2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
20 #include <linux/pagemap.h>
21 #include <linux/highmem.h>
22 #include <linux/time.h>
23 #include <linux/init.h>
24 #include <linux/string.h>
25 #include <linux/backing-dev.h>
26 #include <linux/mpage.h>
27 #include <linux/falloc.h>
28 #include <linux/swap.h>
29 #include <linux/writeback.h>
30 #include <linux/statfs.h>
31 #include <linux/compat.h>
32 #include <linux/slab.h>
33 #include <linux/btrfs.h>
34 #include <linux/uio.h>
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "print-tree.h"
45 static struct kmem_cache *btrfs_inode_defrag_cachep;
47 * when auto defrag is enabled we
48 * queue up these defrag structs to remember which
49 * inodes need defragging passes
52 struct rb_node rb_node;
56 * transid where the defrag was added, we search for
57 * extents newer than this
64 /* last offset we were able to defrag */
67 /* if we've wrapped around back to zero once already */
71 static int __compare_inode_defrag(struct inode_defrag *defrag1,
72 struct inode_defrag *defrag2)
74 if (defrag1->root > defrag2->root)
76 else if (defrag1->root < defrag2->root)
78 else if (defrag1->ino > defrag2->ino)
80 else if (defrag1->ino < defrag2->ino)
86 /* pop a record for an inode into the defrag tree. The lock
87 * must be held already
89 * If you're inserting a record for an older transid than an
90 * existing record, the transid already in the tree is lowered
92 * If an existing record is found the defrag item you
95 static int __btrfs_add_inode_defrag(struct inode *inode,
96 struct inode_defrag *defrag)
98 struct btrfs_root *root = BTRFS_I(inode)->root;
99 struct inode_defrag *entry;
101 struct rb_node *parent = NULL;
104 p = &root->fs_info->defrag_inodes.rb_node;
107 entry = rb_entry(parent, struct inode_defrag, rb_node);
109 ret = __compare_inode_defrag(defrag, entry);
111 p = &parent->rb_left;
113 p = &parent->rb_right;
115 /* if we're reinserting an entry for
116 * an old defrag run, make sure to
117 * lower the transid of our existing record
119 if (defrag->transid < entry->transid)
120 entry->transid = defrag->transid;
121 if (defrag->last_offset > entry->last_offset)
122 entry->last_offset = defrag->last_offset;
126 set_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
127 rb_link_node(&defrag->rb_node, parent, p);
128 rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes);
132 static inline int __need_auto_defrag(struct btrfs_root *root)
134 if (!btrfs_test_opt(root, AUTO_DEFRAG))
137 if (btrfs_fs_closing(root->fs_info))
144 * insert a defrag record for this inode if auto defrag is
147 int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
150 struct btrfs_root *root = BTRFS_I(inode)->root;
151 struct inode_defrag *defrag;
155 if (!__need_auto_defrag(root))
158 if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags))
162 transid = trans->transid;
164 transid = BTRFS_I(inode)->root->last_trans;
166 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
170 defrag->ino = btrfs_ino(inode);
171 defrag->transid = transid;
172 defrag->root = root->root_key.objectid;
174 spin_lock(&root->fs_info->defrag_inodes_lock);
175 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) {
177 * If we set IN_DEFRAG flag and evict the inode from memory,
178 * and then re-read this inode, this new inode doesn't have
179 * IN_DEFRAG flag. At the case, we may find the existed defrag.
181 ret = __btrfs_add_inode_defrag(inode, defrag);
183 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
185 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
187 spin_unlock(&root->fs_info->defrag_inodes_lock);
192 * Requeue the defrag object. If there is a defrag object that points to
193 * the same inode in the tree, we will merge them together (by
194 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
196 static void btrfs_requeue_inode_defrag(struct inode *inode,
197 struct inode_defrag *defrag)
199 struct btrfs_root *root = BTRFS_I(inode)->root;
202 if (!__need_auto_defrag(root))
206 * Here we don't check the IN_DEFRAG flag, because we need merge
209 spin_lock(&root->fs_info->defrag_inodes_lock);
210 ret = __btrfs_add_inode_defrag(inode, defrag);
211 spin_unlock(&root->fs_info->defrag_inodes_lock);
216 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
220 * pick the defragable inode that we want, if it doesn't exist, we will get
223 static struct inode_defrag *
224 btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
226 struct inode_defrag *entry = NULL;
227 struct inode_defrag tmp;
229 struct rb_node *parent = NULL;
235 spin_lock(&fs_info->defrag_inodes_lock);
236 p = fs_info->defrag_inodes.rb_node;
239 entry = rb_entry(parent, struct inode_defrag, rb_node);
241 ret = __compare_inode_defrag(&tmp, entry);
245 p = parent->rb_right;
250 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
251 parent = rb_next(parent);
253 entry = rb_entry(parent, struct inode_defrag, rb_node);
259 rb_erase(parent, &fs_info->defrag_inodes);
260 spin_unlock(&fs_info->defrag_inodes_lock);
264 void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
266 struct inode_defrag *defrag;
267 struct rb_node *node;
269 spin_lock(&fs_info->defrag_inodes_lock);
270 node = rb_first(&fs_info->defrag_inodes);
272 rb_erase(node, &fs_info->defrag_inodes);
273 defrag = rb_entry(node, struct inode_defrag, rb_node);
274 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
276 cond_resched_lock(&fs_info->defrag_inodes_lock);
278 node = rb_first(&fs_info->defrag_inodes);
280 spin_unlock(&fs_info->defrag_inodes_lock);
283 #define BTRFS_DEFRAG_BATCH 1024
285 static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
286 struct inode_defrag *defrag)
288 struct btrfs_root *inode_root;
290 struct btrfs_key key;
291 struct btrfs_ioctl_defrag_range_args range;
297 key.objectid = defrag->root;
298 key.type = BTRFS_ROOT_ITEM_KEY;
299 key.offset = (u64)-1;
301 index = srcu_read_lock(&fs_info->subvol_srcu);
303 inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
304 if (IS_ERR(inode_root)) {
305 ret = PTR_ERR(inode_root);
309 key.objectid = defrag->ino;
310 key.type = BTRFS_INODE_ITEM_KEY;
312 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
314 ret = PTR_ERR(inode);
317 srcu_read_unlock(&fs_info->subvol_srcu, index);
319 /* do a chunk of defrag */
320 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
321 memset(&range, 0, sizeof(range));
323 range.start = defrag->last_offset;
325 sb_start_write(fs_info->sb);
326 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
328 sb_end_write(fs_info->sb);
330 * if we filled the whole defrag batch, there
331 * must be more work to do. Queue this defrag
334 if (num_defrag == BTRFS_DEFRAG_BATCH) {
335 defrag->last_offset = range.start;
336 btrfs_requeue_inode_defrag(inode, defrag);
337 } else if (defrag->last_offset && !defrag->cycled) {
339 * we didn't fill our defrag batch, but
340 * we didn't start at zero. Make sure we loop
341 * around to the start of the file.
343 defrag->last_offset = 0;
345 btrfs_requeue_inode_defrag(inode, defrag);
347 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
353 srcu_read_unlock(&fs_info->subvol_srcu, index);
354 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
359 * run through the list of inodes in the FS that need
362 int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
364 struct inode_defrag *defrag;
366 u64 root_objectid = 0;
368 atomic_inc(&fs_info->defrag_running);
370 /* Pause the auto defragger. */
371 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
375 if (!__need_auto_defrag(fs_info->tree_root))
378 /* find an inode to defrag */
379 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
382 if (root_objectid || first_ino) {
391 first_ino = defrag->ino + 1;
392 root_objectid = defrag->root;
394 __btrfs_run_defrag_inode(fs_info, defrag);
396 atomic_dec(&fs_info->defrag_running);
399 * during unmount, we use the transaction_wait queue to
400 * wait for the defragger to stop
402 wake_up(&fs_info->transaction_wait);
406 /* simple helper to fault in pages and copy. This should go away
407 * and be replaced with calls into generic code.
