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"
37 * backref_node, mapping_node and tree_block start with this
40 struct rb_node rb_node
;
45 * present a tree block in the backref cache
48 struct rb_node rb_node
;
52 /* objectid of tree block owner, can be not uptodate */
54 /* link to pending, changed or detached list */
55 struct list_head list
;
56 /* list of upper level blocks reference this block */
57 struct list_head upper
;
58 /* list of child blocks in the cache */
59 struct list_head lower
;
60 /* NULL if this node is not tree root */
61 struct btrfs_root
*root
;
62 /* extent buffer got by COW the block */
63 struct extent_buffer
*eb
;
64 /* level of tree block */
66 /* is the block in non-reference counted tree */
67 unsigned int cowonly
:1;
68 /* 1 if no child node in the cache */
69 unsigned int lowest
:1;
70 /* is the extent buffer locked */
71 unsigned int locked
:1;
72 /* has the block been processed */
73 unsigned int processed
:1;
74 /* have backrefs of this block been checked */
75 unsigned int checked
:1;
77 * 1 if corresponding block has been cowed but some upper
78 * level block pointers may not point to the new location
80 unsigned int pending
:1;
82 * 1 if the backref node isn't connected to any other
85 unsigned int detached
:1;
89 * present a block pointer in the backref cache
92 struct list_head list
[2];
93 struct backref_node
*node
[2];
98 #define RELOCATION_RESERVED_NODES 256
100 struct backref_cache
{
101 /* red black tree of all backref nodes in the cache */
102 struct rb_root rb_root
;
103 /* for passing backref nodes to btrfs_reloc_cow_block */
104 struct backref_node
*path
[BTRFS_MAX_LEVEL
];
106 * list of blocks that have been cowed but some block
107 * pointers in upper level blocks may not reflect the
110 struct list_head pending
[BTRFS_MAX_LEVEL
];
111 /* list of backref nodes with no child node */
112 struct list_head leaves
;
113 /* list of blocks that have been cowed in current transaction */
114 struct list_head changed
;
115 /* list of detached backref node. */
116 struct list_head detached
;
125 * map address of tree root to tree
127 struct mapping_node
{
128 struct rb_node rb_node
;
133 struct mapping_tree
{
134 struct rb_root rb_root
;
139 * present a tree block to process
142 struct rb_node rb_node
;
144 struct btrfs_key key
;
145 unsigned int level
:8;
146 unsigned int key_ready
:1;
149 #define MAX_EXTENTS 128
151 struct file_extent_cluster
{
154 u64 boundary
[MAX_EXTENTS
];
158 struct reloc_control
{
159 /* block group to relocate */
160 struct btrfs_block_group_cache
*block_group
;
162 struct btrfs_root
*extent_root
;
163 /* inode for moving data */
164 struct inode
*data_inode
;
166 struct btrfs_block_rsv
*block_rsv
;
168 struct backref_cache backref_cache
;
170 struct file_extent_cluster cluster
;
171 /* tree blocks have been processed */
172 struct extent_io_tree processed_blocks
;
173 /* map start of tree root to corresponding reloc tree */
174 struct mapping_tree reloc_root_tree
;
175 /* list of reloc trees */
176 struct list_head reloc_roots
;
177 /* size of metadata reservation for merging reloc trees */
178 u64 merging_rsv_size
;
179 /* size of relocated tree nodes */
181 /* reserved size for block group relocation*/
187 unsigned int stage
:8;
188 unsigned int create_reloc_tree
:1;
189 unsigned int merge_reloc_tree
:1;
190 unsigned int found_file_extent
:1;
193 /* stages of data relocation */
194 #define MOVE_DATA_EXTENTS 0
195 #define UPDATE_DATA_PTRS 1
197 static void remove_backref_node(struct backref_cache
*cache
,
198 struct backref_node
*node
);
199 static void __mark_block_processed(struct reloc_control
*rc
,
200 struct backref_node
*node
);
202 static void mapping_tree_init(struct mapping_tree
*tree
)
204 tree
->rb_root
= RB_ROOT
;
205 spin_lock_init(&tree
->lock
);
208 static void backref_cache_init(struct backref_cache
*cache
)
211 cache
->rb_root
= RB_ROOT
;
212 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++)
213 INIT_LIST_HEAD(&cache
->pending
[i
]);
214 INIT_LIST_HEAD(&cache
->changed
);
215 INIT_LIST_HEAD(&cache
->detached
);
216 INIT_LIST_HEAD(&cache
->leaves
);
219 static void backref_cache_cleanup(struct backref_cache
*cache
)
221 struct backref_node
*node
;
224 while (!list_empty(&cache
->detached
)) {
225 node
= list_entry(cache
->detached
.next
,
226 struct backref_node
, list
);
227 remove_backref_node(cache
, node
);
230 while (!list_empty(&cache
->leaves
)) {
231 node
= list_entry(cache
->leaves
.next
,
232 struct backref_node
, lower
);
233 remove_backref_node(cache
, node
);
236 cache
->last_trans
= 0;
238 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++)
239 ASSERT(list_empty(&cache
->pending
[i
]));
240 ASSERT(list_empty(&cache
->changed
));
241 ASSERT(list_empty(&cache
->detached
));
242 ASSERT(RB_EMPTY_ROOT(&cache
->rb_root
));
243 ASSERT(!cache
->nr_nodes
);
244 ASSERT(!cache
->nr_edges
);
247 static struct backref_node
*alloc_backref_node(struct backref_cache
*cache
)
249 struct backref_node
*node
;
251 node
= kzalloc(sizeof(*node
), GFP_NOFS
);
253 INIT_LIST_HEAD(&node
->list
);
254 INIT_LIST_HEAD(&node
->upper
);
255 INIT_LIST_HEAD(&node
->lower
);
256 RB_CLEAR_NODE(&node
->rb_node
);
262 static void free_backref_node(struct backref_cache
*cache
,
263 struct backref_node
*node
)
271 static struct backref_edge
*alloc_backref_edge(struct backref_cache
*cache
)
273 struct backref_edge
*edge
;
275 edge
= kzalloc(sizeof(*edge
), GFP_NOFS
);
281 static void free_backref_edge(struct backref_cache
*cache
,
282 struct backref_edge
*edge
)
290 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 bytenr
,
291 struct rb_node
*node
)
293 struct rb_node
**p
= &root
->rb_node
;
294 struct rb_node
*parent
= NULL
;
295 struct tree_entry
*entry
;
299 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
301 if (bytenr
< entry
->bytenr
)
303 else if (bytenr
> entry
->bytenr
)
309 rb_link_node(node
, parent
, p
);
310 rb_insert_color(node
, root
);
314 static struct rb_node
*tree_search(struct rb_root
*root
, u64 bytenr
)
316 struct rb_node
*n
= root
->rb_node
;
317 struct tree_entry
*entry
;
320 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
322 if (bytenr
< entry
->bytenr
)
324 else if (bytenr
> entry
->bytenr
)
332 static void backref_tree_panic(struct rb_node
*rb_node
, int errno
, u64 bytenr
)
335 struct btrfs_fs_info
*fs_info
= NULL
;
336 struct backref_node
*bnode
= rb_entry(rb_node
, struct backref_node
,
339 fs_info
= bnode
->root
->fs_info
;
340 btrfs_panic(fs_info
, errno
,
341 "Inconsistency in backref cache found at offset %llu",
346 * walk up backref nodes until reach node presents tree root
348 static struct backref_node
*walk_up_backref(struct backref_node
*node
,
349 struct backref_edge
*edges
[],
352 struct backref_edge
*edge
;
355 while (!list_empty(&node
->upper
)) {
356 edge
= list_entry(node
->upper
.next
,
357 struct backref_edge
, list
[LOWER
]);
359 node
= edge
->node
[UPPER
];
361 BUG_ON(node
->detached
);
367 * walk down backref nodes to find start of next reference path
369 static struct backref_node
*walk_down_backref(struct backref_edge
*edges
[],
372 struct backref_edge
*edge
;
373 struct backref_node
*lower
;
377 edge
= edges
[idx
- 1];
378 lower
= edge
->node
[LOWER
];
379 if (list_is_last(&edge
->list
[LOWER
], &lower
->upper
)) {
383 edge
= list_entry(edge
->list
[LOWER
].next
,
384 struct backref_edge
, list
[LOWER
]);
385 edges
[idx
- 1] = edge
;
387 return edge
->node
[UPPER
];
393 static void unlock_node_buffer(struct backref_node
*node
)
396 btrfs_tree_unlock(node
->eb
);
401 static void drop_node_buffer(struct backref_node
*node
)
404 unlock_node_buffer(node
);
405 free_extent_buffer(node
->eb
);
410 static void drop_backref_node(struct backref_cache
*tree
,
411 struct backref_node
*node
)
413 BUG_ON(!list_empty(&node
->upper
));
415 drop_node_buffer(node
);
416 list_del(&node
->list
);
417 list_del(&node
->lower
);
418 if (!RB_EMPTY_NODE(&node
->rb_node
))
419 rb_erase(&node
->rb_node
, &tree
->rb_root
);
420 free_backref_node(tree
, node
);
424 * remove a backref node from the backref cache
426 static void remove_backref_node(struct backref_cache
*cache
,
427 struct backref_node
*node
)
429 struct backref_node
*upper
;
430 struct backref_edge
*edge
;
435 BUG_ON(!node
->lowest
&& !node
->detached
);
436 while (!list_empty(&node
->upper
)) {
437 edge
= list_entry(node
->upper
.next
, struct backref_edge
,
439 upper
= edge
->node
[UPPER
];
440 list_del(&edge
->list
[LOWER
]);
441 list_del(&edge
->list
[UPPER
]);
442 free_backref_edge(cache
, edge
);
444 if (RB_EMPTY_NODE(&upper
->rb_node
)) {
445 BUG_ON(!list_empty(&node
->upper
));
446 drop_backref_node(cache
, node
);
452 * add the node to leaf node list if no other
453 * child block cached.
455 if (list_empty(&upper
->lower
)) {
456 list_add_tail(&upper
->lower
, &cache
->leaves
);
461 drop_backref_node(cache
, node
);
464 static void update_backref_node(struct backref_cache
*cache
,
465 struct backref_node
*node
, u64 bytenr
)
467 struct rb_node
*rb_node
;
468 rb_erase(&node
->rb_node
, &cache
->rb_root
);
469 node
->bytenr
= bytenr
;
470 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
, &node
->rb_node
);
472 backref_tree_panic(rb_node
, -EEXIST
, bytenr
);
476 * update backref cache after a transaction commit
478 static int update_backref_cache(struct btrfs_trans_handle
*trans
,
479 struct backref_cache
*cache
)
481 struct backref_node
*node
;
484 if (cache
->last_trans
== 0) {
485 cache
->last_trans
= trans
->transid
;
489 if (cache
->last_trans
== trans
->transid
)
493 * detached nodes are used to avoid unnecessary backref
494 * lookup. transaction commit changes the extent tree.
495 * so the detached nodes are no longer useful.
497 while (!list_empty(&cache
->detached
)) {
498 node
= list_entry(cache
->detached
.next
,
499 struct backref_node
, list
);
500 remove_backref_node(cache
, node
);
503 while (!list_empty(&cache
->changed
)) {
504 node
= list_entry(cache
->changed
.next
,
505 struct backref_node
, list
);
506 list_del_init(&node
->list
);
507 BUG_ON(node
->pending
);
508 update_backref_node(cache
, node
, node
->new_bytenr
);
512 * some nodes can be left in the pending list if there were
513 * errors during processing the pending nodes.
515 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
516 list_for_each_entry(node
, &cache
->pending
[level
], list
) {
517 BUG_ON(!node
->pending
);
518 if (node
->bytenr
== node
->new_bytenr
)
520 update_backref_node(cache
, node
, node
->new_bytenr
);
524 cache
->last_trans
= 0;
529 static int should_ignore_root(struct btrfs_root
*root
)
531 struct btrfs_root
*reloc_root
;
533 if (!test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
))
536 reloc_root
= root
->reloc_root
;
540 if (btrfs_root_last_snapshot(&reloc_root
->root_item
) ==
541 root
->fs_info
->running_transaction
->transid
- 1)
544 * if there is reloc tree and it was created in previous
545 * transaction backref lookup can find the reloc tree,
546 * so backref node for the fs tree root is useless for
552 * find reloc tree by address of tree root
554 static struct btrfs_root
*find_reloc_root(struct reloc_control
*rc
,
557 struct rb_node
*rb_node
;
558 struct mapping_node
*node
;
559 struct btrfs_root
*root
= NULL
;
561 spin_lock(&rc
->reloc_root_tree
.lock
);
562 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
, bytenr
);
564 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
565 root
= (struct btrfs_root
*)node
->data
;
567 spin_unlock(&rc
->reloc_root_tree
.lock
);
571 static int is_cowonly_root(u64 root_objectid
)
573 if (root_objectid
== BTRFS_ROOT_TREE_OBJECTID
||
574 root_objectid
== BTRFS_EXTENT_TREE_OBJECTID
||
575 root_objectid
== BTRFS_CHUNK_TREE_OBJECTID
||
576 root_objectid
== BTRFS_DEV_TREE_OBJECTID
||
577 root_objectid
== BTRFS_TREE_LOG_OBJECTID
||
578 root_objectid
== BTRFS_CSUM_TREE_OBJECTID
||
579 root_objectid
== BTRFS_UUID_TREE_OBJECTID
||
580 root_objectid
== BTRFS_QUOTA_TREE_OBJECTID
||
581 root_objectid
== BTRFS_FREE_SPACE_TREE_OBJECTID
)
586 static struct btrfs_root
*read_fs_root(struct btrfs_fs_info
*fs_info
,
589 struct btrfs_key key
;
591 key
.objectid
= root_objectid
;
592 key
.type
= BTRFS_ROOT_ITEM_KEY
;
593 if (is_cowonly_root(root_objectid
))
596 key
.offset
= (u64
)-1;
598 return btrfs_get_fs_root(fs_info
, &key
, false);
601 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
602 static noinline_for_stack
603 struct btrfs_root
*find_tree_root(struct reloc_control
*rc
,
604 struct extent_buffer
*leaf
,
605 struct btrfs_extent_ref_v0
*ref0
)
607 struct btrfs_root
*root
;
608 u64 root_objectid
= btrfs_ref_root_v0(leaf
, ref0
);
609 u64 generation
= btrfs_ref_generation_v0(leaf
, ref0
);
611 BUG_ON(root_objectid
== BTRFS_TREE_RELOC_OBJECTID
);
613 root
= read_fs_root(rc
->extent_root
->fs_info
, root_objectid
);
614 BUG_ON(IS_ERR(root
));
616 if (test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
) &&
617 generation
!= btrfs_root_generation(&root
->root_item
))
624 static noinline_for_stack
625 int find_inline_backref(struct extent_buffer
*leaf
, int slot
,
626 unsigned long *ptr
, unsigned long *end
)
628 struct btrfs_key key
;
629 struct btrfs_extent_item
*ei
;
630 struct btrfs_tree_block_info
*bi
;
633 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
635 item_size
= btrfs_item_size_nr(leaf
, slot
);
636 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
637 if (item_size
< sizeof(*ei
)) {
638 WARN_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
642 ei
= btrfs_item_ptr(leaf
, slot
, struct btrfs_extent_item
);
643 WARN_ON(!(btrfs_extent_flags(leaf
, ei
) &
644 BTRFS_EXTENT_FLAG_TREE_BLOCK
));
646 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
647 item_size
<= sizeof(*ei
) + sizeof(*bi
)) {
648 WARN_ON(item_size
< sizeof(*ei
) + sizeof(*bi
));
651 if (key
.type
== BTRFS_METADATA_ITEM_KEY
&&
652 item_size
<= sizeof(*ei
)) {
653 WARN_ON(item_size
< sizeof(*ei
));
657 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
) {
658 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
659 *ptr
= (unsigned long)(bi
+ 1);
661 *ptr
= (unsigned long)(ei
+ 1);
663 *end
= (unsigned long)ei
+ item_size
;
668 * build backref tree for a given tree block. root of the backref tree
669 * corresponds the tree block, leaves of the backref tree correspond
670 * roots of b-trees that reference the tree block.
