1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2007 Oracle. All rights reserved.
7 #include <linux/pagemap.h>
8 #include <linux/time.h>
9 #include <linux/init.h>
10 #include <linux/string.h>
11 #include <linux/backing-dev.h>
12 #include <linux/falloc.h>
13 #include <linux/writeback.h>
14 #include <linux/compat.h>
15 #include <linux/slab.h>
16 #include <linux/btrfs.h>
17 #include <linux/uio.h>
18 #include <linux/iversion.h>
21 #include "transaction.h"
22 #include "btrfs_inode.h"
23 #include "print-tree.h"
28 #include "compression.h"
29 #include "delalloc-space.h"
31 static struct kmem_cache *btrfs_inode_defrag_cachep;
33 * when auto defrag is enabled we
34 * queue up these defrag structs to remember which
35 * inodes need defragging passes
38 struct rb_node rb_node;
42 * transid where the defrag was added, we search for
43 * extents newer than this
50 /* last offset we were able to defrag */
53 /* if we've wrapped around back to zero once already */
57 static int __compare_inode_defrag(struct inode_defrag *defrag1,
58 struct inode_defrag *defrag2)
60 if (defrag1->root > defrag2->root)
62 else if (defrag1->root < defrag2->root)
64 else if (defrag1->ino > defrag2->ino)
66 else if (defrag1->ino < defrag2->ino)
72 /* pop a record for an inode into the defrag tree. The lock
73 * must be held already
75 * If you're inserting a record for an older transid than an
76 * existing record, the transid already in the tree is lowered
78 * If an existing record is found the defrag item you
81 static int __btrfs_add_inode_defrag(struct btrfs_inode *inode,
82 struct inode_defrag *defrag)
84 struct btrfs_fs_info *fs_info = inode->root->fs_info;
85 struct inode_defrag *entry;
87 struct rb_node *parent = NULL;
90 p = &fs_info->defrag_inodes.rb_node;
93 entry = rb_entry(parent, struct inode_defrag, rb_node);
95 ret = __compare_inode_defrag(defrag, entry);
99 p = &parent->rb_right;
101 /* if we're reinserting an entry for
102 * an old defrag run, make sure to
103 * lower the transid of our existing record
105 if (defrag->transid < entry->transid)
106 entry->transid = defrag->transid;
107 if (defrag->last_offset > entry->last_offset)
108 entry->last_offset = defrag->last_offset;
112 set_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags);
113 rb_link_node(&defrag->rb_node, parent, p);
114 rb_insert_color(&defrag->rb_node, &fs_info->defrag_inodes);
118 static inline int __need_auto_defrag(struct btrfs_fs_info *fs_info)
120 if (!btrfs_test_opt(fs_info, AUTO_DEFRAG))
123 if (btrfs_fs_closing(fs_info))
130 * insert a defrag record for this inode if auto defrag is
133 int btrfs_add_inode_defrag(struct btrfs_trans_handle *trans,
134 struct btrfs_inode *inode)
136 struct btrfs_root *root = inode->root;
137 struct btrfs_fs_info *fs_info = root->fs_info;
138 struct inode_defrag *defrag;
142 if (!__need_auto_defrag(fs_info))
145 if (test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags))
149 transid = trans->transid;
151 transid = inode->root->last_trans;
153 defrag = kmem_cache_zalloc(btrfs_inode_defrag_cachep, GFP_NOFS);
157 defrag->ino = btrfs_ino(inode);
158 defrag->transid = transid;
159 defrag->root = root->root_key.objectid;
161 spin_lock(&fs_info->defrag_inodes_lock);
162 if (!test_bit(BTRFS_INODE_IN_DEFRAG, &inode->runtime_flags)) {
164 * If we set IN_DEFRAG flag and evict the inode from memory,
165 * and then re-read this inode, this new inode doesn't have
166 * IN_DEFRAG flag. At the case, we may find the existed defrag.
168 ret = __btrfs_add_inode_defrag(inode, defrag);
170 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
172 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
174 spin_unlock(&fs_info->defrag_inodes_lock);
179 * Requeue the defrag object. If there is a defrag object that points to
180 * the same inode in the tree, we will merge them together (by
181 * __btrfs_add_inode_defrag()) and free the one that we want to requeue.
183 static void btrfs_requeue_inode_defrag(struct btrfs_inode *inode,
184 struct inode_defrag *defrag)
186 struct btrfs_fs_info *fs_info = inode->root->fs_info;
189 if (!__need_auto_defrag(fs_info))
193 * Here we don't check the IN_DEFRAG flag, because we need merge
196 spin_lock(&fs_info->defrag_inodes_lock);
197 ret = __btrfs_add_inode_defrag(inode, defrag);
198 spin_unlock(&fs_info->defrag_inodes_lock);
203 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
207 * pick the defragable inode that we want, if it doesn't exist, we will get
210 static struct inode_defrag *
211 btrfs_pick_defrag_inode(struct btrfs_fs_info *fs_info, u64 root, u64 ino)
213 struct inode_defrag *entry = NULL;
214 struct inode_defrag tmp;
216 struct rb_node *parent = NULL;
222 spin_lock(&fs_info->defrag_inodes_lock);
223 p = fs_info->defrag_inodes.rb_node;
226 entry = rb_entry(parent, struct inode_defrag, rb_node);
228 ret = __compare_inode_defrag(&tmp, entry);
232 p = parent->rb_right;
237 if (parent && __compare_inode_defrag(&tmp, entry) > 0) {
238 parent = rb_next(parent);
240 entry = rb_entry(parent, struct inode_defrag, rb_node);
246 rb_erase(parent, &fs_info->defrag_inodes);
247 spin_unlock(&fs_info->defrag_inodes_lock);
251 void btrfs_cleanup_defrag_inodes(struct btrfs_fs_info *fs_info)
253 struct inode_defrag *defrag;
254 struct rb_node *node;
256 spin_lock(&fs_info->defrag_inodes_lock);
257 node = rb_first(&fs_info->defrag_inodes);
259 rb_erase(node, &fs_info->defrag_inodes);
260 defrag = rb_entry(node, struct inode_defrag, rb_node);
261 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
263 cond_resched_lock(&fs_info->defrag_inodes_lock);
265 node = rb_first(&fs_info->defrag_inodes);
267 spin_unlock(&fs_info->defrag_inodes_lock);
270 #define BTRFS_DEFRAG_BATCH 1024
272 static int __btrfs_run_defrag_inode(struct btrfs_fs_info *fs_info,
273 struct inode_defrag *defrag)
275 struct btrfs_root *inode_root;
277 struct btrfs_key key;
278 struct btrfs_ioctl_defrag_range_args range;
284 key.objectid = defrag->root;
285 key.type = BTRFS_ROOT_ITEM_KEY;
286 key.offset = (u64)-1;
288 index = srcu_read_lock(&fs_info->subvol_srcu);
290 inode_root = btrfs_read_fs_root_no_name(fs_info, &key);
291 if (IS_ERR(inode_root)) {
292 ret = PTR_ERR(inode_root);
296 key.objectid = defrag->ino;
297 key.type = BTRFS_INODE_ITEM_KEY;
299 inode = btrfs_iget(fs_info->sb, &key, inode_root, NULL);
301 ret = PTR_ERR(inode);
304 srcu_read_unlock(&fs_info->subvol_srcu, index);
306 /* do a chunk of defrag */
307 clear_bit(BTRFS_INODE_IN_DEFRAG, &BTRFS_I(inode)->runtime_flags);
308 memset(&range, 0, sizeof(range));
310 range.start = defrag->last_offset;
312 sb_start_write(fs_info->sb);
313 num_defrag = btrfs_defrag_file(inode, NULL, &range, defrag->transid,
315 sb_end_write(fs_info->sb);
317 * if we filled the whole defrag batch, there
318 * must be more work to do. Queue this defrag
321 if (num_defrag == BTRFS_DEFRAG_BATCH) {
322 defrag->last_offset = range.start;
323 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
324 } else if (defrag->last_offset && !defrag->cycled) {
326 * we didn't fill our defrag batch, but
327 * we didn't start at zero. Make sure we loop
328 * around to the start of the file.
330 defrag->last_offset = 0;
332 btrfs_requeue_inode_defrag(BTRFS_I(inode), defrag);
334 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
340 srcu_read_unlock(&fs_info->subvol_srcu, index);
341 kmem_cache_free(btrfs_inode_defrag_cachep, defrag);
346 * run through the list of inodes in the FS that need
349 int btrfs_run_defrag_inodes(struct btrfs_fs_info *fs_info)
351 struct inode_defrag *defrag;
353 u64 root_objectid = 0;
355 atomic_inc(&fs_info->defrag_running);
357 /* Pause the auto defragger. */
358 if (test_bit(BTRFS_FS_STATE_REMOUNTING,
362 if (!__need_auto_defrag(fs_info))
365 /* find an inode to defrag */
366 defrag = btrfs_pick_defrag_inode(fs_info, root_objectid,
369 if (root_objectid || first_ino) {
378 first_ino = defrag->ino + 1;
379 root_objectid = defrag->root;
381 __btrfs_run_defrag_inode(fs_info, defrag);
383 atomic_dec(&fs_info->defrag_running);
386 * during unmount, we use the transaction_wait queue to
387 * wait for the defragger to stop
389 wake_up(&fs_info->transaction_wait);
393 /* simple helper to fault in pages and copy. This should go away
394 * and be replaced with calls into generic code.
396 static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes,
397 struct page **prepared_pages,
401 size_t total_copied = 0;
403 int offset = offset_in_page(pos);
405 while (write_bytes > 0) {
406 size_t count = min_t(size_t,
407 PAGE_SIZE - offset, write_bytes);
408 struct page *page = prepared_pages[pg];
410 * Copy data from userspace to the current page
412 copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
414 /* Flush processor's dcache for this page */
415 flush_dcache_page(page);
418 * if we get a partial write, we can end up with
419 * partially up to date pages. These add
420 * a lot of complexity, so make sure they don't
421 * happen by forcing this copy to be retried.
423 * The rest of the btrfs_file_write code will fall
424 * back to page at a time copies after we return 0.
