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
) {
681 node
= alloc_backref_node(cache
);
687 node
->bytenr
= bytenr
;
694 key
.objectid
= cur
->bytenr
;
695 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
696 key
.offset
= (u64
)-1;
698 path1
->search_commit_root
= 1;
699 path1
->skip_locking
= 1;
700 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path1
,
706 BUG_ON(!ret
|| !path1
->slots
[0]);
710 WARN_ON(cur
->checked
);
711 if (!list_empty(&cur
->upper
)) {
713 * the backref was added previously when processing
714 * backref of type BTRFS_TREE_BLOCK_REF_KEY
716 BUG_ON(!list_is_singular(&cur
->upper
));
717 edge
= list_entry(cur
->upper
.next
, struct backref_edge
,
719 BUG_ON(!list_empty(&edge
->list
[UPPER
]));
720 exist
= edge
->node
[UPPER
];
722 * add the upper level block to pending list if we need
726 list_add_tail(&edge
->list
[UPPER
], &list
);
733 eb
= path1
->nodes
[0];
736 if (path1
->slots
[0] >= btrfs_header_nritems(eb
)) {
737 ret
= btrfs_next_leaf(rc
->extent_root
, path1
);
744 eb
= path1
->nodes
[0];
747 btrfs_item_key_to_cpu(eb
, &key
, path1
->slots
[0]);
748 if (key
.objectid
!= cur
->bytenr
) {
753 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
) {
754 ret
= find_inline_backref(eb
, path1
->slots
[0],
762 /* update key for inline back ref */
763 struct btrfs_extent_inline_ref
*iref
;
764 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
765 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
766 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
767 WARN_ON(key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
&&
768 key
.type
!= BTRFS_SHARED_BLOCK_REF_KEY
);
772 ((key
.type
== BTRFS_TREE_BLOCK_REF_KEY
&&
773 exist
->owner
== key
.offset
) ||
774 (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
&&
775 exist
->bytenr
== key
.offset
))) {
780 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
781 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
||
782 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
783 if (key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
784 struct btrfs_extent_ref_v0
*ref0
;
785 ref0
= btrfs_item_ptr(eb
, path1
->slots
[0],
786 struct btrfs_extent_ref_v0
);
787 if (key
.objectid
== key
.offset
) {
788 root
= find_tree_root(rc
, eb
, ref0
);
789 if (root
&& !should_ignore_root(root
))
792 list_add(&cur
->list
, &useless
);
795 if (is_cowonly_root(btrfs_ref_root_v0(eb
,
800 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
801 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
) {
803 if (key
.objectid
== key
.offset
) {
805 * only root blocks of reloc trees use
806 * backref of this type.
808 root
= find_reloc_root(rc
, cur
->bytenr
);
814 edge
= alloc_backref_edge(cache
);
819 rb_node
= tree_search(&cache
->rb_root
, key
.offset
);
821 upper
= alloc_backref_node(cache
);
823 free_backref_edge(cache
, edge
);
827 upper
->bytenr
= key
.offset
;
828 upper
->level
= cur
->level
+ 1;
830 * backrefs for the upper level block isn't
831 * cached, add the block to pending list
833 list_add_tail(&edge
->list
[UPPER
], &list
);
835 upper
= rb_entry(rb_node
, struct backref_node
,
837 BUG_ON(!upper
->checked
);
838 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
840 list_add_tail(&edge
->list
[LOWER
], &cur
->upper
);
841 edge
->node
[LOWER
] = cur
;
842 edge
->node
[UPPER
] = upper
;
845 } else if (key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
) {
849 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
850 root
= read_fs_root(rc
->extent_root
->fs_info
, key
.offset
);
859 if (btrfs_root_level(&root
->root_item
) == cur
->level
) {
861 BUG_ON(btrfs_root_bytenr(&root
->root_item
) !=
863 if (should_ignore_root(root
))
864 list_add(&cur
->list
, &useless
);
870 level
= cur
->level
+ 1;
873 * searching the tree to find upper level blocks
874 * reference the block.
876 path2
->search_commit_root
= 1;
877 path2
->skip_locking
= 1;
878 path2
->lowest_level
= level
;
879 ret
= btrfs_search_slot(NULL
, root
, node_key
, path2
, 0, 0);
880 path2
->lowest_level
= 0;
885 if (ret
> 0 && path2
->slots
[level
] > 0)
886 path2
->slots
[level
]--;
888 eb
= path2
->nodes
[level
];
889 WARN_ON(btrfs_node_blockptr(eb
, path2
->slots
[level
]) !=
893 for (; level
< BTRFS_MAX_LEVEL
; level
++) {
894 if (!path2
->nodes
[level
]) {
895 BUG_ON(btrfs_root_bytenr(&root
->root_item
) !=
897 if (should_ignore_root(root
))
898 list_add(&lower
->list
, &useless
);
904 edge
= alloc_backref_edge(cache
);
910 eb
= path2
->nodes
[level
];
911 rb_node
= tree_search(&cache
->rb_root
, eb
->start
);
913 upper
= alloc_backref_node(cache
);
915 free_backref_edge(cache
, edge
);
919 upper
->bytenr
= eb
->start
;
920 upper
->owner
= btrfs_header_owner(eb
);
921 upper
->level
= lower
->level
+ 1;
926 * if we know the block isn't shared
927 * we can void checking its backrefs.
929 if (btrfs_block_can_be_shared(root
, eb
))
935 * add the block to pending list if we
936 * need check its backrefs. only block
937 * at 'cur->level + 1' is added to the
938 * tail of pending list. this guarantees
939 * we check backrefs from lower level
940 * blocks to upper level blocks.
942 if (!upper
->checked
&&
943 level
== cur
->level
+ 1) {
944 list_add_tail(&edge
->list
[UPPER
],
947 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
949 upper
= rb_entry(rb_node
, struct backref_node
,
951 BUG_ON(!upper
->checked
);
952 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
954 upper
->owner
= btrfs_header_owner(eb
);
956 list_add_tail(&edge
->list
[LOWER
], &lower
->upper
);
957 edge
->node
[LOWER
] = lower
;
958 edge
->node
[UPPER
] = upper
;
965 btrfs_release_path(path2
);
968 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
978 btrfs_release_path(path1
);
983 /* the pending list isn't empty, take the first block to process */
984 if (!list_empty(&list
)) {
985 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
986 list_del_init(&edge
->list
[UPPER
]);
987 cur
= edge
->node
[UPPER
];
992 * everything goes well, connect backref nodes and insert backref nodes
995 BUG_ON(!node
->checked
);
996 cowonly
= node
->cowonly
;
998 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
,
1001 list_add_tail(&node
->lower
, &cache
->leaves
);
1004 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
])
1005 list_add_tail(&edge
->list
[UPPER
], &list
);
1007 while (!list_empty(&list
)) {
1008 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1009 list_del_init(&edge
->list
[UPPER
]);
1010 upper
= edge
->node
[UPPER
];
1011 if (upper
->detached
) {
1012 list_del(&edge
->list
[LOWER
]);
1013 lower
= edge
->node
[LOWER
];
1014 free_backref_edge(cache
, edge
);
1015 if (list_empty(&lower
->upper
))
1016 list_add(&lower
->list
, &useless
);
1020 if (!RB_EMPTY_NODE(&upper
->rb_node
)) {
1021 if (upper
->lowest
) {
1022 list_del_init(&upper
->lower
);
1026 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1030 BUG_ON(!upper
->checked
);
1031 BUG_ON(cowonly
!= upper
->cowonly
);
1033 rb_node
= tree_insert(&cache
->rb_root
, upper
->bytenr
,
1038 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1040 list_for_each_entry(edge
, &upper
->upper
, list
[LOWER
])
1041 list_add_tail(&edge
->list
[UPPER
], &list
);
1044 * process useless backref nodes. backref nodes for tree leaves
1045 * are deleted from the cache. backref nodes for upper level
1046 * tree blocks are left in the cache to avoid unnecessary backref
1049 while (!list_empty(&useless
)) {
1050 upper
= list_entry(useless
.next
, struct backref_node
, list
);
1051 list_del_init(&upper
->list
);
1052 BUG_ON(!list_empty(&upper
->upper
));
1055 if (upper
->lowest
) {
1056 list_del_init(&upper
->lower
);
1059 while (!list_empty(&upper
->lower
)) {
1060 edge
= list_entry(upper
->lower
.next
,
1061 struct backref_edge
, list
[UPPER
]);
1062 list_del(&edge
->list
[UPPER
]);
1063 list_del(&edge
->list
[LOWER
]);
1064 lower
= edge
->node
[LOWER
];
1065 free_backref_edge(cache
, edge
);
1067 if (list_empty(&lower
->upper
))
1068 list_add(&lower
->list
, &useless
);
1070 __mark_block_processed(rc
, upper
);
1071 if (upper
->level
> 0) {
1072 list_add(&upper
->list
, &cache
->detached
);
1073 upper
->detached
= 1;
1075 rb_erase(&upper
->rb_node
, &cache
->rb_root
);
1076 free_backref_node(cache
, upper
);
1080 btrfs_free_path(path1
);
1081 btrfs_free_path(path2
);
1083 while (!list_empty(&useless
)) {
1084 lower
= list_entry(useless
.next
,
1085 struct backref_node
, upper
);
1086 list_del_init(&lower
->upper
);
1089 INIT_LIST_HEAD(&list
);
1091 if (RB_EMPTY_NODE(&upper
->rb_node
)) {
1092 list_splice_tail(&upper
->upper
, &list
);
1093 free_backref_node(cache
, upper
);
1096 if (list_empty(&list
))
1099 edge
= list_entry(list
.next
, struct backref_edge
,
1101 list_del(&edge
->list
[LOWER
]);
1102 upper
= edge
->node
[UPPER
];
1103 free_backref_edge(cache
, edge
);
1105 return ERR_PTR(err
);
1107 BUG_ON(node
&& node
->detached
);
1112 * helper to add backref node for the newly created snapshot.
