2 * Copyright (C) 2009 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
27 #include "transaction.h"
30 #include "btrfs_inode.h"
31 #include "async-thread.h"
32 #include "free-space-cache.h"
33 #include "inode-map.h"
36 * backref_node, mapping_node and tree_block start with this
39 struct rb_node rb_node;
44 * present a tree block in the backref cache
47 struct rb_node rb_node;
51 /* objectid of tree block owner, can be not uptodate */
53 /* link to pending, changed or detached list */
54 struct list_head list;
55 /* list of upper level blocks reference this block */
56 struct list_head upper;
57 /* list of child blocks in the cache */
58 struct list_head lower;
59 /* NULL if this node is not tree root */
60 struct btrfs_root *root;
61 /* extent buffer got by COW the block */
62 struct extent_buffer *eb;
63 /* level of tree block */
65 /* is the block in non-reference counted tree */
66 unsigned int cowonly:1;
67 /* 1 if no child node in the cache */
68 unsigned int lowest:1;
69 /* is the extent buffer locked */
70 unsigned int locked:1;
71 /* has the block been processed */
72 unsigned int processed:1;
73 /* have backrefs of this block been checked */
74 unsigned int checked:1;
76 * 1 if corresponding block has been cowed but some upper
77 * level block pointers may not point to the new location
79 unsigned int pending:1;
81 * 1 if the backref node isn't connected to any other
84 unsigned int detached:1;
88 * present a block pointer in the backref cache
91 struct list_head list[2];
92 struct backref_node *node[2];
98 struct backref_cache {
99 /* red black tree of all backref nodes in the cache */
100 struct rb_root rb_root;
101 /* for passing backref nodes to btrfs_reloc_cow_block */
102 struct backref_node *path[BTRFS_MAX_LEVEL];
104 * list of blocks that have been cowed but some block
105 * pointers in upper level blocks may not reflect the
108 struct list_head pending[BTRFS_MAX_LEVEL];
109 /* list of backref nodes with no child node */
110 struct list_head leaves;
111 /* list of blocks that have been cowed in current transaction */
112 struct list_head changed;
113 /* list of detached backref node. */
114 struct list_head detached;
123 * map address of tree root to tree
125 struct mapping_node {
126 struct rb_node rb_node;
131 struct mapping_tree {
132 struct rb_root rb_root;
137 * present a tree block to process
140 struct rb_node rb_node;
142 struct btrfs_key key;
143 unsigned int level:8;
144 unsigned int key_ready:1;
147 #define MAX_EXTENTS 128
149 struct file_extent_cluster {
152 u64 boundary[MAX_EXTENTS];
156 struct reloc_control {
157 /* block group to relocate */
158 struct btrfs_block_group_cache *block_group;
160 struct btrfs_root *extent_root;
161 /* inode for moving data */
162 struct inode *data_inode;
164 struct btrfs_block_rsv *block_rsv;
166 struct backref_cache backref_cache;
168 struct file_extent_cluster cluster;
169 /* tree blocks have been processed */
170 struct extent_io_tree processed_blocks;
171 /* map start of tree root to corresponding reloc tree */
172 struct mapping_tree reloc_root_tree;
173 /* list of reloc trees */
174 struct list_head reloc_roots;
175 /* size of metadata reservation for merging reloc trees */
176 u64 merging_rsv_size;
177 /* size of relocated tree nodes */
183 unsigned int stage:8;
184 unsigned int create_reloc_tree:1;
185 unsigned int merge_reloc_tree:1;
186 unsigned int found_file_extent:1;
187 unsigned int commit_transaction:1;
190 /* stages of data relocation */
191 #define MOVE_DATA_EXTENTS 0
192 #define UPDATE_DATA_PTRS 1
194 static void remove_backref_node(struct backref_cache *cache,
195 struct backref_node *node);
196 static void __mark_block_processed(struct reloc_control *rc,
197 struct backref_node *node);
199 static void mapping_tree_init(struct mapping_tree *tree)
201 tree->rb_root = RB_ROOT;
202 spin_lock_init(&tree->lock);
205 static void backref_cache_init(struct backref_cache *cache)
208 cache->rb_root = RB_ROOT;
209 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
210 INIT_LIST_HEAD(&cache->pending[i]);
211 INIT_LIST_HEAD(&cache->changed);
212 INIT_LIST_HEAD(&cache->detached);
213 INIT_LIST_HEAD(&cache->leaves);
216 static void backref_cache_cleanup(struct backref_cache *cache)
218 struct backref_node *node;
221 while (!list_empty(&cache->detached)) {
222 node = list_entry(cache->detached.next,
223 struct backref_node, list);
224 remove_backref_node(cache, node);
227 while (!list_empty(&cache->leaves)) {
228 node = list_entry(cache->leaves.next,
229 struct backref_node, lower);
230 remove_backref_node(cache, node);
233 cache->last_trans = 0;
235 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
236 BUG_ON(!list_empty(&cache->pending[i]));
237 BUG_ON(!list_empty(&cache->changed));
238 BUG_ON(!list_empty(&cache->detached));
239 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
240 BUG_ON(cache->nr_nodes);
241 BUG_ON(cache->nr_edges);
244 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
246 struct backref_node *node;
248 node = kzalloc(sizeof(*node), GFP_NOFS);
250 INIT_LIST_HEAD(&node->list);
251 INIT_LIST_HEAD(&node->upper);
252 INIT_LIST_HEAD(&node->lower);
253 RB_CLEAR_NODE(&node->rb_node);
259 static void free_backref_node(struct backref_cache *cache,
260 struct backref_node *node)
268 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
270 struct backref_edge *edge;
272 edge = kzalloc(sizeof(*edge), GFP_NOFS);
278 static void free_backref_edge(struct backref_cache *cache,
279 struct backref_edge *edge)
287 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
288 struct rb_node *node)
290 struct rb_node **p = &root->rb_node;
291 struct rb_node *parent = NULL;
292 struct tree_entry *entry;
296 entry = rb_entry(parent, struct tree_entry, rb_node);
298 if (bytenr < entry->bytenr)
300 else if (bytenr > entry->bytenr)
306 rb_link_node(node, parent, p);
307 rb_insert_color(node, root);
311 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
313 struct rb_node *n = root->rb_node;
314 struct tree_entry *entry;
317 entry = rb_entry(n, struct tree_entry, rb_node);
319 if (bytenr < entry->bytenr)
321 else if (bytenr > entry->bytenr)
329 static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
332 struct btrfs_fs_info *fs_info = NULL;
333 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
336 fs_info = bnode->root->fs_info;
337 btrfs_panic(fs_info, errno, "Inconsistency in backref cache "
338 "found at offset %llu\n", (unsigned long long)bytenr);
342 * walk up backref nodes until reach node presents tree root
344 static struct backref_node *walk_up_backref(struct backref_node *node,
345 struct backref_edge *edges[],
348 struct backref_edge *edge;
351 while (!list_empty(&node->upper)) {
352 edge = list_entry(node->upper.next,
353 struct backref_edge, list[LOWER]);
355 node = edge->node[UPPER];
357 BUG_ON(node->detached);
363 * walk down backref nodes to find start of next reference path
365 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
368 struct backref_edge *edge;
369 struct backref_node *lower;
373 edge = edges[idx - 1];
374 lower = edge->node[LOWER];
375 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
379 edge = list_entry(edge->list[LOWER].next,
380 struct backref_edge, list[LOWER]);
381 edges[idx - 1] = edge;
383 return edge->node[UPPER];
389 static void unlock_node_buffer(struct backref_node *node)
392 btrfs_tree_unlock(node->eb);
397 static void drop_node_buffer(struct backref_node *node)
400 unlock_node_buffer(node);
401 free_extent_buffer(node->eb);
406 static void drop_backref_node(struct backref_cache *tree,
407 struct backref_node *node)
409 BUG_ON(!list_empty(&node->upper));
411 drop_node_buffer(node);
412 list_del(&node->list);
413 list_del(&node->lower);
414 if (!RB_EMPTY_NODE(&node->rb_node))
415 rb_erase(&node->rb_node, &tree->rb_root);
416 free_backref_node(tree, node);
420 * remove a backref node from the backref cache
422 static void remove_backref_node(struct backref_cache *cache,
423 struct backref_node *node)
425 struct backref_node *upper;
426 struct backref_edge *edge;
431 BUG_ON(!node->lowest && !node->detached);
432 while (!list_empty(&node->upper)) {
433 edge = list_entry(node->upper.next, struct backref_edge,
435 upper = edge->node[UPPER];
436 list_del(&edge->list[LOWER]);
437 list_del(&edge->list[UPPER]);
438 free_backref_edge(cache, edge);
440 if (RB_EMPTY_NODE(&upper->rb_node)) {
441 BUG_ON(!list_empty(&node->upper));
442 drop_backref_node(cache, node);
448 * add the node to leaf node list if no other
449 * child block cached.
451 if (list_empty(&upper->lower)) {
452 list_add_tail(&upper->lower, &cache->leaves);
457 drop_backref_node(cache, node);
460 static void update_backref_node(struct backref_cache *cache,
461 struct backref_node *node, u64 bytenr)
463 struct rb_node *rb_node;
464 rb_erase(&node->rb_node, &cache->rb_root);
465 node->bytenr = bytenr;
466 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
468 backref_tree_panic(rb_node, -EEXIST, bytenr);
472 * update backref cache after a transaction commit
474 static int update_backref_cache(struct btrfs_trans_handle *trans,
475 struct backref_cache *cache)
477 struct backref_node *node;
480 if (cache->last_trans == 0) {
481 cache->last_trans = trans->transid;
485 if (cache->last_trans == trans->transid)
489 * detached nodes are used to avoid unnecessary backref
490 * lookup. transaction commit changes the extent tree.
491 * so the detached nodes are no longer useful.
493 while (!list_empty(&cache->detached)) {
494 node = list_entry(cache->detached.next,
495 struct backref_node, list);
496 remove_backref_node(cache, node);
499 while (!list_empty(&cache->changed)) {
500 node = list_entry(cache->changed.next,
501 struct backref_node, list);
502 list_del_init(&node->list);
503 BUG_ON(node->pending);
504 update_backref_node(cache, node, node->new_bytenr);
508 * some nodes can be left in the pending list if there were
509 * errors during processing the pending nodes.