426 if (!PageUptodate(page) && copied < count)
429 iov_iter_advance(i, copied);
430 write_bytes -= copied;
431 total_copied += copied;
433 /* Return to btrfs_file_write_iter to fault page */
434 if (unlikely(copied == 0))
437 if (copied < PAGE_SIZE - offset) {
448 * unlocks pages after btrfs_file_write is done with them
450 static void btrfs_drop_pages(struct page **pages, size_t num_pages)
453 for (i = 0; i < num_pages; i++) {
454 /* page checked is some magic around finding pages that
455 * have been modified without going through btrfs_set_page_dirty
456 * clear it here. There should be no need to mark the pages
457 * accessed as prepare_pages should have marked them accessed
458 * in prepare_pages via find_or_create_page()
460 ClearPageChecked(pages[i]);
461 unlock_page(pages[i]);
466 static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
469 struct extent_state **cached_state)
471 u64 search_start = start;
472 const u64 end = start + len - 1;
474 while (search_start < end) {
475 const u64 search_len = end - search_start + 1;
476 struct extent_map *em;
480 em = btrfs_get_extent(inode, NULL, 0, search_start,
485 if (em->block_start != EXTENT_MAP_HOLE)
489 if (em->start < search_start)
490 em_len -= search_start - em->start;
491 if (em_len > search_len)
494 ret = set_extent_bit(&inode->io_tree, search_start,
495 search_start + em_len - 1,
497 NULL, cached_state, GFP_NOFS);
499 search_start = extent_map_end(em);
508 * after copy_from_user, pages need to be dirtied and we need to make
509 * sure holes are created between the current EOF and the start of
510 * any next extents (if required).
512 * this also makes the decision about creating an inline extent vs
513 * doing real data extents, marking pages dirty and delalloc as required.
515 int btrfs_dirty_pages(struct inode *inode, struct page **pages,
516 size_t num_pages, loff_t pos, size_t write_bytes,
517 struct extent_state **cached)
519 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
524 u64 end_of_last_block;
525 u64 end_pos = pos + write_bytes;
526 loff_t isize = i_size_read(inode);
527 unsigned int extra_bits = 0;
529 start_pos = pos & ~((u64) fs_info->sectorsize - 1);
530 num_bytes = round_up(write_bytes + pos - start_pos,
531 fs_info->sectorsize);
533 end_of_last_block = start_pos + num_bytes - 1;
536 * The pages may have already been dirty, clear out old accounting so
537 * we can set things up properly
539 clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos, end_of_last_block,
540 EXTENT_DIRTY | EXTENT_DELALLOC |
541 EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0, cached);
543 if (!btrfs_is_free_space_inode(BTRFS_I(inode))) {
544 if (start_pos >= isize &&
545 !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) {
547 * There can't be any extents following eof in this case
548 * so just set the delalloc new bit for the range
551 extra_bits |= EXTENT_DELALLOC_NEW;
553 err = btrfs_find_new_delalloc_bytes(BTRFS_I(inode),
561 err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
562 extra_bits, cached, 0);
566 for (i = 0; i < num_pages; i++) {
567 struct page *p = pages[i];
574 * we've only changed i_size in ram, and we haven't updated
575 * the disk i_size. There is no need to log the inode
579 i_size_write(inode, end_pos);
584 * this drops all the extents in the cache that intersect the range
585 * [start, end]. Existing extents are split as required.
587 void btrfs_drop_extent_cache(struct btrfs_inode *inode, u64 start, u64 end,
590 struct extent_map *em;
591 struct extent_map *split = NULL;
592 struct extent_map *split2 = NULL;
593 struct extent_map_tree *em_tree = &inode->extent_tree;
594 u64 len = end - start + 1;
602 WARN_ON(end < start);
603 if (end == (u64)-1) {
612 split = alloc_extent_map();
614 split2 = alloc_extent_map();
615 if (!split || !split2)
618 write_lock(&em_tree->lock);
619 em = lookup_extent_mapping(em_tree, start, len);
621 write_unlock(&em_tree->lock);
625 gen = em->generation;
626 if (skip_pinned && test_bit(EXTENT_FLAG_PINNED, &em->flags)) {
627 if (testend && em->start + em->len >= start + len) {
629 write_unlock(&em_tree->lock);
632 start = em->start + em->len;
634 len = start + len - (em->start + em->len);
636 write_unlock(&em_tree->lock);
639 compressed = test_bit(EXTENT_FLAG_COMPRESSED, &em->flags);
640 clear_bit(EXTENT_FLAG_PINNED, &em->flags);
641 clear_bit(EXTENT_FLAG_LOGGING, &flags);
642 modified = !list_empty(&em->list);
646 if (em->start < start) {
647 split->start = em->start;
648 split->len = start - em->start;
650 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
651 split->orig_start = em->orig_start;
652 split->block_start = em->block_start;
655 split->block_len = em->block_len;
657 split->block_len = split->len;
658 split->orig_block_len = max(split->block_len,
660 split->ram_bytes = em->ram_bytes;
662 split->orig_start = split->start;
663 split->block_len = 0;
664 split->block_start = em->block_start;
665 split->orig_block_len = 0;
666 split->ram_bytes = split->len;
669 split->generation = gen;
670 split->bdev = em->bdev;
671 split->flags = flags;
672 split->compress_type = em->compress_type;
673 replace_extent_mapping(em_tree, em, split, modified);
674 free_extent_map(split);
678 if (testend && em->start + em->len > start + len) {
679 u64 diff = start + len - em->start;
681 split->start = start + len;
682 split->len = em->start + em->len - (start + len);
683 split->bdev = em->bdev;
684 split->flags = flags;
685 split->compress_type = em->compress_type;
686 split->generation = gen;
688 if (em->block_start < EXTENT_MAP_LAST_BYTE) {
689 split->orig_block_len = max(em->block_len,
692 split->ram_bytes = em->ram_bytes;
694 split->block_len = em->block_len;
695 split->block_start = em->block_start;
696 split->orig_start = em->orig_start;
698 split->block_len = split->len;
699 split->block_start = em->block_start
701 split->orig_start = em->orig_start;
704 split->ram_bytes = split->len;
705 split->orig_start = split->start;
706 split->block_len = 0;
707 split->block_start = em->block_start;
708 split->orig_block_len = 0;
711 if (extent_map_in_tree(em)) {
712 replace_extent_mapping(em_tree, em, split,
715 ret = add_extent_mapping(em_tree, split,
717 ASSERT(ret == 0); /* Logic error */
719 free_extent_map(split);
723 if (extent_map_in_tree(em))
724 remove_extent_mapping(em_tree, em);
725 write_unlock(&em_tree->lock);
729 /* once for the tree*/
733 free_extent_map(split);
735 free_extent_map(split2);
739 * this is very complex, but the basic idea is to drop all extents
740 * in the range start - end. hint_block is filled in with a block number
741 * that would be a good hint to the block allocator for this file.
743 * If an extent intersects the range but is not entirely inside the range
744 * it is either truncated or split. Anything entirely inside the range
745 * is deleted from the tree.
747 int __btrfs_drop_extents(struct btrfs_trans_handle *trans,
748 struct btrfs_root *root, struct inode *inode,
749 struct btrfs_path *path, u64 start, u64 end,
750 u64 *drop_end, int drop_cache,
752 u32 extent_item_size,
755 struct btrfs_fs_info *fs_info = root->fs_info;
756 struct extent_buffer *leaf;
757 struct btrfs_file_extent_item *fi;
758 struct btrfs_ref ref = { 0 };
759 struct btrfs_key key;
760 struct btrfs_key new_key;
761 u64 ino = btrfs_ino(BTRFS_I(inode));
762 u64 search_start = start;
765 u64 extent_offset = 0;
767 u64 last_end = start;
773 int modify_tree = -1;
776 int leafs_visited = 0;
779 btrfs_drop_extent_cache(BTRFS_I(inode), start, end - 1, 0);
781 if (start >= BTRFS_I(inode)->disk_i_size && !replace_extent)
784 update_refs = (test_bit(BTRFS_ROOT_REF_COWS, &root->state) ||
785 root == fs_info->tree_root);
788 ret = btrfs_lookup_file_extent(trans, root, path, ino,
789 search_start, modify_tree);
792 if (ret > 0 && path->slots[0] > 0 && search_start == start) {
793 leaf = path->nodes[0];
794 btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1);
795 if (key.objectid == ino &&
796 key.type == BTRFS_EXTENT_DATA_KEY)
802 leaf = path->nodes[0];
803 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
805 ret = btrfs_next_leaf(root, path);
813 leaf = path->nodes[0];
817 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
819 if (key.objectid > ino)
821 if (WARN_ON_ONCE(key.objectid < ino) ||
822 key.type < BTRFS_EXTENT_DATA_KEY) {
827 if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= end)
830 fi = btrfs_item_ptr(leaf, path->slots[0],
831 struct btrfs_file_extent_item);
832 extent_type = btrfs_file_extent_type(leaf, fi);
834 if (extent_type == BTRFS_FILE_EXTENT_REG ||
835 extent_type == BTRFS_FILE_EXTENT_PREALLOC) {
836 disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
837 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
838 extent_offset = btrfs_file_extent_offset(leaf, fi);
839 extent_end = key.offset +
840 btrfs_file_extent_num_bytes(leaf, fi);
841 } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
842 extent_end = key.offset +
843 btrfs_file_extent_ram_bytes(leaf, fi);
850 * Don't skip extent items representing 0 byte lengths. They
851 * used to be created (bug) if while punching holes we hit
852 * -ENOSPC condition. So if we find one here, just ensure we
853 * delete it, otherwise we would insert a new file extent item
854 * with the same key (offset) as that 0 bytes length file
855 * extent item in the call to setup_items_for_insert() later
858 if (extent_end == key.offset && extent_end >= search_start) {
859 last_end = extent_end;
860 goto delete_extent_item;
863 if (extent_end <= search_start) {
869 search_start = max(key.offset, start);
870 if (recow || !modify_tree) {
872 btrfs_release_path(path);
877 * | - range to drop - |
878 * | -------- extent -------- |
880 if (start > key.offset && end < extent_end) {
882 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
887 memcpy(&new_key, &key, sizeof(new_key));
888 new_key.offset = start;
889 ret = btrfs_duplicate_item(trans, root, path,
891 if (ret == -EAGAIN) {
892 btrfs_release_path(path);
898 leaf = path->nodes[0];
899 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
900 struct btrfs_file_extent_item);
901 btrfs_set_file_extent_num_bytes(leaf, fi,
904 fi = btrfs_item_ptr(leaf, path->slots[0],
905 struct btrfs_file_extent_item);
907 extent_offset += start - key.offset;
908 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
909 btrfs_set_file_extent_num_bytes(leaf, fi,
911 btrfs_mark_buffer_dirty(leaf);
913 if (update_refs && disk_bytenr > 0) {
914 btrfs_init_generic_ref(&ref,
915 BTRFS_ADD_DELAYED_REF,
916 disk_bytenr, num_bytes, 0);
917 btrfs_init_data_ref(&ref,
918 root->root_key.objectid,
920 start - extent_offset);
921 ret = btrfs_inc_extent_ref(trans, &ref);
922 BUG_ON(ret); /* -ENOMEM */
927 * From here on out we will have actually dropped something, so
928 * last_end can be updated.
