2 * Copyright (C) 2009 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
27 #include "transaction.h"
30 #include "btrfs_inode.h"
31 #include "async-thread.h"
32 #include "free-space-cache.h"
33 #include "inode-map.h"
36 * backref_node, mapping_node and tree_block start with this
39 struct rb_node rb_node;
44 * present a tree block in the backref cache
47 struct rb_node rb_node;
51 /* objectid of tree block owner, can be not uptodate */
53 /* link to pending, changed or detached list */
54 struct list_head list;
55 /* list of upper level blocks reference this block */
56 struct list_head upper;
57 /* list of child blocks in the cache */
58 struct list_head lower;
59 /* NULL if this node is not tree root */
60 struct btrfs_root *root;
61 /* extent buffer got by COW the block */
62 struct extent_buffer *eb;
63 /* level of tree block */
65 /* is the block in non-reference counted tree */
66 unsigned int cowonly:1;
67 /* 1 if no child node in the cache */
68 unsigned int lowest:1;
69 /* is the extent buffer locked */
70 unsigned int locked:1;
71 /* has the block been processed */
72 unsigned int processed:1;
73 /* have backrefs of this block been checked */
74 unsigned int checked:1;
76 * 1 if corresponding block has been cowed but some upper
77 * level block pointers may not point to the new location
79 unsigned int pending:1;
81 * 1 if the backref node isn't connected to any other
84 unsigned int detached:1;
88 * present a block pointer in the backref cache
91 struct list_head list[2];
92 struct backref_node *node[2];
98 struct backref_cache {
99 /* red black tree of all backref nodes in the cache */
100 struct rb_root rb_root;
101 /* for passing backref nodes to btrfs_reloc_cow_block */
102 struct backref_node *path[BTRFS_MAX_LEVEL];
104 * list of blocks that have been cowed but some block
105 * pointers in upper level blocks may not reflect the
108 struct list_head pending[BTRFS_MAX_LEVEL];
109 /* list of backref nodes with no child node */
110 struct list_head leaves;
111 /* list of blocks that have been cowed in current transaction */
112 struct list_head changed;
113 /* list of detached backref node. */
114 struct list_head detached;
123 * map address of tree root to tree
125 struct mapping_node {
126 struct rb_node rb_node;
131 struct mapping_tree {
132 struct rb_root rb_root;
137 * present a tree block to process
140 struct rb_node rb_node;
142 struct btrfs_key key;
143 unsigned int level:8;
144 unsigned int key_ready:1;
147 #define MAX_EXTENTS 128
149 struct file_extent_cluster {
152 u64 boundary[MAX_EXTENTS];
156 struct reloc_control {
157 /* block group to relocate */
158 struct btrfs_block_group_cache *block_group;
160 struct btrfs_root *extent_root;
161 /* inode for moving data */
162 struct inode *data_inode;
164 struct btrfs_block_rsv *block_rsv;
166 struct backref_cache backref_cache;
168 struct file_extent_cluster cluster;
169 /* tree blocks have been processed */
170 struct extent_io_tree processed_blocks;
171 /* map start of tree root to corresponding reloc tree */
172 struct mapping_tree reloc_root_tree;
173 /* list of reloc trees */
174 struct list_head reloc_roots;
175 /* size of metadata reservation for merging reloc trees */
176 u64 merging_rsv_size;
177 /* size of relocated tree nodes */
183 unsigned int stage:8;
184 unsigned int create_reloc_tree:1;
185 unsigned int merge_reloc_tree:1;
186 unsigned int found_file_extent:1;
187 unsigned int commit_transaction:1;
190 /* stages of data relocation */
191 #define MOVE_DATA_EXTENTS 0
192 #define UPDATE_DATA_PTRS 1
194 static void remove_backref_node(struct backref_cache *cache,
195 struct backref_node *node);
196 static void __mark_block_processed(struct reloc_control *rc,
197 struct backref_node *node);
199 static void mapping_tree_init(struct mapping_tree *tree)
201 tree->rb_root = RB_ROOT;
202 spin_lock_init(&tree->lock);
205 static void backref_cache_init(struct backref_cache *cache)
208 cache->rb_root = RB_ROOT;
209 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
210 INIT_LIST_HEAD(&cache->pending[i]);
211 INIT_LIST_HEAD(&cache->changed);
212 INIT_LIST_HEAD(&cache->detached);
213 INIT_LIST_HEAD(&cache->leaves);
216 static void backref_cache_cleanup(struct backref_cache *cache)
218 struct backref_node *node;
221 while (!list_empty(&cache->detached)) {
222 node = list_entry(cache->detached.next,
223 struct backref_node, list);
224 remove_backref_node(cache, node);
227 while (!list_empty(&cache->leaves)) {
228 node = list_entry(cache->leaves.next,
229 struct backref_node, lower);
230 remove_backref_node(cache, node);
233 cache->last_trans = 0;
235 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
236 BUG_ON(!list_empty(&cache->pending[i]));
237 BUG_ON(!list_empty(&cache->changed));
238 BUG_ON(!list_empty(&cache->detached));
239 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
240 BUG_ON(cache->nr_nodes);
241 BUG_ON(cache->nr_edges);
244 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
246 struct backref_node *node;
248 node = kzalloc(sizeof(*node), GFP_NOFS);
250 INIT_LIST_HEAD(&node->list);
251 INIT_LIST_HEAD(&node->upper);
252 INIT_LIST_HEAD(&node->lower);
253 RB_CLEAR_NODE(&node->rb_node);
259 static void free_backref_node(struct backref_cache *cache,
260 struct backref_node *node)
268 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
270 struct backref_edge *edge;
272 edge = kzalloc(sizeof(*edge), GFP_NOFS);
278 static void free_backref_edge(struct backref_cache *cache,
279 struct backref_edge *edge)
287 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
288 struct rb_node *node)
290 struct rb_node **p = &root->rb_node;
291 struct rb_node *parent = NULL;
292 struct tree_entry *entry;
296 entry = rb_entry(parent, struct tree_entry, rb_node);
298 if (bytenr < entry->bytenr)
300 else if (bytenr > entry->bytenr)
306 rb_link_node(node, parent, p);
307 rb_insert_color(node, root);
311 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
313 struct rb_node *n = root->rb_node;
314 struct tree_entry *entry;
317 entry = rb_entry(n, struct tree_entry, rb_node);
319 if (bytenr < entry->bytenr)
321 else if (bytenr > entry->bytenr)
329 static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
332 struct btrfs_fs_info *fs_info = NULL;
333 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
336 fs_info = bnode->root->fs_info;
337 btrfs_panic(fs_info, errno, "Inconsistency in backref cache "
338 "found at offset %llu\n", bytenr);
342 * walk up backref nodes until reach node presents tree root
344 static struct backref_node *walk_up_backref(struct backref_node *node,
345 struct backref_edge *edges[],
348 struct backref_edge *edge;
351 while (!list_empty(&node->upper)) {
352 edge = list_entry(node->upper.next,
353 struct backref_edge, list[LOWER]);
355 node = edge->node[UPPER];
357 BUG_ON(node->detached);
363 * walk down backref nodes to find start of next reference path
365 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
368 struct backref_edge *edge;
369 struct backref_node *lower;
373 edge = edges[idx - 1];
374 lower = edge->node[LOWER];
375 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
379 edge = list_entry(edge->list[LOWER].next,
380 struct backref_edge, list[LOWER]);
381 edges[idx - 1] = edge;
383 return edge->node[UPPER];
389 static void unlock_node_buffer(struct backref_node *node)
392 btrfs_tree_unlock(node->eb);
397 static void drop_node_buffer(struct backref_node *node)
400 unlock_node_buffer(node);
401 free_extent_buffer(node->eb);
406 static void drop_backref_node(struct backref_cache *tree,
407 struct backref_node *node)
409 BUG_ON(!list_empty(&node->upper));
411 drop_node_buffer(node);
412 list_del(&node->list);
413 list_del(&node->lower);
414 if (!RB_EMPTY_NODE(&node->rb_node))
415 rb_erase(&node->rb_node, &tree->rb_root);
416 free_backref_node(tree, node);
420 * remove a backref node from the backref cache
422 static void remove_backref_node(struct backref_cache *cache,
423 struct backref_node *node)
425 struct backref_node *upper;
426 struct backref_edge *edge;
431 BUG_ON(!node->lowest && !node->detached);
432 while (!list_empty(&node->upper)) {
433 edge = list_entry(node->upper.next, struct backref_edge,
435 upper = edge->node[UPPER];
436 list_del(&edge->list[LOWER]);
437 list_del(&edge->list[UPPER]);
438 free_backref_edge(cache, edge);
440 if (RB_EMPTY_NODE(&upper->rb_node)) {
441 BUG_ON(!list_empty(&node->upper));
442 drop_backref_node(cache, node);
448 * add the node to leaf node list if no other
449 * child block cached.
451 if (list_empty(&upper->lower)) {
452 list_add_tail(&upper->lower, &cache->leaves);
457 drop_backref_node(cache, node);
460 static void update_backref_node(struct backref_cache *cache,
461 struct backref_node *node, u64 bytenr)
463 struct rb_node *rb_node;
464 rb_erase(&node->rb_node, &cache->rb_root);
465 node->bytenr = bytenr;
466 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
468 backref_tree_panic(rb_node, -EEXIST, bytenr);
472 * update backref cache after a transaction commit
474 static int update_backref_cache(struct btrfs_trans_handle *trans,
475 struct backref_cache *cache)
477 struct backref_node *node;
480 if (cache->last_trans == 0) {
481 cache->last_trans = trans->transid;
485 if (cache->last_trans == trans->transid)
489 * detached nodes are used to avoid unnecessary backref
490 * lookup. transaction commit changes the extent tree.
491 * so the detached nodes are no longer useful.
493 while (!list_empty(&cache->detached)) {
494 node = list_entry(cache->detached.next,
495 struct backref_node, list);
496 remove_backref_node(cache, node);
499 while (!list_empty(&cache->changed)) {
500 node = list_entry(cache->changed.next,
501 struct backref_node, list);
502 list_del_init(&node->list);
503 BUG_ON(node->pending);
504 update_backref_node(cache, node, node->new_bytenr);
508 * some nodes can be left in the pending list if there were
509 * errors during processing the pending nodes.
511 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
512 list_for_each_entry(node, &cache->pending[level], list) {
513 BUG_ON(!node->pending);
514 if (node->bytenr == node->new_bytenr)
516 update_backref_node(cache, node, node->new_bytenr);
520 cache->last_trans = 0;
525 static int should_ignore_root(struct btrfs_root *root)
527 struct btrfs_root *reloc_root;
532 reloc_root = root->reloc_root;
536 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
537 root->fs_info->running_transaction->transid - 1)
540 * if there is reloc tree and it was created in previous
541 * transaction backref lookup can find the reloc tree,
542 * so backref node for the fs tree root is useless for
548 * find reloc tree by address of tree root
550 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
553 struct rb_node *rb_node;
554 struct mapping_node *node;
555 struct btrfs_root *root = NULL;
557 spin_lock(&rc->reloc_root_tree.lock);
558 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
560 node = rb_entry(rb_node, struct mapping_node, rb_node);
561 root = (struct btrfs_root *)node->data;
563 spin_unlock(&rc->reloc_root_tree.lock);
567 static int is_cowonly_root(u64 root_objectid)
569 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
570 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
571 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
572 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
573 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
574 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
579 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
582 struct btrfs_key key;
584 key.objectid = root_objectid;
585 key.type = BTRFS_ROOT_ITEM_KEY;
586 if (is_cowonly_root(root_objectid))
589 key.offset = (u64)-1;
591 return btrfs_read_fs_root_no_name(fs_info, &key);
594 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
595 static noinline_for_stack
596 struct btrfs_root *find_tree_root(struct reloc_control *rc,
597 struct extent_buffer *leaf,
598 struct btrfs_extent_ref_v0 *ref0)
600 struct btrfs_root *root;
601 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
602 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
604 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
606 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
607 BUG_ON(IS_ERR(root));
609 if (root->ref_cows &&
610 generation != btrfs_root_generation(&root->root_item))
617 static noinline_for_stack
618 int find_inline_backref(struct extent_buffer *leaf, int slot,
619 unsigned long *ptr, unsigned long *end)
621 struct btrfs_key key;
622 struct btrfs_extent_item *ei;
623 struct btrfs_tree_block_info *bi;
626 btrfs_item_key_to_cpu(leaf, &key, slot);
628 item_size = btrfs_item_size_nr(leaf, slot);
629 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
630 if (item_size < sizeof(*ei)) {
631 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
635 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
636 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
637 BTRFS_EXTENT_FLAG_TREE_BLOCK));
639 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
640 item_size <= sizeof(*ei) + sizeof(*bi)) {
641 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
644 if (key.type == BTRFS_METADATA_ITEM_KEY &&
645 item_size <= sizeof(*ei)) {
646 WARN_ON(item_size < sizeof(*ei));
650 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
651 bi = (struct btrfs_tree_block_info *)(ei + 1);
652 *ptr = (unsigned long)(bi + 1);
654 *ptr = (unsigned long)(ei + 1);
656 *end = (unsigned long)ei + item_size;
661 * build backref tree for a given tree block. root of the backref tree
662 * corresponds the tree block, leaves of the backref tree correspond
663 * roots of b-trees that reference the tree block.
