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1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (C) 2007 Oracle. All rights reserved.
4 */
5
6#include <linux/fs.h>
7#include <linux/pagemap.h>
8#include <linux/time.h>
9#include <linux/init.h>
10#include <linux/string.h>
11#include <linux/backing-dev.h>
12#include <linux/falloc.h>
13#include <linux/writeback.h>
14#include <linux/compat.h>
15#include <linux/slab.h>
16#include <linux/btrfs.h>
17#include <linux/uio.h>
18#include <linux/iversion.h>
19#include "ctree.h"
20#include "disk-io.h"
21#include "transaction.h"
22#include "btrfs_inode.h"
23#include "print-tree.h"
24#include "tree-log.h"
25#include "locking.h"
26#include "volumes.h"
27#include "qgroup.h"
28#include "compression.h"
29#include "delalloc-space.h"
30
31static struct kmem_cache *btrfs_inode_defrag_cachep;
32/*
33 * when auto defrag is enabled we
34 * queue up these defrag structs to remember which
35 * inodes need defragging passes
36 */
37struct inode_defrag {
38 struct rb_node rb_node;
39 /* objectid */
40 u64 ino;
41 /*
42 * transid where the defrag was added, we search for
43 * extents newer than this
44 */
45 u64 transid;
46
47 /* root objectid */
48 u64 root;
49
50 /* last offset we were able to defrag */
51 u64 last_offset;
52
53 /* if we've wrapped around back to zero once already */
54 int cycled;
55};
56
57static int __compare_inode_defrag(struct inode_defrag *defrag1,
58 struct inode_defrag *defrag2)
59{
60 if (defrag1->root > defrag2->root)
61 return 1;
62 else if (defrag1->root < defrag2->root)
63 return -1;
64 else if (defrag1->ino > defrag2->ino)
65 return 1;
66 else if (defrag1->ino < defrag2->ino)
67 return -1;
68 else
69 return 0;
70}
71
72/* pop a record for an inode into the defrag tree. The lock
73 * must be held already
74 *
75 * If you're inserting a record for an older transid than an
76 * existing record, the transid already in the tree is lowered
77 *
78 * If an existing record is found the defrag item you
79 * pass in is freed
80 */
81static int __btrfs_add_inode_defrag(struct btrfs_inode *inode,
82 struct inode_defrag *defrag)
83{
84 struct btrfs_fs_info *fs_info = inode->root->fs_info;
85 struct inode_defrag *entry;
86 struct rb_node **p;
87 struct rb_node *parent = NULL;
88 int ret;
89
90 p = &fs_info->defrag_inodes.rb_node;
91 while (*p) {
92 parent = *p;
93 entry = rb_entry(parent, struct inode_defrag, rb_node);
94
95 ret = __compare_inode_defrag(defrag, entry);
96 if (ret < 0)
97 p = &parent->rb_left;
98 else if (ret > 0)
99 p = &parent->rb_right;
100 else {
101 /* if we're reinserting an entry for
102 * an old defrag run, make sure to
103 * lower the transid of our existing record
104 */
105 if (defrag->transid < entry->transid)
106 entry->transid = defrag->transid;
107 if (defrag->last_offset > entry->last_offset)
108 entry->last_offset = defrag->last_offset;
109 return -EEXIST;
110 }
111 }
112 set_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags);
113 rb_link_node(&defrag->rb_node, parent, p);
114 rb_insert_color(&defrag->rb_node, &fs_info->defrag_inodes);
115 return 0;
116}
117
118static inline int __need_auto_defrag(struct btrfs_fs_info *fs_info)
119{
120 if (!btrfs_test_opt(fs_info, AUTO_DEFRAG))
121 return 0;
122
123 if (btrfs_fs_closing(fs_info))
124 return 0;
125
126 return 1;
127}
128
129/*
130 * insert a defrag record for this inode if auto defrag is
131 * enabled
132 */
133int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
134 struct btrfs_inode *inode)
135{
136 struct btrfs_root *root = inode->root;
137 struct btrfs_fs_info *fs_info = root->fs_info;
138 struct inode_defrag *defrag;
139 u64 transid;
140 int ret;
141
142 if (!__need_auto_defrag(fs_info))
143 return 0;
144
145 if (test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags))
146 return 0;
147
148 if (trans)
149 transid = trans->transid;
150 else
151 transid = inode->root->last_trans;
152
153 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
154 if (!defrag)
155 return -ENOMEM;
156
157 defrag->ino = btrfs_ino(inode);
158 defrag->transid = transid;
159 defrag->root = root->root_key.objectid;
160
161 spin_lock(&fs_info->defrag_inodes_lock);
162 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags)) {
163 /*
164 * If we set IN_DEFRAG flag and evict the inode from memory,
165 * and then re-read this inode, this new inode doesn't have
166 * IN_DEFRAG flag. At the case, we may find the existed defrag.
167 */
168 ret = __btrfs_add_inode_defrag(inode, defrag);
169 if (ret)
170 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
171 } else {
172 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
173 }
174 spin_unlock(&fs_info->defrag_inodes_lock);
175 return 0;
176}
177
178/*
179 * Requeue the defrag object. If there is a defrag object that points to
180 * the same inode in the tree, we will merge them together (by
181 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
182 */
183static void btrfs_requeue_inode_defrag(struct btrfs_inode *inode,
184 struct inode_defrag *defrag)
185{
186 struct btrfs_fs_info *fs_info = inode->root->fs_info;
187 int ret;
188
189 if (!__need_auto_defrag(fs_info))
190 goto out;
191
192 /*
193 * Here we don't check the IN_DEFRAG flag, because we need merge
194 * them together.
195 */
196 spin_lock(&fs_info->defrag_inodes_lock);
197 ret = __btrfs_add_inode_defrag(inode, defrag);
198 spin_unlock(&fs_info->defrag_inodes_lock);
199 if (ret)
200 goto out;
201 return;
202out:
203 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
204}
205
206/*
207 * pick the defragable inode that we want, if it doesn't exist, we will get
208 * the next one.
209 */
210static struct inode_defrag *
211btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
212{
213 struct inode_defrag *entry = NULL;
214 struct inode_defrag tmp;
215 struct rb_node *p;
216 struct rb_node *parent = NULL;
217 int ret;
218
219 tmp.ino = ino;
220 tmp.root = root;
221
222 spin_lock(&fs_info->defrag_inodes_lock);
223 p = fs_info->defrag_inodes.rb_node;
224 while (p) {
225 parent = p;
226 entry = rb_entry(parent, struct inode_defrag, rb_node);
227
228 ret = __compare_inode_defrag(&tmp, entry);
229 if (ret < 0)
230 p = parent->rb_left;
231 else if (ret > 0)
232 p = parent->rb_right;
233 else
234 goto out;
235 }
236
237 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
238 parent = rb_next(parent);
239 if (parent)
240 entry = rb_entry(parent, struct inode_defrag, rb_node);
241 else
242 entry = NULL;
243 }
244out:
245 if (entry)
246 rb_erase(parent, &fs_info->defrag_inodes);
247 spin_unlock(&fs_info->defrag_inodes_lock);
248 return entry;
249}
250
251void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
252{
253 struct inode_defrag *defrag;
254 struct rb_node *node;
255
256 spin_lock(&fs_info->defrag_inodes_lock);
257 node = rb_first(&fs_info->defrag_inodes);
258 while (node) {
259 rb_erase(node, &fs_info->defrag_inodes);
260 defrag = rb_entry(node, struct inode_defrag, rb_node);
261 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
262
263 cond_resched_lock(&fs_info->defrag_inodes_lock);
264
265 node = rb_first(&fs_info->defrag_inodes);
266 }
267 spin_unlock(&fs_info->defrag_inodes_lock);
268}
269
270#define BTRFS_DEFRAG_BATCH 1024
271
272static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
273 struct inode_defrag *defrag)
274{
275 struct btrfs_root *inode_root;
276 struct inode *inode;
277 struct btrfs_key key;
278 struct btrfs_ioctl_defrag_range_args range;
279 int num_defrag;
280 int index;
281 int ret;
282
283 /* get the inode */
284 key.objectid = defrag->root;
285 key.type = BTRFS_ROOT_ITEM_KEY;
286 key.offset = (u64)-1;
287
288 index = srcu_read_lock(&fs_info->subvol_srcu);
289
290 inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
291 if (IS_ERR(inode_root)) {
292 ret = PTR_ERR(inode_root);
293 goto cleanup;
294 }
295
296 key.objectid = defrag->ino;
297 key.type = BTRFS_INODE_ITEM_KEY;
298 key.offset = 0;
299 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
300 if (IS_ERR(inode)) {
301 ret = PTR_ERR(inode);
302 goto cleanup;
303 }
304 srcu_read_unlock(&fs_info->subvol_srcu, index);
305
306 /* do a chunk of defrag */
307 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
308 memset(&range, 0, sizeof(range));
309 range.len = (u64)-1;
310 range.start = defrag->last_offset;
311
312 sb_start_write(fs_info->sb);
313 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
314 BTRFS_DEFRAG_BATCH);
315 sb_end_write(fs_info->sb);
316 /*
317 * if we filled the whole defrag batch, there
318 * must be more work to do. Queue this defrag
319 * again
320 */
321 if (num_defrag == BTRFS_DEFRAG_BATCH) {
322 defrag->last_offset = range.start;
323 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
324 } else if (defrag->last_offset && !defrag->cycled) {
325 /*
326 * we didn't fill our defrag batch, but
327 * we didn't start at zero. Make sure we loop
328 * around to the start of the file.
329 */
330 defrag->last_offset = 0;
331 defrag->cycled = 1;
332 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
333 } else {
334 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
335 }
336
337 iput(inode);
338 return 0;
339cleanup:
340 srcu_read_unlock(&fs_info->subvol_srcu, index);
341 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
342 return ret;
343}
344
345/*
346 * run through the list of inodes in the FS that need
347 * defragging
348 */
349int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
350{
351 struct inode_defrag *defrag;
352 u64 first_ino = 0;
353 u64 root_objectid = 0;
354
355 atomic_inc(&fs_info->defrag_running);
356 while (1) {
357 /* Pause the auto defragger. */
358 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
359 &fs_info->fs_state))
360 break;
361
362 if (!__need_auto_defrag(fs_info))
363 break;
364
365 /* find an inode to defrag */
366 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
367 first_ino);
368 if (!defrag) {
369 if (root_objectid || first_ino) {
370 root_objectid = 0;
371 first_ino = 0;
372 continue;
373 } else {
374 break;
375 }
376 }
377
378 first_ino = defrag->ino + 1;
379 root_objectid = defrag->root;
380
381 __btrfs_run_defrag_inode(fs_info, defrag);
382 }
383 atomic_dec(&fs_info->defrag_running);
384
385 /*
386 * during unmount, we use the transaction_wait queue to
387 * wait for the defragger to stop
388 */
389 wake_up(&fs_info->transaction_wait);
390 return 0;
391}
392
393/* simple helper to fault in pages and copy. This should go away
394 * and be replaced with calls into generic code.
395 */
396static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
397 struct page **prepared_pages,
398 struct iov_iter *i)
399{
400 size_t copied = 0;
401 size_t total_copied = 0;
402 int pg = 0;
403 int offset = offset_in_page(pos);
404
405 while (write_bytes > 0) {
406 size_t count = min_t(size_t,
407 PAGE_SIZE - offset, write_bytes);
408 struct page *page = prepared_pages[pg];
409 /*
410 * Copy data from userspace to the current page
411 */
412 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
413
414 /* Flush processor's dcache for this page */
415 flush_dcache_page(page);
416
417 /*
418 * if we get a partial write, we can end up with
419 * partially up to date pages. These add
420 * a lot of complexity, so make sure they don't
421 * happen by forcing this copy to be retried.
422 *
423 * The rest of the btrfs_file_write code will fall
424 * back to page at a time copies after we return 0.
425 */
426 if (!PageUptodate(page) && copied < count)
427 copied = 0;
428
429 iov_iter_advance(i, copied);
430 write_bytes -= copied;
431 total_copied += copied;
432
433 /* Return to btrfs_file_write_iter to fault page */
434 if (unlikely(copied == 0))
435 break;
436
437 if (copied < PAGE_SIZE - offset) {
438 offset += copied;
439 } else {
440 pg++;
441 offset = 0;
442 }
443 }
444 return total_copied;
445}
446
447/*
448 * unlocks pages after btrfs_file_write is done with them
449 */
450static void btrfs_drop_pages(struct page **pages, size_t num_pages)
451{
452 size_t i;
453 for (i = 0; i < num_pages; i++) {
454 /* page checked is some magic around finding pages that
455 * have been modified without going through btrfs_set_page_dirty
456 * clear it here. There should be no need to mark the pages
457 * accessed as prepare_pages should have marked them accessed
458 * in prepare_pages via find_or_create_page()
459 */
460 ClearPageChecked(pages[i]);
461 unlock_page(pages[i]);
462 put_page(pages[i]);
463 }
464}
465
466static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
467 const u64 start,
468 const u64 len,
469 struct extent_state **cached_state)
470{
471 u64 search_start = start;
472 const u64 end = start + len - 1;
473
474 while (search_start < end) {
475 const u64 search_len = end - search_start + 1;
476 struct extent_map *em;
477 u64 em_len;
478 int ret = 0;
479
480 em = btrfs_get_extent(inode, NULL, 0, search_start,
481 search_len, 0);
482 if (IS_ERR(em))
483 return PTR_ERR(em);
484
485 if (em->block_start != EXTENT_MAP_HOLE)
486 goto next;
487
488 em_len = em->len;
489 if (em->start < search_start)
490 em_len -= search_start - em->start;
491 if (em_len > search_len)
492 em_len = search_len;
493
494 ret = set_extent_bit(&inode->io_tree, search_start,
495 search_start + em_len - 1,
496 EXTENT_DELALLOC_NEW,
497 NULL, cached_state, GFP_NOFS);
498next:
499 search_start = extent_map_end(em);
500 free_extent_map(em);
501 if (ret)
502 return ret;
503 }
504 return 0;
505}
506
507/*
508 * after copy_from_user, pages need to be dirtied and we need to make
509 * sure holes are created between the current EOF and the start of
510 * any next extents (if required).
511 *
512 * this also makes the decision about creating an inline extent vs
513 * doing real data extents, marking pages dirty and delalloc as required.
514 */
515int btrfs_dirty_pages(struct inode *inode, struct page **pages,
516 size_t num_pages, loff_t pos, size_t write_bytes,
517 struct extent_state **cached)
518{
519 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
520 int err = 0;
521 int i;
522 u64 num_bytes;
523 u64 start_pos;
524 u64 end_of_last_block;
525 u64 end_pos = pos + write_bytes;
526 loff_t isize = i_size_read(inode);
527 unsigned int extra_bits = 0;
528
529 start_pos = pos & ~((u64) fs_info->sectorsize - 1);
530 num_bytes = round_up(write_bytes + pos - start_pos,
531 fs_info->sectorsize);
532
533 end_of_last_block = start_pos + num_bytes - 1;
534
535 /*
536 * The pages may have already been dirty, clear out old accounting so
537 * we can set things up properly
538 */
539 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos, end_of_last_block,
540 EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
541 0, 0, cached);
542
543 if (!btrfs_is_free_space_inode(BTRFS_I(inode))) {
544 if (start_pos >= isize &&
545 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) {
546 /*
547 * There can't be any extents following eof in this case
548 * so just set the delalloc new bit for the range
549 * directly.
550 */
551 extra_bits |= EXTENT_DELALLOC_NEW;
552 } else {
553 err = btrfs_find_new_delalloc_bytes(BTRFS_I(inode),
554 start_pos,
555 num_bytes, cached);
556 if (err)
557 return err;
558 }
559 }
560
561 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
562 extra_bits, cached);
563 if (err)
564 return err;
565
566 for (i = 0; i < num_pages; i++) {
567 struct page *p = pages[i];
568 SetPageUptodate(p);
569 ClearPageChecked(p);
570 set_page_dirty(p);
571 }
572
573 /*
574 * we've only changed i_size in ram, and we haven't updated
575 * the disk i_size. There is no need to log the inode
576 * at this time.
577 */
578 if (end_pos > isize)
579 i_size_write(inode, end_pos);
580 return 0;
581}
582
583/*
584 * this drops all the extents in the cache that intersect the range
585 * [start, end]. Existing extents are split as required.
586 */
587void btrfs_drop_extent_cache(struct btrfs_inode *inode, u64 start, u64 end,
588 int skip_pinned)
589{
590 struct extent_map *em;
591 struct extent_map *split = NULL;
592 struct extent_map *split2 = NULL;
593 struct extent_map_tree *em_tree = &inode->extent_tree;
594 u64 len = end - start + 1;
595 u64 gen;
596 int ret;
597 int testend = 1;
598 unsigned long flags;
599 int compressed = 0;
600 bool modified;
601
602 WARN_ON(end < start);
603 if (end == (u64)-1) {
604 len = (u64)-1;
605 testend = 0;
606 }
607 while (1) {
608 int no_splits = 0;
609
610 modified = false;
611 if (!split)
612 split = alloc_extent_map();
613 if (!split2)
614 split2 = alloc_extent_map();
615 if (!split || !split2)
616 no_splits = 1;
617
618 write_lock(&em_tree->lock);
619 em = lookup_extent_mapping(em_tree, start, len);
620 if (!em) {
621 write_unlock(&em_tree->lock);
622 break;
623 }
624 flags = em->flags;
625 gen = em->generation;
626 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
627 if (testend && em->start + em->len >= start + len) {
628 free_extent_map(em);
629 write_unlock(&em_tree->lock);
630 break;
631 }
632 start = em->start + em->len;
633 if (testend)
634 len = start + len - (em->start + em->len);
635 free_extent_map(em);
636 write_unlock(&em_tree->lock);
637 continue;
638 }
639 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
640 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
641 clear_bit(EXTENT_FLAG_LOGGING, &flags);
642 modified = !list_empty(&em->list);
643 if (no_splits)
644 goto next;
645
646 if (em->start < start) {
647 split->start = em->start;
648 split->len = start - em->start;
649
650 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
651 split->orig_start = em->orig_start;
652 split->block_start = em->block_start;
653
654 if (compressed)
655 split->block_len = em->block_len;
656 else
657 split->block_len = split->len;
658 split->orig_block_len = max(split->block_len,
659 em->orig_block_len);
660 split->ram_bytes = em->ram_bytes;
661 } else {
662 split->orig_start = split->start;
663 split->block_len = 0;
664 split->block_start = em->block_start;
665 split->orig_block_len = 0;
666 split->ram_bytes = split->len;
667 }
668
669 split->generation = gen;
670 split->bdev = em->bdev;
671 split->flags = flags;
672 split->compress_type = em->compress_type;
673 replace_extent_mapping(em_tree, em, split, modified);
674 free_extent_map(split);
675 split = split2;
676 split2 = NULL;
677 }
678 if (testend && em->start + em->len > start + len) {
679 u64 diff = start + len - em->start;
680
681 split->start = start + len;
682 split->len = em->start + em->len - (start + len);
683 split->bdev = em->bdev;
684 split->flags = flags;
685 split->compress_type = em->compress_type;
686 split->generation = gen;
687
688 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
689 split->orig_block_len = max(em->block_len,
690 em->orig_block_len);
691
692 split->ram_bytes = em->ram_bytes;
693 if (compressed) {
694 split->block_len = em->block_len;
695 split->block_start = em->block_start;
696 split->orig_start = em->orig_start;
697 } else {
698 split->block_len = split->len;
699 split->block_start = em->block_start
700 + diff;
701 split->orig_start = em->orig_start;
702 }
703 } else {
704 split->ram_bytes = split->len;
705 split->orig_start = split->start;
706 split->block_len = 0;
707 split->block_start = em->block_start;
708 split->orig_block_len = 0;
709 }
710
711 if (extent_map_in_tree(em)) {
712 replace_extent_mapping(em_tree, em, split,
713 modified);
714 } else {
715 ret = add_extent_mapping(em_tree, split,
716 modified);
717 ASSERT(ret == 0); /* Logic error */
718 }
719 free_extent_map(split);
720 split = NULL;
721 }
722next:
723 if (extent_map_in_tree(em))
724 remove_extent_mapping(em_tree, em);
725 write_unlock(&em_tree->lock);
726
727 /* once for us */
728 free_extent_map(em);
729 /* once for the tree*/
730 free_extent_map(em);
731 }
732 if (split)
733 free_extent_map(split);
734 if (split2)
735 free_extent_map(split2);
736}
737
738/*
739 * this is very complex, but the basic idea is to drop all extents
740 * in the range start - end. hint_block is filled in with a block number
741 * that would be a good hint to the block allocator for this file.
742 *
743 * If an extent intersects the range but is not entirely inside the range
744 * it is either truncated or split. Anything entirely inside the range
745 * is deleted from the tree.
746 */
747int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
748 struct btrfs_root *root, struct inode *inode,
749 struct btrfs_path *path, u64 start, u64 end,
750 u64 *drop_end, int drop_cache,
751 int replace_extent,
752 u32 extent_item_size,
753 int *key_inserted)
754{
755 struct btrfs_fs_info *fs_info = root->fs_info;
756 struct extent_buffer *leaf;
757 struct btrfs_file_extent_item *fi;
758 struct btrfs_ref ref = { 0 };
759 struct btrfs_key key;
760 struct btrfs_key new_key;
761 u64 ino = btrfs_ino(BTRFS_I(inode));
762 u64 search_start = start;
763 u64 disk_bytenr = 0;
764 u64 num_bytes = 0;
765 u64 extent_offset = 0;
766 u64 extent_end = 0;
767 u64 last_end = start;
768 int del_nr = 0;
769 int del_slot = 0;
770 int extent_type;
771 int recow;
772 int ret;
773 int modify_tree = -1;
774 int update_refs;
775 int found = 0;
776 int leafs_visited = 0;
777
778 if (drop_cache)
779 btrfs_drop_extent_cache(BTRFS_I(inode), start, end - 1, 0);
780
781 if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent)
782 modify_tree = 0;
783
784 update_refs = (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
785 root == fs_info->tree_root);
786 while (1) {
787 recow = 0;
788 ret = btrfs_lookup_file_extent(trans, root, path, ino,
789 search_start, modify_tree);
790 if (ret < 0)
791 break;
792 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
793 leaf = path->nodes[0];
794 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
795 if (key.objectid == ino &&
796 key.type == BTRFS_EXTENT_DATA_KEY)
797 path->slots[0]--;
798 }
799 ret = 0;
800 leafs_visited++;
801next_slot:
802 leaf = path->nodes[0];
803 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
804 BUG_ON(del_nr > 0);
805 ret = btrfs_next_leaf(root, path);
806 if (ret < 0)
807 break;
808 if (ret > 0) {
809 ret = 0;
810 break;
811 }
812 leafs_visited++;
813 leaf = path->nodes[0];
814 recow = 1;
815 }
816
817 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
818
819 if (key.objectid > ino)
820 break;
821 if (WARN_ON_ONCE(key.objectid < ino) ||
822 key.type < BTRFS_EXTENT_DATA_KEY) {
823 ASSERT(del_nr == 0);
824 path->slots[0]++;
825 goto next_slot;
826 }
827 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
828 break;
829
830 fi = btrfs_item_ptr(leaf, path->slots[0],
831 struct btrfs_file_extent_item);
832 extent_type = btrfs_file_extent_type(leaf, fi);
833
834 if (extent_type == BTRFS_FILE_EXTENT_REG ||
835 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
836 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
837 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
838 extent_offset = btrfs_file_extent_offset(leaf, fi);
839 extent_end = key.offset +
840 btrfs_file_extent_num_bytes(leaf, fi);
841 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
842 extent_end = key.offset +
843 btrfs_file_extent_ram_bytes(leaf, fi);
844 } else {
845 /* can't happen */
846 BUG();
847 }
848
849 /*
850 * Don't skip extent items representing 0 byte lengths. They
851 * used to be created (bug) if while punching holes we hit
852 * -ENOSPC condition. So if we find one here, just ensure we
853 * delete it, otherwise we would insert a new file extent item
854 * with the same key (offset) as that 0 bytes length file
855 * extent item in the call to setup_items_for_insert() later
856 * in this function.
