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>
12 #include <linux/error-injection.h>
15 #include "transaction.h"
18 #include "btrfs_inode.h"
19 #include "async-thread.h"
20 #include "free-space-cache.h"
22 #include "print-tree.h"
23 #include "delalloc-space.h"
24 #include "block-group.h"
31 * [What does relocation do]
33 * The objective of relocation is to relocate all extents of the target block
34 * group to other block groups.
35 * This is utilized by resize (shrink only), profile converting, compacting
36 * space, or balance routine to spread chunks over devices.
39 * ------------------------------------------------------------------
40 * BG A: 10 data extents | BG A: deleted
41 * BG B: 2 data extents | BG B: 10 data extents (2 old + 8 relocated)
42 * BG C: 1 extents | BG C: 3 data extents (1 old + 2 relocated)
44 * [How does relocation work]
46 * 1. Mark the target block group read-only
47 * New extents won't be allocated from the target block group.
49 * 2.1 Record each extent in the target block group
50 * To build a proper map of extents to be relocated.
52 * 2.2 Build data reloc tree and reloc trees
53 * Data reloc tree will contain an inode, recording all newly relocated
55 * There will be only one data reloc tree for one data block group.
57 * Reloc tree will be a special snapshot of its source tree, containing
58 * relocated tree blocks.
59 * Each tree referring to a tree block in target block group will get its
62 * 2.3 Swap source tree with its corresponding reloc tree
63 * Each involved tree only refers to new extents after swap.
65 * 3. Cleanup reloc trees and data reloc tree.
66 * As old extents in the target block group are still referenced by reloc
67 * trees, we need to clean them up before really freeing the target block
70 * The main complexity is in steps 2.2 and 2.3.
72 * The entry point of relocation is relocate_block_group() function.
75 #define RELOCATION_RESERVED_NODES 256
77 * map address of tree root to tree
81 struct rb_node rb_node
;
83 }; /* Use rb_simle_node for search/insert */
88 struct rb_root rb_root
;
93 * present a tree block to process
97 struct rb_node rb_node
;
99 }; /* Use rb_simple_node for search/insert */
100 struct btrfs_key key
;
101 unsigned int level
:8;
102 unsigned int key_ready
:1;
105 #define MAX_EXTENTS 128
107 struct file_extent_cluster
{
110 u64 boundary
[MAX_EXTENTS
];
114 struct reloc_control
{
115 /* block group to relocate */
116 struct btrfs_block_group
*block_group
;
118 struct btrfs_root
*extent_root
;
119 /* inode for moving data */
120 struct inode
*data_inode
;
122 struct btrfs_block_rsv
*block_rsv
;
124 struct btrfs_backref_cache backref_cache
;
126 struct file_extent_cluster cluster
;
127 /* tree blocks have been processed */
128 struct extent_io_tree processed_blocks
;
129 /* map start of tree root to corresponding reloc tree */
130 struct mapping_tree reloc_root_tree
;
131 /* list of reloc trees */
132 struct list_head reloc_roots
;
133 /* list of subvolume trees that get relocated */
134 struct list_head dirty_subvol_roots
;
135 /* size of metadata reservation for merging reloc trees */
136 u64 merging_rsv_size
;
137 /* size of relocated tree nodes */
139 /* reserved size for block group relocation*/
145 unsigned int stage
:8;
146 unsigned int create_reloc_tree
:1;
147 unsigned int merge_reloc_tree
:1;
148 unsigned int found_file_extent
:1;
151 /* stages of data relocation */
152 #define MOVE_DATA_EXTENTS 0
153 #define UPDATE_DATA_PTRS 1
155 static void mark_block_processed(struct reloc_control
*rc
,
156 struct btrfs_backref_node
*node
)
160 if (node
->level
== 0 ||
161 in_range(node
->bytenr
, rc
->block_group
->start
,
162 rc
->block_group
->length
)) {
163 blocksize
= rc
->extent_root
->fs_info
->nodesize
;
164 set_extent_bits(&rc
->processed_blocks
, node
->bytenr
,
165 node
->bytenr
+ blocksize
- 1, EXTENT_DIRTY
);
171 static void mapping_tree_init(struct mapping_tree
*tree
)
173 tree
->rb_root
= RB_ROOT
;
174 spin_lock_init(&tree
->lock
);
178 * walk up backref nodes until reach node presents tree root
180 static struct btrfs_backref_node
*walk_up_backref(
181 struct btrfs_backref_node
*node
,
182 struct btrfs_backref_edge
*edges
[], int *index
)
184 struct btrfs_backref_edge
*edge
;
187 while (!list_empty(&node
->upper
)) {
188 edge
= list_entry(node
->upper
.next
,
189 struct btrfs_backref_edge
, list
[LOWER
]);
191 node
= edge
->node
[UPPER
];
193 BUG_ON(node
->detached
);
199 * walk down backref nodes to find start of next reference path
201 static struct btrfs_backref_node
*walk_down_backref(
202 struct btrfs_backref_edge
*edges
[], int *index
)
204 struct btrfs_backref_edge
*edge
;
205 struct btrfs_backref_node
*lower
;
209 edge
= edges
[idx
- 1];
210 lower
= edge
->node
[LOWER
];
211 if (list_is_last(&edge
->list
[LOWER
], &lower
->upper
)) {
215 edge
= list_entry(edge
->list
[LOWER
].next
,
216 struct btrfs_backref_edge
, list
[LOWER
]);
217 edges
[idx
- 1] = edge
;
219 return edge
->node
[UPPER
];
225 static void update_backref_node(struct btrfs_backref_cache
*cache
,
226 struct btrfs_backref_node
*node
, u64 bytenr
)
228 struct rb_node
*rb_node
;
229 rb_erase(&node
->rb_node
, &cache
->rb_root
);
230 node
->bytenr
= bytenr
;
231 rb_node
= rb_simple_insert(&cache
->rb_root
, node
->bytenr
, &node
->rb_node
);
233 btrfs_backref_panic(cache
->fs_info
, bytenr
, -EEXIST
);
237 * update backref cache after a transaction commit
239 static int update_backref_cache(struct btrfs_trans_handle
*trans
,
240 struct btrfs_backref_cache
*cache
)
242 struct btrfs_backref_node
*node
;
245 if (cache
->last_trans
== 0) {
246 cache
->last_trans
= trans
->transid
;
250 if (cache
->last_trans
== trans
->transid
)
254 * detached nodes are used to avoid unnecessary backref
255 * lookup. transaction commit changes the extent tree.
256 * so the detached nodes are no longer useful.
258 while (!list_empty(&cache
->detached
)) {
259 node
= list_entry(cache
->detached
.next
,
260 struct btrfs_backref_node
, list
);
261 btrfs_backref_cleanup_node(cache
, node
);
264 while (!list_empty(&cache
->changed
)) {
265 node
= list_entry(cache
->changed
.next
,
266 struct btrfs_backref_node
, list
);
267 list_del_init(&node
->list
);
268 BUG_ON(node
->pending
);
269 update_backref_node(cache
, node
, node
->new_bytenr
);
273 * some nodes can be left in the pending list if there were
274 * errors during processing the pending nodes.
276 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
277 list_for_each_entry(node
, &cache
->pending
[level
], list
) {
278 BUG_ON(!node
->pending
);
279 if (node
->bytenr
== node
->new_bytenr
)
281 update_backref_node(cache
, node
, node
->new_bytenr
);
285 cache
->last_trans
= 0;
289 static bool reloc_root_is_dead(struct btrfs_root
*root
)
292 * Pair with set_bit/clear_bit in clean_dirty_subvols and
293 * btrfs_update_reloc_root. We need to see the updated bit before
294 * trying to access reloc_root
297 if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE
, &root
->state
))
303 * Check if this subvolume tree has valid reloc tree.
305 * Reloc tree after swap is considered dead, thus not considered as valid.
306 * This is enough for most callers, as they don't distinguish dead reloc root
307 * from no reloc root. But btrfs_should_ignore_reloc_root() below is a
310 static bool have_reloc_root(struct btrfs_root
*root
)
312 if (reloc_root_is_dead(root
))
314 if (!root
->reloc_root
)
319 int btrfs_should_ignore_reloc_root(struct btrfs_root
*root
)
321 struct btrfs_root
*reloc_root
;
323 if (!test_bit(BTRFS_ROOT_SHAREABLE
, &root
->state
))
326 /* This root has been merged with its reloc tree, we can ignore it */
327 if (reloc_root_is_dead(root
))
330 reloc_root
= root
->reloc_root
;
334 if (btrfs_header_generation(reloc_root
->commit_root
) ==
335 root
->fs_info
->running_transaction
->transid
)
338 * if there is reloc tree and it was created in previous
339 * transaction backref lookup can find the reloc tree,
340 * so backref node for the fs tree root is useless for
347 * find reloc tree by address of tree root
349 struct btrfs_root
*find_reloc_root(struct btrfs_fs_info
*fs_info
, u64 bytenr
)
351 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
352 struct rb_node
*rb_node
;
353 struct mapping_node
*node
;
354 struct btrfs_root
*root
= NULL
;
357 spin_lock(&rc
->reloc_root_tree
.lock
);
358 rb_node
= rb_simple_search(&rc
->reloc_root_tree
.rb_root
, bytenr
);
360 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
361 root
= (struct btrfs_root
*)node
->data
;
363 spin_unlock(&rc
->reloc_root_tree
.lock
);
364 return btrfs_grab_root(root
);
368 * For useless nodes, do two major clean ups:
370 * - Cleanup the children edges and nodes
371 * If child node is also orphan (no parent) during cleanup, then the child
372 * node will also be cleaned up.
374 * - Freeing up leaves (level 0), keeps nodes detached
375 * For nodes, the node is still cached as "detached"
377 * Return false if @node is not in the @useless_nodes list.
378 * Return true if @node is in the @useless_nodes list.
380 static bool handle_useless_nodes(struct reloc_control
*rc
,
381 struct btrfs_backref_node
*node
)
383 struct btrfs_backref_cache
*cache
= &rc
->backref_cache
;
384 struct list_head
*useless_node
= &cache
->useless_node
;
387 while (!list_empty(useless_node
)) {
388 struct btrfs_backref_node
*cur
;
390 cur
= list_first_entry(useless_node
, struct btrfs_backref_node
,
392 list_del_init(&cur
->list
);
394 /* Only tree root nodes can be added to @useless_nodes */
395 ASSERT(list_empty(&cur
->upper
));
400 /* The node is the lowest node */
402 list_del_init(&cur
->lower
);
406 /* Cleanup the lower edges */
407 while (!list_empty(&cur
->lower
)) {
408 struct btrfs_backref_edge
*edge
;
409 struct btrfs_backref_node
*lower
;
411 edge
= list_entry(cur
->lower
.next
,
412 struct btrfs_backref_edge
, list
[UPPER
]);
413 list_del(&edge
->list
[UPPER
]);
414 list_del(&edge
->list
[LOWER
]);
415 lower
= edge
->node
[LOWER
];
416 btrfs_backref_free_edge(cache
, edge
);
418 /* Child node is also orphan, queue for cleanup */
419 if (list_empty(&lower
->upper
))
420 list_add(&lower
->list
, useless_node
);
422 /* Mark this block processed for relocation */
423 mark_block_processed(rc
, cur
);
426 * Backref nodes for tree leaves are deleted from the cache.
427 * Backref nodes for upper level tree blocks are left in the
428 * cache to avoid unnecessary backref lookup.
430 if (cur
->level
> 0) {
431 list_add(&cur
->list
, &cache
->detached
);
434 rb_erase(&cur
->rb_node
, &cache
->rb_root
);
435 btrfs_backref_free_node(cache
, cur
);
442 * Build backref tree for a given tree block. Root of the backref tree
443 * corresponds the tree block, leaves of the backref tree correspond roots of
444 * b-trees that reference the tree block.
446 * The basic idea of this function is check backrefs of a given block to find
447 * upper level blocks that reference the block, and then check backrefs of
448 * these upper level blocks recursively. The recursion stops when tree root is
449 * reached or backrefs for the block is cached.
451 * NOTE: if we find that backrefs for a block are cached, we know backrefs for
452 * all upper level blocks that directly/indirectly reference the block are also
455 static noinline_for_stack
struct btrfs_backref_node
*build_backref_tree(
456 struct reloc_control
*rc
, struct btrfs_key
*node_key
,
457 int level
, u64 bytenr
)
459 struct btrfs_backref_iter
*iter
;
460 struct btrfs_backref_cache
*cache
= &rc
->backref_cache
;
461 /* For searching parent of TREE_BLOCK_REF */
462 struct btrfs_path
*path
;
463 struct btrfs_backref_node
*cur
;
464 struct btrfs_backref_node
*node
= NULL
;
465 struct btrfs_backref_edge
*edge
;
469 iter
= btrfs_backref_iter_alloc(rc
->extent_root
->fs_info
, GFP_NOFS
);
471 return ERR_PTR(-ENOMEM
);
472 path
= btrfs_alloc_path();
478 node
= btrfs_backref_alloc_node(cache
, bytenr
, level
);
487 /* Breadth-first search to build backref cache */
489 ret
= btrfs_backref_add_tree_node(cache
, path
, iter
, node_key
,
495 edge
= list_first_entry_or_null(&cache
->pending_edge
,
496 struct btrfs_backref_edge
, list
[UPPER
]);
498 * The pending list isn't empty, take the first block to
502 list_del_init(&edge
->list
[UPPER
]);
503 cur
= edge
->node
[UPPER
];
507 /* Finish the upper linkage of newly added edges/nodes */
508 ret
= btrfs_backref_finish_upper_links(cache
, node
);
514 if (handle_useless_nodes(rc
, node
))
517 btrfs_backref_iter_free(iter
);
518 btrfs_free_path(path
);
520 btrfs_backref_error_cleanup(cache
, node
);
523 ASSERT(!node
|| !node
->detached
);
524 ASSERT(list_empty(&cache
->useless_node
) &&
525 list_empty(&cache
->pending_edge
));
530 * helper to add backref node for the newly created snapshot.
