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;
511 static int should_ignore_root(struct btrfs_root
*root
)
513 struct btrfs_root
*reloc_root
;
518 reloc_root
= root
->reloc_root
;
522 if (btrfs_root_last_snapshot(&reloc_root
->root_item
) ==
523 root
->fs_info
->running_transaction
->transid
- 1)
526 * if there is reloc tree and it was created in previous
527 * transaction backref lookup can find the reloc tree,
528 * 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 processsing
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(root
, path2
);
968 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
978 btrfs_release_path(rc
->extent_root
, 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
< entry
->vfs_inode
.i_ino
)
1414 node
= node
->rb_left
;
1415 else if (objectid
> entry
->vfs_inode
.i_ino
)
1416 node
= node
->rb_right
;
1422 entry
= rb_entry(prev
, struct btrfs_inode
, rb_node
);
1423 if (objectid
<= entry
->vfs_inode
.i_ino
) {
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
= entry
->vfs_inode
.i_ino
+ 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
, reloc_inode
->i_ino
,
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
&& inode
->i_ino
< key
.objectid
) {
1563 btrfs_add_delayed_iput(inode
);
1564 inode
= find_next_inode(root
, key
.objectid
);
1566 if (inode
&& inode
->i_ino
== 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(src
, 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
;
1898 objectid
= min_key
->objectid
;
1903 if (objectid
> max_key
->objectid
)
1906 inode
= find_next_inode(root
, objectid
);
1910 if (inode
->i_ino
> max_key
->objectid
) {
1915 objectid
= inode
->i_ino
+ 1;
1916 if (!S_ISREG(inode
->i_mode
))
1919 if (unlikely(min_key
->objectid
== inode
->i_ino
)) {
1920 if (min_key
->type
> BTRFS_EXTENT_DATA_KEY
)
1922 if (min_key
->type
< BTRFS_EXTENT_DATA_KEY
)
1925 start
= min_key
->offset
;
1926 WARN_ON(!IS_ALIGNED(start
, root
->sectorsize
));
1932 if (unlikely(max_key
->objectid
== inode
->i_ino
)) {
1933 if (max_key
->type
< BTRFS_EXTENT_DATA_KEY
)
1935 if (max_key
->type
> BTRFS_EXTENT_DATA_KEY
) {
1938 if (max_key
->offset
== 0)
1940 end
= max_key
->offset
;
1941 WARN_ON(!IS_ALIGNED(end
, root
->sectorsize
));
1948 /* the lock_extent waits for readpage to complete */
1949 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
1950 btrfs_drop_extent_cache(inode
, start
, end
, 1);
1951 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
1956 static int find_next_key(struct btrfs_path
*path
, int level
,
1957 struct btrfs_key
*key
)
1960 while (level
< BTRFS_MAX_LEVEL
) {
1961 if (!path
->nodes
[level
])
1963 if (path
->slots
[level
] + 1 <
1964 btrfs_header_nritems(path
->nodes
[level
])) {
1965 btrfs_node_key_to_cpu(path
->nodes
[level
], key
,
1966 path
->slots
[level
] + 1);
1975 * merge the relocated tree blocks in reloc tree with corresponding
1978 static noinline_for_stack
int merge_reloc_root(struct reloc_control
*rc
,
1979 struct btrfs_root
*root
)
1981 LIST_HEAD(inode_list
);
1982 struct btrfs_key key
;
1983 struct btrfs_key next_key
;
1984 struct btrfs_trans_handle
*trans
;
1985 struct btrfs_root
*reloc_root
;
1986 struct btrfs_root_item
*root_item
;
1987 struct btrfs_path
*path
;
1988 struct extent_buffer
*leaf
;
1997 path
= btrfs_alloc_path();
2001 reloc_root
= root
->reloc_root
;
2002 root_item
= &reloc_root
->root_item
;
2004 if (btrfs_disk_key_objectid(&root_item
->drop_progress
) == 0) {
2005 level
= btrfs_root_level(root_item
);
2006 extent_buffer_get(reloc_root
->node
);
2007 path
->nodes
[level
] = reloc_root
->node
;
2008 path
->slots
[level
] = 0;
2010 btrfs_disk_key_to_cpu(&key
, &root_item
->drop_progress
);
2012 level
= root_item
->drop_level
;
2014 path
->lowest_level
= level
;
2015 ret
= btrfs_search_slot(NULL
, reloc_root
, &key
, path
, 0, 0);
2016 path
->lowest_level
= 0;
2018 btrfs_free_path(path
);
2022 btrfs_node_key_to_cpu(path
->nodes
[level
], &next_key
,
2023 path
->slots
[level
]);
2024 WARN_ON(memcmp(&key
, &next_key
, sizeof(key
)));
2026 btrfs_unlock_up_safe(path
, 0);
2029 min_reserved
= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2030 memset(&next_key
, 0, sizeof(next_key
));
2033 trans
= btrfs_start_transaction(root
, 0);
2034 BUG_ON(IS_ERR(trans
));
2035 trans
->block_rsv
= rc
->block_rsv
;
2037 ret
= btrfs_block_rsv_check(trans
, root
, rc
->block_rsv
,
2040 BUG_ON(ret
!= -EAGAIN
);
2041 ret
= btrfs_commit_transaction(trans
, root
);
2049 ret
= walk_down_reloc_tree(reloc_root
, path
, &level
);
2057 if (!find_next_key(path
, level
, &key
) &&
2058 btrfs_comp_cpu_keys(&next_key
, &key
) >= 0) {
2061 ret
= replace_path(trans
, root
, reloc_root
, path
,
2062 &next_key
, level
, max_level
);
2071 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
2072 path
->slots
[level
]);
2076 ret
= walk_up_reloc_tree(reloc_root
, path
, &level
);
2082 * save the merging progress in the drop_progress.
2083 * this is OK since root refs == 1 in this case.
2085 btrfs_node_key(path
->nodes
[level
], &root_item
->drop_progress
,
2086 path
->slots
[level
]);
2087 root_item
->drop_level
= level
;
2089 nr
= trans
->blocks_used
;
2090 btrfs_end_transaction_throttle(trans
, root
);
2092 btrfs_btree_balance_dirty(root
, nr
);
2094 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2095 invalidate_extent_cache(root
, &key
, &next_key
);
2099 * handle the case only one block in the fs tree need to be
2100 * relocated and the block is tree root.
