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
||
575 root_objectid
== BTRFS_UUID_TREE_OBJECTID
||
576 root_objectid
== BTRFS_QUOTA_TREE_OBJECTID
)
581 static struct btrfs_root
*read_fs_root(struct btrfs_fs_info
*fs_info
,
584 struct btrfs_key key
;
586 key
.objectid
= root_objectid
;
587 key
.type
= BTRFS_ROOT_ITEM_KEY
;
588 if (is_cowonly_root(root_objectid
))
591 key
.offset
= (u64
)-1;
593 return btrfs_get_fs_root(fs_info
, &key
, false);
596 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
597 static noinline_for_stack
598 struct btrfs_root
*find_tree_root(struct reloc_control
*rc
,
599 struct extent_buffer
*leaf
,
600 struct btrfs_extent_ref_v0
*ref0
)
602 struct btrfs_root
*root
;
603 u64 root_objectid
= btrfs_ref_root_v0(leaf
, ref0
);
604 u64 generation
= btrfs_ref_generation_v0(leaf
, ref0
);
606 BUG_ON(root_objectid
== BTRFS_TREE_RELOC_OBJECTID
);
608 root
= read_fs_root(rc
->extent_root
->fs_info
, root_objectid
);
609 BUG_ON(IS_ERR(root
));
611 if (root
->ref_cows
&&
612 generation
!= btrfs_root_generation(&root
->root_item
))
619 static noinline_for_stack
620 int find_inline_backref(struct extent_buffer
*leaf
, int slot
,
621 unsigned long *ptr
, unsigned long *end
)
623 struct btrfs_key key
;
624 struct btrfs_extent_item
*ei
;
625 struct btrfs_tree_block_info
*bi
;
628 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
630 item_size
= btrfs_item_size_nr(leaf
, slot
);
631 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
632 if (item_size
< sizeof(*ei
)) {
633 WARN_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
637 ei
= btrfs_item_ptr(leaf
, slot
, struct btrfs_extent_item
);
638 WARN_ON(!(btrfs_extent_flags(leaf
, ei
) &
639 BTRFS_EXTENT_FLAG_TREE_BLOCK
));
641 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
642 item_size
<= sizeof(*ei
) + sizeof(*bi
)) {
643 WARN_ON(item_size
< sizeof(*ei
) + sizeof(*bi
));
646 if (key
.type
== BTRFS_METADATA_ITEM_KEY
&&
647 item_size
<= sizeof(*ei
)) {
648 WARN_ON(item_size
< sizeof(*ei
));
652 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
) {
653 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
654 *ptr
= (unsigned long)(bi
+ 1);
656 *ptr
= (unsigned long)(ei
+ 1);
658 *end
= (unsigned long)ei
+ item_size
;
663 * build backref tree for a given tree block. root of the backref tree
664 * corresponds the tree block, leaves of the backref tree correspond
665 * roots of b-trees that reference the tree block.
667 * the basic idea of this function is check backrefs of a given block
668 * to find upper level blocks that refernece the block, and then check
669 * bakcrefs of these upper level blocks recursively. the recursion stop
670 * when tree root is reached or backrefs for the block is cached.
672 * NOTE: if we find backrefs for a block are cached, we know backrefs
673 * for all upper level blocks that directly/indirectly reference the
674 * block are also cached.
676 static noinline_for_stack
677 struct backref_node
*build_backref_tree(struct reloc_control
*rc
,
678 struct btrfs_key
*node_key
,
679 int level
, u64 bytenr
)
681 struct backref_cache
*cache
= &rc
->backref_cache
;
682 struct btrfs_path
*path1
;
683 struct btrfs_path
*path2
;
684 struct extent_buffer
*eb
;
685 struct btrfs_root
*root
;
686 struct backref_node
*cur
;
687 struct backref_node
*upper
;
688 struct backref_node
*lower
;
689 struct backref_node
*node
= NULL
;
690 struct backref_node
*exist
= NULL
;
691 struct backref_edge
*edge
;
692 struct rb_node
*rb_node
;
693 struct btrfs_key key
;
701 bool need_check
= true;
703 path1
= btrfs_alloc_path();
704 path2
= btrfs_alloc_path();
705 if (!path1
|| !path2
) {
712 node
= alloc_backref_node(cache
);
718 node
->bytenr
= bytenr
;
725 key
.objectid
= cur
->bytenr
;
726 key
.type
= BTRFS_METADATA_ITEM_KEY
;
727 key
.offset
= (u64
)-1;
729 path1
->search_commit_root
= 1;
730 path1
->skip_locking
= 1;
731 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path1
,
737 BUG_ON(!ret
|| !path1
->slots
[0]);
741 WARN_ON(cur
->checked
);
742 if (!list_empty(&cur
->upper
)) {
744 * the backref was added previously when processing
745 * backref of type BTRFS_TREE_BLOCK_REF_KEY
747 BUG_ON(!list_is_singular(&cur
->upper
));
748 edge
= list_entry(cur
->upper
.next
, struct backref_edge
,
750 BUG_ON(!list_empty(&edge
->list
[UPPER
]));
751 exist
= edge
->node
[UPPER
];
753 * add the upper level block to pending list if we need
757 list_add_tail(&edge
->list
[UPPER
], &list
);
764 eb
= path1
->nodes
[0];
767 if (path1
->slots
[0] >= btrfs_header_nritems(eb
)) {
768 ret
= btrfs_next_leaf(rc
->extent_root
, path1
);
775 eb
= path1
->nodes
[0];
778 btrfs_item_key_to_cpu(eb
, &key
, path1
->slots
[0]);
779 if (key
.objectid
!= cur
->bytenr
) {
784 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
||
785 key
.type
== BTRFS_METADATA_ITEM_KEY
) {
786 ret
= find_inline_backref(eb
, path1
->slots
[0],
794 /* update key for inline back ref */
795 struct btrfs_extent_inline_ref
*iref
;
796 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
797 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
798 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
799 WARN_ON(key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
&&
800 key
.type
!= BTRFS_SHARED_BLOCK_REF_KEY
);
804 ((key
.type
== BTRFS_TREE_BLOCK_REF_KEY
&&
805 exist
->owner
== key
.offset
) ||
806 (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
&&
807 exist
->bytenr
== key
.offset
))) {
812 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
813 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
||
814 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
815 if (key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
816 struct btrfs_extent_ref_v0
*ref0
;
817 ref0
= btrfs_item_ptr(eb
, path1
->slots
[0],
818 struct btrfs_extent_ref_v0
);
819 if (key
.objectid
== key
.offset
) {
820 root
= find_tree_root(rc
, eb
, ref0
);
821 if (root
&& !should_ignore_root(root
))
824 list_add(&cur
->list
, &useless
);
827 if (is_cowonly_root(btrfs_ref_root_v0(eb
,
832 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
833 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
) {
835 if (key
.objectid
== key
.offset
) {
837 * only root blocks of reloc trees use
838 * backref of this type.
840 root
= find_reloc_root(rc
, cur
->bytenr
);
846 edge
= alloc_backref_edge(cache
);
851 rb_node
= tree_search(&cache
->rb_root
, key
.offset
);
853 upper
= alloc_backref_node(cache
);
855 free_backref_edge(cache
, edge
);
859 upper
->bytenr
= key
.offset
;
860 upper
->level
= cur
->level
+ 1;
862 * backrefs for the upper level block isn't
863 * cached, add the block to pending list
865 list_add_tail(&edge
->list
[UPPER
], &list
);
867 upper
= rb_entry(rb_node
, struct backref_node
,
869 BUG_ON(!upper
->checked
);
870 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
872 list_add_tail(&edge
->list
[LOWER
], &cur
->upper
);
873 edge
->node
[LOWER
] = cur
;
874 edge
->node
[UPPER
] = upper
;
877 } else if (key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
) {
881 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
882 root
= read_fs_root(rc
->extent_root
->fs_info
, key
.offset
);
891 if (btrfs_root_level(&root
->root_item
) == cur
->level
) {
893 BUG_ON(btrfs_root_bytenr(&root
->root_item
) !=
895 if (should_ignore_root(root
))
896 list_add(&cur
->list
, &useless
);
902 level
= cur
->level
+ 1;
905 * searching the tree to find upper level blocks
906 * reference the block.
908 path2
->search_commit_root
= 1;
909 path2
->skip_locking
= 1;
910 path2
->lowest_level
= level
;
911 ret
= btrfs_search_slot(NULL
, root
, node_key
, path2
, 0, 0);
912 path2
->lowest_level
= 0;
917 if (ret
> 0 && path2
->slots
[level
] > 0)
918 path2
->slots
[level
]--;
920 eb
= path2
->nodes
[level
];
921 WARN_ON(btrfs_node_blockptr(eb
, path2
->slots
[level
]) !=
926 for (; level
< BTRFS_MAX_LEVEL
; level
++) {
927 if (!path2
->nodes
[level
]) {
928 BUG_ON(btrfs_root_bytenr(&root
->root_item
) !=
930 if (should_ignore_root(root
))
931 list_add(&lower
->list
, &useless
);
937 edge
= alloc_backref_edge(cache
);
943 eb
= path2
->nodes
[level
];
944 rb_node
= tree_search(&cache
->rb_root
, eb
->start
);
946 upper
= alloc_backref_node(cache
);
948 free_backref_edge(cache
, edge
);
952 upper
->bytenr
= eb
->start
;
953 upper
->owner
= btrfs_header_owner(eb
);
954 upper
->level
= lower
->level
+ 1;
959 * if we know the block isn't shared
960 * we can void checking its backrefs.
962 if (btrfs_block_can_be_shared(root
, eb
))
968 * add the block to pending list if we
969 * need check its backrefs, we only do this once
970 * while walking up a tree as we will catch
971 * anything else later on.
973 if (!upper
->checked
&& need_check
) {
975 list_add_tail(&edge
->list
[UPPER
],
978 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
980 upper
= rb_entry(rb_node
, struct backref_node
,
982 BUG_ON(!upper
->checked
);
983 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
985 upper
->owner
= btrfs_header_owner(eb
);
987 list_add_tail(&edge
->list
[LOWER
], &lower
->upper
);
988 edge
->node
[LOWER
] = lower
;
989 edge
->node
[UPPER
] = upper
;
996 btrfs_release_path(path2
);
999 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
1009 btrfs_release_path(path1
);
1014 /* the pending list isn't empty, take the first block to process */
1015 if (!list_empty(&list
)) {
1016 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1017 list_del_init(&edge
->list
[UPPER
]);
1018 cur
= edge
->node
[UPPER
];
1023 * everything goes well, connect backref nodes and insert backref nodes
1026 BUG_ON(!node
->checked
);
1027 cowonly
= node
->cowonly
;
1029 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
,
1032 backref_tree_panic(rb_node
, -EEXIST
, node
->bytenr
);
1033 list_add_tail(&node
->lower
, &cache
->leaves
);
1036 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
])
1037 list_add_tail(&edge
->list
[UPPER
], &list
);
1039 while (!list_empty(&list
)) {
1040 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1041 list_del_init(&edge
->list
[UPPER
]);
1042 upper
= edge
->node
[UPPER
];
1043 if (upper
->detached
) {
1044 list_del(&edge
->list
[LOWER
]);
1045 lower
= edge
->node
[LOWER
];
1046 free_backref_edge(cache
, edge
);
1047 if (list_empty(&lower
->upper
))
1048 list_add(&lower
->list
, &useless
);
1052 if (!RB_EMPTY_NODE(&upper
->rb_node
)) {
1053 if (upper
->lowest
) {
1054 list_del_init(&upper
->lower
);
1058 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1062 BUG_ON(!upper
->checked
);
1063 BUG_ON(cowonly
!= upper
->cowonly
);
1065 rb_node
= tree_insert(&cache
->rb_root
, upper
->bytenr
,
1068 backref_tree_panic(rb_node
, -EEXIST
,
1072 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1074 list_for_each_entry(edge
, &upper
->upper
, list
[LOWER
])
1075 list_add_tail(&edge
->list
[UPPER
], &list
);
1078 * process useless backref nodes. backref nodes for tree leaves
1079 * are deleted from the cache. backref nodes for upper level
1080 * tree blocks are left in the cache to avoid unnecessary backref
1083 while (!list_empty(&useless
)) {
1084 upper
= list_entry(useless
.next
, struct backref_node
, list
);
1085 list_del_init(&upper
->list
);
1086 BUG_ON(!list_empty(&upper
->upper
));
1089 if (upper
->lowest
) {
1090 list_del_init(&upper
->lower
);
1093 while (!list_empty(&upper
->lower
)) {
1094 edge
= list_entry(upper
->lower
.next
,
1095 struct backref_edge
, list
[UPPER
]);
1096 list_del(&edge
->list
[UPPER
]);
1097 list_del(&edge
->list
[LOWER
]);
1098 lower
= edge
->node
[LOWER
];
1099 free_backref_edge(cache
, edge
);
1101 if (list_empty(&lower
->upper
))
1102 list_add(&lower
->list
, &useless
);
1104 __mark_block_processed(rc
, upper
);
1105 if (upper
->level
> 0) {
1106 list_add(&upper
->list
, &cache
->detached
);
1107 upper
->detached
= 1;
1109 rb_erase(&upper
->rb_node
, &cache
->rb_root
);
1110 free_backref_node(cache
, upper
);
1114 btrfs_free_path(path1
);
1115 btrfs_free_path(path2
);
1117 while (!list_empty(&useless
)) {
1118 lower
= list_entry(useless
.next
,
1119 struct backref_node
, upper
);
1120 list_del_init(&lower
->upper
);
1123 INIT_LIST_HEAD(&list
);
1125 if (RB_EMPTY_NODE(&upper
->rb_node
)) {
1126 list_splice_tail(&upper
->upper
, &list
);
1127 free_backref_node(cache
, upper
);
1130 if (list_empty(&list
))
1133 edge
= list_entry(list
.next
, struct backref_edge
,
1135 list_del(&edge
->list
[LOWER
]);
1136 upper
= edge
->node
[UPPER
];
1137 free_backref_edge(cache
, edge
);
1139 return ERR_PTR(err
);
1141 BUG_ON(node
&& node
->detached
);
1146 * helper to add backref node for the newly created snapshot.