930 last_end = extent_end;
933 * | ---- range to drop ----- |
934 * | -------- extent -------- |
936 if (start <= key.offset && end < extent_end) {
937 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
942 memcpy(&new_key, &key, sizeof(new_key));
943 new_key.offset = end;
944 btrfs_set_item_key_safe(fs_info, path, &new_key);
946 extent_offset += end - key.offset;
947 btrfs_set_file_extent_offset(leaf, fi, extent_offset);
948 btrfs_set_file_extent_num_bytes(leaf, fi,
950 btrfs_mark_buffer_dirty(leaf);
951 if (update_refs && disk_bytenr > 0)
952 inode_sub_bytes(inode, end - key.offset);
956 search_start = extent_end;
958 * | ---- range to drop ----- |
959 * | -------- extent -------- |
961 if (start > key.offset && end >= extent_end) {
963 if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
968 btrfs_set_file_extent_num_bytes(leaf, fi,
970 btrfs_mark_buffer_dirty(leaf);
971 if (update_refs && disk_bytenr > 0)
972 inode_sub_bytes(inode, extent_end - start);
973 if (end == extent_end)
981 * | ---- range to drop ----- |
982 * | ------ extent ------ |
984 if (start <= key.offset && end >= extent_end) {
987 del_slot = path->slots[0];
990 BUG_ON(del_slot + del_nr != path->slots[0]);
995 extent_type == BTRFS_FILE_EXTENT_INLINE) {
996 inode_sub_bytes(inode,
997 extent_end - key.offset);
998 extent_end = ALIGN(extent_end,
999 fs_info->sectorsize);
1000 } else if (update_refs && disk_bytenr > 0) {
1001 btrfs_init_generic_ref(&ref,
1002 BTRFS_DROP_DELAYED_REF,
1003 disk_bytenr, num_bytes, 0);
1004 btrfs_init_data_ref(&ref,
1005 root->root_key.objectid,
1007 key.offset - extent_offset);
1008 ret = btrfs_free_extent(trans, &ref);
1009 BUG_ON(ret); /* -ENOMEM */
1010 inode_sub_bytes(inode,
1011 extent_end - key.offset);
1014 if (end == extent_end)
1017 if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) {
1022 ret = btrfs_del_items(trans, root, path, del_slot,
1025 btrfs_abort_transaction(trans, ret);
1032 btrfs_release_path(path);
1039 if (!ret && del_nr > 0) {
1041 * Set path->slots[0] to first slot, so that after the delete
1042 * if items are move off from our leaf to its immediate left or
1043 * right neighbor leafs, we end up with a correct and adjusted
1044 * path->slots[0] for our insertion (if replace_extent != 0).
1046 path->slots[0] = del_slot;
1047 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1049 btrfs_abort_transaction(trans, ret);
1052 leaf = path->nodes[0];
1054 * If btrfs_del_items() was called, it might have deleted a leaf, in
1055 * which case it unlocked our path, so check path->locks[0] matches a
1058 if (!ret && replace_extent && leafs_visited == 1 &&
1059 (path->locks[0] == BTRFS_WRITE_LOCK_BLOCKING ||
1060 path->locks[0] == BTRFS_WRITE_LOCK) &&
1061 btrfs_leaf_free_space(leaf) >=
1062 sizeof(struct btrfs_item) + extent_item_size) {
1065 key.type = BTRFS_EXTENT_DATA_KEY;
1067 if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) {
1068 struct btrfs_key slot_key;
1070 btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]);
1071 if (btrfs_comp_cpu_keys(&key, &slot_key) > 0)
1074 setup_items_for_insert(root, path, &key,
1077 sizeof(struct btrfs_item) +
1078 extent_item_size, 1);
1082 if (!replace_extent || !(*key_inserted))
1083 btrfs_release_path(path);
1085 *drop_end = found ? min(end, last_end) : end;
1089 int btrfs_drop_extents(struct btrfs_trans_handle *trans,
1090 struct btrfs_root *root, struct inode *inode, u64 start,
1091 u64 end, int drop_cache)
1093 struct btrfs_path *path;
1096 path = btrfs_alloc_path();
1099 ret = __btrfs_drop_extents(trans, root, inode, path, start, end, NULL,
1100 drop_cache, 0, 0, NULL);
1101 btrfs_free_path(path);
1105 static int extent_mergeable(struct extent_buffer *leaf, int slot,
1106 u64 objectid, u64 bytenr, u64 orig_offset,
1107 u64 *start, u64 *end)
1109 struct btrfs_file_extent_item *fi;
1110 struct btrfs_key key;
1113 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
1116 btrfs_item_key_to_cpu(leaf, &key, slot);
1117 if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY)
1120 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
1121 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG ||
1122 btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr ||
1123 btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset ||
1124 btrfs_file_extent_compression(leaf, fi) ||
1125 btrfs_file_extent_encryption(leaf, fi) ||
1126 btrfs_file_extent_other_encoding(leaf, fi))
1129 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1130 if ((*start && *start != key.offset) || (*end && *end != extent_end))
1133 *start = key.offset;
1139 * Mark extent in the range start - end as written.
1141 * This changes extent type from 'pre-allocated' to 'regular'. If only
1142 * part of extent is marked as written, the extent will be split into
1145 int btrfs_mark_extent_written(struct btrfs_trans_handle *trans,
1146 struct btrfs_inode *inode, u64 start, u64 end)
1148 struct btrfs_fs_info *fs_info = trans->fs_info;
1149 struct btrfs_root *root = inode->root;
1150 struct extent_buffer *leaf;
1151 struct btrfs_path *path;
1152 struct btrfs_file_extent_item *fi;
1153 struct btrfs_ref ref = { 0 };
1154 struct btrfs_key key;
1155 struct btrfs_key new_key;
1167 u64 ino = btrfs_ino(inode);
1169 path = btrfs_alloc_path();
1176 key.type = BTRFS_EXTENT_DATA_KEY;
1179 ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
1182 if (ret > 0 && path->slots[0] > 0)
1185 leaf = path->nodes[0];
1186 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
1187 if (key.objectid != ino ||
1188 key.type != BTRFS_EXTENT_DATA_KEY) {
1190 btrfs_abort_transaction(trans, ret);
1193 fi = btrfs_item_ptr(leaf, path->slots[0],
1194 struct btrfs_file_extent_item);
1195 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) {
1197 btrfs_abort_transaction(trans, ret);
1200 extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi);
1201 if (key.offset > start || extent_end < end) {
1203 btrfs_abort_transaction(trans, ret);
1207 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1208 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1209 orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi);
1210 memcpy(&new_key, &key, sizeof(new_key));
1212 if (start == key.offset && end < extent_end) {
1215 if (extent_mergeable(leaf, path->slots[0] - 1,
1216 ino, bytenr, orig_offset,
1217 &other_start, &other_end)) {
1218 new_key.offset = end;
1219 btrfs_set_item_key_safe(fs_info, path, &new_key);
1220 fi = btrfs_item_ptr(leaf, path->slots[0],
1221 struct btrfs_file_extent_item);
1222 btrfs_set_file_extent_generation(leaf, fi,
1224 btrfs_set_file_extent_num_bytes(leaf, fi,
1226 btrfs_set_file_extent_offset(leaf, fi,
1228 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1229 struct btrfs_file_extent_item);
1230 btrfs_set_file_extent_generation(leaf, fi,
1232 btrfs_set_file_extent_num_bytes(leaf, fi,
1234 btrfs_mark_buffer_dirty(leaf);
1239 if (start > key.offset && end == extent_end) {
1242 if (extent_mergeable(leaf, path->slots[0] + 1,
1243 ino, bytenr, orig_offset,
1244 &other_start, &other_end)) {
1245 fi = btrfs_item_ptr(leaf, path->slots[0],
1246 struct btrfs_file_extent_item);
1247 btrfs_set_file_extent_num_bytes(leaf, fi,
1248 start - key.offset);
1249 btrfs_set_file_extent_generation(leaf, fi,
1252 new_key.offset = start;
1253 btrfs_set_item_key_safe(fs_info, path, &new_key);
1255 fi = btrfs_item_ptr(leaf, path->slots[0],
1256 struct btrfs_file_extent_item);
1257 btrfs_set_file_extent_generation(leaf, fi,
1259 btrfs_set_file_extent_num_bytes(leaf, fi,
1261 btrfs_set_file_extent_offset(leaf, fi,
1262 start - orig_offset);
1263 btrfs_mark_buffer_dirty(leaf);
1268 while (start > key.offset || end < extent_end) {
1269 if (key.offset == start)
1272 new_key.offset = split;
1273 ret = btrfs_duplicate_item(trans, root, path, &new_key);
1274 if (ret == -EAGAIN) {
1275 btrfs_release_path(path);
1279 btrfs_abort_transaction(trans, ret);
1283 leaf = path->nodes[0];
1284 fi = btrfs_item_ptr(leaf, path->slots[0] - 1,
1285 struct btrfs_file_extent_item);
1286 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1287 btrfs_set_file_extent_num_bytes(leaf, fi,
1288 split - key.offset);
1290 fi = btrfs_item_ptr(leaf, path->slots[0],
1291 struct btrfs_file_extent_item);
1293 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1294 btrfs_set_file_extent_offset(leaf, fi, split - orig_offset);
1295 btrfs_set_file_extent_num_bytes(leaf, fi,
1296 extent_end - split);
1297 btrfs_mark_buffer_dirty(leaf);
1299 btrfs_init_generic_ref(&ref, BTRFS_ADD_DELAYED_REF, bytenr,
1301 btrfs_init_data_ref(&ref, root->root_key.objectid, ino,
1303 ret = btrfs_inc_extent_ref(trans, &ref);
1305 btrfs_abort_transaction(trans, ret);
1309 if (split == start) {
1312 if (start != key.offset) {
1314 btrfs_abort_transaction(trans, ret);
1325 btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr,
1327 btrfs_init_data_ref(&ref, root->root_key.objectid, ino, orig_offset);
1328 if (extent_mergeable(leaf, path->slots[0] + 1,
1329 ino, bytenr, orig_offset,
1330 &other_start, &other_end)) {
1332 btrfs_release_path(path);
1335 extent_end = other_end;
1336 del_slot = path->slots[0] + 1;
1338 ret = btrfs_free_extent(trans, &ref);
1340 btrfs_abort_transaction(trans, ret);
1346 if (extent_mergeable(leaf, path->slots[0] - 1,
1347 ino, bytenr, orig_offset,
1348 &other_start, &other_end)) {
1350 btrfs_release_path(path);
1353 key.offset = other_start;
1354 del_slot = path->slots[0];
1356 ret = btrfs_free_extent(trans, &ref);
1358 btrfs_abort_transaction(trans, ret);
1363 fi = btrfs_item_ptr(leaf, path->slots[0],
1364 struct btrfs_file_extent_item);
1365 btrfs_set_file_extent_type(leaf, fi,
1366 BTRFS_FILE_EXTENT_REG);
1367 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1368 btrfs_mark_buffer_dirty(leaf);
1370 fi = btrfs_item_ptr(leaf, del_slot - 1,
1371 struct btrfs_file_extent_item);
1372 btrfs_set_file_extent_type(leaf, fi,
1373 BTRFS_FILE_EXTENT_REG);
1374 btrfs_set_file_extent_generation(leaf, fi, trans->transid);
1375 btrfs_set_file_extent_num_bytes(leaf, fi,
1376 extent_end - key.offset);
1377 btrfs_mark_buffer_dirty(leaf);
1379 ret = btrfs_del_items(trans, root, path, del_slot, del_nr);
1381 btrfs_abort_transaction(trans, ret);
1386 btrfs_free_path(path);
1391 * on error we return an unlocked page and the error value
1392 * on success we return a locked page and 0
1394 static int prepare_uptodate_page(struct inode *inode,
1395 struct page *page, u64 pos,
1396 bool force_uptodate)
1400 if (((pos & (PAGE_SIZE - 1)) || force_uptodate) &&
1401 !PageUptodate(page)) {
1402 ret = btrfs_readpage(NULL, page);
1406 if (!PageUptodate(page)) {
1410 if (page->mapping != inode->i_mapping) {
1419 * this just gets pages into the page cache and locks them down.
