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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}
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/falloc.h>
28#include <linux/swap.h>
29#include <linux/writeback.h>
30#include <linux/statfs.h>
31#include <linux/compat.h>
32#include <linux/slab.h>
33#include "ctree.h"
34#include "disk-io.h"
35#include "transaction.h"
36#include "btrfs_inode.h"
37#include "ioctl.h"
38#include "print-tree.h"
39#include "tree-log.h"
40#include "locking.h"
41#include "compat.h"
42
43/*
44 * when auto defrag is enabled we
45 * queue up these defrag structs to remember which
46 * inodes need defragging passes
47 */
48struct inode_defrag {
49 struct rb_node rb_node;
50 /* objectid */
51 u64 ino;
52 /*
53 * transid where the defrag was added, we search for
54 * extents newer than this
55 */
56 u64 transid;
57
58 /* root objectid */
59 u64 root;
60
61 /* last offset we were able to defrag */
62 u64 last_offset;
63
64 /* if we've wrapped around back to zero once already */
65 int cycled;
66};
67
68static int __compare_inode_defrag(struct inode_defrag *defrag1,
69 struct inode_defrag *defrag2)
70{
71 if (defrag1->root > defrag2->root)
72 return 1;
73 else if (defrag1->root < defrag2->root)
74 return -1;
75 else if (defrag1->ino > defrag2->ino)
76 return 1;
77 else if (defrag1->ino < defrag2->ino)
78 return -1;
79 else
80 return 0;
81}
82
83/* pop a record for an inode into the defrag tree. The lock
84 * must be held already
85 *
86 * If you're inserting a record for an older transid than an
87 * existing record, the transid already in the tree is lowered
88 *
89 * If an existing record is found the defrag item you
90 * pass in is freed
91 */
92static void __btrfs_add_inode_defrag(struct inode *inode,
93 struct inode_defrag *defrag)
94{
95 struct btrfs_root *root = BTRFS_I(inode)->root;
96 struct inode_defrag *entry;
97 struct rb_node **p;
98 struct rb_node *parent = NULL;
99 int ret;
100
101 p = &root->fs_info->defrag_inodes.rb_node;
102 while (*p) {
103 parent = *p;
104 entry = rb_entry(parent, struct inode_defrag, rb_node);
105
106 ret = __compare_inode_defrag(defrag, entry);
107 if (ret < 0)
108 p = &parent->rb_left;
109 else if (ret > 0)
110 p = &parent->rb_right;
111 else {
112 /* if we're reinserting an entry for
113 * an old defrag run, make sure to
114 * lower the transid of our existing record
115 */
116 if (defrag->transid < entry->transid)
117 entry->transid = defrag->transid;
118 if (defrag->last_offset > entry->last_offset)
119 entry->last_offset = defrag->last_offset;
120 goto exists;
121 }
122 }
123 set_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
124 rb_link_node(&defrag->rb_node, parent, p);
125 rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes);
126 return;
127
128exists:
129 kfree(defrag);
130 return;
131
132}
133
134/*
135 * insert a defrag record for this inode if auto defrag is
136 * enabled
137 */
138int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
139 struct inode *inode)
140{
141 struct btrfs_root *root = BTRFS_I(inode)->root;
142 struct inode_defrag *defrag;
143 u64 transid;
144
145 if (!btrfs_test_opt(root, AUTO_DEFRAG))
146 return 0;
147
148 if (btrfs_fs_closing(root->fs_info))
149 return 0;
150
151 if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags))
152 return 0;
153
154 if (trans)
155 transid = trans->transid;
156 else
157 transid = BTRFS_I(inode)->root->last_trans;
158
159 defrag = kzalloc(sizeof(*defrag), GFP_NOFS);
160 if (!defrag)
161 return -ENOMEM;
162
163 defrag->ino = btrfs_ino(inode);
164 defrag->transid = transid;
165 defrag->root = root->root_key.objectid;
166
167 spin_lock(&root->fs_info->defrag_inodes_lock);
168 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags))
169 __btrfs_add_inode_defrag(inode, defrag);
170 else
171 kfree(defrag);
172 spin_unlock(&root->fs_info->defrag_inodes_lock);
173 return 0;
174}
175
176/*
177 * must be called with the defrag_inodes lock held
178 */
179struct inode_defrag *btrfs_find_defrag_inode(struct btrfs_fs_info *info,
180 u64 root, u64 ino,
181 struct rb_node **next)
182{
183 struct inode_defrag *entry = NULL;
184 struct inode_defrag tmp;
185 struct rb_node *p;
186 struct rb_node *parent = NULL;
187 int ret;
188
189 tmp.ino = ino;
190 tmp.root = root;
191
192 p = info->defrag_inodes.rb_node;
193 while (p) {
194 parent = p;
195 entry = rb_entry(parent, struct inode_defrag, rb_node);
196
197 ret = __compare_inode_defrag(&tmp, entry);
198 if (ret < 0)
199 p = parent->rb_left;
200 else if (ret > 0)
201 p = parent->rb_right;
202 else
203 return entry;
204 }
205
206 if (next) {
207 while (parent && __compare_inode_defrag(&tmp, entry) > 0) {
208 parent = rb_next(parent);
209 entry = rb_entry(parent, struct inode_defrag, rb_node);
210 }
211 *next = parent;
212 }
213 return NULL;
214}
215
216/*
217 * run through the list of inodes in the FS that need
218 * defragging
219 */
220int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
221{
222 struct inode_defrag *defrag;
223 struct btrfs_root *inode_root;
224 struct inode *inode;
225 struct rb_node *n;
226 struct btrfs_key key;
227 struct btrfs_ioctl_defrag_range_args range;
228 u64 first_ino = 0;
229 u64 root_objectid = 0;
230 int num_defrag;
231 int defrag_batch = 1024;
232
233 memset(&range, 0, sizeof(range));
234 range.len = (u64)-1;
235
236 atomic_inc(&fs_info->defrag_running);
237 spin_lock(&fs_info->defrag_inodes_lock);
238 while(1) {
239 n = NULL;
240
241 /* find an inode to defrag */
242 defrag = btrfs_find_defrag_inode(fs_info, root_objectid,
243 first_ino, &n);
244 if (!defrag) {
245 if (n) {
246 defrag = rb_entry(n, struct inode_defrag,
247 rb_node);
248 } else if (root_objectid || first_ino) {
249 root_objectid = 0;
250 first_ino = 0;
251 continue;
252 } else {
253 break;
254 }
255 }
256
257 /* remove it from the rbtree */
258 first_ino = defrag->ino + 1;
259 root_objectid = defrag->root;
260 rb_erase(&defrag->rb_node, &fs_info->defrag_inodes);
261
262 if (btrfs_fs_closing(fs_info))
263 goto next_free;
264
265 spin_unlock(&fs_info->defrag_inodes_lock);
266
267 /* get the inode */
268 key.objectid = defrag->root;
269 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
270 key.offset = (u64)-1;
271 inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
272 if (IS_ERR(inode_root))
273 goto next;
274
275 key.objectid = defrag->ino;
276 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
277 key.offset = 0;
278
279 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
280 if (IS_ERR(inode))
281 goto next;
282
283 /* do a chunk of defrag */
284 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
285 range.start = defrag->last_offset;
286 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
287 defrag_batch);
288 /*
289 * if we filled the whole defrag batch, there
290 * must be more work to do. Queue this defrag
291 * again
292 */
293 if (num_defrag == defrag_batch) {
294 defrag->last_offset = range.start;
295 __btrfs_add_inode_defrag(inode, defrag);
296 /*
297 * we don't want to kfree defrag, we added it back to
298 * the rbtree
299 */
300 defrag = NULL;
301 } else if (defrag->last_offset && !defrag->cycled) {
302 /*
303 * we didn't fill our defrag batch, but
304 * we didn't start at zero. Make sure we loop
305 * around to the start of the file.
