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/compat.h>
31 #include <linux/slab.h>
32 #include <linux/btrfs.h>
33 #include <linux/uio.h>
36 #include "transaction.h"
37 #include "btrfs_inode.h"
38 #include "print-tree.h"
43 #include "compression.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 btrfs_inode *inode,
96 struct inode_defrag *defrag)
98 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
99 struct inode_defrag *entry;
101 struct rb_node *parent = NULL;
104 p = &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, &inode->runtime_flags);
127 rb_link_node(&defrag->rb_node, parent, p);
128 rb_insert_color(&defrag->rb_node, &fs_info->defrag_inodes);
132 static inline int __need_auto_defrag(struct btrfs_fs_info *fs_info)
134 if (!btrfs_test_opt(fs_info, AUTO_DEFRAG))
137 if (btrfs_fs_closing(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,
148 struct btrfs_inode *inode)
150 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
151 struct btrfs_root *root = inode->root;
152 struct inode_defrag *defrag;
156 if (!__need_auto_defrag(fs_info))
159 if (test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags))
163 transid = trans->transid;
165 transid = inode->root->last_trans;
167 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
171 defrag->ino = btrfs_ino(inode);
172 defrag->transid = transid;
173 defrag->root = root->root_key.objectid;
175 spin_lock(&fs_info->defrag_inodes_lock);
176 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags)) {
178 * If we set IN_DEFRAG flag and evict the inode from memory,
179 * and then re-read this inode, this new inode doesn't have
180 * IN_DEFRAG flag. At the case, we may find the existed defrag.
182 ret = __btrfs_add_inode_defrag(inode, defrag);
184 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
186 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
188 spin_unlock(&fs_info->defrag_inodes_lock);
193 * Requeue the defrag object. If there is a defrag object that points to
194 * the same inode in the tree, we will merge them together (by
195 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
197 static void btrfs_requeue_inode_defrag(struct btrfs_inode *inode,
198 struct inode_defrag *defrag)
200 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
203 if (!__need_auto_defrag(fs_info))
207 * Here we don't check the IN_DEFRAG flag, because we need merge
210 spin_lock(&fs_info->defrag_inodes_lock);
211 ret = __btrfs_add_inode_defrag(inode, defrag);
212 spin_unlock(&fs_info->defrag_inodes_lock);
217 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
221 * pick the defragable inode that we want, if it doesn't exist, we will get
224 static struct inode_defrag *
225 btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
227 struct inode_defrag *entry = NULL;
228 struct inode_defrag tmp;
230 struct rb_node *parent = NULL;
236 spin_lock(&fs_info->defrag_inodes_lock);
237 p = fs_info->defrag_inodes.rb_node;
240 entry = rb_entry(parent, struct inode_defrag, rb_node);
242 ret = __compare_inode_defrag(&tmp, entry);
246 p = parent->rb_right;
251 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
252 parent = rb_next(parent);
254 entry = rb_entry(parent, struct inode_defrag, rb_node);
260 rb_erase(parent, &fs_info->defrag_inodes);
261 spin_unlock(&fs_info->defrag_inodes_lock);
265 void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
267 struct inode_defrag *defrag;
268 struct rb_node *node;
270 spin_lock(&fs_info->defrag_inodes_lock);
271 node = rb_first(&fs_info->defrag_inodes);
273 rb_erase(node, &fs_info->defrag_inodes);
274 defrag = rb_entry(node, struct inode_defrag, rb_node);
275 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
277 cond_resched_lock(&fs_info->defrag_inodes_lock);
279 node = rb_first(&fs_info->defrag_inodes);
281 spin_unlock(&fs_info->defrag_inodes_lock);
284 #define BTRFS_DEFRAG_BATCH 1024
286 static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
287 struct inode_defrag *defrag)
289 struct btrfs_root *inode_root;
291 struct btrfs_key key;
292 struct btrfs_ioctl_defrag_range_args range;
298 key.objectid = defrag->root;
299 key.type = BTRFS_ROOT_ITEM_KEY;
300 key.offset = (u64)-1;
302 index = srcu_read_lock(&fs_info->subvol_srcu);
304 inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
305 if (IS_ERR(inode_root)) {
306 ret = PTR_ERR(inode_root);
310 key.objectid = defrag->ino;
311 key.type = BTRFS_INODE_ITEM_KEY;
313 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
315 ret = PTR_ERR(inode);
318 srcu_read_unlock(&fs_info->subvol_srcu, index);
320 /* do a chunk of defrag */
321 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
322 memset(&range, 0, sizeof(range));
324 range.start = defrag->last_offset;
326 sb_start_write(fs_info->sb);
327 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
329 sb_end_write(fs_info->sb);
331 * if we filled the whole defrag batch, there
332 * must be more work to do. Queue this defrag
335 if (num_defrag == BTRFS_DEFRAG_BATCH) {
336 defrag->last_offset = range.start;
337 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
338 } else if (defrag->last_offset && !defrag->cycled) {
340 * we didn't fill our defrag batch, but
341 * we didn't start at zero. Make sure we loop
342 * around to the start of the file.
344 defrag->last_offset = 0;
346 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
348 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
354 srcu_read_unlock(&fs_info->subvol_srcu, index);
355 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
360 * run through the list of inodes in the FS that need
363 int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
365 struct inode_defrag *defrag;
367 u64 root_objectid = 0;
369 atomic_inc(&fs_info->defrag_running);
371 /* Pause the auto defragger. */
372 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
376 if (!__need_auto_defrag(fs_info))
379 /* find an inode to defrag */
380 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
383 if (root_objectid || first_ino) {
392 first_ino = defrag->ino + 1;
393 root_objectid = defrag->root;
395 __btrfs_run_defrag_inode(fs_info, defrag);
397 atomic_dec(&fs_info->defrag_running);
400 * during unmount, we use the transaction_wait queue to
401 * wait for the defragger to stop
403 wake_up(&fs_info->transaction_wait);
407 /* simple helper to fault in pages and copy. This should go away
408 * and be replaced with calls into generic code.
410 static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
411 struct page **prepared_pages,
415 size_t total_copied = 0;
417 int offset = pos & (PAGE_SIZE - 1);
419 while (write_bytes > 0) {
420 size_t count = min_t(size_t,
421 PAGE_SIZE - offset, write_bytes);
422 struct page *page = prepared_pages[pg];
424 * Copy data from userspace to the current page
426 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
428 /* Flush processor's dcache for this page */
429 flush_dcache_page(page);
432 * if we get a partial write, we can end up with
433 * partially up to date pages. These add
434 * a lot of complexity, so make sure they don't
435 * happen by forcing this copy to be retried.
437 * The rest of the btrfs_file_write code will fall
438 * back to page at a time copies after we return 0.
440 if (!PageUptodate(page) && copied < count)
443 iov_iter_advance(i, copied);
444 write_bytes -= copied;
445 total_copied += copied;
447 /* Return to btrfs_file_write_iter to fault page */
448 if (unlikely(copied == 0))
451 if (copied < PAGE_SIZE - offset) {
462 * unlocks pages after btrfs_file_write is done with them
464 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
467 for (i = 0; i < num_pages; i++) {
468 /* page checked is some magic around finding pages that
469 * have been modified without going through btrfs_set_page_dirty
470 * clear it here. There should be no need to mark the pages
471 * accessed as prepare_pages should have marked them accessed
472 * in prepare_pages via find_or_create_page()
474 ClearPageChecked(pages[i]);
475 unlock_page(pages[i]);
480 static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
483 struct extent_state **cached_state)
485 u64 search_start = start;
486 const u64 end = start + len - 1;
488 while (search_start < end) {
489 const u64 search_len = end - search_start + 1;
490 struct extent_map *em;
494 em = btrfs_get_extent(inode, NULL, 0, search_start,
499 if (em->block_start != EXTENT_MAP_HOLE)
503 if (em->start < search_start)
504 em_len -= search_start - em->start;
505 if (em_len > search_len)
508 ret = set_extent_bit(&inode->io_tree, search_start,
509 search_start + em_len - 1,
511 NULL, cached_state, GFP_NOFS);
513 search_start = extent_map_end(em);
522 * after copy_from_user, pages need to be dirtied and we need to make
523 * sure holes are created between the current EOF and the start of
524 * any next extents (if required).
526 * this also makes the decision about creating an inline extent vs
527 * doing real data extents, marking pages dirty and delalloc as required.
