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 inode *inode,
96 struct inode_defrag *defrag)
98 struct btrfs_fs_info *fs_info = btrfs_sb(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, &BTRFS_I(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,
150 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
151 struct btrfs_root *root = BTRFS_I(inode)->root;
152 struct inode_defrag *defrag;
156 if (!__need_auto_defrag(fs_info))
159 if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags))
163 transid = trans->transid;
165 transid = BTRFS_I(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, &BTRFS_I(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 inode *inode,
198 struct inode_defrag *defrag)
200 struct btrfs_fs_info *fs_info = btrfs_sb(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(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(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 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 = &BTRFS_I(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(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(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 inode *inode, u64 start, u64 end)
1087 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1088 struct btrfs_root *root = BTRFS_I(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]);
1408 * This function locks the extent and properly waits for data=ordered extents
1409 * to finish before allowing the pages to be modified if need.
1412 * 1 - the extent is locked
1413 * 0 - the extent is not locked, and everything is OK
1414 * -EAGAIN - need re-prepare the pages
1415 * the other < 0 number - Something wrong happens
1418 lock_and_cleanup_extent_if_need(struct inode *inode, struct page **pages,
1419 size_t num_pages, loff_t pos,
1421 u64 *lockstart, u64 *lockend,
1422 struct extent_state **cached_state)
1424 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1430 start_pos = round_down(pos, fs_info->sectorsize);
1431 last_pos = start_pos
1432 + round_up(pos + write_bytes - start_pos,
1433 fs_info->sectorsize) - 1;
1435 if (start_pos < inode->i_size) {
1436 struct btrfs_ordered_extent *ordered;
1437 lock_extent_bits(&BTRFS_I(inode)->io_tree,
1438 start_pos, last_pos, cached_state);
1439 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1440 last_pos - start_pos + 1);
1442 ordered->file_offset + ordered->len > start_pos &&
1443 ordered->file_offset <= last_pos) {
1444 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1445 start_pos, last_pos,
1446 cached_state, GFP_NOFS);
1447 for (i = 0; i < num_pages; i++) {
1448 unlock_page(pages[i]);
1451 btrfs_start_ordered_extent(inode, ordered, 1);
1452 btrfs_put_ordered_extent(ordered);
1456 btrfs_put_ordered_extent(ordered);
1458 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
1459 last_pos, EXTENT_DIRTY | EXTENT_DELALLOC |
1460 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
1461 0, 0, cached_state, GFP_NOFS);
1462 *lockstart = start_pos;
1463 *lockend = last_pos;
1467 for (i = 0; i < num_pages; i++) {
1468 if (clear_page_dirty_for_io(pages[i]))
1469 account_page_redirty(pages[i]);
1470 set_page_extent_mapped(pages[i]);
1471 WARN_ON(!PageLocked(pages[i]));
1477 static noinline int check_can_nocow(struct inode *inode, loff_t pos,
1478 size_t *write_bytes)
1480 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1481 struct btrfs_root *root = BTRFS_I(inode)->root;
1482 struct btrfs_ordered_extent *ordered;
1483 u64 lockstart, lockend;
1487 ret = btrfs_start_write_no_snapshoting(root);
1491 lockstart = round_down(pos, fs_info->sectorsize);
1492 lockend = round_up(pos + *write_bytes,
1493 fs_info->sectorsize) - 1;
1496 lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1497 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1498 lockend - lockstart + 1);
1502 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1503 btrfs_start_ordered_extent(inode, ordered, 1);
1504 btrfs_put_ordered_extent(ordered);
1507 num_bytes = lockend - lockstart + 1;
1508 ret = can_nocow_extent(inode, lockstart, &num_bytes, NULL, NULL, NULL);
1511 btrfs_end_write_no_snapshoting(root);
1513 *write_bytes = min_t(size_t, *write_bytes ,
1514 num_bytes - pos + lockstart);
1517 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1522 static noinline ssize_t __btrfs_buffered_write(struct file *file,
1526 struct inode *inode = file_inode(file);
1527 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1528 struct btrfs_root *root = BTRFS_I(inode)->root;
1529 struct page **pages = NULL;
1530 struct extent_state *cached_state = NULL;
1531 u64 release_bytes = 0;
1534 size_t num_written = 0;
1537 bool only_release_metadata = false;
1538 bool force_page_uptodate = false;
1541 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
1542 PAGE_SIZE / (sizeof(struct page *)));
1543 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1544 nrptrs = max(nrptrs, 8);
1545 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1549 while (iov_iter_count(i) > 0) {
1550 size_t offset = pos & (PAGE_SIZE - 1);
1551 size_t sector_offset;
1552 size_t write_bytes = min(iov_iter_count(i),
1553 nrptrs * (size_t)PAGE_SIZE -
1555 size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
1557 size_t reserve_bytes;
1560 size_t dirty_sectors;
1563 WARN_ON(num_pages > nrptrs);
1566 * Fault pages before locking them in prepare_pages
1567 * to avoid recursive lock
1569 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1574 sector_offset = pos & (fs_info->sectorsize - 1);
1575 reserve_bytes = round_up(write_bytes + sector_offset,
1576 fs_info->sectorsize);
1578 ret = btrfs_check_data_free_space(inode, pos, write_bytes);
1580 if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1581 BTRFS_INODE_PREALLOC)) &&
1582 check_can_nocow(inode, pos, &write_bytes) > 0) {
1584 * For nodata cow case, no need to reserve
1587 only_release_metadata = true;
1589 * our prealloc extent may be smaller than
1590 * write_bytes, so scale down.