2102 leaf
= btrfs_lock_root_node(root
);
2103 ret
= btrfs_cow_block(trans
, root
, leaf
, NULL
, 0, &leaf
);
2104 btrfs_tree_unlock(leaf
);
2105 free_extent_buffer(leaf
);
2109 btrfs_free_path(path
);
2112 memset(&root_item
->drop_progress
, 0,
2113 sizeof(root_item
->drop_progress
));
2114 root_item
->drop_level
= 0;
2115 btrfs_set_root_refs(root_item
, 0);
2116 btrfs_update_reloc_root(trans
, root
);
2119 nr
= trans
->blocks_used
;
2120 btrfs_end_transaction_throttle(trans
, root
);
2122 btrfs_btree_balance_dirty(root
, nr
);
2124 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2125 invalidate_extent_cache(root
, &key
, &next_key
);
2130 static noinline_for_stack
2131 int prepare_to_merge(struct reloc_control
*rc
, int err
)
2133 struct btrfs_root
*root
= rc
->extent_root
;
2134 struct btrfs_root
*reloc_root
;
2135 struct btrfs_trans_handle
*trans
;
2136 LIST_HEAD(reloc_roots
);
2140 mutex_lock(&root
->fs_info
->trans_mutex
);
2141 rc
->merging_rsv_size
+= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2142 rc
->merging_rsv_size
+= rc
->nodes_relocated
* 2;
2143 mutex_unlock(&root
->fs_info
->trans_mutex
);
2146 num_bytes
= rc
->merging_rsv_size
;
2147 ret
= btrfs_block_rsv_add(NULL
, root
, rc
->block_rsv
,
2153 trans
= btrfs_join_transaction(rc
->extent_root
, 1);
2154 if (IS_ERR(trans
)) {
2156 btrfs_block_rsv_release(rc
->extent_root
,
2157 rc
->block_rsv
, num_bytes
);
2158 return PTR_ERR(trans
);
2162 if (num_bytes
!= rc
->merging_rsv_size
) {
2163 btrfs_end_transaction(trans
, rc
->extent_root
);
2164 btrfs_block_rsv_release(rc
->extent_root
,
2165 rc
->block_rsv
, num_bytes
);
2170 rc
->merge_reloc_tree
= 1;
2172 while (!list_empty(&rc
->reloc_roots
)) {
2173 reloc_root
= list_entry(rc
->reloc_roots
.next
,
2174 struct btrfs_root
, root_list
);
2175 list_del_init(&reloc_root
->root_list
);
2177 root
= read_fs_root(reloc_root
->fs_info
,
2178 reloc_root
->root_key
.offset
);
2179 BUG_ON(IS_ERR(root
));
2180 BUG_ON(root
->reloc_root
!= reloc_root
);
2183 * set reference count to 1, so btrfs_recover_relocation
2184 * knows it should resumes merging
2187 btrfs_set_root_refs(&reloc_root
->root_item
, 1);
2188 btrfs_update_reloc_root(trans
, root
);
2190 list_add(&reloc_root
->root_list
, &reloc_roots
);
2193 list_splice(&reloc_roots
, &rc
->reloc_roots
);
2196 btrfs_commit_transaction(trans
, rc
->extent_root
);
2198 btrfs_end_transaction(trans
, rc
->extent_root
);
2202 static noinline_for_stack
2203 int merge_reloc_roots(struct reloc_control
*rc
)
2205 struct btrfs_root
*root
;
2206 struct btrfs_root
*reloc_root
;
2207 LIST_HEAD(reloc_roots
);
2211 root
= rc
->extent_root
;
2212 mutex_lock(&root
->fs_info
->trans_mutex
);
2213 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
2214 mutex_unlock(&root
->fs_info
->trans_mutex
);
2216 while (!list_empty(&reloc_roots
)) {
2218 reloc_root
= list_entry(reloc_roots
.next
,
2219 struct btrfs_root
, root_list
);
2221 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
2222 root
= read_fs_root(reloc_root
->fs_info
,
2223 reloc_root
->root_key
.offset
);
2224 BUG_ON(IS_ERR(root
));
2225 BUG_ON(root
->reloc_root
!= reloc_root
);
2227 ret
= merge_reloc_root(rc
, root
);
2230 list_del_init(&reloc_root
->root_list
);
2232 btrfs_drop_snapshot(reloc_root
, rc
->block_rsv
, 0);
2239 BUG_ON(!RB_EMPTY_ROOT(&rc
->reloc_root_tree
.rb_root
));
2243 static void free_block_list(struct rb_root
*blocks
)
2245 struct tree_block
*block
;
2246 struct rb_node
*rb_node
;
2247 while ((rb_node
= rb_first(blocks
))) {
2248 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2249 rb_erase(rb_node
, blocks
);
2254 static int record_reloc_root_in_trans(struct btrfs_trans_handle
*trans
,
2255 struct btrfs_root
*reloc_root
)
2257 struct btrfs_root
*root
;
2259 if (reloc_root
->last_trans
== trans
->transid
)
2262 root
= read_fs_root(reloc_root
->fs_info
, reloc_root
->root_key
.offset
);
2263 BUG_ON(IS_ERR(root
));
2264 BUG_ON(root
->reloc_root
!= reloc_root
);
2266 return btrfs_record_root_in_trans(trans
, root
);
2269 static noinline_for_stack
2270 struct btrfs_root
*select_reloc_root(struct btrfs_trans_handle
*trans
,
2271 struct reloc_control
*rc
,
2272 struct backref_node
*node
,
2273 struct backref_edge
*edges
[], int *nr
)
2275 struct backref_node
*next
;
2276 struct btrfs_root
*root
;
2282 next
= walk_up_backref(next
, edges
, &index
);
2285 BUG_ON(!root
->ref_cows
);
2287 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
2288 record_reloc_root_in_trans(trans
, root
);
2292 btrfs_record_root_in_trans(trans
, root
);
2293 root
= root
->reloc_root
;
2295 if (next
->new_bytenr
!= root
->node
->start
) {
2296 BUG_ON(next
->new_bytenr
);
2297 BUG_ON(!list_empty(&next
->list
));
2298 next
->new_bytenr
= root
->node
->start
;
2300 list_add_tail(&next
->list
,
2301 &rc
->backref_cache
.changed
);
2302 __mark_block_processed(rc
, next
);
2308 next
= walk_down_backref(edges
, &index
);
2309 if (!next
|| next
->level
<= node
->level
)
2317 /* setup backref node path for btrfs_reloc_cow_block */
2319 rc
->backref_cache
.path
[next
->level
] = next
;
2322 next
= edges
[index
]->node
[UPPER
];
2328 * select a tree root for relocation. return NULL if the block
2329 * is reference counted. we should use do_relocation() in this
2330 * case. return a tree root pointer if the block isn't reference
2331 * counted. return -ENOENT if the block is root of reloc tree.
2333 static noinline_for_stack
2334 struct btrfs_root
*select_one_root(struct btrfs_trans_handle
*trans
,
2335 struct backref_node
*node
)
2337 struct backref_node
*next
;
2338 struct btrfs_root
*root
;
2339 struct btrfs_root
*fs_root
= NULL
;
2340 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2346 next
= walk_up_backref(next
, edges
, &index
);
2350 /* no other choice for non-refernce counted tree */
2351 if (!root
->ref_cows
)
2354 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
)
2360 next
= walk_down_backref(edges
, &index
);
2361 if (!next
|| next
->level
<= node
->level
)
2366 return ERR_PTR(-ENOENT
);
2370 static noinline_for_stack
2371 u64
calcu_metadata_size(struct reloc_control
*rc
,
2372 struct backref_node
*node
, int reserve
)
2374 struct backref_node
*next
= node
;
2375 struct backref_edge
*edge
;
2376 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2380 BUG_ON(reserve
&& node
->processed
);
2385 if (next
->processed
&& (reserve
|| next
!= node
))
2388 num_bytes
+= btrfs_level_size(rc
->extent_root
,
2391 if (list_empty(&next
->upper
))
2394 edge
= list_entry(next
->upper
.next
,
2395 struct backref_edge
, list
[LOWER
]);
2396 edges
[index
++] = edge
;
2397 next
= edge
->node
[UPPER
];
2399 next
= walk_down_backref(edges
, &index
);
2404 static int reserve_metadata_space(struct btrfs_trans_handle
*trans
,
2405 struct reloc_control
*rc
,
2406 struct backref_node
*node
)
2408 struct btrfs_root
*root
= rc
->extent_root
;
2412 num_bytes
= calcu_metadata_size(rc
, node
, 1) * 2;
2414 trans
->block_rsv
= rc
->block_rsv
;
2415 ret
= btrfs_block_rsv_add(trans
, root
, rc
->block_rsv
, num_bytes
);
2418 rc
->commit_transaction
= 1;
2425 static void release_metadata_space(struct reloc_control
*rc
,
2426 struct backref_node
*node
)
2428 u64 num_bytes
= calcu_metadata_size(rc
, node
, 0) * 2;
2429 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, num_bytes
);
2433 * relocate a block tree, and then update pointers in upper level
2434 * blocks that reference the block to point to the new location.
2436 * if called by link_to_upper, the block has already been relocated.
2437 * in that case this function just updates pointers.
