2 * Copyright (C) 2009 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
27 #include "transaction.h"
30 #include "btrfs_inode.h"
31 #include "async-thread.h"
32 #include "free-space-cache.h"
33 #include "inode-map.h"
36 * backref_node, mapping_node and tree_block start with this
39 struct rb_node rb_node;
44 * present a tree block in the backref cache
47 struct rb_node rb_node;
51 /* objectid of tree block owner, can be not uptodate */
53 /* link to pending, changed or detached list */
54 struct list_head list;
55 /* list of upper level blocks reference this block */
56 struct list_head upper;
57 /* list of child blocks in the cache */
58 struct list_head lower;
59 /* NULL if this node is not tree root */
60 struct btrfs_root *root;
61 /* extent buffer got by COW the block */
62 struct extent_buffer *eb;
63 /* level of tree block */
65 /* is the block in non-reference counted tree */
66 unsigned int cowonly:1;
67 /* 1 if no child node in the cache */
68 unsigned int lowest:1;
69 /* is the extent buffer locked */
70 unsigned int locked:1;
71 /* has the block been processed */
72 unsigned int processed:1;
73 /* have backrefs of this block been checked */
74 unsigned int checked:1;
76 * 1 if corresponding block has been cowed but some upper
77 * level block pointers may not point to the new location
79 unsigned int pending:1;
81 * 1 if the backref node isn't connected to any other
84 unsigned int detached:1;
88 * present a block pointer in the backref cache
91 struct list_head list[2];
92 struct backref_node *node[2];
97 #define RELOCATION_RESERVED_NODES 256
99 struct backref_cache {
100 /* red black tree of all backref nodes in the cache */
101 struct rb_root rb_root;
102 /* for passing backref nodes to btrfs_reloc_cow_block */
103 struct backref_node *path[BTRFS_MAX_LEVEL];
105 * list of blocks that have been cowed but some block
106 * pointers in upper level blocks may not reflect the
109 struct list_head pending[BTRFS_MAX_LEVEL];
110 /* list of backref nodes with no child node */
111 struct list_head leaves;
112 /* list of blocks that have been cowed in current transaction */
113 struct list_head changed;
114 /* list of detached backref node. */
115 struct list_head detached;
124 * map address of tree root to tree
126 struct mapping_node {
127 struct rb_node rb_node;
132 struct mapping_tree {
133 struct rb_root rb_root;
138 * present a tree block to process
141 struct rb_node rb_node;
143 struct btrfs_key key;
144 unsigned int level:8;
145 unsigned int key_ready:1;
148 #define MAX_EXTENTS 128
150 struct file_extent_cluster {
153 u64 boundary[MAX_EXTENTS];
157 struct reloc_control {
158 /* block group to relocate */
159 struct btrfs_block_group_cache *block_group;
161 struct btrfs_root *extent_root;
162 /* inode for moving data */
163 struct inode *data_inode;
165 struct btrfs_block_rsv *block_rsv;
167 struct backref_cache backref_cache;
169 struct file_extent_cluster cluster;
170 /* tree blocks have been processed */
171 struct extent_io_tree processed_blocks;
172 /* map start of tree root to corresponding reloc tree */
173 struct mapping_tree reloc_root_tree;
174 /* list of reloc trees */
175 struct list_head reloc_roots;
176 /* size of metadata reservation for merging reloc trees */
177 u64 merging_rsv_size;
178 /* size of relocated tree nodes */
180 /* reserved size for block group relocation*/
186 unsigned int stage:8;
187 unsigned int create_reloc_tree:1;
188 unsigned int merge_reloc_tree:1;
189 unsigned int found_file_extent:1;
192 /* stages of data relocation */
193 #define MOVE_DATA_EXTENTS 0
194 #define UPDATE_DATA_PTRS 1
196 static void remove_backref_node(struct backref_cache *cache,
197 struct backref_node *node);
198 static void __mark_block_processed(struct reloc_control *rc,
199 struct backref_node *node);
201 static void mapping_tree_init(struct mapping_tree *tree)
203 tree->rb_root = RB_ROOT;
204 spin_lock_init(&tree->lock);
207 static void backref_cache_init(struct backref_cache *cache)
210 cache->rb_root = RB_ROOT;
211 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
212 INIT_LIST_HEAD(&cache->pending[i]);
213 INIT_LIST_HEAD(&cache->changed);
214 INIT_LIST_HEAD(&cache->detached);
215 INIT_LIST_HEAD(&cache->leaves);
218 static void backref_cache_cleanup(struct backref_cache *cache)
220 struct backref_node *node;
223 while (!list_empty(&cache->detached)) {
224 node = list_entry(cache->detached.next,
225 struct backref_node, list);
226 remove_backref_node(cache, node);
229 while (!list_empty(&cache->leaves)) {
230 node = list_entry(cache->leaves.next,
231 struct backref_node, lower);
232 remove_backref_node(cache, node);
235 cache->last_trans = 0;
237 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
238 BUG_ON(!list_empty(&cache->pending[i]));
239 BUG_ON(!list_empty(&cache->changed));
240 BUG_ON(!list_empty(&cache->detached));
241 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
242 BUG_ON(cache->nr_nodes);
243 BUG_ON(cache->nr_edges);
246 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
248 struct backref_node *node;
250 node = kzalloc(sizeof(*node), GFP_NOFS);
252 INIT_LIST_HEAD(&node->list);
253 INIT_LIST_HEAD(&node->upper);
254 INIT_LIST_HEAD(&node->lower);
255 RB_CLEAR_NODE(&node->rb_node);
261 static void free_backref_node(struct backref_cache *cache,
262 struct backref_node *node)
270 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
272 struct backref_edge *edge;
274 edge = kzalloc(sizeof(*edge), GFP_NOFS);
280 static void free_backref_edge(struct backref_cache *cache,
281 struct backref_edge *edge)
289 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
290 struct rb_node *node)
292 struct rb_node **p = &root->rb_node;
293 struct rb_node *parent = NULL;
294 struct tree_entry *entry;
298 entry = rb_entry(parent, struct tree_entry, rb_node);
300 if (bytenr < entry->bytenr)
302 else if (bytenr > entry->bytenr)
308 rb_link_node(node, parent, p);
309 rb_insert_color(node, root);
313 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
315 struct rb_node *n = root->rb_node;
316 struct tree_entry *entry;
319 entry = rb_entry(n, struct tree_entry, rb_node);
321 if (bytenr < entry->bytenr)
323 else if (bytenr > entry->bytenr)
331 static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
334 struct btrfs_fs_info *fs_info = NULL;
335 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
338 fs_info = bnode->root->fs_info;
339 btrfs_panic(fs_info, errno, "Inconsistency in backref cache "
340 "found at offset %llu", bytenr);
344 * walk up backref nodes until reach node presents tree root
346 static struct backref_node *walk_up_backref(struct backref_node *node,
347 struct backref_edge *edges[],
350 struct backref_edge *edge;
353 while (!list_empty(&node->upper)) {
354 edge = list_entry(node->upper.next,
355 struct backref_edge, list[LOWER]);
357 node = edge->node[UPPER];
359 BUG_ON(node->detached);
365 * walk down backref nodes to find start of next reference path
367 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
370 struct backref_edge *edge;
371 struct backref_node *lower;
375 edge = edges[idx - 1];
376 lower = edge->node[LOWER];
377 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
381 edge = list_entry(edge->list[LOWER].next,
382 struct backref_edge, list[LOWER]);
383 edges[idx - 1] = edge;
385 return edge->node[UPPER];
391 static void unlock_node_buffer(struct backref_node *node)
394 btrfs_tree_unlock(node->eb);
399 static void drop_node_buffer(struct backref_node *node)
402 unlock_node_buffer(node);
403 free_extent_buffer(node->eb);
408 static void drop_backref_node(struct backref_cache *tree,
409 struct backref_node *node)
411 BUG_ON(!list_empty(&node->upper));
413 drop_node_buffer(node);
414 list_del(&node->list);
415 list_del(&node->lower);
416 if (!RB_EMPTY_NODE(&node->rb_node))
417 rb_erase(&node->rb_node, &tree->rb_root);
418 free_backref_node(tree, node);
422 * remove a backref node from the backref cache
424 static void remove_backref_node(struct backref_cache *cache,
425 struct backref_node *node)
427 struct backref_node *upper;
428 struct backref_edge *edge;
433 BUG_ON(!node->lowest && !node->detached);
434 while (!list_empty(&node->upper)) {
435 edge = list_entry(node->upper.next, struct backref_edge,
437 upper = edge->node[UPPER];
438 list_del(&edge->list[LOWER]);
439 list_del(&edge->list[UPPER]);
440 free_backref_edge(cache, edge);
442 if (RB_EMPTY_NODE(&upper->rb_node)) {
443 BUG_ON(!list_empty(&node->upper));
444 drop_backref_node(cache, node);
450 * add the node to leaf node list if no other
451 * child block cached.
453 if (list_empty(&upper->lower)) {
454 list_add_tail(&upper->lower, &cache->leaves);
459 drop_backref_node(cache, node);
462 static void update_backref_node(struct backref_cache *cache,
463 struct backref_node *node, u64 bytenr)
465 struct rb_node *rb_node;
466 rb_erase(&node->rb_node, &cache->rb_root);
467 node->bytenr = bytenr;
468 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
470 backref_tree_panic(rb_node, -EEXIST, bytenr);
474 * update backref cache after a transaction commit
476 static int update_backref_cache(struct btrfs_trans_handle *trans,
477 struct backref_cache *cache)
479 struct backref_node *node;
482 if (cache->last_trans == 0) {
483 cache->last_trans = trans->transid;
487 if (cache->last_trans == trans->transid)
491 * detached nodes are used to avoid unnecessary backref
492 * lookup. transaction commit changes the extent tree.
493 * so the detached nodes are no longer useful.
495 while (!list_empty(&cache->detached)) {
496 node = list_entry(cache->detached.next,
497 struct backref_node, list);
498 remove_backref_node(cache, node);
501 while (!list_empty(&cache->changed)) {
502 node = list_entry(cache->changed.next,
503 struct backref_node, list);
504 list_del_init(&node->list);
505 BUG_ON(node->pending);
506 update_backref_node(cache, node, node->new_bytenr);
510 * some nodes can be left in the pending list if there were
511 * errors during processing the pending nodes.
513 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
514 list_for_each_entry(node, &cache->pending[level], list) {
515 BUG_ON(!node->pending);
516 if (node->bytenr == node->new_bytenr)
518 update_backref_node(cache, node, node->new_bytenr);
522 cache->last_trans = 0;
527 static int should_ignore_root(struct btrfs_root *root)
529 struct btrfs_root *reloc_root;
531 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
534 reloc_root = root->reloc_root;
538 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
539 root->fs_info->running_transaction->transid - 1)
542 * if there is reloc tree and it was created in previous
543 * transaction backref lookup can find the reloc tree,
544 * so backref node for the fs tree root is useless for
550 * find reloc tree by address of tree root
552 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
555 struct rb_node *rb_node;
556 struct mapping_node *node;
557 struct btrfs_root *root = NULL;
559 spin_lock(&rc->reloc_root_tree.lock);
560 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
562 node = rb_entry(rb_node, struct mapping_node, rb_node);
563 root = (struct btrfs_root *)node->data;
565 spin_unlock(&rc->reloc_root_tree.lock);
569 static int is_cowonly_root(u64 root_objectid)
571 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
572 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
573 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
574 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
575 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
576 root_objectid == BTRFS_CSUM_TREE_OBJECTID ||
577 root_objectid == BTRFS_UUID_TREE_OBJECTID ||
578 root_objectid == BTRFS_QUOTA_TREE_OBJECTID)
583 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
586 struct btrfs_key key;
588 key.objectid = root_objectid;
589 key.type = BTRFS_ROOT_ITEM_KEY;
590 if (is_cowonly_root(root_objectid))
593 key.offset = (u64)-1;
595 return btrfs_get_fs_root(fs_info, &key, false);
598 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
599 static noinline_for_stack
600 struct btrfs_root *find_tree_root(struct reloc_control *rc,
601 struct extent_buffer *leaf,
602 struct btrfs_extent_ref_v0 *ref0)
604 struct btrfs_root *root;
605 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
606 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
608 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
610 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
611 BUG_ON(IS_ERR(root));
613 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
614 generation != btrfs_root_generation(&root->root_item))
621 static noinline_for_stack
622 int find_inline_backref(struct extent_buffer *leaf, int slot,
623 unsigned long *ptr, unsigned long *end)
625 struct btrfs_key key;
626 struct btrfs_extent_item *ei;
627 struct btrfs_tree_block_info *bi;
630 btrfs_item_key_to_cpu(leaf, &key, slot);
632 item_size = btrfs_item_size_nr(leaf, slot);
633 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
634 if (item_size < sizeof(*ei)) {
635 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
639 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
640 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
641 BTRFS_EXTENT_FLAG_TREE_BLOCK));
643 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
644 item_size <= sizeof(*ei) + sizeof(*bi)) {
645 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
648 if (key.type == BTRFS_METADATA_ITEM_KEY &&
649 item_size <= sizeof(*ei)) {
650 WARN_ON(item_size < sizeof(*ei));
654 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
655 bi = (struct btrfs_tree_block_info *)(ei + 1);
656 *ptr = (unsigned long)(bi + 1);
658 *ptr = (unsigned long)(ei + 1);
660 *end = (unsigned long)ei + item_size;
665 * build backref tree for a given tree block. root of the backref tree
666 * corresponds the tree block, leaves of the backref tree correspond
667 * roots of b-trees that reference the tree block.
