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>
32 #include <linux/version.h>
35 #include "transaction.h"
36 #include "btrfs_inode.h"
38 #include "print-tree.h"
44 /* simple helper to fault in pages and copy. This should go away
45 * and be replaced with calls into generic code.
47 static int noinline
btrfs_copy_from_user(loff_t pos
, int num_pages
,
49 struct page
**prepared_pages
,
50 const char __user
* buf
)
54 int offset
= pos
& (PAGE_CACHE_SIZE
- 1);
56 for (i
= 0; i
< num_pages
&& write_bytes
> 0; i
++, offset
= 0) {
57 size_t count
= min_t(size_t,
58 PAGE_CACHE_SIZE
- offset
, write_bytes
);
59 struct page
*page
= prepared_pages
[i
];
60 fault_in_pages_readable(buf
, count
);
62 /* Copy data from userspace to the current page */
64 page_fault
= __copy_from_user(page_address(page
) + offset
,
66 /* Flush processor's dcache for this page */
67 flush_dcache_page(page
);
75 return page_fault
? -EFAULT
: 0;
79 * unlocks pages after btrfs_file_write is done with them
81 static void noinline
btrfs_drop_pages(struct page
**pages
, size_t num_pages
)
84 for (i
= 0; i
< num_pages
; i
++) {
87 /* page checked is some magic around finding pages that
88 * have been modified without going through btrfs_set_page_dirty
91 ClearPageChecked(pages
[i
]);
92 unlock_page(pages
[i
]);
93 mark_page_accessed(pages
[i
]);
94 page_cache_release(pages
[i
]);
98 /* this does all the hard work for inserting an inline extent into
99 * the btree. Any existing inline extent is extended as required to make room,
100 * otherwise things are inserted as required into the btree
102 static int noinline
insert_inline_extent(struct btrfs_trans_handle
*trans
,
103 struct btrfs_root
*root
, struct inode
*inode
,
104 u64 offset
, size_t size
,
105 struct page
**pages
, size_t page_offset
,
108 struct btrfs_key key
;
109 struct btrfs_path
*path
;
110 struct extent_buffer
*leaf
;
113 struct btrfs_file_extent_item
*ei
;
121 path
= btrfs_alloc_path();
125 btrfs_set_trans_block_group(trans
, inode
);
127 key
.objectid
= inode
->i_ino
;
129 btrfs_set_key_type(&key
, BTRFS_EXTENT_DATA_KEY
);
131 ret
= btrfs_search_slot(trans
, root
, &key
, path
, 0, 1);
137 struct btrfs_key found_key
;
139 if (path
->slots
[0] == 0)
143 leaf
= path
->nodes
[0];
144 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
146 if (found_key
.objectid
!= inode
->i_ino
)
149 if (found_key
.type
!= BTRFS_EXTENT_DATA_KEY
)
151 ei
= btrfs_item_ptr(leaf
, path
->slots
[0],
152 struct btrfs_file_extent_item
);
154 if (btrfs_file_extent_type(leaf
, ei
) !=
155 BTRFS_FILE_EXTENT_INLINE
) {
158 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
165 leaf
= path
->nodes
[0];
166 ei
= btrfs_item_ptr(leaf
, path
->slots
[0],
167 struct btrfs_file_extent_item
);
169 if (btrfs_file_extent_type(leaf
, ei
) !=
170 BTRFS_FILE_EXTENT_INLINE
) {
172 btrfs_print_leaf(root
, leaf
);
173 printk("found wasn't inline offset %Lu inode %lu\n",
174 offset
, inode
->i_ino
);
177 found_size
= btrfs_file_extent_inline_len(leaf
,
178 btrfs_item_nr(leaf
, path
->slots
[0]));
179 found_end
= key
.offset
+ found_size
;
181 if (found_end
< offset
+ size
) {
182 btrfs_release_path(root
