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/aio.h>
28 #include <linux/falloc.h>
29 #include <linux/swap.h>
30 #include <linux/writeback.h>
31 #include <linux/statfs.h>
32 #include <linux/compat.h>
33 #include <linux/slab.h>
34 #include <linux/btrfs.h>
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "print-tree.h"
45 static struct kmem_cache *btrfs_inode_defrag_cachep;
47 * when auto defrag is enabled we
48 * queue up these defrag structs to remember which
49 * inodes need defragging passes
52 struct rb_node rb_node;
56 * transid where the defrag was added, we search for
57 * extents newer than this
64 /* last offset we were able to defrag */
67 /* if we've wrapped around back to zero once already */
71 static int __compare_inode_defrag(struct inode_defrag *defrag1,
72 struct inode_defrag *defrag2)
74 if (defrag1->root > defrag2->root)
76 else if (defrag1->root < defrag2->root)
78 else if (defrag1->ino > defrag2->ino)
80 else if (defrag1->ino < defrag2->ino)
86 /* pop a record for an inode into the defrag tree. The lock
87 * must be held already
89 * If you're inserting a record for an older transid than an
90 * existing record, the transid already in the tree is lowered
92 * If an existing record is found the defrag item you
95 static int __btrfs_add_inode_defrag(struct inode *inode,
96 struct inode_defrag *defrag)
98 struct btrfs_root *root = BTRFS_I(inode)->root;
99 struct inode_defrag *entry;
101 struct rb_node *parent = NULL;
104 p = &root->fs_info->defrag_inodes.rb_node;
107 entry = rb_entry(parent, struct inode_defrag, rb_node);
109 ret = __compare_inode_defrag(defrag, entry);
111 p = &parent->rb_left;
113 p = &parent->rb_right;
115 /* if we're reinserting an entry for
116 * an old defrag run, make sure to
117 * lower the transid of our existing record
119 if (defrag->transid < entry->transid)
120 entry->transid = defrag->transid;
121 if (defrag->last_offset > entry->last_offset)
122 entry->last_offset = defrag->last_offset;
126 set_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
127 rb_link_node(&defrag->rb_node, parent, p);
128 rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes);
132 static inline int __need_auto_defrag(struct btrfs_root *root)
134 if (!btrfs_test_opt(root, AUTO_DEFRAG))
137 if (btrfs_fs_closing(root->fs_info))
144 * insert a defrag record for this inode if auto defrag is
147 int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
150 struct btrfs_root *root = BTRFS_I(inode)->root;
151 struct inode_defrag *defrag;
155 if (!__need_auto_defrag(root))
158 if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags))
162 transid = trans->transid;
164 transid = BTRFS_I(inode)->root->last_trans;
166 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
170 defrag->ino = btrfs_ino(inode);
171 defrag->transid = transid;
172 defrag->root = root->root_key.objectid;
174 spin_lock(&root->fs_info->defrag_inodes_lock);
175 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) {
177 * If we set IN_DEFRAG flag and evict the inode from memory,
178 * and then re-read this inode, this new inode doesn't have
179 * IN_DEFRAG flag. At the case, we may find the existed defrag.
181 ret = __btrfs_add_inode_defrag(inode, defrag);
183 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
185 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
187 spin_unlock(&root->fs_info->defrag_inodes_lock);
192 * Requeue the defrag object. If there is a defrag object that points to
193 * the same inode in the tree, we will merge them together (by
194 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
196 static void btrfs_requeue_inode_defrag(struct inode *inode,
197 struct inode_defrag *defrag)
199 struct btrfs_root *root = BTRFS_I(inode)->root;
202 if (!__need_auto_defrag(root))
206 * Here we don't check the IN_DEFRAG flag, because we need merge
209 spin_lock(&root->fs_info->defrag_inodes_lock);
210 ret = __btrfs_add_inode_defrag(inode, defrag);
211 spin_unlock(&root->fs_info->defrag_inodes_lock);
216 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
220 * pick the defragable inode that we want, if it doesn't exist, we will get
223 static struct inode_defrag *
224 btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
226 struct inode_defrag *entry = NULL;
227 struct inode_defrag tmp;
229 struct rb_node *parent = NULL;
235 spin_lock(&fs_info->defrag_inodes_lock);
236 p = fs_info->defrag_inodes.rb_node;
239 entry = rb_entry(parent, struct inode_defrag, rb_node);
241 ret = __compare_inode_defrag(&tmp, entry);
245 p = parent->rb_right;
250 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
251 parent = rb_next(parent);
253 entry = rb_entry(parent, struct inode_defrag, rb_node);
259 rb_erase(parent, &fs_info->defrag_inodes);
260 spin_unlock(&fs_info->defrag_inodes_lock);
264 void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
266 struct inode_defrag *defrag;
267 struct rb_node *node;
269 spin_lock(&fs_info->defrag_inodes_lock);
270 node = rb_first(&fs_info->defrag_inodes);
272 rb_erase(node, &fs_info->defrag_inodes);
273 defrag = rb_entry(node, struct inode_defrag, rb_node);
274 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
276 if (need_resched()) {
277 spin_unlock(&fs_info->defrag_inodes_lock);
279 spin_lock(&fs_info->defrag_inodes_lock);
282 node = rb_first(&fs_info->defrag_inodes);
284 spin_unlock(&fs_info->defrag_inodes_lock);
287 #define BTRFS_DEFRAG_BATCH 1024
289 static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
290 struct inode_defrag *defrag)
292 struct btrfs_root *inode_root;
294 struct btrfs_key key;
295 struct btrfs_ioctl_defrag_range_args range;
301 key.objectid = defrag->root;
302 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
303 key.offset = (u64)-1;
305 index = srcu_read_lock(&fs_info->subvol_srcu);
307 inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
308 if (IS_ERR(inode_root)) {
309 ret = PTR_ERR(inode_root);
313 key.objectid = defrag->ino;
314 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
316 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
318 ret = PTR_ERR(inode);
321 srcu_read_unlock(&fs_info->subvol_srcu, index);
323 /* do a chunk of defrag */
324 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
325 memset(&range, 0, sizeof(range));
327 range.start = defrag->last_offset;
329 sb_start_write(fs_info->sb);
330 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
332 sb_end_write(fs_info->sb);
334 * if we filled the whole defrag batch, there
335 * must be more work to do. Queue this defrag
338 if (num_defrag == BTRFS_DEFRAG_BATCH) {
339 defrag->last_offset = range.start;
340 btrfs_requeue_inode_defrag(inode, defrag);
341 } else if (defrag->last_offset && !defrag->cycled) {
343 * we didn't fill our defrag batch, but
344 * we didn't start at zero. Make sure we loop
345 * around to the start of the file.
347 defrag->last_offset = 0;
349 btrfs_requeue_inode_defrag(inode, defrag);
351 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
357 srcu_read_unlock(&fs_info->subvol_srcu, index);
358 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
363 * run through the list of inodes in the FS that need
366 int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
368 struct inode_defrag *defrag;
370 u64 root_objectid = 0;
372 atomic_inc(&fs_info->defrag_running);
374 /* Pause the auto defragger. */
375 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
379 if (!__need_auto_defrag(fs_info->tree_root))
382 /* find an inode to defrag */
383 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
386 if (root_objectid || first_ino) {
395 first_ino = defrag->ino + 1;
396 root_objectid = defrag->root;
398 __btrfs_run_defrag_inode(fs_info, defrag);
400 atomic_dec(&fs_info->defrag_running);
403 * during unmount, we use the transaction_wait queue to
404 * wait for the defragger to stop
406 wake_up(&fs_info->transaction_wait);
410 /* simple helper to fault in pages and copy. This should go away
411 * and be replaced with calls into generic code.