306 */
307 defrag->last_offset = 0;
308 defrag->cycled = 1;
309 __btrfs_add_inode_defrag(inode, defrag);
310 defrag = NULL;
311 }
312
313 iput(inode);
314next:
315 spin_lock(&fs_info->defrag_inodes_lock);
316next_free:
317 kfree(defrag);
318 }
319 spin_unlock(&fs_info->defrag_inodes_lock);
320
321 atomic_dec(&fs_info->defrag_running);
322
323 /*
324 * during unmount, we use the transaction_wait queue to
325 * wait for the defragger to stop
326 */
327 wake_up(&fs_info->transaction_wait);
328 return 0;
329}
330
331/* simple helper to fault in pages and copy. This should go away
332 * and be replaced with calls into generic code.
333 */
334static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
335 size_t write_bytes,
336 struct page **prepared_pages,
337 struct iov_iter *i)
338{
339 size_t copied = 0;
340 size_t total_copied = 0;
341 int pg = 0;
342 int offset = pos & (PAGE_CACHE_SIZE - 1);
343
344 while (write_bytes > 0) {
345 size_t count = min_t(size_t,
346 PAGE_CACHE_SIZE - offset, write_bytes);
347 struct page *page = prepared_pages[pg];
348 /*
349 * Copy data from userspace to the current page
350 *
351 * Disable pagefault to avoid recursive lock since
352 * the pages are already locked
353 */
354 pagefault_disable();
355 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
356 pagefault_enable();
357
358 /* Flush processor's dcache for this page */
359 flush_dcache_page(page);
360
361 /*
362 * if we get a partial write, we can end up with
363 * partially up to date pages. These add
364 * a lot of complexity, so make sure they don't
365 * happen by forcing this copy to be retried.
366 *
367 * The rest of the btrfs_file_write code will fall
368 * back to page at a time copies after we return 0.
369 */
370 if (!PageUptodate(page) && copied < count)
371 copied = 0;
372
373 iov_iter_advance(i, copied);
374 write_bytes -= copied;
375 total_copied += copied;
376
377 /* Return to btrfs_file_aio_write to fault page */
378 if (unlikely(copied == 0))
379 break;
380
381 if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
382 offset += copied;
383 } else {
384 pg++;
385 offset = 0;
386 }
387 }
388 return total_copied;
389}
390
391/*
392 * unlocks pages after btrfs_file_write is done with them
393 */
394void btrfs_drop_pages(struct page **pages, size_t num_pages)
395{
396 size_t i;
397 for (i = 0; i < num_pages; i++) {
398 /* page checked is some magic around finding pages that
399 * have been modified without going through btrfs_set_page_dirty
400 * clear it here
401 */
402 ClearPageChecked(pages[i]);
403 unlock_page(pages[i]);
404 mark_page_accessed(pages[i]);
405 page_cache_release(pages[i]);
406 }
407}
408
409/*
410 * after copy_from_user, pages need to be dirtied and we need to make
411 * sure holes are created between the current EOF and the start of
412 * any next extents (if required).
413 *
414 * this also makes the decision about creating an inline extent vs
415 * doing real data extents, marking pages dirty and delalloc as required.
416 */
417int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode,
418 struct page **pages, size_t num_pages,
419 loff_t pos, size_t write_bytes,
420 struct extent_state **cached)
421{
422 int err = 0;
423 int i;
424 u64 num_bytes;
425 u64 start_pos;
426 u64 end_of_last_block;
427 u64 end_pos = pos + write_bytes;
428 loff_t isize = i_size_read(inode);
429
430 start_pos = pos & ~((u64)root->sectorsize - 1);
431 num_bytes = (write_bytes + pos - start_pos +
432 root->sectorsize - 1) & ~((u64)root->sectorsize - 1);
433
434 end_of_last_block = start_pos + num_bytes - 1;
435 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
436 cached);
437 if (err)
438 return err;
439
440 for (i = 0; i < num_pages; i++) {
441 struct page *p = pages[i];
442 SetPageUptodate(p);
443 ClearPageChecked(p);
444 set_page_dirty(p);
445 }
446
447 /*
448 * we've only changed i_size in ram, and we haven't updated
449 * the disk i_size. There is no need to log the inode
450 * at this time.
451 */
452 if (end_pos > isize)
453 i_size_write(inode, end_pos);
454 return 0;
455}
456
457/*
458 * this drops all the extents in the cache that intersect the range
459 * [start, end]. Existing extents are split as required.
460 */
461int btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
462 int skip_pinned)
463{
464 struct extent_map *em;
465 struct extent_map *split = NULL;
466 struct extent_map *split2 = NULL;
467 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
468 u64 len = end - start + 1;
469 int ret;
470 int testend = 1;
471 unsigned long flags;
472 int compressed = 0;
473
474 WARN_ON(end < start);
475 if (end == (u64)-1) {
476 len = (u64)-1;
477 testend = 0;
478 }
479 while (1) {
480 if (!split)
481 split = alloc_extent_map();
482 if (!split2)
483 split2 = alloc_extent_map();
484 BUG_ON(!split || !split2); /* -ENOMEM */
485
486 write_lock(&em_tree->lock);
487 em = lookup_extent_mapping(em_tree, start, len);
488 if (!em) {
489 write_unlock(&em_tree->lock);
490 break;
491 }
492 flags = em->flags;
493 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
494 if (testend && em->start + em->len >= start + len) {
495 free_extent_map(em);
496 write_unlock(&em_tree->lock);
497 break;
498 }
499 start = em->start + em->len;
500 if (testend)
501 len = start + len - (em->start + em->len);
502 free_extent_map(em);
503 write_unlock(&em_tree->lock);
504 continue;
505 }
506 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
507 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
508 remove_extent_mapping(em_tree, em);
509
510 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
511 em->start < start) {
512 split->start = em->start;
513 split->len = start - em->start;
514 split->orig_start = em->orig_start;
515 split->block_start = em->block_start;
516
517 if (compressed)
518 split->block_len = em->block_len;
519 else
520 split->block_len = split->len;
521
522 split->bdev = em->bdev;
523 split->flags = flags;
524 split->compress_type = em->compress_type;
525 ret = add_extent_mapping(em_tree, split);
526 BUG_ON(ret); /* Logic error */
527 free_extent_map(split);
528 split = split2;
529 split2 = NULL;
530 }
531 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
532 testend && em->start + em->len > start + len) {
533 u64 diff = start + len - em->start;
534
535 split->start = start + len;
536 split->len = em->start + em->len - (start + len);
537 split->bdev = em->bdev;
538 split->flags = flags;
539 split->compress_type = em->compress_type;
540
541 if (compressed) {
542 split->block_len = em->block_len;
543 split->block_start = em->block_start;
544 split->orig_start = em->orig_start;
545 } else {
546 split->block_len = split->len;
547 split->block_start = em->block_start + diff;
548 split->orig_start = split->start;
549 }
550
551 ret = add_extent_mapping(em_tree, split);
552 BUG_ON(ret); /* Logic error */
553 free_extent_map(split);
554 split = NULL;
555 }
556 write_unlock(&em_tree->lock);
557
558 /* once for us */
559 free_extent_map(em);
560 /* once for the tree*/
561 free_extent_map(em);
562 }
563 if (split)
564 free_extent_map(split);
565 if (split2)
566 free_extent_map(split2);
567 return 0;
568}
569
570/*
571 * this is very complex, but the basic idea is to drop all extents
572 * in the range start - end. hint_block is filled in with a block number
573 * that would be a good hint to the block allocator for this file.
