nfsd4: typo logical vs bitwise negate for want_mask
[linux-btrfs-devel.git] / fs / btrfs / ordered-data.c
bloba1c94042530787539350c72e9449c314a8899e9e
1 /*
2 * Copyright (C) 2007 Oracle. All rights reserved.
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.
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.
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.
19 #include <linux/slab.h>
20 #include <linux/blkdev.h>
21 #include <linux/writeback.h>
22 #include <linux/pagevec.h>
23 #include "ctree.h"
24 #include "transaction.h"
25 #include "btrfs_inode.h"
26 #include "extent_io.h"
28 static u64 entry_end(struct btrfs_ordered_extent *entry)
30 if (entry->file_offset + entry->len < entry->file_offset)
31 return (u64)-1;
32 return entry->file_offset + entry->len;
35 /* returns NULL if the insertion worked, or it returns the node it did find
36 * in the tree
38 static struct rb_node *tree_insert(struct rb_root *root, u64 file_offset,
39 struct rb_node *node)
41 struct rb_node **p = &root->rb_node;
42 struct rb_node *parent = NULL;
43 struct btrfs_ordered_extent *entry;
45 while (*p) {
46 parent = *p;
47 entry = rb_entry(parent, struct btrfs_ordered_extent, rb_node);
49 if (file_offset < entry->file_offset)
50 p = &(*p)->rb_left;
51 else if (file_offset >= entry_end(entry))
52 p = &(*p)->rb_right;
53 else
54 return parent;
57 rb_link_node(node, parent, p);
58 rb_insert_color(node, root);
59 return NULL;
63 * look for a given offset in the tree, and if it can't be found return the
64 * first lesser offset
66 static struct rb_node *__tree_search(struct rb_root *root, u64 file_offset,
67 struct rb_node **prev_ret)
69 struct rb_node *n = root->rb_node;
70 struct rb_node *prev = NULL;
71 struct rb_node *test;
72 struct btrfs_ordered_extent *entry;
73 struct btrfs_ordered_extent *prev_entry = NULL;
75 while (n) {
76 entry = rb_entry(n, struct btrfs_ordered_extent, rb_node);
77 prev = n;
78 prev_entry = entry;
80 if (file_offset < entry->file_offset)
81 n = n->rb_left;
82 else if (file_offset >= entry_end(entry))
83 n = n->rb_right;
84 else
85 return n;
87 if (!prev_ret)
88 return NULL;
90 while (prev && file_offset >= entry_end(prev_entry)) {
91 test = rb_next(prev);
92 if (!test)
93 break;
94 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
95 rb_node);
96 if (file_offset < entry_end(prev_entry))
97 break;
99 prev = test;
101 if (prev)
102 prev_entry = rb_entry(prev, struct btrfs_ordered_extent,
103 rb_node);
104 while (prev && file_offset < entry_end(prev_entry)) {
105 test = rb_prev(prev);
106 if (!test)
107 break;
108 prev_entry = rb_entry(test, struct btrfs_ordered_extent,
109 rb_node);
110 prev = test;
112 *prev_ret = prev;
113 return NULL;
117 * helper to check if a given offset is inside a given entry
119 static int offset_in_entry(struct btrfs_ordered_extent *entry, u64 file_offset)
121 if (file_offset < entry->file_offset ||
122 entry->file_offset + entry->len <= file_offset)
123 return 0;
124 return 1;
127 static int range_overlaps(struct btrfs_ordered_extent *entry, u64 file_offset,
128 u64 len)
130 if (file_offset + len <= entry->file_offset ||
131 entry->file_offset + entry->len <= file_offset)
132 return 0;
133 return 1;
137 * look find the first ordered struct that has this offset, otherwise
138 * the first one less than this offset
140 static inline struct rb_node *tree_search(struct btrfs_ordered_inode_tree *tree,
141 u64 file_offset)
143 struct rb_root *root = &tree->tree;
144 struct rb_node *prev = NULL;
145 struct rb_node *ret;
146 struct btrfs_ordered_extent *entry;
148 if (tree->last) {
149 entry = rb_entry(tree->last, struct btrfs_ordered_extent,
150 rb_node);
151 if (offset_in_entry(entry, file_offset))
152 return tree->last;
154 ret = __tree_search(root, file_offset, &prev);
155 if (!ret)
156 ret = prev;
157 if (ret)
158 tree->last = ret;
159 return ret;
162 /* allocate and add a new ordered_extent into the per-inode tree.
