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ARM: mvebu: use new bindings for existing crypto devices
[linux/fpc-iii.git] / fs / ext4 / extents.c
blob2553aa8b608d84d1673190ea634c5e84c86d9f0b
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;
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 goto corrupted;
477 }
478 return 0;
479
480 corrupted:
481 ext4_error_inode(inode, function, line, 0,
482 "pblk %llu bad header/extent: %s - magic %x, "
483 "entries %u, max %u(%u), depth %u(%u)",
484 (unsigned long long) pblk, error_msg,
485 le16_to_cpu(eh->eh_magic),
486 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max),
487 max, le16_to_cpu(eh->eh_depth), depth);
488 return -EIO;
489 }
490
491 #define ext4_ext_check(inode, eh, depth, pblk) \
492 __ext4_ext_check(__func__, __LINE__, (inode), (eh), (depth), (pblk))
493
494 int ext4_ext_check_inode(struct inode *inode)
495 {
496 return ext4_ext_check(inode, ext_inode_hdr(inode), ext_depth(inode), 0);
497 }
498
499 static struct buffer_head *
500 __read_extent_tree_block(const char *function, unsigned int line,
501 struct inode *inode, ext4_fsblk_t pblk, int depth,
502 int flags)
503 {
504 struct buffer_head *bh;
505 int err;
506
507 bh = sb_getblk_gfp(inode->i_sb, pblk, __GFP_MOVABLE | GFP_NOFS);
508 if (unlikely(!bh))
509 return ERR_PTR(-ENOMEM);
510
511 if (!bh_uptodate_or_lock(bh)) {
512 trace_ext4_ext_load_extent(inode, pblk, _RET_IP_);
513 err = bh_submit_read(bh);
514 if (err < 0)
515 goto errout;
516 }
517 if (buffer_verified(bh) && !(flags & EXT4_EX_FORCE_CACHE))
518 return bh;
519 err = __ext4_ext_check(function, line, inode,
520 ext_block_hdr(bh), depth, pblk);
521 if (err)
522 goto errout;
523 set_buffer_verified(bh);
524 /*
525 * If this is a leaf block, cache all of its entries
526 */
527 if (!(flags & EXT4_EX_NOCACHE) && depth == 0) {
528 struct ext4_extent_header *eh = ext_block_hdr(bh);
529 struct ext4_extent *ex = EXT_FIRST_EXTENT(eh);
530 ext4_lblk_t prev = 0;
531 int i;
532
533 for (i = le16_to_cpu(eh->eh_entries); i > 0; i--, ex++) {
534 unsigned int status = EXTENT_STATUS_WRITTEN;
535 ext4_lblk_t lblk = le32_to_cpu(ex->ee_block);
536 int len = ext4_ext_get_actual_len(ex);
537
538 if (prev && (prev != lblk))
539 ext4_es_cache_extent(inode, prev,
540 lblk - prev, ~0,
541 EXTENT_STATUS_HOLE);
542
543 if (ext4_ext_is_unwritten(ex))
544 status = EXTENT_STATUS_UNWRITTEN;
545 ext4_es_cache_extent(inode, lblk, len,
546 ext4_ext_pblock(ex), status);
547 prev = lblk + len;
548 }
549 }
550 return bh;
551 errout:
552 put_bh(bh);
553 return ERR_PTR(err);
554
555 }
556
557 #define read_extent_tree_block(inode, pblk, depth, flags) \
558 __read_extent_tree_block(__func__, __LINE__, (inode), (pblk), \
559 (depth), (flags))
560
561 /*
562 * This function is called to cache a file's extent information in the
563 * extent status tree
564 */
565 int ext4_ext_precache(struct inode *inode)
566 {
567 struct ext4_inode_info *ei = EXT4_I(inode);
568 struct ext4_ext_path *path = NULL;
569 struct buffer_head *bh;
570 int i = 0, depth, ret = 0;
571
572 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
573 return 0; /* not an extent-mapped inode */
574
575 down_read(&ei->i_data_sem);
576 depth = ext_depth(inode);
577
578 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
579 GFP_NOFS);
580 if (path == NULL) {
581 up_read(&ei->i_data_sem);
582 return -ENOMEM;
583 }
584
585 /* Don't cache anything if there are no external extent blocks */
586 if (depth == 0)
587 goto out;
588 path[0].p_hdr = ext_inode_hdr(inode);
589 ret = ext4_ext_check(inode, path[0].p_hdr, depth, 0);
590 if (ret)
591 goto out;
592 path[0].p_idx = EXT_FIRST_INDEX(path[0].p_hdr);
593 while (i >= 0) {
594 /*
595 * If this is a leaf block or we've reached the end of
596 * the index block, go up
597 */
598 if ((i == depth) ||
599 path[i].p_idx > EXT_LAST_INDEX(path[i].p_hdr)) {
600 brelse(path[i].p_bh);
601 path[i].p_bh = NULL;
602 i--;
603 continue;
604 }
605 bh = read_extent_tree_block(inode,
606 ext4_idx_pblock(path[i].p_idx++),
607 depth - i - 1,
608 EXT4_EX_FORCE_CACHE);
609 if (IS_ERR(bh)) {
610 ret = PTR_ERR(bh);
611 break;
612 }
613 i++;
614 path[i].p_bh = bh;
615 path[i].p_hdr = ext_block_hdr(bh);
616 path[i].p_idx = EXT_FIRST_INDEX(path[i].p_hdr);
617 }
618 ext4_set_inode_state(inode, EXT4_STATE_EXT_PRECACHED);
619 out:
620 up_read(&ei->i_data_sem);
621 ext4_ext_drop_refs(path);
622 kfree(path);
623 return ret;
624 }
625
626 #ifdef EXT_DEBUG
627 static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path)
628 {
629 int k, l = path->p_depth;
630
631 ext_debug("path:");
632 for (k = 0; k <= l; k++, path++) {
633 if (path->p_idx) {
634 ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block),
635 ext4_idx_pblock(path->p_idx));
636 } else if (path->p_ext) {
637 ext_debug(" %d:[%d]%d:%llu ",
638 le32_to_cpu(path->p_ext->ee_block),
639 ext4_ext_is_unwritten(path->p_ext),
640 ext4_ext_get_actual_len(path->p_ext),
641 ext4_ext_pblock(path->p_ext));
642 } else
643 ext_debug(" []");
644 }
645 ext_debug("\n");
646 }
647
648 static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path)
649 {
650 int depth = ext_depth(inode);
651 struct ext4_extent_header *eh;
652 struct ext4_extent *ex;
653 int i;
654
655 if (!path)
656 return;
657
658 eh = path[depth].p_hdr;
659 ex = EXT_FIRST_EXTENT(eh);
660
661 ext_debug("Displaying leaf extents for inode %lu\n", inode->i_ino);
662
663 for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) {
664 ext_debug("%d:[%d]%d:%llu ", le32_to_cpu(ex->ee_block),
665 ext4_ext_is_unwritten(ex),
666 ext4_ext_get_actual_len(ex), ext4_ext_pblock(ex));
667 }
668 ext_debug("\n");
669 }
670
671 static void ext4_ext_show_move(struct inode *inode, struct ext4_ext_path *path,
672 ext4_fsblk_t newblock, int level)
673 {
674 int depth = ext_depth(inode);
675 struct ext4_extent *ex;
676
677 if (depth != level) {
678 struct ext4_extent_idx *idx;
679 idx = path[level].p_idx;
680 while (idx <= EXT_MAX_INDEX(path[level].p_hdr)) {
681 ext_debug("%d: move %d:%llu in new index %llu\n", level,
682 le32_to_cpu(idx->ei_block),
683 ext4_idx_pblock(idx),
684 newblock);
685 idx++;
686 }
687
688 return;
689 }
690
691 ex = path[depth].p_ext;
692 while (ex <= EXT_MAX_EXTENT(path[depth].p_hdr)) {
693 ext_debug("move %d:%llu:[%d]%d in new leaf %llu\n",
694 le32_to_cpu(ex->ee_block),
695 ext4_ext_pblock(ex),
696 ext4_ext_is_unwritten(ex),
697 ext4_ext_get_actual_len(ex),
698 newblock);
699 ex++;
700 }
701 }
702
703 #else
704 #define ext4_ext_show_path(inode, path)
705 #define ext4_ext_show_leaf(inode, path)
706 #define ext4_ext_show_move(inode, path, newblock, level)
707 #endif
708
709 void ext4_ext_drop_refs(struct ext4_ext_path *path)
710 {
711 int depth, i;
712
713 if (!path)
714 return;
715 depth = path->p_depth;
716 for (i = 0; i <= depth; i++, path++)
717 if (path->p_bh) {
718 brelse(path->p_bh);
719 path->p_bh = NULL;
720 }
721 }
722
723 /*
724 * ext4_ext_binsearch_idx:
725 * binary search for the closest index of the given block
726 * the header must be checked before calling this
727 */
728 static void
729 ext4_ext_binsearch_idx(struct inode *inode,
730 struct ext4_ext_path *path, ext4_lblk_t block)
731 {
732 struct ext4_extent_header *eh = path->p_hdr;
733 struct ext4_extent_idx *r, *l, *m;
734
735
736 ext_debug("binsearch for %u(idx): ", block);
737
738 l = EXT_FIRST_INDEX(eh) + 1;
739 r = EXT_LAST_INDEX(eh);
740 while (l <= r) {
741 m = l + (r - l) / 2;
742 if (block < le32_to_cpu(m->ei_block))
743 r = m - 1;
744 else
745 l = m + 1;
746 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ei_block),
747 m, le32_to_cpu(m->ei_block),
748 r, le32_to_cpu(r->ei_block));
749 }
750
751 path->p_idx = l - 1;
752 ext_debug(" -> %u->%lld ", le32_to_cpu(path->p_idx->ei_block),
753 ext4_idx_pblock(path->p_idx));
754
755 #ifdef CHECK_BINSEARCH
756 {
757 struct ext4_extent_idx *chix, *ix;
758 int k;
759
760 chix = ix = EXT_FIRST_INDEX(eh);
761 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) {
762 if (k != 0 &&
763 le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) {
764 printk(KERN_DEBUG "k=%d, ix=0x%p, "
765 "first=0x%p\n", k,
766 ix, EXT_FIRST_INDEX(eh));
767 printk(KERN_DEBUG "%u <= %u\n",
768 le32_to_cpu(ix->ei_block),
769 le32_to_cpu(ix[-1].ei_block));
770 }
771 BUG_ON(k && le32_to_cpu(ix->ei_block)
772 <= le32_to_cpu(ix[-1].ei_block));
773 if (block < le32_to_cpu(ix->ei_block))
774 break;
775 chix = ix;
776 }
777 BUG_ON(chix != path->p_idx);
778 }
779 #endif
780
781 }
782
783 /*
784 * ext4_ext_binsearch:
785 * binary search for closest extent of the given block
786 * the header must be checked before calling this
787 */
788 static void
789 ext4_ext_binsearch(struct inode *inode,
790 struct ext4_ext_path *path, ext4_lblk_t block)
791 {
792 struct ext4_extent_header *eh = path->p_hdr;
793 struct ext4_extent *r, *l, *m;
794
795 if (eh->eh_entries == 0) {
796 /*
797 * this leaf is empty:
798 * we get such a leaf in split/add case
799 */
800 return;
801 }
802
803 ext_debug("binsearch for %u: ", block);
804
805 l = EXT_FIRST_EXTENT(eh) + 1;
806 r = EXT_LAST_EXTENT(eh);
807
808 while (l <= r) {
809 m = l + (r - l) / 2;
810 if (block < le32_to_cpu(m->ee_block))
811 r = m - 1;
812 else
813 l = m + 1;
814 ext_debug("%p(%u):%p(%u):%p(%u) ", l, le32_to_cpu(l->ee_block),
815 m, le32_to_cpu(m->ee_block),
816 r, le32_to_cpu(r->ee_block));
817 }
818
819 path->p_ext = l - 1;
820 ext_debug(" -> %d:%llu:[%d]%d ",
821 le32_to_cpu(path->p_ext->ee_block),
822 ext4_ext_pblock(path->p_ext),
823 ext4_ext_is_unwritten(path->p_ext),
824 ext4_ext_get_actual_len(path->p_ext));
825
826 #ifdef CHECK_BINSEARCH
827 {
828 struct ext4_extent *chex, *ex;
829 int k;
830
831 chex = ex = EXT_FIRST_EXTENT(eh);
832 for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) {
833 BUG_ON(k && le32_to_cpu(ex->ee_block)
834 <= le32_to_cpu(ex[-1].ee_block));
835 if (block < le32_to_cpu(ex->ee_block))
836 break;
837 chex = ex;
838 }
839 BUG_ON(chex != path->p_ext);
840 }
841 #endif
842
843 }
844
845 int ext4_ext_tree_init(handle_t *handle, struct inode *inode)
846 {
847 struct ext4_extent_header *eh;
848
849 eh = ext_inode_hdr(inode);
850 eh->eh_depth = 0;
851 eh->eh_entries = 0;
852 eh->eh_magic = EXT4_EXT_MAGIC;
853 eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode, 0));
854 ext4_mark_inode_dirty(handle, inode);
855 return 0;
856 }
857
858 struct ext4_ext_path *
859 ext4_find_extent(struct inode *inode, ext4_lblk_t block,
860 struct ext4_ext_path **orig_path, int flags)
861 {
862 struct ext4_extent_header *eh;
863 struct buffer_head *bh;
864 struct ext4_ext_path *path = orig_path ? *orig_path : NULL;
865 short int depth, i, ppos = 0;
866 int ret;
867
868 eh = ext_inode_hdr(inode);
869 depth = ext_depth(inode);
870
871 if (path) {
872 ext4_ext_drop_refs(path);
873 if (depth > path[0].p_maxdepth) {
874 kfree(path);
875 *orig_path = path = NULL;
876 }
877 }
878 if (!path) {
879 /* account possible depth increase */
880 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 2),
881 GFP_NOFS);
882 if (unlikely(!path))
883 return ERR_PTR(-ENOMEM);
884 path[0].p_maxdepth = depth + 1;
885 }
886 path[0].p_hdr = eh;
887 path[0].p_bh = NULL;
888
889 i = depth;
890 /* walk through the tree */
891 while (i) {
892 ext_debug("depth %d: num %d, max %d\n",
893 ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
894
895 ext4_ext_binsearch_idx(inode, path + ppos, block);
896 path[ppos].p_block = ext4_idx_pblock(path[ppos].p_idx);
897 path[ppos].p_depth = i;
898 path[ppos].p_ext = NULL;
899
900 bh = read_extent_tree_block(inode, path[ppos].p_block, --i,
901 flags);
902 if (unlikely(IS_ERR(bh))) {
903 ret = PTR_ERR(bh);
904 goto err;
905 }
906
907 eh = ext_block_hdr(bh);
908 ppos++;
909 if (unlikely(ppos > depth)) {
910 put_bh(bh);
911 EXT4_ERROR_INODE(inode,
912 "ppos %d > depth %d", ppos, depth);
913 ret = -EIO;
914 goto err;
915 }
916 path[ppos].p_bh = bh;
917 path[ppos].p_hdr = eh;
918 }
919
920 path[ppos].p_depth = i;
921 path[ppos].p_ext = NULL;
922 path[ppos].p_idx = NULL;
923
924 /* find extent */
925 ext4_ext_binsearch(inode, path + ppos, block);
926 /* if not an empty leaf */
927 if (path[ppos].p_ext)
928 path[ppos].p_block = ext4_ext_pblock(path[ppos].p_ext);
929
930 ext4_ext_show_path(inode, path);
931
932 return path;
933
934 err:
935 ext4_ext_drop_refs(path);
936 kfree(path);
937 if (orig_path)
938 *orig_path = NULL;
939 return ERR_PTR(ret);
940 }
941
942 /*
943 * ext4_ext_insert_index:
944 * insert new index [@logical;@ptr] into the block at @curp;
945 * check where to insert: before @curp or after @curp
946 */
947 static int ext4_ext_insert_index(handle_t *handle, struct inode *inode,
948 struct ext4_ext_path *curp,
949 int logical, ext4_fsblk_t ptr)
950 {
951 struct ext4_extent_idx *ix;
952 int len, err;
953
954 err = ext4_ext_get_access(handle, inode, curp);
955 if (err)
956 return err;
957
958 if (unlikely(logical == le32_to_cpu(curp->p_idx->ei_block))) {
959 EXT4_ERROR_INODE(inode,
960 "logical %d == ei_block %d!",
961 logical, le32_to_cpu(curp->p_idx->ei_block));
962 return -EIO;
963 }
964
965 if (unlikely(le16_to_cpu(curp->p_hdr->eh_entries)
966 >= le16_to_cpu(curp->p_hdr->eh_max))) {
967 EXT4_ERROR_INODE(inode,
968 "eh_entries %d >= eh_max %d!",
969 le16_to_cpu(curp->p_hdr->eh_entries),
970 le16_to_cpu(curp->p_hdr->eh_max));
971 return -EIO;
972 }
973
974 if (logical > le32_to_cpu(curp->p_idx->ei_block)) {
975 /* insert after */
976 ext_debug("insert new index %d after: %llu\n", logical, ptr);
977 ix = curp->p_idx + 1;
978 } else {
979 /* insert before */
980 ext_debug("insert new index %d before: %llu\n", logical, ptr);
981 ix = curp->p_idx;
982 }
983
984 len = EXT_LAST_INDEX(curp->p_hdr) - ix + 1;
985 BUG_ON(len < 0);
986 if (len > 0) {
987 ext_debug("insert new index %d: "
988 "move %d indices from 0x%p to 0x%p\n",
989 logical, len, ix, ix + 1);
990 memmove(ix + 1, ix, len * sizeof(struct ext4_extent_idx));
991 }
992
993 if (unlikely(ix > EXT_MAX_INDEX(curp->p_hdr))) {
994 EXT4_ERROR_INODE(inode, "ix > EXT_MAX_INDEX!");
995 return -EIO;
996 }
997
998 ix->ei_block = cpu_to_le32(logical);
999 ext4_idx_store_pblock(ix, ptr);
1000 le16_add_cpu(&curp->p_hdr->eh_entries, 1);
1001
1002 if (unlikely(ix > EXT_LAST_INDEX(curp->p_hdr))) {
1003 EXT4_ERROR_INODE(inode, "ix > EXT_LAST_INDEX!");
1004 return -EIO;
1005 }
1006
1007 err = ext4_ext_dirty(handle, inode, curp);
1008 ext4_std_error(inode->i_sb, err);
1009
1010 return err;
1011 }
1012
1013 /*
1014 * ext4_ext_split:
1015 * inserts new subtree into the path, using free index entry
1016 * at depth @at:
1017 * - allocates all needed blocks (new leaf and all intermediate index blocks)
1018 * - makes decision where to split
1019 * - moves remaining extents and index entries (right to the split point)
1020 * into the newly allocated blocks
1021 * - initializes subtree
1022 */
1023 static int ext4_ext_split(handle_t *handle, struct inode *inode,
1024 unsigned int flags,
1025 struct ext4_ext_path *path,
1026 struct ext4_extent *newext, int at)
1027 {
1028 struct buffer_head *bh = NULL;
1029 int depth = ext_depth(inode);
1030 struct ext4_extent_header *neh;
1031 struct ext4_extent_idx *fidx;
1032 int i = at, k, m, a;
1033 ext4_fsblk_t newblock, oldblock;
1034 __le32 border;
1035 ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */
1036 int err = 0;
1037
1038 /* make decision: where to split? */
1039 /* FIXME: now decision is simplest: at current extent */
1040
1041 /* if current leaf will be split, then we should use
1042 * border from split point */
1043 if (unlikely(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr))) {
1044 EXT4_ERROR_INODE(inode, "p_ext > EXT_MAX_EXTENT!");
1045 return -EIO;
1046 }
1047 if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) {
1048 border = path[depth].p_ext[1].ee_block;
1049 ext_debug("leaf will be split."
1050 " next leaf starts at %d\n",
1051 le32_to_cpu(border));
1052 } else {
1053 border = newext->ee_block;
1054 ext_debug("leaf will be added."
1055 " next leaf starts at %d\n",
1056 le32_to_cpu(border));
1057 }
1058
1059 /*
1060 * If error occurs, then we break processing
1061 * and mark filesystem read-only. index won't
1062 * be inserted and tree will be in consistent
1063 * state. Next mount will repair buffers too.
1064 */
1065
1066 /*
1067 * Get array to track all allocated blocks.
1068 * We need this to handle errors and free blocks
1069 * upon them.
1070 */
1071 ablocks = kzalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS);
1072 if (!ablocks)
1073 return -ENOMEM;
1074
1075 /* allocate all needed blocks */
1076 ext_debug("allocate %d blocks for indexes/leaf\n", depth - at);
1077 for (a = 0; a < depth - at; a++) {
1078 newblock = ext4_ext_new_meta_block(handle, inode, path,
1079 newext, &err, flags);
1080 if (newblock == 0)
1081 goto cleanup;
1082 ablocks[a] = newblock;
1083 }
1084
1085 /* initialize new leaf */
1086 newblock = ablocks[--a];
1087 if (unlikely(newblock == 0)) {
1088 EXT4_ERROR_INODE(inode, "newblock == 0!");
1089 err = -EIO;
1090 goto cleanup;
1091 }
1092 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1093 if (unlikely(!bh)) {
1094 err = -ENOMEM;
1095 goto cleanup;
1096 }
1097 lock_buffer(bh);
1098
1099 err = ext4_journal_get_create_access(handle, bh);
1100 if (err)
1101 goto cleanup;
1102
1103 neh = ext_block_hdr(bh);
1104 neh->eh_entries = 0;
1105 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1106 neh->eh_magic = EXT4_EXT_MAGIC;
1107 neh->eh_depth = 0;
1108
1109 /* move remainder of path[depth] to the new leaf */
1110 if (unlikely(path[depth].p_hdr->eh_entries !=
1111 path[depth].p_hdr->eh_max)) {
1112 EXT4_ERROR_INODE(inode, "eh_entries %d != eh_max %d!",
1113 path[depth].p_hdr->eh_entries,
1114 path[depth].p_hdr->eh_max);
1115 err = -EIO;
1116 goto cleanup;
1117 }
1118 /* start copy from next extent */
1119 m = EXT_MAX_EXTENT(path[depth].p_hdr) - path[depth].p_ext++;
1120 ext4_ext_show_move(inode, path, newblock, depth);
1121 if (m) {
1122 struct ext4_extent *ex;
1123 ex = EXT_FIRST_EXTENT(neh);
1124 memmove(ex, path[depth].p_ext, sizeof(struct ext4_extent) * m);
1125 le16_add_cpu(&neh->eh_entries, m);
1126 }
1127
1128 ext4_extent_block_csum_set(inode, neh);
1129 set_buffer_uptodate(bh);
1130 unlock_buffer(bh);
1131
1132 err = ext4_handle_dirty_metadata(handle, inode, bh);
1133 if (err)
1134 goto cleanup;
1135 brelse(bh);
1136 bh = NULL;
1137
1138 /* correct old leaf */
1139 if (m) {
1140 err = ext4_ext_get_access(handle, inode, path + depth);
1141 if (err)
1142 goto cleanup;
1143 le16_add_cpu(&path[depth].p_hdr->eh_entries, -m);
1144 err = ext4_ext_dirty(handle, inode, path + depth);
1145 if (err)
1146 goto cleanup;
1147
1148 }
1149
1150 /* create intermediate indexes */
1151 k = depth - at - 1;
1152 if (unlikely(k < 0)) {
1153 EXT4_ERROR_INODE(inode, "k %d < 0!", k);
1154 err = -EIO;
1155 goto cleanup;
1156 }
1157 if (k)
1158 ext_debug("create %d intermediate indices\n", k);
1159 /* insert new index into current index block */
1160 /* current depth stored in i var */
1161 i = depth - 1;
1162 while (k--) {
1163 oldblock = newblock;
1164 newblock = ablocks[--a];
1165 bh = sb_getblk(inode->i_sb, newblock);
1166 if (unlikely(!bh)) {
1167 err = -ENOMEM;
1168 goto cleanup;
1169 }
1170 lock_buffer(bh);
1171
1172 err = ext4_journal_get_create_access(handle, bh);
1173 if (err)
1174 goto cleanup;
1175
1176 neh = ext_block_hdr(bh);
1177 neh->eh_entries = cpu_to_le16(1);
1178 neh->eh_magic = EXT4_EXT_MAGIC;
1179 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1180 neh->eh_depth = cpu_to_le16(depth - i);
1181 fidx = EXT_FIRST_INDEX(neh);
1182 fidx->ei_block = border;
1183 ext4_idx_store_pblock(fidx, oldblock);
1184
1185 ext_debug("int.index at %d (block %llu): %u -> %llu\n",
1186 i, newblock, le32_to_cpu(border), oldblock);
1187
1188 /* move remainder of path[i] to the new index block */
1189 if (unlikely(EXT_MAX_INDEX(path[i].p_hdr) !=
1190 EXT_LAST_INDEX(path[i].p_hdr))) {
1191 EXT4_ERROR_INODE(inode,
1192 "EXT_MAX_INDEX != EXT_LAST_INDEX ee_block %d!",
1193 le32_to_cpu(path[i].p_ext->ee_block));
1194 err = -EIO;
1195 goto cleanup;
1196 }
1197 /* start copy indexes */
1198 m = EXT_MAX_INDEX(path[i].p_hdr) - path[i].p_idx++;
1199 ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx,
1200 EXT_MAX_INDEX(path[i].p_hdr));
1201 ext4_ext_show_move(inode, path, newblock, i);
1202 if (m) {
1203 memmove(++fidx, path[i].p_idx,
1204 sizeof(struct ext4_extent_idx) * m);
1205 le16_add_cpu(&neh->eh_entries, m);
1206 }
1207 ext4_extent_block_csum_set(inode, neh);
1208 set_buffer_uptodate(bh);
1209 unlock_buffer(bh);
1210
1211 err = ext4_handle_dirty_metadata(handle, inode, bh);
1212 if (err)
1213 goto cleanup;
1214 brelse(bh);
1215 bh = NULL;
1216
1217 /* correct old index */
1218 if (m) {
1219 err = ext4_ext_get_access(handle, inode, path + i);
1220 if (err)
1221 goto cleanup;
1222 le16_add_cpu(&path[i].p_hdr->eh_entries, -m);
1223 err = ext4_ext_dirty(handle, inode, path + i);
1224 if (err)
1225 goto cleanup;
1226 }
1227
1228 i--;
1229 }
1230
1231 /* insert new index */
1232 err = ext4_ext_insert_index(handle, inode, path + at,
1233 le32_to_cpu(border), newblock);
1234
1235 cleanup:
1236 if (bh) {
1237 if (buffer_locked(bh))
1238 unlock_buffer(bh);
1239 brelse(bh);
1240 }
1241
1242 if (err) {
1243 /* free all allocated blocks in error case */
1244 for (i = 0; i < depth; i++) {
1245 if (!ablocks[i])
1246 continue;
1247 ext4_free_blocks(handle, inode, NULL, ablocks[i], 1,
1248 EXT4_FREE_BLOCKS_METADATA);
1249 }
1250 }
1251 kfree(ablocks);
1252
1253 return err;
1254 }
1255
1256 /*
1257 * ext4_ext_grow_indepth:
1258 * implements tree growing procedure:
1259 * - allocates new block
1260 * - moves top-level data (index block or leaf) into the new block
1261 * - initializes new top-level, creating index that points to the
1262 * just created block
1263 */
1264 static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode,
1265 unsigned int flags)
1266 {
1267 struct ext4_extent_header *neh;
1268 struct buffer_head *bh;
1269 ext4_fsblk_t newblock, goal = 0;
1270 struct ext4_super_block *es = EXT4_SB(inode->i_sb)->s_es;
1271 int err = 0;
1272
1273 /* Try to prepend new index to old one */
1274 if (ext_depth(inode))
1275 goal = ext4_idx_pblock(EXT_FIRST_INDEX(ext_inode_hdr(inode)));
1276 if (goal > le32_to_cpu(es->s_first_data_block)) {
1277 flags |= EXT4_MB_HINT_TRY_GOAL;
1278 goal--;
1279 } else
1280 goal = ext4_inode_to_goal_block(inode);
1281 newblock = ext4_new_meta_blocks(handle, inode, goal, flags,
1282 NULL, &err);
1283 if (newblock == 0)
1284 return err;
1285
1286 bh = sb_getblk_gfp(inode->i_sb, newblock, __GFP_MOVABLE | GFP_NOFS);
1287 if (unlikely(!bh))
1288 return -ENOMEM;
1289 lock_buffer(bh);
1290
1291 err = ext4_journal_get_create_access(handle, bh);
1292 if (err) {
1293 unlock_buffer(bh);
1294 goto out;
1295 }
1296
1297 /* move top-level index/leaf into new block */
1298 memmove(bh->b_data, EXT4_I(inode)->i_data,
1299 sizeof(EXT4_I(inode)->i_data));
1300
1301 /* set size of new block */
1302 neh = ext_block_hdr(bh);
1303 /* old root could have indexes or leaves
1304 * so calculate e_max right way */
1305 if (ext_depth(inode))
1306 neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode, 0));
1307 else
1308 neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode, 0));
1309 neh->eh_magic = EXT4_EXT_MAGIC;
1310 ext4_extent_block_csum_set(inode, neh);
1311 set_buffer_uptodate(bh);
1312 unlock_buffer(bh);
1313
1314 err = ext4_handle_dirty_metadata(handle, inode, bh);
1315 if (err)
1316 goto out;
1317
1318 /* Update top-level index: num,max,pointer */
1319 neh = ext_inode_hdr(inode);
1320 neh->eh_entries = cpu_to_le16(1);
1321 ext4_idx_store_pblock(EXT_FIRST_INDEX(neh), newblock);
1322 if (neh->eh_depth == 0) {
1323 /* Root extent block becomes index block */
1324 neh->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode, 0));
1325 EXT_FIRST_INDEX(neh)->ei_block =
1326 EXT_FIRST_EXTENT(neh)->ee_block;
1327 }
1328 ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n",
1329 le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max),
1330 le32_to_cpu(EXT_FIRST_INDEX(neh)->ei_block),
1331 ext4_idx_pblock(EXT_FIRST_INDEX(neh)));
1332
1333 le16_add_cpu(&neh->eh_depth, 1);
1334 ext4_mark_inode_dirty(handle, inode);
1335 out:
1336 brelse(bh);
1337
1338 return err;
1339 }
1340
1341 /*
1342 * ext4_ext_create_new_leaf:
1343 * finds empty index and adds new leaf.
