1 // SPDX-License-Identifier: GPL-2.0
3 * Copyright (C) 2009 Oracle. All rights reserved.
6 #include <linux/sched.h>
7 #include <linux/pagemap.h>
8 #include <linux/writeback.h>
9 #include <linux/blkdev.h>
10 #include <linux/rbtree.h>
11 #include <linux/slab.h>
14 #include "transaction.h"
17 #include "btrfs_inode.h"
18 #include "async-thread.h"
19 #include "free-space-cache.h"
20 #include "inode-map.h"
22 #include "print-tree.h"
25 * backref_node, mapping_node and tree_block start with this
28 struct rb_node rb_node;
33 * present a tree block in the backref cache
36 struct rb_node rb_node;
40 /* objectid of tree block owner, can be not uptodate */
42 /* link to pending, changed or detached list */
43 struct list_head list;
44 /* list of upper level blocks reference this block */
45 struct list_head upper;
46 /* list of child blocks in the cache */
47 struct list_head lower;
48 /* NULL if this node is not tree root */
49 struct btrfs_root *root;
50 /* extent buffer got by COW the block */
51 struct extent_buffer *eb;
52 /* level of tree block */
54 /* is the block in non-reference counted tree */
55 unsigned int cowonly:1;
56 /* 1 if no child node in the cache */
57 unsigned int lowest:1;
58 /* is the extent buffer locked */
59 unsigned int locked:1;
60 /* has the block been processed */
61 unsigned int processed:1;
62 /* have backrefs of this block been checked */
63 unsigned int checked:1;
65 * 1 if corresponding block has been cowed but some upper
66 * level block pointers may not point to the new location
68 unsigned int pending:1;
70 * 1 if the backref node isn't connected to any other
73 unsigned int detached:1;
77 * present a block pointer in the backref cache
80 struct list_head list[2];
81 struct backref_node *node[2];
86 #define RELOCATION_RESERVED_NODES 256
88 struct backref_cache {
89 /* red black tree of all backref nodes in the cache */
90 struct rb_root rb_root;
91 /* for passing backref nodes to btrfs_reloc_cow_block */
92 struct backref_node *path[BTRFS_MAX_LEVEL];
94 * list of blocks that have been cowed but some block
95 * pointers in upper level blocks may not reflect the
98 struct list_head pending[BTRFS_MAX_LEVEL];
99 /* list of backref nodes with no child node */
100 struct list_head leaves;
101 /* list of blocks that have been cowed in current transaction */
102 struct list_head changed;
103 /* list of detached backref node. */
104 struct list_head detached;
113 * map address of tree root to tree
115 struct mapping_node {
116 struct rb_node rb_node;
121 struct mapping_tree {
122 struct rb_root rb_root;
127 * present a tree block to process
130 struct rb_node rb_node;
132 struct btrfs_key key;
133 unsigned int level:8;
134 unsigned int key_ready:1;
137 #define MAX_EXTENTS 128
139 struct file_extent_cluster {
142 u64 boundary[MAX_EXTENTS];
146 struct reloc_control {
147 /* block group to relocate */
148 struct btrfs_block_group_cache *block_group;
150 struct btrfs_root *extent_root;
151 /* inode for moving data */
152 struct inode *data_inode;
154 struct btrfs_block_rsv *block_rsv;
156 struct backref_cache backref_cache;
158 struct file_extent_cluster cluster;
159 /* tree blocks have been processed */
160 struct extent_io_tree processed_blocks;
161 /* map start of tree root to corresponding reloc tree */
162 struct mapping_tree reloc_root_tree;
163 /* list of reloc trees */
164 struct list_head reloc_roots;
165 /* size of metadata reservation for merging reloc trees */
166 u64 merging_rsv_size;
167 /* size of relocated tree nodes */
169 /* reserved size for block group relocation*/
175 unsigned int stage:8;
176 unsigned int create_reloc_tree:1;
177 unsigned int merge_reloc_tree:1;
178 unsigned int found_file_extent:1;
181 /* stages of data relocation */
182 #define MOVE_DATA_EXTENTS 0
183 #define UPDATE_DATA_PTRS 1
185 static void remove_backref_node(struct backref_cache *cache,
186 struct backref_node *node);
187 static void __mark_block_processed(struct reloc_control *rc,
188 struct backref_node *node);
190 static void mapping_tree_init(struct mapping_tree *tree)
192 tree->rb_root = RB_ROOT;
193 spin_lock_init(&tree->lock);
196 static void backref_cache_init(struct backref_cache *cache)
199 cache->rb_root = RB_ROOT;
200 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
201 INIT_LIST_HEAD(&cache->pending[i]);
202 INIT_LIST_HEAD(&cache->changed);
203 INIT_LIST_HEAD(&cache->detached);
204 INIT_LIST_HEAD(&cache->leaves);
207 static void backref_cache_cleanup(struct backref_cache *cache)
209 struct backref_node *node;
212 while (!list_empty(&cache->detached)) {
213 node = list_entry(cache->detached.next,
214 struct backref_node, list);
215 remove_backref_node(cache, node);
218 while (!list_empty(&cache->leaves)) {
219 node = list_entry(cache->leaves.next,
220 struct backref_node, lower);
221 remove_backref_node(cache, node);
224 cache->last_trans = 0;
226 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
227 ASSERT(list_empty(&cache->pending[i]));
228 ASSERT(list_empty(&cache->changed));
229 ASSERT(list_empty(&cache->detached));
230 ASSERT(RB_EMPTY_ROOT(&cache->rb_root));
231 ASSERT(!cache->nr_nodes);
232 ASSERT(!cache->nr_edges);
235 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
237 struct backref_node *node;
239 node = kzalloc(sizeof(*node), GFP_NOFS);
241 INIT_LIST_HEAD(&node->list);
242 INIT_LIST_HEAD(&node->upper);
243 INIT_LIST_HEAD(&node->lower);
244 RB_CLEAR_NODE(&node->rb_node);
250 static void free_backref_node(struct backref_cache *cache,
251 struct backref_node *node)
259 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
261 struct backref_edge *edge;
263 edge = kzalloc(sizeof(*edge), GFP_NOFS);
269 static void free_backref_edge(struct backref_cache *cache,
270 struct backref_edge *edge)
278 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
279 struct rb_node *node)
281 struct rb_node **p = &root->rb_node;
282 struct rb_node *parent = NULL;
283 struct tree_entry *entry;
287 entry = rb_entry(parent, struct tree_entry, rb_node);
289 if (bytenr < entry->bytenr)
291 else if (bytenr > entry->bytenr)
297 rb_link_node(node, parent, p);
298 rb_insert_color(node, root);
302 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
304 struct rb_node *n = root->rb_node;
305 struct tree_entry *entry;
308 entry = rb_entry(n, struct tree_entry, rb_node);
310 if (bytenr < entry->bytenr)
312 else if (bytenr > entry->bytenr)
320 static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr)
323 struct btrfs_fs_info *fs_info = NULL;
324 struct backref_node *bnode = rb_entry(rb_node, struct backref_node,
327 fs_info = bnode->root->fs_info;
328 btrfs_panic(fs_info, errno,
329 "Inconsistency in backref cache found at offset %llu",
334 * walk up backref nodes until reach node presents tree root
336 static struct backref_node *walk_up_backref(struct backref_node *node,
337 struct backref_edge *edges[],
340 struct backref_edge *edge;
343 while (!list_empty(&node->upper)) {
344 edge = list_entry(node->upper.next,
345 struct backref_edge, list[LOWER]);
347 node = edge->node[UPPER];
349 BUG_ON(node->detached);
355 * walk down backref nodes to find start of next reference path
357 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
360 struct backref_edge *edge;
361 struct backref_node *lower;
365 edge = edges[idx - 1];
366 lower = edge->node[LOWER];
367 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
371 edge = list_entry(edge->list[LOWER].next,
372 struct backref_edge, list[LOWER]);
373 edges[idx - 1] = edge;
375 return edge->node[UPPER];
381 static void unlock_node_buffer(struct backref_node *node)
384 btrfs_tree_unlock(node->eb);
389 static void drop_node_buffer(struct backref_node *node)
392 unlock_node_buffer(node);
393 free_extent_buffer(node->eb);
398 static void drop_backref_node(struct backref_cache *tree,
399 struct backref_node *node)
401 BUG_ON(!list_empty(&node->upper));
403 drop_node_buffer(node);
404 list_del(&node->list);
405 list_del(&node->lower);
406 if (!RB_EMPTY_NODE(&node->rb_node))
407 rb_erase(&node->rb_node, &tree->rb_root);
408 free_backref_node(tree, node);
412 * remove a backref node from the backref cache
414 static void remove_backref_node(struct backref_cache *cache,
415 struct backref_node *node)
417 struct backref_node *upper;
418 struct backref_edge *edge;
423 BUG_ON(!node->lowest && !node->detached);
424 while (!list_empty(&node->upper)) {
425 edge = list_entry(node->upper.next, struct backref_edge,
427 upper = edge->node[UPPER];
428 list_del(&edge->list[LOWER]);
429 list_del(&edge->list[UPPER]);
430 free_backref_edge(cache, edge);
432 if (RB_EMPTY_NODE(&upper->rb_node)) {
433 BUG_ON(!list_empty(&node->upper));
434 drop_backref_node(cache, node);
440 * add the node to leaf node list if no other
441 * child block cached.
443 if (list_empty(&upper->lower)) {
444 list_add_tail(&upper->lower, &cache->leaves);
449 drop_backref_node(cache, node);
452 static void update_backref_node(struct backref_cache *cache,
453 struct backref_node *node, u64 bytenr)
455 struct rb_node *rb_node;
456 rb_erase(&node->rb_node, &cache->rb_root);
457 node->bytenr = bytenr;
458 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
460 backref_tree_panic(rb_node, -EEXIST, bytenr);
464 * update backref cache after a transaction commit
466 static int update_backref_cache(struct btrfs_trans_handle *trans,
467 struct backref_cache *cache)
469 struct backref_node *node;
472 if (cache->last_trans == 0) {
473 cache->last_trans = trans->transid;
477 if (cache->last_trans == trans->transid)
481 * detached nodes are used to avoid unnecessary backref
482 * lookup. transaction commit changes the extent tree.
483 * so the detached nodes are no longer useful.
485 while (!list_empty(&cache->detached)) {
486 node = list_entry(cache->detached.next,
487 struct backref_node, list);
488 remove_backref_node(cache, node);
491 while (!list_empty(&cache->changed)) {
492 node = list_entry(cache->changed.next,
493 struct backref_node, list);
494 list_del_init(&node->list);
495 BUG_ON(node->pending);
496 update_backref_node(cache, node, node->new_bytenr);
500 * some nodes can be left in the pending list if there were
501 * errors during processing the pending nodes.
503 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
504 list_for_each_entry(node, &cache->pending[level], list) {
505 BUG_ON(!node->pending);
506 if (node->bytenr == node->new_bytenr)
508 update_backref_node(cache, node, node->new_bytenr);
512 cache->last_trans = 0;
517 static int should_ignore_root(struct btrfs_root *root)
519 struct btrfs_root *reloc_root;
521 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
524 reloc_root = root->reloc_root;
528 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
529 root->fs_info->running_transaction->transid - 1)
532 * if there is reloc tree and it was created in previous
533 * transaction backref lookup can find the reloc tree,
534 * so backref node for the fs tree root is useless for
540 * find reloc tree by address of tree root
542 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
545 struct rb_node *rb_node;
546 struct mapping_node *node;
547 struct btrfs_root *root = NULL;
549 spin_lock(&rc->reloc_root_tree.lock);
550 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
552 node = rb_entry(rb_node, struct mapping_node, rb_node);
553 root = (struct btrfs_root *)node->data;
555 spin_unlock(&rc->reloc_root_tree.lock);
559 static int is_cowonly_root(u64 root_objectid)
561 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
562 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
563 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
564 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
565 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
566 root_objectid == BTRFS_CSUM_TREE_OBJECTID ||
567 root_objectid == BTRFS_UUID_TREE_OBJECTID ||
568 root_objectid == BTRFS_QUOTA_TREE_OBJECTID ||
569 root_objectid == BTRFS_FREE_SPACE_TREE_OBJECTID)
574 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
577 struct btrfs_key key;
579 key.objectid = root_objectid;
580 key.type = BTRFS_ROOT_ITEM_KEY;
581 if (is_cowonly_root(root_objectid))
584 key.offset = (u64)-1;
586 return btrfs_get_fs_root(fs_info, &key, false);
589 static noinline_for_stack
590 int find_inline_backref(struct extent_buffer *leaf, int slot,
591 unsigned long *ptr, unsigned long *end)
593 struct btrfs_key key;
594 struct btrfs_extent_item *ei;
595 struct btrfs_tree_block_info *bi;
598 btrfs_item_key_to_cpu(leaf, &key, slot);
600 item_size = btrfs_item_size_nr(leaf, slot);
601 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
602 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
603 BTRFS_EXTENT_FLAG_TREE_BLOCK));
605 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
606 item_size <= sizeof(*ei) + sizeof(*bi)) {
607 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
610 if (key.type == BTRFS_METADATA_ITEM_KEY &&
611 item_size <= sizeof(*ei)) {
612 WARN_ON(item_size < sizeof(*ei));
616 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
617 bi = (struct btrfs_tree_block_info *)(ei + 1);
618 *ptr = (unsigned long)(bi + 1);
620 *ptr = (unsigned long)(ei + 1);
622 *end = (unsigned long)ei + item_size;
627 * build backref tree for a given tree block. root of the backref tree
628 * corresponds the tree block, leaves of the backref tree correspond
629 * roots of b-trees that reference the tree block.