413 static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
415 struct page **prepared_pages,
419 size_t total_copied = 0;
421 int offset = pos & (PAGE_CACHE_SIZE - 1);
423 while (write_bytes > 0) {
424 size_t count = min_t(size_t,
425 PAGE_CACHE_SIZE - offset, write_bytes);
426 struct page *page = prepared_pages[pg];
428 * Copy data from userspace to the current page
430 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
432 /* Flush processor's dcache for this page */
433 flush_dcache_page(page);
436 * if we get a partial write, we can end up with
437 * partially up to date pages. These add
438 * a lot of complexity, so make sure they don't
439 * happen by forcing this copy to be retried.
441 * The rest of the btrfs_file_write code will fall
442 * back to page at a time copies after we return 0.
444 if (!PageUptodate(page) && copied < count)
447 iov_iter_advance(i, copied);
448 write_bytes -= copied;
449 total_copied += copied;
451 /* Return to btrfs_file_write_iter to fault page */
452 if (unlikely(copied == 0))
455 if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
466 * unlocks pages after btrfs_file_write is done with them
468 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
471 for (i = 0; i < num_pages; i++) {
472 /* page checked is some magic around finding pages that
473 * have been modified without going through btrfs_set_page_dirty
474 * clear it here. There should be no need to mark the pages
475 * accessed as prepare_pages should have marked them accessed
476 * in prepare_pages via find_or_create_page()
478 ClearPageChecked(pages[i]);
479 unlock_page(pages[i]);
480 page_cache_release(pages[i]);
485 * after copy_from_user, pages need to be dirtied and we need to make
486 * sure holes are created between the current EOF and the start of
487 * any next extents (if required).
489 * this also makes the decision about creating an inline extent vs
490 * doing real data extents, marking pages dirty and delalloc as required.
492 int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode,
493 struct page **pages, size_t num_pages,
494 loff_t pos, size_t write_bytes,
495 struct extent_state **cached)
501 u64 end_of_last_block;
502 u64 end_pos = pos + write_bytes;
503 loff_t isize = i_size_read(inode);
505 start_pos = pos & ~((u64)root->sectorsize - 1);
506 num_bytes = ALIGN(write_bytes + pos - start_pos, root->sectorsize);
508 end_of_last_block = start_pos + num_bytes - 1;
509 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
514 for (i = 0; i < num_pages; i++) {
515 struct page *p = pages[i];
522 * we've only changed i_size in ram, and we haven't updated
523 * the disk i_size. There is no need to log the inode
527 i_size_write(inode, end_pos);
532 * this drops all the extents in the cache that intersect the range
533 * [start, end]. Existing extents are split as required.
535 void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
538 struct extent_map *em;
539 struct extent_map *split = NULL;
540 struct extent_map *split2 = NULL;
541 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
542 u64 len = end - start + 1;
550 WARN_ON(end < start);
551 if (end == (u64)-1) {
560 split = alloc_extent_map();
562 split2 = alloc_extent_map();
563 if (!split || !split2)
566 write_lock(&em_tree->lock);
567 em = lookup_extent_mapping(em_tree, start, len);
569 write_unlock(&em_tree->lock);
573 gen = em->generation;
574 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
575 if (testend && em->start + em->len >= start + len) {
577 write_unlock(&em_tree->lock);
580 start = em->start + em->len;
582 len = start + len - (em->start + em->len);
584 write_unlock(&em_tree->lock);
587 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
588 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
589 clear_bit(EXTENT_FLAG_LOGGING, &flags);
590 modified = !list_empty(&em->list);
594 if (em->start < start) {
595 split->start = em->start;
596 split->len = start - em->start;
598 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
599 split->orig_start = em->orig_start;
600 split->block_start = em->block_start;
603 split->block_len = em->block_len;
605 split->block_len = split->len;
606 split->orig_block_len = max(split->block_len,
608 split->ram_bytes = em->ram_bytes;
610 split->orig_start = split->start;
611 split->block_len = 0;
612 split->block_start = em->block_start;
613 split->orig_block_len = 0;
614 split->ram_bytes = split->len;
617 split->generation = gen;
618 split->bdev = em->bdev;
619 split->flags = flags;
620 split->compress_type = em->compress_type;
621 replace_extent_mapping(em_tree, em, split, modified);
622 free_extent_map(split);
626 if (testend && em->start + em->len > start + len) {
627 u64 diff = start + len - em->start;
629 split->start = start + len;
630 split->len = em->start + em->len - (start + len);
631 split->bdev = em->bdev;
632 split->flags = flags;
633 split->compress_type = em->compress_type;
634 split->generation = gen;
636 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
637 split->orig_block_len = max(em->block_len,
640 split->ram_bytes = em->ram_bytes;
642 split->block_len = em->block_len;
643 split->block_start = em->block_start;
644 split->orig_start = em->orig_start;
646 split->block_len = split->len;
647 split->block_start = em->block_start
649 split->orig_start = em->orig_start;
652 split->ram_bytes = split->len;
653 split->orig_start = split->start;
654 split->block_len = 0;
655 split->block_start = em->block_start;
656 split->orig_block_len = 0;
659 if (extent_map_in_tree(em)) {
660 replace_extent_mapping(em_tree, em, split,
663 ret = add_extent_mapping(em_tree, split,
665 ASSERT(ret == 0); /* Logic error */
667 free_extent_map(split);
671 if (extent_map_in_tree(em))
672 remove_extent_mapping(em_tree, em);
673 write_unlock(&em_tree->lock);
677 /* once for the tree*/
681 free_extent_map(split);
683 free_extent_map(split2);
687 * this is very complex, but the basic idea is to drop all extents
688 * in the range start - end. hint_block is filled in with a block number
689 * that would be a good hint to the block allocator for this file.
691 * If an extent intersects the range but is not entirely inside the range
692 * it is either truncated or split. Anything entirely inside the range
693 * is deleted from the tree.
