arm: ep93xx: Add basic interrupt info
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / btrfs / ordered-data.c
blob083a55477375c7c6b2c83e68fbbb642d4176ae3e
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 spin_lock(&tree->lock);
206 node = tree_insert(&tree->tree, file_offset,
207 &entry->rb_node);
208 BUG_ON(node);
209 spin_unlock(&tree->lock);
211 spin_lock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
212 list_add_tail(&entry->root_extent_list,
213 &BTRFS_I(inode)->root->fs_info->ordered_extents);
214 spin_unlock(&BTRFS_I(inode)->root->fs_info->ordered_extent_lock);
216 BUG_ON(node);
217 return 0;
220 int btrfs_add_ordered_extent(struct inode *inode, u64 file_offset,
221 u64 start, u64 len, u64 disk_len, int type)
223 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
224 disk_len, type, 0,
225 BTRFS_COMPRESS_NONE);
228 int btrfs_add_ordered_extent_dio(struct inode *inode, u64 file_offset,
229 u64 start, u64 len, u64 disk_len, int type)
231 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
232 disk_len, type, 1,
233 BTRFS_COMPRESS_NONE);
236 int btrfs_add_ordered_extent_compress(struct inode *inode, u64 file_offset,
237 u64 start, u64 len, u64 disk_len,
238 int type, int compress_type)
240 return __btrfs_add_ordered_extent(inode, file_offset, start, len,
241 disk_len, type, 0,
242 compress_type);
246 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
247 * when an ordered extent is finished. If the list covers more than one
248 * ordered extent, it is split across multiples.
250 int btrfs_add_ordered_sum(struct inode *inode,
251 struct btrfs_ordered_extent *entry,
252 struct btrfs_ordered_sum *sum)
254 struct btrfs_ordered_inode_tree *tree;
256 tree = &BTRFS_I(inode)->ordered_tree;
257 spin_lock(&tree->lock);
258 list_add_tail(&sum->list, &entry->list);
259 spin_unlock(&tree->lock);
260 return 0;
264 * this is used to account for finished IO across a given range
265 * of the file. The IO may span ordered extents. If
266 * a given ordered_extent is completely done, 1 is returned, otherwise
267 * 0.
269 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
270 * to make sure this function only returns 1 once for a given ordered extent.
272 * file_offset is updated to one byte past the range that is recorded as
273 * complete. This allows you to walk forward in the file.
275 int btrfs_dec_test_first_ordered_pending(struct inode *inode,
276 struct btrfs_ordered_extent **cached,
277 u64 *file_offset, u64 io_size)
279 struct btrfs_ordered_inode_tree *tree;
280 struct rb_node *node;
281 struct btrfs_ordered_extent *entry = NULL;
282 int ret;
283 u64 dec_end;
284 u64 dec_start;
285 u64 to_dec;
287 tree = &BTRFS_I(inode)->ordered_tree;
288 spin_lock(&tree->lock);
289 node = tree_search(tree, *file_offset);
290 if (!node) {
291 ret = 1;
292 goto out;
295 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
296 if (!offset_in_entry(entry, *file_offset)) {
297 ret = 1;
298 goto out;
301 dec_start = max(*file_offset, entry->file_offset);
302 dec_end = min(*file_offset + io_size, entry->file_offset +
303 entry->len);
304 *file_offset = dec_end;
305 if (dec_start > dec_end) {
306 printk(KERN_CRIT "bad ordering dec_start %llu end %llu\n",
307 (unsigned long long)dec_start,
308 (unsigned long long)dec_end);
310 to_dec = dec_end - dec_start;
311 if (to_dec > entry->bytes_left) {
312 printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
313 (unsigned long long)entry->bytes_left,
314 (unsigned long long)to_dec);
316 entry->bytes_left -= to_dec;
317 if (entry->bytes_left == 0)
318 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
319 else
320 ret = 1;
321 out:
322 if (!ret && cached && entry) {
323 *cached = entry;
324 atomic_inc(&entry->refs);
326 spin_unlock(&tree->lock);
327 return ret == 0;
331 * this is used to account for finished IO across a given range
332 * of the file. The IO should not span ordered extents. If
333 * a given ordered_extent is completely done, 1 is returned, otherwise
334 * 0.