665 * the basic idea of this function is check backrefs of a given block
666 * to find upper level blocks that refernece the block, and then check
667 * bakcrefs of these upper level blocks recursively. the recursion stop
668 * when tree root is reached or backrefs for the block is cached.
670 * NOTE: if we find backrefs for a block are cached, we know backrefs
671 * for all upper level blocks that directly/indirectly reference the
672 * block are also cached.
674 static noinline_for_stack
675 struct backref_node *build_backref_tree(struct reloc_control *rc,
676 struct btrfs_key *node_key,
677 int level, u64 bytenr)
679 struct backref_cache *cache = &rc->backref_cache;
680 struct btrfs_path *path1;
681 struct btrfs_path *path2;
682 struct extent_buffer *eb;
683 struct btrfs_root *root;
684 struct backref_node *cur;
685 struct backref_node *upper;
686 struct backref_node *lower;
687 struct backref_node *node = NULL;
688 struct backref_node *exist = NULL;
689 struct backref_edge *edge;
690 struct rb_node *rb_node;
691 struct btrfs_key key;
699 bool need_check = true;
701 path1 = btrfs_alloc_path();
702 path2 = btrfs_alloc_path();
703 if (!path1 || !path2) {
710 node = alloc_backref_node(cache);
716 node->bytenr = bytenr;
723 key.objectid = cur->bytenr;
724 key.type = BTRFS_METADATA_ITEM_KEY;
725 key.offset = (u64)-1;
727 path1->search_commit_root = 1;
728 path1->skip_locking = 1;
729 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
735 BUG_ON(!ret || !path1->slots[0]);
739 WARN_ON(cur->checked);
740 if (!list_empty(&cur->upper)) {
742 * the backref was added previously when processing
743 * backref of type BTRFS_TREE_BLOCK_REF_KEY
745 BUG_ON(!list_is_singular(&cur->upper));
746 edge = list_entry(cur->upper.next, struct backref_edge,
748 BUG_ON(!list_empty(&edge->list[UPPER]));
749 exist = edge->node[UPPER];
751 * add the upper level block to pending list if we need
755 list_add_tail(&edge->list[UPPER], &list);
762 eb = path1->nodes[0];
765 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
766 ret = btrfs_next_leaf(rc->extent_root, path1);
773 eb = path1->nodes[0];
776 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
777 if (key.objectid != cur->bytenr) {
782 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
783 key.type == BTRFS_METADATA_ITEM_KEY) {
784 ret = find_inline_backref(eb, path1->slots[0],
792 /* update key for inline back ref */
793 struct btrfs_extent_inline_ref *iref;
794 iref = (struct btrfs_extent_inline_ref *)ptr;
795 key.type = btrfs_extent_inline_ref_type(eb, iref);
796 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
797 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
798 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
802 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
803 exist->owner == key.offset) ||
804 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
805 exist->bytenr == key.offset))) {
810 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
811 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
812 key.type == BTRFS_EXTENT_REF_V0_KEY) {
813 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
814 struct btrfs_extent_ref_v0 *ref0;
815 ref0 = btrfs_item_ptr(eb, path1->slots[0],
816 struct btrfs_extent_ref_v0);
817 if (key.objectid == key.offset) {
818 root = find_tree_root(rc, eb, ref0);
819 if (root && !should_ignore_root(root))
822 list_add(&cur->list, &useless);
825 if (is_cowonly_root(btrfs_ref_root_v0(eb,
830 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
831 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
833 if (key.objectid == key.offset) {
835 * only root blocks of reloc trees use
836 * backref of this type.
838 root = find_reloc_root(rc, cur->bytenr);
844 edge = alloc_backref_edge(cache);
849 rb_node = tree_search(&cache->rb_root, key.offset);
851 upper = alloc_backref_node(cache);
853 free_backref_edge(cache, edge);
857 upper->bytenr = key.offset;
858 upper->level = cur->level + 1;
860 * backrefs for the upper level block isn't
861 * cached, add the block to pending list
863 list_add_tail(&edge->list[UPPER], &list);
865 upper = rb_entry(rb_node, struct backref_node,
867 BUG_ON(!upper->checked);
868 INIT_LIST_HEAD(&edge->list[UPPER]);
870 list_add_tail(&edge->list[LOWER], &cur->upper);
871 edge->node[LOWER] = cur;
872 edge->node[UPPER] = upper;
875 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
879 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
880 root = read_fs_root(rc->extent_root->fs_info, key.offset);
889 if (btrfs_root_level(&root->root_item) == cur->level) {
891 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
893 if (should_ignore_root(root))
894 list_add(&cur->list, &useless);
900 level = cur->level + 1;
903 * searching the tree to find upper level blocks
904 * reference the block.
906 path2->search_commit_root = 1;
907 path2->skip_locking = 1;
908 path2->lowest_level = level;
909 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
910 path2->lowest_level = 0;
915 if (ret > 0 && path2->slots[level] > 0)
916 path2->slots[level]--;
918 eb = path2->nodes[level];
919 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
924 for (; level < BTRFS_MAX_LEVEL; level++) {
925 if (!path2->nodes[level]) {
926 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
928 if (should_ignore_root(root))
929 list_add(&lower->list, &useless);
935 edge = alloc_backref_edge(cache);
941 eb = path2->nodes[level];
942 rb_node = tree_search(&cache->rb_root, eb->start);
944 upper = alloc_backref_node(cache);
946 free_backref_edge(cache, edge);
950 upper->bytenr = eb->start;
951 upper->owner = btrfs_header_owner(eb);
952 upper->level = lower->level + 1;
957 * if we know the block isn't shared
958 * we can void checking its backrefs.
960 if (btrfs_block_can_be_shared(root, eb))
966 * add the block to pending list if we
967 * need check its backrefs, we only do this once
968 * while walking up a tree as we will catch
969 * anything else later on.
971 if (!upper->checked && need_check) {
973 list_add_tail(&edge->list[UPPER],
976 INIT_LIST_HEAD(&edge->list[UPPER]);
978 upper = rb_entry(rb_node, struct backref_node,
980 BUG_ON(!upper->checked);
981 INIT_LIST_HEAD(&edge->list[UPPER]);
983 upper->owner = btrfs_header_owner(eb);
985 list_add_tail(&edge->list[LOWER], &lower->upper);
986 edge->node[LOWER] = lower;
987 edge->node[UPPER] = upper;
994 btrfs_release_path(path2);
997 ptr += btrfs_extent_inline_ref_size(key.type);
1007 btrfs_release_path(path1);
1012 /* the pending list isn't empty, take the first block to process */
1013 if (!list_empty(&list)) {
1014 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1015 list_del_init(&edge->list[UPPER]);
1016 cur = edge->node[UPPER];
1021 * everything goes well, connect backref nodes and insert backref nodes
1024 BUG_ON(!node->checked);
1025 cowonly = node->cowonly;
1027 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1030 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1031 list_add_tail(&node->lower, &cache->leaves);
1034 list_for_each_entry(edge, &node->upper, list[LOWER])
1035 list_add_tail(&edge->list[UPPER], &list);
1037 while (!list_empty(&list)) {
1038 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1039 list_del_init(&edge->list[UPPER]);
1040 upper = edge->node[UPPER];
1041 if (upper->detached) {
1042 list_del(&edge->list[LOWER]);
1043 lower = edge->node[LOWER];
1044 free_backref_edge(cache, edge);
1045 if (list_empty(&lower->upper))
1046 list_add(&lower->list, &useless);
1050 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1051 if (upper->lowest) {
1052 list_del_init(&upper->lower);
1056 list_add_tail(&edge->list[UPPER], &upper->lower);
1060 BUG_ON(!upper->checked);
1061 BUG_ON(cowonly != upper->cowonly);
1063 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1066 backref_tree_panic(rb_node, -EEXIST,
1070 list_add_tail(&edge->list[UPPER], &upper->lower);
1072 list_for_each_entry(edge, &upper->upper, list[LOWER])
1073 list_add_tail(&edge->list[UPPER], &list);
1076 * process useless backref nodes. backref nodes for tree leaves
1077 * are deleted from the cache. backref nodes for upper level
1078 * tree blocks are left in the cache to avoid unnecessary backref
1081 while (!list_empty(&useless)) {
1082 upper = list_entry(useless.next, struct backref_node, list);
1083 list_del_init(&upper->list);
1084 BUG_ON(!list_empty(&upper->upper));
1087 if (upper->lowest) {
1088 list_del_init(&upper->lower);
1091 while (!list_empty(&upper->lower)) {
1092 edge = list_entry(upper->lower.next,
1093 struct backref_edge, list[UPPER]);
1094 list_del(&edge->list[UPPER]);
1095 list_del(&edge->list[LOWER]);
1096 lower = edge->node[LOWER];
1097 free_backref_edge(cache, edge);
1099 if (list_empty(&lower->upper))
1100 list_add(&lower->list, &useless);
1102 __mark_block_processed(rc, upper);
1103 if (upper->level > 0) {
1104 list_add(&upper->list, &cache->detached);
1105 upper->detached = 1;
1107 rb_erase(&upper->rb_node, &cache->rb_root);
1108 free_backref_node(cache, upper);
1112 btrfs_free_path(path1);
1113 btrfs_free_path(path2);
1115 while (!list_empty(&useless)) {
1116 lower = list_entry(useless.next,
1117 struct backref_node, upper);
1118 list_del_init(&lower->upper);
1121 INIT_LIST_HEAD(&list);
1123 if (RB_EMPTY_NODE(&upper->rb_node)) {
1124 list_splice_tail(&upper->upper, &list);
1125 free_backref_node(cache, upper);
1128 if (list_empty(&list))
1131 edge = list_entry(list.next, struct backref_edge,
1133 list_del(&edge->list[LOWER]);
1134 upper = edge->node[UPPER];
1135 free_backref_edge(cache, edge);
1137 return ERR_PTR(err);
1139 BUG_ON(node && node->detached);
1144 * helper to add backref node for the newly created snapshot.
