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"
37 #include "ordered-data.h"
39 #include "print-tree.h"
42 static int btrfs_copy_from_user(loff_t pos
, int num_pages
, int write_bytes
,
43 struct page
**prepared_pages
,
44 const char __user
* buf
)
48 int offset
= pos
& (PAGE_CACHE_SIZE
- 1);
50 for (i
= 0; i
< num_pages
&& write_bytes
> 0; i
++, offset
= 0) {
51 size_t count
= min_t(size_t,
52 PAGE_CACHE_SIZE
- offset
, write_bytes
);
53 struct page
*page
= prepared_pages
[i
];
54 fault_in_pages_readable(buf
, count
);
56 /* Copy data from userspace to the current page */
58 page_fault
= __copy_from_user(page_address(page
) + offset
,
60 /* Flush processor's dcache for this page */
61 flush_dcache_page(page
);
69 return page_fault
? -EFAULT
: 0;
72 static void btrfs_drop_pages(struct page
**pages
, size_t num_pages
)
75 for (i
= 0; i
< num_pages
; i
++) {
78 unlock_page(pages
[i
]);
79 mark_page_accessed(pages
[i
]);
80 page_cache_release(pages
[i
]);
84 static int noinline
insert_inline_extent(struct btrfs_trans_handle
*trans
,
85 struct btrfs_root
*root
, struct inode
*inode
,
86 u64 offset
, size_t size
,
87 struct page
**pages
, size_t page_offset
,
91 struct btrfs_path
*path
;
92 struct extent_buffer
*leaf
;
95 struct btrfs_file_extent_item
*ei
;
103 path
= btrfs_alloc_path();
107 btrfs_set_trans_block_group(trans
, inode
);
109 key
.objectid
= inode
->i_ino
;
111 btrfs_set_key_type(&key
, BTRFS_EXTENT_DATA_KEY
);
113 ret
= btrfs_search_slot(trans
, root
, &key
, path
, 0, 1);
119 struct btrfs_key found_key
;
121 if (path
->slots
[0] == 0)
125 leaf
= path
->nodes
[0];
126 btrfs_item_key_to_cpu(leaf
, &found_key
, path
->slots
[0]);
128 if (found_key
.objectid
!= inode
->i_ino
)
131 if (found_key
.type
!= BTRFS_EXTENT_DATA_KEY
)
133 ei
= btrfs_item_ptr(leaf
, path
->slots
[0],
134 struct btrfs_file_extent_item
);
136 if (btrfs_file_extent_type(leaf
, ei
) !=
137 BTRFS_FILE_EXTENT_INLINE
) {
140 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
147 leaf
= path
->nodes
[0];
148 ei
= btrfs_item_ptr(leaf
, path
->slots
[0],
149 struct btrfs_file_extent_item
);
151 if (btrfs_file_extent_type(leaf
, ei
) !=
152 BTRFS_FILE_EXTENT_INLINE
) {
154 btrfs_print_leaf(root
, leaf
);
155 printk("found wasn't inline offset %Lu inode %lu\n",
156 offset
, inode
->i_ino
);
159 found_size
= btrfs_file_extent_inline_len(leaf
,
160 btrfs_item_nr(leaf
, path
->slots
[0]));
161 found_end
= key
.offset
+ found_size
;
163 if (found_end
< offset
+ size
) {
164 btrfs_release_path(root
, path
);
165 ret
= btrfs_search_slot(trans
, root
, &key
, path
,
166 offset
+ size
- found_end
, 1);
169 ret
= btrfs_extend_item(trans
, root
, path
,
170 offset
+ size
- found_end
);
175 leaf
= path
->nodes
[0];
176 ei
= btrfs_item_ptr(leaf
, path
->slots
[0],
177 struct btrfs_file_extent_item
);
178 inode
->i_blocks
+= (offset
+ size
- found_end
) >> 9;
180 if (found_end
< offset
) {
181 ptr
= btrfs_file_extent_inline_start(ei
) + found_size
;
182 memset_extent_buffer(leaf
, 0, ptr
, offset
- found_end
);
186 btrfs_release_path(root
, path
);
187 datasize
= offset
+ size
- key
.offset
;
188 inode
->i_blocks
+= datasize
>> 9;
189 datasize
= btrfs_file_extent_calc_inline_size(datasize
