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.
20 #include <linux/pagemap.h>
21 #include <linux/highmem.h>
22 #include <linux/time.h>
23 #include <linux/init.h>
24 #include <linux/string.h>
25 #include <linux/smp_lock.h>
26 #include <linux/backing-dev.h>
27 #include <linux/mpage.h>
28 #include <linux/swap.h>
29 #include <linux/writeback.h>
30 #include <linux/statfs.h>
31 #include <linux/compat.h>
34 #include "transaction.h"
35 #include "btrfs_inode.h"
37 #include "print-tree.h"
43 /* simple helper to fault in pages and copy. This should go away
44 * and be replaced with calls into generic code.
46 static noinline
int btrfs_copy_from_user(loff_t pos
, int num_pages
,
48 struct page
**prepared_pages
,
49 const char __user
*buf
)
53 int offset
= pos
& (PAGE_CACHE_SIZE
- 1);
55 for (i
= 0; i
< num_pages
&& write_bytes
> 0; i
++, offset
= 0) {
56 size_t count
= min_t(size_t,
57 PAGE_CACHE_SIZE
- offset
, write_bytes
);
58 struct page
*page
= prepared_pages
[i
];
59 fault_in_pages_readable(buf
, count
);
61 /* Copy data from userspace to the current page */
63 page_fault
= __copy_from_user(page_address(page
) + offset
,
65 /* Flush processor's dcache for this page */
66 flush_dcache_page(page
);
74 return page_fault
? -EFAULT
: 0;
78 * unlocks pages after btrfs_file_write is done with them
80 static noinline
void btrfs_drop_pages(struct page
**pages
, size_t num_pages
)
83 for (i
= 0; i
< num_pages
; i
++) {
86 /* page checked is some magic around finding pages that
87 * have been modified without going through btrfs_set_page_dirty
90 ClearPageChecked(pages
[i
]);
91 unlock_page(pages
[i
]);
92 mark_page_accessed(pages
[i
]);
93 page_cache_release(pages
[i
]);
98 * after copy_from_user, pages need to be dirtied and we need to make
99 * sure holes are created between the current EOF and the start of
100 * any next extents (if required).
102 * this also makes the decision about creating an inline extent vs
103 * doing real data extents, marking pages dirty and delalloc as required.
105 static noinline
int dirty_and_release_pages(struct btrfs_trans_handle
*trans
,
106 struct btrfs_root
*root
,
115 struct inode
*inode
= fdentry(file
)->d_inode
;
116 struct extent_io_tree
*io_tree
= &BTRFS_I(inode
)->io_tree
;
120 u64 end_of_last_block
;
121 u64 end_pos
= pos
+ write_bytes
;
122 loff_t isize
= i_size_read(inode
);
124 start_pos
= pos
& ~((u64
)root
->sectorsize
- 1);
125 num_bytes
= (write_bytes
+ pos
- start_pos
+
126 root
->sectorsize
- 1) & ~((u64
)root
->sectorsize
- 1);
128 end_of_last_block
= start_pos
+ num_bytes
- 1;
130 lock_extent(io_tree
, start_pos
, end_of_last_block
, GFP_NOFS
);
131 trans
= btrfs_join_transaction(root
, 1);
136 btrfs_set_trans_block_group(trans
, inode
);
139 set_extent_uptodate(io_tree
, start_pos
, end_of_last_block
, GFP_NOFS
);
141 /* check for reserved extents on each page, we don't want
142 * to reset the delalloc bit on things that already have
145 btrfs_set_extent_delalloc(inode
, start_pos
, end_of_last_block
);
146 for (i
= 0; i
< num_pages
; i
++) {
147 struct page
*p
= pages
[i
];
152 if (end_pos
> isize
) {
153 i_size_write(inode
, end_pos
);
154 /* we've only changed i_size in ram, and we haven't updated
155 * the disk i_size. There is no need to log the inode
159 err
= btrfs_end_transaction(trans
, root
);
161 unlock_extent(io_tree
, start_pos
, end_of_last_block
, GFP_NOFS
);
166 * this drops all the extents in the cache that intersect the range
167 * [start, end]. Existing extents are split as required.