695 int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
696 struct btrfs_root *root, struct inode *inode,
697 struct btrfs_path *path, u64 start, u64 end,
698 u64 *drop_end, int drop_cache,
700 u32 extent_item_size,
703 struct extent_buffer *leaf;
704 struct btrfs_file_extent_item *fi;
705 struct btrfs_key key;
706 struct btrfs_key new_key;
707 u64 ino = btrfs_ino(inode);
708 u64 search_start = start;
711 u64 extent_offset = 0;
718 int modify_tree = -1;
721 int leafs_visited = 0;
724 btrfs_drop_extent_cache(inode, start, end - 1, 0);
726 if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent)
729 update_refs = (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
730 root == root->fs_info->tree_root);
733 ret = btrfs_lookup_file_extent(trans, root, path, ino,
734 search_start, modify_tree);
737 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
738 leaf = path->nodes[0];
739 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
740 if (key.objectid == ino &&
741 key.type == BTRFS_EXTENT_DATA_KEY)
747 leaf = path->nodes[0];
748 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
750 ret = btrfs_next_leaf(root, path);
758 leaf = path->nodes[0];
762 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
763 if (key.objectid > ino ||
764 key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
767 fi = btrfs_item_ptr(leaf, path->slots[0],
768 struct btrfs_file_extent_item);
769 extent_type = btrfs_file_extent_type(leaf, fi);
771 if (extent_type == BTRFS_FILE_EXTENT_REG ||
772 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
773 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
774 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
775 extent_offset = btrfs_file_extent_offset(leaf, fi);
776 extent_end = key.offset +
777 btrfs_file_extent_num_bytes(leaf, fi);
778 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
779 extent_end = key.offset +
780 btrfs_file_extent_inline_len(leaf,
784 extent_end = search_start;
788 * Don't skip extent items representing 0 byte lengths. They
789 * used to be created (bug) if while punching holes we hit
790 * -ENOSPC condition. So if we find one here, just ensure we
791 * delete it, otherwise we would insert a new file extent item
792 * with the same key (offset) as that 0 bytes length file
793 * extent item in the call to setup_items_for_insert() later
796 if (extent_end == key.offset && extent_end >= search_start)
797 goto delete_extent_item;
799 if (extent_end <= search_start) {
805 search_start = max(key.offset, start);
806 if (recow || !modify_tree) {
808 btrfs_release_path(path);
813 * | - range to drop - |
814 * | -------- extent -------- |
816 if (start > key.offset && end < extent_end) {
818 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
823 memcpy(&new_key, &key, sizeof(new_key));
824 new_key.offset = start;
825 ret = btrfs_duplicate_item(trans, root, path,
827 if (ret == -EAGAIN) {
828 btrfs_release_path(path);
834 leaf = path->nodes[0];
835 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
836 struct btrfs_file_extent_item);
837 btrfs_set_file_extent_num_bytes(leaf, fi,
840 fi = btrfs_item_ptr(leaf, path->slots[0],
841 struct btrfs_file_extent_item);
843 extent_offset += start - key.offset;
844 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
845 btrfs_set_file_extent_num_bytes(leaf, fi,
847 btrfs_mark_buffer_dirty(leaf);
849 if (update_refs && disk_bytenr > 0) {
850 ret = btrfs_inc_extent_ref(trans, root,
851 disk_bytenr, num_bytes, 0,
852 root->root_key.objectid,
854 start - extent_offset, 1);
855 BUG_ON(ret); /* -ENOMEM */
860 * | ---- range to drop ----- |
861 * | -------- extent -------- |
863 if (start <= key.offset && end < extent_end) {
864 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
869 memcpy(&new_key, &key, sizeof(new_key));
870 new_key.offset = end;
871 btrfs_set_item_key_safe(root, path, &new_key);
873 extent_offset += end - key.offset;
874 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
875 btrfs_set_file_extent_num_bytes(leaf, fi,
877 btrfs_mark_buffer_dirty(leaf);
878 if (update_refs && disk_bytenr > 0)
879 inode_sub_bytes(inode, end - key.offset);
883 search_start = extent_end;
885 * | ---- range to drop ----- |
886 * | -------- extent -------- |
888 if (start > key.offset && end >= extent_end) {
890 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
895 btrfs_set_file_extent_num_bytes(leaf, fi,
897 btrfs_mark_buffer_dirty(leaf);
898 if (update_refs && disk_bytenr > 0)
899 inode_sub_bytes(inode, extent_end - start);
900 if (end == extent_end)
908 * | ---- range to drop ----- |
909 * | ------ extent ------ |
911 if (start <= key.offset && end >= extent_end) {
914 del_slot = path->slots[0];
917 BUG_ON(del_slot + del_nr != path->slots[0]);
922 extent_type == BTRFS_FILE_EXTENT_INLINE) {
923 inode_sub_bytes(inode,
924 extent_end - key.offset);
925 extent_end = ALIGN(extent_end,
927 } else if (update_refs && disk_bytenr > 0) {
928 ret = btrfs_free_extent(trans, root,
929 disk_bytenr, num_bytes, 0,
930 root->root_key.objectid,
931 key.objectid, key.offset -
933 BUG_ON(ret); /* -ENOMEM */
934 inode_sub_bytes(inode,
935 extent_end - key.offset);
938 if (end == extent_end)
941 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
946 ret = btrfs_del_items(trans, root, path, del_slot,
949 btrfs_abort_transaction(trans, root, ret);
956 btrfs_release_path(path);
963 if (!ret && del_nr > 0) {
965 * Set path->slots[0] to first slot, so that after the delete
966 * if items are move off from our leaf to its immediate left or
967 * right neighbor leafs, we end up with a correct and adjusted
968 * path->slots[0] for our insertion (if replace_extent != 0).
970 path->slots[0] = del_slot;
971 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
973 btrfs_abort_transaction(trans, root, ret);
976 leaf = path->nodes[0];
978 * If btrfs_del_items() was called, it might have deleted a leaf, in
979 * which case it unlocked our path, so check path->locks[0] matches a
982 if (!ret && replace_extent && leafs_visited == 1 &&
983 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
984 path->locks[0] == BTRFS_WRITE_LOCK) &&
985 btrfs_leaf_free_space(root, leaf) >=
986 sizeof(struct btrfs_item) + extent_item_size) {
989 key.type = BTRFS_EXTENT_DATA_KEY;
991 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
992 struct btrfs_key slot_key;
994 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
995 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
998 setup_items_for_insert(root, path, &key,
1001 sizeof(struct btrfs_item) +
1002 extent_item_size, 1);
1006 if (!replace_extent || !(*key_inserted))
1007 btrfs_release_path(path);
1009 *drop_end = found ? min(end, extent_end) : end;
1013 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
1014 struct btrfs_root *root, struct inode *inode, u64 start,
1015 u64 end, int drop_cache)
1017 struct btrfs_path *path;
1020 path = btrfs_alloc_path();
1023 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
1024 drop_cache, 0, 0, NULL);
1025 btrfs_free_path(path);
1029 static int extent_mergeable(struct extent_buffer *leaf, int slot,
1030 u64 objectid, u64 bytenr, u64 orig_offset,
1031 u64 *start, u64 *end)
1033 struct btrfs_file_extent_item *fi;
1034 struct btrfs_key key;
1037 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1040 btrfs_item_key_to_cpu(leaf, &key, slot);
1041 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1044 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1045 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1046 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1047 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1048 btrfs_file_extent_compression(leaf, fi) ||
1049 btrfs_file_extent_encryption(leaf, fi) ||
1050 btrfs_file_extent_other_encoding(leaf, fi))
1053 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1054 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1057 *start = key.offset;
1063 * Mark extent in the range start - end as written.