1145 * the backref node is created by cloning backref node that
1146 * corresponds to root of source tree
1148 static int clone_backref_node(struct btrfs_trans_handle *trans,
1149 struct reloc_control *rc,
1150 struct btrfs_root *src,
1151 struct btrfs_root *dest)
1153 struct btrfs_root *reloc_root = src->reloc_root;
1154 struct backref_cache *cache = &rc->backref_cache;
1155 struct backref_node *node = NULL;
1156 struct backref_node *new_node;
1157 struct backref_edge *edge;
1158 struct backref_edge *new_edge;
1159 struct rb_node *rb_node;
1161 if (cache->last_trans > 0)
1162 update_backref_cache(trans, cache);
1164 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1166 node = rb_entry(rb_node, struct backref_node, rb_node);
1170 BUG_ON(node->new_bytenr != reloc_root->node->start);
1174 rb_node = tree_search(&cache->rb_root,
1175 reloc_root->commit_root->start);
1177 node = rb_entry(rb_node, struct backref_node,
1179 BUG_ON(node->detached);
1186 new_node = alloc_backref_node(cache);
1190 new_node->bytenr = dest->node->start;
1191 new_node->level = node->level;
1192 new_node->lowest = node->lowest;
1193 new_node->checked = 1;
1194 new_node->root = dest;
1196 if (!node->lowest) {
1197 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1198 new_edge = alloc_backref_edge(cache);
1202 new_edge->node[UPPER] = new_node;
1203 new_edge->node[LOWER] = edge->node[LOWER];
1204 list_add_tail(&new_edge->list[UPPER],
1208 list_add_tail(&new_node->lower, &cache->leaves);
1211 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1212 &new_node->rb_node);
1214 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1216 if (!new_node->lowest) {
1217 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1218 list_add_tail(&new_edge->list[LOWER],
1219 &new_edge->node[LOWER]->upper);
1224 while (!list_empty(&new_node->lower)) {
1225 new_edge = list_entry(new_node->lower.next,
1226 struct backref_edge, list[UPPER]);
1227 list_del(&new_edge->list[UPPER]);
1228 free_backref_edge(cache, new_edge);
1230 free_backref_node(cache, new_node);
1235 * helper to add 'address of tree root -> reloc tree' mapping
1237 static int __must_check __add_reloc_root(struct btrfs_root *root)
1239 struct rb_node *rb_node;
1240 struct mapping_node *node;
1241 struct reloc_control *rc = root->fs_info->reloc_ctl;
1243 node = kmalloc(sizeof(*node), GFP_NOFS);
1247 node->bytenr = root->node->start;
1250 spin_lock(&rc->reloc_root_tree.lock);
1251 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1252 node->bytenr, &node->rb_node);
1253 spin_unlock(&rc->reloc_root_tree.lock);
1255 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1256 "for start=%llu while inserting into relocation "
1257 "tree\n", node->bytenr);
1262 list_add_tail(&root->root_list, &rc->reloc_roots);
1267 * helper to update/delete the 'address of tree root -> reloc tree'
1270 static int __update_reloc_root(struct btrfs_root *root, int del)
1272 struct rb_node *rb_node;
1273 struct mapping_node *node = NULL;
1274 struct reloc_control *rc = root->fs_info->reloc_ctl;
1276 spin_lock(&rc->reloc_root_tree.lock);
1277 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1278 root->commit_root->start);
1280 node = rb_entry(rb_node, struct mapping_node, rb_node);
1281 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1283 spin_unlock(&rc->reloc_root_tree.lock);
1287 BUG_ON((struct btrfs_root *)node->data != root);
1290 spin_lock(&rc->reloc_root_tree.lock);
1291 node->bytenr = root->node->start;
1292 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1293 node->bytenr, &node->rb_node);
1294 spin_unlock(&rc->reloc_root_tree.lock);
1296 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1298 spin_lock(&root->fs_info->trans_lock);
1299 list_del_init(&root->root_list);
1300 spin_unlock(&root->fs_info->trans_lock);
1306 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1307 struct btrfs_root *root, u64 objectid)
1309 struct btrfs_root *reloc_root;
1310 struct extent_buffer *eb;
1311 struct btrfs_root_item *root_item;
1312 struct btrfs_key root_key;
1316 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1319 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1320 root_key.type = BTRFS_ROOT_ITEM_KEY;
1321 root_key.offset = objectid;
1323 if (root->root_key.objectid == objectid) {
1324 /* called by btrfs_init_reloc_root */
1325 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1326 BTRFS_TREE_RELOC_OBJECTID);
1329 last_snap = btrfs_root_last_snapshot(&root->root_item);
1330 btrfs_set_root_last_snapshot(&root->root_item,
1331 trans->transid - 1);
1334 * called by btrfs_reloc_post_snapshot_hook.
1335 * the source tree is a reloc tree, all tree blocks
1336 * modified after it was created have RELOC flag
1337 * set in their headers. so it's OK to not update
1338 * the 'last_snapshot'.
1340 ret = btrfs_copy_root(trans, root, root->node, &eb,
1341 BTRFS_TREE_RELOC_OBJECTID);
1345 memcpy(root_item, &root->root_item, sizeof(*root_item));
1346 btrfs_set_root_bytenr(root_item, eb->start);
1347 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1348 btrfs_set_root_generation(root_item, trans->transid);
1350 if (root->root_key.objectid == objectid) {
1351 btrfs_set_root_refs(root_item, 0);
1352 memset(&root_item->drop_progress, 0,
1353 sizeof(struct btrfs_disk_key));
1354 root_item->drop_level = 0;
1356 * abuse rtransid, it is safe because it is impossible to
1357 * receive data into a relocation tree.
1359 btrfs_set_root_rtransid(root_item, last_snap);
1360 btrfs_set_root_otransid(root_item, trans->transid);
1363 btrfs_tree_unlock(eb);
1364 free_extent_buffer(eb);
1366 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1367 &root_key, root_item);
1371 reloc_root = btrfs_read_fs_root(root->fs_info->tree_root, &root_key);
1372 BUG_ON(IS_ERR(reloc_root));
1373 reloc_root->last_trans = trans->transid;
1378 * create reloc tree for a given fs tree. reloc tree is just a
1379 * snapshot of the fs tree with special root objectid.
1381 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1382 struct btrfs_root *root)
1384 struct btrfs_root *reloc_root;
1385 struct reloc_control *rc = root->fs_info->reloc_ctl;
1389 if (root->reloc_root) {
1390 reloc_root = root->reloc_root;
1391 reloc_root->last_trans = trans->transid;
1395 if (!rc || !rc->create_reloc_tree ||
1396 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1399 if (!trans->block_rsv) {
1400 trans->block_rsv = rc->block_rsv;
1403 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1405 trans->block_rsv = NULL;
1407 ret = __add_reloc_root(reloc_root);
1409 root->reloc_root = reloc_root;
1414 * update root item of reloc tree
1416 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1417 struct btrfs_root *root)
1419 struct btrfs_root *reloc_root;
1420 struct btrfs_root_item *root_item;
1424 if (!root->reloc_root)
1427 reloc_root = root->reloc_root;
1428 root_item = &reloc_root->root_item;
1430 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1431 btrfs_root_refs(root_item) == 0) {
1432 root->reloc_root = NULL;
1436 __update_reloc_root(reloc_root, del);
1438 if (reloc_root->commit_root != reloc_root->node) {
1439 btrfs_set_root_node(root_item, reloc_root->node);
1440 free_extent_buffer(reloc_root->commit_root);
1441 reloc_root->commit_root = btrfs_root_node(reloc_root);
1444 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1445 &reloc_root->root_key, root_item);
1453 * helper to find first cached inode with inode number >= objectid
1456 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1458 struct rb_node *node;
1459 struct rb_node *prev;
1460 struct btrfs_inode *entry;
1461 struct inode *inode;
1463 spin_lock(&root->inode_lock);
1465 node = root->inode_tree.rb_node;
1469 entry = rb_entry(node, struct btrfs_inode, rb_node);
1471 if (objectid < btrfs_ino(&entry->vfs_inode))
1472 node = node->rb_left;
1473 else if (objectid > btrfs_ino(&entry->vfs_inode))
1474 node = node->rb_right;
1480 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1481 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1485 prev = rb_next(prev);
1489 entry = rb_entry(node, struct btrfs_inode, rb_node);
1490 inode = igrab(&entry->vfs_inode);
1492 spin_unlock(&root->inode_lock);
1496 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1497 if (cond_resched_lock(&root->inode_lock))
1500 node = rb_next(node);
1502 spin_unlock(&root->inode_lock);
1506 static int in_block_group(u64 bytenr,
1507 struct btrfs_block_group_cache *block_group)
1509 if (bytenr >= block_group->key.objectid &&
1510 bytenr < block_group->key.objectid + block_group->key.offset)
1516 * get new location of data
1518 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1519 u64 bytenr, u64 num_bytes)
1521 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1522 struct btrfs_path *path;
1523 struct btrfs_file_extent_item *fi;
1524 struct extent_buffer *leaf;
1527 path = btrfs_alloc_path();
1531 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1532 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1541 leaf = path->nodes[0];
1542 fi = btrfs_item_ptr(leaf, path->slots[0],
1543 struct btrfs_file_extent_item);
1545 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1546 btrfs_file_extent_compression(leaf, fi) ||
1547 btrfs_file_extent_encryption(leaf, fi) ||
1548 btrfs_file_extent_other_encoding(leaf, fi));
1550 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1555 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1558 btrfs_free_path(path);
1563 * update file extent items in the tree leaf to point to
1564 * the new locations.
1566 static noinline_for_stack
1567 int replace_file_extents(struct btrfs_trans_handle *trans,
1568 struct reloc_control *rc,
1569 struct btrfs_root *root,
1570 struct extent_buffer *leaf)
1572 struct btrfs_key key;
1573 struct btrfs_file_extent_item *fi;
1574 struct inode *inode = NULL;
1586 if (rc->stage != UPDATE_DATA_PTRS)
1589 /* reloc trees always use full backref */
1590 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1591 parent = leaf->start;
1595 nritems = btrfs_header_nritems(leaf);
1596 for (i = 0; i < nritems; i++) {
1598 btrfs_item_key_to_cpu(leaf, &key, i);
1599 if (key.type != BTRFS_EXTENT_DATA_KEY)
1601 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1602 if (btrfs_file_extent_type(leaf, fi) ==
1603 BTRFS_FILE_EXTENT_INLINE)
1605 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1606 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1609 if (!in_block_group(bytenr, rc->block_group))
1613 * if we are modifying block in fs tree, wait for readpage
1614 * to complete and drop the extent cache
1616 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1618 inode = find_next_inode(root, key.objectid);
1620 } else if (inode && btrfs_ino(inode) < key.objectid) {
1621 btrfs_add_delayed_iput(inode);
1622 inode = find_next_inode(root, key.objectid);
1624 if (inode && btrfs_ino(inode) == key.objectid) {
1626 btrfs_file_extent_num_bytes(leaf, fi);
1627 WARN_ON(!IS_ALIGNED(key.offset,
1629 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1631 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1636 btrfs_drop_extent_cache(inode, key.offset, end,
1638 unlock_extent(&BTRFS_I(inode)->io_tree,
1643 ret = get_new_location(rc->data_inode, &new_bytenr,
1651 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1654 key.offset -= btrfs_file_extent_offset(leaf, fi);
1655 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1657 btrfs_header_owner(leaf),
1658 key.objectid, key.offset, 1);
1661 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1662 parent, btrfs_header_owner(leaf),
1663 key.objectid, key.offset, 1);
1667 btrfs_mark_buffer_dirty(leaf);
1669 btrfs_add_delayed_iput(inode);
1673 static noinline_for_stack
1674 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1675 struct btrfs_path *path, int level)
1677 struct btrfs_disk_key key1;
1678 struct btrfs_disk_key key2;
1679 btrfs_node_key(eb, &key1, slot);
1680 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1681 return memcmp(&key1, &key2, sizeof(key1));
1685 * try to replace tree blocks in fs tree with the new blocks
1686 * in reloc tree. tree blocks haven't been modified since the
1687 * reloc tree was create can be replaced.
1689 * if a block was replaced, level of the block + 1 is returned.