1344 * if no free index is found, then it requests in-depth growing.
1345 */
1346 static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode,
1347 unsigned int mb_flags,
1348 unsigned int gb_flags,
1349 struct ext4_ext_path **ppath,
1350 struct ext4_extent *newext)
1351 {
1352 struct ext4_ext_path *path = *ppath;
1353 struct ext4_ext_path *curp;
1354 int depth, i, err = 0;
1355
1356 repeat:
1357 i = depth = ext_depth(inode);
1358
1359 /* walk up to the tree and look for free index entry */
1360 curp = path + depth;
1361 while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) {
1362 i--;
1363 curp--;
1364 }
1365
1366 /* we use already allocated block for index block,
1367 * so subsequent data blocks should be contiguous */
1368 if (EXT_HAS_FREE_INDEX(curp)) {
1369 /* if we found index with free entry, then use that
1370 * entry: create all needed subtree and add new leaf */
1371 err = ext4_ext_split(handle, inode, mb_flags, path, newext, i);
1372 if (err)
1373 goto out;
1374
1375 /* refill path */
1376 path = ext4_find_extent(inode,
1377 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1378 ppath, gb_flags);
1379 if (IS_ERR(path))
1380 err = PTR_ERR(path);
1381 } else {
1382 /* tree is full, time to grow in depth */
1383 err = ext4_ext_grow_indepth(handle, inode, mb_flags);
1384 if (err)
1385 goto out;
1386
1387 /* refill path */
1388 path = ext4_find_extent(inode,
1389 (ext4_lblk_t)le32_to_cpu(newext->ee_block),
1390 ppath, gb_flags);
1391 if (IS_ERR(path)) {
1392 err = PTR_ERR(path);
1393 goto out;
1394 }
1395
1396 /*
1397 * only first (depth 0 -> 1) produces free space;
1398 * in all other cases we have to split the grown tree
1399 */
1400 depth = ext_depth(inode);
1401 if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) {
1402 /* now we need to split */
1403 goto repeat;
1404 }
1405 }
1406
1407 out:
1408 return err;
1409 }
1410
1411 /*
1412 * search the closest allocated block to the left for *logical
1413 * and returns it at @logical + it's physical address at @phys
1414 * if *logical is the smallest allocated block, the function
1415 * returns 0 at @phys
1416 * return value contains 0 (success) or error code
1417 */
1418 static int ext4_ext_search_left(struct inode *inode,
1419 struct ext4_ext_path *path,
1420 ext4_lblk_t *logical, ext4_fsblk_t *phys)
1421 {
1422 struct ext4_extent_idx *ix;
1423 struct ext4_extent *ex;
1424 int depth, ee_len;
1425
1426 if (unlikely(path == NULL)) {
1427 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1428 return -EIO;
1429 }
1430 depth = path->p_depth;
1431 *phys = 0;
1432
1433 if (depth == 0 && path->p_ext == NULL)
1434 return 0;
1435
1436 /* usually extent in the path covers blocks smaller
1437 * then *logical, but it can be that extent is the
1438 * first one in the file */
1439
1440 ex = path[depth].p_ext;
1441 ee_len = ext4_ext_get_actual_len(ex);
1442 if (*logical < le32_to_cpu(ex->ee_block)) {
1443 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1444 EXT4_ERROR_INODE(inode,
1445 "EXT_FIRST_EXTENT != ex *logical %d ee_block %d!",
1446 *logical, le32_to_cpu(ex->ee_block));
1447 return -EIO;
1448 }
1449 while (--depth >= 0) {
1450 ix = path[depth].p_idx;
1451 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1452 EXT4_ERROR_INODE(inode,
1453 "ix (%d) != EXT_FIRST_INDEX (%d) (depth %d)!",
1454 ix != NULL ? le32_to_cpu(ix->ei_block) : 0,
1455 EXT_FIRST_INDEX(path[depth].p_hdr) != NULL ?
1456 le32_to_cpu(EXT_FIRST_INDEX(path[depth].p_hdr)->ei_block) : 0,
1457 depth);
1458 return -EIO;
1459 }
1460 }
1461 return 0;
1462 }
1463
1464 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1465 EXT4_ERROR_INODE(inode,
1466 "logical %d < ee_block %d + ee_len %d!",
1467 *logical, le32_to_cpu(ex->ee_block), ee_len);
1468 return -EIO;
1469 }
1470
1471 *logical = le32_to_cpu(ex->ee_block) + ee_len - 1;
1472 *phys = ext4_ext_pblock(ex) + ee_len - 1;
1473 return 0;
1474 }
1475
1476 /*
1477 * search the closest allocated block to the right for *logical
1478 * and returns it at @logical + it's physical address at @phys
1479 * if *logical is the largest allocated block, the function
1480 * returns 0 at @phys
1481 * return value contains 0 (success) or error code
1482 */
1483 static int ext4_ext_search_right(struct inode *inode,
1484 struct ext4_ext_path *path,
1485 ext4_lblk_t *logical, ext4_fsblk_t *phys,
1486 struct ext4_extent **ret_ex)
1487 {
1488 struct buffer_head *bh = NULL;
1489 struct ext4_extent_header *eh;
1490 struct ext4_extent_idx *ix;
1491 struct ext4_extent *ex;
1492 ext4_fsblk_t block;
1493 int depth; /* Note, NOT eh_depth; depth from top of tree */
1494 int ee_len;
1495
1496 if (unlikely(path == NULL)) {
1497 EXT4_ERROR_INODE(inode, "path == NULL *logical %d!", *logical);
1498 return -EIO;
1499 }
1500 depth = path->p_depth;
1501 *phys = 0;
1502
1503 if (depth == 0 && path->p_ext == NULL)
1504 return 0;
1505
1506 /* usually extent in the path covers blocks smaller
1507 * then *logical, but it can be that extent is the
1508 * first one in the file */
1509
1510 ex = path[depth].p_ext;
1511 ee_len = ext4_ext_get_actual_len(ex);
1512 if (*logical < le32_to_cpu(ex->ee_block)) {
1513 if (unlikely(EXT_FIRST_EXTENT(path[depth].p_hdr) != ex)) {
1514 EXT4_ERROR_INODE(inode,
1515 "first_extent(path[%d].p_hdr) != ex",
1516 depth);
1517 return -EIO;
1518 }
1519 while (--depth >= 0) {
1520 ix = path[depth].p_idx;
1521 if (unlikely(ix != EXT_FIRST_INDEX(path[depth].p_hdr))) {
1522 EXT4_ERROR_INODE(inode,
1523 "ix != EXT_FIRST_INDEX *logical %d!",
1524 *logical);
1525 return -EIO;
1526 }
1527 }
1528 goto found_extent;
1529 }
1530
1531 if (unlikely(*logical < (le32_to_cpu(ex->ee_block) + ee_len))) {
1532 EXT4_ERROR_INODE(inode,
1533 "logical %d < ee_block %d + ee_len %d!",
1534 *logical, le32_to_cpu(ex->ee_block), ee_len);
1535 return -EIO;
1536 }
1537
1538 if (ex != EXT_LAST_EXTENT(path[depth].p_hdr)) {
1539 /* next allocated block in this leaf */
1540 ex++;
1541 goto found_extent;
1542 }
1543
1544 /* go up and search for index to the right */
1545 while (--depth >= 0) {
1546 ix = path[depth].p_idx;
1547 if (ix != EXT_LAST_INDEX(path[depth].p_hdr))
1548 goto got_index;
1549 }
1550
1551 /* we've gone up to the root and found no index to the right */
1552 return 0;
1553
1554 got_index:
1555 /* we've found index to the right, let's
1556 * follow it and find the closest allocated
1557 * block to the right */
1558 ix++;
1559 block = ext4_idx_pblock(ix);
1560 while (++depth < path->p_depth) {
1561 /* subtract from p_depth to get proper eh_depth */
1562 bh = read_extent_tree_block(inode, block,
1563 path->p_depth - depth, 0);
1564 if (IS_ERR(bh))
1565 return PTR_ERR(bh);
1566 eh = ext_block_hdr(bh);
1567 ix = EXT_FIRST_INDEX(eh);
1568 block = ext4_idx_pblock(ix);
1569 put_bh(bh);
1570 }
1571
1572 bh = read_extent_tree_block(inode, block, path->p_depth - depth, 0);
1573 if (IS_ERR(bh))
1574 return PTR_ERR(bh);
1575 eh = ext_block_hdr(bh);
1576 ex = EXT_FIRST_EXTENT(eh);
1577 found_extent:
1578 *logical = le32_to_cpu(ex->ee_block);
1579 *phys = ext4_ext_pblock(ex);
1580 *ret_ex = ex;
1581 if (bh)
1582 put_bh(bh);
1583 return 0;
1584 }
1585
1586 /*
1587 * ext4_ext_next_allocated_block:
1588 * returns allocated block in subsequent extent or EXT_MAX_BLOCKS.
1589 * NOTE: it considers block number from index entry as
1590 * allocated block. Thus, index entries have to be consistent
1591 * with leaves.
1592 */
1593 ext4_lblk_t
1594 ext4_ext_next_allocated_block(struct ext4_ext_path *path)
1595 {
1596 int depth;
1597
1598 BUG_ON(path == NULL);
1599 depth = path->p_depth;
1600
1601 if (depth == 0 && path->p_ext == NULL)
1602 return EXT_MAX_BLOCKS;
1603
1604 while (depth >= 0) {
1605 if (depth == path->p_depth) {
1606 /* leaf */
1607 if (path[depth].p_ext &&
1608 path[depth].p_ext !=
1609 EXT_LAST_EXTENT(path[depth].p_hdr))
1610 return le32_to_cpu(path[depth].p_ext[1].ee_block);
1611 } else {
1612 /* index */
1613 if (path[depth].p_idx !=
1614 EXT_LAST_INDEX(path[depth].p_hdr))
1615 return le32_to_cpu(path[depth].p_idx[1].ei_block);
1616 }
1617 depth--;
1618 }
1619
1620 return EXT_MAX_BLOCKS;
1621 }
1622
1623 /*
1624 * ext4_ext_next_leaf_block:
1625 * returns first allocated block from next leaf or EXT_MAX_BLOCKS
1626 */
1627 static ext4_lblk_t ext4_ext_next_leaf_block(struct ext4_ext_path *path)
1628 {
1629 int depth;
1630
1631 BUG_ON(path == NULL);
1632 depth = path->p_depth;
1633
1634 /* zero-tree has no leaf blocks at all */
1635 if (depth == 0)
1636 return EXT_MAX_BLOCKS;
1637
1638 /* go to index block */
1639 depth--;
1640
1641 while (depth >= 0) {
1642 if (path[depth].p_idx !=
1643 EXT_LAST_INDEX(path[depth].p_hdr))
1644 return (ext4_lblk_t)
1645 le32_to_cpu(path[depth].p_idx[1].ei_block);
1646 depth--;
1647 }
1648
1649 return EXT_MAX_BLOCKS;
1650 }
1651
1652 /*
1653 * ext4_ext_correct_indexes:
1654 * if leaf gets modified and modified extent is first in the leaf,
1655 * then we have to correct all indexes above.
1656 * TODO: do we need to correct tree in all cases?
1657 */
1658 static int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode,
1659 struct ext4_ext_path *path)
1660 {
1661 struct ext4_extent_header *eh;
1662 int depth = ext_depth(inode);
1663 struct ext4_extent *ex;
1664 __le32 border;
1665 int k, err = 0;
1666
1667 eh = path[depth].p_hdr;
1668 ex = path[depth].p_ext;
1669
1670 if (unlikely(ex == NULL || eh == NULL)) {
1671 EXT4_ERROR_INODE(inode,
1672 "ex %p == NULL or eh %p == NULL", ex, eh);
1673 return -EIO;
1674 }
1675
1676 if (depth == 0) {
1677 /* there is no tree at all */
1678 return 0;
1679 }
1680
1681 if (ex != EXT_FIRST_EXTENT(eh)) {
1682 /* we correct tree if first leaf got modified only */
1683 return 0;
1684 }
1685
1686 /*
1687 * TODO: we need correction if border is smaller than current one
1688 */
1689 k = depth - 1;
1690 border = path[depth].p_ext->ee_block;
1691 err = ext4_ext_get_access(handle, inode, path + k);
1692 if (err)
1693 return err;
1694 path[k].p_idx->ei_block = border;
1695 err = ext4_ext_dirty(handle, inode, path + k);
1696 if (err)
1697 return err;
1698
1699 while (k--) {
1700 /* change all left-side indexes */
1701 if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr))
1702 break;
1703 err = ext4_ext_get_access(handle, inode, path + k);
1704 if (err)
1705 break;
1706 path[k].p_idx->ei_block = border;
1707 err = ext4_ext_dirty(handle, inode, path + k);
1708 if (err)
1709 break;
1710 }
1711
1712 return err;
1713 }
1714
1715 int
1716 ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1,
1717 struct ext4_extent *ex2)
1718 {
1719 unsigned short ext1_ee_len, ext2_ee_len;
1720
1721 if (ext4_ext_is_unwritten(ex1) != ext4_ext_is_unwritten(ex2))
1722 return 0;
1723
1724 ext1_ee_len = ext4_ext_get_actual_len(ex1);
1725 ext2_ee_len = ext4_ext_get_actual_len(ex2);
1726
1727 if (le32_to_cpu(ex1->ee_block) + ext1_ee_len !=
1728 le32_to_cpu(ex2->ee_block))
1729 return 0;
1730
1731 /*
1732 * To allow future support for preallocated extents to be added
1733 * as an RO_COMPAT feature, refuse to merge to extents if
1734 * this can result in the top bit of ee_len being set.
1735 */
1736 if (ext1_ee_len + ext2_ee_len > EXT_INIT_MAX_LEN)
1737 return 0;
1738 if (ext4_ext_is_unwritten(ex1) &&
1739 (ext4_test_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN) ||
1740 atomic_read(&EXT4_I(inode)->i_unwritten) ||
1741 (ext1_ee_len + ext2_ee_len > EXT_UNWRITTEN_MAX_LEN)))
1742 return 0;
1743 #ifdef AGGRESSIVE_TEST
1744 if (ext1_ee_len >= 4)
1745 return 0;
1746 #endif
1747
1748 if (ext4_ext_pblock(ex1) + ext1_ee_len == ext4_ext_pblock(ex2))
1749 return 1;
1750 return 0;
1751 }
1752
1753 /*
1754 * This function tries to merge the "ex" extent to the next extent in the tree.
1755 * It always tries to merge towards right. If you want to merge towards
1756 * left, pass "ex - 1" as argument instead of "ex".
1757 * Returns 0 if the extents (ex and ex+1) were _not_ merged and returns
1758 * 1 if they got merged.
1759 */
1760 static int ext4_ext_try_to_merge_right(struct inode *inode,
1761 struct ext4_ext_path *path,
1762 struct ext4_extent *ex)
1763 {
1764 struct ext4_extent_header *eh;
1765 unsigned int depth, len;
1766 int merge_done = 0, unwritten;
1767
1768 depth = ext_depth(inode);
1769 BUG_ON(path[depth].p_hdr == NULL);
1770 eh = path[depth].p_hdr;
1771
1772 while (ex < EXT_LAST_EXTENT(eh)) {
1773 if (!ext4_can_extents_be_merged(inode, ex, ex + 1))
1774 break;
1775 /* merge with next extent! */
1776 unwritten = ext4_ext_is_unwritten(ex);
1777 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1778 + ext4_ext_get_actual_len(ex + 1));
1779 if (unwritten)
1780 ext4_ext_mark_unwritten(ex);
1781
1782 if (ex + 1 < EXT_LAST_EXTENT(eh)) {
1783 len = (EXT_LAST_EXTENT(eh) - ex - 1)
1784 * sizeof(struct ext4_extent);
1785 memmove(ex + 1, ex + 2, len);
1786 }
1787 le16_add_cpu(&eh->eh_entries, -1);
1788 merge_done = 1;
1789 WARN_ON(eh->eh_entries == 0);
1790 if (!eh->eh_entries)
1791 EXT4_ERROR_INODE(inode, "eh->eh_entries = 0!");
1792 }
1793
1794 return merge_done;
1795 }
1796
1797 /*
1798 * This function does a very simple check to see if we can collapse
1799 * an extent tree with a single extent tree leaf block into the inode.
1800 */
1801 static void ext4_ext_try_to_merge_up(handle_t *handle,
1802 struct inode *inode,
1803 struct ext4_ext_path *path)
1804 {
1805 size_t s;
1806 unsigned max_root = ext4_ext_space_root(inode, 0);
1807 ext4_fsblk_t blk;
1808
1809 if ((path[0].p_depth != 1) ||
1810 (le16_to_cpu(path[0].p_hdr->eh_entries) != 1) ||
1811 (le16_to_cpu(path[1].p_hdr->eh_entries) > max_root))
1812 return;
1813
1814 /*
1815 * We need to modify the block allocation bitmap and the block
1816 * group descriptor to release the extent tree block. If we
1817 * can't get the journal credits, give up.
1818 */
1819 if (ext4_journal_extend(handle, 2))
1820 return;
1821
1822 /*
1823 * Copy the extent data up to the inode
1824 */
1825 blk = ext4_idx_pblock(path[0].p_idx);
1826 s = le16_to_cpu(path[1].p_hdr->eh_entries) *
1827 sizeof(struct ext4_extent_idx);
1828 s += sizeof(struct ext4_extent_header);
1829
1830 path[1].p_maxdepth = path[0].p_maxdepth;
1831 memcpy(path[0].p_hdr, path[1].p_hdr, s);
1832 path[0].p_depth = 0;
1833 path[0].p_ext = EXT_FIRST_EXTENT(path[0].p_hdr) +
1834 (path[1].p_ext - EXT_FIRST_EXTENT(path[1].p_hdr));
1835 path[0].p_hdr->eh_max = cpu_to_le16(max_root);
1836
1837 brelse(path[1].p_bh);
1838 ext4_free_blocks(handle, inode, NULL, blk, 1,
1839 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
1840 }
1841
1842 /*
1843 * This function tries to merge the @ex extent to neighbours in the tree.
1844 * return 1 if merge left else 0.
1845 */
1846 static void ext4_ext_try_to_merge(handle_t *handle,
1847 struct inode *inode,
1848 struct ext4_ext_path *path,
1849 struct ext4_extent *ex) {
1850 struct ext4_extent_header *eh;
1851 unsigned int depth;
1852 int merge_done = 0;
1853
1854 depth = ext_depth(inode);
1855 BUG_ON(path[depth].p_hdr == NULL);
1856 eh = path[depth].p_hdr;
1857
1858 if (ex > EXT_FIRST_EXTENT(eh))
1859 merge_done = ext4_ext_try_to_merge_right(inode, path, ex - 1);
1860
1861 if (!merge_done)
1862 (void) ext4_ext_try_to_merge_right(inode, path, ex);
1863
1864 ext4_ext_try_to_merge_up(handle, inode, path);
1865 }
1866
1867 /*
1868 * check if a portion of the "newext" extent overlaps with an
1869 * existing extent.
1870 *
1871 * If there is an overlap discovered, it updates the length of the newext
1872 * such that there will be no overlap, and then returns 1.
1873 * If there is no overlap found, it returns 0.
1874 */
1875 static unsigned int ext4_ext_check_overlap(struct ext4_sb_info *sbi,
1876 struct inode *inode,
1877 struct ext4_extent *newext,
1878 struct ext4_ext_path *path)
1879 {
1880 ext4_lblk_t b1, b2;
1881 unsigned int depth, len1;
1882 unsigned int ret = 0;
1883
1884 b1 = le32_to_cpu(newext->ee_block);
1885 len1 = ext4_ext_get_actual_len(newext);
1886 depth = ext_depth(inode);
1887 if (!path[depth].p_ext)
1888 goto out;
1889 b2 = EXT4_LBLK_CMASK(sbi, le32_to_cpu(path[depth].p_ext->ee_block));
1890
1891 /*
1892 * get the next allocated block if the extent in the path
1893 * is before the requested block(s)
1894 */
1895 if (b2 < b1) {
1896 b2 = ext4_ext_next_allocated_block(path);
1897 if (b2 == EXT_MAX_BLOCKS)
1898 goto out;
1899 b2 = EXT4_LBLK_CMASK(sbi, b2);
1900 }
1901
1902 /* check for wrap through zero on extent logical start block*/
1903 if (b1 + len1 < b1) {
1904 len1 = EXT_MAX_BLOCKS - b1;
1905 newext->ee_len = cpu_to_le16(len1);
1906 ret = 1;
1907 }
1908
1909 /* check for overlap */
1910 if (b1 + len1 > b2) {
1911 newext->ee_len = cpu_to_le16(b2 - b1);
1912 ret = 1;
1913 }
1914 out:
1915 return ret;
1916 }
1917
1918 /*
1919 * ext4_ext_insert_extent:
1920 * tries to merge requsted extent into the existing extent or
1921 * inserts requested extent as new one into the tree,
1922 * creating new leaf in the no-space case.
