2 * Copyright (C) 2009 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
27 #include "transaction.h"
30 #include "btrfs_inode.h"
31 #include "async-thread.h"
32 #include "free-space-cache.h"
33 #include "inode-map.h"
37 * backref_node, mapping_node and tree_block start with this
40 struct rb_node rb_node;
45 * present a tree block in the backref cache
48 struct rb_node rb_node;
52 /* objectid of tree block owner, can be not uptodate */
54 /* link to pending, changed or detached list */
55 struct list_head list;
56 /* list of upper level blocks reference this block */
57 struct list_head upper;
58 /* list of child blocks in the cache */
59 struct list_head lower;
60 /* NULL if this node is not tree root */
61 struct btrfs_root *root;
62 /* extent buffer got by COW the block */
63 struct extent_buffer *eb;
64 /* level of tree block */
66 /* is the block in non-reference counted tree */
67 unsigned int cowonly:1;
68 /* 1 if no child node in the cache */
69 unsigned int lowest:1;
70 /* is the extent buffer locked */
71 unsigned int locked:1;
72 /* has the block been processed */
73 unsigned int processed:1;
74 /* have backrefs of this block been checked */
75 unsigned int checked:1;
77 * 1 if corresponding block has been cowed but some upper
78 * level block pointers may not point to the new location
80 unsigned int pending:1;
82 * 1 if the backref node isn't connected to any other
85 unsigned int detached:1;
89 * present a block pointer in the backref cache
92 struct list_head list[2];
93 struct backref_node *node[2];
98 #define RELOCATION_RESERVED_NODES 256
100 struct backref_cache {
101 /* red black tree of all backref nodes in the cache */
102 struct rb_root rb_root;
103 /* for passing backref nodes to btrfs_reloc_cow_block */
104 struct backref_node *path[BTRFS_MAX_LEVEL];
106 * list of blocks that have been cowed but some block
107 * pointers in upper level blocks may not reflect the
110 struct list_head pending[BTRFS_MAX_LEVEL];
111 /* list of backref nodes with no child node */
112 struct list_head leaves;
113 /* list of blocks that have been cowed in current transaction */
114 struct list_head changed;
115 /* list of detached backref node. */
116 struct list_head detached;
125 * map address of tree root to tree
127 struct mapping_node {
128 struct rb_node rb_node;
133 struct mapping_tree {
134 struct rb_root rb_root;
139 * present a tree block to process
142 struct rb_node rb_node;
144 struct btrfs_key key;
145 unsigned int level:8;
146 unsigned int key_ready:1;
149 #define MAX_EXTENTS 128
151 struct file_extent_cluster {
154 u64 boundary[MAX_EXTENTS];
158 struct reloc_control {
159 /* block group to relocate */
160 struct btrfs_block_group_cache *block_group;
162 struct btrfs_root *extent_root;
163 /* inode for moving data */
164 struct inode *data_inode;
166 struct btrfs_block_rsv *block_rsv;
168 struct backref_cache backref_cache;
170 struct file_extent_cluster cluster;
171 /* tree blocks have been processed */
172 struct extent_io_tree processed_blocks;
173 /* map start of tree root to corresponding reloc tree */
174 struct mapping_tree reloc_root_tree;
175 /* list of reloc trees */
176 struct list_head reloc_roots;
177 /* size of metadata reservation for merging reloc trees */
178 u64 merging_rsv_size;
179 /* size of relocated tree nodes */
181 /* reserved size for block group relocation*/
187 unsigned int stage:8;
188 unsigned int create_reloc_tree:1;
189 unsigned int merge_reloc_tree:1;
190 unsigned int found_file_extent:1;
193 /* stages of data relocation */
194 #define MOVE_DATA_EXTENTS 0
195 #define UPDATE_DATA_PTRS 1
197 static void remove_backref_node(struct backref_cache *cache,
198 struct backref_node *node);
199 static void __mark_block_processed(struct reloc_control *rc,
200 struct backref_node *node);
202 static void mapping_tree_init(struct mapping_tree *tree)
204 tree->rb_root = RB_ROOT;
205 spin_lock_init(&tree->lock);
208 static void backref_cache_init(struct backref_cache *cache)
211 cache->rb_root = RB_ROOT;
212 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
213 INIT_LIST_HEAD(&cache->pending[i]);
214 INIT_LIST_HEAD(&cache->changed);
215 INIT_LIST_HEAD(&cache->detached);
216 INIT_LIST_HEAD(&cache->leaves);
219 static void backref_cache_cleanup(struct backref_cache *cache)
221 struct backref_node *node;
224 while (!list_empty(&cache->detached)) {
225 node = list_entry(cache->detached.next,
226 struct backref_node, list);
227 remove_backref_node(cache, node);
230 while (!list_empty(&cache->leaves)) {
231 node = list_entry(cache->leaves.next,
232 struct backref_node, lower);
233 remove_backref_node(cache, node);
236 cache->last_trans = 0;
238 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
239 ASSERT(list_empty(&cache->pending[i]));
240 ASSERT(list_empty(&cache->changed));
241 ASSERT(list_empty(&cache->detached));
242 ASSERT(RB_EMPTY_ROOT(&cache->rb_root));
243 ASSERT(!cache->nr_nodes);
244 ASSERT(!cache->nr_edges);
247 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
249 struct backref_node *node;
251 node = kzalloc(sizeof(*node), GFP_NOFS);
253 INIT_LIST_HEAD(&node->list);
254 INIT_LIST_HEAD(&node->upper);
255 INIT_LIST_HEAD(&node->lower);
256 RB_CLEAR_NODE(&node->rb_node);
262 static void free_backref_node(struct backref_cache *cache,
263 struct backref_node *node)
271 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
273 struct backref_edge *edge;
275 edge = kzalloc(sizeof(*edge), GFP_NOFS);
281 static void free_backref_edge(struct backref_cache *cache,
282 struct backref_edge *edge)
290 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
291 struct rb_node *node)
293 struct rb_node **p = &root->rb_node;
294 struct rb_node *parent = NULL;
295 struct tree_entry *entry;
299 entry = rb_entry(parent, struct tree_entry, rb_node);
301 if (bytenr < entry->bytenr)
303 else if (bytenr > entry->bytenr)
309 rb_link_node(node, parent, p);
310 rb_insert_color(node, root);
314 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
316 struct rb_node *n = root->rb_node;
317 struct tree_entry *entry;
320 entry = rb_entry(n, struct tree_entry, rb_node);
322 if (bytenr < entry->bytenr)
324 else if (bytenr > entry->bytenr)
332 static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
335 struct btrfs_fs_info *fs_info = NULL;
336 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
339 fs_info = bnode->root->fs_info;
340 btrfs_panic(fs_info, errno,
341 "Inconsistency in backref cache found at offset %llu",
346 * walk up backref nodes until reach node presents tree root
348 static struct backref_node *walk_up_backref(struct backref_node *node,
349 struct backref_edge *edges[],
352 struct backref_edge *edge;
355 while (!list_empty(&node->upper)) {
356 edge = list_entry(node->upper.next,
357 struct backref_edge, list[LOWER]);
359 node = edge->node[UPPER];
361 BUG_ON(node->detached);
367 * walk down backref nodes to find start of next reference path
369 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
372 struct backref_edge *edge;
373 struct backref_node *lower;
377 edge = edges[idx - 1];
378 lower = edge->node[LOWER];
379 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
383 edge = list_entry(edge->list[LOWER].next,
384 struct backref_edge, list[LOWER]);
385 edges[idx - 1] = edge;
387 return edge->node[UPPER];
393 static void unlock_node_buffer(struct backref_node *node)
396 btrfs_tree_unlock(node->eb);
401 static void drop_node_buffer(struct backref_node *node)
404 unlock_node_buffer(node);
405 free_extent_buffer(node->eb);
410 static void drop_backref_node(struct backref_cache *tree,
411 struct backref_node *node)
413 BUG_ON(!list_empty(&node->upper));
415 drop_node_buffer(node);
416 list_del(&node->list);
417 list_del(&node->lower);
418 if (!RB_EMPTY_NODE(&node->rb_node))
419 rb_erase(&node->rb_node, &tree->rb_root);
420 free_backref_node(tree, node);
424 * remove a backref node from the backref cache
426 static void remove_backref_node(struct backref_cache *cache,
427 struct backref_node *node)
429 struct backref_node *upper;
430 struct backref_edge *edge;
435 BUG_ON(!node->lowest && !node->detached);
436 while (!list_empty(&node->upper)) {
437 edge = list_entry(node->upper.next, struct backref_edge,
439 upper = edge->node[UPPER];
440 list_del(&edge->list[LOWER]);
441 list_del(&edge->list[UPPER]);
442 free_backref_edge(cache, edge);
444 if (RB_EMPTY_NODE(&upper->rb_node)) {
445 BUG_ON(!list_empty(&node->upper));
446 drop_backref_node(cache, node);
452 * add the node to leaf node list if no other
453 * child block cached.
455 if (list_empty(&upper->lower)) {
456 list_add_tail(&upper->lower, &cache->leaves);
461 drop_backref_node(cache, node);
464 static void update_backref_node(struct backref_cache *cache,
465 struct backref_node *node, u64 bytenr)
467 struct rb_node *rb_node;
468 rb_erase(&node->rb_node, &cache->rb_root);
469 node->bytenr = bytenr;
470 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
472 backref_tree_panic(rb_node, -EEXIST, bytenr);
476 * update backref cache after a transaction commit
478 static int update_backref_cache(struct btrfs_trans_handle *trans,
479 struct backref_cache *cache)
481 struct backref_node *node;
484 if (cache->last_trans == 0) {
485 cache->last_trans = trans->transid;
489 if (cache->last_trans == trans->transid)
493 * detached nodes are used to avoid unnecessary backref
494 * lookup. transaction commit changes the extent tree.
495 * so the detached nodes are no longer useful.
497 while (!list_empty(&cache->detached)) {
498 node = list_entry(cache->detached.next,
499 struct backref_node, list);
500 remove_backref_node(cache, node);
503 while (!list_empty(&cache->changed)) {
504 node = list_entry(cache->changed.next,
505 struct backref_node, list);
506 list_del_init(&node->list);
507 BUG_ON(node->pending);
508 update_backref_node(cache, node, node->new_bytenr);
512 * some nodes can be left in the pending list if there were
513 * errors during processing the pending nodes.
515 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
516 list_for_each_entry(node, &cache->pending[level], list) {
517 BUG_ON(!node->pending);
518 if (node->bytenr == node->new_bytenr)
520 update_backref_node(cache, node, node->new_bytenr);
524 cache->last_trans = 0;
529 static int should_ignore_root(struct btrfs_root *root)
531 struct btrfs_root *reloc_root;
533 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
536 reloc_root = root->reloc_root;
540 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
541 root->fs_info->running_transaction->transid - 1)
544 * if there is reloc tree and it was created in previous
545 * transaction backref lookup can find the reloc tree,
546 * so backref node for the fs tree root is useless for
552 * find reloc tree by address of tree root
554 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
557 struct rb_node *rb_node;
558 struct mapping_node *node;
559 struct btrfs_root *root = NULL;
561 spin_lock(&rc->reloc_root_tree.lock);
562 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
564 node = rb_entry(rb_node, struct mapping_node, rb_node);
565 root = (struct btrfs_root *)node->data;
567 spin_unlock(&rc->reloc_root_tree.lock);
571 static int is_cowonly_root(u64 root_objectid)
573 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
574 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
575 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
576 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
577 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
578 root_objectid == BTRFS_CSUM_TREE_OBJECTID ||
579 root_objectid == BTRFS_UUID_TREE_OBJECTID ||
580 root_objectid == BTRFS_QUOTA_TREE_OBJECTID ||
581 root_objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
586 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
589 struct btrfs_key key;
591 key.objectid = root_objectid;
592 key.type = BTRFS_ROOT_ITEM_KEY;
593 if (is_cowonly_root(root_objectid))
596 key.offset = (u64)-1;
598 return btrfs_get_fs_root(fs_info, &key, false);
601 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
602 static noinline_for_stack
603 struct btrfs_root *find_tree_root(struct reloc_control *rc,
604 struct extent_buffer *leaf,
605 struct btrfs_extent_ref_v0 *ref0)
607 struct btrfs_root *root;
608 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
609 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
611 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
613 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
614 BUG_ON(IS_ERR(root));
616 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state) &&
617 generation != btrfs_root_generation(&root->root_item))
624 static noinline_for_stack
625 int find_inline_backref(struct extent_buffer *leaf, int slot,
626 unsigned long *ptr, unsigned long *end)
628 struct btrfs_key key;
629 struct btrfs_extent_item *ei;
630 struct btrfs_tree_block_info *bi;
633 btrfs_item_key_to_cpu(leaf, &key, slot);
635 item_size = btrfs_item_size_nr(leaf, slot);
636 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
637 if (item_size < sizeof(*ei)) {
638 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
642 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
643 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
644 BTRFS_EXTENT_FLAG_TREE_BLOCK));
646 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
647 item_size <= sizeof(*ei) + sizeof(*bi)) {
648 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
651 if (key.type == BTRFS_METADATA_ITEM_KEY &&
652 item_size <= sizeof(*ei)) {
653 WARN_ON(item_size < sizeof(*ei));
657 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
658 bi = (struct btrfs_tree_block_info *)(ei + 1);
659 *ptr = (unsigned long)(bi + 1);
661 *ptr = (unsigned long)(ei + 1);
663 *end = (unsigned long)ei + item_size;
668 * build backref tree for a given tree block. root of the backref tree
669 * corresponds the tree block, leaves of the backref tree correspond
670 * roots of b-trees that reference the tree block.