511 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
512 list_for_each_entry(node, &cache->pending[level], list) {
513 BUG_ON(!node->pending);
514 if (node->bytenr == node->new_bytenr)
516 update_backref_node(cache, node, node->new_bytenr);
520 cache->last_trans = 0;
525 static int should_ignore_root(struct btrfs_root *root)
527 struct btrfs_root *reloc_root;
532 reloc_root = root->reloc_root;
536 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
537 root->fs_info->running_transaction->transid - 1)
540 * if there is reloc tree and it was created in previous
541 * transaction backref lookup can find the reloc tree,
542 * so backref node for the fs tree root is useless for
548 * find reloc tree by address of tree root
550 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
553 struct rb_node *rb_node;
554 struct mapping_node *node;
555 struct btrfs_root *root = NULL;
557 spin_lock(&rc->reloc_root_tree.lock);
558 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
560 node = rb_entry(rb_node, struct mapping_node, rb_node);
561 root = (struct btrfs_root *)node->data;
563 spin_unlock(&rc->reloc_root_tree.lock);
567 static int is_cowonly_root(u64 root_objectid)
569 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
570 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
571 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
572 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
573 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
574 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
579 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
582 struct btrfs_key key;
584 key.objectid = root_objectid;
585 key.type = BTRFS_ROOT_ITEM_KEY;
586 if (is_cowonly_root(root_objectid))
589 key.offset = (u64)-1;
591 return btrfs_read_fs_root_no_name(fs_info, &key);
594 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
595 static noinline_for_stack
596 struct btrfs_root *find_tree_root(struct reloc_control *rc,
597 struct extent_buffer *leaf,
598 struct btrfs_extent_ref_v0 *ref0)
600 struct btrfs_root *root;
601 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
602 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
604 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
606 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
607 BUG_ON(IS_ERR(root));
609 if (root->ref_cows &&
610 generation != btrfs_root_generation(&root->root_item))
617 static noinline_for_stack
618 int find_inline_backref(struct extent_buffer *leaf, int slot,
619 unsigned long *ptr, unsigned long *end)
621 struct btrfs_key key;
622 struct btrfs_extent_item *ei;
623 struct btrfs_tree_block_info *bi;
626 btrfs_item_key_to_cpu(leaf, &key, slot);
628 item_size = btrfs_item_size_nr(leaf, slot);
629 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
630 if (item_size < sizeof(*ei)) {
631 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
635 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
636 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
637 BTRFS_EXTENT_FLAG_TREE_BLOCK));
639 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
640 item_size <= sizeof(*ei) + sizeof(*bi)) {
641 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
645 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
646 bi = (struct btrfs_tree_block_info *)(ei + 1);
647 *ptr = (unsigned long)(bi + 1);
649 *ptr = (unsigned long)(ei + 1);
651 *end = (unsigned long)ei + item_size;
656 * build backref tree for a given tree block. root of the backref tree
657 * corresponds the tree block, leaves of the backref tree correspond
658 * roots of b-trees that reference the tree block.
660 * the basic idea of this function is check backrefs of a given block
661 * to find upper level blocks that refernece the block, and then check
662 * bakcrefs of these upper level blocks recursively. the recursion stop
663 * when tree root is reached or backrefs for the block is cached.
665 * NOTE: if we find backrefs for a block are cached, we know backrefs
666 * for all upper level blocks that directly/indirectly reference the
667 * block are also cached.
669 static noinline_for_stack
670 struct backref_node *build_backref_tree(struct reloc_control *rc,
671 struct btrfs_key *node_key,
672 int level, u64 bytenr)
674 struct backref_cache *cache = &rc->backref_cache;
675 struct btrfs_path *path1;
676 struct btrfs_path *path2;
677 struct extent_buffer *eb;
678 struct btrfs_root *root;
679 struct backref_node *cur;
680 struct backref_node *upper;
681 struct backref_node *lower;
682 struct backref_node *node = NULL;
683 struct backref_node *exist = NULL;
684 struct backref_edge *edge;
685 struct rb_node *rb_node;
686 struct btrfs_key key;
694 bool need_check = true;
696 path1 = btrfs_alloc_path();
697 path2 = btrfs_alloc_path();
698 if (!path1 || !path2) {
705 node = alloc_backref_node(cache);
711 node->bytenr = bytenr;
718 key.objectid = cur->bytenr;
719 key.type = BTRFS_METADATA_ITEM_KEY;
720 key.offset = (u64)-1;
722 path1->search_commit_root = 1;
723 path1->skip_locking = 1;
724 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
730 BUG_ON(!ret || !path1->slots[0]);
734 WARN_ON(cur->checked);
735 if (!list_empty(&cur->upper)) {
737 * the backref was added previously when processing
738 * backref of type BTRFS_TREE_BLOCK_REF_KEY
740 BUG_ON(!list_is_singular(&cur->upper));
741 edge = list_entry(cur->upper.next, struct backref_edge,
743 BUG_ON(!list_empty(&edge->list[UPPER]));
744 exist = edge->node[UPPER];
746 * add the upper level block to pending list if we need
750 list_add_tail(&edge->list[UPPER], &list);
757 eb = path1->nodes[0];
760 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
761 ret = btrfs_next_leaf(rc->extent_root, path1);
768 eb = path1->nodes[0];
771 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
772 if (key.objectid != cur->bytenr) {
777 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
778 key.type == BTRFS_METADATA_ITEM_KEY) {
779 ret = find_inline_backref(eb, path1->slots[0],
787 /* update key for inline back ref */
788 struct btrfs_extent_inline_ref *iref;
789 iref = (struct btrfs_extent_inline_ref *)ptr;
790 key.type = btrfs_extent_inline_ref_type(eb, iref);
791 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
792 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
793 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
797 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
798 exist->owner == key.offset) ||
799 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
800 exist->bytenr == key.offset))) {
805 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
806 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
807 key.type == BTRFS_EXTENT_REF_V0_KEY) {
808 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
809 struct btrfs_extent_ref_v0 *ref0;
810 ref0 = btrfs_item_ptr(eb, path1->slots[0],
811 struct btrfs_extent_ref_v0);
812 if (key.objectid == key.offset) {
813 root = find_tree_root(rc, eb, ref0);
814 if (root && !should_ignore_root(root))
817 list_add(&cur->list, &useless);
820 if (is_cowonly_root(btrfs_ref_root_v0(eb,
825 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
826 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
828 if (key.objectid == key.offset) {
830 * only root blocks of reloc trees use
831 * backref of this type.
833 root = find_reloc_root(rc, cur->bytenr);
839 edge = alloc_backref_edge(cache);
844 rb_node = tree_search(&cache->rb_root, key.offset);
846 upper = alloc_backref_node(cache);
848 free_backref_edge(cache, edge);
852 upper->bytenr = key.offset;
853 upper->level = cur->level + 1;
855 * backrefs for the upper level block isn't
856 * cached, add the block to pending list
858 list_add_tail(&edge->list[UPPER], &list);
860 upper = rb_entry(rb_node, struct backref_node,
862 BUG_ON(!upper->checked);
863 INIT_LIST_HEAD(&edge->list[UPPER]);
865 list_add_tail(&edge->list[LOWER], &cur->upper);
866 edge->node[LOWER] = cur;
867 edge->node[UPPER] = upper;
870 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
874 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
875 root = read_fs_root(rc->extent_root->fs_info, key.offset);
884 if (btrfs_root_level(&root->root_item) == cur->level) {
886 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
888 if (should_ignore_root(root))
889 list_add(&cur->list, &useless);
895 level = cur->level + 1;
898 * searching the tree to find upper level blocks
899 * reference the block.
901 path2->search_commit_root = 1;
902 path2->skip_locking = 1;
903 path2->lowest_level = level;
904 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
905 path2->lowest_level = 0;
910 if (ret > 0 && path2->slots[level] > 0)
911 path2->slots[level]--;
913 eb = path2->nodes[level];
914 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
919 for (; level < BTRFS_MAX_LEVEL; level++) {
920 if (!path2->nodes[level]) {
921 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
923 if (should_ignore_root(root))
924 list_add(&lower->list, &useless);
930 edge = alloc_backref_edge(cache);
936 eb = path2->nodes[level];
937 rb_node = tree_search(&cache->rb_root, eb->start);
939 upper = alloc_backref_node(cache);
941 free_backref_edge(cache, edge);
945 upper->bytenr = eb->start;
946 upper->owner = btrfs_header_owner(eb);
947 upper->level = lower->level + 1;
952 * if we know the block isn't shared
953 * we can void checking its backrefs.
955 if (btrfs_block_can_be_shared(root, eb))
961 * add the block to pending list if we
962 * need check its backrefs, we only do this once
963 * while walking up a tree as we will catch
964 * anything else later on.
966 if (!upper->checked && need_check) {
968 list_add_tail(&edge->list[UPPER],
973 INIT_LIST_HEAD(&edge->list[UPPER]);
976 upper = rb_entry(rb_node, struct backref_node,
978 BUG_ON(!upper->checked);
979 INIT_LIST_HEAD(&edge->list[UPPER]);
981 upper->owner = btrfs_header_owner(eb);
983 list_add_tail(&edge->list[LOWER], &lower->upper);
984 edge->node[LOWER] = lower;
985 edge->node[UPPER] = upper;
992 btrfs_release_path(path2);
995 ptr += btrfs_extent_inline_ref_size(key.type);
1005 btrfs_release_path(path1);
1010 /* the pending list isn't empty, take the first block to process */
1011 if (!list_empty(&list)) {
1012 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1013 list_del_init(&edge->list[UPPER]);
1014 cur = edge->node[UPPER];
1019 * everything goes well, connect backref nodes and insert backref nodes
1022 BUG_ON(!node->checked);
1023 cowonly = node->cowonly;
1025 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1028 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1029 list_add_tail(&node->lower, &cache->leaves);
1032 list_for_each_entry(edge, &node->upper, list[LOWER])
1033 list_add_tail(&edge->list[UPPER], &list);
1035 while (!list_empty(&list)) {
1036 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1037 list_del_init(&edge->list[UPPER]);
1038 upper = edge->node[UPPER];
1039 if (upper->detached) {
1040 list_del(&edge->list[LOWER]);
1041 lower = edge->node[LOWER];
1042 free_backref_edge(cache, edge);
1043 if (list_empty(&lower->upper))
1044 list_add(&lower->list, &useless);
1048 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1049 if (upper->lowest) {
1050 list_del_init(&upper->lower);
1054 list_add_tail(&edge->list[UPPER], &upper->lower);
1058 BUG_ON(!upper->checked);
1059 BUG_ON(cowonly != upper->cowonly);
1061 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1064 backref_tree_panic(rb_node, -EEXIST,
1068 list_add_tail(&edge->list[UPPER], &upper->lower);
1070 list_for_each_entry(edge, &upper->upper, list[LOWER])
1071 list_add_tail(&edge->list[UPPER], &list);
1074 * process useless backref nodes. backref nodes for tree leaves
1075 * are deleted from the cache. backref nodes for upper level
1076 * tree blocks are left in the cache to avoid unnecessary backref
1079 while (!list_empty(&useless)) {
1080 upper = list_entry(useless.next, struct backref_node, list);
1081 list_del_init(&upper->list);
1082 BUG_ON(!list_empty(&upper->upper));
1085 if (upper->lowest) {
1086 list_del_init(&upper->lower);
1089 while (!list_empty(&upper->lower)) {
1090 edge = list_entry(upper->lower.next,
1091 struct backref_edge, list[UPPER]);
1092 list_del(&edge->list[UPPER]);
1093 list_del(&edge->list[LOWER]);
1094 lower = edge->node[LOWER];
1095 free_backref_edge(cache, edge);
1097 if (list_empty(&lower->upper))
1098 list_add(&lower->list, &useless);
1100 __mark_block_processed(rc, upper);
1101 if (upper->level > 0) {
1102 list_add(&upper->list, &cache->detached);
1103 upper->detached = 1;
1105 rb_erase(&upper->rb_node, &cache->rb_root);
1106 free_backref_node(cache, upper);
1110 btrfs_free_path(path1);
1111 btrfs_free_path(path2);
1113 while (!list_empty(&useless)) {
1114 lower = list_entry(useless.next,
1115 struct backref_node, upper);
1116 list_del_init(&lower->upper);
1119 INIT_LIST_HEAD(&list);
1121 if (RB_EMPTY_NODE(&upper->rb_node)) {
1122 list_splice_tail(&upper->upper, &list);
1123 free_backref_node(cache, upper);
1126 if (list_empty(&list))
1129 edge = list_entry(list.next, struct backref_edge,
1131 list_del(&edge->list[LOWER]);
1132 upper = edge->node[UPPER];
1133 free_backref_edge(cache, edge);
1135 return ERR_PTR(err);
1137 BUG_ON(node && node->detached);
1142 * helper to add backref node for the newly created snapshot.