409 static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
411 struct page **prepared_pages,
415 size_t total_copied = 0;
417 int offset = pos & (PAGE_CACHE_SIZE - 1);
419 while (write_bytes > 0) {
420 size_t count = min_t(size_t,
421 PAGE_CACHE_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_CACHE_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]);
476 page_cache_release(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 btrfs_root *root, struct inode *inode,
489 struct page **pages, size_t num_pages,
490 loff_t pos, size_t write_bytes,
491 struct extent_state **cached)
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)root->sectorsize - 1);
502 num_bytes = ALIGN(write_bytes + pos - start_pos, root->sectorsize);
504 end_of_last_block = start_pos + num_bytes - 1;
505 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
510 for (i = 0; i < num_pages; i++) {
511 struct page *p = pages[i];
518 * we've only changed i_size in ram, and we haven't updated
519 * the disk i_size. There is no need to log the inode
523 i_size_write(inode, end_pos);
528 * this drops all the extents in the cache that intersect the range
529 * [start, end]. Existing extents are split as required.
531 void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
534 struct extent_map *em;
535 struct extent_map *split = NULL;
536 struct extent_map *split2 = NULL;
537 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
538 u64 len = end - start + 1;
546 WARN_ON(end < start);
547 if (end == (u64)-1) {
556 split = alloc_extent_map();
558 split2 = alloc_extent_map();
559 if (!split || !split2)
562 write_lock(&em_tree->lock);
563 em = lookup_extent_mapping(em_tree, start, len);
565 write_unlock(&em_tree->lock);
569 gen = em->generation;
570 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
571 if (testend && em->start + em->len >= start + len) {
573 write_unlock(&em_tree->lock);
576 start = em->start + em->len;
578 len = start + len - (em->start + em->len);
580 write_unlock(&em_tree->lock);
583 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
584 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
585 clear_bit(EXTENT_FLAG_LOGGING, &flags);
586 modified = !list_empty(&em->list);
590 if (em->start < start) {
591 split->start = em->start;
592 split->len = start - em->start;
594 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
595 split->orig_start = em->orig_start;
596 split->block_start = em->block_start;
599 split->block_len = em->block_len;
601 split->block_len = split->len;
602 split->orig_block_len = max(split->block_len,
604 split->ram_bytes = em->ram_bytes;
606 split->orig_start = split->start;
607 split->block_len = 0;
608 split->block_start = em->block_start;
609 split->orig_block_len = 0;
610 split->ram_bytes = split->len;
613 split->generation = gen;
614 split->bdev = em->bdev;
615 split->flags = flags;
616 split->compress_type = em->compress_type;
617 replace_extent_mapping(em_tree, em, split, modified);
618 free_extent_map(split);
622 if (testend && em->start + em->len > start + len) {
623 u64 diff = start + len - em->start;
625 split->start = start + len;
626 split->len = em->start + em->len - (start + len);
627 split->bdev = em->bdev;
628 split->flags = flags;
629 split->compress_type = em->compress_type;
630 split->generation = gen;
632 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
633 split->orig_block_len = max(em->block_len,
636 split->ram_bytes = em->ram_bytes;
638 split->block_len = em->block_len;
639 split->block_start = em->block_start;
640 split->orig_start = em->orig_start;
642 split->block_len = split->len;
643 split->block_start = em->block_start
645 split->orig_start = em->orig_start;
648 split->ram_bytes = split->len;
649 split->orig_start = split->start;
650 split->block_len = 0;
651 split->block_start = em->block_start;
652 split->orig_block_len = 0;
655 if (extent_map_in_tree(em)) {
656 replace_extent_mapping(em_tree, em, split,
659 ret = add_extent_mapping(em_tree, split,
661 ASSERT(ret == 0); /* Logic error */
663 free_extent_map(split);
667 if (extent_map_in_tree(em))
668 remove_extent_mapping(em_tree, em);
669 write_unlock(&em_tree->lock);
673 /* once for the tree*/
677 free_extent_map(split);
679 free_extent_map(split2);
683 * this is very complex, but the basic idea is to drop all extents
684 * in the range start - end. hint_block is filled in with a block number
685 * that would be a good hint to the block allocator for this file.
687 * If an extent intersects the range but is not entirely inside the range
688 * it is either truncated or split. Anything entirely inside the range
689 * is deleted from the tree.
691 int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
692 struct btrfs_root *root, struct inode *inode,
693 struct btrfs_path *path, u64 start, u64 end,
694 u64 *drop_end, int drop_cache,
696 u32 extent_item_size,
699 struct extent_buffer *leaf;
700 struct btrfs_file_extent_item *fi;
701 struct btrfs_key key;
702 struct btrfs_key new_key;
703 u64 ino = btrfs_ino(inode);
704 u64 search_start = start;
707 u64 extent_offset = 0;
714 int modify_tree = -1;
717 int leafs_visited = 0;
720 btrfs_drop_extent_cache(inode, start, end - 1, 0);
722 if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent)
725 update_refs = (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
726 root == root->fs_info->tree_root);
729 ret = btrfs_lookup_file_extent(trans, root, path, ino,
730 search_start, modify_tree);
733 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
734 leaf = path->nodes[0];
735 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
736 if (key.objectid == ino &&
737 key.type == BTRFS_EXTENT_DATA_KEY)
743 leaf = path->nodes[0];
744 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
746 ret = btrfs_next_leaf(root, path);
754 leaf = path->nodes[0];
758 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
759 if (key.objectid > ino ||
760 key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
763 fi = btrfs_item_ptr(leaf, path->slots[0],
764 struct btrfs_file_extent_item);
765 extent_type = btrfs_file_extent_type(leaf, fi);
767 if (extent_type == BTRFS_FILE_EXTENT_REG ||
768 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
769 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
770 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
771 extent_offset = btrfs_file_extent_offset(leaf, fi);
772 extent_end = key.offset +
773 btrfs_file_extent_num_bytes(leaf, fi);
774 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
775 extent_end = key.offset +
776 btrfs_file_extent_inline_len(leaf,
780 extent_end = search_start;
784 * Don't skip extent items representing 0 byte lengths. They
785 * used to be created (bug) if while punching holes we hit
786 * -ENOSPC condition. So if we find one here, just ensure we
787 * delete it, otherwise we would insert a new file extent item
788 * with the same key (offset) as that 0 bytes length file
789 * extent item in the call to setup_items_for_insert() later
792 if (extent_end == key.offset && extent_end >= search_start)
793 goto delete_extent_item;
795 if (extent_end <= search_start) {
801 search_start = max(key.offset, start);
802 if (recow || !modify_tree) {
804 btrfs_release_path(path);
809 * | - range to drop - |
810 * | -------- extent -------- |
812 if (start > key.offset && end < extent_end) {
814 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
819 memcpy(&new_key, &key, sizeof(new_key));
820 new_key.offset = start;
821 ret = btrfs_duplicate_item(trans, root, path,
823 if (ret == -EAGAIN) {
824 btrfs_release_path(path);
830 leaf = path->nodes[0];
831 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
832 struct btrfs_file_extent_item);
833 btrfs_set_file_extent_num_bytes(leaf, fi,
836 fi = btrfs_item_ptr(leaf, path->slots[0],
837 struct btrfs_file_extent_item);
839 extent_offset += start - key.offset;
840 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
841 btrfs_set_file_extent_num_bytes(leaf, fi,
843 btrfs_mark_buffer_dirty(leaf);
845 if (update_refs && disk_bytenr > 0) {
846 ret = btrfs_inc_extent_ref(trans, root,
847 disk_bytenr, num_bytes, 0,
848 root->root_key.objectid,
850 start - extent_offset, 1);
851 BUG_ON(ret); /* -ENOMEM */
856 * | ---- range to drop ----- |
857 * | -------- extent -------- |
859 if (start <= key.offset && end < extent_end) {
860 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
865 memcpy(&new_key, &key, sizeof(new_key));
866 new_key.offset = end;
867 btrfs_set_item_key_safe(root->fs_info, path, &new_key);
869 extent_offset += end - key.offset;
870 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
871 btrfs_set_file_extent_num_bytes(leaf, fi,
873 btrfs_mark_buffer_dirty(leaf);
874 if (update_refs && disk_bytenr > 0)
875 inode_sub_bytes(inode, end - key.offset);
879 search_start = extent_end;
881 * | ---- range to drop ----- |
882 * | -------- extent -------- |
884 if (start > key.offset && end >= extent_end) {
886 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
891 btrfs_set_file_extent_num_bytes(leaf, fi,
893 btrfs_mark_buffer_dirty(leaf);
894 if (update_refs && disk_bytenr > 0)
895 inode_sub_bytes(inode, extent_end - start);
896 if (end == extent_end)
904 * | ---- range to drop ----- |
905 * | ------ extent ------ |
907 if (start <= key.offset && end >= extent_end) {
910 del_slot = path->slots[0];
913 BUG_ON(del_slot + del_nr != path->slots[0]);
918 extent_type == BTRFS_FILE_EXTENT_INLINE) {
919 inode_sub_bytes(inode,
920 extent_end - key.offset);
921 extent_end = ALIGN(extent_end,
923 } else if (update_refs && disk_bytenr > 0) {
924 ret = btrfs_free_extent(trans, root,
925 disk_bytenr, num_bytes, 0,
926 root->root_key.objectid,
927 key.objectid, key.offset -
929 BUG_ON(ret); /* -ENOMEM */
930 inode_sub_bytes(inode,
931 extent_end - key.offset);
934 if (end == extent_end)
937 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
942 ret = btrfs_del_items(trans, root, path, del_slot,
945 btrfs_abort_transaction(trans, root, ret);
952 btrfs_release_path(path);
959 if (!ret && del_nr > 0) {
961 * Set path->slots[0] to first slot, so that after the delete
962 * if items are move off from our leaf to its immediate left or
963 * right neighbor leafs, we end up with a correct and adjusted
964 * path->slots[0] for our insertion (if replace_extent != 0).