574 *
575 * If an extent intersects the range but is not entirely inside the range
576 * it is either truncated or split. Anything entirely inside the range
577 * is deleted from the tree.
578 */
579int btrfs_drop_extents(struct btrfs_trans_handle *trans, struct inode *inode,
580 u64 start, u64 end, u64 *hint_byte, int drop_cache)
581{
582 struct btrfs_root *root = BTRFS_I(inode)->root;
583 struct extent_buffer *leaf;
584 struct btrfs_file_extent_item *fi;
585 struct btrfs_path *path;
586 struct btrfs_key key;
587 struct btrfs_key new_key;
588 u64 ino = btrfs_ino(inode);
589 u64 search_start = start;
590 u64 disk_bytenr = 0;
591 u64 num_bytes = 0;
592 u64 extent_offset = 0;
593 u64 extent_end = 0;
594 int del_nr = 0;
595 int del_slot = 0;
596 int extent_type;
597 int recow;
598 int ret;
599 int modify_tree = -1;
600
601 if (drop_cache)
602 btrfs_drop_extent_cache(inode, start, end - 1, 0);
603
604 path = btrfs_alloc_path();
605 if (!path)
606 return -ENOMEM;
607
608 if (start >= BTRFS_I(inode)->disk_i_size)
609 modify_tree = 0;
610
611 while (1) {
612 recow = 0;
613 ret = btrfs_lookup_file_extent(trans, root, path, ino,
614 search_start, modify_tree);
615 if (ret < 0)
616 break;
617 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
618 leaf = path->nodes[0];
619 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
620 if (key.objectid == ino &&
621 key.type == BTRFS_EXTENT_DATA_KEY)
622 path->slots[0]--;
623 }
624 ret = 0;
625next_slot:
626 leaf = path->nodes[0];
627 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
628 BUG_ON(del_nr > 0);
629 ret = btrfs_next_leaf(root, path);
630 if (ret < 0)
631 break;
632 if (ret > 0) {
633 ret = 0;
634 break;
635 }
636 leaf = path->nodes[0];
637 recow = 1;
638 }
639
640 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
641 if (key.objectid > ino ||
642 key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
643 break;
644
645 fi = btrfs_item_ptr(leaf, path->slots[0],
646 struct btrfs_file_extent_item);
647 extent_type = btrfs_file_extent_type(leaf, fi);
648
649 if (extent_type == BTRFS_FILE_EXTENT_REG ||
650 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
651 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
652 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
653 extent_offset = btrfs_file_extent_offset(leaf, fi);
654 extent_end = key.offset +
655 btrfs_file_extent_num_bytes(leaf, fi);
656 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
657 extent_end = key.offset +
658 btrfs_file_extent_inline_len(leaf, fi);
659 } else {
660 WARN_ON(1);
661 extent_end = search_start;
662 }
663
664 if (extent_end <= search_start) {
665 path->slots[0]++;
666 goto next_slot;
667 }
668
669 search_start = max(key.offset, start);
670 if (recow || !modify_tree) {
671 modify_tree = -1;
672 btrfs_release_path(path);
673 continue;
674 }
675
676 /*
677 * | - range to drop - |
678 * | -------- extent -------- |
679 */
680 if (start > key.offset && end < extent_end) {
681 BUG_ON(del_nr > 0);
682 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
683
684 memcpy(&new_key, &key, sizeof(new_key));
685 new_key.offset = start;
686 ret = btrfs_duplicate_item(trans, root, path,
687 &new_key);
688 if (ret == -EAGAIN) {
689 btrfs_release_path(path);
690 continue;
691 }
692 if (ret < 0)
693 break;
694
695 leaf = path->nodes[0];
696 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
697 struct btrfs_file_extent_item);
698 btrfs_set_file_extent_num_bytes(leaf, fi,
699 start - key.offset);
700
701 fi = btrfs_item_ptr(leaf, path->slots[0],
702 struct btrfs_file_extent_item);
703
704 extent_offset += start - key.offset;
705 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
706 btrfs_set_file_extent_num_bytes(leaf, fi,
707 extent_end - start);
708 btrfs_mark_buffer_dirty(leaf);
709
710 if (disk_bytenr > 0) {
711 ret = btrfs_inc_extent_ref(trans, root,
712 disk_bytenr, num_bytes, 0,
713 root->root_key.objectid,
714 new_key.objectid,
715 start - extent_offset, 0);
716 BUG_ON(ret); /* -ENOMEM */
717 *hint_byte = disk_bytenr;
718 }
719 key.offset = start;
720 }
721 /*
722 * | ---- range to drop ----- |
723 * | -------- extent -------- |
724 */
725 if (start <= key.offset && end < extent_end) {
726 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
727
728 memcpy(&new_key, &key, sizeof(new_key));
729 new_key.offset = end;
730 btrfs_set_item_key_safe(trans, root, path, &new_key);
731
732 extent_offset += end - key.offset;
733 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
734 btrfs_set_file_extent_num_bytes(leaf, fi,
735 extent_end - end);
736 btrfs_mark_buffer_dirty(leaf);
737 if (disk_bytenr > 0) {
738 inode_sub_bytes(inode, end - key.offset);
739 *hint_byte = disk_bytenr;
740 }
741 break;
742 }
743
744 search_start = extent_end;
745 /*
746 * | ---- range to drop ----- |
747 * | -------- extent -------- |
748 */
749 if (start > key.offset && end >= extent_end) {
750 BUG_ON(del_nr > 0);
751 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
752
753 btrfs_set_file_extent_num_bytes(leaf, fi,
754 start - key.offset);
755 btrfs_mark_buffer_dirty(leaf);
756 if (disk_bytenr > 0) {
757 inode_sub_bytes(inode, extent_end - start);
758 *hint_byte = disk_bytenr;
759 }
760 if (end == extent_end)
761 break;
762
763 path->slots[0]++;
764 goto next_slot;
765 }
766
767 /*
768 * | ---- range to drop ----- |
769 * | ------ extent ------ |
770 */
771 if (start <= key.offset && end >= extent_end) {
772 if (del_nr == 0) {
773 del_slot = path->slots[0];
774 del_nr = 1;
775 } else {
776 BUG_ON(del_slot + del_nr != path->slots[0]);
777 del_nr++;
778 }
779
780 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
781 inode_sub_bytes(inode,
782 extent_end - key.offset);
783 extent_end = ALIGN(extent_end,
784 root->sectorsize);
785 } else if (disk_bytenr > 0) {
786 ret = btrfs_free_extent(trans, root,
787 disk_bytenr, num_bytes, 0,
788 root->root_key.objectid,
789 key.objectid, key.offset -
790 extent_offset, 0);
791 BUG_ON(ret); /* -ENOMEM */
792 inode_sub_bytes(inode,
793 extent_end - key.offset);
794 *hint_byte = disk_bytenr;
795 }
796
797 if (end == extent_end)
798 break;
799
800 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
801 path->slots[0]++;
802 goto next_slot;
803 }
804
805 ret = btrfs_del_items(trans, root, path, del_slot,
806 del_nr);
807 if (ret) {
808 btrfs_abort_transaction(trans, root, ret);
809 goto out;
810 }
811
812 del_nr = 0;
813 del_slot = 0;
814
815 btrfs_release_path(path);
816 continue;
817 }
818
819 BUG_ON(1);
820 }
821
822 if (!ret && del_nr > 0) {
823 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
824 if (ret)
825 btrfs_abort_transaction(trans, root, ret);
826 }
827
828out:
829 btrfs_free_path(path);
830 return ret;
831}
832
833static int extent_mergeable(struct extent_buffer *leaf, int slot,
834 u64 objectid, u64 bytenr, u64 orig_offset,
835 u64 *start, u64 *end)
836{
837 struct btrfs_file_extent_item *fi;
838 struct btrfs_key key;
839 u64 extent_end;
840
841 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
842 return 0;
843
844 btrfs_item_key_to_cpu(leaf, &key, slot);
845 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
846 return 0;
847
848 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
849 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
850 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
851 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
852 btrfs_file_extent_compression(leaf, fi) ||
853 btrfs_file_extent_encryption(leaf, fi) ||
854 btrfs_file_extent_other_encoding(leaf, fi))
855 return 0;
856
857 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
858 if ((*start && *start != key.offset) || (*end && *end != extent_end))
859 return 0;
860
861 *start = key.offset;
862 *end = extent_end;
863 return 1;
864}
865
866/*
867 * Mark extent in the range start - end as written.