1113 * the backref node is created by cloning backref node that
1114 * corresponds to root of source tree
1116 static int clone_backref_node(struct btrfs_trans_handle
*trans
,
1117 struct reloc_control
*rc
,
1118 struct btrfs_root
*src
,
1119 struct btrfs_root
*dest
)
1121 struct btrfs_root
*reloc_root
= src
->reloc_root
;
1122 struct backref_cache
*cache
= &rc
->backref_cache
;
1123 struct backref_node
*node
= NULL
;
1124 struct backref_node
*new_node
;
1125 struct backref_edge
*edge
;
1126 struct backref_edge
*new_edge
;
1127 struct rb_node
*rb_node
;
1129 if (cache
->last_trans
> 0)
1130 update_backref_cache(trans
, cache
);
1132 rb_node
= tree_search(&cache
->rb_root
, src
->commit_root
->start
);
1134 node
= rb_entry(rb_node
, struct backref_node
, rb_node
);
1138 BUG_ON(node
->new_bytenr
!= reloc_root
->node
->start
);
1142 rb_node
= tree_search(&cache
->rb_root
,
1143 reloc_root
->commit_root
->start
);
1145 node
= rb_entry(rb_node
, struct backref_node
,
1147 BUG_ON(node
->detached
);
1154 new_node
= alloc_backref_node(cache
);
1158 new_node
->bytenr
= dest
->node
->start
;
1159 new_node
->level
= node
->level
;
1160 new_node
->lowest
= node
->lowest
;
1161 new_node
->checked
= 1;
1162 new_node
->root
= dest
;
1164 if (!node
->lowest
) {
1165 list_for_each_entry(edge
, &node
->lower
, list
[UPPER
]) {
1166 new_edge
= alloc_backref_edge(cache
);
1170 new_edge
->node
[UPPER
] = new_node
;
1171 new_edge
->node
[LOWER
] = edge
->node
[LOWER
];
1172 list_add_tail(&new_edge
->list
[UPPER
],
1177 rb_node
= tree_insert(&cache
->rb_root
, new_node
->bytenr
,
1178 &new_node
->rb_node
);
1181 if (!new_node
->lowest
) {
1182 list_for_each_entry(new_edge
, &new_node
->lower
, list
[UPPER
]) {
1183 list_add_tail(&new_edge
->list
[LOWER
],
1184 &new_edge
->node
[LOWER
]->upper
);
1189 while (!list_empty(&new_node
->lower
)) {
1190 new_edge
= list_entry(new_node
->lower
.next
,
1191 struct backref_edge
, list
[UPPER
]);
1192 list_del(&new_edge
->list
[UPPER
]);
1193 free_backref_edge(cache
, new_edge
);
1195 free_backref_node(cache
, new_node
);
1200 * helper to add 'address of tree root -> reloc tree' mapping
1202 static int __add_reloc_root(struct btrfs_root
*root
)
1204 struct rb_node
*rb_node
;
1205 struct mapping_node
*node
;
1206 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1208 node
= kmalloc(sizeof(*node
), GFP_NOFS
);
1211 node
->bytenr
= root
->node
->start
;
1214 spin_lock(&rc
->reloc_root_tree
.lock
);
1215 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1216 node
->bytenr
, &node
->rb_node
);
1217 spin_unlock(&rc
->reloc_root_tree
.lock
);
1220 list_add_tail(&root
->root_list
, &rc
->reloc_roots
);
1225 * helper to update/delete the 'address of tree root -> reloc tree'
1228 static int __update_reloc_root(struct btrfs_root
*root
, int del
)
1230 struct rb_node
*rb_node
;
1231 struct mapping_node
*node
= NULL
;
1232 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1234 spin_lock(&rc
->reloc_root_tree
.lock
);
1235 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
,
1236 root
->commit_root
->start
);
1238 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
1239 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
1241 spin_unlock(&rc
->reloc_root_tree
.lock
);
1243 BUG_ON((struct btrfs_root
*)node
->data
!= root
);
1246 spin_lock(&rc
->reloc_root_tree
.lock
);
1247 node
->bytenr
= root
->node
->start
;
1248 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1249 node
->bytenr
, &node
->rb_node
);
1250 spin_unlock(&rc
->reloc_root_tree
.lock
);
1253 list_del_init(&root
->root_list
);
1259 static struct btrfs_root
*create_reloc_root(struct btrfs_trans_handle
*trans
,
1260 struct btrfs_root
*root
, u64 objectid
)
1262 struct btrfs_root
*reloc_root
;
1263 struct extent_buffer
*eb
;
1264 struct btrfs_root_item
*root_item
;
1265 struct btrfs_key root_key
;
1268 root_item
= kmalloc(sizeof(*root_item
), GFP_NOFS
);
1271 root_key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
1272 root_key
.type
= BTRFS_ROOT_ITEM_KEY
;
1273 root_key
.offset
= objectid
;
1275 if (root
->root_key
.objectid
== objectid
) {
1276 /* called by btrfs_init_reloc_root */
1277 ret
= btrfs_copy_root(trans
, root
, root
->commit_root
, &eb
,
1278 BTRFS_TREE_RELOC_OBJECTID
);
1281 btrfs_set_root_last_snapshot(&root
->root_item
,
1282 trans
->transid
- 1);
1285 * called by btrfs_reloc_post_snapshot_hook.
1286 * the source tree is a reloc tree, all tree blocks
1287 * modified after it was created have RELOC flag
1288 * set in their headers. so it's OK to not update
1289 * the 'last_snapshot'.
1291 ret
= btrfs_copy_root(trans
, root
, root
->node
, &eb
,
1292 BTRFS_TREE_RELOC_OBJECTID
);
1296 memcpy(root_item
, &root
->root_item
, sizeof(*root_item
));
1297 btrfs_set_root_bytenr(root_item
, eb
->start
);
1298 btrfs_set_root_level(root_item
, btrfs_header_level(eb
));
1299 btrfs_set_root_generation(root_item
, trans
->transid
);
1301 if (root
->root_key
.objectid
== objectid
) {
1302 btrfs_set_root_refs(root_item
, 0);
1303 memset(&root_item
->drop_progress
, 0,
1304 sizeof(struct btrfs_disk_key
));
1305 root_item
->drop_level
= 0;
1308 btrfs_tree_unlock(eb
);
1309 free_extent_buffer(eb
);
1311 ret
= btrfs_insert_root(trans
, root
->fs_info
->tree_root
,
1312 &root_key
, root_item
);
1316 reloc_root
= btrfs_read_fs_root_no_radix(root
->fs_info
->tree_root
,
1318 BUG_ON(IS_ERR(reloc_root
));
1319 reloc_root
->last_trans
= trans
->transid
;
1324 * create reloc tree for a given fs tree. reloc tree is just a
1325 * snapshot of the fs tree with special root objectid.
1327 int btrfs_init_reloc_root(struct btrfs_trans_handle
*trans
,
1328 struct btrfs_root
*root
)
1330 struct btrfs_root
*reloc_root
;
1331 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1334 if (root
->reloc_root
) {
1335 reloc_root
= root
->reloc_root
;
1336 reloc_root
->last_trans
= trans
->transid
;
1340 if (!rc
|| !rc
->create_reloc_tree
||
1341 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1344 if (!trans
->block_rsv
) {
1345 trans
->block_rsv
= rc
->block_rsv
;
1348 reloc_root
= create_reloc_root(trans
, root
, root
->root_key
.objectid
);
1350 trans
->block_rsv
= NULL
;
1352 __add_reloc_root(reloc_root
);
1353 root
->reloc_root
= reloc_root
;
1358 * update root item of reloc tree
1360 int btrfs_update_reloc_root(struct btrfs_trans_handle
*trans
,
1361 struct btrfs_root
*root
)
1363 struct btrfs_root
*reloc_root
;
1364 struct btrfs_root_item
*root_item
;
1368 if (!root
->reloc_root
)
1371 reloc_root
= root
->reloc_root
;
1372 root_item
= &reloc_root
->root_item
;
1374 if (root
->fs_info
->reloc_ctl
->merge_reloc_tree
&&
1375 btrfs_root_refs(root_item
) == 0) {
1376 root
->reloc_root
= NULL
;
1380 __update_reloc_root(reloc_root
, del
);
1382 if (reloc_root
->commit_root
!= reloc_root
->node
) {
1383 btrfs_set_root_node(root_item
, reloc_root
->node
);
1384 free_extent_buffer(reloc_root
->commit_root
);
1385 reloc_root
->commit_root
= btrfs_root_node(reloc_root
);
1388 ret
= btrfs_update_root(trans
, root
->fs_info
->tree_root
,
1389 &reloc_root
->root_key
, root_item
);
1395 * helper to find first cached inode with inode number >= objectid
1398 static struct inode
*find_next_inode(struct btrfs_root
*root
, u64 objectid
)
1400 struct rb_node
*node
;
1401 struct rb_node
*prev
;
1402 struct btrfs_inode
*entry
;
1403 struct inode
*inode
;
1405 spin_lock(&root
->inode_lock
);
1407 node
= root
->inode_tree
.rb_node
;
1411 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1413 if (objectid
< btrfs_ino(&entry
->vfs_inode
))
1414 node
= node
->rb_left
;
1415 else if (objectid
> btrfs_ino(&entry
->vfs_inode
))
1416 node
= node
->rb_right
;
1422 entry
= rb_entry(prev
, struct btrfs_inode
, rb_node
);
1423 if (objectid
<= btrfs_ino(&entry
->vfs_inode
)) {
1427 prev
= rb_next(prev
);
1431 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1432 inode
= igrab(&entry
->vfs_inode
);
1434 spin_unlock(&root
->inode_lock
);
1438 objectid
= btrfs_ino(&entry
->vfs_inode
) + 1;
1439 if (cond_resched_lock(&root
->inode_lock
))
1442 node
= rb_next(node
);
1444 spin_unlock(&root
->inode_lock
);
1448 static int in_block_group(u64 bytenr
,
1449 struct btrfs_block_group_cache
*block_group
)
1451 if (bytenr
>= block_group
->key
.objectid
&&
1452 bytenr
< block_group
->key
.objectid
+ block_group
->key
.offset
)
1458 * get new location of data
1460 static int get_new_location(struct inode
*reloc_inode
, u64
*new_bytenr
,
1461 u64 bytenr
, u64 num_bytes
)
1463 struct btrfs_root
*root
= BTRFS_I(reloc_inode
)->root
;
1464 struct btrfs_path
*path
;
1465 struct btrfs_file_extent_item
*fi
;
1466 struct extent_buffer
*leaf
;
1469 path
= btrfs_alloc_path();
1473 bytenr
-= BTRFS_I(reloc_inode
)->index_cnt
;
1474 ret
= btrfs_lookup_file_extent(NULL
, root
, path
, btrfs_ino(reloc_inode
),
1483 leaf
= path
->nodes
[0];
1484 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
1485 struct btrfs_file_extent_item
);
1487 BUG_ON(btrfs_file_extent_offset(leaf
, fi
) ||
1488 btrfs_file_extent_compression(leaf
, fi
) ||
1489 btrfs_file_extent_encryption(leaf
, fi
) ||
1490 btrfs_file_extent_other_encoding(leaf
, fi
));
1492 if (num_bytes
!= btrfs_file_extent_disk_num_bytes(leaf
, fi
)) {
1497 *new_bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1500 btrfs_free_path(path
);
1505 * update file extent items in the tree leaf to point to
1506 * the new locations.
1508 static noinline_for_stack
1509 int replace_file_extents(struct btrfs_trans_handle
*trans
,
1510 struct reloc_control
*rc
,
1511 struct btrfs_root
*root
,
1512 struct extent_buffer
*leaf
)
1514 struct btrfs_key key
;
1515 struct btrfs_file_extent_item
*fi
;
1516 struct inode
*inode
= NULL
;
1528 if (rc
->stage
!= UPDATE_DATA_PTRS
)
1531 /* reloc trees always use full backref */
1532 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1533 parent
= leaf
->start
;
1537 nritems
= btrfs_header_nritems(leaf
);
1538 for (i
= 0; i
< nritems
; i
++) {
1540 btrfs_item_key_to_cpu(leaf
, &key
, i
);
1541 if (key
.type
!= BTRFS_EXTENT_DATA_KEY
)
1543 fi
= btrfs_item_ptr(leaf
, i
, struct btrfs_file_extent_item
);
1544 if (btrfs_file_extent_type(leaf
, fi
) ==
1545 BTRFS_FILE_EXTENT_INLINE
)
1547 bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1548 num_bytes
= btrfs_file_extent_disk_num_bytes(leaf
, fi
);
1551 if (!in_block_group(bytenr
, rc
->block_group
))
1555 * if we are modifying block in fs tree, wait for readpage
1556 * to complete and drop the extent cache
1558 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
) {
1560 inode
= find_next_inode(root
, key
.objectid
);
1562 } else if (inode
&& btrfs_ino(inode
) < key
.objectid
) {
1563 btrfs_add_delayed_iput(inode
);
1564 inode
= find_next_inode(root
, key
.objectid
);
1566 if (inode
&& btrfs_ino(inode
) == key
.objectid
) {
1568 btrfs_file_extent_num_bytes(leaf
, fi
);
1569 WARN_ON(!IS_ALIGNED(key
.offset
,
1571 WARN_ON(!IS_ALIGNED(end
, root
->sectorsize
));
1573 ret
= try_lock_extent(&BTRFS_I(inode
)->io_tree
,
1579 btrfs_drop_extent_cache(inode
, key
.offset
, end
,
1581 unlock_extent(&BTRFS_I(inode
)->io_tree
,
1582 key
.offset
, end
, GFP_NOFS
);
1586 ret
= get_new_location(rc
->data_inode
, &new_bytenr
,
1594 btrfs_set_file_extent_disk_bytenr(leaf
, fi
, new_bytenr
);
1597 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
1598 ret
= btrfs_inc_extent_ref(trans
, root
, new_bytenr
,
1600 btrfs_header_owner(leaf
),
1601 key
.objectid
, key
.offset
);
1604 ret
= btrfs_free_extent(trans
, root
, bytenr
, num_bytes
,
1605 parent
, btrfs_header_owner(leaf
),
1606 key
.objectid
, key
.offset
);
1610 btrfs_mark_buffer_dirty(leaf
);
1612 btrfs_add_delayed_iput(inode
);
1616 static noinline_for_stack
1617 int memcmp_node_keys(struct extent_buffer
*eb
, int slot
,
1618 struct btrfs_path
*path
, int level
)
1620 struct btrfs_disk_key key1
;
1621 struct btrfs_disk_key key2
;
1622 btrfs_node_key(eb
, &key1
, slot
);
1623 btrfs_node_key(path
->nodes
[level
], &key2
, path
->slots
[level
]);
1624 return memcmp(&key1
, &key2
, sizeof(key1
));
1628 * try to replace tree blocks in fs tree with the new blocks
1629 * in reloc tree. tree blocks haven't been modified since the
1630 * reloc tree was create can be replaced.