669 * the basic idea of this function is check backrefs of a given block
670 * to find upper level blocks that refernece the block, and then check
671 * bakcrefs of these upper level blocks recursively. the recursion stop
672 * when tree root is reached or backrefs for the block is cached.
674 * NOTE: if we find backrefs for a block are cached, we know backrefs
675 * for all upper level blocks that directly/indirectly reference the
676 * block are also cached.
678 static noinline_for_stack
679 struct backref_node *build_backref_tree(struct reloc_control *rc,
680 struct btrfs_key *node_key,
681 int level, u64 bytenr)
683 struct backref_cache *cache = &rc->backref_cache;
684 struct btrfs_path *path1;
685 struct btrfs_path *path2;
686 struct extent_buffer *eb;
687 struct btrfs_root *root;
688 struct backref_node *cur;
689 struct backref_node *upper;
690 struct backref_node *lower;
691 struct backref_node *node = NULL;
692 struct backref_node *exist = NULL;
693 struct backref_edge *edge;
694 struct rb_node *rb_node;
695 struct btrfs_key key;
703 bool need_check = true;
705 path1 = btrfs_alloc_path();
706 path2 = btrfs_alloc_path();
707 if (!path1 || !path2) {
714 node = alloc_backref_node(cache);
720 node->bytenr = bytenr;
727 key.objectid = cur->bytenr;
728 key.type = BTRFS_METADATA_ITEM_KEY;
729 key.offset = (u64)-1;
731 path1->search_commit_root = 1;
732 path1->skip_locking = 1;
733 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
740 ASSERT(path1->slots[0]);
744 WARN_ON(cur->checked);
745 if (!list_empty(&cur->upper)) {
747 * the backref was added previously when processing
748 * backref of type BTRFS_TREE_BLOCK_REF_KEY
750 ASSERT(list_is_singular(&cur->upper));
751 edge = list_entry(cur->upper.next, struct backref_edge,
753 ASSERT(list_empty(&edge->list[UPPER]));
754 exist = edge->node[UPPER];
756 * add the upper level block to pending list if we need
760 list_add_tail(&edge->list[UPPER], &list);
767 eb = path1->nodes[0];
770 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
771 ret = btrfs_next_leaf(rc->extent_root, path1);
778 eb = path1->nodes[0];
781 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
782 if (key.objectid != cur->bytenr) {
787 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
788 key.type == BTRFS_METADATA_ITEM_KEY) {
789 ret = find_inline_backref(eb, path1->slots[0],
797 /* update key for inline back ref */
798 struct btrfs_extent_inline_ref *iref;
799 iref = (struct btrfs_extent_inline_ref *)ptr;
800 key.type = btrfs_extent_inline_ref_type(eb, iref);
801 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
802 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
803 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
807 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
808 exist->owner == key.offset) ||
809 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
810 exist->bytenr == key.offset))) {
815 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
816 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
817 key.type == BTRFS_EXTENT_REF_V0_KEY) {
818 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
819 struct btrfs_extent_ref_v0 *ref0;
820 ref0 = btrfs_item_ptr(eb, path1->slots[0],
821 struct btrfs_extent_ref_v0);
822 if (key.objectid == key.offset) {
823 root = find_tree_root(rc, eb, ref0);
824 if (root && !should_ignore_root(root))
827 list_add(&cur->list, &useless);
830 if (is_cowonly_root(btrfs_ref_root_v0(eb,
835 ASSERT(key.type != BTRFS_EXTENT_REF_V0_KEY);
836 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
838 if (key.objectid == key.offset) {
840 * only root blocks of reloc trees use
841 * backref of this type.
843 root = find_reloc_root(rc, cur->bytenr);
849 edge = alloc_backref_edge(cache);
854 rb_node = tree_search(&cache->rb_root, key.offset);
856 upper = alloc_backref_node(cache);
858 free_backref_edge(cache, edge);
862 upper->bytenr = key.offset;
863 upper->level = cur->level + 1;
865 * backrefs for the upper level block isn't
866 * cached, add the block to pending list
868 list_add_tail(&edge->list[UPPER], &list);
870 upper = rb_entry(rb_node, struct backref_node,
872 ASSERT(upper->checked);
873 INIT_LIST_HEAD(&edge->list[UPPER]);
875 list_add_tail(&edge->list[LOWER], &cur->upper);
876 edge->node[LOWER] = cur;
877 edge->node[UPPER] = upper;
880 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
884 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
885 root = read_fs_root(rc->extent_root->fs_info, key.offset);
891 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
894 if (btrfs_root_level(&root->root_item) == cur->level) {
896 ASSERT(btrfs_root_bytenr(&root->root_item) ==
898 if (should_ignore_root(root))
899 list_add(&cur->list, &useless);
905 level = cur->level + 1;
908 * searching the tree to find upper level blocks
909 * reference the block.
911 path2->search_commit_root = 1;
912 path2->skip_locking = 1;
913 path2->lowest_level = level;
914 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
915 path2->lowest_level = 0;
920 if (ret > 0 && path2->slots[level] > 0)
921 path2->slots[level]--;
923 eb = path2->nodes[level];
924 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
929 for (; level < BTRFS_MAX_LEVEL; level++) {
930 if (!path2->nodes[level]) {
931 ASSERT(btrfs_root_bytenr(&root->root_item) ==
933 if (should_ignore_root(root))
934 list_add(&lower->list, &useless);
940 edge = alloc_backref_edge(cache);
946 eb = path2->nodes[level];
947 rb_node = tree_search(&cache->rb_root, eb->start);
949 upper = alloc_backref_node(cache);
951 free_backref_edge(cache, edge);
955 upper->bytenr = eb->start;
956 upper->owner = btrfs_header_owner(eb);
957 upper->level = lower->level + 1;
958 if (!test_bit(BTRFS_ROOT_REF_COWS,
963 * if we know the block isn't shared
964 * we can void checking its backrefs.
966 if (btrfs_block_can_be_shared(root, eb))
972 * add the block to pending list if we
973 * need check its backrefs, we only do this once
974 * while walking up a tree as we will catch
975 * anything else later on.
977 if (!upper->checked && need_check) {
979 list_add_tail(&edge->list[UPPER],
982 INIT_LIST_HEAD(&edge->list[UPPER]);
984 upper = rb_entry(rb_node, struct backref_node,
986 ASSERT(upper->checked);
987 INIT_LIST_HEAD(&edge->list[UPPER]);
989 upper->owner = btrfs_header_owner(eb);
991 list_add_tail(&edge->list[LOWER], &lower->upper);
992 edge->node[LOWER] = lower;
993 edge->node[UPPER] = upper;
1000 btrfs_release_path(path2);
1003 ptr += btrfs_extent_inline_ref_size(key.type);
1013 btrfs_release_path(path1);
1018 /* the pending list isn't empty, take the first block to process */
1019 if (!list_empty(&list)) {
1020 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1021 list_del_init(&edge->list[UPPER]);
1022 cur = edge->node[UPPER];
1027 * everything goes well, connect backref nodes and insert backref nodes
1030 ASSERT(node->checked);
1031 cowonly = node->cowonly;
1033 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1036 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1037 list_add_tail(&node->lower, &cache->leaves);
1040 list_for_each_entry(edge, &node->upper, list[LOWER])
1041 list_add_tail(&edge->list[UPPER], &list);
1043 while (!list_empty(&list)) {
1044 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1045 list_del_init(&edge->list[UPPER]);
1046 upper = edge->node[UPPER];
1047 if (upper->detached) {
1048 list_del(&edge->list[LOWER]);
1049 lower = edge->node[LOWER];
1050 free_backref_edge(cache, edge);
1051 if (list_empty(&lower->upper))
1052 list_add(&lower->list, &useless);
1056 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1057 if (upper->lowest) {
1058 list_del_init(&upper->lower);
1062 list_add_tail(&edge->list[UPPER], &upper->lower);
1066 if (!upper->checked) {
1068 * Still want to blow up for developers since this is a
1075 if (cowonly != upper->cowonly) {
1082 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1085 backref_tree_panic(rb_node, -EEXIST,
1089 list_add_tail(&edge->list[UPPER], &upper->lower);
1091 list_for_each_entry(edge, &upper->upper, list[LOWER])
1092 list_add_tail(&edge->list[UPPER], &list);
1095 * process useless backref nodes. backref nodes for tree leaves
1096 * are deleted from the cache. backref nodes for upper level
1097 * tree blocks are left in the cache to avoid unnecessary backref
1100 while (!list_empty(&useless)) {
1101 upper = list_entry(useless.next, struct backref_node, list);
1102 list_del_init(&upper->list);
1103 ASSERT(list_empty(&upper->upper));
1106 if (upper->lowest) {
1107 list_del_init(&upper->lower);
1110 while (!list_empty(&upper->lower)) {
1111 edge = list_entry(upper->lower.next,
1112 struct backref_edge, list[UPPER]);
1113 list_del(&edge->list[UPPER]);
1114 list_del(&edge->list[LOWER]);
1115 lower = edge->node[LOWER];
1116 free_backref_edge(cache, edge);
1118 if (list_empty(&lower->upper))
1119 list_add(&lower->list, &useless);
1121 __mark_block_processed(rc, upper);
1122 if (upper->level > 0) {
1123 list_add(&upper->list, &cache->detached);
1124 upper->detached = 1;
1126 rb_erase(&upper->rb_node, &cache->rb_root);
1127 free_backref_node(cache, upper);
1131 btrfs_free_path(path1);
1132 btrfs_free_path(path2);
1134 while (!list_empty(&useless)) {
1135 lower = list_entry(useless.next,
1136 struct backref_node, list);
1137 list_del_init(&lower->list);
1139 while (!list_empty(&list)) {
1140 edge = list_first_entry(&list, struct backref_edge,
1142 list_del(&edge->list[UPPER]);
1143 list_del(&edge->list[LOWER]);
1144 lower = edge->node[LOWER];
1145 upper = edge->node[UPPER];
1146 free_backref_edge(cache, edge);
1149 * Lower is no longer linked to any upper backref nodes
1150 * and isn't in the cache, we can free it ourselves.
1152 if (list_empty(&lower->upper) &&
1153 RB_EMPTY_NODE(&lower->rb_node))
1154 list_add(&lower->list, &useless);
1156 if (!RB_EMPTY_NODE(&upper->rb_node))
1159 /* Add this guy's upper edges to the list to proces */
1160 list_for_each_entry(edge, &upper->upper, list[LOWER])
1161 list_add_tail(&edge->list[UPPER], &list);
1162 if (list_empty(&upper->upper))
1163 list_add(&upper->list, &useless);
1166 while (!list_empty(&useless)) {
1167 lower = list_entry(useless.next,
1168 struct backref_node, list);
1169 list_del_init(&lower->list);
1170 free_backref_node(cache, lower);
1172 return ERR_PTR(err);
1174 ASSERT(!node || !node->detached);
1179 * helper to add backref node for the newly created snapshot.
