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of: MSI: Simplify irqdomain lookup
[linux/fpc-iii.git] / fs / ext4 / extents.c
blob551353b1b17ab930ead8eff62ee3a699b4cfe10f
1 /*
2 * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com
3 * Written by Alex Tomas <alex@clusterfs.com>
4 *
5 * Architecture independence:
6 * Copyright (c) 2005, Bull S.A.
7 * Written by Pierre Peiffer <pierre.peiffer@bull.net>
8 *
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License version 2 as
11 * published by the Free Software Foundation.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public Licens
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-
21 */
22
23 /*
24 * Extents support for EXT4
25 *
26 * TODO:
27 * - ext4*_error() should be used in some situations
28 * - analyze all BUG()/BUG_ON(), use -EIO where appropriate
29 * - smart tree reduction
30 */
31
32 #include <linux/fs.h>
33 #include <linux/time.h>
34 #include <linux/jbd2.h>
35 #include <linux/highuid.h>
36 #include <linux/pagemap.h>
37 #include <linux/quotaops.h>
38 #include <linux/string.h>
39 #include <linux/slab.h>
40 #include <asm/uaccess.h>
41 #include <linux/fiemap.h>
42 #include <linux/backing-dev.h>
43 #include "ext4_jbd2.h"
44 #include "ext4_extents.h"
45 #include "xattr.h"
46
47 #include <trace/events/ext4.h>
48
49 /*
50 * used by extent splitting.
51 */
52 #define EXT4_EXT_MAY_ZEROOUT 0x1 /* safe to zeroout if split fails \
53 due to ENOSPC */
54 #define EXT4_EXT_MARK_UNWRIT1 0x2 /* mark first half unwritten */
55 #define EXT4_EXT_MARK_UNWRIT2 0x4 /* mark second half unwritten */
56
57 #define EXT4_EXT_DATA_VALID1 0x8 /* first half contains valid data */
58 #define EXT4_EXT_DATA_VALID2 0x10 /* second half contains valid data */
59
60 static __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
72 static 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
86 static 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
98 static 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
105 static 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
112 static int ext4_find_delayed_extent(struct inode *inode,
113 struct extent_status *newes);
114
115 static int ext4_ext_truncate_extend_restart(handle_t *handle,
116 struct inode *inode,
117 int needed)
118 {
119 int err;
120
121 if (!ext4_handle_valid(handle))
122 return 0;
123 if (handle->h_buffer_credits > needed)
124 return 0;
125 err = ext4_journal_extend(handle, needed);
126 if (err <= 0)
127 return err;
128 err = ext4_truncate_restart_trans(handle, inode, needed);
129 if (err == 0)
130 err = -EAGAIN;
131
132 return err;
133 }
134
135 /*
136 * could return:
137 * - EROFS
138 * - ENOMEM
139 */
140 static int ext4_ext_get_access(handle_t *handle, struct inode *inode,
141 struct ext4_ext_path *path)
142 {
143 if (path->p_bh) {
144 /* path points to block */
145 BUFFER_TRACE(path->p_bh, "get_write_access");
146 return ext4_journal_get_write_access(handle, path->p_bh);
147 }
148 /* path points to leaf/index in inode body */
149 /* we use in-core data, no need to protect them */
150 return 0;
151 }
152
153 /*
154 * could return:
155 * - EROFS
156 * - ENOMEM
157 * - EIO
158 */
159 int __ext4_ext_dirty(const char *where, unsigned int line, handle_t *handle,
160 struct inode *inode, struct ext4_ext_path *path)
161 {
162 int err;
163
164 WARN_ON(!rwsem_is_locked(&EXT4_I(inode)->i_data_sem));
165 if (path->p_bh) {
166 ext4_extent_block_csum_set(inode, ext_block_hdr(path->p_bh));
167 /* path points to block */
168 err = __ext4_handle_dirty_metadata(where, line, handle,
169 inode, path->p_bh);
170 } else {
171 /* path points to leaf/index in inode body */
172 err = ext4_mark_inode_dirty(handle, inode);
173 }
174 return err;
175 }
176
177 static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode,
178 struct ext4_ext_path *path,
179 ext4_lblk_t block)
180 {
181 if (path) {
182 int depth = path->p_depth;
183 struct ext4_extent *ex;
184
185 /*
186 * Try to predict block placement assuming that we are
187 * filling in a file which will eventually be
188 * non-sparse --- i.e., in the case of libbfd writing
189 * an ELF object sections out-of-order but in a way
190 * the eventually results in a contiguous object or
191 * executable file, or some database extending a table
192 * space file. However, this is actually somewhat
193 * non-ideal if we are writing a sparse file such as
194 * qemu or KVM writing a raw image file that is going
195 * to stay fairly sparse, since it will end up
196 * fragmenting the file system's free space. Maybe we
197 * should have some hueristics or some way to allow
198 * userspace to pass a hint to file system,
199 * especially if the latter case turns out to be
200 * common.
201 */
202 ex = path[depth].p_ext;
203 if (ex) {
204 ext4_fsblk_t ext_pblk = ext4_ext_pblock(ex);
205 ext4_lblk_t ext_block = le32_to_cpu(ex->ee_block);
206
207 if (block > ext_block)
208 return ext_pblk + (block - ext_block);
209 else
210 return ext_pblk - (ext_block - block);
211 }
212
213 /* it looks like index is empty;
214 * try to find starting block from index itself */
215 if (path[depth].p_bh)
216 return path[depth].p_bh->b_blocknr;
217 }
218
219 /* OK. use inode's group */
220 return ext4_inode_to_goal_block(inode);
221 }
222
223 /*
224 * Allocation for a meta data block
225 */
226 static ext4_fsblk_t
227 ext4_ext_new_meta_block(handle_t *handle, struct inode *inode,
228 struct ext4_ext_path *path,
229 struct ext4_extent *ex, int *err, unsigned int flags)
230 {
231 ext4_fsblk_t goal, newblock;
232
233 goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block));
234 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
235 NULL, err);
236 return newblock;
237 }
238
239 static inline int ext4_ext_space_block(struct inode *inode, int check)
240 {
241 int size;
242
243 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
244 / sizeof(struct ext4_extent);
245 #ifdef AGGRESSIVE_TEST
246 if (!check && size > 6)
247 size = 6;
248 #endif
249 return size;
250 }
251
252 static inline int ext4_ext_space_block_idx(struct inode *inode, int check)
253 {
254 int size;
255
256 size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
257 / sizeof(struct ext4_extent_idx);
258 #ifdef AGGRESSIVE_TEST
259 if (!check && size > 5)
260 size = 5;
261 #endif
262 return size;
263 }
264
265 static inline int ext4_ext_space_root(struct inode *inode, int check)
266 {
267 int size;
268
269 size = sizeof(EXT4_I(inode)->i_data);
270 size -= sizeof(struct ext4_extent_header);
271 size /= sizeof(struct ext4_extent);
272 #ifdef AGGRESSIVE_TEST
273 if (!check && size > 3)
274 size = 3;
275 #endif
276 return size;
277 }
278
279 static inline int ext4_ext_space_root_idx(struct inode *inode, int check)
280 {
281 int size;
282
283 size = sizeof(EXT4_I(inode)->i_data);
284 size -= sizeof(struct ext4_extent_header);
285 size /= sizeof(struct ext4_extent_idx);
286 #ifdef AGGRESSIVE_TEST
287 if (!check && size > 4)
288 size = 4;
289 #endif
290 return size;
291 }
292
293 static inline int
294 ext4_force_split_extent_at(handle_t *handle, struct inode *inode,
295 struct ext4_ext_path **ppath, ext4_lblk_t lblk,
296 int nofail)
297 {
298 struct ext4_ext_path *path = *ppath;
299 int unwritten = ext4_ext_is_unwritten(path[path->p_depth].p_ext);
300
301 return ext4_split_extent_at(handle, inode, ppath, lblk, unwritten ?
302 EXT4_EXT_MARK_UNWRIT1|EXT4_EXT_MARK_UNWRIT2 : 0,
303 EXT4_EX_NOCACHE | EXT4_GET_BLOCKS_PRE_IO |
304 (nofail ? EXT4_GET_BLOCKS_METADATA_NOFAIL:0));
305 }
306
307 /*
308 * Calculate the number of metadata blocks needed
309 * to allocate @blocks
310 * Worse case is one block per extent
311 */
312 int ext4_ext_calc_metadata_amount(struct inode *inode, ext4_lblk_t lblock)
313 {
314 struct ext4_inode_info *ei = EXT4_I(inode);
315 int idxs;
316
317 idxs = ((inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header))
318 / sizeof(struct ext4_extent_idx));
319
320 /*
321 * If the new delayed allocation block is contiguous with the
322 * previous da block, it can share index blocks with the
323 * previous block, so we only need to allocate a new index
324 * block every idxs leaf blocks. At ldxs**2 blocks, we need
325 * an additional index block, and at ldxs**3 blocks, yet
326 * another index blocks.
327 */
328 if (ei->i_da_metadata_calc_len &&
329 ei->i_da_metadata_calc_last_lblock+1 == lblock) {
330 int num = 0;
331
332 if ((ei->i_da_metadata_calc_len % idxs) == 0)
333 num++;
334 if ((ei->i_da_metadata_calc_len % (idxs*idxs)) == 0)
335 num++;
336 if ((ei->i_da_metadata_calc_len % (idxs*idxs*idxs)) == 0) {
337 num++;
338 ei->i_da_metadata_calc_len = 0;
339 } else
340 ei->i_da_metadata_calc_len++;
341 ei->i_da_metadata_calc_last_lblock++;
342 return num;
343 }
344
345 /*
346 * In the worst case we need a new set of index blocks at
347 * every level of the inode's extent tree.
348 */
349 ei->i_da_metadata_calc_len = 1;
350 ei->i_da_metadata_calc_last_lblock = lblock;
351 return ext_depth(inode) + 1;
352 }
353
354 static int
355 ext4_ext_max_entries(struct inode *inode, int depth)
356 {
357 int max;
358
359 if (depth == ext_depth(inode)) {
360 if (depth == 0)
361 max = ext4_ext_space_root(inode, 1);
362 else
363 max = ext4_ext_space_root_idx(inode, 1);
364 } else {
365 if (depth == 0)
366 max = ext4_ext_space_block(inode, 1);
367 else
368 max = ext4_ext_space_block_idx(inode, 1);
369 }
370
371 return max;
372 }
373
374 static int ext4_valid_extent(struct inode *inode, struct ext4_extent *ext)
375 {
376 ext4_fsblk_t block = ext4_ext_pblock(ext);
377 int len = ext4_ext_get_actual_len(ext);
378 ext4_lblk_t lblock = le32_to_cpu(ext->ee_block);
379 ext4_lblk_t last = lblock + len - 1;
380
381 if (len == 0 || lblock > last)
382 return 0;
383 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, len);
384 }
385
386 static int ext4_valid_extent_idx(struct inode *inode,
387 struct ext4_extent_idx *ext_idx)
388 {
389 ext4_fsblk_t block = ext4_idx_pblock(ext_idx);
390
391 return ext4_data_block_valid(EXT4_SB(inode->i_sb), block, 1);
392 }
393
394 static int ext4_valid_extent_entries(struct inode *inode,
395 struct ext4_extent_header *eh,
396 int depth)
397 {
398 unsigned short entries;
399 if (eh->eh_entries == 0)
400 return 1;
401
402 entries = le16_to_cpu(eh->eh_entries);
403
404 if (depth == 0) {
405 /* leaf entries */
406 struct ext4_extent *ext = EXT_FIRST_EXTENT(eh);
407 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
408 ext4_fsblk_t pblock = 0;
409 ext4_lblk_t lblock = 0;
410 ext4_lblk_t prev = 0;
411 int len = 0;
412 while (entries) {
413 if (!ext4_valid_extent(inode, ext))
414 return 0;
415
416 /* Check for overlapping extents */
417 lblock = le32_to_cpu(ext->ee_block);
418 len = ext4_ext_get_actual_len(ext);
419 if ((lblock <= prev) && prev) {
420 pblock = ext4_ext_pblock(ext);
421 es->s_last_error_block = cpu_to_le64(pblock);
422 return 0;
423 }
424 ext++;
425 entries--;
426 prev = lblock + len - 1;
427 }
428 } else {
429 struct ext4_extent_idx *ext_idx = EXT_FIRST_INDEX(eh);
430 while (entries) {
431 if (!ext4_valid_extent_idx(inode, ext_idx))
432 return 0;
433 ext_idx++;
434 entries--;
435 }
436 }
437 return 1;
438 }
439
440 static int __ext4_ext_check(const char *function, unsigned int line,
441 struct inode *inode, struct ext4_extent_header *eh,
442 int depth, ext4_fsblk_t pblk)
443 {
444 const char *error_msg;
445 int max = 0, err = -EFSCORRUPTED;
446
447 if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) {
448 error_msg = "invalid magic";
449 goto corrupted;
450 }
451 if (unlikely(le16_to_cpu(eh->eh_depth) != depth)) {
452 error_msg = "unexpected eh_depth";
453 goto corrupted;
454 }
455 if (unlikely(eh->eh_max == 0)) {
456 error_msg = "invalid eh_max";
457 goto corrupted;
458 }
459 max = ext4_ext_max_entries(inode, depth);
460 if (unlikely(le16_to_cpu(eh->eh_max) > max)) {
461 error_msg = "too large eh_max";
462 goto corrupted;
463 }
464 if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) {
465 error_msg = "invalid eh_entries";
466 goto corrupted;
467 }
468 if (!ext4_valid_extent_entries(inode, eh, depth)) {
469 error_msg = "invalid extent entries";
470 goto corrupted;
471 }
472 /* Verify checksum on non-root extent tree nodes */
473 if (ext_depth(inode) != depth &&
474 !ext4_extent_block_csum_verify(inode, eh)) {
475 error_msg = "extent tree corrupted";
476 err = -EFSBADCRC;
477 goto corrupted;
478 }
479 return 0;
480
481 corrupted:
482 ext4_error_inode(inode, function, line, 0,
483 "pblk %llu bad header/extent: %s - magic %x, "
484 "entries %u, max %u(%u), depth %u(%u)",
485 (unsigned long long) pblk, error_msg,
486 le16_to_cpu(eh->eh_magic),
487 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
488 max, le16_to_cpu(eh->eh_depth), depth);
489 return err;
490 }
491
492 #define ext4_ext_check(inode, eh, depth, pblk) \
493 __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk))
494
495 int ext4_ext_check_inode(struct inode *inode)
496 {
497 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
498 }
499
500 static struct buffer_head *
501 __read_extent_tree_block(const char *function, unsigned int line,
502 struct inode *inode, ext4_fsblk_t pblk, int depth,
503 int flags)
504 {
505 struct buffer_head *bh;
506 int err;
507
508 bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
509 if (unlikely(!bh))
510 return ERR_PTR(-ENOMEM);
511
512 if (!bh_uptodate_or_lock(bh)) {
513 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
514 err = bh_submit_read(bh);
515 if (err < 0)
516 goto errout;
517 }
518 if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
519 return bh;
520 err = __ext4_ext_check(function, line, inode,
521 ext_block_hdr(bh), depth, pblk);
522 if (err)
523 goto errout;
524 set_buffer_verified(bh);
525 /*
526 * If this is a leaf block, cache all of its entries
527 */
528 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
529 struct ext4_extent_header *eh = ext_block_hdr(bh);
530 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
531 ext4_lblk_t prev = 0;
532 int i;
533
534 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
535 unsigned int status = EXTENT_STATUS_WRITTEN;
536 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
537 int len = ext4_ext_get_actual_len(ex);
538
539 if (prev && (prev != lblk))
540 ext4_es_cache_extent(inode, prev,
541 lblk - prev, ~0,
542 EXTENT_STATUS_HOLE);
543
544 if (ext4_ext_is_unwritten(ex))
545 status = EXTENT_STATUS_UNWRITTEN;
546 ext4_es_cache_extent(inode, lblk, len,
547 ext4_ext_pblock(ex), status);
548 prev = lblk + len;
549 }
550 }
551 return bh;
552 errout:
553 put_bh(bh);
554 return ERR_PTR(err);
555
556 }
557
558 #define read_extent_tree_block(inode, pblk, depth, flags) \
559 __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \
560 (depth), (flags))
561
562 /*
563 * This function is called to cache a file's extent information in the
564 * extent status tree
565 */
566 int ext4_ext_precache(struct inode *inode)
567 {
568 struct ext4_inode_info *ei = EXT4_I(inode);
569 struct ext4_ext_path *path = NULL;
570 struct buffer_head *bh;
571 int i = 0, depth, ret = 0;
572
573 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
574 return 0; /* not an extent-mapped inode */
575
576 down_read(&ei->i_data_sem);
577 depth = ext_depth(inode);
578
579 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
580 GFP_NOFS);
581 if (path == NULL) {
582 up_read(&ei->i_data_sem);
583 return -ENOMEM;
584 }
585
586 /* Don't cache anything if there are no external extent blocks */
587 if (depth == 0)
588 goto out;
589 path[0].p_hdr = ext_inode_hdr(inode);
590 ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
591 if (ret)
592 goto out;
593 path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
594 while (i >= 0) {
595 /*
596 * If this is a leaf block or we've reached the end of
597 * the index block, go up
598 */
599 if ((i == depth) ||
600 path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
601 brelse(path[i].p_bh);
602 path[i].p_bh = NULL;
603 i--;
604 continue;
605 }
606 bh = read_extent_tree_block(inode,
607 ext4_idx_pblock(path[i].p_idx++),
608 depth - i - 1,
609 EXT4_EX_FORCE_CACHE);
610 if (IS_ERR(bh)) {
611 ret = PTR_ERR(bh);
612 break;
613 }
614 i++;
615 path[i].p_bh = bh;
616 path[i].p_hdr = ext_block_hdr(bh);
617 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
618 }
619 ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
620 out:
621 up_read(&ei->i_data_sem);
622 ext4_ext_drop_refs(path);
623 kfree(path);
624 return ret;
625 }
626
627 #ifdef EXT_DEBUG
628 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
629 {
630 int k, l = path->p_depth;
631
632 ext_debug("path:");
633 for (k = 0; k <= l; k++, path++) {
634 if (path->p_idx) {
635 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
636 ext4_idx_pblock(path->p_idx));
637 } else if (path->p_ext) {
638 ext_debug(" %d:[%d]%d:%llu ",
639 le32_to_cpu(path->p_ext->ee_block),
640 ext4_ext_is_unwritten(path->p_ext),
641 ext4_ext_get_actual_len(path->p_ext),
642 ext4_ext_pblock(path->p_ext));
643 } else
644 ext_debug(" []");
645 }
646 ext_debug("\n");
647 }
648
649 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
650 {
651 int depth = ext_depth(inode);
652 struct ext4_extent_header *eh;
653 struct ext4_extent *ex;
654 int i;
655
656 if (!path)
657 return;
658
659 eh = path[depth].p_hdr;
660 ex = EXT_FIRST_EXTENT(eh);
661
662 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
663
664 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
665 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
666 ext4_ext_is_unwritten(ex),
667 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
668 }
669 ext_debug("\n");
670 }
671
672 static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
673 ext4_fsblk_t newblock, int level)
674 {
675 int depth = ext_depth(inode);
676 struct ext4_extent *ex;
677
678 if (depth != level) {
679 struct ext4_extent_idx *idx;
680 idx = path[level].p_idx;
681 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
682 ext_debug("%d: move %d:%llu in new index %llu\n", level,
683 le32_to_cpu(idx->ei_block),
684 ext4_idx_pblock(idx),
685 newblock);
686 idx++;
687 }
688
689 return;
690 }
691
692 ex = path[depth].p_ext;
693 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
694 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
695 le32_to_cpu(ex->ee_block),
696 ext4_ext_pblock(ex),
697 ext4_ext_is_unwritten(ex),
698 ext4_ext_get_actual_len(ex),
699 newblock);
700 ex++;
701 }
702 }
703
704 #else
705 #define ext4_ext_show_path(inode, path)
706 #define ext4_ext_show_leaf(inode, path)
707 #define ext4_ext_show_move(inode, path, newblock, level)
708 #endif
709
710 void ext4_ext_drop_refs(struct ext4_ext_path *path)
711 {
712 int depth, i;
713
714 if (!path)
715 return;
716 depth = path->p_depth;
717 for (i = 0; i <= depth; i++, path++)
718 if (path->p_bh) {
719 brelse(path->p_bh);
720 path->p_bh = NULL;
721 }
722 }
723
724 /*
725 * ext4_ext_binsearch_idx:
726 * binary search for the closest index of the given block
727 * the header must be checked before calling this
728 */
729 static void
730 ext4_ext_binsearch_idx(struct inode *inode,
731 struct ext4_ext_path *path, ext4_lblk_t block)
732 {
733 struct ext4_extent_header *eh = path->p_hdr;
734 struct ext4_extent_idx *r, *l, *m;
735
736
737 ext_debug("binsearch for %u(idx): ", block);
738
739 l = EXT_FIRST_INDEX(eh) + 1;
740 r = EXT_LAST_INDEX(eh);
741 while (l <= r) {
742 m = l + (r - l) / 2;
743 if (block < le32_to_cpu(m->ei_block))
744 r = m - 1;
745 else
746 l = m + 1;
747 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
748 m, le32_to_cpu(m->ei_block),
749 r, le32_to_cpu(r->ei_block));
750 }
751
752 path->p_idx = l - 1;
753 ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
754 ext4_idx_pblock(path->p_idx));
755
756 #ifdef CHECK_BINSEARCH
757 {
758 struct ext4_extent_idx *chix, *ix;
759 int k;
760
761 chix = ix = EXT_FIRST_INDEX(eh);
762 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
763 if (k != 0 &&
764 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
765 printk(KERN_DEBUG "k=%d, ix=0x%p, "
766 "first=0x%p\n", k,
767 ix, EXT_FIRST_INDEX(eh));
768 printk(KERN_DEBUG "%u <= %u\n",
769 le32_to_cpu(ix->ei_block),
770 le32_to_cpu(ix[-1].ei_block));
771 }
772 BUG_ON(k && le32_to_cpu(ix->ei_block)
773 <= le32_to_cpu(ix[-1].ei_block));
774 if (block < le32_to_cpu(ix->ei_block))
775 break;
776 chix = ix;
777 }
778 BUG_ON(chix != path->p_idx);
779 }
780 #endif
781
782 }
783
784 /*
785 * ext4_ext_binsearch:
786 * binary search for closest extent of the given block
787 * the header must be checked before calling this
788 */
789 static void
790 ext4_ext_binsearch(struct inode *inode,
791 struct ext4_ext_path *path, ext4_lblk_t block)
792 {
793 struct ext4_extent_header *eh = path->p_hdr;
794 struct ext4_extent *r, *l, *m;
795
796 if (eh->eh_entries == 0) {
797 /*
798 * this leaf is empty:
799 * we get such a leaf in split/add case
800 */
801 return;
802 }
803
804 ext_debug("binsearch for %u: ", block);
805
806 l = EXT_FIRST_EXTENT(eh) + 1;
807 r = EXT_LAST_EXTENT(eh);
808
809 while (l <= r) {
810 m = l + (r - l) / 2;
811 if (block < le32_to_cpu(m->ee_block))
812 r = m - 1;
813 else
814 l = m + 1;
815 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
816 m, le32_to_cpu(m->ee_block),
817 r, le32_to_cpu(r->ee_block));
818 }
819
820 path->p_ext = l - 1;
821 ext_debug(" -> %d:%llu:[%d]%d ",
822 le32_to_cpu(path->p_ext->ee_block),
823 ext4_ext_pblock(path->p_ext),
824 ext4_ext_is_unwritten(path->p_ext),
825 ext4_ext_get_actual_len(path->p_ext));
826
827 #ifdef CHECK_BINSEARCH
828 {
829 struct ext4_extent *chex, *ex;
830 int k;
831
832 chex = ex = EXT_FIRST_EXTENT(eh);
833 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
834 BUG_ON(k && le32_to_cpu(ex->ee_block)
835 <= le32_to_cpu(ex[-1].ee_block));
836 if (block < le32_to_cpu(ex->ee_block))
837 break;
838 chex = ex;
839 }
840 BUG_ON(chex != path->p_ext);
841 }
842 #endif
843
844 }
845
846 int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
847 {
848 struct ext4_extent_header *eh;
849
850 eh = ext_inode_hdr(inode);
851 eh->eh_depth = 0;
852 eh->eh_entries = 0;
853 eh->eh_magic = EXT4_EXT_MAGIC;
854 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
855 ext4_mark_inode_dirty(handle, inode);
856 return 0;
857 }
858
859 struct ext4_ext_path *
860 ext4_find_extent(struct inode *inode, ext4_lblk_t block,
861 struct ext4_ext_path **orig_path, int flags)
862 {
863 struct ext4_extent_header *eh;
864 struct buffer_head *bh;
865 struct ext4_ext_path *path = orig_path ? *orig_path : NULL;
866 short int depth, i, ppos = 0;
867 int ret;
868
869 eh = ext_inode_hdr(inode);
870 depth = ext_depth(inode);
871
872 if (path) {
873 ext4_ext_drop_refs(path);
874 if (depth > path[0].p_maxdepth) {
875 kfree(path);
876 *orig_path = path = NULL;
877 }
878 }
879 if (!path) {
880 /* account possible depth increase */
881 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
882 GFP_NOFS);
883 if (unlikely(!path))
884 return ERR_PTR(-ENOMEM);
885 path[0].p_maxdepth = depth + 1;
886 }
887 path[0].p_hdr = eh;
888 path[0].p_bh = NULL;
889
890 i = depth;
891 /* walk through the tree */
892 while (i) {
893 ext_debug("depth %d: num %d, max %d\n",
894 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
895
896 ext4_ext_binsearch_idx(inode, path + ppos, block);
897 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
898 path[ppos].p_depth = i;
899 path[ppos].p_ext = NULL;
900
901 bh = read_extent_tree_block(inode, path[ppos].p_block, --i,
902 flags);
903 if (IS_ERR(bh)) {
904 ret = PTR_ERR(bh);
905 goto err;
906 }
907
908 eh = ext_block_hdr(bh);
909 ppos++;
910 if (unlikely(ppos > depth)) {
911 put_bh(bh);
912 EXT4_ERROR_INODE(inode,
913 "ppos %d > depth %d", ppos, depth);
914 ret = -EFSCORRUPTED;
915 goto err;
916 }
917 path[ppos].p_bh = bh;
918 path[ppos].p_hdr = eh;
919 }
920
921 path[ppos].p_depth = i;
922 path[ppos].p_ext = NULL;
923 path[ppos].p_idx = NULL;
924
925 /* find extent */
926 ext4_ext_binsearch(inode, path + ppos, block);
927 /* if not an empty leaf */
928 if (path[ppos].p_ext)
929 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
930
931 ext4_ext_show_path(inode, path);
932
933 return path;
934
935 err:
936 ext4_ext_drop_refs(path);
937 kfree(path);
938 if (orig_path)
939 *orig_path = NULL;
940 return ERR_PTR(ret);
941 }
942
943 /*
944 * ext4_ext_insert_index:
945 * insert new index [@logical;@ptr] into the block at @curp;
946 * check where to insert: before @curp or after @curp
947 */
948 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
949 struct ext4_ext_path *curp,
950 int logical, ext4_fsblk_t ptr)
951 {
952 struct ext4_extent_idx *ix;
953 int len, err;
954
955 err = ext4_ext_get_access(handle, inode, curp);
956 if (err)
957 return err;
958
959 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
960 EXT4_ERROR_INODE(inode,
961 "logical %d == ei_block %d!",
962 logical, le32_to_cpu(curp->p_idx->ei_block));
963 return -EFSCORRUPTED;
964 }
965
966 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
967 >= le16_to_cpu(curp->p_hdr->eh_max))) {
968 EXT4_ERROR_INODE(inode,
969 "eh_entries %d >= eh_max %d!",
970 le16_to_cpu(curp->p_hdr->eh_entries),
971 le16_to_cpu(curp->p_hdr->eh_max));
972 return -EFSCORRUPTED;
973 }
974
975 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
976 /* insert after */
977 ext_debug("insert new index %d after: %llu\n", logical, ptr);
978 ix = curp->p_idx + 1;
979 } else {
980 /* insert before */
981 ext_debug("insert new index %d before: %llu\n", logical, ptr);
982 ix = curp->p_idx;
983 }
984
985 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
986 BUG_ON(len < 0);
987 if (len > 0) {
988 ext_debug("insert new index %d: "
989 "move %d indices from 0x%p to 0x%p\n",
990 logical, len, ix, ix + 1);
991 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
992 }
993
994 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
995 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
996 return -EFSCORRUPTED;
997 }
998
999 ix->ei_block = cpu_to_le32(logical);
1000 ext4_idx_store_pblock(ix, ptr);
1001 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
1002
1003 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
1004 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
1005 return -EFSCORRUPTED;
1006 }
1007
1008 err = ext4_ext_dirty(handle, inode, curp);
1009 ext4_std_error(inode->i_sb, err);
1010
1011 return err;
1012 }
1013
1014 /*
1015 * ext4_ext_split:
1016 * inserts new subtree into the path, using free index entry
1017 * at depth @at:
1018 * - allocates all needed blocks (new leaf and all intermediate index blocks)
1019 * - makes decision where to split
1020 * - moves remaining extents and index entries (right to the split point)
1021 * into the newly allocated blocks
1022 * - initializes subtree
1023 */
1024 static int ext4_ext_split(handle_t *handle, struct inode *inode,
1025 unsigned int flags,
1026 struct ext4_ext_path *path,
1027 struct ext4_extent *newext, int at)
1028 {
1029 struct buffer_head *bh = NULL;
1030 int depth = ext_depth(inode);
1031 struct ext4_extent_header *neh;
1032 struct ext4_extent_idx *fidx;
1033 int i = at, k, m, a;
1034 ext4_fsblk_t newblock, oldblock;
1035 __le32 border;
1036 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1037 int err = 0;
1038
1039 /* make decision: where to split? */
1040 /* FIXME: now decision is simplest: at current extent */
1041
1042 /* if current leaf will be split, then we should use
1043 * border from split point */
1044 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1045 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1046 return -EFSCORRUPTED;
1047 }
1048 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1049 border = path[depth].p_ext[1].ee_block;
1050 ext_debug("leaf will be split."