, path
);
183 ret
= btrfs_search_slot(trans
, root
, &key
, path
,
184 offset
+ size
- found_end
, 1);
187 ret
= btrfs_extend_item(trans
, root
, path
,
188 offset
+ size
- found_end
);
193 leaf
= path
->nodes
[0];
194 ei
= btrfs_item_ptr(leaf
, path
->slots
[0],
195 struct btrfs_file_extent_item
);
196 inode
->i_blocks
+= (offset
+ size
- found_end
) >> 9;
198 if (found_end
< offset
) {
199 ptr
= btrfs_file_extent_inline_start(ei
) + found_size
;
200 memset_extent_buffer(leaf
, 0, ptr
, offset
- found_end
);
204 btrfs_release_path(root
, path
);
205 datasize
= offset
+ size
- key
.offset
;
206 inode
->i_blocks
+= datasize
>> 9;
207 datasize
= btrfs_file_extent_calc_inline_size(datasize
);
208 ret
= btrfs_insert_empty_item(trans
, root
, path
, &key
,
212 printk("got bad ret %d\n", ret
);
215 leaf
= path
->nodes
[0];
216 ei
= btrfs_item_ptr(leaf
, path
->slots
[0],
217 struct btrfs_file_extent_item
);
218 btrfs_set_file_extent_generation(leaf
, ei
, trans
->transid
);
219 btrfs_set_file_extent_type(leaf
, ei
, BTRFS_FILE_EXTENT_INLINE
);
221 ptr
= btrfs_file_extent_inline_start(ei
) + offset
- key
.offset
;
227 kaddr
= kmap_atomic(page
, KM_USER0
);
228 cur_size
= min_t(size_t, PAGE_CACHE_SIZE
- page_offset
, size
);
229 write_extent_buffer(leaf
, kaddr
+ page_offset
, ptr
, cur_size
);
230 kunmap_atomic(kaddr
, KM_USER0
);
234 if (i
>= num_pages
) {
235 printk("i %d num_pages %d\n", i
, num_pages
);
239 btrfs_mark_buffer_dirty(leaf
);
241 btrfs_free_path(path
);
246 * after copy_from_user, pages need to be dirtied and we need to make
247 * sure holes are created between the current EOF and the start of
248 * any next extents (if required).
250 * this also makes the decision about creating an inline extent vs
251 * doing real data extents, marking pages dirty and delalloc as required.
253 static int noinline
dirty_and_release_pages(struct btrfs_trans_handle
*trans
,
254 struct btrfs_root
*root
,
263 struct inode
*inode
= fdentry(file
)->d_inode
;
264 struct extent_io_tree
*io_tree
= &BTRFS_I(inode
)->io_tree
;
268 u64 end_of_last_block
;
269 u64 end_pos
= pos
+ write_bytes
;
272 loff_t isize
= i_size_read(inode
);
274 start_pos
= pos
& ~((u64
)root
->sectorsize
- 1);
275 num_bytes
= (write_bytes
+ pos
- start_pos
+
276 root
->sectorsize
- 1) & ~((u64
)root
->sectorsize
- 1);
278 end_of_last_block
= start_pos
+ num_bytes
- 1;
280 lock_extent(io_tree
, start_pos
, end_of_last_block
, GFP_NOFS
);
281 trans
= btrfs_join_transaction(root
, 1);
286 btrfs_set_trans_block_group(trans
, inode
);
289 if ((end_of_last_block
& 4095) == 0) {
290 printk("strange end of last %Lu %zu %Lu\n", start_pos
, write_bytes
, end_of_last_block
);
292 set_extent_uptodate(io_tree
, start_pos
, end_of_last_block
, GFP_NOFS
);
294 /* FIXME...EIEIO, ENOSPC and more */
295 /* insert any holes we need to create */
296 if (isize
< start_pos
) {
297 u64 last_pos_in_file
;
299 u64 mask
= root
->sectorsize
- 1;
300 last_pos_in_file
= (isize
+ mask
) & ~mask
;
301 hole_size
= (start_pos
- last_pos_in_file
+ mask
) & ~mask
;
303 btrfs_wait_ordered_range(inode
, last_pos_in_file
,
304 last_pos_in_file
+ hole_size
);