163 * file_offset is the logical offset in the file
165 * start is the disk block number of an extent already reserved in the
166 * extent allocation tree
168 * len is the length of the extent
170 * The tree is given a single reference on the ordered extent that was
171 * inserted.
173 static int __btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
174 u64 start, u64 len, u64 disk_len,
175 int type, int dio, int compress_type)
177 struct btrfs_ordered_inode_tree *tree;
178 struct rb_node *node;
179 struct btrfs_ordered_extent *entry;
181 tree = &BTRFS_I(inode)->ordered_tree;
182 entry = kzalloc(sizeof(*entry), GFP_NOFS);
183 if (!entry)
184 return -ENOMEM;
186 entry->file_offset = file_offset;
187 entry->start = start;
188 entry->len = len;
189 entry->disk_len = disk_len;
190 entry->bytes_left = len;
191 entry->inode = inode;
192 entry->compress_type = compress_type;
193 if (type != BTRFS_ORDERED_IO_DONE && type != BTRFS_ORDERED_COMPLETE)
194 set_bit(type, &entry->flags);
196 if (dio)
197 set_bit(BTRFS_ORDERED_DIRECT, &entry->flags);
199 /* one ref for the tree */
200 atomic_set(&entry->refs, 1);
201 init_waitqueue_head(&entry->wait);
202 INIT_LIST_HEAD(&entry->list);
203 INIT_LIST_HEAD(&entry->root_extent_list);
205 trace_btrfs_ordered_extent_add(inode, entry);
207 spin_lock(&tree->lock);
208 node = tree_insert(&tree->tree, file_offset,
209 &entry->rb_node);
210 BUG_ON(node);
211 spin_unlock(&tree->lock);
213 spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
214 list_add_tail(&entry->root_extent_list,
215 &BTRFS_I(inode)->root->fs_info->ordered_extents);
216 spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
218 BUG_ON(node);
219 return 0;
222 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
223 u64 start, u64 len, u64 disk_len, int type)
225 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
226 disk_len, type, 0,
227 BTRFS_COMPRESS_NONE);
230 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
231 u64 start, u64 len, u64 disk_len, int type)
233 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
234 disk_len, type, 1,
235 BTRFS_COMPRESS_NONE);
238 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
239 u64 start, u64 len, u64 disk_len,
240 int type, int compress_type)
242 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
243 disk_len, type, 0,
244 compress_type);
248 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
249 * when an ordered extent is finished. If the list covers more than one
250 * ordered extent, it is split across multiples.
252 int btrfs_add_ordered_sum(struct inode *inode,
253 struct btrfs_ordered_extent *entry,
254 struct btrfs_ordered_sum *sum)
256 struct btrfs_ordered_inode_tree *tree;
258 tree = &BTRFS_I(inode)->ordered_tree;
259 spin_lock(&tree->lock);
260 list_add_tail(&sum->list, &entry->list);
261 spin_unlock(&tree->lock);
262 return 0;
266 * this is used to account for finished IO across a given range
267 * of the file. The IO may span ordered extents. If
268 * a given ordered_extent is completely done, 1 is returned, otherwise
269 * 0.
271 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
272 * to make sure this function only returns 1 once for a given ordered extent.
274 * file_offset is updated to one byte past the range that is recorded as
275 * complete. This allows you to walk forward in the file.
