2 * Copyright (C) 2007 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
20 #include <linux/pagemap.h>
21 #include <linux/highmem.h>
22 #include <linux/time.h>
23 #include <linux/init.h>
24 #include <linux/string.h>
25 #include <linux/backing-dev.h>
26 #include <linux/mpage.h>
27 #include <linux/aio.h>
28 #include <linux/falloc.h>
29 #include <linux/swap.h>
30 #include <linux/writeback.h>
31 #include <linux/statfs.h>
32 #include <linux/compat.h>
33 #include <linux/slab.h>
34 #include <linux/btrfs.h>
37 #include "transaction.h"
38 #include "btrfs_inode.h"
39 #include "print-tree.h"
45 static struct kmem_cache *btrfs_inode_defrag_cachep;
47 * when auto defrag is enabled we
48 * queue up these defrag structs to remember which
49 * inodes need defragging passes
52 struct rb_node rb_node;
56 * transid where the defrag was added, we search for
57 * extents newer than this
64 /* last offset we were able to defrag */
67 /* if we've wrapped around back to zero once already */
71 static int __compare_inode_defrag(struct inode_defrag *defrag1,
72 struct inode_defrag *defrag2)
74 if (defrag1->root > defrag2->root)
76 else if (defrag1->root < defrag2->root)
78 else if (defrag1->ino > defrag2->ino)
80 else if (defrag1->ino < defrag2->ino)
86 /* pop a record for an inode into the defrag tree. The lock
87 * must be held already
89 * If you're inserting a record for an older transid than an
90 * existing record, the transid already in the tree is lowered
92 * If an existing record is found the defrag item you
95 static int __btrfs_add_inode_defrag(struct inode *inode,
96 struct inode_defrag *defrag)
98 struct btrfs_root *root = BTRFS_I(inode)->root;
99 struct inode_defrag *entry;
101 struct rb_node *parent = NULL;
104 p = &root->fs_info->defrag_inodes.rb_node;
107 entry = rb_entry(parent, struct inode_defrag, rb_node);
109 ret = __compare_inode_defrag(defrag, entry);
111 p = &parent->rb_left;
113 p = &parent->rb_right;
115 /* if we're reinserting an entry for
116 * an old defrag run, make sure to
117 * lower the transid of our existing record
119 if (defrag->transid < entry->transid)
120 entry->transid = defrag->transid;
121 if (defrag->last_offset > entry->last_offset)
122 entry->last_offset = defrag->last_offset;
126 set_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
127 rb_link_node(&defrag->rb_node, parent, p);
128 rb_insert_color(&defrag->rb_node, &root->fs_info->defrag_inodes);
132 static inline int __need_auto_defrag(struct btrfs_root *root)
134 if (!btrfs_test_opt(root, AUTO_DEFRAG))
137 if (btrfs_fs_closing(root->fs_info))
144 * insert a defrag record for this inode if auto defrag is
147 int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
150 struct btrfs_root *root = BTRFS_I(inode)->root;
151 struct inode_defrag *defrag;
155 if (!__need_auto_defrag(root))
158 if (test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags))
162 transid = trans->transid;
164 transid = BTRFS_I(inode)->root->last_trans;
166 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
170 defrag->ino = btrfs_ino(inode);
171 defrag->transid = transid;
172 defrag->root = root->root_key.objectid;
174 spin_lock(&root->fs_info->defrag_inodes_lock);
175 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags)) {
177 * If we set IN_DEFRAG flag and evict the inode from memory,
178 * and then re-read this inode, this new inode doesn't have
179 * IN_DEFRAG flag. At the case, we may find the existed defrag.
181 ret = __btrfs_add_inode_defrag(inode, defrag);
183 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
185 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
187 spin_unlock(&root->fs_info->defrag_inodes_lock);
192 * Requeue the defrag object. If there is a defrag object that points to
193 * the same inode in the tree, we will merge them together (by
194 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
196 static void btrfs_requeue_inode_defrag(struct inode *inode,
197 struct inode_defrag *defrag)
199 struct btrfs_root *root = BTRFS_I(inode)->root;
202 if (!__need_auto_defrag(root))
206 * Here we don't check the IN_DEFRAG flag, because we need merge
209 spin_lock(&root->fs_info->defrag_inodes_lock);
210 ret = __btrfs_add_inode_defrag(inode, defrag);
211 spin_unlock(&root->fs_info->defrag_inodes_lock);
216 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
220 * pick the defragable inode that we want, if it doesn't exist, we will get
223 static struct inode_defrag *
224 btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
226 struct inode_defrag *entry = NULL;
227 struct inode_defrag tmp;
229 struct rb_node *parent = NULL;
235 spin_lock(&fs_info->defrag_inodes_lock);
236 p = fs_info->defrag_inodes.rb_node;
239 entry = rb_entry(parent, struct inode_defrag, rb_node);
241 ret = __compare_inode_defrag(&tmp, entry);
245 p = parent->rb_right;
250 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
251 parent = rb_next(parent);
253 entry = rb_entry(parent, struct inode_defrag, rb_node);
259 rb_erase(parent, &fs_info->defrag_inodes);
260 spin_unlock(&fs_info->defrag_inodes_lock);
264 void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
266 struct inode_defrag *defrag;
267 struct rb_node *node;
269 spin_lock(&fs_info->defrag_inodes_lock);
270 node = rb_first(&fs_info->defrag_inodes);
272 rb_erase(node, &fs_info->defrag_inodes);
273 defrag = rb_entry(node, struct inode_defrag, rb_node);
274 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
276 if (need_resched()) {
277 spin_unlock(&fs_info->defrag_inodes_lock);
279 spin_lock(&fs_info->defrag_inodes_lock);
282 node = rb_first(&fs_info->defrag_inodes);
284 spin_unlock(&fs_info->defrag_inodes_lock);
287 #define BTRFS_DEFRAG_BATCH 1024
289 static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
290 struct inode_defrag *defrag)
292 struct btrfs_root *inode_root;
294 struct btrfs_key key;
295 struct btrfs_ioctl_defrag_range_args range;
301 key.objectid = defrag->root;
302 btrfs_set_key_type(&key, BTRFS_ROOT_ITEM_KEY);
303 key.offset = (u64)-1;
305 index = srcu_read_lock(&fs_info->subvol_srcu);
307 inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
308 if (IS_ERR(inode_root)) {
309 ret = PTR_ERR(inode_root);
313 key.objectid = defrag->ino;
314 btrfs_set_key_type(&key, BTRFS_INODE_ITEM_KEY);
316 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
318 ret = PTR_ERR(inode);
321 srcu_read_unlock(&fs_info->subvol_srcu, index);
323 /* do a chunk of defrag */
324 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
325 memset(&range, 0, sizeof(range));
327 range.start = defrag->last_offset;
329 sb_start_write(fs_info->sb);
330 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
332 sb_end_write(fs_info->sb);
334 * if we filled the whole defrag batch, there
335 * must be more work to do. Queue this defrag
338 if (num_defrag == BTRFS_DEFRAG_BATCH) {
339 defrag->last_offset = range.start;
340 btrfs_requeue_inode_defrag(inode, defrag);
341 } else if (defrag->last_offset && !defrag->cycled) {
343 * we didn't fill our defrag batch, but
344 * we didn't start at zero. Make sure we loop
345 * around to the start of the file.
