2 * Copyright (C) 2009 Oracle. All rights reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public
6 * License v2 as published by the Free Software Foundation.
8 * This program is distributed in the hope that it will be useful,
9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
11 * General Public License for more details.
13 * You should have received a copy of the GNU General Public
14 * License along with this program; if not, write to the
15 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 * Boston, MA 021110-1307, USA.
19 #include <linux/sched.h>
20 #include <linux/pagemap.h>
21 #include <linux/writeback.h>
22 #include <linux/blkdev.h>
23 #include <linux/rbtree.h>
24 #include <linux/slab.h>
27 #include "transaction.h"
30 #include "btrfs_inode.h"
31 #include "async-thread.h"
32 #include "free-space-cache.h"
35 * backref_node, mapping_node and tree_block start with this
38 struct rb_node rb_node;
43 * present a tree block in the backref cache
46 struct rb_node rb_node;
50 /* objectid of tree block owner, can be not uptodate */
52 /* link to pending, changed or detached list */
53 struct list_head list;
54 /* list of upper level blocks reference this block */
55 struct list_head upper;
56 /* list of child blocks in the cache */
57 struct list_head lower;
58 /* NULL if this node is not tree root */
59 struct btrfs_root *root;
60 /* extent buffer got by COW the block */
61 struct extent_buffer *eb;
62 /* level of tree block */
64 /* is the block in non-reference counted tree */
65 unsigned int cowonly:1;
66 /* 1 if no child node in the cache */
67 unsigned int lowest:1;
68 /* is the extent buffer locked */
69 unsigned int locked:1;
70 /* has the block been processed */
71 unsigned int processed:1;
72 /* have backrefs of this block been checked */
73 unsigned int checked:1;
75 * 1 if corresponding block has been cowed but some upper
76 * level block pointers may not point to the new location
78 unsigned int pending:1;
80 * 1 if the backref node isn't connected to any other
83 unsigned int detached:1;
87 * present a block pointer in the backref cache
90 struct list_head list[2];
91 struct backref_node *node[2];
97 struct backref_cache {
98 /* red black tree of all backref nodes in the cache */
99 struct rb_root rb_root;
100 /* for passing backref nodes to btrfs_reloc_cow_block */
101 struct backref_node *path[BTRFS_MAX_LEVEL];
103 * list of blocks that have been cowed but some block
104 * pointers in upper level blocks may not reflect the
107 struct list_head pending[BTRFS_MAX_LEVEL];
108 /* list of backref nodes with no child node */
109 struct list_head leaves;
110 /* list of blocks that have been cowed in current transaction */
111 struct list_head changed;
112 /* list of detached backref node. */
113 struct list_head detached;
122 * map address of tree root to tree
124 struct mapping_node {
125 struct rb_node rb_node;
130 struct mapping_tree {
131 struct rb_root rb_root;
136 * present a tree block to process
139 struct rb_node rb_node;
141 struct btrfs_key key;
142 unsigned int level:8;
143 unsigned int key_ready:1;
146 #define MAX_EXTENTS 128
148 struct file_extent_cluster {
151 u64 boundary[MAX_EXTENTS];
155 struct reloc_control {
156 /* block group to relocate */
157 struct btrfs_block_group_cache *block_group;
159 struct btrfs_root *extent_root;
160 /* inode for moving data */
161 struct inode *data_inode;
163 struct btrfs_block_rsv *block_rsv;
165 struct backref_cache backref_cache;
167 struct file_extent_cluster cluster;
168 /* tree blocks have been processed */
169 struct extent_io_tree processed_blocks;
170 /* map start of tree root to corresponding reloc tree */
171 struct mapping_tree reloc_root_tree;
172 /* list of reloc trees */
173 struct list_head reloc_roots;
174 /* size of metadata reservation for merging reloc trees */
175 u64 merging_rsv_size;
176 /* size of relocated tree nodes */
182 unsigned int stage:8;
183 unsigned int create_reloc_tree:1;
184 unsigned int merge_reloc_tree:1;
185 unsigned int found_file_extent:1;
186 unsigned int commit_transaction:1;
189 /* stages of data relocation */
190 #define MOVE_DATA_EXTENTS 0
191 #define UPDATE_DATA_PTRS 1
193 static void remove_backref_node(struct backref_cache *cache,
194 struct backref_node *node);
195 static void __mark_block_processed(struct reloc_control *rc,
196 struct backref_node *node);
198 static void mapping_tree_init(struct mapping_tree *tree)
200 tree->rb_root = RB_ROOT;