672 * the basic idea of this function is check backrefs of a given block
673 * to find upper level blocks that reference the block, and then check
674 * backrefs of these upper level blocks recursively. the recursion stop
675 * when tree root is reached or backrefs for the block is cached.
677 * NOTE: if we find backrefs for a block are cached, we know backrefs
678 * for all upper level blocks that directly/indirectly reference the
679 * block are also cached.
681 static noinline_for_stack
682 struct backref_node *build_backref_tree(struct reloc_control *rc,
683 struct btrfs_key *node_key,
684 int level, u64 bytenr)
686 struct backref_cache *cache = &rc->backref_cache;
687 struct btrfs_path *path1;
688 struct btrfs_path *path2;
689 struct extent_buffer *eb;
690 struct btrfs_root *root;
691 struct backref_node *cur;
692 struct backref_node *upper;
693 struct backref_node *lower;
694 struct backref_node *node = NULL;
695 struct backref_node *exist = NULL;
696 struct backref_edge *edge;
697 struct rb_node *rb_node;
698 struct btrfs_key key;
706 bool need_check = true;
708 path1 = btrfs_alloc_path();
709 path2 = btrfs_alloc_path();
710 if (!path1 || !path2) {
714 path1->reada = READA_FORWARD;
715 path2->reada = READA_FORWARD;
717 node = alloc_backref_node(cache);
723 node->bytenr = bytenr;
730 key.objectid = cur->bytenr;
731 key.type = BTRFS_METADATA_ITEM_KEY;
732 key.offset = (u64)-1;
734 path1->search_commit_root = 1;
735 path1->skip_locking = 1;
736 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
743 ASSERT(path1->slots[0]);
747 WARN_ON(cur->checked);
748 if (!list_empty(&cur->upper)) {
750 * the backref was added previously when processing
751 * backref of type BTRFS_TREE_BLOCK_REF_KEY
753 ASSERT(list_is_singular(&cur->upper));
754 edge = list_entry(cur->upper.next, struct backref_edge,
756 ASSERT(list_empty(&edge->list[UPPER]));
757 exist = edge->node[UPPER];
759 * add the upper level block to pending list if we need
763 list_add_tail(&edge->list[UPPER], &list);
770 eb = path1->nodes[0];
773 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
774 ret = btrfs_next_leaf(rc->extent_root, path1);
781 eb = path1->nodes[0];
784 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
785 if (key.objectid != cur->bytenr) {
790 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
791 key.type == BTRFS_METADATA_ITEM_KEY) {
792 ret = find_inline_backref(eb, path1->slots[0],
800 /* update key for inline back ref */
801 struct btrfs_extent_inline_ref *iref;
802 iref = (struct btrfs_extent_inline_ref *)ptr;
803 key.type = btrfs_extent_inline_ref_type(eb, iref);
804 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
805 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
806 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
810 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
811 exist->owner == key.offset) ||
812 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
813 exist->bytenr == key.offset))) {
818 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
819 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
820 key.type == BTRFS_EXTENT_REF_V0_KEY) {
821 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
822 struct btrfs_extent_ref_v0 *ref0;
823 ref0 = btrfs_item_ptr(eb, path1->slots[0],
824 struct btrfs_extent_ref_v0);
825 if (key.objectid == key.offset) {
826 root = find_tree_root(rc, eb, ref0);
827 if (root && !should_ignore_root(root))
830 list_add(&cur->list, &useless);
833 if (is_cowonly_root(btrfs_ref_root_v0(eb,
838 ASSERT(key.type != BTRFS_EXTENT_REF_V0_KEY);
839 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
841 if (key.objectid == key.offset) {
843 * only root blocks of reloc trees use
844 * backref of this type.
846 root = find_reloc_root(rc, cur->bytenr);
852 edge = alloc_backref_edge(cache);
857 rb_node = tree_search(&cache->rb_root, key.offset);
859 upper = alloc_backref_node(cache);
861 free_backref_edge(cache, edge);
865 upper->bytenr = key.offset;
866 upper->level = cur->level + 1;
868 * backrefs for the upper level block isn't
869 * cached, add the block to pending list
871 list_add_tail(&edge->list[UPPER], &list);
873 upper = rb_entry(rb_node, struct backref_node,
875 ASSERT(upper->checked);
876 INIT_LIST_HEAD(&edge->list[UPPER]);
878 list_add_tail(&edge->list[LOWER], &cur->upper);
879 edge->node[LOWER] = cur;
880 edge->node[UPPER] = upper;
883 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
887 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
888 root = read_fs_root(rc->extent_root->fs_info, key.offset);
894 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
897 if (btrfs_root_level(&root->root_item) == cur->level) {
899 ASSERT(btrfs_root_bytenr(&root->root_item) ==
901 if (should_ignore_root(root))
902 list_add(&cur->list, &useless);
908 level = cur->level + 1;
911 * searching the tree to find upper level blocks
912 * reference the block.
914 path2->search_commit_root = 1;
915 path2->skip_locking = 1;
916 path2->lowest_level = level;
917 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
918 path2->lowest_level = 0;
923 if (ret > 0 && path2->slots[level] > 0)
924 path2->slots[level]--;
926 eb = path2->nodes[level];
927 if (btrfs_node_blockptr(eb, path2->slots[level]) !=
929 btrfs_err(root->fs_info,
930 "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)",
931 cur->bytenr, level - 1, root->objectid,
932 node_key->objectid, node_key->type,
939 for (; level < BTRFS_MAX_LEVEL; level++) {
940 if (!path2->nodes[level]) {
941 ASSERT(btrfs_root_bytenr(&root->root_item) ==
943 if (should_ignore_root(root))
944 list_add(&lower->list, &useless);
950 edge = alloc_backref_edge(cache);
956 eb = path2->nodes[level];
957 rb_node = tree_search(&cache->rb_root, eb->start);
959 upper = alloc_backref_node(cache);
961 free_backref_edge(cache, edge);
965 upper->bytenr = eb->start;
966 upper->owner = btrfs_header_owner(eb);
967 upper->level = lower->level + 1;
968 if (!test_bit(BTRFS_ROOT_REF_COWS,
973 * if we know the block isn't shared
974 * we can void checking its backrefs.
976 if (btrfs_block_can_be_shared(root, eb))
982 * add the block to pending list if we
983 * need check its backrefs, we only do this once
984 * while walking up a tree as we will catch
985 * anything else later on.
987 if (!upper->checked && need_check) {
989 list_add_tail(&edge->list[UPPER],
994 INIT_LIST_HEAD(&edge->list[UPPER]);
997 upper = rb_entry(rb_node, struct backref_node,
999 ASSERT(upper->checked);
1000 INIT_LIST_HEAD(&edge->list[UPPER]);
1002 upper->owner = btrfs_header_owner(eb);
1004 list_add_tail(&edge->list[LOWER], &lower->upper);
1005 edge->node[LOWER] = lower;
1006 edge->node[UPPER] = upper;
1013 btrfs_release_path(path2);
1016 ptr += btrfs_extent_inline_ref_size(key.type);
1026 btrfs_release_path(path1);
1031 /* the pending list isn't empty, take the first block to process */
1032 if (!list_empty(&list)) {
1033 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1034 list_del_init(&edge->list[UPPER]);
1035 cur = edge->node[UPPER];
1040 * everything goes well, connect backref nodes and insert backref nodes
1043 ASSERT(node->checked);
1044 cowonly = node->cowonly;
1046 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1049 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1050 list_add_tail(&node->lower, &cache->leaves);
1053 list_for_each_entry(edge, &node->upper, list[LOWER])
1054 list_add_tail(&edge->list[UPPER], &list);
1056 while (!list_empty(&list)) {
1057 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1058 list_del_init(&edge->list[UPPER]);
1059 upper = edge->node[UPPER];
1060 if (upper->detached) {
1061 list_del(&edge->list[LOWER]);
1062 lower = edge->node[LOWER];
1063 free_backref_edge(cache, edge);
1064 if (list_empty(&lower->upper))
1065 list_add(&lower->list, &useless);
1069 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1070 if (upper->lowest) {
1071 list_del_init(&upper->lower);
1075 list_add_tail(&edge->list[UPPER], &upper->lower);
1079 if (!upper->checked) {
1081 * Still want to blow up for developers since this is a
1088 if (cowonly != upper->cowonly) {
1095 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1098 backref_tree_panic(rb_node, -EEXIST,
1102 list_add_tail(&edge->list[UPPER], &upper->lower);
1104 list_for_each_entry(edge, &upper->upper, list[LOWER])
1105 list_add_tail(&edge->list[UPPER], &list);
1108 * process useless backref nodes. backref nodes for tree leaves
1109 * are deleted from the cache. backref nodes for upper level
1110 * tree blocks are left in the cache to avoid unnecessary backref
1113 while (!list_empty(&useless)) {
1114 upper = list_entry(useless.next, struct backref_node, list);
1115 list_del_init(&upper->list);
1116 ASSERT(list_empty(&upper->upper));
1119 if (upper->lowest) {
1120 list_del_init(&upper->lower);
1123 while (!list_empty(&upper->lower)) {
1124 edge = list_entry(upper->lower.next,
1125 struct backref_edge, list[UPPER]);
1126 list_del(&edge->list[UPPER]);
1127 list_del(&edge->list[LOWER]);
1128 lower = edge->node[LOWER];
1129 free_backref_edge(cache, edge);
1131 if (list_empty(&lower->upper))
1132 list_add(&lower->list, &useless);
1134 __mark_block_processed(rc, upper);
1135 if (upper->level > 0) {
1136 list_add(&upper->list, &cache->detached);
1137 upper->detached = 1;
1139 rb_erase(&upper->rb_node, &cache->rb_root);
1140 free_backref_node(cache, upper);
1144 btrfs_free_path(path1);
1145 btrfs_free_path(path2);
1147 while (!list_empty(&useless)) {
1148 lower = list_entry(useless.next,
1149 struct backref_node, list);
1150 list_del_init(&lower->list);
1152 while (!list_empty(&list)) {
1153 edge = list_first_entry(&list, struct backref_edge,
1155 list_del(&edge->list[UPPER]);
1156 list_del(&edge->list[LOWER]);
1157 lower = edge->node[LOWER];
1158 upper = edge->node[UPPER];
1159 free_backref_edge(cache, edge);
1162 * Lower is no longer linked to any upper backref nodes
1163 * and isn't in the cache, we can free it ourselves.
1165 if (list_empty(&lower->upper) &&
1166 RB_EMPTY_NODE(&lower->rb_node))
1167 list_add(&lower->list, &useless);
1169 if (!RB_EMPTY_NODE(&upper->rb_node))
1172 /* Add this guy's upper edges to the list to process */
1173 list_for_each_entry(edge, &upper->upper, list[LOWER])
1174 list_add_tail(&edge->list[UPPER], &list);
1175 if (list_empty(&upper->upper))
1176 list_add(&upper->list, &useless);
1179 while (!list_empty(&useless)) {
1180 lower = list_entry(useless.next,
1181 struct backref_node, list);
1182 list_del_init(&lower->list);
1185 free_backref_node(cache, lower);
1188 free_backref_node(cache, node);
1189 return ERR_PTR(err);
1191 ASSERT(!node || !node->detached);
1196 * helper to add backref node for the newly created snapshot.