);
190 ret
= btrfs_insert_empty_item(trans
, root
, path
, &key
,
194 printk("got bad ret %d\n", ret
);
197 leaf
= path
->nodes
[0];
198 ei
= btrfs_item_ptr(leaf
, path
->slots
[0],
199 struct btrfs_file_extent_item
);
200 btrfs_set_file_extent_generation(leaf
, ei
, trans
->transid
);
201 btrfs_set_file_extent_type(leaf
, ei
, BTRFS_FILE_EXTENT_INLINE
);
203 ptr
= btrfs_file_extent_inline_start(ei
) + offset
- key
.offset
;
209 kaddr
= kmap_atomic(page
, KM_USER0
);
210 cur_size
= min_t(size_t, PAGE_CACHE_SIZE
- page_offset
, size
);
211 write_extent_buffer(leaf
, kaddr
+ page_offset
, ptr
, cur_size
);
212 kunmap_atomic(kaddr
, KM_USER0
);
216 if (i
>= num_pages
) {
217 printk("i %d num_pages %d\n", i
, num_pages
);
221 btrfs_mark_buffer_dirty(leaf
);
223 btrfs_free_path(path
);
227 static int noinline
dirty_and_release_pages(struct btrfs_trans_handle
*trans
,
228 struct btrfs_root
*root
,
237 struct inode
*inode
= fdentry(file
)->d_inode
;
238 struct extent_io_tree
*io_tree
= &BTRFS_I(inode
)->io_tree
;
242 u64 end_of_last_block
;
243 u64 end_pos
= pos
+ write_bytes
;
245 loff_t isize
= i_size_read(inode
);
247 start_pos
= pos
& ~((u64
)root
->sectorsize
- 1);
248 num_bytes
= (write_bytes
+ pos
- start_pos
+
249 root
->sectorsize
- 1) & ~((u64
)root
->sectorsize
- 1);
251 end_of_last_block
= start_pos
+ num_bytes
- 1;
253 lock_extent(io_tree
, start_pos
, end_of_last_block
, GFP_NOFS
);
254 mutex_lock(&root
->fs_info
->fs_mutex
);
255 trans
= btrfs_start_transaction(root
, 1);
260 btrfs_set_trans_block_group(trans
, inode
);
263 if ((end_of_last_block
& 4095) == 0) {
264 printk("strange end of last %Lu %zu %Lu\n", start_pos
, write_bytes
, end_of_last_block
);
266 set_extent_uptodate(io_tree
, start_pos
, end_of_last_block
, GFP_NOFS
);
268 /* FIXME...EIEIO, ENOSPC and more */
269 /* insert any holes we need to create */
270 if (isize
< end_pos
) {
271 u64 last_pos_in_file
;
273 u64 mask
= root
->sectorsize
- 1;
274 last_pos_in_file
= (isize
+ mask
) & ~mask
;
275 hole_size
= (end_pos
- last_pos_in_file
+ mask
) & ~mask
;
276 if (last_pos_in_file
< end_pos
) {
277 err
= btrfs_drop_extents(trans
, root
, inode
,
279 last_pos_in_file
+ hole_size
,
285 err
= btrfs_insert_file_extent(trans
, root
,
289 btrfs_drop_extent_cache(inode
, last_pos_in_file
,
290 last_pos_in_file
+ hole_size
-1);
291 btrfs_check_file(root
, inode
);
298 * either allocate an extent for the new bytes or setup the key
299 * to show we are doing inline data in the extent
301 inline_size
= end_pos
;
302 if (isize
>= BTRFS_MAX_INLINE_DATA_SIZE(root
) ||
303 inline_size
> root
->fs_info
->max_inline
||
304 (inline_size
& (root
->sectorsize
-1)) == 0 ||
305 inline_size
>= BTRFS_MAX_INLINE_DATA_SIZE(root
)) {
307 u64 existing_delalloc
= 0;
309 for (i
= 0; i
< num_pages
; i
++) {
310 struct page
*p
= pages
[i
];
314 last_end
= (u64
)(pages
[num_pages
-1]->index
) <<
316 last_end
+= PAGE_CACHE_SIZE
- 1;
317 if (start_pos
< isize
) {
318 u64 delalloc_start
= start_pos
;
319 existing_delalloc
= count_range_bits(io_tree
,
321 end_of_last_block
, (u64
)-1,
324 set_extent_delalloc(io_tree
, start_pos
, end_of_last_block
,
326 btrfs_add_ordered_inode(inode
);