201 spin_lock_init(&tree->lock);
204 static void backref_cache_init(struct backref_cache *cache)
207 cache->rb_root = RB_ROOT;
208 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
209 INIT_LIST_HEAD(&cache->pending[i]);
210 INIT_LIST_HEAD(&cache->changed);
211 INIT_LIST_HEAD(&cache->detached);
212 INIT_LIST_HEAD(&cache->leaves);
215 static void backref_cache_cleanup(struct backref_cache *cache)
217 struct backref_node *node;
220 while (!list_empty(&cache->detached)) {
221 node = list_entry(cache->detached.next,
222 struct backref_node, list);
223 remove_backref_node(cache, node);
226 while (!list_empty(&cache->leaves)) {
227 node = list_entry(cache->leaves.next,
228 struct backref_node, lower);
229 remove_backref_node(cache, node);
232 cache->last_trans = 0;
234 for (i = 0; i < BTRFS_MAX_LEVEL; i++)
235 BUG_ON(!list_empty(&cache->pending[i]));
236 BUG_ON(!list_empty(&cache->changed));
237 BUG_ON(!list_empty(&cache->detached));
238 BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root));
239 BUG_ON(cache->nr_nodes);
240 BUG_ON(cache->nr_edges);
243 static struct backref_node *alloc_backref_node(struct backref_cache *cache)
245 struct backref_node *node;
247 node = kzalloc(sizeof(*node), GFP_NOFS);
249 INIT_LIST_HEAD(&node->list);
250 INIT_LIST_HEAD(&node->upper);
251 INIT_LIST_HEAD(&node->lower);
252 RB_CLEAR_NODE(&node->rb_node);
258 static void free_backref_node(struct backref_cache *cache,
259 struct backref_node *node)
267 static struct backref_edge *alloc_backref_edge(struct backref_cache *cache)
269 struct backref_edge *edge;
271 edge = kzalloc(sizeof(*edge), GFP_NOFS);
277 static void free_backref_edge(struct backref_cache *cache,
278 struct backref_edge *edge)
286 static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr,
287 struct rb_node *node)
289 struct rb_node **p = &root->rb_node;
290 struct rb_node *parent = NULL;
291 struct tree_entry *entry;
295 entry = rb_entry(parent, struct tree_entry, rb_node);
297 if (bytenr < entry->bytenr)
299 else if (bytenr > entry->bytenr)
305 rb_link_node(node, parent, p);
306 rb_insert_color(node, root);
310 static struct rb_node *tree_search(struct rb_root *root, u64 bytenr)
312 struct rb_node *n = root->rb_node;
313 struct tree_entry *entry;
316 entry = rb_entry(n, struct tree_entry, rb_node);
318 if (bytenr < entry->bytenr)
320 else if (bytenr > entry->bytenr)
329 * walk up backref nodes until reach node presents tree root
331 static struct backref_node *walk_up_backref(struct backref_node *node,
332 struct backref_edge *edges[],
335 struct backref_edge *edge;
338 while (!list_empty(&node->upper)) {
339 edge = list_entry(node->upper.next,
340 struct backref_edge, list[LOWER]);
342 node = edge->node[UPPER];
344 BUG_ON(node->detached);
350 * walk down backref nodes to find start of next reference path
352 static struct backref_node *walk_down_backref(struct backref_edge *edges[],
355 struct backref_edge *edge;
356 struct backref_node *lower;
360 edge = edges[idx - 1];
361 lower = edge->node[LOWER];
362 if (list_is_last(&edge->list[LOWER], &lower->upper)) {
366 edge = list_entry(edge->list[LOWER].next,
367 struct backref_edge, list[LOWER]);
368 edges[idx - 1] = edge;
370 return edge->node[UPPER];
376 static void unlock_node_buffer(struct backref_node *node)
379 btrfs_tree_unlock(node->eb);
384 static void drop_node_buffer(struct backref_node *node)
387 unlock_node_buffer(node);
388 free_extent_buffer(node->eb);
393 static void drop_backref_node(struct backref_cache *tree,
394 struct backref_node *node)
396 BUG_ON(!list_empty(&node->upper));
398 drop_node_buffer(node);
399 list_del(&node->list);
400 list_del(&node->lower);
401 if (!RB_EMPTY_NODE(&node->rb_node))
402 rb_erase(&node->rb_node, &tree->rb_root);
403 free_backref_node(tree, node);
407 * remove a backref node from the backref cache
409 static void remove_backref_node(struct backref_cache *cache,
410 struct backref_node *node)
412 struct backref_node *upper;
413 struct backref_edge *edge;
418 BUG_ON(!node->lowest && !node->detached);
419 while (!list_empty(&node->upper)) {
420 edge = list_entry(node->upper.next, struct backref_edge,
422 upper = edge->node[UPPER];
423 list_del(&edge->list[LOWER]);
424 list_del(&edge->list[UPPER]);
425 free_backref_edge(cache, edge);
427 if (RB_EMPTY_NODE(&upper->rb_node)) {
428 BUG_ON(!list_empty(&node->upper));
429 drop_backref_node(cache, node);
435 * add the node to leaf node list if no other
436 * child block cached.