1923 */
1924 int ext4_ext_insert_extent(handle_t *handle, struct inode *inode,
1925 struct ext4_ext_path **ppath,
1926 struct ext4_extent *newext, int gb_flags)
1927 {
1928 struct ext4_ext_path *path = *ppath;
1929 struct ext4_extent_header *eh;
1930 struct ext4_extent *ex, *fex;
1931 struct ext4_extent *nearex; /* nearest extent */
1932 struct ext4_ext_path *npath = NULL;
1933 int depth, len, err;
1934 ext4_lblk_t next;
1935 int mb_flags = 0, unwritten;
1936
1937 if (gb_flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
1938 mb_flags |= EXT4_MB_DELALLOC_RESERVED;
1939 if (unlikely(ext4_ext_get_actual_len(newext) == 0)) {
1940 EXT4_ERROR_INODE(inode, "ext4_ext_get_actual_len(newext) == 0");
1941 return -EIO;
1942 }
1943 depth = ext_depth(inode);
1944 ex = path[depth].p_ext;
1945 eh = path[depth].p_hdr;
1946 if (unlikely(path[depth].p_hdr == NULL)) {
1947 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
1948 return -EIO;
1949 }
1950
1951 /* try to insert block into found extent and return */
1952 if (ex && !(gb_flags & EXT4_GET_BLOCKS_PRE_IO)) {
1953
1954 /*
1955 * Try to see whether we should rather test the extent on
1956 * right from ex, or from the left of ex. This is because
1957 * ext4_find_extent() can return either extent on the
1958 * left, or on the right from the searched position. This
1959 * will make merging more effective.
1960 */
1961 if (ex < EXT_LAST_EXTENT(eh) &&
1962 (le32_to_cpu(ex->ee_block) +
1963 ext4_ext_get_actual_len(ex) <
1964 le32_to_cpu(newext->ee_block))) {
1965 ex += 1;
1966 goto prepend;
1967 } else if ((ex > EXT_FIRST_EXTENT(eh)) &&
1968 (le32_to_cpu(newext->ee_block) +
1969 ext4_ext_get_actual_len(newext) <
1970 le32_to_cpu(ex->ee_block)))
1971 ex -= 1;
1972
1973 /* Try to append newex to the ex */
1974 if (ext4_can_extents_be_merged(inode, ex, newext)) {
1975 ext_debug("append [%d]%d block to %u:[%d]%d"
1976 "(from %llu)\n",
1977 ext4_ext_is_unwritten(newext),
1978 ext4_ext_get_actual_len(newext),
1979 le32_to_cpu(ex->ee_block),
1980 ext4_ext_is_unwritten(ex),
1981 ext4_ext_get_actual_len(ex),
1982 ext4_ext_pblock(ex));
1983 err = ext4_ext_get_access(handle, inode,
1984 path + depth);
1985 if (err)
1986 return err;
1987 unwritten = ext4_ext_is_unwritten(ex);
1988 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
1989 + ext4_ext_get_actual_len(newext));
1990 if (unwritten)
1991 ext4_ext_mark_unwritten(ex);
1992 eh = path[depth].p_hdr;
1993 nearex = ex;
1994 goto merge;
1995 }
1996
1997 prepend:
1998 /* Try to prepend newex to the ex */
1999 if (ext4_can_extents_be_merged(inode, newext, ex)) {
2000 ext_debug("prepend %u[%d]%d block to %u:[%d]%d"
2001 "(from %llu)\n",
2002 le32_to_cpu(newext->ee_block),
2003 ext4_ext_is_unwritten(newext),
2004 ext4_ext_get_actual_len(newext),
2005 le32_to_cpu(ex->ee_block),
2006 ext4_ext_is_unwritten(ex),
2007 ext4_ext_get_actual_len(ex),
2008 ext4_ext_pblock(ex));
2009 err = ext4_ext_get_access(handle, inode,
2010 path + depth);
2011 if (err)
2012 return err;
2013
2014 unwritten = ext4_ext_is_unwritten(ex);
2015 ex->ee_block = newext->ee_block;
2016 ext4_ext_store_pblock(ex, ext4_ext_pblock(newext));
2017 ex->ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex)
2018 + ext4_ext_get_actual_len(newext));
2019 if (unwritten)
2020 ext4_ext_mark_unwritten(ex);
2021 eh = path[depth].p_hdr;
2022 nearex = ex;
2023 goto merge;
2024 }
2025 }
2026
2027 depth = ext_depth(inode);
2028 eh = path[depth].p_hdr;
2029 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max))
2030 goto has_space;
2031
2032 /* probably next leaf has space for us? */
2033 fex = EXT_LAST_EXTENT(eh);
2034 next = EXT_MAX_BLOCKS;
2035 if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block))
2036 next = ext4_ext_next_leaf_block(path);
2037 if (next != EXT_MAX_BLOCKS) {
2038 ext_debug("next leaf block - %u\n", next);
2039 BUG_ON(npath != NULL);
2040 npath = ext4_find_extent(inode, next, NULL, 0);
2041 if (IS_ERR(npath))
2042 return PTR_ERR(npath);
2043 BUG_ON(npath->p_depth != path->p_depth);
2044 eh = npath[depth].p_hdr;
2045 if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) {
2046 ext_debug("next leaf isn't full(%d)\n",
2047 le16_to_cpu(eh->eh_entries));
2048 path = npath;
2049 goto has_space;
2050 }
2051 ext_debug("next leaf has no free space(%d,%d)\n",
2052 le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max));
2053 }
2054
2055 /*
2056 * There is no free space in the found leaf.
2057 * We're gonna add a new leaf in the tree.
2058 */
2059 if (gb_flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
2060 mb_flags |= EXT4_MB_USE_RESERVED;
2061 err = ext4_ext_create_new_leaf(handle, inode, mb_flags, gb_flags,
2062 ppath, newext);
2063 if (err)
2064 goto cleanup;
2065 depth = ext_depth(inode);
2066 eh = path[depth].p_hdr;
2067
2068 has_space:
2069 nearex = path[depth].p_ext;
2070
2071 err = ext4_ext_get_access(handle, inode, path + depth);
2072 if (err)
2073 goto cleanup;
2074
2075 if (!nearex) {
2076 /* there is no extent in this leaf, create first one */
2077 ext_debug("first extent in the leaf: %u:%llu:[%d]%d\n",
2078 le32_to_cpu(newext->ee_block),
2079 ext4_ext_pblock(newext),
2080 ext4_ext_is_unwritten(newext),
2081 ext4_ext_get_actual_len(newext));
2082 nearex = EXT_FIRST_EXTENT(eh);
2083 } else {
2084 if (le32_to_cpu(newext->ee_block)
2085 > le32_to_cpu(nearex->ee_block)) {
2086 /* Insert after */
2087 ext_debug("insert %u:%llu:[%d]%d before: "
2088 "nearest %p\n",
2089 le32_to_cpu(newext->ee_block),
2090 ext4_ext_pblock(newext),
2091 ext4_ext_is_unwritten(newext),
2092 ext4_ext_get_actual_len(newext),
2093 nearex);
2094 nearex++;
2095 } else {
2096 /* Insert before */
2097 BUG_ON(newext->ee_block == nearex->ee_block);
2098 ext_debug("insert %u:%llu:[%d]%d after: "
2099 "nearest %p\n",
2100 le32_to_cpu(newext->ee_block),
2101 ext4_ext_pblock(newext),
2102 ext4_ext_is_unwritten(newext),
2103 ext4_ext_get_actual_len(newext),
2104 nearex);
2105 }
2106 len = EXT_LAST_EXTENT(eh) - nearex + 1;
2107 if (len > 0) {
2108 ext_debug("insert %u:%llu:[%d]%d: "
2109 "move %d extents from 0x%p to 0x%p\n",
2110 le32_to_cpu(newext->ee_block),
2111 ext4_ext_pblock(newext),
2112 ext4_ext_is_unwritten(newext),
2113 ext4_ext_get_actual_len(newext),
2114 len, nearex, nearex + 1);
2115 memmove(nearex + 1, nearex,
2116 len * sizeof(struct ext4_extent));
2117 }
2118 }
2119
2120 le16_add_cpu(&eh->eh_entries, 1);
2121 path[depth].p_ext = nearex;
2122 nearex->ee_block = newext->ee_block;
2123 ext4_ext_store_pblock(nearex, ext4_ext_pblock(newext));
2124 nearex->ee_len = newext->ee_len;
2125
2126 merge:
2127 /* try to merge extents */
2128 if (!(gb_flags & EXT4_GET_BLOCKS_PRE_IO))
2129 ext4_ext_try_to_merge(handle, inode, path, nearex);
2130
2131
2132 /* time to correct all indexes above */
2133 err = ext4_ext_correct_indexes(handle, inode, path);
2134 if (err)
2135 goto cleanup;
2136
2137 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
2138
2139 cleanup:
2140 ext4_ext_drop_refs(npath);
2141 kfree(npath);
2142 return err;
2143 }
2144
2145 static int ext4_fill_fiemap_extents(struct inode *inode,
2146 ext4_lblk_t block, ext4_lblk_t num,
2147 struct fiemap_extent_info *fieinfo)
2148 {
2149 struct ext4_ext_path *path = NULL;
2150 struct ext4_extent *ex;
2151 struct extent_status es;
2152 ext4_lblk_t next, next_del, start = 0, end = 0;
2153 ext4_lblk_t last = block + num;
2154 int exists, depth = 0, err = 0;
2155 unsigned int flags = 0;
2156 unsigned char blksize_bits = inode->i_sb->s_blocksize_bits;
2157
2158 while (block < last && block != EXT_MAX_BLOCKS) {
2159 num = last - block;
2160 /* find extent for this block */
2161 down_read(&EXT4_I(inode)->i_data_sem);
2162
2163 path = ext4_find_extent(inode, block, &path, 0);
2164 if (IS_ERR(path)) {
2165 up_read(&EXT4_I(inode)->i_data_sem);
2166 err = PTR_ERR(path);
2167 path = NULL;
2168 break;
2169 }
2170
2171 depth = ext_depth(inode);
2172 if (unlikely(path[depth].p_hdr == NULL)) {
2173 up_read(&EXT4_I(inode)->i_data_sem);
2174 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2175 err = -EIO;
2176 break;
2177 }
2178 ex = path[depth].p_ext;
2179 next = ext4_ext_next_allocated_block(path);
2180
2181 flags = 0;
2182 exists = 0;
2183 if (!ex) {
2184 /* there is no extent yet, so try to allocate
2185 * all requested space */
2186 start = block;
2187 end = block + num;
2188 } else if (le32_to_cpu(ex->ee_block) > block) {
2189 /* need to allocate space before found extent */
2190 start = block;
2191 end = le32_to_cpu(ex->ee_block);
2192 if (block + num < end)
2193 end = block + num;
2194 } else if (block >= le32_to_cpu(ex->ee_block)
2195 + ext4_ext_get_actual_len(ex)) {
2196 /* need to allocate space after found extent */
2197 start = block;
2198 end = block + num;
2199 if (end >= next)
2200 end = next;
2201 } else if (block >= le32_to_cpu(ex->ee_block)) {
2202 /*
2203 * some part of requested space is covered
2204 * by found extent
2205 */
2206 start = block;
2207 end = le32_to_cpu(ex->ee_block)
2208 + ext4_ext_get_actual_len(ex);
2209 if (block + num < end)
2210 end = block + num;
2211 exists = 1;
2212 } else {
2213 BUG();
2214 }
2215 BUG_ON(end <= start);
2216
2217 if (!exists) {
2218 es.es_lblk = start;
2219 es.es_len = end - start;
2220 es.es_pblk = 0;
2221 } else {
2222 es.es_lblk = le32_to_cpu(ex->ee_block);
2223 es.es_len = ext4_ext_get_actual_len(ex);
2224 es.es_pblk = ext4_ext_pblock(ex);
2225 if (ext4_ext_is_unwritten(ex))
2226 flags |= FIEMAP_EXTENT_UNWRITTEN;
2227 }
2228
2229 /*
2230 * Find delayed extent and update es accordingly. We call
2231 * it even in !exists case to find out whether es is the
2232 * last existing extent or not.
2233 */
2234 next_del = ext4_find_delayed_extent(inode, &es);
2235 if (!exists && next_del) {
2236 exists = 1;
2237 flags |= (FIEMAP_EXTENT_DELALLOC |
2238 FIEMAP_EXTENT_UNKNOWN);
2239 }
2240 up_read(&EXT4_I(inode)->i_data_sem);
2241
2242 if (unlikely(es.es_len == 0)) {
2243 EXT4_ERROR_INODE(inode, "es.es_len == 0");
2244 err = -EIO;
2245 break;
2246 }
2247
2248 /*
2249 * This is possible iff next == next_del == EXT_MAX_BLOCKS.
2250 * we need to check next == EXT_MAX_BLOCKS because it is
2251 * possible that an extent is with unwritten and delayed
2252 * status due to when an extent is delayed allocated and
2253 * is allocated by fallocate status tree will track both of
2254 * them in a extent.
2255 *
2256 * So we could return a unwritten and delayed extent, and
2257 * its block is equal to 'next'.
2258 */
2259 if (next == next_del && next == EXT_MAX_BLOCKS) {
2260 flags |= FIEMAP_EXTENT_LAST;
2261 if (unlikely(next_del != EXT_MAX_BLOCKS ||
2262 next != EXT_MAX_BLOCKS)) {
2263 EXT4_ERROR_INODE(inode,
2264 "next extent == %u, next "
2265 "delalloc extent = %u",
2266 next, next_del);
2267 err = -EIO;
2268 break;
2269 }
2270 }
2271
2272 if (exists) {
2273 err = fiemap_fill_next_extent(fieinfo,
2274 (__u64)es.es_lblk << blksize_bits,
2275 (__u64)es.es_pblk << blksize_bits,
2276 (__u64)es.es_len << blksize_bits,
2277 flags);
2278 if (err < 0)
2279 break;
2280 if (err == 1) {
2281 err = 0;
2282 break;
2283 }
2284 }
2285
2286 block = es.es_lblk + es.es_len;
2287 }
2288
2289 ext4_ext_drop_refs(path);
2290 kfree(path);
2291 return err;
2292 }
2293
2294 /*
2295 * ext4_ext_put_gap_in_cache:
2296 * calculate boundaries of the gap that the requested block fits into
2297 * and cache this gap
2298 */
2299 static void
2300 ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path,
2301 ext4_lblk_t block)
2302 {
2303 int depth = ext_depth(inode);
2304 ext4_lblk_t len;
2305 ext4_lblk_t lblock;
2306 struct ext4_extent *ex;
2307 struct extent_status es;
2308
2309 ex = path[depth].p_ext;
2310 if (ex == NULL) {
2311 /* there is no extent yet, so gap is [0;-] */
2312 lblock = 0;
2313 len = EXT_MAX_BLOCKS;
2314 ext_debug("cache gap(whole file):");
2315 } else if (block < le32_to_cpu(ex->ee_block)) {
2316 lblock = block;
2317 len = le32_to_cpu(ex->ee_block) - block;
2318 ext_debug("cache gap(before): %u [%u:%u]",
2319 block,
2320 le32_to_cpu(ex->ee_block),
2321 ext4_ext_get_actual_len(ex));
2322 } else if (block >= le32_to_cpu(ex->ee_block)
2323 + ext4_ext_get_actual_len(ex)) {
2324 ext4_lblk_t next;
2325 lblock = le32_to_cpu(ex->ee_block)
2326 + ext4_ext_get_actual_len(ex);
2327
2328 next = ext4_ext_next_allocated_block(path);
2329 ext_debug("cache gap(after): [%u:%u] %u",
2330 le32_to_cpu(ex->ee_block),
2331 ext4_ext_get_actual_len(ex),
2332 block);
2333 BUG_ON(next == lblock);
2334 len = next - lblock;
2335 } else {
2336 BUG();
2337 }
2338
2339 ext4_es_find_delayed_extent_range(inode, lblock, lblock + len - 1, &es);
2340 if (es.es_len) {
2341 /* There's delayed extent containing lblock? */
2342 if (es.es_lblk <= lblock)
2343 return;
2344 len = min(es.es_lblk - lblock, len);
2345 }
2346 ext_debug(" -> %u:%u\n", lblock, len);
2347 ext4_es_insert_extent(inode, lblock, len, ~0, EXTENT_STATUS_HOLE);
2348 }
2349
2350 /*
2351 * ext4_ext_rm_idx:
2352 * removes index from the index block.
2353 */
2354 static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
2355 struct ext4_ext_path *path, int depth)
2356 {
2357 int err;
2358 ext4_fsblk_t leaf;
2359
2360 /* free index block */
2361 depth--;
2362 path = path + depth;
2363 leaf = ext4_idx_pblock(path->p_idx);
2364 if (unlikely(path->p_hdr->eh_entries == 0)) {
2365 EXT4_ERROR_INODE(inode, "path->p_hdr->eh_entries == 0");
2366 return -EIO;
2367 }
2368 err = ext4_ext_get_access(handle, inode, path);
2369 if (err)
2370 return err;
2371
2372 if (path->p_idx != EXT_LAST_INDEX(path->p_hdr)) {
2373 int len = EXT_LAST_INDEX(path->p_hdr) - path->p_idx;
2374 len *= sizeof(struct ext4_extent_idx);
2375 memmove(path->p_idx, path->p_idx + 1, len);
2376 }
2377
2378 le16_add_cpu(&path->p_hdr->eh_entries, -1);
2379 err = ext4_ext_dirty(handle, inode, path);
2380 if (err)
2381 return err;
2382 ext_debug("index is empty, remove it, free block %llu\n", leaf);
2383 trace_ext4_ext_rm_idx(inode, leaf);
2384
2385 ext4_free_blocks(handle, inode, NULL, leaf, 1,
2386 EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
2387
2388 while (--depth >= 0) {
2389 if (path->p_idx != EXT_FIRST_INDEX(path->p_hdr))
2390 break;
2391 path--;
2392 err = ext4_ext_get_access(handle, inode, path);
2393 if (err)
2394 break;
2395 path->p_idx->ei_block = (path+1)->p_idx->ei_block;
2396 err = ext4_ext_dirty(handle, inode, path);
2397 if (err)
2398 break;
2399 }
2400 return err;
2401 }
2402
2403 /*
2404 * ext4_ext_calc_credits_for_single_extent:
2405 * This routine returns max. credits that needed to insert an extent
2406 * to the extent tree.
2407 * When pass the actual path, the caller should calculate credits
2408 * under i_data_sem.
2409 */
2410 int ext4_ext_calc_credits_for_single_extent(struct inode *inode, int nrblocks,
2411 struct ext4_ext_path *path)
2412 {
2413 if (path) {
2414 int depth = ext_depth(inode);
2415 int ret = 0;
2416
2417 /* probably there is space in leaf? */
2418 if (le16_to_cpu(path[depth].p_hdr->eh_entries)
2419 < le16_to_cpu(path[depth].p_hdr->eh_max)) {
2420
2421 /*
2422 * There are some space in the leaf tree, no
2423 * need to account for leaf block credit
2424 *
2425 * bitmaps and block group descriptor blocks
2426 * and other metadata blocks still need to be
2427 * accounted.
2428 */
2429 /* 1 bitmap, 1 block group descriptor */
2430 ret = 2 + EXT4_META_TRANS_BLOCKS(inode->i_sb);
2431 return ret;
2432 }
2433 }
2434
2435 return ext4_chunk_trans_blocks(inode, nrblocks);
2436 }
2437
2438 /*
2439 * How many index/leaf blocks need to change/allocate to add @extents extents?
2440 *
2441 * If we add a single extent, then in the worse case, each tree level
2442 * index/leaf need to be changed in case of the tree split.
2443 *
2444 * If more extents are inserted, they could cause the whole tree split more
2445 * than once, but this is really rare.
2446 */
2447 int ext4_ext_index_trans_blocks(struct inode *inode, int extents)
2448 {
2449 int index;
2450 int depth;
2451
2452 /* If we are converting the inline data, only one is needed here. */
2453 if (ext4_has_inline_data(inode))
2454 return 1;
2455
2456 depth = ext_depth(inode);
2457
2458 if (extents <= 1)
2459 index = depth * 2;
2460 else
2461 index = depth * 3;
2462
2463 return index;
2464 }
2465
2466 static inline int get_default_free_blocks_flags(struct inode *inode)
2467 {
2468 if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
2469 return EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET;
2470 else if (ext4_should_journal_data(inode))
2471 return EXT4_FREE_BLOCKS_FORGET;
2472 return 0;
2473 }
2474
2475 static int ext4_remove_blocks(handle_t *handle, struct inode *inode,
2476 struct ext4_extent *ex,
2477 long long *partial_cluster,
2478 ext4_lblk_t from, ext4_lblk_t to)
2479 {
2480 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2481 unsigned short ee_len = ext4_ext_get_actual_len(ex);
2482 ext4_fsblk_t pblk;
2483 int flags = get_default_free_blocks_flags(inode);
2484
2485 /*
2486 * For bigalloc file systems, we never free a partial cluster
2487 * at the beginning of the extent. Instead, we make a note
2488 * that we tried freeing the cluster, and check to see if we
2489 * need to free it on a subsequent call to ext4_remove_blocks,
2490 * or at the end of ext4_ext_rm_leaf or ext4_ext_remove_space.
2491 */
2492 flags |= EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER;
2493
2494 trace_ext4_remove_blocks(inode, ex, from, to, *partial_cluster);
2495 /*
2496 * If we have a partial cluster, and it's different from the
2497 * cluster of the last block, we need to explicitly free the
2498 * partial cluster here.
2499 */
2500 pblk = ext4_ext_pblock(ex) + ee_len - 1;
2501 if (*partial_cluster > 0 &&
2502 *partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2503 ext4_free_blocks(handle, inode, NULL,
2504 EXT4_C2B(sbi, *partial_cluster),
2505 sbi->s_cluster_ratio, flags);
2506 *partial_cluster = 0;
2507 }
2508
2509 #ifdef EXTENTS_STATS
2510 {
2511 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2512 spin_lock(&sbi->s_ext_stats_lock);
2513 sbi->s_ext_blocks += ee_len;
2514 sbi->s_ext_extents++;
2515 if (ee_len < sbi->s_ext_min)
2516 sbi->s_ext_min = ee_len;
2517 if (ee_len > sbi->s_ext_max)
2518 sbi->s_ext_max = ee_len;
2519 if (ext_depth(inode) > sbi->s_depth_max)
2520 sbi->s_depth_max = ext_depth(inode);
2521 spin_unlock(&sbi->s_ext_stats_lock);
2522 }
2523 #endif
2524 if (from >= le32_to_cpu(ex->ee_block)
2525 && to == le32_to_cpu(ex->ee_block) + ee_len - 1) {
2526 /* tail removal */
2527 ext4_lblk_t num;
2528 long long first_cluster;
2529
2530 num = le32_to_cpu(ex->ee_block) + ee_len - from;
2531 pblk = ext4_ext_pblock(ex) + ee_len - num;
2532 /*
2533 * Usually we want to free partial cluster at the end of the
2534 * extent, except for the situation when the cluster is still
2535 * used by any other extent (partial_cluster is negative).
2536 */
2537 if (*partial_cluster < 0 &&
2538 *partial_cluster == -(long long) EXT4_B2C(sbi, pblk+num-1))
2539 flags |= EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER;
2540
2541 ext_debug("free last %u blocks starting %llu partial %lld\n",
2542 num, pblk, *partial_cluster);
2543 ext4_free_blocks(handle, inode, NULL, pblk, num, flags);
2544 /*
2545 * If the block range to be freed didn't start at the
2546 * beginning of a cluster, and we removed the entire
2547 * extent and the cluster is not used by any other extent,
2548 * save the partial cluster here, since we might need to
2549 * delete if we determine that the truncate or punch hole
2550 * operation has removed all of the blocks in the cluster.
2551 * If that cluster is used by another extent, preserve its
2552 * negative value so it isn't freed later on.
2553 *
2554 * If the whole extent wasn't freed, we've reached the
2555 * start of the truncated/punched region and have finished
2556 * removing blocks. If there's a partial cluster here it's
2557 * shared with the remainder of the extent and is no longer
2558 * a candidate for removal.
2559 */
2560 if (EXT4_PBLK_COFF(sbi, pblk) && ee_len == num) {
2561 first_cluster = (long long) EXT4_B2C(sbi, pblk);
2562 if (first_cluster != -*partial_cluster)
2563 *partial_cluster = first_cluster;
2564 } else {
2565 *partial_cluster = 0;
2566 }
2567 } else
2568 ext4_error(sbi->s_sb, "strange request: removal(2) "
2569 "%u-%u from %u:%u\n",
2570 from, to, le32_to_cpu(ex->ee_block), ee_len);
2571 return 0;
2572 }
2573
2574
2575 /*
2576 * ext4_ext_rm_leaf() Removes the extents associated with the
2577 * blocks appearing between "start" and "end". Both "start"
2578 * and "end" must appear in the same extent or EIO is returned.
2579 *
2580 * @handle: The journal handle
2581 * @inode: The files inode
2582 * @path: The path to the leaf
2583 * @partial_cluster: The cluster which we'll have to free if all extents
2584 * has been released from it. However, if this value is
2585 * negative, it's a cluster just to the right of the
2586 * punched region and it must not be freed.