1065 * This changes extent type from 'pre-allocated' to 'regular'. If only
1066 * part of extent is marked as written, the extent will be split into
1069 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1070 struct inode *inode, u64 start, u64 end)
1072 struct btrfs_root *root = BTRFS_I(inode)->root;
1073 struct extent_buffer *leaf;
1074 struct btrfs_path *path;
1075 struct btrfs_file_extent_item *fi;
1076 struct btrfs_key key;
1077 struct btrfs_key new_key;
1089 u64 ino = btrfs_ino(inode);
1091 path = btrfs_alloc_path();
1098 key.type = BTRFS_EXTENT_DATA_KEY;
1101 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1104 if (ret > 0 && path->slots[0] > 0)
1107 leaf = path->nodes[0];
1108 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1109 BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY);
1110 fi = btrfs_item_ptr(leaf, path->slots[0],
1111 struct btrfs_file_extent_item);
1112 BUG_ON(btrfs_file_extent_type(leaf, fi) !=
1113 BTRFS_FILE_EXTENT_PREALLOC);
1114 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1115 BUG_ON(key.offset > start || extent_end < end);
1117 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1118 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1119 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1120 memcpy(&new_key, &key, sizeof(new_key));
1122 if (start == key.offset && end < extent_end) {
1125 if (extent_mergeable(leaf, path->slots[0] - 1,
1126 ino, bytenr, orig_offset,
1127 &other_start, &other_end)) {
1128 new_key.offset = end;
1129 btrfs_set_item_key_safe(root, path, &new_key);
1130 fi = btrfs_item_ptr(leaf, path->slots[0],
1131 struct btrfs_file_extent_item);
1132 btrfs_set_file_extent_generation(leaf, fi,
1134 btrfs_set_file_extent_num_bytes(leaf, fi,
1136 btrfs_set_file_extent_offset(leaf, fi,
1138 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1139 struct btrfs_file_extent_item);
1140 btrfs_set_file_extent_generation(leaf, fi,
1142 btrfs_set_file_extent_num_bytes(leaf, fi,
1144 btrfs_mark_buffer_dirty(leaf);
1149 if (start > key.offset && end == extent_end) {
1152 if (extent_mergeable(leaf, path->slots[0] + 1,
1153 ino, bytenr, orig_offset,
1154 &other_start, &other_end)) {
1155 fi = btrfs_item_ptr(leaf, path->slots[0],
1156 struct btrfs_file_extent_item);
1157 btrfs_set_file_extent_num_bytes(leaf, fi,
1158 start - key.offset);
1159 btrfs_set_file_extent_generation(leaf, fi,
1162 new_key.offset = start;
1163 btrfs_set_item_key_safe(root, path, &new_key);
1165 fi = btrfs_item_ptr(leaf, path->slots[0],
1166 struct btrfs_file_extent_item);
1167 btrfs_set_file_extent_generation(leaf, fi,
1169 btrfs_set_file_extent_num_bytes(leaf, fi,
1171 btrfs_set_file_extent_offset(leaf, fi,
1172 start - orig_offset);
1173 btrfs_mark_buffer_dirty(leaf);
1178 while (start > key.offset || end < extent_end) {
1179 if (key.offset == start)
1182 new_key.offset = split;
1183 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1184 if (ret == -EAGAIN) {
1185 btrfs_release_path(path);
1189 btrfs_abort_transaction(trans, root, ret);
1193 leaf = path->nodes[0];
1194 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1195 struct btrfs_file_extent_item);
1196 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1197 btrfs_set_file_extent_num_bytes(leaf, fi,
1198 split - key.offset);
1200 fi = btrfs_item_ptr(leaf, path->slots[0],
1201 struct btrfs_file_extent_item);
1203 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1204 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1205 btrfs_set_file_extent_num_bytes(leaf, fi,
1206 extent_end - split);
1207 btrfs_mark_buffer_dirty(leaf);
1209 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
1210 root->root_key.objectid,
1211 ino, orig_offset, 1);
1212 BUG_ON(ret); /* -ENOMEM */
1214 if (split == start) {
1217 BUG_ON(start != key.offset);
1226 if (extent_mergeable(leaf, path->slots[0] + 1,
1227 ino, bytenr, orig_offset,
1228 &other_start, &other_end)) {
1230 btrfs_release_path(path);
1233 extent_end = other_end;
1234 del_slot = path->slots[0] + 1;
1236 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1237 0, root->root_key.objectid,
1238 ino, orig_offset, 0);
1239 BUG_ON(ret); /* -ENOMEM */
1243 if (extent_mergeable(leaf, path->slots[0] - 1,
1244 ino, bytenr, orig_offset,
1245 &other_start, &other_end)) {
1247 btrfs_release_path(path);
1250 key.offset = other_start;
1251 del_slot = path->slots[0];
1253 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1254 0, root->root_key.objectid,
1255 ino, orig_offset, 0);
1256 BUG_ON(ret); /* -ENOMEM */
1259 fi = btrfs_item_ptr(leaf, path->slots[0],
1260 struct btrfs_file_extent_item);
1261 btrfs_set_file_extent_type(leaf, fi,
1262 BTRFS_FILE_EXTENT_REG);
1263 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1264 btrfs_mark_buffer_dirty(leaf);
1266 fi = btrfs_item_ptr(leaf, del_slot - 1,
1267 struct btrfs_file_extent_item);
1268 btrfs_set_file_extent_type(leaf, fi,
1269 BTRFS_FILE_EXTENT_REG);
1270 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1271 btrfs_set_file_extent_num_bytes(leaf, fi,
1272 extent_end - key.offset);
1273 btrfs_mark_buffer_dirty(leaf);
1275 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1277 btrfs_abort_transaction(trans, root, ret);
1282 btrfs_free_path(path);
1287 * on error we return an unlocked page and the error value
1288 * on success we return a locked page and 0
1290 static int prepare_uptodate_page(struct page *page, u64 pos,
1291 bool force_uptodate)
1295 if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
1296 !PageUptodate(page)) {
1297 ret = btrfs_readpage(NULL, page);
1301 if (!PageUptodate(page)) {
1310 * this just gets pages into the page cache and locks them down.
1312 static noinline int prepare_pages(struct inode *inode, struct page **pages,
1313 size_t num_pages, loff_t pos,
1314 size_t write_bytes, bool force_uptodate)
1317 unsigned long index = pos >> PAGE_CACHE_SHIFT;
1318 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1322 for (i = 0; i < num_pages; i++) {
1323 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1324 mask | __GFP_WRITE);
1332 err = prepare_uptodate_page(pages[i], pos,
1334 if (i == num_pages - 1)
1335 err = prepare_uptodate_page(pages[i],
1336 pos + write_bytes, false);
1338 page_cache_release(pages[i]);
1342 wait_on_page_writeback(pages[i]);
1347 while (faili >= 0) {
1348 unlock_page(pages[faili]);
1349 page_cache_release(pages[faili]);
1357 * This function locks the extent and properly waits for data=ordered extents
1358 * to finish before allowing the pages to be modified if need.
1361 * 1 - the extent is locked
1362 * 0 - the extent is not locked, and everything is OK
1363 * -EAGAIN - need re-prepare the pages
1364 * the other < 0 number - Something wrong happens
1367 lock_and_cleanup_extent_if_need(struct inode *inode, struct page **pages,
1368 size_t num_pages, loff_t pos,
1369 u64 *lockstart, u64 *lockend,
1370 struct extent_state **cached_state)
1377 start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
1378 last_pos = start_pos + ((u64)num_pages << PAGE_CACHE_SHIFT) - 1;
1380 if (start_pos < inode->i_size) {
1381 struct btrfs_ordered_extent *ordered;
1382 lock_extent_bits(&BTRFS_I(inode)->io_tree,
1383 start_pos, last_pos, 0, cached_state);
1384 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1385 last_pos - start_pos + 1);
1387 ordered->file_offset + ordered->len > start_pos &&
1388 ordered->file_offset <= last_pos) {
1389 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1390 start_pos, last_pos,
1391 cached_state, GFP_NOFS);
1392 for (i = 0; i < num_pages; i++) {
1393 unlock_page(pages[i]);
1394 page_cache_release(pages[i]);
1396 btrfs_start_ordered_extent(inode, ordered, 1);
1397 btrfs_put_ordered_extent(ordered);
1401 btrfs_put_ordered_extent(ordered);
1403 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
1404 last_pos, EXTENT_DIRTY | EXTENT_DELALLOC |
1405 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
1406 0, 0, cached_state, GFP_NOFS);
1407 *lockstart = start_pos;
1408 *lockend = last_pos;
1412 for (i = 0; i < num_pages; i++) {
1413 if (clear_page_dirty_for_io(pages[i]))
1414 account_page_redirty(pages[i]);
1415 set_page_extent_mapped(pages[i]);
1416 WARN_ON(!PageLocked(pages[i]));
1422 static noinline int check_can_nocow(struct inode *inode, loff_t pos,
1423 size_t *write_bytes)
1425 struct btrfs_root *root = BTRFS_I(inode)->root;
1426 struct btrfs_ordered_extent *ordered;
1427 u64 lockstart, lockend;
1431 ret = btrfs_start_nocow_write(root);
1435 lockstart = round_down(pos, root->sectorsize);
1436 lockend = round_up(pos + *write_bytes, root->sectorsize) - 1;
1439 lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1440 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1441 lockend - lockstart + 1);
1445 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1446 btrfs_start_ordered_extent(inode, ordered, 1);
1447 btrfs_put_ordered_extent(ordered);
1450 num_bytes = lockend - lockstart + 1;
1451 ret = can_nocow_extent(inode, lockstart, &num_bytes, NULL, NULL, NULL);
1454 btrfs_end_nocow_write(root);
1456 *write_bytes = min_t(size_t, *write_bytes ,
1457 num_bytes - pos + lockstart);
1460 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1465 static noinline ssize_t __btrfs_buffered_write(struct file *file,
1469 struct inode *inode = file_inode(file);
1470 struct btrfs_root *root = BTRFS_I(inode)->root;
1471 struct page **pages = NULL;
1472 struct extent_state *cached_state = NULL;
1473 u64 release_bytes = 0;
1476 unsigned long first_index;
1477 size_t num_written = 0;
1480 bool only_release_metadata = false;
1481 bool force_page_uptodate = false;
1484 nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
1485 PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
1486 (sizeof(struct page *)));
1487 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1488 nrptrs = max(nrptrs, 8);
1489 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
1493 first_index = pos >> PAGE_CACHE_SHIFT;
1495 while (iov_iter_count(i) > 0) {
1496 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
1497 size_t write_bytes = min(iov_iter_count(i),
1498 nrptrs * (size_t)PAGE_CACHE_SIZE -
1500 size_t num_pages = (write_bytes + offset +
1501 PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1502 size_t reserve_bytes;
1506 WARN_ON(num_pages > nrptrs);
1509 * Fault pages before locking them in prepare_pages
1510 * to avoid recursive lock
1512 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1517 reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
1518 ret = btrfs_check_data_free_space(inode, reserve_bytes);
1519 if (ret == -ENOSPC &&
1520 (BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1521 BTRFS_INODE_PREALLOC))) {
1522 ret = check_can_nocow(inode, pos, &write_bytes);
1524 only_release_metadata = true;
1526 * our prealloc extent may be smaller than
1527 * write_bytes, so scale down.