329 /* step one, delete the existing extents in this range */
330 aligned_end
= (pos
+ write_bytes
+ root
->sectorsize
- 1) &
331 ~((u64
)root
->sectorsize
- 1);
332 err
= btrfs_drop_extents(trans
, root
, inode
, start_pos
,
333 aligned_end
, aligned_end
, &hint_byte
);
336 if (isize
> inline_size
)
337 inline_size
= min_t(u64
, isize
, aligned_end
);
338 inline_size
-= start_pos
;
339 err
= insert_inline_extent(trans
, root
, inode
, start_pos
,
340 inline_size
, pages
, 0, num_pages
);
341 btrfs_drop_extent_cache(inode
, start_pos
, aligned_end
- 1);
344 if (end_pos
> isize
) {
345 i_size_write(inode
, end_pos
);
346 btrfs_update_inode(trans
, root
, inode
);
349 err
= btrfs_end_transaction(trans
, root
);
351 mutex_unlock(&root
->fs_info
->fs_mutex
);
352 unlock_extent(io_tree
, start_pos
, end_of_last_block
, GFP_NOFS
);
356 int btrfs_drop_extent_cache(struct inode
*inode
, u64 start
, u64 end
)
358 struct extent_map
*em
;
359 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
360 u64 len
= end
- start
+ 1;
365 spin_lock(&em_tree
->lock
);
366 em
= lookup_extent_mapping(em_tree
, start
, len
);
368 spin_unlock(&em_tree
->lock
);
371 remove_extent_mapping(em_tree
, em
);
372 spin_unlock(&em_tree
->lock
);
376 /* once for the tree*/
382 int btrfs_check_file(struct btrfs_root
*root
, struct inode
*inode
)
386 struct btrfs_path
*path
;
387 struct btrfs_key found_key
;
388 struct extent_buffer
*leaf
;
389 struct btrfs_file_extent_item
*extent
;
398 path
= btrfs_alloc_path();
399 ret
= btrfs_lookup_file_extent(NULL
, root
, path
, inode
->i_ino
,
402 nritems
= btrfs_header_nritems(path
->nodes
[0]);
403 if (path
->slots
[0] >= nritems
) {
404 ret
= btrfs_next_leaf(root
, path
);
407 nritems
= btrfs_header_nritems(path
->nodes
[0]);
409 slot
= path
->slots
[0];
410 leaf
= path
->nodes
[0];
411 btrfs_item_key_to_cpu(leaf
, &found_key
, slot
);
412 if (found_key
.objectid
!= inode
->i_ino
)
414 if (found_key
.type
!= BTRFS_EXTENT_DATA_KEY
)
417 if (found_key
.offset
< last_offset
) {
419 btrfs_print_leaf(root
, leaf
);
420 printk("inode %lu found offset %Lu expected %Lu\n",
421 inode
->i_ino
, found_key
.offset
, last_offset
);
425 extent
= btrfs_item_ptr(leaf
, slot
,
426 struct btrfs_file_extent_item
);
427 found_type
= btrfs_file_extent_type(leaf
, extent
);
428 if (found_type
== BTRFS_FILE_EXTENT_REG
) {
429 extent_end
= found_key
.offset
+
430 btrfs_file_extent_num_bytes(leaf
, extent
);
431 } else if (found_type
== BTRFS_FILE_EXTENT_INLINE
) {
432 struct btrfs_item
*item
;
433 item
= btrfs_item_nr(leaf
, slot
);
434 extent_end
= found_key
.offset
+
435 btrfs_file_extent_inline_len(leaf
, item
);
436 extent_end
= (extent_end
+ root
->sectorsize
- 1) &
437 ~((u64
)root
->sectorsize
-1 );
439 last_offset
= extent_end
;
442 if (0 && last_offset
< inode
->i_size
) {
444 btrfs_print_leaf(root
, leaf
);
445 printk("inode %lu found offset %Lu size %Lu\n", inode
->i_ino
,
446 last_offset
, inode
->i_size
);
451 btrfs_free_path(path
);
457 * this is very complex, but the basic idea is to drop all extents
458 * in the range start - end. hint_block is filled in with a block number
459 * that would be a good hint to the block allocator for this file.
