2 * Copyright (C) 2009 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
27 #include "transaction.h"
30 #include "btrfs_inode.h"
31 #include "async-thread.h"
32 #include "free-space-cache.h"
33 #include "inode-map.h"
36 * backref_node, mapping_node and tree_block start with this
39 struct rb_node rb_node
;
44 * present a tree block in the backref cache
47 struct rb_node rb_node
;
51 /* objectid of tree block owner, can be not uptodate */
53 /* link to pending, changed or detached list */
54 struct list_head list
;
55 /* list of upper level blocks reference this block */
56 struct list_head upper
;
57 /* list of child blocks in the cache */
58 struct list_head lower
;
59 /* NULL if this node is not tree root */
60 struct btrfs_root
*root
;
61 /* extent buffer got by COW the block */
62 struct extent_buffer
*eb
;
63 /* level of tree block */
65 /* is the block in non-reference counted tree */
66 unsigned int cowonly
:1;
67 /* 1 if no child node in the cache */
68 unsigned int lowest
:1;
69 /* is the extent buffer locked */
70 unsigned int locked
:1;
71 /* has the block been processed */
72 unsigned int processed
:1;
73 /* have backrefs of this block been checked */
74 unsigned int checked
:1;
76 * 1 if corresponding block has been cowed but some upper
77 * level block pointers may not point to the new location
79 unsigned int pending
:1;
81 * 1 if the backref node isn't connected to any other
84 unsigned int detached
:1;
88 * present a block pointer in the backref cache
91 struct list_head list
[2];
92 struct backref_node
*node
[2];
98 struct backref_cache
{
99 /* red black tree of all backref nodes in the cache */
100 struct rb_root rb_root
;
101 /* for passing backref nodes to btrfs_reloc_cow_block */
102 struct backref_node
*path
[BTRFS_MAX_LEVEL
];
104 * list of blocks that have been cowed but some block
105 * pointers in upper level blocks may not reflect the
108 struct list_head pending
[BTRFS_MAX_LEVEL
];
109 /* list of backref nodes with no child node */
110 struct list_head leaves
;
111 /* list of blocks that have been cowed in current transaction */
112 struct list_head changed
;
113 /* list of detached backref node. */
114 struct list_head detached
;
123 * map address of tree root to tree
125 struct mapping_node
{
126 struct rb_node rb_node
;
131 struct mapping_tree
{
132 struct rb_root rb_root
;
137 * present a tree block to process
140 struct rb_node rb_node
;
142 struct btrfs_key key
;
143 unsigned int level
:8;
144 unsigned int key_ready
:1;
147 #define MAX_EXTENTS 128
149 struct file_extent_cluster
{
152 u64 boundary
[MAX_EXTENTS
];
156 struct reloc_control
{
157 /* block group to relocate */
158 struct btrfs_block_group_cache
*block_group
;
160 struct btrfs_root
*extent_root
;
161 /* inode for moving data */
162 struct inode
*data_inode
;
164 struct btrfs_block_rsv
*block_rsv
;
166 struct backref_cache backref_cache
;
168 struct file_extent_cluster cluster
;
169 /* tree blocks have been processed */
170 struct extent_io_tree processed_blocks
;
171 /* map start of tree root to corresponding reloc tree */
172 struct mapping_tree reloc_root_tree
;
173 /* list of reloc trees */
174 struct list_head reloc_roots
;
175 /* size of metadata reservation for merging reloc trees */
176 u64 merging_rsv_size
;
177 /* size of relocated tree nodes */
183 unsigned int stage
:8;
184 unsigned int create_reloc_tree
:1;
185 unsigned int merge_reloc_tree
:1;
186 unsigned int found_file_extent
:1;
187 unsigned int commit_transaction
:1;
190 /* stages of data relocation */
191 #define MOVE_DATA_EXTENTS 0
192 #define UPDATE_DATA_PTRS 1
194 static void remove_backref_node(struct backref_cache
*cache
,
195 struct backref_node
*node
);
196 static void __mark_block_processed(struct reloc_control
*rc
,
197 struct backref_node
*node
);
199 static void mapping_tree_init(struct mapping_tree
*tree
)
201 tree
->rb_root
= RB_ROOT
;
202 spin_lock_init(&tree
->lock
);
205 static void backref_cache_init(struct backref_cache
*cache
)
208 cache
->rb_root
= RB_ROOT
;
209 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++)
210 INIT_LIST_HEAD(&cache
->pending
[i
]);
211 INIT_LIST_HEAD(&cache
->changed
);
212 INIT_LIST_HEAD(&cache
->detached
);
213 INIT_LIST_HEAD(&cache
->leaves
);
216 static void backref_cache_cleanup(struct backref_cache
*cache
)
218 struct backref_node
*node
;
221 while (!list_empty(&cache
->detached
)) {
222 node
= list_entry(cache
->detached
.next
,
223 struct backref_node
, list
);
224 remove_backref_node(cache
, node
);
227 while (!list_empty(&cache
->leaves
)) {
228 node
= list_entry(cache
->leaves
.next
,
229 struct backref_node
, lower
);
230 remove_backref_node(cache
, node
);
233 cache
->last_trans
= 0;
235 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++)
236 BUG_ON(!list_empty(&cache
->pending
[i
]));
237 BUG_ON(!list_empty(&cache
->changed
));
238 BUG_ON(!list_empty(&cache
->detached
));
239 BUG_ON(!RB_EMPTY_ROOT(&cache
->rb_root
));
240 BUG_ON(cache
->nr_nodes
);
241 BUG_ON(cache
->nr_edges
);
244 static struct backref_node
*alloc_backref_node(struct backref_cache
*cache
)
246 struct backref_node
*node
;
248 node
= kzalloc(sizeof(*node
), GFP_NOFS
);
250 INIT_LIST_HEAD(&node
->list
);
251 INIT_LIST_HEAD(&node
->upper
);
252 INIT_LIST_HEAD(&node
->lower
);
253 RB_CLEAR_NODE(&node
->rb_node
);
259 static void free_backref_node(struct backref_cache
*cache
,
260 struct backref_node
*node
)
268 static struct backref_edge
*alloc_backref_edge(struct backref_cache
*cache
)
270 struct backref_edge
*edge
;
272 edge
= kzalloc(sizeof(*edge
), GFP_NOFS
);
278 static void free_backref_edge(struct backref_cache
*cache
,
279 struct backref_edge
*edge
)
287 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 bytenr
,
288 struct rb_node
*node
)
290 struct rb_node
**p
= &root
->rb_node
;
291 struct rb_node
*parent
= NULL
;
292 struct tree_entry
*entry
;
296 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
298 if (bytenr
< entry
->bytenr
)
300 else if (bytenr
> entry
->bytenr
)
306 rb_link_node(node
, parent
, p
);
307 rb_insert_color(node
, root
);
311 static struct rb_node
*tree_search(struct rb_root
*root
, u64 bytenr
)
313 struct rb_node
*n
= root
->rb_node
;
314 struct tree_entry
*entry
;
317 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
319 if (bytenr
< entry
->bytenr
)
321 else if (bytenr
> entry
->bytenr
)
329 static void backref_tree_panic(struct rb_node
*rb_node
, int errno
, u64 bytenr
)
332 struct btrfs_fs_info
*fs_info
= NULL
;
333 struct backref_node
*bnode
= rb_entry(rb_node
, struct backref_node
,
336 fs_info
= bnode
->root
->fs_info
;
337 btrfs_panic(fs_info
, errno
, "Inconsistency in backref cache "
338 "found at offset %llu\n", bytenr
);
342 * walk up backref nodes until reach node presents tree root
344 static struct backref_node
*walk_up_backref(struct backref_node
*node
,
345 struct backref_edge
*edges
[],
348 struct backref_edge
*edge
;
351 while (!list_empty(&node
->upper
)) {
352 edge
= list_entry(node
->upper
.next
,
353 struct backref_edge
, list
[LOWER
]);
355 node
= edge
->node
[UPPER
];
357 BUG_ON(node
->detached
);
363 * walk down backref nodes to find start of next reference path
365 static struct backref_node
*walk_down_backref(struct backref_edge
*edges
[],
368 struct backref_edge
*edge
;
369 struct backref_node
*lower
;
373 edge
= edges
[idx
- 1];
374 lower
= edge
->node
[LOWER
];
375 if (list_is_last(&edge
->list
[LOWER
], &lower
->upper
)) {
379 edge
= list_entry(edge
->list
[LOWER
].next
,
380 struct backref_edge
, list
[LOWER
]);
381 edges
[idx
- 1] = edge
;
383 return edge
->node
[UPPER
];
389 static void unlock_node_buffer(struct backref_node
*node
)
392 btrfs_tree_unlock(node
->eb
);
397 static void drop_node_buffer(struct backref_node
*node
)
400 unlock_node_buffer(node
);
401 free_extent_buffer(node
->eb
);
406 static void drop_backref_node(struct backref_cache
*tree
,
407 struct backref_node
*node
)
409 BUG_ON(!list_empty(&node
->upper
));
411 drop_node_buffer(node
);
412 list_del(&node
->list
);
413 list_del(&node
->lower
);
414 if (!RB_EMPTY_NODE(&node
->rb_node
))
415 rb_erase(&node
->rb_node
, &tree
->rb_root
);
416 free_backref_node(tree
, node
);
420 * remove a backref node from the backref cache
422 static void remove_backref_node(struct backref_cache
*cache
,
423 struct backref_node
*node
)
425 struct backref_node
*upper
;
426 struct backref_edge
*edge
;
431 BUG_ON(!node
->lowest
&& !node
->detached
);
432 while (!list_empty(&node
->upper
)) {
433 edge
= list_entry(node
->upper
.next
, struct backref_edge
,
435 upper
= edge
->node
[UPPER
];
436 list_del(&edge
->list
[LOWER
]);
437 list_del(&edge
->list
[UPPER
]);
438 free_backref_edge(cache
, edge
);
440 if (RB_EMPTY_NODE(&upper
->rb_node
)) {
441 BUG_ON(!list_empty(&node
->upper
));
442 drop_backref_node(cache
, node
);
448 * add the node to leaf node list if no other
449 * child block cached.
451 if (list_empty(&upper
->lower
)) {
452 list_add_tail(&upper
->lower
, &cache
->leaves
);
457 drop_backref_node(cache
, node
);
460 static void update_backref_node(struct backref_cache
*cache
,
461 struct backref_node
*node
, u64 bytenr
)
463 struct rb_node
*rb_node
;
464 rb_erase(&node
->rb_node
, &cache
->rb_root
);
465 node
->bytenr
= bytenr
;
466 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
, &node
->rb_node
);
468 backref_tree_panic(rb_node
, -EEXIST
, bytenr
);
472 * update backref cache after a transaction commit
474 static int update_backref_cache(struct btrfs_trans_handle
*trans
,
475 struct backref_cache
*cache
)
477 struct backref_node
*node
;
480 if (cache
->last_trans
== 0) {
481 cache
->last_trans
= trans
->transid
;
485 if (cache
->last_trans
== trans
->transid
)
489 * detached nodes are used to avoid unnecessary backref
490 * lookup. transaction commit changes the extent tree.
491 * so the detached nodes are no longer useful.
493 while (!list_empty(&cache
->detached
)) {
494 node
= list_entry(cache
->detached
.next
,
495 struct backref_node
, list
);
496 remove_backref_node(cache
, node
);
499 while (!list_empty(&cache
->changed
)) {
500 node
= list_entry(cache
->changed
.next
,
501 struct backref_node
, list
);
502 list_del_init(&node
->list
);
503 BUG_ON(node
->pending
);
504 update_backref_node(cache
, node
, node
->new_bytenr
);
508 * some nodes can be left in the pending list if there were
509 * errors during processing the pending nodes.
511 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
512 list_for_each_entry(node
, &cache
->pending
[level
], list
) {
513 BUG_ON(!node
->pending
);
514 if (node
->bytenr
== node
->new_bytenr
)
516 update_backref_node(cache
, node
, node
->new_bytenr
);
520 cache
->last_trans
= 0;
525 static int should_ignore_root(struct btrfs_root
*root
)
527 struct btrfs_root
*reloc_root
;
532 reloc_root
= root
->reloc_root
;
536 if (btrfs_root_last_snapshot(&reloc_root
->root_item
) ==
537 root
->fs_info
->running_transaction
->transid
- 1)
540 * if there is reloc tree and it was created in previous
541 * transaction backref lookup can find the reloc tree,
542 * so backref node for the fs tree root is useless for
548 * find reloc tree by address of tree root
550 static struct btrfs_root
*find_reloc_root(struct reloc_control
*rc
,
553 struct rb_node
*rb_node
;
554 struct mapping_node
*node
;
555 struct btrfs_root
*root
= NULL
;
557 spin_lock(&rc
->reloc_root_tree
.lock
);
558 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
, bytenr
);
560 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
561 root
= (struct btrfs_root
*)node
->data
;
563 spin_unlock(&rc
->reloc_root_tree
.lock
);
567 static int is_cowonly_root(u64 root_objectid
)
569 if (root_objectid
== BTRFS_ROOT_TREE_OBJECTID
||
570 root_objectid
== BTRFS_EXTENT_TREE_OBJECTID
||
571 root_objectid
== BTRFS_CHUNK_TREE_OBJECTID
||
572 root_objectid
== BTRFS_DEV_TREE_OBJECTID
||
573 root_objectid
== BTRFS_TREE_LOG_OBJECTID
||
574 root_objectid
== BTRFS_CSUM_TREE_OBJECTID
)
579 static struct btrfs_root
*read_fs_root(struct btrfs_fs_info
*fs_info
,
582 struct btrfs_key key
;
584 key
.objectid
= root_objectid
;
585 key
.type
= BTRFS_ROOT_ITEM_KEY
;
586 if (is_cowonly_root(root_objectid
))
589 key
.offset
= (u64
)-1;
591 return btrfs_get_fs_root(fs_info
, &key
, false);
594 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
595 static noinline_for_stack
596 struct btrfs_root
*find_tree_root(struct reloc_control
*rc
,
597 struct extent_buffer
*leaf
,
598 struct btrfs_extent_ref_v0
*ref0
)
600 struct btrfs_root
*root
;
601 u64 root_objectid
= btrfs_ref_root_v0(leaf
, ref0
);
602 u64 generation
= btrfs_ref_generation_v0(leaf
, ref0
);
604 BUG_ON(root_objectid
== BTRFS_TREE_RELOC_OBJECTID
);
606 root
= read_fs_root(rc
->extent_root
->fs_info
, root_objectid
);
607 BUG_ON(IS_ERR(root
));
609 if (root
->ref_cows
&&
610 generation
!= btrfs_root_generation(&root
->root_item
))
617 static noinline_for_stack
618 int find_inline_backref(struct extent_buffer
*leaf
, int slot
,
619 unsigned long *ptr
, unsigned long *end
)
621 struct btrfs_key key
;
622 struct btrfs_extent_item
*ei
;
623 struct btrfs_tree_block_info
*bi
;
626 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
628 item_size
= btrfs_item_size_nr(leaf
, slot
);
629 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
630 if (item_size
< sizeof(*ei
)) {
631 WARN_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
635 ei
= btrfs_item_ptr(leaf
, slot
, struct btrfs_extent_item
);
636 WARN_ON(!(btrfs_extent_flags(leaf
, ei
) &
637 BTRFS_EXTENT_FLAG_TREE_BLOCK
));
639 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
640 item_size
<= sizeof(*ei
) + sizeof(*bi
)) {
641 WARN_ON(item_size
< sizeof(*ei
) + sizeof(*bi
));
644 if (key
.type
== BTRFS_METADATA_ITEM_KEY
&&
645 item_size
<= sizeof(*ei
)) {
646 WARN_ON(item_size
< sizeof(*ei
));
650 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
) {
651 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
652 *ptr
= (unsigned long)(bi
+ 1);
654 *ptr
= (unsigned long)(ei
+ 1);
656 *end
= (unsigned long)ei
+ item_size
;
661 * build backref tree for a given tree block. root of the backref tree
662 * corresponds the tree block, leaves of the backref tree correspond
663 * roots of b-trees that reference the tree block.