631 * the basic idea of this function is check backrefs of a given block
632 * to find upper level blocks that reference the block, and then check
633 * backrefs of these upper level blocks recursively. the recursion stop
634 * when tree root is reached or backrefs for the block is cached.
636 * NOTE: if we find backrefs for a block are cached, we know backrefs
637 * for all upper level blocks that directly/indirectly reference the
638 * block are also cached.
640 static noinline_for_stack
641 struct backref_node *build_backref_tree(struct reloc_control *rc,
642 struct btrfs_key *node_key,
643 int level, u64 bytenr)
645 struct backref_cache *cache = &rc->backref_cache;
646 struct btrfs_path *path1;
647 struct btrfs_path *path2;
648 struct extent_buffer *eb;
649 struct btrfs_root *root;
650 struct backref_node *cur;
651 struct backref_node *upper;
652 struct backref_node *lower;
653 struct backref_node *node = NULL;
654 struct backref_node *exist = NULL;
655 struct backref_edge *edge;
656 struct rb_node *rb_node;
657 struct btrfs_key key;
665 bool need_check = true;
667 path1 = btrfs_alloc_path();
668 path2 = btrfs_alloc_path();
669 if (!path1 || !path2) {
673 path1->reada = READA_FORWARD;
674 path2->reada = READA_FORWARD;
676 node = alloc_backref_node(cache);
682 node->bytenr = bytenr;
689 key.objectid = cur->bytenr;
690 key.type = BTRFS_METADATA_ITEM_KEY;
691 key.offset = (u64)-1;
693 path1->search_commit_root = 1;
694 path1->skip_locking = 1;
695 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
702 ASSERT(path1->slots[0]);
706 WARN_ON(cur->checked);
707 if (!list_empty(&cur->upper)) {
709 * the backref was added previously when processing
710 * backref of type BTRFS_TREE_BLOCK_REF_KEY
712 ASSERT(list_is_singular(&cur->upper));
713 edge = list_entry(cur->upper.next, struct backref_edge,
715 ASSERT(list_empty(&edge->list[UPPER]));
716 exist = edge->node[UPPER];
718 * add the upper level block to pending list if we need
722 list_add_tail(&edge->list[UPPER], &list);
729 eb = path1->nodes[0];
732 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
733 ret = btrfs_next_leaf(rc->extent_root, path1);
740 eb = path1->nodes[0];
743 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
744 if (key.objectid != cur->bytenr) {
749 if (key.type == BTRFS_EXTENT_ITEM_KEY ||
750 key.type == BTRFS_METADATA_ITEM_KEY) {
751 ret = find_inline_backref(eb, path1->slots[0],
759 /* update key for inline back ref */
760 struct btrfs_extent_inline_ref *iref;
762 iref = (struct btrfs_extent_inline_ref *)ptr;
763 type = btrfs_get_extent_inline_ref_type(eb, iref,
764 BTRFS_REF_TYPE_BLOCK);
765 if (type == BTRFS_REF_TYPE_INVALID) {
770 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
772 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
773 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
777 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
778 exist->owner == key.offset) ||
779 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
780 exist->bytenr == key.offset))) {
785 ASSERT(key.type != BTRFS_EXTENT_REF_V0_KEY);
786 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
787 if (key.objectid == key.offset) {
789 * only root blocks of reloc trees use
790 * backref of this type.
792 root = find_reloc_root(rc, cur->bytenr);
798 edge = alloc_backref_edge(cache);
803 rb_node = tree_search(&cache->rb_root, key.offset);
805 upper = alloc_backref_node(cache);
807 free_backref_edge(cache, edge);
811 upper->bytenr = key.offset;
812 upper->level = cur->level + 1;
814 * backrefs for the upper level block isn't
815 * cached, add the block to pending list
817 list_add_tail(&edge->list[UPPER], &list);
819 upper = rb_entry(rb_node, struct backref_node,
821 ASSERT(upper->checked);
822 INIT_LIST_HEAD(&edge->list[UPPER]);
824 list_add_tail(&edge->list[LOWER], &cur->upper);
825 edge->node[LOWER] = cur;
826 edge->node[UPPER] = upper;
829 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
833 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
834 root = read_fs_root(rc->extent_root->fs_info, key.offset);
840 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
843 if (btrfs_root_level(&root->root_item) == cur->level) {
845 ASSERT(btrfs_root_bytenr(&root->root_item) ==
847 if (should_ignore_root(root))
848 list_add(&cur->list, &useless);
854 level = cur->level + 1;
857 * searching the tree to find upper level blocks
858 * reference the block.
860 path2->search_commit_root = 1;
861 path2->skip_locking = 1;
862 path2->lowest_level = level;
863 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
864 path2->lowest_level = 0;
869 if (ret > 0 && path2->slots[level] > 0)
870 path2->slots[level]--;
872 eb = path2->nodes[level];
873 if (btrfs_node_blockptr(eb, path2->slots[level]) !=
875 btrfs_err(root->fs_info,
876 "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)",
877 cur->bytenr, level - 1, root->objectid,
878 node_key->objectid, node_key->type,
885 for (; level < BTRFS_MAX_LEVEL; level++) {
886 if (!path2->nodes[level]) {
887 ASSERT(btrfs_root_bytenr(&root->root_item) ==
889 if (should_ignore_root(root))
890 list_add(&lower->list, &useless);
896 edge = alloc_backref_edge(cache);
902 eb = path2->nodes[level];
903 rb_node = tree_search(&cache->rb_root, eb->start);
905 upper = alloc_backref_node(cache);
907 free_backref_edge(cache, edge);
911 upper->bytenr = eb->start;
912 upper->owner = btrfs_header_owner(eb);
913 upper->level = lower->level + 1;
914 if (!test_bit(BTRFS_ROOT_REF_COWS,
919 * if we know the block isn't shared
920 * we can void checking its backrefs.
922 if (btrfs_block_can_be_shared(root, eb))
928 * add the block to pending list if we
929 * need check its backrefs, we only do this once
930 * while walking up a tree as we will catch
931 * anything else later on.
933 if (!upper->checked && need_check) {
935 list_add_tail(&edge->list[UPPER],
940 INIT_LIST_HEAD(&edge->list[UPPER]);
943 upper = rb_entry(rb_node, struct backref_node,
945 ASSERT(upper->checked);
946 INIT_LIST_HEAD(&edge->list[UPPER]);
948 upper->owner = btrfs_header_owner(eb);
950 list_add_tail(&edge->list[LOWER], &lower->upper);
951 edge->node[LOWER] = lower;
952 edge->node[UPPER] = upper;
959 btrfs_release_path(path2);
962 ptr += btrfs_extent_inline_ref_size(key.type);
972 btrfs_release_path(path1);
977 /* the pending list isn't empty, take the first block to process */
978 if (!list_empty(&list)) {
979 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
980 list_del_init(&edge->list[UPPER]);
981 cur = edge->node[UPPER];
986 * everything goes well, connect backref nodes and insert backref nodes
989 ASSERT(node->checked);
990 cowonly = node->cowonly;
992 rb_node = tree_insert(&cache->rb_root, node->bytenr,
995 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
996 list_add_tail(&node->lower, &cache->leaves);
999 list_for_each_entry(edge, &node->upper, list[LOWER])
1000 list_add_tail(&edge->list[UPPER], &list);
1002 while (!list_empty(&list)) {
1003 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1004 list_del_init(&edge->list[UPPER]);
1005 upper = edge->node[UPPER];
1006 if (upper->detached) {
1007 list_del(&edge->list[LOWER]);
1008 lower = edge->node[LOWER];
1009 free_backref_edge(cache, edge);
1010 if (list_empty(&lower->upper))
1011 list_add(&lower->list, &useless);
1015 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1016 if (upper->lowest) {
1017 list_del_init(&upper->lower);
1021 list_add_tail(&edge->list[UPPER], &upper->lower);
1025 if (!upper->checked) {
1027 * Still want to blow up for developers since this is a
1034 if (cowonly != upper->cowonly) {
1041 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1044 backref_tree_panic(rb_node, -EEXIST,
1048 list_add_tail(&edge->list[UPPER], &upper->lower);
1050 list_for_each_entry(edge, &upper->upper, list[LOWER])
1051 list_add_tail(&edge->list[UPPER], &list);
1054 * process useless backref nodes. backref nodes for tree leaves
1055 * are deleted from the cache. backref nodes for upper level
1056 * tree blocks are left in the cache to avoid unnecessary backref
1059 while (!list_empty(&useless)) {
1060 upper = list_entry(useless.next, struct backref_node, list);
1061 list_del_init(&upper->list);
1062 ASSERT(list_empty(&upper->upper));
1065 if (upper->lowest) {
1066 list_del_init(&upper->lower);
1069 while (!list_empty(&upper->lower)) {
1070 edge = list_entry(upper->lower.next,
1071 struct backref_edge, list[UPPER]);
1072 list_del(&edge->list[UPPER]);
1073 list_del(&edge->list[LOWER]);
1074 lower = edge->node[LOWER];
1075 free_backref_edge(cache, edge);
1077 if (list_empty(&lower->upper))
1078 list_add(&lower->list, &useless);
1080 __mark_block_processed(rc, upper);
1081 if (upper->level > 0) {
1082 list_add(&upper->list, &cache->detached);
1083 upper->detached = 1;
1085 rb_erase(&upper->rb_node, &cache->rb_root);
1086 free_backref_node(cache, upper);
1090 btrfs_free_path(path1);
1091 btrfs_free_path(path2);
1093 while (!list_empty(&useless)) {
1094 lower = list_entry(useless.next,
1095 struct backref_node, list);
1096 list_del_init(&lower->list);
1098 while (!list_empty(&list)) {
1099 edge = list_first_entry(&list, struct backref_edge,
1101 list_del(&edge->list[UPPER]);
1102 list_del(&edge->list[LOWER]);
1103 lower = edge->node[LOWER];
1104 upper = edge->node[UPPER];
1105 free_backref_edge(cache, edge);
1108 * Lower is no longer linked to any upper backref nodes
1109 * and isn't in the cache, we can free it ourselves.