347 defrag->last_offset = 0;
349 btrfs_requeue_inode_defrag(inode, defrag);
351 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
357 srcu_read_unlock(&fs_info->subvol_srcu, index);
358 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
363 * run through the list of inodes in the FS that need
366 int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
368 struct inode_defrag *defrag;
370 u64 root_objectid = 0;
372 atomic_inc(&fs_info->defrag_running);
374 /* Pause the auto defragger. */
375 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
379 if (!__need_auto_defrag(fs_info->tree_root))
382 /* find an inode to defrag */
383 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
386 if (root_objectid || first_ino) {
395 first_ino = defrag->ino + 1;
396 root_objectid = defrag->root;
398 __btrfs_run_defrag_inode(fs_info, defrag);
400 atomic_dec(&fs_info->defrag_running);
403 * during unmount, we use the transaction_wait queue to
404 * wait for the defragger to stop
406 wake_up(&fs_info->transaction_wait);
410 /* simple helper to fault in pages and copy. This should go away
411 * and be replaced with calls into generic code.
413 static noinline int btrfs_copy_from_user(loff_t pos, int num_pages,
415 struct page **prepared_pages,
419 size_t total_copied = 0;
421 int offset = pos & (PAGE_CACHE_SIZE - 1);
423 while (write_bytes > 0) {
424 size_t count = min_t(size_t,
425 PAGE_CACHE_SIZE - offset, write_bytes);
426 struct page *page = prepared_pages[pg];
428 * Copy data from userspace to the current page
430 * Disable pagefault to avoid recursive lock since
431 * the pages are already locked
434 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
437 /* Flush processor's dcache for this page */
438 flush_dcache_page(page);
441 * if we get a partial write, we can end up with
442 * partially up to date pages. These add
443 * a lot of complexity, so make sure they don't
444 * happen by forcing this copy to be retried.
446 * The rest of the btrfs_file_write code will fall
447 * back to page at a time copies after we return 0.
449 if (!PageUptodate(page) && copied < count)
452 iov_iter_advance(i, copied);
453 write_bytes -= copied;
454 total_copied += copied;
456 /* Return to btrfs_file_aio_write to fault page */
457 if (unlikely(copied == 0))
460 if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
471 * unlocks pages after btrfs_file_write is done with them
473 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
476 for (i = 0; i < num_pages; i++) {
477 /* page checked is some magic around finding pages that
478 * have been modified without going through btrfs_set_page_dirty
481 ClearPageChecked(pages[i]);
482 unlock_page(pages[i]);
483 mark_page_accessed(pages[i]);
484 page_cache_release(pages[i]);
489 * after copy_from_user, pages need to be dirtied and we need to make
490 * sure holes are created between the current EOF and the start of
491 * any next extents (if required).
493 * this also makes the decision about creating an inline extent vs
494 * doing real data extents, marking pages dirty and delalloc as required.
496 int btrfs_dirty_pages(struct btrfs_root *root, struct inode *inode,
497 struct page **pages, size_t num_pages,
498 loff_t pos, size_t write_bytes,
499 struct extent_state **cached)
505 u64 end_of_last_block;
506 u64 end_pos = pos + write_bytes;
507 loff_t isize = i_size_read(inode);
509 start_pos = pos & ~((u64)root->sectorsize - 1);
510 num_bytes = ALIGN(write_bytes + pos - start_pos, root->sectorsize);
512 end_of_last_block = start_pos + num_bytes - 1;
513 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
518 for (i = 0; i < num_pages; i++) {
519 struct page *p = pages[i];
526 * we've only changed i_size in ram, and we haven't updated
527 * the disk i_size. There is no need to log the inode
531 i_size_write(inode, end_pos);
536 * this drops all the extents in the cache that intersect the range
537 * [start, end]. Existing extents are split as required.
539 void btrfs_drop_extent_cache(struct inode *inode, u64 start, u64 end,
542 struct extent_map *em;
543 struct extent_map *split = NULL;
544 struct extent_map *split2 = NULL;
545 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
546 u64 len = end - start + 1;
554 WARN_ON(end < start);
555 if (end == (u64)-1) {
564 split = alloc_extent_map();
566 split2 = alloc_extent_map();
567 if (!split || !split2)
570 write_lock(&em_tree->lock);
571 em = lookup_extent_mapping(em_tree, start, len);
573 write_unlock(&em_tree->lock);
577 gen = em->generation;
578 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
579 if (testend && em->start + em->len >= start + len) {
581 write_unlock(&em_tree->lock);
584 start = em->start + em->len;
586 len = start + len - (em->start + em->len);
588 write_unlock(&em_tree->lock);
591 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
592 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
593 clear_bit(EXTENT_FLAG_LOGGING, &flags);
594 modified = !list_empty(&em->list);
595 remove_extent_mapping(em_tree, em);
599 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
601 split->start = em->start;
602 split->len = start - em->start;
603 split->orig_start = em->orig_start;
604 split->block_start = em->block_start;
607 split->block_len = em->block_len;
609 split->block_len = split->len;
610 split->ram_bytes = em->ram_bytes;
611 split->orig_block_len = max(split->block_len,
613 split->generation = gen;
614 split->bdev = em->bdev;
615 split->flags = flags;
616 split->compress_type = em->compress_type;
617 ret = add_extent_mapping(em_tree, split, modified);
618 BUG_ON(ret); /* Logic error */
619 free_extent_map(split);
623 if (em->block_start < EXTENT_MAP_LAST_BYTE &&
624 testend && em->start + em->len > start + len) {
625 u64 diff = start + len - em->start;
627 split->start = start + len;
628 split->len = em->start + em->len - (start + len);
629 split->bdev = em->bdev;
630 split->flags = flags;
631 split->compress_type = em->compress_type;
632 split->generation = gen;
633 split->orig_block_len = max(em->block_len,
635 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 + diff;
644 split->orig_start = em->orig_start;
647 ret = add_extent_mapping(em_tree, split, modified);
648 BUG_ON(ret); /* Logic error */
649 free_extent_map(split);
653 write_unlock(&em_tree->lock);
657 /* once for the tree*/
661 free_extent_map(split);
663 free_extent_map(split2);
667 * this is very complex, but the basic idea is to drop all extents
668 * in the range start - end. hint_block is filled in with a block number
669 * that would be a good hint to the block allocator for this file.
671 * If an extent intersects the range but is not entirely inside the range
672 * it is either truncated or split. Anything entirely inside the range
673 * is deleted from the tree.