1690 * if no block got replaced, 0 is returned. if there are other
1691 * errors, a negative error number is returned.
1693 static noinline_for_stack
1694 int replace_path(struct btrfs_trans_handle *trans,
1695 struct btrfs_root *dest, struct btrfs_root *src,
1696 struct btrfs_path *path, struct btrfs_key *next_key,
1697 int lowest_level, int max_level)
1699 struct extent_buffer *eb;
1700 struct extent_buffer *parent;
1701 struct btrfs_key key;
1713 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1714 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1716 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1718 slot = path->slots[lowest_level];
1719 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1721 eb = btrfs_lock_root_node(dest);
1722 btrfs_set_lock_blocking(eb);
1723 level = btrfs_header_level(eb);
1725 if (level < lowest_level) {
1726 btrfs_tree_unlock(eb);
1727 free_extent_buffer(eb);
1732 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1735 btrfs_set_lock_blocking(eb);
1738 next_key->objectid = (u64)-1;
1739 next_key->type = (u8)-1;
1740 next_key->offset = (u64)-1;
1745 level = btrfs_header_level(parent);
1746 BUG_ON(level < lowest_level);
1748 ret = btrfs_bin_search(parent, &key, level, &slot);
1749 if (ret && slot > 0)
1752 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1753 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1755 old_bytenr = btrfs_node_blockptr(parent, slot);
1756 blocksize = btrfs_level_size(dest, level - 1);
1757 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1759 if (level <= max_level) {
1760 eb = path->nodes[level];
1761 new_bytenr = btrfs_node_blockptr(eb,
1762 path->slots[level]);
1763 new_ptr_gen = btrfs_node_ptr_generation(eb,
1764 path->slots[level]);
1770 if (new_bytenr > 0 && new_bytenr == old_bytenr) {
1776 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1777 memcmp_node_keys(parent, slot, path, level)) {
1778 if (level <= lowest_level) {
1783 eb = read_tree_block(dest, old_bytenr, blocksize,
1785 if (!eb || !extent_buffer_uptodate(eb)) {
1786 ret = (!eb) ? -ENOMEM : -EIO;
1787 free_extent_buffer(eb);
1790 btrfs_tree_lock(eb);
1792 ret = btrfs_cow_block(trans, dest, eb, parent,
1796 btrfs_set_lock_blocking(eb);
1798 btrfs_tree_unlock(parent);
1799 free_extent_buffer(parent);
1806 btrfs_tree_unlock(parent);
1807 free_extent_buffer(parent);
1812 btrfs_node_key_to_cpu(path->nodes[level], &key,
1813 path->slots[level]);
1814 btrfs_release_path(path);
1816 path->lowest_level = level;
1817 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1818 path->lowest_level = 0;
1822 * swap blocks in fs tree and reloc tree.
1824 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1825 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1826 btrfs_mark_buffer_dirty(parent);
1828 btrfs_set_node_blockptr(path->nodes[level],
1829 path->slots[level], old_bytenr);
1830 btrfs_set_node_ptr_generation(path->nodes[level],
1831 path->slots[level], old_ptr_gen);
1832 btrfs_mark_buffer_dirty(path->nodes[level]);
1834 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1835 path->nodes[level]->start,
1836 src->root_key.objectid, level - 1, 0,
1839 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1840 0, dest->root_key.objectid, level - 1,
1844 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1845 path->nodes[level]->start,
1846 src->root_key.objectid, level - 1, 0,
1850 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1851 0, dest->root_key.objectid, level - 1,
1855 btrfs_unlock_up_safe(path, 0);
1860 btrfs_tree_unlock(parent);
1861 free_extent_buffer(parent);
1866 * helper to find next relocated block in reloc tree
1868 static noinline_for_stack
1869 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1872 struct extent_buffer *eb;
1877 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1879 for (i = 0; i < *level; i++) {
1880 free_extent_buffer(path->nodes[i]);
1881 path->nodes[i] = NULL;
1884 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1885 eb = path->nodes[i];
1886 nritems = btrfs_header_nritems(eb);
1887 while (path->slots[i] + 1 < nritems) {
1889 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1896 free_extent_buffer(path->nodes[i]);
1897 path->nodes[i] = NULL;
1903 * walk down reloc tree to find relocated block of lowest level
1905 static noinline_for_stack
1906 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1909 struct extent_buffer *eb = NULL;
1917 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1919 for (i = *level; i > 0; i--) {
1920 eb = path->nodes[i];
1921 nritems = btrfs_header_nritems(eb);
1922 while (path->slots[i] < nritems) {
1923 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1924 if (ptr_gen > last_snapshot)
1928 if (path->slots[i] >= nritems) {
1939 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
1940 blocksize = btrfs_level_size(root, i - 1);
1941 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
1942 if (!eb || !extent_buffer_uptodate(eb)) {
1943 free_extent_buffer(eb);
1946 BUG_ON(btrfs_header_level(eb) != i - 1);
1947 path->nodes[i - 1] = eb;
1948 path->slots[i - 1] = 0;
1954 * invalidate extent cache for file extents whose key in range of
1955 * [min_key, max_key)
1957 static int invalidate_extent_cache(struct btrfs_root *root,
1958 struct btrfs_key *min_key,
1959 struct btrfs_key *max_key)
1961 struct inode *inode = NULL;
1966 objectid = min_key->objectid;
1971 if (objectid > max_key->objectid)
1974 inode = find_next_inode(root, objectid);
1977 ino = btrfs_ino(inode);
1979 if (ino > max_key->objectid) {
1985 if (!S_ISREG(inode->i_mode))
1988 if (unlikely(min_key->objectid == ino)) {
1989 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
1991 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
1994 start = min_key->offset;
1995 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
2001 if (unlikely(max_key->objectid == ino)) {
2002 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2004 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2007 if (max_key->offset == 0)
2009 end = max_key->offset;
2010 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2017 /* the lock_extent waits for readpage to complete */
2018 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2019 btrfs_drop_extent_cache(inode, start, end, 1);
2020 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2025 static int find_next_key(struct btrfs_path *path, int level,
2026 struct btrfs_key *key)
2029 while (level < BTRFS_MAX_LEVEL) {
2030 if (!path->nodes[level])
2032 if (path->slots[level] + 1 <
2033 btrfs_header_nritems(path->nodes[level])) {
2034 btrfs_node_key_to_cpu(path->nodes[level], key,
2035 path->slots[level] + 1);
2044 * merge the relocated tree blocks in reloc tree with corresponding
2047 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2048 struct btrfs_root *root)
2050 LIST_HEAD(inode_list);
2051 struct btrfs_key key;
2052 struct btrfs_key next_key;
2053 struct btrfs_trans_handle *trans;
2054 struct btrfs_root *reloc_root;
2055 struct btrfs_root_item *root_item;
2056 struct btrfs_path *path;
2057 struct extent_buffer *leaf;
2065 path = btrfs_alloc_path();
2070 reloc_root = root->reloc_root;
2071 root_item = &reloc_root->root_item;
2073 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2074 level = btrfs_root_level(root_item);
2075 extent_buffer_get(reloc_root->node);
2076 path->nodes[level] = reloc_root->node;
2077 path->slots[level] = 0;
2079 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2081 level = root_item->drop_level;
2083 path->lowest_level = level;
2084 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2085 path->lowest_level = 0;
2087 btrfs_free_path(path);
2091 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2092 path->slots[level]);
2093 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2095 btrfs_unlock_up_safe(path, 0);
2098 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2099 memset(&next_key, 0, sizeof(next_key));
2102 trans = btrfs_start_transaction(root, 0);
2103 BUG_ON(IS_ERR(trans));
2104 trans->block_rsv = rc->block_rsv;
2106 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2107 BTRFS_RESERVE_FLUSH_ALL);
2109 BUG_ON(ret != -EAGAIN);
2110 ret = btrfs_commit_transaction(trans, root);
2118 ret = walk_down_reloc_tree(reloc_root, path, &level);
2126 if (!find_next_key(path, level, &key) &&
2127 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2130 ret = replace_path(trans, root, reloc_root, path,
2131 &next_key, level, max_level);
2140 btrfs_node_key_to_cpu(path->nodes[level], &key,
2141 path->slots[level]);
2145 ret = walk_up_reloc_tree(reloc_root, path, &level);
2151 * save the merging progress in the drop_progress.
2152 * this is OK since root refs == 1 in this case.
2154 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2155 path->slots[level]);
2156 root_item->drop_level = level;
2158 btrfs_end_transaction_throttle(trans, root);
2160 btrfs_btree_balance_dirty(root);
2162 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2163 invalidate_extent_cache(root, &key, &next_key);
2167 * handle the case only one block in the fs tree need to be
2168 * relocated and the block is tree root.
2170 leaf = btrfs_lock_root_node(root);
2171 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2172 btrfs_tree_unlock(leaf);
2173 free_extent_buffer(leaf);
2177 btrfs_free_path(path);
2180 memset(&root_item->drop_progress, 0,
2181 sizeof(root_item->drop_progress));
2182 root_item->drop_level = 0;
2183 btrfs_set_root_refs(root_item, 0);
2184 btrfs_update_reloc_root(trans, root);
2187 btrfs_end_transaction_throttle(trans, root);
2189 btrfs_btree_balance_dirty(root);
2191 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2192 invalidate_extent_cache(root, &key, &next_key);
2197 static noinline_for_stack
2198 int prepare_to_merge(struct reloc_control *rc, int err)
2200 struct btrfs_root *root = rc->extent_root;
2201 struct btrfs_root *reloc_root;
2202 struct btrfs_trans_handle *trans;
2203 LIST_HEAD(reloc_roots);
2207 mutex_lock(&root->fs_info->reloc_mutex);
2208 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2209 rc->merging_rsv_size += rc->nodes_relocated * 2;
2210 mutex_unlock(&root->fs_info->reloc_mutex);
2214 num_bytes = rc->merging_rsv_size;
2215 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2216 BTRFS_RESERVE_FLUSH_ALL);
2221 trans = btrfs_join_transaction(rc->extent_root);
2222 if (IS_ERR(trans)) {
2224 btrfs_block_rsv_release(rc->extent_root,
2225 rc->block_rsv, num_bytes);
2226 return PTR_ERR(trans);
2230 if (num_bytes != rc->merging_rsv_size) {
2231 btrfs_end_transaction(trans, rc->extent_root);
2232 btrfs_block_rsv_release(rc->extent_root,
2233 rc->block_rsv, num_bytes);
2238 rc->merge_reloc_tree = 1;
2240 while (!list_empty(&rc->reloc_roots)) {
2241 reloc_root = list_entry(rc->reloc_roots.next,
2242 struct btrfs_root, root_list);
2243 list_del_init(&reloc_root->root_list);
2245 root = read_fs_root(reloc_root->fs_info,
2246 reloc_root->root_key.offset);
2247 BUG_ON(IS_ERR(root));
2248 BUG_ON(root->reloc_root != reloc_root);
2251 * set reference count to 1, so btrfs_recover_relocation
2252 * knows it should resumes merging
2255 btrfs_set_root_refs(&reloc_root->root_item, 1);
2256 btrfs_update_reloc_root(trans, root);
2258 list_add(&reloc_root->root_list, &reloc_roots);
2261 list_splice(&reloc_roots, &rc->reloc_roots);
2264 btrfs_commit_transaction(trans, rc->extent_root);
2266 btrfs_end_transaction(trans, rc->extent_root);
2270 static noinline_for_stack
2271 void free_reloc_roots(struct list_head *list)
2273 struct btrfs_root *reloc_root;
2275 while (!list_empty(list)) {
2276 reloc_root = list_entry(list->next, struct btrfs_root,
2278 __update_reloc_root(reloc_root, 1);
2279 free_extent_buffer(reloc_root->node);
2280 free_extent_buffer(reloc_root->commit_root);
2285 static noinline_for_stack
2286 int merge_reloc_roots(struct reloc_control *rc)
2288 struct btrfs_trans_handle *trans;
2289 struct btrfs_root *root;
2290 struct btrfs_root *reloc_root;
2294 LIST_HEAD(reloc_roots);
2298 root = rc->extent_root;
2301 * this serializes us with btrfs_record_root_in_transaction,
2302 * we have to make sure nobody is in the middle of
2303 * adding their roots to the list while we are
2306 mutex_lock(&root->fs_info->reloc_mutex);
2307 list_splice_init(&rc->reloc_roots, &reloc_roots);
2308 mutex_unlock(&root->fs_info->reloc_mutex);
2310 while (!list_empty(&reloc_roots)) {
2312 reloc_root = list_entry(reloc_roots.next,
2313 struct btrfs_root, root_list);
2315 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2316 root = read_fs_root(reloc_root->fs_info,
2317 reloc_root->root_key.offset);
2318 BUG_ON(IS_ERR(root));
2319 BUG_ON(root->reloc_root != reloc_root);
2321 ret = merge_reloc_root(rc, root);
2323 __update_reloc_root(reloc_root, 1);
2324 free_extent_buffer(reloc_root->node);
2325 free_extent_buffer(reloc_root->commit_root);
2330 list_del_init(&reloc_root->root_list);
2334 * we keep the old last snapshod transid in rtranid when we
2335 * created the relocation tree.
