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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - fs/btrfs/ordered-data.c
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"
29 static u64
entry_end(struct btrfs_ordered_extent
*entry
)
31 if (entry
->file_offset
+ entry
->len
< entry
->file_offset
)
33 return entry
->file_offset
+ entry
->len
;
36 /* returns NULL if the insertion worked, or it returns the node it did find
39 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 file_offset
,
42 struct rb_node
** p
= &root
->rb_node
;
43 struct rb_node
* parent
= NULL
;
44 struct btrfs_ordered_extent
*entry
;
48 entry
= rb_entry(parent
, struct btrfs_ordered_extent
, rb_node
);
50 if (file_offset
< entry
->file_offset
)
52 else if (file_offset
>= entry_end(entry
))
58 rb_link_node(node
, parent
, p
);
59 rb_insert_color(node
, root
);
64 * look for a given offset in the tree, and if it can't be found return the
67 static struct rb_node
*__tree_search(struct rb_root
*root
, u64 file_offset
,
68 struct rb_node
**prev_ret
)
70 struct rb_node
* n
= root
->rb_node
;
71 struct rb_node
*prev
= NULL
;
73 struct btrfs_ordered_extent
*entry
;
74 struct btrfs_ordered_extent
*prev_entry
= NULL
;
77 entry
= rb_entry(n
, struct btrfs_ordered_extent
, rb_node
);
81 if (file_offset
< entry
->file_offset
)
83 else if (file_offset
>= entry_end(entry
))
91 while(prev
&& file_offset
>= entry_end(prev_entry
)) {
95 prev_entry
= rb_entry(test
, struct btrfs_ordered_extent
,
97 if (file_offset
< entry_end(prev_entry
))
103 prev_entry
= rb_entry(prev
, struct btrfs_ordered_extent
,
105 while(prev
&& file_offset
< entry_end(prev_entry
)) {
106 test
= rb_prev(prev
);
109 prev_entry
= rb_entry(test
, struct btrfs_ordered_extent
,
118 * helper to check if a given offset is inside a given entry
120 static int offset_in_entry(struct btrfs_ordered_extent
*entry
, u64 file_offset
)
122 if (file_offset
< entry
->file_offset
||
123 entry
->file_offset
+ entry
->len
<= file_offset
)
129 * look find the first ordered struct that has this offset, otherwise
130 * the first one less than this offset
132 static inline struct rb_node
*tree_search(struct btrfs_ordered_inode_tree
*tree
,
135 struct rb_root
*root
= &tree
->tree
;
136 struct rb_node
*prev
;
138 struct btrfs_ordered_extent
*entry
;
141 entry
= rb_entry(tree
->last
, struct btrfs_ordered_extent
,
143 if (offset_in_entry(entry
, file_offset
))
146 ret
= __tree_search(root
, file_offset
, &prev
);
154 /* allocate and add a new ordered_extent into the per-inode tree.
155 * file_offset is the logical offset in the file
157 * start is the disk block number of an extent already reserved in the
158 * extent allocation tree
160 * len is the length of the extent
162 * This also sets the EXTENT_ORDERED bit on the range in the inode.