966 path->slots[0] = del_slot;
967 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
969 btrfs_abort_transaction(trans, root, ret);
972 leaf = path->nodes[0];
974 * If btrfs_del_items() was called, it might have deleted a leaf, in
975 * which case it unlocked our path, so check path->locks[0] matches a
978 if (!ret && replace_extent && leafs_visited == 1 &&
979 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
980 path->locks[0] == BTRFS_WRITE_LOCK) &&
981 btrfs_leaf_free_space(root, leaf) >=
982 sizeof(struct btrfs_item) + extent_item_size) {
985 key.type = BTRFS_EXTENT_DATA_KEY;
987 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
988 struct btrfs_key slot_key;
990 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
991 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
994 setup_items_for_insert(root, path, &key,
997 sizeof(struct btrfs_item) +
998 extent_item_size, 1);
1002 if (!replace_extent || !(*key_inserted))
1003 btrfs_release_path(path);
1005 *drop_end = found ? min(end, extent_end) : end;
1009 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
1010 struct btrfs_root *root, struct inode *inode, u64 start,
1011 u64 end, int drop_cache)
1013 struct btrfs_path *path;
1016 path = btrfs_alloc_path();
1019 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
1020 drop_cache, 0, 0, NULL);
1021 btrfs_free_path(path);
1025 static int extent_mergeable(struct extent_buffer *leaf, int slot,
1026 u64 objectid, u64 bytenr, u64 orig_offset,
1027 u64 *start, u64 *end)
1029 struct btrfs_file_extent_item *fi;
1030 struct btrfs_key key;
1033 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1036 btrfs_item_key_to_cpu(leaf, &key, slot);
1037 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1040 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1041 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1042 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1043 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1044 btrfs_file_extent_compression(leaf, fi) ||
1045 btrfs_file_extent_encryption(leaf, fi) ||
1046 btrfs_file_extent_other_encoding(leaf, fi))
1049 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1050 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1053 *start = key.offset;
1059 * Mark extent in the range start - end as written.
1061 * This changes extent type from 'pre-allocated' to 'regular'. If only
1062 * part of extent is marked as written, the extent will be split into
1065 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1066 struct inode *inode, u64 start, u64 end)
1068 struct btrfs_root *root = BTRFS_I(inode)->root;
1069 struct extent_buffer *leaf;
1070 struct btrfs_path *path;
1071 struct btrfs_file_extent_item *fi;
1072 struct btrfs_key key;
1073 struct btrfs_key new_key;
1085 u64 ino = btrfs_ino(inode);
1087 path = btrfs_alloc_path();
1094 key.type = BTRFS_EXTENT_DATA_KEY;
1097 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1100 if (ret > 0 && path->slots[0] > 0)
1103 leaf = path->nodes[0];
1104 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1105 BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY);
1106 fi = btrfs_item_ptr(leaf, path->slots[0],
1107 struct btrfs_file_extent_item);
1108 BUG_ON(btrfs_file_extent_type(leaf, fi) !=
1109 BTRFS_FILE_EXTENT_PREALLOC);
1110 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1111 BUG_ON(key.offset > start || extent_end < end);
1113 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1114 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1115 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1116 memcpy(&new_key, &key, sizeof(new_key));
1118 if (start == key.offset && end < extent_end) {
1121 if (extent_mergeable(leaf, path->slots[0] - 1,
1122 ino, bytenr, orig_offset,
1123 &other_start, &other_end)) {
1124 new_key.offset = end;
1125 btrfs_set_item_key_safe(root->fs_info, path, &new_key);
1126 fi = btrfs_item_ptr(leaf, path->slots[0],
1127 struct btrfs_file_extent_item);
1128 btrfs_set_file_extent_generation(leaf, fi,
1130 btrfs_set_file_extent_num_bytes(leaf, fi,
1132 btrfs_set_file_extent_offset(leaf, fi,
1134 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1135 struct btrfs_file_extent_item);
1136 btrfs_set_file_extent_generation(leaf, fi,
1138 btrfs_set_file_extent_num_bytes(leaf, fi,
1140 btrfs_mark_buffer_dirty(leaf);
1145 if (start > key.offset && end == extent_end) {
1148 if (extent_mergeable(leaf, path->slots[0] + 1,
1149 ino, bytenr, orig_offset,
1150 &other_start, &other_end)) {
1151 fi = btrfs_item_ptr(leaf, path->slots[0],
1152 struct btrfs_file_extent_item);
1153 btrfs_set_file_extent_num_bytes(leaf, fi,
1154 start - key.offset);
1155 btrfs_set_file_extent_generation(leaf, fi,
1158 new_key.offset = start;
1159 btrfs_set_item_key_safe(root->fs_info, path, &new_key);
1161 fi = btrfs_item_ptr(leaf, path->slots[0],
1162 struct btrfs_file_extent_item);
1163 btrfs_set_file_extent_generation(leaf, fi,
1165 btrfs_set_file_extent_num_bytes(leaf, fi,
1167 btrfs_set_file_extent_offset(leaf, fi,
1168 start - orig_offset);
1169 btrfs_mark_buffer_dirty(leaf);
1174 while (start > key.offset || end < extent_end) {
1175 if (key.offset == start)
1178 new_key.offset = split;
1179 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1180 if (ret == -EAGAIN) {
1181 btrfs_release_path(path);
1185 btrfs_abort_transaction(trans, root, ret);
1189 leaf = path->nodes[0];
1190 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1191 struct btrfs_file_extent_item);
1192 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1193 btrfs_set_file_extent_num_bytes(leaf, fi,
1194 split - key.offset);
1196 fi = btrfs_item_ptr(leaf, path->slots[0],
1197 struct btrfs_file_extent_item);
1199 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1200 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1201 btrfs_set_file_extent_num_bytes(leaf, fi,
1202 extent_end - split);
1203 btrfs_mark_buffer_dirty(leaf);
1205 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
1206 root->root_key.objectid,
1207 ino, orig_offset, 1);
1208 BUG_ON(ret); /* -ENOMEM */
1210 if (split == start) {
1213 BUG_ON(start != key.offset);
1222 if (extent_mergeable(leaf, path->slots[0] + 1,
1223 ino, bytenr, orig_offset,
1224 &other_start, &other_end)) {
1226 btrfs_release_path(path);
1229 extent_end = other_end;
1230 del_slot = path->slots[0] + 1;
1232 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1233 0, root->root_key.objectid,
1234 ino, orig_offset, 0);
1235 BUG_ON(ret); /* -ENOMEM */
1239 if (extent_mergeable(leaf, path->slots[0] - 1,
1240 ino, bytenr, orig_offset,
1241 &other_start, &other_end)) {
1243 btrfs_release_path(path);
1246 key.offset = other_start;
1247 del_slot = path->slots[0];
1249 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1250 0, root->root_key.objectid,
1251 ino, orig_offset, 0);
1252 BUG_ON(ret); /* -ENOMEM */
1255 fi = btrfs_item_ptr(leaf, path->slots[0],
1256 struct btrfs_file_extent_item);
1257 btrfs_set_file_extent_type(leaf, fi,
1258 BTRFS_FILE_EXTENT_REG);
1259 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1260 btrfs_mark_buffer_dirty(leaf);
1262 fi = btrfs_item_ptr(leaf, del_slot - 1,
1263 struct btrfs_file_extent_item);
1264 btrfs_set_file_extent_type(leaf, fi,
1265 BTRFS_FILE_EXTENT_REG);
1266 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1267 btrfs_set_file_extent_num_bytes(leaf, fi,
1268 extent_end - key.offset);
1269 btrfs_mark_buffer_dirty(leaf);
1271 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1273 btrfs_abort_transaction(trans, root, ret);
1278 btrfs_free_path(path);
1283 * on error we return an unlocked page and the error value
1284 * on success we return a locked page and 0
1286 static int prepare_uptodate_page(struct page *page, u64 pos,
1287 bool force_uptodate)
1291 if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
1292 !PageUptodate(page)) {
1293 ret = btrfs_readpage(NULL, page);
1297 if (!PageUptodate(page)) {
1306 * this just gets pages into the page cache and locks them down.
