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/gfp.h>
20 #include <linux/slab.h>
21 #include <linux/blkdev.h>
22 #include <linux/writeback.h>
23 #include <linux/pagevec.h>
25 #include "transaction.h"
26 #include "btrfs_inode.h"
27 #include "extent_io.h"
30 static u64
entry_end(struct btrfs_ordered_extent
*entry
)
32 if (entry
->file_offset
+ entry
->len
< entry
->file_offset
)
34 return entry
->file_offset
+ entry
->len
;
37 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 file_offset
,
40 struct rb_node
** p
= &root
->rb_node
;
41 struct rb_node
* parent
= NULL
;
42 struct btrfs_ordered_extent
*entry
;
46 entry
= rb_entry(parent
, struct btrfs_ordered_extent
, rb_node
);
48 if (file_offset
< entry
->file_offset
)
50 else if (file_offset
>= entry_end(entry
))
56 rb_link_node(node
, parent
, p
);
57 rb_insert_color(node
, root
);
61 static struct rb_node
*__tree_search(struct rb_root
*root
, u64 file_offset
,
62 struct rb_node
**prev_ret
)
64 struct rb_node
* n
= root
->rb_node
;
65 struct rb_node
*prev
= NULL
;
67 struct btrfs_ordered_extent
*entry
;
68 struct btrfs_ordered_extent
*prev_entry
= NULL
;
71 entry
= rb_entry(n
, struct btrfs_ordered_extent
, rb_node
);
75 if (file_offset
< entry
->file_offset
)
77 else if (file_offset
>= entry_end(entry
))
85 while(prev
&& file_offset
>= entry_end(prev_entry
)) {
89 prev_entry
= rb_entry(test
, struct btrfs_ordered_extent
,
91 if (file_offset
< entry_end(prev_entry
))
97 prev_entry
= rb_entry(prev
, struct btrfs_ordered_extent
,
99 while(prev
&& file_offset
< entry_end(prev_entry
)) {
100 test
= rb_prev(prev
);
103 prev_entry
= rb_entry(test
, struct btrfs_ordered_extent
,
111 static int offset_in_entry(struct btrfs_ordered_extent
*entry
, u64 file_offset
)
113 if (file_offset
< entry
->file_offset
||
114 entry
->file_offset
+ entry
->len
<= file_offset
)
119 static inline struct rb_node
*tree_search(struct btrfs_ordered_inode_tree
*tree
,
122 struct rb_root
*root
= &tree
->tree
;
123 struct rb_node
*prev
;
125 struct btrfs_ordered_extent
*entry
;
128 entry
= rb_entry(tree
->last
, struct btrfs_ordered_extent
,
130 if (offset_in_entry(entry
, file_offset
))
133 ret
= __tree_search(root
, file_offset
, &prev
);
141 /* allocate and add a new ordered_extent into the per-inode tree.
142 * file_offset is the logical offset in the file
144 * start is the disk block number of an extent already reserved in the
145 * extent allocation tree
147 * len is the length of the extent
149 * This also sets the EXTENT_ORDERED bit on the range in the inode.
151 * The tree is given a single reference on the ordered extent that was
154 int btrfs_add_ordered_extent(struct inode
*inode
, u64 file_offset
,
155 u64 start
, u64 len
, int nocow
)
157 struct btrfs_ordered_inode_tree
*tree
;
158 struct rb_node
*node
;
159 struct btrfs_ordered_extent
*entry
;
161 tree
= &BTRFS_I(inode
)->ordered_tree
;
162 entry
= kzalloc(sizeof(*entry
), GFP_NOFS
);
166 mutex_lock(&tree
->mutex
);
167 entry
->file_offset
= file_offset
;
168 entry
->start
= start
;
170 entry
->inode
= inode
;
172 set_bit(BTRFS_ORDERED_NOCOW
, &entry
->flags
);
174 /* one ref for the tree */
175 atomic_set(&entry
->refs
, 1);
176 init_waitqueue_head(&entry
->wait
);
177 INIT_LIST_HEAD(&entry
->list
);
178 INIT_LIST_HEAD(&entry
->root_extent_list
);
180 node
= tree_insert(&tree
->tree
, file_offset
,
183 printk("warning dup entry from add_ordered_extent\n");
186 set_extent_ordered(&BTRFS_I(inode
)->io_tree
, file_offset
,
187 entry_end(entry
) - 1, GFP_NOFS
);
189 spin_lock(&BTRFS_I(inode
)->root
->fs_info
->ordered_extent_lock
);
190 list_add_tail(&entry
->root_extent_list
,
191 &BTRFS_I(inode
)->root
->fs_info
->ordered_extents
);
192 spin_unlock(&BTRFS_I(inode
)->root
->fs_info
->ordered_extent_lock
);
194 mutex_unlock(&tree
->mutex
);
200 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
201 * when an ordered extent is finished. If the list covers more than one
202 * ordered extent, it is split across multiples.
