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Merge tag 'cleanup-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / fs / btrfs / file.c
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 <linux/btrfs.h>
34 #include "ctree.h"
35 #include "disk-io.h"
36 #include "transaction.h"
37 #include "btrfs_inode.h"
38 #include "print-tree.h"
39 #include "tree-log.h"
40 #include "locking.h"
41 #include "compat.h"
42 #include "volumes.h"
43
44 static 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 */
50 struct 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
70 static 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 */
94 static 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
131 static 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 */
146 int 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 */
195 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;
214 out:
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 */
222 static struct inode_defrag *
223 btrfs_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 }
256 out:
257 if (entry)
258 rb_erase(parent, &fs_info->defrag_inodes);
259 spin_unlock(&fs_info->defrag_inodes_lock);
260 return entry;
261 }
262
263 void 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
288 static 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 if (btrfs_root_refs(&inode_root->root_item) == 0) {
312 ret = -ENOENT;
313 goto cleanup;
314 }
315
316 key.objectid = defrag->ino;
317 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
318 key.offset = 0;
319 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
320 if (IS_ERR(inode)) {
321 ret = PTR_ERR(inode);
322 goto cleanup;
323 }
324 srcu_read_unlock(&fs_info->subvol_srcu, index);
325
326 /* do a chunk of defrag */
327 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
328 memset(&range, 0, sizeof(range));
329 range.len = (u64)-1;
330 range.start = defrag->last_offset;
331
332 sb_start_write(fs_info->sb);
333 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
334 BTRFS_DEFRAG_BATCH);
335 sb_end_write(fs_info->sb);
336 /*
337 * if we filled the whole defrag batch, there
338 * must be more work to do. Queue this defrag
339 * again
340 */
341 if (num_defrag == BTRFS_DEFRAG_BATCH) {
342 defrag->last_offset = range.start;
343 btrfs_requeue_inode_defrag(inode, defrag);
344 } else if (defrag->last_offset && !defrag->cycled) {
345 /*
346 * we didn't fill our defrag batch, but
347 * we didn't start at zero. Make sure we loop
348 * around to the start of the file.
349 */
350 defrag->last_offset = 0;
351 defrag->cycled = 1;
352 btrfs_requeue_inode_defrag(inode, defrag);
353 } else {
354 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
355 }
356
357 iput(inode);
358 return 0;
359 cleanup:
360 srcu_read_unlock(&fs_info->subvol_srcu, index);
361 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
362 return ret;
363 }
364
365 /*
366 * run through the list of inodes in the FS that need
367 * defragging
368 */
369 int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
370 {
371 struct inode_defrag *defrag;
372 u64 first_ino = 0;
373 u64 root_objectid = 0;
374
375 atomic_inc(&fs_info->defrag_running);
376 while(1) {
377 /* Pause the auto defragger. */
378 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
379 &fs_info->fs_state))
380 break;
381
382 if (!__need_auto_defrag(fs_info->tree_root))
383 break;
384
385 /* find an inode to defrag */
386 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
387 first_ino);
388 if (!defrag) {
389 if (root_objectid || first_ino) {
390 root_objectid = 0;
391 first_ino = 0;
392 continue;
393 } else {
394 break;
395 }
396 }
397
398 first_ino = defrag->ino + 1;
399 root_objectid = defrag->root;
400
401 __btrfs_run_defrag_inode(fs_info, defrag);
402 }
403 atomic_dec(&fs_info->defrag_running);
404
405 /*
406 * during unmount, we use the transaction_wait queue to
407 * wait for the defragger to stop
408 */
409 wake_up(&fs_info->transaction_wait);
410 return 0;
411 }
412
413 /* simple helper to fault in pages and copy. This should go away
414 * and be replaced with calls into generic code.
415 */
416 static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
417 size_t write_bytes,
418 struct page **prepared_pages,
419 struct iov_iter *i)
420 {
421 size_t copied = 0;
422 size_t total_copied = 0;
423 int pg = 0;
424 int offset = pos & (PAGE_CACHE_SIZE - 1);
425
426 while (write_bytes > 0) {
427 size_t count = min_t(size_t,
428 PAGE_CACHE_SIZE - offset, write_bytes);
429 struct page *page = prepared_pages[pg];
430 /*
431 * Copy data from userspace to the current page
432 *
433 * Disable pagefault to avoid recursive lock since
434 * the pages are already locked
435 */
436 pagefault_disable();
437 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
438 pagefault_enable();
439
440 /* Flush processor's dcache for this page */
441 flush_dcache_page(page);
442
443 /*
444 * if we get a partial write, we can end up with
445 * partially up to date pages. These add
446 * a lot of complexity, so make sure they don't
447 * happen by forcing this copy to be retried.
448 *
449 * The rest of the btrfs_file_write code will fall
450 * back to page at a time copies after we return 0.
451 */
452 if (!PageUptodate(page) && copied < count)
453 copied = 0;
454
455 iov_iter_advance(i, copied);
456 write_bytes -= copied;
457 total_copied += copied;
458
459 /* Return to btrfs_file_aio_write to fault page */
460 if (unlikely(copied == 0))
461 break;
462
463 if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
464 offset += copied;
465 } else {
466 pg++;
467 offset = 0;
468 }
469 }
470 return total_copied;
471 }
472
473 /*
474 * unlocks pages after btrfs_file_write is done with them
475 */
476 void btrfs_drop_pages(struct page **pages, size_t num_pages)
477 {
478 size_t i;
479 for (i = 0; i < num_pages; i++) {
480 /* page checked is some magic around finding pages that
481 * have been modified without going through btrfs_set_page_dirty
482 * clear it here
483 */
484 ClearPageChecked(pages[i]);
485 unlock_page(pages[i]);
486 mark_page_accessed(pages[i]);
487 page_cache_release(pages[i]);
488 }
489 }
490
491 /*
492 * after copy_from_user, pages need to be dirtied and we need to make
493 * sure holes are created between the current EOF and the start of
494 * any next extents (if required).
495 *
496 * this also makes the decision about creating an inline extent vs
497 * doing real data extents, marking pages dirty and delalloc as required.
498 */
499 int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode,
500 struct page **pages, size_t num_pages,
501 loff_t pos, size_t write_bytes,
502 struct extent_state **cached)
503 {
504 int err = 0;
505 int i;
506 u64 num_bytes;
507 u64 start_pos;
508 u64 end_of_last_block;
509 u64 end_pos = pos + write_bytes;
510 loff_t isize = i_size_read(inode);
511
512 start_pos = pos & ~((u64)root->sectorsize - 1);
513 num_bytes = ALIGN(write_bytes + pos - start_pos, root->sectorsize);
514
515 end_of_last_block = start_pos + num_bytes - 1;
516 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
517 cached);
518 if (err)
519 return err;
520
521 for (i = 0; i < num_pages; i++) {
522 struct page *p = pages[i];
523 SetPageUptodate(p);
524 ClearPageChecked(p);
525 set_page_dirty(p);
526 }
527
528 /*
529 * we've only changed i_size in ram, and we haven't updated
530 * the disk i_size. There is no need to log the inode
531 * at this time.
532 */
533 if (end_pos > isize)
534 i_size_write(inode, end_pos);
535 return 0;
536 }
537
538 /*
539 * this drops all the extents in the cache that intersect the range
540 * [start, end]. Existing extents are split as required.