2439 static int do_relocation(struct btrfs_trans_handle
*trans
,
2440 struct reloc_control
*rc
,
2441 struct backref_node
*node
,
2442 struct btrfs_key
*key
,
2443 struct btrfs_path
*path
, int lowest
)
2445 struct backref_node
*upper
;
2446 struct backref_edge
*edge
;
2447 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2448 struct btrfs_root
*root
;
2449 struct extent_buffer
*eb
;
2458 BUG_ON(lowest
&& node
->eb
);
2460 path
->lowest_level
= node
->level
+ 1;
2461 rc
->backref_cache
.path
[node
->level
] = node
;
2462 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
]) {
2465 upper
= edge
->node
[UPPER
];
2466 root
= select_reloc_root(trans
, rc
, upper
, edges
, &nr
);
2469 if (upper
->eb
&& !upper
->locked
) {
2471 ret
= btrfs_bin_search(upper
->eb
, key
,
2472 upper
->level
, &slot
);
2474 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2475 if (node
->eb
->start
== bytenr
)
2478 drop_node_buffer(upper
);
2482 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2490 upper
->eb
= path
->nodes
[upper
->level
];
2491 path
->nodes
[upper
->level
] = NULL
;
2493 BUG_ON(upper
->eb
!= path
->nodes
[upper
->level
]);
2497 path
->locks
[upper
->level
] = 0;
2499 slot
= path
->slots
[upper
->level
];
2500 btrfs_release_path(NULL
, path
);
2502 ret
= btrfs_bin_search(upper
->eb
, key
, upper
->level
,
2507 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2509 BUG_ON(bytenr
!= node
->bytenr
);
2511 if (node
->eb
->start
== bytenr
)
2515 blocksize
= btrfs_level_size(root
, node
->level
);
2516 generation
= btrfs_node_ptr_generation(upper
->eb
, slot
);
2517 eb
= read_tree_block(root
, bytenr
, blocksize
, generation
);
2522 btrfs_tree_lock(eb
);
2523 btrfs_set_lock_blocking(eb
);
2526 ret
= btrfs_cow_block(trans
, root
, eb
, upper
->eb
,
2528 btrfs_tree_unlock(eb
);
2529 free_extent_buffer(eb
);
2534 BUG_ON(node
->eb
!= eb
);
2536 btrfs_set_node_blockptr(upper
->eb
, slot
,
2538 btrfs_set_node_ptr_generation(upper
->eb
, slot
,
2540 btrfs_mark_buffer_dirty(upper
->eb
);
2542 ret
= btrfs_inc_extent_ref(trans
, root
,
2543 node
->eb
->start
, blocksize
,
2545 btrfs_header_owner(upper
->eb
),
2549 ret
= btrfs_drop_subtree(trans
, root
, eb
, upper
->eb
);
2553 if (!upper
->pending
)
2554 drop_node_buffer(upper
);
2556 unlock_node_buffer(upper
);
2561 if (!err
&& node
->pending
) {
2562 drop_node_buffer(node
);
2563 list_move_tail(&node
->list
, &rc
->backref_cache
.changed
);
2567 path
->lowest_level
= 0;
2568 BUG_ON(err
== -ENOSPC
);
2572 static int link_to_upper(struct btrfs_trans_handle
*trans
,
2573 struct reloc_control
*rc
,
2574 struct backref_node
*node
,
2575 struct btrfs_path
*path
)
2577 struct btrfs_key key
;
2579 btrfs_node_key_to_cpu(node
->eb
, &key
, 0);
2580 return do_relocation(trans
, rc
, node
, &key
, path
, 0);
2583 static int finish_pending_nodes(struct btrfs_trans_handle
*trans
,
2584 struct reloc_control
*rc
,
2585 struct btrfs_path
*path
, int err
)
2588 struct backref_cache
*cache
= &rc
->backref_cache
;
2589 struct backref_node
*node
;
2593 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
2594 while (!list_empty(&cache
->pending
[level
])) {
2595 node
= list_entry(cache
->pending
[level
].next
,
2596 struct backref_node
, list
);
2597 list_move_tail(&node
->list
, &list
);
2598 BUG_ON(!node
->pending
);
2601 ret
= link_to_upper(trans
, rc
, node
, path
);
2606 list_splice_init(&list
, &cache
->pending
[level
]);
2611 static void mark_block_processed(struct reloc_control
*rc
,
2612 u64 bytenr
, u32 blocksize
)
2614 set_extent_bits(&rc
->processed_blocks
, bytenr
, bytenr
+ blocksize
- 1,
2615 EXTENT_DIRTY
, GFP_NOFS
);
2618 static void __mark_block_processed(struct reloc_control
*rc
,
2619 struct backref_node
*node
)
2622 if (node
->level
== 0 ||
2623 in_block_group(node
->bytenr
, rc
->block_group
)) {
2624 blocksize
= btrfs_level_size(rc
->extent_root
, node
->level
);
2625 mark_block_processed(rc
, node
->bytenr
, blocksize
);
2627 node
->processed
= 1;
2631 * mark a block and all blocks directly/indirectly reference the block
2634 static void update_processed_blocks(struct reloc_control
*rc
,
2635 struct backref_node
*node
)
2637 struct backref_node
*next
= node
;
2638 struct backref_edge
*edge
;
2639 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2645 if (next
->processed
)
2648 __mark_block_processed(rc
, next
);
2650 if (list_empty(&next
->upper
))
2653 edge
= list_entry(next
->upper
.next
,
2654 struct backref_edge
, list
[LOWER
]);
2655 edges
[index
++] = edge
;
2656 next
= edge
->node
[UPPER
];
2658 next
= walk_down_backref(edges
, &index
);
2662 static int tree_block_processed(u64 bytenr
, u32 blocksize
,
2663 struct reloc_control
*rc
)
2665 if (test_range_bit(&rc
->processed_blocks
, bytenr
,
2666 bytenr
+ blocksize
- 1, EXTENT_DIRTY
, 1, NULL
))
2671 static int get_tree_block_key(struct reloc_control
*rc
,
2672 struct tree_block
*block
)
2674 struct extent_buffer
*eb
;
2676 BUG_ON(block
->key_ready
);
2677 eb
= read_tree_block(rc
->extent_root
, block
->bytenr
,
2678 block
->key
.objectid
, block
->key
.offset
);
2680 WARN_ON(btrfs_header_level(eb
) != block
->level
);
2681 if (block
->level
== 0)
2682 btrfs_item_key_to_cpu(eb
, &block
->key
, 0);
2684 btrfs_node_key_to_cpu(eb
, &block
->key
, 0);
2685 free_extent_buffer(eb
);
2686 block
->key_ready
= 1;
2690 static int reada_tree_block(struct reloc_control
*rc
,
2691 struct tree_block
*block
)
2693 BUG_ON(block
->key_ready
);
2694 readahead_tree_block(rc
->extent_root
, block
->bytenr
,
2695 block
->key
.objectid
, block
->key
.offset
);
2700 * helper function to relocate a tree block
2702 static int relocate_tree_block(struct btrfs_trans_handle
*trans
,
2703 struct reloc_control
*rc
,
2704 struct backref_node
*node
,
2705 struct btrfs_key
*key
,
2706 struct btrfs_path
*path
)
2708 struct btrfs_root
*root
;
2715 BUG_ON(node
->processed
);
2716 root
= select_one_root(trans
, node
);
2717 if (root
== ERR_PTR(-ENOENT
)) {
2718 update_processed_blocks(rc
, node
);
2722 if (!root
|| root
->ref_cows
) {
2723 ret
= reserve_metadata_space(trans
, rc
, node
);
2730 if (root
->ref_cows
) {
2731 BUG_ON(node
->new_bytenr
);
2732 BUG_ON(!list_empty(&node
->list
));
2733 btrfs_record_root_in_trans(trans
, root
);
2734 root
= root
->reloc_root
;
2735 node
->new_bytenr
= root
->node
->start
;
2737 list_add_tail(&node
->list
, &rc
->backref_cache
.changed
);
2739 path
->lowest_level
= node
->level
;
2740 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2741 btrfs_release_path(root
, path
);
2746 update_processed_blocks(rc
, node
);
2748 ret
= do_relocation(trans
, rc
, node
, key
, path
, 1);
2751 if (ret
|| node
->level
== 0 || node
->cowonly
) {
2753 release_metadata_space(rc
, node
);