204 int btrfs_add_ordered_sum(struct inode
*inode
,
205 struct btrfs_ordered_extent
*entry
,
206 struct btrfs_ordered_sum
*sum
)
208 struct btrfs_ordered_inode_tree
*tree
;
210 tree
= &BTRFS_I(inode
)->ordered_tree
;
211 mutex_lock(&tree
->mutex
);
212 list_add_tail(&sum
->list
, &entry
->list
);
213 mutex_unlock(&tree
->mutex
);
218 * this is used to account for finished IO across a given range
219 * of the file. The IO should not span ordered extents. If
220 * a given ordered_extent is completely done, 1 is returned, otherwise
223 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
224 * to make sure this function only returns 1 once for a given ordered extent.
226 int btrfs_dec_test_ordered_pending(struct inode
*inode
,
227 u64 file_offset
, u64 io_size
)
229 struct btrfs_ordered_inode_tree
*tree
;
230 struct rb_node
*node
;
231 struct btrfs_ordered_extent
*entry
;
232 struct extent_io_tree
*io_tree
= &BTRFS_I(inode
)->io_tree
;
235 tree
= &BTRFS_I(inode
)->ordered_tree
;
236 mutex_lock(&tree
->mutex
);
237 clear_extent_ordered(io_tree
, file_offset
, file_offset
+ io_size
- 1,
239 node
= tree_search(tree
, file_offset
);
245 entry
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
246 if (!offset_in_entry(entry
, file_offset
)) {
251 ret
= test_range_bit(io_tree
, entry
->file_offset
,
252 entry
->file_offset
+ entry
->len
- 1,
255 ret
= test_and_set_bit(BTRFS_ORDERED_IO_DONE
, &entry
->flags
);
257 mutex_unlock(&tree
->mutex
);
262 * used to drop a reference on an ordered extent. This will free
263 * the extent if the last reference is dropped
265 int btrfs_put_ordered_extent(struct btrfs_ordered_extent
*entry
)
267 struct list_head
*cur
;
268 struct btrfs_ordered_sum
*sum
;
270 if (atomic_dec_and_test(&entry
->refs
)) {
271 while(!list_empty(&entry
->list
)) {
272 cur
= entry
->list
.next
;
273 sum
= list_entry(cur
, struct btrfs_ordered_sum
, list
);
274 list_del(&sum
->list
);
283 * remove an ordered extent from the tree. No references are dropped
284 * but, anyone waiting on this extent is woken up.