1180 * the backref node is created by cloning backref node that
1181 * corresponds to root of source tree
1183 static int clone_backref_node(struct btrfs_trans_handle *trans,
1184 struct reloc_control *rc,
1185 struct btrfs_root *src,
1186 struct btrfs_root *dest)
1188 struct btrfs_root *reloc_root = src->reloc_root;
1189 struct backref_cache *cache = &rc->backref_cache;
1190 struct backref_node *node = NULL;
1191 struct backref_node *new_node;
1192 struct backref_edge *edge;
1193 struct backref_edge *new_edge;
1194 struct rb_node *rb_node;
1196 if (cache->last_trans > 0)
1197 update_backref_cache(trans, cache);
1199 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1201 node = rb_entry(rb_node, struct backref_node, rb_node);
1205 BUG_ON(node->new_bytenr != reloc_root->node->start);
1209 rb_node = tree_search(&cache->rb_root,
1210 reloc_root->commit_root->start);
1212 node = rb_entry(rb_node, struct backref_node,
1214 BUG_ON(node->detached);
1221 new_node = alloc_backref_node(cache);
1225 new_node->bytenr = dest->node->start;
1226 new_node->level = node->level;
1227 new_node->lowest = node->lowest;
1228 new_node->checked = 1;
1229 new_node->root = dest;
1231 if (!node->lowest) {
1232 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1233 new_edge = alloc_backref_edge(cache);
1237 new_edge->node[UPPER] = new_node;
1238 new_edge->node[LOWER] = edge->node[LOWER];
1239 list_add_tail(&new_edge->list[UPPER],
1243 list_add_tail(&new_node->lower, &cache->leaves);
1246 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1247 &new_node->rb_node);
1249 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1251 if (!new_node->lowest) {
1252 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1253 list_add_tail(&new_edge->list[LOWER],
1254 &new_edge->node[LOWER]->upper);
1259 while (!list_empty(&new_node->lower)) {
1260 new_edge = list_entry(new_node->lower.next,
1261 struct backref_edge, list[UPPER]);
1262 list_del(&new_edge->list[UPPER]);
1263 free_backref_edge(cache, new_edge);
1265 free_backref_node(cache, new_node);
1270 * helper to add 'address of tree root -> reloc tree' mapping
1272 static int __must_check __add_reloc_root(struct btrfs_root *root)
1274 struct rb_node *rb_node;
1275 struct mapping_node *node;
1276 struct reloc_control *rc = root->fs_info->reloc_ctl;
1278 node = kmalloc(sizeof(*node), GFP_NOFS);
1282 node->bytenr = root->node->start;
1285 spin_lock(&rc->reloc_root_tree.lock);
1286 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1287 node->bytenr, &node->rb_node);
1288 spin_unlock(&rc->reloc_root_tree.lock);
1290 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1291 "for start=%llu while inserting into relocation "
1292 "tree", node->bytenr);
1297 list_add_tail(&root->root_list, &rc->reloc_roots);
1302 * helper to delete the 'address of tree root -> reloc tree'
1305 static void __del_reloc_root(struct btrfs_root *root)
1307 struct rb_node *rb_node;
1308 struct mapping_node *node = NULL;
1309 struct reloc_control *rc = root->fs_info->reloc_ctl;
1311 spin_lock(&rc->reloc_root_tree.lock);
1312 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1315 node = rb_entry(rb_node, struct mapping_node, rb_node);
1316 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1318 spin_unlock(&rc->reloc_root_tree.lock);
1322 BUG_ON((struct btrfs_root *)node->data != root);
1324 spin_lock(&root->fs_info->trans_lock);
1325 list_del_init(&root->root_list);
1326 spin_unlock(&root->fs_info->trans_lock);
1331 * helper to update the 'address of tree root -> reloc tree'
1334 static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr)
1336 struct rb_node *rb_node;
1337 struct mapping_node *node = NULL;
1338 struct reloc_control *rc = root->fs_info->reloc_ctl;
1340 spin_lock(&rc->reloc_root_tree.lock);
1341 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1344 node = rb_entry(rb_node, struct mapping_node, rb_node);
1345 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1347 spin_unlock(&rc->reloc_root_tree.lock);
1351 BUG_ON((struct btrfs_root *)node->data != root);
1353 spin_lock(&rc->reloc_root_tree.lock);
1354 node->bytenr = new_bytenr;
1355 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1356 node->bytenr, &node->rb_node);
1357 spin_unlock(&rc->reloc_root_tree.lock);
1359 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1363 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1364 struct btrfs_root *root, u64 objectid)
1366 struct btrfs_root *reloc_root;
1367 struct extent_buffer *eb;
1368 struct btrfs_root_item *root_item;
1369 struct btrfs_key root_key;
1373 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1376 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1377 root_key.type = BTRFS_ROOT_ITEM_KEY;
1378 root_key.offset = objectid;
1380 if (root->root_key.objectid == objectid) {
1381 /* called by btrfs_init_reloc_root */
1382 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1383 BTRFS_TREE_RELOC_OBJECTID);
1386 last_snap = btrfs_root_last_snapshot(&root->root_item);
1387 btrfs_set_root_last_snapshot(&root->root_item,
1388 trans->transid - 1);
1391 * called by btrfs_reloc_post_snapshot_hook.
1392 * the source tree is a reloc tree, all tree blocks
1393 * modified after it was created have RELOC flag
1394 * set in their headers. so it's OK to not update
1395 * the 'last_snapshot'.
1397 ret = btrfs_copy_root(trans, root, root->node, &eb,
1398 BTRFS_TREE_RELOC_OBJECTID);
1402 memcpy(root_item, &root->root_item, sizeof(*root_item));
1403 btrfs_set_root_bytenr(root_item, eb->start);
1404 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1405 btrfs_set_root_generation(root_item, trans->transid);
1407 if (root->root_key.objectid == objectid) {
1408 btrfs_set_root_refs(root_item, 0);
1409 memset(&root_item->drop_progress, 0,
1410 sizeof(struct btrfs_disk_key));
1411 root_item->drop_level = 0;
1413 * abuse rtransid, it is safe because it is impossible to
1414 * receive data into a relocation tree.
1416 btrfs_set_root_rtransid(root_item, last_snap);
1417 btrfs_set_root_otransid(root_item, trans->transid);
1420 btrfs_tree_unlock(eb);
1421 free_extent_buffer(eb);
1423 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1424 &root_key, root_item);
1428 reloc_root = btrfs_read_fs_root(root->fs_info->tree_root, &root_key);
1429 BUG_ON(IS_ERR(reloc_root));
1430 reloc_root->last_trans = trans->transid;
1435 * create reloc tree for a given fs tree. reloc tree is just a
1436 * snapshot of the fs tree with special root objectid.
1438 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1439 struct btrfs_root *root)
1441 struct btrfs_root *reloc_root;
1442 struct reloc_control *rc = root->fs_info->reloc_ctl;
1443 struct btrfs_block_rsv *rsv;
1447 if (root->reloc_root) {
1448 reloc_root = root->reloc_root;
1449 reloc_root->last_trans = trans->transid;
1453 if (!rc || !rc->create_reloc_tree ||
1454 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1457 if (!trans->reloc_reserved) {
1458 rsv = trans->block_rsv;
1459 trans->block_rsv = rc->block_rsv;
1462 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1464 trans->block_rsv = rsv;
1466 ret = __add_reloc_root(reloc_root);
1468 root->reloc_root = reloc_root;
1473 * update root item of reloc tree
1475 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1476 struct btrfs_root *root)
1478 struct btrfs_root *reloc_root;
1479 struct btrfs_root_item *root_item;
1482 if (!root->reloc_root)
1485 reloc_root = root->reloc_root;
1486 root_item = &reloc_root->root_item;
1488 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1489 btrfs_root_refs(root_item) == 0) {
1490 root->reloc_root = NULL;
1491 __del_reloc_root(reloc_root);
1494 if (reloc_root->commit_root != reloc_root->node) {
1495 btrfs_set_root_node(root_item, reloc_root->node);
1496 free_extent_buffer(reloc_root->commit_root);
1497 reloc_root->commit_root = btrfs_root_node(reloc_root);
1500 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1501 &reloc_root->root_key, root_item);
1509 * helper to find first cached inode with inode number >= objectid
1512 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1514 struct rb_node *node;
1515 struct rb_node *prev;
1516 struct btrfs_inode *entry;
1517 struct inode *inode;
1519 spin_lock(&root->inode_lock);
1521 node = root->inode_tree.rb_node;
1525 entry = rb_entry(node, struct btrfs_inode, rb_node);
1527 if (objectid < btrfs_ino(&entry->vfs_inode))
1528 node = node->rb_left;
1529 else if (objectid > btrfs_ino(&entry->vfs_inode))
1530 node = node->rb_right;
1536 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1537 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1541 prev = rb_next(prev);
1545 entry = rb_entry(node, struct btrfs_inode, rb_node);
1546 inode = igrab(&entry->vfs_inode);
1548 spin_unlock(&root->inode_lock);
1552 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1553 if (cond_resched_lock(&root->inode_lock))
1556 node = rb_next(node);
1558 spin_unlock(&root->inode_lock);
1562 static int in_block_group(u64 bytenr,
1563 struct btrfs_block_group_cache *block_group)
1565 if (bytenr >= block_group->key.objectid &&
1566 bytenr < block_group->key.objectid + block_group->key.offset)
1572 * get new location of data
1574 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1575 u64 bytenr, u64 num_bytes)
1577 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1578 struct btrfs_path *path;
1579 struct btrfs_file_extent_item *fi;
1580 struct extent_buffer *leaf;
1583 path = btrfs_alloc_path();
1587 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1588 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1597 leaf = path->nodes[0];
1598 fi = btrfs_item_ptr(leaf, path->slots[0],
1599 struct btrfs_file_extent_item);
1601 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1602 btrfs_file_extent_compression(leaf, fi) ||
1603 btrfs_file_extent_encryption(leaf, fi) ||
1604 btrfs_file_extent_other_encoding(leaf, fi));
1606 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1611 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1614 btrfs_free_path(path);
1619 * update file extent items in the tree leaf to point to
1620 * the new locations.
1622 static noinline_for_stack
1623 int replace_file_extents(struct btrfs_trans_handle *trans,
1624 struct reloc_control *rc,
1625 struct btrfs_root *root,
1626 struct extent_buffer *leaf)
1628 struct btrfs_key key;
1629 struct btrfs_file_extent_item *fi;
1630 struct inode *inode = NULL;
1642 if (rc->stage != UPDATE_DATA_PTRS)
1645 /* reloc trees always use full backref */
1646 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1647 parent = leaf->start;
1651 nritems = btrfs_header_nritems(leaf);
1652 for (i = 0; i < nritems; i++) {
1654 btrfs_item_key_to_cpu(leaf, &key, i);
1655 if (key.type != BTRFS_EXTENT_DATA_KEY)
1657 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1658 if (btrfs_file_extent_type(leaf, fi) ==
1659 BTRFS_FILE_EXTENT_INLINE)
1661 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1662 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1665 if (!in_block_group(bytenr, rc->block_group))
1669 * if we are modifying block in fs tree, wait for readpage
1670 * to complete and drop the extent cache
1672 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1674 inode = find_next_inode(root, key.objectid);
1676 } else if (inode && btrfs_ino(inode) < key.objectid) {
1677 btrfs_add_delayed_iput(inode);
1678 inode = find_next_inode(root, key.objectid);
1680 if (inode && btrfs_ino(inode) == key.objectid) {
1682 btrfs_file_extent_num_bytes(leaf, fi);
1683 WARN_ON(!IS_ALIGNED(key.offset,
1685 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1687 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1692 btrfs_drop_extent_cache(inode, key.offset, end,
1694 unlock_extent(&BTRFS_I(inode)->io_tree,
1699 ret = get_new_location(rc->data_inode, &new_bytenr,
1703 * Don't have to abort since we've not changed anything
1704 * in the file extent yet.
