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
)
330 * walk up backref nodes until reach node presents tree root
332 static struct backref_node
*walk_up_backref(struct backref_node
*node
,
333 struct backref_edge
*edges
[],
336 struct backref_edge
*edge
;
339 while (!list_empty(&node
->upper
)) {
340 edge
= list_entry(node
->upper
.next
,
341 struct backref_edge
, list
[LOWER
]);
343 node
= edge
->node
[UPPER
];
345 BUG_ON(node
->detached
);
351 * walk down backref nodes to find start of next reference path
353 static struct backref_node
*walk_down_backref(struct backref_edge
*edges
[],
356 struct backref_edge
*edge
;
357 struct backref_node
*lower
;
361 edge
= edges
[idx
- 1];
362 lower
= edge
->node
[LOWER
];
363 if (list_is_last(&edge
->list
[LOWER
], &lower
->upper
)) {
367 edge
= list_entry(edge
->list
[LOWER
].next
,
368 struct backref_edge
, list
[LOWER
]);
369 edges
[idx
- 1] = edge
;
371 return edge
->node
[UPPER
];
377 static void unlock_node_buffer(struct backref_node
*node
)
380 btrfs_tree_unlock(node
->eb
);
385 static void drop_node_buffer(struct backref_node
*node
)
388 unlock_node_buffer(node
);
389 free_extent_buffer(node
->eb
);
394 static void drop_backref_node(struct backref_cache
*tree
,
395 struct backref_node
*node
)
397 BUG_ON(!list_empty(&node
->upper
));
399 drop_node_buffer(node
);
400 list_del(&node
->list
);
401 list_del(&node
->lower
);
402 if (!RB_EMPTY_NODE(&node
->rb_node
))
403 rb_erase(&node
->rb_node
, &tree
->rb_root
);
404 free_backref_node(tree
, node
);
408 * remove a backref node from the backref cache
410 static void remove_backref_node(struct backref_cache
*cache
,
411 struct backref_node
*node
)
413 struct backref_node
*upper
;
414 struct backref_edge
*edge
;
419 BUG_ON(!node
->lowest
&& !node
->detached
);
420 while (!list_empty(&node
->upper
)) {
421 edge
= list_entry(node
->upper
.next
, struct backref_edge
,
423 upper
= edge
->node
[UPPER
];
424 list_del(&edge
->list
[LOWER
]);
425 list_del(&edge
->list
[UPPER
]);
426 free_backref_edge(cache
, edge
);
428 if (RB_EMPTY_NODE(&upper
->rb_node
)) {
429 BUG_ON(!list_empty(&node
->upper
));
430 drop_backref_node(cache
, node
);
436 * add the node to leaf node list if no other
437 * child block cached.
439 if (list_empty(&upper
->lower
)) {
440 list_add_tail(&upper
->lower
, &cache
->leaves
);
445 drop_backref_node(cache
, node
);
448 static void update_backref_node(struct backref_cache
*cache
,
449 struct backref_node
*node
, u64 bytenr
)
451 struct rb_node
*rb_node
;
452 rb_erase(&node
->rb_node
, &cache
->rb_root
);
453 node
->bytenr
= bytenr
;
454 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
, &node
->rb_node
);
459 * update backref cache after a transaction commit
461 static int update_backref_cache(struct btrfs_trans_handle
*trans
,
462 struct backref_cache
*cache
)
464 struct backref_node
*node
;
467 if (cache
->last_trans
== 0) {
468 cache
->last_trans
= trans
->transid
;
472 if (cache
->last_trans
== trans
->transid
)
476 * detached nodes are used to avoid unnecessary backref
477 * lookup. transaction commit changes the extent tree.
478 * so the detached nodes are no longer useful.
480 while (!list_empty(&cache
->detached
)) {
481 node
= list_entry(cache
->detached
.next
,
482 struct backref_node
, list
);
483 remove_backref_node(cache
, node
);
486 while (!list_empty(&cache
->changed
)) {
487 node
= list_entry(cache
->changed
.next
,
488 struct backref_node
, list
);
489 list_del_init(&node
->list
);
490 BUG_ON(node
->pending
);
491 update_backref_node(cache
, node
, node
->new_bytenr
);
495 * some nodes can be left in the pending list if there were
496 * errors during processing the pending nodes.
498 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
499 list_for_each_entry(node
, &cache
->pending
[level
], list
) {
500 BUG_ON(!node
->pending
);
501 if (node
->bytenr
== node
->new_bytenr
)
503 update_backref_node(cache
, node
, node
->new_bytenr
);
507 cache
->last_trans
= 0;
512 static int should_ignore_root(struct btrfs_root
*root
)
514 struct btrfs_root
*reloc_root
;
519 reloc_root
= root
->reloc_root
;
523 if (btrfs_root_last_snapshot(&reloc_root
->root_item
) ==
524 root
->fs_info
->running_transaction
->transid
- 1)
527 * if there is reloc tree and it was created in previous
528 * transaction backref lookup can find the reloc tree,
529 * so backref node for the fs tree root is useless for
535 * find reloc tree by address of tree root
537 static struct btrfs_root
*find_reloc_root(struct reloc_control
*rc
,
540 struct rb_node
*rb_node
;
541 struct mapping_node
*node
;
542 struct btrfs_root
*root
= NULL
;
544 spin_lock(&rc
->reloc_root_tree
.lock
);
545 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
, bytenr
);
547 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
548 root
= (struct btrfs_root
*)node
->data
;
550 spin_unlock(&rc
->reloc_root_tree
.lock
);
554 static int is_cowonly_root(u64 root_objectid
)
556 if (root_objectid
== BTRFS_ROOT_TREE_OBJECTID
||
557 root_objectid
== BTRFS_EXTENT_TREE_OBJECTID
||
558 root_objectid
== BTRFS_CHUNK_TREE_OBJECTID
||
559 root_objectid
== BTRFS_DEV_TREE_OBJECTID
||
560 root_objectid
== BTRFS_TREE_LOG_OBJECTID
||
561 root_objectid
== BTRFS_CSUM_TREE_OBJECTID
)
566 static struct btrfs_root
*read_fs_root(struct btrfs_fs_info
*fs_info
,
569 struct btrfs_key key
;
571 key
.objectid
= root_objectid
;
572 key
.type
= BTRFS_ROOT_ITEM_KEY
;
573 if (is_cowonly_root(root_objectid
))
576 key
.offset
= (u64
)-1;
578 return btrfs_read_fs_root_no_name(fs_info
, &key
);
581 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
582 static noinline_for_stack
583 struct btrfs_root
*find_tree_root(struct reloc_control
*rc
,
584 struct extent_buffer
*leaf
,
585 struct btrfs_extent_ref_v0
*ref0
)
587 struct btrfs_root
*root
;
588 u64 root_objectid
= btrfs_ref_root_v0(leaf
, ref0
);
589 u64 generation
= btrfs_ref_generation_v0(leaf
, ref0
);
591 BUG_ON(root_objectid
== BTRFS_TREE_RELOC_OBJECTID
);
593 root
= read_fs_root(rc
->extent_root
->fs_info
, root_objectid
);
594 BUG_ON(IS_ERR(root
));
596 if (root
->ref_cows
&&
597 generation
!= btrfs_root_generation(&root
->root_item
))
604 static noinline_for_stack
605 int find_inline_backref(struct extent_buffer
*leaf
, int slot
,
606 unsigned long *ptr
, unsigned long *end
)
608 struct btrfs_extent_item
*ei
;
609 struct btrfs_tree_block_info
*bi
;
612 item_size
= btrfs_item_size_nr(leaf
, slot
);
613 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
614 if (item_size
< sizeof(*ei
)) {
615 WARN_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
619 ei
= btrfs_item_ptr(leaf
, slot
, struct btrfs_extent_item
);
620 WARN_ON(!(btrfs_extent_flags(leaf
, ei
) &
621 BTRFS_EXTENT_FLAG_TREE_BLOCK
));
623 if (item_size
<= sizeof(*ei
) + sizeof(*bi
)) {
624 WARN_ON(item_size
< sizeof(*ei
) + sizeof(*bi
));
628 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
629 *ptr
= (unsigned long)(bi
+ 1);
630 *end
= (unsigned long)ei
+ item_size
;
635 * build backref tree for a given tree block. root of the backref tree
636 * corresponds the tree block, leaves of the backref tree correspond
637 * roots of b-trees that reference the tree block.
639 * the basic idea of this function is check backrefs of a given block
640 * to find upper level blocks that refernece the block, and then check
641 * bakcrefs of these upper level blocks recursively. the recursion stop
642 * when tree root is reached or backrefs for the block is cached.
644 * NOTE: if we find backrefs for a block are cached, we know backrefs
645 * for all upper level blocks that directly/indirectly reference the
646 * block are also cached.
648 static noinline_for_stack
649 struct backref_node
*build_backref_tree(struct reloc_control
*rc
,
650 struct btrfs_key
*node_key
,
651 int level
, u64 bytenr
)
653 struct backref_cache
*cache
= &rc
->backref_cache
;
654 struct btrfs_path
*path1
;
655 struct btrfs_path
*path2
;
656 struct extent_buffer
*eb
;
657 struct btrfs_root
*root
;
658 struct backref_node
*cur
;
659 struct backref_node
*upper
;
660 struct backref_node
*lower
;
661 struct backref_node
*node
= NULL
;
662 struct backref_node
*exist
= NULL
;
663 struct backref_edge
*edge
;
664 struct rb_node
*rb_node
;
665 struct btrfs_key key
;
674 path1
= btrfs_alloc_path();
675 path2
= btrfs_alloc_path();
676 if (!path1
|| !path2
) {
683 node
= alloc_backref_node(cache
);
689 node
->bytenr
= bytenr
;
696 key
.objectid
= cur
->bytenr
;
697 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
698 key
.offset
= (u64
)-1;
700 path1
->search_commit_root
= 1;
701 path1
->skip_locking
= 1;
702 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path1
,
708 BUG_ON(!ret
|| !path1
->slots
[0]);
712 WARN_ON(cur
->checked
);
713 if (!list_empty(&cur
->upper
)) {
715 * the backref was added previously when processing
716 * backref of type BTRFS_TREE_BLOCK_REF_KEY
718 BUG_ON(!list_is_singular(&cur
->upper
));
719 edge
= list_entry(cur
->upper
.next
, struct backref_edge
,
721 BUG_ON(!list_empty(&edge
->list
[UPPER
]));
722 exist
= edge
->node
[UPPER
];
724 * add the upper level block to pending list if we need
728 list_add_tail(&edge
->list
[UPPER
], &list
);
735 eb
= path1
->nodes
[0];
738 if (path1
->slots
[0] >= btrfs_header_nritems(eb
)) {
739 ret
= btrfs_next_leaf(rc
->extent_root
, path1
);
746 eb
= path1
->nodes
[0];
749 btrfs_item_key_to_cpu(eb
, &key
, path1
->slots
[0]);
750 if (key
.objectid
!= cur
->bytenr
) {
755 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
) {
756 ret
= find_inline_backref(eb
, path1
->slots
[0],
764 /* update key for inline back ref */
765 struct btrfs_extent_inline_ref
*iref
;
766 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
767 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
768 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
769 WARN_ON(key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
&&
770 key
.type
!= BTRFS_SHARED_BLOCK_REF_KEY
);
774 ((key
.type
== BTRFS_TREE_BLOCK_REF_KEY
&&
775 exist
->owner
== key
.offset
) ||
776 (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
&&
777 exist
->bytenr
== key
.offset
))) {
782 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
783 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
||
784 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
785 if (key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
786 struct btrfs_extent_ref_v0
*ref0
;
787 ref0
= btrfs_item_ptr(eb
, path1
->slots
[0],
788 struct btrfs_extent_ref_v0
);
789 if (key
.objectid
== key
.offset
) {
790 root
= find_tree_root(rc
, eb
, ref0
);
791 if (root
&& !should_ignore_root(root
))
794 list_add(&cur
->list
, &useless
);
797 if (is_cowonly_root(btrfs_ref_root_v0(eb
,
802 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
803 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
) {
805 if (key
.objectid
== key
.offset
) {
807 * only root blocks of reloc trees use
808 * backref of this type.
810 root
= find_reloc_root(rc
, cur
->bytenr
);
816 edge
= alloc_backref_edge(cache
);
821 rb_node
= tree_search(&cache
->rb_root
, key
.offset
);
823 upper
= alloc_backref_node(cache
);
825 free_backref_edge(cache
, edge
);
829 upper
->bytenr
= key
.offset
;
830 upper
->level
= cur
->level
+ 1;
832 * backrefs for the upper level block isn't
833 * cached, add the block to pending list
835 list_add_tail(&edge
->list
[UPPER
], &list
);
837 upper
= rb_entry(rb_node
, struct backref_node
,
839 BUG_ON(!upper
->checked
);
840 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
842 list_add_tail(&edge
->list
[LOWER
], &cur
->upper
);
843 edge
->node
[LOWER
] = cur
;
844 edge
->node
[UPPER
] = upper
;
847 } else if (key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
) {
851 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
852 root
= read_fs_root(rc
->extent_root
->fs_info
, key
.offset
);
861 if (btrfs_root_level(&root
->root_item
) == cur
->level
) {
863 BUG_ON(btrfs_root_bytenr(&root
->root_item
) !=
865 if (should_ignore_root(root
))
866 list_add(&cur
->list
, &useless
);
872 level
= cur
->level
+ 1;
875 * searching the tree to find upper level blocks
876 * reference the block.
