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]);
481 * after copy_from_user, pages need to be dirtied and we need to make
482 * sure holes are created between the current EOF and the start of
483 * any next extents (if required).
485 * this also makes the decision about creating an inline extent vs
486 * doing real data extents, marking pages dirty and delalloc as required.
488 int btrfs_dirty_pages(struct inode *inode, struct page **pages,
489 size_t num_pages, loff_t pos, size_t write_bytes,
490 struct extent_state **cached)
492 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
497 u64 end_of_last_block;
498 u64 end_pos = pos + write_bytes;
499 loff_t isize = i_size_read(inode);
501 start_pos = pos & ~((u64) fs_info->sectorsize - 1);
502 num_bytes = round_up(write_bytes + pos - start_pos,
503 fs_info->sectorsize);
505 end_of_last_block = start_pos + num_bytes - 1;
506 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
511 for (i = 0; i < num_pages; i++) {
512 struct page *p = pages[i];
519 * we've only changed i_size in ram, and we haven't updated
520 * the disk i_size. There is no need to log the inode
524 i_size_write(inode, end_pos);
529 * this drops all the extents in the cache that intersect the range
530 * [start, end]. Existing extents are split as required.
532 void btrfs_drop_extent_cache(struct btrfs_inode *inode, u64 start, u64 end,
535 struct extent_map *em;
536 struct extent_map *split = NULL;
537 struct extent_map *split2 = NULL;
538 struct extent_map_tree *em_tree = &inode->extent_tree;
539 u64 len = end - start + 1;
547 WARN_ON(end < start);
548 if (end == (u64)-1) {
557 split = alloc_extent_map();
559 split2 = alloc_extent_map();
560 if (!split || !split2)
563 write_lock(&em_tree->lock);
564 em = lookup_extent_mapping(em_tree, start, len);
566 write_unlock(&em_tree->lock);
570 gen = em->generation;
571 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
572 if (testend && em->start + em->len >= start + len) {
574 write_unlock(&em_tree->lock);
577 start = em->start + em->len;
579 len = start + len - (em->start + em->len);
581 write_unlock(&em_tree->lock);
584 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
585 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
586 clear_bit(EXTENT_FLAG_LOGGING, &flags);
587 modified = !list_empty(&em->list);
591 if (em->start < start) {
592 split->start = em->start;
593 split->len = start - em->start;
595 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
596 split->orig_start = em->orig_start;
597 split->block_start = em->block_start;
600 split->block_len = em->block_len;
602 split->block_len = split->len;
603 split->orig_block_len = max(split->block_len,
605 split->ram_bytes = em->ram_bytes;
607 split->orig_start = split->start;
608 split->block_len = 0;
609 split->block_start = em->block_start;
610 split->orig_block_len = 0;
611 split->ram_bytes = split->len;
614 split->generation = gen;
615 split->bdev = em->bdev;
616 split->flags = flags;
617 split->compress_type = em->compress_type;
618 replace_extent_mapping(em_tree, em, split, modified);
619 free_extent_map(split);
623 if (testend && em->start + em->len > start + len) {
624 u64 diff = start + len - em->start;
626 split->start = start + len;
627 split->len = em->start + em->len - (start + len);
628 split->bdev = em->bdev;
629 split->flags = flags;
630 split->compress_type = em->compress_type;
631 split->generation = gen;
633 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
634 split->orig_block_len = max(em->block_len,
637 split->ram_bytes = em->ram_bytes;
639 split->block_len = em->block_len;
640 split->block_start = em->block_start;
641 split->orig_start = em->orig_start;
643 split->block_len = split->len;
644 split->block_start = em->block_start
646 split->orig_start = em->orig_start;
649 split->ram_bytes = split->len;
650 split->orig_start = split->start;
651 split->block_len = 0;
652 split->block_start = em->block_start;
653 split->orig_block_len = 0;
656 if (extent_map_in_tree(em)) {
657 replace_extent_mapping(em_tree, em, split,
660 ret = add_extent_mapping(em_tree, split,
662 ASSERT(ret == 0); /* Logic error */
664 free_extent_map(split);
668 if (extent_map_in_tree(em))
669 remove_extent_mapping(em_tree, em);
670 write_unlock(&em_tree->lock);
674 /* once for the tree*/
678 free_extent_map(split);
680 free_extent_map(split2);
684 * this is very complex, but the basic idea is to drop all extents
685 * in the range start - end. hint_block is filled in with a block number
686 * that would be a good hint to the block allocator for this file.
688 * If an extent intersects the range but is not entirely inside the range
689 * it is either truncated or split. Anything entirely inside the range
690 * is deleted from the tree.
692 int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
693 struct btrfs_root *root, struct inode *inode,
694 struct btrfs_path *path, u64 start, u64 end,
695 u64 *drop_end, int drop_cache,
697 u32 extent_item_size,
700 struct btrfs_fs_info *fs_info = root->fs_info;
701 struct extent_buffer *leaf;
702 struct btrfs_file_extent_item *fi;
703 struct btrfs_key key;
704 struct btrfs_key new_key;
705 u64 ino = btrfs_ino(BTRFS_I(inode));
706 u64 search_start = start;
709 u64 extent_offset = 0;
711 u64 last_end = start;
717 int modify_tree = -1;
720 int leafs_visited = 0;
723 btrfs_drop_extent_cache(BTRFS_I(inode), start, end - 1, 0);
725 if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent)
728 update_refs = (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
729 root == fs_info->tree_root);
732 ret = btrfs_lookup_file_extent(trans, root, path, ino,
733 search_start, modify_tree);
736 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
737 leaf = path->nodes[0];
738 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
739 if (key.objectid == ino &&
740 key.type == BTRFS_EXTENT_DATA_KEY)
746 leaf = path->nodes[0];
747 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
749 ret = btrfs_next_leaf(root, path);
757 leaf = path->nodes[0];
761 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
763 if (key.objectid > ino)
765 if (WARN_ON_ONCE(key.objectid < ino) ||
766 key.type < BTRFS_EXTENT_DATA_KEY) {
771 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
774 fi = btrfs_item_ptr(leaf, path->slots[0],
775 struct btrfs_file_extent_item);
776 extent_type = btrfs_file_extent_type(leaf, fi);
778 if (extent_type == BTRFS_FILE_EXTENT_REG ||
779 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
780 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
781 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
782 extent_offset = btrfs_file_extent_offset(leaf, fi);
783 extent_end = key.offset +
784 btrfs_file_extent_num_bytes(leaf, fi);
785 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
786 extent_end = key.offset +
787 btrfs_file_extent_inline_len(leaf,
795 * Don't skip extent items representing 0 byte lengths. They
796 * used to be created (bug) if while punching holes we hit
797 * -ENOSPC condition. So if we find one here, just ensure we
798 * delete it, otherwise we would insert a new file extent item
799 * with the same key (offset) as that 0 bytes length file
800 * extent item in the call to setup_items_for_insert() later
803 if (extent_end == key.offset && extent_end >= search_start) {
804 last_end = extent_end;
805 goto delete_extent_item;
808 if (extent_end <= search_start) {
814 search_start = max(key.offset, start);
815 if (recow || !modify_tree) {
817 btrfs_release_path(path);
822 * | - range to drop - |
823 * | -------- extent -------- |
825 if (start > key.offset && end < extent_end) {
827 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
832 memcpy(&new_key, &key, sizeof(new_key));
833 new_key.offset = start;
834 ret = btrfs_duplicate_item(trans, root, path,
836 if (ret == -EAGAIN) {
837 btrfs_release_path(path);
843 leaf = path->nodes[0];
844 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
845 struct btrfs_file_extent_item);
846 btrfs_set_file_extent_num_bytes(leaf, fi,
849 fi = btrfs_item_ptr(leaf, path->slots[0],
850 struct btrfs_file_extent_item);
852 extent_offset += start - key.offset;
853 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
854 btrfs_set_file_extent_num_bytes(leaf, fi,
856 btrfs_mark_buffer_dirty(leaf);
858 if (update_refs && disk_bytenr > 0) {
859 ret = btrfs_inc_extent_ref(trans, fs_info,
860 disk_bytenr, num_bytes, 0,
861 root->root_key.objectid,
863 start - extent_offset);
864 BUG_ON(ret); /* -ENOMEM */
869 * From here on out we will have actually dropped something, so
870 * last_end can be updated.
