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/backing-dev.h>
26 #include <linux/mpage.h>
27 #include <linux/falloc.h>
28 #include <linux/swap.h>
29 #include <linux/writeback.h>
30 #include <linux/statfs.h>
31 #include <linux/compat.h>
32 #include <linux/slab.h>
35 #include "transaction.h"
36 #include "btrfs_inode.h"
38 #include "print-tree.h"
44 * when auto defrag is enabled we
45 * queue up these defrag structs to remember which
46 * inodes need defragging passes
49 struct rb_node rb_node
;
53 * transid where the defrag was added, we search for
54 * extents newer than this
61 /* last offset we were able to defrag */
64 /* if we've wrapped around back to zero once already */
68 /* pop a record for an inode into the defrag tree. The lock
69 * must be held already
71 * If you're inserting a record for an older transid than an
72 * existing record, the transid already in the tree is lowered
74 * If an existing record is found the defrag item you
77 static void __btrfs_add_inode_defrag(struct inode
*inode
,
78 struct inode_defrag
*defrag
)
80 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
81 struct inode_defrag
*entry
;
83 struct rb_node
*parent
= NULL
;
85 p
= &root
->fs_info
->defrag_inodes
.rb_node
;
88 entry
= rb_entry(parent
, struct inode_defrag
, rb_node
);
90 if (defrag
->ino
< entry
->ino
)
92 else if (defrag
->ino
> entry
->ino
)
93 p
= &parent
->rb_right
;
95 /* if we're reinserting an entry for
96 * an old defrag run, make sure to
97 * lower the transid of our existing record
99 if (defrag
->transid
< entry
->transid
)
100 entry
->transid
= defrag
->transid
;
101 if (defrag
->last_offset
> entry
->last_offset
)
102 entry
->last_offset
= defrag
->last_offset
;
106 BTRFS_I(inode
)->in_defrag
= 1;
107 rb_link_node(&defrag
->rb_node
, parent
, p
);
108 rb_insert_color(&defrag
->rb_node
, &root
->fs_info
->defrag_inodes
);
118 * insert a defrag record for this inode if auto defrag is
121 int btrfs_add_inode_defrag(struct btrfs_trans_handle
*trans
,
124 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
125 struct inode_defrag
*defrag
;
128 if (!btrfs_test_opt(root
, AUTO_DEFRAG
))
131 if (btrfs_fs_closing(root
->fs_info
))
134 if (BTRFS_I(inode
)->in_defrag
)
138 transid
= trans
->transid
;
140 transid
= BTRFS_I(inode
)->root
->last_trans
;
142 defrag
= kzalloc(sizeof(*defrag
), GFP_NOFS
);
146 defrag
->ino
= btrfs_ino(inode
);
147 defrag
->transid
= transid
;
148 defrag
->root
= root
->root_key
.objectid
;
150 spin_lock(&root
->fs_info
->defrag_inodes_lock
);
151 if (!BTRFS_I(inode
)->in_defrag
)
152 __btrfs_add_inode_defrag(inode
, defrag
);
155 spin_unlock(&root
->fs_info
->defrag_inodes_lock
);
160 * must be called with the defrag_inodes lock held
162 struct inode_defrag
*btrfs_find_defrag_inode(struct btrfs_fs_info
*info
, u64 ino
,
163 struct rb_node
**next
)
165 struct inode_defrag
*entry
= NULL
;
167 struct rb_node
*parent
= NULL
;
169 p
= info
->defrag_inodes
.rb_node
;
172 entry
= rb_entry(parent
, struct inode_defrag
, rb_node
);
174 if (ino
< entry
->ino
)
176 else if (ino
> entry
->ino
)
177 p
= parent
->rb_right
;
183 while (parent
&& ino
> entry
->ino
) {
184 parent
= rb_next(parent
);
185 entry
= rb_entry(parent
, struct inode_defrag
, rb_node
);
193 * run through the list of inodes in the FS that need
196 int btrfs_run_defrag_inodes(struct btrfs_fs_info
*fs_info
)
198 struct inode_defrag
*defrag
;
199 struct btrfs_root
*inode_root
;
202 struct btrfs_key key
;
203 struct btrfs_ioctl_defrag_range_args range
;
206 int defrag_batch
= 1024;
208 memset(&range
, 0, sizeof(range
));
211 atomic_inc(&fs_info
->defrag_running
);
212 spin_lock(&fs_info
->defrag_inodes_lock
);
216 /* find an inode to defrag */
217 defrag
= btrfs_find_defrag_inode(fs_info
, first_ino
, &n
);
220 defrag
= rb_entry(n
, struct inode_defrag
, rb_node
);
221 else if (first_ino
) {
229 /* remove it from the rbtree */
230 first_ino
= defrag
->ino
+ 1;
231 rb_erase(&defrag
->rb_node
, &fs_info
->defrag_inodes
);
233 if (btrfs_fs_closing(fs_info
))
236 spin_unlock(&fs_info
->defrag_inodes_lock
);
239 key
.objectid
= defrag
->root
;
240 btrfs_set_key_type(&key
, BTRFS_ROOT_ITEM_KEY
);
241 key
.offset
= (u64
)-1;
242 inode_root
= btrfs_read_fs_root_no_name(fs_info
, &key
);
243 if (IS_ERR(inode_root
))
246 key
.objectid
= defrag
->ino
;
247 btrfs_set_key_type(&key
, BTRFS_INODE_ITEM_KEY
);
250 inode
= btrfs_iget(fs_info
->sb
, &key
, inode_root
, NULL
);
254 /* do a chunk of defrag */
255 BTRFS_I(inode
)->in_defrag
= 0;
256 range
.start
= defrag
->last_offset
;
257 num_defrag
= btrfs_defrag_file(inode
, NULL
, &range
, defrag
->transid
,
260 * if we filled the whole defrag batch, there
261 * must be more work to do. Queue this defrag
264 if (num_defrag
== defrag_batch
) {
265 defrag
->last_offset
= range
.start
;
266 __btrfs_add_inode_defrag(inode
, defrag
);
268 * we don't want to kfree defrag, we added it back to
272 } else if (defrag
->last_offset
&& !defrag
->cycled
) {
274 * we didn't fill our defrag batch, but
275 * we didn't start at zero. Make sure we loop
276 * around to the start of the file.
278 defrag
->last_offset
= 0;
280 __btrfs_add_inode_defrag(inode
, defrag
);
286 spin_lock(&fs_info
->defrag_inodes_lock
);
290 spin_unlock(&fs_info
->defrag_inodes_lock
);
292 atomic_dec(&fs_info
->defrag_running
);
295 * during unmount, we use the transaction_wait queue to
296 * wait for the defragger to stop
298 wake_up(&fs_info
->transaction_wait
);
302 /* simple helper to fault in pages and copy. This should go away
303 * and be replaced with calls into generic code.