878 path2
->search_commit_root
= 1;
879 path2
->skip_locking
= 1;
880 path2
->lowest_level
= level
;
881 ret
= btrfs_search_slot(NULL
, root
, node_key
, path2
, 0, 0);
882 path2
->lowest_level
= 0;
887 if (ret
> 0 && path2
->slots
[level
] > 0)
888 path2
->slots
[level
]--;
890 eb
= path2
->nodes
[level
];
891 WARN_ON(btrfs_node_blockptr(eb
, path2
->slots
[level
]) !=
895 for (; level
< BTRFS_MAX_LEVEL
; level
++) {
896 if (!path2
->nodes
[level
]) {
897 BUG_ON(btrfs_root_bytenr(&root
->root_item
) !=
899 if (should_ignore_root(root
))
900 list_add(&lower
->list
, &useless
);
906 edge
= alloc_backref_edge(cache
);
912 eb
= path2
->nodes
[level
];
913 rb_node
= tree_search(&cache
->rb_root
, eb
->start
);
915 upper
= alloc_backref_node(cache
);
917 free_backref_edge(cache
, edge
);
921 upper
->bytenr
= eb
->start
;
922 upper
->owner
= btrfs_header_owner(eb
);
923 upper
->level
= lower
->level
+ 1;
928 * if we know the block isn't shared
929 * we can void checking its backrefs.
931 if (btrfs_block_can_be_shared(root
, eb
))
937 * add the block to pending list if we
938 * need check its backrefs. only block
939 * at 'cur->level + 1' is added to the
940 * tail of pending list. this guarantees
941 * we check backrefs from lower level
942 * blocks to upper level blocks.
944 if (!upper
->checked
&&
945 level
== cur
->level
+ 1) {
946 list_add_tail(&edge
->list
[UPPER
],
949 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
951 upper
= rb_entry(rb_node
, struct backref_node
,
953 BUG_ON(!upper
->checked
);
954 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
956 upper
->owner
= btrfs_header_owner(eb
);
958 list_add_tail(&edge
->list
[LOWER
], &lower
->upper
);
959 edge
->node
[LOWER
] = lower
;
960 edge
->node
[UPPER
] = upper
;
967 btrfs_release_path(path2
);
970 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
980 btrfs_release_path(path1
);
985 /* the pending list isn't empty, take the first block to process */
986 if (!list_empty(&list
)) {
987 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
988 list_del_init(&edge
->list
[UPPER
]);
989 cur
= edge
->node
[UPPER
];
994 * everything goes well, connect backref nodes and insert backref nodes
997 BUG_ON(!node
->checked
);
998 cowonly
= node
->cowonly
;
1000 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
,
1003 list_add_tail(&node
->lower
, &cache
->leaves
);
1006 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
])
1007 list_add_tail(&edge
->list
[UPPER
], &list
);
1009 while (!list_empty(&list
)) {
1010 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1011 list_del_init(&edge
->list
[UPPER
]);
1012 upper
= edge
->node
[UPPER
];
1013 if (upper
->detached
) {
1014 list_del(&edge
->list
[LOWER
]);
1015 lower
= edge
->node
[LOWER
];
1016 free_backref_edge(cache
, edge
);
1017 if (list_empty(&lower
->upper
))
1018 list_add(&lower
->list
, &useless
);
1022 if (!RB_EMPTY_NODE(&upper
->rb_node
)) {
1023 if (upper
->lowest
) {
1024 list_del_init(&upper
->lower
);
1028 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1032 BUG_ON(!upper
->checked
);
1033 BUG_ON(cowonly
!= upper
->cowonly
);
1035 rb_node
= tree_insert(&cache
->rb_root
, upper
->bytenr
,
1040 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1042 list_for_each_entry(edge
, &upper
->upper
, list
[LOWER
])
1043 list_add_tail(&edge
->list
[UPPER
], &list
);
1046 * process useless backref nodes. backref nodes for tree leaves
1047 * are deleted from the cache. backref nodes for upper level
1048 * tree blocks are left in the cache to avoid unnecessary backref
1051 while (!list_empty(&useless
)) {
1052 upper
= list_entry(useless
.next
, struct backref_node
, list
);
1053 list_del_init(&upper
->list
);
1054 BUG_ON(!list_empty(&upper
->upper
));
1057 if (upper
->lowest
) {
1058 list_del_init(&upper
->lower
);
1061 while (!list_empty(&upper
->lower
)) {
1062 edge
= list_entry(upper
->lower
.next
,
1063 struct backref_edge
, list
[UPPER
]);
1064 list_del(&edge
->list
[UPPER
]);
1065 list_del(&edge
->list
[LOWER
]);
1066 lower
= edge
->node
[LOWER
];
1067 free_backref_edge(cache
, edge
);
1069 if (list_empty(&lower
->upper
))
1070 list_add(&lower
->list
, &useless
);
1072 __mark_block_processed(rc
, upper
);
1073 if (upper
->level
> 0) {
1074 list_add(&upper
->list
, &cache
->detached
);
1075 upper
->detached
= 1;
1077 rb_erase(&upper
->rb_node
, &cache
->rb_root
);
1078 free_backref_node(cache
, upper
);
1082 btrfs_free_path(path1
);
1083 btrfs_free_path(path2
);
1085 while (!list_empty(&useless
)) {
1086 lower
= list_entry(useless
.next
,
1087 struct backref_node
, upper
);
1088 list_del_init(&lower
->upper
);
1091 INIT_LIST_HEAD(&list
);
1093 if (RB_EMPTY_NODE(&upper
->rb_node
)) {
1094 list_splice_tail(&upper
->upper
, &list
);
1095 free_backref_node(cache
, upper
);
1098 if (list_empty(&list
))
1101 edge
= list_entry(list
.next
, struct backref_edge
,
1103 list_del(&edge
->list
[LOWER
]);
1104 upper
= edge
->node
[UPPER
];
1105 free_backref_edge(cache
, edge
);
1107 return ERR_PTR(err
);
1109 BUG_ON(node
&& node
->detached
);
1114 * helper to add backref node for the newly created snapshot.
1115 * the backref node is created by cloning backref node that
1116 * corresponds to root of source tree
1118 static int clone_backref_node(struct btrfs_trans_handle
*trans
,
1119 struct reloc_control
*rc
,
1120 struct btrfs_root
*src
,
1121 struct btrfs_root
*dest
)
1123 struct btrfs_root
*reloc_root
= src
->reloc_root
;
1124 struct backref_cache
*cache
= &rc
->backref_cache
;
1125 struct backref_node
*node
= NULL
;
1126 struct backref_node
*new_node
;
1127 struct backref_edge
*edge
;
1128 struct backref_edge
*new_edge
;
1129 struct rb_node
*rb_node
;
1131 if (cache
->last_trans
> 0)
1132 update_backref_cache(trans
, cache
);
1134 rb_node
= tree_search(&cache
->rb_root
, src
->commit_root
->start
);
1136 node
= rb_entry(rb_node
, struct backref_node
, rb_node
);
1140 BUG_ON(node
->new_bytenr
!= reloc_root
->node
->start
);
1144 rb_node
= tree_search(&cache
->rb_root
,
1145 reloc_root
->commit_root
->start
);
1147 node
= rb_entry(rb_node
, struct backref_node
,
1149 BUG_ON(node
->detached
);
1156 new_node
= alloc_backref_node(cache
);
1160 new_node
->bytenr
= dest
->node
->start
;
1161 new_node
->level
= node
->level
;
1162 new_node
->lowest
= node
->lowest
;
1163 new_node
->checked
= 1;
1164 new_node
->root
= dest
;
1166 if (!node
->lowest
) {
1167 list_for_each_entry(edge
, &node
->lower
, list
[UPPER
]) {
1168 new_edge
= alloc_backref_edge(cache
);
1172 new_edge
->node
[UPPER
] = new_node
;
1173 new_edge
->node
[LOWER
] = edge
->node
[LOWER
];
1174 list_add_tail(&new_edge
->list
[UPPER
],
1179 rb_node
= tree_insert(&cache
->rb_root
, new_node
->bytenr
,
1180 &new_node
->rb_node
);
1183 if (!new_node
->lowest
) {
1184 list_for_each_entry(new_edge
, &new_node
->lower
, list
[UPPER
]) {
1185 list_add_tail(&new_edge
->list
[LOWER
],
1186 &new_edge
->node
[LOWER
]->upper
);
1191 while (!list_empty(&new_node
->lower
)) {
1192 new_edge
= list_entry(new_node
->lower
.next
,
1193 struct backref_edge
, list
[UPPER
]);
1194 list_del(&new_edge
->list
[UPPER
]);
1195 free_backref_edge(cache
, new_edge
);
1197 free_backref_node(cache
, new_node
);
1202 * helper to add 'address of tree root -> reloc tree' mapping
1204 static int __add_reloc_root(struct btrfs_root
*root
)
1206 struct rb_node
*rb_node
;
1207 struct mapping_node
*node
;
1208 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1210 node
= kmalloc(sizeof(*node
), GFP_NOFS
);
1213 node
->bytenr
= root
->node
->start
;
1216 spin_lock(&rc
->reloc_root_tree
.lock
);
1217 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1218 node
->bytenr
, &node
->rb_node
);
1219 spin_unlock(&rc
->reloc_root_tree
.lock
);
1222 list_add_tail(&root
->root_list
, &rc
->reloc_roots
);
1227 * helper to update/delete the 'address of tree root -> reloc tree'
1230 static int __update_reloc_root(struct btrfs_root
*root
, int del
)
1232 struct rb_node
*rb_node
;
1233 struct mapping_node
*node
= NULL
;
1234 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1236 spin_lock(&rc
->reloc_root_tree
.lock
);
1237 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
,
1238 root
->commit_root
->start
);
1240 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
1241 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
1243 spin_unlock(&rc
->reloc_root_tree
.lock
);
1245 BUG_ON((struct btrfs_root
*)node
->data
!= root
);
1248 spin_lock(&rc
->reloc_root_tree
.lock
);
1249 node
->bytenr
= root
->node
->start
;
1250 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1251 node
->bytenr
, &node
->rb_node
);
1252 spin_unlock(&rc
->reloc_root_tree
.lock
);
1255 list_del_init(&root
->root_list
);
1261 static struct btrfs_root
*create_reloc_root(struct btrfs_trans_handle
*trans
,
1262 struct btrfs_root
*root
, u64 objectid
)
1264 struct btrfs_root
*reloc_root
;
1265 struct extent_buffer
*eb
;
1266 struct btrfs_root_item
*root_item
;
1267 struct btrfs_key root_key
;
1270 root_item
= kmalloc(sizeof(*root_item
), GFP_NOFS
);
1273 root_key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
1274 root_key
.type
= BTRFS_ROOT_ITEM_KEY
;
1275 root_key
.offset
= objectid
;
1277 if (root
->root_key
.objectid
== objectid
) {
1278 /* called by btrfs_init_reloc_root */
1279 ret
= btrfs_copy_root(trans
, root
, root
->commit_root
, &eb
,
1280 BTRFS_TREE_RELOC_OBJECTID
);
1283 btrfs_set_root_last_snapshot(&root
->root_item
,
1284 trans
->transid
- 1);
1287 * called by btrfs_reloc_post_snapshot_hook.
1288 * the source tree is a reloc tree, all tree blocks
1289 * modified after it was created have RELOC flag
1290 * set in their headers. so it's OK to not update
1291 * the 'last_snapshot'.
1293 ret
= btrfs_copy_root(trans
, root
, root
->node
, &eb
,
1294 BTRFS_TREE_RELOC_OBJECTID
);
1298 memcpy(root_item
, &root
->root_item
, sizeof(*root_item
));
1299 btrfs_set_root_bytenr(root_item
, eb
->start
);
1300 btrfs_set_root_level(root_item
, btrfs_header_level(eb
));
1301 btrfs_set_root_generation(root_item
, trans
->transid
);
1303 if (root
->root_key
.objectid
== objectid
) {
1304 btrfs_set_root_refs(root_item
, 0);
1305 memset(&root_item
->drop_progress
, 0,
1306 sizeof(struct btrfs_disk_key
));
1307 root_item
->drop_level
= 0;
1310 btrfs_tree_unlock(eb
);
1311 free_extent_buffer(eb
);
1313 ret
= btrfs_insert_root(trans
, root
->fs_info
->tree_root
,
1314 &root_key
, root_item
);
1318 reloc_root
= btrfs_read_fs_root_no_radix(root
->fs_info
->tree_root
,
1320 BUG_ON(IS_ERR(reloc_root
));
1321 reloc_root
->last_trans
= trans
->transid
;
1326 * create reloc tree for a given fs tree. reloc tree is just a
1327 * snapshot of the fs tree with special root objectid.