868 *
869 * This changes extent type from 'pre-allocated' to 'regular'. If only
870 * part of extent is marked as written, the extent will be split into
871 * two or three.
872 */
873int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
874 struct inode *inode, u64 start, u64 end)
875{
876 struct btrfs_root *root = BTRFS_I(inode)->root;
877 struct extent_buffer *leaf;
878 struct btrfs_path *path;
879 struct btrfs_file_extent_item *fi;
880 struct btrfs_key key;
881 struct btrfs_key new_key;
882 u64 bytenr;
883 u64 num_bytes;
884 u64 extent_end;
885 u64 orig_offset;
886 u64 other_start;
887 u64 other_end;
888 u64 split;
889 int del_nr = 0;
890 int del_slot = 0;
891 int recow;
892 int ret;
893 u64 ino = btrfs_ino(inode);
894
895 btrfs_drop_extent_cache(inode, start, end - 1, 0);
896
897 path = btrfs_alloc_path();
898 if (!path)
899 return -ENOMEM;
900again:
901 recow = 0;
902 split = start;
903 key.objectid = ino;
904 key.type = BTRFS_EXTENT_DATA_KEY;
905 key.offset = split;
906
907 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
908 if (ret < 0)
909 goto out;
910 if (ret > 0 && path->slots[0] > 0)
911 path->slots[0]--;
912
913 leaf = path->nodes[0];
914 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
915 BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY);
916 fi = btrfs_item_ptr(leaf, path->slots[0],
917 struct btrfs_file_extent_item);
918 BUG_ON(btrfs_file_extent_type(leaf, fi) !=
919 BTRFS_FILE_EXTENT_PREALLOC);
920 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
921 BUG_ON(key.offset > start || extent_end < end);
922
923 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
924 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
925 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
926 memcpy(&new_key, &key, sizeof(new_key));
927
928 if (start == key.offset && end < extent_end) {
929 other_start = 0;
930 other_end = start;
931 if (extent_mergeable(leaf, path->slots[0] - 1,
932 ino, bytenr, orig_offset,
933 &other_start, &other_end)) {
934 new_key.offset = end;
935 btrfs_set_item_key_safe(trans, root, path, &new_key);
936 fi = btrfs_item_ptr(leaf, path->slots[0],
937 struct btrfs_file_extent_item);
938 btrfs_set_file_extent_num_bytes(leaf, fi,
939 extent_end - end);
940 btrfs_set_file_extent_offset(leaf, fi,
941 end - orig_offset);
942 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
943 struct btrfs_file_extent_item);
944 btrfs_set_file_extent_num_bytes(leaf, fi,
945 end - other_start);
946 btrfs_mark_buffer_dirty(leaf);
947 goto out;
948 }
949 }
950
951 if (start > key.offset && end == extent_end) {
952 other_start = end;
953 other_end = 0;
954 if (extent_mergeable(leaf, path->slots[0] + 1,
955 ino, bytenr, orig_offset,
956 &other_start, &other_end)) {
957 fi = btrfs_item_ptr(leaf, path->slots[0],
958 struct btrfs_file_extent_item);
959 btrfs_set_file_extent_num_bytes(leaf, fi,
960 start - key.offset);
961 path->slots[0]++;
962 new_key.offset = start;
963 btrfs_set_item_key_safe(trans, root, path, &new_key);
964
965 fi = btrfs_item_ptr(leaf, path->slots[0],
966 struct btrfs_file_extent_item);
967 btrfs_set_file_extent_num_bytes(leaf, fi,
968 other_end - start);
969 btrfs_set_file_extent_offset(leaf, fi,
970 start - orig_offset);
971 btrfs_mark_buffer_dirty(leaf);
972 goto out;
973 }
974 }
975
976 while (start > key.offset || end < extent_end) {
977 if (key.offset == start)
978 split = end;
979
980 new_key.offset = split;
981 ret = btrfs_duplicate_item(trans, root, path, &new_key);
982 if (ret == -EAGAIN) {
983 btrfs_release_path(path);
984 goto again;
985 }
986 if (ret < 0) {
987 btrfs_abort_transaction(trans, root, ret);
988 goto out;
989 }
990
991 leaf = path->nodes[0];
992 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
993 struct btrfs_file_extent_item);
994 btrfs_set_file_extent_num_bytes(leaf, fi,
995 split - key.offset);
996
997 fi = btrfs_item_ptr(leaf, path->slots[0],
998 struct btrfs_file_extent_item);
999
1000 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1001 btrfs_set_file_extent_num_bytes(leaf, fi,
1002 extent_end - split);
1003 btrfs_mark_buffer_dirty(leaf);
1004
1005 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
1006 root->root_key.objectid,
1007 ino, orig_offset, 0);
1008 BUG_ON(ret); /* -ENOMEM */
1009
1010 if (split == start) {
1011 key.offset = start;
1012 } else {
1013 BUG_ON(start != key.offset);
1014 path->slots[0]--;
1015 extent_end = end;
1016 }
1017 recow = 1;
1018 }
1019
1020 other_start = end;
1021 other_end = 0;
1022 if (extent_mergeable(leaf, path->slots[0] + 1,
1023 ino, bytenr, orig_offset,
1024 &other_start, &other_end)) {
1025 if (recow) {
1026 btrfs_release_path(path);
1027 goto again;
1028 }
1029 extent_end = other_end;
1030 del_slot = path->slots[0] + 1;
1031 del_nr++;
1032 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1033 0, root->root_key.objectid,
1034 ino, orig_offset, 0);
1035 BUG_ON(ret); /* -ENOMEM */
1036 }
1037 other_start = 0;
1038 other_end = start;
1039 if (extent_mergeable(leaf, path->slots[0] - 1,
1040 ino, bytenr, orig_offset,
1041 &other_start, &other_end)) {
1042 if (recow) {
1043 btrfs_release_path(path);
1044 goto again;
1045 }
1046 key.offset = other_start;
1047 del_slot = path->slots[0];
1048 del_nr++;
1049 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1050 0, root->root_key.objectid,
1051 ino, orig_offset, 0);
1052 BUG_ON(ret); /* -ENOMEM */
1053 }
1054 if (del_nr == 0) {
1055 fi = btrfs_item_ptr(leaf, path->slots[0],
1056 struct btrfs_file_extent_item);
1057 btrfs_set_file_extent_type(leaf, fi,
1058 BTRFS_FILE_EXTENT_REG);
1059 btrfs_mark_buffer_dirty(leaf);
1060 } else {
1061 fi = btrfs_item_ptr(leaf, del_slot - 1,
1062 struct btrfs_file_extent_item);
1063 btrfs_set_file_extent_type(leaf, fi,
1064 BTRFS_FILE_EXTENT_REG);
1065 btrfs_set_file_extent_num_bytes(leaf, fi,
1066 extent_end - key.offset);
1067 btrfs_mark_buffer_dirty(leaf);
1068
1069 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1070 if (ret < 0) {
1071 btrfs_abort_transaction(trans, root, ret);
1072 goto out;
1073 }
1074 }
1075out:
1076 btrfs_free_path(path);
1077 return 0;
1078}
1079
1080/*