672 * the basic idea of this function is check backrefs of a given block
673 * to find upper level blocks that reference the block, and then check
674 * backrefs of these upper level blocks recursively. the recursion stop
675 * when tree root is reached or backrefs for the block is cached.
677 * NOTE: if we find backrefs for a block are cached, we know backrefs
678 * for all upper level blocks that directly/indirectly reference the
679 * block are also cached.
681 static noinline_for_stack
682 struct backref_node
*build_backref_tree(struct reloc_control
*rc
,
683 struct btrfs_key
*node_key
,
684 int level
, u64 bytenr
)
686 struct backref_cache
*cache
= &rc
->backref_cache
;
687 struct btrfs_path
*path1
;
688 struct btrfs_path
*path2
;
689 struct extent_buffer
*eb
;
690 struct btrfs_root
*root
;
691 struct backref_node
*cur
;
692 struct backref_node
*upper
;
693 struct backref_node
*lower
;
694 struct backref_node
*node
= NULL
;
695 struct backref_node
*exist
= NULL
;
696 struct backref_edge
*edge
;
697 struct rb_node
*rb_node
;
698 struct btrfs_key key
;
706 bool need_check
= true;
708 path1
= btrfs_alloc_path();
709 path2
= btrfs_alloc_path();
710 if (!path1
|| !path2
) {
714 path1
->reada
= READA_FORWARD
;
715 path2
->reada
= READA_FORWARD
;
717 node
= alloc_backref_node(cache
);
723 node
->bytenr
= bytenr
;
730 key
.objectid
= cur
->bytenr
;
731 key
.type
= BTRFS_METADATA_ITEM_KEY
;
732 key
.offset
= (u64
)-1;
734 path1
->search_commit_root
= 1;
735 path1
->skip_locking
= 1;
736 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path1
,
743 ASSERT(path1
->slots
[0]);
747 WARN_ON(cur
->checked
);
748 if (!list_empty(&cur
->upper
)) {
750 * the backref was added previously when processing
751 * backref of type BTRFS_TREE_BLOCK_REF_KEY
753 ASSERT(list_is_singular(&cur
->upper
));
754 edge
= list_entry(cur
->upper
.next
, struct backref_edge
,
756 ASSERT(list_empty(&edge
->list
[UPPER
]));
757 exist
= edge
->node
[UPPER
];
759 * add the upper level block to pending list if we need
763 list_add_tail(&edge
->list
[UPPER
], &list
);
770 eb
= path1
->nodes
[0];
773 if (path1
->slots
[0] >= btrfs_header_nritems(eb
)) {
774 ret
= btrfs_next_leaf(rc
->extent_root
, path1
);
781 eb
= path1
->nodes
[0];
784 btrfs_item_key_to_cpu(eb
, &key
, path1
->slots
[0]);
785 if (key
.objectid
!= cur
->bytenr
) {
790 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
||
791 key
.type
== BTRFS_METADATA_ITEM_KEY
) {
792 ret
= find_inline_backref(eb
, path1
->slots
[0],
800 /* update key for inline back ref */
801 struct btrfs_extent_inline_ref
*iref
;
802 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
803 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
804 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
805 WARN_ON(key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
&&
806 key
.type
!= BTRFS_SHARED_BLOCK_REF_KEY
);
810 ((key
.type
== BTRFS_TREE_BLOCK_REF_KEY
&&
811 exist
->owner
== key
.offset
) ||
812 (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
&&
813 exist
->bytenr
== key
.offset
))) {
818 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
819 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
||
820 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
821 if (key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
822 struct btrfs_extent_ref_v0
*ref0
;
823 ref0
= btrfs_item_ptr(eb
, path1
->slots
[0],
824 struct btrfs_extent_ref_v0
);
825 if (key
.objectid
== key
.offset
) {
826 root
= find_tree_root(rc
, eb
, ref0
);
827 if (root
&& !should_ignore_root(root
))
830 list_add(&cur
->list
, &useless
);
833 if (is_cowonly_root(btrfs_ref_root_v0(eb
,
838 ASSERT(key
.type
!= BTRFS_EXTENT_REF_V0_KEY
);
839 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
) {
841 if (key
.objectid
== key
.offset
) {
843 * only root blocks of reloc trees use
844 * backref of this type.
846 root
= find_reloc_root(rc
, cur
->bytenr
);
852 edge
= alloc_backref_edge(cache
);
857 rb_node
= tree_search(&cache
->rb_root
, key
.offset
);
859 upper
= alloc_backref_node(cache
);
861 free_backref_edge(cache
, edge
);
865 upper
->bytenr
= key
.offset
;
866 upper
->level
= cur
->level
+ 1;
868 * backrefs for the upper level block isn't
869 * cached, add the block to pending list
871 list_add_tail(&edge
->list
[UPPER
], &list
);
873 upper
= rb_entry(rb_node
, struct backref_node
,
875 ASSERT(upper
->checked
);
876 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
878 list_add_tail(&edge
->list
[LOWER
], &cur
->upper
);
879 edge
->node
[LOWER
] = cur
;
880 edge
->node
[UPPER
] = upper
;
883 } else if (key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
) {
887 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
888 root
= read_fs_root(rc
->extent_root
->fs_info
, key
.offset
);
894 if (!test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
))
897 if (btrfs_root_level(&root
->root_item
) == cur
->level
) {
899 ASSERT(btrfs_root_bytenr(&root
->root_item
) ==
901 if (should_ignore_root(root
))
902 list_add(&cur
->list
, &useless
);
908 level
= cur
->level
+ 1;
911 * searching the tree to find upper level blocks
912 * reference the block.
914 path2
->search_commit_root
= 1;
915 path2
->skip_locking
= 1;
916 path2
->lowest_level
= level
;
917 ret
= btrfs_search_slot(NULL
, root
, node_key
, path2
, 0, 0);
918 path2
->lowest_level
= 0;
923 if (ret
> 0 && path2
->slots
[level
] > 0)
924 path2
->slots
[level
]--;
926 eb
= path2
->nodes
[level
];
927 if (btrfs_node_blockptr(eb
, path2
->slots
[level
]) !=
929 btrfs_err(root
->fs_info
,
930 "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)",
931 cur
->bytenr
, level
- 1, root
->objectid
,
932 node_key
->objectid
, node_key
->type
,
939 for (; level
< BTRFS_MAX_LEVEL
; level
++) {
940 if (!path2
->nodes
[level
]) {
941 ASSERT(btrfs_root_bytenr(&root
->root_item
) ==
943 if (should_ignore_root(root
))
944 list_add(&lower
->list
, &useless
);
950 edge
= alloc_backref_edge(cache
);
956 eb
= path2
->nodes
[level
];
957 rb_node
= tree_search(&cache
->rb_root
, eb
->start
);
959 upper
= alloc_backref_node(cache
);
961 free_backref_edge(cache
, edge
);
965 upper
->bytenr
= eb
->start
;
966 upper
->owner
= btrfs_header_owner(eb
);
967 upper
->level
= lower
->level
+ 1;
968 if (!test_bit(BTRFS_ROOT_REF_COWS
,
973 * if we know the block isn't shared
974 * we can void checking its backrefs.
976 if (btrfs_block_can_be_shared(root
, eb
))
982 * add the block to pending list if we
983 * need check its backrefs, we only do this once
984 * while walking up a tree as we will catch
985 * anything else later on.
987 if (!upper
->checked
&& need_check
) {
989 list_add_tail(&edge
->list
[UPPER
],
994 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
997 upper
= rb_entry(rb_node
, struct backref_node
,
999 ASSERT(upper
->checked
);
1000 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
1002 upper
->owner
= btrfs_header_owner(eb
);
1004 list_add_tail(&edge
->list
[LOWER
], &lower
->upper
);
1005 edge
->node
[LOWER
] = lower
;
1006 edge
->node
[UPPER
] = upper
;
1013 btrfs_release_path(path2
);
1016 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
1026 btrfs_release_path(path1
);
1031 /* the pending list isn't empty, take the first block to process */
1032 if (!list_empty(&list
)) {
1033 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1034 list_del_init(&edge
->list
[UPPER
]);
1035 cur
= edge
->node
[UPPER
];
1040 * everything goes well, connect backref nodes and insert backref nodes
1043 ASSERT(node
->checked
);
1044 cowonly
= node
->cowonly
;
1046 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
,
1049 backref_tree_panic(rb_node
, -EEXIST
, node
->bytenr
);
1050 list_add_tail(&node
->lower
, &cache
->leaves
);
1053 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
])
1054 list_add_tail(&edge
->list
[UPPER
], &list
);
1056 while (!list_empty(&list
)) {
1057 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1058 list_del_init(&edge
->list
[UPPER
]);
1059 upper
= edge
->node
[UPPER
];
1060 if (upper
->detached
) {
1061 list_del(&edge
->list
[LOWER
]);
1062 lower
= edge
->node
[LOWER
];
1063 free_backref_edge(cache
, edge
);
1064 if (list_empty(&lower
->upper
))
1065 list_add(&lower
->list
, &useless
);
1069 if (!RB_EMPTY_NODE(&upper
->rb_node
)) {
1070 if (upper
->lowest
) {
1071 list_del_init(&upper
->lower
);
1075 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1079 if (!upper
->checked
) {
1081 * Still want to blow up for developers since this is a
1088 if (cowonly
!= upper
->cowonly
) {
1095 rb_node
= tree_insert(&cache
->rb_root
, upper
->bytenr
,
1098 backref_tree_panic(rb_node
, -EEXIST
,
1102 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1104 list_for_each_entry(edge
, &upper
->upper
, list
[LOWER
])
1105 list_add_tail(&edge
->list
[UPPER
], &list
);
1108 * process useless backref nodes. backref nodes for tree leaves
1109 * are deleted from the cache. backref nodes for upper level
1110 * tree blocks are left in the cache to avoid unnecessary backref
1113 while (!list_empty(&useless
)) {
1114 upper
= list_entry(useless
.next
, struct backref_node
, list
);
1115 list_del_init(&upper
->list
);
1116 ASSERT(list_empty(&upper
->upper
));
1119 if (upper
->lowest
) {
1120 list_del_init(&upper
->lower
);
1123 while (!list_empty(&upper
->lower
)) {
1124 edge
= list_entry(upper
->lower
.next
,
1125 struct backref_edge
, list
[UPPER
]);
1126 list_del(&edge
->list
[UPPER
]);
1127 list_del(&edge
->list
[LOWER
]);
1128 lower
= edge
->node
[LOWER
];
1129 free_backref_edge(cache
, edge
);
1131 if (list_empty(&lower
->upper
))
1132 list_add(&lower
->list
, &useless
);
1134 __mark_block_processed(rc
, upper
);
1135 if (upper
->level
> 0) {
1136 list_add(&upper
->list
, &cache
->detached
);
1137 upper
->detached
= 1;
1139 rb_erase(&upper
->rb_node
, &cache
->rb_root
);
1140 free_backref_node(cache
, upper
);
1144 btrfs_free_path(path1
);
1145 btrfs_free_path(path2
);
1147 while (!list_empty(&useless
)) {
1148 lower
= list_entry(useless
.next
,
1149 struct backref_node
, list
);
1150 list_del_init(&lower
->list
);
1152 while (!list_empty(&list
)) {
1153 edge
= list_first_entry(&list
, struct backref_edge
,
1155 list_del(&edge
->list
[UPPER
]);
1156 list_del(&edge
->list
[LOWER
]);
1157 lower
= edge
->node
[LOWER
];
1158 upper
= edge
->node
[UPPER
];
1159 free_backref_edge(cache
, edge
);
1162 * Lower is no longer linked to any upper backref nodes
1163 * and isn't in the cache, we can free it ourselves.
1165 if (list_empty(&lower
->upper
) &&
1166 RB_EMPTY_NODE(&lower
->rb_node
))
1167 list_add(&lower
->list
, &useless
);
1169 if (!RB_EMPTY_NODE(&upper
->rb_node
))
1172 /* Add this guy's upper edges to the list to process */
1173 list_for_each_entry(edge
, &upper
->upper
, list
[LOWER
])
1174 list_add_tail(&edge
->list
[UPPER
], &list
);
1175 if (list_empty(&upper
->upper
))
1176 list_add(&upper
->list
, &useless
);
1179 while (!list_empty(&useless
)) {
1180 lower
= list_entry(useless
.next
,
1181 struct backref_node
, list
);
1182 list_del_init(&lower
->list
);
1185 free_backref_node(cache
, lower
);
1188 free_backref_node(cache
, node
);
1189 return ERR_PTR(err
);
1191 ASSERT(!node
|| !node
->detached
);
1196 * helper to add backref node for the newly created snapshot.
