398 int index;
2399 int depth;
2400
2401 /* If we are converting the inline data, only one is needed here. */
2402 if (ext4_has_inline_data(inode))
2403 return 1;
2404
2405 depth = ext_depth(inode);
2406
2407 if (extents <= 1)
2408 index = depth * 2;
2409 else
2410 index = depth * 3;
2411
2412 return index;
2413}
2414
2415static inline int get_default_free_blocks_flags(struct inode *inode)
2416{
2417 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode) ||
2418 ext4_test_inode_flag(inode, EXT4_INODE_EA_INODE))
2419 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2420 else if (ext4_should_journal_data(inode))
2421 return EXT4_FREE_BLOCKS_FORGET;
2422 return 0;
2423}
2424
2425/*
2426 * ext4_rereserve_cluster - increment the reserved cluster count when
2427 * freeing a cluster with a pending reservation
2428 *
2429 * @inode - file containing the cluster
2430 * @lblk - logical block in cluster to be reserved
2431 *
2432 * Increments the reserved cluster count and adjusts quota in a bigalloc
2433 * file system when freeing a partial cluster containing at least one
2434 * delayed and unwritten block. A partial cluster meeting that
2435 * requirement will have a pending reservation. If so, the
2436 * RERESERVE_CLUSTER flag is used when calling ext4_free_blocks() to
2437 * defer reserved and allocated space accounting to a subsequent call
2438 * to this function.
2439 */
2440static void ext4_rereserve_cluster(struct inode *inode, ext4_lblk_t lblk)
2441{
2442 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2443 struct ext4_inode_info *ei = EXT4_I(inode);
2444
2445 dquot_reclaim_block(inode, EXT4_C2B(sbi, 1));
2446
2447 spin_lock(&ei->i_block_reservation_lock);
2448 ei->i_reserved_data_blocks++;
2449 percpu_counter_add(&sbi->s_dirtyclusters_counter, 1);
2450 spin_unlock(&ei->i_block_reservation_lock);
2451
2452 percpu_counter_add(&sbi->s_freeclusters_counter, 1);
2453 ext4_remove_pending(inode, lblk);
2454}
2455
2456static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2457 struct ext4_extent *ex,
2458 struct partial_cluster *partial,
2459 ext4_lblk_t from, ext4_lblk_t to)
2460{
2461 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2462 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2463 ext4_fsblk_t last_pblk, pblk;
2464 ext4_lblk_t num;
2465 int flags;
2466
2467 /* only extent tail removal is allowed */
2468 if (from < le32_to_cpu(ex->ee_block) ||
2469 to != le32_to_cpu(ex->ee_block) + ee_len - 1) {
2470 ext4_error(sbi->s_sb,
2471 "strange request: removal(2) %u-%u from %u:%u",
2472 from, to, le32_to_cpu(ex->ee_block), ee_len);
2473 return 0;
2474 }
2475
2476#ifdef EXTENTS_STATS
2477 spin_lock(&sbi->s_ext_stats_lock);
2478 sbi->s_ext_blocks += ee_len;
2479 sbi->s_ext_extents++;
2480 if (ee_len < sbi->s_ext_min)
2481 sbi->s_ext_min = ee_len;
2482 if (ee_len > sbi->s_ext_max)
2483 sbi->s_ext_max = ee_len;
2484 if (ext_depth(inode) > sbi->s_depth_max)
2485 sbi->s_depth_max = ext_depth(inode);
2486 spin_unlock(&sbi->s_ext_stats_lock);
2487#endif
2488
2489 trace_ext4_remove_blocks(inode, ex, from, to, partial);
2490
2491 /*
2492 * if we have a partial cluster, and it's different from the
2493 * cluster of the last block in the extent, we free it
2494 */
2495 last_pblk = ext4_ext_pblock(ex) + ee_len - 1;
2496
2497 if (partial->state != initial &&
2498 partial->pclu != EXT4_B2C(sbi, last_pblk)) {
2499 if (partial->state == tofree) {
2500 flags = get_default_free_blocks_flags(inode);
2501 if (ext4_is_pending(inode, partial->lblk))
2502 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2503 ext4_free_blocks(handle, inode, NULL,
2504 EXT4_C2B(sbi, partial->pclu),
2505 sbi->s_cluster_ratio, flags);
2506 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2507 ext4_rereserve_cluster(inode, partial->lblk);
2508 }
2509 partial->state = initial;
2510 }
2511
2512 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2513 pblk = ext4_ext_pblock(ex) + ee_len - num;
2514
2515 /*
2516 * We free the partial cluster at the end of the extent (if any),
2517 * unless the cluster is used by another extent (partial_cluster
2518 * state is nofree). If a partial cluster exists here, it must be
2519 * shared with the last block in the extent.
2520 */
2521 flags = get_default_free_blocks_flags(inode);
2522
2523 /* partial, left end cluster aligned, right end unaligned */
2524 if ((EXT4_LBLK_COFF(sbi, to) != sbi->s_cluster_ratio - 1) &&
2525 (EXT4_LBLK_CMASK(sbi, to) >= from) &&
2526 (partial->state != nofree)) {
2527 if (ext4_is_pending(inode, to))
2528 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2529 ext4_free_blocks(handle, inode, NULL,
2530 EXT4_PBLK_CMASK(sbi, last_pblk),
2531 sbi->s_cluster_ratio, flags);
2532 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2533 ext4_rereserve_cluster(inode, to);
2534 partial->state = initial;
2535 flags = get_default_free_blocks_flags(inode);
2536 }
2537
2538 flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2539
2540 /*
2541 * For bigalloc file systems, we never free a partial cluster
2542 * at the beginning of the extent. Instead, we check to see if we
2543 * need to free it on a subsequent call to ext4_remove_blocks,
2544 * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
2545 */
2546 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2547 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2548
2549 /* reset the partial cluster if we've freed past it */
2550 if (partial->state != initial && partial->pclu != EXT4_B2C(sbi, pblk))
2551 partial->state = initial;
2552
2553 /*
2554 * If we've freed the entire extent but the beginning is not left
2555 * cluster aligned and is not marked as ineligible for freeing we
2556 * record the partial cluster at the beginning of the extent. It
2557 * wasn't freed by the preceding ext4_free_blocks() call, and we
2558 * need to look farther to the left to determine if it's to be freed
2559 * (not shared with another extent). Else, reset the partial
2560 * cluster - we're either done freeing or the beginning of the
2561 * extent is left cluster aligned.
2562 */
2563 if (EXT4_LBLK_COFF(sbi, from) && num == ee_len) {
2564 if (partial->state == initial) {
2565 partial->pclu = EXT4_B2C(sbi, pblk);
2566 partial->lblk = from;
2567 partial->state = tofree;
2568 }
2569 } else {
2570 partial->state = initial;
2571 }
2572
2573 return 0;
2574}
2575
2576/*
2577 * ext4_ext_rm_leaf() Removes the extents associated with the
2578 * blocks appearing between "start" and "end". Both "start"
2579 * and "end" must appear in the same extent or EIO is returned.
2580 *
2581 * @handle: The journal handle
2582 * @inode: The files inode
2583 * @path: The path to the leaf
2584 * @partial_cluster: The cluster which we'll have to free if all extents
2585 * has been released from it. However, if this value is
2586 * negative, it's a cluster just to the right of the
2587 * punched region and it must not be freed.
2588 * @start: The first block to remove
2589 * @end: The last block to remove
2590 */
2591static int
2592ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2593 struct ext4_ext_path *path,
2594 struct partial_cluster *partial,
2595 ext4_lblk_t start, ext4_lblk_t end)
2596{
2597 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2598 int err = 0, correct_index = 0;
2599 int depth = ext_depth(inode), credits, revoke_credits;
2600 struct ext4_extent_header *eh;
2601 ext4_lblk_t a, b;
2602 unsigned num;
2603 ext4_lblk_t ex_ee_block;
2604 unsigned short ex_ee_len;
2605 unsigned unwritten = 0;
2606 struct ext4_extent *ex;
2607 ext4_fsblk_t pblk;
2608
2609 /* the header must be checked already in ext4_ext_remove_space() */
2610 ext_debug(inode, "truncate since %u in leaf to %u\n", start, end);
2611 if (!path[depth].p_hdr)
2612 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2613 eh = path[depth].p_hdr;
2614 if (unlikely(path[depth].p_hdr == NULL)) {
2615 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2616 return -EFSCORRUPTED;
2617 }
2618 /* find where to start removing */
2619 ex = path[depth].p_ext;
2620 if (!ex)
2621 ex = EXT_LAST_EXTENT(eh);
2622
2623 ex_ee_block = le32_to_cpu(ex->ee_block);
2624 ex_ee_len = ext4_ext_get_actual_len(ex);
2625
2626 trace_ext4_ext_rm_leaf(inode, start, ex, partial);
2627
2628 while (ex >= EXT_FIRST_EXTENT(eh) &&
2629 ex_ee_block + ex_ee_len > start) {
2630
2631 if (ext4_ext_is_unwritten(ex))
2632 unwritten = 1;
2633 else
2634 unwritten = 0;
2635
2636 ext_debug(inode, "remove ext %u:[%d]%d\n", ex_ee_block,
2637 unwritten, ex_ee_len);
2638 path[depth].p_ext = ex;
2639
2640 a = max(ex_ee_block, start);
2641 b = min(ex_ee_block + ex_ee_len - 1, end);
2642
2643 ext_debug(inode, " border %u:%u\n", a, b);
2644
2645 /* If this extent is beyond the end of the hole, skip it */
2646 if (end < ex_ee_block) {
2647 /*
2648 * We're going to skip this extent and move to another,
2649 * so note that its first cluster is in use to avoid
2650 * freeing it when removing blocks. Eventually, the
2651 * right edge of the truncated/punched region will
2652 * be just to the left.
2653 */
2654 if (sbi->s_cluster_ratio > 1) {
2655 pblk = ext4_ext_pblock(ex);
2656 partial->pclu = EXT4_B2C(sbi, pblk);
2657 partial->state = nofree;
2658 }
2659 ex--;
2660 ex_ee_block = le32_to_cpu(ex->ee_block);
2661 ex_ee_len = ext4_ext_get_actual_len(ex);
2662 continue;
2663 } else if (b != ex_ee_block + ex_ee_len - 1) {
2664 EXT4_ERROR_INODE(inode,
2665 "can not handle truncate %u:%u "
2666 "on extent %u:%u",
2667 start, end, ex_ee_block,
2668 ex_ee_block + ex_ee_len - 1);
2669 err = -EFSCORRUPTED;
2670 goto out;
2671 } else if (a != ex_ee_block) {
2672 /* remove tail of the extent */
2673 num = a - ex_ee_block;
2674 } else {
2675 /* remove whole extent: excellent! */
2676 num = 0;
2677 }
2678 /*
2679 * 3 for leaf, sb, and inode plus 2 (bmap and group
2680 * descriptor) for each block group; assume two block
2681 * groups plus ex_ee_len/blocks_per_block_group for
2682 * the worst case
2683 */
2684 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2685 if (ex == EXT_FIRST_EXTENT(eh)) {
2686 correct_index = 1;
2687 credits += (ext_depth(inode)) + 1;
2688 }
2689 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2690 /*
2691 * We may end up freeing some index blocks and data from the
2692 * punched range. Note that partial clusters are accounted for
2693 * by ext4_free_data_revoke_credits().
2694 */
2695 revoke_credits =
2696 ext4_free_metadata_revoke_credits(inode->i_sb,
2697 ext_depth(inode)) +
2698 ext4_free_data_revoke_credits(inode, b - a + 1);
2699
2700 err = ext4_datasem_ensure_credits(handle, inode, credits,
2701 credits, revoke_credits);
2702 if (err) {
2703 if (err > 0)
2704 err = -EAGAIN;
2705 goto out;
2706 }
2707
2708 err = ext4_ext_get_access(handle, inode, path + depth);
2709 if (err)
2710 goto out;
2711
2712 err = ext4_remove_blocks(handle, inode, ex, partial, a, b);
2713 if (err)
2714 goto out;
2715
2716 if (num == 0)
2717 /* this extent is removed; mark slot entirely unused */
2718 ext4_ext_store_pblock(ex, 0);
2719
2720 ex->ee_len = cpu_to_le16(num);
2721 /*
2722 * Do not mark unwritten if all the blocks in the
2723 * extent have been removed.
2724 */
2725 if (unwritten && num)
2726 ext4_ext_mark_unwritten(ex);
2727 /*
2728 * If the extent was completely released,
2729 * we need to remove it from the leaf
2730 */
2731 if (num == 0) {
2732 if (end != EXT_MAX_BLOCKS - 1) {
2733 /*
2734 * For hole punching, we need to scoot all the
2735 * extents up when an extent is removed so that
2736 * we dont have blank extents in the middle
2737 */
2738 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2739 sizeof(struct ext4_extent));
2740
2741 /* Now get rid of the one at the end */
2742 memset(EXT_LAST_EXTENT(eh), 0,
2743 sizeof(struct ext4_extent));
2744 }
2745 le16_add_cpu(&eh->eh_entries, -1);
2746 }
2747
2748 err = ext4_ext_dirty(handle, inode, path + depth);
2749 if (err)
2750 goto out;
2751
2752 ext_debug(inode, "new extent: %u:%u:%llu\n", ex_ee_block, num,
2753 ext4_ext_pblock(ex));
2754 ex--;
2755 ex_ee_block = le32_to_cpu(ex->ee_block);
2756 ex_ee_len = ext4_ext_get_actual_len(ex);
2757 }
2758
2759 if (correct_index && eh->eh_entries)
2760 err = ext4_ext_correct_indexes(handle, inode, path);
2761
2762 /*
2763 * If there's a partial cluster and at least one extent remains in
2764 * the leaf, free the partial cluster if it isn't shared with the
2765 * current extent. If it is shared with the current extent
2766 * we reset the partial cluster because we've reached the start of the
2767 * truncated/punched region and we're done removing blocks.
2768 */
2769 if (partial->state == tofree && ex >= EXT_FIRST_EXTENT(eh)) {
2770 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
2771 if (partial->pclu != EXT4_B2C(sbi, pblk)) {
2772 int flags = get_default_free_blocks_flags(inode);
2773
2774 if (ext4_is_pending(inode, partial->lblk))
2775 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
2776 ext4_free_blocks(handle, inode, NULL,
2777 EXT4_C2B(sbi, partial->pclu),
2778 sbi->s_cluster_ratio, flags);
2779 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
2780 ext4_rereserve_cluster(inode, partial->lblk);
2781 }
2782 partial->state = initial;
2783 }
2784
2785 /* if this leaf is free, then we should
2786 * remove it from index block above */
2787 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2788 err = ext4_ext_rm_idx(handle, inode, path, depth);
2789
2790out:
2791 return err;
2792}
2793
2794/*
2795 * ext4_ext_more_to_rm:
2796 * returns 1 if current index has to be freed (even partial)
2797 */
2798static int
2799ext4_ext_more_to_rm(struct ext4_ext_path *path)
2800{
2801 BUG_ON(path->p_idx == NULL);
2802
2803 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2804 return 0;
2805
2806 /*
2807 * if truncate on deeper level happened, it wasn't partial,
2808 * so we have to consider current index for truncation
2809 */
2810 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2811 return 0;
2812 return 1;
2813}
2814
2815int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2816 ext4_lblk_t end)
2817{
2818 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2819 int depth = ext_depth(inode);
2820 struct ext4_ext_path *path = NULL;
2821 struct partial_cluster partial;
2822 handle_t *handle;
2823 int i = 0, err = 0;
2824
2825 partial.pclu = 0;
2826 partial.lblk = 0;
2827 partial.state = initial;
2828
2829 ext_debug(inode, "truncate since %u to %u\n", start, end);
2830
2831 /* probably first extent we're gonna free will be last in block */
2832 handle = ext4_journal_start_with_revoke(inode, EXT4_HT_TRUNCATE,
2833 depth + 1,
2834 ext4_free_metadata_revoke_credits(inode->i_sb, depth));
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,
2855 EXT4_EX_NOCACHE | EXT4_EX_NOFAIL);
2856 if (IS_ERR(path)) {
2857 ext4_journal_stop(handle);
2858 return PTR_ERR(path);
2859 }
2860 depth = ext_depth(inode);
2861 /* Leaf not may not exist only if inode has no blocks at all */
2862 ex = path[depth].p_ext;
2863 if (!ex) {
2864 if (depth) {
2865 EXT4_ERROR_INODE(inode,
2866 "path[%d].p_hdr == NULL",
2867 depth);
2868 err = -EFSCORRUPTED;
2869 }
2870 goto out;
2871 }
2872
2873 ee_block = le32_to_cpu(ex->ee_block);
2874 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
2875
2876 /*
2877 * See if the last block is inside the extent, if so split
2878 * the extent at 'end' block so we can easily remove the
2879 * tail of the first part of the split extent in
2880 * ext4_ext_rm_leaf().