531 * the backref node is created by cloning backref node that
532 * corresponds to root of source tree
534 static int clone_backref_node(struct btrfs_trans_handle
*trans
,
535 struct reloc_control
*rc
,
536 struct btrfs_root
*src
,
537 struct btrfs_root
*dest
)
539 struct btrfs_root
*reloc_root
= src
->reloc_root
;
540 struct btrfs_backref_cache
*cache
= &rc
->backref_cache
;
541 struct btrfs_backref_node
*node
= NULL
;
542 struct btrfs_backref_node
*new_node
;
543 struct btrfs_backref_edge
*edge
;
544 struct btrfs_backref_edge
*new_edge
;
545 struct rb_node
*rb_node
;
547 if (cache
->last_trans
> 0)
548 update_backref_cache(trans
, cache
);
550 rb_node
= rb_simple_search(&cache
->rb_root
, src
->commit_root
->start
);
552 node
= rb_entry(rb_node
, struct btrfs_backref_node
, rb_node
);
556 BUG_ON(node
->new_bytenr
!= reloc_root
->node
->start
);
560 rb_node
= rb_simple_search(&cache
->rb_root
,
561 reloc_root
->commit_root
->start
);
563 node
= rb_entry(rb_node
, struct btrfs_backref_node
,
565 BUG_ON(node
->detached
);
572 new_node
= btrfs_backref_alloc_node(cache
, dest
->node
->start
,
577 new_node
->lowest
= node
->lowest
;
578 new_node
->checked
= 1;
579 new_node
->root
= btrfs_grab_root(dest
);
580 ASSERT(new_node
->root
);
583 list_for_each_entry(edge
, &node
->lower
, list
[UPPER
]) {
584 new_edge
= btrfs_backref_alloc_edge(cache
);
588 btrfs_backref_link_edge(new_edge
, edge
->node
[LOWER
],
589 new_node
, LINK_UPPER
);
592 list_add_tail(&new_node
->lower
, &cache
->leaves
);
595 rb_node
= rb_simple_insert(&cache
->rb_root
, new_node
->bytenr
,
598 btrfs_backref_panic(trans
->fs_info
, new_node
->bytenr
, -EEXIST
);
600 if (!new_node
->lowest
) {
601 list_for_each_entry(new_edge
, &new_node
->lower
, list
[UPPER
]) {
602 list_add_tail(&new_edge
->list
[LOWER
],
603 &new_edge
->node
[LOWER
]->upper
);
608 while (!list_empty(&new_node
->lower
)) {
609 new_edge
= list_entry(new_node
->lower
.next
,
610 struct btrfs_backref_edge
, list
[UPPER
]);
611 list_del(&new_edge
->list
[UPPER
]);
612 btrfs_backref_free_edge(cache
, new_edge
);
614 btrfs_backref_free_node(cache
, new_node
);
619 * helper to add 'address of tree root -> reloc tree' mapping
621 static int __must_check
__add_reloc_root(struct btrfs_root
*root
)
623 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
624 struct rb_node
*rb_node
;
625 struct mapping_node
*node
;
626 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
628 node
= kmalloc(sizeof(*node
), GFP_NOFS
);
632 node
->bytenr
= root
->commit_root
->start
;
635 spin_lock(&rc
->reloc_root_tree
.lock
);
636 rb_node
= rb_simple_insert(&rc
->reloc_root_tree
.rb_root
,
637 node
->bytenr
, &node
->rb_node
);
638 spin_unlock(&rc
->reloc_root_tree
.lock
);
640 btrfs_panic(fs_info
, -EEXIST
,
641 "Duplicate root found for start=%llu while inserting into relocation tree",
645 list_add_tail(&root
->root_list
, &rc
->reloc_roots
);
650 * helper to delete the 'address of tree root -> reloc tree'
653 static void __del_reloc_root(struct btrfs_root
*root
)
655 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
656 struct rb_node
*rb_node
;
657 struct mapping_node
*node
= NULL
;
658 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
659 bool put_ref
= false;
661 if (rc
&& root
->node
) {
662 spin_lock(&rc
->reloc_root_tree
.lock
);
663 rb_node
= rb_simple_search(&rc
->reloc_root_tree
.rb_root
,
664 root
->commit_root
->start
);
666 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
667 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
668 RB_CLEAR_NODE(&node
->rb_node
);
670 spin_unlock(&rc
->reloc_root_tree
.lock
);
671 ASSERT(!node
|| (struct btrfs_root
*)node
->data
== root
);
675 * We only put the reloc root here if it's on the list. There's a lot
676 * of places where the pattern is to splice the rc->reloc_roots, process
677 * the reloc roots, and then add the reloc root back onto
678 * rc->reloc_roots. If we call __del_reloc_root while it's off of the
679 * list we don't want the reference being dropped, because the guy
680 * messing with the list is in charge of the reference.
682 spin_lock(&fs_info
->trans_lock
);
683 if (!list_empty(&root
->root_list
)) {
685 list_del_init(&root
->root_list
);
687 spin_unlock(&fs_info
->trans_lock
);
689 btrfs_put_root(root
);
694 * helper to update the 'address of tree root -> reloc tree'
697 static int __update_reloc_root(struct btrfs_root
*root
)
699 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
700 struct rb_node
*rb_node
;
701 struct mapping_node
*node
= NULL
;
702 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
704 spin_lock(&rc
->reloc_root_tree
.lock
);
705 rb_node
= rb_simple_search(&rc
->reloc_root_tree
.rb_root
,
706 root
->commit_root
->start
);
708 node
= rb_entry(rb_node
, struct mapping_node
, rb_node
);
709 rb_erase(&node
->rb_node
, &rc
->reloc_root_tree
.rb_root
);
711 spin_unlock(&rc
->reloc_root_tree
.lock
);
715 BUG_ON((struct btrfs_root
*)node
->data
!= root
);
717 spin_lock(&rc
->reloc_root_tree
.lock
);
718 node
->bytenr
= root
->node
->start
;
719 rb_node
= rb_simple_insert(&rc
->reloc_root_tree
.rb_root
,
720 node
->bytenr
, &node
->rb_node
);
721 spin_unlock(&rc
->reloc_root_tree
.lock
);
723 btrfs_backref_panic(fs_info
, node
->bytenr
, -EEXIST
);
727 static struct btrfs_root
*create_reloc_root(struct btrfs_trans_handle
*trans
,
728 struct btrfs_root
*root
, u64 objectid
)
730 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
731 struct btrfs_root
*reloc_root
;
732 struct extent_buffer
*eb
;
733 struct btrfs_root_item
*root_item
;
734 struct btrfs_key root_key
;
736 bool must_abort
= false;
738 root_item
= kmalloc(sizeof(*root_item
), GFP_NOFS
);
740 return ERR_PTR(-ENOMEM
);
742 root_key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
743 root_key
.type
= BTRFS_ROOT_ITEM_KEY
;
744 root_key
.offset
= objectid
;
746 if (root
->root_key
.objectid
== objectid
) {
749 /* called by btrfs_init_reloc_root */
750 ret
= btrfs_copy_root(trans
, root
, root
->commit_root
, &eb
,
751 BTRFS_TREE_RELOC_OBJECTID
);
756 * Set the last_snapshot field to the generation of the commit
757 * root - like this ctree.c:btrfs_block_can_be_shared() behaves
758 * correctly (returns true) when the relocation root is created
759 * either inside the critical section of a transaction commit
760 * (through transaction.c:qgroup_account_snapshot()) and when
761 * it's created before the transaction commit is started.
763 commit_root_gen
= btrfs_header_generation(root
->commit_root
);
764 btrfs_set_root_last_snapshot(&root
->root_item
, commit_root_gen
);
767 * called by btrfs_reloc_post_snapshot_hook.
768 * the source tree is a reloc tree, all tree blocks
769 * modified after it was created have RELOC flag
770 * set in their headers. so it's OK to not update
771 * the 'last_snapshot'.
773 ret
= btrfs_copy_root(trans
, root
, root
->node
, &eb
,
774 BTRFS_TREE_RELOC_OBJECTID
);
780 * We have changed references at this point, we must abort the
781 * transaction if anything fails.
785 memcpy(root_item
, &root
->root_item
, sizeof(*root_item
));
786 btrfs_set_root_bytenr(root_item
, eb
->start
);
787 btrfs_set_root_level(root_item
, btrfs_header_level(eb
));
788 btrfs_set_root_generation(root_item
, trans
->transid
);
790 if (root
->root_key
.objectid
== objectid
) {
791 btrfs_set_root_refs(root_item
, 0);
792 memset(&root_item
->drop_progress
, 0,
793 sizeof(struct btrfs_disk_key
));
794 btrfs_set_root_drop_level(root_item
, 0);
797 btrfs_tree_unlock(eb
);
798 free_extent_buffer(eb
);
800 ret
= btrfs_insert_root(trans
, fs_info
->tree_root
,
801 &root_key
, root_item
);
807 reloc_root
= btrfs_read_tree_root(fs_info
->tree_root
, &root_key
);
808 if (IS_ERR(reloc_root
)) {
809 ret
= PTR_ERR(reloc_root
);
812 set_bit(BTRFS_ROOT_SHAREABLE
, &reloc_root
->state
);
813 reloc_root
->last_trans
= trans
->transid
;
819 btrfs_abort_transaction(trans
, ret
);
824 * create reloc tree for a given fs tree. reloc tree is just a
825 * snapshot of the fs tree with special root objectid.
827 * The reloc_root comes out of here with two references, one for
828 * root->reloc_root, and another for being on the rc->reloc_roots list.
830 int btrfs_init_reloc_root(struct btrfs_trans_handle
*trans
,
831 struct btrfs_root
*root
)
833 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
834 struct btrfs_root
*reloc_root
;
835 struct reloc_control
*rc
= fs_info
->reloc_ctl
;
836 struct btrfs_block_rsv
*rsv
;
844 * The subvolume has reloc tree but the swap is finished, no need to
845 * create/update the dead reloc tree
847 if (reloc_root_is_dead(root
))
851 * This is subtle but important. We do not do
852 * record_root_in_transaction for reloc roots, instead we record their
853 * corresponding fs root, and then here we update the last trans for the
854 * reloc root. This means that we have to do this for the entire life
855 * of the reloc root, regardless of which stage of the relocation we are
858 if (root
->reloc_root
) {
859 reloc_root
= root
->reloc_root
;
860 reloc_root
->last_trans
= trans
->transid
;
865 * We are merging reloc roots, we do not need new reloc trees. Also
866 * reloc trees never need their own reloc tree.
868 if (!rc
->create_reloc_tree
||
869 root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
872 if (!trans
->reloc_reserved
) {
873 rsv
= trans
->block_rsv
;
874 trans
->block_rsv
= rc
->block_rsv
;
877 reloc_root
= create_reloc_root(trans
, root
, root
->root_key
.objectid
);
879 trans
->block_rsv
= rsv
;
881 ret
= __add_reloc_root(reloc_root
);
883 root
->reloc_root
= btrfs_grab_root(reloc_root
);
888 * update root item of reloc tree
890 int btrfs_update_reloc_root(struct btrfs_trans_handle
*trans
,
891 struct btrfs_root
*root
)
893 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
894 struct btrfs_root
*reloc_root
;
895 struct btrfs_root_item
*root_item
;
898 if (!have_reloc_root(root
))
901 reloc_root
= root
->reloc_root
;
902 root_item
= &reloc_root
->root_item
;
905 * We are probably ok here, but __del_reloc_root() will drop its ref of
906 * the root. We have the ref for root->reloc_root, but just in case
907 * hold it while we update the reloc root.
909 btrfs_grab_root(reloc_root
);
911 /* root->reloc_root will stay until current relocation finished */
912 if (fs_info
->reloc_ctl
->merge_reloc_tree
&&
913 btrfs_root_refs(root_item
) == 0) {
914 set_bit(BTRFS_ROOT_DEAD_RELOC_TREE
, &root
->state
);
916 * Mark the tree as dead before we change reloc_root so
917 * have_reloc_root will not touch it from now on.
920 __del_reloc_root(reloc_root
);
923 if (reloc_root
->commit_root
!= reloc_root
->node
) {
924 __update_reloc_root(reloc_root
);
925 btrfs_set_root_node(root_item
, reloc_root
->node
);
926 free_extent_buffer(reloc_root
->commit_root
);
927 reloc_root
->commit_root
= btrfs_root_node(reloc_root
);
930 ret
= btrfs_update_root(trans
, fs_info
->tree_root
,
931 &reloc_root
->root_key
, root_item
);
932 btrfs_put_root(reloc_root
);
937 * helper to find first cached inode with inode number >= objectid
940 static struct inode
*find_next_inode(struct btrfs_root
*root
, u64 objectid
)
942 struct rb_node
*node
;
943 struct rb_node
*prev
;
944 struct btrfs_inode
*entry
;
947 spin_lock(&root
->inode_lock
);
949 node
= root
->inode_tree
.rb_node
;
953 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
955 if (objectid
< btrfs_ino(entry
))
956 node
= node
->rb_left
;
957 else if (objectid
> btrfs_ino(entry
))
958 node
= node
->rb_right
;
964 entry
= rb_entry(prev
, struct btrfs_inode
, rb_node
);
965 if (objectid
<= btrfs_ino(entry
)) {
969 prev
= rb_next(prev
);
973 entry
= rb_entry(node
, struct btrfs_inode
, rb_node
);
974 inode
= igrab(&entry
->vfs_inode
);
976 spin_unlock(&root
->inode_lock
);
980 objectid
= btrfs_ino(entry
) + 1;
981 if (cond_resched_lock(&root
->inode_lock
))
984 node
= rb_next(node
);
986 spin_unlock(&root
->inode_lock
);
991 * get new location of data
993 static int get_new_location(struct inode
*reloc_inode
, u64
*new_bytenr
,
994 u64 bytenr
, u64 num_bytes
)
996 struct btrfs_root
*root
= BTRFS_I(reloc_inode
)->root
;
997 struct btrfs_path
*path
;
998 struct btrfs_file_extent_item
*fi
;
999 struct extent_buffer
*leaf
;
1002 path
= btrfs_alloc_path();
1006 bytenr
-= BTRFS_I(reloc_inode
)->index_cnt
;
1007 ret
= btrfs_lookup_file_extent(NULL
, root
, path
,
1008 btrfs_ino(BTRFS_I(reloc_inode
)), bytenr
, 0);
1016 leaf
= path
->nodes
[0];
1017 fi
= btrfs_item_ptr(leaf
, path
->slots
[0],
1018 struct btrfs_file_extent_item
);
1020 BUG_ON(btrfs_file_extent_offset(leaf
, fi
) ||
1021 btrfs_file_extent_compression(leaf
, fi
) ||
1022 btrfs_file_extent_encryption(leaf
, fi
) ||
1023 btrfs_file_extent_other_encoding(leaf
, fi
));
1025 if (num_bytes
!= btrfs_file_extent_disk_num_bytes(leaf
, fi
)) {
1030 *new_bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1033 btrfs_free_path(path
);
1038 * update file extent items in the tree leaf to point to
1039 * the new locations.