1197 * the backref node is created by cloning backref node that
1198 * corresponds to root of source tree
1200 static int clone_backref_node(struct btrfs_trans_handle
*trans
,
1201 struct reloc_control
*rc
,
1202 struct btrfs_root
*src
,
1203 struct btrfs_root
*dest
)
1205 struct btrfs_root
*reloc_root
= src
->reloc_root
;
1206 struct backref_cache
*cache
= &rc
->backref_cache
;
1207 struct backref_node
*node
= NULL
;
1208 struct backref_node
*new_node
;
1209 struct backref_edge
*edge
;
1210 struct backref_edge
*new_edge
;
1211 struct rb_node
*rb_node
;
1213 if (cache
->last_trans
> 0)
1214 update_backref_cache(trans
, cache
);
1216 rb_node
= tree_search(&cache
->rb_root
, src
->commit_root
->start
);
1218 node
= rb_entry(rb_node
, struct backref_node
, rb_node
);
1222 BUG_ON(node
->new_bytenr
!= reloc_root
->node
->start
);
1226 rb_node
= tree_search(&cache
->rb_root
,
1227 reloc_root
->commit_root
->start
);
1229 node
= rb_entry(rb_node
, struct backref_node
,
1231 BUG_ON(node
->detached
);
1238 new_node
= alloc_backref_node(cache
);
1242 new_node
->bytenr
= dest
->node
->start
;
1243 new_node
->level
= node
->level
;
1244 new_node
->lowest
= node
->lowest
;
1245 new_node
->checked
= 1;
1246 new_node
->root
= dest
;
1248 if (!node
->lowest
) {
1249 list_for_each_entry(edge
, &node
->lower
, list
[UPPER
]) {
1250 new_edge
= alloc_backref_edge(cache
);
1254 new_edge
->node
[UPPER
] = new_node
;
1255 new_edge
->node
[LOWER
] = edge
->node
[LOWER
];
1256 list_add_tail(&new_edge
->list
[UPPER
],
1260 list_add_tail(&new_node
->lower
, &cache
->leaves
);
1263 rb_node
= tree_insert(&cache
->rb_root
, new_node
->bytenr
,
1264 &new_node
->rb_node
);
1266 backref_tree_panic(rb_node
, -EEXIST
, new_node
->bytenr
);
1268 if (!new_node
->lowest
) {
1269 list_for_each_entry(new_edge
, &new_node
->lower
, list
[UPPER
]) {
1270 list_add_tail(&new_edge
->list
[LOWER
],
1271 &new_edge
->node
[LOWER
]->upper
);
1276 while (!list_empty(&new_node
->lower
)) {
1277 new_edge
= list_entry(new_node
->lower
.next
,
1278 struct backref_edge
, list
[UPPER
]);
1279 list_del(&new_edge
->list
[UPPER
]);
1280 free_backref_edge(cache
, new_edge
);
1282 free_backref_node(cache
, new_node
);
1287 * helper to add 'address of tree root -> reloc tree' mapping
1289 static int __must_check
__add_reloc_root(struct btrfs_root
*root
)
1291 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1292 struct rb_node
*rb_node
;
1293 struct mapping_node
*node
;
1294 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
1296 node
= kmalloc(sizeof(*node
), GFP_NOFS
);
1300 node
->bytenr
= root
->node
->start
;
1303 spin_lock(&rc
->reloc_root_tree
.lock
);
1304 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1305 node
->bytenr
, &node
->rb_node
);
1306 spin_unlock(&rc
->reloc_root_tree
.lock
);
1308 btrfs_panic(fs_info
, -EEXIST
,
1309 "Duplicate root found for start=%llu while inserting into relocation tree",
1315 list_add_tail(&root
->root_list
, &rc
->reloc_roots
);
1320 * helper to delete the 'address of tree root -> reloc tree'
1323 static void __del_reloc_root(struct btrfs_root
*root
)
1325 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1326 struct rb_node
*rb_node
;
1327 struct mapping_node
*node
= NULL
;
1328 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
1330 spin_lock(&rc
->reloc_root_tree
.lock
);
1331 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
,
1334 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
1335 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
1337 spin_unlock(&rc
->reloc_root_tree
.lock
);
1341 BUG_ON((struct btrfs_root
*)node
->data
!= root
);
1343 spin_lock(&fs_info
->trans_lock
);
1344 list_del_init(&root
->root_list
);
1345 spin_unlock(&fs_info
->trans_lock
);
1350 * helper to update the 'address of tree root -> reloc tree'
1353 static int __update_reloc_root(struct btrfs_root
*root
, u64 new_bytenr
)
1355 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1356 struct rb_node
*rb_node
;
1357 struct mapping_node
*node
= NULL
;
1358 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
1360 spin_lock(&rc
->reloc_root_tree
.lock
);
1361 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
,
1364 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
1365 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
1367 spin_unlock(&rc
->reloc_root_tree
.lock
);
1371 BUG_ON((struct btrfs_root
*)node
->data
!= root
);
1373 spin_lock(&rc
->reloc_root_tree
.lock
);
1374 node
->bytenr
= new_bytenr
;
1375 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1376 node
->bytenr
, &node
->rb_node
);
1377 spin_unlock(&rc
->reloc_root_tree
.lock
);
1379 backref_tree_panic(rb_node
, -EEXIST
, node
->bytenr
);
1383 static struct btrfs_root
*create_reloc_root(struct btrfs_trans_handle
*trans
,
1384 struct btrfs_root
*root
, u64 objectid
)
1386 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1387 struct btrfs_root
*reloc_root
;
1388 struct extent_buffer
*eb
;
1389 struct btrfs_root_item
*root_item
;
1390 struct btrfs_key root_key
;
1393 root_item
= kmalloc(sizeof(*root_item
), GFP_NOFS
);
1396 root_key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
1397 root_key
.type
= BTRFS_ROOT_ITEM_KEY
;
1398 root_key
.offset
= objectid
;
1400 if (root
->root_key
.objectid
== objectid
) {
1401 u64 commit_root_gen
;
1403 /* called by btrfs_init_reloc_root */
1404 ret
= btrfs_copy_root(trans
, root
, root
->commit_root
, &eb
,
1405 BTRFS_TREE_RELOC_OBJECTID
);
1408 * Set the last_snapshot field to the generation of the commit
1409 * root - like this ctree.c:btrfs_block_can_be_shared() behaves
1410 * correctly (returns true) when the relocation root is created
1411 * either inside the critical section of a transaction commit
1412 * (through transaction.c:qgroup_account_snapshot()) and when
1413 * it's created before the transaction commit is started.
1415 commit_root_gen
= btrfs_header_generation(root
->commit_root
);
1416 btrfs_set_root_last_snapshot(&root
->root_item
, commit_root_gen
);
1419 * called by btrfs_reloc_post_snapshot_hook.
1420 * the source tree is a reloc tree, all tree blocks
1421 * modified after it was created have RELOC flag
1422 * set in their headers. so it's OK to not update
1423 * the 'last_snapshot'.
1425 ret
= btrfs_copy_root(trans
, root
, root
->node
, &eb
,
1426 BTRFS_TREE_RELOC_OBJECTID
);
1430 memcpy(root_item
, &root
->root_item
, sizeof(*root_item
));
1431 btrfs_set_root_bytenr(root_item
, eb
->start
);
1432 btrfs_set_root_level(root_item
, btrfs_header_level(eb
));
1433 btrfs_set_root_generation(root_item
, trans
->transid
);
1435 if (root
->root_key
.objectid
== objectid
) {
1436 btrfs_set_root_refs(root_item
, 0);
1437 memset(&root_item
->drop_progress
, 0,
1438 sizeof(struct btrfs_disk_key
));
1439 root_item
->drop_level
= 0;
1442 btrfs_tree_unlock(eb
);
1443 free_extent_buffer(eb
);
1445 ret
= btrfs_insert_root(trans
, fs_info
->tree_root
,
1446 &root_key
, root_item
);
1450 reloc_root
= btrfs_read_fs_root(fs_info
->tree_root
, &root_key
);
1451 BUG_ON(IS_ERR(reloc_root
));
1452 reloc_root
->last_trans
= trans
->transid
;
1457 * create reloc tree for a given fs tree. reloc tree is just a
1458 * snapshot of the fs tree with special root objectid.
1460 int btrfs_init_reloc_root(struct btrfs_trans_handle
*trans
,
1461 struct btrfs_root
*root
)
1463 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1464 struct btrfs_root
*reloc_root
;
1465 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
1466 struct btrfs_block_rsv
*rsv
;
1470 if (root
->reloc_root
) {
1471 reloc_root
= root
->reloc_root
;
1472 reloc_root
->last_trans
= trans
->transid
;
1476 if (!rc
|| !rc
->create_reloc_tree
||
1477 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1480 if (!trans
->reloc_reserved
) {
1481 rsv
= trans
->block_rsv
;
1482 trans
->block_rsv
= rc
->block_rsv
;
1485 reloc_root
= create_reloc_root(trans
, root
, root
->root_key
.objectid
);
1487 trans
->block_rsv
= rsv
;
1489 ret
= __add_reloc_root(reloc_root
);
1491 root
->reloc_root
= reloc_root
;
1496 * update root item of reloc tree
1498 int btrfs_update_reloc_root(struct btrfs_trans_handle
*trans
,
1499 struct btrfs_root
*root
)
1501 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1502 struct btrfs_root
*reloc_root
;
1503 struct btrfs_root_item
*root_item
;
1506 if (!root
->reloc_root
)
1509 reloc_root
= root
->reloc_root
;
1510 root_item
= &reloc_root
->root_item
;
1512 if (fs_info
->reloc_ctl
->merge_reloc_tree
&&
1513 btrfs_root_refs(root_item
) == 0) {
1514 root
->reloc_root
= NULL
;
1515 __del_reloc_root(reloc_root
);
1518 if (reloc_root
->commit_root
!= reloc_root
->node
) {
1519 btrfs_set_root_node(root_item
, reloc_root
->node
);
1520 free_extent_buffer(reloc_root
->commit_root
);
1521 reloc_root
->commit_root
= btrfs_root_node(reloc_root
);
1524 ret
= btrfs_update_root(trans
, fs_info
->tree_root
,
1525 &reloc_root
->root_key
, root_item
);
1533 * helper to find first cached inode with inode number >= objectid
1536 static struct inode
*find_next_inode(struct btrfs_root
*root
, u64 objectid
)
1538 struct rb_node
*node
;
1539 struct rb_node
*prev
;
1540 struct btrfs_inode
*entry
;
1541 struct inode
*inode
;
1543 spin_lock(&root
->inode_lock
);
1545 node
= root
->inode_tree
.rb_node
;
1549 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1551 if (objectid
< btrfs_ino(entry
))
1552 node
= node
->rb_left
;
1553 else if (objectid
> btrfs_ino(entry
))
1554 node
= node
->rb_right
;
1560 entry
= rb_entry(prev
, struct btrfs_inode
, rb_node
);
1561 if (objectid
<= btrfs_ino(entry
)) {
1565 prev
= rb_next(prev
);
1569 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1570 inode
= igrab(&entry
->vfs_inode
);
1572 spin_unlock(&root
->inode_lock
);
1576 objectid
= btrfs_ino(entry
) + 1;
1577 if (cond_resched_lock(&root
->inode_lock
))
1580 node
= rb_next(node
);
1582 spin_unlock(&root
->inode_lock
);
1586 static int in_block_group(u64 bytenr
,
1587 struct btrfs_block_group_cache
*block_group
)
1589 if (bytenr
>= block_group
->key
.objectid
&&
1590 bytenr
< block_group
->key
.objectid
+ block_group
->key
.offset
)
1596 * get new location of data
1598 static int get_new_location(struct inode
*reloc_inode
, u64
*new_bytenr
,
1599 u64 bytenr
, u64 num_bytes
)
1601 struct btrfs_root
*root
= BTRFS_I(reloc_inode
)->root
;
1602 struct btrfs_path
*path
;
1603 struct btrfs_file_extent_item
*fi
;
1604 struct extent_buffer
*leaf
;
1607 path
= btrfs_alloc_path();
1611 bytenr
-= BTRFS_I(reloc_inode
)->index_cnt
;
1612 ret
= btrfs_lookup_file_extent(NULL
, root
, path
,
1613 btrfs_ino(BTRFS_I(reloc_inode
)), bytenr
, 0);
1621 leaf
= path
->nodes
[0];
1622 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
1623 struct btrfs_file_extent_item
);
1625 BUG_ON(btrfs_file_extent_offset(leaf
, fi
) ||
1626 btrfs_file_extent_compression(leaf
, fi
) ||
1627 btrfs_file_extent_encryption(leaf
, fi
) ||
1628 btrfs_file_extent_other_encoding(leaf
, fi
));
1630 if (num_bytes
!= btrfs_file_extent_disk_num_bytes(leaf
, fi
)) {
1635 *new_bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1638 btrfs_free_path(path
);
1643 * update file extent items in the tree leaf to point to
1644 * the new locations.
1646 static noinline_for_stack
1647 int replace_file_extents(struct btrfs_trans_handle
*trans
,
1648 struct reloc_control
*rc
,
1649 struct btrfs_root
*root
,
1650 struct extent_buffer
*leaf
)
1652 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1653 struct btrfs_key key
;
1654 struct btrfs_file_extent_item
*fi
;
1655 struct inode
*inode
= NULL
;
1667 if (rc
->stage
!= UPDATE_DATA_PTRS
)
1670 /* reloc trees always use full backref */
1671 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1672 parent
= leaf
->start
;
1676 nritems
= btrfs_header_nritems(leaf
);
1677 for (i
= 0; i
< nritems
; i
++) {
1679 btrfs_item_key_to_cpu(leaf
, &key
, i
);
1680 if (key
.type
!= BTRFS_EXTENT_DATA_KEY
)
1682 fi
= btrfs_item_ptr(leaf
, i
, struct btrfs_file_extent_item
);
1683 if (btrfs_file_extent_type(leaf
, fi
) ==
1684 BTRFS_FILE_EXTENT_INLINE
)
1686 bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1687 num_bytes
= btrfs_file_extent_disk_num_bytes(leaf
, fi
);
1690 if (!in_block_group(bytenr
, rc
->block_group
))
1694 * if we are modifying block in fs tree, wait for readpage
1695 * to complete and drop the extent cache
1697 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
) {
1699 inode
= find_next_inode(root
, key
.objectid
);
1701 } else if (inode
&& btrfs_ino(BTRFS_I(inode
)) < key
.objectid
) {
1702 btrfs_add_delayed_iput(inode
);
1703 inode
= find_next_inode(root
, key
.objectid
);
1705 if (inode
&& btrfs_ino(BTRFS_I(inode
)) == key
.objectid
) {
1707 btrfs_file_extent_num_bytes(leaf
, fi
);
1708 WARN_ON(!IS_ALIGNED(key
.offset
,
1709 fs_info
->sectorsize
));
1710 WARN_ON(!IS_ALIGNED(end
, fs_info
->sectorsize
));
1712 ret
= try_lock_extent(&BTRFS_I(inode
)->io_tree
,
1717 btrfs_drop_extent_cache(BTRFS_I(inode
),
1718 key
.offset
, end
, 1);
1719 unlock_extent(&BTRFS_I(inode
)->io_tree
,
1724 ret
= get_new_location(rc
->data_inode
, &new_bytenr
,
1728 * Don't have to abort since we've not changed anything
1729 * in the file extent yet.
1734 btrfs_set_file_extent_disk_bytenr(leaf
, fi
, new_bytenr
);
1737 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
1738 ret
= btrfs_inc_extent_ref(trans
, fs_info
, new_bytenr
,
1740 btrfs_header_owner(leaf
),
1741 key
.objectid
, key
.offset
);
1743 btrfs_abort_transaction(trans
, ret
);
1747 ret
= btrfs_free_extent(trans
, fs_info
, bytenr
, num_bytes
,
1748 parent
, btrfs_header_owner(leaf
),
1749 key
.objectid
, key
.offset
);
1751 btrfs_abort_transaction(trans
, ret
);
1756 btrfs_mark_buffer_dirty(leaf
);
1758 btrfs_add_delayed_iput(inode
);
1762 static noinline_for_stack
1763 int memcmp_node_keys(struct extent_buffer
*eb
, int slot
,
1764 struct btrfs_path
*path
, int level
)
1766 struct btrfs_disk_key key1
;
1767 struct btrfs_disk_key key2
;
1768 btrfs_node_key(eb
, &key1
, slot
);
1769 btrfs_node_key(path
->nodes
[level
], &key2
, path
->slots
[level
]);
1770 return memcmp(&key1
, &key2
, sizeof(key1
));
1774 * try to replace tree blocks in fs tree with the new blocks
1775 * in reloc tree. tree blocks haven't been modified since the
1776 * reloc tree was create can be replaced.
1778 * if a block was replaced, level of the block + 1 is returned.
1779 * if no block got replaced, 0 is returned. if there are other
1780 * errors, a negative error number is returned.