305 static noinline
int btrfs_copy_from_user(loff_t pos
, int num_pages
,
307 struct page
**prepared_pages
,
311 size_t total_copied
= 0;
313 int offset
= pos
& (PAGE_CACHE_SIZE
- 1);
315 while (write_bytes
> 0) {
316 size_t count
= min_t(size_t,
317 PAGE_CACHE_SIZE
- offset
, write_bytes
);
318 struct page
*page
= prepared_pages
[pg
];
320 * Copy data from userspace to the current page
322 * Disable pagefault to avoid recursive lock since
323 * the pages are already locked
326 copied
= iov_iter_copy_from_user_atomic(page
, i
, offset
, count
);
329 /* Flush processor's dcache for this page */
330 flush_dcache_page(page
);
333 * if we get a partial write, we can end up with
334 * partially up to date pages. These add
335 * a lot of complexity, so make sure they don't
336 * happen by forcing this copy to be retried.
338 * The rest of the btrfs_file_write code will fall
339 * back to page at a time copies after we return 0.
341 if (!PageUptodate(page
) && copied
< count
)
344 iov_iter_advance(i
, copied
);
345 write_bytes
-= copied
;
346 total_copied
+= copied
;
348 /* Return to btrfs_file_aio_write to fault page */
349 if (unlikely(copied
== 0))
352 if (unlikely(copied
< PAGE_CACHE_SIZE
- offset
)) {
363 * unlocks pages after btrfs_file_write is done with them
365 void btrfs_drop_pages(struct page
**pages
, size_t num_pages
)
368 for (i
= 0; i
< num_pages
; i
++) {
369 /* page checked is some magic around finding pages that
370 * have been modified without going through btrfs_set_page_dirty
373 ClearPageChecked(pages
[i
]);
374 unlock_page(pages
[i
]);
375 mark_page_accessed(pages
[i
]);
376 page_cache_release(pages
[i
]);
381 * after copy_from_user, pages need to be dirtied and we need to make
382 * sure holes are created between the current EOF and the start of
383 * any next extents (if required).
385 * this also makes the decision about creating an inline extent vs
386 * doing real data extents, marking pages dirty and delalloc as required.
388 int btrfs_dirty_pages(struct btrfs_root
*root
, struct inode
*inode
,
389 struct page
**pages
, size_t num_pages
,
390 loff_t pos
, size_t write_bytes
,
391 struct extent_state
**cached
)
397 u64 end_of_last_block
;
398 u64 end_pos
= pos
+ write_bytes
;
399 loff_t isize
= i_size_read(inode
);
401 start_pos
= pos
& ~((u64
)root
->sectorsize
- 1);
402 num_bytes
= (write_bytes
+ pos
- start_pos
+
403 root
->sectorsize
- 1) & ~((u64
)root
->sectorsize
- 1);
405 end_of_last_block
= start_pos
+ num_bytes
- 1;
406 err
= btrfs_set_extent_delalloc(inode
, start_pos
, end_of_last_block
,
411 for (i
= 0; i
< num_pages
; i
++) {
412 struct page
*p
= pages
[i
];
419 * we've only changed i_size in ram, and we haven't updated
420 * the disk i_size. There is no need to log the inode
424 i_size_write(inode
, end_pos
);
429 * this drops all the extents in the cache that intersect the range
430 * [start, end]. Existing extents are split as required.
432 int btrfs_drop_extent_cache(struct inode
*inode
, u64 start
, u64 end
,
435 struct extent_map
*em
;
436 struct extent_map
*split
= NULL
;
437 struct extent_map
*split2
= NULL
;
438 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
439 u64 len
= end
- start
+ 1;
445 WARN_ON(end
< start
);
446 if (end
== (u64
)-1) {
452 split
= alloc_extent_map();
454 split2
= alloc_extent_map();
455 BUG_ON(!split
|| !split2
); /* -ENOMEM */
457 write_lock(&em_tree
->lock
);
458 em
= lookup_extent_mapping(em_tree
, start
, len
);
460 write_unlock(&em_tree
->lock
);
464 if (skip_pinned
&& test_bit(EXTENT_FLAG_PINNED
, &em
->flags
)) {
465 if (testend
&& em
->start
+ em
->len
>= start
+ len
) {
467 write_unlock(&em_tree
->lock
);
470 start
= em
->start
+ em
->len
;
472 len
= start
+ len
- (em
->start
+ em
->len
);
474 write_unlock(&em_tree
->lock
);
477 compressed
= test_bit(EXTENT_FLAG_COMPRESSED
, &em
->flags
);
478 clear_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
479 remove_extent_mapping(em_tree
, em
);
481 if (em
->block_start
< EXTENT_MAP_LAST_BYTE
&&
483 split
->start
= em
->start
;
484 split
->len
= start
- em
->start
;
485 split
->orig_start
= em
->orig_start
;
486 split
->block_start
= em
->block_start
;
489 split
->block_len
= em
->block_len
;
491 split
->block_len
= split
->len
;
493 split
->bdev
= em
->bdev
;
494 split
->flags
= flags
;
495 split
->compress_type
= em
->compress_type
;
496 ret
= add_extent_mapping(em_tree
, split
);
497 BUG_ON(ret
); /* Logic error */
498 free_extent_map(split
);
502 if (em
->block_start
< EXTENT_MAP_LAST_BYTE
&&
503 testend
&& em
->start
+ em
->len
> start
+ len
) {
504 u64 diff
= start
+ len
- em
->start
;
506 split
->start
= start
+ len
;
507 split
->len
= em
->start
+ em
->len
- (start
+ len
);
508 split
->bdev
= em
->bdev
;
509 split
->flags
= flags
;
510 split
->compress_type
= em
->compress_type
;
513 split
->block_len
= em
->block_len
;
514 split
->block_start
= em
->block_start
;
515 split
->orig_start
= em
->orig_start
;
517 split
->block_len
= split
->len
;
518 split
->block_start
= em
->block_start
+ diff
;
519 split
->orig_start
= split
->start
;
522 ret
= add_extent_mapping(em_tree
, split
);
523 BUG_ON(ret
); /* Logic error */
524 free_extent_map(split
);
527 write_unlock(&em_tree
->lock
);
531 /* once for the tree*/
535 free_extent_map(split
);
537 free_extent_map(split2
);
542 * this is very complex, but the basic idea is to drop all extents
543 * in the range start - end. hint_block is filled in with a block number
544 * that would be a good hint to the block allocator for this file.
546 * If an extent intersects the range but is not entirely inside the range
547 * it is either truncated or split. Anything entirely inside the range
548 * is deleted from the tree.