1632 * if a block was replaced, level of the block + 1 is returned.
1633 * if no block got replaced, 0 is returned. if there are other
1634 * errors, a negative error number is returned.
1636 static noinline_for_stack
1637 int replace_path(struct btrfs_trans_handle
*trans
,
1638 struct btrfs_root
*dest
, struct btrfs_root
*src
,
1639 struct btrfs_path
*path
, struct btrfs_key
*next_key
,
1640 int lowest_level
, int max_level
)
1642 struct extent_buffer
*eb
;
1643 struct extent_buffer
*parent
;
1644 struct btrfs_key key
;
1656 BUG_ON(src
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
);
1657 BUG_ON(dest
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
);
1659 last_snapshot
= btrfs_root_last_snapshot(&src
->root_item
);
1661 slot
= path
->slots
[lowest_level
];
1662 btrfs_node_key_to_cpu(path
->nodes
[lowest_level
], &key
, slot
);
1664 eb
= btrfs_lock_root_node(dest
);
1665 btrfs_set_lock_blocking(eb
);
1666 level
= btrfs_header_level(eb
);
1668 if (level
< lowest_level
) {
1669 btrfs_tree_unlock(eb
);
1670 free_extent_buffer(eb
);
1675 ret
= btrfs_cow_block(trans
, dest
, eb
, NULL
, 0, &eb
);
1678 btrfs_set_lock_blocking(eb
);
1681 next_key
->objectid
= (u64
)-1;
1682 next_key
->type
= (u8
)-1;
1683 next_key
->offset
= (u64
)-1;
1688 level
= btrfs_header_level(parent
);
1689 BUG_ON(level
< lowest_level
);
1691 ret
= btrfs_bin_search(parent
, &key
, level
, &slot
);
1692 if (ret
&& slot
> 0)
1695 if (next_key
&& slot
+ 1 < btrfs_header_nritems(parent
))
1696 btrfs_node_key_to_cpu(parent
, next_key
, slot
+ 1);
1698 old_bytenr
= btrfs_node_blockptr(parent
, slot
);
1699 blocksize
= btrfs_level_size(dest
, level
- 1);
1700 old_ptr_gen
= btrfs_node_ptr_generation(parent
, slot
);
1702 if (level
<= max_level
) {
1703 eb
= path
->nodes
[level
];
1704 new_bytenr
= btrfs_node_blockptr(eb
,
1705 path
->slots
[level
]);
1706 new_ptr_gen
= btrfs_node_ptr_generation(eb
,
1707 path
->slots
[level
]);
1713 if (new_bytenr
> 0 && new_bytenr
== old_bytenr
) {
1719 if (new_bytenr
== 0 || old_ptr_gen
> last_snapshot
||
1720 memcmp_node_keys(parent
, slot
, path
, level
)) {
1721 if (level
<= lowest_level
) {
1726 eb
= read_tree_block(dest
, old_bytenr
, blocksize
,
1729 btrfs_tree_lock(eb
);
1731 ret
= btrfs_cow_block(trans
, dest
, eb
, parent
,
1735 btrfs_set_lock_blocking(eb
);
1737 btrfs_tree_unlock(parent
);
1738 free_extent_buffer(parent
);
1745 btrfs_tree_unlock(parent
);
1746 free_extent_buffer(parent
);
1751 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
1752 path
->slots
[level
]);
1753 btrfs_release_path(path
);
1755 path
->lowest_level
= level
;
1756 ret
= btrfs_search_slot(trans
, src
, &key
, path
, 0, 1);
1757 path
->lowest_level
= 0;
1761 * swap blocks in fs tree and reloc tree.
1763 btrfs_set_node_blockptr(parent
, slot
, new_bytenr
);
1764 btrfs_set_node_ptr_generation(parent
, slot
, new_ptr_gen
);
1765 btrfs_mark_buffer_dirty(parent
);
1767 btrfs_set_node_blockptr(path
->nodes
[level
],
1768 path
->slots
[level
], old_bytenr
);
1769 btrfs_set_node_ptr_generation(path
->nodes
[level
],
1770 path
->slots
[level
], old_ptr_gen
);
1771 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
1773 ret
= btrfs_inc_extent_ref(trans
, src
, old_bytenr
, blocksize
,
1774 path
->nodes
[level
]->start
,
1775 src
->root_key
.objectid
, level
- 1, 0);
1777 ret
= btrfs_inc_extent_ref(trans
, dest
, new_bytenr
, blocksize
,
1778 0, dest
->root_key
.objectid
, level
- 1,
1782 ret
= btrfs_free_extent(trans
, src
, new_bytenr
, blocksize
,
1783 path
->nodes
[level
]->start
,
1784 src
->root_key
.objectid
, level
- 1, 0);
1787 ret
= btrfs_free_extent(trans
, dest
, old_bytenr
, blocksize
,
1788 0, dest
->root_key
.objectid
, level
- 1,
1792 btrfs_unlock_up_safe(path
, 0);
1797 btrfs_tree_unlock(parent
);
1798 free_extent_buffer(parent
);
1803 * helper to find next relocated block in reloc tree
1805 static noinline_for_stack
1806 int walk_up_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1809 struct extent_buffer
*eb
;
1814 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1816 for (i
= 0; i
< *level
; i
++) {
1817 free_extent_buffer(path
->nodes
[i
]);
1818 path
->nodes
[i
] = NULL
;
1821 for (i
= *level
; i
< BTRFS_MAX_LEVEL
&& path
->nodes
[i
]; i
++) {
1822 eb
= path
->nodes
[i
];
1823 nritems
= btrfs_header_nritems(eb
);
1824 while (path
->slots
[i
] + 1 < nritems
) {
1826 if (btrfs_node_ptr_generation(eb
, path
->slots
[i
]) <=
1833 free_extent_buffer(path
->nodes
[i
]);
1834 path
->nodes
[i
] = NULL
;
1840 * walk down reloc tree to find relocated block of lowest level
1842 static noinline_for_stack
1843 int walk_down_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1846 struct extent_buffer
*eb
= NULL
;
1854 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1856 for (i
= *level
; i
> 0; i
--) {
1857 eb
= path
->nodes
[i
];
1858 nritems
= btrfs_header_nritems(eb
);
1859 while (path
->slots
[i
] < nritems
) {
1860 ptr_gen
= btrfs_node_ptr_generation(eb
, path
->slots
[i
]);
1861 if (ptr_gen
> last_snapshot
)
1865 if (path
->slots
[i
] >= nritems
) {
1876 bytenr
= btrfs_node_blockptr(eb
, path
->slots
[i
]);
1877 blocksize
= btrfs_level_size(root
, i
- 1);
1878 eb
= read_tree_block(root
, bytenr
, blocksize
, ptr_gen
);
1879 BUG_ON(btrfs_header_level(eb
) != i
- 1);
1880 path
->nodes
[i
- 1] = eb
;
1881 path
->slots
[i
- 1] = 0;
1887 * invalidate extent cache for file extents whose key in range of
1888 * [min_key, max_key)
1890 static int invalidate_extent_cache(struct btrfs_root
*root
,
1891 struct btrfs_key
*min_key
,
1892 struct btrfs_key
*max_key
)
1894 struct inode
*inode
= NULL
;
1899 objectid
= min_key
->objectid
;
1904 if (objectid
> max_key
->objectid
)
1907 inode
= find_next_inode(root
, objectid
);
1910 ino
= btrfs_ino(inode
);
1912 if (ino
> max_key
->objectid
) {
1918 if (!S_ISREG(inode
->i_mode
))
1921 if (unlikely(min_key
->objectid
== ino
)) {
1922 if (min_key
->type
> BTRFS_EXTENT_DATA_KEY
)
1924 if (min_key
->type
< BTRFS_EXTENT_DATA_KEY
)
1927 start
= min_key
->offset
;
1928 WARN_ON(!IS_ALIGNED(start
, root
->sectorsize
));
1934 if (unlikely(max_key
->objectid
== ino
)) {
1935 if (max_key
->type
< BTRFS_EXTENT_DATA_KEY
)
1937 if (max_key
->type
> BTRFS_EXTENT_DATA_KEY
) {
1940 if (max_key
->offset
== 0)
1942 end
= max_key
->offset
;
1943 WARN_ON(!IS_ALIGNED(end
, root
->sectorsize
));
1950 /* the lock_extent waits for readpage to complete */
1951 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
1952 btrfs_drop_extent_cache(inode
, start
, end
, 1);
1953 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
1958 static int find_next_key(struct btrfs_path
*path
, int level
,
1959 struct btrfs_key
*key
)
1962 while (level
< BTRFS_MAX_LEVEL
) {
1963 if (!path
->nodes
[level
])
1965 if (path
->slots
[level
] + 1 <
1966 btrfs_header_nritems(path
->nodes
[level
])) {
1967 btrfs_node_key_to_cpu(path
->nodes
[level
], key
,
1968 path
->slots
[level
] + 1);
1977 * merge the relocated tree blocks in reloc tree with corresponding
1980 static noinline_for_stack
int merge_reloc_root(struct reloc_control
*rc
,
1981 struct btrfs_root
*root
)
1983 LIST_HEAD(inode_list
);
1984 struct btrfs_key key
;
1985 struct btrfs_key next_key
;
1986 struct btrfs_trans_handle
*trans
;
1987 struct btrfs_root
*reloc_root
;
1988 struct btrfs_root_item
*root_item
;
1989 struct btrfs_path
*path
;
1990 struct extent_buffer
*leaf
;
1999 path
= btrfs_alloc_path();
2003 reloc_root
= root
->reloc_root
;
2004 root_item
= &reloc_root
->root_item
;
2006 if (btrfs_disk_key_objectid(&root_item
->drop_progress
) == 0) {
2007 level
= btrfs_root_level(root_item
);
2008 extent_buffer_get(reloc_root
->node
);
2009 path
->nodes
[level
] = reloc_root
->node
;
2010 path
->slots
[level
] = 0;
2012 btrfs_disk_key_to_cpu(&key
, &root_item
->drop_progress
);
2014 level
= root_item
->drop_level
;
2016 path
->lowest_level
= level
;
2017 ret
= btrfs_search_slot(NULL
, reloc_root
, &key
, path
, 0, 0);
2018 path
->lowest_level
= 0;
2020 btrfs_free_path(path
);
2024 btrfs_node_key_to_cpu(path
->nodes
[level
], &next_key
,
2025 path
->slots
[level
]);
2026 WARN_ON(memcmp(&key
, &next_key
, sizeof(key
)));
2028 btrfs_unlock_up_safe(path
, 0);
2031 min_reserved
= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2032 memset(&next_key
, 0, sizeof(next_key
));
2035 trans
= btrfs_start_transaction(root
, 0);
2036 BUG_ON(IS_ERR(trans
));
2037 trans
->block_rsv
= rc
->block_rsv
;
2039 ret
= btrfs_block_rsv_check(trans
, root
, rc
->block_rsv
,
2042 BUG_ON(ret
!= -EAGAIN
);
2043 ret
= btrfs_commit_transaction(trans
, root
);
2051 ret
= walk_down_reloc_tree(reloc_root
, path
, &level
);
2059 if (!find_next_key(path
, level
, &key
) &&
2060 btrfs_comp_cpu_keys(&next_key
, &key
) >= 0) {
2063 ret
= replace_path(trans
, root
, reloc_root
, path
,
2064 &next_key
, level
, max_level
);
2073 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
2074 path
->slots
[level
]);
2078 ret
= walk_up_reloc_tree(reloc_root
, path
, &level
);
2084 * save the merging progress in the drop_progress.
