2 * Copyright (C) 2009 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.
19 #include <linux/sched.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
27 #include "transaction.h"
30 #include "btrfs_inode.h"
31 #include "async-thread.h"
32 #include "free-space-cache.h"
33 #include "inode-map.h"
36 * backref_node, mapping_node and tree_block start with this
39 struct rb_node rb_node
;
44 * present a tree block in the backref cache
47 struct rb_node rb_node
;
51 /* objectid of tree block owner, can be not uptodate */
53 /* link to pending, changed or detached list */
54 struct list_head list
;
55 /* list of upper level blocks reference this block */
56 struct list_head upper
;
57 /* list of child blocks in the cache */
58 struct list_head lower
;
59 /* NULL if this node is not tree root */
60 struct btrfs_root
*root
;
61 /* extent buffer got by COW the block */
62 struct extent_buffer
*eb
;
63 /* level of tree block */
65 /* is the block in non-reference counted tree */
66 unsigned int cowonly
:1;
67 /* 1 if no child node in the cache */
68 unsigned int lowest
:1;
69 /* is the extent buffer locked */
70 unsigned int locked
:1;
71 /* has the block been processed */
72 unsigned int processed
:1;
73 /* have backrefs of this block been checked */
74 unsigned int checked
:1;
76 * 1 if corresponding block has been cowed but some upper
77 * level block pointers may not point to the new location
79 unsigned int pending
:1;
81 * 1 if the backref node isn't connected to any other
84 unsigned int detached
:1;
88 * present a block pointer in the backref cache
91 struct list_head list
[2];
92 struct backref_node
*node
[2];
98 struct backref_cache
{
99 /* red black tree of all backref nodes in the cache */
100 struct rb_root rb_root
;
101 /* for passing backref nodes to btrfs_reloc_cow_block */
102 struct backref_node
*path
[BTRFS_MAX_LEVEL
];
104 * list of blocks that have been cowed but some block
105 * pointers in upper level blocks may not reflect the
108 struct list_head pending
[BTRFS_MAX_LEVEL
];
109 /* list of backref nodes with no child node */
110 struct list_head leaves
;
111 /* list of blocks that have been cowed in current transaction */
112 struct list_head changed
;
113 /* list of detached backref node. */
114 struct list_head detached
;
123 * map address of tree root to tree
125 struct mapping_node
{
126 struct rb_node rb_node
;
131 struct mapping_tree
{
132 struct rb_root rb_root
;
137 * present a tree block to process
140 struct rb_node rb_node
;
142 struct btrfs_key key
;
143 unsigned int level
:8;
144 unsigned int key_ready
:1;
147 #define MAX_EXTENTS 128
149 struct file_extent_cluster
{
152 u64 boundary
[MAX_EXTENTS
];
156 struct reloc_control
{
157 /* block group to relocate */
158 struct btrfs_block_group_cache
*block_group
;
160 struct btrfs_root
*extent_root
;
161 /* inode for moving data */
162 struct inode
*data_inode
;
164 struct btrfs_block_rsv
*block_rsv
;
166 struct backref_cache backref_cache
;
168 struct file_extent_cluster cluster
;
169 /* tree blocks have been processed */
170 struct extent_io_tree processed_blocks
;
171 /* map start of tree root to corresponding reloc tree */
172 struct mapping_tree reloc_root_tree
;
173 /* list of reloc trees */
174 struct list_head reloc_roots
;
175 /* size of metadata reservation for merging reloc trees */
176 u64 merging_rsv_size
;
177 /* size of relocated tree nodes */
183 unsigned int stage
:8;
184 unsigned int create_reloc_tree
:1;
185 unsigned int merge_reloc_tree
:1;
186 unsigned int found_file_extent
:1;
187 unsigned int commit_transaction
:1;
190 /* stages of data relocation */
191 #define MOVE_DATA_EXTENTS 0
192 #define UPDATE_DATA_PTRS 1
194 static void remove_backref_node(struct backref_cache
*cache
,
195 struct backref_node
*node
);
196 static void __mark_block_processed(struct reloc_control
*rc
,
197 struct backref_node
*node
);
199 static void mapping_tree_init(struct mapping_tree
*tree
)
201 tree
->rb_root
= RB_ROOT
;
202 spin_lock_init(&tree
->lock
);
205 static void backref_cache_init(struct backref_cache
*cache
)
208 cache
->rb_root
= RB_ROOT
;
209 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++)
210 INIT_LIST_HEAD(&cache
->pending
[i
]);
211 INIT_LIST_HEAD(&cache
->changed
);
212 INIT_LIST_HEAD(&cache
->detached
);
213 INIT_LIST_HEAD(&cache
->leaves
);
216 static void backref_cache_cleanup(struct backref_cache
*cache
)
218 struct backref_node
*node
;
221 while (!list_empty(&cache
->detached
)) {
222 node
= list_entry(cache
->detached
.next
,
223 struct backref_node
, list
);
224 remove_backref_node(cache
, node
);
227 while (!list_empty(&cache
->leaves
)) {
228 node
= list_entry(cache
->leaves
.next
,
229 struct backref_node
, lower
);
230 remove_backref_node(cache
, node
);
233 cache
->last_trans
= 0;
235 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++)
236 BUG_ON(!list_empty(&cache
->pending
[i
]));
237 BUG_ON(!list_empty(&cache
->changed
));
238 BUG_ON(!list_empty(&cache
->detached
));
239 BUG_ON(!RB_EMPTY_ROOT(&cache
->rb_root
));
240 BUG_ON(cache
->nr_nodes
);
241 BUG_ON(cache
->nr_edges
);
244 static struct backref_node
*alloc_backref_node(struct backref_cache
*cache
)
246 struct backref_node
*node
;
248 node
= kzalloc(sizeof(*node
), GFP_NOFS
);
250 INIT_LIST_HEAD(&node
->list
);
251 INIT_LIST_HEAD(&node
->upper
);
252 INIT_LIST_HEAD(&node
->lower
);
253 RB_CLEAR_NODE(&node
->rb_node
);
259 static void free_backref_node(struct backref_cache
*cache
,
260 struct backref_node
*node
)
268 static struct backref_edge
*alloc_backref_edge(struct backref_cache
*cache
)
270 struct backref_edge
*edge
;
272 edge
= kzalloc(sizeof(*edge
), GFP_NOFS
);
278 static void free_backref_edge(struct backref_cache
*cache
,
279 struct backref_edge
*edge
)
287 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 bytenr
,
288 struct rb_node
*node
)
290 struct rb_node
**p
= &root
->rb_node
;
291 struct rb_node
*parent
= NULL
;
292 struct tree_entry
*entry
;
296 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
298 if (bytenr
< entry
->bytenr
)
300 else if (bytenr
> entry
->bytenr
)
306 rb_link_node(node
, parent
, p
);
307 rb_insert_color(node
, root
);
311 static struct rb_node
*tree_search(struct rb_root
*root
, u64 bytenr
)
313 struct rb_node
*n
= root
->rb_node
;
314 struct tree_entry
*entry
;
317 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
319 if (bytenr
< entry
->bytenr
)
321 else if (bytenr
> entry
->bytenr
)
329 void backref_tree_panic(struct rb_node
*rb_node
, int errno
,
333 struct btrfs_fs_info
*fs_info
= NULL
;
334 struct backref_node
*bnode
= rb_entry(rb_node
, struct backref_node
,
337 fs_info
= bnode
->root
->fs_info
;
338 btrfs_panic(fs_info
, errno
, "Inconsistency in backref cache "
339 "found at offset %llu\n", (unsigned long long)bytenr
);
343 * walk up backref nodes until reach node presents tree root
345 static struct backref_node
*walk_up_backref(struct backref_node
*node
,
346 struct backref_edge
*edges
[],
349 struct backref_edge
*edge
;
352 while (!list_empty(&node
->upper
)) {
353 edge
= list_entry(node
->upper
.next
,
354 struct backref_edge
, list
[LOWER
]);
356 node
= edge
->node
[UPPER
];
358 BUG_ON(node
->detached
);
364 * walk down backref nodes to find start of next reference path
366 static struct backref_node
*walk_down_backref(struct backref_edge
*edges
[],
369 struct backref_edge
*edge
;
370 struct backref_node
*lower
;
374 edge
= edges
[idx
- 1];
375 lower
= edge
->node
[LOWER
];
376 if (list_is_last(&edge
->list
[LOWER
], &lower
->upper
)) {
380 edge
= list_entry(edge
->list
[LOWER
].next
,
381 struct backref_edge
, list
[LOWER
]);
382 edges
[idx
- 1] = edge
;
384 return edge
->node
[UPPER
];
390 static void unlock_node_buffer(struct backref_node
*node
)
393 btrfs_tree_unlock(node
->eb
);
398 static void drop_node_buffer(struct backref_node
*node
)
401 unlock_node_buffer(node
);
402 free_extent_buffer(node
->eb
);
407 static void drop_backref_node(struct backref_cache
*tree
,
408 struct backref_node
*node
)
410 BUG_ON(!list_empty(&node
->upper
));
412 drop_node_buffer(node
);
413 list_del(&node
->list
);
414 list_del(&node
->lower
);
415 if (!RB_EMPTY_NODE(&node
->rb_node
))
416 rb_erase(&node
->rb_node
, &tree
->rb_root
);
417 free_backref_node(tree
, node
);
421 * remove a backref node from the backref cache
423 static void remove_backref_node(struct backref_cache
*cache
,
424 struct backref_node
*node
)
426 struct backref_node
*upper
;
427 struct backref_edge
*edge
;
432 BUG_ON(!node
->lowest
&& !node
->detached
);
433 while (!list_empty(&node
->upper
)) {
434 edge
= list_entry(node
->upper
.next
, struct backref_edge
,
436 upper
= edge
->node
[UPPER
];
437 list_del(&edge
->list
[LOWER
]);
438 list_del(&edge
->list
[UPPER
]);
439 free_backref_edge(cache
, edge
);
441 if (RB_EMPTY_NODE(&upper
->rb_node
)) {
442 BUG_ON(!list_empty(&node
->upper
));
443 drop_backref_node(cache
, node
);
449 * add the node to leaf node list if no other
450 * child block cached.
452 if (list_empty(&upper
->lower
)) {
453 list_add_tail(&upper
->lower
, &cache
->leaves
);
458 drop_backref_node(cache
, node
);
461 static void update_backref_node(struct backref_cache
*cache
,
462 struct backref_node
*node
, u64 bytenr
)
464 struct rb_node
*rb_node
;
465 rb_erase(&node
->rb_node
, &cache
->rb_root
);
466 node
->bytenr
= bytenr
;
467 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
, &node
->rb_node
);
469 backref_tree_panic(rb_node
, -EEXIST
, bytenr
);
473 * update backref cache after a transaction commit
475 static int update_backref_cache(struct btrfs_trans_handle
*trans
,
476 struct backref_cache
*cache
)
478 struct backref_node
*node
;
481 if (cache
->last_trans
== 0) {
482 cache
->last_trans
= trans
->transid
;
486 if (cache
->last_trans
== trans
->transid
)
490 * detached nodes are used to avoid unnecessary backref
491 * lookup. transaction commit changes the extent tree.
492 * so the detached nodes are no longer useful.
494 while (!list_empty(&cache
->detached
)) {
495 node
= list_entry(cache
->detached
.next
,
496 struct backref_node
, list
);
497 remove_backref_node(cache
, node
);
500 while (!list_empty(&cache
->changed
)) {
501 node
= list_entry(cache
->changed
.next
,
502 struct backref_node
, list
);
503 list_del_init(&node
->list
);
504 BUG_ON(node
->pending
);
505 update_backref_node(cache
, node
, node
->new_bytenr
);
509 * some nodes can be left in the pending list if there were
510 * errors during processing the pending nodes.
512 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
513 list_for_each_entry(node
, &cache
->pending
[level
], list
) {
514 BUG_ON(!node
->pending
);
515 if (node
->bytenr
== node
->new_bytenr
)
517 update_backref_node(cache
, node
, node
->new_bytenr
);
521 cache
->last_trans
= 0;
526 static int should_ignore_root(struct btrfs_root
*root
)
528 struct btrfs_root
*reloc_root
;
533 reloc_root
= root
->reloc_root
;
537 if (btrfs_root_last_snapshot(&reloc_root
->root_item
) ==
538 root
->fs_info
->running_transaction
->transid
- 1)
541 * if there is reloc tree and it was created in previous
542 * transaction backref lookup can find the reloc tree,
543 * so backref node for the fs tree root is useless for
549 * find reloc tree by address of tree root
551 static struct btrfs_root
*find_reloc_root(struct reloc_control
*rc
,
554 struct rb_node
*rb_node
;
555 struct mapping_node
*node
;
556 struct btrfs_root
*root
= NULL
;
558 spin_lock(&rc
->reloc_root_tree
.lock
);
559 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
, bytenr
);
561 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
562 root
= (struct btrfs_root
*)node
->data
;
564 spin_unlock(&rc
->reloc_root_tree
.lock
);
568 static int is_cowonly_root(u64 root_objectid
)
570 if (root_objectid
== BTRFS_ROOT_TREE_OBJECTID
||
571 root_objectid
== BTRFS_EXTENT_TREE_OBJECTID
||
572 root_objectid
== BTRFS_CHUNK_TREE_OBJECTID
||
573 root_objectid
== BTRFS_DEV_TREE_OBJECTID
||
574 root_objectid
== BTRFS_TREE_LOG_OBJECTID
||
575 root_objectid
== BTRFS_CSUM_TREE_OBJECTID
)
580 static struct btrfs_root
*read_fs_root(struct btrfs_fs_info
*fs_info
,
583 struct btrfs_key key
;
585 key
.objectid
= root_objectid
;
586 key
.type
= BTRFS_ROOT_ITEM_KEY
;
587 if (is_cowonly_root(root_objectid
))
590 key
.offset
= (u64
)-1;
592 return btrfs_read_fs_root_no_name(fs_info
, &key
);
595 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
596 static noinline_for_stack
597 struct btrfs_root
*find_tree_root(struct reloc_control
*rc
,
598 struct extent_buffer
*leaf
,
599 struct btrfs_extent_ref_v0
*ref0
)
601 struct btrfs_root
*root
;
602 u64 root_objectid
= btrfs_ref_root_v0(leaf
, ref0
);
603 u64 generation
= btrfs_ref_generation_v0(leaf
, ref0
);
605 BUG_ON(root_objectid
== BTRFS_TREE_RELOC_OBJECTID
);
607 root
= read_fs_root(rc
->extent_root
->fs_info
, root_objectid
);
608 BUG_ON(IS_ERR(root
));
610 if (root
->ref_cows
&&
611 generation
!= btrfs_root_generation(&root
->root_item
))
618 static noinline_for_stack
619 int find_inline_backref(struct extent_buffer
*leaf
, int slot
,
620 unsigned long *ptr
, unsigned long *end
)
622 struct btrfs_extent_item
*ei
;
623 struct btrfs_tree_block_info
*bi
;
626 item_size
= btrfs_item_size_nr(leaf
, slot
);
627 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
628 if (item_size
< sizeof(*ei
)) {
629 WARN_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
633 ei
= btrfs_item_ptr(leaf
, slot
, struct btrfs_extent_item
);
634 WARN_ON(!(btrfs_extent_flags(leaf
, ei
) &
635 BTRFS_EXTENT_FLAG_TREE_BLOCK
));
637 if (item_size
<= sizeof(*ei
) + sizeof(*bi
)) {
638 WARN_ON(item_size
< sizeof(*ei
) + sizeof(*bi
));
642 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
643 *ptr
= (unsigned long)(bi
+ 1);
644 *end
= (unsigned long)ei
+ item_size
;
649 * build backref tree for a given tree block. root of the backref tree
650 * corresponds the tree block, leaves of the backref tree correspond
651 * roots of b-trees that reference the tree block.
