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1/*
2 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
3 * Written by Alex Tomas <alex@clusterfs.com>
4 *
5 * Architecture independence:
6 * Copyright (c) 2005, Bull S.A.
7 * Written by Pierre Peiffer <pierre.peiffer@bull.net>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
21 */
22
23/*
24 * Extents support for EXT4
25 *
26 * TODO:
27 * - ext4*_error() should be used in some situations
28 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
29 * - smart tree reduction
30 */
31
32#include <linux/fs.h>
33#include <linux/time.h>
34#include <linux/jbd2.h>
35#include <linux/highuid.h>
36#include <linux/pagemap.h>
37#include <linux/quotaops.h>
38#include <linux/string.h>
39#include <linux/slab.h>
40#include <linux/uaccess.h>
41#include <linux/fiemap.h>
42#include <linux/backing-dev.h>
43#include "ext4_jbd2.h"
44#include "ext4_extents.h"
45#include "xattr.h"
46
47#include <trace/events/ext4.h>
48
49/*
50 * used by extent splitting.
51 */
52#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
53 due to ENOSPC */
54#define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */
55#define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */
56
57#define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
58#define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
59
60static __le32 ext4_extent_block_csum(struct inode *inode,
61 struct ext4_extent_header *eh)
62{
63 struct ext4_inode_info *ei = EXT4_I(inode);
64 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
65 __u32 csum;
66
67 csum = ext4_chksum(sbi, ei->i_csum_seed, (__u8 *)eh,
68 EXT4_EXTENT_TAIL_OFFSET(eh));
69 return cpu_to_le32(csum);
70}
71
72static int ext4_extent_block_csum_verify(struct inode *inode,
73 struct ext4_extent_header *eh)
74{
75 struct ext4_extent_tail *et;
76
77 if (!ext4_has_metadata_csum(inode->i_sb))
78 return 1;
79
80 et = find_ext4_extent_tail(eh);
81 if (et->et_checksum != ext4_extent_block_csum(inode, eh))
82 return 0;
83 return 1;
84}
85
86static void ext4_extent_block_csum_set(struct inode *inode,
87 struct ext4_extent_header *eh)
88{
89 struct ext4_extent_tail *et;
90
91 if (!ext4_has_metadata_csum(inode->i_sb))
92 return;
93
94 et = find_ext4_extent_tail(eh);
95 et->et_checksum = ext4_extent_block_csum(inode, eh);
96}
97
98static int ext4_split_extent(handle_t *handle,
99 struct inode *inode,
100 struct ext4_ext_path **ppath,
101 struct ext4_map_blocks *map,
102 int split_flag,
103 int flags);
104
105static int ext4_split_extent_at(handle_t *handle,
106 struct inode *inode,
107 struct ext4_ext_path **ppath,
108 ext4_lblk_t split,
109 int split_flag,
110 int flags);
111
112static int ext4_find_delayed_extent(struct inode *inode,
113 struct extent_status *newes);
114
115static int ext4_ext_truncate_extend_restart(handle_t *handle,
116 struct inode *inode,
117 int needed)
118{
119 int err;
120
121 if (!ext4_handle_valid(handle))
122 return 0;
123 if (handle->h_buffer_credits >= needed)
124 return 0;
125 /*
126 * If we need to extend the journal get a few extra blocks
127 * while we're at it for efficiency's sake.
128 */
129 needed += 3;
130 err = ext4_journal_extend(handle, needed - handle->h_buffer_credits);
131 if (err <= 0)
132 return err;
133 err = ext4_truncate_restart_trans(handle, inode, needed);
134 if (err == 0)
135 err = -EAGAIN;
136
137 return err;
138}
139
140/*
141 * could return:
142 * - EROFS
143 * - ENOMEM
144 */
145static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
146 struct ext4_ext_path *path)
147{
148 if (path->p_bh) {
149 /* path points to block */
150 BUFFER_TRACE(path->p_bh, "get_write_access");
151 return ext4_journal_get_write_access(handle, path->p_bh);
152 }
153 /* path points to leaf/index in inode body */
154 /* we use in-core data, no need to protect them */
155 return 0;
156}
157
158/*
159 * could return:
160 * - EROFS
161 * - ENOMEM
162 * - EIO
163 */
164int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle,
165 struct inode *inode, struct ext4_ext_path *path)
166{
167 int err;
168
169 WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
170 if (path->p_bh) {
171 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
172 /* path points to block */
173 err = __ext4_handle_dirty_metadata(where, line, handle,
174 inode, path->p_bh);
175 } else {
176 /* path points to leaf/index in inode body */
177 err = ext4_mark_inode_dirty(handle, inode);
178 }
179 return err;
180}
181
182static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
183 struct ext4_ext_path *path,
184 ext4_lblk_t block)
185{
186 if (path) {
187 int depth = path->p_depth;
188 struct ext4_extent *ex;
189
190 /*
191 * Try to predict block placement assuming that we are
192 * filling in a file which will eventually be
193 * non-sparse --- i.e., in the case of libbfd writing
194 * an ELF object sections out-of-order but in a way
195 * the eventually results in a contiguous object or
196 * executable file, or some database extending a table
197 * space file. However, this is actually somewhat
198 * non-ideal if we are writing a sparse file such as
199 * qemu or KVM writing a raw image file that is going
200 * to stay fairly sparse, since it will end up
201 * fragmenting the file system's free space. Maybe we
202 * should have some hueristics or some way to allow
203 * userspace to pass a hint to file system,
204 * especially if the latter case turns out to be
205 * common.
206 */
207 ex = path[depth].p_ext;
208 if (ex) {
209 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
210 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
211
212 if (block > ext_block)
213 return ext_pblk + (block - ext_block);
214 else
215 return ext_pblk - (ext_block - block);
216 }
217
218 /* it looks like index is empty;
219 * try to find starting block from index itself */
220 if (path[depth].p_bh)
221 return path[depth].p_bh->b_blocknr;
222 }
223
224 /* OK. use inode's group */
225 return ext4_inode_to_goal_block(inode);
226}
227
228/*
229 * Allocation for a meta data block
230 */
231static ext4_fsblk_t
232ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
233 struct ext4_ext_path *path,
234 struct ext4_extent *ex, int *err, unsigned int flags)
235{
236 ext4_fsblk_t goal, newblock;
237
238 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
239 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
240 NULL, err);
241 return newblock;
242}
243
244static inline int ext4_ext_space_block(struct inode *inode, int check)
245{
246 int size;
247
248 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
249 / sizeof(struct ext4_extent);
250#ifdef AGGRESSIVE_TEST
251 if (!check && size > 6)
252 size = 6;
253#endif
254 return size;
255}
256
257static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
258{
259 int size;
260
261 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
262 / sizeof(struct ext4_extent_idx);
263#ifdef AGGRESSIVE_TEST
264 if (!check && size > 5)
265 size = 5;
266#endif
267 return size;
268}
269
270static inline int ext4_ext_space_root(struct inode *inode, int check)
271{
272 int size;
273
274 size = sizeof(EXT4_I(inode)->i_data);
275 size -= sizeof(struct ext4_extent_header);
276 size /= sizeof(struct ext4_extent);
277#ifdef AGGRESSIVE_TEST
278 if (!check && size > 3)
279 size = 3;
280#endif
281 return size;
282}
283
284static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
285{
286 int size;
287
288 size = sizeof(EXT4_I(inode)->i_data);
289 size -= sizeof(struct ext4_extent_header);
290 size /= sizeof(struct ext4_extent_idx);
291#ifdef AGGRESSIVE_TEST
292 if (!check && size > 4)
293 size = 4;
294#endif
295 return size;
296}
297
298static inline int
299ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
300 struct ext4_ext_path **ppath, ext4_lblk_t lblk,
301 int nofail)
302{
303 struct ext4_ext_path *path = *ppath;
304 int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
305
306 return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ?
307 EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
308 EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO |
309 (nofail ? EXT4_GET_BLOCKS_METADATA_NOFAIL:0));
310}
311
312/*
313 * Calculate the number of metadata blocks needed
314 * to allocate @blocks
315 * Worse case is one block per extent
316 */
317int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
318{
319 struct ext4_inode_info *ei = EXT4_I(inode);
320 int idxs;
321
322 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
323 / sizeof(struct ext4_extent_idx));
324
325 /*
326 * If the new delayed allocation block is contiguous with the
327 * previous da block, it can share index blocks with the
328 * previous block, so we only need to allocate a new index
329 * block every idxs leaf blocks. At ldxs**2 blocks, we need
330 * an additional index block, and at ldxs**3 blocks, yet
331 * another index blocks.
332 */
333 if (ei->i_da_metadata_calc_len &&
334 ei->i_da_metadata_calc_last_lblock+1 == lblock) {
335 int num = 0;
336
337 if ((ei->i_da_metadata_calc_len % idxs) == 0)
338 num++;
339 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
340 num++;
341 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
342 num++;
343 ei->i_da_metadata_calc_len = 0;
344 } else
345 ei->i_da_metadata_calc_len++;
346 ei->i_da_metadata_calc_last_lblock++;
347 return num;
348 }
349
350 /*
351 * In the worst case we need a new set of index blocks at
352 * every level of the inode's extent tree.
353 */
354 ei->i_da_metadata_calc_len = 1;
355 ei->i_da_metadata_calc_last_lblock = lblock;
356 return ext_depth(inode) + 1;
357}
358
359static int
360ext4_ext_max_entries(struct inode *inode, int depth)
361{
362 int max;
363
364 if (depth == ext_depth(inode)) {
365 if (depth == 0)
366 max = ext4_ext_space_root(inode, 1);
367 else
368 max = ext4_ext_space_root_idx(inode, 1);
369 } else {
370 if (depth == 0)
371 max = ext4_ext_space_block(inode, 1);
372 else
373 max = ext4_ext_space_block_idx(inode, 1);
374 }
375
376 return max;
377}
378
379static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
380{
381 ext4_fsblk_t block = ext4_ext_pblock(ext);
382 int len = ext4_ext_get_actual_len(ext);
383 ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
384
385 /*
386 * We allow neither:
387 * - zero length
388 * - overflow/wrap-around
389 */
390 if (lblock + len <= lblock)
391 return 0;
392 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
393}
394
395static int ext4_valid_extent_idx(struct inode *inode,
396 struct ext4_extent_idx *ext_idx)
397{
398 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
399
400 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
401}
402
403static int ext4_valid_extent_entries(struct inode *inode,
404 struct ext4_extent_header *eh,
405 int depth)
406{
407 unsigned short entries;
408 if (eh->eh_entries == 0)
409 return 1;
410
411 entries = le16_to_cpu(eh->eh_entries);
412
413 if (depth == 0) {
414 /* leaf entries */
415 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
416 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
417 ext4_fsblk_t pblock = 0;
418 ext4_lblk_t lblock = 0;
419 ext4_lblk_t prev = 0;
420 int len = 0;
421 while (entries) {
422 if (!ext4_valid_extent(inode, ext))
423 return 0;
424
425 /* Check for overlapping extents */
426 lblock = le32_to_cpu(ext->ee_block);
427 len = ext4_ext_get_actual_len(ext);
428 if ((lblock <= prev) && prev) {
429 pblock = ext4_ext_pblock(ext);
430 es->s_last_error_block = cpu_to_le64(pblock);
431 return 0;
432 }
433 ext++;
434 entries--;
435 prev = lblock + len - 1;
436 }
437 } else {
438 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
439 while (entries) {
440 if (!ext4_valid_extent_idx(inode, ext_idx))
441 return 0;
442 ext_idx++;
443 entries--;
444 }
445 }
446 return 1;
447}
448
449static int __ext4_ext_check(const char *function, unsigned int line,
450 struct inode *inode, struct ext4_extent_header *eh,
451 int depth, ext4_fsblk_t pblk)
452{
453 const char *error_msg;
454 int max = 0, err = -EFSCORRUPTED;
455
456 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
457 error_msg = "invalid magic";
458 goto corrupted;
459 }
460 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
461 error_msg = "unexpected eh_depth";
462 goto corrupted;
463 }
464 if (unlikely(eh->eh_max == 0)) {
465 error_msg = "invalid eh_max";
466 goto corrupted;
467 }
468 max = ext4_ext_max_entries(inode, depth);
469 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
470 error_msg = "too large eh_max";
471 goto corrupted;
472 }
473 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
474 error_msg = "invalid eh_entries";
475 goto corrupted;
476 }
477 if (!ext4_valid_extent_entries(inode, eh, depth)) {
478 error_msg = "invalid extent entries";
479 goto corrupted;
480 }
481 if (unlikely(depth > 32)) {
482 error_msg = "too large eh_depth";
483 goto corrupted;
484 }
485 /* Verify checksum on non-root extent tree nodes */
486 if (ext_depth(inode) != depth &&
487 !ext4_extent_block_csum_verify(inode, eh)) {
488 error_msg = "extent tree corrupted";
489 err = -EFSBADCRC;
490 goto corrupted;
491 }
492 return 0;
493
494corrupted:
495 ext4_error_inode(inode, function, line, 0,
496 "pblk %llu bad header/extent: %s - magic %x, "
497 "entries %u, max %u(%u), depth %u(%u)",
498 (unsigned long long) pblk, error_msg,
499 le16_to_cpu(eh->eh_magic),
500 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
501 max, le16_to_cpu(eh->eh_depth), depth);
502 return err;
503}
504
505#define ext4_ext_check(inode, eh, depth, pblk) \
506 __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk))
507
508int ext4_ext_check_inode(struct inode *inode)
509{
510 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
511}
512
513static struct buffer_head *
514__read_extent_tree_block(const char *function, unsigned int line,
515 struct inode *inode, ext4_fsblk_t pblk, int depth,
516 int flags)
517{
518 struct buffer_head *bh;
519 int err;
520
521 bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
522 if (unlikely(!bh))
523 return ERR_PTR(-ENOMEM);
524
525 if (!bh_uptodate_or_lock(bh)) {
526 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
527 err = bh_submit_read(bh);
528 if (err < 0)
529 goto errout;
530 }
531 if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
532 return bh;
533 err = __ext4_ext_check(function, line, inode,
534 ext_block_hdr(bh), depth, pblk);
535 if (err)
536 goto errout;
537 set_buffer_verified(bh);
538 /*
539 * If this is a leaf block, cache all of its entries
540 */
541 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
542 struct ext4_extent_header *eh = ext_block_hdr(bh);
543 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
544 ext4_lblk_t prev = 0;
545 int i;
546
547 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
548 unsigned int status = EXTENT_STATUS_WRITTEN;
549 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
550 int len = ext4_ext_get_actual_len(ex);
551
552 if (prev && (prev != lblk))
553 ext4_es_cache_extent(inode, prev,
554 lblk - prev, ~0,
555 EXTENT_STATUS_HOLE);
556
557 if (ext4_ext_is_unwritten(ex))
558 status = EXTENT_STATUS_UNWRITTEN;
559 ext4_es_cache_extent(inode, lblk, len,
560 ext4_ext_pblock(ex), status);
561 prev = lblk + len;
562 }
563 }
564 return bh;
565errout:
566 put_bh(bh);
567 return ERR_PTR(err);
568
569}
570
571#define read_extent_tree_block(inode, pblk, depth, flags) \
572 __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \
573 (depth), (flags))
574
575/*
576 * This function is called to cache a file's extent information in the
577 * extent status tree
578 */
579int ext4_ext_precache(struct inode *inode)
580{
581 struct ext4_inode_info *ei = EXT4_I(inode);
582 struct ext4_ext_path *path = NULL;
583 struct buffer_head *bh;
584 int i = 0, depth, ret = 0;
585
586 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
587 return 0; /* not an extent-mapped inode */
588
589 down_read(&ei->i_data_sem);
590 depth = ext_depth(inode);
591
592 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
593 GFP_NOFS);
594 if (path == NULL) {
595 up_read(&ei->i_data_sem);
596 return -ENOMEM;
597 }
598
599 /* Don't cache anything if there are no external extent blocks */
600 if (depth == 0)
601 goto out;
602 path[0].p_hdr = ext_inode_hdr(inode);
603 ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
604 if (ret)
605 goto out;
606 path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
607 while (i >= 0) {
608 /*
609 * If this is a leaf block or we've reached the end of
610 * the index block, go up
611 */
612 if ((i == depth) ||
613 path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
614 brelse(path[i].p_bh);
615 path[i].p_bh = NULL;
616 i--;
617 continue;
618 }
619 bh = read_extent_tree_block(inode,
620 ext4_idx_pblock(path[i].p_idx++),
621 depth - i - 1,
622 EXT4_EX_FORCE_CACHE);
623 if (IS_ERR(bh)) {
624 ret = PTR_ERR(bh);
625 break;
626 }
627 i++;
628 path[i].p_bh = bh;
629 path[i].p_hdr = ext_block_hdr(bh);
630 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
631 }
632 ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
633out:
634 up_read(&ei->i_data_sem);
635 ext4_ext_drop_refs(path);
636 kfree(path);
637 return ret;
638}
639
640#ifdef EXT_DEBUG
641static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
642{
643 int k, l = path->p_depth;
644
645 ext_debug("path:");
646 for (k = 0; k <= l; k++, path++) {
647 if (path->p_idx) {
648 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
649 ext4_idx_pblock(path->p_idx));
650 } else if (path->p_ext) {
651 ext_debug(" %d:[%d]%d:%llu ",
652 le32_to_cpu(path->p_ext->ee_block),
653 ext4_ext_is_unwritten(path->p_ext),
654 ext4_ext_get_actual_len(path->p_ext),
655 ext4_ext_pblock(path->p_ext));
656 } else
657 ext_debug(" []");
658 }
659 ext_debug("\n");
660}
661
662static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
663{
664 int depth = ext_depth(inode);
665 struct ext4_extent_header *eh;
666 struct ext4_extent *ex;
667 int i;
668
669 if (!path)
670 return;
671
672 eh = path[depth].p_hdr;
673 ex = EXT_FIRST_EXTENT(eh);
674
675 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
676
677 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
678 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
679 ext4_ext_is_unwritten(ex),
680 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
681 }
682 ext_debug("\n");
683}
684
685static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
686 ext4_fsblk_t newblock, int level)
687{
688 int depth = ext_depth(inode);
689 struct ext4_extent *ex;
690
691 if (depth != level) {
692 struct ext4_extent_idx *idx;
693 idx = path[level].p_idx;
694 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
695 ext_debug("%d: move %d:%llu in new index %llu\n", level,
696 le32_to_cpu(idx->ei_block),
697 ext4_idx_pblock(idx),
698 newblock);
699 idx++;
700 }
701
702 return;
703 }
704
705 ex = path[depth].p_ext;
706 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
707 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
708 le32_to_cpu(ex->ee_block),
709 ext4_ext_pblock(ex),
710 ext4_ext_is_unwritten(ex),
711 ext4_ext_get_actual_len(ex),
712 newblock);
713 ex++;
714 }
715}
716
717#else
718#define ext4_ext_show_path(inode, path)
719#define ext4_ext_show_leaf(inode, path)
720#define ext4_ext_show_move(inode, path, newblock, level)
721#endif
722
723void ext4_ext_drop_refs(struct ext4_ext_path *path)
724{
725 int depth, i;
726
727 if (!path)
728 return;
729 depth = path->p_depth;
730 for (i = 0; i <= depth; i++, path++)
731 if (path->p_bh) {
732 brelse(path->p_bh);
733 path->p_bh = NULL;
734 }
735}
736
737/*
738 * ext4_ext_binsearch_idx:
739 * binary search for the closest index of the given block
740 * the header must be checked before calling this
741 */
742static void
743ext4_ext_binsearch_idx(struct inode *inode,
744 struct ext4_ext_path *path, ext4_lblk_t block)
745{
746 struct ext4_extent_header *eh = path->p_hdr;
747 struct ext4_extent_idx *r, *l, *m;
748
749
750 ext_debug("binsearch for %u(idx): ", block);
751
752 l = EXT_FIRST_INDEX(eh) + 1;
753 r = EXT_LAST_INDEX(eh);
754 while (l <= r) {
755 m = l + (r - l) / 2;
756 if (block < le32_to_cpu(m->ei_block))
757 r = m - 1;
758 else
759 l = m + 1;
760 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
761 m, le32_to_cpu(m->ei_block),
762 r, le32_to_cpu(r->ei_block));
763 }
764
765 path->p_idx = l - 1;
766 ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
767 ext4_idx_pblock(path->p_idx));
768
769#ifdef CHECK_BINSEARCH
770 {
771 struct ext4_extent_idx *chix, *ix;
772 int k;
773
774 chix = ix = EXT_FIRST_INDEX(eh);
775 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
776 if (k != 0 &&
777 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
778 printk(KERN_DEBUG "k=%d, ix=0x%p, "
779 "first=0x%p\n", k,
780 ix, EXT_FIRST_INDEX(eh));
781 printk(KERN_DEBUG "%u <= %u\n",
782 le32_to_cpu(ix->ei_block),
783 le32_to_cpu(ix[-1].ei_block));
784 }
785 BUG_ON(k && le32_to_cpu(ix->ei_block)
786 <= le32_to_cpu(ix[-1].ei_block));
787 if (block < le32_to_cpu(ix->ei_block))
788 break;
789 chix = ix;
790 }
791 BUG_ON(chix != path->p_idx);
792 }
793#endif
794
795}
796
797/*
798 * ext4_ext_binsearch:
799 * binary search for closest extent of the given block
800 * the header must be checked before calling this
801 */
802static void
803ext4_ext_binsearch(struct inode *inode,
804 struct ext4_ext_path *path, ext4_lblk_t block)
805{
806 struct ext4_extent_header *eh = path->p_hdr;
807 struct ext4_extent *r, *l, *m;
808
809 if (eh->eh_entries == 0) {
810 /*
811 * this leaf is empty:
812 * we get such a leaf in split/add case
813 */
814 return;
815 }
816
817 ext_debug("binsearch for %u: ", block);
818
819 l = EXT_FIRST_EXTENT(eh) + 1;
820 r = EXT_LAST_EXTENT(eh);
821
822 while (l <= r) {
823 m = l + (r - l) / 2;
824 if (block < le32_to_cpu(m->ee_block))
825 r = m - 1;
826 else
827 l = m + 1;
828 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
829 m, le32_to_cpu(m->ee_block),
830 r, le32_to_cpu(r->ee_block));
831 }
832
833 path->p_ext = l - 1;
834 ext_debug(" -> %d:%llu:[%d]%d ",
835 le32_to_cpu(path->p_ext->ee_block),
836 ext4_ext_pblock(path->p_ext),
837 ext4_ext_is_unwritten(path->p_ext),
838 ext4_ext_get_actual_len(path->p_ext));
839
840#ifdef CHECK_BINSEARCH
841 {
842 struct ext4_extent *chex, *ex;
843 int k;
844
845 chex = ex = EXT_FIRST_EXTENT(eh);
846 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
847 BUG_ON(k && le32_to_cpu(ex->ee_block)
848 <= le32_to_cpu(ex[-1].ee_block));
849 if (block < le32_to_cpu(ex->ee_block))
850 break;
851 chex = ex;
852 }
853 BUG_ON(chex != path->p_ext);
854 }
855#endif
856
857}
858
859int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
860{
861 struct ext4_extent_header *eh;
862
863 eh = ext_inode_hdr(inode);
864 eh->eh_depth = 0;
865 eh->eh_entries = 0;
866 eh->eh_magic = EXT4_EXT_MAGIC;
867 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
868 ext4_mark_inode_dirty(handle, inode);
869 return 0;
870}
871
872struct ext4_ext_path *
873ext4_find_extent(struct inode *inode, ext4_lblk_t block,
874 struct ext4_ext_path **orig_path, int flags)
875{
876 struct ext4_extent_header *eh;
877 struct buffer_head *bh;
878 struct ext4_ext_path *path = orig_path ? *orig_path : NULL;
879 short int depth, i, ppos = 0;
880 int ret;
881
882 eh = ext_inode_hdr(inode);
883 depth = ext_depth(inode);
884
885 if (path) {
886 ext4_ext_drop_refs(path);
887 if (depth > path[0].p_maxdepth) {
888 kfree(path);
889 *orig_path = path = NULL;
890 }
891 }
892 if (!path) {
893 /* account possible depth increase */
894 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
895 GFP_NOFS);
896 if (unlikely(!path))
897 return ERR_PTR(-ENOMEM);
898 path[0].p_maxdepth = depth + 1;
899 }
900 path[0].p_hdr = eh;
901 path[0].p_bh = NULL;
902
903 i = depth;
904 /* walk through the tree */
905 while (i) {
906 ext_debug("depth %d: num %d, max %d\n",
907 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
908
909 ext4_ext_binsearch_idx(inode, path + ppos, block);
910 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
911 path[ppos].p_depth = i;
912 path[ppos].p_ext = NULL;
913
914 bh = read_extent_tree_block(inode, path[ppos].p_block, --i,
915 flags);
916 if (IS_ERR(bh)) {
917 ret = PTR_ERR(bh);
918 goto err;
919 }
920
921 eh = ext_block_hdr(bh);
922 ppos++;
923 path[ppos].p_bh = bh;
924 path[ppos].p_hdr = eh;
925 }
926
927 path[ppos].p_depth = i;
928 path[ppos].p_ext = NULL;
929 path[ppos].p_idx = NULL;
930
931 /* find extent */
932 ext4_ext_binsearch(inode, path + ppos, block);
933 /* if not an empty leaf */
934 if (path[ppos].p_ext)
935 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
936
937 ext4_ext_show_path(inode, path);
938
939 return path;
940
941err:
942 ext4_ext_drop_refs(path);
943 kfree(path);
944 if (orig_path)
945 *orig_path = NULL;
946 return ERR_PTR(ret);
947}
948
949/*
950 * ext4_ext_insert_index:
951 * insert new index [@logical;@ptr] into the block at @curp;
952 * check where to insert: before @curp or after @curp
953 */
954static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
955 struct ext4_ext_path *curp,
956 int logical, ext4_fsblk_t ptr)
957{
958 struct ext4_extent_idx *ix;
959 int len, err;
960
961 err = ext4_ext_get_access(handle, inode, curp);
962 if (err)
963 return err;
964
965 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
966 EXT4_ERROR_INODE(inode,
967 "logical %d == ei_block %d!",
968 logical, le32_to_cpu(curp->p_idx->ei_block));
969 return -EFSCORRUPTED;
970 }
971
972 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
973 >= le16_to_cpu(curp->p_hdr->eh_max))) {
974 EXT4_ERROR_INODE(inode,
975 "eh_entries %d >= eh_max %d!",
976 le16_to_cpu(curp->p_hdr->eh_entries),
977 le16_to_cpu(curp->p_hdr->eh_max));
978 return -EFSCORRUPTED;
979 }
980
981 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
982 /* insert after */
983 ext_debug("insert new index %d after: %llu\n", logical, ptr);
984 ix = curp->p_idx + 1;
985 } else {
986 /* insert before */
987 ext_debug("insert new index %d before: %llu\n", logical, ptr);
988 ix = curp->p_idx;
989 }
990
991 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
992 BUG_ON(len < 0);
993 if (len > 0) {
994 ext_debug("insert new index %d: "
995 "move %d indices from 0x%p to 0x%p\n",
996 logical, len, ix, ix + 1);
997 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
998 }
999
1000 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
1001 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
1002 return -EFSCORRUPTED;
1003 }
1004
1005 ix->ei_block = cpu_to_le32(logical);
1006 ext4_idx_store_pblock(ix, ptr);
1007 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
1008
1009 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
1010 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
1011 return -EFSCORRUPTED;
1012 }
1013
1014 err = ext4_ext_dirty(handle, inode, curp);
1015 ext4_std_error(inode->i_sb, err);
1016
1017 return err;
1018}
1019
1020/*
1021 * ext4_ext_split:
1022 * inserts new subtree into the path, using free index entry
1023 * at depth @at:
1024 * - allocates all needed blocks (new leaf and all intermediate index blocks)
1025 * - makes decision where to split
1026 * - moves remaining extents and index entries (right to the split point)
1027 * into the newly allocated blocks
1028 * - initializes subtree
1029 */
1030static int ext4_ext_split(handle_t *handle, struct inode *inode,
1031 unsigned int flags,
1032 struct ext4_ext_path *path,
1033 struct ext4_extent *newext, int at)
1034{
1035 struct buffer_head *bh = NULL;
1036 int depth = ext_depth(inode);
1037 struct ext4_extent_header *neh;
1038 struct ext4_extent_idx *fidx;
1039 int i = at, k, m, a;
1040 ext4_fsblk_t newblock, oldblock;
1041 __le32 border;
1042 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1043 int err = 0;
1044
1045 /* make decision: where to split? */
1046 /* FIXME: now decision is simplest: at current extent */
1047
1048 /* if current leaf will be split, then we should use
1049 * border from split point */
1050 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1051 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1052 return -EFSCORRUPTED;
1053 }
1054 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1055 border = path[depth].p_ext[1].ee_block;
1056 ext_debug("leaf will be split."
1057 " next leaf starts at %d\n",
1058 le32_to_cpu(border));
1059 } else {
1060 border = newext->ee_block;
1061 ext_debug("leaf will be added."
1062 " next leaf starts at %d\n",
1063 le32_to_cpu(border));
1064 }
1065
1066 /*
1067 * If error occurs, then we break processing
1068 * and mark filesystem read-only. index won't
1069 * be inserted and tree will be in consistent
1070 * state. Next mount will repair buffers too.
1071 */
1072
1073 /*
1074 * Get array to track all allocated blocks.
1075 * We need this to handle errors and free blocks
1076 * upon them.
1077 */
1078 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
1079 if (!ablocks)
1080 return -ENOMEM;
1081
1082 /* allocate all needed blocks */
1083 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
1084 for (a = 0; a < depth - at; a++) {
1085 newblock = ext4_ext_new_meta_block(handle, inode, path,
1086 newext, &err, flags);
1087 if (newblock == 0)
1088 goto cleanup;
1089 ablocks[a] = newblock;
1090 }
1091
1092 /* initialize new leaf */
1093 newblock = ablocks[--a];
1094 if (unlikely(newblock == 0)) {
1095 EXT4_ERROR_INODE(inode, "newblock == 0!");
1096 err = -EFSCORRUPTED;
1097 goto cleanup;
1098 }
1099 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1100 if (unlikely(!bh)) {
1101 err = -ENOMEM;
1102 goto cleanup;
1103 }
1104 lock_buffer(bh);
1105
1106 err = ext4_journal_get_create_access(handle, bh);
1107 if (err)
1108 goto cleanup;
1109
1110 neh = ext_block_hdr(bh);
1111 neh->eh_entries = 0;
1112 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1113 neh->eh_magic = EXT4_EXT_MAGIC;
1114 neh->eh_depth = 0;
1115
1116 /* move remainder of path[depth] to the new leaf */
1117 if (unlikely(path[depth].p_hdr->eh_entries !=
1118 path[depth].p_hdr->eh_max)) {
1119 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1120 path[depth].p_hdr->eh_entries,
1121 path[depth].p_hdr->eh_max);
1122 err = -EFSCORRUPTED;
1123 goto cleanup;
1124 }
1125 /* start copy from next extent */
1126 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1127 ext4_ext_show_move(inode, path, newblock, depth);
1128 if (m) {
1129 struct ext4_extent *ex;
1130 ex = EXT_FIRST_EXTENT(neh);
1131 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1132 le16_add_cpu(&neh->eh_entries, m);
1133 }
1134
1135 ext4_extent_block_csum_set(inode, neh);
1136 set_buffer_uptodate(bh);
1137 unlock_buffer(bh);
1138
1139 err = ext4_handle_dirty_metadata(handle, inode, bh);
1140 if (err)
1141 goto cleanup;
1142 brelse(bh);
1143 bh = NULL;
1144
1145 /* correct old leaf */
1146 if (m) {
1147 err = ext4_ext_get_access(handle, inode, path + depth);
1148 if (err)
1149 goto cleanup;
1150 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1151 err = ext4_ext_dirty(handle, inode, path + depth);
1152 if (err)
1153 goto cleanup;
1154
1155 }
1156
1157 /* create intermediate indexes */
1158 k = depth - at - 1;
1159 if (unlikely(k < 0)) {
1160 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1161 err = -EFSCORRUPTED;
1162 goto cleanup;
1163 }
1164 if (k)
1165 ext_debug("create %d intermediate indices\n", k);
1166 /* insert new index into current index block */
1167 /* current depth stored in i var */
1168 i = depth - 1;
1169 while (k--) {
1170 oldblock = newblock;
1171 newblock = ablocks[--a];
1172 bh = sb_getblk(inode->i_sb, newblock);
1173 if (unlikely(!bh)) {
1174 err = -ENOMEM;
1175 goto cleanup;
1176 }
1177 lock_buffer(bh);
1178
1179 err = ext4_journal_get_create_access(handle, bh);
1180 if (err)
1181 goto cleanup;
1182
1183 neh = ext_block_hdr(bh);
1184 neh->eh_entries = cpu_to_le16(1);
1185 neh->eh_magic = EXT4_EXT_MAGIC;
1186 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1187 neh->eh_depth = cpu_to_le16(depth - i);
1188 fidx = EXT_FIRST_INDEX(neh);
1189 fidx->ei_block = border;
1190 ext4_idx_store_pblock(fidx, oldblock);
1191
1192 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1193 i, newblock, le32_to_cpu(border), oldblock);
1194
1195 /* move remainder of path[i] to the new index block */
1196 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1197 EXT_LAST_INDEX(path[i].p_hdr))) {
1198 EXT4_ERROR_INODE(inode,
1199 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1200 le32_to_cpu(path[i].p_ext->ee_block));
1201 err = -EFSCORRUPTED;
1202 goto cleanup;
1203 }
1204 /* start copy indexes */
1205 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1206 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1207 EXT_MAX_INDEX(path[i].p_hdr));
1208 ext4_ext_show_move(inode, path, newblock, i);
1209 if (m) {
1210 memmove(++fidx, path[i].p_idx,
1211 sizeof(struct ext4_extent_idx) * m);
1212 le16_add_cpu(&neh->eh_entries, m);
1213 }
1214 ext4_extent_block_csum_set(inode, neh);
1215 set_buffer_uptodate(bh);
1216 unlock_buffer(bh);
1217
1218 err = ext4_handle_dirty_metadata(handle, inode, bh);
1219 if (err)
1220 goto cleanup;
1221 brelse(bh);
1222 bh = NULL;
1223
1224 /* correct old index */
1225 if (m) {
1226 err = ext4_ext_get_access(handle, inode, path + i);
1227 if (err)
1228 goto cleanup;
1229 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1230 err = ext4_ext_dirty(handle, inode, path + i);
1231 if (err)
1232 goto cleanup;
1233 }
1234
1235 i--;
1236 }
1237
1238 /* insert new index */
1239 err = ext4_ext_insert_index(handle, inode, path + at,
1240 le32_to_cpu(border), newblock);
1241
1242cleanup:
1243 if (bh) {
1244 if (buffer_locked(bh))
1245 unlock_buffer(bh);
1246 brelse(bh);
1247 }
1248
1249 if (err) {
1250 /* free all allocated blocks in error case */
1251 for (i = 0; i < depth; i++) {
1252 if (!ablocks[i])
1253 continue;
1254 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1255 EXT4_FREE_BLOCKS_METADATA);
1256 }
1257 }
1258 kfree(ablocks);
1259
1260 return err;
1261}
1262
1263/*
1264 * ext4_ext_grow_indepth:
1265 * implements tree growing procedure:
1266 * - allocates new block
1267 * - moves top-level data (index block or leaf) into the new block
1268 * - initializes new top-level, creating index that points to the
1269 * just created block
1270 */
1271static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1272 unsigned int flags)
1273{
1274 struct ext4_extent_header *neh;
1275 struct buffer_head *bh;
1276 ext4_fsblk_t newblock, goal = 0;
1277 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
1278 int err = 0;
1279
1280 /* Try to prepend new index to old one */
1281 if (ext_depth(inode))
1282 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
1283 if (goal > le32_to_cpu(es->s_first_data_block)) {
1284 flags |= EXT4_MB_HINT_TRY_GOAL;
1285 goal--;
1286 } else
1287 goal = ext4_inode_to_goal_block(inode);
1288 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
1289 NULL, &err);
1290 if (newblock == 0)
1291 return err;
1292
1293 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1294 if (unlikely(!bh))
1295 return -ENOMEM;
1296 lock_buffer(bh);
1297
1298 err = ext4_journal_get_create_access(handle, bh);
1299 if (err) {
1300 unlock_buffer(bh);
1301 goto out;
1302 }
1303
1304 /* move top-level index/leaf into new block */
1305 memmove(bh->b_data, EXT4_I(inode)->i_data,
1306 sizeof(EXT4_I(inode)->i_data));
1307
1308 /* set size of new block */
1309 neh = ext_block_hdr(bh);
1310 /* old root could have indexes or leaves
1311 * so calculate e_max right way */
1312 if (ext_depth(inode))
1313 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1314 else
1315 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1316 neh->eh_magic = EXT4_EXT_MAGIC;
1317 ext4_extent_block_csum_set(inode, neh);
1318 set_buffer_uptodate(bh);
1319 unlock_buffer(bh);
1320
1321 err = ext4_handle_dirty_metadata(handle, inode, bh);
1322 if (err)
1323 goto out;
1324
1325 /* Update top-level index: num,max,pointer */
1326 neh = ext_inode_hdr(inode);
1327 neh->eh_entries = cpu_to_le16(1);
1328 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1329 if (neh->eh_depth == 0) {
1330 /* Root extent block becomes index block */
1331 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1332 EXT_FIRST_INDEX(neh)->ei_block =
1333 EXT_FIRST_EXTENT(neh)->ee_block;
1334 }
1335 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1336 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1337 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1338 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1339
1340 le16_add_cpu(&neh->eh_depth, 1);
1341 ext4_mark_inode_dirty(handle, inode);
1342out:
1343 brelse(bh);
1344
1345 return err;
1346}
1347
1348/*
1349 * ext4_ext_create_new_leaf:
1350 * finds empty index and adds new leaf.
1351 * if no free index is found, then it requests in-depth growing.