1709 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1712 key.offset -= btrfs_file_extent_offset(leaf, fi);
1713 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1715 btrfs_header_owner(leaf),
1716 key.objectid, key.offset, 1);
1718 btrfs_abort_transaction(trans, root, ret);
1722 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1723 parent, btrfs_header_owner(leaf),
1724 key.objectid, key.offset, 1);
1726 btrfs_abort_transaction(trans, root, ret);
1731 btrfs_mark_buffer_dirty(leaf);
1733 btrfs_add_delayed_iput(inode);
1737 static noinline_for_stack
1738 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1739 struct btrfs_path *path, int level)
1741 struct btrfs_disk_key key1;
1742 struct btrfs_disk_key key2;
1743 btrfs_node_key(eb, &key1, slot);
1744 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1745 return memcmp(&key1, &key2, sizeof(key1));
1749 * try to replace tree blocks in fs tree with the new blocks
1750 * in reloc tree. tree blocks haven't been modified since the
1751 * reloc tree was create can be replaced.
1753 * if a block was replaced, level of the block + 1 is returned.
1754 * if no block got replaced, 0 is returned. if there are other
1755 * errors, a negative error number is returned.
1757 static noinline_for_stack
1758 int replace_path(struct btrfs_trans_handle *trans,
1759 struct btrfs_root *dest, struct btrfs_root *src,
1760 struct btrfs_path *path, struct btrfs_key *next_key,
1761 int lowest_level, int max_level)
1763 struct extent_buffer *eb;
1764 struct extent_buffer *parent;
1765 struct btrfs_key key;
1777 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1778 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1780 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1782 slot = path->slots[lowest_level];
1783 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1785 eb = btrfs_lock_root_node(dest);
1786 btrfs_set_lock_blocking(eb);
1787 level = btrfs_header_level(eb);
1789 if (level < lowest_level) {
1790 btrfs_tree_unlock(eb);
1791 free_extent_buffer(eb);
1796 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1799 btrfs_set_lock_blocking(eb);
1802 next_key->objectid = (u64)-1;
1803 next_key->type = (u8)-1;
1804 next_key->offset = (u64)-1;
1809 level = btrfs_header_level(parent);
1810 BUG_ON(level < lowest_level);
1812 ret = btrfs_bin_search(parent, &key, level, &slot);
1813 if (ret && slot > 0)
1816 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1817 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1819 old_bytenr = btrfs_node_blockptr(parent, slot);
1820 blocksize = dest->nodesize;
1821 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1823 if (level <= max_level) {
1824 eb = path->nodes[level];
1825 new_bytenr = btrfs_node_blockptr(eb,
1826 path->slots[level]);
1827 new_ptr_gen = btrfs_node_ptr_generation(eb,
1828 path->slots[level]);
1834 if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
1839 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1840 memcmp_node_keys(parent, slot, path, level)) {
1841 if (level <= lowest_level) {
1846 eb = read_tree_block(dest, old_bytenr, blocksize,
1848 if (!eb || !extent_buffer_uptodate(eb)) {
1849 ret = (!eb) ? -ENOMEM : -EIO;
1850 free_extent_buffer(eb);
1853 btrfs_tree_lock(eb);
1855 ret = btrfs_cow_block(trans, dest, eb, parent,
1859 btrfs_set_lock_blocking(eb);
1861 btrfs_tree_unlock(parent);
1862 free_extent_buffer(parent);
1869 btrfs_tree_unlock(parent);
1870 free_extent_buffer(parent);
1875 btrfs_node_key_to_cpu(path->nodes[level], &key,
1876 path->slots[level]);
1877 btrfs_release_path(path);
1879 path->lowest_level = level;
1880 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1881 path->lowest_level = 0;
1885 * swap blocks in fs tree and reloc tree.
1887 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1888 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1889 btrfs_mark_buffer_dirty(parent);
1891 btrfs_set_node_blockptr(path->nodes[level],
1892 path->slots[level], old_bytenr);
1893 btrfs_set_node_ptr_generation(path->nodes[level],
1894 path->slots[level], old_ptr_gen);
1895 btrfs_mark_buffer_dirty(path->nodes[level]);
1897 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1898 path->nodes[level]->start,
1899 src->root_key.objectid, level - 1, 0,
1902 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1903 0, dest->root_key.objectid, level - 1,
1907 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1908 path->nodes[level]->start,
1909 src->root_key.objectid, level - 1, 0,
1913 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1914 0, dest->root_key.objectid, level - 1,
1918 btrfs_unlock_up_safe(path, 0);
1923 btrfs_tree_unlock(parent);
1924 free_extent_buffer(parent);
1929 * helper to find next relocated block in reloc tree
1931 static noinline_for_stack
1932 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1935 struct extent_buffer *eb;
1940 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1942 for (i = 0; i < *level; i++) {
1943 free_extent_buffer(path->nodes[i]);
1944 path->nodes[i] = NULL;
1947 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1948 eb = path->nodes[i];
1949 nritems = btrfs_header_nritems(eb);
1950 while (path->slots[i] + 1 < nritems) {
1952 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1959 free_extent_buffer(path->nodes[i]);
1960 path->nodes[i] = NULL;
1966 * walk down reloc tree to find relocated block of lowest level
1968 static noinline_for_stack
1969 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1972 struct extent_buffer *eb = NULL;
1980 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1982 for (i = *level; i > 0; i--) {
1983 eb = path->nodes[i];
1984 nritems = btrfs_header_nritems(eb);
1985 while (path->slots[i] < nritems) {
1986 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1987 if (ptr_gen > last_snapshot)
1991 if (path->slots[i] >= nritems) {
2002 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
2003 blocksize = root->nodesize;
2004 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
2005 if (!eb || !extent_buffer_uptodate(eb)) {
2006 free_extent_buffer(eb);
2009 BUG_ON(btrfs_header_level(eb) != i - 1);
2010 path->nodes[i - 1] = eb;
2011 path->slots[i - 1] = 0;
2017 * invalidate extent cache for file extents whose key in range of
2018 * [min_key, max_key)
2020 static int invalidate_extent_cache(struct btrfs_root *root,
2021 struct btrfs_key *min_key,
2022 struct btrfs_key *max_key)
2024 struct inode *inode = NULL;
2029 objectid = min_key->objectid;
2034 if (objectid > max_key->objectid)
2037 inode = find_next_inode(root, objectid);
2040 ino = btrfs_ino(inode);
2042 if (ino > max_key->objectid) {
2048 if (!S_ISREG(inode->i_mode))
2051 if (unlikely(min_key->objectid == ino)) {
2052 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
2054 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
2057 start = min_key->offset;
2058 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
2064 if (unlikely(max_key->objectid == ino)) {
2065 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2067 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2070 if (max_key->offset == 0)
2072 end = max_key->offset;
2073 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2080 /* the lock_extent waits for readpage to complete */
2081 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2082 btrfs_drop_extent_cache(inode, start, end, 1);
2083 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2088 static int find_next_key(struct btrfs_path *path, int level,
2089 struct btrfs_key *key)
2092 while (level < BTRFS_MAX_LEVEL) {
2093 if (!path->nodes[level])
2095 if (path->slots[level] + 1 <
2096 btrfs_header_nritems(path->nodes[level])) {
2097 btrfs_node_key_to_cpu(path->nodes[level], key,
2098 path->slots[level] + 1);
2107 * merge the relocated tree blocks in reloc tree with corresponding
2110 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2111 struct btrfs_root *root)
2113 LIST_HEAD(inode_list);
2114 struct btrfs_key key;
2115 struct btrfs_key next_key;
2116 struct btrfs_trans_handle *trans = NULL;
2117 struct btrfs_root *reloc_root;
2118 struct btrfs_root_item *root_item;
2119 struct btrfs_path *path;
2120 struct extent_buffer *leaf;
2128 path = btrfs_alloc_path();
2133 reloc_root = root->reloc_root;
2134 root_item = &reloc_root->root_item;
2136 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2137 level = btrfs_root_level(root_item);
2138 extent_buffer_get(reloc_root->node);
2139 path->nodes[level] = reloc_root->node;
2140 path->slots[level] = 0;
2142 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2144 level = root_item->drop_level;
2146 path->lowest_level = level;
2147 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2148 path->lowest_level = 0;
2150 btrfs_free_path(path);
2154 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2155 path->slots[level]);
2156 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2158 btrfs_unlock_up_safe(path, 0);
2161 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2162 memset(&next_key, 0, sizeof(next_key));
2165 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2166 BTRFS_RESERVE_FLUSH_ALL);
2171 trans = btrfs_start_transaction(root, 0);
2172 if (IS_ERR(trans)) {
2173 err = PTR_ERR(trans);
2177 trans->block_rsv = rc->block_rsv;
2182 ret = walk_down_reloc_tree(reloc_root, path, &level);
2190 if (!find_next_key(path, level, &key) &&
2191 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2194 ret = replace_path(trans, root, reloc_root, path,
2195 &next_key, level, max_level);
2204 btrfs_node_key_to_cpu(path->nodes[level], &key,
2205 path->slots[level]);
2209 ret = walk_up_reloc_tree(reloc_root, path, &level);
2215 * save the merging progress in the drop_progress.
2216 * this is OK since root refs == 1 in this case.
2218 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2219 path->slots[level]);
2220 root_item->drop_level = level;
2222 btrfs_end_transaction_throttle(trans, root);
2225 btrfs_btree_balance_dirty(root);
2227 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2228 invalidate_extent_cache(root, &key, &next_key);
2232 * handle the case only one block in the fs tree need to be
2233 * relocated and the block is tree root.
2235 leaf = btrfs_lock_root_node(root);
2236 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2237 btrfs_tree_unlock(leaf);
2238 free_extent_buffer(leaf);
2242 btrfs_free_path(path);
2245 memset(&root_item->drop_progress, 0,
2246 sizeof(root_item->drop_progress));
2247 root_item->drop_level = 0;
2248 btrfs_set_root_refs(root_item, 0);
2249 btrfs_update_reloc_root(trans, root);
2253 btrfs_end_transaction_throttle(trans, root);
2255 btrfs_btree_balance_dirty(root);
2257 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2258 invalidate_extent_cache(root, &key, &next_key);
2263 static noinline_for_stack
2264 int prepare_to_merge(struct reloc_control *rc, int err)
2266 struct btrfs_root *root = rc->extent_root;
2267 struct btrfs_root *reloc_root;
2268 struct btrfs_trans_handle *trans;
2269 LIST_HEAD(reloc_roots);
2273 mutex_lock(&root->fs_info->reloc_mutex);
2274 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2275 rc->merging_rsv_size += rc->nodes_relocated * 2;
2276 mutex_unlock(&root->fs_info->reloc_mutex);
2280 num_bytes = rc->merging_rsv_size;
2281 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2282 BTRFS_RESERVE_FLUSH_ALL);
2287 trans = btrfs_join_transaction(rc->extent_root);
2288 if (IS_ERR(trans)) {
2290 btrfs_block_rsv_release(rc->extent_root,
2291 rc->block_rsv, num_bytes);
2292 return PTR_ERR(trans);
2296 if (num_bytes != rc->merging_rsv_size) {
2297 btrfs_end_transaction(trans, rc->extent_root);
2298 btrfs_block_rsv_release(rc->extent_root,
2299 rc->block_rsv, num_bytes);
2304 rc->merge_reloc_tree = 1;
2306 while (!list_empty(&rc->reloc_roots)) {
2307 reloc_root = list_entry(rc->reloc_roots.next,
2308 struct btrfs_root, root_list);
2309 list_del_init(&reloc_root->root_list);
2311 root = read_fs_root(reloc_root->fs_info,
2312 reloc_root->root_key.offset);
2313 BUG_ON(IS_ERR(root));
2314 BUG_ON(root->reloc_root != reloc_root);
2317 * set reference count to 1, so btrfs_recover_relocation
2318 * knows it should resumes merging
2321 btrfs_set_root_refs(&reloc_root->root_item, 1);
2322 btrfs_update_reloc_root(trans, root);
2324 list_add(&reloc_root->root_list, &reloc_roots);
2327 list_splice(&reloc_roots, &rc->reloc_roots);
2330 btrfs_commit_transaction(trans, rc->extent_root);
2332 btrfs_end_transaction(trans, rc->extent_root);
2336 static noinline_for_stack
2337 void free_reloc_roots(struct list_head *list)
2339 struct btrfs_root *reloc_root;
2341 while (!list_empty(list)) {
2342 reloc_root = list_entry(list->next, struct btrfs_root,
2344 __del_reloc_root(reloc_root);
2348 static noinline_for_stack
2349 int merge_reloc_roots(struct reloc_control *rc)
2351 struct btrfs_root *root;
2352 struct btrfs_root *reloc_root;
2356 LIST_HEAD(reloc_roots);
2360 root = rc->extent_root;
2363 * this serializes us with btrfs_record_root_in_transaction,
2364 * we have to make sure nobody is in the middle of
2365 * adding their roots to the list while we are
2368 mutex_lock(&root->fs_info->reloc_mutex);
2369 list_splice_init(&rc->reloc_roots, &reloc_roots);
2370 mutex_unlock(&root->fs_info->reloc_mutex);
2372 while (!list_empty(&reloc_roots)) {
2374 reloc_root = list_entry(reloc_roots.next,
2375 struct btrfs_root, root_list);
2377 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2378 root = read_fs_root(reloc_root->fs_info,
2379 reloc_root->root_key.offset);
2380 BUG_ON(IS_ERR(root));
2381 BUG_ON(root->reloc_root != reloc_root);
2383 ret = merge_reloc_root(rc, root);
2385 if (list_empty(&reloc_root->root_list))
2386 list_add_tail(&reloc_root->root_list,
2391 list_del_init(&reloc_root->root_list);
2395 * we keep the old last snapshod transid in rtranid when we
2396 * created the relocation tree.
