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,