164 * The tree is given a single reference on the ordered extent that was
167 int btrfs_add_ordered_extent(struct inode
*inode
, u64 file_offset
,
168 u64 start
, u64 len
, u64 disk_len
, int nocow
,
171 struct btrfs_ordered_inode_tree
*tree
;
172 struct rb_node
*node
;
173 struct btrfs_ordered_extent
*entry
;
175 tree
= &BTRFS_I(inode
)->ordered_tree
;
176 entry
= kzalloc(sizeof(*entry
), GFP_NOFS
);
180 mutex_lock(&tree
->mutex
);
181 entry
->file_offset
= file_offset
;
182 entry
->start
= start
;
184 entry
->disk_len
= disk_len
;
185 entry
->inode
= inode
;
187 set_bit(BTRFS_ORDERED_NOCOW
, &entry
->flags
);
189 set_bit(BTRFS_ORDERED_COMPRESSED
, &entry
->flags
);
191 /* one ref for the tree */
192 atomic_set(&entry
->refs
, 1);
193 init_waitqueue_head(&entry
->wait
);
194 INIT_LIST_HEAD(&entry
->list
);
195 INIT_LIST_HEAD(&entry
->root_extent_list
);
197 node
= tree_insert(&tree
->tree
, file_offset
,
200 printk("warning dup entry from add_ordered_extent\n");
203 set_extent_ordered(&BTRFS_I(inode
)->io_tree
, file_offset
,
204 entry_end(entry
) - 1, GFP_NOFS
);
206 spin_lock(&BTRFS_I(inode
)->root
->fs_info
->ordered_extent_lock
);
207 list_add_tail(&entry
->root_extent_list
,
208 &BTRFS_I(inode
)->root
->fs_info
->ordered_extents
);
209 spin_unlock(&BTRFS_I(inode
)->root
->fs_info
->ordered_extent_lock
);
211 mutex_unlock(&tree
->mutex
);
217 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
218 * when an ordered extent is finished. If the list covers more than one
219 * ordered extent, it is split across multiples.
221 int btrfs_add_ordered_sum(struct inode
*inode
,
222 struct btrfs_ordered_extent
*entry
,
223 struct btrfs_ordered_sum
*sum
)
225 struct btrfs_ordered_inode_tree
*tree
;
227 tree
= &BTRFS_I(inode
)->ordered_tree
;
228 mutex_lock(&tree
->mutex
);
229 list_add_tail(&sum
->list
, &entry
->list
);
230 mutex_unlock(&tree
->mutex
);
235 * this is used to account for finished IO across a given range
236 * of the file. The IO should not span ordered extents. If
237 * a given ordered_extent is completely done, 1 is returned, otherwise
240 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
241 * to make sure this function only returns 1 once for a given ordered extent.
243 int btrfs_dec_test_ordered_pending(struct inode
*inode
,
244 u64 file_offset
, u64 io_size
)
246 struct btrfs_ordered_inode_tree
*tree
;
247 struct rb_node
*node
;
248 struct btrfs_ordered_extent
*entry
;
249 struct extent_io_tree
*io_tree
= &BTRFS_I(inode
)->io_tree
;
252 tree
= &BTRFS_I(inode
)->ordered_tree
;
253 mutex_lock(&tree
->mutex
);
254 clear_extent_ordered(io_tree
, file_offset
, file_offset
+ io_size
- 1,
256 node
= tree_search(tree
, file_offset
);
262 entry
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
263 if (!offset_in_entry(entry
, file_offset
)) {
268 ret
= test_range_bit(io_tree
, entry
->file_offset
,
269 entry
->file_offset
+ entry
->len
- 1,
272 ret
= test_and_set_bit(BTRFS_ORDERED_IO_DONE
, &entry
->flags
);
274 mutex_unlock(&tree
->mutex
);
279 * used to drop a reference on an ordered extent. This will free
280 * the extent if the last reference is dropped
282 int btrfs_put_ordered_extent(struct btrfs_ordered_extent
*entry
)
284 struct list_head
*cur
;
285 struct btrfs_ordered_sum
*sum
;
287 if (atomic_dec_and_test(&entry
->refs
)) {
288 while(!list_empty(&entry
->list
)) {
289 cur
= entry
->list
.next
;
290 sum
= list_entry(cur
, struct btrfs_ordered_sum
, list
);
291 list_del(&sum
->list
);
300 * remove an ordered extent from the tree. No references are dropped
301 * but, anyone waiting on this extent is woken up.
303 int btrfs_remove_ordered_extent(struct inode
*inode
,
304 struct btrfs_ordered_extent
*entry
)
306 struct btrfs_ordered_inode_tree
*tree
;
307 struct rb_node
*node
;
309 tree
= &BTRFS_I(inode
)->ordered_tree
;
310 mutex_lock(&tree
->mutex
);
311 node
= &entry
->rb_node
;
312 rb_erase(node
, &tree
->tree
);
314 set_bit(BTRFS_ORDERED_COMPLETE
, &entry
->flags
);
316 spin_lock(&BTRFS_I(inode
)->root
->fs_info
->ordered_extent_lock
);
317 list_del_init(&entry
->root_extent_list
);
318 spin_unlock(&BTRFS_I(inode
)->root
->fs_info
->ordered_extent_lock
);
320 mutex_unlock(&tree
->mutex
);
321 wake_up(&entry
->wait
);
326 * wait for all the ordered extents in a root. This is done when balancing
327 * space between drives.