665 * the basic idea of this function is check backrefs of a given block
666 * to find upper level blocks that refernece the block, and then check
667 * bakcrefs of these upper level blocks recursively. the recursion stop
668 * when tree root is reached or backrefs for the block is cached.
670 * NOTE: if we find backrefs for a block are cached, we know backrefs
671 * for all upper level blocks that directly/indirectly reference the
672 * block are also cached.
674 static noinline_for_stack
675 struct backref_node
*build_backref_tree(struct reloc_control
*rc
,
676 struct btrfs_key
*node_key
,
677 int level
, u64 bytenr
)
679 struct backref_cache
*cache
= &rc
->backref_cache
;
680 struct btrfs_path
*path1
;
681 struct btrfs_path
*path2
;
682 struct extent_buffer
*eb
;
683 struct btrfs_root
*root
;
684 struct backref_node
*cur
;
685 struct backref_node
*upper
;
686 struct backref_node
*lower
;
687 struct backref_node
*node
= NULL
;
688 struct backref_node
*exist
= NULL
;
689 struct backref_edge
*edge
;
690 struct rb_node
*rb_node
;
691 struct btrfs_key key
;
699 bool need_check
= true;
701 path1
= btrfs_alloc_path();
702 path2
= btrfs_alloc_path();
703 if (!path1
|| !path2
) {
710 node
= alloc_backref_node(cache
);
716 node
->bytenr
= bytenr
;
723 key
.objectid
= cur
->bytenr
;
724 key
.type
= BTRFS_METADATA_ITEM_KEY
;
725 key
.offset
= (u64
)-1;
727 path1
->search_commit_root
= 1;
728 path1
->skip_locking
= 1;
729 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path1
,
735 BUG_ON(!ret
|| !path1
->slots
[0]);
739 WARN_ON(cur
->checked
);
740 if (!list_empty(&cur
->upper
)) {
742 * the backref was added previously when processing
743 * backref of type BTRFS_TREE_BLOCK_REF_KEY
745 BUG_ON(!list_is_singular(&cur
->upper
));
746 edge
= list_entry(cur
->upper
.next
, struct backref_edge
,
748 BUG_ON(!list_empty(&edge
->list
[UPPER
]));
749 exist
= edge
->node
[UPPER
];
751 * add the upper level block to pending list if we need
755 list_add_tail(&edge
->list
[UPPER
], &list
);
762 eb
= path1
->nodes
[0];
765 if (path1
->slots
[0] >= btrfs_header_nritems(eb
)) {
766 ret
= btrfs_next_leaf(rc
->extent_root
, path1
);
773 eb
= path1
->nodes
[0];
776 btrfs_item_key_to_cpu(eb
, &key
, path1
->slots
[0]);
777 if (key
.objectid
!= cur
->bytenr
) {
782 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
||
783 key
.type
== BTRFS_METADATA_ITEM_KEY
) {
784 ret
= find_inline_backref(eb
, path1
->slots
[0],
792 /* update key for inline back ref */
793 struct btrfs_extent_inline_ref
*iref
;
794 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
795 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
796 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
797 WARN_ON(key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
&&
798 key
.type
!= BTRFS_SHARED_BLOCK_REF_KEY
);
802 ((key
.type
== BTRFS_TREE_BLOCK_REF_KEY
&&
803 exist
->owner
== key
.offset
) ||
804 (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
&&
805 exist
->bytenr
== key
.offset
))) {
810 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
811 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
||
812 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
813 if (key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
814 struct btrfs_extent_ref_v0
*ref0
;
815 ref0
= btrfs_item_ptr(eb
, path1
->slots
[0],
816 struct btrfs_extent_ref_v0
);
817 if (key
.objectid
== key
.offset
) {
818 root
= find_tree_root(rc
, eb
, ref0
);
819 if (root
&& !should_ignore_root(root
))
822 list_add(&cur
->list
, &useless
);
825 if (is_cowonly_root(btrfs_ref_root_v0(eb
,
830 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
831 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
) {
833 if (key
.objectid
== key
.offset
) {
835 * only root blocks of reloc trees use
836 * backref of this type.
838 root
= find_reloc_root(rc
, cur
->bytenr
);
844 edge
= alloc_backref_edge(cache
);
849 rb_node
= tree_search(&cache
->rb_root
, key
.offset
);
851 upper
= alloc_backref_node(cache
);
853 free_backref_edge(cache
, edge
);
857 upper
->bytenr
= key
.offset
;
858 upper
->level
= cur
->level
+ 1;
860 * backrefs for the upper level block isn't
861 * cached, add the block to pending list
863 list_add_tail(&edge
->list
[UPPER
], &list
);
865 upper
= rb_entry(rb_node
, struct backref_node
,
867 BUG_ON(!upper
->checked
);
868 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
870 list_add_tail(&edge
->list
[LOWER
], &cur
->upper
);
871 edge
->node
[LOWER
] = cur
;
872 edge
->node
[UPPER
] = upper
;
875 } else if (key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
) {
879 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
880 root
= read_fs_root(rc
->extent_root
->fs_info
, key
.offset
);
889 if (btrfs_root_level(&root
->root_item
) == cur
->level
) {
891 BUG_ON(btrfs_root_bytenr(&root
->root_item
) !=
893 if (should_ignore_root(root
))
894 list_add(&cur
->list
, &useless
);
900 level
= cur
->level
+ 1;
903 * searching the tree to find upper level blocks
904 * reference the block.
906 path2
->search_commit_root
= 1;
907 path2
->skip_locking
= 1;
908 path2
->lowest_level
= level
;
909 ret
= btrfs_search_slot(NULL
, root
, node_key
, path2
, 0, 0);
910 path2
->lowest_level
= 0;
915 if (ret
> 0 && path2
->slots
[level
] > 0)
916 path2
->slots
[level
]--;
918 eb
= path2
->nodes
[level
];
919 WARN_ON(btrfs_node_blockptr(eb
, path2
->slots
[level
]) !=
924 for (; level
< BTRFS_MAX_LEVEL
; level
++) {
925 if (!path2
->nodes
[level
]) {
926 BUG_ON(btrfs_root_bytenr(&root
->root_item
) !=
928 if (should_ignore_root(root
))
929 list_add(&lower
->list
, &useless
);
935 edge
= alloc_backref_edge(cache
);
941 eb
= path2
->nodes
[level
];
942 rb_node
= tree_search(&cache
->rb_root
, eb
->start
);
944 upper
= alloc_backref_node(cache
);
946 free_backref_edge(cache
, edge
);
950 upper
->bytenr
= eb
->start
;
951 upper
->owner
= btrfs_header_owner(eb
);
952 upper
->level
= lower
->level
+ 1;
957 * if we know the block isn't shared
958 * we can void checking its backrefs.
960 if (btrfs_block_can_be_shared(root
, eb
))
966 * add the block to pending list if we
967 * need check its backrefs, we only do this once
968 * while walking up a tree as we will catch
969 * anything else later on.
971 if (!upper
->checked
&& need_check
) {
973 list_add_tail(&edge
->list
[UPPER
],
976 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
978 upper
= rb_entry(rb_node
, struct backref_node
,
980 BUG_ON(!upper
->checked
);
981 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
983 upper
->owner
= btrfs_header_owner(eb
);
985 list_add_tail(&edge
->list
[LOWER
], &lower
->upper
);
986 edge
->node
[LOWER
] = lower
;
987 edge
->node
[UPPER
] = upper
;
994 btrfs_release_path(path2
);
997 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
1007 btrfs_release_path(path1
);
1012 /* the pending list isn't empty, take the first block to process */
1013 if (!list_empty(&list
)) {
1014 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1015 list_del_init(&edge
->list
[UPPER
]);
1016 cur
= edge
->node
[UPPER
];
1021 * everything goes well, connect backref nodes and insert backref nodes
1024 BUG_ON(!node
->checked
);
1025 cowonly
= node
->cowonly
;
1027 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
,
1030 backref_tree_panic(rb_node
, -EEXIST
, node
->bytenr
);
1031 list_add_tail(&node
->lower
, &cache
->leaves
);
1034 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
])
1035 list_add_tail(&edge
->list
[UPPER
], &list
);
1037 while (!list_empty(&list
)) {
1038 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1039 list_del_init(&edge
->list
[UPPER
]);
1040 upper
= edge
->node
[UPPER
];
1041 if (upper
->detached
) {
1042 list_del(&edge
->list
[LOWER
]);
1043 lower
= edge
->node
[LOWER
];
1044 free_backref_edge(cache
, edge
);
1045 if (list_empty(&lower
->upper
))
1046 list_add(&lower
->list
, &useless
);
1050 if (!RB_EMPTY_NODE(&upper
->rb_node
)) {
1051 if (upper
->lowest
) {
1052 list_del_init(&upper
->lower
);
1056 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1060 BUG_ON(!upper
->checked
);
1061 BUG_ON(cowonly
!= upper
->cowonly
);
1063 rb_node
= tree_insert(&cache
->rb_root
, upper
->bytenr
,
1066 backref_tree_panic(rb_node
, -EEXIST
,
1070 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1072 list_for_each_entry(edge
, &upper
->upper
, list
[LOWER
])
1073 list_add_tail(&edge
->list
[UPPER
], &list
);
1076 * process useless backref nodes. backref nodes for tree leaves
1077 * are deleted from the cache. backref nodes for upper level
1078 * tree blocks are left in the cache to avoid unnecessary backref
1081 while (!list_empty(&useless
)) {
1082 upper
= list_entry(useless
.next
, struct backref_node
, list
);
1083 list_del_init(&upper
->list
);
1084 BUG_ON(!list_empty(&upper
->upper
));
1087 if (upper
->lowest
) {
1088 list_del_init(&upper
->lower
);
1091 while (!list_empty(&upper
->lower
)) {
1092 edge
= list_entry(upper
->lower
.next
,
1093 struct backref_edge
, list
[UPPER
]);
1094 list_del(&edge
->list
[UPPER
]);
1095 list_del(&edge
->list
[LOWER
]);
1096 lower
= edge
->node
[LOWER
];
1097 free_backref_edge(cache
, edge
);
1099 if (list_empty(&lower
->upper
))
1100 list_add(&lower
->list
, &useless
);
1102 __mark_block_processed(rc
, upper
);
1103 if (upper
->level
> 0) {
1104 list_add(&upper
->list
, &cache
->detached
);
1105 upper
->detached
= 1;
1107 rb_erase(&upper
->rb_node
, &cache
->rb_root
);
1108 free_backref_node(cache
, upper
);
1112 btrfs_free_path(path1
);
1113 btrfs_free_path(path2
);
1115 while (!list_empty(&useless
)) {
1116 lower
= list_entry(useless
.next
,
1117 struct backref_node
, upper
);
1118 list_del_init(&lower
->upper
);
1121 INIT_LIST_HEAD(&list
);
1123 if (RB_EMPTY_NODE(&upper
->rb_node
)) {
1124 list_splice_tail(&upper
->upper
, &list
);
1125 free_backref_node(cache
, upper
);
1128 if (list_empty(&list
))
1131 edge
= list_entry(list
.next
, struct backref_edge
,
1133 list_del(&edge
->list
[LOWER
]);
1134 upper
= edge
->node
[UPPER
];
1135 free_backref_edge(cache
, edge
);
1137 return ERR_PTR(err
);
1139 BUG_ON(node
&& node
->detached
);
1144 * helper to add backref node for the newly created snapshot.