653 * the basic idea of this function is check backrefs of a given block
654 * to find upper level blocks that refernece the block, and then check
655 * bakcrefs of these upper level blocks recursively. the recursion stop
656 * when tree root is reached or backrefs for the block is cached.
658 * NOTE: if we find backrefs for a block are cached, we know backrefs
659 * for all upper level blocks that directly/indirectly reference the
660 * block are also cached.
662 static noinline_for_stack
663 struct backref_node
*build_backref_tree(struct reloc_control
*rc
,
664 struct btrfs_key
*node_key
,
665 int level
, u64 bytenr
)
667 struct backref_cache
*cache
= &rc
->backref_cache
;
668 struct btrfs_path
*path1
;
669 struct btrfs_path
*path2
;
670 struct extent_buffer
*eb
;
671 struct btrfs_root
*root
;
672 struct backref_node
*cur
;
673 struct backref_node
*upper
;
674 struct backref_node
*lower
;
675 struct backref_node
*node
= NULL
;
676 struct backref_node
*exist
= NULL
;
677 struct backref_edge
*edge
;
678 struct rb_node
*rb_node
;
679 struct btrfs_key key
;
688 path1
= btrfs_alloc_path();
689 path2
= btrfs_alloc_path();
690 if (!path1
|| !path2
) {
697 node
= alloc_backref_node(cache
);
703 node
->bytenr
= bytenr
;
710 key
.objectid
= cur
->bytenr
;
711 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
712 key
.offset
= (u64
)-1;
714 path1
->search_commit_root
= 1;
715 path1
->skip_locking
= 1;
716 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path1
,
722 BUG_ON(!ret
|| !path1
->slots
[0]);
726 WARN_ON(cur
->checked
);
727 if (!list_empty(&cur
->upper
)) {
729 * the backref was added previously when processing
730 * backref of type BTRFS_TREE_BLOCK_REF_KEY
732 BUG_ON(!list_is_singular(&cur
->upper
));
733 edge
= list_entry(cur
->upper
.next
, struct backref_edge
,
735 BUG_ON(!list_empty(&edge
->list
[UPPER
]));
736 exist
= edge
->node
[UPPER
];
738 * add the upper level block to pending list if we need
742 list_add_tail(&edge
->list
[UPPER
], &list
);
749 eb
= path1
->nodes
[0];
752 if (path1
->slots
[0] >= btrfs_header_nritems(eb
)) {
753 ret
= btrfs_next_leaf(rc
->extent_root
, path1
);
760 eb
= path1
->nodes
[0];
763 btrfs_item_key_to_cpu(eb
, &key
, path1
->slots
[0]);
764 if (key
.objectid
!= cur
->bytenr
) {
769 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
) {
770 ret
= find_inline_backref(eb
, path1
->slots
[0],
778 /* update key for inline back ref */
779 struct btrfs_extent_inline_ref
*iref
;
780 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
781 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
782 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
783 WARN_ON(key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
&&
784 key
.type
!= BTRFS_SHARED_BLOCK_REF_KEY
);
788 ((key
.type
== BTRFS_TREE_BLOCK_REF_KEY
&&
789 exist
->owner
== key
.offset
) ||
790 (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
&&
791 exist
->bytenr
== key
.offset
))) {
796 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
797 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
||
798 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
799 if (key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
800 struct btrfs_extent_ref_v0
*ref0
;
801 ref0
= btrfs_item_ptr(eb
, path1
->slots
[0],
802 struct btrfs_extent_ref_v0
);
803 if (key
.objectid
== key
.offset
) {
804 root
= find_tree_root(rc
, eb
, ref0
);
805 if (root
&& !should_ignore_root(root
))
808 list_add(&cur
->list
, &useless
);
811 if (is_cowonly_root(btrfs_ref_root_v0(eb
,
816 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
817 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
) {
819 if (key
.objectid
== key
.offset
) {
821 * only root blocks of reloc trees use
822 * backref of this type.
824 root
= find_reloc_root(rc
, cur
->bytenr
);
830 edge
= alloc_backref_edge(cache
);
835 rb_node
= tree_search(&cache
->rb_root
, key
.offset
);
837 upper
= alloc_backref_node(cache
);
839 free_backref_edge(cache
, edge
);
843 upper
->bytenr
= key
.offset
;
844 upper
->level
= cur
->level
+ 1;
846 * backrefs for the upper level block isn't
847 * cached, add the block to pending list
849 list_add_tail(&edge
->list
[UPPER
], &list
);
851 upper
= rb_entry(rb_node
, struct backref_node
,
853 BUG_ON(!upper
->checked
);
854 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
856 list_add_tail(&edge
->list
[LOWER
], &cur
->upper
);
857 edge
->node
[LOWER
] = cur
;
858 edge
->node
[UPPER
] = upper
;
861 } else if (key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
) {
865 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
866 root
= read_fs_root(rc
->extent_root
->fs_info
, key
.offset
);
875 if (btrfs_root_level(&root
->root_item
) == cur
->level
) {
877 BUG_ON(btrfs_root_bytenr(&root
->root_item
) !=
879 if (should_ignore_root(root
))
880 list_add(&cur
->list
, &useless
);
886 level
= cur
->level
+ 1;
889 * searching the tree to find upper level blocks
890 * reference the block.
892 path2
->search_commit_root
= 1;
893 path2
->skip_locking
= 1;
894 path2
->lowest_level
= level
;
895 ret
= btrfs_search_slot(NULL
, root
, node_key
, path2
, 0, 0);
896 path2
->lowest_level
= 0;
901 if (ret
> 0 && path2
->slots
[level
] > 0)
902 path2
->slots
[level
]--;
904 eb
= path2
->nodes
[level
];
905 WARN_ON(btrfs_node_blockptr(eb
, path2
->slots
[level
]) !=
909 for (; level
< BTRFS_MAX_LEVEL
; level
++) {
910 if (!path2
->nodes
[level
]) {
911 BUG_ON(btrfs_root_bytenr(&root
->root_item
) !=
913 if (should_ignore_root(root
))
914 list_add(&lower
->list
, &useless
);
920 edge
= alloc_backref_edge(cache
);
926 eb
= path2
->nodes
[level
];
927 rb_node
= tree_search(&cache
->rb_root
, eb
->start
);
929 upper
= alloc_backref_node(cache
);
931 free_backref_edge(cache
, edge
);
935 upper
->bytenr
= eb
->start
;
936 upper
->owner
= btrfs_header_owner(eb
);
937 upper
->level
= lower
->level
+ 1;
942 * if we know the block isn't shared
943 * we can void checking its backrefs.
945 if (btrfs_block_can_be_shared(root
, eb
))
951 * add the block to pending list if we
952 * need check its backrefs. only block
953 * at 'cur->level + 1' is added to the
954 * tail of pending list. this guarantees
955 * we check backrefs from lower level
956 * blocks to upper level blocks.
958 if (!upper
->checked
&&
959 level
== cur
->level
+ 1) {
960 list_add_tail(&edge
->list
[UPPER
],
963 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
965 upper
= rb_entry(rb_node
, struct backref_node
,
967 BUG_ON(!upper
->checked
);
968 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
970 upper
->owner
= btrfs_header_owner(eb
);
972 list_add_tail(&edge
->list
[LOWER
], &lower
->upper
);
973 edge
->node
[LOWER
] = lower
;
974 edge
->node
[UPPER
] = upper
;
981 btrfs_release_path(path2
);
984 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
994 btrfs_release_path(path1
);
999 /* the pending list isn't empty, take the first block to process */
1000 if (!list_empty(&list
)) {
1001 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1002 list_del_init(&edge
->list
[UPPER
]);
1003 cur
= edge
->node
[UPPER
];
1008 * everything goes well, connect backref nodes and insert backref nodes
1011 BUG_ON(!node
->checked
);
1012 cowonly
= node
->cowonly
;
1014 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
,
1017 backref_tree_panic(rb_node
, -EEXIST
, node
->bytenr
);
1018 list_add_tail(&node
->lower
, &cache
->leaves
);
1021 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
])
1022 list_add_tail(&edge
->list
[UPPER
], &list
);
1024 while (!list_empty(&list
)) {
1025 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1026 list_del_init(&edge
->list
[UPPER
]);
1027 upper
= edge
->node
[UPPER
];
1028 if (upper
->detached
) {
1029 list_del(&edge
->list
[LOWER
]);
1030 lower
= edge
->node
[LOWER
];
1031 free_backref_edge(cache
, edge
);
1032 if (list_empty(&lower
->upper
))
1033 list_add(&lower
->list
, &useless
);
1037 if (!RB_EMPTY_NODE(&upper
->rb_node
)) {
1038 if (upper
->lowest
) {
1039 list_del_init(&upper
->lower
);
1043 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1047 BUG_ON(!upper
->checked
);
1048 BUG_ON(cowonly
!= upper
->cowonly
);
1050 rb_node
= tree_insert(&cache
->rb_root
, upper
->bytenr
,
1053 backref_tree_panic(rb_node
, -EEXIST
,
1057 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1059 list_for_each_entry(edge
, &upper
->upper
, list
[LOWER
])
1060 list_add_tail(&edge
->list
[UPPER
], &list
);
1063 * process useless backref nodes. backref nodes for tree leaves
1064 * are deleted from the cache. backref nodes for upper level
1065 * tree blocks are left in the cache to avoid unnecessary backref
1068 while (!list_empty(&useless
)) {
1069 upper
= list_entry(useless
.next
, struct backref_node
, list
);
1070 list_del_init(&upper
->list
);
1071 BUG_ON(!list_empty(&upper
->upper
));
1074 if (upper
->lowest
) {
1075 list_del_init(&upper
->lower
);
1078 while (!list_empty(&upper
->lower
)) {
1079 edge
= list_entry(upper
->lower
.next
,
1080 struct backref_edge
, list
[UPPER
]);
1081 list_del(&edge
->list
[UPPER
]);
1082 list_del(&edge
->list
[LOWER
]);
1083 lower
= edge
->node
[LOWER
];
1084 free_backref_edge(cache
, edge
);
1086 if (list_empty(&lower
->upper
))
1087 list_add(&lower
->list
, &useless
);
1089 __mark_block_processed(rc
, upper
);
1090 if (upper
->level
> 0) {
1091 list_add(&upper
->list
, &cache
->detached
);
1092 upper
->detached
= 1;
1094 rb_erase(&upper
->rb_node
, &cache
->rb_root
);
1095 free_backref_node(cache
, upper
);
1099 btrfs_free_path(path1
);
1100 btrfs_free_path(path2
);
1102 while (!list_empty(&useless
)) {
1103 lower
= list_entry(useless
.next
,
1104 struct backref_node
, upper
);
1105 list_del_init(&lower
->upper
);
1108 INIT_LIST_HEAD(&list
);
1110 if (RB_EMPTY_NODE(&upper
->rb_node
)) {
1111 list_splice_tail(&upper
->upper
, &list
);
1112 free_backref_node(cache
, upper
);
1115 if (list_empty(&list
))
1118 edge
= list_entry(list
.next
, struct backref_edge
,
1120 list_del(&edge
->list
[LOWER
]);
1121 upper
= edge
->node
[UPPER
];
1122 free_backref_edge(cache
, edge
);
1124 return ERR_PTR(err
);
1126 BUG_ON(node
&& node
->detached
);
1131 * helper to add backref node for the newly created snapshot.