169 int btrfs_drop_extent_cache(struct inode
*inode
, u64 start
, u64 end
,
172 struct extent_map
*em
;
173 struct extent_map
*split
= NULL
;
174 struct extent_map
*split2
= NULL
;
175 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
176 u64 len
= end
- start
+ 1;
182 WARN_ON(end
< start
);
183 if (end
== (u64
)-1) {
189 split
= alloc_extent_map(GFP_NOFS
);
191 split2
= alloc_extent_map(GFP_NOFS
);
193 spin_lock(&em_tree
->lock
);
194 em
= lookup_extent_mapping(em_tree
, start
, len
);
196 spin_unlock(&em_tree
->lock
);
200 if (skip_pinned
&& test_bit(EXTENT_FLAG_PINNED
, &em
->flags
)) {
201 spin_unlock(&em_tree
->lock
);
202 if (em
->start
<= start
&&
203 (!testend
|| em
->start
+ em
->len
>= start
+ len
)) {
207 if (start
< em
->start
) {
208 len
= em
->start
- start
;
210 len
= start
+ len
- (em
->start
+ em
->len
);
211 start
= em
->start
+ em
->len
;
216 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
217 clear_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
218 remove_extent_mapping(em_tree
, em
);
220 if (em
->block_start
< EXTENT_MAP_LAST_BYTE
&&
222 split
->start
= em
->start
;
223 split
->len
= start
- em
->start
;
224 split
->orig_start
= em
->orig_start
;
225 split
->block_start
= em
->block_start
;
228 split
->block_len
= em
->block_len
;
230 split
->block_len
= split
->len
;
232 split
->bdev
= em
->bdev
;
233 split
->flags
= flags
;
234 ret
= add_extent_mapping(em_tree
, split
);
236 free_extent_map(split
);
240 if (em
->block_start
< EXTENT_MAP_LAST_BYTE
&&
241 testend
&& em
->start
+ em
->len
> start
+ len
) {
242 u64 diff
= start
+ len
- em
->start
;
244 split
->start
= start
+ len
;
245 split
->len
= em
->start
+ em
->len
- (start
+ len
);
246 split
->bdev
= em
->bdev
;
247 split
->flags
= flags
;
250 split
->block_len
= em
->block_len
;
251 split
->block_start
= em
->block_start
;
252 split
->orig_start
= em
->orig_start
;
254 split
->block_len
= split
->len
;
255 split
->block_start
= em
->block_start
+ diff
;
256 split
->orig_start
= split
->start
;
259 ret
= add_extent_mapping(em_tree
, split
);
261 free_extent_map(split
);
264 spin_unlock(&em_tree
->lock
);
268 /* once for the tree*/
272 free_extent_map(split
);
274 free_extent_map(split2
);
279 * this is very complex, but the basic idea is to drop all extents
280 * in the range start - end. hint_block is filled in with a block number
281 * that would be a good hint to the block allocator for this file.
283 * If an extent intersects the range but is not entirely inside the range
284 * it is either truncated or split. Anything entirely inside the range
285 * is deleted from the tree.
287 * inline_limit is used to tell this code which offsets in the file to keep
288 * if they contain inline extents.
290 noinline
int btrfs_drop_extents(struct btrfs_trans_handle
*trans
,
291 struct btrfs_root
*root
, struct inode
*inode
,
292 u64 start
, u64 end
, u64 locked_end
,
293 u64 inline_limit
, u64
*hint_byte
)
296 u64 search_start
= start
;
299 u64 orig_locked_end
= locked_end
;
302 u16 other_encoding
= 0;
303 struct extent_buffer
*leaf
;
304 struct btrfs_file_extent_item
*extent
;
305 struct btrfs_path
*path
;
306 struct btrfs_key key
;
307 struct btrfs_file_extent_item old
;
318 btrfs_drop_extent_cache(inode
, start
, end
- 1, 0);
320 path
= btrfs_alloc_path();
325 btrfs_release_path(root
, path
);
326 ret
= btrfs_lookup_file_extent(trans
, root