541 */
542 void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
543 int skip_pinned)
544 {
545 struct extent_map *em;
546 struct extent_map *split = NULL;
547 struct extent_map *split2 = NULL;
548 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
549 u64 len = end - start + 1;
550 u64 gen;
551 int ret;
552 int testend = 1;
553 unsigned long flags;
554 int compressed = 0;
555
556 WARN_ON(end < start);
557 if (end == (u64)-1) {
558 len = (u64)-1;
559 testend = 0;
560 }
561 while (1) {
562 int no_splits = 0;
563
564 if (!split)
565 split = alloc_extent_map();
566 if (!split2)
567 split2 = alloc_extent_map();
568 if (!split || !split2)
569 no_splits = 1;
570
571 write_lock(&em_tree->lock);
572 em = lookup_extent_mapping(em_tree, start, len);
573 if (!em) {
574 write_unlock(&em_tree->lock);
575 break;
576 }
577 flags = em->flags;
578 gen = em->generation;
579 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
580 if (testend && em->start + em->len >= start + len) {
581 free_extent_map(em);
582 write_unlock(&em_tree->lock);
583 break;
584 }
585 start = em->start + em->len;
586 if (testend)
587 len = start + len - (em->start + em->len);
588 free_extent_map(em);
589 write_unlock(&em_tree->lock);
590 continue;
591 }
592 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
593 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
594 clear_bit(EXTENT_FLAG_LOGGING, &flags);
595 remove_extent_mapping(em_tree, em);
596 if (no_splits)
597 goto next;
598
599 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
600 em->start < start) {
601 split->start = em->start;
602 split->len = start - em->start;
603 split->orig_start = em->orig_start;
604 split->block_start = em->block_start;
605
606 if (compressed)
607 split->block_len = em->block_len;
608 else
609 split->block_len = split->len;
610 split->orig_block_len = max(split->block_len,
611 em->orig_block_len);
612 split->generation = gen;
613 split->bdev = em->bdev;
614 split->flags = flags;
615 split->compress_type = em->compress_type;
616 ret = add_extent_mapping(em_tree, split);
617 BUG_ON(ret); /* Logic error */
618 list_move(&split->list, &em_tree->modified_extents);
619 free_extent_map(split);
620 split = split2;
621 split2 = NULL;
622 }
623 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
624 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 split->orig_block_len = max(em->block_len,
634 em->orig_block_len);
635
636 if (compressed) {
637 split->block_len = em->block_len;
638 split->block_start = em->block_start;
639 split->orig_start = em->orig_start;
640 } else {
641 split->block_len = split->len;
642 split->block_start = em->block_start + diff;
643 split->orig_start = em->orig_start;
644 }
645
646 ret = add_extent_mapping(em_tree, split);
647 BUG_ON(ret); /* Logic error */
648 list_move(&split->list, &em_tree->modified_extents);
649 free_extent_map(split);
650 split = NULL;
651 }
652 next:
653 write_unlock(&em_tree->lock);
654
655 /* once for us */
656 free_extent_map(em);
657 /* once for the tree*/
658 free_extent_map(em);
659 }
660 if (split)
661 free_extent_map(split);
662 if (split2)
663 free_extent_map(split2);
664 }
665
666 /*
667 * this is very complex, but the basic idea is to drop all extents
668 * in the range start - end. hint_block is filled in with a block number
669 * that would be a good hint to the block allocator for this file.
670 *
671 * If an extent intersects the range but is not entirely inside the range
672 * it is either truncated or split. Anything entirely inside the range
673 * is deleted from the tree.
674 */
675 int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
676 struct btrfs_root *root, struct inode *inode,
677 struct btrfs_path *path, u64 start, u64 end,
678 u64 *drop_end, int drop_cache)
679 {
680 struct extent_buffer *leaf;
681 struct btrfs_file_extent_item *fi;
682 struct btrfs_key key;
683 struct btrfs_key new_key;
684 u64 ino = btrfs_ino(inode);
685 u64 search_start = start;
686 u64 disk_bytenr = 0;
687 u64 num_bytes = 0;
688 u64 extent_offset = 0;
689 u64 extent_end = 0;
690 int del_nr = 0;
691 int del_slot = 0;
692 int extent_type;
693 int recow;
694 int ret;
695 int modify_tree = -1;
696 int update_refs = (root->ref_cows || root == root->fs_info->tree_root);
697 int found = 0;
698
699 if (drop_cache)
700 btrfs_drop_extent_cache(inode, start, end - 1, 0);
701
702 if (start >= BTRFS_I(inode)->disk_i_size)
703 modify_tree = 0;
704
705 while (1) {
706 recow = 0;
707 ret = btrfs_lookup_file_extent(trans, root, path, ino,
708 search_start, modify_tree);
709 if (ret < 0)
710 break;
711 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
712 leaf = path->nodes[0];
713 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
714 if (key.objectid == ino &&
715 key.type == BTRFS_EXTENT_DATA_KEY)
716 path->slots[0]--;
717 }
718 ret = 0;
719 next_slot:
720 leaf = path->nodes[0];
721 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
722 BUG_ON(del_nr > 0);
723 ret = btrfs_next_leaf(root, path);
724 if (ret < 0)
725 break;
726 if (ret > 0) {
727 ret = 0;
728 break;
729 }
730 leaf = path->nodes[0];
731 recow = 1;
732 }
733
734 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
735 if (key.objectid > ino ||
736 key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
737 break;
738
739 fi = btrfs_item_ptr(leaf, path->slots[0],
740 struct btrfs_file_extent_item);
741 extent_type = btrfs_file_extent_type(leaf, fi);
742
743 if (extent_type == BTRFS_FILE_EXTENT_REG ||
744 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
745 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
746 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
747 extent_offset = btrfs_file_extent_offset(leaf, fi);
748 extent_end = key.offset +
749 btrfs_file_extent_num_bytes(leaf, fi);
750 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
751 extent_end = key.offset +
752 btrfs_file_extent_inline_len(leaf, fi);
753 } else {
754 WARN_ON(1);
755 extent_end = search_start;
756 }
757
758 if (extent_end <= search_start) {
759 path->slots[0]++;
760 goto next_slot;
761 }
762
763 found = 1;
764 search_start = max(key.offset, start);
765 if (recow || !modify_tree) {
766 modify_tree = -1;
767 btrfs_release_path(path);
768 continue;
769 }
770
771 /*
772 * | - range to drop - |
773 * | -------- extent -------- |
774 */
775 if (start > key.offset && end < extent_end) {
776 BUG_ON(del_nr > 0);
777 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
778
779 memcpy(&new_key, &key, sizeof(new_key));
780 new_key.offset = start;
781 ret = btrfs_duplicate_item(trans, root, path,
782 &new_key);
783 if (ret == -EAGAIN) {
784 btrfs_release_path(path);
785 continue;
786 }
787 if (ret < 0)
788 break;
789
790 leaf = path->nodes[0];
791 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
792 struct btrfs_file_extent_item);
793 btrfs_set_file_extent_num_bytes(leaf, fi,
794 start - key.offset);
795
796 fi = btrfs_item_ptr(leaf, path->slots[0],
797 struct btrfs_file_extent_item);
798
799 extent_offset += start - key.offset;
800 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
801 btrfs_set_file_extent_num_bytes(leaf, fi,
802 extent_end - start);
803 btrfs_mark_buffer_dirty(leaf);
804
805 if (update_refs && disk_bytenr > 0) {
806 ret = btrfs_inc_extent_ref(trans, root,
807 disk_bytenr, num_bytes, 0,
808 root->root_key.objectid,
809 new_key.objectid,
810 start - extent_offset, 0);
811 BUG_ON(ret); /* -ENOMEM */
812 }
813 key.offset = start;
814 }
815 /*
816 * | ---- range to drop ----- |
817 * | -------- extent -------- |
818 */
819 if (start <= key.offset && end < extent_end) {
820 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
821
822 memcpy(&new_key, &key, sizeof(new_key));
823 new_key.offset = end;
824 btrfs_set_item_key_safe(trans, root, path, &new_key);
825
826 extent_offset += end - key.offset;
827 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
828 btrfs_set_file_extent_num_bytes(leaf, fi,
829 extent_end - end);
830 btrfs_mark_buffer_dirty(leaf);
831 if (update_refs && disk_bytenr > 0)
832 inode_sub_bytes(inode, end - key.offset);
833 break;
834 }
835
836 search_start = extent_end;
837 /*
838 * | ---- range to drop ----- |
839 * | -------- extent -------- |
840 */
841 if (start > key.offset && end >= extent_end) {
842 BUG_ON(del_nr > 0);
843 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
844
845 btrfs_set_file_extent_num_bytes(leaf, fi,
846 start - key.offset);
847 btrfs_mark_buffer_dirty(leaf);
848 if (update_refs && disk_bytenr > 0)
849 inode_sub_bytes(inode, extent_end - start);
850 if (end == extent_end)
851 break;
852
853 path->slots[0]++;
854 goto next_slot;
855 }
856
857 /*
858 * | ---- range to drop ----- |
859 * | ------ extent ------ |
860 */
861 if (start <= key.offset && end >= extent_end) {
862 if (del_nr == 0) {
863 del_slot = path->slots[0];
864 del_nr = 1;
865 } else {
866 BUG_ON(del_slot + del_nr != path->slots[0]);
867 del_nr++;
868 }
869
870 if (update_refs &&
871 extent_type == BTRFS_FILE_EXTENT_INLINE) {
872 inode_sub_bytes(inode,
873 extent_end - key.offset);
874 extent_end = ALIGN(extent_end,
875 root->sectorsize);
876 } else if (update_refs && disk_bytenr > 0) {
877 ret = btrfs_free_extent(trans, root,
878 disk_bytenr, num_bytes, 0,
879 root->root_key.objectid,
880 key.objectid, key.offset -
881 extent_offset, 0);
882 BUG_ON(ret); /* -ENOMEM */
883 inode_sub_bytes(inode,
884 extent_end - key.offset);
885 }
886
887 if (end == extent_end)
888 break;
889
890 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
891 path->slots[0]++;
892 goto next_slot;
893 }
894
895 ret = btrfs_del_items(trans, root, path, del_slot,
896 del_nr);
897 if (ret) {
898 btrfs_abort_transaction(trans, root, ret);
899 break;
900 }
901
902 del_nr = 0;
903 del_slot = 0;
904
905 btrfs_release_path(path);
906 continue;
907 }
908
909 BUG_ON(1);
910 }
911
912 if (!ret && del_nr > 0) {
913 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
914 if (ret)
915 btrfs_abort_transaction(trans, root, ret);
916 }
917
918 if (drop_end)
919 *drop_end = found ? min(end, extent_end) : end;
920 btrfs_release_path(path);
921 return ret;
922 }
923
924 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
925 struct btrfs_root *root, struct inode *inode, u64 start,
926 u64 end, int drop_cache)
927 {
928 struct btrfs_path *path;
929 int ret;
930
931 path = btrfs_alloc_path();
932 if (!path)
933 return -ENOMEM;
934 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
935 drop_cache);
936 btrfs_free_path(path);
937 return ret;
938 }
939
940 static int extent_mergeable(struct extent_buffer *leaf, int slot,
941 u64 objectid, u64 bytenr, u64 orig_offset,
942 u64 *start, u64 *end)
943 {
944 struct btrfs_file_extent_item *fi;
945 struct btrfs_key key;
946 u64 extent_end;
947
948 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
949 return 0;
950
951 btrfs_item_key_to_cpu(leaf, &key, slot);
952 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
953 return 0;
954
955 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
956 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
957 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
958 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
959 btrfs_file_extent_compression(leaf, fi) ||
960 btrfs_file_extent_encryption(leaf, fi) ||
961 btrfs_file_extent_other_encoding(leaf, fi))
962 return 0;
963
964 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
965 if ((*start && *start != key.offset) || (*end && *end != extent_end))
966 return 0;
967
968 *start = key.offset;
969 *end = extent_end;
970 return 1;
971 }
972
973 /*
974 * Mark extent in the range start - end as written.