1145 * the backref node is created by cloning backref node that
1146 * corresponds to root of source tree
1148 static int clone_backref_node(struct btrfs_trans_handle
*trans
,
1149 struct reloc_control
*rc
,
1150 struct btrfs_root
*src
,
1151 struct btrfs_root
*dest
)
1153 struct btrfs_root
*reloc_root
= src
->reloc_root
;
1154 struct backref_cache
*cache
= &rc
->backref_cache
;
1155 struct backref_node
*node
= NULL
;
1156 struct backref_node
*new_node
;
1157 struct backref_edge
*edge
;
1158 struct backref_edge
*new_edge
;
1159 struct rb_node
*rb_node
;
1161 if (cache
->last_trans
> 0)
1162 update_backref_cache(trans
, cache
);
1164 rb_node
= tree_search(&cache
->rb_root
, src
->commit_root
->start
);
1166 node
= rb_entry(rb_node
, struct backref_node
, rb_node
);
1170 BUG_ON(node
->new_bytenr
!= reloc_root
->node
->start
);
1174 rb_node
= tree_search(&cache
->rb_root
,
1175 reloc_root
->commit_root
->start
);
1177 node
= rb_entry(rb_node
, struct backref_node
,
1179 BUG_ON(node
->detached
);
1186 new_node
= alloc_backref_node(cache
);
1190 new_node
->bytenr
= dest
->node
->start
;
1191 new_node
->level
= node
->level
;
1192 new_node
->lowest
= node
->lowest
;
1193 new_node
->checked
= 1;
1194 new_node
->root
= dest
;
1196 if (!node
->lowest
) {
1197 list_for_each_entry(edge
, &node
->lower
, list
[UPPER
]) {
1198 new_edge
= alloc_backref_edge(cache
);
1202 new_edge
->node
[UPPER
] = new_node
;
1203 new_edge
->node
[LOWER
] = edge
->node
[LOWER
];
1204 list_add_tail(&new_edge
->list
[UPPER
],
1208 list_add_tail(&new_node
->lower
, &cache
->leaves
);
1211 rb_node
= tree_insert(&cache
->rb_root
, new_node
->bytenr
,
1212 &new_node
->rb_node
);
1214 backref_tree_panic(rb_node
, -EEXIST
, new_node
->bytenr
);
1216 if (!new_node
->lowest
) {
1217 list_for_each_entry(new_edge
, &new_node
->lower
, list
[UPPER
]) {
1218 list_add_tail(&new_edge
->list
[LOWER
],
1219 &new_edge
->node
[LOWER
]->upper
);
1224 while (!list_empty(&new_node
->lower
)) {
1225 new_edge
= list_entry(new_node
->lower
.next
,
1226 struct backref_edge
, list
[UPPER
]);
1227 list_del(&new_edge
->list
[UPPER
]);
1228 free_backref_edge(cache
, new_edge
);
1230 free_backref_node(cache
, new_node
);
1235 * helper to add 'address of tree root -> reloc tree' mapping
1237 static int __must_check
__add_reloc_root(struct btrfs_root
*root
)
1239 struct rb_node
*rb_node
;
1240 struct mapping_node
*node
;
1241 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1243 node
= kmalloc(sizeof(*node
), GFP_NOFS
);
1247 node
->bytenr
= root
->node
->start
;
1250 spin_lock(&rc
->reloc_root_tree
.lock
);
1251 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1252 node
->bytenr
, &node
->rb_node
);
1253 spin_unlock(&rc
->reloc_root_tree
.lock
);
1255 btrfs_panic(root
->fs_info
, -EEXIST
, "Duplicate root found "
1256 "for start=%llu while inserting into relocation "
1257 "tree\n", node
->bytenr
);
1262 list_add_tail(&root
->root_list
, &rc
->reloc_roots
);
1267 * helper to update/delete the 'address of tree root -> reloc tree'
1270 static int __update_reloc_root(struct btrfs_root
*root
, int del
)
1272 struct rb_node
*rb_node
;
1273 struct mapping_node
*node
= NULL
;
1274 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1276 spin_lock(&rc
->reloc_root_tree
.lock
);
1277 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
,
1278 root
->commit_root
->start
);
1280 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
1281 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
1283 spin_unlock(&rc
->reloc_root_tree
.lock
);
1287 BUG_ON((struct btrfs_root
*)node
->data
!= root
);
1290 spin_lock(&rc
->reloc_root_tree
.lock
);
1291 node
->bytenr
= root
->node
->start
;
1292 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1293 node
->bytenr
, &node
->rb_node
);
1294 spin_unlock(&rc
->reloc_root_tree
.lock
);
1296 backref_tree_panic(rb_node
, -EEXIST
, node
->bytenr
);
1298 spin_lock(&root
->fs_info
->trans_lock
);
1299 list_del_init(&root
->root_list
);
1300 spin_unlock(&root
->fs_info
->trans_lock
);
1306 static struct btrfs_root
*create_reloc_root(struct btrfs_trans_handle
*trans
,
1307 struct btrfs_root
*root
, u64 objectid
)
1309 struct btrfs_root
*reloc_root
;
1310 struct extent_buffer
*eb
;
1311 struct btrfs_root_item
*root_item
;
1312 struct btrfs_key root_key
;
1316 root_item
= kmalloc(sizeof(*root_item
), GFP_NOFS
);
1319 root_key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
1320 root_key
.type
= BTRFS_ROOT_ITEM_KEY
;
1321 root_key
.offset
= objectid
;
1323 if (root
->root_key
.objectid
== objectid
) {
1324 /* called by btrfs_init_reloc_root */
1325 ret
= btrfs_copy_root(trans
, root
, root
->commit_root
, &eb
,
1326 BTRFS_TREE_RELOC_OBJECTID
);
1329 last_snap
= btrfs_root_last_snapshot(&root
->root_item
);
1330 btrfs_set_root_last_snapshot(&root
->root_item
,
1331 trans
->transid
- 1);
1334 * called by btrfs_reloc_post_snapshot_hook.
1335 * the source tree is a reloc tree, all tree blocks
1336 * modified after it was created have RELOC flag
1337 * set in their headers. so it's OK to not update
1338 * the 'last_snapshot'.
1340 ret
= btrfs_copy_root(trans
, root
, root
->node
, &eb
,
1341 BTRFS_TREE_RELOC_OBJECTID
);
1345 memcpy(root_item
, &root
->root_item
, sizeof(*root_item
));
1346 btrfs_set_root_bytenr(root_item
, eb
->start
);
1347 btrfs_set_root_level(root_item
, btrfs_header_level(eb
));
1348 btrfs_set_root_generation(root_item
, trans
->transid
);
1350 if (root
->root_key
.objectid
== objectid
) {
1351 btrfs_set_root_refs(root_item
, 0);
1352 memset(&root_item
->drop_progress
, 0,
1353 sizeof(struct btrfs_disk_key
));
1354 root_item
->drop_level
= 0;
1356 * abuse rtransid, it is safe because it is impossible to
1357 * receive data into a relocation tree.
1359 btrfs_set_root_rtransid(root_item
, last_snap
);
1360 btrfs_set_root_otransid(root_item
, trans
->transid
);
1363 btrfs_tree_unlock(eb
);
1364 free_extent_buffer(eb
);
1366 ret
= btrfs_insert_root(trans
, root
->fs_info
->tree_root
,
1367 &root_key
, root_item
);
1371 reloc_root
= btrfs_read_fs_root(root
->fs_info
->tree_root
, &root_key
);
1372 BUG_ON(IS_ERR(reloc_root
));
1373 reloc_root
->last_trans
= trans
->transid
;
1378 * create reloc tree for a given fs tree. reloc tree is just a
1379 * snapshot of the fs tree with special root objectid.
1381 int btrfs_init_reloc_root(struct btrfs_trans_handle
*trans
,
1382 struct btrfs_root
*root
)
1384 struct btrfs_root
*reloc_root
;
1385 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1386 struct btrfs_block_rsv
*rsv
;
1390 if (root
->reloc_root
) {
1391 reloc_root
= root
->reloc_root
;
1392 reloc_root
->last_trans
= trans
->transid
;
1396 if (!rc
|| !rc
->create_reloc_tree
||
1397 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1400 if (!trans
->reloc_reserved
) {
1401 rsv
= trans
->block_rsv
;
1402 trans
->block_rsv
= rc
->block_rsv
;
1405 reloc_root
= create_reloc_root(trans
, root
, root
->root_key
.objectid
);
1407 trans
->block_rsv
= rsv
;
1409 ret
= __add_reloc_root(reloc_root
);
1411 root
->reloc_root
= reloc_root
;
1416 * update root item of reloc tree
1418 int btrfs_update_reloc_root(struct btrfs_trans_handle
*trans
,
1419 struct btrfs_root
*root
)
1421 struct btrfs_root
*reloc_root
;
1422 struct btrfs_root_item
*root_item
;
1426 if (!root
->reloc_root
)
1429 reloc_root
= root
->reloc_root
;
1430 root_item
= &reloc_root
->root_item
;
1432 if (root
->fs_info
->reloc_ctl
->merge_reloc_tree
&&
1433 btrfs_root_refs(root_item
) == 0) {
1434 root
->reloc_root
= NULL
;
1438 __update_reloc_root(reloc_root
, del
);
1440 if (reloc_root
->commit_root
!= reloc_root
->node
) {
1441 btrfs_set_root_node(root_item
, reloc_root
->node
);
1442 free_extent_buffer(reloc_root
->commit_root
);
1443 reloc_root
->commit_root
= btrfs_root_node(reloc_root
);
1446 ret
= btrfs_update_root(trans
, root
->fs_info
->tree_root
,
1447 &reloc_root
->root_key
, root_item
);
1455 * helper to find first cached inode with inode number >= objectid
1458 static struct inode
*find_next_inode(struct btrfs_root
*root
, u64 objectid
)
1460 struct rb_node
*node
;
1461 struct rb_node
*prev
;
1462 struct btrfs_inode
*entry
;
1463 struct inode
*inode
;
1465 spin_lock(&root
->inode_lock
);
1467 node
= root
->inode_tree
.rb_node
;
1471 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1473 if (objectid
< btrfs_ino(&entry
->vfs_inode
))
1474 node
= node
->rb_left
;
1475 else if (objectid
> btrfs_ino(&entry
->vfs_inode
))
1476 node
= node
->rb_right
;
1482 entry
= rb_entry(prev
, struct btrfs_inode
, rb_node
);
1483 if (objectid
<= btrfs_ino(&entry
->vfs_inode
)) {
1487 prev
= rb_next(prev
);
1491 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1492 inode
= igrab(&entry
->vfs_inode
);
1494 spin_unlock(&root
->inode_lock
);
1498 objectid
= btrfs_ino(&entry
->vfs_inode
) + 1;
1499 if (cond_resched_lock(&root
->inode_lock
))
1502 node
= rb_next(node
);
1504 spin_unlock(&root
->inode_lock
);
1508 static int in_block_group(u64 bytenr
,
1509 struct btrfs_block_group_cache
*block_group
)
1511 if (bytenr
>= block_group
->key
.objectid
&&
1512 bytenr
< block_group
->key
.objectid
+ block_group
->key
.offset
)
1518 * get new location of data
1520 static int get_new_location(struct inode
*reloc_inode
, u64
*new_bytenr
,
1521 u64 bytenr
, u64 num_bytes
)
1523 struct btrfs_root
*root
= BTRFS_I(reloc_inode
)->root
;
1524 struct btrfs_path
*path
;
1525 struct btrfs_file_extent_item
*fi
;
1526 struct extent_buffer
*leaf
;
1529 path
= btrfs_alloc_path();
1533 bytenr
-= BTRFS_I(reloc_inode
)->index_cnt
;
1534 ret
= btrfs_lookup_file_extent(NULL
, root
, path
, btrfs_ino(reloc_inode
),
1543 leaf
= path
->nodes
[0];
1544 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
1545 struct btrfs_file_extent_item
);
1547 BUG_ON(btrfs_file_extent_offset(leaf
, fi
) ||
1548 btrfs_file_extent_compression(leaf
, fi
) ||
1549 btrfs_file_extent_encryption(leaf
, fi
) ||
1550 btrfs_file_extent_other_encoding(leaf
, fi
));
1552 if (num_bytes
!= btrfs_file_extent_disk_num_bytes(leaf
, fi
)) {
1557 *new_bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1560 btrfs_free_path(path
);
1565 * update file extent items in the tree leaf to point to
1566 * the new locations.
1568 static noinline_for_stack
1569 int replace_file_extents(struct btrfs_trans_handle
*trans
,
1570 struct reloc_control
*rc
,
1571 struct btrfs_root
*root
,
1572 struct extent_buffer
*leaf
)
1574 struct btrfs_key key
;
1575 struct btrfs_file_extent_item
*fi
;
1576 struct inode
*inode
= NULL
;
1588 if (rc
->stage
!= UPDATE_DATA_PTRS
)
1591 /* reloc trees always use full backref */
1592 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1593 parent
= leaf
->start
;
1597 nritems
= btrfs_header_nritems(leaf
);
1598 for (i
= 0; i
< nritems
; i
++) {
1600 btrfs_item_key_to_cpu(leaf
, &key
, i
);
1601 if (key
.type
!= BTRFS_EXTENT_DATA_KEY
)
1603 fi
= btrfs_item_ptr(leaf
, i
, struct btrfs_file_extent_item
);
1604 if (btrfs_file_extent_type(leaf
, fi
) ==
1605 BTRFS_FILE_EXTENT_INLINE
)
1607 bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1608 num_bytes
= btrfs_file_extent_disk_num_bytes(leaf
, fi
);
1611 if (!in_block_group(bytenr
, rc
->block_group
))
1615 * if we are modifying block in fs tree, wait for readpage
1616 * to complete and drop the extent cache
1618 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
) {
1620 inode
= find_next_inode(root
, key
.objectid
);
1622 } else if (inode
&& btrfs_ino(inode
) < key
.objectid
) {
1623 btrfs_add_delayed_iput(inode
);
1624 inode
= find_next_inode(root
, key
.objectid
);
1626 if (inode
&& btrfs_ino(inode
) == key
.objectid
) {
1628 btrfs_file_extent_num_bytes(leaf
, fi
);
1629 WARN_ON(!IS_ALIGNED(key
.offset
,
1631 WARN_ON(!IS_ALIGNED(end
, root
->sectorsize
));
1633 ret
= try_lock_extent(&BTRFS_I(inode
)->io_tree
,
1638 btrfs_drop_extent_cache(inode
, key
.offset
, end
,
1640 unlock_extent(&BTRFS_I(inode
)->io_tree
,
1645 ret
= get_new_location(rc
->data_inode
, &new_bytenr
,
1649 * Don't have to abort since we've not changed anything
1650 * in the file extent yet.
1655 btrfs_set_file_extent_disk_bytenr(leaf
, fi
, new_bytenr
);
1658 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
1659 ret
= btrfs_inc_extent_ref(trans
, root
, new_bytenr
,
1661 btrfs_header_owner(leaf
),
1662 key
.objectid
, key
.offset
, 1);
1664 btrfs_abort_transaction(trans
, root
, ret
);
1668 ret
= btrfs_free_extent(trans
, root
, bytenr
, num_bytes
,
1669 parent
, btrfs_header_owner(leaf
),
1670 key
.objectid
, key
.offset
, 1);
1672 btrfs_abort_transaction(trans
, root
, ret
);
1677 btrfs_mark_buffer_dirty(leaf
);
1679 btrfs_add_delayed_iput(inode
);
1683 static noinline_for_stack
1684 int memcmp_node_keys(struct extent_buffer
*eb
, int slot
,
1685 struct btrfs_path
*path
, int level
)
1687 struct btrfs_disk_key key1
;
1688 struct btrfs_disk_key key2
;
1689 btrfs_node_key(eb
, &key1
, slot
);
1690 btrfs_node_key(path
->nodes
[level
], &key2
, path
->slots
[level
]);
1691 return memcmp(&key1
, &key2
, sizeof(key1
));
1695 * try to replace tree blocks in fs tree with the new blocks
1696 * in reloc tree. tree blocks haven't been modified since the
1697 * reloc tree was create can be replaced.
1699 * if a block was replaced, level of the block + 1 is returned.
1700 * if no block got replaced, 0 is returned. if there are other
1701 * errors, a negative error number is returned.