305 mutex_lock(&BTRFS_I(inode
)->extent_mutex
);
306 err
= btrfs_drop_extents(trans
, root
, inode
,
308 last_pos_in_file
+ hole_size
,
314 err
= btrfs_insert_file_extent(trans
, root
,
318 btrfs_drop_extent_cache(inode
, last_pos_in_file
,
319 last_pos_in_file
+ hole_size
- 1, 0);
320 mutex_unlock(&BTRFS_I(inode
)->extent_mutex
);
321 btrfs_check_file(root
, inode
);
328 * either allocate an extent for the new bytes or setup the key
329 * to show we are doing inline data in the extent
331 inline_size
= end_pos
;
332 if (isize
>= BTRFS_MAX_INLINE_DATA_SIZE(root
) ||
333 inline_size
> root
->fs_info
->max_inline
||
334 (inline_size
& (root
->sectorsize
-1)) == 0 ||
335 inline_size
>= BTRFS_MAX_INLINE_DATA_SIZE(root
)) {
336 /* check for reserved extents on each page, we don't want
337 * to reset the delalloc bit on things that already have
340 btrfs_set_extent_delalloc(inode
, start_pos
, end_of_last_block
);
341 for (i
= 0; i
< num_pages
; i
++) {
342 struct page
*p
= pages
[i
];
349 /* step one, delete the existing extents in this range */
350 aligned_end
= (pos
+ write_bytes
+ root
->sectorsize
- 1) &
351 ~((u64
)root
->sectorsize
- 1);
352 mutex_lock(&BTRFS_I(inode
)->extent_mutex
);
353 err
= btrfs_drop_extents(trans
, root
, inode
, start_pos
,
354 aligned_end
, aligned_end
, &hint_byte
);
357 if (isize
> inline_size
)
358 inline_size
= min_t(u64
, isize
, aligned_end
);
359 inline_size
-= start_pos
;
360 err
= insert_inline_extent(trans
, root
, inode
, start_pos
,
361 inline_size
, pages
, 0, num_pages
);
362 btrfs_drop_extent_cache(inode
, start_pos
, aligned_end
- 1, 0);
364 mutex_unlock(&BTRFS_I(inode
)->extent_mutex
);
367 * an ugly way to do all the prop accounting around
368 * the page bits and mapping tags
370 set_page_writeback(pages
[0]);
371 end_page_writeback(pages
[0]);
374 if (end_pos
> isize
) {
375 i_size_write(inode
, end_pos
);
377 BTRFS_I(inode
)->disk_i_size
= end_pos
;
378 btrfs_update_inode(trans
, root
, inode
);
381 err
= btrfs_end_transaction(trans
, root
);
383 unlock_extent(io_tree
, start_pos
, end_of_last_block
, GFP_NOFS
);
388 * this drops all the extents in the cache that intersect the range
389 * [start, end]. Existing extents are split as required.
391 int btrfs_drop_extent_cache(struct inode
*inode
, u64 start
, u64 end
,
394 struct extent_map
*em
;
395 struct extent_map
*split
= NULL
;
396 struct extent_map
*split2
= NULL
;
397 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
398 u64 len
= end
- start
+ 1;
403 WARN_ON(end
< start
);
404 if (end
== (u64
)-1) {
410 split
= alloc_extent_map(GFP_NOFS
);
412 split2
= alloc_extent_map(GFP_NOFS
);
414 spin_lock(&em_tree
->lock
);
415 em
= lookup_extent_mapping(em_tree
, start
, len
);
417 spin_unlock(&em_tree
->lock
);
421 if (skip_pinned
&& test_bit(EXTENT_FLAG_PINNED
, &em
->flags
)) {
422 spin_unlock(&em_tree
->lock
);
423 if (em
->start
<= start
&&
424 (!testend
|| em
->start
+ em
->len
>= start
+ len
)) {
428 if (start
< em
->start
) {
429 len
= em
->start
- start
;
431 len
= start
+ len
- (em
->start
+ em
->len
);
432 start
= em
->start
+ em
->len
;
437 clear_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