1051 " next leaf starts at %d\n",
1052 le32_to_cpu(border));
1053 } else {
1054 border = newext->ee_block;
1055 ext_debug("leaf will be added."
1056 " next leaf starts at %d\n",
1057 le32_to_cpu(border));
1058 }
1059
1060 /*
1061 * If error occurs, then we break processing
1062 * and mark filesystem read-only. index won't
1063 * be inserted and tree will be in consistent
1064 * state. Next mount will repair buffers too.
1065 */
1066
1067 /*
1068 * Get array to track all allocated blocks.
1069 * We need this to handle errors and free blocks
1070 * upon them.
1071 */
1072 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
1073 if (!ablocks)
1074 return -ENOMEM;
1075
1076 /* allocate all needed blocks */
1077 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
1078 for (a = 0; a < depth - at; a++) {
1079 newblock = ext4_ext_new_meta_block(handle, inode, path,
1080 newext, &err, flags);
1081 if (newblock == 0)
1082 goto cleanup;
1083 ablocks[a] = newblock;
1084 }
1085
1086 /* initialize new leaf */
1087 newblock = ablocks[--a];
1088 if (unlikely(newblock == 0)) {
1089 EXT4_ERROR_INODE(inode, "newblock == 0!");
1090 err = -EFSCORRUPTED;
1091 goto cleanup;
1092 }
1093 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1094 if (unlikely(!bh)) {
1095 err = -ENOMEM;
1096 goto cleanup;
1097 }
1098 lock_buffer(bh);
1099
1100 err = ext4_journal_get_create_access(handle, bh);
1101 if (err)
1102 goto cleanup;
1103
1104 neh = ext_block_hdr(bh);
1105 neh->eh_entries = 0;
1106 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1107 neh->eh_magic = EXT4_EXT_MAGIC;
1108 neh->eh_depth = 0;
1109
1110 /* move remainder of path[depth] to the new leaf */
1111 if (unlikely(path[depth].p_hdr->eh_entries !=
1112 path[depth].p_hdr->eh_max)) {
1113 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1114 path[depth].p_hdr->eh_entries,
1115 path[depth].p_hdr->eh_max);
1116 err = -EFSCORRUPTED;
1117 goto cleanup;
1118 }
1119 /* start copy from next extent */
1120 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1121 ext4_ext_show_move(inode, path, newblock, depth);
1122 if (m) {
1123 struct ext4_extent *ex;
1124 ex = EXT_FIRST_EXTENT(neh);
1125 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1126 le16_add_cpu(&neh->eh_entries, m);
1127 }
1128
1129 ext4_extent_block_csum_set(inode, neh);
1130 set_buffer_uptodate(bh);
1131 unlock_buffer(bh);
1132
1133 err = ext4_handle_dirty_metadata(handle, inode, bh);
1134 if (err)
1135 goto cleanup;
1136 brelse(bh);
1137 bh = NULL;
1138
1139 /* correct old leaf */
1140 if (m) {
1141 err = ext4_ext_get_access(handle, inode, path + depth);
1142 if (err)
1143 goto cleanup;
1144 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1145 err = ext4_ext_dirty(handle, inode, path + depth);
1146 if (err)
1147 goto cleanup;
1148
1149 }
1150
1151 /* create intermediate indexes */
1152 k = depth - at - 1;
1153 if (unlikely(k < 0)) {
1154 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1155 err = -EFSCORRUPTED;
1156 goto cleanup;
1157 }
1158 if (k)
1159 ext_debug("create %d intermediate indices\n", k);
1160 /* insert new index into current index block */
1161 /* current depth stored in i var */
1162 i = depth - 1;
1163 while (k--) {
1164 oldblock = newblock;
1165 newblock = ablocks[--a];
1166 bh = sb_getblk(inode->i_sb, newblock);
1167 if (unlikely(!bh)) {
1168 err = -ENOMEM;
1169 goto cleanup;
1170 }
1171 lock_buffer(bh);
1172
1173 err = ext4_journal_get_create_access(handle, bh);
1174 if (err)
1175 goto cleanup;
1176
1177 neh = ext_block_hdr(bh);
1178 neh->eh_entries = cpu_to_le16(1);
1179 neh->eh_magic = EXT4_EXT_MAGIC;
1180 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1181 neh->eh_depth = cpu_to_le16(depth - i);
1182 fidx = EXT_FIRST_INDEX(neh);
1183 fidx->ei_block = border;
1184 ext4_idx_store_pblock(fidx, oldblock);
1185
1186 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1187 i, newblock, le32_to_cpu(border), oldblock);
1188
1189 /* move remainder of path[i] to the new index block */
1190 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1191 EXT_LAST_INDEX(path[i].p_hdr))) {
1192 EXT4_ERROR_INODE(inode,
1193 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1194 le32_to_cpu(path[i].p_ext->ee_block));
1195 err = -EFSCORRUPTED;
1196 goto cleanup;
1197 }
1198 /* start copy indexes */
1199 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1200 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1201 EXT_MAX_INDEX(path[i].p_hdr));
1202 ext4_ext_show_move(inode, path, newblock, i);
1203 if (m) {
1204 memmove(++fidx, path[i].p_idx,
1205 sizeof(struct ext4_extent_idx) * m);
1206 le16_add_cpu(&neh->eh_entries, m);
1207 }
1208 ext4_extent_block_csum_set(inode, neh);
1209 set_buffer_uptodate(bh);
1210 unlock_buffer(bh);
1211
1212 err = ext4_handle_dirty_metadata(handle, inode, bh);
1213 if (err)
1214 goto cleanup;
1215 brelse(bh);
1216 bh = NULL;
1217
1218 /* correct old index */
1219 if (m) {
1220 err = ext4_ext_get_access(handle, inode, path + i);
1221 if (err)
1222 goto cleanup;
1223 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1224 err = ext4_ext_dirty(handle, inode, path + i);
1225 if (err)
1226 goto cleanup;
1227 }
1228
1229 i--;
1230 }
1231
1232 /* insert new index */
1233 err = ext4_ext_insert_index(handle, inode, path + at,
1234 le32_to_cpu(border), newblock);
1235
1236 cleanup:
1237 if (bh) {
1238 if (buffer_locked(bh))
1239 unlock_buffer(bh);
1240 brelse(bh);
1241 }
1242
1243 if (err) {
1244 /* free all allocated blocks in error case */
1245 for (i = 0; i < depth; i++) {
1246 if (!ablocks[i])
1247 continue;
1248 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1249 EXT4_FREE_BLOCKS_METADATA);
1250 }
1251 }
1252 kfree(ablocks);
1253
1254 return err;
1255 }
1256
1257 /*
1258 * ext4_ext_grow_indepth:
1259 * implements tree growing procedure:
1260 * - allocates new block
1261 * - moves top-level data (index block or leaf) into the new block
1262 * - initializes new top-level, creating index that points to the
1263 * just created block
1264 */
1265 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1266 unsigned int flags)
1267 {
1268 struct ext4_extent_header *neh;
1269 struct buffer_head *bh;
1270 ext4_fsblk_t newblock, goal = 0;
1271 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
1272 int err = 0;
1273
1274 /* Try to prepend new index to old one */
1275 if (ext_depth(inode))
1276 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
1277 if (goal > le32_to_cpu(es->s_first_data_block)) {
1278 flags |= EXT4_MB_HINT_TRY_GOAL;
1279 goal--;
1280 } else
1281 goal = ext4_inode_to_goal_block(inode);
1282 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
1283 NULL, &err);
1284 if (newblock == 0)
1285 return err;
1286
1287 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1288 if (unlikely(!bh))
1289 return -ENOMEM;
1290 lock_buffer(bh);
1291
1292 err = ext4_journal_get_create_access(handle, bh);
1293 if (err) {
1294 unlock_buffer(bh);
1295 goto out;
1296 }
1297
1298 /* move top-level index/leaf into new block */
1299 memmove(bh->b_data, EXT4_I(inode)->i_data,
1300 sizeof(EXT4_I(inode)->i_data));
1301
1302 /* set size of new block */
1303 neh = ext_block_hdr(bh);
1304 /* old root could have indexes or leaves
1305 * so calculate e_max right way */
1306 if (ext_depth(inode))
1307 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1308 else
1309 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1310 neh->eh_magic = EXT4_EXT_MAGIC;
1311 ext4_extent_block_csum_set(inode, neh);
1312 set_buffer_uptodate(bh);
1313 unlock_buffer(bh);
1314
1315 err = ext4_handle_dirty_metadata(handle, inode, bh);
1316 if (err)
1317 goto out;
1318
1319 /* Update top-level index: num,max,pointer */
1320 neh = ext_inode_hdr(inode);
1321 neh->eh_entries = cpu_to_le16(1);
1322 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1323 if (neh->eh_depth == 0) {
1324 /* Root extent block becomes index block */
1325 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1326 EXT_FIRST_INDEX(neh)->ei_block =
1327 EXT_FIRST_EXTENT(neh)->ee_block;
1328 }
1329 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1330 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1331 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1332 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1333
1334 le16_add_cpu(&neh->eh_depth, 1);
1335 ext4_mark_inode_dirty(handle, inode);
1336 out:
1337 brelse(bh);
1338
1339 return err;
1340 }
1341
1342 /*
1343 * ext4_ext_create_new_leaf:
1344 * finds empty index and adds new leaf.
1345 * if no free index is found, then it requests in-depth growing.
1346 */
1347 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1348 unsigned int mb_flags,
1349 unsigned int gb_flags,
1350 struct ext4_ext_path **ppath,
1351 struct ext4_extent *newext)
1352 {
1353 struct ext4_ext_path *path = *ppath;
1354 struct ext4_ext_path *curp;
1355 int depth, i, err = 0;
1356
1357 repeat:
1358 i = depth = ext_depth(inode);
1359
1360 /* walk up to the tree and look for free index entry */
1361 curp = path + depth;
1362 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1363 i--;
1364 curp--;
1365 }
1366
1367 /* we use already allocated block for index block,
1368 * so subsequent data blocks should be contiguous */
1369 if (EXT_HAS_FREE_INDEX(curp)) {
1370 /* if we found index with free entry, then use that
1371 * entry: create all needed subtree and add new leaf */
1372 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
1373 if (err)
1374 goto out;
1375
1376 /* refill path */
1377 path = ext4_find_extent(inode,
1378 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1379 ppath, gb_flags);
1380 if (IS_ERR(path))
1381 err = PTR_ERR(path);
1382 } else {
1383 /* tree is full, time to grow in depth */
1384 err = ext4_ext_grow_indepth(handle, inode, mb_flags);
1385 if (err)
1386 goto out;
1387
1388 /* refill path */
1389 path = ext4_find_extent(inode,
1390 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1391 ppath, gb_flags);
1392 if (IS_ERR(path)) {
1393 err = PTR_ERR(path);
1394 goto out;
1395 }
1396
1397 /*
1398 * only first (depth 0 -> 1) produces free space;
1399 * in all other cases we have to split the grown tree
1400 */
1401 depth = ext_depth(inode);
1402 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1403 /* now we need to split */
1404 goto repeat;
1405 }
1406 }
1407
1408 out:
1409 return err;
1410 }
1411
1412 /*
1413 * search the closest allocated block to the left for *logical
1414 * and returns it at @logical + it's physical address at @phys
1415 * if *logical is the smallest allocated block, the function
1416 * returns 0 at @phys
1417 * return value contains 0 (success) or error code
1418 */
1419 static int ext4_ext_search_left(struct inode *inode,
1420 struct ext4_ext_path *path,
1421 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1422 {
1423 struct ext4_extent_idx *ix;
1424 struct ext4_extent *ex;
1425 int depth, ee_len;
1426
1427 if (unlikely(path == NULL)) {
1428 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1429 return -EFSCORRUPTED;
1430 }
1431 depth = path->p_depth;
1432 *phys = 0;
1433
1434 if (depth == 0 && path->p_ext == NULL)
1435 return 0;
1436
1437 /* usually extent in the path covers blocks smaller
1438 * then *logical, but it can be that extent is the
1439 * first one in the file */
1440
1441 ex = path[depth].p_ext;
1442 ee_len = ext4_ext_get_actual_len(ex);
1443 if (*logical < le32_to_cpu(ex->ee_block)) {
1444 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1445 EXT4_ERROR_INODE(inode,
1446 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1447 *logical, le32_to_cpu(ex->ee_block));
1448 return -EFSCORRUPTED;
1449 }
1450 while (--depth >= 0) {
1451 ix = path[depth].p_idx;
1452 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1453 EXT4_ERROR_INODE(inode,
1454 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1455 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1456 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1457 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1458 depth);
1459 return -EFSCORRUPTED;
1460 }
1461 }
1462 return 0;
1463 }
1464
1465 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1466 EXT4_ERROR_INODE(inode,
1467 "logical %d < ee_block %d + ee_len %d!",
1468 *logical, le32_to_cpu(ex->ee_block), ee_len);
1469 return -EFSCORRUPTED;
1470 }
1471
1472 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1473 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1474 return 0;
1475 }
1476
1477 /*
1478 * search the closest allocated block to the right for *logical
1479 * and returns it at @logical + it's physical address at @phys
1480 * if *logical is the largest allocated block, the function
1481 * returns 0 at @phys
1482 * return value contains 0 (success) or error code
1483 */
1484 static int ext4_ext_search_right(struct inode *inode,
1485 struct ext4_ext_path *path,
1486 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1487 struct ext4_extent **ret_ex)
1488 {
1489 struct buffer_head *bh = NULL;
1490 struct ext4_extent_header *eh;
1491 struct ext4_extent_idx *ix;
1492 struct ext4_extent *ex;
1493 ext4_fsblk_t block;
1494 int depth; /* Note, NOT eh_depth; depth from top of tree */
1495 int ee_len;
1496
1497 if (unlikely(path == NULL)) {
1498 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1499 return -EFSCORRUPTED;
1500 }
1501 depth = path->p_depth;
1502 *phys = 0;
1503
1504 if (depth == 0 && path->p_ext == NULL)
1505 return 0;
1506
1507 /* usually extent in the path covers blocks smaller
1508 * then *logical, but it can be that extent is the
1509 * first one in the file */
1510
1511 ex = path[depth].p_ext;
1512 ee_len = ext4_ext_get_actual_len(ex);
1513 if (*logical < le32_to_cpu(ex->ee_block)) {
1514 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1515 EXT4_ERROR_INODE(inode,
1516 "first_extent(path[%d].p_hdr) != ex",
1517 depth);
1518 return -EFSCORRUPTED;
1519 }
1520 while (--depth >= 0) {
1521 ix = path[depth].p_idx;
1522 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1523 EXT4_ERROR_INODE(inode,
1524 "ix != EXT_FIRST_INDEX *logical %d!",
1525 *logical);
1526 return -EFSCORRUPTED;
1527 }
1528 }
1529 goto found_extent;
1530 }
1531
1532 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1533 EXT4_ERROR_INODE(inode,
1534 "logical %d < ee_block %d + ee_len %d!",
1535 *logical, le32_to_cpu(ex->ee_block), ee_len);
1536 return -EFSCORRUPTED;
1537 }
1538
1539 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1540 /* next allocated block in this leaf */
1541 ex++;
1542 goto found_extent;
1543 }
1544
1545 /* go up and search for index to the right */
1546 while (--depth >= 0) {
1547 ix = path[depth].p_idx;
1548 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1549 goto got_index;
1550 }
1551
1552 /* we've gone up to the root and found no index to the right */
1553 return 0;
1554
1555 got_index:
1556 /* we've found index to the right, let's
1557 * follow it and find the closest allocated
1558 * block to the right */
1559 ix++;
1560 block = ext4_idx_pblock(ix);
1561 while (++depth < path->p_depth) {
1562 /* subtract from p_depth to get proper eh_depth */
1563 bh = read_extent_tree_block(inode, block,
1564 path->p_depth - depth, 0);
1565 if (IS_ERR(bh))
1566 return PTR_ERR(bh);
1567 eh = ext_block_hdr(bh);
1568 ix = EXT_FIRST_INDEX(eh);
1569 block = ext4_idx_pblock(ix);
1570 put_bh(bh);
1571 }
1572
1573 bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0);
1574 if (IS_ERR(bh))
1575 return PTR_ERR(bh);
1576 eh = ext_block_hdr(bh);
1577 ex = EXT_FIRST_EXTENT(eh);
1578 found_extent:
1579 *logical = le32_to_cpu(ex->ee_block);
1580 *phys = ext4_ext_pblock(ex);
1581 *ret_ex = ex;
1582 if (bh)
1583 put_bh(bh);
1584 return 0;
1585 }
1586
1587 /*
1588 * ext4_ext_next_allocated_block:
1589 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1590 * NOTE: it considers block number from index entry as
1591 * allocated block. Thus, index entries have to be consistent
1592 * with leaves.