1352 */
1353static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1354 unsigned int mb_flags,
1355 unsigned int gb_flags,
1356 struct ext4_ext_path **ppath,
1357 struct ext4_extent *newext)
1358{
1359 struct ext4_ext_path *path = *ppath;
1360 struct ext4_ext_path *curp;
1361 int depth, i, err = 0;
1362
1363repeat:
1364 i = depth = ext_depth(inode);
1365
1366 /* walk up to the tree and look for free index entry */
1367 curp = path + depth;
1368 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1369 i--;
1370 curp--;
1371 }
1372
1373 /* we use already allocated block for index block,
1374 * so subsequent data blocks should be contiguous */
1375 if (EXT_HAS_FREE_INDEX(curp)) {
1376 /* if we found index with free entry, then use that
1377 * entry: create all needed subtree and add new leaf */
1378 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
1379 if (err)
1380 goto out;
1381
1382 /* refill path */
1383 path = ext4_find_extent(inode,
1384 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1385 ppath, gb_flags);
1386 if (IS_ERR(path))
1387 err = PTR_ERR(path);
1388 } else {
1389 /* tree is full, time to grow in depth */
1390 err = ext4_ext_grow_indepth(handle, inode, mb_flags);
1391 if (err)
1392 goto out;
1393
1394 /* refill path */
1395 path = ext4_find_extent(inode,
1396 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1397 ppath, gb_flags);
1398 if (IS_ERR(path)) {
1399 err = PTR_ERR(path);
1400 goto out;
1401 }
1402
1403 /*
1404 * only first (depth 0 -> 1) produces free space;
1405 * in all other cases we have to split the grown tree
1406 */
1407 depth = ext_depth(inode);
1408 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1409 /* now we need to split */
1410 goto repeat;
1411 }
1412 }
1413
1414out:
1415 return err;
1416}
1417
1418/*
1419 * search the closest allocated block to the left for *logical
1420 * and returns it at @logical + it's physical address at @phys
1421 * if *logical is the smallest allocated block, the function
1422 * returns 0 at @phys
1423 * return value contains 0 (success) or error code
1424 */
1425static int ext4_ext_search_left(struct inode *inode,
1426 struct ext4_ext_path *path,
1427 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1428{
1429 struct ext4_extent_idx *ix;
1430 struct ext4_extent *ex;
1431 int depth, ee_len;
1432
1433 if (unlikely(path == NULL)) {
1434 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1435 return -EFSCORRUPTED;
1436 }
1437 depth = path->p_depth;
1438 *phys = 0;
1439
1440 if (depth == 0 && path->p_ext == NULL)
1441 return 0;
1442
1443 /* usually extent in the path covers blocks smaller
1444 * then *logical, but it can be that extent is the
1445 * first one in the file */
1446
1447 ex = path[depth].p_ext;
1448 ee_len = ext4_ext_get_actual_len(ex);
1449 if (*logical < le32_to_cpu(ex->ee_block)) {
1450 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1451 EXT4_ERROR_INODE(inode,
1452 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1453 *logical, le32_to_cpu(ex->ee_block));
1454 return -EFSCORRUPTED;
1455 }
1456 while (--depth >= 0) {
1457 ix = path[depth].p_idx;
1458 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1459 EXT4_ERROR_INODE(inode,
1460 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1461 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1462 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1463 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1464 depth);
1465 return -EFSCORRUPTED;
1466 }
1467 }
1468 return 0;
1469 }
1470
1471 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1472 EXT4_ERROR_INODE(inode,
1473 "logical %d < ee_block %d + ee_len %d!",
1474 *logical, le32_to_cpu(ex->ee_block), ee_len);
1475 return -EFSCORRUPTED;
1476 }
1477
1478 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1479 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1480 return 0;
1481}
1482
1483/*
1484 * search the closest allocated block to the right for *logical
1485 * and returns it at @logical + it's physical address at @phys
1486 * if *logical is the largest allocated block, the function
1487 * returns 0 at @phys
1488 * return value contains 0 (success) or error code
1489 */
1490static int ext4_ext_search_right(struct inode *inode,
1491 struct ext4_ext_path *path,
1492 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1493 struct ext4_extent **ret_ex)
1494{
1495 struct buffer_head *bh = NULL;
1496 struct ext4_extent_header *eh;
1497 struct ext4_extent_idx *ix;
1498 struct ext4_extent *ex;
1499 ext4_fsblk_t block;
1500 int depth; /* Note, NOT eh_depth; depth from top of tree */
1501 int ee_len;
1502
1503 if (unlikely(path == NULL)) {
1504 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1505 return -EFSCORRUPTED;
1506 }
1507 depth = path->p_depth;
1508 *phys = 0;
1509
1510 if (depth == 0 && path->p_ext == NULL)
1511 return 0;
1512
1513 /* usually extent in the path covers blocks smaller
1514 * then *logical, but it can be that extent is the
1515 * first one in the file */
1516
1517 ex = path[depth].p_ext;
1518 ee_len = ext4_ext_get_actual_len(ex);
1519 if (*logical < le32_to_cpu(ex->ee_block)) {
1520 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1521 EXT4_ERROR_INODE(inode,
1522 "first_extent(path[%d].p_hdr) != ex",
1523 depth);
1524 return -EFSCORRUPTED;
1525 }
1526 while (--depth >= 0) {
1527 ix = path[depth].p_idx;
1528 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1529 EXT4_ERROR_INODE(inode,
1530 "ix != EXT_FIRST_INDEX *logical %d!",
1531 *logical);
1532 return -EFSCORRUPTED;
1533 }
1534 }
1535 goto found_extent;
1536 }
1537
1538 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1539 EXT4_ERROR_INODE(inode,
1540 "logical %d < ee_block %d + ee_len %d!",
1541 *logical, le32_to_cpu(ex->ee_block), ee_len);
1542 return -EFSCORRUPTED;
1543 }
1544
1545 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1546 /* next allocated block in this leaf */
1547 ex++;
1548 goto found_extent;
1549 }
1550
1551 /* go up and search for index to the right */
1552 while (--depth >= 0) {
1553 ix = path[depth].p_idx;
1554 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1555 goto got_index;
1556 }
1557
1558 /* we've gone up to the root and found no index to the right */
1559 return 0;
1560
1561got_index:
1562 /* we've found index to the right, let's
1563 * follow it and find the closest allocated
1564 * block to the right */
1565 ix++;
1566 block = ext4_idx_pblock(ix);
1567 while (++depth < path->p_depth) {
1568 /* subtract from p_depth to get proper eh_depth */
1569 bh = read_extent_tree_block(inode, block,
1570 path->p_depth - depth, 0);
1571 if (IS_ERR(bh))
1572 return PTR_ERR(bh);
1573 eh = ext_block_hdr(bh);
1574 ix = EXT_FIRST_INDEX(eh);
1575 block = ext4_idx_pblock(ix);
1576 put_bh(bh);
1577 }
1578
1579 bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0);
1580 if (IS_ERR(bh))
1581 return PTR_ERR(bh);
1582 eh = ext_block_hdr(bh);
1583 ex = EXT_FIRST_EXTENT(eh);
1584found_extent:
1585 *logical = le32_to_cpu(ex->ee_block);
1586 *phys = ext4_ext_pblock(ex);
1587 *ret_ex = ex;
1588 if (bh)
1589 put_bh(bh);
1590 return 0;
1591}
1592
1593/*
1594 * ext4_ext_next_allocated_block:
1595 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1596 * NOTE: it considers block number from index entry as
1597 * allocated block. Thus, index entries have to be consistent
1598 * with leaves.
1599 */
1600ext4_lblk_t
1601ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1602{
1603 int depth;
1604
1605 BUG_ON(path == NULL);
1606 depth = path->p_depth;
1607
1608 if (depth == 0 && path->p_ext == NULL)
1609 return EXT_MAX_BLOCKS;
1610
1611 while (depth >= 0) {
1612 if (depth == path->p_depth) {
1613 /* leaf */
1614 if (path[depth].p_ext &&
1615 path[depth].p_ext !=
1616 EXT_LAST_EXTENT(path[depth].p_hdr))
1617 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1618 } else {
1619 /* index */
1620 if (path[depth].p_idx !=
1621 EXT_LAST_INDEX(path[depth].p_hdr))
1622 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1623 }
1624 depth--;
1625 }
1626
1627 return EXT_MAX_BLOCKS;
1628}
1629
1630/*
1631 * ext4_ext_next_leaf_block:
1632 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1633 */
1634static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1635{
1636 int depth;
1637
1638 BUG_ON(path == NULL);
1639 depth = path->p_depth;
1640
1641 /* zero-tree has no leaf blocks at all */
1642 if (depth == 0)
1643 return EXT_MAX_BLOCKS;
1644
1645 /* go to index block */
1646 depth--;
1647
1648 while (depth >= 0) {
1649 if (path[depth].p_idx !=
1650 EXT_LAST_INDEX(path[depth].p_hdr))
1651 return (ext4_lblk_t)
1652 le32_to_cpu(path[depth].p_idx[1].ei_block);
1653 depth--;
1654 }
1655
1656 return EXT_MAX_BLOCKS;
1657}
1658
1659/*
1660 * ext4_ext_correct_indexes:
1661 * if leaf gets modified and modified extent is first in the leaf,
1662 * then we have to correct all indexes above.
1663 * TODO: do we need to correct tree in all cases?
1664 */
1665static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1666 struct ext4_ext_path *path)
1667{
1668 struct ext4_extent_header *eh;
1669 int depth = ext_depth(inode);
1670 struct ext4_extent *ex;
1671 __le32 border;
1672 int k, err = 0;
1673
1674 eh = path[depth].p_hdr;
1675 ex = path[depth].p_ext;
1676
1677 if (unlikely(ex == NULL || eh == NULL)) {
1678 EXT4_ERROR_INODE(inode,
1679 "ex %p == NULL or eh %p == NULL", ex, eh);
1680 return -EFSCORRUPTED;
1681 }
1682
1683 if (depth == 0) {
1684 /* there is no tree at all */
1685 return 0;
1686 }
1687
1688 if (ex != EXT_FIRST_EXTENT(eh)) {
1689 /* we correct tree if first leaf got modified only */
1690 return 0;
1691 }
1692
1693 /*
1694 * TODO: we need correction if border is smaller than current one
1695 */
1696 k = depth - 1;
1697 border = path[depth].p_ext->ee_block;
1698 err = ext4_ext_get_access(handle, inode, path + k);
1699 if (err)
1700 return err;
1701 path[k].p_idx->ei_block = border;
1702 err = ext4_ext_dirty(handle, inode, path + k);
1703 if (err)
1704 return err;
1705
1706 while (k--) {
1707 /* change all left-side indexes */
1708 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1709 break;
1710 err = ext4_ext_get_access(handle, inode, path + k);
1711 if (err)
1712 break;
1713 path[k].p_idx->ei_block = border;
1714 err = ext4_ext_dirty(handle, inode, path + k);
1715 if (err)
1716 break;
1717 }
1718
1719 return err;
1720}
1721
1722int
1723ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1724 struct ext4_extent *ex2)
1725{
1726 unsigned short ext1_ee_len, ext2_ee_len;
1727
1728 if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
1729 return 0;
1730
1731 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1732 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1733
1734 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1735 le32_to_cpu(ex2->ee_block))
1736 return 0;
1737
1738 /*
1739 * To allow future support for preallocated extents to be added
1740 * as an RO_COMPAT feature, refuse to merge to extents if
1741 * this can result in the top bit of ee_len being set.
1742 */
1743 if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1744 return 0;
1745 /*
1746 * The check for IO to unwritten extent is somewhat racy as we
1747 * increment i_unwritten / set EXT4_STATE_DIO_UNWRITTEN only after
1748 * dropping i_data_sem. But reserved blocks should save us in that
1749 * case.
1750 */
1751 if (ext4_ext_is_unwritten(ex1) &&
1752 (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) ||
1753 atomic_read(&EXT4_I(inode)->i_unwritten) ||
1754 (ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)))
1755 return 0;
1756#ifdef AGGRESSIVE_TEST
1757 if (ext1_ee_len >= 4)
1758 return 0;
1759#endif
1760
1761 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1762 return 1;
1763 return 0;
1764}
1765
1766/*
1767 * This function tries to merge the "ex" extent to the next extent in the tree.
1768 * It always tries to merge towards right. If you want to merge towards
1769 * left, pass "ex - 1" as argument instead of "ex".
1770 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1771 * 1 if they got merged.
1772 */
1773static int ext4_ext_try_to_merge_right(struct inode *inode,
1774 struct ext4_ext_path *path,
1775 struct ext4_extent *ex)
1776{
1777 struct ext4_extent_header *eh;
1778 unsigned int depth, len;
1779 int merge_done = 0, unwritten;
1780
1781 depth = ext_depth(inode);
1782 BUG_ON(path[depth].p_hdr == NULL);
1783 eh = path[depth].p_hdr;
1784
1785 while (ex < EXT_LAST_EXTENT(eh)) {
1786 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1787 break;
1788 /* merge with next extent! */
1789 unwritten = ext4_ext_is_unwritten(ex);
1790 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1791 + ext4_ext_get_actual_len(ex + 1));
1792 if (unwritten)
1793 ext4_ext_mark_unwritten(ex);
1794
1795 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1796 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1797 * sizeof(struct ext4_extent);
1798 memmove(ex + 1, ex + 2, len);
1799 }
1800 le16_add_cpu(&eh->eh_entries, -1);
1801 merge_done = 1;
1802 WARN_ON(eh->eh_entries == 0);
1803 if (!eh->eh_entries)
1804 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1805 }
1806
1807 return merge_done;
1808}
1809
1810/*
1811 * This function does a very simple check to see if we can collapse
1812 * an extent tree with a single extent tree leaf block into the inode.
1813 */
1814static void ext4_ext_try_to_merge_up(handle_t *handle,
1815 struct inode *inode,
1816 struct ext4_ext_path *path)
1817{
1818 size_t s;
1819 unsigned max_root = ext4_ext_space_root(inode, 0);
1820 ext4_fsblk_t blk;
1821
1822 if ((path[0].p_depth != 1) ||
1823 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1824 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1825 return;
1826
1827 /*
1828 * We need to modify the block allocation bitmap and the block
1829 * group descriptor to release the extent tree block. If we
1830 * can't get the journal credits, give up.
1831 */
1832 if (ext4_journal_extend(handle, 2))
1833 return;
1834
1835 /*
1836 * Copy the extent data up to the inode
1837 */
1838 blk = ext4_idx_pblock(path[0].p_idx);
1839 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1840 sizeof(struct ext4_extent_idx);
1841 s += sizeof(struct ext4_extent_header);
1842
1843 path[1].p_maxdepth = path[0].p_maxdepth;
1844 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1845 path[0].p_depth = 0;
1846 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1847 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1848 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1849
1850 brelse(path[1].p_bh);
1851 ext4_free_blocks(handle, inode, NULL, blk, 1,
1852 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1853}
1854
1855/*
1856 * This function tries to merge the @ex extent to neighbours in the tree.
1857 * return 1 if merge left else 0.
1858 */
1859static void ext4_ext_try_to_merge(handle_t *handle,
1860 struct inode *inode,
1861 struct ext4_ext_path *path,
1862 struct ext4_extent *ex) {
1863 struct ext4_extent_header *eh;
1864 unsigned int depth;
1865 int merge_done = 0;
1866
1867 depth = ext_depth(inode);
1868 BUG_ON(path[depth].p_hdr == NULL);
1869 eh = path[depth].p_hdr;
1870
1871 if (ex > EXT_FIRST_EXTENT(eh))
1872 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1873
1874 if (!merge_done)
1875 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1876
1877 ext4_ext_try_to_merge_up(handle, inode, path);
1878}
1879
1880/*
1881 * check if a portion of the "newext" extent overlaps with an
1882 * existing extent.
1883 *
1884 * If there is an overlap discovered, it updates the length of the newext
1885 * such that there will be no overlap, and then returns 1.
1886 * If there is no overlap found, it returns 0.
1887 */
1888static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1889 struct inode *inode,
1890 struct ext4_extent *newext,
1891 struct ext4_ext_path *path)
1892{
1893 ext4_lblk_t b1, b2;
1894 unsigned int depth, len1;
1895 unsigned int ret = 0;
1896
1897 b1 = le32_to_cpu(newext->ee_block);
1898 len1 = ext4_ext_get_actual_len(newext);
1899 depth = ext_depth(inode);
1900 if (!path[depth].p_ext)
1901 goto out;
1902 b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
1903
1904 /*
1905 * get the next allocated block if the extent in the path
1906 * is before the requested block(s)
1907 */
1908 if (b2 < b1) {
1909 b2 = ext4_ext_next_allocated_block(path);
1910 if (b2 == EXT_MAX_BLOCKS)
1911 goto out;
1912 b2 = EXT4_LBLK_CMASK(sbi, b2);
1913 }
1914
1915 /* check for wrap through zero on extent logical start block*/
1916 if (b1 + len1 < b1) {
1917 len1 = EXT_MAX_BLOCKS - b1;
1918 newext->ee_len = cpu_to_le16(len1);
1919 ret = 1;
1920 }
1921
1922 /* check for overlap */
1923 if (b1 + len1 > b2) {
1924 newext->ee_len = cpu_to_le16(b2 - b1);
1925 ret = 1;
1926 }
1927out:
1928 return ret;
1929}
1930
1931/*
1932 * ext4_ext_insert_extent:
1933 * tries to merge requsted extent into the existing extent or
1934 * inserts requested extent as new one into the tree,
1935 * creating new leaf in the no-space case.
1936 */
1937int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1938 struct ext4_ext_path **ppath,
1939 struct ext4_extent *newext, int gb_flags)
1940{
1941 struct ext4_ext_path *path = *ppath;
1942 struct ext4_extent_header *eh;
1943 struct ext4_extent *ex, *fex;
1944 struct ext4_extent *nearex; /* nearest extent */
1945 struct ext4_ext_path *npath = NULL;
1946 int depth, len, err;
1947 ext4_lblk_t next;
1948 int mb_flags = 0, unwritten;
1949
1950 if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1951 mb_flags |= EXT4_MB_DELALLOC_RESERVED;
1952 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1953 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1954 return -EFSCORRUPTED;
1955 }
1956 depth = ext_depth(inode);
1957 ex = path[depth].p_ext;
1958 eh = path[depth].p_hdr;
1959 if (unlikely(path[depth].p_hdr == NULL)) {
1960 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1961 return -EFSCORRUPTED;
1962 }
1963
1964 /* try to insert block into found extent and return */
1965 if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
1966
1967 /*
1968 * Try to see whether we should rather test the extent on
1969 * right from ex, or from the left of ex. This is because
1970 * ext4_find_extent() can return either extent on the
1971 * left, or on the right from the searched position. This
1972 * will make merging more effective.
1973 */
1974 if (ex < EXT_LAST_EXTENT(eh) &&
1975 (le32_to_cpu(ex->ee_block) +
1976 ext4_ext_get_actual_len(ex) <
1977 le32_to_cpu(newext->ee_block))) {
1978 ex += 1;
1979 goto prepend;
1980 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
1981 (le32_to_cpu(newext->ee_block) +
1982 ext4_ext_get_actual_len(newext) <
1983 le32_to_cpu(ex->ee_block)))
1984 ex -= 1;
1985
1986 /* Try to append newex to the ex */
1987 if (ext4_can_extents_be_merged(inode, ex, newext)) {
1988 ext_debug("append [%d]%d block to %u:[%d]%d"
1989 "(from %llu)\n",
1990 ext4_ext_is_unwritten(newext),
1991 ext4_ext_get_actual_len(newext),
1992 le32_to_cpu(ex->ee_block),
1993 ext4_ext_is_unwritten(ex),
1994 ext4_ext_get_actual_len(ex),
1995 ext4_ext_pblock(ex));
1996 err = ext4_ext_get_access(handle, inode,
1997 path + depth);
1998 if (err)
1999 return err;
2000 unwritten = ext4_ext_is_unwritten(ex);
2001 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2002 + ext4_ext_get_actual_len(newext));
2003 if (unwritten)
2004 ext4_ext_mark_unwritten(ex);
2005 eh = path[depth].p_hdr;
2006 nearex = ex;
2007 goto merge;
2008 }
2009
2010prepend:
2011 /* Try to prepend newex to the ex */
2012 if (ext4_can_extents_be_merged(inode, newext, ex)) {
2013 ext_debug("prepend %u[%d]%d block to %u:[%d]%d"
2014 "(from %llu)\n",
2015 le32_to_cpu(newext->ee_block),
2016 ext4_ext_is_unwritten(newext),
2017 ext4_ext_get_actual_len(newext),
2018 le32_to_cpu(ex->ee_block),
2019 ext4_ext_is_unwritten(ex),
2020 ext4_ext_get_actual_len(ex),
2021 ext4_ext_pblock(ex));
2022 err = ext4_ext_get_access(handle, inode,
2023 path + depth);
2024 if (err)
2025 return err;
2026
2027 unwritten = ext4_ext_is_unwritten(ex);
2028 ex->ee_block = newext->ee_block;
2029 ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
2030 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2031 + ext4_ext_get_actual_len(newext));
2032 if (unwritten)
2033 ext4_ext_mark_unwritten(ex);
2034 eh = path[depth].p_hdr;
2035 nearex = ex;
2036 goto merge;
2037 }
2038 }
2039
2040 depth = ext_depth(inode);
2041 eh = path[depth].p_hdr;
2042 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
2043 goto has_space;
2044
2045 /* probably next leaf has space for us? */
2046 fex = EXT_LAST_EXTENT(eh);
2047 next = EXT_MAX_BLOCKS;
2048 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
2049 next = ext4_ext_next_leaf_block(path);
2050 if (next != EXT_MAX_BLOCKS) {
2051 ext_debug("next leaf block - %u\n", next);
2052 BUG_ON(npath != NULL);
2053 npath = ext4_find_extent(inode, next, NULL, 0);
2054 if (IS_ERR(npath))
2055 return PTR_ERR(npath);
2056 BUG_ON(npath->p_depth != path->p_depth);
2057 eh = npath[depth].p_hdr;
2058 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2059 ext_debug("next leaf isn't full(%d)\n",
2060 le16_to_cpu(eh->eh_entries));
2061 path = npath;
2062 goto has_space;
2063 }
2064 ext_debug("next leaf has no free space(%d,%d)\n",
2065 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2066 }
2067
2068 /*
2069 * There is no free space in the found leaf.
2070 * We're gonna add a new leaf in the tree.
2071 */
2072 if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2073 mb_flags |= EXT4_MB_USE_RESERVED;
2074 err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2075 ppath, newext);
2076 if (err)
2077 goto cleanup;
2078 depth = ext_depth(inode);
2079 eh = path[depth].p_hdr;
2080
2081has_space:
2082 nearex = path[depth].p_ext;
2083
2084 err = ext4_ext_get_access(handle, inode, path + depth);
2085 if (err)
2086 goto cleanup;
2087
2088 if (!nearex) {
2089 /* there is no extent in this leaf, create first one */
2090 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
2091 le32_to_cpu(newext->ee_block),
2092 ext4_ext_pblock(newext),
2093 ext4_ext_is_unwritten(newext),
2094 ext4_ext_get_actual_len(newext));
2095 nearex = EXT_FIRST_EXTENT(eh);
2096 } else {
2097 if (le32_to_cpu(newext->ee_block)
2098 > le32_to_cpu(nearex->ee_block)) {
2099 /* Insert after */
2100 ext_debug("insert %u:%llu:[%d]%d before: "
2101 "nearest %p\n",
2102 le32_to_cpu(newext->ee_block),
2103 ext4_ext_pblock(newext),
2104 ext4_ext_is_unwritten(newext),
2105 ext4_ext_get_actual_len(newext),
2106 nearex);
2107 nearex++;
2108 } else {
2109 /* Insert before */
2110 BUG_ON(newext->ee_block == nearex->ee_block);
2111 ext_debug("insert %u:%llu:[%d]%d after: "
2112 "nearest %p\n",
2113 le32_to_cpu(newext->ee_block),
2114 ext4_ext_pblock(newext),
2115 ext4_ext_is_unwritten(newext),
2116 ext4_ext_get_actual_len(newext),
2117 nearex);
2118 }
2119 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2120 if (len > 0) {
2121 ext_debug("insert %u:%llu:[%d]%d: "
2122 "move %d extents from 0x%p to 0x%p\n",
2123 le32_to_cpu(newext->ee_block),
2124 ext4_ext_pblock(newext),
2125 ext4_ext_is_unwritten(newext),
2126 ext4_ext_get_actual_len(newext),
2127 len, nearex, nearex + 1);
2128 memmove(nearex + 1, nearex,
2129 len * sizeof(struct ext4_extent));
2130 }
2131 }
2132
2133 le16_add_cpu(&eh->eh_entries, 1);
2134 path[depth].p_ext = nearex;
2135 nearex->ee_block = newext->ee_block;
2136 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2137 nearex->ee_len = newext->ee_len;
2138
2139merge:
2140 /* try to merge extents */
2141 if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2142 ext4_ext_try_to_merge(handle, inode, path, nearex);
2143
2144
2145 /* time to correct all indexes above */
2146 err = ext4_ext_correct_indexes(handle, inode, path);
2147 if (err)
2148 goto cleanup;
2149
2150 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2151
2152cleanup:
2153 ext4_ext_drop_refs(npath);
2154 kfree(npath);
2155 return err;
2156}
2157
2158static int ext4_fill_fiemap_extents(struct inode *inode,
2159 ext4_lblk_t block, ext4_lblk_t num,
2160 struct fiemap_extent_info *fieinfo)
2161{
2162 struct ext4_ext_path *path = NULL;
2163 struct ext4_extent *ex;
2164 struct extent_status es;
2165 ext4_lblk_t next, next_del, start = 0, end = 0;
2166 ext4_lblk_t last = block + num;
2167 int exists, depth = 0, err = 0;
2168 unsigned int flags = 0;
2169 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2170
2171 while (block < last && block != EXT_MAX_BLOCKS) {
2172 num = last - block;
2173 /* find extent for this block */
2174 down_read(&EXT4_I(inode)->i_data_sem);
2175
2176 path = ext4_find_extent(inode, block, &path, 0);
2177 if (IS_ERR(path)) {
2178 up_read(&EXT4_I(inode)->i_data_sem);
2179 err = PTR_ERR(path);
2180 path = NULL;
2181 break;
2182 }
2183
2184 depth = ext_depth(inode);
2185 if (unlikely(path[depth].p_hdr == NULL)) {
2186 up_read(&EXT4_I(inode)->i_data_sem);
2187 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2188 err = -EFSCORRUPTED;
2189 break;
2190 }
2191 ex = path[depth].p_ext;
2192 next = ext4_ext_next_allocated_block(path);
2193
2194 flags = 0;
2195 exists = 0;
2196 if (!ex) {
2197 /* there is no extent yet, so try to allocate
2198 * all requested space */
2199 start = block;
2200 end = block + num;
2201 } else if (le32_to_cpu(ex->ee_block) > block) {
2202 /* need to allocate space before found extent */
2203 start = block;
2204 end = le32_to_cpu(ex->ee_block);
2205 if (block + num < end)
2206 end = block + num;
2207 } else if (block >= le32_to_cpu(ex->ee_block)
2208 + ext4_ext_get_actual_len(ex)) {
2209 /* need to allocate space after found extent */
2210 start = block;
2211 end = block + num;
2212 if (end >= next)
2213 end = next;
2214 } else if (block >= le32_to_cpu(ex->ee_block)) {
2215 /*
2216 * some part of requested space is covered
2217 * by found extent
2218 */
2219 start = block;
2220 end = le32_to_cpu(ex->ee_block)
2221 + ext4_ext_get_actual_len(ex);
2222 if (block + num < end)
2223 end = block + num;
2224 exists = 1;
2225 } else {
2226 BUG();
2227 }
2228 BUG_ON(end <= start);
2229
2230 if (!exists) {
2231 es.es_lblk = start;
2232 es.es_len = end - start;
2233 es.es_pblk = 0;
2234 } else {
2235 es.es_lblk = le32_to_cpu(ex->ee_block);
2236 es.es_len = ext4_ext_get_actual_len(ex);
2237 es.es_pblk = ext4_ext_pblock(ex);
2238 if (ext4_ext_is_unwritten(ex))
2239 flags |= FIEMAP_EXTENT_UNWRITTEN;
2240 }
2241
2242 /*
2243 * Find delayed extent and update es accordingly. We call
2244 * it even in !exists case to find out whether es is the
2245 * last existing extent or not.
2246 */
2247 next_del = ext4_find_delayed_extent(inode, &es);
2248 if (!exists && next_del) {
2249 exists = 1;
2250 flags |= (FIEMAP_EXTENT_DELALLOC |
2251 FIEMAP_EXTENT_UNKNOWN);
2252 }
2253 up_read(&EXT4_I(inode)->i_data_sem);
2254
2255 if (unlikely(es.es_len == 0)) {
2256 EXT4_ERROR_INODE(inode, "es.es_len == 0");
2257 err = -EFSCORRUPTED;
2258 break;
2259 }
2260
2261 /*
2262 * This is possible iff next == next_del == EXT_MAX_BLOCKS.
2263 * we need to check next == EXT_MAX_BLOCKS because it is
2264 * possible that an extent is with unwritten and delayed
2265 * status due to when an extent is delayed allocated and
2266 * is allocated by fallocate status tree will track both of
2267 * them in a extent.
2268 *
2269 * So we could return a unwritten and delayed extent, and
2270 * its block is equal to 'next'.
2271 */
2272 if (next == next_del && next == EXT_MAX_BLOCKS) {
2273 flags |= FIEMAP_EXTENT_LAST;
2274 if (unlikely(next_del != EXT_MAX_BLOCKS ||
2275 next != EXT_MAX_BLOCKS)) {
2276 EXT4_ERROR_INODE(inode,
2277 "next extent == %u, next "
2278 "delalloc extent = %u",
2279 next, next_del);
2280 err = -EFSCORRUPTED;
2281 break;
2282 }
2283 }
2284
2285 if (exists) {
2286 err = fiemap_fill_next_extent(fieinfo,
2287 (__u64)es.es_lblk << blksize_bits,
2288 (__u64)es.es_pblk << blksize_bits,
2289 (__u64)es.es_len << blksize_bits,
2290 flags);
2291 if (err < 0)
2292 break;
2293 if (err == 1) {
2294 err = 0;
2295 break;
2296 }
2297 }
2298
2299 block = es.es_lblk + es.es_len;
2300 }
2301
2302 ext4_ext_drop_refs(path);
2303 kfree(path);
2304 return err;
2305}
2306
2307/*
2308 * ext4_ext_determine_hole - determine hole around given block
2309 * @inode: inode we lookup in
2310 * @path: path in extent tree to @lblk
2311 * @lblk: pointer to logical block around which we want to determine hole
2312 *
2313 * Determine hole length (and start if easily possible) around given logical
2314 * block. We don't try too hard to find the beginning of the hole but @path
2315 * actually points to extent before @lblk, we provide it.
2316 *
2317 * The function returns the length of a hole starting at @lblk. We update @lblk
2318 * to the beginning of the hole if we managed to find it.
2319 */
2320static ext4_lblk_t ext4_ext_determine_hole(struct inode *inode,
2321 struct ext4_ext_path *path,
2322 ext4_lblk_t *lblk)
2323{
2324 int depth = ext_depth(inode);
2325 struct ext4_extent *ex;
2326 ext4_lblk_t len;
2327
2328 ex = path[depth].p_ext;
2329 if (ex == NULL) {
2330 /* there is no extent yet, so gap is [0;-] */
2331 *lblk = 0;
2332 len = EXT_MAX_BLOCKS;
2333 } else if (*lblk < le32_to_cpu(ex->ee_block)) {
2334 len = le32_to_cpu(ex->ee_block) - *lblk;
2335 } else if (*lblk >= le32_to_cpu(ex->ee_block)
2336 + ext4_ext_get_actual_len(ex)) {
2337 ext4_lblk_t next;
2338
2339 *lblk = le32_to_cpu(ex->ee_block) + ext4_ext_get_actual_len(ex);
2340 next = ext4_ext_next_allocated_block(path);
2341 BUG_ON(next == *lblk);
2342 len = next - *lblk;
2343 } else {
2344 BUG();
2345 }
2346 return len;
2347}
2348
2349/*
2350 * ext4_ext_put_gap_in_cache:
2351 * calculate boundaries of the gap that the requested block fits into
2352 * and cache this gap
2353 */
2354static void
2355ext4_ext_put_gap_in_cache(struct inode *inode, ext4_lblk_t hole_start,
2356 ext4_lblk_t hole_len)
2357{
2358 struct extent_status es;
2359
2360 ext4_es_find_delayed_extent_range(inode, hole_start,
2361 hole_start + hole_len - 1, &es);
2362 if (es.es_len) {
2363 /* There's delayed extent containing lblock? */
2364 if (es.es_lblk <= hole_start)
2365 return;
2366 hole_len = min(es.es_lblk - hole_start, hole_len);
2367 }
2368 ext_debug(" -> %u:%u\n", hole_start, hole_len);
2369 ext4_es_insert_extent(inode, hole_start, hole_len, ~0,
2370 EXTENT_STATUS_HOLE);
2371}
2372
2373/*
2374 * ext4_ext_rm_idx:
2375 * removes index from the index block.
2376 */
2377static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2378 struct ext4_ext_path *path, int depth)
2379{
2380 int err;
2381 ext4_fsblk_t leaf;
2382
2383 /* free index block */
2384 depth--;
2385 path = path + depth;
2386 leaf = ext4_idx_pblock(path->p_idx);
2387 if (unlikely(path->p_hdr->eh_entries == 0)) {
2388 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2389 return -EFSCORRUPTED;
2390 }
2391 err = ext4_ext_get_access(handle, inode, path);
2392 if (err)
2393 return err;
2394
2395 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2396 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2397 len *= sizeof(struct ext4_extent_idx);
2398 memmove(path->p_idx, path->p_idx + 1, len);
2399 }
2400
2401 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2402 err = ext4_ext_dirty(handle, inode, path);
2403 if (err)
2404 return err;
2405 ext_debug("index is empty, remove it, free block %llu\n", leaf);
2406 trace_ext4_ext_rm_idx(inode, leaf);
2407
2408 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2409 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2410
2411 while (--depth >= 0) {
2412 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2413 break;
2414 path--;
2415 err = ext4_ext_get_access(handle, inode, path);
2416 if (err)
2417 break;
2418 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2419 err = ext4_ext_dirty(handle, inode, path);
2420 if (err)
2421 break;
2422 }
2423 return err;
2424}
2425
2426/*
2427 * ext4_ext_calc_credits_for_single_extent:
2428 * This routine returns max. credits that needed to insert an extent
2429 * to the extent tree.
2430 * When pass the actual path, the caller should calculate credits
2431 * under i_data_sem.
2432 */
2433int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2434 struct ext4_ext_path *path)
2435{
2436 if (path) {
2437 int depth = ext_depth(inode);
2438 int ret = 0;
2439
2440 /* probably there is space in leaf? */
2441 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2442 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2443
2444 /*
2445 * There are some space in the leaf tree, no
2446 * need to account for leaf block credit
2447 *
2448 * bitmaps and block group descriptor blocks
2449 * and other metadata blocks still need to be
2450 * accounted.
2451 */
2452 /* 1 bitmap, 1 block group descriptor */
2453 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2454 return ret;
2455 }
2456 }
2457
2458 return ext4_chunk_trans_blocks(inode, nrblocks);
2459}
2460
2461/*
2462 * How many index/leaf blocks need to change/allocate to add @extents extents?
2463 *
2464 * If we add a single extent, then in the worse case, each tree level
2465 * index/leaf need to be changed in case of the tree split.
2466 *
2467 * If more extents are inserted, they could cause the whole tree split more
2468 * than once, but this is really rare.
2469 */
2470int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2471{
2472 int index;
2473 int depth;
2474
2475 /* If we are converting the inline data, only one is needed here. */
2476 if (ext4_has_inline_data(inode))
2477 return 1;
2478
2479 depth = ext_depth(inode);
2480
2481 if (extents <= 1)
2482 index = depth * 2;
2483 else
2484 index = depth * 3;
2485
2486 return index;
2487}
2488
2489static inline int get_default_free_blocks_flags(struct inode *inode)
2490{
2491 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2492 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2493 else if (ext4_should_journal_data(inode))
2494 return EXT4_FREE_BLOCKS_FORGET;
2495 return 0;
2496}
2497
2498static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2499 struct ext4_extent *ex,
2500 long long *partial_cluster,
2501 ext4_lblk_t from, ext4_lblk_t to)
2502{
2503 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2504 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2505 ext4_fsblk_t pblk;
2506 int flags = get_default_free_blocks_flags(inode);
2507
2508 /*
2509 * For bigalloc file systems, we never free a partial cluster
2510 * at the beginning of the extent. Instead, we make a note
2511 * that we tried freeing the cluster, and check to see if we
2512 * need to free it on a subsequent call to ext4_remove_blocks,
2513 * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
2514 */
2515 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2516
2517 trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2518 /*
2519 * If we have a partial cluster, and it's different from the
2520 * cluster of the last block, we need to explicitly free the
2521 * partial cluster here.
2522 */
2523 pblk = ext4_ext_pblock(ex) + ee_len - 1;
2524 if (*partial_cluster > 0 &&
2525 *partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2526 ext4_free_blocks(handle, inode, NULL,
2527 EXT4_C2B(sbi, *partial_cluster),
2528 sbi->s_cluster_ratio, flags);
2529 *partial_cluster = 0;
2530 }
2531
2532#ifdef EXTENTS_STATS
2533 {
2534 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2535 spin_lock(&sbi->s_ext_stats_lock);
2536 sbi->s_ext_blocks += ee_len;
2537 sbi->s_ext_extents++;
2538 if (ee_len < sbi->s_ext_min)
2539 sbi->s_ext_min = ee_len;
2540 if (ee_len > sbi->s_ext_max)
2541 sbi->s_ext_max = ee_len;
2542 if (ext_depth(inode) > sbi->s_depth_max)
2543 sbi->s_depth_max = ext_depth(inode);
2544 spin_unlock(&sbi->s_ext_stats_lock);
2545 }
2546#endif
2547 if (from >= le32_to_cpu(ex->ee_block)
2548 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2549 /* tail removal */
2550 ext4_lblk_t num;
2551 long long first_cluster;
2552
2553 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2554 pblk = ext4_ext_pblock(ex) + ee_len - num;
2555 /*
2556 * Usually we want to free partial cluster at the end of the
2557 * extent, except for the situation when the cluster is still
2558 * used by any other extent (partial_cluster is negative).
2559 */
2560 if (*partial_cluster < 0 &&
2561 *partial_cluster == -(long long) EXT4_B2C(sbi, pblk+num-1))
2562 flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2563
2564 ext_debug("free last %u blocks starting %llu partial %lld\n",
2565 num, pblk, *partial_cluster);
2566 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2567 /*
2568 * If the block range to be freed didn't start at the
2569 * beginning of a cluster, and we removed the entire
2570 * extent and the cluster is not used by any other extent,
2571 * save the partial cluster here, since we might need to
2572 * delete if we determine that the truncate or punch hole
2573 * operation has removed all of the blocks in the cluster.
2574 * If that cluster is used by another extent, preserve its
2575 * negative value so it isn't freed later on.
2576 *
2577 * If the whole extent wasn't freed, we've reached the
2578 * start of the truncated/punched region and have finished
2579 * removing blocks. If there's a partial cluster here it's
2580 * shared with the remainder of the extent and is no longer
2581 * a candidate for removal.
2582 */
2583 if (EXT4_PBLK_COFF(sbi, pblk) && ee_len == num) {
2584 first_cluster = (long long) EXT4_B2C(sbi, pblk);
2585 if (first_cluster != -*partial_cluster)
2586 *partial_cluster = first_cluster;
2587 } else {
2588 *partial_cluster = 0;
2589 }
2590 } else
2591 ext4_error(sbi->s_sb, "strange request: removal(2) "
2592 "%u-%u from %u:%u",
2593 from, to, le32_to_cpu(ex->ee_block), ee_len);
2594 return 0;
2595}
2596
2597
2598/*
2599 * ext4_ext_rm_leaf() Removes the extents associated with the
2600 * blocks appearing between "start" and "end". Both "start"
2601 * and "end" must appear in the same extent or EIO is returned.
2602 *
2603 * @handle: The journal handle
2604 * @inode: The files inode
2605 * @path: The path to the leaf
2606 * @partial_cluster: The cluster which we'll have to free if all extents
2607 * has been released from it. However, if this value is
2608 * negative, it's a cluster just to the right of the
2609 * punched region and it must not be freed.
2610 * @start: The first block to remove
2611 * @end: The last block to remove
2612 */
2613static int
2614ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2615 struct ext4_ext_path *path,
2616 long long *partial_cluster,
2617 ext4_lblk_t start, ext4_lblk_t end)
2618{
2619 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2620 int err = 0, correct_index = 0;
2621 int depth = ext_depth(inode), credits;
2622 struct ext4_extent_header *eh;
2623 ext4_lblk_t a, b;
2624 unsigned num;
2625 ext4_lblk_t ex_ee_block;
2626 unsigned short ex_ee_len;
2627 unsigned unwritten = 0;
2628 struct ext4_extent *ex;
2629 ext4_fsblk_t pblk;
2630
2631 /* the header must be checked already in ext4_ext_remove_space() */
2632 ext_debug("truncate since %u in leaf to %u\n", start, end);
2633 if (!path[depth].p_hdr)
2634 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2635 eh = path[depth].p_hdr;
2636 if (unlikely(path[depth].p_hdr == NULL)) {
2637 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2638 return -EFSCORRUPTED;
2639 }
2640 /* find where to start removing */
2641 ex = path[depth].p_ext;
2642 if (!ex)
2643 ex = EXT_LAST_EXTENT(eh);
2644
2645 ex_ee_block = le32_to_cpu(ex->ee_block);
2646 ex_ee_len = ext4_ext_get_actual_len(ex);
2647
2648 trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2649
2650 while (ex >= EXT_FIRST_EXTENT(eh) &&
2651 ex_ee_block + ex_ee_len > start) {
2652
2653 if (ext4_ext_is_unwritten(ex))
2654 unwritten = 1;
2655 else
2656 unwritten = 0;
2657
2658 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2659 unwritten, ex_ee_len);
2660 path[depth].p_ext = ex;
2661
2662 a = ex_ee_block > start ? ex_ee_block : start;
2663 b = ex_ee_block+ex_ee_len - 1 < end ?
2664 ex_ee_block+ex_ee_len - 1 : end;
2665
2666 ext_debug(" border %u:%u\n", a, b);
2667
2668 /* If this extent is beyond the end of the hole, skip it */
2669 if (end < ex_ee_block) {
2670 /*
2671 * We're going to skip this extent and move to another,
2672 * so note that its first cluster is in use to avoid
2673 * freeing it when removing blocks. Eventually, the
2674 * right edge of the truncated/punched region will
2675 * be just to the left.
2676 */
2677 if (sbi->s_cluster_ratio > 1) {
2678 pblk = ext4_ext_pblock(ex);
2679 *partial_cluster =
2680 -(long long) EXT4_B2C(sbi, pblk);
2681 }
2682 ex--;
2683 ex_ee_block = le32_to_cpu(ex->ee_block);
2684 ex_ee_len = ext4_ext_get_actual_len(ex);
2685 continue;
2686 } else if (b != ex_ee_block + ex_ee_len - 1) {
2687 EXT4_ERROR_INODE(inode,
2688 "can not handle truncate %u:%u "
2689 "on extent %u:%u",
2690 start, end, ex_ee_block,
2691 ex_ee_block + ex_ee_len - 1);
2692 err = -EFSCORRUPTED;
2693 goto out;
2694 } else if (a != ex_ee_block) {
2695 /* remove tail of the extent */
2696 num = a - ex_ee_block;
2697 } else {
2698 /* remove whole extent: excellent! */
2699 num = 0;
2700 }
2701 /*
2702 * 3 for leaf, sb, and inode plus 2 (bmap and group
2703 * descriptor) for each block group; assume two block
2704 * groups plus ex_ee_len/blocks_per_block_group for
2705 * the worst case
2706 */
2707 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2708 if (ex == EXT_FIRST_EXTENT(eh)) {
2709 correct_index = 1;
2710 credits += (ext_depth(inode)) + 1;
2711 }
2712 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2713
2714 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2715 if (err)
2716 goto out;
2717
2718 err = ext4_ext_get_access(handle, inode, path + depth);
2719 if (err)
2720 goto out;
2721
2722 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2723 a, b);
2724 if (err)
2725 goto out;
2726
2727 if (num == 0)
2728 /* this extent is removed; mark slot entirely unused */
2729 ext4_ext_store_pblock(ex, 0);
2730
2731 ex->ee_len = cpu_to_le16(num);
2732 /*
2733 * Do not mark unwritten if all the blocks in the
2734 * extent have been removed.