277 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
278 struct btrfs_ordered_extent **cached,
279 u64 *file_offset, u64 io_size)
281 struct btrfs_ordered_inode_tree *tree;
282 struct rb_node *node;
283 struct btrfs_ordered_extent *entry = NULL;
284 int ret;
285 u64 dec_end;
286 u64 dec_start;
287 u64 to_dec;
289 tree = &BTRFS_I(inode)->ordered_tree;
290 spin_lock(&tree->lock);
291 node = tree_search(tree, *file_offset);
292 if (!node) {
293 ret = 1;
294 goto out;
297 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
298 if (!offset_in_entry(entry, *file_offset)) {
299 ret = 1;
300 goto out;
303 dec_start = max(*file_offset, entry->file_offset);
304 dec_end = min(*file_offset + io_size, entry->file_offset +
305 entry->len);
306 *file_offset = dec_end;
307 if (dec_start > dec_end) {
308 printk(KERN_CRIT "bad ordering dec_start %llu end %llu\n",
309 (unsigned long long)dec_start,
310 (unsigned long long)dec_end);
312 to_dec = dec_end - dec_start;
313 if (to_dec > entry->bytes_left) {
314 printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
315 (unsigned long long)entry->bytes_left,
316 (unsigned long long)to_dec);
318 entry->bytes_left -= to_dec;
319 if (entry->bytes_left == 0)
320 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
321 else
322 ret = 1;
323 out:
324 if (!ret && cached && entry) {
325 *cached = entry;
326 atomic_inc(&entry->refs);
328 spin_unlock(&tree->lock);
329 return ret == 0;
333 * this is used to account for finished IO across a given range
334 * of the file. The IO should not span ordered extents. If
335 * a given ordered_extent is completely done, 1 is returned, otherwise
336 * 0.
338 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
339 * to make sure this function only returns 1 once for a given ordered extent.
341 int btrfs_dec_test_ordered_pending(struct inode *inode,
342 struct btrfs_ordered_extent **cached,
343 u64 file_offset, u64 io_size)
345 struct btrfs_ordered_inode_tree *tree;
346 struct rb_node *node;
347 struct btrfs_ordered_extent *entry = NULL;
348 int ret;
350 tree = &BTRFS_I(inode)->ordered_tree;
351 spin_lock(&tree->lock);
352 node = tree_search(tree, file_offset);
353 if (!node) {
354 ret = 1;
355 goto out;
358 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
359 if (!offset_in_entry(entry, file_offset)) {
360 ret = 1;
361 goto out;
364 if (io_size > entry->bytes_left) {
365 printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
366 (unsigned long long)entry->bytes_left,
367 (unsigned long long)io_size);
369 entry->bytes_left -= io_size;
370 if (entry->bytes_left == 0)
371 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
372 else
373 ret = 1;
374 out:
375 if (!ret && cached && entry) {
376 *cached = entry;
377 atomic_inc(&entry->refs);
379 spin_unlock(&tree->lock);
380 return ret == 0;
384 * used to drop a reference on an ordered extent. This will free
385 * the extent if the last reference is dropped
387 int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
389 struct list_head *cur;
390 struct btrfs_ordered_sum *sum;
392 trace_btrfs_ordered_extent_put(entry->inode, entry);
394 if (atomic_dec_and_test(&entry->refs)) {
395 while (!list_empty(&entry->list)) {
396 cur = entry->list.next;
397 sum = list_entry(cur, struct btrfs_ordered_sum, list);
398 list_del(&sum->list);
399 kfree(sum);
401 kfree(entry);
403 return 0;
407 * remove an ordered extent from the tree. No references are dropped
408 * and you must wake_up entry->wait. You must hold the tree lock
409 * while you call this function.