1197 * the backref node is created by cloning backref node that
1198 * corresponds to root of source tree
1200 static int clone_backref_node(struct btrfs_trans_handle *trans,
1201 struct reloc_control *rc,
1202 struct btrfs_root *src,
1203 struct btrfs_root *dest)
1205 struct btrfs_root *reloc_root = src->reloc_root;
1206 struct backref_cache *cache = &rc->backref_cache;
1207 struct backref_node *node = NULL;
1208 struct backref_node *new_node;
1209 struct backref_edge *edge;
1210 struct backref_edge *new_edge;
1211 struct rb_node *rb_node;
1213 if (cache->last_trans > 0)
1214 update_backref_cache(trans, cache);
1216 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1218 node = rb_entry(rb_node, struct backref_node, rb_node);
1222 BUG_ON(node->new_bytenr != reloc_root->node->start);
1226 rb_node = tree_search(&cache->rb_root,
1227 reloc_root->commit_root->start);
1229 node = rb_entry(rb_node, struct backref_node,
1231 BUG_ON(node->detached);
1238 new_node = alloc_backref_node(cache);
1242 new_node->bytenr = dest->node->start;
1243 new_node->level = node->level;
1244 new_node->lowest = node->lowest;
1245 new_node->checked = 1;
1246 new_node->root = dest;
1248 if (!node->lowest) {
1249 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1250 new_edge = alloc_backref_edge(cache);
1254 new_edge->node[UPPER] = new_node;
1255 new_edge->node[LOWER] = edge->node[LOWER];
1256 list_add_tail(&new_edge->list[UPPER],
1260 list_add_tail(&new_node->lower, &cache->leaves);
1263 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1264 &new_node->rb_node);
1266 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1268 if (!new_node->lowest) {
1269 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1270 list_add_tail(&new_edge->list[LOWER],
1271 &new_edge->node[LOWER]->upper);
1276 while (!list_empty(&new_node->lower)) {
1277 new_edge = list_entry(new_node->lower.next,
1278 struct backref_edge, list[UPPER]);
1279 list_del(&new_edge->list[UPPER]);
1280 free_backref_edge(cache, new_edge);
1282 free_backref_node(cache, new_node);
1287 * helper to add 'address of tree root -> reloc tree' mapping
1289 static int __must_check __add_reloc_root(struct btrfs_root *root)
1291 struct rb_node *rb_node;
1292 struct mapping_node *node;
1293 struct reloc_control *rc = root->fs_info->reloc_ctl;
1295 node = kmalloc(sizeof(*node), GFP_NOFS);
1299 node->bytenr = root->node->start;
1302 spin_lock(&rc->reloc_root_tree.lock);
1303 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1304 node->bytenr, &node->rb_node);
1305 spin_unlock(&rc->reloc_root_tree.lock);
1307 btrfs_panic(root->fs_info, -EEXIST,
1308 "Duplicate root found for start=%llu while inserting into relocation tree",
1314 list_add_tail(&root->root_list, &rc->reloc_roots);
1319 * helper to delete the 'address of tree root -> reloc tree'
1322 static void __del_reloc_root(struct btrfs_root *root)
1324 struct rb_node *rb_node;
1325 struct mapping_node *node = NULL;
1326 struct reloc_control *rc = root->fs_info->reloc_ctl;
1328 spin_lock(&rc->reloc_root_tree.lock);
1329 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1332 node = rb_entry(rb_node, struct mapping_node, rb_node);
1333 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1335 spin_unlock(&rc->reloc_root_tree.lock);
1339 BUG_ON((struct btrfs_root *)node->data != root);
1341 spin_lock(&root->fs_info->trans_lock);
1342 list_del_init(&root->root_list);
1343 spin_unlock(&root->fs_info->trans_lock);
1348 * helper to update the 'address of tree root -> reloc tree'
1351 static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr)
1353 struct rb_node *rb_node;
1354 struct mapping_node *node = NULL;
1355 struct reloc_control *rc = root->fs_info->reloc_ctl;
1357 spin_lock(&rc->reloc_root_tree.lock);
1358 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1361 node = rb_entry(rb_node, struct mapping_node, rb_node);
1362 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1364 spin_unlock(&rc->reloc_root_tree.lock);
1368 BUG_ON((struct btrfs_root *)node->data != root);
1370 spin_lock(&rc->reloc_root_tree.lock);
1371 node->bytenr = new_bytenr;
1372 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1373 node->bytenr, &node->rb_node);
1374 spin_unlock(&rc->reloc_root_tree.lock);
1376 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1380 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1381 struct btrfs_root *root, u64 objectid)
1383 struct btrfs_root *reloc_root;
1384 struct extent_buffer *eb;
1385 struct btrfs_root_item *root_item;
1386 struct btrfs_key root_key;
1390 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1393 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1394 root_key.type = BTRFS_ROOT_ITEM_KEY;
1395 root_key.offset = objectid;
1397 if (root->root_key.objectid == objectid) {
1398 /* called by btrfs_init_reloc_root */
1399 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1400 BTRFS_TREE_RELOC_OBJECTID);
1403 last_snap = btrfs_root_last_snapshot(&root->root_item);
1404 btrfs_set_root_last_snapshot(&root->root_item,
1405 trans->transid - 1);
1408 * called by btrfs_reloc_post_snapshot_hook.
1409 * the source tree is a reloc tree, all tree blocks
1410 * modified after it was created have RELOC flag
1411 * set in their headers. so it's OK to not update
1412 * the 'last_snapshot'.
1414 ret = btrfs_copy_root(trans, root, root->node, &eb,
1415 BTRFS_TREE_RELOC_OBJECTID);
1419 memcpy(root_item, &root->root_item, sizeof(*root_item));
1420 btrfs_set_root_bytenr(root_item, eb->start);
1421 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1422 btrfs_set_root_generation(root_item, trans->transid);
1424 if (root->root_key.objectid == objectid) {
1425 btrfs_set_root_refs(root_item, 0);
1426 memset(&root_item->drop_progress, 0,
1427 sizeof(struct btrfs_disk_key));
1428 root_item->drop_level = 0;
1430 * abuse rtransid, it is safe because it is impossible to
1431 * receive data into a relocation tree.
1433 btrfs_set_root_rtransid(root_item, last_snap);
1434 btrfs_set_root_otransid(root_item, trans->transid);
1437 btrfs_tree_unlock(eb);
1438 free_extent_buffer(eb);
1440 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1441 &root_key, root_item);
1445 reloc_root = btrfs_read_fs_root(root->fs_info->tree_root, &root_key);
1446 BUG_ON(IS_ERR(reloc_root));
1447 reloc_root->last_trans = trans->transid;
1452 * create reloc tree for a given fs tree. reloc tree is just a
1453 * snapshot of the fs tree with special root objectid.
1455 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1456 struct btrfs_root *root)
1458 struct btrfs_root *reloc_root;
1459 struct reloc_control *rc = root->fs_info->reloc_ctl;
1460 struct btrfs_block_rsv *rsv;
1464 if (root->reloc_root) {
1465 reloc_root = root->reloc_root;
1466 reloc_root->last_trans = trans->transid;
1470 if (!rc || !rc->create_reloc_tree ||
1471 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1474 if (!trans->reloc_reserved) {
1475 rsv = trans->block_rsv;
1476 trans->block_rsv = rc->block_rsv;
1479 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1481 trans->block_rsv = rsv;
1483 ret = __add_reloc_root(reloc_root);
1485 root->reloc_root = reloc_root;
1490 * update root item of reloc tree
1492 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1493 struct btrfs_root *root)
1495 struct btrfs_root *reloc_root;
1496 struct btrfs_root_item *root_item;
1499 if (!root->reloc_root)
1502 reloc_root = root->reloc_root;
1503 root_item = &reloc_root->root_item;
1505 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1506 btrfs_root_refs(root_item) == 0) {
1507 root->reloc_root = NULL;
1508 __del_reloc_root(reloc_root);
1511 if (reloc_root->commit_root != reloc_root->node) {
1512 btrfs_set_root_node(root_item, reloc_root->node);
1513 free_extent_buffer(reloc_root->commit_root);
1514 reloc_root->commit_root = btrfs_root_node(reloc_root);
1517 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1518 &reloc_root->root_key, root_item);
1526 * helper to find first cached inode with inode number >= objectid
1529 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1531 struct rb_node *node;
1532 struct rb_node *prev;
1533 struct btrfs_inode *entry;
1534 struct inode *inode;
1536 spin_lock(&root->inode_lock);
1538 node = root->inode_tree.rb_node;
1542 entry = rb_entry(node, struct btrfs_inode, rb_node);
1544 if (objectid < btrfs_ino(&entry->vfs_inode))
1545 node = node->rb_left;
1546 else if (objectid > btrfs_ino(&entry->vfs_inode))
1547 node = node->rb_right;
1553 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1554 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1558 prev = rb_next(prev);
1562 entry = rb_entry(node, struct btrfs_inode, rb_node);
1563 inode = igrab(&entry->vfs_inode);
1565 spin_unlock(&root->inode_lock);
1569 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1570 if (cond_resched_lock(&root->inode_lock))
1573 node = rb_next(node);
1575 spin_unlock(&root->inode_lock);
1579 static int in_block_group(u64 bytenr,
1580 struct btrfs_block_group_cache *block_group)
1582 if (bytenr >= block_group->key.objectid &&
1583 bytenr < block_group->key.objectid + block_group->key.offset)
1589 * get new location of data
1591 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1592 u64 bytenr, u64 num_bytes)
1594 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1595 struct btrfs_path *path;
1596 struct btrfs_file_extent_item *fi;
1597 struct extent_buffer *leaf;
1600 path = btrfs_alloc_path();
1604 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1605 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1614 leaf = path->nodes[0];
1615 fi = btrfs_item_ptr(leaf, path->slots[0],
1616 struct btrfs_file_extent_item);
1618 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1619 btrfs_file_extent_compression(leaf, fi) ||
1620 btrfs_file_extent_encryption(leaf, fi) ||
1621 btrfs_file_extent_other_encoding(leaf, fi));
1623 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1628 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1631 btrfs_free_path(path);
1636 * update file extent items in the tree leaf to point to
1637 * the new locations.
1639 static noinline_for_stack
1640 int replace_file_extents(struct btrfs_trans_handle *trans,
1641 struct reloc_control *rc,
1642 struct btrfs_root *root,
1643 struct extent_buffer *leaf)
1645 struct btrfs_key key;
1646 struct btrfs_file_extent_item *fi;
1647 struct inode *inode = NULL;
1659 if (rc->stage != UPDATE_DATA_PTRS)
1662 /* reloc trees always use full backref */
1663 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1664 parent = leaf->start;
1668 nritems = btrfs_header_nritems(leaf);
1669 for (i = 0; i < nritems; i++) {
1671 btrfs_item_key_to_cpu(leaf, &key, i);
1672 if (key.type != BTRFS_EXTENT_DATA_KEY)
1674 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1675 if (btrfs_file_extent_type(leaf, fi) ==
1676 BTRFS_FILE_EXTENT_INLINE)
1678 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1679 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1682 if (!in_block_group(bytenr, rc->block_group))
1686 * if we are modifying block in fs tree, wait for readpage
1687 * to complete and drop the extent cache
1689 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1691 inode = find_next_inode(root, key.objectid);
1693 } else if (inode && btrfs_ino(inode) < key.objectid) {
1694 btrfs_add_delayed_iput(inode);
1695 inode = find_next_inode(root, key.objectid);
1697 if (inode && btrfs_ino(inode) == key.objectid) {
1699 btrfs_file_extent_num_bytes(leaf, fi);
1700 WARN_ON(!IS_ALIGNED(key.offset,
1702 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1704 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1709 btrfs_drop_extent_cache(inode, key.offset, end,
1711 unlock_extent(&BTRFS_I(inode)->io_tree,
1716 ret = get_new_location(rc->data_inode, &new_bytenr,
1720 * Don't have to abort since we've not changed anything
1721 * in the file extent yet.
1726 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1729 key.offset -= btrfs_file_extent_offset(leaf, fi);
1730 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1732 btrfs_header_owner(leaf),
1733 key.objectid, key.offset);
1735 btrfs_abort_transaction(trans, ret);
1739 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1740 parent, btrfs_header_owner(leaf),
1741 key.objectid, key.offset);
1743 btrfs_abort_transaction(trans, ret);
1748 btrfs_mark_buffer_dirty(leaf);
1750 btrfs_add_delayed_iput(inode);
1754 static noinline_for_stack
1755 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1756 struct btrfs_path *path, int level)
1758 struct btrfs_disk_key key1;
1759 struct btrfs_disk_key key2;
1760 btrfs_node_key(eb, &key1, slot);
1761 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1762 return memcmp(&key1, &key2, sizeof(key1));
1766 * try to replace tree blocks in fs tree with the new blocks
1767 * in reloc tree. tree blocks haven't been modified since the
1768 * reloc tree was create can be replaced.