461 * If an extent intersects the range but is not entirely inside the range
462 * it is either truncated or split. Anything entirely inside the range
463 * is deleted from the tree.
465 int btrfs_drop_extents(struct btrfs_trans_handle
*trans
,
466 struct btrfs_root
*root
, struct inode
*inode
,
467 u64 start
, u64 end
, u64 inline_limit
, u64
*hint_byte
)
470 u64 search_start
= start
;
471 struct extent_buffer
*leaf
;
472 struct btrfs_file_extent_item
*extent
;
473 struct btrfs_path
*path
;
474 struct btrfs_key key
;
475 struct btrfs_file_extent_item old
;
485 btrfs_drop_extent_cache(inode
, start
, end
- 1);
487 path
= btrfs_alloc_path();
492 btrfs_release_path(root
, path
);
493 ret
= btrfs_lookup_file_extent(trans
, root
, path
, inode
->i_ino
,
498 if (path
->slots
[0] == 0) {
510 leaf
= path
->nodes
[0];
511 slot
= path
->slots
[0];
513 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
514 if (btrfs_key_type(&key
) == BTRFS_EXTENT_DATA_KEY
&&
518 if (btrfs_key_type(&key
) > BTRFS_EXTENT_DATA_KEY
||
519 key
.objectid
!= inode
->i_ino
) {
523 search_start
= key
.offset
;
526 if (btrfs_key_type(&key
) == BTRFS_EXTENT_DATA_KEY
) {
527 extent
= btrfs_item_ptr(leaf
, slot
,
528 struct btrfs_file_extent_item
);
529 found_type
= btrfs_file_extent_type(leaf
, extent
);
530 if (found_type
== BTRFS_FILE_EXTENT_REG
) {
532 btrfs_file_extent_disk_bytenr(leaf
,
535 *hint_byte
= extent_end
;
537 extent_end
= key
.offset
+
538 btrfs_file_extent_num_bytes(leaf
, extent
);
540 } else if (found_type
== BTRFS_FILE_EXTENT_INLINE
) {
541 struct btrfs_item
*item
;
542 item
= btrfs_item_nr(leaf
, slot
);
544 extent_end
= key
.offset
+
545 btrfs_file_extent_inline_len(leaf
, item
);
548 extent_end
= search_start
;
551 /* we found nothing we can drop */
552 if ((!found_extent
&& !found_inline
) ||
553 search_start
>= extent_end
) {
556 nritems
= btrfs_header_nritems(leaf
);
557 if (slot
>= nritems
- 1) {
558 nextret
= btrfs_next_leaf(root
, path
);
569 u64 mask
= root
->sectorsize
- 1;
570 search_start
= (extent_end
+ mask
) & ~mask
;
572 search_start
= extent_end
;
573 if (end
<= extent_end
&& start
>= key
.offset
&& found_inline
) {
574 *hint_byte
= EXTENT_MAP_INLINE
;
577 if (end
< extent_end
&& end
>= key
.offset
) {
580 btrfs_file_extent_disk_bytenr(leaf
, extent
);
582 btrfs_file_extent_disk_num_bytes(leaf
,
584 read_extent_buffer(leaf
, &old
,
585 (unsigned long)extent
,
587 if (disk_bytenr
!= 0) {
588 ret
= btrfs_inc_extent_ref(trans
, root
,
589 disk_bytenr
, disk_num_bytes
,
590 root
->root_key
.objectid
,
597 if (found_inline
&& start
<= key
.offset
)
600 /* truncate existing extent */
601 if (start
> key
.offset
) {
605 WARN_ON(start
& (root
->sectorsize
- 1));
607 new_num
= start
- key
.offset
;
608 old_num
= btrfs_file_extent_num_bytes(leaf
,
611 btrfs_file_extent_disk_bytenr(leaf
,
613 if (btrfs_file_extent_disk_bytenr(leaf
,
615 dec_i_blocks(inode