675 int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
676 struct btrfs_root *root, struct inode *inode,
677 struct btrfs_path *path, u64 start, u64 end,
678 u64 *drop_end, int drop_cache)
680 struct extent_buffer *leaf;
681 struct btrfs_file_extent_item *fi;
682 struct btrfs_key key;
683 struct btrfs_key new_key;
684 u64 ino = btrfs_ino(inode);
685 u64 search_start = start;
688 u64 extent_offset = 0;
695 int modify_tree = -1;
696 int update_refs = (root->ref_cows || root == root->fs_info->tree_root);
700 btrfs_drop_extent_cache(inode, start, end - 1, 0);
702 if (start >= BTRFS_I(inode)->disk_i_size)
707 ret = btrfs_lookup_file_extent(trans, root, path, ino,
708 search_start, modify_tree);
711 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
712 leaf = path->nodes[0];
713 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
714 if (key.objectid == ino &&
715 key.type == BTRFS_EXTENT_DATA_KEY)
720 leaf = path->nodes[0];
721 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
723 ret = btrfs_next_leaf(root, path);
730 leaf = path->nodes[0];
734 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
735 if (key.objectid > ino ||
736 key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
739 fi = btrfs_item_ptr(leaf, path->slots[0],
740 struct btrfs_file_extent_item);
741 extent_type = btrfs_file_extent_type(leaf, fi);
743 if (extent_type == BTRFS_FILE_EXTENT_REG ||
744 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
745 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
746 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
747 extent_offset = btrfs_file_extent_offset(leaf, fi);
748 extent_end = key.offset +
749 btrfs_file_extent_num_bytes(leaf, fi);
750 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
751 extent_end = key.offset +
752 btrfs_file_extent_inline_len(leaf, fi);
755 extent_end = search_start;
758 if (extent_end <= search_start) {
764 search_start = max(key.offset, start);
765 if (recow || !modify_tree) {
767 btrfs_release_path(path);
772 * | - range to drop - |
773 * | -------- extent -------- |
775 if (start > key.offset && end < extent_end) {
777 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
779 memcpy(&new_key, &key, sizeof(new_key));
780 new_key.offset = start;
781 ret = btrfs_duplicate_item(trans, root, path,
783 if (ret == -EAGAIN) {
784 btrfs_release_path(path);
790 leaf = path->nodes[0];
791 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
792 struct btrfs_file_extent_item);
793 btrfs_set_file_extent_num_bytes(leaf, fi,
796 fi = btrfs_item_ptr(leaf, path->slots[0],
797 struct btrfs_file_extent_item);
799 extent_offset += start - key.offset;
800 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
801 btrfs_set_file_extent_num_bytes(leaf, fi,
803 btrfs_mark_buffer_dirty(leaf);
805 if (update_refs && disk_bytenr > 0) {
806 ret = btrfs_inc_extent_ref(trans, root,
807 disk_bytenr, num_bytes, 0,
808 root->root_key.objectid,
810 start - extent_offset, 0);
811 BUG_ON(ret); /* -ENOMEM */
816 * | ---- range to drop ----- |
817 * | -------- extent -------- |
819 if (start <= key.offset && end < extent_end) {
820 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
822 memcpy(&new_key, &key, sizeof(new_key));
823 new_key.offset = end;
824 btrfs_set_item_key_safe(root, path, &new_key);
826 extent_offset += end - key.offset;
827 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
828 btrfs_set_file_extent_num_bytes(leaf, fi,
830 btrfs_mark_buffer_dirty(leaf);
831 if (update_refs && disk_bytenr > 0)
832 inode_sub_bytes(inode, end - key.offset);
836 search_start = extent_end;
838 * | ---- range to drop ----- |
839 * | -------- extent -------- |
841 if (start > key.offset && end >= extent_end) {
843 BUG_ON(extent_type == BTRFS_FILE_EXTENT_INLINE);
845 btrfs_set_file_extent_num_bytes(leaf, fi,
847 btrfs_mark_buffer_dirty(leaf);
848 if (update_refs && disk_bytenr > 0)
849 inode_sub_bytes(inode, extent_end - start);
850 if (end == extent_end)
858 * | ---- range to drop ----- |
859 * | ------ extent ------ |
861 if (start <= key.offset && end >= extent_end) {
863 del_slot = path->slots[0];
866 BUG_ON(del_slot + del_nr != path->slots[0]);
871 extent_type == BTRFS_FILE_EXTENT_INLINE) {
872 inode_sub_bytes(inode,
873 extent_end - key.offset);
874 extent_end = ALIGN(extent_end,
876 } else if (update_refs && disk_bytenr > 0) {
877 ret = btrfs_free_extent(trans, root,
878 disk_bytenr, num_bytes, 0,
879 root->root_key.objectid,
880 key.objectid, key.offset -
882 BUG_ON(ret); /* -ENOMEM */
883 inode_sub_bytes(inode,
884 extent_end - key.offset);
887 if (end == extent_end)
890 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
895 ret = btrfs_del_items(trans, root, path, del_slot,
898 btrfs_abort_transaction(trans, root, ret);
905 btrfs_release_path(path);
912 if (!ret && del_nr > 0) {
913 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
915 btrfs_abort_transaction(trans, root, ret);
919 *drop_end = found ? min(end, extent_end) : end;
920 btrfs_release_path(path);
924 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
925 struct btrfs_root *root, struct inode *inode, u64 start,
926 u64 end, int drop_cache)
928 struct btrfs_path *path;
931 path = btrfs_alloc_path();
934 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
936 btrfs_free_path(path);
940 static int extent_mergeable(struct extent_buffer *leaf, int slot,
941 u64 objectid, u64 bytenr, u64 orig_offset,
942 u64 *start, u64 *end)
944 struct btrfs_file_extent_item *fi;
945 struct btrfs_key key;
948 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
951 btrfs_item_key_to_cpu(leaf, &key, slot);
952 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
955 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
956 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
957 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
958 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
959 btrfs_file_extent_compression(leaf, fi) ||
960 btrfs_file_extent_encryption(leaf, fi) ||
961 btrfs_file_extent_other_encoding(leaf, fi))
964 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
965 if ((*start && *start != key.offset) || (*end && *end != extent_end))
974 * Mark extent in the range start - end as written.
976 * This changes extent type from 'pre-allocated' to 'regular'. If only
977 * part of extent is marked as written, the extent will be split into
980 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
981 struct inode *inode, u64 start, u64 end)
983 struct btrfs_root *root = BTRFS_I(inode)->root;
984 struct extent_buffer *leaf;
985 struct btrfs_path *path;
986 struct btrfs_file_extent_item *fi;
987 struct btrfs_key key;
988 struct btrfs_key new_key;
1000 u64 ino = btrfs_ino(inode);
1002 path = btrfs_alloc_path();
1009 key.type = BTRFS_EXTENT_DATA_KEY;
1012 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1015 if (ret > 0 && path->slots[0] > 0)
1018 leaf = path->nodes[0];
1019 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1020 BUG_ON(key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY);
1021 fi = btrfs_item_ptr(leaf, path->slots[0],
1022 struct btrfs_file_extent_item);
1023 BUG_ON(btrfs_file_extent_type(leaf, fi) !=
1024 BTRFS_FILE_EXTENT_PREALLOC);
1025 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1026 BUG_ON(key.offset > start || extent_end < end);
1028 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1029 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1030 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1031 memcpy(&new_key, &key, sizeof(new_key));
1033 if (start == key.offset && end < extent_end) {
1036 if (extent_mergeable(leaf, path->slots[0] - 1,
1037 ino, bytenr, orig_offset,
1038 &other_start, &other_end)) {
1039 new_key.offset = end;
1040 btrfs_set_item_key_safe(root, path, &new_key);
1041 fi = btrfs_item_ptr(leaf, path->slots[0],
1042 struct btrfs_file_extent_item);
1043 btrfs_set_file_extent_generation(leaf, fi,
1045 btrfs_set_file_extent_num_bytes(leaf, fi,
1047 btrfs_set_file_extent_offset(leaf, fi,
1049 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1050 struct btrfs_file_extent_item);
1051 btrfs_set_file_extent_generation(leaf, fi,
1053 btrfs_set_file_extent_num_bytes(leaf, fi,
1055 btrfs_mark_buffer_dirty(leaf);
1060 if (start > key.offset && end == extent_end) {
1063 if (extent_mergeable(leaf, path->slots[0] + 1,
1064 ino, bytenr, orig_offset,
1065 &other_start, &other_end)) {
1066 fi = btrfs_item_ptr(leaf, path->slots[0],
1067 struct btrfs_file_extent_item);
1068 btrfs_set_file_extent_num_bytes(leaf, fi,
1069 start - key.offset);