1770 * if a block was replaced, level of the block + 1 is returned.
1771 * if no block got replaced, 0 is returned. if there are other
1772 * errors, a negative error number is returned.
1774 static noinline_for_stack
1775 int replace_path(struct btrfs_trans_handle *trans,
1776 struct btrfs_root *dest, struct btrfs_root *src,
1777 struct btrfs_path *path, struct btrfs_key *next_key,
1778 int lowest_level, int max_level)
1780 struct extent_buffer *eb;
1781 struct extent_buffer *parent;
1782 struct btrfs_key key;
1794 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1795 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1797 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1799 slot = path->slots[lowest_level];
1800 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1802 eb = btrfs_lock_root_node(dest);
1803 btrfs_set_lock_blocking(eb);
1804 level = btrfs_header_level(eb);
1806 if (level < lowest_level) {
1807 btrfs_tree_unlock(eb);
1808 free_extent_buffer(eb);
1813 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1816 btrfs_set_lock_blocking(eb);
1819 next_key->objectid = (u64)-1;
1820 next_key->type = (u8)-1;
1821 next_key->offset = (u64)-1;
1826 level = btrfs_header_level(parent);
1827 BUG_ON(level < lowest_level);
1829 ret = btrfs_bin_search(parent, &key, level, &slot);
1830 if (ret && slot > 0)
1833 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1834 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1836 old_bytenr = btrfs_node_blockptr(parent, slot);
1837 blocksize = dest->nodesize;
1838 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1840 if (level <= max_level) {
1841 eb = path->nodes[level];
1842 new_bytenr = btrfs_node_blockptr(eb,
1843 path->slots[level]);
1844 new_ptr_gen = btrfs_node_ptr_generation(eb,
1845 path->slots[level]);
1851 if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
1856 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1857 memcmp_node_keys(parent, slot, path, level)) {
1858 if (level <= lowest_level) {
1863 eb = read_tree_block(dest, old_bytenr, old_ptr_gen);
1867 } else if (!extent_buffer_uptodate(eb)) {
1869 free_extent_buffer(eb);
1872 btrfs_tree_lock(eb);
1874 ret = btrfs_cow_block(trans, dest, eb, parent,
1878 btrfs_set_lock_blocking(eb);
1880 btrfs_tree_unlock(parent);
1881 free_extent_buffer(parent);
1888 btrfs_tree_unlock(parent);
1889 free_extent_buffer(parent);
1894 btrfs_node_key_to_cpu(path->nodes[level], &key,
1895 path->slots[level]);
1896 btrfs_release_path(path);
1898 path->lowest_level = level;
1899 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1900 path->lowest_level = 0;
1904 * swap blocks in fs tree and reloc tree.
1906 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1907 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1908 btrfs_mark_buffer_dirty(parent);
1910 btrfs_set_node_blockptr(path->nodes[level],
1911 path->slots[level], old_bytenr);
1912 btrfs_set_node_ptr_generation(path->nodes[level],
1913 path->slots[level], old_ptr_gen);
1914 btrfs_mark_buffer_dirty(path->nodes[level]);
1916 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1917 path->nodes[level]->start,
1918 src->root_key.objectid, level - 1, 0);
1920 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1921 0, dest->root_key.objectid, level - 1,
1925 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1926 path->nodes[level]->start,
1927 src->root_key.objectid, level - 1, 0);
1930 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1931 0, dest->root_key.objectid, level - 1,
1935 btrfs_unlock_up_safe(path, 0);
1940 btrfs_tree_unlock(parent);
1941 free_extent_buffer(parent);
1946 * helper to find next relocated block in reloc tree
1948 static noinline_for_stack
1949 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1952 struct extent_buffer *eb;
1957 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1959 for (i = 0; i < *level; i++) {
1960 free_extent_buffer(path->nodes[i]);
1961 path->nodes[i] = NULL;
1964 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1965 eb = path->nodes[i];
1966 nritems = btrfs_header_nritems(eb);
1967 while (path->slots[i] + 1 < nritems) {
1969 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1976 free_extent_buffer(path->nodes[i]);
1977 path->nodes[i] = NULL;
1983 * walk down reloc tree to find relocated block of lowest level
1985 static noinline_for_stack
1986 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1989 struct extent_buffer *eb = NULL;
1996 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1998 for (i = *level; i > 0; i--) {
1999 eb = path->nodes[i];
2000 nritems = btrfs_header_nritems(eb);
2001 while (path->slots[i] < nritems) {
2002 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
2003 if (ptr_gen > last_snapshot)
2007 if (path->slots[i] >= nritems) {
2018 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
2019 eb = read_tree_block(root, bytenr, ptr_gen);
2022 } else if (!extent_buffer_uptodate(eb)) {
2023 free_extent_buffer(eb);
2026 BUG_ON(btrfs_header_level(eb) != i - 1);
2027 path->nodes[i - 1] = eb;
2028 path->slots[i - 1] = 0;
2034 * invalidate extent cache for file extents whose key in range of
2035 * [min_key, max_key)
2037 static int invalidate_extent_cache(struct btrfs_root *root,
2038 struct btrfs_key *min_key,
2039 struct btrfs_key *max_key)
2041 struct inode *inode = NULL;
2046 objectid = min_key->objectid;
2051 if (objectid > max_key->objectid)
2054 inode = find_next_inode(root, objectid);
2057 ino = btrfs_ino(inode);
2059 if (ino > max_key->objectid) {
2065 if (!S_ISREG(inode->i_mode))
2068 if (unlikely(min_key->objectid == ino)) {
2069 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
2071 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
2074 start = min_key->offset;
2075 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
2081 if (unlikely(max_key->objectid == ino)) {
2082 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2084 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2087 if (max_key->offset == 0)
2089 end = max_key->offset;
2090 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2097 /* the lock_extent waits for readpage to complete */
2098 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2099 btrfs_drop_extent_cache(inode, start, end, 1);
2100 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2105 static int find_next_key(struct btrfs_path *path, int level,
2106 struct btrfs_key *key)
2109 while (level < BTRFS_MAX_LEVEL) {
2110 if (!path->nodes[level])
2112 if (path->slots[level] + 1 <
2113 btrfs_header_nritems(path->nodes[level])) {
2114 btrfs_node_key_to_cpu(path->nodes[level], key,
2115 path->slots[level] + 1);
2124 * merge the relocated tree blocks in reloc tree with corresponding
2127 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2128 struct btrfs_root *root)
2130 LIST_HEAD(inode_list);
2131 struct btrfs_key key;
2132 struct btrfs_key next_key;
2133 struct btrfs_trans_handle *trans = NULL;
2134 struct btrfs_root *reloc_root;
2135 struct btrfs_root_item *root_item;
2136 struct btrfs_path *path;
2137 struct extent_buffer *leaf;
2145 path = btrfs_alloc_path();
2148 path->reada = READA_FORWARD;
2150 reloc_root = root->reloc_root;
2151 root_item = &reloc_root->root_item;
2153 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2154 level = btrfs_root_level(root_item);
2155 extent_buffer_get(reloc_root->node);
2156 path->nodes[level] = reloc_root->node;
2157 path->slots[level] = 0;
2159 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2161 level = root_item->drop_level;
2163 path->lowest_level = level;
2164 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2165 path->lowest_level = 0;
2167 btrfs_free_path(path);
2171 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2172 path->slots[level]);
2173 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2175 btrfs_unlock_up_safe(path, 0);
2178 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2179 memset(&next_key, 0, sizeof(next_key));
2182 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2183 BTRFS_RESERVE_FLUSH_ALL);
2188 trans = btrfs_start_transaction(root, 0);
2189 if (IS_ERR(trans)) {
2190 err = PTR_ERR(trans);
2194 trans->block_rsv = rc->block_rsv;
2199 ret = walk_down_reloc_tree(reloc_root, path, &level);
2207 if (!find_next_key(path, level, &key) &&
2208 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2211 ret = replace_path(trans, root, reloc_root, path,
2212 &next_key, level, max_level);
2221 btrfs_node_key_to_cpu(path->nodes[level], &key,
2222 path->slots[level]);
2226 ret = walk_up_reloc_tree(reloc_root, path, &level);
2232 * save the merging progress in the drop_progress.
2233 * this is OK since root refs == 1 in this case.
2235 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2236 path->slots[level]);
2237 root_item->drop_level = level;
2239 btrfs_end_transaction_throttle(trans, root);
2242 btrfs_btree_balance_dirty(root);
2244 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2245 invalidate_extent_cache(root, &key, &next_key);
2249 * handle the case only one block in the fs tree need to be
2250 * relocated and the block is tree root.
2252 leaf = btrfs_lock_root_node(root);
2253 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2254 btrfs_tree_unlock(leaf);
2255 free_extent_buffer(leaf);
2259 btrfs_free_path(path);
2262 memset(&root_item->drop_progress, 0,
2263 sizeof(root_item->drop_progress));
2264 root_item->drop_level = 0;
2265 btrfs_set_root_refs(root_item, 0);
2266 btrfs_update_reloc_root(trans, root);
2270 btrfs_end_transaction_throttle(trans, root);
2272 btrfs_btree_balance_dirty(root);
2274 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2275 invalidate_extent_cache(root, &key, &next_key);
2280 static noinline_for_stack
2281 int prepare_to_merge(struct reloc_control *rc, int err)
2283 struct btrfs_root *root = rc->extent_root;
2284 struct btrfs_root *reloc_root;
2285 struct btrfs_trans_handle *trans;
2286 LIST_HEAD(reloc_roots);
2290 mutex_lock(&root->fs_info->reloc_mutex);
2291 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2292 rc->merging_rsv_size += rc->nodes_relocated * 2;
2293 mutex_unlock(&root->fs_info->reloc_mutex);
2297 num_bytes = rc->merging_rsv_size;
2298 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2299 BTRFS_RESERVE_FLUSH_ALL);
2304 trans = btrfs_join_transaction(rc->extent_root);
2305 if (IS_ERR(trans)) {
2307 btrfs_block_rsv_release(rc->extent_root,
2308 rc->block_rsv, num_bytes);
2309 return PTR_ERR(trans);
2313 if (num_bytes != rc->merging_rsv_size) {
2314 btrfs_end_transaction(trans, rc->extent_root);
2315 btrfs_block_rsv_release(rc->extent_root,
2316 rc->block_rsv, num_bytes);
2321 rc->merge_reloc_tree = 1;
2323 while (!list_empty(&rc->reloc_roots)) {
2324 reloc_root = list_entry(rc->reloc_roots.next,
2325 struct btrfs_root, root_list);
2326 list_del_init(&reloc_root->root_list);
2328 root = read_fs_root(reloc_root->fs_info,
2329 reloc_root->root_key.offset);
2330 BUG_ON(IS_ERR(root));
2331 BUG_ON(root->reloc_root != reloc_root);
2334 * set reference count to 1, so btrfs_recover_relocation
2335 * knows it should resumes merging
2338 btrfs_set_root_refs(&reloc_root->root_item, 1);
2339 btrfs_update_reloc_root(trans, root);
2341 list_add(&reloc_root->root_list, &reloc_roots);
2344 list_splice(&reloc_roots, &rc->reloc_roots);
2347 btrfs_commit_transaction(trans, rc->extent_root);
2349 btrfs_end_transaction(trans, rc->extent_root);
2353 static noinline_for_stack
2354 void free_reloc_roots(struct list_head *list)
2356 struct btrfs_root *reloc_root;
2358 while (!list_empty(list)) {
2359 reloc_root = list_entry(list->next, struct btrfs_root,
2361 free_extent_buffer(reloc_root->node);
2362 free_extent_buffer(reloc_root->commit_root);
2363 reloc_root->node = NULL;
2364 reloc_root->commit_root = NULL;
2365 __del_reloc_root(reloc_root);
2369 static noinline_for_stack
2370 void merge_reloc_roots(struct reloc_control *rc)
2372 struct btrfs_root *root;
2373 struct btrfs_root *reloc_root;
2377 LIST_HEAD(reloc_roots);
2381 root = rc->extent_root;
2384 * this serializes us with btrfs_record_root_in_transaction,
2385 * we have to make sure nobody is in the middle of
2386 * adding their roots to the list while we are
2389 mutex_lock(&root->fs_info->reloc_mutex);
2390 list_splice_init(&rc->reloc_roots, &reloc_roots);
2391 mutex_unlock(&root->fs_info->reloc_mutex);
2393 while (!list_empty(&reloc_roots)) {
2395 reloc_root = list_entry(reloc_roots.next,
2396 struct btrfs_root, root_list);
2398 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2399 root = read_fs_root(reloc_root->fs_info,
2400 reloc_root->root_key.offset);
2401 BUG_ON(IS_ERR(root));
2402 BUG_ON(root->reloc_root != reloc_root);
2404 ret = merge_reloc_root(rc, root);
2406 if (list_empty(&reloc_root->root_list))
2407 list_add_tail(&reloc_root->root_list,
2412 list_del_init(&reloc_root->root_list);
2416 * we keep the old last snapshot transid in rtranid when we
2417 * created the relocation tree.
