1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2009 Oracle. All rights reserved.
6 #include <linux/sched.h>
7 #include <linux/pagemap.h>
8 #include <linux/writeback.h>
9 #include <linux/blkdev.h>
10 #include <linux/rbtree.h>
11 #include <linux/slab.h>
14 #include "transaction.h"
17 #include "btrfs_inode.h"
18 #include "async-thread.h"
19 #include "free-space-cache.h"
20 #include "inode-map.h"
22 #include "print-tree.h"
23 #include "delalloc-space.h"
24 #include "block-group.h"
27 * backref_node, mapping_node and tree_block start with this
30 struct rb_node rb_node
;
35 * present a tree block in the backref cache
38 struct rb_node rb_node
;
42 /* objectid of tree block owner, can be not uptodate */
44 /* link to pending, changed or detached list */
45 struct list_head list
;
46 /* list of upper level blocks reference this block */
47 struct list_head upper
;
48 /* list of child blocks in the cache */
49 struct list_head lower
;
50 /* NULL if this node is not tree root */
51 struct btrfs_root
*root
;
52 /* extent buffer got by COW the block */
53 struct extent_buffer
*eb
;
54 /* level of tree block */
56 /* is the block in non-reference counted tree */
57 unsigned int cowonly
:1;
58 /* 1 if no child node in the cache */
59 unsigned int lowest
:1;
60 /* is the extent buffer locked */
61 unsigned int locked
:1;
62 /* has the block been processed */
63 unsigned int processed
:1;
64 /* have backrefs of this block been checked */
65 unsigned int checked
:1;
67 * 1 if corresponding block has been cowed but some upper
68 * level block pointers may not point to the new location
70 unsigned int pending
:1;
72 * 1 if the backref node isn't connected to any other
75 unsigned int detached
:1;
79 * present a block pointer in the backref cache
82 struct list_head list
[2];
83 struct backref_node
*node
[2];
88 #define RELOCATION_RESERVED_NODES 256
90 struct backref_cache
{
91 /* red black tree of all backref nodes in the cache */
92 struct rb_root rb_root
;
93 /* for passing backref nodes to btrfs_reloc_cow_block */
94 struct backref_node
*path
[BTRFS_MAX_LEVEL
];
96 * list of blocks that have been cowed but some block
97 * pointers in upper level blocks may not reflect the
100 struct list_head pending
[BTRFS_MAX_LEVEL
];
101 /* list of backref nodes with no child node */
102 struct list_head leaves
;
103 /* list of blocks that have been cowed in current transaction */
104 struct list_head changed
;
105 /* list of detached backref node. */
106 struct list_head detached
;
115 * map address of tree root to tree
117 struct mapping_node
{
118 struct rb_node rb_node
;
123 struct mapping_tree
{
124 struct rb_root rb_root
;
129 * present a tree block to process
132 struct rb_node rb_node
;
134 struct btrfs_key key
;
135 unsigned int level
:8;
136 unsigned int key_ready
:1;
139 #define MAX_EXTENTS 128
141 struct file_extent_cluster
{
144 u64 boundary
[MAX_EXTENTS
];
148 struct reloc_control
{
149 /* block group to relocate */
150 struct btrfs_block_group
*block_group
;
152 struct btrfs_root
*extent_root
;
153 /* inode for moving data */
154 struct inode
*data_inode
;
156 struct btrfs_block_rsv
*block_rsv
;
158 struct backref_cache backref_cache
;
160 struct file_extent_cluster cluster
;
161 /* tree blocks have been processed */
162 struct extent_io_tree processed_blocks
;
163 /* map start of tree root to corresponding reloc tree */
164 struct mapping_tree reloc_root_tree
;
165 /* list of reloc trees */
166 struct list_head reloc_roots
;
167 /* list of subvolume trees that get relocated */
168 struct list_head dirty_subvol_roots
;
169 /* size of metadata reservation for merging reloc trees */
170 u64 merging_rsv_size
;
171 /* size of relocated tree nodes */
173 /* reserved size for block group relocation*/
179 unsigned int stage
:8;
180 unsigned int create_reloc_tree
:1;
181 unsigned int merge_reloc_tree
:1;
182 unsigned int found_file_extent
:1;
185 /* stages of data relocation */
186 #define MOVE_DATA_EXTENTS 0
187 #define UPDATE_DATA_PTRS 1
189 static void remove_backref_node(struct backref_cache
*cache
,
190 struct backref_node
*node
);
191 static void __mark_block_processed(struct reloc_control
*rc
,
192 struct backref_node
*node
);
194 static void mapping_tree_init(struct mapping_tree
*tree
)
196 tree
->rb_root
= RB_ROOT
;
197 spin_lock_init(&tree
->lock
);
200 static void backref_cache_init(struct backref_cache
*cache
)
203 cache
->rb_root
= RB_ROOT
;
204 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++)
205 INIT_LIST_HEAD(&cache
->pending
[i
]);
206 INIT_LIST_HEAD(&cache
->changed
);
207 INIT_LIST_HEAD(&cache
->detached
);
208 INIT_LIST_HEAD(&cache
->leaves
);
211 static void backref_cache_cleanup(struct backref_cache
*cache
)
213 struct backref_node
*node
;
216 while (!list_empty(&cache
->detached
)) {
217 node
= list_entry(cache
->detached
.next
,
218 struct backref_node
, list
);
219 remove_backref_node(cache
, node
);
222 while (!list_empty(&cache
->leaves
)) {
223 node
= list_entry(cache
->leaves
.next
,
224 struct backref_node
, lower
);
225 remove_backref_node(cache
, node
);
228 cache
->last_trans
= 0;
230 for (i
= 0; i
< BTRFS_MAX_LEVEL
; i
++)
231 ASSERT(list_empty(&cache
->pending
[i
]));
232 ASSERT(list_empty(&cache
->changed
));
233 ASSERT(list_empty(&cache
->detached
));
234 ASSERT(RB_EMPTY_ROOT(&cache
->rb_root
));
235 ASSERT(!cache
->nr_nodes
);
236 ASSERT(!cache
->nr_edges
);
239 static struct backref_node
*alloc_backref_node(struct backref_cache
*cache
)
241 struct backref_node
*node
;
243 node
= kzalloc(sizeof(*node
), GFP_NOFS
);
245 INIT_LIST_HEAD(&node
->list
);
246 INIT_LIST_HEAD(&node
->upper
);
247 INIT_LIST_HEAD(&node
->lower
);
248 RB_CLEAR_NODE(&node
->rb_node
);
254 static void free_backref_node(struct backref_cache
*cache
,
255 struct backref_node
*node
)
263 static struct backref_edge
*alloc_backref_edge(struct backref_cache
*cache
)
265 struct backref_edge
*edge
;
267 edge
= kzalloc(sizeof(*edge
), GFP_NOFS
);
273 static void free_backref_edge(struct backref_cache
*cache
,
274 struct backref_edge
*edge
)
282 static struct rb_node
*tree_insert(struct rb_root
*root
, u64 bytenr
,
283 struct rb_node
*node
)
285 struct rb_node
**p
= &root
->rb_node
;
286 struct rb_node
*parent
= NULL
;
287 struct tree_entry
*entry
;
291 entry
= rb_entry(parent
, struct tree_entry
, rb_node
);
293 if (bytenr
< entry
->bytenr
)
295 else if (bytenr
> entry
->bytenr
)
301 rb_link_node(node
, parent
, p
);
302 rb_insert_color(node
, root
);
306 static struct rb_node
*tree_search(struct rb_root
*root
, u64 bytenr
)
308 struct rb_node
*n
= root
->rb_node
;
309 struct tree_entry
*entry
;
312 entry
= rb_entry(n
, struct tree_entry
, rb_node
);
314 if (bytenr
< entry
->bytenr
)
316 else if (bytenr
> entry
->bytenr
)
324 static void backref_tree_panic(struct rb_node
*rb_node
, int errno
, u64 bytenr
)
327 struct btrfs_fs_info
*fs_info
= NULL
;
328 struct backref_node
*bnode
= rb_entry(rb_node
, struct backref_node
,
331 fs_info
= bnode
->root
->fs_info
;
332 btrfs_panic(fs_info
, errno
,
333 "Inconsistency in backref cache found at offset %llu",
338 * walk up backref nodes until reach node presents tree root
340 static struct backref_node
*walk_up_backref(struct backref_node
*node
,
341 struct backref_edge
*edges
[],
344 struct backref_edge
*edge
;
347 while (!list_empty(&node
->upper
)) {
348 edge
= list_entry(node
->upper
.next
,
349 struct backref_edge
, list
[LOWER
]);
351 node
= edge
->node
[UPPER
];
353 BUG_ON(node
->detached
);
359 * walk down backref nodes to find start of next reference path
361 static struct backref_node
*walk_down_backref(struct backref_edge
*edges
[],
364 struct backref_edge
*edge
;
365 struct backref_node
*lower
;
369 edge
= edges
[idx
- 1];
370 lower
= edge
->node
[LOWER
];
371 if (list_is_last(&edge
->list
[LOWER
], &lower
->upper
)) {
375 edge
= list_entry(edge
->list
[LOWER
].next
,
376 struct backref_edge
, list
[LOWER
]);
377 edges
[idx
- 1] = edge
;
379 return edge
->node
[UPPER
];
385 static void unlock_node_buffer(struct backref_node
*node
)
388 btrfs_tree_unlock(node
->eb
);
393 static void drop_node_buffer(struct backref_node
*node
)
396 unlock_node_buffer(node
);
397 free_extent_buffer(node
->eb
);
402 static void drop_backref_node(struct backref_cache
*tree
,
403 struct backref_node
*node
)
405 BUG_ON(!list_empty(&node
->upper
));
407 drop_node_buffer(node
);
408 list_del(&node
->list
);
409 list_del(&node
->lower
);
410 if (!RB_EMPTY_NODE(&node
->rb_node
))
411 rb_erase(&node
->rb_node
, &tree
->rb_root
);
412 free_backref_node(tree
, node
);
416 * remove a backref node from the backref cache
418 static void remove_backref_node(struct backref_cache
*cache
,
419 struct backref_node
*node
)
421 struct backref_node
*upper
;
422 struct backref_edge
*edge
;
427 BUG_ON(!node
->lowest
&& !node
->detached
);
428 while (!list_empty(&node
->upper
)) {
429 edge
= list_entry(node
->upper
.next
, struct backref_edge
,
431 upper
= edge
->node
[UPPER
];
432 list_del(&edge
->list
[LOWER
]);
433 list_del(&edge
->list
[UPPER
]);
434 free_backref_edge(cache
, edge
);
436 if (RB_EMPTY_NODE(&upper
->rb_node
)) {
437 BUG_ON(!list_empty(&node
->upper
));
438 drop_backref_node(cache
, node
);
444 * add the node to leaf node list if no other
445 * child block cached.
447 if (list_empty(&upper
->lower
)) {
448 list_add_tail(&upper
->lower
, &cache
->leaves
);
453 drop_backref_node(cache
, node
);
456 static void update_backref_node(struct backref_cache
*cache
,
457 struct backref_node
*node
, u64 bytenr
)
459 struct rb_node
*rb_node
;
460 rb_erase(&node
->rb_node
, &cache
->rb_root
);
461 node
->bytenr
= bytenr
;
462 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
, &node
->rb_node
);
464 backref_tree_panic(rb_node
, -EEXIST
, bytenr
);
468 * update backref cache after a transaction commit
470 static int update_backref_cache(struct btrfs_trans_handle
*trans
,
471 struct backref_cache
*cache
)
473 struct backref_node
*node
;
476 if (cache
->last_trans
== 0) {
477 cache
->last_trans
= trans
->transid
;
481 if (cache
->last_trans
== trans
->transid
)
485 * detached nodes are used to avoid unnecessary backref
486 * lookup. transaction commit changes the extent tree.
487 * so the detached nodes are no longer useful.
489 while (!list_empty(&cache
->detached
)) {
490 node
= list_entry(cache
->detached
.next
,
491 struct backref_node
, list
);
492 remove_backref_node(cache
, node
);
495 while (!list_empty(&cache
->changed
)) {
496 node
= list_entry(cache
->changed
.next
,
497 struct backref_node
, list
);
498 list_del_init(&node
->list
);
499 BUG_ON(node
->pending
);
500 update_backref_node(cache
, node
, node
->new_bytenr
);
504 * some nodes can be left in the pending list if there were
505 * errors during processing the pending nodes.
507 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
508 list_for_each_entry(node
, &cache
->pending
[level
], list
) {
509 BUG_ON(!node
->pending
);
510 if (node
->bytenr
== node
->new_bytenr
)
512 update_backref_node(cache
, node
, node
->new_bytenr
);
516 cache
->last_trans
= 0;
521 static int should_ignore_root(struct btrfs_root
*root
)
523 struct btrfs_root
*reloc_root
;
525 if (!test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
))
528 reloc_root
= root
->reloc_root
;
532 if (btrfs_root_last_snapshot(&reloc_root
->root_item
) ==
533 root
->fs_info
->running_transaction
->transid
- 1)
536 * if there is reloc tree and it was created in previous
537 * transaction backref lookup can find the reloc tree,
538 * so backref node for the fs tree root is useless for
544 * find reloc tree by address of tree root
546 static struct btrfs_root
*find_reloc_root(struct reloc_control
*rc
,
549 struct rb_node
*rb_node
;
550 struct mapping_node
*node
;
551 struct btrfs_root
*root
= NULL
;
553 spin_lock(&rc
->reloc_root_tree
.lock
);
554 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
, bytenr
);
556 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
557 root
= (struct btrfs_root
*)node
->data
;
559 spin_unlock(&rc
->reloc_root_tree
.lock
);
563 static int is_cowonly_root(u64 root_objectid
)
565 if (root_objectid
== BTRFS_ROOT_TREE_OBJECTID
||
566 root_objectid
== BTRFS_EXTENT_TREE_OBJECTID
||
567 root_objectid
== BTRFS_CHUNK_TREE_OBJECTID
||
568 root_objectid
== BTRFS_DEV_TREE_OBJECTID
||
569 root_objectid
== BTRFS_TREE_LOG_OBJECTID
||
570 root_objectid
== BTRFS_CSUM_TREE_OBJECTID
||
571 root_objectid
== BTRFS_UUID_TREE_OBJECTID
||
572 root_objectid
== BTRFS_QUOTA_TREE_OBJECTID
||
573 root_objectid
== BTRFS_FREE_SPACE_TREE_OBJECTID
)
578 static struct btrfs_root
*read_fs_root(struct btrfs_fs_info
*fs_info
,
581 struct btrfs_key key
;
583 key
.objectid
= root_objectid
;
584 key
.type
= BTRFS_ROOT_ITEM_KEY
;
585 if (is_cowonly_root(root_objectid
))
588 key
.offset
= (u64
)-1;
590 return btrfs_get_fs_root(fs_info
, &key
, false);
593 static noinline_for_stack
594 int find_inline_backref(struct extent_buffer
*leaf
, int slot
,
595 unsigned long *ptr
, unsigned long *end
)
597 struct btrfs_key key
;
598 struct btrfs_extent_item
*ei
;
599 struct btrfs_tree_block_info
*bi
;
602 btrfs_item_key_to_cpu(leaf
, &key
, slot
);
604 item_size
= btrfs_item_size_nr(leaf
, slot
);
605 if (item_size
< sizeof(*ei
)) {
606 btrfs_print_v0_err(leaf
->fs_info
);
607 btrfs_handle_fs_error(leaf
->fs_info
, -EINVAL
, NULL
);
610 ei
= btrfs_item_ptr(leaf
, slot
, struct btrfs_extent_item
);
611 WARN_ON(!(btrfs_extent_flags(leaf
, ei
) &
612 BTRFS_EXTENT_FLAG_TREE_BLOCK
));
614 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
615 item_size
<= sizeof(*ei
) + sizeof(*bi
)) {
616 WARN_ON(item_size
< sizeof(*ei
) + sizeof(*bi
));
619 if (key
.type
== BTRFS_METADATA_ITEM_KEY
&&
620 item_size
<= sizeof(*ei
)) {
621 WARN_ON(item_size
< sizeof(*ei
));
625 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
) {
626 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
627 *ptr
= (unsigned long)(bi
+ 1);
629 *ptr
= (unsigned long)(ei
+ 1);
631 *end
= (unsigned long)ei
+ item_size
;
636 * build backref tree for a given tree block. root of the backref tree
637 * corresponds the tree block, leaves of the backref tree correspond
638 * roots of b-trees that reference the tree block.