2881 */
2882 if (end >= ee_block && end < ex_end) {
2883
2884 /*
2885 * If we're going to split the extent, note that
2886 * the cluster containing the block after 'end' is
2887 * in use to avoid freeing it when removing blocks.
2888 */
2889 if (sbi->s_cluster_ratio > 1) {
2890 pblk = ext4_ext_pblock(ex) + end - ee_block + 1;
2891 partial.pclu = EXT4_B2C(sbi, pblk);
2892 partial.state = nofree;
2893 }
2894
2895 /*
2896 * Split the extent in two so that 'end' is the last
2897 * block in the first new extent. Also we should not
2898 * fail removing space due to ENOSPC so try to use
2899 * reserved block if that happens.
2900 */
2901 path = ext4_force_split_extent_at(handle, inode, path,
2902 end + 1, 1);
2903 if (IS_ERR(path)) {
2904 err = PTR_ERR(path);
2905 goto out;
2906 }
2907 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end &&
2908 partial.state == initial) {
2909 /*
2910 * If we're punching, there's an extent to the right.
2911 * If the partial cluster hasn't been set, set it to
2912 * that extent's first cluster and its state to nofree
2913 * so it won't be freed should it contain blocks to be
2914 * removed. If it's already set (tofree/nofree), we're
2915 * retrying and keep the original partial cluster info
2916 * so a cluster marked tofree as a result of earlier
2917 * extent removal is not lost.
2918 */
2919 lblk = ex_end + 1;
2920 err = ext4_ext_search_right(inode, path, &lblk, &pblk,
2921 NULL);
2922 if (err < 0)
2923 goto out;
2924 if (pblk) {
2925 partial.pclu = EXT4_B2C(sbi, pblk);
2926 partial.state = nofree;
2927 }
2928 }
2929 }
2930 /*
2931 * We start scanning from right side, freeing all the blocks
2932 * after i_size and walking into the tree depth-wise.
2933 */
2934 depth = ext_depth(inode);
2935 if (path) {
2936 int k = i = depth;
2937 while (--k > 0)
2938 path[k].p_block =
2939 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2940 } else {
2941 path = kcalloc(depth + 1, sizeof(struct ext4_ext_path),
2942 GFP_NOFS | __GFP_NOFAIL);
2943 if (path == NULL) {
2944 ext4_journal_stop(handle);
2945 return -ENOMEM;
2946 }
2947 path[0].p_maxdepth = path[0].p_depth = depth;
2948 path[0].p_hdr = ext_inode_hdr(inode);
2949 i = 0;
2950
2951 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2952 err = -EFSCORRUPTED;
2953 goto out;
2954 }
2955 }
2956 err = 0;
2957
2958 while (i >= 0 && err == 0) {
2959 if (i == depth) {
2960 /* this is leaf block */
2961 err = ext4_ext_rm_leaf(handle, inode, path,
2962 &partial, start, end);
2963 /* root level has p_bh == NULL, brelse() eats this */
2964 ext4_ext_path_brelse(path + i);
2965 i--;
2966 continue;
2967 }
2968
2969 /* this is index block */
2970 if (!path[i].p_hdr) {
2971 ext_debug(inode, "initialize header\n");
2972 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2973 }
2974
2975 if (!path[i].p_idx) {
2976 /* this level hasn't been touched yet */
2977 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2978 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2979 ext_debug(inode, "init index ptr: hdr 0x%p, num %d\n",
2980 path[i].p_hdr,
2981 le16_to_cpu(path[i].p_hdr->eh_entries));
2982 } else {
2983 /* we were already here, see at next index */
2984 path[i].p_idx--;
2985 }
2986
2987 ext_debug(inode, "level %d - index, first 0x%p, cur 0x%p\n",
2988 i, EXT_FIRST_INDEX(path[i].p_hdr),
2989 path[i].p_idx);
2990 if (ext4_ext_more_to_rm(path + i)) {
2991 struct buffer_head *bh;
2992 /* go to the next level */
2993 ext_debug(inode, "move to level %d (block %llu)\n",
2994 i + 1, ext4_idx_pblock(path[i].p_idx));
2995 memset(path + i + 1, 0, sizeof(*path));
2996 bh = read_extent_tree_block(inode, path[i].p_idx,
2997 depth - i - 1,
2998 EXT4_EX_NOCACHE);
2999 if (IS_ERR(bh)) {
3000 /* should we reset i_size? */
3001 err = PTR_ERR(bh);
3002 break;
3003 }
3004 /* Yield here to deal with large extent trees.
3005 * Should be a no-op if we did IO above. */
3006 cond_resched();
3007 if (WARN_ON(i + 1 > depth)) {
3008 err = -EFSCORRUPTED;
3009 break;
3010 }
3011 path[i + 1].p_bh = bh;
3012
3013 /* save actual number of indexes since this
3014 * number is changed at the next iteration */
3015 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
3016 i++;
3017 } else {
3018 /* we finished processing this index, go up */
3019 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
3020 /* index is empty, remove it;
3021 * handle must be already prepared by the
3022 * truncatei_leaf() */
3023 err = ext4_ext_rm_idx(handle, inode, path, i);
3024 }
3025 /* root level has p_bh == NULL, brelse() eats this */
3026 ext4_ext_path_brelse(path + i);
3027 i--;
3028 ext_debug(inode, "return to level %d\n", i);
3029 }
3030 }
3031
3032 trace_ext4_ext_remove_space_done(inode, start, end, depth, &partial,
3033 path->p_hdr->eh_entries);
3034
3035 /*
3036 * if there's a partial cluster and we have removed the first extent
3037 * in the file, then we also free the partial cluster, if any
3038 */
3039 if (partial.state == tofree && err == 0) {
3040 int flags = get_default_free_blocks_flags(inode);
3041
3042 if (ext4_is_pending(inode, partial.lblk))
3043 flags |= EXT4_FREE_BLOCKS_RERESERVE_CLUSTER;
3044 ext4_free_blocks(handle, inode, NULL,
3045 EXT4_C2B(sbi, partial.pclu),
3046 sbi->s_cluster_ratio, flags);
3047 if (flags & EXT4_FREE_BLOCKS_RERESERVE_CLUSTER)
3048 ext4_rereserve_cluster(inode, partial.lblk);
3049 partial.state = initial;
3050 }
3051
3052 /* TODO: flexible tree reduction should be here */
3053 if (path->p_hdr->eh_entries == 0) {
3054 /*
3055 * truncate to zero freed all the tree,
3056 * so we need to correct eh_depth
3057 */
3058 err = ext4_ext_get_access(handle, inode, path);
3059 if (err == 0) {
3060 ext_inode_hdr(inode)->eh_depth = 0;
3061 ext_inode_hdr(inode)->eh_max =
3062 cpu_to_le16(ext4_ext_space_root(inode, 0));
3063 err = ext4_ext_dirty(handle, inode, path);
3064 }
3065 }
3066out:
3067 ext4_free_ext_path(path);
3068 path = NULL;
3069 if (err == -EAGAIN)
3070 goto again;
3071 ext4_journal_stop(handle);
3072
3073 return err;
3074}
3075
3076/*
3077 * called at mount time
3078 */
3079void ext4_ext_init(struct super_block *sb)
3080{
3081 /*
3082 * possible initialization would be here
3083 */
3084
3085 if (ext4_has_feature_extents(sb)) {
3086#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
3087 printk(KERN_INFO "EXT4-fs: file extents enabled"
3088#ifdef AGGRESSIVE_TEST
3089 ", aggressive tests"
3090#endif
3091#ifdef CHECK_BINSEARCH
3092 ", check binsearch"
3093#endif
3094#ifdef EXTENTS_STATS
3095 ", stats"
3096#endif
3097 "\n");
3098#endif
3099#ifdef EXTENTS_STATS
3100 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3101 EXT4_SB(sb)->s_ext_min = 1 << 30;
3102 EXT4_SB(sb)->s_ext_max = 0;
3103#endif
3104 }
3105}
3106
3107/*
3108 * called at umount time
3109 */
3110void ext4_ext_release(struct super_block *sb)
3111{
3112 if (!ext4_has_feature_extents(sb))
3113 return;
3114
3115#ifdef EXTENTS_STATS
3116 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3117 struct ext4_sb_info *sbi = EXT4_SB(sb);
3118 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3119 sbi->s_ext_blocks, sbi->s_ext_extents,
3120 sbi->s_ext_blocks / sbi->s_ext_extents);
3121 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3122 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3123 }
3124#endif
3125}
3126
3127static void ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3128{
3129 ext4_lblk_t ee_block;
3130 ext4_fsblk_t ee_pblock;
3131 unsigned int ee_len;
3132
3133 ee_block = le32_to_cpu(ex->ee_block);
3134 ee_len = ext4_ext_get_actual_len(ex);
3135 ee_pblock = ext4_ext_pblock(ex);
3136
3137 if (ee_len == 0)
3138 return;
3139
3140 ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3141 EXTENT_STATUS_WRITTEN, false);
3142}
3143
3144/* FIXME!! we need to try to merge to left or right after zero-out */
3145static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3146{
3147 ext4_fsblk_t ee_pblock;
3148 unsigned int ee_len;
3149
3150 ee_len = ext4_ext_get_actual_len(ex);
3151 ee_pblock = ext4_ext_pblock(ex);
3152 return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock,
3153 ee_len);
3154}
3155
3156/*
3157 * ext4_split_extent_at() splits an extent at given block.
3158 *
3159 * @handle: the journal handle
3160 * @inode: the file inode
3161 * @path: the path to the extent
3162 * @split: the logical block where the extent is splitted.
3163 * @split_flags: indicates if the extent could be zeroout if split fails, and
3164 * the states(init or unwritten) of new extents.
3165 * @flags: flags used to insert new extent to extent tree.
3166 *
3167 *
3168 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3169 * of which are determined by split_flag.
3170 *
3171 * There are two cases:
3172 * a> the extent are splitted into two extent.
3173 * b> split is not needed, and just mark the extent.
3174 *
3175 * Return an extent path pointer on success, or an error pointer on failure.
3176 */
3177static struct ext4_ext_path *ext4_split_extent_at(handle_t *handle,
3178 struct inode *inode,
3179 struct ext4_ext_path *path,
3180 ext4_lblk_t split,
3181 int split_flag, int flags)
3182{
3183 ext4_fsblk_t newblock;
3184 ext4_lblk_t ee_block;
3185 struct ext4_extent *ex, newex, orig_ex, zero_ex;
3186 struct ext4_extent *ex2 = NULL;
3187 unsigned int ee_len, depth;
3188 int err = 0;
3189
3190 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3191 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3192
3193 ext_debug(inode, "logical block %llu\n", (unsigned long long)split);
3194
3195 ext4_ext_show_leaf(inode, path);
3196
3197 depth = ext_depth(inode);
3198 ex = path[depth].p_ext;
3199 ee_block = le32_to_cpu(ex->ee_block);
3200 ee_len = ext4_ext_get_actual_len(ex);
3201 newblock = split - ee_block + ext4_ext_pblock(ex);
3202
3203 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3204 BUG_ON(!ext4_ext_is_unwritten(ex) &&
3205 split_flag & (EXT4_EXT_MAY_ZEROOUT |
3206 EXT4_EXT_MARK_UNWRIT1 |
3207 EXT4_EXT_MARK_UNWRIT2));
3208
3209 err = ext4_ext_get_access(handle, inode, path + depth);
3210 if (err)
3211 goto out;
3212
3213 if (split == ee_block) {
3214 /*
3215 * case b: block @split is the block that the extent begins with
3216 * then we just change the state of the extent, and splitting
3217 * is not needed.
3218 */
3219 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3220 ext4_ext_mark_unwritten(ex);
3221 else
3222 ext4_ext_mark_initialized(ex);
3223
3224 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3225 ext4_ext_try_to_merge(handle, inode, path, ex);
3226
3227 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3228 goto out;
3229 }
3230
3231 /* case a */
3232 memcpy(&orig_ex, ex, sizeof(orig_ex));
3233 ex->ee_len = cpu_to_le16(split - ee_block);
3234 if (split_flag & EXT4_EXT_MARK_UNWRIT1)
3235 ext4_ext_mark_unwritten(ex);
3236
3237 /*
3238 * path may lead to new leaf, not to original leaf any more
3239 * after ext4_ext_insert_extent() returns,
3240 */
3241 err = ext4_ext_dirty(handle, inode, path + depth);
3242 if (err)
3243 goto fix_extent_len;
3244
3245 ex2 = &newex;
3246 ex2->ee_block = cpu_to_le32(split);
3247 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
3248 ext4_ext_store_pblock(ex2, newblock);
3249 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3250 ext4_ext_mark_unwritten(ex2);
3251
3252 path = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
3253 if (!IS_ERR(path))
3254 goto out;
3255
3256 err = PTR_ERR(path);
3257 if (err != -ENOSPC && err != -EDQUOT && err != -ENOMEM)
3258 return path;
3259
3260 /*
3261 * Get a new path to try to zeroout or fix the extent length.
3262 * Using EXT4_EX_NOFAIL guarantees that ext4_find_extent()
3263 * will not return -ENOMEM, otherwise -ENOMEM will cause a
3264 * retry in do_writepages(), and a WARN_ON may be triggered
3265 * in ext4_da_update_reserve_space() due to an incorrect
3266 * ee_len causing the i_reserved_data_blocks exception.
3267 */
3268 path = ext4_find_extent(inode, ee_block, NULL, flags | EXT4_EX_NOFAIL);
3269 if (IS_ERR(path)) {
3270 EXT4_ERROR_INODE(inode, "Failed split extent on %u, err %ld",
3271 split, PTR_ERR(path));
3272 return path;
3273 }
3274 depth = ext_depth(inode);
3275 ex = path[depth].p_ext;
3276
3277 if (EXT4_EXT_MAY_ZEROOUT & split_flag) {
3278 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3279 if (split_flag & EXT4_EXT_DATA_VALID1) {
3280 err = ext4_ext_zeroout(inode, ex2);
3281 zero_ex.ee_block = ex2->ee_block;
3282 zero_ex.ee_len = cpu_to_le16(
3283 ext4_ext_get_actual_len(ex2));
3284 ext4_ext_store_pblock(&zero_ex,
3285 ext4_ext_pblock(ex2));
3286 } else {
3287 err = ext4_ext_zeroout(inode, ex);
3288 zero_ex.ee_block = ex->ee_block;
3289 zero_ex.ee_len = cpu_to_le16(
3290 ext4_ext_get_actual_len(ex));
3291 ext4_ext_store_pblock(&zero_ex,
3292 ext4_ext_pblock(ex));
3293 }
3294 } else {
3295 err = ext4_ext_zeroout(inode, &orig_ex);
3296 zero_ex.ee_block = orig_ex.ee_block;
3297 zero_ex.ee_len = cpu_to_le16(
3298 ext4_ext_get_actual_len(&orig_ex));
3299 ext4_ext_store_pblock(&zero_ex,
3300 ext4_ext_pblock(&orig_ex));
3301 }
3302
3303 if (!err) {
3304 /* update the extent length and mark as initialized */
3305 ex->ee_len = cpu_to_le16(ee_len);
3306 ext4_ext_try_to_merge(handle, inode, path, ex);
3307 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3308 if (!err)
3309 /* update extent status tree */
3310 ext4_zeroout_es(inode, &zero_ex);
3311 /* If we failed at this point, we don't know in which
3312 * state the extent tree exactly is so don't try to fix
3313 * length of the original extent as it may do even more
3314 * damage.
3315 */
3316 goto out;
3317 }
3318 }
3319
3320fix_extent_len:
3321 ex->ee_len = orig_ex.ee_len;
3322 /*
3323 * Ignore ext4_ext_dirty return value since we are already in error path
3324 * and err is a non-zero error code.