1041 static noinline_for_stack
1042 int replace_file_extents(struct btrfs_trans_handle
*trans
,
1043 struct reloc_control
*rc
,
1044 struct btrfs_root
*root
,
1045 struct extent_buffer
*leaf
)
1047 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1048 struct btrfs_key key
;
1049 struct btrfs_file_extent_item
*fi
;
1050 struct inode
*inode
= NULL
;
1062 if (rc
->stage
!= UPDATE_DATA_PTRS
)
1065 /* reloc trees always use full backref */
1066 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
)
1067 parent
= leaf
->start
;
1071 nritems
= btrfs_header_nritems(leaf
);
1072 for (i
= 0; i
< nritems
; i
++) {
1073 struct btrfs_ref ref
= { 0 };
1076 btrfs_item_key_to_cpu(leaf
, &key
, i
);
1077 if (key
.type
!= BTRFS_EXTENT_DATA_KEY
)
1079 fi
= btrfs_item_ptr(leaf
, i
, struct btrfs_file_extent_item
);
1080 if (btrfs_file_extent_type(leaf
, fi
) ==
1081 BTRFS_FILE_EXTENT_INLINE
)
1083 bytenr
= btrfs_file_extent_disk_bytenr(leaf
, fi
);
1084 num_bytes
= btrfs_file_extent_disk_num_bytes(leaf
, fi
);
1087 if (!in_range(bytenr
, rc
->block_group
->start
,
1088 rc
->block_group
->length
))
1092 * if we are modifying block in fs tree, wait for readpage
1093 * to complete and drop the extent cache
1095 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
) {
1097 inode
= find_next_inode(root
, key
.objectid
);
1099 } else if (inode
&& btrfs_ino(BTRFS_I(inode
)) < key
.objectid
) {
1100 btrfs_add_delayed_iput(inode
);
1101 inode
= find_next_inode(root
, key
.objectid
);
1103 if (inode
&& btrfs_ino(BTRFS_I(inode
)) == key
.objectid
) {
1105 btrfs_file_extent_num_bytes(leaf
, fi
);
1106 WARN_ON(!IS_ALIGNED(key
.offset
,
1107 fs_info
->sectorsize
));
1108 WARN_ON(!IS_ALIGNED(end
, fs_info
->sectorsize
));
1110 ret
= try_lock_extent(&BTRFS_I(inode
)->io_tree
,
1115 btrfs_drop_extent_cache(BTRFS_I(inode
),
1116 key
.offset
, end
, 1);
1117 unlock_extent(&BTRFS_I(inode
)->io_tree
,
1122 ret
= get_new_location(rc
->data_inode
, &new_bytenr
,
1126 * Don't have to abort since we've not changed anything
1127 * in the file extent yet.
1132 btrfs_set_file_extent_disk_bytenr(leaf
, fi
, new_bytenr
);
1135 key
.offset
-= btrfs_file_extent_offset(leaf
, fi
);
1136 btrfs_init_generic_ref(&ref
, BTRFS_ADD_DELAYED_REF
, new_bytenr
,
1138 ref
.real_root
= root
->root_key
.objectid
;
1139 btrfs_init_data_ref(&ref
, btrfs_header_owner(leaf
),
1140 key
.objectid
, key
.offset
);
1141 ret
= btrfs_inc_extent_ref(trans
, &ref
);
1143 btrfs_abort_transaction(trans
, ret
);
1147 btrfs_init_generic_ref(&ref
, BTRFS_DROP_DELAYED_REF
, bytenr
,
1149 ref
.real_root
= root
->root_key
.objectid
;
1150 btrfs_init_data_ref(&ref
, btrfs_header_owner(leaf
),
1151 key
.objectid
, key
.offset
);
1152 ret
= btrfs_free_extent(trans
, &ref
);
1154 btrfs_abort_transaction(trans
, ret
);
1159 btrfs_mark_buffer_dirty(leaf
);
1161 btrfs_add_delayed_iput(inode
);
1165 static noinline_for_stack
1166 int memcmp_node_keys(struct extent_buffer
*eb
, int slot
,
1167 struct btrfs_path
*path
, int level
)
1169 struct btrfs_disk_key key1
;
1170 struct btrfs_disk_key key2
;
1171 btrfs_node_key(eb
, &key1
, slot
);
1172 btrfs_node_key(path
->nodes
[level
], &key2
, path
->slots
[level
]);
1173 return memcmp(&key1
, &key2
, sizeof(key1
));
1177 * try to replace tree blocks in fs tree with the new blocks
1178 * in reloc tree. tree blocks haven't been modified since the
1179 * reloc tree was create can be replaced.
1181 * if a block was replaced, level of the block + 1 is returned.
1182 * if no block got replaced, 0 is returned. if there are other
1183 * errors, a negative error number is returned.
1185 static noinline_for_stack
1186 int replace_path(struct btrfs_trans_handle
*trans
, struct reloc_control
*rc
,
1187 struct btrfs_root
*dest
, struct btrfs_root
*src
,
1188 struct btrfs_path
*path
, struct btrfs_key
*next_key
,
1189 int lowest_level
, int max_level
)
1191 struct btrfs_fs_info
*fs_info
= dest
->fs_info
;
1192 struct extent_buffer
*eb
;
1193 struct extent_buffer
*parent
;
1194 struct btrfs_ref ref
= { 0 };
1195 struct btrfs_key key
;
1207 ASSERT(src
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
);
1208 ASSERT(dest
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
);
1210 last_snapshot
= btrfs_root_last_snapshot(&src
->root_item
);
1212 slot
= path
->slots
[lowest_level
];
1213 btrfs_node_key_to_cpu(path
->nodes
[lowest_level
], &key
, slot
);
1215 eb
= btrfs_lock_root_node(dest
);
1216 level
= btrfs_header_level(eb
);
1218 if (level
< lowest_level
) {
1219 btrfs_tree_unlock(eb
);
1220 free_extent_buffer(eb
);
1225 ret
= btrfs_cow_block(trans
, dest
, eb
, NULL
, 0, &eb
,
1231 next_key
->objectid
= (u64
)-1;
1232 next_key
->type
= (u8
)-1;
1233 next_key
->offset
= (u64
)-1;
1238 level
= btrfs_header_level(parent
);
1239 ASSERT(level
>= lowest_level
);
1241 ret
= btrfs_bin_search(parent
, &key
, &slot
);
1244 if (ret
&& slot
> 0)
1247 if (next_key
&& slot
+ 1 < btrfs_header_nritems(parent
))
1248 btrfs_node_key_to_cpu(parent
, next_key
, slot
+ 1);
1250 old_bytenr
= btrfs_node_blockptr(parent
, slot
);
1251 blocksize
= fs_info
->nodesize
;
1252 old_ptr_gen
= btrfs_node_ptr_generation(parent
, slot
);
1254 if (level
<= max_level
) {
1255 eb
= path
->nodes
[level
];
1256 new_bytenr
= btrfs_node_blockptr(eb
,
1257 path
->slots
[level
]);
1258 new_ptr_gen
= btrfs_node_ptr_generation(eb
,
1259 path
->slots
[level
]);
1265 if (WARN_ON(new_bytenr
> 0 && new_bytenr
== old_bytenr
)) {
1270 if (new_bytenr
== 0 || old_ptr_gen
> last_snapshot
||
1271 memcmp_node_keys(parent
, slot
, path
, level
)) {
1272 if (level
<= lowest_level
) {
1277 eb
= btrfs_read_node_slot(parent
, slot
);
1282 btrfs_tree_lock(eb
);
1284 ret
= btrfs_cow_block(trans
, dest
, eb
, parent
,
1290 btrfs_tree_unlock(parent
);
1291 free_extent_buffer(parent
);
1298 btrfs_tree_unlock(parent
);
1299 free_extent_buffer(parent
);
1304 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
1305 path
->slots
[level
]);
1306 btrfs_release_path(path
);
1308 path
->lowest_level
= level
;
1309 ret
= btrfs_search_slot(trans
, src
, &key
, path
, 0, 1);
1310 path
->lowest_level
= 0;
1314 * Info qgroup to trace both subtrees.
1316 * We must trace both trees.
1317 * 1) Tree reloc subtree
1318 * If not traced, we will leak data numbers
1320 * If not traced, we will double count old data
1322 * We don't scan the subtree right now, but only record
1323 * the swapped tree blocks.
1324 * The real subtree rescan is delayed until we have new
1325 * CoW on the subtree root node before transaction commit.
1327 ret
= btrfs_qgroup_add_swapped_blocks(trans
, dest
,
1328 rc
->block_group
, parent
, slot
,
1329 path
->nodes
[level
], path
->slots
[level
],
1334 * swap blocks in fs tree and reloc tree.
1336 btrfs_set_node_blockptr(parent
, slot
, new_bytenr
);
1337 btrfs_set_node_ptr_generation(parent
, slot
, new_ptr_gen
);
1338 btrfs_mark_buffer_dirty(parent
);
1340 btrfs_set_node_blockptr(path
->nodes
[level
],
1341 path
->slots
[level
], old_bytenr
);
1342 btrfs_set_node_ptr_generation(path
->nodes
[level
],
1343 path
->slots
[level
], old_ptr_gen
);
1344 btrfs_mark_buffer_dirty(path
->nodes
[level
]);
1346 btrfs_init_generic_ref(&ref
, BTRFS_ADD_DELAYED_REF
, old_bytenr
,
1347 blocksize
, path
->nodes
[level
]->start
);
1348 ref
.skip_qgroup
= true;
1349 btrfs_init_tree_ref(&ref
, level
- 1, src
->root_key
.objectid
);
1350 ret
= btrfs_inc_extent_ref(trans
, &ref
);
1352 btrfs_init_generic_ref(&ref
, BTRFS_ADD_DELAYED_REF
, new_bytenr
,
1354 ref
.skip_qgroup
= true;
1355 btrfs_init_tree_ref(&ref
, level
- 1, dest
->root_key
.objectid
);
1356 ret
= btrfs_inc_extent_ref(trans
, &ref
);
1359 btrfs_init_generic_ref(&ref
, BTRFS_DROP_DELAYED_REF
, new_bytenr
,
1360 blocksize
, path
->nodes
[level
]->start
);
1361 btrfs_init_tree_ref(&ref
, level
- 1, src
->root_key
.objectid
);
1362 ref
.skip_qgroup
= true;
1363 ret
= btrfs_free_extent(trans
, &ref
);
1366 btrfs_init_generic_ref(&ref
, BTRFS_DROP_DELAYED_REF
, old_bytenr
,
1368 btrfs_init_tree_ref(&ref
, level
- 1, dest
->root_key
.objectid
);
1369 ref
.skip_qgroup
= true;
1370 ret
= btrfs_free_extent(trans
, &ref
);
1373 btrfs_unlock_up_safe(path
, 0);
1378 btrfs_tree_unlock(parent
);
1379 free_extent_buffer(parent
);
1384 * helper to find next relocated block in reloc tree
1386 static noinline_for_stack
1387 int walk_up_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1390 struct extent_buffer
*eb
;
1395 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1397 for (i
= 0; i
< *level
; i
++) {
1398 free_extent_buffer(path
->nodes
[i
]);
1399 path
->nodes
[i
] = NULL
;
1402 for (i
= *level
; i
< BTRFS_MAX_LEVEL
&& path
->nodes
[i
]; i
++) {
1403 eb
= path
->nodes
[i
];
1404 nritems
= btrfs_header_nritems(eb
);
1405 while (path
->slots
[i
] + 1 < nritems
) {
1407 if (btrfs_node_ptr_generation(eb
, path
->slots
[i
]) <=
1414 free_extent_buffer(path
->nodes
[i
]);
1415 path
->nodes
[i
] = NULL
;
1421 * walk down reloc tree to find relocated block of lowest level
1423 static noinline_for_stack
1424 int walk_down_reloc_tree(struct btrfs_root
*root
, struct btrfs_path
*path
,
1427 struct extent_buffer
*eb
= NULL
;
1433 last_snapshot
= btrfs_root_last_snapshot(&root
->root_item
);
1435 for (i
= *level
; i
> 0; i
--) {
1436 eb
= path
->nodes
[i
];
1437 nritems
= btrfs_header_nritems(eb
);
1438 while (path
->slots
[i
] < nritems
) {
1439 ptr_gen
= btrfs_node_ptr_generation(eb
, path
->slots
[i
]);
1440 if (ptr_gen
> last_snapshot
)
1444 if (path
->slots
[i
] >= nritems
) {
1455 eb
= btrfs_read_node_slot(eb
, path
->slots
[i
]);
1458 BUG_ON(btrfs_header_level(eb
) != i
- 1);
1459 path
->nodes
[i
- 1] = eb
;
1460 path
->slots
[i
- 1] = 0;
1466 * invalidate extent cache for file extents whose key in range of
1467 * [min_key, max_key)
1469 static int invalidate_extent_cache(struct btrfs_root
*root
,
1470 struct btrfs_key
*min_key
,
1471 struct btrfs_key
*max_key
)
1473 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1474 struct inode
*inode
= NULL
;
1479 objectid
= min_key
->objectid
;
1484 if (objectid
> max_key
->objectid
)
1487 inode
= find_next_inode(root
, objectid
);
1490 ino
= btrfs_ino(BTRFS_I(inode
));
1492 if (ino
> max_key
->objectid
) {
1498 if (!S_ISREG(inode
->i_mode
))
1501 if (unlikely(min_key
->objectid
== ino
)) {
1502 if (min_key
->type
> BTRFS_EXTENT_DATA_KEY
)
1504 if (min_key
->type
< BTRFS_EXTENT_DATA_KEY
)
1507 start
= min_key
->offset
;
1508 WARN_ON(!IS_ALIGNED(start
, fs_info
->sectorsize
));
1514 if (unlikely(max_key
->objectid
== ino
)) {
1515 if (max_key
->type
< BTRFS_EXTENT_DATA_KEY
)
1517 if (max_key
->type
> BTRFS_EXTENT_DATA_KEY
) {
1520 if (max_key
->offset
== 0)
1522 end
= max_key
->offset
;
1523 WARN_ON(!IS_ALIGNED(end
, fs_info
->sectorsize
));
1530 /* the lock_extent waits for readpage to complete */
1531 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
1532 btrfs_drop_extent_cache(BTRFS_I(inode
), start
, end
, 1);
1533 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
1538 static int find_next_key(struct btrfs_path
*path
, int level
,
1539 struct btrfs_key
*key
)
1542 while (level
< BTRFS_MAX_LEVEL
) {
1543 if (!path
->nodes
[level
])
1545 if (path
->slots
[level
] + 1 <
1546 btrfs_header_nritems(path
->nodes
[level
])) {
1547 btrfs_node_key_to_cpu(path
->nodes
[level
], key
,
1548 path
->slots
[level
] + 1);
1557 * Insert current subvolume into reloc_control::dirty_subvol_roots
1559 static void insert_dirty_subvol(struct btrfs_trans_handle
*trans
,
1560 struct reloc_control
*rc
,
1561 struct btrfs_root
*root
)
1563 struct btrfs_root
*reloc_root
= root
->reloc_root
;
1564 struct btrfs_root_item
*reloc_root_item
;
1566 /* @root must be a subvolume tree root with a valid reloc tree */
1567 ASSERT(root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
);
1570 reloc_root_item
= &reloc_root
->root_item
;
1571 memset(&reloc_root_item
->drop_progress
, 0,
1572 sizeof(reloc_root_item
->drop_progress
));
1573 btrfs_set_root_drop_level(reloc_root_item
, 0);
1574 btrfs_set_root_refs(reloc_root_item
, 0);
1575 btrfs_update_reloc_root(trans
, root
);
1577 if (list_empty(&root
->reloc_dirty_list
)) {
1578 btrfs_grab_root(root
);
1579 list_add_tail(&root
->reloc_dirty_list
, &rc
->dirty_subvol_roots
);
1583 static int clean_dirty_subvols(struct reloc_control
*rc
)
1585 struct btrfs_root
*root
;
1586 struct btrfs_root
*next
;
1590 list_for_each_entry_safe(root
, next
, &rc
->dirty_subvol_roots
,
1592 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
) {
1593 /* Merged subvolume, cleanup its reloc root */
1594 struct btrfs_root
*reloc_root
= root
->reloc_root
;
1596 list_del_init(&root
->reloc_dirty_list
);
1597 root
->reloc_root
= NULL
;
1599 * Need barrier to ensure clear_bit() only happens after
1600 * root->reloc_root = NULL. Pairs with have_reloc_root.