329 int btrfs_wait_ordered_extents(struct btrfs_root
*root
, int nocow_only
)
331 struct list_head splice
;
332 struct list_head
*cur
;
333 struct btrfs_ordered_extent
*ordered
;
336 INIT_LIST_HEAD(&splice
);
338 spin_lock(&root
->fs_info
->ordered_extent_lock
);
339 list_splice_init(&root
->fs_info
->ordered_extents
, &splice
);
340 while (!list_empty(&splice
)) {
342 ordered
= list_entry(cur
, struct btrfs_ordered_extent
,
345 !test_bit(BTRFS_ORDERED_NOCOW
, &ordered
->flags
)) {
346 list_move(&ordered
->root_extent_list
,
347 &root
->fs_info
->ordered_extents
);
348 cond_resched_lock(&root
->fs_info
->ordered_extent_lock
);
352 list_del_init(&ordered
->root_extent_list
);
353 atomic_inc(&ordered
->refs
);
356 * the inode may be getting freed (in sys_unlink path).
358 inode
= igrab(ordered
->inode
);
360 spin_unlock(&root
->fs_info
->ordered_extent_lock
);
363 btrfs_start_ordered_extent(inode
, ordered
, 1);
364 btrfs_put_ordered_extent(ordered
);
367 btrfs_put_ordered_extent(ordered
);
370 spin_lock(&root
->fs_info
->ordered_extent_lock
);
372 spin_unlock(&root
->fs_info
->ordered_extent_lock
);
377 * Used to start IO or wait for a given ordered extent to finish.
379 * If wait is one, this effectively waits on page writeback for all the pages
380 * in the extent, and it waits on the io completion code to insert
381 * metadata into the btree corresponding to the extent
383 void btrfs_start_ordered_extent(struct inode
*inode
,
384 struct btrfs_ordered_extent
*entry
,
387 u64 start
= entry
->file_offset
;
388 u64 end
= start
+ entry
->len
- 1;
391 * pages in the range can be dirty, clean or writeback. We
392 * start IO on any dirty ones so the wait doesn't stall waiting
393 * for pdflush to find them
395 btrfs_fdatawrite_range(inode
->i_mapping
, start
, end
, WB_SYNC_NONE
);
397 wait_event(entry
->wait
, test_bit(BTRFS_ORDERED_COMPLETE
,
403 * Used to wait on ordered extents across a large range of bytes.
405 int btrfs_wait_ordered_range(struct inode
*inode
, u64 start
, u64 len
)
410 struct btrfs_ordered_extent
*ordered
;
412 if (start
+ len
< start
) {
413 orig_end
= INT_LIMIT(loff_t
);
415 orig_end
= start
+ len
- 1;
416 if (orig_end
> INT_LIMIT(loff_t
))
417 orig_end
= INT_LIMIT(loff_t
);
421 /* start IO across the range first to instantiate any delalloc
424 btrfs_fdatawrite_range(inode
->i_mapping
, start
, orig_end
, WB_SYNC_NONE
);
426 btrfs_wait_on_page_writeback_range(inode
->i_mapping
,
427 start
>> PAGE_CACHE_SHIFT
,
428 orig_end
>> PAGE_CACHE_SHIFT
);
432 ordered
= btrfs_lookup_first_ordered_extent(inode
, end
);
436 if (ordered
->file_offset
> orig_end
) {
437 btrfs_put_ordered_extent(ordered
);
440 if (ordered
->file_offset
+ ordered
->len
< start
) {
441 btrfs_put_ordered_extent(ordered
);
444 btrfs_start_ordered_extent(inode
, ordered
, 1);
445 end
= ordered
->file_offset
;
446 btrfs_put_ordered_extent(ordered
);
447 if (end
== 0 || end
== start
)
451 if (test_range_bit(&BTRFS_I(inode
)->io_tree
, start
, orig_end
,
452 EXTENT_ORDERED
| EXTENT_DELALLOC
, 0)) {
453 printk("inode %lu still ordered or delalloc after wait "
454 "%llu %llu\n", inode
->i_ino
,
455 (unsigned long long)start
,
456 (unsigned long long)orig_end
);
463 * find an ordered extent corresponding to file_offset. return NULL if
464 * nothing is found, otherwise take a reference on the extent and return it