1143 * the backref node is created by cloning backref node that
1144 * corresponds to root of source tree
1146 static int clone_backref_node(struct btrfs_trans_handle *trans,
1147 struct reloc_control *rc,
1148 struct btrfs_root *src,
1149 struct btrfs_root *dest)
1151 struct btrfs_root *reloc_root = src->reloc_root;
1152 struct backref_cache *cache = &rc->backref_cache;
1153 struct backref_node *node = NULL;
1154 struct backref_node *new_node;
1155 struct backref_edge *edge;
1156 struct backref_edge *new_edge;
1157 struct rb_node *rb_node;
1159 if (cache->last_trans > 0)
1160 update_backref_cache(trans, cache);
1162 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1164 node = rb_entry(rb_node, struct backref_node, rb_node);
1168 BUG_ON(node->new_bytenr != reloc_root->node->start);
1172 rb_node = tree_search(&cache->rb_root,
1173 reloc_root->commit_root->start);
1175 node = rb_entry(rb_node, struct backref_node,
1177 BUG_ON(node->detached);
1184 new_node = alloc_backref_node(cache);
1188 new_node->bytenr = dest->node->start;
1189 new_node->level = node->level;
1190 new_node->lowest = node->lowest;
1191 new_node->checked = 1;
1192 new_node->root = dest;
1194 if (!node->lowest) {
1195 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1196 new_edge = alloc_backref_edge(cache);
1200 new_edge->node[UPPER] = new_node;
1201 new_edge->node[LOWER] = edge->node[LOWER];
1202 list_add_tail(&new_edge->list[UPPER],
1206 list_add_tail(&new_node->lower, &cache->leaves);
1209 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1210 &new_node->rb_node);
1212 backref_tree_panic(rb_node, -EEXIST, new_node->bytenr);
1214 if (!new_node->lowest) {
1215 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1216 list_add_tail(&new_edge->list[LOWER],
1217 &new_edge->node[LOWER]->upper);
1222 while (!list_empty(&new_node->lower)) {
1223 new_edge = list_entry(new_node->lower.next,
1224 struct backref_edge, list[UPPER]);
1225 list_del(&new_edge->list[UPPER]);
1226 free_backref_edge(cache, new_edge);
1228 free_backref_node(cache, new_node);
1233 * helper to add 'address of tree root -> reloc tree' mapping
1235 static int __must_check __add_reloc_root(struct btrfs_root *root)
1237 struct rb_node *rb_node;
1238 struct mapping_node *node;
1239 struct reloc_control *rc = root->fs_info->reloc_ctl;
1241 node = kmalloc(sizeof(*node), GFP_NOFS);
1245 node->bytenr = root->node->start;
1248 spin_lock(&rc->reloc_root_tree.lock);
1249 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1250 node->bytenr, &node->rb_node);
1251 spin_unlock(&rc->reloc_root_tree.lock);
1253 btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found "
1254 "for start=%llu while inserting into relocation "
1255 "tree\n", node->bytenr);
1260 list_add_tail(&root->root_list, &rc->reloc_roots);
1265 * helper to update/delete the 'address of tree root -> reloc tree'
1268 static int __update_reloc_root(struct btrfs_root *root, int del)
1270 struct rb_node *rb_node;
1271 struct mapping_node *node = NULL;
1272 struct reloc_control *rc = root->fs_info->reloc_ctl;
1274 spin_lock(&rc->reloc_root_tree.lock);
1275 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1276 root->commit_root->start);
1278 node = rb_entry(rb_node, struct mapping_node, rb_node);
1279 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1281 spin_unlock(&rc->reloc_root_tree.lock);
1285 BUG_ON((struct btrfs_root *)node->data != root);
1288 spin_lock(&rc->reloc_root_tree.lock);
1289 node->bytenr = root->node->start;
1290 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1291 node->bytenr, &node->rb_node);
1292 spin_unlock(&rc->reloc_root_tree.lock);
1294 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1296 spin_lock(&root->fs_info->trans_lock);
1297 list_del_init(&root->root_list);
1298 spin_unlock(&root->fs_info->trans_lock);
1304 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1305 struct btrfs_root *root, u64 objectid)
1307 struct btrfs_root *reloc_root;
1308 struct extent_buffer *eb;
1309 struct btrfs_root_item *root_item;
1310 struct btrfs_key root_key;
1313 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1316 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1317 root_key.type = BTRFS_ROOT_ITEM_KEY;
1318 root_key.offset = objectid;
1320 if (root->root_key.objectid == objectid) {
1321 /* called by btrfs_init_reloc_root */
1322 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1323 BTRFS_TREE_RELOC_OBJECTID);
1326 btrfs_set_root_last_snapshot(&root->root_item,
1327 trans->transid - 1);
1330 * called by btrfs_reloc_post_snapshot_hook.
1331 * the source tree is a reloc tree, all tree blocks
1332 * modified after it was created have RELOC flag
1333 * set in their headers. so it's OK to not update
1334 * the 'last_snapshot'.
1336 ret = btrfs_copy_root(trans, root, root->node, &eb,
1337 BTRFS_TREE_RELOC_OBJECTID);
1341 memcpy(root_item, &root->root_item, sizeof(*root_item));
1342 btrfs_set_root_bytenr(root_item, eb->start);
1343 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1344 btrfs_set_root_generation(root_item, trans->transid);
1346 if (root->root_key.objectid == objectid) {
1347 btrfs_set_root_refs(root_item, 0);
1348 memset(&root_item->drop_progress, 0,
1349 sizeof(struct btrfs_disk_key));
1350 root_item->drop_level = 0;
1353 btrfs_tree_unlock(eb);
1354 free_extent_buffer(eb);
1356 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1357 &root_key, root_item);
1361 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
1363 BUG_ON(IS_ERR(reloc_root));
1364 reloc_root->last_trans = trans->transid;
1369 * create reloc tree for a given fs tree. reloc tree is just a
1370 * snapshot of the fs tree with special root objectid.
1372 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1373 struct btrfs_root *root)
1375 struct btrfs_root *reloc_root;
1376 struct reloc_control *rc = root->fs_info->reloc_ctl;
1380 if (root->reloc_root) {
1381 reloc_root = root->reloc_root;
1382 reloc_root->last_trans = trans->transid;
1386 if (!rc || !rc->create_reloc_tree ||
1387 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1390 if (!trans->block_rsv) {
1391 trans->block_rsv = rc->block_rsv;
1394 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1396 trans->block_rsv = NULL;
1398 ret = __add_reloc_root(reloc_root);
1400 root->reloc_root = reloc_root;
1405 * update root item of reloc tree
1407 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1408 struct btrfs_root *root)
1410 struct btrfs_root *reloc_root;
1411 struct btrfs_root_item *root_item;
1415 if (!root->reloc_root)
1418 reloc_root = root->reloc_root;
1419 root_item = &reloc_root->root_item;
1421 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1422 btrfs_root_refs(root_item) == 0) {
1423 root->reloc_root = NULL;
1427 __update_reloc_root(reloc_root, del);
1429 if (reloc_root->commit_root != reloc_root->node) {
1430 btrfs_set_root_node(root_item, reloc_root->node);
1431 free_extent_buffer(reloc_root->commit_root);
1432 reloc_root->commit_root = btrfs_root_node(reloc_root);
1435 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1436 &reloc_root->root_key, root_item);
1444 * helper to find first cached inode with inode number >= objectid
1447 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1449 struct rb_node *node;
1450 struct rb_node *prev;
1451 struct btrfs_inode *entry;
1452 struct inode *inode;
1454 spin_lock(&root->inode_lock);
1456 node = root->inode_tree.rb_node;
1460 entry = rb_entry(node, struct btrfs_inode, rb_node);
1462 if (objectid < btrfs_ino(&entry->vfs_inode))
1463 node = node->rb_left;
1464 else if (objectid > btrfs_ino(&entry->vfs_inode))
1465 node = node->rb_right;
1471 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1472 if (objectid <= btrfs_ino(&entry->vfs_inode)) {
1476 prev = rb_next(prev);
1480 entry = rb_entry(node, struct btrfs_inode, rb_node);
1481 inode = igrab(&entry->vfs_inode);
1483 spin_unlock(&root->inode_lock);
1487 objectid = btrfs_ino(&entry->vfs_inode) + 1;
1488 if (cond_resched_lock(&root->inode_lock))
1491 node = rb_next(node);
1493 spin_unlock(&root->inode_lock);
1497 static int in_block_group(u64 bytenr,
1498 struct btrfs_block_group_cache *block_group)
1500 if (bytenr >= block_group->key.objectid &&
1501 bytenr < block_group->key.objectid + block_group->key.offset)
1507 * get new location of data
1509 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1510 u64 bytenr, u64 num_bytes)
1512 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1513 struct btrfs_path *path;
1514 struct btrfs_file_extent_item *fi;
1515 struct extent_buffer *leaf;
1518 path = btrfs_alloc_path();
1522 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1523 ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode),
1532 leaf = path->nodes[0];
1533 fi = btrfs_item_ptr(leaf, path->slots[0],
1534 struct btrfs_file_extent_item);
1536 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1537 btrfs_file_extent_compression(leaf, fi) ||
1538 btrfs_file_extent_encryption(leaf, fi) ||
1539 btrfs_file_extent_other_encoding(leaf, fi));
1541 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1546 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1549 btrfs_free_path(path);
1554 * update file extent items in the tree leaf to point to
1555 * the new locations.
1557 static noinline_for_stack
1558 int replace_file_extents(struct btrfs_trans_handle *trans,
1559 struct reloc_control *rc,
1560 struct btrfs_root *root,
1561 struct extent_buffer *leaf)
1563 struct btrfs_key key;
1564 struct btrfs_file_extent_item *fi;
1565 struct inode *inode = NULL;
1577 if (rc->stage != UPDATE_DATA_PTRS)
1580 /* reloc trees always use full backref */
1581 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1582 parent = leaf->start;
1586 nritems = btrfs_header_nritems(leaf);
1587 for (i = 0; i < nritems; i++) {
1589 btrfs_item_key_to_cpu(leaf, &key, i);
1590 if (key.type != BTRFS_EXTENT_DATA_KEY)
1592 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1593 if (btrfs_file_extent_type(leaf, fi) ==
1594 BTRFS_FILE_EXTENT_INLINE)
1596 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1597 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1600 if (!in_block_group(bytenr, rc->block_group))
1604 * if we are modifying block in fs tree, wait for readpage
1605 * to complete and drop the extent cache
1607 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1609 inode = find_next_inode(root, key.objectid);
1611 } else if (inode && btrfs_ino(inode) < key.objectid) {
1612 btrfs_add_delayed_iput(inode);
1613 inode = find_next_inode(root, key.objectid);
1615 if (inode && btrfs_ino(inode) == key.objectid) {
1617 btrfs_file_extent_num_bytes(leaf, fi);
1618 WARN_ON(!IS_ALIGNED(key.offset,
1620 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1622 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1627 btrfs_drop_extent_cache(inode, key.offset, end,
1629 unlock_extent(&BTRFS_I(inode)->io_tree,
1634 ret = get_new_location(rc->data_inode, &new_bytenr,
1642 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1645 key.offset -= btrfs_file_extent_offset(leaf, fi);
1646 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1648 btrfs_header_owner(leaf),
1649 key.objectid, key.offset, 1);
1652 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1653 parent, btrfs_header_owner(leaf),
1654 key.objectid, key.offset, 1);
1658 btrfs_mark_buffer_dirty(leaf);
1660 btrfs_add_delayed_iput(inode);
1664 static noinline_for_stack
1665 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1666 struct btrfs_path *path, int level)
1668 struct btrfs_disk_key key1;
1669 struct btrfs_disk_key key2;
1670 btrfs_node_key(eb, &key1, slot);
1671 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1672 return memcmp(&key1, &key2, sizeof(key1));
1676 * try to replace tree blocks in fs tree with the new blocks
1677 * in reloc tree. tree blocks haven't been modified since the
1678 * reloc tree was create can be replaced.