1529 num_pages = (write_bytes + offset +
1530 PAGE_CACHE_SIZE - 1) >>
1532 reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
1542 ret = btrfs_delalloc_reserve_metadata(inode, reserve_bytes);
1544 if (!only_release_metadata)
1545 btrfs_free_reserved_data_space(inode,
1548 btrfs_end_nocow_write(root);
1552 release_bytes = reserve_bytes;
1553 need_unlock = false;
1556 * This is going to setup the pages array with the number of
1557 * pages we want, so we don't really need to worry about the
1558 * contents of pages from loop to loop
1560 ret = prepare_pages(inode, pages, num_pages,
1562 force_page_uptodate);
1566 ret = lock_and_cleanup_extent_if_need(inode, pages, num_pages,
1567 pos, &lockstart, &lockend,
1573 } else if (ret > 0) {
1578 copied = btrfs_copy_from_user(pos, num_pages,
1579 write_bytes, pages, i);
1582 * if we have trouble faulting in the pages, fall
1583 * back to one page at a time
1585 if (copied < write_bytes)
1589 force_page_uptodate = true;
1592 force_page_uptodate = false;
1593 dirty_pages = (copied + offset +
1594 PAGE_CACHE_SIZE - 1) >>
1599 * If we had a short copy we need to release the excess delaloc
1600 * bytes we reserved. We need to increment outstanding_extents
1601 * because btrfs_delalloc_release_space will decrement it, but
1602 * we still have an outstanding extent for the chunk we actually
1605 if (num_pages > dirty_pages) {
1606 release_bytes = (num_pages - dirty_pages) <<
1609 spin_lock(&BTRFS_I(inode)->lock);
1610 BTRFS_I(inode)->outstanding_extents++;
1611 spin_unlock(&BTRFS_I(inode)->lock);
1613 if (only_release_metadata)
1614 btrfs_delalloc_release_metadata(inode,
1617 btrfs_delalloc_release_space(inode,
1621 release_bytes = dirty_pages << PAGE_CACHE_SHIFT;
1624 ret = btrfs_dirty_pages(root, inode, pages,
1625 dirty_pages, pos, copied,
1628 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1629 lockstart, lockend, &cached_state,
1632 btrfs_drop_pages(pages, num_pages);
1637 if (only_release_metadata)
1638 btrfs_end_nocow_write(root);
1640 if (only_release_metadata && copied > 0) {
1641 u64 lockstart = round_down(pos, root->sectorsize);
1642 u64 lockend = lockstart +
1643 (dirty_pages << PAGE_CACHE_SHIFT) - 1;
1645 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1646 lockend, EXTENT_NORESERVE, NULL,
1648 only_release_metadata = false;
1651 btrfs_drop_pages(pages, num_pages);
1655 balance_dirty_pages_ratelimited(inode->i_mapping);
1656 if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
1657 btrfs_btree_balance_dirty(root);
1660 num_written += copied;
1665 if (release_bytes) {
1666 if (only_release_metadata) {
1667 btrfs_end_nocow_write(root);
1668 btrfs_delalloc_release_metadata(inode, release_bytes);
1670 btrfs_delalloc_release_space(inode, release_bytes);
1674 return num_written ? num_written : ret;
1677 static ssize_t __btrfs_direct_write(struct kiocb *iocb,
1678 struct iov_iter *from,
1681 struct file *file = iocb->ki_filp;
1683 ssize_t written_buffered;
1687 written = generic_file_direct_write(iocb, from, pos);
1689 if (written < 0 || !iov_iter_count(from))
1693 written_buffered = __btrfs_buffered_write(file, from, pos);
1694 if (written_buffered < 0) {
1695 err = written_buffered;
1698 endbyte = pos + written_buffered - 1;
1699 err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
1702 written += written_buffered;
1703 iocb->ki_pos = pos + written_buffered;
1704 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,
1705 endbyte >> PAGE_CACHE_SHIFT);
1707 return written ? written : err;
1710 static void update_time_for_write(struct inode *inode)
1712 struct timespec now;
1714 if (IS_NOCMTIME(inode))
1717 now = current_fs_time(inode->i_sb);
1718 if (!timespec_equal(&inode->i_mtime, &now))
1719 inode->i_mtime = now;
1721 if (!timespec_equal(&inode->i_ctime, &now))
1722 inode->i_ctime = now;
1724 if (IS_I_VERSION(inode))
1725 inode_inc_iversion(inode);
1728 static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1729 struct iov_iter *from)
1731 struct file *file = iocb->ki_filp;
1732 struct inode *inode = file_inode(file);
1733 struct btrfs_root *root = BTRFS_I(inode)->root;
1736 ssize_t num_written = 0;
1738 size_t count = iov_iter_count(from);
1739 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
1740 loff_t pos = iocb->ki_pos;
1742 mutex_lock(&inode->i_mutex);
1744 current->backing_dev_info = inode->i_mapping->backing_dev_info;
1745 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1747 mutex_unlock(&inode->i_mutex);
1752 mutex_unlock(&inode->i_mutex);
1756 iov_iter_truncate(from, count);
1758 err = file_remove_suid(file);
1760 mutex_unlock(&inode->i_mutex);
1765 * If BTRFS flips readonly due to some impossible error
1766 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1767 * although we have opened a file as writable, we have
1768 * to stop this write operation to ensure FS consistency.
1770 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1771 mutex_unlock(&inode->i_mutex);
1777 * We reserve space for updating the inode when we reserve space for the
1778 * extent we are going to write, so we will enospc out there. We don't
1779 * need to start yet another transaction to update the inode as we will
1780 * update the inode when we finish writing whatever data we write.