336 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
337 * to make sure this function only returns 1 once for a given ordered extent.
339 int btrfs_dec_test_ordered_pending(struct inode *inode,
340 struct btrfs_ordered_extent **cached,
341 u64 file_offset, u64 io_size)
343 struct btrfs_ordered_inode_tree *tree;
344 struct rb_node *node;
345 struct btrfs_ordered_extent *entry = NULL;
346 int ret;
348 tree = &BTRFS_I(inode)->ordered_tree;
349 spin_lock(&tree->lock);
350 node = tree_search(tree, file_offset);
351 if (!node) {
352 ret = 1;
353 goto out;
356 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
357 if (!offset_in_entry(entry, file_offset)) {
358 ret = 1;
359 goto out;
362 if (io_size > entry->bytes_left) {
363 printk(KERN_CRIT "bad ordered accounting left %llu size %llu\n",
364 (unsigned long long)entry->bytes_left,
365 (unsigned long long)io_size);
367 entry->bytes_left -= io_size;
368 if (entry->bytes_left == 0)
369 ret = test_and_set_bit(BTRFS_ORDERED_IO_DONE, &entry->flags);
370 else
371 ret = 1;
372 out:
373 if (!ret && cached && entry) {
374 *cached = entry;
375 atomic_inc(&entry->refs);
377 spin_unlock(&tree->lock);
378 return ret == 0;
382 * used to drop a reference on an ordered extent. This will free
383 * the extent if the last reference is dropped
385 int btrfs_put_ordered_extent(struct btrfs_ordered_extent *entry)
387 struct list_head *cur;
388 struct btrfs_ordered_sum *sum;
390 if (atomic_dec_and_test(&entry->refs)) {
391 while (!list_empty(&entry->list)) {
392 cur = entry->list.next;
393 sum = list_entry(cur, struct btrfs_ordered_sum, list);
394 list_del(&sum->list);
395 kfree(sum);
397 kfree(entry);
399 return 0;
403 * remove an ordered extent from the tree. No references are dropped
404 * and you must wake_up entry->wait. You must hold the tree lock
405 * while you call this function.
407 static int __btrfs_remove_ordered_extent(struct inode *inode,
408 struct btrfs_ordered_extent *entry)
410 struct btrfs_ordered_inode_tree *tree;
411 struct btrfs_root *root = BTRFS_I(inode)->root;
412 struct rb_node *node;
414 tree = &BTRFS_I(inode)->ordered_tree;
415 node = &entry->rb_node;
416 rb_erase(node, &tree->tree);
417 tree->last = NULL;
418 set_bit(BTRFS_ORDERED_COMPLETE, &entry->flags);
420 spin_lock(&root->fs_info->ordered_extent_lock);
421 list_del_init(&entry->root_extent_list);
424 * we have no more ordered extents for this inode and
425 * no dirty pages. We can safely remove it from the
426 * list of ordered extents
428 if (RB_EMPTY_ROOT(&tree->tree) &&
429 !mapping_tagged(inode->i_mapping, PAGECACHE_TAG_DIRTY)) {
430 list_del_init(&BTRFS_I(inode)->ordered_operations);
432 spin_unlock(&root->fs_info->ordered_extent_lock);
434 return 0;
438 * remove an ordered extent from the tree. No references are dropped
439 * but any waiters are woken.
441 int btrfs_remove_ordered_extent(struct inode *inode,
442 struct btrfs_ordered_extent *entry)
444 struct btrfs_ordered_inode_tree *tree;
445 int ret;
447 tree = &BTRFS_I(inode)->ordered_tree;
448 spin_lock(&tree->lock);
449 ret = __btrfs_remove_ordered_extent(inode, entry);
450 spin_unlock(&tree->lock);
451 wake_up(&entry->wait);
453 return ret;
457 * wait for all the ordered extents in a root. This is done when balancing
458 * space between drives.