2085 * this is OK since root refs == 1 in this case.
2087 btrfs_node_key(path
->nodes
[level
], &root_item
->drop_progress
,
2088 path
->slots
[level
]);
2089 root_item
->drop_level
= level
;
2091 nr
= trans
->blocks_used
;
2092 btrfs_end_transaction_throttle(trans
, root
);
2094 btrfs_btree_balance_dirty(root
, nr
);
2096 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2097 invalidate_extent_cache(root
, &key
, &next_key
);
2101 * handle the case only one block in the fs tree need to be
2102 * relocated and the block is tree root.
2104 leaf
= btrfs_lock_root_node(root
);
2105 ret
= btrfs_cow_block(trans
, root
, leaf
, NULL
, 0, &leaf
);
2106 btrfs_tree_unlock(leaf
);
2107 free_extent_buffer(leaf
);
2111 btrfs_free_path(path
);
2114 memset(&root_item
->drop_progress
, 0,
2115 sizeof(root_item
->drop_progress
));
2116 root_item
->drop_level
= 0;
2117 btrfs_set_root_refs(root_item
, 0);
2118 btrfs_update_reloc_root(trans
, root
);
2121 nr
= trans
->blocks_used
;
2122 btrfs_end_transaction_throttle(trans
, root
);
2124 btrfs_btree_balance_dirty(root
, nr
);
2126 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2127 invalidate_extent_cache(root
, &key
, &next_key
);
2132 static noinline_for_stack
2133 int prepare_to_merge(struct reloc_control
*rc
, int err
)
2135 struct btrfs_root
*root
= rc
->extent_root
;
2136 struct btrfs_root
*reloc_root
;
2137 struct btrfs_trans_handle
*trans
;
2138 LIST_HEAD(reloc_roots
);
2142 mutex_lock(&root
->fs_info
->trans_mutex
);
2143 rc
->merging_rsv_size
+= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2144 rc
->merging_rsv_size
+= rc
->nodes_relocated
* 2;
2145 mutex_unlock(&root
->fs_info
->trans_mutex
);
2148 num_bytes
= rc
->merging_rsv_size
;
2149 ret
= btrfs_block_rsv_add(NULL
, root
, rc
->block_rsv
,
2155 trans
= btrfs_join_transaction(rc
->extent_root
, 1);
2156 if (IS_ERR(trans
)) {
2158 btrfs_block_rsv_release(rc
->extent_root
,
2159 rc
->block_rsv
, num_bytes
);
2160 return PTR_ERR(trans
);
2164 if (num_bytes
!= rc
->merging_rsv_size
) {
2165 btrfs_end_transaction(trans
, rc
->extent_root
);
2166 btrfs_block_rsv_release(rc
->extent_root
,
2167 rc
->block_rsv
, num_bytes
);
2172 rc
->merge_reloc_tree
= 1;
2174 while (!list_empty(&rc
->reloc_roots
)) {
2175 reloc_root
= list_entry(rc
->reloc_roots
.next
,
2176 struct btrfs_root
, root_list
);
2177 list_del_init(&reloc_root
->root_list
);
2179 root
= read_fs_root(reloc_root
->fs_info
,
2180 reloc_root
->root_key
.offset
);
2181 BUG_ON(IS_ERR(root
));
2182 BUG_ON(root
->reloc_root
!= reloc_root
);
2185 * set reference count to 1, so btrfs_recover_relocation
2186 * knows it should resumes merging
2189 btrfs_set_root_refs(&reloc_root
->root_item
, 1);
2190 btrfs_update_reloc_root(trans
, root
);
2192 list_add(&reloc_root
->root_list
, &reloc_roots
);
2195 list_splice(&reloc_roots
, &rc
->reloc_roots
);
2198 btrfs_commit_transaction(trans
, rc
->extent_root
);
2200 btrfs_end_transaction(trans
, rc
->extent_root
);
2204 static noinline_for_stack
2205 int merge_reloc_roots(struct reloc_control
*rc
)
2207 struct btrfs_root
*root
;
2208 struct btrfs_root
*reloc_root
;
2209 LIST_HEAD(reloc_roots
);
2213 root
= rc
->extent_root
;
2214 mutex_lock(&root
->fs_info
->trans_mutex
);
2215 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
2216 mutex_unlock(&root
->fs_info
->trans_mutex
);
2218 while (!list_empty(&reloc_roots
)) {
2220 reloc_root
= list_entry(reloc_roots
.next
,
2221 struct btrfs_root
, root_list
);
2223 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
2224 root
= read_fs_root(reloc_root
->fs_info
,
2225 reloc_root
->root_key
.offset
);
2226 BUG_ON(IS_ERR(root
));
2227 BUG_ON(root
->reloc_root
!= reloc_root
);
2229 ret
= merge_reloc_root(rc
, root
);
2232 list_del_init(&reloc_root
->root_list
);
2234 btrfs_drop_snapshot(reloc_root
, rc
->block_rsv
, 0);
2241 BUG_ON(!RB_EMPTY_ROOT(&rc
->reloc_root_tree
.rb_root
));
2245 static void free_block_list(struct rb_root
*blocks
)
2247 struct tree_block
*block
;
2248 struct rb_node
*rb_node
;
2249 while ((rb_node
= rb_first(blocks
))) {
2250 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2251 rb_erase(rb_node
, blocks
);
2256 static int record_reloc_root_in_trans(struct btrfs_trans_handle
*trans
,
2257 struct btrfs_root
*reloc_root
)
2259 struct btrfs_root
*root
;
2261 if (reloc_root
->last_trans
== trans
->transid
)
2264 root
= read_fs_root(reloc_root
->fs_info
, reloc_root
->root_key
.offset
);
2265 BUG_ON(IS_ERR(root
));
2266 BUG_ON(root
->reloc_root
!= reloc_root
);
2268 return btrfs_record_root_in_trans(trans
, root
);
2271 static noinline_for_stack
2272 struct btrfs_root
*select_reloc_root(struct btrfs_trans_handle
*trans
,
2273 struct reloc_control
*rc
,
2274 struct backref_node
*node
,
2275 struct backref_edge
*edges
[], int *nr
)
2277 struct backref_node
*next
;
2278 struct btrfs_root
*root
;
2284 next
= walk_up_backref(next
, edges
, &index
);
2287 BUG_ON(!root
->ref_cows
);
2289 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
2290 record_reloc_root_in_trans(trans
, root
);
2294 btrfs_record_root_in_trans(trans
, root
);
2295 root
= root
->reloc_root
;
2297 if (next
->new_bytenr
!= root
->node
->start
) {
2298 BUG_ON(next
->new_bytenr
);
2299 BUG_ON(!list_empty(&next
->list
));
2300 next
->new_bytenr
= root
->node
->start
;
2302 list_add_tail(&next
->list
,
2303 &rc
->backref_cache
.changed
);
2304 __mark_block_processed(rc
, next
);
2310 next
= walk_down_backref(edges
, &index
);
2311 if (!next
|| next
->level
<= node
->level
)
2319 /* setup backref node path for btrfs_reloc_cow_block */
2321 rc
->backref_cache
.path
[next
->level
] = next
;
2324 next
= edges
[index
]->node
[UPPER
];
2330 * select a tree root for relocation. return NULL if the block
2331 * is reference counted. we should use do_relocation() in this
2332 * case. return a tree root pointer if the block isn't reference
2333 * counted. return -ENOENT if the block is root of reloc tree.
2335 static noinline_for_stack
2336 struct btrfs_root
*select_one_root(struct btrfs_trans_handle
*trans
,
2337 struct backref_node
*node
)
2339 struct backref_node
*next
;
2340 struct btrfs_root
*root
;
2341 struct btrfs_root
*fs_root
= NULL
;
2342 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2348 next
= walk_up_backref(next
, edges
, &index
);
2352 /* no other choice for non-references counted tree */
2353 if (!root
->ref_cows
)
2356 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
)
2362 next
= walk_down_backref(edges
, &index
);
2363 if (!next
|| next
->level
<= node
->level
)
2368 return ERR_PTR(-ENOENT
);
2372 static noinline_for_stack
2373 u64
calcu_metadata_size(struct reloc_control
*rc
,
2374 struct backref_node
*node
, int reserve
)
2376 struct backref_node
*next
= node
;
2377 struct backref_edge
*edge
;
2378 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2382 BUG_ON(reserve
&& node
->processed
);
2387 if (next
->processed
&& (reserve
|| next
!= node
))
2390 num_bytes
+= btrfs_level_size(rc
->extent_root
,
2393 if (list_empty(&next
->upper
))
2396 edge
= list_entry(next
->upper
.next
,
2397 struct backref_edge
, list
[LOWER
]);
2398 edges
[index
++] = edge
;
2399 next
= edge
->node
[UPPER
];
2401 next
= walk_down_backref(edges
, &index
);
2406 static int reserve_metadata_space(struct btrfs_trans_handle
*trans
,
2407 struct reloc_control
*rc
,
2408 struct backref_node
*node
)
2410 struct btrfs_root
*root
= rc
->extent_root
;
2414 num_bytes
= calcu_metadata_size(rc
, node
, 1) * 2;
2416 trans
->block_rsv
= rc
->block_rsv
;
2417 ret
= btrfs_block_rsv_add(trans
, root
, rc
->block_rsv
, num_bytes
);
2420 rc
->commit_transaction
= 1;
2427 static void release_metadata_space(struct reloc_control
*rc
,
2428 struct backref_node
*node
)
2430 u64 num_bytes
= calcu_metadata_size(rc
, node
, 0) * 2;
2431 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, num_bytes
);
2435 * relocate a block tree, and then update pointers in upper level
2436 * blocks that reference the block to point to the new location.
2438 * if called by link_to_upper, the block has already been relocated.
2439 * in that case this function just updates pointers.