2754 remove_backref_node(&rc
->backref_cache
, node
);
2760 * relocate a list of blocks
2762 static noinline_for_stack
2763 int relocate_tree_blocks(struct btrfs_trans_handle
*trans
,
2764 struct reloc_control
*rc
, struct rb_root
*blocks
)
2766 struct backref_node
*node
;
2767 struct btrfs_path
*path
;
2768 struct tree_block
*block
;
2769 struct rb_node
*rb_node
;
2773 path
= btrfs_alloc_path();
2777 rb_node
= rb_first(blocks
);
2779 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2780 if (!block
->key_ready
)
2781 reada_tree_block(rc
, block
);
2782 rb_node
= rb_next(rb_node
);
2785 rb_node
= rb_first(blocks
);
2787 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2788 if (!block
->key_ready
)
2789 get_tree_block_key(rc
, block
);
2790 rb_node
= rb_next(rb_node
);
2793 rb_node
= rb_first(blocks
);
2795 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2797 node
= build_backref_tree(rc
, &block
->key
,
2798 block
->level
, block
->bytenr
);
2800 err
= PTR_ERR(node
);
2804 ret
= relocate_tree_block(trans
, rc
, node
, &block
->key
,
2807 if (ret
!= -EAGAIN
|| rb_node
== rb_first(blocks
))
2811 rb_node
= rb_next(rb_node
);
2814 free_block_list(blocks
);
2815 err
= finish_pending_nodes(trans
, rc
, path
, err
);
2817 btrfs_free_path(path
);
2821 static noinline_for_stack
2822 int prealloc_file_extent_cluster(struct inode
*inode
,
2823 struct file_extent_cluster
*cluster
)
2828 u64 offset
= BTRFS_I(inode
)->index_cnt
;
2833 BUG_ON(cluster
->start
!= cluster
->boundary
[0]);
2834 mutex_lock(&inode
->i_mutex
);
2836 ret
= btrfs_check_data_free_space(inode
, cluster
->end
+
2837 1 - cluster
->start
);
2841 while (nr
< cluster
->nr
) {
2842 start
= cluster
->boundary
[nr
] - offset
;
2843 if (nr
+ 1 < cluster
->nr
)
2844 end
= cluster
->boundary
[nr
+ 1] - 1 - offset
;
2846 end
= cluster
->end
- offset
;
2848 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2849 num_bytes
= end
+ 1 - start
;
2850 ret
= btrfs_prealloc_file_range(inode
, 0, start
,
2851 num_bytes
, num_bytes
,
2852 end
+ 1, &alloc_hint
);
2853 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2858 btrfs_free_reserved_data_space(inode
, cluster
->end
+
2859 1 - cluster
->start
);
2861 mutex_unlock(&inode
->i_mutex
);
2865 static noinline_for_stack
2866 int setup_extent_mapping(struct inode
*inode
, u64 start
, u64 end
,
2869 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
2870 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2871 struct extent_map
*em
;
2874 em
= alloc_extent_map(GFP_NOFS
);
2879 em
->len
= end
+ 1 - start
;
2880 em
->block_len
= em
->len
;
2881 em
->block_start
= block_start
;
2882 em
->bdev
= root
->fs_info
->fs_devices
->latest_bdev
;
2883 set_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
2885 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2887 write_lock(&em_tree
->lock
);
2888 ret
= add_extent_mapping(em_tree
, em
);
2889 write_unlock(&em_tree
->lock
);
2890 if (ret
!= -EEXIST
) {
2891 free_extent_map(em
);
2894 btrfs_drop_extent_cache(inode
, start
, end
, 0);
2896 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
, GFP_NOFS
);
2900 static int relocate_file_extent_cluster(struct inode
*inode
,
2901 struct file_extent_cluster
*cluster
)
2905 u64 offset
= BTRFS_I(inode
)->index_cnt
;
2906 unsigned long index
;
2907 unsigned long last_index
;
2909 struct file_ra_state
*ra
;
2916 ra
= kzalloc(sizeof(*ra
), GFP_NOFS
);
2920 ret
= prealloc_file_extent_cluster(inode
, cluster
);
2924 file_ra_state_init(ra
, inode
->i_mapping
);
2926 ret
= setup_extent_mapping(inode
, cluster
->start
- offset
,
2927 cluster
->end
- offset
, cluster
->start
);
2931 index
= (cluster
->start
- offset
) >> PAGE_CACHE_SHIFT
;
2932 last_index
= (cluster
->end
- offset
) >> PAGE_CACHE_SHIFT
;
2933 while (index
<= last_index
) {
2934 ret
= btrfs_delalloc_reserve_metadata(inode
, PAGE_CACHE_SIZE
);
2938 page
= find_lock_page(inode
->i_mapping
, index
);
2940 page_cache_sync_readahead(inode
->i_mapping
,
2942 last_index
+ 1 - index
);
2943 page
= grab_cache_page(inode
->i_mapping
, index
);
2945 btrfs_delalloc_release_metadata(inode
,
2952 if (PageReadahead(page
)) {
2953 page_cache_async_readahead(inode
->i_mapping
,
2954 ra
, NULL
, page
, index
,
2955 last_index
+ 1 - index
);
2958 if (!PageUptodate(page
)) {
2959 btrfs_readpage(NULL
, page
);
2961 if (!PageUptodate(page
)) {
2963 page_cache_release(page
);
2964 btrfs_delalloc_release_metadata(inode
,
2971 page_start
= (u64
)page
->index
<< PAGE_CACHE_SHIFT
;
2972 page_end
= page_start
+ PAGE_CACHE_SIZE
- 1;
2974 lock_extent(&BTRFS_I(inode
)->io_tree
,
2975 page_start
, page_end
, GFP_NOFS
);
2977 set_page_extent_mapped(page
);
2979 if (nr
< cluster
->nr
&&
2980 page_start
+ offset
== cluster
->boundary
[nr
]) {
2981 set_extent_bits(&BTRFS_I(inode
)->io_tree
,
2982 page_start
, page_end
,
2983 EXTENT_BOUNDARY
, GFP_NOFS
);
2987 btrfs_set_extent_delalloc(inode
, page_start
, page_end
, NULL
);
2988 set_page_dirty(page
);
2990 unlock_extent(&BTRFS_I(inode
)->io_tree
,
2991 page_start
, page_end
, GFP_NOFS
);
2993 page_cache_release(page
);
2996 balance_dirty_pages_ratelimited(inode
->i_mapping
);
2997 btrfs_throttle(BTRFS_I(inode
)->root
);
2999 WARN_ON(nr
!= cluster
->nr
);
3005 static noinline_for_stack
3006 int relocate_data_extent(struct inode
*inode
, struct btrfs_key
*extent_key
,
3007 struct file_extent_cluster
*cluster
)
3011 if (cluster
->nr
> 0 && extent_key
->objectid
!= cluster
->end
+ 1) {
3012 ret
= relocate_file_extent_cluster(inode
, cluster
);
3019 cluster
->start
= extent_key
->objectid
;
3021 BUG_ON(cluster
->nr
>= MAX_EXTENTS
);
3022 cluster
->end
= extent_key
->objectid
+ extent_key
->offset
- 1;
3023 cluster
->boundary
[cluster
->nr
] = extent_key
->objectid
;
3026 if (cluster
->nr
>= MAX_EXTENTS
) {
3027 ret
= relocate_file_extent_cluster(inode
, cluster
);
3035 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3036 static int get_ref_objectid_v0(struct reloc_control
*rc
,
3037 struct btrfs_path
*path
,
3038 struct btrfs_key
*extent_key
,
3039 u64
*ref_objectid
, int *path_change
)
3041 struct btrfs_key key
;
3042 struct extent_buffer
*leaf
;
3043 struct btrfs_extent_ref_v0
*ref0
;
3047 leaf
= path
->nodes
[0];
3048 slot
= path
->slots
[0];
3050 if (slot
>= btrfs_header_nritems(leaf
)) {
3051 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3055 leaf
= path
->nodes
[0];
3056 slot
= path
->slots
[0];
3060 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
3061 if (key
.objectid
!= extent_key
->objectid
)
3064 if (key
.type
!= BTRFS_EXTENT_REF_V0_KEY
) {
3068 ref0
= btrfs_item_ptr(leaf
, slot
,
3069 struct btrfs_extent_ref_v0
);
3070 *ref_objectid
= btrfs_ref_objectid_v0(leaf
, ref0
);
3078 * helper to add a tree block to the list.