640 * the basic idea of this function is check backrefs of a given block
641 * to find upper level blocks that reference the block, and then check
642 * backrefs of these upper level blocks recursively. the recursion stop
643 * when tree root is reached or backrefs for the block is cached.
645 * NOTE: if we find backrefs for a block are cached, we know backrefs
646 * for all upper level blocks that directly/indirectly reference the
647 * block are also cached.
649 static noinline_for_stack
650 struct backref_node
*build_backref_tree(struct reloc_control
*rc
,
651 struct btrfs_key
*node_key
,
652 int level
, u64 bytenr
)
654 struct backref_cache
*cache
= &rc
->backref_cache
;
655 struct btrfs_path
*path1
; /* For searching extent root */
656 struct btrfs_path
*path2
; /* For searching parent of TREE_BLOCK_REF */
657 struct extent_buffer
*eb
;
658 struct btrfs_root
*root
;
659 struct backref_node
*cur
;
660 struct backref_node
*upper
;
661 struct backref_node
*lower
;
662 struct backref_node
*node
= NULL
;
663 struct backref_node
*exist
= NULL
;
664 struct backref_edge
*edge
;
665 struct rb_node
*rb_node
;
666 struct btrfs_key key
;
669 LIST_HEAD(list
); /* Pending edge list, upper node needs to be checked */
674 bool need_check
= true;
676 path1
= btrfs_alloc_path();
677 path2
= btrfs_alloc_path();
678 if (!path1
|| !path2
) {
682 path1
->reada
= READA_FORWARD
;
683 path2
->reada
= READA_FORWARD
;
685 node
= alloc_backref_node(cache
);
691 node
->bytenr
= bytenr
;
698 key
.objectid
= cur
->bytenr
;
699 key
.type
= BTRFS_METADATA_ITEM_KEY
;
700 key
.offset
= (u64
)-1;
702 path1
->search_commit_root
= 1;
703 path1
->skip_locking
= 1;
704 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path1
,
711 ASSERT(path1
->slots
[0]);
715 WARN_ON(cur
->checked
);
716 if (!list_empty(&cur
->upper
)) {
718 * the backref was added previously when processing
719 * backref of type BTRFS_TREE_BLOCK_REF_KEY
721 ASSERT(list_is_singular(&cur
->upper
));
722 edge
= list_entry(cur
->upper
.next
, struct backref_edge
,
724 ASSERT(list_empty(&edge
->list
[UPPER
]));
725 exist
= edge
->node
[UPPER
];
727 * add the upper level block to pending list if we need
731 list_add_tail(&edge
->list
[UPPER
], &list
);
738 eb
= path1
->nodes
[0];
741 if (path1
->slots
[0] >= btrfs_header_nritems(eb
)) {
742 ret
= btrfs_next_leaf(rc
->extent_root
, path1
);
749 eb
= path1
->nodes
[0];
752 btrfs_item_key_to_cpu(eb
, &key
, path1
->slots
[0]);
753 if (key
.objectid
!= cur
->bytenr
) {
758 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
||
759 key
.type
== BTRFS_METADATA_ITEM_KEY
) {
760 ret
= find_inline_backref(eb
, path1
->slots
[0],
768 /* update key for inline back ref */
769 struct btrfs_extent_inline_ref
*iref
;
771 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
772 type
= btrfs_get_extent_inline_ref_type(eb
, iref
,
773 BTRFS_REF_TYPE_BLOCK
);
774 if (type
== BTRFS_REF_TYPE_INVALID
) {
779 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
781 WARN_ON(key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
&&
782 key
.type
!= BTRFS_SHARED_BLOCK_REF_KEY
);
786 * Parent node found and matches current inline ref, no need to
787 * rebuild this node for this inline ref.
790 ((key
.type
== BTRFS_TREE_BLOCK_REF_KEY
&&
791 exist
->owner
== key
.offset
) ||
792 (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
&&
793 exist
->bytenr
== key
.offset
))) {
798 /* SHARED_BLOCK_REF means key.offset is the parent bytenr */
799 if (key
.type
== BTRFS_SHARED_BLOCK_REF_KEY
) {
800 if (key
.objectid
== key
.offset
) {
802 * Only root blocks of reloc trees use backref
803 * pointing to itself.
805 root
= find_reloc_root(rc
, cur
->bytenr
);
811 edge
= alloc_backref_edge(cache
);
816 rb_node
= tree_search(&cache
->rb_root
, key
.offset
);
818 upper
= alloc_backref_node(cache
);
820 free_backref_edge(cache
, edge
);
824 upper
->bytenr
= key
.offset
;
825 upper
->level
= cur
->level
+ 1;
827 * backrefs for the upper level block isn't
828 * cached, add the block to pending list
830 list_add_tail(&edge
->list
[UPPER
], &list
);
832 upper
= rb_entry(rb_node
, struct backref_node
,
834 ASSERT(upper
->checked
);
835 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
837 list_add_tail(&edge
->list
[LOWER
], &cur
->upper
);
838 edge
->node
[LOWER
] = cur
;
839 edge
->node
[UPPER
] = upper
;
842 } else if (unlikely(key
.type
== BTRFS_EXTENT_REF_V0_KEY
)) {
844 btrfs_print_v0_err(rc
->extent_root
->fs_info
);
845 btrfs_handle_fs_error(rc
->extent_root
->fs_info
, err
,
848 } else if (key
.type
!= BTRFS_TREE_BLOCK_REF_KEY
) {
853 * key.type == BTRFS_TREE_BLOCK_REF_KEY, inline ref offset
854 * means the root objectid. We need to search the tree to get
857 root
= read_fs_root(rc
->extent_root
->fs_info
, key
.offset
);
863 if (!test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
))
866 if (btrfs_root_level(&root
->root_item
) == cur
->level
) {
868 ASSERT(btrfs_root_bytenr(&root
->root_item
) ==
870 if (should_ignore_root(root
))
871 list_add(&cur
->list
, &useless
);
877 level
= cur
->level
+ 1;
879 /* Search the tree to find parent blocks referring the block. */
880 path2
->search_commit_root
= 1;
881 path2
->skip_locking
= 1;
882 path2
->lowest_level
= level
;
883 ret
= btrfs_search_slot(NULL
, root
, node_key
, path2
, 0, 0);
884 path2
->lowest_level
= 0;
889 if (ret
> 0 && path2
->slots
[level
] > 0)
890 path2
->slots
[level
]--;
892 eb
= path2
->nodes
[level
];
893 if (btrfs_node_blockptr(eb
, path2
->slots
[level
]) !=
895 btrfs_err(root
->fs_info
,
896 "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)",
897 cur
->bytenr
, level
- 1,
898 root
->root_key
.objectid
,
899 node_key
->objectid
, node_key
->type
,
907 /* Add all nodes and edges in the path */
908 for (; level
< BTRFS_MAX_LEVEL
; level
++) {
909 if (!path2
->nodes
[level
]) {
910 ASSERT(btrfs_root_bytenr(&root
->root_item
) ==
912 if (should_ignore_root(root
))
913 list_add(&lower
->list
, &useless
);
919 edge
= alloc_backref_edge(cache
);
925 eb
= path2
->nodes
[level
];
926 rb_node
= tree_search(&cache
->rb_root
, eb
->start
);
928 upper
= alloc_backref_node(cache
);
930 free_backref_edge(cache
, edge
);
934 upper
->bytenr
= eb
->start
;
935 upper
->owner
= btrfs_header_owner(eb
);
936 upper
->level
= lower
->level
+ 1;
937 if (!test_bit(BTRFS_ROOT_REF_COWS
,
942 * if we know the block isn't shared
943 * we can void checking its backrefs.
945 if (btrfs_block_can_be_shared(root
, eb
))
951 * add the block to pending list if we
952 * need check its backrefs, we only do this once
953 * while walking up a tree as we will catch
954 * anything else later on.
956 if (!upper
->checked
&& need_check
) {
958 list_add_tail(&edge
->list
[UPPER
],
963 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
966 upper
= rb_entry(rb_node
, struct backref_node
,
968 ASSERT(upper
->checked
);
969 INIT_LIST_HEAD(&edge
->list
[UPPER
]);
971 upper
->owner
= btrfs_header_owner(eb
);
973 list_add_tail(&edge
->list
[LOWER
], &lower
->upper
);
974 edge
->node
[LOWER
] = lower
;
975 edge
->node
[UPPER
] = upper
;
982 btrfs_release_path(path2
);
985 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
995 btrfs_release_path(path1
);
1000 /* the pending list isn't empty, take the first block to process */
1001 if (!list_empty(&list
)) {
1002 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1003 list_del_init(&edge
->list
[UPPER
]);
1004 cur
= edge
->node
[UPPER
];
1009 * everything goes well, connect backref nodes and insert backref nodes
1012 ASSERT(node
->checked
);
1013 cowonly
= node
->cowonly
;
1015 rb_node
= tree_insert(&cache
->rb_root
, node
->bytenr
,
1018 backref_tree_panic(rb_node
, -EEXIST
, node
->bytenr
);
1019 list_add_tail(&node
->lower
, &cache
->leaves
);
1022 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
])
1023 list_add_tail(&edge
->list
[UPPER
], &list
);
1025 while (!list_empty(&list
)) {
1026 edge
= list_entry(list
.next
, struct backref_edge
, list
[UPPER
]);
1027 list_del_init(&edge
->list
[UPPER
]);
1028 upper
= edge
->node
[UPPER
];
1029 if (upper
->detached
) {
1030 list_del(&edge
->list
[LOWER
]);
1031 lower
= edge
->node
[LOWER
];
1032 free_backref_edge(cache
, edge
);
1033 if (list_empty(&lower
->upper
))
1034 list_add(&lower
->list
, &useless
);
1038 if (!RB_EMPTY_NODE(&upper
->rb_node
)) {
1039 if (upper
->lowest
) {
1040 list_del_init(&upper
->lower
);
1044 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1048 if (!upper
->checked
) {
1050 * Still want to blow up for developers since this is a
1057 if (cowonly
!= upper
->cowonly
) {
1064 rb_node
= tree_insert(&cache
->rb_root
, upper
->bytenr
,
1067 backref_tree_panic(rb_node
, -EEXIST
,
1071 list_add_tail(&edge
->list
[UPPER
], &upper
->lower
);
1073 list_for_each_entry(edge
, &upper
->upper
, list
[LOWER
])
1074 list_add_tail(&edge
->list
[UPPER
], &list
);
1077 * process useless backref nodes. backref nodes for tree leaves
1078 * are deleted from the cache. backref nodes for upper level
1079 * tree blocks are left in the cache to avoid unnecessary backref
1082 while (!list_empty(&useless
)) {
1083 upper
= list_entry(useless
.next
, struct backref_node
, list
);
1084 list_del_init(&upper
->list
);
1085 ASSERT(list_empty(&upper
->upper
));
1088 if (upper
->lowest
) {
1089 list_del_init(&upper
->lower
);
1092 while (!list_empty(&upper
->lower
)) {
1093 edge
= list_entry(upper
->lower
.next
,
1094 struct backref_edge
, list
[UPPER
]);
1095 list_del(&edge
->list
[UPPER
]);
1096 list_del(&edge
->list
[LOWER
]);
1097 lower
= edge
->node
[LOWER
];
1098 free_backref_edge(cache
, edge
);
1100 if (list_empty(&lower
->upper
))
1101 list_add(&lower
->list
, &useless
);
1103 __mark_block_processed(rc
, upper
);
1104 if (upper
->level
> 0) {
1105 list_add(&upper
->list
, &cache
->detached
);
1106 upper
->detached
= 1;
1108 rb_erase(&upper
->rb_node
, &cache
->rb_root
);
1109 free_backref_node(cache
, upper
);
1113 btrfs_free_path(path1
);
1114 btrfs_free_path(path2
);
1116 while (!list_empty(&useless
)) {
1117 lower
= list_entry(useless
.next
,
1118 struct backref_node
, list
);
1119 list_del_init(&lower
->list
);
1121 while (!list_empty(&list
)) {
1122 edge
= list_first_entry(&list
, struct backref_edge
,
1124 list_del(&edge
->list
[UPPER
]);
1125 list_del(&edge
->list
[LOWER
]);
1126 lower
= edge
->node
[LOWER
];
1127 upper
= edge
->node
[UPPER
];
1128 free_backref_edge(cache
, edge
);
1131 * Lower is no longer linked to any upper backref nodes
1132 * and isn't in the cache, we can free it ourselves.
1134 if (list_empty(&lower
->upper
) &&
1135 RB_EMPTY_NODE(&lower
->rb_node
))
1136 list_add(&lower
->list
, &useless
);
1138 if (!RB_EMPTY_NODE(&upper
->rb_node
))
1141 /* Add this guy's upper edges to the list to process */
1142 list_for_each_entry(edge
, &upper
->upper
, list
[LOWER
])
1143 list_add_tail(&edge
->list
[UPPER
], &list
);
1144 if (list_empty(&upper
->upper
))
1145 list_add(&upper
->list
, &useless
);
1148 while (!list_empty(&useless
)) {
1149 lower
= list_entry(useless
.next
,
1150 struct backref_node
, list
);
1151 list_del_init(&lower
->list
);
1154 free_backref_node(cache
, lower
);
1157 free_backref_node(cache
, node
);
1158 return ERR_PTR(err
);
1160 ASSERT(!node
|| !node
->detached
);
1165 * helper to add backref node for the newly created snapshot.