438 remove_extent_mapping(em_tree
, em
);
440 if (em
->block_start
< EXTENT_MAP_LAST_BYTE
&&
442 split
->start
= em
->start
;
443 split
->len
= start
- em
->start
;
444 split
->block_start
= em
->block_start
;
445 split
->bdev
= em
->bdev
;
446 split
->flags
= flags
;
447 ret
= add_extent_mapping(em_tree
, split
);
449 free_extent_map(split
);
453 if (em
->block_start
< EXTENT_MAP_LAST_BYTE
&&
454 testend
&& em
->start
+ em
->len
> start
+ len
) {
455 u64 diff
= start
+ len
- em
->start
;
457 split
->start
= start
+ len
;
458 split
->len
= em
->start
+ em
->len
- (start
+ len
);
459 split
->bdev
= em
->bdev
;
460 split
->flags
= flags
;
462 split
->block_start
= em
->block_start
+ diff
;
464 ret
= add_extent_mapping(em_tree
, split
);
466 free_extent_map(split
);
469 spin_unlock(&em_tree
->lock
);
473 /* once for the tree*/
477 free_extent_map(split
);
479 free_extent_map(split2
);
483 int btrfs_check_file(struct btrfs_root
*root
, struct inode
*inode
)
487 struct btrfs_path
*path
;
488 struct btrfs_key found_key
;
489 struct extent_buffer
*leaf
;
490 struct btrfs_file_extent_item
*extent
;
499 path
= btrfs_alloc_path();
500 ret
= btrfs_lookup_file_extent(NULL
, root
, path
, inode
->i_ino
,
503 nritems
= btrfs_header_nritems(path
->nodes
[0]);
504 if (path
->slots
[0] >= nritems
) {
505 ret
= btrfs_next_leaf(root
, path
);
508 nritems
= btrfs_header_nritems(path
->nodes
[0]);
510 slot
= path
->slots
[0];
511 leaf
= path
->nodes
[0];
512 btrfs_item_key_to_cpu(leaf
, &found_key
, slot
);
513 if (found_key
.objectid
!= inode
->i_ino
)
515 if (found_key
.type
!= BTRFS_EXTENT_DATA_KEY
)
518 if (found_key
.offset
< last_offset
) {
520 btrfs_print_leaf(root
, leaf
);
521 printk("inode %lu found offset %Lu expected %Lu\n",
522 inode
->i_ino
, found_key
.offset
, last_offset
);
526 extent
= btrfs_item_ptr(leaf
, slot
,
527 struct btrfs_file_extent_item
);
528 found_type
= btrfs_file_extent_type(leaf
, extent
);
529 if (found_type
== BTRFS_FILE_EXTENT_REG
) {
530 extent_end
= found_key
.offset
+
531 btrfs_file_extent_num_bytes(leaf
, extent
);
532 } else if (found_type
== BTRFS_FILE_EXTENT_INLINE
) {
533 struct btrfs_item
*item
;
534 item
= btrfs_item_nr(leaf
, slot
);
535 extent_end
= found_key
.offset
+
536 btrfs_file_extent_inline_len(leaf
, item
);
537 extent_end
= (extent_end
+ root
->sectorsize
- 1) &
538 ~((u64
)root
->sectorsize
-1 );
540 last_offset
= extent_end
;
543 if (0 && last_offset
< inode
->i_size
) {
545 btrfs_print_leaf(root
, leaf
);
546 printk("inode %lu found offset %Lu size %Lu\n", inode
->i_ino
,
547 last_offset
, inode
->i_size
);
552 btrfs_free_path(path
);
558 * this is very complex, but the basic idea is to drop all extents
559 * in the range start - end. hint_block is filled in with a block number
560 * that would be a good hint to the block allocator for this file.
562 * If an extent intersects the range but is not entirely inside the range
563 * it is either truncated or split. Anything entirely inside the range
564 * is deleted from the tree.
566 * inline_limit is used to tell this code which offsets in the file to keep
567 * if they contain inline extents.