1147 * the backref node is created by cloning backref node that
1148 * corresponds to root of source tree
1150 static int clone_backref_node(struct btrfs_trans_handle
*trans
,
1151 struct reloc_control
*rc
,
1152 struct btrfs_root
*src
,
1153 struct btrfs_root
*dest
)
1155 struct btrfs_root
*reloc_root
= src
->reloc_root
;
1156 struct backref_cache
*cache
= &rc
->backref_cache
;
1157 struct backref_node
*node
= NULL
;
1158 struct backref_node
*new_node
;
1159 struct backref_edge
*edge
;
1160 struct backref_edge
*new_edge
;
1161 struct rb_node
*rb_node
;
1163 if (cache
->last_trans
> 0)
1164 update_backref_cache(trans
, cache
);
1166 rb_node
= tree_search(&cache
->rb_root
, src
->commit_root
->start
);
1168 node
= rb_entry(rb_node
, struct backref_node
, rb_node
);
1172 BUG_ON(node
->new_bytenr
!= reloc_root
->node
->start
);
1176 rb_node
= tree_search(&cache
->rb_root
,
1177 reloc_root
->commit_root
->start
);
1179 node
= rb_entry(rb_node
, struct backref_node
,
1181 BUG_ON(node
->detached
);
1188 new_node
= alloc_backref_node(cache
);
1192 new_node
->bytenr
= dest
->node
->start
;
1193 new_node
->level
= node
->level
;
1194 new_node
->lowest
= node
->lowest
;
1195 new_node
->checked
= 1;
1196 new_node
->root
= dest
;
1198 if (!node
->lowest
) {
1199 list_for_each_entry(edge
, &node
->lower
, list
[UPPER
]) {
1200 new_edge
= alloc_backref_edge(cache
);
1204 new_edge
->node
[UPPER
] = new_node
;
1205 new_edge
->node
[LOWER
] = edge
->node
[LOWER
];
1206 list_add_tail(&new_edge
->list
[UPPER
],
1210 list_add_tail(&new_node
->lower
, &cache
->leaves
);
1213 rb_node
= tree_insert(&cache
->rb_root
, new_node
->bytenr
,
1214 &new_node
->rb_node
);
1216 backref_tree_panic(rb_node
, -EEXIST
, new_node
->bytenr
);
1218 if (!new_node
->lowest
) {
1219 list_for_each_entry(new_edge
, &new_node
->lower
, list
[UPPER
]) {
1220 list_add_tail(&new_edge
->list
[LOWER
],
1221 &new_edge
->node
[LOWER
]->upper
);
1226 while (!list_empty(&new_node
->lower
)) {
1227 new_edge
= list_entry(new_node
->lower
.next
,
1228 struct backref_edge
, list
[UPPER
]);
1229 list_del(&new_edge
->list
[UPPER
]);
1230 free_backref_edge(cache
, new_edge
);
1232 free_backref_node(cache
, new_node
);
1237 * helper to add 'address of tree root -> reloc tree' mapping
1239 static int __must_check
__add_reloc_root(struct btrfs_root
*root
)
1241 struct rb_node
*rb_node
;
1242 struct mapping_node
*node
;
1243 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1245 node
= kmalloc(sizeof(*node
), GFP_NOFS
);
1249 node
->bytenr
= root
->node
->start
;
1252 spin_lock(&rc
->reloc_root_tree
.lock
);
1253 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1254 node
->bytenr
, &node
->rb_node
);
1255 spin_unlock(&rc
->reloc_root_tree
.lock
);
1257 btrfs_panic(root
->fs_info
, -EEXIST
, "Duplicate root found "
1258 "for start=%llu while inserting into relocation "
1259 "tree\n", node
->bytenr
);
1264 list_add_tail(&root
->root_list
, &rc
->reloc_roots
);
1269 * helper to delete the 'address of tree root -> reloc tree'
1272 static void __del_reloc_root(struct btrfs_root
*root
)
1274 struct rb_node
*rb_node
;
1275 struct mapping_node
*node
= NULL
;
1276 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1278 spin_lock(&rc
->reloc_root_tree
.lock
);
1279 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
,
1282 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
1283 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
1285 spin_unlock(&rc
->reloc_root_tree
.lock
);
1289 BUG_ON((struct btrfs_root
*)node
->data
!= root
);
1291 spin_lock(&root
->fs_info
->trans_lock
);
1292 list_del_init(&root
->root_list
);
1293 spin_unlock(&root
->fs_info
->trans_lock
);
1298 * helper to update the 'address of tree root -> reloc tree'
1301 static int __update_reloc_root(struct btrfs_root
*root
, u64 new_bytenr
)
1303 struct rb_node
*rb_node
;
1304 struct mapping_node
*node
= NULL
;
1305 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1307 spin_lock(&rc
->reloc_root_tree
.lock
);
1308 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
,
1311 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
1312 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
1314 spin_unlock(&rc
->reloc_root_tree
.lock
);
1318 BUG_ON((struct btrfs_root
*)node
->data
!= root
);
1320 spin_lock(&rc
->reloc_root_tree
.lock
);
1321 node
->bytenr
= new_bytenr
;
1322 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1323 node
->bytenr
, &node
->rb_node
);
1324 spin_unlock(&rc
->reloc_root_tree
.lock
);
1326 backref_tree_panic(rb_node
, -EEXIST
, node
->bytenr
);
1330 static struct btrfs_root
*create_reloc_root(struct btrfs_trans_handle
*trans
,
1331 struct btrfs_root
*root
, u64 objectid
)
1333 struct btrfs_root
*reloc_root
;
1334 struct extent_buffer
*eb
;
1335 struct btrfs_root_item
*root_item
;
1336 struct btrfs_key root_key
;
1340 root_item
= kmalloc(sizeof(*root_item
), GFP_NOFS
);
1343 root_key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
1344 root_key
.type
= BTRFS_ROOT_ITEM_KEY
;
1345 root_key
.offset
= objectid
;
1347 if (root
->root_key
.objectid
== objectid
) {
1348 /* called by btrfs_init_reloc_root */
1349 ret
= btrfs_copy_root(trans
, root
, root
->commit_root
, &eb
,
1350 BTRFS_TREE_RELOC_OBJECTID
);
1353 last_snap
= btrfs_root_last_snapshot(&root
->root_item
);
1354 btrfs_set_root_last_snapshot(&root
->root_item
,
1355 trans
->transid
- 1);
1358 * called by btrfs_reloc_post_snapshot_hook.
1359 * the source tree is a reloc tree, all tree blocks
1360 * modified after it was created have RELOC flag
1361 * set in their headers. so it's OK to not update
1362 * the 'last_snapshot'.
1364 ret
= btrfs_copy_root(trans
, root
, root
->node
, &eb
,
1365 BTRFS_TREE_RELOC_OBJECTID
);
1369 memcpy(root_item
, &root
->root_item
, sizeof(*root_item
));
1370 btrfs_set_root_bytenr(root_item
, eb
->start
);
1371 btrfs_set_root_level(root_item
, btrfs_header_level(eb
));
1372 btrfs_set_root_generation(root_item
, trans
->transid
);
1374 if (root
->root_key
.objectid
== objectid
) {
1375 btrfs_set_root_refs(root_item
, 0);
1376 memset(&root_item
->drop_progress
, 0,
1377 sizeof(struct btrfs_disk_key
));
1378 root_item
->drop_level
= 0;
1380 * abuse rtransid, it is safe because it is impossible to
1381 * receive data into a relocation tree.
1383 btrfs_set_root_rtransid(root_item
, last_snap
);
1384 btrfs_set_root_otransid(root_item
, trans
->transid
);
1387 btrfs_tree_unlock(eb
);
1388 free_extent_buffer(eb
);
1390 ret
= btrfs_insert_root(trans
, root
->fs_info
->tree_root
,
1391 &root_key
, root_item
);
1395 reloc_root
= btrfs_read_fs_root(root
->fs_info
->tree_root
, &root_key
);
1396 BUG_ON(IS_ERR(reloc_root
));
1397 reloc_root
->last_trans
= trans
->transid
;
1402 * create reloc tree for a given fs tree. reloc tree is just a
1403 * snapshot of the fs tree with special root objectid.
1405 int btrfs_init_reloc_root(struct btrfs_trans_handle
*trans
,
1406 struct btrfs_root
*root
)
1408 struct btrfs_root
*reloc_root
;
1409 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
1410 struct btrfs_block_rsv
*rsv
;
1414 if (root
->reloc_root
) {
1415 reloc_root
= root
->reloc_root
;
1416 reloc_root
->last_trans
= trans
->transid
;
1420 if (!rc
|| !rc
->create_reloc_tree
||
1421 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1424 if (!trans
->reloc_reserved
) {
1425 rsv
= trans
->block_rsv
;
1426 trans
->block_rsv
= rc
->block_rsv
;
1429 reloc_root
= create_reloc_root(trans
, root
, root
->root_key
.objectid
);
1431 trans
->block_rsv
= rsv
;
1433 ret
= __add_reloc_root(reloc_root
);
1435 root
->reloc_root
= reloc_root
;
1440 * update root item of reloc tree
1442 int btrfs_update_reloc_root(struct btrfs_trans_handle
*trans
,
1443 struct btrfs_root
*root
)
1445 struct btrfs_root
*reloc_root
;
1446 struct btrfs_root_item
*root_item
;
1449 if (!root
->reloc_root
)
1452 reloc_root
= root
->reloc_root
;
1453 root_item
= &reloc_root
->root_item
;
1455 if (root
->fs_info
->reloc_ctl
->merge_reloc_tree
&&
1456 btrfs_root_refs(root_item
) == 0) {
1457 root
->reloc_root
= NULL
;
1458 __del_reloc_root(reloc_root
);
1461 if (reloc_root
->commit_root
!= reloc_root
->node
) {
1462 btrfs_set_root_node(root_item
, reloc_root
->node
);
1463 free_extent_buffer(reloc_root
->commit_root
);
1464 reloc_root
->commit_root
= btrfs_root_node(reloc_root
);
1467 ret
= btrfs_update_root(trans
, root
->fs_info
->tree_root
,
1468 &reloc_root
->root_key
, root_item
);
1476 * helper to find first cached inode with inode number >= objectid
1479 static struct inode
*find_next_inode(struct btrfs_root
*root
, u64 objectid
)
1481 struct rb_node
*node
;
1482 struct rb_node
*prev
;
1483 struct btrfs_inode
*entry
;
1484 struct inode
*inode
;
1486 spin_lock(&root
->inode_lock
);
1488 node
= root
->inode_tree
.rb_node
;
1492 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1494 if (objectid
< btrfs_ino(&entry
->vfs_inode
))
1495 node
= node
->rb_left
;
1496 else if (objectid
> btrfs_ino(&entry
->vfs_inode
))
1497 node
= node
->rb_right
;
1503 entry
= rb_entry(prev
, struct btrfs_inode
, rb_node
);
1504 if (objectid
<= btrfs_ino(&entry
->vfs_inode
)) {
1508 prev
= rb_next(prev
);
1512 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1513 inode
= igrab(&entry
->vfs_inode
);
1515 spin_unlock(&root
->inode_lock
);
1519 objectid
= btrfs_ino(&entry
->vfs_inode
) + 1;
1520 if (cond_resched_lock(&root
->inode_lock
))
1523 node
= rb_next(node
);
1525 spin_unlock(&root
->inode_lock
);
1529 static int in_block_group(u64 bytenr
,
1530 struct btrfs_block_group_cache
*block_group
)
1532 if (bytenr
>= block_group
->key
.objectid
&&
1533 bytenr
< block_group
->key
.objectid
+ block_group
->key
.offset
)
1539 * get new location of data
1541 static int get_new_location(struct inode
*reloc_inode
, u64
*new_bytenr
,
1542 u64 bytenr
, u64 num_bytes
)
1544 struct btrfs_root
*root
= BTRFS_I(reloc_inode
)->root
;
1545 struct btrfs_path
*path
;
1546 struct btrfs_file_extent_item
*fi
;
1547 struct extent_buffer
*leaf
;
1550 path
= btrfs_alloc_path();
1554 bytenr
-= BTRFS_I(reloc_inode
)->index_cnt
;
1555 ret
= btrfs_lookup_file_extent(NULL
, root
, path
, btrfs_ino(reloc_inode
),
1564 leaf
= path
->nodes
[0];
1565 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
1566 struct btrfs_file_extent_item
);
1568 BUG_ON(btrfs_file_extent_offset(leaf
, fi
) ||
1569 btrfs_file_extent_compression(leaf
, fi
) ||
1570 btrfs_file_extent_encryption(leaf
, fi
) ||
1571 btrfs_file_extent_other_encoding(leaf
, fi
));
1573 if (num_bytes
!= btrfs_file_extent_disk_num_bytes(leaf
, fi
)) {
1578 *new_bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1581 btrfs_free_path(path
);
1586 * update file extent items in the tree leaf to point to
1587 * the new locations.