1070 btrfs_set_file_extent_generation(leaf, fi,
1073 new_key.offset = start;
1074 btrfs_set_item_key_safe(root, path, &new_key);
1076 fi = btrfs_item_ptr(leaf, path->slots[0],
1077 struct btrfs_file_extent_item);
1078 btrfs_set_file_extent_generation(leaf, fi,
1080 btrfs_set_file_extent_num_bytes(leaf, fi,
1082 btrfs_set_file_extent_offset(leaf, fi,
1083 start - orig_offset);
1084 btrfs_mark_buffer_dirty(leaf);
1089 while (start > key.offset || end < extent_end) {
1090 if (key.offset == start)
1093 new_key.offset = split;
1094 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1095 if (ret == -EAGAIN) {
1096 btrfs_release_path(path);
1100 btrfs_abort_transaction(trans, root, ret);
1104 leaf = path->nodes[0];
1105 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1106 struct btrfs_file_extent_item);
1107 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1108 btrfs_set_file_extent_num_bytes(leaf, fi,
1109 split - key.offset);
1111 fi = btrfs_item_ptr(leaf, path->slots[0],
1112 struct btrfs_file_extent_item);
1114 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1115 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1116 btrfs_set_file_extent_num_bytes(leaf, fi,
1117 extent_end - split);
1118 btrfs_mark_buffer_dirty(leaf);
1120 ret = btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, 0,
1121 root->root_key.objectid,
1122 ino, orig_offset, 0);
1123 BUG_ON(ret); /* -ENOMEM */
1125 if (split == start) {
1128 BUG_ON(start != key.offset);
1137 if (extent_mergeable(leaf, path->slots[0] + 1,
1138 ino, bytenr, orig_offset,
1139 &other_start, &other_end)) {
1141 btrfs_release_path(path);
1144 extent_end = other_end;
1145 del_slot = path->slots[0] + 1;
1147 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1148 0, root->root_key.objectid,
1149 ino, orig_offset, 0);
1150 BUG_ON(ret); /* -ENOMEM */
1154 if (extent_mergeable(leaf, path->slots[0] - 1,
1155 ino, bytenr, orig_offset,
1156 &other_start, &other_end)) {
1158 btrfs_release_path(path);
1161 key.offset = other_start;
1162 del_slot = path->slots[0];
1164 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1165 0, root->root_key.objectid,
1166 ino, orig_offset, 0);
1167 BUG_ON(ret); /* -ENOMEM */
1170 fi = btrfs_item_ptr(leaf, path->slots[0],
1171 struct btrfs_file_extent_item);
1172 btrfs_set_file_extent_type(leaf, fi,
1173 BTRFS_FILE_EXTENT_REG);
1174 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1175 btrfs_mark_buffer_dirty(leaf);
1177 fi = btrfs_item_ptr(leaf, del_slot - 1,
1178 struct btrfs_file_extent_item);
1179 btrfs_set_file_extent_type(leaf, fi,
1180 BTRFS_FILE_EXTENT_REG);
1181 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1182 btrfs_set_file_extent_num_bytes(leaf, fi,
1183 extent_end - key.offset);
1184 btrfs_mark_buffer_dirty(leaf);
1186 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1188 btrfs_abort_transaction(trans, root, ret);
1193 btrfs_free_path(path);
1198 * on error we return an unlocked page and the error value
1199 * on success we return a locked page and 0
1201 static int prepare_uptodate_page(struct page *page, u64 pos,
1202 bool force_uptodate)
1206 if (((pos & (PAGE_CACHE_SIZE - 1)) || force_uptodate) &&
1207 !PageUptodate(page)) {
1208 ret = btrfs_readpage(NULL, page);
1212 if (!PageUptodate(page)) {
1221 * this gets pages into the page cache and locks them down, it also properly
1222 * waits for data=ordered extents to finish before allowing the pages to be
1225 static noinline int prepare_pages(struct btrfs_root *root, struct file *file,
1226 struct page **pages, size_t num_pages,
1227 loff_t pos, unsigned long first_index,
1228 size_t write_bytes, bool force_uptodate)
1230 struct extent_state *cached_state = NULL;
1232 unsigned long index = pos >> PAGE_CACHE_SHIFT;
1233 struct inode *inode = file_inode(file);
1234 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1240 start_pos = pos & ~((u64)root->sectorsize - 1);
1241 last_pos = ((u64)index + num_pages) << PAGE_CACHE_SHIFT;
1244 for (i = 0; i < num_pages; i++) {
1245 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1246 mask | __GFP_WRITE);
1254 err = prepare_uptodate_page(pages[i], pos,
1256 if (i == num_pages - 1)
1257 err = prepare_uptodate_page(pages[i],
1258 pos + write_bytes, false);
1260 page_cache_release(pages[i]);
1264 wait_on_page_writeback(pages[i]);
1267 if (start_pos < inode->i_size) {
1268 struct btrfs_ordered_extent *ordered;
1269 lock_extent_bits(&BTRFS_I(inode)->io_tree,
1270 start_pos, last_pos - 1, 0, &cached_state);
1271 ordered = btrfs_lookup_first_ordered_extent(inode,
1274 ordered->file_offset + ordered->len > start_pos &&
1275 ordered->file_offset < last_pos) {
1276 btrfs_put_ordered_extent(ordered);
1277 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1278 start_pos, last_pos - 1,
1279 &cached_state, GFP_NOFS);
1280 for (i = 0; i < num_pages; i++) {
1281 unlock_page(pages[i]);
1282 page_cache_release(pages[i]);
1284 btrfs_wait_ordered_range(inode, start_pos,
1285 last_pos - start_pos);
1289 btrfs_put_ordered_extent(ordered);
1291 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos,
1292 last_pos - 1, EXTENT_DIRTY | EXTENT_DELALLOC |
1293 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG,
1294 0, 0, &cached_state, GFP_NOFS);
1295 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1296 start_pos, last_pos - 1, &cached_state,
1299 for (i = 0; i < num_pages; i++) {
1300 if (clear_page_dirty_for_io(pages[i]))
1301 account_page_redirty(pages[i]);
1302 set_page_extent_mapped(pages[i]);
1303 WARN_ON(!PageLocked(pages[i]));
1307 while (faili >= 0) {
1308 unlock_page(pages[faili]);
1309 page_cache_release(pages[faili]);
1316 static noinline int check_can_nocow(struct inode *inode, loff_t pos,
1317 size_t *write_bytes)
1319 struct btrfs_trans_handle *trans;
1320 struct btrfs_root *root = BTRFS_I(inode)->root;
1321 struct btrfs_ordered_extent *ordered;
1322 u64 lockstart, lockend;
1326 lockstart = round_down(pos, root->sectorsize);
1327 lockend = lockstart + round_up(*write_bytes, root->sectorsize) - 1;
1330 lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1331 ordered = btrfs_lookup_ordered_range(inode, lockstart,
1332 lockend - lockstart + 1);
1336 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1337 btrfs_start_ordered_extent(inode, ordered, 1);
1338 btrfs_put_ordered_extent(ordered);
1341 trans = btrfs_join_transaction(root);
1342 if (IS_ERR(trans)) {
1343 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1344 return PTR_ERR(trans);
1347 num_bytes = lockend - lockstart + 1;
1348 ret = can_nocow_extent(trans, inode, lockstart, &num_bytes, NULL, NULL,
1350 btrfs_end_transaction(trans, root);
1354 clear_extent_bit(&BTRFS_I(inode)->io_tree, lockstart, lockend,
1355 EXTENT_DIRTY | EXTENT_DELALLOC |
1356 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0,
1358 *write_bytes = min_t(size_t, *write_bytes, num_bytes);
1361 unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend);
1366 static noinline ssize_t __btrfs_buffered_write(struct file *file,
1370 struct inode *inode = file_inode(file);
1371 struct btrfs_root *root = BTRFS_I(inode)->root;
1372 struct page **pages = NULL;
1373 u64 release_bytes = 0;
1374 unsigned long first_index;
1375 size_t num_written = 0;
1378 bool only_release_metadata = false;
1379 bool force_page_uptodate = false;
1381 nrptrs = min((iov_iter_count(i) + PAGE_CACHE_SIZE - 1) /
1382 PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
1383 (sizeof(struct page *)));
1384 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1385 nrptrs = max(nrptrs, 8);
1386 pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
1390 first_index = pos >> PAGE_CACHE_SHIFT;
1392 while (iov_iter_count(i) > 0) {
1393 size_t offset = pos & (PAGE_CACHE_SIZE - 1);
1394 size_t write_bytes = min(iov_iter_count(i),
1395 nrptrs * (size_t)PAGE_CACHE_SIZE -
1397 size_t num_pages = (write_bytes + offset +
1398 PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
1399 size_t reserve_bytes;
1403 WARN_ON(num_pages > nrptrs);
1406 * Fault pages before locking them in prepare_pages
1407 * to avoid recursive lock
1409 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1414 reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
1415 ret = btrfs_check_data_free_space(inode, reserve_bytes);
1416 if (ret == -ENOSPC &&
1417 (BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1418 BTRFS_INODE_PREALLOC))) {
1419 ret = check_can_nocow(inode, pos, &write_bytes);
1421 only_release_metadata = true;
1423 * our prealloc extent may be smaller than
1424 * write_bytes, so scale down.