1680 * if a block was replaced, level of the block + 1 is returned.
1681 * if no block got replaced, 0 is returned. if there are other
1682 * errors, a negative error number is returned.
1684 static noinline_for_stack
1685 int replace_path(struct btrfs_trans_handle *trans,
1686 struct btrfs_root *dest, struct btrfs_root *src,
1687 struct btrfs_path *path, struct btrfs_key *next_key,
1688 int lowest_level, int max_level)
1690 struct extent_buffer *eb;
1691 struct extent_buffer *parent;
1692 struct btrfs_key key;
1704 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1705 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1707 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1709 slot = path->slots[lowest_level];
1710 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1712 eb = btrfs_lock_root_node(dest);
1713 btrfs_set_lock_blocking(eb);
1714 level = btrfs_header_level(eb);
1716 if (level < lowest_level) {
1717 btrfs_tree_unlock(eb);
1718 free_extent_buffer(eb);
1723 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1726 btrfs_set_lock_blocking(eb);
1729 next_key->objectid = (u64)-1;
1730 next_key->type = (u8)-1;
1731 next_key->offset = (u64)-1;
1736 level = btrfs_header_level(parent);
1737 BUG_ON(level < lowest_level);
1739 ret = btrfs_bin_search(parent, &key, level, &slot);
1740 if (ret && slot > 0)
1743 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1744 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1746 old_bytenr = btrfs_node_blockptr(parent, slot);
1747 blocksize = btrfs_level_size(dest, level - 1);
1748 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1750 if (level <= max_level) {
1751 eb = path->nodes[level];
1752 new_bytenr = btrfs_node_blockptr(eb,
1753 path->slots[level]);
1754 new_ptr_gen = btrfs_node_ptr_generation(eb,
1755 path->slots[level]);
1761 if (new_bytenr > 0 && new_bytenr == old_bytenr) {
1767 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1768 memcmp_node_keys(parent, slot, path, level)) {
1769 if (level <= lowest_level) {
1774 eb = read_tree_block(dest, old_bytenr, blocksize,
1776 if (!eb || !extent_buffer_uptodate(eb)) {
1777 ret = (!eb) ? -ENOMEM : -EIO;
1778 free_extent_buffer(eb);
1781 btrfs_tree_lock(eb);
1783 ret = btrfs_cow_block(trans, dest, eb, parent,
1787 btrfs_set_lock_blocking(eb);
1789 btrfs_tree_unlock(parent);
1790 free_extent_buffer(parent);
1797 btrfs_tree_unlock(parent);
1798 free_extent_buffer(parent);
1803 btrfs_node_key_to_cpu(path->nodes[level], &key,
1804 path->slots[level]);
1805 btrfs_release_path(path);
1807 path->lowest_level = level;
1808 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1809 path->lowest_level = 0;
1813 * swap blocks in fs tree and reloc tree.
1815 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1816 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1817 btrfs_mark_buffer_dirty(parent);
1819 btrfs_set_node_blockptr(path->nodes[level],
1820 path->slots[level], old_bytenr);
1821 btrfs_set_node_ptr_generation(path->nodes[level],
1822 path->slots[level], old_ptr_gen);
1823 btrfs_mark_buffer_dirty(path->nodes[level]);
1825 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1826 path->nodes[level]->start,
1827 src->root_key.objectid, level - 1, 0,
1830 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1831 0, dest->root_key.objectid, level - 1,
1835 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1836 path->nodes[level]->start,
1837 src->root_key.objectid, level - 1, 0,
1841 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1842 0, dest->root_key.objectid, level - 1,
1846 btrfs_unlock_up_safe(path, 0);
1851 btrfs_tree_unlock(parent);
1852 free_extent_buffer(parent);
1857 * helper to find next relocated block in reloc tree
1859 static noinline_for_stack
1860 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1863 struct extent_buffer *eb;
1868 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1870 for (i = 0; i < *level; i++) {
1871 free_extent_buffer(path->nodes[i]);
1872 path->nodes[i] = NULL;
1875 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1876 eb = path->nodes[i];
1877 nritems = btrfs_header_nritems(eb);
1878 while (path->slots[i] + 1 < nritems) {
1880 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1887 free_extent_buffer(path->nodes[i]);
1888 path->nodes[i] = NULL;
1894 * walk down reloc tree to find relocated block of lowest level
1896 static noinline_for_stack
1897 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1900 struct extent_buffer *eb = NULL;
1908 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1910 for (i = *level; i > 0; i--) {
1911 eb = path->nodes[i];
1912 nritems = btrfs_header_nritems(eb);
1913 while (path->slots[i] < nritems) {
1914 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1915 if (ptr_gen > last_snapshot)
1919 if (path->slots[i] >= nritems) {
1930 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
1931 blocksize = btrfs_level_size(root, i - 1);
1932 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
1933 if (!eb || !extent_buffer_uptodate(eb)) {
1934 free_extent_buffer(eb);
1937 BUG_ON(btrfs_header_level(eb) != i - 1);
1938 path->nodes[i - 1] = eb;
1939 path->slots[i - 1] = 0;
1945 * invalidate extent cache for file extents whose key in range of
1946 * [min_key, max_key)
1948 static int invalidate_extent_cache(struct btrfs_root *root,
1949 struct btrfs_key *min_key,
1950 struct btrfs_key *max_key)
1952 struct inode *inode = NULL;
1957 objectid = min_key->objectid;
1962 if (objectid > max_key->objectid)
1965 inode = find_next_inode(root, objectid);
1968 ino = btrfs_ino(inode);
1970 if (ino > max_key->objectid) {
1976 if (!S_ISREG(inode->i_mode))
1979 if (unlikely(min_key->objectid == ino)) {
1980 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
1982 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
1985 start = min_key->offset;
1986 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
1992 if (unlikely(max_key->objectid == ino)) {
1993 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
1995 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
1998 if (max_key->offset == 0)
2000 end = max_key->offset;
2001 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
2008 /* the lock_extent waits for readpage to complete */
2009 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2010 btrfs_drop_extent_cache(inode, start, end, 1);
2011 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2016 static int find_next_key(struct btrfs_path *path, int level,
2017 struct btrfs_key *key)
2020 while (level < BTRFS_MAX_LEVEL) {
2021 if (!path->nodes[level])
2023 if (path->slots[level] + 1 <
2024 btrfs_header_nritems(path->nodes[level])) {
2025 btrfs_node_key_to_cpu(path->nodes[level], key,
2026 path->slots[level] + 1);
2035 * merge the relocated tree blocks in reloc tree with corresponding
2038 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2039 struct btrfs_root *root)
2041 LIST_HEAD(inode_list);
2042 struct btrfs_key key;
2043 struct btrfs_key next_key;
2044 struct btrfs_trans_handle *trans;
2045 struct btrfs_root *reloc_root;
2046 struct btrfs_root_item *root_item;
2047 struct btrfs_path *path;
2048 struct extent_buffer *leaf;
2056 path = btrfs_alloc_path();
2061 reloc_root = root->reloc_root;
2062 root_item = &reloc_root->root_item;
2064 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2065 level = btrfs_root_level(root_item);
2066 extent_buffer_get(reloc_root->node);
2067 path->nodes[level] = reloc_root->node;
2068 path->slots[level] = 0;
2070 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2072 level = root_item->drop_level;
2074 path->lowest_level = level;
2075 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2076 path->lowest_level = 0;
2078 btrfs_free_path(path);
2082 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2083 path->slots[level]);
2084 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2086 btrfs_unlock_up_safe(path, 0);
2089 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2090 memset(&next_key, 0, sizeof(next_key));
2093 trans = btrfs_start_transaction(root, 0);
2094 BUG_ON(IS_ERR(trans));
2095 trans->block_rsv = rc->block_rsv;
2097 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2098 BTRFS_RESERVE_FLUSH_ALL);
2100 BUG_ON(ret != -EAGAIN);
2101 ret = btrfs_commit_transaction(trans, root);
2109 ret = walk_down_reloc_tree(reloc_root, path, &level);
2117 if (!find_next_key(path, level, &key) &&
2118 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2121 ret = replace_path(trans, root, reloc_root, path,
2122 &next_key, level, max_level);
2131 btrfs_node_key_to_cpu(path->nodes[level], &key,
2132 path->slots[level]);
2136 ret = walk_up_reloc_tree(reloc_root, path, &level);
2142 * save the merging progress in the drop_progress.
2143 * this is OK since root refs == 1 in this case.
2145 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2146 path->slots[level]);
2147 root_item->drop_level = level;
2149 btrfs_end_transaction_throttle(trans, root);
2151 btrfs_btree_balance_dirty(root);
2153 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2154 invalidate_extent_cache(root, &key, &next_key);
2158 * handle the case only one block in the fs tree need to be
2159 * relocated and the block is tree root.