1593 */
1594 ext4_lblk_t
1595 ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1596 {
1597 int depth;
1598
1599 BUG_ON(path == NULL);
1600 depth = path->p_depth;
1601
1602 if (depth == 0 && path->p_ext == NULL)
1603 return EXT_MAX_BLOCKS;
1604
1605 while (depth >= 0) {
1606 if (depth == path->p_depth) {
1607 /* leaf */
1608 if (path[depth].p_ext &&
1609 path[depth].p_ext !=
1610 EXT_LAST_EXTENT(path[depth].p_hdr))
1611 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1612 } else {
1613 /* index */
1614 if (path[depth].p_idx !=
1615 EXT_LAST_INDEX(path[depth].p_hdr))
1616 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1617 }
1618 depth--;
1619 }
1620
1621 return EXT_MAX_BLOCKS;
1622 }
1623
1624 /*
1625 * ext4_ext_next_leaf_block:
1626 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1627 */
1628 static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1629 {
1630 int depth;
1631
1632 BUG_ON(path == NULL);
1633 depth = path->p_depth;
1634
1635 /* zero-tree has no leaf blocks at all */
1636 if (depth == 0)
1637 return EXT_MAX_BLOCKS;
1638
1639 /* go to index block */
1640 depth--;
1641
1642 while (depth >= 0) {
1643 if (path[depth].p_idx !=
1644 EXT_LAST_INDEX(path[depth].p_hdr))
1645 return (ext4_lblk_t)
1646 le32_to_cpu(path[depth].p_idx[1].ei_block);
1647 depth--;
1648 }
1649
1650 return EXT_MAX_BLOCKS;
1651 }
1652
1653 /*
1654 * ext4_ext_correct_indexes:
1655 * if leaf gets modified and modified extent is first in the leaf,
1656 * then we have to correct all indexes above.
1657 * TODO: do we need to correct tree in all cases?
1658 */
1659 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1660 struct ext4_ext_path *path)
1661 {
1662 struct ext4_extent_header *eh;
1663 int depth = ext_depth(inode);
1664 struct ext4_extent *ex;
1665 __le32 border;
1666 int k, err = 0;
1667
1668 eh = path[depth].p_hdr;
1669 ex = path[depth].p_ext;
1670
1671 if (unlikely(ex == NULL || eh == NULL)) {
1672 EXT4_ERROR_INODE(inode,
1673 "ex %p == NULL or eh %p == NULL", ex, eh);
1674 return -EFSCORRUPTED;
1675 }
1676
1677 if (depth == 0) {
1678 /* there is no tree at all */
1679 return 0;
1680 }
1681
1682 if (ex != EXT_FIRST_EXTENT(eh)) {
1683 /* we correct tree if first leaf got modified only */
1684 return 0;
1685 }
1686
1687 /*
1688 * TODO: we need correction if border is smaller than current one
1689 */
1690 k = depth - 1;
1691 border = path[depth].p_ext->ee_block;
1692 err = ext4_ext_get_access(handle, inode, path + k);
1693 if (err)
1694 return err;
1695 path[k].p_idx->ei_block = border;
1696 err = ext4_ext_dirty(handle, inode, path + k);
1697 if (err)
1698 return err;
1699
1700 while (k--) {
1701 /* change all left-side indexes */
1702 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1703 break;
1704 err = ext4_ext_get_access(handle, inode, path + k);
1705 if (err)
1706 break;
1707 path[k].p_idx->ei_block = border;
1708 err = ext4_ext_dirty(handle, inode, path + k);
1709 if (err)
1710 break;
1711 }
1712
1713 return err;
1714 }
1715
1716 int
1717 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1718 struct ext4_extent *ex2)
1719 {
1720 unsigned short ext1_ee_len, ext2_ee_len;
1721
1722 if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
1723 return 0;
1724
1725 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1726 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1727
1728 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1729 le32_to_cpu(ex2->ee_block))
1730 return 0;
1731
1732 /*
1733 * To allow future support for preallocated extents to be added
1734 * as an RO_COMPAT feature, refuse to merge to extents if
1735 * this can result in the top bit of ee_len being set.
1736 */
1737 if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1738 return 0;
1739 if (ext4_ext_is_unwritten(ex1) &&
1740 (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) ||
1741 atomic_read(&EXT4_I(inode)->i_unwritten) ||
1742 (ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)))
1743 return 0;
1744 #ifdef AGGRESSIVE_TEST
1745 if (ext1_ee_len >= 4)
1746 return 0;
1747 #endif
1748
1749 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1750 return 1;
1751 return 0;
1752 }
1753
1754 /*
1755 * This function tries to merge the "ex" extent to the next extent in the tree.
1756 * It always tries to merge towards right. If you want to merge towards
1757 * left, pass "ex - 1" as argument instead of "ex".
1758 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1759 * 1 if they got merged.
1760 */
1761 static int ext4_ext_try_to_merge_right(struct inode *inode,
1762 struct ext4_ext_path *path,
1763 struct ext4_extent *ex)
1764 {
1765 struct ext4_extent_header *eh;
1766 unsigned int depth, len;
1767 int merge_done = 0, unwritten;
1768
1769 depth = ext_depth(inode);
1770 BUG_ON(path[depth].p_hdr == NULL);
1771 eh = path[depth].p_hdr;
1772
1773 while (ex < EXT_LAST_EXTENT(eh)) {
1774 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1775 break;
1776 /* merge with next extent! */
1777 unwritten = ext4_ext_is_unwritten(ex);
1778 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1779 + ext4_ext_get_actual_len(ex + 1));
1780 if (unwritten)
1781 ext4_ext_mark_unwritten(ex);
1782
1783 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1784 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1785 * sizeof(struct ext4_extent);
1786 memmove(ex + 1, ex + 2, len);
1787 }
1788 le16_add_cpu(&eh->eh_entries, -1);
1789 merge_done = 1;
1790 WARN_ON(eh->eh_entries == 0);
1791 if (!eh->eh_entries)
1792 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1793 }
1794
1795 return merge_done;
1796 }
1797
1798 /*
1799 * This function does a very simple check to see if we can collapse
1800 * an extent tree with a single extent tree leaf block into the inode.
1801 */
1802 static void ext4_ext_try_to_merge_up(handle_t *handle,
1803 struct inode *inode,
1804 struct ext4_ext_path *path)
1805 {
1806 size_t s;
1807 unsigned max_root = ext4_ext_space_root(inode, 0);
1808 ext4_fsblk_t blk;
1809
1810 if ((path[0].p_depth != 1) ||
1811 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1812 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1813 return;
1814
1815 /*
1816 * We need to modify the block allocation bitmap and the block
1817 * group descriptor to release the extent tree block. If we
1818 * can't get the journal credits, give up.
1819 */
1820 if (ext4_journal_extend(handle, 2))
1821 return;
1822
1823 /*
1824 * Copy the extent data up to the inode
1825 */
1826 blk = ext4_idx_pblock(path[0].p_idx);
1827 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1828 sizeof(struct ext4_extent_idx);
1829 s += sizeof(struct ext4_extent_header);
1830
1831 path[1].p_maxdepth = path[0].p_maxdepth;
1832 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1833 path[0].p_depth = 0;
1834 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1835 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1836 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1837
1838 brelse(path[1].p_bh);
1839 ext4_free_blocks(handle, inode, NULL, blk, 1,
1840 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1841 }
1842
1843 /*
1844 * This function tries to merge the @ex extent to neighbours in the tree.
1845 * return 1 if merge left else 0.
1846 */
1847 static void ext4_ext_try_to_merge(handle_t *handle,
1848 struct inode *inode,
1849 struct ext4_ext_path *path,
1850 struct ext4_extent *ex) {
1851 struct ext4_extent_header *eh;
1852 unsigned int depth;
1853 int merge_done = 0;
1854
1855 depth = ext_depth(inode);
1856 BUG_ON(path[depth].p_hdr == NULL);
1857 eh = path[depth].p_hdr;
1858
1859 if (ex > EXT_FIRST_EXTENT(eh))
1860 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1861
1862 if (!merge_done)
1863 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1864
1865 ext4_ext_try_to_merge_up(handle, inode, path);
1866 }
1867
1868 /*
1869 * check if a portion of the "newext" extent overlaps with an
1870 * existing extent.
1871 *
1872 * If there is an overlap discovered, it updates the length of the newext
1873 * such that there will be no overlap, and then returns 1.
1874 * If there is no overlap found, it returns 0.
1875 */
1876 static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1877 struct inode *inode,
1878 struct ext4_extent *newext,
1879 struct ext4_ext_path *path)
1880 {
1881 ext4_lblk_t b1, b2;
1882 unsigned int depth, len1;
1883 unsigned int ret = 0;
1884
1885 b1 = le32_to_cpu(newext->ee_block);
1886 len1 = ext4_ext_get_actual_len(newext);
1887 depth = ext_depth(inode);
1888 if (!path[depth].p_ext)
1889 goto out;
1890 b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
1891
1892 /*
1893 * get the next allocated block if the extent in the path
1894 * is before the requested block(s)
1895 */
1896 if (b2 < b1) {
1897 b2 = ext4_ext_next_allocated_block(path);
1898 if (b2 == EXT_MAX_BLOCKS)
1899 goto out;
1900 b2 = EXT4_LBLK_CMASK(sbi, b2);
1901 }
1902
1903 /* check for wrap through zero on extent logical start block*/
1904 if (b1 + len1 < b1) {
1905 len1 = EXT_MAX_BLOCKS - b1;
1906 newext->ee_len = cpu_to_le16(len1);
1907 ret = 1;
1908 }
1909
1910 /* check for overlap */
1911 if (b1 + len1 > b2) {
1912 newext->ee_len = cpu_to_le16(b2 - b1);
1913 ret = 1;
1914 }
1915 out:
1916 return ret;
1917 }
1918
1919 /*
1920 * ext4_ext_insert_extent:
1921 * tries to merge requsted extent into the existing extent or
1922 * inserts requested extent as new one into the tree,
1923 * creating new leaf in the no-space case.
1924 */
1925 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1926 struct ext4_ext_path **ppath,
1927 struct ext4_extent *newext, int gb_flags)
1928 {
1929 struct ext4_ext_path *path = *ppath;
1930 struct ext4_extent_header *eh;
1931 struct ext4_extent *ex, *fex;
1932 struct ext4_extent *nearex; /* nearest extent */
1933 struct ext4_ext_path *npath = NULL;
1934 int depth, len, err;
1935 ext4_lblk_t next;
1936 int mb_flags = 0, unwritten;
1937
1938 if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1939 mb_flags |= EXT4_MB_DELALLOC_RESERVED;
1940 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1941 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1942 return -EFSCORRUPTED;
1943 }
1944 depth = ext_depth(inode);
1945 ex = path[depth].p_ext;
1946 eh = path[depth].p_hdr;
1947 if (unlikely(path[depth].p_hdr == NULL)) {
1948 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1949 return -EFSCORRUPTED;
1950 }
1951
1952 /* try to insert block into found extent and return */
1953 if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
1954
1955 /*
1956 * Try to see whether we should rather test the extent on
1957 * right from ex, or from the left of ex. This is because
1958 * ext4_find_extent() can return either extent on the
1959 * left, or on the right from the searched position. This
1960 * will make merging more effective.
1961 */
1962 if (ex < EXT_LAST_EXTENT(eh) &&
1963 (le32_to_cpu(ex->ee_block) +
1964 ext4_ext_get_actual_len(ex) <
1965 le32_to_cpu(newext->ee_block))) {
1966 ex += 1;
1967 goto prepend;
1968 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
1969 (le32_to_cpu(newext->ee_block) +
1970 ext4_ext_get_actual_len(newext) <
1971 le32_to_cpu(ex->ee_block)))
1972 ex -= 1;
1973
1974 /* Try to append newex to the ex */
1975 if (ext4_can_extents_be_merged(inode, ex, newext)) {
1976 ext_debug("append [%d]%d block to %u:[%d]%d"
1977 "(from %llu)\n",
1978 ext4_ext_is_unwritten(newext),
1979 ext4_ext_get_actual_len(newext),
1980 le32_to_cpu(ex->ee_block),
1981 ext4_ext_is_unwritten(ex),
1982 ext4_ext_get_actual_len(ex),
1983 ext4_ext_pblock(ex));
1984 err = ext4_ext_get_access(handle, inode,
1985 path + depth);
1986 if (err)
1987 return err;
1988 unwritten = ext4_ext_is_unwritten(ex);
1989 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1990 + ext4_ext_get_actual_len(newext));
1991 if (unwritten)
1992 ext4_ext_mark_unwritten(ex);
1993 eh = path[depth].p_hdr;
1994 nearex = ex;
1995 goto merge;
1996 }
1997
1998 prepend:
1999 /* Try to prepend newex to the ex */
2000 if (ext4_can_extents_be_merged(inode, newext, ex)) {
2001 ext_debug("prepend %u[%d]%d block to %u:[%d]%d"
2002 "(from %llu)\n",
2003 le32_to_cpu(newext->ee_block),
2004 ext4_ext_is_unwritten(newext),
2005 ext4_ext_get_actual_len(newext),
2006 le32_to_cpu(ex->ee_block),
2007 ext4_ext_is_unwritten(ex),
2008 ext4_ext_get_actual_len(ex),
2009 ext4_ext_pblock(ex));
2010 err = ext4_ext_get_access(handle, inode,
2011 path + depth);
2012 if (err)
2013 return err;
2014
2015 unwritten = ext4_ext_is_unwritten(ex);
2016 ex->ee_block = newext->ee_block;
2017 ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
2018 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2019 + ext4_ext_get_actual_len(newext));
2020 if (unwritten)
2021 ext4_ext_mark_unwritten(ex);
2022 eh = path[depth].p_hdr;
2023 nearex = ex;
2024 goto merge;
2025 }
2026 }
2027
2028 depth = ext_depth(inode);
2029 eh = path[depth].p_hdr;
2030 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
2031 goto has_space;
2032
2033 /* probably next leaf has space for us? */
2034 fex = EXT_LAST_EXTENT(eh);
2035 next = EXT_MAX_BLOCKS;
2036 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
2037 next = ext4_ext_next_leaf_block(path);
2038 if (next != EXT_MAX_BLOCKS) {
2039 ext_debug("next leaf block - %u\n", next);
2040 BUG_ON(npath != NULL);
2041 npath = ext4_find_extent(inode, next, NULL, 0);
2042 if (IS_ERR(npath))
2043 return PTR_ERR(npath);
2044 BUG_ON(npath->p_depth != path->p_depth);
2045 eh = npath[depth].p_hdr;
2046 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2047 ext_debug("next leaf isn't full(%d)\n",
2048 le16_to_cpu(eh->eh_entries));
2049 path = npath;
2050 goto has_space;
2051 }
2052 ext_debug("next leaf has no free space(%d,%d)\n",
2053 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2054 }
2055
2056 /*
2057 * There is no free space in the found leaf.
2058 * We're gonna add a new leaf in the tree.
2059 */
2060 if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2061 mb_flags |= EXT4_MB_USE_RESERVED;
2062 err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2063 ppath, newext);
2064 if (err)
2065 goto cleanup;
2066 depth = ext_depth(inode);
2067 eh = path[depth].p_hdr;
2068
2069 has_space:
2070 nearex = path[depth].p_ext;
2071
2072 err = ext4_ext_get_access(handle, inode, path + depth);
2073 if (err)
2074 goto cleanup;
2075
2076 if (!nearex) {
2077 /* there is no extent in this leaf, create first one */
2078 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
2079 le32_to_cpu(newext->ee_block),
2080 ext4_ext_pblock(newext),
2081 ext4_ext_is_unwritten(newext),
2082 ext4_ext_get_actual_len(newext));
2083 nearex = EXT_FIRST_EXTENT(eh);
2084 } else {
2085 if (le32_to_cpu(newext->ee_block)
2086 > le32_to_cpu(nearex->ee_block)) {
2087 /* Insert after */
2088 ext_debug("insert %u:%llu:[%d]%d before: "
2089 "nearest %p\n",
2090 le32_to_cpu(newext->ee_block),
2091 ext4_ext_pblock(newext),
2092 ext4_ext_is_unwritten(newext),
2093 ext4_ext_get_actual_len(newext),
2094 nearex);
2095 nearex++;
2096 } else {
2097 /* Insert before */
2098 BUG_ON(newext->ee_block == nearex->ee_block);
2099 ext_debug("insert %u:%llu:[%d]%d after: "
2100 "nearest %p\n",
2101 le32_to_cpu(newext->ee_block),
2102 ext4_ext_pblock(newext),
2103 ext4_ext_is_unwritten(newext),
2104 ext4_ext_get_actual_len(newext),
2105 nearex);
2106 }
2107 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2108 if (len > 0) {
2109 ext_debug("insert %u:%llu:[%d]%d: "
2110 "move %d extents from 0x%p to 0x%p\n",
2111 le32_to_cpu(newext->ee_block),
2112 ext4_ext_pblock(newext),
2113 ext4_ext_is_unwritten(newext),
2114 ext4_ext_get_actual_len(newext),
2115 len, nearex, nearex + 1);
2116 memmove(nearex + 1, nearex,
2117 len * sizeof(struct ext4_extent));
2118 }
2119 }
2120
2121 le16_add_cpu(&eh->eh_entries, 1);
2122 path[depth].p_ext = nearex;
2123 nearex->ee_block = newext->ee_block;
2124 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2125 nearex->ee_len = newext->ee_len;
2126
2127 merge:
2128 /* try to merge extents */
2129 if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2130 ext4_ext_try_to_merge(handle, inode, path, nearex);
2131
2132
2133 /* time to correct all indexes above */
2134 err = ext4_ext_correct_indexes(handle, inode, path);
2135 if (err)
2136 goto cleanup;
2137
2138 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2139
2140 cleanup:
2141 ext4_ext_drop_refs(npath);
2142 kfree(npath);
2143 return err;
2144 }
2145
2146 static int ext4_fill_fiemap_extents(struct inode *inode,
2147 ext4_lblk_t block, ext4_lblk_t num,
2148 struct fiemap_extent_info *fieinfo)
2149 {
2150 struct ext4_ext_path *path = NULL;
2151 struct ext4_extent *ex;
2152 struct extent_status es;
2153 ext4_lblk_t next, next_del, start = 0, end = 0;
2154 ext4_lblk_t last = block + num;
2155 int exists, depth = 0, err = 0;
2156 unsigned int flags = 0;
2157 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2158
2159 while (block < last && block != EXT_MAX_BLOCKS) {
2160 num = last - block;
2161 /* find extent for this block */
2162 down_read(&EXT4_I(inode)->i_data_sem);
2163
2164 path = ext4_find_extent(inode, block, &path, 0);
2165 if (IS_ERR(path)) {
2166 up_read(&EXT4_I(inode)->i_data_sem);
2167 err = PTR_ERR(path);
2168 path = NULL;
2169 break;
2170 }
2171
2172 depth = ext_depth(inode);
2173 if (unlikely(path[depth].p_hdr == NULL)) {
2174 up_read(&EXT4_I(inode)->i_data_sem);
2175 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2176 err = -EFSCORRUPTED;
2177 break;
2178 }
2179 ex = path[depth].p_ext;
2180 next = ext4_ext_next_allocated_block(path);
2181
2182 flags = 0;
2183 exists = 0;
2184 if (!ex) {
2185 /* there is no extent yet, so try to allocate
2186 * all requested space */
2187 start = block;
2188 end = block + num;
2189 } else if (le32_to_cpu(ex->ee_block) > block) {
2190 /* need to allocate space before found extent */
2191 start = block;
2192 end = le32_to_cpu(ex->ee_block);
2193 if (block + num < end)
2194 end = block + num;
2195 } else if (block >= le32_to_cpu(ex->ee_block)
2196 + ext4_ext_get_actual_len(ex)) {
2197 /* need to allocate space after found extent */
2198 start = block;
2199 end = block + num;
2200 if (end >= next)
2201 end = next;
2202 } else if (block >= le32_to_cpu(ex->ee_block)) {
2203 /*
2204 * some part of requested space is covered
2205 * by found extent
2206 */
2207 start = block;
2208 end = le32_to_cpu(ex->ee_block)
2209 + ext4_ext_get_actual_len(ex);
2210 if (block + num < end)
2211 end = block + num;
2212 exists = 1;
2213 } else {
2214 BUG();
2215 }
2216 BUG_ON(end <= start);
2217
2218 if (!exists) {
2219 es.es_lblk = start;
2220 es.es_len = end - start;
2221 es.es_pblk = 0;
2222 } else {
2223 es.es_lblk = le32_to_cpu(ex->ee_block);
2224 es.es_len = ext4_ext_get_actual_len(ex);
2225 es.es_pblk = ext4_ext_pblock(ex);
2226 if (ext4_ext_is_unwritten(ex))
2227 flags |= FIEMAP_EXTENT_UNWRITTEN;
2228 }
2229
2230 /*
2231 * Find delayed extent and update es accordingly. We call
2232 * it even in !exists case to find out whether es is the
2233 * last existing extent or not.
2234 */
2235 next_del = ext4_find_delayed_extent(inode, &es);
2236 if (!exists && next_del) {
2237 exists = 1;
2238 flags |= (FIEMAP_EXTENT_DELALLOC |
2239 FIEMAP_EXTENT_UNKNOWN);
2240 }
2241 up_read(&EXT4_I(inode)->i_data_sem);
2242
2243 if (unlikely(es.es_len == 0)) {
2244 EXT4_ERROR_INODE(inode, "es.es_len == 0");
2245 err = -EFSCORRUPTED;
2246 break;
2247 }
2248
2249 /*
2250 * This is possible iff next == next_del == EXT_MAX_BLOCKS.
2251 * we need to check next == EXT_MAX_BLOCKS because it is
2252 * possible that an extent is with unwritten and delayed
2253 * status due to when an extent is delayed allocated and
2254 * is allocated by fallocate status tree will track both of
2255 * them in a extent.
2256 *
2257 * So we could return a unwritten and delayed extent, and
2258 * its block is equal to 'next'.
2259 */
2260 if (next == next_del && next == EXT_MAX_BLOCKS) {
2261 flags |= FIEMAP_EXTENT_LAST;
2262 if (unlikely(next_del != EXT_MAX_BLOCKS ||
2263 next != EXT_MAX_BLOCKS)) {
2264 EXT4_ERROR_INODE(inode,
2265 "next extent == %u, next "
2266 "delalloc extent = %u",
2267 next, next_del);
2268 err = -EFSCORRUPTED;
2269 break;
2270 }
2271 }
2272
2273 if (exists) {
2274 err = fiemap_fill_next_extent(fieinfo,
2275 (__u64)es.es_lblk << blksize_bits,
2276 (__u64)es.es_pblk << blksize_bits,
2277 (__u64)es.es_len << blksize_bits,
2278 flags);
2279 if (err < 0)
2280 break;
2281 if (err == 1) {
2282 err = 0;
2283 break;
2284 }
2285 }
2286
2287 block = es.es_lblk + es.es_len;
2288 }
2289
2290 ext4_ext_drop_refs(path);
2291 kfree(path);
2292 return err;
2293 }
2294
2295 /*
2296 * ext4_ext_put_gap_in_cache:
2297 * calculate boundaries of the gap that the requested block fits into
2298 * and cache this gap
2299 */
2300 static void
2301 ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
2302 ext4_lblk_t block)
2303 {
2304 int depth = ext_depth(inode);
2305 ext4_lblk_t len;
2306 ext4_lblk_t lblock;
2307 struct ext4_extent *ex;
2308 struct extent_status es;
2309
2310 ex = path[depth].p_ext;
2311 if (ex == NULL) {
2312 /* there is no extent yet, so gap is [0;-] */
2313 lblock = 0;
2314 len = EXT_MAX_BLOCKS;
2315 ext_debug("cache gap(whole file):");
2316 } else if (block < le32_to_cpu(ex->ee_block)) {
2317 lblock = block;
2318 len = le32_to_cpu(ex->ee_block) - block;
2319 ext_debug("cache gap(before): %u [%u:%u]",
2320 block,
2321 le32_to_cpu(ex->ee_block),
2322 ext4_ext_get_actual_len(ex));
2323 } else if (block >= le32_to_cpu(ex->ee_block)
2324 + ext4_ext_get_actual_len(ex)) {
2325 ext4_lblk_t next;
2326 lblock = le32_to_cpu(ex->ee_block)
2327 + ext4_ext_get_actual_len(ex);
2328
2329 next = ext4_ext_next_allocated_block(path);
2330 ext_debug("cache gap(after): [%u:%u] %u",
2331 le32_to_cpu(ex->ee_block),
2332 ext4_ext_get_actual_len(ex),
2333 block);
2334 BUG_ON(next == lblock);
2335 len = next - lblock;
2336 } else {
2337 BUG();
2338 }
2339
2340 ext4_es_find_delayed_extent_range(inode, lblock, lblock + len - 1, &es);
2341 if (es.es_len) {
2342 /* There's delayed extent containing lblock? */
2343 if (es.es_lblk <= lblock)
2344 return;
2345 len = min(es.es_lblk - lblock, len);
2346 }
2347 ext_debug(" -> %u:%u\n", lblock, len);
2348 ext4_es_insert_extent(inode, lblock, len, ~0, EXTENT_STATUS_HOLE);
2349 }
2350
2351 /*
2352 * ext4_ext_rm_idx:
2353 * removes index from the index block.