411 static int __btrfs_remove_ordered_extent(struct inode *inode,
412 struct btrfs_ordered_extent *entry)
414 struct btrfs_ordered_inode_tree *tree;
415 struct btrfs_root *root = BTRFS_I(inode)->root;
416 struct rb_node *node;
418 tree = &BTRFS_I(inode)->ordered_tree;
419 node = &entry->rb_node;
420 rb_erase(node, &tree->tree);
421 tree->last = NULL;
422 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
424 spin_lock(&root->fs_info->ordered_extent_lock);
425 list_del_init(&entry->root_extent_list);
427 trace_btrfs_ordered_extent_remove(inode, entry);
430 * we have no more ordered extents for this inode and
431 * no dirty pages. We can safely remove it from the
432 * list of ordered extents
434 if (RB_EMPTY_ROOT(&tree->tree) &&
435 !mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) {
436 list_del_init(&BTRFS_I(inode)->ordered_operations);
438 spin_unlock(&root->fs_info->ordered_extent_lock);
440 return 0;
444 * remove an ordered extent from the tree. No references are dropped
445 * but any waiters are woken.
447 int btrfs_remove_ordered_extent(struct inode *inode,
448 struct btrfs_ordered_extent *entry)
450 struct btrfs_ordered_inode_tree *tree;
451 int ret;
453 tree = &BTRFS_I(inode)->ordered_tree;
454 spin_lock(&tree->lock);
455 ret = __btrfs_remove_ordered_extent(inode, entry);
456 spin_unlock(&tree->lock);
457 wake_up(&entry->wait);
459 return ret;
463 * wait for all the ordered extents in a root. This is done when balancing
464 * space between drives.
466 int btrfs_wait_ordered_extents(struct btrfs_root *root,
467 int nocow_only, int delay_iput)
469 struct list_head splice;
470 struct list_head *cur;
471 struct btrfs_ordered_extent *ordered;
472 struct inode *inode;
474 INIT_LIST_HEAD(&splice);
476 spin_lock(&root->fs_info->ordered_extent_lock);
477 list_splice_init(&root->fs_info->ordered_extents, &splice);
478 while (!list_empty(&splice)) {
479 cur = splice.next;
480 ordered = list_entry(cur, struct btrfs_ordered_extent,
481 root_extent_list);
482 if (nocow_only &&
483 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags) &&
484 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
485 list_move(&ordered->root_extent_list,
486 &root->fs_info->ordered_extents);
487 cond_resched_lock(&root->fs_info->ordered_extent_lock);
488 continue;
491 list_del_init(&ordered->root_extent_list);
492 atomic_inc(&ordered->refs);
495 * the inode may be getting freed (in sys_unlink path).
497 inode = igrab(ordered->inode);
499 spin_unlock(&root->fs_info->ordered_extent_lock);
501 if (inode) {
502 btrfs_start_ordered_extent(inode, ordered, 1);
503 btrfs_put_ordered_extent(ordered);
504 if (delay_iput)
505 btrfs_add_delayed_iput(inode);
506 else
507 iput(inode);
508 } else {
509 btrfs_put_ordered_extent(ordered);
512 spin_lock(&root->fs_info->ordered_extent_lock);
514 spin_unlock(&root->fs_info->ordered_extent_lock);
515 return 0;
519 * this is used during transaction commit to write all the inodes
520 * added to the ordered operation list. These files must be fully on
521 * disk before the transaction commits.
523 * we have two modes here, one is to just start the IO via filemap_flush
524 * and the other is to wait for all the io. When we wait, we have an
525 * extra check to make sure the ordered operation list really is empty
526 * before we return
528 int btrfs_run_ordered_operations(struct btrfs_root *root, int wait)
530 struct btrfs_inode *btrfs_inode;
531 struct inode *inode;
532 struct list_head splice;
534 INIT_LIST_HEAD(&splice);
536 mutex_lock(&root->fs_info->ordered_operations_mutex);
537 spin_lock(&root->fs_info->ordered_extent_lock);
538 again:
539 list_splice_init(&root->fs_info->ordered_operations, &splice);
541 while (!list_empty(&splice)) {
542 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
543 ordered_operations);
545 inode = &btrfs_inode->vfs_inode;
547 list_del_init(&btrfs_inode->ordered_operations);
550 * the inode may be getting freed (in sys_unlink path).