3325 */
3326 ext4_ext_dirty(handle, inode, path + path->p_depth);
3327out:
3328 if (err) {
3329 ext4_free_ext_path(path);
3330 path = ERR_PTR(err);
3331 }
3332 ext4_ext_show_leaf(inode, path);
3333 return path;
3334}
3335
3336/*
3337 * ext4_split_extent() splits an extent and mark extent which is covered
3338 * by @map as split_flags indicates
3339 *
3340 * It may result in splitting the extent into multiple extents (up to three)
3341 * There are three possibilities:
3342 * a> There is no split required
3343 * b> Splits in two extents: Split is happening at either end of the extent
3344 * c> Splits in three extents: Somone is splitting in middle of the extent
3345 *
3346 */
3347static struct ext4_ext_path *ext4_split_extent(handle_t *handle,
3348 struct inode *inode,
3349 struct ext4_ext_path *path,
3350 struct ext4_map_blocks *map,
3351 int split_flag, int flags,
3352 unsigned int *allocated)
3353{
3354 ext4_lblk_t ee_block;
3355 struct ext4_extent *ex;
3356 unsigned int ee_len, depth;
3357 int unwritten;
3358 int split_flag1, flags1;
3359
3360 depth = ext_depth(inode);
3361 ex = path[depth].p_ext;
3362 ee_block = le32_to_cpu(ex->ee_block);
3363 ee_len = ext4_ext_get_actual_len(ex);
3364 unwritten = ext4_ext_is_unwritten(ex);
3365
3366 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3367 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3368 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3369 if (unwritten)
3370 split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
3371 EXT4_EXT_MARK_UNWRIT2;
3372 if (split_flag & EXT4_EXT_DATA_VALID2)
3373 split_flag1 |= EXT4_EXT_DATA_VALID1;
3374 path = ext4_split_extent_at(handle, inode, path,
3375 map->m_lblk + map->m_len, split_flag1, flags1);
3376 if (IS_ERR(path))
3377 return path;
3378 /*
3379 * Update path is required because previous ext4_split_extent_at
3380 * may result in split of original leaf or extent zeroout.
3381 */
3382 path = ext4_find_extent(inode, map->m_lblk, path, flags);
3383 if (IS_ERR(path))
3384 return path;
3385 depth = ext_depth(inode);
3386 ex = path[depth].p_ext;
3387 if (!ex) {
3388 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3389 (unsigned long) map->m_lblk);
3390 ext4_free_ext_path(path);
3391 return ERR_PTR(-EFSCORRUPTED);
3392 }
3393 unwritten = ext4_ext_is_unwritten(ex);
3394 }
3395
3396 if (map->m_lblk >= ee_block) {
3397 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3398 if (unwritten) {
3399 split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
3400 split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3401 EXT4_EXT_MARK_UNWRIT2);
3402 }
3403 path = ext4_split_extent_at(handle, inode, path,
3404 map->m_lblk, split_flag1, flags);
3405 if (IS_ERR(path))
3406 return path;
3407 }
3408
3409 if (allocated) {
3410 if (map->m_lblk + map->m_len > ee_block + ee_len)
3411 *allocated = ee_len - (map->m_lblk - ee_block);
3412 else
3413 *allocated = map->m_len;
3414 }
3415 ext4_ext_show_leaf(inode, path);
3416 return path;
3417}
3418
3419/*
3420 * This function is called by ext4_ext_map_blocks() if someone tries to write
3421 * to an unwritten extent. It may result in splitting the unwritten
3422 * extent into multiple extents (up to three - one initialized and two
3423 * unwritten).
3424 * There are three possibilities:
3425 * a> There is no split required: Entire extent should be initialized
3426 * b> Splits in two extents: Write is happening at either end of the extent
3427 * c> Splits in three extents: Somone is writing in middle of the extent
3428 *
3429 * Pre-conditions:
3430 * - The extent pointed to by 'path' is unwritten.
3431 * - The extent pointed to by 'path' contains a superset
3432 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3433 *
3434 * Post-conditions on success:
3435 * - the returned value is the number of blocks beyond map->l_lblk
3436 * that are allocated and initialized.
3437 * It is guaranteed to be >= map->m_len.
3438 */
3439static struct ext4_ext_path *
3440ext4_ext_convert_to_initialized(handle_t *handle, struct inode *inode,
3441 struct ext4_map_blocks *map, struct ext4_ext_path *path,
3442 int flags, unsigned int *allocated)
3443{
3444 struct ext4_sb_info *sbi;
3445 struct ext4_extent_header *eh;
3446 struct ext4_map_blocks split_map;
3447 struct ext4_extent zero_ex1, zero_ex2;
3448 struct ext4_extent *ex, *abut_ex;
3449 ext4_lblk_t ee_block, eof_block;
3450 unsigned int ee_len, depth, map_len = map->m_len;
3451 int err = 0;
3452 int split_flag = EXT4_EXT_DATA_VALID2;
3453 unsigned int max_zeroout = 0;
3454
3455 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3456 (unsigned long long)map->m_lblk, map_len);
3457
3458 sbi = EXT4_SB(inode->i_sb);
3459 eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1)
3460 >> inode->i_sb->s_blocksize_bits;
3461 if (eof_block < map->m_lblk + map_len)
3462 eof_block = map->m_lblk + map_len;
3463
3464 depth = ext_depth(inode);
3465 eh = path[depth].p_hdr;
3466 ex = path[depth].p_ext;
3467 ee_block = le32_to_cpu(ex->ee_block);
3468 ee_len = ext4_ext_get_actual_len(ex);
3469 zero_ex1.ee_len = 0;
3470 zero_ex2.ee_len = 0;
3471
3472 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3473
3474 /* Pre-conditions */
3475 BUG_ON(!ext4_ext_is_unwritten(ex));
3476 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3477
3478 /*
3479 * Attempt to transfer newly initialized blocks from the currently
3480 * unwritten extent to its neighbor. This is much cheaper
3481 * than an insertion followed by a merge as those involve costly
3482 * memmove() calls. Transferring to the left is the common case in
3483 * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3484 * followed by append writes.
3485 *
3486 * Limitations of the current logic:
3487 * - L1: we do not deal with writes covering the whole extent.
3488 * This would require removing the extent if the transfer
3489 * is possible.
3490 * - L2: we only attempt to merge with an extent stored in the
3491 * same extent tree node.
3492 */
3493 *allocated = 0;
3494 if ((map->m_lblk == ee_block) &&
3495 /* See if we can merge left */
3496 (map_len < ee_len) && /*L1*/
3497 (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/
3498 ext4_lblk_t prev_lblk;
3499 ext4_fsblk_t prev_pblk, ee_pblk;
3500 unsigned int prev_len;
3501
3502 abut_ex = ex - 1;
3503 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3504 prev_len = ext4_ext_get_actual_len(abut_ex);
3505 prev_pblk = ext4_ext_pblock(abut_ex);
3506 ee_pblk = ext4_ext_pblock(ex);
3507
3508 /*
3509 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3510 * upon those conditions:
3511 * - C1: abut_ex is initialized,
3512 * - C2: abut_ex is logically abutting ex,
3513 * - C3: abut_ex is physically abutting ex,
3514 * - C4: abut_ex can receive the additional blocks without
3515 * overflowing the (initialized) length limit.
3516 */
3517 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3518 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3519 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3520 (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3521 err = ext4_ext_get_access(handle, inode, path + depth);
3522 if (err)
3523 goto errout;
3524
3525 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3526 map, ex, abut_ex);
3527
3528 /* Shift the start of ex by 'map_len' blocks */
3529 ex->ee_block = cpu_to_le32(ee_block + map_len);
3530 ext4_ext_store_pblock(ex, ee_pblk + map_len);
3531 ex->ee_len = cpu_to_le16(ee_len - map_len);
3532 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3533
3534 /* Extend abut_ex by 'map_len' blocks */
3535 abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3536
3537 /* Result: number of initialized blocks past m_lblk */
3538 *allocated = map_len;
3539 }
3540 } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3541 (map_len < ee_len) && /*L1*/
3542 ex < EXT_LAST_EXTENT(eh)) { /*L2*/
3543 /* See if we can merge right */
3544 ext4_lblk_t next_lblk;
3545 ext4_fsblk_t next_pblk, ee_pblk;
3546 unsigned int next_len;
3547
3548 abut_ex = ex + 1;
3549 next_lblk = le32_to_cpu(abut_ex->ee_block);
3550 next_len = ext4_ext_get_actual_len(abut_ex);
3551 next_pblk = ext4_ext_pblock(abut_ex);
3552 ee_pblk = ext4_ext_pblock(ex);
3553
3554 /*
3555 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3556 * upon those conditions:
3557 * - C1: abut_ex is initialized,
3558 * - C2: abut_ex is logically abutting ex,
3559 * - C3: abut_ex is physically abutting ex,
3560 * - C4: abut_ex can receive the additional blocks without
3561 * overflowing the (initialized) length limit.
3562 */
3563 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3564 ((map->m_lblk + map_len) == next_lblk) && /*C2*/
3565 ((ee_pblk + ee_len) == next_pblk) && /*C3*/
3566 (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3567 err = ext4_ext_get_access(handle, inode, path + depth);
3568 if (err)
3569 goto errout;
3570
3571 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3572 map, ex, abut_ex);
3573
3574 /* Shift the start of abut_ex by 'map_len' blocks */
3575 abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3576 ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3577 ex->ee_len = cpu_to_le16(ee_len - map_len);
3578 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3579
3580 /* Extend abut_ex by 'map_len' blocks */
3581 abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3582
3583 /* Result: number of initialized blocks past m_lblk */
3584 *allocated = map_len;
3585 }
3586 }
3587 if (*allocated) {
3588 /* Mark the block containing both extents as dirty */
3589 err = ext4_ext_dirty(handle, inode, path + depth);
3590
3591 /* Update path to point to the right extent */
3592 path[depth].p_ext = abut_ex;
3593 if (err)
3594 goto errout;
3595 goto out;
3596 } else
3597 *allocated = ee_len - (map->m_lblk - ee_block);
3598
3599 WARN_ON(map->m_lblk < ee_block);
3600 /*
3601 * It is safe to convert extent to initialized via explicit
3602 * zeroout only if extent is fully inside i_size or new_size.
3603 */
3604 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3605
3606 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3607 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3608 (inode->i_sb->s_blocksize_bits - 10);
3609
3610 /*
3611 * five cases:
3612 * 1. split the extent into three extents.
3613 * 2. split the extent into two extents, zeroout the head of the first
3614 * extent.
3615 * 3. split the extent into two extents, zeroout the tail of the second
3616 * extent.
3617 * 4. split the extent into two extents with out zeroout.
3618 * 5. no splitting needed, just possibly zeroout the head and / or the
3619 * tail of the extent.
3620 */
3621 split_map.m_lblk = map->m_lblk;
3622 split_map.m_len = map->m_len;
3623
3624 if (max_zeroout && (*allocated > split_map.m_len)) {
3625 if (*allocated <= max_zeroout) {
3626 /* case 3 or 5 */
3627 zero_ex1.ee_block =
3628 cpu_to_le32(split_map.m_lblk +
3629 split_map.m_len);
3630 zero_ex1.ee_len =
3631 cpu_to_le16(*allocated - split_map.m_len);
3632 ext4_ext_store_pblock(&zero_ex1,
3633 ext4_ext_pblock(ex) + split_map.m_lblk +
3634 split_map.m_len - ee_block);
3635 err = ext4_ext_zeroout(inode, &zero_ex1);
3636 if (err)
3637 goto fallback;
3638 split_map.m_len = *allocated;
3639 }
3640 if (split_map.m_lblk - ee_block + split_map.m_len <
3641 max_zeroout) {
3642 /* case 2 or 5 */
3643 if (split_map.m_lblk != ee_block) {
3644 zero_ex2.ee_block = ex->ee_block;
3645 zero_ex2.ee_len = cpu_to_le16(split_map.m_lblk -
3646 ee_block);
3647 ext4_ext_store_pblock(&zero_ex2,
3648 ext4_ext_pblock(ex));
3649 err = ext4_ext_zeroout(inode, &zero_ex2);
3650 if (err)
3651 goto fallback;
3652 }
3653
3654 split_map.m_len += split_map.m_lblk - ee_block;
3655 split_map.m_lblk = ee_block;
3656 *allocated = map->m_len;
3657 }
3658 }
3659
3660fallback:
3661 path = ext4_split_extent(handle, inode, path, &split_map, split_flag,
3662 flags, NULL);
3663 if (IS_ERR(path))
3664 return path;
3665out:
3666 /* If we have gotten a failure, don't zero out status tree */
3667 ext4_zeroout_es(inode, &zero_ex1);
3668 ext4_zeroout_es(inode, &zero_ex2);
3669 return path;
3670
3671errout:
3672 ext4_free_ext_path(path);
3673 return ERR_PTR(err);
3674}
3675
3676/*
3677 * This function is called by ext4_ext_map_blocks() from
3678 * ext4_get_blocks_dio_write() when DIO to write
3679 * to an unwritten extent.
3680 *
3681 * Writing to an unwritten extent may result in splitting the unwritten
3682 * extent into multiple initialized/unwritten extents (up to three)
3683 * There are three possibilities:
3684 * a> There is no split required: Entire extent should be unwritten
3685 * b> Splits in two extents: Write is happening at either end of the extent
3686 * c> Splits in three extents: Somone is writing in middle of the extent
3687 *
3688 * This works the same way in the case of initialized -> unwritten conversion.
3689 *
3690 * One of more index blocks maybe needed if the extent tree grow after
3691 * the unwritten extent split. To prevent ENOSPC occur at the IO
3692 * complete, we need to split the unwritten extent before DIO submit
3693 * the IO. The unwritten extent called at this time will be split
3694 * into three unwritten extent(at most). After IO complete, the part
3695 * being filled will be convert to initialized by the end_io callback function
3696 * via ext4_convert_unwritten_extents().
3697 *
3698 * The size of unwritten extent to be written is passed to the caller via the
3699 * allocated pointer. Return an extent path pointer on success, or an error
3700 * pointer on failure.
3701 */
3702static struct ext4_ext_path *ext4_split_convert_extents(handle_t *handle,
3703 struct inode *inode,
3704 struct ext4_map_blocks *map,
3705 struct ext4_ext_path *path,
3706 int flags, unsigned int *allocated)
3707{
3708 ext4_lblk_t eof_block;
3709 ext4_lblk_t ee_block;
3710 struct ext4_extent *ex;
3711 unsigned int ee_len;
3712 int split_flag = 0, depth;
3713
3714 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3715 (unsigned long long)map->m_lblk, map->m_len);
3716
3717 eof_block = (EXT4_I(inode)->i_disksize + inode->i_sb->s_blocksize - 1)
3718 >> inode->i_sb->s_blocksize_bits;
3719 if (eof_block < map->m_lblk + map->m_len)
3720 eof_block = map->m_lblk + map->m_len;
3721 /*
3722 * It is safe to convert extent to initialized via explicit
3723 * zeroout only if extent is fully inside i_size or new_size.
3724 */
3725 depth = ext_depth(inode);
3726 ex = path[depth].p_ext;
3727 ee_block = le32_to_cpu(ex->ee_block);
3728 ee_len = ext4_ext_get_actual_len(ex);
3729
3730 /* Convert to unwritten */
3731 if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
3732 split_flag |= EXT4_EXT_DATA_VALID1;
3733 /* Convert to initialized */
3734 } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
3735 split_flag |= ee_block + ee_len <= eof_block ?
3736 EXT4_EXT_MAY_ZEROOUT : 0;
3737 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
3738 }
3739 flags |= EXT4_GET_BLOCKS_PRE_IO;
3740 return ext4_split_extent(handle, inode, path, map, split_flag, flags,
3741 allocated);
3742}
3743
3744static struct ext4_ext_path *
3745ext4_convert_unwritten_extents_endio(handle_t *handle, struct inode *inode,
3746 struct ext4_map_blocks *map,
3747 struct ext4_ext_path *path)
3748{
3749 struct ext4_extent *ex;
3750 ext4_lblk_t ee_block;
3751 unsigned int ee_len;
3752 int depth;
3753 int err = 0;
3754
3755 depth = ext_depth(inode);
3756 ex = path[depth].p_ext;
3757 ee_block = le32_to_cpu(ex->ee_block);
3758 ee_len = ext4_ext_get_actual_len(ex);
3759
3760 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3761 (unsigned long long)ee_block, ee_len);
3762
3763 /* If extent is larger than requested it is a clear sign that we still
3764 * have some extent state machine issues left. So extent_split is still
3765 * required.