529 int btrfs_dirty_pages(struct inode *inode, struct page **pages,
530 size_t num_pages, loff_t pos, size_t write_bytes,
531 struct extent_state **cached)
533 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
538 u64 end_of_last_block;
539 u64 end_pos = pos + write_bytes;
540 loff_t isize = i_size_read(inode);
541 unsigned int extra_bits = 0;
543 start_pos = pos & ~((u64) fs_info->sectorsize - 1);
544 num_bytes = round_up(write_bytes + pos - start_pos,
545 fs_info->sectorsize);
547 end_of_last_block = start_pos + num_bytes - 1;
549 if (!btrfs_is_free_space_inode(BTRFS_I(inode))) {
550 if (start_pos >= isize &&
551 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) {
553 * There can't be any extents following eof in this case
554 * so just set the delalloc new bit for the range
557 extra_bits |= EXTENT_DELALLOC_NEW;
559 err = btrfs_find_new_delalloc_bytes(BTRFS_I(inode),
567 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
568 extra_bits, cached, 0);
572 for (i = 0; i < num_pages; i++) {
573 struct page *p = pages[i];
580 * we've only changed i_size in ram, and we haven't updated
581 * the disk i_size. There is no need to log the inode
585 i_size_write(inode, end_pos);
590 * this drops all the extents in the cache that intersect the range
591 * [start, end]. Existing extents are split as required.
593 void btrfs_drop_extent_cache(struct btrfs_inode *inode, u64 start, u64 end,
596 struct extent_map *em;
597 struct extent_map *split = NULL;
598 struct extent_map *split2 = NULL;
599 struct extent_map_tree *em_tree = &inode->extent_tree;
600 u64 len = end - start + 1;
608 WARN_ON(end < start);
609 if (end == (u64)-1) {
618 split = alloc_extent_map();
620 split2 = alloc_extent_map();
621 if (!split || !split2)
624 write_lock(&em_tree->lock);
625 em = lookup_extent_mapping(em_tree, start, len);
627 write_unlock(&em_tree->lock);
631 gen = em->generation;
632 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
633 if (testend && em->start + em->len >= start + len) {
635 write_unlock(&em_tree->lock);
638 start = em->start + em->len;
640 len = start + len - (em->start + em->len);
642 write_unlock(&em_tree->lock);
645 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
646 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
647 clear_bit(EXTENT_FLAG_LOGGING, &flags);
648 modified = !list_empty(&em->list);
652 if (em->start < start) {
653 split->start = em->start;
654 split->len = start - em->start;
656 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
657 split->orig_start = em->orig_start;
658 split->block_start = em->block_start;
661 split->block_len = em->block_len;
663 split->block_len = split->len;
664 split->orig_block_len = max(split->block_len,
666 split->ram_bytes = em->ram_bytes;
668 split->orig_start = split->start;
669 split->block_len = 0;
670 split->block_start = em->block_start;
671 split->orig_block_len = 0;
672 split->ram_bytes = split->len;
675 split->generation = gen;
676 split->bdev = em->bdev;
677 split->flags = flags;
678 split->compress_type = em->compress_type;
679 replace_extent_mapping(em_tree, em, split, modified);
680 free_extent_map(split);
684 if (testend && em->start + em->len > start + len) {
685 u64 diff = start + len - em->start;
687 split->start = start + len;
688 split->len = em->start + em->len - (start + len);
689 split->bdev = em->bdev;
690 split->flags = flags;
691 split->compress_type = em->compress_type;
692 split->generation = gen;
694 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
695 split->orig_block_len = max(em->block_len,
698 split->ram_bytes = em->ram_bytes;
700 split->block_len = em->block_len;
701 split->block_start = em->block_start;
702 split->orig_start = em->orig_start;
704 split->block_len = split->len;
705 split->block_start = em->block_start
707 split->orig_start = em->orig_start;
710 split->ram_bytes = split->len;
711 split->orig_start = split->start;
712 split->block_len = 0;
713 split->block_start = em->block_start;
714 split->orig_block_len = 0;
717 if (extent_map_in_tree(em)) {
718 replace_extent_mapping(em_tree, em, split,
721 ret = add_extent_mapping(em_tree, split,
723 ASSERT(ret == 0); /* Logic error */
725 free_extent_map(split);
729 if (extent_map_in_tree(em))
730 remove_extent_mapping(em_tree, em);
731 write_unlock(&em_tree->lock);
735 /* once for the tree*/
739 free_extent_map(split);
741 free_extent_map(split2);
745 * this is very complex, but the basic idea is to drop all extents
746 * in the range start - end. hint_block is filled in with a block number
747 * that would be a good hint to the block allocator for this file.
749 * If an extent intersects the range but is not entirely inside the range
750 * it is either truncated or split. Anything entirely inside the range
751 * is deleted from the tree.
753 int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
754 struct btrfs_root *root, struct inode *inode,
755 struct btrfs_path *path, u64 start, u64 end,
756 u64 *drop_end, int drop_cache,
758 u32 extent_item_size,
761 struct btrfs_fs_info *fs_info = root->fs_info;
762 struct extent_buffer *leaf;
763 struct btrfs_file_extent_item *fi;
764 struct btrfs_key key;
765 struct btrfs_key new_key;
766 u64 ino = btrfs_ino(BTRFS_I(inode));
767 u64 search_start = start;
770 u64 extent_offset = 0;
772 u64 last_end = start;
778 int modify_tree = -1;
781 int leafs_visited = 0;
784 btrfs_drop_extent_cache(BTRFS_I(inode), start, end - 1, 0);
786 if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent)
789 update_refs = (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
790 root == fs_info->tree_root);
793 ret = btrfs_lookup_file_extent(trans, root, path, ino,
794 search_start, modify_tree);
797 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
798 leaf = path->nodes[0];
799 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
800 if (key.objectid == ino &&
801 key.type == BTRFS_EXTENT_DATA_KEY)
807 leaf = path->nodes[0];
808 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
810 ret = btrfs_next_leaf(root, path);
818 leaf = path->nodes[0];
822 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
824 if (key.objectid > ino)
826 if (WARN_ON_ONCE(key.objectid < ino) ||
827 key.type < BTRFS_EXTENT_DATA_KEY) {
832 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
835 fi = btrfs_item_ptr(leaf, path->slots[0],
836 struct btrfs_file_extent_item);
837 extent_type = btrfs_file_extent_type(leaf, fi);
839 if (extent_type == BTRFS_FILE_EXTENT_REG ||
840 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
841 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
842 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
843 extent_offset = btrfs_file_extent_offset(leaf, fi);
844 extent_end = key.offset +
845 btrfs_file_extent_num_bytes(leaf, fi);
846 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
847 extent_end = key.offset +
848 btrfs_file_extent_inline_len(leaf,
856 * Don't skip extent items representing 0 byte lengths. They
857 * used to be created (bug) if while punching holes we hit
858 * -ENOSPC condition. So if we find one here, just ensure we
859 * delete it, otherwise we would insert a new file extent item
860 * with the same key (offset) as that 0 bytes length file
861 * extent item in the call to setup_items_for_insert() later
864 if (extent_end == key.offset && extent_end >= search_start) {
865 last_end = extent_end;
866 goto delete_extent_item;
869 if (extent_end <= search_start) {
875 search_start = max(key.offset, start);
876 if (recow || !modify_tree) {
878 btrfs_release_path(path);
883 * | - range to drop - |
884 * | -------- extent -------- |
886 if (start > key.offset && end < extent_end) {
888 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
893 memcpy(&new_key, &key, sizeof(new_key));
894 new_key.offset = start;
895 ret = btrfs_duplicate_item(trans, root, path,
897 if (ret == -EAGAIN) {
898 btrfs_release_path(path);
904 leaf = path->nodes[0];
905 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
906 struct btrfs_file_extent_item);
907 btrfs_set_file_extent_num_bytes(leaf, fi,
910 fi = btrfs_item_ptr(leaf, path->slots[0],
911 struct btrfs_file_extent_item);
913 extent_offset += start - key.offset;
914 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
915 btrfs_set_file_extent_num_bytes(leaf, fi,
917 btrfs_mark_buffer_dirty(leaf);
919 if (update_refs && disk_bytenr > 0) {
920 ret = btrfs_inc_extent_ref(trans, root,
921 disk_bytenr, num_bytes, 0,
922 root->root_key.objectid,
924 start - extent_offset);
925 BUG_ON(ret); /* -ENOMEM */
930 * From here on out we will have actually dropped something, so
931 * last_end can be updated.