550 int btrfs_drop_extents(struct btrfs_trans_handle
*trans
, struct inode
*inode
,
551 u64 start
, u64 end
, u64
*hint_byte
, int drop_cache
)
553 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
554 struct extent_buffer
*leaf
;
555 struct btrfs_file_extent_item
*fi
;
556 struct btrfs_path
*path
;
557 struct btrfs_key key
;
558 struct btrfs_key new_key
;
559 u64 ino
= btrfs_ino(inode
);
560 u64 search_start
= start
;
563 u64 extent_offset
= 0;
570 int modify_tree
= -1;
573 btrfs_drop_extent_cache(inode
, start
, end
- 1, 0);
575 path
= btrfs_alloc_path();
579 if (start
>= BTRFS_I(inode
)->disk_i_size
)
584 ret
= btrfs_lookup_file_extent(trans
, root
, path
, ino
,
585 search_start
, modify_tree
);
588 if (ret
> 0 && path
->slots
[0] > 0 && search_start
== start
) {
589 leaf
= path
->nodes
[0];
590 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0] - 1);
591 if (key
.objectid
== ino
&&
592 key
.type
== BTRFS_EXTENT_DATA_KEY
)
597 leaf
= path
->nodes
[0];
598 if (path
->slots
[0] >= btrfs_header_nritems(leaf
)) {
600 ret
= btrfs_next_leaf(root
, path
);
607 leaf
= path
->nodes
[0];
611 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
612 if (key
.objectid
> ino
||
613 key
.type
> BTRFS_EXTENT_DATA_KEY
|| key
.offset
>= end
)
616 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
617 struct btrfs_file_extent_item
);
618 extent_type
= btrfs_file_extent_type(leaf
, fi
);
620 if (extent_type
== BTRFS_FILE_EXTENT_REG
||
621 extent_type
== BTRFS_FILE_EXTENT_PREALLOC
) {
622 disk_bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
623 num_bytes
= btrfs_file_extent_disk_num_bytes(leaf
, fi
);
624 extent_offset
= btrfs_file_extent_offset(leaf
, fi
);
625 extent_end
= key
.offset
+
626 btrfs_file_extent_num_bytes(leaf
, fi
);
627 } else if (extent_type
== BTRFS_FILE_EXTENT_INLINE
) {
628 extent_end
= key
.offset
+
629 btrfs_file_extent_inline_len(leaf
, fi
);
632 extent_end
= search_start
;
635 if (extent_end
<= search_start
) {
640 search_start
= max(key
.offset
, start
);
641 if (recow
|| !modify_tree
) {
643 btrfs_release_path(path
);
648 * | - range to drop - |
649 * | -------- extent -------- |
651 if (start
> key
.offset
&& end
< extent_end
) {
653 BUG_ON(extent_type
== BTRFS_FILE_EXTENT_INLINE
);
655 memcpy(&new_key
, &key
, sizeof(new_key
));
656 new_key
.offset
= start
;
657 ret
= btrfs_duplicate_item(trans
, root
, path
,
659 if (ret
== -EAGAIN
) {
660 btrfs_release_path(path
);
666 leaf
= path
->nodes
[0];
667 fi
= btrfs_item_ptr(leaf
, path
->slots
[0] - 1,
668 struct btrfs_file_extent_item
);
669 btrfs_set_file_extent_num_bytes(leaf
, fi
,
672 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
673 struct btrfs_file_extent_item
);
675 extent_offset
+= start
- key
.offset
;
676 btrfs_set_file_extent_offset(leaf
, fi
, extent_offset
);
677 btrfs_set_file_extent_num_bytes(leaf
, fi
,
679 btrfs_mark_buffer_dirty(leaf
);
681 if (disk_bytenr
> 0) {
682 ret
= btrfs_inc_extent_ref(trans
, root
,
683 disk_bytenr
, num_bytes
, 0,
684 root
->root_key
.objectid
,
686 start
- extent_offset
, 0);
687 BUG_ON(ret
); /* -ENOMEM */
688 *hint_byte
= disk_bytenr
;
693 * | ---- range to drop ----- |
694 * | -------- extent -------- |
696 if (start
<= key
.offset
&& end
< extent_end
) {
697 BUG_ON(extent_type
== BTRFS_FILE_EXTENT_INLINE
);
699 memcpy(&new_key
, &key
, sizeof(new_key
));
700 new_key
.offset
= end
;
701 btrfs_set_item_key_safe(trans
, root
, path
, &new_key
);
703 extent_offset
+= end
- key
.offset
;
704 btrfs_set_file_extent_offset(leaf
, fi
, extent_offset
);
705 btrfs_set_file_extent_num_bytes(leaf
, fi
,
707 btrfs_mark_buffer_dirty(leaf
);
708 if (disk_bytenr
> 0) {
709 inode_sub_bytes(inode
, end
- key
.offset
);
710 *hint_byte
= disk_bytenr
;
715 search_start
= extent_end
;
717 * | ---- range to drop ----- |
718 * | -------- extent -------- |
720 if (start
> key
.offset
&& end
>= extent_end
) {
722 BUG_ON(extent_type
== BTRFS_FILE_EXTENT_INLINE
);
724 btrfs_set_file_extent_num_bytes(leaf
, fi
,
726 btrfs_mark_buffer_dirty(leaf
);
727 if (disk_bytenr
> 0) {
728 inode_sub_bytes(inode
, extent_end
- start
);
729 *hint_byte
= disk_bytenr
;
731 if (end
== extent_end
)
739 * | ---- range to drop ----- |
740 * | ------ extent ------ |
742 if (start
<= key
.offset
&& end
>= extent_end
) {
744 del_slot
= path
->slots
[0];
747 BUG_ON(del_slot
+ del_nr
!= path
->slots
[0]);
751 if (extent_type
== BTRFS_FILE_EXTENT_INLINE
) {
752 inode_sub_bytes(inode
,
753 extent_end
- key
.offset
);
754 extent_end
= ALIGN(extent_end
,
756 } else if (disk_bytenr
> 0) {
757 ret
= btrfs_free_extent(trans
, root
,
758 disk_bytenr
, num_bytes
, 0,
759 root
->root_key
.objectid
,
760 key
.objectid
, key
.offset
-
762 BUG_ON(ret
); /* -ENOMEM */
763 inode_sub_bytes(inode
,
764 extent_end
- key
.offset
);
765 *hint_byte
= disk_bytenr
;
768 if (end
== extent_end
)
771 if (path
->slots
[0] + 1 < btrfs_header_nritems(leaf
)) {
776 ret
= btrfs_del_items(trans
, root
, path
, del_slot
,
779 btrfs_abort_transaction(trans
, root
, ret
);
786 btrfs_release_path(path
);
793 if (!ret
&& del_nr
> 0) {
794 ret
= btrfs_del_items(trans
, root
, path
, del_slot
, del_nr
);
796 btrfs_abort_transaction(trans
, root
, ret
);
800 btrfs_free_path(path
);
804 static int extent_mergeable(struct extent_buffer
*leaf
, int slot
,
805 u64 objectid
, u64 bytenr
, u64 orig_offset
,
806 u64
*start
, u64
*end
)
808 struct btrfs_file_extent_item
*fi
;
809 struct btrfs_key key
;
812 if (slot
< 0 || slot
>= btrfs_header_nritems(leaf
))
815 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
816 if (key
.objectid
!= objectid
|| key
.type
!= BTRFS_EXTENT_DATA_KEY
)
819 fi
= btrfs_item_ptr(leaf
, slot
, struct btrfs_file_extent_item
);
820 if (btrfs_file_extent_type(leaf
, fi
) != BTRFS_FILE_EXTENT_REG
||
821 btrfs_file_extent_disk_bytenr(leaf
, fi
) != bytenr
||
822 btrfs_file_extent_offset(leaf
, fi
) != key
.offset
- orig_offset
||
823 btrfs_file_extent_compression(leaf
, fi
) ||
824 btrfs_file_extent_encryption(leaf
, fi
) ||
825 btrfs_file_extent_other_encoding(leaf
, fi
))
828 extent_end
= key
.offset
+ btrfs_file_extent_num_bytes(leaf
, fi
);
829 if ((*start
&& *start
!= key
.offset
) || (*end
&& *end
!= extent_end
))
838 * Mark extent in the range start - end as written.