1703 static noinline_for_stack
1704 int replace_path(struct btrfs_trans_handle
*trans
,
1705 struct btrfs_root
*dest
, struct btrfs_root
*src
,
1706 struct btrfs_path
*path
, struct btrfs_key
*next_key
,
1707 int lowest_level
, int max_level
)
1709 struct extent_buffer
*eb
;
1710 struct extent_buffer
*parent
;
1711 struct btrfs_key key
;
1723 BUG_ON(src
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
);
1724 BUG_ON(dest
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
);
1726 last_snapshot
= btrfs_root_last_snapshot(&src
->root_item
);
1728 slot
= path
->slots
[lowest_level
];
1729 btrfs_node_key_to_cpu(path
->nodes
[lowest_level
], &key
, slot
);
1731 eb
= btrfs_lock_root_node(dest
);
1732 btrfs_set_lock_blocking(eb
);
1733 level
= btrfs_header_level(eb
);
1735 if (level
< lowest_level
) {
1736 btrfs_tree_unlock(eb
);
1737 free_extent_buffer(eb
);
1742 ret
= btrfs_cow_block(trans
, dest
, eb
, NULL
, 0, &eb
);
1745 btrfs_set_lock_blocking(eb
);
1748 next_key
->objectid
= (u64
)-1;
1749 next_key
->type
= (u8
)-1;
1750 next_key
->offset
= (u64
)-1;
1755 level
= btrfs_header_level(parent
);
1756 BUG_ON(level
< lowest_level
);
1758 ret
= btrfs_bin_search(parent
, &key
, level
, &slot
);
1759 if (ret
&& slot
> 0)
1762 if (next_key
&& slot
+ 1 < btrfs_header_nritems(parent
))
1763 btrfs_node_key_to_cpu(parent
, next_key
, slot
+ 1);
1765 old_bytenr
= btrfs_node_blockptr(parent
, slot
);
1766 blocksize
= btrfs_level_size(dest
, level
- 1);
1767 old_ptr_gen
= btrfs_node_ptr_generation(parent
, slot
);
1769 if (level
<= max_level
) {
1770 eb
= path
->nodes
[level
];
1771 new_bytenr
= btrfs_node_blockptr(eb
,
1772 path
->slots
[level
]);
1773 new_ptr_gen
= btrfs_node_ptr_generation(eb
,
1774 path
->slots
[level
]);
1780 if (WARN_ON(new_bytenr
> 0 && new_bytenr
== old_bytenr
)) {
1785 if (new_bytenr
== 0 || old_ptr_gen
> last_snapshot
||
1786 memcmp_node_keys(parent
, slot
, path
, level
)) {
1787 if (level
<= lowest_level
) {
1792 eb
= read_tree_block(dest
, old_bytenr
, blocksize
,
1794 if (!eb
|| !extent_buffer_uptodate(eb
)) {
1795 ret
= (!eb
) ? -ENOMEM
: -EIO
;
1796 free_extent_buffer(eb
);
1799 btrfs_tree_lock(eb
);
1801 ret
= btrfs_cow_block(trans
, dest
, eb
, parent
,
1805 btrfs_set_lock_blocking(eb
);
1807 btrfs_tree_unlock(parent
);
1808 free_extent_buffer(parent
);
1815 btrfs_tree_unlock(parent
);
1816 free_extent_buffer(parent
);
1821 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
1822 path
->slots
[level
]);
1823 btrfs_release_path(path
);
1825 path
->lowest_level
= level
;
1826 ret
= btrfs_search_slot(trans
, src
, &key
, path
, 0, 1);
1827 path
->lowest_level
= 0;
1831 * swap blocks in fs tree and reloc tree.
1833 btrfs_set_node_blockptr(parent
, slot
, new_bytenr
);
1834 btrfs_set_node_ptr_generation(parent
, slot
, new_ptr_gen
);
1835 btrfs_mark_buffer_dirty(parent
);
1837 btrfs_set_node_blockptr(path
->nodes
[level
],
1838 path
->slots
[level
], old_bytenr
);
1839 btrfs_set_node_ptr_generation(path
->nodes
[level
],
1840 path
->slots
[level
], old_ptr_gen
);
1841 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
1843 ret
= btrfs_inc_extent_ref(trans
, src
, old_bytenr
, blocksize
,
1844 path
->nodes
[level
]->start
,
1845 src
->root_key
.objectid
, level
- 1, 0,
1848 ret
= btrfs_inc_extent_ref(trans
, dest
, new_bytenr
, blocksize
,
1849 0, dest
->root_key
.objectid
, level
- 1,
1853 ret
= btrfs_free_extent(trans
, src
, new_bytenr
, blocksize
,
1854 path
->nodes
[level
]->start
,
1855 src
->root_key
.objectid
, level
- 1, 0,
1859 ret
= btrfs_free_extent(trans
, dest
, old_bytenr
, blocksize
,
1860 0, dest
->root_key
.objectid
, level
- 1,
1864 btrfs_unlock_up_safe(path
, 0);
1869 btrfs_tree_unlock(parent
);
1870 free_extent_buffer(parent
);
1875 * helper to find next relocated block in reloc tree
1877 static noinline_for_stack
1878 int walk_up_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1881 struct extent_buffer
*eb
;
1886 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1888 for (i
= 0; i
< *level
; i
++) {
1889 free_extent_buffer(path
->nodes
[i
]);
1890 path
->nodes
[i
] = NULL
;
1893 for (i
= *level
; i
< BTRFS_MAX_LEVEL
&& path
->nodes
[i
]; i
++) {
1894 eb
= path
->nodes
[i
];
1895 nritems
= btrfs_header_nritems(eb
);
1896 while (path
->slots
[i
] + 1 < nritems
) {
1898 if (btrfs_node_ptr_generation(eb
, path
->slots
[i
]) <=
1905 free_extent_buffer(path
->nodes
[i
]);
1906 path
->nodes
[i
] = NULL
;
1912 * walk down reloc tree to find relocated block of lowest level
1914 static noinline_for_stack
1915 int walk_down_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1918 struct extent_buffer
*eb
= NULL
;
1926 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1928 for (i
= *level
; i
> 0; i
--) {
1929 eb
= path
->nodes
[i
];
1930 nritems
= btrfs_header_nritems(eb
);
1931 while (path
->slots
[i
] < nritems
) {
1932 ptr_gen
= btrfs_node_ptr_generation(eb
, path
->slots
[i
]);
1933 if (ptr_gen
> last_snapshot
)
1937 if (path
->slots
[i
] >= nritems
) {
1948 bytenr
= btrfs_node_blockptr(eb
, path
->slots
[i
]);
1949 blocksize
= btrfs_level_size(root
, i
- 1);
1950 eb
= read_tree_block(root
, bytenr
, blocksize
, ptr_gen
);
1951 if (!eb
|| !extent_buffer_uptodate(eb
)) {
1952 free_extent_buffer(eb
);
1955 BUG_ON(btrfs_header_level(eb
) != i
- 1);
1956 path
->nodes
[i
- 1] = eb
;
1957 path
->slots
[i
- 1] = 0;
1963 * invalidate extent cache for file extents whose key in range of
1964 * [min_key, max_key)
1966 static int invalidate_extent_cache(struct btrfs_root
*root
,
1967 struct btrfs_key
*min_key
,
1968 struct btrfs_key
*max_key
)
1970 struct inode
*inode
= NULL
;
1975 objectid
= min_key
->objectid
;
1980 if (objectid
> max_key
->objectid
)
1983 inode
= find_next_inode(root
, objectid
);
1986 ino
= btrfs_ino(inode
);
1988 if (ino
> max_key
->objectid
) {
1994 if (!S_ISREG(inode
->i_mode
))
1997 if (unlikely(min_key
->objectid
== ino
)) {
1998 if (min_key
->type
> BTRFS_EXTENT_DATA_KEY
)
2000 if (min_key
->type
< BTRFS_EXTENT_DATA_KEY
)
2003 start
= min_key
->offset
;
2004 WARN_ON(!IS_ALIGNED(start
, root
->sectorsize
));
2010 if (unlikely(max_key
->objectid
== ino
)) {
2011 if (max_key
->type
< BTRFS_EXTENT_DATA_KEY
)
2013 if (max_key
->type
> BTRFS_EXTENT_DATA_KEY
) {
2016 if (max_key
->offset
== 0)
2018 end
= max_key
->offset
;
2019 WARN_ON(!IS_ALIGNED(end
, root
->sectorsize
));
2026 /* the lock_extent waits for readpage to complete */
2027 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2028 btrfs_drop_extent_cache(inode
, start
, end
, 1);
2029 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2034 static int find_next_key(struct btrfs_path
*path
, int level
,
2035 struct btrfs_key
*key
)
2038 while (level
< BTRFS_MAX_LEVEL
) {
2039 if (!path
->nodes
[level
])
2041 if (path
->slots
[level
] + 1 <
2042 btrfs_header_nritems(path
->nodes
[level
])) {
2043 btrfs_node_key_to_cpu(path
->nodes
[level
], key
,
2044 path
->slots
[level
] + 1);
2053 * merge the relocated tree blocks in reloc tree with corresponding
2056 static noinline_for_stack
int merge_reloc_root(struct reloc_control
*rc
,
2057 struct btrfs_root
*root
)
2059 LIST_HEAD(inode_list
);
2060 struct btrfs_key key
;
2061 struct btrfs_key next_key
;
2062 struct btrfs_trans_handle
*trans
= NULL
;
2063 struct btrfs_root
*reloc_root
;
2064 struct btrfs_root_item
*root_item
;
2065 struct btrfs_path
*path
;
2066 struct extent_buffer
*leaf
;
2074 path
= btrfs_alloc_path();
2079 reloc_root
= root
->reloc_root
;
2080 root_item
= &reloc_root
->root_item
;
2082 if (btrfs_disk_key_objectid(&root_item
->drop_progress
) == 0) {
2083 level
= btrfs_root_level(root_item
);
2084 extent_buffer_get(reloc_root
->node
);
2085 path
->nodes
[level
] = reloc_root
->node
;
2086 path
->slots
[level
] = 0;
2088 btrfs_disk_key_to_cpu(&key
, &root_item
->drop_progress
);
2090 level
= root_item
->drop_level
;
2092 path
->lowest_level
= level
;
2093 ret
= btrfs_search_slot(NULL
, reloc_root
, &key
, path
, 0, 0);
2094 path
->lowest_level
= 0;
2096 btrfs_free_path(path
);
2100 btrfs_node_key_to_cpu(path
->nodes
[level
], &next_key
,
2101 path
->slots
[level
]);
2102 WARN_ON(memcmp(&key
, &next_key
, sizeof(key
)));
2104 btrfs_unlock_up_safe(path
, 0);
2107 min_reserved
= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2108 memset(&next_key
, 0, sizeof(next_key
));
2111 ret
= btrfs_block_rsv_refill(root
, rc
->block_rsv
, min_reserved
,
2112 BTRFS_RESERVE_FLUSH_ALL
);
2117 trans
= btrfs_start_transaction(root
, 0);
2118 if (IS_ERR(trans
)) {
2119 err
= PTR_ERR(trans
);
2123 trans
->block_rsv
= rc
->block_rsv
;
2128 ret
= walk_down_reloc_tree(reloc_root
, path
, &level
);
2136 if (!find_next_key(path
, level
, &key
) &&
2137 btrfs_comp_cpu_keys(&next_key
, &key
) >= 0) {
2140 ret
= replace_path(trans
, root
, reloc_root
, path
,
2141 &next_key
, level
, max_level
);
2150 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
2151 path
->slots
[level
]);
2155 ret
= walk_up_reloc_tree(reloc_root
, path
, &level
);
2161 * save the merging progress in the drop_progress.
2162 * this is OK since root refs == 1 in this case.
2164 btrfs_node_key(path
->nodes
[level
], &root_item
->drop_progress
,
2165 path
->slots
[level
]);
2166 root_item
->drop_level
= level
;
2168 btrfs_end_transaction_throttle(trans
, root
);
2171 btrfs_btree_balance_dirty(root
);
2173 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2174 invalidate_extent_cache(root
, &key
, &next_key
);
2178 * handle the case only one block in the fs tree need to be
2179 * relocated and the block is tree root.
2181 leaf
= btrfs_lock_root_node(root
);
2182 ret
= btrfs_cow_block(trans
, root
, leaf
, NULL
, 0, &leaf
);
2183 btrfs_tree_unlock(leaf
);
2184 free_extent_buffer(leaf
);
2188 btrfs_free_path(path
);
2191 memset(&root_item
->drop_progress
, 0,
2192 sizeof(root_item
->drop_progress
));
2193 root_item
->drop_level
= 0;
2194 btrfs_set_root_refs(root_item
, 0);
2195 btrfs_update_reloc_root(trans
, root
);
2199 btrfs_end_transaction_throttle(trans
, root
);
2201 btrfs_btree_balance_dirty(root
);
2203 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2204 invalidate_extent_cache(root
, &key
, &next_key
);
2209 static noinline_for_stack
2210 int prepare_to_merge(struct reloc_control
*rc
, int err
)
2212 struct btrfs_root
*root
= rc
->extent_root
;
2213 struct btrfs_root
*reloc_root
;
2214 struct btrfs_trans_handle
*trans
;
2215 LIST_HEAD(reloc_roots
);
2219 mutex_lock(&root
->fs_info
->reloc_mutex
);
2220 rc
->merging_rsv_size
+= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2221 rc
->merging_rsv_size
+= rc
->nodes_relocated
* 2;
2222 mutex_unlock(&root
->fs_info
->reloc_mutex
);
2226 num_bytes
= rc
->merging_rsv_size
;
2227 ret
= btrfs_block_rsv_add(root
, rc
->block_rsv
, num_bytes
,
2228 BTRFS_RESERVE_FLUSH_ALL
);
2233 trans
= btrfs_join_transaction(rc
->extent_root
);
2234 if (IS_ERR(trans
)) {
2236 btrfs_block_rsv_release(rc
->extent_root
,
2237 rc
->block_rsv
, num_bytes
);
2238 return PTR_ERR(trans
);
2242 if (num_bytes
!= rc
->merging_rsv_size
) {
2243 btrfs_end_transaction(trans
, rc
->extent_root
);
2244 btrfs_block_rsv_release(rc
->extent_root
,
2245 rc
->block_rsv
, num_bytes
);
2250 rc
->merge_reloc_tree
= 1;
2252 while (!list_empty(&rc
->reloc_roots
)) {
2253 reloc_root
= list_entry(rc
->reloc_roots
.next
,
2254 struct btrfs_root
, root_list
);
2255 list_del_init(&reloc_root
->root_list
);
2257 root
= read_fs_root(reloc_root
->fs_info
,
2258 reloc_root
->root_key
.offset
);
2259 BUG_ON(IS_ERR(root
));
2260 BUG_ON(root
->reloc_root
!= reloc_root
);
2263 * set reference count to 1, so btrfs_recover_relocation
2264 * knows it should resumes merging
2267 btrfs_set_root_refs(&reloc_root
->root_item
, 1);
2268 btrfs_update_reloc_root(trans
, root
);
2270 list_add(&reloc_root
->root_list
, &reloc_roots
);
2273 list_splice(&reloc_roots
, &rc
->reloc_roots
);
2276 btrfs_commit_transaction(trans
, rc
->extent_root
);
2278 btrfs_end_transaction(trans
, rc
->extent_root
);
2282 static noinline_for_stack
2283 void free_reloc_roots(struct list_head
*list
)
2285 struct btrfs_root
*reloc_root
;
2287 while (!list_empty(list
)) {
2288 reloc_root
= list_entry(list
->next
, struct btrfs_root
,
2290 __update_reloc_root(reloc_root
, 1);
2291 free_extent_buffer(reloc_root
->node
);
2292 free_extent_buffer(reloc_root
->commit_root
);
2297 static noinline_for_stack
2298 int merge_reloc_roots(struct reloc_control
*rc
)
2300 struct btrfs_trans_handle
*trans
;
2301 struct btrfs_root
*root
;
2302 struct btrfs_root
*reloc_root
;
2306 LIST_HEAD(reloc_roots
);
2310 root
= rc
->extent_root
;
2313 * this serializes us with btrfs_record_root_in_transaction,
2314 * we have to make sure nobody is in the middle of
2315 * adding their roots to the list while we are
2318 mutex_lock(&root
->fs_info
->reloc_mutex
);
2319 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
2320 mutex_unlock(&root
->fs_info
->reloc_mutex
);
2322 while (!list_empty(&reloc_roots
)) {
2324 reloc_root
= list_entry(reloc_roots
.next
,
2325 struct btrfs_root
, root_list
);
2327 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
2328 root
= read_fs_root(reloc_root
->fs_info
,
2329 reloc_root
->root_key
.offset
);
2330 BUG_ON(IS_ERR(root
));
2331 BUG_ON(root
->reloc_root
!= reloc_root
);
2333 ret
= merge_reloc_root(rc
, root
);
2335 __update_reloc_root(reloc_root
, 1);
2336 free_extent_buffer(reloc_root
->node
);
2337 free_extent_buffer(reloc_root
->commit_root
);
2342 list_del_init(&reloc_root
->root_list
);
2346 * we keep the old last snapshod transid in rtranid when we
2347 * created the relocation tree.