2419 last_snap = btrfs_root_rtransid(&reloc_root->root_item);
2420 otransid = btrfs_root_otransid(&reloc_root->root_item);
2421 objectid = reloc_root->root_key.offset;
2423 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2425 if (list_empty(&reloc_root->root_list))
2426 list_add_tail(&reloc_root->root_list,
2438 btrfs_handle_fs_error(root->fs_info, ret, NULL);
2439 if (!list_empty(&reloc_roots))
2440 free_reloc_roots(&reloc_roots);
2442 /* new reloc root may be added */
2443 mutex_lock(&root->fs_info->reloc_mutex);
2444 list_splice_init(&rc->reloc_roots, &reloc_roots);
2445 mutex_unlock(&root->fs_info->reloc_mutex);
2446 if (!list_empty(&reloc_roots))
2447 free_reloc_roots(&reloc_roots);
2450 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2453 static void free_block_list(struct rb_root *blocks)
2455 struct tree_block *block;
2456 struct rb_node *rb_node;
2457 while ((rb_node = rb_first(blocks))) {
2458 block = rb_entry(rb_node, struct tree_block, rb_node);
2459 rb_erase(rb_node, blocks);
2464 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2465 struct btrfs_root *reloc_root)
2467 struct btrfs_root *root;
2469 if (reloc_root->last_trans == trans->transid)
2472 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2473 BUG_ON(IS_ERR(root));
2474 BUG_ON(root->reloc_root != reloc_root);
2476 return btrfs_record_root_in_trans(trans, root);
2479 static noinline_for_stack
2480 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2481 struct reloc_control *rc,
2482 struct backref_node *node,
2483 struct backref_edge *edges[])
2485 struct backref_node *next;
2486 struct btrfs_root *root;
2492 next = walk_up_backref(next, edges, &index);
2495 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS, &root->state));
2497 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2498 record_reloc_root_in_trans(trans, root);
2502 btrfs_record_root_in_trans(trans, root);
2503 root = root->reloc_root;
2505 if (next->new_bytenr != root->node->start) {
2506 BUG_ON(next->new_bytenr);
2507 BUG_ON(!list_empty(&next->list));
2508 next->new_bytenr = root->node->start;
2510 list_add_tail(&next->list,
2511 &rc->backref_cache.changed);
2512 __mark_block_processed(rc, next);
2518 next = walk_down_backref(edges, &index);
2519 if (!next || next->level <= node->level)
2526 /* setup backref node path for btrfs_reloc_cow_block */
2528 rc->backref_cache.path[next->level] = next;
2531 next = edges[index]->node[UPPER];
2537 * select a tree root for relocation. return NULL if the block
2538 * is reference counted. we should use do_relocation() in this
2539 * case. return a tree root pointer if the block isn't reference
2540 * counted. return -ENOENT if the block is root of reloc tree.
2542 static noinline_for_stack
2543 struct btrfs_root *select_one_root(struct backref_node *node)
2545 struct backref_node *next;
2546 struct btrfs_root *root;
2547 struct btrfs_root *fs_root = NULL;
2548 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2554 next = walk_up_backref(next, edges, &index);
2558 /* no other choice for non-references counted tree */
2559 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
2562 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2568 next = walk_down_backref(edges, &index);
2569 if (!next || next->level <= node->level)
2574 return ERR_PTR(-ENOENT);
2578 static noinline_for_stack
2579 u64 calcu_metadata_size(struct reloc_control *rc,
2580 struct backref_node *node, int reserve)
2582 struct backref_node *next = node;
2583 struct backref_edge *edge;
2584 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2588 BUG_ON(reserve && node->processed);
2593 if (next->processed && (reserve || next != node))
2596 num_bytes += rc->extent_root->nodesize;
2598 if (list_empty(&next->upper))
2601 edge = list_entry(next->upper.next,
2602 struct backref_edge, list[LOWER]);
2603 edges[index++] = edge;
2604 next = edge->node[UPPER];
2606 next = walk_down_backref(edges, &index);
2611 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2612 struct reloc_control *rc,
2613 struct backref_node *node)
2615 struct btrfs_root *root = rc->extent_root;
2620 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2622 trans->block_rsv = rc->block_rsv;
2623 rc->reserved_bytes += num_bytes;
2626 * We are under a transaction here so we can only do limited flushing.
2627 * If we get an enospc just kick back -EAGAIN so we know to drop the
2628 * transaction and try to refill when we can flush all the things.
2630 ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes,
2631 BTRFS_RESERVE_FLUSH_LIMIT);
2633 tmp = rc->extent_root->nodesize * RELOCATION_RESERVED_NODES;
2634 while (tmp <= rc->reserved_bytes)
2637 * only one thread can access block_rsv at this point,
2638 * so we don't need hold lock to protect block_rsv.
2639 * we expand more reservation size here to allow enough
2640 * space for relocation and we will return eailer in
2643 rc->block_rsv->size = tmp + rc->extent_root->nodesize *
2644 RELOCATION_RESERVED_NODES;
2652 * relocate a block tree, and then update pointers in upper level
2653 * blocks that reference the block to point to the new location.
2655 * if called by link_to_upper, the block has already been relocated.
2656 * in that case this function just updates pointers.
2658 static int do_relocation(struct btrfs_trans_handle *trans,
2659 struct reloc_control *rc,
2660 struct backref_node *node,
2661 struct btrfs_key *key,
2662 struct btrfs_path *path, int lowest)
2664 struct backref_node *upper;
2665 struct backref_edge *edge;
2666 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2667 struct btrfs_root *root;
2668 struct extent_buffer *eb;
2676 BUG_ON(lowest && node->eb);
2678 path->lowest_level = node->level + 1;
2679 rc->backref_cache.path[node->level] = node;
2680 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2683 upper = edge->node[UPPER];
2684 root = select_reloc_root(trans, rc, upper, edges);
2687 if (upper->eb && !upper->locked) {
2689 ret = btrfs_bin_search(upper->eb, key,
2690 upper->level, &slot);
2692 bytenr = btrfs_node_blockptr(upper->eb, slot);
2693 if (node->eb->start == bytenr)
2696 drop_node_buffer(upper);
2700 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2707 btrfs_release_path(path);
2712 upper->eb = path->nodes[upper->level];
2713 path->nodes[upper->level] = NULL;
2715 BUG_ON(upper->eb != path->nodes[upper->level]);
2719 path->locks[upper->level] = 0;
2721 slot = path->slots[upper->level];
2722 btrfs_release_path(path);
2724 ret = btrfs_bin_search(upper->eb, key, upper->level,
2729 bytenr = btrfs_node_blockptr(upper->eb, slot);
2731 BUG_ON(bytenr != node->bytenr);
2733 if (node->eb->start == bytenr)
2737 blocksize = root->nodesize;
2738 generation = btrfs_node_ptr_generation(upper->eb, slot);
2739 eb = read_tree_block(root, bytenr, generation);
2743 } else if (!extent_buffer_uptodate(eb)) {
2744 free_extent_buffer(eb);
2748 btrfs_tree_lock(eb);
2749 btrfs_set_lock_blocking(eb);
2752 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2754 btrfs_tree_unlock(eb);
2755 free_extent_buffer(eb);
2760 BUG_ON(node->eb != eb);
2762 btrfs_set_node_blockptr(upper->eb, slot,
2764 btrfs_set_node_ptr_generation(upper->eb, slot,
2766 btrfs_mark_buffer_dirty(upper->eb);
2768 ret = btrfs_inc_extent_ref(trans, root,
2769 node->eb->start, blocksize,
2771 btrfs_header_owner(upper->eb),
2775 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2779 if (!upper->pending)
2780 drop_node_buffer(upper);
2782 unlock_node_buffer(upper);
2787 if (!err && node->pending) {
2788 drop_node_buffer(node);
2789 list_move_tail(&node->list, &rc->backref_cache.changed);
2793 path->lowest_level = 0;
2794 BUG_ON(err == -ENOSPC);
2798 static int link_to_upper(struct btrfs_trans_handle *trans,
2799 struct reloc_control *rc,
2800 struct backref_node *node,
2801 struct btrfs_path *path)
2803 struct btrfs_key key;
2805 btrfs_node_key_to_cpu(node->eb, &key, 0);
2806 return do_relocation(trans, rc, node, &key, path, 0);
2809 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2810 struct reloc_control *rc,
2811 struct btrfs_path *path, int err)
2814 struct backref_cache *cache = &rc->backref_cache;
2815 struct backref_node *node;
2819 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2820 while (!list_empty(&cache->pending[level])) {
2821 node = list_entry(cache->pending[level].next,
2822 struct backref_node, list);
2823 list_move_tail(&node->list, &list);
2824 BUG_ON(!node->pending);
2827 ret = link_to_upper(trans, rc, node, path);
2832 list_splice_init(&list, &cache->pending[level]);
2837 static void mark_block_processed(struct reloc_control *rc,
2838 u64 bytenr, u32 blocksize)
2840 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2844 static void __mark_block_processed(struct reloc_control *rc,
2845 struct backref_node *node)
2848 if (node->level == 0 ||
2849 in_block_group(node->bytenr, rc->block_group)) {
2850 blocksize = rc->extent_root->nodesize;
2851 mark_block_processed(rc, node->bytenr, blocksize);
2853 node->processed = 1;
2857 * mark a block and all blocks directly/indirectly reference the block
2860 static void update_processed_blocks(struct reloc_control *rc,
2861 struct backref_node *node)
2863 struct backref_node *next = node;
2864 struct backref_edge *edge;
2865 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2871 if (next->processed)
2874 __mark_block_processed(rc, next);
2876 if (list_empty(&next->upper))
2879 edge = list_entry(next->upper.next,
2880 struct backref_edge, list[LOWER]);
2881 edges[index++] = edge;
2882 next = edge->node[UPPER];
2884 next = walk_down_backref(edges, &index);
2888 static int tree_block_processed(u64 bytenr, struct reloc_control *rc)
2890 u32 blocksize = rc->extent_root->nodesize;
2892 if (test_range_bit(&rc->processed_blocks, bytenr,
2893 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2898 static int get_tree_block_key(struct reloc_control *rc,
2899 struct tree_block *block)
2901 struct extent_buffer *eb;
2903 BUG_ON(block->key_ready);
2904 eb = read_tree_block(rc->extent_root, block->bytenr,
2908 } else if (!extent_buffer_uptodate(eb)) {
2909 free_extent_buffer(eb);
2912 WARN_ON(btrfs_header_level(eb) != block->level);
2913 if (block->level == 0)
2914 btrfs_item_key_to_cpu(eb, &block->key, 0);
2916 btrfs_node_key_to_cpu(eb, &block->key, 0);
2917 free_extent_buffer(eb);
2918 block->key_ready = 1;
2923 * helper function to relocate a tree block
2925 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2926 struct reloc_control *rc,
2927 struct backref_node *node,
2928 struct btrfs_key *key,
2929 struct btrfs_path *path)
2931 struct btrfs_root *root;
2937 BUG_ON(node->processed);
2938 root = select_one_root(node);
2939 if (root == ERR_PTR(-ENOENT)) {
2940 update_processed_blocks(rc, node);
2944 if (!root || test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2945 ret = reserve_metadata_space(trans, rc, node);
2951 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2952 BUG_ON(node->new_bytenr);
2953 BUG_ON(!list_empty(&node->list));
2954 btrfs_record_root_in_trans(trans, root);
2955 root = root->reloc_root;
2956 node->new_bytenr = root->node->start;
2958 list_add_tail(&node->list, &rc->backref_cache.changed);
2960 path->lowest_level = node->level;
2961 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2962 btrfs_release_path(path);
2967 update_processed_blocks(rc, node);
2969 ret = do_relocation(trans, rc, node, key, path, 1);