466 struct btrfs_ordered_extent
*btrfs_lookup_ordered_extent(struct inode
*inode
,
469 struct btrfs_ordered_inode_tree
*tree
;
470 struct rb_node
*node
;
471 struct btrfs_ordered_extent
*entry
= NULL
;
473 tree
= &BTRFS_I(inode
)->ordered_tree
;
474 mutex_lock(&tree
->mutex
);
475 node
= tree_search(tree
, file_offset
);
479 entry
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
480 if (!offset_in_entry(entry
, file_offset
))
483 atomic_inc(&entry
->refs
);
485 mutex_unlock(&tree
->mutex
);
490 * lookup and return any extent before 'file_offset'. NULL is returned
493 struct btrfs_ordered_extent
*
494 btrfs_lookup_first_ordered_extent(struct inode
* inode
, u64 file_offset
)
496 struct btrfs_ordered_inode_tree
*tree
;
497 struct rb_node
*node
;
498 struct btrfs_ordered_extent
*entry
= NULL
;
500 tree
= &BTRFS_I(inode
)->ordered_tree
;
501 mutex_lock(&tree
->mutex
);
502 node
= tree_search(tree
, file_offset
);
506 entry
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
507 atomic_inc(&entry
->refs
);
509 mutex_unlock(&tree
->mutex
);
514 * After an extent is done, call this to conditionally update the on disk
515 * i_size. i_size is updated to cover any fully written part of the file.
517 int btrfs_ordered_update_i_size(struct inode
*inode
,
518 struct btrfs_ordered_extent
*ordered
)
520 struct btrfs_ordered_inode_tree
*tree
= &BTRFS_I(inode
)->ordered_tree
;
521 struct extent_io_tree
*io_tree
= &BTRFS_I(inode
)->io_tree
;
525 struct rb_node
*node
;
526 struct btrfs_ordered_extent
*test
;
528 mutex_lock(&tree
->mutex
);
529 disk_i_size
= BTRFS_I(inode
)->disk_i_size
;
532 * if the disk i_size is already at the inode->i_size, or
533 * this ordered extent is inside the disk i_size, we're done
535 if (disk_i_size
>= inode
->i_size
||
536 ordered
->file_offset
+ ordered
->len
<= disk_i_size
) {
541 * we can't update the disk_isize if there are delalloc bytes
542 * between disk_i_size and this ordered extent
544 if (test_range_bit(io_tree
, disk_i_size
,
545 ordered
->file_offset
+ ordered
->len
- 1,
546 EXTENT_DELALLOC
, 0)) {
550 * walk backward from this ordered extent to disk_i_size.
551 * if we find an ordered extent then we can't update disk i_size
554 node
= &ordered
->rb_node
;
556 node
= rb_prev(node
);
559 test
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
560 if (test
->file_offset
+ test
->len
<= disk_i_size
)
562 if (test
->file_offset
>= inode
->i_size
)
564 if (test
->file_offset
>= disk_i_size
)
567 new_i_size
= min_t(u64
, entry_end(ordered
), i_size_read(inode
));
570 * at this point, we know we can safely update i_size to at least
571 * the offset from this ordered extent. But, we need to
572 * walk forward and see if ios from higher up in the file have
575 node
= rb_next(&ordered
->rb_node
);
579 * do we have an area where IO might have finished
580 * between our ordered extent and the next one.
582 test
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
583 if (test
->file_offset
> entry_end(ordered
)) {
584 i_size_test
= test
->file_offset
;
587 i_size_test
= i_size_read(inode
);
591 * i_size_test is the end of a region after this ordered
592 * extent where there are no ordered extents. As long as there
593 * are no delalloc bytes in this area, it is safe to update
594 * disk_i_size to the end of the region.