840 * This changes extent type from 'pre-allocated' to 'regular'. If only
841 * part of extent is marked as written, the extent will be split into
844 int btrfs_mark_extent_written(struct btrfs_trans_handle
*trans
,
845 struct inode
*inode
, u64 start
, u64 end
)
847 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
848 struct extent_buffer
*leaf
;
849 struct btrfs_path
*path
;
850 struct btrfs_file_extent_item
*fi
;
851 struct btrfs_key key
;
852 struct btrfs_key new_key
;
864 u64 ino
= btrfs_ino(inode
);
866 btrfs_drop_extent_cache(inode
, start
, end
- 1, 0);
868 path
= btrfs_alloc_path();
875 key
.type
= BTRFS_EXTENT_DATA_KEY
;
878 ret
= btrfs_search_slot(trans
, root
, &key
, path
, -1, 1);
881 if (ret
> 0 && path
->slots
[0] > 0)
884 leaf
= path
->nodes
[0];
885 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
886 BUG_ON(key
.objectid
!= ino
|| key
.type
!= BTRFS_EXTENT_DATA_KEY
);
887 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
888 struct btrfs_file_extent_item
);
889 BUG_ON(btrfs_file_extent_type(leaf
, fi
) !=
890 BTRFS_FILE_EXTENT_PREALLOC
);
891 extent_end
= key
.offset
+ btrfs_file_extent_num_bytes(leaf
, fi
);
892 BUG_ON(key
.offset
> start
|| extent_end
< end
);
894 bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
895 num_bytes
= btrfs_file_extent_disk_num_bytes(leaf
, fi
);
896 orig_offset
= key
.offset
- btrfs_file_extent_offset(leaf
, fi
);
897 memcpy(&new_key
, &key
, sizeof(new_key
));
899 if (start
== key
.offset
&& end
< extent_end
) {
902 if (extent_mergeable(leaf
, path
->slots
[0] - 1,
903 ino
, bytenr
, orig_offset
,
904 &other_start
, &other_end
)) {
905 new_key
.offset
= end
;
906 btrfs_set_item_key_safe(trans
, root
, path
, &new_key
);
907 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
908 struct btrfs_file_extent_item
);
909 btrfs_set_file_extent_num_bytes(leaf
, fi
,
911 btrfs_set_file_extent_offset(leaf
, fi
,
913 fi
= btrfs_item_ptr(leaf
, path
->slots
[0] - 1,
914 struct btrfs_file_extent_item
);
915 btrfs_set_file_extent_num_bytes(leaf
, fi
,
917 btrfs_mark_buffer_dirty(leaf
);
922 if (start
> key
.offset
&& end
== extent_end
) {
925 if (extent_mergeable(leaf
, path
->slots
[0] + 1,
926 ino
, bytenr
, orig_offset
,
927 &other_start
, &other_end
)) {
928 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
929 struct btrfs_file_extent_item
);
930 btrfs_set_file_extent_num_bytes(leaf
, fi
,
933 new_key
.offset
= start
;
934 btrfs_set_item_key_safe(trans
, root
, path
, &new_key
);
936 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
937 struct btrfs_file_extent_item
);
938 btrfs_set_file_extent_num_bytes(leaf
, fi
,
940 btrfs_set_file_extent_offset(leaf
, fi
,
941 start
- orig_offset
);
942 btrfs_mark_buffer_dirty(leaf
);
947 while (start
> key
.offset
|| end
< extent_end
) {
948 if (key
.offset
== start
)
951 new_key
.offset
= split
;
952 ret
= btrfs_duplicate_item(trans
, root
, path
, &new_key
);
953 if (ret
== -EAGAIN
) {
954 btrfs_release_path(path
);
958 btrfs_abort_transaction(trans
, root
, ret
);
962 leaf
= path
->nodes
[0];
963 fi
= btrfs_item_ptr(leaf
, path
->slots
[0] - 1,
964 struct btrfs_file_extent_item
);
965 btrfs_set_file_extent_num_bytes(leaf
, fi
,
968 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
969 struct btrfs_file_extent_item
);
971 btrfs_set_file_extent_offset(leaf
, fi
, split
- orig_offset
);
972 btrfs_set_file_extent_num_bytes(leaf
, fi
,
974 btrfs_mark_buffer_dirty(leaf
);
976 ret
= btrfs_inc_extent_ref(trans
, root
, bytenr
, num_bytes
, 0,
977 root
->root_key
.objectid
,
978 ino
, orig_offset
, 0);
979 BUG_ON(ret
); /* -ENOMEM */
981 if (split
== start
) {
984 BUG_ON(start
!= key
.offset
);
993 if (extent_mergeable(leaf
, path
->slots
[0] + 1,
994 ino
, bytenr
, orig_offset
,
995 &other_start
, &other_end
)) {
997 btrfs_release_path(path
);
1000 extent_end
= other_end
;
1001 del_slot
= path
->slots
[0] + 1;
1003 ret
= btrfs_free_extent(trans
, root
, bytenr
, num_bytes
,
1004 0, root
->root_key
.objectid
,
1005 ino
, orig_offset
, 0);
1006 BUG_ON(ret
); /* -ENOMEM */
1010 if (extent_mergeable(leaf
, path
->slots
[0] - 1,
1011 ino
, bytenr
, orig_offset
,
1012 &other_start
, &other_end
)) {
1014 btrfs_release_path(path
);
1017 key
.offset
= other_start
;
1018 del_slot
= path
->slots
[0];
1020 ret
= btrfs_free_extent(trans
, root
, bytenr
, num_bytes
,
1021 0, root
->root_key
.objectid
,
1022 ino
, orig_offset
, 0);
1023 BUG_ON(ret
); /* -ENOMEM */
1026 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
1027 struct btrfs_file_extent_item
);
1028 btrfs_set_file_extent_type(leaf
, fi
,
1029 BTRFS_FILE_EXTENT_REG
);
1030 btrfs_mark_buffer_dirty(leaf
);
1032 fi
= btrfs_item_ptr(leaf
, del_slot
- 1,
1033 struct btrfs_file_extent_item
);
1034 btrfs_set_file_extent_type(leaf
, fi
,
1035 BTRFS_FILE_EXTENT_REG
);
1036 btrfs_set_file_extent_num_bytes(leaf
, fi