1166 * the backref node is created by cloning backref node that
1167 * corresponds to root of source tree
1169 static int clone_backref_node(struct btrfs_trans_handle
*trans
,
1170 struct reloc_control
*rc
,
1171 struct btrfs_root
*src
,
1172 struct btrfs_root
*dest
)
1174 struct btrfs_root
*reloc_root
= src
->reloc_root
;
1175 struct backref_cache
*cache
= &rc
->backref_cache
;
1176 struct backref_node
*node
= NULL
;
1177 struct backref_node
*new_node
;
1178 struct backref_edge
*edge
;
1179 struct backref_edge
*new_edge
;
1180 struct rb_node
*rb_node
;
1182 if (cache
->last_trans
> 0)
1183 update_backref_cache(trans
, cache
);
1185 rb_node
= tree_search(&cache
->rb_root
, src
->commit_root
->start
);
1187 node
= rb_entry(rb_node
, struct backref_node
, rb_node
);
1191 BUG_ON(node
->new_bytenr
!= reloc_root
->node
->start
);
1195 rb_node
= tree_search(&cache
->rb_root
,
1196 reloc_root
->commit_root
->start
);
1198 node
= rb_entry(rb_node
, struct backref_node
,
1200 BUG_ON(node
->detached
);
1207 new_node
= alloc_backref_node(cache
);
1211 new_node
->bytenr
= dest
->node
->start
;
1212 new_node
->level
= node
->level
;
1213 new_node
->lowest
= node
->lowest
;
1214 new_node
->checked
= 1;
1215 new_node
->root
= dest
;
1217 if (!node
->lowest
) {
1218 list_for_each_entry(edge
, &node
->lower
, list
[UPPER
]) {
1219 new_edge
= alloc_backref_edge(cache
);
1223 new_edge
->node
[UPPER
] = new_node
;
1224 new_edge
->node
[LOWER
] = edge
->node
[LOWER
];
1225 list_add_tail(&new_edge
->list
[UPPER
],
1229 list_add_tail(&new_node
->lower
, &cache
->leaves
);
1232 rb_node
= tree_insert(&cache
->rb_root
, new_node
->bytenr
,
1233 &new_node
->rb_node
);
1235 backref_tree_panic(rb_node
, -EEXIST
, new_node
->bytenr
);
1237 if (!new_node
->lowest
) {
1238 list_for_each_entry(new_edge
, &new_node
->lower
, list
[UPPER
]) {
1239 list_add_tail(&new_edge
->list
[LOWER
],
1240 &new_edge
->node
[LOWER
]->upper
);
1245 while (!list_empty(&new_node
->lower
)) {
1246 new_edge
= list_entry(new_node
->lower
.next
,
1247 struct backref_edge
, list
[UPPER
]);
1248 list_del(&new_edge
->list
[UPPER
]);
1249 free_backref_edge(cache
, new_edge
);
1251 free_backref_node(cache
, new_node
);
1256 * helper to add 'address of tree root -> reloc tree' mapping
1258 static int __must_check
__add_reloc_root(struct btrfs_root
*root
)
1260 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1261 struct rb_node
*rb_node
;
1262 struct mapping_node
*node
;
1263 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
1265 node
= kmalloc(sizeof(*node
), GFP_NOFS
);
1269 node
->bytenr
= root
->node
->start
;
1272 spin_lock(&rc
->reloc_root_tree
.lock
);
1273 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1274 node
->bytenr
, &node
->rb_node
);
1275 spin_unlock(&rc
->reloc_root_tree
.lock
);
1277 btrfs_panic(fs_info
, -EEXIST
,
1278 "Duplicate root found for start=%llu while inserting into relocation tree",
1282 list_add_tail(&root
->root_list
, &rc
->reloc_roots
);
1287 * helper to delete the 'address of tree root -> reloc tree'
1290 static void __del_reloc_root(struct btrfs_root
*root
)
1292 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1293 struct rb_node
*rb_node
;
1294 struct mapping_node
*node
= NULL
;
1295 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
1297 if (rc
&& root
->node
) {
1298 spin_lock(&rc
->reloc_root_tree
.lock
);
1299 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
,
1302 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
1303 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
1305 spin_unlock(&rc
->reloc_root_tree
.lock
);
1308 BUG_ON((struct btrfs_root
*)node
->data
!= root
);
1311 spin_lock(&fs_info
->trans_lock
);
1312 list_del_init(&root
->root_list
);
1313 spin_unlock(&fs_info
->trans_lock
);
1318 * helper to update the 'address of tree root -> reloc tree'
1321 static int __update_reloc_root(struct btrfs_root
*root
, u64 new_bytenr
)
1323 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1324 struct rb_node
*rb_node
;
1325 struct mapping_node
*node
= NULL
;
1326 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
1328 spin_lock(&rc
->reloc_root_tree
.lock
);
1329 rb_node
= tree_search(&rc
->reloc_root_tree
.rb_root
,
1332 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
1333 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
1335 spin_unlock(&rc
->reloc_root_tree
.lock
);
1339 BUG_ON((struct btrfs_root
*)node
->data
!= root
);
1341 spin_lock(&rc
->reloc_root_tree
.lock
);
1342 node
->bytenr
= new_bytenr
;
1343 rb_node
= tree_insert(&rc
->reloc_root_tree
.rb_root
,
1344 node
->bytenr
, &node
->rb_node
);
1345 spin_unlock(&rc
->reloc_root_tree
.lock
);
1347 backref_tree_panic(rb_node
, -EEXIST
, node
->bytenr
);
1351 static struct btrfs_root
*create_reloc_root(struct btrfs_trans_handle
*trans
,
1352 struct btrfs_root
*root
, u64 objectid
)
1354 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1355 struct btrfs_root
*reloc_root
;
1356 struct extent_buffer
*eb
;
1357 struct btrfs_root_item
*root_item
;
1358 struct btrfs_key root_key
;
1361 root_item
= kmalloc(sizeof(*root_item
), GFP_NOFS
);
1364 root_key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
1365 root_key
.type
= BTRFS_ROOT_ITEM_KEY
;
1366 root_key
.offset
= objectid
;
1368 if (root
->root_key
.objectid
== objectid
) {
1369 u64 commit_root_gen
;
1371 /* called by btrfs_init_reloc_root */
1372 ret
= btrfs_copy_root(trans
, root
, root
->commit_root
, &eb
,
1373 BTRFS_TREE_RELOC_OBJECTID
);
1376 * Set the last_snapshot field to the generation of the commit
1377 * root - like this ctree.c:btrfs_block_can_be_shared() behaves
1378 * correctly (returns true) when the relocation root is created
1379 * either inside the critical section of a transaction commit
1380 * (through transaction.c:qgroup_account_snapshot()) and when
1381 * it's created before the transaction commit is started.
1383 commit_root_gen
= btrfs_header_generation(root
->commit_root
);
1384 btrfs_set_root_last_snapshot(&root
->root_item
, commit_root_gen
);
1387 * called by btrfs_reloc_post_snapshot_hook.
1388 * the source tree is a reloc tree, all tree blocks
1389 * modified after it was created have RELOC flag
1390 * set in their headers. so it's OK to not update
1391 * the 'last_snapshot'.
1393 ret
= btrfs_copy_root(trans
, root
, root
->node
, &eb
,
1394 BTRFS_TREE_RELOC_OBJECTID
);
1398 memcpy(root_item
, &root
->root_item
, sizeof(*root_item
));
1399 btrfs_set_root_bytenr(root_item
, eb
->start
);
1400 btrfs_set_root_level(root_item
, btrfs_header_level(eb
));
1401 btrfs_set_root_generation(root_item
, trans
->transid
);
1403 if (root
->root_key
.objectid
== objectid
) {
1404 btrfs_set_root_refs(root_item
, 0);
1405 memset(&root_item
->drop_progress
, 0,
1406 sizeof(struct btrfs_disk_key
));
1407 root_item
->drop_level
= 0;
1410 btrfs_tree_unlock(eb
);
1411 free_extent_buffer(eb
);
1413 ret
= btrfs_insert_root(trans
, fs_info
->tree_root
,
1414 &root_key
, root_item
);
1418 reloc_root
= btrfs_read_fs_root(fs_info
->tree_root
, &root_key
);
1419 BUG_ON(IS_ERR(reloc_root
));
1420 reloc_root
->last_trans
= trans
->transid
;
1425 * create reloc tree for a given fs tree. reloc tree is just a
1426 * snapshot of the fs tree with special root objectid.
1428 int btrfs_init_reloc_root(struct btrfs_trans_handle
*trans
,
1429 struct btrfs_root
*root
)
1431 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1432 struct btrfs_root
*reloc_root
;
1433 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
1434 struct btrfs_block_rsv
*rsv
;
1439 * The subvolume has reloc tree but the swap is finished, no need to
1440 * create/update the dead reloc tree
1442 if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE
, &root
->state
))
1445 if (root
->reloc_root
) {
1446 reloc_root
= root
->reloc_root
;
1447 reloc_root
->last_trans
= trans
->transid
;
1451 if (!rc
|| !rc
->create_reloc_tree
||
1452 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1455 if (!trans
->reloc_reserved
) {
1456 rsv
= trans
->block_rsv
;
1457 trans
->block_rsv
= rc
->block_rsv
;
1460 reloc_root
= create_reloc_root(trans
, root
, root
->root_key
.objectid
);
1462 trans
->block_rsv
= rsv
;
1464 ret
= __add_reloc_root(reloc_root
);
1466 root
->reloc_root
= reloc_root
;
1471 * update root item of reloc tree
1473 int btrfs_update_reloc_root(struct btrfs_trans_handle
*trans
,
1474 struct btrfs_root
*root
)
1476 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1477 struct btrfs_root
*reloc_root
;
1478 struct btrfs_root_item
*root_item
;
1481 if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE
, &root
->state
) ||
1485 reloc_root
= root
->reloc_root
;
1486 root_item
= &reloc_root
->root_item
;
1488 /* root->reloc_root will stay until current relocation finished */
1489 if (fs_info
->reloc_ctl
->merge_reloc_tree
&&
1490 btrfs_root_refs(root_item
) == 0) {
1491 set_bit(BTRFS_ROOT_DEAD_RELOC_TREE
, &root
->state
);
1492 __del_reloc_root(reloc_root
);
1495 if (reloc_root
->commit_root
!= reloc_root
->node
) {
1496 btrfs_set_root_node(root_item
, reloc_root
->node
);
1497 free_extent_buffer(reloc_root
->commit_root
);
1498 reloc_root
->commit_root
= btrfs_root_node(reloc_root
);
1501 ret
= btrfs_update_root(trans
, fs_info
->tree_root
,
1502 &reloc_root
->root_key
, root_item
);
1510 * helper to find first cached inode with inode number >= objectid
1513 static struct inode
*find_next_inode(struct btrfs_root
*root
, u64 objectid
)
1515 struct rb_node
*node
;
1516 struct rb_node
*prev
;
1517 struct btrfs_inode
*entry
;
1518 struct inode
*inode
;
1520 spin_lock(&root
->inode_lock
);
1522 node
= root
->inode_tree
.rb_node
;
1526 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1528 if (objectid
< btrfs_ino(entry
))
1529 node
= node
->rb_left
;
1530 else if (objectid
> btrfs_ino(entry
))
1531 node
= node
->rb_right
;
1537 entry
= rb_entry(prev
, struct btrfs_inode
, rb_node
);
1538 if (objectid
<= btrfs_ino(entry
)) {
1542 prev
= rb_next(prev
);
1546 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
1547 inode
= igrab(&entry
->vfs_inode
);
1549 spin_unlock(&root
->inode_lock
);
1553 objectid
= btrfs_ino(entry
) + 1;
1554 if (cond_resched_lock(&root
->inode_lock
))
1557 node
= rb_next(node
);
1559 spin_unlock(&root
->inode_lock
);
1563 static int in_block_group(u64 bytenr
, struct btrfs_block_group
*block_group
)
1565 if (bytenr
>= block_group
->start
&&
1566 bytenr
< block_group
->start
+ block_group
->length
)
1572 * get new location of data
1574 static int get_new_location(struct inode
*reloc_inode
, u64
*new_bytenr
,
1575 u64 bytenr
, u64 num_bytes
)
1577 struct btrfs_root
*root
= BTRFS_I(reloc_inode
)->root
;
1578 struct btrfs_path
*path
;
1579 struct btrfs_file_extent_item
*fi
;
1580 struct extent_buffer
*leaf
;
1583 path
= btrfs_alloc_path();
1587 bytenr
-= BTRFS_I(reloc_inode
)->index_cnt
;
1588 ret
= btrfs_lookup_file_extent(NULL
, root
, path
,
1589 btrfs_ino(BTRFS_I(reloc_inode
)), bytenr
, 0);
1597 leaf
= path
->nodes
[0];
1598 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
1599 struct btrfs_file_extent_item
);
1601 BUG_ON(btrfs_file_extent_offset(leaf
, fi
) ||
1602 btrfs_file_extent_compression(leaf
, fi
) ||
1603 btrfs_file_extent_encryption(leaf
, fi
) ||
1604 btrfs_file_extent_other_encoding(leaf
, fi
));
1606 if (num_bytes
!= btrfs_file_extent_disk_num_bytes(leaf
, fi
)) {
1611 *new_bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1614 btrfs_free_path(path
);
1619 * update file extent items in the tree leaf to point to
1620 * the new locations.
1622 static noinline_for_stack
1623 int replace_file_extents(struct btrfs_trans_handle
*trans
,
1624 struct reloc_control
*rc
,
1625 struct btrfs_root
*root
,
1626 struct extent_buffer
*leaf
)
1628 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1629 struct btrfs_key key
;
1630 struct btrfs_file_extent_item
*fi
;
1631 struct inode
*inode
= NULL
;
1643 if (rc
->stage
!= UPDATE_DATA_PTRS
)
1646 /* reloc trees always use full backref */
1647 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1648 parent
= leaf
->start
;
1652 nritems
= btrfs_header_nritems(leaf
);
1653 for (i
= 0; i
< nritems
; i
++) {
1654 struct btrfs_ref ref
= { 0 };
1657 btrfs_item_key_to_cpu(leaf
, &key
, i
);
1658 if (key
.type
!= BTRFS_EXTENT_DATA_KEY
)
1660 fi
= btrfs_item_ptr(leaf
, i
, struct btrfs_file_extent_item
);
1661 if (btrfs_file_extent_type(leaf
, fi
) ==
1662 BTRFS_FILE_EXTENT_INLINE
)
1664 bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1665 num_bytes
= btrfs_file_extent_disk_num_bytes(leaf
, fi
);
1668 if (!in_block_group(bytenr
, rc
->block_group
))
1672 * if we are modifying block in fs tree, wait for readpage
1673 * to complete and drop the extent cache
1675 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
) {
1677 inode
= find_next_inode(root
, key
.objectid
);
1679 } else if (inode
&& btrfs_ino(BTRFS_I(inode
)) < key
.objectid
) {
1680 btrfs_add_delayed_iput(inode
);
1681 inode
= find_next_inode(root
, key
.objectid
);
1683 if (inode
&& btrfs_ino(BTRFS_I(inode
)) == key
.objectid
) {
1685 btrfs_file_extent_num_bytes(leaf
, fi
);
1686 WARN_ON(!IS_ALIGNED(key
.offset
,
1687 fs_info
->sectorsize
));
1688 WARN_ON(!IS_ALIGNED(end
, fs_info
->sectorsize
));
1690 ret
= try_lock_extent(&BTRFS_I(inode
)->io_tree
,
1695 btrfs_drop_extent_cache(BTRFS_I(inode
),
1696 key
.offset
, end
, 1);
1697 unlock_extent(&BTRFS_I(inode
)->io_tree
,
1702 ret
= get_new_location(rc
->data_inode
, &new_bytenr
,
1706 * Don't have to abort since we've not changed anything
1707 * in the file extent yet.
1712 btrfs_set_file_extent_disk_bytenr(leaf
, fi
, new_bytenr
);
1715 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
1716 btrfs_init_generic_ref(&ref
, BTRFS_ADD_DELAYED_REF
, new_bytenr
,
1718 ref
.real_root
= root
->root_key
.objectid
;
1719 btrfs_init_data_ref(&ref
, btrfs_header_owner(leaf
),
1720 key
.objectid
, key
.offset
);
1721 ret
= btrfs_inc_extent_ref(trans
, &ref
);
1723 btrfs_abort_transaction(trans
, ret
);
1727 btrfs_init_generic_ref(&ref
, BTRFS_DROP_DELAYED_REF
, bytenr
,
1729 ref
.real_root
= root
->root_key
.objectid
;
1730 btrfs_init_data_ref(&ref
, btrfs_header_owner(leaf
),
1731 key
.objectid
, key
.offset
);
1732 ret
= btrfs_free_extent(trans
, &ref
);
1734 btrfs_abort_transaction(trans
, ret
);
1739 btrfs_mark_buffer_dirty(leaf
);
1741 btrfs_add_delayed_iput(inode
);
1745 static noinline_for_stack
1746 int memcmp_node_keys(struct extent_buffer
*eb
, int slot
,
1747 struct btrfs_path
*path
, int level
)
1749 struct btrfs_disk_key key1
;
1750 struct btrfs_disk_key key2
;
1751 btrfs_node_key(eb
, &key1
, slot
);
1752 btrfs_node_key(path
->nodes
[level
], &key2
, path
->slots
[level
]);
1753 return memcmp(&key1
, &key2
, sizeof(key1
));
1757 * try to replace tree blocks in fs tree with the new blocks
1758 * in reloc tree. tree blocks haven't been modified since the
1759 * reloc tree was create can be replaced.
1761 * if a block was replaced, level of the block + 1 is returned.
1762 * if no block got replaced, 0 is returned. if there are other
1763 * errors, a negative error number is returned.