2337 last_snap = btrfs_root_rtransid(&reloc_root->root_item);
2338 otransid = btrfs_root_otransid(&reloc_root->root_item);
2339 objectid = reloc_root->root_key.offset;
2341 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2343 if (list_empty(&reloc_root->root_list))
2344 list_add_tail(&reloc_root->root_list,
2349 * recover the last snapshot tranid to avoid
2350 * the space balance break NOCOW.
2352 root = read_fs_root(rc->extent_root->fs_info,
2357 trans = btrfs_join_transaction(root);
2358 BUG_ON(IS_ERR(trans));
2360 /* Check if the fs/file tree was snapshoted or not. */
2361 if (btrfs_root_last_snapshot(&root->root_item) ==
2363 btrfs_set_root_last_snapshot(&root->root_item,
2366 btrfs_end_transaction(trans, root);
2376 btrfs_std_error(root->fs_info, ret);
2377 if (!list_empty(&reloc_roots))
2378 free_reloc_roots(&reloc_roots);
2381 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2385 static void free_block_list(struct rb_root *blocks)
2387 struct tree_block *block;
2388 struct rb_node *rb_node;
2389 while ((rb_node = rb_first(blocks))) {
2390 block = rb_entry(rb_node, struct tree_block, rb_node);
2391 rb_erase(rb_node, blocks);
2396 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2397 struct btrfs_root *reloc_root)
2399 struct btrfs_root *root;
2401 if (reloc_root->last_trans == trans->transid)
2404 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2405 BUG_ON(IS_ERR(root));
2406 BUG_ON(root->reloc_root != reloc_root);
2408 return btrfs_record_root_in_trans(trans, root);
2411 static noinline_for_stack
2412 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2413 struct reloc_control *rc,
2414 struct backref_node *node,
2415 struct backref_edge *edges[], int *nr)
2417 struct backref_node *next;
2418 struct btrfs_root *root;
2424 next = walk_up_backref(next, edges, &index);
2427 BUG_ON(!root->ref_cows);
2429 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2430 record_reloc_root_in_trans(trans, root);
2434 btrfs_record_root_in_trans(trans, root);
2435 root = root->reloc_root;
2437 if (next->new_bytenr != root->node->start) {
2438 BUG_ON(next->new_bytenr);
2439 BUG_ON(!list_empty(&next->list));
2440 next->new_bytenr = root->node->start;
2442 list_add_tail(&next->list,
2443 &rc->backref_cache.changed);
2444 __mark_block_processed(rc, next);
2450 next = walk_down_backref(edges, &index);
2451 if (!next || next->level <= node->level)
2459 /* setup backref node path for btrfs_reloc_cow_block */
2461 rc->backref_cache.path[next->level] = next;
2464 next = edges[index]->node[UPPER];
2470 * select a tree root for relocation. return NULL if the block
2471 * is reference counted. we should use do_relocation() in this
2472 * case. return a tree root pointer if the block isn't reference
2473 * counted. return -ENOENT if the block is root of reloc tree.
2475 static noinline_for_stack
2476 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2477 struct backref_node *node)
2479 struct backref_node *next;
2480 struct btrfs_root *root;
2481 struct btrfs_root *fs_root = NULL;
2482 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2488 next = walk_up_backref(next, edges, &index);
2492 /* no other choice for non-references counted tree */
2493 if (!root->ref_cows)
2496 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2502 next = walk_down_backref(edges, &index);
2503 if (!next || next->level <= node->level)
2508 return ERR_PTR(-ENOENT);
2512 static noinline_for_stack
2513 u64 calcu_metadata_size(struct reloc_control *rc,
2514 struct backref_node *node, int reserve)
2516 struct backref_node *next = node;
2517 struct backref_edge *edge;
2518 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2522 BUG_ON(reserve && node->processed);
2527 if (next->processed && (reserve || next != node))
2530 num_bytes += btrfs_level_size(rc->extent_root,
2533 if (list_empty(&next->upper))
2536 edge = list_entry(next->upper.next,
2537 struct backref_edge, list[LOWER]);
2538 edges[index++] = edge;
2539 next = edge->node[UPPER];
2541 next = walk_down_backref(edges, &index);
2546 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2547 struct reloc_control *rc,
2548 struct backref_node *node)
2550 struct btrfs_root *root = rc->extent_root;
2554 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2556 trans->block_rsv = rc->block_rsv;
2557 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2558 BTRFS_RESERVE_FLUSH_ALL);
2561 rc->commit_transaction = 1;
2568 static void release_metadata_space(struct reloc_control *rc,
2569 struct backref_node *node)
2571 u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2;
2572 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes);
2576 * relocate a block tree, and then update pointers in upper level
2577 * blocks that reference the block to point to the new location.
2579 * if called by link_to_upper, the block has already been relocated.
2580 * in that case this function just updates pointers.
2582 static int do_relocation(struct btrfs_trans_handle *trans,
2583 struct reloc_control *rc,
2584 struct backref_node *node,
2585 struct btrfs_key *key,
2586 struct btrfs_path *path, int lowest)
2588 struct backref_node *upper;
2589 struct backref_edge *edge;
2590 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2591 struct btrfs_root *root;
2592 struct extent_buffer *eb;
2601 BUG_ON(lowest && node->eb);
2603 path->lowest_level = node->level + 1;
2604 rc->backref_cache.path[node->level] = node;
2605 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2608 upper = edge->node[UPPER];
2609 root = select_reloc_root(trans, rc, upper, edges, &nr);
2612 if (upper->eb && !upper->locked) {
2614 ret = btrfs_bin_search(upper->eb, key,
2615 upper->level, &slot);
2617 bytenr = btrfs_node_blockptr(upper->eb, slot);
2618 if (node->eb->start == bytenr)
2621 drop_node_buffer(upper);
2625 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2633 upper->eb = path->nodes[upper->level];
2634 path->nodes[upper->level] = NULL;
2636 BUG_ON(upper->eb != path->nodes[upper->level]);
2640 path->locks[upper->level] = 0;
2642 slot = path->slots[upper->level];
2643 btrfs_release_path(path);
2645 ret = btrfs_bin_search(upper->eb, key, upper->level,
2650 bytenr = btrfs_node_blockptr(upper->eb, slot);
2652 BUG_ON(bytenr != node->bytenr);
2654 if (node->eb->start == bytenr)
2658 blocksize = btrfs_level_size(root, node->level);
2659 generation = btrfs_node_ptr_generation(upper->eb, slot);
2660 eb = read_tree_block(root, bytenr, blocksize, generation);
2661 if (!eb || !extent_buffer_uptodate(eb)) {
2662 free_extent_buffer(eb);
2666 btrfs_tree_lock(eb);
2667 btrfs_set_lock_blocking(eb);
2670 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2672 btrfs_tree_unlock(eb);
2673 free_extent_buffer(eb);
2678 BUG_ON(node->eb != eb);
2680 btrfs_set_node_blockptr(upper->eb, slot,
2682 btrfs_set_node_ptr_generation(upper->eb, slot,
2684 btrfs_mark_buffer_dirty(upper->eb);
2686 ret = btrfs_inc_extent_ref(trans, root,
2687 node->eb->start, blocksize,
2689 btrfs_header_owner(upper->eb),
2693 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2697 if (!upper->pending)
2698 drop_node_buffer(upper);
2700 unlock_node_buffer(upper);
2705 if (!err && node->pending) {
2706 drop_node_buffer(node);
2707 list_move_tail(&node->list, &rc->backref_cache.changed);
2711 path->lowest_level = 0;
2712 BUG_ON(err == -ENOSPC);
2716 static int link_to_upper(struct btrfs_trans_handle *trans,
2717 struct reloc_control *rc,
2718 struct backref_node *node,
2719 struct btrfs_path *path)
2721 struct btrfs_key key;
2723 btrfs_node_key_to_cpu(node->eb, &key, 0);
2724 return do_relocation(trans, rc, node, &key, path, 0);
2727 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2728 struct reloc_control *rc,
2729 struct btrfs_path *path, int err)
2732 struct backref_cache *cache = &rc->backref_cache;
2733 struct backref_node *node;
2737 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2738 while (!list_empty(&cache->pending[level])) {
2739 node = list_entry(cache->pending[level].next,
2740 struct backref_node, list);
2741 list_move_tail(&node->list, &list);
2742 BUG_ON(!node->pending);
2745 ret = link_to_upper(trans, rc, node, path);
2750 list_splice_init(&list, &cache->pending[level]);
2755 static void mark_block_processed(struct reloc_control *rc,
2756 u64 bytenr, u32 blocksize)
2758 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2759 EXTENT_DIRTY, GFP_NOFS);
2762 static void __mark_block_processed(struct reloc_control *rc,
2763 struct backref_node *node)
2766 if (node->level == 0 ||
2767 in_block_group(node->bytenr, rc->block_group)) {
2768 blocksize = btrfs_level_size(rc->extent_root, node->level);
2769 mark_block_processed(rc, node->bytenr, blocksize);
2771 node->processed = 1;
2775 * mark a block and all blocks directly/indirectly reference the block
2778 static void update_processed_blocks(struct reloc_control *rc,
2779 struct backref_node *node)
2781 struct backref_node *next = node;
2782 struct backref_edge *edge;
2783 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2789 if (next->processed)
2792 __mark_block_processed(rc, next);
2794 if (list_empty(&next->upper))
2797 edge = list_entry(next->upper.next,
2798 struct backref_edge, list[LOWER]);
2799 edges[index++] = edge;
2800 next = edge->node[UPPER];
2802 next = walk_down_backref(edges, &index);
2806 static int tree_block_processed(u64 bytenr, u32 blocksize,
2807 struct reloc_control *rc)
2809 if (test_range_bit(&rc->processed_blocks, bytenr,
2810 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2815 static int get_tree_block_key(struct reloc_control *rc,
2816 struct tree_block *block)
2818 struct extent_buffer *eb;
2820 BUG_ON(block->key_ready);
2821 eb = read_tree_block(rc->extent_root, block->bytenr,
2822 block->key.objectid, block->key.offset);
2823 if (!eb || !extent_buffer_uptodate(eb)) {
2824 free_extent_buffer(eb);
2827 WARN_ON(btrfs_header_level(eb) != block->level);
2828 if (block->level == 0)
2829 btrfs_item_key_to_cpu(eb, &block->key, 0);
2831 btrfs_node_key_to_cpu(eb, &block->key, 0);
2832 free_extent_buffer(eb);
2833 block->key_ready = 1;
2837 static int reada_tree_block(struct reloc_control *rc,
2838 struct tree_block *block)
2840 BUG_ON(block->key_ready);
2841 if (block->key.type == BTRFS_METADATA_ITEM_KEY)
2842 readahead_tree_block(rc->extent_root, block->bytenr,
2843 block->key.objectid,
2844 rc->extent_root->leafsize);
2846 readahead_tree_block(rc->extent_root, block->bytenr,
2847 block->key.objectid, block->key.offset);
2852 * helper function to relocate a tree block
2854 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2855 struct reloc_control *rc,
2856 struct backref_node *node,
2857 struct btrfs_key *key,
2858 struct btrfs_path *path)
2860 struct btrfs_root *root;
2867 BUG_ON(node->processed);
2868 root = select_one_root(trans, node);
2869 if (root == ERR_PTR(-ENOENT)) {
2870 update_processed_blocks(rc, node);
2874 if (!root || root->ref_cows) {
2875 ret = reserve_metadata_space(trans, rc, node);
2882 if (root->ref_cows) {
2883 BUG_ON(node->new_bytenr);
2884 BUG_ON(!list_empty(&node->list));
2885 btrfs_record_root_in_trans(trans, root);
2886 root = root->reloc_root;
2887 node->new_bytenr = root->node->start;
2889 list_add_tail(&node->list, &rc->backref_cache.changed);
2891 path->lowest_level = node->level;
2892 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2893 btrfs_release_path(path);
2898 update_processed_blocks(rc, node);