3766 * TODO: Once all related issues will be fixed this situation should be
3767 * illegal.
3768 */
3769 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3770#ifdef CONFIG_EXT4_DEBUG
3771 ext4_warning(inode->i_sb, "Inode (%ld) finished: extent logical block %llu,"
3772 " len %u; IO logical block %llu, len %u",
3773 inode->i_ino, (unsigned long long)ee_block, ee_len,
3774 (unsigned long long)map->m_lblk, map->m_len);
3775#endif
3776 path = ext4_split_convert_extents(handle, inode, map, path,
3777 EXT4_GET_BLOCKS_CONVERT, NULL);
3778 if (IS_ERR(path))
3779 return path;
3780
3781 path = ext4_find_extent(inode, map->m_lblk, path, 0);
3782 if (IS_ERR(path))
3783 return path;
3784 depth = ext_depth(inode);
3785 ex = path[depth].p_ext;
3786 }
3787
3788 err = ext4_ext_get_access(handle, inode, path + depth);
3789 if (err)
3790 goto errout;
3791 /* first mark the extent as initialized */
3792 ext4_ext_mark_initialized(ex);
3793
3794 /* note: ext4_ext_correct_indexes() isn't needed here because
3795 * borders are not changed
3796 */
3797 ext4_ext_try_to_merge(handle, inode, path, ex);
3798
3799 /* Mark modified extent as dirty */
3800 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3801 if (err)
3802 goto errout;
3803
3804 ext4_ext_show_leaf(inode, path);
3805 return path;
3806
3807errout:
3808 ext4_free_ext_path(path);
3809 return ERR_PTR(err);
3810}
3811
3812static struct ext4_ext_path *
3813convert_initialized_extent(handle_t *handle, struct inode *inode,
3814 struct ext4_map_blocks *map,
3815 struct ext4_ext_path *path,
3816 unsigned int *allocated)
3817{
3818 struct ext4_extent *ex;
3819 ext4_lblk_t ee_block;
3820 unsigned int ee_len;
3821 int depth;
3822 int err = 0;
3823
3824 /*
3825 * Make sure that the extent is no bigger than we support with
3826 * unwritten extent
3827 */
3828 if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
3829 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
3830
3831 depth = ext_depth(inode);
3832 ex = path[depth].p_ext;
3833 ee_block = le32_to_cpu(ex->ee_block);
3834 ee_len = ext4_ext_get_actual_len(ex);
3835
3836 ext_debug(inode, "logical block %llu, max_blocks %u\n",
3837 (unsigned long long)ee_block, ee_len);
3838
3839 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3840 path = ext4_split_convert_extents(handle, inode, map, path,
3841 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN, NULL);
3842 if (IS_ERR(path))
3843 return path;
3844
3845 path = ext4_find_extent(inode, map->m_lblk, path, 0);
3846 if (IS_ERR(path))
3847 return path;
3848 depth = ext_depth(inode);
3849 ex = path[depth].p_ext;
3850 if (!ex) {
3851 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3852 (unsigned long) map->m_lblk);
3853 err = -EFSCORRUPTED;
3854 goto errout;
3855 }
3856 }
3857
3858 err = ext4_ext_get_access(handle, inode, path + depth);
3859 if (err)
3860 goto errout;
3861 /* first mark the extent as unwritten */
3862 ext4_ext_mark_unwritten(ex);
3863
3864 /* note: ext4_ext_correct_indexes() isn't needed here because
3865 * borders are not changed
3866 */
3867 ext4_ext_try_to_merge(handle, inode, path, ex);
3868
3869 /* Mark modified extent as dirty */
3870 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3871 if (err)
3872 goto errout;
3873 ext4_ext_show_leaf(inode, path);
3874
3875 ext4_update_inode_fsync_trans(handle, inode, 1);
3876
3877 map->m_flags |= EXT4_MAP_UNWRITTEN;
3878 if (*allocated > map->m_len)
3879 *allocated = map->m_len;
3880 map->m_len = *allocated;
3881 return path;
3882
3883errout:
3884 ext4_free_ext_path(path);
3885 return ERR_PTR(err);
3886}
3887
3888static struct ext4_ext_path *
3889ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
3890 struct ext4_map_blocks *map,
3891 struct ext4_ext_path *path, int flags,
3892 unsigned int *allocated, ext4_fsblk_t newblock)
3893{
3894 int err = 0;
3895
3896 ext_debug(inode, "logical block %llu, max_blocks %u, flags 0x%x, allocated %u\n",
3897 (unsigned long long)map->m_lblk, map->m_len, flags,
3898 *allocated);
3899 ext4_ext_show_leaf(inode, path);
3900
3901 /*
3902 * When writing into unwritten space, we should not fail to
3903 * allocate metadata blocks for the new extent block if needed.
3904 */
3905 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
3906
3907 trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
3908 *allocated, newblock);
3909
3910 /* get_block() before submitting IO, split the extent */
3911 if (flags & EXT4_GET_BLOCKS_PRE_IO) {
3912 path = ext4_split_convert_extents(handle, inode, map, path,
3913 flags | EXT4_GET_BLOCKS_CONVERT, allocated);
3914 if (IS_ERR(path))
3915 return path;
3916 /*
3917 * shouldn't get a 0 allocated when splitting an extent unless
3918 * m_len is 0 (bug) or extent has been corrupted
3919 */
3920 if (unlikely(*allocated == 0)) {
3921 EXT4_ERROR_INODE(inode,
3922 "unexpected allocated == 0, m_len = %u",
3923 map->m_len);
3924 err = -EFSCORRUPTED;
3925 goto errout;
3926 }
3927 map->m_flags |= EXT4_MAP_UNWRITTEN;
3928 goto out;
3929 }
3930 /* IO end_io complete, convert the filled extent to written */
3931 if (flags & EXT4_GET_BLOCKS_CONVERT) {
3932 path = ext4_convert_unwritten_extents_endio(handle, inode,
3933 map, path);
3934 if (IS_ERR(path))
3935 return path;
3936 ext4_update_inode_fsync_trans(handle, inode, 1);
3937 goto map_out;
3938 }
3939 /* buffered IO cases */
3940 /*
3941 * repeat fallocate creation request
3942 * we already have an unwritten extent
3943 */
3944 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
3945 map->m_flags |= EXT4_MAP_UNWRITTEN;
3946 goto map_out;
3947 }
3948
3949 /* buffered READ or buffered write_begin() lookup */
3950 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3951 /*
3952 * We have blocks reserved already. We
3953 * return allocated blocks so that delalloc
3954 * won't do block reservation for us. But
3955 * the buffer head will be unmapped so that
3956 * a read from the block returns 0s.
3957 */
3958 map->m_flags |= EXT4_MAP_UNWRITTEN;
3959 goto out1;
3960 }
3961
3962 /*
3963 * Default case when (flags & EXT4_GET_BLOCKS_CREATE) == 1.
3964 * For buffered writes, at writepage time, etc. Convert a
3965 * discovered unwritten extent to written.
3966 */
3967 path = ext4_ext_convert_to_initialized(handle, inode, map, path,
3968 flags, allocated);
3969 if (IS_ERR(path))
3970 return path;
3971 ext4_update_inode_fsync_trans(handle, inode, 1);
3972 /*
3973 * shouldn't get a 0 allocated when converting an unwritten extent
3974 * unless m_len is 0 (bug) or extent has been corrupted
3975 */
3976 if (unlikely(*allocated == 0)) {
3977 EXT4_ERROR_INODE(inode, "unexpected allocated == 0, m_len = %u",
3978 map->m_len);
3979 err = -EFSCORRUPTED;
3980 goto errout;
3981 }
3982
3983out:
3984 map->m_flags |= EXT4_MAP_NEW;
3985map_out:
3986 map->m_flags |= EXT4_MAP_MAPPED;
3987out1:
3988 map->m_pblk = newblock;
3989 if (*allocated > map->m_len)
3990 *allocated = map->m_len;
3991 map->m_len = *allocated;
3992 ext4_ext_show_leaf(inode, path);
3993 return path;
3994
3995errout:
3996 ext4_free_ext_path(path);
3997 return ERR_PTR(err);
3998}
3999
4000/*
4001 * get_implied_cluster_alloc - check to see if the requested
4002 * allocation (in the map structure) overlaps with a cluster already
4003 * allocated in an extent.
4004 * @sb The filesystem superblock structure
4005 * @map The requested lblk->pblk mapping
4006 * @ex The extent structure which might contain an implied
4007 * cluster allocation
4008 *
4009 * This function is called by ext4_ext_map_blocks() after we failed to
4010 * find blocks that were already in the inode's extent tree. Hence,
4011 * we know that the beginning of the requested region cannot overlap
4012 * the extent from the inode's extent tree. There are three cases we
4013 * want to catch. The first is this case:
4014 *
4015 * |--- cluster # N--|
4016 * |--- extent ---| |---- requested region ---|
4017 * |==========|
4018 *
4019 * The second case that we need to test for is this one:
4020 *
4021 * |--------- cluster # N ----------------|
4022 * |--- requested region --| |------- extent ----|
4023 * |=======================|
4024 *
4025 * The third case is when the requested region lies between two extents
4026 * within the same cluster:
4027 * |------------- cluster # N-------------|
4028 * |----- ex -----| |---- ex_right ----|
4029 * |------ requested region ------|
4030 * |================|
4031 *
4032 * In each of the above cases, we need to set the map->m_pblk and
4033 * map->m_len so it corresponds to the return the extent labelled as
4034 * "|====|" from cluster #N, since it is already in use for data in
4035 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
4036 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
4037 * as a new "allocated" block region. Otherwise, we will return 0 and
4038 * ext4_ext_map_blocks() will then allocate one or more new clusters
4039 * by calling ext4_mb_new_blocks().
4040 */
4041static int get_implied_cluster_alloc(struct super_block *sb,
4042 struct ext4_map_blocks *map,
4043 struct ext4_extent *ex,
4044 struct ext4_ext_path *path)
4045{
4046 struct ext4_sb_info *sbi = EXT4_SB(sb);
4047 ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4048 ext4_lblk_t ex_cluster_start, ex_cluster_end;
4049 ext4_lblk_t rr_cluster_start;
4050 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4051 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4052 unsigned short ee_len = ext4_ext_get_actual_len(ex);
4053
4054 /* The extent passed in that we are trying to match */
4055 ex_cluster_start = EXT4_B2C(sbi, ee_block);
4056 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
4057
4058 /* The requested region passed into ext4_map_blocks() */
4059 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
4060
4061 if ((rr_cluster_start == ex_cluster_end) ||
4062 (rr_cluster_start == ex_cluster_start)) {
4063 if (rr_cluster_start == ex_cluster_end)
4064 ee_start += ee_len - 1;
4065 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
4066 map->m_len = min(map->m_len,
4067 (unsigned) sbi->s_cluster_ratio - c_offset);
4068 /*
4069 * Check for and handle this case:
4070 *
4071 * |--------- cluster # N-------------|
4072 * |------- extent ----|
4073 * |--- requested region ---|
4074 * |===========|
4075 */
4076
4077 if (map->m_lblk < ee_block)
4078 map->m_len = min(map->m_len, ee_block - map->m_lblk);
4079
4080 /*
4081 * Check for the case where there is already another allocated
4082 * block to the right of 'ex' but before the end of the cluster.
4083 *
4084 * |------------- cluster # N-------------|
4085 * |----- ex -----| |---- ex_right ----|
4086 * |------ requested region ------|
4087 * |================|
4088 */
4089 if (map->m_lblk > ee_block) {
4090 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4091 map->m_len = min(map->m_len, next - map->m_lblk);
4092 }
4093
4094 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4095 return 1;
4096 }
4097
4098 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4099 return 0;
4100}
4101
4102/*
4103 * Determine hole length around the given logical block, first try to
4104 * locate and expand the hole from the given @path, and then adjust it
4105 * if it's partially or completely converted to delayed extents, insert
4106 * it into the extent cache tree if it's indeed a hole, finally return
4107 * the length of the determined extent.
4108 */
4109static ext4_lblk_t ext4_ext_determine_insert_hole(struct inode *inode,
4110 struct ext4_ext_path *path,
4111 ext4_lblk_t lblk)
4112{
4113 ext4_lblk_t hole_start, len;
4114 struct extent_status es;
4115
4116 hole_start = lblk;
4117 len = ext4_ext_find_hole(inode, path, &hole_start);
4118again:
4119 ext4_es_find_extent_range(inode, &ext4_es_is_delayed, hole_start,
4120 hole_start + len - 1, &es);
4121 if (!es.es_len)
4122 goto insert_hole;
4123
4124 /*
4125 * There's a delalloc extent in the hole, handle it if the delalloc
4126 * extent is in front of, behind and straddle the queried range.
4127 */
4128 if (lblk >= es.es_lblk + es.es_len) {
4129 /*
4130 * The delalloc extent is in front of the queried range,
4131 * find again from the queried start block.
4132 */
4133 len -= lblk - hole_start;
4134 hole_start = lblk;
4135 goto again;
4136 } else if (in_range(lblk, es.es_lblk, es.es_len)) {
4137 /*
4138 * The delalloc extent containing lblk, it must have been
4139 * added after ext4_map_blocks() checked the extent status
4140 * tree so we are not holding i_rwsem and delalloc info is
4141 * only stabilized by i_data_sem we are going to release
4142 * soon. Don't modify the extent status tree and report
4143 * extent as a hole, just adjust the length to the delalloc
4144 * extent's after lblk.
4145 */
4146 len = es.es_lblk + es.es_len - lblk;
4147 return len;
4148 } else {
4149 /*
4150 * The delalloc extent is partially or completely behind
4151 * the queried range, update hole length until the
4152 * beginning of the delalloc extent.
4153 */
4154 len = min(es.es_lblk - hole_start, len);
4155 }
4156
4157insert_hole:
4158 /* Put just found gap into cache to speed up subsequent requests */
4159 ext_debug(inode, " -> %u:%u\n", hole_start, len);
4160 ext4_es_insert_extent(inode, hole_start, len, ~0,
4161 EXTENT_STATUS_HOLE, false);
4162
4163 /* Update hole_len to reflect hole size after lblk */
4164 if (hole_start != lblk)
4165 len -= lblk - hole_start;
4166
4167 return len;
4168}
4169
4170/*
4171 * Block allocation/map/preallocation routine for extents based files
4172 *
4173 *
4174 * Need to be called with
4175 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4176 * (ie, flags is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4177 *
4178 * return > 0, number of blocks already mapped/allocated
4179 * if flags doesn't contain EXT4_GET_BLOCKS_CREATE and these are pre-allocated blocks
4180 * buffer head is unmapped
4181 * otherwise blocks are mapped
4182 *
4183 * return = 0, if plain look up failed (blocks have not been allocated)
4184 * buffer head is unmapped
4185 *
4186 * return < 0, error case.
4187 */
4188int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4189 struct ext4_map_blocks *map, int flags)
4190{
4191 struct ext4_ext_path *path = NULL;
4192 struct ext4_extent newex, *ex, ex2;
4193 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4194 ext4_fsblk_t newblock = 0, pblk;
4195 int err = 0, depth;
4196 unsigned int allocated = 0, offset = 0;
4197 unsigned int allocated_clusters = 0;
4198 struct ext4_allocation_request ar;
4199 ext4_lblk_t cluster_offset;
4200
4201 ext_debug(inode, "blocks %u/%u requested\n", map->m_lblk, map->m_len);
4202 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4203
4204 /* find extent for this block */
4205 path = ext4_find_extent(inode, map->m_lblk, NULL, 0);
4206 if (IS_ERR(path)) {
4207 err = PTR_ERR(path);
4208 goto out;
4209 }
4210
4211 depth = ext_depth(inode);
4212
4213 /*
4214 * consistent leaf must not be empty;
4215 * this situation is possible, though, _during_ tree modification;
4216 * this is why assert can't be put in ext4_find_extent()
4217 */
4218 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4219 EXT4_ERROR_INODE(inode, "bad extent address "
4220 "lblock: %lu, depth: %d pblock %lld",
4221 (unsigned long) map->m_lblk, depth,
4222 path[depth].p_block);
4223 err = -EFSCORRUPTED;
4224 goto out;
4225 }
4226
4227 ex = path[depth].p_ext;
4228 if (ex) {
4229 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4230 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4231 unsigned short ee_len;
4232
4233
4234 /*
4235 * unwritten extents are treated as holes, except that
4236 * we split out initialized portions during a write.