975 *
976 * This changes extent type from 'pre-allocated' to 'regular'. If only
977 * part of extent is marked as written, the extent will be split into
978 * two or three.
979 */
980 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
981 struct inode *inode, u64 start, u64 end)
982 {
983 struct btrfs_root *root = BTRFS_I(inode)->root;
984 struct extent_buffer *leaf;
985 struct btrfs_path *path;
986 struct btrfs_file_extent_item *fi;
987 struct btrfs_key key;
988 struct btrfs_key new_key;
989 u64 bytenr;
990 u64 num_bytes;
991 u64 extent_end;
992 u64 orig_offset;
993 u64 other_start;
994 u64 other_end;
995 u64 split;
996 int del_nr = 0;
997 int del_slot = 0;
998 int recow;
999 int ret;
1000 u64 ino = btrfs_ino(inode);
1001
1002 path = btrfs_alloc_path();
1003 if (!path)
1004 return -ENOMEM;
1005 again:
1006 recow = 0;
1007 split = start;
1008 key.objectid = ino;
1009 key.type = BTRFS_EXTENT_DATA_KEY;
1010 key.offset = split;
1011
1012 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1013 if (ret < 0)
1014 goto out;
1015 if (ret > 0 && path->slots[0] > 0)
1016 path->slots[0]--;
1017
1018 leaf = path->nodes[0];
1019 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1020 BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY);
1021 fi = btrfs_item_ptr(leaf, path->slots[0],
1022 struct btrfs_file_extent_item);
1023 BUG_ON(btrfs_file_extent_type(leaf, fi) !=
1024 BTRFS_FILE_EXTENT_PREALLOC);
1025 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1026 BUG_ON(key.offset > start || extent_end < end);
1027
1028 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1029 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1030 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1031 memcpy(&new_key, &key, sizeof(new_key));
1032
1033 if (start == key.offset && end < extent_end) {
1034 other_start = 0;
1035 other_end = start;
1036 if (extent_mergeable(leaf, path->slots[0] - 1,
1037 ino, bytenr, orig_offset,
1038 &other_start, &other_end)) {
1039 new_key.offset = end;
1040 btrfs_set_item_key_safe(trans, root, path, &new_key);
1041 fi = btrfs_item_ptr(leaf, path->slots[0],
1042 struct btrfs_file_extent_item);
1043 btrfs_set_file_extent_generation(leaf, fi,
1044 trans->transid);
1045 btrfs_set_file_extent_num_bytes(leaf, fi,
1046 extent_end - end);
1047 btrfs_set_file_extent_offset(leaf, fi,
1048 end - orig_offset);
1049 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1050 struct btrfs_file_extent_item);
1051 btrfs_set_file_extent_generation(leaf, fi,
1052 trans->transid);
1053 btrfs_set_file_extent_num_bytes(leaf, fi,
1054 end - other_start);
1055 btrfs_mark_buffer_dirty(leaf);
1056 goto out;
1057 }
1058 }
1059
1060 if (start > key.offset && end == extent_end) {
1061 other_start = end;
1062 other_end = 0;
1063 if (extent_mergeable(leaf, path->slots[0] + 1,
1064 ino, bytenr, orig_offset,
1065 &other_start, &other_end)) {
1066 fi = btrfs_item_ptr(leaf, path->slots[0],
1067 struct btrfs_file_extent_item);
1068 btrfs_set_file_extent_num_bytes(leaf, fi,
1069 start - key.offset);
1070 btrfs_set_file_extent_generation(leaf, fi,
1071 trans->transid);
1072 path->slots[0]++;
1073 new_key.offset = start;
1074 btrfs_set_item_key_safe(trans, root, path, &new_key);
1075
1076 fi = btrfs_item_ptr(leaf, path->slots[0],
1077 struct btrfs_file_extent_item);
1078 btrfs_set_file_extent_generation(leaf, fi,
1079 trans->transid);
1080 btrfs_set_file_extent_num_bytes(leaf, fi,
1081 other_end - start);
1082 btrfs_set_file_extent_offset(leaf, fi,
1083 start - orig_offset);
1084 btrfs_mark_buffer_dirty(leaf);
1085 goto out;
1086 }
1087 }
1088
1089 while (start > key.offset || end < extent_end) {
1090 if (key.offset == start)
1091 split = end;
1092
1093 new_key.offset = split;
1094 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1095 if (ret == -EAGAIN) {
1096 btrfs_release_path(path);
1097 goto again;
1098 }
1099 if (ret < 0) {
1100 btrfs_abort_transaction(trans, root, ret);
1101 goto out;
1102 }
1103
1104 leaf = path->nodes[0];
1105 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1106 struct btrfs_file_extent_item);
1107 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1108 btrfs_set_file_extent_num_bytes(leaf, fi,
1109 split - key.offset);
1110
1111 fi = btrfs_item_ptr(leaf, path->slots[0],
1112 struct btrfs_file_extent_item);
1113
1114 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1115 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1116 btrfs_set_file_extent_num_bytes(leaf, fi,
1117 extent_end - split);
1118 btrfs_mark_buffer_dirty(leaf);
1119
1120 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
1121 root->root_key.objectid,
1122 ino, orig_offset, 0);
1123 BUG_ON(ret); /* -ENOMEM */
1124
1125 if (split == start) {
1126 key.offset = start;
1127 } else {
1128 BUG_ON(start != key.offset);
1129 path->slots[0]--;
1130 extent_end = end;
1131 }
1132 recow = 1;
1133 }
1134
1135 other_start = end;
1136 other_end = 0;
1137 if (extent_mergeable(leaf, path->slots[0] + 1,
1138 ino, bytenr, orig_offset,
1139 &other_start, &other_end)) {
1140 if (recow) {
1141 btrfs_release_path(path);
1142 goto again;
1143 }
1144 extent_end = other_end;
1145 del_slot = path->slots[0] + 1;
1146 del_nr++;
1147 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1148 0, root->root_key.objectid,
1149 ino, orig_offset, 0);
1150 BUG_ON(ret); /* -ENOMEM */
1151 }
1152 other_start = 0;
1153 other_end = start;
1154 if (extent_mergeable(leaf, path->slots[0] - 1,
1155 ino, bytenr, orig_offset,
1156 &other_start, &other_end)) {
1157 if (recow) {
1158 btrfs_release_path(path);
1159 goto again;
1160 }
1161 key.offset = other_start;
1162 del_slot = path->slots[0];
1163 del_nr++;
1164 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1165 0, root->root_key.objectid,
1166 ino, orig_offset, 0);
1167 BUG_ON(ret); /* -ENOMEM */
1168 }
1169 if (del_nr == 0) {
1170 fi = btrfs_item_ptr(leaf, path->slots[0],
1171 struct btrfs_file_extent_item);
1172 btrfs_set_file_extent_type(leaf, fi,
1173 BTRFS_FILE_EXTENT_REG);
1174 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1175 btrfs_mark_buffer_dirty(leaf);
1176 } else {
1177 fi = btrfs_item_ptr(leaf, del_slot - 1,
1178 struct btrfs_file_extent_item);
1179 btrfs_set_file_extent_type(leaf, fi,
1180 BTRFS_FILE_EXTENT_REG);
1181 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1182 btrfs_set_file_extent_num_bytes(leaf, fi,
1183 extent_end - key.offset);
1184 btrfs_mark_buffer_dirty(leaf);
1185
1186 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1187 if (ret < 0) {
1188 btrfs_abort_transaction(trans, root, ret);
1189 goto out;
1190 }
1191 }
1192 out:
1193 btrfs_free_path(path);
1194 return 0;
1195 }
1196
1197 /*
1198 * on error we return an unlocked page and the error value
1199 * on success we return a locked page and 0
1200 */
1201 static int prepare_uptodate_page(struct page *page, u64 pos,
1202 bool force_uptodate)
1203 {
1204 int ret = 0;
1205
1206 if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
1207 !PageUptodate(page)) {
1208 ret = btrfs_readpage(NULL, page);
1209 if (ret)
1210 return ret;
1211 lock_page(page);
1212 if (!PageUptodate(page)) {
1213 unlock_page(page);
1214 return -EIO;
1215 }
1216 }
1217 return 0;
1218 }
1219
1220 /*
1221 * this gets pages into the page cache and locks them down, it also properly
1222 * waits for data=ordered extents to finish before allowing the pages to be
1223 * modified.