2161 leaf = btrfs_lock_root_node(root);
2162 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2163 btrfs_tree_unlock(leaf);
2164 free_extent_buffer(leaf);
2168 btrfs_free_path(path);
2171 memset(&root_item->drop_progress, 0,
2172 sizeof(root_item->drop_progress));
2173 root_item->drop_level = 0;
2174 btrfs_set_root_refs(root_item, 0);
2175 btrfs_update_reloc_root(trans, root);
2178 btrfs_end_transaction_throttle(trans, root);
2180 btrfs_btree_balance_dirty(root);
2182 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2183 invalidate_extent_cache(root, &key, &next_key);
2188 static noinline_for_stack
2189 int prepare_to_merge(struct reloc_control *rc, int err)
2191 struct btrfs_root *root = rc->extent_root;
2192 struct btrfs_root *reloc_root;
2193 struct btrfs_trans_handle *trans;
2194 LIST_HEAD(reloc_roots);
2198 mutex_lock(&root->fs_info->reloc_mutex);
2199 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2200 rc->merging_rsv_size += rc->nodes_relocated * 2;
2201 mutex_unlock(&root->fs_info->reloc_mutex);
2205 num_bytes = rc->merging_rsv_size;
2206 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2207 BTRFS_RESERVE_FLUSH_ALL);
2212 trans = btrfs_join_transaction(rc->extent_root);
2213 if (IS_ERR(trans)) {
2215 btrfs_block_rsv_release(rc->extent_root,
2216 rc->block_rsv, num_bytes);
2217 return PTR_ERR(trans);
2221 if (num_bytes != rc->merging_rsv_size) {
2222 btrfs_end_transaction(trans, rc->extent_root);
2223 btrfs_block_rsv_release(rc->extent_root,
2224 rc->block_rsv, num_bytes);
2229 rc->merge_reloc_tree = 1;
2231 while (!list_empty(&rc->reloc_roots)) {
2232 reloc_root = list_entry(rc->reloc_roots.next,
2233 struct btrfs_root, root_list);
2234 list_del_init(&reloc_root->root_list);
2236 root = read_fs_root(reloc_root->fs_info,
2237 reloc_root->root_key.offset);
2238 BUG_ON(IS_ERR(root));
2239 BUG_ON(root->reloc_root != reloc_root);
2242 * set reference count to 1, so btrfs_recover_relocation
2243 * knows it should resumes merging
2246 btrfs_set_root_refs(&reloc_root->root_item, 1);
2247 btrfs_update_reloc_root(trans, root);
2249 list_add(&reloc_root->root_list, &reloc_roots);
2252 list_splice(&reloc_roots, &rc->reloc_roots);
2255 btrfs_commit_transaction(trans, rc->extent_root);
2257 btrfs_end_transaction(trans, rc->extent_root);
2261 static noinline_for_stack
2262 void free_reloc_roots(struct list_head *list)
2264 struct btrfs_root *reloc_root;
2266 while (!list_empty(list)) {
2267 reloc_root = list_entry(list->next, struct btrfs_root,
2269 __update_reloc_root(reloc_root, 1);
2270 free_extent_buffer(reloc_root->node);
2271 free_extent_buffer(reloc_root->commit_root);
2276 static noinline_for_stack
2277 int merge_reloc_roots(struct reloc_control *rc)
2279 struct btrfs_root *root;
2280 struct btrfs_root *reloc_root;
2281 LIST_HEAD(reloc_roots);
2285 root = rc->extent_root;
2288 * this serializes us with btrfs_record_root_in_transaction,
2289 * we have to make sure nobody is in the middle of
2290 * adding their roots to the list while we are
2293 mutex_lock(&root->fs_info->reloc_mutex);
2294 list_splice_init(&rc->reloc_roots, &reloc_roots);
2295 mutex_unlock(&root->fs_info->reloc_mutex);
2297 while (!list_empty(&reloc_roots)) {
2299 reloc_root = list_entry(reloc_roots.next,
2300 struct btrfs_root, root_list);
2302 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2303 root = read_fs_root(reloc_root->fs_info,
2304 reloc_root->root_key.offset);
2305 BUG_ON(IS_ERR(root));
2306 BUG_ON(root->reloc_root != reloc_root);
2308 ret = merge_reloc_root(rc, root);
2312 list_del_init(&reloc_root->root_list);
2314 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2316 if (list_empty(&reloc_root->root_list))
2317 list_add_tail(&reloc_root->root_list,
2329 btrfs_std_error(root->fs_info, ret);
2330 if (!list_empty(&reloc_roots))
2331 free_reloc_roots(&reloc_roots);
2334 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2338 static void free_block_list(struct rb_root *blocks)
2340 struct tree_block *block;
2341 struct rb_node *rb_node;
2342 while ((rb_node = rb_first(blocks))) {
2343 block = rb_entry(rb_node, struct tree_block, rb_node);
2344 rb_erase(rb_node, blocks);
2349 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2350 struct btrfs_root *reloc_root)
2352 struct btrfs_root *root;
2354 if (reloc_root->last_trans == trans->transid)
2357 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2358 BUG_ON(IS_ERR(root));
2359 BUG_ON(root->reloc_root != reloc_root);
2361 return btrfs_record_root_in_trans(trans, root);
2364 static noinline_for_stack
2365 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2366 struct reloc_control *rc,
2367 struct backref_node *node,
2368 struct backref_edge *edges[], int *nr)
2370 struct backref_node *next;
2371 struct btrfs_root *root;
2377 next = walk_up_backref(next, edges, &index);
2380 BUG_ON(!root->ref_cows);
2382 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2383 record_reloc_root_in_trans(trans, root);
2387 btrfs_record_root_in_trans(trans, root);
2388 root = root->reloc_root;
2390 if (next->new_bytenr != root->node->start) {
2391 BUG_ON(next->new_bytenr);
2392 BUG_ON(!list_empty(&next->list));
2393 next->new_bytenr = root->node->start;
2395 list_add_tail(&next->list,
2396 &rc->backref_cache.changed);
2397 __mark_block_processed(rc, next);
2403 next = walk_down_backref(edges, &index);
2404 if (!next || next->level <= node->level)
2412 /* setup backref node path for btrfs_reloc_cow_block */
2414 rc->backref_cache.path[next->level] = next;
2417 next = edges[index]->node[UPPER];
2423 * select a tree root for relocation. return NULL if the block
2424 * is reference counted. we should use do_relocation() in this
2425 * case. return a tree root pointer if the block isn't reference
2426 * counted. return -ENOENT if the block is root of reloc tree.
2428 static noinline_for_stack
2429 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2430 struct backref_node *node)
2432 struct backref_node *next;
2433 struct btrfs_root *root;
2434 struct btrfs_root *fs_root = NULL;
2435 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2441 next = walk_up_backref(next, edges, &index);
2445 /* no other choice for non-references counted tree */
2446 if (!root->ref_cows)
2449 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2455 next = walk_down_backref(edges, &index);
2456 if (!next || next->level <= node->level)
2461 return ERR_PTR(-ENOENT);
2465 static noinline_for_stack
2466 u64 calcu_metadata_size(struct reloc_control *rc,
2467 struct backref_node *node, int reserve)
2469 struct backref_node *next = node;
2470 struct backref_edge *edge;
2471 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2475 BUG_ON(reserve && node->processed);
2480 if (next->processed && (reserve || next != node))
2483 num_bytes += btrfs_level_size(rc->extent_root,
2486 if (list_empty(&next->upper))
2489 edge = list_entry(next->upper.next,
2490 struct backref_edge, list[LOWER]);
2491 edges[index++] = edge;
2492 next = edge->node[UPPER];
2494 next = walk_down_backref(edges, &index);
2499 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2500 struct reloc_control *rc,
2501 struct backref_node *node)
2503 struct btrfs_root *root = rc->extent_root;
2507 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2509 trans->block_rsv = rc->block_rsv;
2510 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2511 BTRFS_RESERVE_FLUSH_ALL);
2514 rc->commit_transaction = 1;
2521 static void release_metadata_space(struct reloc_control *rc,
2522 struct backref_node *node)
2524 u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2;
2525 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes);
2529 * relocate a block tree, and then update pointers in upper level
2530 * blocks that reference the block to point to the new location.
2532 * if called by link_to_upper, the block has already been relocated.
2533 * in that case this function just updates pointers.
2535 static int do_relocation(struct btrfs_trans_handle *trans,
2536 struct reloc_control *rc,
2537 struct backref_node *node,
2538 struct btrfs_key *key,
2539 struct btrfs_path *path, int lowest)
2541 struct backref_node *upper;
2542 struct backref_edge *edge;
2543 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2544 struct btrfs_root *root;
2545 struct extent_buffer *eb;
2554 BUG_ON(lowest && node->eb);
2556 path->lowest_level = node->level + 1;
2557 rc->backref_cache.path[node->level] = node;
2558 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2561 upper = edge->node[UPPER];
2562 root = select_reloc_root(trans, rc, upper, edges, &nr);
2565 if (upper->eb && !upper->locked) {
2567 ret = btrfs_bin_search(upper->eb, key,
2568 upper->level, &slot);
2570 bytenr = btrfs_node_blockptr(upper->eb, slot);
2571 if (node->eb->start == bytenr)
2574 drop_node_buffer(upper);
2578 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2586 upper->eb = path->nodes[upper->level];
2587 path->nodes[upper->level] = NULL;
2589 BUG_ON(upper->eb != path->nodes[upper->level]);
2593 path->locks[upper->level] = 0;
2595 slot = path->slots[upper->level];
2596 btrfs_release_path(path);
2598 ret = btrfs_bin_search(upper->eb, key, upper->level,
2603 bytenr = btrfs_node_blockptr(upper->eb, slot);
2605 BUG_ON(bytenr != node->bytenr);
2607 if (node->eb->start == bytenr)
2611 blocksize = btrfs_level_size(root, node->level);
2612 generation = btrfs_node_ptr_generation(upper->eb, slot);
2613 eb = read_tree_block(root, bytenr, blocksize, generation);
2614 if (!eb || !extent_buffer_uptodate(eb)) {
2615 free_extent_buffer(eb);
2619 btrfs_tree_lock(eb);
2620 btrfs_set_lock_blocking(eb);
2623 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2625 btrfs_tree_unlock(eb);
2626 free_extent_buffer(eb);
2631 BUG_ON(node->eb != eb);
2633 btrfs_set_node_blockptr(upper->eb, slot,
2635 btrfs_set_node_ptr_generation(upper->eb, slot,
2637 btrfs_mark_buffer_dirty(upper->eb);
2639 ret = btrfs_inc_extent_ref(trans, root,
2640 node->eb->start, blocksize,
2642 btrfs_header_owner(upper->eb),
2646 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2650 if (!upper->pending)
2651 drop_node_buffer(upper);
2653 unlock_node_buffer(upper);
2658 if (!err && node->pending) {
2659 drop_node_buffer(node);
2660 list_move_tail(&node->list, &rc->backref_cache.changed);
2664 path->lowest_level = 0;
2665 BUG_ON(err == -ENOSPC);
2669 static int link_to_upper(struct btrfs_trans_handle *trans,
2670 struct reloc_control *rc,
2671 struct backref_node *node,
2672 struct btrfs_path *path)
2674 struct btrfs_key key;
2676 btrfs_node_key_to_cpu(node->eb, &key, 0);
2677 return do_relocation(trans, rc, node, &key, path, 0);
2680 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2681 struct reloc_control *rc,
2682 struct btrfs_path *path, int err)
2685 struct backref_cache *cache = &rc->backref_cache;
2686 struct backref_node *node;
2690 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2691 while (!list_empty(&cache->pending[level])) {
2692 node = list_entry(cache->pending[level].next,
2693 struct backref_node, list);
2694 list_move_tail(&node->list, &list);
2695 BUG_ON(!node->pending);
2698 ret = link_to_upper(trans, rc, node, path);
2703 list_splice_init(&list, &cache->pending[level]);
2708 static void mark_block_processed(struct reloc_control *rc,
2709 u64 bytenr, u32 blocksize)
2711 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2712 EXTENT_DIRTY, GFP_NOFS);
2715 static void __mark_block_processed(struct reloc_control *rc,
2716 struct backref_node *node)
2719 if (node->level == 0 ||
2720 in_block_group(node->bytenr, rc->block_group)) {
2721 blocksize = btrfs_level_size(rc->extent_root, node->level);
2722 mark_block_processed(rc, node->bytenr, blocksize);
2724 node->processed = 1;
2728 * mark a block and all blocks directly/indirectly reference the block
2731 static void update_processed_blocks(struct reloc_control *rc,
2732 struct backref_node *node)
2734 struct backref_node *next = node;
2735 struct backref_edge *edge;
2736 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2742 if (next->processed)
2745 __mark_block_processed(rc, next);
2747 if (list_empty(&next->upper))
2750 edge = list_entry(next->upper.next,
2751 struct backref_edge, list[LOWER]);
2752 edges[index++] = edge;
2753 next = edge->node[UPPER];
2755 next = walk_down_backref(edges, &index);
2759 static int tree_block_processed(u64 bytenr, u32 blocksize,
2760 struct reloc_control *rc)
2762 if (test_range_bit(&rc->processed_blocks, bytenr,
2763 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2768 static int get_tree_block_key(struct reloc_control *rc,
2769 struct tree_block *block)
2771 struct extent_buffer *eb;
2773 BUG_ON(block->key_ready);
2774 eb = read_tree_block(rc->extent_root, block->bytenr,