1603 clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE
, &root
->state
);
1606 * btrfs_drop_snapshot drops our ref we hold for
1607 * ->reloc_root. If it fails however we must
1608 * drop the ref ourselves.
1610 ret2
= btrfs_drop_snapshot(reloc_root
, 0, 1);
1612 btrfs_put_root(reloc_root
);
1617 btrfs_put_root(root
);
1619 /* Orphan reloc tree, just clean it up */
1620 ret2
= btrfs_drop_snapshot(root
, 0, 1);
1622 btrfs_put_root(root
);
1632 * merge the relocated tree blocks in reloc tree with corresponding
1635 static noinline_for_stack
int merge_reloc_root(struct reloc_control
*rc
,
1636 struct btrfs_root
*root
)
1638 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
1639 struct btrfs_key key
;
1640 struct btrfs_key next_key
;
1641 struct btrfs_trans_handle
*trans
= NULL
;
1642 struct btrfs_root
*reloc_root
;
1643 struct btrfs_root_item
*root_item
;
1644 struct btrfs_path
*path
;
1645 struct extent_buffer
*leaf
;
1653 path
= btrfs_alloc_path();
1656 path
->reada
= READA_FORWARD
;
1658 reloc_root
= root
->reloc_root
;
1659 root_item
= &reloc_root
->root_item
;
1661 if (btrfs_disk_key_objectid(&root_item
->drop_progress
) == 0) {
1662 level
= btrfs_root_level(root_item
);
1663 atomic_inc(&reloc_root
->node
->refs
);
1664 path
->nodes
[level
] = reloc_root
->node
;
1665 path
->slots
[level
] = 0;
1667 btrfs_disk_key_to_cpu(&key
, &root_item
->drop_progress
);
1669 level
= btrfs_root_drop_level(root_item
);
1671 path
->lowest_level
= level
;
1672 ret
= btrfs_search_slot(NULL
, reloc_root
, &key
, path
, 0, 0);
1673 path
->lowest_level
= 0;
1675 btrfs_free_path(path
);
1679 btrfs_node_key_to_cpu(path
->nodes
[level
], &next_key
,
1680 path
->slots
[level
]);
1681 WARN_ON(memcmp(&key
, &next_key
, sizeof(key
)));
1683 btrfs_unlock_up_safe(path
, 0);
1687 * In merge_reloc_root(), we modify the upper level pointer to swap the
1688 * tree blocks between reloc tree and subvolume tree. Thus for tree
1689 * block COW, we COW at most from level 1 to root level for each tree.
1691 * Thus the needed metadata size is at most root_level * nodesize,
1692 * and * 2 since we have two trees to COW.
1694 reserve_level
= max_t(int, 1, btrfs_root_level(root_item
));
1695 min_reserved
= fs_info
->nodesize
* reserve_level
* 2;
1696 memset(&next_key
, 0, sizeof(next_key
));
1699 ret
= btrfs_block_rsv_refill(root
, rc
->block_rsv
, min_reserved
,
1700 BTRFS_RESERVE_FLUSH_LIMIT
);
1703 trans
= btrfs_start_transaction(root
, 0);
1704 if (IS_ERR(trans
)) {
1705 ret
= PTR_ERR(trans
);
1711 * At this point we no longer have a reloc_control, so we can't
1712 * depend on btrfs_init_reloc_root to update our last_trans.
1714 * But that's ok, we started the trans handle on our
1715 * corresponding fs_root, which means it's been added to the
1716 * dirty list. At commit time we'll still call
1717 * btrfs_update_reloc_root() and update our root item
1720 reloc_root
->last_trans
= trans
->transid
;
1721 trans
->block_rsv
= rc
->block_rsv
;
1726 ret
= walk_down_reloc_tree(reloc_root
, path
, &level
);
1732 if (!find_next_key(path
, level
, &key
) &&
1733 btrfs_comp_cpu_keys(&next_key
, &key
) >= 0) {
1736 ret
= replace_path(trans
, rc
, root
, reloc_root
, path
,
1737 &next_key
, level
, max_level
);
1743 btrfs_node_key_to_cpu(path
->nodes
[level
], &key
,
1744 path
->slots
[level
]);
1748 ret
= walk_up_reloc_tree(reloc_root
, path
, &level
);
1754 * save the merging progress in the drop_progress.
1755 * this is OK since root refs == 1 in this case.
1757 btrfs_node_key(path
->nodes
[level
], &root_item
->drop_progress
,
1758 path
->slots
[level
]);
1759 btrfs_set_root_drop_level(root_item
, level
);
1761 btrfs_end_transaction_throttle(trans
);
1764 btrfs_btree_balance_dirty(fs_info
);
1766 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
1767 invalidate_extent_cache(root
, &key
, &next_key
);
1771 * handle the case only one block in the fs tree need to be
1772 * relocated and the block is tree root.
1774 leaf
= btrfs_lock_root_node(root
);
1775 ret
= btrfs_cow_block(trans
, root
, leaf
, NULL
, 0, &leaf
,
1777 btrfs_tree_unlock(leaf
);
1778 free_extent_buffer(leaf
);
1780 btrfs_free_path(path
);
1783 insert_dirty_subvol(trans
, rc
, root
);
1786 btrfs_end_transaction_throttle(trans
);
1788 btrfs_btree_balance_dirty(fs_info
);
1790 if (replaced
&& rc
->stage
== UPDATE_DATA_PTRS
)
1791 invalidate_extent_cache(root
, &key
, &next_key
);
1796 static noinline_for_stack
1797 int prepare_to_merge(struct reloc_control
*rc
, int err
)
1799 struct btrfs_root
*root
= rc
->extent_root
;
1800 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
1801 struct btrfs_root
*reloc_root
;
1802 struct btrfs_trans_handle
*trans
;
1803 LIST_HEAD(reloc_roots
);
1807 mutex_lock(&fs_info
->reloc_mutex
);
1808 rc
->merging_rsv_size
+= fs_info
->nodesize
* (BTRFS_MAX_LEVEL
- 1) * 2;
1809 rc
->merging_rsv_size
+= rc
->nodes_relocated
* 2;
1810 mutex_unlock(&fs_info
->reloc_mutex
);
1814 num_bytes
= rc
->merging_rsv_size
;
1815 ret
= btrfs_block_rsv_add(root
, rc
->block_rsv
, num_bytes
,
1816 BTRFS_RESERVE_FLUSH_ALL
);
1821 trans
= btrfs_join_transaction(rc
->extent_root
);
1822 if (IS_ERR(trans
)) {
1824 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
,
1826 return PTR_ERR(trans
);
1830 if (num_bytes
!= rc
->merging_rsv_size
) {
1831 btrfs_end_transaction(trans
);
1832 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
,
1838 rc
->merge_reloc_tree
= 1;
1840 while (!list_empty(&rc
->reloc_roots
)) {
1841 reloc_root
= list_entry(rc
->reloc_roots
.next
,
1842 struct btrfs_root
, root_list
);
1843 list_del_init(&reloc_root
->root_list
);
1845 root
= btrfs_get_fs_root(fs_info
, reloc_root
->root_key
.offset
,
1847 BUG_ON(IS_ERR(root
));
1848 BUG_ON(root
->reloc_root
!= reloc_root
);
1851 * set reference count to 1, so btrfs_recover_relocation
1852 * knows it should resumes merging
1855 btrfs_set_root_refs(&reloc_root
->root_item
, 1);
1856 btrfs_update_reloc_root(trans
, root
);
1858 list_add(&reloc_root
->root_list
, &reloc_roots
);
1859 btrfs_put_root(root
);
1862 list_splice(&reloc_roots
, &rc
->reloc_roots
);
1865 btrfs_commit_transaction(trans
);
1867 btrfs_end_transaction(trans
);
1871 static noinline_for_stack
1872 void free_reloc_roots(struct list_head
*list
)
1874 struct btrfs_root
*reloc_root
, *tmp
;
1876 list_for_each_entry_safe(reloc_root
, tmp
, list
, root_list
)
1877 __del_reloc_root(reloc_root
);
1880 static noinline_for_stack
1881 void merge_reloc_roots(struct reloc_control
*rc
)
1883 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
1884 struct btrfs_root
*root
;
1885 struct btrfs_root
*reloc_root
;
1886 LIST_HEAD(reloc_roots
);
1890 root
= rc
->extent_root
;
1893 * this serializes us with btrfs_record_root_in_transaction,
1894 * we have to make sure nobody is in the middle of
1895 * adding their roots to the list while we are
1898 mutex_lock(&fs_info
->reloc_mutex
);
1899 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
1900 mutex_unlock(&fs_info
->reloc_mutex
);
1902 while (!list_empty(&reloc_roots
)) {
1904 reloc_root
= list_entry(reloc_roots
.next
,
1905 struct btrfs_root
, root_list
);
1907 root
= btrfs_get_fs_root(fs_info
, reloc_root
->root_key
.offset
,
1909 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
1910 BUG_ON(IS_ERR(root
));
1911 BUG_ON(root
->reloc_root
!= reloc_root
);
1912 ret
= merge_reloc_root(rc
, root
);
1913 btrfs_put_root(root
);
1915 if (list_empty(&reloc_root
->root_list
))
1916 list_add_tail(&reloc_root
->root_list
,
1921 if (!IS_ERR(root
)) {
1922 if (root
->reloc_root
== reloc_root
) {
1923 root
->reloc_root
= NULL
;
1924 btrfs_put_root(reloc_root
);
1926 clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE
,
1928 btrfs_put_root(root
);
1931 list_del_init(&reloc_root
->root_list
);
1932 /* Don't forget to queue this reloc root for cleanup */
1933 list_add_tail(&reloc_root
->reloc_dirty_list
,
1934 &rc
->dirty_subvol_roots
);
1944 btrfs_handle_fs_error(fs_info
, ret
, NULL
);
1945 free_reloc_roots(&reloc_roots
);
1947 /* new reloc root may be added */
1948 mutex_lock(&fs_info
->reloc_mutex
);
1949 list_splice_init(&rc
->reloc_roots
, &reloc_roots
);
1950 mutex_unlock(&fs_info
->reloc_mutex
);
1951 free_reloc_roots(&reloc_roots
);
1957 * BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
1959 * here, but it's wrong. If we fail to start the transaction in
1960 * prepare_to_merge() we will have only 0 ref reloc roots, none of which
1961 * have actually been removed from the reloc_root_tree rb tree. This is
1962 * fine because we're bailing here, and we hold a reference on the root
1963 * for the list that holds it, so these roots will be cleaned up when we
1964 * do the reloc_dirty_list afterwards. Meanwhile the root->reloc_root
1965 * will be cleaned up on unmount.
1967 * The remaining nodes will be cleaned up by free_reloc_control.
1971 static void free_block_list(struct rb_root
*blocks
)
1973 struct tree_block
*block
;
1974 struct rb_node
*rb_node
;
1975 while ((rb_node
= rb_first(blocks
))) {
1976 block
= rb_entry(rb_node
, struct tree_block
, rb_node
);
1977 rb_erase(rb_node
, blocks
);
1982 static int record_reloc_root_in_trans(struct btrfs_trans_handle
*trans
,
1983 struct btrfs_root
*reloc_root
)
1985 struct btrfs_fs_info
*fs_info
= reloc_root
->fs_info
;
1986 struct btrfs_root
*root
;
1989 if (reloc_root
->last_trans
== trans
->transid
)
1992 root
= btrfs_get_fs_root(fs_info
, reloc_root
->root_key
.offset
, false);
1993 BUG_ON(IS_ERR(root
));
1994 BUG_ON(root
->reloc_root
!= reloc_root
);
1995 ret
= btrfs_record_root_in_trans(trans
, root
);
1996 btrfs_put_root(root
);
2001 static noinline_for_stack
2002 struct btrfs_root
*select_reloc_root(struct btrfs_trans_handle
*trans
,
2003 struct reloc_control
*rc
,
2004 struct btrfs_backref_node
*node
,
2005 struct btrfs_backref_edge
*edges
[])
2007 struct btrfs_backref_node
*next
;
2008 struct btrfs_root
*root
;
2014 next
= walk_up_backref(next
, edges
, &index
);
2017 BUG_ON(!test_bit(BTRFS_ROOT_SHAREABLE
, &root
->state
));
2019 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
) {
2020 record_reloc_root_in_trans(trans
, root
);
2024 btrfs_record_root_in_trans(trans
, root
);
2025 root
= root
->reloc_root
;
2027 if (next
->new_bytenr
!= root
->node
->start
) {
2028 BUG_ON(next
->new_bytenr
);
2029 BUG_ON(!list_empty(&next
->list
));
2030 next
->new_bytenr
= root
->node
->start
;
2031 btrfs_put_root(next
->root
);
2032 next
->root
= btrfs_grab_root(root
);
2034 list_add_tail(&next
->list
,
2035 &rc
->backref_cache
.changed
);
2036 mark_block_processed(rc
, next
);
2042 next
= walk_down_backref(edges
, &index
);
2043 if (!next
|| next
->level
<= node
->level
)
2050 /* setup backref node path for btrfs_reloc_cow_block */
2052 rc
->backref_cache
.path
[next
->level
] = next
;
2055 next
= edges
[index
]->node
[UPPER
];
2061 * Select a tree root for relocation.