2735 */
2736 if (unwritten && num)
2737 ext4_ext_mark_unwritten(ex);
2738 /*
2739 * If the extent was completely released,
2740 * we need to remove it from the leaf
2741 */
2742 if (num == 0) {
2743 if (end != EXT_MAX_BLOCKS - 1) {
2744 /*
2745 * For hole punching, we need to scoot all the
2746 * extents up when an extent is removed so that
2747 * we dont have blank extents in the middle
2748 */
2749 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2750 sizeof(struct ext4_extent));
2751
2752 /* Now get rid of the one at the end */
2753 memset(EXT_LAST_EXTENT(eh), 0,
2754 sizeof(struct ext4_extent));
2755 }
2756 le16_add_cpu(&eh->eh_entries, -1);
2757 }
2758
2759 err = ext4_ext_dirty(handle, inode, path + depth);
2760 if (err)
2761 goto out;
2762
2763 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2764 ext4_ext_pblock(ex));
2765 ex--;
2766 ex_ee_block = le32_to_cpu(ex->ee_block);
2767 ex_ee_len = ext4_ext_get_actual_len(ex);
2768 }
2769
2770 if (correct_index && eh->eh_entries)
2771 err = ext4_ext_correct_indexes(handle, inode, path);
2772
2773 /*
2774 * If there's a partial cluster and at least one extent remains in
2775 * the leaf, free the partial cluster if it isn't shared with the
2776 * current extent. If it is shared with the current extent
2777 * we zero partial_cluster because we've reached the start of the
2778 * truncated/punched region and we're done removing blocks.
2779 */
2780 if (*partial_cluster > 0 && ex >= EXT_FIRST_EXTENT(eh)) {
2781 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
2782 if (*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2783 ext4_free_blocks(handle, inode, NULL,
2784 EXT4_C2B(sbi, *partial_cluster),
2785 sbi->s_cluster_ratio,
2786 get_default_free_blocks_flags(inode));
2787 }
2788 *partial_cluster = 0;
2789 }
2790
2791 /* if this leaf is free, then we should
2792 * remove it from index block above */
2793 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2794 err = ext4_ext_rm_idx(handle, inode, path, depth);
2795
2796out:
2797 return err;
2798}
2799
2800/*
2801 * ext4_ext_more_to_rm:
2802 * returns 1 if current index has to be freed (even partial)
2803 */
2804static int
2805ext4_ext_more_to_rm(struct ext4_ext_path *path)
2806{
2807 BUG_ON(path->p_idx == NULL);
2808
2809 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2810 return 0;
2811
2812 /*
2813 * if truncate on deeper level happened, it wasn't partial,
2814 * so we have to consider current index for truncation
2815 */
2816 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2817 return 0;
2818 return 1;
2819}
2820
2821int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2822 ext4_lblk_t end)
2823{
2824 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2825 int depth = ext_depth(inode);
2826 struct ext4_ext_path *path = NULL;
2827 long long partial_cluster = 0;
2828 handle_t *handle;
2829 int i = 0, err = 0;
2830
2831 ext_debug("truncate since %u to %u\n", start, end);
2832
2833 /* probably first extent we're gonna free will be last in block */
2834 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1);
2835 if (IS_ERR(handle))
2836 return PTR_ERR(handle);
2837
2838again:
2839 trace_ext4_ext_remove_space(inode, start, end, depth);
2840
2841 /*
2842 * Check if we are removing extents inside the extent tree. If that
2843 * is the case, we are going to punch a hole inside the extent tree
2844 * so we have to check whether we need to split the extent covering
2845 * the last block to remove so we can easily remove the part of it
2846 * in ext4_ext_rm_leaf().
2847 */
2848 if (end < EXT_MAX_BLOCKS - 1) {
2849 struct ext4_extent *ex;
2850 ext4_lblk_t ee_block, ex_end, lblk;
2851 ext4_fsblk_t pblk;
2852
2853 /* find extent for or closest extent to this block */
2854 path = ext4_find_extent(inode, end, NULL, EXT4_EX_NOCACHE);
2855 if (IS_ERR(path)) {
2856 ext4_journal_stop(handle);
2857 return PTR_ERR(path);
2858 }
2859 depth = ext_depth(inode);
2860 /* Leaf not may not exist only if inode has no blocks at all */
2861 ex = path[depth].p_ext;
2862 if (!ex) {
2863 if (depth) {
2864 EXT4_ERROR_INODE(inode,
2865 "path[%d].p_hdr == NULL",
2866 depth);
2867 err = -EFSCORRUPTED;
2868 }
2869 goto out;
2870 }
2871
2872 ee_block = le32_to_cpu(ex->ee_block);
2873 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
2874
2875 /*
2876 * See if the last block is inside the extent, if so split
2877 * the extent at 'end' block so we can easily remove the
2878 * tail of the first part of the split extent in
2879 * ext4_ext_rm_leaf().
2880 */
2881 if (end >= ee_block && end < ex_end) {
2882
2883 /*
2884 * If we're going to split the extent, note that
2885 * the cluster containing the block after 'end' is
2886 * in use to avoid freeing it when removing blocks.
2887 */
2888 if (sbi->s_cluster_ratio > 1) {
2889 pblk = ext4_ext_pblock(ex) + end - ee_block + 2;
2890 partial_cluster =
2891 -(long long) EXT4_B2C(sbi, pblk);
2892 }
2893
2894 /*
2895 * Split the extent in two so that 'end' is the last
2896 * block in the first new extent. Also we should not
2897 * fail removing space due to ENOSPC so try to use
2898 * reserved block if that happens.
2899 */
2900 err = ext4_force_split_extent_at(handle, inode, &path,
2901 end + 1, 1);
2902 if (err < 0)
2903 goto out;
2904
2905 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end) {
2906 /*
2907 * If there's an extent to the right its first cluster
2908 * contains the immediate right boundary of the
2909 * truncated/punched region. Set partial_cluster to
2910 * its negative value so it won't be freed if shared
2911 * with the current extent. The end < ee_block case
2912 * is handled in ext4_ext_rm_leaf().
2913 */
2914 lblk = ex_end + 1;
2915 err = ext4_ext_search_right(inode, path, &lblk, &pblk,
2916 &ex);
2917 if (err)
2918 goto out;
2919 if (pblk)
2920 partial_cluster =
2921 -(long long) EXT4_B2C(sbi, pblk);
2922 }
2923 }
2924 /*
2925 * We start scanning from right side, freeing all the blocks
2926 * after i_size and walking into the tree depth-wise.
2927 */
2928 depth = ext_depth(inode);
2929 if (path) {
2930 int k = i = depth;
2931 while (--k > 0)
2932 path[k].p_block =
2933 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2934 } else {
2935 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2936 GFP_NOFS);
2937 if (path == NULL) {
2938 ext4_journal_stop(handle);
2939 return -ENOMEM;
2940 }
2941 path[0].p_maxdepth = path[0].p_depth = depth;
2942 path[0].p_hdr = ext_inode_hdr(inode);
2943 i = 0;
2944
2945 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2946 err = -EFSCORRUPTED;
2947 goto out;
2948 }
2949 }
2950 err = 0;
2951
2952 while (i >= 0 && err == 0) {
2953 if (i == depth) {
2954 /* this is leaf block */
2955 err = ext4_ext_rm_leaf(handle, inode, path,
2956 &partial_cluster, start,
2957 end);
2958 /* root level has p_bh == NULL, brelse() eats this */
2959 brelse(path[i].p_bh);
2960 path[i].p_bh = NULL;
2961 i--;
2962 continue;
2963 }
2964
2965 /* this is index block */
2966 if (!path[i].p_hdr) {
2967 ext_debug("initialize header\n");
2968 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2969 }
2970
2971 if (!path[i].p_idx) {
2972 /* this level hasn't been touched yet */
2973 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2974 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2975 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2976 path[i].p_hdr,
2977 le16_to_cpu(path[i].p_hdr->eh_entries));
2978 } else {
2979 /* we were already here, see at next index */
2980 path[i].p_idx--;
2981 }
2982
2983 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2984 i, EXT_FIRST_INDEX(path[i].p_hdr),
2985 path[i].p_idx);
2986 if (ext4_ext_more_to_rm(path + i)) {
2987 struct buffer_head *bh;
2988 /* go to the next level */
2989 ext_debug("move to level %d (block %llu)\n",
2990 i + 1, ext4_idx_pblock(path[i].p_idx));
2991 memset(path + i + 1, 0, sizeof(*path));
2992 bh = read_extent_tree_block(inode,
2993 ext4_idx_pblock(path[i].p_idx), depth - i - 1,
2994 EXT4_EX_NOCACHE);
2995 if (IS_ERR(bh)) {
2996 /* should we reset i_size? */
2997 err = PTR_ERR(bh);
2998 break;
2999 }
3000 /* Yield here to deal with large extent trees.
3001 * Should be a no-op if we did IO above. */
3002 cond_resched();
3003 if (WARN_ON(i + 1 > depth)) {
3004 err = -EFSCORRUPTED;
3005 break;
3006 }
3007 path[i + 1].p_bh = bh;
3008
3009 /* save actual number of indexes since this
3010 * number is changed at the next iteration */
3011 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
3012 i++;
3013 } else {
3014 /* we finished processing this index, go up */
3015 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
3016 /* index is empty, remove it;
3017 * handle must be already prepared by the
3018 * truncatei_leaf() */
3019 err = ext4_ext_rm_idx(handle, inode, path, i);
3020 }
3021 /* root level has p_bh == NULL, brelse() eats this */
3022 brelse(path[i].p_bh);
3023 path[i].p_bh = NULL;
3024 i--;
3025 ext_debug("return to level %d\n", i);
3026 }
3027 }
3028
3029 trace_ext4_ext_remove_space_done(inode, start, end, depth,
3030 partial_cluster, path->p_hdr->eh_entries);
3031
3032 /*
3033 * If we still have something in the partial cluster and we have removed
3034 * even the first extent, then we should free the blocks in the partial
3035 * cluster as well. (This code will only run when there are no leaves
3036 * to the immediate left of the truncated/punched region.)
3037 */
3038 if (partial_cluster > 0 && err == 0) {
3039 /* don't zero partial_cluster since it's not used afterwards */
3040 ext4_free_blocks(handle, inode, NULL,
3041 EXT4_C2B(sbi, partial_cluster),
3042 sbi->s_cluster_ratio,
3043 get_default_free_blocks_flags(inode));
3044 }
3045
3046 /* TODO: flexible tree reduction should be here */
3047 if (path->p_hdr->eh_entries == 0) {
3048 /*
3049 * truncate to zero freed all the tree,
3050 * so we need to correct eh_depth
3051 */
3052 err = ext4_ext_get_access(handle, inode, path);
3053 if (err == 0) {
3054 ext_inode_hdr(inode)->eh_depth = 0;
3055 ext_inode_hdr(inode)->eh_max =
3056 cpu_to_le16(ext4_ext_space_root(inode, 0));
3057 err = ext4_ext_dirty(handle, inode, path);
3058 }
3059 }
3060out:
3061 ext4_ext_drop_refs(path);
3062 kfree(path);
3063 path = NULL;
3064 if (err == -EAGAIN)
3065 goto again;
3066 ext4_journal_stop(handle);
3067
3068 return err;
3069}
3070
3071/*
3072 * called at mount time
3073 */
3074void ext4_ext_init(struct super_block *sb)
3075{
3076 /*
3077 * possible initialization would be here
3078 */
3079
3080 if (ext4_has_feature_extents(sb)) {
3081#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
3082 printk(KERN_INFO "EXT4-fs: file extents enabled"
3083#ifdef AGGRESSIVE_TEST
3084 ", aggressive tests"
3085#endif
3086#ifdef CHECK_BINSEARCH
3087 ", check binsearch"
3088#endif
3089#ifdef EXTENTS_STATS
3090 ", stats"
3091#endif
3092 "\n");
3093#endif
3094#ifdef EXTENTS_STATS
3095 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3096 EXT4_SB(sb)->s_ext_min = 1 << 30;
3097 EXT4_SB(sb)->s_ext_max = 0;
3098#endif
3099 }
3100}
3101
3102/*
3103 * called at umount time
3104 */
3105void ext4_ext_release(struct super_block *sb)
3106{
3107 if (!ext4_has_feature_extents(sb))
3108 return;
3109
3110#ifdef EXTENTS_STATS
3111 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3112 struct ext4_sb_info *sbi = EXT4_SB(sb);
3113 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3114 sbi->s_ext_blocks, sbi->s_ext_extents,
3115 sbi->s_ext_blocks / sbi->s_ext_extents);
3116 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3117 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3118 }
3119#endif
3120}
3121
3122static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3123{
3124 ext4_lblk_t ee_block;
3125 ext4_fsblk_t ee_pblock;
3126 unsigned int ee_len;
3127
3128 ee_block = le32_to_cpu(ex->ee_block);
3129 ee_len = ext4_ext_get_actual_len(ex);
3130 ee_pblock = ext4_ext_pblock(ex);
3131
3132 if (ee_len == 0)
3133 return 0;
3134
3135 return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3136 EXTENT_STATUS_WRITTEN);
3137}
3138
3139/* FIXME!! we need to try to merge to left or right after zero-out */
3140static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3141{
3142 ext4_fsblk_t ee_pblock;
3143 unsigned int ee_len;
3144
3145 ee_len = ext4_ext_get_actual_len(ex);
3146 ee_pblock = ext4_ext_pblock(ex);
3147 return ext4_issue_zeroout(inode, le32_to_cpu(ex->ee_block), ee_pblock,
3148 ee_len);
3149}
3150
3151/*
3152 * ext4_split_extent_at() splits an extent at given block.
3153 *
3154 * @handle: the journal handle
3155 * @inode: the file inode
3156 * @path: the path to the extent
3157 * @split: the logical block where the extent is splitted.
3158 * @split_flags: indicates if the extent could be zeroout if split fails, and
3159 * the states(init or unwritten) of new extents.
3160 * @flags: flags used to insert new extent to extent tree.
3161 *
3162 *
3163 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3164 * of which are deterimined by split_flag.
3165 *
3166 * There are two cases:
3167 * a> the extent are splitted into two extent.
3168 * b> split is not needed, and just mark the extent.
3169 *
3170 * return 0 on success.
3171 */
3172static int ext4_split_extent_at(handle_t *handle,
3173 struct inode *inode,
3174 struct ext4_ext_path **ppath,
3175 ext4_lblk_t split,
3176 int split_flag,
3177 int flags)
3178{
3179 struct ext4_ext_path *path = *ppath;
3180 ext4_fsblk_t newblock;
3181 ext4_lblk_t ee_block;
3182 struct ext4_extent *ex, newex, orig_ex, zero_ex;
3183 struct ext4_extent *ex2 = NULL;
3184 unsigned int ee_len, depth;
3185 int err = 0;
3186
3187 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3188 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3189
3190 ext_debug("ext4_split_extents_at: inode %lu, logical"
3191 "block %llu\n", inode->i_ino, (unsigned long long)split);
3192
3193 ext4_ext_show_leaf(inode, path);
3194
3195 depth = ext_depth(inode);
3196 ex = path[depth].p_ext;
3197 ee_block = le32_to_cpu(ex->ee_block);
3198 ee_len = ext4_ext_get_actual_len(ex);
3199 newblock = split - ee_block + ext4_ext_pblock(ex);
3200
3201 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3202 BUG_ON(!ext4_ext_is_unwritten(ex) &&
3203 split_flag & (EXT4_EXT_MAY_ZEROOUT |
3204 EXT4_EXT_MARK_UNWRIT1 |
3205 EXT4_EXT_MARK_UNWRIT2));
3206
3207 err = ext4_ext_get_access(handle, inode, path + depth);
3208 if (err)
3209 goto out;
3210
3211 if (split == ee_block) {
3212 /*
3213 * case b: block @split is the block that the extent begins with
3214 * then we just change the state of the extent, and splitting
3215 * is not needed.
3216 */
3217 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3218 ext4_ext_mark_unwritten(ex);
3219 else
3220 ext4_ext_mark_initialized(ex);
3221
3222 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3223 ext4_ext_try_to_merge(handle, inode, path, ex);
3224
3225 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3226 goto out;
3227 }
3228
3229 /* case a */
3230 memcpy(&orig_ex, ex, sizeof(orig_ex));
3231 ex->ee_len = cpu_to_le16(split - ee_block);
3232 if (split_flag & EXT4_EXT_MARK_UNWRIT1)
3233 ext4_ext_mark_unwritten(ex);
3234
3235 /*
3236 * path may lead to new leaf, not to original leaf any more
3237 * after ext4_ext_insert_extent() returns,
3238 */
3239 err = ext4_ext_dirty(handle, inode, path + depth);
3240 if (err)
3241 goto fix_extent_len;
3242
3243 ex2 = &newex;
3244 ex2->ee_block = cpu_to_le32(split);
3245 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
3246 ext4_ext_store_pblock(ex2, newblock);
3247 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3248 ext4_ext_mark_unwritten(ex2);
3249
3250 err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
3251 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3252 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3253 if (split_flag & EXT4_EXT_DATA_VALID1) {
3254 err = ext4_ext_zeroout(inode, ex2);
3255 zero_ex.ee_block = ex2->ee_block;
3256 zero_ex.ee_len = cpu_to_le16(
3257 ext4_ext_get_actual_len(ex2));
3258 ext4_ext_store_pblock(&zero_ex,
3259 ext4_ext_pblock(ex2));
3260 } else {
3261 err = ext4_ext_zeroout(inode, ex);
3262 zero_ex.ee_block = ex->ee_block;
3263 zero_ex.ee_len = cpu_to_le16(
3264 ext4_ext_get_actual_len(ex));
3265 ext4_ext_store_pblock(&zero_ex,
3266 ext4_ext_pblock(ex));
3267 }
3268 } else {
3269 err = ext4_ext_zeroout(inode, &orig_ex);
3270 zero_ex.ee_block = orig_ex.ee_block;
3271 zero_ex.ee_len = cpu_to_le16(
3272 ext4_ext_get_actual_len(&orig_ex));
3273 ext4_ext_store_pblock(&zero_ex,
3274 ext4_ext_pblock(&orig_ex));
3275 }
3276
3277 if (err)
3278 goto fix_extent_len;
3279 /* update the extent length and mark as initialized */
3280 ex->ee_len = cpu_to_le16(ee_len);
3281 ext4_ext_try_to_merge(handle, inode, path, ex);
3282 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3283 if (err)
3284 goto fix_extent_len;
3285
3286 /* update extent status tree */
3287 err = ext4_zeroout_es(inode, &zero_ex);
3288
3289 goto out;
3290 } else if (err)
3291 goto fix_extent_len;
3292
3293out:
3294 ext4_ext_show_leaf(inode, path);
3295 return err;
3296
3297fix_extent_len:
3298 ex->ee_len = orig_ex.ee_len;
3299 ext4_ext_dirty(handle, inode, path + path->p_depth);
3300 return err;
3301}
3302
3303/*
3304 * ext4_split_extents() splits an extent and mark extent which is covered
3305 * by @map as split_flags indicates
3306 *
3307 * It may result in splitting the extent into multiple extents (up to three)
3308 * There are three possibilities:
3309 * a> There is no split required
3310 * b> Splits in two extents: Split is happening at either end of the extent
3311 * c> Splits in three extents: Somone is splitting in middle of the extent
3312 *
3313 */
3314static int ext4_split_extent(handle_t *handle,
3315 struct inode *inode,
3316 struct ext4_ext_path **ppath,
3317 struct ext4_map_blocks *map,
3318 int split_flag,
3319 int flags)
3320{
3321 struct ext4_ext_path *path = *ppath;
3322 ext4_lblk_t ee_block;
3323 struct ext4_extent *ex;
3324 unsigned int ee_len, depth;
3325 int err = 0;
3326 int unwritten;
3327 int split_flag1, flags1;
3328 int allocated = map->m_len;
3329
3330 depth = ext_depth(inode);
3331 ex = path[depth].p_ext;
3332 ee_block = le32_to_cpu(ex->ee_block);
3333 ee_len = ext4_ext_get_actual_len(ex);
3334 unwritten = ext4_ext_is_unwritten(ex);
3335
3336 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3337 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3338 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3339 if (unwritten)
3340 split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
3341 EXT4_EXT_MARK_UNWRIT2;
3342 if (split_flag & EXT4_EXT_DATA_VALID2)
3343 split_flag1 |= EXT4_EXT_DATA_VALID1;
3344 err = ext4_split_extent_at(handle, inode, ppath,
3345 map->m_lblk + map->m_len, split_flag1, flags1);
3346 if (err)
3347 goto out;
3348 } else {
3349 allocated = ee_len - (map->m_lblk - ee_block);
3350 }
3351 /*
3352 * Update path is required because previous ext4_split_extent_at() may
3353 * result in split of original leaf or extent zeroout.
3354 */
3355 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3356 if (IS_ERR(path))
3357 return PTR_ERR(path);
3358 depth = ext_depth(inode);
3359 ex = path[depth].p_ext;
3360 if (!ex) {
3361 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3362 (unsigned long) map->m_lblk);
3363 return -EFSCORRUPTED;
3364 }
3365 unwritten = ext4_ext_is_unwritten(ex);
3366 split_flag1 = 0;
3367
3368 if (map->m_lblk >= ee_block) {
3369 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3370 if (unwritten) {
3371 split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
3372 split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3373 EXT4_EXT_MARK_UNWRIT2);
3374 }
3375 err = ext4_split_extent_at(handle, inode, ppath,
3376 map->m_lblk, split_flag1, flags);
3377 if (err)
3378 goto out;
3379 }
3380
3381 ext4_ext_show_leaf(inode, path);
3382out:
3383 return err ? err : allocated;
3384}
3385
3386/*
3387 * This function is called by ext4_ext_map_blocks() if someone tries to write
3388 * to an unwritten extent. It may result in splitting the unwritten
3389 * extent into multiple extents (up to three - one initialized and two
3390 * unwritten).
3391 * There are three possibilities:
3392 * a> There is no split required: Entire extent should be initialized
3393 * b> Splits in two extents: Write is happening at either end of the extent
3394 * c> Splits in three extents: Somone is writing in middle of the extent
3395 *
3396 * Pre-conditions:
3397 * - The extent pointed to by 'path' is unwritten.
3398 * - The extent pointed to by 'path' contains a superset
3399 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3400 *
3401 * Post-conditions on success:
3402 * - the returned value is the number of blocks beyond map->l_lblk
3403 * that are allocated and initialized.
3404 * It is guaranteed to be >= map->m_len.
3405 */
3406static int ext4_ext_convert_to_initialized(handle_t *handle,
3407 struct inode *inode,
3408 struct ext4_map_blocks *map,
3409 struct ext4_ext_path **ppath,
3410 int flags)
3411{
3412 struct ext4_ext_path *path = *ppath;
3413 struct ext4_sb_info *sbi;
3414 struct ext4_extent_header *eh;
3415 struct ext4_map_blocks split_map;
3416 struct ext4_extent zero_ex;
3417 struct ext4_extent *ex, *abut_ex;
3418 ext4_lblk_t ee_block, eof_block;
3419 unsigned int ee_len, depth, map_len = map->m_len;
3420 int allocated = 0, max_zeroout = 0;
3421 int err = 0;
3422 int split_flag = 0;
3423
3424 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3425 "block %llu, max_blocks %u\n", inode->i_ino,
3426 (unsigned long long)map->m_lblk, map_len);
3427
3428 sbi = EXT4_SB(inode->i_sb);
3429 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3430 inode->i_sb->s_blocksize_bits;
3431 if (eof_block < map->m_lblk + map_len)
3432 eof_block = map->m_lblk + map_len;
3433
3434 depth = ext_depth(inode);
3435 eh = path[depth].p_hdr;
3436 ex = path[depth].p_ext;
3437 ee_block = le32_to_cpu(ex->ee_block);
3438 ee_len = ext4_ext_get_actual_len(ex);
3439 zero_ex.ee_len = 0;
3440
3441 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3442
3443 /* Pre-conditions */
3444 BUG_ON(!ext4_ext_is_unwritten(ex));
3445 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3446
3447 /*
3448 * Attempt to transfer newly initialized blocks from the currently
3449 * unwritten extent to its neighbor. This is much cheaper
3450 * than an insertion followed by a merge as those involve costly
3451 * memmove() calls. Transferring to the left is the common case in
3452 * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3453 * followed by append writes.
3454 *
3455 * Limitations of the current logic:
3456 * - L1: we do not deal with writes covering the whole extent.
3457 * This would require removing the extent if the transfer
3458 * is possible.
3459 * - L2: we only attempt to merge with an extent stored in the
3460 * same extent tree node.
3461 */
3462 if ((map->m_lblk == ee_block) &&
3463 /* See if we can merge left */
3464 (map_len < ee_len) && /*L1*/
3465 (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/
3466 ext4_lblk_t prev_lblk;
3467 ext4_fsblk_t prev_pblk, ee_pblk;
3468 unsigned int prev_len;
3469
3470 abut_ex = ex - 1;
3471 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3472 prev_len = ext4_ext_get_actual_len(abut_ex);
3473 prev_pblk = ext4_ext_pblock(abut_ex);
3474 ee_pblk = ext4_ext_pblock(ex);
3475
3476 /*
3477 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3478 * upon those conditions:
3479 * - C1: abut_ex is initialized,
3480 * - C2: abut_ex is logically abutting ex,
3481 * - C3: abut_ex is physically abutting ex,
3482 * - C4: abut_ex can receive the additional blocks without
3483 * overflowing the (initialized) length limit.
3484 */
3485 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3486 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3487 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3488 (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3489 err = ext4_ext_get_access(handle, inode, path + depth);
3490 if (err)
3491 goto out;
3492
3493 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3494 map, ex, abut_ex);
3495
3496 /* Shift the start of ex by 'map_len' blocks */
3497 ex->ee_block = cpu_to_le32(ee_block + map_len);
3498 ext4_ext_store_pblock(ex, ee_pblk + map_len);
3499 ex->ee_len = cpu_to_le16(ee_len - map_len);
3500 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3501
3502 /* Extend abut_ex by 'map_len' blocks */
3503 abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3504
3505 /* Result: number of initialized blocks past m_lblk */
3506 allocated = map_len;
3507 }
3508 } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3509 (map_len < ee_len) && /*L1*/
3510 ex < EXT_LAST_EXTENT(eh)) { /*L2*/
3511 /* See if we can merge right */
3512 ext4_lblk_t next_lblk;
3513 ext4_fsblk_t next_pblk, ee_pblk;
3514 unsigned int next_len;
3515
3516 abut_ex = ex + 1;
3517 next_lblk = le32_to_cpu(abut_ex->ee_block);
3518 next_len = ext4_ext_get_actual_len(abut_ex);
3519 next_pblk = ext4_ext_pblock(abut_ex);
3520 ee_pblk = ext4_ext_pblock(ex);
3521
3522 /*
3523 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3524 * upon those conditions:
3525 * - C1: abut_ex is initialized,
3526 * - C2: abut_ex is logically abutting ex,
3527 * - C3: abut_ex is physically abutting ex,
3528 * - C4: abut_ex can receive the additional blocks without
3529 * overflowing the (initialized) length limit.
3530 */
3531 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3532 ((map->m_lblk + map_len) == next_lblk) && /*C2*/
3533 ((ee_pblk + ee_len) == next_pblk) && /*C3*/
3534 (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3535 err = ext4_ext_get_access(handle, inode, path + depth);
3536 if (err)
3537 goto out;
3538
3539 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3540 map, ex, abut_ex);
3541
3542 /* Shift the start of abut_ex by 'map_len' blocks */
3543 abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3544 ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3545 ex->ee_len = cpu_to_le16(ee_len - map_len);
3546 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3547
3548 /* Extend abut_ex by 'map_len' blocks */
3549 abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3550
3551 /* Result: number of initialized blocks past m_lblk */
3552 allocated = map_len;
3553 }
3554 }
3555 if (allocated) {
3556 /* Mark the block containing both extents as dirty */
3557 ext4_ext_dirty(handle, inode, path + depth);
3558
3559 /* Update path to point to the right extent */
3560 path[depth].p_ext = abut_ex;
3561 goto out;
3562 } else
3563 allocated = ee_len - (map->m_lblk - ee_block);
3564
3565 WARN_ON(map->m_lblk < ee_block);
3566 /*
3567 * It is safe to convert extent to initialized via explicit
3568 * zeroout only if extent is fully inside i_size or new_size.
3569 */
3570 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3571
3572 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3573 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3574 (inode->i_sb->s_blocksize_bits - 10);
3575
3576 if (ext4_encrypted_inode(inode))
3577 max_zeroout = 0;
3578
3579 /* If extent is less than s_max_zeroout_kb, zeroout directly */
3580 if (max_zeroout && (ee_len <= max_zeroout)) {
3581 err = ext4_ext_zeroout(inode, ex);
3582 if (err)
3583 goto out;
3584 zero_ex.ee_block = ex->ee_block;
3585 zero_ex.ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex));
3586 ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex));
3587
3588 err = ext4_ext_get_access(handle, inode, path + depth);
3589 if (err)
3590 goto out;
3591 ext4_ext_mark_initialized(ex);
3592 ext4_ext_try_to_merge(handle, inode, path, ex);
3593 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3594 goto out;
3595 }
3596
3597 /*
3598 * four cases:
3599 * 1. split the extent into three extents.
3600 * 2. split the extent into two extents, zeroout the first half.
3601 * 3. split the extent into two extents, zeroout the second half.
3602 * 4. split the extent into two extents with out zeroout.
3603 */
3604 split_map.m_lblk = map->m_lblk;
3605 split_map.m_len = map->m_len;
3606
3607 if (max_zeroout && (allocated > map->m_len)) {
3608 if (allocated <= max_zeroout) {
3609 /* case 3 */
3610 zero_ex.ee_block =
3611 cpu_to_le32(map->m_lblk);
3612 zero_ex.ee_len = cpu_to_le16(allocated);
3613 ext4_ext_store_pblock(&zero_ex,
3614 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
3615 err = ext4_ext_zeroout(inode, &zero_ex);
3616 if (err)
3617 goto out;
3618 split_map.m_lblk = map->m_lblk;
3619 split_map.m_len = allocated;
3620 } else if (map->m_lblk - ee_block + map->m_len < max_zeroout) {
3621 /* case 2 */
3622 if (map->m_lblk != ee_block) {
3623 zero_ex.ee_block = ex->ee_block;
3624 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
3625 ee_block);
3626 ext4_ext_store_pblock(&zero_ex,
3627 ext4_ext_pblock(ex));
3628 err = ext4_ext_zeroout(inode, &zero_ex);
3629 if (err)
3630 goto out;
3631 }
3632
3633 split_map.m_lblk = ee_block;
3634 split_map.m_len = map->m_lblk - ee_block + map->m_len;
3635 allocated = map->m_len;
3636 }
3637 }
3638
3639 err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
3640 flags);
3641 if (err > 0)
3642 err = 0;
3643out:
3644 /* If we have gotten a failure, don't zero out status tree */
3645 if (!err)
3646 err = ext4_zeroout_es(inode, &zero_ex);
3647 return err ? err : allocated;
3648}
3649
3650/*
3651 * This function is called by ext4_ext_map_blocks() from
3652 * ext4_get_blocks_dio_write() when DIO to write
3653 * to an unwritten extent.
3654 *
3655 * Writing to an unwritten extent may result in splitting the unwritten
3656 * extent into multiple initialized/unwritten extents (up to three)
3657 * There are three possibilities:
3658 * a> There is no split required: Entire extent should be unwritten
3659 * b> Splits in two extents: Write is happening at either end of the extent
3660 * c> Splits in three extents: Somone is writing in middle of the extent
3661 *
3662 * This works the same way in the case of initialized -> unwritten conversion.
3663 *
3664 * One of more index blocks maybe needed if the extent tree grow after
3665 * the unwritten extent split. To prevent ENOSPC occur at the IO
3666 * complete, we need to split the unwritten extent before DIO submit
3667 * the IO. The unwritten extent called at this time will be split
3668 * into three unwritten extent(at most). After IO complete, the part
3669 * being filled will be convert to initialized by the end_io callback function
3670 * via ext4_convert_unwritten_extents().
3671 *
3672 * Returns the size of unwritten extent to be written on success.
3673 */
3674static int ext4_split_convert_extents(handle_t *handle,
3675 struct inode *inode,
3676 struct ext4_map_blocks *map,
3677 struct ext4_ext_path **ppath,
3678 int flags)
3679{
3680 struct ext4_ext_path *path = *ppath;
3681 ext4_lblk_t eof_block;
3682 ext4_lblk_t ee_block;
3683 struct ext4_extent *ex;
3684 unsigned int ee_len;
3685 int split_flag = 0, depth;
3686
3687 ext_debug("%s: inode %lu, logical block %llu, max_blocks %u\n",
3688 __func__, inode->i_ino,
3689 (unsigned long long)map->m_lblk, map->m_len);
3690
3691 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3692 inode->i_sb->s_blocksize_bits;
3693 if (eof_block < map->m_lblk + map->m_len)
3694 eof_block = map->m_lblk + map->m_len;
3695 /*
3696 * It is safe to convert extent to initialized via explicit
3697 * zeroout only if extent is fully insde i_size or new_size.
3698 */
3699 depth = ext_depth(inode);
3700 ex = path[depth].p_ext;
3701 ee_block = le32_to_cpu(ex->ee_block);
3702 ee_len = ext4_ext_get_actual_len(ex);
3703
3704 /* Convert to unwritten */
3705 if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
3706 split_flag |= EXT4_EXT_DATA_VALID1;
3707 /* Convert to initialized */
3708 } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
3709 split_flag |= ee_block + ee_len <= eof_block ?
3710 EXT4_EXT_MAY_ZEROOUT : 0;
3711 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
3712 }
3713 flags |= EXT4_GET_BLOCKS_PRE_IO;
3714 return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
3715}
3716
3717static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3718 struct inode *inode,
3719 struct ext4_map_blocks *map,
3720 struct ext4_ext_path **ppath)
3721{
3722 struct ext4_ext_path *path = *ppath;
3723 struct ext4_extent *ex;
3724 ext4_lblk_t ee_block;
3725 unsigned int ee_len;
3726 int depth;
3727 int err = 0;
3728
3729 depth = ext_depth(inode);
3730 ex = path[depth].p_ext;
3731 ee_block = le32_to_cpu(ex->ee_block);
3732 ee_len = ext4_ext_get_actual_len(ex);
3733
3734 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3735 "block %llu, max_blocks %u\n", inode->i_ino,
3736 (unsigned long long)ee_block, ee_len);
3737
3738 /* If extent is larger than requested it is a clear sign that we still
3739 * have some extent state machine issues left. So extent_split is still
3740 * required.
3741 * TODO: Once all related issues will be fixed this situation should be
3742 * illegal.
3743 */
3744 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3745#ifdef EXT4_DEBUG
3746 ext4_warning("Inode (%ld) finished: extent logical block %llu,"
3747 " len %u; IO logical block %llu, len %u",
3748 inode->i_ino, (unsigned long long)ee_block, ee_len,
3749 (unsigned long long)map->m_lblk, map->m_len);
3750#endif
3751 err = ext4_split_convert_extents(handle, inode, map, ppath,
3752 EXT4_GET_BLOCKS_CONVERT);
3753 if (err < 0)
3754 return err;
3755 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3756 if (IS_ERR(path))
3757 return PTR_ERR(path);
3758 depth = ext_depth(inode);
3759 ex = path[depth].p_ext;
3760 }
3761
3762 err = ext4_ext_get_access(handle, inode, path + depth);
3763 if (err)
3764 goto out;
3765 /* first mark the extent as initialized */
3766 ext4_ext_mark_initialized(ex);
3767
3768 /* note: ext4_ext_correct_indexes() isn't needed here because
3769 * borders are not changed
3770 */
3771 ext4_ext_try_to_merge(handle, inode, path, ex);
3772
3773 /* Mark modified extent as dirty */
3774 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3775out:
3776 ext4_ext_show_leaf(inode, path);
3777 return err;
3778}
3779
3780/*
3781 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3782 */
3783static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3784 ext4_lblk_t lblk,
3785 struct ext4_ext_path *path,
3786 unsigned int len)
3787{
3788 int i, depth;
3789 struct ext4_extent_header *eh;
3790 struct ext4_extent *last_ex;
3791
3792 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3793 return 0;
3794
3795 depth = ext_depth(inode);
3796 eh = path[depth].p_hdr;
3797
3798 /*
3799 * We're going to remove EOFBLOCKS_FL entirely in future so we
3800 * do not care for this case anymore. Simply remove the flag
3801 * if there are no extents.
3802 */
3803 if (unlikely(!eh->eh_entries))
3804 goto out;
3805 last_ex = EXT_LAST_EXTENT(eh);
3806 /*
3807 * We should clear the EOFBLOCKS_FL flag if we are writing the
3808 * last block in the last extent in the file. We test this by
3809 * first checking to see if the caller to
3810 * ext4_ext_get_blocks() was interested in the last block (or
3811 * a block beyond the last block) in the current extent. If
3812 * this turns out to be false, we can bail out from this
3813 * function immediately.
3814 */
3815 if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3816 ext4_ext_get_actual_len(last_ex))
3817 return 0;
3818 /*
3819 * If the caller does appear to be planning to write at or
3820 * beyond the end of the current extent, we then test to see
3821 * if the current extent is the last extent in the file, by
3822 * checking to make sure it was reached via the rightmost node
3823 * at each level of the tree.
3824 */
3825 for (i = depth-1; i >= 0; i--)
3826 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3827 return 0;
3828out:
3829 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3830 return ext4_mark_inode_dirty(handle, inode);
3831}
3832
3833/**
3834 * ext4_find_delalloc_range: find delayed allocated block in the given range.
3835 *
3836 * Return 1 if there is a delalloc block in the range, otherwise 0.
3837 */
3838int ext4_find_delalloc_range(struct inode *inode,
3839 ext4_lblk_t lblk_start,
3840 ext4_lblk_t lblk_end)
3841{
3842 struct extent_status es;
3843
3844 ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es);
3845 if (es.es_len == 0)
3846 return 0; /* there is no delay extent in this tree */
3847 else if (es.es_lblk <= lblk_start &&
3848 lblk_start < es.es_lblk + es.es_len)
3849 return 1;
3850 else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end)
3851 return 1;
3852 else
3853 return 0;
3854}
3855
3856int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
3857{
3858 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3859 ext4_lblk_t lblk_start, lblk_end;
3860 lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
3861 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3862
3863 return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
3864}
3865
3866/**
3867 * Determines how many complete clusters (out of those specified by the 'map')
3868 * are under delalloc and were reserved quota for.
3869 * This function is called when we are writing out the blocks that were
3870 * originally written with their allocation delayed, but then the space was
3871 * allocated using fallocate() before the delayed allocation could be resolved.
3872 * The cases to look for are:
3873 * ('=' indicated delayed allocated blocks
3874 * '-' indicates non-delayed allocated blocks)
3875 * (a) partial clusters towards beginning and/or end outside of allocated range
3876 * are not delalloc'ed.
3877 * Ex:
3878 * |----c---=|====c====|====c====|===-c----|
3879 * |++++++ allocated ++++++|
3880 * ==> 4 complete clusters in above example
3881 *
3882 * (b) partial cluster (outside of allocated range) towards either end is
3883 * marked for delayed allocation. In this case, we will exclude that
3884 * cluster.
3885 * Ex:
3886 * |----====c========|========c========|
3887 * |++++++ allocated ++++++|
3888 * ==> 1 complete clusters in above example
3889 *
3890 * Ex:
3891 * |================c================|
3892 * |++++++ allocated ++++++|
3893 * ==> 0 complete clusters in above example
3894 *
3895 * The ext4_da_update_reserve_space will be called only if we
3896 * determine here that there were some "entire" clusters that span
3897 * this 'allocated' range.
3898 * In the non-bigalloc case, this function will just end up returning num_blks
3899 * without ever calling ext4_find_delalloc_range.