2900 ret = do_relocation(trans, rc, node, key, path, 1);
2903 if (ret || node->level == 0 || node->cowonly) {
2905 release_metadata_space(rc, node);
2906 remove_backref_node(&rc->backref_cache, node);
2912 * relocate a list of blocks
2914 static noinline_for_stack
2915 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2916 struct reloc_control *rc, struct rb_root *blocks)
2918 struct backref_node *node;
2919 struct btrfs_path *path;
2920 struct tree_block *block;
2921 struct rb_node *rb_node;
2925 path = btrfs_alloc_path();
2928 goto out_free_blocks;
2931 rb_node = rb_first(blocks);
2933 block = rb_entry(rb_node, struct tree_block, rb_node);
2934 if (!block->key_ready)
2935 reada_tree_block(rc, block);
2936 rb_node = rb_next(rb_node);
2939 rb_node = rb_first(blocks);
2941 block = rb_entry(rb_node, struct tree_block, rb_node);
2942 if (!block->key_ready) {
2943 err = get_tree_block_key(rc, block);
2947 rb_node = rb_next(rb_node);
2950 rb_node = rb_first(blocks);
2952 block = rb_entry(rb_node, struct tree_block, rb_node);
2954 node = build_backref_tree(rc, &block->key,
2955 block->level, block->bytenr);
2957 err = PTR_ERR(node);
2961 ret = relocate_tree_block(trans, rc, node, &block->key,
2964 if (ret != -EAGAIN || rb_node == rb_first(blocks))
2968 rb_node = rb_next(rb_node);
2971 err = finish_pending_nodes(trans, rc, path, err);
2974 btrfs_free_path(path);
2976 free_block_list(blocks);
2980 static noinline_for_stack
2981 int prealloc_file_extent_cluster(struct inode *inode,
2982 struct file_extent_cluster *cluster)
2987 u64 offset = BTRFS_I(inode)->index_cnt;
2992 BUG_ON(cluster->start != cluster->boundary[0]);
2993 mutex_lock(&inode->i_mutex);
2995 ret = btrfs_check_data_free_space(inode, cluster->end +
2996 1 - cluster->start);
3000 while (nr < cluster->nr) {
3001 start = cluster->boundary[nr] - offset;
3002 if (nr + 1 < cluster->nr)
3003 end = cluster->boundary[nr + 1] - 1 - offset;
3005 end = cluster->end - offset;
3007 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3008 num_bytes = end + 1 - start;
3009 ret = btrfs_prealloc_file_range(inode, 0, start,
3010 num_bytes, num_bytes,
3011 end + 1, &alloc_hint);
3012 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3017 btrfs_free_reserved_data_space(inode, cluster->end +
3018 1 - cluster->start);
3020 mutex_unlock(&inode->i_mutex);
3024 static noinline_for_stack
3025 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3028 struct btrfs_root *root = BTRFS_I(inode)->root;
3029 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3030 struct extent_map *em;
3033 em = alloc_extent_map();
3038 em->len = end + 1 - start;
3039 em->block_len = em->len;
3040 em->block_start = block_start;
3041 em->bdev = root->fs_info->fs_devices->latest_bdev;
3042 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3044 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3046 write_lock(&em_tree->lock);
3047 ret = add_extent_mapping(em_tree, em, 0);
3048 write_unlock(&em_tree->lock);
3049 if (ret != -EEXIST) {
3050 free_extent_map(em);
3053 btrfs_drop_extent_cache(inode, start, end, 0);
3055 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3059 static int relocate_file_extent_cluster(struct inode *inode,
3060 struct file_extent_cluster *cluster)
3064 u64 offset = BTRFS_I(inode)->index_cnt;
3065 unsigned long index;
3066 unsigned long last_index;
3068 struct file_ra_state *ra;
3069 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3076 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3080 ret = prealloc_file_extent_cluster(inode, cluster);
3084 file_ra_state_init(ra, inode->i_mapping);
3086 ret = setup_extent_mapping(inode, cluster->start - offset,
3087 cluster->end - offset, cluster->start);
3091 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
3092 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
3093 while (index <= last_index) {
3094 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
3098 page = find_lock_page(inode->i_mapping, index);
3100 page_cache_sync_readahead(inode->i_mapping,
3102 last_index + 1 - index);
3103 page = find_or_create_page(inode->i_mapping, index,
3106 btrfs_delalloc_release_metadata(inode,
3113 if (PageReadahead(page)) {
3114 page_cache_async_readahead(inode->i_mapping,
3115 ra, NULL, page, index,
3116 last_index + 1 - index);
3119 if (!PageUptodate(page)) {
3120 btrfs_readpage(NULL, page);
3122 if (!PageUptodate(page)) {
3124 page_cache_release(page);
3125 btrfs_delalloc_release_metadata(inode,
3132 page_start = page_offset(page);
3133 page_end = page_start + PAGE_CACHE_SIZE - 1;
3135 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3137 set_page_extent_mapped(page);
3139 if (nr < cluster->nr &&
3140 page_start + offset == cluster->boundary[nr]) {
3141 set_extent_bits(&BTRFS_I(inode)->io_tree,
3142 page_start, page_end,
3143 EXTENT_BOUNDARY, GFP_NOFS);
3147 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3148 set_page_dirty(page);
3150 unlock_extent(&BTRFS_I(inode)->io_tree,
3151 page_start, page_end);
3153 page_cache_release(page);
3156 balance_dirty_pages_ratelimited(inode->i_mapping);
3157 btrfs_throttle(BTRFS_I(inode)->root);
3159 WARN_ON(nr != cluster->nr);
3165 static noinline_for_stack
3166 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3167 struct file_extent_cluster *cluster)
3171 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3172 ret = relocate_file_extent_cluster(inode, cluster);
3179 cluster->start = extent_key->objectid;
3181 BUG_ON(cluster->nr >= MAX_EXTENTS);
3182 cluster->end = extent_key->objectid + extent_key->offset - 1;
3183 cluster->boundary[cluster->nr] = extent_key->objectid;
3186 if (cluster->nr >= MAX_EXTENTS) {
3187 ret = relocate_file_extent_cluster(inode, cluster);
3195 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3196 static int get_ref_objectid_v0(struct reloc_control *rc,
3197 struct btrfs_path *path,
3198 struct btrfs_key *extent_key,
3199 u64 *ref_objectid, int *path_change)
3201 struct btrfs_key key;
3202 struct extent_buffer *leaf;
3203 struct btrfs_extent_ref_v0 *ref0;
3207 leaf = path->nodes[0];
3208 slot = path->slots[0];
3210 if (slot >= btrfs_header_nritems(leaf)) {
3211 ret = btrfs_next_leaf(rc->extent_root, path);
3215 leaf = path->nodes[0];
3216 slot = path->slots[0];
3220 btrfs_item_key_to_cpu(leaf, &key, slot);
3221 if (key.objectid != extent_key->objectid)
3224 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3228 ref0 = btrfs_item_ptr(leaf, slot,
3229 struct btrfs_extent_ref_v0);
3230 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3238 * helper to add a tree block to the list.
3239 * the major work is getting the generation and level of the block
3241 static int add_tree_block(struct reloc_control *rc,
3242 struct btrfs_key *extent_key,
3243 struct btrfs_path *path,
3244 struct rb_root *blocks)
3246 struct extent_buffer *eb;
3247 struct btrfs_extent_item *ei;
3248 struct btrfs_tree_block_info *bi;
3249 struct tree_block *block;
3250 struct rb_node *rb_node;
3255 eb = path->nodes[0];
3256 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3258 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3259 item_size >= sizeof(*ei) + sizeof(*bi)) {
3260 ei = btrfs_item_ptr(eb, path->slots[0],
3261 struct btrfs_extent_item);
3262 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3263 bi = (struct btrfs_tree_block_info *)(ei + 1);
3264 level = btrfs_tree_block_level(eb, bi);
3266 level = (int)extent_key->offset;
3268 generation = btrfs_extent_generation(eb, ei);
3270 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3274 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3275 ret = get_ref_objectid_v0(rc, path, extent_key,
3279 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3280 level = (int)ref_owner;
3281 /* FIXME: get real generation */
3288 btrfs_release_path(path);
3290 BUG_ON(level == -1);
3292 block = kmalloc(sizeof(*block), GFP_NOFS);
3296 block->bytenr = extent_key->objectid;
3297 block->key.objectid = rc->extent_root->leafsize;
3298 block->key.offset = generation;
3299 block->level = level;
3300 block->key_ready = 0;
3302 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3304 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3310 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3312 static int __add_tree_block(struct reloc_control *rc,
3313 u64 bytenr, u32 blocksize,
3314 struct rb_root *blocks)
3316 struct btrfs_path *path;
3317 struct btrfs_key key;
3319 bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
3322 if (tree_block_processed(bytenr, blocksize, rc))
3325 if (tree_search(blocks, bytenr))
3328 path = btrfs_alloc_path();
3332 key.objectid = bytenr;
3334 key.type = BTRFS_METADATA_ITEM_KEY;
3335 key.offset = (u64)-1;
3337 key.type = BTRFS_EXTENT_ITEM_KEY;
3338 key.offset = blocksize;
3341 path->search_commit_root = 1;
3342 path->skip_locking = 1;
3343 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3347 if (ret > 0 && skinny) {
3348 if (path->slots[0]) {
3350 btrfs_item_key_to_cpu(path->nodes[0], &key,
3352 if (key.objectid == bytenr &&
3353 (key.type == BTRFS_METADATA_ITEM_KEY ||
3354 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3355 key.offset == blocksize)))
3361 btrfs_release_path(path);
3367 ret = add_tree_block(rc, &key, path, blocks);
3369 btrfs_free_path(path);
3374 * helper to check if the block use full backrefs for pointers in it
3376 static int block_use_full_backref(struct reloc_control *rc,
3377 struct extent_buffer *eb)
3382 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3383 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3386 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3387 eb->start, btrfs_header_level(eb), 1,
3391 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3398 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3399 struct inode *inode, u64 ino)
3401 struct btrfs_key key;
3402 struct btrfs_path *path;
3403 struct btrfs_root *root = fs_info->tree_root;
3404 struct btrfs_trans_handle *trans;
3411 key.type = BTRFS_INODE_ITEM_KEY;
3414 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3415 if (IS_ERR(inode) || is_bad_inode(inode)) {
3422 ret = btrfs_check_trunc_cache_free_space(root,
3423 &fs_info->global_block_rsv);
3427 path = btrfs_alloc_path();
3433 trans = btrfs_join_transaction(root);
3434 if (IS_ERR(trans)) {
3435 btrfs_free_path(path);
3436 ret = PTR_ERR(trans);
3440 ret = btrfs_truncate_free_space_cache(root, trans, path, inode);
3442 btrfs_free_path(path);
3443 btrfs_end_transaction(trans, root);
3444 btrfs_btree_balance_dirty(root);
3451 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3452 * this function scans fs tree to find blocks reference the data extent
3454 static int find_data_references(struct reloc_control *rc,
3455 struct btrfs_key *extent_key,
3456 struct extent_buffer *leaf,
3457 struct btrfs_extent_data_ref *ref,
3458 struct rb_root *blocks)
3460 struct btrfs_path *path;
3461 struct tree_block *block;
3462 struct btrfs_root *root;
3463 struct btrfs_file_extent_item *fi;
3464 struct rb_node *rb_node;
3465 struct btrfs_key key;
3476 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3477 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3478 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3479 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3482 * This is an extent belonging to the free space cache, lets just delete
3483 * it and redo the search.