2354 */
2355 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2356 struct ext4_ext_path *path, int depth)
2357 {
2358 int err;
2359 ext4_fsblk_t leaf;
2360
2361 /* free index block */
2362 depth--;
2363 path = path + depth;
2364 leaf = ext4_idx_pblock(path->p_idx);
2365 if (unlikely(path->p_hdr->eh_entries == 0)) {
2366 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2367 return -EFSCORRUPTED;
2368 }
2369 err = ext4_ext_get_access(handle, inode, path);
2370 if (err)
2371 return err;
2372
2373 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2374 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2375 len *= sizeof(struct ext4_extent_idx);
2376 memmove(path->p_idx, path->p_idx + 1, len);
2377 }
2378
2379 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2380 err = ext4_ext_dirty(handle, inode, path);
2381 if (err)
2382 return err;
2383 ext_debug("index is empty, remove it, free block %llu\n", leaf);
2384 trace_ext4_ext_rm_idx(inode, leaf);
2385
2386 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2387 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2388
2389 while (--depth >= 0) {
2390 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2391 break;
2392 path--;
2393 err = ext4_ext_get_access(handle, inode, path);
2394 if (err)
2395 break;
2396 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2397 err = ext4_ext_dirty(handle, inode, path);
2398 if (err)
2399 break;
2400 }
2401 return err;
2402 }
2403
2404 /*
2405 * ext4_ext_calc_credits_for_single_extent:
2406 * This routine returns max. credits that needed to insert an extent
2407 * to the extent tree.
2408 * When pass the actual path, the caller should calculate credits
2409 * under i_data_sem.
2410 */
2411 int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2412 struct ext4_ext_path *path)
2413 {
2414 if (path) {
2415 int depth = ext_depth(inode);
2416 int ret = 0;
2417
2418 /* probably there is space in leaf? */
2419 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2420 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2421
2422 /*
2423 * There are some space in the leaf tree, no
2424 * need to account for leaf block credit
2425 *
2426 * bitmaps and block group descriptor blocks
2427 * and other metadata blocks still need to be
2428 * accounted.
2429 */
2430 /* 1 bitmap, 1 block group descriptor */
2431 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2432 return ret;
2433 }
2434 }
2435
2436 return ext4_chunk_trans_blocks(inode, nrblocks);
2437 }
2438
2439 /*
2440 * How many index/leaf blocks need to change/allocate to add @extents extents?
2441 *
2442 * If we add a single extent, then in the worse case, each tree level
2443 * index/leaf need to be changed in case of the tree split.
2444 *
2445 * If more extents are inserted, they could cause the whole tree split more
2446 * than once, but this is really rare.
2447 */
2448 int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2449 {
2450 int index;
2451 int depth;
2452
2453 /* If we are converting the inline data, only one is needed here. */
2454 if (ext4_has_inline_data(inode))
2455 return 1;
2456
2457 depth = ext_depth(inode);
2458
2459 if (extents <= 1)
2460 index = depth * 2;
2461 else
2462 index = depth * 3;
2463
2464 return index;
2465 }
2466
2467 static inline int get_default_free_blocks_flags(struct inode *inode)
2468 {
2469 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2470 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2471 else if (ext4_should_journal_data(inode))
2472 return EXT4_FREE_BLOCKS_FORGET;
2473 return 0;
2474 }
2475
2476 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2477 struct ext4_extent *ex,
2478 long long *partial_cluster,
2479 ext4_lblk_t from, ext4_lblk_t to)
2480 {
2481 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2482 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2483 ext4_fsblk_t pblk;
2484 int flags = get_default_free_blocks_flags(inode);
2485
2486 /*
2487 * For bigalloc file systems, we never free a partial cluster
2488 * at the beginning of the extent. Instead, we make a note
2489 * that we tried freeing the cluster, and check to see if we
2490 * need to free it on a subsequent call to ext4_remove_blocks,
2491 * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
2492 */
2493 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2494
2495 trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2496 /*
2497 * If we have a partial cluster, and it's different from the
2498 * cluster of the last block, we need to explicitly free the
2499 * partial cluster here.
2500 */
2501 pblk = ext4_ext_pblock(ex) + ee_len - 1;
2502 if (*partial_cluster > 0 &&
2503 *partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2504 ext4_free_blocks(handle, inode, NULL,
2505 EXT4_C2B(sbi, *partial_cluster),
2506 sbi->s_cluster_ratio, flags);
2507 *partial_cluster = 0;
2508 }
2509
2510 #ifdef EXTENTS_STATS
2511 {
2512 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2513 spin_lock(&sbi->s_ext_stats_lock);
2514 sbi->s_ext_blocks += ee_len;
2515 sbi->s_ext_extents++;
2516 if (ee_len < sbi->s_ext_min)
2517 sbi->s_ext_min = ee_len;
2518 if (ee_len > sbi->s_ext_max)
2519 sbi->s_ext_max = ee_len;
2520 if (ext_depth(inode) > sbi->s_depth_max)
2521 sbi->s_depth_max = ext_depth(inode);
2522 spin_unlock(&sbi->s_ext_stats_lock);
2523 }
2524 #endif
2525 if (from >= le32_to_cpu(ex->ee_block)
2526 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2527 /* tail removal */
2528 ext4_lblk_t num;
2529 long long first_cluster;
2530
2531 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2532 pblk = ext4_ext_pblock(ex) + ee_len - num;
2533 /*
2534 * Usually we want to free partial cluster at the end of the
2535 * extent, except for the situation when the cluster is still
2536 * used by any other extent (partial_cluster is negative).
2537 */
2538 if (*partial_cluster < 0 &&
2539 *partial_cluster == -(long long) EXT4_B2C(sbi, pblk+num-1))
2540 flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2541
2542 ext_debug("free last %u blocks starting %llu partial %lld\n",
2543 num, pblk, *partial_cluster);
2544 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2545 /*
2546 * If the block range to be freed didn't start at the
2547 * beginning of a cluster, and we removed the entire
2548 * extent and the cluster is not used by any other extent,
2549 * save the partial cluster here, since we might need to
2550 * delete if we determine that the truncate or punch hole
2551 * operation has removed all of the blocks in the cluster.
2552 * If that cluster is used by another extent, preserve its
2553 * negative value so it isn't freed later on.
2554 *
2555 * If the whole extent wasn't freed, we've reached the
2556 * start of the truncated/punched region and have finished
2557 * removing blocks. If there's a partial cluster here it's
2558 * shared with the remainder of the extent and is no longer
2559 * a candidate for removal.
2560 */
2561 if (EXT4_PBLK_COFF(sbi, pblk) && ee_len == num) {
2562 first_cluster = (long long) EXT4_B2C(sbi, pblk);
2563 if (first_cluster != -*partial_cluster)
2564 *partial_cluster = first_cluster;
2565 } else {
2566 *partial_cluster = 0;
2567 }
2568 } else
2569 ext4_error(sbi->s_sb, "strange request: removal(2) "
2570 "%u-%u from %u:%u\n",
2571 from, to, le32_to_cpu(ex->ee_block), ee_len);
2572 return 0;
2573 }
2574
2575
2576 /*
2577 * ext4_ext_rm_leaf() Removes the extents associated with the
2578 * blocks appearing between "start" and "end". Both "start"
2579 * and "end" must appear in the same extent or EIO is returned.
2580 *
2581 * @handle: The journal handle
2582 * @inode: The files inode
2583 * @path: The path to the leaf
2584 * @partial_cluster: The cluster which we'll have to free if all extents
2585 * has been released from it. However, if this value is
2586 * negative, it's a cluster just to the right of the
2587 * punched region and it must not be freed.
2588 * @start: The first block to remove
2589 * @end: The last block to remove
2590 */
2591 static int
2592 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2593 struct ext4_ext_path *path,
2594 long long *partial_cluster,
2595 ext4_lblk_t start, ext4_lblk_t end)
2596 {
2597 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2598 int err = 0, correct_index = 0;
2599 int depth = ext_depth(inode), credits;
2600 struct ext4_extent_header *eh;
2601 ext4_lblk_t a, b;
2602 unsigned num;
2603 ext4_lblk_t ex_ee_block;
2604 unsigned short ex_ee_len;
2605 unsigned unwritten = 0;
2606 struct ext4_extent *ex;
2607 ext4_fsblk_t pblk;
2608
2609 /* the header must be checked already in ext4_ext_remove_space() */
2610 ext_debug("truncate since %u in leaf to %u\n", start, end);
2611 if (!path[depth].p_hdr)
2612 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2613 eh = path[depth].p_hdr;
2614 if (unlikely(path[depth].p_hdr == NULL)) {
2615 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2616 return -EFSCORRUPTED;
2617 }
2618 /* find where to start removing */
2619 ex = path[depth].p_ext;
2620 if (!ex)
2621 ex = EXT_LAST_EXTENT(eh);
2622
2623 ex_ee_block = le32_to_cpu(ex->ee_block);
2624 ex_ee_len = ext4_ext_get_actual_len(ex);
2625
2626 trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2627
2628 while (ex >= EXT_FIRST_EXTENT(eh) &&
2629 ex_ee_block + ex_ee_len > start) {
2630
2631 if (ext4_ext_is_unwritten(ex))
2632 unwritten = 1;
2633 else
2634 unwritten = 0;
2635
2636 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2637 unwritten, ex_ee_len);
2638 path[depth].p_ext = ex;
2639
2640 a = ex_ee_block > start ? ex_ee_block : start;
2641 b = ex_ee_block+ex_ee_len - 1 < end ?
2642 ex_ee_block+ex_ee_len - 1 : end;
2643
2644 ext_debug(" border %u:%u\n", a, b);
2645
2646 /* If this extent is beyond the end of the hole, skip it */
2647 if (end < ex_ee_block) {
2648 /*
2649 * We're going to skip this extent and move to another,
2650 * so note that its first cluster is in use to avoid
2651 * freeing it when removing blocks. Eventually, the
2652 * right edge of the truncated/punched region will
2653 * be just to the left.
2654 */
2655 if (sbi->s_cluster_ratio > 1) {
2656 pblk = ext4_ext_pblock(ex);
2657 *partial_cluster =
2658 -(long long) EXT4_B2C(sbi, pblk);
2659 }
2660 ex--;
2661 ex_ee_block = le32_to_cpu(ex->ee_block);
2662 ex_ee_len = ext4_ext_get_actual_len(ex);
2663 continue;
2664 } else if (b != ex_ee_block + ex_ee_len - 1) {
2665 EXT4_ERROR_INODE(inode,
2666 "can not handle truncate %u:%u "
2667 "on extent %u:%u",
2668 start, end, ex_ee_block,
2669 ex_ee_block + ex_ee_len - 1);
2670 err = -EFSCORRUPTED;
2671 goto out;
2672 } else if (a != ex_ee_block) {
2673 /* remove tail of the extent */
2674 num = a - ex_ee_block;
2675 } else {
2676 /* remove whole extent: excellent! */
2677 num = 0;
2678 }
2679 /*
2680 * 3 for leaf, sb, and inode plus 2 (bmap and group
2681 * descriptor) for each block group; assume two block
2682 * groups plus ex_ee_len/blocks_per_block_group for
2683 * the worst case
2684 */
2685 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2686 if (ex == EXT_FIRST_EXTENT(eh)) {
2687 correct_index = 1;
2688 credits += (ext_depth(inode)) + 1;
2689 }
2690 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2691
2692 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2693 if (err)
2694 goto out;
2695
2696 err = ext4_ext_get_access(handle, inode, path + depth);
2697 if (err)
2698 goto out;
2699
2700 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2701 a, b);
2702 if (err)
2703 goto out;
2704
2705 if (num == 0)
2706 /* this extent is removed; mark slot entirely unused */
2707 ext4_ext_store_pblock(ex, 0);
2708
2709 ex->ee_len = cpu_to_le16(num);
2710 /*
2711 * Do not mark unwritten if all the blocks in the
2712 * extent have been removed.
2713 */
2714 if (unwritten && num)
2715 ext4_ext_mark_unwritten(ex);
2716 /*
2717 * If the extent was completely released,
2718 * we need to remove it from the leaf
2719 */
2720 if (num == 0) {
2721 if (end != EXT_MAX_BLOCKS - 1) {
2722 /*
2723 * For hole punching, we need to scoot all the
2724 * extents up when an extent is removed so that
2725 * we dont have blank extents in the middle
2726 */
2727 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2728 sizeof(struct ext4_extent));
2729
2730 /* Now get rid of the one at the end */
2731 memset(EXT_LAST_EXTENT(eh), 0,
2732 sizeof(struct ext4_extent));
2733 }
2734 le16_add_cpu(&eh->eh_entries, -1);
2735 }
2736
2737 err = ext4_ext_dirty(handle, inode, path + depth);
2738 if (err)
2739 goto out;
2740
2741 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2742 ext4_ext_pblock(ex));
2743 ex--;
2744 ex_ee_block = le32_to_cpu(ex->ee_block);
2745 ex_ee_len = ext4_ext_get_actual_len(ex);
2746 }
2747
2748 if (correct_index && eh->eh_entries)
2749 err = ext4_ext_correct_indexes(handle, inode, path);
2750
2751 /*
2752 * If there's a partial cluster and at least one extent remains in
2753 * the leaf, free the partial cluster if it isn't shared with the
2754 * current extent. If it is shared with the current extent
2755 * we zero partial_cluster because we've reached the start of the
2756 * truncated/punched region and we're done removing blocks.
2757 */
2758 if (*partial_cluster > 0 && ex >= EXT_FIRST_EXTENT(eh)) {
2759 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
2760 if (*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2761 ext4_free_blocks(handle, inode, NULL,
2762 EXT4_C2B(sbi, *partial_cluster),
2763 sbi->s_cluster_ratio,
2764 get_default_free_blocks_flags(inode));
2765 }
2766 *partial_cluster = 0;
2767 }
2768
2769 /* if this leaf is free, then we should
2770 * remove it from index block above */
2771 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2772 err = ext4_ext_rm_idx(handle, inode, path, depth);
2773
2774 out:
2775 return err;
2776 }
2777
2778 /*
2779 * ext4_ext_more_to_rm:
2780 * returns 1 if current index has to be freed (even partial)
2781 */
2782 static int
2783 ext4_ext_more_to_rm(struct ext4_ext_path *path)
2784 {
2785 BUG_ON(path->p_idx == NULL);
2786
2787 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2788 return 0;
2789
2790 /*
2791 * if truncate on deeper level happened, it wasn't partial,
2792 * so we have to consider current index for truncation
2793 */
2794 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2795 return 0;
2796 return 1;
2797 }
2798
2799 int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2800 ext4_lblk_t end)
2801 {
2802 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2803 int depth = ext_depth(inode);
2804 struct ext4_ext_path *path = NULL;
2805 long long partial_cluster = 0;
2806 handle_t *handle;
2807 int i = 0, err = 0;
2808
2809 ext_debug("truncate since %u to %u\n", start, end);
2810
2811 /* probably first extent we're gonna free will be last in block */
2812 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1);
2813 if (IS_ERR(handle))
2814 return PTR_ERR(handle);
2815
2816 again:
2817 trace_ext4_ext_remove_space(inode, start, end, depth);
2818
2819 /*
2820 * Check if we are removing extents inside the extent tree. If that
2821 * is the case, we are going to punch a hole inside the extent tree
2822 * so we have to check whether we need to split the extent covering
2823 * the last block to remove so we can easily remove the part of it
2824 * in ext4_ext_rm_leaf().
2825 */
2826 if (end < EXT_MAX_BLOCKS - 1) {
2827 struct ext4_extent *ex;
2828 ext4_lblk_t ee_block, ex_end, lblk;
2829 ext4_fsblk_t pblk;
2830
2831 /* find extent for or closest extent to this block */
2832 path = ext4_find_extent(inode, end, NULL, EXT4_EX_NOCACHE);
2833 if (IS_ERR(path)) {
2834 ext4_journal_stop(handle);
2835 return PTR_ERR(path);
2836 }
2837 depth = ext_depth(inode);
2838 /* Leaf not may not exist only if inode has no blocks at all */
2839 ex = path[depth].p_ext;
2840 if (!ex) {
2841 if (depth) {
2842 EXT4_ERROR_INODE(inode,
2843 "path[%d].p_hdr == NULL",
2844 depth);
2845 err = -EFSCORRUPTED;
2846 }
2847 goto out;
2848 }
2849
2850 ee_block = le32_to_cpu(ex->ee_block);
2851 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
2852
2853 /*
2854 * See if the last block is inside the extent, if so split
2855 * the extent at 'end' block so we can easily remove the
2856 * tail of the first part of the split extent in
2857 * ext4_ext_rm_leaf().
2858 */
2859 if (end >= ee_block && end < ex_end) {
2860
2861 /*
2862 * If we're going to split the extent, note that
2863 * the cluster containing the block after 'end' is
2864 * in use to avoid freeing it when removing blocks.
2865 */
2866 if (sbi->s_cluster_ratio > 1) {
2867 pblk = ext4_ext_pblock(ex) + end - ee_block + 2;
2868 partial_cluster =
2869 -(long long) EXT4_B2C(sbi, pblk);
2870 }
2871
2872 /*
2873 * Split the extent in two so that 'end' is the last
2874 * block in the first new extent. Also we should not
2875 * fail removing space due to ENOSPC so try to use
2876 * reserved block if that happens.
2877 */
2878 err = ext4_force_split_extent_at(handle, inode, &path,
2879 end + 1, 1);
2880 if (err < 0)
2881 goto out;
2882
2883 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end) {
2884 /*
2885 * If there's an extent to the right its first cluster
2886 * contains the immediate right boundary of the
2887 * truncated/punched region. Set partial_cluster to
2888 * its negative value so it won't be freed if shared
2889 * with the current extent. The end < ee_block case
2890 * is handled in ext4_ext_rm_leaf().
2891 */
2892 lblk = ex_end + 1;
2893 err = ext4_ext_search_right(inode, path, &lblk, &pblk,
2894 &ex);
2895 if (err)
2896 goto out;
2897 if (pblk)
2898 partial_cluster =
2899 -(long long) EXT4_B2C(sbi, pblk);
2900 }
2901 }
2902 /*
2903 * We start scanning from right side, freeing all the blocks
2904 * after i_size and walking into the tree depth-wise.
2905 */
2906 depth = ext_depth(inode);
2907 if (path) {
2908 int k = i = depth;
2909 while (--k > 0)
2910 path[k].p_block =
2911 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2912 } else {
2913 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2914 GFP_NOFS);
2915 if (path == NULL) {
2916 ext4_journal_stop(handle);
2917 return -ENOMEM;
2918 }
2919 path[0].p_maxdepth = path[0].p_depth = depth;
2920 path[0].p_hdr = ext_inode_hdr(inode);
2921 i = 0;
2922
2923 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2924 err = -EFSCORRUPTED;
2925 goto out;
2926 }
2927 }
2928 err = 0;
2929
2930 while (i >= 0 && err == 0) {
2931 if (i == depth) {
2932 /* this is leaf block */
2933 err = ext4_ext_rm_leaf(handle, inode, path,
2934 &partial_cluster, start,
2935 end);
2936 /* root level has p_bh == NULL, brelse() eats this */
2937 brelse(path[i].p_bh);
2938 path[i].p_bh = NULL;
2939 i--;
2940 continue;
2941 }
2942
2943 /* this is index block */
2944 if (!path[i].p_hdr) {
2945 ext_debug("initialize header\n");
2946 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2947 }
2948
2949 if (!path[i].p_idx) {
2950 /* this level hasn't been touched yet */
2951 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2952 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2953 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2954 path[i].p_hdr,
2955 le16_to_cpu(path[i].p_hdr->eh_entries));
2956 } else {
2957 /* we were already here, see at next index */
2958 path[i].p_idx--;
2959 }
2960
2961 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2962 i, EXT_FIRST_INDEX(path[i].p_hdr),
2963 path[i].p_idx);
2964 if (ext4_ext_more_to_rm(path + i)) {
2965 struct buffer_head *bh;
2966 /* go to the next level */
2967 ext_debug("move to level %d (block %llu)\n",
2968 i + 1, ext4_idx_pblock(path[i].p_idx));
2969 memset(path + i + 1, 0, sizeof(*path));
2970 bh = read_extent_tree_block(inode,
2971 ext4_idx_pblock(path[i].p_idx), depth - i - 1,
2972 EXT4_EX_NOCACHE);
2973 if (IS_ERR(bh)) {
2974 /* should we reset i_size? */
2975 err = PTR_ERR(bh);
2976 break;
2977 }
2978 /* Yield here to deal with large extent trees.
2979 * Should be a no-op if we did IO above. */
2980 cond_resched();
2981 if (WARN_ON(i + 1 > depth)) {
2982 err = -EFSCORRUPTED;
2983 break;
2984 }
2985 path[i + 1].p_bh = bh;
2986
2987 /* save actual number of indexes since this
2988 * number is changed at the next iteration */
2989 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2990 i++;
2991 } else {
2992 /* we finished processing this index, go up */
2993 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2994 /* index is empty, remove it;
2995 * handle must be already prepared by the
2996 * truncatei_leaf() */
2997 err = ext4_ext_rm_idx(handle, inode, path, i);
2998 }
2999 /* root level has p_bh == NULL, brelse() eats this */
3000 brelse(path[i].p_bh);
3001 path[i].p_bh = NULL;
3002 i--;
3003 ext_debug("return to level %d\n", i);
3004 }
3005 }
3006
3007 trace_ext4_ext_remove_space_done(inode, start, end, depth,
3008 partial_cluster, path->p_hdr->eh_entries);
3009
3010 /*
3011 * If we still have something in the partial cluster and we have removed
3012 * even the first extent, then we should free the blocks in the partial
3013 * cluster as well. (This code will only run when there are no leaves
3014 * to the immediate left of the truncated/punched region.)