, path
, inode
->i_ino
,
331 if (path
->slots
[0] == 0) {
345 leaf
= path
->nodes
[0];
346 slot
= path
->slots
[0];
348 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
349 if (btrfs_key_type(&key
) == BTRFS_EXTENT_DATA_KEY
&&
353 if (btrfs_key_type(&key
) > BTRFS_EXTENT_DATA_KEY
||
354 key
.objectid
!= inode
->i_ino
) {
358 search_start
= max(key
.offset
, start
);
361 if (btrfs_key_type(&key
) == BTRFS_EXTENT_DATA_KEY
) {
362 extent
= btrfs_item_ptr(leaf
, slot
,
363 struct btrfs_file_extent_item
);
364 found_type
= btrfs_file_extent_type(leaf
, extent
);
365 compression
= btrfs_file_extent_compression(leaf
,
367 encryption
= btrfs_file_extent_encryption(leaf
,
369 other_encoding
= btrfs_file_extent_other_encoding(leaf
,
371 if (found_type
== BTRFS_FILE_EXTENT_REG
||
372 found_type
== BTRFS_FILE_EXTENT_PREALLOC
) {
374 btrfs_file_extent_disk_bytenr(leaf
,
377 *hint_byte
= extent_end
;
379 extent_end
= key
.offset
+
380 btrfs_file_extent_num_bytes(leaf
, extent
);
381 ram_bytes
= btrfs_file_extent_ram_bytes(leaf
,
384 } else if (found_type
== BTRFS_FILE_EXTENT_INLINE
) {
386 extent_end
= key
.offset
+
387 btrfs_file_extent_inline_len(leaf
, extent
);
390 extent_end
= search_start
;
393 /* we found nothing we can drop */
394 if ((!found_extent
&& !found_inline
) ||
395 search_start
>= extent_end
) {
398 nritems
= btrfs_header_nritems(leaf
);
399 if (slot
>= nritems
- 1) {
400 nextret
= btrfs_next_leaf(root
, path
);
410 if (end
<= extent_end
&& start
>= key
.offset
&& found_inline
)
411 *hint_byte
= EXTENT_MAP_INLINE
;
414 read_extent_buffer(leaf
, &old
, (unsigned long)extent
,
418 if (end
< extent_end
&& end
>= key
.offset
) {
420 if (found_inline
&& start
<= key
.offset
)
424 if (bookend
&& found_extent
) {
425 if (locked_end
< extent_end
) {
426 ret
= try_lock_extent(&BTRFS_I(inode
)->io_tree
,
427 locked_end
, extent_end
- 1,
430 btrfs_release_path(root
, path
);
431 lock_extent(&BTRFS_I(inode
)->io_tree
,
432 locked_end
, extent_end
- 1,
434 locked_end
= extent_end
;
437 locked_end
= extent_end
;
439 disk_bytenr
= le64_to_cpu(old
.disk_bytenr
);
440 if (disk_bytenr
!= 0) {
441 ret
= btrfs_inc_extent_ref(trans
, root
,
443 le64_to_cpu(old
.disk_num_bytes
), 0,
444 root
->root_key
.objectid
,
445 key
.objectid
, key
.offset
-
446 le64_to_cpu(old
.offset
));
452 u64 mask
= root
->sectorsize
- 1;
453 search_start
= (extent_end
+ mask
) & ~mask
;
455 search_start
= extent_end
;
457 /* truncate existing extent */
458 if (start
> key
.offset
) {
462 WARN_ON(start
& (root
->sectorsize
- 1));
464 new_num
= start
- key
.offset
;
465 old_num
= btrfs_file_extent_num_bytes(leaf
,
468 btrfs_file_extent_disk_bytenr(leaf
,
470 if (btrfs_file_extent_disk_bytenr(leaf
,
472 inode_sub_bytes(inode
, old_num
-
475 btrfs_set_file_extent_num_bytes(leaf
,
477 btrfs_mark_buffer_dirty(leaf
);
478 } else if (key
.offset
< inline_limit
&&
479 (end
> extent_end
) &&
480 (inline_limit
< extent_end
)) {
482 new_size
= btrfs_file_extent_calc_inline_size(
483 inline_limit
- key
.offset
);
484 inode_sub_bytes(inode
, extent_end
-
486 btrfs_set_file_extent_ram_bytes(leaf
, extent
,
488 if (!compression
&& !encryption
) {
489 btrfs_truncate_item(trans
, root
, path
,
494 /* delete the entire extent */
497 inode_sub_bytes(inode
, extent_end
-
499 ret
= btrfs_del_item(trans
, root
, path
);
500 /* TODO update progress marker and return */
503 btrfs_release_path(root