2775 block->key.objectid, block->key.offset);
2776 if (!eb || !extent_buffer_uptodate(eb)) {
2777 free_extent_buffer(eb);
2780 WARN_ON(btrfs_header_level(eb) != block->level);
2781 if (block->level == 0)
2782 btrfs_item_key_to_cpu(eb, &block->key, 0);
2784 btrfs_node_key_to_cpu(eb, &block->key, 0);
2785 free_extent_buffer(eb);
2786 block->key_ready = 1;
2790 static int reada_tree_block(struct reloc_control *rc,
2791 struct tree_block *block)
2793 BUG_ON(block->key_ready);
2794 if (block->key.type == BTRFS_METADATA_ITEM_KEY)
2795 readahead_tree_block(rc->extent_root, block->bytenr,
2796 block->key.objectid,
2797 rc->extent_root->leafsize);
2799 readahead_tree_block(rc->extent_root, block->bytenr,
2800 block->key.objectid, block->key.offset);
2805 * helper function to relocate a tree block
2807 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2808 struct reloc_control *rc,
2809 struct backref_node *node,
2810 struct btrfs_key *key,
2811 struct btrfs_path *path)
2813 struct btrfs_root *root;
2820 BUG_ON(node->processed);
2821 root = select_one_root(trans, node);
2822 if (root == ERR_PTR(-ENOENT)) {
2823 update_processed_blocks(rc, node);
2827 if (!root || root->ref_cows) {
2828 ret = reserve_metadata_space(trans, rc, node);
2835 if (root->ref_cows) {
2836 BUG_ON(node->new_bytenr);
2837 BUG_ON(!list_empty(&node->list));
2838 btrfs_record_root_in_trans(trans, root);
2839 root = root->reloc_root;
2840 node->new_bytenr = root->node->start;
2842 list_add_tail(&node->list, &rc->backref_cache.changed);
2844 path->lowest_level = node->level;
2845 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2846 btrfs_release_path(path);
2851 update_processed_blocks(rc, node);
2853 ret = do_relocation(trans, rc, node, key, path, 1);
2856 if (ret || node->level == 0 || node->cowonly) {
2858 release_metadata_space(rc, node);
2859 remove_backref_node(&rc->backref_cache, node);
2865 * relocate a list of blocks
2867 static noinline_for_stack
2868 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2869 struct reloc_control *rc, struct rb_root *blocks)
2871 struct backref_node *node;
2872 struct btrfs_path *path;
2873 struct tree_block *block;
2874 struct rb_node *rb_node;
2878 path = btrfs_alloc_path();
2881 goto out_free_blocks;
2884 rb_node = rb_first(blocks);
2886 block = rb_entry(rb_node, struct tree_block, rb_node);
2887 if (!block->key_ready)
2888 reada_tree_block(rc, block);
2889 rb_node = rb_next(rb_node);
2892 rb_node = rb_first(blocks);
2894 block = rb_entry(rb_node, struct tree_block, rb_node);
2895 if (!block->key_ready) {
2896 err = get_tree_block_key(rc, block);
2900 rb_node = rb_next(rb_node);
2903 rb_node = rb_first(blocks);
2905 block = rb_entry(rb_node, struct tree_block, rb_node);
2907 node = build_backref_tree(rc, &block->key,
2908 block->level, block->bytenr);
2910 err = PTR_ERR(node);
2914 ret = relocate_tree_block(trans, rc, node, &block->key,
2917 if (ret != -EAGAIN || rb_node == rb_first(blocks))
2921 rb_node = rb_next(rb_node);
2924 err = finish_pending_nodes(trans, rc, path, err);
2927 btrfs_free_path(path);
2929 free_block_list(blocks);
2933 static noinline_for_stack
2934 int prealloc_file_extent_cluster(struct inode *inode,
2935 struct file_extent_cluster *cluster)
2940 u64 offset = BTRFS_I(inode)->index_cnt;
2945 BUG_ON(cluster->start != cluster->boundary[0]);
2946 mutex_lock(&inode->i_mutex);
2948 ret = btrfs_check_data_free_space(inode, cluster->end +
2949 1 - cluster->start);
2953 while (nr < cluster->nr) {
2954 start = cluster->boundary[nr] - offset;
2955 if (nr + 1 < cluster->nr)
2956 end = cluster->boundary[nr + 1] - 1 - offset;
2958 end = cluster->end - offset;
2960 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2961 num_bytes = end + 1 - start;
2962 ret = btrfs_prealloc_file_range(inode, 0, start,
2963 num_bytes, num_bytes,
2964 end + 1, &alloc_hint);
2965 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2970 btrfs_free_reserved_data_space(inode, cluster->end +
2971 1 - cluster->start);
2973 mutex_unlock(&inode->i_mutex);
2977 static noinline_for_stack
2978 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
2981 struct btrfs_root *root = BTRFS_I(inode)->root;
2982 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2983 struct extent_map *em;
2986 em = alloc_extent_map();
2991 em->len = end + 1 - start;
2992 em->block_len = em->len;
2993 em->block_start = block_start;
2994 em->bdev = root->fs_info->fs_devices->latest_bdev;
2995 set_bit(EXTENT_FLAG_PINNED, &em->flags);
2997 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2999 write_lock(&em_tree->lock);
3000 ret = add_extent_mapping(em_tree, em, 0);
3001 write_unlock(&em_tree->lock);
3002 if (ret != -EEXIST) {
3003 free_extent_map(em);
3006 btrfs_drop_extent_cache(inode, start, end, 0);
3008 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3012 static int relocate_file_extent_cluster(struct inode *inode,
3013 struct file_extent_cluster *cluster)
3017 u64 offset = BTRFS_I(inode)->index_cnt;
3018 unsigned long index;
3019 unsigned long last_index;
3021 struct file_ra_state *ra;
3022 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3029 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3033 ret = prealloc_file_extent_cluster(inode, cluster);
3037 file_ra_state_init(ra, inode->i_mapping);
3039 ret = setup_extent_mapping(inode, cluster->start - offset,
3040 cluster->end - offset, cluster->start);
3044 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
3045 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
3046 while (index <= last_index) {
3047 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
3051 page = find_lock_page(inode->i_mapping, index);
3053 page_cache_sync_readahead(inode->i_mapping,
3055 last_index + 1 - index);
3056 page = find_or_create_page(inode->i_mapping, index,
3059 btrfs_delalloc_release_metadata(inode,
3066 if (PageReadahead(page)) {
3067 page_cache_async_readahead(inode->i_mapping,
3068 ra, NULL, page, index,
3069 last_index + 1 - index);
3072 if (!PageUptodate(page)) {
3073 btrfs_readpage(NULL, page);
3075 if (!PageUptodate(page)) {
3077 page_cache_release(page);
3078 btrfs_delalloc_release_metadata(inode,
3085 page_start = page_offset(page);
3086 page_end = page_start + PAGE_CACHE_SIZE - 1;
3088 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3090 set_page_extent_mapped(page);
3092 if (nr < cluster->nr &&
3093 page_start + offset == cluster->boundary[nr]) {
3094 set_extent_bits(&BTRFS_I(inode)->io_tree,
3095 page_start, page_end,
3096 EXTENT_BOUNDARY, GFP_NOFS);
3100 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
3101 set_page_dirty(page);
3103 unlock_extent(&BTRFS_I(inode)->io_tree,
3104 page_start, page_end);
3106 page_cache_release(page);
3109 balance_dirty_pages_ratelimited(inode->i_mapping);
3110 btrfs_throttle(BTRFS_I(inode)->root);
3112 WARN_ON(nr != cluster->nr);
3118 static noinline_for_stack
3119 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3120 struct file_extent_cluster *cluster)
3124 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3125 ret = relocate_file_extent_cluster(inode, cluster);
3132 cluster->start = extent_key->objectid;
3134 BUG_ON(cluster->nr >= MAX_EXTENTS);
3135 cluster->end = extent_key->objectid + extent_key->offset - 1;
3136 cluster->boundary[cluster->nr] = extent_key->objectid;
3139 if (cluster->nr >= MAX_EXTENTS) {
3140 ret = relocate_file_extent_cluster(inode, cluster);
3148 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3149 static int get_ref_objectid_v0(struct reloc_control *rc,
3150 struct btrfs_path *path,
3151 struct btrfs_key *extent_key,
3152 u64 *ref_objectid, int *path_change)
3154 struct btrfs_key key;
3155 struct extent_buffer *leaf;
3156 struct btrfs_extent_ref_v0 *ref0;
3160 leaf = path->nodes[0];
3161 slot = path->slots[0];
3163 if (slot >= btrfs_header_nritems(leaf)) {
3164 ret = btrfs_next_leaf(rc->extent_root, path);
3168 leaf = path->nodes[0];
3169 slot = path->slots[0];
3173 btrfs_item_key_to_cpu(leaf, &key, slot);
3174 if (key.objectid != extent_key->objectid)
3177 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3181 ref0 = btrfs_item_ptr(leaf, slot,
3182 struct btrfs_extent_ref_v0);
3183 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3191 * helper to add a tree block to the list.
3192 * the major work is getting the generation and level of the block
3194 static int add_tree_block(struct reloc_control *rc,
3195 struct btrfs_key *extent_key,
3196 struct btrfs_path *path,
3197 struct rb_root *blocks)
3199 struct extent_buffer *eb;
3200 struct btrfs_extent_item *ei;
3201 struct btrfs_tree_block_info *bi;
3202 struct tree_block *block;
3203 struct rb_node *rb_node;
3208 eb = path->nodes[0];
3209 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3211 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3212 item_size >= sizeof(*ei) + sizeof(*bi)) {
3213 ei = btrfs_item_ptr(eb, path->slots[0],
3214 struct btrfs_extent_item);
3215 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3216 bi = (struct btrfs_tree_block_info *)(ei + 1);
3217 level = btrfs_tree_block_level(eb, bi);
3219 level = (int)extent_key->offset;
3221 generation = btrfs_extent_generation(eb, ei);
3223 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3227 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3228 ret = get_ref_objectid_v0(rc, path, extent_key,
3232 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3233 level = (int)ref_owner;
3234 /* FIXME: get real generation */
3241 btrfs_release_path(path);
3243 BUG_ON(level == -1);
3245 block = kmalloc(sizeof(*block), GFP_NOFS);
3249 block->bytenr = extent_key->objectid;
3250 block->key.objectid = rc->extent_root->leafsize;
3251 block->key.offset = generation;
3252 block->level = level;
3253 block->key_ready = 0;
3255 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3257 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3263 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3265 static int __add_tree_block(struct reloc_control *rc,
3266 u64 bytenr, u32 blocksize,
3267 struct rb_root *blocks)
3269 struct btrfs_path *path;
3270 struct btrfs_key key;
3273 if (tree_block_processed(bytenr, blocksize, rc))
3276 if (tree_search(blocks, bytenr))
3279 path = btrfs_alloc_path();
3283 key.objectid = bytenr;
3284 key.type = BTRFS_EXTENT_ITEM_KEY;
3285 key.offset = blocksize;
3287 path->search_commit_root = 1;
3288 path->skip_locking = 1;
3289 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3293 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3295 if (key.objectid == bytenr &&
3296 key.type == BTRFS_METADATA_ITEM_KEY)
3301 ret = add_tree_block(rc, &key, path, blocks);
3303 btrfs_free_path(path);
3308 * helper to check if the block use full backrefs for pointers in it
3310 static int block_use_full_backref(struct reloc_control *rc,
3311 struct extent_buffer *eb)
3316 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3317 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3320 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3321 eb->start, btrfs_header_level(eb), 1,
3325 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3332 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3333 struct inode *inode, u64 ino)
3335 struct btrfs_key key;
3336 struct btrfs_path *path;
3337 struct btrfs_root *root = fs_info->tree_root;
3338 struct btrfs_trans_handle *trans;
3345 key.type = BTRFS_INODE_ITEM_KEY;
3348 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3349 if (IS_ERR(inode) || is_bad_inode(inode)) {
3356 ret = btrfs_check_trunc_cache_free_space(root,
3357 &fs_info->global_block_rsv);
3361 path = btrfs_alloc_path();
3367 trans = btrfs_join_transaction(root);
3368 if (IS_ERR(trans)) {
3369 btrfs_free_path(path);
3370 ret = PTR_ERR(trans);
3374 ret = btrfs_truncate_free_space_cache(root, trans, path, inode);
3376 btrfs_free_path(path);
3377 btrfs_end_transaction(trans, root);
3378 btrfs_btree_balance_dirty(root);
3385 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3386 * this function scans fs tree to find blocks reference the data extent
3388 static int find_data_references(struct reloc_control *rc,
3389 struct btrfs_key *extent_key,
3390 struct extent_buffer *leaf,
3391 struct btrfs_extent_data_ref *ref,
3392 struct rb_root *blocks)
3394 struct btrfs_path *path;
3395 struct tree_block *block;
3396 struct btrfs_root *root;
3397 struct btrfs_file_extent_item *fi;
3398 struct rb_node *rb_node;
3399 struct btrfs_key key;
3410 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3411 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3412 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3413 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3416 * This is an extent belonging to the free space cache, lets just delete
3417 * it and redo the search.