1224 */
1225 static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
1226 struct page **pages, size_t num_pages,
1227 loff_t pos, unsigned long first_index,
1228 size_t write_bytes, bool force_uptodate)
1229 {
1230 struct extent_state *cached_state = NULL;
1231 int i;
1232 unsigned long index = pos >> PAGE_CACHE_SHIFT;
1233 struct inode *inode = file_inode(file);
1234 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1235 int err = 0;
1236 int faili = 0;
1237 u64 start_pos;
1238 u64 last_pos;
1239
1240 start_pos = pos & ~((u64)root->sectorsize - 1);
1241 last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
1242
1243 again:
1244 for (i = 0; i < num_pages; i++) {
1245 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1246 mask | __GFP_WRITE);
1247 if (!pages[i]) {
1248 faili = i - 1;
1249 err = -ENOMEM;
1250 goto fail;
1251 }
1252
1253 if (i == 0)
1254 err = prepare_uptodate_page(pages[i], pos,
1255 force_uptodate);
1256 if (i == num_pages - 1)
1257 err = prepare_uptodate_page(pages[i],
1258 pos + write_bytes, false);
1259 if (err) {
1260 page_cache_release(pages[i]);
1261 faili = i - 1;
1262 goto fail;
1263 }
1264 wait_on_page_writeback(pages[i]);
1265 }
1266 err = 0;
1267 if (start_pos < inode->i_size) {
1268 struct btrfs_ordered_extent *ordered;
1269 lock_extent_bits(&BTRFS_I(inode)->io_tree,
1270 start_pos, last_pos - 1, 0, &cached_state);
1271 ordered = btrfs_lookup_first_ordered_extent(inode,
1272 last_pos - 1);
1273 if (ordered &&
1274 ordered->file_offset + ordered->len > start_pos &&
1275 ordered->file_offset < last_pos) {
1276 btrfs_put_ordered_extent(ordered);
1277 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1278 start_pos, last_pos - 1,
1279 &cached_state, GFP_NOFS);
1280 for (i = 0; i < num_pages; i++) {
1281 unlock_page(pages[i]);
1282 page_cache_release(pages[i]);
1283 }
1284 btrfs_wait_ordered_range(inode, start_pos,
1285 last_pos - start_pos);
1286 goto again;
1287 }
1288 if (ordered)
1289 btrfs_put_ordered_extent(ordered);
1290
1291 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
1292 last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1293 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
1294 0, 0, &cached_state, GFP_NOFS);
1295 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1296 start_pos, last_pos - 1, &cached_state,
1297 GFP_NOFS);
1298 }
1299 for (i = 0; i < num_pages; i++) {
1300 if (clear_page_dirty_for_io(pages[i]))
1301 account_page_redirty(pages[i]);
1302 set_page_extent_mapped(pages[i]);
1303 WARN_ON(!PageLocked(pages[i]));
1304 }
1305 return 0;
1306 fail:
1307 while (faili >= 0) {
1308 unlock_page(pages[faili]);
1309 page_cache_release(pages[faili]);
1310 faili--;
1311 }
1312 return err;
1313
1314 }
1315
1316 static noinline ssize_t __btrfs_buffered_write(struct file *file,
1317 struct iov_iter *i,
1318 loff_t pos)
1319 {
1320 struct inode *inode = file_inode(file);
1321 struct btrfs_root *root = BTRFS_I(inode)->root;
1322 struct page **pages = NULL;
1323 unsigned long first_index;
1324 size_t num_written = 0;
1325 int nrptrs;
1326 int ret = 0;
1327 bool force_page_uptodate = false;
1328
1329 nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
1330 PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
1331 (sizeof(struct page *)));
1332 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1333 nrptrs = max(nrptrs, 8);
1334 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
1335 if (!pages)
1336 return -ENOMEM;
1337
1338 first_index = pos >> PAGE_CACHE_SHIFT;
1339
1340 while (iov_iter_count(i) > 0) {
1341 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
1342 size_t write_bytes = min(iov_iter_count(i),
1343 nrptrs * (size_t)PAGE_CACHE_SIZE -
1344 offset);
1345 size_t num_pages = (write_bytes + offset +
1346 PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1347 size_t dirty_pages;
1348 size_t copied;
1349
1350 WARN_ON(num_pages > nrptrs);
1351
1352 /*
1353 * Fault pages before locking them in prepare_pages
1354 * to avoid recursive lock
1355 */
1356 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1357 ret = -EFAULT;
1358 break;
1359 }
1360
1361 ret = btrfs_delalloc_reserve_space(inode,
1362 num_pages << PAGE_CACHE_SHIFT);
1363 if (ret)
1364 break;
1365
1366 /*
1367 * This is going to setup the pages array with the number of
1368 * pages we want, so we don't really need to worry about the
1369 * contents of pages from loop to loop
1370 */
1371 ret = prepare_pages(root, file, pages, num_pages,
1372 pos, first_index, write_bytes,
1373 force_page_uptodate);
1374 if (ret) {
1375 btrfs_delalloc_release_space(inode,
1376 num_pages << PAGE_CACHE_SHIFT);
1377 break;
1378 }
1379
1380 copied = btrfs_copy_from_user(pos, num_pages,
1381 write_bytes, pages, i);
1382
1383 /*
1384 * if we have trouble faulting in the pages, fall
1385 * back to one page at a time
1386 */
1387 if (copied < write_bytes)
1388 nrptrs = 1;
1389
1390 if (copied == 0) {
1391 force_page_uptodate = true;
1392 dirty_pages = 0;
1393 } else {
1394 force_page_uptodate = false;
1395 dirty_pages = (copied + offset +
1396 PAGE_CACHE_SIZE - 1) >>
1397 PAGE_CACHE_SHIFT;
1398 }
1399
1400 /*
1401 * If we had a short copy we need to release the excess delaloc
1402 * bytes we reserved. We need to increment outstanding_extents
1403 * because btrfs_delalloc_release_space will decrement it, but
1404 * we still have an outstanding extent for the chunk we actually
1405 * managed to copy.