2441 static int do_relocation(struct btrfs_trans_handle
*trans
,
2442 struct reloc_control
*rc
,
2443 struct backref_node
*node
,
2444 struct btrfs_key
*key
,
2445 struct btrfs_path
*path
, int lowest
)
2447 struct backref_node
*upper
;
2448 struct backref_edge
*edge
;
2449 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2450 struct btrfs_root
*root
;
2451 struct extent_buffer
*eb
;
2460 BUG_ON(lowest
&& node
->eb
);
2462 path
->lowest_level
= node
->level
+ 1;
2463 rc
->backref_cache
.path
[node
->level
] = node
;
2464 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
]) {
2467 upper
= edge
->node
[UPPER
];
2468 root
= select_reloc_root(trans
, rc
, upper
, edges
, &nr
);
2471 if (upper
->eb
&& !upper
->locked
) {
2473 ret
= btrfs_bin_search(upper
->eb
, key
,
2474 upper
->level
, &slot
);
2476 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2477 if (node
->eb
->start
== bytenr
)
2480 drop_node_buffer(upper
);
2484 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2492 upper
->eb
= path
->nodes
[upper
->level
];
2493 path
->nodes
[upper
->level
] = NULL
;
2495 BUG_ON(upper
->eb
!= path
->nodes
[upper
->level
]);
2499 path
->locks
[upper
->level
] = 0;
2501 slot
= path
->slots
[upper
->level
];
2502 btrfs_release_path(path
);
2504 ret
= btrfs_bin_search(upper
->eb
, key
, upper
->level
,
2509 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2511 BUG_ON(bytenr
!= node
->bytenr
);
2513 if (node
->eb
->start
== bytenr
)
2517 blocksize
= btrfs_level_size(root
, node
->level
);
2518 generation
= btrfs_node_ptr_generation(upper
->eb
, slot
);
2519 eb
= read_tree_block(root
, bytenr
, blocksize
, generation
);
2524 btrfs_tree_lock(eb
);
2525 btrfs_set_lock_blocking(eb
);
2528 ret
= btrfs_cow_block(trans
, root
, eb
, upper
->eb
,
2530 btrfs_tree_unlock(eb
);
2531 free_extent_buffer(eb
);
2536 BUG_ON(node
->eb
!= eb
);
2538 btrfs_set_node_blockptr(upper
->eb
, slot
,
2540 btrfs_set_node_ptr_generation(upper
->eb
, slot
,
2542 btrfs_mark_buffer_dirty(upper
->eb
);
2544 ret
= btrfs_inc_extent_ref(trans
, root
,
2545 node
->eb
->start
, blocksize
,
2547 btrfs_header_owner(upper
->eb
),
2551 ret
= btrfs_drop_subtree(trans
, root
, eb
, upper
->eb
);
2555 if (!upper
->pending
)
2556 drop_node_buffer(upper
);
2558 unlock_node_buffer(upper
);
2563 if (!err
&& node
->pending
) {
2564 drop_node_buffer(node
);
2565 list_move_tail(&node
->list
, &rc
->backref_cache
.changed
);
2569 path
->lowest_level
= 0;
2570 BUG_ON(err
== -ENOSPC
);
2574 static int link_to_upper(struct btrfs_trans_handle
*trans
,
2575 struct reloc_control
*rc
,
2576 struct backref_node
*node
,
2577 struct btrfs_path
*path
)
2579 struct btrfs_key key
;
2581 btrfs_node_key_to_cpu(node
->eb
, &key
, 0);
2582 return do_relocation(trans
, rc
, node
, &key
, path
, 0);
2585 static int finish_pending_nodes(struct btrfs_trans_handle
*trans
,
2586 struct reloc_control
*rc
,
2587 struct btrfs_path
*path
, int err
)
2590 struct backref_cache
*cache
= &rc
->backref_cache
;
2591 struct backref_node
*node
;
2595 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
2596 while (!list_empty(&cache
->pending
[level
])) {
2597 node
= list_entry(cache
->pending
[level
].next
,
2598 struct backref_node
, list
);
2599 list_move_tail(&node
->list
, &list
);
2600 BUG_ON(!node
->pending
);
2603 ret
= link_to_upper(trans
, rc
, node
, path
);
2608 list_splice_init(&list
, &cache
->pending
[level
]);
2613 static void mark_block_processed(struct reloc_control
*rc
,
2614 u64 bytenr
, u32 blocksize
)
2616 set_extent_bits(&rc
->processed_blocks
, bytenr
, bytenr
+ blocksize
- 1,
2617 EXTENT_DIRTY
, GFP_NOFS
);
2620 static void __mark_block_processed(struct reloc_control
*rc
,
2621 struct backref_node
*node
)
2624 if (node
->level
== 0 ||
2625 in_block_group(node
->bytenr
, rc
->block_group
)) {
2626 blocksize
= btrfs_level_size(rc
->extent_root
, node
->level
);
2627 mark_block_processed(rc
, node
->bytenr
, blocksize
);
2629 node
->processed
= 1;
2633 * mark a block and all blocks directly/indirectly reference the block
2636 static void update_processed_blocks(struct reloc_control
*rc
,
2637 struct backref_node
*node
)
2639 struct backref_node
*next
= node
;
2640 struct backref_edge
*edge
;
2641 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2647 if (next
->processed
)
2650 __mark_block_processed(rc
, next
);
2652 if (list_empty(&next
->upper
))
2655 edge
= list_entry(next
->upper
.next
,
2656 struct backref_edge
, list
[LOWER
]);
2657 edges
[index
++] = edge
;
2658 next
= edge
->node
[UPPER
];
2660 next
= walk_down_backref(edges
, &index
);
2664 static int tree_block_processed(u64 bytenr
, u32 blocksize
,
2665 struct reloc_control
*rc
)
2667 if (test_range_bit(&rc
->processed_blocks
, bytenr
,
2668 bytenr
+ blocksize
- 1, EXTENT_DIRTY
, 1, NULL
))
2673 static int get_tree_block_key(struct reloc_control
*rc
,
2674 struct tree_block
*block
)
2676 struct extent_buffer
*eb
;
2678 BUG_ON(block
->key_ready
);
2679 eb
= read_tree_block(rc
->extent_root
, block
->bytenr
,
2680 block
->key
.objectid
, block
->key
.offset
);
2682 WARN_ON(btrfs_header_level(eb
) != block
->level
);
2683 if (block
->level
== 0)
2684 btrfs_item_key_to_cpu(eb
, &block
->key
, 0);
2686 btrfs_node_key_to_cpu(eb
, &block
->key
, 0);
2687 free_extent_buffer(eb
);
2688 block
->key_ready
= 1;
2692 static int reada_tree_block(struct reloc_control
*rc
,
2693 struct tree_block
*block
)
2695 BUG_ON(block
->key_ready
);
2696 readahead_tree_block(rc
->extent_root
, block
->bytenr
,
2697 block
->key
.objectid
, block
->key
.offset
);
2702 * helper function to relocate a tree block
2704 static int relocate_tree_block(struct btrfs_trans_handle
*trans
,
2705 struct reloc_control
*rc
,
2706 struct backref_node
*node
,
2707 struct btrfs_key
*key
,
2708 struct btrfs_path
*path
)
2710 struct btrfs_root
*root
;
2717 BUG_ON(node
->processed
);
2718 root
= select_one_root(trans
, node
);
2719 if (root
== ERR_PTR(-ENOENT
)) {
2720 update_processed_blocks(rc
, node
);
2724 if (!root
|| root
->ref_cows
) {
2725 ret
= reserve_metadata_space(trans
, rc
, node
);
2732 if (root
->ref_cows
) {
2733 BUG_ON(node
->new_bytenr
);
2734 BUG_ON(!list_empty(&node
->list
));
2735 btrfs_record_root_in_trans(trans
, root
);
2736 root
= root
->reloc_root
;
2737 node
->new_bytenr
= root
->node
->start
;
2739 list_add_tail(&node
->list
, &rc
->backref_cache
.changed
);
2741 path
->lowest_level
= node
->level
;
2742 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2743 btrfs_release_path(path
);
2748 update_processed_blocks(rc
, node
);
2750 ret
= do_relocation(trans
, rc
, node
, key
, path
, 1);
2753 if (ret
|| node
->level
== 0 || node
->cowonly
) {
2755 release_metadata_space(rc
, node
);
2756 remove_backref_node(&rc
->backref_cache
, node
);
2762 * relocate a list of blocks
2764 static noinline_for_stack
2765 int relocate_tree_blocks(struct btrfs_trans_handle
*trans
,
2766 struct reloc_control
*rc
, struct rb_root
*blocks
)
2768 struct backref_node
*node
;
2769 struct btrfs_path
*path
;
2770 struct tree_block
*block
;
2771 struct rb_node
*rb_node
;
2775 path
= btrfs_alloc_path();
2779 rb_node
= rb_first(blocks
);
2781 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2782 if (!block
->key_ready
)
2783 reada_tree_block(rc
, block
);
2784 rb_node
= rb_next(rb_node
);
2787 rb_node
= rb_first(blocks
);
2789 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2790 if (!block
->key_ready
)
2791 get_tree_block_key(rc
, block
);
2792 rb_node
= rb_next(rb_node
);
2795 rb_node
= rb_first(blocks
);
2797 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2799 node
= build_backref_tree(rc
, &block
->key
,
2800 block
->level
, block
->bytenr
);
2802 err
= PTR_ERR(node
);
2806 ret
= relocate_tree_block(trans
, rc
, node
, &block
->key
,
2809 if (ret
!= -EAGAIN
|| rb_node
== rb_first(blocks
))
2813 rb_node
= rb_next(rb_node
);
2816 free_block_list(blocks
);
2817 err
= finish_pending_nodes(trans
, rc
, path
, err
);
2819 btrfs_free_path(path
);
2823 static noinline_for_stack
2824 int prealloc_file_extent_cluster(struct inode
*inode
,
2825 struct file_extent_cluster
*cluster
)
2830 u64 offset
= BTRFS_I(inode
)->index_cnt
;
2835 BUG_ON(cluster
->start
!= cluster
->boundary
[0]);
2836 mutex_lock(&inode
->i_mutex
);
2838 ret
= btrfs_check_data_free_space(inode
, cluster
->end
+
2839 1 - cluster
->start
);
2843 while (nr
< cluster
->nr
) {
2844 start
= cluster
->boundary
[nr
] - offset
;
2845 if (nr
+ 1 < cluster
->nr
)
2846 end
= cluster
->boundary
[nr
+ 1] - 1 - offset
;
2848 end
= cluster
->end
- offset
;
2850 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2851 num_bytes
= end
+ 1 - start
;
2852 ret
= btrfs_prealloc_file_range(inode
, 0, start
,
2853 num_bytes
, num_bytes
,
2854 end
+ 1, &alloc_hint
);
2855 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2860 btrfs_free_reserved_data_space(inode
, cluster
->end
+
2861 1 - cluster
->start
);
2863 mutex_unlock(&inode
->i_mutex
);
2867 static noinline_for_stack
2868 int setup_extent_mapping(struct inode
*inode
, u64 start
, u64 end
,
2871 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
2872 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2873 struct extent_map
*em
;
2876 em
= alloc_extent_map();
2881 em
->len
= end
+ 1 - start
;
2882 em
->block_len
= em
->len
;
2883 em
->block_start
= block_start
;
2884 em
->bdev
= root
->fs_info
->fs_devices
->latest_bdev
;
2885 set_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
2887 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2889 write_lock(&em_tree
->lock
);
2890 ret
= add_extent_mapping(em_tree
, em
);
2891 write_unlock(&em_tree
->lock
);
2892 if (ret
!= -EEXIST
) {
2893 free_extent_map(em
);
2896 btrfs_drop_extent_cache(inode
, start
, end
, 0);
2898 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2902 static int relocate_file_extent_cluster(struct inode
*inode
,
2903 struct file_extent_cluster
*cluster
)
2907 u64 offset
= BTRFS_I(inode
)->index_cnt
;
2908 unsigned long index
;
2909 unsigned long last_index
;
2911 struct file_ra_state
*ra
;
2918 ra
= kzalloc(sizeof(*ra
), GFP_NOFS
);
2922 ret
= prealloc_file_extent_cluster(inode
, cluster
);
2926 file_ra_state_init(ra
, inode
->i_mapping
);
2928 ret
= setup_extent_mapping(inode
, cluster
->start
- offset
,
2929 cluster
->end
- offset
, cluster
->start
);
2933 index
= (cluster
->start
- offset
) >> PAGE_CACHE_SHIFT
;
2934 last_index
= (cluster
->end
- offset
) >> PAGE_CACHE_SHIFT
;
2935 while (index
<= last_index
) {
2936 ret
= btrfs_delalloc_reserve_metadata(inode
, PAGE_CACHE_SIZE
);
2940 page
= find_lock_page(inode
->i_mapping
, index
);
2942 page_cache_sync_readahead(inode
->i_mapping
,
2944 last_index
+ 1 - index
);
2945 page
= grab_cache_page(inode
->i_mapping
, index
);
2947 btrfs_delalloc_release_metadata(inode
,
2954 if (PageReadahead(page
)) {
2955 page_cache_async_readahead(inode
->i_mapping
,
2956 ra
, NULL
, page
, index
,
2957 last_index
+ 1 - index
);
2960 if (!PageUptodate(page
)) {
2961 btrfs_readpage(NULL
, page
);
2963 if (!PageUptodate(page
)) {
2965 page_cache_release(page
);
2966 btrfs_delalloc_release_metadata(inode
,
2973 page_start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2974 page_end
= page_start
+ PAGE_CACHE_SIZE
- 1;
2976 lock_extent(&BTRFS_I(inode
)->io_tree
,
2977 page_start
, page_end
, GFP_NOFS
);
2979 set_page_extent_mapped(page
);
2981 if (nr
< cluster
->nr
&&
2982 page_start
+ offset
== cluster
->boundary
[nr
]) {
2983 set_extent_bits(&BTRFS_I(inode
)->io_tree
,
2984 page_start
, page_end
,
2985 EXTENT_BOUNDARY
, GFP_NOFS
);
2989 btrfs_set_extent_delalloc(inode
, page_start
, page_end
, NULL
);
2990 set_page_dirty(page
);
2992 unlock_extent(&BTRFS_I(inode
)->io_tree
,
2993 page_start
, page_end
, GFP_NOFS
);
2995 page_cache_release(page
);
2998 balance_dirty_pages_ratelimited(inode
->i_mapping
);
2999 btrfs_throttle(BTRFS_I(inode
)->root
);
3001 WARN_ON(nr
!= cluster
->nr
);
3007 static noinline_for_stack
3008 int relocate_data_extent(struct inode
*inode
, struct btrfs_key
*extent_key
,
3009 struct file_extent_cluster
*cluster
)
3013 if (cluster
->nr
> 0 && extent_key
->objectid
!= cluster
->end
+ 1) {
3014 ret
= relocate_file_extent_cluster(inode
, cluster
);
3021 cluster
->start
= extent_key
->objectid
;
3023 BUG_ON(cluster
->nr
>= MAX_EXTENTS
);
3024 cluster
->end
= extent_key
->objectid
+ extent_key
->offset
- 1;
3025 cluster
->boundary
[cluster
->nr
] = extent_key
->objectid
;
3028 if (cluster
->nr
>= MAX_EXTENTS
) {
3029 ret
= relocate_file_extent_cluster(inode
, cluster
);
3037 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3038 static int get_ref_objectid_v0(struct reloc_control
*rc
,
3039 struct btrfs_path
*path
,
3040 struct btrfs_key
*extent_key
,
3041 u64
*ref_objectid
, int *path_change
)
3043 struct btrfs_key key
;
3044 struct extent_buffer
*leaf
;
3045 struct btrfs_extent_ref_v0
*ref0
;
3049 leaf
= path
->nodes
[0];
3050 slot
= path
->slots
[0];
3052 if (slot
>= btrfs_header_nritems(leaf
)) {
3053 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3057 leaf
= path
->nodes
[0];
3058 slot
= path
->slots
[0];
3062 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
3063 if (key
.objectid
!= extent_key
->objectid
)
3066 if (key
.type
!= BTRFS_EXTENT_REF_V0_KEY
) {
3070 ref0
= btrfs_item_ptr(leaf
, slot
,
3071 struct btrfs_extent_ref_v0
);
3072 *ref_objectid
= btrfs_ref_objectid_v0(leaf
, ref0
);
3080 * helper to add a tree block to the list.