3419 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3420 ret = delete_block_group_cache(rc->extent_root->fs_info,
3421 NULL, ref_objectid);
3427 path = btrfs_alloc_path();
3432 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3434 err = PTR_ERR(root);
3438 key.objectid = ref_objectid;
3439 key.type = BTRFS_EXTENT_DATA_KEY;
3440 if (ref_offset > ((u64)-1 << 32))
3443 key.offset = ref_offset;
3445 path->search_commit_root = 1;
3446 path->skip_locking = 1;
3447 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3453 leaf = path->nodes[0];
3454 nritems = btrfs_header_nritems(leaf);
3456 * the references in tree blocks that use full backrefs
3457 * are not counted in
3459 if (block_use_full_backref(rc, leaf))
3463 rb_node = tree_search(blocks, leaf->start);
3468 path->slots[0] = nritems;
3471 while (ref_count > 0) {
3472 while (path->slots[0] >= nritems) {
3473 ret = btrfs_next_leaf(root, path);
3483 leaf = path->nodes[0];
3484 nritems = btrfs_header_nritems(leaf);
3487 if (block_use_full_backref(rc, leaf))
3491 rb_node = tree_search(blocks, leaf->start);
3496 path->slots[0] = nritems;
3500 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3501 if (key.objectid != ref_objectid ||
3502 key.type != BTRFS_EXTENT_DATA_KEY) {
3507 fi = btrfs_item_ptr(leaf, path->slots[0],
3508 struct btrfs_file_extent_item);
3510 if (btrfs_file_extent_type(leaf, fi) ==
3511 BTRFS_FILE_EXTENT_INLINE)
3514 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3515 extent_key->objectid)
3518 key.offset -= btrfs_file_extent_offset(leaf, fi);
3519 if (key.offset != ref_offset)
3527 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3528 block = kmalloc(sizeof(*block), GFP_NOFS);
3533 block->bytenr = leaf->start;
3534 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3536 block->key_ready = 1;
3537 rb_node = tree_insert(blocks, block->bytenr,
3540 backref_tree_panic(rb_node, -EEXIST,
3546 path->slots[0] = nritems;
3552 btrfs_free_path(path);
3557 * helper to find all tree blocks that reference a given data extent
3559 static noinline_for_stack
3560 int add_data_references(struct reloc_control *rc,
3561 struct btrfs_key *extent_key,
3562 struct btrfs_path *path,
3563 struct rb_root *blocks)
3565 struct btrfs_key key;
3566 struct extent_buffer *eb;
3567 struct btrfs_extent_data_ref *dref;
3568 struct btrfs_extent_inline_ref *iref;
3571 u32 blocksize = btrfs_level_size(rc->extent_root, 0);
3575 eb = path->nodes[0];
3576 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3577 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3578 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3579 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3583 ptr += sizeof(struct btrfs_extent_item);
3586 iref = (struct btrfs_extent_inline_ref *)ptr;
3587 key.type = btrfs_extent_inline_ref_type(eb, iref);
3588 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3589 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3590 ret = __add_tree_block(rc, key.offset, blocksize,
3592 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3593 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3594 ret = find_data_references(rc, extent_key,
3599 ptr += btrfs_extent_inline_ref_size(key.type);
3605 eb = path->nodes[0];
3606 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3607 ret = btrfs_next_leaf(rc->extent_root, path);
3614 eb = path->nodes[0];
3617 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3618 if (key.objectid != extent_key->objectid)
3621 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3622 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3623 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3625 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3626 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3628 ret = __add_tree_block(rc, key.offset, blocksize,
3630 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3631 dref = btrfs_item_ptr(eb, path->slots[0],
3632 struct btrfs_extent_data_ref);
3633 ret = find_data_references(rc, extent_key,
3644 btrfs_release_path(path);
3646 free_block_list(blocks);
3651 * helper to find next unprocessed extent
3653 static noinline_for_stack
3654 int find_next_extent(struct btrfs_trans_handle *trans,
3655 struct reloc_control *rc, struct btrfs_path *path,
3656 struct btrfs_key *extent_key)
3658 struct btrfs_key key;
3659 struct extent_buffer *leaf;
3660 u64 start, end, last;
3663 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3666 if (rc->search_start >= last) {
3671 key.objectid = rc->search_start;
3672 key.type = BTRFS_EXTENT_ITEM_KEY;
3675 path->search_commit_root = 1;
3676 path->skip_locking = 1;
3677 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3682 leaf = path->nodes[0];
3683 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3684 ret = btrfs_next_leaf(rc->extent_root, path);
3687 leaf = path->nodes[0];
3690 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3691 if (key.objectid >= last) {
3696 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3697 key.type != BTRFS_METADATA_ITEM_KEY) {
3702 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3703 key.objectid + key.offset <= rc->search_start) {
3708 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3709 key.objectid + rc->extent_root->leafsize <=
3715 ret = find_first_extent_bit(&rc->processed_blocks,
3716 key.objectid, &start, &end,
3717 EXTENT_DIRTY, NULL);
3719 if (ret == 0 && start <= key.objectid) {
3720 btrfs_release_path(path);
3721 rc->search_start = end + 1;
3723 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3724 rc->search_start = key.objectid + key.offset;
3726 rc->search_start = key.objectid +
3727 rc->extent_root->leafsize;
3728 memcpy(extent_key, &key, sizeof(key));
3732 btrfs_release_path(path);
3736 static void set_reloc_control(struct reloc_control *rc)
3738 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3740 mutex_lock(&fs_info->reloc_mutex);
3741 fs_info->reloc_ctl = rc;
3742 mutex_unlock(&fs_info->reloc_mutex);
3745 static void unset_reloc_control(struct reloc_control *rc)
3747 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3749 mutex_lock(&fs_info->reloc_mutex);
3750 fs_info->reloc_ctl = NULL;
3751 mutex_unlock(&fs_info->reloc_mutex);
3754 static int check_extent_flags(u64 flags)
3756 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3757 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3759 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3760 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3762 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3763 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3768 static noinline_for_stack
3769 int prepare_to_relocate(struct reloc_control *rc)
3771 struct btrfs_trans_handle *trans;
3774 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root,
3775 BTRFS_BLOCK_RSV_TEMP);
3780 * reserve some space for creating reloc trees.
3781 * btrfs_init_reloc_root will use them when there
3782 * is no reservation in transaction handle.
3784 ret = btrfs_block_rsv_add(rc->extent_root, rc->block_rsv,
3785 rc->extent_root->nodesize * 256,
3786 BTRFS_RESERVE_FLUSH_ALL);
3790 memset(&rc->cluster, 0, sizeof(rc->cluster));
3791 rc->search_start = rc->block_group->key.objectid;
3792 rc->extents_found = 0;
3793 rc->nodes_relocated = 0;
3794 rc->merging_rsv_size = 0;
3796 rc->create_reloc_tree = 1;
3797 set_reloc_control(rc);
3799 trans = btrfs_join_transaction(rc->extent_root);
3800 if (IS_ERR(trans)) {
3801 unset_reloc_control(rc);
3803 * extent tree is not a ref_cow tree and has no reloc_root to
3804 * cleanup. And callers are responsible to free the above
3807 return PTR_ERR(trans);
3809 btrfs_commit_transaction(trans, rc->extent_root);
3813 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3815 struct rb_root blocks = RB_ROOT;
3816 struct btrfs_key key;
3817 struct btrfs_trans_handle *trans = NULL;
3818 struct btrfs_path *path;
3819 struct btrfs_extent_item *ei;
3826 path = btrfs_alloc_path();
3831 ret = prepare_to_relocate(rc);
3839 trans = btrfs_start_transaction(rc->extent_root, 0);
3840 if (IS_ERR(trans)) {
3841 err = PTR_ERR(trans);
3846 if (update_backref_cache(trans, &rc->backref_cache)) {
3847 btrfs_end_transaction(trans, rc->extent_root);
3851 ret = find_next_extent(trans, rc, path, &key);
3857 rc->extents_found++;
3859 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3860 struct btrfs_extent_item);
3861 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3862 if (item_size >= sizeof(*ei)) {
3863 flags = btrfs_extent_flags(path->nodes[0], ei);
3864 ret = check_extent_flags(flags);
3868 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3870 int path_change = 0;
3873 sizeof(struct btrfs_extent_item_v0));
3874 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3876 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3877 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3879 flags = BTRFS_EXTENT_FLAG_DATA;
3882 btrfs_release_path(path);
3884 path->search_commit_root = 1;
3885 path->skip_locking = 1;
3886 ret = btrfs_search_slot(NULL, rc->extent_root,
3899 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3900 ret = add_tree_block(rc, &key, path, &blocks);
3901 } else if (rc->stage == UPDATE_DATA_PTRS &&
3902 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3903 ret = add_data_references(rc, &key, path, &blocks);
3905 btrfs_release_path(path);
3913 if (!RB_EMPTY_ROOT(&blocks)) {
3914 ret = relocate_tree_blocks(trans, rc, &blocks);
3916 if (ret != -EAGAIN) {
3920 rc->extents_found--;
3921 rc->search_start = key.objectid;
3925 ret = btrfs_block_rsv_check(rc->extent_root, rc->block_rsv, 5);
3927 if (ret != -ENOSPC) {
3932 rc->commit_transaction = 1;
3935 if (rc->commit_transaction) {
3936 rc->commit_transaction = 0;
3937 ret = btrfs_commit_transaction(trans, rc->extent_root);
3940 btrfs_end_transaction_throttle(trans, rc->extent_root);
3941 btrfs_btree_balance_dirty(rc->extent_root);
3945 if (rc->stage == MOVE_DATA_EXTENTS &&
3946 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3947 rc->found_file_extent = 1;
3948 ret = relocate_data_extent(rc->data_inode,
3949 &key, &rc->cluster);
3956 if (trans && progress && err == -ENOSPC) {
3957 ret = btrfs_force_chunk_alloc(trans, rc->extent_root,
3958 rc->block_group->flags);
3966 btrfs_release_path(path);
3967 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
3971 btrfs_end_transaction_throttle(trans, rc->extent_root);
3972 btrfs_btree_balance_dirty(rc->extent_root);
3976 ret = relocate_file_extent_cluster(rc->data_inode,
3982 rc->create_reloc_tree = 0;
3983 set_reloc_control(rc);
3985 backref_cache_cleanup(&rc->backref_cache);
3986 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3988 err = prepare_to_merge(rc, err);
3990 merge_reloc_roots(rc);
3992 rc->merge_reloc_tree = 0;
3993 unset_reloc_control(rc);
3994 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3996 /* get rid of pinned extents */
3997 trans = btrfs_join_transaction(rc->extent_root);
3999 err = PTR_ERR(trans);
4001 btrfs_commit_transaction(trans, rc->extent_root);
4003 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
4004 btrfs_free_path(path);
4008 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4009 struct btrfs_root *root, u64 objectid)
4011 struct btrfs_path *path;
4012 struct btrfs_inode_item *item;
4013 struct extent_buffer *leaf;
4016 path = btrfs_alloc_path();
4020 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4024 leaf = path->nodes[0];
4025 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4026 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
4027 btrfs_set_inode_generation(leaf, item, 1);
4028 btrfs_set_inode_size(leaf, item, 0);
4029 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4030 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4031 BTRFS_INODE_PREALLOC);
4032 btrfs_mark_buffer_dirty(leaf);
4033 btrfs_release_path(path);
4035 btrfs_free_path(path);
4040 * helper to create inode for data relocation.