1589 static noinline_for_stack
1590 int replace_file_extents(struct btrfs_trans_handle
*trans
,
1591 struct reloc_control
*rc
,
1592 struct btrfs_root
*root
,
1593 struct extent_buffer
*leaf
)
1595 struct btrfs_key key
;
1596 struct btrfs_file_extent_item
*fi
;
1597 struct inode
*inode
= NULL
;
1609 if (rc
->stage
!= UPDATE_DATA_PTRS
)
1612 /* reloc trees always use full backref */
1613 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1614 parent
= leaf
->start
;
1618 nritems
= btrfs_header_nritems(leaf
);
1619 for (i
= 0; i
< nritems
; i
++) {
1621 btrfs_item_key_to_cpu(leaf
, &key
, i
);
1622 if (key
.type
!= BTRFS_EXTENT_DATA_KEY
)
1624 fi
= btrfs_item_ptr(leaf
, i
, struct btrfs_file_extent_item
);
1625 if (btrfs_file_extent_type(leaf
, fi
) ==
1626 BTRFS_FILE_EXTENT_INLINE
)
1628 bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1629 num_bytes
= btrfs_file_extent_disk_num_bytes(leaf
, fi
);
1632 if (!in_block_group(bytenr
, rc
->block_group
))
1636 * if we are modifying block in fs tree, wait for readpage
1637 * to complete and drop the extent cache
1639 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
) {
1641 inode
= find_next_inode(root
, key
.objectid
);
1643 } else if (inode
&& btrfs_ino(inode
) < key
.objectid
) {
1644 btrfs_add_delayed_iput(inode
);
1645 inode
= find_next_inode(root
, key
.objectid
);
1647 if (inode
&& btrfs_ino(inode
) == key
.objectid
) {
1649 btrfs_file_extent_num_bytes(leaf
, fi
);
1650 WARN_ON(!IS_ALIGNED(key
.offset
,
1652 WARN_ON(!IS_ALIGNED(end
, root
->sectorsize
));
1654 ret
= try_lock_extent(&BTRFS_I(inode
)->io_tree
,
1659 btrfs_drop_extent_cache(inode
, key
.offset
, end
,
1661 unlock_extent(&BTRFS_I(inode
)->io_tree
,
1666 ret
= get_new_location(rc
->data_inode
, &new_bytenr
,
1670 * Don't have to abort since we've not changed anything
1671 * in the file extent yet.
1676 btrfs_set_file_extent_disk_bytenr(leaf
, fi
, new_bytenr
);
1679 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
1680 ret
= btrfs_inc_extent_ref(trans
, root
, new_bytenr
,
1682 btrfs_header_owner(leaf
),
1683 key
.objectid
, key
.offset
, 1);
1685 btrfs_abort_transaction(trans
, root
, ret
);
1689 ret
= btrfs_free_extent(trans
, root
, bytenr
, num_bytes
,
1690 parent
, btrfs_header_owner(leaf
),
1691 key
.objectid
, key
.offset
, 1);
1693 btrfs_abort_transaction(trans
, root
, ret
);
1698 btrfs_mark_buffer_dirty(leaf
);
1700 btrfs_add_delayed_iput(inode
);
1704 static noinline_for_stack
1705 int memcmp_node_keys(struct extent_buffer
*eb
, int slot
,
1706 struct btrfs_path
*path
, int level
)
1708 struct btrfs_disk_key key1
;
1709 struct btrfs_disk_key key2
;
1710 btrfs_node_key(eb
, &key1
, slot
);
1711 btrfs_node_key(path
->nodes
[level
], &key2
, path
->slots
[level
]);
1712 return memcmp(&key1
, &key2
, sizeof(key1
));
1716 * try to replace tree blocks in fs tree with the new blocks
1717 * in reloc tree. tree blocks haven't been modified since the
1718 * reloc tree was create can be replaced.
1720 * if a block was replaced, level of the block + 1 is returned.
1721 * if no block got replaced, 0 is returned. if there are other
1722 * errors, a negative error number is returned.
1724 static noinline_for_stack
1725 int replace_path(struct btrfs_trans_handle
*trans
,
1726 struct btrfs_root
*dest
, struct btrfs_root
*src
,
1727 struct btrfs_path
*path
, struct btrfs_key
*next_key
,
1728 int lowest_level
, int max_level
)
1730 struct extent_buffer
*eb
;
1731 struct extent_buffer
*parent
;
1732 struct btrfs_key key
;
1744 BUG_ON(src
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
);
1745 BUG_ON(dest
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
);
1747 last_snapshot
= btrfs_root_last_snapshot(&src
->root_item
);
1749 slot
= path
->slots
[lowest_level
];
1750 btrfs_node_key_to_cpu(path
->nodes
[lowest_level
], &key
, slot
);
1752 eb
= btrfs_lock_root_node(dest
);
1753 btrfs_set_lock_blocking(eb
);
1754 level
= btrfs_header_level(eb
);
1756 if (level
< lowest_level
) {
1757 btrfs_tree_unlock(eb
);
1758 free_extent_buffer(eb
);
1763 ret
= btrfs_cow_block(trans
, dest
, eb
, NULL
, 0, &eb
);
1766 btrfs_set_lock_blocking(eb
);
1769 next_key
->objectid
= (u64
)-1;
1770 next_key
->type
= (u8
)-1;
1771 next_key
->offset
= (u64
)-1;
1776 level
= btrfs_header_level(parent
);
1777 BUG_ON(level
< lowest_level
);
1779 ret
= btrfs_bin_search(parent
, &key
, level
, &slot
);
1780 if (ret
&& slot
> 0)
1783 if (next_key
&& slot
+ 1 < btrfs_header_nritems(parent
))
1784 btrfs_node_key_to_cpu(parent
, next_key
, slot
+ 1);
1786 old_bytenr
= btrfs_node_blockptr(parent
, slot
);
1787 blocksize
= btrfs_level_size(dest
, level
- 1);
1788 old_ptr_gen
= btrfs_node_ptr_generation(parent
, slot
);
1790 if (level
<= max_level
) {
1791 eb
= path
->nodes
[level
];
1792 new_bytenr
= btrfs_node_blockptr(eb
,
1793 path
->slots
[level
]);
1794 new_ptr_gen
= btrfs_node_ptr_generation(eb
,
1795 path
->slots
[level
]);
1801 if (WARN_ON(new_bytenr
> 0 && new_bytenr
== old_bytenr
)) {
1806 if (new_bytenr
== 0 || old_ptr_gen
> last_snapshot
||
1807 memcmp_node_keys(parent
, slot
, path
, level
)) {
1808 if (level
<= lowest_level
) {
1813 eb
= read_tree_block(dest
, old_bytenr
, blocksize
,
1815 if (!eb
|| !extent_buffer_uptodate(eb
)) {
1816 ret
= (!eb
) ? -ENOMEM
: -EIO
;
1817 free_extent_buffer(eb
);
1820 btrfs_tree_lock(eb
);
1822 ret
= btrfs_cow_block(trans
, dest
, eb
, parent
,
1826 btrfs_set_lock_blocking(eb
);
1828 btrfs_tree_unlock(parent
);
1829 free_extent_buffer(parent
);
1836 btrfs_tree_unlock(parent
);
1837 free_extent_buffer(parent
);
1842 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
1843 path
->slots
[level
]);
1844 btrfs_release_path(path
);
1846 path
->lowest_level
= level
;
1847 ret
= btrfs_search_slot(trans
, src
, &key
, path
, 0, 1);
1848 path
->lowest_level
= 0;
1852 * swap blocks in fs tree and reloc tree.
1854 btrfs_set_node_blockptr(parent
, slot
, new_bytenr
);
1855 btrfs_set_node_ptr_generation(parent
, slot
, new_ptr_gen
);
1856 btrfs_mark_buffer_dirty(parent
);
1858 btrfs_set_node_blockptr(path
->nodes
[level
],
1859 path
->slots
[level
], old_bytenr
);
1860 btrfs_set_node_ptr_generation(path
->nodes
[level
],
1861 path
->slots
[level
], old_ptr_gen
);
1862 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
1864 ret
= btrfs_inc_extent_ref(trans
, src
, old_bytenr
, blocksize
,
1865 path
->nodes
[level
]->start
,
1866 src
->root_key
.objectid
, level
- 1, 0,
1869 ret
= btrfs_inc_extent_ref(trans
, dest
, new_bytenr
, blocksize
,
1870 0, dest
->root_key
.objectid
, level
- 1,
1874 ret
= btrfs_free_extent(trans
, src
, new_bytenr
, blocksize
,
1875 path
->nodes
[level
]->start
,
1876 src
->root_key
.objectid
, level
- 1, 0,
1880 ret
= btrfs_free_extent(trans
, dest
, old_bytenr
, blocksize
,
1881 0, dest
->root_key
.objectid
, level
- 1,
1885 btrfs_unlock_up_safe(path
, 0);
1890 btrfs_tree_unlock(parent
);
1891 free_extent_buffer(parent
);
1896 * helper to find next relocated block in reloc tree
1898 static noinline_for_stack
1899 int walk_up_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1902 struct extent_buffer
*eb
;
1907 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1909 for (i
= 0; i
< *level
; i
++) {
1910 free_extent_buffer(path
->nodes
[i
]);
1911 path
->nodes
[i
] = NULL
;
1914 for (i
= *level
; i
< BTRFS_MAX_LEVEL
&& path
->nodes
[i
]; i
++) {
1915 eb
= path
->nodes
[i
];
1916 nritems
= btrfs_header_nritems(eb
);
1917 while (path
->slots
[i
] + 1 < nritems
) {
1919 if (btrfs_node_ptr_generation(eb
, path
->slots
[i
]) <=
1926 free_extent_buffer(path
->nodes
[i
]);
1927 path
->nodes
[i
] = NULL
;
1933 * walk down reloc tree to find relocated block of lowest level
1935 static noinline_for_stack
1936 int walk_down_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1939 struct extent_buffer
*eb
= NULL
;
1947 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1949 for (i
= *level
; i
> 0; i
--) {
1950 eb
= path
->nodes
[i
];
1951 nritems
= btrfs_header_nritems(eb
);
1952 while (path
->slots
[i
] < nritems
) {
1953 ptr_gen
= btrfs_node_ptr_generation(eb
, path
->slots
[i
]);
1954 if (ptr_gen
> last_snapshot
)
1958 if (path
->slots
[i
] >= nritems
) {
1969 bytenr
= btrfs_node_blockptr(eb
, path
->slots
[i
]);
1970 blocksize
= btrfs_level_size(root
, i
- 1);
1971 eb
= read_tree_block(root
, bytenr
, blocksize
, ptr_gen
);
1972 if (!eb
|| !extent_buffer_uptodate(eb
)) {
1973 free_extent_buffer(eb
);
1976 BUG_ON(btrfs_header_level(eb
) != i
- 1);
1977 path
->nodes
[i
- 1] = eb
;
1978 path
->slots
[i
- 1] = 0;
1984 * invalidate extent cache for file extents whose key in range of
1985 * [min_key, max_key)
1987 static int invalidate_extent_cache(struct btrfs_root
*root
,
1988 struct btrfs_key
*min_key
,
1989 struct btrfs_key
*max_key
)
1991 struct inode
*inode
= NULL
;
1996 objectid
= min_key
->objectid
;
2001 if (objectid
> max_key
->objectid
)
2004 inode
= find_next_inode(root
, objectid
);
2007 ino
= btrfs_ino(inode
);
2009 if (ino
> max_key
->objectid
) {
2015 if (!S_ISREG(inode
->i_mode
))
2018 if (unlikely(min_key
->objectid
== ino
)) {
2019 if (min_key
->type
> BTRFS_EXTENT_DATA_KEY
)
2021 if (min_key
->type
< BTRFS_EXTENT_DATA_KEY
)
2024 start
= min_key
->offset
;
2025 WARN_ON(!IS_ALIGNED(start
, root
->sectorsize
));
2031 if (unlikely(max_key
->objectid
== ino
)) {
2032 if (max_key
->type
< BTRFS_EXTENT_DATA_KEY
)
2034 if (max_key
->type
> BTRFS_EXTENT_DATA_KEY
) {
2037 if (max_key
->offset
== 0)
2039 end
= max_key
->offset
;
2040 WARN_ON(!IS_ALIGNED(end
, root
->sectorsize
));
2047 /* the lock_extent waits for readpage to complete */
2048 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2049 btrfs_drop_extent_cache(inode
, start
, end
, 1);
2050 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2055 static int find_next_key(struct btrfs_path
*path
, int level
,
2056 struct btrfs_key
*key
)
2059 while (level
< BTRFS_MAX_LEVEL
) {
2060 if (!path
->nodes
[level
])
2062 if (path
->slots
[level
] + 1 <
2063 btrfs_header_nritems(path
->nodes
[level
])) {
2064 btrfs_node_key_to_cpu(path
->nodes
[level
], key
,
2065 path
->slots
[level
] + 1);
2074 * merge the relocated tree blocks in reloc tree with corresponding
2077 static noinline_for_stack
int merge_reloc_root(struct reloc_control
*rc
,
2078 struct btrfs_root
*root
)
2080 LIST_HEAD(inode_list
);
2081 struct btrfs_key key
;
2082 struct btrfs_key next_key
;
2083 struct btrfs_trans_handle
*trans
= NULL
;
2084 struct btrfs_root
*reloc_root
;
2085 struct btrfs_root_item
*root_item
;
2086 struct btrfs_path
*path
;
2087 struct extent_buffer
*leaf
;
2095 path
= btrfs_alloc_path();
2100 reloc_root
= root
->reloc_root
;
2101 root_item
= &reloc_root
->root_item
;
2103 if (btrfs_disk_key_objectid(&root_item
->drop_progress
) == 0) {
2104 level
= btrfs_root_level(root_item
);
2105 extent_buffer_get(reloc_root
->node
);
2106 path
->nodes
[level
] = reloc_root
->node
;
2107 path
->slots
[level
] = 0;
2109 btrfs_disk_key_to_cpu(&key
, &root_item
->drop_progress
);
2111 level
= root_item
->drop_level
;
2113 path
->lowest_level
= level
;
2114 ret
= btrfs_search_slot(NULL
, reloc_root
, &key
, path
, 0, 0);
2115 path
->lowest_level
= 0;
2117 btrfs_free_path(path
);
2121 btrfs_node_key_to_cpu(path
->nodes
[level
], &next_key
,
2122 path
->slots
[level
]);
2123 WARN_ON(memcmp(&key
, &next_key
, sizeof(key
)));
2125 btrfs_unlock_up_safe(path
, 0);
2128 min_reserved
= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2129 memset(&next_key
, 0, sizeof(next_key
));
2132 ret
= btrfs_block_rsv_refill(root
, rc
->block_rsv
, min_reserved
,
2133 BTRFS_RESERVE_FLUSH_ALL
);
2138 trans
= btrfs_start_transaction(root
, 0);
2139 if (IS_ERR(trans
)) {
2140 err
= PTR_ERR(trans
);
2144 trans
->block_rsv
= rc
->block_rsv
;
2149 ret
= walk_down_reloc_tree(reloc_root
, path
, &level
);
2157 if (!find_next_key(path
, level
, &key
) &&
2158 btrfs_comp_cpu_keys(&next_key
, &key
) >= 0) {
2161 ret
= replace_path(trans
, root
, reloc_root
, path
,
2162 &next_key
, level
, max_level
);
2171 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
2172 path
->slots
[level
]);
2176 ret
= walk_up_reloc_tree(reloc_root
, path
, &level
);
2182 * save the merging progress in the drop_progress.