933 last_end = extent_end;
936 * | ---- range to drop ----- |
937 * | -------- extent -------- |
939 if (start <= key.offset && end < extent_end) {
940 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
945 memcpy(&new_key, &key, sizeof(new_key));
946 new_key.offset = end;
947 btrfs_set_item_key_safe(fs_info, path, &new_key);
949 extent_offset += end - key.offset;
950 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
951 btrfs_set_file_extent_num_bytes(leaf, fi,
953 btrfs_mark_buffer_dirty(leaf);
954 if (update_refs && disk_bytenr > 0)
955 inode_sub_bytes(inode, end - key.offset);
959 search_start = extent_end;
961 * | ---- range to drop ----- |
962 * | -------- extent -------- |
964 if (start > key.offset && end >= extent_end) {
966 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
971 btrfs_set_file_extent_num_bytes(leaf, fi,
973 btrfs_mark_buffer_dirty(leaf);
974 if (update_refs && disk_bytenr > 0)
975 inode_sub_bytes(inode, extent_end - start);
976 if (end == extent_end)
984 * | ---- range to drop ----- |
985 * | ------ extent ------ |
987 if (start <= key.offset && end >= extent_end) {
990 del_slot = path->slots[0];
993 BUG_ON(del_slot + del_nr != path->slots[0]);
998 extent_type == BTRFS_FILE_EXTENT_INLINE) {
999 inode_sub_bytes(inode,
1000 extent_end - key.offset);
1001 extent_end = ALIGN(extent_end,
1002 fs_info->sectorsize);
1003 } else if (update_refs && disk_bytenr > 0) {
1004 ret = btrfs_free_extent(trans, root,
1005 disk_bytenr, num_bytes, 0,
1006 root->root_key.objectid,
1007 key.objectid, key.offset -
1009 BUG_ON(ret); /* -ENOMEM */
1010 inode_sub_bytes(inode,
1011 extent_end - key.offset);
1014 if (end == extent_end)
1017 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
1022 ret = btrfs_del_items(trans, root, path, del_slot,
1025 btrfs_abort_transaction(trans, ret);
1032 btrfs_release_path(path);
1039 if (!ret && del_nr > 0) {
1041 * Set path->slots[0] to first slot, so that after the delete
1042 * if items are move off from our leaf to its immediate left or
1043 * right neighbor leafs, we end up with a correct and adjusted
1044 * path->slots[0] for our insertion (if replace_extent != 0).
1046 path->slots[0] = del_slot;
1047 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1049 btrfs_abort_transaction(trans, ret);
1052 leaf = path->nodes[0];
1054 * If btrfs_del_items() was called, it might have deleted a leaf, in
1055 * which case it unlocked our path, so check path->locks[0] matches a
1058 if (!ret && replace_extent && leafs_visited == 1 &&
1059 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
1060 path->locks[0] == BTRFS_WRITE_LOCK) &&
1061 btrfs_leaf_free_space(fs_info, leaf) >=
1062 sizeof(struct btrfs_item) + extent_item_size) {
1065 key.type = BTRFS_EXTENT_DATA_KEY;
1067 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
1068 struct btrfs_key slot_key;
1070 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
1071 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
1074 setup_items_for_insert(root, path, &key,
1077 sizeof(struct btrfs_item) +
1078 extent_item_size, 1);
1082 if (!replace_extent || !(*key_inserted))
1083 btrfs_release_path(path);
1085 *drop_end = found ? min(end, last_end) : end;
1089 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
1090 struct btrfs_root *root, struct inode *inode, u64 start,
1091 u64 end, int drop_cache)
1093 struct btrfs_path *path;
1096 path = btrfs_alloc_path();
1099 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
1100 drop_cache, 0, 0, NULL);
1101 btrfs_free_path(path);
1105 static int extent_mergeable(struct extent_buffer *leaf, int slot,
1106 u64 objectid, u64 bytenr, u64 orig_offset,
1107 u64 *start, u64 *end)
1109 struct btrfs_file_extent_item *fi;
1110 struct btrfs_key key;
1113 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1116 btrfs_item_key_to_cpu(leaf, &key, slot);
1117 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1120 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1121 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1122 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1123 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1124 btrfs_file_extent_compression(leaf, fi) ||
1125 btrfs_file_extent_encryption(leaf, fi) ||
1126 btrfs_file_extent_other_encoding(leaf, fi))
1129 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1130 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1133 *start = key.offset;
1139 * Mark extent in the range start - end as written.
1141 * This changes extent type from 'pre-allocated' to 'regular'. If only
1142 * part of extent is marked as written, the extent will be split into
1145 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1146 struct btrfs_inode *inode, u64 start, u64 end)
1148 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1149 struct btrfs_root *root = inode->root;
1150 struct extent_buffer *leaf;
1151 struct btrfs_path *path;
1152 struct btrfs_file_extent_item *fi;
1153 struct btrfs_key key;
1154 struct btrfs_key new_key;
1166 u64 ino = btrfs_ino(inode);
1168 path = btrfs_alloc_path();
1175 key.type = BTRFS_EXTENT_DATA_KEY;
1178 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1181 if (ret > 0 && path->slots[0] > 0)
1184 leaf = path->nodes[0];
1185 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1186 if (key.objectid != ino ||
1187 key.type != BTRFS_EXTENT_DATA_KEY) {
1189 btrfs_abort_transaction(trans, ret);
1192 fi = btrfs_item_ptr(leaf, path->slots[0],
1193 struct btrfs_file_extent_item);
1194 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) {
1196 btrfs_abort_transaction(trans, ret);
1199 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1200 if (key.offset > start || extent_end < end) {
1202 btrfs_abort_transaction(trans, ret);
1206 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1207 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1208 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1209 memcpy(&new_key, &key, sizeof(new_key));
1211 if (start == key.offset && end < extent_end) {
1214 if (extent_mergeable(leaf, path->slots[0] - 1,
1215 ino, bytenr, orig_offset,
1216 &other_start, &other_end)) {
1217 new_key.offset = end;
1218 btrfs_set_item_key_safe(fs_info, path, &new_key);
1219 fi = btrfs_item_ptr(leaf, path->slots[0],
1220 struct btrfs_file_extent_item);
1221 btrfs_set_file_extent_generation(leaf, fi,
1223 btrfs_set_file_extent_num_bytes(leaf, fi,
1225 btrfs_set_file_extent_offset(leaf, fi,
1227 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1228 struct btrfs_file_extent_item);
1229 btrfs_set_file_extent_generation(leaf, fi,
1231 btrfs_set_file_extent_num_bytes(leaf, fi,
1233 btrfs_mark_buffer_dirty(leaf);
1238 if (start > key.offset && end == extent_end) {
1241 if (extent_mergeable(leaf, path->slots[0] + 1,
1242 ino, bytenr, orig_offset,
1243 &other_start, &other_end)) {
1244 fi = btrfs_item_ptr(leaf, path->slots[0],
1245 struct btrfs_file_extent_item);
1246 btrfs_set_file_extent_num_bytes(leaf, fi,
1247 start - key.offset);
1248 btrfs_set_file_extent_generation(leaf, fi,
1251 new_key.offset = start;
1252 btrfs_set_item_key_safe(fs_info, path, &new_key);
1254 fi = btrfs_item_ptr(leaf, path->slots[0],
1255 struct btrfs_file_extent_item);
1256 btrfs_set_file_extent_generation(leaf, fi,
1258 btrfs_set_file_extent_num_bytes(leaf, fi,
1260 btrfs_set_file_extent_offset(leaf, fi,
1261 start - orig_offset);
1262 btrfs_mark_buffer_dirty(leaf);
1267 while (start > key.offset || end < extent_end) {
1268 if (key.offset == start)
1271 new_key.offset = split;
1272 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1273 if (ret == -EAGAIN) {
1274 btrfs_release_path(path);
1278 btrfs_abort_transaction(trans, ret);
1282 leaf = path->nodes[0];
1283 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1284 struct btrfs_file_extent_item);
1285 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1286 btrfs_set_file_extent_num_bytes(leaf, fi,
1287 split - key.offset);
1289 fi = btrfs_item_ptr(leaf, path->slots[0],
1290 struct btrfs_file_extent_item);
1292 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1293 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1294 btrfs_set_file_extent_num_bytes(leaf, fi,
1295 extent_end - split);
1296 btrfs_mark_buffer_dirty(leaf);
1298 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes,
1299 0, root->root_key.objectid,
1302 btrfs_abort_transaction(trans, ret);
1306 if (split == start) {
1309 if (start != key.offset) {
1311 btrfs_abort_transaction(trans, ret);
1322 if (extent_mergeable(leaf, path->slots[0] + 1,
1323 ino, bytenr, orig_offset,
1324 &other_start, &other_end)) {
1326 btrfs_release_path(path);
1329 extent_end = other_end;
1330 del_slot = path->slots[0] + 1;
1332 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1333 0, root->root_key.objectid,
1336 btrfs_abort_transaction(trans, ret);
1342 if (extent_mergeable(leaf, path->slots[0] - 1,
1343 ino, bytenr, orig_offset,
1344 &other_start, &other_end)) {
1346 btrfs_release_path(path);
1349 key.offset = other_start;
1350 del_slot = path->slots[0];
1352 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1353 0, root->root_key.objectid,
1356 btrfs_abort_transaction(trans, ret);
1361 fi = btrfs_item_ptr(leaf, path->slots[0],
1362 struct btrfs_file_extent_item);
1363 btrfs_set_file_extent_type(leaf, fi,
1364 BTRFS_FILE_EXTENT_REG);
1365 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1366 btrfs_mark_buffer_dirty(leaf);
1368 fi = btrfs_item_ptr(leaf, del_slot - 1,
1369 struct btrfs_file_extent_item);
1370 btrfs_set_file_extent_type(leaf, fi,
1371 BTRFS_FILE_EXTENT_REG);
1372 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1373 btrfs_set_file_extent_num_bytes(leaf, fi,
1374 extent_end - key.offset);
1375 btrfs_mark_buffer_dirty(leaf);
1377 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1379 btrfs_abort_transaction(trans, ret);
1384 btrfs_free_path(path);
1389 * on error we return an unlocked page and the error value
1390 * on success we return a locked page and 0
1392 static int prepare_uptodate_page(struct inode *inode,
1393 struct page *page, u64 pos,
1394 bool force_uptodate)
1398 if (((pos & (PAGE_SIZE - 1)) || force_uptodate) &&
1399 !PageUptodate(page)) {
1400 ret = btrfs_readpage(NULL, page);
1404 if (!PageUptodate(page)) {
1408 if (page->mapping != inode->i_mapping) {
1417 * this just gets pages into the page cache and locks them down.