2972 if (ret || node->level == 0 || node->cowonly)
2973 remove_backref_node(&rc->backref_cache, node);
2978 * relocate a list of blocks
2980 static noinline_for_stack
2981 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2982 struct reloc_control *rc, struct rb_root *blocks)
2984 struct backref_node *node;
2985 struct btrfs_path *path;
2986 struct tree_block *block;
2987 struct rb_node *rb_node;
2991 path = btrfs_alloc_path();
2994 goto out_free_blocks;
2997 rb_node = rb_first(blocks);
2999 block = rb_entry(rb_node, struct tree_block, rb_node);
3000 if (!block->key_ready)
3001 readahead_tree_block(rc->extent_root, block->bytenr);
3002 rb_node = rb_next(rb_node);
3005 rb_node = rb_first(blocks);
3007 block = rb_entry(rb_node, struct tree_block, rb_node);
3008 if (!block->key_ready) {
3009 err = get_tree_block_key(rc, block);
3013 rb_node = rb_next(rb_node);
3016 rb_node = rb_first(blocks);
3018 block = rb_entry(rb_node, struct tree_block, rb_node);
3020 node = build_backref_tree(rc, &block->key,
3021 block->level, block->bytenr);
3023 err = PTR_ERR(node);
3027 ret = relocate_tree_block(trans, rc, node, &block->key,
3030 if (ret != -EAGAIN || rb_node == rb_first(blocks))
3034 rb_node = rb_next(rb_node);
3037 err = finish_pending_nodes(trans, rc, path, err);
3040 btrfs_free_path(path);
3042 free_block_list(blocks);
3046 static noinline_for_stack
3047 int prealloc_file_extent_cluster(struct inode *inode,
3048 struct file_extent_cluster *cluster)
3053 u64 offset = BTRFS_I(inode)->index_cnt;
3057 u64 prealloc_start = cluster->start - offset;
3058 u64 prealloc_end = cluster->end - offset;
3061 BUG_ON(cluster->start != cluster->boundary[0]);
3064 ret = btrfs_check_data_free_space(inode, prealloc_start,
3065 prealloc_end + 1 - prealloc_start);
3069 cur_offset = prealloc_start;
3070 while (nr < cluster->nr) {
3071 start = cluster->boundary[nr] - offset;
3072 if (nr + 1 < cluster->nr)
3073 end = cluster->boundary[nr + 1] - 1 - offset;
3075 end = cluster->end - offset;
3077 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3078 num_bytes = end + 1 - start;
3079 if (cur_offset < start)
3080 btrfs_free_reserved_data_space(inode, cur_offset,
3081 start - cur_offset);
3082 ret = btrfs_prealloc_file_range(inode, 0, start,
3083 num_bytes, num_bytes,
3084 end + 1, &alloc_hint);
3085 cur_offset = end + 1;
3086 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3091 if (cur_offset < prealloc_end)
3092 btrfs_free_reserved_data_space(inode, cur_offset,
3093 prealloc_end + 1 - cur_offset);
3095 inode_unlock(inode);
3099 static noinline_for_stack
3100 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3103 struct btrfs_root *root = BTRFS_I(inode)->root;
3104 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3105 struct extent_map *em;
3108 em = alloc_extent_map();
3113 em->len = end + 1 - start;
3114 em->block_len = em->len;
3115 em->block_start = block_start;
3116 em->bdev = root->fs_info->fs_devices->latest_bdev;
3117 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3119 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3121 write_lock(&em_tree->lock);
3122 ret = add_extent_mapping(em_tree, em, 0);
3123 write_unlock(&em_tree->lock);
3124 if (ret != -EEXIST) {
3125 free_extent_map(em);
3128 btrfs_drop_extent_cache(inode, start, end, 0);
3130 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3134 static int relocate_file_extent_cluster(struct inode *inode,
3135 struct file_extent_cluster *cluster)
3139 u64 offset = BTRFS_I(inode)->index_cnt;
3140 unsigned long index;
3141 unsigned long last_index;
3143 struct file_ra_state *ra;
3144 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3151 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3155 ret = prealloc_file_extent_cluster(inode, cluster);
3159 file_ra_state_init(ra, inode->i_mapping);
3161 ret = setup_extent_mapping(inode, cluster->start - offset,
3162 cluster->end - offset, cluster->start);
3166 index = (cluster->start - offset) >> PAGE_SHIFT;
3167 last_index = (cluster->end - offset) >> PAGE_SHIFT;
3168 while (index <= last_index) {
3169 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_SIZE);
3173 page = find_lock_page(inode->i_mapping, index);
3175 page_cache_sync_readahead(inode->i_mapping,
3177 last_index + 1 - index);
3178 page = find_or_create_page(inode->i_mapping, index,
3181 btrfs_delalloc_release_metadata(inode,
3188 if (PageReadahead(page)) {
3189 page_cache_async_readahead(inode->i_mapping,
3190 ra, NULL, page, index,
3191 last_index + 1 - index);
3194 if (!PageUptodate(page)) {
3195 btrfs_readpage(NULL, page);
3197 if (!PageUptodate(page)) {
3200 btrfs_delalloc_release_metadata(inode,
3207 page_start = page_offset(page);
3208 page_end = page_start + PAGE_SIZE - 1;
3210 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3212 set_page_extent_mapped(page);
3214 if (nr < cluster->nr &&
3215 page_start + offset == cluster->boundary[nr]) {
3216 set_extent_bits(&BTRFS_I(inode)->io_tree,
3217 page_start, page_end,
3222 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL, 0);
3223 set_page_dirty(page);
3225 unlock_extent(&BTRFS_I(inode)->io_tree,
3226 page_start, page_end);
3231 balance_dirty_pages_ratelimited(inode->i_mapping);
3232 btrfs_throttle(BTRFS_I(inode)->root);
3234 WARN_ON(nr != cluster->nr);
3240 static noinline_for_stack
3241 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3242 struct file_extent_cluster *cluster)
3246 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3247 ret = relocate_file_extent_cluster(inode, cluster);
3254 cluster->start = extent_key->objectid;
3256 BUG_ON(cluster->nr >= MAX_EXTENTS);
3257 cluster->end = extent_key->objectid + extent_key->offset - 1;
3258 cluster->boundary[cluster->nr] = extent_key->objectid;
3261 if (cluster->nr >= MAX_EXTENTS) {
3262 ret = relocate_file_extent_cluster(inode, cluster);
3270 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3271 static int get_ref_objectid_v0(struct reloc_control *rc,
3272 struct btrfs_path *path,
3273 struct btrfs_key *extent_key,
3274 u64 *ref_objectid, int *path_change)
3276 struct btrfs_key key;
3277 struct extent_buffer *leaf;
3278 struct btrfs_extent_ref_v0 *ref0;
3282 leaf = path->nodes[0];
3283 slot = path->slots[0];
3285 if (slot >= btrfs_header_nritems(leaf)) {
3286 ret = btrfs_next_leaf(rc->extent_root, path);
3290 leaf = path->nodes[0];
3291 slot = path->slots[0];
3295 btrfs_item_key_to_cpu(leaf, &key, slot);
3296 if (key.objectid != extent_key->objectid)
3299 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3303 ref0 = btrfs_item_ptr(leaf, slot,
3304 struct btrfs_extent_ref_v0);
3305 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3313 * helper to add a tree block to the list.
3314 * the major work is getting the generation and level of the block
3316 static int add_tree_block(struct reloc_control *rc,
3317 struct btrfs_key *extent_key,
3318 struct btrfs_path *path,
3319 struct rb_root *blocks)
3321 struct extent_buffer *eb;
3322 struct btrfs_extent_item *ei;
3323 struct btrfs_tree_block_info *bi;
3324 struct tree_block *block;
3325 struct rb_node *rb_node;
3330 eb = path->nodes[0];
3331 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3333 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3334 item_size >= sizeof(*ei) + sizeof(*bi)) {
3335 ei = btrfs_item_ptr(eb, path->slots[0],
3336 struct btrfs_extent_item);
3337 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3338 bi = (struct btrfs_tree_block_info *)(ei + 1);
3339 level = btrfs_tree_block_level(eb, bi);
3341 level = (int)extent_key->offset;
3343 generation = btrfs_extent_generation(eb, ei);
3345 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3349 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3350 ret = get_ref_objectid_v0(rc, path, extent_key,
3354 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3355 level = (int)ref_owner;
3356 /* FIXME: get real generation */
3363 btrfs_release_path(path);
3365 BUG_ON(level == -1);
3367 block = kmalloc(sizeof(*block), GFP_NOFS);
3371 block->bytenr = extent_key->objectid;
3372 block->key.objectid = rc->extent_root->nodesize;
3373 block->key.offset = generation;
3374 block->level = level;
3375 block->key_ready = 0;
3377 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3379 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3385 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3387 static int __add_tree_block(struct reloc_control *rc,
3388 u64 bytenr, u32 blocksize,
3389 struct rb_root *blocks)
3391 struct btrfs_path *path;
3392 struct btrfs_key key;
3394 bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info,
3397 if (tree_block_processed(bytenr, rc))
3400 if (tree_search(blocks, bytenr))
3403 path = btrfs_alloc_path();
3407 key.objectid = bytenr;
3409 key.type = BTRFS_METADATA_ITEM_KEY;
3410 key.offset = (u64)-1;
3412 key.type = BTRFS_EXTENT_ITEM_KEY;
3413 key.offset = blocksize;
3416 path->search_commit_root = 1;
3417 path->skip_locking = 1;
3418 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3422 if (ret > 0 && skinny) {
3423 if (path->slots[0]) {
3425 btrfs_item_key_to_cpu(path->nodes[0], &key,
3427 if (key.objectid == bytenr &&
3428 (key.type == BTRFS_METADATA_ITEM_KEY ||
3429 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3430 key.offset == blocksize)))
3436 btrfs_release_path(path);
3442 ret = add_tree_block(rc, &key, path, blocks);
3444 btrfs_free_path(path);
3449 * helper to check if the block use full backrefs for pointers in it
3451 static int block_use_full_backref(struct reloc_control *rc,
3452 struct extent_buffer *eb)
3457 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3458 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3461 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3462 eb->start, btrfs_header_level(eb), 1,
3466 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3473 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3474 struct btrfs_block_group_cache *block_group,
3475 struct inode *inode,
3478 struct btrfs_key key;
3479 struct btrfs_root *root = fs_info->tree_root;
3480 struct btrfs_trans_handle *trans;
3487 key.type = BTRFS_INODE_ITEM_KEY;
3490 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3491 if (IS_ERR(inode) || is_bad_inode(inode)) {
3498 ret = btrfs_check_trunc_cache_free_space(root,
3499 &fs_info->global_block_rsv);
3503 trans = btrfs_join_transaction(root);
3504 if (IS_ERR(trans)) {
3505 ret = PTR_ERR(trans);
3509 ret = btrfs_truncate_free_space_cache(root, trans, block_group, inode);
3511 btrfs_end_transaction(trans, root);
3512 btrfs_btree_balance_dirty(root);
3519 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3520 * this function scans fs tree to find blocks reference the data extent
3522 static int find_data_references(struct reloc_control *rc,
3523 struct btrfs_key *extent_key,
3524 struct extent_buffer *leaf,
3525 struct btrfs_extent_data_ref *ref,
3526 struct rb_root *blocks)
3528 struct btrfs_path *path;
3529 struct tree_block *block;
3530 struct btrfs_root *root;
3531 struct btrfs_file_extent_item *fi;
3532 struct rb_node *rb_node;
3533 struct btrfs_key key;
3544 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3545 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3546 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3547 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3550 * This is an extent belonging to the free space cache, lets just delete
3551 * it and redo the search.