552 inode = igrab(inode);
554 if (!wait && inode) {
555 list_add_tail(&BTRFS_I(inode)->ordered_operations,
556 &root->fs_info->ordered_operations);
558 spin_unlock(&root->fs_info->ordered_extent_lock);
560 if (inode) {
561 if (wait)
562 btrfs_wait_ordered_range(inode, 0, (u64)-1);
563 else
564 filemap_flush(inode->i_mapping);
565 btrfs_add_delayed_iput(inode);
568 cond_resched();
569 spin_lock(&root->fs_info->ordered_extent_lock);
571 if (wait && !list_empty(&root->fs_info->ordered_operations))
572 goto again;
574 spin_unlock(&root->fs_info->ordered_extent_lock);
575 mutex_unlock(&root->fs_info->ordered_operations_mutex);
577 return 0;
581 * Used to start IO or wait for a given ordered extent to finish.
583 * If wait is one, this effectively waits on page writeback for all the pages
584 * in the extent, and it waits on the io completion code to insert
585 * metadata into the btree corresponding to the extent
587 void btrfs_start_ordered_extent(struct inode *inode,
588 struct btrfs_ordered_extent *entry,
589 int wait)
591 u64 start = entry->file_offset;
592 u64 end = start + entry->len - 1;
594 trace_btrfs_ordered_extent_start(inode, entry);
597 * pages in the range can be dirty, clean or writeback. We
598 * start IO on any dirty ones so the wait doesn't stall waiting
599 * for pdflush to find them
601 if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
602 filemap_fdatawrite_range(inode->i_mapping, start, end);
603 if (wait) {
604 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
605 &entry->flags));
610 * Used to wait on ordered extents across a large range of bytes.
612 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
614 u64 end;
615 u64 orig_end;
616 struct btrfs_ordered_extent *ordered;
617 int found;
619 if (start + len < start) {
620 orig_end = INT_LIMIT(loff_t);
621 } else {
622 orig_end = start + len - 1;
623 if (orig_end > INT_LIMIT(loff_t))
624 orig_end = INT_LIMIT(loff_t);
626 again:
627 /* start IO across the range first to instantiate any delalloc
628 * extents
630 filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
632 /* The compression code will leave pages locked but return from
633 * writepage without setting the page writeback. Starting again
634 * with WB_SYNC_ALL will end up waiting for the IO to actually start.
636 filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
638 filemap_fdatawait_range(inode->i_mapping, start, orig_end);
640 end = orig_end;
641 found = 0;
642 while (1) {
643 ordered = btrfs_lookup_first_ordered_extent(inode, end);
644 if (!ordered)
645 break;
646 if (ordered->file_offset > orig_end) {
647 btrfs_put_ordered_extent(ordered);
648 break;
650 if (ordered->file_offset + ordered->len < start) {
651 btrfs_put_ordered_extent(ordered);
652 break;
654 found++;
655 btrfs_start_ordered_extent(inode, ordered, 1);
656 end = ordered->file_offset;
657 btrfs_put_ordered_extent(ordered);
658 if (end == 0 || end == start)
659 break;
660 end--;
662 if (found || test_range_bit(&BTRFS_I(inode)->io_tree, start, orig_end,
663 EXTENT_DELALLOC, 0, NULL)) {
664 schedule_timeout(1);
665 goto again;
667 return 0;
671 * find an ordered extent corresponding to file_offset. return NULL if
672 * nothing is found, otherwise take a reference on the extent and return it
674 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
675 u64 file_offset)
677 struct btrfs_ordered_inode_tree *tree;
678 struct rb_node *node;
679 struct btrfs_ordered_extent *entry = NULL;
681 tree = &BTRFS_I(inode)->ordered_tree;
682 spin_lock(&tree->lock);
683 node = tree_search(tree, file_offset);
684 if (!node)
685 goto out;
687 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
688 if (!offset_in_entry(entry, file_offset))
689 entry = NULL;
690 if (entry)
691 atomic_inc(&entry->refs);
692 out:
693 spin_unlock(&tree->lock);
694 return entry;
697 /* Since the DIO code tries to lock a wide area we need to look for any ordered
698 * extents that exist in the range, rather than just the start of the range.