, path
);
504 /* the extent will be freed later */
506 if (bookend
&& found_inline
&& start
<= key
.offset
) {
508 new_size
= btrfs_file_extent_calc_inline_size(
510 inode_sub_bytes(inode
, end
- key
.offset
);
511 btrfs_set_file_extent_ram_bytes(leaf
, extent
,
513 if (!compression
&& !encryption
)
514 ret
= btrfs_truncate_item(trans
, root
, path
,
518 /* create bookend, splitting the extent in two */
519 if (bookend
&& found_extent
) {
520 struct btrfs_key ins
;
521 ins
.objectid
= inode
->i_ino
;
523 btrfs_set_key_type(&ins
, BTRFS_EXTENT_DATA_KEY
);
525 btrfs_release_path(root
, path
);
526 path
->leave_spinning
= 1;
527 ret
= btrfs_insert_empty_item(trans
, root
, path
, &ins
,
531 leaf
= path
->nodes
[0];
532 extent
= btrfs_item_ptr(leaf
, path
->slots
[0],
533 struct btrfs_file_extent_item
);
534 write_extent_buffer(leaf
, &old
,
535 (unsigned long)extent
, sizeof(old
));
537 btrfs_set_file_extent_compression(leaf
, extent
,
539 btrfs_set_file_extent_encryption(leaf
, extent
,
541 btrfs_set_file_extent_other_encoding(leaf
, extent
,
543 btrfs_set_file_extent_offset(leaf
, extent
,
544 le64_to_cpu(old
.offset
) + end
- key
.offset
);
545 WARN_ON(le64_to_cpu(old
.num_bytes
) <
547 btrfs_set_file_extent_num_bytes(leaf
, extent
,
551 * set the ram bytes to the size of the full extent
552 * before splitting. This is a worst case flag,
553 * but its the best we can do because we don't know
554 * how splitting affects compression
556 btrfs_set_file_extent_ram_bytes(leaf
, extent
,
558 btrfs_set_file_extent_type(leaf
, extent
, found_type
);
560 btrfs_unlock_up_safe(path
, 1);
561 btrfs_mark_buffer_dirty(path
->nodes
[0]);
562 btrfs_set_lock_blocking(path
->nodes
[0]);
564 path
->leave_spinning
= 0;
565 btrfs_release_path(root
, path
);
566 if (disk_bytenr
!= 0)
567 inode_add_bytes(inode
, extent_end
- end
);
570 if (found_extent
&& !keep
) {
571 u64 old_disk_bytenr
= le64_to_cpu(old
.disk_bytenr
);
573 if (old_disk_bytenr
!= 0) {
574 inode_sub_bytes(inode
,
575 le64_to_cpu(old
.num_bytes
));
576 ret
= btrfs_free_extent(trans
, root
,
578 le64_to_cpu(old
.disk_num_bytes
),
579 0, root
->root_key
.objectid
,
580 key
.objectid
, key
.offset
-
581 le64_to_cpu(old
.offset
));
583 *hint_byte
= old_disk_bytenr
;
587 if (search_start
>= end
) {
593 btrfs_free_path(path
);
594 if (locked_end
> orig_locked_end
) {
595 unlock_extent(&BTRFS_I(inode
)->io_tree
, orig_locked_end
,
596 locked_end
- 1, GFP_NOFS
);
601 static int extent_mergeable(struct extent_buffer
*leaf
, int slot
,
602 u64 objectid
, u64 bytenr
, u64
*start
, u64
*end
)
604 struct btrfs_file_extent_item
*fi
;
605 struct btrfs_key key
;
608 if (slot
< 0 || slot
>= btrfs_header_nritems(leaf
))
611 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
612 if (key
.objectid
!= objectid
|| key
.type
!= BTRFS_EXTENT_DATA_KEY
)
615 fi
= btrfs_item_ptr(leaf
, slot
, struct btrfs_file_extent_item
);
616 if (btrfs_file_extent_type(leaf
, fi
) != BTRFS_FILE_EXTENT_REG
||
617 btrfs_file_extent_disk_bytenr(leaf
, fi
) != bytenr
||
618 btrfs_file_extent_compression(leaf
, fi
) ||
619 btrfs_file_extent_encryption(leaf
, fi
) ||
620 btrfs_file_extent_other_encoding(leaf
, fi
))
623 extent_end
= key
.offset
+ btrfs_file_extent_num_bytes(leaf
, fi
);
624 if ((*start
&& *start
!= key
.offset
) || (*end
&& *end
!= extent_end
))
633 * Mark extent in the range start - end as written.