438 if (list_empty(&upper->lower)) {
439 list_add_tail(&upper->lower, &cache->leaves);
444 drop_backref_node(cache, node);
447 static void update_backref_node(struct backref_cache *cache,
448 struct backref_node *node, u64 bytenr)
450 struct rb_node *rb_node;
451 rb_erase(&node->rb_node, &cache->rb_root);
452 node->bytenr = bytenr;
453 rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node);
458 * update backref cache after a transaction commit
460 static int update_backref_cache(struct btrfs_trans_handle *trans,
461 struct backref_cache *cache)
463 struct backref_node *node;
466 if (cache->last_trans == 0) {
467 cache->last_trans = trans->transid;
471 if (cache->last_trans == trans->transid)
475 * detached nodes are used to avoid unnecessary backref
476 * lookup. transaction commit changes the extent tree.
477 * so the detached nodes are no longer useful.
479 while (!list_empty(&cache->detached)) {
480 node = list_entry(cache->detached.next,
481 struct backref_node, list);
482 remove_backref_node(cache, node);
485 while (!list_empty(&cache->changed)) {
486 node = list_entry(cache->changed.next,
487 struct backref_node, list);
488 list_del_init(&node->list);
489 BUG_ON(node->pending);
490 update_backref_node(cache, node, node->new_bytenr);
494 * some nodes can be left in the pending list if there were
495 * errors during processing the pending nodes.
497 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
498 list_for_each_entry(node, &cache->pending[level], list) {
499 BUG_ON(!node->pending);
500 if (node->bytenr == node->new_bytenr)
502 update_backref_node(cache, node, node->new_bytenr);
506 cache->last_trans = 0;
510 static int should_ignore_root(struct btrfs_root *root)
512 struct btrfs_root *reloc_root;
517 reloc_root = root->reloc_root;
521 if (btrfs_root_last_snapshot(&reloc_root->root_item) ==
522 root->fs_info->running_transaction->transid - 1)
525 * if there is reloc tree and it was created in previous
526 * transaction backref lookup can find the reloc tree,
527 * so backref node for the fs tree root is useless for
534 * find reloc tree by address of tree root
536 static struct btrfs_root *find_reloc_root(struct reloc_control *rc,
539 struct rb_node *rb_node;
540 struct mapping_node *node;
541 struct btrfs_root *root = NULL;
543 spin_lock(&rc->reloc_root_tree.lock);
544 rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr);
546 node = rb_entry(rb_node, struct mapping_node, rb_node);
547 root = (struct btrfs_root *)node->data;
549 spin_unlock(&rc->reloc_root_tree.lock);
553 static int is_cowonly_root(u64 root_objectid)
555 if (root_objectid == BTRFS_ROOT_TREE_OBJECTID ||
556 root_objectid == BTRFS_EXTENT_TREE_OBJECTID ||
557 root_objectid == BTRFS_CHUNK_TREE_OBJECTID ||
558 root_objectid == BTRFS_DEV_TREE_OBJECTID ||
559 root_objectid == BTRFS_TREE_LOG_OBJECTID ||
560 root_objectid == BTRFS_CSUM_TREE_OBJECTID)
565 static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info,
568 struct btrfs_key key;
570 key.objectid = root_objectid;
571 key.type = BTRFS_ROOT_ITEM_KEY;
572 if (is_cowonly_root(root_objectid))
575 key.offset = (u64)-1;
577 return btrfs_read_fs_root_no_name(fs_info, &key);
580 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
581 static noinline_for_stack
582 struct btrfs_root *find_tree_root(struct reloc_control *rc,
583 struct extent_buffer *leaf,
584 struct btrfs_extent_ref_v0 *ref0)
586 struct btrfs_root *root;
587 u64 root_objectid = btrfs_ref_root_v0(leaf, ref0);
588 u64 generation = btrfs_ref_generation_v0(leaf, ref0);
590 BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID);
592 root = read_fs_root(rc->extent_root->fs_info, root_objectid);
593 BUG_ON(IS_ERR(root));
595 if (root->ref_cows &&
596 generation != btrfs_root_generation(&root->root_item))
603 static noinline_for_stack
604 int find_inline_backref(struct extent_buffer *leaf, int slot,
605 unsigned long *ptr, unsigned long *end)
607 struct btrfs_extent_item *ei;
608 struct btrfs_tree_block_info *bi;
611 item_size = btrfs_item_size_nr(leaf, slot);
612 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
613 if (item_size < sizeof(*ei)) {
614 WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0));
618 ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item);
619 WARN_ON(!(btrfs_extent_flags(leaf, ei) &
620 BTRFS_EXTENT_FLAG_TREE_BLOCK));
622 if (item_size <= sizeof(*ei) + sizeof(*bi)) {
623 WARN_ON(item_size < sizeof(*ei) + sizeof(*bi));
627 bi = (struct btrfs_tree_block_info *)(ei + 1);
628 *ptr = (unsigned long)(bi + 1);
629 *end = (unsigned long)ei + item_size;
634 * build backref tree for a given tree block. root of the backref tree
635 * corresponds the tree block, leaves of the backref tree correspond
636 * roots of b-trees that reference the tree block.