2063 * Return NULL if the block is not shareable. We should use do_relocation() in
2066 * Return a tree root pointer if the block is shareable.
2067 * Return -ENOENT if the block is root of reloc tree.
2069 static noinline_for_stack
2070 struct btrfs_root
*select_one_root(struct btrfs_backref_node
*node
)
2072 struct btrfs_backref_node
*next
;
2073 struct btrfs_root
*root
;
2074 struct btrfs_root
*fs_root
= NULL
;
2075 struct btrfs_backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2081 next
= walk_up_backref(next
, edges
, &index
);
2085 /* No other choice for non-shareable tree */
2086 if (!test_bit(BTRFS_ROOT_SHAREABLE
, &root
->state
))
2089 if (root
->root_key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
)
2095 next
= walk_down_backref(edges
, &index
);
2096 if (!next
|| next
->level
<= node
->level
)
2101 return ERR_PTR(-ENOENT
);
2105 static noinline_for_stack
2106 u64
calcu_metadata_size(struct reloc_control
*rc
,
2107 struct btrfs_backref_node
*node
, int reserve
)
2109 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
2110 struct btrfs_backref_node
*next
= node
;
2111 struct btrfs_backref_edge
*edge
;
2112 struct btrfs_backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2116 BUG_ON(reserve
&& node
->processed
);
2121 if (next
->processed
&& (reserve
|| next
!= node
))
2124 num_bytes
+= fs_info
->nodesize
;
2126 if (list_empty(&next
->upper
))
2129 edge
= list_entry(next
->upper
.next
,
2130 struct btrfs_backref_edge
, list
[LOWER
]);
2131 edges
[index
++] = edge
;
2132 next
= edge
->node
[UPPER
];
2134 next
= walk_down_backref(edges
, &index
);
2139 static int reserve_metadata_space(struct btrfs_trans_handle
*trans
,
2140 struct reloc_control
*rc
,
2141 struct btrfs_backref_node
*node
)
2143 struct btrfs_root
*root
= rc
->extent_root
;
2144 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
2149 num_bytes
= calcu_metadata_size(rc
, node
, 1) * 2;
2151 trans
->block_rsv
= rc
->block_rsv
;
2152 rc
->reserved_bytes
+= num_bytes
;
2155 * We are under a transaction here so we can only do limited flushing.
2156 * If we get an enospc just kick back -EAGAIN so we know to drop the
2157 * transaction and try to refill when we can flush all the things.
2159 ret
= btrfs_block_rsv_refill(root
, rc
->block_rsv
, num_bytes
,
2160 BTRFS_RESERVE_FLUSH_LIMIT
);
2162 tmp
= fs_info
->nodesize
* RELOCATION_RESERVED_NODES
;
2163 while (tmp
<= rc
->reserved_bytes
)
2166 * only one thread can access block_rsv at this point,
2167 * so we don't need hold lock to protect block_rsv.
2168 * we expand more reservation size here to allow enough
2169 * space for relocation and we will return earlier in
2172 rc
->block_rsv
->size
= tmp
+ fs_info
->nodesize
*
2173 RELOCATION_RESERVED_NODES
;
2181 * relocate a block tree, and then update pointers in upper level
2182 * blocks that reference the block to point to the new location.
2184 * if called by link_to_upper, the block has already been relocated.
2185 * in that case this function just updates pointers.
2187 static int do_relocation(struct btrfs_trans_handle
*trans
,
2188 struct reloc_control
*rc
,
2189 struct btrfs_backref_node
*node
,
2190 struct btrfs_key
*key
,
2191 struct btrfs_path
*path
, int lowest
)
2193 struct btrfs_backref_node
*upper
;
2194 struct btrfs_backref_edge
*edge
;
2195 struct btrfs_backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2196 struct btrfs_root
*root
;
2197 struct extent_buffer
*eb
;
2203 BUG_ON(lowest
&& node
->eb
);
2205 path
->lowest_level
= node
->level
+ 1;
2206 rc
->backref_cache
.path
[node
->level
] = node
;
2207 list_for_each_entry(edge
, &node
->upper
, list
[LOWER
]) {
2208 struct btrfs_ref ref
= { 0 };
2212 upper
= edge
->node
[UPPER
];
2213 root
= select_reloc_root(trans
, rc
, upper
, edges
);
2216 if (upper
->eb
&& !upper
->locked
) {
2218 ret
= btrfs_bin_search(upper
->eb
, key
, &slot
);
2222 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2223 if (node
->eb
->start
== bytenr
)
2226 btrfs_backref_drop_node_buffer(upper
);
2230 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2235 btrfs_release_path(path
);
2240 upper
->eb
= path
->nodes
[upper
->level
];
2241 path
->nodes
[upper
->level
] = NULL
;
2243 BUG_ON(upper
->eb
!= path
->nodes
[upper
->level
]);
2247 path
->locks
[upper
->level
] = 0;
2249 slot
= path
->slots
[upper
->level
];
2250 btrfs_release_path(path
);
2252 ret
= btrfs_bin_search(upper
->eb
, key
, &slot
);
2258 bytenr
= btrfs_node_blockptr(upper
->eb
, slot
);
2260 if (bytenr
!= node
->bytenr
) {
2261 btrfs_err(root
->fs_info
,
2262 "lowest leaf/node mismatch: bytenr %llu node->bytenr %llu slot %d upper %llu",
2263 bytenr
, node
->bytenr
, slot
,
2269 if (node
->eb
->start
== bytenr
)
2273 blocksize
= root
->fs_info
->nodesize
;
2274 eb
= btrfs_read_node_slot(upper
->eb
, slot
);
2279 btrfs_tree_lock(eb
);
2282 ret
= btrfs_cow_block(trans
, root
, eb
, upper
->eb
,
2283 slot
, &eb
, BTRFS_NESTING_COW
);
2284 btrfs_tree_unlock(eb
);
2285 free_extent_buffer(eb
);
2288 BUG_ON(node
->eb
!= eb
);
2290 btrfs_set_node_blockptr(upper
->eb
, slot
,
2292 btrfs_set_node_ptr_generation(upper
->eb
, slot
,
2294 btrfs_mark_buffer_dirty(upper
->eb
);
2296 btrfs_init_generic_ref(&ref
, BTRFS_ADD_DELAYED_REF
,
2297 node
->eb
->start
, blocksize
,
2299 ref
.real_root
= root
->root_key
.objectid
;
2300 btrfs_init_tree_ref(&ref
, node
->level
,
2301 btrfs_header_owner(upper
->eb
));
2302 ret
= btrfs_inc_extent_ref(trans
, &ref
);
2305 ret
= btrfs_drop_subtree(trans
, root
, eb
, upper
->eb
);
2309 if (!upper
->pending
)
2310 btrfs_backref_drop_node_buffer(upper
);
2312 btrfs_backref_unlock_node_buffer(upper
);
2317 if (!ret
&& node
->pending
) {
2318 btrfs_backref_drop_node_buffer(node
);
2319 list_move_tail(&node
->list
, &rc
->backref_cache
.changed
);
2323 path
->lowest_level
= 0;
2324 BUG_ON(ret
== -ENOSPC
);
2328 static int link_to_upper(struct btrfs_trans_handle
*trans
,
2329 struct reloc_control
*rc
,
2330 struct btrfs_backref_node
*node
,
2331 struct btrfs_path
*path
)
2333 struct btrfs_key key
;
2335 btrfs_node_key_to_cpu(node
->eb
, &key
, 0);
2336 return do_relocation(trans
, rc
, node
, &key
, path
, 0);
2339 static int finish_pending_nodes(struct btrfs_trans_handle
*trans
,
2340 struct reloc_control
*rc
,
2341 struct btrfs_path
*path
, int err
)
2344 struct btrfs_backref_cache
*cache
= &rc
->backref_cache
;
2345 struct btrfs_backref_node
*node
;
2349 for (level
= 0; level
< BTRFS_MAX_LEVEL
; level
++) {
2350 while (!list_empty(&cache
->pending
[level
])) {
2351 node
= list_entry(cache
->pending
[level
].next
,
2352 struct btrfs_backref_node
, list
);
2353 list_move_tail(&node
->list
, &list
);
2354 BUG_ON(!node
->pending
);
2357 ret
= link_to_upper(trans
, rc
, node
, path
);
2362 list_splice_init(&list
, &cache
->pending
[level
]);
2368 * mark a block and all blocks directly/indirectly reference the block
2371 static void update_processed_blocks(struct reloc_control
*rc
,
2372 struct btrfs_backref_node
*node
)
2374 struct btrfs_backref_node
*next
= node
;
2375 struct btrfs_backref_edge
*edge
;
2376 struct btrfs_backref_edge
*edges
[BTRFS_MAX_LEVEL
- 1];
2382 if (next
->processed
)
2385 mark_block_processed(rc
, next
);
2387 if (list_empty(&next
->upper
))
2390 edge
= list_entry(next
->upper
.next
,
2391 struct btrfs_backref_edge
, list
[LOWER
]);
2392 edges
[index
++] = edge
;
2393 next
= edge
->node
[UPPER
];
2395 next
= walk_down_backref(edges
, &index
);
2399 static int tree_block_processed(u64 bytenr
, struct reloc_control
*rc
)
2401 u32 blocksize
= rc
->extent_root
->fs_info
->nodesize
;
2403 if (test_range_bit(&rc
->processed_blocks
, bytenr
,
2404 bytenr
+ blocksize
- 1, EXTENT_DIRTY
, 1, NULL
))
2409 static int get_tree_block_key(struct btrfs_fs_info
*fs_info
,
2410 struct tree_block
*block
)
2412 struct extent_buffer
*eb
;
2414 eb
= read_tree_block(fs_info
, block
->bytenr
, 0, block
->key
.offset
,
2415 block
->level
, NULL
);
2418 } else if (!extent_buffer_uptodate(eb
)) {
2419 free_extent_buffer(eb
);
2422 if (block
->level
== 0)
2423 btrfs_item_key_to_cpu(eb
, &block
->key
, 0);
2425 btrfs_node_key_to_cpu(eb
, &block
->key
, 0);
2426 free_extent_buffer(eb
);
2427 block
->key_ready
= 1;
2432 * helper function to relocate a tree block
2434 static int relocate_tree_block(struct btrfs_trans_handle
*trans
,
2435 struct reloc_control
*rc
,
2436 struct btrfs_backref_node
*node
,
2437 struct btrfs_key
*key
,
2438 struct btrfs_path
*path
)
2440 struct btrfs_root
*root
;
2447 * If we fail here we want to drop our backref_node because we are going
2448 * to start over and regenerate the tree for it.