635 * This changes extent type from 'pre-allocated' to 'regular'. If only
636 * part of extent is marked as written, the extent will be split into
639 int btrfs_mark_extent_written(struct btrfs_trans_handle
*trans
,
640 struct btrfs_root
*root
,
641 struct inode
*inode
, u64 start
, u64 end
)
643 struct extent_buffer
*leaf
;
644 struct btrfs_path
*path
;
645 struct btrfs_file_extent_item
*fi
;
646 struct btrfs_key key
;
654 u64 locked_end
= end
;
659 btrfs_drop_extent_cache(inode
, start
, end
- 1, 0);
661 path
= btrfs_alloc_path();
664 key
.objectid
= inode
->i_ino
;
665 key
.type
= BTRFS_EXTENT_DATA_KEY
;
669 key
.offset
= split
- 1;
671 ret
= btrfs_search_slot(trans
, root
, &key
, path
, -1, 1);
672 if (ret
> 0 && path
->slots
[0] > 0)
675 leaf
= path
->nodes
[0];
676 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
677 BUG_ON(key
.objectid
!= inode
->i_ino
||
678 key
.type
!= BTRFS_EXTENT_DATA_KEY
);
679 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
680 struct btrfs_file_extent_item
);
681 extent_type
= btrfs_file_extent_type(leaf
, fi
);
682 BUG_ON(extent_type
!= BTRFS_FILE_EXTENT_PREALLOC
);
683 extent_end
= key
.offset
+ btrfs_file_extent_num_bytes(leaf
, fi
);
684 BUG_ON(key
.offset
> start
|| extent_end
< end
);
686 bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
687 num_bytes
= btrfs_file_extent_disk_num_bytes(leaf
, fi
);
688 orig_offset
= key
.offset
- btrfs_file_extent_offset(leaf
, fi
);
690 if (key
.offset
== start
)
693 if (key
.offset
== start
&& extent_end
== end
) {
698 if (extent_mergeable(leaf
, path
->slots
[0] + 1, inode
->i_ino
,
699 bytenr
, &other_start
, &other_end
)) {
700 extent_end
= other_end
;
701 del_slot
= path
->slots
[0] + 1;
703 ret
= btrfs_free_extent(trans
, root
, bytenr
, num_bytes
,
704 0, root
->root_key
.objectid
,
705 inode
->i_ino
, orig_offset
);
710 if (extent_mergeable(leaf
, path
->slots
[0] - 1, inode
->i_ino
,
711 bytenr
, &other_start
, &other_end
)) {
712 key
.offset
= other_start
;
713 del_slot
= path
->slots
[0];
715 ret
= btrfs_free_extent(trans
, root
, bytenr
, num_bytes
,
716 0, root
->root_key
.objectid
,
717 inode
->i_ino
, orig_offset
);
722 btrfs_set_file_extent_type(leaf
, fi
,
723 BTRFS_FILE_EXTENT_REG
);
727 fi
= btrfs_item_ptr(leaf
, del_slot
- 1,
728 struct btrfs_file_extent_item
);
729 btrfs_set_file_extent_type(leaf
, fi
, BTRFS_FILE_EXTENT_REG
);
730 btrfs_set_file_extent_num_bytes(leaf
, fi
,
731 extent_end
- key
.offset
);
732 btrfs_mark_buffer_dirty(leaf
);
734 ret
= btrfs_del_items(trans
, root
, path
, del_slot
, del_nr
);
737 } else if (split
== start
) {
738 if (locked_end
< extent_end
) {
739 ret
= try_lock_extent(&BTRFS_I(inode
)->io_tree
,
740 locked_end
, extent_end
- 1, GFP_NOFS
);
742 btrfs_release_path(root
, path
);
743 lock_extent(&BTRFS_I(inode
)->io_tree
,
744 locked_end
, extent_end
- 1, GFP_NOFS
);
745 locked_end
= extent_end
;
748 locked_end
= extent_end
;
750 btrfs_set_file_extent_num_bytes(leaf
, fi
, split
- key
.offset
);
752 BUG_ON(key
.offset
!= start
);
754 btrfs_set_file_extent_offset(leaf
, fi
, key
.offset
-
756 btrfs_set_file_extent_num_bytes(leaf
, fi
, extent_end
- split
);
757 btrfs_set_item_key_safe(trans
, root
, path
, &key
);
761 if (extent_end
== end
) {
763 extent_type
= BTRFS_FILE_EXTENT_REG
;
765 if (extent_end
== end
&& split
== start
) {
768 if (extent_mergeable(leaf
, path
->slots
[0] + 1, inode
->i_ino
,
769 bytenr
, &other_start
, &other_end
)) {
771 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
772 struct btrfs_file_extent_item
);
774 btrfs_set_item_key_safe(trans
, root
, path
, &key
);
775 btrfs_set_file_extent_offset(leaf
, fi
, key
.offset
-
777 btrfs_set_file_extent_num_bytes(leaf
, fi
,
782 if (extent_end
== end
&& split
== end
) {
785 if (extent_mergeable(leaf
, path
->slots
[0] - 1 , inode
->i_ino
,
786 bytenr
, &other_start
, &other_end
)) {
788 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
789 struct btrfs_file_extent_item
);