1419 static noinline int prepare_pages(struct inode *inode, struct page **pages,
1420 size_t num_pages, loff_t pos,
1421 size_t write_bytes, bool force_uptodate)
1424 unsigned long index = pos >> PAGE_SHIFT;
1425 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1429 for (i = 0; i < num_pages; i++) {
1431 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1432 mask | __GFP_WRITE);
1440 err = prepare_uptodate_page(inode, pages[i], pos,
1442 if (!err && i == num_pages - 1)
1443 err = prepare_uptodate_page(inode, pages[i],
1444 pos + write_bytes, false);
1447 if (err == -EAGAIN) {
1454 wait_on_page_writeback(pages[i]);
1459 while (faili >= 0) {
1460 unlock_page(pages[faili]);
1461 put_page(pages[faili]);
1469 * This function locks the extent and properly waits for data=ordered extents
1470 * to finish before allowing the pages to be modified if need.
1473 * 1 - the extent is locked
1474 * 0 - the extent is not locked, and everything is OK
1475 * -EAGAIN - need re-prepare the pages
1476 * the other < 0 number - Something wrong happens
1479 lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
1480 size_t num_pages, loff_t pos,
1482 u64 *lockstart, u64 *lockend,
1483 struct extent_state **cached_state)
1485 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1491 start_pos = round_down(pos, fs_info->sectorsize);
1492 last_pos = start_pos
1493 + round_up(pos + write_bytes - start_pos,
1494 fs_info->sectorsize) - 1;
1496 if (start_pos < inode->vfs_inode.i_size) {
1497 struct btrfs_ordered_extent *ordered;
1499 lock_extent_bits(&inode->io_tree, start_pos, last_pos,
1501 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1502 last_pos - start_pos + 1);
1504 ordered->file_offset + ordered->len > start_pos &&
1505 ordered->file_offset <= last_pos) {
1506 unlock_extent_cached(&inode->io_tree, start_pos,
1507 last_pos, cached_state, GFP_NOFS);
1508 for (i = 0; i < num_pages; i++) {
1509 unlock_page(pages[i]);
1512 btrfs_start_ordered_extent(&inode->vfs_inode,
1514 btrfs_put_ordered_extent(ordered);
1518 btrfs_put_ordered_extent(ordered);
1519 clear_extent_bit(&inode->io_tree, start_pos, last_pos,
1520 EXTENT_DIRTY | EXTENT_DELALLOC |
1521 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
1522 0, 0, cached_state, GFP_NOFS);
1523 *lockstart = start_pos;
1524 *lockend = last_pos;
1528 for (i = 0; i < num_pages; i++) {
1529 if (clear_page_dirty_for_io(pages[i]))
1530 account_page_redirty(pages[i]);
1531 set_page_extent_mapped(pages[i]);
1532 WARN_ON(!PageLocked(pages[i]));
1538 static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
1539 size_t *write_bytes)
1541 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1542 struct btrfs_root *root = inode->root;
1543 struct btrfs_ordered_extent *ordered;
1544 u64 lockstart, lockend;
1548 ret = btrfs_start_write_no_snapshotting(root);
1552 lockstart = round_down(pos, fs_info->sectorsize);
1553 lockend = round_up(pos + *write_bytes,
1554 fs_info->sectorsize) - 1;
1557 lock_extent(&inode->io_tree, lockstart, lockend);
1558 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1559 lockend - lockstart + 1);
1563 unlock_extent(&inode->io_tree, lockstart, lockend);
1564 btrfs_start_ordered_extent(&inode->vfs_inode, ordered, 1);
1565 btrfs_put_ordered_extent(ordered);
1568 num_bytes = lockend - lockstart + 1;
1569 ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
1573 btrfs_end_write_no_snapshotting(root);
1575 *write_bytes = min_t(size_t, *write_bytes ,
1576 num_bytes - pos + lockstart);
1579 unlock_extent(&inode->io_tree, lockstart, lockend);
1584 static noinline ssize_t __btrfs_buffered_write(struct file *file,
1588 struct inode *inode = file_inode(file);
1589 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1590 struct btrfs_root *root = BTRFS_I(inode)->root;
1591 struct page **pages = NULL;
1592 struct extent_state *cached_state = NULL;
1593 struct extent_changeset *data_reserved = NULL;
1594 u64 release_bytes = 0;
1597 size_t num_written = 0;
1600 bool only_release_metadata = false;
1601 bool force_page_uptodate = false;
1603 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
1604 PAGE_SIZE / (sizeof(struct page *)));
1605 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1606 nrptrs = max(nrptrs, 8);
1607 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1611 while (iov_iter_count(i) > 0) {
1612 size_t offset = pos & (PAGE_SIZE - 1);
1613 size_t sector_offset;
1614 size_t write_bytes = min(iov_iter_count(i),
1615 nrptrs * (size_t)PAGE_SIZE -
1617 size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
1619 size_t reserve_bytes;
1622 size_t dirty_sectors;
1626 WARN_ON(num_pages > nrptrs);
1629 * Fault pages before locking them in prepare_pages
1630 * to avoid recursive lock
1632 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1637 sector_offset = pos & (fs_info->sectorsize - 1);
1638 reserve_bytes = round_up(write_bytes + sector_offset,
1639 fs_info->sectorsize);
1641 extent_changeset_release(data_reserved);
1642 ret = btrfs_check_data_free_space(inode, &data_reserved, pos,
1645 if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1646 BTRFS_INODE_PREALLOC)) &&
1647 check_can_nocow(BTRFS_I(inode), pos,
1648 &write_bytes) > 0) {
1650 * For nodata cow case, no need to reserve
1653 only_release_metadata = true;
1655 * our prealloc extent may be smaller than
1656 * write_bytes, so scale down.
1658 num_pages = DIV_ROUND_UP(write_bytes + offset,
1660 reserve_bytes = round_up(write_bytes +
1662 fs_info->sectorsize);
1668 WARN_ON(reserve_bytes == 0);
1669 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
1672 if (!only_release_metadata)
1673 btrfs_free_reserved_data_space(inode,
1677 btrfs_end_write_no_snapshotting(root);
1681 release_bytes = reserve_bytes;
1684 * This is going to setup the pages array with the number of
1685 * pages we want, so we don't really need to worry about the
1686 * contents of pages from loop to loop
1688 ret = prepare_pages(inode, pages, num_pages,
1690 force_page_uptodate);
1692 btrfs_delalloc_release_extents(BTRFS_I(inode),
1697 extents_locked = lock_and_cleanup_extent_if_need(
1698 BTRFS_I(inode), pages,
1699 num_pages, pos, write_bytes, &lockstart,
1700 &lockend, &cached_state);
1701 if (extents_locked < 0) {
1702 if (extents_locked == -EAGAIN)
1704 btrfs_delalloc_release_extents(BTRFS_I(inode),
1706 ret = extents_locked;
1710 copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
1712 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes);
1713 dirty_sectors = round_up(copied + sector_offset,
1714 fs_info->sectorsize);
1715 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors);
1718 * if we have trouble faulting in the pages, fall
1719 * back to one page at a time
1721 if (copied < write_bytes)
1725 force_page_uptodate = true;
1729 force_page_uptodate = false;
1730 dirty_pages = DIV_ROUND_UP(copied + offset,
1734 if (num_sectors > dirty_sectors) {
1735 /* release everything except the sectors we dirtied */
1736 release_bytes -= dirty_sectors <<
1737 fs_info->sb->s_blocksize_bits;
1738 if (only_release_metadata) {
1739 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1744 __pos = round_down(pos,
1745 fs_info->sectorsize) +
1746 (dirty_pages << PAGE_SHIFT);
1747 btrfs_delalloc_release_space(inode,
1748 data_reserved, __pos,
1753 release_bytes = round_up(copied + sector_offset,
1754 fs_info->sectorsize);
1757 ret = btrfs_dirty_pages(inode, pages, dirty_pages,
1760 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1761 lockstart, lockend, &cached_state,
1763 btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes);
1765 btrfs_drop_pages(pages, num_pages);
1770 if (only_release_metadata)
1771 btrfs_end_write_no_snapshotting(root);
1773 if (only_release_metadata && copied > 0) {
1774 lockstart = round_down(pos,
1775 fs_info->sectorsize);
1776 lockend = round_up(pos + copied,
1777 fs_info->sectorsize) - 1;
1779 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1780 lockend, EXTENT_NORESERVE, NULL,
1782 only_release_metadata = false;
1785 btrfs_drop_pages(pages, num_pages);
1789 balance_dirty_pages_ratelimited(inode->i_mapping);
1790 if (dirty_pages < (fs_info->nodesize >> PAGE_SHIFT) + 1)
1791 btrfs_btree_balance_dirty(fs_info);
1794 num_written += copied;
1799 if (release_bytes) {
1800 if (only_release_metadata) {
1801 btrfs_end_write_no_snapshotting(root);
1802 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1805 btrfs_delalloc_release_space(inode, data_reserved,
1806 round_down(pos, fs_info->sectorsize),
1811 extent_changeset_free(data_reserved);
1812 return num_written ? num_written : ret;
1815 static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
1817 struct file *file = iocb->ki_filp;
1818 struct inode *inode = file_inode(file);
1819 loff_t pos = iocb->ki_pos;
1821 ssize_t written_buffered;
1825 written = generic_file_direct_write(iocb, from);
1827 if (written < 0 || !iov_iter_count(from))
1831 written_buffered = __btrfs_buffered_write(file, from, pos);
1832 if (written_buffered < 0) {
1833 err = written_buffered;
1837 * Ensure all data is persisted. We want the next direct IO read to be
1838 * able to read what was just written.