3553 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3554 ret = delete_block_group_cache(rc->extent_root->fs_info,
3556 NULL, ref_objectid);
3562 path = btrfs_alloc_path();
3565 path->reada = READA_FORWARD;
3567 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3569 err = PTR_ERR(root);
3573 key.objectid = ref_objectid;
3574 key.type = BTRFS_EXTENT_DATA_KEY;
3575 if (ref_offset > ((u64)-1 << 32))
3578 key.offset = ref_offset;
3580 path->search_commit_root = 1;
3581 path->skip_locking = 1;
3582 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3588 leaf = path->nodes[0];
3589 nritems = btrfs_header_nritems(leaf);
3591 * the references in tree blocks that use full backrefs
3592 * are not counted in
3594 if (block_use_full_backref(rc, leaf))
3598 rb_node = tree_search(blocks, leaf->start);
3603 path->slots[0] = nritems;
3606 while (ref_count > 0) {
3607 while (path->slots[0] >= nritems) {
3608 ret = btrfs_next_leaf(root, path);
3613 if (WARN_ON(ret > 0))
3616 leaf = path->nodes[0];
3617 nritems = btrfs_header_nritems(leaf);
3620 if (block_use_full_backref(rc, leaf))
3624 rb_node = tree_search(blocks, leaf->start);
3629 path->slots[0] = nritems;
3633 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3634 if (WARN_ON(key.objectid != ref_objectid ||
3635 key.type != BTRFS_EXTENT_DATA_KEY))
3638 fi = btrfs_item_ptr(leaf, path->slots[0],
3639 struct btrfs_file_extent_item);
3641 if (btrfs_file_extent_type(leaf, fi) ==
3642 BTRFS_FILE_EXTENT_INLINE)
3645 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3646 extent_key->objectid)
3649 key.offset -= btrfs_file_extent_offset(leaf, fi);
3650 if (key.offset != ref_offset)
3658 if (!tree_block_processed(leaf->start, rc)) {
3659 block = kmalloc(sizeof(*block), GFP_NOFS);
3664 block->bytenr = leaf->start;
3665 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3667 block->key_ready = 1;
3668 rb_node = tree_insert(blocks, block->bytenr,
3671 backref_tree_panic(rb_node, -EEXIST,
3677 path->slots[0] = nritems;
3683 btrfs_free_path(path);
3688 * helper to find all tree blocks that reference a given data extent
3690 static noinline_for_stack
3691 int add_data_references(struct reloc_control *rc,
3692 struct btrfs_key *extent_key,
3693 struct btrfs_path *path,
3694 struct rb_root *blocks)
3696 struct btrfs_key key;
3697 struct extent_buffer *eb;
3698 struct btrfs_extent_data_ref *dref;
3699 struct btrfs_extent_inline_ref *iref;
3702 u32 blocksize = rc->extent_root->nodesize;
3706 eb = path->nodes[0];
3707 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3708 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3709 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3710 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3714 ptr += sizeof(struct btrfs_extent_item);
3717 iref = (struct btrfs_extent_inline_ref *)ptr;
3718 key.type = btrfs_extent_inline_ref_type(eb, iref);
3719 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3720 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3721 ret = __add_tree_block(rc, key.offset, blocksize,
3723 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3724 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3725 ret = find_data_references(rc, extent_key,
3734 ptr += btrfs_extent_inline_ref_size(key.type);
3740 eb = path->nodes[0];
3741 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3742 ret = btrfs_next_leaf(rc->extent_root, path);
3749 eb = path->nodes[0];
3752 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3753 if (key.objectid != extent_key->objectid)
3756 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3757 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3758 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3760 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3761 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3763 ret = __add_tree_block(rc, key.offset, blocksize,
3765 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3766 dref = btrfs_item_ptr(eb, path->slots[0],
3767 struct btrfs_extent_data_ref);
3768 ret = find_data_references(rc, extent_key,
3780 btrfs_release_path(path);
3782 free_block_list(blocks);
3787 * helper to find next unprocessed extent
3789 static noinline_for_stack
3790 int find_next_extent(struct reloc_control *rc, struct btrfs_path *path,
3791 struct btrfs_key *extent_key)
3793 struct btrfs_key key;
3794 struct extent_buffer *leaf;
3795 u64 start, end, last;
3798 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3801 if (rc->search_start >= last) {
3806 key.objectid = rc->search_start;
3807 key.type = BTRFS_EXTENT_ITEM_KEY;
3810 path->search_commit_root = 1;
3811 path->skip_locking = 1;
3812 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3817 leaf = path->nodes[0];
3818 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3819 ret = btrfs_next_leaf(rc->extent_root, path);
3822 leaf = path->nodes[0];
3825 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3826 if (key.objectid >= last) {
3831 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3832 key.type != BTRFS_METADATA_ITEM_KEY) {
3837 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3838 key.objectid + key.offset <= rc->search_start) {
3843 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3844 key.objectid + rc->extent_root->nodesize <=
3850 ret = find_first_extent_bit(&rc->processed_blocks,
3851 key.objectid, &start, &end,
3852 EXTENT_DIRTY, NULL);
3854 if (ret == 0 && start <= key.objectid) {
3855 btrfs_release_path(path);
3856 rc->search_start = end + 1;
3858 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3859 rc->search_start = key.objectid + key.offset;
3861 rc->search_start = key.objectid +
3862 rc->extent_root->nodesize;
3863 memcpy(extent_key, &key, sizeof(key));
3867 btrfs_release_path(path);
3871 static void set_reloc_control(struct reloc_control *rc)
3873 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3875 mutex_lock(&fs_info->reloc_mutex);
3876 fs_info->reloc_ctl = rc;
3877 mutex_unlock(&fs_info->reloc_mutex);
3880 static void unset_reloc_control(struct reloc_control *rc)
3882 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3884 mutex_lock(&fs_info->reloc_mutex);
3885 fs_info->reloc_ctl = NULL;
3886 mutex_unlock(&fs_info->reloc_mutex);
3889 static int check_extent_flags(u64 flags)
3891 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3892 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3894 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3895 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3897 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3898 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3903 static noinline_for_stack
3904 int prepare_to_relocate(struct reloc_control *rc)
3906 struct btrfs_trans_handle *trans;
3909 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3910 BTRFS_BLOCK_RSV_TEMP);
3914 memset(&rc->cluster, 0, sizeof(rc->cluster));
3915 rc->search_start = rc->block_group->key.objectid;
3916 rc->extents_found = 0;
3917 rc->nodes_relocated = 0;
3918 rc->merging_rsv_size = 0;
3919 rc->reserved_bytes = 0;
3920 rc->block_rsv->size = rc->extent_root->nodesize *
3921 RELOCATION_RESERVED_NODES;
3922 ret = btrfs_block_rsv_refill(rc->extent_root,
3923 rc->block_rsv, rc->block_rsv->size,
3924 BTRFS_RESERVE_FLUSH_ALL);
3928 rc->create_reloc_tree = 1;
3929 set_reloc_control(rc);
3931 trans = btrfs_join_transaction(rc->extent_root);
3932 if (IS_ERR(trans)) {
3933 unset_reloc_control(rc);
3935 * extent tree is not a ref_cow tree and has no reloc_root to
3936 * cleanup. And callers are responsible to free the above
3939 return PTR_ERR(trans);
3941 btrfs_commit_transaction(trans, rc->extent_root);
3946 * Qgroup fixer for data chunk relocation.
3947 * The data relocation is done in the following steps
3948 * 1) Copy data extents into data reloc tree
3949 * 2) Create tree reloc tree(special snapshot) for related subvolumes
3950 * 3) Modify file extents in tree reloc tree
3951 * 4) Merge tree reloc tree with original fs tree, by swapping tree blocks
3953 * The problem is, data and tree reloc tree are not accounted to qgroup,
3954 * and 4) will only info qgroup to track tree blocks change, not file extents
3955 * in the tree blocks.
3957 * The good news is, related data extents are all in data reloc tree, so we
3958 * only need to info qgroup to track all file extents in data reloc tree
3959 * before commit trans.
3961 static int qgroup_fix_relocated_data_extents(struct btrfs_trans_handle *trans,
3962 struct reloc_control *rc)
3964 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3965 struct inode *inode = rc->data_inode;
3966 struct btrfs_root *data_reloc_root = BTRFS_I(inode)->root;
3967 struct btrfs_path *path;
3968 struct btrfs_key key;
3971 if (!test_bit(BTRFS_FS_QUOTA_ENABLED, &fs_info->flags))
3975 * Only for stage where we update data pointers the qgroup fix is
3977 * For MOVING_DATA stage, we will miss the timing of swapping tree
3978 * blocks, and won't fix it.
3980 if (!(rc->stage == UPDATE_DATA_PTRS && rc->extents_found))
3983 path = btrfs_alloc_path();
3986 key.objectid = btrfs_ino(inode);
3987 key.type = BTRFS_EXTENT_DATA_KEY;
3990 ret = btrfs_search_slot(NULL, data_reloc_root, &key, path, 0, 0);
3994 lock_extent(&BTRFS_I(inode)->io_tree, 0, (u64)-1);
3996 struct btrfs_file_extent_item *fi;
3998 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3999 if (key.objectid > btrfs_ino(inode))
4001 if (key.type != BTRFS_EXTENT_DATA_KEY)
4003 fi = btrfs_item_ptr(path->nodes[0], path->slots[0],
4004 struct btrfs_file_extent_item);
4005 if (btrfs_file_extent_type(path->nodes[0], fi) !=
4006 BTRFS_FILE_EXTENT_REG)
4008 ret = btrfs_qgroup_insert_dirty_extent(trans, fs_info,
4009 btrfs_file_extent_disk_bytenr(path->nodes[0], fi),
4010 btrfs_file_extent_disk_num_bytes(path->nodes[0], fi),
4015 ret = btrfs_next_item(data_reloc_root, path);
4023 unlock_extent(&BTRFS_I(inode)->io_tree, 0 , (u64)-1);
4025 btrfs_free_path(path);
4029 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
4031 struct rb_root blocks = RB_ROOT;
4032 struct btrfs_key key;
4033 struct btrfs_trans_handle *trans = NULL;
4034 struct btrfs_path *path;
4035 struct btrfs_extent_item *ei;
4042 path = btrfs_alloc_path();
4045 path->reada = READA_FORWARD;
4047 ret = prepare_to_relocate(rc);
4054 rc->reserved_bytes = 0;
4055 ret = btrfs_block_rsv_refill(rc->extent_root,
4056 rc->block_rsv, rc->block_rsv->size,
4057 BTRFS_RESERVE_FLUSH_ALL);
4063 trans = btrfs_start_transaction(rc->extent_root, 0);
4064 if (IS_ERR(trans)) {
4065 err = PTR_ERR(trans);
4070 if (update_backref_cache(trans, &rc->backref_cache)) {
4071 btrfs_end_transaction(trans, rc->extent_root);
4075 ret = find_next_extent(rc, path, &key);
4081 rc->extents_found++;
4083 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
4084 struct btrfs_extent_item);
4085 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
4086 if (item_size >= sizeof(*ei)) {
4087 flags = btrfs_extent_flags(path->nodes[0], ei);
4088 ret = check_extent_flags(flags);
4092 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
4094 int path_change = 0;
4097 sizeof(struct btrfs_extent_item_v0));
4098 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
4104 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
4105 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
4107 flags = BTRFS_EXTENT_FLAG_DATA;
4110 btrfs_release_path(path);
4112 path->search_commit_root = 1;
4113 path->skip_locking = 1;
4114 ret = btrfs_search_slot(NULL, rc->extent_root,
4127 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
4128 ret = add_tree_block(rc, &key, path, &blocks);
4129 } else if (rc->stage == UPDATE_DATA_PTRS &&
4130 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4131 ret = add_data_references(rc, &key, path, &blocks);
4133 btrfs_release_path(path);
4141 if (!RB_EMPTY_ROOT(&blocks)) {
4142 ret = relocate_tree_blocks(trans, rc, &blocks);
4145 * if we fail to relocate tree blocks, force to update
4146 * backref cache when committing transaction.
4148 rc->backref_cache.last_trans = trans->transid - 1;
4150 if (ret != -EAGAIN) {
4154 rc->extents_found--;
4155 rc->search_start = key.objectid;
4159 btrfs_end_transaction_throttle(trans, rc->extent_root);
4160 btrfs_btree_balance_dirty(rc->extent_root);
4163 if (rc->stage == MOVE_DATA_EXTENTS &&
4164 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4165 rc->found_file_extent = 1;
4166 ret = relocate_data_extent(rc->data_inode,
4167 &key, &rc->cluster);
4174 if (trans && progress && err == -ENOSPC) {
4175 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
4176 rc->block_group->flags);
4184 btrfs_release_path(path);
4185 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY);
4188 btrfs_end_transaction_throttle(trans, rc->extent_root);
4189 btrfs_btree_balance_dirty(rc->extent_root);
4193 ret = relocate_file_extent_cluster(rc->data_inode,
4199 rc->create_reloc_tree = 0;
4200 set_reloc_control(rc);
4202 backref_cache_cleanup(&rc->backref_cache);
4203 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4205 err = prepare_to_merge(rc, err);
4207 merge_reloc_roots(rc);
4209 rc->merge_reloc_tree = 0;
4210 unset_reloc_control(rc);
4211 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
4213 /* get rid of pinned extents */
4214 trans = btrfs_join_transaction(rc->extent_root);
4215 if (IS_ERR(trans)) {
4216 err = PTR_ERR(trans);
4219 ret = qgroup_fix_relocated_data_extents(trans, rc);
4221 btrfs_abort_transaction(trans, ret);
4226 btrfs_commit_transaction(trans, rc->extent_root);
4228 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4229 btrfs_free_path(path);
4233 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4234 struct btrfs_root *root, u64 objectid)
4236 struct btrfs_path *path;
4237 struct btrfs_inode_item *item;
4238 struct extent_buffer *leaf;
4241 path = btrfs_alloc_path();
4245 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4249 leaf = path->nodes[0];
4250 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4251 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4252 btrfs_set_inode_generation(leaf, item, 1);
4253 btrfs_set_inode_size(leaf, item, 0);
4254 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4255 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4256 BTRFS_INODE_PREALLOC);
4257 btrfs_mark_buffer_dirty(leaf);
4259 btrfs_free_path(path);
4264 * helper to create inode for data relocation.