2349 last_snap
= btrfs_root_rtransid(&reloc_root
->root_item
);
2350 otransid
= btrfs_root_otransid(&reloc_root
->root_item
);
2351 objectid
= reloc_root
->root_key
.offset
;
2353 ret
= btrfs_drop_snapshot(reloc_root
, rc
->block_rsv
, 0, 1);
2355 if (list_empty(&reloc_root
->root_list
))
2356 list_add_tail(&reloc_root
->root_list
,
2361 * recover the last snapshot tranid to avoid
2362 * the space balance break NOCOW.
2364 root
= read_fs_root(rc
->extent_root
->fs_info
,
2369 trans
= btrfs_join_transaction(root
);
2370 BUG_ON(IS_ERR(trans
));
2372 /* Check if the fs/file tree was snapshoted or not. */
2373 if (btrfs_root_last_snapshot(&root
->root_item
) ==
2375 btrfs_set_root_last_snapshot(&root
->root_item
,
2378 btrfs_end_transaction(trans
, root
);
2388 btrfs_std_error(root
->fs_info
, ret
);
2389 if (!list_empty(&reloc_roots
))
2390 free_reloc_roots(&reloc_roots
);
2393 BUG_ON(!RB_EMPTY_ROOT(&rc
->reloc_root_tree
.rb_root
));
2397 static void free_block_list(struct rb_root
*blocks
)
2399 struct tree_block
*block
;
2400 struct rb_node
*rb_node
;
2401 while ((rb_node
= rb_first(blocks
))) {
2402 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2403 rb_erase(rb_node
, blocks
);
2408 static int record_reloc_root_in_trans(struct btrfs_trans_handle
*trans
,
2409 struct btrfs_root
*reloc_root
)
2411 struct btrfs_root
*root
;
2413 if (reloc_root
->last_trans
== trans
->transid
)
2416 root
= read_fs_root(reloc_root
->fs_info
, reloc_root
->root_key
.offset
);
2417 BUG_ON(IS_ERR(root
));
2418 BUG_ON(root
->reloc_root
!= reloc_root
);
2420 return btrfs_record_root_in_trans(trans
, root
);
2423 static noinline_for_stack
2424 struct btrfs_root
*select_reloc_root(struct btrfs_trans_handle
*trans
,
2425 struct reloc_control
*rc
,
2426 struct backref_node
*node
,
2427 struct backref_edge
*edges
[], int *nr
)
2429 struct backref_node
*next
;
2430 struct btrfs_root
*root
;
2436 next
= walk_up_backref(next
, edges
, &index
);
2439 BUG_ON(!root
->ref_cows
);
2441 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
2442 record_reloc_root_in_trans(trans
, root
);
2446 btrfs_record_root_in_trans(trans
, root
);
2447 root
= root
->reloc_root
;
2449 if (next
->new_bytenr
!= root
->node
->start
) {
2450 BUG_ON(next
->new_bytenr
);
2451 BUG_ON(!list_empty(&next
->list
));
2452 next
->new_bytenr
= root
->node
->start
;
2454 list_add_tail(&next
->list
,
2455 &rc
->backref_cache
.changed
);
2456 __mark_block_processed(rc
, next
);
2462 next
= walk_down_backref(edges
, &index
);
2463 if (!next
|| next
->level
<= node
->level
)
2471 /* setup backref node path for btrfs_reloc_cow_block */
2473 rc
->backref_cache
.path
[next
->level
] = next
;
2476 next
= edges
[index
]->node
[UPPER
];
2482 * select a tree root for relocation. return NULL if the block
2483 * is reference counted. we should use do_relocation() in this
2484 * case. return a tree root pointer if the block isn't reference
2485 * counted. return -ENOENT if the block is root of reloc tree.
2487 static noinline_for_stack
2488 struct btrfs_root
*select_one_root(struct btrfs_trans_handle
*trans
,
2489 struct backref_node
*node
)
2491 struct backref_node
*next
;
2492 struct btrfs_root
*root
;
2493 struct btrfs_root
*fs_root
= NULL
;
2494 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2500 next
= walk_up_backref(next
, edges
, &index
);
2504 /* no other choice for non-references counted tree */
2505 if (!root
->ref_cows
)
2508 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
)
2514 next
= walk_down_backref(edges
, &index
);
2515 if (!next
|| next
->level
<= node
->level
)
2520 return ERR_PTR(-ENOENT
);
2524 static noinline_for_stack
2525 u64
calcu_metadata_size(struct reloc_control
*rc
,
2526 struct backref_node
*node
, int reserve
)
2528 struct backref_node
*next
= node
;
2529 struct backref_edge
*edge
;
2530 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2534 BUG_ON(reserve
&& node
->processed
);
2539 if (next
->processed
&& (reserve
|| next
!= node
))
2542 num_bytes
+= btrfs_level_size(rc
->extent_root
,
2545 if (list_empty(&next
->upper
))
2548 edge
= list_entry(next
->upper
.next
,
2549 struct backref_edge
, list
[LOWER
]);
2550 edges
[index
++] = edge
;
2551 next
= edge
->node
[UPPER
];
2553 next
= walk_down_backref(edges
, &index
);
2558 static int reserve_metadata_space(struct btrfs_trans_handle
*trans
,
2559 struct reloc_control
*rc
,
2560 struct backref_node
*node
)
2562 struct btrfs_root
*root
= rc
->extent_root
;
2566 num_bytes
= calcu_metadata_size(rc
, node
, 1) * 2;
2568 trans
->block_rsv
= rc
->block_rsv
;
2569 ret
= btrfs_block_rsv_add(root
, rc
->block_rsv
, num_bytes
,
2570 BTRFS_RESERVE_FLUSH_ALL
);
2573 rc
->commit_transaction
= 1;
2580 static void release_metadata_space(struct reloc_control
*rc
,
2581 struct backref_node
*node
)
2583 u64 num_bytes
= calcu_metadata_size(rc
, node
, 0) * 2;
2584 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, num_bytes
);
2588 * relocate a block tree, and then update pointers in upper level
2589 * blocks that reference the block to point to the new location.
2591 * if called by link_to_upper, the block has already been relocated.
2592 * in that case this function just updates pointers.
2594 static int do_relocation(struct btrfs_trans_handle
*trans
,
2595 struct reloc_control
*rc
,
2596 struct backref_node
*node
,
2597 struct btrfs_key
*key
,
2598 struct btrfs_path
*path
, int lowest
)
2600 struct backref_node
*upper
;
2601 struct backref_edge
*edge
;
2602 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2603 struct btrfs_root
*root
;
2604 struct extent_buffer
*eb
;
2613 BUG_ON(lowest
&& node
->eb
);
2615 path
->lowest_level
= node
->level
+ 1;
2616 rc
->backref_cache
.path
[node
->level
] = node
;
2617 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
]) {
2620 upper
= edge
->node
[UPPER
];
2621 root
= select_reloc_root(trans
, rc
, upper
, edges
, &nr
);
2624 if (upper
->eb
&& !upper
->locked
) {
2626 ret
= btrfs_bin_search(upper
->eb
, key
,
2627 upper
->level
, &slot
);
2629 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2630 if (node
->eb
->start
== bytenr
)
2633 drop_node_buffer(upper
);
2637 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2645 upper
->eb
= path
->nodes
[upper
->level
];
2646 path
->nodes
[upper
->level
] = NULL
;
2648 BUG_ON(upper
->eb
!= path
->nodes
[upper
->level
]);
2652 path
->locks
[upper
->level
] = 0;
2654 slot
= path
->slots
[upper
->level
];
2655 btrfs_release_path(path
);
2657 ret
= btrfs_bin_search(upper
->eb
, key
, upper
->level
,
2662 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2664 BUG_ON(bytenr
!= node
->bytenr
);
2666 if (node
->eb
->start
== bytenr
)
2670 blocksize
= btrfs_level_size(root
, node
->level
);
2671 generation
= btrfs_node_ptr_generation(upper
->eb
, slot
);
2672 eb
= read_tree_block(root
, bytenr
, blocksize
, generation
);
2673 if (!eb
|| !extent_buffer_uptodate(eb
)) {
2674 free_extent_buffer(eb
);
2678 btrfs_tree_lock(eb
);
2679 btrfs_set_lock_blocking(eb
);
2682 ret
= btrfs_cow_block(trans
, root
, eb
, upper
->eb
,
2684 btrfs_tree_unlock(eb
);
2685 free_extent_buffer(eb
);
2690 BUG_ON(node
->eb
!= eb
);
2692 btrfs_set_node_blockptr(upper
->eb
, slot
,
2694 btrfs_set_node_ptr_generation(upper
->eb
, slot
,
2696 btrfs_mark_buffer_dirty(upper
->eb
);
2698 ret
= btrfs_inc_extent_ref(trans
, root
,
2699 node
->eb
->start
, blocksize
,
2701 btrfs_header_owner(upper
->eb
),
2705 ret
= btrfs_drop_subtree(trans
, root
, eb
, upper
->eb
);
2709 if (!upper
->pending
)
2710 drop_node_buffer(upper
);
2712 unlock_node_buffer(upper
);
2717 if (!err
&& node
->pending
) {
2718 drop_node_buffer(node
);
2719 list_move_tail(&node
->list
, &rc
->backref_cache
.changed
);
2723 path
->lowest_level
= 0;
2724 BUG_ON(err
== -ENOSPC
);
2728 static int link_to_upper(struct btrfs_trans_handle
*trans
,
2729 struct reloc_control
*rc
,
2730 struct backref_node
*node
,
2731 struct btrfs_path
*path
)
2733 struct btrfs_key key
;
2735 btrfs_node_key_to_cpu(node
->eb
, &key
, 0);
2736 return do_relocation(trans
, rc
, node
, &key
, path
, 0);
2739 static int finish_pending_nodes(struct btrfs_trans_handle
*trans
,
2740 struct reloc_control
*rc
,
2741 struct btrfs_path
*path
, int err
)
2744 struct backref_cache
*cache
= &rc
->backref_cache
;
2745 struct backref_node
*node
;
2749 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
2750 while (!list_empty(&cache
->pending
[level
])) {
2751 node
= list_entry(cache
->pending
[level
].next
,
2752 struct backref_node
, list
);
2753 list_move_tail(&node
->list
, &list
);
2754 BUG_ON(!node
->pending
);
2757 ret
= link_to_upper(trans
, rc
, node
, path
);
2762 list_splice_init(&list
, &cache
->pending
[level
]);
2767 static void mark_block_processed(struct reloc_control
*rc
,
2768 u64 bytenr
, u32 blocksize
)
2770 set_extent_bits(&rc
->processed_blocks
, bytenr
, bytenr
+ blocksize
- 1,
2771 EXTENT_DIRTY
, GFP_NOFS
);
2774 static void __mark_block_processed(struct reloc_control
*rc
,
2775 struct backref_node
*node
)
2778 if (node
->level
== 0 ||
2779 in_block_group(node
->bytenr
, rc
->block_group
)) {
2780 blocksize
= btrfs_level_size(rc
->extent_root
, node
->level
);
2781 mark_block_processed(rc
, node
->bytenr
, blocksize
);
2783 node
->processed
= 1;
2787 * mark a block and all blocks directly/indirectly reference the block
2790 static void update_processed_blocks(struct reloc_control
*rc
,
2791 struct backref_node
*node
)
2793 struct backref_node
*next
= node
;
2794 struct backref_edge
*edge
;
2795 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2801 if (next
->processed
)
2804 __mark_block_processed(rc
, next
);
2806 if (list_empty(&next
->upper
))
2809 edge
= list_entry(next
->upper
.next
,
2810 struct backref_edge
, list
[LOWER
]);
2811 edges
[index
++] = edge
;
2812 next
= edge
->node
[UPPER
];
2814 next
= walk_down_backref(edges
, &index
);
2818 static int tree_block_processed(u64 bytenr
, u32 blocksize
,
2819 struct reloc_control
*rc
)
2821 if (test_range_bit(&rc
->processed_blocks
, bytenr
,
2822 bytenr
+ blocksize
- 1, EXTENT_DIRTY
, 1, NULL
))
2827 static int get_tree_block_key(struct reloc_control
*rc
,
2828 struct tree_block
*block
)
2830 struct extent_buffer
*eb
;
2832 BUG_ON(block
->key_ready
);
2833 eb
= read_tree_block(rc
->extent_root
, block
->bytenr
,
2834 block
->key
.objectid
, block
->key
.offset
);
2835 if (!eb
|| !extent_buffer_uptodate(eb
)) {
2836 free_extent_buffer(eb
);
2839 WARN_ON(btrfs_header_level(eb
) != block
->level
);
2840 if (block
->level
== 0)
2841 btrfs_item_key_to_cpu(eb
, &block
->key
, 0);
2843 btrfs_node_key_to_cpu(eb
, &block
->key
, 0);
2844 free_extent_buffer(eb
);
2845 block
->key_ready
= 1;
2849 static int reada_tree_block(struct reloc_control
*rc
,
2850 struct tree_block
*block
)
2852 BUG_ON(block
->key_ready
);
2853 if (block
->key
.type
== BTRFS_METADATA_ITEM_KEY
)
2854 readahead_tree_block(rc
->extent_root
, block
->bytenr
,
2855 block
->key
.objectid
,
2856 rc
->extent_root
->leafsize
);
2858 readahead_tree_block(rc
->extent_root
, block
->bytenr
,
2859 block
->key
.objectid
, block
->key
.offset
);
2864 * helper function to relocate a tree block
2866 static int relocate_tree_block(struct btrfs_trans_handle
*trans
,
2867 struct reloc_control
*rc
,
2868 struct backref_node
*node
,
2869 struct btrfs_key
*key
,
2870 struct btrfs_path
*path
)
2872 struct btrfs_root
*root
;
2879 BUG_ON(node
->processed
);
2880 root
= select_one_root(trans
, node
);
2881 if (root
== ERR_PTR(-ENOENT
)) {
2882 update_processed_blocks(rc
, node
);
2886 if (!root
|| root
->ref_cows
) {
2887 ret
= reserve_metadata_space(trans
, rc
, node
);
2894 if (root
->ref_cows
) {
2895 BUG_ON(node
->new_bytenr
);
2896 BUG_ON(!list_empty(&node
->list
));
2897 btrfs_record_root_in_trans(trans
, root
);
2898 root
= root
->reloc_root
;
2899 node
->new_bytenr
= root
->node
->start
;
2901 list_add_tail(&node
->list
, &rc
->backref_cache
.changed
);
2903 path
->lowest_level
= node
->level
;