1132 * the backref node is created by cloning backref node that
1133 * corresponds to root of source tree
1135 static int clone_backref_node(struct btrfs_trans_handle
*trans
,
1136 struct reloc_control
*rc
,
1137 struct btrfs_root
*src
,
1138 struct btrfs_root
*dest
)
1140 struct btrfs_root
*reloc_root
= src
->reloc_root
;
1141 struct backref_cache
*cache
= &rc
->backref_cache
;
1142 struct backref_node
*node
= NULL
;
1143 struct backref_node
*new_node
;
1144 struct backref_edge
*edge
;
1145 struct backref_edge
*new_edge
;
1146 struct rb_node
*rb_node
;
1148 if (cache
->last_trans
> 0)
1149 update_backref_cache(trans
, cache
);
1151 rb_node
= tree_search(&cache
->rb_root
, src
->commit_root
->start
);
1153 node
= rb_entry(rb_node
, struct backref_node
, rb_node
);
1157 BUG_ON(node
->new_bytenr
!= reloc_root
->node
->start
);
1161 rb_node
= tree_search(&cache
->rb_root
,
1162 reloc_root
->commit_root
->start
);
1164 node
= rb_entry(rb_node
, struct backref_node
,
1166 BUG_ON(node
->detached
);
1173 new_node
= alloc_backref_node(cache
);
1177 new_node
->bytenr
= dest
->node
->start
;
1178 new_node
->level
= node
->level
;
1179 new_node
->lowest
= node
->lowest
;
1180 new_node
->checked
= 1;
1181 new_node
->root
= dest
;
1183 if (!node
->lowest
) {
1184 list_for_each_entry(edge
, &node
->lower
, list
[UPPER
]) {
1185 new_edge
= alloc_backref_edge(cache
);
1189 new_edge
->node
[UPPER
] = new_node
;
1190 new_edge
->node
[LOWER
] = edge
->node
[LOWER
];
1191 list_add_tail(&new_edge
->list
[UPPER
],
1195 list_add_tail(&new_node
->lower
, &cache
->leaves
);
1198 rb_node
= tree_insert(&cache
->rb_root
, new_node
->bytenr
,
1199 &new_node
->rb_node
);
1201 backref_tree_panic(rb_node
, -EEXIST
, new_node
->bytenr
);
1203 if (!new_node
->lowest
) {
1204 list_for_each_entry(new_edge
, &new_node
->lower
, list
[UPPER
]) {
1205 list_add_tail(&new_edge
->list
[LOWER
],
1206 &new_edge
->node
[LOWER
]->upper
);
1211 while (!list_empty(&new_node
->lower
)) {
1212 new_edge
= list_entry(new_node
->lower
.next
,
1213 struct backref_edge
, list
[UPPER
]);
1214 list_del(&new_edge
->list
[UPPER
]);
1215 free_backref_edge(cache
, new_edge
);
1217 free_backref_node(cache
, new_node
);
1222 * helper to add 'address of tree root -> reloc tree' mapping
1224 static int __must_check
__add_reloc_root(struct btrfs_root
*root
)
1226 struct rb_node
*rb_node
;
1227 struct mapping_node
*node
;
1228 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1230 node
= kmalloc(sizeof(*node
), GFP_NOFS
);
1234 node
->bytenr
= root
->node
->start
;
1237 spin_lock(&rc
->reloc_root_tree
.lock
);
1238 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1239 node
->bytenr
, &node
->rb_node
);
1240 spin_unlock(&rc
->reloc_root_tree
.lock
);
1242 btrfs_panic(root
->fs_info
, -EEXIST
, "Duplicate root found "
1243 "for start=%llu while inserting into relocation "
1244 "tree\n", node
->bytenr
);
1249 list_add_tail(&root
->root_list
, &rc
->reloc_roots
);
1254 * helper to update/delete the 'address of tree root -> reloc tree'
1257 static int __update_reloc_root(struct btrfs_root
*root
, int del
)
1259 struct rb_node
*rb_node
;
1260 struct mapping_node
*node
= NULL
;
1261 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1263 spin_lock(&rc
->reloc_root_tree
.lock
);
1264 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
,
1265 root
->commit_root
->start
);
1267 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
1268 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
1270 spin_unlock(&rc
->reloc_root_tree
.lock
);
1272 BUG_ON((struct btrfs_root
*)node
->data
!= root
);
1275 spin_lock(&rc
->reloc_root_tree
.lock
);
1276 node
->bytenr
= root
->node
->start
;
1277 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1278 node
->bytenr
, &node
->rb_node
);
1279 spin_unlock(&rc
->reloc_root_tree
.lock
);
1281 backref_tree_panic(rb_node
, -EEXIST
, node
->bytenr
);
1283 spin_lock(&root
->fs_info
->trans_lock
);
1284 list_del_init(&root
->root_list
);
1285 spin_unlock(&root
->fs_info
->trans_lock
);
1291 static struct btrfs_root
*create_reloc_root(struct btrfs_trans_handle
*trans
,
1292 struct btrfs_root
*root
, u64 objectid
)
1294 struct btrfs_root
*reloc_root
;
1295 struct extent_buffer
*eb
;
1296 struct btrfs_root_item
*root_item
;
1297 struct btrfs_key root_key
;
1300 root_item
= kmalloc(sizeof(*root_item
), GFP_NOFS
);
1303 root_key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
1304 root_key
.type
= BTRFS_ROOT_ITEM_KEY
;
1305 root_key
.offset
= objectid
;
1307 if (root
->root_key
.objectid
== objectid
) {
1308 /* called by btrfs_init_reloc_root */
1309 ret
= btrfs_copy_root(trans
, root
, root
->commit_root
, &eb
,
1310 BTRFS_TREE_RELOC_OBJECTID
);
1313 btrfs_set_root_last_snapshot(&root
->root_item
,
1314 trans
->transid
- 1);
1317 * called by btrfs_reloc_post_snapshot_hook.
1318 * the source tree is a reloc tree, all tree blocks
1319 * modified after it was created have RELOC flag
1320 * set in their headers. so it's OK to not update
1321 * the 'last_snapshot'.
1323 ret
= btrfs_copy_root(trans
, root
, root
->node
, &eb
,
1324 BTRFS_TREE_RELOC_OBJECTID
);
1328 memcpy(root_item
, &root
->root_item
, sizeof(*root_item
));
1329 btrfs_set_root_bytenr(root_item
, eb
->start
);
1330 btrfs_set_root_level(root_item
, btrfs_header_level(eb
));
1331 btrfs_set_root_generation(root_item
, trans
->transid
);
1333 if (root
->root_key
.objectid
== objectid
) {
1334 btrfs_set_root_refs(root_item
, 0);
1335 memset(&root_item
->drop_progress
, 0,
1336 sizeof(struct btrfs_disk_key
));
1337 root_item
->drop_level
= 0;
1340 btrfs_tree_unlock(eb
);
1341 free_extent_buffer(eb
);
1343 ret
= btrfs_insert_root(trans
, root
->fs_info
->tree_root
,
1344 &root_key
, root_item
);
1348 reloc_root
= btrfs_read_fs_root_no_radix(root
->fs_info
->tree_root
,
1350 BUG_ON(IS_ERR(reloc_root
));
1351 reloc_root
->last_trans
= trans
->transid
;
1356 * create reloc tree for a given fs tree. reloc tree is just a
1357 * snapshot of the fs tree with special root objectid.
1359 int btrfs_init_reloc_root(struct btrfs_trans_handle
*trans
,
1360 struct btrfs_root
*root
)
1362 struct btrfs_root
*reloc_root
;
1363 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1367 if (root
->reloc_root
) {
1368 reloc_root
= root
->reloc_root
;
1369 reloc_root
->last_trans
= trans
->transid
;
1373 if (!rc
|| !rc
->create_reloc_tree
||
1374 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1377 if (!trans
->block_rsv
) {
1378 trans
->block_rsv
= rc
->block_rsv
;
1381 reloc_root
= create_reloc_root(trans
, root
, root
->root_key
.objectid
);
1383 trans
->block_rsv
= NULL
;
1385 ret
= __add_reloc_root(reloc_root
);
1387 root
->reloc_root
= reloc_root
;
1392 * update root item of reloc tree
1394 int btrfs_update_reloc_root(struct btrfs_trans_handle
*trans
,
1395 struct btrfs_root
*root
)
1397 struct btrfs_root
*reloc_root
;
1398 struct btrfs_root_item
*root_item
;
1402 if (!root
->reloc_root
)
1405 reloc_root
= root
->reloc_root
;
1406 root_item
= &reloc_root
->root_item
;
1408 if (root
->fs_info
->reloc_ctl
->merge_reloc_tree
&&
1409 btrfs_root_refs(root_item
) == 0) {
1410 root
->reloc_root
= NULL
;
1414 __update_reloc_root(reloc_root
, del
);
1416 if (reloc_root
->commit_root
!= reloc_root
->node
) {
1417 btrfs_set_root_node(root_item
, reloc_root
->node
);
1418 free_extent_buffer(reloc_root
->commit_root
);
1419 reloc_root
->commit_root
= btrfs_root_node(reloc_root
);
1422 ret
= btrfs_update_root(trans
, root
->fs_info
->tree_root
,
1423 &reloc_root
->root_key
, root_item
);
1431 * helper to find first cached inode with inode number >= objectid
1434 static struct inode
*find_next_inode(struct btrfs_root
*root
, u64 objectid
)
1436 struct rb_node
*node
;
1437 struct rb_node
*prev
;
1438 struct btrfs_inode
*entry
;
1439 struct inode
*inode
;
1441 spin_lock(&root
->inode_lock
);
1443 node
= root
->inode_tree
.rb_node
;
1447 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1449 if (objectid
< btrfs_ino(&entry
->vfs_inode
))
1450 node
= node
->rb_left
;
1451 else if (objectid
> btrfs_ino(&entry
->vfs_inode
))
1452 node
= node
->rb_right
;
1458 entry
= rb_entry(prev
, struct btrfs_inode
, rb_node
);
1459 if (objectid
<= btrfs_ino(&entry
->vfs_inode
)) {
1463 prev
= rb_next(prev
);
1467 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1468 inode
= igrab(&entry
->vfs_inode
);
1470 spin_unlock(&root
->inode_lock
);
1474 objectid
= btrfs_ino(&entry
->vfs_inode
) + 1;
1475 if (cond_resched_lock(&root
->inode_lock
))
1478 node
= rb_next(node
);
1480 spin_unlock(&root
->inode_lock
);
1484 static int in_block_group(u64 bytenr
,
1485 struct btrfs_block_group_cache
*block_group
)
1487 if (bytenr
>= block_group
->key
.objectid
&&
1488 bytenr
< block_group
->key
.objectid
+ block_group
->key
.offset
)
1494 * get new location of data
1496 static int get_new_location(struct inode
*reloc_inode
, u64
*new_bytenr
,
1497 u64 bytenr
, u64 num_bytes
)
1499 struct btrfs_root
*root
= BTRFS_I(reloc_inode
)->root
;
1500 struct btrfs_path
*path
;
1501 struct btrfs_file_extent_item
*fi
;
1502 struct extent_buffer
*leaf
;
1505 path
= btrfs_alloc_path();
1509 bytenr
-= BTRFS_I(reloc_inode
)->index_cnt
;
1510 ret
= btrfs_lookup_file_extent(NULL
, root
, path
, btrfs_ino(reloc_inode
),
1519 leaf
= path
->nodes
[0];
1520 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
1521 struct btrfs_file_extent_item
);
1523 BUG_ON(btrfs_file_extent_offset(leaf
, fi
) ||
1524 btrfs_file_extent_compression(leaf
, fi
) ||
1525 btrfs_file_extent_encryption(leaf
, fi
) ||
1526 btrfs_file_extent_other_encoding(leaf
, fi
));
1528 if (num_bytes
!= btrfs_file_extent_disk_num_bytes(leaf
, fi
)) {
1533 *new_bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1536 btrfs_free_path(path
);
1541 * update file extent items in the tree leaf to point to
1542 * the new locations.
1544 static noinline_for_stack
1545 int replace_file_extents(struct btrfs_trans_handle
*trans
,
1546 struct reloc_control
*rc
,
1547 struct btrfs_root
*root
,
1548 struct extent_buffer
*leaf
)
1550 struct btrfs_key key
;
1551 struct btrfs_file_extent_item
*fi
;
1552 struct inode
*inode
= NULL
;
1564 if (rc
->stage
!= UPDATE_DATA_PTRS
)
1567 /* reloc trees always use full backref */
1568 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1569 parent
= leaf
->start
;
1573 nritems
= btrfs_header_nritems(leaf
);
1574 for (i
= 0; i
< nritems
; i
++) {
1576 btrfs_item_key_to_cpu(leaf
, &key
, i
);
1577 if (key
.type
!= BTRFS_EXTENT_DATA_KEY
)
1579 fi
= btrfs_item_ptr(leaf
, i
, struct btrfs_file_extent_item
);
1580 if (btrfs_file_extent_type(leaf
, fi
) ==
1581 BTRFS_FILE_EXTENT_INLINE
)
1583 bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1584 num_bytes
= btrfs_file_extent_disk_num_bytes(leaf
, fi
);
1587 if (!in_block_group(bytenr
, rc
->block_group
))
1591 * if we are modifying block in fs tree, wait for readpage
1592 * to complete and drop the extent cache
1594 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
) {
1596 inode
= find_next_inode(root
, key
.objectid
);
1598 } else if (inode
&& btrfs_ino(inode
) < key
.objectid
) {
1599 btrfs_add_delayed_iput(inode
);
1600 inode
= find_next_inode(root
, key
.objectid
);
1602 if (inode
&& btrfs_ino(inode
) == key
.objectid
) {
1604 btrfs_file_extent_num_bytes(leaf
, fi
);
1605 WARN_ON(!IS_ALIGNED(key
.offset
,
1607 WARN_ON(!IS_ALIGNED(end
, root
->sectorsize
));
1609 ret
= try_lock_extent(&BTRFS_I(inode
)->io_tree
,
1614 btrfs_drop_extent_cache(inode
, key
.offset
, end
,
1616 unlock_extent(&BTRFS_I(inode
)->io_tree
,
1621 ret
= get_new_location(rc
->data_inode
, &new_bytenr
,
1629 btrfs_set_file_extent_disk_bytenr(leaf
, fi
, new_bytenr
);
1632 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
1633 ret
= btrfs_inc_extent_ref(trans
, root
, new_bytenr
,
1635 btrfs_header_owner(leaf
),
1636 key
.objectid
, key
.offset
, 1);
1639 ret
= btrfs_free_extent(trans
, root
, bytenr
, num_bytes
,
1640 parent
, btrfs_header_owner(leaf
),
1641 key
.objectid
, key
.offset
, 1);
1645 btrfs_mark_buffer_dirty(leaf
);
1647 btrfs_add_delayed_iput(inode
);
1651 static noinline_for_stack
1652 int memcmp_node_keys(struct extent_buffer
*eb
, int slot
,
1653 struct btrfs_path
*path
, int level
)
1655 struct btrfs_disk_key key1
;
1656 struct btrfs_disk_key key2
;
1657 btrfs_node_key(eb
, &key1
, slot
);
1658 btrfs_node_key(path
->nodes
[level
], &key2
, path
->slots
[level
]);
1659 return memcmp(&key1
, &key2
, sizeof(key1
));
1663 * try to replace tree blocks in fs tree with the new blocks
1664 * in reloc tree. tree blocks haven't been modified since the
1665 * reloc tree was create can be replaced.
1667 * if a block was replaced, level of the block + 1 is returned.
1668 * if no block got replaced, 0 is returned. if there are other
1669 * errors, a negative error number is returned.