569 int noinline
btrfs_drop_extents(struct btrfs_trans_handle
*trans
,
570 struct btrfs_root
*root
, struct inode
*inode
,
571 u64 start
, u64 end
, u64 inline_limit
, u64
*hint_byte
)
574 u64 search_start
= start
;
578 struct extent_buffer
*leaf
;
579 struct btrfs_file_extent_item
*extent
;
580 struct btrfs_path
*path
;
581 struct btrfs_key key
;
582 struct btrfs_file_extent_item old
;
592 btrfs_drop_extent_cache(inode
, start
, end
- 1, 0);
594 path
= btrfs_alloc_path();
599 btrfs_release_path(root
, path
);
600 ret
= btrfs_lookup_file_extent(trans
, root
, path
, inode
->i_ino
,
605 if (path
->slots
[0] == 0) {
620 leaf
= path
->nodes
[0];
621 slot
= path
->slots
[0];
623 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
624 if (btrfs_key_type(&key
) == BTRFS_EXTENT_DATA_KEY
&&
628 if (btrfs_key_type(&key
) > BTRFS_EXTENT_DATA_KEY
||
629 key
.objectid
!= inode
->i_ino
) {
633 search_start
= key
.offset
;
636 if (btrfs_key_type(&key
) == BTRFS_EXTENT_DATA_KEY
) {
637 extent
= btrfs_item_ptr(leaf
, slot
,
638 struct btrfs_file_extent_item
);
639 found_type
= btrfs_file_extent_type(leaf
, extent
);
640 if (found_type
== BTRFS_FILE_EXTENT_REG
) {
642 btrfs_file_extent_disk_bytenr(leaf
,
645 *hint_byte
= extent_end
;
647 extent_end
= key
.offset
+
648 btrfs_file_extent_num_bytes(leaf
, extent
);
650 } else if (found_type
== BTRFS_FILE_EXTENT_INLINE
) {
651 struct btrfs_item
*item
;
652 item
= btrfs_item_nr(leaf
, slot
);
654 extent_end
= key
.offset
+
655 btrfs_file_extent_inline_len(leaf
, item
);
658 extent_end
= search_start
;
661 /* we found nothing we can drop */
662 if ((!found_extent
&& !found_inline
) ||
663 search_start
>= extent_end
) {
666 nritems
= btrfs_header_nritems(leaf
);
667 if (slot
>= nritems
- 1) {
668 nextret
= btrfs_next_leaf(root
, path
);
679 u64 mask
= root
->sectorsize
- 1;
680 search_start
= (extent_end
+ mask
) & ~mask
;
682 search_start
= extent_end
;
683 if (end
<= extent_end
&& start
>= key
.offset
&& found_inline
) {
684 *hint_byte
= EXTENT_MAP_INLINE
;
689 read_extent_buffer(leaf
, &old
, (unsigned long)extent
,
691 root_gen
= btrfs_header_generation(leaf
);
692 root_owner
= btrfs_header_owner(leaf
);
693 leaf_start
= leaf
->start
;
696 if (end
< extent_end
&& end
>= key
.offset
) {
698 if (found_inline
&& start
<= key
.offset
)
701 /* truncate existing extent */
702 if (start
> key
.offset
) {
706 WARN_ON(start
& (root
->sectorsize
- 1));
708 new_num
= start
- key
.offset
;
709 old_num
= btrfs_file_extent_num_bytes(leaf
,
712 btrfs_file_extent_disk_bytenr(leaf
,
714 if (btrfs_file_extent_disk_bytenr(leaf
,
716 dec_i_blocks(inode
, old_num
- new_num
);
718 btrfs_set_file_extent_num_bytes(leaf
, extent
,
720 btrfs_mark_buffer_dirty(leaf
);
721 } else if (key
.offset
< inline_limit
&&
722 (end
> extent_end
) &&
723 (inline_limit
< extent_end
)) {
725 new_size
= btrfs_file_extent_calc_inline_size(
726 inline_limit
- key
.offset
);
727 dec_i_blocks(inode
, (extent_end
- key
.offset
) -
728 (inline_limit
- key
.offset
));
729 btrfs_truncate_item(trans
, root
, path
,
733 /* delete the entire extent */
735 ret
= btrfs_del_item(trans
, root
, path
);
736 /* TODO update progress marker and return */
739 btrfs_release_path(root
, path
);
740 /* the extent will be freed later */
742 if (bookend
&& found_inline
&& start
<= key
.offset
) {
744 new_size
= btrfs_file_extent_calc_inline_size(
746 dec_i_blocks(inode
, (extent_end
- key
.offset
) -
748 ret
= btrfs_truncate_item(trans
, root
, path
,
752 /* create bookend, splitting the extent in two */
753 if (bookend
&& found_extent
) {
755 struct btrfs_key ins
;
756 ins
.objectid
= inode
->i_ino
;
758 btrfs_set_key_type(&ins