4237 */
4238 ee_len = ext4_ext_get_actual_len(ex);
4239
4240 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4241
4242 /* if found extent covers block, simply return it */
4243 if (in_range(map->m_lblk, ee_block, ee_len)) {
4244 newblock = map->m_lblk - ee_block + ee_start;
4245 /* number of remaining blocks in the extent */
4246 allocated = ee_len - (map->m_lblk - ee_block);
4247 ext_debug(inode, "%u fit into %u:%d -> %llu\n",
4248 map->m_lblk, ee_block, ee_len, newblock);
4249
4250 /*
4251 * If the extent is initialized check whether the
4252 * caller wants to convert it to unwritten.
4253 */
4254 if ((!ext4_ext_is_unwritten(ex)) &&
4255 (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
4256 path = convert_initialized_extent(handle,
4257 inode, map, path, &allocated);
4258 if (IS_ERR(path))
4259 err = PTR_ERR(path);
4260 goto out;
4261 } else if (!ext4_ext_is_unwritten(ex)) {
4262 map->m_flags |= EXT4_MAP_MAPPED;
4263 map->m_pblk = newblock;
4264 if (allocated > map->m_len)
4265 allocated = map->m_len;
4266 map->m_len = allocated;
4267 ext4_ext_show_leaf(inode, path);
4268 goto out;
4269 }
4270
4271 path = ext4_ext_handle_unwritten_extents(
4272 handle, inode, map, path, flags,
4273 &allocated, newblock);
4274 if (IS_ERR(path))
4275 err = PTR_ERR(path);
4276 goto out;
4277 }
4278 }
4279
4280 /*
4281 * requested block isn't allocated yet;
4282 * we couldn't try to create block if flags doesn't contain EXT4_GET_BLOCKS_CREATE
4283 */
4284 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4285 ext4_lblk_t len;
4286
4287 len = ext4_ext_determine_insert_hole(inode, path, map->m_lblk);
4288
4289 map->m_pblk = 0;
4290 map->m_len = min_t(unsigned int, map->m_len, len);
4291 goto out;
4292 }
4293
4294 /*
4295 * Okay, we need to do block allocation.
4296 */
4297 newex.ee_block = cpu_to_le32(map->m_lblk);
4298 cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4299
4300 /*
4301 * If we are doing bigalloc, check to see if the extent returned
4302 * by ext4_find_extent() implies a cluster we can use.
4303 */
4304 if (cluster_offset && ex &&
4305 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4306 ar.len = allocated = map->m_len;
4307 newblock = map->m_pblk;
4308 goto got_allocated_blocks;
4309 }
4310
4311 /* find neighbour allocated blocks */
4312 ar.lleft = map->m_lblk;
4313 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4314 if (err)
4315 goto out;
4316 ar.lright = map->m_lblk;
4317 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4318 if (err < 0)
4319 goto out;
4320
4321 /* Check if the extent after searching to the right implies a
4322 * cluster we can use. */
4323 if ((sbi->s_cluster_ratio > 1) && err &&
4324 get_implied_cluster_alloc(inode->i_sb, map, &ex2, path)) {
4325 ar.len = allocated = map->m_len;
4326 newblock = map->m_pblk;
4327 err = 0;
4328 goto got_allocated_blocks;
4329 }
4330
4331 /*
4332 * See if request is beyond maximum number of blocks we can have in
4333 * a single extent. For an initialized extent this limit is
4334 * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
4335 * EXT_UNWRITTEN_MAX_LEN.
4336 */
4337 if (map->m_len > EXT_INIT_MAX_LEN &&
4338 !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4339 map->m_len = EXT_INIT_MAX_LEN;
4340 else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
4341 (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4342 map->m_len = EXT_UNWRITTEN_MAX_LEN;
4343
4344 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4345 newex.ee_len = cpu_to_le16(map->m_len);
4346 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4347 if (err)
4348 allocated = ext4_ext_get_actual_len(&newex);
4349 else
4350 allocated = map->m_len;
4351
4352 /* allocate new block */
4353 ar.inode = inode;
4354 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4355 ar.logical = map->m_lblk;
4356 /*
4357 * We calculate the offset from the beginning of the cluster
4358 * for the logical block number, since when we allocate a
4359 * physical cluster, the physical block should start at the
4360 * same offset from the beginning of the cluster. This is
4361 * needed so that future calls to get_implied_cluster_alloc()
4362 * work correctly.
4363 */
4364 offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4365 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4366 ar.goal -= offset;
4367 ar.logical -= offset;
4368 if (S_ISREG(inode->i_mode))
4369 ar.flags = EXT4_MB_HINT_DATA;
4370 else
4371 /* disable in-core preallocation for non-regular files */
4372 ar.flags = 0;
4373 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4374 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4375 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4376 ar.flags |= EXT4_MB_DELALLOC_RESERVED;
4377 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
4378 ar.flags |= EXT4_MB_USE_RESERVED;
4379 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4380 if (!newblock)
4381 goto out;
4382 allocated_clusters = ar.len;
4383 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4384 ext_debug(inode, "allocate new block: goal %llu, found %llu/%u, requested %u\n",
4385 ar.goal, newblock, ar.len, allocated);
4386 if (ar.len > allocated)
4387 ar.len = allocated;
4388
4389got_allocated_blocks:
4390 /* try to insert new extent into found leaf and return */
4391 pblk = newblock + offset;
4392 ext4_ext_store_pblock(&newex, pblk);
4393 newex.ee_len = cpu_to_le16(ar.len);
4394 /* Mark unwritten */
4395 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
4396 ext4_ext_mark_unwritten(&newex);
4397 map->m_flags |= EXT4_MAP_UNWRITTEN;
4398 }
4399
4400 path = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
4401 if (IS_ERR(path)) {
4402 err = PTR_ERR(path);
4403 if (allocated_clusters) {
4404 int fb_flags = 0;
4405
4406 /*
4407 * free data blocks we just allocated.
4408 * not a good idea to call discard here directly,
4409 * but otherwise we'd need to call it every free().
4410 */
4411 ext4_discard_preallocations(inode);
4412 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4413 fb_flags = EXT4_FREE_BLOCKS_NO_QUOT_UPDATE;
4414 ext4_free_blocks(handle, inode, NULL, newblock,
4415 EXT4_C2B(sbi, allocated_clusters),
4416 fb_flags);
4417 }
4418 goto out;
4419 }
4420
4421 /*
4422 * Cache the extent and update transaction to commit on fdatasync only
4423 * when it is _not_ an unwritten extent.
4424 */
4425 if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
4426 ext4_update_inode_fsync_trans(handle, inode, 1);
4427 else
4428 ext4_update_inode_fsync_trans(handle, inode, 0);
4429
4430 map->m_flags |= (EXT4_MAP_NEW | EXT4_MAP_MAPPED);
4431 map->m_pblk = pblk;
4432 map->m_len = ar.len;
4433 allocated = map->m_len;
4434 ext4_ext_show_leaf(inode, path);
4435out:
4436 ext4_free_ext_path(path);
4437
4438 trace_ext4_ext_map_blocks_exit(inode, flags, map,
4439 err ? err : allocated);
4440 return err ? err : allocated;
4441}
4442
4443int ext4_ext_truncate(handle_t *handle, struct inode *inode)
4444{
4445 struct super_block *sb = inode->i_sb;
4446 ext4_lblk_t last_block;
4447 int err = 0;
4448
4449 /*
4450 * TODO: optimization is possible here.
4451 * Probably we need not scan at all,
4452 * because page truncation is enough.
4453 */
4454
4455 /* we have to know where to truncate from in crash case */
4456 EXT4_I(inode)->i_disksize = inode->i_size;
4457 err = ext4_mark_inode_dirty(handle, inode);
4458 if (err)
4459 return err;
4460
4461 last_block = (inode->i_size + sb->s_blocksize - 1)
4462 >> EXT4_BLOCK_SIZE_BITS(sb);
4463 ext4_es_remove_extent(inode, last_block, EXT_MAX_BLOCKS - last_block);
4464
4465retry_remove_space:
4466 err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4467 if (err == -ENOMEM) {
4468 memalloc_retry_wait(GFP_ATOMIC);
4469 goto retry_remove_space;
4470 }
4471 return err;
4472}
4473
4474static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
4475 ext4_lblk_t len, loff_t new_size,
4476 int flags)
4477{
4478 struct inode *inode = file_inode(file);
4479 handle_t *handle;
4480 int ret = 0, ret2 = 0, ret3 = 0;
4481 int retries = 0;
4482 int depth = 0;
4483 struct ext4_map_blocks map;
4484 unsigned int credits;
4485 loff_t epos, old_size = i_size_read(inode);
4486
4487 BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS));
4488 map.m_lblk = offset;
4489 map.m_len = len;
4490 /*
4491 * Don't normalize the request if it can fit in one extent so
4492 * that it doesn't get unnecessarily split into multiple
4493 * extents.
4494 */
4495 if (len <= EXT_UNWRITTEN_MAX_LEN)
4496 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4497
4498 /*
4499 * credits to insert 1 extent into extent tree
4500 */
4501 credits = ext4_chunk_trans_blocks(inode, len);
4502 depth = ext_depth(inode);
4503
4504retry:
4505 while (len) {
4506 /*
4507 * Recalculate credits when extent tree depth changes.
4508 */
4509 if (depth != ext_depth(inode)) {
4510 credits = ext4_chunk_trans_blocks(inode, len);
4511 depth = ext_depth(inode);
4512 }
4513
4514 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4515 credits);
4516 if (IS_ERR(handle)) {
4517 ret = PTR_ERR(handle);
4518 break;
4519 }
4520 ret = ext4_map_blocks(handle, inode, &map, flags);
4521 if (ret <= 0) {
4522 ext4_debug("inode #%lu: block %u: len %u: "
4523 "ext4_ext_map_blocks returned %d",
4524 inode->i_ino, map.m_lblk,
4525 map.m_len, ret);
4526 ext4_mark_inode_dirty(handle, inode);
4527 ext4_journal_stop(handle);
4528 break;
4529 }
4530 /*
4531 * allow a full retry cycle for any remaining allocations
4532 */
4533 retries = 0;
4534 map.m_lblk += ret;
4535 map.m_len = len = len - ret;
4536 epos = (loff_t)map.m_lblk << inode->i_blkbits;
4537 inode_set_ctime_current(inode);
4538 if (new_size) {
4539 if (epos > new_size)
4540 epos = new_size;
4541 if (ext4_update_inode_size(inode, epos) & 0x1)
4542 inode_set_mtime_to_ts(inode,
4543 inode_get_ctime(inode));
4544 if (epos > old_size) {
4545 pagecache_isize_extended(inode, old_size, epos);
4546 ext4_zero_partial_blocks(handle, inode,
4547 old_size, epos - old_size);
4548 }
4549 }
4550 ret2 = ext4_mark_inode_dirty(handle, inode);
4551 ext4_update_inode_fsync_trans(handle, inode, 1);
4552 ret3 = ext4_journal_stop(handle);
4553 ret2 = ret3 ? ret3 : ret2;
4554 if (unlikely(ret2))
4555 break;
4556 }
4557 if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
4558 goto retry;
4559
4560 return ret > 0 ? ret2 : ret;
4561}
4562
4563static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len);
4564
4565static int ext4_insert_range(struct file *file, loff_t offset, loff_t len);
4566
4567static long ext4_zero_range(struct file *file, loff_t offset,
4568 loff_t len, int mode)
4569{
4570 struct inode *inode = file_inode(file);
4571 struct address_space *mapping = file->f_mapping;
4572 handle_t *handle = NULL;
4573 unsigned int max_blocks;
4574 loff_t new_size = 0;
4575 int ret = 0;
4576 int flags;
4577 int credits;
4578 int partial_begin, partial_end;
4579 loff_t start, end;
4580 ext4_lblk_t lblk;
4581 unsigned int blkbits = inode->i_blkbits;
4582
4583 trace_ext4_zero_range(inode, offset, len, mode);
4584
4585 /*
4586 * Round up offset. This is not fallocate, we need to zero out
4587 * blocks, so convert interior block aligned part of the range to
4588 * unwritten and possibly manually zero out unaligned parts of the
4589 * range. Here, start and partial_begin are inclusive, end and
4590 * partial_end are exclusive.
4591 */
4592 start = round_up(offset, 1 << blkbits);
4593 end = round_down((offset + len), 1 << blkbits);
4594
4595 if (start < offset || end > offset + len)
4596 return -EINVAL;
4597 partial_begin = offset & ((1 << blkbits) - 1);
4598 partial_end = (offset + len) & ((1 << blkbits) - 1);
4599
4600 lblk = start >> blkbits;
4601 max_blocks = (end >> blkbits);
4602 if (max_blocks < lblk)
4603 max_blocks = 0;
4604 else
4605 max_blocks -= lblk;
4606
4607 inode_lock(inode);
4608
4609 /*
4610 * Indirect files do not support unwritten extents
4611 */
4612 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4613 ret = -EOPNOTSUPP;
4614 goto out_mutex;
4615 }
4616
4617 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4618 (offset + len > inode->i_size ||
4619 offset + len > EXT4_I(inode)->i_disksize)) {
4620 new_size = offset + len;
4621 ret = inode_newsize_ok(inode, new_size);
4622 if (ret)
4623 goto out_mutex;
4624 }
4625
4626 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4627
4628 /* Wait all existing dio workers, newcomers will block on i_rwsem */
4629 inode_dio_wait(inode);
4630
4631 ret = file_modified(file);
4632 if (ret)
4633 goto out_mutex;
4634
4635 /* Preallocate the range including the unaligned edges */
4636 if (partial_begin || partial_end) {
4637 ret = ext4_alloc_file_blocks(file,
4638 round_down(offset, 1 << blkbits) >> blkbits,
4639 (round_up((offset + len), 1 << blkbits) -
4640 round_down(offset, 1 << blkbits)) >> blkbits,
4641 new_size, flags);
4642 if (ret)
4643 goto out_mutex;
4644
4645 }
4646
4647 /* Zero range excluding the unaligned edges */
4648 if (max_blocks > 0) {
4649 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
4650 EXT4_EX_NOCACHE);
4651
4652 /*
4653 * Prevent page faults from reinstantiating pages we have
4654 * released from page cache.
4655 */
4656 filemap_invalidate_lock(mapping);
4657
4658 ret = ext4_break_layouts(inode);
4659 if (ret) {
4660 filemap_invalidate_unlock(mapping);
4661 goto out_mutex;
4662 }
4663
4664 ret = ext4_update_disksize_before_punch(inode, offset, len);
4665 if (ret) {
4666 filemap_invalidate_unlock(mapping);
4667 goto out_mutex;
4668 }
4669
4670 /*
4671 * For journalled data we need to write (and checkpoint) pages
4672 * before discarding page cache to avoid inconsitent data on
4673 * disk in case of crash before zeroing trans is committed.
4674 */
4675 if (ext4_should_journal_data(inode)) {
4676 ret = filemap_write_and_wait_range(mapping, start,
4677 end - 1);
4678 if (ret) {
4679 filemap_invalidate_unlock(mapping);
4680 goto out_mutex;
4681 }
4682 }
4683
4684 /* Now release the pages and zero block aligned part of pages */
4685 truncate_pagecache_range(inode, start, end - 1);
4686 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
4687
4688 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4689 flags);
4690 filemap_invalidate_unlock(mapping);
4691 if (ret)
4692 goto out_mutex;
4693 }
4694 if (!partial_begin && !partial_end)
4695 goto out_mutex;
4696
4697 /*
4698 * In worst case we have to writeout two nonadjacent unwritten
4699 * blocks and update the inode
4700 */
4701 credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
4702 if (ext4_should_journal_data(inode))
4703 credits += 2;
4704 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
4705 if (IS_ERR(handle)) {
4706 ret = PTR_ERR(handle);
4707 ext4_std_error(inode->i_sb, ret);
4708 goto out_mutex;
4709 }
4710
4711 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
4712 if (new_size)
4713 ext4_update_inode_size(inode, new_size);
4714 ret = ext4_mark_inode_dirty(handle, inode);
4715 if (unlikely(ret))
4716 goto out_handle;
4717 /* Zero out partial block at the edges of the range */
4718 ret = ext4_zero_partial_blocks(handle, inode, offset, len);
4719 if (ret >= 0)
4720 ext4_update_inode_fsync_trans(handle, inode, 1);
4721
4722 if (file->f_flags & O_SYNC)
4723 ext4_handle_sync(handle);
4724
4725out_handle:
4726 ext4_journal_stop(handle);
4727out_mutex:
4728 inode_unlock(inode);
4729 return ret;
4730}
4731
4732/*
4733 * preallocate space for a file. This implements ext4's fallocate file
4734 * operation, which gets called from sys_fallocate system call.