3081 * the major work is getting the generation and level of the block
3083 static int add_tree_block(struct reloc_control
*rc
,
3084 struct btrfs_key
*extent_key
,
3085 struct btrfs_path
*path
,
3086 struct rb_root
*blocks
)
3088 struct extent_buffer
*eb
;
3089 struct btrfs_extent_item
*ei
;
3090 struct btrfs_tree_block_info
*bi
;
3091 struct tree_block
*block
;
3092 struct rb_node
*rb_node
;
3097 eb
= path
->nodes
[0];
3098 item_size
= btrfs_item_size_nr(eb
, path
->slots
[0]);
3100 if (item_size
>= sizeof(*ei
) + sizeof(*bi
)) {
3101 ei
= btrfs_item_ptr(eb
, path
->slots
[0],
3102 struct btrfs_extent_item
);
3103 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
3104 generation
= btrfs_extent_generation(eb
, ei
);
3105 level
= btrfs_tree_block_level(eb
, bi
);
3107 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3111 BUG_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
3112 ret
= get_ref_objectid_v0(rc
, path
, extent_key
,
3116 BUG_ON(ref_owner
>= BTRFS_MAX_LEVEL
);
3117 level
= (int)ref_owner
;
3118 /* FIXME: get real generation */
3125 btrfs_release_path(path
);
3127 BUG_ON(level
== -1);
3129 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3133 block
->bytenr
= extent_key
->objectid
;
3134 block
->key
.objectid
= extent_key
->offset
;
3135 block
->key
.offset
= generation
;
3136 block
->level
= level
;
3137 block
->key_ready
= 0;
3139 rb_node
= tree_insert(blocks
, block
->bytenr
, &block
->rb_node
);
3146 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3148 static int __add_tree_block(struct reloc_control
*rc
,
3149 u64 bytenr
, u32 blocksize
,
3150 struct rb_root
*blocks
)
3152 struct btrfs_path
*path
;
3153 struct btrfs_key key
;
3156 if (tree_block_processed(bytenr
, blocksize
, rc
))
3159 if (tree_search(blocks
, bytenr
))
3162 path
= btrfs_alloc_path();
3166 key
.objectid
= bytenr
;
3167 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3168 key
.offset
= blocksize
;
3170 path
->search_commit_root
= 1;
3171 path
->skip_locking
= 1;
3172 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
, 0, 0);
3177 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, path
->slots
[0]);
3178 ret
= add_tree_block(rc
, &key
, path
, blocks
);
3180 btrfs_free_path(path
);
3185 * helper to check if the block use full backrefs for pointers in it
3187 static int block_use_full_backref(struct reloc_control
*rc
,
3188 struct extent_buffer
*eb
)
3193 if (btrfs_header_flag(eb
, BTRFS_HEADER_FLAG_RELOC
) ||
3194 btrfs_header_backref_rev(eb
) < BTRFS_MIXED_BACKREF_REV
)
3197 ret
= btrfs_lookup_extent_info(NULL
, rc
->extent_root
,
3198 eb
->start
, eb
->len
, NULL
, &flags
);
3201 if (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
)
3208 static int delete_block_group_cache(struct btrfs_fs_info
*fs_info
,
3209 struct inode
*inode
, u64 ino
)
3211 struct btrfs_key key
;
3212 struct btrfs_path
*path
;
3213 struct btrfs_root
*root
= fs_info
->tree_root
;
3214 struct btrfs_trans_handle
*trans
;
3222 key
.type
= BTRFS_INODE_ITEM_KEY
;
3225 inode
= btrfs_iget(fs_info
->sb
, &key
, root
, NULL
);
3226 if (IS_ERR_OR_NULL(inode
) || is_bad_inode(inode
)) {
3227 if (inode
&& !IS_ERR(inode
))
3233 path
= btrfs_alloc_path();
3239 trans
= btrfs_join_transaction(root
, 0);
3240 if (IS_ERR(trans
)) {
3241 btrfs_free_path(path
);
3242 ret
= PTR_ERR(trans
);
3246 ret
= btrfs_truncate_free_space_cache(root
, trans
, path
, inode
);
3248 btrfs_free_path(path
);
3249 nr
= trans
->blocks_used
;
3250 btrfs_end_transaction(trans
, root
);
3251 btrfs_btree_balance_dirty(root
, nr
);
3258 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3259 * this function scans fs tree to find blocks reference the data extent
3261 static int find_data_references(struct reloc_control
*rc
,
3262 struct btrfs_key
*extent_key
,
3263 struct extent_buffer
*leaf
,
3264 struct btrfs_extent_data_ref
*ref
,
3265 struct rb_root
*blocks
)
3267 struct btrfs_path
*path
;
3268 struct tree_block
*block
;
3269 struct btrfs_root
*root
;
3270 struct btrfs_file_extent_item
*fi
;
3271 struct rb_node
*rb_node
;
3272 struct btrfs_key key
;
3283 ref_root
= btrfs_extent_data_ref_root(leaf
, ref
);
3284 ref_objectid
= btrfs_extent_data_ref_objectid(leaf
, ref
);
3285 ref_offset
= btrfs_extent_data_ref_offset(leaf
, ref
);
3286 ref_count
= btrfs_extent_data_ref_count(leaf
, ref
);
3289 * This is an extent belonging to the free space cache, lets just delete
3290 * it and redo the search.
3292 if (ref_root
== BTRFS_ROOT_TREE_OBJECTID
) {
3293 ret
= delete_block_group_cache(rc
->extent_root
->fs_info
,
3294 NULL
, ref_objectid
);
3300 path
= btrfs_alloc_path();
3304 root
= read_fs_root(rc
->extent_root
->fs_info
, ref_root
);
3306 err
= PTR_ERR(root
);
3310 key
.objectid
= ref_objectid
;
3311 key
.offset
= ref_offset
;
3312 key
.type
= BTRFS_EXTENT_DATA_KEY
;
3314 path
->search_commit_root
= 1;
3315 path
->skip_locking
= 1;
3316 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
3322 leaf
= path
->nodes
[0];
3323 nritems
= btrfs_header_nritems(leaf
);
3325 * the references in tree blocks that use full backrefs
3326 * are not counted in
3328 if (block_use_full_backref(rc
, leaf
))
3332 rb_node
= tree_search(blocks
, leaf
->start
);
3337 path
->slots
[0] = nritems
;
3340 while (ref_count
> 0) {
3341 while (path
->slots
[0] >= nritems
) {
3342 ret
= btrfs_next_leaf(root
, path
);
3352 leaf
= path
->nodes
[0];
3353 nritems
= btrfs_header_nritems(leaf
);
3356 if (block_use_full_backref(rc
, leaf
))
3360 rb_node
= tree_search(blocks
, leaf
->start
);
3365 path
->slots
[0] = nritems
;
3369 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3370 if (key
.objectid
!= ref_objectid
||
3371 key
.type
!= BTRFS_EXTENT_DATA_KEY
) {
3376 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3377 struct btrfs_file_extent_item
);
3379 if (btrfs_file_extent_type(leaf
, fi
) ==
3380 BTRFS_FILE_EXTENT_INLINE
)
3383 if (btrfs_file_extent_disk_bytenr(leaf
, fi
) !=
3384 extent_key
->objectid
)
3387 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
3388 if (key
.offset
!= ref_offset
)
3396 if (!tree_block_processed(leaf
->start
, leaf
->len
, rc
)) {
3397 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3402 block
->bytenr
= leaf
->start
;
3403 btrfs_item_key_to_cpu(leaf
, &block
->key
, 0);
3405 block
->key_ready
= 1;
3406 rb_node
= tree_insert(blocks
, block
->bytenr
,
3413 path
->slots
[0] = nritems
;
3419 btrfs_free_path(path
);
3424 * hepler to find all tree blocks that reference a given data extent
3426 static noinline_for_stack
3427 int add_data_references(struct reloc_control
*rc
,
3428 struct btrfs_key
*extent_key
,
3429 struct btrfs_path
*path
,
3430 struct rb_root
*blocks
)
3432 struct btrfs_key key
;
3433 struct extent_buffer
*eb
;
3434 struct btrfs_extent_data_ref
*dref
;
3435 struct btrfs_extent_inline_ref
*iref
;
3438 u32 blocksize
= btrfs_level_size(rc
->extent_root
, 0);
3442 eb
= path
->nodes
[0];
3443 ptr
= btrfs_item_ptr_offset(eb
, path
->slots
[0]);
3444 end
= ptr
+ btrfs_item_size_nr(eb
, path
->slots
[0]);
3445 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3446 if (ptr
+ sizeof(struct btrfs_extent_item_v0
) == end
)
3450 ptr
+= sizeof(struct btrfs_extent_item
);
3453 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
3454 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
3455 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3456 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
3457 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3459 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3460 dref
= (struct btrfs_extent_data_ref
*)(&iref
->offset
);
3461 ret
= find_data_references(rc
, extent_key
,
3466 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
3472 eb
= path
->nodes
[0];
3473 if (path
->slots
[0] >= btrfs_header_nritems(eb
)) {
3474 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3481 eb
= path
->nodes
[0];
3484 btrfs_item_key_to_cpu(eb
, &key
, path
->slots
[0]);
3485 if (key
.objectid
!= extent_key
->objectid
)
3488 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3489 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
||
3490 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
3492 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
3493 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3495 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3497 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3498 dref
= btrfs_item_ptr(eb
, path
->slots
[0],
3499 struct btrfs_extent_data_ref
);
3500 ret
= find_data_references(rc
, extent_key
,
3511 btrfs_release_path(path
);
3513 free_block_list(blocks
);
3518 * hepler to find next unprocessed extent
3520 static noinline_for_stack
3521 int find_next_extent(struct btrfs_trans_handle
*trans
,
3522 struct reloc_control
*rc
, struct btrfs_path
*path
,
3523 struct btrfs_key
*extent_key
)
3525 struct btrfs_key key
;
3526 struct extent_buffer
*leaf
;
3527 u64 start
, end
, last
;
3530 last
= rc
->block_group
->key
.objectid
+ rc
->block_group
->key
.offset
;
3533 if (rc
->search_start
>= last
) {
3538 key
.objectid
= rc
->search_start
;
3539 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3542 path
->search_commit_root
= 1;
3543 path
->skip_locking
= 1;
3544 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
,
3549 leaf
= path
->nodes
[0];
3550 if (path
->slots
[0] >= btrfs_header_nritems(leaf
)) {
3551 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3554 leaf
= path
->nodes
[0];
3557 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3558 if (key
.objectid
>= last
) {
3563 if (key
.type
!= BTRFS_EXTENT_ITEM_KEY
||
3564 key
.objectid
+ key
.offset
<= rc
->search_start
) {
3569 ret
= find_first_extent_bit(&rc
->processed_blocks
,
3570 key
.objectid
, &start
, &end
,
3573 if (ret
== 0 && start
<= key
.objectid
) {
3574 btrfs_release_path(path
);
3575 rc
->search_start
= end
+ 1;
3577 rc
->search_start
= key
.objectid
+ key
.offset
;
3578 memcpy(extent_key
, &key
, sizeof(key
));
3582 btrfs_release_path(path
);
3586 static void set_reloc_control(struct reloc_control
*rc
)
3588 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3589 mutex_lock(&fs_info
->trans_mutex
);
3590 fs_info
->reloc_ctl
= rc
;
3591 mutex_unlock(&fs_info
->trans_mutex
);
3594 static void unset_reloc_control(struct reloc_control
*rc
)
3596 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3597 mutex_lock(&fs_info
->trans_mutex
);
3598 fs_info
->reloc_ctl
= NULL
;
3599 mutex_unlock(&fs_info
->trans_mutex
);
3602 static int check_extent_flags(u64 flags
)
3604 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3605 (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3607 if (!(flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3608 !(flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3610 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3611 (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
))
3616 static noinline_for_stack
3617 int prepare_to_relocate(struct reloc_control
*rc
)
3619 struct btrfs_trans_handle
*trans
;
3622 rc
->block_rsv
= btrfs_alloc_block_rsv(rc
->extent_root
);
3627 * reserve some space for creating reloc trees.