1840 endbyte = pos + written_buffered - 1;
1841 err = btrfs_fdatawrite_range(inode, pos, endbyte);
1844 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
1847 written += written_buffered;
1848 iocb->ki_pos = pos + written_buffered;
1849 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
1850 endbyte >> PAGE_SHIFT);
1852 return written ? written : err;
1855 static void update_time_for_write(struct inode *inode)
1857 struct timespec now;
1859 if (IS_NOCMTIME(inode))
1862 now = current_time(inode);
1863 if (!timespec_equal(&inode->i_mtime, &now))
1864 inode->i_mtime = now;
1866 if (!timespec_equal(&inode->i_ctime, &now))
1867 inode->i_ctime = now;
1869 if (IS_I_VERSION(inode))
1870 inode_inc_iversion(inode);
1873 static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1874 struct iov_iter *from)
1876 struct file *file = iocb->ki_filp;
1877 struct inode *inode = file_inode(file);
1878 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1879 struct btrfs_root *root = BTRFS_I(inode)->root;
1882 ssize_t num_written = 0;
1883 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
1886 size_t count = iov_iter_count(from);
1890 if (!(iocb->ki_flags & IOCB_DIRECT) &&
1891 (iocb->ki_flags & IOCB_NOWAIT))
1894 if (!inode_trylock(inode)) {
1895 if (iocb->ki_flags & IOCB_NOWAIT)
1900 err = generic_write_checks(iocb, from);
1902 inode_unlock(inode);
1907 if (iocb->ki_flags & IOCB_NOWAIT) {
1909 * We will allocate space in case nodatacow is not set,
1912 if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1913 BTRFS_INODE_PREALLOC)) ||
1914 check_can_nocow(BTRFS_I(inode), pos, &count) <= 0) {
1915 inode_unlock(inode);
1920 current->backing_dev_info = inode_to_bdi(inode);
1921 err = file_remove_privs(file);
1923 inode_unlock(inode);
1928 * If BTRFS flips readonly due to some impossible error
1929 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1930 * although we have opened a file as writable, we have
1931 * to stop this write operation to ensure FS consistency.
1933 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1934 inode_unlock(inode);
1940 * We reserve space for updating the inode when we reserve space for the
1941 * extent we are going to write, so we will enospc out there. We don't
1942 * need to start yet another transaction to update the inode as we will
1943 * update the inode when we finish writing whatever data we write.
1945 update_time_for_write(inode);
1947 start_pos = round_down(pos, fs_info->sectorsize);
1948 oldsize = i_size_read(inode);
1949 if (start_pos > oldsize) {
1950 /* Expand hole size to cover write data, preventing empty gap */
1951 end_pos = round_up(pos + count,
1952 fs_info->sectorsize);
1953 err = btrfs_cont_expand(inode, oldsize, end_pos);
1955 inode_unlock(inode);
1958 if (start_pos > round_up(oldsize, fs_info->sectorsize))
1963 atomic_inc(&BTRFS_I(inode)->sync_writers);
1965 if (iocb->ki_flags & IOCB_DIRECT) {
1966 num_written = __btrfs_direct_write(iocb, from);
1968 num_written = __btrfs_buffered_write(file, from, pos);
1969 if (num_written > 0)
1970 iocb->ki_pos = pos + num_written;
1972 pagecache_isize_extended(inode, oldsize,
1973 i_size_read(inode));
1976 inode_unlock(inode);
1979 * We also have to set last_sub_trans to the current log transid,
1980 * otherwise subsequent syncs to a file that's been synced in this
1981 * transaction will appear to have already occurred.
1983 spin_lock(&BTRFS_I(inode)->lock);
1984 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1985 spin_unlock(&BTRFS_I(inode)->lock);
1986 if (num_written > 0)
1987 num_written = generic_write_sync(iocb, num_written);
1990 atomic_dec(&BTRFS_I(inode)->sync_writers);
1992 current->backing_dev_info = NULL;
1993 return num_written ? num_written : err;
1996 int btrfs_release_file(struct inode *inode, struct file *filp)
1998 struct btrfs_file_private *private = filp->private_data;
2000 if (private && private->trans)
2001 btrfs_ioctl_trans_end(filp);
2002 if (private && private->filldir_buf)
2003 kfree(private->filldir_buf);
2005 filp->private_data = NULL;
2008 * ordered_data_close is set by settattr when we are about to truncate
2009 * a file from a non-zero size to a zero size. This tries to
2010 * flush down new bytes that may have been written if the
2011 * application were using truncate to replace a file in place.
2013 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
2014 &BTRFS_I(inode)->runtime_flags))
2015 filemap_flush(inode->i_mapping);
2019 static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
2023 atomic_inc(&BTRFS_I(inode)->sync_writers);
2024 ret = btrfs_fdatawrite_range(inode, start, end);
2025 atomic_dec(&BTRFS_I(inode)->sync_writers);
2031 * fsync call for both files and directories. This logs the inode into
2032 * the tree log instead of forcing full commits whenever possible.
2034 * It needs to call filemap_fdatawait so that all ordered extent updates are
2035 * in the metadata btree are up to date for copying to the log.
2037 * It drops the inode mutex before doing the tree log commit. This is an
2038 * important optimization for directories because holding the mutex prevents
2039 * new operations on the dir while we write to disk.
2041 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
2043 struct dentry *dentry = file_dentry(file);
2044 struct inode *inode = d_inode(dentry);
2045 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2046 struct btrfs_root *root = BTRFS_I(inode)->root;
2047 struct btrfs_trans_handle *trans;
2048 struct btrfs_log_ctx ctx;
2050 bool full_sync = false;
2054 * The range length can be represented by u64, we have to do the typecasts
2055 * to avoid signed overflow if it's [0, LLONG_MAX] eg. from fsync()
2057 len = (u64)end - (u64)start + 1;
2058 trace_btrfs_sync_file(file, datasync);
2060 btrfs_init_log_ctx(&ctx, inode);
2063 * We write the dirty pages in the range and wait until they complete
2064 * out of the ->i_mutex. If so, we can flush the dirty pages by
2065 * multi-task, and make the performance up. See
2066 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
2068 ret = start_ordered_ops(inode, start, end);
2073 atomic_inc(&root->log_batch);
2074 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2075 &BTRFS_I(inode)->runtime_flags);
2077 * We might have have had more pages made dirty after calling
2078 * start_ordered_ops and before acquiring the inode's i_mutex.
2082 * For a full sync, we need to make sure any ordered operations
2083 * start and finish before we start logging the inode, so that
2084 * all extents are persisted and the respective file extent
2085 * items are in the fs/subvol btree.
2087 ret = btrfs_wait_ordered_range(inode, start, len);
2090 * Start any new ordered operations before starting to log the
2091 * inode. We will wait for them to finish in btrfs_sync_log().
2093 * Right before acquiring the inode's mutex, we might have new
2094 * writes dirtying pages, which won't immediately start the
2095 * respective ordered operations - that is done through the
2096 * fill_delalloc callbacks invoked from the writepage and
2097 * writepages address space operations. So make sure we start
2098 * all ordered operations before starting to log our inode. Not
2099 * doing this means that while logging the inode, writeback
2100 * could start and invoke writepage/writepages, which would call
2101 * the fill_delalloc callbacks (cow_file_range,
2102 * submit_compressed_extents). These callbacks add first an
2103 * extent map to the modified list of extents and then create
2104 * the respective ordered operation, which means in
2105 * tree-log.c:btrfs_log_inode() we might capture all existing
2106 * ordered operations (with btrfs_get_logged_extents()) before
2107 * the fill_delalloc callback adds its ordered operation, and by
2108 * the time we visit the modified list of extent maps (with
2109 * btrfs_log_changed_extents()), we see and process the extent
2110 * map they created. We then use the extent map to construct a
2111 * file extent item for logging without waiting for the
2112 * respective ordered operation to finish - this file extent
2113 * item points to a disk location that might not have yet been
2114 * written to, containing random data - so after a crash a log
2115 * replay will make our inode have file extent items that point
2116 * to disk locations containing invalid data, as we returned
2117 * success to userspace without waiting for the respective
2118 * ordered operation to finish, because it wasn't captured by
2119 * btrfs_get_logged_extents().