1329 int btrfs_init_reloc_root(struct btrfs_trans_handle
*trans
,
1330 struct btrfs_root
*root
)
1332 struct btrfs_root
*reloc_root
;
1333 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1336 if (root
->reloc_root
) {
1337 reloc_root
= root
->reloc_root
;
1338 reloc_root
->last_trans
= trans
->transid
;
1342 if (!rc
|| !rc
->create_reloc_tree
||
1343 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1346 if (!trans
->block_rsv
) {
1347 trans
->block_rsv
= rc
->block_rsv
;
1350 reloc_root
= create_reloc_root(trans
, root
, root
->root_key
.objectid
);
1352 trans
->block_rsv
= NULL
;
1354 __add_reloc_root(reloc_root
);
1355 root
->reloc_root
= reloc_root
;
1360 * update root item of reloc tree
1362 int btrfs_update_reloc_root(struct btrfs_trans_handle
*trans
,
1363 struct btrfs_root
*root
)
1365 struct btrfs_root
*reloc_root
;
1366 struct btrfs_root_item
*root_item
;
1370 if (!root
->reloc_root
)
1373 reloc_root
= root
->reloc_root
;
1374 root_item
= &reloc_root
->root_item
;
1376 if (root
->fs_info
->reloc_ctl
->merge_reloc_tree
&&
1377 btrfs_root_refs(root_item
) == 0) {
1378 root
->reloc_root
= NULL
;
1382 __update_reloc_root(reloc_root
, del
);
1384 if (reloc_root
->commit_root
!= reloc_root
->node
) {
1385 btrfs_set_root_node(root_item
, reloc_root
->node
);
1386 free_extent_buffer(reloc_root
->commit_root
);
1387 reloc_root
->commit_root
= btrfs_root_node(reloc_root
);
1390 ret
= btrfs_update_root(trans
, root
->fs_info
->tree_root
,
1391 &reloc_root
->root_key
, root_item
);
1399 * helper to find first cached inode with inode number >= objectid
1402 static struct inode
*find_next_inode(struct btrfs_root
*root
, u64 objectid
)
1404 struct rb_node
*node
;
1405 struct rb_node
*prev
;
1406 struct btrfs_inode
*entry
;
1407 struct inode
*inode
;
1409 spin_lock(&root
->inode_lock
);
1411 node
= root
->inode_tree
.rb_node
;
1415 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1417 if (objectid
< btrfs_ino(&entry
->vfs_inode
))
1418 node
= node
->rb_left
;
1419 else if (objectid
> btrfs_ino(&entry
->vfs_inode
))
1420 node
= node
->rb_right
;
1426 entry
= rb_entry(prev
, struct btrfs_inode
, rb_node
);
1427 if (objectid
<= btrfs_ino(&entry
->vfs_inode
)) {
1431 prev
= rb_next(prev
);
1435 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1436 inode
= igrab(&entry
->vfs_inode
);
1438 spin_unlock(&root
->inode_lock
);
1442 objectid
= btrfs_ino(&entry
->vfs_inode
) + 1;
1443 if (cond_resched_lock(&root
->inode_lock
))
1446 node
= rb_next(node
);
1448 spin_unlock(&root
->inode_lock
);
1452 static int in_block_group(u64 bytenr
,
1453 struct btrfs_block_group_cache
*block_group
)
1455 if (bytenr
>= block_group
->key
.objectid
&&
1456 bytenr
< block_group
->key
.objectid
+ block_group
->key
.offset
)
1462 * get new location of data
1464 static int get_new_location(struct inode
*reloc_inode
, u64
*new_bytenr
,
1465 u64 bytenr
, u64 num_bytes
)
1467 struct btrfs_root
*root
= BTRFS_I(reloc_inode
)->root
;
1468 struct btrfs_path
*path
;
1469 struct btrfs_file_extent_item
*fi
;
1470 struct extent_buffer
*leaf
;
1473 path
= btrfs_alloc_path();
1477 bytenr
-= BTRFS_I(reloc_inode
)->index_cnt
;
1478 ret
= btrfs_lookup_file_extent(NULL
, root
, path
, btrfs_ino(reloc_inode
),
1487 leaf
= path
->nodes
[0];
1488 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
1489 struct btrfs_file_extent_item
);
1491 BUG_ON(btrfs_file_extent_offset(leaf
, fi
) ||
1492 btrfs_file_extent_compression(leaf
, fi
) ||
1493 btrfs_file_extent_encryption(leaf
, fi
) ||
1494 btrfs_file_extent_other_encoding(leaf
, fi
));
1496 if (num_bytes
!= btrfs_file_extent_disk_num_bytes(leaf
, fi
)) {
1501 *new_bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1504 btrfs_free_path(path
);
1509 * update file extent items in the tree leaf to point to
1510 * the new locations.
1512 static noinline_for_stack
1513 int replace_file_extents(struct btrfs_trans_handle
*trans
,
1514 struct reloc_control
*rc
,
1515 struct btrfs_root
*root
,
1516 struct extent_buffer
*leaf
)
1518 struct btrfs_key key
;
1519 struct btrfs_file_extent_item
*fi
;
1520 struct inode
*inode
= NULL
;
1532 if (rc
->stage
!= UPDATE_DATA_PTRS
)
1535 /* reloc trees always use full backref */
1536 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1537 parent
= leaf
->start
;
1541 nritems
= btrfs_header_nritems(leaf
);
1542 for (i
= 0; i
< nritems
; i
++) {
1544 btrfs_item_key_to_cpu(leaf
, &key
, i
);
1545 if (key
.type
!= BTRFS_EXTENT_DATA_KEY
)
1547 fi
= btrfs_item_ptr(leaf
, i
, struct btrfs_file_extent_item
);
1548 if (btrfs_file_extent_type(leaf
, fi
) ==
1549 BTRFS_FILE_EXTENT_INLINE
)
1551 bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1552 num_bytes
= btrfs_file_extent_disk_num_bytes(leaf
, fi
);
1555 if (!in_block_group(bytenr
, rc
->block_group
))
1559 * if we are modifying block in fs tree, wait for readpage
1560 * to complete and drop the extent cache
1562 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
) {
1564 inode
= find_next_inode(root
, key
.objectid
);
1566 } else if (inode
&& btrfs_ino(inode
) < key
.objectid
) {
1567 btrfs_add_delayed_iput(inode
);
1568 inode
= find_next_inode(root
, key
.objectid
);
1570 if (inode
&& btrfs_ino(inode
) == key
.objectid
) {
1572 btrfs_file_extent_num_bytes(leaf
, fi
);
1573 WARN_ON(!IS_ALIGNED(key
.offset
,
1575 WARN_ON(!IS_ALIGNED(end
, root
->sectorsize
));
1577 ret
= try_lock_extent(&BTRFS_I(inode
)->io_tree
,
1583 btrfs_drop_extent_cache(inode
, key
.offset
, end
,
1585 unlock_extent(&BTRFS_I(inode
)->io_tree
,
1586 key
.offset
, end
, GFP_NOFS
);
1590 ret
= get_new_location(rc
->data_inode
, &new_bytenr
,
1598 btrfs_set_file_extent_disk_bytenr(leaf
, fi
, new_bytenr
);
1601 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
1602 ret
= btrfs_inc_extent_ref(trans
, root
, new_bytenr
,
1604 btrfs_header_owner(leaf
),
1605 key
.objectid
, key
.offset
);
1608 ret
= btrfs_free_extent(trans
, root
, bytenr
, num_bytes
,
1609 parent
, btrfs_header_owner(leaf
),
1610 key
.objectid
, key
.offset
);
1614 btrfs_mark_buffer_dirty(leaf
);
1616 btrfs_add_delayed_iput(inode
);
1620 static noinline_for_stack
1621 int memcmp_node_keys(struct extent_buffer
*eb
, int slot
,
1622 struct btrfs_path
*path
, int level
)
1624 struct btrfs_disk_key key1
;
1625 struct btrfs_disk_key key2
;
1626 btrfs_node_key(eb
, &key1
, slot
);
1627 btrfs_node_key(path
->nodes
[level
], &key2
, path
->slots
[level
]);
1628 return memcmp(&key1
, &key2
, sizeof(key1
));
1632 * try to replace tree blocks in fs tree with the new blocks
1633 * in reloc tree. tree blocks haven't been modified since the
1634 * reloc tree was create can be replaced.
1636 * if a block was replaced, level of the block + 1 is returned.
1637 * if no block got replaced, 0 is returned. if there are other
1638 * errors, a negative error number is returned.
1640 static noinline_for_stack
1641 int replace_path(struct btrfs_trans_handle
*trans
,
1642 struct btrfs_root
*dest
, struct btrfs_root
*src
,
1643 struct btrfs_path
*path
, struct btrfs_key
*next_key
,
1644 int lowest_level
, int max_level
)
1646 struct extent_buffer
*eb
;
1647 struct extent_buffer
*parent
;
1648 struct btrfs_key key
;
1660 BUG_ON(src
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
);
1661 BUG_ON(dest
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
);
1663 last_snapshot
= btrfs_root_last_snapshot(&src
->root_item
);
1665 slot
= path
->slots
[lowest_level
];
1666 btrfs_node_key_to_cpu(path
->nodes
[lowest_level
], &key
, slot
);
1668 eb
= btrfs_lock_root_node(dest
);
1669 btrfs_set_lock_blocking(eb
);
1670 level
= btrfs_header_level(eb
);
1672 if (level
< lowest_level
) {
1673 btrfs_tree_unlock(eb
);
1674 free_extent_buffer(eb
);
1679 ret
= btrfs_cow_block(trans
, dest
, eb
, NULL
, 0, &eb
);
1682 btrfs_set_lock_blocking(eb
);
1685 next_key
->objectid
= (u64
)-1;
1686 next_key
->type
= (u8
)-1;
1687 next_key
->offset
= (u64
)-1;
1692 level
= btrfs_header_level(parent
);
1693 BUG_ON(level
< lowest_level
);
1695 ret
= btrfs_bin_search(parent
, &key
, level
, &slot
);
1696 if (ret
&& slot
> 0)
1699 if (next_key
&& slot
+ 1 < btrfs_header_nritems(parent
))
1700 btrfs_node_key_to_cpu(parent
, next_key
, slot
+ 1);
1702 old_bytenr
= btrfs_node_blockptr(parent
, slot
);
1703 blocksize
= btrfs_level_size(dest
, level
- 1);
1704 old_ptr_gen
= btrfs_node_ptr_generation(parent
, slot
);
1706 if (level
<= max_level
) {
1707 eb
= path
->nodes
[level
];
1708 new_bytenr
= btrfs_node_blockptr(eb
,
1709 path
->slots
[level
]);
1710 new_ptr_gen
= btrfs_node_ptr_generation(eb
,
1711 path
->slots
[level
]);
1717 if (new_bytenr
> 0 && new_bytenr
== old_bytenr
) {
1723 if (new_bytenr
== 0 || old_ptr_gen
> last_snapshot
||
1724 memcmp_node_keys(parent
, slot
, path
, level
)) {
1725 if (level
<= lowest_level
) {
1730 eb
= read_tree_block(dest
, old_bytenr
, blocksize
,
1733 btrfs_tree_lock(eb
);
1735 ret
= btrfs_cow_block(trans
, dest
, eb
, parent
,
1739 btrfs_set_lock_blocking(eb
);
1741 btrfs_tree_unlock(parent
);
1742 free_extent_buffer(parent
);
1749 btrfs_tree_unlock(parent
);
1750 free_extent_buffer(parent
);
1755 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
1756 path
->slots
[level
]);
1757 btrfs_release_path(path
);
1759 path
->lowest_level
= level
;
1760 ret
= btrfs_search_slot(trans
, src
, &key
, path
, 0, 1);
1761 path
->lowest_level
= 0;
1765 * swap blocks in fs tree and reloc tree.
