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git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blob - fs/btrfs/ordered-data.c
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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
,
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 /* one ref for the tree */
171 atomic_set(&entry
->refs
, 1);
172 init_waitqueue_head(&entry
->wait
);
173 INIT_LIST_HEAD(&entry
->list
);
175 node
= tree_insert(&tree
->tree
, file_offset
,
178 entry
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
179 atomic_inc(&entry
->refs
);
181 set_extent_ordered(&BTRFS_I(inode
)->io_tree
, file_offset
,
182 entry_end(entry
) - 1, GFP_NOFS
);
184 mutex_unlock(&tree
->mutex
);
190 * Add a struct btrfs_ordered_sum into the list of checksums to be inserted
191 * when an ordered extent is finished. If the list covers more than one
192 * ordered extent, it is split across multiples.
194 int btrfs_add_ordered_sum(struct inode
*inode
,
195 struct btrfs_ordered_extent
*entry
,
196 struct btrfs_ordered_sum
*sum
)
198 struct btrfs_ordered_inode_tree
*tree
;
200 tree
= &BTRFS_I(inode
)->ordered_tree
;
201 mutex_lock(&tree
->mutex
);
202 list_add_tail(&sum
->list
, &entry
->list
);
203 mutex_unlock(&tree
->mutex
);
208 * this is used to account for finished IO across a given range
209 * of the file. The IO should not span ordered extents. If
210 * a given ordered_extent is completely done, 1 is returned, otherwise
213 * test_and_set_bit on a flag in the struct btrfs_ordered_extent is used
214 * to make sure this function only returns 1 once for a given ordered extent.
216 int btrfs_dec_test_ordered_pending(struct inode
*inode
,
217 u64 file_offset
, u64 io_size
)
219 struct btrfs_ordered_inode_tree
*tree
;
220 struct rb_node
*node
;
221 struct btrfs_ordered_extent
*entry
;
222 struct extent_io_tree
*io_tree
= &BTRFS_I(inode
)->io_tree
;
225 tree
= &BTRFS_I(inode
)->ordered_tree
;
226 mutex_lock(&tree
->mutex
);
227 clear_extent_ordered(io_tree
, file_offset
, file_offset
+ io_size
- 1,
229 node
= tree_search(tree
, file_offset
);
235 entry
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
236 if (!offset_in_entry(entry
, file_offset
)) {
241 ret
= test_range_bit(io_tree
, entry
->file_offset
,
242 entry
->file_offset
+ entry
->len
- 1,
245 ret
= test_and_set_bit(BTRFS_ORDERED_IO_DONE
, &entry
->flags
);
247 mutex_unlock(&tree
->mutex
);
252 * used to drop a reference on an ordered extent. This will free
253 * the extent if the last reference is dropped
255 int btrfs_put_ordered_extent(struct btrfs_ordered_extent
*entry
)
257 struct list_head
*cur
;
258 struct btrfs_ordered_sum
*sum
;
260 if (atomic_dec_and_test(&entry
->refs
)) {
261 while(!list_empty(&entry
->list
)) {
262 cur
= entry
->list
.next
;
263 sum
= list_entry(cur
, struct btrfs_ordered_sum
, list
);
264 list_del(&sum
->list
);
273 * remove an ordered extent from the tree. No references are dropped
274 * but, anyone waiting on this extent is woken up.
276 int btrfs_remove_ordered_extent(struct inode
*inode
,
277 struct btrfs_ordered_extent
*entry
)
279 struct btrfs_ordered_inode_tree
*tree
;
280 struct rb_node
*node
;
282 tree
= &BTRFS_I(inode
)->ordered_tree
;
283 mutex_lock(&tree
->mutex
);
284 node
= &entry
->rb_node
;
285 rb_erase(node
, &tree
->tree
);
287 set_bit(BTRFS_ORDERED_COMPLETE
, &entry
->flags
);
288 mutex_unlock(&tree
->mutex
);
289 wake_up(&entry
->wait
);
294 * Used to start IO or wait for a given ordered extent to finish.
296 * If wait is one, this effectively waits on page writeback for all the pages
297 * in the extent, and it waits on the io completion code to insert
298 * metadata into the btree corresponding to the extent
300 void btrfs_start_ordered_extent(struct inode
*inode
,
301 struct btrfs_ordered_extent
*entry
,
304 u64 start
= entry
->file_offset
;
305 u64 end
= start
+ entry
->len
- 1;
308 * pages in the range can be dirty, clean or writeback. We
309 * start IO on any dirty ones so the wait doesn't stall waiting
310 * for pdflush to find them
312 btrfs_fdatawrite_range(inode
->i_mapping
, start
, end
, WB_SYNC_NONE
);
314 wait_event(entry
->wait
, test_bit(BTRFS_ORDERED_COMPLETE
,
319 * Used to wait on ordered extents across a large range of bytes.