, old_num
- new_num
);
617 btrfs_set_file_extent_num_bytes(leaf
, extent
,
619 btrfs_mark_buffer_dirty(leaf
);
620 } else if (key
.offset
< inline_limit
&&
621 (end
> extent_end
) &&
622 (inline_limit
< extent_end
)) {
624 new_size
= btrfs_file_extent_calc_inline_size(
625 inline_limit
- key
.offset
);
626 dec_i_blocks(inode
, (extent_end
- key
.offset
) -
627 (inline_limit
- key
.offset
));
628 btrfs_truncate_item(trans
, root
, path
,
632 /* delete the entire extent */
635 u64 disk_num_bytes
= 0;
636 u64 extent_num_bytes
= 0;
640 root_gen
= btrfs_header_generation(leaf
);
641 root_owner
= btrfs_header_owner(leaf
);
644 btrfs_file_extent_disk_bytenr(leaf
,
647 btrfs_file_extent_disk_num_bytes(leaf
,
650 btrfs_file_extent_num_bytes(leaf
, extent
);
652 btrfs_file_extent_disk_bytenr(leaf
,
655 ret
= btrfs_del_item(trans
, root
, path
);
656 /* TODO update progress marker and return */
658 btrfs_release_path(root
, path
);
660 if (found_extent
&& disk_bytenr
!= 0) {
661 dec_i_blocks(inode
, extent_num_bytes
);
662 ret
= btrfs_free_extent(trans
, root
,
666 root_gen
, inode
->i_ino
,
671 if (!bookend
&& search_start
>= end
) {
678 if (bookend
&& found_inline
&& start
<= key
.offset
) {
680 new_size
= btrfs_file_extent_calc_inline_size(
682 dec_i_blocks(inode
, (extent_end
- key
.offset
) -
684 btrfs_truncate_item(trans
, root
, path
, new_size
, 0);
686 /* create bookend, splitting the extent in two */
687 if (bookend
&& found_extent
) {
688 struct btrfs_key ins
;
689 ins
.objectid
= inode
->i_ino
;
691 btrfs_set_key_type(&ins
, BTRFS_EXTENT_DATA_KEY
);
692 btrfs_release_path(root
, path
);
693 ret
= btrfs_insert_empty_item(trans
, root
, path
, &ins
,
696 leaf
= path
->nodes
[0];
698 btrfs_print_leaf(root
, leaf
);
699 printk("got %d on inserting %Lu %u %Lu start %Lu end %Lu found %Lu %Lu keep was %d\n", ret
, ins
.objectid
, ins
.type
, ins
.offset
, start
, end
, key
.offset
, extent_end
, keep
);
702 extent
= btrfs_item_ptr(leaf
, path
->slots
[0],
703 struct btrfs_file_extent_item
);
704 write_extent_buffer(leaf
, &old
,
705 (unsigned long)extent
, sizeof(old
));
707 btrfs_set_file_extent_offset(leaf
, extent
,
708 le64_to_cpu(old
.offset
) + end
- key
.offset
);
709 WARN_ON(le64_to_cpu(old
.num_bytes
) <
711 btrfs_set_file_extent_num_bytes(leaf
, extent
,
713 btrfs_set_file_extent_type(leaf
, extent
,
714 BTRFS_FILE_EXTENT_REG
);
716 btrfs_mark_buffer_dirty(path
->nodes
[0]);
717 if (le64_to_cpu(old
.disk_bytenr
) != 0) {
719 btrfs_file_extent_num_bytes(leaf
,
727 btrfs_free_path(path
);
728 btrfs_check_file(root
, inode
);
733 * this gets pages into the page cache and locks them down
735 static int prepare_pages(struct btrfs_root
*root
, struct file
*file
,
736 struct page
**pages
, size_t num_pages
,
737 loff_t pos
, unsigned long first_index
,
738 unsigned long last_index
, size_t write_bytes
)
741 unsigned long index
= pos
>> PAGE_CACHE_SHIFT