1308 static noinline int prepare_pages(struct inode *inode, struct page **pages,
1309 size_t num_pages, loff_t pos,
1310 size_t write_bytes, bool force_uptodate)
1313 unsigned long index = pos >> PAGE_CACHE_SHIFT;
1314 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1318 for (i = 0; i < num_pages; i++) {
1319 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1320 mask | __GFP_WRITE);
1328 err = prepare_uptodate_page(pages[i], pos,
1330 if (i == num_pages - 1)
1331 err = prepare_uptodate_page(pages[i],
1332 pos + write_bytes, false);
1334 page_cache_release(pages[i]);
1338 wait_on_page_writeback(pages[i]);
1343 while (faili >= 0) {
1344 unlock_page(pages[faili]);
1345 page_cache_release(pages[faili]);
1353 * This function locks the extent and properly waits for data=ordered extents
1354 * to finish before allowing the pages to be modified if need.
1357 * 1 - the extent is locked
1358 * 0 - the extent is not locked, and everything is OK
1359 * -EAGAIN - need re-prepare the pages
1360 * the other < 0 number - Something wrong happens
1363 lock_and_cleanup_extent_if_need(struct inode *inode, struct page **pages,
1364 size_t num_pages, loff_t pos,
1365 u64 *lockstart, u64 *lockend,
1366 struct extent_state **cached_state)
1373 start_pos = pos & ~((u64)PAGE_CACHE_SIZE - 1);
1374 last_pos = start_pos + ((u64)num_pages << PAGE_CACHE_SHIFT) - 1;
1376 if (start_pos < inode->i_size) {
1377 struct btrfs_ordered_extent *ordered;
1378 lock_extent_bits(&BTRFS_I(inode)->io_tree,
1379 start_pos, last_pos, 0, cached_state);
1380 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1381 last_pos - start_pos + 1);
1383 ordered->file_offset + ordered->len > start_pos &&
1384 ordered->file_offset <= last_pos) {
1385 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1386 start_pos, last_pos,
1387 cached_state, GFP_NOFS);
1388 for (i = 0; i < num_pages; i++) {
1389 unlock_page(pages[i]);
1390 page_cache_release(pages[i]);
1392 btrfs_start_ordered_extent(inode, ordered, 1);
1393 btrfs_put_ordered_extent(ordered);
1397 btrfs_put_ordered_extent(ordered);
1399 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
1400 last_pos, EXTENT_DIRTY | EXTENT_DELALLOC |
1401 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
1402 0, 0, cached_state, GFP_NOFS);
1403 *lockstart = start_pos;
1404 *lockend = last_pos;
1408 for (i = 0; i < num_pages; i++) {
1409 if (clear_page_dirty_for_io(pages[i]))
1410 account_page_redirty(pages[i]);
1411 set_page_extent_mapped(pages[i]);
1412 WARN_ON(!PageLocked(pages[i]));
1418 static noinline int check_can_nocow(struct inode *inode, loff_t pos,
1419 size_t *write_bytes)
1421 struct btrfs_root *root = BTRFS_I(inode)->root;
1422 struct btrfs_ordered_extent *ordered;
1423 u64 lockstart, lockend;
1427 ret = btrfs_start_write_no_snapshoting(root);
1431 lockstart = round_down(pos, root->sectorsize);
1432 lockend = round_up(pos + *write_bytes, root->sectorsize) - 1;
1435 lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1436 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1437 lockend - lockstart + 1);
1441 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1442 btrfs_start_ordered_extent(inode, ordered, 1);
1443 btrfs_put_ordered_extent(ordered);
1446 num_bytes = lockend - lockstart + 1;
1447 ret = can_nocow_extent(inode, lockstart, &num_bytes, NULL, NULL, NULL);
1450 btrfs_end_write_no_snapshoting(root);
1452 *write_bytes = min_t(size_t, *write_bytes ,
1453 num_bytes - pos + lockstart);
1456 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1461 static noinline ssize_t __btrfs_buffered_write(struct file *file,
1465 struct inode *inode = file_inode(file);
1466 struct btrfs_root *root = BTRFS_I(inode)->root;
1467 struct page **pages = NULL;
1468 struct extent_state *cached_state = NULL;
1469 u64 release_bytes = 0;
1472 size_t num_written = 0;
1475 bool only_release_metadata = false;
1476 bool force_page_uptodate = false;
1479 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_CACHE_SIZE),
1480 PAGE_CACHE_SIZE / (sizeof(struct page *)));
1481 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1482 nrptrs = max(nrptrs, 8);
1483 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1487 while (iov_iter_count(i) > 0) {
1488 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
1489 size_t write_bytes = min(iov_iter_count(i),
1490 nrptrs * (size_t)PAGE_CACHE_SIZE -
1492 size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
1494 size_t reserve_bytes;
1498 WARN_ON(num_pages > nrptrs);
1501 * Fault pages before locking them in prepare_pages
1502 * to avoid recursive lock
1504 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1509 reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
1511 if (BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1512 BTRFS_INODE_PREALLOC)) {
1513 ret = check_can_nocow(inode, pos, &write_bytes);
1518 * For nodata cow case, no need to reserve
1521 only_release_metadata = true;
1523 * our prealloc extent may be smaller than
1524 * write_bytes, so scale down.