1421 static noinline int prepare_pages(struct inode *inode, struct page **pages,
1422 size_t num_pages, loff_t pos,
1423 size_t write_bytes, bool force_uptodate)
1426 unsigned long index = pos >> PAGE_SHIFT;
1427 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
1431 for (i = 0; i < num_pages; i++) {
1433 pages[i] = find_or_create_page(inode->i_mapping, index + i,
1434 mask | __GFP_WRITE);
1442 err = prepare_uptodate_page(inode, pages[i], pos,
1444 if (!err && i == num_pages - 1)
1445 err = prepare_uptodate_page(inode, pages[i],
1446 pos + write_bytes, false);
1449 if (err == -EAGAIN) {
1456 wait_on_page_writeback(pages[i]);
1461 while (faili >= 0) {
1462 unlock_page(pages[faili]);
1463 put_page(pages[faili]);
1471 * This function locks the extent and properly waits for data=ordered extents
1472 * to finish before allowing the pages to be modified if need.
1475 * 1 - the extent is locked
1476 * 0 - the extent is not locked, and everything is OK
1477 * -EAGAIN - need re-prepare the pages
1478 * the other < 0 number - Something wrong happens
1481 lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages,
1482 size_t num_pages, loff_t pos,
1484 u64 *lockstart, u64 *lockend,
1485 struct extent_state **cached_state)
1487 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1493 start_pos = round_down(pos, fs_info->sectorsize);
1494 last_pos = start_pos
1495 + round_up(pos + write_bytes - start_pos,
1496 fs_info->sectorsize) - 1;
1498 if (start_pos < inode->vfs_inode.i_size) {
1499 struct btrfs_ordered_extent *ordered;
1501 lock_extent_bits(&inode->io_tree, start_pos, last_pos,
1503 ordered = btrfs_lookup_ordered_range(inode, start_pos,
1504 last_pos - start_pos + 1);
1506 ordered->file_offset + ordered->len > start_pos &&
1507 ordered->file_offset <= last_pos) {
1508 unlock_extent_cached(&inode->io_tree, start_pos,
1509 last_pos, cached_state);
1510 for (i = 0; i < num_pages; i++) {
1511 unlock_page(pages[i]);
1514 btrfs_start_ordered_extent(&inode->vfs_inode,
1516 btrfs_put_ordered_extent(ordered);
1520 btrfs_put_ordered_extent(ordered);
1522 *lockstart = start_pos;
1523 *lockend = last_pos;
1528 * It's possible the pages are dirty right now, but we don't want
1529 * to clean them yet because copy_from_user may catch a page fault
1530 * and we might have to fall back to one page at a time. If that
1531 * happens, we'll unlock these pages and we'd have a window where
1532 * reclaim could sneak in and drop the once-dirty page on the floor
1533 * without writing it.
1535 * We have the pages locked and the extent range locked, so there's
1536 * no way someone can start IO on any dirty pages in this range.
1538 * We'll call btrfs_dirty_pages() later on, and that will flip around
1539 * delalloc bits and dirty the pages as required.
1541 for (i = 0; i < num_pages; i++) {
1542 set_page_extent_mapped(pages[i]);
1543 WARN_ON(!PageLocked(pages[i]));
1549 static noinline int check_can_nocow(struct btrfs_inode *inode, loff_t pos,
1550 size_t *write_bytes)
1552 struct btrfs_fs_info *fs_info = inode->root->fs_info;
1553 struct btrfs_root *root = inode->root;
1554 u64 lockstart, lockend;
1558 ret = btrfs_start_write_no_snapshotting(root);
1562 lockstart = round_down(pos, fs_info->sectorsize);
1563 lockend = round_up(pos + *write_bytes,
1564 fs_info->sectorsize) - 1;
1566 btrfs_lock_and_flush_ordered_range(&inode->io_tree, inode, lockstart,
1569 num_bytes = lockend - lockstart + 1;
1570 ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes,
1574 btrfs_end_write_no_snapshotting(root);
1576 *write_bytes = min_t(size_t, *write_bytes ,
1577 num_bytes - pos + lockstart);
1580 unlock_extent(&inode->io_tree, lockstart, lockend);
1585 static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
1588 struct file *file = iocb->ki_filp;
1589 loff_t pos = iocb->ki_pos;
1590 struct inode *inode = file_inode(file);
1591 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1592 struct btrfs_root *root = BTRFS_I(inode)->root;
1593 struct page **pages = NULL;
1594 struct extent_state *cached_state = NULL;
1595 struct extent_changeset *data_reserved = NULL;
1596 u64 release_bytes = 0;
1599 size_t num_written = 0;
1602 bool only_release_metadata = false;
1603 bool force_page_uptodate = false;
1605 nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE),
1606 PAGE_SIZE / (sizeof(struct page *)));
1607 nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied);
1608 nrptrs = max(nrptrs, 8);
1609 pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL);
1613 while (iov_iter_count(i) > 0) {
1614 size_t offset = offset_in_page(pos);
1615 size_t sector_offset;
1616 size_t write_bytes = min(iov_iter_count(i),
1617 nrptrs * (size_t)PAGE_SIZE -
1619 size_t num_pages = DIV_ROUND_UP(write_bytes + offset,
1621 size_t reserve_bytes;
1624 size_t dirty_sectors;
1628 WARN_ON(num_pages > nrptrs);
1631 * Fault pages before locking them in prepare_pages
1632 * to avoid recursive lock
1634 if (unlikely(iov_iter_fault_in_readable(i, write_bytes))) {
1639 sector_offset = pos & (fs_info->sectorsize - 1);
1640 reserve_bytes = round_up(write_bytes + sector_offset,
1641 fs_info->sectorsize);
1643 extent_changeset_release(data_reserved);
1644 ret = btrfs_check_data_free_space(inode, &data_reserved, pos,
1647 if ((BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1648 BTRFS_INODE_PREALLOC)) &&
1649 check_can_nocow(BTRFS_I(inode), pos,
1650 &write_bytes) > 0) {
1652 * For nodata cow case, no need to reserve
1655 only_release_metadata = true;
1657 * our prealloc extent may be smaller than
1658 * write_bytes, so scale down.
1660 num_pages = DIV_ROUND_UP(write_bytes + offset,
1662 reserve_bytes = round_up(write_bytes +
1664 fs_info->sectorsize);
1670 WARN_ON(reserve_bytes == 0);
1671 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
1674 if (!only_release_metadata)
1675 btrfs_free_reserved_data_space(inode,
1679 btrfs_end_write_no_snapshotting(root);
1683 release_bytes = reserve_bytes;
1686 * This is going to setup the pages array with the number of
1687 * pages we want, so we don't really need to worry about the
1688 * contents of pages from loop to loop
1690 ret = prepare_pages(inode, pages, num_pages,
1692 force_page_uptodate);
1694 btrfs_delalloc_release_extents(BTRFS_I(inode),
1695 reserve_bytes, true);
1699 extents_locked = lock_and_cleanup_extent_if_need(
1700 BTRFS_I(inode), pages,
1701 num_pages, pos, write_bytes, &lockstart,
1702 &lockend, &cached_state);
1703 if (extents_locked < 0) {
1704 if (extents_locked == -EAGAIN)
1706 btrfs_delalloc_release_extents(BTRFS_I(inode),
1707 reserve_bytes, true);
1708 ret = extents_locked;
1712 copied = btrfs_copy_from_user(pos, write_bytes, pages, i);
1714 num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes);
1715 dirty_sectors = round_up(copied + sector_offset,
1716 fs_info->sectorsize);
1717 dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors);
1720 * if we have trouble faulting in the pages, fall
1721 * back to one page at a time
1723 if (copied < write_bytes)
1727 force_page_uptodate = true;
1731 force_page_uptodate = false;
1732 dirty_pages = DIV_ROUND_UP(copied + offset,
1736 if (num_sectors > dirty_sectors) {
1737 /* release everything except the sectors we dirtied */
1738 release_bytes -= dirty_sectors <<
1739 fs_info->sb->s_blocksize_bits;
1740 if (only_release_metadata) {
1741 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1742 release_bytes, true);
1746 __pos = round_down(pos,
1747 fs_info->sectorsize) +
1748 (dirty_pages << PAGE_SHIFT);
1749 btrfs_delalloc_release_space(inode,
1750 data_reserved, __pos,
1751 release_bytes, true);
1755 release_bytes = round_up(copied + sector_offset,
1756 fs_info->sectorsize);
1759 ret = btrfs_dirty_pages(inode, pages, dirty_pages,
1760 pos, copied, &cached_state);
1762 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
1763 lockstart, lockend, &cached_state);
1764 btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes,
1767 btrfs_drop_pages(pages, num_pages);
1772 if (only_release_metadata)
1773 btrfs_end_write_no_snapshotting(root);
1775 if (only_release_metadata && copied > 0) {
1776 lockstart = round_down(pos,
1777 fs_info->sectorsize);
1778 lockend = round_up(pos + copied,
1779 fs_info->sectorsize) - 1;
1781 set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
1782 lockend, EXTENT_NORESERVE, NULL,
1784 only_release_metadata = false;
1787 btrfs_drop_pages(pages, num_pages);
1791 balance_dirty_pages_ratelimited(inode->i_mapping);
1792 if (dirty_pages < (fs_info->nodesize >> PAGE_SHIFT) + 1)
1793 btrfs_btree_balance_dirty(fs_info);
1796 num_written += copied;
1801 if (release_bytes) {
1802 if (only_release_metadata) {
1803 btrfs_end_write_no_snapshotting(root);
1804 btrfs_delalloc_release_metadata(BTRFS_I(inode),
1805 release_bytes, true);
1807 btrfs_delalloc_release_space(inode, data_reserved,
1808 round_down(pos, fs_info->sectorsize),
1809 release_bytes, true);
1813 extent_changeset_free(data_reserved);
1814 return num_written ? num_written : ret;
1817 static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
1819 struct file *file = iocb->ki_filp;
1820 struct inode *inode = file_inode(file);
1823 ssize_t written_buffered;
1827 written = generic_file_direct_write(iocb, from);
1829 if (written < 0 || !iov_iter_count(from))
1833 written_buffered = btrfs_buffered_write(iocb, from);
1834 if (written_buffered < 0) {
1835 err = written_buffered;
1839 * Ensure all data is persisted. We want the next direct IO read to be
1840 * able to read what was just written.