3628 * btrfs_init_reloc_root will use them when there
3629 * is no reservation in transaction handle.
3631 ret
= btrfs_block_rsv_add(NULL
, rc
->extent_root
, rc
->block_rsv
,
3632 rc
->extent_root
->nodesize
* 256);
3636 rc
->block_rsv
->refill_used
= 1;
3637 btrfs_add_durable_block_rsv(rc
->extent_root
->fs_info
, rc
->block_rsv
);
3639 memset(&rc
->cluster
, 0, sizeof(rc
->cluster
));
3640 rc
->search_start
= rc
->block_group
->key
.objectid
;
3641 rc
->extents_found
= 0;
3642 rc
->nodes_relocated
= 0;
3643 rc
->merging_rsv_size
= 0;
3645 rc
->create_reloc_tree
= 1;
3646 set_reloc_control(rc
);
3648 trans
= btrfs_join_transaction(rc
->extent_root
, 1);
3649 BUG_ON(IS_ERR(trans
));
3650 btrfs_commit_transaction(trans
, rc
->extent_root
);
3654 static noinline_for_stack
int relocate_block_group(struct reloc_control
*rc
)
3656 struct rb_root blocks
= RB_ROOT
;
3657 struct btrfs_key key
;
3658 struct btrfs_trans_handle
*trans
= NULL
;
3659 struct btrfs_path
*path
;
3660 struct btrfs_extent_item
*ei
;
3668 path
= btrfs_alloc_path();
3672 ret
= prepare_to_relocate(rc
);
3680 trans
= btrfs_start_transaction(rc
->extent_root
, 0);
3681 BUG_ON(IS_ERR(trans
));
3683 if (update_backref_cache(trans
, &rc
->backref_cache
)) {
3684 btrfs_end_transaction(trans
, rc
->extent_root
);
3688 ret
= find_next_extent(trans
, rc
, path
, &key
);
3694 rc
->extents_found
++;
3696 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
3697 struct btrfs_extent_item
);
3698 item_size
= btrfs_item_size_nr(path
->nodes
[0], path
->slots
[0]);
3699 if (item_size
>= sizeof(*ei
)) {
3700 flags
= btrfs_extent_flags(path
->nodes
[0], ei
);
3701 ret
= check_extent_flags(flags
);
3705 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3707 int path_change
= 0;
3710 sizeof(struct btrfs_extent_item_v0
));
3711 ret
= get_ref_objectid_v0(rc
, path
, &key
, &ref_owner
,
3713 if (ref_owner
< BTRFS_FIRST_FREE_OBJECTID
)
3714 flags
= BTRFS_EXTENT_FLAG_TREE_BLOCK
;
3716 flags
= BTRFS_EXTENT_FLAG_DATA
;
3719 btrfs_release_path(path
);
3721 path
->search_commit_root
= 1;
3722 path
->skip_locking
= 1;
3723 ret
= btrfs_search_slot(NULL
, rc
->extent_root
,
3736 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
3737 ret
= add_tree_block(rc
, &key
, path
, &blocks
);
3738 } else if (rc
->stage
== UPDATE_DATA_PTRS
&&
3739 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
3740 ret
= add_data_references(rc
, &key
, path
, &blocks
);
3742 btrfs_release_path(path
);
3750 if (!RB_EMPTY_ROOT(&blocks
)) {
3751 ret
= relocate_tree_blocks(trans
, rc
, &blocks
);
3753 if (ret
!= -EAGAIN
) {
3757 rc
->extents_found
--;
3758 rc
->search_start
= key
.objectid
;
3762 ret
= btrfs_block_rsv_check(trans
, rc
->extent_root
,
3763 rc
->block_rsv
, 0, 5);
3765 if (ret
!= -EAGAIN
) {
3770 rc
->commit_transaction
= 1;
3773 if (rc
->commit_transaction
) {
3774 rc
->commit_transaction
= 0;
3775 ret
= btrfs_commit_transaction(trans
, rc
->extent_root
);
3778 nr
= trans
->blocks_used
;
3779 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
3780 btrfs_btree_balance_dirty(rc
->extent_root
, nr
);
3784 if (rc
->stage
== MOVE_DATA_EXTENTS
&&
3785 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
3786 rc
->found_file_extent
= 1;
3787 ret
= relocate_data_extent(rc
->data_inode
,
3788 &key
, &rc
->cluster
);
3795 if (trans
&& progress
&& err
== -ENOSPC
) {
3796 ret
= btrfs_force_chunk_alloc(trans
, rc
->extent_root
,
3797 rc
->block_group
->flags
);
3805 btrfs_release_path(path
);
3806 clear_extent_bits(&rc
->processed_blocks
, 0, (u64
)-1, EXTENT_DIRTY
,
3810 nr
= trans
->blocks_used
;
3811 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
3812 btrfs_btree_balance_dirty(rc
->extent_root
, nr
);
3816 ret
= relocate_file_extent_cluster(rc
->data_inode
,
3822 rc
->create_reloc_tree
= 0;
3823 set_reloc_control(rc
);
3825 backref_cache_cleanup(&rc
->backref_cache
);
3826 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
3828 err
= prepare_to_merge(rc
, err
);
3830 merge_reloc_roots(rc
);
3832 rc
->merge_reloc_tree
= 0;
3833 unset_reloc_control(rc
);
3834 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
3836 /* get rid of pinned extents */
3837 trans
= btrfs_join_transaction(rc
->extent_root
, 1);
3839 err
= PTR_ERR(trans
);
3841 btrfs_commit_transaction(trans
, rc
->extent_root
);
3843 btrfs_free_block_rsv(rc
->extent_root
, rc
->block_rsv
);
3844 btrfs_free_path(path
);
3848 static int __insert_orphan_inode(struct btrfs_trans_handle
*trans
,
3849 struct btrfs_root
*root
, u64 objectid
)
3851 struct btrfs_path
*path
;
3852 struct btrfs_inode_item
*item
;
3853 struct extent_buffer
*leaf
;
3856 path
= btrfs_alloc_path();
3860 ret
= btrfs_insert_empty_inode(trans
, root
, path
, objectid
);
3864 leaf
= path
->nodes
[0];
3865 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_inode_item
);
3866 memset_extent_buffer(leaf
, 0, (unsigned long)item
, sizeof(*item
));
3867 btrfs_set_inode_generation(leaf
, item
, 1);
3868 btrfs_set_inode_size(leaf
, item
, 0);
3869 btrfs_set_inode_mode(leaf
, item
, S_IFREG
| 0600);
3870 btrfs_set_inode_flags(leaf
, item
, BTRFS_INODE_NOCOMPRESS
|
3871 BTRFS_INODE_PREALLOC
);
3872 btrfs_mark_buffer_dirty(leaf
);
3873 btrfs_release_path(path
);
3875 btrfs_free_path(path
);
3880 * helper to create inode for data relocation.
3881 * the inode is in data relocation tree and its link count is 0
3883 static noinline_for_stack
3884 struct inode
*create_reloc_inode(struct btrfs_fs_info
*fs_info
,
3885 struct btrfs_block_group_cache
*group
)
3887 struct inode
*inode
= NULL
;
3888 struct btrfs_trans_handle
*trans
;
3889 struct btrfs_root
*root
;
3890 struct btrfs_key key
;
3892 u64 objectid
= BTRFS_FIRST_FREE_OBJECTID
;
3895 root
= read_fs_root(fs_info
, BTRFS_DATA_RELOC_TREE_OBJECTID
);
3897 return ERR_CAST(root
);
3899 trans
= btrfs_start_transaction(root
, 6);
3901 return ERR_CAST(trans
);
3903 err
= btrfs_find_free_objectid(root
, &objectid
);
3907 err
= __insert_orphan_inode(trans
, root
, objectid
);
3910 key
.objectid
= objectid
;
3911 key
.type
= BTRFS_INODE_ITEM_KEY
;
3913 inode
= btrfs_iget(root
->fs_info
->sb
, &key
, root
, NULL
);
3914 BUG_ON(IS_ERR(inode
) || is_bad_inode(inode
));
3915 BTRFS_I(inode
)->index_cnt
= group
->key
.objectid
;
3917 err
= btrfs_orphan_add(trans
, inode
);
3919 nr
= trans
->blocks_used
;
3920 btrfs_end_transaction(trans
, root
);
3921 btrfs_btree_balance_dirty(root
, nr
);
3925 inode
= ERR_PTR(err
);
3930 static struct reloc_control
*alloc_reloc_control(void)
3932 struct reloc_control
*rc
;
3934 rc
= kzalloc(sizeof(*rc
), GFP_NOFS
);
3938 INIT_LIST_HEAD(&rc
->reloc_roots
);
3939 backref_cache_init(&rc
->backref_cache
);
3940 mapping_tree_init(&rc
->reloc_root_tree
);
3941 extent_io_tree_init(&rc
->processed_blocks
, NULL
);
3946 * function to relocate all extents in a block group.