1526 num_pages = DIV_ROUND_UP(write_bytes + offset,
1528 reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
1529 goto reserve_metadata;
1532 ret = __btrfs_check_data_free_space(inode, pos, write_bytes);
1537 ret = btrfs_delalloc_reserve_metadata(inode, reserve_bytes);
1539 if (!only_release_metadata)
1540 __btrfs_free_reserved_data_space(inode, pos,
1543 btrfs_end_write_no_snapshoting(root);
1547 release_bytes = reserve_bytes;
1548 need_unlock = false;
1551 * This is going to setup the pages array with the number of
1552 * pages we want, so we don't really need to worry about the
1553 * contents of pages from loop to loop
1555 ret = prepare_pages(inode, pages, num_pages,
1557 force_page_uptodate);
1561 ret = lock_and_cleanup_extent_if_need(inode, pages, num_pages,
1562 pos, &lockstart, &lockend,
1568 } else if (ret > 0) {
1573 copied = btrfs_copy_from_user(pos, num_pages,
1574 write_bytes, pages, i);
1577 * if we have trouble faulting in the pages, fall
1578 * back to one page at a time
1580 if (copied < write_bytes)
1584 force_page_uptodate = true;
1587 force_page_uptodate = false;
1588 dirty_pages = DIV_ROUND_UP(copied + offset,
1593 * If we had a short copy we need to release the excess delaloc
1594 * bytes we reserved. We need to increment outstanding_extents
1595 * because btrfs_delalloc_release_space will decrement it, but
1596 * we still have an outstanding extent for the chunk we actually
1599 if (num_pages > dirty_pages) {
1600 release_bytes = (num_pages - dirty_pages) <<
1603 spin_lock(&BTRFS_I(inode)->lock);
1604 BTRFS_I(inode)->outstanding_extents++;
1605 spin_unlock(&BTRFS_I(inode)->lock);
1607 if (only_release_metadata)
1608 btrfs_delalloc_release_metadata(inode,
1611 __btrfs_delalloc_release_space(inode, pos,
1615 release_bytes = dirty_pages << PAGE_CACHE_SHIFT;
1618 ret = btrfs_dirty_pages(root, inode, pages,
1619 dirty_pages, pos, copied,
1622 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1623 lockstart, lockend, &cached_state,
1626 btrfs_drop_pages(pages, num_pages);
1631 if (only_release_metadata)
1632 btrfs_end_write_no_snapshoting(root);
1634 if (only_release_metadata && copied > 0) {
1635 lockstart = round_down(pos, root->sectorsize);
1636 lockend = lockstart +
1637 (dirty_pages << PAGE_CACHE_SHIFT) - 1;
1639 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1640 lockend, EXTENT_NORESERVE, NULL,
1642 only_release_metadata = false;
1645 btrfs_drop_pages(pages, num_pages);
1649 balance_dirty_pages_ratelimited(inode->i_mapping);
1650 if (dirty_pages < (root->nodesize >> PAGE_CACHE_SHIFT) + 1)
1651 btrfs_btree_balance_dirty(root);
1654 num_written += copied;
1659 if (release_bytes) {
1660 if (only_release_metadata) {
1661 btrfs_end_write_no_snapshoting(root);
1662 btrfs_delalloc_release_metadata(inode, release_bytes);
1664 __btrfs_delalloc_release_space(inode, pos,
1669 return num_written ? num_written : ret;
1672 static ssize_t __btrfs_direct_write(struct kiocb *iocb,
1673 struct iov_iter *from,
1676 struct file *file = iocb->ki_filp;
1677 struct inode *inode = file_inode(file);
1679 ssize_t written_buffered;
1683 written = generic_file_direct_write(iocb, from, pos);
1685 if (written < 0 || !iov_iter_count(from))
1689 written_buffered = __btrfs_buffered_write(file, from, pos);
1690 if (written_buffered < 0) {
1691 err = written_buffered;
1695 * Ensure all data is persisted. We want the next direct IO read to be
1696 * able to read what was just written.
1698 endbyte = pos + written_buffered - 1;
1699 err = btrfs_fdatawrite_range(inode, pos, endbyte);
1702 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
1705 written += written_buffered;
1706 iocb->ki_pos = pos + written_buffered;
1707 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,
1708 endbyte >> PAGE_CACHE_SHIFT);
1710 return written ? written : err;
1713 static void update_time_for_write(struct inode *inode)
1715 struct timespec now;
1717 if (IS_NOCMTIME(inode))
1720 now = current_fs_time(inode->i_sb);
1721 if (!timespec_equal(&inode->i_mtime, &now))
1722 inode->i_mtime = now;
1724 if (!timespec_equal(&inode->i_ctime, &now))
1725 inode->i_ctime = now;
1727 if (IS_I_VERSION(inode))
1728 inode_inc_iversion(inode);
1731 static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1732 struct iov_iter *from)
1734 struct file *file = iocb->ki_filp;
1735 struct inode *inode = file_inode(file);
1736 struct btrfs_root *root = BTRFS_I(inode)->root;
1739 ssize_t num_written = 0;
1740 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
1745 mutex_lock(&inode->i_mutex);
1746 err = generic_write_checks(iocb, from);
1748 mutex_unlock(&inode->i_mutex);
1752 current->backing_dev_info = inode_to_bdi(inode);
1753 err = file_remove_privs(file);
1755 mutex_unlock(&inode->i_mutex);
1760 * If BTRFS flips readonly due to some impossible error
1761 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1762 * although we have opened a file as writable, we have
1763 * to stop this write operation to ensure FS consistency.
1765 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1766 mutex_unlock(&inode->i_mutex);
1772 * We reserve space for updating the inode when we reserve space for the
1773 * extent we are going to write, so we will enospc out there. We don't
1774 * need to start yet another transaction to update the inode as we will
1775 * update the inode when we finish writing whatever data we write.
1777 update_time_for_write(inode);
1780 count = iov_iter_count(from);
1781 start_pos = round_down(pos, root->sectorsize);
1782 if (start_pos > i_size_read(inode)) {
1783 /* Expand hole size to cover write data, preventing empty gap */
1784 end_pos = round_up(pos + count, root->sectorsize);
1785 err = btrfs_cont_expand(inode, i_size_read(inode), end_pos);
1787 mutex_unlock(&inode->i_mutex);
1793 atomic_inc(&BTRFS_I(inode)->sync_writers);
1795 if (iocb->ki_flags & IOCB_DIRECT) {
1796 num_written = __btrfs_direct_write(iocb, from, pos);
1798 num_written = __btrfs_buffered_write(file, from, pos);
1799 if (num_written > 0)
1800 iocb->ki_pos = pos + num_written;
1803 mutex_unlock(&inode->i_mutex);
1806 * We also have to set last_sub_trans to the current log transid,
1807 * otherwise subsequent syncs to a file that's been synced in this
1808 * transaction will appear to have already occured.
1810 spin_lock(&BTRFS_I(inode)->lock);
1811 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1812 spin_unlock(&BTRFS_I(inode)->lock);
1813 if (num_written > 0) {
1814 err = generic_write_sync(file, pos, num_written);
1820 atomic_dec(&BTRFS_I(inode)->sync_writers);
1822 current->backing_dev_info = NULL;
1823 return num_written ? num_written : err;
1826 int btrfs_release_file(struct inode *inode, struct file *filp)
1828 if (filp->private_data)
1829 btrfs_ioctl_trans_end(filp);
1831 * ordered_data_close is set by settattr when we are about to truncate
1832 * a file from a non-zero size to a zero size. This tries to
1833 * flush down new bytes that may have been written if the
1834 * application were using truncate to replace a file in place.
1836 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
1837 &BTRFS_I(inode)->runtime_flags))
1838 filemap_flush(inode->i_mapping);
1842 static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
1846 atomic_inc(&BTRFS_I(inode)->sync_writers);
1847 ret = btrfs_fdatawrite_range(inode, start, end);
1848 atomic_dec(&BTRFS_I(inode)->sync_writers);
1854 * fsync call for both files and directories. This logs the inode into
1855 * the tree log instead of forcing full commits whenever possible.
1857 * It needs to call filemap_fdatawait so that all ordered extent updates are
1858 * in the metadata btree are up to date for copying to the log.
1860 * It drops the inode mutex before doing the tree log commit. This is an
1861 * important optimization for directories because holding the mutex prevents
1862 * new operations on the dir while we write to disk.
1864 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
1866 struct dentry *dentry = file->f_path.dentry;
1867 struct inode *inode = d_inode(dentry);
1868 struct btrfs_root *root = BTRFS_I(inode)->root;
1869 struct btrfs_trans_handle *trans;
1870 struct btrfs_log_ctx ctx;
1873 const u64 len = end - start + 1;
1875 trace_btrfs_sync_file(file, datasync);
1878 * We write the dirty pages in the range and wait until they complete
1879 * out of the ->i_mutex. If so, we can flush the dirty pages by
1880 * multi-task, and make the performance up. See
1881 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
1883 ret = start_ordered_ops(inode, start, end);
1887 mutex_lock(&inode->i_mutex);
1888 atomic_inc(&root->log_batch);
1889 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1890 &BTRFS_I(inode)->runtime_flags);
1892 * We might have have had more pages made dirty after calling
1893 * start_ordered_ops and before acquiring the inode's i_mutex.
1897 * For a full sync, we need to make sure any ordered operations
1898 * start and finish before we start logging the inode, so that
1899 * all extents are persisted and the respective file extent
1900 * items are in the fs/subvol btree.
1902 ret = btrfs_wait_ordered_range(inode, start, len);
1905 * Start any new ordered operations before starting to log the
1906 * inode. We will wait for them to finish in btrfs_sync_log().