1671 static noinline_for_stack
1672 int replace_path(struct btrfs_trans_handle
*trans
,
1673 struct btrfs_root
*dest
, struct btrfs_root
*src
,
1674 struct btrfs_path
*path
, struct btrfs_key
*next_key
,
1675 int lowest_level
, int max_level
)
1677 struct extent_buffer
*eb
;
1678 struct extent_buffer
*parent
;
1679 struct btrfs_key key
;
1691 BUG_ON(src
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
);
1692 BUG_ON(dest
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
);
1694 last_snapshot
= btrfs_root_last_snapshot(&src
->root_item
);
1696 slot
= path
->slots
[lowest_level
];
1697 btrfs_node_key_to_cpu(path
->nodes
[lowest_level
], &key
, slot
);
1699 eb
= btrfs_lock_root_node(dest
);
1700 btrfs_set_lock_blocking(eb
);
1701 level
= btrfs_header_level(eb
);
1703 if (level
< lowest_level
) {
1704 btrfs_tree_unlock(eb
);
1705 free_extent_buffer(eb
);
1710 ret
= btrfs_cow_block(trans
, dest
, eb
, NULL
, 0, &eb
);
1713 btrfs_set_lock_blocking(eb
);
1716 next_key
->objectid
= (u64
)-1;
1717 next_key
->type
= (u8
)-1;
1718 next_key
->offset
= (u64
)-1;
1723 level
= btrfs_header_level(parent
);
1724 BUG_ON(level
< lowest_level
);
1726 ret
= btrfs_bin_search(parent
, &key
, level
, &slot
);
1727 if (ret
&& slot
> 0)
1730 if (next_key
&& slot
+ 1 < btrfs_header_nritems(parent
))
1731 btrfs_node_key_to_cpu(parent
, next_key
, slot
+ 1);
1733 old_bytenr
= btrfs_node_blockptr(parent
, slot
);
1734 blocksize
= btrfs_level_size(dest
, level
- 1);
1735 old_ptr_gen
= btrfs_node_ptr_generation(parent
, slot
);
1737 if (level
<= max_level
) {
1738 eb
= path
->nodes
[level
];
1739 new_bytenr
= btrfs_node_blockptr(eb
,
1740 path
->slots
[level
]);
1741 new_ptr_gen
= btrfs_node_ptr_generation(eb
,
1742 path
->slots
[level
]);
1748 if (new_bytenr
> 0 && new_bytenr
== old_bytenr
) {
1754 if (new_bytenr
== 0 || old_ptr_gen
> last_snapshot
||
1755 memcmp_node_keys(parent
, slot
, path
, level
)) {
1756 if (level
<= lowest_level
) {
1761 eb
= read_tree_block(dest
, old_bytenr
, blocksize
,
1764 btrfs_tree_lock(eb
);
1766 ret
= btrfs_cow_block(trans
, dest
, eb
, parent
,
1770 btrfs_set_lock_blocking(eb
);
1772 btrfs_tree_unlock(parent
);
1773 free_extent_buffer(parent
);
1780 btrfs_tree_unlock(parent
);
1781 free_extent_buffer(parent
);
1786 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
1787 path
->slots
[level
]);
1788 btrfs_release_path(path
);
1790 path
->lowest_level
= level
;
1791 ret
= btrfs_search_slot(trans
, src
, &key
, path
, 0, 1);
1792 path
->lowest_level
= 0;
1796 * swap blocks in fs tree and reloc tree.
1798 btrfs_set_node_blockptr(parent
, slot
, new_bytenr
);
1799 btrfs_set_node_ptr_generation(parent
, slot
, new_ptr_gen
);
1800 btrfs_mark_buffer_dirty(parent
);
1802 btrfs_set_node_blockptr(path
->nodes
[level
],
1803 path
->slots
[level
], old_bytenr
);
1804 btrfs_set_node_ptr_generation(path
->nodes
[level
],
1805 path
->slots
[level
], old_ptr_gen
);
1806 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
1808 ret
= btrfs_inc_extent_ref(trans
, src
, old_bytenr
, blocksize
,
1809 path
->nodes
[level
]->start
,
1810 src
->root_key
.objectid
, level
- 1, 0,
1813 ret
= btrfs_inc_extent_ref(trans
, dest
, new_bytenr
, blocksize
,
1814 0, dest
->root_key
.objectid
, level
- 1,
1818 ret
= btrfs_free_extent(trans
, src
, new_bytenr
, blocksize
,
1819 path
->nodes
[level
]->start
,
1820 src
->root_key
.objectid
, level
- 1, 0,
1824 ret
= btrfs_free_extent(trans
, dest
, old_bytenr
, blocksize
,
1825 0, dest
->root_key
.objectid
, level
- 1,
1829 btrfs_unlock_up_safe(path
, 0);
1834 btrfs_tree_unlock(parent
);
1835 free_extent_buffer(parent
);
1840 * helper to find next relocated block in reloc tree
1842 static noinline_for_stack
1843 int walk_up_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1846 struct extent_buffer
*eb
;
1851 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1853 for (i
= 0; i
< *level
; i
++) {
1854 free_extent_buffer(path
->nodes
[i
]);
1855 path
->nodes
[i
] = NULL
;
1858 for (i
= *level
; i
< BTRFS_MAX_LEVEL
&& path
->nodes
[i
]; i
++) {
1859 eb
= path
->nodes
[i
];
1860 nritems
= btrfs_header_nritems(eb
);
1861 while (path
->slots
[i
] + 1 < nritems
) {
1863 if (btrfs_node_ptr_generation(eb
, path
->slots
[i
]) <=
1870 free_extent_buffer(path
->nodes
[i
]);
1871 path
->nodes
[i
] = NULL
;
1877 * walk down reloc tree to find relocated block of lowest level
1879 static noinline_for_stack
1880 int walk_down_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1883 struct extent_buffer
*eb
= NULL
;
1891 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1893 for (i
= *level
; i
> 0; i
--) {
1894 eb
= path
->nodes
[i
];
1895 nritems
= btrfs_header_nritems(eb
);
1896 while (path
->slots
[i
] < nritems
) {
1897 ptr_gen
= btrfs_node_ptr_generation(eb
, path
->slots
[i
]);
1898 if (ptr_gen
> last_snapshot
)
1902 if (path
->slots
[i
] >= nritems
) {
1913 bytenr
= btrfs_node_blockptr(eb
, path
->slots
[i
]);
1914 blocksize
= btrfs_level_size(root
, i
- 1);
1915 eb
= read_tree_block(root
, bytenr
, blocksize
, ptr_gen
);
1916 BUG_ON(btrfs_header_level(eb
) != i
- 1);
1917 path
->nodes
[i
- 1] = eb
;
1918 path
->slots
[i
- 1] = 0;
1924 * invalidate extent cache for file extents whose key in range of
1925 * [min_key, max_key)
1927 static int invalidate_extent_cache(struct btrfs_root
*root
,
1928 struct btrfs_key
*min_key
,
1929 struct btrfs_key
*max_key
)
1931 struct inode
*inode
= NULL
;
1936 objectid
= min_key
->objectid
;
1941 if (objectid
> max_key
->objectid
)
1944 inode
= find_next_inode(root
, objectid
);
1947 ino
= btrfs_ino(inode
);
1949 if (ino
> max_key
->objectid
) {
1955 if (!S_ISREG(inode
->i_mode
))
1958 if (unlikely(min_key
->objectid
== ino
)) {
1959 if (min_key
->type
> BTRFS_EXTENT_DATA_KEY
)
1961 if (min_key
->type
< BTRFS_EXTENT_DATA_KEY
)
1964 start
= min_key
->offset
;
1965 WARN_ON(!IS_ALIGNED(start
, root
->sectorsize
));
1971 if (unlikely(max_key
->objectid
== ino
)) {
1972 if (max_key
->type
< BTRFS_EXTENT_DATA_KEY
)
1974 if (max_key
->type
> BTRFS_EXTENT_DATA_KEY
) {
1977 if (max_key
->offset
== 0)
1979 end
= max_key
->offset
;
1980 WARN_ON(!IS_ALIGNED(end
, root
->sectorsize
));
1987 /* the lock_extent waits for readpage to complete */
1988 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
1989 btrfs_drop_extent_cache(inode
, start
, end
, 1);
1990 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
1995 static int find_next_key(struct btrfs_path
*path
, int level
,
1996 struct btrfs_key
*key
)
1999 while (level
< BTRFS_MAX_LEVEL
) {
2000 if (!path
->nodes
[level
])
2002 if (path
->slots
[level
] + 1 <
2003 btrfs_header_nritems(path
->nodes
[level
])) {
2004 btrfs_node_key_to_cpu(path
->nodes
[level
], key
,
2005 path
->slots
[level
] + 1);
2014 * merge the relocated tree blocks in reloc tree with corresponding
2017 static noinline_for_stack
int merge_reloc_root(struct reloc_control
*rc
,
2018 struct btrfs_root
*root
)
2020 LIST_HEAD(inode_list
);
2021 struct btrfs_key key
;
2022 struct btrfs_key next_key
;
2023 struct btrfs_trans_handle
*trans
;
2024 struct btrfs_root
*reloc_root
;
2025 struct btrfs_root_item
*root_item
;
2026 struct btrfs_path
*path
;
2027 struct extent_buffer
*leaf
;
2036 path
= btrfs_alloc_path();
2041 reloc_root
= root
->reloc_root
;
2042 root_item
= &reloc_root
->root_item
;
2044 if (btrfs_disk_key_objectid(&root_item
->drop_progress
) == 0) {
2045 level
= btrfs_root_level(root_item
);
2046 extent_buffer_get(reloc_root
->node
);
2047 path
->nodes
[level
] = reloc_root
->node
;
2048 path
->slots
[level
] = 0;
2050 btrfs_disk_key_to_cpu(&key
, &root_item
->drop_progress
);
2052 level
= root_item
->drop_level
;
2054 path
->lowest_level
= level
;
2055 ret
= btrfs_search_slot(NULL
, reloc_root
, &key
, path
, 0, 0);
2056 path
->lowest_level
= 0;
2058 btrfs_free_path(path
);
2062 btrfs_node_key_to_cpu(path
->nodes
[level
], &next_key
,
2063 path
->slots
[level
]);
2064 WARN_ON(memcmp(&key
, &next_key
, sizeof(key
)));
2066 btrfs_unlock_up_safe(path
, 0);
2069 min_reserved
= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2070 memset(&next_key
, 0, sizeof(next_key
));
2073 trans
= btrfs_start_transaction(root
, 0);
2074 BUG_ON(IS_ERR(trans
));
2075 trans
->block_rsv
= rc
->block_rsv
;
2077 ret
= btrfs_block_rsv_refill(root
, rc
->block_rsv
, min_reserved
);
2079 BUG_ON(ret
!= -EAGAIN
);
2080 ret
= btrfs_commit_transaction(trans
, root
);
2088 ret
= walk_down_reloc_tree(reloc_root
, path
, &level
);
2096 if (!find_next_key(path
, level
, &key
) &&
2097 btrfs_comp_cpu_keys(&next_key
, &key
) >= 0) {
2100 ret
= replace_path(trans
, root
, reloc_root
, path
,
2101 &next_key
, level
, max_level
);
2110 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
2111 path
->slots
[level
]);
2115 ret
= walk_up_reloc_tree(reloc_root
, path
, &level
);
2121 * save the merging progress in the drop_progress.
2122 * this is OK since root refs == 1 in this case.
2124 btrfs_node_key(path
->nodes
[level
], &root_item
->drop_progress
,
2125 path
->slots
[level
]);
2126 root_item
->drop_level
= level
;
2128 nr
= trans
->blocks_used
;
2129 btrfs_end_transaction_throttle(trans
, root
);
2131 btrfs_btree_balance_dirty(root
, nr
);
2133 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2134 invalidate_extent_cache(root
, &key
, &next_key
);
2138 * handle the case only one block in the fs tree need to be
2139 * relocated and the block is tree root.