2904 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2905 btrfs_release_path(path
);
2910 update_processed_blocks(rc
, node
);
2912 ret
= do_relocation(trans
, rc
, node
, key
, path
, 1);
2915 if (ret
|| node
->level
== 0 || node
->cowonly
) {
2917 release_metadata_space(rc
, node
);
2918 remove_backref_node(&rc
->backref_cache
, node
);
2924 * relocate a list of blocks
2926 static noinline_for_stack
2927 int relocate_tree_blocks(struct btrfs_trans_handle
*trans
,
2928 struct reloc_control
*rc
, struct rb_root
*blocks
)
2930 struct backref_node
*node
;
2931 struct btrfs_path
*path
;
2932 struct tree_block
*block
;
2933 struct rb_node
*rb_node
;
2937 path
= btrfs_alloc_path();
2940 goto out_free_blocks
;
2943 rb_node
= rb_first(blocks
);
2945 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2946 if (!block
->key_ready
)
2947 reada_tree_block(rc
, block
);
2948 rb_node
= rb_next(rb_node
);
2951 rb_node
= rb_first(blocks
);
2953 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2954 if (!block
->key_ready
) {
2955 err
= get_tree_block_key(rc
, block
);
2959 rb_node
= rb_next(rb_node
);
2962 rb_node
= rb_first(blocks
);
2964 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2966 node
= build_backref_tree(rc
, &block
->key
,
2967 block
->level
, block
->bytenr
);
2969 err
= PTR_ERR(node
);
2973 ret
= relocate_tree_block(trans
, rc
, node
, &block
->key
,
2976 if (ret
!= -EAGAIN
|| rb_node
== rb_first(blocks
))
2980 rb_node
= rb_next(rb_node
);
2983 err
= finish_pending_nodes(trans
, rc
, path
, err
);
2986 btrfs_free_path(path
);
2988 free_block_list(blocks
);
2992 static noinline_for_stack
2993 int prealloc_file_extent_cluster(struct inode
*inode
,
2994 struct file_extent_cluster
*cluster
)
2999 u64 offset
= BTRFS_I(inode
)->index_cnt
;
3004 BUG_ON(cluster
->start
!= cluster
->boundary
[0]);
3005 mutex_lock(&inode
->i_mutex
);
3007 ret
= btrfs_check_data_free_space(inode
, cluster
->end
+
3008 1 - cluster
->start
);
3012 while (nr
< cluster
->nr
) {
3013 start
= cluster
->boundary
[nr
] - offset
;
3014 if (nr
+ 1 < cluster
->nr
)
3015 end
= cluster
->boundary
[nr
+ 1] - 1 - offset
;
3017 end
= cluster
->end
- offset
;
3019 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3020 num_bytes
= end
+ 1 - start
;
3021 ret
= btrfs_prealloc_file_range(inode
, 0, start
,
3022 num_bytes
, num_bytes
,
3023 end
+ 1, &alloc_hint
);
3024 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3029 btrfs_free_reserved_data_space(inode
, cluster
->end
+
3030 1 - cluster
->start
);
3032 mutex_unlock(&inode
->i_mutex
);
3036 static noinline_for_stack
3037 int setup_extent_mapping(struct inode
*inode
, u64 start
, u64 end
,
3040 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
3041 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
3042 struct extent_map
*em
;
3045 em
= alloc_extent_map();
3050 em
->len
= end
+ 1 - start
;
3051 em
->block_len
= em
->len
;
3052 em
->block_start
= block_start
;
3053 em
->bdev
= root
->fs_info
->fs_devices
->latest_bdev
;
3054 set_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
3056 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3058 write_lock(&em_tree
->lock
);
3059 ret
= add_extent_mapping(em_tree
, em
, 0);
3060 write_unlock(&em_tree
->lock
);
3061 if (ret
!= -EEXIST
) {
3062 free_extent_map(em
);
3065 btrfs_drop_extent_cache(inode
, start
, end
, 0);
3067 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3071 static int relocate_file_extent_cluster(struct inode
*inode
,
3072 struct file_extent_cluster
*cluster
)
3076 u64 offset
= BTRFS_I(inode
)->index_cnt
;
3077 unsigned long index
;
3078 unsigned long last_index
;
3080 struct file_ra_state
*ra
;
3081 gfp_t mask
= btrfs_alloc_write_mask(inode
->i_mapping
);
3088 ra
= kzalloc(sizeof(*ra
), GFP_NOFS
);
3092 ret
= prealloc_file_extent_cluster(inode
, cluster
);
3096 file_ra_state_init(ra
, inode
->i_mapping
);
3098 ret
= setup_extent_mapping(inode
, cluster
->start
- offset
,
3099 cluster
->end
- offset
, cluster
->start
);
3103 index
= (cluster
->start
- offset
) >> PAGE_CACHE_SHIFT
;
3104 last_index
= (cluster
->end
- offset
) >> PAGE_CACHE_SHIFT
;
3105 while (index
<= last_index
) {
3106 ret
= btrfs_delalloc_reserve_metadata(inode
, PAGE_CACHE_SIZE
);
3110 page
= find_lock_page(inode
->i_mapping
, index
);
3112 page_cache_sync_readahead(inode
->i_mapping
,
3114 last_index
+ 1 - index
);
3115 page
= find_or_create_page(inode
->i_mapping
, index
,
3118 btrfs_delalloc_release_metadata(inode
,
3125 if (PageReadahead(page
)) {
3126 page_cache_async_readahead(inode
->i_mapping
,
3127 ra
, NULL
, page
, index
,
3128 last_index
+ 1 - index
);
3131 if (!PageUptodate(page
)) {
3132 btrfs_readpage(NULL
, page
);
3134 if (!PageUptodate(page
)) {
3136 page_cache_release(page
);
3137 btrfs_delalloc_release_metadata(inode
,
3144 page_start
= page_offset(page
);
3145 page_end
= page_start
+ PAGE_CACHE_SIZE
- 1;
3147 lock_extent(&BTRFS_I(inode
)->io_tree
, page_start
, page_end
);
3149 set_page_extent_mapped(page
);
3151 if (nr
< cluster
->nr
&&
3152 page_start
+ offset
== cluster
->boundary
[nr
]) {
3153 set_extent_bits(&BTRFS_I(inode
)->io_tree
,
3154 page_start
, page_end
,
3155 EXTENT_BOUNDARY
, GFP_NOFS
);
3159 btrfs_set_extent_delalloc(inode
, page_start
, page_end
, NULL
);
3160 set_page_dirty(page
);
3162 unlock_extent(&BTRFS_I(inode
)->io_tree
,
3163 page_start
, page_end
);
3165 page_cache_release(page
);
3168 balance_dirty_pages_ratelimited(inode
->i_mapping
);
3169 btrfs_throttle(BTRFS_I(inode
)->root
);
3171 WARN_ON(nr
!= cluster
->nr
);
3177 static noinline_for_stack
3178 int relocate_data_extent(struct inode
*inode
, struct btrfs_key
*extent_key
,
3179 struct file_extent_cluster
*cluster
)
3183 if (cluster
->nr
> 0 && extent_key
->objectid
!= cluster
->end
+ 1) {
3184 ret
= relocate_file_extent_cluster(inode
, cluster
);
3191 cluster
->start
= extent_key
->objectid
;
3193 BUG_ON(cluster
->nr
>= MAX_EXTENTS
);
3194 cluster
->end
= extent_key
->objectid
+ extent_key
->offset
- 1;
3195 cluster
->boundary
[cluster
->nr
] = extent_key
->objectid
;
3198 if (cluster
->nr
>= MAX_EXTENTS
) {
3199 ret
= relocate_file_extent_cluster(inode
, cluster
);
3207 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3208 static int get_ref_objectid_v0(struct reloc_control
*rc
,
3209 struct btrfs_path
*path
,
3210 struct btrfs_key
*extent_key
,
3211 u64
*ref_objectid
, int *path_change
)
3213 struct btrfs_key key
;
3214 struct extent_buffer
*leaf
;
3215 struct btrfs_extent_ref_v0
*ref0
;
3219 leaf
= path
->nodes
[0];
3220 slot
= path
->slots
[0];
3222 if (slot
>= btrfs_header_nritems(leaf
)) {
3223 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3227 leaf
= path
->nodes
[0];
3228 slot
= path
->slots
[0];
3232 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
3233 if (key
.objectid
!= extent_key
->objectid
)
3236 if (key
.type
!= BTRFS_EXTENT_REF_V0_KEY
) {
3240 ref0
= btrfs_item_ptr(leaf
, slot
,
3241 struct btrfs_extent_ref_v0
);
3242 *ref_objectid
= btrfs_ref_objectid_v0(leaf
, ref0
);
3250 * helper to add a tree block to the list.
3251 * the major work is getting the generation and level of the block
3253 static int add_tree_block(struct reloc_control
*rc
,
3254 struct btrfs_key
*extent_key
,
3255 struct btrfs_path
*path
,
3256 struct rb_root
*blocks
)
3258 struct extent_buffer
*eb
;
3259 struct btrfs_extent_item
*ei
;
3260 struct btrfs_tree_block_info
*bi
;
3261 struct tree_block
*block
;
3262 struct rb_node
*rb_node
;
3267 eb
= path
->nodes
[0];
3268 item_size
= btrfs_item_size_nr(eb
, path
->slots
[0]);
3270 if (extent_key
->type
== BTRFS_METADATA_ITEM_KEY
||
3271 item_size
>= sizeof(*ei
) + sizeof(*bi
)) {
3272 ei
= btrfs_item_ptr(eb
, path
->slots
[0],
3273 struct btrfs_extent_item
);
3274 if (extent_key
->type
== BTRFS_EXTENT_ITEM_KEY
) {
3275 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
3276 level
= btrfs_tree_block_level(eb
, bi
);
3278 level
= (int)extent_key
->offset
;
3280 generation
= btrfs_extent_generation(eb
, ei
);
3282 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3286 BUG_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
3287 ret
= get_ref_objectid_v0(rc
, path
, extent_key
,
3291 BUG_ON(ref_owner
>= BTRFS_MAX_LEVEL
);
3292 level
= (int)ref_owner
;
3293 /* FIXME: get real generation */
3300 btrfs_release_path(path
);
3302 BUG_ON(level
== -1);
3304 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3308 block
->bytenr
= extent_key
->objectid
;
3309 block
->key
.objectid
= rc
->extent_root
->leafsize
;
3310 block
->key
.offset
= generation
;
3311 block
->level
= level
;
3312 block
->key_ready
= 0;
3314 rb_node
= tree_insert(blocks
, block
->bytenr
, &block
->rb_node
);
3316 backref_tree_panic(rb_node
, -EEXIST
, block
->bytenr
);
3322 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3324 static int __add_tree_block(struct reloc_control
*rc
,
3325 u64 bytenr
, u32 blocksize
,
3326 struct rb_root
*blocks
)
3328 struct btrfs_path
*path
;
3329 struct btrfs_key key
;
3331 bool skinny
= btrfs_fs_incompat(rc
->extent_root
->fs_info
,
3334 if (tree_block_processed(bytenr
, blocksize
, rc
))
3337 if (tree_search(blocks
, bytenr
))
3340 path
= btrfs_alloc_path();
3344 key
.objectid
= bytenr
;
3346 key
.type
= BTRFS_METADATA_ITEM_KEY
;
3347 key
.offset
= (u64
)-1;
3349 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3350 key
.offset
= blocksize
;
3353 path
->search_commit_root
= 1;
3354 path
->skip_locking
= 1;
3355 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
, 0, 0);
3359 if (ret
> 0 && skinny
) {
3360 if (path
->slots
[0]) {
3362 btrfs_item_key_to_cpu(path
->nodes
[0], &key
,
3364 if (key
.objectid
== bytenr
&&
3365 (key
.type
== BTRFS_METADATA_ITEM_KEY
||
3366 (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
3367 key
.offset
== blocksize
)))
3373 btrfs_release_path(path
);
3379 ret
= add_tree_block(rc
, &key
, path
, blocks
);
3381 btrfs_free_path(path
);
3386 * helper to check if the block use full backrefs for pointers in it
3388 static int block_use_full_backref(struct reloc_control
*rc
,
3389 struct extent_buffer
*eb
)
3394 if (btrfs_header_flag(eb
, BTRFS_HEADER_FLAG_RELOC
) ||
3395 btrfs_header_backref_rev(eb
) < BTRFS_MIXED_BACKREF_REV
)
3398 ret
= btrfs_lookup_extent_info(NULL
, rc
->extent_root
,
3399 eb
->start
, btrfs_header_level(eb
), 1,
3403 if (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
)
3410 static int delete_block_group_cache(struct btrfs_fs_info
*fs_info
,
3411 struct inode
*inode
, u64 ino
)
3413 struct btrfs_key key
;
3414 struct btrfs_root
*root
= fs_info
->tree_root
;
3415 struct btrfs_trans_handle
*trans
;
3422 key
.type
= BTRFS_INODE_ITEM_KEY
;
3425 inode
= btrfs_iget(fs_info
->sb
, &key
, root
, NULL
);
3426 if (IS_ERR(inode
) || is_bad_inode(inode
)) {
3433 ret
= btrfs_check_trunc_cache_free_space(root
,
3434 &fs_info
->global_block_rsv
);
3438 trans
= btrfs_join_transaction(root
);
3439 if (IS_ERR(trans
)) {
3440 ret
= PTR_ERR(trans
);
3444 ret
= btrfs_truncate_free_space_cache(root
, trans
, inode
);
3446 btrfs_end_transaction(trans
, root
);
3447 btrfs_btree_balance_dirty(root
);
3454 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3455 * this function scans fs tree to find blocks reference the data extent
3457 static int find_data_references(struct reloc_control
*rc
,
3458 struct btrfs_key
*extent_key
,
3459 struct extent_buffer
*leaf
,
3460 struct btrfs_extent_data_ref
*ref
,
3461 struct rb_root
*blocks
)
3463 struct btrfs_path
*path
;
3464 struct tree_block
*block
;
3465 struct btrfs_root
*root
;
3466 struct btrfs_file_extent_item
*fi
;
3467 struct rb_node
*rb_node
;
3468 struct btrfs_key key
;
3479 ref_root
= btrfs_extent_data_ref_root(leaf
, ref
);
3480 ref_objectid
= btrfs_extent_data_ref_objectid(leaf
, ref
);
3481 ref_offset
= btrfs_extent_data_ref_offset(leaf
, ref
);
3482 ref_count
= btrfs_extent_data_ref_count(leaf
, ref
);
3485 * This is an extent belonging to the free space cache, lets just delete
3486 * it and redo the search.