638 * the basic idea of this function is check backrefs of a given block
639 * to find upper level blocks that refernece the block, and then check
640 * bakcrefs of these upper level blocks recursively. the recursion stop
641 * when tree root is reached or backrefs for the block is cached.
643 * NOTE: if we find backrefs for a block are cached, we know backrefs
644 * for all upper level blocks that directly/indirectly reference the
645 * block are also cached.
647 static noinline_for_stack
648 struct backref_node *build_backref_tree(struct reloc_control *rc,
649 struct btrfs_key *node_key,
650 int level, u64 bytenr)
652 struct backref_cache *cache = &rc->backref_cache;
653 struct btrfs_path *path1;
654 struct btrfs_path *path2;
655 struct extent_buffer *eb;
656 struct btrfs_root *root;
657 struct backref_node *cur;
658 struct backref_node *upper;
659 struct backref_node *lower;
660 struct backref_node *node = NULL;
661 struct backref_node *exist = NULL;
662 struct backref_edge *edge;
663 struct rb_node *rb_node;
664 struct btrfs_key key;
673 path1 = btrfs_alloc_path();
674 path2 = btrfs_alloc_path();
675 if (!path1 || !path2) {
680 node = alloc_backref_node(cache);
686 node->bytenr = bytenr;
693 key.objectid = cur->bytenr;
694 key.type = BTRFS_EXTENT_ITEM_KEY;
695 key.offset = (u64)-1;
697 path1->search_commit_root = 1;
698 path1->skip_locking = 1;
699 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1,
705 BUG_ON(!ret || !path1->slots[0]);
709 WARN_ON(cur->checked);
710 if (!list_empty(&cur->upper)) {
712 * the backref was added previously when processsing
713 * backref of type BTRFS_TREE_BLOCK_REF_KEY
715 BUG_ON(!list_is_singular(&cur->upper));
716 edge = list_entry(cur->upper.next, struct backref_edge,
718 BUG_ON(!list_empty(&edge->list[UPPER]));
719 exist = edge->node[UPPER];
721 * add the upper level block to pending list if we need
725 list_add_tail(&edge->list[UPPER], &list);
732 eb = path1->nodes[0];
735 if (path1->slots[0] >= btrfs_header_nritems(eb)) {
736 ret = btrfs_next_leaf(rc->extent_root, path1);
743 eb = path1->nodes[0];
746 btrfs_item_key_to_cpu(eb, &key, path1->slots[0]);
747 if (key.objectid != cur->bytenr) {
752 if (key.type == BTRFS_EXTENT_ITEM_KEY) {
753 ret = find_inline_backref(eb, path1->slots[0],
761 /* update key for inline back ref */
762 struct btrfs_extent_inline_ref *iref;
763 iref = (struct btrfs_extent_inline_ref *)ptr;
764 key.type = btrfs_extent_inline_ref_type(eb, iref);
765 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
766 WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY &&
767 key.type != BTRFS_SHARED_BLOCK_REF_KEY);
771 ((key.type == BTRFS_TREE_BLOCK_REF_KEY &&
772 exist->owner == key.offset) ||
773 (key.type == BTRFS_SHARED_BLOCK_REF_KEY &&
774 exist->bytenr == key.offset))) {
779 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
780 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY ||
781 key.type == BTRFS_EXTENT_REF_V0_KEY) {
782 if (key.type == BTRFS_EXTENT_REF_V0_KEY) {
783 struct btrfs_extent_ref_v0 *ref0;
784 ref0 = btrfs_item_ptr(eb, path1->slots[0],
785 struct btrfs_extent_ref_v0);
786 if (key.objectid == key.offset) {
787 root = find_tree_root(rc, eb, ref0);
788 if (root && !should_ignore_root(root))
791 list_add(&cur->list, &useless);
794 if (is_cowonly_root(btrfs_ref_root_v0(eb,
799 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
800 if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) {
802 if (key.objectid == key.offset) {
804 * only root blocks of reloc trees use
805 * backref of this type.