2141 leaf
= btrfs_lock_root_node(root
);
2142 ret
= btrfs_cow_block(trans
, root
, leaf
, NULL
, 0, &leaf
);
2143 btrfs_tree_unlock(leaf
);
2144 free_extent_buffer(leaf
);
2148 btrfs_free_path(path
);
2151 memset(&root_item
->drop_progress
, 0,
2152 sizeof(root_item
->drop_progress
));
2153 root_item
->drop_level
= 0;
2154 btrfs_set_root_refs(root_item
, 0);
2155 btrfs_update_reloc_root(trans
, root
);
2158 nr
= trans
->blocks_used
;
2159 btrfs_end_transaction_throttle(trans
, root
);
2161 btrfs_btree_balance_dirty(root
, nr
);
2163 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2164 invalidate_extent_cache(root
, &key
, &next_key
);
2169 static noinline_for_stack
2170 int prepare_to_merge(struct reloc_control
*rc
, int err
)
2172 struct btrfs_root
*root
= rc
->extent_root
;
2173 struct btrfs_root
*reloc_root
;
2174 struct btrfs_trans_handle
*trans
;
2175 LIST_HEAD(reloc_roots
);
2179 mutex_lock(&root
->fs_info
->reloc_mutex
);
2180 rc
->merging_rsv_size
+= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2181 rc
->merging_rsv_size
+= rc
->nodes_relocated
* 2;
2182 mutex_unlock(&root
->fs_info
->reloc_mutex
);
2186 num_bytes
= rc
->merging_rsv_size
;
2187 ret
= btrfs_block_rsv_add(root
, rc
->block_rsv
, num_bytes
);
2192 trans
= btrfs_join_transaction(rc
->extent_root
);
2193 if (IS_ERR(trans
)) {
2195 btrfs_block_rsv_release(rc
->extent_root
,
2196 rc
->block_rsv
, num_bytes
);
2197 return PTR_ERR(trans
);
2201 if (num_bytes
!= rc
->merging_rsv_size
) {
2202 btrfs_end_transaction(trans
, rc
->extent_root
);
2203 btrfs_block_rsv_release(rc
->extent_root
,
2204 rc
->block_rsv
, num_bytes
);
2209 rc
->merge_reloc_tree
= 1;
2211 while (!list_empty(&rc
->reloc_roots
)) {
2212 reloc_root
= list_entry(rc
->reloc_roots
.next
,
2213 struct btrfs_root
, root_list
);
2214 list_del_init(&reloc_root
->root_list
);
2216 root
= read_fs_root(reloc_root
->fs_info
,
2217 reloc_root
->root_key
.offset
);
2218 BUG_ON(IS_ERR(root
));
2219 BUG_ON(root
->reloc_root
!= reloc_root
);
2222 * set reference count to 1, so btrfs_recover_relocation
2223 * knows it should resumes merging
2226 btrfs_set_root_refs(&reloc_root
->root_item
, 1);
2227 btrfs_update_reloc_root(trans
, root
);
2229 list_add(&reloc_root
->root_list
, &reloc_roots
);
2232 list_splice(&reloc_roots
, &rc
->reloc_roots
);
2235 btrfs_commit_transaction(trans
, rc
->extent_root
);
2237 btrfs_end_transaction(trans
, rc
->extent_root
);
2241 static noinline_for_stack
2242 int merge_reloc_roots(struct reloc_control
*rc
)
2244 struct btrfs_root
*root
;
2245 struct btrfs_root
*reloc_root
;
2246 LIST_HEAD(reloc_roots
);
2250 root
= rc
->extent_root
;
2253 * this serializes us with btrfs_record_root_in_transaction,
2254 * we have to make sure nobody is in the middle of
2255 * adding their roots to the list while we are
2258 mutex_lock(&root
->fs_info
->reloc_mutex
);
2259 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
2260 mutex_unlock(&root
->fs_info
->reloc_mutex
);
2262 while (!list_empty(&reloc_roots
)) {
2264 reloc_root
= list_entry(reloc_roots
.next
,
2265 struct btrfs_root
, root_list
);
2267 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
2268 root
= read_fs_root(reloc_root
->fs_info
,
2269 reloc_root
->root_key
.offset
);
2270 BUG_ON(IS_ERR(root
));
2271 BUG_ON(root
->reloc_root
!= reloc_root
);
2273 ret
= merge_reloc_root(rc
, root
);
2276 list_del_init(&reloc_root
->root_list
);
2278 ret
= btrfs_drop_snapshot(reloc_root
, rc
->block_rsv
, 0, 1);
2286 BUG_ON(!RB_EMPTY_ROOT(&rc
->reloc_root_tree
.rb_root
));
2290 static void free_block_list(struct rb_root
*blocks
)
2292 struct tree_block
*block
;
2293 struct rb_node
*rb_node
;
2294 while ((rb_node
= rb_first(blocks
))) {
2295 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2296 rb_erase(rb_node
, blocks
);
2301 static int record_reloc_root_in_trans(struct btrfs_trans_handle
*trans
,
2302 struct btrfs_root
*reloc_root
)
2304 struct btrfs_root
*root
;
2306 if (reloc_root
->last_trans
== trans
->transid
)
2309 root
= read_fs_root(reloc_root
->fs_info
, reloc_root
->root_key
.offset
);
2310 BUG_ON(IS_ERR(root
));
2311 BUG_ON(root
->reloc_root
!= reloc_root
);
2313 return btrfs_record_root_in_trans(trans
, root
);
2316 static noinline_for_stack
2317 struct btrfs_root
*select_reloc_root(struct btrfs_trans_handle
*trans
,
2318 struct reloc_control
*rc
,
2319 struct backref_node
*node
,
2320 struct backref_edge
*edges
[], int *nr
)
2322 struct backref_node
*next
;
2323 struct btrfs_root
*root
;
2329 next
= walk_up_backref(next
, edges
, &index
);
2332 BUG_ON(!root
->ref_cows
);
2334 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
2335 record_reloc_root_in_trans(trans
, root
);
2339 btrfs_record_root_in_trans(trans
, root
);
2340 root
= root
->reloc_root
;
2342 if (next
->new_bytenr
!= root
->node
->start
) {
2343 BUG_ON(next
->new_bytenr
);
2344 BUG_ON(!list_empty(&next
->list
));
2345 next
->new_bytenr
= root
->node
->start
;
2347 list_add_tail(&next
->list
,
2348 &rc
->backref_cache
.changed
);
2349 __mark_block_processed(rc
, next
);
2355 next
= walk_down_backref(edges
, &index
);
2356 if (!next
|| next
->level
<= node
->level
)
2364 /* setup backref node path for btrfs_reloc_cow_block */
2366 rc
->backref_cache
.path
[next
->level
] = next
;
2369 next
= edges
[index
]->node
[UPPER
];
2375 * select a tree root for relocation. return NULL if the block
2376 * is reference counted. we should use do_relocation() in this
2377 * case. return a tree root pointer if the block isn't reference
2378 * counted. return -ENOENT if the block is root of reloc tree.
2380 static noinline_for_stack
2381 struct btrfs_root
*select_one_root(struct btrfs_trans_handle
*trans
,
2382 struct backref_node
*node
)
2384 struct backref_node
*next
;
2385 struct btrfs_root
*root
;
2386 struct btrfs_root
*fs_root
= NULL
;
2387 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2393 next
= walk_up_backref(next
, edges
, &index
);
2397 /* no other choice for non-references counted tree */
2398 if (!root
->ref_cows
)
2401 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
)
2407 next
= walk_down_backref(edges
, &index
);
2408 if (!next
|| next
->level
<= node
->level
)
2413 return ERR_PTR(-ENOENT
);
2417 static noinline_for_stack
2418 u64
calcu_metadata_size(struct reloc_control
*rc
,
2419 struct backref_node
*node
, int reserve
)
2421 struct backref_node
*next
= node
;
2422 struct backref_edge
*edge
;
2423 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2427 BUG_ON(reserve
&& node
->processed
);
2432 if (next
->processed
&& (reserve
|| next
!= node
))
2435 num_bytes
+= btrfs_level_size(rc
->extent_root
,
2438 if (list_empty(&next
->upper
))
2441 edge
= list_entry(next
->upper
.next
,
2442 struct backref_edge
, list
[LOWER
]);
2443 edges
[index
++] = edge
;
2444 next
= edge
->node
[UPPER
];
2446 next
= walk_down_backref(edges
, &index
);
2451 static int reserve_metadata_space(struct btrfs_trans_handle
*trans
,
2452 struct reloc_control
*rc
,
2453 struct backref_node
*node
)
2455 struct btrfs_root
*root
= rc
->extent_root
;
2459 num_bytes
= calcu_metadata_size(rc
, node
, 1) * 2;
2461 trans
->block_rsv
= rc
->block_rsv
;
2462 ret
= btrfs_block_rsv_add(root
, rc
->block_rsv
, num_bytes
);
2465 rc
->commit_transaction
= 1;
2472 static void release_metadata_space(struct reloc_control
*rc
,
2473 struct backref_node
*node
)
2475 u64 num_bytes
= calcu_metadata_size(rc
, node
, 0) * 2;
2476 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, num_bytes
);
2480 * relocate a block tree, and then update pointers in upper level
2481 * blocks that reference the block to point to the new location.
2483 * if called by link_to_upper, the block has already been relocated.
2484 * in that case this function just updates pointers.
2486 static int do_relocation(struct btrfs_trans_handle
*trans
,
2487 struct reloc_control
*rc
,
2488 struct backref_node
*node
,
2489 struct btrfs_key
*key
,
2490 struct btrfs_path
*path
, int lowest
)
2492 struct backref_node
*upper
;
2493 struct backref_edge
*edge
;
2494 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2495 struct btrfs_root
*root
;
2496 struct extent_buffer
*eb
;
2505 BUG_ON(lowest
&& node
->eb
);
2507 path
->lowest_level
= node
->level
+ 1;
2508 rc
->backref_cache
.path
[node
->level
] = node
;
2509 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
]) {
2512 upper
= edge
->node
[UPPER
];
2513 root
= select_reloc_root(trans
, rc
, upper
, edges
, &nr
);
2516 if (upper
->eb
&& !upper
->locked
) {
2518 ret
= btrfs_bin_search(upper
->eb
, key
,
2519 upper
->level
, &slot
);
2521 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2522 if (node
->eb
->start
== bytenr
)
2525 drop_node_buffer(upper
);
2529 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2537 upper
->eb
= path
->nodes
[upper
->level
];
2538 path
->nodes
[upper
->level
] = NULL
;
2540 BUG_ON(upper
->eb
!= path
->nodes
[upper
->level
]);
2544 path
->locks
[upper
->level
] = 0;
2546 slot
= path
->slots
[upper
->level
];
2547 btrfs_release_path(path
);
2549 ret
= btrfs_bin_search(upper
->eb
, key
, upper
->level
,
2554 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2556 BUG_ON(bytenr
!= node
->bytenr
);
2558 if (node
->eb
->start
== bytenr
)
2562 blocksize
= btrfs_level_size(root
, node
->level
);
2563 generation
= btrfs_node_ptr_generation(upper
->eb
, slot
);
2564 eb
= read_tree_block(root
, bytenr
, blocksize
, generation
);
2569 btrfs_tree_lock(eb
);
2570 btrfs_set_lock_blocking(eb
);
2573 ret
= btrfs_cow_block(trans
, root
, eb
, upper
->eb
,
2575 btrfs_tree_unlock(eb
);
2576 free_extent_buffer(eb
);
2581 BUG_ON(node
->eb
!= eb
);
2583 btrfs_set_node_blockptr(upper
->eb
, slot
,
2585 btrfs_set_node_ptr_generation(upper
->eb
, slot
,
2587 btrfs_mark_buffer_dirty(upper
->eb
);
2589 ret
= btrfs_inc_extent_ref(trans
, root
,
2590 node
->eb
->start
, blocksize
,
2592 btrfs_header_owner(upper
->eb
),
2596 ret
= btrfs_drop_subtree(trans
, root
, eb
, upper
->eb
);
2600 if (!upper
->pending
)
2601 drop_node_buffer(upper
);
2603 unlock_node_buffer(upper
);
2608 if (!err
&& node
->pending
) {
2609 drop_node_buffer(node
);
2610 list_move_tail(&node
->list
, &rc
->backref_cache
.changed
);
2614 path
->lowest_level
= 0;
2615 BUG_ON(err
== -ENOSPC
);
2619 static int link_to_upper(struct btrfs_trans_handle
*trans
,
2620 struct reloc_control
*rc
,
2621 struct backref_node
*node
,
2622 struct btrfs_path
*path
)
2624 struct btrfs_key key
;
2626 btrfs_node_key_to_cpu(node
->eb
, &key
, 0);
2627 return do_relocation(trans
, rc
, node
, &key
, path
, 0);
2630 static int finish_pending_nodes(struct btrfs_trans_handle
*trans
,
2631 struct reloc_control
*rc
,
2632 struct btrfs_path
*path
, int err
)
2635 struct backref_cache
*cache
= &rc
->backref_cache
;
2636 struct backref_node
*node
;
2640 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
2641 while (!list_empty(&cache
->pending
[level
])) {
2642 node
= list_entry(cache
->pending
[level
].next
,
2643 struct backref_node
, list
);
2644 list_move_tail(&node
->list
, &list
);
2645 BUG_ON(!node
->pending
);
2648 ret
= link_to_upper(trans
, rc
, node
, path
);
2653 list_splice_init(&list
, &cache
->pending
[level
]);
2658 static void mark_block_processed(struct reloc_control
*rc
,
2659 u64 bytenr
, u32 blocksize
)
2661 set_extent_bits(&rc
->processed_blocks
, bytenr
, bytenr
+ blocksize
- 1,
2662 EXTENT_DIRTY
, GFP_NOFS
);
2665 static void __mark_block_processed(struct reloc_control
*rc
,
2666 struct backref_node
*node
)
2669 if (node
->level
== 0 ||
2670 in_block_group(node
->bytenr
, rc
->block_group
)) {
2671 blocksize
= btrfs_level_size(rc
->extent_root
, node
->level
);
2672 mark_block_processed(rc
, node
->bytenr
, blocksize
);
2674 node
->processed
= 1;
2678 * mark a block and all blocks directly/indirectly reference the block
2681 static void update_processed_blocks(struct reloc_control
*rc
,
2682 struct backref_node
*node
)
2684 struct backref_node
*next
= node
;
2685 struct backref_edge
*edge
;
2686 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2692 if (next
->processed
)
2695 __mark_block_processed(rc
, next
);
2697 if (list_empty(&next
->upper
))
2700 edge
= list_entry(next
->upper
.next
,
2701 struct backref_edge
, list
[LOWER
]);
2702 edges
[index
++] = edge
;
2703 next
= edge
->node
[UPPER
];
2705 next
= walk_down_backref(edges
, &index
);
2709 static int tree_block_processed(u64 bytenr
, u32 blocksize
,
2710 struct reloc_control
*rc
)
2712 if (test_range_bit(&rc
->processed_blocks
, bytenr
,
2713 bytenr
+ blocksize
- 1, EXTENT_DIRTY
, 1, NULL
))
2718 static int get_tree_block_key(struct reloc_control
*rc
,
2719 struct tree_block
*block
)
2721 struct extent_buffer
*eb
;
2723 BUG_ON(block
->key_ready
);
2724 eb
= read_tree_block(rc
->extent_root
, block
->bytenr
,
2725 block
->key
.objectid
, block
->key
.offset
);