872 last_end = extent_end;
875 * | ---- range to drop ----- |
876 * | -------- extent -------- |
878 if (start <= key.offset && end < extent_end) {
879 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
884 memcpy(&new_key, &key, sizeof(new_key));
885 new_key.offset = end;
886 btrfs_set_item_key_safe(fs_info, path, &new_key);
888 extent_offset += end - key.offset;
889 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
890 btrfs_set_file_extent_num_bytes(leaf, fi,
892 btrfs_mark_buffer_dirty(leaf);
893 if (update_refs && disk_bytenr > 0)
894 inode_sub_bytes(inode, end - key.offset);
898 search_start = extent_end;
900 * | ---- range to drop ----- |
901 * | -------- extent -------- |
903 if (start > key.offset && end >= extent_end) {
905 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
910 btrfs_set_file_extent_num_bytes(leaf, fi,
912 btrfs_mark_buffer_dirty(leaf);
913 if (update_refs && disk_bytenr > 0)
914 inode_sub_bytes(inode, extent_end - start);
915 if (end == extent_end)
923 * | ---- range to drop ----- |
924 * | ------ extent ------ |
926 if (start <= key.offset && end >= extent_end) {
929 del_slot = path->slots[0];
932 BUG_ON(del_slot + del_nr != path->slots[0]);
937 extent_type == BTRFS_FILE_EXTENT_INLINE) {
938 inode_sub_bytes(inode,
939 extent_end - key.offset);
940 extent_end = ALIGN(extent_end,
941 fs_info->sectorsize);
942 } else if (update_refs && disk_bytenr > 0) {
943 ret = btrfs_free_extent(trans, fs_info,
944 disk_bytenr, num_bytes, 0,
945 root->root_key.objectid,
946 key.objectid, key.offset -
948 BUG_ON(ret); /* -ENOMEM */
949 inode_sub_bytes(inode,
950 extent_end - key.offset);
953 if (end == extent_end)
956 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
961 ret = btrfs_del_items(trans, root, path, del_slot,
964 btrfs_abort_transaction(trans, ret);
971 btrfs_release_path(path);
978 if (!ret && del_nr > 0) {
980 * Set path->slots[0] to first slot, so that after the delete
981 * if items are move off from our leaf to its immediate left or
982 * right neighbor leafs, we end up with a correct and adjusted
983 * path->slots[0] for our insertion (if replace_extent != 0).
985 path->slots[0] = del_slot;
986 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
988 btrfs_abort_transaction(trans, ret);
991 leaf = path->nodes[0];
993 * If btrfs_del_items() was called, it might have deleted a leaf, in
994 * which case it unlocked our path, so check path->locks[0] matches a
997 if (!ret && replace_extent && leafs_visited == 1 &&
998 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
999 path->locks[0] == BTRFS_WRITE_LOCK) &&
1000 btrfs_leaf_free_space(fs_info, leaf) >=
1001 sizeof(struct btrfs_item) + extent_item_size) {
1004 key.type = BTRFS_EXTENT_DATA_KEY;
1006 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
1007 struct btrfs_key slot_key;
1009 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
1010 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
1013 setup_items_for_insert(root, path, &key,
1016 sizeof(struct btrfs_item) +
1017 extent_item_size, 1);
1021 if (!replace_extent || !(*key_inserted))
1022 btrfs_release_path(path);
1024 *drop_end = found ? min(end, last_end) : end;
1028 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
1029 struct btrfs_root *root, struct inode *inode, u64 start,
1030 u64 end, int drop_cache)
1032 struct btrfs_path *path;
1035 path = btrfs_alloc_path();
1038 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
1039 drop_cache, 0, 0, NULL);
1040 btrfs_free_path(path);
1044 static int extent_mergeable(struct extent_buffer *leaf, int slot,
1045 u64 objectid, u64 bytenr, u64 orig_offset,
1046 u64 *start, u64 *end)
1048 struct btrfs_file_extent_item *fi;
1049 struct btrfs_key key;
1052 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1055 btrfs_item_key_to_cpu(leaf, &key, slot);
1056 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1059 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1060 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1061 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1062 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1063 btrfs_file_extent_compression(leaf, fi) ||
1064 btrfs_file_extent_encryption(leaf, fi) ||
1065 btrfs_file_extent_other_encoding(leaf, fi))
1068 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1069 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1072 *start = key.offset;
1078 * Mark extent in the range start - end as written.
1080 * This changes extent type from 'pre-allocated' to 'regular'. If only
1081 * part of extent is marked as written, the extent will be split into
1084 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1085 struct btrfs_inode *inode, u64 start, u64 end)
1087 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1088 struct btrfs_root *root = inode->root;
1089 struct extent_buffer *leaf;
1090 struct btrfs_path *path;
1091 struct btrfs_file_extent_item *fi;
1092 struct btrfs_key key;
1093 struct btrfs_key new_key;
1105 u64 ino = btrfs_ino(inode);
1107 path = btrfs_alloc_path();
1114 key.type = BTRFS_EXTENT_DATA_KEY;
1117 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1120 if (ret > 0 && path->slots[0] > 0)
1123 leaf = path->nodes[0];
1124 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1125 if (key.objectid != ino ||
1126 key.type != BTRFS_EXTENT_DATA_KEY) {
1128 btrfs_abort_transaction(trans, ret);
1131 fi = btrfs_item_ptr(leaf, path->slots[0],
1132 struct btrfs_file_extent_item);
1133 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) {
1135 btrfs_abort_transaction(trans, ret);
1138 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1139 if (key.offset > start || extent_end < end) {
1141 btrfs_abort_transaction(trans, ret);
1145 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1146 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1147 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1148 memcpy(&new_key, &key, sizeof(new_key));
1150 if (start == key.offset && end < extent_end) {
1153 if (extent_mergeable(leaf, path->slots[0] - 1,
1154 ino, bytenr, orig_offset,
1155 &other_start, &other_end)) {
1156 new_key.offset = end;
1157 btrfs_set_item_key_safe(fs_info, path, &new_key);
1158 fi = btrfs_item_ptr(leaf, path->slots[0],
1159 struct btrfs_file_extent_item);
1160 btrfs_set_file_extent_generation(leaf, fi,
1162 btrfs_set_file_extent_num_bytes(leaf, fi,
1164 btrfs_set_file_extent_offset(leaf, fi,
1166 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1167 struct btrfs_file_extent_item);
1168 btrfs_set_file_extent_generation(leaf, fi,
1170 btrfs_set_file_extent_num_bytes(leaf, fi,
1172 btrfs_mark_buffer_dirty(leaf);
1177 if (start > key.offset && end == extent_end) {
1180 if (extent_mergeable(leaf, path->slots[0] + 1,
1181 ino, bytenr, orig_offset,
1182 &other_start, &other_end)) {
1183 fi = btrfs_item_ptr(leaf, path->slots[0],
1184 struct btrfs_file_extent_item);
1185 btrfs_set_file_extent_num_bytes(leaf, fi,
1186 start - key.offset);
1187 btrfs_set_file_extent_generation(leaf, fi,
1190 new_key.offset = start;
1191 btrfs_set_item_key_safe(fs_info, path, &new_key);
1193 fi = btrfs_item_ptr(leaf, path->slots[0],
1194 struct btrfs_file_extent_item);
1195 btrfs_set_file_extent_generation(leaf, fi,
1197 btrfs_set_file_extent_num_bytes(leaf, fi,
1199 btrfs_set_file_extent_offset(leaf, fi,
1200 start - orig_offset);
1201 btrfs_mark_buffer_dirty(leaf);
1206 while (start > key.offset || end < extent_end) {
1207 if (key.offset == start)
1210 new_key.offset = split;
1211 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1212 if (ret == -EAGAIN) {
1213 btrfs_release_path(path);
1217 btrfs_abort_transaction(trans, ret);
1221 leaf = path->nodes[0];
1222 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1223 struct btrfs_file_extent_item);
1224 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1225 btrfs_set_file_extent_num_bytes(leaf, fi,
1226 split - key.offset);
1228 fi = btrfs_item_ptr(leaf, path->slots[0],
1229 struct btrfs_file_extent_item);
1231 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1232 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1233 btrfs_set_file_extent_num_bytes(leaf, fi,
1234 extent_end - split);
1235 btrfs_mark_buffer_dirty(leaf);
1237 ret = btrfs_inc_extent_ref(trans, fs_info, bytenr, num_bytes,
1238 0, root->root_key.objectid,
1241 btrfs_abort_transaction(trans, ret);
1245 if (split == start) {