2398 last_snap = btrfs_root_rtransid(&reloc_root->root_item);
2399 otransid = btrfs_root_otransid(&reloc_root->root_item);
2400 objectid = reloc_root->root_key.offset;
2402 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2404 if (list_empty(&reloc_root->root_list))
2405 list_add_tail(&reloc_root->root_list,
2417 btrfs_std_error(root->fs_info, ret);
2418 if (!list_empty(&reloc_roots))
2419 free_reloc_roots(&reloc_roots);
2421 /* new reloc root may be added */
2422 mutex_lock(&root->fs_info->reloc_mutex);
2423 list_splice_init(&rc->reloc_roots, &reloc_roots);
2424 mutex_unlock(&root->fs_info->reloc_mutex);
2425 if (!list_empty(&reloc_roots))
2426 free_reloc_roots(&reloc_roots);
2429 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2433 static void free_block_list(struct rb_root *blocks)
2435 struct tree_block *block;
2436 struct rb_node *rb_node;
2437 while ((rb_node = rb_first(blocks))) {
2438 block = rb_entry(rb_node, struct tree_block, rb_node);
2439 rb_erase(rb_node, blocks);
2444 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2445 struct btrfs_root *reloc_root)
2447 struct btrfs_root *root;
2449 if (reloc_root->last_trans == trans->transid)
2452 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2453 BUG_ON(IS_ERR(root));
2454 BUG_ON(root->reloc_root != reloc_root);
2456 return btrfs_record_root_in_trans(trans, root);
2459 static noinline_for_stack
2460 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2461 struct reloc_control *rc,
2462 struct backref_node *node,
2463 struct backref_edge *edges[])
2465 struct backref_node *next;
2466 struct btrfs_root *root;
2472 next = walk_up_backref(next, edges, &index);
2475 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS, &root->state));
2477 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2478 record_reloc_root_in_trans(trans, root);
2482 btrfs_record_root_in_trans(trans, root);
2483 root = root->reloc_root;
2485 if (next->new_bytenr != root->node->start) {
2486 BUG_ON(next->new_bytenr);
2487 BUG_ON(!list_empty(&next->list));
2488 next->new_bytenr = root->node->start;
2490 list_add_tail(&next->list,
2491 &rc->backref_cache.changed);
2492 __mark_block_processed(rc, next);
2498 next = walk_down_backref(edges, &index);
2499 if (!next || next->level <= node->level)
2506 /* setup backref node path for btrfs_reloc_cow_block */
2508 rc->backref_cache.path[next->level] = next;
2511 next = edges[index]->node[UPPER];
2517 * select a tree root for relocation. return NULL if the block
2518 * is reference counted. we should use do_relocation() in this
2519 * case. return a tree root pointer if the block isn't reference
2520 * counted. return -ENOENT if the block is root of reloc tree.
2522 static noinline_for_stack
2523 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2524 struct backref_node *node)
2526 struct backref_node *next;
2527 struct btrfs_root *root;
2528 struct btrfs_root *fs_root = NULL;
2529 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2535 next = walk_up_backref(next, edges, &index);
2539 /* no other choice for non-references counted tree */
2540 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
2543 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2549 next = walk_down_backref(edges, &index);
2550 if (!next || next->level <= node->level)
2555 return ERR_PTR(-ENOENT);
2559 static noinline_for_stack
2560 u64 calcu_metadata_size(struct reloc_control *rc,
2561 struct backref_node *node, int reserve)
2563 struct backref_node *next = node;
2564 struct backref_edge *edge;
2565 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2569 BUG_ON(reserve && node->processed);
2574 if (next->processed && (reserve || next != node))
2577 num_bytes += rc->extent_root->nodesize;
2579 if (list_empty(&next->upper))
2582 edge = list_entry(next->upper.next,
2583 struct backref_edge, list[LOWER]);
2584 edges[index++] = edge;
2585 next = edge->node[UPPER];
2587 next = walk_down_backref(edges, &index);
2592 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2593 struct reloc_control *rc,
2594 struct backref_node *node)
2596 struct btrfs_root *root = rc->extent_root;
2601 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2603 trans->block_rsv = rc->block_rsv;
2604 rc->reserved_bytes += num_bytes;
2605 ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes,
2606 BTRFS_RESERVE_FLUSH_ALL);
2608 if (ret == -EAGAIN) {
2609 tmp = rc->extent_root->nodesize *
2610 RELOCATION_RESERVED_NODES;
2611 while (tmp <= rc->reserved_bytes)
2614 * only one thread can access block_rsv at this point,
2615 * so we don't need hold lock to protect block_rsv.
2616 * we expand more reservation size here to allow enough
2617 * space for relocation and we will return eailer in
2620 rc->block_rsv->size = tmp + rc->extent_root->nodesize *
2621 RELOCATION_RESERVED_NODES;
2630 * relocate a block tree, and then update pointers in upper level
2631 * blocks that reference the block to point to the new location.
2633 * if called by link_to_upper, the block has already been relocated.
2634 * in that case this function just updates pointers.
2636 static int do_relocation(struct btrfs_trans_handle *trans,
2637 struct reloc_control *rc,
2638 struct backref_node *node,
2639 struct btrfs_key *key,
2640 struct btrfs_path *path, int lowest)
2642 struct backref_node *upper;
2643 struct backref_edge *edge;
2644 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2645 struct btrfs_root *root;
2646 struct extent_buffer *eb;
2654 BUG_ON(lowest && node->eb);
2656 path->lowest_level = node->level + 1;
2657 rc->backref_cache.path[node->level] = node;
2658 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2661 upper = edge->node[UPPER];
2662 root = select_reloc_root(trans, rc, upper, edges);
2665 if (upper->eb && !upper->locked) {
2667 ret = btrfs_bin_search(upper->eb, key,
2668 upper->level, &slot);
2670 bytenr = btrfs_node_blockptr(upper->eb, slot);
2671 if (node->eb->start == bytenr)
2674 drop_node_buffer(upper);
2678 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2686 upper->eb = path->nodes[upper->level];
2687 path->nodes[upper->level] = NULL;
2689 BUG_ON(upper->eb != path->nodes[upper->level]);
2693 path->locks[upper->level] = 0;
2695 slot = path->slots[upper->level];
2696 btrfs_release_path(path);
2698 ret = btrfs_bin_search(upper->eb, key, upper->level,
2703 bytenr = btrfs_node_blockptr(upper->eb, slot);
2705 BUG_ON(bytenr != node->bytenr);
2707 if (node->eb->start == bytenr)
2711 blocksize = root->nodesize;
2712 generation = btrfs_node_ptr_generation(upper->eb, slot);
2713 eb = read_tree_block(root, bytenr, blocksize, generation);
2714 if (!eb || !extent_buffer_uptodate(eb)) {
2715 free_extent_buffer(eb);
2719 btrfs_tree_lock(eb);
2720 btrfs_set_lock_blocking(eb);
2723 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2725 btrfs_tree_unlock(eb);
2726 free_extent_buffer(eb);
2731 BUG_ON(node->eb != eb);
2733 btrfs_set_node_blockptr(upper->eb, slot,
2735 btrfs_set_node_ptr_generation(upper->eb, slot,
2737 btrfs_mark_buffer_dirty(upper->eb);
2739 ret = btrfs_inc_extent_ref(trans, root,
2740 node->eb->start, blocksize,
2742 btrfs_header_owner(upper->eb),
2746 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2750 if (!upper->pending)
2751 drop_node_buffer(upper);
2753 unlock_node_buffer(upper);
2758 if (!err && node->pending) {
2759 drop_node_buffer(node);
2760 list_move_tail(&node->list, &rc->backref_cache.changed);
2764 path->lowest_level = 0;
2765 BUG_ON(err == -ENOSPC);
2769 static int link_to_upper(struct btrfs_trans_handle *trans,
2770 struct reloc_control *rc,
2771 struct backref_node *node,
2772 struct btrfs_path *path)
2774 struct btrfs_key key;
2776 btrfs_node_key_to_cpu(node->eb, &key, 0);
2777 return do_relocation(trans, rc, node, &key, path, 0);
2780 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2781 struct reloc_control *rc,
2782 struct btrfs_path *path, int err)
2785 struct backref_cache *cache = &rc->backref_cache;
2786 struct backref_node *node;
2790 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2791 while (!list_empty(&cache->pending[level])) {
2792 node = list_entry(cache->pending[level].next,
2793 struct backref_node, list);
2794 list_move_tail(&node->list, &list);
2795 BUG_ON(!node->pending);
2798 ret = link_to_upper(trans, rc, node, path);
2803 list_splice_init(&list, &cache->pending[level]);
2808 static void mark_block_processed(struct reloc_control *rc,
2809 u64 bytenr, u32 blocksize)
2811 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2812 EXTENT_DIRTY, GFP_NOFS);
2815 static void __mark_block_processed(struct reloc_control *rc,
2816 struct backref_node *node)
2819 if (node->level == 0 ||
2820 in_block_group(node->bytenr, rc->block_group)) {
2821 blocksize = rc->extent_root->nodesize;
2822 mark_block_processed(rc, node->bytenr, blocksize);
2824 node->processed = 1;
2828 * mark a block and all blocks directly/indirectly reference the block
2831 static void update_processed_blocks(struct reloc_control *rc,
2832 struct backref_node *node)
2834 struct backref_node *next = node;
2835 struct backref_edge *edge;
2836 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2842 if (next->processed)
2845 __mark_block_processed(rc, next);
2847 if (list_empty(&next->upper))
2850 edge = list_entry(next->upper.next,
2851 struct backref_edge, list[LOWER]);
2852 edges[index++] = edge;
2853 next = edge->node[UPPER];
2855 next = walk_down_backref(edges, &index);
2859 static int tree_block_processed(u64 bytenr, u32 blocksize,
2860 struct reloc_control *rc)
2862 if (test_range_bit(&rc->processed_blocks, bytenr,
2863 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2868 static int get_tree_block_key(struct reloc_control *rc,
2869 struct tree_block *block)
2871 struct extent_buffer *eb;
2873 BUG_ON(block->key_ready);
2874 eb = read_tree_block(rc->extent_root, block->bytenr,
2875 block->key.objectid, block->key.offset);
2876 if (!eb || !extent_buffer_uptodate(eb)) {
2877 free_extent_buffer(eb);
2880 WARN_ON(btrfs_header_level(eb) != block->level);
2881 if (block->level == 0)
2882 btrfs_item_key_to_cpu(eb, &block->key, 0);
2884 btrfs_node_key_to_cpu(eb, &block->key, 0);
2885 free_extent_buffer(eb);
2886 block->key_ready = 1;
2890 static int reada_tree_block(struct reloc_control *rc,
2891 struct tree_block *block)
2893 BUG_ON(block->key_ready);
2894 if (block->key.type == BTRFS_METADATA_ITEM_KEY)
2895 readahead_tree_block(rc->extent_root, block->bytenr,
2896 block->key.objectid,
2897 rc->extent_root->nodesize);
2899 readahead_tree_block(rc->extent_root, block->bytenr,
2900 block->key.objectid, block->key.offset);
2905 * helper function to relocate a tree block
2907 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2908 struct reloc_control *rc,
2909 struct backref_node *node,
2910 struct btrfs_key *key,
2911 struct btrfs_path *path)
2913 struct btrfs_root *root;
2919 BUG_ON(node->processed);
2920 root = select_one_root(trans, node);
2921 if (root == ERR_PTR(-ENOENT)) {
2922 update_processed_blocks(rc, node);
2926 if (!root || test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2927 ret = reserve_metadata_space(trans, rc, node);
2933 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2934 BUG_ON(node->new_bytenr);
2935 BUG_ON(!list_empty(&node->list));
2936 btrfs_record_root_in_trans(trans, root);
2937 root = root->reloc_root;
2938 node->new_bytenr = root->node->start;
2940 list_add_tail(&node->list, &rc->backref_cache.changed);