1406 */
1407 if (num_pages > dirty_pages) {
1408 if (copied > 0) {
1409 spin_lock(&BTRFS_I(inode)->lock);
1410 BTRFS_I(inode)->outstanding_extents++;
1411 spin_unlock(&BTRFS_I(inode)->lock);
1412 }
1413 btrfs_delalloc_release_space(inode,
1414 (num_pages - dirty_pages) <<
1415 PAGE_CACHE_SHIFT);
1416 }
1417
1418 if (copied > 0) {
1419 ret = btrfs_dirty_pages(root, inode, pages,
1420 dirty_pages, pos, copied,
1421 NULL);
1422 if (ret) {
1423 btrfs_delalloc_release_space(inode,
1424 dirty_pages << PAGE_CACHE_SHIFT);
1425 btrfs_drop_pages(pages, num_pages);
1426 break;
1427 }
1428 }
1429
1430 btrfs_drop_pages(pages, num_pages);
1431
1432 cond_resched();
1433
1434 balance_dirty_pages_ratelimited(inode->i_mapping);
1435 if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
1436 btrfs_btree_balance_dirty(root);
1437
1438 pos += copied;
1439 num_written += copied;
1440 }
1441
1442 kfree(pages);
1443
1444 return num_written ? num_written : ret;
1445 }
1446
1447 static ssize_t __btrfs_direct_write(struct kiocb *iocb,
1448 const struct iovec *iov,
1449 unsigned long nr_segs, loff_t pos,
1450 loff_t *ppos, size_t count, size_t ocount)
1451 {
1452 struct file *file = iocb->ki_filp;
1453 struct iov_iter i;
1454 ssize_t written;
1455 ssize_t written_buffered;
1456 loff_t endbyte;
1457 int err;
1458
1459 written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos,
1460 count, ocount);
1461
1462 if (written < 0 || written == count)
1463 return written;
1464
1465 pos += written;
1466 count -= written;
1467 iov_iter_init(&i, iov, nr_segs, count, written);
1468 written_buffered = __btrfs_buffered_write(file, &i, pos);
1469 if (written_buffered < 0) {
1470 err = written_buffered;
1471 goto out;
1472 }
1473 endbyte = pos + written_buffered - 1;
1474 err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
1475 if (err)
1476 goto out;
1477 written += written_buffered;
1478 *ppos = pos + written_buffered;
1479 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,
1480 endbyte >> PAGE_CACHE_SHIFT);
1481 out:
1482 return written ? written : err;
1483 }
1484
1485 static void update_time_for_write(struct inode *inode)
1486 {
1487 struct timespec now;
1488
1489 if (IS_NOCMTIME(inode))
1490 return;
1491
1492 now = current_fs_time(inode->i_sb);
1493 if (!timespec_equal(&inode->i_mtime, &now))
1494 inode->i_mtime = now;
1495
1496 if (!timespec_equal(&inode->i_ctime, &now))
1497 inode->i_ctime = now;
1498
1499 if (IS_I_VERSION(inode))
1500 inode_inc_iversion(inode);
1501 }
1502
1503 static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
1504 const struct iovec *iov,
1505 unsigned long nr_segs, loff_t pos)
1506 {
1507 struct file *file = iocb->ki_filp;
1508 struct inode *inode = file_inode(file);
1509 struct btrfs_root *root = BTRFS_I(inode)->root;
1510 loff_t *ppos = &iocb->ki_pos;
1511 u64 start_pos;
1512 ssize_t num_written = 0;
1513 ssize_t err = 0;
1514 size_t count, ocount;
1515 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
1516
1517 mutex_lock(&inode->i_mutex);
1518
1519 err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
1520 if (err) {
1521 mutex_unlock(&inode->i_mutex);
1522 goto out;
1523 }
1524 count = ocount;
1525
1526 current->backing_dev_info = inode->i_mapping->backing_dev_info;
1527 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1528 if (err) {
1529 mutex_unlock(&inode->i_mutex);
1530 goto out;
1531 }
1532
1533 if (count == 0) {
1534 mutex_unlock(&inode->i_mutex);
1535 goto out;
1536 }
1537
1538 err = file_remove_suid(file);
1539 if (err) {
1540 mutex_unlock(&inode->i_mutex);
1541 goto out;
1542 }
1543
1544 /*
1545 * If BTRFS flips readonly due to some impossible error
1546 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1547 * although we have opened a file as writable, we have
1548 * to stop this write operation to ensure FS consistency.
1549 */
1550 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1551 mutex_unlock(&inode->i_mutex);
1552 err = -EROFS;
1553 goto out;
1554 }
1555
1556 /*
1557 * We reserve space for updating the inode when we reserve space for the
1558 * extent we are going to write, so we will enospc out there. We don't
1559 * need to start yet another transaction to update the inode as we will
1560 * update the inode when we finish writing whatever data we write.
1561 */
1562 update_time_for_write(inode);
1563
1564 start_pos = round_down(pos, root->sectorsize);
1565 if (start_pos > i_size_read(inode)) {
1566 err = btrfs_cont_expand(inode, i_size_read(inode), start_pos);
1567 if (err) {
1568 mutex_unlock(&inode->i_mutex);
1569 goto out;
1570 }
1571 }
1572
1573 if (sync)
1574 atomic_inc(&BTRFS_I(inode)->sync_writers);
1575
1576 if (unlikely(file->f_flags & O_DIRECT)) {
1577 num_written = __btrfs_direct_write(iocb, iov, nr_segs,
1578 pos, ppos, count, ocount);
1579 } else {
1580 struct iov_iter i;
1581
1582 iov_iter_init(&i, iov, nr_segs, count, num_written);
1583
1584 num_written = __btrfs_buffered_write(file, &i, pos);
1585 if (num_written > 0)
1586 *ppos = pos + num_written;
1587 }
1588
1589 mutex_unlock(&inode->i_mutex);
1590
1591 /*
1592 * we want to make sure fsync finds this change
1593 * but we haven't joined a transaction running right now.
1594 *
1595 * Later on, someone is sure to update the inode and get the
1596 * real transid recorded.
1597 *
1598 * We set last_trans now to the fs_info generation + 1,
1599 * this will either be one more than the running transaction
1600 * or the generation used for the next transaction if there isn't
1601 * one running right now.
1602 *
1603 * We also have to set last_sub_trans to the current log transid,
1604 * otherwise subsequent syncs to a file that's been synced in this
1605 * transaction will appear to have already occured.
1606 */
1607 BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
1608 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1609 if (num_written > 0 || num_written == -EIOCBQUEUED) {
1610 err = generic_write_sync(file, pos, num_written);
1611 if (err < 0 && num_written > 0)
1612 num_written = err;
1613 }
1614
1615 if (sync)
1616 atomic_dec(&BTRFS_I(inode)->sync_writers);
1617 out:
1618 current->backing_dev_info = NULL;
1619 return num_written ? num_written : err;
1620 }
1621
1622 int btrfs_release_file(struct inode *inode, struct file *filp)
1623 {
1624 /*
1625 * ordered_data_close is set by settattr when we are about to truncate
1626 * a file from a non-zero size to a zero size. This tries to
1627 * flush down new bytes that may have been written if the
1628 * application were using truncate to replace a file in place.
1629 */
1630 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
1631 &BTRFS_I(inode)->runtime_flags)) {
1632 struct btrfs_trans_handle *trans;
1633 struct btrfs_root *root = BTRFS_I(inode)->root;
1634
1635 /*
1636 * We need to block on a committing transaction to keep us from
1637 * throwing a ordered operation on to the list and causing
1638 * something like sync to deadlock trying to flush out this
1639 * inode.
1640 */
1641 trans = btrfs_start_transaction(root, 0);
1642 if (IS_ERR(trans))
1643 return PTR_ERR(trans);
1644 btrfs_add_ordered_operation(trans, BTRFS_I(inode)->root, inode);
1645 btrfs_end_transaction(trans, root);
1646 if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
1647 filemap_flush(inode->i_mapping);
1648 }
1649 if (filp->private_data)
1650 btrfs_ioctl_trans_end(filp);
1651 return 0;
1652 }
1653
1654 /*
1655 * fsync call for both files and directories. This logs the inode into
1656 * the tree log instead of forcing full commits whenever possible.
1657 *
1658 * It needs to call filemap_fdatawait so that all ordered extent updates are
1659 * in the metadata btree are up to date for copying to the log.
1660 *
1661 * It drops the inode mutex before doing the tree log commit. This is an
1662 * important optimization for directories because holding the mutex prevents
1663 * new operations on the dir while we write to disk.
1664 */
1665 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
1666 {
1667 struct dentry *dentry = file->f_path.dentry;
1668 struct inode *inode = dentry->d_inode;
1669 struct btrfs_root *root = BTRFS_I(inode)->root;
1670 int ret = 0;
1671 struct btrfs_trans_handle *trans;
1672 bool full_sync = 0;
1673
1674 trace_btrfs_sync_file(file, datasync);
1675
1676 /*
1677 * We write the dirty pages in the range and wait until they complete
1678 * out of the ->i_mutex. If so, we can flush the dirty pages by
1679 * multi-task, and make the performance up. See
1680 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
1681 */
1682 atomic_inc(&BTRFS_I(inode)->sync_writers);
1683 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
1684 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1685 &BTRFS_I(inode)->runtime_flags))
1686 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
1687 atomic_dec(&BTRFS_I(inode)->sync_writers);
1688 if (ret)
1689 return ret;
1690
1691 mutex_lock(&inode->i_mutex);
1692
1693 /*
1694 * We flush the dirty pages again to avoid some dirty pages in the
1695 * range being left.