3900 */
3901static unsigned int
3902get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3903 unsigned int num_blks)
3904{
3905 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3906 ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3907 ext4_lblk_t lblk_from, lblk_to, c_offset;
3908 unsigned int allocated_clusters = 0;
3909
3910 alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3911 alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3912
3913 /* max possible clusters for this allocation */
3914 allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3915
3916 trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3917
3918 /* Check towards left side */
3919 c_offset = EXT4_LBLK_COFF(sbi, lblk_start);
3920 if (c_offset) {
3921 lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start);
3922 lblk_to = lblk_from + c_offset - 1;
3923
3924 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3925 allocated_clusters--;
3926 }
3927
3928 /* Now check towards right. */
3929 c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks);
3930 if (allocated_clusters && c_offset) {
3931 lblk_from = lblk_start + num_blks;
3932 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3933
3934 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3935 allocated_clusters--;
3936 }
3937
3938 return allocated_clusters;
3939}
3940
3941static int
3942convert_initialized_extent(handle_t *handle, struct inode *inode,
3943 struct ext4_map_blocks *map,
3944 struct ext4_ext_path **ppath,
3945 unsigned int allocated)
3946{
3947 struct ext4_ext_path *path = *ppath;
3948 struct ext4_extent *ex;
3949 ext4_lblk_t ee_block;
3950 unsigned int ee_len;
3951 int depth;
3952 int err = 0;
3953
3954 /*
3955 * Make sure that the extent is no bigger than we support with
3956 * unwritten extent
3957 */
3958 if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
3959 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
3960
3961 depth = ext_depth(inode);
3962 ex = path[depth].p_ext;
3963 ee_block = le32_to_cpu(ex->ee_block);
3964 ee_len = ext4_ext_get_actual_len(ex);
3965
3966 ext_debug("%s: inode %lu, logical"
3967 "block %llu, max_blocks %u\n", __func__, inode->i_ino,
3968 (unsigned long long)ee_block, ee_len);
3969
3970 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3971 err = ext4_split_convert_extents(handle, inode, map, ppath,
3972 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
3973 if (err < 0)
3974 return err;
3975 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3976 if (IS_ERR(path))
3977 return PTR_ERR(path);
3978 depth = ext_depth(inode);
3979 ex = path[depth].p_ext;
3980 if (!ex) {
3981 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3982 (unsigned long) map->m_lblk);
3983 return -EFSCORRUPTED;
3984 }
3985 }
3986
3987 err = ext4_ext_get_access(handle, inode, path + depth);
3988 if (err)
3989 return err;
3990 /* first mark the extent as unwritten */
3991 ext4_ext_mark_unwritten(ex);
3992
3993 /* note: ext4_ext_correct_indexes() isn't needed here because
3994 * borders are not changed
3995 */
3996 ext4_ext_try_to_merge(handle, inode, path, ex);
3997
3998 /* Mark modified extent as dirty */
3999 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
4000 if (err)
4001 return err;
4002 ext4_ext_show_leaf(inode, path);
4003
4004 ext4_update_inode_fsync_trans(handle, inode, 1);
4005 err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len);
4006 if (err)
4007 return err;
4008 map->m_flags |= EXT4_MAP_UNWRITTEN;
4009 if (allocated > map->m_len)
4010 allocated = map->m_len;
4011 map->m_len = allocated;
4012 return allocated;
4013}
4014
4015static int
4016ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
4017 struct ext4_map_blocks *map,
4018 struct ext4_ext_path **ppath, int flags,
4019 unsigned int allocated, ext4_fsblk_t newblock)
4020{
4021 struct ext4_ext_path *path = *ppath;
4022 int ret = 0;
4023 int err = 0;
4024
4025 ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical "
4026 "block %llu, max_blocks %u, flags %x, allocated %u\n",
4027 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
4028 flags, allocated);
4029 ext4_ext_show_leaf(inode, path);
4030
4031 /*
4032 * When writing into unwritten space, we should not fail to
4033 * allocate metadata blocks for the new extent block if needed.
4034 */
4035 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
4036
4037 trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
4038 allocated, newblock);
4039
4040 /* get_block() before submit the IO, split the extent */
4041 if (flags & EXT4_GET_BLOCKS_PRE_IO) {
4042 ret = ext4_split_convert_extents(handle, inode, map, ppath,
4043 flags | EXT4_GET_BLOCKS_CONVERT);
4044 if (ret <= 0)
4045 goto out;
4046 map->m_flags |= EXT4_MAP_UNWRITTEN;
4047 goto out;
4048 }
4049 /* IO end_io complete, convert the filled extent to written */
4050 if (flags & EXT4_GET_BLOCKS_CONVERT) {
4051 if (flags & EXT4_GET_BLOCKS_ZERO) {
4052 if (allocated > map->m_len)
4053 allocated = map->m_len;
4054 err = ext4_issue_zeroout(inode, map->m_lblk, newblock,
4055 allocated);
4056 if (err < 0)
4057 goto out2;
4058 }
4059 ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
4060 ppath);
4061 if (ret >= 0) {
4062 ext4_update_inode_fsync_trans(handle, inode, 1);
4063 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4064 path, map->m_len);
4065 } else
4066 err = ret;
4067 map->m_flags |= EXT4_MAP_MAPPED;
4068 map->m_pblk = newblock;
4069 if (allocated > map->m_len)
4070 allocated = map->m_len;
4071 map->m_len = allocated;
4072 goto out2;
4073 }
4074 /* buffered IO case */
4075 /*
4076 * repeat fallocate creation request
4077 * we already have an unwritten extent
4078 */
4079 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
4080 map->m_flags |= EXT4_MAP_UNWRITTEN;
4081 goto map_out;
4082 }
4083
4084 /* buffered READ or buffered write_begin() lookup */
4085 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4086 /*
4087 * We have blocks reserved already. We
4088 * return allocated blocks so that delalloc
4089 * won't do block reservation for us. But
4090 * the buffer head will be unmapped so that
4091 * a read from the block returns 0s.
4092 */
4093 map->m_flags |= EXT4_MAP_UNWRITTEN;
4094 goto out1;
4095 }
4096
4097 /* buffered write, writepage time, convert*/
4098 ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags);
4099 if (ret >= 0)
4100 ext4_update_inode_fsync_trans(handle, inode, 1);
4101out:
4102 if (ret <= 0) {
4103 err = ret;
4104 goto out2;
4105 } else
4106 allocated = ret;
4107 map->m_flags |= EXT4_MAP_NEW;
4108 /*
4109 * if we allocated more blocks than requested
4110 * we need to make sure we unmap the extra block
4111 * allocated. The actual needed block will get
4112 * unmapped later when we find the buffer_head marked
4113 * new.
4114 */
4115 if (allocated > map->m_len) {
4116 clean_bdev_aliases(inode->i_sb->s_bdev, newblock + map->m_len,
4117 allocated - map->m_len);
4118 allocated = map->m_len;
4119 }
4120 map->m_len = allocated;
4121
4122 /*
4123 * If we have done fallocate with the offset that is already
4124 * delayed allocated, we would have block reservation
4125 * and quota reservation done in the delayed write path.
4126 * But fallocate would have already updated quota and block
4127 * count for this offset. So cancel these reservation
4128 */
4129 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4130 unsigned int reserved_clusters;
4131 reserved_clusters = get_reserved_cluster_alloc(inode,
4132 map->m_lblk, map->m_len);
4133 if (reserved_clusters)
4134 ext4_da_update_reserve_space(inode,
4135 reserved_clusters,
4136 0);
4137 }
4138
4139map_out:
4140 map->m_flags |= EXT4_MAP_MAPPED;
4141 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
4142 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
4143 map->m_len);
4144 if (err < 0)
4145 goto out2;
4146 }
4147out1:
4148 if (allocated > map->m_len)
4149 allocated = map->m_len;
4150 ext4_ext_show_leaf(inode, path);
4151 map->m_pblk = newblock;
4152 map->m_len = allocated;
4153out2:
4154 return err ? err : allocated;
4155}
4156
4157/*
4158 * get_implied_cluster_alloc - check to see if the requested
4159 * allocation (in the map structure) overlaps with a cluster already
4160 * allocated in an extent.
4161 * @sb The filesystem superblock structure
4162 * @map The requested lblk->pblk mapping
4163 * @ex The extent structure which might contain an implied
4164 * cluster allocation
4165 *
4166 * This function is called by ext4_ext_map_blocks() after we failed to
4167 * find blocks that were already in the inode's extent tree. Hence,
4168 * we know that the beginning of the requested region cannot overlap
4169 * the extent from the inode's extent tree. There are three cases we
4170 * want to catch. The first is this case:
4171 *
4172 * |--- cluster # N--|
4173 * |--- extent ---| |---- requested region ---|
4174 * |==========|
4175 *
4176 * The second case that we need to test for is this one:
4177 *
4178 * |--------- cluster # N ----------------|
4179 * |--- requested region --| |------- extent ----|
4180 * |=======================|
4181 *
4182 * The third case is when the requested region lies between two extents
4183 * within the same cluster:
4184 * |------------- cluster # N-------------|
4185 * |----- ex -----| |---- ex_right ----|
4186 * |------ requested region ------|
4187 * |================|
4188 *
4189 * In each of the above cases, we need to set the map->m_pblk and
4190 * map->m_len so it corresponds to the return the extent labelled as
4191 * "|====|" from cluster #N, since it is already in use for data in
4192 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
4193 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
4194 * as a new "allocated" block region. Otherwise, we will return 0 and
4195 * ext4_ext_map_blocks() will then allocate one or more new clusters
4196 * by calling ext4_mb_new_blocks().
4197 */
4198static int get_implied_cluster_alloc(struct super_block *sb,
4199 struct ext4_map_blocks *map,
4200 struct ext4_extent *ex,
4201 struct ext4_ext_path *path)
4202{
4203 struct ext4_sb_info *sbi = EXT4_SB(sb);
4204 ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4205 ext4_lblk_t ex_cluster_start, ex_cluster_end;
4206 ext4_lblk_t rr_cluster_start;
4207 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4208 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4209 unsigned short ee_len = ext4_ext_get_actual_len(ex);
4210
4211 /* The extent passed in that we are trying to match */
4212 ex_cluster_start = EXT4_B2C(sbi, ee_block);
4213 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
4214
4215 /* The requested region passed into ext4_map_blocks() */
4216 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
4217
4218 if ((rr_cluster_start == ex_cluster_end) ||
4219 (rr_cluster_start == ex_cluster_start)) {
4220 if (rr_cluster_start == ex_cluster_end)
4221 ee_start += ee_len - 1;
4222 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
4223 map->m_len = min(map->m_len,
4224 (unsigned) sbi->s_cluster_ratio - c_offset);
4225 /*
4226 * Check for and handle this case:
4227 *
4228 * |--------- cluster # N-------------|
4229 * |------- extent ----|
4230 * |--- requested region ---|
4231 * |===========|
4232 */
4233
4234 if (map->m_lblk < ee_block)
4235 map->m_len = min(map->m_len, ee_block - map->m_lblk);
4236
4237 /*
4238 * Check for the case where there is already another allocated
4239 * block to the right of 'ex' but before the end of the cluster.
4240 *
4241 * |------------- cluster # N-------------|
4242 * |----- ex -----| |---- ex_right ----|
4243 * |------ requested region ------|
4244 * |================|
4245 */
4246 if (map->m_lblk > ee_block) {
4247 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4248 map->m_len = min(map->m_len, next - map->m_lblk);
4249 }
4250
4251 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4252 return 1;
4253 }
4254
4255 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4256 return 0;
4257}
4258
4259
4260/*
4261 * Block allocation/map/preallocation routine for extents based files
4262 *
4263 *
4264 * Need to be called with
4265 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4266 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4267 *
4268 * return > 0, number of of blocks already mapped/allocated
4269 * if create == 0 and these are pre-allocated blocks
4270 * buffer head is unmapped
4271 * otherwise blocks are mapped
4272 *
4273 * return = 0, if plain look up failed (blocks have not been allocated)
4274 * buffer head is unmapped
4275 *
4276 * return < 0, error case.
4277 */
4278int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4279 struct ext4_map_blocks *map, int flags)
4280{
4281 struct ext4_ext_path *path = NULL;
4282 struct ext4_extent newex, *ex, *ex2;
4283 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4284 ext4_fsblk_t newblock = 0;
4285 int free_on_err = 0, err = 0, depth, ret;
4286 unsigned int allocated = 0, offset = 0;
4287 unsigned int allocated_clusters = 0;
4288 struct ext4_allocation_request ar;
4289 ext4_lblk_t cluster_offset;
4290 bool map_from_cluster = false;
4291
4292 ext_debug("blocks %u/%u requested for inode %lu\n",
4293 map->m_lblk, map->m_len, inode->i_ino);
4294 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4295
4296 /* find extent for this block */
4297 path = ext4_find_extent(inode, map->m_lblk, NULL, 0);
4298 if (IS_ERR(path)) {
4299 err = PTR_ERR(path);
4300 path = NULL;
4301 goto out2;
4302 }
4303
4304 depth = ext_depth(inode);
4305
4306 /*
4307 * consistent leaf must not be empty;
4308 * this situation is possible, though, _during_ tree modification;
4309 * this is why assert can't be put in ext4_find_extent()
4310 */
4311 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4312 EXT4_ERROR_INODE(inode, "bad extent address "
4313 "lblock: %lu, depth: %d pblock %lld",
4314 (unsigned long) map->m_lblk, depth,
4315 path[depth].p_block);
4316 err = -EFSCORRUPTED;
4317 goto out2;
4318 }
4319
4320 ex = path[depth].p_ext;
4321 if (ex) {
4322 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4323 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4324 unsigned short ee_len;
4325
4326
4327 /*
4328 * unwritten extents are treated as holes, except that
4329 * we split out initialized portions during a write.
4330 */
4331 ee_len = ext4_ext_get_actual_len(ex);
4332
4333 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4334
4335 /* if found extent covers block, simply return it */
4336 if (in_range(map->m_lblk, ee_block, ee_len)) {
4337 newblock = map->m_lblk - ee_block + ee_start;
4338 /* number of remaining blocks in the extent */
4339 allocated = ee_len - (map->m_lblk - ee_block);
4340 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
4341 ee_block, ee_len, newblock);
4342
4343 /*
4344 * If the extent is initialized check whether the
4345 * caller wants to convert it to unwritten.
4346 */
4347 if ((!ext4_ext_is_unwritten(ex)) &&
4348 (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
4349 allocated = convert_initialized_extent(
4350 handle, inode, map, &path,
4351 allocated);
4352 goto out2;
4353 } else if (!ext4_ext_is_unwritten(ex))
4354 goto out;
4355
4356 ret = ext4_ext_handle_unwritten_extents(
4357 handle, inode, map, &path, flags,
4358 allocated, newblock);
4359 if (ret < 0)
4360 err = ret;
4361 else
4362 allocated = ret;
4363 goto out2;
4364 }
4365 }
4366
4367 /*
4368 * requested block isn't allocated yet;
4369 * we couldn't try to create block if create flag is zero
4370 */
4371 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4372 ext4_lblk_t hole_start, hole_len;
4373
4374 hole_start = map->m_lblk;
4375 hole_len = ext4_ext_determine_hole(inode, path, &hole_start);
4376 /*
4377 * put just found gap into cache to speed up
4378 * subsequent requests
4379 */
4380 ext4_ext_put_gap_in_cache(inode, hole_start, hole_len);
4381
4382 /* Update hole_len to reflect hole size after map->m_lblk */
4383 if (hole_start != map->m_lblk)
4384 hole_len -= map->m_lblk - hole_start;
4385 map->m_pblk = 0;
4386 map->m_len = min_t(unsigned int, map->m_len, hole_len);
4387
4388 goto out2;
4389 }
4390
4391 /*
4392 * Okay, we need to do block allocation.
4393 */
4394 newex.ee_block = cpu_to_le32(map->m_lblk);
4395 cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4396
4397 /*
4398 * If we are doing bigalloc, check to see if the extent returned
4399 * by ext4_find_extent() implies a cluster we can use.
4400 */
4401 if (cluster_offset && ex &&
4402 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4403 ar.len = allocated = map->m_len;
4404 newblock = map->m_pblk;
4405 map_from_cluster = true;
4406 goto got_allocated_blocks;
4407 }
4408
4409 /* find neighbour allocated blocks */
4410 ar.lleft = map->m_lblk;
4411 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4412 if (err)
4413 goto out2;
4414 ar.lright = map->m_lblk;
4415 ex2 = NULL;
4416 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4417 if (err)
4418 goto out2;
4419
4420 /* Check if the extent after searching to the right implies a
4421 * cluster we can use. */
4422 if ((sbi->s_cluster_ratio > 1) && ex2 &&
4423 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
4424 ar.len = allocated = map->m_len;
4425 newblock = map->m_pblk;
4426 map_from_cluster = true;
4427 goto got_allocated_blocks;
4428 }
4429
4430 /*
4431 * See if request is beyond maximum number of blocks we can have in
4432 * a single extent. For an initialized extent this limit is
4433 * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
4434 * EXT_UNWRITTEN_MAX_LEN.
4435 */
4436 if (map->m_len > EXT_INIT_MAX_LEN &&
4437 !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4438 map->m_len = EXT_INIT_MAX_LEN;
4439 else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
4440 (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4441 map->m_len = EXT_UNWRITTEN_MAX_LEN;
4442
4443 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4444 newex.ee_len = cpu_to_le16(map->m_len);
4445 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4446 if (err)
4447 allocated = ext4_ext_get_actual_len(&newex);
4448 else
4449 allocated = map->m_len;
4450
4451 /* allocate new block */
4452 ar.inode = inode;
4453 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4454 ar.logical = map->m_lblk;
4455 /*
4456 * We calculate the offset from the beginning of the cluster
4457 * for the logical block number, since when we allocate a
4458 * physical cluster, the physical block should start at the
4459 * same offset from the beginning of the cluster. This is
4460 * needed so that future calls to get_implied_cluster_alloc()
4461 * work correctly.
4462 */
4463 offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4464 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4465 ar.goal -= offset;
4466 ar.logical -= offset;
4467 if (S_ISREG(inode->i_mode))
4468 ar.flags = EXT4_MB_HINT_DATA;
4469 else
4470 /* disable in-core preallocation for non-regular files */
4471 ar.flags = 0;
4472 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4473 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4474 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4475 ar.flags |= EXT4_MB_DELALLOC_RESERVED;
4476 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
4477 ar.flags |= EXT4_MB_USE_RESERVED;
4478 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4479 if (!newblock)
4480 goto out2;
4481 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4482 ar.goal, newblock, allocated);
4483 free_on_err = 1;
4484 allocated_clusters = ar.len;
4485 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4486 if (ar.len > allocated)
4487 ar.len = allocated;
4488
4489got_allocated_blocks:
4490 /* try to insert new extent into found leaf and return */
4491 ext4_ext_store_pblock(&newex, newblock + offset);
4492 newex.ee_len = cpu_to_le16(ar.len);
4493 /* Mark unwritten */
4494 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){
4495 ext4_ext_mark_unwritten(&newex);
4496 map->m_flags |= EXT4_MAP_UNWRITTEN;
4497 }
4498
4499 err = 0;
4500 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4501 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4502 path, ar.len);
4503 if (!err)
4504 err = ext4_ext_insert_extent(handle, inode, &path,
4505 &newex, flags);
4506
4507 if (err && free_on_err) {
4508 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4509 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4510 /* free data blocks we just allocated */
4511 /* not a good idea to call discard here directly,
4512 * but otherwise we'd need to call it every free() */
4513 ext4_discard_preallocations(inode);
4514 ext4_free_blocks(handle, inode, NULL, newblock,
4515 EXT4_C2B(sbi, allocated_clusters), fb_flags);
4516 goto out2;
4517 }
4518
4519 /* previous routine could use block we allocated */
4520 newblock = ext4_ext_pblock(&newex);
4521 allocated = ext4_ext_get_actual_len(&newex);
4522 if (allocated > map->m_len)
4523 allocated = map->m_len;
4524 map->m_flags |= EXT4_MAP_NEW;
4525
4526 /*
4527 * Update reserved blocks/metadata blocks after successful
4528 * block allocation which had been deferred till now.
4529 */
4530 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4531 unsigned int reserved_clusters;
4532 /*
4533 * Check how many clusters we had reserved this allocated range
4534 */
4535 reserved_clusters = get_reserved_cluster_alloc(inode,
4536 map->m_lblk, allocated);
4537 if (!map_from_cluster) {
4538 BUG_ON(allocated_clusters < reserved_clusters);
4539 if (reserved_clusters < allocated_clusters) {
4540 struct ext4_inode_info *ei = EXT4_I(inode);
4541 int reservation = allocated_clusters -
4542 reserved_clusters;
4543 /*
4544 * It seems we claimed few clusters outside of
4545 * the range of this allocation. We should give
4546 * it back to the reservation pool. This can
4547 * happen in the following case:
4548 *
4549 * * Suppose s_cluster_ratio is 4 (i.e., each
4550 * cluster has 4 blocks. Thus, the clusters
4551 * are [0-3],[4-7],[8-11]...
4552 * * First comes delayed allocation write for
4553 * logical blocks 10 & 11. Since there were no
4554 * previous delayed allocated blocks in the
4555 * range [8-11], we would reserve 1 cluster
4556 * for this write.
4557 * * Next comes write for logical blocks 3 to 8.
4558 * In this case, we will reserve 2 clusters
4559 * (for [0-3] and [4-7]; and not for [8-11] as
4560 * that range has a delayed allocated blocks.
4561 * Thus total reserved clusters now becomes 3.
4562 * * Now, during the delayed allocation writeout
4563 * time, we will first write blocks [3-8] and
4564 * allocate 3 clusters for writing these
4565 * blocks. Also, we would claim all these
4566 * three clusters above.
4567 * * Now when we come here to writeout the
4568 * blocks [10-11], we would expect to claim
4569 * the reservation of 1 cluster we had made
4570 * (and we would claim it since there are no
4571 * more delayed allocated blocks in the range
4572 * [8-11]. But our reserved cluster count had
4573 * already gone to 0.
4574 *
4575 * Thus, at the step 4 above when we determine
4576 * that there are still some unwritten delayed
4577 * allocated blocks outside of our current
4578 * block range, we should increment the
4579 * reserved clusters count so that when the
4580 * remaining blocks finally gets written, we
4581 * could claim them.
4582 */
4583 dquot_reserve_block(inode,
4584 EXT4_C2B(sbi, reservation));
4585 spin_lock(&ei->i_block_reservation_lock);
4586 ei->i_reserved_data_blocks += reservation;
4587 spin_unlock(&ei->i_block_reservation_lock);
4588 }
4589 /*
4590 * We will claim quota for all newly allocated blocks.
4591 * We're updating the reserved space *after* the
4592 * correction above so we do not accidentally free
4593 * all the metadata reservation because we might
4594 * actually need it later on.
4595 */
4596 ext4_da_update_reserve_space(inode, allocated_clusters,
4597 1);
4598 }
4599 }
4600
4601 /*
4602 * Cache the extent and update transaction to commit on fdatasync only
4603 * when it is _not_ an unwritten extent.
4604 */
4605 if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
4606 ext4_update_inode_fsync_trans(handle, inode, 1);
4607 else
4608 ext4_update_inode_fsync_trans(handle, inode, 0);
4609out:
4610 if (allocated > map->m_len)
4611 allocated = map->m_len;
4612 ext4_ext_show_leaf(inode, path);
4613 map->m_flags |= EXT4_MAP_MAPPED;
4614 map->m_pblk = newblock;
4615 map->m_len = allocated;
4616out2:
4617 ext4_ext_drop_refs(path);
4618 kfree(path);
4619
4620 trace_ext4_ext_map_blocks_exit(inode, flags, map,
4621 err ? err : allocated);
4622 return err ? err : allocated;
4623}
4624
4625int ext4_ext_truncate(handle_t *handle, struct inode *inode)
4626{
4627 struct super_block *sb = inode->i_sb;
4628 ext4_lblk_t last_block;
4629 int err = 0;
4630
4631 /*
4632 * TODO: optimization is possible here.
4633 * Probably we need not scan at all,
4634 * because page truncation is enough.
4635 */
4636
4637 /* we have to know where to truncate from in crash case */
4638 EXT4_I(inode)->i_disksize = inode->i_size;
4639 err = ext4_mark_inode_dirty(handle, inode);
4640 if (err)
4641 return err;
4642
4643 last_block = (inode->i_size + sb->s_blocksize - 1)
4644 >> EXT4_BLOCK_SIZE_BITS(sb);
4645retry:
4646 err = ext4_es_remove_extent(inode, last_block,
4647 EXT_MAX_BLOCKS - last_block);
4648 if (err == -ENOMEM) {
4649 cond_resched();
4650 congestion_wait(BLK_RW_ASYNC, HZ/50);
4651 goto retry;
4652 }
4653 if (err)
4654 return err;
4655 return ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4656}
4657
4658static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
4659 ext4_lblk_t len, loff_t new_size,
4660 int flags, int mode)
4661{
4662 struct inode *inode = file_inode(file);
4663 handle_t *handle;
4664 int ret = 0;
4665 int ret2 = 0;
4666 int retries = 0;
4667 int depth = 0;
4668 struct ext4_map_blocks map;
4669 unsigned int credits;
4670 loff_t epos;
4671
4672 BUG_ON(!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS));
4673 map.m_lblk = offset;
4674 map.m_len = len;
4675 /*
4676 * Don't normalize the request if it can fit in one extent so
4677 * that it doesn't get unnecessarily split into multiple
4678 * extents.
4679 */
4680 if (len <= EXT_UNWRITTEN_MAX_LEN)
4681 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4682
4683 /*
4684 * credits to insert 1 extent into extent tree
4685 */
4686 credits = ext4_chunk_trans_blocks(inode, len);
4687 depth = ext_depth(inode);
4688
4689retry:
4690 while (ret >= 0 && len) {
4691 /*
4692 * Recalculate credits when extent tree depth changes.
4693 */
4694 if (depth != ext_depth(inode)) {
4695 credits = ext4_chunk_trans_blocks(inode, len);
4696 depth = ext_depth(inode);
4697 }
4698
4699 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4700 credits);
4701 if (IS_ERR(handle)) {
4702 ret = PTR_ERR(handle);
4703 break;
4704 }
4705 ret = ext4_map_blocks(handle, inode, &map, flags);
4706 if (ret <= 0) {
4707 ext4_debug("inode #%lu: block %u: len %u: "
4708 "ext4_ext_map_blocks returned %d",
4709 inode->i_ino, map.m_lblk,
4710 map.m_len, ret);
4711 ext4_mark_inode_dirty(handle, inode);
4712 ret2 = ext4_journal_stop(handle);
4713 break;
4714 }
4715 map.m_lblk += ret;
4716 map.m_len = len = len - ret;
4717 epos = (loff_t)map.m_lblk << inode->i_blkbits;
4718 inode->i_ctime = current_time(inode);
4719 if (new_size) {
4720 if (epos > new_size)
4721 epos = new_size;
4722 if (ext4_update_inode_size(inode, epos) & 0x1)
4723 inode->i_mtime = inode->i_ctime;
4724 } else {
4725 if (epos > inode->i_size)
4726 ext4_set_inode_flag(inode,
4727 EXT4_INODE_EOFBLOCKS);
4728 }
4729 ext4_mark_inode_dirty(handle, inode);
4730 ret2 = ext4_journal_stop(handle);
4731 if (ret2)
4732 break;
4733 }
4734 if (ret == -ENOSPC &&
4735 ext4_should_retry_alloc(inode->i_sb, &retries)) {
4736 ret = 0;
4737 goto retry;
4738 }
4739
4740 return ret > 0 ? ret2 : ret;
4741}
4742
4743static long ext4_zero_range(struct file *file, loff_t offset,
4744 loff_t len, int mode)
4745{
4746 struct inode *inode = file_inode(file);
4747 handle_t *handle = NULL;
4748 unsigned int max_blocks;
4749 loff_t new_size = 0;
4750 int ret = 0;
4751 int flags;
4752 int credits;
4753 int partial_begin, partial_end;
4754 loff_t start, end;
4755 ext4_lblk_t lblk;
4756 unsigned int blkbits = inode->i_blkbits;
4757
4758 trace_ext4_zero_range(inode, offset, len, mode);
4759
4760 if (!S_ISREG(inode->i_mode))
4761 return -EINVAL;
4762
4763 /* Call ext4_force_commit to flush all data in case of data=journal. */
4764 if (ext4_should_journal_data(inode)) {
4765 ret = ext4_force_commit(inode->i_sb);
4766 if (ret)
4767 return ret;
4768 }
4769
4770 /*
4771 * Round up offset. This is not fallocate, we neet to zero out
4772 * blocks, so convert interior block aligned part of the range to
4773 * unwritten and possibly manually zero out unaligned parts of the
4774 * range.
4775 */
4776 start = round_up(offset, 1 << blkbits);
4777 end = round_down((offset + len), 1 << blkbits);
4778
4779 if (start < offset || end > offset + len)
4780 return -EINVAL;
4781 partial_begin = offset & ((1 << blkbits) - 1);
4782 partial_end = (offset + len) & ((1 << blkbits) - 1);
4783
4784 lblk = start >> blkbits;
4785 max_blocks = (end >> blkbits);
4786 if (max_blocks < lblk)
4787 max_blocks = 0;
4788 else
4789 max_blocks -= lblk;
4790
4791 inode_lock(inode);
4792
4793 /*
4794 * Indirect files do not support unwritten extnets
4795 */
4796 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4797 ret = -EOPNOTSUPP;
4798 goto out_mutex;
4799 }
4800
4801 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4802 offset + len > i_size_read(inode)) {
4803 new_size = offset + len;
4804 ret = inode_newsize_ok(inode, new_size);
4805 if (ret)
4806 goto out_mutex;
4807 }
4808
4809 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4810 if (mode & FALLOC_FL_KEEP_SIZE)
4811 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4812
4813 /* Wait all existing dio workers, newcomers will block on i_mutex */
4814 ext4_inode_block_unlocked_dio(inode);
4815 inode_dio_wait(inode);
4816
4817 /* Preallocate the range including the unaligned edges */
4818 if (partial_begin || partial_end) {
4819 ret = ext4_alloc_file_blocks(file,
4820 round_down(offset, 1 << blkbits) >> blkbits,
4821 (round_up((offset + len), 1 << blkbits) -
4822 round_down(offset, 1 << blkbits)) >> blkbits,
4823 new_size, flags, mode);
4824 if (ret)
4825 goto out_dio;
4826
4827 }
4828
4829 /* Zero range excluding the unaligned edges */
4830 if (max_blocks > 0) {
4831 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
4832 EXT4_EX_NOCACHE);
4833
4834 /*
4835 * Prevent page faults from reinstantiating pages we have
4836 * released from page cache.
4837 */
4838 down_write(&EXT4_I(inode)->i_mmap_sem);
4839 ret = ext4_update_disksize_before_punch(inode, offset, len);
4840 if (ret) {
4841 up_write(&EXT4_I(inode)->i_mmap_sem);
4842 goto out_dio;
4843 }
4844 /* Now release the pages and zero block aligned part of pages */
4845 truncate_pagecache_range(inode, start, end - 1);
4846 inode->i_mtime = inode->i_ctime = current_time(inode);
4847
4848 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4849 flags, mode);
4850 up_write(&EXT4_I(inode)->i_mmap_sem);
4851 if (ret)
4852 goto out_dio;
4853 }
4854 if (!partial_begin && !partial_end)
4855 goto out_dio;
4856
4857 /*
4858 * In worst case we have to writeout two nonadjacent unwritten
4859 * blocks and update the inode
4860 */
4861 credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
4862 if (ext4_should_journal_data(inode))
4863 credits += 2;
4864 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
4865 if (IS_ERR(handle)) {
4866 ret = PTR_ERR(handle);
4867 ext4_std_error(inode->i_sb, ret);
4868 goto out_dio;
4869 }
4870
4871 inode->i_mtime = inode->i_ctime = current_time(inode);
4872 if (new_size) {
4873 ext4_update_inode_size(inode, new_size);
4874 } else {
4875 /*
4876 * Mark that we allocate beyond EOF so the subsequent truncate
4877 * can proceed even if the new size is the same as i_size.
4878 */
4879 if ((offset + len) > i_size_read(inode))
4880 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4881 }
4882 ext4_mark_inode_dirty(handle, inode);
4883
4884 /* Zero out partial block at the edges of the range */
4885 ret = ext4_zero_partial_blocks(handle, inode, offset, len);
4886
4887 if (file->f_flags & O_SYNC)
4888 ext4_handle_sync(handle);
4889
4890 ext4_journal_stop(handle);
4891out_dio:
4892 ext4_inode_resume_unlocked_dio(inode);
4893out_mutex:
4894 inode_unlock(inode);
4895 return ret;
4896}
4897
4898/*
4899 * preallocate space for a file. This implements ext4's fallocate file
4900 * operation, which gets called from sys_fallocate system call.
4901 * For block-mapped files, posix_fallocate should fall back to the method
4902 * of writing zeroes to the required new blocks (the same behavior which is
4903 * expected for file systems which do not support fallocate() system call).
4904 */
4905long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4906{
4907 struct inode *inode = file_inode(file);
4908 loff_t new_size = 0;
4909 unsigned int max_blocks;
4910 int ret = 0;
4911 int flags;
4912 ext4_lblk_t lblk;
4913 unsigned int blkbits = inode->i_blkbits;
4914
4915 /*
4916 * Encrypted inodes can't handle collapse range or insert
4917 * range since we would need to re-encrypt blocks with a
4918 * different IV or XTS tweak (which are based on the logical
4919 * block number).
4920 *
4921 * XXX It's not clear why zero range isn't working, but we'll
4922 * leave it disabled for encrypted inodes for now. This is a
4923 * bug we should fix....
4924 */
4925 if (ext4_encrypted_inode(inode) &&
4926 (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE |
4927 FALLOC_FL_ZERO_RANGE)))
4928 return -EOPNOTSUPP;
4929
4930 /* Return error if mode is not supported */
4931 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
4932 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
4933 FALLOC_FL_INSERT_RANGE))
4934 return -EOPNOTSUPP;
4935
4936 if (mode & FALLOC_FL_PUNCH_HOLE)
4937 return ext4_punch_hole(inode, offset, len);
4938
4939 ret = ext4_convert_inline_data(inode);
4940 if (ret)
4941 return ret;
4942
4943 if (mode & FALLOC_FL_COLLAPSE_RANGE)
4944 return ext4_collapse_range(inode, offset, len);
4945
4946 if (mode & FALLOC_FL_INSERT_RANGE)
4947 return ext4_insert_range(inode, offset, len);
4948
4949 if (mode & FALLOC_FL_ZERO_RANGE)
4950 return ext4_zero_range(file, offset, len, mode);
4951
4952 trace_ext4_fallocate_enter(inode, offset, len, mode);
4953 lblk = offset >> blkbits;
4954
4955 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
4956 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4957 if (mode & FALLOC_FL_KEEP_SIZE)
4958 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4959
4960 inode_lock(inode);
4961
4962 /*
4963 * We only support preallocation for extent-based files only
4964 */
4965 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4966 ret = -EOPNOTSUPP;
4967 goto out;
4968 }
4969
4970 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4971 offset + len > i_size_read(inode)) {
4972 new_size = offset + len;
4973 ret = inode_newsize_ok(inode, new_size);
4974 if (ret)
4975 goto out;
4976 }
4977
4978 /* Wait all existing dio workers, newcomers will block on i_mutex */
4979 ext4_inode_block_unlocked_dio(inode);
4980 inode_dio_wait(inode);
4981
4982 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4983 flags, mode);
4984 ext4_inode_resume_unlocked_dio(inode);
4985 if (ret)
4986 goto out;
4987
4988 if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
4989 ret = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal,
4990 EXT4_I(inode)->i_sync_tid);
4991 }
4992out:
4993 inode_unlock(inode);
4994 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
4995 return ret;
4996}
4997
4998/*
4999 * This function convert a range of blocks to written extents
5000 * The caller of this function will pass the start offset and the size.
5001 * all unwritten extents within this range will be converted to
5002 * written extents.
5003 *
5004 * This function is called from the direct IO end io call back
5005 * function, to convert the fallocated extents after IO is completed.
5006 * Returns 0 on success.
5007 */
5008int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
5009 loff_t offset, ssize_t len)
5010{
5011 unsigned int max_blocks;
5012 int ret = 0;
5013 int ret2 = 0;
5014 struct ext4_map_blocks map;
5015 unsigned int credits, blkbits = inode->i_blkbits;
5016
5017 map.m_lblk = offset >> blkbits;
5018 max_blocks = EXT4_MAX_BLOCKS(len, offset, blkbits);
5019
5020 /*
5021 * This is somewhat ugly but the idea is clear: When transaction is
5022 * reserved, everything goes into it. Otherwise we rather start several
5023 * smaller transactions for conversion of each extent separately.
5024 */
5025 if (handle) {
5026 handle = ext4_journal_start_reserved(handle,
5027 EXT4_HT_EXT_CONVERT);
5028 if (IS_ERR(handle))
5029 return PTR_ERR(handle);
5030 credits = 0;
5031 } else {
5032 /*
5033 * credits to insert 1 extent into extent tree
5034 */
5035 credits = ext4_chunk_trans_blocks(inode, max_blocks);
5036 }
5037 while (ret >= 0 && ret < max_blocks) {
5038 map.m_lblk += ret;
5039 map.m_len = (max_blocks -= ret);
5040 if (credits) {
5041 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
5042 credits);
5043 if (IS_ERR(handle)) {
5044 ret = PTR_ERR(handle);
5045 break;
5046 }
5047 }
5048 ret = ext4_map_blocks(handle, inode, &map,
5049 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
5050 if (ret <= 0)
5051 ext4_warning(inode->i_sb,
5052 "inode #%lu: block %u: len %u: "
5053 "ext4_ext_map_blocks returned %d",
5054 inode->i_ino, map.m_lblk,
5055 map.m_len, ret);
5056 ext4_mark_inode_dirty(handle, inode);
5057 if (credits)
5058 ret2 = ext4_journal_stop(handle);
5059 if (ret <= 0 || ret2)
5060 break;
5061 }
5062 if (!credits)
5063 ret2 = ext4_journal_stop(handle);
5064 return ret > 0 ? ret2 : ret;
5065}
5066
5067/*
5068 * If newes is not existing extent (newes->ec_pblk equals zero) find
5069 * delayed extent at start of newes and update newes accordingly and
5070 * return start of the next delayed extent.
5071 *
5072 * If newes is existing extent (newes->ec_pblk is not equal zero)
5073 * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
5074 * extent found. Leave newes unmodified.
5075 */
5076static int ext4_find_delayed_extent(struct inode *inode,
5077 struct extent_status *newes)
5078{
5079 struct extent_status es;
5080 ext4_lblk_t block, next_del;
5081
5082 if (newes->es_pblk == 0) {
5083 ext4_es_find_delayed_extent_range(inode, newes->es_lblk,
5084 newes->es_lblk + newes->es_len - 1, &es);
5085
5086 /*
5087 * No extent in extent-tree contains block @newes->es_pblk,
5088 * then the block may stay in 1)a hole or 2)delayed-extent.
5089 */
5090 if (es.es_len == 0)
5091 /* A hole found. */
5092 return 0;
5093
5094 if (es.es_lblk > newes->es_lblk) {
5095 /* A hole found. */
5096 newes->es_len = min(es.es_lblk - newes->es_lblk,
5097 newes->es_len);
5098 return 0;
5099 }
5100
5101 newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
5102 }
5103
5104 block = newes->es_lblk + newes->es_len;
5105 ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es);
5106 if (es.es_len == 0)
5107 next_del = EXT_MAX_BLOCKS;
5108 else
5109 next_del = es.es_lblk;
5110
5111 return next_del;
5112}
5113/* fiemap flags we can handle specified here */
5114#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
5115
5116static int ext4_xattr_fiemap(struct inode *inode,
5117 struct fiemap_extent_info *fieinfo)
5118{
5119 __u64 physical = 0;
5120 __u64 length;
5121 __u32 flags = FIEMAP_EXTENT_LAST;
5122 int blockbits = inode->i_sb->s_blocksize_bits;
5123 int error = 0;
5124
5125 /* in-inode? */
5126 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
5127 struct ext4_iloc iloc;
5128 int offset; /* offset of xattr in inode */
5129
5130 error = ext4_get_inode_loc(inode, &iloc);
5131 if (error)
5132 return error;
5133 physical = (__u64)iloc.bh->b_blocknr << blockbits;
5134 offset = EXT4_GOOD_OLD_INODE_SIZE +
5135 EXT4_I(inode)->i_extra_isize;
5136 physical += offset;
5137 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
5138 flags |= FIEMAP_EXTENT_DATA_INLINE;
5139 brelse(iloc.bh);
5140 } else { /* external block */
5141 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
5142 length = inode->i_sb->s_blocksize;
5143 }
5144
5145 if (physical)
5146 error = fiemap_fill_next_extent(fieinfo, 0, physical,
5147 length, flags);
5148 return (error < 0 ? error : 0);
5149}
5150
5151int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
5152 __u64 start, __u64 len)
5153{
5154 ext4_lblk_t start_blk;
5155 int error = 0;
5156
5157 if (ext4_has_inline_data(inode)) {
5158 int has_inline = 1;
5159
5160 error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
5161 start, len);
5162
5163 if (has_inline)
5164 return error;
5165 }
5166
5167 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
5168 error = ext4_ext_precache(inode);
5169 if (error)
5170 return error;
5171 }
5172
5173 /* fallback to generic here if not in extents fmt */
5174 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
5175 return generic_block_fiemap(inode, fieinfo, start, len,
5176 ext4_get_block);
5177
5178 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
5179 return -EBADR;
5180
5181 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
5182 error = ext4_xattr_fiemap(inode, fieinfo);
5183 } else {
5184 ext4_lblk_t len_blks;
5185 __u64 last_blk;
5186
5187 start_blk = start >> inode->i_sb->s_blocksize_bits;
5188 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
5189 if (last_blk >= EXT_MAX_BLOCKS)
5190 last_blk = EXT_MAX_BLOCKS-1;
5191 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
5192
5193 /*
5194 * Walk the extent tree gathering extent information
5195 * and pushing extents back to the user.