1765 static noinline_for_stack
1766 int replace_path(struct btrfs_trans_handle
*trans
, struct reloc_control
*rc
,
1767 struct btrfs_root
*dest
, struct btrfs_root
*src
,
1768 struct btrfs_path
*path
, struct btrfs_key
*next_key
,
1769 int lowest_level
, int max_level
)
1771 struct btrfs_fs_info
*fs_info
= dest
->fs_info
;
1772 struct extent_buffer
*eb
;
1773 struct extent_buffer
*parent
;
1774 struct btrfs_ref ref
= { 0 };
1775 struct btrfs_key key
;
1787 BUG_ON(src
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
);
1788 BUG_ON(dest
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
);
1790 last_snapshot
= btrfs_root_last_snapshot(&src
->root_item
);
1792 slot
= path
->slots
[lowest_level
];
1793 btrfs_node_key_to_cpu(path
->nodes
[lowest_level
], &key
, slot
);
1795 eb
= btrfs_lock_root_node(dest
);
1796 btrfs_set_lock_blocking_write(eb
);
1797 level
= btrfs_header_level(eb
);
1799 if (level
< lowest_level
) {
1800 btrfs_tree_unlock(eb
);
1801 free_extent_buffer(eb
);
1806 ret
= btrfs_cow_block(trans
, dest
, eb
, NULL
, 0, &eb
);
1809 btrfs_set_lock_blocking_write(eb
);
1812 next_key
->objectid
= (u64
)-1;
1813 next_key
->type
= (u8
)-1;
1814 next_key
->offset
= (u64
)-1;
1819 struct btrfs_key first_key
;
1821 level
= btrfs_header_level(parent
);
1822 BUG_ON(level
< lowest_level
);
1824 ret
= btrfs_bin_search(parent
, &key
, level
, &slot
);
1827 if (ret
&& slot
> 0)
1830 if (next_key
&& slot
+ 1 < btrfs_header_nritems(parent
))
1831 btrfs_node_key_to_cpu(parent
, next_key
, slot
+ 1);
1833 old_bytenr
= btrfs_node_blockptr(parent
, slot
);
1834 blocksize
= fs_info
->nodesize
;
1835 old_ptr_gen
= btrfs_node_ptr_generation(parent
, slot
);
1836 btrfs_node_key_to_cpu(parent
, &first_key
, slot
);
1838 if (level
<= max_level
) {
1839 eb
= path
->nodes
[level
];
1840 new_bytenr
= btrfs_node_blockptr(eb
,
1841 path
->slots
[level
]);
1842 new_ptr_gen
= btrfs_node_ptr_generation(eb
,
1843 path
->slots
[level
]);
1849 if (WARN_ON(new_bytenr
> 0 && new_bytenr
== old_bytenr
)) {
1854 if (new_bytenr
== 0 || old_ptr_gen
> last_snapshot
||
1855 memcmp_node_keys(parent
, slot
, path
, level
)) {
1856 if (level
<= lowest_level
) {
1861 eb
= read_tree_block(fs_info
, old_bytenr
, old_ptr_gen
,
1862 level
- 1, &first_key
);
1866 } else if (!extent_buffer_uptodate(eb
)) {
1868 free_extent_buffer(eb
);
1871 btrfs_tree_lock(eb
);
1873 ret
= btrfs_cow_block(trans
, dest
, eb
, parent
,
1877 btrfs_set_lock_blocking_write(eb
);
1879 btrfs_tree_unlock(parent
);
1880 free_extent_buffer(parent
);
1887 btrfs_tree_unlock(parent
);
1888 free_extent_buffer(parent
);
1893 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
1894 path
->slots
[level
]);
1895 btrfs_release_path(path
);
1897 path
->lowest_level
= level
;
1898 ret
= btrfs_search_slot(trans
, src
, &key
, path
, 0, 1);
1899 path
->lowest_level
= 0;
1903 * Info qgroup to trace both subtrees.
1905 * We must trace both trees.
1906 * 1) Tree reloc subtree
1907 * If not traced, we will leak data numbers
1909 * If not traced, we will double count old data
1911 * We don't scan the subtree right now, but only record
1912 * the swapped tree blocks.
1913 * The real subtree rescan is delayed until we have new
1914 * CoW on the subtree root node before transaction commit.
1916 ret
= btrfs_qgroup_add_swapped_blocks(trans
, dest
,
1917 rc
->block_group
, parent
, slot
,
1918 path
->nodes
[level
], path
->slots
[level
],
1923 * swap blocks in fs tree and reloc tree.
1925 btrfs_set_node_blockptr(parent
, slot
, new_bytenr
);
1926 btrfs_set_node_ptr_generation(parent
, slot
, new_ptr_gen
);
1927 btrfs_mark_buffer_dirty(parent
);
1929 btrfs_set_node_blockptr(path
->nodes
[level
],
1930 path
->slots
[level
], old_bytenr
);
1931 btrfs_set_node_ptr_generation(path
->nodes
[level
],
1932 path
->slots
[level
], old_ptr_gen
);
1933 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
1935 btrfs_init_generic_ref(&ref
, BTRFS_ADD_DELAYED_REF
, old_bytenr
,
1936 blocksize
, path
->nodes
[level
]->start
);
1937 ref
.skip_qgroup
= true;
1938 btrfs_init_tree_ref(&ref
, level
- 1, src
->root_key
.objectid
);
1939 ret
= btrfs_inc_extent_ref(trans
, &ref
);
1941 btrfs_init_generic_ref(&ref
, BTRFS_ADD_DELAYED_REF
, new_bytenr
,
1943 ref
.skip_qgroup
= true;
1944 btrfs_init_tree_ref(&ref
, level
- 1, dest
->root_key
.objectid
);
1945 ret
= btrfs_inc_extent_ref(trans
, &ref
);
1948 btrfs_init_generic_ref(&ref
, BTRFS_DROP_DELAYED_REF
, new_bytenr
,
1949 blocksize
, path
->nodes
[level
]->start
);
1950 btrfs_init_tree_ref(&ref
, level
- 1, src
->root_key
.objectid
);
1951 ref
.skip_qgroup
= true;
1952 ret
= btrfs_free_extent(trans
, &ref
);
1955 btrfs_init_generic_ref(&ref
, BTRFS_DROP_DELAYED_REF
, old_bytenr
,
1957 btrfs_init_tree_ref(&ref
, level
- 1, dest
->root_key
.objectid
);
1958 ref
.skip_qgroup
= true;
1959 ret
= btrfs_free_extent(trans
, &ref
);
1962 btrfs_unlock_up_safe(path
, 0);
1967 btrfs_tree_unlock(parent
);
1968 free_extent_buffer(parent
);
1973 * helper to find next relocated block in reloc tree
1975 static noinline_for_stack
1976 int walk_up_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1979 struct extent_buffer
*eb
;
1984 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1986 for (i
= 0; i
< *level
; i
++) {
1987 free_extent_buffer(path
->nodes
[i
]);
1988 path
->nodes
[i
] = NULL
;
1991 for (i
= *level
; i
< BTRFS_MAX_LEVEL
&& path
->nodes
[i
]; i
++) {
1992 eb
= path
->nodes
[i
];
1993 nritems
= btrfs_header_nritems(eb
);
1994 while (path
->slots
[i
] + 1 < nritems
) {
1996 if (btrfs_node_ptr_generation(eb
, path
->slots
[i
]) <=
2003 free_extent_buffer(path
->nodes
[i
]);
2004 path
->nodes
[i
] = NULL
;
2010 * walk down reloc tree to find relocated block of lowest level
2012 static noinline_for_stack
2013 int walk_down_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
2016 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
2017 struct extent_buffer
*eb
= NULL
;
2024 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
2026 for (i
= *level
; i
> 0; i
--) {
2027 struct btrfs_key first_key
;
2029 eb
= path
->nodes
[i
];
2030 nritems
= btrfs_header_nritems(eb
);
2031 while (path
->slots
[i
] < nritems
) {
2032 ptr_gen
= btrfs_node_ptr_generation(eb
, path
->slots
[i
]);
2033 if (ptr_gen
> last_snapshot
)
2037 if (path
->slots
[i
] >= nritems
) {
2048 bytenr
= btrfs_node_blockptr(eb
, path
->slots
[i
]);
2049 btrfs_node_key_to_cpu(eb
, &first_key
, path
->slots
[i
]);
2050 eb
= read_tree_block(fs_info
, bytenr
, ptr_gen
, i
- 1,
2054 } else if (!extent_buffer_uptodate(eb
)) {
2055 free_extent_buffer(eb
);
2058 BUG_ON(btrfs_header_level(eb
) != i
- 1);
2059 path
->nodes
[i
- 1] = eb
;
2060 path
->slots
[i
- 1] = 0;
2066 * invalidate extent cache for file extents whose key in range of
2067 * [min_key, max_key)
2069 static int invalidate_extent_cache(struct btrfs_root
*root
,
2070 struct btrfs_key
*min_key
,
2071 struct btrfs_key
*max_key
)
2073 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
2074 struct inode
*inode
= NULL
;
2079 objectid
= min_key
->objectid
;
2084 if (objectid
> max_key
->objectid
)
2087 inode
= find_next_inode(root
, objectid
);
2090 ino
= btrfs_ino(BTRFS_I(inode
));
2092 if (ino
> max_key
->objectid
) {
2098 if (!S_ISREG(inode
->i_mode
))
2101 if (unlikely(min_key
->objectid
== ino
)) {
2102 if (min_key
->type
> BTRFS_EXTENT_DATA_KEY
)
2104 if (min_key
->type
< BTRFS_EXTENT_DATA_KEY
)
2107 start
= min_key
->offset
;
2108 WARN_ON(!IS_ALIGNED(start
, fs_info
->sectorsize
));
2114 if (unlikely(max_key
->objectid
== ino
)) {
2115 if (max_key
->type
< BTRFS_EXTENT_DATA_KEY
)
2117 if (max_key
->type
> BTRFS_EXTENT_DATA_KEY
) {
2120 if (max_key
->offset
== 0)
2122 end
= max_key
->offset
;
2123 WARN_ON(!IS_ALIGNED(end
, fs_info
->sectorsize
));
2130 /* the lock_extent waits for readpage to complete */
2131 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2132 btrfs_drop_extent_cache(BTRFS_I(inode
), start
, end
, 1);
2133 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2138 static int find_next_key(struct btrfs_path
*path
, int level
,
2139 struct btrfs_key
*key
)
2142 while (level
< BTRFS_MAX_LEVEL
) {
2143 if (!path
->nodes
[level
])
2145 if (path
->slots
[level
] + 1 <
2146 btrfs_header_nritems(path
->nodes
[level
])) {
2147 btrfs_node_key_to_cpu(path
->nodes
[level
], key
,
2148 path
->slots
[level
] + 1);
2157 * Insert current subvolume into reloc_control::dirty_subvol_roots
2159 static void insert_dirty_subvol(struct btrfs_trans_handle
*trans
,
2160 struct reloc_control
*rc
,
2161 struct btrfs_root
*root
)
2163 struct btrfs_root
*reloc_root
= root
->reloc_root
;
2164 struct btrfs_root_item
*reloc_root_item
;
2166 /* @root must be a subvolume tree root with a valid reloc tree */
2167 ASSERT(root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
);
2170 reloc_root_item
= &reloc_root
->root_item
;
2171 memset(&reloc_root_item
->drop_progress
, 0,
2172 sizeof(reloc_root_item
->drop_progress
));
2173 reloc_root_item
->drop_level
= 0;
2174 btrfs_set_root_refs(reloc_root_item
, 0);
2175 btrfs_update_reloc_root(trans
, root
);
2177 if (list_empty(&root
->reloc_dirty_list
)) {
2178 btrfs_grab_fs_root(root
);
2179 list_add_tail(&root
->reloc_dirty_list
, &rc
->dirty_subvol_roots
);
2183 static int clean_dirty_subvols(struct reloc_control
*rc
)
2185 struct btrfs_root
*root
;
2186 struct btrfs_root
*next
;
2190 list_for_each_entry_safe(root
, next
, &rc
->dirty_subvol_roots
,
2192 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
) {
2193 /* Merged subvolume, cleanup its reloc root */
2194 struct btrfs_root
*reloc_root
= root
->reloc_root
;
2196 list_del_init(&root
->reloc_dirty_list
);
2197 root
->reloc_root
= NULL
;
2200 ret2
= btrfs_drop_snapshot(reloc_root
, NULL
, 0, 1);
2201 if (ret2
< 0 && !ret
)
2204 clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE
, &root
->state
);
2205 btrfs_put_fs_root(root
);
2207 /* Orphan reloc tree, just clean it up */
2208 ret2
= btrfs_drop_snapshot(root
, NULL
, 0, 1);
2209 if (ret2
< 0 && !ret
)
2217 * merge the relocated tree blocks in reloc tree with corresponding
2220 static noinline_for_stack
int merge_reloc_root(struct reloc_control
*rc
,
2221 struct btrfs_root
*root
)
2223 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
2224 struct btrfs_key key
;
2225 struct btrfs_key next_key
;
2226 struct btrfs_trans_handle
*trans
= NULL
;
2227 struct btrfs_root
*reloc_root
;
2228 struct btrfs_root_item
*root_item
;
2229 struct btrfs_path
*path
;
2230 struct extent_buffer
*leaf
;
2238 path
= btrfs_alloc_path();
2241 path
->reada
= READA_FORWARD
;
2243 reloc_root
= root
->reloc_root
;
2244 root_item
= &reloc_root
->root_item
;
2246 if (btrfs_disk_key_objectid(&root_item
->drop_progress
) == 0) {
2247 level
= btrfs_root_level(root_item
);
2248 atomic_inc(&reloc_root
->node
->refs
);
2249 path
->nodes
[level
] = reloc_root
->node
;
2250 path
->slots
[level
] = 0;
2252 btrfs_disk_key_to_cpu(&key
, &root_item
->drop_progress
);
2254 level
= root_item
->drop_level
;
2256 path
->lowest_level
= level
;
2257 ret
= btrfs_search_slot(NULL
, reloc_root
, &key
, path
, 0, 0);
2258 path
->lowest_level
= 0;
2260 btrfs_free_path(path
);
2264 btrfs_node_key_to_cpu(path
->nodes
[level
], &next_key
,
2265 path
->slots
[level
]);
2266 WARN_ON(memcmp(&key
, &next_key
, sizeof(key
)));
2268 btrfs_unlock_up_safe(path
, 0);
2271 min_reserved
= fs_info
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2272 memset(&next_key
, 0, sizeof(next_key
));
2275 ret
= btrfs_block_rsv_refill(root
, rc
->block_rsv
, min_reserved
,
2276 BTRFS_RESERVE_FLUSH_ALL
);
2281 trans
= btrfs_start_transaction(root
, 0);
2282 if (IS_ERR(trans
)) {
2283 err
= PTR_ERR(trans
);
2287 trans
->block_rsv
= rc
->block_rsv
;
2292 ret
= walk_down_reloc_tree(reloc_root
, path
, &level
);
2300 if (!find_next_key(path
, level
, &key
) &&
2301 btrfs_comp_cpu_keys(&next_key
, &key
) >= 0) {
2304 ret
= replace_path(trans
, rc
, root
, reloc_root
, path
,
2305 &next_key
, level
, max_level
);
2314 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
2315 path
->slots
[level
]);
2319 ret
= walk_up_reloc_tree(reloc_root
, path
, &level
);
2325 * save the merging progress in the drop_progress.
2326 * this is OK since root refs == 1 in this case.
2328 btrfs_node_key(path
->nodes
[level
], &root_item
->drop_progress
,
2329 path
->slots
[level
]);
2330 root_item
->drop_level
= level
;
2332 btrfs_end_transaction_throttle(trans
);
2335 btrfs_btree_balance_dirty(fs_info
);
2337 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2338 invalidate_extent_cache(root
, &key
, &next_key
);
2342 * handle the case only one block in the fs tree need to be
2343 * relocated and the block is tree root.