2942 path->lowest_level = node->level;
2943 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2944 btrfs_release_path(path);
2949 update_processed_blocks(rc, node);
2951 ret = do_relocation(trans, rc, node, key, path, 1);
2954 if (ret || node->level == 0 || node->cowonly)
2955 remove_backref_node(&rc->backref_cache, node);
2960 * relocate a list of blocks
2962 static noinline_for_stack
2963 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2964 struct reloc_control *rc, struct rb_root *blocks)
2966 struct backref_node *node;
2967 struct btrfs_path *path;
2968 struct tree_block *block;
2969 struct rb_node *rb_node;
2973 path = btrfs_alloc_path();
2976 goto out_free_blocks;
2979 rb_node = rb_first(blocks);
2981 block = rb_entry(rb_node, struct tree_block, rb_node);
2982 if (!block->key_ready)
2983 reada_tree_block(rc, block);
2984 rb_node = rb_next(rb_node);
2987 rb_node = rb_first(blocks);
2989 block = rb_entry(rb_node, struct tree_block, rb_node);
2990 if (!block->key_ready) {
2991 err = get_tree_block_key(rc, block);
2995 rb_node = rb_next(rb_node);
2998 rb_node = rb_first(blocks);
3000 block = rb_entry(rb_node, struct tree_block, rb_node);
3002 node = build_backref_tree(rc, &block->key,
3003 block->level, block->bytenr);
3005 err = PTR_ERR(node);
3009 ret = relocate_tree_block(trans, rc, node, &block->key,
3012 if (ret != -EAGAIN || rb_node == rb_first(blocks))
3016 rb_node = rb_next(rb_node);
3019 err = finish_pending_nodes(trans, rc, path, err);
3022 btrfs_free_path(path);
3024 free_block_list(blocks);
3028 static noinline_for_stack
3029 int prealloc_file_extent_cluster(struct inode *inode,
3030 struct file_extent_cluster *cluster)
3035 u64 offset = BTRFS_I(inode)->index_cnt;
3040 BUG_ON(cluster->start != cluster->boundary[0]);
3041 mutex_lock(&inode->i_mutex);
3043 ret = btrfs_check_data_free_space(inode, cluster->end +
3044 1 - cluster->start);
3048 while (nr < cluster->nr) {
3049 start = cluster->boundary[nr] - offset;
3050 if (nr + 1 < cluster->nr)
3051 end = cluster->boundary[nr + 1] - 1 - offset;
3053 end = cluster->end - offset;
3055 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3056 num_bytes = end + 1 - start;
3057 ret = btrfs_prealloc_file_range(inode, 0, start,
3058 num_bytes, num_bytes,
3059 end + 1, &alloc_hint);
3060 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3065 btrfs_free_reserved_data_space(inode, cluster->end +
3066 1 - cluster->start);
3068 mutex_unlock(&inode->i_mutex);
3072 static noinline_for_stack
3073 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3076 struct btrfs_root *root = BTRFS_I(inode)->root;
3077 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3078 struct extent_map *em;
3081 em = alloc_extent_map();
3086 em->len = end + 1 - start;
3087 em->block_len = em->len;
3088 em->block_start = block_start;
3089 em->bdev = root->fs_info->fs_devices->latest_bdev;
3090 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3092 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3094 write_lock(&em_tree->lock);
3095 ret = add_extent_mapping(em_tree, em, 0);
3096 write_unlock(&em_tree->lock);
3097 if (ret != -EEXIST) {
3098 free_extent_map(em);
3101 btrfs_drop_extent_cache(inode, start, end, 0);
3103 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3107 static int relocate_file_extent_cluster(struct inode *inode,
3108 struct file_extent_cluster *cluster)
3112 u64 offset = BTRFS_I(inode)->index_cnt;
3113 unsigned long index;
3114 unsigned long last_index;
3116 struct file_ra_state *ra;
3117 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3124 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3128 ret = prealloc_file_extent_cluster(inode, cluster);
3132 file_ra_state_init(ra, inode->i_mapping);
3134 ret = setup_extent_mapping(inode, cluster->start - offset,
3135 cluster->end - offset, cluster->start);
3139 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
3140 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
3141 while (index <= last_index) {
3142 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
3146 page = find_lock_page(inode->i_mapping, index);
3148 page_cache_sync_readahead(inode->i_mapping,
3150 last_index + 1 - index);
3151 page = find_or_create_page(inode->i_mapping, index,
3154 btrfs_delalloc_release_metadata(inode,
3161 if (PageReadahead(page)) {
3162 page_cache_async_readahead(inode->i_mapping,
3163 ra, NULL, page, index,
3164 last_index + 1 - index);
3167 if (!PageUptodate(page)) {
3168 btrfs_readpage(NULL, page);
3170 if (!PageUptodate(page)) {
3172 page_cache_release(page);
3173 btrfs_delalloc_release_metadata(inode,
3180 page_start = page_offset(page);
3181 page_end = page_start + PAGE_CACHE_SIZE - 1;
3183 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3185 set_page_extent_mapped(page);
3187 if (nr < cluster->nr &&
3188 page_start + offset == cluster->boundary[nr]) {
3189 set_extent_bits(&BTRFS_I(inode)->io_tree,
3190 page_start, page_end,
3191 EXTENT_BOUNDARY, GFP_NOFS);
3195 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3196 set_page_dirty(page);
3198 unlock_extent(&BTRFS_I(inode)->io_tree,
3199 page_start, page_end);
3201 page_cache_release(page);
3204 balance_dirty_pages_ratelimited(inode->i_mapping);
3205 btrfs_throttle(BTRFS_I(inode)->root);
3207 WARN_ON(nr != cluster->nr);
3213 static noinline_for_stack
3214 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3215 struct file_extent_cluster *cluster)
3219 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3220 ret = relocate_file_extent_cluster(inode, cluster);
3227 cluster->start = extent_key->objectid;
3229 BUG_ON(cluster->nr >= MAX_EXTENTS);
3230 cluster->end = extent_key->objectid + extent_key->offset - 1;
3231 cluster->boundary[cluster->nr] = extent_key->objectid;
3234 if (cluster->nr >= MAX_EXTENTS) {
3235 ret = relocate_file_extent_cluster(inode, cluster);
3243 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3244 static int get_ref_objectid_v0(struct reloc_control *rc,
3245 struct btrfs_path *path,
3246 struct btrfs_key *extent_key,
3247 u64 *ref_objectid, int *path_change)
3249 struct btrfs_key key;
3250 struct extent_buffer *leaf;
3251 struct btrfs_extent_ref_v0 *ref0;
3255 leaf = path->nodes[0];
3256 slot = path->slots[0];
3258 if (slot >= btrfs_header_nritems(leaf)) {
3259 ret = btrfs_next_leaf(rc->extent_root, path);
3263 leaf = path->nodes[0];
3264 slot = path->slots[0];
3268 btrfs_item_key_to_cpu(leaf, &key, slot);
3269 if (key.objectid != extent_key->objectid)
3272 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3276 ref0 = btrfs_item_ptr(leaf, slot,
3277 struct btrfs_extent_ref_v0);
3278 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3286 * helper to add a tree block to the list.
3287 * the major work is getting the generation and level of the block
3289 static int add_tree_block(struct reloc_control *rc,
3290 struct btrfs_key *extent_key,
3291 struct btrfs_path *path,
3292 struct rb_root *blocks)
3294 struct extent_buffer *eb;
3295 struct btrfs_extent_item *ei;
3296 struct btrfs_tree_block_info *bi;
3297 struct tree_block *block;
3298 struct rb_node *rb_node;
3303 eb = path->nodes[0];
3304 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3306 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3307 item_size >= sizeof(*ei) + sizeof(*bi)) {
3308 ei = btrfs_item_ptr(eb, path->slots[0],
3309 struct btrfs_extent_item);
3310 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3311 bi = (struct btrfs_tree_block_info *)(ei + 1);
3312 level = btrfs_tree_block_level(eb, bi);
3314 level = (int)extent_key->offset;
3316 generation = btrfs_extent_generation(eb, ei);
3318 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3322 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3323 ret = get_ref_objectid_v0(rc, path, extent_key,
3327 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3328 level = (int)ref_owner;
3329 /* FIXME: get real generation */
3336 btrfs_release_path(path);
3338 BUG_ON(level == -1);
3340 block = kmalloc(sizeof(*block), GFP_NOFS);
3344 block->bytenr = extent_key->objectid;
3345 block->key.objectid = rc->extent_root->nodesize;
3346 block->key.offset = generation;
3347 block->level = level;
3348 block->key_ready = 0;
3350 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3352 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3358 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3360 static int __add_tree_block(struct reloc_control *rc,
3361 u64 bytenr, u32 blocksize,
3362 struct rb_root *blocks)
3364 struct btrfs_path *path;
3365 struct btrfs_key key;
3367 bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
3370 if (tree_block_processed(bytenr, blocksize, rc))
3373 if (tree_search(blocks, bytenr))
3376 path = btrfs_alloc_path();
3380 key.objectid = bytenr;
3382 key.type = BTRFS_METADATA_ITEM_KEY;
3383 key.offset = (u64)-1;
3385 key.type = BTRFS_EXTENT_ITEM_KEY;
3386 key.offset = blocksize;
3389 path->search_commit_root = 1;
3390 path->skip_locking = 1;
3391 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3395 if (ret > 0 && skinny) {
3396 if (path->slots[0]) {
3398 btrfs_item_key_to_cpu(path->nodes[0], &key,
3400 if (key.objectid == bytenr &&
3401 (key.type == BTRFS_METADATA_ITEM_KEY ||
3402 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3403 key.offset == blocksize)))
3409 btrfs_release_path(path);
3415 ret = add_tree_block(rc, &key, path, blocks);
3417 btrfs_free_path(path);
3422 * helper to check if the block use full backrefs for pointers in it
3424 static int block_use_full_backref(struct reloc_control *rc,
3425 struct extent_buffer *eb)
3430 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3431 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3434 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3435 eb->start, btrfs_header_level(eb), 1,
3439 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3446 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3447 struct inode *inode, u64 ino)
3449 struct btrfs_key key;
3450 struct btrfs_root *root = fs_info->tree_root;
3451 struct btrfs_trans_handle *trans;
3458 key.type = BTRFS_INODE_ITEM_KEY;
3461 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3462 if (IS_ERR(inode) || is_bad_inode(inode)) {
3469 ret = btrfs_check_trunc_cache_free_space(root,
3470 &fs_info->global_block_rsv);
3474 trans = btrfs_join_transaction(root);
3475 if (IS_ERR(trans)) {
3476 ret = PTR_ERR(trans);
3480 ret = btrfs_truncate_free_space_cache(root, trans, inode);
3482 btrfs_end_transaction(trans, root);
3483 btrfs_btree_balance_dirty(root);
3490 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3491 * this function scans fs tree to find blocks reference the data extent
3493 static int find_data_references(struct reloc_control *rc,
3494 struct btrfs_key *extent_key,
3495 struct extent_buffer *leaf,
3496 struct btrfs_extent_data_ref *ref,
3497 struct rb_root *blocks)
3499 struct btrfs_path *path;
3500 struct tree_block *block;
3501 struct btrfs_root *root;
3502 struct btrfs_file_extent_item *fi;
3503 struct rb_node *rb_node;
3504 struct btrfs_key key;
3515 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3516 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3517 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3518 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3521 * This is an extent belonging to the free space cache, lets just delete
3522 * it and redo the search.