5196 */
5197 error = ext4_fill_fiemap_extents(inode, start_blk,
5198 len_blks, fieinfo);
5199 }
5200 return error;
5201}
5202
5203/*
5204 * ext4_access_path:
5205 * Function to access the path buffer for marking it dirty.
5206 * It also checks if there are sufficient credits left in the journal handle
5207 * to update path.
5208 */
5209static int
5210ext4_access_path(handle_t *handle, struct inode *inode,
5211 struct ext4_ext_path *path)
5212{
5213 int credits, err;
5214
5215 if (!ext4_handle_valid(handle))
5216 return 0;
5217
5218 /*
5219 * Check if need to extend journal credits
5220 * 3 for leaf, sb, and inode plus 2 (bmap and group
5221 * descriptor) for each block group; assume two block
5222 * groups
5223 */
5224 if (handle->h_buffer_credits < 7) {
5225 credits = ext4_writepage_trans_blocks(inode);
5226 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
5227 /* EAGAIN is success */
5228 if (err && err != -EAGAIN)
5229 return err;
5230 }
5231
5232 err = ext4_ext_get_access(handle, inode, path);
5233 return err;
5234}
5235
5236/*
5237 * ext4_ext_shift_path_extents:
5238 * Shift the extents of a path structure lying between path[depth].p_ext
5239 * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
5240 * if it is right shift or left shift operation.
5241 */
5242static int
5243ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
5244 struct inode *inode, handle_t *handle,
5245 enum SHIFT_DIRECTION SHIFT)
5246{
5247 int depth, err = 0;
5248 struct ext4_extent *ex_start, *ex_last;
5249 bool update = 0;
5250 depth = path->p_depth;
5251
5252 while (depth >= 0) {
5253 if (depth == path->p_depth) {
5254 ex_start = path[depth].p_ext;
5255 if (!ex_start)
5256 return -EFSCORRUPTED;
5257
5258 ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
5259
5260 err = ext4_access_path(handle, inode, path + depth);
5261 if (err)
5262 goto out;
5263
5264 if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr))
5265 update = 1;
5266
5267 while (ex_start <= ex_last) {
5268 if (SHIFT == SHIFT_LEFT) {
5269 le32_add_cpu(&ex_start->ee_block,
5270 -shift);
5271 /* Try to merge to the left. */
5272 if ((ex_start >
5273 EXT_FIRST_EXTENT(path[depth].p_hdr))
5274 &&
5275 ext4_ext_try_to_merge_right(inode,
5276 path, ex_start - 1))
5277 ex_last--;
5278 else
5279 ex_start++;
5280 } else {
5281 le32_add_cpu(&ex_last->ee_block, shift);
5282 ext4_ext_try_to_merge_right(inode, path,
5283 ex_last);
5284 ex_last--;
5285 }
5286 }
5287 err = ext4_ext_dirty(handle, inode, path + depth);
5288 if (err)
5289 goto out;
5290
5291 if (--depth < 0 || !update)
5292 break;
5293 }
5294
5295 /* Update index too */
5296 err = ext4_access_path(handle, inode, path + depth);
5297 if (err)
5298 goto out;
5299
5300 if (SHIFT == SHIFT_LEFT)
5301 le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
5302 else
5303 le32_add_cpu(&path[depth].p_idx->ei_block, shift);
5304 err = ext4_ext_dirty(handle, inode, path + depth);
5305 if (err)
5306 goto out;
5307
5308 /* we are done if current index is not a starting index */
5309 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
5310 break;
5311
5312 depth--;
5313 }
5314
5315out:
5316 return err;
5317}
5318
5319/*
5320 * ext4_ext_shift_extents:
5321 * All the extents which lies in the range from @start to the last allocated
5322 * block for the @inode are shifted either towards left or right (depending
5323 * upon @SHIFT) by @shift blocks.
5324 * On success, 0 is returned, error otherwise.
5325 */
5326static int
5327ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
5328 ext4_lblk_t start, ext4_lblk_t shift,
5329 enum SHIFT_DIRECTION SHIFT)
5330{
5331 struct ext4_ext_path *path;
5332 int ret = 0, depth;
5333 struct ext4_extent *extent;
5334 ext4_lblk_t stop, *iterator, ex_start, ex_end;
5335
5336 /* Let path point to the last extent */
5337 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL,
5338 EXT4_EX_NOCACHE);
5339 if (IS_ERR(path))
5340 return PTR_ERR(path);
5341
5342 depth = path->p_depth;
5343 extent = path[depth].p_ext;
5344 if (!extent)
5345 goto out;
5346
5347 stop = le32_to_cpu(extent->ee_block);
5348
5349 /*
5350 * In case of left shift, Don't start shifting extents until we make
5351 * sure the hole is big enough to accommodate the shift.
5352 */
5353 if (SHIFT == SHIFT_LEFT) {
5354 path = ext4_find_extent(inode, start - 1, &path,
5355 EXT4_EX_NOCACHE);
5356 if (IS_ERR(path))
5357 return PTR_ERR(path);
5358 depth = path->p_depth;
5359 extent = path[depth].p_ext;
5360 if (extent) {
5361 ex_start = le32_to_cpu(extent->ee_block);
5362 ex_end = le32_to_cpu(extent->ee_block) +
5363 ext4_ext_get_actual_len(extent);
5364 } else {
5365 ex_start = 0;
5366 ex_end = 0;
5367 }
5368
5369 if ((start == ex_start && shift > ex_start) ||
5370 (shift > start - ex_end)) {
5371 ext4_ext_drop_refs(path);
5372 kfree(path);
5373 return -EINVAL;
5374 }
5375 }
5376
5377 /*
5378 * In case of left shift, iterator points to start and it is increased
5379 * till we reach stop. In case of right shift, iterator points to stop
5380 * and it is decreased till we reach start.
5381 */
5382 if (SHIFT == SHIFT_LEFT)
5383 iterator = &start;
5384 else
5385 iterator = &stop;
5386
5387 /*
5388 * Its safe to start updating extents. Start and stop are unsigned, so
5389 * in case of right shift if extent with 0 block is reached, iterator
5390 * becomes NULL to indicate the end of the loop.
5391 */
5392 while (iterator && start <= stop) {
5393 path = ext4_find_extent(inode, *iterator, &path,
5394 EXT4_EX_NOCACHE);
5395 if (IS_ERR(path))
5396 return PTR_ERR(path);
5397 depth = path->p_depth;
5398 extent = path[depth].p_ext;
5399 if (!extent) {
5400 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
5401 (unsigned long) *iterator);
5402 return -EFSCORRUPTED;
5403 }
5404 if (SHIFT == SHIFT_LEFT && *iterator >
5405 le32_to_cpu(extent->ee_block)) {
5406 /* Hole, move to the next extent */
5407 if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
5408 path[depth].p_ext++;
5409 } else {
5410 *iterator = ext4_ext_next_allocated_block(path);
5411 continue;
5412 }
5413 }
5414
5415 if (SHIFT == SHIFT_LEFT) {
5416 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5417 *iterator = le32_to_cpu(extent->ee_block) +
5418 ext4_ext_get_actual_len(extent);
5419 } else {
5420 extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
5421 if (le32_to_cpu(extent->ee_block) > 0)
5422 *iterator = le32_to_cpu(extent->ee_block) - 1;
5423 else
5424 /* Beginning is reached, end of the loop */
5425 iterator = NULL;
5426 /* Update path extent in case we need to stop */
5427 while (le32_to_cpu(extent->ee_block) < start)
5428 extent++;
5429 path[depth].p_ext = extent;
5430 }
5431 ret = ext4_ext_shift_path_extents(path, shift, inode,
5432 handle, SHIFT);
5433 if (ret)
5434 break;
5435 }
5436out:
5437 ext4_ext_drop_refs(path);
5438 kfree(path);
5439 return ret;
5440}
5441
5442/*
5443 * ext4_collapse_range:
5444 * This implements the fallocate's collapse range functionality for ext4
5445 * Returns: 0 and non-zero on error.
5446 */
5447int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
5448{
5449 struct super_block *sb = inode->i_sb;
5450 ext4_lblk_t punch_start, punch_stop;
5451 handle_t *handle;
5452 unsigned int credits;
5453 loff_t new_size, ioffset;
5454 int ret;
5455
5456 /*
5457 * We need to test this early because xfstests assumes that a
5458 * collapse range of (0, 1) will return EOPNOTSUPP if the file
5459 * system does not support collapse range.
5460 */
5461 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5462 return -EOPNOTSUPP;
5463
5464 /* Collapse range works only on fs block size aligned offsets. */
5465 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
5466 len & (EXT4_CLUSTER_SIZE(sb) - 1))
5467 return -EINVAL;
5468
5469 if (!S_ISREG(inode->i_mode))
5470 return -EINVAL;
5471
5472 trace_ext4_collapse_range(inode, offset, len);
5473
5474 punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5475 punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb);
5476
5477 /* Call ext4_force_commit to flush all data in case of data=journal. */
5478 if (ext4_should_journal_data(inode)) {
5479 ret = ext4_force_commit(inode->i_sb);
5480 if (ret)
5481 return ret;
5482 }
5483
5484 inode_lock(inode);
5485 /*
5486 * There is no need to overlap collapse range with EOF, in which case
5487 * it is effectively a truncate operation
5488 */
5489 if (offset + len >= i_size_read(inode)) {
5490 ret = -EINVAL;
5491 goto out_mutex;
5492 }
5493
5494 /* Currently just for extent based files */
5495 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5496 ret = -EOPNOTSUPP;
5497 goto out_mutex;
5498 }
5499
5500 /* Wait for existing dio to complete */
5501 ext4_inode_block_unlocked_dio(inode);
5502 inode_dio_wait(inode);
5503
5504 /*
5505 * Prevent page faults from reinstantiating pages we have released from
5506 * page cache.
5507 */
5508 down_write(&EXT4_I(inode)->i_mmap_sem);
5509 /*
5510 * Need to round down offset to be aligned with page size boundary
5511 * for page size > block size.
5512 */
5513 ioffset = round_down(offset, PAGE_SIZE);
5514 /*
5515 * Write tail of the last page before removed range since it will get
5516 * removed from the page cache below.
5517 */
5518 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset, offset);
5519 if (ret)
5520 goto out_mmap;
5521 /*
5522 * Write data that will be shifted to preserve them when discarding
5523 * page cache below. We are also protected from pages becoming dirty
5524 * by i_mmap_sem.
5525 */
5526 ret = filemap_write_and_wait_range(inode->i_mapping, offset + len,
5527 LLONG_MAX);
5528 if (ret)
5529 goto out_mmap;
5530 truncate_pagecache(inode, ioffset);
5531
5532 credits = ext4_writepage_trans_blocks(inode);
5533 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5534 if (IS_ERR(handle)) {
5535 ret = PTR_ERR(handle);
5536 goto out_mmap;
5537 }
5538
5539 down_write(&EXT4_I(inode)->i_data_sem);
5540 ext4_discard_preallocations(inode);
5541
5542 ret = ext4_es_remove_extent(inode, punch_start,
5543 EXT_MAX_BLOCKS - punch_start);
5544 if (ret) {
5545 up_write(&EXT4_I(inode)->i_data_sem);
5546 goto out_stop;
5547 }
5548
5549 ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
5550 if (ret) {
5551 up_write(&EXT4_I(inode)->i_data_sem);
5552 goto out_stop;
5553 }
5554 ext4_discard_preallocations(inode);
5555
5556 ret = ext4_ext_shift_extents(inode, handle, punch_stop,
5557 punch_stop - punch_start, SHIFT_LEFT);
5558 if (ret) {
5559 up_write(&EXT4_I(inode)->i_data_sem);
5560 goto out_stop;
5561 }
5562
5563 new_size = i_size_read(inode) - len;
5564 i_size_write(inode, new_size);
5565 EXT4_I(inode)->i_disksize = new_size;
5566
5567 up_write(&EXT4_I(inode)->i_data_sem);
5568 if (IS_SYNC(inode))
5569 ext4_handle_sync(handle);
5570 inode->i_mtime = inode->i_ctime = current_time(inode);
5571 ext4_mark_inode_dirty(handle, inode);
5572
5573out_stop:
5574 ext4_journal_stop(handle);
5575out_mmap:
5576 up_write(&EXT4_I(inode)->i_mmap_sem);
5577 ext4_inode_resume_unlocked_dio(inode);
5578out_mutex:
5579 inode_unlock(inode);
5580 return ret;
5581}
5582
5583/*
5584 * ext4_insert_range:
5585 * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
5586 * The data blocks starting from @offset to the EOF are shifted by @len
5587 * towards right to create a hole in the @inode. Inode size is increased
5588 * by len bytes.
5589 * Returns 0 on success, error otherwise.
5590 */
5591int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
5592{
5593 struct super_block *sb = inode->i_sb;
5594 handle_t *handle;
5595 struct ext4_ext_path *path;
5596 struct ext4_extent *extent;
5597 ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
5598 unsigned int credits, ee_len;
5599 int ret = 0, depth, split_flag = 0;
5600 loff_t ioffset;
5601
5602 /*
5603 * We need to test this early because xfstests assumes that an
5604 * insert range of (0, 1) will return EOPNOTSUPP if the file
5605 * system does not support insert range.
5606 */
5607 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5608 return -EOPNOTSUPP;
5609
5610 /* Insert range works only on fs block size aligned offsets. */
5611 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
5612 len & (EXT4_CLUSTER_SIZE(sb) - 1))
5613 return -EINVAL;
5614
5615 if (!S_ISREG(inode->i_mode))
5616 return -EOPNOTSUPP;
5617
5618 trace_ext4_insert_range(inode, offset, len);
5619
5620 offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5621 len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
5622
5623 /* Call ext4_force_commit to flush all data in case of data=journal */
5624 if (ext4_should_journal_data(inode)) {
5625 ret = ext4_force_commit(inode->i_sb);
5626 if (ret)
5627 return ret;
5628 }
5629
5630 inode_lock(inode);
5631 /* Currently just for extent based files */
5632 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5633 ret = -EOPNOTSUPP;
5634 goto out_mutex;
5635 }
5636
5637 /* Check for wrap through zero */
5638 if (inode->i_size + len > inode->i_sb->s_maxbytes) {
5639 ret = -EFBIG;
5640 goto out_mutex;
5641 }
5642
5643 /* Offset should be less than i_size */
5644 if (offset >= i_size_read(inode)) {
5645 ret = -EINVAL;
5646 goto out_mutex;
5647 }
5648
5649 /* Wait for existing dio to complete */
5650 ext4_inode_block_unlocked_dio(inode);
5651 inode_dio_wait(inode);
5652
5653 /*
5654 * Prevent page faults from reinstantiating pages we have released from
5655 * page cache.
5656 */
5657 down_write(&EXT4_I(inode)->i_mmap_sem);
5658 /*
5659 * Need to round down to align start offset to page size boundary
5660 * for page size > block size.
5661 */
5662 ioffset = round_down(offset, PAGE_SIZE);
5663 /* Write out all dirty pages */
5664 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5665 LLONG_MAX);
5666 if (ret)
5667 goto out_mmap;
5668 truncate_pagecache(inode, ioffset);
5669
5670 credits = ext4_writepage_trans_blocks(inode);
5671 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5672 if (IS_ERR(handle)) {
5673 ret = PTR_ERR(handle);
5674 goto out_mmap;
5675 }
5676
5677 /* Expand file to avoid data loss if there is error while shifting */
5678 inode->i_size += len;
5679 EXT4_I(inode)->i_disksize += len;
5680 inode->i_mtime = inode->i_ctime = current_time(inode);
5681 ret = ext4_mark_inode_dirty(handle, inode);
5682 if (ret)
5683 goto out_stop;
5684
5685 down_write(&EXT4_I(inode)->i_data_sem);
5686 ext4_discard_preallocations(inode);
5687
5688 path = ext4_find_extent(inode, offset_lblk, NULL, 0);
5689 if (IS_ERR(path)) {
5690 up_write(&EXT4_I(inode)->i_data_sem);
5691 goto out_stop;
5692 }
5693
5694 depth = ext_depth(inode);
5695 extent = path[depth].p_ext;
5696 if (extent) {
5697 ee_start_lblk = le32_to_cpu(extent->ee_block);
5698 ee_len = ext4_ext_get_actual_len(extent);
5699
5700 /*
5701 * If offset_lblk is not the starting block of extent, split
5702 * the extent @offset_lblk
5703 */
5704 if ((offset_lblk > ee_start_lblk) &&
5705 (offset_lblk < (ee_start_lblk + ee_len))) {
5706 if (ext4_ext_is_unwritten(extent))
5707 split_flag = EXT4_EXT_MARK_UNWRIT1 |
5708 EXT4_EXT_MARK_UNWRIT2;
5709 ret = ext4_split_extent_at(handle, inode, &path,
5710 offset_lblk, split_flag,
5711 EXT4_EX_NOCACHE |
5712 EXT4_GET_BLOCKS_PRE_IO |
5713 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5714 }
5715
5716 ext4_ext_drop_refs(path);
5717 kfree(path);
5718 if (ret < 0) {
5719 up_write(&EXT4_I(inode)->i_data_sem);
5720 goto out_stop;
5721 }
5722 } else {
5723 ext4_ext_drop_refs(path);
5724 kfree(path);
5725 }
5726
5727 ret = ext4_es_remove_extent(inode, offset_lblk,
5728 EXT_MAX_BLOCKS - offset_lblk);
5729 if (ret) {
5730 up_write(&EXT4_I(inode)->i_data_sem);
5731 goto out_stop;
5732 }
5733
5734 /*
5735 * if offset_lblk lies in a hole which is at start of file, use
5736 * ee_start_lblk to shift extents
5737 */
5738 ret = ext4_ext_shift_extents(inode, handle,
5739 ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk,
5740 len_lblk, SHIFT_RIGHT);
5741
5742 up_write(&EXT4_I(inode)->i_data_sem);
5743 if (IS_SYNC(inode))
5744 ext4_handle_sync(handle);
5745
5746out_stop:
5747 ext4_journal_stop(handle);
5748out_mmap:
5749 up_write(&EXT4_I(inode)->i_mmap_sem);
5750 ext4_inode_resume_unlocked_dio(inode);
5751out_mutex:
5752 inode_unlock(inode);
5753 return ret;
5754}
5755
5756/**
5757 * ext4_swap_extents - Swap extents between two inodes
5758 *
5759 * @inode1: First inode
5760 * @inode2: Second inode
5761 * @lblk1: Start block for first inode
5762 * @lblk2: Start block for second inode
5763 * @count: Number of blocks to swap
5764 * @mark_unwritten: Mark second inode's extents as unwritten after swap
5765 * @erp: Pointer to save error value
5766 *
5767 * This helper routine does exactly what is promise "swap extents". All other
5768 * stuff such as page-cache locking consistency, bh mapping consistency or
5769 * extent's data copying must be performed by caller.
5770 * Locking:
5771 * i_mutex is held for both inodes
5772 * i_data_sem is locked for write for both inodes
5773 * Assumptions:
5774 * All pages from requested range are locked for both inodes
5775 */
5776int
5777ext4_swap_extents(handle_t *handle, struct inode *inode1,
5778 struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
5779 ext4_lblk_t count, int unwritten, int *erp)
5780{
5781 struct ext4_ext_path *path1 = NULL;
5782 struct ext4_ext_path *path2 = NULL;
5783 int replaced_count = 0;
5784
5785 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
5786 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
5787 BUG_ON(!inode_is_locked(inode1));
5788 BUG_ON(!inode_is_locked(inode2));
5789
5790 *erp = ext4_es_remove_extent(inode1, lblk1, count);
5791 if (unlikely(*erp))
5792 return 0;
5793 *erp = ext4_es_remove_extent(inode2, lblk2, count);
5794 if (unlikely(*erp))
5795 return 0;
5796
5797 while (count) {
5798 struct ext4_extent *ex1, *ex2, tmp_ex;
5799 ext4_lblk_t e1_blk, e2_blk;
5800 int e1_len, e2_len, len;
5801 int split = 0;
5802
5803 path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE);
5804 if (IS_ERR(path1)) {
5805 *erp = PTR_ERR(path1);
5806 path1 = NULL;
5807 finish:
5808 count = 0;
5809 goto repeat;
5810 }
5811 path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE);
5812 if (IS_ERR(path2)) {
5813 *erp = PTR_ERR(path2);
5814 path2 = NULL;
5815 goto finish;
5816 }
5817 ex1 = path1[path1->p_depth].p_ext;
5818 ex2 = path2[path2->p_depth].p_ext;
5819 /* Do we have somthing to swap ? */
5820 if (unlikely(!ex2 || !ex1))
5821 goto finish;
5822
5823 e1_blk = le32_to_cpu(ex1->ee_block);
5824 e2_blk = le32_to_cpu(ex2->ee_block);
5825 e1_len = ext4_ext_get_actual_len(ex1);
5826 e2_len = ext4_ext_get_actual_len(ex2);
5827
5828 /* Hole handling */
5829 if (!in_range(lblk1, e1_blk, e1_len) ||
5830 !in_range(lblk2, e2_blk, e2_len)) {
5831 ext4_lblk_t next1, next2;
5832
5833 /* if hole after extent, then go to next extent */
5834 next1 = ext4_ext_next_allocated_block(path1);
5835 next2 = ext4_ext_next_allocated_block(path2);
5836 /* If hole before extent, then shift to that extent */
5837 if (e1_blk > lblk1)
5838 next1 = e1_blk;
5839 if (e2_blk > lblk2)
5840 next2 = e1_blk;
5841 /* Do we have something to swap */
5842 if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
5843 goto finish;
5844 /* Move to the rightest boundary */
5845 len = next1 - lblk1;
5846 if (len < next2 - lblk2)
5847 len = next2 - lblk2;
5848 if (len > count)
5849 len = count;
5850 lblk1 += len;
5851 lblk2 += len;
5852 count -= len;
5853 goto repeat;
5854 }
5855
5856 /* Prepare left boundary */
5857 if (e1_blk < lblk1) {
5858 split = 1;
5859 *erp = ext4_force_split_extent_at(handle, inode1,
5860 &path1, lblk1, 0);
5861 if (unlikely(*erp))
5862 goto finish;
5863 }
5864 if (e2_blk < lblk2) {
5865 split = 1;
5866 *erp = ext4_force_split_extent_at(handle, inode2,
5867 &path2, lblk2, 0);
5868 if (unlikely(*erp))
5869 goto finish;
5870 }
5871 /* ext4_split_extent_at() may result in leaf extent split,
5872 * path must to be revalidated. */
5873 if (split)
5874 goto repeat;
5875
5876 /* Prepare right boundary */
5877 len = count;
5878 if (len > e1_blk + e1_len - lblk1)
5879 len = e1_blk + e1_len - lblk1;
5880 if (len > e2_blk + e2_len - lblk2)
5881 len = e2_blk + e2_len - lblk2;
5882
5883 if (len != e1_len) {
5884 split = 1;
5885 *erp = ext4_force_split_extent_at(handle, inode1,
5886 &path1, lblk1 + len, 0);
5887 if (unlikely(*erp))
5888 goto finish;
5889 }
5890 if (len != e2_len) {
5891 split = 1;
5892 *erp = ext4_force_split_extent_at(handle, inode2,
5893 &path2, lblk2 + len, 0);
5894 if (*erp)
5895 goto finish;
5896 }
5897 /* ext4_split_extent_at() may result in leaf extent split,
5898 * path must to be revalidated. */
5899 if (split)
5900 goto repeat;
5901
5902 BUG_ON(e2_len != e1_len);
5903 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
5904 if (unlikely(*erp))
5905 goto finish;
5906 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
5907 if (unlikely(*erp))
5908 goto finish;
5909
5910 /* Both extents are fully inside boundaries. Swap it now */
5911 tmp_ex = *ex1;
5912 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
5913 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
5914 ex1->ee_len = cpu_to_le16(e2_len);
5915 ex2->ee_len = cpu_to_le16(e1_len);
5916 if (unwritten)
5917 ext4_ext_mark_unwritten(ex2);
5918 if (ext4_ext_is_unwritten(&tmp_ex))
5919 ext4_ext_mark_unwritten(ex1);
5920
5921 ext4_ext_try_to_merge(handle, inode2, path2, ex2);
5922 ext4_ext_try_to_merge(handle, inode1, path1, ex1);
5923 *erp = ext4_ext_dirty(handle, inode2, path2 +
5924 path2->p_depth);
5925 if (unlikely(*erp))
5926 goto finish;
5927 *erp = ext4_ext_dirty(handle, inode1, path1 +
5928 path1->p_depth);
5929 /*
5930 * Looks scarry ah..? second inode already points to new blocks,
5931 * and it was successfully dirtied. But luckily error may happen
5932 * only due to journal error, so full transaction will be
5933 * aborted anyway.
5934 */
5935 if (unlikely(*erp))
5936 goto finish;
5937 lblk1 += len;
5938 lblk2 += len;
5939 replaced_count += len;
5940 count -= len;
5941
5942 repeat:
5943 ext4_ext_drop_refs(path1);
5944 kfree(path1);
5945 ext4_ext_drop_refs(path2);
5946 kfree(path2);
5947 path1 = path2 = NULL;
5948 }
5949 return replaced_count;
5950}
1/*
2 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
3 * Written by Alex Tomas <alex@clusterfs.com>
4 *
5 * Architecture independence:
6 * Copyright (c) 2005, Bull S.A.
7 * Written by Pierre Peiffer <pierre.peiffer@bull.net>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public Licens
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
21 */
22
23/*
24 * Extents support for EXT4
25 *
26 * TODO:
27 * - ext4*_error() should be used in some situations
28 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
29 * - smart tree reduction
30 */
31
32#include <linux/module.h>
33#include <linux/fs.h>
34#include <linux/time.h>
35#include <linux/jbd2.h>
36#include <linux/highuid.h>
37#include <linux/pagemap.h>
38#include <linux/quotaops.h>
39#include <linux/string.h>
40#include <linux/slab.h>
41#include <linux/falloc.h>
42#include <asm/uaccess.h>
43#include <linux/fiemap.h>
44#include "ext4_jbd2.h"
45#include "ext4_extents.h"
46
47#include <trace/events/ext4.h>
48
49static int ext4_split_extent(handle_t *handle,
50 struct inode *inode,
51 struct ext4_ext_path *path,
52 struct ext4_map_blocks *map,
53 int split_flag,
54 int flags);
55
56static int ext4_ext_truncate_extend_restart(handle_t *handle,
57 struct inode *inode,
58 int needed)
59{
60 int err;
61
62 if (!ext4_handle_valid(handle))
63 return 0;
64 if (handle->h_buffer_credits > needed)
65 return 0;
66 err = ext4_journal_extend(handle, needed);
67 if (err <= 0)
68 return err;
69 err = ext4_truncate_restart_trans(handle, inode, needed);
70 if (err == 0)
71 err = -EAGAIN;
72
73 return err;
74}
75
76/*
77 * could return:
78 * - EROFS
79 * - ENOMEM
80 */
81static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
82 struct ext4_ext_path *path)
83{
84 if (path->p_bh) {
85 /* path points to block */
86 return ext4_journal_get_write_access(handle, path->p_bh);
87 }
88 /* path points to leaf/index in inode body */
89 /* we use in-core data, no need to protect them */
90 return 0;
91}
92
93/*
94 * could return:
95 * - EROFS
96 * - ENOMEM
97 * - EIO
98 */
99static int ext4_ext_dirty(handle_t *handle, struct inode *inode,
100 struct ext4_ext_path *path)
101{
102 int err;
103 if (path->p_bh) {
104 /* path points to block */
105 err = ext4_handle_dirty_metadata(handle, inode, path->p_bh);
106 } else {
107 /* path points to leaf/index in inode body */
108 err = ext4_mark_inode_dirty(handle, inode);
109 }
110 return err;
111}
112
113static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
114 struct ext4_ext_path *path,
115 ext4_lblk_t block)
116{
117 int depth;
118
119 if (path) {
120 struct ext4_extent *ex;
121 depth = path->p_depth;
122
123 /*
124 * Try to predict block placement assuming that we are
125 * filling in a file which will eventually be
126 * non-sparse --- i.e., in the case of libbfd writing
127 * an ELF object sections out-of-order but in a way
128 * the eventually results in a contiguous object or
129 * executable file, or some database extending a table
130 * space file. However, this is actually somewhat
131 * non-ideal if we are writing a sparse file such as
132 * qemu or KVM writing a raw image file that is going
133 * to stay fairly sparse, since it will end up
134 * fragmenting the file system's free space. Maybe we
135 * should have some hueristics or some way to allow
136 * userspace to pass a hint to file system,
137 * especially if the latter case turns out to be
138 * common.
139 */
140 ex = path[depth].p_ext;
141 if (ex) {
142 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
143 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
144
145 if (block > ext_block)
146 return ext_pblk + (block - ext_block);
147 else
148 return ext_pblk - (ext_block - block);
149 }
150
151 /* it looks like index is empty;
152 * try to find starting block from index itself */
153 if (path[depth].p_bh)
154 return path[depth].p_bh->b_blocknr;
155 }
156
157 /* OK. use inode's group */
158 return ext4_inode_to_goal_block(inode);
159}
160
161/*
162 * Allocation for a meta data block
163 */
164static ext4_fsblk_t
165ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
166 struct ext4_ext_path *path,
167 struct ext4_extent *ex, int *err, unsigned int flags)
168{
169 ext4_fsblk_t goal, newblock;
170
171 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
172 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
173 NULL, err);
174 return newblock;
175}
176
177static inline int ext4_ext_space_block(struct inode *inode, int check)
178{
179 int size;
180
181 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
182 / sizeof(struct ext4_extent);
183 if (!check) {
184#ifdef AGGRESSIVE_TEST
185 if (size > 6)
186 size = 6;
187#endif
188 }
189 return size;
190}
191
192static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
193{
194 int size;
195
196 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
197 / sizeof(struct ext4_extent_idx);
198 if (!check) {
199#ifdef AGGRESSIVE_TEST
200 if (size > 5)
201 size = 5;
202#endif
203 }
204 return size;
205}
206
207static inline int ext4_ext_space_root(struct inode *inode, int check)
208{
209 int size;
210
211 size = sizeof(EXT4_I(inode)->i_data);
212 size -= sizeof(struct ext4_extent_header);
213 size /= sizeof(struct ext4_extent);
214 if (!check) {
215#ifdef AGGRESSIVE_TEST
216 if (size > 3)
217 size = 3;
218#endif
219 }
220 return size;
221}
222
223static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
224{
225 int size;
226
227 size = sizeof(EXT4_I(inode)->i_data);
228 size -= sizeof(struct ext4_extent_header);
229 size /= sizeof(struct ext4_extent_idx);
230 if (!check) {
231#ifdef AGGRESSIVE_TEST
232 if (size > 4)
233 size = 4;
234#endif
235 }
236 return size;
237}
238
239/*
240 * Calculate the number of metadata blocks needed
241 * to allocate @blocks
242 * Worse case is one block per extent
243 */
244int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
245{
246 struct ext4_inode_info *ei = EXT4_I(inode);
247 int idxs, num = 0;
248
249 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
250 / sizeof(struct ext4_extent_idx));
251
252 /*
253 * If the new delayed allocation block is contiguous with the
254 * previous da block, it can share index blocks with the
255 * previous block, so we only need to allocate a new index
256 * block every idxs leaf blocks. At ldxs**2 blocks, we need
257 * an additional index block, and at ldxs**3 blocks, yet
258 * another index blocks.
259 */
260 if (ei->i_da_metadata_calc_len &&
261 ei->i_da_metadata_calc_last_lblock+1 == lblock) {
262 if ((ei->i_da_metadata_calc_len % idxs) == 0)
263 num++;
264 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
265 num++;
266 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
267 num++;
268 ei->i_da_metadata_calc_len = 0;
269 } else
270 ei->i_da_metadata_calc_len++;
271 ei->i_da_metadata_calc_last_lblock++;
272 return num;
273 }
274
275 /*
276 * In the worst case we need a new set of index blocks at
277 * every level of the inode's extent tree.
278 */
279 ei->i_da_metadata_calc_len = 1;
280 ei->i_da_metadata_calc_last_lblock = lblock;
281 return ext_depth(inode) + 1;
282}
283
284static int
285ext4_ext_max_entries(struct inode *inode, int depth)
286{
287 int max;
288
289 if (depth == ext_depth(inode)) {
290 if (depth == 0)
291 max = ext4_ext_space_root(inode, 1);
292 else
293 max = ext4_ext_space_root_idx(inode, 1);
294 } else {
295 if (depth == 0)
296 max = ext4_ext_space_block(inode, 1);
297 else
298 max = ext4_ext_space_block_idx(inode, 1);
299 }
300
301 return max;
302}
303
304static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
305{
306 ext4_fsblk_t block = ext4_ext_pblock(ext);
307 int len = ext4_ext_get_actual_len(ext);
308
309 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
310}
311
312static int ext4_valid_extent_idx(struct inode *inode,
313 struct ext4_extent_idx *ext_idx)
314{
315 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
316
317 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
318}
319
320static int ext4_valid_extent_entries(struct inode *inode,
321 struct ext4_extent_header *eh,
322 int depth)
323{
324 struct ext4_extent *ext;
325 struct ext4_extent_idx *ext_idx;
326 unsigned short entries;
327 if (eh->eh_entries == 0)
328 return 1;
329
330 entries = le16_to_cpu(eh->eh_entries);
331
332 if (depth == 0) {
333 /* leaf entries */
334 ext = EXT_FIRST_EXTENT(eh);
335 while (entries) {
336 if (!ext4_valid_extent(inode, ext))
337 return 0;
338 ext++;
339 entries--;
340 }
341 } else {
342 ext_idx = EXT_FIRST_INDEX(eh);
343 while (entries) {
344 if (!ext4_valid_extent_idx(inode, ext_idx))
345 return 0;
346 ext_idx++;
347 entries--;
348 }
349 }
350 return 1;
351}
352
353static int __ext4_ext_check(const char *function, unsigned int line,
354 struct inode *inode, struct ext4_extent_header *eh,
355 int depth)
356{
357 const char *error_msg;
358 int max = 0;
359
360 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
361 error_msg = "invalid magic";
362 goto corrupted;
363 }
364 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
365 error_msg = "unexpected eh_depth";
366 goto corrupted;
367 }
368 if (unlikely(eh->eh_max == 0)) {
369 error_msg = "invalid eh_max";
370 goto corrupted;
371 }
372 max = ext4_ext_max_entries(inode, depth);
373 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
374 error_msg = "too large eh_max";
375 goto corrupted;
376 }
377 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
378 error_msg = "invalid eh_entries";
379 goto corrupted;
380 }
381 if (!ext4_valid_extent_entries(inode, eh, depth)) {
382 error_msg = "invalid extent entries";
383 goto corrupted;
384 }
385 return 0;
386
387corrupted:
388 ext4_error_inode(inode, function, line, 0,
389 "bad header/extent: %s - magic %x, "
390 "entries %u, max %u(%u), depth %u(%u)",
391 error_msg, le16_to_cpu(eh->eh_magic),
392 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
393 max, le16_to_cpu(eh->eh_depth), depth);
394
395 return -EIO;
396}
397
398#define ext4_ext_check(inode, eh, depth) \
399 __ext4_ext_check(__func__, __LINE__, inode, eh, depth)
400
401int ext4_ext_check_inode(struct inode *inode)
402{
403 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode));
404}
405
406#ifdef EXT_DEBUG
407static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
408{
409 int k, l = path->p_depth;
410
411 ext_debug("path:");
412 for (k = 0; k <= l; k++, path++) {
413 if (path->p_idx) {
414 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
415 ext4_idx_pblock(path->p_idx));
416 } else if (path->p_ext) {
417 ext_debug(" %d:[%d]%d:%llu ",
418 le32_to_cpu(path->p_ext->ee_block),
419 ext4_ext_is_uninitialized(path->p_ext),
420 ext4_ext_get_actual_len(path->p_ext),
421 ext4_ext_pblock(path->p_ext));
422 } else
423 ext_debug(" []");
424 }
425 ext_debug("\n");
426}
427
428static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
429{
430 int depth = ext_depth(inode);
431 struct ext4_extent_header *eh;
432 struct ext4_extent *ex;
433 int i;
434
435 if (!path)
436 return;
437
438 eh = path[depth].p_hdr;
439 ex = EXT_FIRST_EXTENT(eh);
440
441 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
442
443 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
444 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
445 ext4_ext_is_uninitialized(ex),
446 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
447 }
448 ext_debug("\n");
449}
450
451static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
452 ext4_fsblk_t newblock, int level)
453{
454 int depth = ext_depth(inode);
455 struct ext4_extent *ex;
456
457 if (depth != level) {
458 struct ext4_extent_idx *idx;
459 idx = path[level].p_idx;
460 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
461 ext_debug("%d: move %d:%llu in new index %llu\n", level,
462 le32_to_cpu(idx->ei_block),
463 ext4_idx_pblock(idx),
464 newblock);
465 idx++;
466 }
467
468 return;
469 }
470
471 ex = path[depth].p_ext;
472 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
473 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
474 le32_to_cpu(ex->ee_block),
475 ext4_ext_pblock(ex),
476 ext4_ext_is_uninitialized(ex),
477 ext4_ext_get_actual_len(ex),
478 newblock);
479 ex++;
480 }
481}
482
483#else
484#define ext4_ext_show_path(inode, path)
485#define ext4_ext_show_leaf(inode, path)
486#define ext4_ext_show_move(inode, path, newblock, level)
487#endif
488
489void ext4_ext_drop_refs(struct ext4_ext_path *path)
490{
491 int depth = path->p_depth;
492 int i;
493
494 for (i = 0; i <= depth; i++, path++)
495 if (path->p_bh) {
496 brelse(path->p_bh);
497 path->p_bh = NULL;
498 }
499}
500
501/*
502 * ext4_ext_binsearch_idx:
503 * binary search for the closest index of the given block
504 * the header must be checked before calling this
505 */
506static void
507ext4_ext_binsearch_idx(struct inode *inode,
508 struct ext4_ext_path *path, ext4_lblk_t block)
509{
510 struct ext4_extent_header *eh = path->p_hdr;
511 struct ext4_extent_idx *r, *l, *m;
512
513
514 ext_debug("binsearch for %u(idx): ", block);
515
516 l = EXT_FIRST_INDEX(eh) + 1;
517 r = EXT_LAST_INDEX(eh);
518 while (l <= r) {
519 m = l + (r - l) / 2;
520 if (block < le32_to_cpu(m->ei_block))
521 r = m - 1;
522 else
523 l = m + 1;
524 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
525 m, le32_to_cpu(m->ei_block),
526 r, le32_to_cpu(r->ei_block));
527 }
528
529 path->p_idx = l - 1;
530 ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block),
531 ext4_idx_pblock(path->p_idx));
532
533#ifdef CHECK_BINSEARCH
534 {
535 struct ext4_extent_idx *chix, *ix;
536 int k;
537
538 chix = ix = EXT_FIRST_INDEX(eh);
539 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
540 if (k != 0 &&
541 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
542 printk(KERN_DEBUG "k=%d, ix=0x%p, "
543 "first=0x%p\n", k,
544 ix, EXT_FIRST_INDEX(eh));
545 printk(KERN_DEBUG "%u <= %u\n",
546 le32_to_cpu(ix->ei_block),
547 le32_to_cpu(ix[-1].ei_block));
548 }
549 BUG_ON(k && le32_to_cpu(ix->ei_block)
550 <= le32_to_cpu(ix[-1].ei_block));
551 if (block < le32_to_cpu(ix->ei_block))
552 break;
553 chix = ix;
554 }
555 BUG_ON(chix != path->p_idx);
556 }
557#endif
558
559}
560
561/*
562 * ext4_ext_binsearch:
563 * binary search for closest extent of the given block
564 * the header must be checked before calling this
565 */
566static void
567ext4_ext_binsearch(struct inode *inode,
568 struct ext4_ext_path *path, ext4_lblk_t block)
569{
570 struct ext4_extent_header *eh = path->p_hdr;
571 struct ext4_extent *r, *l, *m;
572
573 if (eh->eh_entries == 0) {
574 /*
575 * this leaf is empty:
576 * we get such a leaf in split/add case
577 */
578 return;
579 }
580
581 ext_debug("binsearch for %u: ", block);
582
583 l = EXT_FIRST_EXTENT(eh) + 1;
584 r = EXT_LAST_EXTENT(eh);
585
586 while (l <= r) {
587 m = l + (r - l) / 2;
588 if (block < le32_to_cpu(m->ee_block))
589 r = m - 1;
590 else
591 l = m + 1;
592 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
593 m, le32_to_cpu(m->ee_block),
594 r, le32_to_cpu(r->ee_block));
595 }
596
597 path->p_ext = l - 1;
598 ext_debug(" -> %d:%llu:[%d]%d ",
599 le32_to_cpu(path->p_ext->ee_block),
600 ext4_ext_pblock(path->p_ext),
601 ext4_ext_is_uninitialized(path->p_ext),
602 ext4_ext_get_actual_len(path->p_ext));
603
604#ifdef CHECK_BINSEARCH
605 {
606 struct ext4_extent *chex, *ex;
607 int k;
608
609 chex = ex = EXT_FIRST_EXTENT(eh);
610 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
611 BUG_ON(k && le32_to_cpu(ex->ee_block)
612 <= le32_to_cpu(ex[-1].ee_block));
613 if (block < le32_to_cpu(ex->ee_block))
614 break;
615 chex = ex;
616 }
617 BUG_ON(chex != path->p_ext);
618 }
619#endif
620
621}
622
623int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
624{
625 struct ext4_extent_header *eh;
626
627 eh = ext_inode_hdr(inode);
628 eh->eh_depth = 0;
629 eh->eh_entries = 0;
630 eh->eh_magic = EXT4_EXT_MAGIC;
631 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
632 ext4_mark_inode_dirty(handle, inode);
633 ext4_ext_invalidate_cache(inode);
634 return 0;
635}
636
637struct ext4_ext_path *
638ext4_ext_find_extent(struct inode *inode, ext4_lblk_t block,
639 struct ext4_ext_path *path)
640{
641 struct ext4_extent_header *eh;
642 struct buffer_head *bh;
643 short int depth, i, ppos = 0, alloc = 0;
644
645 eh = ext_inode_hdr(inode);
646 depth = ext_depth(inode);
647
648 /* account possible depth increase */
649 if (!path) {
650 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
651 GFP_NOFS);
652 if (!path)
653 return ERR_PTR(-ENOMEM);
654 alloc = 1;
655 }
656 path[0].p_hdr = eh;
657 path[0].p_bh = NULL;
658
659 i = depth;
660 /* walk through the tree */
661 while (i) {
662 int need_to_validate = 0;
663
664 ext_debug("depth %d: num %d, max %d\n",
665 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
666
667 ext4_ext_binsearch_idx(inode, path + ppos, block);
668 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
669 path[ppos].p_depth = i;
670 path[ppos].p_ext = NULL;
671
672 bh = sb_getblk(inode->i_sb, path[ppos].p_block);
673 if (unlikely(!bh))
674 goto err;
675 if (!bh_uptodate_or_lock(bh)) {
676 trace_ext4_ext_load_extent(inode, block,
677 path[ppos].p_block);
678 if (bh_submit_read(bh) < 0) {
679 put_bh(bh);
680 goto err;
681 }
682 /* validate the extent entries */
683 need_to_validate = 1;
684 }
685 eh = ext_block_hdr(bh);
686 ppos++;
687 if (unlikely(ppos > depth)) {
688 put_bh(bh);
689 EXT4_ERROR_INODE(inode,
690 "ppos %d > depth %d", ppos, depth);
691 goto err;
692 }
693 path[ppos].p_bh = bh;
694 path[ppos].p_hdr = eh;
695 i--;
696
697 if (need_to_validate && ext4_ext_check(inode, eh, i))
698 goto err;
699 }
700
701 path[ppos].p_depth = i;
702 path[ppos].p_ext = NULL;
703 path[ppos].p_idx = NULL;
704
705 /* find extent */
706 ext4_ext_binsearch(inode, path + ppos, block);
707 /* if not an empty leaf */
708 if (path[ppos].p_ext)
709 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
710
711 ext4_ext_show_path(inode, path);
712
713 return path;
714
715err:
716 ext4_ext_drop_refs(path);
717 if (alloc)
718 kfree(path);
719 return ERR_PTR(-EIO);
720}
721
722/*
723 * ext4_ext_insert_index:
724 * insert new index [@logical;@ptr] into the block at @curp;
725 * check where to insert: before @curp or after @curp
726 */
727static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
728 struct ext4_ext_path *curp,
729 int logical, ext4_fsblk_t ptr)
730{
731 struct ext4_extent_idx *ix;
732 int len, err;
733
734 err = ext4_ext_get_access(handle, inode, curp);
735 if (err)
736 return err;
737
738 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
739 EXT4_ERROR_INODE(inode,
740 "logical %d == ei_block %d!",
741 logical, le32_to_cpu(curp->p_idx->ei_block));
742 return -EIO;
743 }
744
745 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
746 >= le16_to_cpu(curp->p_hdr->eh_max))) {
747 EXT4_ERROR_INODE(inode,
748 "eh_entries %d >= eh_max %d!",
749 le16_to_cpu(curp->p_hdr->eh_entries),
750 le16_to_cpu(curp->p_hdr->eh_max));
751 return -EIO;
752 }
753
754 len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx;
755 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
756 /* insert after */
757 if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) {
758 len = (len - 1) * sizeof(struct ext4_extent_idx);
759 len = len < 0 ? 0 : len;
760 ext_debug("insert new index %d after: %llu. "
761 "move %d from 0x%p to 0x%p\n",
762 logical, ptr, len,
763 (curp->p_idx + 1), (curp->p_idx + 2));
764 memmove(curp->p_idx + 2, curp->p_idx + 1, len);
765 }
766 ix = curp->p_idx + 1;
767 } else {
768 /* insert before */
769 len = len * sizeof(struct ext4_extent_idx);
770 len = len < 0 ? 0 : len;
771 ext_debug("insert new index %d before: %llu. "
772 "move %d from 0x%p to 0x%p\n",
773 logical, ptr, len,
774 curp->p_idx, (curp->p_idx + 1));
775 memmove(curp->p_idx + 1, curp->p_idx, len);
776 ix = curp->p_idx;
777 }
778
779 ix->ei_block = cpu_to_le32(logical);
780 ext4_idx_store_pblock(ix, ptr);
781 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
782
783 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
784 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
785 return -EIO;
786 }
787
788 err = ext4_ext_dirty(handle, inode, curp);
789 ext4_std_error(inode->i_sb, err);
790
791 return err;
792}
793
794/*
795 * ext4_ext_split:
796 * inserts new subtree into the path, using free index entry
797 * at depth @at:
798 * - allocates all needed blocks (new leaf and all intermediate index blocks)
799 * - makes decision where to split
800 * - moves remaining extents and index entries (right to the split point)
801 * into the newly allocated blocks
802 * - initializes subtree
803 */
804static int ext4_ext_split(handle_t *handle, struct inode *inode,
805 unsigned int flags,
806 struct ext4_ext_path *path,
807 struct ext4_extent *newext, int at)
808{
809 struct buffer_head *bh = NULL;
810 int depth = ext_depth(inode);
811 struct ext4_extent_header *neh;
812 struct ext4_extent_idx *fidx;
813 int i = at, k, m, a;
814 ext4_fsblk_t newblock, oldblock;
815 __le32 border;
816 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
817 int err = 0;
818
819 /* make decision: where to split? */
820 /* FIXME: now decision is simplest: at current extent */
821
822 /* if current leaf will be split, then we should use
823 * border from split point */
824 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
825 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
826 return -EIO;
827 }
828 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
829 border = path[depth].p_ext[1].ee_block;
830 ext_debug("leaf will be split."