1782 static noinline_for_stack
1783 int replace_path(struct btrfs_trans_handle
*trans
,
1784 struct btrfs_root
*dest
, struct btrfs_root
*src
,
1785 struct btrfs_path
*path
, struct btrfs_key
*next_key
,
1786 int lowest_level
, int max_level
)
1788 struct btrfs_fs_info
*fs_info
= dest
->fs_info
;
1789 struct extent_buffer
*eb
;
1790 struct extent_buffer
*parent
;
1791 struct btrfs_key key
;
1803 BUG_ON(src
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
);
1804 BUG_ON(dest
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
);
1806 last_snapshot
= btrfs_root_last_snapshot(&src
->root_item
);
1808 slot
= path
->slots
[lowest_level
];
1809 btrfs_node_key_to_cpu(path
->nodes
[lowest_level
], &key
, slot
);
1811 eb
= btrfs_lock_root_node(dest
);
1812 btrfs_set_lock_blocking(eb
);
1813 level
= btrfs_header_level(eb
);
1815 if (level
< lowest_level
) {
1816 btrfs_tree_unlock(eb
);
1817 free_extent_buffer(eb
);
1822 ret
= btrfs_cow_block(trans
, dest
, eb
, NULL
, 0, &eb
);
1825 btrfs_set_lock_blocking(eb
);
1828 next_key
->objectid
= (u64
)-1;
1829 next_key
->type
= (u8
)-1;
1830 next_key
->offset
= (u64
)-1;
1835 level
= btrfs_header_level(parent
);
1836 BUG_ON(level
< lowest_level
);
1838 ret
= btrfs_bin_search(parent
, &key
, level
, &slot
);
1839 if (ret
&& slot
> 0)
1842 if (next_key
&& slot
+ 1 < btrfs_header_nritems(parent
))
1843 btrfs_node_key_to_cpu(parent
, next_key
, slot
+ 1);
1845 old_bytenr
= btrfs_node_blockptr(parent
, slot
);
1846 blocksize
= fs_info
->nodesize
;
1847 old_ptr_gen
= btrfs_node_ptr_generation(parent
, slot
);
1849 if (level
<= max_level
) {
1850 eb
= path
->nodes
[level
];
1851 new_bytenr
= btrfs_node_blockptr(eb
,
1852 path
->slots
[level
]);
1853 new_ptr_gen
= btrfs_node_ptr_generation(eb
,
1854 path
->slots
[level
]);
1860 if (WARN_ON(new_bytenr
> 0 && new_bytenr
== old_bytenr
)) {
1865 if (new_bytenr
== 0 || old_ptr_gen
> last_snapshot
||
1866 memcmp_node_keys(parent
, slot
, path
, level
)) {
1867 if (level
<= lowest_level
) {
1872 eb
= read_tree_block(fs_info
, old_bytenr
, old_ptr_gen
);
1876 } else if (!extent_buffer_uptodate(eb
)) {
1878 free_extent_buffer(eb
);
1881 btrfs_tree_lock(eb
);
1883 ret
= btrfs_cow_block(trans
, dest
, eb
, parent
,
1887 btrfs_set_lock_blocking(eb
);
1889 btrfs_tree_unlock(parent
);
1890 free_extent_buffer(parent
);
1897 btrfs_tree_unlock(parent
);
1898 free_extent_buffer(parent
);
1903 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
1904 path
->slots
[level
]);
1905 btrfs_release_path(path
);
1907 path
->lowest_level
= level
;
1908 ret
= btrfs_search_slot(trans
, src
, &key
, path
, 0, 1);
1909 path
->lowest_level
= 0;
1913 * Info qgroup to trace both subtrees.
1915 * We must trace both trees.
1916 * 1) Tree reloc subtree
1917 * If not traced, we will leak data numbers
1919 * If not traced, we will double count old data
1920 * and tree block numbers, if current trans doesn't free
1921 * data reloc tree inode.
1923 ret
= btrfs_qgroup_trace_subtree(trans
, src
, parent
,
1924 btrfs_header_generation(parent
),
1925 btrfs_header_level(parent
));
1928 ret
= btrfs_qgroup_trace_subtree(trans
, dest
,
1930 btrfs_header_generation(path
->nodes
[level
]),
1931 btrfs_header_level(path
->nodes
[level
]));
1936 * swap blocks in fs tree and reloc tree.
1938 btrfs_set_node_blockptr(parent
, slot
, new_bytenr
);
1939 btrfs_set_node_ptr_generation(parent
, slot
, new_ptr_gen
);
1940 btrfs_mark_buffer_dirty(parent
);
1942 btrfs_set_node_blockptr(path
->nodes
[level
],
1943 path
->slots
[level
], old_bytenr
);
1944 btrfs_set_node_ptr_generation(path
->nodes
[level
],
1945 path
->slots
[level
], old_ptr_gen
);
1946 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
1948 ret
= btrfs_inc_extent_ref(trans
, fs_info
, old_bytenr
,
1949 blocksize
, path
->nodes
[level
]->start
,
1950 src
->root_key
.objectid
, level
- 1, 0);
1952 ret
= btrfs_inc_extent_ref(trans
, fs_info
, new_bytenr
,
1953 blocksize
, 0, dest
->root_key
.objectid
,
1957 ret
= btrfs_free_extent(trans
, fs_info
, new_bytenr
, blocksize
,
1958 path
->nodes
[level
]->start
,
1959 src
->root_key
.objectid
, level
- 1, 0);
1962 ret
= btrfs_free_extent(trans
, fs_info
, old_bytenr
, blocksize
,
1963 0, dest
->root_key
.objectid
, level
- 1,
1967 btrfs_unlock_up_safe(path
, 0);
1972 btrfs_tree_unlock(parent
);
1973 free_extent_buffer(parent
);
1978 * helper to find next relocated block in reloc tree
1980 static noinline_for_stack
1981 int walk_up_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1984 struct extent_buffer
*eb
;
1989 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1991 for (i
= 0; i
< *level
; i
++) {
1992 free_extent_buffer(path
->nodes
[i
]);
1993 path
->nodes
[i
] = NULL
;
1996 for (i
= *level
; i
< BTRFS_MAX_LEVEL
&& path
->nodes
[i
]; i
++) {
1997 eb
= path
->nodes
[i
];
1998 nritems
= btrfs_header_nritems(eb
);
1999 while (path
->slots
[i
] + 1 < nritems
) {
2001 if (btrfs_node_ptr_generation(eb
, path
->slots
[i
]) <=
2008 free_extent_buffer(path
->nodes
[i
]);
2009 path
->nodes
[i
] = NULL
;
2015 * walk down reloc tree to find relocated block of lowest level
2017 static noinline_for_stack
2018 int walk_down_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
2021 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
2022 struct extent_buffer
*eb
= NULL
;
2029 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
2031 for (i
= *level
; i
> 0; i
--) {
2032 eb
= path
->nodes
[i
];
2033 nritems
= btrfs_header_nritems(eb
);
2034 while (path
->slots
[i
] < nritems
) {
2035 ptr_gen
= btrfs_node_ptr_generation(eb
, path
->slots
[i
]);
2036 if (ptr_gen
> last_snapshot
)
2040 if (path
->slots
[i
] >= nritems
) {
2051 bytenr
= btrfs_node_blockptr(eb
, path
->slots
[i
]);
2052 eb
= read_tree_block(fs_info
, bytenr
, ptr_gen
);
2055 } else if (!extent_buffer_uptodate(eb
)) {
2056 free_extent_buffer(eb
);
2059 BUG_ON(btrfs_header_level(eb
) != i
- 1);
2060 path
->nodes
[i
- 1] = eb
;
2061 path
->slots
[i
- 1] = 0;
2067 * invalidate extent cache for file extents whose key in range of
2068 * [min_key, max_key)
2070 static int invalidate_extent_cache(struct btrfs_root
*root
,
2071 struct btrfs_key
*min_key
,
2072 struct btrfs_key
*max_key
)
2074 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
2075 struct inode
*inode
= NULL
;
2080 objectid
= min_key
->objectid
;
2085 if (objectid
> max_key
->objectid
)
2088 inode
= find_next_inode(root
, objectid
);
2091 ino
= btrfs_ino(BTRFS_I(inode
));
2093 if (ino
> max_key
->objectid
) {
2099 if (!S_ISREG(inode
->i_mode
))
2102 if (unlikely(min_key
->objectid
== ino
)) {
2103 if (min_key
->type
> BTRFS_EXTENT_DATA_KEY
)
2105 if (min_key
->type
< BTRFS_EXTENT_DATA_KEY
)
2108 start
= min_key
->offset
;
2109 WARN_ON(!IS_ALIGNED(start
, fs_info
->sectorsize
));
2115 if (unlikely(max_key
->objectid
== ino
)) {
2116 if (max_key
->type
< BTRFS_EXTENT_DATA_KEY
)
2118 if (max_key
->type
> BTRFS_EXTENT_DATA_KEY
) {
2121 if (max_key
->offset
== 0)
2123 end
= max_key
->offset
;
2124 WARN_ON(!IS_ALIGNED(end
, fs_info
->sectorsize
));
2131 /* the lock_extent waits for readpage to complete */
2132 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2133 btrfs_drop_extent_cache(BTRFS_I(inode
), start
, end
, 1);
2134 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2139 static int find_next_key(struct btrfs_path
*path
, int level
,
2140 struct btrfs_key
*key
)
2143 while (level
< BTRFS_MAX_LEVEL
) {
2144 if (!path
->nodes
[level
])
2146 if (path
->slots
[level
] + 1 <
2147 btrfs_header_nritems(path
->nodes
[level
])) {
2148 btrfs_node_key_to_cpu(path
->nodes
[level
], key
,
2149 path
->slots
[level
] + 1);
2158 * merge the relocated tree blocks in reloc tree with corresponding
2161 static noinline_for_stack
int merge_reloc_root(struct reloc_control
*rc
,
2162 struct btrfs_root
*root
)
2164 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
2165 LIST_HEAD(inode_list
);
2166 struct btrfs_key key
;
2167 struct btrfs_key next_key
;
2168 struct btrfs_trans_handle
*trans
= NULL
;
2169 struct btrfs_root
*reloc_root
;
2170 struct btrfs_root_item
*root_item
;
2171 struct btrfs_path
*path
;
2172 struct extent_buffer
*leaf
;
2180 path
= btrfs_alloc_path();
2183 path
->reada
= READA_FORWARD
;
2185 reloc_root
= root
->reloc_root
;
2186 root_item
= &reloc_root
->root_item
;
2188 if (btrfs_disk_key_objectid(&root_item
->drop_progress
) == 0) {
2189 level
= btrfs_root_level(root_item
);
2190 extent_buffer_get(reloc_root
->node
);
2191 path
->nodes
[level
] = reloc_root
->node
;
2192 path
->slots
[level
] = 0;
2194 btrfs_disk_key_to_cpu(&key
, &root_item
->drop_progress
);
2196 level
= root_item
->drop_level
;
2198 path
->lowest_level
= level
;
2199 ret
= btrfs_search_slot(NULL
, reloc_root
, &key
, path
, 0, 0);
2200 path
->lowest_level
= 0;
2202 btrfs_free_path(path
);
2206 btrfs_node_key_to_cpu(path
->nodes
[level
], &next_key
,
2207 path
->slots
[level
]);
2208 WARN_ON(memcmp(&key
, &next_key
, sizeof(key
)));
2210 btrfs_unlock_up_safe(path
, 0);
2213 min_reserved
= fs_info
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2214 memset(&next_key
, 0, sizeof(next_key
));
2217 ret
= btrfs_block_rsv_refill(root
, rc
->block_rsv
, min_reserved
,
2218 BTRFS_RESERVE_FLUSH_ALL
);
2223 trans
= btrfs_start_transaction(root
, 0);
2224 if (IS_ERR(trans
)) {
2225 err
= PTR_ERR(trans
);
2229 trans
->block_rsv
= rc
->block_rsv
;
2234 ret
= walk_down_reloc_tree(reloc_root
, path
, &level
);
2242 if (!find_next_key(path
, level
, &key
) &&
2243 btrfs_comp_cpu_keys(&next_key
, &key
) >= 0) {
2246 ret
= replace_path(trans
, root
, reloc_root
, path
,
2247 &next_key
, level
, max_level
);
2256 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
2257 path
->slots
[level
]);
2261 ret
= walk_up_reloc_tree(reloc_root
, path
, &level
);
2267 * save the merging progress in the drop_progress.
2268 * this is OK since root refs == 1 in this case.
2270 btrfs_node_key(path
->nodes
[level
], &root_item
->drop_progress
,
2271 path
->slots
[level
]);
2272 root_item
->drop_level
= level
;
2274 btrfs_end_transaction_throttle(trans
);
2277 btrfs_btree_balance_dirty(fs_info
);
2279 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2280 invalidate_extent_cache(root
, &key
, &next_key
);
2284 * handle the case only one block in the fs tree need to be
2285 * relocated and the block is tree root.