3015 */
3016 if (partial_cluster > 0 && err == 0) {
3017 /* don't zero partial_cluster since it's not used afterwards */
3018 ext4_free_blocks(handle, inode, NULL,
3019 EXT4_C2B(sbi, partial_cluster),
3020 sbi->s_cluster_ratio,
3021 get_default_free_blocks_flags(inode));
3022 }
3023
3024 /* TODO: flexible tree reduction should be here */
3025 if (path->p_hdr->eh_entries == 0) {
3026 /*
3027 * truncate to zero freed all the tree,
3028 * so we need to correct eh_depth
3029 */
3030 err = ext4_ext_get_access(handle, inode, path);
3031 if (err == 0) {
3032 ext_inode_hdr(inode)->eh_depth = 0;
3033 ext_inode_hdr(inode)->eh_max =
3034 cpu_to_le16(ext4_ext_space_root(inode, 0));
3035 err = ext4_ext_dirty(handle, inode, path);
3036 }
3037 }
3038 out:
3039 ext4_ext_drop_refs(path);
3040 kfree(path);
3041 path = NULL;
3042 if (err == -EAGAIN)
3043 goto again;
3044 ext4_journal_stop(handle);
3045
3046 return err;
3047 }
3048
3049 /*
3050 * called at mount time
3051 */
3052 void ext4_ext_init(struct super_block *sb)
3053 {
3054 /*
3055 * possible initialization would be here
3056 */
3057
3058 if (ext4_has_feature_extents(sb)) {
3059 #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
3060 printk(KERN_INFO "EXT4-fs: file extents enabled"
3061 #ifdef AGGRESSIVE_TEST
3062 ", aggressive tests"
3063 #endif
3064 #ifdef CHECK_BINSEARCH
3065 ", check binsearch"
3066 #endif
3067 #ifdef EXTENTS_STATS
3068 ", stats"
3069 #endif
3070 "\n");
3071 #endif
3072 #ifdef EXTENTS_STATS
3073 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3074 EXT4_SB(sb)->s_ext_min = 1 << 30;
3075 EXT4_SB(sb)->s_ext_max = 0;
3076 #endif
3077 }
3078 }
3079
3080 /*
3081 * called at umount time
3082 */
3083 void ext4_ext_release(struct super_block *sb)
3084 {
3085 if (!ext4_has_feature_extents(sb))
3086 return;
3087
3088 #ifdef EXTENTS_STATS
3089 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3090 struct ext4_sb_info *sbi = EXT4_SB(sb);
3091 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3092 sbi->s_ext_blocks, sbi->s_ext_extents,
3093 sbi->s_ext_blocks / sbi->s_ext_extents);
3094 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3095 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3096 }
3097 #endif
3098 }
3099
3100 static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3101 {
3102 ext4_lblk_t ee_block;
3103 ext4_fsblk_t ee_pblock;
3104 unsigned int ee_len;
3105
3106 ee_block = le32_to_cpu(ex->ee_block);
3107 ee_len = ext4_ext_get_actual_len(ex);
3108 ee_pblock = ext4_ext_pblock(ex);
3109
3110 if (ee_len == 0)
3111 return 0;
3112
3113 return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3114 EXTENT_STATUS_WRITTEN);
3115 }
3116
3117 /* FIXME!! we need to try to merge to left or right after zero-out */
3118 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3119 {
3120 ext4_fsblk_t ee_pblock;
3121 unsigned int ee_len;
3122 int ret;
3123
3124 ee_len = ext4_ext_get_actual_len(ex);
3125 ee_pblock = ext4_ext_pblock(ex);
3126
3127 if (ext4_encrypted_inode(inode))
3128 return ext4_encrypted_zeroout(inode, ex);
3129
3130 ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
3131 if (ret > 0)
3132 ret = 0;
3133
3134 return ret;
3135 }
3136
3137 /*
3138 * ext4_split_extent_at() splits an extent at given block.
3139 *
3140 * @handle: the journal handle
3141 * @inode: the file inode
3142 * @path: the path to the extent
3143 * @split: the logical block where the extent is splitted.
3144 * @split_flags: indicates if the extent could be zeroout if split fails, and
3145 * the states(init or unwritten) of new extents.
3146 * @flags: flags used to insert new extent to extent tree.
3147 *
3148 *
3149 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3150 * of which are deterimined by split_flag.
3151 *
3152 * There are two cases:
3153 * a> the extent are splitted into two extent.
3154 * b> split is not needed, and just mark the extent.
3155 *
3156 * return 0 on success.
3157 */
3158 static int ext4_split_extent_at(handle_t *handle,
3159 struct inode *inode,
3160 struct ext4_ext_path **ppath,
3161 ext4_lblk_t split,
3162 int split_flag,
3163 int flags)
3164 {
3165 struct ext4_ext_path *path = *ppath;
3166 ext4_fsblk_t newblock;
3167 ext4_lblk_t ee_block;
3168 struct ext4_extent *ex, newex, orig_ex, zero_ex;
3169 struct ext4_extent *ex2 = NULL;
3170 unsigned int ee_len, depth;
3171 int err = 0;
3172
3173 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3174 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3175
3176 ext_debug("ext4_split_extents_at: inode %lu, logical"
3177 "block %llu\n", inode->i_ino, (unsigned long long)split);
3178
3179 ext4_ext_show_leaf(inode, path);
3180
3181 depth = ext_depth(inode);
3182 ex = path[depth].p_ext;
3183 ee_block = le32_to_cpu(ex->ee_block);
3184 ee_len = ext4_ext_get_actual_len(ex);
3185 newblock = split - ee_block + ext4_ext_pblock(ex);
3186
3187 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3188 BUG_ON(!ext4_ext_is_unwritten(ex) &&
3189 split_flag & (EXT4_EXT_MAY_ZEROOUT |
3190 EXT4_EXT_MARK_UNWRIT1 |
3191 EXT4_EXT_MARK_UNWRIT2));
3192
3193 err = ext4_ext_get_access(handle, inode, path + depth);
3194 if (err)
3195 goto out;
3196
3197 if (split == ee_block) {
3198 /*
3199 * case b: block @split is the block that the extent begins with
3200 * then we just change the state of the extent, and splitting
3201 * is not needed.
3202 */
3203 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3204 ext4_ext_mark_unwritten(ex);
3205 else
3206 ext4_ext_mark_initialized(ex);
3207
3208 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3209 ext4_ext_try_to_merge(handle, inode, path, ex);
3210
3211 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3212 goto out;
3213 }
3214
3215 /* case a */
3216 memcpy(&orig_ex, ex, sizeof(orig_ex));
3217 ex->ee_len = cpu_to_le16(split - ee_block);
3218 if (split_flag & EXT4_EXT_MARK_UNWRIT1)
3219 ext4_ext_mark_unwritten(ex);
3220
3221 /*
3222 * path may lead to new leaf, not to original leaf any more
3223 * after ext4_ext_insert_extent() returns,
3224 */
3225 err = ext4_ext_dirty(handle, inode, path + depth);
3226 if (err)
3227 goto fix_extent_len;
3228
3229 ex2 = &newex;
3230 ex2->ee_block = cpu_to_le32(split);
3231 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
3232 ext4_ext_store_pblock(ex2, newblock);
3233 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3234 ext4_ext_mark_unwritten(ex2);
3235
3236 err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
3237 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3238 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3239 if (split_flag & EXT4_EXT_DATA_VALID1) {
3240 err = ext4_ext_zeroout(inode, ex2);
3241 zero_ex.ee_block = ex2->ee_block;
3242 zero_ex.ee_len = cpu_to_le16(
3243 ext4_ext_get_actual_len(ex2));
3244 ext4_ext_store_pblock(&zero_ex,
3245 ext4_ext_pblock(ex2));
3246 } else {
3247 err = ext4_ext_zeroout(inode, ex);
3248 zero_ex.ee_block = ex->ee_block;
3249 zero_ex.ee_len = cpu_to_le16(
3250 ext4_ext_get_actual_len(ex));
3251 ext4_ext_store_pblock(&zero_ex,
3252 ext4_ext_pblock(ex));
3253 }
3254 } else {
3255 err = ext4_ext_zeroout(inode, &orig_ex);
3256 zero_ex.ee_block = orig_ex.ee_block;
3257 zero_ex.ee_len = cpu_to_le16(
3258 ext4_ext_get_actual_len(&orig_ex));
3259 ext4_ext_store_pblock(&zero_ex,
3260 ext4_ext_pblock(&orig_ex));
3261 }
3262
3263 if (err)
3264 goto fix_extent_len;
3265 /* update the extent length and mark as initialized */
3266 ex->ee_len = cpu_to_le16(ee_len);
3267 ext4_ext_try_to_merge(handle, inode, path, ex);
3268 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3269 if (err)
3270 goto fix_extent_len;
3271
3272 /* update extent status tree */
3273 err = ext4_zeroout_es(inode, &zero_ex);
3274
3275 goto out;
3276 } else if (err)
3277 goto fix_extent_len;
3278
3279 out:
3280 ext4_ext_show_leaf(inode, path);
3281 return err;
3282
3283 fix_extent_len:
3284 ex->ee_len = orig_ex.ee_len;
3285 ext4_ext_dirty(handle, inode, path + path->p_depth);
3286 return err;
3287 }
3288
3289 /*
3290 * ext4_split_extents() splits an extent and mark extent which is covered
3291 * by @map as split_flags indicates
3292 *
3293 * It may result in splitting the extent into multiple extents (up to three)
3294 * There are three possibilities:
3295 * a> There is no split required
3296 * b> Splits in two extents: Split is happening at either end of the extent
3297 * c> Splits in three extents: Somone is splitting in middle of the extent
3298 *
3299 */
3300 static int ext4_split_extent(handle_t *handle,
3301 struct inode *inode,
3302 struct ext4_ext_path **ppath,
3303 struct ext4_map_blocks *map,
3304 int split_flag,
3305 int flags)
3306 {
3307 struct ext4_ext_path *path = *ppath;
3308 ext4_lblk_t ee_block;
3309 struct ext4_extent *ex;
3310 unsigned int ee_len, depth;
3311 int err = 0;
3312 int unwritten;
3313 int split_flag1, flags1;
3314 int allocated = map->m_len;
3315
3316 depth = ext_depth(inode);
3317 ex = path[depth].p_ext;
3318 ee_block = le32_to_cpu(ex->ee_block);
3319 ee_len = ext4_ext_get_actual_len(ex);
3320 unwritten = ext4_ext_is_unwritten(ex);
3321
3322 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3323 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3324 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3325 if (unwritten)
3326 split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
3327 EXT4_EXT_MARK_UNWRIT2;
3328 if (split_flag & EXT4_EXT_DATA_VALID2)
3329 split_flag1 |= EXT4_EXT_DATA_VALID1;
3330 err = ext4_split_extent_at(handle, inode, ppath,
3331 map->m_lblk + map->m_len, split_flag1, flags1);
3332 if (err)
3333 goto out;
3334 } else {
3335 allocated = ee_len - (map->m_lblk - ee_block);
3336 }
3337 /*
3338 * Update path is required because previous ext4_split_extent_at() may
3339 * result in split of original leaf or extent zeroout.
3340 */
3341 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3342 if (IS_ERR(path))
3343 return PTR_ERR(path);
3344 depth = ext_depth(inode);
3345 ex = path[depth].p_ext;
3346 if (!ex) {
3347 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3348 (unsigned long) map->m_lblk);
3349 return -EFSCORRUPTED;
3350 }
3351 unwritten = ext4_ext_is_unwritten(ex);
3352 split_flag1 = 0;
3353
3354 if (map->m_lblk >= ee_block) {
3355 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3356 if (unwritten) {
3357 split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
3358 split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3359 EXT4_EXT_MARK_UNWRIT2);
3360 }
3361 err = ext4_split_extent_at(handle, inode, ppath,
3362 map->m_lblk, split_flag1, flags);
3363 if (err)
3364 goto out;
3365 }
3366
3367 ext4_ext_show_leaf(inode, path);
3368 out:
3369 return err ? err : allocated;
3370 }
3371
3372 /*
3373 * This function is called by ext4_ext_map_blocks() if someone tries to write
3374 * to an unwritten extent. It may result in splitting the unwritten
3375 * extent into multiple extents (up to three - one initialized and two
3376 * unwritten).
3377 * There are three possibilities:
3378 * a> There is no split required: Entire extent should be initialized
3379 * b> Splits in two extents: Write is happening at either end of the extent
3380 * c> Splits in three extents: Somone is writing in middle of the extent
3381 *
3382 * Pre-conditions:
3383 * - The extent pointed to by 'path' is unwritten.
3384 * - The extent pointed to by 'path' contains a superset
3385 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3386 *
3387 * Post-conditions on success:
3388 * - the returned value is the number of blocks beyond map->l_lblk
3389 * that are allocated and initialized.
3390 * It is guaranteed to be >= map->m_len.
3391 */
3392 static int ext4_ext_convert_to_initialized(handle_t *handle,
3393 struct inode *inode,
3394 struct ext4_map_blocks *map,
3395 struct ext4_ext_path **ppath,
3396 int flags)
3397 {
3398 struct ext4_ext_path *path = *ppath;
3399 struct ext4_sb_info *sbi;
3400 struct ext4_extent_header *eh;
3401 struct ext4_map_blocks split_map;
3402 struct ext4_extent zero_ex;
3403 struct ext4_extent *ex, *abut_ex;
3404 ext4_lblk_t ee_block, eof_block;
3405 unsigned int ee_len, depth, map_len = map->m_len;
3406 int allocated = 0, max_zeroout = 0;
3407 int err = 0;
3408 int split_flag = 0;
3409
3410 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3411 "block %llu, max_blocks %u\n", inode->i_ino,
3412 (unsigned long long)map->m_lblk, map_len);
3413
3414 sbi = EXT4_SB(inode->i_sb);
3415 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3416 inode->i_sb->s_blocksize_bits;
3417 if (eof_block < map->m_lblk + map_len)
3418 eof_block = map->m_lblk + map_len;
3419
3420 depth = ext_depth(inode);
3421 eh = path[depth].p_hdr;
3422 ex = path[depth].p_ext;
3423 ee_block = le32_to_cpu(ex->ee_block);
3424 ee_len = ext4_ext_get_actual_len(ex);
3425 zero_ex.ee_len = 0;
3426
3427 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3428
3429 /* Pre-conditions */
3430 BUG_ON(!ext4_ext_is_unwritten(ex));
3431 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3432
3433 /*
3434 * Attempt to transfer newly initialized blocks from the currently
3435 * unwritten extent to its neighbor. This is much cheaper
3436 * than an insertion followed by a merge as those involve costly
3437 * memmove() calls. Transferring to the left is the common case in
3438 * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3439 * followed by append writes.
3440 *
3441 * Limitations of the current logic:
3442 * - L1: we do not deal with writes covering the whole extent.
3443 * This would require removing the extent if the transfer
3444 * is possible.
3445 * - L2: we only attempt to merge with an extent stored in the
3446 * same extent tree node.
3447 */
3448 if ((map->m_lblk == ee_block) &&
3449 /* See if we can merge left */
3450 (map_len < ee_len) && /*L1*/
3451 (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/
3452 ext4_lblk_t prev_lblk;
3453 ext4_fsblk_t prev_pblk, ee_pblk;
3454 unsigned int prev_len;
3455
3456 abut_ex = ex - 1;
3457 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3458 prev_len = ext4_ext_get_actual_len(abut_ex);
3459 prev_pblk = ext4_ext_pblock(abut_ex);
3460 ee_pblk = ext4_ext_pblock(ex);
3461
3462 /*
3463 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3464 * upon those conditions:
3465 * - C1: abut_ex is initialized,
3466 * - C2: abut_ex is logically abutting ex,
3467 * - C3: abut_ex is physically abutting ex,
3468 * - C4: abut_ex can receive the additional blocks without
3469 * overflowing the (initialized) length limit.
3470 */
3471 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3472 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3473 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3474 (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3475 err = ext4_ext_get_access(handle, inode, path + depth);
3476 if (err)
3477 goto out;
3478
3479 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3480 map, ex, abut_ex);
3481
3482 /* Shift the start of ex by 'map_len' blocks */
3483 ex->ee_block = cpu_to_le32(ee_block + map_len);
3484 ext4_ext_store_pblock(ex, ee_pblk + map_len);
3485 ex->ee_len = cpu_to_le16(ee_len - map_len);
3486 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3487
3488 /* Extend abut_ex by 'map_len' blocks */
3489 abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3490
3491 /* Result: number of initialized blocks past m_lblk */
3492 allocated = map_len;
3493 }
3494 } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3495 (map_len < ee_len) && /*L1*/
3496 ex < EXT_LAST_EXTENT(eh)) { /*L2*/
3497 /* See if we can merge right */
3498 ext4_lblk_t next_lblk;
3499 ext4_fsblk_t next_pblk, ee_pblk;
3500 unsigned int next_len;
3501
3502 abut_ex = ex + 1;
3503 next_lblk = le32_to_cpu(abut_ex->ee_block);
3504 next_len = ext4_ext_get_actual_len(abut_ex);
3505 next_pblk = ext4_ext_pblock(abut_ex);
3506 ee_pblk = ext4_ext_pblock(ex);
3507
3508 /*
3509 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3510 * upon those conditions:
3511 * - C1: abut_ex is initialized,
3512 * - C2: abut_ex is logically abutting ex,
3513 * - C3: abut_ex is physically abutting ex,
3514 * - C4: abut_ex can receive the additional blocks without
3515 * overflowing the (initialized) length limit.
3516 */
3517 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3518 ((map->m_lblk + map_len) == next_lblk) && /*C2*/
3519 ((ee_pblk + ee_len) == next_pblk) && /*C3*/
3520 (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3521 err = ext4_ext_get_access(handle, inode, path + depth);
3522 if (err)
3523 goto out;
3524
3525 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3526 map, ex, abut_ex);
3527
3528 /* Shift the start of abut_ex by 'map_len' blocks */
3529 abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3530 ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3531 ex->ee_len = cpu_to_le16(ee_len - map_len);
3532 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3533
3534 /* Extend abut_ex by 'map_len' blocks */
3535 abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3536
3537 /* Result: number of initialized blocks past m_lblk */
3538 allocated = map_len;
3539 }
3540 }
3541 if (allocated) {
3542 /* Mark the block containing both extents as dirty */
3543 ext4_ext_dirty(handle, inode, path + depth);
3544
3545 /* Update path to point to the right extent */
3546 path[depth].p_ext = abut_ex;
3547 goto out;
3548 } else
3549 allocated = ee_len - (map->m_lblk - ee_block);
3550
3551 WARN_ON(map->m_lblk < ee_block);
3552 /*
3553 * It is safe to convert extent to initialized via explicit
3554 * zeroout only if extent is fully inside i_size or new_size.
3555 */
3556 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3557
3558 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3559 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3560 (inode->i_sb->s_blocksize_bits - 10);
3561
3562 if (ext4_encrypted_inode(inode))
3563 max_zeroout = 0;
3564
3565 /* If extent is less than s_max_zeroout_kb, zeroout directly */
3566 if (max_zeroout && (ee_len <= max_zeroout)) {
3567 err = ext4_ext_zeroout(inode, ex);
3568 if (err)
3569 goto out;
3570 zero_ex.ee_block = ex->ee_block;
3571 zero_ex.ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex));
3572 ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex));
3573
3574 err = ext4_ext_get_access(handle, inode, path + depth);
3575 if (err)
3576 goto out;
3577 ext4_ext_mark_initialized(ex);
3578 ext4_ext_try_to_merge(handle, inode, path, ex);
3579 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3580 goto out;
3581 }
3582
3583 /*
3584 * four cases:
3585 * 1. split the extent into three extents.
3586 * 2. split the extent into two extents, zeroout the first half.
3587 * 3. split the extent into two extents, zeroout the second half.
3588 * 4. split the extent into two extents with out zeroout.
3589 */
3590 split_map.m_lblk = map->m_lblk;
3591 split_map.m_len = map->m_len;
3592
3593 if (max_zeroout && (allocated > map->m_len)) {
3594 if (allocated <= max_zeroout) {
3595 /* case 3 */
3596 zero_ex.ee_block =
3597 cpu_to_le32(map->m_lblk);
3598 zero_ex.ee_len = cpu_to_le16(allocated);
3599 ext4_ext_store_pblock(&zero_ex,
3600 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
3601 err = ext4_ext_zeroout(inode, &zero_ex);
3602 if (err)
3603 goto out;
3604 split_map.m_lblk = map->m_lblk;
3605 split_map.m_len = allocated;
3606 } else if (map->m_lblk - ee_block + map->m_len < max_zeroout) {
3607 /* case 2 */
3608 if (map->m_lblk != ee_block) {
3609 zero_ex.ee_block = ex->ee_block;
3610 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
3611 ee_block);
3612 ext4_ext_store_pblock(&zero_ex,
3613 ext4_ext_pblock(ex));
3614 err = ext4_ext_zeroout(inode, &zero_ex);
3615 if (err)
3616 goto out;
3617 }
3618
3619 split_map.m_lblk = ee_block;
3620 split_map.m_len = map->m_lblk - ee_block + map->m_len;
3621 allocated = map->m_len;
3622 }
3623 }
3624
3625 err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
3626 flags);
3627 if (err > 0)
3628 err = 0;
3629 out:
3630 /* If we have gotten a failure, don't zero out status tree */
3631 if (!err)
3632 err = ext4_zeroout_es(inode, &zero_ex);
3633 return err ? err : allocated;
3634 }
3635
3636 /*
3637 * This function is called by ext4_ext_map_blocks() from
3638 * ext4_get_blocks_dio_write() when DIO to write
3639 * to an unwritten extent.
3640 *
3641 * Writing to an unwritten extent may result in splitting the unwritten
3642 * extent into multiple initialized/unwritten extents (up to three)
3643 * There are three possibilities:
3644 * a> There is no split required: Entire extent should be unwritten
3645 * b> Splits in two extents: Write is happening at either end of the extent
3646 * c> Splits in three extents: Somone is writing in middle of the extent
3647 *
3648 * This works the same way in the case of initialized -> unwritten conversion.
3649 *
3650 * One of more index blocks maybe needed if the extent tree grow after
3651 * the unwritten extent split. To prevent ENOSPC occur at the IO
3652 * complete, we need to split the unwritten extent before DIO submit
3653 * the IO. The unwritten extent called at this time will be split
3654 * into three unwritten extent(at most). After IO complete, the part
3655 * being filled will be convert to initialized by the end_io callback function
3656 * via ext4_convert_unwritten_extents().
3657 *
3658 * Returns the size of unwritten extent to be written on success.
3659 */
3660 static int ext4_split_convert_extents(handle_t *handle,
3661 struct inode *inode,
3662 struct ext4_map_blocks *map,
3663 struct ext4_ext_path **ppath,
3664 int flags)
3665 {
3666 struct ext4_ext_path *path = *ppath;
3667 ext4_lblk_t eof_block;
3668 ext4_lblk_t ee_block;
3669 struct ext4_extent *ex;
3670 unsigned int ee_len;
3671 int split_flag = 0, depth;
3672
3673 ext_debug("%s: inode %lu, logical block %llu, max_blocks %u\n",
3674 __func__, inode->i_ino,
3675 (unsigned long long)map->m_lblk, map->m_len);
3676
3677 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3678 inode->i_sb->s_blocksize_bits;
3679 if (eof_block < map->m_lblk + map->m_len)
3680 eof_block = map->m_lblk + map->m_len;
3681 /*
3682 * It is safe to convert extent to initialized via explicit
3683 * zeroout only if extent is fully insde i_size or new_size.
3684 */
3685 depth = ext_depth(inode);
3686 ex = path[depth].p_ext;
3687 ee_block = le32_to_cpu(ex->ee_block);
3688 ee_len = ext4_ext_get_actual_len(ex);
3689
3690 /* Convert to unwritten */
3691 if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
3692 split_flag |= EXT4_EXT_DATA_VALID1;
3693 /* Convert to initialized */
3694 } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
3695 split_flag |= ee_block + ee_len <= eof_block ?
3696 EXT4_EXT_MAY_ZEROOUT : 0;
3697 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
3698 }
3699 flags |= EXT4_GET_BLOCKS_PRE_IO;
3700 return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
3701 }
3702
3703 static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3704 struct inode *inode,
3705 struct ext4_map_blocks *map,
3706 struct ext4_ext_path **ppath)
3707 {
3708 struct ext4_ext_path *path = *ppath;
3709 struct ext4_extent *ex;
3710 ext4_lblk_t ee_block;
3711 unsigned int ee_len;
3712 int depth;
3713 int err = 0;
3714
3715 depth = ext_depth(inode);
3716 ex = path[depth].p_ext;
3717 ee_block = le32_to_cpu(ex->ee_block);
3718 ee_len = ext4_ext_get_actual_len(ex);
3719
3720 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3721 "block %llu, max_blocks %u\n", inode->i_ino,
3722 (unsigned long long)ee_block, ee_len);
3723
3724 /* If extent is larger than requested it is a clear sign that we still
3725 * have some extent state machine issues left. So extent_split is still
3726 * required.