831 " next leaf starts at %d\n",
832 le32_to_cpu(border));
833 } else {
834 border = newext->ee_block;
835 ext_debug("leaf will be added."
836 " next leaf starts at %d\n",
837 le32_to_cpu(border));
838 }
839
840 /*
841 * If error occurs, then we break processing
842 * and mark filesystem read-only. index won't
843 * be inserted and tree will be in consistent
844 * state. Next mount will repair buffers too.
845 */
846
847 /*
848 * Get array to track all allocated blocks.
849 * We need this to handle errors and free blocks
850 * upon them.
851 */
852 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
853 if (!ablocks)
854 return -ENOMEM;
855
856 /* allocate all needed blocks */
857 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
858 for (a = 0; a < depth - at; a++) {
859 newblock = ext4_ext_new_meta_block(handle, inode, path,
860 newext, &err, flags);
861 if (newblock == 0)
862 goto cleanup;
863 ablocks[a] = newblock;
864 }
865
866 /* initialize new leaf */
867 newblock = ablocks[--a];
868 if (unlikely(newblock == 0)) {
869 EXT4_ERROR_INODE(inode, "newblock == 0!");
870 err = -EIO;
871 goto cleanup;
872 }
873 bh = sb_getblk(inode->i_sb, newblock);
874 if (!bh) {
875 err = -EIO;
876 goto cleanup;
877 }
878 lock_buffer(bh);
879
880 err = ext4_journal_get_create_access(handle, bh);
881 if (err)
882 goto cleanup;
883
884 neh = ext_block_hdr(bh);
885 neh->eh_entries = 0;
886 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
887 neh->eh_magic = EXT4_EXT_MAGIC;
888 neh->eh_depth = 0;
889
890 /* move remainder of path[depth] to the new leaf */
891 if (unlikely(path[depth].p_hdr->eh_entries !=
892 path[depth].p_hdr->eh_max)) {
893 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
894 path[depth].p_hdr->eh_entries,
895 path[depth].p_hdr->eh_max);
896 err = -EIO;
897 goto cleanup;
898 }
899 /* start copy from next extent */
900 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
901 ext4_ext_show_move(inode, path, newblock, depth);
902 if (m) {
903 struct ext4_extent *ex;
904 ex = EXT_FIRST_EXTENT(neh);
905 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
906 le16_add_cpu(&neh->eh_entries, m);
907 }
908
909 set_buffer_uptodate(bh);
910 unlock_buffer(bh);
911
912 err = ext4_handle_dirty_metadata(handle, inode, bh);
913 if (err)
914 goto cleanup;
915 brelse(bh);
916 bh = NULL;
917
918 /* correct old leaf */
919 if (m) {
920 err = ext4_ext_get_access(handle, inode, path + depth);
921 if (err)
922 goto cleanup;
923 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
924 err = ext4_ext_dirty(handle, inode, path + depth);
925 if (err)
926 goto cleanup;
927
928 }
929
930 /* create intermediate indexes */
931 k = depth - at - 1;
932 if (unlikely(k < 0)) {
933 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
934 err = -EIO;
935 goto cleanup;
936 }
937 if (k)
938 ext_debug("create %d intermediate indices\n", k);
939 /* insert new index into current index block */
940 /* current depth stored in i var */
941 i = depth - 1;
942 while (k--) {
943 oldblock = newblock;
944 newblock = ablocks[--a];
945 bh = sb_getblk(inode->i_sb, newblock);
946 if (!bh) {
947 err = -EIO;
948 goto cleanup;
949 }
950 lock_buffer(bh);
951
952 err = ext4_journal_get_create_access(handle, bh);
953 if (err)
954 goto cleanup;
955
956 neh = ext_block_hdr(bh);
957 neh->eh_entries = cpu_to_le16(1);
958 neh->eh_magic = EXT4_EXT_MAGIC;
959 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
960 neh->eh_depth = cpu_to_le16(depth - i);
961 fidx = EXT_FIRST_INDEX(neh);
962 fidx->ei_block = border;
963 ext4_idx_store_pblock(fidx, oldblock);
964
965 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
966 i, newblock, le32_to_cpu(border), oldblock);
967
968 /* move remainder of path[i] to the new index block */
969 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
970 EXT_LAST_INDEX(path[i].p_hdr))) {
971 EXT4_ERROR_INODE(inode,
972 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
973 le32_to_cpu(path[i].p_ext->ee_block));
974 err = -EIO;
975 goto cleanup;
976 }
977 /* start copy indexes */
978 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
979 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
980 EXT_MAX_INDEX(path[i].p_hdr));
981 ext4_ext_show_move(inode, path, newblock, i);
982 if (m) {
983 memmove(++fidx, path[i].p_idx,
984 sizeof(struct ext4_extent_idx) * m);
985 le16_add_cpu(&neh->eh_entries, m);
986 }
987 set_buffer_uptodate(bh);
988 unlock_buffer(bh);
989
990 err = ext4_handle_dirty_metadata(handle, inode, bh);
991 if (err)
992 goto cleanup;
993 brelse(bh);
994 bh = NULL;
995
996 /* correct old index */
997 if (m) {
998 err = ext4_ext_get_access(handle, inode, path + i);
999 if (err)
1000 goto cleanup;
1001 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1002 err = ext4_ext_dirty(handle, inode, path + i);
1003 if (err)
1004 goto cleanup;
1005 }
1006
1007 i--;
1008 }
1009
1010 /* insert new index */
1011 err = ext4_ext_insert_index(handle, inode, path + at,
1012 le32_to_cpu(border), newblock);
1013
1014cleanup:
1015 if (bh) {
1016 if (buffer_locked(bh))
1017 unlock_buffer(bh);
1018 brelse(bh);
1019 }
1020
1021 if (err) {
1022 /* free all allocated blocks in error case */
1023 for (i = 0; i < depth; i++) {
1024 if (!ablocks[i])
1025 continue;
1026 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1027 EXT4_FREE_BLOCKS_METADATA);
1028 }
1029 }
1030 kfree(ablocks);
1031
1032 return err;
1033}
1034
1035/*
1036 * ext4_ext_grow_indepth:
1037 * implements tree growing procedure:
1038 * - allocates new block
1039 * - moves top-level data (index block or leaf) into the new block
1040 * - initializes new top-level, creating index that points to the
1041 * just created block
1042 */
1043static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1044 unsigned int flags,
1045 struct ext4_ext_path *path,
1046 struct ext4_extent *newext)
1047{
1048 struct ext4_ext_path *curp = path;
1049 struct ext4_extent_header *neh;
1050 struct buffer_head *bh;
1051 ext4_fsblk_t newblock;
1052 int err = 0;
1053
1054 newblock = ext4_ext_new_meta_block(handle, inode, path,
1055 newext, &err, flags);
1056 if (newblock == 0)
1057 return err;
1058
1059 bh = sb_getblk(inode->i_sb, newblock);
1060 if (!bh) {
1061 err = -EIO;
1062 ext4_std_error(inode->i_sb, err);
1063 return err;
1064 }
1065 lock_buffer(bh);
1066
1067 err = ext4_journal_get_create_access(handle, bh);
1068 if (err) {
1069 unlock_buffer(bh);
1070 goto out;
1071 }
1072
1073 /* move top-level index/leaf into new block */
1074 memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data));
1075
1076 /* set size of new block */
1077 neh = ext_block_hdr(bh);
1078 /* old root could have indexes or leaves
1079 * so calculate e_max right way */
1080 if (ext_depth(inode))
1081 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1082 else
1083 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1084 neh->eh_magic = EXT4_EXT_MAGIC;
1085 set_buffer_uptodate(bh);
1086 unlock_buffer(bh);
1087
1088 err = ext4_handle_dirty_metadata(handle, inode, bh);
1089 if (err)
1090 goto out;
1091
1092 /* create index in new top-level index: num,max,pointer */
1093 err = ext4_ext_get_access(handle, inode, curp);
1094 if (err)
1095 goto out;
1096
1097 curp->p_hdr->eh_magic = EXT4_EXT_MAGIC;
1098 curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1099 curp->p_hdr->eh_entries = cpu_to_le16(1);
1100 curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr);
1101
1102 if (path[0].p_hdr->eh_depth)
1103 curp->p_idx->ei_block =
1104 EXT_FIRST_INDEX(path[0].p_hdr)->ei_block;
1105 else
1106 curp->p_idx->ei_block =
1107 EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block;
1108 ext4_idx_store_pblock(curp->p_idx, newblock);
1109
1110 neh = ext_inode_hdr(inode);
1111 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1112 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1113 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1114 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1115
1116 neh->eh_depth = cpu_to_le16(path->p_depth + 1);
1117 err = ext4_ext_dirty(handle, inode, curp);
1118out:
1119 brelse(bh);
1120
1121 return err;
1122}
1123
1124/*
1125 * ext4_ext_create_new_leaf:
1126 * finds empty index and adds new leaf.
1127 * if no free index is found, then it requests in-depth growing.
1128 */
1129static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1130 unsigned int flags,
1131 struct ext4_ext_path *path,
1132 struct ext4_extent *newext)
1133{
1134 struct ext4_ext_path *curp;
1135 int depth, i, err = 0;
1136
1137repeat:
1138 i = depth = ext_depth(inode);
1139
1140 /* walk up to the tree and look for free index entry */
1141 curp = path + depth;
1142 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1143 i--;
1144 curp--;
1145 }
1146
1147 /* we use already allocated block for index block,
1148 * so subsequent data blocks should be contiguous */
1149 if (EXT_HAS_FREE_INDEX(curp)) {
1150 /* if we found index with free entry, then use that
1151 * entry: create all needed subtree and add new leaf */
1152 err = ext4_ext_split(handle, inode, flags, path, newext, i);
1153 if (err)
1154 goto out;
1155
1156 /* refill path */
1157 ext4_ext_drop_refs(path);
1158 path = ext4_ext_find_extent(inode,
1159 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1160 path);
1161 if (IS_ERR(path))
1162 err = PTR_ERR(path);
1163 } else {
1164 /* tree is full, time to grow in depth */
1165 err = ext4_ext_grow_indepth(handle, inode, flags,
1166 path, newext);
1167 if (err)
1168 goto out;
1169
1170 /* refill path */
1171 ext4_ext_drop_refs(path);
1172 path = ext4_ext_find_extent(inode,
1173 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1174 path);
1175 if (IS_ERR(path)) {
1176 err = PTR_ERR(path);
1177 goto out;
1178 }
1179
1180 /*
1181 * only first (depth 0 -> 1) produces free space;
1182 * in all other cases we have to split the grown tree
1183 */
1184 depth = ext_depth(inode);
1185 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1186 /* now we need to split */
1187 goto repeat;
1188 }
1189 }
1190
1191out:
1192 return err;
1193}
1194
1195/*
1196 * search the closest allocated block to the left for *logical
1197 * and returns it at @logical + it's physical address at @phys
1198 * if *logical is the smallest allocated block, the function
1199 * returns 0 at @phys
1200 * return value contains 0 (success) or error code
1201 */
1202static int ext4_ext_search_left(struct inode *inode,
1203 struct ext4_ext_path *path,
1204 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1205{
1206 struct ext4_extent_idx *ix;
1207 struct ext4_extent *ex;
1208 int depth, ee_len;
1209
1210 if (unlikely(path == NULL)) {
1211 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1212 return -EIO;
1213 }
1214 depth = path->p_depth;
1215 *phys = 0;
1216
1217 if (depth == 0 && path->p_ext == NULL)
1218 return 0;
1219
1220 /* usually extent in the path covers blocks smaller
1221 * then *logical, but it can be that extent is the
1222 * first one in the file */
1223
1224 ex = path[depth].p_ext;
1225 ee_len = ext4_ext_get_actual_len(ex);
1226 if (*logical < le32_to_cpu(ex->ee_block)) {
1227 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1228 EXT4_ERROR_INODE(inode,
1229 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1230 *logical, le32_to_cpu(ex->ee_block));
1231 return -EIO;
1232 }
1233 while (--depth >= 0) {
1234 ix = path[depth].p_idx;
1235 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1236 EXT4_ERROR_INODE(inode,
1237 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1238 ix != NULL ? ix->ei_block : 0,
1239 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1240 EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block : 0,
1241 depth);
1242 return -EIO;
1243 }
1244 }
1245 return 0;
1246 }
1247
1248 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1249 EXT4_ERROR_INODE(inode,
1250 "logical %d < ee_block %d + ee_len %d!",
1251 *logical, le32_to_cpu(ex->ee_block), ee_len);
1252 return -EIO;
1253 }
1254
1255 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1256 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1257 return 0;
1258}
1259
1260/*
1261 * search the closest allocated block to the right for *logical
1262 * and returns it at @logical + it's physical address at @phys
1263 * if *logical is the smallest allocated block, the function
1264 * returns 0 at @phys
1265 * return value contains 0 (success) or error code
1266 */
1267static int ext4_ext_search_right(struct inode *inode,
1268 struct ext4_ext_path *path,
1269 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1270{
1271 struct buffer_head *bh = NULL;
1272 struct ext4_extent_header *eh;
1273 struct ext4_extent_idx *ix;
1274 struct ext4_extent *ex;
1275 ext4_fsblk_t block;
1276 int depth; /* Note, NOT eh_depth; depth from top of tree */
1277 int ee_len;
1278
1279 if (unlikely(path == NULL)) {
1280 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1281 return -EIO;
1282 }
1283 depth = path->p_depth;
1284 *phys = 0;
1285
1286 if (depth == 0 && path->p_ext == NULL)
1287 return 0;
1288
1289 /* usually extent in the path covers blocks smaller
1290 * then *logical, but it can be that extent is the
1291 * first one in the file */
1292
1293 ex = path[depth].p_ext;
1294 ee_len = ext4_ext_get_actual_len(ex);
1295 if (*logical < le32_to_cpu(ex->ee_block)) {
1296 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1297 EXT4_ERROR_INODE(inode,
1298 "first_extent(path[%d].p_hdr) != ex",
1299 depth);
1300 return -EIO;
1301 }
1302 while (--depth >= 0) {
1303 ix = path[depth].p_idx;
1304 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1305 EXT4_ERROR_INODE(inode,
1306 "ix != EXT_FIRST_INDEX *logical %d!",
1307 *logical);
1308 return -EIO;
1309 }
1310 }
1311 *logical = le32_to_cpu(ex->ee_block);
1312 *phys = ext4_ext_pblock(ex);
1313 return 0;
1314 }
1315
1316 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1317 EXT4_ERROR_INODE(inode,
1318 "logical %d < ee_block %d + ee_len %d!",
1319 *logical, le32_to_cpu(ex->ee_block), ee_len);
1320 return -EIO;
1321 }
1322
1323 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1324 /* next allocated block in this leaf */
1325 ex++;
1326 *logical = le32_to_cpu(ex->ee_block);
1327 *phys = ext4_ext_pblock(ex);
1328 return 0;
1329 }
1330
1331 /* go up and search for index to the right */
1332 while (--depth >= 0) {
1333 ix = path[depth].p_idx;
1334 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1335 goto got_index;
1336 }
1337
1338 /* we've gone up to the root and found no index to the right */
1339 return 0;
1340
1341got_index:
1342 /* we've found index to the right, let's
1343 * follow it and find the closest allocated
1344 * block to the right */
1345 ix++;
1346 block = ext4_idx_pblock(ix);
1347 while (++depth < path->p_depth) {
1348 bh = sb_bread(inode->i_sb, block);
1349 if (bh == NULL)
1350 return -EIO;
1351 eh = ext_block_hdr(bh);
1352 /* subtract from p_depth to get proper eh_depth */
1353 if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
1354 put_bh(bh);
1355 return -EIO;
1356 }
1357 ix = EXT_FIRST_INDEX(eh);
1358 block = ext4_idx_pblock(ix);
1359 put_bh(bh);
1360 }
1361
1362 bh = sb_bread(inode->i_sb, block);
1363 if (bh == NULL)
1364 return -EIO;
1365 eh = ext_block_hdr(bh);
1366 if (ext4_ext_check(inode, eh, path->p_depth - depth)) {
1367 put_bh(bh);
1368 return -EIO;
1369 }
1370 ex = EXT_FIRST_EXTENT(eh);
1371 *logical = le32_to_cpu(ex->ee_block);
1372 *phys = ext4_ext_pblock(ex);
1373 put_bh(bh);
1374 return 0;
1375}
1376
1377/*
1378 * ext4_ext_next_allocated_block:
1379 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1380 * NOTE: it considers block number from index entry as
1381 * allocated block. Thus, index entries have to be consistent
1382 * with leaves.
1383 */
1384static ext4_lblk_t
1385ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1386{
1387 int depth;
1388
1389 BUG_ON(path == NULL);
1390 depth = path->p_depth;
1391
1392 if (depth == 0 && path->p_ext == NULL)
1393 return EXT_MAX_BLOCKS;
1394
1395 while (depth >= 0) {
1396 if (depth == path->p_depth) {
1397 /* leaf */
1398 if (path[depth].p_ext !=
1399 EXT_LAST_EXTENT(path[depth].p_hdr))
1400 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1401 } else {
1402 /* index */
1403 if (path[depth].p_idx !=
1404 EXT_LAST_INDEX(path[depth].p_hdr))
1405 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1406 }
1407 depth--;
1408 }
1409
1410 return EXT_MAX_BLOCKS;
1411}
1412
1413/*
1414 * ext4_ext_next_leaf_block:
1415 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1416 */
1417static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1418{
1419 int depth;
1420
1421 BUG_ON(path == NULL);
1422 depth = path->p_depth;
1423
1424 /* zero-tree has no leaf blocks at all */
1425 if (depth == 0)
1426 return EXT_MAX_BLOCKS;
1427
1428 /* go to index block */
1429 depth--;
1430
1431 while (depth >= 0) {
1432 if (path[depth].p_idx !=
1433 EXT_LAST_INDEX(path[depth].p_hdr))
1434 return (ext4_lblk_t)
1435 le32_to_cpu(path[depth].p_idx[1].ei_block);
1436 depth--;
1437 }
1438
1439 return EXT_MAX_BLOCKS;
1440}
1441
1442/*
1443 * ext4_ext_correct_indexes:
1444 * if leaf gets modified and modified extent is first in the leaf,
1445 * then we have to correct all indexes above.
1446 * TODO: do we need to correct tree in all cases?
1447 */
1448static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1449 struct ext4_ext_path *path)
1450{
1451 struct ext4_extent_header *eh;
1452 int depth = ext_depth(inode);
1453 struct ext4_extent *ex;
1454 __le32 border;
1455 int k, err = 0;
1456
1457 eh = path[depth].p_hdr;
1458 ex = path[depth].p_ext;
1459
1460 if (unlikely(ex == NULL || eh == NULL)) {
1461 EXT4_ERROR_INODE(inode,
1462 "ex %p == NULL or eh %p == NULL", ex, eh);
1463 return -EIO;
1464 }
1465
1466 if (depth == 0) {
1467 /* there is no tree at all */
1468 return 0;
1469 }
1470
1471 if (ex != EXT_FIRST_EXTENT(eh)) {
1472 /* we correct tree if first leaf got modified only */
1473 return 0;
1474 }
1475
1476 /*
1477 * TODO: we need correction if border is smaller than current one
1478 */
1479 k = depth - 1;
1480 border = path[depth].p_ext->ee_block;
1481 err = ext4_ext_get_access(handle, inode, path + k);
1482 if (err)
1483 return err;
1484 path[k].p_idx->ei_block = border;
1485 err = ext4_ext_dirty(handle, inode, path + k);
1486 if (err)
1487 return err;
1488
1489 while (k--) {
1490 /* change all left-side indexes */
1491 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1492 break;
1493 err = ext4_ext_get_access(handle, inode, path + k);
1494 if (err)
1495 break;
1496 path[k].p_idx->ei_block = border;
1497 err = ext4_ext_dirty(handle, inode, path + k);
1498 if (err)
1499 break;
1500 }
1501
1502 return err;
1503}
1504
1505int
1506ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1507 struct ext4_extent *ex2)
1508{
1509 unsigned short ext1_ee_len, ext2_ee_len, max_len;
1510
1511 /*
1512 * Make sure that either both extents are uninitialized, or
1513 * both are _not_.
1514 */
1515 if (ext4_ext_is_uninitialized(ex1) ^ ext4_ext_is_uninitialized(ex2))
1516 return 0;
1517
1518 if (ext4_ext_is_uninitialized(ex1))
1519 max_len = EXT_UNINIT_MAX_LEN;
1520 else
1521 max_len = EXT_INIT_MAX_LEN;
1522
1523 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1524 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1525
1526 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1527 le32_to_cpu(ex2->ee_block))
1528 return 0;
1529
1530 /*
1531 * To allow future support for preallocated extents to be added
1532 * as an RO_COMPAT feature, refuse to merge to extents if
1533 * this can result in the top bit of ee_len being set.
1534 */
1535 if (ext1_ee_len + ext2_ee_len > max_len)
1536 return 0;
1537#ifdef AGGRESSIVE_TEST
1538 if (ext1_ee_len >= 4)
1539 return 0;
1540#endif
1541
1542 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1543 return 1;
1544 return 0;
1545}
1546
1547/*
1548 * This function tries to merge the "ex" extent to the next extent in the tree.
1549 * It always tries to merge towards right. If you want to merge towards
1550 * left, pass "ex - 1" as argument instead of "ex".
1551 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1552 * 1 if they got merged.
1553 */
1554static int ext4_ext_try_to_merge_right(struct inode *inode,
1555 struct ext4_ext_path *path,
1556 struct ext4_extent *ex)
1557{
1558 struct ext4_extent_header *eh;
1559 unsigned int depth, len;
1560 int merge_done = 0;
1561 int uninitialized = 0;
1562
1563 depth = ext_depth(inode);
1564 BUG_ON(path[depth].p_hdr == NULL);
1565 eh = path[depth].p_hdr;
1566
1567 while (ex < EXT_LAST_EXTENT(eh)) {
1568 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1569 break;
1570 /* merge with next extent! */
1571 if (ext4_ext_is_uninitialized(ex))
1572 uninitialized = 1;
1573 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1574 + ext4_ext_get_actual_len(ex + 1));
1575 if (uninitialized)
1576 ext4_ext_mark_uninitialized(ex);
1577
1578 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1579 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1580 * sizeof(struct ext4_extent);
1581 memmove(ex + 1, ex + 2, len);
1582 }
1583 le16_add_cpu(&eh->eh_entries, -1);
1584 merge_done = 1;
1585 WARN_ON(eh->eh_entries == 0);
1586 if (!eh->eh_entries)
1587 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1588 }
1589
1590 return merge_done;
1591}
1592
1593/*
1594 * This function tries to merge the @ex extent to neighbours in the tree.
1595 * return 1 if merge left else 0.
1596 */
1597static int ext4_ext_try_to_merge(struct inode *inode,
1598 struct ext4_ext_path *path,
1599 struct ext4_extent *ex) {
1600 struct ext4_extent_header *eh;
1601 unsigned int depth;
1602 int merge_done = 0;
1603 int ret = 0;
1604
1605 depth = ext_depth(inode);
1606 BUG_ON(path[depth].p_hdr == NULL);
1607 eh = path[depth].p_hdr;
1608
1609 if (ex > EXT_FIRST_EXTENT(eh))
1610 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1611
1612 if (!merge_done)
1613 ret = ext4_ext_try_to_merge_right(inode, path, ex);
1614
1615 return ret;
1616}
1617
1618/*
1619 * check if a portion of the "newext" extent overlaps with an
1620 * existing extent.
1621 *
1622 * If there is an overlap discovered, it updates the length of the newext
1623 * such that there will be no overlap, and then returns 1.
1624 * If there is no overlap found, it returns 0.
1625 */
1626static unsigned int ext4_ext_check_overlap(struct inode *inode,
1627 struct ext4_extent *newext,
1628 struct ext4_ext_path *path)
1629{
1630 ext4_lblk_t b1, b2;
1631 unsigned int depth, len1;
1632 unsigned int ret = 0;
1633
1634 b1 = le32_to_cpu(newext->ee_block);
1635 len1 = ext4_ext_get_actual_len(newext);
1636 depth = ext_depth(inode);
1637 if (!path[depth].p_ext)
1638 goto out;
1639 b2 = le32_to_cpu(path[depth].p_ext->ee_block);
1640
1641 /*
1642 * get the next allocated block if the extent in the path
1643 * is before the requested block(s)
1644 */
1645 if (b2 < b1) {
1646 b2 = ext4_ext_next_allocated_block(path);
1647 if (b2 == EXT_MAX_BLOCKS)
1648 goto out;
1649 }
1650
1651 /* check for wrap through zero on extent logical start block*/
1652 if (b1 + len1 < b1) {
1653 len1 = EXT_MAX_BLOCKS - b1;
1654 newext->ee_len = cpu_to_le16(len1);
1655 ret = 1;
1656 }
1657
1658 /* check for overlap */
1659 if (b1 + len1 > b2) {
1660 newext->ee_len = cpu_to_le16(b2 - b1);
1661 ret = 1;
1662 }
1663out:
1664 return ret;
1665}
1666
1667/*
1668 * ext4_ext_insert_extent:
1669 * tries to merge requsted extent into the existing extent or
1670 * inserts requested extent as new one into the tree,
1671 * creating new leaf in the no-space case.
1672 */
1673int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1674 struct ext4_ext_path *path,
1675 struct ext4_extent *newext, int flag)
1676{
1677 struct ext4_extent_header *eh;
1678 struct ext4_extent *ex, *fex;
1679 struct ext4_extent *nearex; /* nearest extent */
1680 struct ext4_ext_path *npath = NULL;
1681 int depth, len, err;
1682 ext4_lblk_t next;
1683 unsigned uninitialized = 0;
1684 int flags = 0;
1685
1686 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1687 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1688 return -EIO;
1689 }
1690 depth = ext_depth(inode);
1691 ex = path[depth].p_ext;
1692 if (unlikely(path[depth].p_hdr == NULL)) {
1693 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1694 return -EIO;
1695 }
1696
1697 /* try to insert block into found extent and return */
1698 if (ex && !(flag & EXT4_GET_BLOCKS_PRE_IO)
1699 && ext4_can_extents_be_merged(inode, ex, newext)) {
1700 ext_debug("append [%d]%d block to %d:[%d]%d (from %llu)\n",
1701 ext4_ext_is_uninitialized(newext),
1702 ext4_ext_get_actual_len(newext),
1703 le32_to_cpu(ex->ee_block),
1704 ext4_ext_is_uninitialized(ex),
1705 ext4_ext_get_actual_len(ex),
1706 ext4_ext_pblock(ex));
1707 err = ext4_ext_get_access(handle, inode, path + depth);
1708 if (err)
1709 return err;
1710
1711 /*
1712 * ext4_can_extents_be_merged should have checked that either
1713 * both extents are uninitialized, or both aren't. Thus we
1714 * need to check only one of them here.
1715 */
1716 if (ext4_ext_is_uninitialized(ex))
1717 uninitialized = 1;
1718 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1719 + ext4_ext_get_actual_len(newext));
1720 if (uninitialized)
1721 ext4_ext_mark_uninitialized(ex);
1722 eh = path[depth].p_hdr;
1723 nearex = ex;
1724 goto merge;
1725 }
1726
1727 depth = ext_depth(inode);
1728 eh = path[depth].p_hdr;
1729 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
1730 goto has_space;
1731
1732 /* probably next leaf has space for us? */
1733 fex = EXT_LAST_EXTENT(eh);
1734 next = EXT_MAX_BLOCKS;
1735 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
1736 next = ext4_ext_next_leaf_block(path);
1737 if (next != EXT_MAX_BLOCKS) {
1738 ext_debug("next leaf block - %d\n", next);
1739 BUG_ON(npath != NULL);
1740 npath = ext4_ext_find_extent(inode, next, NULL);
1741 if (IS_ERR(npath))
1742 return PTR_ERR(npath);
1743 BUG_ON(npath->p_depth != path->p_depth);
1744 eh = npath[depth].p_hdr;
1745 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
1746 ext_debug("next leaf isn't full(%d)\n",
1747 le16_to_cpu(eh->eh_entries));
1748 path = npath;
1749 goto has_space;
1750 }
1751 ext_debug("next leaf has no free space(%d,%d)\n",
1752 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
1753 }
1754
1755 /*
1756 * There is no free space in the found leaf.
1757 * We're gonna add a new leaf in the tree.
1758 */
1759 if (flag & EXT4_GET_BLOCKS_PUNCH_OUT_EXT)
1760 flags = EXT4_MB_USE_ROOT_BLOCKS;
1761 err = ext4_ext_create_new_leaf(handle, inode, flags, path, newext);
1762 if (err)
1763 goto cleanup;
1764 depth = ext_depth(inode);
1765 eh = path[depth].p_hdr;
1766
1767has_space:
1768 nearex = path[depth].p_ext;
1769
1770 err = ext4_ext_get_access(handle, inode, path + depth);
1771 if (err)
1772 goto cleanup;
1773
1774 if (!nearex) {
1775 /* there is no extent in this leaf, create first one */
1776 ext_debug("first extent in the leaf: %d:%llu:[%d]%d\n",
1777 le32_to_cpu(newext->ee_block),
1778 ext4_ext_pblock(newext),
1779 ext4_ext_is_uninitialized(newext),
1780 ext4_ext_get_actual_len(newext));
1781 path[depth].p_ext = EXT_FIRST_EXTENT(eh);
1782 } else if (le32_to_cpu(newext->ee_block)
1783 > le32_to_cpu(nearex->ee_block)) {
1784/* BUG_ON(newext->ee_block == nearex->ee_block); */
1785 if (nearex != EXT_LAST_EXTENT(eh)) {
1786 len = EXT_MAX_EXTENT(eh) - nearex;
1787 len = (len - 1) * sizeof(struct ext4_extent);
1788 len = len < 0 ? 0 : len;
1789 ext_debug("insert %d:%llu:[%d]%d after: nearest 0x%p, "
1790 "move %d from 0x%p to 0x%p\n",
1791 le32_to_cpu(newext->ee_block),
1792 ext4_ext_pblock(newext),
1793 ext4_ext_is_uninitialized(newext),
1794 ext4_ext_get_actual_len(newext),
1795 nearex, len, nearex + 1, nearex + 2);
1796 memmove(nearex + 2, nearex + 1, len);
1797 }
1798 path[depth].p_ext = nearex + 1;
1799 } else {
1800 BUG_ON(newext->ee_block == nearex->ee_block);
1801 len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent);
1802 len = len < 0 ? 0 : len;
1803 ext_debug("insert %d:%llu:[%d]%d before: nearest 0x%p, "
1804 "move %d from 0x%p to 0x%p\n",
1805 le32_to_cpu(newext->ee_block),
1806 ext4_ext_pblock(newext),
1807 ext4_ext_is_uninitialized(newext),
1808 ext4_ext_get_actual_len(newext),
1809 nearex, len, nearex, nearex + 1);
1810 memmove(nearex + 1, nearex, len);
1811 path[depth].p_ext = nearex;
1812 }
1813
1814 le16_add_cpu(&eh->eh_entries, 1);
1815 nearex = path[depth].p_ext;
1816 nearex->ee_block = newext->ee_block;
1817 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
1818 nearex->ee_len = newext->ee_len;
1819
1820merge:
1821 /* try to merge extents to the right */
1822 if (!(flag & EXT4_GET_BLOCKS_PRE_IO))
1823 ext4_ext_try_to_merge(inode, path, nearex);
1824
1825 /* try to merge extents to the left */
1826
1827 /* time to correct all indexes above */
1828 err = ext4_ext_correct_indexes(handle, inode, path);
1829 if (err)
1830 goto cleanup;
1831
1832 err = ext4_ext_dirty(handle, inode, path + depth);
1833
1834cleanup:
1835 if (npath) {
1836 ext4_ext_drop_refs(npath);
1837 kfree(npath);
1838 }
1839 ext4_ext_invalidate_cache(inode);
1840 return err;
1841}
1842
1843static int ext4_ext_walk_space(struct inode *inode, ext4_lblk_t block,
1844 ext4_lblk_t num, ext_prepare_callback func,
1845 void *cbdata)
1846{
1847 struct ext4_ext_path *path = NULL;
1848 struct ext4_ext_cache cbex;
1849 struct ext4_extent *ex;
1850 ext4_lblk_t next, start = 0, end = 0;
1851 ext4_lblk_t last = block + num;
1852 int depth, exists, err = 0;
1853
1854 BUG_ON(func == NULL);
1855 BUG_ON(inode == NULL);
1856
1857 while (block < last && block != EXT_MAX_BLOCKS) {
1858 num = last - block;
1859 /* find extent for this block */
1860 down_read(&EXT4_I(inode)->i_data_sem);
1861 path = ext4_ext_find_extent(inode, block, path);
1862 up_read(&EXT4_I(inode)->i_data_sem);
1863 if (IS_ERR(path)) {
1864 err = PTR_ERR(path);
1865 path = NULL;
1866 break;
1867 }
1868
1869 depth = ext_depth(inode);
1870 if (unlikely(path[depth].p_hdr == NULL)) {
1871 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1872 err = -EIO;
1873 break;
1874 }
1875 ex = path[depth].p_ext;
1876 next = ext4_ext_next_allocated_block(path);
1877
1878 exists = 0;
1879 if (!ex) {
1880 /* there is no extent yet, so try to allocate
1881 * all requested space */
1882 start = block;
1883 end = block + num;
1884 } else if (le32_to_cpu(ex->ee_block) > block) {
1885 /* need to allocate space before found extent */
1886 start = block;
1887 end = le32_to_cpu(ex->ee_block);
1888 if (block + num < end)
1889 end = block + num;
1890 } else if (block >= le32_to_cpu(ex->ee_block)
1891 + ext4_ext_get_actual_len(ex)) {
1892 /* need to allocate space after found extent */
1893 start = block;
1894 end = block + num;
1895 if (end >= next)
1896 end = next;
1897 } else if (block >= le32_to_cpu(ex->ee_block)) {
1898 /*
1899 * some part of requested space is covered
1900 * by found extent
1901 */
1902 start = block;
1903 end = le32_to_cpu(ex->ee_block)
1904 + ext4_ext_get_actual_len(ex);
1905 if (block + num < end)
1906 end = block + num;
1907 exists = 1;
1908 } else {
1909 BUG();
1910 }
1911 BUG_ON(end <= start);
1912
1913 if (!exists) {
1914 cbex.ec_block = start;
1915 cbex.ec_len = end - start;
1916 cbex.ec_start = 0;
1917 } else {
1918 cbex.ec_block = le32_to_cpu(ex->ee_block);
1919 cbex.ec_len = ext4_ext_get_actual_len(ex);
1920 cbex.ec_start = ext4_ext_pblock(ex);
1921 }
1922
1923 if (unlikely(cbex.ec_len == 0)) {
1924 EXT4_ERROR_INODE(inode, "cbex.ec_len == 0");
1925 err = -EIO;
1926 break;
1927 }
1928 err = func(inode, next, &cbex, ex, cbdata);
1929 ext4_ext_drop_refs(path);
1930
1931 if (err < 0)
1932 break;
1933
1934 if (err == EXT_REPEAT)
1935 continue;
1936 else if (err == EXT_BREAK) {
1937 err = 0;
1938 break;
1939 }
1940
1941 if (ext_depth(inode) != depth) {
1942 /* depth was changed. we have to realloc path */
1943 kfree(path);
1944 path = NULL;
1945 }
1946
1947 block = cbex.ec_block + cbex.ec_len;
1948 }
1949
1950 if (path) {
1951 ext4_ext_drop_refs(path);
1952 kfree(path);
1953 }
1954
1955 return err;
1956}
1957
1958static void
1959ext4_ext_put_in_cache(struct inode *inode, ext4_lblk_t block,
1960 __u32 len, ext4_fsblk_t start)
1961{
1962 struct ext4_ext_cache *cex;
1963 BUG_ON(len == 0);
1964 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
1965 cex = &EXT4_I(inode)->i_cached_extent;
1966 cex->ec_block = block;
1967 cex->ec_len = len;
1968 cex->ec_start = start;
1969 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
1970}
1971
1972/*
1973 * ext4_ext_put_gap_in_cache:
1974 * calculate boundaries of the gap that the requested block fits into
1975 * and cache this gap
1976 */
1977static void
1978ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
1979 ext4_lblk_t block)
1980{
1981 int depth = ext_depth(inode);
1982 unsigned long len;
1983 ext4_lblk_t lblock;
1984 struct ext4_extent *ex;
1985
1986 ex = path[depth].p_ext;
1987 if (ex == NULL) {
1988 /* there is no extent yet, so gap is [0;-] */
1989 lblock = 0;
1990 len = EXT_MAX_BLOCKS;
1991 ext_debug("cache gap(whole file):");
1992 } else if (block < le32_to_cpu(ex->ee_block)) {
1993 lblock = block;
1994 len = le32_to_cpu(ex->ee_block) - block;
1995 ext_debug("cache gap(before): %u [%u:%u]",
1996 block,
1997 le32_to_cpu(ex->ee_block),
1998 ext4_ext_get_actual_len(ex));
1999 } else if (block >= le32_to_cpu(ex->ee_block)
2000 + ext4_ext_get_actual_len(ex)) {
2001 ext4_lblk_t next;
2002 lblock = le32_to_cpu(ex->ee_block)
2003 + ext4_ext_get_actual_len(ex);
2004
2005 next = ext4_ext_next_allocated_block(path);
2006 ext_debug("cache gap(after): [%u:%u] %u",
2007 le32_to_cpu(ex->ee_block),
2008 ext4_ext_get_actual_len(ex),
2009 block);
2010 BUG_ON(next == lblock);
2011 len = next - lblock;
2012 } else {
2013 lblock = len = 0;
2014 BUG();
2015 }
2016
2017 ext_debug(" -> %u:%lu\n", lblock, len);
2018 ext4_ext_put_in_cache(inode, lblock, len, 0);
2019}
2020
2021/*
2022 * ext4_ext_check_cache()
2023 * Checks to see if the given block is in the cache.