1081 * on error we return an unlocked page and the error value
1082 * on success we return a locked page and 0
1083 */
1084static int prepare_uptodate_page(struct page *page, u64 pos,
1085 bool force_uptodate)
1086{
1087 int ret = 0;
1088
1089 if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
1090 !PageUptodate(page)) {
1091 ret = btrfs_readpage(NULL, page);
1092 if (ret)
1093 return ret;
1094 lock_page(page);
1095 if (!PageUptodate(page)) {
1096 unlock_page(page);
1097 return -EIO;
1098 }
1099 }
1100 return 0;
1101}
1102
1103/*
1104 * this gets pages into the page cache and locks them down, it also properly
1105 * waits for data=ordered extents to finish before allowing the pages to be
1106 * modified.
1107 */
1108static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
1109 struct page **pages, size_t num_pages,
1110 loff_t pos, unsigned long first_index,
1111 size_t write_bytes, bool force_uptodate)
1112{
1113 struct extent_state *cached_state = NULL;
1114 int i;
1115 unsigned long index = pos >> PAGE_CACHE_SHIFT;
1116 struct inode *inode = fdentry(file)->d_inode;
1117 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1118 int err = 0;
1119 int faili = 0;
1120 u64 start_pos;
1121 u64 last_pos;
1122
1123 start_pos = pos & ~((u64)root->sectorsize - 1);
1124 last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
1125
1126again:
1127 for (i = 0; i < num_pages; i++) {
1128 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1129 mask | __GFP_WRITE);
1130 if (!pages[i]) {
1131 faili = i - 1;
1132 err = -ENOMEM;
1133 goto fail;
1134 }
1135
1136 if (i == 0)
1137 err = prepare_uptodate_page(pages[i], pos,
1138 force_uptodate);
1139 if (i == num_pages - 1)
1140 err = prepare_uptodate_page(pages[i],
1141 pos + write_bytes, false);
1142 if (err) {
1143 page_cache_release(pages[i]);
1144 faili = i - 1;
1145 goto fail;
1146 }
1147 wait_on_page_writeback(pages[i]);
1148 }
1149 err = 0;
1150 if (start_pos < inode->i_size) {
1151 struct btrfs_ordered_extent *ordered;
1152 lock_extent_bits(&BTRFS_I(inode)->io_tree,
1153 start_pos, last_pos - 1, 0, &cached_state);
1154 ordered = btrfs_lookup_first_ordered_extent(inode,
1155 last_pos - 1);
1156 if (ordered &&
1157 ordered->file_offset + ordered->len > start_pos &&
1158 ordered->file_offset < last_pos) {
1159 btrfs_put_ordered_extent(ordered);
1160 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1161 start_pos, last_pos - 1,
1162 &cached_state, GFP_NOFS);
1163 for (i = 0; i < num_pages; i++) {
1164 unlock_page(pages[i]);
1165 page_cache_release(pages[i]);
1166 }
1167 btrfs_wait_ordered_range(inode, start_pos,
1168 last_pos - start_pos);
1169 goto again;
1170 }
1171 if (ordered)
1172 btrfs_put_ordered_extent(ordered);
1173
1174 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
1175 last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1176 EXTENT_DO_ACCOUNTING, 0, 0, &cached_state,
1177 GFP_NOFS);
1178 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1179 start_pos, last_pos - 1, &cached_state,
1180 GFP_NOFS);
1181 }
1182 for (i = 0; i < num_pages; i++) {
1183 if (clear_page_dirty_for_io(pages[i]))
1184 account_page_redirty(pages[i]);
1185 set_page_extent_mapped(pages[i]);
1186 WARN_ON(!PageLocked(pages[i]));
1187 }
1188 return 0;
1189fail:
1190 while (faili >= 0) {
1191 unlock_page(pages[faili]);
1192 page_cache_release(pages[faili]);
1193 faili--;
1194 }
1195 return err;
1196
1197}
1198
1199static noinline ssize_t __btrfs_buffered_write(struct file *file,
1200 struct iov_iter *i,
1201 loff_t pos)
1202{
1203 struct inode *inode = fdentry(file)->d_inode;
1204 struct btrfs_root *root = BTRFS_I(inode)->root;
1205 struct page **pages = NULL;
1206 unsigned long first_index;
1207 size_t num_written = 0;
1208 int nrptrs;
1209 int ret = 0;
1210 bool force_page_uptodate = false;
1211
1212 nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
1213 PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
1214 (sizeof(struct page *)));
1215 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1216 nrptrs = max(nrptrs, 8);
1217 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
1218 if (!pages)
1219 return -ENOMEM;
1220
1221 first_index = pos >> PAGE_CACHE_SHIFT;
1222
1223 while (iov_iter_count(i) > 0) {
1224 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
1225 size_t write_bytes = min(iov_iter_count(i),
1226 nrptrs * (size_t)PAGE_CACHE_SIZE -
1227 offset);
1228 size_t num_pages = (write_bytes + offset +
1229 PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1230 size_t dirty_pages;
1231 size_t copied;
1232
1233 WARN_ON(num_pages > nrptrs);
1234
1235 /*
1236 * Fault pages before locking them in prepare_pages
1237 * to avoid recursive lock
1238 */
1239 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1240 ret = -EFAULT;
1241 break;
1242 }
1243
1244 ret = btrfs_delalloc_reserve_space(inode,
1245 num_pages << PAGE_CACHE_SHIFT);
1246 if (ret)
1247 break;
1248
1249 /*
1250 * This is going to setup the pages array with the number of
1251 * pages we want, so we don't really need to worry about the
1252 * contents of pages from loop to loop
1253 */
1254 ret = prepare_pages(root, file, pages, num_pages,
1255 pos, first_index, write_bytes,
1256 force_page_uptodate);
1257 if (ret) {
1258 btrfs_delalloc_release_space(inode,
1259 num_pages << PAGE_CACHE_SHIFT);
1260 break;
1261 }
1262
1263 copied = btrfs_copy_from_user(pos, num_pages,
1264 write_bytes, pages, i);
1265
1266 /*
1267 * if we have trouble faulting in the pages, fall
1268 * back to one page at a time
1269 */
1270 if (copied < write_bytes)
1271 nrptrs = 1;
1272
1273 if (copied == 0) {
1274 force_page_uptodate = true;
1275 dirty_pages = 0;
1276 } else {
1277 force_page_uptodate = false;
1278 dirty_pages = (copied + offset +
1279 PAGE_CACHE_SIZE - 1) >>
1280 PAGE_CACHE_SHIFT;
1281 }
1282
1283 /*
1284 * If we had a short copy we need to release the excess delaloc
1285 * bytes we reserved. We need to increment outstanding_extents
1286 * because btrfs_delalloc_release_space will decrement it, but
1287 * we still have an outstanding extent for the chunk we actually
1288 * managed to copy.