321 void btrfs_wait_ordered_range(struct inode
*inode
, u64 start
, u64 len
)
326 struct btrfs_ordered_extent
*ordered
;
328 if (start
+ len
< start
) {
329 orig_end
= INT_LIMIT(loff_t
);
331 orig_end
= start
+ len
- 1;
332 if (orig_end
> INT_LIMIT(loff_t
))
333 orig_end
= INT_LIMIT(loff_t
);
337 /* start IO across the range first to instantiate any delalloc
340 btrfs_fdatawrite_range(inode
->i_mapping
, start
, orig_end
, WB_SYNC_NONE
);
342 btrfs_wait_on_page_writeback_range(inode
->i_mapping
,
343 start
>> PAGE_CACHE_SHIFT
,
344 orig_end
>> PAGE_CACHE_SHIFT
);
348 ordered
= btrfs_lookup_first_ordered_extent(inode
, end
);
352 if (ordered
->file_offset
> orig_end
) {
353 btrfs_put_ordered_extent(ordered
);
356 if (ordered
->file_offset
+ ordered
->len
< start
) {
357 btrfs_put_ordered_extent(ordered
);
360 btrfs_start_ordered_extent(inode
, ordered
, 1);
361 end
= ordered
->file_offset
;
362 btrfs_put_ordered_extent(ordered
);
363 if (end
== 0 || end
== start
)
367 if (test_range_bit(&BTRFS_I(inode
)->io_tree
, start
, orig_end
,
368 EXTENT_ORDERED
| EXTENT_DELALLOC
, 0)) {
369 printk("inode %lu still ordered or delalloc after wait "
370 "%llu %llu\n", inode
->i_ino
,
371 (unsigned long long)start
,
372 (unsigned long long)orig_end
);
378 * find an ordered extent corresponding to file_offset. return NULL if
379 * nothing is found, otherwise take a reference on the extent and return it
381 struct btrfs_ordered_extent
*btrfs_lookup_ordered_extent(struct inode
*inode
,
384 struct btrfs_ordered_inode_tree
*tree
;
385 struct rb_node
*node
;
386 struct btrfs_ordered_extent
*entry
= NULL
;
388 tree
= &BTRFS_I(inode
)->ordered_tree
;
389 mutex_lock(&tree
->mutex
);
390 node
= tree_search(tree
, file_offset
);
394 entry
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
395 if (!offset_in_entry(entry
, file_offset
))
398 atomic_inc(&entry
->refs
);
400 mutex_unlock(&tree
->mutex
);
405 * lookup and return any extent before 'file_offset'. NULL is returned
408 struct btrfs_ordered_extent
*
409 btrfs_lookup_first_ordered_extent(struct inode
* inode
, u64 file_offset
)
411 struct btrfs_ordered_inode_tree
*tree
;
412 struct rb_node
*node
;
413 struct btrfs_ordered_extent
*entry
= NULL
;
415 tree
= &BTRFS_I(inode
)->ordered_tree
;
416 mutex_lock(&tree
->mutex
);
417 node
= tree_search(tree
, file_offset
);
421 entry
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
422 atomic_inc(&entry
->refs
);
424 mutex_unlock(&tree
->mutex
);
429 * After an extent is done, call this to conditionally update the on disk
430 * i_size. i_size is updated to cover any fully written part of the file.
432 int btrfs_ordered_update_i_size(struct inode
*inode
,
433 struct btrfs_ordered_extent
*ordered
)
435 struct btrfs_ordered_inode_tree
*tree
= &BTRFS_I(inode
)->ordered_tree
;
436 struct extent_io_tree
*io_tree
= &BTRFS_I(inode
)->io_tree
;
440 struct rb_node
*node
;
441 struct btrfs_ordered_extent
*test
;
443 mutex_lock(&tree
->mutex
);
444 disk_i_size
= BTRFS_I(inode
)->disk_i_size
;
447 * if the disk i_size is already at the inode->i_size, or
448 * this ordered extent is inside the disk i_size, we're done
450 if (disk_i_size
>= inode
->i_size
||
451 ordered
->file_offset
+ ordered
->len
<= disk_i_size
) {
456 * we can't update the disk_isize if there are delalloc bytes
457 * between disk_i_size and this ordered extent
459 if (test_range_bit(io_tree
, disk_i_size
,
460 ordered
->file_offset
+ ordered
->len
- 1,
461 EXTENT_DELALLOC
, 0)) {
465 * walk backward from this ordered extent to disk_i_size.
466 * if we find an ordered extent then we can't update disk i_size
469 node
= &ordered
->rb_node
;
471 node
= rb_prev(node
);
474 test
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
475 if (test
->file_offset
+ test
->len
<= disk_i_size
)
477 if (test
->file_offset
>= inode
->i_size
)
479 if (test
->file_offset
>= disk_i_size
)
482 new_i_size
= min_t(u64
, entry_end(ordered
), i_size_read(inode
));
485 * at this point, we know we can safely update i_size to at least
486 * the offset from this ordered extent. But, we need to
487 * walk forward and see if ios from higher up in the file have
490 node
= rb_next(&ordered
->rb_node
);
494 * do we have an area where IO might have finished
495 * between our ordered extent and the next one.