,
1037 extent_end
- key
.offset
);
1038 btrfs_mark_buffer_dirty(leaf
);
1040 ret
= btrfs_del_items(trans
, root
, path
, del_slot
, del_nr
);
1042 btrfs_abort_transaction(trans
, root
, ret
);
1047 btrfs_free_path(path
);
1052 * on error we return an unlocked page and the error value
1053 * on success we return a locked page and 0
1055 static int prepare_uptodate_page(struct page
*page
, u64 pos
,
1056 bool force_uptodate
)
1060 if (((pos
& (PAGE_CACHE_SIZE
- 1)) || force_uptodate
) &&
1061 !PageUptodate(page
)) {
1062 ret
= btrfs_readpage(NULL
, page
);
1066 if (!PageUptodate(page
)) {
1075 * this gets pages into the page cache and locks them down, it also properly
1076 * waits for data=ordered extents to finish before allowing the pages to be
1079 static noinline
int prepare_pages(struct btrfs_root
*root
, struct file
*file
,
1080 struct page
**pages
, size_t num_pages
,
1081 loff_t pos
, unsigned long first_index
,
1082 size_t write_bytes
, bool force_uptodate
)
1084 struct extent_state
*cached_state
= NULL
;
1086 unsigned long index
= pos
>> PAGE_CACHE_SHIFT
;
1087 struct inode
*inode
= fdentry(file
)->d_inode
;
1088 gfp_t mask
= btrfs_alloc_write_mask(inode
->i_mapping
);
1094 start_pos
= pos
& ~((u64
)root
->sectorsize
- 1);
1095 last_pos
= ((u64
)index
+ num_pages
) << PAGE_CACHE_SHIFT
;
1098 for (i
= 0; i
< num_pages
; i
++) {
1099 pages
[i
] = find_or_create_page(inode
->i_mapping
, index
+ i
,
1100 mask
| __GFP_WRITE
);
1108 err
= prepare_uptodate_page(pages
[i
], pos
,
1110 if (i
== num_pages
- 1)
1111 err
= prepare_uptodate_page(pages
[i
],
1112 pos
+ write_bytes
, false);
1114 page_cache_release(pages
[i
]);
1118 wait_on_page_writeback(pages
[i
]);
1121 if (start_pos
< inode
->i_size
) {
1122 struct btrfs_ordered_extent
*ordered
;
1123 lock_extent_bits(&BTRFS_I(inode
)->io_tree
,
1124 start_pos
, last_pos
- 1, 0, &cached_state
);
1125 ordered
= btrfs_lookup_first_ordered_extent(inode
,
1128 ordered
->file_offset
+ ordered
->len
> start_pos
&&
1129 ordered
->file_offset
< last_pos
) {
1130 btrfs_put_ordered_extent(ordered
);
1131 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
,
1132 start_pos
, last_pos
- 1,
1133 &cached_state
, GFP_NOFS
);
1134 for (i
= 0; i
< num_pages
; i
++) {
1135 unlock_page(pages
[i
]);
1136 page_cache_release(pages
[i
]);
1138 btrfs_wait_ordered_range(inode
, start_pos
,
1139 last_pos
- start_pos
);
1143 btrfs_put_ordered_extent(ordered
);
1145 clear_extent_bit(&BTRFS_I(inode
)->io_tree
, start_pos
,
1146 last_pos
- 1, EXTENT_DIRTY
| EXTENT_DELALLOC
|
1147 EXTENT_DO_ACCOUNTING
, 0, 0, &cached_state
,
1149 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
,
1150 start_pos
, last_pos
- 1, &cached_state
,
1153 for (i
= 0; i
< num_pages
; i
++) {
1154 if (clear_page_dirty_for_io(pages
[i
]))
1155 account_page_redirty(pages
[i
]);
1156 set_page_extent_mapped(pages
[i
]);
1157 WARN_ON(!PageLocked(pages
[i
]));
1161 while (faili
>= 0) {
1162 unlock_page(pages
[faili
]);
1163 page_cache_release(pages
[faili
]);
1170 static noinline ssize_t
__btrfs_buffered_write(struct file
*file
,
1174 struct inode
*inode
= fdentry(file
)->d_inode
;
1175 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
1176 struct page
**pages
= NULL
;
1177 unsigned long first_index
;
1178 size_t num_written
= 0;
1181 bool force_page_uptodate
= false;
1183 nrptrs
= min((iov_iter_count(i
) + PAGE_CACHE_SIZE
- 1) /
1184 PAGE_CACHE_SIZE
, PAGE_CACHE_SIZE
/
1185 (sizeof(struct page
*)));
1186 nrptrs
= min(nrptrs
, current
->nr_dirtied_pause
- current
->nr_dirtied
);
1187 nrptrs
= max(nrptrs
, 8);
1188 pages
= kmalloc(nrptrs
* sizeof(struct page
*), GFP_KERNEL
);
1192 first_index
= pos
>> PAGE_CACHE_SHIFT
;
1194 while (iov_iter_count(i
) > 0) {
1195 size_t offset
= pos
& (PAGE_CACHE_SIZE
- 1);
1196 size_t write_bytes
= min(iov_iter_count(i
),
1197 nrptrs
* (size_t)PAGE_CACHE_SIZE
-
1199 size_t num_pages
= (write_bytes
+ offset
+
1200 PAGE_CACHE_SIZE
- 1) >> PAGE_CACHE_SHIFT
;
1204 WARN_ON(num_pages
> nrptrs
);
1207 * Fault pages before locking them in prepare_pages
1208 * to avoid recursive lock
1210 if (unlikely(iov_iter_fault_in_readable(i
, write_bytes
))) {
1215 ret
= btrfs_delalloc_reserve_space(inode
,
1216 num_pages
<< PAGE_CACHE_SHIFT
);
1221 * This is going to setup the pages array with the number of
1222 * pages we want, so we don't really need to worry about the
1223 * contents of pages from loop to loop
1225 ret
= prepare_pages(root
, file
, pages
, num_pages
,
1226 pos
, first_index
, write_bytes
,
1227 force_page_uptodate
);
1229 btrfs_delalloc_release_space(inode
,
1230 num_pages
<< PAGE_CACHE_SHIFT
);
1234 copied
= btrfs_copy_from_user(pos
, num_pages
,
1235 write_bytes
, pages
, i
);
1238 * if we have trouble faulting in the pages, fall
1239 * back to one page at a time
1241 if (copied
< write_bytes
)
1245 force_page_uptodate
= true;