2587 * @start: The first block to remove
2588 * @end: The last block to remove
2589 */
2590 static int
2591 ext4_ext_rm_leaf(handle_t *handle, struct inode *inode,
2592 struct ext4_ext_path *path,
2593 long long *partial_cluster,
2594 ext4_lblk_t start, ext4_lblk_t end)
2595 {
2596 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2597 int err = 0, correct_index = 0;
2598 int depth = ext_depth(inode), credits;
2599 struct ext4_extent_header *eh;
2600 ext4_lblk_t a, b;
2601 unsigned num;
2602 ext4_lblk_t ex_ee_block;
2603 unsigned short ex_ee_len;
2604 unsigned unwritten = 0;
2605 struct ext4_extent *ex;
2606 ext4_fsblk_t pblk;
2607
2608 /* the header must be checked already in ext4_ext_remove_space() */
2609 ext_debug("truncate since %u in leaf to %u\n", start, end);
2610 if (!path[depth].p_hdr)
2611 path[depth].p_hdr = ext_block_hdr(path[depth].p_bh);
2612 eh = path[depth].p_hdr;
2613 if (unlikely(path[depth].p_hdr == NULL)) {
2614 EXT4_ERROR_INODE(inode, "path[%d].p_hdr == NULL", depth);
2615 return -EIO;
2616 }
2617 /* find where to start removing */
2618 ex = path[depth].p_ext;
2619 if (!ex)
2620 ex = EXT_LAST_EXTENT(eh);
2621
2622 ex_ee_block = le32_to_cpu(ex->ee_block);
2623 ex_ee_len = ext4_ext_get_actual_len(ex);
2624
2625 trace_ext4_ext_rm_leaf(inode, start, ex, *partial_cluster);
2626
2627 while (ex >= EXT_FIRST_EXTENT(eh) &&
2628 ex_ee_block + ex_ee_len > start) {
2629
2630 if (ext4_ext_is_unwritten(ex))
2631 unwritten = 1;
2632 else
2633 unwritten = 0;
2634
2635 ext_debug("remove ext %u:[%d]%d\n", ex_ee_block,
2636 unwritten, ex_ee_len);
2637 path[depth].p_ext = ex;
2638
2639 a = ex_ee_block > start ? ex_ee_block : start;
2640 b = ex_ee_block+ex_ee_len - 1 < end ?
2641 ex_ee_block+ex_ee_len - 1 : end;
2642
2643 ext_debug(" border %u:%u\n", a, b);
2644
2645 /* If this extent is beyond the end of the hole, skip it */
2646 if (end < ex_ee_block) {
2647 /*
2648 * We're going to skip this extent and move to another,
2649 * so note that its first cluster is in use to avoid
2650 * freeing it when removing blocks. Eventually, the
2651 * right edge of the truncated/punched region will
2652 * be just to the left.
2653 */
2654 if (sbi->s_cluster_ratio > 1) {
2655 pblk = ext4_ext_pblock(ex);
2656 *partial_cluster =
2657 -(long long) EXT4_B2C(sbi, pblk);
2658 }
2659 ex--;
2660 ex_ee_block = le32_to_cpu(ex->ee_block);
2661 ex_ee_len = ext4_ext_get_actual_len(ex);
2662 continue;
2663 } else if (b != ex_ee_block + ex_ee_len - 1) {
2664 EXT4_ERROR_INODE(inode,
2665 "can not handle truncate %u:%u "
2666 "on extent %u:%u",
2667 start, end, ex_ee_block,
2668 ex_ee_block + ex_ee_len - 1);
2669 err = -EIO;
2670 goto out;
2671 } else if (a != ex_ee_block) {
2672 /* remove tail of the extent */
2673 num = a - ex_ee_block;
2674 } else {
2675 /* remove whole extent: excellent! */
2676 num = 0;
2677 }
2678 /*
2679 * 3 for leaf, sb, and inode plus 2 (bmap and group
2680 * descriptor) for each block group; assume two block
2681 * groups plus ex_ee_len/blocks_per_block_group for
2682 * the worst case
2683 */
2684 credits = 7 + 2*(ex_ee_len/EXT4_BLOCKS_PER_GROUP(inode->i_sb));
2685 if (ex == EXT_FIRST_EXTENT(eh)) {
2686 correct_index = 1;
2687 credits += (ext_depth(inode)) + 1;
2688 }
2689 credits += EXT4_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
2690
2691 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
2692 if (err)
2693 goto out;
2694
2695 err = ext4_ext_get_access(handle, inode, path + depth);
2696 if (err)
2697 goto out;
2698
2699 err = ext4_remove_blocks(handle, inode, ex, partial_cluster,
2700 a, b);
2701 if (err)
2702 goto out;
2703
2704 if (num == 0)
2705 /* this extent is removed; mark slot entirely unused */
2706 ext4_ext_store_pblock(ex, 0);
2707
2708 ex->ee_len = cpu_to_le16(num);
2709 /*
2710 * Do not mark unwritten if all the blocks in the
2711 * extent have been removed.
2712 */
2713 if (unwritten && num)
2714 ext4_ext_mark_unwritten(ex);
2715 /*
2716 * If the extent was completely released,
2717 * we need to remove it from the leaf
2718 */
2719 if (num == 0) {
2720 if (end != EXT_MAX_BLOCKS - 1) {
2721 /*
2722 * For hole punching, we need to scoot all the
2723 * extents up when an extent is removed so that
2724 * we dont have blank extents in the middle
2725 */
2726 memmove(ex, ex+1, (EXT_LAST_EXTENT(eh) - ex) *
2727 sizeof(struct ext4_extent));
2728
2729 /* Now get rid of the one at the end */
2730 memset(EXT_LAST_EXTENT(eh), 0,
2731 sizeof(struct ext4_extent));
2732 }
2733 le16_add_cpu(&eh->eh_entries, -1);
2734 }
2735
2736 err = ext4_ext_dirty(handle, inode, path + depth);
2737 if (err)
2738 goto out;
2739
2740 ext_debug("new extent: %u:%u:%llu\n", ex_ee_block, num,
2741 ext4_ext_pblock(ex));
2742 ex--;
2743 ex_ee_block = le32_to_cpu(ex->ee_block);
2744 ex_ee_len = ext4_ext_get_actual_len(ex);
2745 }
2746
2747 if (correct_index && eh->eh_entries)
2748 err = ext4_ext_correct_indexes(handle, inode, path);
2749
2750 /*
2751 * If there's a partial cluster and at least one extent remains in
2752 * the leaf, free the partial cluster if it isn't shared with the
2753 * current extent. If it is shared with the current extent
2754 * we zero partial_cluster because we've reached the start of the
2755 * truncated/punched region and we're done removing blocks.
2756 */
2757 if (*partial_cluster > 0 && ex >= EXT_FIRST_EXTENT(eh)) {
2758 pblk = ext4_ext_pblock(ex) + ex_ee_len - 1;
2759 if (*partial_cluster != (long long) EXT4_B2C(sbi, pblk)) {
2760 ext4_free_blocks(handle, inode, NULL,
2761 EXT4_C2B(sbi, *partial_cluster),
2762 sbi->s_cluster_ratio,
2763 get_default_free_blocks_flags(inode));
2764 }
2765 *partial_cluster = 0;
2766 }
2767
2768 /* if this leaf is free, then we should
2769 * remove it from index block above */
2770 if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL)
2771 err = ext4_ext_rm_idx(handle, inode, path, depth);
2772
2773 out:
2774 return err;
2775 }
2776
2777 /*
2778 * ext4_ext_more_to_rm:
2779 * returns 1 if current index has to be freed (even partial)
2780 */
2781 static int
2782 ext4_ext_more_to_rm(struct ext4_ext_path *path)
2783 {
2784 BUG_ON(path->p_idx == NULL);
2785
2786 if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr))
2787 return 0;
2788
2789 /*
2790 * if truncate on deeper level happened, it wasn't partial,
2791 * so we have to consider current index for truncation
2792 */
2793 if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block)
2794 return 0;
2795 return 1;
2796 }
2797
2798 int ext4_ext_remove_space(struct inode *inode, ext4_lblk_t start,
2799 ext4_lblk_t end)
2800 {
2801 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
2802 int depth = ext_depth(inode);
2803 struct ext4_ext_path *path = NULL;
2804 long long partial_cluster = 0;
2805 handle_t *handle;
2806 int i = 0, err = 0;
2807
2808 ext_debug("truncate since %u to %u\n", start, end);
2809
2810 /* probably first extent we're gonna free will be last in block */
2811 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, depth + 1);
2812 if (IS_ERR(handle))
2813 return PTR_ERR(handle);
2814
2815 again:
2816 trace_ext4_ext_remove_space(inode, start, end, depth);
2817
2818 /*
2819 * Check if we are removing extents inside the extent tree. If that
2820 * is the case, we are going to punch a hole inside the extent tree
2821 * so we have to check whether we need to split the extent covering
2822 * the last block to remove so we can easily remove the part of it
2823 * in ext4_ext_rm_leaf().
2824 */
2825 if (end < EXT_MAX_BLOCKS - 1) {
2826 struct ext4_extent *ex;
2827 ext4_lblk_t ee_block, ex_end, lblk;
2828 ext4_fsblk_t pblk;
2829
2830 /* find extent for or closest extent to this block */
2831 path = ext4_find_extent(inode, end, NULL, EXT4_EX_NOCACHE);
2832 if (IS_ERR(path)) {
2833 ext4_journal_stop(handle);
2834 return PTR_ERR(path);
2835 }
2836 depth = ext_depth(inode);
2837 /* Leaf not may not exist only if inode has no blocks at all */
2838 ex = path[depth].p_ext;
2839 if (!ex) {
2840 if (depth) {
2841 EXT4_ERROR_INODE(inode,
2842 "path[%d].p_hdr == NULL",
2843 depth);
2844 err = -EIO;
2845 }
2846 goto out;
2847 }
2848
2849 ee_block = le32_to_cpu(ex->ee_block);
2850 ex_end = ee_block + ext4_ext_get_actual_len(ex) - 1;
2851
2852 /*
2853 * See if the last block is inside the extent, if so split
2854 * the extent at 'end' block so we can easily remove the
2855 * tail of the first part of the split extent in
2856 * ext4_ext_rm_leaf().
2857 */
2858 if (end >= ee_block && end < ex_end) {
2859
2860 /*
2861 * If we're going to split the extent, note that
2862 * the cluster containing the block after 'end' is
2863 * in use to avoid freeing it when removing blocks.
2864 */
2865 if (sbi->s_cluster_ratio > 1) {
2866 pblk = ext4_ext_pblock(ex) + end - ee_block + 2;
2867 partial_cluster =
2868 -(long long) EXT4_B2C(sbi, pblk);
2869 }
2870
2871 /*
2872 * Split the extent in two so that 'end' is the last
2873 * block in the first new extent. Also we should not
2874 * fail removing space due to ENOSPC so try to use
2875 * reserved block if that happens.
2876 */
2877 err = ext4_force_split_extent_at(handle, inode, &path,
2878 end + 1, 1);
2879 if (err < 0)
2880 goto out;
2881
2882 } else if (sbi->s_cluster_ratio > 1 && end >= ex_end) {
2883 /*
2884 * If there's an extent to the right its first cluster
2885 * contains the immediate right boundary of the
2886 * truncated/punched region. Set partial_cluster to
2887 * its negative value so it won't be freed if shared
2888 * with the current extent. The end < ee_block case
2889 * is handled in ext4_ext_rm_leaf().
2890 */
2891 lblk = ex_end + 1;
2892 err = ext4_ext_search_right(inode, path, &lblk, &pblk,
2893 &ex);
2894 if (err)
2895 goto out;
2896 if (pblk)
2897 partial_cluster =
2898 -(long long) EXT4_B2C(sbi, pblk);
2899 }
2900 }
2901 /*
2902 * We start scanning from right side, freeing all the blocks
2903 * after i_size and walking into the tree depth-wise.
2904 */
2905 depth = ext_depth(inode);
2906 if (path) {
2907 int k = i = depth;
2908 while (--k > 0)
2909 path[k].p_block =
2910 le16_to_cpu(path[k].p_hdr->eh_entries)+1;
2911 } else {
2912 path = kzalloc(sizeof(struct ext4_ext_path) * (depth + 1),
2913 GFP_NOFS);
2914 if (path == NULL) {
2915 ext4_journal_stop(handle);
2916 return -ENOMEM;
2917 }
2918 path[0].p_maxdepth = path[0].p_depth = depth;
2919 path[0].p_hdr = ext_inode_hdr(inode);
2920 i = 0;
2921
2922 if (ext4_ext_check(inode, path[0].p_hdr, depth, 0)) {
2923 err = -EIO;
2924 goto out;
2925 }
2926 }
2927 err = 0;
2928
2929 while (i >= 0 && err == 0) {
2930 if (i == depth) {
2931 /* this is leaf block */
2932 err = ext4_ext_rm_leaf(handle, inode, path,
2933 &partial_cluster, start,
2934 end);
2935 /* root level has p_bh == NULL, brelse() eats this */
2936 brelse(path[i].p_bh);
2937 path[i].p_bh = NULL;
2938 i--;
2939 continue;
2940 }
2941
2942 /* this is index block */
2943 if (!path[i].p_hdr) {
2944 ext_debug("initialize header\n");
2945 path[i].p_hdr = ext_block_hdr(path[i].p_bh);
2946 }
2947
2948 if (!path[i].p_idx) {
2949 /* this level hasn't been touched yet */
2950 path[i].p_idx = EXT_LAST_INDEX(path[i].p_hdr);
2951 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries)+1;
2952 ext_debug("init index ptr: hdr 0x%p, num %d\n",
2953 path[i].p_hdr,
2954 le16_to_cpu(path[i].p_hdr->eh_entries));
2955 } else {
2956 /* we were already here, see at next index */
2957 path[i].p_idx--;
2958 }
2959
2960 ext_debug("level %d - index, first 0x%p, cur 0x%p\n",
2961 i, EXT_FIRST_INDEX(path[i].p_hdr),
2962 path[i].p_idx);
2963 if (ext4_ext_more_to_rm(path + i)) {
2964 struct buffer_head *bh;
2965 /* go to the next level */
2966 ext_debug("move to level %d (block %llu)\n",
2967 i + 1, ext4_idx_pblock(path[i].p_idx));
2968 memset(path + i + 1, 0, sizeof(*path));
2969 bh = read_extent_tree_block(inode,
2970 ext4_idx_pblock(path[i].p_idx), depth - i - 1,
2971 EXT4_EX_NOCACHE);
2972 if (IS_ERR(bh)) {
2973 /* should we reset i_size? */
2974 err = PTR_ERR(bh);
2975 break;
2976 }
2977 /* Yield here to deal with large extent trees.
2978 * Should be a no-op if we did IO above. */
2979 cond_resched();
2980 if (WARN_ON(i + 1 > depth)) {
2981 err = -EIO;
2982 break;
2983 }
2984 path[i + 1].p_bh = bh;
2985
2986 /* save actual number of indexes since this
2987 * number is changed at the next iteration */
2988 path[i].p_block = le16_to_cpu(path[i].p_hdr->eh_entries);
2989 i++;
2990 } else {
2991 /* we finished processing this index, go up */
2992 if (path[i].p_hdr->eh_entries == 0 && i > 0) {
2993 /* index is empty, remove it;
2994 * handle must be already prepared by the
2995 * truncatei_leaf() */
2996 err = ext4_ext_rm_idx(handle, inode, path, i);
2997 }
2998 /* root level has p_bh == NULL, brelse() eats this */
2999 brelse(path[i].p_bh);
3000 path[i].p_bh = NULL;
3001 i--;
3002 ext_debug("return to level %d\n", i);
3003 }
3004 }
3005
3006 trace_ext4_ext_remove_space_done(inode, start, end, depth,
3007 partial_cluster, path->p_hdr->eh_entries);
3008
3009 /*
3010 * If we still have something in the partial cluster and we have removed
3011 * even the first extent, then we should free the blocks in the partial
3012 * cluster as well. (This code will only run when there are no leaves
3013 * to the immediate left of the truncated/punched region.)
3014 */
3015 if (partial_cluster > 0 && err == 0) {
3016 /* don't zero partial_cluster since it's not used afterwards */
3017 ext4_free_blocks(handle, inode, NULL,
3018 EXT4_C2B(sbi, partial_cluster),
3019 sbi->s_cluster_ratio,
3020 get_default_free_blocks_flags(inode));
3021 }
3022
3023 /* TODO: flexible tree reduction should be here */
3024 if (path->p_hdr->eh_entries == 0) {
3025 /*
3026 * truncate to zero freed all the tree,
3027 * so we need to correct eh_depth
3028 */
3029 err = ext4_ext_get_access(handle, inode, path);
3030 if (err == 0) {
3031 ext_inode_hdr(inode)->eh_depth = 0;
3032 ext_inode_hdr(inode)->eh_max =
3033 cpu_to_le16(ext4_ext_space_root(inode, 0));
3034 err = ext4_ext_dirty(handle, inode, path);
3035 }
3036 }
3037 out:
3038 ext4_ext_drop_refs(path);
3039 kfree(path);
3040 path = NULL;
3041 if (err == -EAGAIN)
3042 goto again;
3043 ext4_journal_stop(handle);
3044
3045 return err;
3046 }
3047
3048 /*
3049 * called at mount time
3050 */
3051 void ext4_ext_init(struct super_block *sb)
3052 {
3053 /*
3054 * possible initialization would be here
3055 */
3056
3057 if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS)) {
3058 #if defined(AGGRESSIVE_TEST) || defined(CHECK_BINSEARCH) || defined(EXTENTS_STATS)
3059 printk(KERN_INFO "EXT4-fs: file extents enabled"
3060 #ifdef AGGRESSIVE_TEST
3061 ", aggressive tests"
3062 #endif
3063 #ifdef CHECK_BINSEARCH
3064 ", check binsearch"
3065 #endif
3066 #ifdef EXTENTS_STATS
3067 ", stats"
3068 #endif
3069 "\n");
3070 #endif
3071 #ifdef EXTENTS_STATS
3072 spin_lock_init(&EXT4_SB(sb)->s_ext_stats_lock);
3073 EXT4_SB(sb)->s_ext_min = 1 << 30;
3074 EXT4_SB(sb)->s_ext_max = 0;
3075 #endif
3076 }
3077 }
3078
3079 /*
3080 * called at umount time
3081 */
3082 void ext4_ext_release(struct super_block *sb)
3083 {
3084 if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_EXTENTS))
3085 return;
3086
3087 #ifdef EXTENTS_STATS
3088 if (EXT4_SB(sb)->s_ext_blocks && EXT4_SB(sb)->s_ext_extents) {
3089 struct ext4_sb_info *sbi = EXT4_SB(sb);
3090 printk(KERN_ERR "EXT4-fs: %lu blocks in %lu extents (%lu ave)\n",
3091 sbi->s_ext_blocks, sbi->s_ext_extents,
3092 sbi->s_ext_blocks / sbi->s_ext_extents);
3093 printk(KERN_ERR "EXT4-fs: extents: %lu min, %lu max, max depth %lu\n",
3094 sbi->s_ext_min, sbi->s_ext_max, sbi->s_depth_max);
3095 }
3096 #endif
3097 }
3098
3099 static int ext4_zeroout_es(struct inode *inode, struct ext4_extent *ex)
3100 {
3101 ext4_lblk_t ee_block;
3102 ext4_fsblk_t ee_pblock;
3103 unsigned int ee_len;
3104
3105 ee_block = le32_to_cpu(ex->ee_block);
3106 ee_len = ext4_ext_get_actual_len(ex);
3107 ee_pblock = ext4_ext_pblock(ex);
3108
3109 if (ee_len == 0)
3110 return 0;
3111
3112 return ext4_es_insert_extent(inode, ee_block, ee_len, ee_pblock,
3113 EXTENT_STATUS_WRITTEN);
3114 }
3115
3116 /* FIXME!! we need to try to merge to left or right after zero-out */
3117 static int ext4_ext_zeroout(struct inode *inode, struct ext4_extent *ex)
3118 {
3119 ext4_fsblk_t ee_pblock;
3120 unsigned int ee_len;
3121 int ret;
3122
3123 ee_len = ext4_ext_get_actual_len(ex);
3124 ee_pblock = ext4_ext_pblock(ex);
3125
3126 if (ext4_encrypted_inode(inode))
3127 return ext4_encrypted_zeroout(inode, ex);
3128
3129 ret = sb_issue_zeroout(inode->i_sb, ee_pblock, ee_len, GFP_NOFS);
3130 if (ret > 0)
3131 ret = 0;
3132
3133 return ret;
3134 }
3135
3136 /*
3137 * ext4_split_extent_at() splits an extent at given block.
3138 *
3139 * @handle: the journal handle
3140 * @inode: the file inode
3141 * @path: the path to the extent
3142 * @split: the logical block where the extent is splitted.
3143 * @split_flags: indicates if the extent could be zeroout if split fails, and
3144 * the states(init or unwritten) of new extents.
3145 * @flags: flags used to insert new extent to extent tree.
3146 *
3147 *
3148 * Splits extent [a, b] into two extents [a, @split) and [@split, b], states
3149 * of which are deterimined by split_flag.
3150 *
3151 * There are two cases:
3152 * a> the extent are splitted into two extent.
3153 * b> split is not needed, and just mark the extent.
3154 *
3155 * return 0 on success.
3156 */
3157 static int ext4_split_extent_at(handle_t *handle,
3158 struct inode *inode,
3159 struct ext4_ext_path **ppath,
3160 ext4_lblk_t split,
3161 int split_flag,
3162 int flags)
3163 {
3164 struct ext4_ext_path *path = *ppath;
3165 ext4_fsblk_t newblock;
3166 ext4_lblk_t ee_block;
3167 struct ext4_extent *ex, newex, orig_ex, zero_ex;
3168 struct ext4_extent *ex2 = NULL;
3169 unsigned int ee_len, depth;
3170 int err = 0;
3171
3172 BUG_ON((split_flag & (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2)) ==
3173 (EXT4_EXT_DATA_VALID1 | EXT4_EXT_DATA_VALID2));
3174
3175 ext_debug("ext4_split_extents_at: inode %lu, logical"
3176 "block %llu\n", inode->i_ino, (unsigned long long)split);
3177
3178 ext4_ext_show_leaf(inode, path);
3179
3180 depth = ext_depth(inode);
3181 ex = path[depth].p_ext;
3182 ee_block = le32_to_cpu(ex->ee_block);
3183 ee_len = ext4_ext_get_actual_len(ex);
3184 newblock = split - ee_block + ext4_ext_pblock(ex);
3185
3186 BUG_ON(split < ee_block || split >= (ee_block + ee_len));
3187 BUG_ON(!ext4_ext_is_unwritten(ex) &&
3188 split_flag & (EXT4_EXT_MAY_ZEROOUT |
3189 EXT4_EXT_MARK_UNWRIT1 |
3190 EXT4_EXT_MARK_UNWRIT2));
3191
3192 err = ext4_ext_get_access(handle, inode, path + depth);
3193 if (err)
3194 goto out;
3195
3196 if (split == ee_block) {
3197 /*
3198 * case b: block @split is the block that the extent begins with
3199 * then we just change the state of the extent, and splitting
3200 * is not needed.
3201 */
3202 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3203 ext4_ext_mark_unwritten(ex);
3204 else
3205 ext4_ext_mark_initialized(ex);
3206
3207 if (!(flags & EXT4_GET_BLOCKS_PRE_IO))
3208 ext4_ext_try_to_merge(handle, inode, path, ex);
3209
3210 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3211 goto out;
3212 }
3213
3214 /* case a */
3215 memcpy(&orig_ex, ex, sizeof(orig_ex));
3216 ex->ee_len = cpu_to_le16(split - ee_block);
3217 if (split_flag & EXT4_EXT_MARK_UNWRIT1)
3218 ext4_ext_mark_unwritten(ex);
3219
3220 /*
3221 * path may lead to new leaf, not to original leaf any more
3222 * after ext4_ext_insert_extent() returns,
3223 */
3224 err = ext4_ext_dirty(handle, inode, path + depth);
3225 if (err)
3226 goto fix_extent_len;
3227
3228 ex2 = &newex;
3229 ex2->ee_block = cpu_to_le32(split);
3230 ex2->ee_len = cpu_to_le16(ee_len - (split - ee_block));
3231 ext4_ext_store_pblock(ex2, newblock);
3232 if (split_flag & EXT4_EXT_MARK_UNWRIT2)
3233 ext4_ext_mark_unwritten(ex2);
3234
3235 err = ext4_ext_insert_extent(handle, inode, ppath, &newex, flags);
3236 if (err == -ENOSPC && (EXT4_EXT_MAY_ZEROOUT & split_flag)) {
3237 if (split_flag & (EXT4_EXT_DATA_VALID1|EXT4_EXT_DATA_VALID2)) {
3238 if (split_flag & EXT4_EXT_DATA_VALID1) {
3239 err = ext4_ext_zeroout(inode, ex2);
3240 zero_ex.ee_block = ex2->ee_block;
3241 zero_ex.ee_len = cpu_to_le16(
3242 ext4_ext_get_actual_len(ex2));
3243 ext4_ext_store_pblock(&zero_ex,
3244 ext4_ext_pblock(ex2));
3245 } else {
3246 err = ext4_ext_zeroout(inode, ex);
3247 zero_ex.ee_block = ex->ee_block;
3248 zero_ex.ee_len = cpu_to_le16(
3249 ext4_ext_get_actual_len(ex));
3250 ext4_ext_store_pblock(&zero_ex,
3251 ext4_ext_pblock(ex));
3252 }
3253 } else {
3254 err = ext4_ext_zeroout(inode, &orig_ex);
3255 zero_ex.ee_block = orig_ex.ee_block;
3256 zero_ex.ee_len = cpu_to_le16(
3257 ext4_ext_get_actual_len(&orig_ex));
3258 ext4_ext_store_pblock(&zero_ex,
3259 ext4_ext_pblock(&orig_ex));
3260 }
3261
3262 if (err)
3263 goto fix_extent_len;
3264 /* update the extent length and mark as initialized */
3265 ex->ee_len = cpu_to_le16(ee_len);
3266 ext4_ext_try_to_merge(handle, inode, path, ex);
3267 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3268 if (err)
3269 goto fix_extent_len;
3270
3271 /* update extent status tree */
3272 err = ext4_zeroout_es(inode, &zero_ex);
3273
3274 goto out;
3275 } else if (err)
3276 goto fix_extent_len;
3277
3278 out:
3279 ext4_ext_show_leaf(inode, path);
3280 return err;
3281
3282 fix_extent_len:
3283 ex->ee_len = orig_ex.ee_len;
3284 ext4_ext_dirty(handle, inode, path + path->p_depth);
3285 return err;
3286 }
3287
3288 /*
3289 * ext4_split_extents() splits an extent and mark extent which is covered
3290 * by @map as split_flags indicates
3291 *
3292 * It may result in splitting the extent into multiple extents (up to three)
3293 * There are three possibilities:
3294 * a> There is no split required
3295 * b> Splits in two extents: Split is happening at either end of the extent
3296 * c> Splits in three extents: Somone is splitting in middle of the extent
3297 *
3298 */
3299 static int ext4_split_extent(handle_t *handle,
3300 struct inode *inode,
3301 struct ext4_ext_path **ppath,
3302 struct ext4_map_blocks *map,
3303 int split_flag,
3304 int flags)
3305 {
3306 struct ext4_ext_path *path = *ppath;
3307 ext4_lblk_t ee_block;
3308 struct ext4_extent *ex;
3309 unsigned int ee_len, depth;
3310 int err = 0;
3311 int unwritten;
3312 int split_flag1, flags1;
3313 int allocated = map->m_len;
3314
3315 depth = ext_depth(inode);
3316 ex = path[depth].p_ext;
3317 ee_block = le32_to_cpu(ex->ee_block);
3318 ee_len = ext4_ext_get_actual_len(ex);
3319 unwritten = ext4_ext_is_unwritten(ex);
3320
3321 if (map->m_lblk + map->m_len < ee_block + ee_len) {
3322 split_flag1 = split_flag & EXT4_EXT_MAY_ZEROOUT;
3323 flags1 = flags | EXT4_GET_BLOCKS_PRE_IO;
3324 if (unwritten)
3325 split_flag1 |= EXT4_EXT_MARK_UNWRIT1 |
3326 EXT4_EXT_MARK_UNWRIT2;
3327 if (split_flag & EXT4_EXT_DATA_VALID2)
3328 split_flag1 |= EXT4_EXT_DATA_VALID1;
3329 err = ext4_split_extent_at(handle, inode, ppath,
3330 map->m_lblk + map->m_len, split_flag1, flags1);
3331 if (err)
3332 goto out;
3333 } else {
3334 allocated = ee_len - (map->m_lblk - ee_block);
3335 }
3336 /*
3337 * Update path is required because previous ext4_split_extent_at() may
3338 * result in split of original leaf or extent zeroout.