1842 endbyte = pos + written_buffered - 1;
1843 err = btrfs_fdatawrite_range(inode, pos, endbyte);
1846 err = filemap_fdatawait_range(inode->i_mapping, pos, endbyte);
1849 written += written_buffered;
1850 iocb->ki_pos = pos + written_buffered;
1851 invalidate_mapping_pages(file->f_mapping, pos >> PAGE_SHIFT,
1852 endbyte >> PAGE_SHIFT);
1854 return written ? written : err;
1857 static void update_time_for_write(struct inode *inode)
1859 struct timespec64 now;
1861 if (IS_NOCMTIME(inode))
1864 now = current_time(inode);
1865 if (!timespec64_equal(&inode->i_mtime, &now))
1866 inode->i_mtime = now;
1868 if (!timespec64_equal(&inode->i_ctime, &now))
1869 inode->i_ctime = now;
1871 if (IS_I_VERSION(inode))
1872 inode_inc_iversion(inode);
1875 static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
1876 struct iov_iter *from)
1878 struct file *file = iocb->ki_filp;
1879 struct inode *inode = file_inode(file);
1880 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
1881 struct btrfs_root *root = BTRFS_I(inode)->root;
1884 ssize_t num_written = 0;
1885 bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
1888 size_t count = iov_iter_count(from);
1892 if (!(iocb->ki_flags & IOCB_DIRECT) &&
1893 (iocb->ki_flags & IOCB_NOWAIT))
1896 if (!inode_trylock(inode)) {
1897 if (iocb->ki_flags & IOCB_NOWAIT)
1902 err = generic_write_checks(iocb, from);
1904 inode_unlock(inode);
1909 if (iocb->ki_flags & IOCB_NOWAIT) {
1911 * We will allocate space in case nodatacow is not set,
1914 if (!(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW |
1915 BTRFS_INODE_PREALLOC)) ||
1916 check_can_nocow(BTRFS_I(inode), pos, &count) <= 0) {
1917 inode_unlock(inode);
1922 current->backing_dev_info = inode_to_bdi(inode);
1923 err = file_remove_privs(file);
1925 inode_unlock(inode);
1930 * If BTRFS flips readonly due to some impossible error
1931 * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
1932 * although we have opened a file as writable, we have
1933 * to stop this write operation to ensure FS consistency.
1935 if (test_bit(BTRFS_FS_STATE_ERROR, &fs_info->fs_state)) {
1936 inode_unlock(inode);
1942 * We reserve space for updating the inode when we reserve space for the
1943 * extent we are going to write, so we will enospc out there. We don't
1944 * need to start yet another transaction to update the inode as we will
1945 * update the inode when we finish writing whatever data we write.
1947 update_time_for_write(inode);
1949 start_pos = round_down(pos, fs_info->sectorsize);
1950 oldsize = i_size_read(inode);
1951 if (start_pos > oldsize) {
1952 /* Expand hole size to cover write data, preventing empty gap */
1953 end_pos = round_up(pos + count,
1954 fs_info->sectorsize);
1955 err = btrfs_cont_expand(inode, oldsize, end_pos);
1957 inode_unlock(inode);
1960 if (start_pos > round_up(oldsize, fs_info->sectorsize))
1965 atomic_inc(&BTRFS_I(inode)->sync_writers);
1967 if (iocb->ki_flags & IOCB_DIRECT) {
1968 num_written = __btrfs_direct_write(iocb, from);
1970 num_written = btrfs_buffered_write(iocb, from);
1971 if (num_written > 0)
1972 iocb->ki_pos = pos + num_written;
1974 pagecache_isize_extended(inode, oldsize,
1975 i_size_read(inode));
1978 inode_unlock(inode);
1981 * We also have to set last_sub_trans to the current log transid,
1982 * otherwise subsequent syncs to a file that's been synced in this
1983 * transaction will appear to have already occurred.
1985 spin_lock(&BTRFS_I(inode)->lock);
1986 BTRFS_I(inode)->last_sub_trans = root->log_transid;
1987 spin_unlock(&BTRFS_I(inode)->lock);
1988 if (num_written > 0)
1989 num_written = generic_write_sync(iocb, num_written);
1992 atomic_dec(&BTRFS_I(inode)->sync_writers);
1994 current->backing_dev_info = NULL;
1995 return num_written ? num_written : err;
1998 int btrfs_release_file(struct inode *inode, struct file *filp)
2000 struct btrfs_file_private *private = filp->private_data;
2002 if (private && private->filldir_buf)
2003 kfree(private->filldir_buf);
2005 filp->private_data = NULL;
2008 * ordered_data_close is set by setattr when we are about to truncate
2009 * a file from a non-zero size to a zero size. This tries to
2010 * flush down new bytes that may have been written if the
2011 * application were using truncate to replace a file in place.
2013 if (test_and_clear_bit(BTRFS_INODE_ORDERED_DATA_CLOSE,
2014 &BTRFS_I(inode)->runtime_flags))
2015 filemap_flush(inode->i_mapping);
2019 static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
2022 struct blk_plug plug;
2025 * This is only called in fsync, which would do synchronous writes, so
2026 * a plug can merge adjacent IOs as much as possible. Esp. in case of
2027 * multiple disks using raid profile, a large IO can be split to
2028 * several segments of stripe length (currently 64K).
2030 blk_start_plug(&plug);
2031 atomic_inc(&BTRFS_I(inode)->sync_writers);
2032 ret = btrfs_fdatawrite_range(inode, start, end);
2033 atomic_dec(&BTRFS_I(inode)->sync_writers);
2034 blk_finish_plug(&plug);
2040 * fsync call for both files and directories. This logs the inode into
2041 * the tree log instead of forcing full commits whenever possible.
2043 * It needs to call filemap_fdatawait so that all ordered extent updates are
2044 * in the metadata btree are up to date for copying to the log.
2046 * It drops the inode mutex before doing the tree log commit. This is an
2047 * important optimization for directories because holding the mutex prevents
2048 * new operations on the dir while we write to disk.
2050 int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync)
2052 struct dentry *dentry = file_dentry(file);
2053 struct inode *inode = d_inode(dentry);
2054 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2055 struct btrfs_root *root = BTRFS_I(inode)->root;
2056 struct btrfs_trans_handle *trans;
2057 struct btrfs_log_ctx ctx;
2062 * If the inode needs a full sync, make sure we use a full range to
2063 * avoid log tree corruption, due to hole detection racing with ordered
2064 * extent completion for adjacent ranges, and assertion failures during
2067 if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2068 &BTRFS_I(inode)->runtime_flags)) {
2074 * The range length can be represented by u64, we have to do the typecasts
2075 * to avoid signed overflow if it's [0, LLONG_MAX] eg. from fsync()
2077 len = (u64)end - (u64)start + 1;
2078 trace_btrfs_sync_file(file, datasync);
2080 btrfs_init_log_ctx(&ctx, inode);
2083 * We write the dirty pages in the range and wait until they complete
2084 * out of the ->i_mutex. If so, we can flush the dirty pages by
2085 * multi-task, and make the performance up. See
2086 * btrfs_wait_ordered_range for an explanation of the ASYNC check.
2088 ret = start_ordered_ops(inode, start, end);
2095 * We take the dio_sem here because the tree log stuff can race with
2096 * lockless dio writes and get an extent map logged for an extent we
2097 * never waited on. We need it this high up for lockdep reasons.
2099 down_write(&BTRFS_I(inode)->dio_sem);
2101 atomic_inc(&root->log_batch);
2104 * Before we acquired the inode's lock, someone may have dirtied more
2105 * pages in the target range. We need to make sure that writeback for
2106 * any such pages does not start while we are logging the inode, because
2107 * if it does, any of the following might happen when we are not doing a
2110 * 1) We log an extent after its writeback finishes but before its
2111 * checksums are added to the csum tree, leading to -EIO errors
2112 * when attempting to read the extent after a log replay.
2114 * 2) We can end up logging an extent before its writeback finishes.
2115 * Therefore after the log replay we will have a file extent item
2116 * pointing to an unwritten extent (and no data checksums as well).
2118 * So trigger writeback for any eventual new dirty pages and then we
2119 * wait for all ordered extents to complete below.
2121 ret = start_ordered_ops(inode, start, end);
2123 inode_unlock(inode);
2128 * We have to do this here to avoid the priority inversion of waiting on
2129 * IO of a lower priority task while holding a transaction open.
2131 ret = btrfs_wait_ordered_range(inode, start, len);
2133 up_write(&BTRFS_I(inode)->dio_sem);
2134 inode_unlock(inode);
2137 atomic_inc(&root->log_batch);
2140 if (btrfs_inode_in_log(BTRFS_I(inode), fs_info->generation) ||
2141 BTRFS_I(inode)->last_trans <= fs_info->last_trans_committed) {
2143 * We've had everything committed since the last time we were
2144 * modified so clear this flag in case it was set for whatever
2145 * reason, it's no longer relevant.