3485 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3486 ret = delete_block_group_cache(rc->extent_root->fs_info,
3487 NULL, ref_objectid);
3493 path = btrfs_alloc_path();
3498 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3500 err = PTR_ERR(root);
3504 key.objectid = ref_objectid;
3505 key.type = BTRFS_EXTENT_DATA_KEY;
3506 if (ref_offset > ((u64)-1 << 32))
3509 key.offset = ref_offset;
3511 path->search_commit_root = 1;
3512 path->skip_locking = 1;
3513 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3519 leaf = path->nodes[0];
3520 nritems = btrfs_header_nritems(leaf);
3522 * the references in tree blocks that use full backrefs
3523 * are not counted in
3525 if (block_use_full_backref(rc, leaf))
3529 rb_node = tree_search(blocks, leaf->start);
3534 path->slots[0] = nritems;
3537 while (ref_count > 0) {
3538 while (path->slots[0] >= nritems) {
3539 ret = btrfs_next_leaf(root, path);
3549 leaf = path->nodes[0];
3550 nritems = btrfs_header_nritems(leaf);
3553 if (block_use_full_backref(rc, leaf))
3557 rb_node = tree_search(blocks, leaf->start);
3562 path->slots[0] = nritems;
3566 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3567 if (key.objectid != ref_objectid ||
3568 key.type != BTRFS_EXTENT_DATA_KEY) {
3573 fi = btrfs_item_ptr(leaf, path->slots[0],
3574 struct btrfs_file_extent_item);
3576 if (btrfs_file_extent_type(leaf, fi) ==
3577 BTRFS_FILE_EXTENT_INLINE)
3580 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3581 extent_key->objectid)
3584 key.offset -= btrfs_file_extent_offset(leaf, fi);
3585 if (key.offset != ref_offset)
3593 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3594 block = kmalloc(sizeof(*block), GFP_NOFS);
3599 block->bytenr = leaf->start;
3600 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3602 block->key_ready = 1;
3603 rb_node = tree_insert(blocks, block->bytenr,
3606 backref_tree_panic(rb_node, -EEXIST,
3612 path->slots[0] = nritems;
3618 btrfs_free_path(path);
3623 * helper to find all tree blocks that reference a given data extent
3625 static noinline_for_stack
3626 int add_data_references(struct reloc_control *rc,
3627 struct btrfs_key *extent_key,
3628 struct btrfs_path *path,
3629 struct rb_root *blocks)
3631 struct btrfs_key key;
3632 struct extent_buffer *eb;
3633 struct btrfs_extent_data_ref *dref;
3634 struct btrfs_extent_inline_ref *iref;
3637 u32 blocksize = btrfs_level_size(rc->extent_root, 0);
3641 eb = path->nodes[0];
3642 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3643 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3644 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3645 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3649 ptr += sizeof(struct btrfs_extent_item);
3652 iref = (struct btrfs_extent_inline_ref *)ptr;
3653 key.type = btrfs_extent_inline_ref_type(eb, iref);
3654 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3655 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3656 ret = __add_tree_block(rc, key.offset, blocksize,
3658 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3659 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3660 ret = find_data_references(rc, extent_key,
3669 ptr += btrfs_extent_inline_ref_size(key.type);
3675 eb = path->nodes[0];
3676 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3677 ret = btrfs_next_leaf(rc->extent_root, path);
3684 eb = path->nodes[0];
3687 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3688 if (key.objectid != extent_key->objectid)
3691 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3692 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3693 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3695 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3696 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3698 ret = __add_tree_block(rc, key.offset, blocksize,
3700 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3701 dref = btrfs_item_ptr(eb, path->slots[0],
3702 struct btrfs_extent_data_ref);
3703 ret = find_data_references(rc, extent_key,
3715 btrfs_release_path(path);
3717 free_block_list(blocks);
3722 * helper to find next unprocessed extent
3724 static noinline_for_stack
3725 int find_next_extent(struct btrfs_trans_handle *trans,
3726 struct reloc_control *rc, struct btrfs_path *path,
3727 struct btrfs_key *extent_key)
3729 struct btrfs_key key;
3730 struct extent_buffer *leaf;
3731 u64 start, end, last;
3734 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3737 if (rc->search_start >= last) {
3742 key.objectid = rc->search_start;
3743 key.type = BTRFS_EXTENT_ITEM_KEY;
3746 path->search_commit_root = 1;
3747 path->skip_locking = 1;
3748 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3753 leaf = path->nodes[0];
3754 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3755 ret = btrfs_next_leaf(rc->extent_root, path);
3758 leaf = path->nodes[0];
3761 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3762 if (key.objectid >= last) {
3767 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3768 key.type != BTRFS_METADATA_ITEM_KEY) {
3773 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3774 key.objectid + key.offset <= rc->search_start) {
3779 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3780 key.objectid + rc->extent_root->leafsize <=
3786 ret = find_first_extent_bit(&rc->processed_blocks,
3787 key.objectid, &start, &end,
3788 EXTENT_DIRTY, NULL);
3790 if (ret == 0 && start <= key.objectid) {
3791 btrfs_release_path(path);
3792 rc->search_start = end + 1;
3794 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3795 rc->search_start = key.objectid + key.offset;
3797 rc->search_start = key.objectid +
3798 rc->extent_root->leafsize;
3799 memcpy(extent_key, &key, sizeof(key));
3803 btrfs_release_path(path);
3807 static void set_reloc_control(struct reloc_control *rc)
3809 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3811 mutex_lock(&fs_info->reloc_mutex);
3812 fs_info->reloc_ctl = rc;
3813 mutex_unlock(&fs_info->reloc_mutex);
3816 static void unset_reloc_control(struct reloc_control *rc)
3818 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3820 mutex_lock(&fs_info->reloc_mutex);
3821 fs_info->reloc_ctl = NULL;
3822 mutex_unlock(&fs_info->reloc_mutex);
3825 static int check_extent_flags(u64 flags)
3827 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3828 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3830 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3831 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3833 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3834 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3839 static noinline_for_stack
3840 int prepare_to_relocate(struct reloc_control *rc)
3842 struct btrfs_trans_handle *trans;
3845 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3846 BTRFS_BLOCK_RSV_TEMP);
3851 * reserve some space for creating reloc trees.
3852 * btrfs_init_reloc_root will use them when there
3853 * is no reservation in transaction handle.
3855 ret = btrfs_block_rsv_add(rc->extent_root, rc->block_rsv,
3856 rc->extent_root->nodesize * 256,
3857 BTRFS_RESERVE_FLUSH_ALL);
3861 memset(&rc->cluster, 0, sizeof(rc->cluster));
3862 rc->search_start = rc->block_group->key.objectid;
3863 rc->extents_found = 0;
3864 rc->nodes_relocated = 0;
3865 rc->merging_rsv_size = 0;
3867 rc->create_reloc_tree = 1;
3868 set_reloc_control(rc);
3870 trans = btrfs_join_transaction(rc->extent_root);
3871 if (IS_ERR(trans)) {
3872 unset_reloc_control(rc);
3874 * extent tree is not a ref_cow tree and has no reloc_root to
3875 * cleanup. And callers are responsible to free the above
3878 return PTR_ERR(trans);
3880 btrfs_commit_transaction(trans, rc->extent_root);
3884 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3886 struct rb_root blocks = RB_ROOT;
3887 struct btrfs_key key;
3888 struct btrfs_trans_handle *trans = NULL;
3889 struct btrfs_path *path;
3890 struct btrfs_extent_item *ei;
3897 path = btrfs_alloc_path();
3902 ret = prepare_to_relocate(rc);
3910 trans = btrfs_start_transaction(rc->extent_root, 0);
3911 if (IS_ERR(trans)) {
3912 err = PTR_ERR(trans);
3917 if (update_backref_cache(trans, &rc->backref_cache)) {
3918 btrfs_end_transaction(trans, rc->extent_root);
3922 ret = find_next_extent(trans, rc, path, &key);
3928 rc->extents_found++;
3930 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3931 struct btrfs_extent_item);
3932 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3933 if (item_size >= sizeof(*ei)) {
3934 flags = btrfs_extent_flags(path->nodes[0], ei);
3935 ret = check_extent_flags(flags);
3939 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3941 int path_change = 0;
3944 sizeof(struct btrfs_extent_item_v0));
3945 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3947 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3948 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3950 flags = BTRFS_EXTENT_FLAG_DATA;
3953 btrfs_release_path(path);
3955 path->search_commit_root = 1;
3956 path->skip_locking = 1;
3957 ret = btrfs_search_slot(NULL, rc->extent_root,
3970 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3971 ret = add_tree_block(rc, &key, path, &blocks);
3972 } else if (rc->stage == UPDATE_DATA_PTRS &&
3973 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3974 ret = add_data_references(rc, &key, path, &blocks);
3976 btrfs_release_path(path);
3984 if (!RB_EMPTY_ROOT(&blocks)) {
3985 ret = relocate_tree_blocks(trans, rc, &blocks);
3987 if (ret != -EAGAIN) {
3991 rc->extents_found--;
3992 rc->search_start = key.objectid;
3996 ret = btrfs_block_rsv_check(rc->extent_root, rc->block_rsv, 5);
3998 if (ret != -ENOSPC) {
4003 rc->commit_transaction = 1;
4006 if (rc->commit_transaction) {
4007 rc->commit_transaction = 0;
4008 ret = btrfs_commit_transaction(trans, rc->extent_root);
4011 btrfs_end_transaction_throttle(trans, rc->extent_root);
4012 btrfs_btree_balance_dirty(rc->extent_root);
4016 if (rc->stage == MOVE_DATA_EXTENTS &&
4017 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4018 rc->found_file_extent = 1;
4019 ret = relocate_data_extent(rc->data_inode,
4020 &key, &rc->cluster);
4027 if (trans && progress && err == -ENOSPC) {
4028 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
4029 rc->block_group->flags);
4037 btrfs_release_path(path);
4038 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
4042 btrfs_end_transaction_throttle(trans, rc->extent_root);
4043 btrfs_btree_balance_dirty(rc->extent_root);
4047 ret = relocate_file_extent_cluster(rc->data_inode,
4053 rc->create_reloc_tree = 0;
4054 set_reloc_control(rc);
4056 backref_cache_cleanup(&rc->backref_cache);
4057 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4059 err = prepare_to_merge(rc, err);
4061 merge_reloc_roots(rc);
4063 rc->merge_reloc_tree = 0;
4064 unset_reloc_control(rc);
4065 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4067 /* get rid of pinned extents */
4068 trans = btrfs_join_transaction(rc->extent_root);
4070 err = PTR_ERR(trans);
4072 btrfs_commit_transaction(trans, rc->extent_root);
4074 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4075 btrfs_free_path(path);
4079 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4080 struct btrfs_root *root, u64 objectid)
4082 struct btrfs_path *path;
4083 struct btrfs_inode_item *item;
4084 struct extent_buffer *leaf;
4087 path = btrfs_alloc_path();
4091 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4095 leaf = path->nodes[0];
4096 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4097 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4098 btrfs_set_inode_generation(leaf, item, 1);
4099 btrfs_set_inode_size(leaf, item, 0);
4100 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4101 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4102 BTRFS_INODE_PREALLOC);
4103 btrfs_mark_buffer_dirty(leaf);
4104 btrfs_release_path(path);
4106 btrfs_free_path(path);
4111 * helper to create inode for data relocation.