4735 * For block-mapped files, posix_fallocate should fall back to the method
4736 * of writing zeroes to the required new blocks (the same behavior which is
4737 * expected for file systems which do not support fallocate() system call).
4738 */
4739long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4740{
4741 struct inode *inode = file_inode(file);
4742 loff_t new_size = 0;
4743 unsigned int max_blocks;
4744 int ret = 0;
4745 int flags;
4746 ext4_lblk_t lblk;
4747 unsigned int blkbits = inode->i_blkbits;
4748
4749 /*
4750 * Encrypted inodes can't handle collapse range or insert
4751 * range since we would need to re-encrypt blocks with a
4752 * different IV or XTS tweak (which are based on the logical
4753 * block number).
4754 */
4755 if (IS_ENCRYPTED(inode) &&
4756 (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE)))
4757 return -EOPNOTSUPP;
4758
4759 /* Return error if mode is not supported */
4760 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
4761 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
4762 FALLOC_FL_INSERT_RANGE))
4763 return -EOPNOTSUPP;
4764
4765 inode_lock(inode);
4766 ret = ext4_convert_inline_data(inode);
4767 inode_unlock(inode);
4768 if (ret)
4769 goto exit;
4770
4771 if (mode & FALLOC_FL_PUNCH_HOLE) {
4772 ret = ext4_punch_hole(file, offset, len);
4773 goto exit;
4774 }
4775
4776 if (mode & FALLOC_FL_COLLAPSE_RANGE) {
4777 ret = ext4_collapse_range(file, offset, len);
4778 goto exit;
4779 }
4780
4781 if (mode & FALLOC_FL_INSERT_RANGE) {
4782 ret = ext4_insert_range(file, offset, len);
4783 goto exit;
4784 }
4785
4786 if (mode & FALLOC_FL_ZERO_RANGE) {
4787 ret = ext4_zero_range(file, offset, len, mode);
4788 goto exit;
4789 }
4790 trace_ext4_fallocate_enter(inode, offset, len, mode);
4791 lblk = offset >> blkbits;
4792
4793 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
4794 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4795
4796 inode_lock(inode);
4797
4798 /*
4799 * We only support preallocation for extent-based files only
4800 */
4801 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4802 ret = -EOPNOTSUPP;
4803 goto out;
4804 }
4805
4806 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4807 (offset + len > inode->i_size ||
4808 offset + len > EXT4_I(inode)->i_disksize)) {
4809 new_size = offset + len;
4810 ret = inode_newsize_ok(inode, new_size);
4811 if (ret)
4812 goto out;
4813 }
4814
4815 /* Wait all existing dio workers, newcomers will block on i_rwsem */
4816 inode_dio_wait(inode);
4817
4818 ret = file_modified(file);
4819 if (ret)
4820 goto out;
4821
4822 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size, flags);
4823 if (ret)
4824 goto out;
4825
4826 if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
4827 ret = ext4_fc_commit(EXT4_SB(inode->i_sb)->s_journal,
4828 EXT4_I(inode)->i_sync_tid);
4829 }
4830out:
4831 inode_unlock(inode);
4832 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4833exit:
4834 return ret;
4835}
4836
4837/*
4838 * This function convert a range of blocks to written extents
4839 * The caller of this function will pass the start offset and the size.
4840 * all unwritten extents within this range will be converted to
4841 * written extents.
4842 *
4843 * This function is called from the direct IO end io call back
4844 * function, to convert the fallocated extents after IO is completed.
4845 * Returns 0 on success.
4846 */
4847int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
4848 loff_t offset, ssize_t len)
4849{
4850 unsigned int max_blocks;
4851 int ret = 0, ret2 = 0, ret3 = 0;
4852 struct ext4_map_blocks map;
4853 unsigned int blkbits = inode->i_blkbits;
4854 unsigned int credits = 0;
4855
4856 map.m_lblk = offset >> blkbits;
4857 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
4858
4859 if (!handle) {
4860 /*
4861 * credits to insert 1 extent into extent tree
4862 */
4863 credits = ext4_chunk_trans_blocks(inode, max_blocks);
4864 }
4865 while (ret >= 0 && ret < max_blocks) {
4866 map.m_lblk += ret;
4867 map.m_len = (max_blocks -= ret);
4868 if (credits) {
4869 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4870 credits);
4871 if (IS_ERR(handle)) {
4872 ret = PTR_ERR(handle);
4873 break;
4874 }
4875 }
4876 ret = ext4_map_blocks(handle, inode, &map,
4877 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
4878 if (ret <= 0)
4879 ext4_warning(inode->i_sb,
4880 "inode #%lu: block %u: len %u: "
4881 "ext4_ext_map_blocks returned %d",
4882 inode->i_ino, map.m_lblk,
4883 map.m_len, ret);
4884 ret2 = ext4_mark_inode_dirty(handle, inode);
4885 if (credits) {
4886 ret3 = ext4_journal_stop(handle);
4887 if (unlikely(ret3))
4888 ret2 = ret3;
4889 }
4890
4891 if (ret <= 0 || ret2)
4892 break;
4893 }
4894 return ret > 0 ? ret2 : ret;
4895}
4896
4897int ext4_convert_unwritten_io_end_vec(handle_t *handle, ext4_io_end_t *io_end)
4898{
4899 int ret = 0, err = 0;
4900 struct ext4_io_end_vec *io_end_vec;
4901
4902 /*
4903 * This is somewhat ugly but the idea is clear: When transaction is
4904 * reserved, everything goes into it. Otherwise we rather start several
4905 * smaller transactions for conversion of each extent separately.
4906 */
4907 if (handle) {
4908 handle = ext4_journal_start_reserved(handle,
4909 EXT4_HT_EXT_CONVERT);
4910 if (IS_ERR(handle))
4911 return PTR_ERR(handle);
4912 }
4913
4914 list_for_each_entry(io_end_vec, &io_end->list_vec, list) {
4915 ret = ext4_convert_unwritten_extents(handle, io_end->inode,
4916 io_end_vec->offset,
4917 io_end_vec->size);
4918 if (ret)
4919 break;
4920 }
4921
4922 if (handle)
4923 err = ext4_journal_stop(handle);
4924
4925 return ret < 0 ? ret : err;
4926}
4927
4928static int ext4_iomap_xattr_fiemap(struct inode *inode, struct iomap *iomap)
4929{
4930 __u64 physical = 0;
4931 __u64 length = 0;
4932 int blockbits = inode->i_sb->s_blocksize_bits;
4933 int error = 0;
4934 u16 iomap_type;
4935
4936 /* in-inode? */
4937 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
4938 struct ext4_iloc iloc;
4939 int offset; /* offset of xattr in inode */
4940
4941 error = ext4_get_inode_loc(inode, &iloc);
4942 if (error)
4943 return error;
4944 physical = (__u64)iloc.bh->b_blocknr << blockbits;
4945 offset = EXT4_GOOD_OLD_INODE_SIZE +
4946 EXT4_I(inode)->i_extra_isize;
4947 physical += offset;
4948 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
4949 brelse(iloc.bh);
4950 iomap_type = IOMAP_INLINE;
4951 } else if (EXT4_I(inode)->i_file_acl) { /* external block */
4952 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
4953 length = inode->i_sb->s_blocksize;
4954 iomap_type = IOMAP_MAPPED;
4955 } else {
4956 /* no in-inode or external block for xattr, so return -ENOENT */
4957 error = -ENOENT;
4958 goto out;
4959 }
4960
4961 iomap->addr = physical;
4962 iomap->offset = 0;
4963 iomap->length = length;
4964 iomap->type = iomap_type;
4965 iomap->flags = 0;
4966out:
4967 return error;
4968}
4969
4970static int ext4_iomap_xattr_begin(struct inode *inode, loff_t offset,
4971 loff_t length, unsigned flags,
4972 struct iomap *iomap, struct iomap *srcmap)
4973{
4974 int error;
4975
4976 error = ext4_iomap_xattr_fiemap(inode, iomap);
4977 if (error == 0 && (offset >= iomap->length))
4978 error = -ENOENT;
4979 return error;
4980}
4981
4982static const struct iomap_ops ext4_iomap_xattr_ops = {
4983 .iomap_begin = ext4_iomap_xattr_begin,
4984};
4985
4986static int ext4_fiemap_check_ranges(struct inode *inode, u64 start, u64 *len)
4987{
4988 u64 maxbytes;
4989
4990 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
4991 maxbytes = inode->i_sb->s_maxbytes;
4992 else
4993 maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
4994
4995 if (*len == 0)
4996 return -EINVAL;
4997 if (start > maxbytes)
4998 return -EFBIG;
4999
5000 /*
5001 * Shrink request scope to what the fs can actually handle.
5002 */
5003 if (*len > maxbytes || (maxbytes - *len) < start)
5004 *len = maxbytes - start;
5005 return 0;
5006}
5007
5008int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
5009 u64 start, u64 len)
5010{
5011 int error = 0;
5012
5013 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
5014 error = ext4_ext_precache(inode);
5015 if (error)
5016 return error;
5017 fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
5018 }
5019
5020 /*
5021 * For bitmap files the maximum size limit could be smaller than
5022 * s_maxbytes, so check len here manually instead of just relying on the
5023 * generic check.
5024 */
5025 error = ext4_fiemap_check_ranges(inode, start, &len);
5026 if (error)
5027 return error;
5028
5029 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
5030 fieinfo->fi_flags &= ~FIEMAP_FLAG_XATTR;
5031 return iomap_fiemap(inode, fieinfo, start, len,
5032 &ext4_iomap_xattr_ops);
5033 }
5034
5035 return iomap_fiemap(inode, fieinfo, start, len, &ext4_iomap_report_ops);
5036}
5037
5038int ext4_get_es_cache(struct inode *inode, struct fiemap_extent_info *fieinfo,
5039 __u64 start, __u64 len)
5040{
5041 ext4_lblk_t start_blk, len_blks;
5042 __u64 last_blk;
5043 int error = 0;
5044
5045 if (ext4_has_inline_data(inode)) {
5046 int has_inline;
5047
5048 down_read(&EXT4_I(inode)->xattr_sem);
5049 has_inline = ext4_has_inline_data(inode);
5050 up_read(&EXT4_I(inode)->xattr_sem);
5051 if (has_inline)
5052 return 0;
5053 }
5054
5055 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
5056 error = ext4_ext_precache(inode);
5057 if (error)
5058 return error;
5059 fieinfo->fi_flags &= ~FIEMAP_FLAG_CACHE;
5060 }
5061
5062 error = fiemap_prep(inode, fieinfo, start, &len, 0);
5063 if (error)
5064 return error;
5065
5066 error = ext4_fiemap_check_ranges(inode, start, &len);
5067 if (error)
5068 return error;
5069
5070 start_blk = start >> inode->i_sb->s_blocksize_bits;
5071 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
5072 if (last_blk >= EXT_MAX_BLOCKS)
5073 last_blk = EXT_MAX_BLOCKS-1;
5074 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
5075
5076 /*
5077 * Walk the extent tree gathering extent information
5078 * and pushing extents back to the user.
5079 */
5080 return ext4_fill_es_cache_info(inode, start_blk, len_blks, fieinfo);
5081}
5082
5083/*
5084 * ext4_ext_shift_path_extents:
5085 * Shift the extents of a path structure lying between path[depth].p_ext
5086 * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
5087 * if it is right shift or left shift operation.
5088 */
5089static int
5090ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
5091 struct inode *inode, handle_t *handle,
5092 enum SHIFT_DIRECTION SHIFT)
5093{
5094 int depth, err = 0;
5095 struct ext4_extent *ex_start, *ex_last;
5096 bool update = false;
5097 int credits, restart_credits;
5098 depth = path->p_depth;
5099
5100 while (depth >= 0) {
5101 if (depth == path->p_depth) {
5102 ex_start = path[depth].p_ext;
5103 if (!ex_start)
5104 return -EFSCORRUPTED;
5105
5106 ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
5107 /* leaf + sb + inode */
5108 credits = 3;
5109 if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) {
5110 update = true;
5111 /* extent tree + sb + inode */
5112 credits = depth + 2;
5113 }
5114
5115 restart_credits = ext4_writepage_trans_blocks(inode);
5116 err = ext4_datasem_ensure_credits(handle, inode, credits,
5117 restart_credits, 0);
5118 if (err) {
5119 if (err > 0)
5120 err = -EAGAIN;
5121 goto out;
5122 }
5123
5124 err = ext4_ext_get_access(handle, inode, path + depth);
5125 if (err)
5126 goto out;
5127
5128 while (ex_start <= ex_last) {
5129 if (SHIFT == SHIFT_LEFT) {
5130 le32_add_cpu(&ex_start->ee_block,
5131 -shift);
5132 /* Try to merge to the left. */
5133 if ((ex_start >
5134 EXT_FIRST_EXTENT(path[depth].p_hdr))
5135 &&
5136 ext4_ext_try_to_merge_right(inode,
5137 path, ex_start - 1))
5138 ex_last--;
5139 else
5140 ex_start++;
5141 } else {
5142 le32_add_cpu(&ex_last->ee_block, shift);
5143 ext4_ext_try_to_merge_right(inode, path,
5144 ex_last);
5145 ex_last--;
5146 }
5147 }
5148 err = ext4_ext_dirty(handle, inode, path + depth);
5149 if (err)
5150 goto out;
5151
5152 if (--depth < 0 || !update)
5153 break;
5154 }
5155
5156 /* Update index too */
5157 err = ext4_ext_get_access(handle, inode, path + depth);
5158 if (err)
5159 goto out;
5160
5161 if (SHIFT == SHIFT_LEFT)
5162 le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
5163 else
5164 le32_add_cpu(&path[depth].p_idx->ei_block, shift);
5165 err = ext4_ext_dirty(handle, inode, path + depth);
5166 if (err)
5167 goto out;
5168
5169 /* we are done if current index is not a starting index */
5170 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
5171 break;
5172
5173 depth--;
5174 }
5175
5176out:
5177 return err;
5178}
5179
5180/*
5181 * ext4_ext_shift_extents:
5182 * All the extents which lies in the range from @start to the last allocated
5183 * block for the @inode are shifted either towards left or right (depending
5184 * upon @SHIFT) by @shift blocks.
5185 * On success, 0 is returned, error otherwise.
5186 */
5187static int
5188ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
5189 ext4_lblk_t start, ext4_lblk_t shift,
5190 enum SHIFT_DIRECTION SHIFT)
5191{
5192 struct ext4_ext_path *path;
5193 int ret = 0, depth;
5194 struct ext4_extent *extent;
5195 ext4_lblk_t stop, *iterator, ex_start, ex_end;
5196 ext4_lblk_t tmp = EXT_MAX_BLOCKS;
5197
5198 /* Let path point to the last extent */
5199 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
5200 EXT4_EX_NOCACHE);
5201 if (IS_ERR(path))
5202 return PTR_ERR(path);
5203
5204 depth = path->p_depth;
5205 extent = path[depth].p_ext;
5206 if (!extent)
5207 goto out;
5208
5209 stop = le32_to_cpu(extent->ee_block);
5210
5211 /*
5212 * For left shifts, make sure the hole on the left is big enough to
5213 * accommodate the shift. For right shifts, make sure the last extent
5214 * won't be shifted beyond EXT_MAX_BLOCKS.
5215 */
5216 if (SHIFT == SHIFT_LEFT) {
5217 path = ext4_find_extent(inode, start - 1, path,
5218 EXT4_EX_NOCACHE);
5219 if (IS_ERR(path))
5220 return PTR_ERR(path);
5221 depth = path->p_depth;
5222 extent = path[depth].p_ext;
5223 if (extent) {
5224 ex_start = le32_to_cpu(extent->ee_block);
5225 ex_end = le32_to_cpu(extent->ee_block) +
5226 ext4_ext_get_actual_len(extent);
5227 } else {
5228 ex_start = 0;
5229 ex_end = 0;
5230 }
5231
5232 if ((start == ex_start && shift > ex_start) ||
5233 (shift > start - ex_end)) {
5234 ret = -EINVAL;
5235 goto out;
5236 }
5237 } else {
5238 if (shift > EXT_MAX_BLOCKS -
5239 (stop + ext4_ext_get_actual_len(extent))) {
5240 ret = -EINVAL;
5241 goto out;
5242 }
5243 }
5244
5245 /*
5246 * In case of left shift, iterator points to start and it is increased
5247 * till we reach stop. In case of right shift, iterator points to stop
5248 * and it is decreased till we reach start.