;
742 struct inode
*inode
= fdentry(file
)->d_inode
;
746 start_pos
= pos
& ~((u64
)root
->sectorsize
- 1);
748 memset(pages
, 0, num_pages
* sizeof(struct page
*));
750 for (i
= 0; i
< num_pages
; i
++) {
751 pages
[i
] = grab_cache_page(inode
->i_mapping
, index
+ i
);
756 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
757 ClearPageDirty(pages
[i
]);
759 cancel_dirty_page(pages
[i
], PAGE_CACHE_SIZE
);
761 wait_on_page_writeback(pages
[i
]);
762 set_page_extent_mapped(pages
[i
]);
763 WARN_ON(!PageLocked(pages
[i
]));
765 if (start_pos
< inode
->i_size
) {
767 last_pos
= (index
+ num_pages
) << PAGE_CACHE_SHIFT
;
768 lock_extent(&BTRFS_I(inode
)->io_tree
,
769 start_pos
, last_pos
- 1, GFP_NOFS
);
770 clear_extent_bits(&BTRFS_I(inode
)->io_tree
, start_pos
,
771 last_pos
- 1, EXTENT_DIRTY
| EXTENT_DELALLOC
,
773 unlock_extent(&BTRFS_I(inode
)->io_tree
,
774 start_pos
, last_pos
- 1, GFP_NOFS
);
779 static ssize_t
btrfs_file_write(struct file
*file
, const char __user
*buf
,
780 size_t count
, loff_t
*ppos
)
784 ssize_t num_written
= 0;
787 struct inode
*inode
= fdentry(file
)->d_inode
;
788 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
789 struct page
**pages
= NULL
;
791 struct page
*pinned
[2];
792 unsigned long first_index
;
793 unsigned long last_index
;
795 nrptrs
= min((count
+ PAGE_CACHE_SIZE
- 1) / PAGE_CACHE_SIZE
,
796 PAGE_CACHE_SIZE
/ (sizeof(struct page
*)));
799 if (file
->f_flags
& O_DIRECT
)
805 vfs_check_frozen(inode
->i_sb
, SB_FREEZE_WRITE
);
806 current
->backing_dev_info
= inode
->i_mapping
->backing_dev_info
;
807 err
= generic_write_checks(file
, &pos
, &count
, S_ISBLK(inode
->i_mode
));
812 err
= remove_suid(fdentry(file
));
815 file_update_time(file
);
817 pages
= kmalloc(nrptrs
* sizeof(struct page
*), GFP_KERNEL
);
819 mutex_lock(&inode
->i_mutex
);
820 first_index
= pos
>> PAGE_CACHE_SHIFT
;
821 last_index
= (pos
+ count
) >> PAGE_CACHE_SHIFT
;
824 * there are lots of better ways to do this, but this code
825 * makes sure the first and last page in the file range are
826 * up to date and ready for cow
828 if ((pos
& (PAGE_CACHE_SIZE
- 1))) {
829 pinned
[0] = grab_cache_page(inode
->i_mapping
, first_index
);
830 if (!PageUptodate(pinned
[0])) {
831 ret
= btrfs_readpage(NULL
, pinned
[0]);
833 wait_on_page_locked(pinned
[0]);
835 unlock_page(pinned
[0]);
838 if ((pos
+ count
) & (PAGE_CACHE_SIZE
- 1)) {
839 pinned
[1] = grab_cache_page(inode
->i_mapping
, last_index
);
840 if (!PageUptodate(pinned
[1])) {
841 ret
= btrfs_readpage(NULL
, pinned
[1]);
843 wait_on_page_locked(pinned
[1]);
845 unlock_page(pinned
[1]);
850 size_t offset
= pos
& (PAGE_CACHE_SIZE
- 1);
851 size_t write_bytes
= min(count
, nrptrs
*
852 (size_t)PAGE_CACHE_SIZE
-
854 size_t num_pages
= (write_bytes
+ PAGE_CACHE_SIZE
- 1) >>
857 WARN_ON(num_pages
> nrptrs
);
858 memset(pages
, 0, sizeof(pages
));
860 mutex_lock(&root
->fs_info