4112 * the inode is in data relocation tree and its link count is 0
4114 static noinline_for_stack
4115 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4116 struct btrfs_block_group_cache *group)
4118 struct inode *inode = NULL;
4119 struct btrfs_trans_handle *trans;
4120 struct btrfs_root *root;
4121 struct btrfs_key key;
4122 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4125 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4127 return ERR_CAST(root);
4129 trans = btrfs_start_transaction(root, 6);
4131 return ERR_CAST(trans);
4133 err = btrfs_find_free_objectid(root, &objectid);
4137 err = __insert_orphan_inode(trans, root, objectid);
4140 key.objectid = objectid;
4141 key.type = BTRFS_INODE_ITEM_KEY;
4143 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4144 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4145 BTRFS_I(inode)->index_cnt = group->key.objectid;
4147 err = btrfs_orphan_add(trans, inode);
4149 btrfs_end_transaction(trans, root);
4150 btrfs_btree_balance_dirty(root);
4154 inode = ERR_PTR(err);
4159 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4161 struct reloc_control *rc;
4163 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4167 INIT_LIST_HEAD(&rc->reloc_roots);
4168 backref_cache_init(&rc->backref_cache);
4169 mapping_tree_init(&rc->reloc_root_tree);
4170 extent_io_tree_init(&rc->processed_blocks,
4171 fs_info->btree_inode->i_mapping);
4176 * function to relocate all extents in a block group.
4178 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4180 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4181 struct reloc_control *rc;
4182 struct inode *inode;
4183 struct btrfs_path *path;
4188 rc = alloc_reloc_control(fs_info);
4192 rc->extent_root = extent_root;
4194 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4195 BUG_ON(!rc->block_group);
4197 if (!rc->block_group->ro) {
4198 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
4206 path = btrfs_alloc_path();
4212 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4214 btrfs_free_path(path);
4217 ret = delete_block_group_cache(fs_info, inode, 0);
4219 ret = PTR_ERR(inode);
4221 if (ret && ret != -ENOENT) {
4226 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4227 if (IS_ERR(rc->data_inode)) {
4228 err = PTR_ERR(rc->data_inode);
4229 rc->data_inode = NULL;
4233 printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n",
4234 rc->block_group->key.objectid, rc->block_group->flags);
4236 ret = btrfs_start_all_delalloc_inodes(fs_info, 0);
4241 btrfs_wait_all_ordered_extents(fs_info, 0);
4244 mutex_lock(&fs_info->cleaner_mutex);
4245 ret = relocate_block_group(rc);
4246 mutex_unlock(&fs_info->cleaner_mutex);
4252 if (rc->extents_found == 0)
4255 printk(KERN_INFO "btrfs: found %llu extents\n",
4258 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4259 btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1);
4260 invalidate_mapping_pages(rc->data_inode->i_mapping,
4262 rc->stage = UPDATE_DATA_PTRS;
4266 filemap_write_and_wait_range(fs_info->btree_inode->i_mapping,
4267 rc->block_group->key.objectid,
4268 rc->block_group->key.objectid +
4269 rc->block_group->key.offset - 1);
4271 WARN_ON(rc->block_group->pinned > 0);
4272 WARN_ON(rc->block_group->reserved > 0);
4273 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4276 btrfs_set_block_group_rw(extent_root, rc->block_group);
4277 iput(rc->data_inode);
4278 btrfs_put_block_group(rc->block_group);
4283 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4285 struct btrfs_trans_handle *trans;
4288 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4290 return PTR_ERR(trans);
4292 memset(&root->root_item.drop_progress, 0,
4293 sizeof(root->root_item.drop_progress));
4294 root->root_item.drop_level = 0;
4295 btrfs_set_root_refs(&root->root_item, 0);
4296 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4297 &root->root_key, &root->root_item);
4299 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4306 * recover relocation interrupted by system crash.
4308 * this function resumes merging reloc trees with corresponding fs trees.
4309 * this is important for keeping the sharing of tree blocks
4311 int btrfs_recover_relocation(struct btrfs_root *root)
4313 LIST_HEAD(reloc_roots);
4314 struct btrfs_key key;
4315 struct btrfs_root *fs_root;
4316 struct btrfs_root *reloc_root;
4317 struct btrfs_path *path;
4318 struct extent_buffer *leaf;
4319 struct reloc_control *rc = NULL;
4320 struct btrfs_trans_handle *trans;
4324 path = btrfs_alloc_path();
4329 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4330 key.type = BTRFS_ROOT_ITEM_KEY;
4331 key.offset = (u64)-1;
4334 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4341 if (path->slots[0] == 0)
4345 leaf = path->nodes[0];
4346 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4347 btrfs_release_path(path);
4349 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4350 key.type != BTRFS_ROOT_ITEM_KEY)
4353 reloc_root = btrfs_read_fs_root(root, &key);
4354 if (IS_ERR(reloc_root)) {
4355 err = PTR_ERR(reloc_root);
4359 list_add(&reloc_root->root_list, &reloc_roots);
4361 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4362 fs_root = read_fs_root(root->fs_info,
4363 reloc_root->root_key.offset);
4364 if (IS_ERR(fs_root)) {
4365 ret = PTR_ERR(fs_root);
4366 if (ret != -ENOENT) {
4370 ret = mark_garbage_root(reloc_root);
4378 if (key.offset == 0)
4383 btrfs_release_path(path);
4385 if (list_empty(&reloc_roots))
4388 rc = alloc_reloc_control(root->fs_info);
4394 rc->extent_root = root->fs_info->extent_root;
4396 set_reloc_control(rc);
4398 trans = btrfs_join_transaction(rc->extent_root);
4399 if (IS_ERR(trans)) {
4400 unset_reloc_control(rc);
4401 err = PTR_ERR(trans);
4405 rc->merge_reloc_tree = 1;
4407 while (!list_empty(&reloc_roots)) {
4408 reloc_root = list_entry(reloc_roots.next,
4409 struct btrfs_root, root_list);
4410 list_del(&reloc_root->root_list);
4412 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4413 list_add_tail(&reloc_root->root_list,
4418 fs_root = read_fs_root(root->fs_info,
4419 reloc_root->root_key.offset);
4420 if (IS_ERR(fs_root)) {
4421 err = PTR_ERR(fs_root);
4425 err = __add_reloc_root(reloc_root);
4426 BUG_ON(err < 0); /* -ENOMEM or logic error */
4427 fs_root->reloc_root = reloc_root;
4430 err = btrfs_commit_transaction(trans, rc->extent_root);
4434 merge_reloc_roots(rc);
4436 unset_reloc_control(rc);
4438 trans = btrfs_join_transaction(rc->extent_root);
4440 err = PTR_ERR(trans);
4442 err = btrfs_commit_transaction(trans, rc->extent_root);
4446 if (!list_empty(&reloc_roots))
4447 free_reloc_roots(&reloc_roots);
4449 btrfs_free_path(path);
4452 /* cleanup orphan inode in data relocation tree */
4453 fs_root = read_fs_root(root->fs_info,
4454 BTRFS_DATA_RELOC_TREE_OBJECTID);
4455 if (IS_ERR(fs_root))
4456 err = PTR_ERR(fs_root);
4458 err = btrfs_orphan_cleanup(fs_root);
4464 * helper to add ordered checksum for data relocation.
4466 * cloning checksum properly handles the nodatasum extents.
4467 * it also saves CPU time to re-calculate the checksum.
4469 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4471 struct btrfs_ordered_sum *sums;
4472 struct btrfs_ordered_extent *ordered;
4473 struct btrfs_root *root = BTRFS_I(inode)->root;
4478 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4479 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4481 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4482 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4483 disk_bytenr + len - 1, &list, 0);
4487 disk_bytenr = ordered->start;
4488 while (!list_empty(&list)) {
4489 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4490 list_del_init(&sums->list);
4492 sums->bytenr = disk_bytenr;
4493 disk_bytenr += sums->len;
4495 btrfs_add_ordered_sum(inode, ordered, sums);
4498 btrfs_put_ordered_extent(ordered);
4502 void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4503 struct btrfs_root *root, struct extent_buffer *buf,
4504 struct extent_buffer *cow)
4506 struct reloc_control *rc;
4507 struct backref_node *node;
4512 rc = root->fs_info->reloc_ctl;
4516 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4517 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4519 level = btrfs_header_level(buf);
4520 if (btrfs_header_generation(buf) <=
4521 btrfs_root_last_snapshot(&root->root_item))
4524 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4525 rc->create_reloc_tree) {
4526 WARN_ON(!first_cow && level == 0);
4528 node = rc->backref_cache.path[level];
4529 BUG_ON(node->bytenr != buf->start &&
4530 node->new_bytenr != buf->start);
4532 drop_node_buffer(node);
4533 extent_buffer_get(cow);
4535 node->new_bytenr = cow->start;
4537 if (!node->pending) {
4538 list_move_tail(&node->list,
4539 &rc->backref_cache.pending[level]);
4544 __mark_block_processed(rc, node);
4546 if (first_cow && level > 0)
4547 rc->nodes_relocated += buf->len;
4550 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) {
4551 ret = replace_file_extents(trans, rc, root, cow);
4557 * called before creating snapshot. it calculates metadata reservation
4558 * requried for relocating tree blocks in the snapshot
4560 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4561 struct btrfs_pending_snapshot *pending,
4562 u64 *bytes_to_reserve)
4564 struct btrfs_root *root;
4565 struct reloc_control *rc;
4567 root = pending->root;
4568 if (!root->reloc_root)
4571 rc = root->fs_info->reloc_ctl;
4572 if (!rc->merge_reloc_tree)
4575 root = root->reloc_root;
4576 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4578 * relocation is in the stage of merging trees. the space
4579 * used by merging a reloc tree is twice the size of
4580 * relocated tree nodes in the worst case. half for cowing
4581 * the reloc tree, half for cowing the fs tree. the space
4582 * used by cowing the reloc tree will be freed after the
4583 * tree is dropped. if we create snapshot, cowing the fs
4584 * tree may use more space than it frees. so we need
4585 * reserve extra space.
4587 *bytes_to_reserve += rc->nodes_relocated;
4591 * called after snapshot is created. migrate block reservation
4592 * and create reloc root for the newly created snapshot
4594 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4595 struct btrfs_pending_snapshot *pending)
4597 struct btrfs_root *root = pending->root;
4598 struct btrfs_root *reloc_root;
4599 struct btrfs_root *new_root;
4600 struct reloc_control *rc;
4603 if (!root->reloc_root)
4606 rc = root->fs_info->reloc_ctl;
4607 rc->merging_rsv_size += rc->nodes_relocated;
4609 if (rc->merge_reloc_tree) {
4610 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4612 rc->nodes_relocated);
4617 new_root = pending->snap;
4618 reloc_root = create_reloc_root(trans, root->reloc_root,
4619 new_root->root_key.objectid);
4620 if (IS_ERR(reloc_root))
4621 return PTR_ERR(reloc_root);
4623 ret = __add_reloc_root(reloc_root);
4625 new_root->reloc_root = reloc_root;
4627 if (rc->create_reloc_tree)
4628 ret = clone_backref_node(trans, rc, root, reloc_root);