1592 num_pages = DIV_ROUND_UP(write_bytes + offset,
1594 reserve_bytes = round_up(write_bytes +
1596 fs_info->sectorsize);
1602 ret = btrfs_delalloc_reserve_metadata(inode, reserve_bytes);
1604 if (!only_release_metadata)
1605 btrfs_free_reserved_data_space(inode, pos,
1608 btrfs_end_write_no_snapshoting(root);
1612 release_bytes = reserve_bytes;
1613 need_unlock = false;
1616 * This is going to setup the pages array with the number of
1617 * pages we want, so we don't really need to worry about the
1618 * contents of pages from loop to loop
1620 ret = prepare_pages(inode, pages, num_pages,
1622 force_page_uptodate);
1626 ret = lock_and_cleanup_extent_if_need(inode, pages, num_pages,
1627 pos, write_bytes, &lockstart,
1628 &lockend, &cached_state);
1633 } else if (ret > 0) {
1638 copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
1640 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes);
1641 dirty_sectors = round_up(copied + sector_offset,
1642 fs_info->sectorsize);
1643 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors);
1646 * if we have trouble faulting in the pages, fall
1647 * back to one page at a time
1649 if (copied < write_bytes)
1653 force_page_uptodate = true;
1657 force_page_uptodate = false;
1658 dirty_pages = DIV_ROUND_UP(copied + offset,
1663 * If we had a short copy we need to release the excess delaloc
1664 * bytes we reserved. We need to increment outstanding_extents
1665 * because btrfs_delalloc_release_space and
1666 * btrfs_delalloc_release_metadata will decrement it, but
1667 * we still have an outstanding extent for the chunk we actually
1670 if (num_sectors > dirty_sectors) {
1671 /* release everything except the sectors we dirtied */
1672 release_bytes -= dirty_sectors <<
1673 fs_info->sb->s_blocksize_bits;
1675 spin_lock(&BTRFS_I(inode)->lock);
1676 BTRFS_I(inode)->outstanding_extents++;
1677 spin_unlock(&BTRFS_I(inode)->lock);
1679 if (only_release_metadata) {
1680 btrfs_delalloc_release_metadata(inode,
1685 __pos = round_down(pos,
1686 fs_info->sectorsize) +
1687 (dirty_pages << PAGE_SHIFT);
1688 btrfs_delalloc_release_space(inode, __pos,
1693 release_bytes = round_up(copied + sector_offset,
1694 fs_info->sectorsize);
1697 ret = btrfs_dirty_pages(inode, pages, dirty_pages,
1700 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1701 lockstart, lockend, &cached_state,
1704 btrfs_drop_pages(pages, num_pages);
1709 if (only_release_metadata)
1710 btrfs_end_write_no_snapshoting(root);
1712 if (only_release_metadata && copied > 0) {
1713 lockstart = round_down(pos,
1714 fs_info->sectorsize);
1715 lockend = round_up(pos + copied,
1716 fs_info->sectorsize) - 1;
1718 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1719 lockend, EXTENT_NORESERVE, NULL,
1721 only_release_metadata = false;
1724 btrfs_drop_pages(pages, num_pages);
1728 balance_dirty_pages_ratelimited(inode->i_mapping);
1729 if (dirty_pages < (fs_info->nodesize >> PAGE_SHIFT) + 1)
1730 btrfs_btree_balance_dirty(fs_info);
1733 num_written += copied;
1738 if (release_bytes) {
1739 if (only_release_metadata) {
1740 btrfs_end_write_no_snapshoting(root);
1741 btrfs_delalloc_release_metadata(inode, release_bytes);
1743 btrfs_delalloc_release_space(inode,
1744 round_down(pos, fs_info->sectorsize),
1749 return num_written ? num_written : ret;
1752 static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
1754 struct file *file = iocb->ki_filp;
1755 struct inode *inode = file_inode(file);
1756 loff_t pos = iocb->ki_pos;
1758 ssize_t written_buffered;
1762 written = generic_file_direct_write(iocb, from);
1764 if (written < 0 || !iov_iter_count(from))
1768 written_buffered = __btrfs_buffered_write(file, from, pos);
1769 if (written_buffered < 0) {
1770 err = written_buffered;
1774 * Ensure all data is persisted. We want the next direct IO read to be
1775 * able to read what was just written.
1777 endbyte = pos + written_buffered - 1;
1778 err = btrfs_fdatawrite_range(inode, pos, endbyte);
1781 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
1784 written += written_buffered;
1785 iocb->ki_pos = pos + written_buffered;
1786 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
1787 endbyte >> PAGE_SHIFT);
1789 return written ? written : err;
1792 static void update_time_for_write(struct inode *inode)
1794 struct timespec now;
1796 if (IS_NOCMTIME(inode))
1799 now = current_time(inode);
1800 if (!timespec_equal(&inode->i_mtime, &now))
1801 inode->i_mtime = now;
1803 if (!timespec_equal(&inode->i_ctime, &now))
1804 inode->i_ctime = now;
1806 if (IS_I_VERSION(inode))
1807 inode_inc_iversion(inode);
1810 static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1811 struct iov_iter *from)
1813 struct file *file = iocb->ki_filp;
1814 struct inode *inode = file_inode(file);
1815 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1816 struct btrfs_root *root = BTRFS_I(inode)->root;
1819 ssize_t num_written = 0;
1820 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
1828 err = generic_write_checks(iocb, from);
1830 inode_unlock(inode);
1834 current->backing_dev_info = inode_to_bdi(inode);
1835 err = file_remove_privs(file);
1837 inode_unlock(inode);
1842 * If BTRFS flips readonly due to some impossible error
1843 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1844 * although we have opened a file as writable, we have
1845 * to stop this write operation to ensure FS consistency.