1782 update_time_for_write(inode);
1784 start_pos = round_down(pos, root->sectorsize);
1785 if (start_pos > i_size_read(inode)) {
1786 /* Expand hole size to cover write data, preventing empty gap */
1787 end_pos = round_up(pos + count, root->sectorsize);
1788 err = btrfs_cont_expand(inode, i_size_read(inode), end_pos);
1790 mutex_unlock(&inode->i_mutex);
1796 atomic_inc(&BTRFS_I(inode)->sync_writers);
1798 if (unlikely(file->f_flags & O_DIRECT)) {
1799 num_written = __btrfs_direct_write(iocb, from, pos);
1801 num_written = __btrfs_buffered_write(file, from, pos);
1802 if (num_written > 0)
1803 iocb->ki_pos = pos + num_written;
1806 mutex_unlock(&inode->i_mutex);
1809 * we want to make sure fsync finds this change
1810 * but we haven't joined a transaction running right now.
1812 * Later on, someone is sure to update the inode and get the
1813 * real transid recorded.
1815 * We set last_trans now to the fs_info generation + 1,
1816 * this will either be one more than the running transaction
1817 * or the generation used for the next transaction if there isn't
1818 * one running right now.
1820 * We also have to set last_sub_trans to the current log transid,
1821 * otherwise subsequent syncs to a file that's been synced in this
1822 * transaction will appear to have already occured.
1824 BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
1825 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1826 if (num_written > 0) {
1827 err = generic_write_sync(file, pos, num_written);
1833 atomic_dec(&BTRFS_I(inode)->sync_writers);
1835 current->backing_dev_info = NULL;
1836 return num_written ? num_written : err;
1839 int btrfs_release_file(struct inode *inode, struct file *filp)
1841 if (filp->private_data)
1842 btrfs_ioctl_trans_end(filp);
1844 * ordered_data_close is set by settattr when we are about to truncate
1845 * a file from a non-zero size to a zero size. This tries to
1846 * flush down new bytes that may have been written if the
1847 * application were using truncate to replace a file in place.
1849 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
1850 &BTRFS_I(inode)->runtime_flags))
1851 filemap_flush(inode->i_mapping);
1856 * fsync call for both files and directories. This logs the inode into
1857 * the tree log instead of forcing full commits whenever possible.
1859 * It needs to call filemap_fdatawait so that all ordered extent updates are
1860 * in the metadata btree are up to date for copying to the log.
1862 * It drops the inode mutex before doing the tree log commit. This is an
1863 * important optimization for directories because holding the mutex prevents
1864 * new operations on the dir while we write to disk.
1866 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
1868 struct dentry *dentry = file->f_path.dentry;
1869 struct inode *inode = dentry->d_inode;
1870 struct btrfs_root *root = BTRFS_I(inode)->root;
1871 struct btrfs_trans_handle *trans;
1872 struct btrfs_log_ctx ctx;
1876 trace_btrfs_sync_file(file, datasync);
1879 * We write the dirty pages in the range and wait until they complete
1880 * out of the ->i_mutex. If so, we can flush the dirty pages by
1881 * multi-task, and make the performance up. See
1882 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
1884 atomic_inc(&BTRFS_I(inode)->sync_writers);
1885 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
1886 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1887 &BTRFS_I(inode)->runtime_flags))
1888 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
1889 atomic_dec(&BTRFS_I(inode)->sync_writers);
1893 mutex_lock(&inode->i_mutex);
1896 * We flush the dirty pages again to avoid some dirty pages in the
1899 atomic_inc(&root->log_batch);
1900 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1901 &BTRFS_I(inode)->runtime_flags);
1903 ret = btrfs_wait_ordered_range(inode, start, end - start + 1);
1905 mutex_unlock(&inode->i_mutex);
1909 atomic_inc(&root->log_batch);
1912 * check the transaction that last modified this inode
1913 * and see if its already been committed
1915 if (!BTRFS_I(inode)->last_trans) {
1916 mutex_unlock(&inode->i_mutex);
1921 * if the last transaction that changed this file was before
1922 * the current transaction, we can bail out now without any
1926 if (btrfs_inode_in_log(inode, root->fs_info->generation) ||
1927 BTRFS_I(inode)->last_trans <=
1928 root->fs_info->last_trans_committed) {
1929 BTRFS_I(inode)->last_trans = 0;
1932 * We'v had everything committed since the last time we were
1933 * modified so clear this flag in case it was set for whatever
1934 * reason, it's no longer relevant.
1936 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1937 &BTRFS_I(inode)->runtime_flags);
1938 mutex_unlock(&inode->i_mutex);
1943 * ok we haven't committed the transaction yet, lets do a commit
1945 if (file->private_data)
1946 btrfs_ioctl_trans_end(file);
1949 * We use start here because we will need to wait on the IO to complete
1950 * in btrfs_sync_log, which could require joining a transaction (for
1951 * example checking cross references in the nocow path). If we use join
1952 * here we could get into a situation where we're waiting on IO to
1953 * happen that is blocked on a transaction trying to commit. With start
1954 * we inc the extwriter counter, so we wait for all extwriters to exit
1955 * before we start blocking join'ers. This comment is to keep somebody
1956 * from thinking they are super smart and changing this to
1957 * btrfs_join_transaction *cough*Josef*cough*.
1959 trans = btrfs_start_transaction(root, 0);
1960 if (IS_ERR(trans)) {
1961 ret = PTR_ERR(trans);
1962 mutex_unlock(&inode->i_mutex);
1967 btrfs_init_log_ctx(&ctx);
1969 ret = btrfs_log_dentry_safe(trans, root, dentry, &ctx);
1971 /* Fallthrough and commit/free transaction. */
1975 /* we've logged all the items and now have a consistent
1976 * version of the file in the log. It is possible that
1977 * someone will come in and modify the file, but that's
1978 * fine because the log is consistent on disk, and we
1979 * have references to all of the file's extents
1981 * It is possible that someone will come in and log the
1982 * file again, but that will end up using the synchronization
1983 * inside btrfs_sync_log to keep things safe.