3339 */
3340 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3341 if (IS_ERR(path))
3342 return PTR_ERR(path);
3343 depth = ext_depth(inode);
3344 ex = path[depth].p_ext;
3345 if (!ex) {
3346 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3347 (unsigned long) map->m_lblk);
3348 return -EIO;
3349 }
3350 unwritten = ext4_ext_is_unwritten(ex);
3351 split_flag1 = 0;
3352
3353 if (map->m_lblk >= ee_block) {
3354 split_flag1 = split_flag & EXT4_EXT_DATA_VALID2;
3355 if (unwritten) {
3356 split_flag1 |= EXT4_EXT_MARK_UNWRIT1;
3357 split_flag1 |= split_flag & (EXT4_EXT_MAY_ZEROOUT |
3358 EXT4_EXT_MARK_UNWRIT2);
3359 }
3360 err = ext4_split_extent_at(handle, inode, ppath,
3361 map->m_lblk, split_flag1, flags);
3362 if (err)
3363 goto out;
3364 }
3365
3366 ext4_ext_show_leaf(inode, path);
3367 out:
3368 return err ? err : allocated;
3369 }
3370
3371 /*
3372 * This function is called by ext4_ext_map_blocks() if someone tries to write
3373 * to an unwritten extent. It may result in splitting the unwritten
3374 * extent into multiple extents (up to three - one initialized and two
3375 * unwritten).
3376 * There are three possibilities:
3377 * a> There is no split required: Entire extent should be initialized
3378 * b> Splits in two extents: Write is happening at either end of the extent
3379 * c> Splits in three extents: Somone is writing in middle of the extent
3380 *
3381 * Pre-conditions:
3382 * - The extent pointed to by 'path' is unwritten.
3383 * - The extent pointed to by 'path' contains a superset
3384 * of the logical span [map->m_lblk, map->m_lblk + map->m_len).
3385 *
3386 * Post-conditions on success:
3387 * - the returned value is the number of blocks beyond map->l_lblk
3388 * that are allocated and initialized.
3389 * It is guaranteed to be >= map->m_len.
3390 */
3391 static int ext4_ext_convert_to_initialized(handle_t *handle,
3392 struct inode *inode,
3393 struct ext4_map_blocks *map,
3394 struct ext4_ext_path **ppath,
3395 int flags)
3396 {
3397 struct ext4_ext_path *path = *ppath;
3398 struct ext4_sb_info *sbi;
3399 struct ext4_extent_header *eh;
3400 struct ext4_map_blocks split_map;
3401 struct ext4_extent zero_ex;
3402 struct ext4_extent *ex, *abut_ex;
3403 ext4_lblk_t ee_block, eof_block;
3404 unsigned int ee_len, depth, map_len = map->m_len;
3405 int allocated = 0, max_zeroout = 0;
3406 int err = 0;
3407 int split_flag = 0;
3408
3409 ext_debug("ext4_ext_convert_to_initialized: inode %lu, logical"
3410 "block %llu, max_blocks %u\n", inode->i_ino,
3411 (unsigned long long)map->m_lblk, map_len);
3412
3413 sbi = EXT4_SB(inode->i_sb);
3414 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3415 inode->i_sb->s_blocksize_bits;
3416 if (eof_block < map->m_lblk + map_len)
3417 eof_block = map->m_lblk + map_len;
3418
3419 depth = ext_depth(inode);
3420 eh = path[depth].p_hdr;
3421 ex = path[depth].p_ext;
3422 ee_block = le32_to_cpu(ex->ee_block);
3423 ee_len = ext4_ext_get_actual_len(ex);
3424 zero_ex.ee_len = 0;
3425
3426 trace_ext4_ext_convert_to_initialized_enter(inode, map, ex);
3427
3428 /* Pre-conditions */
3429 BUG_ON(!ext4_ext_is_unwritten(ex));
3430 BUG_ON(!in_range(map->m_lblk, ee_block, ee_len));
3431
3432 /*
3433 * Attempt to transfer newly initialized blocks from the currently
3434 * unwritten extent to its neighbor. This is much cheaper
3435 * than an insertion followed by a merge as those involve costly
3436 * memmove() calls. Transferring to the left is the common case in
3437 * steady state for workloads doing fallocate(FALLOC_FL_KEEP_SIZE)
3438 * followed by append writes.
3439 *
3440 * Limitations of the current logic:
3441 * - L1: we do not deal with writes covering the whole extent.
3442 * This would require removing the extent if the transfer
3443 * is possible.
3444 * - L2: we only attempt to merge with an extent stored in the
3445 * same extent tree node.
3446 */
3447 if ((map->m_lblk == ee_block) &&
3448 /* See if we can merge left */
3449 (map_len < ee_len) && /*L1*/
3450 (ex > EXT_FIRST_EXTENT(eh))) { /*L2*/
3451 ext4_lblk_t prev_lblk;
3452 ext4_fsblk_t prev_pblk, ee_pblk;
3453 unsigned int prev_len;
3454
3455 abut_ex = ex - 1;
3456 prev_lblk = le32_to_cpu(abut_ex->ee_block);
3457 prev_len = ext4_ext_get_actual_len(abut_ex);
3458 prev_pblk = ext4_ext_pblock(abut_ex);
3459 ee_pblk = ext4_ext_pblock(ex);
3460
3461 /*
3462 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3463 * upon those conditions:
3464 * - C1: abut_ex is initialized,
3465 * - C2: abut_ex is logically abutting ex,
3466 * - C3: abut_ex is physically abutting ex,
3467 * - C4: abut_ex can receive the additional blocks without
3468 * overflowing the (initialized) length limit.
3469 */
3470 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3471 ((prev_lblk + prev_len) == ee_block) && /*C2*/
3472 ((prev_pblk + prev_len) == ee_pblk) && /*C3*/
3473 (prev_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3474 err = ext4_ext_get_access(handle, inode, path + depth);
3475 if (err)
3476 goto out;
3477
3478 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3479 map, ex, abut_ex);
3480
3481 /* Shift the start of ex by 'map_len' blocks */
3482 ex->ee_block = cpu_to_le32(ee_block + map_len);
3483 ext4_ext_store_pblock(ex, ee_pblk + map_len);
3484 ex->ee_len = cpu_to_le16(ee_len - map_len);
3485 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3486
3487 /* Extend abut_ex by 'map_len' blocks */
3488 abut_ex->ee_len = cpu_to_le16(prev_len + map_len);
3489
3490 /* Result: number of initialized blocks past m_lblk */
3491 allocated = map_len;
3492 }
3493 } else if (((map->m_lblk + map_len) == (ee_block + ee_len)) &&
3494 (map_len < ee_len) && /*L1*/
3495 ex < EXT_LAST_EXTENT(eh)) { /*L2*/
3496 /* See if we can merge right */
3497 ext4_lblk_t next_lblk;
3498 ext4_fsblk_t next_pblk, ee_pblk;
3499 unsigned int next_len;
3500
3501 abut_ex = ex + 1;
3502 next_lblk = le32_to_cpu(abut_ex->ee_block);
3503 next_len = ext4_ext_get_actual_len(abut_ex);
3504 next_pblk = ext4_ext_pblock(abut_ex);
3505 ee_pblk = ext4_ext_pblock(ex);
3506
3507 /*
3508 * A transfer of blocks from 'ex' to 'abut_ex' is allowed
3509 * upon those conditions:
3510 * - C1: abut_ex is initialized,
3511 * - C2: abut_ex is logically abutting ex,
3512 * - C3: abut_ex is physically abutting ex,
3513 * - C4: abut_ex can receive the additional blocks without
3514 * overflowing the (initialized) length limit.
3515 */
3516 if ((!ext4_ext_is_unwritten(abut_ex)) && /*C1*/
3517 ((map->m_lblk + map_len) == next_lblk) && /*C2*/
3518 ((ee_pblk + ee_len) == next_pblk) && /*C3*/
3519 (next_len < (EXT_INIT_MAX_LEN - map_len))) { /*C4*/
3520 err = ext4_ext_get_access(handle, inode, path + depth);
3521 if (err)
3522 goto out;
3523
3524 trace_ext4_ext_convert_to_initialized_fastpath(inode,
3525 map, ex, abut_ex);
3526
3527 /* Shift the start of abut_ex by 'map_len' blocks */
3528 abut_ex->ee_block = cpu_to_le32(next_lblk - map_len);
3529 ext4_ext_store_pblock(abut_ex, next_pblk - map_len);
3530 ex->ee_len = cpu_to_le16(ee_len - map_len);
3531 ext4_ext_mark_unwritten(ex); /* Restore the flag */
3532
3533 /* Extend abut_ex by 'map_len' blocks */
3534 abut_ex->ee_len = cpu_to_le16(next_len + map_len);
3535
3536 /* Result: number of initialized blocks past m_lblk */
3537 allocated = map_len;
3538 }
3539 }
3540 if (allocated) {
3541 /* Mark the block containing both extents as dirty */
3542 ext4_ext_dirty(handle, inode, path + depth);
3543
3544 /* Update path to point to the right extent */
3545 path[depth].p_ext = abut_ex;
3546 goto out;
3547 } else
3548 allocated = ee_len - (map->m_lblk - ee_block);
3549
3550 WARN_ON(map->m_lblk < ee_block);
3551 /*
3552 * It is safe to convert extent to initialized via explicit
3553 * zeroout only if extent is fully inside i_size or new_size.
3554 */
3555 split_flag |= ee_block + ee_len <= eof_block ? EXT4_EXT_MAY_ZEROOUT : 0;
3556
3557 if (EXT4_EXT_MAY_ZEROOUT & split_flag)
3558 max_zeroout = sbi->s_extent_max_zeroout_kb >>
3559 (inode->i_sb->s_blocksize_bits - 10);
3560
3561 /* If extent is less than s_max_zeroout_kb, zeroout directly */
3562 if (max_zeroout && (ee_len <= max_zeroout)) {
3563 err = ext4_ext_zeroout(inode, ex);
3564 if (err)
3565 goto out;
3566 zero_ex.ee_block = ex->ee_block;
3567 zero_ex.ee_len = cpu_to_le16(ext4_ext_get_actual_len(ex));
3568 ext4_ext_store_pblock(&zero_ex, ext4_ext_pblock(ex));
3569
3570 err = ext4_ext_get_access(handle, inode, path + depth);
3571 if (err)
3572 goto out;
3573 ext4_ext_mark_initialized(ex);
3574 ext4_ext_try_to_merge(handle, inode, path, ex);
3575 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3576 goto out;
3577 }
3578
3579 /*
3580 * four cases:
3581 * 1. split the extent into three extents.
3582 * 2. split the extent into two extents, zeroout the first half.
3583 * 3. split the extent into two extents, zeroout the second half.
3584 * 4. split the extent into two extents with out zeroout.
3585 */
3586 split_map.m_lblk = map->m_lblk;
3587 split_map.m_len = map->m_len;
3588
3589 if (max_zeroout && (allocated > map->m_len)) {
3590 if (allocated <= max_zeroout) {
3591 /* case 3 */
3592 zero_ex.ee_block =
3593 cpu_to_le32(map->m_lblk);
3594 zero_ex.ee_len = cpu_to_le16(allocated);
3595 ext4_ext_store_pblock(&zero_ex,
3596 ext4_ext_pblock(ex) + map->m_lblk - ee_block);
3597 err = ext4_ext_zeroout(inode, &zero_ex);
3598 if (err)
3599 goto out;
3600 split_map.m_lblk = map->m_lblk;
3601 split_map.m_len = allocated;
3602 } else if (map->m_lblk - ee_block + map->m_len < max_zeroout) {
3603 /* case 2 */
3604 if (map->m_lblk != ee_block) {
3605 zero_ex.ee_block = ex->ee_block;
3606 zero_ex.ee_len = cpu_to_le16(map->m_lblk -
3607 ee_block);
3608 ext4_ext_store_pblock(&zero_ex,
3609 ext4_ext_pblock(ex));
3610 err = ext4_ext_zeroout(inode, &zero_ex);
3611 if (err)
3612 goto out;
3613 }
3614
3615 split_map.m_lblk = ee_block;
3616 split_map.m_len = map->m_lblk - ee_block + map->m_len;
3617 allocated = map->m_len;
3618 }
3619 }
3620
3621 err = ext4_split_extent(handle, inode, ppath, &split_map, split_flag,
3622 flags);
3623 if (err > 0)
3624 err = 0;
3625 out:
3626 /* If we have gotten a failure, don't zero out status tree */
3627 if (!err)
3628 err = ext4_zeroout_es(inode, &zero_ex);
3629 return err ? err : allocated;
3630 }
3631
3632 /*
3633 * This function is called by ext4_ext_map_blocks() from
3634 * ext4_get_blocks_dio_write() when DIO to write
3635 * to an unwritten extent.
3636 *
3637 * Writing to an unwritten extent may result in splitting the unwritten
3638 * extent into multiple initialized/unwritten extents (up to three)
3639 * There are three possibilities:
3640 * a> There is no split required: Entire extent should be unwritten
3641 * b> Splits in two extents: Write is happening at either end of the extent
3642 * c> Splits in three extents: Somone is writing in middle of the extent
3643 *
3644 * This works the same way in the case of initialized -> unwritten conversion.
3645 *
3646 * One of more index blocks maybe needed if the extent tree grow after
3647 * the unwritten extent split. To prevent ENOSPC occur at the IO
3648 * complete, we need to split the unwritten extent before DIO submit
3649 * the IO. The unwritten extent called at this time will be split
3650 * into three unwritten extent(at most). After IO complete, the part
3651 * being filled will be convert to initialized by the end_io callback function
3652 * via ext4_convert_unwritten_extents().
3653 *
3654 * Returns the size of unwritten extent to be written on success.
3655 */
3656 static int ext4_split_convert_extents(handle_t *handle,
3657 struct inode *inode,
3658 struct ext4_map_blocks *map,
3659 struct ext4_ext_path **ppath,
3660 int flags)
3661 {
3662 struct ext4_ext_path *path = *ppath;
3663 ext4_lblk_t eof_block;
3664 ext4_lblk_t ee_block;
3665 struct ext4_extent *ex;
3666 unsigned int ee_len;
3667 int split_flag = 0, depth;
3668
3669 ext_debug("%s: inode %lu, logical block %llu, max_blocks %u\n",
3670 __func__, inode->i_ino,
3671 (unsigned long long)map->m_lblk, map->m_len);
3672
3673 eof_block = (inode->i_size + inode->i_sb->s_blocksize - 1) >>
3674 inode->i_sb->s_blocksize_bits;
3675 if (eof_block < map->m_lblk + map->m_len)
3676 eof_block = map->m_lblk + map->m_len;
3677 /*
3678 * It is safe to convert extent to initialized via explicit
3679 * zeroout only if extent is fully insde i_size or new_size.
3680 */
3681 depth = ext_depth(inode);
3682 ex = path[depth].p_ext;
3683 ee_block = le32_to_cpu(ex->ee_block);
3684 ee_len = ext4_ext_get_actual_len(ex);
3685
3686 /* Convert to unwritten */
3687 if (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN) {
3688 split_flag |= EXT4_EXT_DATA_VALID1;
3689 /* Convert to initialized */
3690 } else if (flags & EXT4_GET_BLOCKS_CONVERT) {
3691 split_flag |= ee_block + ee_len <= eof_block ?
3692 EXT4_EXT_MAY_ZEROOUT : 0;
3693 split_flag |= (EXT4_EXT_MARK_UNWRIT2 | EXT4_EXT_DATA_VALID2);
3694 }
3695 flags |= EXT4_GET_BLOCKS_PRE_IO;
3696 return ext4_split_extent(handle, inode, ppath, map, split_flag, flags);
3697 }
3698
3699 static int ext4_convert_unwritten_extents_endio(handle_t *handle,
3700 struct inode *inode,
3701 struct ext4_map_blocks *map,
3702 struct ext4_ext_path **ppath)
3703 {
3704 struct ext4_ext_path *path = *ppath;
3705 struct ext4_extent *ex;
3706 ext4_lblk_t ee_block;
3707 unsigned int ee_len;
3708 int depth;
3709 int err = 0;
3710
3711 depth = ext_depth(inode);
3712 ex = path[depth].p_ext;
3713 ee_block = le32_to_cpu(ex->ee_block);
3714 ee_len = ext4_ext_get_actual_len(ex);
3715
3716 ext_debug("ext4_convert_unwritten_extents_endio: inode %lu, logical"
3717 "block %llu, max_blocks %u\n", inode->i_ino,
3718 (unsigned long long)ee_block, ee_len);
3719
3720 /* If extent is larger than requested it is a clear sign that we still
3721 * have some extent state machine issues left. So extent_split is still
3722 * required.
3723 * TODO: Once all related issues will be fixed this situation should be
3724 * illegal.
3725 */
3726 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3727 #ifdef EXT4_DEBUG
3728 ext4_warning("Inode (%ld) finished: extent logical block %llu,"
3729 " len %u; IO logical block %llu, len %u\n",
3730 inode->i_ino, (unsigned long long)ee_block, ee_len,
3731 (unsigned long long)map->m_lblk, map->m_len);
3732 #endif
3733 err = ext4_split_convert_extents(handle, inode, map, ppath,
3734 EXT4_GET_BLOCKS_CONVERT);
3735 if (err < 0)
3736 return err;
3737 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3738 if (IS_ERR(path))
3739 return PTR_ERR(path);
3740 depth = ext_depth(inode);
3741 ex = path[depth].p_ext;
3742 }
3743
3744 err = ext4_ext_get_access(handle, inode, path + depth);
3745 if (err)
3746 goto out;
3747 /* first mark the extent as initialized */
3748 ext4_ext_mark_initialized(ex);
3749
3750 /* note: ext4_ext_correct_indexes() isn't needed here because
3751 * borders are not changed
3752 */
3753 ext4_ext_try_to_merge(handle, inode, path, ex);
3754
3755 /* Mark modified extent as dirty */
3756 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3757 out:
3758 ext4_ext_show_leaf(inode, path);
3759 return err;
3760 }
3761
3762 static void unmap_underlying_metadata_blocks(struct block_device *bdev,
3763 sector_t block, int count)
3764 {
3765 int i;
3766 for (i = 0; i < count; i++)
3767 unmap_underlying_metadata(bdev, block + i);
3768 }
3769
3770 /*
3771 * Handle EOFBLOCKS_FL flag, clearing it if necessary
3772 */
3773 static int check_eofblocks_fl(handle_t *handle, struct inode *inode,
3774 ext4_lblk_t lblk,
3775 struct ext4_ext_path *path,
3776 unsigned int len)
3777 {
3778 int i, depth;
3779 struct ext4_extent_header *eh;
3780 struct ext4_extent *last_ex;
3781
3782 if (!ext4_test_inode_flag(inode, EXT4_INODE_EOFBLOCKS))
3783 return 0;
3784
3785 depth = ext_depth(inode);
3786 eh = path[depth].p_hdr;
3787
3788 /*
3789 * We're going to remove EOFBLOCKS_FL entirely in future so we
3790 * do not care for this case anymore. Simply remove the flag
3791 * if there are no extents.
3792 */
3793 if (unlikely(!eh->eh_entries))
3794 goto out;
3795 last_ex = EXT_LAST_EXTENT(eh);
3796 /*
3797 * We should clear the EOFBLOCKS_FL flag if we are writing the
3798 * last block in the last extent in the file. We test this by
3799 * first checking to see if the caller to
3800 * ext4_ext_get_blocks() was interested in the last block (or
3801 * a block beyond the last block) in the current extent. If
3802 * this turns out to be false, we can bail out from this
3803 * function immediately.
3804 */
3805 if (lblk + len < le32_to_cpu(last_ex->ee_block) +
3806 ext4_ext_get_actual_len(last_ex))
3807 return 0;
3808 /*
3809 * If the caller does appear to be planning to write at or
3810 * beyond the end of the current extent, we then test to see
3811 * if the current extent is the last extent in the file, by
3812 * checking to make sure it was reached via the rightmost node
3813 * at each level of the tree.
3814 */
3815 for (i = depth-1; i >= 0; i--)
3816 if (path[i].p_idx != EXT_LAST_INDEX(path[i].p_hdr))
3817 return 0;
3818 out:
3819 ext4_clear_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
3820 return ext4_mark_inode_dirty(handle, inode);
3821 }
3822
3823 /**
3824 * ext4_find_delalloc_range: find delayed allocated block in the given range.
3825 *
3826 * Return 1 if there is a delalloc block in the range, otherwise 0.
3827 */
3828 int ext4_find_delalloc_range(struct inode *inode,
3829 ext4_lblk_t lblk_start,
3830 ext4_lblk_t lblk_end)
3831 {
3832 struct extent_status es;
3833
3834 ext4_es_find_delayed_extent_range(inode, lblk_start, lblk_end, &es);
3835 if (es.es_len == 0)
3836 return 0; /* there is no delay extent in this tree */
3837 else if (es.es_lblk <= lblk_start &&
3838 lblk_start < es.es_lblk + es.es_len)
3839 return 1;
3840 else if (lblk_start <= es.es_lblk && es.es_lblk <= lblk_end)
3841 return 1;
3842 else
3843 return 0;
3844 }
3845
3846 int ext4_find_delalloc_cluster(struct inode *inode, ext4_lblk_t lblk)
3847 {
3848 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3849 ext4_lblk_t lblk_start, lblk_end;
3850 lblk_start = EXT4_LBLK_CMASK(sbi, lblk);
3851 lblk_end = lblk_start + sbi->s_cluster_ratio - 1;
3852
3853 return ext4_find_delalloc_range(inode, lblk_start, lblk_end);
3854 }
3855
3856 /**
3857 * Determines how many complete clusters (out of those specified by the 'map')
3858 * are under delalloc and were reserved quota for.
3859 * This function is called when we are writing out the blocks that were
3860 * originally written with their allocation delayed, but then the space was
3861 * allocated using fallocate() before the delayed allocation could be resolved.
3862 * The cases to look for are:
3863 * ('=' indicated delayed allocated blocks
3864 * '-' indicates non-delayed allocated blocks)
3865 * (a) partial clusters towards beginning and/or end outside of allocated range
3866 * are not delalloc'ed.
3867 * Ex:
3868 * |----c---=|====c====|====c====|===-c----|
3869 * |++++++ allocated ++++++|
3870 * ==> 4 complete clusters in above example
3871 *
3872 * (b) partial cluster (outside of allocated range) towards either end is
3873 * marked for delayed allocation. In this case, we will exclude that
3874 * cluster.
3875 * Ex:
3876 * |----====c========|========c========|
3877 * |++++++ allocated ++++++|
3878 * ==> 1 complete clusters in above example
3879 *
3880 * Ex:
3881 * |================c================|
3882 * |++++++ allocated ++++++|
3883 * ==> 0 complete clusters in above example
3884 *
3885 * The ext4_da_update_reserve_space will be called only if we
3886 * determine here that there were some "entire" clusters that span
3887 * this 'allocated' range.
3888 * In the non-bigalloc case, this function will just end up returning num_blks
3889 * without ever calling ext4_find_delalloc_range.