1111 if (list_empty(&lower->upper) &&
1112 RB_EMPTY_NODE(&lower->rb_node))
1113 list_add(&lower->list, &useless);
1115 if (!RB_EMPTY_NODE(&upper->rb_node))
1118 /* Add this guy's upper edges to the list to process */
1119 list_for_each_entry(edge, &upper->upper, list[LOWER])
1120 list_add_tail(&edge->list[UPPER], &list);
1121 if (list_empty(&upper->upper))
1122 list_add(&upper->list, &useless);
1125 while (!list_empty(&useless)) {
1126 lower = list_entry(useless.next,
1127 struct backref_node, list);
1128 list_del_init(&lower->list);
1131 free_backref_node(cache, lower);
1134 free_backref_node(cache, node);
1135 return ERR_PTR(err);
1137 ASSERT(!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 btrfs_fs_info *fs_info = root->fs_info;
1238 struct rb_node *rb_node;
1239 struct mapping_node *node;
1240 struct reloc_control *rc = fs_info->reloc_ctl;
1242 node = kmalloc(sizeof(*node), GFP_NOFS);
1246 node->bytenr = root->node->start;
1249 spin_lock(&rc->reloc_root_tree.lock);
1250 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1251 node->bytenr, &node->rb_node);
1252 spin_unlock(&rc->reloc_root_tree.lock);
1254 btrfs_panic(fs_info, -EEXIST,
1255 "Duplicate root found for start=%llu while inserting into relocation tree",
1259 list_add_tail(&root->root_list, &rc->reloc_roots);
1264 * helper to delete the 'address of tree root -> reloc tree'
1267 static void __del_reloc_root(struct btrfs_root *root)
1269 struct btrfs_fs_info *fs_info = root->fs_info;
1270 struct rb_node *rb_node;
1271 struct mapping_node *node = NULL;
1272 struct reloc_control *rc = fs_info->reloc_ctl;
1274 spin_lock(&rc->reloc_root_tree.lock);
1275 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
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);
1287 spin_lock(&fs_info->trans_lock);
1288 list_del_init(&root->root_list);
1289 spin_unlock(&fs_info->trans_lock);
1294 * helper to update the 'address of tree root -> reloc tree'
1297 static int __update_reloc_root(struct btrfs_root *root, u64 new_bytenr)
1299 struct btrfs_fs_info *fs_info = root->fs_info;
1300 struct rb_node *rb_node;
1301 struct mapping_node *node = NULL;
1302 struct reloc_control *rc = fs_info->reloc_ctl;
1304 spin_lock(&rc->reloc_root_tree.lock);
1305 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1308 node = rb_entry(rb_node, struct mapping_node, rb_node);
1309 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1311 spin_unlock(&rc->reloc_root_tree.lock);
1315 BUG_ON((struct btrfs_root *)node->data != root);
1317 spin_lock(&rc->reloc_root_tree.lock);
1318 node->bytenr = new_bytenr;
1319 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1320 node->bytenr, &node->rb_node);
1321 spin_unlock(&rc->reloc_root_tree.lock);
1323 backref_tree_panic(rb_node, -EEXIST, node->bytenr);
1327 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1328 struct btrfs_root *root, u64 objectid)
1330 struct btrfs_fs_info *fs_info = root->fs_info;
1331 struct btrfs_root *reloc_root;
1332 struct extent_buffer *eb;
1333 struct btrfs_root_item *root_item;
1334 struct btrfs_key root_key;
1337 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1340 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1341 root_key.type = BTRFS_ROOT_ITEM_KEY;
1342 root_key.offset = objectid;
1344 if (root->root_key.objectid == objectid) {
1345 u64 commit_root_gen;
1347 /* called by btrfs_init_reloc_root */
1348 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1349 BTRFS_TREE_RELOC_OBJECTID);
1352 * Set the last_snapshot field to the generation of the commit
1353 * root - like this ctree.c:btrfs_block_can_be_shared() behaves
1354 * correctly (returns true) when the relocation root is created
1355 * either inside the critical section of a transaction commit
1356 * (through transaction.c:qgroup_account_snapshot()) and when
1357 * it's created before the transaction commit is started.
1359 commit_root_gen = btrfs_header_generation(root->commit_root);
1360 btrfs_set_root_last_snapshot(&root->root_item, commit_root_gen);
1363 * called by btrfs_reloc_post_snapshot_hook.
1364 * the source tree is a reloc tree, all tree blocks
1365 * modified after it was created have RELOC flag
1366 * set in their headers. so it's OK to not update
1367 * the 'last_snapshot'.
1369 ret = btrfs_copy_root(trans, root, root->node, &eb,
1370 BTRFS_TREE_RELOC_OBJECTID);
1374 memcpy(root_item, &root->root_item, sizeof(*root_item));
1375 btrfs_set_root_bytenr(root_item, eb->start);
1376 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1377 btrfs_set_root_generation(root_item, trans->transid);
1379 if (root->root_key.objectid == objectid) {
1380 btrfs_set_root_refs(root_item, 0);
1381 memset(&root_item->drop_progress, 0,
1382 sizeof(struct btrfs_disk_key));
1383 root_item->drop_level = 0;
1386 btrfs_tree_unlock(eb);
1387 free_extent_buffer(eb);
1389 ret = btrfs_insert_root(trans, fs_info->tree_root,
1390 &root_key, root_item);
1394 reloc_root = btrfs_read_fs_root(fs_info->tree_root, &root_key);
1395 BUG_ON(IS_ERR(reloc_root));
1396 reloc_root->last_trans = trans->transid;
1401 * create reloc tree for a given fs tree. reloc tree is just a
1402 * snapshot of the fs tree with special root objectid.
1404 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1405 struct btrfs_root *root)
1407 struct btrfs_fs_info *fs_info = root->fs_info;
1408 struct btrfs_root *reloc_root;
1409 struct reloc_control *rc = fs_info->reloc_ctl;
1410 struct btrfs_block_rsv *rsv;
1414 if (root->reloc_root) {
1415 reloc_root = root->reloc_root;
1416 reloc_root->last_trans = trans->transid;
1420 if (!rc || !rc->create_reloc_tree ||
1421 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1424 if (!trans->reloc_reserved) {
1425 rsv = trans->block_rsv;
1426 trans->block_rsv = rc->block_rsv;
1429 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1431 trans->block_rsv = rsv;
1433 ret = __add_reloc_root(reloc_root);
1435 root->reloc_root = reloc_root;
1440 * update root item of reloc tree
1442 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1443 struct btrfs_root *root)
1445 struct btrfs_fs_info *fs_info = root->fs_info;
1446 struct btrfs_root *reloc_root;
1447 struct btrfs_root_item *root_item;
1450 if (!root->reloc_root)
1453 reloc_root = root->reloc_root;
1454 root_item = &reloc_root->root_item;
1456 if (fs_info->reloc_ctl->merge_reloc_tree &&
1457 btrfs_root_refs(root_item) == 0) {
1458 root->reloc_root = NULL;
1459 __del_reloc_root(reloc_root);
1462 if (reloc_root->commit_root != reloc_root->node) {
1463 btrfs_set_root_node(root_item, reloc_root->node);
1464 free_extent_buffer(reloc_root->commit_root);
1465 reloc_root->commit_root = btrfs_root_node(reloc_root);
1468 ret = btrfs_update_root(trans, fs_info->tree_root,
1469 &reloc_root->root_key, root_item);
1477 * helper to find first cached inode with inode number >= objectid
1480 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1482 struct rb_node *node;
1483 struct rb_node *prev;
1484 struct btrfs_inode *entry;
1485 struct inode *inode;
1487 spin_lock(&root->inode_lock);
1489 node = root->inode_tree.rb_node;
1493 entry = rb_entry(node, struct btrfs_inode, rb_node);
1495 if (objectid < btrfs_ino(entry))
1496 node = node->rb_left;
1497 else if (objectid > btrfs_ino(entry))
1498 node = node->rb_right;
1504 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1505 if (objectid <= btrfs_ino(entry)) {
1509 prev = rb_next(prev);
1513 entry = rb_entry(node, struct btrfs_inode, rb_node);
1514 inode = igrab(&entry->vfs_inode);
1516 spin_unlock(&root->inode_lock);
1520 objectid = btrfs_ino(entry) + 1;
1521 if (cond_resched_lock(&root->inode_lock))
1524 node = rb_next(node);
1526 spin_unlock(&root->inode_lock);
1530 static int in_block_group(u64 bytenr,
1531 struct btrfs_block_group_cache *block_group)
1533 if (bytenr >= block_group->key.objectid &&
1534 bytenr < block_group->key.objectid + block_group->key.offset)
1540 * get new location of data
1542 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1543 u64 bytenr, u64 num_bytes)
1545 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1546 struct btrfs_path *path;
1547 struct btrfs_file_extent_item *fi;
1548 struct extent_buffer *leaf;
1551 path = btrfs_alloc_path();
1555 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1556 ret = btrfs_lookup_file_extent(NULL, root, path,
1557 btrfs_ino(BTRFS_I(reloc_inode)), bytenr, 0);
1565 leaf = path->nodes[0];
1566 fi = btrfs_item_ptr(leaf, path->slots[0],
1567 struct btrfs_file_extent_item);
1569 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1570 btrfs_file_extent_compression(leaf, fi) ||
1571 btrfs_file_extent_encryption(leaf, fi) ||
1572 btrfs_file_extent_other_encoding(leaf, fi));
1574 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1579 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1582 btrfs_free_path(path);
1587 * update file extent items in the tree leaf to point to
1588 * the new locations.
1590 static noinline_for_stack
1591 int replace_file_extents(struct btrfs_trans_handle *trans,
1592 struct reloc_control *rc,
1593 struct btrfs_root *root,
1594 struct extent_buffer *leaf)
1596 struct btrfs_fs_info *fs_info = root->fs_info;
1597 struct btrfs_key key;
1598 struct btrfs_file_extent_item *fi;
1599 struct inode *inode = NULL;
1611 if (rc->stage != UPDATE_DATA_PTRS)
1614 /* reloc trees always use full backref */
1615 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1616 parent = leaf->start;
1620 nritems = btrfs_header_nritems(leaf);
1621 for (i = 0; i < nritems; i++) {
1623 btrfs_item_key_to_cpu(leaf, &key, i);
1624 if (key.type != BTRFS_EXTENT_DATA_KEY)
1626 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1627 if (btrfs_file_extent_type(leaf, fi) ==
1628 BTRFS_FILE_EXTENT_INLINE)
1630 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1631 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1634 if (!in_block_group(bytenr, rc->block_group))
1638 * if we are modifying block in fs tree, wait for readpage
1639 * to complete and drop the extent cache
1641 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1643 inode = find_next_inode(root, key.objectid);
1645 } else if (inode && btrfs_ino(BTRFS_I(inode)) < key.objectid) {
1646 btrfs_add_delayed_iput(inode);
1647 inode = find_next_inode(root, key.objectid);
1649 if (inode && btrfs_ino(BTRFS_I(inode)) == key.objectid) {
1651 btrfs_file_extent_num_bytes(leaf, fi);
1652 WARN_ON(!IS_ALIGNED(key.offset,
1653 fs_info->sectorsize));
1654 WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize));
1656 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1661 btrfs_drop_extent_cache(BTRFS_I(inode),
1662 key.offset, end, 1);
1663 unlock_extent(&BTRFS_I(inode)->io_tree,
1668 ret = get_new_location(rc->data_inode, &new_bytenr,
1672 * Don't have to abort since we've not changed anything
1673 * in the file extent yet.
1678 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1681 key.offset -= btrfs_file_extent_offset(leaf, fi);
1682 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1684 btrfs_header_owner(leaf),
1685 key.objectid, key.offset);
1687 btrfs_abort_transaction(trans, ret);
1691 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1692 parent, btrfs_header_owner(leaf),
1693 key.objectid, key.offset);
1695 btrfs_abort_transaction(trans, ret);
1700 btrfs_mark_buffer_dirty(leaf);
1702 btrfs_add_delayed_iput(inode);
1706 static noinline_for_stack
1707 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1708 struct btrfs_path *path, int level)
1710 struct btrfs_disk_key key1;
1711 struct btrfs_disk_key key2;
1712 btrfs_node_key(eb, &key1, slot);
1713 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1714 return memcmp(&key1, &key2, sizeof(key1));
1718 * try to replace tree blocks in fs tree with the new blocks
1719 * in reloc tree. tree blocks haven't been modified since the
1720 * reloc tree was create can be replaced.
1722 * if a block was replaced, level of the block + 1 is returned.
1723 * if no block got replaced, 0 is returned. if there are other
1724 * errors, a negative error number is returned.