700 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
701 u64 file_offset,
702 u64 len)
704 struct btrfs_ordered_inode_tree *tree;
705 struct rb_node *node;
706 struct btrfs_ordered_extent *entry = NULL;
708 tree = &BTRFS_I(inode)->ordered_tree;
709 spin_lock(&tree->lock);
710 node = tree_search(tree, file_offset);
711 if (!node) {
712 node = tree_search(tree, file_offset + len);
713 if (!node)
714 goto out;
717 while (1) {
718 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
719 if (range_overlaps(entry, file_offset, len))
720 break;
722 if (entry->file_offset >= file_offset + len) {
723 entry = NULL;
724 break;
726 entry = NULL;
727 node = rb_next(node);
728 if (!node)
729 break;
731 out:
732 if (entry)
733 atomic_inc(&entry->refs);
734 spin_unlock(&tree->lock);
735 return entry;
739 * lookup and return any extent before 'file_offset'. NULL is returned
740 * if none is found
742 struct btrfs_ordered_extent *
743 btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
745 struct btrfs_ordered_inode_tree *tree;
746 struct rb_node *node;
747 struct btrfs_ordered_extent *entry = NULL;
749 tree = &BTRFS_I(inode)->ordered_tree;
750 spin_lock(&tree->lock);
751 node = tree_search(tree, file_offset);
752 if (!node)
753 goto out;
755 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
756 atomic_inc(&entry->refs);
757 out:
758 spin_unlock(&tree->lock);
759 return entry;
763 * After an extent is done, call this to conditionally update the on disk
764 * i_size. i_size is updated to cover any fully written part of the file.
766 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
767 struct btrfs_ordered_extent *ordered)
769 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
770 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
771 u64 disk_i_size;
772 u64 new_i_size;
773 u64 i_size_test;
774 u64 i_size = i_size_read(inode);
775 struct rb_node *node;
776 struct rb_node *prev = NULL;
777 struct btrfs_ordered_extent *test;
778 int ret = 1;
780 if (ordered)
781 offset = entry_end(ordered);
782 else
783 offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
785 spin_lock(&tree->lock);
786 disk_i_size = BTRFS_I(inode)->disk_i_size;
788 /* truncate file */
789 if (disk_i_size > i_size) {
790 BTRFS_I(inode)->disk_i_size = i_size;
791 ret = 0;
792 goto out;
796 * if the disk i_size is already at the inode->i_size, or
797 * this ordered extent is inside the disk i_size, we're done
799 if (disk_i_size == i_size || offset <= disk_i_size) {
800 goto out;
804 * we can't update the disk_isize if there are delalloc bytes
805 * between disk_i_size and this ordered extent
807 if (test_range_bit(io_tree, disk_i_size, offset - 1,
808 EXTENT_DELALLOC, 0, NULL)) {
809 goto out;
812 * walk backward from this ordered extent to disk_i_size.
813 * if we find an ordered extent then we can't update disk i_size
814 * yet
816 if (ordered) {
817 node = rb_prev(&ordered->rb_node);
818 } else {
819 prev = tree_search(tree, offset);
821 * we insert file extents without involving ordered struct,
822 * so there should be no ordered struct cover this offset
824 if (prev) {
825 test = rb_entry(prev, struct btrfs_ordered_extent,
826 rb_node);
827 BUG_ON(offset_in_entry(test, offset));
829 node = prev;
831 while (node) {
832 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
833 if (test->file_offset + test->len <= disk_i_size)
834 break;
835 if (test->file_offset >= i_size)
836 break;
837 if (test->file_offset >= disk_i_size)
838 goto out;
839 node = rb_prev(node);
841 new_i_size = min_t(u64, offset, i_size);
844 * at this point, we know we can safely update i_size to at least
845 * the offset from this ordered extent. But, we need to
846 * walk forward and see if ios from higher up in the file have
847 * finished.