5249 */
5250again:
5251 ret = 0;
5252 if (SHIFT == SHIFT_LEFT)
5253 iterator = &start;
5254 else
5255 iterator = &stop;
5256
5257 if (tmp != EXT_MAX_BLOCKS)
5258 *iterator = tmp;
5259
5260 /*
5261 * Its safe to start updating extents. Start and stop are unsigned, so
5262 * in case of right shift if extent with 0 block is reached, iterator
5263 * becomes NULL to indicate the end of the loop.
5264 */
5265 while (iterator && start <= stop) {
5266 path = ext4_find_extent(inode, *iterator, path,
5267 EXT4_EX_NOCACHE);
5268 if (IS_ERR(path))
5269 return PTR_ERR(path);
5270 depth = path->p_depth;
5271 extent = path[depth].p_ext;
5272 if (!extent) {
5273 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
5274 (unsigned long) *iterator);
5275 return -EFSCORRUPTED;
5276 }
5277 if (SHIFT == SHIFT_LEFT && *iterator >
5278 le32_to_cpu(extent->ee_block)) {
5279 /* Hole, move to the next extent */
5280 if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
5281 path[depth].p_ext++;
5282 } else {
5283 *iterator = ext4_ext_next_allocated_block(path);
5284 continue;
5285 }
5286 }
5287
5288 tmp = *iterator;
5289 if (SHIFT == SHIFT_LEFT) {
5290 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5291 *iterator = le32_to_cpu(extent->ee_block) +
5292 ext4_ext_get_actual_len(extent);
5293 } else {
5294 extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
5295 if (le32_to_cpu(extent->ee_block) > start)
5296 *iterator = le32_to_cpu(extent->ee_block) - 1;
5297 else if (le32_to_cpu(extent->ee_block) == start)
5298 iterator = NULL;
5299 else {
5300 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5301 while (le32_to_cpu(extent->ee_block) >= start)
5302 extent--;
5303
5304 if (extent == EXT_LAST_EXTENT(path[depth].p_hdr))
5305 break;
5306
5307 extent++;
5308 iterator = NULL;
5309 }
5310 path[depth].p_ext = extent;
5311 }
5312 ret = ext4_ext_shift_path_extents(path, shift, inode,
5313 handle, SHIFT);
5314 /* iterator can be NULL which means we should break */
5315 if (ret == -EAGAIN)
5316 goto again;
5317 if (ret)
5318 break;
5319 }
5320out:
5321 ext4_free_ext_path(path);
5322 return ret;
5323}
5324
5325/*
5326 * ext4_collapse_range:
5327 * This implements the fallocate's collapse range functionality for ext4
5328 * Returns: 0 and non-zero on error.
5329 */
5330static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
5331{
5332 struct inode *inode = file_inode(file);
5333 struct super_block *sb = inode->i_sb;
5334 struct address_space *mapping = inode->i_mapping;
5335 ext4_lblk_t punch_start, punch_stop;
5336 handle_t *handle;
5337 unsigned int credits;
5338 loff_t new_size, ioffset;
5339 int ret;
5340
5341 /*
5342 * We need to test this early because xfstests assumes that a
5343 * collapse range of (0, 1) will return EOPNOTSUPP if the file
5344 * system does not support collapse range.
5345 */
5346 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5347 return -EOPNOTSUPP;
5348
5349 /* Collapse range works only on fs cluster size aligned regions. */
5350 if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
5351 return -EINVAL;
5352
5353 trace_ext4_collapse_range(inode, offset, len);
5354
5355 punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5356 punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb);
5357
5358 inode_lock(inode);
5359 /*
5360 * There is no need to overlap collapse range with EOF, in which case
5361 * it is effectively a truncate operation
5362 */
5363 if (offset + len >= inode->i_size) {
5364 ret = -EINVAL;
5365 goto out_mutex;
5366 }
5367
5368 /* Currently just for extent based files */
5369 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5370 ret = -EOPNOTSUPP;
5371 goto out_mutex;
5372 }
5373
5374 /* Wait for existing dio to complete */
5375 inode_dio_wait(inode);
5376
5377 ret = file_modified(file);
5378 if (ret)
5379 goto out_mutex;
5380
5381 /*
5382 * Prevent page faults from reinstantiating pages we have released from
5383 * page cache.
5384 */
5385 filemap_invalidate_lock(mapping);
5386
5387 ret = ext4_break_layouts(inode);
5388 if (ret)
5389 goto out_mmap;
5390
5391 /*
5392 * Need to round down offset to be aligned with page size boundary
5393 * for page size > block size.
5394 */
5395 ioffset = round_down(offset, PAGE_SIZE);
5396 /*
5397 * Write tail of the last page before removed range since it will get
5398 * removed from the page cache below.
5399 */
5400 ret = filemap_write_and_wait_range(mapping, ioffset, offset);
5401 if (ret)
5402 goto out_mmap;
5403 /*
5404 * Write data that will be shifted to preserve them when discarding
5405 * page cache below. We are also protected from pages becoming dirty
5406 * by i_rwsem and invalidate_lock.
5407 */
5408 ret = filemap_write_and_wait_range(mapping, offset + len,
5409 LLONG_MAX);
5410 if (ret)
5411 goto out_mmap;
5412 truncate_pagecache(inode, ioffset);
5413
5414 credits = ext4_writepage_trans_blocks(inode);
5415 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5416 if (IS_ERR(handle)) {
5417 ret = PTR_ERR(handle);
5418 goto out_mmap;
5419 }
5420 ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
5421
5422 down_write(&EXT4_I(inode)->i_data_sem);
5423 ext4_discard_preallocations(inode);
5424 ext4_es_remove_extent(inode, punch_start, EXT_MAX_BLOCKS - punch_start);
5425
5426 ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
5427 if (ret) {
5428 up_write(&EXT4_I(inode)->i_data_sem);
5429 goto out_stop;
5430 }
5431 ext4_discard_preallocations(inode);
5432
5433 ret = ext4_ext_shift_extents(inode, handle, punch_stop,
5434 punch_stop - punch_start, SHIFT_LEFT);
5435 if (ret) {
5436 up_write(&EXT4_I(inode)->i_data_sem);
5437 goto out_stop;
5438 }
5439
5440 new_size = inode->i_size - len;
5441 i_size_write(inode, new_size);
5442 EXT4_I(inode)->i_disksize = new_size;
5443
5444 up_write(&EXT4_I(inode)->i_data_sem);
5445 if (IS_SYNC(inode))
5446 ext4_handle_sync(handle);
5447 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
5448 ret = ext4_mark_inode_dirty(handle, inode);
5449 ext4_update_inode_fsync_trans(handle, inode, 1);
5450
5451out_stop:
5452 ext4_journal_stop(handle);
5453out_mmap:
5454 filemap_invalidate_unlock(mapping);
5455out_mutex:
5456 inode_unlock(inode);
5457 return ret;
5458}
5459
5460/*
5461 * ext4_insert_range:
5462 * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
5463 * The data blocks starting from @offset to the EOF are shifted by @len
5464 * towards right to create a hole in the @inode. Inode size is increased
5465 * by len bytes.
5466 * Returns 0 on success, error otherwise.
5467 */
5468static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
5469{
5470 struct inode *inode = file_inode(file);
5471 struct super_block *sb = inode->i_sb;
5472 struct address_space *mapping = inode->i_mapping;
5473 handle_t *handle;
5474 struct ext4_ext_path *path;
5475 struct ext4_extent *extent;
5476 ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
5477 unsigned int credits, ee_len;
5478 int ret = 0, depth, split_flag = 0;
5479 loff_t ioffset;
5480
5481 /*
5482 * We need to test this early because xfstests assumes that an
5483 * insert range of (0, 1) will return EOPNOTSUPP if the file
5484 * system does not support insert range.
5485 */
5486 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5487 return -EOPNOTSUPP;
5488
5489 /* Insert range works only on fs cluster size aligned regions. */
5490 if (!IS_ALIGNED(offset | len, EXT4_CLUSTER_SIZE(sb)))
5491 return -EINVAL;
5492
5493 trace_ext4_insert_range(inode, offset, len);
5494
5495 offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5496 len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
5497
5498 inode_lock(inode);
5499 /* Currently just for extent based files */
5500 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5501 ret = -EOPNOTSUPP;
5502 goto out_mutex;
5503 }
5504
5505 /* Check whether the maximum file size would be exceeded */
5506 if (len > inode->i_sb->s_maxbytes - inode->i_size) {
5507 ret = -EFBIG;
5508 goto out_mutex;
5509 }
5510
5511 /* Offset must be less than i_size */
5512 if (offset >= inode->i_size) {
5513 ret = -EINVAL;
5514 goto out_mutex;
5515 }
5516
5517 /* Wait for existing dio to complete */
5518 inode_dio_wait(inode);
5519
5520 ret = file_modified(file);
5521 if (ret)
5522 goto out_mutex;
5523
5524 /*
5525 * Prevent page faults from reinstantiating pages we have released from
5526 * page cache.
5527 */
5528 filemap_invalidate_lock(mapping);
5529
5530 ret = ext4_break_layouts(inode);
5531 if (ret)
5532 goto out_mmap;
5533
5534 /*
5535 * Need to round down to align start offset to page size boundary
5536 * for page size > block size.
5537 */
5538 ioffset = round_down(offset, PAGE_SIZE);
5539 /* Write out all dirty pages */
5540 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5541 LLONG_MAX);
5542 if (ret)
5543 goto out_mmap;
5544 truncate_pagecache(inode, ioffset);
5545
5546 credits = ext4_writepage_trans_blocks(inode);
5547 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5548 if (IS_ERR(handle)) {
5549 ret = PTR_ERR(handle);
5550 goto out_mmap;
5551 }
5552 ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
5553
5554 /* Expand file to avoid data loss if there is error while shifting */
5555 inode->i_size += len;
5556 EXT4_I(inode)->i_disksize += len;
5557 inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
5558 ret = ext4_mark_inode_dirty(handle, inode);
5559 if (ret)
5560 goto out_stop;
5561
5562 down_write(&EXT4_I(inode)->i_data_sem);
5563 ext4_discard_preallocations(inode);
5564
5565 path = ext4_find_extent(inode, offset_lblk, NULL, 0);
5566 if (IS_ERR(path)) {
5567 up_write(&EXT4_I(inode)->i_data_sem);
5568 ret = PTR_ERR(path);
5569 goto out_stop;
5570 }
5571
5572 depth = ext_depth(inode);
5573 extent = path[depth].p_ext;
5574 if (extent) {
5575 ee_start_lblk = le32_to_cpu(extent->ee_block);
5576 ee_len = ext4_ext_get_actual_len(extent);
5577
5578 /*
5579 * If offset_lblk is not the starting block of extent, split
5580 * the extent @offset_lblk
5581 */
5582 if ((offset_lblk > ee_start_lblk) &&
5583 (offset_lblk < (ee_start_lblk + ee_len))) {
5584 if (ext4_ext_is_unwritten(extent))
5585 split_flag = EXT4_EXT_MARK_UNWRIT1 |
5586 EXT4_EXT_MARK_UNWRIT2;
5587 path = ext4_split_extent_at(handle, inode, path,
5588 offset_lblk, split_flag,
5589 EXT4_EX_NOCACHE |
5590 EXT4_GET_BLOCKS_PRE_IO |
5591 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5592 }
5593
5594 if (IS_ERR(path)) {
5595 up_write(&EXT4_I(inode)->i_data_sem);
5596 ret = PTR_ERR(path);
5597 goto out_stop;
5598 }
5599 }
5600
5601 ext4_free_ext_path(path);
5602 ext4_es_remove_extent(inode, offset_lblk, EXT_MAX_BLOCKS - offset_lblk);
5603
5604 /*
5605 * if offset_lblk lies in a hole which is at start of file, use
5606 * ee_start_lblk to shift extents
5607 */
5608 ret = ext4_ext_shift_extents(inode, handle,
5609 max(ee_start_lblk, offset_lblk), len_lblk, SHIFT_RIGHT);
5610
5611 up_write(&EXT4_I(inode)->i_data_sem);
5612 if (IS_SYNC(inode))
5613 ext4_handle_sync(handle);
5614 if (ret >= 0)
5615 ext4_update_inode_fsync_trans(handle, inode, 1);
5616
5617out_stop:
5618 ext4_journal_stop(handle);
5619out_mmap:
5620 filemap_invalidate_unlock(mapping);
5621out_mutex:
5622 inode_unlock(inode);
5623 return ret;
5624}
5625
5626/**
5627 * ext4_swap_extents() - Swap extents between two inodes
5628 * @handle: handle for this transaction
5629 * @inode1: First inode
5630 * @inode2: Second inode
5631 * @lblk1: Start block for first inode
5632 * @lblk2: Start block for second inode
5633 * @count: Number of blocks to swap
5634 * @unwritten: Mark second inode's extents as unwritten after swap
5635 * @erp: Pointer to save error value
5636 *
5637 * This helper routine does exactly what is promise "swap extents". All other
5638 * stuff such as page-cache locking consistency, bh mapping consistency or
5639 * extent's data copying must be performed by caller.