1726 static noinline_for_stack
1727 int replace_path(struct btrfs_trans_handle *trans,
1728 struct btrfs_root *dest, struct btrfs_root *src,
1729 struct btrfs_path *path, struct btrfs_key *next_key,
1730 int lowest_level, int max_level)
1732 struct btrfs_fs_info *fs_info = dest->fs_info;
1733 struct extent_buffer *eb;
1734 struct extent_buffer *parent;
1735 struct btrfs_key key;
1747 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1748 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1750 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1752 slot = path->slots[lowest_level];
1753 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1755 eb = btrfs_lock_root_node(dest);
1756 btrfs_set_lock_blocking(eb);
1757 level = btrfs_header_level(eb);
1759 if (level < lowest_level) {
1760 btrfs_tree_unlock(eb);
1761 free_extent_buffer(eb);
1766 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1769 btrfs_set_lock_blocking(eb);
1772 next_key->objectid = (u64)-1;
1773 next_key->type = (u8)-1;
1774 next_key->offset = (u64)-1;
1779 struct btrfs_key first_key;
1781 level = btrfs_header_level(parent);
1782 BUG_ON(level < lowest_level);
1784 ret = btrfs_bin_search(parent, &key, level, &slot);
1785 if (ret && slot > 0)
1788 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1789 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1791 old_bytenr = btrfs_node_blockptr(parent, slot);
1792 blocksize = fs_info->nodesize;
1793 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1794 btrfs_node_key_to_cpu(parent, &first_key, slot);
1796 if (level <= max_level) {
1797 eb = path->nodes[level];
1798 new_bytenr = btrfs_node_blockptr(eb,
1799 path->slots[level]);
1800 new_ptr_gen = btrfs_node_ptr_generation(eb,
1801 path->slots[level]);
1807 if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) {
1812 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1813 memcmp_node_keys(parent, slot, path, level)) {
1814 if (level <= lowest_level) {
1819 eb = read_tree_block(fs_info, old_bytenr, old_ptr_gen,
1820 level - 1, &first_key);
1824 } else if (!extent_buffer_uptodate(eb)) {
1826 free_extent_buffer(eb);
1829 btrfs_tree_lock(eb);
1831 ret = btrfs_cow_block(trans, dest, eb, parent,
1835 btrfs_set_lock_blocking(eb);
1837 btrfs_tree_unlock(parent);
1838 free_extent_buffer(parent);
1845 btrfs_tree_unlock(parent);
1846 free_extent_buffer(parent);
1851 btrfs_node_key_to_cpu(path->nodes[level], &key,
1852 path->slots[level]);
1853 btrfs_release_path(path);
1855 path->lowest_level = level;
1856 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1857 path->lowest_level = 0;
1861 * Info qgroup to trace both subtrees.
1863 * We must trace both trees.
1864 * 1) Tree reloc subtree
1865 * If not traced, we will leak data numbers
1867 * If not traced, we will double count old data
1868 * and tree block numbers, if current trans doesn't free
1869 * data reloc tree inode.
1871 ret = btrfs_qgroup_trace_subtree(trans, src, parent,
1872 btrfs_header_generation(parent),
1873 btrfs_header_level(parent));
1876 ret = btrfs_qgroup_trace_subtree(trans, dest,
1878 btrfs_header_generation(path->nodes[level]),
1879 btrfs_header_level(path->nodes[level]));
1884 * swap blocks in fs tree and reloc tree.
1886 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1887 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1888 btrfs_mark_buffer_dirty(parent);
1890 btrfs_set_node_blockptr(path->nodes[level],
1891 path->slots[level], old_bytenr);
1892 btrfs_set_node_ptr_generation(path->nodes[level],
1893 path->slots[level], old_ptr_gen);
1894 btrfs_mark_buffer_dirty(path->nodes[level]);
1896 ret = btrfs_inc_extent_ref(trans, src, old_bytenr,
1897 blocksize, path->nodes[level]->start,
1898 src->root_key.objectid, level - 1, 0);
1900 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr,
1901 blocksize, 0, dest->root_key.objectid,
1905 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1906 path->nodes[level]->start,
1907 src->root_key.objectid, level - 1, 0);
1910 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1911 0, dest->root_key.objectid, level - 1,
1915 btrfs_unlock_up_safe(path, 0);
1920 btrfs_tree_unlock(parent);
1921 free_extent_buffer(parent);
1926 * helper to find next relocated block in reloc tree
1928 static noinline_for_stack
1929 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1932 struct extent_buffer *eb;
1937 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1939 for (i = 0; i < *level; i++) {
1940 free_extent_buffer(path->nodes[i]);
1941 path->nodes[i] = NULL;
1944 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1945 eb = path->nodes[i];
1946 nritems = btrfs_header_nritems(eb);
1947 while (path->slots[i] + 1 < nritems) {
1949 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1956 free_extent_buffer(path->nodes[i]);
1957 path->nodes[i] = NULL;
1963 * walk down reloc tree to find relocated block of lowest level
1965 static noinline_for_stack
1966 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1969 struct btrfs_fs_info *fs_info = root->fs_info;
1970 struct extent_buffer *eb = NULL;
1977 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1979 for (i = *level; i > 0; i--) {
1980 struct btrfs_key first_key;
1982 eb = path->nodes[i];
1983 nritems = btrfs_header_nritems(eb);
1984 while (path->slots[i] < nritems) {
1985 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1986 if (ptr_gen > last_snapshot)
1990 if (path->slots[i] >= nritems) {
2001 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
2002 btrfs_node_key_to_cpu(eb, &first_key, path->slots[i]);
2003 eb = read_tree_block(fs_info, bytenr, ptr_gen, i - 1,
2007 } else if (!extent_buffer_uptodate(eb)) {
2008 free_extent_buffer(eb);
2011 BUG_ON(btrfs_header_level(eb) != i - 1);
2012 path->nodes[i - 1] = eb;
2013 path->slots[i - 1] = 0;
2019 * invalidate extent cache for file extents whose key in range of
2020 * [min_key, max_key)
2022 static int invalidate_extent_cache(struct btrfs_root *root,
2023 struct btrfs_key *min_key,
2024 struct btrfs_key *max_key)
2026 struct btrfs_fs_info *fs_info = root->fs_info;
2027 struct inode *inode = NULL;
2032 objectid = min_key->objectid;
2037 if (objectid > max_key->objectid)
2040 inode = find_next_inode(root, objectid);
2043 ino = btrfs_ino(BTRFS_I(inode));
2045 if (ino > max_key->objectid) {
2051 if (!S_ISREG(inode->i_mode))
2054 if (unlikely(min_key->objectid == ino)) {
2055 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
2057 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
2060 start = min_key->offset;
2061 WARN_ON(!IS_ALIGNED(start, fs_info->sectorsize));
2067 if (unlikely(max_key->objectid == ino)) {
2068 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
2070 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
2073 if (max_key->offset == 0)
2075 end = max_key->offset;
2076 WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize));
2083 /* the lock_extent waits for readpage to complete */
2084 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
2085 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 1);
2086 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
2091 static int find_next_key(struct btrfs_path *path, int level,
2092 struct btrfs_key *key)
2095 while (level < BTRFS_MAX_LEVEL) {
2096 if (!path->nodes[level])
2098 if (path->slots[level] + 1 <
2099 btrfs_header_nritems(path->nodes[level])) {
2100 btrfs_node_key_to_cpu(path->nodes[level], key,
2101 path->slots[level] + 1);
2110 * merge the relocated tree blocks in reloc tree with corresponding
2113 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
2114 struct btrfs_root *root)
2116 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
2117 LIST_HEAD(inode_list);
2118 struct btrfs_key key;
2119 struct btrfs_key next_key;
2120 struct btrfs_trans_handle *trans = NULL;
2121 struct btrfs_root *reloc_root;
2122 struct btrfs_root_item *root_item;
2123 struct btrfs_path *path;
2124 struct extent_buffer *leaf;
2132 path = btrfs_alloc_path();
2135 path->reada = READA_FORWARD;
2137 reloc_root = root->reloc_root;
2138 root_item = &reloc_root->root_item;
2140 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2141 level = btrfs_root_level(root_item);
2142 extent_buffer_get(reloc_root->node);
2143 path->nodes[level] = reloc_root->node;
2144 path->slots[level] = 0;
2146 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2148 level = root_item->drop_level;
2150 path->lowest_level = level;
2151 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2152 path->lowest_level = 0;
2154 btrfs_free_path(path);
2158 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2159 path->slots[level]);
2160 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2162 btrfs_unlock_up_safe(path, 0);
2165 min_reserved = fs_info->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2166 memset(&next_key, 0, sizeof(next_key));
2169 ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
2170 BTRFS_RESERVE_FLUSH_ALL);
2175 trans = btrfs_start_transaction(root, 0);
2176 if (IS_ERR(trans)) {
2177 err = PTR_ERR(trans);
2181 trans->block_rsv = rc->block_rsv;
2186 ret = walk_down_reloc_tree(reloc_root, path, &level);
2194 if (!find_next_key(path, level, &key) &&
2195 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2198 ret = replace_path(trans, root, reloc_root, path,
2199 &next_key, level, max_level);
2208 btrfs_node_key_to_cpu(path->nodes[level], &key,
2209 path->slots[level]);
2213 ret = walk_up_reloc_tree(reloc_root, path, &level);
2219 * save the merging progress in the drop_progress.
2220 * this is OK since root refs == 1 in this case.
2222 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2223 path->slots[level]);
2224 root_item->drop_level = level;
2226 btrfs_end_transaction_throttle(trans);
2229 btrfs_btree_balance_dirty(fs_info);
2231 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2232 invalidate_extent_cache(root, &key, &next_key);
2236 * handle the case only one block in the fs tree need to be
2237 * relocated and the block is tree root.
2239 leaf = btrfs_lock_root_node(root);
2240 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2241 btrfs_tree_unlock(leaf);
2242 free_extent_buffer(leaf);
2246 btrfs_free_path(path);
2249 memset(&root_item->drop_progress, 0,
2250 sizeof(root_item->drop_progress));
2251 root_item->drop_level = 0;
2252 btrfs_set_root_refs(root_item, 0);
2253 btrfs_update_reloc_root(trans, root);
2257 btrfs_end_transaction_throttle(trans);
2259 btrfs_btree_balance_dirty(fs_info);
2261 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2262 invalidate_extent_cache(root, &key, &next_key);
2267 static noinline_for_stack
2268 int prepare_to_merge(struct reloc_control *rc, int err)
2270 struct btrfs_root *root = rc->extent_root;
2271 struct btrfs_fs_info *fs_info = root->fs_info;
2272 struct btrfs_root *reloc_root;
2273 struct btrfs_trans_handle *trans;
2274 LIST_HEAD(reloc_roots);
2278 mutex_lock(&fs_info->reloc_mutex);
2279 rc->merging_rsv_size += fs_info->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2280 rc->merging_rsv_size += rc->nodes_relocated * 2;
2281 mutex_unlock(&fs_info->reloc_mutex);
2285 num_bytes = rc->merging_rsv_size;
2286 ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes,
2287 BTRFS_RESERVE_FLUSH_ALL);
2292 trans = btrfs_join_transaction(rc->extent_root);
2293 if (IS_ERR(trans)) {
2295 btrfs_block_rsv_release(fs_info, rc->block_rsv,
2297 return PTR_ERR(trans);
2301 if (num_bytes != rc->merging_rsv_size) {
2302 btrfs_end_transaction(trans);
2303 btrfs_block_rsv_release(fs_info, rc->block_rsv,
2309 rc->merge_reloc_tree = 1;
2311 while (!list_empty(&rc->reloc_roots)) {
2312 reloc_root = list_entry(rc->reloc_roots.next,
2313 struct btrfs_root, root_list);
2314 list_del_init(&reloc_root->root_list);
2316 root = read_fs_root(fs_info, reloc_root->root_key.offset);
2317 BUG_ON(IS_ERR(root));
2318 BUG_ON(root->reloc_root != reloc_root);
2321 * set reference count to 1, so btrfs_recover_relocation
2322 * knows it should resumes merging
2325 btrfs_set_root_refs(&reloc_root->root_item, 1);
2326 btrfs_update_reloc_root(trans, root);
2328 list_add(&reloc_root->root_list, &reloc_roots);
2331 list_splice(&reloc_roots, &rc->reloc_roots);
2334 btrfs_commit_transaction(trans);
2336 btrfs_end_transaction(trans);
2340 static noinline_for_stack
2341 void free_reloc_roots(struct list_head *list)
2343 struct btrfs_root *reloc_root;
2345 while (!list_empty(list)) {
2346 reloc_root = list_entry(list->next, struct btrfs_root,
2348 __del_reloc_root(reloc_root);
2349 free_extent_buffer(reloc_root->node);
2350 free_extent_buffer(reloc_root->commit_root);
2351 reloc_root->node = NULL;
2352 reloc_root->commit_root = NULL;
2356 static noinline_for_stack
2357 void merge_reloc_roots(struct reloc_control *rc)
2359 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
2360 struct btrfs_root *root;
2361 struct btrfs_root *reloc_root;
2362 LIST_HEAD(reloc_roots);
2366 root = rc->extent_root;
2369 * this serializes us with btrfs_record_root_in_transaction,
2370 * we have to make sure nobody is in the middle of
2371 * adding their roots to the list while we are
2374 mutex_lock(&fs_info->reloc_mutex);
2375 list_splice_init(&rc->reloc_roots, &reloc_roots);
2376 mutex_unlock(&fs_info->reloc_mutex);
2378 while (!list_empty(&reloc_roots)) {
2380 reloc_root = list_entry(reloc_roots.next,
2381 struct btrfs_root, root_list);
2383 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2384 root = read_fs_root(fs_info,
2385 reloc_root->root_key.offset);
2386 BUG_ON(IS_ERR(root));
2387 BUG_ON(root->reloc_root != reloc_root);
2389 ret = merge_reloc_root(rc, root);
2391 if (list_empty(&reloc_root->root_list))
2392 list_add_tail(&reloc_root->root_list,
2397 list_del_init(&reloc_root->root_list);
2400 ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1);
2402 if (list_empty(&reloc_root->root_list))
2403 list_add_tail(&reloc_root->root_list,
2415 btrfs_handle_fs_error(fs_info, ret, NULL);
2416 if (!list_empty(&reloc_roots))
2417 free_reloc_roots(&reloc_roots);
2419 /* new reloc root may be added */
2420 mutex_lock(&fs_info->reloc_mutex);
2421 list_splice_init(&rc->reloc_roots, &reloc_roots);
2422 mutex_unlock(&fs_info->reloc_mutex);
2423 if (!list_empty(&reloc_roots))
2424 free_reloc_roots(&reloc_roots);
2427 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2430 static void free_block_list(struct rb_root *blocks)
2432 struct tree_block *block;
2433 struct rb_node *rb_node;
2434 while ((rb_node = rb_first(blocks))) {
2435 block = rb_entry(rb_node, struct tree_block, rb_node);
2436 rb_erase(rb_node, blocks);
2441 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2442 struct btrfs_root *reloc_root)
2444 struct btrfs_fs_info *fs_info = reloc_root->fs_info;
2445 struct btrfs_root *root;
2447 if (reloc_root->last_trans == trans->transid)
2450 root = read_fs_root(fs_info, reloc_root->root_key.offset);
2451 BUG_ON(IS_ERR(root));
2452 BUG_ON(root->reloc_root != reloc_root);
2454 return btrfs_record_root_in_trans(trans, root);
2457 static noinline_for_stack
2458 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2459 struct reloc_control *rc,
2460 struct backref_node *node,
2461 struct backref_edge *edges[])
2463 struct backref_node *next;
2464 struct btrfs_root *root;
2470 next = walk_up_backref(next, edges, &index);
2473 BUG_ON(!test_bit(BTRFS_ROOT_REF_COWS, &root->state));
2475 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2476 record_reloc_root_in_trans(trans, root);
2480 btrfs_record_root_in_trans(trans, root);
2481 root = root->reloc_root;
2483 if (next->new_bytenr != root->node->start) {
2484 BUG_ON(next->new_bytenr);
2485 BUG_ON(!list_empty(&next->list));
2486 next->new_bytenr = root->node->start;
2488 list_add_tail(&next->list,
2489 &rc->backref_cache.changed);
2490 __mark_block_processed(rc, next);
2496 next = walk_down_backref(edges, &index);
2497 if (!next || next->level <= node->level)
2504 /* setup backref node path for btrfs_reloc_cow_block */
2506 rc->backref_cache.path[next->level] = next;
2509 next = edges[index]->node[UPPER];
2515 * select a tree root for relocation. return NULL if the block
2516 * is reference counted. we should use do_relocation() in this
2517 * case. return a tree root pointer if the block isn't reference
2518 * counted. return -ENOENT if the block is root of reloc tree.