2345 leaf
= btrfs_lock_root_node(root
);
2346 ret
= btrfs_cow_block(trans
, root
, leaf
, NULL
, 0, &leaf
);
2347 btrfs_tree_unlock(leaf
);
2348 free_extent_buffer(leaf
);
2352 btrfs_free_path(path
);
2355 insert_dirty_subvol(trans
, rc
, root
);
2358 btrfs_end_transaction_throttle(trans
);
2360 btrfs_btree_balance_dirty(fs_info
);
2362 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
2363 invalidate_extent_cache(root
, &key
, &next_key
);
2368 static noinline_for_stack
2369 int prepare_to_merge(struct reloc_control
*rc
, int err
)
2371 struct btrfs_root
*root
= rc
->extent_root
;
2372 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
2373 struct btrfs_root
*reloc_root
;
2374 struct btrfs_trans_handle
*trans
;
2375 LIST_HEAD(reloc_roots
);
2379 mutex_lock(&fs_info
->reloc_mutex
);
2380 rc
->merging_rsv_size
+= fs_info
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
2381 rc
->merging_rsv_size
+= rc
->nodes_relocated
* 2;
2382 mutex_unlock(&fs_info
->reloc_mutex
);
2386 num_bytes
= rc
->merging_rsv_size
;
2387 ret
= btrfs_block_rsv_add(root
, rc
->block_rsv
, num_bytes
,
2388 BTRFS_RESERVE_FLUSH_ALL
);
2393 trans
= btrfs_join_transaction(rc
->extent_root
);
2394 if (IS_ERR(trans
)) {
2396 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
,
2398 return PTR_ERR(trans
);
2402 if (num_bytes
!= rc
->merging_rsv_size
) {
2403 btrfs_end_transaction(trans
);
2404 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
,
2410 rc
->merge_reloc_tree
= 1;
2412 while (!list_empty(&rc
->reloc_roots
)) {
2413 reloc_root
= list_entry(rc
->reloc_roots
.next
,
2414 struct btrfs_root
, root_list
);
2415 list_del_init(&reloc_root
->root_list
);
2417 root
= read_fs_root(fs_info
, reloc_root
->root_key
.offset
);
2418 BUG_ON(IS_ERR(root
));
2419 BUG_ON(root
->reloc_root
!= reloc_root
);
2422 * set reference count to 1, so btrfs_recover_relocation
2423 * knows it should resumes merging
2426 btrfs_set_root_refs(&reloc_root
->root_item
, 1);
2427 btrfs_update_reloc_root(trans
, root
);
2429 list_add(&reloc_root
->root_list
, &reloc_roots
);
2432 list_splice(&reloc_roots
, &rc
->reloc_roots
);
2435 btrfs_commit_transaction(trans
);
2437 btrfs_end_transaction(trans
);
2441 static noinline_for_stack
2442 void free_reloc_roots(struct list_head
*list
)
2444 struct btrfs_root
*reloc_root
;
2446 while (!list_empty(list
)) {
2447 reloc_root
= list_entry(list
->next
, struct btrfs_root
,
2449 __del_reloc_root(reloc_root
);
2450 free_extent_buffer(reloc_root
->node
);
2451 free_extent_buffer(reloc_root
->commit_root
);
2452 reloc_root
->node
= NULL
;
2453 reloc_root
->commit_root
= NULL
;
2457 static noinline_for_stack
2458 void merge_reloc_roots(struct reloc_control
*rc
)
2460 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
2461 struct btrfs_root
*root
;
2462 struct btrfs_root
*reloc_root
;
2463 LIST_HEAD(reloc_roots
);
2467 root
= rc
->extent_root
;
2470 * this serializes us with btrfs_record_root_in_transaction,
2471 * we have to make sure nobody is in the middle of
2472 * adding their roots to the list while we are
2475 mutex_lock(&fs_info
->reloc_mutex
);
2476 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
2477 mutex_unlock(&fs_info
->reloc_mutex
);
2479 while (!list_empty(&reloc_roots
)) {
2481 reloc_root
= list_entry(reloc_roots
.next
,
2482 struct btrfs_root
, root_list
);
2484 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
2485 root
= read_fs_root(fs_info
,
2486 reloc_root
->root_key
.offset
);
2487 BUG_ON(IS_ERR(root
));
2488 BUG_ON(root
->reloc_root
!= reloc_root
);
2490 ret
= merge_reloc_root(rc
, root
);
2492 if (list_empty(&reloc_root
->root_list
))
2493 list_add_tail(&reloc_root
->root_list
,
2498 list_del_init(&reloc_root
->root_list
);
2499 /* Don't forget to queue this reloc root for cleanup */
2500 list_add_tail(&reloc_root
->reloc_dirty_list
,
2501 &rc
->dirty_subvol_roots
);
2511 btrfs_handle_fs_error(fs_info
, ret
, NULL
);
2512 if (!list_empty(&reloc_roots
))
2513 free_reloc_roots(&reloc_roots
);
2515 /* new reloc root may be added */
2516 mutex_lock(&fs_info
->reloc_mutex
);
2517 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
2518 mutex_unlock(&fs_info
->reloc_mutex
);
2519 if (!list_empty(&reloc_roots
))
2520 free_reloc_roots(&reloc_roots
);
2523 BUG_ON(!RB_EMPTY_ROOT(&rc
->reloc_root_tree
.rb_root
));
2526 static void free_block_list(struct rb_root
*blocks
)
2528 struct tree_block
*block
;
2529 struct rb_node
*rb_node
;
2530 while ((rb_node
= rb_first(blocks
))) {
2531 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
2532 rb_erase(rb_node
, blocks
);
2537 static int record_reloc_root_in_trans(struct btrfs_trans_handle
*trans
,
2538 struct btrfs_root
*reloc_root
)
2540 struct btrfs_fs_info
*fs_info
= reloc_root
->fs_info
;
2541 struct btrfs_root
*root
;
2543 if (reloc_root
->last_trans
== trans
->transid
)
2546 root
= read_fs_root(fs_info
, reloc_root
->root_key
.offset
);
2547 BUG_ON(IS_ERR(root
));
2548 BUG_ON(root
->reloc_root
!= reloc_root
);
2550 return btrfs_record_root_in_trans(trans
, root
);
2553 static noinline_for_stack
2554 struct btrfs_root
*select_reloc_root(struct btrfs_trans_handle
*trans
,
2555 struct reloc_control
*rc
,
2556 struct backref_node
*node
,
2557 struct backref_edge
*edges
[])
2559 struct backref_node
*next
;
2560 struct btrfs_root
*root
;
2566 next
= walk_up_backref(next
, edges
, &index
);
2569 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
));
2571 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
2572 record_reloc_root_in_trans(trans
, root
);
2576 btrfs_record_root_in_trans(trans
, root
);
2577 root
= root
->reloc_root
;
2579 if (next
->new_bytenr
!= root
->node
->start
) {
2580 BUG_ON(next
->new_bytenr
);
2581 BUG_ON(!list_empty(&next
->list
));
2582 next
->new_bytenr
= root
->node
->start
;
2584 list_add_tail(&next
->list
,
2585 &rc
->backref_cache
.changed
);
2586 __mark_block_processed(rc
, next
);
2592 next
= walk_down_backref(edges
, &index
);
2593 if (!next
|| next
->level
<= node
->level
)
2600 /* setup backref node path for btrfs_reloc_cow_block */
2602 rc
->backref_cache
.path
[next
->level
] = next
;
2605 next
= edges
[index
]->node
[UPPER
];
2611 * select a tree root for relocation. return NULL if the block
2612 * is reference counted. we should use do_relocation() in this
2613 * case. return a tree root pointer if the block isn't reference
2614 * counted. return -ENOENT if the block is root of reloc tree.
2616 static noinline_for_stack
2617 struct btrfs_root
*select_one_root(struct backref_node
*node
)
2619 struct backref_node
*next
;
2620 struct btrfs_root
*root
;
2621 struct btrfs_root
*fs_root
= NULL
;
2622 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2628 next
= walk_up_backref(next
, edges
, &index
);
2632 /* no other choice for non-references counted tree */
2633 if (!test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
))
2636 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
)
2642 next
= walk_down_backref(edges
, &index
);
2643 if (!next
|| next
->level
<= node
->level
)
2648 return ERR_PTR(-ENOENT
);
2652 static noinline_for_stack
2653 u64
calcu_metadata_size(struct reloc_control
*rc
,
2654 struct backref_node
*node
, int reserve
)
2656 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
2657 struct backref_node
*next
= node
;
2658 struct backref_edge
*edge
;
2659 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2663 BUG_ON(reserve
&& node
->processed
);
2668 if (next
->processed
&& (reserve
|| next
!= node
))
2671 num_bytes
+= fs_info
->nodesize
;
2673 if (list_empty(&next
->upper
))
2676 edge
= list_entry(next
->upper
.next
,
2677 struct backref_edge
, list
[LOWER
]);
2678 edges
[index
++] = edge
;
2679 next
= edge
->node
[UPPER
];
2681 next
= walk_down_backref(edges
, &index
);
2686 static int reserve_metadata_space(struct btrfs_trans_handle
*trans
,
2687 struct reloc_control
*rc
,
2688 struct backref_node
*node
)
2690 struct btrfs_root
*root
= rc
->extent_root
;
2691 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
2696 num_bytes
= calcu_metadata_size(rc
, node
, 1) * 2;
2698 trans
->block_rsv
= rc
->block_rsv
;
2699 rc
->reserved_bytes
+= num_bytes
;
2702 * We are under a transaction here so we can only do limited flushing.
2703 * If we get an enospc just kick back -EAGAIN so we know to drop the
2704 * transaction and try to refill when we can flush all the things.
2706 ret
= btrfs_block_rsv_refill(root
, rc
->block_rsv
, num_bytes
,
2707 BTRFS_RESERVE_FLUSH_LIMIT
);
2709 tmp
= fs_info
->nodesize
* RELOCATION_RESERVED_NODES
;
2710 while (tmp
<= rc
->reserved_bytes
)
2713 * only one thread can access block_rsv at this point,
2714 * so we don't need hold lock to protect block_rsv.
2715 * we expand more reservation size here to allow enough
2716 * space for relocation and we will return earlier in
2719 rc
->block_rsv
->size
= tmp
+ fs_info
->nodesize
*
2720 RELOCATION_RESERVED_NODES
;
2728 * relocate a block tree, and then update pointers in upper level
2729 * blocks that reference the block to point to the new location.
2731 * if called by link_to_upper, the block has already been relocated.
2732 * in that case this function just updates pointers.
2734 static int do_relocation(struct btrfs_trans_handle
*trans
,
2735 struct reloc_control
*rc
,
2736 struct backref_node
*node
,
2737 struct btrfs_key
*key
,
2738 struct btrfs_path
*path
, int lowest
)
2740 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
2741 struct backref_node
*upper
;
2742 struct backref_edge
*edge
;
2743 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2744 struct btrfs_root
*root
;
2745 struct extent_buffer
*eb
;
2753 BUG_ON(lowest
&& node
->eb
);
2755 path
->lowest_level
= node
->level
+ 1;
2756 rc
->backref_cache
.path
[node
->level
] = node
;
2757 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
]) {
2758 struct btrfs_key first_key
;
2759 struct btrfs_ref ref
= { 0 };
2763 upper
= edge
->node
[UPPER
];
2764 root
= select_reloc_root(trans
, rc
, upper
, edges
);
2767 if (upper
->eb
&& !upper
->locked
) {
2769 ret
= btrfs_bin_search(upper
->eb
, key
,
2770 upper
->level
, &slot
);
2776 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2777 if (node
->eb
->start
== bytenr
)
2780 drop_node_buffer(upper
);
2784 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2791 btrfs_release_path(path
);
2796 upper
->eb
= path
->nodes
[upper
->level
];
2797 path
->nodes
[upper
->level
] = NULL
;
2799 BUG_ON(upper
->eb
!= path
->nodes
[upper
->level
]);
2803 path
->locks
[upper
->level
] = 0;
2805 slot
= path
->slots
[upper
->level
];
2806 btrfs_release_path(path
);
2808 ret
= btrfs_bin_search(upper
->eb
, key
, upper
->level
,
2817 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2819 if (bytenr
!= node
->bytenr
) {
2820 btrfs_err(root
->fs_info
,
2821 "lowest leaf/node mismatch: bytenr %llu node->bytenr %llu slot %d upper %llu",
2822 bytenr
, node
->bytenr
, slot
,
2828 if (node
->eb
->start
== bytenr
)
2832 blocksize
= root
->fs_info
->nodesize
;
2833 generation
= btrfs_node_ptr_generation(upper
->eb
, slot
);
2834 btrfs_node_key_to_cpu(upper
->eb
, &first_key
, slot
);
2835 eb
= read_tree_block(fs_info
, bytenr
, generation
,
2836 upper
->level
- 1, &first_key
);
2840 } else if (!extent_buffer_uptodate(eb
)) {
2841 free_extent_buffer(eb
);
2845 btrfs_tree_lock(eb
);
2846 btrfs_set_lock_blocking_write(eb
);
2849 ret
= btrfs_cow_block(trans
, root
, eb
, upper
->eb
,
2851 btrfs_tree_unlock(eb
);
2852 free_extent_buffer(eb
);
2857 BUG_ON(node
->eb
!= eb
);
2859 btrfs_set_node_blockptr(upper
->eb
, slot
,
2861 btrfs_set_node_ptr_generation(upper
->eb
, slot
,
2863 btrfs_mark_buffer_dirty(upper
->eb
);
2865 btrfs_init_generic_ref(&ref
, BTRFS_ADD_DELAYED_REF
,
2866 node
->eb
->start
, blocksize
,
2868 ref
.real_root
= root
->root_key
.objectid
;
2869 btrfs_init_tree_ref(&ref
, node
->level
,
2870 btrfs_header_owner(upper
->eb
));
2871 ret
= btrfs_inc_extent_ref(trans
, &ref
);
2874 ret
= btrfs_drop_subtree(trans
, root
, eb
, upper
->eb
);
2878 if (!upper
->pending
)
2879 drop_node_buffer(upper
);
2881 unlock_node_buffer(upper
);
2886 if (!err
&& node
->pending
) {
2887 drop_node_buffer(node
);
2888 list_move_tail(&node
->list
, &rc
->backref_cache
.changed
);
2892 path
->lowest_level
= 0;
2893 BUG_ON(err
== -ENOSPC
);
2897 static int link_to_upper(struct btrfs_trans_handle
*trans
,
2898 struct reloc_control
*rc
,
2899 struct backref_node
*node
,
2900 struct btrfs_path
*path
)
2902 struct btrfs_key key
;
2904 btrfs_node_key_to_cpu(node
->eb
, &key
, 0);
2905 return do_relocation(trans
, rc
, node
, &key
, path
, 0);
2908 static int finish_pending_nodes(struct btrfs_trans_handle
*trans
,
2909 struct reloc_control
*rc
,
2910 struct btrfs_path
*path
, int err
)
2913 struct backref_cache
*cache
= &rc
->backref_cache
;
2914 struct backref_node
*node
;
2918 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
2919 while (!list_empty(&cache
->pending
[level
])) {
2920 node
= list_entry(cache
->pending
[level
].next
,
2921 struct backref_node
, list
);
2922 list_move_tail(&node
->list
, &list
);
2923 BUG_ON(!node
->pending
);
2926 ret
= link_to_upper(trans
, rc
, node
, path
);
2931 list_splice_init(&list
, &cache
->pending
[level
]);
2936 static void mark_block_processed(struct reloc_control
*rc
,
2937 u64 bytenr
, u32 blocksize
)
2939 set_extent_bits(&rc
->processed_blocks
, bytenr
, bytenr
+ blocksize
- 1,
2943 static void __mark_block_processed(struct reloc_control
*rc
,
2944 struct backref_node
*node
)
2947 if (node
->level
== 0 ||
2948 in_block_group(node
->bytenr
, rc
->block_group
)) {
2949 blocksize
= rc
->extent_root
->fs_info
->nodesize
;
2950 mark_block_processed(rc
, node
->bytenr
, blocksize
);
2952 node
->processed
= 1;
2956 * mark a block and all blocks directly/indirectly reference the block
2959 static void update_processed_blocks(struct reloc_control
*rc
,
2960 struct backref_node
*node
)
2962 struct backref_node
*next
= node
;
2963 struct backref_edge
*edge
;