1767 btrfs_set_node_blockptr(parent
, slot
, new_bytenr
);
1768 btrfs_set_node_ptr_generation(parent
, slot
, new_ptr_gen
);
1769 btrfs_mark_buffer_dirty(parent
);
1771 btrfs_set_node_blockptr(path
->nodes
[level
],
1772 path
->slots
[level
], old_bytenr
);
1773 btrfs_set_node_ptr_generation(path
->nodes
[level
],
1774 path
->slots
[level
], old_ptr_gen
);
1775 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
1777 ret
= btrfs_inc_extent_ref(trans
, src
, old_bytenr
, blocksize
,
1778 path
->nodes
[level
]->start
,
1779 src
->root_key
.objectid
, level
- 1, 0);
1781 ret
= btrfs_inc_extent_ref(trans
, dest
, new_bytenr
, blocksize
,
1782 0, dest
->root_key
.objectid
, level
- 1,
1786 ret
= btrfs_free_extent(trans
, src
, new_bytenr
, blocksize
,
1787 path
->nodes
[level
]->start
,
1788 src
->root_key
.objectid
, level
- 1, 0);
1791 ret
= btrfs_free_extent(trans
, dest
, old_bytenr
, blocksize
,
1792 0, dest
->root_key
.objectid
, level
- 1,
1796 btrfs_unlock_up_safe(path
, 0);
1801 btrfs_tree_unlock(parent
);
1802 free_extent_buffer(parent
);
1807 * helper to find next relocated block in reloc tree
1809 static noinline_for_stack
1810 int walk_up_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1813 struct extent_buffer
*eb
;
1818 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1820 for (i
= 0; i
< *level
; i
++) {
1821 free_extent_buffer(path
->nodes
[i
]);
1822 path
->nodes
[i
] = NULL
;
1825 for (i
= *level
; i
< BTRFS_MAX_LEVEL
&& path
->nodes
[i
]; i
++) {
1826 eb
= path
->nodes
[i
];
1827 nritems
= btrfs_header_nritems(eb
);
1828 while (path
->slots
[i
] + 1 < nritems
) {
1830 if (btrfs_node_ptr_generation(eb
, path
->slots
[i
]) <=
1837 free_extent_buffer(path
->nodes
[i
]);
1838 path
->nodes
[i
] = NULL
;
1844 * walk down reloc tree to find relocated block of lowest level
1846 static noinline_for_stack
1847 int walk_down_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1850 struct extent_buffer
*eb
= NULL
;
1858 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1860 for (i
= *level
; i
> 0; i
--) {
1861 eb
= path
->nodes
[i
];
1862 nritems
= btrfs_header_nritems(eb
);
1863 while (path
->slots
[i
] < nritems
) {
1864 ptr_gen
= btrfs_node_ptr_generation(eb
, path
->slots
[i
]);
1865 if (ptr_gen
> last_snapshot
)
1869 if (path
->slots
[i
] >= nritems
) {
1880 bytenr
= btrfs_node_blockptr(eb
, path
->slots
[i
]);
1881 blocksize
= btrfs_level_size(root
, i
- 1);
1882 eb
= read_tree_block(root
, bytenr
, blocksize
, ptr_gen
);
1883 BUG_ON(btrfs_header_level(eb
) != i
- 1);
1884 path
->nodes
[i
- 1] = eb
;
1885 path
->slots
[i
- 1] = 0;
1891 * invalidate extent cache for file extents whose key in range of
1892 * [min_key, max_key)
1894 static int invalidate_extent_cache(struct btrfs_root
*root
,
1895 struct btrfs_key
*min_key
,
1896 struct btrfs_key
*max_key
)
1898 struct inode
*inode
= NULL
;
1903 objectid
= min_key
->objectid
;
1908 if (objectid
> max_key
->objectid
)
1911 inode
= find_next_inode(root
, objectid
);
1914 ino
= btrfs_ino(inode
);
1916 if (ino
> max_key
->objectid
) {
1922 if (!S_ISREG(inode
->i_mode
))
1925 if (unlikely(min_key
->objectid
== ino
)) {
1926 if (min_key
->type
> BTRFS_EXTENT_DATA_KEY
)
1928 if (min_key
->type
< BTRFS_EXTENT_DATA_KEY
)
1931 start
= min_key
->offset
;
1932 WARN_ON(!IS_ALIGNED(start
, root
->sectorsize
));
1938 if (unlikely(max_key
->objectid
== ino
)) {
1939 if (max_key
->type
< BTRFS_EXTENT_DATA_KEY
)
1941 if (max_key
->type
> BTRFS_EXTENT_DATA_KEY
) {
1944 if (max_key
->offset
== 0)
1946 end
= max_key
->offset
;
1947 WARN_ON(!IS_ALIGNED(end
, root
->sectorsize
));
1954 /* the lock_extent waits for readpage to complete */
1955 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
1956 btrfs_drop_extent_cache(inode
, start
, end
, 1);
1957 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
1962 static int find_next_key(struct btrfs_path
*path
, int level
,
1963 struct btrfs_key
*key
)
1966 while (level
< BTRFS_MAX_LEVEL
) {
1967 if (!path
->nodes
[level
])
1969 if (path
->slots
[level
] + 1 <
1970 btrfs_header_nritems(path
->nodes
[level
])) {
1971 btrfs_node_key_to_cpu(path
->nodes
[level
], key
,
1972 path
->slots
[level
] + 1);
1981 * merge the relocated tree blocks in reloc tree with corresponding
1984 static noinline_for_stack
int merge_reloc_root(struct reloc_control
*rc
,
1985 struct btrfs_root
*root
)
1987 LIST_HEAD(inode_list
);
1988 struct btrfs_key key
;
1989 struct btrfs_key next_key
;
1990 struct btrfs_trans_handle
*trans
;
1991 struct btrfs_root
*reloc_root
;
1992 struct btrfs_root_item
*root_item
;
1993 struct btrfs_path
*path
;
1994 struct extent_buffer
*leaf
;
2003 path
= btrfs_alloc_path();
2008 reloc_root
= root
->reloc_root
;
2009 root_item
= &reloc_root
->root_item
;
2011 if (btrfs_disk_key_objectid(&root_item
->drop_progress
) == 0) {
2012 level
= btrfs_root_level(root_item
);
2013 extent_buffer_get(reloc_root
->node
);
2014 path
->nodes
[level
] = reloc_root
->node
;
2015 path
->slots
[level
] = 0;
2017 btrfs_disk_key_to_cpu(&key
, &root_item
->drop_progress
);
2019 level
= root_item
->drop_level
;
2021 path
->lowest_level
= level
;
2022 ret
= btrfs_search_slot(NULL
, reloc_root
, &key
, path
, 0, 0);
2023 path
->lowest_level
= 0;
2025 btrfs_free_path(path
);
2029 btrfs_node_key_to_cpu(path
->nodes
[level
], &next_key
,
2030 path
->slots
[level
]);
2031 WARN_ON(memcmp(&key
, &next_key
, sizeof(key
)));
2033 btrfs_unlock_up_safe(path
, 0);
2036 min_reserved
= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2037 memset(&next_key
, 0, sizeof(next_key
));
2040 trans
= btrfs_start_transaction(root
, 0);
2041 BUG_ON(IS_ERR(trans
));
2042 trans
->block_rsv
= rc
->block_rsv
;
2044 ret
= btrfs_block_rsv_check(trans
, root
, rc
->block_rsv
,
2047 BUG_ON(ret
!= -EAGAIN
);
2048 ret
= btrfs_commit_transaction(trans
, root
);
2056 ret
= walk_down_reloc_tree(reloc_root
, path
, &level
);
2064 if (!find_next_key(path
, level
, &key
) &&
2065 btrfs_comp_cpu_keys(&next_key
, &key
) >= 0) {
2068 ret
= replace_path(trans
, root
, reloc_root
, path
,
2069 &next_key
, level
, max_level
);
2078 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
2079 path
->slots
[level
]);
2083 ret
= walk_up_reloc_tree(reloc_root
, path
, &level
);
2089 * save the merging progress in the drop_progress.
2090 * this is OK since root refs == 1 in this case.
2092 btrfs_node_key(path
->nodes
[level
], &root_item
->drop_progress
,
2093 path
->slots
[level
]);
2094 root_item
->drop_level
= level
;
2096 nr
= trans
->blocks_used
;
2097 btrfs_end_transaction_throttle(trans
, root
);
2099 btrfs_btree_balance_dirty(root
, nr
);
2101 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2102 invalidate_extent_cache(root
, &key
, &next_key
);
2106 * handle the case only one block in the fs tree need to be
2107 * relocated and the block is tree root.
2109 leaf
= btrfs_lock_root_node(root
);
2110 ret
= btrfs_cow_block(trans
, root
, leaf
, NULL
, 0, &leaf
);
2111 btrfs_tree_unlock(leaf
);
2112 free_extent_buffer(leaf
);
2116 btrfs_free_path(path
);
2119 memset(&root_item
->drop_progress
, 0,
2120 sizeof(root_item
->drop_progress
));
2121 root_item
->drop_level
= 0;
2122 btrfs_set_root_refs(root_item
, 0);
2123 btrfs_update_reloc_root(trans
, root
);
2126 nr
= trans
->blocks_used
;
2127 btrfs_end_transaction_throttle(trans
, root
);
2129 btrfs_btree_balance_dirty(root
, nr
);
2131 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2132 invalidate_extent_cache(root
, &key
, &next_key
);
2137 static noinline_for_stack
2138 int prepare_to_merge(struct reloc_control
*rc
, int err
)
2140 struct btrfs_root
*root
= rc
->extent_root
;
2141 struct btrfs_root
*reloc_root
;
2142 struct btrfs_trans_handle
*trans
;
2143 LIST_HEAD(reloc_roots
);
2147 mutex_lock(&root
->fs_info
->reloc_mutex
);
2148 rc
->merging_rsv_size
+= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2149 rc
->merging_rsv_size
+= rc
->nodes_relocated
* 2;
2150 mutex_unlock(&root
->fs_info
->reloc_mutex
);
2154 num_bytes
= rc
->merging_rsv_size
;
2155 ret
= btrfs_block_rsv_add(NULL
, root
, rc
->block_rsv
,
2161 trans
= btrfs_join_transaction(rc
->extent_root
);
2162 if (IS_ERR(trans
)) {
2164 btrfs_block_rsv_release(rc
->extent_root
,
2165 rc
->block_rsv
, num_bytes
);
2166 return PTR_ERR(trans
);
2170 if (num_bytes
!= rc
->merging_rsv_size
) {
2171 btrfs_end_transaction(trans
, rc
->extent_root
);
2172 btrfs_block_rsv_release(rc
->extent_root
,
2173 rc
->block_rsv
, num_bytes
);
2178 rc
->merge_reloc_tree
= 1;
2180 while (!list_empty(&rc
->reloc_roots
)) {
2181 reloc_root
= list_entry(rc
->reloc_roots
.next
,
2182 struct btrfs_root
, root_list
);
2183 list_del_init(&reloc_root
->root_list
);
2185 root
= read_fs_root(reloc_root
->fs_info
,
2186 reloc_root
->root_key
.offset
);
2187 BUG_ON(IS_ERR(root
));
2188 BUG_ON(root
->reloc_root
!= reloc_root
);
2191 * set reference count to 1, so btrfs_recover_relocation
2192 * knows it should resumes merging
2195 btrfs_set_root_refs(&reloc_root
->root_item
, 1);
2196 btrfs_update_reloc_root(trans
, root
);
2198 list_add(&reloc_root
->root_list
, &reloc_roots
);
2201 list_splice(&reloc_roots
, &rc
->reloc_roots
);
2204 btrfs_commit_transaction(trans
, rc
->extent_root
);
2206 btrfs_end_transaction(trans
, rc
->extent_root
);
2210 static noinline_for_stack
2211 int merge_reloc_roots(struct reloc_control
*rc
)
2213 struct btrfs_root
*root
;
2214 struct btrfs_root
*reloc_root
;
2215 LIST_HEAD(reloc_roots
);
2219 root
= rc
->extent_root
;
2222 * this serializes us with btrfs_record_root_in_transaction,
2223 * we have to make sure nobody is in the middle of
2224 * adding their roots to the list while we are
2227 mutex_lock(&root
->fs_info
->reloc_mutex
);
2228 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
2229 mutex_unlock(&root
->fs_info
->reloc_mutex
);
2231 while (!list_empty(&reloc_roots
)) {
2233 reloc_root
= list_entry(reloc_roots
.next
,
2234 struct btrfs_root
, root_list
);
2236 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
2237 root
= read_fs_root(reloc_root
->fs_info
,
2238 reloc_root
->root_key
.offset
);
2239 BUG_ON(IS_ERR(root
));
2240 BUG_ON(root
->reloc_root
!= reloc_root
);
2242 ret
= merge_reloc_root(rc
, root
);
2245 list_del_init(&reloc_root
->root_list
);
2247 btrfs_drop_snapshot(reloc_root
, rc
->block_rsv
, 0);
2254 BUG_ON(!RB_EMPTY_ROOT(&rc
->reloc_root_tree
.rb_root
));
2258 static void free_block_list(struct rb_root
*blocks
)
2260 struct tree_block
*block
;
2261 struct rb_node
*rb_node
;
2262 while ((rb_node
= rb_first(blocks
))) {
2263 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2264 rb_erase(rb_node
, blocks
);
2269 static int record_reloc_root_in_trans(struct btrfs_trans_handle
*trans
,
2270 struct btrfs_root
*reloc_root
)
2272 struct btrfs_root
*root
;
2274 if (reloc_root
->last_trans
== trans
->transid
)
2277 root
= read_fs_root(reloc_root
->fs_info
, reloc_root
->root_key
.offset
);
2278 BUG_ON(IS_ERR(root
));
2279 BUG_ON(root
->reloc_root
!= reloc_root
);
2281 return btrfs_record_root_in_trans(trans
, root
);
2284 static noinline_for_stack
2285 struct btrfs_root
*select_reloc_root(struct btrfs_trans_handle
*trans
,
2286 struct reloc_control
*rc
,
2287 struct backref_node
*node
,
2288 struct backref_edge
*edges
[], int *nr
)
2290 struct backref_node
*next
;
2291 struct btrfs_root
*root
;
2297 next
= walk_up_backref(next
, edges
, &index
);
2300 BUG_ON(!root
->ref_cows
);
2302 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
2303 record_reloc_root_in_trans(trans
, root
);
2307 btrfs_record_root_in_trans(trans
, root
);
2308 root
= root
->reloc_root
;
2310 if (next
->new_bytenr
!= root
->node
->start
) {
2311 BUG_ON(next
->new_bytenr
);
2312 BUG_ON(!list_empty(&next
->list
));
2313 next
->new_bytenr
= root
->node
->start
;
2315 list_add_tail(&next
->list
,
2316 &rc
->backref_cache
.changed
);
2317 __mark_block_processed(rc
, next
);
2323 next
= walk_down_backref(edges
, &index
);
2324 if (!next
|| next
->level
<= node
->level
)
2332 /* setup backref node path for btrfs_reloc_cow_block */
2334 rc
->backref_cache
.path
[next
->level
] = next
;
2337 next
= edges
[index
]->node
[UPPER
];
2343 * select a tree root for relocation. return NULL if the block
2344 * is reference counted. we should use do_relocation() in this
2345 * case. return a tree root pointer if the block isn't reference
2346 * counted. return -ENOENT if the block is root of reloc tree.