2520 static noinline_for_stack
2521 struct btrfs_root *select_one_root(struct backref_node *node)
2523 struct backref_node *next;
2524 struct btrfs_root *root;
2525 struct btrfs_root *fs_root = NULL;
2526 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2532 next = walk_up_backref(next, edges, &index);
2536 /* no other choice for non-references counted tree */
2537 if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state))
2540 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2546 next = walk_down_backref(edges, &index);
2547 if (!next || next->level <= node->level)
2552 return ERR_PTR(-ENOENT);
2556 static noinline_for_stack
2557 u64 calcu_metadata_size(struct reloc_control *rc,
2558 struct backref_node *node, int reserve)
2560 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
2561 struct backref_node *next = node;
2562 struct backref_edge *edge;
2563 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2567 BUG_ON(reserve && node->processed);
2572 if (next->processed && (reserve || next != node))
2575 num_bytes += fs_info->nodesize;
2577 if (list_empty(&next->upper))
2580 edge = list_entry(next->upper.next,
2581 struct backref_edge, list[LOWER]);
2582 edges[index++] = edge;
2583 next = edge->node[UPPER];
2585 next = walk_down_backref(edges, &index);
2590 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2591 struct reloc_control *rc,
2592 struct backref_node *node)
2594 struct btrfs_root *root = rc->extent_root;
2595 struct btrfs_fs_info *fs_info = root->fs_info;
2600 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2602 trans->block_rsv = rc->block_rsv;
2603 rc->reserved_bytes += num_bytes;
2606 * We are under a transaction here so we can only do limited flushing.
2607 * If we get an enospc just kick back -EAGAIN so we know to drop the
2608 * transaction and try to refill when we can flush all the things.
2610 ret = btrfs_block_rsv_refill(root, rc->block_rsv, num_bytes,
2611 BTRFS_RESERVE_FLUSH_LIMIT);
2613 tmp = fs_info->nodesize * RELOCATION_RESERVED_NODES;
2614 while (tmp <= rc->reserved_bytes)
2617 * only one thread can access block_rsv at this point,
2618 * so we don't need hold lock to protect block_rsv.
2619 * we expand more reservation size here to allow enough
2620 * space for relocation and we will return eailer in
2623 rc->block_rsv->size = tmp + fs_info->nodesize *
2624 RELOCATION_RESERVED_NODES;
2632 * relocate a block tree, and then update pointers in upper level
2633 * blocks that reference the block to point to the new location.
2635 * if called by link_to_upper, the block has already been relocated.
2636 * in that case this function just updates pointers.
2638 static int do_relocation(struct btrfs_trans_handle *trans,
2639 struct reloc_control *rc,
2640 struct backref_node *node,
2641 struct btrfs_key *key,
2642 struct btrfs_path *path, int lowest)
2644 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
2645 struct backref_node *upper;
2646 struct backref_edge *edge;
2647 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2648 struct btrfs_root *root;
2649 struct extent_buffer *eb;
2657 BUG_ON(lowest && node->eb);
2659 path->lowest_level = node->level + 1;
2660 rc->backref_cache.path[node->level] = node;
2661 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2662 struct btrfs_key first_key;
2666 upper = edge->node[UPPER];
2667 root = select_reloc_root(trans, rc, upper, edges);
2670 if (upper->eb && !upper->locked) {
2672 ret = btrfs_bin_search(upper->eb, key,
2673 upper->level, &slot);
2675 bytenr = btrfs_node_blockptr(upper->eb, slot);
2676 if (node->eb->start == bytenr)
2679 drop_node_buffer(upper);
2683 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2690 btrfs_release_path(path);
2695 upper->eb = path->nodes[upper->level];
2696 path->nodes[upper->level] = NULL;
2698 BUG_ON(upper->eb != path->nodes[upper->level]);
2702 path->locks[upper->level] = 0;
2704 slot = path->slots[upper->level];
2705 btrfs_release_path(path);
2707 ret = btrfs_bin_search(upper->eb, key, upper->level,
2712 bytenr = btrfs_node_blockptr(upper->eb, slot);
2714 if (bytenr != node->bytenr) {
2715 btrfs_err(root->fs_info,
2716 "lowest leaf/node mismatch: bytenr %llu node->bytenr %llu slot %d upper %llu",
2717 bytenr, node->bytenr, slot,
2723 if (node->eb->start == bytenr)
2727 blocksize = root->fs_info->nodesize;
2728 generation = btrfs_node_ptr_generation(upper->eb, slot);
2729 btrfs_node_key_to_cpu(upper->eb, &first_key, slot);
2730 eb = read_tree_block(fs_info, bytenr, generation,
2731 upper->level - 1, &first_key);
2735 } else if (!extent_buffer_uptodate(eb)) {
2736 free_extent_buffer(eb);
2740 btrfs_tree_lock(eb);
2741 btrfs_set_lock_blocking(eb);
2744 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2746 btrfs_tree_unlock(eb);
2747 free_extent_buffer(eb);
2752 BUG_ON(node->eb != eb);
2754 btrfs_set_node_blockptr(upper->eb, slot,
2756 btrfs_set_node_ptr_generation(upper->eb, slot,
2758 btrfs_mark_buffer_dirty(upper->eb);
2760 ret = btrfs_inc_extent_ref(trans, root,
2761 node->eb->start, blocksize,
2763 btrfs_header_owner(upper->eb),
2767 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2771 if (!upper->pending)
2772 drop_node_buffer(upper);
2774 unlock_node_buffer(upper);
2779 if (!err && node->pending) {
2780 drop_node_buffer(node);
2781 list_move_tail(&node->list, &rc->backref_cache.changed);
2785 path->lowest_level = 0;
2786 BUG_ON(err == -ENOSPC);
2790 static int link_to_upper(struct btrfs_trans_handle *trans,
2791 struct reloc_control *rc,
2792 struct backref_node *node,
2793 struct btrfs_path *path)
2795 struct btrfs_key key;
2797 btrfs_node_key_to_cpu(node->eb, &key, 0);
2798 return do_relocation(trans, rc, node, &key, path, 0);
2801 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2802 struct reloc_control *rc,
2803 struct btrfs_path *path, int err)
2806 struct backref_cache *cache = &rc->backref_cache;
2807 struct backref_node *node;
2811 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2812 while (!list_empty(&cache->pending[level])) {
2813 node = list_entry(cache->pending[level].next,
2814 struct backref_node, list);
2815 list_move_tail(&node->list, &list);
2816 BUG_ON(!node->pending);
2819 ret = link_to_upper(trans, rc, node, path);
2824 list_splice_init(&list, &cache->pending[level]);
2829 static void mark_block_processed(struct reloc_control *rc,
2830 u64 bytenr, u32 blocksize)
2832 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2836 static void __mark_block_processed(struct reloc_control *rc,
2837 struct backref_node *node)
2840 if (node->level == 0 ||
2841 in_block_group(node->bytenr, rc->block_group)) {
2842 blocksize = rc->extent_root->fs_info->nodesize;
2843 mark_block_processed(rc, node->bytenr, blocksize);
2845 node->processed = 1;
2849 * mark a block and all blocks directly/indirectly reference the block
2852 static void update_processed_blocks(struct reloc_control *rc,
2853 struct backref_node *node)
2855 struct backref_node *next = node;
2856 struct backref_edge *edge;
2857 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2863 if (next->processed)
2866 __mark_block_processed(rc, next);
2868 if (list_empty(&next->upper))
2871 edge = list_entry(next->upper.next,
2872 struct backref_edge, list[LOWER]);
2873 edges[index++] = edge;
2874 next = edge->node[UPPER];
2876 next = walk_down_backref(edges, &index);
2880 static int tree_block_processed(u64 bytenr, struct reloc_control *rc)
2882 u32 blocksize = rc->extent_root->fs_info->nodesize;
2884 if (test_range_bit(&rc->processed_blocks, bytenr,
2885 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2890 static int get_tree_block_key(struct btrfs_fs_info *fs_info,
2891 struct tree_block *block)
2893 struct extent_buffer *eb;
2895 BUG_ON(block->key_ready);
2896 eb = read_tree_block(fs_info, block->bytenr, block->key.offset,
2897 block->level, NULL);
2900 } else if (!extent_buffer_uptodate(eb)) {
2901 free_extent_buffer(eb);
2904 WARN_ON(btrfs_header_level(eb) != block->level);
2905 if (block->level == 0)
2906 btrfs_item_key_to_cpu(eb, &block->key, 0);
2908 btrfs_node_key_to_cpu(eb, &block->key, 0);
2909 free_extent_buffer(eb);
2910 block->key_ready = 1;
2915 * helper function to relocate a tree block
2917 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2918 struct reloc_control *rc,
2919 struct backref_node *node,
2920 struct btrfs_key *key,
2921 struct btrfs_path *path)
2923 struct btrfs_root *root;
2929 BUG_ON(node->processed);
2930 root = select_one_root(node);
2931 if (root == ERR_PTR(-ENOENT)) {
2932 update_processed_blocks(rc, node);
2936 if (!root || test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2937 ret = reserve_metadata_space(trans, rc, node);
2943 if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) {
2944 BUG_ON(node->new_bytenr);
2945 BUG_ON(!list_empty(&node->list));
2946 btrfs_record_root_in_trans(trans, root);
2947 root = root->reloc_root;
2948 node->new_bytenr = root->node->start;
2950 list_add_tail(&node->list, &rc->backref_cache.changed);
2952 path->lowest_level = node->level;
2953 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2954 btrfs_release_path(path);
2959 update_processed_blocks(rc, node);
2961 ret = do_relocation(trans, rc, node, key, path, 1);
2964 if (ret || node->level == 0 || node->cowonly)
2965 remove_backref_node(&rc->backref_cache, node);
2970 * relocate a list of blocks
2972 static noinline_for_stack
2973 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2974 struct reloc_control *rc, struct rb_root *blocks)
2976 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
2977 struct backref_node *node;
2978 struct btrfs_path *path;
2979 struct tree_block *block;
2980 struct rb_node *rb_node;
2984 path = btrfs_alloc_path();
2987 goto out_free_blocks;
2990 rb_node = rb_first(blocks);
2992 block = rb_entry(rb_node, struct tree_block, rb_node);
2993 if (!block->key_ready)
2994 readahead_tree_block(fs_info, block->bytenr);
2995 rb_node = rb_next(rb_node);
2998 rb_node = rb_first(blocks);
3000 block = rb_entry(rb_node, struct tree_block, rb_node);
3001 if (!block->key_ready) {
3002 err = get_tree_block_key(fs_info, block);
3006 rb_node = rb_next(rb_node);
3009 rb_node = rb_first(blocks);