1426 num_pages = (write_bytes + offset +
1427 PAGE_CACHE_SIZE - 1) >>
1429 reserve_bytes = num_pages << PAGE_CACHE_SHIFT;
1439 ret = btrfs_delalloc_reserve_metadata(inode, reserve_bytes);
1441 if (!only_release_metadata)
1442 btrfs_free_reserved_data_space(inode,
1447 release_bytes = reserve_bytes;
1450 * This is going to setup the pages array with the number of
1451 * pages we want, so we don't really need to worry about the
1452 * contents of pages from loop to loop
1454 ret = prepare_pages(root, file, pages, num_pages,
1455 pos, first_index, write_bytes,
1456 force_page_uptodate);
1460 copied = btrfs_copy_from_user(pos, num_pages,
1461 write_bytes, pages, i);
1464 * if we have trouble faulting in the pages, fall
1465 * back to one page at a time
1467 if (copied < write_bytes)
1471 force_page_uptodate = true;
1474 force_page_uptodate = false;
1475 dirty_pages = (copied + offset +
1476 PAGE_CACHE_SIZE - 1) >>
1481 * If we had a short copy we need to release the excess delaloc
1482 * bytes we reserved. We need to increment outstanding_extents
1483 * because btrfs_delalloc_release_space will decrement it, but
1484 * we still have an outstanding extent for the chunk we actually
1487 if (num_pages > dirty_pages) {
1488 release_bytes = (num_pages - dirty_pages) <<
1491 spin_lock(&BTRFS_I(inode)->lock);
1492 BTRFS_I(inode)->outstanding_extents++;
1493 spin_unlock(&BTRFS_I(inode)->lock);
1495 if (only_release_metadata)
1496 btrfs_delalloc_release_metadata(inode,
1499 btrfs_delalloc_release_space(inode,
1503 release_bytes = dirty_pages << PAGE_CACHE_SHIFT;
1505 ret = btrfs_dirty_pages(root, inode, pages,
1506 dirty_pages, pos, copied,
1509 btrfs_drop_pages(pages, num_pages);
1515 btrfs_drop_pages(pages, num_pages);
1517 if (only_release_metadata && copied > 0) {
1518 u64 lockstart = round_down(pos, root->sectorsize);
1519 u64 lockend = lockstart +
1520 (dirty_pages << PAGE_CACHE_SHIFT) - 1;
1522 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1523 lockend, EXTENT_NORESERVE, NULL,
1525 only_release_metadata = false;
1530 balance_dirty_pages_ratelimited(inode->i_mapping);
1531 if (dirty_pages < (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
1532 btrfs_btree_balance_dirty(root);
1535 num_written += copied;
1540 if (release_bytes) {
1541 if (only_release_metadata)
1542 btrfs_delalloc_release_metadata(inode, release_bytes);
1544 btrfs_delalloc_release_space(inode, release_bytes);
1547 return num_written ? num_written : ret;
1550 static ssize_t __btrfs_direct_write(struct kiocb *iocb,
1551 const struct iovec *iov,
1552 unsigned long nr_segs, loff_t pos,
1553 loff_t *ppos, size_t count, size_t ocount)
1555 struct file *file = iocb->ki_filp;
1558 ssize_t written_buffered;
1562 written = generic_file_direct_write(iocb, iov, &nr_segs, pos, ppos,
1565 if (written < 0 || written == count)
1570 iov_iter_init(&i, iov, nr_segs, count, written);
1571 written_buffered = __btrfs_buffered_write(file, &i, pos);
1572 if (written_buffered < 0) {
1573 err = written_buffered;
1576 endbyte = pos + written_buffered - 1;
1577 err = filemap_write_and_wait_range(file->f_mapping, pos, endbyte);
1580 written += written_buffered;
1581 *ppos = pos + written_buffered;
1582 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_CACHE_SHIFT,
1583 endbyte >> PAGE_CACHE_SHIFT);
1585 return written ? written : err;
1588 static void update_time_for_write(struct inode *inode)
1590 struct timespec now;
1592 if (IS_NOCMTIME(inode))
1595 now = current_fs_time(inode->i_sb);
1596 if (!timespec_equal(&inode->i_mtime, &now))
1597 inode->i_mtime = now;
1599 if (!timespec_equal(&inode->i_ctime, &now))
1600 inode->i_ctime = now;
1602 if (IS_I_VERSION(inode))
1603 inode_inc_iversion(inode);
1606 static ssize_t btrfs_file_aio_write(struct kiocb *iocb,
1607 const struct iovec *iov,
1608 unsigned long nr_segs, loff_t pos)
1610 struct file *file = iocb->ki_filp;
1611 struct inode *inode = file_inode(file);
1612 struct btrfs_root *root = BTRFS_I(inode)->root;
1613 loff_t *ppos = &iocb->ki_pos;
1615 ssize_t num_written = 0;
1617 size_t count, ocount;
1618 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
1620 mutex_lock(&inode->i_mutex);
1622 err = generic_segment_checks(iov, &nr_segs, &ocount, VERIFY_READ);
1624 mutex_unlock(&inode->i_mutex);
1629 current->backing_dev_info = inode->i_mapping->backing_dev_info;
1630 err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode));
1632 mutex_unlock(&inode->i_mutex);
1637 mutex_unlock(&inode->i_mutex);
1641 err = file_remove_suid(file);
1643 mutex_unlock(&inode->i_mutex);
1648 * If BTRFS flips readonly due to some impossible error
1649 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1650 * although we have opened a file as writable, we have
1651 * to stop this write operation to ensure FS consistency.
1653 if (test_bit(BTRFS_FS_STATE_ERROR, &root->fs_info->fs_state)) {
1654 mutex_unlock(&inode->i_mutex);
1660 * We reserve space for updating the inode when we reserve space for the
1661 * extent we are going to write, so we will enospc out there. We don't
1662 * need to start yet another transaction to update the inode as we will
1663 * update the inode when we finish writing whatever data we write.
1665 update_time_for_write(inode);
1667 start_pos = round_down(pos, root->sectorsize);
1668 if (start_pos > i_size_read(inode)) {
1669 err = btrfs_cont_expand(inode, i_size_read(inode), start_pos);
1671 mutex_unlock(&inode->i_mutex);
1677 atomic_inc(&BTRFS_I(inode)->sync_writers);
1679 if (unlikely(file->f_flags & O_DIRECT)) {
1680 num_written = __btrfs_direct_write(iocb, iov, nr_segs,
1681 pos, ppos, count, ocount);
1685 iov_iter_init(&i, iov, nr_segs, count, num_written);
1687 num_written = __btrfs_buffered_write(file, &i, pos);
1688 if (num_written > 0)
1689 *ppos = pos + num_written;
1692 mutex_unlock(&inode->i_mutex);
1695 * we want to make sure fsync finds this change
1696 * but we haven't joined a transaction running right now.