2183 * this is OK since root refs == 1 in this case.
2185 btrfs_node_key(path
->nodes
[level
], &root_item
->drop_progress
,
2186 path
->slots
[level
]);
2187 root_item
->drop_level
= level
;
2189 btrfs_end_transaction_throttle(trans
, root
);
2192 btrfs_btree_balance_dirty(root
);
2194 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2195 invalidate_extent_cache(root
, &key
, &next_key
);
2199 * handle the case only one block in the fs tree need to be
2200 * relocated and the block is tree root.
2202 leaf
= btrfs_lock_root_node(root
);
2203 ret
= btrfs_cow_block(trans
, root
, leaf
, NULL
, 0, &leaf
);
2204 btrfs_tree_unlock(leaf
);
2205 free_extent_buffer(leaf
);
2209 btrfs_free_path(path
);
2212 memset(&root_item
->drop_progress
, 0,
2213 sizeof(root_item
->drop_progress
));
2214 root_item
->drop_level
= 0;
2215 btrfs_set_root_refs(root_item
, 0);
2216 btrfs_update_reloc_root(trans
, root
);
2220 btrfs_end_transaction_throttle(trans
, root
);
2222 btrfs_btree_balance_dirty(root
);
2224 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2225 invalidate_extent_cache(root
, &key
, &next_key
);
2230 static noinline_for_stack
2231 int prepare_to_merge(struct reloc_control
*rc
, int err
)
2233 struct btrfs_root
*root
= rc
->extent_root
;
2234 struct btrfs_root
*reloc_root
;
2235 struct btrfs_trans_handle
*trans
;
2236 LIST_HEAD(reloc_roots
);
2240 mutex_lock(&root
->fs_info
->reloc_mutex
);
2241 rc
->merging_rsv_size
+= root
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2242 rc
->merging_rsv_size
+= rc
->nodes_relocated
* 2;
2243 mutex_unlock(&root
->fs_info
->reloc_mutex
);
2247 num_bytes
= rc
->merging_rsv_size
;
2248 ret
= btrfs_block_rsv_add(root
, rc
->block_rsv
, num_bytes
,
2249 BTRFS_RESERVE_FLUSH_ALL
);
2254 trans
= btrfs_join_transaction(rc
->extent_root
);
2255 if (IS_ERR(trans
)) {
2257 btrfs_block_rsv_release(rc
->extent_root
,
2258 rc
->block_rsv
, num_bytes
);
2259 return PTR_ERR(trans
);
2263 if (num_bytes
!= rc
->merging_rsv_size
) {
2264 btrfs_end_transaction(trans
, rc
->extent_root
);
2265 btrfs_block_rsv_release(rc
->extent_root
,
2266 rc
->block_rsv
, num_bytes
);
2271 rc
->merge_reloc_tree
= 1;
2273 while (!list_empty(&rc
->reloc_roots
)) {
2274 reloc_root
= list_entry(rc
->reloc_roots
.next
,
2275 struct btrfs_root
, root_list
);
2276 list_del_init(&reloc_root
->root_list
);
2278 root
= read_fs_root(reloc_root
->fs_info
,
2279 reloc_root
->root_key
.offset
);
2280 BUG_ON(IS_ERR(root
));
2281 BUG_ON(root
->reloc_root
!= reloc_root
);
2284 * set reference count to 1, so btrfs_recover_relocation
2285 * knows it should resumes merging
2288 btrfs_set_root_refs(&reloc_root
->root_item
, 1);
2289 btrfs_update_reloc_root(trans
, root
);
2291 list_add(&reloc_root
->root_list
, &reloc_roots
);
2294 list_splice(&reloc_roots
, &rc
->reloc_roots
);
2297 btrfs_commit_transaction(trans
, rc
->extent_root
);
2299 btrfs_end_transaction(trans
, rc
->extent_root
);
2303 static noinline_for_stack
2304 void free_reloc_roots(struct list_head
*list
)
2306 struct btrfs_root
*reloc_root
;
2308 while (!list_empty(list
)) {
2309 reloc_root
= list_entry(list
->next
, struct btrfs_root
,
2311 __del_reloc_root(reloc_root
);
2312 free_extent_buffer(reloc_root
->node
);
2313 free_extent_buffer(reloc_root
->commit_root
);
2318 static noinline_for_stack
2319 int merge_reloc_roots(struct reloc_control
*rc
)
2321 struct btrfs_trans_handle
*trans
;
2322 struct btrfs_root
*root
;
2323 struct btrfs_root
*reloc_root
;
2327 LIST_HEAD(reloc_roots
);
2331 root
= rc
->extent_root
;
2334 * this serializes us with btrfs_record_root_in_transaction,
2335 * we have to make sure nobody is in the middle of
2336 * adding their roots to the list while we are
2339 mutex_lock(&root
->fs_info
->reloc_mutex
);
2340 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
2341 mutex_unlock(&root
->fs_info
->reloc_mutex
);
2343 while (!list_empty(&reloc_roots
)) {
2345 reloc_root
= list_entry(reloc_roots
.next
,
2346 struct btrfs_root
, root_list
);
2348 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
2349 root
= read_fs_root(reloc_root
->fs_info
,
2350 reloc_root
->root_key
.offset
);
2351 BUG_ON(IS_ERR(root
));
2352 BUG_ON(root
->reloc_root
!= reloc_root
);
2354 ret
= merge_reloc_root(rc
, root
);
2356 __del_reloc_root(reloc_root
);
2357 free_extent_buffer(reloc_root
->node
);
2358 free_extent_buffer(reloc_root
->commit_root
);
2363 list_del_init(&reloc_root
->root_list
);
2367 * we keep the old last snapshod transid in rtranid when we
2368 * created the relocation tree.
2370 last_snap
= btrfs_root_rtransid(&reloc_root
->root_item
);
2371 otransid
= btrfs_root_otransid(&reloc_root
->root_item
);
2372 objectid
= reloc_root
->root_key
.offset
;
2374 ret
= btrfs_drop_snapshot(reloc_root
, rc
->block_rsv
, 0, 1);
2376 if (list_empty(&reloc_root
->root_list
))
2377 list_add_tail(&reloc_root
->root_list
,
2382 * recover the last snapshot tranid to avoid
2383 * the space balance break NOCOW.
2385 root
= read_fs_root(rc
->extent_root
->fs_info
,
2390 trans
= btrfs_join_transaction(root
);
2391 BUG_ON(IS_ERR(trans
));
2393 /* Check if the fs/file tree was snapshoted or not. */
2394 if (btrfs_root_last_snapshot(&root
->root_item
) ==
2396 btrfs_set_root_last_snapshot(&root
->root_item
,
2399 btrfs_end_transaction(trans
, root
);
2409 btrfs_std_error(root
->fs_info
, ret
);
2410 if (!list_empty(&reloc_roots
))
2411 free_reloc_roots(&reloc_roots
);
2413 /* new reloc root may be added */
2414 mutex_lock(&root
->fs_info
->reloc_mutex
);
2415 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
2416 mutex_unlock(&root
->fs_info
->reloc_mutex
);
2417 if (!list_empty(&reloc_roots
))
2418 free_reloc_roots(&reloc_roots
);
2421 BUG_ON(!RB_EMPTY_ROOT(&rc
->reloc_root_tree
.rb_root
));
2425 static void free_block_list(struct rb_root
*blocks
)
2427 struct tree_block
*block
;
2428 struct rb_node
*rb_node
;
2429 while ((rb_node
= rb_first(blocks
))) {
2430 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2431 rb_erase(rb_node
, blocks
);
2436 static int record_reloc_root_in_trans(struct btrfs_trans_handle
*trans
,
2437 struct btrfs_root
*reloc_root
)
2439 struct btrfs_root
*root
;
2441 if (reloc_root
->last_trans
== trans
->transid
)
2444 root
= read_fs_root(reloc_root
->fs_info
, reloc_root
->root_key
.offset
);
2445 BUG_ON(IS_ERR(root
));
2446 BUG_ON(root
->reloc_root
!= reloc_root
);
2448 return btrfs_record_root_in_trans(trans
, root
);
2451 static noinline_for_stack
2452 struct btrfs_root
*select_reloc_root(struct btrfs_trans_handle
*trans
,
2453 struct reloc_control
*rc
,
2454 struct backref_node
*node
,
2455 struct backref_edge
*edges
[], int *nr
)
2457 struct backref_node
*next
;
2458 struct btrfs_root
*root
;
2464 next
= walk_up_backref(next
, edges
, &index
);
2467 BUG_ON(!root
->ref_cows
);
2469 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
2470 record_reloc_root_in_trans(trans
, root
);
2474 btrfs_record_root_in_trans(trans
, root
);
2475 root
= root
->reloc_root
;
2477 if (next
->new_bytenr
!= root
->node
->start
) {
2478 BUG_ON(next
->new_bytenr
);
2479 BUG_ON(!list_empty(&next
->list
));
2480 next
->new_bytenr
= root
->node
->start
;
2482 list_add_tail(&next
->list
,
2483 &rc
->backref_cache
.changed
);
2484 __mark_block_processed(rc
, next
);
2490 next
= walk_down_backref(edges
, &index
);
2491 if (!next
|| next
->level
<= node
->level
)
2499 /* setup backref node path for btrfs_reloc_cow_block */
2501 rc
->backref_cache
.path
[next
->level
] = next
;
2504 next
= edges
[index
]->node
[UPPER
];
2510 * select a tree root for relocation. return NULL if the block
2511 * is reference counted. we should use do_relocation() in this
2512 * case. return a tree root pointer if the block isn't reference
2513 * counted. return -ENOENT if the block is root of reloc tree.
2515 static noinline_for_stack
2516 struct btrfs_root
*select_one_root(struct btrfs_trans_handle
*trans
,
2517 struct backref_node
*node
)
2519 struct backref_node
*next
;
2520 struct btrfs_root
*root
;
2521 struct btrfs_root
*fs_root
= NULL
;
2522 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2528 next
= walk_up_backref(next
, edges
, &index
);
2532 /* no other choice for non-references counted tree */
2533 if (!root
->ref_cows
)
2536 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
)
2542 next
= walk_down_backref(edges
, &index
);
2543 if (!next
|| next
->level
<= node
->level
)
2548 return ERR_PTR(-ENOENT
);
2552 static noinline_for_stack
2553 u64
calcu_metadata_size(struct reloc_control
*rc
,
2554 struct backref_node
*node
, int reserve
)
2556 struct backref_node
*next
= node
;
2557 struct backref_edge
*edge
;
2558 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2562 BUG_ON(reserve
&& node
->processed
);
2567 if (next
->processed
&& (reserve
|| next
!= node
))
2570 num_bytes
+= btrfs_level_size(rc
->extent_root
,
2573 if (list_empty(&next
->upper
))
2576 edge
= list_entry(next
->upper
.next
,
2577 struct backref_edge
, list
[LOWER
]);
2578 edges
[index
++] = edge
;
2579 next
= edge
->node
[UPPER
];
2581 next
= walk_down_backref(edges
, &index
);
2586 static int reserve_metadata_space(struct btrfs_trans_handle
*trans
,
2587 struct reloc_control
*rc
,
2588 struct backref_node
*node
)
2590 struct btrfs_root
*root
= rc
->extent_root
;
2594 num_bytes
= calcu_metadata_size(rc
, node
, 1) * 2;
2596 trans
->block_rsv
= rc
->block_rsv
;
2597 ret
= btrfs_block_rsv_add(root
, rc
->block_rsv
, num_bytes
,
2598 BTRFS_RESERVE_FLUSH_ALL
);
2601 rc
->commit_transaction
= 1;
2608 static void release_metadata_space(struct reloc_control
*rc
,
2609 struct backref_node
*node
)
2611 u64 num_bytes
= calcu_metadata_size(rc
, node
, 0) * 2;
2612 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, num_bytes
);
2616 * relocate a block tree, and then update pointers in upper level
2617 * blocks that reference the block to point to the new location.