460 int btrfs_wait_ordered_extents(struct btrfs_root *root,
461 int nocow_only, int delay_iput)
463 struct list_head splice;
464 struct list_head *cur;
465 struct btrfs_ordered_extent *ordered;
466 struct inode *inode;
468 INIT_LIST_HEAD(&splice);
470 spin_lock(&root->fs_info->ordered_extent_lock);
471 list_splice_init(&root->fs_info->ordered_extents, &splice);
472 while (!list_empty(&splice)) {
473 cur = splice.next;
474 ordered = list_entry(cur, struct btrfs_ordered_extent,
475 root_extent_list);
476 if (nocow_only &&
477 !test_bit(BTRFS_ORDERED_NOCOW, &ordered->flags) &&
478 !test_bit(BTRFS_ORDERED_PREALLOC, &ordered->flags)) {
479 list_move(&ordered->root_extent_list,
480 &root->fs_info->ordered_extents);
481 cond_resched_lock(&root->fs_info->ordered_extent_lock);
482 continue;
485 list_del_init(&ordered->root_extent_list);
486 atomic_inc(&ordered->refs);
489 * the inode may be getting freed (in sys_unlink path).
491 inode = igrab(ordered->inode);
493 spin_unlock(&root->fs_info->ordered_extent_lock);
495 if (inode) {
496 btrfs_start_ordered_extent(inode, ordered, 1);
497 btrfs_put_ordered_extent(ordered);
498 if (delay_iput)
499 btrfs_add_delayed_iput(inode);
500 else
501 iput(inode);
502 } else {
503 btrfs_put_ordered_extent(ordered);
506 spin_lock(&root->fs_info->ordered_extent_lock);
508 spin_unlock(&root->fs_info->ordered_extent_lock);
509 return 0;
513 * this is used during transaction commit to write all the inodes
514 * added to the ordered operation list. These files must be fully on
515 * disk before the transaction commits.
517 * we have two modes here, one is to just start the IO via filemap_flush
518 * and the other is to wait for all the io. When we wait, we have an
519 * extra check to make sure the ordered operation list really is empty
520 * before we return
522 int btrfs_run_ordered_operations(struct btrfs_root *root, int wait)
524 struct btrfs_inode *btrfs_inode;
525 struct inode *inode;
526 struct list_head splice;
528 INIT_LIST_HEAD(&splice);
530 mutex_lock(&root->fs_info->ordered_operations_mutex);
531 spin_lock(&root->fs_info->ordered_extent_lock);
532 again:
533 list_splice_init(&root->fs_info->ordered_operations, &splice);
535 while (!list_empty(&splice)) {
536 btrfs_inode = list_entry(splice.next, struct btrfs_inode,
537 ordered_operations);
539 inode = &btrfs_inode->vfs_inode;
541 list_del_init(&btrfs_inode->ordered_operations);
544 * the inode may be getting freed (in sys_unlink path).
546 inode = igrab(inode);
548 if (!wait && inode) {
549 list_add_tail(&BTRFS_I(inode)->ordered_operations,
550 &root->fs_info->ordered_operations);
552 spin_unlock(&root->fs_info->ordered_extent_lock);
554 if (inode) {
555 if (wait)
556 btrfs_wait_ordered_range(inode, 0, (u64)-1);
557 else
558 filemap_flush(inode->i_mapping);
559 btrfs_add_delayed_iput(inode);
562 cond_resched();
563 spin_lock(&root->fs_info->ordered_extent_lock);
565 if (wait && !list_empty(&root->fs_info->ordered_operations))
566 goto again;
568 spin_unlock(&root->fs_info->ordered_extent_lock);
569 mutex_unlock(&root->fs_info->ordered_operations_mutex);
571 return 0;
575 * Used to start IO or wait for a given ordered extent to finish.