1908 * Right before acquiring the inode's mutex, we might have new
1909 * writes dirtying pages, which won't immediately start the
1910 * respective ordered operations - that is done through the
1911 * fill_delalloc callbacks invoked from the writepage and
1912 * writepages address space operations. So make sure we start
1913 * all ordered operations before starting to log our inode. Not
1914 * doing this means that while logging the inode, writeback
1915 * could start and invoke writepage/writepages, which would call
1916 * the fill_delalloc callbacks (cow_file_range,
1917 * submit_compressed_extents). These callbacks add first an
1918 * extent map to the modified list of extents and then create
1919 * the respective ordered operation, which means in
1920 * tree-log.c:btrfs_log_inode() we might capture all existing
1921 * ordered operations (with btrfs_get_logged_extents()) before
1922 * the fill_delalloc callback adds its ordered operation, and by
1923 * the time we visit the modified list of extent maps (with
1924 * btrfs_log_changed_extents()), we see and process the extent
1925 * map they created. We then use the extent map to construct a
1926 * file extent item for logging without waiting for the
1927 * respective ordered operation to finish - this file extent
1928 * item points to a disk location that might not have yet been
1929 * written to, containing random data - so after a crash a log
1930 * replay will make our inode have file extent items that point
1931 * to disk locations containing invalid data, as we returned
1932 * success to userspace without waiting for the respective
1933 * ordered operation to finish, because it wasn't captured by
1934 * btrfs_get_logged_extents().
1936 ret = start_ordered_ops(inode, start, end);
1939 mutex_unlock(&inode->i_mutex);
1942 atomic_inc(&root->log_batch);
1945 * If the last transaction that changed this file was before the current
1946 * transaction and we have the full sync flag set in our inode, we can
1947 * bail out now without any syncing.
1949 * Note that we can't bail out if the full sync flag isn't set. This is
1950 * because when the full sync flag is set we start all ordered extents
1951 * and wait for them to fully complete - when they complete they update
1952 * the inode's last_trans field through:
1954 * btrfs_finish_ordered_io() ->
1955 * btrfs_update_inode_fallback() ->
1956 * btrfs_update_inode() ->
1957 * btrfs_set_inode_last_trans()
1959 * So we are sure that last_trans is up to date and can do this check to
1960 * bail out safely. For the fast path, when the full sync flag is not
1961 * set in our inode, we can not do it because we start only our ordered
1962 * extents and don't wait for them to complete (that is when
1963 * btrfs_finish_ordered_io runs), so here at this point their last_trans
1964 * value might be less than or equals to fs_info->last_trans_committed,
1965 * and setting a speculative last_trans for an inode when a buffered
1966 * write is made (such as fs_info->generation + 1 for example) would not
1967 * be reliable since after setting the value and before fsync is called
1968 * any number of transactions can start and commit (transaction kthread
1969 * commits the current transaction periodically), and a transaction
1970 * commit does not start nor waits for ordered extents to complete.
1973 if (btrfs_inode_in_log(inode, root->fs_info->generation) ||
1974 (BTRFS_I(inode)->last_trans <=
1975 root->fs_info->last_trans_committed &&
1977 !btrfs_have_ordered_extents_in_range(inode, start, len)))) {
1979 * We'v had everything committed since the last time we were
1980 * modified so clear this flag in case it was set for whatever
1981 * reason, it's no longer relevant.
1983 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1984 &BTRFS_I(inode)->runtime_flags);
1985 mutex_unlock(&inode->i_mutex);
1990 * ok we haven't committed the transaction yet, lets do a commit
1992 if (file->private_data)
1993 btrfs_ioctl_trans_end(file);
1996 * We use start here because we will need to wait on the IO to complete
1997 * in btrfs_sync_log, which could require joining a transaction (for
1998 * example checking cross references in the nocow path). If we use join
1999 * here we could get into a situation where we're waiting on IO to
2000 * happen that is blocked on a transaction trying to commit. With start
2001 * we inc the extwriter counter, so we wait for all extwriters to exit
2002 * before we start blocking join'ers. This comment is to keep somebody
2003 * from thinking they are super smart and changing this to
2004 * btrfs_join_transaction *cough*Josef*cough*.
2006 trans = btrfs_start_transaction(root, 0);
2007 if (IS_ERR(trans)) {
2008 ret = PTR_ERR(trans);
2009 mutex_unlock(&inode->i_mutex);
2014 btrfs_init_log_ctx(&ctx);
2016 ret = btrfs_log_dentry_safe(trans, root, dentry, start, end, &ctx);
2018 /* Fallthrough and commit/free transaction. */
2022 /* we've logged all the items and now have a consistent
2023 * version of the file in the log. It is possible that
2024 * someone will come in and modify the file, but that's
2025 * fine because the log is consistent on disk, and we
2026 * have references to all of the file's extents
2028 * It is possible that someone will come in and log the
2029 * file again, but that will end up using the synchronization
2030 * inside btrfs_sync_log to keep things safe.
2032 mutex_unlock(&inode->i_mutex);
2035 * If any of the ordered extents had an error, just return it to user
2036 * space, so that the application knows some writes didn't succeed and
2037 * can take proper action (retry for e.g.). Blindly committing the
2038 * transaction in this case, would fool userspace that everything was
2039 * successful. And we also want to make sure our log doesn't contain
2040 * file extent items pointing to extents that weren't fully written to -
2041 * just like in the non fast fsync path, where we check for the ordered
2042 * operation's error flag before writing to the log tree and return -EIO
2043 * if any of them had this flag set (btrfs_wait_ordered_range) -
2044 * therefore we need to check for errors in the ordered operations,
2045 * which are indicated by ctx.io_err.
2048 btrfs_end_transaction(trans, root);
2053 if (ret != BTRFS_NO_LOG_SYNC) {
2055 ret = btrfs_sync_log(trans, root, &ctx);
2057 ret = btrfs_end_transaction(trans, root);
2062 ret = btrfs_wait_ordered_range(inode, start,
2065 btrfs_end_transaction(trans, root);
2069 ret = btrfs_commit_transaction(trans, root);
2071 ret = btrfs_end_transaction(trans, root);
2074 return ret > 0 ? -EIO : ret;
2077 static const struct vm_operations_struct btrfs_file_vm_ops = {
2078 .fault = filemap_fault,
2079 .map_pages = filemap_map_pages,
2080 .page_mkwrite = btrfs_page_mkwrite,
2083 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2085 struct address_space *mapping = filp->f_mapping;
2087 if (!mapping->a_ops->readpage)
2090 file_accessed(filp);
2091 vma->vm_ops = &btrfs_file_vm_ops;
2096 static int hole_mergeable(struct inode *inode, struct extent_buffer *leaf,
2097 int slot, u64 start, u64 end)
2099 struct btrfs_file_extent_item *fi;
2100 struct btrfs_key key;
2102 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2105 btrfs_item_key_to_cpu(leaf, &key, slot);
2106 if (key.objectid != btrfs_ino(inode) ||
2107 key.type != BTRFS_EXTENT_DATA_KEY)
2110 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2112 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2115 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2118 if (key.offset == end)
2120 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2125 static int fill_holes(struct btrfs_trans_handle *trans, struct inode *inode,
2126 struct btrfs_path *path, u64 offset, u64 end)
2128 struct btrfs_root *root = BTRFS_I(inode)->root;
2129 struct extent_buffer *leaf;
2130 struct btrfs_file_extent_item *fi;
2131 struct extent_map *hole_em;
2132 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2133 struct btrfs_key key;
2136 if (btrfs_fs_incompat(root->fs_info, NO_HOLES))
2139 key.objectid = btrfs_ino(inode);
2140 key.type = BTRFS_EXTENT_DATA_KEY;
2141 key.offset = offset;
2143 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2148 leaf = path->nodes[0];
2149 if (hole_mergeable(inode, leaf, path->slots[0]-1, offset, end)) {
2153 fi = btrfs_item_ptr(leaf, path->slots[0],
2154 struct btrfs_file_extent_item);
2155 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2157 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2158 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2159 btrfs_set_file_extent_offset(leaf, fi, 0);
2160 btrfs_mark_buffer_dirty(leaf);
2164 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2167 key.offset = offset;
2168 btrfs_set_item_key_safe(root->fs_info, path, &key);
2169 fi = btrfs_item_ptr(leaf, path->slots[0],
2170 struct btrfs_file_extent_item);
2171 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2173 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2174 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2175 btrfs_set_file_extent_offset(leaf, fi, 0);
2176 btrfs_mark_buffer_dirty(leaf);
2179 btrfs_release_path(path);
2181 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
2182 0, 0, end - offset, 0, end - offset,
2188 btrfs_release_path(path);
2190 hole_em = alloc_extent_map();
2192 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2193 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2194 &BTRFS_I(inode)->runtime_flags);
2196 hole_em->start = offset;
2197 hole_em->len = end - offset;
2198 hole_em->ram_bytes = hole_em->len;
2199 hole_em->orig_start = offset;
2201 hole_em->block_start = EXTENT_MAP_HOLE;
2202 hole_em->block_len = 0;
2203 hole_em->orig_block_len = 0;
2204 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
2205 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2206 hole_em->generation = trans->transid;
2209 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2210 write_lock(&em_tree->lock);
2211 ret = add_extent_mapping(em_tree, hole_em, 1);
2212 write_unlock(&em_tree->lock);
2213 } while (ret == -EEXIST);
2214 free_extent_map(hole_em);
2216 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2217 &BTRFS_I(inode)->runtime_flags);
2224 * Find a hole extent on given inode and change start/len to the end of hole
2225 * extent.(hole/vacuum extent whose em->start <= start &&
2226 * em->start + em->len > start)
2227 * When a hole extent is found, return 1 and modify start/len.