1847 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1848 inode_unlock(inode);
1854 * We reserve space for updating the inode when we reserve space for the
1855 * extent we are going to write, so we will enospc out there. We don't
1856 * need to start yet another transaction to update the inode as we will
1857 * update the inode when we finish writing whatever data we write.
1859 update_time_for_write(inode);
1862 count = iov_iter_count(from);
1863 start_pos = round_down(pos, fs_info->sectorsize);
1864 oldsize = i_size_read(inode);
1865 if (start_pos > oldsize) {
1866 /* Expand hole size to cover write data, preventing empty gap */
1867 end_pos = round_up(pos + count,
1868 fs_info->sectorsize);
1869 err = btrfs_cont_expand(inode, oldsize, end_pos);
1871 inode_unlock(inode);
1874 if (start_pos > round_up(oldsize, fs_info->sectorsize))
1879 atomic_inc(&BTRFS_I(inode)->sync_writers);
1881 if (iocb->ki_flags & IOCB_DIRECT) {
1882 num_written = __btrfs_direct_write(iocb, from);
1884 num_written = __btrfs_buffered_write(file, from, pos);
1885 if (num_written > 0)
1886 iocb->ki_pos = pos + num_written;
1888 pagecache_isize_extended(inode, oldsize,
1889 i_size_read(inode));
1892 inode_unlock(inode);
1895 * We also have to set last_sub_trans to the current log transid,
1896 * otherwise subsequent syncs to a file that's been synced in this
1897 * transaction will appear to have already occurred.
1899 spin_lock(&BTRFS_I(inode)->lock);
1900 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1901 spin_unlock(&BTRFS_I(inode)->lock);
1902 if (num_written > 0)
1903 num_written = generic_write_sync(iocb, num_written);
1906 atomic_dec(&BTRFS_I(inode)->sync_writers);
1908 current->backing_dev_info = NULL;
1909 return num_written ? num_written : err;
1912 int btrfs_release_file(struct inode *inode, struct file *filp)
1914 if (filp->private_data)
1915 btrfs_ioctl_trans_end(filp);
1917 * ordered_data_close is set by settattr when we are about to truncate
1918 * a file from a non-zero size to a zero size. This tries to
1919 * flush down new bytes that may have been written if the
1920 * application were using truncate to replace a file in place.
1922 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
1923 &BTRFS_I(inode)->runtime_flags))
1924 filemap_flush(inode->i_mapping);
1928 static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
1932 atomic_inc(&BTRFS_I(inode)->sync_writers);
1933 ret = btrfs_fdatawrite_range(inode, start, end);
1934 atomic_dec(&BTRFS_I(inode)->sync_writers);
1940 * fsync call for both files and directories. This logs the inode into
1941 * the tree log instead of forcing full commits whenever possible.
1943 * It needs to call filemap_fdatawait so that all ordered extent updates are
1944 * in the metadata btree are up to date for copying to the log.
1946 * It drops the inode mutex before doing the tree log commit. This is an
1947 * important optimization for directories because holding the mutex prevents
1948 * new operations on the dir while we write to disk.
1950 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
1952 struct dentry *dentry = file_dentry(file);
1953 struct inode *inode = d_inode(dentry);
1954 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1955 struct btrfs_root *root = BTRFS_I(inode)->root;
1956 struct btrfs_trans_handle *trans;
1957 struct btrfs_log_ctx ctx;
1963 * The range length can be represented by u64, we have to do the typecasts
1964 * to avoid signed overflow if it's [0, LLONG_MAX] eg. from fsync()
1966 len = (u64)end - (u64)start + 1;
1967 trace_btrfs_sync_file(file, datasync);
1970 * We write the dirty pages in the range and wait until they complete
1971 * out of the ->i_mutex. If so, we can flush the dirty pages by
1972 * multi-task, and make the performance up. See
1973 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
1975 ret = start_ordered_ops(inode, start, end);
1980 atomic_inc(&root->log_batch);
1981 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1982 &BTRFS_I(inode)->runtime_flags);
1984 * We might have have had more pages made dirty after calling
1985 * start_ordered_ops and before acquiring the inode's i_mutex.
1989 * For a full sync, we need to make sure any ordered operations
1990 * start and finish before we start logging the inode, so that
1991 * all extents are persisted and the respective file extent
1992 * items are in the fs/subvol btree.
1994 ret = btrfs_wait_ordered_range(inode, start, len);
1997 * Start any new ordered operations before starting to log the
1998 * inode. We will wait for them to finish in btrfs_sync_log().