3890 */
3891 static unsigned int
3892 get_reserved_cluster_alloc(struct inode *inode, ext4_lblk_t lblk_start,
3893 unsigned int num_blks)
3894 {
3895 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
3896 ext4_lblk_t alloc_cluster_start, alloc_cluster_end;
3897 ext4_lblk_t lblk_from, lblk_to, c_offset;
3898 unsigned int allocated_clusters = 0;
3899
3900 alloc_cluster_start = EXT4_B2C(sbi, lblk_start);
3901 alloc_cluster_end = EXT4_B2C(sbi, lblk_start + num_blks - 1);
3902
3903 /* max possible clusters for this allocation */
3904 allocated_clusters = alloc_cluster_end - alloc_cluster_start + 1;
3905
3906 trace_ext4_get_reserved_cluster_alloc(inode, lblk_start, num_blks);
3907
3908 /* Check towards left side */
3909 c_offset = EXT4_LBLK_COFF(sbi, lblk_start);
3910 if (c_offset) {
3911 lblk_from = EXT4_LBLK_CMASK(sbi, lblk_start);
3912 lblk_to = lblk_from + c_offset - 1;
3913
3914 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3915 allocated_clusters--;
3916 }
3917
3918 /* Now check towards right. */
3919 c_offset = EXT4_LBLK_COFF(sbi, lblk_start + num_blks);
3920 if (allocated_clusters && c_offset) {
3921 lblk_from = lblk_start + num_blks;
3922 lblk_to = lblk_from + (sbi->s_cluster_ratio - c_offset) - 1;
3923
3924 if (ext4_find_delalloc_range(inode, lblk_from, lblk_to))
3925 allocated_clusters--;
3926 }
3927
3928 return allocated_clusters;
3929 }
3930
3931 static int
3932 convert_initialized_extent(handle_t *handle, struct inode *inode,
3933 struct ext4_map_blocks *map,
3934 struct ext4_ext_path **ppath, int flags,
3935 unsigned int allocated, ext4_fsblk_t newblock)
3936 {
3937 struct ext4_ext_path *path = *ppath;
3938 struct ext4_extent *ex;
3939 ext4_lblk_t ee_block;
3940 unsigned int ee_len;
3941 int depth;
3942 int err = 0;
3943
3944 /*
3945 * Make sure that the extent is no bigger than we support with
3946 * unwritten extent
3947 */
3948 if (map->m_len > EXT_UNWRITTEN_MAX_LEN)
3949 map->m_len = EXT_UNWRITTEN_MAX_LEN / 2;
3950
3951 depth = ext_depth(inode);
3952 ex = path[depth].p_ext;
3953 ee_block = le32_to_cpu(ex->ee_block);
3954 ee_len = ext4_ext_get_actual_len(ex);
3955
3956 ext_debug("%s: inode %lu, logical"
3957 "block %llu, max_blocks %u\n", __func__, inode->i_ino,
3958 (unsigned long long)ee_block, ee_len);
3959
3960 if (ee_block != map->m_lblk || ee_len > map->m_len) {
3961 err = ext4_split_convert_extents(handle, inode, map, ppath,
3962 EXT4_GET_BLOCKS_CONVERT_UNWRITTEN);
3963 if (err < 0)
3964 return err;
3965 path = ext4_find_extent(inode, map->m_lblk, ppath, 0);
3966 if (IS_ERR(path))
3967 return PTR_ERR(path);
3968 depth = ext_depth(inode);
3969 ex = path[depth].p_ext;
3970 if (!ex) {
3971 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
3972 (unsigned long) map->m_lblk);
3973 return -EIO;
3974 }
3975 }
3976
3977 err = ext4_ext_get_access(handle, inode, path + depth);
3978 if (err)
3979 return err;
3980 /* first mark the extent as unwritten */
3981 ext4_ext_mark_unwritten(ex);
3982
3983 /* note: ext4_ext_correct_indexes() isn't needed here because
3984 * borders are not changed
3985 */
3986 ext4_ext_try_to_merge(handle, inode, path, ex);
3987
3988 /* Mark modified extent as dirty */
3989 err = ext4_ext_dirty(handle, inode, path + path->p_depth);
3990 if (err)
3991 return err;
3992 ext4_ext_show_leaf(inode, path);
3993
3994 ext4_update_inode_fsync_trans(handle, inode, 1);
3995 err = check_eofblocks_fl(handle, inode, map->m_lblk, path, map->m_len);
3996 if (err)
3997 return err;
3998 map->m_flags |= EXT4_MAP_UNWRITTEN;
3999 if (allocated > map->m_len)
4000 allocated = map->m_len;
4001 map->m_len = allocated;
4002 return allocated;
4003 }
4004
4005 static int
4006 ext4_ext_handle_unwritten_extents(handle_t *handle, struct inode *inode,
4007 struct ext4_map_blocks *map,
4008 struct ext4_ext_path **ppath, int flags,
4009 unsigned int allocated, ext4_fsblk_t newblock)
4010 {
4011 struct ext4_ext_path *path = *ppath;
4012 int ret = 0;
4013 int err = 0;
4014 ext4_io_end_t *io = ext4_inode_aio(inode);
4015
4016 ext_debug("ext4_ext_handle_unwritten_extents: inode %lu, logical "
4017 "block %llu, max_blocks %u, flags %x, allocated %u\n",
4018 inode->i_ino, (unsigned long long)map->m_lblk, map->m_len,
4019 flags, allocated);
4020 ext4_ext_show_leaf(inode, path);
4021
4022 /*
4023 * When writing into unwritten space, we should not fail to
4024 * allocate metadata blocks for the new extent block if needed.
4025 */
4026 flags |= EXT4_GET_BLOCKS_METADATA_NOFAIL;
4027
4028 trace_ext4_ext_handle_unwritten_extents(inode, map, flags,
4029 allocated, newblock);
4030
4031 /* get_block() before submit the IO, split the extent */
4032 if (flags & EXT4_GET_BLOCKS_PRE_IO) {
4033 ret = ext4_split_convert_extents(handle, inode, map, ppath,
4034 flags | EXT4_GET_BLOCKS_CONVERT);
4035 if (ret <= 0)
4036 goto out;
4037 /*
4038 * Flag the inode(non aio case) or end_io struct (aio case)
4039 * that this IO needs to conversion to written when IO is
4040 * completed
4041 */
4042 if (io)
4043 ext4_set_io_unwritten_flag(inode, io);
4044 else
4045 ext4_set_inode_state(inode, EXT4_STATE_DIO_UNWRITTEN);
4046 map->m_flags |= EXT4_MAP_UNWRITTEN;
4047 goto out;
4048 }
4049 /* IO end_io complete, convert the filled extent to written */
4050 if (flags & EXT4_GET_BLOCKS_CONVERT) {
4051 ret = ext4_convert_unwritten_extents_endio(handle, inode, map,
4052 ppath);
4053 if (ret >= 0) {
4054 ext4_update_inode_fsync_trans(handle, inode, 1);
4055 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4056 path, map->m_len);
4057 } else
4058 err = ret;
4059 map->m_flags |= EXT4_MAP_MAPPED;
4060 map->m_pblk = newblock;
4061 if (allocated > map->m_len)
4062 allocated = map->m_len;
4063 map->m_len = allocated;
4064 goto out2;
4065 }
4066 /* buffered IO case */
4067 /*
4068 * repeat fallocate creation request
4069 * we already have an unwritten extent
4070 */
4071 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT) {
4072 map->m_flags |= EXT4_MAP_UNWRITTEN;
4073 goto map_out;
4074 }
4075
4076 /* buffered READ or buffered write_begin() lookup */
4077 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4078 /*
4079 * We have blocks reserved already. We
4080 * return allocated blocks so that delalloc
4081 * won't do block reservation for us. But
4082 * the buffer head will be unmapped so that
4083 * a read from the block returns 0s.
4084 */
4085 map->m_flags |= EXT4_MAP_UNWRITTEN;
4086 goto out1;
4087 }
4088
4089 /* buffered write, writepage time, convert*/
4090 ret = ext4_ext_convert_to_initialized(handle, inode, map, ppath, flags);
4091 if (ret >= 0)
4092 ext4_update_inode_fsync_trans(handle, inode, 1);
4093 out:
4094 if (ret <= 0) {
4095 err = ret;
4096 goto out2;
4097 } else
4098 allocated = ret;
4099 map->m_flags |= EXT4_MAP_NEW;
4100 /*
4101 * if we allocated more blocks than requested
4102 * we need to make sure we unmap the extra block
4103 * allocated. The actual needed block will get
4104 * unmapped later when we find the buffer_head marked
4105 * new.
4106 */
4107 if (allocated > map->m_len) {
4108 unmap_underlying_metadata_blocks(inode->i_sb->s_bdev,
4109 newblock + map->m_len,
4110 allocated - map->m_len);
4111 allocated = map->m_len;
4112 }
4113 map->m_len = allocated;
4114
4115 /*
4116 * If we have done fallocate with the offset that is already
4117 * delayed allocated, we would have block reservation
4118 * and quota reservation done in the delayed write path.
4119 * But fallocate would have already updated quota and block
4120 * count for this offset. So cancel these reservation
4121 */
4122 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4123 unsigned int reserved_clusters;
4124 reserved_clusters = get_reserved_cluster_alloc(inode,
4125 map->m_lblk, map->m_len);
4126 if (reserved_clusters)
4127 ext4_da_update_reserve_space(inode,
4128 reserved_clusters,
4129 0);
4130 }
4131
4132 map_out:
4133 map->m_flags |= EXT4_MAP_MAPPED;
4134 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0) {
4135 err = check_eofblocks_fl(handle, inode, map->m_lblk, path,
4136 map->m_len);
4137 if (err < 0)
4138 goto out2;
4139 }
4140 out1:
4141 if (allocated > map->m_len)
4142 allocated = map->m_len;
4143 ext4_ext_show_leaf(inode, path);
4144 map->m_pblk = newblock;
4145 map->m_len = allocated;
4146 out2:
4147 return err ? err : allocated;
4148 }
4149
4150 /*
4151 * get_implied_cluster_alloc - check to see if the requested
4152 * allocation (in the map structure) overlaps with a cluster already
4153 * allocated in an extent.
4154 * @sb The filesystem superblock structure
4155 * @map The requested lblk->pblk mapping
4156 * @ex The extent structure which might contain an implied
4157 * cluster allocation
4158 *
4159 * This function is called by ext4_ext_map_blocks() after we failed to
4160 * find blocks that were already in the inode's extent tree. Hence,
4161 * we know that the beginning of the requested region cannot overlap
4162 * the extent from the inode's extent tree. There are three cases we
4163 * want to catch. The first is this case:
4164 *
4165 * |--- cluster # N--|
4166 * |--- extent ---| |---- requested region ---|
4167 * |==========|
4168 *
4169 * The second case that we need to test for is this one:
4170 *
4171 * |--------- cluster # N ----------------|
4172 * |--- requested region --| |------- extent ----|
4173 * |=======================|
4174 *
4175 * The third case is when the requested region lies between two extents
4176 * within the same cluster:
4177 * |------------- cluster # N-------------|
4178 * |----- ex -----| |---- ex_right ----|
4179 * |------ requested region ------|
4180 * |================|
4181 *
4182 * In each of the above cases, we need to set the map->m_pblk and
4183 * map->m_len so it corresponds to the return the extent labelled as
4184 * "|====|" from cluster #N, since it is already in use for data in
4185 * cluster EXT4_B2C(sbi, map->m_lblk). We will then return 1 to
4186 * signal to ext4_ext_map_blocks() that map->m_pblk should be treated
4187 * as a new "allocated" block region. Otherwise, we will return 0 and
4188 * ext4_ext_map_blocks() will then allocate one or more new clusters
4189 * by calling ext4_mb_new_blocks().
4190 */
4191 static int get_implied_cluster_alloc(struct super_block *sb,
4192 struct ext4_map_blocks *map,
4193 struct ext4_extent *ex,
4194 struct ext4_ext_path *path)
4195 {
4196 struct ext4_sb_info *sbi = EXT4_SB(sb);
4197 ext4_lblk_t c_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4198 ext4_lblk_t ex_cluster_start, ex_cluster_end;
4199 ext4_lblk_t rr_cluster_start;
4200 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4201 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4202 unsigned short ee_len = ext4_ext_get_actual_len(ex);
4203
4204 /* The extent passed in that we are trying to match */
4205 ex_cluster_start = EXT4_B2C(sbi, ee_block);
4206 ex_cluster_end = EXT4_B2C(sbi, ee_block + ee_len - 1);
4207
4208 /* The requested region passed into ext4_map_blocks() */
4209 rr_cluster_start = EXT4_B2C(sbi, map->m_lblk);
4210
4211 if ((rr_cluster_start == ex_cluster_end) ||
4212 (rr_cluster_start == ex_cluster_start)) {
4213 if (rr_cluster_start == ex_cluster_end)
4214 ee_start += ee_len - 1;
4215 map->m_pblk = EXT4_PBLK_CMASK(sbi, ee_start) + c_offset;
4216 map->m_len = min(map->m_len,
4217 (unsigned) sbi->s_cluster_ratio - c_offset);
4218 /*
4219 * Check for and handle this case:
4220 *
4221 * |--------- cluster # N-------------|
4222 * |------- extent ----|
4223 * |--- requested region ---|
4224 * |===========|
4225 */
4226
4227 if (map->m_lblk < ee_block)
4228 map->m_len = min(map->m_len, ee_block - map->m_lblk);
4229
4230 /*
4231 * Check for the case where there is already another allocated
4232 * block to the right of 'ex' but before the end of the cluster.
4233 *
4234 * |------------- cluster # N-------------|
4235 * |----- ex -----| |---- ex_right ----|
4236 * |------ requested region ------|
4237 * |================|
4238 */
4239 if (map->m_lblk > ee_block) {
4240 ext4_lblk_t next = ext4_ext_next_allocated_block(path);
4241 map->m_len = min(map->m_len, next - map->m_lblk);
4242 }
4243
4244 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 1);
4245 return 1;
4246 }
4247
4248 trace_ext4_get_implied_cluster_alloc_exit(sb, map, 0);
4249 return 0;
4250 }
4251
4252
4253 /*
4254 * Block allocation/map/preallocation routine for extents based files
4255 *
4256 *
4257 * Need to be called with
4258 * down_read(&EXT4_I(inode)->i_data_sem) if not allocating file system block
4259 * (ie, create is zero). Otherwise down_write(&EXT4_I(inode)->i_data_sem)
4260 *
4261 * return > 0, number of of blocks already mapped/allocated
4262 * if create == 0 and these are pre-allocated blocks
4263 * buffer head is unmapped
4264 * otherwise blocks are mapped
4265 *
4266 * return = 0, if plain look up failed (blocks have not been allocated)
4267 * buffer head is unmapped
4268 *
4269 * return < 0, error case.
4270 */
4271 int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
4272 struct ext4_map_blocks *map, int flags)
4273 {
4274 struct ext4_ext_path *path = NULL;
4275 struct ext4_extent newex, *ex, *ex2;
4276 struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
4277 ext4_fsblk_t newblock = 0;
4278 int free_on_err = 0, err = 0, depth, ret;
4279 unsigned int allocated = 0, offset = 0;
4280 unsigned int allocated_clusters = 0;
4281 struct ext4_allocation_request ar;
4282 ext4_io_end_t *io = ext4_inode_aio(inode);
4283 ext4_lblk_t cluster_offset;
4284 int set_unwritten = 0;
4285 bool map_from_cluster = false;
4286
4287 ext_debug("blocks %u/%u requested for inode %lu\n",
4288 map->m_lblk, map->m_len, inode->i_ino);
4289 trace_ext4_ext_map_blocks_enter(inode, map->m_lblk, map->m_len, flags);
4290
4291 /* find extent for this block */
4292 path = ext4_find_extent(inode, map->m_lblk, NULL, 0);
4293 if (IS_ERR(path)) {
4294 err = PTR_ERR(path);
4295 path = NULL;
4296 goto out2;
4297 }
4298
4299 depth = ext_depth(inode);
4300
4301 /*
4302 * consistent leaf must not be empty;
4303 * this situation is possible, though, _during_ tree modification;
4304 * this is why assert can't be put in ext4_find_extent()
4305 */
4306 if (unlikely(path[depth].p_ext == NULL && depth != 0)) {
4307 EXT4_ERROR_INODE(inode, "bad extent address "
4308 "lblock: %lu, depth: %d pblock %lld",
4309 (unsigned long) map->m_lblk, depth,
4310 path[depth].p_block);
4311 err = -EIO;
4312 goto out2;
4313 }
4314
4315 ex = path[depth].p_ext;
4316 if (ex) {
4317 ext4_lblk_t ee_block = le32_to_cpu(ex->ee_block);
4318 ext4_fsblk_t ee_start = ext4_ext_pblock(ex);
4319 unsigned short ee_len;
4320
4321
4322 /*
4323 * unwritten extents are treated as holes, except that
4324 * we split out initialized portions during a write.
4325 */
4326 ee_len = ext4_ext_get_actual_len(ex);
4327
4328 trace_ext4_ext_show_extent(inode, ee_block, ee_start, ee_len);
4329
4330 /* if found extent covers block, simply return it */
4331 if (in_range(map->m_lblk, ee_block, ee_len)) {
4332 newblock = map->m_lblk - ee_block + ee_start;
4333 /* number of remaining blocks in the extent */
4334 allocated = ee_len - (map->m_lblk - ee_block);
4335 ext_debug("%u fit into %u:%d -> %llu\n", map->m_lblk,
4336 ee_block, ee_len, newblock);
4337
4338 /*
4339 * If the extent is initialized check whether the
4340 * caller wants to convert it to unwritten.
4341 */
4342 if ((!ext4_ext_is_unwritten(ex)) &&
4343 (flags & EXT4_GET_BLOCKS_CONVERT_UNWRITTEN)) {
4344 allocated = convert_initialized_extent(
4345 handle, inode, map, &path,
4346 flags, allocated, newblock);
4347 goto out2;
4348 } else if (!ext4_ext_is_unwritten(ex))
4349 goto out;
4350
4351 ret = ext4_ext_handle_unwritten_extents(
4352 handle, inode, map, &path, flags,
4353 allocated, newblock);
4354 if (ret < 0)
4355 err = ret;
4356 else
4357 allocated = ret;
4358 goto out2;
4359 }
4360 }
4361
4362 /*
4363 * requested block isn't allocated yet;
4364 * we couldn't try to create block if create flag is zero
4365 */
4366 if ((flags & EXT4_GET_BLOCKS_CREATE) == 0) {
4367 /*
4368 * put just found gap into cache to speed up
4369 * subsequent requests
4370 */
4371 ext4_ext_put_gap_in_cache(inode, path, map->m_lblk);
4372 goto out2;
4373 }
4374
4375 /*
4376 * Okay, we need to do block allocation.
4377 */
4378 newex.ee_block = cpu_to_le32(map->m_lblk);
4379 cluster_offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4380
4381 /*
4382 * If we are doing bigalloc, check to see if the extent returned
4383 * by ext4_find_extent() implies a cluster we can use.
4384 */
4385 if (cluster_offset && ex &&
4386 get_implied_cluster_alloc(inode->i_sb, map, ex, path)) {
4387 ar.len = allocated = map->m_len;
4388 newblock = map->m_pblk;
4389 map_from_cluster = true;
4390 goto got_allocated_blocks;
4391 }
4392
4393 /* find neighbour allocated blocks */
4394 ar.lleft = map->m_lblk;
4395 err = ext4_ext_search_left(inode, path, &ar.lleft, &ar.pleft);
4396 if (err)
4397 goto out2;
4398 ar.lright = map->m_lblk;
4399 ex2 = NULL;
4400 err = ext4_ext_search_right(inode, path, &ar.lright, &ar.pright, &ex2);
4401 if (err)
4402 goto out2;
4403
4404 /* Check if the extent after searching to the right implies a
4405 * cluster we can use. */
4406 if ((sbi->s_cluster_ratio > 1) && ex2 &&
4407 get_implied_cluster_alloc(inode->i_sb, map, ex2, path)) {
4408 ar.len = allocated = map->m_len;
4409 newblock = map->m_pblk;
4410 map_from_cluster = true;
4411 goto got_allocated_blocks;
4412 }
4413
4414 /*
4415 * See if request is beyond maximum number of blocks we can have in
4416 * a single extent. For an initialized extent this limit is
4417 * EXT_INIT_MAX_LEN and for an unwritten extent this limit is
4418 * EXT_UNWRITTEN_MAX_LEN.
4419 */
4420 if (map->m_len > EXT_INIT_MAX_LEN &&
4421 !(flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4422 map->m_len = EXT_INIT_MAX_LEN;
4423 else if (map->m_len > EXT_UNWRITTEN_MAX_LEN &&
4424 (flags & EXT4_GET_BLOCKS_UNWRIT_EXT))
4425 map->m_len = EXT_UNWRITTEN_MAX_LEN;
4426
4427 /* Check if we can really insert (m_lblk)::(m_lblk + m_len) extent */
4428 newex.ee_len = cpu_to_le16(map->m_len);
4429 err = ext4_ext_check_overlap(sbi, inode, &newex, path);
4430 if (err)
4431 allocated = ext4_ext_get_actual_len(&newex);
4432 else
4433 allocated = map->m_len;
4434
4435 /* allocate new block */
4436 ar.inode = inode;
4437 ar.goal = ext4_ext_find_goal(inode, path, map->m_lblk);
4438 ar.logical = map->m_lblk;
4439 /*
4440 * We calculate the offset from the beginning of the cluster
4441 * for the logical block number, since when we allocate a
4442 * physical cluster, the physical block should start at the
4443 * same offset from the beginning of the cluster. This is
4444 * needed so that future calls to get_implied_cluster_alloc()
4445 * work correctly.
4446 */
4447 offset = EXT4_LBLK_COFF(sbi, map->m_lblk);
4448 ar.len = EXT4_NUM_B2C(sbi, offset+allocated);
4449 ar.goal -= offset;
4450 ar.logical -= offset;
4451 if (S_ISREG(inode->i_mode))
4452 ar.flags = EXT4_MB_HINT_DATA;
4453 else
4454 /* disable in-core preallocation for non-regular files */
4455 ar.flags = 0;
4456 if (flags & EXT4_GET_BLOCKS_NO_NORMALIZE)
4457 ar.flags |= EXT4_MB_HINT_NOPREALLOC;
4458 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
4459 ar.flags |= EXT4_MB_DELALLOC_RESERVED;
4460 if (flags & EXT4_GET_BLOCKS_METADATA_NOFAIL)
4461 ar.flags |= EXT4_MB_USE_RESERVED;
4462 newblock = ext4_mb_new_blocks(handle, &ar, &err);
4463 if (!newblock)
4464 goto out2;
4465 ext_debug("allocate new block: goal %llu, found %llu/%u\n",
4466 ar.goal, newblock, allocated);
4467 free_on_err = 1;
4468 allocated_clusters = ar.len;
4469 ar.len = EXT4_C2B(sbi, ar.len) - offset;
4470 if (ar.len > allocated)
4471 ar.len = allocated;
4472
4473 got_allocated_blocks:
4474 /* try to insert new extent into found leaf and return */
4475 ext4_ext_store_pblock(&newex, newblock + offset);
4476 newex.ee_len = cpu_to_le16(ar.len);
4477 /* Mark unwritten */
4478 if (flags & EXT4_GET_BLOCKS_UNWRIT_EXT){
4479 ext4_ext_mark_unwritten(&newex);
4480 map->m_flags |= EXT4_MAP_UNWRITTEN;
4481 /*
4482 * io_end structure was created for every IO write to an
4483 * unwritten extent. To avoid unnecessary conversion,
4484 * here we flag the IO that really needs the conversion.
4485 * For non asycn direct IO case, flag the inode state
4486 * that we need to perform conversion when IO is done.
4487 */
4488 if (flags & EXT4_GET_BLOCKS_PRE_IO)
4489 set_unwritten = 1;
4490 }
4491
4492 err = 0;
4493 if ((flags & EXT4_GET_BLOCKS_KEEP_SIZE) == 0)
4494 err = check_eofblocks_fl(handle, inode, map->m_lblk,
4495 path, ar.len);
4496 if (!err)
4497 err = ext4_ext_insert_extent(handle, inode, &path,
4498 &newex, flags);
4499
4500 if (!err && set_unwritten) {
4501 if (io)
4502 ext4_set_io_unwritten_flag(inode, io);
4503 else
4504 ext4_set_inode_state(inode,
4505 EXT4_STATE_DIO_UNWRITTEN);
4506 }
4507
4508 if (err && free_on_err) {
4509 int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
4510 EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
4511 /* free data blocks we just allocated */
4512 /* not a good idea to call discard here directly,
4513 * but otherwise we'd need to call it every free() */
4514 ext4_discard_preallocations(inode);
4515 ext4_free_blocks(handle, inode, NULL, newblock,
4516 EXT4_C2B(sbi, allocated_clusters), fb_flags);
4517 goto out2;
4518 }
4519
4520 /* previous routine could use block we allocated */
4521 newblock = ext4_ext_pblock(&newex);
4522 allocated = ext4_ext_get_actual_len(&newex);
4523 if (allocated > map->m_len)
4524 allocated = map->m_len;
4525 map->m_flags |= EXT4_MAP_NEW;
4526
4527 /*
4528 * Update reserved blocks/metadata blocks after successful
4529 * block allocation which had been deferred till now.