4265 * the inode is in data relocation tree and its link count is 0
4267 static noinline_for_stack
4268 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4269 struct btrfs_block_group_cache *group)
4271 struct inode *inode = NULL;
4272 struct btrfs_trans_handle *trans;
4273 struct btrfs_root *root;
4274 struct btrfs_key key;
4278 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4280 return ERR_CAST(root);
4282 trans = btrfs_start_transaction(root, 6);
4284 return ERR_CAST(trans);
4286 err = btrfs_find_free_objectid(root, &objectid);
4290 err = __insert_orphan_inode(trans, root, objectid);
4293 key.objectid = objectid;
4294 key.type = BTRFS_INODE_ITEM_KEY;
4296 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4297 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4298 BTRFS_I(inode)->index_cnt = group->key.objectid;
4300 err = btrfs_orphan_add(trans, inode);
4302 btrfs_end_transaction(trans, root);
4303 btrfs_btree_balance_dirty(root);
4307 inode = ERR_PTR(err);
4312 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4314 struct reloc_control *rc;
4316 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4320 INIT_LIST_HEAD(&rc->reloc_roots);
4321 backref_cache_init(&rc->backref_cache);
4322 mapping_tree_init(&rc->reloc_root_tree);
4323 extent_io_tree_init(&rc->processed_blocks,
4324 fs_info->btree_inode->i_mapping);
4329 * function to relocate all extents in a block group.
4331 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4333 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4334 struct reloc_control *rc;
4335 struct inode *inode;
4336 struct btrfs_path *path;
4341 rc = alloc_reloc_control(fs_info);
4345 rc->extent_root = extent_root;
4347 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4348 BUG_ON(!rc->block_group);
4350 ret = btrfs_inc_block_group_ro(extent_root, rc->block_group);
4357 path = btrfs_alloc_path();
4363 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4365 btrfs_free_path(path);
4368 ret = delete_block_group_cache(fs_info, rc->block_group, inode, 0);
4370 ret = PTR_ERR(inode);
4372 if (ret && ret != -ENOENT) {
4377 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4378 if (IS_ERR(rc->data_inode)) {
4379 err = PTR_ERR(rc->data_inode);
4380 rc->data_inode = NULL;
4384 btrfs_info(extent_root->fs_info,
4385 "relocating block group %llu flags %llu",
4386 rc->block_group->key.objectid, rc->block_group->flags);
4388 btrfs_wait_block_group_reservations(rc->block_group);
4389 btrfs_wait_nocow_writers(rc->block_group);
4390 btrfs_wait_ordered_roots(fs_info, -1,
4391 rc->block_group->key.objectid,
4392 rc->block_group->key.offset);
4395 mutex_lock(&fs_info->cleaner_mutex);
4396 ret = relocate_block_group(rc);
4397 mutex_unlock(&fs_info->cleaner_mutex);
4403 if (rc->extents_found == 0)
4406 btrfs_info(extent_root->fs_info, "found %llu extents",
4409 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4410 ret = btrfs_wait_ordered_range(rc->data_inode, 0,
4416 invalidate_mapping_pages(rc->data_inode->i_mapping,
4418 rc->stage = UPDATE_DATA_PTRS;
4422 WARN_ON(rc->block_group->pinned > 0);
4423 WARN_ON(rc->block_group->reserved > 0);
4424 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4427 btrfs_dec_block_group_ro(extent_root, rc->block_group);
4428 iput(rc->data_inode);
4429 btrfs_put_block_group(rc->block_group);
4434 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4436 struct btrfs_trans_handle *trans;
4439 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4441 return PTR_ERR(trans);
4443 memset(&root->root_item.drop_progress, 0,
4444 sizeof(root->root_item.drop_progress));
4445 root->root_item.drop_level = 0;
4446 btrfs_set_root_refs(&root->root_item, 0);
4447 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4448 &root->root_key, &root->root_item);
4450 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4457 * recover relocation interrupted by system crash.
4459 * this function resumes merging reloc trees with corresponding fs trees.
4460 * this is important for keeping the sharing of tree blocks
4462 int btrfs_recover_relocation(struct btrfs_root *root)
4464 LIST_HEAD(reloc_roots);
4465 struct btrfs_key key;
4466 struct btrfs_root *fs_root;
4467 struct btrfs_root *reloc_root;
4468 struct btrfs_path *path;
4469 struct extent_buffer *leaf;
4470 struct reloc_control *rc = NULL;
4471 struct btrfs_trans_handle *trans;
4475 path = btrfs_alloc_path();
4478 path->reada = READA_BACK;
4480 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4481 key.type = BTRFS_ROOT_ITEM_KEY;
4482 key.offset = (u64)-1;
4485 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4492 if (path->slots[0] == 0)
4496 leaf = path->nodes[0];
4497 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4498 btrfs_release_path(path);
4500 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4501 key.type != BTRFS_ROOT_ITEM_KEY)
4504 reloc_root = btrfs_read_fs_root(root, &key);
4505 if (IS_ERR(reloc_root)) {
4506 err = PTR_ERR(reloc_root);
4510 list_add(&reloc_root->root_list, &reloc_roots);
4512 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4513 fs_root = read_fs_root(root->fs_info,
4514 reloc_root->root_key.offset);
4515 if (IS_ERR(fs_root)) {
4516 ret = PTR_ERR(fs_root);
4517 if (ret != -ENOENT) {
4521 ret = mark_garbage_root(reloc_root);
4529 if (key.offset == 0)
4534 btrfs_release_path(path);
4536 if (list_empty(&reloc_roots))
4539 rc = alloc_reloc_control(root->fs_info);
4545 rc->extent_root = root->fs_info->extent_root;
4547 set_reloc_control(rc);
4549 trans = btrfs_join_transaction(rc->extent_root);
4550 if (IS_ERR(trans)) {
4551 unset_reloc_control(rc);
4552 err = PTR_ERR(trans);
4556 rc->merge_reloc_tree = 1;
4558 while (!list_empty(&reloc_roots)) {
4559 reloc_root = list_entry(reloc_roots.next,
4560 struct btrfs_root, root_list);
4561 list_del(&reloc_root->root_list);
4563 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4564 list_add_tail(&reloc_root->root_list,
4569 fs_root = read_fs_root(root->fs_info,
4570 reloc_root->root_key.offset);
4571 if (IS_ERR(fs_root)) {
4572 err = PTR_ERR(fs_root);
4576 err = __add_reloc_root(reloc_root);
4577 BUG_ON(err < 0); /* -ENOMEM or logic error */
4578 fs_root->reloc_root = reloc_root;
4581 err = btrfs_commit_transaction(trans, rc->extent_root);
4585 merge_reloc_roots(rc);
4587 unset_reloc_control(rc);
4589 trans = btrfs_join_transaction(rc->extent_root);
4590 if (IS_ERR(trans)) {
4591 err = PTR_ERR(trans);
4594 err = qgroup_fix_relocated_data_extents(trans, rc);
4596 btrfs_abort_transaction(trans, err);
4599 err = btrfs_commit_transaction(trans, rc->extent_root);
4603 if (!list_empty(&reloc_roots))
4604 free_reloc_roots(&reloc_roots);
4606 btrfs_free_path(path);
4609 /* cleanup orphan inode in data relocation tree */
4610 fs_root = read_fs_root(root->fs_info,
4611 BTRFS_DATA_RELOC_TREE_OBJECTID);
4612 if (IS_ERR(fs_root))
4613 err = PTR_ERR(fs_root);
4615 err = btrfs_orphan_cleanup(fs_root);
4621 * helper to add ordered checksum for data relocation.
4623 * cloning checksum properly handles the nodatasum extents.
4624 * it also saves CPU time to re-calculate the checksum.
4626 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4628 struct btrfs_ordered_sum *sums;
4629 struct btrfs_ordered_extent *ordered;
4630 struct btrfs_root *root = BTRFS_I(inode)->root;
4636 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4637 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4639 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4640 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4641 disk_bytenr + len - 1, &list, 0);
4645 while (!list_empty(&list)) {
4646 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4647 list_del_init(&sums->list);
4650 * We need to offset the new_bytenr based on where the csum is.
4651 * We need to do this because we will read in entire prealloc
4652 * extents but we may have written to say the middle of the
4653 * prealloc extent, so we need to make sure the csum goes with
4654 * the right disk offset.
4656 * We can do this because the data reloc inode refers strictly
4657 * to the on disk bytes, so we don't have to worry about
4658 * disk_len vs real len like with real inodes since it's all
4661 new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
4662 sums->bytenr = new_bytenr;
4664 btrfs_add_ordered_sum(inode, ordered, sums);
4667 btrfs_put_ordered_extent(ordered);
4671 int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4672 struct btrfs_root *root, struct extent_buffer *buf,
4673 struct extent_buffer *cow)
4675 struct reloc_control *rc;
4676 struct backref_node *node;
4681 rc = root->fs_info->reloc_ctl;
4685 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4686 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4688 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
4689 if (buf == root->node)
4690 __update_reloc_root(root, cow->start);
4693 level = btrfs_header_level(buf);
4694 if (btrfs_header_generation(buf) <=
4695 btrfs_root_last_snapshot(&root->root_item))
4698 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4699 rc->create_reloc_tree) {
4700 WARN_ON(!first_cow && level == 0);
4702 node = rc->backref_cache.path[level];
4703 BUG_ON(node->bytenr != buf->start &&
4704 node->new_bytenr != buf->start);
4706 drop_node_buffer(node);
4707 extent_buffer_get(cow);
4709 node->new_bytenr = cow->start;
4711 if (!node->pending) {
4712 list_move_tail(&node->list,
4713 &rc->backref_cache.pending[level]);
4718 __mark_block_processed(rc, node);
4720 if (first_cow && level > 0)
4721 rc->nodes_relocated += buf->len;
4724 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
4725 ret = replace_file_extents(trans, rc, root, cow);
4730 * called before creating snapshot. it calculates metadata reservation
4731 * required for relocating tree blocks in the snapshot
4733 void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
4734 u64 *bytes_to_reserve)
4736 struct btrfs_root *root;
4737 struct reloc_control *rc;
4739 root = pending->root;
4740 if (!root->reloc_root)
4743 rc = root->fs_info->reloc_ctl;
4744 if (!rc->merge_reloc_tree)
4747 root = root->reloc_root;
4748 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4750 * relocation is in the stage of merging trees. the space
4751 * used by merging a reloc tree is twice the size of
4752 * relocated tree nodes in the worst case. half for cowing
4753 * the reloc tree, half for cowing the fs tree. the space
4754 * used by cowing the reloc tree will be freed after the
4755 * tree is dropped. if we create snapshot, cowing the fs
4756 * tree may use more space than it frees. so we need
4757 * reserve extra space.
4759 *bytes_to_reserve += rc->nodes_relocated;
4763 * called after snapshot is created. migrate block reservation
4764 * and create reloc root for the newly created snapshot
4766 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4767 struct btrfs_pending_snapshot *pending)
4769 struct btrfs_root *root = pending->root;
4770 struct btrfs_root *reloc_root;
4771 struct btrfs_root *new_root;
4772 struct reloc_control *rc;
4775 if (!root->reloc_root)
4778 rc = root->fs_info->reloc_ctl;
4779 rc->merging_rsv_size += rc->nodes_relocated;
4781 if (rc->merge_reloc_tree) {
4782 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4784 rc->nodes_relocated, 1);
4789 new_root = pending->snap;
4790 reloc_root = create_reloc_root(trans, root->reloc_root,
4791 new_root->root_key.objectid);
4792 if (IS_ERR(reloc_root))
4793 return PTR_ERR(reloc_root);
4795 ret = __add_reloc_root(reloc_root);
4797 new_root->reloc_root = reloc_root;
4799 if (rc->create_reloc_tree)
4800 ret = clone_backref_node(trans, rc, root, reloc_root);