2000 * Right before acquiring the inode's mutex, we might have new
2001 * writes dirtying pages, which won't immediately start the
2002 * respective ordered operations - that is done through the
2003 * fill_delalloc callbacks invoked from the writepage and
2004 * writepages address space operations. So make sure we start
2005 * all ordered operations before starting to log our inode. Not
2006 * doing this means that while logging the inode, writeback
2007 * could start and invoke writepage/writepages, which would call
2008 * the fill_delalloc callbacks (cow_file_range,
2009 * submit_compressed_extents). These callbacks add first an
2010 * extent map to the modified list of extents and then create
2011 * the respective ordered operation, which means in
2012 * tree-log.c:btrfs_log_inode() we might capture all existing
2013 * ordered operations (with btrfs_get_logged_extents()) before
2014 * the fill_delalloc callback adds its ordered operation, and by
2015 * the time we visit the modified list of extent maps (with
2016 * btrfs_log_changed_extents()), we see and process the extent
2017 * map they created. We then use the extent map to construct a
2018 * file extent item for logging without waiting for the
2019 * respective ordered operation to finish - this file extent
2020 * item points to a disk location that might not have yet been
2021 * written to, containing random data - so after a crash a log
2022 * replay will make our inode have file extent items that point
2023 * to disk locations containing invalid data, as we returned
2024 * success to userspace without waiting for the respective
2025 * ordered operation to finish, because it wasn't captured by
2026 * btrfs_get_logged_extents().
2028 ret = start_ordered_ops(inode, start, end);
2031 inode_unlock(inode);
2034 atomic_inc(&root->log_batch);
2037 * If the last transaction that changed this file was before the current
2038 * transaction and we have the full sync flag set in our inode, we can
2039 * bail out now without any syncing.
2041 * Note that we can't bail out if the full sync flag isn't set. This is
2042 * because when the full sync flag is set we start all ordered extents
2043 * and wait for them to fully complete - when they complete they update
2044 * the inode's last_trans field through:
2046 * btrfs_finish_ordered_io() ->
2047 * btrfs_update_inode_fallback() ->
2048 * btrfs_update_inode() ->
2049 * btrfs_set_inode_last_trans()
2051 * So we are sure that last_trans is up to date and can do this check to
2052 * bail out safely. For the fast path, when the full sync flag is not
2053 * set in our inode, we can not do it because we start only our ordered
2054 * extents and don't wait for them to complete (that is when
2055 * btrfs_finish_ordered_io runs), so here at this point their last_trans
2056 * value might be less than or equals to fs_info->last_trans_committed,
2057 * and setting a speculative last_trans for an inode when a buffered
2058 * write is made (such as fs_info->generation + 1 for example) would not
2059 * be reliable since after setting the value and before fsync is called
2060 * any number of transactions can start and commit (transaction kthread
2061 * commits the current transaction periodically), and a transaction
2062 * commit does not start nor waits for ordered extents to complete.
2065 if (btrfs_inode_in_log(inode, fs_info->generation) ||
2066 (full_sync && BTRFS_I(inode)->last_trans <=
2067 fs_info->last_trans_committed) ||
2068 (!btrfs_have_ordered_extents_in_range(inode, start, len) &&
2069 BTRFS_I(inode)->last_trans
2070 <= fs_info->last_trans_committed)) {
2072 * We've had everything committed since the last time we were
2073 * modified so clear this flag in case it was set for whatever
2074 * reason, it's no longer relevant.
2076 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2077 &BTRFS_I(inode)->runtime_flags);
2079 * An ordered extent might have started before and completed
2080 * already with io errors, in which case the inode was not
2081 * updated and we end up here. So check the inode's mapping
2082 * flags for any errors that might have happened while doing
2083 * writeback of file data.
2085 ret = filemap_check_errors(inode->i_mapping);
2086 inode_unlock(inode);
2091 * ok we haven't committed the transaction yet, lets do a commit
2093 if (file->private_data)
2094 btrfs_ioctl_trans_end(file);
2097 * We use start here because we will need to wait on the IO to complete
2098 * in btrfs_sync_log, which could require joining a transaction (for
2099 * example checking cross references in the nocow path). If we use join
2100 * here we could get into a situation where we're waiting on IO to
2101 * happen that is blocked on a transaction trying to commit. With start
2102 * we inc the extwriter counter, so we wait for all extwriters to exit
2103 * before we start blocking join'ers. This comment is to keep somebody
2104 * from thinking they are super smart and changing this to
2105 * btrfs_join_transaction *cough*Josef*cough*.
2107 trans = btrfs_start_transaction(root, 0);
2108 if (IS_ERR(trans)) {
2109 ret = PTR_ERR(trans);
2110 inode_unlock(inode);
2115 btrfs_init_log_ctx(&ctx, inode);
2117 ret = btrfs_log_dentry_safe(trans, root, dentry, start, end, &ctx);
2119 /* Fallthrough and commit/free transaction. */
2123 /* we've logged all the items and now have a consistent
2124 * version of the file in the log. It is possible that
2125 * someone will come in and modify the file, but that's
2126 * fine because the log is consistent on disk, and we
2127 * have references to all of the file's extents
2129 * It is possible that someone will come in and log the
2130 * file again, but that will end up using the synchronization
2131 * inside btrfs_sync_log to keep things safe.
2133 inode_unlock(inode);
2136 * If any of the ordered extents had an error, just return it to user
2137 * space, so that the application knows some writes didn't succeed and
2138 * can take proper action (retry for e.g.). Blindly committing the
2139 * transaction in this case, would fool userspace that everything was
2140 * successful. And we also want to make sure our log doesn't contain
2141 * file extent items pointing to extents that weren't fully written to -
2142 * just like in the non fast fsync path, where we check for the ordered
2143 * operation's error flag before writing to the log tree and return -EIO
2144 * if any of them had this flag set (btrfs_wait_ordered_range) -
2145 * therefore we need to check for errors in the ordered operations,
2146 * which are indicated by ctx.io_err.