596 if (i_size_test
> entry_end(ordered
) &&
597 !test_range_bit(io_tree
, entry_end(ordered
), i_size_test
- 1,
598 EXTENT_DELALLOC
, 0)) {
599 new_i_size
= min_t(u64
, i_size_test
, i_size_read(inode
));
601 BTRFS_I(inode
)->disk_i_size
= new_i_size
;
603 mutex_unlock(&tree
->mutex
);
608 * search the ordered extents for one corresponding to 'offset' and
609 * try to find a checksum. This is used because we allow pages to
610 * be reclaimed before their checksum is actually put into the btree
612 int btrfs_find_ordered_sum(struct inode
*inode
, u64 offset
, u32
*sum
)
614 struct btrfs_ordered_sum
*ordered_sum
;
615 struct btrfs_sector_sum
*sector_sums
;
616 struct btrfs_ordered_extent
*ordered
;
617 struct btrfs_ordered_inode_tree
*tree
= &BTRFS_I(inode
)->ordered_tree
;
618 struct list_head
*cur
;
619 unsigned long num_sectors
;
621 u32 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
624 ordered
= btrfs_lookup_ordered_extent(inode
, offset
);
628 mutex_lock(&tree
->mutex
);
629 list_for_each_prev(cur
, &ordered
->list
) {
630 ordered_sum
= list_entry(cur
, struct btrfs_ordered_sum
, list
);
631 if (offset
>= ordered_sum
->file_offset
) {
632 num_sectors
= ordered_sum
->len
/ sectorsize
;
633 sector_sums
= ordered_sum
->sums
;
634 for (i
= 0; i
< num_sectors
; i
++) {
635 if (sector_sums
[i
].offset
== offset
) {
636 *sum
= sector_sums
[i
].sum
;
644 mutex_unlock(&tree
->mutex
);
645 btrfs_put_ordered_extent(ordered
);
651 * taken from mm/filemap.c because it isn't exported
653 * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range
654 * @mapping: address space structure to write
655 * @start: offset in bytes where the range starts
656 * @end: offset in bytes where the range ends (inclusive)
657 * @sync_mode: enable synchronous operation
659 * Start writeback against all of a mapping's dirty pages that lie
660 * within the byte offsets <start, end> inclusive.
662 * If sync_mode is WB_SYNC_ALL then this is a "data integrity" operation, as
663 * opposed to a regular memory cleansing writeback. The difference between
664 * these two operations is that if a dirty page/buffer is encountered, it must
665 * be waited upon, and not just skipped over.
667 int btrfs_fdatawrite_range(struct address_space
*mapping
, loff_t start
,
668 loff_t end
, int sync_mode
)
670 struct writeback_control wbc
= {
671 .sync_mode
= sync_mode
,
672 .nr_to_write
= mapping
->nrpages
* 2,
673 .range_start
= start
,
677 return btrfs_writepages(mapping
, &wbc
);
681 * taken from mm/filemap.c because it isn't exported
683 * wait_on_page_writeback_range - wait for writeback to complete
684 * @mapping: target address_space
685 * @start: beginning page index
686 * @end: ending page index
688 * Wait for writeback to complete against pages indexed by start->end
691 int btrfs_wait_on_page_writeback_range(struct address_space
*mapping
,
692 pgoff_t start
, pgoff_t end
)
702 pagevec_init(&pvec
, 0);
704 while ((index
<= end
) &&
705 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
706 PAGECACHE_TAG_WRITEBACK
,
707 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1)) != 0) {
710 for (i
= 0; i
< nr_pages
; i
++) {
711 struct page
*page
= pvec
.pages
[i
];
713 /* until radix tree lookup accepts end_index */
714 if (page
->index
> end
)
717 wait_on_page_writeback(page
);
721 pagevec_release(&pvec
);
725 /* Check for outstanding write errors */
726 if (test_and_clear_bit(AS_ENOSPC
, &mapping
->flags
))
728 if (test_and_clear_bit(AS_EIO
, &mapping
->flags
))