2121 ret = start_ordered_ops(inode, start, end);
2124 inode_unlock(inode);
2127 atomic_inc(&root->log_batch);
2130 * If the last transaction that changed this file was before the current
2131 * transaction and we have the full sync flag set in our inode, we can
2132 * bail out now without any syncing.
2134 * Note that we can't bail out if the full sync flag isn't set. This is
2135 * because when the full sync flag is set we start all ordered extents
2136 * and wait for them to fully complete - when they complete they update
2137 * the inode's last_trans field through:
2139 * btrfs_finish_ordered_io() ->
2140 * btrfs_update_inode_fallback() ->
2141 * btrfs_update_inode() ->
2142 * btrfs_set_inode_last_trans()
2144 * So we are sure that last_trans is up to date and can do this check to
2145 * bail out safely. For the fast path, when the full sync flag is not
2146 * set in our inode, we can not do it because we start only our ordered
2147 * extents and don't wait for them to complete (that is when
2148 * btrfs_finish_ordered_io runs), so here at this point their last_trans
2149 * value might be less than or equals to fs_info->last_trans_committed,
2150 * and setting a speculative last_trans for an inode when a buffered
2151 * write is made (such as fs_info->generation + 1 for example) would not
2152 * be reliable since after setting the value and before fsync is called
2153 * any number of transactions can start and commit (transaction kthread
2154 * commits the current transaction periodically), and a transaction
2155 * commit does not start nor waits for ordered extents to complete.
2158 if (btrfs_inode_in_log(BTRFS_I(inode), fs_info->generation) ||
2159 (full_sync && BTRFS_I(inode)->last_trans <=
2160 fs_info->last_trans_committed) ||
2161 (!btrfs_have_ordered_extents_in_range(inode, start, len) &&
2162 BTRFS_I(inode)->last_trans
2163 <= fs_info->last_trans_committed)) {
2165 * We've had everything committed since the last time we were
2166 * modified so clear this flag in case it was set for whatever
2167 * reason, it's no longer relevant.
2169 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2170 &BTRFS_I(inode)->runtime_flags);
2172 * An ordered extent might have started before and completed
2173 * already with io errors, in which case the inode was not
2174 * updated and we end up here. So check the inode's mapping
2175 * for any errors that might have happened since we last
2176 * checked called fsync.
2178 ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err);
2179 inode_unlock(inode);
2184 * ok we haven't committed the transaction yet, lets do a commit
2186 if (file->private_data)
2187 btrfs_ioctl_trans_end(file);
2190 * We use start here because we will need to wait on the IO to complete
2191 * in btrfs_sync_log, which could require joining a transaction (for
2192 * example checking cross references in the nocow path). If we use join
2193 * here we could get into a situation where we're waiting on IO to
2194 * happen that is blocked on a transaction trying to commit. With start
2195 * we inc the extwriter counter, so we wait for all extwriters to exit
2196 * before we start blocking join'ers. This comment is to keep somebody
2197 * from thinking they are super smart and changing this to
2198 * btrfs_join_transaction *cough*Josef*cough*.
2200 trans = btrfs_start_transaction(root, 0);
2201 if (IS_ERR(trans)) {
2202 ret = PTR_ERR(trans);
2203 inode_unlock(inode);
2208 ret = btrfs_log_dentry_safe(trans, root, dentry, start, end, &ctx);
2210 /* Fallthrough and commit/free transaction. */
2214 /* we've logged all the items and now have a consistent
2215 * version of the file in the log. It is possible that
2216 * someone will come in and modify the file, but that's
2217 * fine because the log is consistent on disk, and we
2218 * have references to all of the file's extents
2220 * It is possible that someone will come in and log the
2221 * file again, but that will end up using the synchronization
2222 * inside btrfs_sync_log to keep things safe.
2224 inode_unlock(inode);
2227 * If any of the ordered extents had an error, just return it to user
2228 * space, so that the application knows some writes didn't succeed and
2229 * can take proper action (retry for e.g.). Blindly committing the
2230 * transaction in this case, would fool userspace that everything was
2231 * successful. And we also want to make sure our log doesn't contain
2232 * file extent items pointing to extents that weren't fully written to -
2233 * just like in the non fast fsync path, where we check for the ordered
2234 * operation's error flag before writing to the log tree and return -EIO
2235 * if any of them had this flag set (btrfs_wait_ordered_range) -
2236 * therefore we need to check for errors in the ordered operations,
2237 * which are indicated by ctx.io_err.
2240 btrfs_end_transaction(trans);
2245 if (ret != BTRFS_NO_LOG_SYNC) {
2247 ret = btrfs_sync_log(trans, root, &ctx);
2249 ret = btrfs_end_transaction(trans);
2254 ret = btrfs_wait_ordered_range(inode, start, len);
2256 btrfs_end_transaction(trans);
2260 ret = btrfs_commit_transaction(trans);
2262 ret = btrfs_end_transaction(trans);
2265 ASSERT(list_empty(&ctx.list));
2266 err = file_check_and_advance_wb_err(file);
2269 return ret > 0 ? -EIO : ret;
2272 static const struct vm_operations_struct btrfs_file_vm_ops = {
2273 .fault = filemap_fault,
2274 .map_pages = filemap_map_pages,
2275 .page_mkwrite = btrfs_page_mkwrite,
2278 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2280 struct address_space *mapping = filp->f_mapping;
2282 if (!mapping->a_ops->readpage)
2285 file_accessed(filp);
2286 vma->vm_ops = &btrfs_file_vm_ops;
2291 static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf,
2292 int slot, u64 start, u64 end)
2294 struct btrfs_file_extent_item *fi;
2295 struct btrfs_key key;
2297 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2300 btrfs_item_key_to_cpu(leaf, &key, slot);
2301 if (key.objectid != btrfs_ino(inode) ||
2302 key.type != BTRFS_EXTENT_DATA_KEY)
2305 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2307 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2310 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2313 if (key.offset == end)
2315 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2320 static int fill_holes(struct btrfs_trans_handle *trans,
2321 struct btrfs_inode *inode,
2322 struct btrfs_path *path, u64 offset, u64 end)
2324 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
2325 struct btrfs_root *root = inode->root;
2326 struct extent_buffer *leaf;
2327 struct btrfs_file_extent_item *fi;
2328 struct extent_map *hole_em;
2329 struct extent_map_tree *em_tree = &inode->extent_tree;
2330 struct btrfs_key key;
2333 if (btrfs_fs_incompat(fs_info, NO_HOLES))
2336 key.objectid = btrfs_ino(inode);
2337 key.type = BTRFS_EXTENT_DATA_KEY;
2338 key.offset = offset;
2340 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2343 * We should have dropped this offset, so if we find it then
2344 * something has gone horribly wrong.
2351 leaf = path->nodes[0];
2352 if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) {
2356 fi = btrfs_item_ptr(leaf, path->slots[0],
2357 struct btrfs_file_extent_item);
2358 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2360 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2361 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2362 btrfs_set_file_extent_offset(leaf, fi, 0);
2363 btrfs_mark_buffer_dirty(leaf);
2367 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2370 key.offset = offset;
2371 btrfs_set_item_key_safe(fs_info, path, &key);
2372 fi = btrfs_item_ptr(leaf, path->slots[0],
2373 struct btrfs_file_extent_item);
2374 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2376 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2377 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2378 btrfs_set_file_extent_offset(leaf, fi, 0);
2379 btrfs_mark_buffer_dirty(leaf);
2382 btrfs_release_path(path);
2384 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode),
2385 offset, 0, 0, end - offset, 0, end - offset, 0, 0, 0);
2390 btrfs_release_path(path);
2392 hole_em = alloc_extent_map();
2394 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2395 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
2397 hole_em->start = offset;
2398 hole_em->len = end - offset;
2399 hole_em->ram_bytes = hole_em->len;
2400 hole_em->orig_start = offset;
2402 hole_em->block_start = EXTENT_MAP_HOLE;
2403 hole_em->block_len = 0;
2404 hole_em->orig_block_len = 0;
2405 hole_em->bdev = fs_info->fs_devices->latest_bdev;
2406 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2407 hole_em->generation = trans->transid;
2410 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2411 write_lock(&em_tree->lock);
2412 ret = add_extent_mapping(em_tree, hole_em, 1);
2413 write_unlock(&em_tree->lock);
2414 } while (ret == -EEXIST);
2415 free_extent_map(hole_em);
2417 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2418 &inode->runtime_flags);
2425 * Find a hole extent on given inode and change start/len to the end of hole
2426 * extent.(hole/vacuum extent whose em->start <= start &&
2427 * em->start + em->len > start)
2428 * When a hole extent is found, return 1 and modify start/len.