1698 * Later on, someone is sure to update the inode and get the
1699 * real transid recorded.
1701 * We set last_trans now to the fs_info generation + 1,
1702 * this will either be one more than the running transaction
1703 * or the generation used for the next transaction if there isn't
1704 * one running right now.
1706 * We also have to set last_sub_trans to the current log transid,
1707 * otherwise subsequent syncs to a file that's been synced in this
1708 * transaction will appear to have already occured.
1710 BTRFS_I(inode)->last_trans = root->fs_info->generation + 1;
1711 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1712 if (num_written > 0 || num_written == -EIOCBQUEUED) {
1713 err = generic_write_sync(file, pos, num_written);
1714 if (err < 0 && num_written > 0)
1719 atomic_dec(&BTRFS_I(inode)->sync_writers);
1721 current->backing_dev_info = NULL;
1722 return num_written ? num_written : err;
1725 int btrfs_release_file(struct inode *inode, struct file *filp)
1728 * ordered_data_close is set by settattr when we are about to truncate
1729 * a file from a non-zero size to a zero size. This tries to
1730 * flush down new bytes that may have been written if the
1731 * application were using truncate to replace a file in place.
1733 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
1734 &BTRFS_I(inode)->runtime_flags)) {
1735 struct btrfs_trans_handle *trans;
1736 struct btrfs_root *root = BTRFS_I(inode)->root;
1739 * We need to block on a committing transaction to keep us from
1740 * throwing a ordered operation on to the list and causing
1741 * something like sync to deadlock trying to flush out this
1744 trans = btrfs_start_transaction(root, 0);
1746 return PTR_ERR(trans);
1747 btrfs_add_ordered_operation(trans, BTRFS_I(inode)->root, inode);
1748 btrfs_end_transaction(trans, root);
1749 if (inode->i_size > BTRFS_ORDERED_OPERATIONS_FLUSH_LIMIT)
1750 filemap_flush(inode->i_mapping);
1752 if (filp->private_data)
1753 btrfs_ioctl_trans_end(filp);
1758 * fsync call for both files and directories. This logs the inode into
1759 * the tree log instead of forcing full commits whenever possible.
1761 * It needs to call filemap_fdatawait so that all ordered extent updates are
1762 * in the metadata btree are up to date for copying to the log.
1764 * It drops the inode mutex before doing the tree log commit. This is an
1765 * important optimization for directories because holding the mutex prevents
1766 * new operations on the dir while we write to disk.
1768 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
1770 struct dentry *dentry = file->f_path.dentry;
1771 struct inode *inode = dentry->d_inode;
1772 struct btrfs_root *root = BTRFS_I(inode)->root;
1774 struct btrfs_trans_handle *trans;
1777 trace_btrfs_sync_file(file, datasync);
1780 * We write the dirty pages in the range and wait until they complete
1781 * out of the ->i_mutex. If so, we can flush the dirty pages by
1782 * multi-task, and make the performance up. See
1783 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
1785 atomic_inc(&BTRFS_I(inode)->sync_writers);
1786 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
1787 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
1788 &BTRFS_I(inode)->runtime_flags))
1789 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
1790 atomic_dec(&BTRFS_I(inode)->sync_writers);
1794 mutex_lock(&inode->i_mutex);
1797 * We flush the dirty pages again to avoid some dirty pages in the
1800 atomic_inc(&root->log_batch);
1801 full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1802 &BTRFS_I(inode)->runtime_flags);
1804 btrfs_wait_ordered_range(inode, start, end - start + 1);
1805 atomic_inc(&root->log_batch);
1808 * check the transaction that last modified this inode
1809 * and see if its already been committed
1811 if (!BTRFS_I(inode)->last_trans) {
1812 mutex_unlock(&inode->i_mutex);
1817 * if the last transaction that changed this file was before
1818 * the current transaction, we can bail out now without any
1822 if (btrfs_inode_in_log(inode, root->fs_info->generation) ||
1823 BTRFS_I(inode)->last_trans <=
1824 root->fs_info->last_trans_committed) {
1825 BTRFS_I(inode)->last_trans = 0;
1828 * We'v had everything committed since the last time we were
1829 * modified so clear this flag in case it was set for whatever
1830 * reason, it's no longer relevant.
1832 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
1833 &BTRFS_I(inode)->runtime_flags);
1834 mutex_unlock(&inode->i_mutex);
1839 * ok we haven't committed the transaction yet, lets do a commit
1841 if (file->private_data)
1842 btrfs_ioctl_trans_end(file);
1844 trans = btrfs_start_transaction(root, 0);
1845 if (IS_ERR(trans)) {
1846 ret = PTR_ERR(trans);
1847 mutex_unlock(&inode->i_mutex);
1851 ret = btrfs_log_dentry_safe(trans, root, dentry);
1853 mutex_unlock(&inode->i_mutex);
1857 /* we've logged all the items and now have a consistent
1858 * version of the file in the log. It is possible that
1859 * someone will come in and modify the file, but that's
1860 * fine because the log is consistent on disk, and we
1861 * have references to all of the file's extents
1863 * It is possible that someone will come in and log the
1864 * file again, but that will end up using the synchronization
1865 * inside btrfs_sync_log to keep things safe.