1248 if (start != key.offset) {
1250 btrfs_abort_transaction(trans, ret);
1261 if (extent_mergeable(leaf, path->slots[0] + 1,
1262 ino, bytenr, orig_offset,
1263 &other_start, &other_end)) {
1265 btrfs_release_path(path);
1268 extent_end = other_end;
1269 del_slot = path->slots[0] + 1;
1271 ret = btrfs_free_extent(trans, fs_info, bytenr, num_bytes,
1272 0, root->root_key.objectid,
1275 btrfs_abort_transaction(trans, ret);
1281 if (extent_mergeable(leaf, path->slots[0] - 1,
1282 ino, bytenr, orig_offset,
1283 &other_start, &other_end)) {
1285 btrfs_release_path(path);
1288 key.offset = other_start;
1289 del_slot = path->slots[0];
1291 ret = btrfs_free_extent(trans, fs_info, bytenr, num_bytes,
1292 0, root->root_key.objectid,
1295 btrfs_abort_transaction(trans, ret);
1300 fi = btrfs_item_ptr(leaf, path->slots[0],
1301 struct btrfs_file_extent_item);
1302 btrfs_set_file_extent_type(leaf, fi,
1303 BTRFS_FILE_EXTENT_REG);
1304 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1305 btrfs_mark_buffer_dirty(leaf);
1307 fi = btrfs_item_ptr(leaf, del_slot - 1,
1308 struct btrfs_file_extent_item);
1309 btrfs_set_file_extent_type(leaf, fi,
1310 BTRFS_FILE_EXTENT_REG);
1311 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1312 btrfs_set_file_extent_num_bytes(leaf, fi,
1313 extent_end - key.offset);
1314 btrfs_mark_buffer_dirty(leaf);
1316 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1318 btrfs_abort_transaction(trans, ret);
1323 btrfs_free_path(path);
1328 * on error we return an unlocked page and the error value
1329 * on success we return a locked page and 0
1331 static int prepare_uptodate_page(struct inode *inode,
1332 struct page *page, u64 pos,
1333 bool force_uptodate)
1337 if (((pos & (PAGE_SIZE - 1)) || force_uptodate) &&
1338 !PageUptodate(page)) {
1339 ret = btrfs_readpage(NULL, page);
1343 if (!PageUptodate(page)) {
1347 if (page->mapping != inode->i_mapping) {
1356 * this just gets pages into the page cache and locks them down.
1358 static noinline int prepare_pages(struct inode *inode, struct page **pages,
1359 size_t num_pages, loff_t pos,
1360 size_t write_bytes, bool force_uptodate)
1363 unsigned long index = pos >> PAGE_SHIFT;
1364 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1368 for (i = 0; i < num_pages; i++) {
1370 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1371 mask | __GFP_WRITE);
1379 err = prepare_uptodate_page(inode, pages[i], pos,
1381 if (!err && i == num_pages - 1)
1382 err = prepare_uptodate_page(inode, pages[i],
1383 pos + write_bytes, false);
1386 if (err == -EAGAIN) {
1393 wait_on_page_writeback(pages[i]);
1398 while (faili >= 0) {
1399 unlock_page(pages[faili]);
1400 put_page(pages[faili]);
1407 static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
1410 struct extent_state **cached_state)
1412 u64 search_start = start;
1413 const u64 end = start + len - 1;
1415 while (search_start < end) {
1416 const u64 search_len = end - search_start + 1;
1417 struct extent_map *em;
1421 em = btrfs_get_extent(inode, NULL, 0, search_start,
1426 if (em->block_start != EXTENT_MAP_HOLE)
1430 if (em->start < search_start)
1431 em_len -= search_start - em->start;
1432 if (em_len > search_len)
1433 em_len = search_len;
1435 ret = set_extent_bit(&inode->io_tree, search_start,
1436 search_start + em_len - 1,
1437 EXTENT_DELALLOC_NEW,
1438 NULL, cached_state, GFP_NOFS);
1440 search_start = extent_map_end(em);
1441 free_extent_map(em);
1449 * This function locks the extent and properly waits for data=ordered extents
1450 * to finish before allowing the pages to be modified if need.
1453 * 1 - the extent is locked
1454 * 0 - the extent is not locked, and everything is OK
1455 * -EAGAIN - need re-prepare the pages
1456 * the other < 0 number - Something wrong happens
1459 lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
1460 size_t num_pages, loff_t pos,
1462 u64 *lockstart, u64 *lockend,
1463 struct extent_state **cached_state)
1465 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1471 start_pos = round_down(pos, fs_info->sectorsize);
1472 last_pos = start_pos
1473 + round_up(pos + write_bytes - start_pos,
1474 fs_info->sectorsize) - 1;
1476 if (start_pos < inode->vfs_inode.i_size ||
1477 (inode->flags & BTRFS_INODE_PREALLOC)) {
1478 struct btrfs_ordered_extent *ordered;
1479 unsigned int clear_bits;
1481 lock_extent_bits(&inode->io_tree, start_pos, last_pos,
1483 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1484 last_pos - start_pos + 1);
1486 ordered->file_offset + ordered->len > start_pos &&
1487 ordered->file_offset <= last_pos) {
1488 unlock_extent_cached(&inode->io_tree, start_pos,
1489 last_pos, cached_state, GFP_NOFS);
1490 for (i = 0; i < num_pages; i++) {
1491 unlock_page(pages[i]);
1494 btrfs_start_ordered_extent(&inode->vfs_inode,
1496 btrfs_put_ordered_extent(ordered);
1500 btrfs_put_ordered_extent(ordered);
1501 ret = btrfs_find_new_delalloc_bytes(inode, start_pos,
1502 last_pos - start_pos + 1,
1504 clear_bits = EXTENT_DIRTY | EXTENT_DELALLOC |
1505 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG;
1507 clear_bits |= EXTENT_DELALLOC_NEW | EXTENT_LOCKED;
1508 clear_extent_bit(&inode->io_tree, start_pos,
1509 last_pos, clear_bits,
1510 (clear_bits & EXTENT_LOCKED) ? 1 : 0,
1511 0, cached_state, GFP_NOFS);
1514 *lockstart = start_pos;
1515 *lockend = last_pos;
1519 for (i = 0; i < num_pages; i++) {
1520 if (clear_page_dirty_for_io(pages[i]))
1521 account_page_redirty(pages[i]);
1522 set_page_extent_mapped(pages[i]);
1523 WARN_ON(!PageLocked(pages[i]));
1529 static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
1530 size_t *write_bytes)
1532 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
1533 struct btrfs_root *root = inode->root;
1534 struct btrfs_ordered_extent *ordered;
1535 u64 lockstart, lockend;
1539 ret = btrfs_start_write_no_snapshoting(root);
1543 lockstart = round_down(pos, fs_info->sectorsize);
1544 lockend = round_up(pos + *write_bytes,
1545 fs_info->sectorsize) - 1;
1548 lock_extent(&inode->io_tree, lockstart, lockend);
1549 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1550 lockend - lockstart + 1);
1554 unlock_extent(&inode->io_tree, lockstart, lockend);
1555 btrfs_start_ordered_extent(&inode->vfs_inode, ordered, 1);
1556 btrfs_put_ordered_extent(ordered);
1559 num_bytes = lockend - lockstart + 1;
1560 ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
1564 btrfs_end_write_no_snapshoting(root);
1566 *write_bytes = min_t(size_t, *write_bytes ,
1567 num_bytes - pos + lockstart);
1570 unlock_extent(&inode->io_tree, lockstart, lockend);
1575 static noinline ssize_t __btrfs_buffered_write(struct file *file,
1579 struct inode *inode = file_inode(file);
1580 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1581 struct btrfs_root *root = BTRFS_I(inode)->root;
1582 struct page **pages = NULL;
1583 struct extent_state *cached_state = NULL;
1584 struct extent_changeset *data_reserved = NULL;
1585 u64 release_bytes = 0;
1588 size_t num_written = 0;
1591 bool only_release_metadata = false;
1592 bool force_page_uptodate = false;
1595 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
1596 PAGE_SIZE / (sizeof(struct page *)));
1597 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1598 nrptrs = max(nrptrs, 8);
1599 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1603 while (iov_iter_count(i) > 0) {
1604 size_t offset = pos & (PAGE_SIZE - 1);
1605 size_t sector_offset;
1606 size_t write_bytes = min(iov_iter_count(i),
1607 nrptrs * (size_t)PAGE_SIZE -
1609 size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
1611 size_t reserve_bytes;
1614 size_t dirty_sectors;
1617 WARN_ON(num_pages > nrptrs);
1620 * Fault pages before locking them in prepare_pages
1621 * to avoid recursive lock
1623 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1628 sector_offset = pos & (fs_info->sectorsize - 1);
1629 reserve_bytes = round_up(write_bytes + sector_offset,
1630 fs_info->sectorsize);
1632 extent_changeset_release(data_reserved);
1633 ret = btrfs_check_data_free_space(inode, &data_reserved, pos,
1636 if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1637 BTRFS_INODE_PREALLOC)) &&
1638 check_can_nocow(BTRFS_I(inode), pos,
1639 &write_bytes) > 0) {
1641 * For nodata cow case, no need to reserve
1644 only_release_metadata = true;
1646 * our prealloc extent may be smaller than
1647 * write_bytes, so scale down.