2229 static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)
2231 struct extent_map *em;
2234 em = btrfs_get_extent(inode, NULL, 0, *start, *len, 0);
2235 if (IS_ERR_OR_NULL(em)) {
2243 /* Hole or vacuum extent(only exists in no-hole mode) */
2244 if (em->block_start == EXTENT_MAP_HOLE) {
2246 *len = em->start + em->len > *start + *len ?
2247 0 : *start + *len - em->start - em->len;
2248 *start = em->start + em->len;
2250 free_extent_map(em);
2254 static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2256 struct btrfs_root *root = BTRFS_I(inode)->root;
2257 struct extent_state *cached_state = NULL;
2258 struct btrfs_path *path;
2259 struct btrfs_block_rsv *rsv;
2260 struct btrfs_trans_handle *trans;
2265 u64 orig_start = offset;
2267 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
2271 unsigned int rsv_count;
2273 bool no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES);
2275 bool truncated_page = false;
2276 bool updated_inode = false;
2278 ret = btrfs_wait_ordered_range(inode, offset, len);
2282 mutex_lock(&inode->i_mutex);
2283 ino_size = round_up(inode->i_size, PAGE_CACHE_SIZE);
2284 ret = find_first_non_hole(inode, &offset, &len);
2286 goto out_only_mutex;
2288 /* Already in a large hole */
2290 goto out_only_mutex;
2293 lockstart = round_up(offset, BTRFS_I(inode)->root->sectorsize);
2294 lockend = round_down(offset + len,
2295 BTRFS_I(inode)->root->sectorsize) - 1;
2296 same_page = ((offset >> PAGE_CACHE_SHIFT) ==
2297 ((offset + len - 1) >> PAGE_CACHE_SHIFT));
2300 * We needn't truncate any page which is beyond the end of the file
2301 * because we are sure there is no data there.
2304 * Only do this if we are in the same page and we aren't doing the
2307 if (same_page && len < PAGE_CACHE_SIZE) {
2308 if (offset < ino_size) {
2309 truncated_page = true;
2310 ret = btrfs_truncate_page(inode, offset, len, 0);
2314 goto out_only_mutex;
2317 /* zero back part of the first page */
2318 if (offset < ino_size) {
2319 truncated_page = true;
2320 ret = btrfs_truncate_page(inode, offset, 0, 0);
2322 mutex_unlock(&inode->i_mutex);
2327 /* Check the aligned pages after the first unaligned page,
2328 * if offset != orig_start, which means the first unaligned page
2329 * including serveral following pages are already in holes,
2330 * the extra check can be skipped */
2331 if (offset == orig_start) {
2332 /* after truncate page, check hole again */
2333 len = offset + len - lockstart;
2335 ret = find_first_non_hole(inode, &offset, &len);
2337 goto out_only_mutex;
2340 goto out_only_mutex;
2345 /* Check the tail unaligned part is in a hole */
2346 tail_start = lockend + 1;
2347 tail_len = offset + len - tail_start;
2349 ret = find_first_non_hole(inode, &tail_start, &tail_len);
2350 if (unlikely(ret < 0))
2351 goto out_only_mutex;
2353 /* zero the front end of the last page */
2354 if (tail_start + tail_len < ino_size) {
2355 truncated_page = true;
2356 ret = btrfs_truncate_page(inode,
2357 tail_start + tail_len, 0, 1);
2359 goto out_only_mutex;
2364 if (lockend < lockstart) {
2366 goto out_only_mutex;
2370 struct btrfs_ordered_extent *ordered;
2372 truncate_pagecache_range(inode, lockstart, lockend);
2374 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2376 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2379 * We need to make sure we have no ordered extents in this range
2380 * and nobody raced in and read a page in this range, if we did
2381 * we need to try again.
2384 (ordered->file_offset + ordered->len <= lockstart ||
2385 ordered->file_offset > lockend)) &&
2386 !btrfs_page_exists_in_range(inode, lockstart, lockend)) {
2388 btrfs_put_ordered_extent(ordered);
2392 btrfs_put_ordered_extent(ordered);
2393 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2394 lockend, &cached_state, GFP_NOFS);
2395 ret = btrfs_wait_ordered_range(inode, lockstart,
2396 lockend - lockstart + 1);
2398 mutex_unlock(&inode->i_mutex);
2403 path = btrfs_alloc_path();
2409 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2414 rsv->size = btrfs_calc_trunc_metadata_size(root, 1);
2418 * 1 - update the inode
2419 * 1 - removing the extents in the range
2420 * 1 - adding the hole extent if no_holes isn't set
2422 rsv_count = no_holes ? 2 : 3;
2423 trans = btrfs_start_transaction(root, rsv_count);
2424 if (IS_ERR(trans)) {
2425 err = PTR_ERR(trans);
2429 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
2432 trans->block_rsv = rsv;
2434 cur_offset = lockstart;
2435 len = lockend - cur_offset;
2436 while (cur_offset < lockend) {
2437 ret = __btrfs_drop_extents(trans, root, inode, path,
2438 cur_offset, lockend + 1,
2439 &drop_end, 1, 0, 0, NULL);
2443 trans->block_rsv = &root->fs_info->trans_block_rsv;
2445 if (cur_offset < ino_size) {
2446 ret = fill_holes(trans, inode, path, cur_offset,
2454 cur_offset = drop_end;
2456 ret = btrfs_update_inode(trans, root, inode);
2462 btrfs_end_transaction(trans, root);
2463 btrfs_btree_balance_dirty(root);
2465 trans = btrfs_start_transaction(root, rsv_count);
2466 if (IS_ERR(trans)) {
2467 ret = PTR_ERR(trans);
2472 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
2474 BUG_ON(ret); /* shouldn't happen */
2475 trans->block_rsv = rsv;
2477 ret = find_first_non_hole(inode, &cur_offset, &len);
2478 if (unlikely(ret < 0))
2491 trans->block_rsv = &root->fs_info->trans_block_rsv;
2493 * Don't insert file hole extent item if it's for a range beyond eof
2494 * (because it's useless) or if it represents a 0 bytes range (when
2495 * cur_offset == drop_end).
2497 if (cur_offset < ino_size && cur_offset < drop_end) {
2498 ret = fill_holes(trans, inode, path, cur_offset, drop_end);
2509 inode_inc_iversion(inode);
2510 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2512 trans->block_rsv = &root->fs_info->trans_block_rsv;
2513 ret = btrfs_update_inode(trans, root, inode);
2514 updated_inode = true;
2515 btrfs_end_transaction(trans, root);
2516 btrfs_btree_balance_dirty(root);
2518 btrfs_free_path(path);
2519 btrfs_free_block_rsv(root, rsv);
2521 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2522 &cached_state, GFP_NOFS);
2524 if (!updated_inode && truncated_page && !ret && !err) {
2526 * If we only end up zeroing part of a page, we still need to
2527 * update the inode item, so that all the time fields are
2528 * updated as well as the necessary btrfs inode in memory fields
2529 * for detecting, at fsync time, if the inode isn't yet in the
2530 * log tree or it's there but not up to date.