497 test
= rb_entry(node
, struct btrfs_ordered_extent
, rb_node
);
498 if (test
->file_offset
> entry_end(ordered
)) {
499 i_size_test
= test
->file_offset
- 1;
502 i_size_test
= i_size_read(inode
);
506 * i_size_test is the end of a region after this ordered
507 * extent where there are no ordered extents. As long as there
508 * are no delalloc bytes in this area, it is safe to update
509 * disk_i_size to the end of the region.
511 if (i_size_test
> entry_end(ordered
) &&
512 !test_range_bit(io_tree
, entry_end(ordered
), i_size_test
,
513 EXTENT_DELALLOC
, 0)) {
514 new_i_size
= min_t(u64
, i_size_test
, i_size_read(inode
));
516 BTRFS_I(inode
)->disk_i_size
= new_i_size
;
518 mutex_unlock(&tree
->mutex
);
523 * search the ordered extents for one corresponding to 'offset' and
524 * try to find a checksum. This is used because we allow pages to
525 * be reclaimed before their checksum is actually put into the btree
527 int btrfs_find_ordered_sum(struct inode
*inode
, u64 offset
, u32
*sum
)
529 struct btrfs_ordered_sum
*ordered_sum
;
530 struct btrfs_sector_sum
*sector_sums
;
531 struct btrfs_ordered_extent
*ordered
;
532 struct btrfs_ordered_inode_tree
*tree
= &BTRFS_I(inode
)->ordered_tree
;
533 struct list_head
*cur
;
534 unsigned long num_sectors
;
536 u32 sectorsize
= BTRFS_I(inode
)->root
->sectorsize
;
539 ordered
= btrfs_lookup_ordered_extent(inode
, offset
);
543 mutex_lock(&tree
->mutex
);
544 list_for_each_prev(cur
, &ordered
->list
) {
545 ordered_sum
= list_entry(cur
, struct btrfs_ordered_sum
, list
);
546 if (offset
>= ordered_sum
->file_offset
) {
547 num_sectors
= ordered_sum
->len
/ sectorsize
;
548 sector_sums
= ordered_sum
->sums
;
549 for (i
= 0; i
< num_sectors
; i
++) {
550 if (sector_sums
[i
].offset
== offset
) {
551 *sum
= sector_sums
[i
].sum
;
559 mutex_unlock(&tree
->mutex
);
560 btrfs_put_ordered_extent(ordered
);
566 * taken from mm/filemap.c because it isn't exported
568 * __filemap_fdatawrite_range - start writeback on mapping dirty pages in range
569 * @mapping: address space structure to write
570 * @start: offset in bytes where the range starts
571 * @end: offset in bytes where the range ends (inclusive)
572 * @sync_mode: enable synchronous operation
574 * Start writeback against all of a mapping's dirty pages that lie
575 * within the byte offsets <start, end> inclusive.
577 * If sync_mode is WB_SYNC_ALL then this is a "data integrity" operation, as
578 * opposed to a regular memory cleansing writeback. The difference between
579 * these two operations is that if a dirty page/buffer is encountered, it must
580 * be waited upon, and not just skipped over.
582 int btrfs_fdatawrite_range(struct address_space
*mapping
, loff_t start
,
583 loff_t end
, int sync_mode
)
585 struct writeback_control wbc
= {
586 .sync_mode
= sync_mode
,
587 .nr_to_write
= mapping
->nrpages
* 2,
588 .range_start
= start
,
592 return btrfs_writepages(mapping
, &wbc
);
596 * taken from mm/filemap.c because it isn't exported
598 * wait_on_page_writeback_range - wait for writeback to complete
599 * @mapping: target address_space
600 * @start: beginning page index
601 * @end: ending page index
603 * Wait for writeback to complete against pages indexed by start->end
606 int btrfs_wait_on_page_writeback_range(struct address_space
*mapping
,
607 pgoff_t start
, pgoff_t end
)
617 pagevec_init(&pvec
, 0);
619 while ((index
<= end
) &&
620 (nr_pages
= pagevec_lookup_tag(&pvec
, mapping
, &index
,
621 PAGECACHE_TAG_WRITEBACK
,
622 min(end
- index
, (pgoff_t
)PAGEVEC_SIZE
-1) + 1)) != 0) {
625 for (i
= 0; i
< nr_pages
; i
++) {
626 struct page
*page
= pvec
.pages
[i
];
628 /* until radix tree lookup accepts end_index */
629 if (page
->index
> end
)
632 wait_on_page_writeback(page
);
636 pagevec_release(&pvec
);
640 /* Check for outstanding write errors */
641 if (test_and_clear_bit(AS_ENOSPC
, &mapping
->flags
))
643 if (test_and_clear_bit(AS_EIO
, &mapping
->flags
))