807 root = find_reloc_root(rc, cur->bytenr);
813 edge = alloc_backref_edge(cache);
818 rb_node = tree_search(&cache->rb_root, key.offset);
820 upper = alloc_backref_node(cache);
822 free_backref_edge(cache, edge);
826 upper->bytenr = key.offset;
827 upper->level = cur->level + 1;
829 * backrefs for the upper level block isn't
830 * cached, add the block to pending list
832 list_add_tail(&edge->list[UPPER], &list);
834 upper = rb_entry(rb_node, struct backref_node,
836 BUG_ON(!upper->checked);
837 INIT_LIST_HEAD(&edge->list[UPPER]);
839 list_add_tail(&edge->list[LOWER], &cur->upper);
840 edge->node[LOWER] = cur;
841 edge->node[UPPER] = upper;
844 } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) {
848 /* key.type == BTRFS_TREE_BLOCK_REF_KEY */
849 root = read_fs_root(rc->extent_root->fs_info, key.offset);
858 if (btrfs_root_level(&root->root_item) == cur->level) {
860 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
862 if (should_ignore_root(root))
863 list_add(&cur->list, &useless);
869 level = cur->level + 1;
872 * searching the tree to find upper level blocks
873 * reference the block.
875 path2->search_commit_root = 1;
876 path2->skip_locking = 1;
877 path2->lowest_level = level;
878 ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0);
879 path2->lowest_level = 0;
884 if (ret > 0 && path2->slots[level] > 0)
885 path2->slots[level]--;
887 eb = path2->nodes[level];
888 WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) !=
892 for (; level < BTRFS_MAX_LEVEL; level++) {
893 if (!path2->nodes[level]) {
894 BUG_ON(btrfs_root_bytenr(&root->root_item) !=
896 if (should_ignore_root(root))
897 list_add(&lower->list, &useless);
903 edge = alloc_backref_edge(cache);
909 eb = path2->nodes[level];
910 rb_node = tree_search(&cache->rb_root, eb->start);
912 upper = alloc_backref_node(cache);
914 free_backref_edge(cache, edge);
918 upper->bytenr = eb->start;
919 upper->owner = btrfs_header_owner(eb);
920 upper->level = lower->level + 1;
925 * if we know the block isn't shared
926 * we can void checking its backrefs.
928 if (btrfs_block_can_be_shared(root, eb))
934 * add the block to pending list if we
935 * need check its backrefs. only block
936 * at 'cur->level + 1' is added to the
937 * tail of pending list. this guarantees
938 * we check backrefs from lower level
939 * blocks to upper level blocks.
941 if (!upper->checked &&
942 level == cur->level + 1) {
943 list_add_tail(&edge->list[UPPER],
946 INIT_LIST_HEAD(&edge->list[UPPER]);
948 upper = rb_entry(rb_node, struct backref_node,
950 BUG_ON(!upper->checked);
951 INIT_LIST_HEAD(&edge->list[UPPER]);
953 upper->owner = btrfs_header_owner(eb);
955 list_add_tail(&edge->list[LOWER], &lower->upper);
956 edge->node[LOWER] = lower;
957 edge->node[UPPER] = upper;
964 btrfs_release_path(root, path2);
967 ptr += btrfs_extent_inline_ref_size(key.type);
977 btrfs_release_path(rc->extent_root, path1);
982 /* the pending list isn't empty, take the first block to process */
983 if (!list_empty(&list)) {
984 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
985 list_del_init(&edge->list[UPPER]);
986 cur = edge->node[UPPER];
991 * everything goes well, connect backref nodes and insert backref nodes
994 BUG_ON(!node->checked);
995 cowonly = node->cowonly;
997 rb_node = tree_insert(&cache->rb_root, node->bytenr,
1000 list_add_tail(&node->lower, &cache->leaves);
1003 list_for_each_entry(edge, &node->upper, list[LOWER])
1004 list_add_tail(&edge->list[UPPER], &list);
1006 while (!list_empty(&list)) {
1007 edge = list_entry(list.next, struct backref_edge, list[UPPER]);
1008 list_del_init(&edge->list[UPPER]);
1009 upper = edge->node[UPPER];
1010 if (upper->detached) {
1011 list_del(&edge->list[LOWER]);
1012 lower = edge->node[LOWER];