1248 force_page_uptodate
= false;
1249 dirty_pages
= (copied
+ offset
+
1250 PAGE_CACHE_SIZE
- 1) >>
1255 * If we had a short copy we need to release the excess delaloc
1256 * bytes we reserved. We need to increment outstanding_extents
1257 * because btrfs_delalloc_release_space will decrement it, but
1258 * we still have an outstanding extent for the chunk we actually
1261 if (num_pages
> dirty_pages
) {
1263 spin_lock(&BTRFS_I(inode
)->lock
);
1264 BTRFS_I(inode
)->outstanding_extents
++;
1265 spin_unlock(&BTRFS_I(inode
)->lock
);
1267 btrfs_delalloc_release_space(inode
,
1268 (num_pages
- dirty_pages
) <<
1273 ret
= btrfs_dirty_pages(root
, inode
, pages
,
1274 dirty_pages
, pos
, copied
,
1277 btrfs_delalloc_release_space(inode
,
1278 dirty_pages
<< PAGE_CACHE_SHIFT
);
1279 btrfs_drop_pages(pages
, num_pages
);
1284 btrfs_drop_pages(pages
, num_pages
);
1288 balance_dirty_pages_ratelimited_nr(inode
->i_mapping
,
1290 if (dirty_pages
< (root
->leafsize
>> PAGE_CACHE_SHIFT
) + 1)
1291 btrfs_btree_balance_dirty(root
, 1);
1294 num_written
+= copied
;
1299 return num_written
? num_written
: ret
;
1302 static ssize_t
__btrfs_direct_write(struct kiocb
*iocb
,
1303 const struct iovec
*iov
,
1304 unsigned long nr_segs
, loff_t pos
,
1305 loff_t
*ppos
, size_t count
, size_t ocount
)
1307 struct file
*file
= iocb
->ki_filp
;
1308 struct inode
*inode
= fdentry(file
)->d_inode
;
1311 ssize_t written_buffered
;
1315 written
= generic_file_direct_write(iocb
, iov
, &nr_segs
, pos
, ppos
,
1319 * the generic O_DIRECT will update in-memory i_size after the
1320 * DIOs are done. But our endio handlers that update the on
1321 * disk i_size never update past the in memory i_size. So we
1322 * need one more update here to catch any additions to the
1325 if (inode
->i_size
!= BTRFS_I(inode
)->disk_i_size
) {
1326 btrfs_ordered_update_i_size(inode
, inode
->i_size
, NULL
);
1327 mark_inode_dirty(inode
);
1330 if (written
< 0 || written
== count
)
1335 iov_iter_init(&i
, iov
, nr_segs
, count
, written
);
1336 written_buffered
= __btrfs_buffered_write(file
, &i
, pos
);
1337 if (written_buffered
< 0) {
1338 err
= written_buffered
;
1341 endbyte
= pos
+ written_buffered
- 1;
1342 err
= filemap_write_and_wait_range(file
->f_mapping
, pos
, endbyte
);
1345 written
+= written_buffered
;
1346 *ppos
= pos
+ written_buffered
;
1347 invalidate_mapping_pages(file
->f_mapping
, pos
>> PAGE_CACHE_SHIFT
,
1348 endbyte
>> PAGE_CACHE_SHIFT
);
1350 return written
? written
: err
;
1353 static ssize_t
btrfs_file_aio_write(struct kiocb
*iocb
,
1354 const struct iovec
*iov
,
1355 unsigned long nr_segs
, loff_t pos
)
1357 struct file
*file
= iocb
->ki_filp
;
1358 struct inode
*inode
= fdentry(file
)->d_inode
;
1359 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
1360 loff_t
*ppos
= &iocb
->ki_pos
;
1362 ssize_t num_written
= 0;
1364 size_t count
, ocount
;
1366 vfs_check_frozen(inode
->i_sb
, SB_FREEZE_WRITE
);
1368 mutex_lock(&inode
->i_mutex
);
1370 err
= generic_segment_checks(iov
, &nr_segs
, &ocount
, VERIFY_READ
);
1372 mutex_unlock(&inode
->i_mutex
);
1377 current
->backing_dev_info
= inode
->i_mapping
->backing_dev_info
;
1378 err
= generic_write_checks(file
, &pos
, &count
, S_ISBLK(inode
->i_mode
));
1380 mutex_unlock(&inode
->i_mutex
);
1385 mutex_unlock(&inode
->i_mutex
);
1389 err
= file_remove_suid(file
);
1391 mutex_unlock(&inode
->i_mutex
);
1396 * If BTRFS flips readonly due to some impossible error
1397 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1398 * although we have opened a file as writable, we have
1399 * to stop this write operation to ensure FS consistency.
1401 if (root
->fs_info
->fs_state
& BTRFS_SUPER_FLAG_ERROR
) {
1402 mutex_unlock(&inode
->i_mutex
);
1407 err
= btrfs_update_time(file
);
1409 mutex_unlock(&inode
->i_mutex
);
1412 BTRFS_I(inode
)->sequence
++;
1414 start_pos
= round_down(pos
, root
->sectorsize
);
1415 if (start_pos
> i_size_read(inode
)) {
1416 err
= btrfs_cont_expand(inode
, i_size_read(inode
), start_pos
);
1418 mutex_unlock(&inode
->i_mutex
);
1423 if (unlikely(file
->f_flags
& O_DIRECT
)) {
1424 num_written
= __btrfs_direct_write(iocb
, iov
, nr_segs
,
1425 pos
, ppos
, count
, ocount
);
1429 iov_iter_init(&i
, iov
, nr_segs
, count
, num_written
);
1431 num_written
= __btrfs_buffered_write(file
, &i
, pos
);
1432 if (num_written
> 0)
1433 *ppos
= pos
+ num_written
;
1436 mutex_unlock(&inode
->i_mutex
);
1439 * we want to make sure fsync finds this change
1440 * but we haven't joined a transaction running right now.
1442 * Later on, someone is sure to update the inode and get the
1443 * real transid recorded.
1445 * We set last_trans now to the fs_info generation + 1,
1446 * this will either be one more than the running transaction
1447 * or the generation used for the next transaction if there isn't
1448 * one running right now.