2348 static noinline_for_stack
2349 struct btrfs_root
*select_one_root(struct btrfs_trans_handle
*trans
,
2350 struct backref_node
*node
)
2352 struct backref_node
*next
;
2353 struct btrfs_root
*root
;
2354 struct btrfs_root
*fs_root
= NULL
;
2355 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2361 next
= walk_up_backref(next
, edges
, &index
);
2365 /* no other choice for non-references counted tree */
2366 if (!root
->ref_cows
)
2369 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
)
2375 next
= walk_down_backref(edges
, &index
);
2376 if (!next
|| next
->level
<= node
->level
)
2381 return ERR_PTR(-ENOENT
);
2385 static noinline_for_stack
2386 u64
calcu_metadata_size(struct reloc_control
*rc
,
2387 struct backref_node
*node
, int reserve
)
2389 struct backref_node
*next
= node
;
2390 struct backref_edge
*edge
;
2391 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2395 BUG_ON(reserve
&& node
->processed
);
2400 if (next
->processed
&& (reserve
|| next
!= node
))
2403 num_bytes
+= btrfs_level_size(rc
->extent_root
,
2406 if (list_empty(&next
->upper
))
2409 edge
= list_entry(next
->upper
.next
,
2410 struct backref_edge
, list
[LOWER
]);
2411 edges
[index
++] = edge
;
2412 next
= edge
->node
[UPPER
];
2414 next
= walk_down_backref(edges
, &index
);
2419 static int reserve_metadata_space(struct btrfs_trans_handle
*trans
,
2420 struct reloc_control
*rc
,
2421 struct backref_node
*node
)
2423 struct btrfs_root
*root
= rc
->extent_root
;
2427 num_bytes
= calcu_metadata_size(rc
, node
, 1) * 2;
2429 trans
->block_rsv
= rc
->block_rsv
;
2430 ret
= btrfs_block_rsv_add(trans
, root
, rc
->block_rsv
, num_bytes
);
2433 rc
->commit_transaction
= 1;
2440 static void release_metadata_space(struct reloc_control
*rc
,
2441 struct backref_node
*node
)
2443 u64 num_bytes
= calcu_metadata_size(rc
, node
, 0) * 2;
2444 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, num_bytes
);
2448 * relocate a block tree, and then update pointers in upper level
2449 * blocks that reference the block to point to the new location.
2451 * if called by link_to_upper, the block has already been relocated.
2452 * in that case this function just updates pointers.
2454 static int do_relocation(struct btrfs_trans_handle
*trans
,
2455 struct reloc_control
*rc
,
2456 struct backref_node
*node
,
2457 struct btrfs_key
*key
,
2458 struct btrfs_path
*path
, int lowest
)
2460 struct backref_node
*upper
;
2461 struct backref_edge
*edge
;
2462 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2463 struct btrfs_root
*root
;
2464 struct extent_buffer
*eb
;
2473 BUG_ON(lowest
&& node
->eb
);
2475 path
->lowest_level
= node
->level
+ 1;
2476 rc
->backref_cache
.path
[node
->level
] = node
;
2477 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
]) {
2480 upper
= edge
->node
[UPPER
];
2481 root
= select_reloc_root(trans
, rc
, upper
, edges
, &nr
);
2484 if (upper
->eb
&& !upper
->locked
) {
2486 ret
= btrfs_bin_search(upper
->eb
, key
,
2487 upper
->level
, &slot
);
2489 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2490 if (node
->eb
->start
== bytenr
)
2493 drop_node_buffer(upper
);
2497 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2505 upper
->eb
= path
->nodes
[upper
->level
];
2506 path
->nodes
[upper
->level
] = NULL
;
2508 BUG_ON(upper
->eb
!= path
->nodes
[upper
->level
]);
2512 path
->locks
[upper
->level
] = 0;
2514 slot
= path
->slots
[upper
->level
];
2515 btrfs_release_path(path
);
2517 ret
= btrfs_bin_search(upper
->eb
, key
, upper
->level
,
2522 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2524 BUG_ON(bytenr
!= node
->bytenr
);
2526 if (node
->eb
->start
== bytenr
)
2530 blocksize
= btrfs_level_size(root
, node
->level
);
2531 generation
= btrfs_node_ptr_generation(upper
->eb
, slot
);
2532 eb
= read_tree_block(root
, bytenr
, blocksize
, generation
);
2537 btrfs_tree_lock(eb
);
2538 btrfs_set_lock_blocking(eb
);
2541 ret
= btrfs_cow_block(trans
, root
, eb
, upper
->eb
,
2543 btrfs_tree_unlock(eb
);
2544 free_extent_buffer(eb
);
2549 BUG_ON(node
->eb
!= eb
);
2551 btrfs_set_node_blockptr(upper
->eb
, slot
,
2553 btrfs_set_node_ptr_generation(upper
->eb
, slot
,
2555 btrfs_mark_buffer_dirty(upper
->eb
);
2557 ret
= btrfs_inc_extent_ref(trans
, root
,
2558 node
->eb
->start
, blocksize
,
2560 btrfs_header_owner(upper
->eb
),
2564 ret
= btrfs_drop_subtree(trans
, root
, eb
, upper
->eb
);
2568 if (!upper
->pending
)
2569 drop_node_buffer(upper
);
2571 unlock_node_buffer(upper
);
2576 if (!err
&& node
->pending
) {
2577 drop_node_buffer(node
);
2578 list_move_tail(&node
->list
, &rc
->backref_cache
.changed
);
2582 path
->lowest_level
= 0;
2583 BUG_ON(err
== -ENOSPC
);
2587 static int link_to_upper(struct btrfs_trans_handle
*trans
,
2588 struct reloc_control
*rc
,
2589 struct backref_node
*node
,
2590 struct btrfs_path
*path
)
2592 struct btrfs_key key
;
2594 btrfs_node_key_to_cpu(node
->eb
, &key
, 0);
2595 return do_relocation(trans
, rc
, node
, &key
, path
, 0);
2598 static int finish_pending_nodes(struct btrfs_trans_handle
*trans
,
2599 struct reloc_control
*rc
,
2600 struct btrfs_path
*path
, int err
)
2603 struct backref_cache
*cache
= &rc
->backref_cache
;
2604 struct backref_node
*node
;
2608 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
2609 while (!list_empty(&cache
->pending
[level
])) {
2610 node
= list_entry(cache
->pending
[level
].next
,
2611 struct backref_node
, list
);
2612 list_move_tail(&node
->list
, &list
);
2613 BUG_ON(!node
->pending
);
2616 ret
= link_to_upper(trans
, rc
, node
, path
);
2621 list_splice_init(&list
, &cache
->pending
[level
]);
2626 static void mark_block_processed(struct reloc_control
*rc
,
2627 u64 bytenr
, u32 blocksize
)
2629 set_extent_bits(&rc
->processed_blocks
, bytenr
, bytenr
+ blocksize
- 1,
2630 EXTENT_DIRTY
, GFP_NOFS
);
2633 static void __mark_block_processed(struct reloc_control
*rc
,
2634 struct backref_node
*node
)
2637 if (node
->level
== 0 ||
2638 in_block_group(node
->bytenr
, rc
->block_group
)) {
2639 blocksize
= btrfs_level_size(rc
->extent_root
, node
->level
);
2640 mark_block_processed(rc
, node
->bytenr
, blocksize
);
2642 node
->processed
= 1;
2646 * mark a block and all blocks directly/indirectly reference the block
2649 static void update_processed_blocks(struct reloc_control
*rc
,
2650 struct backref_node
*node
)
2652 struct backref_node
*next
= node
;
2653 struct backref_edge
*edge
;
2654 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2660 if (next
->processed
)
2663 __mark_block_processed(rc
, next
);
2665 if (list_empty(&next
->upper
))
2668 edge
= list_entry(next
->upper
.next
,
2669 struct backref_edge
, list
[LOWER
]);
2670 edges
[index
++] = edge
;
2671 next
= edge
->node
[UPPER
];
2673 next
= walk_down_backref(edges
, &index
);
2677 static int tree_block_processed(u64 bytenr
, u32 blocksize
,
2678 struct reloc_control
*rc
)
2680 if (test_range_bit(&rc
->processed_blocks
, bytenr
,
2681 bytenr
+ blocksize
- 1, EXTENT_DIRTY
, 1, NULL
))
2686 static int get_tree_block_key(struct reloc_control
*rc
,
2687 struct tree_block
*block
)
2689 struct extent_buffer
*eb
;
2691 BUG_ON(block
->key_ready
);
2692 eb
= read_tree_block(rc
->extent_root
, block
->bytenr
,
2693 block
->key
.objectid
, block
->key
.offset
);
2695 WARN_ON(btrfs_header_level(eb
) != block
->level
);
2696 if (block
->level
== 0)
2697 btrfs_item_key_to_cpu(eb
, &block
->key
, 0);
2699 btrfs_node_key_to_cpu(eb
, &block
->key
, 0);
2700 free_extent_buffer(eb
);
2701 block
->key_ready
= 1;
2705 static int reada_tree_block(struct reloc_control
*rc
,
2706 struct tree_block
*block
)
2708 BUG_ON(block
->key_ready
);
2709 readahead_tree_block(rc
->extent_root
, block
->bytenr
,
2710 block
->key
.objectid
, block
->key
.offset
);
2715 * helper function to relocate a tree block
2717 static int relocate_tree_block(struct btrfs_trans_handle
*trans
,
2718 struct reloc_control
*rc
,
2719 struct backref_node
*node
,
2720 struct btrfs_key
*key
,
2721 struct btrfs_path
*path
)
2723 struct btrfs_root
*root
;
2730 BUG_ON(node
->processed
);
2731 root
= select_one_root(trans
, node
);
2732 if (root
== ERR_PTR(-ENOENT
)) {
2733 update_processed_blocks(rc
, node
);
2737 if (!root
|| root
->ref_cows
) {
2738 ret
= reserve_metadata_space(trans
, rc
, node
);
2745 if (root
->ref_cows
) {
2746 BUG_ON(node
->new_bytenr
);
2747 BUG_ON(!list_empty(&node
->list
));
2748 btrfs_record_root_in_trans(trans
, root
);
2749 root
= root
->reloc_root
;
2750 node
->new_bytenr
= root
->node
->start
;
2752 list_add_tail(&node
->list
, &rc
->backref_cache
.changed
);
2754 path
->lowest_level
= node
->level
;
2755 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2756 btrfs_release_path(path
);
2761 update_processed_blocks(rc
, node
);
2763 ret
= do_relocation(trans
, rc
, node
, key
, path
, 1);
2766 if (ret
|| node
->level
== 0 || node
->cowonly
) {
2768 release_metadata_space(rc
, node
);
2769 remove_backref_node(&rc
->backref_cache
, node
);
2775 * relocate a list of blocks
2777 static noinline_for_stack
2778 int relocate_tree_blocks(struct btrfs_trans_handle
*trans
,
2779 struct reloc_control
*rc
, struct rb_root
*blocks
)
2781 struct backref_node
*node
;
2782 struct btrfs_path
*path
;
2783 struct tree_block
*block
;
2784 struct rb_node
*rb_node
;
2788 path
= btrfs_alloc_path();
2792 rb_node
= rb_first(blocks
);
2794 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2795 if (!block
->key_ready
)
2796 reada_tree_block(rc
, block
);
2797 rb_node
= rb_next(rb_node
);
2800 rb_node
= rb_first(blocks
);
2802 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2803 if (!block
->key_ready
)
2804 get_tree_block_key(rc
, block
);
2805 rb_node
= rb_next(rb_node
);
2808 rb_node
= rb_first(blocks
);
2810 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2812 node
= build_backref_tree(rc
, &block
->key
,
2813 block
->level
, block
->bytenr
);
2815 err
= PTR_ERR(node
);
2819 ret
= relocate_tree_block(trans
, rc
, node
, &block
->key
,
2822 if (ret
!= -EAGAIN
|| rb_node
== rb_first(blocks
))
2826 rb_node