2287 leaf
= btrfs_lock_root_node(root
);
2288 ret
= btrfs_cow_block(trans
, root
, leaf
, NULL
, 0, &leaf
);
2289 btrfs_tree_unlock(leaf
);
2290 free_extent_buffer(leaf
);
2294 btrfs_free_path(path
);
2297 memset(&root_item
->drop_progress
, 0,
2298 sizeof(root_item
->drop_progress
));
2299 root_item
->drop_level
= 0;
2300 btrfs_set_root_refs(root_item
, 0);
2301 btrfs_update_reloc_root(trans
, root
);
2305 btrfs_end_transaction_throttle(trans
);
2307 btrfs_btree_balance_dirty(fs_info
);
2309 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2310 invalidate_extent_cache(root
, &key
, &next_key
);
2315 static noinline_for_stack
2316 int prepare_to_merge(struct reloc_control
*rc
, int err
)
2318 struct btrfs_root
*root
= rc
->extent_root
;
2319 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
2320 struct btrfs_root
*reloc_root
;
2321 struct btrfs_trans_handle
*trans
;
2322 LIST_HEAD(reloc_roots
);
2326 mutex_lock(&fs_info
->reloc_mutex
);
2327 rc
->merging_rsv_size
+= fs_info
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2328 rc
->merging_rsv_size
+= rc
->nodes_relocated
* 2;
2329 mutex_unlock(&fs_info
->reloc_mutex
);
2333 num_bytes
= rc
->merging_rsv_size
;
2334 ret
= btrfs_block_rsv_add(root
, rc
->block_rsv
, num_bytes
,
2335 BTRFS_RESERVE_FLUSH_ALL
);
2340 trans
= btrfs_join_transaction(rc
->extent_root
);
2341 if (IS_ERR(trans
)) {
2343 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
,
2345 return PTR_ERR(trans
);
2349 if (num_bytes
!= rc
->merging_rsv_size
) {
2350 btrfs_end_transaction(trans
);
2351 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
,
2357 rc
->merge_reloc_tree
= 1;
2359 while (!list_empty(&rc
->reloc_roots
)) {
2360 reloc_root
= list_entry(rc
->reloc_roots
.next
,
2361 struct btrfs_root
, root_list
);
2362 list_del_init(&reloc_root
->root_list
);
2364 root
= read_fs_root(fs_info
, reloc_root
->root_key
.offset
);
2365 BUG_ON(IS_ERR(root
));
2366 BUG_ON(root
->reloc_root
!= reloc_root
);
2369 * set reference count to 1, so btrfs_recover_relocation
2370 * knows it should resumes merging
2373 btrfs_set_root_refs(&reloc_root
->root_item
, 1);
2374 btrfs_update_reloc_root(trans
, root
);
2376 list_add(&reloc_root
->root_list
, &reloc_roots
);
2379 list_splice(&reloc_roots
, &rc
->reloc_roots
);
2382 btrfs_commit_transaction(trans
);
2384 btrfs_end_transaction(trans
);
2388 static noinline_for_stack
2389 void free_reloc_roots(struct list_head
*list
)
2391 struct btrfs_root
*reloc_root
;
2393 while (!list_empty(list
)) {
2394 reloc_root
= list_entry(list
->next
, struct btrfs_root
,
2396 free_extent_buffer(reloc_root
->node
);
2397 free_extent_buffer(reloc_root
->commit_root
);
2398 reloc_root
->node
= NULL
;
2399 reloc_root
->commit_root
= NULL
;
2400 __del_reloc_root(reloc_root
);
2404 static noinline_for_stack
2405 void merge_reloc_roots(struct reloc_control
*rc
)
2407 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
2408 struct btrfs_root
*root
;
2409 struct btrfs_root
*reloc_root
;
2410 LIST_HEAD(reloc_roots
);
2414 root
= rc
->extent_root
;
2417 * this serializes us with btrfs_record_root_in_transaction,
2418 * we have to make sure nobody is in the middle of
2419 * adding their roots to the list while we are
2422 mutex_lock(&fs_info
->reloc_mutex
);
2423 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
2424 mutex_unlock(&fs_info
->reloc_mutex
);
2426 while (!list_empty(&reloc_roots
)) {
2428 reloc_root
= list_entry(reloc_roots
.next
,
2429 struct btrfs_root
, root_list
);
2431 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
2432 root
= read_fs_root(fs_info
,
2433 reloc_root
->root_key
.offset
);
2434 BUG_ON(IS_ERR(root
));
2435 BUG_ON(root
->reloc_root
!= reloc_root
);
2437 ret
= merge_reloc_root(rc
, root
);
2439 if (list_empty(&reloc_root
->root_list
))
2440 list_add_tail(&reloc_root
->root_list
,
2445 list_del_init(&reloc_root
->root_list
);
2448 ret
= btrfs_drop_snapshot(reloc_root
, rc
->block_rsv
, 0, 1);
2450 if (list_empty(&reloc_root
->root_list
))
2451 list_add_tail(&reloc_root
->root_list
,
2463 btrfs_handle_fs_error(fs_info
, ret
, NULL
);
2464 if (!list_empty(&reloc_roots
))
2465 free_reloc_roots(&reloc_roots
);
2467 /* new reloc root may be added */
2468 mutex_lock(&fs_info
->reloc_mutex
);
2469 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
2470 mutex_unlock(&fs_info
->reloc_mutex
);
2471 if (!list_empty(&reloc_roots
))
2472 free_reloc_roots(&reloc_roots
);
2475 BUG_ON(!RB_EMPTY_ROOT(&rc
->reloc_root_tree
.rb_root
));
2478 static void free_block_list(struct rb_root
*blocks
)
2480 struct tree_block
*block
;
2481 struct rb_node
*rb_node
;
2482 while ((rb_node
= rb_first(blocks
))) {
2483 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2484 rb_erase(rb_node
, blocks
);
2489 static int record_reloc_root_in_trans(struct btrfs_trans_handle
*trans
,
2490 struct btrfs_root
*reloc_root
)
2492 struct btrfs_fs_info
*fs_info
= reloc_root
->fs_info
;
2493 struct btrfs_root
*root
;
2495 if (reloc_root
->last_trans
== trans
->transid
)
2498 root
= read_fs_root(fs_info
, reloc_root
->root_key
.offset
);
2499 BUG_ON(IS_ERR(root
));
2500 BUG_ON(root
->reloc_root
!= reloc_root
);
2502 return btrfs_record_root_in_trans(trans
, root
);
2505 static noinline_for_stack
2506 struct btrfs_root
*select_reloc_root(struct btrfs_trans_handle
*trans
,
2507 struct reloc_control
*rc
,
2508 struct backref_node
*node
,
2509 struct backref_edge
*edges
[])
2511 struct backref_node
*next
;
2512 struct btrfs_root
*root
;
2518 next
= walk_up_backref(next
, edges
, &index
);
2521 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
));
2523 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
2524 record_reloc_root_in_trans(trans
, root
);
2528 btrfs_record_root_in_trans(trans
, root
);
2529 root
= root
->reloc_root
;
2531 if (next
->new_bytenr
!= root
->node
->start
) {
2532 BUG_ON(next
->new_bytenr
);
2533 BUG_ON(!list_empty(&next
->list
));
2534 next
->new_bytenr
= root
->node
->start
;
2536 list_add_tail(&next
->list
,
2537 &rc
->backref_cache
.changed
);
2538 __mark_block_processed(rc
, next
);
2544 next
= walk_down_backref(edges
, &index
);
2545 if (!next
|| next
->level
<= node
->level
)
2552 /* setup backref node path for btrfs_reloc_cow_block */
2554 rc
->backref_cache
.path
[next
->level
] = next
;
2557 next
= edges
[index
]->node
[UPPER
];
2563 * select a tree root for relocation. return NULL if the block
2564 * is reference counted. we should use do_relocation() in this
2565 * case. return a tree root pointer if the block isn't reference
2566 * counted. return -ENOENT if the block is root of reloc tree.
2568 static noinline_for_stack
2569 struct btrfs_root
*select_one_root(struct backref_node
*node
)
2571 struct backref_node
*next
;
2572 struct btrfs_root
*root
;
2573 struct btrfs_root
*fs_root
= NULL
;
2574 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2580 next
= walk_up_backref(next
, edges
, &index
);
2584 /* no other choice for non-references counted tree */
2585 if (!test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
))
2588 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
)
2594 next
= walk_down_backref(edges
, &index
);
2595 if (!next
|| next
->level
<= node
->level
)
2600 return ERR_PTR(-ENOENT
);
2604 static noinline_for_stack
2605 u64
calcu_metadata_size(struct reloc_control
*rc
,
2606 struct backref_node
*node
, int reserve
)
2608 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
2609 struct backref_node
*next
= node
;
2610 struct backref_edge
*edge
;
2611 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2615 BUG_ON(reserve
&& node
->processed
);
2620 if (next
->processed
&& (reserve
|| next
!= node
))
2623 num_bytes
+= fs_info
->nodesize
;
2625 if (list_empty(&next
->upper
))
2628 edge
= list_entry(next
->upper
.next
,
2629 struct backref_edge
, list
[LOWER
]);
2630 edges
[index
++] = edge
;
2631 next
= edge
->node
[UPPER
];
2633 next
= walk_down_backref(edges
, &index
);
2638 static int reserve_metadata_space(struct btrfs_trans_handle
*trans
,
2639 struct reloc_control
*rc
,
2640 struct backref_node
*node
)
2642 struct btrfs_root
*root
= rc
->extent_root
;
2643 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
2648 num_bytes
= calcu_metadata_size(rc
, node
, 1) * 2;
2650 trans
->block_rsv
= rc
->block_rsv
;
2651 rc
->reserved_bytes
+= num_bytes
;
2654 * We are under a transaction here so we can only do limited flushing.
2655 * If we get an enospc just kick back -EAGAIN so we know to drop the
2656 * transaction and try to refill when we can flush all the things.
2658 ret
= btrfs_block_rsv_refill(root
, rc
->block_rsv
, num_bytes
,
2659 BTRFS_RESERVE_FLUSH_LIMIT
);
2661 tmp
= fs_info
->nodesize
* RELOCATION_RESERVED_NODES
;
2662 while (tmp
<= rc
->reserved_bytes
)
2665 * only one thread can access block_rsv at this point,
2666 * so we don't need hold lock to protect block_rsv.
2667 * we expand more reservation size here to allow enough
2668 * space for relocation and we will return eailer in
2671 rc
->block_rsv
->size
= tmp
+ fs_info
->nodesize
*
2672 RELOCATION_RESERVED_NODES
;
2680 * relocate a block tree, and then update pointers in upper level
2681 * blocks that reference the block to point to the new location.
2683 * if called by link_to_upper, the block has already been relocated.
2684 * in that case this function just updates pointers.
2686 static int do_relocation(struct btrfs_trans_handle
*trans
,
2687 struct reloc_control
*rc
,
2688 struct backref_node
*node
,
2689 struct btrfs_key
*key
,
2690 struct btrfs_path
*path
, int lowest
)
2692 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
2693 struct backref_node
*upper
;
2694 struct backref_edge
*edge
;
2695 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2696 struct btrfs_root
*root
;
2697 struct extent_buffer
*eb
;
2705 BUG_ON(lowest
&& node
->eb
);
2707 path
->lowest_level
= node
->level
+ 1;
2708 rc
->backref_cache
.path
[node
->level
] = node
;
2709 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
]) {
2712 upper
= edge
->node
[UPPER
];
2713 root
= select_reloc_root(trans
, rc
, upper
, edges
);
2716 if (upper
->eb
&& !upper
->locked
) {
2718 ret
= btrfs_bin_search(upper
->eb
, key
,
2719 upper
->level
, &slot
);
2721 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2722 if (node
->eb
->start
== bytenr
)
2725 drop_node_buffer(upper
);
2729 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2736 btrfs_release_path(path
);
2741 upper
->eb
= path
->nodes
[upper
->level
];
2742 path
->nodes
[upper
->level
] = NULL
;
2744 BUG_ON(upper
->eb
!= path
->nodes
[upper
->level
]);
2748 path
->locks
[upper
->level
] = 0;
2750 slot
= path
->slots
[upper
->level
];
2751 btrfs_release_path(path
);
2753 ret
= btrfs_bin_search(upper
->eb
, key
, upper
->level
,
2758 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2760 if (bytenr
!= node
->bytenr
) {
2761 btrfs_err(root
->fs_info
,
2762 "lowest leaf/node mismatch: bytenr %llu node->bytenr %llu slot %d upper %llu",
2763 bytenr
, node
->bytenr
, slot
,
2769 if (node
->eb
->start
== bytenr
)
2773 blocksize
= root
->fs_info
->nodesize
;
2774 generation
= btrfs_node_ptr_generation(upper
->eb
, slot
);
2775 eb
= read_tree_block(fs_info
, bytenr
, generation
);
2779 } else if (!extent_buffer_uptodate(eb
)) {
2780 free_extent_buffer(eb
);
2784 btrfs_tree_lock(eb
);
2785 btrfs_set_lock_blocking(eb
);
2788 ret
= btrfs_cow_block(trans
, root
, eb
, upper
->eb
,
2790 btrfs_tree_unlock(eb
);
2791 free_extent_buffer(eb
);
2796 BUG_ON(node
->eb
!= eb
);
2798 btrfs_set_node_blockptr(upper
->eb
, slot
,
2800 btrfs_set_node_ptr_generation(upper
->eb
, slot
,
2802 btrfs_mark_buffer_dirty(upper
->eb
);
2804 ret
= btrfs_inc_extent_ref(trans
, root
->fs_info
,
2805 node
->eb
->start
, blocksize
,
2807 btrfs_header_owner(upper
->eb
),
2811 ret
= btrfs_drop_subtree(trans
, root
, eb
, upper
->eb
);
2815 if (!upper
->pending
)
2816 drop_node_buffer(upper
);
2818 unlock_node_buffer(upper
);
2823 if (!err
&& node
->pending
) {
2824 drop_node_buffer(node
);
2825 list_move_tail(&node
->list
, &rc
->backref_cache
.changed
);
2829 path
->lowest_level
= 0;
2830 BUG_ON(err
== -ENOSPC
);
2834 static int link_to_upper(struct btrfs_trans_handle
*trans
,
2835 struct reloc_control
*rc
,
2836 struct backref_node
*node
,
2837 struct btrfs_path
*path
)
2839 struct btrfs_key key
;
2841 btrfs_node_key_to_cpu(node
->eb
, &key
, 0);
2842 return do_relocation(trans
, rc
, node
, &key
, path
, 0);
2845 static int finish_pending_nodes(struct btrfs_trans_handle
*trans
,
2846 struct reloc_control
*rc
,
2847 struct btrfs_path
*path
, int err
)
2850 struct backref_cache
*cache
= &rc
->backref_cache
;
2851 struct backref_node
*node
;
2855 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
2856 while (!list_empty(&cache
->pending
[level
])) {
2857 node
= list_entry(cache
->pending
[level
].next
,
2858 struct backref_node
, list
);
2859 list_move_tail(&node
->list
, &list
);
2860 BUG_ON(!node
->pending
);
2863 ret
= link_to_upper(trans
, rc
, node
, path
);
2868 list_splice_init(&list
, &cache
->pending
[level
]);
2873 static void mark_block_processed(struct reloc_control
*rc
,
2874 u64 bytenr
, u32 blocksize
)
2876 set_extent_bits(&rc
->processed_blocks
, bytenr
, bytenr
+ blocksize
- 1,
2880 static void __mark_block_processed(struct reloc_control
*rc
,
2881 struct backref_node
*node
)
2884 if (node
->level
== 0 ||
2885 in_block_group(node
->bytenr
, rc
->block_group
)) {
2886 blocksize
= rc
->extent_root
->fs_info
->nodesize
;
2887 mark_block_processed(rc
, node
->bytenr
, blocksize
);
2889 node
->processed
= 1;
2893 * mark a block and all blocks directly/indirectly reference the block
2896 static void update_processed_blocks(struct reloc_control
*rc
,
2897 struct backref_node
*node
)
2899 struct backref_node
*next
= node
;
2900 struct backref_edge
*edge
;
2901 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2907 if (next
->processed
)
2910 __mark_block_processed(rc
, next
);
2912 if (list_empty(&next
->upper
))
2915 edge
= list_entry(next
->upper
.next
,
2916 struct backref_edge
, list
[LOWER
]);
2917 edges
[index
++] = edge
;
2918 next
= edge
->node
[UPPER
];
2920 next
= walk_down_backref(edges
, &index
);
2924 static int tree_block_processed(u64 bytenr
, struct reloc_control