577 * If wait is one, this effectively waits on page writeback for all the pages
578 * in the extent, and it waits on the io completion code to insert
579 * metadata into the btree corresponding to the extent
581 void btrfs_start_ordered_extent(struct inode *inode,
582 struct btrfs_ordered_extent *entry,
583 int wait)
585 u64 start = entry->file_offset;
586 u64 end = start + entry->len - 1;
589 * pages in the range can be dirty, clean or writeback. We
590 * start IO on any dirty ones so the wait doesn't stall waiting
591 * for pdflush to find them
593 if (!test_bit(BTRFS_ORDERED_DIRECT, &entry->flags))
594 filemap_fdatawrite_range(inode->i_mapping, start, end);
595 if (wait) {
596 wait_event(entry->wait, test_bit(BTRFS_ORDERED_COMPLETE,
597 &entry->flags));
602 * Used to wait on ordered extents across a large range of bytes.
604 int btrfs_wait_ordered_range(struct inode *inode, u64 start, u64 len)
606 u64 end;
607 u64 orig_end;
608 struct btrfs_ordered_extent *ordered;
609 int found;
611 if (start + len < start) {
612 orig_end = INT_LIMIT(loff_t);
613 } else {
614 orig_end = start + len - 1;
615 if (orig_end > INT_LIMIT(loff_t))
616 orig_end = INT_LIMIT(loff_t);
618 again:
619 /* start IO across the range first to instantiate any delalloc
620 * extents
622 filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
624 /* The compression code will leave pages locked but return from
625 * writepage without setting the page writeback. Starting again
626 * with WB_SYNC_ALL will end up waiting for the IO to actually start.
628 filemap_fdatawrite_range(inode->i_mapping, start, orig_end);
630 filemap_fdatawait_range(inode->i_mapping, start, orig_end);
632 end = orig_end;
633 found = 0;
634 while (1) {
635 ordered = btrfs_lookup_first_ordered_extent(inode, end);
636 if (!ordered)
637 break;
638 if (ordered->file_offset > orig_end) {
639 btrfs_put_ordered_extent(ordered);
640 break;
642 if (ordered->file_offset + ordered->len < start) {
643 btrfs_put_ordered_extent(ordered);
644 break;
646 found++;
647 btrfs_start_ordered_extent(inode, ordered, 1);
648 end = ordered->file_offset;
649 btrfs_put_ordered_extent(ordered);
650 if (end == 0 || end == start)
651 break;
652 end--;
654 if (found || test_range_bit(&BTRFS_I(inode)->io_tree, start, orig_end,
655 EXTENT_DELALLOC, 0, NULL)) {
656 schedule_timeout(1);
657 goto again;
659 return 0;
663 * find an ordered extent corresponding to file_offset. return NULL if
664 * nothing is found, otherwise take a reference on the extent and return it
666 struct btrfs_ordered_extent *btrfs_lookup_ordered_extent(struct inode *inode,
667 u64 file_offset)
669 struct btrfs_ordered_inode_tree *tree;
670 struct rb_node *node;
671 struct btrfs_ordered_extent *entry = NULL;
673 tree = &BTRFS_I(inode)->ordered_tree;
674 spin_lock(&tree->lock);
675 node = tree_search(tree, file_offset);
676 if (!node)
677 goto out;
679 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
680 if (!offset_in_entry(entry, file_offset))
681 entry = NULL;
682 if (entry)
683 atomic_inc(&entry->refs);
684 out:
685 spin_unlock(&tree->lock);
686 return entry;
689 /* Since the DIO code tries to lock a wide area we need to look for any ordered
690 * extents that exist in the range, rather than just the start of the range.