1985 mutex_unlock(&inode->i_mutex);
1987 if (ret != BTRFS_NO_LOG_SYNC) {
1989 ret = btrfs_sync_log(trans, root, &ctx);
1991 ret = btrfs_end_transaction(trans, root);
1996 ret = btrfs_wait_ordered_range(inode, start,
1999 btrfs_end_transaction(trans, root);
2003 ret = btrfs_commit_transaction(trans, root);
2005 ret = btrfs_end_transaction(trans, root);
2008 return ret > 0 ? -EIO : ret;
2011 static const struct vm_operations_struct btrfs_file_vm_ops = {
2012 .fault = filemap_fault,
2013 .map_pages = filemap_map_pages,
2014 .page_mkwrite = btrfs_page_mkwrite,
2015 .remap_pages = generic_file_remap_pages,
2018 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2020 struct address_space *mapping = filp->f_mapping;
2022 if (!mapping->a_ops->readpage)
2025 file_accessed(filp);
2026 vma->vm_ops = &btrfs_file_vm_ops;
2031 static int hole_mergeable(struct inode *inode, struct extent_buffer *leaf,
2032 int slot, u64 start, u64 end)
2034 struct btrfs_file_extent_item *fi;
2035 struct btrfs_key key;
2037 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2040 btrfs_item_key_to_cpu(leaf, &key, slot);
2041 if (key.objectid != btrfs_ino(inode) ||
2042 key.type != BTRFS_EXTENT_DATA_KEY)
2045 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2047 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2050 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2053 if (key.offset == end)
2055 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2060 static int fill_holes(struct btrfs_trans_handle *trans, struct inode *inode,
2061 struct btrfs_path *path, u64 offset, u64 end)
2063 struct btrfs_root *root = BTRFS_I(inode)->root;
2064 struct extent_buffer *leaf;
2065 struct btrfs_file_extent_item *fi;
2066 struct extent_map *hole_em;
2067 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2068 struct btrfs_key key;
2071 if (btrfs_fs_incompat(root->fs_info, NO_HOLES))
2074 key.objectid = btrfs_ino(inode);
2075 key.type = BTRFS_EXTENT_DATA_KEY;
2076 key.offset = offset;
2078 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2083 leaf = path->nodes[0];
2084 if (hole_mergeable(inode, leaf, path->slots[0]-1, offset, end)) {
2088 fi = btrfs_item_ptr(leaf, path->slots[0],
2089 struct btrfs_file_extent_item);
2090 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2092 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2093 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2094 btrfs_set_file_extent_offset(leaf, fi, 0);
2095 btrfs_mark_buffer_dirty(leaf);
2099 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2102 key.offset = offset;
2103 btrfs_set_item_key_safe(root, path, &key);
2104 fi = btrfs_item_ptr(leaf, path->slots[0],
2105 struct btrfs_file_extent_item);
2106 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2108 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2109 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2110 btrfs_set_file_extent_offset(leaf, fi, 0);
2111 btrfs_mark_buffer_dirty(leaf);
2114 btrfs_release_path(path);
2116 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
2117 0, 0, end - offset, 0, end - offset,
2123 btrfs_release_path(path);
2125 hole_em = alloc_extent_map();
2127 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2128 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2129 &BTRFS_I(inode)->runtime_flags);
2131 hole_em->start = offset;
2132 hole_em->len = end - offset;
2133 hole_em->ram_bytes = hole_em->len;
2134 hole_em->orig_start = offset;
2136 hole_em->block_start = EXTENT_MAP_HOLE;
2137 hole_em->block_len = 0;
2138 hole_em->orig_block_len = 0;
2139 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
2140 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2141 hole_em->generation = trans->transid;
2144 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2145 write_lock(&em_tree->lock);
2146 ret = add_extent_mapping(em_tree, hole_em, 1);
2147 write_unlock(&em_tree->lock);
2148 } while (ret == -EEXIST);
2149 free_extent_map(hole_em);
2151 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2152 &BTRFS_I(inode)->runtime_flags);
2159 * Find a hole extent on given inode and change start/len to the end of hole
2160 * extent.(hole/vacuum extent whose em->start <= start &&
2161 * em->start + em->len > start)
2162 * When a hole extent is found, return 1 and modify start/len.
2164 static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)
2166 struct extent_map *em;
2169 em = btrfs_get_extent(inode, NULL, 0, *start, *len, 0);
2170 if (IS_ERR_OR_NULL(em)) {
2178 /* Hole or vacuum extent(only exists in no-hole mode) */
2179 if (em->block_start == EXTENT_MAP_HOLE) {
2181 *len = em->start + em->len > *start + *len ?
2182 0 : *start + *len - em->start - em->len;
2183 *start = em->start + em->len;
2185 free_extent_map(em);
2189 static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2191 struct btrfs_root *root = BTRFS_I(inode)->root;
2192 struct extent_state *cached_state = NULL;
2193 struct btrfs_path *path;
2194 struct btrfs_block_rsv *rsv;
2195 struct btrfs_trans_handle *trans;
2200 u64 orig_start = offset;
2202 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
2208 bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES);
2211 ret = btrfs_wait_ordered_range(inode, offset, len);
2215 mutex_lock(&inode->i_mutex);
2216 ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE);
2217 ret = find_first_non_hole(inode, &offset, &len);
2219 goto out_only_mutex;
2221 /* Already in a large hole */
2223 goto out_only_mutex;
2226 lockstart = round_up(offset, BTRFS_I(inode)->root->sectorsize);
2227 lockend = round_down(offset + len,
2228 BTRFS_I(inode)->root->sectorsize) - 1;
2229 same_page = ((offset >> PAGE_CACHE_SHIFT) ==
2230 ((offset + len - 1) >> PAGE_CACHE_SHIFT));
2233 * We needn't truncate any page which is beyond the end of the file
2234 * because we are sure there is no data there.
2237 * Only do this if we are in the same page and we aren't doing the
2240 if (same_page && len < PAGE_CACHE_SIZE) {
2241 if (offset < ino_size)
2242 ret = btrfs_truncate_page(inode, offset, len, 0);
2243 goto out_only_mutex;
2246 /* zero back part of the first page */
2247 if (offset < ino_size) {
2248 ret = btrfs_truncate_page(inode, offset, 0, 0);
2250 mutex_unlock(&inode->i_mutex);
2255 /* Check the aligned pages after the first unaligned page,
2256 * if offset != orig_start, which means the first unaligned page
2257 * including serveral following pages are already in holes,
2258 * the extra check can be skipped */
2259 if (offset == orig_start) {
2260 /* after truncate page, check hole again */
2261 len = offset + len - lockstart;
2263 ret = find_first_non_hole(inode, &offset, &len);
2265 goto out_only_mutex;
2268 goto out_only_mutex;
2273 /* Check the tail unaligned part is in a hole */
2274 tail_start = lockend + 1;
2275 tail_len = offset + len - tail_start;
2277 ret = find_first_non_hole(inode, &tail_start, &tail_len);
2278 if (unlikely(ret < 0))
2279 goto out_only_mutex;
2281 /* zero the front end of the last page */
2282 if (tail_start + tail_len < ino_size) {
2283 ret = btrfs_truncate_page(inode,
2284 tail_start + tail_len, 0, 1);
2286 goto out_only_mutex;
2291 if (lockend < lockstart) {
2292 mutex_unlock(&inode->i_mutex);
2297 struct btrfs_ordered_extent *ordered;
2299 truncate_pagecache_range(inode, lockstart, lockend);
2301 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2303 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2306 * We need to make sure we have no ordered extents in this range
2307 * and nobody raced in and read a page in this range, if we did
2308 * we need to try again.
2311 (ordered->file_offset + ordered->len <= lockstart ||
2312 ordered->file_offset > lockend)) &&
2313 !btrfs_page_exists_in_range(inode, lockstart, lockend)) {
2315 btrfs_put_ordered_extent(ordered);
2319 btrfs_put_ordered_extent(ordered);
2320 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2321 lockend, &cached_state, GFP_NOFS);
2322 ret = btrfs_wait_ordered_range(inode, lockstart,
2323 lockend - lockstart + 1);
2325 mutex_unlock(&inode->i_mutex);
2330 path = btrfs_alloc_path();
2336 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2341 rsv->size = btrfs_calc_trunc_metadata_size(root, 1);
2345 * 1 - update the inode
2346 * 1 - removing the extents in the range
2347 * 1 - adding the hole extent if no_holes isn't set
2349 rsv_count = no_holes ? 2 : 3;
2350 trans = btrfs_start_transaction(root, rsv_count);
2351 if (IS_ERR(trans)) {
2352 err = PTR_ERR(trans);
2356 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
2359 trans->block_rsv = rsv;
2361 cur_offset = lockstart;
2362 len = lockend - cur_offset;
2363 while (cur_offset < lockend) {
2364 ret = __btrfs_drop_extents(trans, root, inode, path,
2365 cur_offset, lockend + 1,
2366 &drop_end, 1, 0, 0, NULL);
2370 trans->block_rsv = &root->fs_info->trans_block_rsv;
2372 if (cur_offset < ino_size) {
2373 ret = fill_holes(trans, inode, path, cur_offset,
2381 cur_offset = drop_end;
2383 ret = btrfs_update_inode(trans, root, inode);
2389 btrfs_end_transaction(trans, root);
2390 btrfs_btree_balance_dirty(root);
2392 trans = btrfs_start_transaction(root, rsv_count);
2393 if (IS_ERR(trans)) {
2394 ret = PTR_ERR(trans);
2399 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
2401 BUG_ON(ret); /* shouldn't happen */
2402 trans->block_rsv = rsv;
2404 ret = find_first_non_hole(inode, &cur_offset, &len);
2405 if (unlikely(ret < 0))
2418 trans->block_rsv = &root->fs_info->trans_block_rsv;
2420 * Don't insert file hole extent item if it's for a range beyond eof
2421 * (because it's useless) or if it represents a 0 bytes range (when
2422 * cur_offset == drop_end).