3727 * TODO: Once all related issues will be fixed this situation should be
3728 * illegal.
3729 */
3730 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3731 #ifdef EXT4_DEBUG
3732 ext4_warning("Inode (%ld) finished: extent logical block %llu,"
3733 " len %u; IO logical block %llu, len %u\n",
3734 inode->i_ino, (unsigned long long)ee_block, ee_len,
3735 (unsigned long long)map->m_lblk, map->m_len);
3736 #endif
3737 err = ext4_split_convert_extents(handle, inode, map, ppath,
3738 EXT4_GET_BLOCKS_CONVERT);
3739 if (err < 0)
3740 return err;
3741 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3742 if (IS_ERR(path))
3743 return PTR_ERR(path);
3744 depth = ext_depth(inode);
3745 ex = path[depth].p_ext;
3746 }
3747
3748 err = ext4_ext_get_access(handle, inode, path + depth);
3749 if (err)
3750 goto out;
3751 /* first mark the extent as initialized */
3752 ext4_ext_mark_initialized(ex);
3753
3754 /* note: ext4_ext_correct_indexes() isn't needed here because
3755 * borders are not changed
3756 */
3757 ext4_ext_try_to_merge(handle, inode, path, ex);
3758
3759 /* Mark modified extent as dirty */
3760 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3761 out:
3762 ext4_ext_show_leaf(inode, path);
3763 return err;
3764 }
3765
3766 static void unmap_underlying_metadata_blocks(struct block_device *bdev,
3767 sector_t block, int count)
3768 {
3769 int i;
3770 for (i = 0; i < count; i++)
3771 unmap_underlying_metadata(bdev, block + i);
3772 }
3773
3774 /*
3775 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3776 */
3777 static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3778 ext4_lblk_t lblk,
3779 struct ext4_ext_path *path,
3780 unsigned int len)
3781 {
3782 int i, depth;
3783 struct ext4_extent_header *eh;
3784 struct ext4_extent *last_ex;
3785
3786 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3787 return 0;
3788
3789 depth = ext_depth(inode);
3790 eh = path[depth].p_hdr;
3791
3792 /*
3793 * We're going to remove EOFBLOCKS_FL entirely in future so we
3794 * do not care for this case anymore. Simply remove the flag
3795 * if there are no extents.
3796 */
3797 if (unlikely(!eh->eh_entries))
3798 goto out;
3799 last_ex = EXT_LAST_EXTENT(eh);
3800 /*
3801 * We should clear the EOFBLOCKS_FL flag if we are writing the
3802 * last block in the last extent in the file. We test this by
3803 * first checking to see if the caller to
3804 * ext4_ext_get_blocks() was interested in the last block (or
3805 * a block beyond the last block) in the current extent. If
3806 * this turns out to be false, we can bail out from this
3807 * function immediately.
3808 */
3809 if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3810 ext4_ext_get_actual_len(last_ex))
3811 return 0;
3812 /*
3813 * If the caller does appear to be planning to write at or
3814 * beyond the end of the current extent, we then test to see
3815 * if the current extent is the last extent in the file, by
3816 * checking to make sure it was reached via the rightmost node
3817 * at each level of the tree.
3818 */
3819 for (i = depth-1; i >= 0; i--)
3820 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3821 return 0;
3822 out:
3823 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3824 return ext4_mark_inode_dirty(handle, inode);
3825 }
3826
3827 /**
3828 * ext4_find_delalloc_range: find delayed allocated block in the given range.
3829 *
3830 * Return 1 if there is a delalloc block in the range, otherwise 0.
3831 */
3832 int ext4_find_delalloc_range(struct inode *inode,
3833 ext4_lblk_t lblk_start,
3834 ext4_lblk_t lblk_end)
3835 {
3836 struct extent_status es;
3837
3838 ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es);
3839 if (es.es_len == 0)
3840 return 0; /* there is no delay extent in this tree */
3841 else if (es.es_lblk <= lblk_start &&
3842 lblk_start < es.es_lblk + es.es_len)
3843 return 1;
3844 else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end)
3845 return 1;
3846 else
3847 return 0;
3848 }
3849
3850 int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
3851 {
3852 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3853 ext4_lblk_t lblk_start, lblk_end;
3854 lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
3855 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3856
3857 return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
3858 }
3859
3860 /**
3861 * Determines how many complete clusters (out of those specified by the 'map')
3862 * are under delalloc and were reserved quota for.
3863 * This function is called when we are writing out the blocks that were
3864 * originally written with their allocation delayed, but then the space was
3865 * allocated using fallocate() before the delayed allocation could be resolved.
3866 * The cases to look for are:
3867 * ('=' indicated delayed allocated blocks
3868 * '-' indicates non-delayed allocated blocks)
3869 * (a) partial clusters towards beginning and/or end outside of allocated range
3870 * are not delalloc'ed.
3871 * Ex:
3872 * |----c---=|====c====|====c====|===-c----|
3873 * |++++++ allocated ++++++|
3874 * ==> 4 complete clusters in above example
3875 *
3876 * (b) partial cluster (outside of allocated range) towards either end is
3877 * marked for delayed allocation. In this case, we will exclude that
3878 * cluster.
3879 * Ex:
3880 * |----====c========|========c========|
3881 * |++++++ allocated ++++++|
3882 * ==> 1 complete clusters in above example
3883 *
3884 * Ex:
3885 * |================c================|
3886 * |++++++ allocated ++++++|
3887 * ==> 0 complete clusters in above example
3888 *
3889 * The ext4_da_update_reserve_space will be called only if we
3890 * determine here that there were some "entire" clusters that span
3891 * this 'allocated' range.
3892 * In the non-bigalloc case, this function will just end up returning num_blks
3893 * without ever calling ext4_find_delalloc_range.
3894 */
3895 static unsigned int
3896 get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3897 unsigned int num_blks)
3898 {
3899 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3900 ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3901 ext4_lblk_t lblk_from, lblk_to, c_offset;
3902 unsigned int allocated_clusters = 0;
3903
3904 alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3905 alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3906
3907 /* max possible clusters for this allocation */
3908 allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3909
3910 trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3911
3912 /* Check towards left side */
3913 c_offset = EXT4_LBLK_COFF(sbi, lblk_start);
3914 if (c_offset) {
3915 lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start);
3916 lblk_to = lblk_from + c_offset - 1;
3917
3918 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3919 allocated_clusters--;
3920 }
3921
3922 /* Now check towards right. */
3923 c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks);
3924 if (allocated_clusters && c_offset) {
3925 lblk_from = lblk_start + num_blks;
3926 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3927
3928 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3929 allocated_clusters--;
3930 }
3931
3932 return allocated_clusters;
3933 }
3934
3935 static int
3936 convert_initialized_extent(handle_t *handle, struct inode *inode,
3937 struct ext4_map_blocks *map,
3938 struct ext4_ext_path **ppath, int flags,
3939 unsigned int allocated, ext4_fsblk_t newblock)
3940 {
3941 struct ext4_ext_path *path = *ppath;
3942 struct ext4_extent *ex;
3943 ext4_lblk_t ee_block;
3944 unsigned int ee_len;
3945 int depth;
3946 int err = 0;
3947
3948 /*
3949 * Make sure that the extent is no bigger than we support with
3950 * unwritten extent
3951 */
3952 if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
3953 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
3954
3955 depth = ext_depth(inode);
3956 ex = path[depth].p_ext;
3957 ee_block = le32_to_cpu(ex->ee_block);
3958 ee_len = ext4_ext_get_actual_len(ex);
3959
3960 ext_debug("%s: inode %lu, logical"
3961 "block %llu, max_blocks %u\n", __func__, inode->i_ino,
3962 (unsigned long long)ee_block, ee_len);
3963
3964 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3965 err = ext4_split_convert_extents(handle, inode, map, ppath,
3966 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
3967 if (err < 0)
3968 return err;
3969 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3970 if (IS_ERR(path))
3971 return PTR_ERR(path);
3972 depth = ext_depth(inode);
3973 ex = path[depth].p_ext;
3974 if (!ex) {
3975 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3976 (unsigned long) map->m_lblk);
3977 return -EFSCORRUPTED;
3978 }
3979 }
3980
3981 err = ext4_ext_get_access(handle, inode, path + depth);
3982 if (err)
3983 return err;
3984 /* first mark the extent as unwritten */
3985 ext4_ext_mark_unwritten(ex);
3986
3987 /* note: ext4_ext_correct_indexes() isn't needed here because
3988 * borders are not changed
3989 */
3990 ext4_ext_try_to_merge(handle, inode, path, ex);
3991
3992 /* Mark modified extent as dirty */
3993 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3994 if (err)
3995 return err;
3996 ext4_ext_show_leaf(inode, path);
3997
3998 ext4_update_inode_fsync_trans(handle, inode, 1);
3999 err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len);
4000 if (err)
4001 return err;
4002 map->m_flags |= EXT4_MAP_UNWRITTEN;
4003 if (allocated > map->m_len)
4004 allocated = map->m_len;
4005 map->m_len = allocated;
4006 return allocated;
4007 }
4008
4009 static int
4010 ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
4011 struct ext4_map_blocks *map,
4012 struct ext4_ext_path **ppath, int flags,
4013 unsigned int allocated, ext4_fsblk_t newblock)
4014 {
4015 struct ext4_ext_path *path = *ppath;
4016 int ret = 0;
4017 int err = 0;
4018 ext4_io_end_t *io = ext4_inode_aio(inode);
4019
4020 ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical "
4021 "block %llu, max_blocks %u, flags %x, allocated %u\n",
4022 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
4023 flags, allocated);
4024 ext4_ext_show_leaf(inode, path);
4025
4026 /*
4027 * When writing into unwritten space, we should not fail to
4028 * allocate metadata blocks for the new extent block if needed.
4029 */
4030 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
4031
4032 trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
4033 allocated, newblock);
4034
4035 /* get_block() before submit the IO, split the extent */
4036 if (flags & EXT4_GET_BLOCKS_PRE_IO) {
4037 ret = ext4_split_convert_extents(handle, inode, map, ppath,
4038 flags | EXT4_GET_BLOCKS_CONVERT);
4039 if (ret <= 0)
4040 goto out;
4041 /*
4042 * Flag the inode(non aio case) or end_io struct (aio case)
4043 * that this IO needs to conversion to written when IO is
4044 * completed
4045 */
4046 if (io)
4047 ext4_set_io_unwritten_flag(inode, io);
4048 else
4049 ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
4050 map->m_flags |= EXT4_MAP_UNWRITTEN;
4051 goto out;
4052 }
4053 /* IO end_io complete, convert the filled extent to written */
4054 if (flags & EXT4_GET_BLOCKS_CONVERT) {
4055 ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
4056 ppath);
4057 if (ret >= 0) {
4058 ext4_update_inode_fsync_trans(handle, inode, 1);
4059 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4060 path, map->m_len);
4061 } else
4062 err = ret;
4063 map->m_flags |= EXT4_MAP_MAPPED;
4064 map->m_pblk = newblock;
4065 if (allocated > map->m_len)
4066 allocated = map->m_len;
4067 map->m_len = allocated;
4068 goto out2;
4069 }
4070 /* buffered IO case */
4071 /*
4072 * repeat fallocate creation request
4073 * we already have an unwritten extent
4074 */
4075 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
4076 map->m_flags |= EXT4_MAP_UNWRITTEN;
4077 goto map_out;
4078 }
4079
4080 /* buffered READ or buffered write_begin() lookup */
4081 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4082 /*
4083 * We have blocks reserved already. We
4084 * return allocated blocks so that delalloc
4085 * won't do block reservation for us. But
4086 * the buffer head will be unmapped so that
4087 * a read from the block returns 0s.
4088 */
4089 map->m_flags |= EXT4_MAP_UNWRITTEN;
4090 goto out1;
4091 }
4092
4093 /* buffered write, writepage time, convert*/
4094 ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags);
4095 if (ret >= 0)
4096 ext4_update_inode_fsync_trans(handle, inode, 1);
4097 out:
4098 if (ret <= 0) {
4099 err = ret;
4100 goto out2;
4101 } else
4102 allocated = ret;
4103 map->m_flags |= EXT4_MAP_NEW;
4104 /*
4105 * if we allocated more blocks than requested
4106 * we need to make sure we unmap the extra block
4107 * allocated. The actual needed block will get
4108 * unmapped later when we find the buffer_head marked
4109 * new.
4110 */
4111 if (allocated > map->m_len) {
4112 unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
4113 newblock + map->m_len,
4114 allocated - map->m_len);
4115 allocated = map->m_len;
4116 }
4117 map->m_len = allocated;
4118
4119 /*
4120 * If we have done fallocate with the offset that is already
4121 * delayed allocated, we would have block reservation
4122 * and quota reservation done in the delayed write path.
4123 * But fallocate would have already updated quota and block
4124 * count for this offset. So cancel these reservation
4125 */
4126 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4127 unsigned int reserved_clusters;
4128 reserved_clusters = get_reserved_cluster_alloc(inode,
4129 map->m_lblk, map->m_len);
4130 if (reserved_clusters)
4131 ext4_da_update_reserve_space(inode,
4132 reserved_clusters,
4133 0);
4134 }
4135
4136 map_out:
4137 map->m_flags |= EXT4_MAP_MAPPED;
4138 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
4139 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
4140 map->m_len);
4141 if (err < 0)
4142 goto out2;
4143 }
4144 out1:
4145 if (allocated > map->m_len)
4146 allocated = map->m_len;
4147 ext4_ext_show_leaf(inode, path);
4148 map->m_pblk = newblock;
4149 map->m_len = allocated;
4150 out2:
4151 return err ? err : allocated;
4152 }
4153
4154 /*
4155 * get_implied_cluster_alloc - check to see if the requested
4156 * allocation (in the map structure) overlaps with a cluster already
4157 * allocated in an extent.
4158 * @sb The filesystem superblock structure
4159 * @map The requested lblk->pblk mapping
4160 * @ex The extent structure which might contain an implied
4161 * cluster allocation
4162 *
4163 * This function is called by ext4_ext_map_blocks() after we failed to
4164 * find blocks that were already in the inode's extent tree. Hence,
4165 * we know that the beginning of the requested region cannot overlap
4166 * the extent from the inode's extent tree. There are three cases we
4167 * want to catch. The first is this case:
4168 *
4169 * |--- cluster # N--|
4170 * |--- extent ---| |---- requested region ---|
4171 * |==========|
4172 *
4173 * The second case that we need to test for is this one:
4174 *
4175 * |--------- cluster # N ----------------|
4176 * |--- requested region --| |------- extent ----|
4177 * |=======================|
4178 *
4179 * The third case is when the requested region lies between two extents
4180 * within the same cluster:
4181 * |------------- cluster # N-------------|
4182 * |----- ex -----| |---- ex_right ----|
4183 * |------ requested region ------|
4184 * |================|
4185 *
4186 * In each of the above cases, we need to set the map->m_pblk and
4187 * map->m_len so it corresponds to the return the extent labelled as
4188 * "|====|" from cluster #N, since it is already in use for data in
4189 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
4190 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
4191 * as a new "allocated" block region. Otherwise, we will return 0 and
4192 * ext4_ext_map_blocks() will then allocate one or more new clusters
4193 * by calling ext4_mb_new_blocks().
4194 */
4195 static int get_implied_cluster_alloc(struct super_block *sb,
4196 struct ext4_map_blocks *map,
4197 struct ext4_extent *ex,
4198 struct ext4_ext_path *path)
4199 {
4200 struct ext4_sb_info *sbi = EXT4_SB(sb);
4201 ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4202 ext4_lblk_t ex_cluster_start, ex_cluster_end;
4203 ext4_lblk_t rr_cluster_start;
4204 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4205 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4206 unsigned short ee_len = ext4_ext_get_actual_len(ex);
4207
4208 /* The extent passed in that we are trying to match */
4209 ex_cluster_start = EXT4_B2C(sbi, ee_block);
4210 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
4211
4212 /* The requested region passed into ext4_map_blocks() */
4213 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
4214
4215 if ((rr_cluster_start == ex_cluster_end) ||
4216 (rr_cluster_start == ex_cluster_start)) {
4217 if (rr_cluster_start == ex_cluster_end)
4218 ee_start += ee_len - 1;
4219 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
4220 map->m_len = min(map->m_len,
4221 (unsigned) sbi->s_cluster_ratio - c_offset);
4222 /*
4223 * Check for and handle this case:
4224 *
4225 * |--------- cluster # N-------------|
4226 * |------- extent ----|
4227 * |--- requested region ---|
4228 * |===========|
4229 */
4230
4231 if (map->m_lblk < ee_block)
4232 map->m_len = min(map->m_len, ee_block - map->m_lblk);
4233
4234 /*
4235 * Check for the case where there is already another allocated
4236 * block to the right of 'ex' but before the end of the cluster.
4237 *
4238 * |------------- cluster # N-------------|
4239 * |----- ex -----| |---- ex_right ----|
4240 * |------ requested region ------|
4241 * |================|
4242 */
4243 if (map->m_lblk > ee_block) {
4244 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4245 map->m_len = min(map->m_len, next - map->m_lblk);
4246 }
4247
4248 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4249 return 1;
4250 }
4251
4252 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4253 return 0;
4254 }
4255
4256
4257 /*
4258 * Block allocation/map/preallocation routine for extents based files
4259 *
4260 *
4261 * Need to be called with
4262 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4263 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4264 *
4265 * return > 0, number of of blocks already mapped/allocated
4266 * if create == 0 and these are pre-allocated blocks
4267 * buffer head is unmapped
4268 * otherwise blocks are mapped
4269 *
4270 * return = 0, if plain look up failed (blocks have not been allocated)
4271 * buffer head is unmapped
4272 *
4273 * return < 0, error case.
4274 */
4275 int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4276 struct ext4_map_blocks *map, int flags)
4277 {
4278 struct ext4_ext_path *path = NULL;
4279 struct ext4_extent newex, *ex, *ex2;
4280 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4281 ext4_fsblk_t newblock = 0;
4282 int free_on_err = 0, err = 0, depth, ret;
4283 unsigned int allocated = 0, offset = 0;
4284 unsigned int allocated_clusters = 0;
4285 struct ext4_allocation_request ar;
4286 ext4_io_end_t *io = ext4_inode_aio(inode);
4287 ext4_lblk_t cluster_offset;
4288 int set_unwritten = 0;
4289 bool map_from_cluster = false;
4290
4291 ext_debug("blocks %u/%u requested for inode %lu\n",
4292 map->m_lblk, map->m_len, inode->i_ino);
4293 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4294
4295 /* find extent for this block */
4296 path = ext4_find_extent(inode, map->m_lblk, NULL, 0);
4297 if (IS_ERR(path)) {
4298 err = PTR_ERR(path);
4299 path = NULL;
4300 goto out2;
4301 }
4302
4303 depth = ext_depth(inode);
4304
4305 /*
4306 * consistent leaf must not be empty;
4307 * this situation is possible, though, _during_ tree modification;
4308 * this is why assert can't be put in ext4_find_extent()
4309 */
4310 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4311 EXT4_ERROR_INODE(inode, "bad extent address "
4312 "lblock: %lu, depth: %d pblock %lld",
4313 (unsigned long) map->m_lblk, depth,
4314 path[depth].p_block);
4315 err = -EFSCORRUPTED;
4316 goto out2;
4317 }
4318
4319 ex = path[depth].p_ext;
4320 if (ex) {
4321 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4322 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4323 unsigned short ee_len;
4324
4325
4326 /*
4327 * unwritten extents are treated as holes, except that
4328 * we split out initialized portions during a write.
4329 */
4330 ee_len = ext4_ext_get_actual_len(ex);
4331
4332 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4333
4334 /* if found extent covers block, simply return it */
4335 if (in_range(map->m_lblk, ee_block, ee_len)) {
4336 newblock = map->m_lblk - ee_block + ee_start;
4337 /* number of remaining blocks in the extent */
4338 allocated = ee_len - (map->m_lblk - ee_block);
4339 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
4340 ee_block, ee_len, newblock);
4341
4342 /*
4343 * If the extent is initialized check whether the
4344 * caller wants to convert it to unwritten.
4345 */
4346 if ((!ext4_ext_is_unwritten(ex)) &&
4347 (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
4348 allocated = convert_initialized_extent(
4349 handle, inode, map, &path,
4350 flags, allocated, newblock);
4351 goto out2;
4352 } else if (!ext4_ext_is_unwritten(ex))
4353 goto out;
4354
4355 ret = ext4_ext_handle_unwritten_extents(
4356 handle, inode, map, &path, flags,
4357 allocated, newblock);
4358 if (ret < 0)
4359 err = ret;
4360 else
4361 allocated = ret;
4362 goto out2;
4363 }
4364 }
4365
4366 /*
4367 * requested block isn't allocated yet;
4368 * we couldn't try to create block if create flag is zero
4369 */
4370 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4371 /*
4372 * put just found gap into cache to speed up
4373 * subsequent requests
4374 */
4375 ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
4376 goto out2;
4377 }
4378
4379 /*
4380 * Okay, we need to do block allocation.
4381 */
4382 newex.ee_block = cpu_to_le32(map->m_lblk);
4383 cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4384
4385 /*
4386 * If we are doing bigalloc, check to see if the extent returned
4387 * by ext4_find_extent() implies a cluster we can use.
4388 */
4389 if (cluster_offset && ex &&
4390 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4391 ar.len = allocated = map->m_len;
4392 newblock = map->m_pblk;
4393 map_from_cluster = true;
4394 goto got_allocated_blocks;
4395 }
4396
4397 /* find neighbour allocated blocks */
4398 ar.lleft = map->m_lblk;
4399 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4400 if (err)
4401 goto out2;
4402 ar.lright = map->m_lblk;
4403 ex2 = NULL;
4404 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4405 if (err)
4406 goto out2;
4407
4408 /* Check if the extent after searching to the right implies a
4409 * cluster we can use. */
4410 if ((sbi->s_cluster_ratio > 1) && ex2 &&
4411 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
4412 ar.len = allocated = map->m_len;
4413 newblock = map->m_pblk;
4414 map_from_cluster = true;
4415 goto got_allocated_blocks;
4416 }
4417
4418 /*
4419 * See if request is beyond maximum number of blocks we can have in
4420 * a single extent. For an initialized extent this limit is
4421 * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
4422 * EXT_UNWRITTEN_MAX_LEN.
4423 */
4424 if (map->m_len > EXT_INIT_MAX_LEN &&
4425 !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4426 map->m_len = EXT_INIT_MAX_LEN;
4427 else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
4428 (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4429 map->m_len = EXT_UNWRITTEN_MAX_LEN;
4430
4431 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4432 newex.ee_len = cpu_to_le16(map->m_len);
4433 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4434 if (err)
4435 allocated = ext4_ext_get_actual_len(&newex);
4436 else
4437 allocated = map->m_len;
4438
4439 /* allocate new block */
4440 ar.inode = inode;
4441 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4442 ar.logical = map->m_lblk;
4443 /*
4444 * We calculate the offset from the beginning of the cluster
4445 * for the logical block number, since when we allocate a
4446 * physical cluster, the physical block should start at the
4447 * same offset from the beginning of the cluster. This is
4448 * needed so that future calls to get_implied_cluster_alloc()
4449 * work correctly.