1649 num_pages = DIV_ROUND_UP(write_bytes + offset,
1651 reserve_bytes = round_up(write_bytes +
1653 fs_info->sectorsize);
1659 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
1662 if (!only_release_metadata)
1663 btrfs_free_reserved_data_space(inode,
1667 btrfs_end_write_no_snapshoting(root);
1671 release_bytes = reserve_bytes;
1672 need_unlock = false;
1675 * This is going to setup the pages array with the number of
1676 * pages we want, so we don't really need to worry about the
1677 * contents of pages from loop to loop
1679 ret = prepare_pages(inode, pages, num_pages,
1681 force_page_uptodate);
1685 ret = lock_and_cleanup_extent_if_need(BTRFS_I(inode), pages,
1686 num_pages, pos, write_bytes, &lockstart,
1687 &lockend, &cached_state);
1692 } else if (ret > 0) {
1697 copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
1699 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes);
1700 dirty_sectors = round_up(copied + sector_offset,
1701 fs_info->sectorsize);
1702 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors);
1705 * if we have trouble faulting in the pages, fall
1706 * back to one page at a time
1708 if (copied < write_bytes)
1712 force_page_uptodate = true;
1716 force_page_uptodate = false;
1717 dirty_pages = DIV_ROUND_UP(copied + offset,
1722 * If we had a short copy we need to release the excess delaloc
1723 * bytes we reserved. We need to increment outstanding_extents
1724 * because btrfs_delalloc_release_space and
1725 * btrfs_delalloc_release_metadata will decrement it, but
1726 * we still have an outstanding extent for the chunk we actually
1729 if (num_sectors > dirty_sectors) {
1730 /* release everything except the sectors we dirtied */
1731 release_bytes -= dirty_sectors <<
1732 fs_info->sb->s_blocksize_bits;
1734 spin_lock(&BTRFS_I(inode)->lock);
1735 BTRFS_I(inode)->outstanding_extents++;
1736 spin_unlock(&BTRFS_I(inode)->lock);
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,
1764 btrfs_drop_pages(pages, num_pages);
1769 if (only_release_metadata)
1770 btrfs_end_write_no_snapshoting(root);
1772 if (only_release_metadata && copied > 0) {
1773 lockstart = round_down(pos,
1774 fs_info->sectorsize);
1775 lockend = round_up(pos + copied,
1776 fs_info->sectorsize) - 1;
1778 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1779 lockend, EXTENT_NORESERVE, NULL,
1781 only_release_metadata = false;
1784 btrfs_drop_pages(pages, num_pages);
1788 balance_dirty_pages_ratelimited(inode->i_mapping);
1789 if (dirty_pages < (fs_info->nodesize >> PAGE_SHIFT) + 1)
1790 btrfs_btree_balance_dirty(fs_info);
1793 num_written += copied;
1798 if (release_bytes) {
1799 if (only_release_metadata) {
1800 btrfs_end_write_no_snapshoting(root);
1801 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1804 btrfs_delalloc_release_space(inode, data_reserved,
1805 round_down(pos, fs_info->sectorsize),
1810 extent_changeset_free(data_reserved);
1811 return num_written ? num_written : ret;
1814 static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
1816 struct file *file = iocb->ki_filp;
1817 struct inode *inode = file_inode(file);
1818 loff_t pos = iocb->ki_pos;
1820 ssize_t written_buffered;
1824 written = generic_file_direct_write(iocb, from);
1826 if (written < 0 || !iov_iter_count(from))
1830 written_buffered = __btrfs_buffered_write(file, from, pos);
1831 if (written_buffered < 0) {
1832 err = written_buffered;
1836 * Ensure all data is persisted. We want the next direct IO read to be
1837 * able to read what was just written.
1839 endbyte = pos + written_buffered - 1;
1840 err = btrfs_fdatawrite_range(inode, pos, endbyte);
1843 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
1846 written += written_buffered;
1847 iocb->ki_pos = pos + written_buffered;
1848 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
1849 endbyte >> PAGE_SHIFT);
1851 return written ? written : err;
1854 static void update_time_for_write(struct inode *inode)
1856 struct timespec now;
1858 if (IS_NOCMTIME(inode))
1861 now = current_time(inode);
1862 if (!timespec_equal(&inode->i_mtime, &now))
1863 inode->i_mtime = now;
1865 if (!timespec_equal(&inode->i_ctime, &now))
1866 inode->i_ctime = now;
1868 if (IS_I_VERSION(inode))
1869 inode_inc_iversion(inode);
1872 static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1873 struct iov_iter *from)
1875 struct file *file = iocb->ki_filp;
1876 struct inode *inode = file_inode(file);
1877 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1878 struct btrfs_root *root = BTRFS_I(inode)->root;
1881 ssize_t num_written = 0;
1882 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
1885 size_t count = iov_iter_count(from);
1889 if (!inode_trylock(inode)) {
1890 if (iocb->ki_flags & IOCB_NOWAIT)
1895 err = generic_write_checks(iocb, from);
1897 inode_unlock(inode);
1902 if (iocb->ki_flags & IOCB_NOWAIT) {
1904 * We will allocate space in case nodatacow is not set,
1907 if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1908 BTRFS_INODE_PREALLOC)) ||
1909 check_can_nocow(BTRFS_I(inode), pos, &count) <= 0) {
1910 inode_unlock(inode);
1915 current->backing_dev_info = inode_to_bdi(inode);
1916 err = file_remove_privs(file);
1918 inode_unlock(inode);
1923 * If BTRFS flips readonly due to some impossible error
1924 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1925 * although we have opened a file as writable, we have
1926 * to stop this write operation to ensure FS consistency.
1928 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1929 inode_unlock(inode);
1935 * We reserve space for updating the inode when we reserve space for the
1936 * extent we are going to write, so we will enospc out there. We don't
1937 * need to start yet another transaction to update the inode as we will
1938 * update the inode when we finish writing whatever data we write.