= rb_next(rb_node
);
2829 free_block_list(blocks
);
2830 err
= finish_pending_nodes(trans
, rc
, path
, err
);
2832 btrfs_free_path(path
);
2836 static noinline_for_stack
2837 int prealloc_file_extent_cluster(struct inode
*inode
,
2838 struct file_extent_cluster
*cluster
)
2843 u64 offset
= BTRFS_I(inode
)->index_cnt
;
2848 BUG_ON(cluster
->start
!= cluster
->boundary
[0]);
2849 mutex_lock(&inode
->i_mutex
);
2851 ret
= btrfs_check_data_free_space(inode
, cluster
->end
+
2852 1 - cluster
->start
);
2856 while (nr
< cluster
->nr
) {
2857 start
= cluster
->boundary
[nr
] - offset
;
2858 if (nr
+ 1 < cluster
->nr
)
2859 end
= cluster
->boundary
[nr
+ 1] - 1 - offset
;
2861 end
= cluster
->end
- offset
;
2863 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2864 num_bytes
= end
+ 1 - start
;
2865 ret
= btrfs_prealloc_file_range(inode
, 0, start
,
2866 num_bytes
, num_bytes
,
2867 end
+ 1, &alloc_hint
);
2868 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2873 btrfs_free_reserved_data_space(inode
, cluster
->end
+
2874 1 - cluster
->start
);
2876 mutex_unlock(&inode
->i_mutex
);
2880 static noinline_for_stack
2881 int setup_extent_mapping(struct inode
*inode
, u64 start
, u64 end
,
2884 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
2885 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2886 struct extent_map
*em
;
2889 em
= alloc_extent_map();
2894 em
->len
= end
+ 1 - start
;
2895 em
->block_len
= em
->len
;
2896 em
->block_start
= block_start
;
2897 em
->bdev
= root
->fs_info
->fs_devices
->latest_bdev
;
2898 set_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
2900 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2902 write_lock(&em_tree
->lock
);
2903 ret
= add_extent_mapping(em_tree
, em
);
2904 write_unlock(&em_tree
->lock
);
2905 if (ret
!= -EEXIST
) {
2906 free_extent_map(em
);
2909 btrfs_drop_extent_cache(inode
, start
, end
, 0);
2911 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2915 static int relocate_file_extent_cluster(struct inode
*inode
,
2916 struct file_extent_cluster
*cluster
)
2920 u64 offset
= BTRFS_I(inode
)->index_cnt
;
2921 unsigned long index
;
2922 unsigned long last_index
;
2924 struct file_ra_state
*ra
;
2931 ra
= kzalloc(sizeof(*ra
), GFP_NOFS
);
2935 ret
= prealloc_file_extent_cluster(inode
, cluster
);
2939 file_ra_state_init(ra
, inode
->i_mapping
);
2941 ret
= setup_extent_mapping(inode
, cluster
->start
- offset
,
2942 cluster
->end
- offset
, cluster
->start
);
2946 index
= (cluster
->start
- offset
) >> PAGE_CACHE_SHIFT
;
2947 last_index
= (cluster
->end
- offset
) >> PAGE_CACHE_SHIFT
;
2948 while (index
<= last_index
) {
2949 ret
= btrfs_delalloc_reserve_metadata(inode
, PAGE_CACHE_SIZE
);
2953 page
= find_lock_page(inode
->i_mapping
, index
);
2955 page_cache_sync_readahead(inode
->i_mapping
,
2957 last_index
+ 1 - index
);
2958 page
= grab_cache_page(inode
->i_mapping
, index
);
2960 btrfs_delalloc_release_metadata(inode
,
2967 if (PageReadahead(page
)) {
2968 page_cache_async_readahead(inode
->i_mapping
,
2969 ra
, NULL
, page
, index
,
2970 last_index
+ 1 - index
);
2973 if (!PageUptodate(page
)) {
2974 btrfs_readpage(NULL
, page
);
2976 if (!PageUptodate(page
)) {
2978 page_cache_release(page
);
2979 btrfs_delalloc_release_metadata(inode
,
2986 page_start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2987 page_end
= page_start
+ PAGE_CACHE_SIZE
- 1;
2989 lock_extent(&BTRFS_I(inode
)->io_tree
,
2990 page_start
, page_end
, GFP_NOFS
);
2992 set_page_extent_mapped(page
);
2994 if (nr
< cluster
->nr
&&
2995 page_start
+ offset
== cluster
->boundary
[nr
]) {
2996 set_extent_bits(&BTRFS_I(inode
)->io_tree
,
2997 page_start
, page_end
,
2998 EXTENT_BOUNDARY
, GFP_NOFS
);
3002 btrfs_set_extent_delalloc(inode
, page_start
, page_end
, NULL
);
3003 set_page_dirty(page
);
3005 unlock_extent(&BTRFS_I(inode
)->io_tree
,
3006 page_start
, page_end
, GFP_NOFS
);
3008 page_cache_release(page
);
3011 balance_dirty_pages_ratelimited(inode
->i_mapping
);
3012 btrfs_throttle(BTRFS_I(inode
)->root
);
3014 WARN_ON(nr
!= cluster
->nr
);
3020 static noinline_for_stack
3021 int relocate_data_extent(struct inode
*inode
, struct btrfs_key
*extent_key
,
3022 struct file_extent_cluster
*cluster
)
3026 if (cluster
->nr
> 0 && extent_key
->objectid
!= cluster
->end
+ 1) {
3027 ret
= relocate_file_extent_cluster(inode
, cluster
);
3034 cluster
->start
= extent_key
->objectid
;
3036 BUG_ON(cluster
->nr
>= MAX_EXTENTS
);
3037 cluster
->end
= extent_key
->objectid
+ extent_key
->offset
- 1;
3038 cluster
->boundary
[cluster
->nr
] = extent_key
->objectid
;
3041 if (cluster
->nr
>= MAX_EXTENTS
) {
3042 ret
= relocate_file_extent_cluster(inode
, cluster
);
3050 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3051 static int get_ref_objectid_v0(struct reloc_control
*rc
,
3052 struct btrfs_path
*path
,
3053 struct btrfs_key
*extent_key
,
3054 u64
*ref_objectid
, int *path_change
)
3056 struct btrfs_key key
;
3057 struct extent_buffer
*leaf
;
3058 struct btrfs_extent_ref_v0
*ref0
;
3062 leaf
= path
->nodes
[0];
3063 slot
= path
->slots
[0];
3065 if (slot
>= btrfs_header_nritems(leaf
)) {
3066 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3070 leaf
= path
->nodes
[0];
3071 slot
= path
->slots
[0];
3075 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
3076 if (key
.objectid
!= extent_key
->objectid
)
3079 if (key
.type
!= BTRFS_EXTENT_REF_V0_KEY
) {
3083 ref0
= btrfs_item_ptr(leaf
, slot
,
3084 struct btrfs_extent_ref_v0
);
3085 *ref_objectid
= btrfs_ref_objectid_v0(leaf
, ref0
);
3093 * helper to add a tree block to the list.
3094 * the major work is getting the generation and level of the block
3096 static int add_tree_block(struct reloc_control
*rc
,
3097 struct btrfs_key
*extent_key
,
3098 struct btrfs_path
*path
,
3099 struct rb_root
*blocks
)
3101 struct extent_buffer
*eb
;
3102 struct btrfs_extent_item
*ei
;
3103 struct btrfs_tree_block_info
*bi
;
3104 struct tree_block
*block
;
3105 struct rb_node
*rb_node
;
3110 eb
= path
->nodes
[0];
3111 item_size
= btrfs_item_size_nr(eb
, path
->slots
[0]);
3113 if (item_size
>= sizeof(*ei
) + sizeof(*bi
)) {
3114 ei
= btrfs_item_ptr(eb
, path
->slots
[0],
3115 struct btrfs_extent_item
);
3116 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
3117 generation
= btrfs_extent_generation(eb
, ei
);
3118 level
= btrfs_tree_block_level(eb
, bi
);
3120 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3124 BUG_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
3125 ret
= get_ref_objectid_v0(rc
, path
, extent_key
,
3129 BUG_ON(ref_owner
>= BTRFS_MAX_LEVEL
);
3130 level
= (int)ref_owner
;
3131 /* FIXME: get real generation */
3138 btrfs_release_path(path
);
3140 BUG_ON(level
== -1);
3142 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3146 block
->bytenr
= extent_key
->objectid
;
3147 block
->key
.objectid
= extent_key
->offset
;
3148 block
->key
.offset
= generation
;
3149 block
->level
= level
;
3150 block
->key_ready
= 0;
3152 rb_node
= tree_insert(blocks
, block
->bytenr
, &block
->rb_node
);
3159 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3161 static int __add_tree_block(struct reloc_control
*rc
,
3162 u64 bytenr
, u32 blocksize
,
3163 struct rb_root
*blocks
)
3165 struct btrfs_path
*path
;
3166 struct btrfs_key key
;
3169 if (tree_block_processed(bytenr
, blocksize
, rc
))
3172 if (tree_search(blocks
, bytenr
))
3175 path
= btrfs_alloc_path();
3179 key
.objectid
= bytenr
;
3180 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3181 key
.offset
= blocksize
;
3183 path
->search_commit_root
= 1;
3184 path
->skip_locking
= 1;
3185 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
, 0, 0);
3190 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, path
->slots
[0]);
3191 ret
= add_tree_block(rc
, &key
, path
, blocks
);
3193 btrfs_free_path(path
);
3198 * helper to check if the block use full backrefs for pointers in it
3200 static int block_use_full_backref(struct reloc_control
*rc
,
3201 struct extent_buffer
*eb
)
3206 if (btrfs_header_flag(eb
, BTRFS_HEADER_FLAG_RELOC
) ||
3207 btrfs_header_backref_rev(eb
) < BTRFS_MIXED_BACKREF_REV
)
3210 ret
= btrfs_lookup_extent_info(NULL
, rc
->extent_root
,
3211 eb
->start
, eb
->len
, NULL
, &flags
);
3214 if (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
)
3221 static int delete_block_group_cache(struct btrfs_fs_info
*fs_info
,
3222 struct inode
*inode
, u64 ino
)
3224 struct btrfs_key key
;
3225 struct btrfs_path
*path
;
3226 struct btrfs_root
*root
= fs_info
->tree_root
;
3227 struct btrfs_trans_handle
*trans
;
3235 key
.type
= BTRFS_INODE_ITEM_KEY
;
3238 inode
= btrfs_iget(fs_info
->sb
, &key
, root
, NULL
);
3239 if (IS_ERR_OR_NULL(inode
) || is_bad_inode(inode
)) {
3240 if (inode
&& !IS_ERR(inode
))
3246 path
= btrfs_alloc_path();
3252 trans
= btrfs_join_transaction(root
);
3253 if (IS_ERR(trans
)) {
3254 btrfs_free_path(path
);
3255 ret
= PTR_ERR(trans
);
3259 ret
= btrfs_truncate_free_space_cache(root
, trans
, path
, inode
);
3261 btrfs_free_path(path
);
3262 nr
= trans
->blocks_used
;
3263 btrfs_end_transaction(trans
, root
);
3264 btrfs_btree_balance_dirty(root
, nr
);
3271 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3272 * this function scans fs tree to find blocks reference the data extent
3274 static int find_data_references(struct reloc_control
*rc
,
3275 struct btrfs_key
*extent_key
,
3276 struct extent_buffer
*leaf
,
3277 struct btrfs_extent_data_ref
*ref
,
3278 struct rb_root
*blocks
)
3280 struct btrfs_path
*path
;
3281 struct tree_block
*block
;
3282 struct btrfs_root
*root
;
3283 struct btrfs_file_extent_item
*fi
;
3284 struct rb_node
*rb_node
;
3285 struct btrfs_key key
;
3296 ref_root
= btrfs_extent_data_ref_root(leaf
, ref
);
3297 ref_objectid
= btrfs_extent_data_ref_objectid(leaf
, ref
);
3298 ref_offset
= btrfs_extent_data_ref_offset(leaf
, ref
);
3299 ref_count
= btrfs_extent_data_ref_count(leaf
, ref
);
3302 * This is an extent belonging to the free space cache, lets just delete
3303 * it and redo the search.