*rc
)
2926 u32 blocksize
= rc
->extent_root
->fs_info
->nodesize
;
2928 if (test_range_bit(&rc
->processed_blocks
, bytenr
,
2929 bytenr
+ blocksize
- 1, EXTENT_DIRTY
, 1, NULL
))
2934 static int get_tree_block_key(struct btrfs_fs_info
*fs_info
,
2935 struct tree_block
*block
)
2937 struct extent_buffer
*eb
;
2939 BUG_ON(block
->key_ready
);
2940 eb
= read_tree_block(fs_info
, block
->bytenr
, block
->key
.offset
);
2943 } else if (!extent_buffer_uptodate(eb
)) {
2944 free_extent_buffer(eb
);
2947 WARN_ON(btrfs_header_level(eb
) != block
->level
);
2948 if (block
->level
== 0)
2949 btrfs_item_key_to_cpu(eb
, &block
->key
, 0);
2951 btrfs_node_key_to_cpu(eb
, &block
->key
, 0);
2952 free_extent_buffer(eb
);
2953 block
->key_ready
= 1;
2958 * helper function to relocate a tree block
2960 static int relocate_tree_block(struct btrfs_trans_handle
*trans
,
2961 struct reloc_control
*rc
,
2962 struct backref_node
*node
,
2963 struct btrfs_key
*key
,
2964 struct btrfs_path
*path
)
2966 struct btrfs_root
*root
;
2972 BUG_ON(node
->processed
);
2973 root
= select_one_root(node
);
2974 if (root
== ERR_PTR(-ENOENT
)) {
2975 update_processed_blocks(rc
, node
);
2979 if (!root
|| test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
)) {
2980 ret
= reserve_metadata_space(trans
, rc
, node
);
2986 if (test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
)) {
2987 BUG_ON(node
->new_bytenr
);
2988 BUG_ON(!list_empty(&node
->list
));
2989 btrfs_record_root_in_trans(trans
, root
);
2990 root
= root
->reloc_root
;
2991 node
->new_bytenr
= root
->node
->start
;
2993 list_add_tail(&node
->list
, &rc
->backref_cache
.changed
);
2995 path
->lowest_level
= node
->level
;
2996 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2997 btrfs_release_path(path
);
3002 update_processed_blocks(rc
, node
);
3004 ret
= do_relocation(trans
, rc
, node
, key
, path
, 1);
3007 if (ret
|| node
->level
== 0 || node
->cowonly
)
3008 remove_backref_node(&rc
->backref_cache
, node
);
3013 * relocate a list of blocks
3015 static noinline_for_stack
3016 int relocate_tree_blocks(struct btrfs_trans_handle
*trans
,
3017 struct reloc_control
*rc
, struct rb_root
*blocks
)
3019 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3020 struct backref_node
*node
;
3021 struct btrfs_path
*path
;
3022 struct tree_block
*block
;
3023 struct rb_node
*rb_node
;
3027 path
= btrfs_alloc_path();
3030 goto out_free_blocks
;
3033 rb_node
= rb_first(blocks
);
3035 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
3036 if (!block
->key_ready
)
3037 readahead_tree_block(fs_info
, block
->bytenr
);
3038 rb_node
= rb_next(rb_node
);
3041 rb_node
= rb_first(blocks
);
3043 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
3044 if (!block
->key_ready
) {
3045 err
= get_tree_block_key(fs_info
, block
);
3049 rb_node
= rb_next(rb_node
);
3052 rb_node
= rb_first(blocks
);
3054 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
3056 node
= build_backref_tree(rc
, &block
->key
,
3057 block
->level
, block
->bytenr
);
3059 err
= PTR_ERR(node
);
3063 ret
= relocate_tree_block(trans
, rc
, node
, &block
->key
,
3066 if (ret
!= -EAGAIN
|| rb_node
== rb_first(blocks
))
3070 rb_node
= rb_next(rb_node
);
3073 err
= finish_pending_nodes(trans
, rc
, path
, err
);
3076 btrfs_free_path(path
);
3078 free_block_list(blocks
);
3082 static noinline_for_stack
3083 int prealloc_file_extent_cluster(struct inode
*inode
,
3084 struct file_extent_cluster
*cluster
)
3089 u64 offset
= BTRFS_I(inode
)->index_cnt
;
3093 u64 prealloc_start
= cluster
->start
- offset
;
3094 u64 prealloc_end
= cluster
->end
- offset
;
3096 struct extent_changeset
*data_reserved
= NULL
;
3098 BUG_ON(cluster
->start
!= cluster
->boundary
[0]);
3101 ret
= btrfs_check_data_free_space(inode
, &data_reserved
, prealloc_start
,
3102 prealloc_end
+ 1 - prealloc_start
);
3106 cur_offset
= prealloc_start
;
3107 while (nr
< cluster
->nr
) {
3108 start
= cluster
->boundary
[nr
] - offset
;
3109 if (nr
+ 1 < cluster
->nr
)
3110 end
= cluster
->boundary
[nr
+ 1] - 1 - offset
;
3112 end
= cluster
->end
- offset
;
3114 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3115 num_bytes
= end
+ 1 - start
;
3116 if (cur_offset
< start
)
3117 btrfs_free_reserved_data_space(inode
, data_reserved
,
3118 cur_offset
, start
- cur_offset
);
3119 ret
= btrfs_prealloc_file_range(inode
, 0, start
,
3120 num_bytes
, num_bytes
,
3121 end
+ 1, &alloc_hint
);
3122 cur_offset
= end
+ 1;
3123 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3128 if (cur_offset
< prealloc_end
)
3129 btrfs_free_reserved_data_space(inode
, data_reserved
,
3130 cur_offset
, prealloc_end
+ 1 - cur_offset
);
3132 inode_unlock(inode
);
3133 extent_changeset_free(data_reserved
);
3137 static noinline_for_stack
3138 int setup_extent_mapping(struct inode
*inode
, u64 start
, u64 end
,
3141 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
3142 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
3143 struct extent_map
*em
;
3146 em
= alloc_extent_map();
3151 em
->len
= end
+ 1 - start
;
3152 em
->block_len
= em
->len
;
3153 em
->block_start
= block_start
;
3154 em
->bdev
= fs_info
->fs_devices
->latest_bdev
;
3155 set_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
3157 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3159 write_lock(&em_tree
->lock
);
3160 ret
= add_extent_mapping(em_tree
, em
, 0);
3161 write_unlock(&em_tree
->lock
);
3162 if (ret
!= -EEXIST
) {
3163 free_extent_map(em
);
3166 btrfs_drop_extent_cache(BTRFS_I(inode
), start
, end
, 0);
3168 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3172 static int relocate_file_extent_cluster(struct inode
*inode
,
3173 struct file_extent_cluster
*cluster
)
3175 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
3178 u64 offset
= BTRFS_I(inode
)->index_cnt
;
3179 unsigned long index
;
3180 unsigned long last_index
;
3182 struct file_ra_state
*ra
;
3183 gfp_t mask
= btrfs_alloc_write_mask(inode
->i_mapping
);
3190 ra
= kzalloc(sizeof(*ra
), GFP_NOFS
);
3194 ret
= prealloc_file_extent_cluster(inode
, cluster
);
3198 file_ra_state_init(ra
, inode
->i_mapping
);
3200 ret
= setup_extent_mapping(inode
, cluster
->start
- offset
,
3201 cluster
->end
- offset
, cluster
->start
);
3205 index
= (cluster
->start
- offset
) >> PAGE_SHIFT
;
3206 last_index
= (cluster
->end
- offset
) >> PAGE_SHIFT
;
3207 while (index
<= last_index
) {
3208 ret
= btrfs_delalloc_reserve_metadata(BTRFS_I(inode
),
3213 page
= find_lock_page(inode
->i_mapping
, index
);
3215 page_cache_sync_readahead(inode
->i_mapping
,
3217 last_index
+ 1 - index
);
3218 page
= find_or_create_page(inode
->i_mapping
, index
,
3221 btrfs_delalloc_release_metadata(BTRFS_I(inode
),
3228 if (PageReadahead(page
)) {
3229 page_cache_async_readahead(inode
->i_mapping
,
3230 ra
, NULL
, page
, index
,
3231 last_index
+ 1 - index
);
3234 if (!PageUptodate(page
)) {
3235 btrfs_readpage(NULL
, page
);
3237 if (!PageUptodate(page
)) {
3240 btrfs_delalloc_release_metadata(BTRFS_I(inode
),
3247 page_start
= page_offset(page
);
3248 page_end
= page_start
+ PAGE_SIZE
- 1;
3250 lock_extent(&BTRFS_I(inode
)->io_tree
, page_start
, page_end
);
3252 set_page_extent_mapped(page
);
3254 if (nr
< cluster
->nr
&&
3255 page_start
+ offset
== cluster
->boundary
[nr
]) {
3256 set_extent_bits(&BTRFS_I(inode
)->io_tree
,
3257 page_start
, page_end
,
3262 btrfs_set_extent_delalloc(inode
, page_start
, page_end
, NULL
, 0);
3263 set_page_dirty(page
);
3265 unlock_extent(&BTRFS_I(inode
)->io_tree
,
3266 page_start
, page_end
);
3271 balance_dirty_pages_ratelimited(inode
->i_mapping
);
3272 btrfs_throttle(fs_info
);
3274 WARN_ON(nr
!= cluster
->nr
);
3280 static noinline_for_stack
3281 int relocate_data_extent(struct inode
*inode
, struct btrfs_key
*extent_key
,
3282 struct file_extent_cluster
*cluster
)
3286 if (cluster
->nr
> 0 && extent_key
->objectid
!= cluster
->end
+ 1) {
3287 ret
= relocate_file_extent_cluster(inode
, cluster
);
3294 cluster
->start
= extent_key
->objectid
;
3296 BUG_ON(cluster
->nr
>= MAX_EXTENTS
);
3297 cluster
->end
= extent_key
->objectid
+ extent_key
->offset
- 1;
3298 cluster
->boundary
[cluster
->nr
] = extent_key
->objectid
;
3301 if (cluster
->nr
>= MAX_EXTENTS
) {
3302 ret
= relocate_file_extent_cluster(inode
, cluster
);
3310 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3311 static int get_ref_objectid_v0(struct reloc_control
*rc
,
3312 struct btrfs_path
*path
,
3313 struct btrfs_key
*extent_key
,
3314 u64
*ref_objectid
, int *path_change
)
3316 struct btrfs_key key
;
3317 struct extent_buffer
*leaf
;
3318 struct btrfs_extent_ref_v0
*ref0
;
3322 leaf
= path
->nodes
[0];
3323 slot
= path
->slots
[0];
3325 if (slot
>= btrfs_header_nritems(leaf
)) {
3326 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3330 leaf
= path
->nodes
[0];
3331 slot
= path
->slots
[0];
3335 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
3336 if (key
.objectid
!= extent_key
->objectid
)
3339 if (key
.type
!= BTRFS_EXTENT_REF_V0_KEY
) {
3343 ref0
= btrfs_item_ptr(leaf
, slot
,
3344 struct btrfs_extent_ref_v0
);
3345 *ref_objectid
= btrfs_ref_objectid_v0(leaf
, ref0
);
3353 * helper to add a tree block to the list.
3354 * the major work is getting the generation and level of the block
3356 static int add_tree_block(struct reloc_control
*rc
,
3357 struct btrfs_key
*extent_key
,
3358 struct btrfs_path
*path
,
3359 struct rb_root
*blocks
)
3361 struct extent_buffer
*eb
;
3362 struct btrfs_extent_item
*ei
;
3363 struct btrfs_tree_block_info
*bi
;
3364 struct tree_block
*block
;
3365 struct rb_node
*rb_node
;
3370 eb
= path
->nodes
[0];
3371 item_size
= btrfs_item_size_nr(eb
, path
->slots
[0]);
3373 if (extent_key
->type
== BTRFS_METADATA_ITEM_KEY
||
3374 item_size
>= sizeof(*ei
) + sizeof(*bi
)) {
3375 ei
= btrfs_item_ptr(eb
, path
->slots
[0],
3376 struct btrfs_extent_item
);
3377 if (extent_key
->type
== BTRFS_EXTENT_ITEM_KEY
) {
3378 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
3379 level
= btrfs_tree_block_level(eb
, bi
);
3381 level
= (int)extent_key
->offset
;
3383 generation
= btrfs_extent_generation(eb
, ei
);
3385 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3389 BUG_ON(item_size
!= sizeof(struct btrfs_extent_item_v0
));
3390 ret
= get_ref_objectid_v0(rc
, path
, extent_key
,
3394 BUG_ON(ref_owner
>= BTRFS_MAX_LEVEL
);
3395 level
= (int)ref_owner
;
3396 /* FIXME: get real generation */
3403 btrfs_release_path(path
);
3405 BUG_ON(level
== -1);
3407 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3411 block
->bytenr
= extent_key
->objectid
;
3412 block
->key
.objectid
= rc
->extent_root
->fs_info
->nodesize
;
3413 block
->key
.offset
= generation
;
3414 block
->level
= level
;
3415 block
->key_ready
= 0;
3417 rb_node
= tree_insert(blocks
, block
->bytenr
, &block
->rb_node
);
3419 backref_tree_panic(rb_node
, -EEXIST
, block
->bytenr
);
3425 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3427 static int __add_tree_block(struct reloc_control
*rc
,
3428 u64 bytenr
, u32 blocksize
,
3429 struct rb_root
*blocks
)
3431 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3432 struct btrfs_path
*path
;
3433 struct btrfs_key key
;
3435 bool skinny
= btrfs_fs_incompat(fs_info
, SKINNY_METADATA
);
3437 if (tree_block_processed(bytenr
, rc
))
3440 if (tree_search(blocks
, bytenr
))
3443 path
= btrfs_alloc_path();
3447 key
.objectid
= bytenr
;
3449 key
.type
= BTRFS_METADATA_ITEM_KEY
;
3450 key
.offset
= (u64
)-1;
3452 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3453 key
.offset
= blocksize
;
3456 path
->search_commit_root
= 1;
3457 path
->skip_locking
= 1;
3458 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
, 0, 0);
3462 if (ret
> 0 && skinny
) {
3463 if (path
->slots
[0]) {
3465 btrfs_item_key_to_cpu(path
->nodes
[0], &key
,
3467 if (key
.objectid
== bytenr
&&
3468 (key
.type
== BTRFS_METADATA_ITEM_KEY
||
3469 (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
3470 key
.offset
== blocksize
)))
3476 btrfs_release_path(path
);
3482 ret
= add_tree_block(rc
, &key
, path
, blocks
);
3484 btrfs_free_path(path
);
3489 * helper to check if the block use full backrefs for pointers in it
3491 static int block_use_full_backref(struct reloc_control
*rc
,
3492 struct extent_buffer
*eb
)
3497 if (btrfs_header_flag(eb
, BTRFS_HEADER_FLAG_RELOC
) ||
3498 btrfs_header_backref_rev(eb
) < BTRFS_MIXED_BACKREF_REV
)
3501 ret
= btrfs_lookup_extent_info(NULL
, rc
->extent_root
->fs_info
,
3502 eb
->start
, btrfs_header_level(eb
), 1,
3506 if (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
)
3513 static int delete_block_group_cache(struct btrfs_fs_info
*fs_info
,
3514 struct btrfs_block_group_cache
*block_group
,
3515 struct inode
*inode
,
3518 struct btrfs_key key
;
3519 struct btrfs_root
*root
= fs_info
->tree_root
;
3520 struct btrfs_trans_handle
*trans
;
3527 key
.type
= BTRFS_INODE_ITEM_KEY
;
3530 inode
= btrfs_iget(fs_info
->sb
, &key
, root
, NULL
);
3531 if (IS_ERR(inode
) || is_bad_inode(inode
)) {
3538 ret
= btrfs_check_trunc_cache_free_space(fs_info
,
3539 &fs_info
->global_block_rsv
);
3543 trans
= btrfs_join_transaction(root
);
3544 if (IS_ERR(trans
)) {
3545 ret
= PTR_ERR(trans
);
3549 ret
= btrfs_truncate_free_space_cache(trans
, block_group
, inode
);
3551 btrfs_end_transaction(trans
);
3552 btrfs_btree_balance_dirty(fs_info
);
3559 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3560 * this function scans fs tree to find blocks reference the data extent
3562 static int find_data_references(struct reloc_control
*rc
,
3563 struct btrfs_key
*extent_key
,
3564 struct extent_buffer
*leaf
,
3565 struct btrfs_extent_data_ref
*ref
,
3566 struct rb_root
*blocks
)
3568 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3569 struct btrfs_path
*path
;
3570 struct tree_block
*block
;
3571 struct btrfs_root
*root
;
3572 struct btrfs_file_extent_item
*fi
;
3573 struct rb_node
*rb_node
;
3574 struct btrfs_key key
;
3585 ref_root
= btrfs_extent_data_ref_root(leaf
, ref
);
3586 ref_objectid
= btrfs_extent_data_ref_objectid(leaf
, ref
);
3587 ref_offset
= btrfs_extent_data_ref_offset(leaf
, ref
);
3588 ref_count
= btrfs_extent_data_ref_count(leaf
, ref
);
3591 * This is an extent belonging to the free space cache, lets just delete
3592 * it and redo the search.