, BTRFS_EXTENT_DATA_KEY
);
759 btrfs_release_path(root
, path
);
760 ret
= btrfs_insert_empty_item(trans
, root
, path
, &ins
,
764 leaf
= path
->nodes
[0];
765 extent
= btrfs_item_ptr(leaf
, path
->slots
[0],
766 struct btrfs_file_extent_item
);
767 write_extent_buffer(leaf
, &old
,
768 (unsigned long)extent
, sizeof(old
));
770 btrfs_set_file_extent_offset(leaf
, extent
,
771 le64_to_cpu(old
.offset
) + end
- key
.offset
);
772 WARN_ON(le64_to_cpu(old
.num_bytes
) <
774 btrfs_set_file_extent_num_bytes(leaf
, extent
,
776 btrfs_set_file_extent_type(leaf
, extent
,
777 BTRFS_FILE_EXTENT_REG
);
779 btrfs_mark_buffer_dirty(path
->nodes
[0]);
781 disk_bytenr
= le64_to_cpu(old
.disk_bytenr
);
782 if (disk_bytenr
!= 0) {
783 ret
= btrfs_inc_extent_ref(trans
, root
,
785 le64_to_cpu(old
.disk_num_bytes
),
787 root
->root_key
.objectid
,
789 ins
.objectid
, ins
.offset
);
792 btrfs_release_path(root
, path
);
793 if (disk_bytenr
!= 0) {
795 btrfs_file_extent_num_bytes(leaf
,
800 if (found_extent
&& !keep
) {
801 u64 disk_bytenr
= le64_to_cpu(old
.disk_bytenr
);
803 if (disk_bytenr
!= 0) {
804 dec_i_blocks(inode
, le64_to_cpu(old
.num_bytes
));
805 ret
= btrfs_free_extent(trans
, root
,
807 le64_to_cpu(old
.disk_num_bytes
),
808 leaf_start
, root_owner
,
809 root_gen
, key
.objectid
,
812 *hint_byte
= disk_bytenr
;
816 if (search_start
>= end
) {
822 btrfs_free_path(path
);
823 btrfs_check_file(root
, inode
);
828 * this gets pages into the page cache and locks them down, it also properly
829 * waits for data=ordered extents to finish before allowing the pages to be
832 static int noinline
prepare_pages(struct btrfs_root
*root
, struct file
*file
,
833 struct page
**pages
, size_t num_pages
,
834 loff_t pos
, unsigned long first_index
,
835 unsigned long last_index
, size_t write_bytes
)
838 unsigned long index
= pos
>> PAGE_CACHE_SHIFT
;
839 struct inode
*inode
= fdentry(file
)->d_inode
;
844 start_pos
= pos
& ~((u64
)root
->sectorsize
- 1);
845 last_pos
= ((u64
)index
+ num_pages
) << PAGE_CACHE_SHIFT
;
847 memset(pages
, 0, num_pages
* sizeof(struct page
*));
849 for (i
= 0; i
< num_pages
; i
++) {
850 pages
[i
] = grab_cache_page(inode
->i_mapping
, index
+ i
);
855 wait_on_page_writeback(pages
[i
]);
857 if (start_pos
< inode
->i_size
) {
858 struct btrfs_ordered_extent
*ordered
;
859 lock_extent(&BTRFS_I(inode
)->io_tree
,
860 start_pos
, last_pos
- 1, GFP_NOFS
);
861 ordered
= btrfs_lookup_first_ordered_extent(inode
, last_pos
-1);
863 ordered
->file_offset
+ ordered
->len
> start_pos
&&
864 ordered
->file_offset
< last_pos
) {
865 btrfs_put_ordered_extent(ordered
);
866 unlock_extent(&BTRFS_I(inode
)->io_tree
,
867 start_pos
, last_pos
- 1, GFP_NOFS
);
868 for (i
= 0; i
< num_pages
; i
++) {
869 unlock_page(pages
[i
]);
870 page_cache_release(pages
[i
]);
872 btrfs_wait_ordered_range(inode
, start_pos
,
873 last_pos
- start_pos
);
877 btrfs_put_ordered_extent(ordered
);
879 clear_extent_bits(&BTRFS_I(inode
)->io_tree
, start_pos
,
880 last_pos
- 1, EXTENT_DIRTY
| EXTENT_DELALLOC
,
882 unlock_extent(&BTRFS_I(inode
)->io_tree
,
883 start_pos
, last_pos
- 1, GFP_NOFS
);
885 for (i
= 0; i
< num_pages
; i
++) {
886 clear_page_dirty_for_io(pages
[i
]);
887 set_page_extent_mapped(pages
[i
]);
888 WARN_ON(!PageLocked(pages
[i
]));
893 static ssize_t
btrfs_file_write(struct file
*file
, const char __user
*buf
,
894 size_t count
, loff_t
*ppos
)
898 ssize_t num_written
= 0;
901 struct inode
*inode
= fdentry(file
)->d_inode
;
902 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
903 struct page
**pages
= NULL
;
905 struct page
*pinned
[2];
906 unsigned long first_index
;
907 unsigned long last_index
;
910 will_write