1013 free_backref_edge(cache, edge);
1014 if (list_empty(&lower->upper))
1015 list_add(&lower->list, &useless);
1019 if (!RB_EMPTY_NODE(&upper->rb_node)) {
1020 if (upper->lowest) {
1021 list_del_init(&upper->lower);
1025 list_add_tail(&edge->list[UPPER], &upper->lower);
1029 BUG_ON(!upper->checked);
1030 BUG_ON(cowonly != upper->cowonly);
1032 rb_node = tree_insert(&cache->rb_root, upper->bytenr,
1037 list_add_tail(&edge->list[UPPER], &upper->lower);
1039 list_for_each_entry(edge, &upper->upper, list[LOWER])
1040 list_add_tail(&edge->list[UPPER], &list);
1043 * process useless backref nodes. backref nodes for tree leaves
1044 * are deleted from the cache. backref nodes for upper level
1045 * tree blocks are left in the cache to avoid unnecessary backref
1048 while (!list_empty(&useless)) {
1049 upper = list_entry(useless.next, struct backref_node, list);
1050 list_del_init(&upper->list);
1051 BUG_ON(!list_empty(&upper->upper));
1054 if (upper->lowest) {
1055 list_del_init(&upper->lower);
1058 while (!list_empty(&upper->lower)) {
1059 edge = list_entry(upper->lower.next,
1060 struct backref_edge, list[UPPER]);
1061 list_del(&edge->list[UPPER]);
1062 list_del(&edge->list[LOWER]);
1063 lower = edge->node[LOWER];
1064 free_backref_edge(cache, edge);
1066 if (list_empty(&lower->upper))
1067 list_add(&lower->list, &useless);
1069 __mark_block_processed(rc, upper);
1070 if (upper->level > 0) {
1071 list_add(&upper->list, &cache->detached);
1072 upper->detached = 1;
1074 rb_erase(&upper->rb_node, &cache->rb_root);
1075 free_backref_node(cache, upper);
1079 btrfs_free_path(path1);
1080 btrfs_free_path(path2);
1082 while (!list_empty(&useless)) {
1083 lower = list_entry(useless.next,
1084 struct backref_node, upper);
1085 list_del_init(&lower->upper);
1088 INIT_LIST_HEAD(&list);
1090 if (RB_EMPTY_NODE(&upper->rb_node)) {
1091 list_splice_tail(&upper->upper, &list);
1092 free_backref_node(cache, upper);
1095 if (list_empty(&list))
1098 edge = list_entry(list.next, struct backref_edge,
1100 list_del(&edge->list[LOWER]);
1101 upper = edge->node[UPPER];
1102 free_backref_edge(cache, edge);
1104 return ERR_PTR(err);
1106 BUG_ON(node && node->detached);
1111 * helper to add backref node for the newly created snapshot.
1112 * the backref node is created by cloning backref node that
1113 * corresponds to root of source tree
1115 static int clone_backref_node(struct btrfs_trans_handle *trans,
1116 struct reloc_control *rc,
1117 struct btrfs_root *src,
1118 struct btrfs_root *dest)
1120 struct btrfs_root *reloc_root = src->reloc_root;
1121 struct backref_cache *cache = &rc->backref_cache;
1122 struct backref_node *node = NULL;
1123 struct backref_node *new_node;
1124 struct backref_edge *edge;
1125 struct backref_edge *new_edge;
1126 struct rb_node *rb_node;
1128 if (cache->last_trans > 0)
1129 update_backref_cache(trans, cache);
1131 rb_node = tree_search(&cache->rb_root, src->commit_root->start);
1133 node = rb_entry(rb_node, struct backref_node, rb_node);
1137 BUG_ON(node->new_bytenr != reloc_root->node->start);
1141 rb_node = tree_search(&cache->rb_root,
1142 reloc_root->commit_root->start);
1144 node = rb_entry(rb_node, struct backref_node,
1146 BUG_ON(node->detached);
1153 new_node = alloc_backref_node(cache);
1157 new_node->bytenr = dest->node->start;
1158 new_node->level = node->level;
1159 new_node->lowest = node->lowest;
1160 new_node->root = dest;
1162 if (!node->lowest) {
1163 list_for_each_entry(edge, &node->lower, list[UPPER]) {
1164 new_edge = alloc_backref_edge(cache);
1168 new_edge->node[UPPER] = new_node;
1169 new_edge->node[LOWER] = edge->node[LOWER];
1170 list_add_tail(&new_edge->list[UPPER],
1175 rb_node = tree_insert(&cache->rb_root, new_node->bytenr,
1176 &new_node->rb_node);