2430 static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)
2432 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2433 struct extent_map *em;
2436 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2437 round_down(*start, fs_info->sectorsize),
2438 round_up(*len, fs_info->sectorsize), 0);
2442 /* Hole or vacuum extent(only exists in no-hole mode) */
2443 if (em->block_start == EXTENT_MAP_HOLE) {
2445 *len = em->start + em->len > *start + *len ?
2446 0 : *start + *len - em->start - em->len;
2447 *start = em->start + em->len;
2449 free_extent_map(em);
2453 static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2455 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2456 struct btrfs_root *root = BTRFS_I(inode)->root;
2457 struct extent_state *cached_state = NULL;
2458 struct btrfs_path *path;
2459 struct btrfs_block_rsv *rsv;
2460 struct btrfs_trans_handle *trans;
2465 u64 orig_start = offset;
2467 u64 min_size = btrfs_calc_trans_metadata_size(fs_info, 1);
2471 unsigned int rsv_count;
2473 bool no_holes = btrfs_fs_incompat(fs_info, NO_HOLES);
2475 bool truncated_block = false;
2476 bool updated_inode = false;
2478 ret = btrfs_wait_ordered_range(inode, offset, len);
2483 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2484 ret = find_first_non_hole(inode, &offset, &len);
2486 goto out_only_mutex;
2488 /* Already in a large hole */
2490 goto out_only_mutex;
2493 lockstart = round_up(offset, btrfs_inode_sectorsize(inode));
2494 lockend = round_down(offset + len,
2495 btrfs_inode_sectorsize(inode)) - 1;
2496 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset))
2497 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1));
2499 * We needn't truncate any block which is beyond the end of the file
2500 * because we are sure there is no data there.
2503 * Only do this if we are in the same block and we aren't doing the
2506 if (same_block && len < fs_info->sectorsize) {
2507 if (offset < ino_size) {
2508 truncated_block = true;
2509 ret = btrfs_truncate_block(inode, offset, len, 0);
2513 goto out_only_mutex;
2516 /* zero back part of the first block */
2517 if (offset < ino_size) {
2518 truncated_block = true;
2519 ret = btrfs_truncate_block(inode, offset, 0, 0);
2521 inode_unlock(inode);
2526 /* Check the aligned pages after the first unaligned page,
2527 * if offset != orig_start, which means the first unaligned page
2528 * including several following pages are already in holes,
2529 * the extra check can be skipped */
2530 if (offset == orig_start) {
2531 /* after truncate page, check hole again */
2532 len = offset + len - lockstart;
2534 ret = find_first_non_hole(inode, &offset, &len);
2536 goto out_only_mutex;
2539 goto out_only_mutex;
2544 /* Check the tail unaligned part is in a hole */
2545 tail_start = lockend + 1;
2546 tail_len = offset + len - tail_start;
2548 ret = find_first_non_hole(inode, &tail_start, &tail_len);
2549 if (unlikely(ret < 0))
2550 goto out_only_mutex;
2552 /* zero the front end of the last page */
2553 if (tail_start + tail_len < ino_size) {
2554 truncated_block = true;
2555 ret = btrfs_truncate_block(inode,
2556 tail_start + tail_len,
2559 goto out_only_mutex;
2564 if (lockend < lockstart) {
2566 goto out_only_mutex;
2570 struct btrfs_ordered_extent *ordered;
2572 truncate_pagecache_range(inode, lockstart, lockend);
2574 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2576 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2579 * We need to make sure we have no ordered extents in this range
2580 * and nobody raced in and read a page in this range, if we did
2581 * we need to try again.
2584 (ordered->file_offset + ordered->len <= lockstart ||
2585 ordered->file_offset > lockend)) &&
2586 !btrfs_page_exists_in_range(inode, lockstart, lockend)) {
2588 btrfs_put_ordered_extent(ordered);
2592 btrfs_put_ordered_extent(ordered);
2593 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2594 lockend, &cached_state, GFP_NOFS);
2595 ret = btrfs_wait_ordered_range(inode, lockstart,
2596 lockend - lockstart + 1);
2598 inode_unlock(inode);
2603 path = btrfs_alloc_path();
2609 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
2614 rsv->size = btrfs_calc_trans_metadata_size(fs_info, 1);
2618 * 1 - update the inode
2619 * 1 - removing the extents in the range
2620 * 1 - adding the hole extent if no_holes isn't set
2622 rsv_count = no_holes ? 2 : 3;
2623 trans = btrfs_start_transaction(root, rsv_count);
2624 if (IS_ERR(trans)) {
2625 err = PTR_ERR(trans);
2629 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
2632 trans->block_rsv = rsv;
2634 cur_offset = lockstart;
2635 len = lockend - cur_offset;
2636 while (cur_offset < lockend) {
2637 ret = __btrfs_drop_extents(trans, root, inode, path,
2638 cur_offset, lockend + 1,
2639 &drop_end, 1, 0, 0, NULL);
2643 trans->block_rsv = &fs_info->trans_block_rsv;
2645 if (cur_offset < drop_end && cur_offset < ino_size) {
2646 ret = fill_holes(trans, BTRFS_I(inode), path,
2647 cur_offset, drop_end);
2650 * If we failed then we didn't insert our hole
2651 * entries for the area we dropped, so now the
2652 * fs is corrupted, so we must abort the
2655 btrfs_abort_transaction(trans, ret);
2661 cur_offset = drop_end;
2663 ret = btrfs_update_inode(trans, root, inode);
2669 btrfs_end_transaction(trans);
2670 btrfs_btree_balance_dirty(fs_info);
2672 trans = btrfs_start_transaction(root, rsv_count);
2673 if (IS_ERR(trans)) {
2674 ret = PTR_ERR(trans);
2679 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
2681 BUG_ON(ret); /* shouldn't happen */
2682 trans->block_rsv = rsv;
2684 ret = find_first_non_hole(inode, &cur_offset, &len);
2685 if (unlikely(ret < 0))
2698 trans->block_rsv = &fs_info->trans_block_rsv;
2700 * If we are using the NO_HOLES feature we might have had already an
2701 * hole that overlaps a part of the region [lockstart, lockend] and
2702 * ends at (or beyond) lockend. Since we have no file extent items to
2703 * represent holes, drop_end can be less than lockend and so we must
2704 * make sure we have an extent map representing the existing hole (the
2705 * call to __btrfs_drop_extents() might have dropped the existing extent
2706 * map representing the existing hole), otherwise the fast fsync path
2707 * will not record the existence of the hole region
2708 * [existing_hole_start, lockend].
2710 if (drop_end <= lockend)
2711 drop_end = lockend + 1;
2713 * Don't insert file hole extent item if it's for a range beyond eof
2714 * (because it's useless) or if it represents a 0 bytes range (when
2715 * cur_offset == drop_end).
2717 if (cur_offset < ino_size && cur_offset < drop_end) {
2718 ret = fill_holes(trans, BTRFS_I(inode), path,
2719 cur_offset, drop_end);
2721 /* Same comment as above. */
2722 btrfs_abort_transaction(trans, ret);
2732 inode_inc_iversion(inode);
2733 inode->i_mtime = inode->i_ctime = current_time(inode);
2735 trans->block_rsv = &fs_info->trans_block_rsv;
2736 ret = btrfs_update_inode(trans, root, inode);
2737 updated_inode = true;
2738 btrfs_end_transaction(trans);
2739 btrfs_btree_balance_dirty(fs_info);
2741 btrfs_free_path(path);
2742 btrfs_free_block_rsv(fs_info, rsv);
2744 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2745 &cached_state, GFP_NOFS);
2747 if (!updated_inode && truncated_block && !ret && !err) {
2749 * If we only end up zeroing part of a page, we still need to
2750 * update the inode item, so that all the time fields are
2751 * updated as well as the necessary btrfs inode in memory fields
2752 * for detecting, at fsync time, if the inode isn't yet in the
2753 * log tree or it's there but not up to date.
2755 trans = btrfs_start_transaction(root, 1);
2756 if (IS_ERR(trans)) {
2757 err = PTR_ERR(trans);
2759 err = btrfs_update_inode(trans, root, inode);
2760 ret = btrfs_end_transaction(trans);
2763 inode_unlock(inode);
2769 /* Helper structure to record which range is already reserved */
2770 struct falloc_range {
2771 struct list_head list;
2777 * Helper function to add falloc range
2779 * Caller should have locked the larger range of extent containing
2782 static int add_falloc_range(struct list_head *head, u64 start, u64 len)
2784 struct falloc_range *prev = NULL;
2785 struct falloc_range *range = NULL;
2787 if (list_empty(head))
2791 * As fallocate iterate by bytenr order, we only need to check
2794 prev = list_entry(head->prev, struct falloc_range, list);
2795 if (prev->start + prev->len == start) {
2800 range = kmalloc(sizeof(*range), GFP_KERNEL);
2803 range->start = start;
2805 list_add_tail(&range->list, head);
2809 static long btrfs_fallocate(struct file *file, int mode,
2810 loff_t offset, loff_t len)
2812 struct inode *inode = file_inode(file);
2813 struct extent_state *cached_state = NULL;
2814 struct extent_changeset *data_reserved = NULL;
2815 struct falloc_range *range;
2816 struct falloc_range *tmp;
2817 struct list_head reserve_list;
2825 struct extent_map *em;
2826 int blocksize = btrfs_inode_sectorsize(inode);
2829 alloc_start = round_down(offset, blocksize);
2830 alloc_end = round_up(offset + len, blocksize);
2831 cur_offset = alloc_start;
2833 /* Make sure we aren't being give some crap mode */
2834 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
2837 if (mode & FALLOC_FL_PUNCH_HOLE)
2838 return btrfs_punch_hole(inode, offset, len);
2841 * Only trigger disk allocation, don't trigger qgroup reserve
2843 * For qgroup space, it will be checked later.