3948 int btrfs_relocate_block_group(struct btrfs_root
*extent_root
, u64 group_start
)
3950 struct btrfs_fs_info
*fs_info
= extent_root
->fs_info
;
3951 struct reloc_control
*rc
;
3952 struct inode
*inode
;
3953 struct btrfs_path
*path
;
3958 rc
= alloc_reloc_control();
3962 rc
->extent_root
= extent_root
;
3964 rc
->block_group
= btrfs_lookup_block_group(fs_info
, group_start
);
3965 BUG_ON(!rc
->block_group
);
3967 if (!rc
->block_group
->ro
) {
3968 ret
= btrfs_set_block_group_ro(extent_root
, rc
->block_group
);
3976 path
= btrfs_alloc_path();
3982 inode
= lookup_free_space_inode(fs_info
->tree_root
, rc
->block_group
,
3984 btrfs_free_path(path
);
3987 ret
= delete_block_group_cache(fs_info
, inode
, 0);
3989 ret
= PTR_ERR(inode
);
3991 if (ret
&& ret
!= -ENOENT
) {
3996 rc
->data_inode
= create_reloc_inode(fs_info
, rc
->block_group
);
3997 if (IS_ERR(rc
->data_inode
)) {
3998 err
= PTR_ERR(rc
->data_inode
);
3999 rc
->data_inode
= NULL
;
4003 printk(KERN_INFO
"btrfs: relocating block group %llu flags %llu\n",
4004 (unsigned long long)rc
->block_group
->key
.objectid
,
4005 (unsigned long long)rc
->block_group
->flags
);
4007 btrfs_start_delalloc_inodes(fs_info
->tree_root
, 0);
4008 btrfs_wait_ordered_extents(fs_info
->tree_root
, 0, 0);
4011 mutex_lock(&fs_info
->cleaner_mutex
);
4013 btrfs_clean_old_snapshots(fs_info
->tree_root
);
4014 ret
= relocate_block_group(rc
);
4016 mutex_unlock(&fs_info
->cleaner_mutex
);
4022 if (rc
->extents_found
== 0)
4025 printk(KERN_INFO
"btrfs: found %llu extents\n",
4026 (unsigned long long)rc
->extents_found
);
4028 if (rc
->stage
== MOVE_DATA_EXTENTS
&& rc
->found_file_extent
) {
4029 btrfs_wait_ordered_range(rc
->data_inode
, 0, (u64
)-1);
4030 invalidate_mapping_pages(rc
->data_inode
->i_mapping
,
4032 rc
->stage
= UPDATE_DATA_PTRS
;
4036 filemap_write_and_wait_range(fs_info
->btree_inode
->i_mapping
,
4037 rc
->block_group
->key
.objectid
,
4038 rc
->block_group
->key
.objectid
+
4039 rc
->block_group
->key
.offset
- 1);
4041 WARN_ON(rc
->block_group
->pinned
> 0);
4042 WARN_ON(rc
->block_group
->reserved
> 0);
4043 WARN_ON(btrfs_block_group_used(&rc
->block_group
->item
) > 0);
4046 btrfs_set_block_group_rw(extent_root
, rc
->block_group
);
4047 iput(rc
->data_inode
);
4048 btrfs_put_block_group(rc
->block_group
);
4053 static noinline_for_stack
int mark_garbage_root(struct btrfs_root
*root
)
4055 struct btrfs_trans_handle
*trans
;
4058 trans
= btrfs_start_transaction(root
->fs_info
->tree_root
, 0);
4059 BUG_ON(IS_ERR(trans
));
4061 memset(&root
->root_item
.drop_progress
, 0,
4062 sizeof(root
->root_item
.drop_progress
));
4063 root
->root_item
.drop_level
= 0;
4064 btrfs_set_root_refs(&root
->root_item
, 0);
4065 ret
= btrfs_update_root(trans
, root
->fs_info
->tree_root
,
4066 &root
->root_key
, &root
->root_item
);
4069 ret
= btrfs_end_transaction(trans
, root
->fs_info
->tree_root
);
4075 * recover relocation interrupted by system crash.
4077 * this function resumes merging reloc trees with corresponding fs trees.
4078 * this is important for keeping the sharing of tree blocks
4080 int btrfs_recover_relocation(struct btrfs_root
*root
)
4082 LIST_HEAD(reloc_roots
);
4083 struct btrfs_key key
;
4084 struct btrfs_root
*fs_root
;
4085 struct btrfs_root
*reloc_root
;
4086 struct btrfs_path
*path
;
4087 struct extent_buffer
*leaf
;
4088 struct reloc_control
*rc
= NULL
;
4089 struct btrfs_trans_handle
*trans
;
4093 path
= btrfs_alloc_path();
4097 key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
4098 key
.type
= BTRFS_ROOT_ITEM_KEY
;
4099 key
.offset
= (u64
)-1;
4102 ret
= btrfs_search_slot(NULL
, root
->fs_info
->tree_root
, &key
,
4109 if (path
->slots
[0] == 0)
4113 leaf
= path
->nodes
[0];
4114 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
4115 btrfs_release_path(path
);
4117 if (key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
||
4118 key
.type
!= BTRFS_ROOT_ITEM_KEY
)
4121 reloc_root
= btrfs_read_fs_root_no_radix(root
, &key
);
4122 if (IS_ERR(reloc_root
)) {
4123 err
= PTR_ERR(reloc_root
);
4127 list_add(&reloc_root
->root_list
, &reloc_roots
);
4129 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
4130 fs_root
= read_fs_root(root
->fs_info
,
4131 reloc_root
->root_key
.offset
);
4132 if (IS_ERR(fs_root
)) {
4133 ret
= PTR_ERR(fs_root
);
4134 if (ret
!= -ENOENT
) {
4138 mark_garbage_root(reloc_root
);
4142 if (key
.offset
== 0)
4147 btrfs_release_path(path
);
4149 if (list_empty(&reloc_roots
))
4152 rc
= alloc_reloc_control();
4158 rc
->extent_root
= root
->fs_info
->extent_root
;
4160 set_reloc_control(rc
);
4162 trans
= btrfs_join_transaction(rc
->extent_root
, 1);
4163 if (IS_ERR(trans
)) {
4164 unset_reloc_control(rc
);
4165 err
= PTR_ERR(trans
);
4169 rc
->merge_reloc_tree
= 1;
4171 while (!list_empty(&reloc_roots
)) {
4172 reloc_root
= list_entry(reloc_roots
.next
,
4173 struct btrfs_root
, root_list
);
4174 list_del(&reloc_root
->root_list
);
4176 if (btrfs_root_refs(&reloc_root
->root_item
) == 0) {
4177 list_add_tail(&reloc_root
->root_list
,
4182 fs_root
= read_fs_root(root
->fs_info
,
4183 reloc_root
->root_key
.offset
);
4184 BUG_ON(IS_ERR(fs_root
));
4186 __add_reloc_root(reloc_root
);
4187 fs_root
->reloc_root
= reloc_root
;
4190 btrfs_commit_transaction(trans
, rc
->extent_root
);
4192 merge_reloc_roots(rc
);
4194 unset_reloc_control(rc
);
4196 trans
= btrfs_join_transaction(rc
->extent_root
, 1);
4198 err
= PTR_ERR(trans
);
4200 btrfs_commit_transaction(trans
, rc
->extent_root
);
4204 while (!list_empty(&reloc_roots
)) {
4205 reloc_root
= list_entry(reloc_roots
.next
,
4206 struct btrfs_root
, root_list
);
4207 list_del(&reloc_root
->root_list
);
4208 free_extent_buffer(reloc_root
->node
);
4209 free_extent_buffer(reloc_root
->commit_root
);
4212 btrfs_free_path(path
);
4215 /* cleanup orphan inode in data relocation tree */
4216 fs_root
= read_fs_root(root
->fs_info
,
4217 BTRFS_DATA_RELOC_TREE_OBJECTID
);
4218 if (IS_ERR(fs_root
))
4219 err
= PTR_ERR(fs_root
);
4221 err
= btrfs_orphan_cleanup(fs_root
);
4227 * helper to add ordered checksum for data relocation.
4229 * cloning checksum properly handles the nodatasum extents.
4230 * it also saves CPU time to re-calculate the checksum.
4232 int btrfs_reloc_clone_csums(struct inode
*inode
, u64 file_pos
, u64 len
)
4234 struct btrfs_ordered_sum
*sums
;
4235 struct btrfs_sector_sum
*sector_sum
;
4236 struct btrfs_ordered_extent
*ordered
;
4237 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
4243 ordered
= btrfs_lookup_ordered_extent(inode
, file_pos
);
4244 BUG_ON(ordered
->file_offset
!= file_pos
|| ordered
->len
!= len
);
4246 disk_bytenr
= file_pos
+ BTRFS_I(inode
)->index_cnt
;
4247 ret
= btrfs_lookup_csums_range(root
->fs_info
->csum_root
, disk_bytenr
,
4248 disk_bytenr
+ len
- 1, &list
, 0);
4250 while (!list_empty(&list
)) {
4251 sums
= list_entry(list
.next
, struct btrfs_ordered_sum
, list
);
4252 list_del_init(&sums
->list
);
4254 sector_sum
= sums
->sums
;
4255 sums
->bytenr
= ordered
->start
;
4258 while (offset
< sums
->len
) {
4259 sector_sum
->bytenr
+= ordered
->start
- disk_bytenr
;
4261 offset
+= root
->sectorsize
;
4264 btrfs_add_ordered_sum(inode
, ordered
, sums
);
4266 btrfs_put_ordered_extent(ordered
);
4270 void btrfs_reloc_cow_block(struct btrfs_trans_handle
*trans
,
4271 struct btrfs_root
*root
, struct extent_buffer
*buf
,
4272 struct extent_buffer
*cow
)
4274 struct reloc_control
*rc
;
4275 struct backref_node
*node
;
4280 rc
= root
->fs_info
->reloc_ctl
;
4284 BUG_ON(rc
->stage
== UPDATE_DATA_PTRS
&&
4285 root
->root_key
.objectid
== BTRFS_DATA_RELOC_TREE_OBJECTID
);
4287 level
= btrfs_header_level(buf
);
4288 if (btrfs_header_generation(buf
) <=
4289 btrfs_root_last_snapshot(&root
->root_item
))
4292 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
&&
4293 rc
->create_reloc_tree
) {
4294 WARN_ON(!first_cow
&& level
== 0);
4296 node
= rc
->backref_cache
.path
[level
];
4297 BUG_ON(node
->bytenr
!= buf
->start
&&
4298 node
->new_bytenr
!= buf
->start
);
4300 drop_node_buffer(node
);
4301 extent_buffer_get(cow
);
4303 node
->new_bytenr
= cow
->start
;
4305 if (!node
->pending
) {
4306 list_move_tail(&node
->list
,
4307 &rc
->backref_cache
.pending
[level
]);
4312 __mark_block_processed(rc
, node
);
4314 if (first_cow
&& level
> 0)
4315 rc
->nodes_relocated
+= buf
->len
;
4318 if (level
== 0 && first_cow
&& rc
->stage
== UPDATE_DATA_PTRS
) {
4319 ret
= replace_file_extents(trans
, rc
, root
, cow
);
4325 * called before creating snapshot. it calculates metadata reservation
4326 * requried for relocating tree blocks in the snapshot
4328 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle
*trans
,
4329 struct btrfs_pending_snapshot
*pending
,
4330 u64
*bytes_to_reserve
)
4332 struct btrfs_root
*root
;
4333 struct reloc_control
*rc
;
4335 root
= pending
->root
;
4336 if (!root
->reloc_root
)
4339 rc
= root
->fs_info
->reloc_ctl
;
4340 if (!rc
->merge_reloc_tree
)
4343 root
= root
->reloc_root
;
4344 BUG_ON(btrfs_root_refs(&root
->root_item
) == 0);
4346 * relocation is in the stage of merging trees. the space
4347 * used by merging a reloc tree is twice the size of
4348 * relocated tree nodes in the worst case. half for cowing
4349 * the reloc tree, half for cowing the fs tree. the space
4350 * used by cowing the reloc tree will be freed after the
4351 * tree is dropped. if we create snapshot, cowing the fs
4352 * tree may use more space than it frees. so we need
4353 * reserve extra space.
4355 *bytes_to_reserve
+= rc
->nodes_relocated
;
4359 * called after snapshot is created. migrate block reservation
4360 * and create reloc root for the newly created snapshot
4362 void btrfs_reloc_post_snapshot(struct btrfs_trans_handle
*trans
,
4363 struct btrfs_pending_snapshot
*pending
)
4365 struct btrfs_root
*root
= pending
->root
;
4366 struct btrfs_root
*reloc_root
;
4367 struct btrfs_root
*new_root
;
4368 struct reloc_control
*rc
;
4371 if (!root
->reloc_root
)
4374 rc
= root
->fs_info
->reloc_ctl
;
4375 rc
->merging_rsv_size
+= rc
->nodes_relocated
;
4377 if (rc
->merge_reloc_tree
) {
4378 ret
= btrfs_block_rsv_migrate(&pending
->block_rsv
,
4380 rc
->nodes_relocated
);
4384 new_root
= pending
->snap
;
4385 reloc_root
= create_reloc_root(trans
, root
->reloc_root
,
4386 new_root
->root_key
.objectid
);
4388 __add_reloc_root(reloc_root
);
4389 new_root
->reloc_root
= reloc_root
;
4391 if (rc
->create_reloc_tree
) {
4392 ret
= clone_backref_node(trans
, rc
, root
, reloc_root
);