1696 */
1697 atomic_inc(&root->log_batch);
1698 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1699 &BTRFS_I(inode)->runtime_flags);
1700 if (full_sync)
1701 btrfs_wait_ordered_range(inode, start, end - start + 1);
1702 atomic_inc(&root->log_batch);
1703
1704 /*
1705 * check the transaction that last modified this inode
1706 * and see if its already been committed
1707 */
1708 if (!BTRFS_I(inode)->last_trans) {
1709 mutex_unlock(&inode->i_mutex);
1710 goto out;
1711 }
1712
1713 /*
1714 * if the last transaction that changed this file was before
1715 * the current transaction, we can bail out now without any
1716 * syncing
1717 */
1718 smp_mb();
1719 if (btrfs_inode_in_log(inode, root->fs_info->generation) ||
1720 BTRFS_I(inode)->last_trans <=
1721 root->fs_info->last_trans_committed) {
1722 BTRFS_I(inode)->last_trans = 0;
1723
1724 /*
1725 * We'v had everything committed since the last time we were
1726 * modified so clear this flag in case it was set for whatever
1727 * reason, it's no longer relevant.
1728 */
1729 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1730 &BTRFS_I(inode)->runtime_flags);
1731 mutex_unlock(&inode->i_mutex);
1732 goto out;
1733 }
1734
1735 /*
1736 * ok we haven't committed the transaction yet, lets do a commit
1737 */
1738 if (file->private_data)
1739 btrfs_ioctl_trans_end(file);
1740
1741 trans = btrfs_start_transaction(root, 0);
1742 if (IS_ERR(trans)) {
1743 ret = PTR_ERR(trans);
1744 mutex_unlock(&inode->i_mutex);
1745 goto out;
1746 }
1747
1748 ret = btrfs_log_dentry_safe(trans, root, dentry);
1749 if (ret < 0) {
1750 mutex_unlock(&inode->i_mutex);
1751 goto out;
1752 }
1753
1754 /* we've logged all the items and now have a consistent
1755 * version of the file in the log. It is possible that
1756 * someone will come in and modify the file, but that's
1757 * fine because the log is consistent on disk, and we
1758 * have references to all of the file's extents
1759 *
1760 * It is possible that someone will come in and log the
1761 * file again, but that will end up using the synchronization
1762 * inside btrfs_sync_log to keep things safe.
1763 */
1764 mutex_unlock(&inode->i_mutex);
1765
1766 if (ret != BTRFS_NO_LOG_SYNC) {
1767 if (ret > 0) {
1768 /*
1769 * If we didn't already wait for ordered extents we need
1770 * to do that now.
1771 */
1772 if (!full_sync)
1773 btrfs_wait_ordered_range(inode, start,
1774 end - start + 1);
1775 ret = btrfs_commit_transaction(trans, root);
1776 } else {
1777 ret = btrfs_sync_log(trans, root);
1778 if (ret == 0) {
1779 ret = btrfs_end_transaction(trans, root);
1780 } else {
1781 if (!full_sync)
1782 btrfs_wait_ordered_range(inode, start,
1783 end -
1784 start + 1);
1785 ret = btrfs_commit_transaction(trans, root);
1786 }
1787 }
1788 } else {
1789 ret = btrfs_end_transaction(trans, root);
1790 }
1791 out:
1792 return ret > 0 ? -EIO : ret;
1793 }
1794
1795 static const struct vm_operations_struct btrfs_file_vm_ops = {
1796 .fault = filemap_fault,
1797 .page_mkwrite = btrfs_page_mkwrite,
1798 .remap_pages = generic_file_remap_pages,
1799 };
1800
1801 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
1802 {
1803 struct address_space *mapping = filp->f_mapping;
1804
1805 if (!mapping->a_ops->readpage)
1806 return -ENOEXEC;
1807
1808 file_accessed(filp);
1809 vma->vm_ops = &btrfs_file_vm_ops;
1810
1811 return 0;
1812 }
1813
1814 static int hole_mergeable(struct inode *inode, struct extent_buffer *leaf,
1815 int slot, u64 start, u64 end)
1816 {
1817 struct btrfs_file_extent_item *fi;
1818 struct btrfs_key key;
1819
1820 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1821 return 0;
1822
1823 btrfs_item_key_to_cpu(leaf, &key, slot);
1824 if (key.objectid != btrfs_ino(inode) ||
1825 key.type != BTRFS_EXTENT_DATA_KEY)
1826 return 0;
1827
1828 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1829
1830 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
1831 return 0;
1832
1833 if (btrfs_file_extent_disk_bytenr(leaf, fi))
1834 return 0;
1835
1836 if (key.offset == end)
1837 return 1;
1838 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
1839 return 1;
1840 return 0;
1841 }
1842
1843 static int fill_holes(struct btrfs_trans_handle *trans, struct inode *inode,
1844 struct btrfs_path *path, u64 offset, u64 end)
1845 {
1846 struct btrfs_root *root = BTRFS_I(inode)->root;
1847 struct extent_buffer *leaf;
1848 struct btrfs_file_extent_item *fi;
1849 struct extent_map *hole_em;
1850 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1851 struct btrfs_key key;
1852 int ret;
1853
1854 key.objectid = btrfs_ino(inode);
1855 key.type = BTRFS_EXTENT_DATA_KEY;
1856 key.offset = offset;
1857
1858
1859 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1860 if (ret < 0)
1861 return ret;
1862 BUG_ON(!ret);
1863
1864 leaf = path->nodes[0];
1865 if (hole_mergeable(inode, leaf, path->slots[0]-1, offset, end)) {
1866 u64 num_bytes;
1867
1868 path->slots[0]--;
1869 fi = btrfs_item_ptr(leaf, path->slots[0],
1870 struct btrfs_file_extent_item);
1871 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
1872 end - offset;
1873 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1874 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
1875 btrfs_set_file_extent_offset(leaf, fi, 0);
1876 btrfs_mark_buffer_dirty(leaf);
1877 goto out;
1878 }
1879
1880 if (hole_mergeable(inode, leaf, path->slots[0]+1, offset, end)) {
1881 u64 num_bytes;
1882
1883 path->slots[0]++;
1884 key.offset = offset;
1885 btrfs_set_item_key_safe(trans, root, path, &key);
1886 fi = btrfs_item_ptr(leaf, path->slots[0],
1887 struct btrfs_file_extent_item);
1888 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
1889 offset;
1890 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1891 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
1892 btrfs_set_file_extent_offset(leaf, fi, 0);
1893 btrfs_mark_buffer_dirty(leaf);
1894 goto out;
1895 }
1896 btrfs_release_path(path);
1897
1898 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
1899 0, 0, end - offset, 0, end - offset,
1900 0, 0, 0);
1901 if (ret)
1902 return ret;
1903
1904 out:
1905 btrfs_release_path(path);
1906
1907 hole_em = alloc_extent_map();
1908 if (!hole_em) {
1909 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
1910 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1911 &BTRFS_I(inode)->runtime_flags);
1912 } else {
1913 hole_em->start = offset;
1914 hole_em->len = end - offset;
1915 hole_em->orig_start = offset;
1916
1917 hole_em->block_start = EXTENT_MAP_HOLE;
1918 hole_em->block_len = 0;
1919 hole_em->orig_block_len = 0;
1920 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
1921 hole_em->compress_type = BTRFS_COMPRESS_NONE;
1922 hole_em->generation = trans->transid;
1923
1924 do {
1925 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
1926 write_lock(&em_tree->lock);
1927 ret = add_extent_mapping(em_tree, hole_em);
1928 if (!ret)
1929 list_move(&hole_em->list,
1930 &em_tree->modified_extents);
1931 write_unlock(&em_tree->lock);
1932 } while (ret == -EEXIST);
1933 free_extent_map(hole_em);
1934 if (ret)
1935 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1936 &BTRFS_I(inode)->runtime_flags);
1937 }
1938
1939 return 0;
1940 }
1941
1942 static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
1943 {
1944 struct btrfs_root *root = BTRFS_I(inode)->root;
1945 struct extent_state *cached_state = NULL;
1946 struct btrfs_path *path;
1947 struct btrfs_block_rsv *rsv;
1948 struct btrfs_trans_handle *trans;
1949 u64 lockstart = round_up(offset, BTRFS_I(inode)->root->sectorsize);
1950 u64 lockend = round_down(offset + len,
1951 BTRFS_I(inode)->root->sectorsize) - 1;
1952 u64 cur_offset = lockstart;
1953 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
1954 u64 drop_end;
1955 int ret = 0;
1956 int err = 0;
1957 bool same_page = ((offset >> PAGE_CACHE_SHIFT) ==
1958 ((offset + len - 1) >> PAGE_CACHE_SHIFT));
1959
1960 btrfs_wait_ordered_range(inode, offset, len);
1961
1962 mutex_lock(&inode->i_mutex);
1963 /*
1964 * We needn't truncate any page which is beyond the end of the file
1965 * because we are sure there is no data there.