4450 */
4451 offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4452 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4453 ar.goal -= offset;
4454 ar.logical -= offset;
4455 if (S_ISREG(inode->i_mode))
4456 ar.flags = EXT4_MB_HINT_DATA;
4457 else
4458 /* disable in-core preallocation for non-regular files */
4459 ar.flags = 0;
4460 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4461 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4462 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4463 ar.flags |= EXT4_MB_DELALLOC_RESERVED;
4464 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
4465 ar.flags |= EXT4_MB_USE_RESERVED;
4466 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4467 if (!newblock)
4468 goto out2;
4469 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4470 ar.goal, newblock, allocated);
4471 free_on_err = 1;
4472 allocated_clusters = ar.len;
4473 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4474 if (ar.len > allocated)
4475 ar.len = allocated;
4476
4477 got_allocated_blocks:
4478 /* try to insert new extent into found leaf and return */
4479 ext4_ext_store_pblock(&newex, newblock + offset);
4480 newex.ee_len = cpu_to_le16(ar.len);
4481 /* Mark unwritten */
4482 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){
4483 ext4_ext_mark_unwritten(&newex);
4484 map->m_flags |= EXT4_MAP_UNWRITTEN;
4485 /*
4486 * io_end structure was created for every IO write to an
4487 * unwritten extent. To avoid unnecessary conversion,
4488 * here we flag the IO that really needs the conversion.
4489 * For non asycn direct IO case, flag the inode state
4490 * that we need to perform conversion when IO is done.
4491 */
4492 if (flags & EXT4_GET_BLOCKS_PRE_IO)
4493 set_unwritten = 1;
4494 }
4495
4496 err = 0;
4497 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4498 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4499 path, ar.len);
4500 if (!err)
4501 err = ext4_ext_insert_extent(handle, inode, &path,
4502 &newex, flags);
4503
4504 if (!err && set_unwritten) {
4505 if (io)
4506 ext4_set_io_unwritten_flag(inode, io);
4507 else
4508 ext4_set_inode_state(inode,
4509 EXT4_STATE_DIO_UNWRITTEN);
4510 }
4511
4512 if (err && free_on_err) {
4513 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4514 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4515 /* free data blocks we just allocated */
4516 /* not a good idea to call discard here directly,
4517 * but otherwise we'd need to call it every free() */
4518 ext4_discard_preallocations(inode);
4519 ext4_free_blocks(handle, inode, NULL, newblock,
4520 EXT4_C2B(sbi, allocated_clusters), fb_flags);
4521 goto out2;
4522 }
4523
4524 /* previous routine could use block we allocated */
4525 newblock = ext4_ext_pblock(&newex);
4526 allocated = ext4_ext_get_actual_len(&newex);
4527 if (allocated > map->m_len)
4528 allocated = map->m_len;
4529 map->m_flags |= EXT4_MAP_NEW;
4530
4531 /*
4532 * Update reserved blocks/metadata blocks after successful
4533 * block allocation which had been deferred till now.
4534 */
4535 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4536 unsigned int reserved_clusters;
4537 /*
4538 * Check how many clusters we had reserved this allocated range
4539 */
4540 reserved_clusters = get_reserved_cluster_alloc(inode,
4541 map->m_lblk, allocated);
4542 if (!map_from_cluster) {
4543 BUG_ON(allocated_clusters < reserved_clusters);
4544 if (reserved_clusters < allocated_clusters) {
4545 struct ext4_inode_info *ei = EXT4_I(inode);
4546 int reservation = allocated_clusters -
4547 reserved_clusters;
4548 /*
4549 * It seems we claimed few clusters outside of
4550 * the range of this allocation. We should give
4551 * it back to the reservation pool. This can
4552 * happen in the following case:
4553 *
4554 * * Suppose s_cluster_ratio is 4 (i.e., each
4555 * cluster has 4 blocks. Thus, the clusters
4556 * are [0-3],[4-7],[8-11]...
4557 * * First comes delayed allocation write for
4558 * logical blocks 10 & 11. Since there were no
4559 * previous delayed allocated blocks in the
4560 * range [8-11], we would reserve 1 cluster
4561 * for this write.
4562 * * Next comes write for logical blocks 3 to 8.
4563 * In this case, we will reserve 2 clusters
4564 * (for [0-3] and [4-7]; and not for [8-11] as
4565 * that range has a delayed allocated blocks.
4566 * Thus total reserved clusters now becomes 3.
4567 * * Now, during the delayed allocation writeout
4568 * time, we will first write blocks [3-8] and
4569 * allocate 3 clusters for writing these
4570 * blocks. Also, we would claim all these
4571 * three clusters above.
4572 * * Now when we come here to writeout the
4573 * blocks [10-11], we would expect to claim
4574 * the reservation of 1 cluster we had made
4575 * (and we would claim it since there are no
4576 * more delayed allocated blocks in the range
4577 * [8-11]. But our reserved cluster count had
4578 * already gone to 0.
4579 *
4580 * Thus, at the step 4 above when we determine
4581 * that there are still some unwritten delayed
4582 * allocated blocks outside of our current
4583 * block range, we should increment the
4584 * reserved clusters count so that when the
4585 * remaining blocks finally gets written, we
4586 * could claim them.
4587 */
4588 dquot_reserve_block(inode,
4589 EXT4_C2B(sbi, reservation));
4590 spin_lock(&ei->i_block_reservation_lock);
4591 ei->i_reserved_data_blocks += reservation;
4592 spin_unlock(&ei->i_block_reservation_lock);
4593 }
4594 /*
4595 * We will claim quota for all newly allocated blocks.
4596 * We're updating the reserved space *after* the
4597 * correction above so we do not accidentally free
4598 * all the metadata reservation because we might
4599 * actually need it later on.
4600 */
4601 ext4_da_update_reserve_space(inode, allocated_clusters,
4602 1);
4603 }
4604 }
4605
4606 /*
4607 * Cache the extent and update transaction to commit on fdatasync only
4608 * when it is _not_ an unwritten extent.
4609 */
4610 if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
4611 ext4_update_inode_fsync_trans(handle, inode, 1);
4612 else
4613 ext4_update_inode_fsync_trans(handle, inode, 0);
4614 out:
4615 if (allocated > map->m_len)
4616 allocated = map->m_len;
4617 ext4_ext_show_leaf(inode, path);
4618 map->m_flags |= EXT4_MAP_MAPPED;
4619 map->m_pblk = newblock;
4620 map->m_len = allocated;
4621 out2:
4622 ext4_ext_drop_refs(path);
4623 kfree(path);
4624
4625 trace_ext4_ext_map_blocks_exit(inode, flags, map,
4626 err ? err : allocated);
4627 return err ? err : allocated;
4628 }
4629
4630 void ext4_ext_truncate(handle_t *handle, struct inode *inode)
4631 {
4632 struct super_block *sb = inode->i_sb;
4633 ext4_lblk_t last_block;
4634 int err = 0;
4635
4636 /*
4637 * TODO: optimization is possible here.
4638 * Probably we need not scan at all,
4639 * because page truncation is enough.
4640 */
4641
4642 /* we have to know where to truncate from in crash case */
4643 EXT4_I(inode)->i_disksize = inode->i_size;
4644 ext4_mark_inode_dirty(handle, inode);
4645
4646 last_block = (inode->i_size + sb->s_blocksize - 1)
4647 >> EXT4_BLOCK_SIZE_BITS(sb);
4648 retry:
4649 err = ext4_es_remove_extent(inode, last_block,
4650 EXT_MAX_BLOCKS - last_block);
4651 if (err == -ENOMEM) {
4652 cond_resched();
4653 congestion_wait(BLK_RW_ASYNC, HZ/50);
4654 goto retry;
4655 }
4656 if (err) {
4657 ext4_std_error(inode->i_sb, err);
4658 return;
4659 }
4660 err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4661 ext4_std_error(inode->i_sb, err);
4662 }
4663
4664 static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
4665 ext4_lblk_t len, loff_t new_size,
4666 int flags, int mode)
4667 {
4668 struct inode *inode = file_inode(file);
4669 handle_t *handle;
4670 int ret = 0;
4671 int ret2 = 0;
4672 int retries = 0;
4673 int depth = 0;
4674 struct ext4_map_blocks map;
4675 unsigned int credits;
4676 loff_t epos;
4677
4678 map.m_lblk = offset;
4679 map.m_len = len;
4680 /*
4681 * Don't normalize the request if it can fit in one extent so
4682 * that it doesn't get unnecessarily split into multiple
4683 * extents.
4684 */
4685 if (len <= EXT_UNWRITTEN_MAX_LEN)
4686 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4687
4688 /* Wait all existing dio workers, newcomers will block on i_mutex */
4689 ext4_inode_block_unlocked_dio(inode);
4690 inode_dio_wait(inode);
4691
4692 /*
4693 * credits to insert 1 extent into extent tree
4694 */
4695 credits = ext4_chunk_trans_blocks(inode, len);
4696 /*
4697 * We can only call ext_depth() on extent based inodes
4698 */
4699 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
4700 depth = ext_depth(inode);
4701 else
4702 depth = -1;
4703
4704 retry:
4705 while (ret >= 0 && len) {
4706 /*
4707 * Recalculate credits when extent tree depth changes.
4708 */
4709 if (depth >= 0 && depth != ext_depth(inode)) {
4710 credits = ext4_chunk_trans_blocks(inode, len);
4711 depth = ext_depth(inode);
4712 }
4713
4714 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4715 credits);
4716 if (IS_ERR(handle)) {
4717 ret = PTR_ERR(handle);
4718 break;
4719 }
4720 ret = ext4_map_blocks(handle, inode, &map, flags);
4721 if (ret <= 0) {
4722 ext4_debug("inode #%lu: block %u: len %u: "
4723 "ext4_ext_map_blocks returned %d",
4724 inode->i_ino, map.m_lblk,
4725 map.m_len, ret);
4726 ext4_mark_inode_dirty(handle, inode);
4727 ret2 = ext4_journal_stop(handle);
4728 break;
4729 }
4730 map.m_lblk += ret;
4731 map.m_len = len = len - ret;
4732 epos = (loff_t)map.m_lblk << inode->i_blkbits;
4733 inode->i_ctime = ext4_current_time(inode);
4734 if (new_size) {
4735 if (epos > new_size)
4736 epos = new_size;
4737 if (ext4_update_inode_size(inode, epos) & 0x1)
4738 inode->i_mtime = inode->i_ctime;
4739 } else {
4740 if (epos > inode->i_size)
4741 ext4_set_inode_flag(inode,
4742 EXT4_INODE_EOFBLOCKS);
4743 }
4744 ext4_mark_inode_dirty(handle, inode);
4745 ret2 = ext4_journal_stop(handle);
4746 if (ret2)
4747 break;
4748 }
4749 if (ret == -ENOSPC &&
4750 ext4_should_retry_alloc(inode->i_sb, &retries)) {
4751 ret = 0;
4752 goto retry;
4753 }
4754
4755 ext4_inode_resume_unlocked_dio(inode);
4756
4757 return ret > 0 ? ret2 : ret;
4758 }
4759
4760 static long ext4_zero_range(struct file *file, loff_t offset,
4761 loff_t len, int mode)
4762 {
4763 struct inode *inode = file_inode(file);
4764 handle_t *handle = NULL;
4765 unsigned int max_blocks;
4766 loff_t new_size = 0;
4767 int ret = 0;
4768 int flags;
4769 int credits;
4770 int partial_begin, partial_end;
4771 loff_t start, end;
4772 ext4_lblk_t lblk;
4773 struct address_space *mapping = inode->i_mapping;
4774 unsigned int blkbits = inode->i_blkbits;
4775
4776 trace_ext4_zero_range(inode, offset, len, mode);
4777
4778 if (!S_ISREG(inode->i_mode))
4779 return -EINVAL;
4780
4781 /* Call ext4_force_commit to flush all data in case of data=journal. */
4782 if (ext4_should_journal_data(inode)) {
4783 ret = ext4_force_commit(inode->i_sb);
4784 if (ret)
4785 return ret;
4786 }
4787
4788 /*
4789 * Write out all dirty pages to avoid race conditions
4790 * Then release them.
4791 */
4792 if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
4793 ret = filemap_write_and_wait_range(mapping, offset,
4794 offset + len - 1);
4795 if (ret)
4796 return ret;
4797 }
4798
4799 /*
4800 * Round up offset. This is not fallocate, we neet to zero out
4801 * blocks, so convert interior block aligned part of the range to
4802 * unwritten and possibly manually zero out unaligned parts of the
4803 * range.
4804 */
4805 start = round_up(offset, 1 << blkbits);
4806 end = round_down((offset + len), 1 << blkbits);
4807
4808 if (start < offset || end > offset + len)
4809 return -EINVAL;
4810 partial_begin = offset & ((1 << blkbits) - 1);
4811 partial_end = (offset + len) & ((1 << blkbits) - 1);
4812
4813 lblk = start >> blkbits;
4814 max_blocks = (end >> blkbits);
4815 if (max_blocks < lblk)
4816 max_blocks = 0;
4817 else
4818 max_blocks -= lblk;
4819
4820 mutex_lock(&inode->i_mutex);
4821
4822 /*
4823 * Indirect files do not support unwritten extnets
4824 */
4825 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4826 ret = -EOPNOTSUPP;
4827 goto out_mutex;
4828 }
4829
4830 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4831 offset + len > i_size_read(inode)) {
4832 new_size = offset + len;
4833 ret = inode_newsize_ok(inode, new_size);
4834 if (ret)
4835 goto out_mutex;
4836 }
4837
4838 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4839 if (mode & FALLOC_FL_KEEP_SIZE)
4840 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4841
4842 /* Preallocate the range including the unaligned edges */
4843 if (partial_begin || partial_end) {
4844 ret = ext4_alloc_file_blocks(file,
4845 round_down(offset, 1 << blkbits) >> blkbits,
4846 (round_up((offset + len), 1 << blkbits) -
4847 round_down(offset, 1 << blkbits)) >> blkbits,
4848 new_size, flags, mode);
4849 if (ret)
4850 goto out_mutex;
4851
4852 }
4853
4854 /* Zero range excluding the unaligned edges */
4855 if (max_blocks > 0) {
4856 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
4857 EXT4_EX_NOCACHE);
4858
4859 /* Now release the pages and zero block aligned part of pages*/
4860 truncate_pagecache_range(inode, start, end - 1);
4861 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4862
4863 /* Wait all existing dio workers, newcomers will block on i_mutex */
4864 ext4_inode_block_unlocked_dio(inode);
4865 inode_dio_wait(inode);
4866
4867 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4868 flags, mode);
4869 if (ret)
4870 goto out_dio;
4871 }
4872 if (!partial_begin && !partial_end)
4873 goto out_dio;
4874
4875 /*
4876 * In worst case we have to writeout two nonadjacent unwritten
4877 * blocks and update the inode
4878 */
4879 credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
4880 if (ext4_should_journal_data(inode))
4881 credits += 2;
4882 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
4883 if (IS_ERR(handle)) {
4884 ret = PTR_ERR(handle);
4885 ext4_std_error(inode->i_sb, ret);
4886 goto out_dio;
4887 }
4888
4889 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4890 if (new_size) {
4891 ext4_update_inode_size(inode, new_size);
4892 } else {
4893 /*
4894 * Mark that we allocate beyond EOF so the subsequent truncate
4895 * can proceed even if the new size is the same as i_size.
4896 */
4897 if ((offset + len) > i_size_read(inode))
4898 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4899 }
4900 ext4_mark_inode_dirty(handle, inode);
4901
4902 /* Zero out partial block at the edges of the range */
4903 ret = ext4_zero_partial_blocks(handle, inode, offset, len);
4904
4905 if (file->f_flags & O_SYNC)
4906 ext4_handle_sync(handle);
4907
4908 ext4_journal_stop(handle);
4909 out_dio:
4910 ext4_inode_resume_unlocked_dio(inode);
4911 out_mutex:
4912 mutex_unlock(&inode->i_mutex);
4913 return ret;
4914 }
4915
4916 /*
4917 * preallocate space for a file. This implements ext4's fallocate file
4918 * operation, which gets called from sys_fallocate system call.
4919 * For block-mapped files, posix_fallocate should fall back to the method
4920 * of writing zeroes to the required new blocks (the same behavior which is
4921 * expected for file systems which do not support fallocate() system call).
4922 */
4923 long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4924 {
4925 struct inode *inode = file_inode(file);
4926 loff_t new_size = 0;
4927 unsigned int max_blocks;
4928 int ret = 0;
4929 int flags;
4930 ext4_lblk_t lblk;
4931 unsigned int blkbits = inode->i_blkbits;
4932
4933 /*
4934 * Encrypted inodes can't handle collapse range or insert
4935 * range since we would need to re-encrypt blocks with a
4936 * different IV or XTS tweak (which are based on the logical
4937 * block number).
4938 *
4939 * XXX It's not clear why zero range isn't working, but we'll
4940 * leave it disabled for encrypted inodes for now. This is a
4941 * bug we should fix....
4942 */
4943 if (ext4_encrypted_inode(inode) &&
4944 (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE |
4945 FALLOC_FL_ZERO_RANGE)))
4946 return -EOPNOTSUPP;
4947
4948 /* Return error if mode is not supported */
4949 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
4950 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
4951 FALLOC_FL_INSERT_RANGE))
4952 return -EOPNOTSUPP;
4953
4954 if (mode & FALLOC_FL_PUNCH_HOLE)
4955 return ext4_punch_hole(inode, offset, len);
4956
4957 ret = ext4_convert_inline_data(inode);
4958 if (ret)
4959 return ret;
4960
4961 if (mode & FALLOC_FL_COLLAPSE_RANGE)
4962 return ext4_collapse_range(inode, offset, len);
4963
4964 if (mode & FALLOC_FL_INSERT_RANGE)
4965 return ext4_insert_range(inode, offset, len);
4966
4967 if (mode & FALLOC_FL_ZERO_RANGE)
4968 return ext4_zero_range(file, offset, len, mode);
4969
4970 trace_ext4_fallocate_enter(inode, offset, len, mode);
4971 lblk = offset >> blkbits;
4972 /*
4973 * We can't just convert len to max_blocks because
4974 * If blocksize = 4096 offset = 3072 and len = 2048
4975 */
4976 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
4977 - lblk;
4978
4979 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4980 if (mode & FALLOC_FL_KEEP_SIZE)
4981 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4982
4983 mutex_lock(&inode->i_mutex);
4984
4985 /*
4986 * We only support preallocation for extent-based files only
4987 */
4988 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4989 ret = -EOPNOTSUPP;
4990 goto out;
4991 }
4992
4993 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4994 offset + len > i_size_read(inode)) {
4995 new_size = offset + len;
4996 ret = inode_newsize_ok(inode, new_size);
4997 if (ret)
4998 goto out;
4999 }
5000
5001 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
5002 flags, mode);
5003 if (ret)
5004 goto out;
5005
5006 if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
5007 ret = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal,
5008 EXT4_I(inode)->i_sync_tid);
5009 }
5010 out:
5011 mutex_unlock(&inode->i_mutex);
5012 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
5013 return ret;
5014 }
5015
5016 /*
5017 * This function convert a range of blocks to written extents
5018 * The caller of this function will pass the start offset and the size.
5019 * all unwritten extents within this range will be converted to
5020 * written extents.
5021 *
5022 * This function is called from the direct IO end io call back
5023 * function, to convert the fallocated extents after IO is completed.
5024 * Returns 0 on success.
5025 */
5026 int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
5027 loff_t offset, ssize_t len)
5028 {
5029 unsigned int max_blocks;
5030 int ret = 0;
5031 int ret2 = 0;
5032 struct ext4_map_blocks map;
5033 unsigned int credits, blkbits = inode->i_blkbits;
5034
5035 map.m_lblk = offset >> blkbits;
5036 /*
5037 * We can't just convert len to max_blocks because
5038 * If blocksize = 4096 offset = 3072 and len = 2048
5039 */
5040 max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
5041 map.m_lblk);
5042 /*
5043 * This is somewhat ugly but the idea is clear: When transaction is
5044 * reserved, everything goes into it. Otherwise we rather start several
5045 * smaller transactions for conversion of each extent separately.
5046 */
5047 if (handle) {
5048 handle = ext4_journal_start_reserved(handle,
5049 EXT4_HT_EXT_CONVERT);
5050 if (IS_ERR(handle))
5051 return PTR_ERR(handle);
5052 credits = 0;
5053 } else {
5054 /*
5055 * credits to insert 1 extent into extent tree
5056 */
5057 credits = ext4_chunk_trans_blocks(inode, max_blocks);
5058 }
5059 while (ret >= 0 && ret < max_blocks) {
5060 map.m_lblk += ret;
5061 map.m_len = (max_blocks -= ret);
5062 if (credits) {
5063 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
5064 credits);
5065 if (IS_ERR(handle)) {
5066 ret = PTR_ERR(handle);
5067 break;
5068 }
5069 }
5070 ret = ext4_map_blocks(handle, inode, &map,
5071 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
5072 if (ret <= 0)
5073 ext4_warning(inode->i_sb,
5074 "inode #%lu: block %u: len %u: "
5075 "ext4_ext_map_blocks returned %d",
5076 inode->i_ino, map.m_lblk,
5077 map.m_len, ret);
5078 ext4_mark_inode_dirty(handle, inode);
5079 if (credits)
5080 ret2 = ext4_journal_stop(handle);
5081 if (ret <= 0 || ret2)
5082 break;
5083 }
5084 if (!credits)
5085 ret2 = ext4_journal_stop(handle);
5086 return ret > 0 ? ret2 : ret;
5087 }
5088
5089 /*
5090 * If newes is not existing extent (newes->ec_pblk equals zero) find
5091 * delayed extent at start of newes and update newes accordingly and
5092 * return start of the next delayed extent.
5093 *
5094 * If newes is existing extent (newes->ec_pblk is not equal zero)
5095 * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
5096 * extent found. Leave newes unmodified.
5097 */
5098 static int ext4_find_delayed_extent(struct inode *inode,
5099 struct extent_status *newes)
5100 {
5101 struct extent_status es;
5102 ext4_lblk_t block, next_del;
5103
5104 if (newes->es_pblk == 0) {
5105 ext4_es_find_delayed_extent_range(inode, newes->es_lblk,
5106 newes->es_lblk + newes->es_len - 1, &es);
5107
5108 /*
5109 * No extent in extent-tree contains block @newes->es_pblk,
5110 * then the block may stay in 1)a hole or 2)delayed-extent.
5111 */
5112 if (es.es_len == 0)
5113 /* A hole found. */
5114 return 0;
5115
5116 if (es.es_lblk > newes->es_lblk) {
5117 /* A hole found. */
5118 newes->es_len = min(es.es_lblk - newes->es_lblk,
5119 newes->es_len);
5120 return 0;
5121 }
5122
5123 newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
5124 }
5125
5126 block = newes->es_lblk + newes->es_len;
5127 ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es);
5128 if (es.es_len == 0)
5129 next_del = EXT_MAX_BLOCKS;
5130 else
5131 next_del = es.es_lblk;
5132
5133 return next_del;
5134 }
5135 /* fiemap flags we can handle specified here */
5136 #define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
5137
5138 static int ext4_xattr_fiemap(struct inode *inode,
5139 struct fiemap_extent_info *fieinfo)
5140 {
5141 __u64 physical = 0;
5142 __u64 length;
5143 __u32 flags = FIEMAP_EXTENT_LAST;
5144 int blockbits = inode->i_sb->s_blocksize_bits;
5145 int error = 0;
5146
5147 /* in-inode? */
5148 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
5149 struct ext4_iloc iloc;
5150 int offset; /* offset of xattr in inode */
5151
5152 error = ext4_get_inode_loc(inode, &iloc);
5153 if (error)
5154 return error;
5155 physical = (__u64)iloc.bh->b_blocknr << blockbits;
5156 offset = EXT4_GOOD_OLD_INODE_SIZE +
5157 EXT4_I(inode)->i_extra_isize;
5158 physical += offset;
5159 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
5160 flags |= FIEMAP_EXTENT_DATA_INLINE;
5161 brelse(iloc.bh);
5162 } else { /* external block */
5163 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
5164 length = inode->i_sb->s_blocksize;
5165 }
5166
5167 if (physical)
5168 error = fiemap_fill_next_extent(fieinfo, 0, physical,
5169 length, flags);
5170 return (error < 0 ? error : 0);
5171 }
5172
5173 int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
5174 __u64 start, __u64 len)
5175 {
5176 ext4_lblk_t start_blk;
5177 int error = 0;
5178
5179 if (ext4_has_inline_data(inode)) {
5180 int has_inline = 1;
5181
5182 error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
5183 start, len);
5184
5185 if (has_inline)
5186 return error;
5187 }
5188
5189 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
5190 error = ext4_ext_precache(inode);
5191 if (error)
5192 return error;
5193 }
5194
5195 /* fallback to generic here if not in extents fmt */
5196 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
5197 return generic_block_fiemap(inode, fieinfo, start, len,
5198 ext4_get_block);
5199
5200 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
5201 return -EBADR;
5202
5203 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
5204 error = ext4_xattr_fiemap(inode, fieinfo);
5205 } else {
5206 ext4_lblk_t len_blks;
5207 __u64 last_blk;
5208
5209 start_blk = start >> inode->i_sb->s_blocksize_bits;
5210 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
5211 if (last_blk >= EXT_MAX_BLOCKS)
5212 last_blk = EXT_MAX_BLOCKS-1;
5213 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
5214
5215 /*
5216 * Walk the extent tree gathering extent information
5217 * and pushing extents back to the user.