3594 if (ref_root
== BTRFS_ROOT_TREE_OBJECTID
) {
3595 ret
= delete_block_group_cache(fs_info
, rc
->block_group
,
3596 NULL
, ref_objectid
);
3602 path
= btrfs_alloc_path();
3605 path
->reada
= READA_FORWARD
;
3607 root
= read_fs_root(fs_info
, ref_root
);
3609 err
= PTR_ERR(root
);
3613 key
.objectid
= ref_objectid
;
3614 key
.type
= BTRFS_EXTENT_DATA_KEY
;
3615 if (ref_offset
> ((u64
)-1 << 32))
3618 key
.offset
= ref_offset
;
3620 path
->search_commit_root
= 1;
3621 path
->skip_locking
= 1;
3622 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
3628 leaf
= path
->nodes
[0];
3629 nritems
= btrfs_header_nritems(leaf
);
3631 * the references in tree blocks that use full backrefs
3632 * are not counted in
3634 if (block_use_full_backref(rc
, leaf
))
3638 rb_node
= tree_search(blocks
, leaf
->start
);
3643 path
->slots
[0] = nritems
;
3646 while (ref_count
> 0) {
3647 while (path
->slots
[0] >= nritems
) {
3648 ret
= btrfs_next_leaf(root
, path
);
3653 if (WARN_ON(ret
> 0))
3656 leaf
= path
->nodes
[0];
3657 nritems
= btrfs_header_nritems(leaf
);
3660 if (block_use_full_backref(rc
, leaf
))
3664 rb_node
= tree_search(blocks
, leaf
->start
);
3669 path
->slots
[0] = nritems
;
3673 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3674 if (WARN_ON(key
.objectid
!= ref_objectid
||
3675 key
.type
!= BTRFS_EXTENT_DATA_KEY
))
3678 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3679 struct btrfs_file_extent_item
);
3681 if (btrfs_file_extent_type(leaf
, fi
) ==
3682 BTRFS_FILE_EXTENT_INLINE
)
3685 if (btrfs_file_extent_disk_bytenr(leaf
, fi
) !=
3686 extent_key
->objectid
)
3689 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
3690 if (key
.offset
!= ref_offset
)
3698 if (!tree_block_processed(leaf
->start
, rc
)) {
3699 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3704 block
->bytenr
= leaf
->start
;
3705 btrfs_item_key_to_cpu(leaf
, &block
->key
, 0);
3707 block
->key_ready
= 1;
3708 rb_node
= tree_insert(blocks
, block
->bytenr
,
3711 backref_tree_panic(rb_node
, -EEXIST
,
3717 path
->slots
[0] = nritems
;
3723 btrfs_free_path(path
);
3728 * helper to find all tree blocks that reference a given data extent
3730 static noinline_for_stack
3731 int add_data_references(struct reloc_control
*rc
,
3732 struct btrfs_key
*extent_key
,
3733 struct btrfs_path
*path
,
3734 struct rb_root
*blocks
)
3736 struct btrfs_key key
;
3737 struct extent_buffer
*eb
;
3738 struct btrfs_extent_data_ref
*dref
;
3739 struct btrfs_extent_inline_ref
*iref
;
3742 u32 blocksize
= rc
->extent_root
->fs_info
->nodesize
;
3746 eb
= path
->nodes
[0];
3747 ptr
= btrfs_item_ptr_offset(eb
, path
->slots
[0]);
3748 end
= ptr
+ btrfs_item_size_nr(eb
, path
->slots
[0]);
3749 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3750 if (ptr
+ sizeof(struct btrfs_extent_item_v0
) == end
)
3754 ptr
+= sizeof(struct btrfs_extent_item
);
3757 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
3758 key
.type
= btrfs_extent_inline_ref_type(eb
, iref
);
3759 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3760 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
3761 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3763 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3764 dref
= (struct btrfs_extent_data_ref
*)(&iref
->offset
);
3765 ret
= find_data_references(rc
, extent_key
,
3774 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
3780 eb
= path
->nodes
[0];
3781 if (path
->slots
[0] >= btrfs_header_nritems(eb
)) {
3782 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3789 eb
= path
->nodes
[0];
3792 btrfs_item_key_to_cpu(eb
, &key
, path
->slots
[0]);
3793 if (key
.objectid
!= extent_key
->objectid
)
3796 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3797 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
||
3798 key
.type
== BTRFS_EXTENT_REF_V0_KEY
) {
3800 BUG_ON(key
.type
== BTRFS_EXTENT_REF_V0_KEY
);
3801 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3803 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3805 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3806 dref
= btrfs_item_ptr(eb
, path
->slots
[0],
3807 struct btrfs_extent_data_ref
);
3808 ret
= find_data_references(rc
, extent_key
,
3820 btrfs_release_path(path
);
3822 free_block_list(blocks
);
3827 * helper to find next unprocessed extent
3829 static noinline_for_stack
3830 int find_next_extent(struct reloc_control
*rc
, struct btrfs_path
*path
,
3831 struct btrfs_key
*extent_key
)
3833 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3834 struct btrfs_key key
;
3835 struct extent_buffer
*leaf
;
3836 u64 start
, end
, last
;
3839 last
= rc
->block_group
->key
.objectid
+ rc
->block_group
->key
.offset
;
3842 if (rc
->search_start
>= last
) {
3847 key
.objectid
= rc
->search_start
;
3848 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3851 path
->search_commit_root
= 1;
3852 path
->skip_locking
= 1;
3853 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
,
3858 leaf
= path
->nodes
[0];
3859 if (path
->slots
[0] >= btrfs_header_nritems(leaf
)) {
3860 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3863 leaf
= path
->nodes
[0];
3866 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3867 if (key
.objectid
>= last
) {
3872 if (key
.type
!= BTRFS_EXTENT_ITEM_KEY
&&
3873 key
.type
!= BTRFS_METADATA_ITEM_KEY
) {
3878 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
3879 key
.objectid
+ key
.offset
<= rc
->search_start
) {
3884 if (key
.type
== BTRFS_METADATA_ITEM_KEY
&&
3885 key
.objectid
+ fs_info
->nodesize
<=
3891 ret
= find_first_extent_bit(&rc
->processed_blocks
,
3892 key
.objectid
, &start
, &end
,
3893 EXTENT_DIRTY
, NULL
);
3895 if (ret
== 0 && start
<= key
.objectid
) {
3896 btrfs_release_path(path
);
3897 rc
->search_start
= end
+ 1;
3899 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
)
3900 rc
->search_start
= key
.objectid
+ key
.offset
;
3902 rc
->search_start
= key
.objectid
+
3904 memcpy(extent_key
, &key
, sizeof(key
));
3908 btrfs_release_path(path
);
3912 static void set_reloc_control(struct reloc_control
*rc
)
3914 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3916 mutex_lock(&fs_info
->reloc_mutex
);
3917 fs_info
->reloc_ctl
= rc
;
3918 mutex_unlock(&fs_info
->reloc_mutex
);
3921 static void unset_reloc_control(struct reloc_control
*rc
)
3923 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3925 mutex_lock(&fs_info
->reloc_mutex
);
3926 fs_info
->reloc_ctl
= NULL
;
3927 mutex_unlock(&fs_info
->reloc_mutex
);
3930 static int check_extent_flags(u64 flags
)
3932 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3933 (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3935 if (!(flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3936 !(flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3938 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3939 (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
))
3944 static noinline_for_stack
3945 int prepare_to_relocate(struct reloc_control
*rc
)
3947 struct btrfs_trans_handle
*trans
;
3950 rc
->block_rsv
= btrfs_alloc_block_rsv(rc
->extent_root
->fs_info
,
3951 BTRFS_BLOCK_RSV_TEMP
);
3955 memset(&rc
->cluster
, 0, sizeof(rc
->cluster
));
3956 rc
->search_start
= rc
->block_group
->key
.objectid
;
3957 rc
->extents_found
= 0;
3958 rc
->nodes_relocated
= 0;
3959 rc
->merging_rsv_size
= 0;
3960 rc
->reserved_bytes
= 0;
3961 rc
->block_rsv
->size
= rc
->extent_root
->fs_info
->nodesize
*
3962 RELOCATION_RESERVED_NODES
;
3963 ret
= btrfs_block_rsv_refill(rc
->extent_root
,
3964 rc
->block_rsv
, rc
->block_rsv
->size
,
3965 BTRFS_RESERVE_FLUSH_ALL
);
3969 rc
->create_reloc_tree
= 1;
3970 set_reloc_control(rc
);
3972 trans
= btrfs_join_transaction(rc
->extent_root
);
3973 if (IS_ERR(trans
)) {
3974 unset_reloc_control(rc
);
3976 * extent tree is not a ref_cow tree and has no reloc_root to
3977 * cleanup. And callers are responsible to free the above
3980 return PTR_ERR(trans
);
3982 btrfs_commit_transaction(trans
);
3986 static noinline_for_stack
int relocate_block_group(struct reloc_control
*rc
)
3988 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3989 struct rb_root blocks
= RB_ROOT
;
3990 struct btrfs_key key
;
3991 struct btrfs_trans_handle
*trans
= NULL
;
3992 struct btrfs_path
*path
;
3993 struct btrfs_extent_item
*ei
;
4000 path
= btrfs_alloc_path();
4003 path
->reada
= READA_FORWARD
;
4005 ret
= prepare_to_relocate(rc
);
4012 rc
->reserved_bytes
= 0;
4013 ret
= btrfs_block_rsv_refill(rc
->extent_root
,
4014 rc
->block_rsv
, rc
->block_rsv
->size
,
4015 BTRFS_RESERVE_FLUSH_ALL
);
4021 trans
= btrfs_start_transaction(rc
->extent_root
, 0);
4022 if (IS_ERR(trans
)) {
4023 err
= PTR_ERR(trans
);
4028 if (update_backref_cache(trans
, &rc
->backref_cache
)) {
4029 btrfs_end_transaction(trans
);
4033 ret
= find_next_extent(rc
, path
, &key
);
4039 rc
->extents_found
++;
4041 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
4042 struct btrfs_extent_item
);
4043 item_size
= btrfs_item_size_nr(path
->nodes
[0], path
->slots
[0]);
4044 if (item_size
>= sizeof(*ei
)) {
4045 flags
= btrfs_extent_flags(path
->nodes
[0], ei
);
4046 ret
= check_extent_flags(flags
);
4050 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
4052 int path_change
= 0;
4055 sizeof(struct btrfs_extent_item_v0
));
4056 ret
= get_ref_objectid_v0(rc
, path
, &key
, &ref_owner
,
4062 if (ref_owner
< BTRFS_FIRST_FREE_OBJECTID
)
4063 flags
= BTRFS_EXTENT_FLAG_TREE_BLOCK
;
4065 flags
= BTRFS_EXTENT_FLAG_DATA
;
4068 btrfs_release_path(path
);
4070 path
->search_commit_root
= 1;
4071 path
->skip_locking
= 1;
4072 ret
= btrfs_search_slot(NULL
, rc
->extent_root
,
4085 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
4086 ret
= add_tree_block(rc
, &key
, path
, &blocks
);
4087 } else if (rc
->stage
== UPDATE_DATA_PTRS
&&
4088 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
4089 ret
= add_data_references(rc
, &key
, path
, &blocks
);
4091 btrfs_release_path(path
);
4099 if (!RB_EMPTY_ROOT(&blocks
)) {
4100 ret
= relocate_tree_blocks(trans
, rc
, &blocks
);
4103 * if we fail to relocate tree blocks, force to update
4104 * backref cache when committing transaction.
4106 rc
->backref_cache
.last_trans
= trans
->transid
- 1;
4108 if (ret
!= -EAGAIN
) {
4112 rc
->extents_found
--;
4113 rc
->search_start
= key
.objectid
;
4117 btrfs_end_transaction_throttle(trans
);
4118 btrfs_btree_balance_dirty(fs_info
);
4121 if (rc
->stage
== MOVE_DATA_EXTENTS
&&
4122 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
4123 rc
->found_file_extent
= 1;
4124 ret
= relocate_data_extent(rc
->data_inode
,
4125 &key
, &rc
->cluster
);
4132 if (trans
&& progress
&& err
== -ENOSPC
) {
4133 ret
= btrfs_force_chunk_alloc(trans
, fs_info
,
4134 rc
->block_group
->flags
);
4142 btrfs_release_path(path
);
4143 clear_extent_bits(&rc
->processed_blocks
, 0, (u64
)-1, EXTENT_DIRTY
);
4146 btrfs_end_transaction_throttle(trans
);
4147 btrfs_btree_balance_dirty(fs_info
);
4151 ret
= relocate_file_extent_cluster(rc
->data_inode
,
4157 rc
->create_reloc_tree
= 0;
4158 set_reloc_control(rc
);
4160 backref_cache_cleanup(&rc
->backref_cache
);
4161 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
, (u64
)-1);
4163 err
= prepare_to_merge(rc
, err
);
4165 merge_reloc_roots(rc
);
4167 rc
->merge_reloc_tree
= 0;
4168 unset_reloc_control(rc
);
4169 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
, (u64
)-1);
4171 /* get rid of pinned extents */
4172 trans
= btrfs_join_transaction(rc
->extent_root
);
4173 if (IS_ERR(trans
)) {
4174 err
= PTR_ERR(trans
);
4177 btrfs_commit_transaction(trans
);
4179 btrfs_free_block_rsv(fs_info
, rc
->block_rsv
);
4180 btrfs_free_path(path
);
4184 static int __insert_orphan_inode(struct btrfs_trans_handle
*trans
,
4185 struct btrfs_root
*root
, u64 objectid
)
4187 struct btrfs_path
*path
;
4188 struct btrfs_inode_item
*item
;
4189 struct extent_buffer
*leaf
;
4192 path
= btrfs_alloc_path();
4196 ret
= btrfs_insert_empty_inode(trans
, root
, path
, objectid
);
4200 leaf
= path
->nodes
[0];
4201 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_inode_item
);
4202 memzero_extent_buffer(leaf
, (unsigned long)item
, sizeof(*item
));
4203 btrfs_set_inode_generation(leaf
, item
, 1);
4204 btrfs_set_inode_size(leaf
, item
, 0);
4205 btrfs_set_inode_mode(leaf
, item
, S_IFREG
| 0600);
4206 btrfs_set_inode_flags(leaf
, item
, BTRFS_INODE_NOCOMPRESS
|
4207 BTRFS_INODE_PREALLOC
);
4208 btrfs_mark_buffer_dirty(leaf
);
4210 btrfs_free_path(path
);
4215 * helper to create inode for data relocation.