2147 clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2148 &BTRFS_I(inode)->runtime_flags);
2150 * An ordered extent might have started before and completed
2151 * already with io errors, in which case the inode was not
2152 * updated and we end up here. So check the inode's mapping
2153 * for any errors that might have happened since we last
2154 * checked called fsync.
2156 ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err);
2157 up_write(&BTRFS_I(inode)->dio_sem);
2158 inode_unlock(inode);
2163 * We use start here because we will need to wait on the IO to complete
2164 * in btrfs_sync_log, which could require joining a transaction (for
2165 * example checking cross references in the nocow path). If we use join
2166 * here we could get into a situation where we're waiting on IO to
2167 * happen that is blocked on a transaction trying to commit. With start
2168 * we inc the extwriter counter, so we wait for all extwriters to exit
2169 * before we start blocking joiners. This comment is to keep somebody
2170 * from thinking they are super smart and changing this to
2171 * btrfs_join_transaction *cough*Josef*cough*.
2173 trans = btrfs_start_transaction(root, 0);
2174 if (IS_ERR(trans)) {
2175 ret = PTR_ERR(trans);
2176 up_write(&BTRFS_I(inode)->dio_sem);
2177 inode_unlock(inode);
2181 ret = btrfs_log_dentry_safe(trans, dentry, start, end, &ctx);
2183 /* Fallthrough and commit/free transaction. */
2187 /* we've logged all the items and now have a consistent
2188 * version of the file in the log. It is possible that
2189 * someone will come in and modify the file, but that's
2190 * fine because the log is consistent on disk, and we
2191 * have references to all of the file's extents
2193 * It is possible that someone will come in and log the
2194 * file again, but that will end up using the synchronization
2195 * inside btrfs_sync_log to keep things safe.
2197 up_write(&BTRFS_I(inode)->dio_sem);
2198 inode_unlock(inode);
2200 if (ret != BTRFS_NO_LOG_SYNC) {
2202 ret = btrfs_sync_log(trans, root, &ctx);
2204 ret = btrfs_end_transaction(trans);
2208 ret = btrfs_commit_transaction(trans);
2210 ret = btrfs_end_transaction(trans);
2213 ASSERT(list_empty(&ctx.list));
2214 err = file_check_and_advance_wb_err(file);
2217 return ret > 0 ? -EIO : ret;
2220 static const struct vm_operations_struct btrfs_file_vm_ops = {
2221 .fault = filemap_fault,
2222 .map_pages = filemap_map_pages,
2223 .page_mkwrite = btrfs_page_mkwrite,
2226 static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma)
2228 struct address_space *mapping = filp->f_mapping;
2230 if (!mapping->a_ops->readpage)
2233 file_accessed(filp);
2234 vma->vm_ops = &btrfs_file_vm_ops;
2239 static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf,
2240 int slot, u64 start, u64 end)
2242 struct btrfs_file_extent_item *fi;
2243 struct btrfs_key key;
2245 if (slot < 0 || slot >= btrfs_header_nritems(leaf))
2248 btrfs_item_key_to_cpu(leaf, &key, slot);
2249 if (key.objectid != btrfs_ino(inode) ||
2250 key.type != BTRFS_EXTENT_DATA_KEY)
2253 fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
2255 if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG)
2258 if (btrfs_file_extent_disk_bytenr(leaf, fi))
2261 if (key.offset == end)
2263 if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start)
2268 static int fill_holes(struct btrfs_trans_handle *trans,
2269 struct btrfs_inode *inode,
2270 struct btrfs_path *path, u64 offset, u64 end)
2272 struct btrfs_fs_info *fs_info = trans->fs_info;
2273 struct btrfs_root *root = inode->root;
2274 struct extent_buffer *leaf;
2275 struct btrfs_file_extent_item *fi;
2276 struct extent_map *hole_em;
2277 struct extent_map_tree *em_tree = &inode->extent_tree;
2278 struct btrfs_key key;
2281 if (btrfs_fs_incompat(fs_info, NO_HOLES))
2284 key.objectid = btrfs_ino(inode);
2285 key.type = BTRFS_EXTENT_DATA_KEY;
2286 key.offset = offset;
2288 ret = btrfs_search_slot(trans, root, &key, path, 0, 1);
2291 * We should have dropped this offset, so if we find it then
2292 * something has gone horribly wrong.
2299 leaf = path->nodes[0];
2300 if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) {
2304 fi = btrfs_item_ptr(leaf, path->slots[0],
2305 struct btrfs_file_extent_item);
2306 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) +
2308 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2309 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2310 btrfs_set_file_extent_offset(leaf, fi, 0);
2311 btrfs_mark_buffer_dirty(leaf);
2315 if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) {
2318 key.offset = offset;
2319 btrfs_set_item_key_safe(fs_info, path, &key);
2320 fi = btrfs_item_ptr(leaf, path->slots[0],
2321 struct btrfs_file_extent_item);
2322 num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end -
2324 btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes);
2325 btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes);
2326 btrfs_set_file_extent_offset(leaf, fi, 0);
2327 btrfs_mark_buffer_dirty(leaf);
2330 btrfs_release_path(path);
2332 ret = btrfs_insert_file_extent(trans, root, btrfs_ino(inode),
2333 offset, 0, 0, end - offset, 0, end - offset, 0, 0, 0);
2338 btrfs_release_path(path);
2340 hole_em = alloc_extent_map();
2342 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2343 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags);
2345 hole_em->start = offset;
2346 hole_em->len = end - offset;
2347 hole_em->ram_bytes = hole_em->len;
2348 hole_em->orig_start = offset;
2350 hole_em->block_start = EXTENT_MAP_HOLE;
2351 hole_em->block_len = 0;
2352 hole_em->orig_block_len = 0;
2353 hole_em->bdev = fs_info->fs_devices->latest_bdev;
2354 hole_em->compress_type = BTRFS_COMPRESS_NONE;
2355 hole_em->generation = trans->transid;
2358 btrfs_drop_extent_cache(inode, offset, end - 1, 0);
2359 write_lock(&em_tree->lock);
2360 ret = add_extent_mapping(em_tree, hole_em, 1);
2361 write_unlock(&em_tree->lock);
2362 } while (ret == -EEXIST);
2363 free_extent_map(hole_em);
2365 set_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
2366 &inode->runtime_flags);
2373 * Find a hole extent on given inode and change start/len to the end of hole
2374 * extent.(hole/vacuum extent whose em->start <= start &&
2375 * em->start + em->len > start)
2376 * When a hole extent is found, return 1 and modify start/len.
2378 static int find_first_non_hole(struct inode *inode, u64 *start, u64 *len)
2380 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2381 struct extent_map *em;
2384 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2385 round_down(*start, fs_info->sectorsize),
2386 round_up(*len, fs_info->sectorsize), 0);
2390 /* Hole or vacuum extent(only exists in no-hole mode) */
2391 if (em->block_start == EXTENT_MAP_HOLE) {
2393 *len = em->start + em->len > *start + *len ?
2394 0 : *start + *len - em->start - em->len;
2395 *start = em->start + em->len;
2397 free_extent_map(em);
2401 static int btrfs_punch_hole_lock_range(struct inode *inode,
2402 const u64 lockstart,
2404 struct extent_state **cached_state)
2407 struct btrfs_ordered_extent *ordered;
2410 truncate_pagecache_range(inode, lockstart, lockend);
2412 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2414 ordered = btrfs_lookup_first_ordered_extent(inode, lockend);
2417 * We need to make sure we have no ordered extents in this range
2418 * and nobody raced in and read a page in this range, if we did
2419 * we need to try again.
2422 (ordered->file_offset + ordered->len <= lockstart ||
2423 ordered->file_offset > lockend)) &&
2424 !filemap_range_has_page(inode->i_mapping,
2425 lockstart, lockend)) {
2427 btrfs_put_ordered_extent(ordered);
2431 btrfs_put_ordered_extent(ordered);
2432 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2433 lockend, cached_state);
2434 ret = btrfs_wait_ordered_range(inode, lockstart,
2435 lockend - lockstart + 1);
2442 static int btrfs_punch_hole(struct inode *inode, loff_t offset, loff_t len)
2444 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
2445 struct btrfs_root *root = BTRFS_I(inode)->root;
2446 struct extent_state *cached_state = NULL;
2447 struct btrfs_path *path;
2448 struct btrfs_block_rsv *rsv;
2449 struct btrfs_trans_handle *trans;
2454 u64 orig_start = offset;
2456 u64 min_size = btrfs_calc_trans_metadata_size(fs_info, 1);
2460 unsigned int rsv_count;
2462 bool no_holes = btrfs_fs_incompat(fs_info, NO_HOLES);
2464 bool truncated_block = false;
2465 bool updated_inode = false;
2467 ret = btrfs_wait_ordered_range(inode, offset, len);
2472 ino_size = round_up(inode->i_size, fs_info->sectorsize);
2473 ret = find_first_non_hole(inode, &offset, &len);
2475 goto out_only_mutex;
2477 /* Already in a large hole */
2479 goto out_only_mutex;
2482 lockstart = round_up(offset, btrfs_inode_sectorsize(inode));
2483 lockend = round_down(offset + len,
2484 btrfs_inode_sectorsize(inode)) - 1;
2485 same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset))
2486 == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1));
2488 * We needn't truncate any block which is beyond the end of the file
2489 * because we are sure there is no data there.