3079 * the major work is getting the generation and level of the block
3081 static int add_tree_block(struct reloc_control
*rc
,
3082 struct btrfs_key
*extent_key
,
3083 struct btrfs_path
*path
,
3084 struct rb_root
*blocks
)
3086 struct extent_buffer
*eb
;
3087 struct btrfs_extent_item
*ei
;
3088 struct btrfs_tree_block_info
*bi
;
3089 struct tree_block
*block
;
3090 struct rb_node
*rb_node
;
3095 eb
= path
->nodes
[0];
3096 item_size
= btrfs_item_size_nr(eb
, path
->slots
[0]);
3098 if (item_size
>= sizeof(*ei
) + sizeof(*bi
)) {
3099 ei
= btrfs_item_ptr(eb
, path
->slots
[0],
3100 struct btrfs_extent_item
);
3101 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
3102 generation
= btrfs_extent_generation(eb
, ei
);
3103 level
= btrfs_tree_block_level(eb
, bi
);
3105 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3109 BUG_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
3110 ret
= get_ref_objectid_v0(rc
, path
, extent_key
,
3114 BUG_ON(ref_owner
>= BTRFS_MAX_LEVEL
);
3115 level
= (int)ref_owner
;
3116 /* FIXME: get real generation */
3123 btrfs_release_path(rc
->extent_root
, path
);
3125 BUG_ON(level
== -1);
3127 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3131 block
->bytenr
= extent_key
->objectid
;
3132 block
->key
.objectid
= extent_key
->offset
;
3133 block
->key
.offset
= generation
;
3134 block
->level
= level
;
3135 block
->key_ready
= 0;
3137 rb_node
= tree_insert(blocks
, block
->bytenr
, &block
->rb_node
);
3144 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3146 static int __add_tree_block(struct reloc_control
*rc
,
3147 u64 bytenr
, u32 blocksize
,
3148 struct rb_root
*blocks
)
3150 struct btrfs_path
*path
;
3151 struct btrfs_key key
;
3154 if (tree_block_processed(bytenr
, blocksize
, rc
))
3157 if (tree_search(blocks
, bytenr
))
3160 path
= btrfs_alloc_path();
3164 key
.objectid
= bytenr
;
3165 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3166 key
.offset
= blocksize
;
3168 path
->search_commit_root
= 1;
3169 path
->skip_locking
= 1;
3170 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
, 0, 0);
3175 btrfs_item_key_to_cpu(path
->nodes
[0], &key
, path
->slots
[0]);
3176 ret
= add_tree_block(rc
, &key
, path
, blocks
);
3178 btrfs_free_path(path
);
3183 * helper to check if the block use full backrefs for pointers in it
3185 static int block_use_full_backref(struct reloc_control
*rc
,
3186 struct extent_buffer
*eb
)
3191 if (btrfs_header_flag(eb
, BTRFS_HEADER_FLAG_RELOC
) ||
3192 btrfs_header_backref_rev(eb
) < BTRFS_MIXED_BACKREF_REV
)
3195 ret
= btrfs_lookup_extent_info(NULL
, rc
->extent_root
,
3196 eb
->start
, eb
->len
, NULL
, &flags
);
3199 if (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
)
3206 static int delete_block_group_cache(struct btrfs_fs_info
*fs_info
,
3207 struct inode
*inode
, u64 ino
)
3209 struct btrfs_key key
;
3210 struct btrfs_path
*path
;
3211 struct btrfs_root
*root
= fs_info
->tree_root
;
3212 struct btrfs_trans_handle
*trans
;
3220 key
.type
= BTRFS_INODE_ITEM_KEY
;
3223 inode
= btrfs_iget(fs_info
->sb
, &key
, root
, NULL
);
3224 if (!inode
|| IS_ERR(inode
) || is_bad_inode(inode
)) {
3225 if (inode
&& !IS_ERR(inode
))
3231 path
= btrfs_alloc_path();
3237 trans
= btrfs_join_transaction(root
, 0);
3238 if (IS_ERR(trans
)) {
3239 btrfs_free_path(path
);
3240 ret
= PTR_ERR(trans
);
3244 ret
= btrfs_truncate_free_space_cache(root
, trans
, path
, inode
);
3246 btrfs_free_path(path
);
3247 nr
= trans
->blocks_used
;
3248 btrfs_end_transaction(trans
, root
);
3249 btrfs_btree_balance_dirty(root
, nr
);
3256 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3257 * this function scans fs tree to find blocks reference the data extent
3259 static int find_data_references(struct reloc_control
*rc
,
3260 struct btrfs_key
*extent_key
,
3261 struct extent_buffer
*leaf
,
3262 struct btrfs_extent_data_ref
*ref
,
3263 struct rb_root
*blocks
)
3265 struct btrfs_path
*path
;
3266 struct tree_block
*block
;
3267 struct btrfs_root
*root
;
3268 struct btrfs_file_extent_item
*fi
;
3269 struct rb_node
*rb_node
;
3270 struct btrfs_key key
;
3281 ref_root
= btrfs_extent_data_ref_root(leaf
, ref
);
3282 ref_objectid
= btrfs_extent_data_ref_objectid(leaf
, ref
);
3283 ref_offset
= btrfs_extent_data_ref_offset(leaf
, ref
);
3284 ref_count
= btrfs_extent_data_ref_count(leaf
, ref
);
3287 * This is an extent belonging to the free space cache, lets just delete
3288 * it and redo the search.
3290 if (ref_root
== BTRFS_ROOT_TREE_OBJECTID
) {
3291 ret
= delete_block_group_cache(rc
->extent_root
->fs_info
,
3292 NULL
, ref_objectid
);
3298 path
= btrfs_alloc_path();
3302 root
= read_fs_root(rc
->extent_root
->fs_info
, ref_root
);
3304 err
= PTR_ERR(root
);
3308 key
.objectid
= ref_objectid
;
3309 key
.offset
= ref_offset
;
3310 key
.type
= BTRFS_EXTENT_DATA_KEY
;
3312 path
->search_commit_root
= 1;
3313 path
->skip_locking
= 1;
3314 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
3320 leaf
= path
->nodes
[0];
3321 nritems
= btrfs_header_nritems(leaf
);
3323 * the references in tree blocks that use full backrefs
3324 * are not counted in
3326 if (block_use_full_backref(rc
, leaf
))
3330 rb_node
= tree_search(blocks
, leaf
->start
);
3335 path
->slots
[0] = nritems
;
3338 while (ref_count
> 0) {
3339 while (path
->slots
[0] >= nritems
) {
3340 ret
= btrfs_next_leaf(root
, path
);
3350 leaf
= path
->nodes
[0];
3351 nritems
= btrfs_header_nritems(leaf
);
3354 if (block_use_full_backref(rc
, leaf
))
3358 rb_node
= tree_search(blocks
, leaf
->start
);
3363 path
->slots
[0] = nritems
;
3367 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3368 if (key
.objectid
!= ref_objectid
||
3369 key
.type
!= BTRFS_EXTENT_DATA_KEY
) {
3374 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3375 struct btrfs_file_extent_item
);
3377 if (btrfs_file_extent_type(leaf
, fi
) ==
3378 BTRFS_FILE_EXTENT_INLINE
)
3381 if (btrfs_file_extent_disk_bytenr(leaf
, fi
) !=
3382 extent_key
->objectid
)
3385 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
3386 if (key
.offset
!= ref_offset
)
3394 if (!tree_block_processed(leaf
->start
, leaf
->len
, rc
)) {
3395 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3400 block
->bytenr
= leaf
->start
;
3401 btrfs_item_key_to_cpu(leaf
, &block
->key
, 0);
3403 block
->key_ready
= 1;
3404 rb_node
= tree_insert(blocks
, block
->bytenr
,
3411 path
->slots
[0] = nritems
;
3417 btrfs_free_path(path
);
3422 * hepler to find all tree blocks that reference a given data extent
3424 static noinline_for_stack
3425 int add_data_references(struct reloc_control
*rc
,
3426 struct btrfs_key
*extent_key
,
3427 struct btrfs_path
*path
,
3428 struct rb_root
*blocks
)
3430 struct btrfs_key key
;
3431 struct extent_buffer
*eb
;
3432 struct btrfs_extent_data_ref
*dref
;
3433 struct btrfs_extent_inline_ref
*iref
;
3436 u32 blocksize
= btrfs_level_size(rc
->extent_root
, 0);
3440 eb
= path
->nodes
[0];
3441 ptr
= btrfs_item_ptr_offset(eb
, path
->slots
[0]);
3442 end
= ptr
+ btrfs_item_size_nr(eb
, path
->slots
[0]);
3443 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3444 if (ptr
+ sizeof(struct btrfs_extent_item_v0
) == end
)
3448 ptr
+= sizeof(struct btrfs_extent_item
);
3451 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
3452 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
3453 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3454 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
3455 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3457 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3458 dref
= (struct btrfs_extent_data_ref
*)(&iref
->offset
);
3459 ret
= find_data_references(rc
, extent_key
,
3464 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
3470 eb
= path
->nodes
[0];
3471 if (path
->slots
[0] >= btrfs_header_nritems(eb
)) {
3472 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3479 eb
= path
->nodes
[0];
3482 btrfs_item_key_to_cpu(eb
, &key
, path
->slots
[0]);
3483 if (key
.objectid
!= extent_key
->objectid
)
3486 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3487 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
||
3488 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
3490 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