857 */
858 if (extent_end == key.offset && extent_end >= search_start) {
859 last_end = extent_end;
860 goto delete_extent_item;
861 }
862
863 if (extent_end <= search_start) {
864 path->slots[0]++;
865 goto next_slot;
866 }
867
868 found = 1;
869 search_start = max(key.offset, start);
870 if (recow || !modify_tree) {
871 modify_tree = -1;
872 btrfs_release_path(path);
873 continue;
874 }
875
876 /*
877 * | - range to drop - |
878 * | -------- extent -------- |
879 */
880 if (start > key.offset && end < extent_end) {
881 BUG_ON(del_nr > 0);
882 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
883 ret = -EOPNOTSUPP;
884 break;
885 }
886
887 memcpy(&new_key, &key, sizeof(new_key));
888 new_key.offset = start;
889 ret = btrfs_duplicate_item(trans, root, path,
890 &new_key);
891 if (ret == -EAGAIN) {
892 btrfs_release_path(path);
893 continue;
894 }
895 if (ret < 0)
896 break;
897
898 leaf = path->nodes[0];
899 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
900 struct btrfs_file_extent_item);
901 btrfs_set_file_extent_num_bytes(leaf, fi,
902 start - key.offset);
903
904 fi = btrfs_item_ptr(leaf, path->slots[0],
905 struct btrfs_file_extent_item);
906
907 extent_offset += start - key.offset;
908 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
909 btrfs_set_file_extent_num_bytes(leaf, fi,
910 extent_end - start);
911 btrfs_mark_buffer_dirty(leaf);
912
913 if (update_refs && disk_bytenr > 0) {
914 btrfs_init_generic_ref(&ref,
915 BTRFS_ADD_DELAYED_REF,
916 disk_bytenr, num_bytes, 0);
917 btrfs_init_data_ref(&ref,
918 root->root_key.objectid,
919 new_key.objectid,
920 start - extent_offset);
921 ret = btrfs_inc_extent_ref(trans, &ref);
922 BUG_ON(ret); /* -ENOMEM */
923 }
924 key.offset = start;
925 }
926 /*
927 * From here on out we will have actually dropped something, so
928 * last_end can be updated.
929 */
930 last_end = extent_end;
931
932 /*
933 * | ---- range to drop ----- |
934 * | -------- extent -------- |
935 */
936 if (start <= key.offset && end < extent_end) {
937 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
938 ret = -EOPNOTSUPP;
939 break;
940 }
941
942 memcpy(&new_key, &key, sizeof(new_key));
943 new_key.offset = end;
944 btrfs_set_item_key_safe(fs_info, path, &new_key);
945
946 extent_offset += end - key.offset;
947 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
948 btrfs_set_file_extent_num_bytes(leaf, fi,
949 extent_end - end);
950 btrfs_mark_buffer_dirty(leaf);
951 if (update_refs && disk_bytenr > 0)
952 inode_sub_bytes(inode, end - key.offset);
953 break;
954 }
955
956 search_start = extent_end;
957 /*
958 * | ---- range to drop ----- |
959 * | -------- extent -------- |
960 */
961 if (start > key.offset && end >= extent_end) {
962 BUG_ON(del_nr > 0);
963 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
964 ret = -EOPNOTSUPP;
965 break;
966 }
967
968 btrfs_set_file_extent_num_bytes(leaf, fi,
969 start - key.offset);
970 btrfs_mark_buffer_dirty(leaf);
971 if (update_refs && disk_bytenr > 0)
972 inode_sub_bytes(inode, extent_end - start);
973 if (end == extent_end)
974 break;
975
976 path->slots[0]++;
977 goto next_slot;
978 }
979
980 /*
981 * | ---- range to drop ----- |
982 * | ------ extent ------ |
983 */
984 if (start <= key.offset && end >= extent_end) {
985delete_extent_item:
986 if (del_nr == 0) {
987 del_slot = path->slots[0];
988 del_nr = 1;
989 } else {
990 BUG_ON(del_slot + del_nr != path->slots[0]);
991 del_nr++;
992 }
993
994 if (update_refs &&
995 extent_type == BTRFS_FILE_EXTENT_INLINE) {
996 inode_sub_bytes(inode,
997 extent_end - key.offset);
998 extent_end = ALIGN(extent_end,
999 fs_info->sectorsize);
1000 } else if (update_refs && disk_bytenr > 0) {
1001 btrfs_init_generic_ref(&ref,
1002 BTRFS_DROP_DELAYED_REF,
1003 disk_bytenr, num_bytes, 0);
1004 btrfs_init_data_ref(&ref,
1005 root->root_key.objectid,
1006 key.objectid,
1007 key.offset - extent_offset);
1008 ret = btrfs_free_extent(trans, &ref);
1009 BUG_ON(ret); /* -ENOMEM */
1010 inode_sub_bytes(inode,
1011 extent_end - key.offset);
1012 }
1013
1014 if (end == extent_end)
1015 break;
1016
1017 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
1018 path->slots[0]++;
1019 goto next_slot;
1020 }
1021
1022 ret = btrfs_del_items(trans, root, path, del_slot,
1023 del_nr);
1024 if (ret) {
1025 btrfs_abort_transaction(trans, ret);
1026 break;
1027 }
1028
1029 del_nr = 0;
1030 del_slot = 0;
1031
1032 btrfs_release_path(path);
1033 continue;
1034 }
1035
1036 BUG();
1037 }
1038
1039 if (!ret && del_nr > 0) {
1040 /*
1041 * Set path->slots[0] to first slot, so that after the delete
1042 * if items are move off from our leaf to its immediate left or
1043 * right neighbor leafs, we end up with a correct and adjusted
1044 * path->slots[0] for our insertion (if replace_extent != 0).
1045 */
1046 path->slots[0] = del_slot;
1047 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1048 if (ret)
1049 btrfs_abort_transaction(trans, ret);
1050 }
1051
1052 leaf = path->nodes[0];
1053 /*
1054 * If btrfs_del_items() was called, it might have deleted a leaf, in
1055 * which case it unlocked our path, so check path->locks[0] matches a
1056 * write lock.
1057 */
1058 if (!ret && replace_extent && leafs_visited == 1 &&
1059 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
1060 path->locks[0] == BTRFS_WRITE_LOCK) &&
1061 btrfs_leaf_free_space(leaf) >=
1062 sizeof(struct btrfs_item) + extent_item_size) {
1063
1064 key.objectid = ino;
1065 key.type = BTRFS_EXTENT_DATA_KEY;
1066 key.offset = start;
1067 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
1068 struct btrfs_key slot_key;
1069
1070 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
1071 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
1072 path->slots[0]++;
1073 }
1074 setup_items_for_insert(root, path, &key,
1075 &extent_item_size,
1076 extent_item_size,
1077 sizeof(struct btrfs_item) +
1078 extent_item_size, 1);
1079 *key_inserted = 1;
1080 }
1081
1082 if (!replace_extent || !(*key_inserted))
1083 btrfs_release_path(path);
1084 if (drop_end)
1085 *drop_end = found ? min(end, last_end) : end;
1086 return ret;
1087}
1088
1089int btrfs_drop_extents(struct btrfs_trans_handle *trans,
1090 struct btrfs_root *root, struct inode *inode, u64 start,
1091 u64 end, int drop_cache)
1092{
1093 struct btrfs_path *path;
1094 int ret;
1095
1096 path = btrfs_alloc_path();
1097 if (!path)
1098 return -ENOMEM;
1099 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
1100 drop_cache, 0, 0, NULL);
1101 btrfs_free_path(path);
1102 return ret;
1103}
1104
1105static int extent_mergeable(struct extent_buffer *leaf, int slot,
1106 u64 objectid, u64 bytenr, u64 orig_offset,
1107 u64 *start, u64 *end)
1108{
1109 struct btrfs_file_extent_item *fi;
1110 struct btrfs_key key;
1111 u64 extent_end;
1112
1113 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1114 return 0;
1115
1116 btrfs_item_key_to_cpu(leaf, &key, slot);
1117 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1118 return 0;
1119
1120 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1121 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1122 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1123 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1124 btrfs_file_extent_compression(leaf, fi) ||
1125 btrfs_file_extent_encryption(leaf, fi) ||
1126 btrfs_file_extent_other_encoding(leaf, fi))
1127 return 0;
1128
1129 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1130 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1131 return 0;
1132
1133 *start = key.offset;
1134 *end = extent_end;
1135 return 1;
1136}
1137
1138/*
1139 * Mark extent in the range start - end as written.
1140 *
1141 * This changes extent type from 'pre-allocated' to 'regular'. If only
1142 * part of extent is marked as written, the extent will be split into
1143 * two or three.
1144 */
1145int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1146 struct btrfs_inode *inode, u64 start, u64 end)
1147{
1148 struct btrfs_fs_info *fs_info = trans->fs_info;
1149 struct btrfs_root *root = inode->root;
1150 struct extent_buffer *leaf;
1151 struct btrfs_path *path;
1152 struct btrfs_file_extent_item *fi;
1153 struct btrfs_ref ref = { 0 };
1154 struct btrfs_key key;
1155 struct btrfs_key new_key;
1156 u64 bytenr;
1157 u64 num_bytes;
1158 u64 extent_end;
1159 u64 orig_offset;
1160 u64 other_start;
1161 u64 other_end;
1162 u64 split;
1163 int del_nr = 0;
1164 int del_slot = 0;
1165 int recow;
1166 int ret;
1167 u64 ino = btrfs_ino(inode);
1168
1169 path = btrfs_alloc_path();
1170 if (!path)
1171 return -ENOMEM;
1172again:
1173 recow = 0;
1174 split = start;
1175 key.objectid = ino;
1176 key.type = BTRFS_EXTENT_DATA_KEY;
1177 key.offset = split;
1178
1179 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1180 if (ret < 0)
1181 goto out;
1182 if (ret > 0 && path->slots[0] > 0)
1183 path->slots[0]--;
1184
1185 leaf = path->nodes[0];
1186 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1187 if (key.objectid != ino ||
1188 key.type != BTRFS_EXTENT_DATA_KEY) {
1189 ret = -EINVAL;
1190 btrfs_abort_transaction(trans, ret);
1191 goto out;
1192 }
1193 fi = btrfs_item_ptr(leaf, path->slots[0],
1194 struct btrfs_file_extent_item);
1195 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) {
1196 ret = -EINVAL;
1197 btrfs_abort_transaction(trans, ret);
1198 goto out;
1199 }
1200 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1201 if (key.offset > start || extent_end < end) {
1202 ret = -EINVAL;
1203 btrfs_abort_transaction(trans, ret);
1204 goto out;
1205 }
1206
1207 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1208 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1209 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1210 memcpy(&new_key, &key, sizeof(new_key));
1211
1212 if (start == key.offset && end < extent_end) {
1213 other_start = 0;
1214 other_end = start;
1215 if (extent_mergeable(leaf, path->slots[0] - 1,
1216 ino, bytenr, orig_offset,
1217 &other_start, &other_end)) {
1218 new_key.offset = end;
1219 btrfs_set_item_key_safe(fs_info, path, &new_key);
1220 fi = btrfs_item_ptr(leaf, path->slots[0],
1221 struct btrfs_file_extent_item);
1222 btrfs_set_file_extent_generation(leaf, fi,
1223 trans->transid);
1224 btrfs_set_file_extent_num_bytes(leaf, fi,
1225 extent_end - end);
1226 btrfs_set_file_extent_offset(leaf, fi,
1227 end - orig_offset);
1228 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1229 struct btrfs_file_extent_item);
1230 btrfs_set_file_extent_generation(leaf, fi,
1231 trans->transid);
1232 btrfs_set_file_extent_num_bytes(leaf, fi,
1233 end - other_start);
1234 btrfs_mark_buffer_dirty(leaf);
1235 goto out;
1236 }
1237 }
1238
1239 if (start > key.offset && end == extent_end) {
1240 other_start = end;
1241 other_end = 0;
1242 if (extent_mergeable(leaf, path->slots[0] + 1,
1243 ino, bytenr, orig_offset,
1244 &other_start, &other_end)) {
1245 fi = btrfs_item_ptr(leaf, path->slots[0],
1246 struct btrfs_file_extent_item);
1247 btrfs_set_file_extent_num_bytes(leaf, fi,
1248 start - key.offset);
1249 btrfs_set_file_extent_generation(leaf, fi,
1250 trans->transid);
1251 path->slots[0]++;
1252 new_key.offset = start;
1253 btrfs_set_item_key_safe(fs_info, path, &new_key);
1254
1255 fi = btrfs_item_ptr(leaf, path->slots[0],
1256 struct btrfs_file_extent_item);
1257 btrfs_set_file_extent_generation(leaf, fi,
1258 trans->transid);
1259 btrfs_set_file_extent_num_bytes(leaf, fi,
1260 other_end - start);
1261 btrfs_set_file_extent_offset(leaf, fi,
1262 start - orig_offset);
1263 btrfs_mark_buffer_dirty(leaf);
1264 goto out;
1265 }
1266 }
1267
1268 while (start > key.offset || end < extent_end) {
1269 if (key.offset == start)
1270 split = end;
1271
1272 new_key.offset = split;
1273 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1274 if (ret == -EAGAIN) {
1275 btrfs_release_path(path);
1276 goto again;
1277 }
1278 if (ret < 0) {
1279 btrfs_abort_transaction(trans, ret);
1280 goto out;
1281 }
1282
1283 leaf = path->nodes[0];
1284 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1285 struct btrfs_file_extent_item);
1286 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1287 btrfs_set_file_extent_num_bytes(leaf, fi,
1288 split - key.offset);
1289
1290 fi = btrfs_item_ptr(leaf, path->slots[0],
1291 struct btrfs_file_extent_item);
1292
1293 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1294 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1295 btrfs_set_file_extent_num_bytes(leaf, fi,
1296 extent_end - split);
1297 btrfs_mark_buffer_dirty(leaf);
1298
1299 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, bytenr,
1300 num_bytes, 0);
1301 btrfs_init_data_ref(&ref, root->root_key.objectid, ino,
1302 orig_offset);
1303 ret = btrfs_inc_extent_ref(trans, &ref);
1304 if (ret) {
1305 btrfs_abort_transaction(trans, ret);
1306 goto out;
1307 }
1308
1309 if (split == start) {
1310 key.offset = start;
1311 } else {
1312 if (start != key.offset) {
1313 ret = -EINVAL;
1314 btrfs_abort_transaction(trans, ret);
1315 goto out;
1316 }
1317 path->slots[0]--;
1318 extent_end = end;
1319 }
1320 recow = 1;
1321 }
1322
1323 other_start = end;
1324 other_end = 0;
1325 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
1326 num_bytes, 0);
1327 btrfs_init_data_ref(&ref, root->root_key.objectid, ino, orig_offset);
1328 if (extent_mergeable(leaf, path->slots[0] + 1,
1329 ino, bytenr, orig_offset,
1330 &other_start, &other_end)) {
1331 if (recow) {
1332 btrfs_release_path(path);
1333 goto again;
1334 }
1335 extent_end = other_end;
1336 del_slot = path->slots[0] + 1;
1337 del_nr++;
1338 ret = btrfs_free_extent(trans, &ref);
1339 if (ret) {
1340 btrfs_abort_transaction(trans, ret);
1341 goto out;
1342 }
1343 }
1344 other_start = 0;
1345 other_end = start;
1346 if (extent_mergeable(leaf, path->slots[0] - 1,
1347 ino, bytenr, orig_offset,
1348 &other_start, &other_end)) {
1349 if (recow) {
1350 btrfs_release_path(path);
1351 goto again;
1352 }
1353 key.offset = other_start;
1354 del_slot = path->slots[0];
1355 del_nr++;
1356 ret = btrfs_free_extent(trans, &ref);
1357 if (ret) {
1358 btrfs_abort_transaction(trans, ret);
1359 goto out;
1360 }
1361 }
1362 if (del_nr == 0) {
1363 fi = btrfs_item_ptr(leaf, path->slots[0],
1364 struct btrfs_file_extent_item);
1365 btrfs_set_file_extent_type(leaf, fi,
1366 BTRFS_FILE_EXTENT_REG);
1367 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1368 btrfs_mark_buffer_dirty(leaf);
1369 } else {
1370 fi = btrfs_item_ptr(leaf, del_slot - 1,
1371 struct btrfs_file_extent_item);
1372 btrfs_set_file_extent_type(leaf, fi,
1373 BTRFS_FILE_EXTENT_REG);
1374 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1375 btrfs_set_file_extent_num_bytes(leaf, fi,
1376 extent_end - key.offset);
1377 btrfs_mark_buffer_dirty(leaf);
1378
1379 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1380 if (ret < 0) {
1381 btrfs_abort_transaction(trans, ret);
1382 goto out;
1383 }
1384 }
1385out:
1386 btrfs_free_path(path);
1387 return 0;
1388}
1389
1390/*
1391 * on error we return an unlocked page and the error value
1392 * on success we return a locked page and 0
1393 */
1394static int prepare_uptodate_page(struct inode *inode,
1395 struct page *page, u64 pos,
1396 bool force_uptodate)
1397{
1398 int ret = 0;
1399
1400 if (((pos & (PAGE_SIZE - 1)) || force_uptodate) &&
1401 !PageUptodate(page)) {
1402 ret = btrfs_readpage(NULL, page);
1403 if (ret)
1404 return ret;
1405 lock_page(page);
1406 if (!PageUptodate(page)) {
1407 unlock_page(page);
1408 return -EIO;
1409 }
1410 if (page->mapping != inode->i_mapping) {
1411 unlock_page(page);
1412 return -EAGAIN;
1413 }
1414 }
1415 return 0;
1416}
1417
1418/*
1419 * this just gets pages into the page cache and locks them down.
1420 */
1421static noinline int prepare_pages(struct inode *inode, struct page **pages,
1422 size_t num_pages, loff_t pos,
1423 size_t write_bytes, bool force_uptodate)
1424{
1425 int i;
1426 unsigned long index = pos >> PAGE_SHIFT;
1427 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1428 int err = 0;
1429 int faili;
1430
1431 for (i = 0; i < num_pages; i++) {
1432again:
1433 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1434 mask | __GFP_WRITE);
1435 if (!pages[i]) {
1436 faili = i - 1;
1437 err = -ENOMEM;
1438 goto fail;
1439 }
1440
1441 if (i == 0)
1442 err = prepare_uptodate_page(inode, pages[i], pos,
1443 force_uptodate);
1444 if (!err && i == num_pages - 1)
1445 err = prepare_uptodate_page(inode, pages[i],
1446 pos + write_bytes, false);
1447 if (err) {
1448 put_page(pages[i]);
1449 if (err == -EAGAIN) {
1450 err = 0;
1451 goto again;
1452 }
1453 faili = i - 1;
1454 goto fail;
1455 }
1456 wait_on_page_writeback(pages[i]);
1457 }
1458
1459 return 0;
1460fail:
1461 while (faili >= 0) {
1462 unlock_page(pages[faili]);
1463 put_page(pages[faili]);
1464 faili--;
1465 }
1466 return err;
1467
1468}
1469
1470/*
1471 * This function locks the extent and properly waits for data=ordered extents
1472 * to finish before allowing the pages to be modified if need.
1473 *
1474 * The return value:
1475 * 1 - the extent is locked
1476 * 0 - the extent is not locked, and everything is OK
1477 * -EAGAIN - need re-prepare the pages
1478 * the other < 0 number - Something wrong happens
1479 */
1480static noinline int
1481lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
1482 size_t num_pages, loff_t pos,
1483 size_t write_bytes,
1484 u64 *lockstart, u64 *lockend,
1485 struct extent_state **cached_state)
1486{
1487 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1488 u64 start_pos;
1489 u64 last_pos;
1490 int i;
1491 int ret = 0;
1492
1493 start_pos = round_down(pos, fs_info->sectorsize);
1494 last_pos = start_pos
1495 + round_up(pos + write_bytes - start_pos,
1496 fs_info->sectorsize) - 1;
1497
1498 if (start_pos < inode->vfs_inode.i_size) {
1499 struct btrfs_ordered_extent *ordered;
1500
1501 lock_extent_bits(&inode->io_tree, start_pos, last_pos,
1502 cached_state);
1503 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1504 last_pos - start_pos + 1);
1505 if (ordered &&
1506 ordered->file_offset + ordered->len > start_pos &&
1507 ordered->file_offset <= last_pos) {
1508 unlock_extent_cached(&inode->io_tree, start_pos,
1509 last_pos, cached_state);
1510 for (i = 0; i < num_pages; i++) {
1511 unlock_page(pages[i]);
1512 put_page(pages[i]);
1513 }
1514 btrfs_start_ordered_extent(&inode->vfs_inode,
1515 ordered, 1);
1516 btrfs_put_ordered_extent(ordered);
1517 return -EAGAIN;
1518 }
1519 if (ordered)
1520 btrfs_put_ordered_extent(ordered);
1521
1522 *lockstart = start_pos;
1523 *lockend = last_pos;
1524 ret = 1;
1525 }
1526
1527 /*
1528 * It's possible the pages are dirty right now, but we don't want
1529 * to clean them yet because copy_from_user may catch a page fault
1530 * and we might have to fall back to one page at a time. If that
1531 * happens, we'll unlock these pages and we'd have a window where
1532 * reclaim could sneak in and drop the once-dirty page on the floor
1533 * without writing it.
1534 *
1535 * We have the pages locked and the extent range locked, so there's
1536 * no way someone can start IO on any dirty pages in this range.
1537 *
1538 * We'll call btrfs_dirty_pages() later on, and that will flip around
1539 * delalloc bits and dirty the pages as required.
1540 */
1541 for (i = 0; i < num_pages; i++) {
1542 set_page_extent_mapped(pages[i]);
1543 WARN_ON(!PageLocked(pages[i]));
1544 }
1545
1546 return ret;
1547}
1548
1549static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
1550 size_t *write_bytes)
1551{
1552 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1553 struct btrfs_root *root = inode->root;
1554 u64 lockstart, lockend;
1555 u64 num_bytes;
1556 int ret;
1557
1558 ret = btrfs_start_write_no_snapshotting(root);
1559 if (!ret)
1560 return -EAGAIN;
1561
1562 lockstart = round_down(pos, fs_info->sectorsize);
1563 lockend = round_up(pos + *write_bytes,
1564 fs_info->sectorsize) - 1;
1565
1566 btrfs_lock_and_flush_ordered_range(&inode->io_tree, inode, lockstart,
1567 lockend, NULL);
1568
1569 num_bytes = lockend - lockstart + 1;
1570 ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
1571 NULL, NULL, NULL);
1572 if (ret <= 0) {
1573 ret = 0;
1574 btrfs_end_write_no_snapshotting(root);
1575 } else {
1576 *write_bytes = min_t(size_t, *write_bytes ,
1577 num_bytes - pos + lockstart);
1578 }
1579
1580 unlock_extent(&inode->io_tree, lockstart, lockend);
1581
1582 return ret;
1583}
1584
1585static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
1586 struct iov_iter *i)
1587{
1588 struct file *file = iocb->ki_filp;
1589 loff_t pos = iocb->ki_pos;
1590 struct inode *inode = file_inode(file);
1591 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1592 struct btrfs_root *root = BTRFS_I(inode)->root;
1593 struct page **pages = NULL;
1594 struct extent_changeset *data_reserved = NULL;
1595 u64 release_bytes = 0;
1596 u64 lockstart;
1597 u64 lockend;
1598 size_t num_written = 0;
1599 int nrptrs;
1600 int ret = 0;
1601 bool only_release_metadata = false;
1602 bool force_page_uptodate = false;
1603
1604 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
1605 PAGE_SIZE / (sizeof(struct page *)));
1606 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1607 nrptrs = max(nrptrs, 8);
1608 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1609 if (!pages)
1610 return -ENOMEM;
1611
1612 while (iov_iter_count(i) > 0) {
1613 struct extent_state *cached_state = NULL;
1614 size_t offset = offset_in_page(pos);
1615 size_t sector_offset;
1616 size_t write_bytes = min(iov_iter_count(i),
1617 nrptrs * (size_t)PAGE_SIZE -
1618 offset);
1619 size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
1620 PAGE_SIZE);
1621 size_t reserve_bytes;
1622 size_t dirty_pages;
1623 size_t copied;
1624 size_t dirty_sectors;
1625 size_t num_sectors;
1626 int extents_locked;
1627
1628 WARN_ON(num_pages > nrptrs);
1629
1630 /*
1631 * Fault pages before locking them in prepare_pages
1632 * to avoid recursive lock
1633 */
1634 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1635 ret = -EFAULT;
1636 break;
1637 }
1638
1639 sector_offset = pos & (fs_info->sectorsize - 1);
1640 reserve_bytes = round_up(write_bytes + sector_offset,
1641 fs_info->sectorsize);
1642
1643 extent_changeset_release(data_reserved);
1644 ret = btrfs_check_data_free_space(inode, &data_reserved, pos,
1645 write_bytes);
1646 if (ret < 0) {
1647 if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1648 BTRFS_INODE_PREALLOC)) &&
1649 check_can_nocow(BTRFS_I(inode), pos,
1650 &write_bytes) > 0) {
1651 /*
1652 * For nodata cow case, no need to reserve
1653 * data space.