1966 */
1967 /*
1968 * Only do this if we are in the same page and we aren't doing the
1969 * entire page.
1970 */
1971 if (same_page && len < PAGE_CACHE_SIZE) {
1972 if (offset < round_up(inode->i_size, PAGE_CACHE_SIZE))
1973 ret = btrfs_truncate_page(inode, offset, len, 0);
1974 mutex_unlock(&inode->i_mutex);
1975 return ret;
1976 }
1977
1978 /* zero back part of the first page */
1979 if (offset < round_up(inode->i_size, PAGE_CACHE_SIZE)) {
1980 ret = btrfs_truncate_page(inode, offset, 0, 0);
1981 if (ret) {
1982 mutex_unlock(&inode->i_mutex);
1983 return ret;
1984 }
1985 }
1986
1987 /* zero the front end of the last page */
1988 if (offset + len < round_up(inode->i_size, PAGE_CACHE_SIZE)) {
1989 ret = btrfs_truncate_page(inode, offset + len, 0, 1);
1990 if (ret) {
1991 mutex_unlock(&inode->i_mutex);
1992 return ret;
1993 }
1994 }
1995
1996 if (lockend < lockstart) {
1997 mutex_unlock(&inode->i_mutex);
1998 return 0;
1999 }
2000
2001 while (1) {
2002 struct btrfs_ordered_extent *ordered;
2003
2004 truncate_pagecache_range(inode, lockstart, lockend);
2005
2006 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2007 0, &cached_state);
2008 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2009
2010 /*
2011 * We need to make sure we have no ordered extents in this range
2012 * and nobody raced in and read a page in this range, if we did
2013 * we need to try again.
2014 */
2015 if ((!ordered ||
2016 (ordered->file_offset + ordered->len < lockstart ||
2017 ordered->file_offset > lockend)) &&
2018 !test_range_bit(&BTRFS_I(inode)->io_tree, lockstart,
2019 lockend, EXTENT_UPTODATE, 0,
2020 cached_state)) {
2021 if (ordered)
2022 btrfs_put_ordered_extent(ordered);
2023 break;
2024 }
2025 if (ordered)
2026 btrfs_put_ordered_extent(ordered);
2027 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2028 lockend, &cached_state, GFP_NOFS);
2029 btrfs_wait_ordered_range(inode, lockstart,
2030 lockend - lockstart + 1);
2031 }
2032
2033 path = btrfs_alloc_path();
2034 if (!path) {
2035 ret = -ENOMEM;
2036 goto out;
2037 }
2038
2039 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2040 if (!rsv) {
2041 ret = -ENOMEM;
2042 goto out_free;
2043 }
2044 rsv->size = btrfs_calc_trunc_metadata_size(root, 1);
2045 rsv->failfast = 1;
2046
2047 /*
2048 * 1 - update the inode
2049 * 1 - removing the extents in the range
2050 * 1 - adding the hole extent
2051 */
2052 trans = btrfs_start_transaction(root, 3);
2053 if (IS_ERR(trans)) {
2054 err = PTR_ERR(trans);
2055 goto out_free;
2056 }
2057
2058 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
2059 min_size);
2060 BUG_ON(ret);
2061 trans->block_rsv = rsv;
2062
2063 while (cur_offset < lockend) {
2064 ret = __btrfs_drop_extents(trans, root, inode, path,
2065 cur_offset, lockend + 1,
2066 &drop_end, 1);
2067 if (ret != -ENOSPC)
2068 break;
2069
2070 trans->block_rsv = &root->fs_info->trans_block_rsv;
2071
2072 ret = fill_holes(trans, inode, path, cur_offset, drop_end);
2073 if (ret) {
2074 err = ret;
2075 break;
2076 }
2077
2078 cur_offset = drop_end;
2079
2080 ret = btrfs_update_inode(trans, root, inode);
2081 if (ret) {
2082 err = ret;
2083 break;
2084 }
2085
2086 btrfs_end_transaction(trans, root);
2087 btrfs_btree_balance_dirty(root);
2088
2089 trans = btrfs_start_transaction(root, 3);
2090 if (IS_ERR(trans)) {
2091 ret = PTR_ERR(trans);
2092 trans = NULL;
2093 break;
2094 }
2095
2096 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
2097 rsv, min_size);
2098 BUG_ON(ret); /* shouldn't happen */
2099 trans->block_rsv = rsv;
2100 }
2101
2102 if (ret) {
2103 err = ret;
2104 goto out_trans;
2105 }
2106
2107 trans->block_rsv = &root->fs_info->trans_block_rsv;
2108 ret = fill_holes(trans, inode, path, cur_offset, drop_end);
2109 if (ret) {
2110 err = ret;
2111 goto out_trans;
2112 }
2113
2114 out_trans:
2115 if (!trans)
2116 goto out_free;
2117
2118 inode_inc_iversion(inode);
2119 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2120
2121 trans->block_rsv = &root->fs_info->trans_block_rsv;
2122 ret = btrfs_update_inode(trans, root, inode);
2123 btrfs_end_transaction(trans, root);
2124 btrfs_btree_balance_dirty(root);
2125 out_free:
2126 btrfs_free_path(path);
2127 btrfs_free_block_rsv(root, rsv);
2128 out:
2129 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2130 &cached_state, GFP_NOFS);
2131 mutex_unlock(&inode->i_mutex);
2132 if (ret && !err)
2133 err = ret;
2134 return err;
2135 }
2136
2137 static long btrfs_fallocate(struct file *file, int mode,
2138 loff_t offset, loff_t len)
2139 {
2140 struct inode *inode = file_inode(file);
2141 struct extent_state *cached_state = NULL;
2142 struct btrfs_root *root = BTRFS_I(inode)->root;
2143 u64 cur_offset;
2144 u64 last_byte;
2145 u64 alloc_start;
2146 u64 alloc_end;
2147 u64 alloc_hint = 0;
2148 u64 locked_end;
2149 struct extent_map *em;
2150 int blocksize = BTRFS_I(inode)->root->sectorsize;
2151 int ret;
2152
2153 alloc_start = round_down(offset, blocksize);
2154 alloc_end = round_up(offset + len, blocksize);
2155
2156 /* Make sure we aren't being give some crap mode */
2157 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
2158 return -EOPNOTSUPP;
2159
2160 if (mode & FALLOC_FL_PUNCH_HOLE)
2161 return btrfs_punch_hole(inode, offset, len);
2162
2163 /*
2164 * Make sure we have enough space before we do the
2165 * allocation.
2166 */
2167 ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
2168 if (ret)
2169 return ret;
2170 if (root->fs_info->quota_enabled) {
2171 ret = btrfs_qgroup_reserve(root, alloc_end - alloc_start);
2172 if (ret)
2173 goto out_reserve_fail;
2174 }
2175
2176 /*
2177 * wait for ordered IO before we have any locks. We'll loop again
2178 * below with the locks held.