->fs_mutex
);
861 ret
= btrfs_check_free_space(root
, write_bytes
, 0);
862 mutex_unlock(&root
->fs_info
->fs_mutex
);
866 ret
= prepare_pages(root
, file
, pages
, num_pages
,
867 pos
, first_index
, last_index
,
872 ret
= btrfs_copy_from_user(pos
, num_pages
,
873 write_bytes
, pages
, buf
);
875 btrfs_drop_pages(pages
, num_pages
);
879 ret
= dirty_and_release_pages(NULL
, root
, file
, pages
,
880 num_pages
, pos
, write_bytes
);
881 btrfs_drop_pages(pages
, num_pages
);
886 count
-= write_bytes
;
888 num_written
+= write_bytes
;
890 balance_dirty_pages_ratelimited_nr(inode
->i_mapping
, num_pages
);
891 if (num_pages
< (root
->leafsize
>> PAGE_CACHE_SHIFT
) + 1)
892 btrfs_btree_balance_dirty(root
, 1);
893 btrfs_throttle(root
);
897 mutex_unlock(&inode
->i_mutex
);
902 page_cache_release(pinned
[0]);
904 page_cache_release(pinned
[1]);
907 if (num_written
> 0 && ((file
->f_flags
& O_SYNC
) || IS_SYNC(inode
))) {
908 err
= sync_page_range(inode
, inode
->i_mapping
,
909 start_pos
, num_written
);
913 current
->backing_dev_info
= NULL
;
914 return num_written
? num_written
: err
;
917 static int btrfs_sync_file(struct file
*file
,
918 struct dentry
*dentry
, int datasync
)
920 struct inode
*inode
= dentry
->d_inode
;
921 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
923 struct btrfs_trans_handle
*trans
;
926 * check the transaction that last modified this inode
927 * and see if its already been committed
929 mutex_lock(&root
->fs_info
->fs_mutex
);
930 if (!BTRFS_I(inode
)->last_trans
)
932 mutex_lock(&root
->fs_info
->trans_mutex
);
933 if (BTRFS_I(inode
)->last_trans
<=
934 root
->fs_info
->last_trans_committed
) {
935 BTRFS_I(inode
)->last_trans
= 0;
936 mutex_unlock(&root
->fs_info
->trans_mutex
);
939 mutex_unlock(&root
->fs_info
->trans_mutex
);
942 * ok we haven't committed the transaction yet, lets do a commit
944 trans
= btrfs_start_transaction(root
, 1);
949 ret
= btrfs_commit_transaction(trans
, root
);
951 mutex_unlock(&root
->fs_info
->fs_mutex
);
952 return ret
> 0 ? EIO
: ret
;
955 static struct vm_operations_struct btrfs_file_vm_ops
= {
956 #if LINUX_VERSION_CODE < KERNEL_VERSION(2,6,23)
957 .nopage
= filemap_nopage
,
958 .populate
= filemap_populate
,
960 .fault
= filemap_fault
,
962 .page_mkwrite
= btrfs_page_mkwrite
,
965 static int btrfs_file_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
967 vma
->vm_ops
= &btrfs_file_vm_ops
;
972 struct file_operations btrfs_file_operations
= {
973 .llseek
= generic_file_llseek
,
974 .read
= do_sync_read
,
975 .aio_read
= generic_file_aio_read
,
976 .splice_read
= generic_file_splice_read
,
977 #if LINUX_VERSION_CODE <= KERNEL_VERSION(2,6,18)
978 .sendfile
= generic_file_sendfile
,
980 .write
= btrfs_file_write
,
981 .mmap
= btrfs_file_mmap
,
982 .open
= generic_file_open
,
983 .fsync
= btrfs_sync_file
,
984 .unlocked_ioctl
= btrfs_ioctl
,
986 .compat_ioctl
= btrfs_ioctl
,