286 int btrfs_remove_ordered_extent(struct inode
*inode
,
287 struct btrfs_ordered_extent
*entry
)
289 struct btrfs_ordered_inode_tree
*tree
;
290 struct rb_node
*node
;
292 tree
= &BTRFS_I(inode
)->ordered_tree
;
293 mutex_lock(&tree
->mutex
);
294 node
= &entry
->rb_node
;
295 rb_erase(node
, &tree
->tree
);
297 set_bit(BTRFS_ORDERED_COMPLETE
, &entry
->flags
);
299 spin_lock(&BTRFS_I(inode
)->root
->fs_info
->ordered_extent_lock
);
300 list_del_init(&entry
->root_extent_list
);
301 spin_unlock(&BTRFS_I(inode
)->root
->fs_info
->ordered_extent_lock
);
303 mutex_unlock(&tree
->mutex
);
304 wake_up(&entry
->wait
);
308 int btrfs_wait_ordered_extents(struct btrfs_root
*root
, int nocow_only
)
310 struct list_head splice
;
311 struct list_head
*cur
;
312 struct list_head
*tmp
;
313 struct btrfs_ordered_extent
*ordered
;
316 INIT_LIST_HEAD(&splice
);
318 spin_lock(&root
->fs_info
->ordered_extent_lock
);
319 list_splice_init(&root
->fs_info
->ordered_extents
, &splice
);
320 list_for_each_safe(cur
, tmp
, &splice
) {
322 ordered
= list_entry(cur
, struct btrfs_ordered_extent
,
325 !test_bit(BTRFS_ORDERED_NOCOW
, &ordered
->flags
)) {
326 cond_resched_lock(&root
->fs_info
->ordered_extent_lock
);
330 list_del_init(&ordered
->root_extent_list
);
331 atomic_inc(&ordered
->refs
);
332 inode
= ordered
->inode
;
335 * the inode can't go away until all the pages are gone
336 * and the pages won't go away while there is still
337 * an ordered extent and the ordered extent won't go
338 * away until it is off this list. So, we can safely
339 * increment i_count here and call iput later
341 atomic_inc(&inode
->i_count
);
342 spin_unlock(&root
->fs_info
->ordered_extent_lock
);
344 btrfs_start_ordered_extent(inode
, ordered
, 1);
345 btrfs_put_ordered_extent(ordered
);
348 spin_lock(&root
->fs_info
->ordered_extent_lock
);
350 list_splice_init(&splice
, &root
->fs_info
->ordered_extents
);
351 spin_unlock(&root
->fs_info
->ordered_extent_lock
);
356 * Used to start IO or wait for a given ordered extent to finish.
358 * If wait is one, this effectively waits on page writeback for all the pages
359 * in the extent, and it waits on the io completion code to insert
360 * metadata into the btree corresponding to the extent
362 void btrfs_start_ordered_extent(struct inode
*inode
,
363 struct btrfs_ordered_extent
*entry
,
366 u64 start
= entry
->file_offset
;
367 u64 end
= start
+ entry
->len
- 1;
370 * pages in the range can be dirty, clean or writeback. We
371 * start IO on any dirty ones so the wait doesn't stall waiting
372 * for pdflush to find them
374 btrfs_fdatawrite_range(inode
->i_mapping
, start
, end
, WB_SYNC_NONE
);
376 wait_event(entry
->wait
, test_bit(BTRFS_ORDERED_COMPLETE
,
381 * Used to wait on ordered extents across a large range of bytes.
383 void btrfs_wait_ordered_range(struct inode
*inode
, u64 start
, u64 len
)
388 struct btrfs_ordered_extent
*ordered
;
390 if (start
+ len
< start
) {
391 orig_end
= INT_LIMIT(loff_t
);
393 orig_end
= start
+ len
- 1;
394 if (orig_end
> INT_LIMIT(loff_t
))
395 orig_end
= INT_LIMIT(loff_t
);
399 /* start IO across the range first to instantiate any delalloc
402 btrfs_fdatawrite_range(inode
->i_mapping
, start
, orig_end
, WB_SYNC_NONE
);
404 btrfs_wait_on_page_writeback_range(inode
->i_mapping
,
405 start
>> PAGE_CACHE_SHIFT
,
406 orig_end
>> PAGE_CACHE_SHIFT
);
410 ordered
= btrfs_lookup_first_ordered_extent(inode
, end
);
414 if (ordered
->file_offset
> orig_end
) {
415 btrfs_put_ordered_extent(ordered
);
418 if (ordered
->file_offset
+ ordered
->len
< start
) {
419 btrfs_put_ordered_extent(ordered
);
422 btrfs_start_ordered_extent(inode
, ordered
, 1);
423 end
= ordered
->file_offset
;
424 btrfs_put_ordered_extent(ordered
);
425 if (end
== 0 || end