3011 block = rb_entry(rb_node, struct tree_block, rb_node);
3013 node = build_backref_tree(rc, &block->key,
3014 block->level, block->bytenr);
3016 err = PTR_ERR(node);
3020 ret = relocate_tree_block(trans, rc, node, &block->key,
3023 if (ret != -EAGAIN || rb_node == rb_first(blocks))
3027 rb_node = rb_next(rb_node);
3030 err = finish_pending_nodes(trans, rc, path, err);
3033 btrfs_free_path(path);
3035 free_block_list(blocks);
3039 static noinline_for_stack
3040 int prealloc_file_extent_cluster(struct inode *inode,
3041 struct file_extent_cluster *cluster)
3046 u64 offset = BTRFS_I(inode)->index_cnt;
3050 u64 prealloc_start = cluster->start - offset;
3051 u64 prealloc_end = cluster->end - offset;
3053 struct extent_changeset *data_reserved = NULL;
3055 BUG_ON(cluster->start != cluster->boundary[0]);
3058 ret = btrfs_check_data_free_space(inode, &data_reserved, prealloc_start,
3059 prealloc_end + 1 - prealloc_start);
3063 cur_offset = prealloc_start;
3064 while (nr < cluster->nr) {
3065 start = cluster->boundary[nr] - offset;
3066 if (nr + 1 < cluster->nr)
3067 end = cluster->boundary[nr + 1] - 1 - offset;
3069 end = cluster->end - offset;
3071 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3072 num_bytes = end + 1 - start;
3073 if (cur_offset < start)
3074 btrfs_free_reserved_data_space(inode, data_reserved,
3075 cur_offset, start - cur_offset);
3076 ret = btrfs_prealloc_file_range(inode, 0, start,
3077 num_bytes, num_bytes,
3078 end + 1, &alloc_hint);
3079 cur_offset = end + 1;
3080 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3085 if (cur_offset < prealloc_end)
3086 btrfs_free_reserved_data_space(inode, data_reserved,
3087 cur_offset, prealloc_end + 1 - cur_offset);
3089 inode_unlock(inode);
3090 extent_changeset_free(data_reserved);
3094 static noinline_for_stack
3095 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
3098 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3099 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
3100 struct extent_map *em;
3103 em = alloc_extent_map();
3108 em->len = end + 1 - start;
3109 em->block_len = em->len;
3110 em->block_start = block_start;
3111 em->bdev = fs_info->fs_devices->latest_bdev;
3112 set_bit(EXTENT_FLAG_PINNED, &em->flags);
3114 lock_extent(&BTRFS_I(inode)->io_tree, start, end);
3116 write_lock(&em_tree->lock);
3117 ret = add_extent_mapping(em_tree, em, 0);
3118 write_unlock(&em_tree->lock);
3119 if (ret != -EEXIST) {
3120 free_extent_map(em);
3123 btrfs_drop_extent_cache(BTRFS_I(inode), start, end, 0);
3125 unlock_extent(&BTRFS_I(inode)->io_tree, start, end);
3129 static int relocate_file_extent_cluster(struct inode *inode,
3130 struct file_extent_cluster *cluster)
3132 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
3135 u64 offset = BTRFS_I(inode)->index_cnt;
3136 unsigned long index;
3137 unsigned long last_index;
3139 struct file_ra_state *ra;
3140 gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping);
3147 ra = kzalloc(sizeof(*ra), GFP_NOFS);
3151 ret = prealloc_file_extent_cluster(inode, cluster);
3155 file_ra_state_init(ra, inode->i_mapping);
3157 ret = setup_extent_mapping(inode, cluster->start - offset,
3158 cluster->end - offset, cluster->start);
3162 index = (cluster->start - offset) >> PAGE_SHIFT;
3163 last_index = (cluster->end - offset) >> PAGE_SHIFT;
3164 while (index <= last_index) {
3165 ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode),
3170 page = find_lock_page(inode->i_mapping, index);
3172 page_cache_sync_readahead(inode->i_mapping,
3174 last_index + 1 - index);
3175 page = find_or_create_page(inode->i_mapping, index,
3178 btrfs_delalloc_release_metadata(BTRFS_I(inode),
3185 if (PageReadahead(page)) {
3186 page_cache_async_readahead(inode->i_mapping,
3187 ra, NULL, page, index,
3188 last_index + 1 - index);
3191 if (!PageUptodate(page)) {
3192 btrfs_readpage(NULL, page);
3194 if (!PageUptodate(page)) {
3197 btrfs_delalloc_release_metadata(BTRFS_I(inode),
3199 btrfs_delalloc_release_extents(BTRFS_I(inode),
3206 page_start = page_offset(page);
3207 page_end = page_start + PAGE_SIZE - 1;
3209 lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end);
3211 set_page_extent_mapped(page);
3213 if (nr < cluster->nr &&
3214 page_start + offset == cluster->boundary[nr]) {
3215 set_extent_bits(&BTRFS_I(inode)->io_tree,
3216 page_start, page_end,
3221 ret = btrfs_set_extent_delalloc(inode, page_start, page_end, 0,
3226 btrfs_delalloc_release_metadata(BTRFS_I(inode),
3228 btrfs_delalloc_release_extents(BTRFS_I(inode),
3231 clear_extent_bits(&BTRFS_I(inode)->io_tree,
3232 page_start, page_end,
3233 EXTENT_LOCKED | EXTENT_BOUNDARY);
3237 set_page_dirty(page);
3239 unlock_extent(&BTRFS_I(inode)->io_tree,
3240 page_start, page_end);
3245 btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE,
3247 balance_dirty_pages_ratelimited(inode->i_mapping);
3248 btrfs_throttle(fs_info);
3250 WARN_ON(nr != cluster->nr);
3256 static noinline_for_stack
3257 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
3258 struct file_extent_cluster *cluster)
3262 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3263 ret = relocate_file_extent_cluster(inode, cluster);
3270 cluster->start = extent_key->objectid;
3272 BUG_ON(cluster->nr >= MAX_EXTENTS);
3273 cluster->end = extent_key->objectid + extent_key->offset - 1;
3274 cluster->boundary[cluster->nr] = extent_key->objectid;
3277 if (cluster->nr >= MAX_EXTENTS) {
3278 ret = relocate_file_extent_cluster(inode, cluster);
3287 * helper to add a tree block to the list.
3288 * the major work is getting the generation and level of the block
3290 static int add_tree_block(struct reloc_control *rc,
3291 struct btrfs_key *extent_key,
3292 struct btrfs_path *path,
3293 struct rb_root *blocks)
3295 struct extent_buffer *eb;
3296 struct btrfs_extent_item *ei;
3297 struct btrfs_tree_block_info *bi;
3298 struct tree_block *block;
3299 struct rb_node *rb_node;
3304 eb = path->nodes[0];
3305 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3307 if (extent_key->type == BTRFS_METADATA_ITEM_KEY ||
3308 item_size >= sizeof(*ei) + sizeof(*bi)) {
3309 ei = btrfs_item_ptr(eb, path->slots[0],
3310 struct btrfs_extent_item);
3311 if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) {
3312 bi = (struct btrfs_tree_block_info *)(ei + 1);
3313 level = btrfs_tree_block_level(eb, bi);
3315 level = (int)extent_key->offset;
3317 generation = btrfs_extent_generation(eb, ei);
3322 btrfs_release_path(path);
3324 BUG_ON(level == -1);
3326 block = kmalloc(sizeof(*block), GFP_NOFS);
3330 block->bytenr = extent_key->objectid;
3331 block->key.objectid = rc->extent_root->fs_info->nodesize;
3332 block->key.offset = generation;
3333 block->level = level;
3334 block->key_ready = 0;
3336 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3338 backref_tree_panic(rb_node, -EEXIST, block->bytenr);
3344 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3346 static int __add_tree_block(struct reloc_control *rc,
3347 u64 bytenr, u32 blocksize,
3348 struct rb_root *blocks)
3350 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3351 struct btrfs_path *path;
3352 struct btrfs_key key;
3354 bool skinny = btrfs_fs_incompat(fs_info, SKINNY_METADATA);
3356 if (tree_block_processed(bytenr, rc))
3359 if (tree_search(blocks, bytenr))
3362 path = btrfs_alloc_path();
3366 key.objectid = bytenr;
3368 key.type = BTRFS_METADATA_ITEM_KEY;
3369 key.offset = (u64)-1;
3371 key.type = BTRFS_EXTENT_ITEM_KEY;
3372 key.offset = blocksize;
3375 path->search_commit_root = 1;
3376 path->skip_locking = 1;
3377 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3381 if (ret > 0 && skinny) {
3382 if (path->slots[0]) {
3384 btrfs_item_key_to_cpu(path->nodes[0], &key,
3386 if (key.objectid == bytenr &&
3387 (key.type == BTRFS_METADATA_ITEM_KEY ||
3388 (key.type == BTRFS_EXTENT_ITEM_KEY &&
3389 key.offset == blocksize)))
3395 btrfs_release_path(path);
3401 btrfs_print_leaf(path->nodes[0]);
3403 "tree block extent item (%llu) is not found in extent tree",
3410 ret = add_tree_block(rc, &key, path, blocks);
3412 btrfs_free_path(path);
3417 * helper to check if the block use full backrefs for pointers in it
3419 static int block_use_full_backref(struct reloc_control *rc,
3420 struct extent_buffer *eb)
3425 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3426 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3429 ret = btrfs_lookup_extent_info(NULL, rc->extent_root->fs_info,
3430 eb->start, btrfs_header_level(eb), 1,
3434 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3441 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3442 struct btrfs_block_group_cache *block_group,
3443 struct inode *inode,
3446 struct btrfs_key key;
3447 struct btrfs_root *root = fs_info->tree_root;
3448 struct btrfs_trans_handle *trans;
3455 key.type = BTRFS_INODE_ITEM_KEY;
3458 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3459 if (IS_ERR(inode) || is_bad_inode(inode)) {
3466 ret = btrfs_check_trunc_cache_free_space(fs_info,
3467 &fs_info->global_block_rsv);
3471 trans = btrfs_join_transaction(root);
3472 if (IS_ERR(trans)) {
3473 ret = PTR_ERR(trans);
3477 ret = btrfs_truncate_free_space_cache(trans, block_group, inode);
3479 btrfs_end_transaction(trans);
3480 btrfs_btree_balance_dirty(fs_info);
3487 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3488 * this function scans fs tree to find blocks reference the data extent
3490 static int find_data_references(struct reloc_control *rc,
3491 struct btrfs_key *extent_key,
3492 struct extent_buffer *leaf,
3493 struct btrfs_extent_data_ref *ref,
3494 struct rb_root *blocks)
3496 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3497 struct btrfs_path *path;
3498 struct tree_block *block;
3499 struct btrfs_root *root;
3500 struct btrfs_file_extent_item *fi;
3501 struct rb_node *rb_node;
3502 struct btrfs_key key;
3513 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3514 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3515 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3516 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3519 * This is an extent belonging to the free space cache, lets just delete
3520 * it and redo the search.