4041 * the inode is in data relocation tree and its link count is 0
4043 static noinline_for_stack
4044 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4045 struct btrfs_block_group_cache *group)
4047 struct inode *inode = NULL;
4048 struct btrfs_trans_handle *trans;
4049 struct btrfs_root *root;
4050 struct btrfs_key key;
4051 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
4054 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4056 return ERR_CAST(root);
4058 trans = btrfs_start_transaction(root, 6);
4060 return ERR_CAST(trans);
4062 err = btrfs_find_free_objectid(root, &objectid);
4066 err = __insert_orphan_inode(trans, root, objectid);
4069 key.objectid = objectid;
4070 key.type = BTRFS_INODE_ITEM_KEY;
4072 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
4073 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4074 BTRFS_I(inode)->index_cnt = group->key.objectid;
4076 err = btrfs_orphan_add(trans, inode);
4078 btrfs_end_transaction(trans, root);
4079 btrfs_btree_balance_dirty(root);
4083 inode = ERR_PTR(err);
4088 static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info)
4090 struct reloc_control *rc;
4092 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4096 INIT_LIST_HEAD(&rc->reloc_roots);
4097 backref_cache_init(&rc->backref_cache);
4098 mapping_tree_init(&rc->reloc_root_tree);
4099 extent_io_tree_init(&rc->processed_blocks,
4100 fs_info->btree_inode->i_mapping);
4105 * function to relocate all extents in a block group.
4107 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
4109 struct btrfs_fs_info *fs_info = extent_root->fs_info;
4110 struct reloc_control *rc;
4111 struct inode *inode;
4112 struct btrfs_path *path;
4117 rc = alloc_reloc_control(fs_info);
4121 rc->extent_root = extent_root;
4123 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4124 BUG_ON(!rc->block_group);
4126 if (!rc->block_group->ro) {
4127 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
4135 path = btrfs_alloc_path();
4141 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
4143 btrfs_free_path(path);
4146 ret = delete_block_group_cache(fs_info, inode, 0);
4148 ret = PTR_ERR(inode);
4150 if (ret && ret != -ENOENT) {
4155 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4156 if (IS_ERR(rc->data_inode)) {
4157 err = PTR_ERR(rc->data_inode);
4158 rc->data_inode = NULL;
4162 printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n",
4163 (unsigned long long)rc->block_group->key.objectid,
4164 (unsigned long long)rc->block_group->flags);
4166 ret = btrfs_start_delalloc_inodes(fs_info->tree_root, 0);
4171 btrfs_wait_ordered_extents(fs_info->tree_root, 0);
4174 mutex_lock(&fs_info->cleaner_mutex);
4175 ret = relocate_block_group(rc);
4176 mutex_unlock(&fs_info->cleaner_mutex);
4182 if (rc->extents_found == 0)
4185 printk(KERN_INFO "btrfs: found %llu extents\n",
4186 (unsigned long long)rc->extents_found);
4188 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4189 btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1);
4190 invalidate_mapping_pages(rc->data_inode->i_mapping,
4192 rc->stage = UPDATE_DATA_PTRS;
4196 filemap_write_and_wait_range(fs_info->btree_inode->i_mapping,
4197 rc->block_group->key.objectid,
4198 rc->block_group->key.objectid +
4199 rc->block_group->key.offset - 1);
4201 WARN_ON(rc->block_group->pinned > 0);
4202 WARN_ON(rc->block_group->reserved > 0);
4203 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4206 btrfs_set_block_group_rw(extent_root, rc->block_group);
4207 iput(rc->data_inode);
4208 btrfs_put_block_group(rc->block_group);
4213 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4215 struct btrfs_trans_handle *trans;
4218 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4220 return PTR_ERR(trans);
4222 memset(&root->root_item.drop_progress, 0,
4223 sizeof(root->root_item.drop_progress));
4224 root->root_item.drop_level = 0;
4225 btrfs_set_root_refs(&root->root_item, 0);
4226 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4227 &root->root_key, &root->root_item);
4229 err = btrfs_end_transaction(trans, root->fs_info->tree_root);
4236 * recover relocation interrupted by system crash.
4238 * this function resumes merging reloc trees with corresponding fs trees.
4239 * this is important for keeping the sharing of tree blocks
4241 int btrfs_recover_relocation(struct btrfs_root *root)
4243 LIST_HEAD(reloc_roots);
4244 struct btrfs_key key;
4245 struct btrfs_root *fs_root;
4246 struct btrfs_root *reloc_root;
4247 struct btrfs_path *path;
4248 struct extent_buffer *leaf;
4249 struct reloc_control *rc = NULL;
4250 struct btrfs_trans_handle *trans;
4254 path = btrfs_alloc_path();
4259 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4260 key.type = BTRFS_ROOT_ITEM_KEY;
4261 key.offset = (u64)-1;
4264 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4271 if (path->slots[0] == 0)
4275 leaf = path->nodes[0];
4276 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4277 btrfs_release_path(path);
4279 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4280 key.type != BTRFS_ROOT_ITEM_KEY)
4283 reloc_root = btrfs_read_fs_root_no_radix(root, &key);
4284 if (IS_ERR(reloc_root)) {
4285 err = PTR_ERR(reloc_root);
4289 list_add(&reloc_root->root_list, &reloc_roots);
4291 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4292 fs_root = read_fs_root(root->fs_info,
4293 reloc_root->root_key.offset);
4294 if (IS_ERR(fs_root)) {
4295 ret = PTR_ERR(fs_root);
4296 if (ret != -ENOENT) {
4300 ret = mark_garbage_root(reloc_root);
4308 if (key.offset == 0)
4313 btrfs_release_path(path);
4315 if (list_empty(&reloc_roots))
4318 rc = alloc_reloc_control(root->fs_info);
4324 rc->extent_root = root->fs_info->extent_root;
4326 set_reloc_control(rc);
4328 trans = btrfs_join_transaction(rc->extent_root);
4329 if (IS_ERR(trans)) {
4330 unset_reloc_control(rc);
4331 err = PTR_ERR(trans);
4335 rc->merge_reloc_tree = 1;
4337 while (!list_empty(&reloc_roots)) {
4338 reloc_root = list_entry(reloc_roots.next,
4339 struct btrfs_root, root_list);
4340 list_del(&reloc_root->root_list);
4342 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4343 list_add_tail(&reloc_root->root_list,
4348 fs_root = read_fs_root(root->fs_info,
4349 reloc_root->root_key.offset);
4350 if (IS_ERR(fs_root)) {
4351 err = PTR_ERR(fs_root);
4355 err = __add_reloc_root(reloc_root);
4356 BUG_ON(err < 0); /* -ENOMEM or logic error */
4357 fs_root->reloc_root = reloc_root;
4360 err = btrfs_commit_transaction(trans, rc->extent_root);
4364 merge_reloc_roots(rc);
4366 unset_reloc_control(rc);
4368 trans = btrfs_join_transaction(rc->extent_root);
4370 err = PTR_ERR(trans);
4372 err = btrfs_commit_transaction(trans, rc->extent_root);
4376 if (!list_empty(&reloc_roots))
4377 free_reloc_roots(&reloc_roots);
4379 btrfs_free_path(path);
4382 /* cleanup orphan inode in data relocation tree */
4383 fs_root = read_fs_root(root->fs_info,
4384 BTRFS_DATA_RELOC_TREE_OBJECTID);
4385 if (IS_ERR(fs_root))
4386 err = PTR_ERR(fs_root);
4388 err = btrfs_orphan_cleanup(fs_root);
4394 * helper to add ordered checksum for data relocation.
4396 * cloning checksum properly handles the nodatasum extents.
4397 * it also saves CPU time to re-calculate the checksum.
4399 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4401 struct btrfs_ordered_sum *sums;
4402 struct btrfs_sector_sum *sector_sum;
4403 struct btrfs_ordered_extent *ordered;
4404 struct btrfs_root *root = BTRFS_I(inode)->root;
4410 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4411 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4413 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4414 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4415 disk_bytenr + len - 1, &list, 0);
4419 while (!list_empty(&list)) {
4420 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4421 list_del_init(&sums->list);
4423 sector_sum = sums->sums;
4424 sums->bytenr = ordered->start;
4427 while (offset < sums->len) {
4428 sector_sum->bytenr += ordered->start - disk_bytenr;
4430 offset += root->sectorsize;
4433 btrfs_add_ordered_sum(inode, ordered, sums);
4436 btrfs_put_ordered_extent(ordered);
4440 void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4441 struct btrfs_root *root, struct extent_buffer *buf,
4442 struct extent_buffer *cow)
4444 struct reloc_control *rc;
4445 struct backref_node *node;
4450 rc = root->fs_info->reloc_ctl;
4454 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4455 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4457 level = btrfs_header_level(buf);
4458 if (btrfs_header_generation(buf) <=
4459 btrfs_root_last_snapshot(&root->root_item))
4462 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4463 rc->create_reloc_tree) {
4464 WARN_ON(!first_cow && level == 0);
4466 node = rc->backref_cache.path[level];
4467 BUG_ON(node->bytenr != buf->start &&
4468 node->new_bytenr != buf->start);
4470 drop_node_buffer(node);
4471 extent_buffer_get(cow);
4473 node->new_bytenr = cow->start;
4475 if (!node->pending) {
4476 list_move_tail(&node->list,
4477 &rc->backref_cache.pending[level]);
4482 __mark_block_processed(rc, node);
4484 if (first_cow && level > 0)
4485 rc->nodes_relocated += buf->len;
4488 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) {
4489 ret = replace_file_extents(trans, rc, root, cow);
4495 * called before creating snapshot. it calculates metadata reservation
4496 * requried for relocating tree blocks in the snapshot
4498 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4499 struct btrfs_pending_snapshot *pending,
4500 u64 *bytes_to_reserve)
4502 struct btrfs_root *root;
4503 struct reloc_control *rc;
4505 root = pending->root;
4506 if (!root->reloc_root)
4509 rc = root->fs_info->reloc_ctl;
4510 if (!rc->merge_reloc_tree)
4513 root = root->reloc_root;
4514 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4516 * relocation is in the stage of merging trees. the space
4517 * used by merging a reloc tree is twice the size of
4518 * relocated tree nodes in the worst case. half for cowing
4519 * the reloc tree, half for cowing the fs tree. the space
4520 * used by cowing the reloc tree will be freed after the
4521 * tree is dropped. if we create snapshot, cowing the fs
4522 * tree may use more space than it frees. so we need
4523 * reserve extra space.
4525 *bytes_to_reserve += rc->nodes_relocated;
4529 * called after snapshot is created. migrate block reservation
4530 * and create reloc root for the newly created snapshot
4532 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4533 struct btrfs_pending_snapshot *pending)
4535 struct btrfs_root *root = pending->root;
4536 struct btrfs_root *reloc_root;
4537 struct btrfs_root *new_root;
4538 struct reloc_control *rc;
4541 if (!root->reloc_root)
4544 rc = root->fs_info->reloc_ctl;
4545 rc->merging_rsv_size += rc->nodes_relocated;
4547 if (rc->merge_reloc_tree) {
4548 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4550 rc->nodes_relocated);
4555 new_root = pending->snap;
4556 reloc_root = create_reloc_root(trans, root->reloc_root,
4557 new_root->root_key.objectid);
4558 if (IS_ERR(reloc_root))
4559 return PTR_ERR(reloc_root);
4561 ret = __add_reloc_root(reloc_root);
4563 new_root->reloc_root = reloc_root;
4565 if (rc->create_reloc_tree)
4566 ret = clone_backref_node(trans, rc, root, reloc_root);