1654 */
1655 only_release_metadata = true;
1656 /*
1657 * our prealloc extent may be smaller than
1658 * write_bytes, so scale down.
1659 */
1660 num_pages = DIV_ROUND_UP(write_bytes + offset,
1661 PAGE_SIZE);
1662 reserve_bytes = round_up(write_bytes +
1663 sector_offset,
1664 fs_info->sectorsize);
1665 } else {
1666 break;
1667 }
1668 }
1669
1670 WARN_ON(reserve_bytes == 0);
1671 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
1672 reserve_bytes);
1673 if (ret) {
1674 if (!only_release_metadata)
1675 btrfs_free_reserved_data_space(inode,
1676 data_reserved, pos,
1677 write_bytes);
1678 else
1679 btrfs_end_write_no_snapshotting(root);
1680 break;
1681 }
1682
1683 release_bytes = reserve_bytes;
1684again:
1685 /*
1686 * This is going to setup the pages array with the number of
1687 * pages we want, so we don't really need to worry about the
1688 * contents of pages from loop to loop
1689 */
1690 ret = prepare_pages(inode, pages, num_pages,
1691 pos, write_bytes,
1692 force_page_uptodate);
1693 if (ret) {
1694 btrfs_delalloc_release_extents(BTRFS_I(inode),
1695 reserve_bytes);
1696 break;
1697 }
1698
1699 extents_locked = lock_and_cleanup_extent_if_need(
1700 BTRFS_I(inode), pages,
1701 num_pages, pos, write_bytes, &lockstart,
1702 &lockend, &cached_state);
1703 if (extents_locked < 0) {
1704 if (extents_locked == -EAGAIN)
1705 goto again;
1706 btrfs_delalloc_release_extents(BTRFS_I(inode),
1707 reserve_bytes);
1708 ret = extents_locked;
1709 break;
1710 }
1711
1712 copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
1713
1714 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes);
1715 dirty_sectors = round_up(copied + sector_offset,
1716 fs_info->sectorsize);
1717 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors);
1718
1719 /*
1720 * if we have trouble faulting in the pages, fall
1721 * back to one page at a time
1722 */
1723 if (copied < write_bytes)
1724 nrptrs = 1;
1725
1726 if (copied == 0) {
1727 force_page_uptodate = true;
1728 dirty_sectors = 0;
1729 dirty_pages = 0;
1730 } else {
1731 force_page_uptodate = false;
1732 dirty_pages = DIV_ROUND_UP(copied + offset,
1733 PAGE_SIZE);
1734 }
1735
1736 if (num_sectors > dirty_sectors) {
1737 /* release everything except the sectors we dirtied */
1738 release_bytes -= dirty_sectors <<
1739 fs_info->sb->s_blocksize_bits;
1740 if (only_release_metadata) {
1741 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1742 release_bytes, true);
1743 } else {
1744 u64 __pos;
1745
1746 __pos = round_down(pos,
1747 fs_info->sectorsize) +
1748 (dirty_pages << PAGE_SHIFT);
1749 btrfs_delalloc_release_space(inode,
1750 data_reserved, __pos,
1751 release_bytes, true);
1752 }
1753 }
1754
1755 release_bytes = round_up(copied + sector_offset,
1756 fs_info->sectorsize);
1757
1758 if (copied > 0)
1759 ret = btrfs_dirty_pages(inode, pages, dirty_pages,
1760 pos, copied, &cached_state);
1761
1762 /*
1763 * If we have not locked the extent range, because the range's
1764 * start offset is >= i_size, we might still have a non-NULL
1765 * cached extent state, acquired while marking the extent range
1766 * as delalloc through btrfs_dirty_pages(). Therefore free any
1767 * possible cached extent state to avoid a memory leak.
1768 */
1769 if (extents_locked)
1770 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1771 lockstart, lockend, &cached_state);
1772 else
1773 free_extent_state(cached_state);
1774
1775 btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes);
1776 if (ret) {
1777 btrfs_drop_pages(pages, num_pages);
1778 break;
1779 }
1780
1781 release_bytes = 0;
1782 if (only_release_metadata)
1783 btrfs_end_write_no_snapshotting(root);
1784
1785 if (only_release_metadata && copied > 0) {
1786 lockstart = round_down(pos,
1787 fs_info->sectorsize);
1788 lockend = round_up(pos + copied,
1789 fs_info->sectorsize) - 1;
1790
1791 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1792 lockend, EXTENT_NORESERVE, NULL,
1793 NULL, GFP_NOFS);
1794 only_release_metadata = false;
1795 }
1796
1797 btrfs_drop_pages(pages, num_pages);
1798
1799 cond_resched();
1800
1801 balance_dirty_pages_ratelimited(inode->i_mapping);
1802 if (dirty_pages < (fs_info->nodesize >> PAGE_SHIFT) + 1)
1803 btrfs_btree_balance_dirty(fs_info);
1804
1805 pos += copied;
1806 num_written += copied;
1807 }
1808
1809 kfree(pages);
1810
1811 if (release_bytes) {
1812 if (only_release_metadata) {
1813 btrfs_end_write_no_snapshotting(root);
1814 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1815 release_bytes, true);
1816 } else {
1817 btrfs_delalloc_release_space(inode, data_reserved,
1818 round_down(pos, fs_info->sectorsize),
1819 release_bytes, true);
1820 }
1821 }
1822
1823 extent_changeset_free(data_reserved);
1824 return num_written ? num_written : ret;
1825}
1826
1827static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
1828{
1829 struct file *file = iocb->ki_filp;
1830 struct inode *inode = file_inode(file);
1831 loff_t pos;
1832 ssize_t written;
1833 ssize_t written_buffered;
1834 loff_t endbyte;
1835 int err;
1836
1837 written = generic_file_direct_write(iocb, from);
1838
1839 if (written < 0 || !iov_iter_count(from))
1840 return written;
1841
1842 pos = iocb->ki_pos;
1843 written_buffered = btrfs_buffered_write(iocb, from);
1844 if (written_buffered < 0) {
1845 err = written_buffered;
1846 goto out;
1847 }
1848 /*
1849 * Ensure all data is persisted. We want the next direct IO read to be
1850 * able to read what was just written.
1851 */
1852 endbyte = pos + written_buffered - 1;
1853 err = btrfs_fdatawrite_range(inode, pos, endbyte);
1854 if (err)
1855 goto out;
1856 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
1857 if (err)
1858 goto out;
1859 written += written_buffered;
1860 iocb->ki_pos = pos + written_buffered;
1861 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
1862 endbyte >> PAGE_SHIFT);
1863out:
1864 return written ? written : err;
1865}
1866
1867static void update_time_for_write(struct inode *inode)
1868{
1869 struct timespec64 now;
1870
1871 if (IS_NOCMTIME(inode))
1872 return;
1873
1874 now = current_time(inode);
1875 if (!timespec64_equal(&inode->i_mtime, &now))
1876 inode->i_mtime = now;
1877
1878 if (!timespec64_equal(&inode->i_ctime, &now))
1879 inode->i_ctime = now;
1880
1881 if (IS_I_VERSION(inode))
1882 inode_inc_iversion(inode);
1883}
1884
1885static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1886 struct iov_iter *from)
1887{
1888 struct file *file = iocb->ki_filp;
1889 struct inode *inode = file_inode(file);
1890 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1891 struct btrfs_root *root = BTRFS_I(inode)->root;
1892 u64 start_pos;
1893 u64 end_pos;
1894 ssize_t num_written = 0;
1895 const bool sync = iocb->ki_flags & IOCB_DSYNC;
1896 ssize_t err;
1897 loff_t pos;
1898 size_t count;
1899 loff_t oldsize;
1900 int clean_page = 0;
1901
1902 if (!(iocb->ki_flags & IOCB_DIRECT) &&
1903 (iocb->ki_flags & IOCB_NOWAIT))
1904 return -EOPNOTSUPP;
1905
1906 if (!inode_trylock(inode)) {
1907 if (iocb->ki_flags & IOCB_NOWAIT)
1908 return -EAGAIN;
1909 inode_lock(inode);
1910 }
1911
1912 err = generic_write_checks(iocb, from);
1913 if (err <= 0) {
1914 inode_unlock(inode);
1915 return err;
1916 }
1917
1918 pos = iocb->ki_pos;
1919 count = iov_iter_count(from);
1920 if (iocb->ki_flags & IOCB_NOWAIT) {
1921 /*
1922 * We will allocate space in case nodatacow is not set,
1923 * so bail
1924 */
1925 if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1926 BTRFS_INODE_PREALLOC)) ||
1927 check_can_nocow(BTRFS_I(inode), pos, &count) <= 0) {
1928 inode_unlock(inode);
1929 return -EAGAIN;
1930 }
1931 }
1932
1933 current->backing_dev_info = inode_to_bdi(inode);
1934 err = file_remove_privs(file);
1935 if (err) {
1936 inode_unlock(inode);
1937 goto out;
1938 }
1939
1940 /*
1941 * If BTRFS flips readonly due to some impossible error
1942 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1943 * although we have opened a file as writable, we have
1944 * to stop this write operation to ensure FS consistency.
1945 */
1946 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1947 inode_unlock(inode);
1948 err = -EROFS;
1949 goto out;
1950 }
1951
1952 /*
1953 * We reserve space for updating the inode when we reserve space for the
1954 * extent we are going to write, so we will enospc out there. We don't
1955 * need to start yet another transaction to update the inode as we will
1956 * update the inode when we finish writing whatever data we write.
1957 */
1958 update_time_for_write(inode);
1959
1960 start_pos = round_down(pos, fs_info->sectorsize);
1961 oldsize = i_size_read(inode);
1962 if (start_pos > oldsize) {
1963 /* Expand hole size to cover write data, preventing empty gap */
1964 end_pos = round_up(pos + count,
1965 fs_info->sectorsize);
1966 err = btrfs_cont_expand(inode, oldsize, end_pos);
1967 if (err) {
1968 inode_unlock(inode);
1969 goto out;
1970 }
1971 if (start_pos > round_up(oldsize, fs_info->sectorsize))
1972 clean_page = 1;
1973 }
1974
1975 if (sync)
1976 atomic_inc(&BTRFS_I(inode)->sync_writers);
1977
1978 if (iocb->ki_flags & IOCB_DIRECT) {
1979 num_written = __btrfs_direct_write(iocb, from);
1980 } else {
1981 num_written = btrfs_buffered_write(iocb, from);
1982 if (num_written > 0)
1983 iocb->ki_pos = pos + num_written;
1984 if (clean_page)
1985 pagecache_isize_extended(inode, oldsize,
1986 i_size_read(inode));
1987 }
1988
1989 inode_unlock(inode);
1990
1991 /*
1992 * We also have to set last_sub_trans to the current log transid,
1993 * otherwise subsequent syncs to a file that's been synced in this
1994 * transaction will appear to have already occurred.
1995 */
1996 spin_lock(&BTRFS_I(inode)->lock);
1997 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1998 spin_unlock(&BTRFS_I(inode)->lock);
1999 if (num_written > 0)
2000 num_written = generic_write_sync(iocb, num_written);
2001
2002 if (sync)
2003 atomic_dec(&BTRFS_I(inode)->sync_writers);
2004out:
2005 current->backing_dev_info = NULL;
2006 return num_written ? num_written : err;
2007}
2008
2009int btrfs_release_file(struct inode *inode, struct file *filp)
2010{
2011 struct btrfs_file_private *private = filp->private_data;
2012
2013 if (private && private->filldir_buf)
2014 kfree(private->filldir_buf);
2015 kfree(private);
2016 filp->private_data = NULL;
2017
2018 /*
2019 * ordered_data_close is set by setattr when we are about to truncate
2020 * a file from a non-zero size to a zero size. This tries to
2021 * flush down new bytes that may have been written if the
2022 * application were using truncate to replace a file in place.
2023 */
2024 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
2025 &BTRFS_I(inode)->runtime_flags))
2026 filemap_flush(inode->i_mapping);
2027 return 0;
2028}
2029
2030static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
2031{
2032 int ret;
2033 struct blk_plug plug;
2034
2035 /*
2036 * This is only called in fsync, which would do synchronous writes, so
2037 * a plug can merge adjacent IOs as much as possible. Esp. in case of
2038 * multiple disks using raid profile, a large IO can be split to
2039 * several segments of stripe length (currently 64K).
2040 */
2041 blk_start_plug(&plug);
2042 atomic_inc(&BTRFS_I(inode)->sync_writers);
2043 ret = btrfs_fdatawrite_range(inode, start, end);
2044 atomic_dec(&BTRFS_I(inode)->sync_writers);
2045 blk_finish_plug(&plug);
2046
2047 return ret;
2048}
2049
2050/*
2051 * fsync call for both files and directories. This logs the inode into
2052 * the tree log instead of forcing full commits whenever possible.
2053 *
2054 * It needs to call filemap_fdatawait so that all ordered extent updates are
2055 * in the metadata btree are up to date for copying to the log.
2056 *
2057 * It drops the inode mutex before doing the tree log commit. This is an
2058 * important optimization for directories because holding the mutex prevents
2059 * new operations on the dir while we write to disk.
2060 */
2061int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
2062{
2063 struct dentry *dentry = file_dentry(file);
2064 struct inode *inode = d_inode(dentry);
2065 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2066 struct btrfs_root *root = BTRFS_I(inode)->root;
2067 struct btrfs_trans_handle *trans;
2068 struct btrfs_log_ctx ctx;
2069 int ret = 0, err;
2070
2071 trace_btrfs_sync_file(file, datasync);
2072
2073 btrfs_init_log_ctx(&ctx, inode);
2074
2075 /*
2076 * We write the dirty pages in the range and wait until they complete
2077 * out of the ->i_mutex. If so, we can flush the dirty pages by
2078 * multi-task, and make the performance up. See
2079 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
2080 */
2081 ret = start_ordered_ops(inode, start, end);
2082 if (ret)
2083 goto out;
2084
2085 inode_lock(inode);
2086
2087 /*
2088 * We take the dio_sem here because the tree log stuff can race with
2089 * lockless dio writes and get an extent map logged for an extent we
2090 * never waited on. We need it this high up for lockdep reasons.
2091 */
2092 down_write(&BTRFS_I(inode)->dio_sem);
2093
2094 atomic_inc(&root->log_batch);
2095
2096 /*
2097 * If the inode needs a full sync, make sure we use a full range to
2098 * avoid log tree corruption, due to hole detection racing with ordered
2099 * extent completion for adjacent ranges, and assertion failures during
2100 * hole detection. Do this while holding the inode lock, to avoid races
2101 * with other tasks.
2102 */
2103 if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2104 &BTRFS_I(inode)->runtime_flags)) {
2105 start = 0;
2106 end = LLONG_MAX;
2107 }
2108
2109 /*
2110 * Before we acquired the inode's lock, someone may have dirtied more
2111 * pages in the target range. We need to make sure that writeback for
2112 * any such pages does not start while we are logging the inode, because
2113 * if it does, any of the following might happen when we are not doing a
2114 * full inode sync:
2115 *
2116 * 1) We log an extent after its writeback finishes but before its
2117 * checksums are added to the csum tree, leading to -EIO errors
2118 * when attempting to read the extent after a log replay.
2119 *
2120 * 2) We can end up logging an extent before its writeback finishes.
2121 * Therefore after the log replay we will have a file extent item
2122 * pointing to an unwritten extent (and no data checksums as well).
2123 *
2124 * So trigger writeback for any eventual new dirty pages and then we
2125 * wait for all ordered extents to complete below.
2126 */
2127 ret = start_ordered_ops(inode, start, end);
2128 if (ret) {
2129 inode_unlock(inode);
2130 goto out;
2131 }
2132
2133 /*
2134 * We have to do this here to avoid the priority inversion of waiting on
2135 * IO of a lower priority task while holding a transaction open.
2136 *
2137 * Also, the range length can be represented by u64, we have to do the
2138 * typecasts to avoid signed overflow if it's [0, LLONG_MAX].
2139 */
2140 ret = btrfs_wait_ordered_range(inode, start, (u64)end - (u64)start + 1);
2141 if (ret) {
2142 up_write(&BTRFS_I(inode)->dio_sem);
2143 inode_unlock(inode);
2144 goto out;
2145 }
2146 atomic_inc(&root->log_batch);
2147
2148 smp_mb();
2149 if (btrfs_inode_in_log(BTRFS_I(inode), fs_info->generation) ||
2150 BTRFS_I(inode)->last_trans <= fs_info->last_trans_committed) {
2151 /*
2152 * We've had everything committed since the last time we were
2153 * modified so clear this flag in case it was set for whatever
2154 * reason, it's no longer relevant.
2155 */
2156 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2157 &BTRFS_I(inode)->runtime_flags);
2158 /*
2159 * An ordered extent might have started before and completed
2160 * already with io errors, in which case the inode was not
2161 * updated and we end up here. So check the inode's mapping
2162 * for any errors that might have happened since we last
2163 * checked called fsync.
2164 */
2165 ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err);
2166 up_write(&BTRFS_I(inode)->dio_sem);
2167 inode_unlock(inode);
2168 goto out;
2169 }
2170
2171 /*
2172 * We use start here because we will need to wait on the IO to complete
2173 * in btrfs_sync_log, which could require joining a transaction (for
2174 * example checking cross references in the nocow path). If we use join
2175 * here we could get into a situation where we're waiting on IO to
2176 * happen that is blocked on a transaction trying to commit. With start
2177 * we inc the extwriter counter, so we wait for all extwriters to exit
2178 * before we start blocking joiners. This comment is to keep somebody
2179 * from thinking they are super smart and changing this to
2180 * btrfs_join_transaction *cough*Josef*cough*.
2181 */
2182 trans = btrfs_start_transaction(root, 0);
2183 if (IS_ERR(trans)) {
2184 ret = PTR_ERR(trans);
2185 up_write(&BTRFS_I(inode)->dio_sem);
2186 inode_unlock(inode);
2187 goto out;
2188 }
2189
2190 ret = btrfs_log_dentry_safe(trans, dentry, start, end, &ctx);
2191 if (ret < 0) {
2192 /* Fallthrough and commit/free transaction. */
2193 ret = 1;
2194 }
2195
2196 /* we've logged all the items and now have a consistent
2197 * version of the file in the log. It is possible that
2198 * someone will come in and modify the file, but that's
2199 * fine because the log is consistent on disk, and we
2200 * have references to all of the file's extents
2201 *
2202 * It is possible that someone will come in and log the
2203 * file again, but that will end up using the synchronization
2204 * inside btrfs_sync_log to keep things safe.
2205 */
2206 up_write(&BTRFS_I(inode)->dio_sem);
2207 inode_unlock(inode);
2208
2209 if (ret != BTRFS_NO_LOG_SYNC) {
2210 if (!ret) {
2211 ret = btrfs_sync_log(trans, root, &ctx);
2212 if (!ret) {
2213 ret = btrfs_end_transaction(trans);
2214 goto out;
2215 }
2216 }
2217 ret = btrfs_commit_transaction(trans);
2218 } else {
2219 ret = btrfs_end_transaction(trans);
2220 }
2221out:
2222 ASSERT(list_empty(&ctx.list));
2223 err = file_check_and_advance_wb_err(file);
2224 if (!ret)
2225 ret = err;
2226 return ret > 0 ? -EIO : ret;
2227}
2228
2229static const struct vm_operations_struct btrfs_file_vm_ops = {
2230 .fault = filemap_fault,
2231 .map_pages = filemap_map_pages,
2232 .page_mkwrite = btrfs_page_mkwrite,
2233};
2234
2235static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2236{
2237 struct address_space *mapping = filp->f_mapping;
2238
2239 if (!mapping->a_ops->readpage)
2240 return -ENOEXEC;
2241
2242 file_accessed(filp);
2243 vma->vm_ops = &btrfs_file_vm_ops;
2244
2245 return 0;
2246}
2247
2248static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf,
2249 int slot, u64 start, u64 end)
2250{
2251 struct btrfs_file_extent_item *fi;
2252 struct btrfs_key key;
2253
2254 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2255 return 0;
2256
2257 btrfs_item_key_to_cpu(leaf, &key, slot);
2258 if (key.objectid != btrfs_ino(inode) ||
2259 key.type != BTRFS_EXTENT_DATA_KEY)
2260 return 0;
2261
2262 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2263
2264 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2265 return 0;
2266
2267 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2268 return 0;
2269
2270 if (key.offset == end)
2271 return 1;
2272 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2273 return 1;
2274 return 0;
2275}
2276
2277static int fill_holes(struct btrfs_trans_handle *trans,
2278 struct btrfs_inode *inode,
2279 struct btrfs_path *path, u64 offset, u64 end)
2280{
2281 struct btrfs_fs_info *fs_info = trans->fs_info;
2282 struct btrfs_root *root = inode->root;
2283 struct extent_buffer *leaf;
2284 struct btrfs_file_extent_item *fi;
2285 struct extent_map *hole_em;
2286 struct extent_map_tree *em_tree = &inode->extent_tree;
2287 struct btrfs_key key;
2288 int ret;
2289
2290 if (btrfs_fs_incompat(fs_info, NO_HOLES))
2291 goto out;
2292
2293 key.objectid = btrfs_ino(inode);
2294 key.type = BTRFS_EXTENT_DATA_KEY;
2295 key.offset = offset;
2296
2297 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2298 if (ret <= 0) {
2299 /*
2300 * We should have dropped this offset, so if we find it then
2301 * something has gone horribly wrong.