2450 ret
= reserve_metadata_space(trans
, rc
, node
);
2454 BUG_ON(node
->processed
);
2455 root
= select_one_root(node
);
2456 if (root
== ERR_PTR(-ENOENT
)) {
2457 update_processed_blocks(rc
, node
);
2462 if (test_bit(BTRFS_ROOT_SHAREABLE
, &root
->state
)) {
2463 BUG_ON(node
->new_bytenr
);
2464 BUG_ON(!list_empty(&node
->list
));
2465 btrfs_record_root_in_trans(trans
, root
);
2466 root
= root
->reloc_root
;
2467 node
->new_bytenr
= root
->node
->start
;
2468 btrfs_put_root(node
->root
);
2469 node
->root
= btrfs_grab_root(root
);
2471 list_add_tail(&node
->list
, &rc
->backref_cache
.changed
);
2473 path
->lowest_level
= node
->level
;
2474 ret
= btrfs_search_slot(trans
, root
, key
, path
, 0, 1);
2475 btrfs_release_path(path
);
2480 update_processed_blocks(rc
, node
);
2482 ret
= do_relocation(trans
, rc
, node
, key
, path
, 1);
2485 if (ret
|| node
->level
== 0 || node
->cowonly
)
2486 btrfs_backref_cleanup_node(&rc
->backref_cache
, node
);
2491 * relocate a list of blocks
2493 static noinline_for_stack
2494 int relocate_tree_blocks(struct btrfs_trans_handle
*trans
,
2495 struct reloc_control
*rc
, struct rb_root
*blocks
)
2497 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
2498 struct btrfs_backref_node
*node
;
2499 struct btrfs_path
*path
;
2500 struct tree_block
*block
;
2501 struct tree_block
*next
;
2505 path
= btrfs_alloc_path();
2508 goto out_free_blocks
;
2511 /* Kick in readahead for tree blocks with missing keys */
2512 rbtree_postorder_for_each_entry_safe(block
, next
, blocks
, rb_node
) {
2513 if (!block
->key_ready
)
2514 btrfs_readahead_tree_block(fs_info
, block
->bytenr
, 0, 0,
2518 /* Get first keys */
2519 rbtree_postorder_for_each_entry_safe(block
, next
, blocks
, rb_node
) {
2520 if (!block
->key_ready
) {
2521 err
= get_tree_block_key(fs_info
, block
);
2527 /* Do tree relocation */
2528 rbtree_postorder_for_each_entry_safe(block
, next
, blocks
, rb_node
) {
2529 node
= build_backref_tree(rc
, &block
->key
,
2530 block
->level
, block
->bytenr
);
2532 err
= PTR_ERR(node
);
2536 ret
= relocate_tree_block(trans
, rc
, node
, &block
->key
,
2544 err
= finish_pending_nodes(trans
, rc
, path
, err
);
2547 btrfs_free_path(path
);
2549 free_block_list(blocks
);
2553 static noinline_for_stack
int prealloc_file_extent_cluster(
2554 struct btrfs_inode
*inode
,
2555 struct file_extent_cluster
*cluster
)
2560 u64 offset
= inode
->index_cnt
;
2564 u64 prealloc_start
= cluster
->start
- offset
;
2565 u64 prealloc_end
= cluster
->end
- offset
;
2566 u64 cur_offset
= prealloc_start
;
2568 BUG_ON(cluster
->start
!= cluster
->boundary
[0]);
2569 ret
= btrfs_alloc_data_chunk_ondemand(inode
,
2570 prealloc_end
+ 1 - prealloc_start
);
2574 inode_lock(&inode
->vfs_inode
);
2575 for (nr
= 0; nr
< cluster
->nr
; nr
++) {
2576 start
= cluster
->boundary
[nr
] - offset
;
2577 if (nr
+ 1 < cluster
->nr
)
2578 end
= cluster
->boundary
[nr
+ 1] - 1 - offset
;
2580 end
= cluster
->end
- offset
;
2582 lock_extent(&inode
->io_tree
, start
, end
);
2583 num_bytes
= end
+ 1 - start
;
2584 ret
= btrfs_prealloc_file_range(&inode
->vfs_inode
, 0, start
,
2585 num_bytes
, num_bytes
,
2586 end
+ 1, &alloc_hint
);
2587 cur_offset
= end
+ 1;
2588 unlock_extent(&inode
->io_tree
, start
, end
);
2592 inode_unlock(&inode
->vfs_inode
);
2594 if (cur_offset
< prealloc_end
)
2595 btrfs_free_reserved_data_space_noquota(inode
->root
->fs_info
,
2596 prealloc_end
+ 1 - cur_offset
);
2600 static noinline_for_stack
2601 int setup_extent_mapping(struct inode
*inode
, u64 start
, u64 end
,
2604 struct extent_map_tree
*em_tree
= &BTRFS_I(inode
)->extent_tree
;
2605 struct extent_map
*em
;
2608 em
= alloc_extent_map();
2613 em
->len
= end
+ 1 - start
;
2614 em
->block_len
= em
->len
;
2615 em
->block_start
= block_start
;
2616 set_bit(EXTENT_FLAG_PINNED
, &em
->flags
);
2618 lock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2620 write_lock(&em_tree
->lock
);
2621 ret
= add_extent_mapping(em_tree
, em
, 0);
2622 write_unlock(&em_tree
->lock
);
2623 if (ret
!= -EEXIST
) {
2624 free_extent_map(em
);
2627 btrfs_drop_extent_cache(BTRFS_I(inode
), start
, end
, 0);
2629 unlock_extent(&BTRFS_I(inode
)->io_tree
, start
, end
);
2634 * Allow error injection to test balance cancellation
2636 int btrfs_should_cancel_balance(struct btrfs_fs_info
*fs_info
)
2638 return atomic_read(&fs_info
->balance_cancel_req
) ||
2639 fatal_signal_pending(current
);
2641 ALLOW_ERROR_INJECTION(btrfs_should_cancel_balance
, TRUE
);
2643 static int relocate_file_extent_cluster(struct inode
*inode
,
2644 struct file_extent_cluster
*cluster
)
2646 struct btrfs_fs_info
*fs_info
= btrfs_sb(inode
->i_sb
);
2649 u64 offset
= BTRFS_I(inode
)->index_cnt
;
2650 unsigned long index
;
2651 unsigned long last_index
;
2653 struct file_ra_state
*ra
;
2654 gfp_t mask
= btrfs_alloc_write_mask(inode
->i_mapping
);
2661 ra
= kzalloc(sizeof(*ra
), GFP_NOFS
);
2665 ret
= prealloc_file_extent_cluster(BTRFS_I(inode
), cluster
);
2669 file_ra_state_init(ra
, inode
->i_mapping
);
2671 ret
= setup_extent_mapping(inode
, cluster
->start
- offset
,
2672 cluster
->end
- offset
, cluster
->start
);
2676 index
= (cluster
->start
- offset
) >> PAGE_SHIFT
;
2677 last_index
= (cluster
->end
- offset
) >> PAGE_SHIFT
;
2678 while (index
<= last_index
) {
2679 ret
= btrfs_delalloc_reserve_metadata(BTRFS_I(inode
),
2684 page
= find_lock_page(inode
->i_mapping
, index
);
2686 page_cache_sync_readahead(inode
->i_mapping
,
2688 last_index
+ 1 - index
);
2689 page
= find_or_create_page(inode
->i_mapping
, index
,
2692 btrfs_delalloc_release_metadata(BTRFS_I(inode
),
2694 btrfs_delalloc_release_extents(BTRFS_I(inode
),
2701 if (PageReadahead(page
)) {
2702 page_cache_async_readahead(inode
->i_mapping
,
2703 ra
, NULL
, page
, index
,
2704 last_index
+ 1 - index
);
2707 if (!PageUptodate(page
)) {
2708 btrfs_readpage(NULL
, page
);
2710 if (!PageUptodate(page
)) {
2713 btrfs_delalloc_release_metadata(BTRFS_I(inode
),
2715 btrfs_delalloc_release_extents(BTRFS_I(inode
),
2722 page_start
= page_offset(page
);
2723 page_end
= page_start
+ PAGE_SIZE
- 1;
2725 lock_extent(&BTRFS_I(inode
)->io_tree
, page_start
, page_end
);
2727 set_page_extent_mapped(page
);
2729 if (nr
< cluster
->nr
&&
2730 page_start
+ offset
== cluster
->boundary
[nr
]) {
2731 set_extent_bits(&BTRFS_I(inode
)->io_tree
,
2732 page_start
, page_end
,
2737 ret
= btrfs_set_extent_delalloc(BTRFS_I(inode
), page_start
,
2742 btrfs_delalloc_release_metadata(BTRFS_I(inode
),
2744 btrfs_delalloc_release_extents(BTRFS_I(inode
),
2747 clear_extent_bits(&BTRFS_I(inode
)->io_tree
,
2748 page_start
, page_end
,
2749 EXTENT_LOCKED
| EXTENT_BOUNDARY
);
2753 set_page_dirty(page
);
2755 unlock_extent(&BTRFS_I(inode
)->io_tree
,
2756 page_start
, page_end
);
2761 btrfs_delalloc_release_extents(BTRFS_I(inode
), PAGE_SIZE
);
2762 balance_dirty_pages_ratelimited(inode
->i_mapping
);
2763 btrfs_throttle(fs_info
);
2764 if (btrfs_should_cancel_balance(fs_info
)) {
2769 WARN_ON(nr
!= cluster
->nr
);
2775 static noinline_for_stack
2776 int relocate_data_extent(struct inode
*inode
, struct btrfs_key
*extent_key
,
2777 struct file_extent_cluster
*cluster
)
2781 if (cluster
->nr
> 0 && extent_key
->objectid
!= cluster
->end
+ 1) {
2782 ret
= relocate_file_extent_cluster(inode
, cluster
);
2789 cluster
->start
= extent_key
->objectid
;
2791 BUG_ON(cluster
->nr
>= MAX_EXTENTS
);
2792 cluster
->end
= extent_key
->objectid
+ extent_key
->offset
- 1;
2793 cluster
->boundary
[cluster
->nr
] = extent_key
->objectid
;
2796 if (cluster
->nr
>= MAX_EXTENTS
) {
2797 ret
= relocate_file_extent_cluster(inode
, cluster
);
2806 * helper to add a tree block to the list.
2807 * the major work is getting the generation and level of the block
2809 static int add_tree_block(struct reloc_control
*rc
,
2810 struct btrfs_key
*extent_key
,
2811 struct btrfs_path
*path
,
2812 struct rb_root
*blocks
)
2814 struct extent_buffer
*eb
;
2815 struct btrfs_extent_item
*ei
;
2816 struct btrfs_tree_block_info
*bi
;
2817 struct tree_block
*block
;
2818 struct rb_node
*rb_node
;
2823 eb
= path
->nodes
[0];
2824 item_size
= btrfs_item_size_nr(eb
, path
->slots
[0]);
2826 if (extent_key
->type
== BTRFS_METADATA_ITEM_KEY
||
2827 item_size
>= sizeof(*ei
) + sizeof(*bi
)) {
2828 ei
= btrfs_item_ptr(eb
, path
->slots
[0],
2829 struct btrfs_extent_item
);
2830 if (extent_key
->type
== BTRFS_EXTENT_ITEM_KEY
) {
2831 bi
= (struct btrfs_tree_block_info
*)(ei
+ 1);
2832 level
= btrfs_tree_block_level(eb
, bi
);
2834 level
= (int)extent_key
->offset
;
2836 generation
= btrfs_extent_generation(eb
, ei
);
2837 } else if (unlikely(item_size
== sizeof(struct btrfs_extent_item_v0
))) {
2838 btrfs_print_v0_err(eb
->fs_info
);
2839 btrfs_handle_fs_error(eb
->fs_info
, -EINVAL
, NULL
);
2845 btrfs_release_path(path
);
2847 BUG_ON(level
== -1);
2849 block
= kmalloc(sizeof(*block
), GFP_NOFS
);
2853 block
->bytenr
= extent_key
->objectid
;
2854 block
->key
.objectid
= rc
->extent_root
->fs_info
->nodesize
;
2855 block
->key
.offset
= generation
;
2856 block
->level
= level
;
2857 block
->key_ready
= 0;
2859 rb_node
= rb_simple_insert(blocks
, block
->bytenr
, &block
->rb_node
);
2861 btrfs_backref_panic(rc
->extent_root
->fs_info
, block
->bytenr
,
2868 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
2870 static int __add_tree_block(struct reloc_control
*rc
,
2871 u64 bytenr
, u32 blocksize
,
2872 struct rb_root
*blocks
)
2874 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
2875 struct btrfs_path
*path
;
2876 struct btrfs_key key
;
2878 bool skinny
= btrfs_fs_incompat(fs_info
, SKINNY_METADATA
);
2880 if (tree_block_processed(bytenr
, rc
))
2883 if (rb_simple_search(blocks
, bytenr
))
2886 path
= btrfs_alloc_path();
2890 key
.objectid
= bytenr
;
2892 key
.type
= BTRFS_METADATA_ITEM_KEY
;
2893 key
.offset
= (u64
)-1;
2895 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
2896 key
.offset
= blocksize
;
2899 path
->search_commit_root
= 1;
2900 path
->skip_locking
= 1;
2901 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
, 0, 0);
2905 if (ret
> 0 && skinny
) {
2906 if (path
->slots
[0]) {
2908 btrfs_item_key_to_cpu(path
->nodes
[0], &key
,
2910 if (key
.objectid
== bytenr
&&
2911 (key
.type
== BTRFS_METADATA_ITEM_KEY
||
2912 (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
2913 key
.offset
== blocksize
)))
2919 btrfs_release_path(path
);
2925 btrfs_print_leaf(path
->nodes
[0]);
2927 "tree block extent item (%llu) is not found in extent tree",
2934 ret
= add_tree_block(rc
, &key
, path
, blocks
);
2936 btrfs_free_path(path
);
2940 static int delete_block_group_cache(struct btrfs_fs_info
*fs_info
,
2941 struct btrfs_block_group
*block_group
,
2942 struct inode
*inode
,
2945 struct btrfs_root
*root
= fs_info
->tree_root
;
2946 struct btrfs_trans_handle
*trans
;
2952 inode
= btrfs_iget(fs_info
->sb
, ino
, root
);
2957 ret
= btrfs_check_trunc_cache_free_space(fs_info
,
2958 &fs_info
->global_block_rsv
);
2962 trans
= btrfs_join_transaction(root
);
2963 if (IS_ERR(trans
)) {
2964 ret
= PTR_ERR(trans
);
2968 ret
= btrfs_truncate_free_space_cache(trans
, block_group
, inode
);
2970 btrfs_end_transaction(trans
);
2971 btrfs_btree_balance_dirty(fs_info
);
2978 * Locate the free space cache EXTENT_DATA in root tree leaf and delete the
2979 * cache inode, to avoid free space cache data extent blocking data relocation.