1940 update_time_for_write(inode);
1942 start_pos = round_down(pos, fs_info->sectorsize);
1943 oldsize = i_size_read(inode);
1944 if (start_pos > oldsize) {
1945 /* Expand hole size to cover write data, preventing empty gap */
1946 end_pos = round_up(pos + count,
1947 fs_info->sectorsize);
1948 err = btrfs_cont_expand(inode, oldsize, end_pos);
1950 inode_unlock(inode);
1953 if (start_pos > round_up(oldsize, fs_info->sectorsize))
1958 atomic_inc(&BTRFS_I(inode)->sync_writers);
1960 if (iocb->ki_flags & IOCB_DIRECT) {
1961 num_written = __btrfs_direct_write(iocb, from);
1963 num_written = __btrfs_buffered_write(file, from, pos);
1964 if (num_written > 0)
1965 iocb->ki_pos = pos + num_written;
1967 pagecache_isize_extended(inode, oldsize,
1968 i_size_read(inode));
1971 inode_unlock(inode);
1974 * We also have to set last_sub_trans to the current log transid,
1975 * otherwise subsequent syncs to a file that's been synced in this
1976 * transaction will appear to have already occurred.
1978 spin_lock(&BTRFS_I(inode)->lock);
1979 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1980 spin_unlock(&BTRFS_I(inode)->lock);
1981 if (num_written > 0)
1982 num_written = generic_write_sync(iocb, num_written);
1985 atomic_dec(&BTRFS_I(inode)->sync_writers);
1987 current->backing_dev_info = NULL;
1988 return num_written ? num_written : err;
1991 int btrfs_release_file(struct inode *inode, struct file *filp)
1993 if (filp->private_data)
1994 btrfs_ioctl_trans_end(filp);
1996 * ordered_data_close is set by settattr when we are about to truncate
1997 * a file from a non-zero size to a zero size. This tries to
1998 * flush down new bytes that may have been written if the
1999 * application were using truncate to replace a file in place.
2001 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
2002 &BTRFS_I(inode)->runtime_flags))
2003 filemap_flush(inode->i_mapping);
2007 static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
2011 atomic_inc(&BTRFS_I(inode)->sync_writers);
2012 ret = btrfs_fdatawrite_range(inode, start, end);
2013 atomic_dec(&BTRFS_I(inode)->sync_writers);
2019 * fsync call for both files and directories. This logs the inode into
2020 * the tree log instead of forcing full commits whenever possible.
2022 * It needs to call filemap_fdatawait so that all ordered extent updates are
2023 * in the metadata btree are up to date for copying to the log.
2025 * It drops the inode mutex before doing the tree log commit. This is an
2026 * important optimization for directories because holding the mutex prevents
2027 * new operations on the dir while we write to disk.
2029 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
2031 struct dentry *dentry = file_dentry(file);
2032 struct inode *inode = d_inode(dentry);
2033 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2034 struct btrfs_root *root = BTRFS_I(inode)->root;
2035 struct btrfs_trans_handle *trans;
2036 struct btrfs_log_ctx ctx;
2042 * The range length can be represented by u64, we have to do the typecasts
2043 * to avoid signed overflow if it's [0, LLONG_MAX] eg. from fsync()
2045 len = (u64)end - (u64)start + 1;
2046 trace_btrfs_sync_file(file, datasync);
2049 * We write the dirty pages in the range and wait until they complete
2050 * out of the ->i_mutex. If so, we can flush the dirty pages by
2051 * multi-task, and make the performance up. See
2052 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
2054 ret = start_ordered_ops(inode, start, end);
2059 atomic_inc(&root->log_batch);
2060 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2061 &BTRFS_I(inode)->runtime_flags);
2063 * We might have have had more pages made dirty after calling
2064 * start_ordered_ops and before acquiring the inode's i_mutex.
2068 * For a full sync, we need to make sure any ordered operations
2069 * start and finish before we start logging the inode, so that
2070 * all extents are persisted and the respective file extent
2071 * items are in the fs/subvol btree.
2073 ret = btrfs_wait_ordered_range(inode, start, len);
2076 * Start any new ordered operations before starting to log the
2077 * inode. We will wait for them to finish in btrfs_sync_log().
2079 * Right before acquiring the inode's mutex, we might have new
2080 * writes dirtying pages, which won't immediately start the
2081 * respective ordered operations - that is done through the
2082 * fill_delalloc callbacks invoked from the writepage and
2083 * writepages address space operations. So make sure we start
2084 * all ordered operations before starting to log our inode. Not
2085 * doing this means that while logging the inode, writeback
2086 * could start and invoke writepage/writepages, which would call
2087 * the fill_delalloc callbacks (cow_file_range,
2088 * submit_compressed_extents). These callbacks add first an
2089 * extent map to the modified list of extents and then create
2090 * the respective ordered operation, which means in
2091 * tree-log.c:btrfs_log_inode() we might capture all existing
2092 * ordered operations (with btrfs_get_logged_extents()) before
2093 * the fill_delalloc callback adds its ordered operation, and by
2094 * the time we visit the modified list of extent maps (with
2095 * btrfs_log_changed_extents()), we see and process the extent
2096 * map they created. We then use the extent map to construct a
2097 * file extent item for logging without waiting for the
2098 * respective ordered operation to finish - this file extent
2099 * item points to a disk location that might not have yet been
2100 * written to, containing random data - so after a crash a log
2101 * replay will make our inode have file extent items that point
2102 * to disk locations containing invalid data, as we returned
2103 * success to userspace without waiting for the respective
2104 * ordered operation to finish, because it wasn't captured by
2105 * btrfs_get_logged_extents().
2107 ret = start_ordered_ops(inode, start, end);
2110 inode_unlock(inode);
2113 atomic_inc(&root->log_batch);
2116 * If the last transaction that changed this file was before the current
2117 * transaction and we have the full sync flag set in our inode, we can
2118 * bail out now without any syncing.
2120 * Note that we can't bail out if the full sync flag isn't set. This is
2121 * because when the full sync flag is set we start all ordered extents
2122 * and wait for them to fully complete - when they complete they update
2123 * the inode's last_trans field through:
2125 * btrfs_finish_ordered_io() ->
2126 * btrfs_update_inode_fallback() ->
2127 * btrfs_update_inode() ->
2128 * btrfs_set_inode_last_trans()
2130 * So we are sure that last_trans is up to date and can do this check to
2131 * bail out safely. For the fast path, when the full sync flag is not
2132 * set in our inode, we can not do it because we start only our ordered
2133 * extents and don't wait for them to complete (that is when
2134 * btrfs_finish_ordered_io runs), so here at this point their last_trans
2135 * value might be less than or equals to fs_info->last_trans_committed,
2136 * and setting a speculative last_trans for an inode when a buffered
2137 * write is made (such as fs_info->generation + 1 for example) would not
2138 * be reliable since after setting the value and before fsync is called
2139 * any number of transactions can start and commit (transaction kthread
2140 * commits the current transaction periodically), and a transaction
2141 * commit does not start nor waits for ordered extents to complete.
2144 if (btrfs_inode_in_log(BTRFS_I(inode), fs_info->generation) ||
2145 (full_sync && BTRFS_I(inode)->last_trans <=
2146 fs_info->last_trans_committed) ||
2147 (!btrfs_have_ordered_extents_in_range(inode, start, len) &&
2148 BTRFS_I(inode)->last_trans
2149 <= fs_info->last_trans_committed)) {
2151 * We've had everything committed since the last time we were
2152 * modified so clear this flag in case it was set for whatever
2153 * reason, it's no longer relevant.
2155 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2156 &BTRFS_I(inode)->runtime_flags);
2158 * An ordered extent might have started before and completed
2159 * already with io errors, in which case the inode was not
2160 * updated and we end up here. So check the inode's mapping
2161 * for any errors that might have happened since we last
2162 * checked called fsync.