2149 btrfs_end_transaction(trans);
2154 if (ret != BTRFS_NO_LOG_SYNC) {
2156 ret = btrfs_sync_log(trans, root, &ctx);
2158 ret = btrfs_end_transaction(trans);
2163 ret = btrfs_wait_ordered_range(inode, start, len);
2165 btrfs_end_transaction(trans);
2169 ret = btrfs_commit_transaction(trans);
2171 ret = btrfs_end_transaction(trans);
2174 return ret > 0 ? -EIO : ret;
2177 static const struct vm_operations_struct btrfs_file_vm_ops = {
2178 .fault = filemap_fault,
2179 .map_pages = filemap_map_pages,
2180 .page_mkwrite = btrfs_page_mkwrite,
2183 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2185 struct address_space *mapping = filp->f_mapping;
2187 if (!mapping->a_ops->readpage)
2190 file_accessed(filp);
2191 vma->vm_ops = &btrfs_file_vm_ops;
2196 static int hole_mergeable(struct inode *inode, struct extent_buffer *leaf,
2197 int slot, u64 start, u64 end)
2199 struct btrfs_file_extent_item *fi;
2200 struct btrfs_key key;
2202 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2205 btrfs_item_key_to_cpu(leaf, &key, slot);
2206 if (key.objectid != btrfs_ino(inode) ||
2207 key.type != BTRFS_EXTENT_DATA_KEY)
2210 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2212 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2215 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2218 if (key.offset == end)
2220 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2225 static int fill_holes(struct btrfs_trans_handle *trans, struct inode *inode,
2226 struct btrfs_path *path, u64 offset, u64 end)
2228 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2229 struct btrfs_root *root = BTRFS_I(inode)->root;
2230 struct extent_buffer *leaf;
2231 struct btrfs_file_extent_item *fi;
2232 struct extent_map *hole_em;
2233 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2234 struct btrfs_key key;
2237 if (btrfs_fs_incompat(fs_info, NO_HOLES))
2240 key.objectid = btrfs_ino(inode);
2241 key.type = BTRFS_EXTENT_DATA_KEY;
2242 key.offset = offset;
2244 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2247 * We should have dropped this offset, so if we find it then
2248 * something has gone horribly wrong.
2255 leaf = path->nodes[0];
2256 if (hole_mergeable(inode, leaf, path->slots[0]-1, offset, end)) {
2260 fi = btrfs_item_ptr(leaf, path->slots[0],
2261 struct btrfs_file_extent_item);
2262 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2264 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2265 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2266 btrfs_set_file_extent_offset(leaf, fi, 0);
2267 btrfs_mark_buffer_dirty(leaf);
2271 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2274 key.offset = offset;
2275 btrfs_set_item_key_safe(fs_info, path, &key);
2276 fi = btrfs_item_ptr(leaf, path->slots[0],
2277 struct btrfs_file_extent_item);
2278 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2280 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2281 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2282 btrfs_set_file_extent_offset(leaf, fi, 0);
2283 btrfs_mark_buffer_dirty(leaf);
2286 btrfs_release_path(path);
2288 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
2289 0, 0, end - offset, 0, end - offset,
2295 btrfs_release_path(path);
2297 hole_em = alloc_extent_map();
2299 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2300 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2301 &BTRFS_I(inode)->runtime_flags);
2303 hole_em->start = offset;
2304 hole_em->len = end - offset;
2305 hole_em->ram_bytes = hole_em->len;
2306 hole_em->orig_start = offset;
2308 hole_em->block_start = EXTENT_MAP_HOLE;
2309 hole_em->block_len = 0;
2310 hole_em->orig_block_len = 0;
2311 hole_em->bdev = fs_info->fs_devices->latest_bdev;
2312 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2313 hole_em->generation = trans->transid;
2316 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2317 write_lock(&em_tree->lock);
2318 ret = add_extent_mapping(em_tree, hole_em, 1);
2319 write_unlock(&em_tree->lock);
2320 } while (ret == -EEXIST);
2321 free_extent_map(hole_em);
2323 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2324 &BTRFS_I(inode)->runtime_flags);
2331 * Find a hole extent on given inode and change start/len to the end of hole
2332 * extent.(hole/vacuum extent whose em->start <= start &&
2333 * em->start + em->len > start)
2334 * When a hole extent is found, return 1 and modify start/len.
2336 static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)
2338 struct extent_map *em;
2341 em = btrfs_get_extent(inode, NULL, 0, *start, *len, 0);
2342 if (IS_ERR_OR_NULL(em)) {
2350 /* Hole or vacuum extent(only exists in no-hole mode) */
2351 if (em->block_start == EXTENT_MAP_HOLE) {
2353 *len = em->start + em->len > *start + *len ?
2354 0 : *start + *len - em->start - em->len;
2355 *start = em->start + em->len;
2357 free_extent_map(em);
2361 static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2363 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2364 struct btrfs_root *root = BTRFS_I(inode)->root;
2365 struct extent_state *cached_state = NULL;
2366 struct btrfs_path *path;
2367 struct btrfs_block_rsv *rsv;
2368 struct btrfs_trans_handle *trans;
2373 u64 orig_start = offset;
2375 u64 min_size = btrfs_calc_trans_metadata_size(fs_info, 1);
2379 unsigned int rsv_count;
2381 bool no_holes = btrfs_fs_incompat(fs_info, NO_HOLES);
2383 bool truncated_block = false;
2384 bool updated_inode = false;
2386 ret = btrfs_wait_ordered_range(inode, offset, len);
2391 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2392 ret = find_first_non_hole(inode, &offset, &len);
2394 goto out_only_mutex;
2396 /* Already in a large hole */
2398 goto out_only_mutex;
2401 lockstart = round_up(offset, btrfs_inode_sectorsize(inode));
2402 lockend = round_down(offset + len,
2403 btrfs_inode_sectorsize(inode)) - 1;
2404 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset))
2405 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1));
2407 * We needn't truncate any block which is beyond the end of the file
2408 * because we are sure there is no data there.