790 btrfs_set_file_extent_num_bytes(leaf
, fi
, extent_end
-
796 btrfs_mark_buffer_dirty(leaf
);
798 ret
= btrfs_inc_extent_ref(trans
, root
, bytenr
, num_bytes
, 0,
799 root
->root_key
.objectid
,
800 inode
->i_ino
, orig_offset
);
802 btrfs_release_path(root
, path
);
805 ret
= btrfs_insert_empty_item(trans
, root
, path
, &key
, sizeof(*fi
));
808 leaf
= path
->nodes
[0];
809 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
810 struct btrfs_file_extent_item
);
811 btrfs_set_file_extent_generation(leaf
, fi
, trans
->transid
);
812 btrfs_set_file_extent_type(leaf
, fi
, extent_type
);
813 btrfs_set_file_extent_disk_bytenr(leaf
, fi
, bytenr
);
814 btrfs_set_file_extent_disk_num_bytes(leaf
, fi
, num_bytes
);
815 btrfs_set_file_extent_offset(leaf
, fi
, key
.offset
- orig_offset
);
816 btrfs_set_file_extent_num_bytes(leaf
, fi
, extent_end
- key
.offset
);
817 btrfs_set_file_extent_ram_bytes(leaf
, fi
, num_bytes
);
818 btrfs_set_file_extent_compression(leaf
, fi
, 0);
819 btrfs_set_file_extent_encryption(leaf
, fi
, 0);
820 btrfs_set_file_extent_other_encoding(leaf
, fi
, 0);
822 btrfs_mark_buffer_dirty(leaf
);
825 btrfs_release_path(root
, path
);
826 if (split_end
&& split
== start
) {
830 if (locked_end
> end
) {
831 unlock_extent(&BTRFS_I(inode
)->io_tree
, end
, locked_end
- 1,
834 btrfs_free_path(path
);
839 * this gets pages into the page cache and locks them down, it also properly
840 * waits for data=ordered extents to finish before allowing the pages to be
843 static noinline
int prepare_pages(struct btrfs_root
*root
, struct file
*file
,
844 struct page
**pages
, size_t num_pages
,
845 loff_t pos
, unsigned long first_index
,
846 unsigned long last_index
, size_t write_bytes
)
849 unsigned long index
= pos
>> PAGE_CACHE_SHIFT
;
850 struct inode
*inode
= fdentry(file
)->d_inode
;
855 start_pos
= pos
& ~((u64
)root
->sectorsize
- 1);
856 last_pos
= ((u64
)index
+ num_pages
) << PAGE_CACHE_SHIFT
;
858 if (start_pos
> inode
->i_size
) {
859 err
= btrfs_cont_expand(inode
, start_pos
);
864 memset(pages
, 0, num_pages
* sizeof(struct page
*));
866 for (i
= 0; i
< num_pages
; i
++) {
867 pages
[i
] = grab_cache_page(inode
->i_mapping
, index
+ i
);
872 wait_on_page_writeback(pages
[i
]);
874 if (start_pos
< inode
->i_size
) {
875 struct btrfs_ordered_extent
*ordered
;
876 lock_extent(&BTRFS_I(inode
)->io_tree
,
877 start_pos
, last_pos
- 1, GFP_NOFS
);
878 ordered
= btrfs_lookup_first_ordered_extent(inode
,
881 ordered
->file_offset
+ ordered
->len
> start_pos
&&
882 ordered
->file_offset
< last_pos
) {
883 btrfs_put_ordered_extent(ordered
);
884 unlock_extent(&BTRFS_I(inode
)->io_tree
,
885 start_pos
, last_pos
- 1, GFP_NOFS
);
886 for (i
= 0; i
< num_pages
; i
++) {
887 unlock_page(pages
[i
]);
888 page_cache_release(pages
[i
]);
890 btrfs_wait_ordered_range(inode
, start_pos
,
891 last_pos
- start_pos
);
895 btrfs_put_ordered_extent(ordered
);
897 clear_extent_bits(&BTRFS_I(inode
)->io_tree
, start_pos
,
898 last_pos
- 1, EXTENT_DIRTY
| EXTENT_DELALLOC
,
900 unlock_extent(&BTRFS_I(inode
)->io_tree
,
901 start_pos
, last_pos
- 1, GFP_NOFS
);
903 for (i
= 0; i
< num_pages
; i
++) {
904 clear_page_dirty_for_io(pages
[i
]);
905 set_page_extent_mapped(pages
[i
]);
906 WARN_ON(!PageLocked(pages
[i
]));
911 static ssize_t
btrfs_file_write(struct file
*file
, const char __user
*buf
,
912 size_t count
, loff_t
*ppos
)
916 ssize_t num_written
= 0;
919 struct inode
*inode
= fdentry(file
)->d_inode
;
920 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
921 struct page
**pages
= NULL
;
923 struct page
*pinned
[2];
924 unsigned long first_index
;
925 unsigned long last_index
;
928 will_write
= ((file
->f_flags
& O_SYNC
) || IS_SYNC(inode
) ||
929 (file
->f_flags
& O_DIRECT
));
931 nrptrs
= min((count
+ PAGE_CACHE_SIZE
- 1) / PAGE_CACHE_SIZE
,
932 PAGE_CACHE_SIZE
/ (sizeof(struct page
*)));
939 vfs_check_frozen(inode
->i_sb
, SB_FREEZE_WRITE
);
940 current
->backing_dev_info
= inode
->i_mapping