2302 */
2303 if (ret == 0)
2304 ret = -EINVAL;
2305 return ret;
2306 }
2307
2308 leaf = path->nodes[0];
2309 if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) {
2310 u64 num_bytes;
2311
2312 path->slots[0]--;
2313 fi = btrfs_item_ptr(leaf, path->slots[0],
2314 struct btrfs_file_extent_item);
2315 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2316 end - offset;
2317 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2318 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2319 btrfs_set_file_extent_offset(leaf, fi, 0);
2320 btrfs_mark_buffer_dirty(leaf);
2321 goto out;
2322 }
2323
2324 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2325 u64 num_bytes;
2326
2327 key.offset = offset;
2328 btrfs_set_item_key_safe(fs_info, path, &key);
2329 fi = btrfs_item_ptr(leaf, path->slots[0],
2330 struct btrfs_file_extent_item);
2331 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2332 offset;
2333 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2334 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2335 btrfs_set_file_extent_offset(leaf, fi, 0);
2336 btrfs_mark_buffer_dirty(leaf);
2337 goto out;
2338 }
2339 btrfs_release_path(path);
2340
2341 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode),
2342 offset, 0, 0, end - offset, 0, end - offset, 0, 0, 0);
2343 if (ret)
2344 return ret;
2345
2346out:
2347 btrfs_release_path(path);
2348
2349 hole_em = alloc_extent_map();
2350 if (!hole_em) {
2351 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2352 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
2353 } else {
2354 hole_em->start = offset;
2355 hole_em->len = end - offset;
2356 hole_em->ram_bytes = hole_em->len;
2357 hole_em->orig_start = offset;
2358
2359 hole_em->block_start = EXTENT_MAP_HOLE;
2360 hole_em->block_len = 0;
2361 hole_em->orig_block_len = 0;
2362 hole_em->bdev = fs_info->fs_devices->latest_bdev;
2363 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2364 hole_em->generation = trans->transid;
2365
2366 do {
2367 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2368 write_lock(&em_tree->lock);
2369 ret = add_extent_mapping(em_tree, hole_em, 1);
2370 write_unlock(&em_tree->lock);
2371 } while (ret == -EEXIST);
2372 free_extent_map(hole_em);
2373 if (ret)
2374 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2375 &inode->runtime_flags);
2376 }
2377
2378 return 0;
2379}
2380
2381/*
2382 * Find a hole extent on given inode and change start/len to the end of hole
2383 * extent.(hole/vacuum extent whose em->start <= start &&
2384 * em->start + em->len > start)
2385 * When a hole extent is found, return 1 and modify start/len.
2386 */
2387static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)
2388{
2389 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2390 struct extent_map *em;
2391 int ret = 0;
2392
2393 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2394 round_down(*start, fs_info->sectorsize),
2395 round_up(*len, fs_info->sectorsize), 0);
2396 if (IS_ERR(em))
2397 return PTR_ERR(em);
2398
2399 /* Hole or vacuum extent(only exists in no-hole mode) */
2400 if (em->block_start == EXTENT_MAP_HOLE) {
2401 ret = 1;
2402 *len = em->start + em->len > *start + *len ?
2403 0 : *start + *len - em->start - em->len;
2404 *start = em->start + em->len;
2405 }
2406 free_extent_map(em);
2407 return ret;
2408}
2409
2410static int btrfs_punch_hole_lock_range(struct inode *inode,
2411 const u64 lockstart,
2412 const u64 lockend,
2413 struct extent_state **cached_state)
2414{
2415 while (1) {
2416 struct btrfs_ordered_extent *ordered;
2417 int ret;
2418
2419 truncate_pagecache_range(inode, lockstart, lockend);
2420
2421 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2422 cached_state);
2423 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2424
2425 /*
2426 * We need to make sure we have no ordered extents in this range
2427 * and nobody raced in and read a page in this range, if we did
2428 * we need to try again.
2429 */
2430 if ((!ordered ||
2431 (ordered->file_offset + ordered->len <= lockstart ||
2432 ordered->file_offset > lockend)) &&
2433 !filemap_range_has_page(inode->i_mapping,
2434 lockstart, lockend)) {
2435 if (ordered)
2436 btrfs_put_ordered_extent(ordered);
2437 break;
2438 }
2439 if (ordered)
2440 btrfs_put_ordered_extent(ordered);
2441 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2442 lockend, cached_state);
2443 ret = btrfs_wait_ordered_range(inode, lockstart,
2444 lockend - lockstart + 1);
2445 if (ret)
2446 return ret;
2447 }
2448 return 0;
2449}
2450
2451static int btrfs_insert_clone_extent(struct btrfs_trans_handle *trans,
2452 struct inode *inode,
2453 struct btrfs_path *path,
2454 struct btrfs_clone_extent_info *clone_info,
2455 const u64 clone_len)
2456{
2457 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2458 struct btrfs_root *root = BTRFS_I(inode)->root;
2459 struct btrfs_file_extent_item *extent;
2460 struct extent_buffer *leaf;
2461 struct btrfs_key key;
2462 int slot;
2463 struct btrfs_ref ref = { 0 };
2464 u64 ref_offset;
2465 int ret;
2466
2467 if (clone_len == 0)
2468 return 0;
2469
2470 if (clone_info->disk_offset == 0 &&
2471 btrfs_fs_incompat(fs_info, NO_HOLES))
2472 return 0;
2473
2474 key.objectid = btrfs_ino(BTRFS_I(inode));
2475 key.type = BTRFS_EXTENT_DATA_KEY;
2476 key.offset = clone_info->file_offset;
2477 ret = btrfs_insert_empty_item(trans, root, path, &key,
2478 clone_info->item_size);
2479 if (ret)
2480 return ret;
2481 leaf = path->nodes[0];
2482 slot = path->slots[0];
2483 write_extent_buffer(leaf, clone_info->extent_buf,
2484 btrfs_item_ptr_offset(leaf, slot),
2485 clone_info->item_size);
2486 extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2487 btrfs_set_file_extent_offset(leaf, extent, clone_info->data_offset);
2488 btrfs_set_file_extent_num_bytes(leaf, extent, clone_len);
2489 btrfs_mark_buffer_dirty(leaf);
2490 btrfs_release_path(path);
2491
2492 /* If it's a hole, nothing more needs to be done. */
2493 if (clone_info->disk_offset == 0)
2494 return 0;
2495
2496 inode_add_bytes(inode, clone_len);
2497 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF,
2498 clone_info->disk_offset,
2499 clone_info->disk_len, 0);
2500 ref_offset = clone_info->file_offset - clone_info->data_offset;
2501 btrfs_init_data_ref(&ref, root->root_key.objectid,
2502 btrfs_ino(BTRFS_I(inode)), ref_offset);
2503 ret = btrfs_inc_extent_ref(trans, &ref);
2504
2505 return ret;
2506}
2507
2508/*
2509 * The respective range must have been previously locked, as well as the inode.
2510 * The end offset is inclusive (last byte of the range).
2511 * @clone_info is NULL for fallocate's hole punching and non-NULL for extent
2512 * cloning.
2513 * When cloning, we don't want to end up in a state where we dropped extents
2514 * without inserting a new one, so we must abort the transaction to avoid a
2515 * corruption.
2516 */
2517int btrfs_punch_hole_range(struct inode *inode, struct btrfs_path *path,
2518 const u64 start, const u64 end,
2519 struct btrfs_clone_extent_info *clone_info,
2520 struct btrfs_trans_handle **trans_out)
2521{
2522 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2523 u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1);
2524 u64 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2525 struct btrfs_root *root = BTRFS_I(inode)->root;
2526 struct btrfs_trans_handle *trans = NULL;
2527 struct btrfs_block_rsv *rsv;
2528 unsigned int rsv_count;
2529 u64 cur_offset;
2530 u64 drop_end;
2531 u64 len = end - start;
2532 int ret = 0;
2533
2534 if (end <= start)
2535 return -EINVAL;
2536
2537 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
2538 if (!rsv) {
2539 ret = -ENOMEM;
2540 goto out;
2541 }
2542 rsv->size = btrfs_calc_insert_metadata_size(fs_info, 1);
2543 rsv->failfast = 1;
2544
2545 /*
2546 * 1 - update the inode
2547 * 1 - removing the extents in the range
2548 * 1 - adding the hole extent if no_holes isn't set or if we are cloning
2549 * an extent
2550 */
2551 if (!btrfs_fs_incompat(fs_info, NO_HOLES) || clone_info)
2552 rsv_count = 3;
2553 else
2554 rsv_count = 2;
2555
2556 trans = btrfs_start_transaction(root, rsv_count);
2557 if (IS_ERR(trans)) {
2558 ret = PTR_ERR(trans);
2559 trans = NULL;
2560 goto out_free;
2561 }
2562
2563 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
2564 min_size, false);
2565 BUG_ON(ret);
2566 trans->block_rsv = rsv;
2567
2568 cur_offset = start;
2569 while (cur_offset < end) {
2570 ret = __btrfs_drop_extents(trans, root, inode, path,
2571 cur_offset, end + 1, &drop_end,
2572 1, 0, 0, NULL);
2573 if (ret != -ENOSPC) {
2574 /*
2575 * When cloning we want to avoid transaction aborts when
2576 * nothing was done and we are attempting to clone parts
2577 * of inline extents, in such cases -EOPNOTSUPP is
2578 * returned by __btrfs_drop_extents() without having
2579 * changed anything in the file.
2580 */
2581 if (clone_info && ret && ret != -EOPNOTSUPP)
2582 btrfs_abort_transaction(trans, ret);
2583 break;
2584 }
2585
2586 trans->block_rsv = &fs_info->trans_block_rsv;
2587
2588 if (!clone_info && cur_offset < drop_end &&
2589 cur_offset < ino_size) {
2590 ret = fill_holes(trans, BTRFS_I(inode), path,
2591 cur_offset, drop_end);
2592 if (ret) {
2593 /*
2594 * If we failed then we didn't insert our hole
2595 * entries for the area we dropped, so now the
2596 * fs is corrupted, so we must abort the
2597 * transaction.
2598 */
2599 btrfs_abort_transaction(trans, ret);
2600 break;
2601 }
2602 }
2603
2604 if (clone_info) {
2605 u64 clone_len = drop_end - cur_offset;
2606
2607 ret = btrfs_insert_clone_extent(trans, inode, path,
2608 clone_info, clone_len);
2609 if (ret) {
2610 btrfs_abort_transaction(trans, ret);
2611 break;
2612 }
2613 clone_info->data_len -= clone_len;
2614 clone_info->data_offset += clone_len;
2615 clone_info->file_offset += clone_len;
2616 }
2617
2618 cur_offset = drop_end;
2619
2620 ret = btrfs_update_inode(trans, root, inode);
2621 if (ret)
2622 break;
2623
2624 btrfs_end_transaction(trans);
2625 btrfs_btree_balance_dirty(fs_info);
2626
2627 trans = btrfs_start_transaction(root, rsv_count);
2628 if (IS_ERR(trans)) {
2629 ret = PTR_ERR(trans);
2630 trans = NULL;
2631 break;
2632 }
2633
2634 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
2635 rsv, min_size, false);
2636 BUG_ON(ret); /* shouldn't happen */
2637 trans->block_rsv = rsv;
2638
2639 if (!clone_info) {
2640 ret = find_first_non_hole(inode, &cur_offset, &len);
2641 if (unlikely(ret < 0))
2642 break;
2643 if (ret && !len) {
2644 ret = 0;
2645 break;
2646 }
2647 }
2648 }
2649
2650 /*
2651 * If we were cloning, force the next fsync to be a full one since we
2652 * we replaced (or just dropped in the case of cloning holes when
2653 * NO_HOLES is enabled) extents and extent maps.
2654 * This is for the sake of simplicity, and cloning into files larger
2655 * than 16Mb would force the full fsync any way (when
2656 * try_release_extent_mapping() is invoked during page cache truncation.
2657 */
2658 if (clone_info)
2659 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2660 &BTRFS_I(inode)->runtime_flags);
2661
2662 if (ret)
2663 goto out_trans;
2664
2665 trans->block_rsv = &fs_info->trans_block_rsv;
2666 /*
2667 * If we are using the NO_HOLES feature we might have had already an
2668 * hole that overlaps a part of the region [lockstart, lockend] and
2669 * ends at (or beyond) lockend. Since we have no file extent items to
2670 * represent holes, drop_end can be less than lockend and so we must
2671 * make sure we have an extent map representing the existing hole (the
2672 * call to __btrfs_drop_extents() might have dropped the existing extent
2673 * map representing the existing hole), otherwise the fast fsync path
2674 * will not record the existence of the hole region
2675 * [existing_hole_start, lockend].
2676 */
2677 if (drop_end <= end)
2678 drop_end = end + 1;
2679 /*
2680 * Don't insert file hole extent item if it's for a range beyond eof
2681 * (because it's useless) or if it represents a 0 bytes range (when
2682 * cur_offset == drop_end).
2683 */
2684 if (!clone_info && cur_offset < ino_size && cur_offset < drop_end) {
2685 ret = fill_holes(trans, BTRFS_I(inode), path,
2686 cur_offset, drop_end);
2687 if (ret) {
2688 /* Same comment as above. */
2689 btrfs_abort_transaction(trans, ret);
2690 goto out_trans;
2691 }
2692 }
2693 if (clone_info) {
2694 ret = btrfs_insert_clone_extent(trans, inode, path, clone_info,
2695 clone_info->data_len);
2696 if (ret) {
2697 btrfs_abort_transaction(trans, ret);
2698 goto out_trans;
2699 }
2700 }
2701
2702out_trans:
2703 if (!trans)
2704 goto out_free;
2705
2706 trans->block_rsv = &fs_info->trans_block_rsv;
2707 if (ret)
2708 btrfs_end_transaction(trans);
2709 else
2710 *trans_out = trans;
2711out_free:
2712 btrfs_free_block_rsv(fs_info, rsv);
2713out:
2714 return ret;
2715}
2716
2717static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2718{
2719 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2720 struct btrfs_root *root = BTRFS_I(inode)->root;
2721 struct extent_state *cached_state = NULL;
2722 struct btrfs_path *path;
2723 struct btrfs_trans_handle *trans = NULL;
2724 u64 lockstart;
2725 u64 lockend;
2726 u64 tail_start;
2727 u64 tail_len;
2728 u64 orig_start = offset;
2729 int ret = 0;
2730 bool same_block;
2731 u64 ino_size;
2732 bool truncated_block = false;
2733 bool updated_inode = false;
2734
2735 ret = btrfs_wait_ordered_range(inode, offset, len);
2736 if (ret)
2737 return ret;
2738
2739 inode_lock(inode);
2740 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2741 ret = find_first_non_hole(inode, &offset, &len);
2742 if (ret < 0)
2743 goto out_only_mutex;
2744 if (ret && !len) {
2745 /* Already in a large hole */
2746 ret = 0;
2747 goto out_only_mutex;
2748 }
2749
2750 lockstart = round_up(offset, btrfs_inode_sectorsize(inode));
2751 lockend = round_down(offset + len,
2752 btrfs_inode_sectorsize(inode)) - 1;
2753 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset))
2754 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1));
2755 /*
2756 * We needn't truncate any block which is beyond the end of the file
2757 * because we are sure there is no data there.
2758 */
2759 /*
2760 * Only do this if we are in the same block and we aren't doing the
2761 * entire block.
2762 */
2763 if (same_block && len < fs_info->sectorsize) {
2764 if (offset < ino_size) {
2765 truncated_block = true;
2766 ret = btrfs_truncate_block(inode, offset, len, 0);
2767 } else {
2768 ret = 0;
2769 }
2770 goto out_only_mutex;
2771 }
2772
2773 /* zero back part of the first block */
2774 if (offset < ino_size) {
2775 truncated_block = true;
2776 ret = btrfs_truncate_block(inode, offset, 0, 0);
2777 if (ret) {
2778 inode_unlock(inode);
2779 return ret;
2780 }
2781 }
2782
2783 /* Check the aligned pages after the first unaligned page,
2784 * if offset != orig_start, which means the first unaligned page
2785 * including several following pages are already in holes,
2786 * the extra check can be skipped */
2787 if (offset == orig_start) {
2788 /* after truncate page, check hole again */
2789 len = offset + len - lockstart;
2790 offset = lockstart;
2791 ret = find_first_non_hole(inode, &offset, &len);
2792 if (ret < 0)
2793 goto out_only_mutex;
2794 if (ret && !len) {
2795 ret = 0;
2796 goto out_only_mutex;
2797 }
2798 lockstart = offset;
2799 }
2800
2801 /* Check the tail unaligned part is in a hole */
2802 tail_start = lockend + 1;
2803 tail_len = offset + len - tail_start;
2804 if (tail_len) {
2805 ret = find_first_non_hole(inode, &tail_start, &tail_len);
2806 if (unlikely(ret < 0))
2807 goto out_only_mutex;
2808 if (!ret) {
2809 /* zero the front end of the last page */
2810 if (tail_start + tail_len < ino_size) {
2811 truncated_block = true;
2812 ret = btrfs_truncate_block(inode,
2813 tail_start + tail_len,
2814 0, 1);
2815 if (ret)
2816 goto out_only_mutex;
2817 }
2818 }
2819 }
2820
2821 if (lockend < lockstart) {
2822 ret = 0;
2823 goto out_only_mutex;
2824 }
2825
2826 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
2827 &cached_state);
2828 if (ret)
2829 goto out_only_mutex;
2830
2831 path = btrfs_alloc_path();
2832 if (!path) {
2833 ret = -ENOMEM;
2834 goto out;
2835 }
2836
2837 ret = btrfs_punch_hole_range(inode, path, lockstart, lockend, NULL,
2838 &trans);
2839 btrfs_free_path(path);
2840 if (ret)
2841 goto out;
2842
2843 ASSERT(trans != NULL);
2844 inode_inc_iversion(inode);
2845 inode->i_mtime = inode->i_ctime = current_time(inode);
2846 ret = btrfs_update_inode(trans, root, inode);
2847 updated_inode = true;
2848 btrfs_end_transaction(trans);
2849 btrfs_btree_balance_dirty(fs_info);
2850out:
2851 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2852 &cached_state);
2853out_only_mutex:
2854 if (!updated_inode && truncated_block && !ret) {
2855 /*
2856 * If we only end up zeroing part of a page, we still need to
2857 * update the inode item, so that all the time fields are
2858 * updated as well as the necessary btrfs inode in memory fields
2859 * for detecting, at fsync time, if the inode isn't yet in the
2860 * log tree or it's there but not up to date.
2861 */
2862 struct timespec64 now = current_time(inode);
2863
2864 inode_inc_iversion(inode);
2865 inode->i_mtime = now;
2866 inode->i_ctime = now;
2867 trans = btrfs_start_transaction(root, 1);
2868 if (IS_ERR(trans)) {
2869 ret = PTR_ERR(trans);
2870 } else {
2871 int ret2;
2872
2873 ret = btrfs_update_inode(trans, root, inode);
2874 ret2 = btrfs_end_transaction(trans);
2875 if (!ret)
2876 ret = ret2;
2877 }
2878 }
2879 inode_unlock(inode);
2880 return ret;
2881}
2882
2883/* Helper structure to record which range is already reserved */
2884struct falloc_range {
2885 struct list_head list;
2886 u64 start;
2887 u64 len;
2888};
2889
2890/*
2891 * Helper function to add falloc range
2892 *
2893 * Caller should have locked the larger range of extent containing
2894 * [start, len)
2895 */
2896static int add_falloc_range(struct list_head *head, u64 start, u64 len)
2897{
2898 struct falloc_range *prev = NULL;
2899 struct falloc_range *range = NULL;
2900
2901 if (list_empty(head))
2902 goto insert;
2903
2904 /*
2905 * As fallocate iterate by bytenr order, we only need to check
2906 * the last range.
2907 */
2908 prev = list_entry(head->prev, struct falloc_range, list);
2909 if (prev->start + prev->len == start) {
2910 prev->len += len;
2911 return 0;
2912 }
2913insert:
2914 range = kmalloc(sizeof(*range), GFP_KERNEL);
2915 if (!range)
2916 return -ENOMEM;
2917 range->start = start;
2918 range->len = len;
2919 list_add_tail(&range->list, head);
2920 return 0;
2921}
2922
2923static int btrfs_fallocate_update_isize(struct inode *inode,
2924 const u64 end,
2925 const int mode)
2926{
2927 struct btrfs_trans_handle *trans;
2928 struct btrfs_root *root = BTRFS_I(inode)->root;
2929 int ret;
2930 int ret2;
2931
2932 if (mode & FALLOC_FL_KEEP_SIZE || end <= i_size_read(inode))
2933 return 0;
2934
2935 trans = btrfs_start_transaction(root, 1);
2936 if (IS_ERR(trans))
2937 return PTR_ERR(trans);
2938
2939 inode->i_ctime = current_time(inode);
2940 i_size_write(inode, end);
2941 btrfs_ordered_update_i_size(inode, end, NULL);
2942 ret = btrfs_update_inode(trans, root, inode);
2943 ret2 = btrfs_end_transaction(trans);
2944
2945 return ret ? ret : ret2;
2946}
2947
2948enum {
2949 RANGE_BOUNDARY_WRITTEN_EXTENT,
2950 RANGE_BOUNDARY_PREALLOC_EXTENT,
2951 RANGE_BOUNDARY_HOLE,
2952};
2953
2954static int btrfs_zero_range_check_range_boundary(struct inode *inode,
2955 u64 offset)
2956{
2957 const u64 sectorsize = btrfs_inode_sectorsize(inode);
2958 struct extent_map *em;
2959 int ret;
2960
2961 offset = round_down(offset, sectorsize);
2962 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
2963 if (IS_ERR(em))
2964 return PTR_ERR(em);
2965
2966 if (em->block_start == EXTENT_MAP_HOLE)
2967 ret = RANGE_BOUNDARY_HOLE;
2968 else if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2969 ret = RANGE_BOUNDARY_PREALLOC_EXTENT;
2970 else
2971 ret = RANGE_BOUNDARY_WRITTEN_EXTENT;
2972
2973 free_extent_map(em);
2974 return ret;
2975}
2976
2977static int btrfs_zero_range(struct inode *inode,
2978 loff_t offset,
2979 loff_t len,
2980 const int mode)
2981{
2982 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2983 struct extent_map *em;
2984 struct extent_changeset *data_reserved = NULL;
2985 int ret;
2986 u64 alloc_hint = 0;
2987 const u64 sectorsize = btrfs_inode_sectorsize(inode);
2988 u64 alloc_start = round_down(offset, sectorsize);
2989 u64 alloc_end = round_up(offset + len, sectorsize);
2990 u64 bytes_to_reserve = 0;
2991 bool space_reserved = false;
2992
2993 inode_dio_wait(inode);
2994
2995 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2996 alloc_start, alloc_end - alloc_start, 0);
2997 if (IS_ERR(em)) {
2998 ret = PTR_ERR(em);
2999 goto out;
3000 }
3001
3002 /*
3003 * Avoid hole punching and extent allocation for some cases. More cases
3004 * could be considered, but these are unlikely common and we keep things
3005 * as simple as possible for now. Also, intentionally, if the target
3006 * range contains one or more prealloc extents together with regular
3007 * extents and holes, we drop all the existing extents and allocate a
3008 * new prealloc extent, so that we get a larger contiguous disk extent.
3009 */
3010 if (em->start <= alloc_start &&
3011 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3012 const u64 em_end = em->start + em->len;
3013
3014 if (em_end >= offset + len) {
3015 /*
3016 * The whole range is already a prealloc extent,
3017 * do nothing except updating the inode's i_size if
3018 * needed.
3019 */
3020 free_extent_map(em);
3021 ret = btrfs_fallocate_update_isize(inode, offset + len,
3022 mode);
3023 goto out;
3024 }
3025 /*
3026 * Part of the range is already a prealloc extent, so operate
3027 * only on the remaining part of the range.
3028 */
3029 alloc_start = em_end;
3030 ASSERT(IS_ALIGNED(alloc_start, sectorsize));
3031 len = offset + len - alloc_start;
3032 offset = alloc_start;
3033 alloc_hint = em->block_start + em->len;
3034 }
3035 free_extent_map(em);
3036
3037 if (BTRFS_BYTES_TO_BLKS(fs_info, offset) ==
3038 BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)) {
3039 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
3040 alloc_start, sectorsize, 0);
3041 if (IS_ERR(em)) {
3042 ret = PTR_ERR(em);
3043 goto out;
3044 }
3045
3046 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
3047 free_extent_map(em);
3048 ret = btrfs_fallocate_update_isize(inode, offset + len,
3049 mode);
3050 goto out;
3051 }
3052 if (len < sectorsize && em->block_start != EXTENT_MAP_HOLE) {
3053 free_extent_map(em);
3054 ret = btrfs_truncate_block(inode, offset, len, 0);
3055 if (!ret)
3056 ret = btrfs_fallocate_update_isize(inode,
3057 offset + len,
3058 mode);
3059 return ret;
3060 }
3061 free_extent_map(em);
3062 alloc_start = round_down(offset, sectorsize);
3063 alloc_end = alloc_start + sectorsize;
3064 goto reserve_space;
3065 }
3066
3067 alloc_start = round_up(offset, sectorsize);
3068 alloc_end = round_down(offset + len, sectorsize);
3069
3070 /*
3071 * For unaligned ranges, check the pages at the boundaries, they might
3072 * map to an extent, in which case we need to partially zero them, or
3073 * they might map to a hole, in which case we need our allocation range
3074 * to cover them.