1289 */
1290 if (num_pages > dirty_pages) {
1291 if (copied > 0) {
1292 spin_lock(&BTRFS_I(inode)->lock);
1293 BTRFS_I(inode)->outstanding_extents++;
1294 spin_unlock(&BTRFS_I(inode)->lock);
1295 }
1296 btrfs_delalloc_release_space(inode,
1297 (num_pages - dirty_pages) <<
1298 PAGE_CACHE_SHIFT);
1299 }
1300
1301 if (copied > 0) {
1302 ret = btrfs_dirty_pages(root, inode, pages,
1303 dirty_pages, pos, copied,
1304 NULL);
1305 if (ret) {
1306 btrfs_delalloc_release_space(inode,
1307 dirty_pages << PAGE_CACHE_SHIFT);
1308 btrfs_drop_pages(pages, num_pages);
1309 break;
1310 }
1311 }
1312
1313 btrfs_drop_pages(pages, num_pages);
1314
1315 cond_resched();
1316
1317 balance_dirty_pages_ratelimited_nr(inode->i_mapping,
1318 dirty_pages);
1319 if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
1320 btrfs_btree_balance_dirty(root, 1);
1321
1322 pos += copied;
1323 num_written += copied;
1324 }
1325
1326 kfree(pages);
1327
1328 return num_written ? num_written : ret;
1329}
1330
1331static ssize_t __btrfs_direct_write(struct kiocb *iocb,
1332 const struct iovec *iov,
1333 unsigned long nr_segs, loff_t pos,
1334 loff_t *ppos, size_t count, size_t ocount)
1335{
1336 struct file *file = iocb->ki_filp;
1337 struct iov_iter i;
1338 ssize_t written;
1339 ssize_t written_buffered;
1340 loff_t endbyte;
1341 int err;
1342
1343 written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos,
1344 count, ocount);
1345
1346 if (written < 0 || written == count)
1347 return written;
1348
1349 pos += written;
1350 count -= written;
1351 iov_iter_init(&i, iov, nr_segs, count, written);
1352 written_buffered = __btrfs_buffered_write(file, &i, pos);
1353 if (written_buffered < 0) {
1354 err = written_buffered;
1355 goto out;
1356 }
1357 endbyte = pos + written_buffered - 1;
1358 err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
1359 if (err)
1360 goto out;
1361 written += written_buffered;
1362 *ppos = pos + written_buffered;
1363 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,
1364 endbyte >> PAGE_CACHE_SHIFT);
1365out:
1366 return written ? written : err;
1367}
1368
1369static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
1370 const struct iovec *iov,
1371 unsigned long nr_segs, loff_t pos)
1372{
1373 struct file *file = iocb->ki_filp;
1374 struct inode *inode = fdentry(file)->d_inode;
1375 struct btrfs_root *root = BTRFS_I(inode)->root;
1376 loff_t *ppos = &iocb->ki_pos;
1377 u64 start_pos;
1378 ssize_t num_written = 0;
1379 ssize_t err = 0;
1380 size_t count, ocount;
1381
1382 vfs_check_frozen(inode->i_sb, SB_FREEZE_WRITE);
1383
1384 mutex_lock(&inode->i_mutex);
1385
1386 err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
1387 if (err) {
1388 mutex_unlock(&inode->i_mutex);
1389 goto out;
1390 }
1391 count = ocount;
1392
1393 current->backing_dev_info = inode->i_mapping->backing_dev_info;
1394 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1395 if (err) {
1396 mutex_unlock(&inode->i_mutex);
1397 goto out;
1398 }
1399
1400 if (count == 0) {
1401 mutex_unlock(&inode->i_mutex);
1402 goto out;
1403 }
1404
1405 err = file_remove_suid(file);
1406 if (err) {
1407 mutex_unlock(&inode->i_mutex);
1408 goto out;
1409 }
1410
1411 /*
1412 * If BTRFS flips readonly due to some impossible error
1413 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1414 * although we have opened a file as writable, we have
1415 * to stop this write operation to ensure FS consistency.
1416 */
1417 if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
1418 mutex_unlock(&inode->i_mutex);
1419 err = -EROFS;
1420 goto out;
1421 }
1422
1423 err = file_update_time(file);
1424 if (err) {
1425 mutex_unlock(&inode->i_mutex);
1426 goto out;
1427 }
1428
1429 start_pos = round_down(pos, root->sectorsize);
1430 if (start_pos > i_size_read(inode)) {
1431 err = btrfs_cont_expand(inode, i_size_read(inode), start_pos);
1432 if (err) {
1433 mutex_unlock(&inode->i_mutex);
1434 goto out;
1435 }
1436 }
1437
1438 if (unlikely(file->f_flags & O_DIRECT)) {
1439 num_written = __btrfs_direct_write(iocb, iov, nr_segs,
1440 pos, ppos, count, ocount);
1441 } else {
1442 struct iov_iter i;
1443
1444 iov_iter_init(&i, iov, nr_segs, count, num_written);
1445
1446 num_written = __btrfs_buffered_write(file, &i, pos);
1447 if (num_written > 0)
1448 *ppos = pos + num_written;
1449 }
1450
1451 mutex_unlock(&inode->i_mutex);
1452
1453 /*
1454 * we want to make sure fsync finds this change
1455 * but we haven't joined a transaction running right now.
1456 *
1457 * Later on, someone is sure to update the inode and get the
1458 * real transid recorded.
1459 *
1460 * We set last_trans now to the fs_info generation + 1,
1461 * this will either be one more than the running transaction
1462 * or the generation used for the next transaction if there isn't
1463 * one running right now.
1464 */
1465 BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
1466 if (num_written > 0 || num_written == -EIOCBQUEUED) {
1467 err = generic_write_sync(file, pos, num_written);
1468 if (err < 0 && num_written > 0)
1469 num_written = err;
1470 }
1471out:
1472 current->backing_dev_info = NULL;
1473 return num_written ? num_written : err;
1474}
1475
1476int btrfs_release_file(struct inode *inode, struct file *filp)
1477{
1478 /*
1479 * ordered_data_close is set by settattr when we are about to truncate
1480 * a file from a non-zero size to a zero size. This tries to
1481 * flush down new bytes that may have been written if the
1482 * application were using truncate to replace a file in place.