3522 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3523 ret = delete_block_group_cache(fs_info, rc->block_group,
3524 NULL, ref_objectid);
3530 path = btrfs_alloc_path();
3533 path->reada = READA_FORWARD;
3535 root = read_fs_root(fs_info, ref_root);
3537 err = PTR_ERR(root);
3541 key.objectid = ref_objectid;
3542 key.type = BTRFS_EXTENT_DATA_KEY;
3543 if (ref_offset > ((u64)-1 << 32))
3546 key.offset = ref_offset;
3548 path->search_commit_root = 1;
3549 path->skip_locking = 1;
3550 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3556 leaf = path->nodes[0];
3557 nritems = btrfs_header_nritems(leaf);
3559 * the references in tree blocks that use full backrefs
3560 * are not counted in
3562 if (block_use_full_backref(rc, leaf))
3566 rb_node = tree_search(blocks, leaf->start);
3571 path->slots[0] = nritems;
3574 while (ref_count > 0) {
3575 while (path->slots[0] >= nritems) {
3576 ret = btrfs_next_leaf(root, path);
3581 if (WARN_ON(ret > 0))
3584 leaf = path->nodes[0];
3585 nritems = btrfs_header_nritems(leaf);
3588 if (block_use_full_backref(rc, leaf))
3592 rb_node = tree_search(blocks, leaf->start);
3597 path->slots[0] = nritems;
3601 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3602 if (WARN_ON(key.objectid != ref_objectid ||
3603 key.type != BTRFS_EXTENT_DATA_KEY))
3606 fi = btrfs_item_ptr(leaf, path->slots[0],
3607 struct btrfs_file_extent_item);
3609 if (btrfs_file_extent_type(leaf, fi) ==
3610 BTRFS_FILE_EXTENT_INLINE)
3613 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3614 extent_key->objectid)
3617 key.offset -= btrfs_file_extent_offset(leaf, fi);
3618 if (key.offset != ref_offset)
3626 if (!tree_block_processed(leaf->start, rc)) {
3627 block = kmalloc(sizeof(*block), GFP_NOFS);
3632 block->bytenr = leaf->start;
3633 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3635 block->key_ready = 1;
3636 rb_node = tree_insert(blocks, block->bytenr,
3639 backref_tree_panic(rb_node, -EEXIST,
3645 path->slots[0] = nritems;
3651 btrfs_free_path(path);
3656 * helper to find all tree blocks that reference a given data extent
3658 static noinline_for_stack
3659 int add_data_references(struct reloc_control *rc,
3660 struct btrfs_key *extent_key,
3661 struct btrfs_path *path,
3662 struct rb_root *blocks)
3664 struct btrfs_key key;
3665 struct extent_buffer *eb;
3666 struct btrfs_extent_data_ref *dref;
3667 struct btrfs_extent_inline_ref *iref;
3670 u32 blocksize = rc->extent_root->fs_info->nodesize;
3674 eb = path->nodes[0];
3675 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3676 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3677 ptr += sizeof(struct btrfs_extent_item);
3680 iref = (struct btrfs_extent_inline_ref *)ptr;
3681 key.type = btrfs_get_extent_inline_ref_type(eb, iref,
3682 BTRFS_REF_TYPE_DATA);
3683 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3684 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3685 ret = __add_tree_block(rc, key.offset, blocksize,
3687 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3688 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3689 ret = find_data_references(rc, extent_key,
3693 btrfs_err(rc->extent_root->fs_info,
3694 "extent %llu slot %d has an invalid inline ref type",
3695 eb->start, path->slots[0]);
3701 ptr += btrfs_extent_inline_ref_size(key.type);
3707 eb = path->nodes[0];
3708 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3709 ret = btrfs_next_leaf(rc->extent_root, path);
3716 eb = path->nodes[0];
3719 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3720 if (key.objectid != extent_key->objectid)
3723 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3724 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3725 ret = __add_tree_block(rc, key.offset, blocksize,
3727 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3728 dref = btrfs_item_ptr(eb, path->slots[0],
3729 struct btrfs_extent_data_ref);
3730 ret = find_data_references(rc, extent_key,
3742 btrfs_release_path(path);
3744 free_block_list(blocks);
3749 * helper to find next unprocessed extent
3751 static noinline_for_stack
3752 int find_next_extent(struct reloc_control *rc, struct btrfs_path *path,
3753 struct btrfs_key *extent_key)
3755 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3756 struct btrfs_key key;
3757 struct extent_buffer *leaf;
3758 u64 start, end, last;
3761 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3764 if (rc->search_start >= last) {
3769 key.objectid = rc->search_start;
3770 key.type = BTRFS_EXTENT_ITEM_KEY;
3773 path->search_commit_root = 1;
3774 path->skip_locking = 1;
3775 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3780 leaf = path->nodes[0];
3781 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3782 ret = btrfs_next_leaf(rc->extent_root, path);
3785 leaf = path->nodes[0];
3788 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3789 if (key.objectid >= last) {
3794 if (key.type != BTRFS_EXTENT_ITEM_KEY &&
3795 key.type != BTRFS_METADATA_ITEM_KEY) {
3800 if (key.type == BTRFS_EXTENT_ITEM_KEY &&
3801 key.objectid + key.offset <= rc->search_start) {
3806 if (key.type == BTRFS_METADATA_ITEM_KEY &&
3807 key.objectid + fs_info->nodesize <=
3813 ret = find_first_extent_bit(&rc->processed_blocks,
3814 key.objectid, &start, &end,
3815 EXTENT_DIRTY, NULL);
3817 if (ret == 0 && start <= key.objectid) {
3818 btrfs_release_path(path);
3819 rc->search_start = end + 1;
3821 if (key.type == BTRFS_EXTENT_ITEM_KEY)
3822 rc->search_start = key.objectid + key.offset;
3824 rc->search_start = key.objectid +
3826 memcpy(extent_key, &key, sizeof(key));
3830 btrfs_release_path(path);
3834 static void set_reloc_control(struct reloc_control *rc)
3836 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3838 mutex_lock(&fs_info->reloc_mutex);
3839 fs_info->reloc_ctl = rc;
3840 mutex_unlock(&fs_info->reloc_mutex);
3843 static void unset_reloc_control(struct reloc_control *rc)
3845 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3847 mutex_lock(&fs_info->reloc_mutex);
3848 fs_info->reloc_ctl = NULL;
3849 mutex_unlock(&fs_info->reloc_mutex);
3852 static int check_extent_flags(u64 flags)
3854 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3855 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3857 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3858 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3860 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3861 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3866 static noinline_for_stack
3867 int prepare_to_relocate(struct reloc_control *rc)
3869 struct btrfs_trans_handle *trans;
3872 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root->fs_info,
3873 BTRFS_BLOCK_RSV_TEMP);
3877 memset(&rc->cluster, 0, sizeof(rc->cluster));
3878 rc->search_start = rc->block_group->key.objectid;
3879 rc->extents_found = 0;
3880 rc->nodes_relocated = 0;
3881 rc->merging_rsv_size = 0;
3882 rc->reserved_bytes = 0;
3883 rc->block_rsv->size = rc->extent_root->fs_info->nodesize *
3884 RELOCATION_RESERVED_NODES;
3885 ret = btrfs_block_rsv_refill(rc->extent_root,
3886 rc->block_rsv, rc->block_rsv->size,
3887 BTRFS_RESERVE_FLUSH_ALL);
3891 rc->create_reloc_tree = 1;
3892 set_reloc_control(rc);
3894 trans = btrfs_join_transaction(rc->extent_root);
3895 if (IS_ERR(trans)) {
3896 unset_reloc_control(rc);
3898 * extent tree is not a ref_cow tree and has no reloc_root to
3899 * cleanup. And callers are responsible to free the above
3902 return PTR_ERR(trans);
3904 btrfs_commit_transaction(trans);
3908 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3910 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3911 struct rb_root blocks = RB_ROOT;
3912 struct btrfs_key key;
3913 struct btrfs_trans_handle *trans = NULL;
3914 struct btrfs_path *path;
3915 struct btrfs_extent_item *ei;
3922 path = btrfs_alloc_path();
3925 path->reada = READA_FORWARD;
3927 ret = prepare_to_relocate(rc);
3934 rc->reserved_bytes = 0;
3935 ret = btrfs_block_rsv_refill(rc->extent_root,
3936 rc->block_rsv, rc->block_rsv->size,
3937 BTRFS_RESERVE_FLUSH_ALL);
3943 trans = btrfs_start_transaction(rc->extent_root, 0);
3944 if (IS_ERR(trans)) {
3945 err = PTR_ERR(trans);
3950 if (update_backref_cache(trans, &rc->backref_cache)) {
3951 btrfs_end_transaction(trans);
3955 ret = find_next_extent(rc, path, &key);
3961 rc->extents_found++;
3963 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3964 struct btrfs_extent_item);
3965 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3966 if (item_size >= sizeof(*ei)) {
3967 flags = btrfs_extent_flags(path->nodes[0], ei);
3968 ret = check_extent_flags(flags);
3975 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3976 ret = add_tree_block(rc, &key, path, &blocks);
3977 } else if (rc->stage == UPDATE_DATA_PTRS &&
3978 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3979 ret = add_data_references(rc, &key, path, &blocks);
3981 btrfs_release_path(path);
3989 if (!RB_EMPTY_ROOT(&blocks)) {
3990 ret = relocate_tree_blocks(trans, rc, &blocks);
3993 * if we fail to relocate tree blocks, force to update
3994 * backref cache when committing transaction.
3996 rc->backref_cache.last_trans = trans->transid - 1;
3998 if (ret != -EAGAIN) {
4002 rc->extents_found--;
4003 rc->search_start = key.objectid;
4007 btrfs_end_transaction_throttle(trans);
4008 btrfs_btree_balance_dirty(fs_info);
4011 if (rc->stage == MOVE_DATA_EXTENTS &&
4012 (flags & BTRFS_EXTENT_FLAG_DATA)) {
4013 rc->found_file_extent = 1;
4014 ret = relocate_data_extent(rc->data_inode,
4015 &key, &rc->cluster);
4022 if (trans && progress && err == -ENOSPC) {
4023 ret = btrfs_force_chunk_alloc(trans, rc->block_group->flags);
4031 btrfs_release_path(path);
4032 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY);
4035 btrfs_end_transaction_throttle(trans);
4036 btrfs_btree_balance_dirty(fs_info);
4040 ret = relocate_file_extent_cluster(rc->data_inode,
4046 rc->create_reloc_tree = 0;
4047 set_reloc_control(rc);
4049 backref_cache_cleanup(&rc->backref_cache);
4050 btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1);
4052 err = prepare_to_merge(rc, err);
4054 merge_reloc_roots(rc);
4056 rc->merge_reloc_tree = 0;
4057 unset_reloc_control(rc);
4058 btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1);
4060 /* get rid of pinned extents */
4061 trans = btrfs_join_transaction(rc->extent_root);
4062 if (IS_ERR(trans)) {
4063 err = PTR_ERR(trans);
4066 btrfs_commit_transaction(trans);
4068 btrfs_free_block_rsv(fs_info, rc->block_rsv);
4069 btrfs_free_path(path);
4073 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
4074 struct btrfs_root *root, u64 objectid)
4076 struct btrfs_path *path;
4077 struct btrfs_inode_item *item;
4078 struct extent_buffer *leaf;
4081 path = btrfs_alloc_path();
4085 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
4089 leaf = path->nodes[0];
4090 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
4091 memzero_extent_buffer(leaf, (unsigned long)item, sizeof(*item));
4092 btrfs_set_inode_generation(leaf, item, 1);
4093 btrfs_set_inode_size(leaf, item, 0);
4094 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
4095 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
4096 BTRFS_INODE_PREALLOC);
4097 btrfs_mark_buffer_dirty(leaf);
4099 btrfs_free_path(path);
4104 * helper to create inode for data relocation.