3491 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3493 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3495 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3496 dref
= btrfs_item_ptr(eb
, path
->slots
[0],
3497 struct btrfs_extent_data_ref
);
3498 ret
= find_data_references(rc
, extent_key
,
3509 btrfs_release_path(rc
->extent_root
, path
);
3511 free_block_list(blocks
);
3516 * hepler to find next unprocessed extent
3518 static noinline_for_stack
3519 int find_next_extent(struct btrfs_trans_handle
*trans
,
3520 struct reloc_control
*rc
, struct btrfs_path
*path
,
3521 struct btrfs_key
*extent_key
)
3523 struct btrfs_key key
;
3524 struct extent_buffer
*leaf
;
3525 u64 start
, end
, last
;
3528 last
= rc
->block_group
->key
.objectid
+ rc
->block_group
->key
.offset
;
3531 if (rc
->search_start
>= last
) {
3536 key
.objectid
= rc
->search_start
;
3537 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3540 path
->search_commit_root
= 1;
3541 path
->skip_locking
= 1;
3542 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
,
3547 leaf
= path
->nodes
[0];
3548 if (path
->slots
[0] >= btrfs_header_nritems(leaf
)) {
3549 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3552 leaf
= path
->nodes
[0];
3555 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3556 if (key
.objectid
>= last
) {
3561 if (key
.type
!= BTRFS_EXTENT_ITEM_KEY
||
3562 key
.objectid
+ key
.offset
<= rc
->search_start
) {
3567 ret
= find_first_extent_bit(&rc
->processed_blocks
,
3568 key
.objectid
, &start
, &end
,
3571 if (ret
== 0 && start
<= key
.objectid
) {
3572 btrfs_release_path(rc
->extent_root
, path
);
3573 rc
->search_start
= end
+ 1;
3575 rc
->search_start
= key
.objectid
+ key
.offset
;
3576 memcpy(extent_key
, &key
, sizeof(key
));
3580 btrfs_release_path(rc
->extent_root
, path
);
3584 static void set_reloc_control(struct reloc_control
*rc
)
3586 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3587 mutex_lock(&fs_info
->trans_mutex
);
3588 fs_info
->reloc_ctl
= rc
;
3589 mutex_unlock(&fs_info
->trans_mutex
);
3592 static void unset_reloc_control(struct reloc_control
*rc
)
3594 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3595 mutex_lock(&fs_info
->trans_mutex
);
3596 fs_info
->reloc_ctl
= NULL
;
3597 mutex_unlock(&fs_info
->trans_mutex
);
3600 static int check_extent_flags(u64 flags
)
3602 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3603 (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3605 if (!(flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3606 !(flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3608 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3609 (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
))
3614 static noinline_for_stack
3615 int prepare_to_relocate(struct reloc_control
*rc
)
3617 struct btrfs_trans_handle
*trans
;
3620 rc
->block_rsv
= btrfs_alloc_block_rsv(rc
->extent_root
);
3625 * reserve some space for creating reloc trees.
3626 * btrfs_init_reloc_root will use them when there
3627 * is no reservation in transaction handle.
3629 ret
= btrfs_block_rsv_add(NULL
, rc
->extent_root
, rc
->block_rsv
,
3630 rc
->extent_root
->nodesize
* 256);
3634 rc
->block_rsv
->refill_used
= 1;
3635 btrfs_add_durable_block_rsv(rc
->extent_root
->fs_info
, rc
->block_rsv
);
3637 memset(&rc
->cluster
, 0, sizeof(rc
->cluster
));
3638 rc
->search_start
= rc
->block_group
->key
.objectid
;
3639 rc
->extents_found
= 0;
3640 rc
->nodes_relocated
= 0;
3641 rc
->merging_rsv_size
= 0;
3643 rc
->create_reloc_tree
= 1;
3644 set_reloc_control(rc
);
3646 trans
= btrfs_join_transaction(rc
->extent_root
, 1);
3647 BUG_ON(IS_ERR(trans
));
3648 btrfs_commit_transaction(trans
, rc
->extent_root
);
3652 static noinline_for_stack
int relocate_block_group(struct reloc_control
*rc
)
3654 struct rb_root blocks
= RB_ROOT
;
3655 struct btrfs_key key
;
3656 struct btrfs_trans_handle
*trans
= NULL
;
3657 struct btrfs_path
*path
;
3658 struct btrfs_extent_item
*ei
;
3666 path
= btrfs_alloc_path();
3670 ret
= prepare_to_relocate(rc
);
3678 trans
= btrfs_start_transaction(rc
->extent_root
, 0);
3679 BUG_ON(IS_ERR(trans
));
3681 if (update_backref_cache(trans
, &rc
->backref_cache
)) {
3682 btrfs_end_transaction(trans
, rc
->extent_root
);
3686 ret
= find_next_extent(trans
, rc
, path
, &key
);
3692 rc
->extents_found
++;
3694 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
3695 struct btrfs_extent_item
);
3696 item_size
= btrfs_item_size_nr(path
->nodes
[0], path
->slots
[0]);
3697 if (item_size
>= sizeof(*ei
)) {
3698 flags
= btrfs_extent_flags(path
->nodes
[0], ei
);
3699 ret
= check_extent_flags(flags
);
3703 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3705 int path_change
= 0;
3708 sizeof(struct btrfs_extent_item_v0
));
3709 ret
= get_ref_objectid_v0(rc
, path
, &key
, &ref_owner
,
3711 if (ref_owner
< BTRFS_FIRST_FREE_OBJECTID
)
3712 flags
= BTRFS_EXTENT_FLAG_TREE_BLOCK
;
3714 flags
= BTRFS_EXTENT_FLAG_DATA
;
3717 btrfs_release_path(rc
->extent_root
, path
);
3719 path
->search_commit_root
= 1;
3720 path
->skip_locking
= 1;
3721 ret
= btrfs_search_slot(NULL
, rc
->extent_root
,
3734 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
3735 ret
= add_tree_block(rc
, &key
, path
, &blocks
);
3736 } else if (rc
->stage
== UPDATE_DATA_PTRS
&&
3737 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
3738 ret
= add_data_references(rc
, &key
, path
, &blocks
);
3740 btrfs_release_path(rc
->extent_root
, path
);
3748 if (!RB_EMPTY_ROOT(&blocks
)) {
3749 ret
= relocate_tree_blocks(trans
, rc
, &blocks
);
3751 if (ret
!= -EAGAIN
) {
3755 rc
->extents_found
--;
3756 rc
->search_start
= key
.objectid
;
3760 ret
= btrfs_block_rsv_check(trans
, rc
->extent_root
,
3761 rc
->block_rsv
, 0, 5);
3763 if (ret
!= -EAGAIN
) {
3768 rc
->commit_transaction
= 1;
3771 if (rc
->commit_transaction
) {
3772 rc
->commit_transaction
= 0;
3773 ret
= btrfs_commit_transaction(trans
, rc
->extent_root
);
3776 nr
= trans
->blocks_used
;
3777 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
3778 btrfs_btree_balance_dirty(rc
->extent_root
, nr
);
3782 if (rc
->stage
== MOVE_DATA_EXTENTS
&&
3783 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
3784 rc
->found_file_extent
= 1;
3785 ret
= relocate_data_extent(rc
->data_inode
,
3786 &key
, &rc
->cluster
);
3793 if (trans
&& progress
&& err
== -ENOSPC
) {
3794 ret
= btrfs_force_chunk_alloc(trans
, rc
->extent_root
,
3795 rc
->block_group
->flags
);
3803 btrfs_release_path(rc
->extent_root
, path
);
3804 clear_extent_bits(&rc
->processed_blocks
, 0, (u64
)-1, EXTENT_DIRTY
,
3808 nr
= trans
->blocks_used
;
3809 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
3810 btrfs_btree_balance_dirty(rc
->extent_root
, nr
);
3814 ret
= relocate_file_extent_cluster(rc
->data_inode
,
3820 rc
->create_reloc_tree
= 0;
3821 set_reloc_control(rc
);
3823 backref_cache_cleanup(&rc
->backref_cache
);
3824 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
3826 err
= prepare_to_merge(rc
, err
);
3828 merge_reloc_roots(rc
);
3830 rc
->merge_reloc_tree
= 0;
3831 unset_reloc_control(rc
);
3832 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
3834 /* get rid of pinned extents */
3835 trans
= btrfs_join_transaction(rc
->extent_root
, 1);
3837 err
= PTR_ERR(trans
);
3839 btrfs_commit_transaction(trans
, rc
->extent_root
);
3841 btrfs_free_block_rsv(rc
->extent_root
, rc
->block_rsv
);
3842 btrfs_free_path(path
);
3846 static int __insert_orphan_inode(struct btrfs_trans_handle
*trans
,
3847 struct btrfs_root
*root
, u64 objectid
)
3849 struct btrfs_path
*path
;
3850 struct btrfs_inode_item
*item
;
3851 struct extent_buffer
*leaf
;
3854 path
= btrfs_alloc_path();
3858 ret
= btrfs_insert_empty_inode(trans
, root
, path
, objectid
);
3862 leaf
= path
->nodes
[0];
3863 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_inode_item
);
3864 memset_extent_buffer(leaf
, 0, (unsigned long)item
, sizeof(*item
));
3865 btrfs_set_inode_generation(leaf
, item
, 1);
3866 btrfs_set_inode_size(leaf
, item
, 0);
3867 btrfs_set_inode_mode(leaf
, item
, S_IFREG
| 0600);
3868 btrfs_set_inode_flags(leaf
, item
, BTRFS_INODE_NOCOMPRESS
|
3869 BTRFS_INODE_PREALLOC
);
3870 btrfs_mark_buffer_dirty(leaf
);
3871 btrfs_release_path(root
, path
);
3873 btrfs_free_path(path
);
3878 * helper to create inode for data relocation.