== start
)
429 if (test_range_bit(&BTRFS_I(inode
)->io_tree
, start
, orig_end
,
430 EXTENT_ORDERED
| EXTENT_DELALLOC
, 0)) {
431 printk("inode %lu still ordered or delalloc after wait "
432 "%llu %llu\n", inode
->i_ino
,
433 (unsigned long long)start
,
434 (unsigned long long)orig_end
);
440 * find an ordered extent corresponding to file_offset. return NULL if
441 * nothing is found, otherwise take a reference on the extent and return it
443 struct btrfs_ordered_extent
*btrfs_lookup_ordered_extent(struct inode
*inode
,
446 struct btrfs_ordered_inode_tree
*tree
;
447 struct rb_node
*node
;
448 struct btrfs_ordered_extent
*entry
= NULL
;
450 tree
= &BTRFS_I(inode
)->ordered_tree
;
451 mutex_lock(&tree
->mutex
);
452 node
= tree_search(tree
, file_offset
);
456 entry
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
457 if (!offset_in_entry(entry
, file_offset
))
460 atomic_inc(&entry
->refs
);
462 mutex_unlock(&tree
->mutex
);
467 * lookup and return any extent before 'file_offset'. NULL is returned
470 struct btrfs_ordered_extent
*
471 btrfs_lookup_first_ordered_extent(struct inode
* inode
, u64 file_offset
)
473 struct btrfs_ordered_inode_tree
*tree
;
474 struct rb_node
*node
;
475 struct btrfs_ordered_extent
*entry
= NULL
;
477 tree
= &BTRFS_I(inode
)->ordered_tree
;
478 mutex_lock(&tree
->mutex
);
479 node
= tree_search(tree
, file_offset
);
483 entry
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
484 atomic_inc(&entry
->refs
);
486 mutex_unlock(&tree
->mutex
);
491 * After an extent is done, call this to conditionally update the on disk
492 * i_size. i_size is updated to cover any fully written part of the file.
494 int btrfs_ordered_update_i_size(struct inode
*inode
,
495 struct btrfs_ordered_extent
*ordered
)
497 struct btrfs_ordered_inode_tree
*tree
= &BTRFS_I(inode
)->ordered_tree
;
498 struct extent_io_tree
*io_tree
= &BTRFS_I(inode
)->io_tree
;
502 struct rb_node
*node
;
503 struct btrfs_ordered_extent
*test
;
505 mutex_lock(&tree
->mutex
);
506 disk_i_size
= BTRFS_I(inode
)->disk_i_size
;
509 * if the disk i_size is already at the inode->i_size, or
510 * this ordered extent is inside the disk i_size, we're done
512 if (disk_i_size
>= inode
->i_size
||
513 ordered
->file_offset
+ ordered
->len
<= disk_i_size
) {
518 * we can't update the disk_isize if there are delalloc bytes
519 * between disk_i_size and this ordered extent
521 if (test_range_bit(io_tree
, disk_i_size
,
522 ordered
->file_offset
+ ordered
->len
- 1,
523 EXTENT_DELALLOC
, 0)) {
527 * walk backward from this ordered extent to disk_i_size.
528 * if we find an ordered extent then we can't update disk i_size
531 node
= &ordered
->rb_node
;
533 node
= rb_prev(node
);
536 test
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
537 if (test
->file_offset
+ test
->len
<= disk_i_size
)
539 if (test
->file_offset
>= inode
->i_size
)
541 if (test
->file_offset
>= disk_i_size
)
544 new_i_size
= min_t(u64
, entry_end(ordered
), i_size_read(inode
));
547 * at this point, we know we can safely update i_size to at least
548 * the offset from this ordered extent. But, we need to
549 * walk forward and see if ios from higher up in the file have
552 node
= rb_next(&ordered
->rb_node
);
556 * do we have an area where IO might have finished
557 * between our ordered extent and the next one.
559 test
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
560 if (test
->file_offset
> entry_end(ordered
)) {
561 i_size_test
= test
->file_offset
;
564 i_size_test
= i_size_read(inode
);
568 * i_size_test is the end of a region after this ordered
569 * extent where there are no ordered extents. As long as there
570 * are no delalloc bytes in this area, it is safe to update
571 * disk_i_size to the end of the region.