1867 mutex_unlock(&inode->i_mutex);
1869 if (ret != BTRFS_NO_LOG_SYNC) {
1872 * If we didn't already wait for ordered extents we need
1876 btrfs_wait_ordered_range(inode, start,
1878 ret = btrfs_commit_transaction(trans, root);
1880 ret = btrfs_sync_log(trans, root);
1882 ret = btrfs_end_transaction(trans, root);
1885 btrfs_wait_ordered_range(inode, start,
1888 ret = btrfs_commit_transaction(trans, root);
1892 ret = btrfs_end_transaction(trans, root);
1895 return ret > 0 ? -EIO : ret;
1898 static const struct vm_operations_struct btrfs_file_vm_ops = {
1899 .fault = filemap_fault,
1900 .page_mkwrite = btrfs_page_mkwrite,
1901 .remap_pages = generic_file_remap_pages,
1904 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
1906 struct address_space *mapping = filp->f_mapping;
1908 if (!mapping->a_ops->readpage)
1911 file_accessed(filp);
1912 vma->vm_ops = &btrfs_file_vm_ops;
1917 static int hole_mergeable(struct inode *inode, struct extent_buffer *leaf,
1918 int slot, u64 start, u64 end)
1920 struct btrfs_file_extent_item *fi;
1921 struct btrfs_key key;
1923 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1926 btrfs_item_key_to_cpu(leaf, &key, slot);
1927 if (key.objectid != btrfs_ino(inode) ||
1928 key.type != BTRFS_EXTENT_DATA_KEY)
1931 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1933 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
1936 if (btrfs_file_extent_disk_bytenr(leaf, fi))
1939 if (key.offset == end)
1941 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
1946 static int fill_holes(struct btrfs_trans_handle *trans, struct inode *inode,
1947 struct btrfs_path *path, u64 offset, u64 end)
1949 struct btrfs_root *root = BTRFS_I(inode)->root;
1950 struct extent_buffer *leaf;
1951 struct btrfs_file_extent_item *fi;
1952 struct extent_map *hole_em;
1953 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
1954 struct btrfs_key key;
1957 key.objectid = btrfs_ino(inode);
1958 key.type = BTRFS_EXTENT_DATA_KEY;
1959 key.offset = offset;
1962 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
1967 leaf = path->nodes[0];
1968 if (hole_mergeable(inode, leaf, path->slots[0]-1, offset, end)) {
1972 fi = btrfs_item_ptr(leaf, path->slots[0],
1973 struct btrfs_file_extent_item);
1974 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
1976 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1977 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
1978 btrfs_set_file_extent_offset(leaf, fi, 0);
1979 btrfs_mark_buffer_dirty(leaf);
1983 if (hole_mergeable(inode, leaf, path->slots[0]+1, offset, end)) {
1987 key.offset = offset;
1988 btrfs_set_item_key_safe(root, path, &key);
1989 fi = btrfs_item_ptr(leaf, path->slots[0],
1990 struct btrfs_file_extent_item);
1991 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
1993 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
1994 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
1995 btrfs_set_file_extent_offset(leaf, fi, 0);
1996 btrfs_mark_buffer_dirty(leaf);
1999 btrfs_release_path(path);
2001 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode), offset,
2002 0, 0, end - offset, 0, end - offset,
2008 btrfs_release_path(path);
2010 hole_em = alloc_extent_map();
2012 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2013 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2014 &BTRFS_I(inode)->runtime_flags);
2016 hole_em->start = offset;
2017 hole_em->len = end - offset;
2018 hole_em->ram_bytes = hole_em->len;
2019 hole_em->orig_start = offset;
2021 hole_em->block_start = EXTENT_MAP_HOLE;
2022 hole_em->block_len = 0;
2023 hole_em->orig_block_len = 0;
2024 hole_em->bdev = root->fs_info->fs_devices->latest_bdev;
2025 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2026 hole_em->generation = trans->transid;
2029 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2030 write_lock(&em_tree->lock);
2031 ret = add_extent_mapping(em_tree, hole_em, 1);
2032 write_unlock(&em_tree->lock);
2033 } while (ret == -EEXIST);
2034 free_extent_map(hole_em);
2036 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2037 &BTRFS_I(inode)->runtime_flags);
2043 static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2045 struct btrfs_root *root = BTRFS_I(inode)->root;
2046 struct extent_state *cached_state = NULL;
2047 struct btrfs_path *path;
2048 struct btrfs_block_rsv *rsv;
2049 struct btrfs_trans_handle *trans;
2050 u64 lockstart = round_up(offset, BTRFS_I(inode)->root->sectorsize);
2051 u64 lockend = round_down(offset + len,
2052 BTRFS_I(inode)->root->sectorsize) - 1;
2053 u64 cur_offset = lockstart;
2054 u64 min_size = btrfs_calc_trunc_metadata_size(root, 1);
2058 bool same_page = ((offset >> PAGE_CACHE_SHIFT) ==
2059 ((offset + len - 1) >> PAGE_CACHE_SHIFT));
2061 btrfs_wait_ordered_range(inode, offset, len);
2063 mutex_lock(&inode->i_mutex);
2065 * We needn't truncate any page which is beyond the end of the file
2066 * because we are sure there is no data there.
2069 * Only do this if we are in the same page and we aren't doing the
2072 if (same_page && len < PAGE_CACHE_SIZE) {
2073 if (offset < round_up(inode->i_size, PAGE_CACHE_SIZE))
2074 ret = btrfs_truncate_page(inode, offset, len, 0);
2075 mutex_unlock(&inode->i_mutex);
2079 /* zero back part of the first page */
2080 if (offset < round_up(inode->i_size, PAGE_CACHE_SIZE)) {
2081 ret = btrfs_truncate_page(inode, offset, 0, 0);
2083 mutex_unlock(&inode->i_mutex);
2088 /* zero the front end of the last page */
2089 if (offset + len < round_up(inode->i_size, PAGE_CACHE_SIZE)) {
2090 ret = btrfs_truncate_page(inode, offset + len, 0, 1);
2092 mutex_unlock(&inode->i_mutex);
2097 if (lockend < lockstart) {
2098 mutex_unlock(&inode->i_mutex);
2103 struct btrfs_ordered_extent *ordered;
2105 truncate_pagecache_range(inode, lockstart, lockend);
2107 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2109 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2112 * We need to make sure we have no ordered extents in this range
2113 * and nobody raced in and read a page in this range, if we did
2114 * we need to try again.
2117 (ordered->file_offset + ordered->len < lockstart ||
2118 ordered->file_offset > lockend)) &&
2119 !test_range_bit(&BTRFS_I(inode)->io_tree, lockstart,
2120 lockend, EXTENT_UPTODATE, 0,
2123 btrfs_put_ordered_extent(ordered);
2127 btrfs_put_ordered_extent(ordered);
2128 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2129 lockend, &cached_state, GFP_NOFS);
2130 btrfs_wait_ordered_range(inode, lockstart,
2131 lockend - lockstart + 1);
2134 path = btrfs_alloc_path();
2140 rsv = btrfs_alloc_block_rsv(root, BTRFS_BLOCK_RSV_TEMP);
2145 rsv->size = btrfs_calc_trunc_metadata_size(root, 1);
2149 * 1 - update the inode
2150 * 1 - removing the extents in the range
2151 * 1 - adding the hole extent
2153 trans = btrfs_start_transaction(root, 3);
2154 if (IS_ERR(trans)) {
2155 err = PTR_ERR(trans);
2159 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv, rsv,
2162 trans->block_rsv = rsv;
2164 while (cur_offset < lockend) {
2165 ret = __btrfs_drop_extents(trans, root, inode, path,
2166 cur_offset, lockend + 1,
2171 trans->block_rsv = &root->fs_info->trans_block_rsv;
2173 ret = fill_holes(trans, inode, path, cur_offset, drop_end);
2179 cur_offset = drop_end;
2181 ret = btrfs_update_inode(trans, root, inode);
2187 btrfs_end_transaction(trans, root);
2188 btrfs_btree_balance_dirty(root);
2190 trans = btrfs_start_transaction(root, 3);
2191 if (IS_ERR(trans)) {
2192 ret = PTR_ERR(trans);
2197 ret = btrfs_block_rsv_migrate(&root->fs_info->trans_block_rsv,
2199 BUG_ON(ret); /* shouldn't happen */
2200 trans->block_rsv = rsv;
2208 trans->block_rsv = &root->fs_info->trans_block_rsv;
2209 ret = fill_holes(trans, inode, path, cur_offset, drop_end);
2219 inode_inc_iversion(inode);
2220 inode->i_mtime = inode->i_ctime = CURRENT_TIME;
2222 trans->block_rsv = &root->fs_info->trans_block_rsv;
2223 ret = btrfs_update_inode(trans, root, inode);
2224 btrfs_end_transaction(trans, root);
2225 btrfs_btree_balance_dirty(root);
2227 btrfs_free_path(path);
2228 btrfs_free_block_rsv(root, rsv);
2230 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2231 &cached_state, GFP_NOFS);
2232 mutex_unlock(&inode->i_mutex);
2238 static long btrfs_fallocate(struct file *file, int mode,
2239 loff_t offset, loff_t len)
2241 struct inode *inode = file_inode(file);
2242 struct extent_state *cached_state = NULL;
2243 struct btrfs_root *root = BTRFS_I(inode)->root;
2250 struct extent_map *em;
2251 int blocksize = BTRFS_I(inode)->root->sectorsize;
2254 alloc_start = round_down(offset, blocksize);
2255 alloc_end = round_up(offset + len, blocksize);
2257 /* Make sure we aren't being give some crap mode */
2258 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
2261 if (mode & FALLOC_FL_PUNCH_HOLE)
2262 return btrfs_punch_hole(inode, offset, len);
2265 * Make sure we have enough space before we do the
2268 ret = btrfs_check_data_free_space(inode, alloc_end - alloc_start);
2271 if (root->fs_info->quota_enabled) {
2272 ret = btrfs_qgroup_reserve(root, alloc_end - alloc_start);
2274 goto out_reserve_fail;
2277 mutex_lock(&inode->i_mutex);
2278 ret = inode_newsize_ok(inode, alloc_end);
2282 if (alloc_start > inode->i_size) {
2283 ret = btrfs_cont_expand(inode, i_size_read(inode),
2289 * If we are fallocating from the end of the file onward we
2290 * need to zero out the end of the page if i_size lands in the
2293 ret = btrfs_truncate_page(inode, inode->i_size, 0, 0);
2299 * wait for ordered IO before we have any locks. We'll loop again
2300 * below with the locks held.