2845 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
2846 alloc_end - alloc_start);
2852 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
2853 ret = inode_newsize_ok(inode, offset + len);
2859 * TODO: Move these two operations after we have checked
2860 * accurate reserved space, or fallocate can still fail but
2861 * with page truncated or size expanded.
2863 * But that's a minor problem and won't do much harm BTW.
2865 if (alloc_start > inode->i_size) {
2866 ret = btrfs_cont_expand(inode, i_size_read(inode),
2870 } else if (offset + len > inode->i_size) {
2872 * If we are fallocating from the end of the file onward we
2873 * need to zero out the end of the block if i_size lands in the
2874 * middle of a block.
2876 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
2882 * wait for ordered IO before we have any locks. We'll loop again
2883 * below with the locks held.
2885 ret = btrfs_wait_ordered_range(inode, alloc_start,
2886 alloc_end - alloc_start);
2890 locked_end = alloc_end - 1;
2892 struct btrfs_ordered_extent *ordered;
2894 /* the extent lock is ordered inside the running
2897 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
2898 locked_end, &cached_state);
2899 ordered = btrfs_lookup_first_ordered_extent(inode,
2902 ordered->file_offset + ordered->len > alloc_start &&
2903 ordered->file_offset < alloc_end) {
2904 btrfs_put_ordered_extent(ordered);
2905 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
2906 alloc_start, locked_end,
2907 &cached_state, GFP_KERNEL);
2909 * we can't wait on the range with the transaction
2910 * running or with the extent lock held
2912 ret = btrfs_wait_ordered_range(inode, alloc_start,
2913 alloc_end - alloc_start);
2918 btrfs_put_ordered_extent(ordered);
2923 /* First, check if we exceed the qgroup limit */
2924 INIT_LIST_HEAD(&reserve_list);
2926 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
2927 alloc_end - cur_offset, 0);
2932 last_byte = min(extent_map_end(em), alloc_end);
2933 actual_end = min_t(u64, extent_map_end(em), offset + len);
2934 last_byte = ALIGN(last_byte, blocksize);
2935 if (em->block_start == EXTENT_MAP_HOLE ||
2936 (cur_offset >= inode->i_size &&
2937 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
2938 ret = add_falloc_range(&reserve_list, cur_offset,
2939 last_byte - cur_offset);
2941 free_extent_map(em);
2944 ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
2945 cur_offset, last_byte - cur_offset);
2947 free_extent_map(em);
2952 * Do not need to reserve unwritten extent for this
2953 * range, free reserved data space first, otherwise
2954 * it'll result in false ENOSPC error.
2956 btrfs_free_reserved_data_space(inode, data_reserved,
2957 cur_offset, last_byte - cur_offset);
2959 free_extent_map(em);
2960 cur_offset = last_byte;
2961 if (cur_offset >= alloc_end)
2966 * If ret is still 0, means we're OK to fallocate.
2967 * Or just cleanup the list and exit.
2969 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
2971 ret = btrfs_prealloc_file_range(inode, mode,
2973 range->len, i_blocksize(inode),
2974 offset + len, &alloc_hint);
2976 btrfs_free_reserved_data_space(inode,
2977 data_reserved, range->start,
2979 list_del(&range->list);
2985 if (actual_end > inode->i_size &&
2986 !(mode & FALLOC_FL_KEEP_SIZE)) {
2987 struct btrfs_trans_handle *trans;
2988 struct btrfs_root *root = BTRFS_I(inode)->root;
2991 * We didn't need to allocate any more space, but we
2992 * still extended the size of the file so we need to
2993 * update i_size and the inode item.
2995 trans = btrfs_start_transaction(root, 1);
2996 if (IS_ERR(trans)) {
2997 ret = PTR_ERR(trans);
2999 inode->i_ctime = current_time(inode);
3000 i_size_write(inode, actual_end);
3001 btrfs_ordered_update_i_size(inode, actual_end, NULL);
3002 ret = btrfs_update_inode(trans, root, inode);
3004 btrfs_end_transaction(trans);
3006 ret = btrfs_end_transaction(trans);
3010 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
3011 &cached_state, GFP_KERNEL);
3013 inode_unlock(inode);
3014 /* Let go of our reservation. */
3016 btrfs_free_reserved_data_space(inode, data_reserved,
3017 alloc_start, alloc_end - cur_offset);
3018 extent_changeset_free(data_reserved);
3022 static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
3024 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3025 struct extent_map *em = NULL;
3026 struct extent_state *cached_state = NULL;
3033 if (inode->i_size == 0)
3037 * *offset can be negative, in this case we start finding DATA/HOLE from
3038 * the very start of the file.
3040 start = max_t(loff_t, 0, *offset);
3042 lockstart = round_down(start, fs_info->sectorsize);
3043 lockend = round_up(i_size_read(inode),
3044 fs_info->sectorsize);
3045 if (lockend <= lockstart)
3046 lockend = lockstart + fs_info->sectorsize;
3048 len = lockend - lockstart + 1;
3050 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3053 while (start < inode->i_size) {
3054 em = btrfs_get_extent_fiemap(BTRFS_I(inode), NULL, 0,
3062 if (whence == SEEK_HOLE &&
3063 (em->block_start == EXTENT_MAP_HOLE ||
3064 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3066 else if (whence == SEEK_DATA &&
3067 (em->block_start != EXTENT_MAP_HOLE &&
3068 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3071 start = em->start + em->len;
3072 free_extent_map(em);
3076 free_extent_map(em);
3078 if (whence == SEEK_DATA && start >= inode->i_size)
3081 *offset = min_t(loff_t, start, inode->i_size);
3083 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3084 &cached_state, GFP_NOFS);
3088 static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
3090 struct inode *inode = file->f_mapping->host;
3097 offset = generic_file_llseek(file, offset, whence);
3101 if (offset >= i_size_read(inode)) {
3102 inode_unlock(inode);
3106 ret = find_desired_extent(inode, &offset, whence);
3108 inode_unlock(inode);
3113 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
3115 inode_unlock(inode);
3119 static int btrfs_file_open(struct inode *inode, struct file *filp)
3121 filp->f_mode |= FMODE_NOWAIT;
3122 return generic_file_open(inode, filp);
3125 const struct file_operations btrfs_file_operations = {
3126 .llseek = btrfs_file_llseek,
3127 .read_iter = generic_file_read_iter,
3128 .splice_read = generic_file_splice_read,
3129 .write_iter = btrfs_file_write_iter,
3130 .mmap = btrfs_file_mmap,
3131 .open = btrfs_file_open,
3132 .release = btrfs_release_file,
3133 .fsync = btrfs_sync_file,
3134 .fallocate = btrfs_fallocate,
3135 .unlocked_ioctl = btrfs_ioctl,
3136 #ifdef CONFIG_COMPAT
3137 .compat_ioctl = btrfs_compat_ioctl,
3139 .clone_file_range = btrfs_clone_file_range,
3140 .dedupe_file_range = btrfs_dedupe_file_range,
3143 void btrfs_auto_defrag_exit(void)
3145 kmem_cache_destroy(btrfs_inode_defrag_cachep);
3148 int btrfs_auto_defrag_init(void)
3150 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
3151 sizeof(struct inode_defrag), 0,
3154 if (!btrfs_inode_defrag_cachep)
3160 int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
3165 * So with compression we will find and lock a dirty page and clear the
3166 * first one as dirty, setup an async extent, and immediately return
3167 * with the entire range locked but with nobody actually marked with
3168 * writeback. So we can't just filemap_write_and_wait_range() and
3169 * expect it to work since it will just kick off a thread to do the
3170 * actual work. So we need to call filemap_fdatawrite_range _again_
3171 * since it will wait on the page lock, which won't be unlocked until
3172 * after the pages have been marked as writeback and so we're good to go
3173 * from there. We have to do this otherwise we'll miss the ordered
3174 * extents and that results in badness. Please Josef, do not think you
3175 * know better and pull this out at some point in the future, it is
3176 * right and you are wrong.
3178 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3179 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
3180 &BTRFS_I(inode)->runtime_flags))
3181 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);