3524 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3525 ret = delete_block_group_cache(rc->extent_root->fs_info,
3526 NULL, ref_objectid);
3532 path = btrfs_alloc_path();
3537 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3539 err = PTR_ERR(root);
3543 key.objectid = ref_objectid;
3544 key.type = BTRFS_EXTENT_DATA_KEY;
3545 if (ref_offset > ((u64)-1 << 32))
3548 key.offset = ref_offset;
3550 path->search_commit_root = 1;
3551 path->skip_locking = 1;
3552 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3558 leaf = path->nodes[0];
3559 nritems = btrfs_header_nritems(leaf);
3561 * the references in tree blocks that use full backrefs
3562 * are not counted in
3564 if (block_use_full_backref(rc, leaf))
3568 rb_node = tree_search(blocks, leaf->start);
3573 path->slots[0] = nritems;
3576 while (ref_count > 0) {
3577 while (path->slots[0] >= nritems) {
3578 ret = btrfs_next_leaf(root, path);
3583 if (WARN_ON(ret > 0))
3586 leaf = path->nodes[0];
3587 nritems = btrfs_header_nritems(leaf);
3590 if (block_use_full_backref(rc, leaf))
3594 rb_node = tree_search(blocks, leaf->start);
3599 path->slots[0] = nritems;
3603 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3604 if (WARN_ON(key.objectid != ref_objectid ||
3605 key.type != BTRFS_EXTENT_DATA_KEY))
3608 fi = btrfs_item_ptr(leaf, path->slots[0],
3609 struct btrfs_file_extent_item);
3611 if (btrfs_file_extent_type(leaf, fi) ==
3612 BTRFS_FILE_EXTENT_INLINE)
3615 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3616 extent_key->objectid)
3619 key.offset -= btrfs_file_extent_offset(leaf, fi);
3620 if (key.offset != ref_offset)
3628 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3629 block = kmalloc(sizeof(*block), GFP_NOFS);
3634 block->bytenr = leaf->start;
3635 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3637 block->key_ready = 1;
3638 rb_node = tree_insert(blocks, block->bytenr,
3641 backref_tree_panic(rb_node, -EEXIST,
3647 path->slots[0] = nritems;
3653 btrfs_free_path(path);
3658 * helper to find all tree blocks that reference a given data extent
3660 static noinline_for_stack
3661 int add_data_references(struct reloc_control *rc,
3662 struct btrfs_key *extent_key,
3663 struct btrfs_path *path,
3664 struct rb_root *blocks)
3666 struct btrfs_key key;
3667 struct extent_buffer *eb;
3668 struct btrfs_extent_data_ref *dref;
3669 struct btrfs_extent_inline_ref *iref;
3672 u32 blocksize = rc->extent_root->nodesize;
3676 eb = path->nodes[0];
3677 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3678 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3679 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3680 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3684 ptr += sizeof(struct btrfs_extent_item);
3687 iref = (struct btrfs_extent_inline_ref *)ptr;
3688 key.type = btrfs_extent_inline_ref_type(eb, iref);
3689 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3690 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3691 ret = __add_tree_block(rc, key.offset, blocksize,
3693 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3694 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3695 ret = find_data_references(rc, extent_key,
3704 ptr += btrfs_extent_inline_ref_size(key.type);
3710 eb = path->nodes[0];
3711 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3712 ret = btrfs_next_leaf(rc->extent_root, path);
3719 eb = path->nodes[0];
3722 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3723 if (key.objectid != extent_key->objectid)
3726 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3727 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3728 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3730 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3731 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3733 ret = __add_tree_block(rc, key.offset, blocksize,
3735 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3736 dref = btrfs_item_ptr(eb, path->slots[0],
3737 struct btrfs_extent_data_ref);
3738 ret = find_data_references(rc, extent_key,
3750 btrfs_release_path(path);
3752 free_block_list(blocks);
3757 * helper to find next unprocessed extent
3759 static noinline_for_stack
3760 int find_next_extent(struct btrfs_trans_handle *trans,
3761 struct reloc_control *rc, struct btrfs_path *path,
3762 struct btrfs_key *extent_key)
3764 struct btrfs_key key;
3765 struct extent_buffer *leaf;
3766 u64 start, end, last;
3769 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3772 if (rc->search_start >= last) {
3777 key.objectid = rc->search_start;
3778 key.type = BTRFS_EXTENT_ITEM_KEY;
3781 path->search_commit_root = 1;
3782 path->skip_locking = 1;
3783 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3788 leaf = path->nodes[0];
3789 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3790 ret = btrfs_next_leaf(rc->extent_root, path);
3793 leaf = path->nodes[0];
3796 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3797 if (key.objectid >= last) {
3802 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3803 key.type != BTRFS_METADATA_ITEM_KEY) {
3808 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3809 key.objectid + key.offset <= rc->search_start) {
3814 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3815 key.objectid + rc->extent_root->nodesize <=
3821 ret = find_first_extent_bit(&rc->processed_blocks,
3822 key.objectid, &start, &end,
3823 EXTENT_DIRTY, NULL);
3825 if (ret == 0 && start <= key.objectid) {
3826 btrfs_release_path(path);
3827 rc->search_start = end + 1;
3829 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3830 rc->search_start = key.objectid + key.offset;
3832 rc->search_start = key.objectid +
3833 rc->extent_root->nodesize;
3834 memcpy(extent_key, &key, sizeof(key));
3838 btrfs_release_path(path);
3842 static void set_reloc_control(struct reloc_control *rc)
3844 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3846 mutex_lock(&fs_info->reloc_mutex);
3847 fs_info->reloc_ctl = rc;
3848 mutex_unlock(&fs_info->reloc_mutex);
3851 static void unset_reloc_control(struct reloc_control *rc)
3853 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3855 mutex_lock(&fs_info->reloc_mutex);
3856 fs_info->reloc_ctl = NULL;
3857 mutex_unlock(&fs_info->reloc_mutex);
3860 static int check_extent_flags(u64 flags)
3862 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3863 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3865 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3866 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3868 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3869 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3874 static noinline_for_stack
3875 int prepare_to_relocate(struct reloc_control *rc)
3877 struct btrfs_trans_handle *trans;
3879 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3880 BTRFS_BLOCK_RSV_TEMP);
3884 memset(&rc->cluster, 0, sizeof(rc->cluster));
3885 rc->search_start = rc->block_group->key.objectid;
3886 rc->extents_found = 0;
3887 rc->nodes_relocated = 0;
3888 rc->merging_rsv_size = 0;
3889 rc->reserved_bytes = 0;
3890 rc->block_rsv->size = rc->extent_root->nodesize *
3891 RELOCATION_RESERVED_NODES;
3893 rc->create_reloc_tree = 1;
3894 set_reloc_control(rc);
3896 trans = btrfs_join_transaction(rc->extent_root);
3897 if (IS_ERR(trans)) {
3898 unset_reloc_control(rc);
3900 * extent tree is not a ref_cow tree and has no reloc_root to
3901 * cleanup. And callers are responsible to free the above
3904 return PTR_ERR(trans);
3906 btrfs_commit_transaction(trans, rc->extent_root);
3910 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3912 struct rb_root blocks = RB_ROOT;
3913 struct btrfs_key key;
3914 struct btrfs_trans_handle *trans = NULL;
3915 struct btrfs_path *path;
3916 struct btrfs_extent_item *ei;
3923 path = btrfs_alloc_path();
3928 ret = prepare_to_relocate(rc);
3935 rc->reserved_bytes = 0;
3936 ret = btrfs_block_rsv_refill(rc->extent_root,
3937 rc->block_rsv, rc->block_rsv->size,
3938 BTRFS_RESERVE_FLUSH_ALL);
3944 trans = btrfs_start_transaction(rc->extent_root, 0);
3945 if (IS_ERR(trans)) {
3946 err = PTR_ERR(trans);
3951 if (update_backref_cache(trans, &rc->backref_cache)) {
3952 btrfs_end_transaction(trans, rc->extent_root);
3956 ret = find_next_extent(trans, rc, path, &key);
3962 rc->extents_found++;
3964 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3965 struct btrfs_extent_item);
3966 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3967 if (item_size >= sizeof(*ei)) {
3968 flags = btrfs_extent_flags(path->nodes[0], ei);
3969 ret = check_extent_flags(flags);
3973 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3975 int path_change = 0;
3978 sizeof(struct btrfs_extent_item_v0));
3979 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3981 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3982 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3984 flags = BTRFS_EXTENT_FLAG_DATA;
3987 btrfs_release_path(path);
3989 path->search_commit_root = 1;
3990 path->skip_locking = 1;
3991 ret = btrfs_search_slot(NULL, rc->extent_root,
4004 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
4005 ret = add_tree_block(rc, &key, path, &blocks);
4006 } else if (rc->stage == UPDATE_DATA_PTRS &&
4007 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4008 ret = add_data_references(rc, &key, path, &blocks);
4010 btrfs_release_path(path);
4018 if (!RB_EMPTY_ROOT(&blocks)) {
4019 ret = relocate_tree_blocks(trans, rc, &blocks);
4022 * if we fail to relocate tree blocks, force to update
4023 * backref cache when committing transaction.
4025 rc->backref_cache.last_trans = trans->transid - 1;
4027 if (ret != -EAGAIN) {
4031 rc->extents_found--;
4032 rc->search_start = key.objectid;
4036 btrfs_end_transaction_throttle(trans, rc->extent_root);
4037 btrfs_btree_balance_dirty(rc->extent_root);
4040 if (rc->stage == MOVE_DATA_EXTENTS &&
4041 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4042 rc->found_file_extent = 1;
4043 ret = relocate_data_extent(rc->data_inode,
4044 &key, &rc->cluster);
4051 if (trans && progress && err == -ENOSPC) {
4052 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
4053 rc->block_group->flags);
4061 btrfs_release_path(path);
4062 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
4066 btrfs_end_transaction_throttle(trans, rc->extent_root);
4067 btrfs_btree_balance_dirty(rc->extent_root);
4071 ret = relocate_file_extent_cluster(rc->data_inode,
4077 rc->create_reloc_tree = 0;
4078 set_reloc_control(rc);
4080 backref_cache_cleanup(&rc->backref_cache);
4081 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4083 err = prepare_to_merge(rc, err);
4085 merge_reloc_roots(rc);
4087 rc->merge_reloc_tree = 0;
4088 unset_reloc_control(rc);
4089 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4091 /* get rid of pinned extents */
4092 trans = btrfs_join_transaction(rc->extent_root);
4094 err = PTR_ERR(trans);
4096 btrfs_commit_transaction(trans, rc->extent_root);
4098 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4099 btrfs_free_path(path);
4103 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4104 struct btrfs_root *root, u64 objectid)
4106 struct btrfs_path *path;
4107 struct btrfs_inode_item *item;
4108 struct extent_buffer *leaf;
4111 path = btrfs_alloc_path();
4115 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4119 leaf = path->nodes[0];
4120 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4121 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4122 btrfs_set_inode_generation(leaf, item, 1);
4123 btrfs_set_inode_size(leaf, item, 0);
4124 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4125 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4126 BTRFS_INODE_PREALLOC);
4127 btrfs_mark_buffer_dirty(leaf);
4129 btrfs_free_path(path);
4134 * helper to create inode for data relocation.