2424 if (cur_offset < ino_size && cur_offset < drop_end) {
2425 ret = fill_holes(trans, inode, path, cur_offset, drop_end);
2436 inode_inc_iversion(inode);
2437 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2439 trans->block_rsv = &root->fs_info->trans_block_rsv;
2440 ret = btrfs_update_inode(trans, root, inode);
2441 btrfs_end_transaction(trans, root);
2442 btrfs_btree_balance_dirty(root);
2444 btrfs_free_path(path);
2445 btrfs_free_block_rsv(root, rsv);
2447 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2448 &cached_state, GFP_NOFS);
2450 mutex_unlock(&inode->i_mutex);
2456 static long btrfs_fallocate(struct file *file, int mode,
2457 loff_t offset, loff_t len)
2459 struct inode *inode = file_inode(file);
2460 struct extent_state *cached_state = NULL;
2461 struct btrfs_root *root = BTRFS_I(inode)->root;
2468 struct extent_map *em;
2469 int blocksize = BTRFS_I(inode)->root->sectorsize;
2472 alloc_start = round_down(offset, blocksize);
2473 alloc_end = round_up(offset + len, blocksize);
2475 /* Make sure we aren't being give some crap mode */
2476 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
2479 if (mode & FALLOC_FL_PUNCH_HOLE)
2480 return btrfs_punch_hole(inode, offset, len);
2483 * Make sure we have enough space before we do the
2486 ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
2489 if (root->fs_info->quota_enabled) {
2490 ret = btrfs_qgroup_reserve(root, alloc_end - alloc_start);
2492 goto out_reserve_fail;
2495 mutex_lock(&inode->i_mutex);
2496 ret = inode_newsize_ok(inode, alloc_end);
2500 if (alloc_start > inode->i_size) {
2501 ret = btrfs_cont_expand(inode, i_size_read(inode),
2507 * If we are fallocating from the end of the file onward we
2508 * need to zero out the end of the page if i_size lands in the
2511 ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
2517 * wait for ordered IO before we have any locks. We'll loop again
2518 * below with the locks held.
2520 ret = btrfs_wait_ordered_range(inode, alloc_start,
2521 alloc_end - alloc_start);
2525 locked_end = alloc_end - 1;
2527 struct btrfs_ordered_extent *ordered;
2529 /* the extent lock is ordered inside the running
2532 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
2533 locked_end, 0, &cached_state);
2534 ordered = btrfs_lookup_first_ordered_extent(inode,
2537 ordered->file_offset + ordered->len > alloc_start &&
2538 ordered->file_offset < alloc_end) {
2539 btrfs_put_ordered_extent(ordered);
2540 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
2541 alloc_start, locked_end,
2542 &cached_state, GFP_NOFS);
2544 * we can't wait on the range with the transaction
2545 * running or with the extent lock held
2547 ret = btrfs_wait_ordered_range(inode, alloc_start,
2548 alloc_end - alloc_start);
2553 btrfs_put_ordered_extent(ordered);
2558 cur_offset = alloc_start;
2562 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
2563 alloc_end - cur_offset, 0);
2564 if (IS_ERR_OR_NULL(em)) {
2571 last_byte = min(extent_map_end(em), alloc_end);
2572 actual_end = min_t(u64, extent_map_end(em), offset + len);
2573 last_byte = ALIGN(last_byte, blocksize);
2575 if (em->block_start == EXTENT_MAP_HOLE ||
2576 (cur_offset >= inode->i_size &&
2577 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
2578 ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
2579 last_byte - cur_offset,
2580 1 << inode->i_blkbits,
2585 free_extent_map(em);
2588 } else if (actual_end > inode->i_size &&
2589 !(mode & FALLOC_FL_KEEP_SIZE)) {
2591 * We didn't need to allocate any more space, but we
2592 * still extended the size of the file so we need to
2595 inode->i_ctime = CURRENT_TIME;
2596 i_size_write(inode, actual_end);
2597 btrfs_ordered_update_i_size(inode, actual_end, NULL);
2599 free_extent_map(em);
2601 cur_offset = last_byte;
2602 if (cur_offset >= alloc_end) {
2607 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
2608 &cached_state, GFP_NOFS);
2610 mutex_unlock(&inode->i_mutex);
2611 if (root->fs_info->quota_enabled)
2612 btrfs_qgroup_free(root, alloc_end - alloc_start);
2614 /* Let go of our reservation. */
2615 btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
2619 static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
2621 struct btrfs_root *root = BTRFS_I(inode)->root;
2622 struct extent_map *em = NULL;
2623 struct extent_state *cached_state = NULL;
2624 u64 lockstart = *offset;
2625 u64 lockend = i_size_read(inode);
2626 u64 start = *offset;
2627 u64 len = i_size_read(inode);
2630 lockend = max_t(u64, root->sectorsize, lockend);
2631 if (lockend <= lockstart)
2632 lockend = lockstart + root->sectorsize;
2635 len = lockend - lockstart + 1;
2637 len = max_t(u64, len, root->sectorsize);
2638 if (inode->i_size == 0)
2641 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0,
2644 while (start < inode->i_size) {
2645 em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
2652 if (whence == SEEK_HOLE &&
2653 (em->block_start == EXTENT_MAP_HOLE ||
2654 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
2656 else if (whence == SEEK_DATA &&
2657 (em->block_start != EXTENT_MAP_HOLE &&
2658 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
2661 start = em->start + em->len;
2662 free_extent_map(em);
2666 free_extent_map(em);
2668 if (whence == SEEK_DATA && start >= inode->i_size)
2671 *offset = min_t(loff_t, start, inode->i_size);
2673 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2674 &cached_state, GFP_NOFS);
2678 static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
2680 struct inode *inode = file->f_mapping->host;
2683 mutex_lock(&inode->i_mutex);
2687 offset = generic_file_llseek(file, offset, whence);
2691 if (offset >= i_size_read(inode)) {
2692 mutex_unlock(&inode->i_mutex);
2696 ret = find_desired_extent(inode, &offset, whence);
2698 mutex_unlock(&inode->i_mutex);
2703 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
2705 mutex_unlock(&inode->i_mutex);
2709 const struct file_operations btrfs_file_operations = {
2710 .llseek = btrfs_file_llseek,
2711 .read = new_sync_read,
2712 .write = new_sync_write,
2713 .read_iter = generic_file_read_iter,
2714 .splice_read = generic_file_splice_read,
2715 .write_iter = btrfs_file_write_iter,
2716 .mmap = btrfs_file_mmap,
2717 .open = generic_file_open,
2718 .release = btrfs_release_file,
2719 .fsync = btrfs_sync_file,
2720 .fallocate = btrfs_fallocate,
2721 .unlocked_ioctl = btrfs_ioctl,
2722 #ifdef CONFIG_COMPAT
2723 .compat_ioctl = btrfs_ioctl,
2727 void btrfs_auto_defrag_exit(void)
2729 if (btrfs_inode_defrag_cachep)
2730 kmem_cache_destroy(btrfs_inode_defrag_cachep);
2733 int btrfs_auto_defrag_init(void)
2735 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
2736 sizeof(struct inode_defrag), 0,
2737 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
2739 if (!btrfs_inode_defrag_cachep)