849 if (ordered) {
850 node = rb_next(&ordered->rb_node);
851 } else {
852 if (prev)
853 node = rb_next(prev);
854 else
855 node = rb_first(&tree->tree);
857 i_size_test = 0;
858 if (node) {
860 * do we have an area where IO might have finished
861 * between our ordered extent and the next one.
863 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
864 if (test->file_offset > offset)
865 i_size_test = test->file_offset;
866 } else {
867 i_size_test = i_size;
871 * i_size_test is the end of a region after this ordered
872 * extent where there are no ordered extents. As long as there
873 * are no delalloc bytes in this area, it is safe to update
874 * disk_i_size to the end of the region.
876 if (i_size_test > offset &&
877 !test_range_bit(io_tree, offset, i_size_test - 1,
878 EXTENT_DELALLOC, 0, NULL)) {
879 new_i_size = min_t(u64, i_size_test, i_size);
881 BTRFS_I(inode)->disk_i_size = new_i_size;
882 ret = 0;
883 out:
885 * we need to remove the ordered extent with the tree lock held
886 * so that other people calling this function don't find our fully
887 * processed ordered entry and skip updating the i_size
889 if (ordered)
890 __btrfs_remove_ordered_extent(inode, ordered);
891 spin_unlock(&tree->lock);
892 if (ordered)
893 wake_up(&ordered->wait);
894 return ret;
898 * search the ordered extents for one corresponding to 'offset' and
899 * try to find a checksum. This is used because we allow pages to
900 * be reclaimed before their checksum is actually put into the btree
902 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
903 u32 *sum)
905 struct btrfs_ordered_sum *ordered_sum;
906 struct btrfs_sector_sum *sector_sums;
907 struct btrfs_ordered_extent *ordered;
908 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
909 unsigned long num_sectors;
910 unsigned long i;
911 u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
912 int ret = 1;
914 ordered = btrfs_lookup_ordered_extent(inode, offset);
915 if (!ordered)
916 return 1;
918 spin_lock(&tree->lock);
919 list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
920 if (disk_bytenr >= ordered_sum->bytenr) {
921 num_sectors = ordered_sum->len / sectorsize;
922 sector_sums = ordered_sum->sums;
923 for (i = 0; i < num_sectors; i++) {
924 if (sector_sums[i].bytenr == disk_bytenr) {
925 *sum = sector_sums[i].sum;
926 ret = 0;
927 goto out;
932 out:
933 spin_unlock(&tree->lock);
934 btrfs_put_ordered_extent(ordered);
935 return ret;
940 * add a given inode to the list of inodes that must be fully on
941 * disk before a transaction commit finishes.
943 * This basically gives us the ext3 style data=ordered mode, and it is mostly
944 * used to make sure renamed files are fully on disk.
946 * It is a noop if the inode is already fully on disk.
948 * If trans is not null, we'll do a friendly check for a transaction that
949 * is already flushing things and force the IO down ourselves.
951 int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
952 struct btrfs_root *root,
953 struct inode *inode)
955 u64 last_mod;
957 last_mod = max(BTRFS_I(inode)->generation, BTRFS_I(inode)->last_trans);
960 * if this file hasn't been changed since the last transaction
961 * commit, we can safely return without doing anything
963 if (last_mod < root->fs_info->last_trans_committed)
964 return 0;
967 * the transaction is already committing. Just start the IO and
968 * don't bother with all of this list nonsense
970 if (trans && root->fs_info->running_transaction->blocked) {
971 btrfs_wait_ordered_range(inode, 0, (u64)-1);
972 return 0;
975 spin_lock(&root->fs_info->ordered_extent_lock);
976 if (list_empty(&BTRFS_I(inode)->ordered_operations)) {
977 list_add_tail(&BTRFS_I(inode)->ordered_operations,
978 &root->fs_info->ordered_operations);
980 spin_unlock(&root->fs_info->ordered_extent_lock);
982 return 0;