2964 struct backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2970 if (next
->processed
)
2973 __mark_block_processed(rc
, next
);
2975 if (list_empty(&next
->upper
))
2978 edge
= list_entry(next
->upper
.next
,
2979 struct backref_edge
, list
[LOWER
]);
2980 edges
[index
++] = edge
;
2981 next
= edge
->node
[UPPER
];
2983 next
= walk_down_backref(edges
, &index
);
2987 static int tree_block_processed(u64 bytenr
, struct reloc_control
*rc
)
2989 u32 blocksize
= rc
->extent_root
->fs_info
->nodesize
;
2991 if (test_range_bit(&rc
->processed_blocks
, bytenr
,
2992 bytenr
+ blocksize
- 1, EXTENT_DIRTY
, 1, NULL
))
2997 static int get_tree_block_key(struct btrfs_fs_info
*fs_info
,
2998 struct tree_block
*block
)
3000 struct extent_buffer
*eb
;
3002 BUG_ON(block
->key_ready
);
3003 eb
= read_tree_block(fs_info
, block
->bytenr
, block
->key
.offset
,
3004 block
->level
, NULL
);
3007 } else if (!extent_buffer_uptodate(eb
)) {
3008 free_extent_buffer(eb
);
3011 if (block
->level
== 0)
3012 btrfs_item_key_to_cpu(eb
, &block
->key
, 0);
3014 btrfs_node_key_to_cpu(eb
, &block
->key
, 0);
3015 free_extent_buffer(eb
);
3016 block
->key_ready
= 1;
3021 * helper function to relocate a tree block
3023 static int relocate_tree_block(struct btrfs_trans_handle
*trans
,
3024 struct reloc_control
*rc
,
3025 struct backref_node
*node
,
3026 struct btrfs_key
*key
,
3027 struct btrfs_path
*path
)
3029 struct btrfs_root
*root
;
3035 BUG_ON(node
->processed
);
3036 root
= select_one_root(node
);
3037 if (root
== ERR_PTR(-ENOENT
)) {
3038 update_processed_blocks(rc
, node
);
3042 if (!root
|| test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
)) {
3043 ret
= reserve_metadata_space(trans
, rc
, node
);
3049 if (test_bit(BTRFS_ROOT_REF_COWS
, &root
->state
)) {
3050 BUG_ON(node
->new_bytenr
);
3051 BUG_ON(!list_empty(&node
->list
));
3052 btrfs_record_root_in_trans(trans
, root
);
3053 root
= root
->reloc_root
;
3054 node
->new_bytenr
= root
->node
->start
;
3056 list_add_tail(&node
->list
, &rc
->backref_cache
.changed
);
3058 path
->lowest_level
= node
->level
;
3059 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
3060 btrfs_release_path(path
);
3065 update_processed_blocks(rc
, node
);
3067 ret
= do_relocation(trans
, rc
, node
, key
, path
, 1);
3070 if (ret
|| node
->level
== 0 || node
->cowonly
)
3071 remove_backref_node(&rc
->backref_cache
, node
);
3076 * relocate a list of blocks
3078 static noinline_for_stack
3079 int relocate_tree_blocks(struct btrfs_trans_handle
*trans
,
3080 struct reloc_control
*rc
, struct rb_root
*blocks
)
3082 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3083 struct backref_node
*node
;
3084 struct btrfs_path
*path
;
3085 struct tree_block
*block
;
3086 struct tree_block
*next
;
3090 path
= btrfs_alloc_path();
3093 goto out_free_blocks
;
3096 /* Kick in readahead for tree blocks with missing keys */
3097 rbtree_postorder_for_each_entry_safe(block
, next
, blocks
, rb_node
) {
3098 if (!block
->key_ready
)
3099 readahead_tree_block(fs_info
, block
->bytenr
);
3102 /* Get first keys */
3103 rbtree_postorder_for_each_entry_safe(block
, next
, blocks
, rb_node
) {
3104 if (!block
->key_ready
) {
3105 err
= get_tree_block_key(fs_info
, block
);
3111 /* Do tree relocation */
3112 rbtree_postorder_for_each_entry_safe(block
, next
, blocks
, rb_node
) {
3113 node
= build_backref_tree(rc
, &block
->key
,
3114 block
->level
, block
->bytenr
);
3116 err
= PTR_ERR(node
);
3120 ret
= relocate_tree_block(trans
, rc
, node
, &block
->key
,
3123 if (ret
!= -EAGAIN
|| &block
->rb_node
== rb_first(blocks
))
3129 err
= finish_pending_nodes(trans
, rc
, path
, err
);
3132 btrfs_free_path(path
);
3134 free_block_list(blocks
);
3138 static noinline_for_stack
3139 int prealloc_file_extent_cluster(struct inode
*inode
,
3140 struct file_extent_cluster
*cluster
)
3145 u64 offset
= BTRFS_I(inode
)->index_cnt
;
3149 u64 prealloc_start
= cluster
->start
- offset
;
3150 u64 prealloc_end
= cluster
->end
- offset
;
3152 struct extent_changeset
*data_reserved
= NULL
;
3154 BUG_ON(cluster
->start
!= cluster
->boundary
[0]);
3157 ret
= btrfs_check_data_free_space(inode
, &data_reserved
, prealloc_start
,
3158 prealloc_end
+ 1 - prealloc_start
);
3162 cur_offset
= prealloc_start
;
3163 while (nr
< cluster
->nr
) {
3164 start
= cluster
->boundary
[nr
] - offset
;
3165 if (nr
+ 1 < cluster
->nr
)
3166 end
= cluster
->boundary
[nr
+ 1] - 1 - offset
;
3168 end
= cluster
->end
- offset
;
3170 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3171 num_bytes
= end
+ 1 - start
;
3172 if (cur_offset
< start
)
3173 btrfs_free_reserved_data_space(inode
, data_reserved
,
3174 cur_offset
, start
- cur_offset
);
3175 ret
= btrfs_prealloc_file_range(inode
, 0, start
,
3176 num_bytes
, num_bytes
,
3177 end
+ 1, &alloc_hint
);
3178 cur_offset
= end
+ 1;
3179 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3184 if (cur_offset
< prealloc_end
)
3185 btrfs_free_reserved_data_space(inode
, data_reserved
,
3186 cur_offset
, prealloc_end
+ 1 - cur_offset
);
3188 inode_unlock(inode
);
3189 extent_changeset_free(data_reserved
);
3193 static noinline_for_stack
3194 int setup_extent_mapping(struct inode
*inode
, u64 start
, u64 end
,
3197 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
3198 struct extent_map
*em
;
3201 em
= alloc_extent_map();
3206 em
->len
= end
+ 1 - start
;
3207 em
->block_len
= em
->len
;
3208 em
->block_start
= block_start
;
3209 set_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
3211 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3213 write_lock(&em_tree
->lock
);
3214 ret
= add_extent_mapping(em_tree
, em
, 0);
3215 write_unlock(&em_tree
->lock
);
3216 if (ret
!= -EEXIST
) {
3217 free_extent_map(em
);
3220 btrfs_drop_extent_cache(BTRFS_I(inode
), start
, end
, 0);
3222 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
3226 static int relocate_file_extent_cluster(struct inode
*inode
,
3227 struct file_extent_cluster
*cluster
)
3229 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
3232 u64 offset
= BTRFS_I(inode
)->index_cnt
;
3233 unsigned long index
;
3234 unsigned long last_index
;
3236 struct file_ra_state
*ra
;
3237 gfp_t mask
= btrfs_alloc_write_mask(inode
->i_mapping
);
3244 ra
= kzalloc(sizeof(*ra
), GFP_NOFS
);
3248 ret
= prealloc_file_extent_cluster(inode
, cluster
);
3252 file_ra_state_init(ra
, inode
->i_mapping
);
3254 ret
= setup_extent_mapping(inode
, cluster
->start
- offset
,
3255 cluster
->end
- offset
, cluster
->start
);
3259 index
= (cluster
->start
- offset
) >> PAGE_SHIFT
;
3260 last_index
= (cluster
->end
- offset
) >> PAGE_SHIFT
;
3261 while (index
<= last_index
) {
3262 ret
= btrfs_delalloc_reserve_metadata(BTRFS_I(inode
),
3267 page
= find_lock_page(inode
->i_mapping
, index
);
3269 page_cache_sync_readahead(inode
->i_mapping
,
3271 last_index
+ 1 - index
);
3272 page
= find_or_create_page(inode
->i_mapping
, index
,
3275 btrfs_delalloc_release_metadata(BTRFS_I(inode
),
3277 btrfs_delalloc_release_extents(BTRFS_I(inode
),
3284 if (PageReadahead(page
)) {
3285 page_cache_async_readahead(inode
->i_mapping
,
3286 ra
, NULL
, page
, index
,
3287 last_index
+ 1 - index
);
3290 if (!PageUptodate(page
)) {
3291 btrfs_readpage(NULL
, page
);
3293 if (!PageUptodate(page
)) {
3296 btrfs_delalloc_release_metadata(BTRFS_I(inode
),
3298 btrfs_delalloc_release_extents(BTRFS_I(inode
),
3305 page_start
= page_offset(page
);
3306 page_end
= page_start
+ PAGE_SIZE
- 1;
3308 lock_extent(&BTRFS_I(inode
)->io_tree
, page_start
, page_end
);
3310 set_page_extent_mapped(page
);
3312 if (nr
< cluster
->nr
&&
3313 page_start
+ offset
== cluster
->boundary
[nr
]) {
3314 set_extent_bits(&BTRFS_I(inode
)->io_tree
,
3315 page_start
, page_end
,
3320 ret
= btrfs_set_extent_delalloc(inode
, page_start
, page_end
, 0,
3325 btrfs_delalloc_release_metadata(BTRFS_I(inode
),
3327 btrfs_delalloc_release_extents(BTRFS_I(inode
),
3330 clear_extent_bits(&BTRFS_I(inode
)->io_tree
,
3331 page_start
, page_end
,
3332 EXTENT_LOCKED
| EXTENT_BOUNDARY
);
3336 set_page_dirty(page
);
3338 unlock_extent(&BTRFS_I(inode
)->io_tree
,
3339 page_start
, page_end
);
3344 btrfs_delalloc_release_extents(BTRFS_I(inode
), PAGE_SIZE
);
3345 balance_dirty_pages_ratelimited(inode
->i_mapping
);
3346 btrfs_throttle(fs_info
);
3348 WARN_ON(nr
!= cluster
->nr
);
3354 static noinline_for_stack
3355 int relocate_data_extent(struct inode
*inode
, struct btrfs_key
*extent_key
,
3356 struct file_extent_cluster
*cluster
)
3360 if (cluster
->nr
> 0 && extent_key
->objectid
!= cluster
->end
+ 1) {
3361 ret
= relocate_file_extent_cluster(inode
, cluster
);
3368 cluster
->start
= extent_key
->objectid
;
3370 BUG_ON(cluster
->nr
>= MAX_EXTENTS
);
3371 cluster
->end
= extent_key
->objectid
+ extent_key
->offset
- 1;
3372 cluster
->boundary
[cluster
->nr
] = extent_key
->objectid
;
3375 if (cluster
->nr
>= MAX_EXTENTS
) {
3376 ret
= relocate_file_extent_cluster(inode
, cluster
);
3385 * helper to add a tree block to the list.
3386 * the major work is getting the generation and level of the block
3388 static int add_tree_block(struct reloc_control
*rc
,
3389 struct btrfs_key
*extent_key
,
3390 struct btrfs_path
*path
,
3391 struct rb_root
*blocks
)
3393 struct extent_buffer
*eb
;
3394 struct btrfs_extent_item
*ei
;
3395 struct btrfs_tree_block_info
*bi
;
3396 struct tree_block
*block
;
3397 struct rb_node
*rb_node
;
3402 eb
= path
->nodes
[0];
3403 item_size
= btrfs_item_size_nr(eb
, path
->slots
[0]);
3405 if (extent_key
->type
== BTRFS_METADATA_ITEM_KEY
||
3406 item_size
>= sizeof(*ei
) + sizeof(*bi
)) {
3407 ei
= btrfs_item_ptr(eb
, path
->slots
[0],
3408 struct btrfs_extent_item
);
3409 if (extent_key
->type
== BTRFS_EXTENT_ITEM_KEY
) {
3410 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
3411 level
= btrfs_tree_block_level(eb
, bi
);
3413 level
= (int)extent_key
->offset
;
3415 generation
= btrfs_extent_generation(eb
, ei
);
3416 } else if (unlikely(item_size
== sizeof(struct btrfs_extent_item_v0
))) {
3417 btrfs_print_v0_err(eb
->fs_info
);
3418 btrfs_handle_fs_error(eb
->fs_info
, -EINVAL
, NULL
);
3424 btrfs_release_path(path
);
3426 BUG_ON(level
== -1);
3428 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3432 block
->bytenr
= extent_key
->objectid
;
3433 block
->key
.objectid
= rc
->extent_root
->fs_info
->nodesize
;
3434 block
->key
.offset
= generation
;
3435 block
->level
= level
;
3436 block
->key_ready
= 0;
3438 rb_node
= tree_insert(blocks
, block
->bytenr
, &block
->rb_node
);
3440 backref_tree_panic(rb_node
, -EEXIST
, block
->bytenr
);
3446 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3448 static int __add_tree_block(struct reloc_control
*rc
,
3449 u64 bytenr
, u32 blocksize
,
3450 struct rb_root
*blocks
)
3452 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3453 struct btrfs_path
*path
;
3454 struct btrfs_key key
;
3456 bool skinny
= btrfs_fs_incompat(fs_info
, SKINNY_METADATA
);
3458 if (tree_block_processed(bytenr
, rc
))
3461 if (tree_search(blocks
, bytenr
))
3464 path
= btrfs_alloc_path();
3468 key
.objectid
= bytenr
;
3470 key
.type
= BTRFS_METADATA_ITEM_KEY
;
3471 key
.offset
= (u64
)-1;
3473 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3474 key
.offset
= blocksize
;
3477 path
->search_commit_root
= 1;
3478 path
->skip_locking
= 1;
3479 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
, 0, 0);
3483 if (ret
> 0 && skinny
) {
3484 if (path
->slots
[0]) {
3486 btrfs_item_key_to_cpu(path
->nodes
[0], &key
,
3488 if (key
.objectid
== bytenr
&&
3489 (key
.type
== BTRFS_METADATA_ITEM_KEY
||
3490 (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
3491 key
.offset
== blocksize
)))
3497 btrfs_release_path(path
);
3503 btrfs_print_leaf(path
->nodes
[0]);
3505 "tree block extent item (%llu) is not found in extent tree",
3512 ret
= add_tree_block(rc
, &key
, path
, blocks
);
3514 btrfs_free_path(path
);
3519 * helper to check if the block use full backrefs for pointers in it
3521 static int block_use_full_backref(struct reloc_control
*rc
,
3522 struct extent_buffer
*eb
)
3527 if (btrfs_header_flag(eb
, BTRFS_HEADER_FLAG_RELOC
) ||
3528 btrfs_header_backref_rev(eb
) < BTRFS_MIXED_BACKREF_REV
)
3531 ret
= btrfs_lookup_extent_info(NULL
, rc
->extent_root
->fs_info
,
3532 eb
->start
, btrfs_header_level(eb
), 1,
3536 if (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
)
3543 static int delete_block_group_cache(struct btrfs_fs_info
*fs_info
,
3544 struct btrfs_block_group
*block_group
,
3545 struct inode
*inode
,
3548 struct btrfs_key key
;
3549 struct btrfs_root
*root
= fs_info
->tree_root
;
3550 struct btrfs_trans_handle
*trans
;
3557 key
.type
= BTRFS_INODE_ITEM_KEY
;
3560 inode
= btrfs_iget(fs_info
->sb
, &key
, root
);
3565 ret
= btrfs_check_trunc_cache_free_space(fs_info
,
3566 &fs_info
->global_block_rsv
);
3570 trans
= btrfs_join_transaction(root
);
3571 if (IS_ERR(trans
)) {
3572 ret
= PTR_ERR(trans
);
3576 ret
= btrfs_truncate_free_space_cache(trans
, block_group
, inode
);
3578 btrfs_end_transaction(trans
);
3579 btrfs_btree_balance_dirty(fs_info
);
3586 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3587 * this function scans fs tree to find blocks reference the data extent
3589 static int find_data_references(struct reloc_control
*rc
,
3590 struct btrfs_key
*extent_key
,
3591 struct extent_buffer
*leaf
,
3592 struct btrfs_extent_data_ref
*ref
,
3593 struct rb_root
*blocks
)
3595 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3596 struct btrfs_path
*path
;
3597 struct tree_block
*block
;
3598 struct btrfs_root
*root
;
3599 struct btrfs_file_extent_item
*fi
;
3600 struct rb_node
*rb_node
;
3601 struct btrfs_key key
;
3612 ref_root
= btrfs_extent_data_ref_root(leaf
, ref
);
3613 ref_objectid
= btrfs_extent_data_ref_objectid(leaf
, ref
);
3614 ref_offset
= btrfs_extent_data_ref_offset(leaf
, ref
);
3615 ref_count
= btrfs_extent_data_ref_count(leaf
, ref
);
3618 * This is an extent belonging to the free space cache, lets just delete
3619 * it and redo the search.