1450 BTRFS_I(inode
)->last_trans
= root
->fs_info
->generation
+ 1;
1451 if (num_written
> 0 || num_written
== -EIOCBQUEUED
) {
1452 err
= generic_write_sync(file
, pos
, num_written
);
1453 if (err
< 0 && num_written
> 0)
1457 current
->backing_dev_info
= NULL
;
1458 return num_written
? num_written
: err
;
1461 int btrfs_release_file(struct inode
*inode
, struct file
*filp
)
1464 * ordered_data_close is set by settattr when we are about to truncate
1465 * a file from a non-zero size to a zero size. This tries to
1466 * flush down new bytes that may have been written if the
1467 * application were using truncate to replace a file in place.
1469 if (BTRFS_I(inode
)->ordered_data_close
) {
1470 BTRFS_I(inode
)->ordered_data_close
= 0;
1471 btrfs_add_ordered_operation(NULL
, BTRFS_I(inode
)->root
, inode
);
1472 if (inode
->i_size
> BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT
)
1473 filemap_flush(inode
->i_mapping
);
1475 if (filp
->private_data
)
1476 btrfs_ioctl_trans_end(filp
);
1481 * fsync call for both files and directories. This logs the inode into
1482 * the tree log instead of forcing full commits whenever possible.
1484 * It needs to call filemap_fdatawait so that all ordered extent updates are
1485 * in the metadata btree are up to date for copying to the log.
1487 * It drops the inode mutex before doing the tree log commit. This is an
1488 * important optimization for directories because holding the mutex prevents
1489 * new operations on the dir while we write to disk.
1491 int btrfs_sync_file(struct file
*file
, loff_t start
, loff_t end
, int datasync
)
1493 struct dentry
*dentry
= file
->f_path
.dentry
;
1494 struct inode
*inode
= dentry
->d_inode
;
1495 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
1497 struct btrfs_trans_handle
*trans
;
1499 trace_btrfs_sync_file(file
, datasync
);
1501 ret
= filemap_write_and_wait_range(inode
->i_mapping
, start
, end
);
1504 mutex_lock(&inode
->i_mutex
);
1506 /* we wait first, since the writeback may change the inode */
1508 btrfs_wait_ordered_range(inode
, 0, (u64
)-1);
1512 * check the transaction that last modified this inode
1513 * and see if its already been committed
1515 if (!BTRFS_I(inode
)->last_trans
) {
1516 mutex_unlock(&inode
->i_mutex
);
1521 * if the last transaction that changed this file was before
1522 * the current transaction, we can bail out now without any
1526 if (BTRFS_I(inode
)->last_trans
<=
1527 root
->fs_info
->last_trans_committed
) {
1528 BTRFS_I(inode
)->last_trans
= 0;
1529 mutex_unlock(&inode
->i_mutex
);
1534 * ok we haven't committed the transaction yet, lets do a commit
1536 if (file
->private_data
)
1537 btrfs_ioctl_trans_end(file
);
1539 trans
= btrfs_start_transaction(root
, 0);
1540 if (IS_ERR(trans
)) {
1541 ret
= PTR_ERR(trans
);
1542 mutex_unlock(&inode
->i_mutex
);
1546 ret
= btrfs_log_dentry_safe(trans
, root
, dentry
);
1548 mutex_unlock(&inode
->i_mutex
);
1552 /* we've logged all the items and now have a consistent
1553 * version of the file in the log. It is possible that
1554 * someone will come in and modify the file, but that's
1555 * fine because the log is consistent on disk, and we
1556 * have references to all of the file's extents
1558 * It is possible that someone will come in and log the
1559 * file again, but that will end up using the synchronization
1560 * inside btrfs_sync_log to keep things safe.
1562 mutex_unlock(&inode
->i_mutex
);
1564 if (ret
!= BTRFS_NO_LOG_SYNC
) {
1566 ret
= btrfs_commit_transaction(trans
, root
);
1568 ret
= btrfs_sync_log(trans
, root
);
1570 ret
= btrfs_end_transaction(trans
, root
);
1572 ret
= btrfs_commit_transaction(trans
, root
);
1575 ret
= btrfs_end_transaction(trans
, root
);
1578 return ret
> 0 ? -EIO
: ret
;
1581 static const struct vm_operations_struct btrfs_file_vm_ops
= {
1582 .fault
= filemap_fault
,
1583 .page_mkwrite
= btrfs_page_mkwrite
,
1586 static int btrfs_file_mmap(struct file
*filp
, struct vm_area_struct
*vma
)
1588 struct address_space
*mapping
= filp
->f_mapping
;
1590 if (!mapping
->a_ops
->readpage
)
1593 file_accessed(filp
);
1594 vma
->vm_ops
= &btrfs_file_vm_ops
;
1595 vma
->vm_flags
|= VM_CAN_NONLINEAR
;
1600 static long btrfs_fallocate(struct file
*file
, int mode
,
1601 loff_t offset
, loff_t len
)
1603 struct inode
*inode
= file
->f_path
.dentry
->d_inode
;
1604 struct extent_state
*cached_state
= NULL
;
1611 u64 mask
= BTRFS_I(inode
)->root
->sectorsize
- 1;
1612 struct extent_map
*em
;
1615 alloc_start
= offset
& ~mask
;
1616 alloc_end
= (offset
+ len
+ mask
) & ~mask
;
1618 /* We only support the FALLOC_FL_KEEP_SIZE mode */
1619 if (mode
& ~FALLOC_FL_KEEP_SIZE
)
1623 * Make sure we have enough space before we do the
1626 ret
= btrfs_check_data_free_space(inode
, len
);
1631 * wait for ordered IO before we have any locks. We'll loop again
1632 * below with the locks held.