2164 ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err);
2165 inode_unlock(inode);
2170 * ok we haven't committed the transaction yet, lets do a commit
2172 if (file->private_data)
2173 btrfs_ioctl_trans_end(file);
2176 * We use start here because we will need to wait on the IO to complete
2177 * in btrfs_sync_log, which could require joining a transaction (for
2178 * example checking cross references in the nocow path). If we use join
2179 * here we could get into a situation where we're waiting on IO to
2180 * happen that is blocked on a transaction trying to commit. With start
2181 * we inc the extwriter counter, so we wait for all extwriters to exit
2182 * before we start blocking join'ers. This comment is to keep somebody
2183 * from thinking they are super smart and changing this to
2184 * btrfs_join_transaction *cough*Josef*cough*.
2186 trans = btrfs_start_transaction(root, 0);
2187 if (IS_ERR(trans)) {
2188 ret = PTR_ERR(trans);
2189 inode_unlock(inode);
2194 btrfs_init_log_ctx(&ctx, inode);
2196 ret = btrfs_log_dentry_safe(trans, root, dentry, start, end, &ctx);
2198 /* Fallthrough and commit/free transaction. */
2202 /* we've logged all the items and now have a consistent
2203 * version of the file in the log. It is possible that
2204 * someone will come in and modify the file, but that's
2205 * fine because the log is consistent on disk, and we
2206 * have references to all of the file's extents
2208 * It is possible that someone will come in and log the
2209 * file again, but that will end up using the synchronization
2210 * inside btrfs_sync_log to keep things safe.
2212 inode_unlock(inode);
2215 * If any of the ordered extents had an error, just return it to user
2216 * space, so that the application knows some writes didn't succeed and
2217 * can take proper action (retry for e.g.). Blindly committing the
2218 * transaction in this case, would fool userspace that everything was
2219 * successful. And we also want to make sure our log doesn't contain
2220 * file extent items pointing to extents that weren't fully written to -
2221 * just like in the non fast fsync path, where we check for the ordered
2222 * operation's error flag before writing to the log tree and return -EIO
2223 * if any of them had this flag set (btrfs_wait_ordered_range) -
2224 * therefore we need to check for errors in the ordered operations,
2225 * which are indicated by ctx.io_err.
2228 btrfs_end_transaction(trans);
2233 if (ret != BTRFS_NO_LOG_SYNC) {
2235 ret = btrfs_sync_log(trans, root, &ctx);
2237 ret = btrfs_end_transaction(trans);
2242 ret = btrfs_wait_ordered_range(inode, start, len);
2244 btrfs_end_transaction(trans);
2248 ret = btrfs_commit_transaction(trans);
2250 ret = btrfs_end_transaction(trans);
2253 err = file_check_and_advance_wb_err(file);
2256 return ret > 0 ? -EIO : ret;
2259 static const struct vm_operations_struct btrfs_file_vm_ops = {
2260 .fault = filemap_fault,
2261 .map_pages = filemap_map_pages,
2262 .page_mkwrite = btrfs_page_mkwrite,
2265 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2267 struct address_space *mapping = filp->f_mapping;
2269 if (!mapping->a_ops->readpage)
2272 file_accessed(filp);
2273 vma->vm_ops = &btrfs_file_vm_ops;
2278 static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf,
2279 int slot, u64 start, u64 end)
2281 struct btrfs_file_extent_item *fi;
2282 struct btrfs_key key;
2284 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2287 btrfs_item_key_to_cpu(leaf, &key, slot);
2288 if (key.objectid != btrfs_ino(inode) ||
2289 key.type != BTRFS_EXTENT_DATA_KEY)
2292 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2294 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2297 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2300 if (key.offset == end)
2302 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2307 static int fill_holes(struct btrfs_trans_handle *trans,
2308 struct btrfs_inode *inode,
2309 struct btrfs_path *path, u64 offset, u64 end)
2311 struct btrfs_fs_info *fs_info = btrfs_sb(inode->vfs_inode.i_sb);
2312 struct btrfs_root *root = inode->root;
2313 struct extent_buffer *leaf;
2314 struct btrfs_file_extent_item *fi;
2315 struct extent_map *hole_em;
2316 struct extent_map_tree *em_tree = &inode->extent_tree;
2317 struct btrfs_key key;
2320 if (btrfs_fs_incompat(fs_info, NO_HOLES))
2323 key.objectid = btrfs_ino(inode);
2324 key.type = BTRFS_EXTENT_DATA_KEY;
2325 key.offset = offset;
2327 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2330 * We should have dropped this offset, so if we find it then
2331 * something has gone horribly wrong.
2338 leaf = path->nodes[0];
2339 if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) {
2343 fi = btrfs_item_ptr(leaf, path->slots[0],
2344 struct btrfs_file_extent_item);
2345 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2347 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2348 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2349 btrfs_set_file_extent_offset(leaf, fi, 0);
2350 btrfs_mark_buffer_dirty(leaf);
2354 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2357 key.offset = offset;
2358 btrfs_set_item_key_safe(fs_info, path, &key);
2359 fi = btrfs_item_ptr(leaf, path->slots[0],
2360 struct btrfs_file_extent_item);
2361 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2363 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2364 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2365 btrfs_set_file_extent_offset(leaf, fi, 0);
2366 btrfs_mark_buffer_dirty(leaf);
2369 btrfs_release_path(path);
2371 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode),
2372 offset, 0, 0, end - offset, 0, end - offset, 0, 0, 0);
2377 btrfs_release_path(path);
2379 hole_em = alloc_extent_map();
2381 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2382 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
2384 hole_em->start = offset;
2385 hole_em->len = end - offset;
2386 hole_em->ram_bytes = hole_em->len;
2387 hole_em->orig_start = offset;
2389 hole_em->block_start = EXTENT_MAP_HOLE;
2390 hole_em->block_len = 0;
2391 hole_em->orig_block_len = 0;
2392 hole_em->bdev = fs_info->fs_devices->latest_bdev;
2393 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2394 hole_em->generation = trans->transid;
2397 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2398 write_lock(&em_tree->lock);
2399 ret = add_extent_mapping(em_tree, hole_em, 1);
2400 write_unlock(&em_tree->lock);
2401 } while (ret == -EEXIST);
2402 free_extent_map(hole_em);
2404 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2405 &inode->runtime_flags);
2412 * Find a hole extent on given inode and change start/len to the end of hole
2413 * extent.(hole/vacuum extent whose em->start <= start &&
2414 * em->start + em->len > start)
2415 * When a hole extent is found, return 1 and modify start/len.
2417 static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)
2419 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2420 struct extent_map *em;
2423 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2424 round_down(*start, fs_info->sectorsize),
2425 round_up(*len, fs_info->sectorsize), 0);
2429 /* Hole or vacuum extent(only exists in no-hole mode) */
2430 if (em->block_start == EXTENT_MAP_HOLE) {
2432 *len = em->start + em->len > *start + *len ?
2433 0 : *start + *len - em->start - em->len;
2434 *start = em->start + em->len;
2436 free_extent_map(em);
2440 static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2442 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2443 struct btrfs_root *root = BTRFS_I(inode)->root;
2444 struct extent_state *cached_state = NULL;
2445 struct btrfs_path *path;
2446 struct btrfs_block_rsv *rsv;
2447 struct btrfs_trans_handle *trans;
2452 u64 orig_start = offset;
2454 u64 min_size = btrfs_calc_trans_metadata_size(fs_info, 1);
2458 unsigned int rsv_count;
2460 bool no_holes = btrfs_fs_incompat(fs_info, NO_HOLES);
2462 bool truncated_block = false;
2463 bool updated_inode = false;
2465 ret = btrfs_wait_ordered_range(inode, offset, len);
2470 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2471 ret = find_first_non_hole(inode, &offset, &len);
2473 goto out_only_mutex;
2475 /* Already in a large hole */
2477 goto out_only_mutex;
2480 lockstart = round_up(offset, btrfs_inode_sectorsize(inode));
2481 lockend = round_down(offset + len,
2482 btrfs_inode_sectorsize(inode)) - 1;
2483 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset))
2484 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1));
2486 * We needn't truncate any block which is beyond the end of the file
2487 * because we are sure there is no data there.