2411 * Only do this if we are in the same block and we aren't doing the
2414 if (same_block && len < fs_info->sectorsize) {
2415 if (offset < ino_size) {
2416 truncated_block = true;
2417 ret = btrfs_truncate_block(inode, offset, len, 0);
2421 goto out_only_mutex;
2424 /* zero back part of the first block */
2425 if (offset < ino_size) {
2426 truncated_block = true;
2427 ret = btrfs_truncate_block(inode, offset, 0, 0);
2429 inode_unlock(inode);
2434 /* Check the aligned pages after the first unaligned page,
2435 * if offset != orig_start, which means the first unaligned page
2436 * including several following pages are already in holes,
2437 * the extra check can be skipped */
2438 if (offset == orig_start) {
2439 /* after truncate page, check hole again */
2440 len = offset + len - lockstart;
2442 ret = find_first_non_hole(inode, &offset, &len);
2444 goto out_only_mutex;
2447 goto out_only_mutex;
2452 /* Check the tail unaligned part is in a hole */
2453 tail_start = lockend + 1;
2454 tail_len = offset + len - tail_start;
2456 ret = find_first_non_hole(inode, &tail_start, &tail_len);
2457 if (unlikely(ret < 0))
2458 goto out_only_mutex;
2460 /* zero the front end of the last page */
2461 if (tail_start + tail_len < ino_size) {
2462 truncated_block = true;
2463 ret = btrfs_truncate_block(inode,
2464 tail_start + tail_len,
2467 goto out_only_mutex;
2472 if (lockend < lockstart) {
2474 goto out_only_mutex;
2478 struct btrfs_ordered_extent *ordered;
2480 truncate_pagecache_range(inode, lockstart, lockend);
2482 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2484 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2487 * We need to make sure we have no ordered extents in this range
2488 * and nobody raced in and read a page in this range, if we did
2489 * we need to try again.
2492 (ordered->file_offset + ordered->len <= lockstart ||
2493 ordered->file_offset > lockend)) &&
2494 !btrfs_page_exists_in_range(inode, lockstart, lockend)) {
2496 btrfs_put_ordered_extent(ordered);
2500 btrfs_put_ordered_extent(ordered);
2501 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2502 lockend, &cached_state, GFP_NOFS);
2503 ret = btrfs_wait_ordered_range(inode, lockstart,
2504 lockend - lockstart + 1);
2506 inode_unlock(inode);
2511 path = btrfs_alloc_path();
2517 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
2522 rsv->size = btrfs_calc_trans_metadata_size(fs_info, 1);
2526 * 1 - update the inode
2527 * 1 - removing the extents in the range
2528 * 1 - adding the hole extent if no_holes isn't set
2530 rsv_count = no_holes ? 2 : 3;
2531 trans = btrfs_start_transaction(root, rsv_count);
2532 if (IS_ERR(trans)) {
2533 err = PTR_ERR(trans);
2537 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
2540 trans->block_rsv = rsv;
2542 cur_offset = lockstart;
2543 len = lockend - cur_offset;
2544 while (cur_offset < lockend) {
2545 ret = __btrfs_drop_extents(trans, root, inode, path,
2546 cur_offset, lockend + 1,
2547 &drop_end, 1, 0, 0, NULL);
2551 trans->block_rsv = &fs_info->trans_block_rsv;
2553 if (cur_offset < drop_end && cur_offset < ino_size) {
2554 ret = fill_holes(trans, inode, path, cur_offset,
2558 * If we failed then we didn't insert our hole
2559 * entries for the area we dropped, so now the
2560 * fs is corrupted, so we must abort the
2563 btrfs_abort_transaction(trans, ret);
2569 cur_offset = drop_end;
2571 ret = btrfs_update_inode(trans, root, inode);
2577 btrfs_end_transaction(trans);
2578 btrfs_btree_balance_dirty(fs_info);
2580 trans = btrfs_start_transaction(root, rsv_count);
2581 if (IS_ERR(trans)) {
2582 ret = PTR_ERR(trans);
2587 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
2589 BUG_ON(ret); /* shouldn't happen */
2590 trans->block_rsv = rsv;
2592 ret = find_first_non_hole(inode, &cur_offset, &len);
2593 if (unlikely(ret < 0))
2606 trans->block_rsv = &fs_info->trans_block_rsv;
2608 * If we are using the NO_HOLES feature we might have had already an
2609 * hole that overlaps a part of the region [lockstart, lockend] and
2610 * ends at (or beyond) lockend. Since we have no file extent items to
2611 * represent holes, drop_end can be less than lockend and so we must
2612 * make sure we have an extent map representing the existing hole (the
2613 * call to __btrfs_drop_extents() might have dropped the existing extent
2614 * map representing the existing hole), otherwise the fast fsync path
2615 * will not record the existence of the hole region
2616 * [existing_hole_start, lockend].
2618 if (drop_end <= lockend)
2619 drop_end = lockend + 1;
2621 * Don't insert file hole extent item if it's for a range beyond eof
2622 * (because it's useless) or if it represents a 0 bytes range (when
2623 * cur_offset == drop_end).