2727 WARN_ON(btrfs_header_level(eb
) != block
->level
);
2728 if (block
->level
== 0)
2729 btrfs_item_key_to_cpu(eb
, &block
->key
, 0);
2731 btrfs_node_key_to_cpu(eb
, &block
->key
, 0);
2732 free_extent_buffer(eb
);
2733 block
->key_ready
= 1;
2737 static int reada_tree_block(struct reloc_control
*rc
,
2738 struct tree_block
*block
)
2740 BUG_ON(block
->key_ready
);
2741 readahead_tree_block(rc
->extent_root
, block
->bytenr
,
2742 block
->key
.objectid
, block
->key
.offset
);
2747 * helper function to relocate a tree block
2749 static int relocate_tree_block(struct btrfs_trans_handle
*trans
,
2750 struct reloc_control
*rc
,
2751 struct backref_node
*node
,
2752 struct btrfs_key
*key
,
2753 struct btrfs_path
*path
)
2755 struct btrfs_root
*root
;
2762 BUG_ON(node
->processed
);
2763 root
= select_one_root(trans
, node
);
2764 if (root
== ERR_PTR(-ENOENT
)) {
2765 update_processed_blocks(rc
, node
);
2769 if (!root
|| root
->ref_cows
) {
2770 ret
= reserve_metadata_space(trans
, rc
, node
);
2777 if (root
->ref_cows
) {
2778 BUG_ON(node
->new_bytenr
);
2779 BUG_ON(!list_empty(&node
->list
));
2780 btrfs_record_root_in_trans(trans
, root
);
2781 root
= root
->reloc_root
;
2782 node
->new_bytenr
= root
->node
->start
;
2784 list_add_tail(&node
->list
, &rc
->backref_cache
.changed
);
2786 path
->lowest_level
= node
->level
;
2787 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2788 btrfs_release_path(path
);
2793 update_processed_blocks(rc
, node
);
2795 ret
= do_relocation(trans
, rc
, node
, key
, path
, 1);
2798 if (ret
|| node
->level
== 0 || node
->cowonly
) {
2800 release_metadata_space(rc
, node
);
2801 remove_backref_node(&rc
->backref_cache
, node
);
2807 * relocate a list of blocks
2809 static noinline_for_stack
2810 int relocate_tree_blocks(struct btrfs_trans_handle
*trans
,
2811 struct reloc_control
*rc
, struct rb_root
*blocks
)
2813 struct backref_node
*node
;
2814 struct btrfs_path
*path
;
2815 struct tree_block
*block
;
2816 struct rb_node
*rb_node
;
2820 path
= btrfs_alloc_path();
2824 rb_node
= rb_first(blocks
);
2826 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2827 if (!block
->key_ready
)
2828 reada_tree_block(rc
, block
);
2829 rb_node
= rb_next(rb_node
);
2832 rb_node
= rb_first(blocks
);
2834 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2835 if (!block
->key_ready
)
2836 get_tree_block_key(rc
, block
);
2837 rb_node
= rb_next(rb_node
);
2840 rb_node
= rb_first(blocks
);
2842 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2844 node
= build_backref_tree(rc
, &block
->key
,
2845 block
->level
, block
->bytenr
);
2847 err
= PTR_ERR(node
);
2851 ret
= relocate_tree_block(trans
, rc
, node
, &block
->key
,
2854 if (ret
!= -EAGAIN
|| rb_node
== rb_first(blocks
))
2858 rb_node
= rb_next(rb_node
);
2861 free_block_list(blocks
);
2862 err
= finish_pending_nodes(trans
, rc
, path
, err
);
2864 btrfs_free_path(path
);
2868 static noinline_for_stack
2869 int prealloc_file_extent_cluster(struct inode
*inode
,
2870 struct file_extent_cluster
*cluster
)
2875 u64 offset
= BTRFS_I(inode
)->index_cnt
;
2880 BUG_ON(cluster
->start
!= cluster
->boundary
[0]);
2881 mutex_lock(&inode
->i_mutex
);
2883 ret
= btrfs_check_data_free_space(inode
, cluster
->end
+
2884 1 - cluster
->start
);
2888 while (nr
< cluster
->nr
) {
2889 start
= cluster
->boundary
[nr
] - offset
;
2890 if (nr
+ 1 < cluster
->nr
)
2891 end
= cluster
->boundary
[nr
+ 1] - 1 - offset
;
2893 end
= cluster
->end
- offset
;
2895 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2896 num_bytes
= end
+ 1 - start
;
2897 ret
= btrfs_prealloc_file_range(inode
, 0, start
,
2898 num_bytes
, num_bytes
,
2899 end
+ 1, &alloc_hint
);
2900 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2905 btrfs_free_reserved_data_space(inode
, cluster
->end
+
2906 1 - cluster
->start
);
2908 mutex_unlock(&inode
->i_mutex
);
2912 static noinline_for_stack
2913 int setup_extent_mapping(struct inode
*inode
, u64 start
, u64 end
,
2916 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
2917 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2918 struct extent_map
*em
;
2921 em
= alloc_extent_map();
2926 em
->len
= end
+ 1 - start
;
2927 em
->block_len
= em
->len
;
2928 em
->block_start
= block_start
;
2929 em
->bdev
= root
->fs_info
->fs_devices
->latest_bdev
;
2930 set_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
2932 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2934 write_lock(&em_tree
->lock
);
2935 ret
= add_extent_mapping(em_tree
, em
);
2936 write_unlock(&em_tree
->lock
);
2937 if (ret
!= -EEXIST
) {
2938 free_extent_map(em
);
2941 btrfs_drop_extent_cache(inode
, start
, end
, 0);
2943 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2947 static int relocate_file_extent_cluster(struct inode
*inode
,
2948 struct file_extent_cluster
*cluster
)
2952 u64 offset
= BTRFS_I(inode
)->index_cnt
;
2953 unsigned long index
;
2954 unsigned long last_index
;
2956 struct file_ra_state
*ra
;
2957 gfp_t mask
= btrfs_alloc_write_mask(inode
->i_mapping
);
2964 ra
= kzalloc(sizeof(*ra
), GFP_NOFS
);
2968 ret
= prealloc_file_extent_cluster(inode
, cluster
);
2972 file_ra_state_init(ra
, inode
->i_mapping
);
2974 ret
= setup_extent_mapping(inode
, cluster
->start
- offset
,
2975 cluster
->end
- offset
, cluster
->start
);
2979 index
= (cluster
->start
- offset
) >> PAGE_CACHE_SHIFT
;
2980 last_index
= (cluster
->end
- offset
) >> PAGE_CACHE_SHIFT
;
2981 while (index
<= last_index
) {
2982 ret
= btrfs_delalloc_reserve_metadata(inode
, PAGE_CACHE_SIZE
);
2986 page
= find_lock_page(inode
->i_mapping
, index
);
2988 page_cache_sync_readahead(inode
->i_mapping
,
2990 last_index
+ 1 - index
);
2991 page
= find_or_create_page(inode
->i_mapping
, index
,
2994 btrfs_delalloc_release_metadata(inode
,
3001 if (PageReadahead(page
)) {
3002 page_cache_async_readahead(inode
->i_mapping
,
3003 ra
, NULL
, page
, index
,
3004 last_index
+ 1 - index
);
3007 if (!PageUptodate(page
)) {
3008 btrfs_readpage(NULL
, page
);
3010 if (!PageUptodate(page
)) {
3012 page_cache_release(page
);
3013 btrfs_delalloc_release_metadata(inode
,
3020 page_start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
3021 page_end
= page_start
+ PAGE_CACHE_SIZE
- 1;
3023 lock_extent(&BTRFS_I(inode
)->io_tree
, page_start
, page_end
);
3025 set_page_extent_mapped(page
);
3027 if (nr
< cluster
->nr
&&
3028 page_start
+ offset
== cluster
->boundary
[nr
]) {
3029 set_extent_bits(&BTRFS_I(inode
)->io_tree
,
3030 page_start
, page_end
,
3031 EXTENT_BOUNDARY
, GFP_NOFS
);
3035 btrfs_set_extent_delalloc(inode
, page_start
, page_end
, NULL
);
3036 set_page_dirty(page
);
3038 unlock_extent(&BTRFS_I(inode
)->io_tree
,
3039 page_start
, page_end
);
3041 page_cache_release(page
);
3044 balance_dirty_pages_ratelimited(inode
->i_mapping
);
3045 btrfs_throttle(BTRFS_I(inode
)->root
);
3047 WARN_ON(nr
!= cluster
->nr
);
3053 static noinline_for_stack
3054 int relocate_data_extent(struct inode
*inode
, struct btrfs_key
*extent_key
,
3055 struct file_extent_cluster
*cluster
)
3059 if (cluster
->nr
> 0 && extent_key
->objectid
!= cluster
->end
+ 1) {
3060 ret
= relocate_file_extent_cluster(inode
, cluster
);
3067 cluster
->start
= extent_key
->objectid
;
3069 BUG_ON(cluster
->nr
>= MAX_EXTENTS
);
3070 cluster
->end
= extent_key
->objectid
+ extent_key
->offset
- 1;
3071 cluster
->boundary
[cluster
->nr
] = extent_key
->objectid
;
3074 if (cluster
->nr
>= MAX_EXTENTS
) {
3075 ret
= relocate_file_extent_cluster(inode
, cluster
);
3083 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3084 static int get_ref_objectid_v0(struct reloc_control
*rc
,
3085 struct btrfs_path
*path
,
3086 struct btrfs_key
*extent_key
,
3087 u64
*ref_objectid
, int *path_change
)
3089 struct btrfs_key key
;
3090 struct extent_buffer
*leaf
;
3091 struct btrfs_extent_ref_v0
*ref0
;
3095 leaf
= path
->nodes
[0];
3096 slot
= path
->slots
[0];
3098 if (slot
>= btrfs_header_nritems(leaf
)) {
3099 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3103 leaf
= path
->nodes
[0];
3104 slot
= path
->slots
[0];
3108 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
3109 if (key
.objectid
!= extent_key
->objectid
)
3112 if (key
.type
!= BTRFS_EXTENT_REF_V0_KEY
) {
3116 ref0
= btrfs_item_ptr(leaf
, slot
,
3117 struct btrfs_extent_ref_v0
);
3118 *ref_objectid
= btrfs_ref_objectid_v0(leaf
, ref0
);
3126 * helper to add a tree block to the list.
3127 * the major work is getting the generation and level of the block
3129 static int add_tree_block(struct reloc_control
*rc
,
3130 struct btrfs_key
*extent_key
,
3131 struct btrfs_path
*path
,
3132 struct rb_root
*blocks
)
3134 struct extent_buffer
*eb
;
3135 struct btrfs_extent_item
*ei
;
3136 struct btrfs_tree_block_info
*bi
;
3137 struct tree_block
*block
;
3138 struct rb_node
*rb_node
;
3143 eb
= path
->nodes
[0];
3144 item_size
= btrfs_item_size_nr(eb
, path
->slots
[0]);
3146 if (item_size
>= sizeof(*ei
) + sizeof(*bi
)) {
3147 ei
= btrfs_item_ptr(eb
, path
->slots
[0],
3148 struct btrfs_extent_item
);
3149 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
3150 generation
= btrfs_extent_generation(eb
, ei
);
3151 level
= btrfs_tree_block_level(eb
, bi
);
3153 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3157 BUG_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
3158 ret
= get_ref_objectid_v0(rc
, path
, extent_key
,
3162 BUG_ON(ref_owner
>= BTRFS_MAX_LEVEL
);
3163 level
= (int)ref_owner
;
3164 /* FIXME: get real generation */
3171 btrfs_release_path(path
);
3173 BUG_ON(level
== -1);
3175 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3179 block
->bytenr
= extent_key
->objectid
;
3180 block
->key
.objectid
= extent_key
->offset
;
3181 block
->key
.offset
= generation
;
3182 block
->level
= level
;
3183 block
->key_ready
= 0;
3185 rb_node
= tree_insert(blocks
, block
->bytenr
, &block
->rb_node
);
3187 backref_tree_panic(rb_node
, -EEXIST
, block
->bytenr
);
3193 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3195 static int __add_tree_block(struct reloc_control
*rc
,
3196 u64 bytenr
, u32 blocksize
,
3197 struct rb_root
*blocks
)
3199 struct btrfs_path
*path
;
3200 struct btrfs_key key
;
3203 if (tree_block_processed(bytenr
, blocksize
, rc
))
3206 if (tree_search(blocks
, bytenr
))
3209 path
= btrfs_alloc_path();
3213 key
.objectid
= bytenr
;
3214 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3215 key
.offset
= blocksize
;
3217 path
->search_commit_root
= 1;
3218 path
->skip_locking
= 1;
3219 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
, 0, 0);
3224 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, path
->slots
[0]);
3225 ret
= add_tree_block(rc
, &key
, path
, blocks
);
3227 btrfs_free_path(path
);
3232 * helper to check if the block use full backrefs for pointers in it
3234 static int block_use_full_backref(struct reloc_control
*rc
,
3235 struct extent_buffer
*eb
)
3240 if (btrfs_header_flag(eb
, BTRFS_HEADER_FLAG_RELOC
) ||
3241 btrfs_header_backref_rev(eb
) < BTRFS_MIXED_BACKREF_REV
)
3244 ret
= btrfs_lookup_extent_info(NULL
, rc
->extent_root
,
3245 eb
->start
, eb
->len
, NULL
, &flags
);
3248 if (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
)
3255 static int delete_block_group_cache(struct btrfs_fs_info
*fs_info
,
3256 struct inode
*inode
, u64 ino
)
3258 struct btrfs_key key
;
3259 struct btrfs_path
*path
;
3260 struct btrfs_root
*root
= fs_info
->tree_root
;
3261 struct btrfs_trans_handle
*trans
;
3269 key
.type
= BTRFS_INODE_ITEM_KEY
;
3272 inode
= btrfs_iget(fs_info
->sb
, &key
, root
, NULL
);
3273 if (IS_ERR(inode
) || is_bad_inode(inode
)) {
3280 path
= btrfs_alloc_path();
3286 trans
= btrfs_join_transaction(root
);
3287 if (IS_ERR(trans
)) {
3288 btrfs_free_path(path
);
3289 ret
= PTR_ERR(trans
);
3293 ret
= btrfs_truncate_free_space_cache(root
, trans
, path
, inode
);
3295 btrfs_free_path(path
);
3296 nr
= trans
->blocks_used
;
3297 btrfs_end_transaction(trans
, root
);
3298 btrfs_btree_balance_dirty(root
, nr
);
3305 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3306 * this function scans fs tree to find blocks reference the data extent
3308 static int find_data_references(struct reloc_control
*rc
,
3309 struct btrfs_key
*extent_key
,
3310 struct extent_buffer
*leaf
,
3311 struct btrfs_extent_data_ref
*ref
,
3312 struct rb_root
*blocks
)
3314 struct btrfs_path
*path
;
3315 struct tree_block
*block
;
3316 struct btrfs_root
*root
;
3317 struct btrfs_file_extent_item
*fi
;
3318 struct rb_node
*rb_node
;
3319 struct btrfs_key key
;
3330 ref_root
= btrfs_extent_data_ref_root(leaf
, ref
);
3331 ref_objectid
= btrfs_extent_data_ref_objectid(leaf
, ref
);
3332 ref_offset
= btrfs_extent_data_ref_offset(leaf
, ref
);
3333 ref_count
= btrfs_extent_data_ref_count(leaf
, ref
);
3336 * This is an extent belonging to the free space cache, lets just delete
3337 * it and redo the search.