2302 btrfs_wait_ordered_range(inode, alloc_start, alloc_end - alloc_start);
2304 locked_end = alloc_end - 1;
2306 struct btrfs_ordered_extent *ordered;
2308 /* the extent lock is ordered inside the running
2311 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
2312 locked_end, 0, &cached_state);
2313 ordered = btrfs_lookup_first_ordered_extent(inode,
2316 ordered->file_offset + ordered->len > alloc_start &&
2317 ordered->file_offset < alloc_end) {
2318 btrfs_put_ordered_extent(ordered);
2319 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
2320 alloc_start, locked_end,
2321 &cached_state, GFP_NOFS);
2323 * we can't wait on the range with the transaction
2324 * running or with the extent lock held
2326 btrfs_wait_ordered_range(inode, alloc_start,
2327 alloc_end - alloc_start);
2330 btrfs_put_ordered_extent(ordered);
2335 cur_offset = alloc_start;
2339 em = btrfs_get_extent(inode, NULL, 0, cur_offset,
2340 alloc_end - cur_offset, 0);
2341 if (IS_ERR_OR_NULL(em)) {
2348 last_byte = min(extent_map_end(em), alloc_end);
2349 actual_end = min_t(u64, extent_map_end(em), offset + len);
2350 last_byte = ALIGN(last_byte, blocksize);
2352 if (em->block_start == EXTENT_MAP_HOLE ||
2353 (cur_offset >= inode->i_size &&
2354 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
2355 ret = btrfs_prealloc_file_range(inode, mode, cur_offset,
2356 last_byte - cur_offset,
2357 1 << inode->i_blkbits,
2362 free_extent_map(em);
2365 } else if (actual_end > inode->i_size &&
2366 !(mode & FALLOC_FL_KEEP_SIZE)) {
2368 * We didn't need to allocate any more space, but we
2369 * still extended the size of the file so we need to
2372 inode->i_ctime = CURRENT_TIME;
2373 i_size_write(inode, actual_end);
2374 btrfs_ordered_update_i_size(inode, actual_end, NULL);
2376 free_extent_map(em);
2378 cur_offset = last_byte;
2379 if (cur_offset >= alloc_end) {
2384 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
2385 &cached_state, GFP_NOFS);
2387 mutex_unlock(&inode->i_mutex);
2388 if (root->fs_info->quota_enabled)
2389 btrfs_qgroup_free(root, alloc_end - alloc_start);
2391 /* Let go of our reservation. */
2392 btrfs_free_reserved_data_space(inode, alloc_end - alloc_start);
2396 static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
2398 struct btrfs_root *root = BTRFS_I(inode)->root;
2399 struct extent_map *em;
2400 struct extent_state *cached_state = NULL;
2401 u64 lockstart = *offset;
2402 u64 lockend = i_size_read(inode);
2403 u64 start = *offset;
2404 u64 orig_start = *offset;
2405 u64 len = i_size_read(inode);
2409 lockend = max_t(u64, root->sectorsize, lockend);
2410 if (lockend <= lockstart)
2411 lockend = lockstart + root->sectorsize;
2414 len = lockend - lockstart + 1;
2416 len = max_t(u64, len, root->sectorsize);
2417 if (inode->i_size == 0)
2420 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend, 0,
2424 * Delalloc is such a pain. If we have a hole and we have pending
2425 * delalloc for a portion of the hole we will get back a hole that
2426 * exists for the entire range since it hasn't been actually written
2427 * yet. So to take care of this case we need to look for an extent just
2428 * before the position we want in case there is outstanding delalloc
2431 if (whence == SEEK_HOLE && start != 0) {
2432 if (start <= root->sectorsize)
2433 em = btrfs_get_extent_fiemap(inode, NULL, 0, 0,
2434 root->sectorsize, 0);
2436 em = btrfs_get_extent_fiemap(inode, NULL, 0,
2437 start - root->sectorsize,
2438 root->sectorsize, 0);
2443 last_end = em->start + em->len;
2444 if (em->block_start == EXTENT_MAP_DELALLOC)
2445 last_end = min_t(u64, last_end, inode->i_size);
2446 free_extent_map(em);
2450 em = btrfs_get_extent_fiemap(inode, NULL, 0, start, len, 0);
2456 if (em->block_start == EXTENT_MAP_HOLE) {
2457 if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
2458 if (last_end <= orig_start) {
2459 free_extent_map(em);
2465 if (whence == SEEK_HOLE) {
2467 free_extent_map(em);
2471 if (whence == SEEK_DATA) {
2472 if (em->block_start == EXTENT_MAP_DELALLOC) {
2473 if (start >= inode->i_size) {
2474 free_extent_map(em);
2480 if (!test_bit(EXTENT_FLAG_PREALLOC,
2483 free_extent_map(em);
2489 start = em->start + em->len;
2490 last_end = em->start + em->len;
2492 if (em->block_start == EXTENT_MAP_DELALLOC)
2493 last_end = min_t(u64, last_end, inode->i_size);
2495 if (test_bit(EXTENT_FLAG_VACANCY, &em->flags)) {
2496 free_extent_map(em);
2500 free_extent_map(em);
2504 *offset = min(*offset, inode->i_size);
2506 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2507 &cached_state, GFP_NOFS);
2511 static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
2513 struct inode *inode = file->f_mapping->host;
2516 mutex_lock(&inode->i_mutex);
2520 offset = generic_file_llseek(file, offset, whence);
2524 if (offset >= i_size_read(inode)) {
2525 mutex_unlock(&inode->i_mutex);
2529 ret = find_desired_extent(inode, &offset, whence);
2531 mutex_unlock(&inode->i_mutex);
2536 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
2538 mutex_unlock(&inode->i_mutex);
2542 const struct file_operations btrfs_file_operations = {
2543 .llseek = btrfs_file_llseek,
2544 .read = do_sync_read,
2545 .write = do_sync_write,
2546 .aio_read = generic_file_aio_read,
2547 .splice_read = generic_file_splice_read,
2548 .aio_write = btrfs_file_aio_write,
2549 .mmap = btrfs_file_mmap,
2550 .open = generic_file_open,
2551 .release = btrfs_release_file,
2552 .fsync = btrfs_sync_file,
2553 .fallocate = btrfs_fallocate,
2554 .unlocked_ioctl = btrfs_ioctl,
2555 #ifdef CONFIG_COMPAT
2556 .compat_ioctl = btrfs_ioctl,
2560 void btrfs_auto_defrag_exit(void)
2562 if (btrfs_inode_defrag_cachep)
2563 kmem_cache_destroy(btrfs_inode_defrag_cachep);
2566 int btrfs_auto_defrag_init(void)
2568 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
2569 sizeof(struct inode_defrag), 0,
2570 SLAB_RECLAIM_ACCOUNT | SLAB_MEM_SPREAD,
2572 if (!btrfs_inode_defrag_cachep)