1179 if (!new_node->lowest) {
1180 list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) {
1181 list_add_tail(&new_edge->list[LOWER],
1182 &new_edge->node[LOWER]->upper);
1187 while (!list_empty(&new_node->lower)) {
1188 new_edge = list_entry(new_node->lower.next,
1189 struct backref_edge, list[UPPER]);
1190 list_del(&new_edge->list[UPPER]);
1191 free_backref_edge(cache, new_edge);
1193 free_backref_node(cache, new_node);
1198 * helper to add 'address of tree root -> reloc tree' mapping
1200 static int __add_reloc_root(struct btrfs_root *root)
1202 struct rb_node *rb_node;
1203 struct mapping_node *node;
1204 struct reloc_control *rc = root->fs_info->reloc_ctl;
1206 node = kmalloc(sizeof(*node), GFP_NOFS);
1209 node->bytenr = root->node->start;
1212 spin_lock(&rc->reloc_root_tree.lock);
1213 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1214 node->bytenr, &node->rb_node);
1215 spin_unlock(&rc->reloc_root_tree.lock);
1218 list_add_tail(&root->root_list, &rc->reloc_roots);
1223 * helper to update/delete the 'address of tree root -> reloc tree'
1226 static int __update_reloc_root(struct btrfs_root *root, int del)
1228 struct rb_node *rb_node;
1229 struct mapping_node *node = NULL;
1230 struct reloc_control *rc = root->fs_info->reloc_ctl;
1232 spin_lock(&rc->reloc_root_tree.lock);
1233 rb_node = tree_search(&rc->reloc_root_tree.rb_root,
1234 root->commit_root->start);
1236 node = rb_entry(rb_node, struct mapping_node, rb_node);
1237 rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
1239 spin_unlock(&rc->reloc_root_tree.lock);
1241 BUG_ON((struct btrfs_root *)node->data != root);
1244 spin_lock(&rc->reloc_root_tree.lock);
1245 node->bytenr = root->node->start;
1246 rb_node = tree_insert(&rc->reloc_root_tree.rb_root,
1247 node->bytenr, &node->rb_node);
1248 spin_unlock(&rc->reloc_root_tree.lock);
1251 list_del_init(&root->root_list);
1257 static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans,
1258 struct btrfs_root *root, u64 objectid)
1260 struct btrfs_root *reloc_root;
1261 struct extent_buffer *eb;
1262 struct btrfs_root_item *root_item;
1263 struct btrfs_key root_key;
1266 root_item = kmalloc(sizeof(*root_item), GFP_NOFS);
1269 root_key.objectid = BTRFS_TREE_RELOC_OBJECTID;
1270 root_key.type = BTRFS_ROOT_ITEM_KEY;
1271 root_key.offset = objectid;
1273 if (root->root_key.objectid == objectid) {
1274 /* called by btrfs_init_reloc_root */
1275 ret = btrfs_copy_root(trans, root, root->commit_root, &eb,
1276 BTRFS_TREE_RELOC_OBJECTID);
1279 btrfs_set_root_last_snapshot(&root->root_item,
1280 trans->transid - 1);
1283 * called by btrfs_reloc_post_snapshot_hook.
1284 * the source tree is a reloc tree, all tree blocks
1285 * modified after it was created have RELOC flag
1286 * set in their headers. so it's OK to not update
1287 * the 'last_snapshot'.
1289 ret = btrfs_copy_root(trans, root, root->node, &eb,
1290 BTRFS_TREE_RELOC_OBJECTID);
1294 memcpy(root_item, &root->root_item, sizeof(*root_item));
1295 btrfs_set_root_bytenr(root_item, eb->start);
1296 btrfs_set_root_level(root_item, btrfs_header_level(eb));
1297 btrfs_set_root_generation(root_item, trans->transid);
1299 if (root->root_key.objectid == objectid) {
1300 btrfs_set_root_refs(root_item, 0);
1301 memset(&root_item->drop_progress, 0,
1302 sizeof(struct btrfs_disk_key));
1303 root_item->drop_level = 0;
1306 btrfs_tree_unlock(eb);
1307 free_extent_buffer(eb);
1309 ret = btrfs_insert_root(trans, root->fs_info->tree_root,
1310 &root_key, root_item);
1314 reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root,
1316 BUG_ON(IS_ERR(reloc_root));
1317 reloc_root->last_trans = trans->transid;
1322 * create reloc tree for a given fs tree. reloc tree is just a
1323 * snapshot of the fs tree with special root objectid.