->backing_dev_info
;
941 err
= generic_write_checks(file
, &pos
, &count
, S_ISBLK(inode
->i_mode
));
947 err
= file_remove_suid(file
);
950 file_update_time(file
);
952 pages
= kmalloc(nrptrs
* sizeof(struct page
*), GFP_KERNEL
);
954 mutex_lock(&inode
->i_mutex
);
955 BTRFS_I(inode
)->sequence
++;
956 first_index
= pos
>> PAGE_CACHE_SHIFT
;
957 last_index
= (pos
+ count
) >> PAGE_CACHE_SHIFT
;
960 * there are lots of better ways to do this, but this code
961 * makes sure the first and last page in the file range are
962 * up to date and ready for cow
964 if ((pos
& (PAGE_CACHE_SIZE
- 1))) {
965 pinned
[0] = grab_cache_page(inode
->i_mapping
, first_index
);
966 if (!PageUptodate(pinned
[0])) {
967 ret
= btrfs_readpage(NULL
, pinned
[0]);
969 wait_on_page_locked(pinned
[0]);
971 unlock_page(pinned
[0]);
974 if ((pos
+ count
) & (PAGE_CACHE_SIZE
- 1)) {
975 pinned
[1] = grab_cache_page(inode
->i_mapping
, last_index
);
976 if (!PageUptodate(pinned
[1])) {
977 ret
= btrfs_readpage(NULL
, pinned
[1]);
979 wait_on_page_locked(pinned
[1]);
981 unlock_page(pinned
[1]);
986 size_t offset
= pos
& (PAGE_CACHE_SIZE
- 1);
987 size_t write_bytes
= min(count
, nrptrs
*
988 (size_t)PAGE_CACHE_SIZE
-
990 size_t num_pages
= (write_bytes
+ PAGE_CACHE_SIZE
- 1) >>
993 WARN_ON(num_pages
> nrptrs
);
994 memset(pages
, 0, sizeof(struct page
*) * nrptrs
);
996 ret
= btrfs_check_data_free_space(root
, inode
, write_bytes
);
1000 ret
= prepare_pages(root
, file
, pages
, num_pages
,
1001 pos
, first_index
, last_index
,
1004 btrfs_free_reserved_data_space(root
, inode
,
1009 ret
= btrfs_copy_from_user(pos
, num_pages
,
1010 write_bytes
, pages
, buf
);
1012 btrfs_free_reserved_data_space(root
, inode
,
1014 btrfs_drop_pages(pages
, num_pages
);
1018 ret
= dirty_and_release_pages(NULL
, root
, file
, pages
,
1019 num_pages
, pos
, write_bytes
);
1020 btrfs_drop_pages(pages
, num_pages
);
1022 btrfs_free_reserved_data_space(root
, inode
,
1028 btrfs_fdatawrite_range(inode
->i_mapping
, pos
,
1029 pos
+ write_bytes
- 1,
1032 balance_dirty_pages_ratelimited_nr(inode
->i_mapping
,
1035 (root
->leafsize
>> PAGE_CACHE_SHIFT
) + 1)
1036 btrfs_btree_balance_dirty(root
, 1);
1037 btrfs_throttle(root
);
1041 count
-= write_bytes
;
1043 num_written
+= write_bytes
;
1048 mutex_unlock(&inode
->i_mutex
);
1055 page_cache_release(pinned
[0]);
1057 page_cache_release(pinned
[1]);
1061 * we want to make sure fsync finds this change
1062 * but we haven't joined a transaction running right now.
1064 * Later on, someone is sure to update the inode and get the
1065 * real transid recorded.
1067 * We set last_trans now to the fs_info generation + 1,
1068 * this will either be one more than the running transaction
1069 * or the generation used for the next transaction if there isn't
1070 * one running right now.
1072 BTRFS_I(inode
)->last_trans
= root
->fs_info
->generation
+ 1;
1074 if (num_written
> 0 && will_write
) {
1075 struct btrfs_trans_handle
*trans
;
1077 err
= btrfs_wait_ordered_range(inode
, start_pos
, num_written
);
1081 if ((file
->f_flags
& O_SYNC
) || IS_SYNC(inode
)) {
1082 trans
= btrfs_start_transaction(root
, 1);
1083 ret
= btrfs_log_dentry_safe(trans
, root
,
1086 ret
= btrfs_sync_log(trans
, root
);
1088 btrfs_end_transaction(trans
, root
);
1090 btrfs_commit_transaction(trans
, root
);
1092 btrfs_commit_transaction(trans
, root
);
1095 if (file
->f_flags
& O_DIRECT
) {
1096 invalidate_mapping_pages(inode
->i_mapping
,
1097 start_pos
>> PAGE_CACHE_SHIFT
,
1098 (start_pos
+ num_written
- 1) >> PAGE_CACHE_SHIFT
);
1101 current
->backing_dev_info
= NULL
;
1102 return num_written
? num_written
: err
;
1105 int btrfs_release_file(struct inode
*inode
, struct file
*filp
)
1108 * ordered_data_close is set by settattr when we are about to truncate
1109 * a file from a non-zero size to a zero size. This tries to
1110 * flush down new bytes that may have been written if the
1111 * application were using truncate to replace a file in place.