1483 */
1484 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
1485 &BTRFS_I(inode)->runtime_flags)) {
1486 btrfs_add_ordered_operation(NULL, BTRFS_I(inode)->root, inode);
1487 if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
1488 filemap_flush(inode->i_mapping);
1489 }
1490 if (filp->private_data)
1491 btrfs_ioctl_trans_end(filp);
1492 return 0;
1493}
1494
1495/*
1496 * fsync call for both files and directories. This logs the inode into
1497 * the tree log instead of forcing full commits whenever possible.
1498 *
1499 * It needs to call filemap_fdatawait so that all ordered extent updates are
1500 * in the metadata btree are up to date for copying to the log.
1501 *
1502 * It drops the inode mutex before doing the tree log commit. This is an
1503 * important optimization for directories because holding the mutex prevents
1504 * new operations on the dir while we write to disk.
1505 */
1506int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
1507{
1508 struct dentry *dentry = file->f_path.dentry;
1509 struct inode *inode = dentry->d_inode;
1510 struct btrfs_root *root = BTRFS_I(inode)->root;
1511 int ret = 0;
1512 struct btrfs_trans_handle *trans;
1513
1514 trace_btrfs_sync_file(file, datasync);
1515
1516 mutex_lock(&inode->i_mutex);
1517
1518 /*
1519 * we wait first, since the writeback may change the inode, also wait
1520 * ordered range does a filemape_write_and_wait_range which is why we
1521 * don't do it above like other file systems.
1522 */
1523 root->log_batch++;
1524 btrfs_wait_ordered_range(inode, start, end);
1525 root->log_batch++;
1526
1527 /*
1528 * check the transaction that last modified this inode
1529 * and see if its already been committed
1530 */
1531 if (!BTRFS_I(inode)->last_trans) {
1532 mutex_unlock(&inode->i_mutex);
1533 goto out;
1534 }
1535
1536 /*
1537 * if the last transaction that changed this file was before
1538 * the current transaction, we can bail out now without any
1539 * syncing
1540 */
1541 smp_mb();
1542 if (btrfs_inode_in_log(inode, root->fs_info->generation) ||
1543 BTRFS_I(inode)->last_trans <=
1544 root->fs_info->last_trans_committed) {
1545 BTRFS_I(inode)->last_trans = 0;
1546 mutex_unlock(&inode->i_mutex);
1547 goto out;
1548 }
1549
1550 /*
1551 * ok we haven't committed the transaction yet, lets do a commit
1552 */
1553 if (file->private_data)
1554 btrfs_ioctl_trans_end(file);
1555
1556 trans = btrfs_start_transaction(root, 0);
1557 if (IS_ERR(trans)) {
1558 ret = PTR_ERR(trans);
1559 mutex_unlock(&inode->i_mutex);
1560 goto out;
1561 }
1562
1563 ret = btrfs_log_dentry_safe(trans, root, dentry);
1564 if (ret < 0) {
1565 mutex_unlock(&inode->i_mutex);
1566 goto out;
1567 }
1568
1569 /* we've logged all the items and now have a consistent
1570 * version of the file in the log. It is possible that
1571 * someone will come in and modify the file, but that's
1572 * fine because the log is consistent on disk, and we
1573 * have references to all of the file's extents
1574 *
1575 * It is possible that someone will come in and log the
1576 * file again, but that will end up using the synchronization
1577 * inside btrfs_sync_log to keep things safe.
1578 */
1579 mutex_unlock(&inode->i_mutex);
1580
1581 if (ret != BTRFS_NO_LOG_SYNC) {
1582 if (ret > 0) {
1583 ret = btrfs_commit_transaction(trans, root);
1584 } else {
1585 ret = btrfs_sync_log(trans, root);
1586 if (ret == 0)
1587 ret = btrfs_end_transaction(trans, root);
1588 else
1589 ret = btrfs_commit_transaction(trans, root);
1590 }
1591 } else {
1592 ret = btrfs_end_transaction(trans, root);
1593 }
1594out:
1595 return ret > 0 ? -EIO : ret;
1596}
1597
1598static const struct vm_operations_struct btrfs_file_vm_ops = {
1599 .fault = filemap_fault,
1600 .page_mkwrite = btrfs_page_mkwrite,
1601};
1602
1603static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
1604{
1605 struct address_space *mapping = filp->f_mapping;
1606
1607 if (!mapping->a_ops->readpage)
1608 return -ENOEXEC;
1609
1610 file_accessed(filp);
1611 vma->vm_ops = &btrfs_file_vm_ops;
1612 vma->vm_flags |= VM_CAN_NONLINEAR;
1613
1614 return 0;
1615}
1616
1617static long btrfs_fallocate(struct file *file, int mode,
1618 loff_t offset, loff_t len)
1619{
1620 struct inode *inode = file->f_path.dentry->d_inode;
1621 struct extent_state *cached_state = NULL;
1622 u64 cur_offset;
1623 u64 last_byte;
1624 u64 alloc_start;
1625 u64 alloc_end;
1626 u64 alloc_hint = 0;
1627 u64 locked_end;
1628 u64 mask = BTRFS_I(inode)->root->sectorsize - 1;
1629 struct extent_map *em;
1630 int ret;
1631
1632 alloc_start = offset & ~mask;
1633 alloc_end = (offset + len + mask) & ~mask;
1634
1635 /* We only support the FALLOC_FL_KEEP_SIZE mode */
1636 if (mode & ~FALLOC_FL_KEEP_SIZE)
1637 return -EOPNOTSUPP;
1638
1639 /*
1640 * Make sure we have enough space before we do the
1641 * allocation.
1642 */
1643 ret = btrfs_check_data_free_space(inode, len);
1644 if (ret)
1645 return ret;
1646
1647 /*
1648 * wait for ordered IO before we have any locks. We'll loop again
1649 * below with the locks held.
1650 */
1651 btrfs_wait_ordered_range(inode, alloc_start, alloc_end - alloc_start);
1652
1653 mutex_lock(&inode->i_mutex);
1654 ret = inode_newsize_ok(inode, alloc_end);
1655 if (ret)
1656 goto out;
1657
1658 if (alloc_start > inode->i_size) {
1659 ret = btrfs_cont_expand(inode, i_size_read(inode),
1660 alloc_start);
1661 if (ret)
1662 goto out;
1663 }
1664
1665 locked_end = alloc_end - 1;
1666 while (1) {
1667 struct btrfs_ordered_extent *ordered;
1668
1669 /* the extent lock is ordered inside the running
1670 * transaction
1671 */
1672 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
1673 locked_end, 0, &cached_state);
1674 ordered = btrfs_lookup_first_ordered_extent(inode,
1675 alloc_end - 1);
1676 if (ordered &&
1677 ordered->file_offset + ordered->len > alloc_start &&
1678 ordered->file_offset < alloc_end) {
1679 btrfs_put_ordered_extent(ordered);
1680 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1681 alloc_start, locked_end,
1682 &cached_state, GFP_NOFS);
1683 /*
1684 * we can't wait on the range with the transaction
1685 * running or with the extent lock held
1686 */
1687 btrfs_wait_ordered_range(inode, alloc_start,
1688 alloc_end - alloc_start);
1689 } else {
1690 if (ordered)
1691 btrfs_put_ordered_extent(ordered);
1692 break;
1693 }
1694 }
1695
1696 cur_offset = alloc_start;
1697 while (1) {
1698 u64 actual_end;
1699
1700 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
1701 alloc_end - cur_offset, 0);
1702 if (IS_ERR_OR_NULL(em)) {
1703 if (!em)
1704 ret = -ENOMEM;
1705 else
1706 ret = PTR_ERR(em);
1707 break;
1708 }
1709 last_byte = min(extent_map_end(em), alloc_end);
1710 actual_end = min_t(u64, extent_map_end(em), offset + len);
1711 last_byte = (last_byte + mask) & ~mask;
1712
1713 if (em->block_start == EXTENT_MAP_HOLE ||
1714 (cur_offset >= inode->i_size &&
1715 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
1716 ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
1717 last_byte - cur_offset,
1718 1 << inode->i_blkbits,
1719 offset + len,
1720 &alloc_hint);
1721
1722 if (ret < 0) {
1723 free_extent_map(em);
1724 break;
1725 }
1726 } else if (actual_end > inode->i_size &&
1727 !(mode & FALLOC_FL_KEEP_SIZE)) {
1728 /*
1729 * We didn't need to allocate any more space, but we
1730 * still extended the size of the file so we need to
1731 * update i_size.