4530 */
4531 if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE) {
4532 unsigned int reserved_clusters;
4533 /*
4534 * Check how many clusters we had reserved this allocated range
4535 */
4536 reserved_clusters = get_reserved_cluster_alloc(inode,
4537 map->m_lblk, allocated);
4538 if (!map_from_cluster) {
4539 BUG_ON(allocated_clusters < reserved_clusters);
4540 if (reserved_clusters < allocated_clusters) {
4541 struct ext4_inode_info *ei = EXT4_I(inode);
4542 int reservation = allocated_clusters -
4543 reserved_clusters;
4544 /*
4545 * It seems we claimed few clusters outside of
4546 * the range of this allocation. We should give
4547 * it back to the reservation pool. This can
4548 * happen in the following case:
4549 *
4550 * * Suppose s_cluster_ratio is 4 (i.e., each
4551 * cluster has 4 blocks. Thus, the clusters
4552 * are [0-3],[4-7],[8-11]...
4553 * * First comes delayed allocation write for
4554 * logical blocks 10 & 11. Since there were no
4555 * previous delayed allocated blocks in the
4556 * range [8-11], we would reserve 1 cluster
4557 * for this write.
4558 * * Next comes write for logical blocks 3 to 8.
4559 * In this case, we will reserve 2 clusters
4560 * (for [0-3] and [4-7]; and not for [8-11] as
4561 * that range has a delayed allocated blocks.
4562 * Thus total reserved clusters now becomes 3.
4563 * * Now, during the delayed allocation writeout
4564 * time, we will first write blocks [3-8] and
4565 * allocate 3 clusters for writing these
4566 * blocks. Also, we would claim all these
4567 * three clusters above.
4568 * * Now when we come here to writeout the
4569 * blocks [10-11], we would expect to claim
4570 * the reservation of 1 cluster we had made
4571 * (and we would claim it since there are no
4572 * more delayed allocated blocks in the range
4573 * [8-11]. But our reserved cluster count had
4574 * already gone to 0.
4575 *
4576 * Thus, at the step 4 above when we determine
4577 * that there are still some unwritten delayed
4578 * allocated blocks outside of our current
4579 * block range, we should increment the
4580 * reserved clusters count so that when the
4581 * remaining blocks finally gets written, we
4582 * could claim them.
4583 */
4584 dquot_reserve_block(inode,
4585 EXT4_C2B(sbi, reservation));
4586 spin_lock(&ei->i_block_reservation_lock);
4587 ei->i_reserved_data_blocks += reservation;
4588 spin_unlock(&ei->i_block_reservation_lock);
4589 }
4590 /*
4591 * We will claim quota for all newly allocated blocks.
4592 * We're updating the reserved space *after* the
4593 * correction above so we do not accidentally free
4594 * all the metadata reservation because we might
4595 * actually need it later on.
4596 */
4597 ext4_da_update_reserve_space(inode, allocated_clusters,
4598 1);
4599 }
4600 }
4601
4602 /*
4603 * Cache the extent and update transaction to commit on fdatasync only
4604 * when it is _not_ an unwritten extent.
4605 */
4606 if ((flags & EXT4_GET_BLOCKS_UNWRIT_EXT) == 0)
4607 ext4_update_inode_fsync_trans(handle, inode, 1);
4608 else
4609 ext4_update_inode_fsync_trans(handle, inode, 0);
4610 out:
4611 if (allocated > map->m_len)
4612 allocated = map->m_len;
4613 ext4_ext_show_leaf(inode, path);
4614 map->m_flags |= EXT4_MAP_MAPPED;
4615 map->m_pblk = newblock;
4616 map->m_len = allocated;
4617 out2:
4618 ext4_ext_drop_refs(path);
4619 kfree(path);
4620
4621 trace_ext4_ext_map_blocks_exit(inode, flags, map,
4622 err ? err : allocated);
4623 return err ? err : allocated;
4624 }
4625
4626 void ext4_ext_truncate(handle_t *handle, struct inode *inode)
4627 {
4628 struct super_block *sb = inode->i_sb;
4629 ext4_lblk_t last_block;
4630 int err = 0;
4631
4632 /*
4633 * TODO: optimization is possible here.
4634 * Probably we need not scan at all,
4635 * because page truncation is enough.
4636 */
4637
4638 /* we have to know where to truncate from in crash case */
4639 EXT4_I(inode)->i_disksize = inode->i_size;
4640 ext4_mark_inode_dirty(handle, inode);
4641
4642 last_block = (inode->i_size + sb->s_blocksize - 1)
4643 >> EXT4_BLOCK_SIZE_BITS(sb);
4644 retry:
4645 err = ext4_es_remove_extent(inode, last_block,
4646 EXT_MAX_BLOCKS - last_block);
4647 if (err == -ENOMEM) {
4648 cond_resched();
4649 congestion_wait(BLK_RW_ASYNC, HZ/50);
4650 goto retry;
4651 }
4652 if (err) {
4653 ext4_std_error(inode->i_sb, err);
4654 return;
4655 }
4656 err = ext4_ext_remove_space(inode, last_block, EXT_MAX_BLOCKS - 1);
4657 ext4_std_error(inode->i_sb, err);
4658 }
4659
4660 static int ext4_alloc_file_blocks(struct file *file, ext4_lblk_t offset,
4661 ext4_lblk_t len, loff_t new_size,
4662 int flags, int mode)
4663 {
4664 struct inode *inode = file_inode(file);
4665 handle_t *handle;
4666 int ret = 0;
4667 int ret2 = 0;
4668 int retries = 0;
4669 int depth = 0;
4670 struct ext4_map_blocks map;
4671 unsigned int credits;
4672 loff_t epos;
4673
4674 map.m_lblk = offset;
4675 map.m_len = len;
4676 /*
4677 * Don't normalize the request if it can fit in one extent so
4678 * that it doesn't get unnecessarily split into multiple
4679 * extents.
4680 */
4681 if (len <= EXT_UNWRITTEN_MAX_LEN)
4682 flags |= EXT4_GET_BLOCKS_NO_NORMALIZE;
4683
4684 /* Wait all existing dio workers, newcomers will block on i_mutex */
4685 ext4_inode_block_unlocked_dio(inode);
4686 inode_dio_wait(inode);
4687
4688 /*
4689 * credits to insert 1 extent into extent tree
4690 */
4691 credits = ext4_chunk_trans_blocks(inode, len);
4692 /*
4693 * We can only call ext_depth() on extent based inodes
4694 */
4695 if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
4696 depth = ext_depth(inode);
4697 else
4698 depth = -1;
4699
4700 retry:
4701 while (ret >= 0 && len) {
4702 /*
4703 * Recalculate credits when extent tree depth changes.
4704 */
4705 if (depth >= 0 && depth != ext_depth(inode)) {
4706 credits = ext4_chunk_trans_blocks(inode, len);
4707 depth = ext_depth(inode);
4708 }
4709
4710 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
4711 credits);
4712 if (IS_ERR(handle)) {
4713 ret = PTR_ERR(handle);
4714 break;
4715 }
4716 ret = ext4_map_blocks(handle, inode, &map, flags);
4717 if (ret <= 0) {
4718 ext4_debug("inode #%lu: block %u: len %u: "
4719 "ext4_ext_map_blocks returned %d",
4720 inode->i_ino, map.m_lblk,
4721 map.m_len, ret);
4722 ext4_mark_inode_dirty(handle, inode);
4723 ret2 = ext4_journal_stop(handle);
4724 break;
4725 }
4726 map.m_lblk += ret;
4727 map.m_len = len = len - ret;
4728 epos = (loff_t)map.m_lblk << inode->i_blkbits;
4729 inode->i_ctime = ext4_current_time(inode);
4730 if (new_size) {
4731 if (epos > new_size)
4732 epos = new_size;
4733 if (ext4_update_inode_size(inode, epos) & 0x1)
4734 inode->i_mtime = inode->i_ctime;
4735 } else {
4736 if (epos > inode->i_size)
4737 ext4_set_inode_flag(inode,
4738 EXT4_INODE_EOFBLOCKS);
4739 }
4740 ext4_mark_inode_dirty(handle, inode);
4741 ret2 = ext4_journal_stop(handle);
4742 if (ret2)
4743 break;
4744 }
4745 if (ret == -ENOSPC &&
4746 ext4_should_retry_alloc(inode->i_sb, &retries)) {
4747 ret = 0;
4748 goto retry;
4749 }
4750
4751 ext4_inode_resume_unlocked_dio(inode);
4752
4753 return ret > 0 ? ret2 : ret;
4754 }
4755
4756 static long ext4_zero_range(struct file *file, loff_t offset,
4757 loff_t len, int mode)
4758 {
4759 struct inode *inode = file_inode(file);
4760 handle_t *handle = NULL;
4761 unsigned int max_blocks;
4762 loff_t new_size = 0;
4763 int ret = 0;
4764 int flags;
4765 int credits;
4766 int partial_begin, partial_end;
4767 loff_t start, end;
4768 ext4_lblk_t lblk;
4769 struct address_space *mapping = inode->i_mapping;
4770 unsigned int blkbits = inode->i_blkbits;
4771
4772 trace_ext4_zero_range(inode, offset, len, mode);
4773
4774 if (!S_ISREG(inode->i_mode))
4775 return -EINVAL;
4776
4777 /* Call ext4_force_commit to flush all data in case of data=journal. */
4778 if (ext4_should_journal_data(inode)) {
4779 ret = ext4_force_commit(inode->i_sb);
4780 if (ret)
4781 return ret;
4782 }
4783
4784 /*
4785 * Write out all dirty pages to avoid race conditions
4786 * Then release them.
4787 */
4788 if (mapping->nrpages && mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
4789 ret = filemap_write_and_wait_range(mapping, offset,
4790 offset + len - 1);
4791 if (ret)
4792 return ret;
4793 }
4794
4795 /*
4796 * Round up offset. This is not fallocate, we neet to zero out
4797 * blocks, so convert interior block aligned part of the range to
4798 * unwritten and possibly manually zero out unaligned parts of the
4799 * range.
4800 */
4801 start = round_up(offset, 1 << blkbits);
4802 end = round_down((offset + len), 1 << blkbits);
4803
4804 if (start < offset || end > offset + len)
4805 return -EINVAL;
4806 partial_begin = offset & ((1 << blkbits) - 1);
4807 partial_end = (offset + len) & ((1 << blkbits) - 1);
4808
4809 lblk = start >> blkbits;
4810 max_blocks = (end >> blkbits);
4811 if (max_blocks < lblk)
4812 max_blocks = 0;
4813 else
4814 max_blocks -= lblk;
4815
4816 mutex_lock(&inode->i_mutex);
4817
4818 /*
4819 * Indirect files do not support unwritten extnets
4820 */
4821 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4822 ret = -EOPNOTSUPP;
4823 goto out_mutex;
4824 }
4825
4826 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4827 offset + len > i_size_read(inode)) {
4828 new_size = offset + len;
4829 ret = inode_newsize_ok(inode, new_size);
4830 if (ret)
4831 goto out_mutex;
4832 }
4833
4834 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4835 if (mode & FALLOC_FL_KEEP_SIZE)
4836 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4837
4838 /* Preallocate the range including the unaligned edges */
4839 if (partial_begin || partial_end) {
4840 ret = ext4_alloc_file_blocks(file,
4841 round_down(offset, 1 << blkbits) >> blkbits,
4842 (round_up((offset + len), 1 << blkbits) -
4843 round_down(offset, 1 << blkbits)) >> blkbits,
4844 new_size, flags, mode);
4845 if (ret)
4846 goto out_mutex;
4847
4848 }
4849
4850 /* Zero range excluding the unaligned edges */
4851 if (max_blocks > 0) {
4852 flags |= (EXT4_GET_BLOCKS_CONVERT_UNWRITTEN |
4853 EXT4_EX_NOCACHE);
4854
4855 /* Now release the pages and zero block aligned part of pages*/
4856 truncate_pagecache_range(inode, start, end - 1);
4857 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4858
4859 /* Wait all existing dio workers, newcomers will block on i_mutex */
4860 ext4_inode_block_unlocked_dio(inode);
4861 inode_dio_wait(inode);
4862
4863 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4864 flags, mode);
4865 if (ret)
4866 goto out_dio;
4867 }
4868 if (!partial_begin && !partial_end)
4869 goto out_dio;
4870
4871 /*
4872 * In worst case we have to writeout two nonadjacent unwritten
4873 * blocks and update the inode
4874 */
4875 credits = (2 * ext4_ext_index_trans_blocks(inode, 2)) + 1;
4876 if (ext4_should_journal_data(inode))
4877 credits += 2;
4878 handle = ext4_journal_start(inode, EXT4_HT_MISC, credits);
4879 if (IS_ERR(handle)) {
4880 ret = PTR_ERR(handle);
4881 ext4_std_error(inode->i_sb, ret);
4882 goto out_dio;
4883 }
4884
4885 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
4886 if (new_size) {
4887 ext4_update_inode_size(inode, new_size);
4888 } else {
4889 /*
4890 * Mark that we allocate beyond EOF so the subsequent truncate
4891 * can proceed even if the new size is the same as i_size.
4892 */
4893 if ((offset + len) > i_size_read(inode))
4894 ext4_set_inode_flag(inode, EXT4_INODE_EOFBLOCKS);
4895 }
4896 ext4_mark_inode_dirty(handle, inode);
4897
4898 /* Zero out partial block at the edges of the range */
4899 ret = ext4_zero_partial_blocks(handle, inode, offset, len);
4900
4901 if (file->f_flags & O_SYNC)
4902 ext4_handle_sync(handle);
4903
4904 ext4_journal_stop(handle);
4905 out_dio:
4906 ext4_inode_resume_unlocked_dio(inode);
4907 out_mutex:
4908 mutex_unlock(&inode->i_mutex);
4909 return ret;
4910 }
4911
4912 /*
4913 * preallocate space for a file. This implements ext4's fallocate file
4914 * operation, which gets called from sys_fallocate system call.
4915 * For block-mapped files, posix_fallocate should fall back to the method
4916 * of writing zeroes to the required new blocks (the same behavior which is
4917 * expected for file systems which do not support fallocate() system call).
4918 */
4919 long ext4_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
4920 {
4921 struct inode *inode = file_inode(file);
4922 loff_t new_size = 0;
4923 unsigned int max_blocks;
4924 int ret = 0;
4925 int flags;
4926 ext4_lblk_t lblk;
4927 unsigned int blkbits = inode->i_blkbits;
4928
4929 /*
4930 * Encrypted inodes can't handle collapse range or insert
4931 * range since we would need to re-encrypt blocks with a
4932 * different IV or XTS tweak (which are based on the logical
4933 * block number).
4934 *
4935 * XXX It's not clear why zero range isn't working, but we'll
4936 * leave it disabled for encrypted inodes for now. This is a
4937 * bug we should fix....
4938 */
4939 if (ext4_encrypted_inode(inode) &&
4940 (mode & (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE |
4941 FALLOC_FL_ZERO_RANGE)))
4942 return -EOPNOTSUPP;
4943
4944 /* Return error if mode is not supported */
4945 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
4946 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE |
4947 FALLOC_FL_INSERT_RANGE))
4948 return -EOPNOTSUPP;
4949
4950 if (mode & FALLOC_FL_PUNCH_HOLE)
4951 return ext4_punch_hole(inode, offset, len);
4952
4953 ret = ext4_convert_inline_data(inode);
4954 if (ret)
4955 return ret;
4956
4957 if (mode & FALLOC_FL_COLLAPSE_RANGE)
4958 return ext4_collapse_range(inode, offset, len);
4959
4960 if (mode & FALLOC_FL_INSERT_RANGE)
4961 return ext4_insert_range(inode, offset, len);
4962
4963 if (mode & FALLOC_FL_ZERO_RANGE)
4964 return ext4_zero_range(file, offset, len, mode);
4965
4966 trace_ext4_fallocate_enter(inode, offset, len, mode);
4967 lblk = offset >> blkbits;
4968 /*
4969 * We can't just convert len to max_blocks because
4970 * If blocksize = 4096 offset = 3072 and len = 2048
4971 */
4972 max_blocks = (EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits)
4973 - lblk;
4974
4975 flags = EXT4_GET_BLOCKS_CREATE_UNWRIT_EXT;
4976 if (mode & FALLOC_FL_KEEP_SIZE)
4977 flags |= EXT4_GET_BLOCKS_KEEP_SIZE;
4978
4979 mutex_lock(&inode->i_mutex);
4980
4981 /*
4982 * We only support preallocation for extent-based files only
4983 */
4984 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
4985 ret = -EOPNOTSUPP;
4986 goto out;
4987 }
4988
4989 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
4990 offset + len > i_size_read(inode)) {
4991 new_size = offset + len;
4992 ret = inode_newsize_ok(inode, new_size);
4993 if (ret)
4994 goto out;
4995 }
4996
4997 ret = ext4_alloc_file_blocks(file, lblk, max_blocks, new_size,
4998 flags, mode);
4999 if (ret)
5000 goto out;
5001
5002 if (file->f_flags & O_SYNC && EXT4_SB(inode->i_sb)->s_journal) {
5003 ret = jbd2_complete_transaction(EXT4_SB(inode->i_sb)->s_journal,
5004 EXT4_I(inode)->i_sync_tid);
5005 }
5006 out:
5007 mutex_unlock(&inode->i_mutex);
5008 trace_ext4_fallocate_exit(inode, offset, max_blocks, ret);
5009 return ret;
5010 }
5011
5012 /*
5013 * This function convert a range of blocks to written extents
5014 * The caller of this function will pass the start offset and the size.
5015 * all unwritten extents within this range will be converted to
5016 * written extents.
5017 *
5018 * This function is called from the direct IO end io call back
5019 * function, to convert the fallocated extents after IO is completed.
5020 * Returns 0 on success.
5021 */
5022 int ext4_convert_unwritten_extents(handle_t *handle, struct inode *inode,
5023 loff_t offset, ssize_t len)
5024 {
5025 unsigned int max_blocks;
5026 int ret = 0;
5027 int ret2 = 0;
5028 struct ext4_map_blocks map;
5029 unsigned int credits, blkbits = inode->i_blkbits;
5030
5031 map.m_lblk = offset >> blkbits;
5032 /*
5033 * We can't just convert len to max_blocks because
5034 * If blocksize = 4096 offset = 3072 and len = 2048
5035 */
5036 max_blocks = ((EXT4_BLOCK_ALIGN(len + offset, blkbits) >> blkbits) -
5037 map.m_lblk);
5038 /*
5039 * This is somewhat ugly but the idea is clear: When transaction is
5040 * reserved, everything goes into it. Otherwise we rather start several
5041 * smaller transactions for conversion of each extent separately.
5042 */
5043 if (handle) {
5044 handle = ext4_journal_start_reserved(handle,
5045 EXT4_HT_EXT_CONVERT);
5046 if (IS_ERR(handle))
5047 return PTR_ERR(handle);
5048 credits = 0;
5049 } else {
5050 /*
5051 * credits to insert 1 extent into extent tree
5052 */
5053 credits = ext4_chunk_trans_blocks(inode, max_blocks);
5054 }
5055 while (ret >= 0 && ret < max_blocks) {
5056 map.m_lblk += ret;
5057 map.m_len = (max_blocks -= ret);
5058 if (credits) {
5059 handle = ext4_journal_start(inode, EXT4_HT_MAP_BLOCKS,
5060 credits);
5061 if (IS_ERR(handle)) {
5062 ret = PTR_ERR(handle);
5063 break;
5064 }
5065 }
5066 ret = ext4_map_blocks(handle, inode, &map,
5067 EXT4_GET_BLOCKS_IO_CONVERT_EXT);
5068 if (ret <= 0)
5069 ext4_warning(inode->i_sb,
5070 "inode #%lu: block %u: len %u: "
5071 "ext4_ext_map_blocks returned %d",
5072 inode->i_ino, map.m_lblk,
5073 map.m_len, ret);
5074 ext4_mark_inode_dirty(handle, inode);
5075 if (credits)
5076 ret2 = ext4_journal_stop(handle);
5077 if (ret <= 0 || ret2)
5078 break;
5079 }
5080 if (!credits)
5081 ret2 = ext4_journal_stop(handle);
5082 return ret > 0 ? ret2 : ret;
5083 }
5084
5085 /*
5086 * If newes is not existing extent (newes->ec_pblk equals zero) find
5087 * delayed extent at start of newes and update newes accordingly and
5088 * return start of the next delayed extent.
5089 *
5090 * If newes is existing extent (newes->ec_pblk is not equal zero)
5091 * return start of next delayed extent or EXT_MAX_BLOCKS if no delayed
5092 * extent found. Leave newes unmodified.
5093 */
5094 static int ext4_find_delayed_extent(struct inode *inode,
5095 struct extent_status *newes)
5096 {
5097 struct extent_status es;
5098 ext4_lblk_t block, next_del;
5099
5100 if (newes->es_pblk == 0) {
5101 ext4_es_find_delayed_extent_range(inode, newes->es_lblk,
5102 newes->es_lblk + newes->es_len - 1, &es);
5103
5104 /*
5105 * No extent in extent-tree contains block @newes->es_pblk,
5106 * then the block may stay in 1)a hole or 2)delayed-extent.
5107 */
5108 if (es.es_len == 0)
5109 /* A hole found. */
5110 return 0;
5111
5112 if (es.es_lblk > newes->es_lblk) {
5113 /* A hole found. */
5114 newes->es_len = min(es.es_lblk - newes->es_lblk,
5115 newes->es_len);
5116 return 0;
5117 }
5118
5119 newes->es_len = es.es_lblk + es.es_len - newes->es_lblk;
5120 }
5121
5122 block = newes->es_lblk + newes->es_len;
5123 ext4_es_find_delayed_extent_range(inode, block, EXT_MAX_BLOCKS, &es);
5124 if (es.es_len == 0)
5125 next_del = EXT_MAX_BLOCKS;
5126 else
5127 next_del = es.es_lblk;
5128
5129 return next_del;
5130 }
5131 /* fiemap flags we can handle specified here */
5132 #define EXT4_FIEMAP_FLAGS (FIEMAP_FLAG_SYNC|FIEMAP_FLAG_XATTR)
5133
5134 static int ext4_xattr_fiemap(struct inode *inode,
5135 struct fiemap_extent_info *fieinfo)
5136 {
5137 __u64 physical = 0;
5138 __u64 length;
5139 __u32 flags = FIEMAP_EXTENT_LAST;
5140 int blockbits = inode->i_sb->s_blocksize_bits;
5141 int error = 0;
5142
5143 /* in-inode? */
5144 if (ext4_test_inode_state(inode, EXT4_STATE_XATTR)) {
5145 struct ext4_iloc iloc;
5146 int offset; /* offset of xattr in inode */
5147
5148 error = ext4_get_inode_loc(inode, &iloc);
5149 if (error)
5150 return error;
5151 physical = (__u64)iloc.bh->b_blocknr << blockbits;
5152 offset = EXT4_GOOD_OLD_INODE_SIZE +
5153 EXT4_I(inode)->i_extra_isize;
5154 physical += offset;
5155 length = EXT4_SB(inode->i_sb)->s_inode_size - offset;
5156 flags |= FIEMAP_EXTENT_DATA_INLINE;
5157 brelse(iloc.bh);
5158 } else { /* external block */
5159 physical = (__u64)EXT4_I(inode)->i_file_acl << blockbits;
5160 length = inode->i_sb->s_blocksize;
5161 }
5162
5163 if (physical)
5164 error = fiemap_fill_next_extent(fieinfo, 0, physical,
5165 length, flags);
5166 return (error < 0 ? error : 0);
5167 }
5168
5169 int ext4_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
5170 __u64 start, __u64 len)
5171 {
5172 ext4_lblk_t start_blk;
5173 int error = 0;
5174
5175 if (ext4_has_inline_data(inode)) {
5176 int has_inline = 1;
5177
5178 error = ext4_inline_data_fiemap(inode, fieinfo, &has_inline,
5179 start, len);
5180
5181 if (has_inline)
5182 return error;
5183 }
5184
5185 if (fieinfo->fi_flags & FIEMAP_FLAG_CACHE) {
5186 error = ext4_ext_precache(inode);
5187 if (error)
5188 return error;
5189 }
5190
5191 /* fallback to generic here if not in extents fmt */
5192 if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
5193 return generic_block_fiemap(inode, fieinfo, start, len,
5194 ext4_get_block);
5195
5196 if (fiemap_check_flags(fieinfo, EXT4_FIEMAP_FLAGS))
5197 return -EBADR;
5198
5199 if (fieinfo->fi_flags & FIEMAP_FLAG_XATTR) {
5200 error = ext4_xattr_fiemap(inode, fieinfo);
5201 } else {
5202 ext4_lblk_t len_blks;
5203 __u64 last_blk;
5204
5205 start_blk = start >> inode->i_sb->s_blocksize_bits;
5206 last_blk = (start + len - 1) >> inode->i_sb->s_blocksize_bits;
5207 if (last_blk >= EXT_MAX_BLOCKS)
5208 last_blk = EXT_MAX_BLOCKS-1;
5209 len_blks = ((ext4_lblk_t) last_blk) - start_blk + 1;
5210
5211 /*
5212 * Walk the extent tree gathering extent information
5213 * and pushing extents back to the user.
5214 */
5215 error = ext4_fill_fiemap_extents(inode, start_blk,
5216 len_blks, fieinfo);
5217 }
5218 return error;
5219 }
5220
5221 /*
5222 * ext4_access_path:
5223 * Function to access the path buffer for marking it dirty.
5224 * It also checks if there are sufficient credits left in the journal handle
5225 * to update path.