3488 if (ref_root
== BTRFS_ROOT_TREE_OBJECTID
) {
3489 ret
= delete_block_group_cache(rc
->extent_root
->fs_info
,
3490 NULL
, ref_objectid
);
3496 path
= btrfs_alloc_path();
3501 root
= read_fs_root(rc
->extent_root
->fs_info
, ref_root
);
3503 err
= PTR_ERR(root
);
3507 key
.objectid
= ref_objectid
;
3508 key
.type
= BTRFS_EXTENT_DATA_KEY
;
3509 if (ref_offset
> ((u64
)-1 << 32))
3512 key
.offset
= ref_offset
;
3514 path
->search_commit_root
= 1;
3515 path
->skip_locking
= 1;
3516 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
3522 leaf
= path
->nodes
[0];
3523 nritems
= btrfs_header_nritems(leaf
);
3525 * the references in tree blocks that use full backrefs
3526 * are not counted in
3528 if (block_use_full_backref(rc
, leaf
))
3532 rb_node
= tree_search(blocks
, leaf
->start
);
3537 path
->slots
[0] = nritems
;
3540 while (ref_count
> 0) {
3541 while (path
->slots
[0] >= nritems
) {
3542 ret
= btrfs_next_leaf(root
, path
);
3547 if (WARN_ON(ret
> 0))
3550 leaf
= path
->nodes
[0];
3551 nritems
= btrfs_header_nritems(leaf
);
3554 if (block_use_full_backref(rc
, leaf
))
3558 rb_node
= tree_search(blocks
, leaf
->start
);
3563 path
->slots
[0] = nritems
;
3567 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3568 if (WARN_ON(key
.objectid
!= ref_objectid
||
3569 key
.type
!= BTRFS_EXTENT_DATA_KEY
))
3572 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3573 struct btrfs_file_extent_item
);
3575 if (btrfs_file_extent_type(leaf
, fi
) ==
3576 BTRFS_FILE_EXTENT_INLINE
)
3579 if (btrfs_file_extent_disk_bytenr(leaf
, fi
) !=
3580 extent_key
->objectid
)
3583 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
3584 if (key
.offset
!= ref_offset
)
3592 if (!tree_block_processed(leaf
->start
, leaf
->len
, rc
)) {
3593 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3598 block
->bytenr
= leaf
->start
;
3599 btrfs_item_key_to_cpu(leaf
, &block
->key
, 0);
3601 block
->key_ready
= 1;
3602 rb_node
= tree_insert(blocks
, block
->bytenr
,
3605 backref_tree_panic(rb_node
, -EEXIST
,
3611 path
->slots
[0] = nritems
;
3617 btrfs_free_path(path
);
3622 * helper to find all tree blocks that reference a given data extent
3624 static noinline_for_stack
3625 int add_data_references(struct reloc_control
*rc
,
3626 struct btrfs_key
*extent_key
,
3627 struct btrfs_path
*path
,
3628 struct rb_root
*blocks
)
3630 struct btrfs_key key
;
3631 struct extent_buffer
*eb
;
3632 struct btrfs_extent_data_ref
*dref
;
3633 struct btrfs_extent_inline_ref
*iref
;
3636 u32 blocksize
= btrfs_level_size(rc
->extent_root
, 0);
3640 eb
= path
->nodes
[0];
3641 ptr
= btrfs_item_ptr_offset(eb
, path
->slots
[0]);
3642 end
= ptr
+ btrfs_item_size_nr(eb
, path
->slots
[0]);
3643 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3644 if (ptr
+ sizeof(struct btrfs_extent_item_v0
) == end
)
3648 ptr
+= sizeof(struct btrfs_extent_item
);
3651 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
3652 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
3653 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3654 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
3655 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3657 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3658 dref
= (struct btrfs_extent_data_ref
*)(&iref
->offset
);
3659 ret
= find_data_references(rc
, extent_key
,
3668 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
3674 eb
= path
->nodes
[0];
3675 if (path
->slots
[0] >= btrfs_header_nritems(eb
)) {
3676 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3683 eb
= path
->nodes
[0];
3686 btrfs_item_key_to_cpu(eb
, &key
, path
->slots
[0]);
3687 if (key
.objectid
!= extent_key
->objectid
)
3690 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3691 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
||
3692 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
3694 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
3695 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3697 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3699 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3700 dref
= btrfs_item_ptr(eb
, path
->slots
[0],
3701 struct btrfs_extent_data_ref
);
3702 ret
= find_data_references(rc
, extent_key
,
3714 btrfs_release_path(path
);
3716 free_block_list(blocks
);
3721 * helper to find next unprocessed extent
3723 static noinline_for_stack
3724 int find_next_extent(struct btrfs_trans_handle
*trans
,
3725 struct reloc_control
*rc
, struct btrfs_path
*path
,
3726 struct btrfs_key
*extent_key
)
3728 struct btrfs_key key
;
3729 struct extent_buffer
*leaf
;
3730 u64 start
, end
, last
;
3733 last
= rc
->block_group
->key
.objectid
+ rc
->block_group
->key
.offset
;
3736 if (rc
->search_start
>= last
) {
3741 key
.objectid
= rc
->search_start
;
3742 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3745 path
->search_commit_root
= 1;
3746 path
->skip_locking
= 1;
3747 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
,
3752 leaf
= path
->nodes
[0];
3753 if (path
->slots
[0] >= btrfs_header_nritems(leaf
)) {
3754 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3757 leaf
= path
->nodes
[0];
3760 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3761 if (key
.objectid
>= last
) {
3766 if (key
.type
!= BTRFS_EXTENT_ITEM_KEY
&&
3767 key
.type
!= BTRFS_METADATA_ITEM_KEY
) {
3772 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
3773 key
.objectid
+ key
.offset
<= rc
->search_start
) {
3778 if (key
.type
== BTRFS_METADATA_ITEM_KEY
&&
3779 key
.objectid
+ rc
->extent_root
->leafsize
<=
3785 ret
= find_first_extent_bit(&rc
->processed_blocks
,
3786 key
.objectid
, &start
, &end
,
3787 EXTENT_DIRTY
, NULL
);
3789 if (ret
== 0 && start
<= key
.objectid
) {
3790 btrfs_release_path(path
);
3791 rc
->search_start
= end
+ 1;
3793 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
)
3794 rc
->search_start
= key
.objectid
+ key
.offset
;
3796 rc
->search_start
= key
.objectid
+
3797 rc
->extent_root
->leafsize
;
3798 memcpy(extent_key
, &key
, sizeof(key
));
3802 btrfs_release_path(path
);
3806 static void set_reloc_control(struct reloc_control
*rc
)
3808 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3810 mutex_lock(&fs_info
->reloc_mutex
);
3811 fs_info
->reloc_ctl
= rc
;
3812 mutex_unlock(&fs_info
->reloc_mutex
);
3815 static void unset_reloc_control(struct reloc_control
*rc
)
3817 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3819 mutex_lock(&fs_info
->reloc_mutex
);
3820 fs_info
->reloc_ctl
= NULL
;
3821 mutex_unlock(&fs_info
->reloc_mutex
);
3824 static int check_extent_flags(u64 flags
)
3826 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3827 (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3829 if (!(flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3830 !(flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3832 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3833 (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
))
3838 static noinline_for_stack
3839 int prepare_to_relocate(struct reloc_control
*rc
)
3841 struct btrfs_trans_handle
*trans
;
3844 rc
->block_rsv
= btrfs_alloc_block_rsv(rc
->extent_root
,
3845 BTRFS_BLOCK_RSV_TEMP
);
3850 * reserve some space for creating reloc trees.
3851 * btrfs_init_reloc_root will use them when there
3852 * is no reservation in transaction handle.
3854 ret
= btrfs_block_rsv_add(rc
->extent_root
, rc
->block_rsv
,
3855 rc
->extent_root
->nodesize
* 256,
3856 BTRFS_RESERVE_FLUSH_ALL
);
3860 memset(&rc
->cluster
, 0, sizeof(rc
->cluster
));
3861 rc
->search_start
= rc
->block_group
->key
.objectid
;
3862 rc
->extents_found
= 0;
3863 rc
->nodes_relocated
= 0;
3864 rc
->merging_rsv_size
= 0;
3866 rc
->create_reloc_tree
= 1;
3867 set_reloc_control(rc
);
3869 trans
= btrfs_join_transaction(rc
->extent_root
);
3870 if (IS_ERR(trans
)) {
3871 unset_reloc_control(rc
);
3873 * extent tree is not a ref_cow tree and has no reloc_root to
3874 * cleanup. And callers are responsible to free the above
3877 return PTR_ERR(trans
);
3879 btrfs_commit_transaction(trans
, rc
->extent_root
);
3883 static noinline_for_stack
int relocate_block_group(struct reloc_control
*rc
)
3885 struct rb_root blocks
= RB_ROOT
;
3886 struct btrfs_key key
;
3887 struct btrfs_trans_handle
*trans
= NULL
;
3888 struct btrfs_path
*path
;
3889 struct btrfs_extent_item
*ei
;
3896 path
= btrfs_alloc_path();
3901 ret
= prepare_to_relocate(rc
);
3909 trans
= btrfs_start_transaction(rc
->extent_root
, 0);
3910 if (IS_ERR(trans
)) {
3911 err
= PTR_ERR(trans
);
3916 if (update_backref_cache(trans
, &rc
->backref_cache
)) {
3917 btrfs_end_transaction(trans
, rc
->extent_root
);
3921 ret
= find_next_extent(trans
, rc
, path
, &key
);
3927 rc
->extents_found
++;
3929 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
3930 struct btrfs_extent_item
);
3931 item_size
= btrfs_item_size_nr(path
->nodes
[0], path
->slots
[0]);
3932 if (item_size
>= sizeof(*ei
)) {
3933 flags
= btrfs_extent_flags(path
->nodes
[0], ei
);
3934 ret
= check_extent_flags(flags
);
3938 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3940 int path_change
= 0;
3943 sizeof(struct btrfs_extent_item_v0
));
3944 ret
= get_ref_objectid_v0(rc
, path
, &key
, &ref_owner
,
3946 if (ref_owner
< BTRFS_FIRST_FREE_OBJECTID
)
3947 flags
= BTRFS_EXTENT_FLAG_TREE_BLOCK
;
3949 flags
= BTRFS_EXTENT_FLAG_DATA
;
3952 btrfs_release_path(path
);
3954 path
->search_commit_root
= 1;
3955 path
->skip_locking
= 1;
3956 ret
= btrfs_search_slot(NULL
, rc
->extent_root
,
3969 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
3970 ret
= add_tree_block(rc
, &key
, path
, &blocks
);
3971 } else if (rc
->stage
== UPDATE_DATA_PTRS
&&
3972 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
3973 ret
= add_data_references(rc
, &key
, path
, &blocks
);
3975 btrfs_release_path(path
);
3983 if (!RB_EMPTY_ROOT(&blocks
)) {
3984 ret
= relocate_tree_blocks(trans
, rc
, &blocks
);
3986 if (ret
!= -EAGAIN
) {
3990 rc
->extents_found
--;
3991 rc
->search_start
= key
.objectid
;
3995 if (rc
->commit_transaction
) {
3996 rc
->commit_transaction
= 0;
3997 ret
= btrfs_commit_transaction(trans
, rc
->extent_root
);
4000 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
4001 btrfs_btree_balance_dirty(rc
->extent_root
);
4005 if (rc
->stage
== MOVE_DATA_EXTENTS
&&
4006 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
4007 rc
->found_file_extent
= 1;
4008 ret
= relocate_data_extent(rc
->data_inode
,
4009 &key
, &rc
->cluster
);
4016 if (trans
&& progress
&& err
== -ENOSPC
) {
4017 ret
= btrfs_force_chunk_alloc(trans
, rc
->extent_root
,
4018 rc
->block_group
->flags
);
4026 btrfs_release_path(path
);
4027 clear_extent_bits(&rc
->processed_blocks
, 0, (u64
)-1, EXTENT_DIRTY
,
4031 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
4032 btrfs_btree_balance_dirty(rc
->extent_root
);
4036 ret
= relocate_file_extent_cluster(rc
->data_inode
,
4042 rc
->create_reloc_tree
= 0;
4043 set_reloc_control(rc
);
4045 backref_cache_cleanup(&rc
->backref_cache
);
4046 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
4048 err
= prepare_to_merge(rc
, err
);
4050 merge_reloc_roots(rc
);
4052 rc
->merge_reloc_tree
= 0;
4053 unset_reloc_control(rc
);
4054 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
4056 /* get rid of pinned extents */
4057 trans
= btrfs_join_transaction(rc
->extent_root
);
4059 err
= PTR_ERR(trans
);
4061 btrfs_commit_transaction(trans
, rc
->extent_root
);
4063 btrfs_free_block_rsv(rc
->extent_root
, rc
->block_rsv
);
4064 btrfs_free_path(path
);
4068 static int __insert_orphan_inode(struct btrfs_trans_handle
*trans
,
4069 struct btrfs_root
*root
, u64 objectid
)
4071 struct btrfs_path
*path
;
4072 struct btrfs_inode_item
*item
;
4073 struct extent_buffer
*leaf
;
4076 path
= btrfs_alloc_path();
4080 ret
= btrfs_insert_empty_inode(trans
, root
, path
, objectid
);
4084 leaf
= path
->nodes
[0];
4085 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_inode_item
);
4086 memset_extent_buffer(leaf
, 0, (unsigned long)item
, sizeof(*item
));
4087 btrfs_set_inode_generation(leaf
, item
, 1);
4088 btrfs_set_inode_size(leaf
, item
, 0);
4089 btrfs_set_inode_mode(leaf
, item
, S_IFREG
| 0600);
4090 btrfs_set_inode_flags(leaf
, item
, BTRFS_INODE_NOCOMPRESS
|
4091 BTRFS_INODE_PREALLOC
);
4092 btrfs_mark_buffer_dirty(leaf
);
4093 btrfs_release_path(path
);
4095 btrfs_free_path(path
);
4100 * helper to create inode for data relocation.