2492 * Only do this if we are in the same block and we aren't doing the
2495 if (same_block && len < fs_info->sectorsize) {
2496 if (offset < ino_size) {
2497 truncated_block = true;
2498 ret = btrfs_truncate_block(inode, offset, len, 0);
2502 goto out_only_mutex;
2505 /* zero back part of the first block */
2506 if (offset < ino_size) {
2507 truncated_block = true;
2508 ret = btrfs_truncate_block(inode, offset, 0, 0);
2510 inode_unlock(inode);
2515 /* Check the aligned pages after the first unaligned page,
2516 * if offset != orig_start, which means the first unaligned page
2517 * including several following pages are already in holes,
2518 * the extra check can be skipped */
2519 if (offset == orig_start) {
2520 /* after truncate page, check hole again */
2521 len = offset + len - lockstart;
2523 ret = find_first_non_hole(inode, &offset, &len);
2525 goto out_only_mutex;
2528 goto out_only_mutex;
2533 /* Check the tail unaligned part is in a hole */
2534 tail_start = lockend + 1;
2535 tail_len = offset + len - tail_start;
2537 ret = find_first_non_hole(inode, &tail_start, &tail_len);
2538 if (unlikely(ret < 0))
2539 goto out_only_mutex;
2541 /* zero the front end of the last page */
2542 if (tail_start + tail_len < ino_size) {
2543 truncated_block = true;
2544 ret = btrfs_truncate_block(inode,
2545 tail_start + tail_len,
2548 goto out_only_mutex;
2553 if (lockend < lockstart) {
2555 goto out_only_mutex;
2558 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
2561 goto out_only_mutex;
2563 path = btrfs_alloc_path();
2569 rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP);
2574 rsv->size = btrfs_calc_trans_metadata_size(fs_info, 1);
2578 * 1 - update the inode
2579 * 1 - removing the extents in the range
2580 * 1 - adding the hole extent if no_holes isn't set
2582 rsv_count = no_holes ? 2 : 3;
2583 trans = btrfs_start_transaction(root, rsv_count);
2584 if (IS_ERR(trans)) {
2585 err = PTR_ERR(trans);
2589 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv,
2592 trans->block_rsv = rsv;
2594 cur_offset = lockstart;
2595 len = lockend - cur_offset;
2596 while (cur_offset < lockend) {
2597 ret = __btrfs_drop_extents(trans, root, inode, path,
2598 cur_offset, lockend + 1,
2599 &drop_end, 1, 0, 0, NULL);
2603 trans->block_rsv = &fs_info->trans_block_rsv;
2605 if (cur_offset < drop_end && cur_offset < ino_size) {
2606 ret = fill_holes(trans, BTRFS_I(inode), path,
2607 cur_offset, drop_end);
2610 * If we failed then we didn't insert our hole
2611 * entries for the area we dropped, so now the
2612 * fs is corrupted, so we must abort the
2615 btrfs_abort_transaction(trans, ret);
2621 cur_offset = drop_end;
2623 ret = btrfs_update_inode(trans, root, inode);
2629 btrfs_end_transaction(trans);
2630 btrfs_btree_balance_dirty(fs_info);
2632 trans = btrfs_start_transaction(root, rsv_count);
2633 if (IS_ERR(trans)) {
2634 ret = PTR_ERR(trans);
2639 ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv,
2640 rsv, min_size, false);
2641 BUG_ON(ret); /* shouldn't happen */
2642 trans->block_rsv = rsv;
2644 ret = find_first_non_hole(inode, &cur_offset, &len);
2645 if (unlikely(ret < 0))
2658 trans->block_rsv = &fs_info->trans_block_rsv;
2660 * If we are using the NO_HOLES feature we might have had already an
2661 * hole that overlaps a part of the region [lockstart, lockend] and
2662 * ends at (or beyond) lockend. Since we have no file extent items to
2663 * represent holes, drop_end can be less than lockend and so we must
2664 * make sure we have an extent map representing the existing hole (the
2665 * call to __btrfs_drop_extents() might have dropped the existing extent
2666 * map representing the existing hole), otherwise the fast fsync path
2667 * will not record the existence of the hole region
2668 * [existing_hole_start, lockend].
2670 if (drop_end <= lockend)
2671 drop_end = lockend + 1;
2673 * Don't insert file hole extent item if it's for a range beyond eof
2674 * (because it's useless) or if it represents a 0 bytes range (when
2675 * cur_offset == drop_end).
2677 if (cur_offset < ino_size && cur_offset < drop_end) {
2678 ret = fill_holes(trans, BTRFS_I(inode), path,
2679 cur_offset, drop_end);
2681 /* Same comment as above. */
2682 btrfs_abort_transaction(trans, ret);
2692 inode_inc_iversion(inode);
2693 inode->i_mtime = inode->i_ctime = current_time(inode);
2695 trans->block_rsv = &fs_info->trans_block_rsv;
2696 ret = btrfs_update_inode(trans, root, inode);
2697 updated_inode = true;
2698 btrfs_end_transaction(trans);
2699 btrfs_btree_balance_dirty(fs_info);
2701 btrfs_free_path(path);
2702 btrfs_free_block_rsv(fs_info, rsv);
2704 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
2707 if (!updated_inode && truncated_block && !ret && !err) {
2709 * If we only end up zeroing part of a page, we still need to
2710 * update the inode item, so that all the time fields are
2711 * updated as well as the necessary btrfs inode in memory fields
2712 * for detecting, at fsync time, if the inode isn't yet in the
2713 * log tree or it's there but not up to date.
2715 struct timespec64 now = current_time(inode);
2717 inode_inc_iversion(inode);
2718 inode->i_mtime = now;
2719 inode->i_ctime = now;
2720 trans = btrfs_start_transaction(root, 1);
2721 if (IS_ERR(trans)) {
2722 err = PTR_ERR(trans);
2724 err = btrfs_update_inode(trans, root, inode);
2725 ret = btrfs_end_transaction(trans);
2728 inode_unlock(inode);
2734 /* Helper structure to record which range is already reserved */
2735 struct falloc_range {
2736 struct list_head list;
2742 * Helper function to add falloc range
2744 * Caller should have locked the larger range of extent containing
2747 static int add_falloc_range(struct list_head *head, u64 start, u64 len)
2749 struct falloc_range *prev = NULL;
2750 struct falloc_range *range = NULL;
2752 if (list_empty(head))
2756 * As fallocate iterate by bytenr order, we only need to check
2759 prev = list_entry(head->prev, struct falloc_range, list);
2760 if (prev->start + prev->len == start) {
2765 range = kmalloc(sizeof(*range), GFP_KERNEL);
2768 range->start = start;
2770 list_add_tail(&range->list, head);
2774 static int btrfs_fallocate_update_isize(struct inode *inode,
2778 struct btrfs_trans_handle *trans;
2779 struct btrfs_root *root = BTRFS_I(inode)->root;
2783 if (mode & FALLOC_FL_KEEP_SIZE || end <= i_size_read(inode))
2786 trans = btrfs_start_transaction(root, 1);
2788 return PTR_ERR(trans);
2790 inode->i_ctime = current_time(inode);
2791 i_size_write(inode, end);
2792 btrfs_ordered_update_i_size(inode, end, NULL);
2793 ret = btrfs_update_inode(trans, root, inode);
2794 ret2 = btrfs_end_transaction(trans);
2796 return ret ? ret : ret2;
2800 RANGE_BOUNDARY_WRITTEN_EXTENT,
2801 RANGE_BOUNDARY_PREALLOC_EXTENT,
2802 RANGE_BOUNDARY_HOLE,
2805 static int btrfs_zero_range_check_range_boundary(struct inode *inode,
2808 const u64 sectorsize = btrfs_inode_sectorsize(inode);
2809 struct extent_map *em;
2812 offset = round_down(offset, sectorsize);
2813 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, offset, sectorsize, 0);
2817 if (em->block_start == EXTENT_MAP_HOLE)
2818 ret = RANGE_BOUNDARY_HOLE;
2819 else if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
2820 ret = RANGE_BOUNDARY_PREALLOC_EXTENT;
2822 ret = RANGE_BOUNDARY_WRITTEN_EXTENT;
2824 free_extent_map(em);
2828 static int btrfs_zero_range(struct inode *inode,
2833 struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info;
2834 struct extent_map *em;
2835 struct extent_changeset *data_reserved = NULL;
2838 const u64 sectorsize = btrfs_inode_sectorsize(inode);
2839 u64 alloc_start = round_down(offset, sectorsize);
2840 u64 alloc_end = round_up(offset + len, sectorsize);
2841 u64 bytes_to_reserve = 0;
2842 bool space_reserved = false;
2844 inode_dio_wait(inode);
2846 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2847 alloc_start, alloc_end - alloc_start, 0);
2854 * Avoid hole punching and extent allocation for some cases. More cases
2855 * could be considered, but these are unlikely common and we keep things
2856 * as simple as possible for now. Also, intentionally, if the target
2857 * range contains one or more prealloc extents together with regular
2858 * extents and holes, we drop all the existing extents and allocate a
2859 * new prealloc extent, so that we get a larger contiguous disk extent.
2861 if (em->start <= alloc_start &&
2862 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
2863 const u64 em_end = em->start + em->len;
2865 if (em_end >= offset + len) {
2867 * The whole range is already a prealloc extent,
2868 * do nothing except updating the inode's i_size if
2871 free_extent_map(em);
2872 ret = btrfs_fallocate_update_isize(inode, offset + len,
2877 * Part of the range is already a prealloc extent, so operate
2878 * only on the remaining part of the range.
2880 alloc_start = em_end;
2881 ASSERT(IS_ALIGNED(alloc_start, sectorsize));
2882 len = offset + len - alloc_start;
2883 offset = alloc_start;
2884 alloc_hint = em->block_start + em->len;
2886 free_extent_map(em);
2888 if (BTRFS_BYTES_TO_BLKS(fs_info, offset) ==
2889 BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)) {
2890 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0,
2891 alloc_start, sectorsize, 0);
2897 if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags)) {
2898 free_extent_map(em);
2899 ret = btrfs_fallocate_update_isize(inode, offset + len,
2903 if (len < sectorsize && em->block_start != EXTENT_MAP_HOLE) {
2904 free_extent_map(em);
2905 ret = btrfs_truncate_block(inode, offset, len, 0);
2907 ret = btrfs_fallocate_update_isize(inode,
2912 free_extent_map(em);
2913 alloc_start = round_down(offset, sectorsize);
2914 alloc_end = alloc_start + sectorsize;
2918 alloc_start = round_up(offset, sectorsize);
2919 alloc_end = round_down(offset + len, sectorsize);
2922 * For unaligned ranges, check the pages at the boundaries, they might
2923 * map to an extent, in which case we need to partially zero them, or
2924 * they might map to a hole, in which case we need our allocation range
2927 if (!IS_ALIGNED(offset, sectorsize)) {
2928 ret = btrfs_zero_range_check_range_boundary(inode, offset);
2931 if (ret == RANGE_BOUNDARY_HOLE) {
2932 alloc_start = round_down(offset, sectorsize);
2934 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
2935 ret = btrfs_truncate_block(inode, offset, 0, 0);
2943 if (!IS_ALIGNED(offset + len, sectorsize)) {
2944 ret = btrfs_zero_range_check_range_boundary(inode,
2948 if (ret == RANGE_BOUNDARY_HOLE) {
2949 alloc_end = round_up(offset + len, sectorsize);
2951 } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) {
2952 ret = btrfs_truncate_block(inode, offset + len, 0, 1);
2961 if (alloc_start < alloc_end) {
2962 struct extent_state *cached_state = NULL;
2963 const u64 lockstart = alloc_start;
2964 const u64 lockend = alloc_end - 1;
2966 bytes_to_reserve = alloc_end - alloc_start;
2967 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
2971 space_reserved = true;
2972 ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
2973 alloc_start, bytes_to_reserve);
2976 ret = btrfs_punch_hole_lock_range(inode, lockstart, lockend,
2980 ret = btrfs_prealloc_file_range(inode, mode, alloc_start,
2981 alloc_end - alloc_start,
2983 offset + len, &alloc_hint);
2984 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart,
2985 lockend, &cached_state);
2986 /* btrfs_prealloc_file_range releases reserved space on error */
2988 space_reserved = false;
2992 ret = btrfs_fallocate_update_isize(inode, offset + len, mode);
2994 if (ret && space_reserved)
2995 btrfs_free_reserved_data_space(inode, data_reserved,
2996 alloc_start, bytes_to_reserve);
2997 extent_changeset_free(data_reserved);
3002 static long btrfs_fallocate(struct file *file, int mode,
3003 loff_t offset, loff_t len)
3005 struct inode *inode = file_inode(file);
3006 struct extent_state *cached_state = NULL;
3007 struct extent_changeset *data_reserved = NULL;
3008 struct falloc_range *range;
3009 struct falloc_range *tmp;
3010 struct list_head reserve_list;
3018 struct extent_map *em;
3019 int blocksize = btrfs_inode_sectorsize(inode);
3022 alloc_start = round_down(offset, blocksize);
3023 alloc_end = round_up(offset + len, blocksize);
3024 cur_offset = alloc_start;
3026 /* Make sure we aren't being give some crap mode */
3027 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
3028 FALLOC_FL_ZERO_RANGE))
3031 if (mode & FALLOC_FL_PUNCH_HOLE)
3032 return btrfs_punch_hole(inode, offset, len);
3035 * Only trigger disk allocation, don't trigger qgroup reserve
3037 * For qgroup space, it will be checked later.