4135 * the inode is in data relocation tree and its link count is 0
4137 static noinline_for_stack
4138 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4139 struct btrfs_block_group_cache *group)
4141 struct inode *inode = NULL;
4142 struct btrfs_trans_handle *trans;
4143 struct btrfs_root *root;
4144 struct btrfs_key key;
4145 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4148 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4150 return ERR_CAST(root);
4152 trans = btrfs_start_transaction(root, 6);
4154 return ERR_CAST(trans);
4156 err = btrfs_find_free_objectid(root, &objectid);
4160 err = __insert_orphan_inode(trans, root, objectid);
4163 key.objectid = objectid;
4164 key.type = BTRFS_INODE_ITEM_KEY;
4166 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4167 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4168 BTRFS_I(inode)->index_cnt = group->key.objectid;
4170 err = btrfs_orphan_add(trans, inode);
4172 btrfs_end_transaction(trans, root);
4173 btrfs_btree_balance_dirty(root);
4177 inode = ERR_PTR(err);
4182 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4184 struct reloc_control *rc;
4186 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4190 INIT_LIST_HEAD(&rc->reloc_roots);
4191 backref_cache_init(&rc->backref_cache);
4192 mapping_tree_init(&rc->reloc_root_tree);
4193 extent_io_tree_init(&rc->processed_blocks,
4194 fs_info->btree_inode->i_mapping);
4199 * function to relocate all extents in a block group.
4201 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4203 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4204 struct reloc_control *rc;
4205 struct inode *inode;
4206 struct btrfs_path *path;
4211 rc = alloc_reloc_control(fs_info);
4215 rc->extent_root = extent_root;
4217 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4218 BUG_ON(!rc->block_group);
4220 if (!rc->block_group->ro) {
4221 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
4229 path = btrfs_alloc_path();
4235 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4237 btrfs_free_path(path);
4240 ret = delete_block_group_cache(fs_info, inode, 0);
4242 ret = PTR_ERR(inode);
4244 if (ret && ret != -ENOENT) {
4249 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4250 if (IS_ERR(rc->data_inode)) {
4251 err = PTR_ERR(rc->data_inode);
4252 rc->data_inode = NULL;
4256 btrfs_info(extent_root->fs_info, "relocating block group %llu flags %llu",
4257 rc->block_group->key.objectid, rc->block_group->flags);
4259 ret = btrfs_start_delalloc_roots(fs_info, 0, -1);
4264 btrfs_wait_ordered_roots(fs_info, -1);
4267 mutex_lock(&fs_info->cleaner_mutex);
4268 ret = relocate_block_group(rc);
4269 mutex_unlock(&fs_info->cleaner_mutex);
4275 if (rc->extents_found == 0)
4278 btrfs_info(extent_root->fs_info, "found %llu extents",
4281 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4282 ret = btrfs_wait_ordered_range(rc->data_inode, 0,
4288 invalidate_mapping_pages(rc->data_inode->i_mapping,
4290 rc->stage = UPDATE_DATA_PTRS;
4294 WARN_ON(rc->block_group->pinned > 0);
4295 WARN_ON(rc->block_group->reserved > 0);
4296 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4299 btrfs_set_block_group_rw(extent_root, rc->block_group);
4300 iput(rc->data_inode);
4301 btrfs_put_block_group(rc->block_group);
4306 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4308 struct btrfs_trans_handle *trans;
4311 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4313 return PTR_ERR(trans);
4315 memset(&root->root_item.drop_progress, 0,
4316 sizeof(root->root_item.drop_progress));
4317 root->root_item.drop_level = 0;
4318 btrfs_set_root_refs(&root->root_item, 0);
4319 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4320 &root->root_key, &root->root_item);
4322 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4329 * recover relocation interrupted by system crash.
4331 * this function resumes merging reloc trees with corresponding fs trees.
4332 * this is important for keeping the sharing of tree blocks
4334 int btrfs_recover_relocation(struct btrfs_root *root)
4336 LIST_HEAD(reloc_roots);
4337 struct btrfs_key key;
4338 struct btrfs_root *fs_root;
4339 struct btrfs_root *reloc_root;
4340 struct btrfs_path *path;
4341 struct extent_buffer *leaf;
4342 struct reloc_control *rc = NULL;
4343 struct btrfs_trans_handle *trans;
4347 path = btrfs_alloc_path();
4352 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4353 key.type = BTRFS_ROOT_ITEM_KEY;
4354 key.offset = (u64)-1;
4357 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4364 if (path->slots[0] == 0)
4368 leaf = path->nodes[0];
4369 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4370 btrfs_release_path(path);
4372 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4373 key.type != BTRFS_ROOT_ITEM_KEY)
4376 reloc_root = btrfs_read_fs_root(root, &key);
4377 if (IS_ERR(reloc_root)) {
4378 err = PTR_ERR(reloc_root);
4382 list_add(&reloc_root->root_list, &reloc_roots);
4384 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4385 fs_root = read_fs_root(root->fs_info,
4386 reloc_root->root_key.offset);
4387 if (IS_ERR(fs_root)) {
4388 ret = PTR_ERR(fs_root);
4389 if (ret != -ENOENT) {
4393 ret = mark_garbage_root(reloc_root);
4401 if (key.offset == 0)
4406 btrfs_release_path(path);
4408 if (list_empty(&reloc_roots))
4411 rc = alloc_reloc_control(root->fs_info);
4417 rc->extent_root = root->fs_info->extent_root;
4419 set_reloc_control(rc);
4421 trans = btrfs_join_transaction(rc->extent_root);
4422 if (IS_ERR(trans)) {
4423 unset_reloc_control(rc);
4424 err = PTR_ERR(trans);
4428 rc->merge_reloc_tree = 1;
4430 while (!list_empty(&reloc_roots)) {
4431 reloc_root = list_entry(reloc_roots.next,
4432 struct btrfs_root, root_list);
4433 list_del(&reloc_root->root_list);
4435 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4436 list_add_tail(&reloc_root->root_list,
4441 fs_root = read_fs_root(root->fs_info,
4442 reloc_root->root_key.offset);
4443 if (IS_ERR(fs_root)) {
4444 err = PTR_ERR(fs_root);
4448 err = __add_reloc_root(reloc_root);
4449 BUG_ON(err < 0); /* -ENOMEM or logic error */
4450 fs_root->reloc_root = reloc_root;
4453 err = btrfs_commit_transaction(trans, rc->extent_root);
4457 merge_reloc_roots(rc);
4459 unset_reloc_control(rc);
4461 trans = btrfs_join_transaction(rc->extent_root);
4463 err = PTR_ERR(trans);
4465 err = btrfs_commit_transaction(trans, rc->extent_root);
4469 if (!list_empty(&reloc_roots))
4470 free_reloc_roots(&reloc_roots);
4472 btrfs_free_path(path);
4475 /* cleanup orphan inode in data relocation tree */
4476 fs_root = read_fs_root(root->fs_info,
4477 BTRFS_DATA_RELOC_TREE_OBJECTID);
4478 if (IS_ERR(fs_root))
4479 err = PTR_ERR(fs_root);
4481 err = btrfs_orphan_cleanup(fs_root);
4487 * helper to add ordered checksum for data relocation.
4489 * cloning checksum properly handles the nodatasum extents.
4490 * it also saves CPU time to re-calculate the checksum.
4492 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4494 struct btrfs_ordered_sum *sums;
4495 struct btrfs_ordered_extent *ordered;
4496 struct btrfs_root *root = BTRFS_I(inode)->root;
4502 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4503 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4505 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4506 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4507 disk_bytenr + len - 1, &list, 0);
4511 while (!list_empty(&list)) {
4512 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4513 list_del_init(&sums->list);
4516 * We need to offset the new_bytenr based on where the csum is.
4517 * We need to do this because we will read in entire prealloc
4518 * extents but we may have written to say the middle of the
4519 * prealloc extent, so we need to make sure the csum goes with
4520 * the right disk offset.
4522 * We can do this because the data reloc inode refers strictly
4523 * to the on disk bytes, so we don't have to worry about
4524 * disk_len vs real len like with real inodes since it's all
4527 new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
4528 sums->bytenr = new_bytenr;
4530 btrfs_add_ordered_sum(inode, ordered, sums);
4533 btrfs_put_ordered_extent(ordered);
4537 int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4538 struct btrfs_root *root, struct extent_buffer *buf,
4539 struct extent_buffer *cow)
4541 struct reloc_control *rc;
4542 struct backref_node *node;
4547 rc = root->fs_info->reloc_ctl;
4551 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4552 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4554 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
4555 if (buf == root->node)
4556 __update_reloc_root(root, cow->start);
4559 level = btrfs_header_level(buf);
4560 if (btrfs_header_generation(buf) <=
4561 btrfs_root_last_snapshot(&root->root_item))
4564 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4565 rc->create_reloc_tree) {
4566 WARN_ON(!first_cow && level == 0);
4568 node = rc->backref_cache.path[level];
4569 BUG_ON(node->bytenr != buf->start &&
4570 node->new_bytenr != buf->start);
4572 drop_node_buffer(node);
4573 extent_buffer_get(cow);
4575 node->new_bytenr = cow->start;
4577 if (!node->pending) {
4578 list_move_tail(&node->list,
4579 &rc->backref_cache.pending[level]);
4584 __mark_block_processed(rc, node);
4586 if (first_cow && level > 0)
4587 rc->nodes_relocated += buf->len;
4590 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
4591 ret = replace_file_extents(trans, rc, root, cow);
4596 * called before creating snapshot. it calculates metadata reservation
4597 * requried for relocating tree blocks in the snapshot
4599 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4600 struct btrfs_pending_snapshot *pending,
4601 u64 *bytes_to_reserve)
4603 struct btrfs_root *root;
4604 struct reloc_control *rc;
4606 root = pending->root;
4607 if (!root->reloc_root)
4610 rc = root->fs_info->reloc_ctl;
4611 if (!rc->merge_reloc_tree)
4614 root = root->reloc_root;
4615 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4617 * relocation is in the stage of merging trees. the space
4618 * used by merging a reloc tree is twice the size of
4619 * relocated tree nodes in the worst case. half for cowing
4620 * the reloc tree, half for cowing the fs tree. the space
4621 * used by cowing the reloc tree will be freed after the
4622 * tree is dropped. if we create snapshot, cowing the fs
4623 * tree may use more space than it frees. so we need
4624 * reserve extra space.
4626 *bytes_to_reserve += rc->nodes_relocated;
4630 * called after snapshot is created. migrate block reservation
4631 * and create reloc root for the newly created snapshot
4633 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4634 struct btrfs_pending_snapshot *pending)
4636 struct btrfs_root *root = pending->root;
4637 struct btrfs_root *reloc_root;
4638 struct btrfs_root *new_root;
4639 struct reloc_control *rc;
4642 if (!root->reloc_root)
4645 rc = root->fs_info->reloc_ctl;
4646 rc->merging_rsv_size += rc->nodes_relocated;
4648 if (rc->merge_reloc_tree) {
4649 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4651 rc->nodes_relocated);
4656 new_root = pending->snap;
4657 reloc_root = create_reloc_root(trans, root->reloc_root,
4658 new_root->root_key.objectid);
4659 if (IS_ERR(reloc_root))
4660 return PTR_ERR(reloc_root);
4662 ret = __add_reloc_root(reloc_root);
4664 new_root->reloc_root = reloc_root;
4666 if (rc->create_reloc_tree)
4667 ret = clone_backref_node(trans, rc, root, reloc_root);