2490 * Only do this if we are in the same block and we aren't doing the
2493 if (same_block && len < fs_info->sectorsize) {
2494 if (offset < ino_size) {
2495 truncated_block = true;
2496 ret = btrfs_truncate_block(inode, offset, len, 0);
2500 goto out_only_mutex;
2503 /* zero back part of the first block */
2504 if (offset < ino_size) {
2505 truncated_block = true;
2506 ret = btrfs_truncate_block(inode, offset, 0, 0);
2508 inode_unlock(inode);
2513 /* Check the aligned pages after the first unaligned page,
2514 * if offset != orig_start, which means the first unaligned page
2515 * including several following pages are already in holes,
2516 * the extra check can be skipped */
2517 if (offset == orig_start) {
2518 /* after truncate page, check hole again */
2519 len = offset + len - lockstart;
2521 ret = find_first_non_hole(inode, &offset, &len);
2523 goto out_only_mutex;
2526 goto out_only_mutex;
2531 /* Check the tail unaligned part is in a hole */
2532 tail_start = lockend + 1;
2533 tail_len = offset + len - tail_start;
2535 ret = find_first_non_hole(inode, &tail_start, &tail_len);
2536 if (unlikely(ret < 0))
2537 goto out_only_mutex;
2539 /* zero the front end of the last page */
2540 if (tail_start + tail_len < ino_size) {
2541 truncated_block = true;
2542 ret = btrfs_truncate_block(inode,
2543 tail_start + tail_len,
2546 goto out_only_mutex;
2551 if (lockend < lockstart) {
2553 goto out_only_mutex;
2557 struct btrfs_ordered_extent *ordered;
2559 truncate_pagecache_range(inode, lockstart, lockend);
2561 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2563 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2566 * We need to make sure we have no ordered extents in this range
2567 * and nobody raced in and read a page in this range, if we did
2568 * we need to try again.
2571 (ordered->file_offset + ordered->len <= lockstart ||
2572 ordered->file_offset > lockend)) &&
2573 !btrfs_page_exists_in_range(inode, lockstart, lockend)) {
2575 btrfs_put_ordered_extent(ordered);
2579 btrfs_put_ordered_extent(ordered);
2580 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2581 lockend, &cached_state, GFP_NOFS);
2582 ret = btrfs_wait_ordered_range(inode, lockstart,
2583 lockend - lockstart + 1);
2585 inode_unlock(inode);
2590 path = btrfs_alloc_path();
2596 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
2601 rsv->size = btrfs_calc_trans_metadata_size(fs_info, 1);
2605 * 1 - update the inode
2606 * 1 - removing the extents in the range
2607 * 1 - adding the hole extent if no_holes isn't set
2609 rsv_count = no_holes ? 2 : 3;
2610 trans = btrfs_start_transaction(root, rsv_count);
2611 if (IS_ERR(trans)) {
2612 err = PTR_ERR(trans);
2616 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
2619 trans->block_rsv = rsv;
2621 cur_offset = lockstart;
2622 len = lockend - cur_offset;
2623 while (cur_offset < lockend) {
2624 ret = __btrfs_drop_extents(trans, root, inode, path,
2625 cur_offset, lockend + 1,
2626 &drop_end, 1, 0, 0, NULL);
2630 trans->block_rsv = &fs_info->trans_block_rsv;
2632 if (cur_offset < drop_end && cur_offset < ino_size) {
2633 ret = fill_holes(trans, BTRFS_I(inode), path,
2634 cur_offset, drop_end);
2637 * If we failed then we didn't insert our hole
2638 * entries for the area we dropped, so now the
2639 * fs is corrupted, so we must abort the
2642 btrfs_abort_transaction(trans, ret);
2648 cur_offset = drop_end;
2650 ret = btrfs_update_inode(trans, root, inode);
2656 btrfs_end_transaction(trans);
2657 btrfs_btree_balance_dirty(fs_info);
2659 trans = btrfs_start_transaction(root, rsv_count);
2660 if (IS_ERR(trans)) {
2661 ret = PTR_ERR(trans);
2666 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
2668 BUG_ON(ret); /* shouldn't happen */
2669 trans->block_rsv = rsv;
2671 ret = find_first_non_hole(inode, &cur_offset, &len);
2672 if (unlikely(ret < 0))
2685 trans->block_rsv = &fs_info->trans_block_rsv;
2687 * If we are using the NO_HOLES feature we might have had already an
2688 * hole that overlaps a part of the region [lockstart, lockend] and
2689 * ends at (or beyond) lockend. Since we have no file extent items to
2690 * represent holes, drop_end can be less than lockend and so we must
2691 * make sure we have an extent map representing the existing hole (the
2692 * call to __btrfs_drop_extents() might have dropped the existing extent
2693 * map representing the existing hole), otherwise the fast fsync path
2694 * will not record the existence of the hole region
2695 * [existing_hole_start, lockend].
2697 if (drop_end <= lockend)
2698 drop_end = lockend + 1;
2700 * Don't insert file hole extent item if it's for a range beyond eof
2701 * (because it's useless) or if it represents a 0 bytes range (when
2702 * cur_offset == drop_end).
2704 if (cur_offset < ino_size && cur_offset < drop_end) {
2705 ret = fill_holes(trans, BTRFS_I(inode), path,
2706 cur_offset, drop_end);
2708 /* Same comment as above. */
2709 btrfs_abort_transaction(trans, ret);
2719 inode_inc_iversion(inode);
2720 inode->i_mtime = inode->i_ctime = current_time(inode);
2722 trans->block_rsv = &fs_info->trans_block_rsv;
2723 ret = btrfs_update_inode(trans, root, inode);
2724 updated_inode = true;
2725 btrfs_end_transaction(trans);
2726 btrfs_btree_balance_dirty(fs_info);
2728 btrfs_free_path(path);
2729 btrfs_free_block_rsv(fs_info, rsv);
2731 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2732 &cached_state, GFP_NOFS);
2734 if (!updated_inode && truncated_block && !ret && !err) {
2736 * If we only end up zeroing part of a page, we still need to
2737 * update the inode item, so that all the time fields are
2738 * updated as well as the necessary btrfs inode in memory fields
2739 * for detecting, at fsync time, if the inode isn't yet in the
2740 * log tree or it's there but not up to date.
2742 trans = btrfs_start_transaction(root, 1);
2743 if (IS_ERR(trans)) {
2744 err = PTR_ERR(trans);
2746 err = btrfs_update_inode(trans, root, inode);
2747 ret = btrfs_end_transaction(trans);
2750 inode_unlock(inode);
2756 /* Helper structure to record which range is already reserved */
2757 struct falloc_range {
2758 struct list_head list;
2764 * Helper function to add falloc range
2766 * Caller should have locked the larger range of extent containing
2769 static int add_falloc_range(struct list_head *head, u64 start, u64 len)
2771 struct falloc_range *prev = NULL;
2772 struct falloc_range *range = NULL;
2774 if (list_empty(head))
2778 * As fallocate iterate by bytenr order, we only need to check
2781 prev = list_entry(head->prev, struct falloc_range, list);
2782 if (prev->start + prev->len == start) {
2787 range = kmalloc(sizeof(*range), GFP_KERNEL);
2790 range->start = start;
2792 list_add_tail(&range->list, head);
2796 static long btrfs_fallocate(struct file *file, int mode,
2797 loff_t offset, loff_t len)
2799 struct inode *inode = file_inode(file);
2800 struct extent_state *cached_state = NULL;
2801 struct extent_changeset *data_reserved = NULL;
2802 struct falloc_range *range;
2803 struct falloc_range *tmp;
2804 struct list_head reserve_list;
2812 struct extent_map *em;
2813 int blocksize = btrfs_inode_sectorsize(inode);
2816 alloc_start = round_down(offset, blocksize);
2817 alloc_end = round_up(offset + len, blocksize);
2818 cur_offset = alloc_start;
2820 /* Make sure we aren't being give some crap mode */
2821 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
2824 if (mode & FALLOC_FL_PUNCH_HOLE)
2825 return btrfs_punch_hole(inode, offset, len);
2828 * Only trigger disk allocation, don't trigger qgroup reserve
2830 * For qgroup space, it will be checked later.