2625 if (cur_offset < ino_size && cur_offset < drop_end) {
2626 ret = fill_holes(trans, inode, path, cur_offset, drop_end);
2628 /* Same comment as above. */
2629 btrfs_abort_transaction(trans, ret);
2639 inode_inc_iversion(inode);
2640 inode->i_mtime = inode->i_ctime = current_time(inode);
2642 trans->block_rsv = &fs_info->trans_block_rsv;
2643 ret = btrfs_update_inode(trans, root, inode);
2644 updated_inode = true;
2645 btrfs_end_transaction(trans);
2646 btrfs_btree_balance_dirty(fs_info);
2648 btrfs_free_path(path);
2649 btrfs_free_block_rsv(fs_info, rsv);
2651 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2652 &cached_state, GFP_NOFS);
2654 if (!updated_inode && truncated_block && !ret && !err) {
2656 * If we only end up zeroing part of a page, we still need to
2657 * update the inode item, so that all the time fields are
2658 * updated as well as the necessary btrfs inode in memory fields
2659 * for detecting, at fsync time, if the inode isn't yet in the
2660 * log tree or it's there but not up to date.
2662 trans = btrfs_start_transaction(root, 1);
2663 if (IS_ERR(trans)) {
2664 err = PTR_ERR(trans);
2666 err = btrfs_update_inode(trans, root, inode);
2667 ret = btrfs_end_transaction(trans);
2670 inode_unlock(inode);
2676 /* Helper structure to record which range is already reserved */
2677 struct falloc_range {
2678 struct list_head list;
2684 * Helper function to add falloc range
2686 * Caller should have locked the larger range of extent containing
2689 static int add_falloc_range(struct list_head *head, u64 start, u64 len)
2691 struct falloc_range *prev = NULL;
2692 struct falloc_range *range = NULL;
2694 if (list_empty(head))
2698 * As fallocate iterate by bytenr order, we only need to check
2701 prev = list_entry(head->prev, struct falloc_range, list);
2702 if (prev->start + prev->len == start) {
2707 range = kmalloc(sizeof(*range), GFP_KERNEL);
2710 range->start = start;
2712 list_add_tail(&range->list, head);
2716 static long btrfs_fallocate(struct file *file, int mode,
2717 loff_t offset, loff_t len)
2719 struct inode *inode = file_inode(file);
2720 struct extent_state *cached_state = NULL;
2721 struct falloc_range *range;
2722 struct falloc_range *tmp;
2723 struct list_head reserve_list;
2731 struct extent_map *em;
2732 int blocksize = btrfs_inode_sectorsize(inode);
2735 alloc_start = round_down(offset, blocksize);
2736 alloc_end = round_up(offset + len, blocksize);
2737 cur_offset = alloc_start;
2739 /* Make sure we aren't being give some crap mode */
2740 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
2743 if (mode & FALLOC_FL_PUNCH_HOLE)
2744 return btrfs_punch_hole(inode, offset, len);
2747 * Only trigger disk allocation, don't trigger qgroup reserve
2749 * For qgroup space, it will be checked later.
2751 ret = btrfs_alloc_data_chunk_ondemand(inode, alloc_end - alloc_start);
2757 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
2758 ret = inode_newsize_ok(inode, offset + len);
2764 * TODO: Move these two operations after we have checked
2765 * accurate reserved space, or fallocate can still fail but
2766 * with page truncated or size expanded.
2768 * But that's a minor problem and won't do much harm BTW.
2770 if (alloc_start > inode->i_size) {
2771 ret = btrfs_cont_expand(inode, i_size_read(inode),
2775 } else if (offset + len > inode->i_size) {
2777 * If we are fallocating from the end of the file onward we
2778 * need to zero out the end of the block if i_size lands in the
2779 * middle of a block.
2781 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
2787 * wait for ordered IO before we have any locks. We'll loop again
2788 * below with the locks held.
2790 ret = btrfs_wait_ordered_range(inode, alloc_start,
2791 alloc_end - alloc_start);
2795 locked_end = alloc_end - 1;
2797 struct btrfs_ordered_extent *ordered;
2799 /* the extent lock is ordered inside the running
2802 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
2803 locked_end, &cached_state);
2804 ordered = btrfs_lookup_first_ordered_extent(inode,
2807 ordered->file_offset + ordered->len > alloc_start &&
2808 ordered->file_offset < alloc_end) {
2809 btrfs_put_ordered_extent(ordered);
2810 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
2811 alloc_start, locked_end,
2812 &cached_state, GFP_KERNEL);
2814 * we can't wait on the range with the transaction
2815 * running or with the extent lock held
2817 ret = btrfs_wait_ordered_range(inode, alloc_start,
2818 alloc_end - alloc_start);
2823 btrfs_put_ordered_extent(ordered);
2828 /* First, check if we exceed the qgroup limit */
2829 INIT_LIST_HEAD(&reserve_list);
2831 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
2832 alloc_end - cur_offset, 0);
2833 if (IS_ERR_OR_NULL(em)) {
2840 last_byte = min(extent_map_end(em), alloc_end);
2841 actual_end = min_t(u64, extent_map_end(em), offset + len);
2842 last_byte = ALIGN(last_byte, blocksize);
2843 if (em->block_start == EXTENT_MAP_HOLE ||
2844 (cur_offset >= inode->i_size &&
2845 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
2846 ret = add_falloc_range(&reserve_list, cur_offset,
2847 last_byte - cur_offset);
2849 free_extent_map(em);
2852 ret = btrfs_qgroup_reserve_data(inode, cur_offset,
2853 last_byte - cur_offset);
2858 * Do not need to reserve unwritten extent for this
2859 * range, free reserved data space first, otherwise
2860 * it'll result in false ENOSPC error.