3075 */
3076 if (!IS_ALIGNED(offset, sectorsize)) {
3077 ret = btrfs_zero_range_check_range_boundary(inode, offset);
3078 if (ret < 0)
3079 goto out;
3080 if (ret == RANGE_BOUNDARY_HOLE) {
3081 alloc_start = round_down(offset, sectorsize);
3082 ret = 0;
3083 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
3084 ret = btrfs_truncate_block(inode, offset, 0, 0);
3085 if (ret)
3086 goto out;
3087 } else {
3088 ret = 0;
3089 }
3090 }
3091
3092 if (!IS_ALIGNED(offset + len, sectorsize)) {
3093 ret = btrfs_zero_range_check_range_boundary(inode,
3094 offset + len);
3095 if (ret < 0)
3096 goto out;
3097 if (ret == RANGE_BOUNDARY_HOLE) {
3098 alloc_end = round_up(offset + len, sectorsize);
3099 ret = 0;
3100 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
3101 ret = btrfs_truncate_block(inode, offset + len, 0, 1);
3102 if (ret)
3103 goto out;
3104 } else {
3105 ret = 0;
3106 }
3107 }
3108
3109reserve_space:
3110 if (alloc_start < alloc_end) {
3111 struct extent_state *cached_state = NULL;
3112 const u64 lockstart = alloc_start;
3113 const u64 lockend = alloc_end - 1;
3114
3115 bytes_to_reserve = alloc_end - alloc_start;
3116 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3117 bytes_to_reserve);
3118 if (ret < 0)
3119 goto out;
3120 space_reserved = true;
3121 ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
3122 alloc_start, bytes_to_reserve);
3123 if (ret)
3124 goto out;
3125 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
3126 &cached_state);
3127 if (ret)
3128 goto out;
3129 ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
3130 alloc_end - alloc_start,
3131 i_blocksize(inode),
3132 offset + len, &alloc_hint);
3133 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
3134 lockend, &cached_state);
3135 /* btrfs_prealloc_file_range releases reserved space on error */
3136 if (ret) {
3137 space_reserved = false;
3138 goto out;
3139 }
3140 }
3141 ret = btrfs_fallocate_update_isize(inode, offset + len, mode);
3142 out:
3143 if (ret && space_reserved)
3144 btrfs_free_reserved_data_space(inode, data_reserved,
3145 alloc_start, bytes_to_reserve);
3146 extent_changeset_free(data_reserved);
3147
3148 return ret;
3149}
3150
3151static long btrfs_fallocate(struct file *file, int mode,
3152 loff_t offset, loff_t len)
3153{
3154 struct inode *inode = file_inode(file);
3155 struct extent_state *cached_state = NULL;
3156 struct extent_changeset *data_reserved = NULL;
3157 struct falloc_range *range;
3158 struct falloc_range *tmp;
3159 struct list_head reserve_list;
3160 u64 cur_offset;
3161 u64 last_byte;
3162 u64 alloc_start;
3163 u64 alloc_end;
3164 u64 alloc_hint = 0;
3165 u64 locked_end;
3166 u64 actual_end = 0;
3167 struct extent_map *em;
3168 int blocksize = btrfs_inode_sectorsize(inode);
3169 int ret;
3170
3171 alloc_start = round_down(offset, blocksize);
3172 alloc_end = round_up(offset + len, blocksize);
3173 cur_offset = alloc_start;
3174
3175 /* Make sure we aren't being give some crap mode */
3176 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
3177 FALLOC_FL_ZERO_RANGE))
3178 return -EOPNOTSUPP;
3179
3180 if (mode & FALLOC_FL_PUNCH_HOLE)
3181 return btrfs_punch_hole(inode, offset, len);
3182
3183 /*
3184 * Only trigger disk allocation, don't trigger qgroup reserve
3185 *
3186 * For qgroup space, it will be checked later.
3187 */
3188 if (!(mode & FALLOC_FL_ZERO_RANGE)) {
3189 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3190 alloc_end - alloc_start);
3191 if (ret < 0)
3192 return ret;
3193 }
3194
3195 inode_lock(inode);
3196
3197 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
3198 ret = inode_newsize_ok(inode, offset + len);
3199 if (ret)
3200 goto out;
3201 }
3202
3203 /*
3204 * TODO: Move these two operations after we have checked
3205 * accurate reserved space, or fallocate can still fail but
3206 * with page truncated or size expanded.
3207 *
3208 * But that's a minor problem and won't do much harm BTW.
3209 */
3210 if (alloc_start > inode->i_size) {
3211 ret = btrfs_cont_expand(inode, i_size_read(inode),
3212 alloc_start);
3213 if (ret)
3214 goto out;
3215 } else if (offset + len > inode->i_size) {
3216 /*
3217 * If we are fallocating from the end of the file onward we
3218 * need to zero out the end of the block if i_size lands in the
3219 * middle of a block.
3220 */
3221 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
3222 if (ret)
3223 goto out;
3224 }
3225
3226 /*
3227 * wait for ordered IO before we have any locks. We'll loop again
3228 * below with the locks held.
3229 */
3230 ret = btrfs_wait_ordered_range(inode, alloc_start,
3231 alloc_end - alloc_start);
3232 if (ret)
3233 goto out;
3234
3235 if (mode & FALLOC_FL_ZERO_RANGE) {
3236 ret = btrfs_zero_range(inode, offset, len, mode);
3237 inode_unlock(inode);
3238 return ret;
3239 }
3240
3241 locked_end = alloc_end - 1;
3242 while (1) {
3243 struct btrfs_ordered_extent *ordered;
3244
3245 /* the extent lock is ordered inside the running
3246 * transaction
3247 */
3248 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
3249 locked_end, &cached_state);
3250 ordered = btrfs_lookup_first_ordered_extent(inode, locked_end);
3251
3252 if (ordered &&
3253 ordered->file_offset + ordered->len > alloc_start &&
3254 ordered->file_offset < alloc_end) {
3255 btrfs_put_ordered_extent(ordered);
3256 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
3257 alloc_start, locked_end,
3258 &cached_state);
3259 /*
3260 * we can't wait on the range with the transaction
3261 * running or with the extent lock held
3262 */
3263 ret = btrfs_wait_ordered_range(inode, alloc_start,
3264 alloc_end - alloc_start);
3265 if (ret)
3266 goto out;
3267 } else {
3268 if (ordered)
3269 btrfs_put_ordered_extent(ordered);
3270 break;
3271 }
3272 }
3273
3274 /* First, check if we exceed the qgroup limit */
3275 INIT_LIST_HEAD(&reserve_list);
3276 while (cur_offset < alloc_end) {
3277 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
3278 alloc_end - cur_offset, 0);
3279 if (IS_ERR(em)) {
3280 ret = PTR_ERR(em);
3281 break;
3282 }
3283 last_byte = min(extent_map_end(em), alloc_end);
3284 actual_end = min_t(u64, extent_map_end(em), offset + len);
3285 last_byte = ALIGN(last_byte, blocksize);
3286 if (em->block_start == EXTENT_MAP_HOLE ||
3287 (cur_offset >= inode->i_size &&
3288 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
3289 ret = add_falloc_range(&reserve_list, cur_offset,
3290 last_byte - cur_offset);
3291 if (ret < 0) {
3292 free_extent_map(em);
3293 break;
3294 }
3295 ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
3296 cur_offset, last_byte - cur_offset);
3297 if (ret < 0) {
3298 cur_offset = last_byte;
3299 free_extent_map(em);
3300 break;
3301 }
3302 } else {
3303 /*
3304 * Do not need to reserve unwritten extent for this
3305 * range, free reserved data space first, otherwise
3306 * it'll result in false ENOSPC error.
3307 */
3308 btrfs_free_reserved_data_space(inode, data_reserved,
3309 cur_offset, last_byte - cur_offset);
3310 }
3311 free_extent_map(em);
3312 cur_offset = last_byte;
3313 }
3314
3315 /*
3316 * If ret is still 0, means we're OK to fallocate.
3317 * Or just cleanup the list and exit.
3318 */
3319 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
3320 if (!ret)
3321 ret = btrfs_prealloc_file_range(inode, mode,
3322 range->start,
3323 range->len, i_blocksize(inode),
3324 offset + len, &alloc_hint);
3325 else
3326 btrfs_free_reserved_data_space(inode,
3327 data_reserved, range->start,
3328 range->len);
3329 list_del(&range->list);
3330 kfree(range);
3331 }
3332 if (ret < 0)
3333 goto out_unlock;
3334
3335 /*
3336 * We didn't need to allocate any more space, but we still extended the
3337 * size of the file so we need to update i_size and the inode item.
3338 */
3339 ret = btrfs_fallocate_update_isize(inode, actual_end, mode);
3340out_unlock:
3341 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
3342 &cached_state);
3343out:
3344 inode_unlock(inode);
3345 /* Let go of our reservation. */
3346 if (ret != 0 && !(mode & FALLOC_FL_ZERO_RANGE))
3347 btrfs_free_reserved_data_space(inode, data_reserved,
3348 cur_offset, alloc_end - cur_offset);
3349 extent_changeset_free(data_reserved);
3350 return ret;
3351}
3352
3353static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
3354{
3355 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3356 struct extent_map *em = NULL;
3357 struct extent_state *cached_state = NULL;
3358 u64 lockstart;
3359 u64 lockend;
3360 u64 start;
3361 u64 len;
3362 int ret = 0;
3363
3364 if (inode->i_size == 0)
3365 return -ENXIO;
3366
3367 /*
3368 * *offset can be negative, in this case we start finding DATA/HOLE from
3369 * the very start of the file.
3370 */
3371 start = max_t(loff_t, 0, *offset);
3372
3373 lockstart = round_down(start, fs_info->sectorsize);
3374 lockend = round_up(i_size_read(inode),
3375 fs_info->sectorsize);
3376 if (lockend <= lockstart)
3377 lockend = lockstart + fs_info->sectorsize;
3378 lockend--;
3379 len = lockend - lockstart + 1;
3380
3381 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3382 &cached_state);
3383
3384 while (start < inode->i_size) {
3385 em = btrfs_get_extent_fiemap(BTRFS_I(inode), start, len);
3386 if (IS_ERR(em)) {
3387 ret = PTR_ERR(em);
3388 em = NULL;
3389 break;
3390 }
3391
3392 if (whence == SEEK_HOLE &&
3393 (em->block_start == EXTENT_MAP_HOLE ||
3394 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3395 break;
3396 else if (whence == SEEK_DATA &&
3397 (em->block_start != EXTENT_MAP_HOLE &&
3398 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3399 break;
3400
3401 start = em->start + em->len;
3402 free_extent_map(em);
3403 em = NULL;
3404 cond_resched();
3405 }
3406 free_extent_map(em);
3407 if (!ret) {
3408 if (whence == SEEK_DATA && start >= inode->i_size)
3409 ret = -ENXIO;
3410 else
3411 *offset = min_t(loff_t, start, inode->i_size);
3412 }
3413 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3414 &cached_state);
3415 return ret;
3416}
3417
3418static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
3419{
3420 struct inode *inode = file->f_mapping->host;
3421 int ret;
3422
3423 inode_lock(inode);
3424 switch (whence) {
3425 case SEEK_END:
3426 case SEEK_CUR:
3427 offset = generic_file_llseek(file, offset, whence);
3428 goto out;
3429 case SEEK_DATA:
3430 case SEEK_HOLE:
3431 if (offset >= i_size_read(inode)) {
3432 inode_unlock(inode);
3433 return -ENXIO;
3434 }
3435
3436 ret = find_desired_extent(inode, &offset, whence);
3437 if (ret) {
3438 inode_unlock(inode);
3439 return ret;
3440 }
3441 }
3442
3443 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
3444out:
3445 inode_unlock(inode);
3446 return offset;
3447}
3448
3449static int btrfs_file_open(struct inode *inode, struct file *filp)
3450{
3451 filp->f_mode |= FMODE_NOWAIT;
3452 return generic_file_open(inode, filp);
3453}
3454
3455const struct file_operations btrfs_file_operations = {
3456 .llseek = btrfs_file_llseek,
3457 .read_iter = generic_file_read_iter,
3458 .splice_read = generic_file_splice_read,
3459 .write_iter = btrfs_file_write_iter,
3460 .mmap = btrfs_file_mmap,
3461 .open = btrfs_file_open,
3462 .release = btrfs_release_file,
3463 .fsync = btrfs_sync_file,
3464 .fallocate = btrfs_fallocate,
3465 .unlocked_ioctl = btrfs_ioctl,
3466#ifdef CONFIG_COMPAT
3467 .compat_ioctl = btrfs_compat_ioctl,
3468#endif
3469 .remap_file_range = btrfs_remap_file_range,
3470};
3471
3472void __cold btrfs_auto_defrag_exit(void)
3473{
3474 kmem_cache_destroy(btrfs_inode_defrag_cachep);
3475}
3476
3477int __init btrfs_auto_defrag_init(void)
3478{
3479 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
3480 sizeof(struct inode_defrag), 0,
3481 SLAB_MEM_SPREAD,
3482 NULL);
3483 if (!btrfs_inode_defrag_cachep)
3484 return -ENOMEM;
3485
3486 return 0;
3487}
3488
3489int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
3490{
3491 int ret;
3492
3493 /*
3494 * So with compression we will find and lock a dirty page and clear the
3495 * first one as dirty, setup an async extent, and immediately return
3496 * with the entire range locked but with nobody actually marked with
3497 * writeback. So we can't just filemap_write_and_wait_range() and
3498 * expect it to work since it will just kick off a thread to do the
3499 * actual work. So we need to call filemap_fdatawrite_range _again_
3500 * since it will wait on the page lock, which won't be unlocked until
3501 * after the pages have been marked as writeback and so we're good to go
3502 * from there. We have to do this otherwise we'll miss the ordered
3503 * extents and that results in badness. Please Josef, do not think you
3504 * know better and pull this out at some point in the future, it is
3505 * right and you are wrong.
3506 */
3507 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3508 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
3509 &BTRFS_I(inode)->runtime_flags))
3510 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3511
3512 return ret;
3513}
1/*
2 * Copyright (C) 2007 Oracle. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
12 *
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
17 */
18
19#include <linux/fs.h>
20#include <linux/pagemap.h>
21#include <linux/highmem.h>
22#include <linux/time.h>
23#include <linux/init.h>
24#include <linux/string.h>
25#include <linux/backing-dev.h>
26#include <linux/mpage.h>
27#include <linux/aio.h>
28#include <linux/falloc.h>
29#include <linux/swap.h>
30#include <linux/writeback.h>
31#include <linux/statfs.h>
32#include <linux/compat.h>
33#include <linux/slab.h>
34#include <linux/btrfs.h>
35#include "ctree.h"
36#include "disk-io.h"
37#include "transaction.h"
38#include "btrfs_inode.h"
39#include "print-tree.h"
40#include "tree-log.h"
41#include "locking.h"
42#include "volumes.h"
43
44static struct kmem_cache *btrfs_inode_defrag_cachep;
45/*
46 * when auto defrag is enabled we
47 * queue up these defrag structs to remember which
48 * inodes need defragging passes
49 */
50struct inode_defrag {
51 struct rb_node rb_node;
52 /* objectid */
53 u64 ino;
54 /*
55 * transid where the defrag was added, we search for
56 * extents newer than this
57 */
58 u64 transid;
59
60 /* root objectid */
61 u64 root;
62
63 /* last offset we were able to defrag */
64 u64 last_offset;
65
66 /* if we've wrapped around back to zero once already */
67 int cycled;
68};
69
70static int __compare_inode_defrag(struct inode_defrag *defrag1,
71 struct inode_defrag *defrag2)
72{
73 if (defrag1->root > defrag2->root)
74 return 1;
75 else if (defrag1->root < defrag2->root)
76 return -1;
77 else if (defrag1->ino > defrag2->ino)
78 return 1;
79 else if (defrag1->ino < defrag2->ino)
80 return -1;
81 else
82 return 0;
83}
84
85/* pop a record for an inode into the defrag tree. The lock
86 * must be held already
87 *
88 * If you're inserting a record for an older transid than an
89 * existing record, the transid already in the tree is lowered
90 *
91 * If an existing record is found the defrag item you
92 * pass in is freed
93 */
94static int __btrfs_add_inode_defrag(struct inode *inode,
95 struct inode_defrag *defrag)
96{
97 struct btrfs_root *root = BTRFS_I(inode)->root;
98 struct inode_defrag *entry;
99 struct rb_node **p;
100 struct rb_node *parent = NULL;
101 int ret;
102
103 p = &root->fs_info->defrag_inodes.rb_node;
104 while (*p) {
105 parent = *p;
106 entry = rb_entry(parent, struct inode_defrag, rb_node);
107
108 ret = __compare_inode_defrag(defrag, entry);
109 if (ret < 0)
110 p = &parent->rb_left;
111 else if (ret > 0)
112 p = &parent->rb_right;
113 else {
114 /* if we're reinserting an entry for
115 * an old defrag run, make sure to
116 * lower the transid of our existing record
117 */
118 if (defrag->transid < entry->transid)
119 entry->transid = defrag->transid;
120 if (defrag->last_offset > entry->last_offset)
121 entry->last_offset = defrag->last_offset;
122 return -EEXIST;
123 }
124 }
125 set_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
126 rb_link_node(&defrag->rb_node, parent, p);
127 rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes);
128 return 0;
129}
130
131static inline int __need_auto_defrag(struct btrfs_root *root)
132{
133 if (!btrfs_test_opt(root, AUTO_DEFRAG))
134 return 0;
135
136 if (btrfs_fs_closing(root->fs_info))
137 return 0;
138
139 return 1;
140}
141
142/*
143 * insert a defrag record for this inode if auto defrag is
144 * enabled
145 */
146int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
147 struct inode *inode)
148{
149 struct btrfs_root *root = BTRFS_I(inode)->root;
150 struct inode_defrag *defrag;
151 u64 transid;
152 int ret;
153
154 if (!__need_auto_defrag(root))
155 return 0;
156
157 if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags))
158 return 0;
159
160 if (trans)
161 transid = trans->transid;
162 else
163 transid = BTRFS_I(inode)->root->last_trans;
164
165 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
166 if (!defrag)
167 return -ENOMEM;
168
169 defrag->ino = btrfs_ino(inode);
170 defrag->transid = transid;
171 defrag->root = root->root_key.objectid;
172
173 spin_lock(&root->fs_info->defrag_inodes_lock);
174 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) {
175 /*
176 * If we set IN_DEFRAG flag and evict the inode from memory,
177 * and then re-read this inode, this new inode doesn't have
178 * IN_DEFRAG flag. At the case, we may find the existed defrag.
179 */
180 ret = __btrfs_add_inode_defrag(inode, defrag);
181 if (ret)
182 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
183 } else {
184 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
185 }
186 spin_unlock(&root->fs_info->defrag_inodes_lock);
187 return 0;
188}
189
190/*
191 * Requeue the defrag object. If there is a defrag object that points to
192 * the same inode in the tree, we will merge them together (by
193 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
194 */
195static void btrfs_requeue_inode_defrag(struct inode *inode,
196 struct inode_defrag *defrag)
197{
198 struct btrfs_root *root = BTRFS_I(inode)->root;
199 int ret;
200
201 if (!__need_auto_defrag(root))
202 goto out;
203
204 /*
205 * Here we don't check the IN_DEFRAG flag, because we need merge
206 * them together.
207 */
208 spin_lock(&root->fs_info->defrag_inodes_lock);
209 ret = __btrfs_add_inode_defrag(inode, defrag);
210 spin_unlock(&root->fs_info->defrag_inodes_lock);
211 if (ret)
212 goto out;
213 return;
214out:
215 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
216}
217
218/*
219 * pick the defragable inode that we want, if it doesn't exist, we will get
220 * the next one.
221 */
222static struct inode_defrag *
223btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
224{
225 struct inode_defrag *entry = NULL;
226 struct inode_defrag tmp;
227 struct rb_node *p;
228 struct rb_node *parent = NULL;
229 int ret;
230
231 tmp.ino = ino;
232 tmp.root = root;
233
234 spin_lock(&fs_info->defrag_inodes_lock);
235 p = fs_info->defrag_inodes.rb_node;
236 while (p) {
237 parent = p;
238 entry = rb_entry(parent, struct inode_defrag, rb_node);
239
240 ret = __compare_inode_defrag(&tmp, entry);
241 if (ret < 0)
242 p = parent->rb_left;
243 else if (ret > 0)
244 p = parent->rb_right;
245 else
246 goto out;
247 }
248
249 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
250 parent = rb_next(parent);
251 if (parent)
252 entry = rb_entry(parent, struct inode_defrag, rb_node);
253 else
254 entry = NULL;
255 }
256out:
257 if (entry)
258 rb_erase(parent, &fs_info->defrag_inodes);
259 spin_unlock(&fs_info->defrag_inodes_lock);
260 return entry;
261}
262
263void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
264{
265 struct inode_defrag *defrag;
266 struct rb_node *node;
267
268 spin_lock(&fs_info->defrag_inodes_lock);
269 node = rb_first(&fs_info->defrag_inodes);
270 while (node) {
271 rb_erase(node, &fs_info->defrag_inodes);
272 defrag = rb_entry(node, struct inode_defrag, rb_node);
273 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
274
275 if (need_resched()) {
276 spin_unlock(&fs_info->defrag_inodes_lock);
277 cond_resched();
278 spin_lock(&fs_info->defrag_inodes_lock);
279 }
280
281 node = rb_first(&fs_info->defrag_inodes);
282 }
283 spin_unlock(&fs_info->defrag_inodes_lock);
284}
285
286#define BTRFS_DEFRAG_BATCH 1024
287
288static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
289 struct inode_defrag *defrag)
290{
291 struct btrfs_root *inode_root;
292 struct inode *inode;
293 struct btrfs_key key;
294 struct btrfs_ioctl_defrag_range_args range;
295 int num_defrag;
296 int index;
297 int ret;
298
299 /* get the inode */
300 key.objectid = defrag->root;
301 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
302 key.offset = (u64)-1;
303
304 index = srcu_read_lock(&fs_info->subvol_srcu);
305
306 inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
307 if (IS_ERR(inode_root)) {
308 ret = PTR_ERR(inode_root);
309 goto cleanup;
310 }
311
312 key.objectid = defrag->ino;
313 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
314 key.offset = 0;
315 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
316 if (IS_ERR(inode)) {
317 ret = PTR_ERR(inode);
318 goto cleanup;
319 }
320 srcu_read_unlock(&fs_info->subvol_srcu, index);
321
322 /* do a chunk of defrag */
323 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
324 memset(&range, 0, sizeof(range));
325 range.len = (u64)-1;
326 range.start = defrag->last_offset;
327
328 sb_start_write(fs_info->sb);
329 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
330 BTRFS_DEFRAG_BATCH);
331 sb_end_write(fs_info->sb);
332 /*
333 * if we filled the whole defrag batch, there
334 * must be more work to do. Queue this defrag
335 * again
336 */
337 if (num_defrag == BTRFS_DEFRAG_BATCH) {
338 defrag->last_offset = range.start;
339 btrfs_requeue_inode_defrag(inode, defrag);
340 } else if (defrag->last_offset && !defrag->cycled) {
341 /*
342 * we didn't fill our defrag batch, but
343 * we didn't start at zero. Make sure we loop
344 * around to the start of the file.