2024 * If it is, the cached extent is stored in the given
2025 * cache extent pointer. If the cached extent is a hole,
2026 * this routine should be used instead of
2027 * ext4_ext_in_cache if the calling function needs to
2028 * know the size of the hole.
2029 *
2030 * @inode: The files inode
2031 * @block: The block to look for in the cache
2032 * @ex: Pointer where the cached extent will be stored
2033 * if it contains block
2034 *
2035 * Return 0 if cache is invalid; 1 if the cache is valid
2036 */
2037static int ext4_ext_check_cache(struct inode *inode, ext4_lblk_t block,
2038 struct ext4_ext_cache *ex){
2039 struct ext4_ext_cache *cex;
2040 struct ext4_sb_info *sbi;
2041 int ret = 0;
2042
2043 /*
2044 * We borrow i_block_reservation_lock to protect i_cached_extent
2045 */
2046 spin_lock(&EXT4_I(inode)->i_block_reservation_lock);
2047 cex = &EXT4_I(inode)->i_cached_extent;
2048 sbi = EXT4_SB(inode->i_sb);
2049
2050 /* has cache valid data? */
2051 if (cex->ec_len == 0)
2052 goto errout;
2053
2054 if (in_range(block, cex->ec_block, cex->ec_len)) {
2055 memcpy(ex, cex, sizeof(struct ext4_ext_cache));
2056 ext_debug("%u cached by %u:%u:%llu\n",
2057 block,
2058 cex->ec_block, cex->ec_len, cex->ec_start);
2059 ret = 1;
2060 }
2061errout:
2062 if (!ret)
2063 sbi->extent_cache_misses++;
2064 else
2065 sbi->extent_cache_hits++;
2066 spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
2067 return ret;
2068}
2069
2070/*
2071 * ext4_ext_in_cache()
2072 * Checks to see if the given block is in the cache.
2073 * If it is, the cached extent is stored in the given
2074 * extent pointer.
2075 *
2076 * @inode: The files inode
2077 * @block: The block to look for in the cache
2078 * @ex: Pointer where the cached extent will be stored
2079 * if it contains block
2080 *
2081 * Return 0 if cache is invalid; 1 if the cache is valid
2082 */
2083static int
2084ext4_ext_in_cache(struct inode *inode, ext4_lblk_t block,
2085 struct ext4_extent *ex)
2086{
2087 struct ext4_ext_cache cex;
2088 int ret = 0;
2089
2090 if (ext4_ext_check_cache(inode, block, &cex)) {
2091 ex->ee_block = cpu_to_le32(cex.ec_block);
2092 ext4_ext_store_pblock(ex, cex.ec_start);
2093 ex->ee_len = cpu_to_le16(cex.ec_len);
2094 ret = 1;
2095 }
2096
2097 return ret;
2098}
2099
2100
2101/*
2102 * ext4_ext_rm_idx:
2103 * removes index from the index block.
2104 */
2105static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2106 struct ext4_ext_path *path)
2107{
2108 int err;
2109 ext4_fsblk_t leaf;
2110
2111 /* free index block */
2112 path--;
2113 leaf = ext4_idx_pblock(path->p_idx);
2114 if (unlikely(path->p_hdr->eh_entries == 0)) {
2115 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2116 return -EIO;
2117 }
2118 err = ext4_ext_get_access(handle, inode, path);
2119 if (err)
2120 return err;
2121
2122 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2123 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2124 len *= sizeof(struct ext4_extent_idx);
2125 memmove(path->p_idx, path->p_idx + 1, len);
2126 }
2127
2128 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2129 err = ext4_ext_dirty(handle, inode, path);
2130 if (err)
2131 return err;
2132 ext_debug("index is empty, remove it, free block %llu\n", leaf);
2133 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2134 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2135 return err;
2136}
2137
2138/*
2139 * ext4_ext_calc_credits_for_single_extent:
2140 * This routine returns max. credits that needed to insert an extent
2141 * to the extent tree.
2142 * When pass the actual path, the caller should calculate credits
2143 * under i_data_sem.
2144 */
2145int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2146 struct ext4_ext_path *path)
2147{
2148 if (path) {
2149 int depth = ext_depth(inode);
2150 int ret = 0;
2151
2152 /* probably there is space in leaf? */
2153 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2154 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2155
2156 /*
2157 * There are some space in the leaf tree, no
2158 * need to account for leaf block credit
2159 *
2160 * bitmaps and block group descriptor blocks
2161 * and other metadat blocks still need to be
2162 * accounted.
2163 */
2164 /* 1 bitmap, 1 block group descriptor */
2165 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2166 return ret;
2167 }
2168 }
2169
2170 return ext4_chunk_trans_blocks(inode, nrblocks);
2171}
2172
2173/*
2174 * How many index/leaf blocks need to change/allocate to modify nrblocks?
2175 *
2176 * if nrblocks are fit in a single extent (chunk flag is 1), then
2177 * in the worse case, each tree level index/leaf need to be changed
2178 * if the tree split due to insert a new extent, then the old tree
2179 * index/leaf need to be updated too
2180 *
2181 * If the nrblocks are discontiguous, they could cause
2182 * the whole tree split more than once, but this is really rare.
2183 */
2184int ext4_ext_index_trans_blocks(struct inode *inode, int nrblocks, int chunk)
2185{
2186 int index;
2187 int depth = ext_depth(inode);
2188
2189 if (chunk)
2190 index = depth * 2;
2191 else
2192 index = depth * 3;
2193
2194 return index;
2195}
2196
2197static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2198 struct ext4_extent *ex,
2199 ext4_lblk_t from, ext4_lblk_t to)
2200{
2201 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2202 int flags = EXT4_FREE_BLOCKS_FORGET;
2203
2204 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2205 flags |= EXT4_FREE_BLOCKS_METADATA;
2206#ifdef EXTENTS_STATS
2207 {
2208 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2209 spin_lock(&sbi->s_ext_stats_lock);
2210 sbi->s_ext_blocks += ee_len;
2211 sbi->s_ext_extents++;
2212 if (ee_len < sbi->s_ext_min)
2213 sbi->s_ext_min = ee_len;
2214 if (ee_len > sbi->s_ext_max)
2215 sbi->s_ext_max = ee_len;
2216 if (ext_depth(inode) > sbi->s_depth_max)
2217 sbi->s_depth_max = ext_depth(inode);
2218 spin_unlock(&sbi->s_ext_stats_lock);
2219 }
2220#endif
2221 if (from >= le32_to_cpu(ex->ee_block)
2222 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2223 /* tail removal */
2224 ext4_lblk_t num;
2225 ext4_fsblk_t start;
2226
2227 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2228 start = ext4_ext_pblock(ex) + ee_len - num;
2229 ext_debug("free last %u blocks starting %llu\n", num, start);
2230 ext4_free_blocks(handle, inode, NULL, start, num, flags);
2231 } else if (from == le32_to_cpu(ex->ee_block)
2232 && to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
2233 /* head removal */
2234 ext4_lblk_t num;
2235 ext4_fsblk_t start;
2236
2237 num = to - from;
2238 start = ext4_ext_pblock(ex);
2239
2240 ext_debug("free first %u blocks starting %llu\n", num, start);
2241 ext4_free_blocks(handle, inode, 0, start, num, flags);
2242
2243 } else {
2244 printk(KERN_INFO "strange request: removal(2) "
2245 "%u-%u from %u:%u\n",
2246 from, to, le32_to_cpu(ex->ee_block), ee_len);
2247 }
2248 return 0;
2249}
2250
2251
2252/*
2253 * ext4_ext_rm_leaf() Removes the extents associated with the
2254 * blocks appearing between "start" and "end", and splits the extents
2255 * if "start" and "end" appear in the same extent
2256 *
2257 * @handle: The journal handle
2258 * @inode: The files inode
2259 * @path: The path to the leaf
2260 * @start: The first block to remove
2261 * @end: The last block to remove
2262 */
2263static int
2264ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2265 struct ext4_ext_path *path, ext4_lblk_t start,
2266 ext4_lblk_t end)
2267{
2268 int err = 0, correct_index = 0;
2269 int depth = ext_depth(inode), credits;
2270 struct ext4_extent_header *eh;
2271 ext4_lblk_t a, b, block;
2272 unsigned num;
2273 ext4_lblk_t ex_ee_block;
2274 unsigned short ex_ee_len;
2275 unsigned uninitialized = 0;
2276 struct ext4_extent *ex;
2277 struct ext4_map_blocks map;
2278
2279 /* the header must be checked already in ext4_ext_remove_space() */
2280 ext_debug("truncate since %u in leaf\n", start);
2281 if (!path[depth].p_hdr)
2282 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2283 eh = path[depth].p_hdr;
2284 if (unlikely(path[depth].p_hdr == NULL)) {
2285 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2286 return -EIO;
2287 }
2288 /* find where to start removing */
2289 ex = EXT_LAST_EXTENT(eh);
2290
2291 ex_ee_block = le32_to_cpu(ex->ee_block);
2292 ex_ee_len = ext4_ext_get_actual_len(ex);
2293
2294 while (ex >= EXT_FIRST_EXTENT(eh) &&
2295 ex_ee_block + ex_ee_len > start) {
2296
2297 if (ext4_ext_is_uninitialized(ex))
2298 uninitialized = 1;
2299 else
2300 uninitialized = 0;
2301
2302 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2303 uninitialized, ex_ee_len);
2304 path[depth].p_ext = ex;
2305
2306 a = ex_ee_block > start ? ex_ee_block : start;
2307 b = ex_ee_block+ex_ee_len - 1 < end ?
2308 ex_ee_block+ex_ee_len - 1 : end;
2309
2310 ext_debug(" border %u:%u\n", a, b);
2311
2312 /* If this extent is beyond the end of the hole, skip it */
2313 if (end <= ex_ee_block) {
2314 ex--;
2315 ex_ee_block = le32_to_cpu(ex->ee_block);
2316 ex_ee_len = ext4_ext_get_actual_len(ex);
2317 continue;
2318 } else if (a != ex_ee_block &&
2319 b != ex_ee_block + ex_ee_len - 1) {
2320 /*
2321 * If this is a truncate, then this condition should
2322 * never happen because at least one of the end points
2323 * needs to be on the edge of the extent.
2324 */
2325 if (end == EXT_MAX_BLOCKS - 1) {
2326 ext_debug(" bad truncate %u:%u\n",
2327 start, end);
2328 block = 0;
2329 num = 0;
2330 err = -EIO;
2331 goto out;
2332 }
2333 /*
2334 * else this is a hole punch, so the extent needs to
2335 * be split since neither edge of the hole is on the
2336 * extent edge
2337 */
2338 else{
2339 map.m_pblk = ext4_ext_pblock(ex);
2340 map.m_lblk = ex_ee_block;
2341 map.m_len = b - ex_ee_block;
2342
2343 err = ext4_split_extent(handle,
2344 inode, path, &map, 0,
2345 EXT4_GET_BLOCKS_PUNCH_OUT_EXT |
2346 EXT4_GET_BLOCKS_PRE_IO);
2347
2348 if (err < 0)
2349 goto out;
2350
2351 ex_ee_len = ext4_ext_get_actual_len(ex);
2352
2353 b = ex_ee_block+ex_ee_len - 1 < end ?
2354 ex_ee_block+ex_ee_len - 1 : end;
2355
2356 /* Then remove tail of this extent */
2357 block = ex_ee_block;
2358 num = a - block;
2359 }
2360 } else if (a != ex_ee_block) {
2361 /* remove tail of the extent */
2362 block = ex_ee_block;
2363 num = a - block;
2364 } else if (b != ex_ee_block + ex_ee_len - 1) {
2365 /* remove head of the extent */
2366 block = b;
2367 num = ex_ee_block + ex_ee_len - b;
2368
2369 /*
2370 * If this is a truncate, this condition
2371 * should never happen
2372 */
2373 if (end == EXT_MAX_BLOCKS - 1) {
2374 ext_debug(" bad truncate %u:%u\n",
2375 start, end);
2376 err = -EIO;
2377 goto out;
2378 }
2379 } else {
2380 /* remove whole extent: excellent! */
2381 block = ex_ee_block;
2382 num = 0;
2383 if (a != ex_ee_block) {
2384 ext_debug(" bad truncate %u:%u\n",
2385 start, end);
2386 err = -EIO;
2387 goto out;
2388 }
2389
2390 if (b != ex_ee_block + ex_ee_len - 1) {
2391 ext_debug(" bad truncate %u:%u\n",
2392 start, end);
2393 err = -EIO;
2394 goto out;
2395 }
2396 }
2397
2398 /*
2399 * 3 for leaf, sb, and inode plus 2 (bmap and group
2400 * descriptor) for each block group; assume two block
2401 * groups plus ex_ee_len/blocks_per_block_group for
2402 * the worst case
2403 */
2404 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2405 if (ex == EXT_FIRST_EXTENT(eh)) {
2406 correct_index = 1;
2407 credits += (ext_depth(inode)) + 1;
2408 }
2409 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2410
2411 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2412 if (err)
2413 goto out;
2414
2415 err = ext4_ext_get_access(handle, inode, path + depth);
2416 if (err)
2417 goto out;
2418
2419 err = ext4_remove_blocks(handle, inode, ex, a, b);
2420 if (err)
2421 goto out;
2422
2423 if (num == 0) {
2424 /* this extent is removed; mark slot entirely unused */
2425 ext4_ext_store_pblock(ex, 0);
2426 } else if (block != ex_ee_block) {
2427 /*
2428 * If this was a head removal, then we need to update
2429 * the physical block since it is now at a different
2430 * location
2431 */
2432 ext4_ext_store_pblock(ex, ext4_ext_pblock(ex) + (b-a));
2433 }
2434
2435 ex->ee_block = cpu_to_le32(block);
2436 ex->ee_len = cpu_to_le16(num);
2437 /*
2438 * Do not mark uninitialized if all the blocks in the
2439 * extent have been removed.
2440 */
2441 if (uninitialized && num)
2442 ext4_ext_mark_uninitialized(ex);
2443
2444 err = ext4_ext_dirty(handle, inode, path + depth);
2445 if (err)
2446 goto out;
2447
2448 /*
2449 * If the extent was completely released,
2450 * we need to remove it from the leaf
2451 */
2452 if (num == 0) {
2453 if (end != EXT_MAX_BLOCKS - 1) {
2454 /*
2455 * For hole punching, we need to scoot all the
2456 * extents up when an extent is removed so that
2457 * we dont have blank extents in the middle
2458 */
2459 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2460 sizeof(struct ext4_extent));
2461
2462 /* Now get rid of the one at the end */
2463 memset(EXT_LAST_EXTENT(eh), 0,
2464 sizeof(struct ext4_extent));
2465 }
2466 le16_add_cpu(&eh->eh_entries, -1);
2467 }
2468
2469 ext_debug("new extent: %u:%u:%llu\n", block, num,
2470 ext4_ext_pblock(ex));
2471 ex--;
2472 ex_ee_block = le32_to_cpu(ex->ee_block);
2473 ex_ee_len = ext4_ext_get_actual_len(ex);
2474 }
2475
2476 if (correct_index && eh->eh_entries)
2477 err = ext4_ext_correct_indexes(handle, inode, path);
2478
2479 /* if this leaf is free, then we should
2480 * remove it from index block above */
2481 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2482 err = ext4_ext_rm_idx(handle, inode, path + depth);
2483
2484out:
2485 return err;
2486}
2487
2488/*
2489 * ext4_ext_more_to_rm:
2490 * returns 1 if current index has to be freed (even partial)
2491 */
2492static int
2493ext4_ext_more_to_rm(struct ext4_ext_path *path)
2494{
2495 BUG_ON(path->p_idx == NULL);
2496
2497 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2498 return 0;
2499
2500 /*
2501 * if truncate on deeper level happened, it wasn't partial,
2502 * so we have to consider current index for truncation
2503 */
2504 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2505 return 0;
2506 return 1;
2507}
2508
2509static int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start)
2510{
2511 struct super_block *sb = inode->i_sb;
2512 int depth = ext_depth(inode);
2513 struct ext4_ext_path *path;
2514 handle_t *handle;
2515 int i, err;
2516
2517 ext_debug("truncate since %u\n", start);
2518
2519 /* probably first extent we're gonna free will be last in block */
2520 handle = ext4_journal_start(inode, depth + 1);
2521 if (IS_ERR(handle))
2522 return PTR_ERR(handle);
2523
2524again:
2525 ext4_ext_invalidate_cache(inode);
2526
2527 /*
2528 * We start scanning from right side, freeing all the blocks
2529 * after i_size and walking into the tree depth-wise.
2530 */
2531 depth = ext_depth(inode);
2532 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_NOFS);
2533 if (path == NULL) {
2534 ext4_journal_stop(handle);
2535 return -ENOMEM;
2536 }
2537 path[0].p_depth = depth;
2538 path[0].p_hdr = ext_inode_hdr(inode);
2539 if (ext4_ext_check(inode, path[0].p_hdr, depth)) {
2540 err = -EIO;
2541 goto out;
2542 }
2543 i = err = 0;
2544
2545 while (i >= 0 && err == 0) {
2546 if (i == depth) {
2547 /* this is leaf block */
2548 err = ext4_ext_rm_leaf(handle, inode, path,
2549 start, EXT_MAX_BLOCKS - 1);
2550 /* root level has p_bh == NULL, brelse() eats this */
2551 brelse(path[i].p_bh);
2552 path[i].p_bh = NULL;
2553 i--;
2554 continue;
2555 }
2556
2557 /* this is index block */
2558 if (!path[i].p_hdr) {
2559 ext_debug("initialize header\n");
2560 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2561 }
2562
2563 if (!path[i].p_idx) {
2564 /* this level hasn't been touched yet */
2565 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2566 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2567 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2568 path[i].p_hdr,
2569 le16_to_cpu(path[i].p_hdr->eh_entries));
2570 } else {
2571 /* we were already here, see at next index */
2572 path[i].p_idx--;
2573 }
2574
2575 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2576 i, EXT_FIRST_INDEX(path[i].p_hdr),
2577 path[i].p_idx);
2578 if (ext4_ext_more_to_rm(path + i)) {
2579 struct buffer_head *bh;
2580 /* go to the next level */
2581 ext_debug("move to level %d (block %llu)\n",
2582 i + 1, ext4_idx_pblock(path[i].p_idx));
2583 memset(path + i + 1, 0, sizeof(*path));
2584 bh = sb_bread(sb, ext4_idx_pblock(path[i].p_idx));
2585 if (!bh) {
2586 /* should we reset i_size? */
2587 err = -EIO;
2588 break;
2589 }
2590 if (WARN_ON(i + 1 > depth)) {
2591 err = -EIO;
2592 break;
2593 }
2594 if (ext4_ext_check(inode, ext_block_hdr(bh),
2595 depth - i - 1)) {
2596 err = -EIO;
2597 break;
2598 }
2599 path[i + 1].p_bh = bh;
2600
2601 /* save actual number of indexes since this
2602 * number is changed at the next iteration */
2603 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2604 i++;
2605 } else {
2606 /* we finished processing this index, go up */
2607 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2608 /* index is empty, remove it;
2609 * handle must be already prepared by the
2610 * truncatei_leaf() */
2611 err = ext4_ext_rm_idx(handle, inode, path + i);
2612 }
2613 /* root level has p_bh == NULL, brelse() eats this */
2614 brelse(path[i].p_bh);
2615 path[i].p_bh = NULL;
2616 i--;
2617 ext_debug("return to level %d\n", i);
2618 }
2619 }
2620
2621 /* TODO: flexible tree reduction should be here */
2622 if (path->p_hdr->eh_entries == 0) {
2623 /*
2624 * truncate to zero freed all the tree,
2625 * so we need to correct eh_depth
2626 */
2627 err = ext4_ext_get_access(handle, inode, path);
2628 if (err == 0) {
2629 ext_inode_hdr(inode)->eh_depth = 0;
2630 ext_inode_hdr(inode)->eh_max =
2631 cpu_to_le16(ext4_ext_space_root(inode, 0));
2632 err = ext4_ext_dirty(handle, inode, path);
2633 }
2634 }
2635out:
2636 ext4_ext_drop_refs(path);
2637 kfree(path);
2638 if (err == -EAGAIN)
2639 goto again;
2640 ext4_journal_stop(handle);
2641
2642 return err;
2643}
2644
2645/*
2646 * called at mount time
2647 */
2648void ext4_ext_init(struct super_block *sb)
2649{
2650 /*
2651 * possible initialization would be here
2652 */
2653
2654 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
2655#if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
2656 printk(KERN_INFO "EXT4-fs: file extents enabled");
2657#ifdef AGGRESSIVE_TEST
2658 printk(", aggressive tests");
2659#endif
2660#ifdef CHECK_BINSEARCH
2661 printk(", check binsearch");
2662#endif
2663#ifdef EXTENTS_STATS
2664 printk(", stats");
2665#endif
2666 printk("\n");
2667#endif
2668#ifdef EXTENTS_STATS
2669 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
2670 EXT4_SB(sb)->s_ext_min = 1 << 30;
2671 EXT4_SB(sb)->s_ext_max = 0;
2672#endif
2673 }
2674}
2675
2676/*
2677 * called at umount time
2678 */
2679void ext4_ext_release(struct super_block *sb)
2680{
2681 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
2682 return;
2683
2684#ifdef EXTENTS_STATS
2685 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
2686 struct ext4_sb_info *sbi = EXT4_SB(sb);
2687 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
2688 sbi->s_ext_blocks, sbi->s_ext_extents,
2689 sbi->s_ext_blocks / sbi->s_ext_extents);
2690 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
2691 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
2692 }
2693#endif
2694}
2695
2696/* FIXME!! we need to try to merge to left or right after zero-out */
2697static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
2698{
2699 ext4_fsblk_t ee_pblock;
2700 unsigned int ee_len;
2701 int ret;
2702
2703 ee_len = ext4_ext_get_actual_len(ex);
2704 ee_pblock = ext4_ext_pblock(ex);
2705
2706 ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
2707 if (ret > 0)
2708 ret = 0;
2709
2710 return ret;
2711}
2712
2713/*
2714 * used by extent splitting.
2715 */
2716#define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
2717 due to ENOSPC */
2718#define EXT4_EXT_MARK_UNINIT1 0x2 /* mark first half uninitialized */
2719#define EXT4_EXT_MARK_UNINIT2 0x4 /* mark second half uninitialized */
2720
2721/*
2722 * ext4_split_extent_at() splits an extent at given block.
2723 *
2724 * @handle: the journal handle
2725 * @inode: the file inode
2726 * @path: the path to the extent
2727 * @split: the logical block where the extent is splitted.
2728 * @split_flags: indicates if the extent could be zeroout if split fails, and
2729 * the states(init or uninit) of new extents.
2730 * @flags: flags used to insert new extent to extent tree.
2731 *
2732 *
2733 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
2734 * of which are deterimined by split_flag.
2735 *
2736 * There are two cases:
2737 * a> the extent are splitted into two extent.
2738 * b> split is not needed, and just mark the extent.
2739 *
2740 * return 0 on success.
2741 */
2742static int ext4_split_extent_at(handle_t *handle,
2743 struct inode *inode,
2744 struct ext4_ext_path *path,
2745 ext4_lblk_t split,
2746 int split_flag,
2747 int flags)
2748{
2749 ext4_fsblk_t newblock;
2750 ext4_lblk_t ee_block;
2751 struct ext4_extent *ex, newex, orig_ex;
2752 struct ext4_extent *ex2 = NULL;
2753 unsigned int ee_len, depth;
2754 int err = 0;
2755
2756 ext_debug("ext4_split_extents_at: inode %lu, logical"
2757 "block %llu\n", inode->i_ino, (unsigned long long)split);
2758
2759 ext4_ext_show_leaf(inode, path);
2760
2761 depth = ext_depth(inode);
2762 ex = path[depth].p_ext;
2763 ee_block = le32_to_cpu(ex->ee_block);
2764 ee_len = ext4_ext_get_actual_len(ex);
2765 newblock = split - ee_block + ext4_ext_pblock(ex);
2766
2767 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
2768
2769 err = ext4_ext_get_access(handle, inode, path + depth);
2770 if (err)
2771 goto out;
2772
2773 if (split == ee_block) {
2774 /*
2775 * case b: block @split is the block that the extent begins with
2776 * then we just change the state of the extent, and splitting
2777 * is not needed.
2778 */
2779 if (split_flag & EXT4_EXT_MARK_UNINIT2)
2780 ext4_ext_mark_uninitialized(ex);
2781 else
2782 ext4_ext_mark_initialized(ex);
2783
2784 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
2785 ext4_ext_try_to_merge(inode, path, ex);
2786
2787 err = ext4_ext_dirty(handle, inode, path + depth);
2788 goto out;
2789 }
2790
2791 /* case a */
2792 memcpy(&orig_ex, ex, sizeof(orig_ex));
2793 ex->ee_len = cpu_to_le16(split - ee_block);
2794 if (split_flag & EXT4_EXT_MARK_UNINIT1)
2795 ext4_ext_mark_uninitialized(ex);
2796
2797 /*
2798 * path may lead to new leaf, not to original leaf any more
2799 * after ext4_ext_insert_extent() returns,
2800 */
2801 err = ext4_ext_dirty(handle, inode, path + depth);
2802 if (err)
2803 goto fix_extent_len;
2804
2805 ex2 = &newex;
2806 ex2->ee_block = cpu_to_le32(split);
2807 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
2808 ext4_ext_store_pblock(ex2, newblock);
2809 if (split_flag & EXT4_EXT_MARK_UNINIT2)
2810 ext4_ext_mark_uninitialized(ex2);
2811
2812 err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
2813 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
2814 err = ext4_ext_zeroout(inode, &orig_ex);
2815 if (err)
2816 goto fix_extent_len;
2817 /* update the extent length and mark as initialized */
2818 ex->ee_len = cpu_to_le32(ee_len);
2819 ext4_ext_try_to_merge(inode, path, ex);
2820 err = ext4_ext_dirty(handle, inode, path + depth);
2821 goto out;
2822 } else if (err)
2823 goto fix_extent_len;
2824
2825out:
2826 ext4_ext_show_leaf(inode, path);
2827 return err;
2828
2829fix_extent_len:
2830 ex->ee_len = orig_ex.ee_len;
2831 ext4_ext_dirty(handle, inode, path + depth);
2832 return err;
2833}
2834
2835/*
2836 * ext4_split_extents() splits an extent and mark extent which is covered
2837 * by @map as split_flags indicates
2838 *
2839 * It may result in splitting the extent into multiple extents (upto three)
2840 * There are three possibilities:
2841 * a> There is no split required
2842 * b> Splits in two extents: Split is happening at either end of the extent
2843 * c> Splits in three extents: Somone is splitting in middle of the extent
2844 *
2845 */
2846static int ext4_split_extent(handle_t *handle,
2847 struct inode *inode,
2848 struct ext4_ext_path *path,
2849 struct ext4_map_blocks *map,
2850 int split_flag,
2851 int flags)
2852{
2853 ext4_lblk_t ee_block;
2854 struct ext4_extent *ex;
2855 unsigned int ee_len, depth;
2856 int err = 0;
2857 int uninitialized;
2858 int split_flag1, flags1;
2859
2860 depth = ext_depth(inode);
2861 ex = path[depth].p_ext;
2862 ee_block = le32_to_cpu(ex->ee_block);
2863 ee_len = ext4_ext_get_actual_len(ex);
2864 uninitialized = ext4_ext_is_uninitialized(ex);
2865
2866 if (map->m_lblk + map->m_len < ee_block + ee_len) {
2867 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT ?
2868 EXT4_EXT_MAY_ZEROOUT : 0;
2869 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
2870 if (uninitialized)
2871 split_flag1 |= EXT4_EXT_MARK_UNINIT1 |
2872 EXT4_EXT_MARK_UNINIT2;
2873 err = ext4_split_extent_at(handle, inode, path,
2874 map->m_lblk + map->m_len, split_flag1, flags1);
2875 if (err)
2876 goto out;
2877 }
2878
2879 ext4_ext_drop_refs(path);
2880 path = ext4_ext_find_extent(inode, map->m_lblk, path);
2881 if (IS_ERR(path))
2882 return PTR_ERR(path);
2883
2884 if (map->m_lblk >= ee_block) {
2885 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT ?
2886 EXT4_EXT_MAY_ZEROOUT : 0;
2887 if (uninitialized)
2888 split_flag1 |= EXT4_EXT_MARK_UNINIT1;
2889 if (split_flag & EXT4_EXT_MARK_UNINIT2)
2890 split_flag1 |= EXT4_EXT_MARK_UNINIT2;
2891 err = ext4_split_extent_at(handle, inode, path,
2892 map->m_lblk, split_flag1, flags);
2893 if (err)
2894 goto out;
2895 }
2896
2897 ext4_ext_show_leaf(inode, path);
2898out:
2899 return err ? err : map->m_len;
2900}
2901
2902#define EXT4_EXT_ZERO_LEN 7
2903/*
2904 * This function is called by ext4_ext_map_blocks() if someone tries to write
2905 * to an uninitialized extent. It may result in splitting the uninitialized
2906 * extent into multiple extents (up to three - one initialized and two
2907 * uninitialized).
2908 * There are three possibilities:
2909 * a> There is no split required: Entire extent should be initialized
2910 * b> Splits in two extents: Write is happening at either end of the extent
2911 * c> Splits in three extents: Somone is writing in middle of the extent
2912 */
2913static int ext4_ext_convert_to_initialized(handle_t *handle,
2914 struct inode *inode,
2915 struct ext4_map_blocks *map,
2916 struct ext4_ext_path *path)
2917{
2918 struct ext4_map_blocks split_map;
2919 struct ext4_extent zero_ex;
2920 struct ext4_extent *ex;
2921 ext4_lblk_t ee_block, eof_block;
2922 unsigned int allocated, ee_len, depth;
2923 int err = 0;
2924 int split_flag = 0;
2925
2926 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
2927 "block %llu, max_blocks %u\n", inode->i_ino,
2928 (unsigned long long)map->m_lblk, map->m_len);
2929
2930 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
2931 inode->i_sb->s_blocksize_bits;
2932 if (eof_block < map->m_lblk + map->m_len)
2933 eof_block = map->m_lblk + map->m_len;
2934
2935 depth = ext_depth(inode);
2936 ex = path[depth].p_ext;
2937 ee_block = le32_to_cpu(ex->ee_block);
2938 ee_len = ext4_ext_get_actual_len(ex);
2939 allocated = ee_len - (map->m_lblk - ee_block);
2940
2941 WARN_ON(map->m_lblk < ee_block);
2942 /*
2943 * It is safe to convert extent to initialized via explicit
2944 * zeroout only if extent is fully insde i_size or new_size.
2945 */
2946 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
2947
2948 /* If extent has less than 2*EXT4_EXT_ZERO_LEN zerout directly */
2949 if (ee_len <= 2*EXT4_EXT_ZERO_LEN &&
2950 (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
2951 err = ext4_ext_zeroout(inode, ex);
2952 if (err)
2953 goto out;
2954
2955 err = ext4_ext_get_access(handle, inode, path + depth);
2956 if (err)
2957 goto out;
2958 ext4_ext_mark_initialized(ex);
2959 ext4_ext_try_to_merge(inode, path, ex);
2960 err = ext4_ext_dirty(handle, inode, path + depth);
2961 goto out;
2962 }
2963
2964 /*
2965 * four cases:
2966 * 1. split the extent into three extents.
2967 * 2. split the extent into two extents, zeroout the first half.
2968 * 3. split the extent into two extents, zeroout the second half.
2969 * 4. split the extent into two extents with out zeroout.
2970 */
2971 split_map.m_lblk = map->m_lblk;
2972 split_map.m_len = map->m_len;
2973
2974 if (allocated > map->m_len) {
2975 if (allocated <= EXT4_EXT_ZERO_LEN &&
2976 (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
2977 /* case 3 */
2978 zero_ex.ee_block =
2979 cpu_to_le32(map->m_lblk);
2980 zero_ex.ee_len = cpu_to_le16(allocated);
2981 ext4_ext_store_pblock(&zero_ex,
2982 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
2983 err = ext4_ext_zeroout(inode, &zero_ex);
2984 if (err)
2985 goto out;
2986 split_map.m_lblk = map->m_lblk;
2987 split_map.m_len = allocated;
2988 } else if ((map->m_lblk - ee_block + map->m_len <
2989 EXT4_EXT_ZERO_LEN) &&
2990 (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
2991 /* case 2 */
2992 if (map->m_lblk != ee_block) {
2993 zero_ex.ee_block = ex->ee_block;
2994 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
2995 ee_block);
2996 ext4_ext_store_pblock(&zero_ex,
2997 ext4_ext_pblock(ex));
2998 err = ext4_ext_zeroout(inode, &zero_ex);
2999 if (err)
3000 goto out;
3001 }
3002
3003 split_map.m_lblk = ee_block;
3004 split_map.m_len = map->m_lblk - ee_block + map->m_len;
3005 allocated = map->m_len;
3006 }
3007 }
3008
3009 allocated = ext4_split_extent(handle, inode, path,
3010 &split_map, split_flag, 0);
3011 if (allocated < 0)
3012 err = allocated;
3013
3014out:
3015 return err ? err : allocated;
3016}
3017
3018/*
3019 * This function is called by ext4_ext_map_blocks() from
3020 * ext4_get_blocks_dio_write() when DIO to write
3021 * to an uninitialized extent.
3022 *
3023 * Writing to an uninitialized extent may result in splitting the uninitialized
3024 * extent into multiple /initialized uninitialized extents (up to three)
3025 * There are three possibilities:
3026 * a> There is no split required: Entire extent should be uninitialized
3027 * b> Splits in two extents: Write is happening at either end of the extent
3028 * c> Splits in three extents: Somone is writing in middle of the extent
3029 *
3030 * One of more index blocks maybe needed if the extent tree grow after
3031 * the uninitialized extent split. To prevent ENOSPC occur at the IO
3032 * complete, we need to split the uninitialized extent before DIO submit
3033 * the IO. The uninitialized extent called at this time will be split
3034 * into three uninitialized extent(at most). After IO complete, the part
3035 * being filled will be convert to initialized by the end_io callback function
3036 * via ext4_convert_unwritten_extents().
3037 *
3038 * Returns the size of uninitialized extent to be written on success.
3039 */
3040static int ext4_split_unwritten_extents(handle_t *handle,
3041 struct inode *inode,
3042 struct ext4_map_blocks *map,
3043 struct ext4_ext_path *path,
3044 int flags)
3045{
3046 ext4_lblk_t eof_block;
3047 ext4_lblk_t ee_block;
3048 struct ext4_extent *ex;
3049 unsigned int ee_len;
3050 int split_flag = 0, depth;
3051
3052 ext_debug("ext4_split_unwritten_extents: inode %lu, logical"
3053 "block %llu, max_blocks %u\n", inode->i_ino,
3054 (unsigned long long)map->m_lblk, map->m_len);
3055
3056 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3057 inode->i_sb->s_blocksize_bits;
3058 if (eof_block < map->m_lblk + map->m_len)
3059 eof_block = map->m_lblk + map->m_len;
3060 /*
3061 * It is safe to convert extent to initialized via explicit
3062 * zeroout only if extent is fully insde i_size or new_size.
3063 */
3064 depth = ext_depth(inode);
3065 ex = path[depth].p_ext;
3066 ee_block = le32_to_cpu(ex->ee_block);
3067 ee_len = ext4_ext_get_actual_len(ex);
3068
3069 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3070 split_flag |= EXT4_EXT_MARK_UNINIT2;
3071
3072 flags |= EXT4_GET_BLOCKS_PRE_IO;
3073 return ext4_split_extent(handle, inode, path, map, split_flag, flags);
3074}
3075
3076static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3077 struct inode *inode,
3078 struct ext4_ext_path *path)
3079{
3080 struct ext4_extent *ex;
3081 int depth;
3082 int err = 0;
3083
3084 depth = ext_depth(inode);
3085 ex = path[depth].p_ext;
3086
3087 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3088 "block %llu, max_blocks %u\n", inode->i_ino,
3089 (unsigned long long)le32_to_cpu(ex->ee_block),
3090 ext4_ext_get_actual_len(ex));
3091
3092 err = ext4_ext_get_access(handle, inode, path + depth);
3093 if (err)
3094 goto out;
3095 /* first mark the extent as initialized */
3096 ext4_ext_mark_initialized(ex);
3097
3098 /* note: ext4_ext_correct_indexes() isn't needed here because
3099 * borders are not changed
3100 */
3101 ext4_ext_try_to_merge(inode, path, ex);
3102
3103 /* Mark modified extent as dirty */
3104 err = ext4_ext_dirty(handle, inode, path + depth);
3105out:
3106 ext4_ext_show_leaf(inode, path);
3107 return err;
3108}
3109
3110static void unmap_underlying_metadata_blocks(struct block_device *bdev,
3111 sector_t block, int count)
3112{
3113 int i;
3114 for (i = 0; i < count; i++)
3115 unmap_underlying_metadata(bdev, block + i);
3116}
3117
3118/*
3119 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3120 */
3121static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3122 ext4_lblk_t lblk,
3123 struct ext4_ext_path *path,
3124 unsigned int len)
3125{
3126 int i, depth;
3127 struct ext4_extent_header *eh;
3128 struct ext4_extent *last_ex;
3129
3130 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3131 return 0;
3132
3133 depth = ext_depth(inode);
3134 eh = path[depth].p_hdr;
3135
3136 if (unlikely(!eh->eh_entries)) {
3137 EXT4_ERROR_INODE(inode, "eh->eh_entries == 0 and "
3138 "EOFBLOCKS_FL set");
3139 return -EIO;
3140 }
3141 last_ex = EXT_LAST_EXTENT(eh);
3142 /*
3143 * We should clear the EOFBLOCKS_FL flag if we are writing the
3144 * last block in the last extent in the file. We test this by
3145 * first checking to see if the caller to
3146 * ext4_ext_get_blocks() was interested in the last block (or
3147 * a block beyond the last block) in the current extent. If
3148 * this turns out to be false, we can bail out from this
3149 * function immediately.
3150 */
3151 if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3152 ext4_ext_get_actual_len(last_ex))
3153 return 0;
3154 /*
3155 * If the caller does appear to be planning to write at or
3156 * beyond the end of the current extent, we then test to see
3157 * if the current extent is the last extent in the file, by
3158 * checking to make sure it was reached via the rightmost node
3159 * at each level of the tree.