2862 btrfs_free_reserved_data_space(inode, cur_offset,
2863 last_byte - cur_offset);
2865 free_extent_map(em);
2866 cur_offset = last_byte;
2867 if (cur_offset >= alloc_end)
2872 * If ret is still 0, means we're OK to fallocate.
2873 * Or just cleanup the list and exit.
2875 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
2877 ret = btrfs_prealloc_file_range(inode, mode,
2879 range->len, 1 << inode->i_blkbits,
2880 offset + len, &alloc_hint);
2882 btrfs_free_reserved_data_space(inode, range->start,
2884 list_del(&range->list);
2890 if (actual_end > inode->i_size &&
2891 !(mode & FALLOC_FL_KEEP_SIZE)) {
2892 struct btrfs_trans_handle *trans;
2893 struct btrfs_root *root = BTRFS_I(inode)->root;
2896 * We didn't need to allocate any more space, but we
2897 * still extended the size of the file so we need to
2898 * update i_size and the inode item.
2900 trans = btrfs_start_transaction(root, 1);
2901 if (IS_ERR(trans)) {
2902 ret = PTR_ERR(trans);
2904 inode->i_ctime = current_time(inode);
2905 i_size_write(inode, actual_end);
2906 btrfs_ordered_update_i_size(inode, actual_end, NULL);
2907 ret = btrfs_update_inode(trans, root, inode);
2909 btrfs_end_transaction(trans);
2911 ret = btrfs_end_transaction(trans);
2915 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
2916 &cached_state, GFP_KERNEL);
2918 inode_unlock(inode);
2919 /* Let go of our reservation. */
2921 btrfs_free_reserved_data_space(inode, alloc_start,
2922 alloc_end - cur_offset);
2926 static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
2928 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2929 struct extent_map *em = NULL;
2930 struct extent_state *cached_state = NULL;
2937 if (inode->i_size == 0)
2941 * *offset can be negative, in this case we start finding DATA/HOLE from
2942 * the very start of the file.
2944 start = max_t(loff_t, 0, *offset);
2946 lockstart = round_down(start, fs_info->sectorsize);
2947 lockend = round_up(i_size_read(inode),
2948 fs_info->sectorsize);
2949 if (lockend <= lockstart)
2950 lockend = lockstart + fs_info->sectorsize;
2952 len = lockend - lockstart + 1;
2954 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2957 while (start < inode->i_size) {
2958 em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
2965 if (whence == SEEK_HOLE &&
2966 (em->block_start == EXTENT_MAP_HOLE ||
2967 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
2969 else if (whence == SEEK_DATA &&
2970 (em->block_start != EXTENT_MAP_HOLE &&
2971 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
2974 start = em->start + em->len;
2975 free_extent_map(em);
2979 free_extent_map(em);
2981 if (whence == SEEK_DATA && start >= inode->i_size)
2984 *offset = min_t(loff_t, start, inode->i_size);
2986 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2987 &cached_state, GFP_NOFS);
2991 static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
2993 struct inode *inode = file->f_mapping->host;
3000 offset = generic_file_llseek(file, offset, whence);
3004 if (offset >= i_size_read(inode)) {
3005 inode_unlock(inode);
3009 ret = find_desired_extent(inode, &offset, whence);
3011 inode_unlock(inode);
3016 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
3018 inode_unlock(inode);
3022 const struct file_operations btrfs_file_operations = {
3023 .llseek = btrfs_file_llseek,
3024 .read_iter = generic_file_read_iter,
3025 .splice_read = generic_file_splice_read,
3026 .write_iter = btrfs_file_write_iter,
3027 .mmap = btrfs_file_mmap,
3028 .open = generic_file_open,
3029 .release = btrfs_release_file,
3030 .fsync = btrfs_sync_file,
3031 .fallocate = btrfs_fallocate,
3032 .unlocked_ioctl = btrfs_ioctl,
3033 #ifdef CONFIG_COMPAT
3034 .compat_ioctl = btrfs_compat_ioctl,
3036 .clone_file_range = btrfs_clone_file_range,
3037 .dedupe_file_range = btrfs_dedupe_file_range,
3040 void btrfs_auto_defrag_exit(void)
3042 kmem_cache_destroy(btrfs_inode_defrag_cachep);
3045 int btrfs_auto_defrag_init(void)
3047 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
3048 sizeof(struct inode_defrag), 0,
3051 if (!btrfs_inode_defrag_cachep)
3057 int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
3062 * So with compression we will find and lock a dirty page and clear the
3063 * first one as dirty, setup an async extent, and immediately return
3064 * with the entire range locked but with nobody actually marked with
3065 * writeback. So we can't just filemap_write_and_wait_range() and
3066 * expect it to work since it will just kick off a thread to do the
3067 * actual work. So we need to call filemap_fdatawrite_range _again_
3068 * since it will wait on the page lock, which won't be unlocked until
3069 * after the pages have been marked as writeback and so we're good to go
3070 * from there. We have to do this otherwise we'll miss the ordered
3071 * extents and that results in badness. Please Josef, do not think you
3072 * know better and pull this out at some point in the future, it is
3073 * right and you are wrong.
3075 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3076 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
3077 &BTRFS_I(inode)->runtime_flags))
3078 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);