5226 */
5227 static int
5228 ext4_access_path(handle_t *handle, struct inode *inode,
5229 struct ext4_ext_path *path)
5230 {
5231 int credits, err;
5232
5233 if (!ext4_handle_valid(handle))
5234 return 0;
5235
5236 /*
5237 * Check if need to extend journal credits
5238 * 3 for leaf, sb, and inode plus 2 (bmap and group
5239 * descriptor) for each block group; assume two block
5240 * groups
5241 */
5242 if (handle->h_buffer_credits < 7) {
5243 credits = ext4_writepage_trans_blocks(inode);
5244 err = ext4_ext_truncate_extend_restart(handle, inode, credits);
5245 /* EAGAIN is success */
5246 if (err && err != -EAGAIN)
5247 return err;
5248 }
5249
5250 err = ext4_ext_get_access(handle, inode, path);
5251 return err;
5252 }
5253
5254 /*
5255 * ext4_ext_shift_path_extents:
5256 * Shift the extents of a path structure lying between path[depth].p_ext
5257 * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells
5258 * if it is right shift or left shift operation.
5259 */
5260 static int
5261 ext4_ext_shift_path_extents(struct ext4_ext_path *path, ext4_lblk_t shift,
5262 struct inode *inode, handle_t *handle,
5263 enum SHIFT_DIRECTION SHIFT)
5264 {
5265 int depth, err = 0;
5266 struct ext4_extent *ex_start, *ex_last;
5267 bool update = 0;
5268 depth = path->p_depth;
5269
5270 while (depth >= 0) {
5271 if (depth == path->p_depth) {
5272 ex_start = path[depth].p_ext;
5273 if (!ex_start)
5274 return -EIO;
5275
5276 ex_last = EXT_LAST_EXTENT(path[depth].p_hdr);
5277
5278 err = ext4_access_path(handle, inode, path + depth);
5279 if (err)
5280 goto out;
5281
5282 if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr))
5283 update = 1;
5284
5285 while (ex_start <= ex_last) {
5286 if (SHIFT == SHIFT_LEFT) {
5287 le32_add_cpu(&ex_start->ee_block,
5288 -shift);
5289 /* Try to merge to the left. */
5290 if ((ex_start >
5291 EXT_FIRST_EXTENT(path[depth].p_hdr))
5292 &&
5293 ext4_ext_try_to_merge_right(inode,
5294 path, ex_start - 1))
5295 ex_last--;
5296 else
5297 ex_start++;
5298 } else {
5299 le32_add_cpu(&ex_last->ee_block, shift);
5300 ext4_ext_try_to_merge_right(inode, path,
5301 ex_last);
5302 ex_last--;
5303 }
5304 }
5305 err = ext4_ext_dirty(handle, inode, path + depth);
5306 if (err)
5307 goto out;
5308
5309 if (--depth < 0 || !update)
5310 break;
5311 }
5312
5313 /* Update index too */
5314 err = ext4_access_path(handle, inode, path + depth);
5315 if (err)
5316 goto out;
5317
5318 if (SHIFT == SHIFT_LEFT)
5319 le32_add_cpu(&path[depth].p_idx->ei_block, -shift);
5320 else
5321 le32_add_cpu(&path[depth].p_idx->ei_block, shift);
5322 err = ext4_ext_dirty(handle, inode, path + depth);
5323 if (err)
5324 goto out;
5325
5326 /* we are done if current index is not a starting index */
5327 if (path[depth].p_idx != EXT_FIRST_INDEX(path[depth].p_hdr))
5328 break;
5329
5330 depth--;
5331 }
5332
5333 out:
5334 return err;
5335 }
5336
5337 /*
5338 * ext4_ext_shift_extents:
5339 * All the extents which lies in the range from @start to the last allocated
5340 * block for the @inode are shifted either towards left or right (depending
5341 * upon @SHIFT) by @shift blocks.
5342 * On success, 0 is returned, error otherwise.
5343 */
5344 static int
5345 ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
5346 ext4_lblk_t start, ext4_lblk_t shift,
5347 enum SHIFT_DIRECTION SHIFT)
5348 {
5349 struct ext4_ext_path *path;
5350 int ret = 0, depth;
5351 struct ext4_extent *extent;
5352 ext4_lblk_t stop, *iterator, ex_start, ex_end;
5353
5354 /* Let path point to the last extent */
5355 path = ext4_find_extent(inode, EXT_MAX_BLOCKS - 1, NULL, 0);
5356 if (IS_ERR(path))
5357 return PTR_ERR(path);
5358
5359 depth = path->p_depth;
5360 extent = path[depth].p_ext;
5361 if (!extent)
5362 goto out;
5363
5364 stop = le32_to_cpu(extent->ee_block) +
5365 ext4_ext_get_actual_len(extent);
5366
5367 /*
5368 * In case of left shift, Don't start shifting extents until we make
5369 * sure the hole is big enough to accommodate the shift.
5370 */
5371 if (SHIFT == SHIFT_LEFT) {
5372 path = ext4_find_extent(inode, start - 1, &path, 0);
5373 if (IS_ERR(path))
5374 return PTR_ERR(path);
5375 depth = path->p_depth;
5376 extent = path[depth].p_ext;
5377 if (extent) {
5378 ex_start = le32_to_cpu(extent->ee_block);
5379 ex_end = le32_to_cpu(extent->ee_block) +
5380 ext4_ext_get_actual_len(extent);
5381 } else {
5382 ex_start = 0;
5383 ex_end = 0;
5384 }
5385
5386 if ((start == ex_start && shift > ex_start) ||
5387 (shift > start - ex_end)) {
5388 ext4_ext_drop_refs(path);
5389 kfree(path);
5390 return -EINVAL;
5391 }
5392 }
5393
5394 /*
5395 * In case of left shift, iterator points to start and it is increased
5396 * till we reach stop. In case of right shift, iterator points to stop
5397 * and it is decreased till we reach start.
5398 */
5399 if (SHIFT == SHIFT_LEFT)
5400 iterator = &start;
5401 else
5402 iterator = &stop;
5403
5404 /* Its safe to start updating extents */
5405 while (start < stop) {
5406 path = ext4_find_extent(inode, *iterator, &path, 0);
5407 if (IS_ERR(path))
5408 return PTR_ERR(path);
5409 depth = path->p_depth;
5410 extent = path[depth].p_ext;
5411 if (!extent) {
5412 EXT4_ERROR_INODE(inode, "unexpected hole at %lu",
5413 (unsigned long) *iterator);
5414 return -EIO;
5415 }
5416 if (SHIFT == SHIFT_LEFT && *iterator >
5417 le32_to_cpu(extent->ee_block)) {
5418 /* Hole, move to the next extent */
5419 if (extent < EXT_LAST_EXTENT(path[depth].p_hdr)) {
5420 path[depth].p_ext++;
5421 } else {
5422 *iterator = ext4_ext_next_allocated_block(path);
5423 continue;
5424 }
5425 }
5426
5427 if (SHIFT == SHIFT_LEFT) {
5428 extent = EXT_LAST_EXTENT(path[depth].p_hdr);
5429 *iterator = le32_to_cpu(extent->ee_block) +
5430 ext4_ext_get_actual_len(extent);
5431 } else {
5432 extent = EXT_FIRST_EXTENT(path[depth].p_hdr);
5433 *iterator = le32_to_cpu(extent->ee_block) > 0 ?
5434 le32_to_cpu(extent->ee_block) - 1 : 0;
5435 /* Update path extent in case we need to stop */
5436 while (le32_to_cpu(extent->ee_block) < start)
5437 extent++;
5438 path[depth].p_ext = extent;
5439 }
5440 ret = ext4_ext_shift_path_extents(path, shift, inode,
5441 handle, SHIFT);
5442 if (ret)
5443 break;
5444 }
5445 out:
5446 ext4_ext_drop_refs(path);
5447 kfree(path);
5448 return ret;
5449 }
5450
5451 /*
5452 * ext4_collapse_range:
5453 * This implements the fallocate's collapse range functionality for ext4
5454 * Returns: 0 and non-zero on error.
5455 */
5456 int ext4_collapse_range(struct inode *inode, loff_t offset, loff_t len)
5457 {
5458 struct super_block *sb = inode->i_sb;
5459 ext4_lblk_t punch_start, punch_stop;
5460 handle_t *handle;
5461 unsigned int credits;
5462 loff_t new_size, ioffset;
5463 int ret;
5464
5465 /*
5466 * We need to test this early because xfstests assumes that a
5467 * collapse range of (0, 1) will return EOPNOTSUPP if the file
5468 * system does not support collapse range.
5469 */
5470 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5471 return -EOPNOTSUPP;
5472
5473 /* Collapse range works only on fs block size aligned offsets. */
5474 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
5475 len & (EXT4_CLUSTER_SIZE(sb) - 1))
5476 return -EINVAL;
5477
5478 if (!S_ISREG(inode->i_mode))
5479 return -EINVAL;
5480
5481 trace_ext4_collapse_range(inode, offset, len);
5482
5483 punch_start = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5484 punch_stop = (offset + len) >> EXT4_BLOCK_SIZE_BITS(sb);
5485
5486 /* Call ext4_force_commit to flush all data in case of data=journal. */
5487 if (ext4_should_journal_data(inode)) {
5488 ret = ext4_force_commit(inode->i_sb);
5489 if (ret)
5490 return ret;
5491 }
5492
5493 /*
5494 * Need to round down offset to be aligned with page size boundary
5495 * for page size > block size.
5496 */
5497 ioffset = round_down(offset, PAGE_SIZE);
5498
5499 /* Write out all dirty pages */
5500 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5501 LLONG_MAX);
5502 if (ret)
5503 return ret;
5504
5505 /* Take mutex lock */
5506 mutex_lock(&inode->i_mutex);
5507
5508 /*
5509 * There is no need to overlap collapse range with EOF, in which case
5510 * it is effectively a truncate operation
5511 */
5512 if (offset + len >= i_size_read(inode)) {
5513 ret = -EINVAL;
5514 goto out_mutex;
5515 }
5516
5517 /* Currently just for extent based files */
5518 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5519 ret = -EOPNOTSUPP;
5520 goto out_mutex;
5521 }
5522
5523 truncate_pagecache(inode, ioffset);
5524
5525 /* Wait for existing dio to complete */
5526 ext4_inode_block_unlocked_dio(inode);
5527 inode_dio_wait(inode);
5528
5529 credits = ext4_writepage_trans_blocks(inode);
5530 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5531 if (IS_ERR(handle)) {
5532 ret = PTR_ERR(handle);
5533 goto out_dio;
5534 }
5535
5536 down_write(&EXT4_I(inode)->i_data_sem);
5537 ext4_discard_preallocations(inode);
5538
5539 ret = ext4_es_remove_extent(inode, punch_start,
5540 EXT_MAX_BLOCKS - punch_start);
5541 if (ret) {
5542 up_write(&EXT4_I(inode)->i_data_sem);
5543 goto out_stop;
5544 }
5545
5546 ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
5547 if (ret) {
5548 up_write(&EXT4_I(inode)->i_data_sem);
5549 goto out_stop;
5550 }
5551 ext4_discard_preallocations(inode);
5552
5553 ret = ext4_ext_shift_extents(inode, handle, punch_stop,
5554 punch_stop - punch_start, SHIFT_LEFT);
5555 if (ret) {
5556 up_write(&EXT4_I(inode)->i_data_sem);
5557 goto out_stop;
5558 }
5559
5560 new_size = i_size_read(inode) - len;
5561 i_size_write(inode, new_size);
5562 EXT4_I(inode)->i_disksize = new_size;
5563
5564 up_write(&EXT4_I(inode)->i_data_sem);
5565 if (IS_SYNC(inode))
5566 ext4_handle_sync(handle);
5567 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
5568 ext4_mark_inode_dirty(handle, inode);
5569
5570 out_stop:
5571 ext4_journal_stop(handle);
5572 out_dio:
5573 ext4_inode_resume_unlocked_dio(inode);
5574 out_mutex:
5575 mutex_unlock(&inode->i_mutex);
5576 return ret;
5577 }
5578
5579 /*
5580 * ext4_insert_range:
5581 * This function implements the FALLOC_FL_INSERT_RANGE flag of fallocate.
5582 * The data blocks starting from @offset to the EOF are shifted by @len
5583 * towards right to create a hole in the @inode. Inode size is increased
5584 * by len bytes.
5585 * Returns 0 on success, error otherwise.
5586 */
5587 int ext4_insert_range(struct inode *inode, loff_t offset, loff_t len)
5588 {
5589 struct super_block *sb = inode->i_sb;
5590 handle_t *handle;
5591 struct ext4_ext_path *path;
5592 struct ext4_extent *extent;
5593 ext4_lblk_t offset_lblk, len_lblk, ee_start_lblk = 0;
5594 unsigned int credits, ee_len;
5595 int ret = 0, depth, split_flag = 0;
5596 loff_t ioffset;
5597
5598 /*
5599 * We need to test this early because xfstests assumes that an
5600 * insert range of (0, 1) will return EOPNOTSUPP if the file
5601 * system does not support insert range.
5602 */
5603 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
5604 return -EOPNOTSUPP;
5605
5606 /* Insert range works only on fs block size aligned offsets. */
5607 if (offset & (EXT4_CLUSTER_SIZE(sb) - 1) ||
5608 len & (EXT4_CLUSTER_SIZE(sb) - 1))
5609 return -EINVAL;
5610
5611 if (!S_ISREG(inode->i_mode))
5612 return -EOPNOTSUPP;
5613
5614 trace_ext4_insert_range(inode, offset, len);
5615
5616 offset_lblk = offset >> EXT4_BLOCK_SIZE_BITS(sb);
5617 len_lblk = len >> EXT4_BLOCK_SIZE_BITS(sb);
5618
5619 /* Call ext4_force_commit to flush all data in case of data=journal */
5620 if (ext4_should_journal_data(inode)) {
5621 ret = ext4_force_commit(inode->i_sb);
5622 if (ret)
5623 return ret;
5624 }
5625
5626 /*
5627 * Need to round down to align start offset to page size boundary
5628 * for page size > block size.
5629 */
5630 ioffset = round_down(offset, PAGE_SIZE);
5631
5632 /* Write out all dirty pages */
5633 ret = filemap_write_and_wait_range(inode->i_mapping, ioffset,
5634 LLONG_MAX);
5635 if (ret)
5636 return ret;
5637
5638 /* Take mutex lock */
5639 mutex_lock(&inode->i_mutex);
5640
5641 /* Currently just for extent based files */
5642 if (!ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) {
5643 ret = -EOPNOTSUPP;
5644 goto out_mutex;
5645 }
5646
5647 /* Check for wrap through zero */
5648 if (inode->i_size + len > inode->i_sb->s_maxbytes) {
5649 ret = -EFBIG;
5650 goto out_mutex;
5651 }
5652
5653 /* Offset should be less than i_size */
5654 if (offset >= i_size_read(inode)) {
5655 ret = -EINVAL;
5656 goto out_mutex;
5657 }
5658
5659 truncate_pagecache(inode, ioffset);
5660
5661 /* Wait for existing dio to complete */
5662 ext4_inode_block_unlocked_dio(inode);
5663 inode_dio_wait(inode);
5664
5665 credits = ext4_writepage_trans_blocks(inode);
5666 handle = ext4_journal_start(inode, EXT4_HT_TRUNCATE, credits);
5667 if (IS_ERR(handle)) {
5668 ret = PTR_ERR(handle);
5669 goto out_dio;
5670 }
5671
5672 /* Expand file to avoid data loss if there is error while shifting */
5673 inode->i_size += len;
5674 EXT4_I(inode)->i_disksize += len;
5675 inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
5676 ret = ext4_mark_inode_dirty(handle, inode);
5677 if (ret)
5678 goto out_stop;
5679
5680 down_write(&EXT4_I(inode)->i_data_sem);
5681 ext4_discard_preallocations(inode);
5682
5683 path = ext4_find_extent(inode, offset_lblk, NULL, 0);
5684 if (IS_ERR(path)) {
5685 up_write(&EXT4_I(inode)->i_data_sem);
5686 goto out_stop;
5687 }
5688
5689 depth = ext_depth(inode);
5690 extent = path[depth].p_ext;
5691 if (extent) {
5692 ee_start_lblk = le32_to_cpu(extent->ee_block);
5693 ee_len = ext4_ext_get_actual_len(extent);
5694
5695 /*
5696 * If offset_lblk is not the starting block of extent, split
5697 * the extent @offset_lblk
5698 */
5699 if ((offset_lblk > ee_start_lblk) &&
5700 (offset_lblk < (ee_start_lblk + ee_len))) {
5701 if (ext4_ext_is_unwritten(extent))
5702 split_flag = EXT4_EXT_MARK_UNWRIT1 |
5703 EXT4_EXT_MARK_UNWRIT2;
5704 ret = ext4_split_extent_at(handle, inode, &path,
5705 offset_lblk, split_flag,
5706 EXT4_EX_NOCACHE |
5707 EXT4_GET_BLOCKS_PRE_IO |
5708 EXT4_GET_BLOCKS_METADATA_NOFAIL);
5709 }
5710
5711 ext4_ext_drop_refs(path);
5712 kfree(path);
5713 if (ret < 0) {
5714 up_write(&EXT4_I(inode)->i_data_sem);
5715 goto out_stop;
5716 }
5717 }
5718
5719 ret = ext4_es_remove_extent(inode, offset_lblk,
5720 EXT_MAX_BLOCKS - offset_lblk);
5721 if (ret) {
5722 up_write(&EXT4_I(inode)->i_data_sem);
5723 goto out_stop;
5724 }
5725
5726 /*
5727 * if offset_lblk lies in a hole which is at start of file, use
5728 * ee_start_lblk to shift extents
5729 */
5730 ret = ext4_ext_shift_extents(inode, handle,
5731 ee_start_lblk > offset_lblk ? ee_start_lblk : offset_lblk,
5732 len_lblk, SHIFT_RIGHT);
5733
5734 up_write(&EXT4_I(inode)->i_data_sem);
5735 if (IS_SYNC(inode))
5736 ext4_handle_sync(handle);
5737
5738 out_stop:
5739 ext4_journal_stop(handle);
5740 out_dio:
5741 ext4_inode_resume_unlocked_dio(inode);
5742 out_mutex:
5743 mutex_unlock(&inode->i_mutex);
5744 return ret;
5745 }
5746
5747 /**
5748 * ext4_swap_extents - Swap extents between two inodes
5749 *
5750 * @inode1: First inode
5751 * @inode2: Second inode
5752 * @lblk1: Start block for first inode
5753 * @lblk2: Start block for second inode
5754 * @count: Number of blocks to swap
5755 * @mark_unwritten: Mark second inode's extents as unwritten after swap
5756 * @erp: Pointer to save error value
5757 *
5758 * This helper routine does exactly what is promise "swap extents". All other
5759 * stuff such as page-cache locking consistency, bh mapping consistency or
5760 * extent's data copying must be performed by caller.
5761 * Locking:
5762 * i_mutex is held for both inodes
5763 * i_data_sem is locked for write for both inodes
5764 * Assumptions:
5765 * All pages from requested range are locked for both inodes
5766 */
5767 int
5768 ext4_swap_extents(handle_t *handle, struct inode *inode1,
5769 struct inode *inode2, ext4_lblk_t lblk1, ext4_lblk_t lblk2,
5770 ext4_lblk_t count, int unwritten, int *erp)
5771 {
5772 struct ext4_ext_path *path1 = NULL;
5773 struct ext4_ext_path *path2 = NULL;
5774 int replaced_count = 0;
5775
5776 BUG_ON(!rwsem_is_locked(&EXT4_I(inode1)->i_data_sem));
5777 BUG_ON(!rwsem_is_locked(&EXT4_I(inode2)->i_data_sem));
5778 BUG_ON(!mutex_is_locked(&inode1->i_mutex));
5779 BUG_ON(!mutex_is_locked(&inode2->i_mutex));
5780
5781 *erp = ext4_es_remove_extent(inode1, lblk1, count);
5782 if (unlikely(*erp))
5783 return 0;
5784 *erp = ext4_es_remove_extent(inode2, lblk2, count);
5785 if (unlikely(*erp))
5786 return 0;
5787
5788 while (count) {
5789 struct ext4_extent *ex1, *ex2, tmp_ex;
5790 ext4_lblk_t e1_blk, e2_blk;
5791 int e1_len, e2_len, len;
5792 int split = 0;
5793
5794 path1 = ext4_find_extent(inode1, lblk1, NULL, EXT4_EX_NOCACHE);
5795 if (unlikely(IS_ERR(path1))) {
5796 *erp = PTR_ERR(path1);
5797 path1 = NULL;
5798 finish:
5799 count = 0;
5800 goto repeat;
5801 }
5802 path2 = ext4_find_extent(inode2, lblk2, NULL, EXT4_EX_NOCACHE);
5803 if (unlikely(IS_ERR(path2))) {
5804 *erp = PTR_ERR(path2);
5805 path2 = NULL;
5806 goto finish;
5807 }
5808 ex1 = path1[path1->p_depth].p_ext;
5809 ex2 = path2[path2->p_depth].p_ext;
5810 /* Do we have somthing to swap ? */
5811 if (unlikely(!ex2 || !ex1))
5812 goto finish;
5813
5814 e1_blk = le32_to_cpu(ex1->ee_block);
5815 e2_blk = le32_to_cpu(ex2->ee_block);
5816 e1_len = ext4_ext_get_actual_len(ex1);
5817 e2_len = ext4_ext_get_actual_len(ex2);
5818
5819 /* Hole handling */
5820 if (!in_range(lblk1, e1_blk, e1_len) ||
5821 !in_range(lblk2, e2_blk, e2_len)) {
5822 ext4_lblk_t next1, next2;
5823
5824 /* if hole after extent, then go to next extent */
5825 next1 = ext4_ext_next_allocated_block(path1);
5826 next2 = ext4_ext_next_allocated_block(path2);
5827 /* If hole before extent, then shift to that extent */
5828 if (e1_blk > lblk1)
5829 next1 = e1_blk;
5830 if (e2_blk > lblk2)
5831 next2 = e1_blk;
5832 /* Do we have something to swap */
5833 if (next1 == EXT_MAX_BLOCKS || next2 == EXT_MAX_BLOCKS)
5834 goto finish;
5835 /* Move to the rightest boundary */
5836 len = next1 - lblk1;
5837 if (len < next2 - lblk2)
5838 len = next2 - lblk2;
5839 if (len > count)
5840 len = count;
5841 lblk1 += len;
5842 lblk2 += len;
5843 count -= len;
5844 goto repeat;
5845 }
5846
5847 /* Prepare left boundary */
5848 if (e1_blk < lblk1) {
5849 split = 1;
5850 *erp = ext4_force_split_extent_at(handle, inode1,
5851 &path1, lblk1, 0);
5852 if (unlikely(*erp))
5853 goto finish;
5854 }
5855 if (e2_blk < lblk2) {
5856 split = 1;
5857 *erp = ext4_force_split_extent_at(handle, inode2,
5858 &path2, lblk2, 0);
5859 if (unlikely(*erp))
5860 goto finish;
5861 }
5862 /* ext4_split_extent_at() may result in leaf extent split,
5863 * path must to be revalidated. */
5864 if (split)
5865 goto repeat;
5866
5867 /* Prepare right boundary */
5868 len = count;
5869 if (len > e1_blk + e1_len - lblk1)
5870 len = e1_blk + e1_len - lblk1;
5871 if (len > e2_blk + e2_len - lblk2)
5872 len = e2_blk + e2_len - lblk2;
5873
5874 if (len != e1_len) {
5875 split = 1;
5876 *erp = ext4_force_split_extent_at(handle, inode1,
5877 &path1, lblk1 + len, 0);
5878 if (unlikely(*erp))
5879 goto finish;
5880 }
5881 if (len != e2_len) {
5882 split = 1;
5883 *erp = ext4_force_split_extent_at(handle, inode2,
5884 &path2, lblk2 + len, 0);
5885 if (*erp)
5886 goto finish;
5887 }
5888 /* ext4_split_extent_at() may result in leaf extent split,
5889 * path must to be revalidated. */
5890 if (split)
5891 goto repeat;
5892
5893 BUG_ON(e2_len != e1_len);
5894 *erp = ext4_ext_get_access(handle, inode1, path1 + path1->p_depth);
5895 if (unlikely(*erp))
5896 goto finish;
5897 *erp = ext4_ext_get_access(handle, inode2, path2 + path2->p_depth);
5898 if (unlikely(*erp))
5899 goto finish;
5900
5901 /* Both extents are fully inside boundaries. Swap it now */
5902 tmp_ex = *ex1;
5903 ext4_ext_store_pblock(ex1, ext4_ext_pblock(ex2));
5904 ext4_ext_store_pblock(ex2, ext4_ext_pblock(&tmp_ex));
5905 ex1->ee_len = cpu_to_le16(e2_len);
5906 ex2->ee_len = cpu_to_le16(e1_len);
5907 if (unwritten)
5908 ext4_ext_mark_unwritten(ex2);
5909 if (ext4_ext_is_unwritten(&tmp_ex))
5910 ext4_ext_mark_unwritten(ex1);
5911
5912 ext4_ext_try_to_merge(handle, inode2, path2, ex2);
5913 ext4_ext_try_to_merge(handle, inode1, path1, ex1);
5914 *erp = ext4_ext_dirty(handle, inode2, path2 +
5915 path2->p_depth);
5916 if (unlikely(*erp))
5917 goto finish;
5918 *erp = ext4_ext_dirty(handle, inode1, path1 +
5919 path1->p_depth);
5920 /*
5921 * Looks scarry ah..? second inode already points to new blocks,
5922 * and it was successfully dirtied. But luckily error may happen
5923 * only due to journal error, so full transaction will be
5924 * aborted anyway.
5925 */
5926 if (unlikely(*erp))
5927 goto finish;
5928 lblk1 += len;
5929 lblk2 += len;
5930 replaced_count += len;
5931 count -= len;
5932
5933 repeat:
5934 ext4_ext_drop_refs(path1);
5935 kfree(path1);
5936 ext4_ext_drop_refs(path2);
5937 kfree(path2);
5938 path1 = path2 = NULL;
5939 }
5940 return replaced_count;
5941 }
Linux with added FPC-III support