3305 if (ref_root
== BTRFS_ROOT_TREE_OBJECTID
) {
3306 ret
= delete_block_group_cache(rc
->extent_root
->fs_info
,
3307 NULL
, ref_objectid
);
3313 path
= btrfs_alloc_path();
3318 root
= read_fs_root(rc
->extent_root
->fs_info
, ref_root
);
3320 err
= PTR_ERR(root
);
3324 key
.objectid
= ref_objectid
;
3325 key
.offset
= ref_offset
;
3326 key
.type
= BTRFS_EXTENT_DATA_KEY
;
3328 path
->search_commit_root
= 1;
3329 path
->skip_locking
= 1;
3330 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
3336 leaf
= path
->nodes
[0];
3337 nritems
= btrfs_header_nritems(leaf
);
3339 * the references in tree blocks that use full backrefs
3340 * are not counted in
3342 if (block_use_full_backref(rc
, leaf
))
3346 rb_node
= tree_search(blocks
, leaf
->start
);
3351 path
->slots
[0] = nritems
;
3354 while (ref_count
> 0) {
3355 while (path
->slots
[0] >= nritems
) {
3356 ret
= btrfs_next_leaf(root
, path
);
3366 leaf
= path
->nodes
[0];
3367 nritems
= btrfs_header_nritems(leaf
);
3370 if (block_use_full_backref(rc
, leaf
))
3374 rb_node
= tree_search(blocks
, leaf
->start
);
3379 path
->slots
[0] = nritems
;
3383 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3384 if (key
.objectid
!= ref_objectid
||
3385 key
.type
!= BTRFS_EXTENT_DATA_KEY
) {
3390 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3391 struct btrfs_file_extent_item
);
3393 if (btrfs_file_extent_type(leaf
, fi
) ==
3394 BTRFS_FILE_EXTENT_INLINE
)
3397 if (btrfs_file_extent_disk_bytenr(leaf
, fi
) !=
3398 extent_key
->objectid
)
3401 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
3402 if (key
.offset
!= ref_offset
)
3410 if (!tree_block_processed(leaf
->start
, leaf
->len
, rc
)) {
3411 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3416 block
->bytenr
= leaf
->start
;
3417 btrfs_item_key_to_cpu(leaf
, &block
->key
, 0);
3419 block
->key_ready
= 1;
3420 rb_node
= tree_insert(blocks
, block
->bytenr
,
3427 path
->slots
[0] = nritems
;
3433 btrfs_free_path(path
);
3438 * hepler to find all tree blocks that reference a given data extent
3440 static noinline_for_stack
3441 int add_data_references(struct reloc_control
*rc
,
3442 struct btrfs_key
*extent_key
,
3443 struct btrfs_path
*path
,
3444 struct rb_root
*blocks
)
3446 struct btrfs_key key
;
3447 struct extent_buffer
*eb
;
3448 struct btrfs_extent_data_ref
*dref
;
3449 struct btrfs_extent_inline_ref
*iref
;
3452 u32 blocksize
= btrfs_level_size(rc
->extent_root
, 0);
3456 eb
= path
->nodes
[0];
3457 ptr
= btrfs_item_ptr_offset(eb
, path
->slots
[0]);
3458 end
= ptr
+ btrfs_item_size_nr(eb
, path
->slots
[0]);
3459 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3460 if (ptr
+ sizeof(struct btrfs_extent_item_v0
) == end
)
3464 ptr
+= sizeof(struct btrfs_extent_item
);
3467 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
3468 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
3469 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3470 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
3471 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3473 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3474 dref
= (struct btrfs_extent_data_ref
*)(&iref
->offset
);
3475 ret
= find_data_references(rc
, extent_key
,
3480 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
3486 eb
= path
->nodes
[0];
3487 if (path
->slots
[0] >= btrfs_header_nritems(eb
)) {
3488 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3495 eb
= path
->nodes
[0];
3498 btrfs_item_key_to_cpu(eb
, &key
, path
->slots
[0]);
3499 if (key
.objectid
!= extent_key
->objectid
)
3502 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3503 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
||
3504 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
3506 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
3507 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3509 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3511 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3512 dref
= btrfs_item_ptr(eb
, path
->slots
[0],
3513 struct btrfs_extent_data_ref
);
3514 ret
= find_data_references(rc
, extent_key
,
3525 btrfs_release_path(path
);
3527 free_block_list(blocks
);
3532 * hepler to find next unprocessed extent
3534 static noinline_for_stack
3535 int find_next_extent(struct btrfs_trans_handle
*trans
,
3536 struct reloc_control
*rc
, struct btrfs_path
*path
,
3537 struct btrfs_key
*extent_key
)
3539 struct btrfs_key key
;
3540 struct extent_buffer
*leaf
;
3541 u64 start
, end
, last
;
3544 last
= rc
->block_group
->key
.objectid
+ rc
->block_group
->key
.offset
;
3547 if (rc
->search_start
>= last
) {
3552 key
.objectid
= rc
->search_start
;
3553 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3556 path
->search_commit_root
= 1;
3557 path
->skip_locking
= 1;
3558 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
,
3563 leaf
= path
->nodes
[0];
3564 if (path
->slots
[0] >= btrfs_header_nritems(leaf
)) {
3565 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3568 leaf
= path
->nodes
[0];
3571 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3572 if (key
.objectid
>= last
) {
3577 if (key
.type
!= BTRFS_EXTENT_ITEM_KEY
||
3578 key
.objectid
+ key
.offset
<= rc
->search_start
) {
3583 ret
= find_first_extent_bit(&rc
->processed_blocks
,
3584 key
.objectid
, &start
, &end
,
3587 if (ret
== 0 && start
<= key
.objectid
) {
3588 btrfs_release_path(path
);
3589 rc
->search_start
= end
+ 1;
3591 rc
->search_start
= key
.objectid
+ key
.offset
;
3592 memcpy(extent_key
, &key
, sizeof(key
));
3596 btrfs_release_path(path
);
3600 static void set_reloc_control(struct reloc_control
*rc
)
3602 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3604 mutex_lock(&fs_info
->reloc_mutex
);
3605 fs_info
->reloc_ctl
= rc
;
3606 mutex_unlock(&fs_info
->reloc_mutex
);
3609 static void unset_reloc_control(struct reloc_control
*rc
)
3611 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3613 mutex_lock(&fs_info
->reloc_mutex
);
3614 fs_info
->reloc_ctl
= NULL
;
3615 mutex_unlock(&fs_info
->reloc_mutex
);
3618 static int check_extent_flags(u64 flags
)
3620 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3621 (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3623 if (!(flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3624 !(flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3626 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3627 (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
))
3632 static noinline_for_stack
3633 int prepare_to_relocate(struct reloc_control
*rc
)
3635 struct btrfs_trans_handle
*trans
;
3638 rc
->block_rsv
= btrfs_alloc_block_rsv(rc
->extent_root
);
3643 * reserve some space for creating reloc trees.
3644 * btrfs_init_reloc_root will use them when there
3645 * is no reservation in transaction handle.
3647 ret
= btrfs_block_rsv_add(NULL
, rc
->extent_root
, rc
->block_rsv
,
3648 rc
->extent_root
->nodesize
* 256);
3652 rc
->block_rsv
->refill_used
= 1;
3653 btrfs_add_durable_block_rsv(rc
->extent_root
->fs_info
, rc
->block_rsv
);
3655 memset(&rc
->cluster
, 0, sizeof(rc
->cluster
));
3656 rc
->search_start
= rc
->block_group
->key
.objectid
;
3657 rc
->extents_found
= 0;
3658 rc
->nodes_relocated
= 0;
3659 rc
->merging_rsv_size
= 0;
3661 rc
->create_reloc_tree
= 1;
3662 set_reloc_control(rc
);
3664 trans
= btrfs_join_transaction(rc
->extent_root
);
3665 BUG_ON(IS_ERR(trans
));
3666 btrfs_commit_transaction(trans
, rc
->extent_root
);
3670 static noinline_for_stack
int relocate_block_group(struct reloc_control
*rc
)
3672 struct rb_root blocks
= RB_ROOT
;
3673 struct btrfs_key key
;
3674 struct btrfs_trans_handle
*trans
= NULL
;
3675 struct btrfs_path
*path
;
3676 struct btrfs_extent_item
*ei
;
3684 path
= btrfs_alloc_path();
3689 ret
= prepare_to_relocate(rc
);
3697 trans
= btrfs_start_transaction(rc
->extent_root
, 0);
3698 BUG_ON(IS_ERR(trans
));
3700 if (update_backref_cache(trans
, &rc
->backref_cache
)) {
3701 btrfs_end_transaction(trans
, rc
->extent_root
);
3705 ret
= find_next_extent(trans
, rc
, path
, &key
);
3711 rc
->extents_found
++;
3713 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
3714 struct btrfs_extent_item
);
3715 item_size
= btrfs_item_size_nr(path
->nodes
[0], path
->slots
[0]);
3716 if (item_size
>= sizeof(*ei
)) {
3717 flags
= btrfs_extent_flags(path
->nodes
[0], ei
);
3718 ret
= check_extent_flags(flags
);
3722 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3724 int path_change
= 0;
3727 sizeof(struct btrfs_extent_item_v0
));
3728 ret
= get_ref_objectid_v0(rc
, path
, &key
, &ref_owner
,
3730 if (ref_owner
< BTRFS_FIRST_FREE_OBJECTID
)
3731 flags
= BTRFS_EXTENT_FLAG_TREE_BLOCK
;
3733 flags
= BTRFS_EXTENT_FLAG_DATA
;
3736 btrfs_release_path(path
);
3738 path
->search_commit_root
= 1;
3739 path
->skip_locking
= 1;
3740 ret
= btrfs_search_slot(NULL
, rc
->extent_root
,
3753 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
3754 ret
= add_tree_block(rc
, &key
, path
, &blocks
);
3755 } else if (rc
->stage
== UPDATE_DATA_PTRS
&&
3756 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
3757 ret
= add_data_references(rc
, &key
, path
, &blocks
);
3759 btrfs_release_path(path
);
3767 if (!RB_EMPTY_ROOT(&blocks
)) {
3768 ret
= relocate_tree_blocks(trans
, rc
, &blocks
);
3770 if (ret
!= -EAGAIN
) {
3774 rc
->extents_found
--;
3775 rc
->search_start
= key
.objectid
;
3779 ret
= btrfs_block_rsv_check(trans
, rc
->extent_root
,
3780 rc
->block_rsv
, 0, 5);
3782 if (ret
!= -EAGAIN
) {
3787 rc
->commit_transaction
= 1;
3790 if (rc
->commit_transaction
) {
3791 rc
->commit_transaction
= 0;
3792 ret
= btrfs_commit_transaction(trans
, rc
->extent_root
);
3795 nr
= trans
->blocks_used
;
3796 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
3797 btrfs_btree_balance_dirty(rc
->extent_root
, nr
);
3801 if (rc
->stage
== MOVE_DATA_EXTENTS
&&
3802 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
3803 rc
->found_file_extent
= 1;
3804 ret
= relocate_data_extent(rc
->data_inode
,
3805 &key
, &rc
->cluster
);
3812 if (trans
&& progress
&& err
== -ENOSPC
) {
3813 ret
= btrfs_force_chunk_alloc(trans
, rc
->extent_root
,
3814 rc
->block_group
->flags
);
3822 btrfs_release_path(path
);
3823 clear_extent_bits(&rc
->processed_blocks
, 0, (u64
)-1, EXTENT_DIRTY
,
3827 nr
= trans
->blocks_used
;
3828 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
3829 btrfs_btree_balance_dirty(rc
->extent_root
, nr
);
3833 ret
= relocate_file_extent_cluster(rc
->data_inode
,
3839 rc
->create_reloc_tree
= 0;
3840 set_reloc_control(rc
);
3842 backref_cache_cleanup(&rc
->backref_cache
);
3843 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
3845 err
= prepare_to_merge(rc
, err
);
3847 merge_reloc_roots(rc
);
3849 rc
->merge_reloc_tree
= 0;
3850 unset_reloc_control(rc
);
3851 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
3853 /* get rid of pinned extents */
3854 trans
= btrfs_join_transaction(rc
->extent_root
);
3856 err
= PTR_ERR(trans
);
3858 btrfs_commit_transaction(trans
, rc
->extent_root
);
3860 btrfs_free_block_rsv(rc
->extent_root
, rc
->block_rsv
);
3861 btrfs_free_path(path
);
3865 static int __insert_orphan_inode(struct btrfs_trans_handle
*trans
,
3866 struct btrfs_root
*root
, u64 objectid
)
3868 struct btrfs_path
*path
;
3869 struct btrfs_inode_item
*item
;
3870 struct extent_buffer
*leaf
;
3873 path
= btrfs_alloc_path();
3877 ret
= btrfs_insert_empty_inode(trans
, root
, path
, objectid
);
3881 leaf
= path
->nodes
[0];
3882 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_inode_item
);
3883 memset_extent_buffer(leaf
, 0, (unsigned long)item
, sizeof(*item
));
3884 btrfs_set_inode_generation(leaf
, item
, 1);
3885 btrfs_set_inode_size(leaf
, item
, 0);
3886 btrfs_set_inode_mode(leaf
, item
, S_IFREG
| 0600);
3887 btrfs_set_inode_flags(leaf
, item
, BTRFS_INODE_NOCOMPRESS
|
3888 BTRFS_INODE_PREALLOC
);
3889 btrfs_mark_buffer_dirty(leaf
);
3890 btrfs_release_path(path
);
3892 btrfs_free_path(path
);
3897 * helper to create inode for data relocation.
3898 * the inode is in data relocation tree and its link count is 0
3900 static noinline_for_stack
3901 struct inode
*create_reloc_inode(struct btrfs_fs_info
*fs_info
,
3902 struct btrfs_block_group_cache
*group
)
3904 struct inode
*inode
= NULL
;
3905 struct btrfs_trans_handle
*trans
;
3906 struct btrfs_root
*root
;
3907 struct btrfs_key key
;
3909 u64 objectid
= BTRFS_FIRST_FREE_OBJECTID
;
3912 root
= read_fs_root(fs_info
, BTRFS_DATA_RELOC_TREE_OBJECTID
);
3914 return ERR_CAST(root
);
3916 trans
= btrfs_start_transaction(root
, 6);
3918 return ERR_CAST(trans
);
3920 err
= btrfs_find_free_objectid(root
, &objectid
);
3924 err
= __insert_orphan_inode(trans
, root
, objectid
);
3927 key
.objectid
= objectid
;
3928 key
.type
= BTRFS_INODE_ITEM_KEY
;
3930 inode
= btrfs_iget(root
->fs_info
->sb
, &key
, root
, NULL
);
3931 BUG_ON(IS_ERR(inode
) || is_bad_inode(inode
));
3932 BTRFS_I(inode
)->index_cnt
= group
->key
.objectid
;
3934 err
= btrfs_orphan_add(trans
, inode
);
3936 nr
= trans
->blocks_used
;
3937 btrfs_end_transaction(trans
, root
);
3938 btrfs_btree_balance_dirty(root
, nr
);
3942 inode
= ERR_PTR(err
);
3947 static struct reloc_control
*alloc_reloc_control(void)
3949 struct reloc_control
*rc
;
3951 rc
= kzalloc(sizeof(*rc
), GFP_NOFS
);
3955 INIT_LIST_HEAD(&rc
->reloc_roots
);
3956 backref_cache_init(&rc
->backref_cache
);
3957 mapping_tree_init(&rc
->reloc_root_tree
);
3958 extent_io_tree_init(&rc
->processed_blocks
, NULL
);
3963 * function to relocate all extents in a block group.