3621 if (ref_root
== BTRFS_ROOT_TREE_OBJECTID
) {
3622 ret
= delete_block_group_cache(fs_info
, rc
->block_group
,
3623 NULL
, ref_objectid
);
3629 path
= btrfs_alloc_path();
3632 path
->reada
= READA_FORWARD
;
3634 root
= read_fs_root(fs_info
, ref_root
);
3636 err
= PTR_ERR(root
);
3640 key
.objectid
= ref_objectid
;
3641 key
.type
= BTRFS_EXTENT_DATA_KEY
;
3642 if (ref_offset
> ((u64
)-1 << 32))
3645 key
.offset
= ref_offset
;
3647 path
->search_commit_root
= 1;
3648 path
->skip_locking
= 1;
3649 ret
= btrfs_search_slot(NULL
, root
, &key
, path
, 0, 0);
3655 leaf
= path
->nodes
[0];
3656 nritems
= btrfs_header_nritems(leaf
);
3658 * the references in tree blocks that use full backrefs
3659 * are not counted in
3661 if (block_use_full_backref(rc
, leaf
))
3665 rb_node
= tree_search(blocks
, leaf
->start
);
3670 path
->slots
[0] = nritems
;
3673 while (ref_count
> 0) {
3674 while (path
->slots
[0] >= nritems
) {
3675 ret
= btrfs_next_leaf(root
, path
);
3680 if (WARN_ON(ret
> 0))
3683 leaf
= path
->nodes
[0];
3684 nritems
= btrfs_header_nritems(leaf
);
3687 if (block_use_full_backref(rc
, leaf
))
3691 rb_node
= tree_search(blocks
, leaf
->start
);
3696 path
->slots
[0] = nritems
;
3700 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3701 if (WARN_ON(key
.objectid
!= ref_objectid
||
3702 key
.type
!= BTRFS_EXTENT_DATA_KEY
))
3705 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
3706 struct btrfs_file_extent_item
);
3708 if (btrfs_file_extent_type(leaf
, fi
) ==
3709 BTRFS_FILE_EXTENT_INLINE
)
3712 if (btrfs_file_extent_disk_bytenr(leaf
, fi
) !=
3713 extent_key
->objectid
)
3716 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
3717 if (key
.offset
!= ref_offset
)
3725 if (!tree_block_processed(leaf
->start
, rc
)) {
3726 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
3731 block
->bytenr
= leaf
->start
;
3732 btrfs_item_key_to_cpu(leaf
, &block
->key
, 0);
3734 block
->key_ready
= 1;
3735 rb_node
= tree_insert(blocks
, block
->bytenr
,
3738 backref_tree_panic(rb_node
, -EEXIST
,
3744 path
->slots
[0] = nritems
;
3750 btrfs_free_path(path
);
3755 * helper to find all tree blocks that reference a given data extent
3757 static noinline_for_stack
3758 int add_data_references(struct reloc_control
*rc
,
3759 struct btrfs_key
*extent_key
,
3760 struct btrfs_path
*path
,
3761 struct rb_root
*blocks
)
3763 struct btrfs_key key
;
3764 struct extent_buffer
*eb
;
3765 struct btrfs_extent_data_ref
*dref
;
3766 struct btrfs_extent_inline_ref
*iref
;
3769 u32 blocksize
= rc
->extent_root
->fs_info
->nodesize
;
3773 eb
= path
->nodes
[0];
3774 ptr
= btrfs_item_ptr_offset(eb
, path
->slots
[0]);
3775 end
= ptr
+ btrfs_item_size_nr(eb
, path
->slots
[0]);
3776 ptr
+= sizeof(struct btrfs_extent_item
);
3779 iref
= (struct btrfs_extent_inline_ref
*)ptr
;
3780 key
.type
= btrfs_get_extent_inline_ref_type(eb
, iref
,
3781 BTRFS_REF_TYPE_DATA
);
3782 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3783 key
.offset
= btrfs_extent_inline_ref_offset(eb
, iref
);
3784 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3786 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3787 dref
= (struct btrfs_extent_data_ref
*)(&iref
->offset
);
3788 ret
= find_data_references(rc
, extent_key
,
3792 btrfs_err(rc
->extent_root
->fs_info
,
3793 "extent %llu slot %d has an invalid inline ref type",
3794 eb
->start
, path
->slots
[0]);
3800 ptr
+= btrfs_extent_inline_ref_size(key
.type
);
3806 eb
= path
->nodes
[0];
3807 if (path
->slots
[0] >= btrfs_header_nritems(eb
)) {
3808 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3815 eb
= path
->nodes
[0];
3818 btrfs_item_key_to_cpu(eb
, &key
, path
->slots
[0]);
3819 if (key
.objectid
!= extent_key
->objectid
)
3822 if (key
.type
== BTRFS_SHARED_DATA_REF_KEY
) {
3823 ret
= __add_tree_block(rc
, key
.offset
, blocksize
,
3825 } else if (key
.type
== BTRFS_EXTENT_DATA_REF_KEY
) {
3826 dref
= btrfs_item_ptr(eb
, path
->slots
[0],
3827 struct btrfs_extent_data_ref
);
3828 ret
= find_data_references(rc
, extent_key
,
3830 } else if (unlikely(key
.type
== BTRFS_EXTENT_REF_V0_KEY
)) {
3831 btrfs_print_v0_err(eb
->fs_info
);
3832 btrfs_handle_fs_error(eb
->fs_info
, -EINVAL
, NULL
);
3844 btrfs_release_path(path
);
3846 free_block_list(blocks
);
3851 * helper to find next unprocessed extent
3853 static noinline_for_stack
3854 int find_next_extent(struct reloc_control
*rc
, struct btrfs_path
*path
,
3855 struct btrfs_key
*extent_key
)
3857 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3858 struct btrfs_key key
;
3859 struct extent_buffer
*leaf
;
3860 u64 start
, end
, last
;
3863 last
= rc
->block_group
->start
+ rc
->block_group
->length
;
3866 if (rc
->search_start
>= last
) {
3871 key
.objectid
= rc
->search_start
;
3872 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3875 path
->search_commit_root
= 1;
3876 path
->skip_locking
= 1;
3877 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
,
3882 leaf
= path
->nodes
[0];
3883 if (path
->slots
[0] >= btrfs_header_nritems(leaf
)) {
3884 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3887 leaf
= path
->nodes
[0];
3890 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3891 if (key
.objectid
>= last
) {
3896 if (key
.type
!= BTRFS_EXTENT_ITEM_KEY
&&
3897 key
.type
!= BTRFS_METADATA_ITEM_KEY
) {
3902 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
3903 key
.objectid
+ key
.offset
<= rc
->search_start
) {
3908 if (key
.type
== BTRFS_METADATA_ITEM_KEY
&&
3909 key
.objectid
+ fs_info
->nodesize
<=
3915 ret
= find_first_extent_bit(&rc
->processed_blocks
,
3916 key
.objectid
, &start
, &end
,
3917 EXTENT_DIRTY
, NULL
);
3919 if (ret
== 0 && start
<= key
.objectid
) {
3920 btrfs_release_path(path
);
3921 rc
->search_start
= end
+ 1;
3923 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
)
3924 rc
->search_start
= key
.objectid
+ key
.offset
;
3926 rc
->search_start
= key
.objectid
+
3928 memcpy(extent_key
, &key
, sizeof(key
));
3932 btrfs_release_path(path
);
3936 static void set_reloc_control(struct reloc_control
*rc
)
3938 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3940 mutex_lock(&fs_info
->reloc_mutex
);
3941 fs_info
->reloc_ctl
= rc
;
3942 mutex_unlock(&fs_info
->reloc_mutex
);
3945 static void unset_reloc_control(struct reloc_control
*rc
)
3947 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3949 mutex_lock(&fs_info
->reloc_mutex
);
3950 fs_info
->reloc_ctl
= NULL
;
3951 mutex_unlock(&fs_info
->reloc_mutex
);
3954 static int check_extent_flags(u64 flags
)
3956 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3957 (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3959 if (!(flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3960 !(flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3962 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3963 (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
))
3968 static noinline_for_stack
3969 int prepare_to_relocate(struct reloc_control
*rc
)
3971 struct btrfs_trans_handle
*trans
;
3974 rc
->block_rsv
= btrfs_alloc_block_rsv(rc
->extent_root
->fs_info
,
3975 BTRFS_BLOCK_RSV_TEMP
);
3979 memset(&rc
->cluster
, 0, sizeof(rc
->cluster
));
3980 rc
->search_start
= rc
->block_group
->start
;
3981 rc
->extents_found
= 0;
3982 rc
->nodes_relocated
= 0;
3983 rc
->merging_rsv_size
= 0;
3984 rc
->reserved_bytes
= 0;
3985 rc
->block_rsv
->size
= rc
->extent_root
->fs_info
->nodesize
*
3986 RELOCATION_RESERVED_NODES
;
3987 ret
= btrfs_block_rsv_refill(rc
->extent_root
,
3988 rc
->block_rsv
, rc
->block_rsv
->size
,
3989 BTRFS_RESERVE_FLUSH_ALL
);
3993 rc
->create_reloc_tree
= 1;
3994 set_reloc_control(rc
);
3996 trans
= btrfs_join_transaction(rc
->extent_root
);
3997 if (IS_ERR(trans
)) {
3998 unset_reloc_control(rc
);
4000 * extent tree is not a ref_cow tree and has no reloc_root to
4001 * cleanup. And callers are responsible to free the above
4004 return PTR_ERR(trans
);
4006 btrfs_commit_transaction(trans
);
4010 static noinline_for_stack
int relocate_block_group(struct reloc_control
*rc
)
4012 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
4013 struct rb_root blocks
= RB_ROOT
;
4014 struct btrfs_key key
;
4015 struct btrfs_trans_handle
*trans
= NULL
;
4016 struct btrfs_path
*path
;
4017 struct btrfs_extent_item
*ei
;
4024 path
= btrfs_alloc_path();
4027 path
->reada
= READA_FORWARD
;
4029 ret
= prepare_to_relocate(rc
);
4036 rc
->reserved_bytes
= 0;
4037 ret
= btrfs_block_rsv_refill(rc
->extent_root
,
4038 rc
->block_rsv
, rc
->block_rsv
->size
,
4039 BTRFS_RESERVE_FLUSH_ALL
);
4045 trans
= btrfs_start_transaction(rc
->extent_root
, 0);
4046 if (IS_ERR(trans
)) {
4047 err
= PTR_ERR(trans
);
4052 if (update_backref_cache(trans
, &rc
->backref_cache
)) {
4053 btrfs_end_transaction(trans
);
4058 ret
= find_next_extent(rc
, path
, &key
);
4064 rc
->extents_found
++;
4066 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
4067 struct btrfs_extent_item
);
4068 item_size
= btrfs_item_size_nr(path
->nodes
[0], path
->slots
[0]);
4069 if (item_size
>= sizeof(*ei
)) {
4070 flags
= btrfs_extent_flags(path
->nodes
[0], ei
);
4071 ret
= check_extent_flags(flags
);
4073 } else if (unlikely(item_size
== sizeof(struct btrfs_extent_item_v0
))) {
4075 btrfs_print_v0_err(trans
->fs_info
);
4076 btrfs_abort_transaction(trans
, err
);
4082 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
4083 ret
= add_tree_block(rc
, &key
, path
, &blocks
);
4084 } else if (rc
->stage
== UPDATE_DATA_PTRS
&&
4085 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
4086 ret
= add_data_references(rc
, &key
, path
, &blocks
);
4088 btrfs_release_path(path
);
4096 if (!RB_EMPTY_ROOT(&blocks
)) {
4097 ret
= relocate_tree_blocks(trans
, rc
, &blocks
);
4100 * if we fail to relocate tree blocks, force to update
4101 * backref cache when committing transaction.
4103 rc
->backref_cache
.last_trans
= trans
->transid
- 1;
4105 if (ret
!= -EAGAIN
) {
4109 rc
->extents_found
--;
4110 rc
->search_start
= key
.objectid
;
4114 btrfs_end_transaction_throttle(trans
);
4115 btrfs_btree_balance_dirty(fs_info
);
4118 if (rc
->stage
== MOVE_DATA_EXTENTS
&&
4119 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
4120 rc
->found_file_extent
= 1;
4121 ret
= relocate_data_extent(rc
->data_inode
,
4122 &key
, &rc
->cluster
);
4129 if (trans
&& progress
&& err
== -ENOSPC
) {
4130 ret
= btrfs_force_chunk_alloc(trans
, rc
->block_group
->flags
);
4138 btrfs_release_path(path
);
4139 clear_extent_bits(&rc
->processed_blocks
, 0, (u64
)-1, EXTENT_DIRTY
);
4142 btrfs_end_transaction_throttle(trans
);
4143 btrfs_btree_balance_dirty(fs_info
);
4147 ret
= relocate_file_extent_cluster(rc
->data_inode
,
4153 rc
->create_reloc_tree
= 0;
4154 set_reloc_control(rc
);
4156 backref_cache_cleanup(&rc
->backref_cache
);
4157 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
, (u64
)-1);
4159 err
= prepare_to_merge(rc
, err
);
4161 merge_reloc_roots(rc
);
4163 rc
->merge_reloc_tree
= 0;
4164 unset_reloc_control(rc
);
4165 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
, (u64
)-1);
4167 /* get rid of pinned extents */
4168 trans
= btrfs_join_transaction(rc
->extent_root
);
4169 if (IS_ERR(trans
)) {
4170 err
= PTR_ERR(trans
);
4173 btrfs_commit_transaction(trans
);
4174 ret
= clean_dirty_subvols(rc
);
4175 if (ret
< 0 && !err
)
4178 btrfs_free_block_rsv(fs_info
, rc
->block_rsv
);
4179 btrfs_free_path(path
);
4183 static int __insert_orphan_inode(struct btrfs_trans_handle
*trans
,
4184 struct btrfs_root
*root
, u64 objectid
)
4186 struct btrfs_path
*path
;
4187 struct btrfs_inode_item
*item
;
4188 struct extent_buffer
*leaf
;
4191 path
= btrfs_alloc_path();
4195 ret
= btrfs_insert_empty_inode(trans
, root
, path
, objectid
);
4199 leaf
= path
->nodes
[0];
4200 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_inode_item
);
4201 memzero_extent_buffer(leaf
, (unsigned long)item
, sizeof(*item
));
4202 btrfs_set_inode_generation(leaf
, item
, 1);
4203 btrfs_set_inode_size(leaf
, item
, 0);
4204 btrfs_set_inode_mode(leaf
, item
, S_IFREG
| 0600);
4205 btrfs_set_inode_flags(leaf
, item
, BTRFS_INODE_NOCOMPRESS
|
4206 BTRFS_INODE_PREALLOC
);
4207 btrfs_mark_buffer_dirty(leaf
);
4209 btrfs_free_path(path
);
4214 * helper to create inode for data relocation.