345 */
346 defrag->last_offset = 0;
347 defrag->cycled = 1;
348 btrfs_requeue_inode_defrag(inode, defrag);
349 } else {
350 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
351 }
352
353 iput(inode);
354 return 0;
355cleanup:
356 srcu_read_unlock(&fs_info->subvol_srcu, index);
357 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
358 return ret;
359}
360
361/*
362 * run through the list of inodes in the FS that need
363 * defragging
364 */
365int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
366{
367 struct inode_defrag *defrag;
368 u64 first_ino = 0;
369 u64 root_objectid = 0;
370
371 atomic_inc(&fs_info->defrag_running);
372 while (1) {
373 /* Pause the auto defragger. */
374 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
375 &fs_info->fs_state))
376 break;
377
378 if (!__need_auto_defrag(fs_info->tree_root))
379 break;
380
381 /* find an inode to defrag */
382 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
383 first_ino);
384 if (!defrag) {
385 if (root_objectid || first_ino) {
386 root_objectid = 0;
387 first_ino = 0;
388 continue;
389 } else {
390 break;
391 }
392 }
393
394 first_ino = defrag->ino + 1;
395 root_objectid = defrag->root;
396
397 __btrfs_run_defrag_inode(fs_info, defrag);
398 }
399 atomic_dec(&fs_info->defrag_running);
400
401 /*
402 * during unmount, we use the transaction_wait queue to
403 * wait for the defragger to stop
404 */
405 wake_up(&fs_info->transaction_wait);
406 return 0;
407}
408
409/* simple helper to fault in pages and copy. This should go away
410 * and be replaced with calls into generic code.
411 */
412static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
413 size_t write_bytes,
414 struct page **prepared_pages,
415 struct iov_iter *i)
416{
417 size_t copied = 0;
418 size_t total_copied = 0;
419 int pg = 0;
420 int offset = pos & (PAGE_CACHE_SIZE - 1);
421
422 while (write_bytes > 0) {
423 size_t count = min_t(size_t,
424 PAGE_CACHE_SIZE - offset, write_bytes);
425 struct page *page = prepared_pages[pg];
426 /*
427 * Copy data from userspace to the current page
428 */
429 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
430
431 /* Flush processor's dcache for this page */
432 flush_dcache_page(page);
433
434 /*
435 * if we get a partial write, we can end up with
436 * partially up to date pages. These add
437 * a lot of complexity, so make sure they don't
438 * happen by forcing this copy to be retried.
439 *
440 * The rest of the btrfs_file_write code will fall
441 * back to page at a time copies after we return 0.
442 */
443 if (!PageUptodate(page) && copied < count)
444 copied = 0;
445
446 iov_iter_advance(i, copied);
447 write_bytes -= copied;
448 total_copied += copied;
449
450 /* Return to btrfs_file_aio_write to fault page */
451 if (unlikely(copied == 0))
452 break;
453
454 if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
455 offset += copied;
456 } else {
457 pg++;
458 offset = 0;
459 }
460 }
461 return total_copied;
462}
463
464/*
465 * unlocks pages after btrfs_file_write is done with them
466 */
467static void btrfs_drop_pages(struct page **pages, size_t num_pages)
468{
469 size_t i;
470 for (i = 0; i < num_pages; i++) {
471 /* page checked is some magic around finding pages that
472 * have been modified without going through btrfs_set_page_dirty
473 * clear it here
474 */
475 ClearPageChecked(pages[i]);
476 unlock_page(pages[i]);
477 mark_page_accessed(pages[i]);
478 page_cache_release(pages[i]);
479 }
480}
481
482/*
483 * after copy_from_user, pages need to be dirtied and we need to make
484 * sure holes are created between the current EOF and the start of
485 * any next extents (if required).
486 *
487 * this also makes the decision about creating an inline extent vs
488 * doing real data extents, marking pages dirty and delalloc as required.
489 */
490int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode,
491 struct page **pages, size_t num_pages,
492 loff_t pos, size_t write_bytes,
493 struct extent_state **cached)
494{
495 int err = 0;
496 int i;
497 u64 num_bytes;
498 u64 start_pos;
499 u64 end_of_last_block;
500 u64 end_pos = pos + write_bytes;
501 loff_t isize = i_size_read(inode);
502
503 start_pos = pos & ~((u64)root->sectorsize - 1);
504 num_bytes = ALIGN(write_bytes + pos - start_pos, root->sectorsize);
505
506 end_of_last_block = start_pos + num_bytes - 1;
507 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
508 cached);
509 if (err)
510 return err;
511
512 for (i = 0; i < num_pages; i++) {
513 struct page *p = pages[i];
514 SetPageUptodate(p);
515 ClearPageChecked(p);
516 set_page_dirty(p);
517 }
518
519 /*
520 * we've only changed i_size in ram, and we haven't updated
521 * the disk i_size. There is no need to log the inode
522 * at this time.
523 */
524 if (end_pos > isize)
525 i_size_write(inode, end_pos);
526 return 0;
527}
528
529/*
530 * this drops all the extents in the cache that intersect the range
531 * [start, end]. Existing extents are split as required.
532 */
533void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
534 int skip_pinned)
535{
536 struct extent_map *em;
537 struct extent_map *split = NULL;
538 struct extent_map *split2 = NULL;
539 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
540 u64 len = end - start + 1;
541 u64 gen;
542 int ret;
543 int testend = 1;
544 unsigned long flags;
545 int compressed = 0;
546 bool modified;
547
548 WARN_ON(end < start);
549 if (end == (u64)-1) {
550 len = (u64)-1;
551 testend = 0;
552 }
553 while (1) {
554 int no_splits = 0;
555
556 modified = false;
557 if (!split)
558 split = alloc_extent_map();
559 if (!split2)
560 split2 = alloc_extent_map();
561 if (!split || !split2)
562 no_splits = 1;
563
564 write_lock(&em_tree->lock);
565 em = lookup_extent_mapping(em_tree, start, len);
566 if (!em) {
567 write_unlock(&em_tree->lock);
568 break;
569 }
570 flags = em->flags;
571 gen = em->generation;
572 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
573 if (testend && em->start + em->len >= start + len) {
574 free_extent_map(em);
575 write_unlock(&em_tree->lock);
576 break;
577 }
578 start = em->start + em->len;
579 if (testend)
580 len = start + len - (em->start + em->len);
581 free_extent_map(em);
582 write_unlock(&em_tree->lock);
583 continue;
584 }
585 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
586 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
587 clear_bit(EXTENT_FLAG_LOGGING, &flags);
588 modified = !list_empty(&em->list);
589 if (no_splits)
590 goto next;
591
592 if (em->start < start) {
593 split->start = em->start;
594 split->len = start - em->start;
595
596 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
597 split->orig_start = em->orig_start;
598 split->block_start = em->block_start;
599
600 if (compressed)
601 split->block_len = em->block_len;
602 else
603 split->block_len = split->len;
604 split->orig_block_len = max(split->block_len,
605 em->orig_block_len);
606 split->ram_bytes = em->ram_bytes;
607 } else {
608 split->orig_start = split->start;
609 split->block_len = 0;
610 split->block_start = em->block_start;
611 split->orig_block_len = 0;
612 split->ram_bytes = split->len;
613 }
614
615 split->generation = gen;
616 split->bdev = em->bdev;
617 split->flags = flags;
618 split->compress_type = em->compress_type;
619 replace_extent_mapping(em_tree, em, split, modified);
620 free_extent_map(split);
621 split = split2;
622 split2 = NULL;
623 }
624 if (testend && em->start + em->len > start + len) {
625 u64 diff = start + len - em->start;
626
627 split->start = start + len;
628 split->len = em->start + em->len - (start + len);
629 split->bdev = em->bdev;
630 split->flags = flags;
631 split->compress_type = em->compress_type;
632 split->generation = gen;
633
634 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
635 split->orig_block_len = max(em->block_len,
636 em->orig_block_len);
637
638 split->ram_bytes = em->ram_bytes;
639 if (compressed) {
640 split->block_len = em->block_len;
641 split->block_start = em->block_start;
642 split->orig_start = em->orig_start;
643 } else {
644 split->block_len = split->len;
645 split->block_start = em->block_start
646 + diff;
647 split->orig_start = em->orig_start;
648 }
649 } else {
650 split->ram_bytes = split->len;
651 split->orig_start = split->start;
652 split->block_len = 0;
653 split->block_start = em->block_start;
654 split->orig_block_len = 0;
655 }
656
657 if (extent_map_in_tree(em)) {
658 replace_extent_mapping(em_tree, em, split,
659 modified);
660 } else {
661 ret = add_extent_mapping(em_tree, split,
662 modified);
663 ASSERT(ret == 0); /* Logic error */
664 }
665 free_extent_map(split);
666 split = NULL;
667 }
668next:
669 if (extent_map_in_tree(em))
670 remove_extent_mapping(em_tree, em);
671 write_unlock(&em_tree->lock);
672
673 /* once for us */
674 free_extent_map(em);
675 /* once for the tree*/
676 free_extent_map(em);
677 }
678 if (split)
679 free_extent_map(split);
680 if (split2)
681 free_extent_map(split2);
682}
683
684/*
685 * this is very complex, but the basic idea is to drop all extents
686 * in the range start - end. hint_block is filled in with a block number
687 * that would be a good hint to the block allocator for this file.
688 *
689 * If an extent intersects the range but is not entirely inside the range
690 * it is either truncated or split. Anything entirely inside the range
691 * is deleted from the tree.
692 */
693int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
694 struct btrfs_root *root, struct inode *inode,
695 struct btrfs_path *path, u64 start, u64 end,
696 u64 *drop_end, int drop_cache,
697 int replace_extent,
698 u32 extent_item_size,
699 int *key_inserted)
700{
701 struct extent_buffer *leaf;
702 struct btrfs_file_extent_item *fi;
703 struct btrfs_key key;
704 struct btrfs_key new_key;
705 u64 ino = btrfs_ino(inode);
706 u64 search_start = start;
707 u64 disk_bytenr = 0;
708 u64 num_bytes = 0;
709 u64 extent_offset = 0;
710 u64 extent_end = 0;
711 int del_nr = 0;
712 int del_slot = 0;
713 int extent_type;
714 int recow;
715 int ret;
716 int modify_tree = -1;
717 int update_refs = (root->ref_cows || root == root->fs_info->tree_root);
718 int found = 0;
719 int leafs_visited = 0;
720
721 if (drop_cache)
722 btrfs_drop_extent_cache(inode, start, end - 1, 0);
723
724 if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent)
725 modify_tree = 0;
726
727 while (1) {
728 recow = 0;
729 ret = btrfs_lookup_file_extent(trans, root, path, ino,
730 search_start, modify_tree);
731 if (ret < 0)
732 break;
733 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
734 leaf = path->nodes[0];
735 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
736 if (key.objectid == ino &&
737 key.type == BTRFS_EXTENT_DATA_KEY)
738 path->slots[0]--;
739 }
740 ret = 0;
741 leafs_visited++;
742next_slot:
743 leaf = path->nodes[0];
744 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
745 BUG_ON(del_nr > 0);
746 ret = btrfs_next_leaf(root, path);
747 if (ret < 0)
748 break;
749 if (ret > 0) {
750 ret = 0;
751 break;
752 }
753 leafs_visited++;
754 leaf = path->nodes[0];
755 recow = 1;
756 }
757
758 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
759 if (key.objectid > ino ||
760 key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
761 break;
762
763 fi = btrfs_item_ptr(leaf, path->slots[0],
764 struct btrfs_file_extent_item);
765 extent_type = btrfs_file_extent_type(leaf, fi);
766
767 if (extent_type == BTRFS_FILE_EXTENT_REG ||
768 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
769 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
770 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
771 extent_offset = btrfs_file_extent_offset(leaf, fi);
772 extent_end = key.offset +
773 btrfs_file_extent_num_bytes(leaf, fi);
774 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
775 extent_end = key.offset +
776 btrfs_file_extent_inline_len(leaf,
777 path->slots[0], fi);
778 } else {
779 WARN_ON(1);
780 extent_end = search_start;
781 }
782
783 if (extent_end <= search_start) {
784 path->slots[0]++;
785 goto next_slot;
786 }
787
788 found = 1;
789 search_start = max(key.offset, start);
790 if (recow || !modify_tree) {
791 modify_tree = -1;
792 btrfs_release_path(path);
793 continue;
794 }
795
796 /*
797 * | - range to drop - |
798 * | -------- extent -------- |
799 */
800 if (start > key.offset && end < extent_end) {
801 BUG_ON(del_nr > 0);
802 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
803 ret = -EOPNOTSUPP;
804 break;
805 }
806
807 memcpy(&new_key, &key, sizeof(new_key));
808 new_key.offset = start;
809 ret = btrfs_duplicate_item(trans, root, path,
810 &new_key);
811 if (ret == -EAGAIN) {
812 btrfs_release_path(path);
813 continue;
814 }
815 if (ret < 0)
816 break;
817
818 leaf = path->nodes[0];
819 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
820 struct btrfs_file_extent_item);
821 btrfs_set_file_extent_num_bytes(leaf, fi,
822 start - key.offset);
823
824 fi = btrfs_item_ptr(leaf, path->slots[0],
825 struct btrfs_file_extent_item);
826
827 extent_offset += start - key.offset;
828 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
829 btrfs_set_file_extent_num_bytes(leaf, fi,
830 extent_end - start);
831 btrfs_mark_buffer_dirty(leaf);
832
833 if (update_refs && disk_bytenr > 0) {
834 ret = btrfs_inc_extent_ref(trans, root,
835 disk_bytenr, num_bytes, 0,
836 root->root_key.objectid,
837 new_key.objectid,
838 start - extent_offset, 0);
839 BUG_ON(ret); /* -ENOMEM */
840 }
841 key.offset = start;
842 }
843 /*
844 * | ---- range to drop ----- |
845 * | -------- extent -------- |
846 */
847 if (start <= key.offset && end < extent_end) {
848 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
849 ret = -EOPNOTSUPP;
850 break;
851 }
852
853 memcpy(&new_key, &key, sizeof(new_key));
854 new_key.offset = end;
855 btrfs_set_item_key_safe(root, path, &new_key);
856
857 extent_offset += end - key.offset;
858 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
859 btrfs_set_file_extent_num_bytes(leaf, fi,
860 extent_end - end);
861 btrfs_mark_buffer_dirty(leaf);
862 if (update_refs && disk_bytenr > 0)
863 inode_sub_bytes(inode, end - key.offset);
864 break;
865 }
866
867 search_start = extent_end;
868 /*
869 * | ---- range to drop ----- |
870 * | -------- extent -------- |
871 */
872 if (start > key.offset && end >= extent_end) {
873 BUG_ON(del_nr > 0);
874 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
875 ret = -EOPNOTSUPP;
876 break;
877 }
878
879 btrfs_set_file_extent_num_bytes(leaf, fi,
880 start - key.offset);
881 btrfs_mark_buffer_dirty(leaf);
882 if (update_refs && disk_bytenr > 0)
883 inode_sub_bytes(inode, extent_end - start);
884 if (end == extent_end)
885 break;
886
887 path->slots[0]++;
888 goto next_slot;
889 }
890
891 /*
892 * | ---- range to drop ----- |
893 * | ------ extent ------ |
894 */
895 if (start <= key.offset && end >= extent_end) {
896 if (del_nr == 0) {
897 del_slot = path->slots[0];
898 del_nr = 1;
899 } else {
900 BUG_ON(del_slot + del_nr != path->slots[0]);
901 del_nr++;
902 }
903
904 if (update_refs &&
905 extent_type == BTRFS_FILE_EXTENT_INLINE) {
906 inode_sub_bytes(inode,
907 extent_end - key.offset);
908 extent_end = ALIGN(extent_end,
909 root->sectorsize);
910 } else if (update_refs && disk_bytenr > 0) {
911 ret = btrfs_free_extent(trans, root,
912 disk_bytenr, num_bytes, 0,
913 root->root_key.objectid,
914 key.objectid, key.offset -
915 extent_offset, 0);
916 BUG_ON(ret); /* -ENOMEM */
917 inode_sub_bytes(inode,
918 extent_end - key.offset);
919 }
920
921 if (end == extent_end)
922 break;
923
924 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
925 path->slots[0]++;
926 goto next_slot;
927 }
928
929 ret = btrfs_del_items(trans, root, path, del_slot,
930 del_nr);
931 if (ret) {
932 btrfs_abort_transaction(trans, root, ret);
933 break;
934 }
935
936 del_nr = 0;
937 del_slot = 0;
938
939 btrfs_release_path(path);
940 continue;
941 }
942
943 BUG_ON(1);
944 }
945
946 if (!ret && del_nr > 0) {
947 /*
948 * Set path->slots[0] to first slot, so that after the delete
949 * if items are move off from our leaf to its immediate left or
950 * right neighbor leafs, we end up with a correct and adjusted
951 * path->slots[0] for our insertion (if replace_extent != 0).
952 */
953 path->slots[0] = del_slot;
954 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
955 if (ret)
956 btrfs_abort_transaction(trans, root, ret);
957 }
958
959 leaf = path->nodes[0];
960 /*
961 * If btrfs_del_items() was called, it might have deleted a leaf, in
962 * which case it unlocked our path, so check path->locks[0] matches a
963 * write lock.
964 */
965 if (!ret && replace_extent && leafs_visited == 1 &&
966 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
967 path->locks[0] == BTRFS_WRITE_LOCK) &&
968 btrfs_leaf_free_space(root, leaf) >=
969 sizeof(struct btrfs_item) + extent_item_size) {
970
971 key.objectid = ino;
972 key.type = BTRFS_EXTENT_DATA_KEY;
973 key.offset = start;
974 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
975 struct btrfs_key slot_key;
976
977 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
978 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
979 path->slots[0]++;
980 }
981 setup_items_for_insert(root, path, &key,
982 &extent_item_size,
983 extent_item_size,
984 sizeof(struct btrfs_item) +
985 extent_item_size, 1);
986 *key_inserted = 1;
987 }
988
989 if (!replace_extent || !(*key_inserted))
990 btrfs_release_path(path);
991 if (drop_end)
992 *drop_end = found ? min(end, extent_end) : end;
993 return ret;
994}
995
996int btrfs_drop_extents(struct btrfs_trans_handle *trans,
997 struct btrfs_root *root, struct inode *inode, u64 start,
998 u64 end, int drop_cache)
999{
1000 struct btrfs_path *path;
1001 int ret;
1002
1003 path = btrfs_alloc_path();
1004 if (!path)
1005 return -ENOMEM;
1006 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
1007 drop_cache, 0, 0, NULL);
1008 btrfs_free_path(path);
1009 return ret;
1010}
1011
1012static int extent_mergeable(struct extent_buffer *leaf, int slot,
1013 u64 objectid, u64 bytenr, u64 orig_offset,
1014 u64 *start, u64 *end)
1015{
1016 struct btrfs_file_extent_item *fi;
1017 struct btrfs_key key;
1018 u64 extent_end;
1019
1020 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1021 return 0;
1022
1023 btrfs_item_key_to_cpu(leaf, &key, slot);
1024 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1025 return 0;
1026
1027 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1028 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1029 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1030 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1031 btrfs_file_extent_compression(leaf, fi) ||
1032 btrfs_file_extent_encryption(leaf, fi) ||
1033 btrfs_file_extent_other_encoding(leaf, fi))
1034 return 0;
1035
1036 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1037 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1038 return 0;
1039
1040 *start = key.offset;
1041 *end = extent_end;
1042 return 1;
1043}
1044
1045/*
1046 * Mark extent in the range start - end as written.
1047 *
1048 * This changes extent type from 'pre-allocated' to 'regular'. If only
1049 * part of extent is marked as written, the extent will be split into
1050 * two or three.
1051 */
1052int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1053 struct inode *inode, u64 start, u64 end)
1054{
1055 struct btrfs_root *root = BTRFS_I(inode)->root;
1056 struct extent_buffer *leaf;
1057 struct btrfs_path *path;
1058 struct btrfs_file_extent_item *fi;
1059 struct btrfs_key key;
1060 struct btrfs_key new_key;
1061 u64 bytenr;
1062 u64 num_bytes;
1063 u64 extent_end;
1064 u64 orig_offset;
1065 u64 other_start;
1066 u64 other_end;
1067 u64 split;
1068 int del_nr = 0;
1069 int del_slot = 0;
1070 int recow;
1071 int ret;
1072 u64 ino = btrfs_ino(inode);
1073
1074 path = btrfs_alloc_path();
1075 if (!path)
1076 return -ENOMEM;
1077again:
1078 recow = 0;
1079 split = start;
1080 key.objectid = ino;
1081 key.type = BTRFS_EXTENT_DATA_KEY;
1082 key.offset = split;
1083
1084 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1085 if (ret < 0)
1086 goto out;
1087 if (ret > 0 && path->slots[0] > 0)
1088 path->slots[0]--;
1089
1090 leaf = path->nodes[0];
1091 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1092 BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY);
1093 fi = btrfs_item_ptr(leaf, path->slots[0],
1094 struct btrfs_file_extent_item);
1095 BUG_ON(btrfs_file_extent_type(leaf, fi) !=
1096 BTRFS_FILE_EXTENT_PREALLOC);
1097 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1098 BUG_ON(key.offset > start || extent_end < end);
1099
1100 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1101 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1102 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1103 memcpy(&new_key, &key, sizeof(new_key));
1104
1105 if (start == key.offset && end < extent_end) {
1106 other_start = 0;
1107 other_end = start;
1108 if (extent_mergeable(leaf, path->slots[0] - 1,
1109 ino, bytenr, orig_offset,
1110 &other_start, &other_end)) {
1111 new_key.offset = end;
1112 btrfs_set_item_key_safe(root, path, &new_key);
1113 fi = btrfs_item_ptr(leaf, path->slots[0],
1114 struct btrfs_file_extent_item);
1115 btrfs_set_file_extent_generation(leaf, fi,
1116 trans->transid);
1117 btrfs_set_file_extent_num_bytes(leaf, fi,
1118 extent_end - end);
1119 btrfs_set_file_extent_offset(leaf, fi,
1120 end - orig_offset);
1121 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1122 struct btrfs_file_extent_item);
1123 btrfs_set_file_extent_generation(leaf, fi,
1124 trans->transid);
1125 btrfs_set_file_extent_num_bytes(leaf, fi,
1126 end - other_start);
1127 btrfs_mark_buffer_dirty(leaf);
1128 goto out;
1129 }
1130 }
1131
1132 if (start > key.offset && end == extent_end) {
1133 other_start = end;
1134 other_end = 0;
1135 if (extent_mergeable(leaf, path->slots[0] + 1,
1136 ino, bytenr, orig_offset,
1137 &other_start, &other_end)) {
1138 fi = btrfs_item_ptr(leaf, path->slots[0],
1139 struct btrfs_file_extent_item);
1140 btrfs_set_file_extent_num_bytes(leaf, fi,
1141 start - key.offset);
1142 btrfs_set_file_extent_generation(leaf, fi,
1143 trans->transid);
1144 path->slots[0]++;
1145 new_key.offset = start;
1146 btrfs_set_item_key_safe(root, path, &new_key);
1147
1148 fi = btrfs_item_ptr(leaf, path->slots[0],
1149 struct btrfs_file_extent_item);
1150 btrfs_set_file_extent_generation(leaf, fi,
1151 trans->transid);
1152 btrfs_set_file_extent_num_bytes(leaf, fi,
1153 other_end - start);
1154 btrfs_set_file_extent_offset(leaf, fi,
1155 start - orig_offset);
1156 btrfs_mark_buffer_dirty(leaf);
1157 goto out;
1158 }
1159 }
1160
1161 while (start > key.offset || end < extent_end) {
1162 if (key.offset == start)
1163 split = end;
1164
1165 new_key.offset = split;
1166 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1167 if (ret == -EAGAIN) {
1168 btrfs_release_path(path);
1169 goto again;
1170 }
1171 if (ret < 0) {
1172 btrfs_abort_transaction(trans, root, ret);
1173 goto out;
1174 }
1175
1176 leaf = path->nodes[0];
1177 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1178 struct btrfs_file_extent_item);
1179 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1180 btrfs_set_file_extent_num_bytes(leaf, fi,
1181 split - key.offset);
1182
1183 fi = btrfs_item_ptr(leaf, path->slots[0],
1184 struct btrfs_file_extent_item);
1185
1186 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1187 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1188 btrfs_set_file_extent_num_bytes(leaf, fi,
1189 extent_end - split);
1190 btrfs_mark_buffer_dirty(leaf);
1191
1192 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
1193 root->root_key.objectid,
1194 ino, orig_offset, 0);
1195 BUG_ON(ret); /* -ENOMEM */
1196
1197 if (split == start) {
1198 key.offset = start;
1199 } else {
1200 BUG_ON(start != key.offset);
1201 path->slots[0]--;
1202 extent_end = end;
1203 }
1204 recow = 1;
1205 }
1206
1207 other_start = end;
1208 other_end = 0;
1209 if (extent_mergeable(leaf, path->slots[0] + 1,
1210 ino, bytenr, orig_offset,
1211 &other_start, &other_end)) {
1212 if (recow) {
1213 btrfs_release_path(path);
1214 goto again;
1215 }
1216 extent_end = other_end;
1217 del_slot = path->slots[0] + 1;
1218 del_nr++;
1219 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1220 0, root->root_key.objectid,
1221 ino, orig_offset, 0);
1222 BUG_ON(ret); /* -ENOMEM */
1223 }
1224 other_start = 0;
1225 other_end = start;
1226 if (extent_mergeable(leaf, path->slots[0] - 1,
1227 ino, bytenr, orig_offset,
1228 &other_start, &other_end)) {
1229 if (recow) {
1230 btrfs_release_path(path);
1231 goto again;
1232 }
1233 key.offset = other_start;
1234 del_slot = path->slots[0];
1235 del_nr++;
1236 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1237 0, root->root_key.objectid,
1238 ino, orig_offset, 0);
1239 BUG_ON(ret); /* -ENOMEM */
1240 }
1241 if (del_nr == 0) {
1242 fi = btrfs_item_ptr(leaf, path->slots[0],
1243 struct btrfs_file_extent_item);
1244 btrfs_set_file_extent_type(leaf, fi,
1245 BTRFS_FILE_EXTENT_REG);
1246 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1247 btrfs_mark_buffer_dirty(leaf);
1248 } else {
1249 fi = btrfs_item_ptr(leaf, del_slot - 1,
1250 struct btrfs_file_extent_item);
1251 btrfs_set_file_extent_type(leaf, fi,
1252 BTRFS_FILE_EXTENT_REG);
1253 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1254 btrfs_set_file_extent_num_bytes(leaf, fi,
1255 extent_end - key.offset);
1256 btrfs_mark_buffer_dirty(leaf);
1257
1258 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1259 if (ret < 0) {
1260 btrfs_abort_transaction(trans, root, ret);
1261 goto out;
1262 }
1263 }
1264out:
1265 btrfs_free_path(path);
1266 return 0;
1267}
1268
1269/*
1270 * on error we return an unlocked page and the error value
1271 * on success we return a locked page and 0
1272 */
1273static int prepare_uptodate_page(struct page *page, u64 pos,
1274 bool force_uptodate)
1275{
1276 int ret = 0;
1277
1278 if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
1279 !PageUptodate(page)) {
1280 ret = btrfs_readpage(NULL, page);
1281 if (ret)
1282 return ret;
1283 lock_page(page);
1284 if (!PageUptodate(page)) {
1285 unlock_page(page);
1286 return -EIO;
1287 }
1288 }
1289 return 0;
1290}
1291
1292/*
1293 * this just gets pages into the page cache and locks them down.