2619 * if called by link_to_upper, the block has already been relocated.
2620 * in that case this function just updates pointers.
2622 static int do_relocation(struct btrfs_trans_handle
*trans
,
2623 struct reloc_control
*rc
,
2624 struct backref_node
*node
,
2625 struct btrfs_key
*key
,
2626 struct btrfs_path
*path
, int lowest
)
2628 struct backref_node
*upper
;
2629 struct backref_edge
*edge
;
2630 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2631 struct btrfs_root
*root
;
2632 struct extent_buffer
*eb
;
2641 BUG_ON(lowest
&& node
->eb
);
2643 path
->lowest_level
= node
->level
+ 1;
2644 rc
->backref_cache
.path
[node
->level
] = node
;
2645 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
]) {
2648 upper
= edge
->node
[UPPER
];
2649 root
= select_reloc_root(trans
, rc
, upper
, edges
, &nr
);
2652 if (upper
->eb
&& !upper
->locked
) {
2654 ret
= btrfs_bin_search(upper
->eb
, key
,
2655 upper
->level
, &slot
);
2657 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2658 if (node
->eb
->start
== bytenr
)
2661 drop_node_buffer(upper
);
2665 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2673 upper
->eb
= path
->nodes
[upper
->level
];
2674 path
->nodes
[upper
->level
] = NULL
;
2676 BUG_ON(upper
->eb
!= path
->nodes
[upper
->level
]);
2680 path
->locks
[upper
->level
] = 0;
2682 slot
= path
->slots
[upper
->level
];
2683 btrfs_release_path(path
);
2685 ret
= btrfs_bin_search(upper
->eb
, key
, upper
->level
,
2690 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2692 BUG_ON(bytenr
!= node
->bytenr
);
2694 if (node
->eb
->start
== bytenr
)
2698 blocksize
= btrfs_level_size(root
, node
->level
);
2699 generation
= btrfs_node_ptr_generation(upper
->eb
, slot
);
2700 eb
= read_tree_block(root
, bytenr
, blocksize
, generation
);
2701 if (!eb
|| !extent_buffer_uptodate(eb
)) {
2702 free_extent_buffer(eb
);
2706 btrfs_tree_lock(eb
);
2707 btrfs_set_lock_blocking(eb
);
2710 ret
= btrfs_cow_block(trans
, root
, eb
, upper
->eb
,
2712 btrfs_tree_unlock(eb
);
2713 free_extent_buffer(eb
);
2718 BUG_ON(node
->eb
!= eb
);
2720 btrfs_set_node_blockptr(upper
->eb
, slot
,
2722 btrfs_set_node_ptr_generation(upper
->eb
, slot
,
2724 btrfs_mark_buffer_dirty(upper
->eb
);
2726 ret
= btrfs_inc_extent_ref(trans
, root
,
2727 node
->eb
->start
, blocksize
,
2729 btrfs_header_owner(upper
->eb
),
2733 ret
= btrfs_drop_subtree(trans
, root
, eb
, upper
->eb
);
2737 if (!upper
->pending
)
2738 drop_node_buffer(upper
);
2740 unlock_node_buffer(upper
);
2745 if (!err
&& node
->pending
) {
2746 drop_node_buffer(node
);
2747 list_move_tail(&node
->list
, &rc
->backref_cache
.changed
);
2751 path
->lowest_level
= 0;
2752 BUG_ON(err
== -ENOSPC
);
2756 static int link_to_upper(struct btrfs_trans_handle
*trans
,
2757 struct reloc_control
*rc
,
2758 struct backref_node
*node
,
2759 struct btrfs_path
*path
)
2761 struct btrfs_key key
;
2763 btrfs_node_key_to_cpu(node
->eb
, &key
, 0);
2764 return do_relocation(trans
, rc
, node
, &key
, path
, 0);
2767 static int finish_pending_nodes(struct btrfs_trans_handle
*trans
,
2768 struct reloc_control
*rc
,
2769 struct btrfs_path
*path
, int err
)
2772 struct backref_cache
*cache
= &rc
->backref_cache
;
2773 struct backref_node
*node
;
2777 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
2778 while (!list_empty(&cache
->pending
[level
])) {
2779 node
= list_entry(cache
->pending
[level
].next
,
2780 struct backref_node
, list
);
2781 list_move_tail(&node
->list
, &list
);
2782 BUG_ON(!node
->pending
);
2785 ret
= link_to_upper(trans
, rc
, node
, path
);
2790 list_splice_init(&list
, &cache
->pending
[level
]);
2795 static void mark_block_processed(struct reloc_control
*rc
,
2796 u64 bytenr
, u32 blocksize
)
2798 set_extent_bits(&rc
->processed_blocks
, bytenr
, bytenr
+ blocksize
- 1,
2799 EXTENT_DIRTY
, GFP_NOFS
);
2802 static void __mark_block_processed(struct reloc_control
*rc
,
2803 struct backref_node
*node
)
2806 if (node
->level
== 0 ||
2807 in_block_group(node
->bytenr
, rc
->block_group
)) {
2808 blocksize
= btrfs_level_size(rc
->extent_root
, node
->level
);
2809 mark_block_processed(rc
, node
->bytenr
, blocksize
);
2811 node
->processed
= 1;
2815 * mark a block and all blocks directly/indirectly reference the block
2818 static void update_processed_blocks(struct reloc_control
*rc
,
2819 struct backref_node
*node
)
2821 struct backref_node
*next
= node
;
2822 struct backref_edge
*edge
;
2823 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2829 if (next
->processed
)
2832 __mark_block_processed(rc
, next
);
2834 if (list_empty(&next
->upper
))
2837 edge
= list_entry(next
->upper
.next
,
2838 struct backref_edge
, list
[LOWER
]);
2839 edges
[index
++] = edge
;
2840 next
= edge
->node
[UPPER
];
2842 next
= walk_down_backref(edges
, &index
);
2846 static int tree_block_processed(u64 bytenr
, u32 blocksize
,
2847 struct reloc_control
*rc
)
2849 if (test_range_bit(&rc
->processed_blocks
, bytenr
,
2850 bytenr
+ blocksize
- 1, EXTENT_DIRTY
, 1, NULL
))
2855 static int get_tree_block_key(struct reloc_control
*rc
,
2856 struct tree_block
*block
)
2858 struct extent_buffer
*eb
;
2860 BUG_ON(block
->key_ready
);
2861 eb
= read_tree_block(rc
->extent_root
, block
->bytenr
,
2862 block
->key
.objectid
, block
->key
.offset
);
2863 if (!eb
|| !extent_buffer_uptodate(eb
)) {
2864 free_extent_buffer(eb
);
2867 WARN_ON(btrfs_header_level(eb
) != block
->level
);
2868 if (block
->level
== 0)
2869 btrfs_item_key_to_cpu(eb
, &block
->key
, 0);
2871 btrfs_node_key_to_cpu(eb
, &block
->key
, 0);
2872 free_extent_buffer(eb
);
2873 block
->key_ready
= 1;
2877 static int reada_tree_block(struct reloc_control
*rc
,
2878 struct tree_block
*block
)
2880 BUG_ON(block
->key_ready
);
2881 if (block
->key
.type
== BTRFS_METADATA_ITEM_KEY
)
2882 readahead_tree_block(rc
->extent_root
, block
->bytenr
,
2883 block
->key
.objectid
,
2884 rc
->extent_root
->leafsize
);
2886 readahead_tree_block(rc
->extent_root
, block
->bytenr
,
2887 block
->key
.objectid
, block
->key
.offset
);
2892 * helper function to relocate a tree block
2894 static int relocate_tree_block(struct btrfs_trans_handle
*trans
,
2895 struct reloc_control
*rc
,
2896 struct backref_node
*node
,
2897 struct btrfs_key
*key
,
2898 struct btrfs_path
*path
)
2900 struct btrfs_root
*root
;
2907 BUG_ON(node
->processed
);
2908 root
= select_one_root(trans
, node
);
2909 if (root
== ERR_PTR(-ENOENT
)) {
2910 update_processed_blocks(rc
, node
);
2914 if (!root
|| root
->ref_cows
) {
2915 ret
= reserve_metadata_space(trans
, rc
, node
);
2922 if (root
->ref_cows
) {
2923 BUG_ON(node
->new_bytenr
);
2924 BUG_ON(!list_empty(&node
->list
));
2925 btrfs_record_root_in_trans(trans
, root
);
2926 root
= root
->reloc_root
;
2927 node
->new_bytenr
= root
->node
->start
;
2929 list_add_tail(&node
->list
, &rc
->backref_cache
.changed
);
2931 path
->lowest_level
= node
->level
;
2932 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2933 btrfs_release_path(path
);
2938 update_processed_blocks(rc
, node
);
2940 ret
= do_relocation(trans
, rc
, node
, key
, path
, 1);
2943 if (ret
|| node
->level
== 0 || node
->cowonly
) {
2945 release_metadata_space(rc
, node
);
2946 remove_backref_node(&rc
->backref_cache
, node
);
2952 * relocate a list of blocks
2954 static noinline_for_stack
2955 int relocate_tree_blocks(struct btrfs_trans_handle
*trans
,
2956 struct reloc_control
*rc
, struct rb_root
*blocks
)
2958 struct backref_node
*node
;
2959 struct btrfs_path
*path
;
2960 struct tree_block
*block
;
2961 struct rb_node
*rb_node
;
2965 path
= btrfs_alloc_path();
2968 goto out_free_blocks
;
2971 rb_node
= rb_first(blocks
);
2973 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2974 if (!block
->key_ready
)
2975 reada_tree_block(rc
, block
);
2976 rb_node
= rb_next(rb_node
);
2979 rb_node
= rb_first(blocks
);
2981 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2982 if (!block
->key_ready
) {
2983 err
= get_tree_block_key(rc
, block
);
2987 rb_node
= rb_next(rb_node
);
2990 rb_node
= rb_first(blocks
);
2992 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2994 node
= build_backref_tree(rc
, &block
->key
,
2995 block
->level
, block
->bytenr
);
2997 err
= PTR_ERR(node
);
3001 ret
= relocate_tree_block(trans
, rc
, node
, &block
->key
,
3004 if (ret
!= -EAGAIN
|| rb_node
== rb_first(blocks
))
3008 rb_node
= rb_next(rb_node
);
3011 err
= finish_pending_nodes(trans
, rc
, path
, err
);
3014 btrfs_free_path(path
);
3016 free_block_list(blocks
);
3020 static noinline_for_stack
3021 int prealloc_file_extent_cluster(struct inode
*inode
,
3022 struct file_extent_cluster
*cluster
)
3027 u64 offset
= BTRFS_I(inode
)->index_cnt
;
3032 BUG_ON(cluster
->start
!= cluster
->boundary
[0]);
3033 mutex_lock(&inode
->i_mutex
);
3035 ret
= btrfs_check_data_free_space(inode
, cluster
->end
+
3036 1 - cluster
->start
);
3040 while (nr
< cluster
->nr
) {
3041 start
= cluster
->boundary
[nr
] - offset
;
3042 if (nr
+ 1 < cluster
->nr
)
3043 end
= cluster
->boundary
[nr
+ 1] - 1 - offset
;
3045 end
= cluster
->end
- offset
;
3047 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3048 num_bytes
= end
+ 1 - start
;
3049 ret
= btrfs_prealloc_file_range(inode
, 0, start
,
3050 num_bytes
, num_bytes
,
3051 end
+ 1, &alloc_hint
);
3052 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3057 btrfs_free_reserved_data_space(inode
, cluster
->end
+
3058 1 - cluster
->start
);
3060 mutex_unlock(&inode