2981 static int delete_v1_space_cache(struct extent_buffer
*leaf
,
2982 struct btrfs_block_group
*block_group
,
2985 u64 space_cache_ino
;
2986 struct btrfs_file_extent_item
*ei
;
2987 struct btrfs_key key
;
2992 if (btrfs_header_owner(leaf
) != BTRFS_ROOT_TREE_OBJECTID
)
2995 for (i
= 0; i
< btrfs_header_nritems(leaf
); i
++) {
2998 btrfs_item_key_to_cpu(leaf
, &key
, i
);
2999 if (key
.type
!= BTRFS_EXTENT_DATA_KEY
)
3001 ei
= btrfs_item_ptr(leaf
, i
, struct btrfs_file_extent_item
);
3002 type
= btrfs_file_extent_type(leaf
, ei
);
3004 if ((type
== BTRFS_FILE_EXTENT_REG
||
3005 type
== BTRFS_FILE_EXTENT_PREALLOC
) &&
3006 btrfs_file_extent_disk_bytenr(leaf
, ei
) == data_bytenr
) {
3008 space_cache_ino
= key
.objectid
;
3014 ret
= delete_block_group_cache(leaf
->fs_info
, block_group
, NULL
,
3020 * helper to find all tree blocks that reference a given data extent
3022 static noinline_for_stack
3023 int add_data_references(struct reloc_control
*rc
,
3024 struct btrfs_key
*extent_key
,
3025 struct btrfs_path
*path
,
3026 struct rb_root
*blocks
)
3028 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3029 struct ulist
*leaves
= NULL
;
3030 struct ulist_iterator leaf_uiter
;
3031 struct ulist_node
*ref_node
= NULL
;
3032 const u32 blocksize
= fs_info
->nodesize
;
3035 btrfs_release_path(path
);
3036 ret
= btrfs_find_all_leafs(NULL
, fs_info
, extent_key
->objectid
,
3037 0, &leaves
, NULL
, true);
3041 ULIST_ITER_INIT(&leaf_uiter
);
3042 while ((ref_node
= ulist_next(leaves
, &leaf_uiter
))) {
3043 struct extent_buffer
*eb
;
3045 eb
= read_tree_block(fs_info
, ref_node
->val
, 0, 0, 0, NULL
);
3050 ret
= delete_v1_space_cache(eb
, rc
->block_group
,
3051 extent_key
->objectid
);
3052 free_extent_buffer(eb
);
3055 ret
= __add_tree_block(rc
, ref_node
->val
, blocksize
, blocks
);
3060 free_block_list(blocks
);
3066 * helper to find next unprocessed extent
3068 static noinline_for_stack
3069 int find_next_extent(struct reloc_control
*rc
, struct btrfs_path
*path
,
3070 struct btrfs_key
*extent_key
)
3072 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3073 struct btrfs_key key
;
3074 struct extent_buffer
*leaf
;
3075 u64 start
, end
, last
;
3078 last
= rc
->block_group
->start
+ rc
->block_group
->length
;
3081 if (rc
->search_start
>= last
) {
3086 key
.objectid
= rc
->search_start
;
3087 key
.type
= BTRFS_EXTENT_ITEM_KEY
;
3090 path
->search_commit_root
= 1;
3091 path
->skip_locking
= 1;
3092 ret
= btrfs_search_slot(NULL
, rc
->extent_root
, &key
, path
,
3097 leaf
= path
->nodes
[0];
3098 if (path
->slots
[0] >= btrfs_header_nritems(leaf
)) {
3099 ret
= btrfs_next_leaf(rc
->extent_root
, path
);
3102 leaf
= path
->nodes
[0];
3105 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3106 if (key
.objectid
>= last
) {
3111 if (key
.type
!= BTRFS_EXTENT_ITEM_KEY
&&
3112 key
.type
!= BTRFS_METADATA_ITEM_KEY
) {
3117 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
&&
3118 key
.objectid
+ key
.offset
<= rc
->search_start
) {
3123 if (key
.type
== BTRFS_METADATA_ITEM_KEY
&&
3124 key
.objectid
+ fs_info
->nodesize
<=
3130 ret
= find_first_extent_bit(&rc
->processed_blocks
,
3131 key
.objectid
, &start
, &end
,
3132 EXTENT_DIRTY
, NULL
);
3134 if (ret
== 0 && start
<= key
.objectid
) {
3135 btrfs_release_path(path
);
3136 rc
->search_start
= end
+ 1;
3138 if (key
.type
== BTRFS_EXTENT_ITEM_KEY
)
3139 rc
->search_start
= key
.objectid
+ key
.offset
;
3141 rc
->search_start
= key
.objectid
+
3143 memcpy(extent_key
, &key
, sizeof(key
));
3147 btrfs_release_path(path
);
3151 static void set_reloc_control(struct reloc_control
*rc
)
3153 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3155 mutex_lock(&fs_info
->reloc_mutex
);
3156 fs_info
->reloc_ctl
= rc
;
3157 mutex_unlock(&fs_info
->reloc_mutex
);
3160 static void unset_reloc_control(struct reloc_control
*rc
)
3162 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3164 mutex_lock(&fs_info
->reloc_mutex
);
3165 fs_info
->reloc_ctl
= NULL
;
3166 mutex_unlock(&fs_info
->reloc_mutex
);
3169 static int check_extent_flags(u64 flags
)
3171 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3172 (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3174 if (!(flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3175 !(flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
))
3177 if ((flags
& BTRFS_EXTENT_FLAG_DATA
) &&
3178 (flags
& BTRFS_BLOCK_FLAG_FULL_BACKREF
))
3183 static noinline_for_stack
3184 int prepare_to_relocate(struct reloc_control
*rc
)
3186 struct btrfs_trans_handle
*trans
;
3189 rc
->block_rsv
= btrfs_alloc_block_rsv(rc
->extent_root
->fs_info
,
3190 BTRFS_BLOCK_RSV_TEMP
);
3194 memset(&rc
->cluster
, 0, sizeof(rc
->cluster
));
3195 rc
->search_start
= rc
->block_group
->start
;
3196 rc
->extents_found
= 0;
3197 rc
->nodes_relocated
= 0;
3198 rc
->merging_rsv_size
= 0;
3199 rc
->reserved_bytes
= 0;
3200 rc
->block_rsv
->size
= rc
->extent_root
->fs_info
->nodesize
*
3201 RELOCATION_RESERVED_NODES
;
3202 ret
= btrfs_block_rsv_refill(rc
->extent_root
,
3203 rc
->block_rsv
, rc
->block_rsv
->size
,
3204 BTRFS_RESERVE_FLUSH_ALL
);
3208 rc
->create_reloc_tree
= 1;
3209 set_reloc_control(rc
);
3211 trans
= btrfs_join_transaction(rc
->extent_root
);
3212 if (IS_ERR(trans
)) {
3213 unset_reloc_control(rc
);
3215 * extent tree is not a ref_cow tree and has no reloc_root to
3216 * cleanup. And callers are responsible to free the above
3219 return PTR_ERR(trans
);
3221 btrfs_commit_transaction(trans
);
3225 static noinline_for_stack
int relocate_block_group(struct reloc_control
*rc
)
3227 struct btrfs_fs_info
*fs_info
= rc
->extent_root
->fs_info
;
3228 struct rb_root blocks
= RB_ROOT
;
3229 struct btrfs_key key
;
3230 struct btrfs_trans_handle
*trans
= NULL
;
3231 struct btrfs_path
*path
;
3232 struct btrfs_extent_item
*ei
;
3239 path
= btrfs_alloc_path();
3242 path
->reada
= READA_FORWARD
;
3244 ret
= prepare_to_relocate(rc
);
3251 rc
->reserved_bytes
= 0;
3252 ret
= btrfs_block_rsv_refill(rc
->extent_root
,
3253 rc
->block_rsv
, rc
->block_rsv
->size
,
3254 BTRFS_RESERVE_FLUSH_ALL
);
3260 trans
= btrfs_start_transaction(rc
->extent_root
, 0);
3261 if (IS_ERR(trans
)) {
3262 err
= PTR_ERR(trans
);
3267 if (update_backref_cache(trans
, &rc
->backref_cache
)) {
3268 btrfs_end_transaction(trans
);
3273 ret
= find_next_extent(rc
, path
, &key
);
3279 rc
->extents_found
++;
3281 ei
= btrfs_item_ptr(path
->nodes
[0], path
->slots
[0],
3282 struct btrfs_extent_item
);
3283 item_size
= btrfs_item_size_nr(path
->nodes
[0], path
->slots
[0]);
3284 if (item_size
>= sizeof(*ei
)) {
3285 flags
= btrfs_extent_flags(path
->nodes
[0], ei
);
3286 ret
= check_extent_flags(flags
);
3288 } else if (unlikely(item_size
== sizeof(struct btrfs_extent_item_v0
))) {
3290 btrfs_print_v0_err(trans
->fs_info
);
3291 btrfs_abort_transaction(trans
, err
);
3297 if (flags
& BTRFS_EXTENT_FLAG_TREE_BLOCK
) {
3298 ret
= add_tree_block(rc
, &key
, path
, &blocks
);
3299 } else if (rc
->stage
== UPDATE_DATA_PTRS
&&
3300 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
3301 ret
= add_data_references(rc
, &key
, path
, &blocks
);
3303 btrfs_release_path(path
);
3311 if (!RB_EMPTY_ROOT(&blocks
)) {
3312 ret
= relocate_tree_blocks(trans
, rc
, &blocks
);
3314 if (ret
!= -EAGAIN
) {
3318 rc
->extents_found
--;
3319 rc
->search_start
= key
.objectid
;
3323 btrfs_end_transaction_throttle(trans
);
3324 btrfs_btree_balance_dirty(fs_info
);
3327 if (rc
->stage
== MOVE_DATA_EXTENTS
&&
3328 (flags
& BTRFS_EXTENT_FLAG_DATA
)) {
3329 rc
->found_file_extent
= 1;
3330 ret
= relocate_data_extent(rc
->data_inode
,
3331 &key
, &rc
->cluster
);
3337 if (btrfs_should_cancel_balance(fs_info
)) {
3342 if (trans
&& progress
&& err
== -ENOSPC
) {
3343 ret
= btrfs_force_chunk_alloc(trans
, rc
->block_group
->flags
);
3351 btrfs_release_path(path
);
3352 clear_extent_bits(&rc
->processed_blocks
, 0, (u64
)-1, EXTENT_DIRTY
);
3355 btrfs_end_transaction_throttle(trans
);
3356 btrfs_btree_balance_dirty(fs_info
);
3360 ret
= relocate_file_extent_cluster(rc
->data_inode
,
3366 rc
->create_reloc_tree
= 0;
3367 set_reloc_control(rc
);
3369 btrfs_backref_release_cache(&rc
->backref_cache
);
3370 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
, (u64
)-1, NULL
);
3373 * Even in the case when the relocation is cancelled, we should all go
3374 * through prepare_to_merge() and merge_reloc_roots().
3376 * For error (including cancelled balance), prepare_to_merge() will
3377 * mark all reloc trees orphan, then queue them for cleanup in
3378 * merge_reloc_roots()
3380 err
= prepare_to_merge(rc
, err
);
3382 merge_reloc_roots(rc
);
3384 rc
->merge_reloc_tree
= 0;
3385 unset_reloc_control(rc
);
3386 btrfs_block_rsv_release(fs_info
, rc
->block_rsv
, (u64
)-1, NULL
);
3388 /* get rid of pinned extents */
3389 trans
= btrfs_join_transaction(rc
->extent_root
);
3390 if (IS_ERR(trans
)) {
3391 err
= PTR_ERR(trans
);
3394 btrfs_commit_transaction(trans
);
3396 ret
= clean_dirty_subvols(rc
);
3397 if (ret
< 0 && !err
)
3399 btrfs_free_block_rsv(fs_info
, rc
->block_rsv
);
3400 btrfs_free_path(path
);
3404 static int __insert_orphan_inode(struct btrfs_trans_handle
*trans
,
3405 struct btrfs_root
*root
, u64 objectid
)
3407 struct btrfs_path
*path
;
3408 struct btrfs_inode_item
*item
;
3409 struct extent_buffer
*leaf
;
3412 path
= btrfs_alloc_path();
3416 ret
= btrfs_insert_empty_inode(trans
, root
, path
, objectid
);
3420 leaf
= path
->nodes
[0];
3421 item
= btrfs_item_ptr(leaf
, path
->slots
[0], struct btrfs_inode_item
);
3422 memzero_extent_buffer(leaf
, (unsigned long)item
, sizeof(*item
));
3423 btrfs_set_inode_generation(leaf
, item
, 1);
3424 btrfs_set_inode_size(leaf
, item
, 0);
3425 btrfs_set_inode_mode(leaf
, item
, S_IFREG
| 0600);
3426 btrfs_set_inode_flags(leaf
, item
, BTRFS_INODE_NOCOMPRESS
|
3427 BTRFS_INODE_PREALLOC
);
3428 btrfs_mark_buffer_dirty(leaf
);
3430 btrfs_free_path(path
);
3435 * helper to create inode for data relocation.
3436 * the inode is in data relocation tree and its link count is 0
3438 static noinline_for_stack
3439 struct inode
*create_reloc_inode(struct btrfs_fs_info
*fs_info
,
3440 struct btrfs_block_group
*group
)
3442 struct inode
*inode
= NULL
;
3443 struct btrfs_trans_handle
*trans
;
3444 struct btrfs_root
*root
;
3448 root
= btrfs_grab_root(fs_info
->data_reloc_root
);
3449 trans
= btrfs_start_transaction(root
, 6);
3450 if (IS_ERR(trans
)) {
3451 btrfs_put_root(root
);
3452 return ERR_CAST(trans
);
3455 err
= btrfs_find_free_objectid(root
, &objectid
);
3459 err
= __insert_orphan_inode(trans
, root
, objectid
);
3462 inode
= btrfs_iget(fs_info
->sb
, objectid
, root
);
3463 BUG_ON(IS_ERR(inode
));
3464 BTRFS_I(inode
)->index_cnt
= group
->start
;
3466 err
= btrfs_orphan_add(trans
, BTRFS_I(inode
));
3468 btrfs_put_root(root
);
3469 btrfs_end_transaction(trans
);
3470 btrfs_btree_balance_dirty(fs_info
);
3474 inode
= ERR_PTR(err
);
3479 static struct reloc_control
*alloc_reloc_control(struct btrfs_fs_info
*fs_info
)
3481 struct reloc_control
*rc
;
3483 rc
= kzalloc(sizeof(*rc
), GFP_NOFS
);
3487 INIT_LIST_HEAD(&rc
->reloc_roots
);
3488 INIT_LIST_HEAD(&rc
->dirty_subvol_roots
);
3489 btrfs_backref_init_cache(fs_info
, &rc
->backref_cache
, 1);
3490 mapping_tree_init(&rc
->reloc_root_tree
);
3491 extent_io_tree_init(fs_info
, &rc
->processed_blocks
,
3492 IO_TREE_RELOC_BLOCKS
, NULL
);
3496 static void free_reloc_control(struct reloc_control
*rc
)
3498 struct mapping_node
*node
, *tmp
;
3500 free_reloc_roots(&rc
->reloc_roots
);
3501 rbtree_postorder_for_each_entry_safe(node
, tmp
,
3502 &rc
->reloc_root_tree
.rb_root
, rb_node
)
3509 * Print the block group being relocated
3511 static void describe_relocation(struct btrfs_fs_info
*fs_info
,
3512 struct btrfs_block_group
*block_group
)
3514 char buf
[128] = {'\0'};
3516 btrfs_describe_block_groups(block_group
->flags
, buf
, sizeof(buf
));
3519 "relocating block group %llu flags %s",
3520 block_group
->start
, buf
);
3523 static const char *stage_to_string(int stage
)
3525 if (stage
== MOVE_DATA_EXTENTS
)
3526 return "move data extents";
3527 if (stage
== UPDATE_DATA_PTRS
)
3528 return "update data pointers";
3533 * function to relocate all extents in a block group.