2832 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
2833 alloc_end - alloc_start);
2839 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
2840 ret = inode_newsize_ok(inode, offset + len);
2846 * TODO: Move these two operations after we have checked
2847 * accurate reserved space, or fallocate can still fail but
2848 * with page truncated or size expanded.
2850 * But that's a minor problem and won't do much harm BTW.
2852 if (alloc_start > inode->i_size) {
2853 ret = btrfs_cont_expand(inode, i_size_read(inode),
2857 } else if (offset + len > inode->i_size) {
2859 * If we are fallocating from the end of the file onward we
2860 * need to zero out the end of the block if i_size lands in the
2861 * middle of a block.
2863 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
2869 * wait for ordered IO before we have any locks. We'll loop again
2870 * below with the locks held.
2872 ret = btrfs_wait_ordered_range(inode, alloc_start,
2873 alloc_end - alloc_start);
2877 locked_end = alloc_end - 1;
2879 struct btrfs_ordered_extent *ordered;
2881 /* the extent lock is ordered inside the running
2884 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
2885 locked_end, &cached_state);
2886 ordered = btrfs_lookup_first_ordered_extent(inode,
2889 ordered->file_offset + ordered->len > alloc_start &&
2890 ordered->file_offset < alloc_end) {
2891 btrfs_put_ordered_extent(ordered);
2892 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
2893 alloc_start, locked_end,
2894 &cached_state, GFP_KERNEL);
2896 * we can't wait on the range with the transaction
2897 * running or with the extent lock held
2899 ret = btrfs_wait_ordered_range(inode, alloc_start,
2900 alloc_end - alloc_start);
2905 btrfs_put_ordered_extent(ordered);
2910 /* First, check if we exceed the qgroup limit */
2911 INIT_LIST_HEAD(&reserve_list);
2913 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
2914 alloc_end - cur_offset, 0);
2919 last_byte = min(extent_map_end(em), alloc_end);
2920 actual_end = min_t(u64, extent_map_end(em), offset + len);
2921 last_byte = ALIGN(last_byte, blocksize);
2922 if (em->block_start == EXTENT_MAP_HOLE ||
2923 (cur_offset >= inode->i_size &&
2924 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
2925 ret = add_falloc_range(&reserve_list, cur_offset,
2926 last_byte - cur_offset);
2928 free_extent_map(em);
2931 ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
2932 cur_offset, last_byte - cur_offset);
2934 free_extent_map(em);
2939 * Do not need to reserve unwritten extent for this
2940 * range, free reserved data space first, otherwise
2941 * it'll result in false ENOSPC error.
2943 btrfs_free_reserved_data_space(inode, data_reserved,
2944 cur_offset, last_byte - cur_offset);
2946 free_extent_map(em);
2947 cur_offset = last_byte;
2948 if (cur_offset >= alloc_end)
2953 * If ret is still 0, means we're OK to fallocate.
2954 * Or just cleanup the list and exit.
2956 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
2958 ret = btrfs_prealloc_file_range(inode, mode,
2960 range->len, i_blocksize(inode),
2961 offset + len, &alloc_hint);
2963 btrfs_free_reserved_data_space(inode,
2964 data_reserved, range->start,
2966 list_del(&range->list);
2972 if (actual_end > inode->i_size &&
2973 !(mode & FALLOC_FL_KEEP_SIZE)) {
2974 struct btrfs_trans_handle *trans;
2975 struct btrfs_root *root = BTRFS_I(inode)->root;
2978 * We didn't need to allocate any more space, but we
2979 * still extended the size of the file so we need to
2980 * update i_size and the inode item.
2982 trans = btrfs_start_transaction(root, 1);
2983 if (IS_ERR(trans)) {
2984 ret = PTR_ERR(trans);
2986 inode->i_ctime = current_time(inode);
2987 i_size_write(inode, actual_end);
2988 btrfs_ordered_update_i_size(inode, actual_end, NULL);
2989 ret = btrfs_update_inode(trans, root, inode);
2991 btrfs_end_transaction(trans);
2993 ret = btrfs_end_transaction(trans);
2997 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
2998 &cached_state, GFP_KERNEL);
3000 inode_unlock(inode);
3001 /* Let go of our reservation. */
3003 btrfs_free_reserved_data_space(inode, data_reserved,
3004 alloc_start, alloc_end - cur_offset);
3005 extent_changeset_free(data_reserved);
3009 static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
3011 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3012 struct extent_map *em = NULL;
3013 struct extent_state *cached_state = NULL;
3020 if (inode->i_size == 0)
3024 * *offset can be negative, in this case we start finding DATA/HOLE from
3025 * the very start of the file.
3027 start = max_t(loff_t, 0, *offset);
3029 lockstart = round_down(start, fs_info->sectorsize);
3030 lockend = round_up(i_size_read(inode),
3031 fs_info->sectorsize);
3032 if (lockend <= lockstart)
3033 lockend = lockstart + fs_info->sectorsize;
3035 len = lockend - lockstart + 1;
3037 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3040 while (start < inode->i_size) {
3041 em = btrfs_get_extent_fiemap(BTRFS_I(inode), NULL, 0,
3049 if (whence == SEEK_HOLE &&
3050 (em->block_start == EXTENT_MAP_HOLE ||
3051 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3053 else if (whence == SEEK_DATA &&
3054 (em->block_start != EXTENT_MAP_HOLE &&
3055 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3058 start = em->start + em->len;
3059 free_extent_map(em);
3063 free_extent_map(em);
3065 if (whence == SEEK_DATA && start >= inode->i_size)
3068 *offset = min_t(loff_t, start, inode->i_size);
3070 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3071 &cached_state, GFP_NOFS);
3075 static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
3077 struct inode *inode = file->f_mapping->host;
3084 offset = generic_file_llseek(file, offset, whence);
3088 if (offset >= i_size_read(inode)) {
3089 inode_unlock(inode);
3093 ret = find_desired_extent(inode, &offset, whence);
3095 inode_unlock(inode);
3100 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
3102 inode_unlock(inode);
3106 static int btrfs_file_open(struct inode *inode, struct file *filp)
3108 filp->f_mode |= FMODE_AIO_NOWAIT;
3109 return generic_file_open(inode, filp);
3112 const struct file_operations btrfs_file_operations = {
3113 .llseek = btrfs_file_llseek,
3114 .read_iter = generic_file_read_iter,
3115 .splice_read = generic_file_splice_read,
3116 .write_iter = btrfs_file_write_iter,
3117 .mmap = btrfs_file_mmap,
3118 .open = btrfs_file_open,
3119 .release = btrfs_release_file,
3120 .fsync = btrfs_sync_file,
3121 .fallocate = btrfs_fallocate,
3122 .unlocked_ioctl = btrfs_ioctl,
3123 #ifdef CONFIG_COMPAT
3124 .compat_ioctl = btrfs_compat_ioctl,
3126 .clone_file_range = btrfs_clone_file_range,
3127 .dedupe_file_range = btrfs_dedupe_file_range,
3130 void btrfs_auto_defrag_exit(void)
3132 kmem_cache_destroy(btrfs_inode_defrag_cachep);
3135 int btrfs_auto_defrag_init(void)
3137 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
3138 sizeof(struct inode_defrag), 0,
3141 if (!btrfs_inode_defrag_cachep)
3147 int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
3152 * So with compression we will find and lock a dirty page and clear the
3153 * first one as dirty, setup an async extent, and immediately return
3154 * with the entire range locked but with nobody actually marked with
3155 * writeback. So we can't just filemap_write_and_wait_range() and
3156 * expect it to work since it will just kick off a thread to do the
3157 * actual work. So we need to call filemap_fdatawrite_range _again_
3158 * since it will wait on the page lock, which won't be unlocked until
3159 * after the pages have been marked as writeback and so we're good to go
3160 * from there. We have to do this otherwise we'll miss the ordered
3161 * extents and that results in badness. Please Josef, do not think you
3162 * know better and pull this out at some point in the future, it is
3163 * right and you are wrong.
3165 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3166 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
3167 &BTRFS_I(inode)->runtime_flags))
3168 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);