2532 trans = btrfs_start_transaction(root, 1);
2533 if (IS_ERR(trans)) {
2534 err = PTR_ERR(trans);
2536 err = btrfs_update_inode(trans, root, inode);
2537 ret = btrfs_end_transaction(trans, root);
2540 mutex_unlock(&inode->i_mutex);
2546 static long btrfs_fallocate(struct file *file, int mode,
2547 loff_t offset, loff_t len)
2549 struct inode *inode = file_inode(file);
2550 struct extent_state *cached_state = NULL;
2557 struct extent_map *em;
2558 int blocksize = BTRFS_I(inode)->root->sectorsize;
2561 alloc_start = round_down(offset, blocksize);
2562 alloc_end = round_up(offset + len, blocksize);
2564 /* Make sure we aren't being give some crap mode */
2565 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
2568 if (mode & FALLOC_FL_PUNCH_HOLE)
2569 return btrfs_punch_hole(inode, offset, len);
2572 * Make sure we have enough space before we do the
2574 * XXX: The behavior must be changed to do accurate check first
2575 * and then check data reserved space.
2577 ret = btrfs_check_data_free_space(inode, alloc_start,
2578 alloc_end - alloc_start);
2582 mutex_lock(&inode->i_mutex);
2583 ret = inode_newsize_ok(inode, alloc_end);
2587 if (alloc_start > inode->i_size) {
2588 ret = btrfs_cont_expand(inode, i_size_read(inode),
2594 * If we are fallocating from the end of the file onward we
2595 * need to zero out the end of the page if i_size lands in the
2598 ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
2604 * wait for ordered IO before we have any locks. We'll loop again
2605 * below with the locks held.
2607 ret = btrfs_wait_ordered_range(inode, alloc_start,
2608 alloc_end - alloc_start);
2612 locked_end = alloc_end - 1;
2614 struct btrfs_ordered_extent *ordered;
2616 /* the extent lock is ordered inside the running
2619 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
2620 locked_end, 0, &cached_state);
2621 ordered = btrfs_lookup_first_ordered_extent(inode,
2624 ordered->file_offset + ordered->len > alloc_start &&
2625 ordered->file_offset < alloc_end) {
2626 btrfs_put_ordered_extent(ordered);
2627 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
2628 alloc_start, locked_end,
2629 &cached_state, GFP_NOFS);
2631 * we can't wait on the range with the transaction
2632 * running or with the extent lock held
2634 ret = btrfs_wait_ordered_range(inode, alloc_start,
2635 alloc_end - alloc_start);
2640 btrfs_put_ordered_extent(ordered);
2645 cur_offset = alloc_start;
2649 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
2650 alloc_end - cur_offset, 0);
2651 if (IS_ERR_OR_NULL(em)) {
2658 last_byte = min(extent_map_end(em), alloc_end);
2659 actual_end = min_t(u64, extent_map_end(em), offset + len);
2660 last_byte = ALIGN(last_byte, blocksize);
2662 if (em->block_start == EXTENT_MAP_HOLE ||
2663 (cur_offset >= inode->i_size &&
2664 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
2665 ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
2666 last_byte - cur_offset,
2667 1 << inode->i_blkbits,
2670 } else if (actual_end > inode->i_size &&
2671 !(mode & FALLOC_FL_KEEP_SIZE)) {
2672 struct btrfs_trans_handle *trans;
2673 struct btrfs_root *root = BTRFS_I(inode)->root;
2676 * We didn't need to allocate any more space, but we
2677 * still extended the size of the file so we need to
2678 * update i_size and the inode item.
2680 trans = btrfs_start_transaction(root, 1);
2681 if (IS_ERR(trans)) {
2682 ret = PTR_ERR(trans);
2684 inode->i_ctime = CURRENT_TIME;
2685 i_size_write(inode, actual_end);
2686 btrfs_ordered_update_i_size(inode, actual_end,
2688 ret = btrfs_update_inode(trans, root, inode);
2690 btrfs_end_transaction(trans, root);
2692 ret = btrfs_end_transaction(trans,
2696 free_extent_map(em);
2700 cur_offset = last_byte;
2701 if (cur_offset >= alloc_end) {
2706 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
2707 &cached_state, GFP_NOFS);
2709 mutex_unlock(&inode->i_mutex);
2710 /* Let go of our reservation. */
2711 __btrfs_free_reserved_data_space(inode, alloc_start,
2712 alloc_end - alloc_start);
2716 static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
2718 struct btrfs_root *root = BTRFS_I(inode)->root;
2719 struct extent_map *em = NULL;
2720 struct extent_state *cached_state = NULL;
2727 if (inode->i_size == 0)
2731 * *offset can be negative, in this case we start finding DATA/HOLE from
2732 * the very start of the file.
2734 start = max_t(loff_t, 0, *offset);
2736 lockstart = round_down(start, root->sectorsize);
2737 lockend = round_up(i_size_read(inode), root->sectorsize);
2738 if (lockend <= lockstart)
2739 lockend = lockstart + root->sectorsize;
2741 len = lockend - lockstart + 1;
2743 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0,
2746 while (start < inode->i_size) {
2747 em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
2754 if (whence == SEEK_HOLE &&
2755 (em->block_start == EXTENT_MAP_HOLE ||
2756 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
2758 else if (whence == SEEK_DATA &&
2759 (em->block_start != EXTENT_MAP_HOLE &&
2760 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
2763 start = em->start + em->len;
2764 free_extent_map(em);
2768 free_extent_map(em);
2770 if (whence == SEEK_DATA && start >= inode->i_size)
2773 *offset = min_t(loff_t, start, inode->i_size);
2775 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2776 &cached_state, GFP_NOFS);
2780 static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
2782 struct inode *inode = file->f_mapping->host;
2785 mutex_lock(&inode->i_mutex);
2789 offset = generic_file_llseek(file, offset, whence);
2793 if (offset >= i_size_read(inode)) {
2794 mutex_unlock(&inode->i_mutex);
2798 ret = find_desired_extent(inode, &offset, whence);
2800 mutex_unlock(&inode->i_mutex);
2805 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
2807 mutex_unlock(&inode->i_mutex);
2811 const struct file_operations btrfs_file_operations = {
2812 .llseek = btrfs_file_llseek,
2813 .read_iter = generic_file_read_iter,
2814 .splice_read = generic_file_splice_read,
2815 .write_iter = btrfs_file_write_iter,
2816 .mmap = btrfs_file_mmap,
2817 .open = generic_file_open,
2818 .release = btrfs_release_file,
2819 .fsync = btrfs_sync_file,
2820 .fallocate = btrfs_fallocate,
2821 .unlocked_ioctl = btrfs_ioctl,
2822 #ifdef CONFIG_COMPAT
2823 .compat_ioctl = btrfs_ioctl,
2827 void btrfs_auto_defrag_exit(void)
2829 if (btrfs_inode_defrag_cachep)
2830 kmem_cache_destroy(btrfs_inode_defrag_cachep);
2833 int btrfs_auto_defrag_init(void)
2835 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
2836 sizeof(struct inode_defrag), 0,
2837 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
2839 if (!btrfs_inode_defrag_cachep)
2845 int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
2850 * So with compression we will find and lock a dirty page and clear the
2851 * first one as dirty, setup an async extent, and immediately return
2852 * with the entire range locked but with nobody actually marked with
2853 * writeback. So we can't just filemap_write_and_wait_range() and
2854 * expect it to work since it will just kick off a thread to do the
2855 * actual work. So we need to call filemap_fdatawrite_range _again_
2856 * since it will wait on the page lock, which won't be unlocked until
2857 * after the pages have been marked as writeback and so we're good to go
2858 * from there. We have to do this otherwise we'll miss the ordered
2859 * extents and that results in badness. Please Josef, do not think you
2860 * know better and pull this out at some point in the future, it is
2861 * right and you are wrong.
2863 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
2864 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
2865 &BTRFS_I(inode)->runtime_flags))
2866 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);