3535 int btrfs_relocate_block_group(struct btrfs_fs_info
*fs_info
, u64 group_start
)
3537 struct btrfs_block_group
*bg
;
3538 struct btrfs_root
*extent_root
= fs_info
->extent_root
;
3539 struct reloc_control
*rc
;
3540 struct inode
*inode
;
3541 struct btrfs_path
*path
;
3546 bg
= btrfs_lookup_block_group(fs_info
, group_start
);
3550 if (btrfs_pinned_by_swapfile(fs_info
, bg
)) {
3551 btrfs_put_block_group(bg
);
3555 rc
= alloc_reloc_control(fs_info
);
3557 btrfs_put_block_group(bg
);
3561 rc
->extent_root
= extent_root
;
3562 rc
->block_group
= bg
;
3564 ret
= btrfs_inc_block_group_ro(rc
->block_group
, true);
3571 path
= btrfs_alloc_path();
3577 inode
= lookup_free_space_inode(rc
->block_group
, path
);
3578 btrfs_free_path(path
);
3581 ret
= delete_block_group_cache(fs_info
, rc
->block_group
, inode
, 0);
3583 ret
= PTR_ERR(inode
);
3585 if (ret
&& ret
!= -ENOENT
) {
3590 rc
->data_inode
= create_reloc_inode(fs_info
, rc
->block_group
);
3591 if (IS_ERR(rc
->data_inode
)) {
3592 err
= PTR_ERR(rc
->data_inode
);
3593 rc
->data_inode
= NULL
;
3597 describe_relocation(fs_info
, rc
->block_group
);
3599 btrfs_wait_block_group_reservations(rc
->block_group
);
3600 btrfs_wait_nocow_writers(rc
->block_group
);
3601 btrfs_wait_ordered_roots(fs_info
, U64_MAX
,
3602 rc
->block_group
->start
,
3603 rc
->block_group
->length
);
3608 mutex_lock(&fs_info
->cleaner_mutex
);
3609 ret
= relocate_block_group(rc
);
3610 mutex_unlock(&fs_info
->cleaner_mutex
);
3614 finishes_stage
= rc
->stage
;
3616 * We may have gotten ENOSPC after we already dirtied some
3617 * extents. If writeout happens while we're relocating a
3618 * different block group we could end up hitting the
3619 * BUG_ON(rc->stage == UPDATE_DATA_PTRS) in
3620 * btrfs_reloc_cow_block. Make sure we write everything out
3621 * properly so we don't trip over this problem, and then break
3622 * out of the loop if we hit an error.
3624 if (rc
->stage
== MOVE_DATA_EXTENTS
&& rc
->found_file_extent
) {
3625 ret
= btrfs_wait_ordered_range(rc
->data_inode
, 0,
3629 invalidate_mapping_pages(rc
->data_inode
->i_mapping
,
3631 rc
->stage
= UPDATE_DATA_PTRS
;
3637 if (rc
->extents_found
== 0)
3640 btrfs_info(fs_info
, "found %llu extents, stage: %s",
3641 rc
->extents_found
, stage_to_string(finishes_stage
));
3644 WARN_ON(rc
->block_group
->pinned
> 0);
3645 WARN_ON(rc
->block_group
->reserved
> 0);
3646 WARN_ON(rc
->block_group
->used
> 0);
3649 btrfs_dec_block_group_ro(rc
->block_group
);
3650 iput(rc
->data_inode
);
3651 btrfs_put_block_group(rc
->block_group
);
3652 free_reloc_control(rc
);
3656 static noinline_for_stack
int mark_garbage_root(struct btrfs_root
*root
)
3658 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
3659 struct btrfs_trans_handle
*trans
;
3662 trans
= btrfs_start_transaction(fs_info
->tree_root
, 0);
3664 return PTR_ERR(trans
);
3666 memset(&root
->root_item
.drop_progress
, 0,
3667 sizeof(root
->root_item
.drop_progress
));
3668 btrfs_set_root_drop_level(&root
->root_item
, 0);
3669 btrfs_set_root_refs(&root
->root_item
, 0);
3670 ret
= btrfs_update_root(trans
, fs_info
->tree_root
,
3671 &root
->root_key
, &root
->root_item
);
3673 err
= btrfs_end_transaction(trans
);
3680 * recover relocation interrupted by system crash.
3682 * this function resumes merging reloc trees with corresponding fs trees.
3683 * this is important for keeping the sharing of tree blocks
3685 int btrfs_recover_relocation(struct btrfs_root
*root
)
3687 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
3688 LIST_HEAD(reloc_roots
);
3689 struct btrfs_key key
;
3690 struct btrfs_root
*fs_root
;
3691 struct btrfs_root
*reloc_root
;
3692 struct btrfs_path
*path
;
3693 struct extent_buffer
*leaf
;
3694 struct reloc_control
*rc
= NULL
;
3695 struct btrfs_trans_handle
*trans
;
3699 path
= btrfs_alloc_path();
3702 path
->reada
= READA_BACK
;
3704 key
.objectid
= BTRFS_TREE_RELOC_OBJECTID
;
3705 key
.type
= BTRFS_ROOT_ITEM_KEY
;
3706 key
.offset
= (u64
)-1;
3709 ret
= btrfs_search_slot(NULL
, fs_info
->tree_root
, &key
,
3716 if (path
->slots
[0] == 0)
3720 leaf
= path
->nodes
[0];
3721 btrfs_item_key_to_cpu(leaf
, &key
, path
->slots
[0]);
3722 btrfs_release_path(path
);
3724 if (key
.objectid
!= BTRFS_TREE_RELOC_OBJECTID
||
3725 key
.type
!= BTRFS_ROOT_ITEM_KEY
)
3728 reloc_root
= btrfs_read_tree_root(root
, &key
);
3729 if (IS_ERR(reloc_root
)) {
3730 err
= PTR_ERR(reloc_root
);
3734 set_bit(BTRFS_ROOT_SHAREABLE
, &reloc_root
->state
);
3735 list_add(&reloc_root
->root_list
, &reloc_roots
);
3737 if (btrfs_root_refs(&reloc_root
->root_item
) > 0) {
3738 fs_root
= btrfs_get_fs_root(fs_info
,
3739 reloc_root
->root_key
.offset
, false);
3740 if (IS_ERR(fs_root
)) {
3741 ret
= PTR_ERR(fs_root
);
3742 if (ret
!= -ENOENT
) {
3746 ret
= mark_garbage_root(reloc_root
);
3752 btrfs_put_root(fs_root
);
3756 if (key
.offset
== 0)
3761 btrfs_release_path(path
);
3763 if (list_empty(&reloc_roots
))
3766 rc
= alloc_reloc_control(fs_info
);
3772 rc
->extent_root
= fs_info
->extent_root
;
3774 set_reloc_control(rc
);
3776 trans
= btrfs_join_transaction(rc
->extent_root
);
3777 if (IS_ERR(trans
)) {
3778 err
= PTR_ERR(trans
);
3782 rc
->merge_reloc_tree
= 1;
3784 while (!list_empty(&reloc_roots
)) {
3785 reloc_root
= list_entry(reloc_roots
.next
,
3786 struct btrfs_root
, root_list
);
3787 list_del(&reloc_root
->root_list
);
3789 if (btrfs_root_refs(&reloc_root
->root_item
) == 0) {
3790 list_add_tail(&reloc_root
->root_list
,
3795 fs_root
= btrfs_get_fs_root(fs_info
, reloc_root
->root_key
.offset
,
3797 if (IS_ERR(fs_root
)) {
3798 err
= PTR_ERR(fs_root
);
3799 list_add_tail(&reloc_root
->root_list
, &reloc_roots
);
3800 btrfs_end_transaction(trans
);
3804 err
= __add_reloc_root(reloc_root
);
3805 BUG_ON(err
< 0); /* -ENOMEM or logic error */
3806 fs_root
->reloc_root
= btrfs_grab_root(reloc_root
);
3807 btrfs_put_root(fs_root
);
3810 err
= btrfs_commit_transaction(trans
);
3814 merge_reloc_roots(rc
);
3816 unset_reloc_control(rc
);
3818 trans
= btrfs_join_transaction(rc
->extent_root
);
3819 if (IS_ERR(trans
)) {
3820 err
= PTR_ERR(trans
);
3823 err
= btrfs_commit_transaction(trans
);
3825 ret
= clean_dirty_subvols(rc
);
3826 if (ret
< 0 && !err
)
3829 unset_reloc_control(rc
);
3830 free_reloc_control(rc
);
3832 free_reloc_roots(&reloc_roots
);
3834 btrfs_free_path(path
);
3837 /* cleanup orphan inode in data relocation tree */
3838 fs_root
= btrfs_grab_root(fs_info
->data_reloc_root
);
3840 err
= btrfs_orphan_cleanup(fs_root
);
3841 btrfs_put_root(fs_root
);
3847 * helper to add ordered checksum for data relocation.
3849 * cloning checksum properly handles the nodatasum extents.
3850 * it also saves CPU time to re-calculate the checksum.
3852 int btrfs_reloc_clone_csums(struct btrfs_inode
*inode
, u64 file_pos
, u64 len
)
3854 struct btrfs_fs_info
*fs_info
= inode
->root
->fs_info
;
3855 struct btrfs_ordered_sum
*sums
;
3856 struct btrfs_ordered_extent
*ordered
;
3862 ordered
= btrfs_lookup_ordered_extent(inode
, file_pos
);
3863 BUG_ON(ordered
->file_offset
!= file_pos
|| ordered
->num_bytes
!= len
);
3865 disk_bytenr
= file_pos
+ inode
->index_cnt
;
3866 ret
= btrfs_lookup_csums_range(fs_info
->csum_root
, disk_bytenr
,
3867 disk_bytenr
+ len
- 1, &list
, 0);
3871 while (!list_empty(&list
)) {
3872 sums
= list_entry(list
.next
, struct btrfs_ordered_sum
, list
);
3873 list_del_init(&sums
->list
);
3876 * We need to offset the new_bytenr based on where the csum is.
3877 * We need to do this because we will read in entire prealloc
3878 * extents but we may have written to say the middle of the
3879 * prealloc extent, so we need to make sure the csum goes with
3880 * the right disk offset.
3882 * We can do this because the data reloc inode refers strictly
3883 * to the on disk bytes, so we don't have to worry about
3884 * disk_len vs real len like with real inodes since it's all
3887 new_bytenr
= ordered
->disk_bytenr
+ sums
->bytenr
- disk_bytenr
;
3888 sums
->bytenr
= new_bytenr
;
3890 btrfs_add_ordered_sum(ordered
, sums
);
3893 btrfs_put_ordered_extent(ordered
);
3897 int btrfs_reloc_cow_block(struct btrfs_trans_handle
*trans
,
3898 struct btrfs_root
*root
, struct extent_buffer
*buf
,
3899 struct extent_buffer
*cow
)
3901 struct btrfs_fs_info
*fs_info
= root
->fs_info
;
3902 struct reloc_control
*rc
;
3903 struct btrfs_backref_node
*node
;
3908 rc
= fs_info
->reloc_ctl
;
3912 BUG_ON(rc
->stage
== UPDATE_DATA_PTRS
&&
3913 root
->root_key
.objectid
== BTRFS_DATA_RELOC_TREE_OBJECTID
);
3915 level
= btrfs_header_level(buf
);
3916 if (btrfs_header_generation(buf
) <=
3917 btrfs_root_last_snapshot(&root
->root_item
))
3920 if (root
->root_key
.objectid
== BTRFS_TREE_RELOC_OBJECTID
&&
3921 rc
->create_reloc_tree
) {
3922 WARN_ON(!first_cow
&& level
== 0);
3924 node
= rc
->backref_cache
.path
[level
];
3925 BUG_ON(node
->bytenr
!= buf
->start
&&
3926 node
->new_bytenr
!= buf
->start
);
3928 btrfs_backref_drop_node_buffer(node
);
3929 atomic_inc(&cow
->refs
);
3931 node
->new_bytenr
= cow
->start
;
3933 if (!node
->pending
) {
3934 list_move_tail(&node
->list
,
3935 &rc
->backref_cache
.pending
[level
]);
3940 mark_block_processed(rc
, node
);
3942 if (first_cow
&& level
> 0)
3943 rc
->nodes_relocated
+= buf
->len
;
3946 if (level
== 0 && first_cow
&& rc
->stage
== UPDATE_DATA_PTRS
)
3947 ret
= replace_file_extents(trans
, rc
, root
, cow
);
3952 * called before creating snapshot. it calculates metadata reservation
3953 * required for relocating tree blocks in the snapshot
3955 void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot
*pending
,
3956 u64
*bytes_to_reserve
)
3958 struct btrfs_root
*root
= pending
->root
;
3959 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
3961 if (!rc
|| !have_reloc_root(root
))
3964 if (!rc
->merge_reloc_tree
)
3967 root
= root
->reloc_root
;
3968 BUG_ON(btrfs_root_refs(&root
->root_item
) == 0);
3970 * relocation is in the stage of merging trees. the space
3971 * used by merging a reloc tree is twice the size of
3972 * relocated tree nodes in the worst case. half for cowing
3973 * the reloc tree, half for cowing the fs tree. the space
3974 * used by cowing the reloc tree will be freed after the
3975 * tree is dropped. if we create snapshot, cowing the fs
3976 * tree may use more space than it frees. so we need
3977 * reserve extra space.
3979 *bytes_to_reserve
+= rc
->nodes_relocated
;
3983 * called after snapshot is created. migrate block reservation
3984 * and create reloc root for the newly created snapshot
3986 * This is similar to btrfs_init_reloc_root(), we come out of here with two
3987 * references held on the reloc_root, one for root->reloc_root and one for
3990 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle
*trans
,
3991 struct btrfs_pending_snapshot
*pending
)
3993 struct btrfs_root
*root
= pending
->root
;
3994 struct btrfs_root
*reloc_root
;
3995 struct btrfs_root
*new_root
;
3996 struct reloc_control
*rc
= root
->fs_info
->reloc_ctl
;
3999 if (!rc
|| !have_reloc_root(root
))
4002 rc
= root
->fs_info
->reloc_ctl
;
4003 rc
->merging_rsv_size
+= rc
->nodes_relocated
;
4005 if (rc
->merge_reloc_tree
) {
4006 ret
= btrfs_block_rsv_migrate(&pending
->block_rsv
,
4008 rc
->nodes_relocated
, true);
4013 new_root
= pending
->snap
;
4014 reloc_root
= create_reloc_root(trans
, root
->reloc_root
,
4015 new_root
->root_key
.objectid
);
4016 if (IS_ERR(reloc_root
))
4017 return PTR_ERR(reloc_root
);
4019 ret
= __add_reloc_root(reloc_root
);
4021 new_root
->reloc_root
= btrfs_grab_root(reloc_root
);
4023 if (rc
->create_reloc_tree
)
4024 ret
= clone_backref_node(trans
, rc
, root
, reloc_root
);