3879 * the inode is in data relocation tree and its link count is 0
3881 static noinline_for_stack
3882 struct inode
*create_reloc_inode(struct btrfs_fs_info
*fs_info
,
3883 struct btrfs_block_group_cache
*group
)
3885 struct inode
*inode
= NULL
;
3886 struct btrfs_trans_handle
*trans
;
3887 struct btrfs_root
*root
;
3888 struct btrfs_key key
;
3890 u64 objectid
= BTRFS_FIRST_FREE_OBJECTID
;
3893 root
= read_fs_root(fs_info
, BTRFS_DATA_RELOC_TREE_OBJECTID
);
3895 return ERR_CAST(root
);
3897 trans
= btrfs_start_transaction(root
, 6);
3899 return ERR_CAST(trans
);
3901 err
= btrfs_find_free_objectid(root
, &objectid
);
3905 err
= __insert_orphan_inode(trans
, root
, objectid
);
3908 key
.objectid
= objectid
;
3909 key
.type
= BTRFS_INODE_ITEM_KEY
;
3911 inode
= btrfs_iget(root
->fs_info
->sb
, &key
, root
, NULL
);
3912 BUG_ON(IS_ERR(inode
) || is_bad_inode(inode
));
3913 BTRFS_I(inode
)->index_cnt
= group
->key
.objectid
;
3915 err
= btrfs_orphan_add(trans
, inode
);
3917 nr
= trans
->blocks_used
;
3918 btrfs_end_transaction(trans
, root
);
3919 btrfs_btree_balance_dirty(root
, nr
);
3923 inode
= ERR_PTR(err
);
3928 static struct reloc_control
*alloc_reloc_control(void)
3930 struct reloc_control
*rc
;
3932 rc
= kzalloc(sizeof(*rc
), GFP_NOFS
);
3936 INIT_LIST_HEAD(&rc
->reloc_roots
);
3937 backref_cache_init(&rc
->backref_cache
);
3938 mapping_tree_init(&rc
->reloc_root_tree
);
3939 extent_io_tree_init(&rc
->processed_blocks
, NULL
, GFP_NOFS
);
3944 * function to relocate all extents in a block group.
3946 int btrfs_relocate_block_group(struct btrfs_root
*extent_root
, u64 group_start
)
3948 struct btrfs_fs_info
*fs_info
= extent_root
->fs_info
;
3949 struct reloc_control
*rc
;
3950 struct inode
*inode
;
3951 struct btrfs_path
*path
;
3956 rc
= alloc_reloc_control();
3960 rc
->extent_root
= extent_root
;
3962 rc
->block_group
= btrfs_lookup_block_group(fs_info
, group_start
);
3963 BUG_ON(!rc
->block_group
);
3965 if (!rc
->block_group
->ro
) {
3966 ret
= btrfs_set_block_group_ro(extent_root
, rc
->block_group
);
3974 path
= btrfs_alloc_path();
3980 inode
= lookup_free_space_inode(fs_info
->tree_root
, rc
->block_group
,
3982 btrfs_free_path(path
);
3985 ret
= delete_block_group_cache(fs_info
, inode
, 0);
3987 ret
= PTR_ERR(inode
);
3989 if (ret
&& ret
!= -ENOENT
) {
3994 rc
->data_inode
= create_reloc_inode(fs_info
, rc
->block_group
);
3995 if (IS_ERR(rc
->data_inode
)) {
3996 err
= PTR_ERR(rc
->data_inode
);
3997 rc
->data_inode
= NULL
;
4001 printk(KERN_INFO
"btrfs: relocating block group %llu flags %llu\n",
4002 (unsigned long long)rc
->block_group
->key
.objectid
,
4003 (unsigned long long)rc
->block_group
->flags
);
4005 btrfs_start_delalloc_inodes(fs_info
->tree_root
, 0);
4006 btrfs_wait_ordered_extents(fs_info
->tree_root
, 0, 0);
4009 mutex_lock(&fs_info
->cleaner_mutex
);
4011 btrfs_clean_old_snapshots(fs_info
->tree_root
);
4012 ret
= relocate_block_group(rc
);
4014 mutex_unlock(&fs_info
->cleaner_mutex
);
4020 if (rc
->extents_found
== 0)
4023 printk(KERN_INFO
"btrfs: found %llu extents\n",
4024 (unsigned long long)rc
->extents_found
);
4026 if (rc
->stage
== MOVE_DATA_EXTENTS
&& rc
->found_file_extent
) {
4027 btrfs_wait_ordered_range(rc
->data_inode
, 0, (u64
)-1);
4028 invalidate_mapping_pages(rc
->data_inode
->i_mapping
,
4030 rc
->stage
= UPDATE_DATA_PTRS
;
4034 filemap_write_and_wait_range(fs_info
->btree_inode
->i_mapping
,
4035 rc
->block_group
->key
.objectid
,
4036 rc
->block_group
->key
.objectid
+
4037 rc
->block_group
->key
.offset
- 1);
4039 WARN_ON(rc
->block_group
->pinned
> 0);
4040 WARN_ON(rc
->block_group
->reserved
> 0);
4041 WARN_ON(btrfs_block_group_used(&rc
->block_group
->item
) > 0);
4044 btrfs_set_block_group_rw(extent_root
, rc
->block_group
);
4045 iput(rc
->data_inode
);
4046 btrfs_put_block_group(rc
->block_group
);
4051 static noinline_for_stack
int mark_garbage_root(struct btrfs_root
*root
)
4053 struct btrfs_trans_handle
*trans
;
4056 trans
= btrfs_start_transaction(root
->fs_info
->tree_root
, 0);
4057 BUG_ON(IS_ERR(trans
));
4059 memset(&root
->root_item
.drop_progress
, 0,
4060 sizeof(root
->root_item
.drop_progress
));
4061 root
->root_item
.drop_level
= 0;
4062 btrfs_set_root_refs(&root
->root_item
, 0);
4063 ret
= btrfs_update_root(trans
, root
->fs_info
->tree_root
,
4064 &root
->root_key
, &root
->root_item
);
4067 ret
= btrfs_end_transaction(trans
, root
->fs_info
->tree_root
);
4073 * recover relocation interrupted by system crash.
4075 * this function resumes merging reloc trees with corresponding fs trees.