4101 * the inode is in data relocation tree and its link count is 0
4103 static noinline_for_stack
4104 struct inode
*create_reloc_inode(struct btrfs_fs_info
*fs_info
,
4105 struct btrfs_block_group_cache
*group
)
4107 struct inode
*inode
= NULL
;
4108 struct btrfs_trans_handle
*trans
;
4109 struct btrfs_root
*root
;
4110 struct btrfs_key key
;
4111 u64 objectid
= BTRFS_FIRST_FREE_OBJECTID
;
4114 root
= read_fs_root(fs_info
, BTRFS_DATA_RELOC_TREE_OBJECTID
);
4116 return ERR_CAST(root
);
4118 trans
= btrfs_start_transaction(root
, 6);
4120 return ERR_CAST(trans
);
4122 err
= btrfs_find_free_objectid(root
, &objectid
);
4126 err
= __insert_orphan_inode(trans
, root
, objectid
);
4129 key
.objectid
= objectid
;
4130 key
.type
= BTRFS_INODE_ITEM_KEY
;
4132 inode
= btrfs_iget(root
->fs_info
->sb
, &key
, root
, NULL
);
4133 BUG_ON(IS_ERR(inode
) || is_bad_inode(inode
));
4134 BTRFS_I(inode
)->index_cnt
= group
->key
.objectid
;
4136 err
= btrfs_orphan_add(trans
, inode
);
4138 btrfs_end_transaction(trans
, root
);
4139 btrfs_btree_balance_dirty(root
);
4143 inode
= ERR_PTR(err
);
4148 static struct reloc_control
*alloc_reloc_control(struct btrfs_fs_info
*fs_info
)
4150 struct reloc_control
*rc
;
4152 rc
= kzalloc(sizeof(*rc
), GFP_NOFS
);
4156 INIT_LIST_HEAD(&rc
->reloc_roots
);
4157 backref_cache_init(&rc
->backref_cache
);
4158 mapping_tree_init(&rc
->reloc_root_tree
);
4159 extent_io_tree_init(&rc
->processed_blocks
,
4160 fs_info
->btree_inode
->i_mapping
);
4165 * function to relocate all extents in a block group.
4167 int btrfs_relocate_block_group(struct btrfs_root
*extent_root
, u64 group_start
)
4169 struct btrfs_fs_info
*fs_info
= extent_root
->fs_info
;
4170 struct reloc_control
*rc
;
4171 struct inode
*inode
;
4172 struct btrfs_path
*path
;
4177 rc
= alloc_reloc_control(fs_info
);
4181 rc
->extent_root
= extent_root
;
4183 rc
->block_group
= btrfs_lookup_block_group(fs_info
, group_start
);
4184 BUG_ON(!rc
->block_group
);
4186 if (!rc
->block_group
->ro
) {
4187 ret
= btrfs_set_block_group_ro(extent_root
, rc
->block_group
);
4195 path
= btrfs_alloc_path();
4201 inode
= lookup_free_space_inode(fs_info
->tree_root
, rc
->block_group
,
4203 btrfs_free_path(path
);
4206 ret
= delete_block_group_cache(fs_info
, inode
, 0);
4208 ret
= PTR_ERR(inode
);
4210 if (ret
&& ret
!= -ENOENT
) {
4215 rc
->data_inode
= create_reloc_inode(fs_info
, rc
->block_group
);
4216 if (IS_ERR(rc
->data_inode
)) {
4217 err
= PTR_ERR(rc
->data_inode
);
4218 rc
->data_inode
= NULL
;
4222 printk(KERN_INFO
"btrfs: relocating block group %llu flags %llu\n",
4223 rc
->block_group
->key
.objectid
, rc
->block_group
->flags
);
4225 ret
= btrfs_start_delalloc_roots(fs_info
, 0);
4230 btrfs_wait_ordered_roots(fs_info
, -1);
4233 mutex_lock(&fs_info
->cleaner_mutex
);
4234 ret
= relocate_block_group(rc
);
4235 mutex_unlock(&fs_info
->cleaner_mutex
);
4241 if (rc
->extents_found
== 0)
4244 printk(KERN_INFO
"btrfs: found %llu extents\n",
4247 if (rc
->stage
== MOVE_DATA_EXTENTS
&& rc
->found_file_extent
) {
4248 ret
= btrfs_wait_ordered_range(rc
->data_inode
, 0,
4254 invalidate_mapping_pages(rc
->data_inode
->i_mapping
,
4256 rc
->stage
= UPDATE_DATA_PTRS
;
4260 filemap_write_and_wait_range(fs_info
->btree_inode
->i_mapping
,
4261 rc
->block_group
->key
.objectid
,
4262 rc
->block_group
->key
.objectid
+
4263 rc
->block_group
->key
.offset
- 1);
4265 WARN_ON(rc
->block_group
->pinned
> 0);
4266 WARN_ON(rc
->block_group
->reserved
> 0);
4267 WARN_ON(btrfs_block_group_used(&rc
->block_group
->item
) > 0);
4270 btrfs_set_block_group_rw(extent_root
, rc
->block_group
);
4271 iput(rc
->data_inode
);
4272 btrfs_put_block_group(rc
->block_group
);
4277 static noinline_for_stack
int mark_garbage_root(struct btrfs_root
*root
)
4279 struct btrfs_trans_handle
*trans
;
4282 trans
= btrfs_start_transaction(root
->fs_info
->tree_root
, 0);
4284 return PTR_ERR(trans
);
4286 memset(&root
->root_item
.drop_progress
, 0,
4287 sizeof(root
->root_item
.drop_progress
));
4288 root
->root_item
.drop_level
= 0;
4289 btrfs_set_root_refs(&root
->root_item
, 0);
4290 ret
= btrfs_update_root(trans
, root
->fs_info
->tree_root
,
4291 &root
->root_key
, &root
->root_item
);
4293 err
= btrfs_end_transaction(trans
, root
->fs_info
->tree_root
);
4300 * recover relocation interrupted by system crash.
4302 * this function resumes merging reloc trees with corresponding fs trees.
4303 * this is important for keeping the sharing of tree blocks
4305 int btrfs_recover_relocation(struct btrfs_root
*root
)
4307 LIST_HEAD(reloc_roots
);
4308 struct btrfs_key key
;
4309 struct btrfs_root
*fs_root
;
4310 struct btrfs_root
*reloc_root
;
4311 struct btrfs_path
*path
;
4312 struct extent_buffer
*leaf
;
4313 struct reloc_control
*rc
= NULL
;
4314 struct btrfs_trans_handle
*trans
;
4318 path
= btrfs_alloc_path();
4323 key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
4324 key
.type
= BTRFS_ROOT_ITEM_KEY
;
4325 key
.offset
= (u64
)-1;
4328 ret
= btrfs_search_slot(NULL
, root
->fs_info
->tree_root
, &key
,
4335 if (path
->slots
[0] == 0)
4339 leaf
= path
->nodes
[0];
4340 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
4341 btrfs_release_path(path
);
4343 if (key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
||
4344 key
.type
!= BTRFS_ROOT_ITEM_KEY
)
4347 reloc_root
= btrfs_read_fs_root(root
, &key
);
4348 if (IS_ERR(reloc_root
)) {
4349 err
= PTR_ERR(reloc_root
);
4353 list_add(&reloc_root
->root_list
, &reloc_roots
);
4355 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
4356 fs_root
= read_fs_root(root
->fs_info
,
4357 reloc_root
->root_key
.offset
);
4358 if (IS_ERR(fs_root
)) {
4359 ret
= PTR_ERR(fs_root
);
4360 if (ret
!= -ENOENT
) {
4364 ret
= mark_garbage_root(reloc_root
);
4372 if (key
.offset
== 0)
4377 btrfs_release_path(path
);
4379 if (list_empty(&reloc_roots
))
4382 rc
= alloc_reloc_control(root
->fs_info
);
4388 rc
->extent_root
= root
->fs_info
->extent_root
;
4390 set_reloc_control(rc
);
4392 trans
= btrfs_join_transaction(rc
->extent_root
);
4393 if (IS_ERR(trans
)) {
4394 unset_reloc_control(rc
);
4395 err
= PTR_ERR(trans
);
4399 rc
->merge_reloc_tree
= 1;
4401 while (!list_empty(&reloc_roots
)) {
4402 reloc_root
= list_entry(reloc_roots
.next
,
4403 struct btrfs_root
, root_list
);
4404 list_del(&reloc_root
->root_list
);
4406 if (btrfs_root_refs(&reloc_root
->root_item
) == 0) {
4407 list_add_tail(&reloc_root
->root_list
,
4412 fs_root
= read_fs_root(root
->fs_info
,
4413 reloc_root
->root_key
.offset
);
4414 if (IS_ERR(fs_root
)) {
4415 err
= PTR_ERR(fs_root
);
4419 err
= __add_reloc_root(reloc_root
);
4420 BUG_ON(err
< 0); /* -ENOMEM or logic error */
4421 fs_root
->reloc_root
= reloc_root
;
4424 err
= btrfs_commit_transaction(trans
, rc
->extent_root
);
4428 merge_reloc_roots(rc
);
4430 unset_reloc_control(rc
);
4432 trans
= btrfs_join_transaction(rc
->extent_root
);
4434 err
= PTR_ERR(trans
);
4436 err
= btrfs_commit_transaction(trans
, rc
->extent_root
);
4440 if (!list_empty(&reloc_roots
))
4441 free_reloc_roots(&reloc_roots
);
4443 btrfs_free_path(path
);
4446 /* cleanup orphan inode in data relocation tree */
4447 fs_root
= read_fs_root(root
->fs_info
,
4448 BTRFS_DATA_RELOC_TREE_OBJECTID
);
4449 if (IS_ERR(fs_root
))
4450 err
= PTR_ERR(fs_root
);
4452 err
= btrfs_orphan_cleanup(fs_root
);
4458 * helper to add ordered checksum for data relocation.
4460 * cloning checksum properly handles the nodatasum extents.
4461 * it also saves CPU time to re-calculate the checksum.
4463 int btrfs_reloc_clone_csums(struct inode
*inode
, u64 file_pos
, u64 len
)
4465 struct btrfs_ordered_sum
*sums
;
4466 struct btrfs_ordered_extent
*ordered
;
4467 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
4473 ordered
= btrfs_lookup_ordered_extent(inode
, file_pos
);
4474 BUG_ON(ordered
->file_offset
!= file_pos
|| ordered
->len
!= len
);
4476 disk_bytenr
= file_pos
+ BTRFS_I(inode
)->index_cnt
;
4477 ret
= btrfs_lookup_csums_range(root
->fs_info
->csum_root
, disk_bytenr
,
4478 disk_bytenr
+ len
- 1, &list
, 0);
4482 while (!list_empty(&list
)) {
4483 sums
= list_entry(list
.next
, struct btrfs_ordered_sum
, list
);
4484 list_del_init(&sums
->list
);
4487 * We need to offset the new_bytenr based on where the csum is.
4488 * We need to do this because we will read in entire prealloc
4489 * extents but we may have written to say the middle of the
4490 * prealloc extent, so we need to make sure the csum goes with
4491 * the right disk offset.
4493 * We can do this because the data reloc inode refers strictly
4494 * to the on disk bytes, so we don't have to worry about
4495 * disk_len vs real len like with real inodes since it's all
4498 new_bytenr
= ordered
->start
+ (sums
->bytenr
- disk_bytenr
);
4499 sums
->bytenr
= new_bytenr
;
4501 btrfs_add_ordered_sum(inode
, ordered
, sums
);
4504 btrfs_put_ordered_extent(ordered
);
4508 int btrfs_reloc_cow_block(struct btrfs_trans_handle
*trans
,
4509 struct btrfs_root
*root
, struct extent_buffer
*buf
,
4510 struct extent_buffer
*cow
)
4512 struct reloc_control
*rc
;
4513 struct backref_node
*node
;
4518 rc
= root
->fs_info
->reloc_ctl
;
4522 BUG_ON(rc
->stage
== UPDATE_DATA_PTRS
&&
4523 root
->root_key
.objectid
== BTRFS_DATA_RELOC_TREE_OBJECTID
);
4525 level
= btrfs_header_level(buf
);
4526 if (btrfs_header_generation(buf
) <=
4527 btrfs_root_last_snapshot(&root
->root_item
))
4530 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
&&
4531 rc
->create_reloc_tree
) {
4532 WARN_ON(!first_cow
&& level
== 0);
4534 node
= rc
->backref_cache
.path
[level
];
4535 BUG_ON(node
->bytenr
!= buf
->start
&&
4536 node
->new_bytenr
!= buf
->start
);
4538 drop_node_buffer(node
);
4539 extent_buffer_get(cow
);
4541 node
->new_bytenr
= cow
->start
;
4543 if (!node
->pending
) {
4544 list_move_tail(&node
->list
,
4545 &rc
->backref_cache
.pending
[level
]);
4550 __mark_block_processed(rc
, node
);
4552 if (first_cow
&& level
> 0)
4553 rc
->nodes_relocated
+= buf
->len
;
4556 if (level
== 0 && first_cow
&& rc
->stage
== UPDATE_DATA_PTRS
)
4557 ret
= replace_file_extents(trans
, rc
, root
, cow
);
4562 * called before creating snapshot. it calculates metadata reservation
4563 * requried for relocating tree blocks in the snapshot
4565 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle
*trans
,
4566 struct btrfs_pending_snapshot
*pending
,
4567 u64
*bytes_to_reserve
)
4569 struct btrfs_root
*root
;
4570 struct reloc_control
*rc
;
4572 root
= pending
->root
;
4573 if (!root
->reloc_root
)
4576 rc
= root
->fs_info
->reloc_ctl
;
4577 if (!rc
->merge_reloc_tree
)
4580 root
= root
->reloc_root
;
4581 BUG_ON(btrfs_root_refs(&root
->root_item
) == 0);
4583 * relocation is in the stage of merging trees. the space
4584 * used by merging a reloc tree is twice the size of
4585 * relocated tree nodes in the worst case. half for cowing
4586 * the reloc tree, half for cowing the fs tree. the space
4587 * used by cowing the reloc tree will be freed after the
4588 * tree is dropped. if we create snapshot, cowing the fs
4589 * tree may use more space than it frees. so we need
4590 * reserve extra space.
4592 *bytes_to_reserve
+= rc
->nodes_relocated
;
4596 * called after snapshot is created. migrate block reservation
4597 * and create reloc root for the newly created snapshot
4599 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle
*trans
,
4600 struct btrfs_pending_snapshot
*pending
)
4602 struct btrfs_root
*root
= pending
->root
;
4603 struct btrfs_root
*reloc_root
;
4604 struct btrfs_root
*new_root
;
4605 struct reloc_control
*rc
;
4608 if (!root
->reloc_root
)
4611 rc
= root
->fs_info
->reloc_ctl
;
4612 rc
->merging_rsv_size
+= rc
->nodes_relocated
;
4614 if (rc
->merge_reloc_tree
) {
4615 ret
= btrfs_block_rsv_migrate(&pending
->block_rsv
,
4617 rc
->nodes_relocated
);
4622 new_root
= pending
->snap
;
4623 reloc_root
= create_reloc_root(trans
, root
->reloc_root
,
4624 new_root
->root_key
.objectid
);
4625 if (IS_ERR(reloc_root
))
4626 return PTR_ERR(reloc_root
);
4628 ret
= __add_reloc_root(reloc_root
);
4630 new_root
->reloc_root
= reloc_root
;
4632 if (rc
->create_reloc_tree
)
4633 ret
= clone_backref_node(trans
, rc
, root
, reloc_root
);