3039 if (!(mode & FALLOC_FL_ZERO_RANGE)) {
3040 ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode),
3041 alloc_end - alloc_start);
3048 if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) {
3049 ret = inode_newsize_ok(inode, offset + len);
3055 * TODO: Move these two operations after we have checked
3056 * accurate reserved space, or fallocate can still fail but
3057 * with page truncated or size expanded.
3059 * But that's a minor problem and won't do much harm BTW.
3061 if (alloc_start > inode->i_size) {
3062 ret = btrfs_cont_expand(inode, i_size_read(inode),
3066 } else if (offset + len > inode->i_size) {
3068 * If we are fallocating from the end of the file onward we
3069 * need to zero out the end of the block if i_size lands in the
3070 * middle of a block.
3072 ret = btrfs_truncate_block(inode, inode->i_size, 0, 0);
3078 * wait for ordered IO before we have any locks. We'll loop again
3079 * below with the locks held.
3081 ret = btrfs_wait_ordered_range(inode, alloc_start,
3082 alloc_end - alloc_start);
3086 if (mode & FALLOC_FL_ZERO_RANGE) {
3087 ret = btrfs_zero_range(inode, offset, len, mode);
3088 inode_unlock(inode);
3092 locked_end = alloc_end - 1;
3094 struct btrfs_ordered_extent *ordered;
3096 /* the extent lock is ordered inside the running
3099 lock_extent_bits(&BTRFS_I(inode)->io_tree, alloc_start,
3100 locked_end, &cached_state);
3101 ordered = btrfs_lookup_first_ordered_extent(inode, locked_end);
3104 ordered->file_offset + ordered->len > alloc_start &&
3105 ordered->file_offset < alloc_end) {
3106 btrfs_put_ordered_extent(ordered);
3107 unlock_extent_cached(&BTRFS_I(inode)->io_tree,
3108 alloc_start, locked_end,
3111 * we can't wait on the range with the transaction
3112 * running or with the extent lock held
3114 ret = btrfs_wait_ordered_range(inode, alloc_start,
3115 alloc_end - alloc_start);
3120 btrfs_put_ordered_extent(ordered);
3125 /* First, check if we exceed the qgroup limit */
3126 INIT_LIST_HEAD(&reserve_list);
3127 while (cur_offset < alloc_end) {
3128 em = btrfs_get_extent(BTRFS_I(inode), NULL, 0, cur_offset,
3129 alloc_end - cur_offset, 0);
3134 last_byte = min(extent_map_end(em), alloc_end);
3135 actual_end = min_t(u64, extent_map_end(em), offset + len);
3136 last_byte = ALIGN(last_byte, blocksize);
3137 if (em->block_start == EXTENT_MAP_HOLE ||
3138 (cur_offset >= inode->i_size &&
3139 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags))) {
3140 ret = add_falloc_range(&reserve_list, cur_offset,
3141 last_byte - cur_offset);
3143 free_extent_map(em);
3146 ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
3147 cur_offset, last_byte - cur_offset);
3149 cur_offset = last_byte;
3150 free_extent_map(em);
3155 * Do not need to reserve unwritten extent for this
3156 * range, free reserved data space first, otherwise
3157 * it'll result in false ENOSPC error.
3159 btrfs_free_reserved_data_space(inode, data_reserved,
3160 cur_offset, last_byte - cur_offset);
3162 free_extent_map(em);
3163 cur_offset = last_byte;
3167 * If ret is still 0, means we're OK to fallocate.
3168 * Or just cleanup the list and exit.
3170 list_for_each_entry_safe(range, tmp, &reserve_list, list) {
3172 ret = btrfs_prealloc_file_range(inode, mode,
3174 range->len, i_blocksize(inode),
3175 offset + len, &alloc_hint);
3177 btrfs_free_reserved_data_space(inode,
3178 data_reserved, range->start,
3180 list_del(&range->list);
3187 * We didn't need to allocate any more space, but we still extended the
3188 * size of the file so we need to update i_size and the inode item.
3190 ret = btrfs_fallocate_update_isize(inode, actual_end, mode);
3192 unlock_extent_cached(&BTRFS_I(inode)->io_tree, alloc_start, locked_end,
3195 inode_unlock(inode);
3196 /* Let go of our reservation. */
3197 if (ret != 0 && !(mode & FALLOC_FL_ZERO_RANGE))
3198 btrfs_free_reserved_data_space(inode, data_reserved,
3199 cur_offset, alloc_end - cur_offset);
3200 extent_changeset_free(data_reserved);
3204 static int find_desired_extent(struct inode *inode, loff_t *offset, int whence)
3206 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3207 struct extent_map *em = NULL;
3208 struct extent_state *cached_state = NULL;
3215 if (inode->i_size == 0)
3219 * *offset can be negative, in this case we start finding DATA/HOLE from
3220 * the very start of the file.
3222 start = max_t(loff_t, 0, *offset);
3224 lockstart = round_down(start, fs_info->sectorsize);
3225 lockend = round_up(i_size_read(inode),
3226 fs_info->sectorsize);
3227 if (lockend <= lockstart)
3228 lockend = lockstart + fs_info->sectorsize;
3230 len = lockend - lockstart + 1;
3232 lock_extent_bits(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3235 while (start < inode->i_size) {
3236 em = btrfs_get_extent_fiemap(BTRFS_I(inode), start, len);
3243 if (whence == SEEK_HOLE &&
3244 (em->block_start == EXTENT_MAP_HOLE ||
3245 test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3247 else if (whence == SEEK_DATA &&
3248 (em->block_start != EXTENT_MAP_HOLE &&
3249 !test_bit(EXTENT_FLAG_PREALLOC, &em->flags)))
3252 start = em->start + em->len;
3253 free_extent_map(em);
3257 free_extent_map(em);
3259 if (whence == SEEK_DATA && start >= inode->i_size)
3262 *offset = min_t(loff_t, start, inode->i_size);
3264 unlock_extent_cached(&BTRFS_I(inode)->io_tree, lockstart, lockend,
3269 static loff_t btrfs_file_llseek(struct file *file, loff_t offset, int whence)
3271 struct inode *inode = file->f_mapping->host;
3278 offset = generic_file_llseek(file, offset, whence);
3282 if (offset >= i_size_read(inode)) {
3283 inode_unlock(inode);
3287 ret = find_desired_extent(inode, &offset, whence);
3289 inode_unlock(inode);
3294 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
3296 inode_unlock(inode);
3300 static int btrfs_file_open(struct inode *inode, struct file *filp)
3302 filp->f_mode |= FMODE_NOWAIT;
3303 return generic_file_open(inode, filp);
3306 const struct file_operations btrfs_file_operations = {
3307 .llseek = btrfs_file_llseek,
3308 .read_iter = generic_file_read_iter,
3309 .splice_read = generic_file_splice_read,
3310 .write_iter = btrfs_file_write_iter,
3311 .mmap = btrfs_file_mmap,
3312 .open = btrfs_file_open,
3313 .release = btrfs_release_file,
3314 .fsync = btrfs_sync_file,
3315 .fallocate = btrfs_fallocate,
3316 .unlocked_ioctl = btrfs_ioctl,
3317 #ifdef CONFIG_COMPAT
3318 .compat_ioctl = btrfs_compat_ioctl,
3320 .remap_file_range = btrfs_remap_file_range,
3323 void __cold btrfs_auto_defrag_exit(void)
3325 kmem_cache_destroy(btrfs_inode_defrag_cachep);
3328 int __init btrfs_auto_defrag_init(void)
3330 btrfs_inode_defrag_cachep = kmem_cache_create("btrfs_inode_defrag",
3331 sizeof(struct inode_defrag), 0,
3334 if (!btrfs_inode_defrag_cachep)
3340 int btrfs_fdatawrite_range(struct inode *inode, loff_t start, loff_t end)
3345 * So with compression we will find and lock a dirty page and clear the
3346 * first one as dirty, setup an async extent, and immediately return
3347 * with the entire range locked but with nobody actually marked with
3348 * writeback. So we can't just filemap_write_and_wait_range() and
3349 * expect it to work since it will just kick off a thread to do the
3350 * actual work. So we need to call filemap_fdatawrite_range _again_
3351 * since it will wait on the page lock, which won't be unlocked until
3352 * after the pages have been marked as writeback and so we're good to go
3353 * from there. We have to do this otherwise we'll miss the ordered
3354 * extents and that results in badness. Please Josef, do not think you
3355 * know better and pull this out at some point in the future, it is
3356 * right and you are wrong.
3358 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);
3359 if (!ret && test_bit(BTRFS_INODE_HAS_ASYNC_EXTENT,
3360 &BTRFS_I(inode)->runtime_flags))
3361 ret = filemap_fdatawrite_range(inode->i_mapping, start, end);