3339 if (ref_root
== BTRFS_ROOT_TREE_OBJECTID
) {
3340 ret
= delete_block_group_cache(rc
->extent_root
->fs_info
,
3341 NULL
, ref_objectid
);
3347 path
= btrfs_alloc_path();
3352 root
= read_fs_root(rc
->extent_root
->fs_info
, ref_root
);
3354 err
= PTR_ERR(root
);
3358 key
.objectid
= ref_objectid
;
3359 key
.type
= BTRFS_EXTENT_DATA_KEY
;
3360 if (ref_offset
> ((u64
)-1 << 32))
3363 key
.offset
= ref_offset
;
3365 path
->search_commit_root
= 1;
3366 path
->skip_locking
= 1;
3367 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
3373 leaf
= path
->nodes
[0];
3374 nritems
= btrfs_header_nritems(leaf
);
3376 * the references in tree blocks that use full backrefs
3377 * are not counted in
3379 if (block_use_full_backref(rc
, leaf
))
3383 rb_node
= tree_search(blocks
, leaf
->start
);
3388 path
->slots
[0] = nritems
;
3391 while (ref_count
> 0) {
3392 while (path
->slots
[0] >= nritems
) {
3393 ret
= btrfs_next_leaf(root
, path
);
3403 leaf
= path
->nodes
[0];
3404 nritems
= btrfs_header_nritems(leaf
);
3407 if (block_use_full_backref(rc
, leaf
))
3411 rb_node
= tree_search(blocks
, leaf
->start
);
3416 path
->slots
[0] = nritems
;
3420 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3421 if (key
.objectid
!= ref_objectid
||
3422 key
.type
!= BTRFS_EXTENT_DATA_KEY
) {
3427 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3428 struct btrfs_file_extent_item
);
3430 if (btrfs_file_extent_type(leaf
, fi
) ==
3431 BTRFS_FILE_EXTENT_INLINE
)
3434 if (btrfs_file_extent_disk_bytenr(leaf
, fi
) !=
3435 extent_key
->objectid
)
3438 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
3439 if (key
.offset
!= ref_offset
)
3447 if (!tree_block_processed(leaf
->start
, leaf
->len
, rc
)) {
3448 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3453 block
->bytenr
= leaf
->start
;
3454 btrfs_item_key_to_cpu(leaf
, &block
->key
, 0);
3456 block
->key_ready
= 1;
3457 rb_node
= tree_insert(blocks
, block
->bytenr
,
3460 backref_tree_panic(rb_node
, -EEXIST
,
3466 path
->slots
[0] = nritems
;
3472 btrfs_free_path(path
);
3477 * hepler to find all tree blocks that reference a given data extent
3479 static noinline_for_stack
3480 int add_data_references(struct reloc_control
*rc
,
3481 struct btrfs_key
*extent_key
,
3482 struct btrfs_path
*path
,
3483 struct rb_root
*blocks
)
3485 struct btrfs_key key
;
3486 struct extent_buffer
*eb
;
3487 struct btrfs_extent_data_ref
*dref
;
3488 struct btrfs_extent_inline_ref
*iref
;
3491 u32 blocksize
= btrfs_level_size(rc
->extent_root
, 0);
3495 eb
= path
->nodes
[0];
3496 ptr
= btrfs_item_ptr_offset(eb
, path
->slots
[0]);
3497 end
= ptr
+ btrfs_item_size_nr(eb
, path
->slots
[0]);
3498 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3499 if (ptr
+ sizeof(struct btrfs_extent_item_v0
) == end
)
3503 ptr
+= sizeof(struct btrfs_extent_item
);
3506 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
3507 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
3508 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3509 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
3510 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3512 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3513 dref
= (struct btrfs_extent_data_ref
*)(&iref
->offset
);
3514 ret
= find_data_references(rc
, extent_key
,
3519 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
3525 eb
= path
->nodes
[0];
3526 if (path
->slots
[0] >= btrfs_header_nritems(eb
)) {
3527 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3534 eb
= path
->nodes
[0];
3537 btrfs_item_key_to_cpu(eb
, &key
, path
->slots
[0]);
3538 if (key
.objectid
!= extent_key
->objectid
)
3541 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3542 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
||
3543 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
3545 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
3546 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3548 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3550 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3551 dref
= btrfs_item_ptr(eb
, path
->slots
[0],
3552 struct btrfs_extent_data_ref
);
3553 ret
= find_data_references(rc
, extent_key
,
3564 btrfs_release_path(path
);
3566 free_block_list(blocks
);
3571 * hepler to find next unprocessed extent
3573 static noinline_for_stack
3574 int find_next_extent(struct btrfs_trans_handle
*trans
,
3575 struct reloc_control
*rc
, struct btrfs_path
*path
,
3576 struct btrfs_key
*extent_key
)
3578 struct btrfs_key key
;
3579 struct extent_buffer
*leaf
;
3580 u64 start
, end
, last
;
3583 last
= rc
->block_group
->key
.objectid
+ rc
->block_group
->key
.offset
;
3586 if (rc
->search_start
>= last
) {
3591 key
.objectid
= rc
->search_start
;
3592 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3595 path
->search_commit_root
= 1;
3596 path
->skip_locking
= 1;
3597 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
,
3602 leaf
= path
->nodes
[0];
3603 if (path
->slots
[0] >= btrfs_header_nritems(leaf
)) {
3604 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3607 leaf
= path
->nodes
[0];
3610 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3611 if (key
.objectid
>= last
) {
3616 if (key
.type
!= BTRFS_EXTENT_ITEM_KEY
||
3617 key
.objectid
+ key
.offset
<= rc
->search_start
) {
3622 ret
= find_first_extent_bit(&rc
->processed_blocks
,
3623 key
.objectid
, &start
, &end
,
3624 EXTENT_DIRTY
, NULL
);
3626 if (ret
== 0 && start
<= key
.objectid
) {
3627 btrfs_release_path(path
);
3628 rc
->search_start
= end
+ 1;
3630 rc
->search_start
= key
.objectid
+ key
.offset
;
3631 memcpy(extent_key
, &key
, sizeof(key
));
3635 btrfs_release_path(path
);
3639 static void set_reloc_control(struct reloc_control
*rc
)
3641 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3643 mutex_lock(&fs_info
->reloc_mutex
);
3644 fs_info
->reloc_ctl
= rc
;
3645 mutex_unlock(&fs_info
->reloc_mutex
);
3648 static void unset_reloc_control(struct reloc_control
*rc
)
3650 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3652 mutex_lock(&fs_info
->reloc_mutex
);
3653 fs_info
->reloc_ctl
= NULL
;
3654 mutex_unlock(&fs_info
->reloc_mutex
);
3657 static int check_extent_flags(u64 flags
)
3659 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3660 (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3662 if (!(flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3663 !(flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3665 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3666 (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
))
3671 static noinline_for_stack
3672 int prepare_to_relocate(struct reloc_control
*rc
)
3674 struct btrfs_trans_handle
*trans
;
3677 rc
->block_rsv
= btrfs_alloc_block_rsv(rc
->extent_root
,
3678 BTRFS_BLOCK_RSV_TEMP
);
3683 * reserve some space for creating reloc trees.
3684 * btrfs_init_reloc_root will use them when there
3685 * is no reservation in transaction handle.
3687 ret
= btrfs_block_rsv_add(rc
->extent_root
, rc
->block_rsv
,
3688 rc
->extent_root
->nodesize
* 256);
3692 memset(&rc
->cluster
, 0, sizeof(rc
->cluster
));
3693 rc
->search_start
= rc
->block_group
->key
.objectid
;
3694 rc
->extents_found
= 0;
3695 rc
->nodes_relocated
= 0;
3696 rc
->merging_rsv_size
= 0;
3698 rc
->create_reloc_tree
= 1;
3699 set_reloc_control(rc
);
3701 trans
= btrfs_join_transaction(rc
->extent_root
);
3702 BUG_ON(IS_ERR(trans
));
3703 btrfs_commit_transaction(trans
, rc
->extent_root
);
3707 static noinline_for_stack
int relocate_block_group(struct reloc_control
*rc
)
3709 struct rb_root blocks
= RB_ROOT
;
3710 struct btrfs_key key
;
3711 struct btrfs_trans_handle
*trans
= NULL
;
3712 struct btrfs_path
*path
;
3713 struct btrfs_extent_item
*ei
;
3721 path
= btrfs_alloc_path();
3726 ret
= prepare_to_relocate(rc
);
3734 trans
= btrfs_start_transaction(rc
->extent_root
, 0);
3735 BUG_ON(IS_ERR(trans
));
3737 if (update_backref_cache(trans
, &rc
->backref_cache
)) {
3738 btrfs_end_transaction(trans
, rc
->extent_root
);
3742 ret
= find_next_extent(trans
, rc
, path
, &key
);
3748 rc
->extents_found
++;
3750 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
3751 struct btrfs_extent_item
);
3752 item_size
= btrfs_item_size_nr(path
->nodes
[0], path
->slots
[0]);
3753 if (item_size
>= sizeof(*ei
)) {
3754 flags
= btrfs_extent_flags(path
->nodes
[0], ei
);
3755 ret
= check_extent_flags(flags
);
3759 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3761 int path_change
= 0;
3764 sizeof(struct btrfs_extent_item_v0
));
3765 ret
= get_ref_objectid_v0(rc
, path
, &key
, &ref_owner
,
3767 if (ref_owner
< BTRFS_FIRST_FREE_OBJECTID
)
3768 flags
= BTRFS_EXTENT_FLAG_TREE_BLOCK
;
3770 flags
= BTRFS_EXTENT_FLAG_DATA
;
3773 btrfs_release_path(path
);
3775 path
->search_commit_root
= 1;
3776 path
->skip_locking
= 1;
3777 ret
= btrfs_search_slot(NULL
, rc
->extent_root
,
3790 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
3791 ret
= add_tree_block(rc
, &key
, path
, &blocks
);
3792 } else if (rc
->stage
== UPDATE_DATA_PTRS
&&
3793 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
3794 ret
= add_data_references(rc
, &key
, path
, &blocks
);
3796 btrfs_release_path(path
);
3804 if (!RB_EMPTY_ROOT(&blocks
)) {
3805 ret
= relocate_tree_blocks(trans
, rc
, &blocks
);
3807 if (ret
!= -EAGAIN
) {
3811 rc
->extents_found
--;
3812 rc
->search_start
= key
.objectid
;
3816 ret
= btrfs_block_rsv_check(rc
->extent_root
, rc
->block_rsv
, 5);
3818 if (ret
!= -ENOSPC
) {
3823 rc
->commit_transaction
= 1;
3826 if (rc
->commit_transaction
) {
3827 rc
->commit_transaction
= 0;
3828 ret
= btrfs_commit_transaction(trans
, rc
->extent_root
);
3831 nr
= trans
->blocks_used
;
3832 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
3833 btrfs_btree_balance_dirty(rc
->extent_root
, nr
);
3837 if (rc
->stage
== MOVE_DATA_EXTENTS
&&
3838 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
3839 rc
->found_file_extent
= 1;
3840 ret
= relocate_data_extent(rc
->data_inode
,
3841 &key
, &rc
->cluster
);
3848 if (trans
&& progress
&& err
== -ENOSPC
) {
3849 ret
= btrfs_force_chunk_alloc(trans
, rc
->extent_root
,
3850 rc
->block_group
->flags
);
3858 btrfs_release_path(path
);
3859 clear_extent_bits(&rc
->processed_blocks
, 0, (u64
)-1, EXTENT_DIRTY
,
3863 nr
= trans
->blocks_used
;
3864 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
3865 btrfs_btree_balance_dirty(rc
->extent_root
, nr
);
3869 ret
= relocate_file_extent_cluster(rc
->data_inode
,
3875 rc
->create_reloc_tree
= 0;
3876 set_reloc_control(rc
);
3878 backref_cache_cleanup(&rc
->backref_cache
);
3879 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
3881 err
= prepare_to_merge(rc
, err
);
3883 merge_reloc_roots(rc
);
3885 rc
->merge_reloc_tree
= 0;
3886 unset_reloc_control(rc
);
3887 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
3889 /* get rid of pinned extents */
3890 trans
= btrfs_join_transaction(rc
->extent_root
);
3892 err
= PTR_ERR(trans
);
3894 btrfs_commit_transaction(trans
, rc
->extent_root
);
3896 btrfs_free_block_rsv(rc
->extent_root
, rc
->block_rsv
);
3897 btrfs_free_path(path
);
3901 static int __insert_orphan_inode(struct btrfs_trans_handle
*trans
,
3902 struct btrfs_root
*root
, u64 objectid
)
3904 struct btrfs_path
*path
;
3905 struct btrfs_inode_item
*item
;
3906 struct extent_buffer
*leaf
;
3909 path
= btrfs_alloc_path();
3913 ret
= btrfs_insert_empty_inode(trans
, root
, path
, objectid
);
3917 leaf
= path
->nodes
[0];
3918 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_inode_item
);
3919 memset_extent_buffer(leaf
, 0, (unsigned long)item
, sizeof(*item
));
3920 btrfs_set_inode_generation(leaf
, item
, 1);
3921 btrfs_set_inode_size(leaf
, item
, 0);
3922 btrfs_set_inode_mode(leaf
, item
, S_IFREG
| 0600);
3923 btrfs_set_inode_flags(leaf
, item
, BTRFS_INODE_NOCOMPRESS
|
3924 BTRFS_INODE_PREALLOC
);
3925 btrfs_mark_buffer_dirty(leaf
);
3926 btrfs_release_path(path
);
3928 btrfs_free_path(path
);
3933 * helper to create inode for data relocation.
3934 * the inode is in data relocation tree and its link count is 0
3936 static noinline_for_stack
3937 struct inode
*create_reloc_inode(struct btrfs_fs_info
*fs_info
,
3938 struct btrfs_block_group_cache
*group
)
3940 struct inode
*inode
= NULL
;
3941 struct btrfs_trans_handle
*trans
;
3942 struct btrfs_root
*root
;
3943 struct btrfs_key key
;
3945 u64 objectid
= BTRFS_FIRST_FREE_OBJECTID
;
3948 root
= read_fs_root(fs_info
, BTRFS_DATA_RELOC_TREE_OBJECTID
);
3950 return ERR_CAST(root
);
3952 trans
= btrfs_start_transaction(root
, 6);
3954 return ERR_CAST(trans
);
3956 err
= btrfs_find_free_objectid(root
, &objectid
);
3960 err
= __insert_orphan_inode(trans
, root
, objectid
);
3963 key
.objectid
= objectid
;
3964 key
.type
= BTRFS_INODE_ITEM_KEY
;
3966 inode
= btrfs_iget(root
->fs_info
->sb
, &key
, root
, NULL
);
3967 BUG_ON(IS_ERR(inode
) || is_bad_inode(inode
));
3968 BTRFS_I(inode
)->index_cnt
= group
->key
.objectid
;
3970 err
= btrfs_orphan_add(trans
, inode
);
3972 nr
= trans
->blocks_used
;
3973 btrfs_end_transaction(trans
, root
);
3974 btrfs_btree_balance_dirty(root
, nr
);
3978 inode
= ERR_PTR(err
);
3983 static struct reloc_control
*alloc_reloc_control(void)
3985 struct reloc_control
*rc
;
3987 rc
= kzalloc(sizeof(*rc
), GFP_NOFS
);
3991 INIT_LIST_HEAD(&rc
->reloc_roots
);
3992 backref_cache_init(&rc
->backref_cache
);
3993 mapping_tree_init(&rc
->reloc_root_tree
);
3994 extent_io_tree_init(&rc
->processed_blocks
, NULL
);
3999 * function to relocate all extents in a block group.