5218 */
5219 error = ext4_fill_fiemap_extents(inode, start_blk,
5220 len_blks, fieinfo);
5221 }
5222 return error;
5223 }
5224
5225 /*
5226 * ext4_access_path:
5227 * Function to access the path buffer for marking it dirty.
5228 * It also checks if there are sufficient credits left in the journal handle
5229 * to update path.
5230 */
5231 static int
5232 ext4_access_path(handle_t *handle, struct inode *inode,
5233 struct ext4_ext_path *path)
5234 {
5235 int credits, err;
5236
5237 if (!ext4_handle_valid(handle))
5238 return 0;
5239
5240 /*
5241 * Check if need to extend journal credits
5242 * 3 for leaf, sb, and inode plus 2 (bmap and group
5243 * descriptor) for each block group; assume two block
5244 * groups
5245 */
5246 if (handle->h_buffer_credits < 7) {
5247 credits = ext4_writepage_trans_blocks(inode);
5248 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
5249 /* EAGAIN is success */
5250 if (err && err != -EAGAIN)
5251 return err;
5252 }
5253
5254 err = ext4_ext_get_access(handle, inode, path);
5255 return err;
5256 }
5257
5258 /*
5259 * ext4_ext_shift_path_extents:
5260 * Shift the extents of a path structure lying between path[depth].p_ext
5261 * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
5262 * if it is right shift or left shift operation.
5263 */
5264 static int
5265 ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
5266 struct inode *inode, handle_t *handle,
5267 enum SHIFT_DIRECTION SHIFT)
5268 {
5269 int depth, err = 0;
5270 struct ext4_extent *ex_start, *ex_last;
5271 bool update = 0;
5272 depth = path->p_depth;
5273
5274 while (depth >= 0) {
5275 if (depth == path->p_depth) {
5276 ex_start = path[depth].p_ext;
5277 if (!ex_start)
5278 return -EFSCORRUPTED;
5279
5280 ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
5281
5282 err = ext4_access_path(handle, inode, path + depth);
5283 if (err)
5284 goto out;
5285
5286 if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr))
5287 update = 1;
5288
5289 while (ex_start <= ex_last) {
5290 if (SHIFT == SHIFT_LEFT) {
5291 le32_add_cpu(&ex_start->ee_block,
5292 -shift);
5293 /* Try to merge to the left. */
5294 if ((ex_start >
5295 EXT_FIRST_EXTENT(path[depth].p_hdr))
5296 &&
5297 ext4_ext_try_to_merge_right(inode,
5298 path, ex_start - 1))
5299 ex_last--;
5300 else
5301 ex_start++;
5302 } else {
5303 le32_add_cpu(&ex_last->ee_block, shift);
5304 ext4_ext_try_to_merge_right(inode, path,
5305 ex_last);
5306 ex_last--;
5307 }
5308 }
5309 err = ext4_ext_dirty(handle, inode, path + depth);
5310 if (err)
5311 goto out;
5312
5313 if (--depth < 0 || !update)
5314 break;
5315 }
5316
5317 /* Update index too */
5318 err = ext4_access_path(handle, inode, path + depth);
5319 if (err)
5320 goto out;
5321
5322 if (SHIFT == SHIFT_LEFT)
5323 le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
5324 else
5325 le32_add_cpu(&path[depth].p_idx->ei_block, shift);
5326 err = ext4_ext_dirty(handle, inode, path + depth);
5327 if (err)
5328 goto out;
5329
5330 /* we are done if current index is not a starting index */
5331 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
5332 break;
5333
5334 depth--;
5335 }
5336
5337 out:
5338 return err;
5339 }
5340
5341 /*
5342 * ext4_ext_shift_extents:
5343 * All the extents which lies in the range from @start to the last allocated
5344 * block for the @inode are shifted either towards left or right (depending
5345 * upon @SHIFT) by @shift blocks.
5346 * On success, 0 is returned, error otherwise.
5347 */
5348 static int
5349 ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
5350 ext4_lblk_t start, ext4_lblk_t shift,
5351 enum SHIFT_DIRECTION SHIFT)
5352 {
5353 struct ext4_ext_path *path;
5354 int ret = 0, depth;
5355 struct ext4_extent *extent;
5356 ext4_lblk_t stop, *iterator, ex_start, ex_end;
5357
5358 /* Let path point to the last extent */
5359 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 0);
5360 if (IS_ERR(path))
5361 return PTR_ERR(path);
5362
5363 depth = path->p_depth;
5364 extent = path[depth].p_ext;
5365 if (!extent)
5366 goto out;
5367
5368 stop = le32_to_cpu(extent->ee_block) +
5369 ext4_ext_get_actual_len(extent);
5370
5371 /*
5372 * In case of left shift, Don't start shifting extents until we make
5373 * sure the hole is big enough to accommodate the shift.
5374 */
5375 if (SHIFT == SHIFT_LEFT) {
5376 path = ext4_find_extent(inode, start - 1, &path, 0);
5377 if (IS_ERR(path))
5378 return PTR_ERR(path);
5379 depth = path->p_depth;
5380 extent = path[depth].p_ext;
5381 if (extent) {
5382 ex_start = le32_to_cpu(extent->ee_block);
5383 ex_end = le32_to_cpu(extent->ee_block) +
5384 ext4_ext_get_actual_len(extent);
5385 } else {
5386 ex_start = 0;
5387 ex_end = 0;
5388 }
5389
5390 if ((start == ex_start && shift > ex_start) ||
5391 (shift > start - ex_end)) {
5392 ext4_ext_drop_refs(path);
5393 kfree(path);
5394 return -EINVAL;
5395 }
5396 }
5397
5398 /*
5399 * In case of left shift, iterator points to start and it is increased
5400 * till we reach stop. In case of right shift, iterator points to stop
5401 * and it is decreased till we reach start.
5402 */
5403 if (SHIFT == SHIFT_LEFT)
5404 iterator = &start;
5405 else
5406 iterator = &stop;
5407
5408 /* Its safe to start updating extents */
5409 while (start < stop) {
5410 path = ext4_find_extent(inode, *iterator, &path, 0);
5411 if (IS_ERR(path))
5412 return PTR_ERR(path);
5413 depth = path->p_depth;
5414 extent = path[depth].p_ext;
5415 if (!extent) {
5416 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
5417 (unsigned long) *iterator);
5418 return -EFSCORRUPTED;
5419 }
5420 if (SHIFT == SHIFT_LEFT && *iterator >
5421 le32_to_cpu(extent->ee_block)) {
5422 /* Hole, move to the next extent */
5423 if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
5424 path[depth].p_ext++;
5425 } else {
5426 *iterator = ext4_ext_next_allocated_block(path);
5427 continue;
5428 }
5429 }
5430
5431 if (SHIFT == SHIFT_LEFT) {
5432 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5433 *iterator = le32_to_cpu(extent->ee_block) +
5434 ext4_ext_get_actual_len(extent);
5435 } else {
5436 extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
5437 *iterator = le32_to_cpu(extent->ee_block) > 0 ?
5438 le32_to_cpu(extent->ee_block) - 1 : 0;
5439 /* Update path extent in case we need to stop */
5440 while (le32_to_cpu(extent->ee_block) < start)
5441 extent++;
5442 path[depth].p_ext = extent;
5443 }
5444 ret = ext4_ext_shift_path_extents(path, shift, inode,
5445 handle, SHIFT);
5446 if (ret)
5447 break;
5448 }
5449 out:
5450 ext4_ext_drop_refs(path);
5451 kfree(path);
5452 return ret;
5453 }
5454
5455 /*
5456 * ext4_collapse_range:
5457 * This implements the fallocate's collapse range functionality for ext4
5458 * Returns: 0 and non-zero on error.
5459 */
5460 int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
5461 {
5462 struct super_block *sb = inode->i_sb;
5463 ext4_lblk_t punch_start, punch_stop;
5464 handle_t *handle;
5465 unsigned int credits;
5466 loff_t new_size, ioffset;
5467 int ret;
5468
5469 /*
5470 * We need to test this early because xfstests assumes that a
5471 * collapse range of (0, 1) will return EOPNOTSUPP if the file
5472 * system does not support collapse range.
5473 */
5474 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5475 return -EOPNOTSUPP;
5476
5477 /* Collapse range works only on fs block size aligned offsets. */
5478 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
5479 len & (EXT4_CLUSTER_SIZE(sb) - 1))
5480 return -EINVAL;
5481
5482 if (!S_ISREG(inode->i_mode))
5483 return -EINVAL;
5484
5485 trace_ext4_collapse_range(inode, offset, len);
5486
5487 punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5488 punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb);
5489
5490 /* Call ext4_force_commit to flush all data in case of data=journal. */
5491 if (ext4_should_journal_data(inode)) {
5492 ret = ext4_force_commit(inode->i_sb);
5493 if (ret)
5494 return ret;
5495 }
5496
5497 /*
5498 * Need to round down offset to be aligned with page size boundary
5499 * for page size > block size.
5500 */
5501 ioffset = round_down(offset, PAGE_SIZE);
5502
5503 /* Write out all dirty pages */
5504 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5505 LLONG_MAX);
5506 if (ret)
5507 return ret;
5508
5509 /* Take mutex lock */
5510 mutex_lock(&inode->i_mutex);
5511
5512 /*
5513 * There is no need to overlap collapse range with EOF, in which case
5514 * it is effectively a truncate operation
5515 */
5516 if (offset + len >= i_size_read(inode)) {
5517 ret = -EINVAL;
5518 goto out_mutex;
5519 }
5520
5521 /* Currently just for extent based files */
5522 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5523 ret = -EOPNOTSUPP;
5524 goto out_mutex;
5525 }
5526
5527 truncate_pagecache(inode, ioffset);
5528
5529 /* Wait for existing dio to complete */
5530 ext4_inode_block_unlocked_dio(inode);
5531 inode_dio_wait(inode);
5532
5533 credits = ext4_writepage_trans_blocks(inode);
5534 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5535 if (IS_ERR(handle)) {
5536 ret = PTR_ERR(handle);
5537 goto out_dio;
5538 }
5539
5540 down_write(&EXT4_I(inode)->i_data_sem);
5541 ext4_discard_preallocations(inode);
5542
5543 ret = ext4_es_remove_extent(inode, punch_start,
5544 EXT_MAX_BLOCKS - punch_start);
5545 if (ret) {
5546 up_write(&EXT4_I(inode)->i_data_sem);
5547 goto out_stop;
5548 }
5549
5550 ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
5551 if (ret) {
5552 up_write(&EXT4_I(inode)->i_data_sem);
5553 goto out_stop;
5554 }
5555 ext4_discard_preallocations(inode);
5556
5557 ret = ext4_ext_shift_extents(inode, handle, punch_stop,
5558 punch_stop - punch_start, SHIFT_LEFT);
5559 if (ret) {
5560 up_write(&EXT4_I(inode)->i_data_sem);
5561 goto out_stop;
5562 }
5563
5564 new_size = i_size_read(inode) - len;
5565 i_size_write(inode, new_size);
5566 EXT4_I(inode)->i_disksize = new_size;
5567
5568 up_write(&EXT4_I(inode)->i_data_sem);
5569 if (IS_SYNC(inode))
5570 ext4_handle_sync(handle);
5571 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
5572 ext4_mark_inode_dirty(handle, inode);
5573
5574 out_stop:
5575 ext4_journal_stop(handle);
5576 out_dio:
5577 ext4_inode_resume_unlocked_dio(inode);
5578 out_mutex:
5579 mutex_unlock(&inode->i_mutex);
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 */
5591 int 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 /*
5631 * Need to round down to align start offset to page size boundary
5632 * for page size > block size.
5633 */
5634 ioffset = round_down(offset, PAGE_SIZE);
5635
5636 /* Write out all dirty pages */
5637 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5638 LLONG_MAX);
5639 if (ret)
5640 return ret;
5641
5642 /* Take mutex lock */
5643 mutex_lock(&inode->i_mutex);
5644
5645 /* Currently just for extent based files */
5646 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5647 ret = -EOPNOTSUPP;
5648 goto out_mutex;
5649 }
5650
5651 /* Check for wrap through zero */
5652 if (inode->i_size + len > inode->i_sb->s_maxbytes) {
5653 ret = -EFBIG;
5654 goto out_mutex;
5655 }
5656
5657 /* Offset should be less than i_size */
5658 if (offset >= i_size_read(inode)) {
5659 ret = -EINVAL;
5660 goto out_mutex;
5661 }
5662
5663 truncate_pagecache(inode, ioffset);
5664
5665 /* Wait for existing dio to complete */
5666 ext4_inode_block_unlocked_dio(inode);
5667 inode_dio_wait(inode);
5668
5669 credits = ext4_writepage_trans_blocks(inode);
5670 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5671 if (IS_ERR(handle)) {
5672 ret = PTR_ERR(handle);
5673 goto out_dio;
5674 }
5675
5676 /* Expand file to avoid data loss if there is error while shifting */
5677 inode->i_size += len;
5678 EXT4_I(inode)->i_disksize += len;
5679 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
5680 ret = ext4_mark_inode_dirty(handle, inode);
5681 if (ret)
5682 goto out_stop;
5683
5684 down_write(&EXT4_I(inode)->i_data_sem);
5685 ext4_discard_preallocations(inode);
5686
5687 path = ext4_find_extent(inode, offset_lblk, NULL, 0);
5688 if (IS_ERR(path)) {
5689 up_write(&EXT4_I(inode)->i_data_sem);
5690 goto out_stop;
5691 }
5692
5693 depth = ext_depth(inode);
5694 extent = path[depth].p_ext;
5695 if (extent) {
5696 ee_start_lblk = le32_to_cpu(extent->ee_block);
5697 ee_len = ext4_ext_get_actual_len(extent);
5698
5699 /*
5700 * If offset_lblk is not the starting block of extent, split
5701 * the extent @offset_lblk
5702 */
5703 if ((offset_lblk > ee_start_lblk) &&
5704 (offset_lblk < (ee_start_lblk + ee_len))) {
5705 if (ext4_ext_is_unwritten(extent))
5706 split_flag = EXT4_EXT_MARK_UNWRIT1 |
5707 EXT4_EXT_MARK_UNWRIT2;
5708 ret = ext4_split_extent_at(handle, inode, &path,
5709 offset_lblk, split_flag,
5710 EXT4_EX_NOCACHE |
5711 EXT4_GET_BLOCKS_PRE_IO |
5712 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5713 }
5714
5715 ext4_ext_drop_refs(path);
5716 kfree(path);
5717 if (ret < 0) {
5718 up_write(&EXT4_I(inode)->i_data_sem);
5719 goto out_stop;
5720 }
5721 }
5722
5723 ret = ext4_es_remove_extent(inode, offset_lblk,
5724 EXT_MAX_BLOCKS - offset_lblk);
5725 if (ret) {
5726 up_write(&EXT4_I(inode)->i_data_sem);
5727 goto out_stop;
5728 }
5729
5730 /*
5731 * if offset_lblk lies in a hole which is at start of file, use
5732 * ee_start_lblk to shift extents
5733 */
5734 ret = ext4_ext_shift_extents(inode, handle,
5735 ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk,
5736 len_lblk, SHIFT_RIGHT);
5737
5738 up_write(&EXT4_I(inode)->i_data_sem);
5739 if (IS_SYNC(inode))
5740 ext4_handle_sync(handle);
5741
5742 out_stop:
5743 ext4_journal_stop(handle);
5744 out_dio:
5745 ext4_inode_resume_unlocked_dio(inode);
5746 out_mutex:
5747 mutex_unlock(&inode->i_mutex);
5748 return ret;
5749 }
5750
5751 /**
5752 * ext4_swap_extents - Swap extents between two inodes
5753 *
5754 * @inode1: First inode
5755 * @inode2: Second inode
5756 * @lblk1: Start block for first inode
5757 * @lblk2: Start block for second inode
5758 * @count: Number of blocks to swap
5759 * @mark_unwritten: Mark second inode's extents as unwritten after swap
5760 * @erp: Pointer to save error value
5761 *
5762 * This helper routine does exactly what is promise "swap extents". All other
5763 * stuff such as page-cache locking consistency, bh mapping consistency or
5764 * extent's data copying must be performed by caller.
5765 * Locking:
5766 * i_mutex is held for both inodes
5767 * i_data_sem is locked for write for both inodes
5768 * Assumptions:
5769 * All pages from requested range are locked for both inodes
5770 */
5771 int
5772 ext4_swap_extents(handle_t *handle, struct inode *inode1,
5773 struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
5774 ext4_lblk_t count, int unwritten, int *erp)
5775 {
5776 struct ext4_ext_path *path1 = NULL;
5777 struct ext4_ext_path *path2 = NULL;
5778 int replaced_count = 0;
5779
5780 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
5781 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
5782 BUG_ON(!mutex_is_locked(&inode1->i_mutex));
5783 BUG_ON(!mutex_is_locked(&inode2->i_mutex));
5784
5785 *erp = ext4_es_remove_extent(inode1, lblk1, count);
5786 if (unlikely(*erp))
5787 return 0;
5788 *erp = ext4_es_remove_extent(inode2, lblk2, count);
5789 if (unlikely(*erp))
5790 return 0;
5791
5792 while (count) {
5793 struct ext4_extent *ex1, *ex2, tmp_ex;
5794 ext4_lblk_t e1_blk, e2_blk;
5795 int e1_len, e2_len, len;
5796 int split = 0;
5797
5798 path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE);
5799 if (IS_ERR(path1)) {
5800 *erp = PTR_ERR(path1);
5801 path1 = NULL;
5802 finish:
5803 count = 0;
5804 goto repeat;
5805 }
5806 path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE);
5807 if (IS_ERR(path2)) {
5808 *erp = PTR_ERR(path2);
5809 path2 = NULL;
5810 goto finish;
5811 }
5812 ex1 = path1[path1->p_depth].p_ext;
5813 ex2 = path2[path2->p_depth].p_ext;
5814 /* Do we have somthing to swap ? */
5815 if (unlikely(!ex2 || !ex1))
5816 goto finish;
5817
5818 e1_blk = le32_to_cpu(ex1->ee_block);
5819 e2_blk = le32_to_cpu(ex2->ee_block);
5820 e1_len = ext4_ext_get_actual_len(ex1);
5821 e2_len = ext4_ext_get_actual_len(ex2);
5822
5823 /* Hole handling */
5824 if (!in_range(lblk1, e1_blk, e1_len) ||
5825 !in_range(lblk2, e2_blk, e2_len)) {
5826 ext4_lblk_t next1, next2;
5827
5828 /* if hole after extent, then go to next extent */
5829 next1 = ext4_ext_next_allocated_block(path1);
5830 next2 = ext4_ext_next_allocated_block(path2);
5831 /* If hole before extent, then shift to that extent */
5832 if (e1_blk > lblk1)
5833 next1 = e1_blk;
5834 if (e2_blk > lblk2)
5835 next2 = e1_blk;
5836 /* Do we have something to swap */
5837 if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
5838 goto finish;
5839 /* Move to the rightest boundary */
5840 len = next1 - lblk1;
5841 if (len < next2 - lblk2)
5842 len = next2 - lblk2;
5843 if (len > count)
5844 len = count;
5845 lblk1 += len;
5846 lblk2 += len;
5847 count -= len;
5848 goto repeat;
5849 }
5850
5851 /* Prepare left boundary */
5852 if (e1_blk < lblk1) {
5853 split = 1;
5854 *erp = ext4_force_split_extent_at(handle, inode1,
5855 &path1, lblk1, 0);
5856 if (unlikely(*erp))
5857 goto finish;
5858 }
5859 if (e2_blk < lblk2) {
5860 split = 1;
5861 *erp = ext4_force_split_extent_at(handle, inode2,
5862 &path2, lblk2, 0);
5863 if (unlikely(*erp))
5864 goto finish;
5865 }
5866 /* ext4_split_extent_at() may result in leaf extent split,
5867 * path must to be revalidated. */
5868 if (split)
5869 goto repeat;
5870
5871 /* Prepare right boundary */
5872 len = count;
5873 if (len > e1_blk + e1_len - lblk1)
5874 len = e1_blk + e1_len - lblk1;
5875 if (len > e2_blk + e2_len - lblk2)
5876 len = e2_blk + e2_len - lblk2;
5877
5878 if (len != e1_len) {
5879 split = 1;
5880 *erp = ext4_force_split_extent_at(handle, inode1,
5881 &path1, lblk1 + len, 0);
5882 if (unlikely(*erp))
5883 goto finish;
5884 }
5885 if (len != e2_len) {
5886 split = 1;
5887 *erp = ext4_force_split_extent_at(handle, inode2,
5888 &path2, lblk2 + len, 0);
5889 if (*erp)
5890 goto finish;
5891 }
5892 /* ext4_split_extent_at() may result in leaf extent split,
5893 * path must to be revalidated. */
5894 if (split)
5895 goto repeat;
5896
5897 BUG_ON(e2_len != e1_len);
5898 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
5899 if (unlikely(*erp))
5900 goto finish;
5901 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
5902 if (unlikely(*erp))
5903 goto finish;
5904
5905 /* Both extents are fully inside boundaries. Swap it now */
5906 tmp_ex = *ex1;
5907 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
5908 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
5909 ex1->ee_len = cpu_to_le16(e2_len);
5910 ex2->ee_len = cpu_to_le16(e1_len);
5911 if (unwritten)
5912 ext4_ext_mark_unwritten(ex2);
5913 if (ext4_ext_is_unwritten(&tmp_ex))
5914 ext4_ext_mark_unwritten(ex1);
5915
5916 ext4_ext_try_to_merge(handle, inode2, path2, ex2);
5917 ext4_ext_try_to_merge(handle, inode1, path1, ex1);
5918 *erp = ext4_ext_dirty(handle, inode2, path2 +
5919 path2->p_depth);
5920 if (unlikely(*erp))
5921 goto finish;
5922 *erp = ext4_ext_dirty(handle, inode1, path1 +
5923 path1->p_depth);
5924 /*
5925 * Looks scarry ah..? second inode already points to new blocks,
5926 * and it was successfully dirtied. But luckily error may happen
5927 * only due to journal error, so full transaction will be
5928 * aborted anyway.
5929 */
5930 if (unlikely(*erp))
5931 goto finish;
5932 lblk1 += len;
5933 lblk2 += len;
5934 replaced_count += len;
5935 count -= len;
5936
5937 repeat:
5938 ext4_ext_drop_refs(path1);
5939 kfree(path1);
5940 ext4_ext_drop_refs(path2);
5941 kfree(path2);
5942 path1 = path2 = NULL;
5943 }
5944 return replaced_count;
5945 }
Linux with added FPC-III support