5640 * Locking:
5641 * i_rwsem is held for both inodes
5642 * i_data_sem is locked for write for both inodes
5643 * Assumptions:
5644 * All pages from requested range are locked for both inodes
5645 */
5646int
5647ext4_swap_extents(handle_t *handle, struct inode *inode1,
5648 struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
5649 ext4_lblk_t count, int unwritten, int *erp)
5650{
5651 struct ext4_ext_path *path1 = NULL;
5652 struct ext4_ext_path *path2 = NULL;
5653 int replaced_count = 0;
5654
5655 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
5656 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
5657 BUG_ON(!inode_is_locked(inode1));
5658 BUG_ON(!inode_is_locked(inode2));
5659
5660 ext4_es_remove_extent(inode1, lblk1, count);
5661 ext4_es_remove_extent(inode2, lblk2, count);
5662
5663 while (count) {
5664 struct ext4_extent *ex1, *ex2, tmp_ex;
5665 ext4_lblk_t e1_blk, e2_blk;
5666 int e1_len, e2_len, len;
5667 int split = 0;
5668
5669 path1 = ext4_find_extent(inode1, lblk1, path1, EXT4_EX_NOCACHE);
5670 if (IS_ERR(path1)) {
5671 *erp = PTR_ERR(path1);
5672 goto errout;
5673 }
5674 path2 = ext4_find_extent(inode2, lblk2, path2, EXT4_EX_NOCACHE);
5675 if (IS_ERR(path2)) {
5676 *erp = PTR_ERR(path2);
5677 goto errout;
5678 }
5679 ex1 = path1[path1->p_depth].p_ext;
5680 ex2 = path2[path2->p_depth].p_ext;
5681 /* Do we have something to swap ? */
5682 if (unlikely(!ex2 || !ex1))
5683 goto errout;
5684
5685 e1_blk = le32_to_cpu(ex1->ee_block);
5686 e2_blk = le32_to_cpu(ex2->ee_block);
5687 e1_len = ext4_ext_get_actual_len(ex1);
5688 e2_len = ext4_ext_get_actual_len(ex2);
5689
5690 /* Hole handling */
5691 if (!in_range(lblk1, e1_blk, e1_len) ||
5692 !in_range(lblk2, e2_blk, e2_len)) {
5693 ext4_lblk_t next1, next2;
5694
5695 /* if hole after extent, then go to next extent */
5696 next1 = ext4_ext_next_allocated_block(path1);
5697 next2 = ext4_ext_next_allocated_block(path2);
5698 /* If hole before extent, then shift to that extent */
5699 if (e1_blk > lblk1)
5700 next1 = e1_blk;
5701 if (e2_blk > lblk2)
5702 next2 = e2_blk;
5703 /* Do we have something to swap */
5704 if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
5705 goto errout;
5706 /* Move to the rightest boundary */
5707 len = next1 - lblk1;
5708 if (len < next2 - lblk2)
5709 len = next2 - lblk2;
5710 if (len > count)
5711 len = count;
5712 lblk1 += len;
5713 lblk2 += len;
5714 count -= len;
5715 continue;
5716 }
5717
5718 /* Prepare left boundary */
5719 if (e1_blk < lblk1) {
5720 split = 1;
5721 path1 = ext4_force_split_extent_at(handle, inode1,
5722 path1, lblk1, 0);
5723 if (IS_ERR(path1)) {
5724 *erp = PTR_ERR(path1);
5725 goto errout;
5726 }
5727 }
5728 if (e2_blk < lblk2) {
5729 split = 1;
5730 path2 = ext4_force_split_extent_at(handle, inode2,
5731 path2, lblk2, 0);
5732 if (IS_ERR(path2)) {
5733 *erp = PTR_ERR(path2);
5734 goto errout;
5735 }
5736 }
5737 /* ext4_split_extent_at() may result in leaf extent split,
5738 * path must to be revalidated. */
5739 if (split)
5740 continue;
5741
5742 /* Prepare right boundary */
5743 len = count;
5744 if (len > e1_blk + e1_len - lblk1)
5745 len = e1_blk + e1_len - lblk1;
5746 if (len > e2_blk + e2_len - lblk2)
5747 len = e2_blk + e2_len - lblk2;
5748
5749 if (len != e1_len) {
5750 split = 1;
5751 path1 = ext4_force_split_extent_at(handle, inode1,
5752 path1, lblk1 + len, 0);
5753 if (IS_ERR(path1)) {
5754 *erp = PTR_ERR(path1);
5755 goto errout;
5756 }
5757 }
5758 if (len != e2_len) {
5759 split = 1;
5760 path2 = ext4_force_split_extent_at(handle, inode2,
5761 path2, lblk2 + len, 0);
5762 if (IS_ERR(path2)) {
5763 *erp = PTR_ERR(path2);
5764 goto errout;
5765 }
5766 }
5767 /* ext4_split_extent_at() may result in leaf extent split,
5768 * path must to be revalidated. */
5769 if (split)
5770 continue;
5771
5772 BUG_ON(e2_len != e1_len);
5773 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
5774 if (unlikely(*erp))
5775 goto errout;
5776 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
5777 if (unlikely(*erp))
5778 goto errout;
5779
5780 /* Both extents are fully inside boundaries. Swap it now */
5781 tmp_ex = *ex1;
5782 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
5783 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
5784 ex1->ee_len = cpu_to_le16(e2_len);
5785 ex2->ee_len = cpu_to_le16(e1_len);
5786 if (unwritten)
5787 ext4_ext_mark_unwritten(ex2);
5788 if (ext4_ext_is_unwritten(&tmp_ex))
5789 ext4_ext_mark_unwritten(ex1);
5790
5791 ext4_ext_try_to_merge(handle, inode2, path2, ex2);
5792 ext4_ext_try_to_merge(handle, inode1, path1, ex1);
5793 *erp = ext4_ext_dirty(handle, inode2, path2 +
5794 path2->p_depth);
5795 if (unlikely(*erp))
5796 goto errout;
5797 *erp = ext4_ext_dirty(handle, inode1, path1 +
5798 path1->p_depth);
5799 /*
5800 * Looks scarry ah..? second inode already points to new blocks,
5801 * and it was successfully dirtied. But luckily error may happen
5802 * only due to journal error, so full transaction will be
5803 * aborted anyway.
5804 */
5805 if (unlikely(*erp))
5806 goto errout;
5807
5808 lblk1 += len;
5809 lblk2 += len;
5810 replaced_count += len;
5811 count -= len;
5812 }
5813
5814errout:
5815 ext4_free_ext_path(path1);
5816 ext4_free_ext_path(path2);
5817 return replaced_count;
5818}
5819
5820/*
5821 * ext4_clu_mapped - determine whether any block in a logical cluster has
5822 * been mapped to a physical cluster
5823 *
5824 * @inode - file containing the logical cluster
5825 * @lclu - logical cluster of interest
5826 *
5827 * Returns 1 if any block in the logical cluster is mapped, signifying
5828 * that a physical cluster has been allocated for it. Otherwise,
5829 * returns 0. Can also return negative error codes. Derived from
5830 * ext4_ext_map_blocks().
5831 */
5832int ext4_clu_mapped(struct inode *inode, ext4_lblk_t lclu)
5833{
5834 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
5835 struct ext4_ext_path *path;
5836 int depth, mapped = 0, err = 0;
5837 struct ext4_extent *extent;
5838 ext4_lblk_t first_lblk, first_lclu, last_lclu;
5839
5840 /*
5841 * if data can be stored inline, the logical cluster isn't
5842 * mapped - no physical clusters have been allocated, and the
5843 * file has no extents
5844 */
5845 if (ext4_test_inode_state(inode, EXT4_STATE_MAY_INLINE_DATA) ||
5846 ext4_has_inline_data(inode))
5847 return 0;
5848
5849 /* search for the extent closest to the first block in the cluster */
5850 path = ext4_find_extent(inode, EXT4_C2B(sbi, lclu), NULL, 0);
5851 if (IS_ERR(path))
5852 return PTR_ERR(path);
5853
5854 depth = ext_depth(inode);
5855
5856 /*
5857 * A consistent leaf must not be empty. This situation is possible,
5858 * though, _during_ tree modification, and it's why an assert can't
5859 * be put in ext4_find_extent().
5860 */
5861 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
5862 EXT4_ERROR_INODE(inode,
5863 "bad extent address - lblock: %lu, depth: %d, pblock: %lld",
5864 (unsigned long) EXT4_C2B(sbi, lclu),
5865 depth, path[depth].p_block);
5866 err = -EFSCORRUPTED;
5867 goto out;
5868 }
5869
5870 extent = path[depth].p_ext;
5871
5872 /* can't be mapped if the extent tree is empty */
5873 if (extent == NULL)
5874 goto out;
5875
5876 first_lblk = le32_to_cpu(extent->ee_block);
5877 first_lclu = EXT4_B2C(sbi, first_lblk);
5878
5879 /*
5880 * Three possible outcomes at this point - found extent spanning
5881 * the target cluster, to the left of the target cluster, or to the
5882 * right of the target cluster. The first two cases are handled here.
5883 * The last case indicates the target cluster is not mapped.
5884 */
5885 if (lclu >= first_lclu) {
5886 last_lclu = EXT4_B2C(sbi, first_lblk +
5887 ext4_ext_get_actual_len(extent) - 1);
5888 if (lclu <= last_lclu) {
5889 mapped = 1;
5890 } else {
5891 first_lblk = ext4_ext_next_allocated_block(path);
5892 first_lclu = EXT4_B2C(sbi, first_lblk);
5893 if (lclu == first_lclu)
5894 mapped = 1;
5895 }
5896 }
5897
5898out:
5899 ext4_free_ext_path(path);
5900
5901 return err ? err : mapped;
5902}
5903
5904/*
5905 * Updates physical block address and unwritten status of extent
5906 * starting at lblk start and of len. If such an extent doesn't exist,
5907 * this function splits the extent tree appropriately to create an
5908 * extent like this. This function is called in the fast commit
5909 * replay path. Returns 0 on success and error on failure.
5910 */
5911int ext4_ext_replay_update_ex(struct inode *inode, ext4_lblk_t start,
5912 int len, int unwritten, ext4_fsblk_t pblk)
5913{
5914 struct ext4_ext_path *path;
5915 struct ext4_extent *ex;
5916 int ret;
5917
5918 path = ext4_find_extent(inode, start, NULL, 0);
5919 if (IS_ERR(path))
5920 return PTR_ERR(path);
5921 ex = path[path->p_depth].p_ext;
5922 if (!ex) {
5923 ret = -EFSCORRUPTED;
5924 goto out;
5925 }
5926
5927 if (le32_to_cpu(ex->ee_block) != start ||
5928 ext4_ext_get_actual_len(ex) != len) {
5929 /* We need to split this extent to match our extent first */
5930 down_write(&EXT4_I(inode)->i_data_sem);
5931 path = ext4_force_split_extent_at(NULL, inode, path, start, 1);
5932 up_write(&EXT4_I(inode)->i_data_sem);
5933 if (IS_ERR(path)) {
5934 ret = PTR_ERR(path);
5935 goto out;
5936 }
5937
5938 path = ext4_find_extent(inode, start, path, 0);
5939 if (IS_ERR(path))
5940 return PTR_ERR(path);
5941
5942 ex = path[path->p_depth].p_ext;
5943 WARN_ON(le32_to_cpu(ex->ee_block) != start);
5944
5945 if (ext4_ext_get_actual_len(ex) != len) {
5946 down_write(&EXT4_I(inode)->i_data_sem);
5947 path = ext4_force_split_extent_at(NULL, inode, path,
5948 start + len, 1);
5949 up_write(&EXT4_I(inode)->i_data_sem);
5950 if (IS_ERR(path)) {
5951 ret = PTR_ERR(path);
5952 goto out;
5953 }
5954
5955 path = ext4_find_extent(inode, start, path, 0);
5956 if (IS_ERR(path))
5957 return PTR_ERR(path);
5958 ex = path[path->p_depth].p_ext;
5959 }
5960 }
5961 if (unwritten)
5962 ext4_ext_mark_unwritten(ex);
5963 else
5964 ext4_ext_mark_initialized(ex);
5965 ext4_ext_store_pblock(ex, pblk);
5966 down_write(&EXT4_I(inode)->i_data_sem);
5967 ret = ext4_ext_dirty(NULL, inode, &path[path->p_depth]);
5968 up_write(&EXT4_I(inode)->i_data_sem);
5969out:
5970 ext4_free_ext_path(path);
5971 ext4_mark_inode_dirty(NULL, inode);
5972 return ret;
5973}
5974
5975/* Try to shrink the extent tree */
5976void ext4_ext_replay_shrink_inode(struct inode *inode, ext4_lblk_t end)
5977{
5978 struct ext4_ext_path *path = NULL;
5979 struct ext4_extent *ex;
5980 ext4_lblk_t old_cur, cur = 0;
5981
5982 while (cur < end) {
5983 path = ext4_find_extent(inode, cur, NULL, 0);
5984 if (IS_ERR(path))
5985 return;
5986 ex = path[path->p_depth].p_ext;
5987 if (!ex) {
5988 ext4_free_ext_path(path);
5989 ext4_mark_inode_dirty(NULL, inode);
5990 return;
5991 }
5992 old_cur = cur;
5993 cur = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
5994 if (cur <= old_cur)
5995 cur = old_cur + 1;
5996 ext4_ext_try_to_merge(NULL, inode, path, ex);
5997 down_write(&EXT4_I(inode)->i_data_sem);
5998 ext4_ext_dirty(NULL, inode, &path[path->p_depth]);
5999 up_write(&EXT4_I(inode)->i_data_sem);
6000 ext4_mark_inode_dirty(NULL, inode);
6001 ext4_free_ext_path(path);
6002 }
6003}
6004
6005/* Check if *cur is a hole and if it is, skip it */
6006static int skip_hole(struct inode *inode, ext4_lblk_t *cur)
6007{
6008 int ret;
6009 struct ext4_map_blocks map;
6010
6011 map.m_lblk = *cur;
6012 map.m_len = ((inode->i_size) >> inode->i_sb->s_blocksize_bits) - *cur;
6013
6014 ret = ext4_map_blocks(NULL, inode, &map, 0);
6015 if (ret < 0)
6016 return ret;
6017 if (ret != 0)
6018 return 0;
6019 *cur = *cur + map.m_len;
6020 return 0;
6021}
6022
6023/* Count number of blocks used by this inode and update i_blocks */
6024int ext4_ext_replay_set_iblocks(struct inode *inode)
6025{
6026 struct ext4_ext_path *path = NULL, *path2 = NULL;
6027 struct ext4_extent *ex;
6028 ext4_lblk_t cur = 0, end;
6029 int numblks = 0, i, ret = 0;
6030 ext4_fsblk_t cmp1, cmp2;
6031 struct ext4_map_blocks map;
6032
6033 /* Determin the size of the file first */
6034 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
6035 EXT4_EX_NOCACHE);
6036 if (IS_ERR(path))
6037 return PTR_ERR(path);
6038 ex = path[path->p_depth].p_ext;
6039 if (!ex)
6040 goto out;
6041 end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
6042
6043 /* Count the number of data blocks */
6044 cur = 0;
6045 while (cur < end) {
6046 map.m_lblk = cur;
6047 map.m_len = end - cur;
6048 ret = ext4_map_blocks(NULL, inode, &map, 0);
6049 if (ret < 0)
6050 break;
6051 if (ret > 0)
6052 numblks += ret;
6053 cur = cur + map.m_len;
6054 }
6055
6056 /*
6057 * Count the number of extent tree blocks. We do it by looking up
6058 * two successive extents and determining the difference between
6059 * their paths. When path is different for 2 successive extents
6060 * we compare the blocks in the path at each level and increment
6061 * iblocks by total number of differences found.
6062 */
6063 cur = 0;
6064 ret = skip_hole(inode, &cur);
6065 if (ret < 0)
6066 goto out;
6067 path = ext4_find_extent(inode, cur, path, 0);
6068 if (IS_ERR(path))
6069 goto out;
6070 numblks += path->p_depth;
6071 while (cur < end) {
6072 path = ext4_find_extent(inode, cur, path, 0);
6073 if (IS_ERR(path))
6074 break;
6075 ex = path[path->p_depth].p_ext;
6076 if (!ex)
6077 goto cleanup;
6078
6079 cur = max(cur + 1, le32_to_cpu(ex->ee_block) +
6080 ext4_ext_get_actual_len(ex));
6081 ret = skip_hole(inode, &cur);
6082 if (ret < 0)
6083 break;
6084
6085 path2 = ext4_find_extent(inode, cur, path2, 0);
6086 if (IS_ERR(path2))
6087 break;
6088
6089 for (i = 0; i <= max(path->p_depth, path2->p_depth); i++) {
6090 cmp1 = cmp2 = 0;
6091 if (i <= path->p_depth)
6092 cmp1 = path[i].p_bh ?
6093 path[i].p_bh->b_blocknr : 0;
6094 if (i <= path2->p_depth)
6095 cmp2 = path2[i].p_bh ?
6096 path2[i].p_bh->b_blocknr : 0;
6097 if (cmp1 != cmp2 && cmp2 != 0)
6098 numblks++;
6099 }
6100 }
6101
6102out:
6103 inode->i_blocks = numblks << (inode->i_sb->s_blocksize_bits - 9);
6104 ext4_mark_inode_dirty(NULL, inode);
6105cleanup:
6106 ext4_free_ext_path(path);
6107 ext4_free_ext_path(path2);
6108 return 0;
6109}
6110
6111int ext4_ext_clear_bb(struct inode *inode)
6112{
6113 struct ext4_ext_path *path = NULL;
6114 struct ext4_extent *ex;
6115 ext4_lblk_t cur = 0, end;
6116 int j, ret = 0;
6117 struct ext4_map_blocks map;
6118
6119 if (ext4_test_inode_flag(inode, EXT4_INODE_INLINE_DATA))
6120 return 0;
6121
6122 /* Determin the size of the file first */
6123 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
6124 EXT4_EX_NOCACHE);
6125 if (IS_ERR(path))
6126 return PTR_ERR(path);
6127 ex = path[path->p_depth].p_ext;
6128 if (!ex)
6129 goto out;
6130 end = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
6131
6132 cur = 0;
6133 while (cur < end) {
6134 map.m_lblk = cur;
6135 map.m_len = end - cur;
6136 ret = ext4_map_blocks(NULL, inode, &map, 0);
6137 if (ret < 0)
6138 break;
6139 if (ret > 0) {
6140 path = ext4_find_extent(inode, map.m_lblk, path, 0);
6141 if (!IS_ERR(path)) {
6142 for (j = 0; j < path->p_depth; j++) {
6143 ext4_mb_mark_bb(inode->i_sb,
6144 path[j].p_block, 1, false);
6145 ext4_fc_record_regions(inode->i_sb, inode->i_ino,
6146 0, path[j].p_block, 1, 1);
6147 }
6148 } else {
6149 path = NULL;
6150 }
6151 ext4_mb_mark_bb(inode->i_sb, map.m_pblk, map.m_len, false);
6152 ext4_fc_record_regions(inode->i_sb, inode->i_ino,
6153 map.m_lblk, map.m_pblk, map.m_len, 1);
6154 }
6155 cur = cur + map.m_len;
6156 }
6157
6158out:
6159 ext4_free_ext_path(path);
6160 return 0;
6161}