->i_mutex
);
3064 static noinline_for_stack
3065 int setup_extent_mapping(struct inode
*inode
, u64 start
, u64 end
,
3068 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
3069 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
3070 struct extent_map
*em
;
3073 em
= alloc_extent_map();
3078 em
->len
= end
+ 1 - start
;
3079 em
->block_len
= em
->len
;
3080 em
->block_start
= block_start
;
3081 em
->bdev
= root
->fs_info
->fs_devices
->latest_bdev
;
3082 set_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
3084 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3086 write_lock(&em_tree
->lock
);
3087 ret
= add_extent_mapping(em_tree
, em
, 0);
3088 write_unlock(&em_tree
->lock
);
3089 if (ret
!= -EEXIST
) {
3090 free_extent_map(em
);
3093 btrfs_drop_extent_cache(inode
, start
, end
, 0);
3095 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3099 static int relocate_file_extent_cluster(struct inode
*inode
,
3100 struct file_extent_cluster
*cluster
)
3104 u64 offset
= BTRFS_I(inode
)->index_cnt
;
3105 unsigned long index
;
3106 unsigned long last_index
;
3108 struct file_ra_state
*ra
;
3109 gfp_t mask
= btrfs_alloc_write_mask(inode
->i_mapping
);
3116 ra
= kzalloc(sizeof(*ra
), GFP_NOFS
);
3120 ret
= prealloc_file_extent_cluster(inode
, cluster
);
3124 file_ra_state_init(ra
, inode
->i_mapping
);
3126 ret
= setup_extent_mapping(inode
, cluster
->start
- offset
,
3127 cluster
->end
- offset
, cluster
->start
);
3131 index
= (cluster
->start
- offset
) >> PAGE_CACHE_SHIFT
;
3132 last_index
= (cluster
->end
- offset
) >> PAGE_CACHE_SHIFT
;
3133 while (index
<= last_index
) {
3134 ret
= btrfs_delalloc_reserve_metadata(inode
, PAGE_CACHE_SIZE
);
3138 page
= find_lock_page(inode
->i_mapping
, index
);
3140 page_cache_sync_readahead(inode
->i_mapping
,
3142 last_index
+ 1 - index
);
3143 page
= find_or_create_page(inode
->i_mapping
, index
,
3146 btrfs_delalloc_release_metadata(inode
,
3153 if (PageReadahead(page
)) {
3154 page_cache_async_readahead(inode
->i_mapping
,
3155 ra
, NULL
, page
, index
,
3156 last_index
+ 1 - index
);
3159 if (!PageUptodate(page
)) {
3160 btrfs_readpage(NULL
, page
);
3162 if (!PageUptodate(page
)) {
3164 page_cache_release(page
);
3165 btrfs_delalloc_release_metadata(inode
,
3172 page_start
= page_offset(page
);
3173 page_end
= page_start
+ PAGE_CACHE_SIZE
- 1;
3175 lock_extent(&BTRFS_I(inode
)->io_tree
, page_start
, page_end
);
3177 set_page_extent_mapped(page
);
3179 if (nr
< cluster
->nr
&&
3180 page_start
+ offset
== cluster
->boundary
[nr
]) {
3181 set_extent_bits(&BTRFS_I(inode
)->io_tree
,
3182 page_start
, page_end
,
3183 EXTENT_BOUNDARY
, GFP_NOFS
);
3187 btrfs_set_extent_delalloc(inode
, page_start
, page_end
, NULL
);
3188 set_page_dirty(page
);
3190 unlock_extent(&BTRFS_I(inode
)->io_tree
,
3191 page_start
, page_end
);
3193 page_cache_release(page
);
3196 balance_dirty_pages_ratelimited(inode
->i_mapping
);
3197 btrfs_throttle(BTRFS_I(inode
)->root
);
3199 WARN_ON(nr
!= cluster
->nr
);
3205 static noinline_for_stack
3206 int relocate_data_extent(struct inode
*inode
, struct btrfs_key
*extent_key
,
3207 struct file_extent_cluster
*cluster
)
3211 if (cluster
->nr
> 0 && extent_key
->objectid
!= cluster
->end
+ 1) {
3212 ret
= relocate_file_extent_cluster(inode
, cluster
);
3219 cluster
->start
= extent_key
->objectid
;
3221 BUG_ON(cluster
->nr
>= MAX_EXTENTS
);
3222 cluster
->end
= extent_key
->objectid
+ extent_key
->offset
- 1;
3223 cluster
->boundary
[cluster
->nr
] = extent_key
->objectid
;
3226 if (cluster
->nr
>= MAX_EXTENTS
) {
3227 ret
= relocate_file_extent_cluster(inode
, cluster
);
3235 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3236 static int get_ref_objectid_v0(struct reloc_control
*rc
,
3237 struct btrfs_path
*path
,
3238 struct btrfs_key
*extent_key
,
3239 u64
*ref_objectid
, int *path_change
)
3241 struct btrfs_key key
;
3242 struct extent_buffer
*leaf
;
3243 struct btrfs_extent_ref_v0
*ref0
;
3247 leaf
= path
->nodes
[0];
3248 slot
= path
->slots
[0];
3250 if (slot
>= btrfs_header_nritems(leaf
)) {
3251 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3255 leaf
= path
->nodes
[0];
3256 slot
= path
->slots
[0];
3260 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
3261 if (key
.objectid
!= extent_key
->objectid
)
3264 if (key
.type
!= BTRFS_EXTENT_REF_V0_KEY
) {
3268 ref0
= btrfs_item_ptr(leaf
, slot
,
3269 struct btrfs_extent_ref_v0
);
3270 *ref_objectid
= btrfs_ref_objectid_v0(leaf
, ref0
);
3278 * helper to add a tree block to the list.
3279 * the major work is getting the generation and level of the block
3281 static int add_tree_block(struct reloc_control
*rc
,
3282 struct btrfs_key
*extent_key
,
3283 struct btrfs_path
*path
,
3284 struct rb_root
*blocks
)
3286 struct extent_buffer
*eb
;
3287 struct btrfs_extent_item
*ei
;
3288 struct btrfs_tree_block_info
*bi
;
3289 struct tree_block
*block
;
3290 struct rb_node
*rb_node
;
3295 eb
= path
->nodes
[0];
3296 item_size
= btrfs_item_size_nr(eb
, path
->slots
[0]);
3298 if (extent_key
->type
== BTRFS_METADATA_ITEM_KEY
||
3299 item_size
>= sizeof(*ei
) + sizeof(*bi
)) {
3300 ei
= btrfs_item_ptr(eb
, path
->slots
[0],
3301 struct btrfs_extent_item
);
3302 if (extent_key
->type
== BTRFS_EXTENT_ITEM_KEY
) {
3303 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
3304 level
= btrfs_tree_block_level(eb
, bi
);
3306 level
= (int)extent_key
->offset
;
3308 generation
= btrfs_extent_generation(eb
, ei
);
3310 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3314 BUG_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
3315 ret
= get_ref_objectid_v0(rc
, path
, extent_key
,
3319 BUG_ON(ref_owner
>= BTRFS_MAX_LEVEL
);
3320 level
= (int)ref_owner
;
3321 /* FIXME: get real generation */
3328 btrfs_release_path(path
);
3330 BUG_ON(level
== -1);
3332 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3336 block
->bytenr
= extent_key
->objectid
;
3337 block
->key
.objectid
= rc
->extent_root
->leafsize
;
3338 block
->key
.offset
= generation
;
3339 block
->level
= level
;
3340 block
->key_ready
= 0;
3342 rb_node
= tree_insert(blocks
, block
->bytenr
, &block
->rb_node
);
3344 backref_tree_panic(rb_node
, -EEXIST
, block
->bytenr
);
3350 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3352 static int __add_tree_block(struct reloc_control
*rc
,
3353 u64 bytenr
, u32 blocksize
,
3354 struct rb_root
*blocks
)
3356 struct btrfs_path
*path
;
3357 struct btrfs_key key
;
3359 bool skinny
= btrfs_fs_incompat(rc
->extent_root
->fs_info
,
3362 if (tree_block_processed(bytenr
, blocksize
, rc
))
3365 if (tree_search(blocks
, bytenr
))
3368 path
= btrfs_alloc_path();
3372 key
.objectid
= bytenr
;
3374 key
.type
= BTRFS_METADATA_ITEM_KEY
;
3375 key
.offset
= (u64
)-1;
3377 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3378 key
.offset
= blocksize
;
3381 path
->search_commit_root
= 1;
3382 path
->skip_locking
= 1;
3383 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
, 0, 0);
3387 if (ret
> 0 && skinny
) {
3388 if (path
->slots
[0]) {
3390 btrfs_item_key_to_cpu(path
->nodes
[0], &key
,
3392 if (key
.objectid
== bytenr
&&
3393 (key
.type
== BTRFS_METADATA_ITEM_KEY
||
3394 (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
3395 key
.offset
== blocksize
)))
3401 btrfs_release_path(path
);
3407 ret
= add_tree_block(rc
, &key
, path
, blocks
);
3409 btrfs_free_path(path
);
3414 * helper to check if the block use full backrefs for pointers in it
3416 static int block_use_full_backref(struct reloc_control
*rc
,
3417 struct extent_buffer
*eb
)
3422 if (btrfs_header_flag(eb
, BTRFS_HEADER_FLAG_RELOC
) ||
3423 btrfs_header_backref_rev(eb
) < BTRFS_MIXED_BACKREF_REV
)
3426 ret
= btrfs_lookup_extent_info(NULL
, rc
->extent_root
,
3427 eb
->start
, btrfs_header_level(eb
), 1,
3431 if (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
)
3438 static int delete_block_group_cache(struct btrfs_fs_info
*fs_info
,
3439 struct inode
*inode
, u64 ino
)
3441 struct btrfs_key key
;
3442 struct btrfs_root
*root
= fs_info
->tree_root
;
3443 struct btrfs_trans_handle
*trans
;
3450 key
.type
= BTRFS_INODE_ITEM_KEY
;
3453 inode
= btrfs_iget(fs_info
->sb
, &key
, root
, NULL
);
3454 if (IS_ERR(inode
) || is_bad_inode(inode
)) {
3461 ret
= btrfs_check_trunc_cache_free_space(root
,
3462 &fs_info
->global_block_rsv
);
3466 trans
= btrfs_join_transaction(root
);
3467 if (IS_ERR(trans
)) {
3468 ret
= PTR_ERR(trans
);
3472 ret
= btrfs_truncate_free_space_cache(root
, trans
, inode
);
3474 btrfs_end_transaction(trans
, root
);
3475 btrfs_btree_balance_dirty(root
);
3482 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3483 * this function scans fs tree to find blocks reference the data extent
3485 static int find_data_references(struct reloc_control
*rc
,
3486 struct btrfs_key
*extent_key
,
3487 struct extent_buffer
*leaf
,
3488 struct btrfs_extent_data_ref
*ref
,
3489 struct rb_root
*blocks
)
3491 struct btrfs_path
*path
;
3492 struct tree_block
*block
;
3493 struct btrfs_root
*root
;
3494 struct btrfs_file_extent_item
*fi
;
3495 struct rb_node
*rb_node
;
3496 struct btrfs_key key
;
3507 ref_root
= btrfs_extent_data_ref_root(leaf
, ref
);
3508 ref_objectid
= btrfs_extent_data_ref_objectid(leaf
, ref
);
3509 ref_offset
= btrfs_extent_data_ref_offset(leaf
, ref
);
3510 ref_count
= btrfs_extent_data_ref_count(leaf
, ref
);
3513 * This is an extent belonging to the free space cache, lets just delete
3514 * it and redo the search.