= ((file
->f_flags
& O_SYNC
) || IS_SYNC(inode
) ||
911 (file
->f_flags
& O_DIRECT
));
913 nrptrs
= min((count
+ PAGE_CACHE_SIZE
- 1) / PAGE_CACHE_SIZE
,
914 PAGE_CACHE_SIZE
/ (sizeof(struct page
*)));
921 vfs_check_frozen(inode
->i_sb
, SB_FREEZE_WRITE
);
922 current
->backing_dev_info
= inode
->i_mapping
->backing_dev_info
;
923 err
= generic_write_checks(file
, &pos
, &count
, S_ISBLK(inode
->i_mode
));
929 err
= file_remove_suid(file
);
932 file_update_time(file
);
934 pages
= kmalloc(nrptrs
* sizeof(struct page
*), GFP_KERNEL
);
936 mutex_lock(&inode
->i_mutex
);
937 first_index
= pos
>> PAGE_CACHE_SHIFT
;
938 last_index
= (pos
+ count
) >> PAGE_CACHE_SHIFT
;
941 * if this is a nodatasum mount, force summing off for the inode
942 * all the time. That way a later mount with summing on won't
945 if (btrfs_test_opt(root
, NODATASUM
))
946 btrfs_set_flag(inode
, NODATASUM
);
949 * there are lots of better ways to do this, but this code
950 * makes sure the first and last page in the file range are
951 * up to date and ready for cow
953 if ((pos
& (PAGE_CACHE_SIZE
- 1))) {
954 pinned
[0] = grab_cache_page(inode
->i_mapping
, first_index
);
955 if (!PageUptodate(pinned
[0])) {
956 ret
= btrfs_readpage(NULL
, pinned
[0]);
958 wait_on_page_locked(pinned
[0]);
960 unlock_page(pinned
[0]);
963 if ((pos
+ count
) & (PAGE_CACHE_SIZE
- 1)) {
964 pinned
[1] = grab_cache_page(inode
->i_mapping
, last_index
);
965 if (!PageUptodate(pinned
[1])) {
966 ret
= btrfs_readpage(NULL
, pinned
[1]);
968 wait_on_page_locked(pinned
[1]);
970 unlock_page(pinned
[1]);
975 size_t offset
= pos
& (PAGE_CACHE_SIZE
- 1);
976 size_t write_bytes
= min(count
, nrptrs
*
977 (size_t)PAGE_CACHE_SIZE
-
979 size_t num_pages
= (write_bytes
+ PAGE_CACHE_SIZE
- 1) >>
982 WARN_ON(num_pages
> nrptrs
);
983 memset(pages
, 0, sizeof(pages
));
985 ret
= btrfs_check_free_space(root
, write_bytes
, 0);
989 ret
= prepare_pages(root
, file
, pages
, num_pages
,
990 pos
, first_index
, last_index
,
995 ret
= btrfs_copy_from_user(pos
, num_pages
,
996 write_bytes
, pages
, buf
);
998 btrfs_drop_pages(pages
, num_pages
);
1002 ret
= dirty_and_release_pages(NULL
, root
, file
, pages
,
1003 num_pages
, pos
, write_bytes
);
1004 btrfs_drop_pages(pages
, num_pages
);
1009 btrfs_fdatawrite_range(inode
->i_mapping
, pos
,
1010 pos
+ write_bytes
- 1,
1013 balance_dirty_pages_ratelimited_nr(inode
->i_mapping
,
1016 (root
->leafsize
>> PAGE_CACHE_SHIFT
) + 1)
1017 btrfs_btree_balance_dirty(root
, 1);
1018 btrfs_throttle(root
);
1022 count
-= write_bytes
;
1024 num_written
+= write_bytes
;
1029 mutex_unlock(&inode
->i_mutex
);
1034 page_cache_release(pinned
[0]);
1036 page_cache_release(pinned
[1]);
1039 if (num_written
> 0 && will_write
) {
1040 struct btrfs_trans_handle
*trans
;
1042 err
= btrfs_wait_ordered_range(inode
, start_pos
, num_written
);
1046 if ((file
->f_flags
& O_SYNC
) || IS_SYNC(inode
)) {
1047 trans
= btrfs_start_transaction(root
, 1);
1048 ret
= btrfs_log_dentry_safe(trans
, root
,
1051 btrfs_sync_log(trans
, root
);
1052 btrfs_end_transaction(trans
, root
);
1054 btrfs_commit_transaction(trans
, root
);
1057 if (file
->f_flags
& O_DIRECT
) {
1058 invalidate_mapping_pages(inode
->i_mapping
,
1059 start_pos
>> PAGE_CACHE_SHIFT
,
1060 (start_pos
+ num_written
- 1) >> PAGE_CACHE_SHIFT
);
1063 current
->backing_dev_info
= NULL
;
1064 return num_written
? num_written
: err
;
1067 int btrfs_release_file(struct inode
* inode
, struct file
* filp
)
1069 if (filp
->private_data
)
1070 btrfs_ioctl_trans_end(filp
);
1075 * fsync call for both files and directories. This logs the inode into
1076 * the tree log instead of forcing full commits whenever possible.