2179 */
2180 btrfs_wait_ordered_range(inode, alloc_start, alloc_end - alloc_start);
2181
2182 mutex_lock(&inode->i_mutex);
2183 ret = inode_newsize_ok(inode, alloc_end);
2184 if (ret)
2185 goto out;
2186
2187 if (alloc_start > inode->i_size) {
2188 ret = btrfs_cont_expand(inode, i_size_read(inode),
2189 alloc_start);
2190 if (ret)
2191 goto out;
2192 }
2193
2194 locked_end = alloc_end - 1;
2195 while (1) {
2196 struct btrfs_ordered_extent *ordered;
2197
2198 /* the extent lock is ordered inside the running
2199 * transaction
2200 */
2201 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
2202 locked_end, 0, &cached_state);
2203 ordered = btrfs_lookup_first_ordered_extent(inode,
2204 alloc_end - 1);
2205 if (ordered &&
2206 ordered->file_offset + ordered->len > alloc_start &&
2207 ordered->file_offset < alloc_end) {
2208 btrfs_put_ordered_extent(ordered);
2209 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
2210 alloc_start, locked_end,
2211 &cached_state, GFP_NOFS);
2212 /*
2213 * we can't wait on the range with the transaction
2214 * running or with the extent lock held
2215 */
2216 btrfs_wait_ordered_range(inode, alloc_start,
2217 alloc_end - alloc_start);
2218 } else {
2219 if (ordered)
2220 btrfs_put_ordered_extent(ordered);
2221 break;
2222 }
2223 }
2224
2225 cur_offset = alloc_start;
2226 while (1) {
2227 u64 actual_end;
2228
2229 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
2230 alloc_end - cur_offset, 0);
2231 if (IS_ERR_OR_NULL(em)) {
2232 if (!em)
2233 ret = -ENOMEM;
2234 else
2235 ret = PTR_ERR(em);
2236 break;
2237 }
2238 last_byte = min(extent_map_end(em), alloc_end);
2239 actual_end = min_t(u64, extent_map_end(em), offset + len);
2240 last_byte = ALIGN(last_byte, blocksize);
2241
2242 if (em->block_start == EXTENT_MAP_HOLE ||
2243 (cur_offset >= inode->i_size &&
2244 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
2245 ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
2246 last_byte - cur_offset,
2247 1 << inode->i_blkbits,
2248 offset + len,
2249 &alloc_hint);
2250
2251 if (ret < 0) {
2252 free_extent_map(em);
2253 break;
2254 }
2255 } else if (actual_end > inode->i_size &&
2256 !(mode & FALLOC_FL_KEEP_SIZE)) {
2257 /*
2258 * We didn't need to allocate any more space, but we
2259 * still extended the size of the file so we need to
2260 * update i_size.
2261 */
2262 inode->i_ctime = CURRENT_TIME;
2263 i_size_write(inode, actual_end);
2264 btrfs_ordered_update_i_size(inode, actual_end, NULL);
2265 }
2266 free_extent_map(em);
2267
2268 cur_offset = last_byte;
2269 if (cur_offset >= alloc_end) {
2270 ret = 0;
2271 break;
2272 }
2273 }
2274 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
2275 &cached_state, GFP_NOFS);
2276 out:
2277 mutex_unlock(&inode->i_mutex);
2278 if (root->fs_info->quota_enabled)
2279 btrfs_qgroup_free(root, alloc_end - alloc_start);
2280 out_reserve_fail:
2281 /* Let go of our reservation. */
2282 btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
2283 return ret;
2284 }
2285
2286 static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
2287 {
2288 struct btrfs_root *root = BTRFS_I(inode)->root;
2289 struct extent_map *em;
2290 struct extent_state *cached_state = NULL;
2291 u64 lockstart = *offset;
2292 u64 lockend = i_size_read(inode);
2293 u64 start = *offset;
2294 u64 orig_start = *offset;
2295 u64 len = i_size_read(inode);
2296 u64 last_end = 0;
2297 int ret = 0;
2298
2299 lockend = max_t(u64, root->sectorsize, lockend);
2300 if (lockend <= lockstart)
2301 lockend = lockstart + root->sectorsize;
2302
2303 lockend--;
2304 len = lockend - lockstart + 1;
2305
2306 len = max_t(u64, len, root->sectorsize);
2307 if (inode->i_size == 0)
2308 return -ENXIO;
2309
2310 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0,
2311 &cached_state);
2312
2313 /*
2314 * Delalloc is such a pain. If we have a hole and we have pending
2315 * delalloc for a portion of the hole we will get back a hole that
2316 * exists for the entire range since it hasn't been actually written
2317 * yet. So to take care of this case we need to look for an extent just
2318 * before the position we want in case there is outstanding delalloc
2319 * going on here.
2320 */
2321 if (whence == SEEK_HOLE && start != 0) {
2322 if (start <= root->sectorsize)
2323 em = btrfs_get_extent_fiemap(inode, NULL, 0, 0,
2324 root->sectorsize, 0);
2325 else
2326 em = btrfs_get_extent_fiemap(inode, NULL, 0,
2327 start - root->sectorsize,
2328 root->sectorsize, 0);
2329 if (IS_ERR(em)) {
2330 ret = PTR_ERR(em);
2331 goto out;
2332 }
2333 last_end = em->start + em->len;
2334 if (em->block_start == EXTENT_MAP_DELALLOC)
2335 last_end = min_t(u64, last_end, inode->i_size);
2336 free_extent_map(em);
2337 }
2338
2339 while (1) {
2340 em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
2341 if (IS_ERR(em)) {
2342 ret = PTR_ERR(em);
2343 break;
2344 }
2345
2346 if (em->block_start == EXTENT_MAP_HOLE) {
2347 if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
2348 if (last_end <= orig_start) {
2349 free_extent_map(em);
2350 ret = -ENXIO;
2351 break;
2352 }
2353 }
2354
2355 if (whence == SEEK_HOLE) {
2356 *offset = start;
2357 free_extent_map(em);
2358 break;
2359 }
2360 } else {
2361 if (whence == SEEK_DATA) {
2362 if (em->block_start == EXTENT_MAP_DELALLOC) {
2363 if (start >= inode->i_size) {
2364 free_extent_map(em);
2365 ret = -ENXIO;
2366 break;
2367 }
2368 }
2369
2370 if (!test_bit(EXTENT_FLAG_PREALLOC,
2371 &em->flags)) {
2372 *offset = start;
2373 free_extent_map(em);
2374 break;
2375 }
2376 }
2377 }
2378
2379 start = em->start + em->len;
2380 last_end = em->start + em->len;
2381
2382 if (em->block_start == EXTENT_MAP_DELALLOC)
2383 last_end = min_t(u64, last_end, inode->i_size);
2384
2385 if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
2386 free_extent_map(em);
2387 ret = -ENXIO;
2388 break;
2389 }
2390 free_extent_map(em);
2391 cond_resched();
2392 }
2393 if (!ret)
2394 *offset = min(*offset, inode->i_size);
2395 out:
2396 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2397 &cached_state, GFP_NOFS);
2398 return ret;
2399 }
2400
2401 static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
2402 {
2403 struct inode *inode = file->f_mapping->host;
2404 int ret;
2405
2406 mutex_lock(&inode->i_mutex);
2407 switch (whence) {
2408 case SEEK_END:
2409 case SEEK_CUR:
2410 offset = generic_file_llseek(file, offset, whence);
2411 goto out;
2412 case SEEK_DATA:
2413 case SEEK_HOLE:
2414 if (offset >= i_size_read(inode)) {
2415 mutex_unlock(&inode->i_mutex);
2416 return -ENXIO;
2417 }
2418
2419 ret = find_desired_extent(inode, &offset, whence);
2420 if (ret) {
2421 mutex_unlock(&inode->i_mutex);
2422 return ret;
2423 }
2424 }
2425
2426 if (offset < 0 && !(file->f_mode & FMODE_UNSIGNED_OFFSET)) {
2427 offset = -EINVAL;
2428 goto out;
2429 }
2430 if (offset > inode->i_sb->s_maxbytes) {
2431 offset = -EINVAL;
2432 goto out;
2433 }
2434
2435 /* Special lock needed here? */
2436 if (offset != file->f_pos) {
2437 file->f_pos = offset;
2438 file->f_version = 0;
2439 }
2440 out:
2441 mutex_unlock(&inode->i_mutex);
2442 return offset;
2443 }
2444
2445 const struct file_operations btrfs_file_operations = {
2446 .llseek = btrfs_file_llseek,
2447 .read = do_sync_read,
2448 .write = do_sync_write,
2449 .aio_read = generic_file_aio_read,
2450 .splice_read = generic_file_splice_read,
2451 .aio_write = btrfs_file_aio_write,
2452 .mmap = btrfs_file_mmap,
2453 .open = generic_file_open,
2454 .release = btrfs_release_file,
2455 .fsync = btrfs_sync_file,
2456 .fallocate = btrfs_fallocate,
2457 .unlocked_ioctl = btrfs_ioctl,
2458 #ifdef CONFIG_COMPAT
2459 .compat_ioctl = btrfs_ioctl,
2460 #endif
2461 };
2462
2463 void btrfs_auto_defrag_exit(void)
2464 {
2465 if (btrfs_inode_defrag_cachep)
2466 kmem_cache_destroy(btrfs_inode_defrag_cachep);
2467 }
2468
2469 int btrfs_auto_defrag_init(void)
2470 {
2471 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
2472 sizeof(struct inode_defrag), 0,
2473 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
2474 NULL);
2475 if (!btrfs_inode_defrag_cachep)
2476 return -ENOMEM;
2477
2478 return 0;
2479 }
kernel source for telekom puls (alcatel/mediatek)