3516 if (ref_root
== BTRFS_ROOT_TREE_OBJECTID
) {
3517 ret
= delete_block_group_cache(rc
->extent_root
->fs_info
,
3518 NULL
, ref_objectid
);
3524 path
= btrfs_alloc_path();
3529 root
= read_fs_root(rc
->extent_root
->fs_info
, ref_root
);
3531 err
= PTR_ERR(root
);
3535 key
.objectid
= ref_objectid
;
3536 key
.type
= BTRFS_EXTENT_DATA_KEY
;
3537 if (ref_offset
> ((u64
)-1 << 32))
3540 key
.offset
= ref_offset
;
3542 path
->search_commit_root
= 1;
3543 path
->skip_locking
= 1;
3544 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
3550 leaf
= path
->nodes
[0];
3551 nritems
= btrfs_header_nritems(leaf
);
3553 * the references in tree blocks that use full backrefs
3554 * are not counted in
3556 if (block_use_full_backref(rc
, leaf
))
3560 rb_node
= tree_search(blocks
, leaf
->start
);
3565 path
->slots
[0] = nritems
;
3568 while (ref_count
> 0) {
3569 while (path
->slots
[0] >= nritems
) {
3570 ret
= btrfs_next_leaf(root
, path
);
3575 if (WARN_ON(ret
> 0))
3578 leaf
= path
->nodes
[0];
3579 nritems
= btrfs_header_nritems(leaf
);
3582 if (block_use_full_backref(rc
, leaf
))
3586 rb_node
= tree_search(blocks
, leaf
->start
);
3591 path
->slots
[0] = nritems
;
3595 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3596 if (WARN_ON(key
.objectid
!= ref_objectid
||
3597 key
.type
!= BTRFS_EXTENT_DATA_KEY
))
3600 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3601 struct btrfs_file_extent_item
);
3603 if (btrfs_file_extent_type(leaf
, fi
) ==
3604 BTRFS_FILE_EXTENT_INLINE
)
3607 if (btrfs_file_extent_disk_bytenr(leaf
, fi
) !=
3608 extent_key
->objectid
)
3611 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
3612 if (key
.offset
!= ref_offset
)
3620 if (!tree_block_processed(leaf
->start
, leaf
->len
, rc
)) {
3621 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3626 block
->bytenr
= leaf
->start
;
3627 btrfs_item_key_to_cpu(leaf
, &block
->key
, 0);
3629 block
->key_ready
= 1;
3630 rb_node
= tree_insert(blocks
, block
->bytenr
,
3633 backref_tree_panic(rb_node
, -EEXIST
,
3639 path
->slots
[0] = nritems
;
3645 btrfs_free_path(path
);
3650 * helper to find all tree blocks that reference a given data extent
3652 static noinline_for_stack
3653 int add_data_references(struct reloc_control
*rc
,
3654 struct btrfs_key
*extent_key
,
3655 struct btrfs_path
*path
,
3656 struct rb_root
*blocks
)
3658 struct btrfs_key key
;
3659 struct extent_buffer
*eb
;
3660 struct btrfs_extent_data_ref
*dref
;
3661 struct btrfs_extent_inline_ref
*iref
;
3664 u32 blocksize
= btrfs_level_size(rc
->extent_root
, 0);
3668 eb
= path
->nodes
[0];
3669 ptr
= btrfs_item_ptr_offset(eb
, path
->slots
[0]);
3670 end
= ptr
+ btrfs_item_size_nr(eb
, path
->slots
[0]);
3671 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3672 if (ptr
+ sizeof(struct btrfs_extent_item_v0
) == end
)
3676 ptr
+= sizeof(struct btrfs_extent_item
);
3679 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
3680 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
3681 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3682 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
3683 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3685 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3686 dref
= (struct btrfs_extent_data_ref
*)(&iref
->offset
);
3687 ret
= find_data_references(rc
, extent_key
,
3696 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
3702 eb
= path
->nodes
[0];
3703 if (path
->slots
[0] >= btrfs_header_nritems(eb
)) {
3704 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3711 eb
= path
->nodes
[0];
3714 btrfs_item_key_to_cpu(eb
, &key
, path
->slots
[0]);
3715 if (key
.objectid
!= extent_key
->objectid
)
3718 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3719 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
||
3720 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
3722 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
3723 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3725 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3727 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3728 dref
= btrfs_item_ptr(eb
, path
->slots
[0],
3729 struct btrfs_extent_data_ref
);
3730 ret
= find_data_references(rc
, extent_key
,
3742 btrfs_release_path(path
);
3744 free_block_list(blocks
);
3749 * helper to find next unprocessed extent
3751 static noinline_for_stack
3752 int find_next_extent(struct btrfs_trans_handle
*trans
,
3753 struct reloc_control
*rc
, struct btrfs_path
*path
,
3754 struct btrfs_key
*extent_key
)
3756 struct btrfs_key key
;
3757 struct extent_buffer
*leaf
;
3758 u64 start
, end
, last
;
3761 last
= rc
->block_group
->key
.objectid
+ rc
->block_group
->key
.offset
;
3764 if (rc
->search_start
>= last
) {
3769 key
.objectid
= rc
->search_start
;
3770 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3773 path
->search_commit_root
= 1;
3774 path
->skip_locking
= 1;
3775 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
,
3780 leaf
= path
->nodes
[0];
3781 if (path
->slots
[0] >= btrfs_header_nritems(leaf
)) {
3782 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3785 leaf
= path
->nodes
[0];
3788 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3789 if (key
.objectid
>= last
) {
3794 if (key
.type
!= BTRFS_EXTENT_ITEM_KEY
&&
3795 key
.type
!= BTRFS_METADATA_ITEM_KEY
) {
3800 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
3801 key
.objectid
+ key
.offset
<= rc
->search_start
) {
3806 if (key
.type
== BTRFS_METADATA_ITEM_KEY
&&
3807 key
.objectid
+ rc
->extent_root
->leafsize
<=
3813 ret
= find_first_extent_bit(&rc
->processed_blocks
,
3814 key
.objectid
, &start
, &end
,
3815 EXTENT_DIRTY
, NULL
);
3817 if (ret
== 0 && start
<= key
.objectid
) {
3818 btrfs_release_path(path
);
3819 rc
->search_start
= end
+ 1;
3821 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
)
3822 rc
->search_start
= key
.objectid
+ key
.offset
;
3824 rc
->search_start
= key
.objectid
+
3825 rc
->extent_root
->leafsize
;
3826 memcpy(extent_key
, &key
, sizeof(key
));
3830 btrfs_release_path(path
);
3834 static void set_reloc_control(struct reloc_control
*rc
)
3836 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3838 mutex_lock(&fs_info
->reloc_mutex
);
3839 fs_info
->reloc_ctl
= rc
;
3840 mutex_unlock(&fs_info
->reloc_mutex
);
3843 static void unset_reloc_control(struct reloc_control
*rc
)
3845 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3847 mutex_lock(&fs_info
->reloc_mutex
);
3848 fs_info
->reloc_ctl
= NULL
;
3849 mutex_unlock(&fs_info
->reloc_mutex
);
3852 static int check_extent_flags(u64 flags
)
3854 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3855 (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3857 if (!(flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3858 !(flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3860 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3861 (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
))
3866 static noinline_for_stack
3867 int prepare_to_relocate(struct reloc_control
*rc
)
3869 struct btrfs_trans_handle
*trans
;
3872 rc
->block_rsv
= btrfs_alloc_block_rsv(rc
->extent_root
,
3873 BTRFS_BLOCK_RSV_TEMP
);
3878 * reserve some space for creating reloc trees.
3879 * btrfs_init_reloc_root will use them when there
3880 * is no reservation in transaction handle.
3882 ret
= btrfs_block_rsv_add(rc
->extent_root
, rc
->block_rsv
,
3883 rc
->extent_root
->nodesize
* 256,
3884 BTRFS_RESERVE_FLUSH_ALL
);
3888 memset(&rc
->cluster
, 0, sizeof(rc
->cluster
));
3889 rc
->search_start
= rc
->block_group
->key
.objectid
;
3890 rc
->extents_found
= 0;
3891 rc
->nodes_relocated
= 0;
3892 rc
->merging_rsv_size
= 0;
3894 rc
->create_reloc_tree
= 1;
3895 set_reloc_control(rc
);
3897 trans
= btrfs_join_transaction(rc
->extent_root
);
3898 if (IS_ERR(trans
)) {
3899 unset_reloc_control(rc
);
3901 * extent tree is not a ref_cow tree and has no reloc_root to
3902 * cleanup. And callers are responsible to free the above
3905 return PTR_ERR(trans
);
3907 btrfs_commit_transaction(trans
, rc
->extent_root
);
3911 static noinline_for_stack
int relocate_block_group(struct reloc_control
*rc
)
3913 struct rb_root blocks
= RB_ROOT
;
3914 struct btrfs_key key
;
3915 struct btrfs_trans_handle
*trans
= NULL
;
3916 struct btrfs_path
*path
;
3917 struct btrfs_extent_item
*ei
;
3924 path
= btrfs_alloc_path();
3929 ret
= prepare_to_relocate(rc
);
3937 trans
= btrfs_start_transaction(rc
->extent_root
, 0);
3938 if (IS_ERR(trans
)) {
3939 err
= PTR_ERR(trans
);
3944 if (update_backref_cache(trans
, &rc
->backref_cache
)) {
3945 btrfs_end_transaction(trans
, rc
->extent_root
);
3949 ret
= find_next_extent(trans
, rc
, path
, &key
);
3955 rc
->extents_found
++;
3957 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
3958 struct btrfs_extent_item
);
3959 item_size
= btrfs_item_size_nr(path
->nodes
[0], path
->slots
[0]);
3960 if (item_size
>= sizeof(*ei
)) {
3961 flags
= btrfs_extent_flags(path
->nodes
[0], ei
);
3962 ret
= check_extent_flags(flags
);
3966 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3968 int path_change
= 0;
3971 sizeof(struct btrfs_extent_item_v0
));
3972 ret
= get_ref_objectid_v0(rc
, path
, &key
, &ref_owner
,
3974 if (ref_owner
< BTRFS_FIRST_FREE_OBJECTID
)
3975 flags
= BTRFS_EXTENT_FLAG_TREE_BLOCK
;
3977 flags
= BTRFS_EXTENT_FLAG_DATA
;
3980 btrfs_release_path(path
);
3982 path
->search_commit_root
= 1;
3983 path
->skip_locking
= 1;
3984 ret
= btrfs_search_slot(NULL
, rc
->extent_root
,
3997 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
3998 ret
= add_tree_block(rc
, &key
, path
, &blocks
);
3999 } else if (rc
->stage
== UPDATE_DATA_PTRS
&&
4000 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
4001 ret
= add_data_references(rc
, &key
, path
, &blocks
);
4003 btrfs_release_path(path
);
4011 if (!RB_EMPTY_ROOT(&blocks
)) {
4012 ret
= relocate_tree_blocks(trans
, rc
, &blocks
);
4014 if (ret
!= -EAGAIN
) {
4018 rc
->extents_found
--;
4019 rc
->search_start
= key
.objectid
;
4023 if (rc
->commit_transaction
) {
4024 rc
->commit_transaction
= 0;
4025 ret
= btrfs_commit_transaction(trans
, rc
->extent_root
);
4028 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
4029 btrfs_btree_balance_dirty(rc
->extent_root
);
4033 if (rc
->stage
== MOVE_DATA_EXTENTS
&&
4034 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
4035 rc
->found_file_extent
= 1;
4036 ret
= relocate_data_extent(rc
->data_inode
,
4037 &key
, &rc
->cluster
);
4044 if (trans
&& progress
&& err
== -ENOSPC
) {
4045 ret
= btrfs_force_chunk_alloc(trans
, rc
->extent_root
,
4046 rc
->block_group
->flags
);
4054 btrfs_release_path(path
);
4055 clear_extent_bits(&rc
->processed_blocks
, 0, (u64
)-1, EXTENT_DIRTY
,
4059 btrfs_end_transaction_throttle(trans
, rc
->extent_root
);
4060 btrfs_btree_balance_dirty(rc
->extent_root
);
4064 ret
= relocate_file_extent_cluster(rc
->data_inode
,
4070 rc
->create_reloc_tree
= 0;
4071 set_reloc_control(rc
);
4073 backref_cache_cleanup(&rc
->backref_cache
);
4074 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
4076 err
= prepare_to_merge(rc
, err
);
4078 merge_reloc_roots(rc
);
4080 rc
->merge_reloc_tree
= 0;
4081 unset_reloc_control(rc
);
4082 btrfs_block_rsv_release(rc
->extent_root
, rc
->block_rsv
, (u64
)-1);
4084 /* get rid of pinned extents */
4085 trans
= btrfs_join_transaction(rc
->extent_root
);
4087 err
= PTR_ERR(trans
);
4089 btrfs_commit_transaction(trans
, rc
->extent_root
);
4091 btrfs_free_block_rsv(rc
->extent_root
, rc
->block_rsv
);
4092 btrfs_free_path(path
);
4096 static int __insert_orphan_inode(struct btrfs_trans_handle
*trans
,
4097 struct btrfs_root
*root
, u64 objectid
)
4099 struct btrfs_path
*path
;
4100 struct btrfs_inode_item
*item
;
4101 struct extent_buffer
*leaf
;
4104 path
= btrfs_alloc_path();
4108 ret
= btrfs_insert_empty_inode(trans
, root
, path
, objectid
);
4112 leaf
= path
->nodes
[0];
4113 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_inode_item
);
4114 memset_extent_buffer(leaf
, 0, (unsigned long)item
, sizeof(*item
));
4115 btrfs_set_inode_generation(leaf
, item
, 1);
4116 btrfs_set_inode_size(leaf
, item
, 0);
4117 btrfs_set_inode_mode(leaf
, item
, S_IFREG
| 0600);
4118 btrfs_set_inode_flags(leaf
, item
, BTRFS_INODE_NOCOMPRESS
|
4119 BTRFS_INODE_PREALLOC
);
4120 btrfs_mark_buffer_dirty(leaf
);
4121 btrfs_release_path(path
);
4123 btrfs_free_path(path
);
4128 * helper to create inode for data relocation.
4129 * the inode is in data relocation tree and its link count is 0
4131 static noinline_for_stack
4132 struct inode
*create_reloc_inode(struct btrfs_fs_info
*fs_info
,
4133 struct btrfs_block_group_cache
*group
)
4135 struct inode
*inode
= NULL
;
4136 struct btrfs_trans_handle
*trans
;
4137 struct btrfs_root
*root
;
4138 struct btrfs_key key
;
4139 u64 objectid
= BTRFS_FIRST_FREE_OBJECTID
;
4142 root
= read_fs_root(fs_info
, BTRFS_DATA_RELOC_TREE_OBJECTID
);
4144 return ERR_CAST(root
);
4146 trans
= btrfs_start_transaction(root
, 6);
4148 return ERR_CAST(trans
);
4150 err
= btrfs_find_free_objectid(root
, &objectid
);
4154 err
= __insert_orphan_inode(trans
, root
, objectid
);
4157 key
.objectid
= objectid
;
4158 key
.type
= BTRFS_INODE_ITEM_KEY
;
4160 inode
= btrfs_iget(root
->fs_info
->sb
, &key
, root
, NULL
);
4161 BUG_ON(IS_ERR(inode
) || is_bad_inode(inode
));
4162 BTRFS_I(inode
)->index_cnt
= group
->key
.objectid
;
4164 err
= btrfs_orphan_add(trans
, inode
);
4166 btrfs_end_transaction(trans
, root
);
4167 btrfs_btree_balance_dirty(root
);
4171 inode
= ERR_PTR(err
);
4176 static struct reloc_control
*alloc_reloc_control(struct btrfs_fs_info
*fs_info
)
4178 struct reloc_control
*rc
;
4180 rc
= kzalloc(sizeof(*rc
), GFP_NOFS
);
4184 INIT_LIST_HEAD(&rc
->reloc_roots
);
4185 backref_cache_init(&rc
->backref_cache
);
4186 mapping_tree_init(&rc
->reloc_root_tree
);
4187 extent_io_tree_init(&rc
->processed_blocks
,
4188 fs_info
->btree_inode
->i_mapping
);
4193 * function to relocate all extents in a block group.