1732 */
1733 inode->i_ctime = CURRENT_TIME;
1734 i_size_write(inode, actual_end);
1735 btrfs_ordered_update_i_size(inode, actual_end, NULL);
1736 }
1737 free_extent_map(em);
1738
1739 cur_offset = last_byte;
1740 if (cur_offset >= alloc_end) {
1741 ret = 0;
1742 break;
1743 }
1744 }
1745 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
1746 &cached_state, GFP_NOFS);
1747out:
1748 mutex_unlock(&inode->i_mutex);
1749 /* Let go of our reservation. */
1750 btrfs_free_reserved_data_space(inode, len);
1751 return ret;
1752}
1753
1754static int find_desired_extent(struct inode *inode, loff_t *offset, int origin)
1755{
1756 struct btrfs_root *root = BTRFS_I(inode)->root;
1757 struct extent_map *em;
1758 struct extent_state *cached_state = NULL;
1759 u64 lockstart = *offset;
1760 u64 lockend = i_size_read(inode);
1761 u64 start = *offset;
1762 u64 orig_start = *offset;
1763 u64 len = i_size_read(inode);
1764 u64 last_end = 0;
1765 int ret = 0;
1766
1767 lockend = max_t(u64, root->sectorsize, lockend);
1768 if (lockend <= lockstart)
1769 lockend = lockstart + root->sectorsize;
1770
1771 len = lockend - lockstart + 1;
1772
1773 len = max_t(u64, len, root->sectorsize);
1774 if (inode->i_size == 0)
1775 return -ENXIO;
1776
1777 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0,
1778 &cached_state);
1779
1780 /*
1781 * Delalloc is such a pain. If we have a hole and we have pending
1782 * delalloc for a portion of the hole we will get back a hole that
1783 * exists for the entire range since it hasn't been actually written
1784 * yet. So to take care of this case we need to look for an extent just
1785 * before the position we want in case there is outstanding delalloc
1786 * going on here.
1787 */
1788 if (origin == SEEK_HOLE && start != 0) {
1789 if (start <= root->sectorsize)
1790 em = btrfs_get_extent_fiemap(inode, NULL, 0, 0,
1791 root->sectorsize, 0);
1792 else
1793 em = btrfs_get_extent_fiemap(inode, NULL, 0,
1794 start - root->sectorsize,
1795 root->sectorsize, 0);
1796 if (IS_ERR(em)) {
1797 ret = PTR_ERR(em);
1798 goto out;
1799 }
1800 last_end = em->start + em->len;
1801 if (em->block_start == EXTENT_MAP_DELALLOC)
1802 last_end = min_t(u64, last_end, inode->i_size);
1803 free_extent_map(em);
1804 }
1805
1806 while (1) {
1807 em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
1808 if (IS_ERR(em)) {
1809 ret = PTR_ERR(em);
1810 break;
1811 }
1812
1813 if (em->block_start == EXTENT_MAP_HOLE) {
1814 if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
1815 if (last_end <= orig_start) {
1816 free_extent_map(em);
1817 ret = -ENXIO;
1818 break;
1819 }
1820 }
1821
1822 if (origin == SEEK_HOLE) {
1823 *offset = start;
1824 free_extent_map(em);
1825 break;
1826 }
1827 } else {
1828 if (origin == SEEK_DATA) {
1829 if (em->block_start == EXTENT_MAP_DELALLOC) {
1830 if (start >= inode->i_size) {
1831 free_extent_map(em);
1832 ret = -ENXIO;
1833 break;
1834 }
1835 }
1836
1837 *offset = start;
1838 free_extent_map(em);
1839 break;
1840 }
1841 }
1842
1843 start = em->start + em->len;
1844 last_end = em->start + em->len;
1845
1846 if (em->block_start == EXTENT_MAP_DELALLOC)
1847 last_end = min_t(u64, last_end, inode->i_size);
1848
1849 if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
1850 free_extent_map(em);
1851 ret = -ENXIO;
1852 break;
1853 }
1854 free_extent_map(em);
1855 cond_resched();
1856 }
1857 if (!ret)
1858 *offset = min(*offset, inode->i_size);
1859out:
1860 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
1861 &cached_state, GFP_NOFS);
1862 return ret;
1863}
1864
1865static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int origin)
1866{
1867 struct inode *inode = file->f_mapping->host;
1868 int ret;
1869
1870 mutex_lock(&inode->i_mutex);
1871 switch (origin) {
1872 case SEEK_END:
1873 case SEEK_CUR:
1874 offset = generic_file_llseek(file, offset, origin);
1875 goto out;
1876 case SEEK_DATA:
1877 case SEEK_HOLE:
1878 if (offset >= i_size_read(inode)) {
1879 mutex_unlock(&inode->i_mutex);
1880 return -ENXIO;
1881 }
1882
1883 ret = find_desired_extent(inode, &offset, origin);
1884 if (ret) {
1885 mutex_unlock(&inode->i_mutex);
1886 return ret;
1887 }
1888 }
1889
1890 if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
1891 offset = -EINVAL;
1892 goto out;
1893 }
1894 if (offset > inode->i_sb->s_maxbytes) {
1895 offset = -EINVAL;
1896 goto out;
1897 }
1898
1899 /* Special lock needed here? */
1900 if (offset != file->f_pos) {
1901 file->f_pos = offset;
1902 file->f_version = 0;
1903 }
1904out:
1905 mutex_unlock(&inode->i_mutex);
1906 return offset;
1907}
1908
1909const struct file_operations btrfs_file_operations = {
1910 .llseek = btrfs_file_llseek,
1911 .read = do_sync_read,
1912 .write = do_sync_write,
1913 .aio_read = generic_file_aio_read,
1914 .splice_read = generic_file_splice_read,
1915 .aio_write = btrfs_file_aio_write,
1916 .mmap = btrfs_file_mmap,
1917 .open = generic_file_open,
1918 .release = btrfs_release_file,
1919 .fsync = btrfs_sync_file,
1920 .fallocate = btrfs_fallocate,
1921 .unlocked_ioctl = btrfs_ioctl,
1922#ifdef CONFIG_COMPAT
1923 .compat_ioctl = btrfs_ioctl,
1924#endif
1925};