4216 * the inode is in data relocation tree and its link count is 0
4218 static noinline_for_stack
4219 struct inode
*create_reloc_inode(struct btrfs_fs_info
*fs_info
,
4220 struct btrfs_block_group_cache
*group
)
4222 struct inode
*inode
= NULL
;
4223 struct btrfs_trans_handle
*trans
;
4224 struct btrfs_root
*root
;
4225 struct btrfs_key key
;
4229 root
= read_fs_root(fs_info
, BTRFS_DATA_RELOC_TREE_OBJECTID
);
4231 return ERR_CAST(root
);
4233 trans
= btrfs_start_transaction(root
, 6);
4235 return ERR_CAST(trans
);
4237 err
= btrfs_find_free_objectid(root
, &objectid
);
4241 err
= __insert_orphan_inode(trans
, root
, objectid
);
4244 key
.objectid
= objectid
;
4245 key
.type
= BTRFS_INODE_ITEM_KEY
;
4247 inode
= btrfs_iget(fs_info
->sb
, &key
, root
, NULL
);
4248 BUG_ON(IS_ERR(inode
) || is_bad_inode(inode
));
4249 BTRFS_I(inode
)->index_cnt
= group
->key
.objectid
;
4251 err
= btrfs_orphan_add(trans
, BTRFS_I(inode
));
4253 btrfs_end_transaction(trans
);
4254 btrfs_btree_balance_dirty(fs_info
);
4258 inode
= ERR_PTR(err
);
4263 static struct reloc_control
*alloc_reloc_control(struct btrfs_fs_info
*fs_info
)
4265 struct reloc_control
*rc
;
4267 rc
= kzalloc(sizeof(*rc
), GFP_NOFS
);
4271 INIT_LIST_HEAD(&rc
->reloc_roots
);
4272 backref_cache_init(&rc
->backref_cache
);
4273 mapping_tree_init(&rc
->reloc_root_tree
);
4274 extent_io_tree_init(&rc
->processed_blocks
, NULL
);
4279 * Print the block group being relocated
4281 static void describe_relocation(struct btrfs_fs_info
*fs_info
,
4282 struct btrfs_block_group_cache
*block_group
)
4284 char buf
[128]; /* prefixed by a '|' that'll be dropped */
4285 u64 flags
= block_group
->flags
;
4287 /* Shouldn't happen */
4289 strcpy(buf
, "|NONE");
4293 #define DESCRIBE_FLAG(f, d) \
4294 if (flags & BTRFS_BLOCK_GROUP_##f) { \
4295 bp += snprintf(bp, buf - bp + sizeof(buf), "|%s", d); \
4296 flags &= ~BTRFS_BLOCK_GROUP_##f; \
4298 DESCRIBE_FLAG(DATA
, "data");
4299 DESCRIBE_FLAG(SYSTEM
, "system");
4300 DESCRIBE_FLAG(METADATA
, "metadata");
4301 DESCRIBE_FLAG(RAID0
, "raid0");
4302 DESCRIBE_FLAG(RAID1
, "raid1");
4303 DESCRIBE_FLAG(DUP
, "dup");
4304 DESCRIBE_FLAG(RAID10
, "raid10");
4305 DESCRIBE_FLAG(RAID5
, "raid5");
4306 DESCRIBE_FLAG(RAID6
, "raid6");
4308 snprintf(buf
, buf
- bp
+ sizeof(buf
), "|0x%llx", flags
);
4309 #undef DESCRIBE_FLAG
4313 "relocating block group %llu flags %s",
4314 block_group
->key
.objectid
, buf
+ 1);
4318 * function to relocate all extents in a block group.
4320 int btrfs_relocate_block_group(struct btrfs_fs_info
*fs_info
, u64 group_start
)
4322 struct btrfs_root
*extent_root
= fs_info
->extent_root
;
4323 struct reloc_control
*rc
;
4324 struct inode
*inode
;
4325 struct btrfs_path
*path
;
4330 rc
= alloc_reloc_control(fs_info
);
4334 rc
->extent_root
= extent_root
;
4336 rc
->block_group
= btrfs_lookup_block_group(fs_info
, group_start
);
4337 BUG_ON(!rc
->block_group
);
4339 ret
= btrfs_inc_block_group_ro(fs_info
, rc
->block_group
);
4346 path
= btrfs_alloc_path();
4352 inode
= lookup_free_space_inode(fs_info
, rc
->block_group
, path
);
4353 btrfs_free_path(path
);
4356 ret
= delete_block_group_cache(fs_info
, rc
->block_group
, inode
, 0);
4358 ret
= PTR_ERR(inode
);
4360 if (ret
&& ret
!= -ENOENT
) {
4365 rc
->data_inode
= create_reloc_inode(fs_info
, rc
->block_group
);
4366 if (IS_ERR(rc
->data_inode
)) {
4367 err
= PTR_ERR(rc
->data_inode
);
4368 rc
->data_inode
= NULL
;
4372 describe_relocation(fs_info
, rc
->block_group
);
4374 btrfs_wait_block_group_reservations(rc
->block_group
);
4375 btrfs_wait_nocow_writers(rc
->block_group
);
4376 btrfs_wait_ordered_roots(fs_info
, U64_MAX
,
4377 rc
->block_group
->key
.objectid
,
4378 rc
->block_group
->key
.offset
);
4381 mutex_lock(&fs_info
->cleaner_mutex
);
4382 ret
= relocate_block_group(rc
);
4383 mutex_unlock(&fs_info
->cleaner_mutex
);
4389 if (rc
->extents_found
== 0)
4392 btrfs_info(fs_info
, "found %llu extents", rc
->extents_found
);
4394 if (rc
->stage
== MOVE_DATA_EXTENTS
&& rc
->found_file_extent
) {
4395 ret
= btrfs_wait_ordered_range(rc
->data_inode
, 0,
4401 invalidate_mapping_pages(rc
->data_inode
->i_mapping
,
4403 rc
->stage
= UPDATE_DATA_PTRS
;
4407 WARN_ON(rc
->block_group
->pinned
> 0);
4408 WARN_ON(rc
->block_group
->reserved
> 0);
4409 WARN_ON(btrfs_block_group_used(&rc
->block_group
->item
) > 0);
4412 btrfs_dec_block_group_ro(rc
->block_group
);
4413 iput(rc
->data_inode
);
4414 btrfs_put_block_group(rc
->block_group
);
4419 static noinline_for_stack
int mark_garbage_root(struct btrfs_root
*root
)
4421 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
4422 struct btrfs_trans_handle
*trans
;
4425 trans
= btrfs_start_transaction(fs_info
->tree_root
, 0);
4427 return PTR_ERR(trans
);
4429 memset(&root
->root_item
.drop_progress
, 0,
4430 sizeof(root
->root_item
.drop_progress
));
4431 root
->root_item
.drop_level
= 0;
4432 btrfs_set_root_refs(&root
->root_item
, 0);
4433 ret
= btrfs_update_root(trans
, fs_info
->tree_root
,
4434 &root
->root_key
, &root
->root_item
);
4436 err
= btrfs_end_transaction(trans
);
4443 * recover relocation interrupted by system crash.
4445 * this function resumes merging reloc trees with corresponding fs trees.
4446 * this is important for keeping the sharing of tree blocks
4448 int btrfs_recover_relocation(struct btrfs_root
*root
)
4450 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
4451 LIST_HEAD(reloc_roots
);
4452 struct btrfs_key key
;
4453 struct btrfs_root
*fs_root
;
4454 struct btrfs_root
*reloc_root
;
4455 struct btrfs_path
*path
;
4456 struct extent_buffer
*leaf
;
4457 struct reloc_control
*rc
= NULL
;
4458 struct btrfs_trans_handle
*trans
;
4462 path
= btrfs_alloc_path();
4465 path
->reada
= READA_BACK
;
4467 key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
4468 key
.type
= BTRFS_ROOT_ITEM_KEY
;
4469 key
.offset
= (u64
)-1;
4472 ret
= btrfs_search_slot(NULL
, fs_info
->tree_root
, &key
,
4479 if (path
->slots
[0] == 0)
4483 leaf
= path
->nodes
[0];
4484 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
4485 btrfs_release_path(path
);
4487 if (key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
||
4488 key
.type
!= BTRFS_ROOT_ITEM_KEY
)
4491 reloc_root
= btrfs_read_fs_root(root
, &key
);
4492 if (IS_ERR(reloc_root
)) {
4493 err
= PTR_ERR(reloc_root
);
4497 list_add(&reloc_root
->root_list
, &reloc_roots
);
4499 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
4500 fs_root
= read_fs_root(fs_info
,
4501 reloc_root
->root_key
.offset
);
4502 if (IS_ERR(fs_root
)) {
4503 ret
= PTR_ERR(fs_root
);
4504 if (ret
!= -ENOENT
) {
4508 ret
= mark_garbage_root(reloc_root
);
4516 if (key
.offset
== 0)
4521 btrfs_release_path(path
);
4523 if (list_empty(&reloc_roots
))
4526 rc
= alloc_reloc_control(fs_info
);
4532 rc
->extent_root
= fs_info
->extent_root
;
4534 set_reloc_control(rc
);
4536 trans
= btrfs_join_transaction(rc
->extent_root
);
4537 if (IS_ERR(trans
)) {
4538 unset_reloc_control(rc
);
4539 err
= PTR_ERR(trans
);
4543 rc
->merge_reloc_tree
= 1;
4545 while (!list_empty(&reloc_roots
)) {
4546 reloc_root
= list_entry(reloc_roots
.next
,
4547 struct btrfs_root
, root_list
);
4548 list_del(&reloc_root
->root_list
);
4550 if (btrfs_root_refs(&reloc_root
->root_item
) == 0) {
4551 list_add_tail(&reloc_root
->root_list
,
4556 fs_root
= read_fs_root(fs_info
, reloc_root
->root_key
.offset
);
4557 if (IS_ERR(fs_root
)) {
4558 err
= PTR_ERR(fs_root
);
4562 err
= __add_reloc_root(reloc_root
);
4563 BUG_ON(err
< 0); /* -ENOMEM or logic error */
4564 fs_root
->reloc_root
= reloc_root
;
4567 err
= btrfs_commit_transaction(trans
);
4571 merge_reloc_roots(rc
);
4573 unset_reloc_control(rc
);
4575 trans
= btrfs_join_transaction(rc
->extent_root
);
4576 if (IS_ERR(trans
)) {
4577 err
= PTR_ERR(trans
);
4580 err
= btrfs_commit_transaction(trans
);
4584 if (!list_empty(&reloc_roots
))
4585 free_reloc_roots(&reloc_roots
);
4587 btrfs_free_path(path
);
4590 /* cleanup orphan inode in data relocation tree */
4591 fs_root
= read_fs_root(fs_info
, BTRFS_DATA_RELOC_TREE_OBJECTID
);
4592 if (IS_ERR(fs_root
))
4593 err
= PTR_ERR(fs_root
);
4595 err
= btrfs_orphan_cleanup(fs_root
);
4601 * helper to add ordered checksum for data relocation.
4603 * cloning checksum properly handles the nodatasum extents.
4604 * it also saves CPU time to re-calculate the checksum.
4606 int btrfs_reloc_clone_csums(struct inode
*inode
, u64 file_pos
, u64 len
)
4608 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
4609 struct btrfs_ordered_sum
*sums
;
4610 struct btrfs_ordered_extent
*ordered
;
4616 ordered
= btrfs_lookup_ordered_extent(inode
, file_pos
);
4617 BUG_ON(ordered
->file_offset
!= file_pos
|| ordered
->len
!= len
);
4619 disk_bytenr
= file_pos
+ BTRFS_I(inode
)->index_cnt
;
4620 ret
= btrfs_lookup_csums_range(fs_info
->csum_root
, disk_bytenr
,
4621 disk_bytenr
+ len
- 1, &list
, 0);
4625 while (!list_empty(&list
)) {
4626 sums
= list_entry(list
.next
, struct btrfs_ordered_sum
, list
);
4627 list_del_init(&sums
->list
);
4630 * We need to offset the new_bytenr based on where the csum is.
4631 * We need to do this because we will read in entire prealloc
4632 * extents but we may have written to say the middle of the
4633 * prealloc extent, so we need to make sure the csum goes with
4634 * the right disk offset.
4636 * We can do this because the data reloc inode refers strictly
4637 * to the on disk bytes, so we don't have to worry about
4638 * disk_len vs real len like with real inodes since it's all
4641 new_bytenr
= ordered
->start
+ (sums
->bytenr
- disk_bytenr
);
4642 sums
->bytenr
= new_bytenr
;
4644 btrfs_add_ordered_sum(inode
, ordered
, sums
);
4647 btrfs_put_ordered_extent(ordered
);
4651 int btrfs_reloc_cow_block(struct btrfs_trans_handle
*trans
,
4652 struct btrfs_root
*root
, struct extent_buffer
*buf
,
4653 struct extent_buffer
*cow
)
4655 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
4656 struct reloc_control
*rc
;
4657 struct backref_node
*node
;
4662 rc
= fs_info
->reloc_ctl
;
4666 BUG_ON(rc
->stage
== UPDATE_DATA_PTRS
&&
4667 root
->root_key
.objectid
== BTRFS_DATA_RELOC_TREE_OBJECTID
);
4669 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
4670 if (buf
== root
->node
)
4671 __update_reloc_root(root
, cow
->start
);
4674 level
= btrfs_header_level(buf
);
4675 if (btrfs_header_generation(buf
) <=
4676 btrfs_root_last_snapshot(&root
->root_item
))
4679 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
&&
4680 rc
->create_reloc_tree
) {
4681 WARN_ON(!first_cow
&& level
== 0);
4683 node
= rc
->backref_cache
.path
[level
];
4684 BUG_ON(node
->bytenr
!= buf
->start
&&
4685 node
->new_bytenr
!= buf
->start
);
4687 drop_node_buffer(node
);
4688 extent_buffer_get(cow
);
4690 node
->new_bytenr
= cow
->start
;
4692 if (!node
->pending
) {
4693 list_move_tail(&node
->list
,
4694 &rc
->backref_cache
.pending
[level
]);
4699 __mark_block_processed(rc
, node
);
4701 if (first_cow
&& level
> 0)
4702 rc
->nodes_relocated
+= buf
->len
;
4705 if (level
== 0 && first_cow
&& rc
->stage
== UPDATE_DATA_PTRS
)
4706 ret
= replace_file_extents(trans
, rc
, root
, cow
);
4711 * called before creating snapshot. it calculates metadata reservation
4712 * required for relocating tree blocks in the snapshot
4714 void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot
*pending
,
4715 u64
*bytes_to_reserve
)
4717 struct btrfs_root
*root
;
4718 struct reloc_control
*rc
;
4720 root
= pending
->root
;
4721 if (!root
->reloc_root
)
4724 rc
= root
->fs_info
->reloc_ctl
;
4725 if (!rc
->merge_reloc_tree
)
4728 root
= root
->reloc_root
;
4729 BUG_ON(btrfs_root_refs(&root
->root_item
) == 0);
4731 * relocation is in the stage of merging trees. the space
4732 * used by merging a reloc tree is twice the size of
4733 * relocated tree nodes in the worst case. half for cowing
4734 * the reloc tree, half for cowing the fs tree. the space
4735 * used by cowing the reloc tree will be freed after the
4736 * tree is dropped. if we create snapshot, cowing the fs
4737 * tree may use more space than it frees. so we need
4738 * reserve extra space.
4740 *bytes_to_reserve
+= rc
->nodes_relocated
;
4744 * called after snapshot is created. migrate block reservation
4745 * and create reloc root for the newly created snapshot
4747 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle
*trans
,
4748 struct btrfs_pending_snapshot
*pending
)
4750 struct btrfs_root
*root
= pending
->root
;
4751 struct btrfs_root
*reloc_root
;
4752 struct btrfs_root
*new_root
;
4753 struct reloc_control
*rc
;
4756 if (!root
->reloc_root
)
4759 rc
= root
->fs_info
->reloc_ctl
;
4760 rc
->merging_rsv_size
+= rc
->nodes_relocated
;
4762 if (rc
->merge_reloc_tree
) {
4763 ret
= btrfs_block_rsv_migrate(&pending
->block_rsv
,
4765 rc
->nodes_relocated
, 1);
4770 new_root
= pending
->snap
;
4771 reloc_root
= create_reloc_root(trans
, root
->reloc_root
,
4772 new_root
->root_key
.objectid
);
4773 if (IS_ERR(reloc_root
))
4774 return PTR_ERR(reloc_root
);
4776 ret
= __add_reloc_root(reloc_root
);
4778 new_root
->reloc_root
= reloc_root
;
4780 if (rc
->create_reloc_tree
)
4781 ret
= clone_backref_node(trans
, rc
, root
, reloc_root
);