1294 */
1295static noinline int prepare_pages(struct inode *inode, struct page **pages,
1296 size_t num_pages, loff_t pos,
1297 size_t write_bytes, bool force_uptodate)
1298{
1299 int i;
1300 unsigned long index = pos >> PAGE_CACHE_SHIFT;
1301 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1302 int err = 0;
1303 int faili;
1304
1305 for (i = 0; i < num_pages; i++) {
1306 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1307 mask | __GFP_WRITE);
1308 if (!pages[i]) {
1309 faili = i - 1;
1310 err = -ENOMEM;
1311 goto fail;
1312 }
1313
1314 if (i == 0)
1315 err = prepare_uptodate_page(pages[i], pos,
1316 force_uptodate);
1317 if (i == num_pages - 1)
1318 err = prepare_uptodate_page(pages[i],
1319 pos + write_bytes, false);
1320 if (err) {
1321 page_cache_release(pages[i]);
1322 faili = i - 1;
1323 goto fail;
1324 }
1325 wait_on_page_writeback(pages[i]);
1326 }
1327
1328 return 0;
1329fail:
1330 while (faili >= 0) {
1331 unlock_page(pages[faili]);
1332 page_cache_release(pages[faili]);
1333 faili--;
1334 }
1335 return err;
1336
1337}
1338
1339/*
1340 * This function locks the extent and properly waits for data=ordered extents
1341 * to finish before allowing the pages to be modified if need.
1342 *
1343 * The return value:
1344 * 1 - the extent is locked
1345 * 0 - the extent is not locked, and everything is OK
1346 * -EAGAIN - need re-prepare the pages
1347 * the other < 0 number - Something wrong happens
1348 */
1349static noinline int
1350lock_and_cleanup_extent_if_need(struct inode *inode, struct page **pages,
1351 size_t num_pages, loff_t pos,
1352 u64 *lockstart, u64 *lockend,
1353 struct extent_state **cached_state)
1354{
1355 u64 start_pos;
1356 u64 last_pos;
1357 int i;
1358 int ret = 0;
1359
1360 start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
1361 last_pos = start_pos + ((u64)num_pages << PAGE_CACHE_SHIFT) - 1;
1362
1363 if (start_pos < inode->i_size) {
1364 struct btrfs_ordered_extent *ordered;
1365 lock_extent_bits(&BTRFS_I(inode)->io_tree,
1366 start_pos, last_pos, 0, cached_state);
1367 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1368 last_pos - start_pos + 1);
1369 if (ordered &&
1370 ordered->file_offset + ordered->len > start_pos &&
1371 ordered->file_offset <= last_pos) {
1372 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1373 start_pos, last_pos,
1374 cached_state, GFP_NOFS);
1375 for (i = 0; i < num_pages; i++) {
1376 unlock_page(pages[i]);
1377 page_cache_release(pages[i]);
1378 }
1379 btrfs_start_ordered_extent(inode, ordered, 1);
1380 btrfs_put_ordered_extent(ordered);
1381 return -EAGAIN;
1382 }
1383 if (ordered)
1384 btrfs_put_ordered_extent(ordered);
1385
1386 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
1387 last_pos, EXTENT_DIRTY | EXTENT_DELALLOC |
1388 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
1389 0, 0, cached_state, GFP_NOFS);
1390 *lockstart = start_pos;
1391 *lockend = last_pos;
1392 ret = 1;
1393 }
1394
1395 for (i = 0; i < num_pages; i++) {
1396 if (clear_page_dirty_for_io(pages[i]))
1397 account_page_redirty(pages[i]);
1398 set_page_extent_mapped(pages[i]);
1399 WARN_ON(!PageLocked(pages[i]));
1400 }
1401
1402 return ret;
1403}
1404
1405static noinline int check_can_nocow(struct inode *inode, loff_t pos,
1406 size_t *write_bytes)
1407{
1408 struct btrfs_root *root = BTRFS_I(inode)->root;
1409 struct btrfs_ordered_extent *ordered;
1410 u64 lockstart, lockend;
1411 u64 num_bytes;
1412 int ret;
1413
1414 ret = btrfs_start_nocow_write(root);
1415 if (!ret)
1416 return -ENOSPC;
1417
1418 lockstart = round_down(pos, root->sectorsize);
1419 lockend = round_up(pos + *write_bytes, root->sectorsize) - 1;
1420
1421 while (1) {
1422 lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1423 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1424 lockend - lockstart + 1);
1425 if (!ordered) {
1426 break;
1427 }
1428 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1429 btrfs_start_ordered_extent(inode, ordered, 1);
1430 btrfs_put_ordered_extent(ordered);
1431 }
1432
1433 num_bytes = lockend - lockstart + 1;
1434 ret = can_nocow_extent(inode, lockstart, &num_bytes, NULL, NULL, NULL);
1435 if (ret <= 0) {
1436 ret = 0;
1437 btrfs_end_nocow_write(root);
1438 } else {
1439 *write_bytes = min_t(size_t, *write_bytes ,
1440 num_bytes - pos + lockstart);
1441 }
1442
1443 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1444
1445 return ret;
1446}
1447
1448static noinline ssize_t __btrfs_buffered_write(struct file *file,
1449 struct iov_iter *i,
1450 loff_t pos)
1451{
1452 struct inode *inode = file_inode(file);
1453 struct btrfs_root *root = BTRFS_I(inode)->root;
1454 struct page **pages = NULL;
1455 struct extent_state *cached_state = NULL;
1456 u64 release_bytes = 0;
1457 u64 lockstart;
1458 u64 lockend;
1459 unsigned long first_index;
1460 size_t num_written = 0;
1461 int nrptrs;
1462 int ret = 0;
1463 bool only_release_metadata = false;
1464 bool force_page_uptodate = false;
1465 bool need_unlock;
1466
1467 nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
1468 PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
1469 (sizeof(struct page *)));
1470 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1471 nrptrs = max(nrptrs, 8);
1472 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
1473 if (!pages)
1474 return -ENOMEM;
1475
1476 first_index = pos >> PAGE_CACHE_SHIFT;
1477
1478 while (iov_iter_count(i) > 0) {
1479 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
1480 size_t write_bytes = min(iov_iter_count(i),
1481 nrptrs * (size_t)PAGE_CACHE_SIZE -
1482 offset);
1483 size_t num_pages = (write_bytes + offset +
1484 PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1485 size_t reserve_bytes;
1486 size_t dirty_pages;
1487 size_t copied;
1488
1489 WARN_ON(num_pages > nrptrs);
1490
1491 /*
1492 * Fault pages before locking them in prepare_pages
1493 * to avoid recursive lock
1494 */
1495 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1496 ret = -EFAULT;
1497 break;
1498 }
1499
1500 reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
1501 ret = btrfs_check_data_free_space(inode, reserve_bytes);
1502 if (ret == -ENOSPC &&
1503 (BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1504 BTRFS_INODE_PREALLOC))) {
1505 ret = check_can_nocow(inode, pos, &write_bytes);
1506 if (ret > 0) {
1507 only_release_metadata = true;
1508 /*
1509 * our prealloc extent may be smaller than
1510 * write_bytes, so scale down.
1511 */
1512 num_pages = (write_bytes + offset +
1513 PAGE_CACHE_SIZE - 1) >>
1514 PAGE_CACHE_SHIFT;
1515 reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
1516 ret = 0;
1517 } else {
1518 ret = -ENOSPC;
1519 }
1520 }
1521
1522 if (ret)
1523 break;
1524
1525 ret = btrfs_delalloc_reserve_metadata(inode, reserve_bytes);
1526 if (ret) {
1527 if (!only_release_metadata)
1528 btrfs_free_reserved_data_space(inode,
1529 reserve_bytes);
1530 else
1531 btrfs_end_nocow_write(root);
1532 break;
1533 }
1534
1535 release_bytes = reserve_bytes;
1536 need_unlock = false;
1537again:
1538 /*
1539 * This is going to setup the pages array with the number of
1540 * pages we want, so we don't really need to worry about the
1541 * contents of pages from loop to loop
1542 */
1543 ret = prepare_pages(inode, pages, num_pages,
1544 pos, write_bytes,
1545 force_page_uptodate);
1546 if (ret)
1547 break;
1548
1549 ret = lock_and_cleanup_extent_if_need(inode, pages, num_pages,
1550 pos, &lockstart, &lockend,
1551 &cached_state);
1552 if (ret < 0) {
1553 if (ret == -EAGAIN)
1554 goto again;
1555 break;
1556 } else if (ret > 0) {
1557 need_unlock = true;
1558 ret = 0;
1559 }
1560
1561 copied = btrfs_copy_from_user(pos, num_pages,
1562 write_bytes, pages, i);
1563
1564 /*
1565 * if we have trouble faulting in the pages, fall
1566 * back to one page at a time
1567 */
1568 if (copied < write_bytes)
1569 nrptrs = 1;
1570
1571 if (copied == 0) {
1572 force_page_uptodate = true;
1573 dirty_pages = 0;
1574 } else {
1575 force_page_uptodate = false;
1576 dirty_pages = (copied + offset +
1577 PAGE_CACHE_SIZE - 1) >>
1578 PAGE_CACHE_SHIFT;
1579 }
1580
1581 /*
1582 * If we had a short copy we need to release the excess delaloc
1583 * bytes we reserved. We need to increment outstanding_extents
1584 * because btrfs_delalloc_release_space will decrement it, but
1585 * we still have an outstanding extent for the chunk we actually
1586 * managed to copy.
1587 */
1588 if (num_pages > dirty_pages) {
1589 release_bytes = (num_pages - dirty_pages) <<
1590 PAGE_CACHE_SHIFT;
1591 if (copied > 0) {
1592 spin_lock(&BTRFS_I(inode)->lock);
1593 BTRFS_I(inode)->outstanding_extents++;
1594 spin_unlock(&BTRFS_I(inode)->lock);
1595 }
1596 if (only_release_metadata)
1597 btrfs_delalloc_release_metadata(inode,
1598 release_bytes);
1599 else
1600 btrfs_delalloc_release_space(inode,
1601 release_bytes);
1602 }
1603
1604 release_bytes = dirty_pages << PAGE_CACHE_SHIFT;
1605
1606 if (copied > 0)
1607 ret = btrfs_dirty_pages(root, inode, pages,
1608 dirty_pages, pos, copied,
1609 NULL);
1610 if (need_unlock)
1611 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1612 lockstart, lockend, &cached_state,
1613 GFP_NOFS);
1614 if (ret) {
1615 btrfs_drop_pages(pages, num_pages);
1616 break;
1617 }
1618
1619 release_bytes = 0;
1620 if (only_release_metadata)
1621 btrfs_end_nocow_write(root);
1622
1623 if (only_release_metadata && copied > 0) {
1624 u64 lockstart = round_down(pos, root->sectorsize);
1625 u64 lockend = lockstart +
1626 (dirty_pages << PAGE_CACHE_SHIFT) - 1;
1627
1628 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1629 lockend, EXTENT_NORESERVE, NULL,
1630 NULL, GFP_NOFS);
1631 only_release_metadata = false;
1632 }
1633
1634 btrfs_drop_pages(pages, num_pages);
1635
1636 cond_resched();
1637
1638 balance_dirty_pages_ratelimited(inode->i_mapping);
1639 if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
1640 btrfs_btree_balance_dirty(root);
1641
1642 pos += copied;
1643 num_written += copied;
1644 }
1645
1646 kfree(pages);
1647
1648 if (release_bytes) {
1649 if (only_release_metadata) {
1650 btrfs_end_nocow_write(root);
1651 btrfs_delalloc_release_metadata(inode, release_bytes);
1652 } else {
1653 btrfs_delalloc_release_space(inode, release_bytes);
1654 }
1655 }
1656
1657 return num_written ? num_written : ret;
1658}
1659
1660static ssize_t __btrfs_direct_write(struct kiocb *iocb,
1661 const struct iovec *iov,
1662 unsigned long nr_segs, loff_t pos,
1663 size_t count, size_t ocount)
1664{
1665 struct file *file = iocb->ki_filp;
1666 struct iov_iter i;
1667 ssize_t written;
1668 ssize_t written_buffered;
1669 loff_t endbyte;
1670 int err;
1671
1672 written = generic_file_direct_write(iocb, iov, &nr_segs, pos,
1673 count, ocount);
1674
1675 if (written < 0 || written == count)
1676 return written;
1677
1678 pos += written;
1679 count -= written;
1680 iov_iter_init(&i, iov, nr_segs, count, written);
1681 written_buffered = __btrfs_buffered_write(file, &i, pos);
1682 if (written_buffered < 0) {
1683 err = written_buffered;
1684 goto out;
1685 }
1686 endbyte = pos + written_buffered - 1;
1687 err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
1688 if (err)
1689 goto out;
1690 written += written_buffered;
1691 iocb->ki_pos = pos + written_buffered;
1692 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,
1693 endbyte >> PAGE_CACHE_SHIFT);
1694out:
1695 return written ? written : err;
1696}
1697
1698static void update_time_for_write(struct inode *inode)
1699{
1700 struct timespec now;
1701
1702 if (IS_NOCMTIME(inode))
1703 return;
1704
1705 now = current_fs_time(inode->i_sb);
1706 if (!timespec_equal(&inode->i_mtime, &now))
1707 inode->i_mtime = now;
1708
1709 if (!timespec_equal(&inode->i_ctime, &now))
1710 inode->i_ctime = now;
1711
1712 if (IS_I_VERSION(inode))
1713 inode_inc_iversion(inode);
1714}
1715
1716static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
1717 const struct iovec *iov,
1718 unsigned long nr_segs, loff_t pos)
1719{
1720 struct file *file = iocb->ki_filp;
1721 struct inode *inode = file_inode(file);
1722 struct btrfs_root *root = BTRFS_I(inode)->root;
1723 u64 start_pos;
1724 u64 end_pos;
1725 ssize_t num_written = 0;
1726 ssize_t err = 0;
1727 size_t count, ocount;
1728 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
1729
1730 mutex_lock(&inode->i_mutex);
1731
1732 err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
1733 if (err) {
1734 mutex_unlock(&inode->i_mutex);
1735 goto out;
1736 }
1737 count = ocount;
1738
1739 current->backing_dev_info = inode->i_mapping->backing_dev_info;
1740 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1741 if (err) {
1742 mutex_unlock(&inode->i_mutex);
1743 goto out;
1744 }
1745
1746 if (count == 0) {
1747 mutex_unlock(&inode->i_mutex);
1748 goto out;
1749 }
1750
1751 err = file_remove_suid(file);
1752 if (err) {
1753 mutex_unlock(&inode->i_mutex);
1754 goto out;
1755 }
1756
1757 /*
1758 * If BTRFS flips readonly due to some impossible error
1759 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1760 * although we have opened a file as writable, we have
1761 * to stop this write operation to ensure FS consistency.
1762 */
1763 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1764 mutex_unlock(&inode->i_mutex);
1765 err = -EROFS;
1766 goto out;
1767 }
1768
1769 /*
1770 * We reserve space for updating the inode when we reserve space for the
1771 * extent we are going to write, so we will enospc out there. We don't
1772 * need to start yet another transaction to update the inode as we will
1773 * update the inode when we finish writing whatever data we write.
1774 */
1775 update_time_for_write(inode);
1776
1777 start_pos = round_down(pos, root->sectorsize);
1778 if (start_pos > i_size_read(inode)) {
1779 /* Expand hole size to cover write data, preventing empty gap */
1780 end_pos = round_up(pos + count, root->sectorsize);
1781 err = btrfs_cont_expand(inode, i_size_read(inode), end_pos);
1782 if (err) {
1783 mutex_unlock(&inode->i_mutex);
1784 goto out;
1785 }
1786 }
1787
1788 if (sync)
1789 atomic_inc(&BTRFS_I(inode)->sync_writers);
1790
1791 if (unlikely(file->f_flags & O_DIRECT)) {
1792 num_written = __btrfs_direct_write(iocb, iov, nr_segs,
1793 pos, count, ocount);
1794 } else {
1795 struct iov_iter i;
1796
1797 iov_iter_init(&i, iov, nr_segs, count, num_written);
1798
1799 num_written = __btrfs_buffered_write(file, &i, pos);
1800 if (num_written > 0)
1801 iocb->ki_pos = pos + num_written;
1802 }
1803
1804 mutex_unlock(&inode->i_mutex);
1805
1806 /*
1807 * we want to make sure fsync finds this change
1808 * but we haven't joined a transaction running right now.
1809 *
1810 * Later on, someone is sure to update the inode and get the
1811 * real transid recorded.
1812 *
1813 * We set last_trans now to the fs_info generation + 1,
1814 * this will either be one more than the running transaction
1815 * or the generation used for the next transaction if there isn't
1816 * one running right now.
1817 *
1818 * We also have to set last_sub_trans to the current log transid,
1819 * otherwise subsequent syncs to a file that's been synced in this
1820 * transaction will appear to have already occured.
1821 */
1822 BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
1823 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1824 if (num_written > 0) {
1825 err = generic_write_sync(file, pos, num_written);
1826 if (err < 0)
1827 num_written = err;
1828 }
1829
1830 if (sync)
1831 atomic_dec(&BTRFS_I(inode)->sync_writers);
1832out:
1833 current->backing_dev_info = NULL;
1834 return num_written ? num_written : err;
1835}
1836
1837int btrfs_release_file(struct inode *inode, struct file *filp)
1838{
1839 /*
1840 * ordered_data_close is set by settattr when we are about to truncate
1841 * a file from a non-zero size to a zero size. This tries to
1842 * flush down new bytes that may have been written if the
1843 * application were using truncate to replace a file in place.
1844 */
1845 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
1846 &BTRFS_I(inode)->runtime_flags)) {
1847 struct btrfs_trans_handle *trans;
1848 struct btrfs_root *root = BTRFS_I(inode)->root;
1849
1850 /*
1851 * We need to block on a committing transaction to keep us from
1852 * throwing a ordered operation on to the list and causing
1853 * something like sync to deadlock trying to flush out this
1854 * inode.
1855 */
1856 trans = btrfs_start_transaction(root, 0);
1857 if (IS_ERR(trans))
1858 return PTR_ERR(trans);
1859 btrfs_add_ordered_operation(trans, BTRFS_I(inode)->root, inode);
1860 btrfs_end_transaction(trans, root);
1861 if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
1862 filemap_flush(inode->i_mapping);
1863 }
1864 if (filp->private_data)
1865 btrfs_ioctl_trans_end(filp);
1866 return 0;
1867}
1868
1869/*
1870 * fsync call for both files and directories. This logs the inode into
1871 * the tree log instead of forcing full commits whenever possible.
1872 *
1873 * It needs to call filemap_fdatawait so that all ordered extent updates are
1874 * in the metadata btree are up to date for copying to the log.
1875 *
1876 * It drops the inode mutex before doing the tree log commit. This is an
1877 * important optimization for directories because holding the mutex prevents
1878 * new operations on the dir while we write to disk.
1879 */
1880int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
1881{
1882 struct dentry *dentry = file->f_path.dentry;
1883 struct inode *inode = dentry->d_inode;
1884 struct btrfs_root *root = BTRFS_I(inode)->root;
1885 struct btrfs_trans_handle *trans;
1886 struct btrfs_log_ctx ctx;
1887 int ret = 0;
1888 bool full_sync = 0;
1889
1890 trace_btrfs_sync_file(file, datasync);
1891
1892 /*
1893 * We write the dirty pages in the range and wait until they complete
1894 * out of the ->i_mutex. If so, we can flush the dirty pages by
1895 * multi-task, and make the performance up. See
1896 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
1897 */
1898 atomic_inc(&BTRFS_I(inode)->sync_writers);
1899 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
1900 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1901 &BTRFS_I(inode)->runtime_flags))
1902 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
1903 atomic_dec(&BTRFS_I(inode)->sync_writers);
1904 if (ret)
1905 return ret;
1906
1907 mutex_lock(&inode->i_mutex);
1908
1909 /*
1910 * We flush the dirty pages again to avoid some dirty pages in the
1911 * range being left.