4105 * the inode is in data relocation tree and its link count is 0
4107 static noinline_for_stack
4108 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
4109 struct btrfs_block_group_cache *group)
4111 struct inode *inode = NULL;
4112 struct btrfs_trans_handle *trans;
4113 struct btrfs_root *root;
4114 struct btrfs_key key;
4118 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4120 return ERR_CAST(root);
4122 trans = btrfs_start_transaction(root, 6);
4124 return ERR_CAST(trans);
4126 err = btrfs_find_free_objectid(root, &objectid);
4130 err = __insert_orphan_inode(trans, root, objectid);
4133 key.objectid = objectid;
4134 key.type = BTRFS_INODE_ITEM_KEY;
4136 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
4137 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
4138 BTRFS_I(inode)->index_cnt = group->key.objectid;
4140 err = btrfs_orphan_add(trans, BTRFS_I(inode));
4142 btrfs_end_transaction(trans);
4143 btrfs_btree_balance_dirty(fs_info);
4147 inode = ERR_PTR(err);
4152 static struct reloc_control *alloc_reloc_control(void)
4154 struct reloc_control *rc;
4156 rc = kzalloc(sizeof(*rc), GFP_NOFS);
4160 INIT_LIST_HEAD(&rc->reloc_roots);
4161 backref_cache_init(&rc->backref_cache);
4162 mapping_tree_init(&rc->reloc_root_tree);
4163 extent_io_tree_init(&rc->processed_blocks, NULL);
4168 * Print the block group being relocated
4170 static void describe_relocation(struct btrfs_fs_info *fs_info,
4171 struct btrfs_block_group_cache *block_group)
4173 char buf[128]; /* prefixed by a '|' that'll be dropped */
4174 u64 flags = block_group->flags;
4176 /* Shouldn't happen */
4178 strcpy(buf, "|NONE");
4182 #define DESCRIBE_FLAG(f, d) \
4183 if (flags & BTRFS_BLOCK_GROUP_##f) { \
4184 bp += snprintf(bp, buf - bp + sizeof(buf), "|%s", d); \
4185 flags &= ~BTRFS_BLOCK_GROUP_##f; \
4187 DESCRIBE_FLAG(DATA, "data");
4188 DESCRIBE_FLAG(SYSTEM, "system");
4189 DESCRIBE_FLAG(METADATA, "metadata");
4190 DESCRIBE_FLAG(RAID0, "raid0");
4191 DESCRIBE_FLAG(RAID1, "raid1");
4192 DESCRIBE_FLAG(DUP, "dup");
4193 DESCRIBE_FLAG(RAID10, "raid10");
4194 DESCRIBE_FLAG(RAID5, "raid5");
4195 DESCRIBE_FLAG(RAID6, "raid6");
4197 snprintf(bp, buf - bp + sizeof(buf), "|0x%llx", flags);
4198 #undef DESCRIBE_FLAG
4202 "relocating block group %llu flags %s",
4203 block_group->key.objectid, buf + 1);
4207 * function to relocate all extents in a block group.
4209 int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start)
4211 struct btrfs_root *extent_root = fs_info->extent_root;
4212 struct reloc_control *rc;
4213 struct inode *inode;
4214 struct btrfs_path *path;
4219 rc = alloc_reloc_control();
4223 rc->extent_root = extent_root;
4225 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
4226 BUG_ON(!rc->block_group);
4228 ret = btrfs_inc_block_group_ro(rc->block_group);
4235 path = btrfs_alloc_path();
4241 inode = lookup_free_space_inode(fs_info, rc->block_group, path);
4242 btrfs_free_path(path);
4245 ret = delete_block_group_cache(fs_info, rc->block_group, inode, 0);
4247 ret = PTR_ERR(inode);
4249 if (ret && ret != -ENOENT) {
4254 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
4255 if (IS_ERR(rc->data_inode)) {
4256 err = PTR_ERR(rc->data_inode);
4257 rc->data_inode = NULL;
4261 describe_relocation(fs_info, rc->block_group);
4263 btrfs_wait_block_group_reservations(rc->block_group);
4264 btrfs_wait_nocow_writers(rc->block_group);
4265 btrfs_wait_ordered_roots(fs_info, U64_MAX,
4266 rc->block_group->key.objectid,
4267 rc->block_group->key.offset);
4270 mutex_lock(&fs_info->cleaner_mutex);
4271 ret = relocate_block_group(rc);
4272 mutex_unlock(&fs_info->cleaner_mutex);
4278 if (rc->extents_found == 0)
4281 btrfs_info(fs_info, "found %llu extents", rc->extents_found);
4283 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4284 ret = btrfs_wait_ordered_range(rc->data_inode, 0,
4290 invalidate_mapping_pages(rc->data_inode->i_mapping,
4292 rc->stage = UPDATE_DATA_PTRS;
4296 WARN_ON(rc->block_group->pinned > 0);
4297 WARN_ON(rc->block_group->reserved > 0);
4298 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4301 btrfs_dec_block_group_ro(rc->block_group);
4302 iput(rc->data_inode);
4303 btrfs_put_block_group(rc->block_group);
4308 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4310 struct btrfs_fs_info *fs_info = root->fs_info;
4311 struct btrfs_trans_handle *trans;
4314 trans = btrfs_start_transaction(fs_info->tree_root, 0);
4316 return PTR_ERR(trans);
4318 memset(&root->root_item.drop_progress, 0,
4319 sizeof(root->root_item.drop_progress));
4320 root->root_item.drop_level = 0;
4321 btrfs_set_root_refs(&root->root_item, 0);
4322 ret = btrfs_update_root(trans, fs_info->tree_root,
4323 &root->root_key, &root->root_item);
4325 err = btrfs_end_transaction(trans);
4332 * recover relocation interrupted by system crash.
4334 * this function resumes merging reloc trees with corresponding fs trees.
4335 * this is important for keeping the sharing of tree blocks
4337 int btrfs_recover_relocation(struct btrfs_root *root)
4339 struct btrfs_fs_info *fs_info = root->fs_info;
4340 LIST_HEAD(reloc_roots);
4341 struct btrfs_key key;
4342 struct btrfs_root *fs_root;
4343 struct btrfs_root *reloc_root;
4344 struct btrfs_path *path;
4345 struct extent_buffer *leaf;
4346 struct reloc_control *rc = NULL;
4347 struct btrfs_trans_handle *trans;
4351 path = btrfs_alloc_path();
4354 path->reada = READA_BACK;
4356 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4357 key.type = BTRFS_ROOT_ITEM_KEY;
4358 key.offset = (u64)-1;
4361 ret = btrfs_search_slot(NULL, fs_info->tree_root, &key,
4368 if (path->slots[0] == 0)
4372 leaf = path->nodes[0];
4373 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4374 btrfs_release_path(path);
4376 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4377 key.type != BTRFS_ROOT_ITEM_KEY)
4380 reloc_root = btrfs_read_fs_root(root, &key);
4381 if (IS_ERR(reloc_root)) {
4382 err = PTR_ERR(reloc_root);
4386 list_add(&reloc_root->root_list, &reloc_roots);
4388 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4389 fs_root = read_fs_root(fs_info,
4390 reloc_root->root_key.offset);
4391 if (IS_ERR(fs_root)) {
4392 ret = PTR_ERR(fs_root);
4393 if (ret != -ENOENT) {
4397 ret = mark_garbage_root(reloc_root);
4405 if (key.offset == 0)
4410 btrfs_release_path(path);
4412 if (list_empty(&reloc_roots))
4415 rc = alloc_reloc_control();
4421 rc->extent_root = fs_info->extent_root;
4423 set_reloc_control(rc);
4425 trans = btrfs_join_transaction(rc->extent_root);
4426 if (IS_ERR(trans)) {
4427 unset_reloc_control(rc);
4428 err = PTR_ERR(trans);
4432 rc->merge_reloc_tree = 1;
4434 while (!list_empty(&reloc_roots)) {
4435 reloc_root = list_entry(reloc_roots.next,
4436 struct btrfs_root, root_list);
4437 list_del(&reloc_root->root_list);
4439 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4440 list_add_tail(&reloc_root->root_list,
4445 fs_root = read_fs_root(fs_info, reloc_root->root_key.offset);
4446 if (IS_ERR(fs_root)) {
4447 err = PTR_ERR(fs_root);
4451 err = __add_reloc_root(reloc_root);
4452 BUG_ON(err < 0); /* -ENOMEM or logic error */
4453 fs_root->reloc_root = reloc_root;
4456 err = btrfs_commit_transaction(trans);
4460 merge_reloc_roots(rc);
4462 unset_reloc_control(rc);
4464 trans = btrfs_join_transaction(rc->extent_root);
4465 if (IS_ERR(trans)) {
4466 err = PTR_ERR(trans);
4469 err = btrfs_commit_transaction(trans);
4473 if (!list_empty(&reloc_roots))
4474 free_reloc_roots(&reloc_roots);
4476 btrfs_free_path(path);
4479 /* cleanup orphan inode in data relocation tree */
4480 fs_root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
4481 if (IS_ERR(fs_root))
4482 err = PTR_ERR(fs_root);
4484 err = btrfs_orphan_cleanup(fs_root);
4490 * helper to add ordered checksum for data relocation.
4492 * cloning checksum properly handles the nodatasum extents.
4493 * it also saves CPU time to re-calculate the checksum.
4495 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4497 struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
4498 struct btrfs_ordered_sum *sums;
4499 struct btrfs_ordered_extent *ordered;
4505 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4506 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4508 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4509 ret = btrfs_lookup_csums_range(fs_info->csum_root, disk_bytenr,
4510 disk_bytenr + len - 1, &list, 0);
4514 while (!list_empty(&list)) {
4515 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4516 list_del_init(&sums->list);
4519 * We need to offset the new_bytenr based on where the csum is.
4520 * We need to do this because we will read in entire prealloc
4521 * extents but we may have written to say the middle of the
4522 * prealloc extent, so we need to make sure the csum goes with
4523 * the right disk offset.
4525 * We can do this because the data reloc inode refers strictly
4526 * to the on disk bytes, so we don't have to worry about
4527 * disk_len vs real len like with real inodes since it's all
4530 new_bytenr = ordered->start + (sums->bytenr - disk_bytenr);
4531 sums->bytenr = new_bytenr;
4533 btrfs_add_ordered_sum(inode, ordered, sums);
4536 btrfs_put_ordered_extent(ordered);
4540 int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4541 struct btrfs_root *root, struct extent_buffer *buf,
4542 struct extent_buffer *cow)
4544 struct btrfs_fs_info *fs_info = root->fs_info;
4545 struct reloc_control *rc;
4546 struct backref_node *node;
4551 rc = fs_info->reloc_ctl;
4555 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4556 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4558 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
4559 if (buf == root->node)
4560 __update_reloc_root(root, cow->start);
4563 level = btrfs_header_level(buf);
4564 if (btrfs_header_generation(buf) <=
4565 btrfs_root_last_snapshot(&root->root_item))
4568 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4569 rc->create_reloc_tree) {
4570 WARN_ON(!first_cow && level == 0);
4572 node = rc->backref_cache.path[level];
4573 BUG_ON(node->bytenr != buf->start &&
4574 node->new_bytenr != buf->start);
4576 drop_node_buffer(node);
4577 extent_buffer_get(cow);
4579 node->new_bytenr = cow->start;
4581 if (!node->pending) {
4582 list_move_tail(&node->list,
4583 &rc->backref_cache.pending[level]);
4588 __mark_block_processed(rc, node);
4590 if (first_cow && level > 0)
4591 rc->nodes_relocated += buf->len;
4594 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS)
4595 ret = replace_file_extents(trans, rc, root, cow);
4600 * called before creating snapshot. it calculates metadata reservation
4601 * required for relocating tree blocks in the snapshot
4603 void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending,
4604 u64 *bytes_to_reserve)
4606 struct btrfs_root *root;
4607 struct reloc_control *rc;
4609 root = pending->root;
4610 if (!root->reloc_root)
4613 rc = root->fs_info->reloc_ctl;
4614 if (!rc->merge_reloc_tree)
4617 root = root->reloc_root;
4618 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4620 * relocation is in the stage of merging trees. the space
4621 * used by merging a reloc tree is twice the size of
4622 * relocated tree nodes in the worst case. half for cowing
4623 * the reloc tree, half for cowing the fs tree. the space
4624 * used by cowing the reloc tree will be freed after the
4625 * tree is dropped. if we create snapshot, cowing the fs
4626 * tree may use more space than it frees. so we need
4627 * reserve extra space.
4629 *bytes_to_reserve += rc->nodes_relocated;
4633 * called after snapshot is created. migrate block reservation
4634 * and create reloc root for the newly created snapshot
4636 int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4637 struct btrfs_pending_snapshot *pending)
4639 struct btrfs_root *root = pending->root;
4640 struct btrfs_root *reloc_root;
4641 struct btrfs_root *new_root;
4642 struct reloc_control *rc;
4645 if (!root->reloc_root)
4648 rc = root->fs_info->reloc_ctl;
4649 rc->merging_rsv_size += rc->nodes_relocated;
4651 if (rc->merge_reloc_tree) {
4652 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4654 rc->nodes_relocated, 1);
4659 new_root = pending->snap;
4660 reloc_root = create_reloc_root(trans, root->reloc_root,
4661 new_root->root_key.objectid);
4662 if (IS_ERR(reloc_root))
4663 return PTR_ERR(reloc_root);
4665 ret = __add_reloc_root(reloc_root);
4667 new_root->reloc_root = reloc_root;
4669 if (rc->create_reloc_tree)
4670 ret = clone_backref_node(trans, rc, root, reloc_root);