1113 if (BTRFS_I(inode
)->ordered_data_close
) {
1114 BTRFS_I(inode
)->ordered_data_close
= 0;
1115 btrfs_add_ordered_operation(NULL
, BTRFS_I(inode
)->root
, inode
);
1116 if (inode
->i_size
> BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT
)
1117 filemap_flush(inode
->i_mapping
);
1119 if (filp
->private_data
)
1120 btrfs_ioctl_trans_end(filp
);
1125 * fsync call for both files and directories. This logs the inode into
1126 * the tree log instead of forcing full commits whenever possible.
1128 * It needs to call filemap_fdatawait so that all ordered extent updates are
1129 * in the metadata btree are up to date for copying to the log.
1131 * It drops the inode mutex before doing the tree log commit. This is an
1132 * important optimization for directories because holding the mutex prevents
1133 * new operations on the dir while we write to disk.
1135 int btrfs_sync_file(struct file
*file
, struct dentry
*dentry
, int datasync
)
1137 struct inode
*inode
= dentry
->d_inode
;
1138 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
1140 struct btrfs_trans_handle
*trans
;
1143 * check the transaction that last modified this inode
1144 * and see if its already been committed
1146 if (!BTRFS_I(inode
)->last_trans
)
1149 mutex_lock(&root
->fs_info
->trans_mutex
);
1150 if (BTRFS_I(inode
)->last_trans
<=
1151 root
->fs_info
->last_trans_committed
) {
1152 BTRFS_I(inode
)->last_trans
= 0;
1153 mutex_unlock(&root
->fs_info
->trans_mutex
);
1156 mutex_unlock(&root
->fs_info
->trans_mutex
);
1159 filemap_fdatawrite(inode
->i_mapping
);
1160 btrfs_wait_ordered_range(inode
, 0, (u64
)-1);
1163 if (datasync
&& !(inode
->i_state
& I_DIRTY_PAGES
))
1166 * ok we haven't committed the transaction yet, lets do a commit
1168 if (file
&& file
->private_data
)
1169 btrfs_ioctl_trans_end(file
);
1171 trans
= btrfs_start_transaction(root
, 1);
1177 ret
= btrfs_log_dentry_safe(trans
, root
, dentry
);
1181 /* we've logged all the items and now have a consistent
1182 * version of the file in the log. It is possible that
1183 * someone will come in and modify the file, but that's
1184 * fine because the log is consistent on disk, and we
1185 * have references to all of the file's extents
1187 * It is possible that someone will come in and log the
1188 * file again, but that will end up using the synchronization
1189 * inside btrfs_sync_log to keep things safe.
1191 mutex_unlock(&dentry
->d_inode
->i_mutex
);
1194 ret
= btrfs_commit_transaction(trans
, root
);
1196 ret
= btrfs_sync_log(trans
, root
);
1198 ret
= btrfs_end_transaction(trans
, root
);
1200 ret
= btrfs_commit_transaction(trans
, root
);
1202 mutex_lock(&dentry
->d_inode
->i_mutex
);
1204 return ret
> 0 ? EIO
: ret
;
1207 static struct vm_operations_struct btrfs_file_vm_ops
= {
1208 .fault
= filemap_fault
,
1209 .page_mkwrite
= btrfs_page_mkwrite
,
1212 static int btrfs_file_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
1214 vma
->vm_ops
= &btrfs_file_vm_ops
;
1215 file_accessed(filp
);
1219 struct file_operations btrfs_file_operations
= {
1220 .llseek
= generic_file_llseek
,
1221 .read
= do_sync_read
,
1222 .aio_read
= generic_file_aio_read
,
1223 .splice_read
= generic_file_splice_read
,
1224 .write
= btrfs_file_write
,
1225 .mmap
= btrfs_file_mmap
,
1226 .open
= generic_file_open
,
1227 .release
= btrfs_release_file
,
1228 .fsync
= btrfs_sync_file
,
1229 .unlocked_ioctl
= btrfs_ioctl
,
1230 #ifdef CONFIG_COMPAT
1231 .compat_ioctl
= btrfs_ioctl
,