1912 */
1913 atomic_inc(&root->log_batch);
1914 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1915 &BTRFS_I(inode)->runtime_flags);
1916 if (full_sync) {
1917 ret = btrfs_wait_ordered_range(inode, start, end - start + 1);
1918 if (ret) {
1919 mutex_unlock(&inode->i_mutex);
1920 goto out;
1921 }
1922 }
1923 atomic_inc(&root->log_batch);
1924
1925 /*
1926 * check the transaction that last modified this inode
1927 * and see if its already been committed
1928 */
1929 if (!BTRFS_I(inode)->last_trans) {
1930 mutex_unlock(&inode->i_mutex);
1931 goto out;
1932 }
1933
1934 /*
1935 * if the last transaction that changed this file was before
1936 * the current transaction, we can bail out now without any
1937 * syncing
1938 */
1939 smp_mb();
1940 if (btrfs_inode_in_log(inode, root->fs_info->generation) ||
1941 BTRFS_I(inode)->last_trans <=
1942 root->fs_info->last_trans_committed) {
1943 BTRFS_I(inode)->last_trans = 0;
1944
1945 /*
1946 * We'v had everything committed since the last time we were
1947 * modified so clear this flag in case it was set for whatever
1948 * reason, it's no longer relevant.
1949 */
1950 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1951 &BTRFS_I(inode)->runtime_flags);
1952 mutex_unlock(&inode->i_mutex);
1953 goto out;
1954 }
1955
1956 /*
1957 * ok we haven't committed the transaction yet, lets do a commit
1958 */
1959 if (file->private_data)
1960 btrfs_ioctl_trans_end(file);
1961
1962 /*
1963 * We use start here because we will need to wait on the IO to complete
1964 * in btrfs_sync_log, which could require joining a transaction (for
1965 * example checking cross references in the nocow path). If we use join
1966 * here we could get into a situation where we're waiting on IO to
1967 * happen that is blocked on a transaction trying to commit. With start
1968 * we inc the extwriter counter, so we wait for all extwriters to exit
1969 * before we start blocking join'ers. This comment is to keep somebody
1970 * from thinking they are super smart and changing this to
1971 * btrfs_join_transaction *cough*Josef*cough*.
1972 */
1973 trans = btrfs_start_transaction(root, 0);
1974 if (IS_ERR(trans)) {
1975 ret = PTR_ERR(trans);
1976 mutex_unlock(&inode->i_mutex);
1977 goto out;
1978 }
1979 trans->sync = true;
1980
1981 btrfs_init_log_ctx(&ctx);
1982
1983 ret = btrfs_log_dentry_safe(trans, root, dentry, &ctx);
1984 if (ret < 0) {
1985 /* Fallthrough and commit/free transaction. */
1986 ret = 1;
1987 }
1988
1989 /* we've logged all the items and now have a consistent
1990 * version of the file in the log. It is possible that
1991 * someone will come in and modify the file, but that's
1992 * fine because the log is consistent on disk, and we
1993 * have references to all of the file's extents
1994 *
1995 * It is possible that someone will come in and log the
1996 * file again, but that will end up using the synchronization
1997 * inside btrfs_sync_log to keep things safe.
1998 */
1999 mutex_unlock(&inode->i_mutex);
2000
2001 if (ret != BTRFS_NO_LOG_SYNC) {
2002 if (!ret) {
2003 ret = btrfs_sync_log(trans, root, &ctx);
2004 if (!ret) {
2005 ret = btrfs_end_transaction(trans, root);
2006 goto out;
2007 }
2008 }
2009 if (!full_sync) {
2010 ret = btrfs_wait_ordered_range(inode, start,
2011 end - start + 1);
2012 if (ret)
2013 goto out;
2014 }
2015 ret = btrfs_commit_transaction(trans, root);
2016 } else {
2017 ret = btrfs_end_transaction(trans, root);
2018 }
2019out:
2020 return ret > 0 ? -EIO : ret;
2021}
2022
2023static const struct vm_operations_struct btrfs_file_vm_ops = {
2024 .fault = filemap_fault,
2025 .map_pages = filemap_map_pages,
2026 .page_mkwrite = btrfs_page_mkwrite,
2027 .remap_pages = generic_file_remap_pages,
2028};
2029
2030static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2031{
2032 struct address_space *mapping = filp->f_mapping;
2033
2034 if (!mapping->a_ops->readpage)
2035 return -ENOEXEC;
2036
2037 file_accessed(filp);
2038 vma->vm_ops = &btrfs_file_vm_ops;
2039
2040 return 0;
2041}
2042
2043static int hole_mergeable(struct inode *inode, struct extent_buffer *leaf,
2044 int slot, u64 start, u64 end)
2045{
2046 struct btrfs_file_extent_item *fi;
2047 struct btrfs_key key;
2048
2049 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2050 return 0;
2051
2052 btrfs_item_key_to_cpu(leaf, &key, slot);
2053 if (key.objectid != btrfs_ino(inode) ||
2054 key.type != BTRFS_EXTENT_DATA_KEY)
2055 return 0;
2056
2057 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2058
2059 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2060 return 0;
2061
2062 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2063 return 0;
2064
2065 if (key.offset == end)
2066 return 1;
2067 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2068 return 1;
2069 return 0;
2070}
2071
2072static int fill_holes(struct btrfs_trans_handle *trans, struct inode *inode,
2073 struct btrfs_path *path, u64 offset, u64 end)
2074{
2075 struct btrfs_root *root = BTRFS_I(inode)->root;
2076 struct extent_buffer *leaf;
2077 struct btrfs_file_extent_item *fi;
2078 struct extent_map *hole_em;
2079 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2080 struct btrfs_key key;
2081 int ret;
2082
2083 if (btrfs_fs_incompat(root->fs_info, NO_HOLES))
2084 goto out;
2085
2086 key.objectid = btrfs_ino(inode);
2087 key.type = BTRFS_EXTENT_DATA_KEY;
2088 key.offset = offset;
2089
2090 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2091 if (ret < 0)
2092 return ret;
2093 BUG_ON(!ret);
2094
2095 leaf = path->nodes[0];
2096 if (hole_mergeable(inode, leaf, path->slots[0]-1, offset, end)) {
2097 u64 num_bytes;
2098
2099 path->slots[0]--;
2100 fi = btrfs_item_ptr(leaf, path->slots[0],
2101 struct btrfs_file_extent_item);
2102 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2103 end - offset;
2104 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2105 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2106 btrfs_set_file_extent_offset(leaf, fi, 0);
2107 btrfs_mark_buffer_dirty(leaf);
2108 goto out;
2109 }
2110
2111 if (hole_mergeable(inode, leaf, path->slots[0]+1, offset, end)) {
2112 u64 num_bytes;
2113
2114 path->slots[0]++;
2115 key.offset = offset;
2116 btrfs_set_item_key_safe(root, path, &key);
2117 fi = btrfs_item_ptr(leaf, path->slots[0],
2118 struct btrfs_file_extent_item);
2119 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2120 offset;
2121 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2122 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2123 btrfs_set_file_extent_offset(leaf, fi, 0);
2124 btrfs_mark_buffer_dirty(leaf);
2125 goto out;
2126 }
2127 btrfs_release_path(path);
2128
2129 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
2130 0, 0, end - offset, 0, end - offset,
2131 0, 0, 0);
2132 if (ret)
2133 return ret;
2134
2135out:
2136 btrfs_release_path(path);
2137
2138 hole_em = alloc_extent_map();
2139 if (!hole_em) {
2140 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2141 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2142 &BTRFS_I(inode)->runtime_flags);
2143 } else {
2144 hole_em->start = offset;
2145 hole_em->len = end - offset;
2146 hole_em->ram_bytes = hole_em->len;
2147 hole_em->orig_start = offset;
2148
2149 hole_em->block_start = EXTENT_MAP_HOLE;
2150 hole_em->block_len = 0;
2151 hole_em->orig_block_len = 0;
2152 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
2153 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2154 hole_em->generation = trans->transid;
2155
2156 do {
2157 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2158 write_lock(&em_tree->lock);
2159 ret = add_extent_mapping(em_tree, hole_em, 1);
2160 write_unlock(&em_tree->lock);
2161 } while (ret == -EEXIST);
2162 free_extent_map(hole_em);
2163 if (ret)
2164 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2165 &BTRFS_I(inode)->runtime_flags);
2166 }
2167
2168 return 0;
2169}
2170
2171static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2172{
2173 struct btrfs_root *root = BTRFS_I(inode)->root;
2174 struct extent_state *cached_state = NULL;
2175 struct btrfs_path *path;
2176 struct btrfs_block_rsv *rsv;
2177 struct btrfs_trans_handle *trans;
2178 u64 lockstart = round_up(offset, BTRFS_I(inode)->root->sectorsize);
2179 u64 lockend = round_down(offset + len,
2180 BTRFS_I(inode)->root->sectorsize) - 1;
2181 u64 cur_offset = lockstart;
2182 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
2183 u64 drop_end;
2184 int ret = 0;
2185 int err = 0;
2186 int rsv_count;
2187 bool same_page = ((offset >> PAGE_CACHE_SHIFT) ==
2188 ((offset + len - 1) >> PAGE_CACHE_SHIFT));
2189 bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES);
2190 u64 ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE);
2191
2192 ret = btrfs_wait_ordered_range(inode, offset, len);
2193 if (ret)
2194 return ret;
2195
2196 mutex_lock(&inode->i_mutex);
2197 /*
2198 * We needn't truncate any page which is beyond the end of the file
2199 * because we are sure there is no data there.
2200 */
2201 /*
2202 * Only do this if we are in the same page and we aren't doing the
2203 * entire page.
2204 */
2205 if (same_page && len < PAGE_CACHE_SIZE) {
2206 if (offset < ino_size)
2207 ret = btrfs_truncate_page(inode, offset, len, 0);
2208 mutex_unlock(&inode->i_mutex);
2209 return ret;
2210 }
2211
2212 /* zero back part of the first page */
2213 if (offset < ino_size) {
2214 ret = btrfs_truncate_page(inode, offset, 0, 0);
2215 if (ret) {
2216 mutex_unlock(&inode->i_mutex);
2217 return ret;
2218 }
2219 }
2220
2221 /* zero the front end of the last page */
2222 if (offset + len < ino_size) {
2223 ret = btrfs_truncate_page(inode, offset + len, 0, 1);
2224 if (ret) {
2225 mutex_unlock(&inode->i_mutex);
2226 return ret;
2227 }
2228 }
2229
2230 if (lockend < lockstart) {
2231 mutex_unlock(&inode->i_mutex);
2232 return 0;
2233 }
2234
2235 while (1) {
2236 struct btrfs_ordered_extent *ordered;
2237
2238 truncate_pagecache_range(inode, lockstart, lockend);
2239
2240 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2241 0, &cached_state);
2242 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2243
2244 /*
2245 * We need to make sure we have no ordered extents in this range
2246 * and nobody raced in and read a page in this range, if we did
2247 * we need to try again.
2248 */
2249 if ((!ordered ||
2250 (ordered->file_offset + ordered->len <= lockstart ||
2251 ordered->file_offset > lockend)) &&
2252 !test_range_bit(&BTRFS_I(inode)->io_tree, lockstart,
2253 lockend, EXTENT_UPTODATE, 0,
2254 cached_state)) {
2255 if (ordered)
2256 btrfs_put_ordered_extent(ordered);
2257 break;
2258 }
2259 if (ordered)
2260 btrfs_put_ordered_extent(ordered);
2261 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2262 lockend, &cached_state, GFP_NOFS);
2263 ret = btrfs_wait_ordered_range(inode, lockstart,
2264 lockend - lockstart + 1);
2265 if (ret) {
2266 mutex_unlock(&inode->i_mutex);
2267 return ret;
2268 }
2269 }
2270
2271 path = btrfs_alloc_path();
2272 if (!path) {
2273 ret = -ENOMEM;
2274 goto out;
2275 }
2276
2277 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2278 if (!rsv) {
2279 ret = -ENOMEM;
2280 goto out_free;
2281 }
2282 rsv->size = btrfs_calc_trunc_metadata_size(root, 1);
2283 rsv->failfast = 1;
2284
2285 /*
2286 * 1 - update the inode
2287 * 1 - removing the extents in the range
2288 * 1 - adding the hole extent if no_holes isn't set
2289 */
2290 rsv_count = no_holes ? 2 : 3;
2291 trans = btrfs_start_transaction(root, rsv_count);
2292 if (IS_ERR(trans)) {
2293 err = PTR_ERR(trans);
2294 goto out_free;
2295 }
2296
2297 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
2298 min_size);
2299 BUG_ON(ret);
2300 trans->block_rsv = rsv;
2301
2302 while (cur_offset < lockend) {
2303 ret = __btrfs_drop_extents(trans, root, inode, path,
2304 cur_offset, lockend + 1,
2305 &drop_end, 1, 0, 0, NULL);
2306 if (ret != -ENOSPC)
2307 break;
2308
2309 trans->block_rsv = &root->fs_info->trans_block_rsv;
2310
2311 if (cur_offset < ino_size) {
2312 ret = fill_holes(trans, inode, path, cur_offset,
2313 drop_end);
2314 if (ret) {
2315 err = ret;
2316 break;
2317 }
2318 }
2319
2320 cur_offset = drop_end;
2321
2322 ret = btrfs_update_inode(trans, root, inode);
2323 if (ret) {
2324 err = ret;
2325 break;
2326 }
2327
2328 btrfs_end_transaction(trans, root);
2329 btrfs_btree_balance_dirty(root);
2330
2331 trans = btrfs_start_transaction(root, rsv_count);
2332 if (IS_ERR(trans)) {
2333 ret = PTR_ERR(trans);
2334 trans = NULL;
2335 break;
2336 }
2337
2338 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
2339 rsv, min_size);
2340 BUG_ON(ret); /* shouldn't happen */
2341 trans->block_rsv = rsv;
2342 }
2343
2344 if (ret) {
2345 err = ret;
2346 goto out_trans;
2347 }
2348
2349 trans->block_rsv = &root->fs_info->trans_block_rsv;
2350 if (cur_offset < ino_size) {
2351 ret = fill_holes(trans, inode, path, cur_offset, drop_end);
2352 if (ret) {
2353 err = ret;
2354 goto out_trans;
2355 }
2356 }
2357
2358out_trans:
2359 if (!trans)
2360 goto out_free;
2361
2362 inode_inc_iversion(inode);
2363 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2364
2365 trans->block_rsv = &root->fs_info->trans_block_rsv;
2366 ret = btrfs_update_inode(trans, root, inode);
2367 btrfs_end_transaction(trans, root);
2368 btrfs_btree_balance_dirty(root);
2369out_free:
2370 btrfs_free_path(path);
2371 btrfs_free_block_rsv(root, rsv);
2372out:
2373 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2374 &cached_state, GFP_NOFS);
2375 mutex_unlock(&inode->i_mutex);
2376 if (ret && !err)
2377 err = ret;
2378 return err;
2379}
2380
2381static long btrfs_fallocate(struct file *file, int mode,
2382 loff_t offset, loff_t len)
2383{
2384 struct inode *inode = file_inode(file);
2385 struct extent_state *cached_state = NULL;
2386 struct btrfs_root *root = BTRFS_I(inode)->root;
2387 u64 cur_offset;
2388 u64 last_byte;
2389 u64 alloc_start;
2390 u64 alloc_end;
2391 u64 alloc_hint = 0;
2392 u64 locked_end;
2393 struct extent_map *em;
2394 int blocksize = BTRFS_I(inode)->root->sectorsize;
2395 int ret;
2396
2397 alloc_start = round_down(offset, blocksize);
2398 alloc_end = round_up(offset + len, blocksize);
2399
2400 /* Make sure we aren't being give some crap mode */
2401 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
2402 return -EOPNOTSUPP;
2403
2404 if (mode & FALLOC_FL_PUNCH_HOLE)
2405 return btrfs_punch_hole(inode, offset, len);
2406
2407 /*
2408 * Make sure we have enough space before we do the
2409 * allocation.
2410 */
2411 ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
2412 if (ret)
2413 return ret;
2414 if (root->fs_info->quota_enabled) {
2415 ret = btrfs_qgroup_reserve(root, alloc_end - alloc_start);
2416 if (ret)
2417 goto out_reserve_fail;
2418 }
2419
2420 mutex_lock(&inode->i_mutex);
2421 ret = inode_newsize_ok(inode, alloc_end);
2422 if (ret)
2423 goto out;
2424
2425 if (alloc_start > inode->i_size) {
2426 ret = btrfs_cont_expand(inode, i_size_read(inode),
2427 alloc_start);
2428 if (ret)
2429 goto out;
2430 } else {
2431 /*
2432 * If we are fallocating from the end of the file onward we
2433 * need to zero out the end of the page if i_size lands in the
2434 * middle of a page.
2435 */
2436 ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
2437 if (ret)
2438 goto out;
2439 }
2440
2441 /*
2442 * wait for ordered IO before we have any locks. We'll loop again
2443 * below with the locks held.
2444 */
2445 ret = btrfs_wait_ordered_range(inode, alloc_start,
2446 alloc_end - alloc_start);
2447 if (ret)
2448 goto out;
2449
2450 locked_end = alloc_end - 1;
2451 while (1) {
2452 struct btrfs_ordered_extent *ordered;
2453
2454 /* the extent lock is ordered inside the running
2455 * transaction
2456 */
2457 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
2458 locked_end, 0, &cached_state);
2459 ordered = btrfs_lookup_first_ordered_extent(inode,
2460 alloc_end - 1);
2461 if (ordered &&
2462 ordered->file_offset + ordered->len > alloc_start &&
2463 ordered->file_offset < alloc_end) {
2464 btrfs_put_ordered_extent(ordered);
2465 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
2466 alloc_start, locked_end,
2467 &cached_state, GFP_NOFS);
2468 /*
2469 * we can't wait on the range with the transaction
2470 * running or with the extent lock held
2471 */
2472 ret = btrfs_wait_ordered_range(inode, alloc_start,
2473 alloc_end - alloc_start);
2474 if (ret)
2475 goto out;
2476 } else {
2477 if (ordered)
2478 btrfs_put_ordered_extent(ordered);
2479 break;
2480 }
2481 }
2482
2483 cur_offset = alloc_start;
2484 while (1) {
2485 u64 actual_end;
2486
2487 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
2488 alloc_end - cur_offset, 0);
2489 if (IS_ERR_OR_NULL(em)) {
2490 if (!em)
2491 ret = -ENOMEM;
2492 else
2493 ret = PTR_ERR(em);
2494 break;
2495 }
2496 last_byte = min(extent_map_end(em), alloc_end);
2497 actual_end = min_t(u64, extent_map_end(em), offset + len);
2498 last_byte = ALIGN(last_byte, blocksize);
2499
2500 if (em->block_start == EXTENT_MAP_HOLE ||
2501 (cur_offset >= inode->i_size &&
2502 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
2503 ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
2504 last_byte - cur_offset,
2505 1 << inode->i_blkbits,
2506 offset + len,
2507 &alloc_hint);
2508
2509 if (ret < 0) {
2510 free_extent_map(em);
2511 break;
2512 }
2513 } else if (actual_end > inode->i_size &&
2514 !(mode & FALLOC_FL_KEEP_SIZE)) {
2515 /*
2516 * We didn't need to allocate any more space, but we
2517 * still extended the size of the file so we need to
2518 * update i_size.
2519 */
2520 inode->i_ctime = CURRENT_TIME;
2521 i_size_write(inode, actual_end);
2522 btrfs_ordered_update_i_size(inode, actual_end, NULL);
2523 }
2524 free_extent_map(em);
2525
2526 cur_offset = last_byte;
2527 if (cur_offset >= alloc_end) {
2528 ret = 0;
2529 break;
2530 }
2531 }
2532 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
2533 &cached_state, GFP_NOFS);
2534out:
2535 mutex_unlock(&inode->i_mutex);
2536 if (root->fs_info->quota_enabled)
2537 btrfs_qgroup_free(root, alloc_end - alloc_start);
2538out_reserve_fail:
2539 /* Let go of our reservation. */
2540 btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
2541 return ret;
2542}
2543
2544static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
2545{
2546 struct btrfs_root *root = BTRFS_I(inode)->root;
2547 struct extent_map *em = NULL;
2548 struct extent_state *cached_state = NULL;
2549 u64 lockstart = *offset;
2550 u64 lockend = i_size_read(inode);
2551 u64 start = *offset;
2552 u64 len = i_size_read(inode);
2553 int ret = 0;
2554
2555 lockend = max_t(u64, root->sectorsize, lockend);
2556 if (lockend <= lockstart)
2557 lockend = lockstart + root->sectorsize;
2558
2559 lockend--;
2560 len = lockend - lockstart + 1;
2561
2562 len = max_t(u64, len, root->sectorsize);
2563 if (inode->i_size == 0)
2564 return -ENXIO;
2565
2566 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0,
2567 &cached_state);
2568
2569 while (start < inode->i_size) {
2570 em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
2571 if (IS_ERR(em)) {
2572 ret = PTR_ERR(em);
2573 em = NULL;
2574 break;
2575 }
2576
2577 if (whence == SEEK_HOLE &&
2578 (em->block_start == EXTENT_MAP_HOLE ||
2579 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
2580 break;
2581 else if (whence == SEEK_DATA &&
2582 (em->block_start != EXTENT_MAP_HOLE &&
2583 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
2584 break;
2585
2586 start = em->start + em->len;
2587 free_extent_map(em);
2588 em = NULL;
2589 cond_resched();
2590 }
2591 free_extent_map(em);
2592 if (!ret) {
2593 if (whence == SEEK_DATA && start >= inode->i_size)
2594 ret = -ENXIO;
2595 else
2596 *offset = min_t(loff_t, start, inode->i_size);
2597 }
2598 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2599 &cached_state, GFP_NOFS);
2600 return ret;
2601}
2602
2603static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
2604{
2605 struct inode *inode = file->f_mapping->host;
2606 int ret;
2607
2608 mutex_lock(&inode->i_mutex);
2609 switch (whence) {
2610 case SEEK_END:
2611 case SEEK_CUR:
2612 offset = generic_file_llseek(file, offset, whence);
2613 goto out;
2614 case SEEK_DATA:
2615 case SEEK_HOLE:
2616 if (offset >= i_size_read(inode)) {
2617 mutex_unlock(&inode->i_mutex);
2618 return -ENXIO;
2619 }
2620
2621 ret = find_desired_extent(inode, &offset, whence);
2622 if (ret) {
2623 mutex_unlock(&inode->i_mutex);
2624 return ret;
2625 }
2626 }
2627
2628 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
2629out:
2630 mutex_unlock(&inode->i_mutex);
2631 return offset;
2632}
2633
2634const struct file_operations btrfs_file_operations = {
2635 .llseek = btrfs_file_llseek,
2636 .read = do_sync_read,
2637 .write = do_sync_write,
2638 .aio_read = generic_file_aio_read,
2639 .splice_read = generic_file_splice_read,
2640 .aio_write = btrfs_file_aio_write,
2641 .mmap = btrfs_file_mmap,
2642 .open = generic_file_open,
2643 .release = btrfs_release_file,
2644 .fsync = btrfs_sync_file,
2645 .fallocate = btrfs_fallocate,
2646 .unlocked_ioctl = btrfs_ioctl,
2647#ifdef CONFIG_COMPAT
2648 .compat_ioctl = btrfs_ioctl,
2649#endif
2650};
2651
2652void btrfs_auto_defrag_exit(void)
2653{
2654 if (btrfs_inode_defrag_cachep)
2655 kmem_cache_destroy(btrfs_inode_defrag_cachep);
2656}
2657
2658int btrfs_auto_defrag_init(void)
2659{
2660 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
2661 sizeof(struct inode_defrag), 0,
2662 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
2663 NULL);
2664 if (!btrfs_inode_defrag_cachep)
2665 return -ENOMEM;
2666
2667 return 0;
2668}