4001 int btrfs_relocate_block_group(struct btrfs_root
*extent_root
, u64 group_start
)
4003 struct btrfs_fs_info
*fs_info
= extent_root
->fs_info
;
4004 struct reloc_control
*rc
;
4005 struct inode
*inode
;
4006 struct btrfs_path
*path
;
4011 rc
= alloc_reloc_control();
4015 rc
->extent_root
= extent_root
;
4017 rc
->block_group
= btrfs_lookup_block_group(fs_info
, group_start
);
4018 BUG_ON(!rc
->block_group
);
4020 if (!rc
->block_group
->ro
) {
4021 ret
= btrfs_set_block_group_ro(extent_root
, rc
->block_group
);
4029 path
= btrfs_alloc_path();
4035 inode
= lookup_free_space_inode(fs_info
->tree_root
, rc
->block_group
,
4037 btrfs_free_path(path
);
4040 ret
= delete_block_group_cache(fs_info
, inode
, 0);
4042 ret
= PTR_ERR(inode
);
4044 if (ret
&& ret
!= -ENOENT
) {
4049 rc
->data_inode
= create_reloc_inode(fs_info
, rc
->block_group
);
4050 if (IS_ERR(rc
->data_inode
)) {
4051 err
= PTR_ERR(rc
->data_inode
);
4052 rc
->data_inode
= NULL
;
4056 printk(KERN_INFO
"btrfs: relocating block group %llu flags %llu\n",
4057 (unsigned long long)rc
->block_group
->key
.objectid
,
4058 (unsigned long long)rc
->block_group
->flags
);
4060 btrfs_start_delalloc_inodes(fs_info
->tree_root
, 0);
4061 btrfs_wait_ordered_extents(fs_info
->tree_root
, 0);
4064 mutex_lock(&fs_info
->cleaner_mutex
);
4066 btrfs_clean_old_snapshots(fs_info
->tree_root
);
4067 ret
= relocate_block_group(rc
);
4069 mutex_unlock(&fs_info
->cleaner_mutex
);
4075 if (rc
->extents_found
== 0)
4078 printk(KERN_INFO
"btrfs: found %llu extents\n",
4079 (unsigned long long)rc
->extents_found
);
4081 if (rc
->stage
== MOVE_DATA_EXTENTS
&& rc
->found_file_extent
) {
4082 btrfs_wait_ordered_range(rc
->data_inode
, 0, (u64
)-1);
4083 invalidate_mapping_pages(rc
->data_inode
->i_mapping
,
4085 rc
->stage
= UPDATE_DATA_PTRS
;
4089 filemap_write_and_wait_range(fs_info
->btree_inode
->i_mapping
,
4090 rc
->block_group
->key
.objectid
,
4091 rc
->block_group
->key
.objectid
+
4092 rc
->block_group
->key
.offset
- 1);
4094 WARN_ON(rc
->block_group
->pinned
> 0);
4095 WARN_ON(rc
->block_group
->reserved
> 0);
4096 WARN_ON(btrfs_block_group_used(&rc
->block_group
->item
) > 0);
4099 btrfs_set_block_group_rw(extent_root
, rc
->block_group
);
4100 iput(rc
->data_inode
);
4101 btrfs_put_block_group(rc
->block_group
);
4106 static noinline_for_stack
int mark_garbage_root(struct btrfs_root
*root
)
4108 struct btrfs_trans_handle
*trans
;
4111 trans
= btrfs_start_transaction(root
->fs_info
->tree_root
, 0);
4113 return PTR_ERR(trans
);
4115 memset(&root
->root_item
.drop_progress
, 0,
4116 sizeof(root
->root_item
.drop_progress
));
4117 root
->root_item
.drop_level
= 0;
4118 btrfs_set_root_refs(&root
->root_item
, 0);
4119 ret
= btrfs_update_root(trans
, root
->fs_info
->tree_root
,
4120 &root
->root_key
, &root
->root_item
);
4122 err
= btrfs_end_transaction(trans
, root
->fs_info
->tree_root
);
4129 * recover relocation interrupted by system crash.
4131 * this function resumes merging reloc trees with corresponding fs trees.
4132 * this is important for keeping the sharing of tree blocks
4134 int btrfs_recover_relocation(struct btrfs_root
*root
)
4136 LIST_HEAD(reloc_roots
);
4137 struct btrfs_key key
;
4138 struct btrfs_root
*fs_root
;
4139 struct btrfs_root
*reloc_root
;
4140 struct btrfs_path
*path
;
4141 struct extent_buffer
*leaf
;
4142 struct reloc_control
*rc
= NULL
;
4143 struct btrfs_trans_handle
*trans
;
4147 path
= btrfs_alloc_path();
4152 key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
4153 key
.type
= BTRFS_ROOT_ITEM_KEY
;
4154 key
.offset
= (u64
)-1;
4157 ret
= btrfs_search_slot(NULL
, root
->fs_info
->tree_root
, &key
,
4164 if (path
->slots
[0] == 0)
4168 leaf
= path
->nodes
[0];
4169 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
4170 btrfs_release_path(path
);
4172 if (key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
||
4173 key
.type
!= BTRFS_ROOT_ITEM_KEY
)
4176 reloc_root
= btrfs_read_fs_root_no_radix(root
, &key
);
4177 if (IS_ERR(reloc_root
)) {
4178 err
= PTR_ERR(reloc_root
);
4182 list_add(&reloc_root
->root_list
, &reloc_roots
);
4184 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
4185 fs_root
= read_fs_root(root
->fs_info
,
4186 reloc_root
->root_key
.offset
);
4187 if (IS_ERR(fs_root
)) {
4188 ret
= PTR_ERR(fs_root
);
4189 if (ret
!= -ENOENT
) {
4193 ret
= mark_garbage_root(reloc_root
);
4201 if (key
.offset
== 0)
4206 btrfs_release_path(path
);
4208 if (list_empty(&reloc_roots
))
4211 rc
= alloc_reloc_control();
4217 rc
->extent_root
= root
->fs_info
->extent_root
;
4219 set_reloc_control(rc
);
4221 trans
= btrfs_join_transaction(rc
->extent_root
);
4222 if (IS_ERR(trans
)) {
4223 unset_reloc_control(rc
);
4224 err
= PTR_ERR(trans
);
4228 rc
->merge_reloc_tree
= 1;
4230 while (!list_empty(&reloc_roots
)) {
4231 reloc_root
= list_entry(reloc_roots
.next
,
4232 struct btrfs_root
, root_list
);
4233 list_del(&reloc_root
->root_list
);
4235 if (btrfs_root_refs(&reloc_root
->root_item
) == 0) {
4236 list_add_tail(&reloc_root
->root_list
,
4241 fs_root
= read_fs_root(root
->fs_info
,
4242 reloc_root
->root_key
.offset
);
4243 if (IS_ERR(fs_root
)) {
4244 err
= PTR_ERR(fs_root
);
4248 err
= __add_reloc_root(reloc_root
);
4249 BUG_ON(err
< 0); /* -ENOMEM or logic error */
4250 fs_root
->reloc_root
= reloc_root
;
4253 err
= btrfs_commit_transaction(trans
, rc
->extent_root
);
4257 merge_reloc_roots(rc
);
4259 unset_reloc_control(rc
);
4261 trans
= btrfs_join_transaction(rc
->extent_root
);
4263 err
= PTR_ERR(trans
);
4265 err
= btrfs_commit_transaction(trans
, rc
->extent_root
);
4269 while (!list_empty(&reloc_roots
)) {
4270 reloc_root
= list_entry(reloc_roots
.next
,
4271 struct btrfs_root
, root_list
);
4272 list_del(&reloc_root
->root_list
);
4273 free_extent_buffer(reloc_root
->node
);
4274 free_extent_buffer(reloc_root
->commit_root
);
4277 btrfs_free_path(path
);
4280 /* cleanup orphan inode in data relocation tree */
4281 fs_root
= read_fs_root(root
->fs_info
,
4282 BTRFS_DATA_RELOC_TREE_OBJECTID
);
4283 if (IS_ERR(fs_root
))
4284 err
= PTR_ERR(fs_root
);
4286 err
= btrfs_orphan_cleanup(fs_root
);
4292 * helper to add ordered checksum for data relocation.
4294 * cloning checksum properly handles the nodatasum extents.
4295 * it also saves CPU time to re-calculate the checksum.
4297 int btrfs_reloc_clone_csums(struct inode
*inode
, u64 file_pos
, u64 len
)
4299 struct btrfs_ordered_sum
*sums
;
4300 struct btrfs_sector_sum
*sector_sum
;
4301 struct btrfs_ordered_extent
*ordered
;
4302 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
4308 ordered
= btrfs_lookup_ordered_extent(inode
, file_pos
);
4309 BUG_ON(ordered
->file_offset
!= file_pos
|| ordered
->len
!= len
);
4311 disk_bytenr
= file_pos
+ BTRFS_I(inode
)->index_cnt
;
4312 ret
= btrfs_lookup_csums_range(root
->fs_info
->csum_root
, disk_bytenr
,
4313 disk_bytenr
+ len
- 1, &list
, 0);
4317 while (!list_empty(&list
)) {
4318 sums
= list_entry(list
.next
, struct btrfs_ordered_sum
, list
);
4319 list_del_init(&sums
->list
);
4321 sector_sum
= sums
->sums
;
4322 sums
->bytenr
= ordered
->start
;
4325 while (offset
< sums
->len
) {
4326 sector_sum
->bytenr
+= ordered
->start
- disk_bytenr
;
4328 offset
+= root
->sectorsize
;
4331 btrfs_add_ordered_sum(inode
, ordered
, sums
);
4334 btrfs_put_ordered_extent(ordered
);
4338 void btrfs_reloc_cow_block(struct btrfs_trans_handle
*trans
,
4339 struct btrfs_root
*root
, struct extent_buffer
*buf
,
4340 struct extent_buffer
*cow
)
4342 struct reloc_control
*rc
;
4343 struct backref_node
*node
;
4348 rc
= root
->fs_info
->reloc_ctl
;
4352 BUG_ON(rc
->stage
== UPDATE_DATA_PTRS
&&
4353 root
->root_key
.objectid
== BTRFS_DATA_RELOC_TREE_OBJECTID
);
4355 level
= btrfs_header_level(buf
);
4356 if (btrfs_header_generation(buf
) <=
4357 btrfs_root_last_snapshot(&root
->root_item
))
4360 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
&&
4361 rc
->create_reloc_tree
) {
4362 WARN_ON(!first_cow
&& level
== 0);
4364 node
= rc
->backref_cache
.path
[level
];
4365 BUG_ON(node
->bytenr
!= buf
->start
&&
4366 node
->new_bytenr
!= buf
->start
);
4368 drop_node_buffer(node
);
4369 extent_buffer_get(cow
);
4371 node
->new_bytenr
= cow
->start
;
4373 if (!node
->pending
) {
4374 list_move_tail(&node
->list
,
4375 &rc
->backref_cache
.pending
[level
]);
4380 __mark_block_processed(rc
, node
);
4382 if (first_cow
&& level
> 0)
4383 rc
->nodes_relocated
+= buf
->len
;
4386 if (level
== 0 && first_cow
&& rc
->stage
== UPDATE_DATA_PTRS
) {
4387 ret
= replace_file_extents(trans
, rc
, root
, cow
);
4393 * called before creating snapshot. it calculates metadata reservation
4394 * requried for relocating tree blocks in the snapshot
4396 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle
*trans
,
4397 struct btrfs_pending_snapshot
*pending
,
4398 u64
*bytes_to_reserve
)
4400 struct btrfs_root
*root
;
4401 struct reloc_control
*rc
;
4403 root
= pending
->root
;
4404 if (!root
->reloc_root
)
4407 rc
= root
->fs_info
->reloc_ctl
;
4408 if (!rc
->merge_reloc_tree
)
4411 root
= root
->reloc_root
;
4412 BUG_ON(btrfs_root_refs(&root
->root_item
) == 0);
4414 * relocation is in the stage of merging trees. the space
4415 * used by merging a reloc tree is twice the size of
4416 * relocated tree nodes in the worst case. half for cowing
4417 * the reloc tree, half for cowing the fs tree. the space
4418 * used by cowing the reloc tree will be freed after the
4419 * tree is dropped. if we create snapshot, cowing the fs
4420 * tree may use more space than it frees. so we need
4421 * reserve extra space.
4423 *bytes_to_reserve
+= rc
->nodes_relocated
;
4427 * called after snapshot is created. migrate block reservation
4428 * and create reloc root for the newly created snapshot
4430 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle
*trans
,
4431 struct btrfs_pending_snapshot
*pending
)
4433 struct btrfs_root
*root
= pending
->root
;
4434 struct btrfs_root
*reloc_root
;
4435 struct btrfs_root
*new_root
;
4436 struct reloc_control
*rc
;
4439 if (!root
->reloc_root
)
4442 rc
= root
->fs_info
->reloc_ctl
;
4443 rc
->merging_rsv_size
+= rc
->nodes_relocated
;
4445 if (rc
->merge_reloc_tree
) {
4446 ret
= btrfs_block_rsv_migrate(&pending
->block_rsv
,
4448 rc
->nodes_relocated
);
4453 new_root
= pending
->snap
;
4454 reloc_root
= create_reloc_root(trans
, root
->reloc_root
,
4455 new_root
->root_key
.objectid
);
4456 if (IS_ERR(reloc_root
))
4457 return PTR_ERR(reloc_root
);
4459 ret
= __add_reloc_root(reloc_root
);
4461 new_root
->reloc_root
= reloc_root
;
4463 if (rc
->create_reloc_tree
)
4464 ret
= clone_backref_node(trans
, rc
, root
, reloc_root
);