4195 int btrfs_relocate_block_group(struct btrfs_root
*extent_root
, u64 group_start
)
4197 struct btrfs_fs_info
*fs_info
= extent_root
->fs_info
;
4198 struct reloc_control
*rc
;
4199 struct inode
*inode
;
4200 struct btrfs_path
*path
;
4205 rc
= alloc_reloc_control(fs_info
);
4209 rc
->extent_root
= extent_root
;
4211 rc
->block_group
= btrfs_lookup_block_group(fs_info
, group_start
);
4212 BUG_ON(!rc
->block_group
);
4214 if (!rc
->block_group
->ro
) {
4215 ret
= btrfs_set_block_group_ro(extent_root
, rc
->block_group
);
4223 path
= btrfs_alloc_path();
4229 inode
= lookup_free_space_inode(fs_info
->tree_root
, rc
->block_group
,
4231 btrfs_free_path(path
);
4234 ret
= delete_block_group_cache(fs_info
, inode
, 0);
4236 ret
= PTR_ERR(inode
);
4238 if (ret
&& ret
!= -ENOENT
) {
4243 rc
->data_inode
= create_reloc_inode(fs_info
, rc
->block_group
);
4244 if (IS_ERR(rc
->data_inode
)) {
4245 err
= PTR_ERR(rc
->data_inode
);
4246 rc
->data_inode
= NULL
;
4250 printk(KERN_INFO
"btrfs: relocating block group %llu flags %llu\n",
4251 rc
->block_group
->key
.objectid
, rc
->block_group
->flags
);
4253 ret
= btrfs_start_delalloc_roots(fs_info
, 0);
4258 btrfs_wait_ordered_roots(fs_info
, -1);
4261 mutex_lock(&fs_info
->cleaner_mutex
);
4262 ret
= relocate_block_group(rc
);
4263 mutex_unlock(&fs_info
->cleaner_mutex
);
4269 if (rc
->extents_found
== 0)
4272 printk(KERN_INFO
"btrfs: found %llu extents\n",
4275 if (rc
->stage
== MOVE_DATA_EXTENTS
&& rc
->found_file_extent
) {
4276 ret
= btrfs_wait_ordered_range(rc
->data_inode
, 0,
4282 invalidate_mapping_pages(rc
->data_inode
->i_mapping
,
4284 rc
->stage
= UPDATE_DATA_PTRS
;
4288 filemap_write_and_wait_range(fs_info
->btree_inode
->i_mapping
,
4289 rc
->block_group
->key
.objectid
,
4290 rc
->block_group
->key
.objectid
+
4291 rc
->block_group
->key
.offset
- 1);
4293 WARN_ON(rc
->block_group
->pinned
> 0);
4294 WARN_ON(rc
->block_group
->reserved
> 0);
4295 WARN_ON(btrfs_block_group_used(&rc
->block_group
->item
) > 0);
4298 btrfs_set_block_group_rw(extent_root
, rc
->block_group
);
4299 iput(rc
->data_inode
);
4300 btrfs_put_block_group(rc
->block_group
);
4305 static noinline_for_stack
int mark_garbage_root(struct btrfs_root
*root
)
4307 struct btrfs_trans_handle
*trans
;
4310 trans
= btrfs_start_transaction(root
->fs_info
->tree_root
, 0);
4312 return PTR_ERR(trans
);
4314 memset(&root
->root_item
.drop_progress
, 0,
4315 sizeof(root
->root_item
.drop_progress
));
4316 root
->root_item
.drop_level
= 0;
4317 btrfs_set_root_refs(&root
->root_item
, 0);
4318 ret
= btrfs_update_root(trans
, root
->fs_info
->tree_root
,
4319 &root
->root_key
, &root
->root_item
);
4321 err
= btrfs_end_transaction(trans
, root
->fs_info
->tree_root
);
4328 * recover relocation interrupted by system crash.
4330 * this function resumes merging reloc trees with corresponding fs trees.
4331 * this is important for keeping the sharing of tree blocks
4333 int btrfs_recover_relocation(struct btrfs_root
*root
)
4335 LIST_HEAD(reloc_roots
);
4336 struct btrfs_key key
;
4337 struct btrfs_root
*fs_root
;
4338 struct btrfs_root
*reloc_root
;
4339 struct btrfs_path
*path
;
4340 struct extent_buffer
*leaf
;
4341 struct reloc_control
*rc
= NULL
;
4342 struct btrfs_trans_handle
*trans
;
4346 path
= btrfs_alloc_path();
4351 key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
4352 key
.type
= BTRFS_ROOT_ITEM_KEY
;
4353 key
.offset
= (u64
)-1;
4356 ret
= btrfs_search_slot(NULL
, root
->fs_info
->tree_root
, &key
,
4363 if (path
->slots
[0] == 0)
4367 leaf
= path
->nodes
[0];
4368 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
4369 btrfs_release_path(path
);
4371 if (key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
||
4372 key
.type
!= BTRFS_ROOT_ITEM_KEY
)
4375 reloc_root
= btrfs_read_fs_root(root
, &key
);
4376 if (IS_ERR(reloc_root
)) {
4377 err
= PTR_ERR(reloc_root
);
4381 list_add(&reloc_root
->root_list
, &reloc_roots
);
4383 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
4384 fs_root
= read_fs_root(root
->fs_info
,
4385 reloc_root
->root_key
.offset
);
4386 if (IS_ERR(fs_root
)) {
4387 ret
= PTR_ERR(fs_root
);
4388 if (ret
!= -ENOENT
) {
4392 ret
= mark_garbage_root(reloc_root
);
4400 if (key
.offset
== 0)
4405 btrfs_release_path(path
);
4407 if (list_empty(&reloc_roots
))
4410 rc
= alloc_reloc_control(root
->fs_info
);
4416 rc
->extent_root
= root
->fs_info
->extent_root
;
4418 set_reloc_control(rc
);
4420 trans
= btrfs_join_transaction(rc
->extent_root
);
4421 if (IS_ERR(trans
)) {
4422 unset_reloc_control(rc
);
4423 err
= PTR_ERR(trans
);
4427 rc
->merge_reloc_tree
= 1;
4429 while (!list_empty(&reloc_roots
)) {
4430 reloc_root
= list_entry(reloc_roots
.next
,
4431 struct btrfs_root
, root_list
);
4432 list_del(&reloc_root
->root_list
);
4434 if (btrfs_root_refs(&reloc_root
->root_item
) == 0) {
4435 list_add_tail(&reloc_root
->root_list
,
4440 fs_root
= read_fs_root(root
->fs_info
,
4441 reloc_root
->root_key
.offset
);
4442 if (IS_ERR(fs_root
)) {
4443 err
= PTR_ERR(fs_root
);
4447 err
= __add_reloc_root(reloc_root
);
4448 BUG_ON(err
< 0); /* -ENOMEM or logic error */
4449 fs_root
->reloc_root
= reloc_root
;
4452 err
= btrfs_commit_transaction(trans
, rc
->extent_root
);
4456 merge_reloc_roots(rc
);
4458 unset_reloc_control(rc
);
4460 trans
= btrfs_join_transaction(rc
->extent_root
);
4462 err
= PTR_ERR(trans
);
4464 err
= btrfs_commit_transaction(trans
, rc
->extent_root
);
4468 if (!list_empty(&reloc_roots
))
4469 free_reloc_roots(&reloc_roots
);
4471 btrfs_free_path(path
);
4474 /* cleanup orphan inode in data relocation tree */
4475 fs_root
= read_fs_root(root
->fs_info
,
4476 BTRFS_DATA_RELOC_TREE_OBJECTID
);
4477 if (IS_ERR(fs_root
))
4478 err
= PTR_ERR(fs_root
);
4480 err
= btrfs_orphan_cleanup(fs_root
);
4486 * helper to add ordered checksum for data relocation.
4488 * cloning checksum properly handles the nodatasum extents.
4489 * it also saves CPU time to re-calculate the checksum.
4491 int btrfs_reloc_clone_csums(struct inode
*inode
, u64 file_pos
, u64 len
)
4493 struct btrfs_ordered_sum
*sums
;
4494 struct btrfs_ordered_extent
*ordered
;
4495 struct btrfs_root
*root
= BTRFS_I(inode
)->root
;
4501 ordered
= btrfs_lookup_ordered_extent(inode
, file_pos
);
4502 BUG_ON(ordered
->file_offset
!= file_pos
|| ordered
->len
!= len
);
4504 disk_bytenr
= file_pos
+ BTRFS_I(inode
)->index_cnt
;
4505 ret
= btrfs_lookup_csums_range(root
->fs_info
->csum_root
, disk_bytenr
,
4506 disk_bytenr
+ len
- 1, &list
, 0);
4510 while (!list_empty(&list
)) {
4511 sums
= list_entry(list
.next
, struct btrfs_ordered_sum
, list
);
4512 list_del_init(&sums
->list
);
4515 * We need to offset the new_bytenr based on where the csum is.
4516 * We need to do this because we will read in entire prealloc
4517 * extents but we may have written to say the middle of the
4518 * prealloc extent, so we need to make sure the csum goes with
4519 * the right disk offset.
4521 * We can do this because the data reloc inode refers strictly
4522 * to the on disk bytes, so we don't have to worry about
4523 * disk_len vs real len like with real inodes since it's all
4526 new_bytenr
= ordered
->start
+ (sums
->bytenr
- disk_bytenr
);
4527 sums
->bytenr
= new_bytenr
;
4529 btrfs_add_ordered_sum(inode
, ordered
, sums
);
4532 btrfs_put_ordered_extent(ordered
);
4536 int btrfs_reloc_cow_block(struct btrfs_trans_handle
*trans
,
4537 struct btrfs_root
*root
, struct extent_buffer
*buf
,
4538 struct extent_buffer
*cow
)
4540 struct reloc_control
*rc
;
4541 struct backref_node
*node
;
4546 rc
= root
->fs_info
->reloc_ctl
;
4550 BUG_ON(rc
->stage
== UPDATE_DATA_PTRS
&&
4551 root
->root_key
.objectid
== BTRFS_DATA_RELOC_TREE_OBJECTID
);
4553 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
4554 if (buf
== root
->node
)
4555 __update_reloc_root(root
, cow
->start
);
4558 level
= btrfs_header_level(buf
);
4559 if (btrfs_header_generation(buf
) <=
4560 btrfs_root_last_snapshot(&root
->root_item
))
4563 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
&&
4564 rc
->create_reloc_tree
) {
4565 WARN_ON(!first_cow
&& level
== 0);
4567 node
= rc
->backref_cache
.path
[level
];
4568 BUG_ON(node
->bytenr
!= buf
->start
&&
4569 node
->new_bytenr
!= buf
->start
);
4571 drop_node_buffer(node
);
4572 extent_buffer_get(cow
);
4574 node
->new_bytenr
= cow
->start
;
4576 if (!node
->pending
) {
4577 list_move_tail(&node
->list
,
4578 &rc
->backref_cache
.pending
[level
]);
4583 __mark_block_processed(rc
, node
);
4585 if (first_cow
&& level
> 0)
4586 rc
->nodes_relocated
+= buf
->len
;
4589 if (level
== 0 && first_cow
&& rc
->stage
== UPDATE_DATA_PTRS
)
4590 ret
= replace_file_extents(trans
, rc
, root
, cow
);
4595 * called before creating snapshot. it calculates metadata reservation
4596 * requried for relocating tree blocks in the snapshot
4598 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle
*trans
,
4599 struct btrfs_pending_snapshot
*pending
,
4600 u64
*bytes_to_reserve
)
4602 struct btrfs_root
*root
;
4603 struct reloc_control
*rc
;
4605 root
= pending
->root
;
4606 if (!root
->reloc_root
)
4609 rc
= root
->fs_info
->reloc_ctl
;
4610 if (!rc
->merge_reloc_tree
)
4613 root
= root
->reloc_root
;
4614 BUG_ON(btrfs_root_refs(&root
->root_item
) == 0);
4616 * relocation is in the stage of merging trees. the space
4617 * used by merging a reloc tree is twice the size of
4618 * relocated tree nodes in the worst case. half for cowing
4619 * the reloc tree, half for cowing the fs tree. the space
4620 * used by cowing the reloc tree will be freed after the
4621 * tree is dropped. if we create snapshot, cowing the fs
4622 * tree may use more space than it frees. so we need
4623 * reserve extra space.
4625 *bytes_to_reserve
+= rc
->nodes_relocated
;
4629 * called after snapshot is created. migrate block reservation
4630 * and create reloc root for the newly created snapshot
4632 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle
*trans
,
4633 struct btrfs_pending_snapshot
*pending
)
4635 struct btrfs_root
*root
= pending
->root
;
4636 struct btrfs_root
*reloc_root
;
4637 struct btrfs_root
*new_root
;
4638 struct reloc_control
*rc
;
4641 if (!root
->reloc_root
)
4644 rc
= root
->fs_info
->reloc_ctl
;
4645 rc
->merging_rsv_size
+= rc
->nodes_relocated
;
4647 if (rc
->merge_reloc_tree
) {
4648 ret
= btrfs_block_rsv_migrate(&pending
->block_rsv
,
4650 rc
->nodes_relocated
);
4655 new_root
= pending
->snap
;
4656 reloc_root
= create_reloc_root(trans
, root
->reloc_root
,
4657 new_root
->root_key
.objectid
);
4658 if (IS_ERR(reloc_root
))
4659 return PTR_ERR(reloc_root
);
4661 ret
= __add_reloc_root(reloc_root
);
4663 new_root
->reloc_root
= reloc_root
;
4665 if (rc
->create_reloc_tree
)
4666 ret
= clone_backref_node(trans
, rc
, root
, reloc_root
);