3965 int btrfs_relocate_block_group(struct btrfs_root
*extent_root
, u64 group_start
)
3967 struct btrfs_fs_info
*fs_info
= extent_root
->fs_info
;
3968 struct reloc_control
*rc
;
3969 struct inode
*inode
;
3970 struct btrfs_path
*path
;
3975 rc
= alloc_reloc_control();
3979 rc
->extent_root
= extent_root
;
3981 rc
->block_group
= btrfs_lookup_block_group(fs_info
, group_start
);
3982 BUG_ON(!rc
->block_group
);
3984 if (!rc
->block_group
->ro
) {
3985 ret
= btrfs_set_block_group_ro(extent_root
, rc
->block_group
);
3993 path
= btrfs_alloc_path();
3999 inode
= lookup_free_space_inode(fs_info
->tree_root
, rc
->block_group
,
4001 btrfs_free_path(path
);
4004 ret
= delete_block_group_cache(fs_info
, inode
, 0);
4006 ret
= PTR_ERR(inode
);
4008 if (ret
&& ret
!= -ENOENT
) {
4013 rc
->data_inode
= create_reloc_inode(fs_info
, rc
->block_group
);
4014 if (IS_ERR(rc
->data_inode
)) {
4015 err
= PTR_ERR(rc
->data_inode
);
4016 rc
->data_inode
= NULL
;
4020 printk(KERN_INFO
"btrfs: relocating block group %llu flags %llu\n",
4021 (unsigned long long)rc
->block_group
->key
.objectid
,
4022 (unsigned long long)rc
->block_group
->flags
);
4024 btrfs_start_delalloc_inodes(fs_info
->tree_root
, 0);
4025 btrfs_wait_ordered_extents(fs_info
->tree_root
, 0, 0);
4028 mutex_lock(&fs_info
->cleaner_mutex
);
4030 btrfs_clean_old_snapshots(fs_info
->tree_root
);
4031 ret
= relocate_block_group(rc
);
4033 mutex_unlock(&fs_info
->cleaner_mutex
);
4039 if (rc
->extents_found
== 0)
4042 printk(KERN_INFO
"btrfs: found %llu extents\n",
4043 (unsigned long long)rc
->extents_found
);
4045 if (rc
->stage
== MOVE_DATA_EXTENTS
&& rc
->found_file_extent
) {
4046 btrfs_wait_ordered_range(rc
->data_inode
, 0, (u64
)-1);
4047 invalidate_mapping_pages(rc
->data_inode
->i_mapping
,
4049 rc
->stage
= UPDATE_DATA_PTRS
;
4053 filemap_write_and_wait_range(fs_info
->btree_inode
->i_mapping
,
4054 rc
->block_group
->key
.objectid
,
4055 rc
->block_group
->key
.objectid
+
4056 rc
->block_group
->key
.offset
- 1);
4058 WARN_ON(rc
->block_group
->pinned
> 0);
4059 WARN_ON(rc
->block_group
->reserved
> 0);
4060 WARN_ON(btrfs_block_group_used(&rc
->block_group
->item
) > 0);
4063 btrfs_set_block_group_rw(extent_root
, rc
->block_group
);
4064 iput(rc
->data_inode
);
4065 btrfs_put_block_group(rc
->block_group
);
4070 static noinline_for_stack
int mark_garbage_root(struct btrfs_root
*root
)
4072 struct btrfs_trans_handle
*trans
;
4075 trans
= btrfs_start_transaction(root
->fs_info
->tree_root
, 0);
4076 BUG_ON(IS_ERR(trans
));
4078 memset(&root
->root_item
.drop_progress
, 0,
4079 sizeof(root
->root_item
.drop_progress
));
4080 root
->root_item
.drop_level
= 0;
4081 btrfs_set_root_refs(&root
->root_item
, 0);
4082 ret
= btrfs_update_root(trans
, root
->fs_info
->tree_root
,
4083 &root
->root_key
, &root
->root_item
);
4086 ret
= btrfs_end_transaction(trans
, root
->fs_info
->tree_root
);
4092 * recover relocation interrupted by system crash.
4094 * this function resumes merging reloc trees with corresponding fs trees.
4095 * this is important for keeping the sharing of tree blocks
4097 int btrfs_recover_relocation(struct btrfs_root
*root
)
4099 LIST_HEAD(reloc_roots
);
4100 struct btrfs_key key
;
4101 struct btrfs_root
*fs_root
;
4102 struct btrfs_root
*reloc_root
;
4103 struct btrfs_path
*path
;
4104 struct extent_buffer
*leaf
;
4105 struct reloc_control
*rc
= NULL
;
4106 struct btrfs_trans_handle
*trans
;
4110 path
= btrfs_alloc_path();
4115 key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
4116 key
.type
= BTRFS_ROOT_ITEM_KEY
;
4117 key
.offset
= (u64
)-1;
4120 ret
= btrfs_search_slot(NULL
, root
->fs_info
->tree_root
, &key
,
4127 if (path
->slots
[0] == 0)
4131 leaf
= path
->nodes
[0];
4132 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
4133 btrfs_release_path(path
);
4135 if (key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
||
4136 key
.type
!= BTRFS_ROOT_ITEM_KEY
)
4139 reloc_root
= btrfs_read_fs_root_no_radix(root
, &key
);
4140 if (IS_ERR(reloc_root
)) {
4141 err
= PTR_ERR(reloc_root
);
4145 list_add(&reloc_root
->root_list
, &reloc_roots
);
4147 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
4148 fs_root
= read_fs_root(root
->fs_info
,
4149 reloc_root
->root_key
.offset
);
4150 if (IS_ERR(fs_root
)) {
4151 ret
= PTR_ERR(fs_root
);
4152 if (ret
!= -ENOENT
) {
4156 mark_garbage_root(reloc_root
);
4160 if (key
.offset
== 0)
4165 btrfs_release_path(path
);
4167 if (list_empty(&reloc_roots
))
4170 rc
= alloc_reloc_control();
4176 rc
->extent_root
= root
->fs_info
->extent_root
;
4178 set_reloc_control(rc
);
4180 trans
= btrfs_join_transaction(rc
->extent_root
);
4181 if (IS_ERR(trans
)) {
4182 unset_reloc_control(rc
);
4183 err
= PTR_ERR(trans
);
4187 rc
->merge_reloc_tree
= 1;
4189 while (!list_empty(&reloc_roots
)) {
4190 reloc_root
= list_entry(reloc_roots
.next
,
4191 struct btrfs_root
, root_list
);
4192 list_del(&reloc_root
->root_list
);
4194 if (btrfs_root_refs(&reloc_root
->root_item
) == 0) {
4195 list_add_tail(&reloc_root
->root_list
,
4200 fs_root
= read_fs_root(root
->fs_info
,
4201 reloc_root
->root_key
.offset
);
4202 BUG_ON(IS_ERR(fs_root
));
4204 __add_reloc_root(reloc_root
);
4205 fs_root
->reloc_root
= reloc_root
;
4208 btrfs_commit_transaction(trans
, rc
->extent_root
);
4210 merge_reloc_roots(rc
);
4212 unset_reloc_control(rc
);
4214 trans
= btrfs_join_transaction(rc
->extent_root
);
4216 err
= PTR_ERR(trans
);
4218 btrfs_commit_transaction(trans
, rc
->extent_root
);
4222 while (!list_empty(&reloc_roots
)) {
4223 reloc_root
= list_entry(reloc_roots
.next
,
4224 struct btrfs_root
, root_list
);
4225 list_del(&reloc_root
->root_list
);
4226 free_extent_buffer(reloc_root
->node
);
4227 free_extent_buffer(reloc_root
->commit_root
);
4230 btrfs_free_path(path
);
4233 /* cleanup orphan inode in data relocation tree */
4234 fs_root
= read_fs_root(root
->fs_info
,
4235 BTRFS_DATA_RELOC_TREE_OBJECTID
);
4236 if (IS_ERR(fs_root
))
4237 err
= PTR_ERR(fs_root
);
4239 err
= btrfs_orphan_cleanup(fs_root
);
4245 * helper to add ordered checksum for data relocation.
4247 * cloning checksum properly handles the nodatasum extents.
4248 * it also saves CPU time to re-calculate the checksum.
4250 int btrfs_reloc_clone_csums(struct inode
*inode
, u64 file_pos
, u64 len
)
4252 struct btrfs_ordered_sum
*sums
;
4253 struct btrfs_sector_sum
*sector_sum
;
4254 struct btrfs_ordered_extent
*ordered
;
4255 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
4261 ordered
= btrfs_lookup_ordered_extent(inode
, file_pos
);
4262 BUG_ON(ordered
->file_offset
!= file_pos
|| ordered
->len
!= len
);
4264 disk_bytenr
= file_pos
+ BTRFS_I(inode
)->index_cnt
;
4265 ret
= btrfs_lookup_csums_range(root
->fs_info
->csum_root
, disk_bytenr
,
4266 disk_bytenr
+ len
- 1, &list
, 0);
4268 while (!list_empty(&list
)) {
4269 sums
= list_entry(list
.next
, struct btrfs_ordered_sum
, list
);
4270 list_del_init(&sums
->list
);
4272 sector_sum
= sums
->sums
;
4273 sums
->bytenr
= ordered
->start
;
4276 while (offset
< sums
->len
) {
4277 sector_sum
->bytenr
+= ordered
->start
- disk_bytenr
;
4279 offset
+= root
->sectorsize
;
4282 btrfs_add_ordered_sum(inode
, ordered
, sums
);
4284 btrfs_put_ordered_extent(ordered
);
4288 void btrfs_reloc_cow_block(struct btrfs_trans_handle
*trans
,
4289 struct btrfs_root
*root
, struct extent_buffer
*buf
,
4290 struct extent_buffer
*cow
)
4292 struct reloc_control
*rc
;
4293 struct backref_node
*node
;
4298 rc
= root
->fs_info
->reloc_ctl
;
4302 BUG_ON(rc
->stage
== UPDATE_DATA_PTRS
&&
4303 root
->root_key
.objectid
== BTRFS_DATA_RELOC_TREE_OBJECTID
);
4305 level
= btrfs_header_level(buf
);
4306 if (btrfs_header_generation(buf
) <=
4307 btrfs_root_last_snapshot(&root
->root_item
))
4310 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
&&
4311 rc
->create_reloc_tree
) {
4312 WARN_ON(!first_cow
&& level
== 0);
4314 node
= rc
->backref_cache
.path
[level
];
4315 BUG_ON(node
->bytenr
!= buf
->start
&&
4316 node
->new_bytenr
!= buf
->start
);
4318 drop_node_buffer(node
);
4319 extent_buffer_get(cow
);
4321 node
->new_bytenr
= cow
->start
;
4323 if (!node
->pending
) {
4324 list_move_tail(&node
->list
,
4325 &rc
->backref_cache
.pending
[level
]);
4330 __mark_block_processed(rc
, node
);
4332 if (first_cow
&& level
> 0)
4333 rc
->nodes_relocated
+= buf
->len
;
4336 if (level
== 0 && first_cow
&& rc
->stage
== UPDATE_DATA_PTRS
) {
4337 ret
= replace_file_extents(trans
, rc
, root
, cow
);
4343 * called before creating snapshot. it calculates metadata reservation
4344 * requried for relocating tree blocks in the snapshot
4346 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle
*trans
,
4347 struct btrfs_pending_snapshot
*pending
,
4348 u64
*bytes_to_reserve
)
4350 struct btrfs_root
*root
;
4351 struct reloc_control
*rc
;
4353 root
= pending
->root
;
4354 if (!root
->reloc_root
)
4357 rc
= root
->fs_info
->reloc_ctl
;
4358 if (!rc
->merge_reloc_tree
)
4361 root
= root
->reloc_root
;
4362 BUG_ON(btrfs_root_refs(&root
->root_item
) == 0);
4364 * relocation is in the stage of merging trees. the space
4365 * used by merging a reloc tree is twice the size of
4366 * relocated tree nodes in the worst case. half for cowing
4367 * the reloc tree, half for cowing the fs tree. the space
4368 * used by cowing the reloc tree will be freed after the
4369 * tree is dropped. if we create snapshot, cowing the fs
4370 * tree may use more space than it frees. so we need
4371 * reserve extra space.
4373 *bytes_to_reserve
+= rc
->nodes_relocated
;
4377 * called after snapshot is created. migrate block reservation
4378 * and create reloc root for the newly created snapshot
4380 void btrfs_reloc_post_snapshot(struct btrfs_trans_handle
*trans
,
4381 struct btrfs_pending_snapshot
*pending
)
4383 struct btrfs_root
*root
= pending
->root
;
4384 struct btrfs_root
*reloc_root
;
4385 struct btrfs_root
*new_root
;
4386 struct reloc_control
*rc
;
4389 if (!root
->reloc_root
)
4392 rc
= root
->fs_info
->reloc_ctl
;
4393 rc
->merging_rsv_size
+= rc
->nodes_relocated
;
4395 if (rc
->merge_reloc_tree
) {
4396 ret
= btrfs_block_rsv_migrate(&pending
->block_rsv
,
4398 rc
->nodes_relocated
);
4402 new_root
= pending
->snap
;
4403 reloc_root
= create_reloc_root(trans
, root
->reloc_root
,
4404 new_root
->root_key
.objectid
);
4406 __add_reloc_root(reloc_root
);
4407 new_root
->reloc_root
= reloc_root
;
4409 if (rc
->create_reloc_tree
) {
4410 ret
= clone_backref_node(trans
, rc
, root
, reloc_root
);