573 if (i_size_test
> entry_end(ordered
) &&
574 !test_range_bit(io_tree
, entry_end(ordered
), i_size_test
- 1,
575 EXTENT_DELALLOC
, 0)) {
576 new_i_size
= min_t(u64
, i_size_test
, i_size_read(inode
));
578 BTRFS_I(inode
)->disk_i_size
= new_i_size
;
580 mutex_unlock(&tree
->mutex
);
585 * search the ordered extents for one corresponding to 'offset' and
586 * try to find a checksum. This is used because we allow pages to
587 * be reclaimed before their checksum is actually put into the btree
589 int btrfs_find_ordered_sum(struct inode
*inode
, u64 offset
, u32
*sum
)
591 struct btrfs_ordered_sum
*ordered_sum
;
592 struct btrfs_sector_sum
*sector_sums
;
593 struct btrfs_ordered_extent
*ordered
;
594 struct btrfs_ordered_inode_tree
*tree
= &BTRFS_I(inode
)->ordered_tree
;
595 struct list_head
*cur
;
596 unsigned long num_sectors
;
598 u32 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
601 ordered
= btrfs_lookup_ordered_extent(inode
, offset
);
605 mutex_lock(&tree
->mutex
);
606 list_for_each_prev(cur
, &ordered
->list
) {
607 ordered_sum
= list_entry(cur
, struct btrfs_ordered_sum
, list
);
608 if (offset
>= ordered_sum
->file_offset
) {
609 num_sectors
= ordered_sum
->len
/ sectorsize
;
610 sector_sums
= ordered_sum
->sums
;
611 for (i
= 0; i
< num_sectors
; i
++) {
612 if (sector_sums
[i
].offset
== offset
) {
613 *sum
= sector_sums
[i
].sum
;
621 mutex_unlock(&tree
->mutex
);
622 btrfs_put_ordered_extent(ordered
);
628 * taken from mm/filemap.c because it isn't exported
630 * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range
631 * @mapping: address space structure to write
632 * @start: offset in bytes where the range starts
633 * @end: offset in bytes where the range ends (inclusive)
634 * @sync_mode: enable synchronous operation
636 * Start writeback against all of a mapping's dirty pages that lie
637 * within the byte offsets <start, end> inclusive.
639 * If sync_mode is WB_SYNC_ALL then this is a "data integrity" operation, as
640 * opposed to a regular memory cleansing writeback. The difference between
641 * these two operations is that if a dirty page/buffer is encountered, it must
642 * be waited upon, and not just skipped over.
644 int btrfs_fdatawrite_range(struct address_space
*mapping
, loff_t start
,
645 loff_t end
, int sync_mode
)
647 struct writeback_control wbc
= {
648 .sync_mode
= sync_mode
,
649 .nr_to_write
= mapping
->nrpages
* 2,
650 .range_start
= start
,
654 return btrfs_writepages(mapping
, &wbc
);
658 * taken from mm/filemap.c because it isn't exported
660 * wait_on_page_writeback_range - wait for writeback to complete
661 * @mapping: target address_space
662 * @start: beginning page index
663 * @end: ending page index
665 * Wait for writeback to complete against pages indexed by start->end
668 int btrfs_wait_on_page_writeback_range(struct address_space
*mapping
,
669 pgoff_t start
, pgoff_t end
)
679 pagevec_init(&pvec
, 0);
681 while ((index
<= end
) &&
682 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
683 PAGECACHE_TAG_WRITEBACK
,
684 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1)) != 0) {
687 for (i
= 0; i
< nr_pages
; i
++) {
688 struct page
*page
= pvec
.pages
[i
];
690 /* until radix tree lookup accepts end_index */
691 if (page
->index
> end
)
694 wait_on_page_writeback(page
);
698 pagevec_release(&pvec
);
702 /* Check for outstanding write errors */
703 if (test_and_clear_bit(AS_ENOSPC
, &mapping
->flags
))
705 if (test_and_clear_bit(AS_EIO
, &mapping
->flags
))
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