4076 * this is important for keeping the sharing of tree blocks
4078 int btrfs_recover_relocation(struct btrfs_root
*root
)
4080 LIST_HEAD(reloc_roots
);
4081 struct btrfs_key key
;
4082 struct btrfs_root
*fs_root
;
4083 struct btrfs_root
*reloc_root
;
4084 struct btrfs_path
*path
;
4085 struct extent_buffer
*leaf
;
4086 struct reloc_control
*rc
= NULL
;
4087 struct btrfs_trans_handle
*trans
;
4091 path
= btrfs_alloc_path();
4095 key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
4096 key
.type
= BTRFS_ROOT_ITEM_KEY
;
4097 key
.offset
= (u64
)-1;
4100 ret
= btrfs_search_slot(NULL
, root
->fs_info
->tree_root
, &key
,
4107 if (path
->slots
[0] == 0)
4111 leaf
= path
->nodes
[0];
4112 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
4113 btrfs_release_path(root
->fs_info
->tree_root
, path
);
4115 if (key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
||
4116 key
.type
!= BTRFS_ROOT_ITEM_KEY
)
4119 reloc_root
= btrfs_read_fs_root_no_radix(root
, &key
);
4120 if (IS_ERR(reloc_root
)) {
4121 err
= PTR_ERR(reloc_root
);
4125 list_add(&reloc_root
->root_list
, &reloc_roots
);
4127 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
4128 fs_root
= read_fs_root(root
->fs_info
,
4129 reloc_root
->root_key
.offset
);
4130 if (IS_ERR(fs_root
)) {
4131 ret
= PTR_ERR(fs_root
);
4132 if (ret
!= -ENOENT
) {
4136 mark_garbage_root(reloc_root
);
4140 if (key
.offset
== 0)
4145 btrfs_release_path(root
->fs_info
->tree_root
, path
);
4147 if (list_empty(&reloc_roots
))
4150 rc
= alloc_reloc_control();
4156 rc
->extent_root
= root
->fs_info
->extent_root
;
4158 set_reloc_control(rc
);
4160 trans
= btrfs_join_transaction(rc
->extent_root
, 1);
4161 if (IS_ERR(trans
)) {
4162 unset_reloc_control(rc
);
4163 err
= PTR_ERR(trans
);
4167 rc
->merge_reloc_tree
= 1;
4169 while (!list_empty(&reloc_roots
)) {
4170 reloc_root
= list_entry(reloc_roots
.next
,
4171 struct btrfs_root
, root_list
);
4172 list_del(&reloc_root
->root_list
);
4174 if (btrfs_root_refs(&reloc_root
->root_item
) == 0) {
4175 list_add_tail(&reloc_root
->root_list
,
4180 fs_root
= read_fs_root(root
->fs_info
,
4181 reloc_root
->root_key
.offset
);
4182 BUG_ON(IS_ERR(fs_root
));
4184 __add_reloc_root(reloc_root
);
4185 fs_root
->reloc_root
= reloc_root
;
4188 btrfs_commit_transaction(trans
, rc
->extent_root
);
4190 merge_reloc_roots(rc
);
4192 unset_reloc_control(rc
);
4194 trans
= btrfs_join_transaction(rc
->extent_root
, 1);
4196 err
= PTR_ERR(trans
);
4198 btrfs_commit_transaction(trans
, rc
->extent_root
);
4202 while (!list_empty(&reloc_roots
)) {
4203 reloc_root
= list_entry(reloc_roots
.next
,
4204 struct btrfs_root
, root_list
);
4205 list_del(&reloc_root
->root_list
);
4206 free_extent_buffer(reloc_root
->node
);
4207 free_extent_buffer(reloc_root
->commit_root
);
4210 btrfs_free_path(path
);
4213 /* cleanup orphan inode in data relocation tree */
4214 fs_root
= read_fs_root(root
->fs_info
,
4215 BTRFS_DATA_RELOC_TREE_OBJECTID
);
4216 if (IS_ERR(fs_root
))
4217 err
= PTR_ERR(fs_root
);
4219 err
= btrfs_orphan_cleanup(fs_root
);
4225 * helper to add ordered checksum for data relocation.
4227 * cloning checksum properly handles the nodatasum extents.
4228 * it also saves CPU time to re-calculate the checksum.
4230 int btrfs_reloc_clone_csums(struct inode
*inode
, u64 file_pos
, u64 len
)
4232 struct btrfs_ordered_sum
*sums
;
4233 struct btrfs_sector_sum
*sector_sum
;
4234 struct btrfs_ordered_extent
*ordered
;
4235 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
4241 ordered
= btrfs_lookup_ordered_extent(inode
, file_pos
);
4242 BUG_ON(ordered
->file_offset
!= file_pos
|| ordered
->len
!= len
);
4244 disk_bytenr
= file_pos
+ BTRFS_I(inode
)->index_cnt
;
4245 ret
= btrfs_lookup_csums_range(root
->fs_info
->csum_root
, disk_bytenr
,
4246 disk_bytenr
+ len
- 1, &list
);
4248 while (!list_empty(&list
)) {
4249 sums
= list_entry(list
.next
, struct btrfs_ordered_sum
, list
);
4250 list_del_init(&sums
->list
);
4252 sector_sum
= sums
->sums
;
4253 sums
->bytenr
= ordered
->start
;
4256 while (offset
< sums
->len
) {
4257 sector_sum
->bytenr
+= ordered
->start
- disk_bytenr
;
4259 offset
+= root
->sectorsize
;
4262 btrfs_add_ordered_sum(inode
, ordered
, sums
);
4264 btrfs_put_ordered_extent(ordered
);
4268 void btrfs_reloc_cow_block(struct btrfs_trans_handle
*trans
,
4269 struct btrfs_root
*root
, struct extent_buffer
*buf
,
4270 struct extent_buffer
*cow
)
4272 struct reloc_control
*rc
;
4273 struct backref_node
*node
;
4278 rc
= root
->fs_info
->reloc_ctl
;
4282 BUG_ON(rc
->stage
== UPDATE_DATA_PTRS
&&
4283 root
->root_key
.objectid
== BTRFS_DATA_RELOC_TREE_OBJECTID
);
4285 level
= btrfs_header_level(buf
);
4286 if (btrfs_header_generation(buf
) <=
4287 btrfs_root_last_snapshot(&root
->root_item
))
4290 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
&&
4291 rc
->create_reloc_tree
) {
4292 WARN_ON(!first_cow
&& level
== 0);
4294 node
= rc
->backref_cache
.path
[level
];
4295 BUG_ON(node
->bytenr
!= buf
->start
&&
4296 node
->new_bytenr
!= buf
->start
);
4298 drop_node_buffer(node
);
4299 extent_buffer_get(cow
);
4301 node
->new_bytenr
= cow
->start
;
4303 if (!node
->pending
) {
4304 list_move_tail(&node
->list
,
4305 &rc
->backref_cache
.pending
[level
]);
4310 __mark_block_processed(rc
, node
);
4312 if (first_cow
&& level
> 0)
4313 rc
->nodes_relocated
+= buf
->len
;
4316 if (level
== 0 && first_cow
&& rc
->stage
== UPDATE_DATA_PTRS
) {
4317 ret
= replace_file_extents(trans
, rc
, root
, cow
);
4323 * called before creating snapshot. it calculates metadata reservation
4324 * requried for relocating tree blocks in the snapshot
4326 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle
*trans
,
4327 struct btrfs_pending_snapshot
*pending
,
4328 u64
*bytes_to_reserve
)
4330 struct btrfs_root
*root
;
4331 struct reloc_control
*rc
;
4333 root
= pending
->root
;
4334 if (!root
->reloc_root
)
4337 rc
= root
->fs_info
->reloc_ctl
;
4338 if (!rc
->merge_reloc_tree
)
4341 root
= root
->reloc_root
;
4342 BUG_ON(btrfs_root_refs(&root
->root_item
) == 0);
4344 * relocation is in the stage of merging trees. the space
4345 * used by merging a reloc tree is twice the size of
4346 * relocated tree nodes in the worst case. half for cowing
4347 * the reloc tree, half for cowing the fs tree. the space
4348 * used by cowing the reloc tree will be freed after the
4349 * tree is dropped. if we create snapshot, cowing the fs
4350 * tree may use more space than it frees. so we need
4351 * reserve extra space.
4353 *bytes_to_reserve
+= rc
->nodes_relocated
;
4357 * called after snapshot is created. migrate block reservation
4358 * and create reloc root for the newly created snapshot
4360 void btrfs_reloc_post_snapshot(struct btrfs_trans_handle
*trans
,
4361 struct btrfs_pending_snapshot
*pending
)
4363 struct btrfs_root
*root
= pending
->root
;
4364 struct btrfs_root
*reloc_root
;
4365 struct btrfs_root
*new_root
;
4366 struct reloc_control
*rc
;
4369 if (!root
->reloc_root
)
4372 rc
= root
->fs_info
->reloc_ctl
;
4373 rc
->merging_rsv_size
+= rc
->nodes_relocated
;
4375 if (rc
->merge_reloc_tree
) {
4376 ret
= btrfs_block_rsv_migrate(&pending
->block_rsv
,
4378 rc
->nodes_relocated
);
4382 new_root
= pending
->snap
;
4383 reloc_root
= create_reloc_root(trans
, root
->reloc_root
,
4384 new_root
->root_key
.objectid
);
4386 __add_reloc_root(reloc_root
);
4387 new_root
->reloc_root
= reloc_root
;
4389 if (rc
->create_reloc_tree
) {
4390 ret
= clone_backref_node(trans
, rc
, root
, reloc_root
);