3160 */
3161 for (i = depth-1; i >= 0; i--)
3162 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3163 return 0;
3164 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3165 return ext4_mark_inode_dirty(handle, inode);
3166}
3167
3168static int
3169ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
3170 struct ext4_map_blocks *map,
3171 struct ext4_ext_path *path, int flags,
3172 unsigned int allocated, ext4_fsblk_t newblock)
3173{
3174 int ret = 0;
3175 int err = 0;
3176 ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
3177
3178 ext_debug("ext4_ext_handle_uninitialized_extents: inode %lu, logical"
3179 "block %llu, max_blocks %u, flags %d, allocated %u",
3180 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
3181 flags, allocated);
3182 ext4_ext_show_leaf(inode, path);
3183
3184 /* get_block() before submit the IO, split the extent */
3185 if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
3186 ret = ext4_split_unwritten_extents(handle, inode, map,
3187 path, flags);
3188 /*
3189 * Flag the inode(non aio case) or end_io struct (aio case)
3190 * that this IO needs to conversion to written when IO is
3191 * completed
3192 */
3193 if (io && !(io->flag & EXT4_IO_END_UNWRITTEN)) {
3194 io->flag = EXT4_IO_END_UNWRITTEN;
3195 atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
3196 } else
3197 ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
3198 if (ext4_should_dioread_nolock(inode))
3199 map->m_flags |= EXT4_MAP_UNINIT;
3200 goto out;
3201 }
3202 /* IO end_io complete, convert the filled extent to written */
3203 if ((flags & EXT4_GET_BLOCKS_CONVERT)) {
3204 ret = ext4_convert_unwritten_extents_endio(handle, inode,
3205 path);
3206 if (ret >= 0) {
3207 ext4_update_inode_fsync_trans(handle, inode, 1);
3208 err = check_eofblocks_fl(handle, inode, map->m_lblk,
3209 path, map->m_len);
3210 } else
3211 err = ret;
3212 goto out2;
3213 }
3214 /* buffered IO case */
3215 /*
3216 * repeat fallocate creation request
3217 * we already have an unwritten extent
3218 */
3219 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT)
3220 goto map_out;
3221
3222 /* buffered READ or buffered write_begin() lookup */
3223 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3224 /*
3225 * We have blocks reserved already. We
3226 * return allocated blocks so that delalloc
3227 * won't do block reservation for us. But
3228 * the buffer head will be unmapped so that
3229 * a read from the block returns 0s.
3230 */
3231 map->m_flags |= EXT4_MAP_UNWRITTEN;
3232 goto out1;
3233 }
3234
3235 /* buffered write, writepage time, convert*/
3236 ret = ext4_ext_convert_to_initialized(handle, inode, map, path);
3237 if (ret >= 0) {
3238 ext4_update_inode_fsync_trans(handle, inode, 1);
3239 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
3240 map->m_len);
3241 if (err < 0)
3242 goto out2;
3243 }
3244
3245out:
3246 if (ret <= 0) {
3247 err = ret;
3248 goto out2;
3249 } else
3250 allocated = ret;
3251 map->m_flags |= EXT4_MAP_NEW;
3252 /*
3253 * if we allocated more blocks than requested
3254 * we need to make sure we unmap the extra block
3255 * allocated. The actual needed block will get
3256 * unmapped later when we find the buffer_head marked
3257 * new.
3258 */
3259 if (allocated > map->m_len) {
3260 unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
3261 newblock + map->m_len,
3262 allocated - map->m_len);
3263 allocated = map->m_len;
3264 }
3265
3266 /*
3267 * If we have done fallocate with the offset that is already
3268 * delayed allocated, we would have block reservation
3269 * and quota reservation done in the delayed write path.
3270 * But fallocate would have already updated quota and block
3271 * count for this offset. So cancel these reservation
3272 */
3273 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
3274 ext4_da_update_reserve_space(inode, allocated, 0);
3275
3276map_out:
3277 map->m_flags |= EXT4_MAP_MAPPED;
3278out1:
3279 if (allocated > map->m_len)
3280 allocated = map->m_len;
3281 ext4_ext_show_leaf(inode, path);
3282 map->m_pblk = newblock;
3283 map->m_len = allocated;
3284out2:
3285 if (path) {
3286 ext4_ext_drop_refs(path);
3287 kfree(path);
3288 }
3289 return err ? err : allocated;
3290}
3291
3292/*
3293 * Block allocation/map/preallocation routine for extents based files
3294 *
3295 *
3296 * Need to be called with
3297 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
3298 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
3299 *
3300 * return > 0, number of of blocks already mapped/allocated
3301 * if create == 0 and these are pre-allocated blocks
3302 * buffer head is unmapped
3303 * otherwise blocks are mapped
3304 *
3305 * return = 0, if plain look up failed (blocks have not been allocated)
3306 * buffer head is unmapped
3307 *
3308 * return < 0, error case.
3309 */
3310int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
3311 struct ext4_map_blocks *map, int flags)
3312{
3313 struct ext4_ext_path *path = NULL;
3314 struct ext4_extent newex, *ex;
3315 ext4_fsblk_t newblock = 0;
3316 int err = 0, depth, ret;
3317 unsigned int allocated = 0;
3318 unsigned int punched_out = 0;
3319 unsigned int result = 0;
3320 struct ext4_allocation_request ar;
3321 ext4_io_end_t *io = EXT4_I(inode)->cur_aio_dio;
3322 struct ext4_map_blocks punch_map;
3323
3324 ext_debug("blocks %u/%u requested for inode %lu\n",
3325 map->m_lblk, map->m_len, inode->i_ino);
3326 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
3327
3328 /* check in cache */
3329 if (!(flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) &&
3330 ext4_ext_in_cache(inode, map->m_lblk, &newex)) {
3331 if (!newex.ee_start_lo && !newex.ee_start_hi) {
3332 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3333 /*
3334 * block isn't allocated yet and
3335 * user doesn't want to allocate it
3336 */
3337 goto out2;
3338 }
3339 /* we should allocate requested block */
3340 } else {
3341 /* block is already allocated */
3342 newblock = map->m_lblk
3343 - le32_to_cpu(newex.ee_block)
3344 + ext4_ext_pblock(&newex);
3345 /* number of remaining blocks in the extent */
3346 allocated = ext4_ext_get_actual_len(&newex) -
3347 (map->m_lblk - le32_to_cpu(newex.ee_block));
3348 goto out;
3349 }
3350 }
3351
3352 /* find extent for this block */
3353 path = ext4_ext_find_extent(inode, map->m_lblk, NULL);
3354 if (IS_ERR(path)) {
3355 err = PTR_ERR(path);
3356 path = NULL;
3357 goto out2;
3358 }
3359
3360 depth = ext_depth(inode);
3361
3362 /*
3363 * consistent leaf must not be empty;
3364 * this situation is possible, though, _during_ tree modification;
3365 * this is why assert can't be put in ext4_ext_find_extent()
3366 */
3367 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
3368 EXT4_ERROR_INODE(inode, "bad extent address "
3369 "lblock: %lu, depth: %d pblock %lld",
3370 (unsigned long) map->m_lblk, depth,
3371 path[depth].p_block);
3372 err = -EIO;
3373 goto out2;
3374 }
3375
3376 ex = path[depth].p_ext;
3377 if (ex) {
3378 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
3379 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
3380 unsigned short ee_len;
3381
3382 /*
3383 * Uninitialized extents are treated as holes, except that
3384 * we split out initialized portions during a write.
3385 */
3386 ee_len = ext4_ext_get_actual_len(ex);
3387 /* if found extent covers block, simply return it */
3388 if (in_range(map->m_lblk, ee_block, ee_len)) {
3389 newblock = map->m_lblk - ee_block + ee_start;
3390 /* number of remaining blocks in the extent */
3391 allocated = ee_len - (map->m_lblk - ee_block);
3392 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
3393 ee_block, ee_len, newblock);
3394
3395 if ((flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) == 0) {
3396 /*
3397 * Do not put uninitialized extent
3398 * in the cache
3399 */
3400 if (!ext4_ext_is_uninitialized(ex)) {
3401 ext4_ext_put_in_cache(inode, ee_block,
3402 ee_len, ee_start);
3403 goto out;
3404 }
3405 ret = ext4_ext_handle_uninitialized_extents(
3406 handle, inode, map, path, flags,
3407 allocated, newblock);
3408 return ret;
3409 }
3410
3411 /*
3412 * Punch out the map length, but only to the
3413 * end of the extent
3414 */
3415 punched_out = allocated < map->m_len ?
3416 allocated : map->m_len;
3417
3418 /*
3419 * Sense extents need to be converted to
3420 * uninitialized, they must fit in an
3421 * uninitialized extent
3422 */
3423 if (punched_out > EXT_UNINIT_MAX_LEN)
3424 punched_out = EXT_UNINIT_MAX_LEN;
3425
3426 punch_map.m_lblk = map->m_lblk;
3427 punch_map.m_pblk = newblock;
3428 punch_map.m_len = punched_out;
3429 punch_map.m_flags = 0;
3430
3431 /* Check to see if the extent needs to be split */
3432 if (punch_map.m_len != ee_len ||
3433 punch_map.m_lblk != ee_block) {
3434
3435 ret = ext4_split_extent(handle, inode,
3436 path, &punch_map, 0,
3437 EXT4_GET_BLOCKS_PUNCH_OUT_EXT |
3438 EXT4_GET_BLOCKS_PRE_IO);
3439
3440 if (ret < 0) {
3441 err = ret;
3442 goto out2;
3443 }
3444 /*
3445 * find extent for the block at
3446 * the start of the hole
3447 */
3448 ext4_ext_drop_refs(path);
3449 kfree(path);
3450
3451 path = ext4_ext_find_extent(inode,
3452 map->m_lblk, NULL);
3453 if (IS_ERR(path)) {
3454 err = PTR_ERR(path);
3455 path = NULL;
3456 goto out2;
3457 }
3458
3459 depth = ext_depth(inode);
3460 ex = path[depth].p_ext;
3461 ee_len = ext4_ext_get_actual_len(ex);
3462 ee_block = le32_to_cpu(ex->ee_block);
3463 ee_start = ext4_ext_pblock(ex);
3464
3465 }
3466
3467 ext4_ext_mark_uninitialized(ex);
3468
3469 ext4_ext_invalidate_cache(inode);
3470
3471 err = ext4_ext_rm_leaf(handle, inode, path,
3472 map->m_lblk, map->m_lblk + punched_out);
3473
3474 if (!err && path->p_hdr->eh_entries == 0) {
3475 /*
3476 * Punch hole freed all of this sub tree,
3477 * so we need to correct eh_depth
3478 */
3479 err = ext4_ext_get_access(handle, inode, path);
3480 if (err == 0) {
3481 ext_inode_hdr(inode)->eh_depth = 0;
3482 ext_inode_hdr(inode)->eh_max =
3483 cpu_to_le16(ext4_ext_space_root(
3484 inode, 0));
3485
3486 err = ext4_ext_dirty(
3487 handle, inode, path);
3488 }
3489 }
3490
3491 goto out2;
3492 }
3493 }
3494
3495 /*
3496 * requested block isn't allocated yet;
3497 * we couldn't try to create block if create flag is zero
3498 */
3499 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
3500 /*
3501 * put just found gap into cache to speed up
3502 * subsequent requests
3503 */
3504 ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
3505 goto out2;
3506 }
3507 /*
3508 * Okay, we need to do block allocation.
3509 */
3510
3511 /* find neighbour allocated blocks */
3512 ar.lleft = map->m_lblk;
3513 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
3514 if (err)
3515 goto out2;
3516 ar.lright = map->m_lblk;
3517 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright);
3518 if (err)
3519 goto out2;
3520
3521 /*
3522 * See if request is beyond maximum number of blocks we can have in
3523 * a single extent. For an initialized extent this limit is
3524 * EXT_INIT_MAX_LEN and for an uninitialized extent this limit is
3525 * EXT_UNINIT_MAX_LEN.
3526 */
3527 if (map->m_len > EXT_INIT_MAX_LEN &&
3528 !(flags & EXT4_GET_BLOCKS_UNINIT_EXT))
3529 map->m_len = EXT_INIT_MAX_LEN;
3530 else if (map->m_len > EXT_UNINIT_MAX_LEN &&
3531 (flags & EXT4_GET_BLOCKS_UNINIT_EXT))
3532 map->m_len = EXT_UNINIT_MAX_LEN;
3533
3534 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
3535 newex.ee_block = cpu_to_le32(map->m_lblk);
3536 newex.ee_len = cpu_to_le16(map->m_len);
3537 err = ext4_ext_check_overlap(inode, &newex, path);
3538 if (err)
3539 allocated = ext4_ext_get_actual_len(&newex);
3540 else
3541 allocated = map->m_len;
3542
3543 /* allocate new block */
3544 ar.inode = inode;
3545 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
3546 ar.logical = map->m_lblk;
3547 ar.len = allocated;
3548 if (S_ISREG(inode->i_mode))
3549 ar.flags = EXT4_MB_HINT_DATA;
3550 else
3551 /* disable in-core preallocation for non-regular files */
3552 ar.flags = 0;
3553 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
3554 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
3555 newblock = ext4_mb_new_blocks(handle, &ar, &err);
3556 if (!newblock)
3557 goto out2;
3558 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
3559 ar.goal, newblock, allocated);
3560
3561 /* try to insert new extent into found leaf and return */
3562 ext4_ext_store_pblock(&newex, newblock);
3563 newex.ee_len = cpu_to_le16(ar.len);
3564 /* Mark uninitialized */
3565 if (flags & EXT4_GET_BLOCKS_UNINIT_EXT){
3566 ext4_ext_mark_uninitialized(&newex);
3567 /*
3568 * io_end structure was created for every IO write to an
3569 * uninitialized extent. To avoid unnecessary conversion,
3570 * here we flag the IO that really needs the conversion.
3571 * For non asycn direct IO case, flag the inode state
3572 * that we need to perform conversion when IO is done.
3573 */
3574 if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
3575 if (io && !(io->flag & EXT4_IO_END_UNWRITTEN)) {
3576 io->flag = EXT4_IO_END_UNWRITTEN;
3577 atomic_inc(&EXT4_I(inode)->i_aiodio_unwritten);
3578 } else
3579 ext4_set_inode_state(inode,
3580 EXT4_STATE_DIO_UNWRITTEN);
3581 }
3582 if (ext4_should_dioread_nolock(inode))
3583 map->m_flags |= EXT4_MAP_UNINIT;
3584 }
3585
3586 err = check_eofblocks_fl(handle, inode, map->m_lblk, path, ar.len);
3587 if (!err)
3588 err = ext4_ext_insert_extent(handle, inode, path,
3589 &newex, flags);
3590 if (err) {
3591 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
3592 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
3593 /* free data blocks we just allocated */
3594 /* not a good idea to call discard here directly,
3595 * but otherwise we'd need to call it every free() */
3596 ext4_discard_preallocations(inode);
3597 ext4_free_blocks(handle, inode, NULL, ext4_ext_pblock(&newex),
3598 ext4_ext_get_actual_len(&newex), fb_flags);
3599 goto out2;
3600 }
3601
3602 /* previous routine could use block we allocated */
3603 newblock = ext4_ext_pblock(&newex);
3604 allocated = ext4_ext_get_actual_len(&newex);
3605 if (allocated > map->m_len)
3606 allocated = map->m_len;
3607 map->m_flags |= EXT4_MAP_NEW;
3608
3609 /*
3610 * Update reserved blocks/metadata blocks after successful
3611 * block allocation which had been deferred till now.
3612 */
3613 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
3614 ext4_da_update_reserve_space(inode, allocated, 1);
3615
3616 /*
3617 * Cache the extent and update transaction to commit on fdatasync only
3618 * when it is _not_ an uninitialized extent.
3619 */
3620 if ((flags & EXT4_GET_BLOCKS_UNINIT_EXT) == 0) {
3621 ext4_ext_put_in_cache(inode, map->m_lblk, allocated, newblock);
3622 ext4_update_inode_fsync_trans(handle, inode, 1);
3623 } else
3624 ext4_update_inode_fsync_trans(handle, inode, 0);
3625out:
3626 if (allocated > map->m_len)
3627 allocated = map->m_len;
3628 ext4_ext_show_leaf(inode, path);
3629 map->m_flags |= EXT4_MAP_MAPPED;
3630 map->m_pblk = newblock;
3631 map->m_len = allocated;
3632out2:
3633 if (path) {
3634 ext4_ext_drop_refs(path);
3635 kfree(path);
3636 }
3637 trace_ext4_ext_map_blocks_exit(inode, map->m_lblk,
3638 newblock, map->m_len, err ? err : allocated);
3639
3640 result = (flags & EXT4_GET_BLOCKS_PUNCH_OUT_EXT) ?
3641 punched_out : allocated;
3642
3643 return err ? err : result;
3644}
3645
3646void ext4_ext_truncate(struct inode *inode)
3647{
3648 struct address_space *mapping = inode->i_mapping;
3649 struct super_block *sb = inode->i_sb;
3650 ext4_lblk_t last_block;
3651 handle_t *handle;
3652 int err = 0;
3653
3654 /*
3655 * finish any pending end_io work so we won't run the risk of
3656 * converting any truncated blocks to initialized later
3657 */
3658 ext4_flush_completed_IO(inode);
3659
3660 /*
3661 * probably first extent we're gonna free will be last in block
3662 */
3663 err = ext4_writepage_trans_blocks(inode);
3664 handle = ext4_journal_start(inode, err);
3665 if (IS_ERR(handle))
3666 return;
3667
3668 if (inode->i_size & (sb->s_blocksize - 1))
3669 ext4_block_truncate_page(handle, mapping, inode->i_size);
3670
3671 if (ext4_orphan_add(handle, inode))
3672 goto out_stop;
3673
3674 down_write(&EXT4_I(inode)->i_data_sem);
3675 ext4_ext_invalidate_cache(inode);
3676
3677 ext4_discard_preallocations(inode);
3678
3679 /*
3680 * TODO: optimization is possible here.
3681 * Probably we need not scan at all,
3682 * because page truncation is enough.
3683 */
3684
3685 /* we have to know where to truncate from in crash case */
3686 EXT4_I(inode)->i_disksize = inode->i_size;
3687 ext4_mark_inode_dirty(handle, inode);
3688
3689 last_block = (inode->i_size + sb->s_blocksize - 1)
3690 >> EXT4_BLOCK_SIZE_BITS(sb);
3691 err = ext4_ext_remove_space(inode, last_block);
3692
3693 /* In a multi-transaction truncate, we only make the final
3694 * transaction synchronous.
3695 */
3696 if (IS_SYNC(inode))
3697 ext4_handle_sync(handle);
3698
3699 up_write(&EXT4_I(inode)->i_data_sem);
3700
3701out_stop:
3702 /*
3703 * If this was a simple ftruncate() and the file will remain alive,
3704 * then we need to clear up the orphan record which we created above.
3705 * However, if this was a real unlink then we were called by
3706 * ext4_delete_inode(), and we allow that function to clean up the
3707 * orphan info for us.
3708 */
3709 if (inode->i_nlink)
3710 ext4_orphan_del(handle, inode);
3711
3712 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
3713 ext4_mark_inode_dirty(handle, inode);
3714 ext4_journal_stop(handle);
3715}
3716
3717static void ext4_falloc_update_inode(struct inode *inode,
3718 int mode, loff_t new_size, int update_ctime)
3719{
3720 struct timespec now;
3721
3722 if (update_ctime) {
3723 now = current_fs_time(inode->i_sb);
3724 if (!timespec_equal(&inode->i_ctime, &now))
3725 inode->i_ctime = now;
3726 }
3727 /*
3728 * Update only when preallocation was requested beyond
3729 * the file size.
3730 */
3731 if (!(mode & FALLOC_FL_KEEP_SIZE)) {
3732 if (new_size > i_size_read(inode))
3733 i_size_write(inode, new_size);
3734 if (new_size > EXT4_I(inode)->i_disksize)
3735 ext4_update_i_disksize(inode, new_size);
3736 } else {
3737 /*
3738 * Mark that we allocate beyond EOF so the subsequent truncate
3739 * can proceed even if the new size is the same as i_size.
3740 */
3741 if (new_size > i_size_read(inode))
3742 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3743 }
3744
3745}
3746
3747/*
3748 * preallocate space for a file. This implements ext4's fallocate file
3749 * operation, which gets called from sys_fallocate system call.
3750 * For block-mapped files, posix_fallocate should fall back to the method
3751 * of writing zeroes to the required new blocks (the same behavior which is
3752 * expected for file systems which do not support fallocate() system call).
3753 */
3754long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
3755{
3756 struct inode *inode = file->f_path.dentry->d_inode;
3757 handle_t *handle;
3758 loff_t new_size;
3759 unsigned int max_blocks;
3760 int ret = 0;
3761 int ret2 = 0;
3762 int retries = 0;
3763 struct ext4_map_blocks map;
3764 unsigned int credits, blkbits = inode->i_blkbits;
3765
3766 /*
3767 * currently supporting (pre)allocate mode for extent-based
3768 * files _only_
3769 */
3770 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
3771 return -EOPNOTSUPP;
3772
3773 /* Return error if mode is not supported */
3774 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
3775 return -EOPNOTSUPP;
3776
3777 if (mode & FALLOC_FL_PUNCH_HOLE)
3778 return ext4_punch_hole(file, offset, len);
3779
3780 trace_ext4_fallocate_enter(inode, offset, len, mode);
3781 map.m_lblk = offset >> blkbits;
3782 /*
3783 * We can't just convert len to max_blocks because
3784 * If blocksize = 4096 offset = 3072 and len = 2048
3785 */
3786 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
3787 - map.m_lblk;
3788 /*
3789 * credits to insert 1 extent into extent tree
3790 */
3791 credits = ext4_chunk_trans_blocks(inode, max_blocks);
3792 mutex_lock(&inode->i_mutex);
3793 ret = inode_newsize_ok(inode, (len + offset));
3794 if (ret) {
3795 mutex_unlock(&inode->i_mutex);
3796 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
3797 return ret;
3798 }
3799retry:
3800 while (ret >= 0 && ret < max_blocks) {
3801 map.m_lblk = map.m_lblk + ret;
3802 map.m_len = max_blocks = max_blocks - ret;
3803 handle = ext4_journal_start(inode, credits);
3804 if (IS_ERR(handle)) {
3805 ret = PTR_ERR(handle);
3806 break;
3807 }
3808 ret = ext4_map_blocks(handle, inode, &map,
3809 EXT4_GET_BLOCKS_CREATE_UNINIT_EXT |
3810 EXT4_GET_BLOCKS_NO_NORMALIZE);
3811 if (ret <= 0) {
3812#ifdef EXT4FS_DEBUG
3813 WARN_ON(ret <= 0);
3814 printk(KERN_ERR "%s: ext4_ext_map_blocks "
3815 "returned error inode#%lu, block=%u, "
3816 "max_blocks=%u", __func__,
3817 inode->i_ino, map.m_lblk, max_blocks);
3818#endif
3819 ext4_mark_inode_dirty(handle, inode);
3820 ret2 = ext4_journal_stop(handle);
3821 break;
3822 }
3823 if ((map.m_lblk + ret) >= (EXT4_BLOCK_ALIGN(offset + len,
3824 blkbits) >> blkbits))
3825 new_size = offset + len;
3826 else
3827 new_size = ((loff_t) map.m_lblk + ret) << blkbits;
3828
3829 ext4_falloc_update_inode(inode, mode, new_size,
3830 (map.m_flags & EXT4_MAP_NEW));
3831 ext4_mark_inode_dirty(handle, inode);
3832 ret2 = ext4_journal_stop(handle);
3833 if (ret2)
3834 break;
3835 }
3836 if (ret == -ENOSPC &&
3837 ext4_should_retry_alloc(inode->i_sb, &retries)) {
3838 ret = 0;
3839 goto retry;
3840 }
3841 mutex_unlock(&inode->i_mutex);
3842 trace_ext4_fallocate_exit(inode, offset, max_blocks,
3843 ret > 0 ? ret2 : ret);
3844 return ret > 0 ? ret2 : ret;
3845}
3846
3847/*
3848 * This function convert a range of blocks to written extents
3849 * The caller of this function will pass the start offset and the size.
3850 * all unwritten extents within this range will be converted to
3851 * written extents.
3852 *
3853 * This function is called from the direct IO end io call back
3854 * function, to convert the fallocated extents after IO is completed.
3855 * Returns 0 on success.
3856 */
3857int ext4_convert_unwritten_extents(struct inode *inode, loff_t offset,
3858 ssize_t len)
3859{
3860 handle_t *handle;
3861 unsigned int max_blocks;
3862 int ret = 0;
3863 int ret2 = 0;
3864 struct ext4_map_blocks map;
3865 unsigned int credits, blkbits = inode->i_blkbits;
3866
3867 map.m_lblk = offset >> blkbits;
3868 /*
3869 * We can't just convert len to max_blocks because
3870 * If blocksize = 4096 offset = 3072 and len = 2048
3871 */
3872 max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
3873 map.m_lblk);
3874 /*
3875 * credits to insert 1 extent into extent tree
3876 */
3877 credits = ext4_chunk_trans_blocks(inode, max_blocks);
3878 while (ret >= 0 && ret < max_blocks) {
3879 map.m_lblk += ret;
3880 map.m_len = (max_blocks -= ret);
3881 handle = ext4_journal_start(inode, credits);
3882 if (IS_ERR(handle)) {
3883 ret = PTR_ERR(handle);
3884 break;
3885 }
3886 ret = ext4_map_blocks(handle, inode, &map,
3887 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
3888 if (ret <= 0) {
3889 WARN_ON(ret <= 0);
3890 printk(KERN_ERR "%s: ext4_ext_map_blocks "
3891 "returned error inode#%lu, block=%u, "
3892 "max_blocks=%u", __func__,
3893 inode->i_ino, map.m_lblk, map.m_len);
3894 }
3895 ext4_mark_inode_dirty(handle, inode);
3896 ret2 = ext4_journal_stop(handle);
3897 if (ret <= 0 || ret2 )
3898 break;
3899 }
3900 return ret > 0 ? ret2 : ret;
3901}
3902
3903/*
3904 * Callback function called for each extent to gather FIEMAP information.
3905 */
3906static int ext4_ext_fiemap_cb(struct inode *inode, ext4_lblk_t next,
3907 struct ext4_ext_cache *newex, struct ext4_extent *ex,
3908 void *data)
3909{
3910 __u64 logical;
3911 __u64 physical;
3912 __u64 length;
3913 __u32 flags = 0;
3914 int ret = 0;
3915 struct fiemap_extent_info *fieinfo = data;
3916 unsigned char blksize_bits;
3917
3918 blksize_bits = inode->i_sb->s_blocksize_bits;
3919 logical = (__u64)newex->ec_block << blksize_bits;
3920
3921 if (newex->ec_start == 0) {
3922 /*
3923 * No extent in extent-tree contains block @newex->ec_start,
3924 * then the block may stay in 1)a hole or 2)delayed-extent.
3925 *
3926 * Holes or delayed-extents are processed as follows.
3927 * 1. lookup dirty pages with specified range in pagecache.
3928 * If no page is got, then there is no delayed-extent and
3929 * return with EXT_CONTINUE.
3930 * 2. find the 1st mapped buffer,
3931 * 3. check if the mapped buffer is both in the request range
3932 * and a delayed buffer. If not, there is no delayed-extent,
3933 * then return.
3934 * 4. a delayed-extent is found, the extent will be collected.
3935 */
3936 ext4_lblk_t end = 0;
3937 pgoff_t last_offset;
3938 pgoff_t offset;
3939 pgoff_t index;
3940 pgoff_t start_index = 0;
3941 struct page **pages = NULL;
3942 struct buffer_head *bh = NULL;
3943 struct buffer_head *head = NULL;
3944 unsigned int nr_pages = PAGE_SIZE / sizeof(struct page *);
3945
3946 pages = kmalloc(PAGE_SIZE, GFP_KERNEL);
3947 if (pages == NULL)
3948 return -ENOMEM;
3949
3950 offset = logical >> PAGE_SHIFT;
3951repeat:
3952 last_offset = offset;
3953 head = NULL;
3954 ret = find_get_pages_tag(inode->i_mapping, &offset,
3955 PAGECACHE_TAG_DIRTY, nr_pages, pages);
3956
3957 if (!(flags & FIEMAP_EXTENT_DELALLOC)) {
3958 /* First time, try to find a mapped buffer. */
3959 if (ret == 0) {
3960out:
3961 for (index = 0; index < ret; index++)
3962 page_cache_release(pages[index]);
3963 /* just a hole. */
3964 kfree(pages);
3965 return EXT_CONTINUE;
3966 }
3967 index = 0;
3968
3969next_page:
3970 /* Try to find the 1st mapped buffer. */
3971 end = ((__u64)pages[index]->index << PAGE_SHIFT) >>
3972 blksize_bits;
3973 if (!page_has_buffers(pages[index]))
3974 goto out;
3975 head = page_buffers(pages[index]);
3976 if (!head)
3977 goto out;
3978
3979 index++;
3980 bh = head;
3981 do {
3982 if (end >= newex->ec_block +
3983 newex->ec_len)
3984 /* The buffer is out of
3985 * the request range.
3986 */
3987 goto out;
3988
3989 if (buffer_mapped(bh) &&
3990 end >= newex->ec_block) {
3991 start_index = index - 1;
3992 /* get the 1st mapped buffer. */
3993 goto found_mapped_buffer;
3994 }
3995
3996 bh = bh->b_this_page;
3997 end++;
3998 } while (bh != head);
3999
4000 /* No mapped buffer in the range found in this page,
4001 * We need to look up next page.
4002 */
4003 if (index >= ret) {
4004 /* There is no page left, but we need to limit
4005 * newex->ec_len.
4006 */
4007 newex->ec_len = end - newex->ec_block;
4008 goto out;
4009 }
4010 goto next_page;
4011 } else {
4012 /*Find contiguous delayed buffers. */
4013 if (ret > 0 && pages[0]->index == last_offset)
4014 head = page_buffers(pages[0]);
4015 bh = head;
4016 index = 1;
4017 start_index = 0;
4018 }
4019
4020found_mapped_buffer:
4021 if (bh != NULL && buffer_delay(bh)) {
4022 /* 1st or contiguous delayed buffer found. */
4023 if (!(flags & FIEMAP_EXTENT_DELALLOC)) {
4024 /*
4025 * 1st delayed buffer found, record
4026 * the start of extent.
4027 */
4028 flags |= FIEMAP_EXTENT_DELALLOC;
4029 newex->ec_block = end;
4030 logical = (__u64)end << blksize_bits;
4031 }
4032 /* Find contiguous delayed buffers. */
4033 do {
4034 if (!buffer_delay(bh))
4035 goto found_delayed_extent;
4036 bh = bh->b_this_page;
4037 end++;
4038 } while (bh != head);
4039
4040 for (; index < ret; index++) {
4041 if (!page_has_buffers(pages[index])) {
4042 bh = NULL;
4043 break;
4044 }
4045 head = page_buffers(pages[index]);
4046 if (!head) {
4047 bh = NULL;
4048 break;
4049 }
4050
4051 if (pages[index]->index !=
4052 pages[start_index]->index + index
4053 - start_index) {
4054 /* Blocks are not contiguous. */
4055 bh = NULL;
4056 break;
4057 }
4058 bh = head;
4059 do {
4060 if (!buffer_delay(bh))
4061 /* Delayed-extent ends. */
4062 goto found_delayed_extent;
4063 bh = bh->b_this_page;
4064 end++;
4065 } while (bh != head);
4066 }
4067 } else if (!(flags & FIEMAP_EXTENT_DELALLOC))
4068 /* a hole found. */
4069 goto out;
4070
4071found_delayed_extent:
4072 newex->ec_len = min(end - newex->ec_block,
4073 (ext4_lblk_t)EXT_INIT_MAX_LEN);
4074 if (ret == nr_pages && bh != NULL &&
4075 newex->ec_len < EXT_INIT_MAX_LEN &&
4076 buffer_delay(bh)) {
4077 /* Have not collected an extent and continue. */
4078 for (index = 0; index < ret; index++)
4079 page_cache_release(pages[index]);
4080 goto repeat;
4081 }
4082
4083 for (index = 0; index < ret; index++)
4084 page_cache_release(pages[index]);
4085 kfree(pages);
4086 }
4087
4088 physical = (__u64)newex->ec_start << blksize_bits;
4089 length = (__u64)newex->ec_len << blksize_bits;
4090
4091 if (ex && ext4_ext_is_uninitialized(ex))
4092 flags |= FIEMAP_EXTENT_UNWRITTEN;
4093
4094 if (next == EXT_MAX_BLOCKS)
4095 flags |= FIEMAP_EXTENT_LAST;
4096
4097 ret = fiemap_fill_next_extent(fieinfo, logical, physical,
4098 length, flags);
4099 if (ret < 0)
4100 return ret;
4101 if (ret == 1)
4102 return EXT_BREAK;
4103 return EXT_CONTINUE;
4104}
4105
4106/* fiemap flags we can handle specified here */
4107#define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
4108
4109static int ext4_xattr_fiemap(struct inode *inode,
4110 struct fiemap_extent_info *fieinfo)
4111{
4112 __u64 physical = 0;
4113 __u64 length;
4114 __u32 flags = FIEMAP_EXTENT_LAST;
4115 int blockbits = inode->i_sb->s_blocksize_bits;
4116 int error = 0;
4117
4118 /* in-inode? */
4119 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
4120 struct ext4_iloc iloc;
4121 int offset; /* offset of xattr in inode */
4122
4123 error = ext4_get_inode_loc(inode, &iloc);
4124 if (error)
4125 return error;
4126 physical = iloc.bh->b_blocknr << blockbits;
4127 offset = EXT4_GOOD_OLD_INODE_SIZE +
4128 EXT4_I(inode)->i_extra_isize;
4129 physical += offset;
4130 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
4131 flags |= FIEMAP_EXTENT_DATA_INLINE;
4132 brelse(iloc.bh);
4133 } else { /* external block */
4134 physical = EXT4_I(inode)->i_file_acl << blockbits;
4135 length = inode->i_sb->s_blocksize;
4136 }
4137
4138 if (physical)
4139 error = fiemap_fill_next_extent(fieinfo, 0, physical,
4140 length, flags);
4141 return (error < 0 ? error : 0);
4142}
4143
4144/*
4145 * ext4_ext_punch_hole
4146 *
4147 * Punches a hole of "length" bytes in a file starting
4148 * at byte "offset"
4149 *
4150 * @inode: The inode of the file to punch a hole in
4151 * @offset: The starting byte offset of the hole
4152 * @length: The length of the hole
4153 *
4154 * Returns the number of blocks removed or negative on err
4155 */
4156int ext4_ext_punch_hole(struct file *file, loff_t offset, loff_t length)
4157{
4158 struct inode *inode = file->f_path.dentry->d_inode;
4159 struct super_block *sb = inode->i_sb;
4160 struct ext4_ext_cache cache_ex;
4161 ext4_lblk_t first_block, last_block, num_blocks, iblock, max_blocks;
4162 struct address_space *mapping = inode->i_mapping;
4163 struct ext4_map_blocks map;
4164 handle_t *handle;
4165 loff_t first_block_offset, last_block_offset, block_len;
4166 loff_t first_page, last_page, first_page_offset, last_page_offset;
4167 int ret, credits, blocks_released, err = 0;
4168
4169 first_block = (offset + sb->s_blocksize - 1) >>
4170 EXT4_BLOCK_SIZE_BITS(sb);
4171 last_block = (offset + length) >> EXT4_BLOCK_SIZE_BITS(sb);
4172
4173 first_block_offset = first_block << EXT4_BLOCK_SIZE_BITS(sb);
4174 last_block_offset = last_block << EXT4_BLOCK_SIZE_BITS(sb);
4175
4176 first_page = (offset + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
4177 last_page = (offset + length) >> PAGE_CACHE_SHIFT;
4178
4179 first_page_offset = first_page << PAGE_CACHE_SHIFT;
4180 last_page_offset = last_page << PAGE_CACHE_SHIFT;
4181
4182 /*
4183 * Write out all dirty pages to avoid race conditions
4184 * Then release them.
4185 */
4186 if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
4187 err = filemap_write_and_wait_range(mapping,
4188 first_page_offset == 0 ? 0 : first_page_offset-1,
4189 last_page_offset);
4190
4191 if (err)
4192 return err;
4193 }
4194
4195 /* Now release the pages */
4196 if (last_page_offset > first_page_offset) {
4197 truncate_inode_pages_range(mapping, first_page_offset,
4198 last_page_offset-1);
4199 }
4200
4201 /* finish any pending end_io work */
4202 ext4_flush_completed_IO(inode);
4203
4204 credits = ext4_writepage_trans_blocks(inode);
4205 handle = ext4_journal_start(inode, credits);
4206 if (IS_ERR(handle))
4207 return PTR_ERR(handle);
4208
4209 err = ext4_orphan_add(handle, inode);
4210 if (err)
4211 goto out;
4212
4213 /*
4214 * Now we need to zero out the un block aligned data.
4215 * If the file is smaller than a block, just
4216 * zero out the middle
4217 */
4218 if (first_block > last_block)
4219 ext4_block_zero_page_range(handle, mapping, offset, length);
4220 else {
4221 /* zero out the head of the hole before the first block */
4222 block_len = first_block_offset - offset;
4223 if (block_len > 0)
4224 ext4_block_zero_page_range(handle, mapping,
4225 offset, block_len);
4226
4227 /* zero out the tail of the hole after the last block */
4228 block_len = offset + length - last_block_offset;
4229 if (block_len > 0) {
4230 ext4_block_zero_page_range(handle, mapping,
4231 last_block_offset, block_len);
4232 }
4233 }
4234
4235 /* If there are no blocks to remove, return now */
4236 if (first_block >= last_block)
4237 goto out;
4238
4239 down_write(&EXT4_I(inode)->i_data_sem);
4240 ext4_ext_invalidate_cache(inode);
4241 ext4_discard_preallocations(inode);
4242
4243 /*
4244 * Loop over all the blocks and identify blocks
4245 * that need to be punched out
4246 */
4247 iblock = first_block;
4248 blocks_released = 0;
4249 while (iblock < last_block) {
4250 max_blocks = last_block - iblock;
4251 num_blocks = 1;
4252 memset(&map, 0, sizeof(map));
4253 map.m_lblk = iblock;
4254 map.m_len = max_blocks;
4255 ret = ext4_ext_map_blocks(handle, inode, &map,
4256 EXT4_GET_BLOCKS_PUNCH_OUT_EXT);
4257
4258 if (ret > 0) {
4259 blocks_released += ret;
4260 num_blocks = ret;
4261 } else if (ret == 0) {
4262 /*
4263 * If map blocks could not find the block,
4264 * then it is in a hole. If the hole was
4265 * not already cached, then map blocks should
4266 * put it in the cache. So we can get the hole
4267 * out of the cache
4268 */
4269 memset(&cache_ex, 0, sizeof(cache_ex));
4270 if ((ext4_ext_check_cache(inode, iblock, &cache_ex)) &&
4271 !cache_ex.ec_start) {
4272
4273 /* The hole is cached */
4274 num_blocks = cache_ex.ec_block +
4275 cache_ex.ec_len - iblock;
4276
4277 } else {
4278 /* The block could not be identified */
4279 err = -EIO;
4280 break;
4281 }
4282 } else {
4283 /* Map blocks error */
4284 err = ret;
4285 break;
4286 }
4287
4288 if (num_blocks == 0) {
4289 /* This condition should never happen */
4290 ext_debug("Block lookup failed");
4291 err = -EIO;
4292 break;
4293 }
4294
4295 iblock += num_blocks;
4296 }
4297
4298 if (blocks_released > 0) {
4299 ext4_ext_invalidate_cache(inode);
4300 ext4_discard_preallocations(inode);
4301 }
4302
4303 if (IS_SYNC(inode))
4304 ext4_handle_sync(handle);
4305
4306 up_write(&EXT4_I(inode)->i_data_sem);
4307
4308out:
4309 ext4_orphan_del(handle, inode);
4310 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4311 ext4_mark_inode_dirty(handle, inode);
4312 ext4_journal_stop(handle);
4313 return err;
4314}
4315int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
4316 __u64 start, __u64 len)
4317{
4318 ext4_lblk_t start_blk;
4319 int error = 0;
4320
4321 /* fallback to generic here if not in extents fmt */
4322 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
4323 return generic_block_fiemap(inode, fieinfo, start, len,
4324 ext4_get_block);
4325
4326 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
4327 return -EBADR;
4328
4329 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
4330 error = ext4_xattr_fiemap(inode, fieinfo);
4331 } else {
4332 ext4_lblk_t len_blks;
4333 __u64 last_blk;
4334
4335 start_blk = start >> inode->i_sb->s_blocksize_bits;
4336 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
4337 if (last_blk >= EXT_MAX_BLOCKS)
4338 last_blk = EXT_MAX_BLOCKS-1;
4339 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
4340
4341 /*
4342 * Walk the extent tree gathering extent information.
4343 * ext4_ext_fiemap_cb will push extents back to user.
4344 */
4345 error = ext4_ext_walk_space(inode, start_blk, len_blks,
4346 ext4_ext_fiemap_cb, fieinfo);
4347 }
4348
4349 return error;
4350}