1634 btrfs_wait_ordered_range(inode
, alloc_start
, alloc_end
- alloc_start
);
1636 mutex_lock(&inode
->i_mutex
);
1637 ret
= inode_newsize_ok(inode
, alloc_end
);
1641 if (alloc_start
> inode
->i_size
) {
1642 ret
= btrfs_cont_expand(inode
, i_size_read(inode
),
1648 locked_end
= alloc_end
- 1;
1650 struct btrfs_ordered_extent
*ordered
;
1652 /* the extent lock is ordered inside the running
1655 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, alloc_start
,
1656 locked_end
, 0, &cached_state
);
1657 ordered
= btrfs_lookup_first_ordered_extent(inode
,
1660 ordered
->file_offset
+ ordered
->len
> alloc_start
&&
1661 ordered
->file_offset
< alloc_end
) {
1662 btrfs_put_ordered_extent(ordered
);
1663 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
,
1664 alloc_start
, locked_end
,
1665 &cached_state
, GFP_NOFS
);
1667 * we can't wait on the range with the transaction
1668 * running or with the extent lock held
1670 btrfs_wait_ordered_range(inode
, alloc_start
,
1671 alloc_end
- alloc_start
);
1674 btrfs_put_ordered_extent(ordered
);
1679 cur_offset
= alloc_start
;
1683 em
= btrfs_get_extent(inode
, NULL
, 0, cur_offset
,
1684 alloc_end
- cur_offset
, 0);
1685 if (IS_ERR_OR_NULL(em
)) {
1692 last_byte
= min(extent_map_end(em
), alloc_end
);
1693 actual_end
= min_t(u64
, extent_map_end(em
), offset
+ len
);
1694 last_byte
= (last_byte
+ mask
) & ~mask
;
1696 if (em
->block_start
== EXTENT_MAP_HOLE
||
1697 (cur_offset
>= inode
->i_size
&&
1698 !test_bit(EXTENT_FLAG_PREALLOC
, &em
->flags
))) {
1699 ret
= btrfs_prealloc_file_range(inode
, mode
, cur_offset
,
1700 last_byte
- cur_offset
,
1701 1 << inode
->i_blkbits
,
1706 free_extent_map(em
);
1709 } else if (actual_end
> inode
->i_size
&&
1710 !(mode
& FALLOC_FL_KEEP_SIZE
)) {
1712 * We didn't need to allocate any more space, but we
1713 * still extended the size of the file so we need to
1716 inode
->i_ctime
= CURRENT_TIME
;
1717 i_size_write(inode
, actual_end
);
1718 btrfs_ordered_update_i_size(inode
, actual_end
, NULL
);
1720 free_extent_map(em
);
1722 cur_offset
= last_byte
;
1723 if (cur_offset
>= alloc_end
) {
1728 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, alloc_start
, locked_end
,
1729 &cached_state
, GFP_NOFS
);
1731 mutex_unlock(&inode
->i_mutex
);
1732 /* Let go of our reservation. */
1733 btrfs_free_reserved_data_space(inode
, len
);
1737 static int find_desired_extent(struct inode
*inode
, loff_t
*offset
, int origin
)
1739 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
1740 struct extent_map
*em
;
1741 struct extent_state
*cached_state
= NULL
;
1742 u64 lockstart
= *offset
;
1743 u64 lockend
= i_size_read(inode
);
1744 u64 start
= *offset
;
1745 u64 orig_start
= *offset
;
1746 u64 len
= i_size_read(inode
);
1750 lockend
= max_t(u64
, root
->sectorsize
, lockend
);
1751 if (lockend
<= lockstart
)
1752 lockend
= lockstart
+ root
->sectorsize
;
1754 len
= lockend
- lockstart
+ 1;
1756 len
= max_t(u64
, len
, root
->sectorsize
);
1757 if (inode
->i_size
== 0)
1760 lock_extent_bits(&BTRFS_I(inode
)->io_tree
, lockstart
, lockend
, 0,
1764 * Delalloc is such a pain. If we have a hole and we have pending
1765 * delalloc for a portion of the hole we will get back a hole that
1766 * exists for the entire range since it hasn't been actually written
1767 * yet. So to take care of this case we need to look for an extent just
1768 * before the position we want in case there is outstanding delalloc
1771 if (origin
== SEEK_HOLE
&& start
!= 0) {
1772 if (start
<= root
->sectorsize
)
1773 em
= btrfs_get_extent_fiemap(inode
, NULL
, 0, 0,
1774 root
->sectorsize
, 0);
1776 em
= btrfs_get_extent_fiemap(inode
, NULL
, 0,
1777 start
- root
->sectorsize
,
1778 root
->sectorsize
, 0);
1783 last_end
= em
->start
+ em
->len
;
1784 if (em
->block_start
== EXTENT_MAP_DELALLOC
)
1785 last_end
= min_t(u64
, last_end
, inode
->i_size
);
1786 free_extent_map(em
);
1790 em
= btrfs_get_extent_fiemap(inode
, NULL
, 0, start
, len
, 0);
1796 if (em
->block_start
== EXTENT_MAP_HOLE
) {
1797 if (test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
)) {
1798 if (last_end
<= orig_start
) {
1799 free_extent_map(em
);
1805 if (origin
== SEEK_HOLE
) {
1807 free_extent_map(em
);
1811 if (origin
== SEEK_DATA
) {
1812 if (em
->block_start
== EXTENT_MAP_DELALLOC
) {
1813 if (start
>= inode
->i_size
) {
1814 free_extent_map(em
);
1821 free_extent_map(em
);
1826 start
= em
->start
+ em
->len
;
1827 last_end
= em
->start
+ em
->len
;
1829 if (em
->block_start
== EXTENT_MAP_DELALLOC
)
1830 last_end
= min_t(u64
, last_end
, inode
->i_size
);
1832 if (test_bit(EXTENT_FLAG_VACANCY
, &em
->flags
)) {
1833 free_extent_map(em
);
1837 free_extent_map(em
);
1841 *offset
= min(*offset
, inode
->i_size
);
1843 unlock_extent_cached(&BTRFS_I(inode
)->io_tree
, lockstart
, lockend
,
1844 &cached_state
, GFP_NOFS
);
1848 static loff_t
btrfs_file_llseek(struct file
*file
, loff_t offset
, int origin
)
1850 struct inode
*inode
= file
->f_mapping
->host
;
1853 mutex_lock(&inode
->i_mutex
);
1857 offset
= generic_file_llseek(file
, offset
, origin
);
1861 if (offset
>= i_size_read(inode
)) {
1862 mutex_unlock(&inode
->i_mutex
);
1866 ret
= find_desired_extent(inode
, &offset
, origin
);
1868 mutex_unlock(&inode
->i_mutex
);
1873 if (offset
< 0 && !(file
->f_mode
& FMODE_UNSIGNED_OFFSET
)) {
1877 if (offset
> inode
->i_sb
->s_maxbytes
) {
1882 /* Special lock needed here? */
1883 if (offset
!= file
->f_pos
) {
1884 file
->f_pos
= offset
;
1885 file
->f_version
= 0;
1888 mutex_unlock(&inode
->i_mutex
);
1892 const struct file_operations btrfs_file_operations
= {
1893 .llseek
= btrfs_file_llseek
,
1894 .read
= do_sync_read
,
1895 .write
= do_sync_write
,
1896 .aio_read
= generic_file_aio_read
,
1897 .splice_read
= generic_file_splice_read
,
1898 .aio_write
= btrfs_file_aio_write
,
1899 .mmap
= btrfs_file_mmap
,
1900 .open
= generic_file_open
,
1901 .release
= btrfs_release_file
,
1902 .fsync
= btrfs_sync_file
,
1903 .fallocate
= btrfs_fallocate
,
1904 .unlocked_ioctl
= btrfs_ioctl
,
1905 #ifdef CONFIG_COMPAT
1906 .compat_ioctl
= btrfs_ioctl
,