1078 * It needs to call filemap_fdatawait so that all ordered extent updates are
1079 * in the metadata btree are up to date for copying to the log.
1081 * It drops the inode mutex before doing the tree log commit. This is an
1082 * important optimization for directories because holding the mutex prevents
1083 * new operations on the dir while we write to disk.
1085 int btrfs_sync_file(struct file
*file
, struct dentry
*dentry
, int datasync
)
1087 struct inode
*inode
= dentry
->d_inode
;
1088 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
1090 struct btrfs_trans_handle
*trans
;
1093 * check the transaction that last modified this inode
1094 * and see if its already been committed
1096 if (!BTRFS_I(inode
)->last_trans
)
1099 mutex_lock(&root
->fs_info
->trans_mutex
);
1100 if (BTRFS_I(inode
)->last_trans
<=
1101 root
->fs_info
->last_trans_committed
) {
1102 BTRFS_I(inode
)->last_trans
= 0;
1103 mutex_unlock(&root
->fs_info
->trans_mutex
);
1106 mutex_unlock(&root
->fs_info
->trans_mutex
);
1108 root
->fs_info
->tree_log_batch
++;
1109 filemap_fdatawait(inode
->i_mapping
);
1110 root
->fs_info
->tree_log_batch
++;
1113 * ok we haven't committed the transaction yet, lets do a commit
1115 if (file
->private_data
)
1116 btrfs_ioctl_trans_end(file
);
1118 trans
= btrfs_start_transaction(root
, 1);
1124 ret
= btrfs_log_dentry_safe(trans
, root
, file
->f_dentry
);
1129 /* we've logged all the items and now have a consistent
1130 * version of the file in the log. It is possible that
1131 * someone will come in and modify the file, but that's
1132 * fine because the log is consistent on disk, and we
1133 * have references to all of the file's extents
1135 * It is possible that someone will come in and log the
1136 * file again, but that will end up using the synchronization
1137 * inside btrfs_sync_log to keep things safe.
1139 mutex_unlock(&file
->f_dentry
->d_inode
->i_mutex
);
1142 ret
= btrfs_commit_transaction(trans
, root
);
1144 btrfs_sync_log(trans
, root
);
1145 ret
= btrfs_end_transaction(trans
, root
);
1147 mutex_lock(&file
->f_dentry
->d_inode
->i_mutex
);
1149 return ret
> 0 ? EIO
: ret
;
1152 static struct vm_operations_struct btrfs_file_vm_ops
= {
1153 .fault
= filemap_fault
,
1154 .page_mkwrite
= btrfs_page_mkwrite
,
1157 static int btrfs_file_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
1159 vma
->vm_ops
= &btrfs_file_vm_ops
;
1160 file_accessed(filp
);
1164 struct file_operations btrfs_file_operations
= {
1165 .llseek
= generic_file_llseek
,
1166 .read
= do_sync_read
,
1167 .aio_read
= generic_file_aio_read
,
1168 .splice_read
= generic_file_splice_read
,
1169 .write
= btrfs_file_write
,
1170 .mmap
= btrfs_file_mmap
,
1171 .open
= generic_file_open
,
1172 .release
= btrfs_release_file
,
1173 .fsync
= btrfs_sync_file
,
1174 .unlocked_ioctl
= btrfs_ioctl
,
1175 #ifdef CONFIG_COMPAT
1176 .compat_ioctl
= btrfs_ioctl
,