692 struct btrfs_ordered_extent *btrfs_lookup_ordered_range(struct inode *inode,
693 u64 file_offset,
694 u64 len)
696 struct btrfs_ordered_inode_tree *tree;
697 struct rb_node *node;
698 struct btrfs_ordered_extent *entry = NULL;
700 tree = &BTRFS_I(inode)->ordered_tree;
701 spin_lock(&tree->lock);
702 node = tree_search(tree, file_offset);
703 if (!node) {
704 node = tree_search(tree, file_offset + len);
705 if (!node)
706 goto out;
709 while (1) {
710 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
711 if (range_overlaps(entry, file_offset, len))
712 break;
714 if (entry->file_offset >= file_offset + len) {
715 entry = NULL;
716 break;
718 entry = NULL;
719 node = rb_next(node);
720 if (!node)
721 break;
723 out:
724 if (entry)
725 atomic_inc(&entry->refs);
726 spin_unlock(&tree->lock);
727 return entry;
731 * lookup and return any extent before 'file_offset'. NULL is returned
732 * if none is found
734 struct btrfs_ordered_extent *
735 btrfs_lookup_first_ordered_extent(struct inode *inode, u64 file_offset)
737 struct btrfs_ordered_inode_tree *tree;
738 struct rb_node *node;
739 struct btrfs_ordered_extent *entry = NULL;
741 tree = &BTRFS_I(inode)->ordered_tree;
742 spin_lock(&tree->lock);
743 node = tree_search(tree, file_offset);
744 if (!node)
745 goto out;
747 entry = rb_entry(node, struct btrfs_ordered_extent, rb_node);
748 atomic_inc(&entry->refs);
749 out:
750 spin_unlock(&tree->lock);
751 return entry;
755 * After an extent is done, call this to conditionally update the on disk
756 * i_size. i_size is updated to cover any fully written part of the file.
758 int btrfs_ordered_update_i_size(struct inode *inode, u64 offset,
759 struct btrfs_ordered_extent *ordered)
761 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
762 struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree;
763 u64 disk_i_size;
764 u64 new_i_size;
765 u64 i_size_test;
766 u64 i_size = i_size_read(inode);
767 struct rb_node *node;
768 struct rb_node *prev = NULL;
769 struct btrfs_ordered_extent *test;
770 int ret = 1;
772 if (ordered)
773 offset = entry_end(ordered);
774 else
775 offset = ALIGN(offset, BTRFS_I(inode)->root->sectorsize);
777 spin_lock(&tree->lock);
778 disk_i_size = BTRFS_I(inode)->disk_i_size;
780 /* truncate file */
781 if (disk_i_size > i_size) {
782 BTRFS_I(inode)->disk_i_size = i_size;
783 ret = 0;
784 goto out;
788 * if the disk i_size is already at the inode->i_size, or
789 * this ordered extent is inside the disk i_size, we're done
791 if (disk_i_size == i_size || offset <= disk_i_size) {
792 goto out;
796 * we can't update the disk_isize if there are delalloc bytes
797 * between disk_i_size and this ordered extent
799 if (test_range_bit(io_tree, disk_i_size, offset - 1,
800 EXTENT_DELALLOC, 0, NULL)) {
801 goto out;
804 * walk backward from this ordered extent to disk_i_size.
805 * if we find an ordered extent then we can't update disk i_size
806 * yet
808 if (ordered) {
809 node = rb_prev(&ordered->rb_node);
810 } else {
811 prev = tree_search(tree, offset);
813 * we insert file extents without involving ordered struct,
814 * so there should be no ordered struct cover this offset
816 if (prev) {
817 test = rb_entry(prev, struct btrfs_ordered_extent,
818 rb_node);
819 BUG_ON(offset_in_entry(test, offset));
821 node = prev;
823 while (node) {
824 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
825 if (test->file_offset + test->len <= disk_i_size)
826 break;
827 if (test->file_offset >= i_size)
828 break;
829 if (test->file_offset >= disk_i_size)
830 goto out;
831 node = rb_prev(node);
833 new_i_size = min_t(u64, offset, i_size);
836 * at this point, we know we can safely update i_size to at least
837 * the offset from this ordered extent. But, we need to
838 * walk forward and see if ios from higher up in the file have
839 * finished.
841 if (ordered) {
842 node = rb_next(&ordered->rb_node);
843 } else {
844 if (prev)
845 node = rb_next(prev);
846 else
847 node = rb_first(&tree->tree);
849 i_size_test = 0;
850 if (node) {
852 * do we have an area where IO might have finished
853 * between our ordered extent and the next one.