4215 * the inode is in data relocation tree and its link count is 0
4217 static noinline_for_stack
4218 struct inode
*create_reloc_inode(struct btrfs_fs_info
*fs_info
,
4219 struct btrfs_block_group
*group
)
4221 struct inode
*inode
= NULL
;
4222 struct btrfs_trans_handle
*trans
;
4223 struct btrfs_root
*root
;
4224 struct btrfs_key key
;
4228 root
= read_fs_root(fs_info
, BTRFS_DATA_RELOC_TREE_OBJECTID
);
4230 return ERR_CAST(root
);
4232 trans
= btrfs_start_transaction(root
, 6);
4234 return ERR_CAST(trans
);
4236 err
= btrfs_find_free_objectid(root
, &objectid
);
4240 err
= __insert_orphan_inode(trans
, root
, objectid
);
4243 key
.objectid
= objectid
;
4244 key
.type
= BTRFS_INODE_ITEM_KEY
;
4246 inode
= btrfs_iget(fs_info
->sb
, &key
, root
);
4247 BUG_ON(IS_ERR(inode
));
4248 BTRFS_I(inode
)->index_cnt
= group
->start
;
4250 err
= btrfs_orphan_add(trans
, BTRFS_I(inode
));
4252 btrfs_end_transaction(trans
);
4253 btrfs_btree_balance_dirty(fs_info
);
4257 inode
= ERR_PTR(err
);
4262 static struct reloc_control
*alloc_reloc_control(struct btrfs_fs_info
*fs_info
)
4264 struct reloc_control
*rc
;
4266 rc
= kzalloc(sizeof(*rc
), GFP_NOFS
);
4270 INIT_LIST_HEAD(&rc
->reloc_roots
);
4271 INIT_LIST_HEAD(&rc
->dirty_subvol_roots
);
4272 backref_cache_init(&rc
->backref_cache
);
4273 mapping_tree_init(&rc
->reloc_root_tree
);
4274 extent_io_tree_init(fs_info
, &rc
->processed_blocks
,
4275 IO_TREE_RELOC_BLOCKS
, NULL
);
4280 * Print the block group being relocated
4282 static void describe_relocation(struct btrfs_fs_info
*fs_info
,
4283 struct btrfs_block_group
*block_group
)
4285 char buf
[128] = {'\0'};
4287 btrfs_describe_block_groups(block_group
->flags
, buf
, sizeof(buf
));
4290 "relocating block group %llu flags %s",
4291 block_group
->start
, buf
);
4295 * function to relocate all extents in a block group.
4297 int btrfs_relocate_block_group(struct btrfs_fs_info
*fs_info
, u64 group_start
)
4299 struct btrfs_block_group
*bg
;
4300 struct btrfs_root
*extent_root
= fs_info
->extent_root
;
4301 struct reloc_control
*rc
;
4302 struct inode
*inode
;
4303 struct btrfs_path
*path
;
4308 bg
= btrfs_lookup_block_group(fs_info
, group_start
);
4312 if (btrfs_pinned_by_swapfile(fs_info
, bg
)) {
4313 btrfs_put_block_group(bg
);
4317 rc
= alloc_reloc_control(fs_info
);
4319 btrfs_put_block_group(bg
);
4323 rc
->extent_root
= extent_root
;
4324 rc
->block_group
= bg
;
4326 ret
= btrfs_inc_block_group_ro(rc
->block_group
, true);
4333 path
= btrfs_alloc_path();
4339 inode
= lookup_free_space_inode(rc
->block_group
, path
);
4340 btrfs_free_path(path
);
4343 ret
= delete_block_group_cache(fs_info
, rc
->block_group
, inode
, 0);
4345 ret
= PTR_ERR(inode
);
4347 if (ret
&& ret
!= -ENOENT
) {
4352 rc
->data_inode
= create_reloc_inode(fs_info
, rc
->block_group
);
4353 if (IS_ERR(rc
->data_inode
)) {
4354 err
= PTR_ERR(rc
->data_inode
);
4355 rc
->data_inode
= NULL
;
4359 describe_relocation(fs_info
, rc
->block_group
);
4361 btrfs_wait_block_group_reservations(rc
->block_group
);
4362 btrfs_wait_nocow_writers(rc
->block_group
);
4363 btrfs_wait_ordered_roots(fs_info
, U64_MAX
,
4364 rc
->block_group
->start
,
4365 rc
->block_group
->length
);
4368 mutex_lock(&fs_info
->cleaner_mutex
);
4369 ret
= relocate_block_group(rc
);
4370 mutex_unlock(&fs_info
->cleaner_mutex
);
4375 * We may have gotten ENOSPC after we already dirtied some
4376 * extents. If writeout happens while we're relocating a
4377 * different block group we could end up hitting the
4378 * BUG_ON(rc->stage == UPDATE_DATA_PTRS) in
4379 * btrfs_reloc_cow_block. Make sure we write everything out
4380 * properly so we don't trip over this problem, and then break
4381 * out of the loop if we hit an error.
4383 if (rc
->stage
== MOVE_DATA_EXTENTS
&& rc
->found_file_extent
) {
4384 ret
= btrfs_wait_ordered_range(rc
->data_inode
, 0,
4388 invalidate_mapping_pages(rc
->data_inode
->i_mapping
,
4390 rc
->stage
= UPDATE_DATA_PTRS
;
4396 if (rc
->extents_found
== 0)
4399 btrfs_info(fs_info
, "found %llu extents", rc
->extents_found
);
4403 WARN_ON(rc
->block_group
->pinned
> 0);
4404 WARN_ON(rc
->block_group
->reserved
> 0);
4405 WARN_ON(rc
->block_group
->used
> 0);
4408 btrfs_dec_block_group_ro(rc
->block_group
);
4409 iput(rc
->data_inode
);
4410 btrfs_put_block_group(rc
->block_group
);
4415 static noinline_for_stack
int mark_garbage_root(struct btrfs_root
*root
)
4417 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
4418 struct btrfs_trans_handle
*trans
;
4421 trans
= btrfs_start_transaction(fs_info
->tree_root
, 0);
4423 return PTR_ERR(trans
);
4425 memset(&root
->root_item
.drop_progress
, 0,
4426 sizeof(root
->root_item
.drop_progress
));
4427 root
->root_item
.drop_level
= 0;
4428 btrfs_set_root_refs(&root
->root_item
, 0);
4429 ret
= btrfs_update_root(trans
, fs_info
->tree_root
,
4430 &root
->root_key
, &root
->root_item
);
4432 err
= btrfs_end_transaction(trans
);
4439 * recover relocation interrupted by system crash.
4441 * this function resumes merging reloc trees with corresponding fs trees.
4442 * this is important for keeping the sharing of tree blocks
4444 int btrfs_recover_relocation(struct btrfs_root
*root
)
4446 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
4447 LIST_HEAD(reloc_roots
);
4448 struct btrfs_key key
;
4449 struct btrfs_root
*fs_root
;
4450 struct btrfs_root
*reloc_root
;
4451 struct btrfs_path
*path
;
4452 struct extent_buffer
*leaf
;
4453 struct reloc_control
*rc
= NULL
;
4454 struct btrfs_trans_handle
*trans
;
4458 path
= btrfs_alloc_path();
4461 path
->reada
= READA_BACK
;
4463 key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
4464 key
.type
= BTRFS_ROOT_ITEM_KEY
;
4465 key
.offset
= (u64
)-1;
4468 ret
= btrfs_search_slot(NULL
, fs_info
->tree_root
, &key
,
4475 if (path
->slots
[0] == 0)
4479 leaf
= path
->nodes
[0];
4480 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
4481 btrfs_release_path(path
);
4483 if (key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
||
4484 key
.type
!= BTRFS_ROOT_ITEM_KEY
)
4487 reloc_root
= btrfs_read_fs_root(root
, &key
);
4488 if (IS_ERR(reloc_root
)) {
4489 err
= PTR_ERR(reloc_root
);
4493 list_add(&reloc_root
->root_list
, &reloc_roots
);
4495 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
4496 fs_root
= read_fs_root(fs_info
,
4497 reloc_root
->root_key
.offset
);
4498 if (IS_ERR(fs_root
)) {
4499 ret
= PTR_ERR(fs_root
);
4500 if (ret
!= -ENOENT
) {
4504 ret
= mark_garbage_root(reloc_root
);
4512 if (key
.offset
== 0)
4517 btrfs_release_path(path
);
4519 if (list_empty(&reloc_roots
))
4522 rc
= alloc_reloc_control(fs_info
);
4528 rc
->extent_root
= fs_info
->extent_root
;
4530 set_reloc_control(rc
);
4532 trans
= btrfs_join_transaction(rc
->extent_root
);
4533 if (IS_ERR(trans
)) {
4534 unset_reloc_control(rc
);
4535 err
= PTR_ERR(trans
);
4539 rc
->merge_reloc_tree
= 1;
4541 while (!list_empty(&reloc_roots
)) {
4542 reloc_root
= list_entry(reloc_roots
.next
,
4543 struct btrfs_root
, root_list
);
4544 list_del(&reloc_root
->root_list
);
4546 if (btrfs_root_refs(&reloc_root
->root_item
) == 0) {
4547 list_add_tail(&reloc_root
->root_list
,
4552 fs_root
= read_fs_root(fs_info
, reloc_root
->root_key
.offset
);
4553 if (IS_ERR(fs_root
)) {
4554 err
= PTR_ERR(fs_root
);
4555 list_add_tail(&reloc_root
->root_list
, &reloc_roots
);
4559 err
= __add_reloc_root(reloc_root
);
4560 BUG_ON(err
< 0); /* -ENOMEM or logic error */
4561 fs_root
->reloc_root
= reloc_root
;
4564 err
= btrfs_commit_transaction(trans
);
4568 merge_reloc_roots(rc
);
4570 unset_reloc_control(rc
);
4572 trans
= btrfs_join_transaction(rc
->extent_root
);
4573 if (IS_ERR(trans
)) {
4574 err
= PTR_ERR(trans
);
4577 err
= btrfs_commit_transaction(trans
);
4579 ret
= clean_dirty_subvols(rc
);
4580 if (ret
< 0 && !err
)
4585 if (!list_empty(&reloc_roots
))
4586 free_reloc_roots(&reloc_roots
);
4588 btrfs_free_path(path
);
4591 /* cleanup orphan inode in data relocation tree */
4592 fs_root
= read_fs_root(fs_info
, BTRFS_DATA_RELOC_TREE_OBJECTID
);
4593 if (IS_ERR(fs_root
))
4594 err
= PTR_ERR(fs_root
);
4596 err
= btrfs_orphan_cleanup(fs_root
);
4602 * helper to add ordered checksum for data relocation.
4604 * cloning checksum properly handles the nodatasum extents.
4605 * it also saves CPU time to re-calculate the checksum.
4607 int btrfs_reloc_clone_csums(struct inode
*inode
, u64 file_pos
, u64 len
)
4609 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
4610 struct btrfs_ordered_sum
*sums
;
4611 struct btrfs_ordered_extent
*ordered
;
4617 ordered
= btrfs_lookup_ordered_extent(inode
, file_pos
);
4618 BUG_ON(ordered
->file_offset
!= file_pos
|| ordered
->len
!= len
);
4620 disk_bytenr
= file_pos
+ BTRFS_I(inode
)->index_cnt
;
4621 ret
= btrfs_lookup_csums_range(fs_info
->csum_root
, disk_bytenr
,
4622 disk_bytenr
+ len
- 1, &list
, 0);
4626 while (!list_empty(&list
)) {
4627 sums
= list_entry(list
.next
, struct btrfs_ordered_sum
, list
);
4628 list_del_init(&sums
->list
);
4631 * We need to offset the new_bytenr based on where the csum is.
4632 * We need to do this because we will read in entire prealloc
4633 * extents but we may have written to say the middle of the
4634 * prealloc extent, so we need to make sure the csum goes with
4635 * the right disk offset.
4637 * We can do this because the data reloc inode refers strictly
4638 * to the on disk bytes, so we don't have to worry about
4639 * disk_len vs real len like with real inodes since it's all
4642 new_bytenr
= ordered
->start
+ (sums
->bytenr
- disk_bytenr
);
4643 sums
->bytenr
= new_bytenr
;
4645 btrfs_add_ordered_sum(ordered
, sums
);
4648 btrfs_put_ordered_extent(ordered
);
4652 int btrfs_reloc_cow_block(struct btrfs_trans_handle
*trans
,
4653 struct btrfs_root
*root
, struct extent_buffer
*buf
,
4654 struct extent_buffer
*cow
)
4656 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
4657 struct reloc_control
*rc
;
4658 struct backref_node
*node
;
4663 rc
= fs_info
->reloc_ctl
;
4667 BUG_ON(rc
->stage
== UPDATE_DATA_PTRS
&&
4668 root
->root_key
.objectid
== BTRFS_DATA_RELOC_TREE_OBJECTID
);
4670 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
4671 if (buf
== root
->node
)
4672 __update_reloc_root(root
, cow
->start
);
4675 level
= btrfs_header_level(buf
);
4676 if (btrfs_header_generation(buf
) <=
4677 btrfs_root_last_snapshot(&root
->root_item
))
4680 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
&&
4681 rc
->create_reloc_tree
) {
4682 WARN_ON(!first_cow
&& level
== 0);
4684 node
= rc
->backref_cache
.path
[level
];
4685 BUG_ON(node
->bytenr
!= buf
->start
&&
4686 node
->new_bytenr
!= buf
->start
);
4688 drop_node_buffer(node
);
4689 atomic_inc(&cow
->refs
);
4691 node
->new_bytenr
= cow
->start
;
4693 if (!node
->pending
) {
4694 list_move_tail(&node
->list
,
4695 &rc
->backref_cache
.pending
[level
]);
4700 __mark_block_processed(rc
, node
);
4702 if (first_cow
&& level
> 0)
4703 rc
->nodes_relocated
+= buf
->len
;
4706 if (level
== 0 && first_cow
&& rc
->stage
== UPDATE_DATA_PTRS
)
4707 ret
= replace_file_extents(trans
, rc
, root
, cow
);
4712 * called before creating snapshot. it calculates metadata reservation
4713 * required for relocating tree blocks in the snapshot
4715 void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot
*pending
,
4716 u64
*bytes_to_reserve
)
4718 struct btrfs_root
*root
= pending
->root
;
4719 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
4721 if (!root
->reloc_root
|| !rc
)
4724 if (!rc
->merge_reloc_tree
)
4727 root
= root
->reloc_root
;
4728 BUG_ON(btrfs_root_refs(&root
->root_item
) == 0);
4730 * relocation is in the stage of merging trees. the space
4731 * used by merging a reloc tree is twice the size of
4732 * relocated tree nodes in the worst case. half for cowing
4733 * the reloc tree, half for cowing the fs tree. the space
4734 * used by cowing the reloc tree will be freed after the
4735 * tree is dropped. if we create snapshot, cowing the fs
4736 * tree may use more space than it frees. so we need
4737 * reserve extra space.
4739 *bytes_to_reserve
+= rc
->nodes_relocated
;
4743 * called after snapshot is created. migrate block reservation
4744 * and create reloc root for the newly created snapshot
4746 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle
*trans
,
4747 struct btrfs_pending_snapshot
*pending
)
4749 struct btrfs_root
*root
= pending
->root
;
4750 struct btrfs_root
*reloc_root
;
4751 struct btrfs_root
*new_root
;
4752 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
4755 if (!root
->reloc_root
|| !rc
)
4758 rc
= root
->fs_info
->reloc_ctl
;
4759 rc
->merging_rsv_size
+= rc
->nodes_relocated
;
4761 if (rc
->merge_reloc_tree
) {
4762 ret
= btrfs_block_rsv_migrate(&pending
->block_rsv
,
4764 rc
->nodes_relocated
, true);
4769 new_root
= pending
->snap
;
4770 reloc_root
= create_reloc_root(trans
, root
->reloc_root
,
4771 new_root
->root_key
.objectid
);
4772 if (IS_ERR(reloc_root
))
4773 return PTR_ERR(reloc_root
);
4775 ret
= __add_reloc_root(reloc_root
);
4777 new_root
->reloc_root
= reloc_root
;
4779 if (rc
->create_reloc_tree
)
4780 ret
= clone_backref_node(trans
, rc
, root
, reloc_root
);