855 test = rb_entry(node, struct btrfs_ordered_extent, rb_node);
856 if (test->file_offset > offset)
857 i_size_test = test->file_offset;
858 } else {
859 i_size_test = i_size;
863 * i_size_test is the end of a region after this ordered
864 * extent where there are no ordered extents. As long as there
865 * are no delalloc bytes in this area, it is safe to update
866 * disk_i_size to the end of the region.
868 if (i_size_test > offset &&
869 !test_range_bit(io_tree, offset, i_size_test - 1,
870 EXTENT_DELALLOC, 0, NULL)) {
871 new_i_size = min_t(u64, i_size_test, i_size);
873 BTRFS_I(inode)->disk_i_size = new_i_size;
874 ret = 0;
875 out:
877 * we need to remove the ordered extent with the tree lock held
878 * so that other people calling this function don't find our fully
879 * processed ordered entry and skip updating the i_size
881 if (ordered)
882 __btrfs_remove_ordered_extent(inode, ordered);
883 spin_unlock(&tree->lock);
884 if (ordered)
885 wake_up(&ordered->wait);
886 return ret;
890 * search the ordered extents for one corresponding to 'offset' and
891 * try to find a checksum. This is used because we allow pages to
892 * be reclaimed before their checksum is actually put into the btree
894 int btrfs_find_ordered_sum(struct inode *inode, u64 offset, u64 disk_bytenr,
895 u32 *sum)
897 struct btrfs_ordered_sum *ordered_sum;
898 struct btrfs_sector_sum *sector_sums;
899 struct btrfs_ordered_extent *ordered;
900 struct btrfs_ordered_inode_tree *tree = &BTRFS_I(inode)->ordered_tree;
901 unsigned long num_sectors;
902 unsigned long i;
903 u32 sectorsize = BTRFS_I(inode)->root->sectorsize;
904 int ret = 1;
906 ordered = btrfs_lookup_ordered_extent(inode, offset);
907 if (!ordered)
908 return 1;
910 spin_lock(&tree->lock);
911 list_for_each_entry_reverse(ordered_sum, &ordered->list, list) {
912 if (disk_bytenr >= ordered_sum->bytenr) {
913 num_sectors = ordered_sum->len / sectorsize;
914 sector_sums = ordered_sum->sums;
915 for (i = 0; i < num_sectors; i++) {
916 if (sector_sums[i].bytenr == disk_bytenr) {
917 *sum = sector_sums[i].sum;
918 ret = 0;
919 goto out;
924 out:
925 spin_unlock(&tree->lock);
926 btrfs_put_ordered_extent(ordered);
927 return ret;
932 * add a given inode to the list of inodes that must be fully on
933 * disk before a transaction commit finishes.
935 * This basically gives us the ext3 style data=ordered mode, and it is mostly
936 * used to make sure renamed files are fully on disk.
938 * It is a noop if the inode is already fully on disk.
940 * If trans is not null, we'll do a friendly check for a transaction that
941 * is already flushing things and force the IO down ourselves.
943 int btrfs_add_ordered_operation(struct btrfs_trans_handle *trans,
944 struct btrfs_root *root,
945 struct inode *inode)
947 u64 last_mod;
949 last_mod = max(BTRFS_I(inode)->generation, BTRFS_I(inode)->last_trans);
952 * if this file hasn't been changed since the last transaction
953 * commit, we can safely return without doing anything
955 if (last_mod < root->fs_info->last_trans_committed)
956 return 0;
959 * the transaction is already committing. Just start the IO and
960 * don't bother with all of this list nonsense
962 if (trans && root->fs_info->running_transaction->blocked) {
963 btrfs_wait_ordered_range(inode, 0, (u64)-1);
964 return 0;
967 spin_lock(&root->fs_info->ordered_extent_lock);
968 if (list_empty(&BTRFS_I(inode)->ordered_operations)) {
969 list_add_tail(&BTRFS_I(inode)->ordered_operations,
970 &root->fs_info->ordered_operations);
972 spin_unlock(&root->fs_info->ordered_extent_lock);
974 return 0;