1325 int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
1326 struct btrfs_root *root)
1328 struct btrfs_root *reloc_root;
1329 struct reloc_control *rc = root->fs_info->reloc_ctl;
1332 if (root->reloc_root) {
1333 reloc_root = root->reloc_root;
1334 reloc_root->last_trans = trans->transid;
1338 if (!rc || !rc->create_reloc_tree ||
1339 root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1342 if (!trans->block_rsv) {
1343 trans->block_rsv = rc->block_rsv;
1346 reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
1348 trans->block_rsv = NULL;
1350 __add_reloc_root(reloc_root);
1351 root->reloc_root = reloc_root;
1356 * update root item of reloc tree
1358 int btrfs_update_reloc_root(struct btrfs_trans_handle *trans,
1359 struct btrfs_root *root)
1361 struct btrfs_root *reloc_root;
1362 struct btrfs_root_item *root_item;
1366 if (!root->reloc_root)
1369 reloc_root = root->reloc_root;
1370 root_item = &reloc_root->root_item;
1372 if (root->fs_info->reloc_ctl->merge_reloc_tree &&
1373 btrfs_root_refs(root_item) == 0) {
1374 root->reloc_root = NULL;
1378 __update_reloc_root(reloc_root, del);
1380 if (reloc_root->commit_root != reloc_root->node) {
1381 btrfs_set_root_node(root_item, reloc_root->node);
1382 free_extent_buffer(reloc_root->commit_root);
1383 reloc_root->commit_root = btrfs_root_node(reloc_root);
1386 ret = btrfs_update_root(trans, root->fs_info->tree_root,
1387 &reloc_root->root_key, root_item);
1393 * helper to find first cached inode with inode number >= objectid
1396 static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid)
1398 struct rb_node *node;
1399 struct rb_node *prev;
1400 struct btrfs_inode *entry;
1401 struct inode *inode;
1403 spin_lock(&root->inode_lock);
1405 node = root->inode_tree.rb_node;
1409 entry = rb_entry(node, struct btrfs_inode, rb_node);
1411 if (objectid < entry->vfs_inode.i_ino)
1412 node = node->rb_left;
1413 else if (objectid > entry->vfs_inode.i_ino)
1414 node = node->rb_right;
1420 entry = rb_entry(prev, struct btrfs_inode, rb_node);
1421 if (objectid <= entry->vfs_inode.i_ino) {
1425 prev = rb_next(prev);
1429 entry = rb_entry(node, struct btrfs_inode, rb_node);
1430 inode = igrab(&entry->vfs_inode);
1432 spin_unlock(&root->inode_lock);
1436 objectid = entry->vfs_inode.i_ino + 1;
1437 if (cond_resched_lock(&root->inode_lock))
1440 node = rb_next(node);
1442 spin_unlock(&root->inode_lock);
1446 static int in_block_group(u64 bytenr,
1447 struct btrfs_block_group_cache *block_group)
1449 if (bytenr >= block_group->key.objectid &&
1450 bytenr < block_group->key.objectid + block_group->key.offset)
1456 * get new location of data
1458 static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr,
1459 u64 bytenr, u64 num_bytes)
1461 struct btrfs_root *root = BTRFS_I(reloc_inode)->root;
1462 struct btrfs_path *path;
1463 struct btrfs_file_extent_item *fi;
1464 struct extent_buffer *leaf;
1467 path = btrfs_alloc_path();
1471 bytenr -= BTRFS_I(reloc_inode)->index_cnt;
1472 ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino,
1481 leaf = path->nodes[0];
1482 fi = btrfs_item_ptr(leaf, path->slots[0],
1483 struct btrfs_file_extent_item);
1485 BUG_ON(btrfs_file_extent_offset(leaf, fi) ||
1486 btrfs_file_extent_compression(leaf, fi) ||
1487 btrfs_file_extent_encryption(leaf, fi) ||
1488 btrfs_file_extent_other_encoding(leaf, fi));
1490 if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) {
1495 *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1498 btrfs_free_path(path);
1503 * update file extent items in the tree leaf to point to
1504 * the new locations.
1506 static noinline_for_stack
1507 int replace_file_extents(struct btrfs_trans_handle *trans,
1508 struct reloc_control *rc,
1509 struct btrfs_root *root,
1510 struct extent_buffer *leaf)
1512 struct btrfs_key key;
1513 struct btrfs_file_extent_item *fi;
1514 struct inode *inode = NULL;
1526 if (rc->stage != UPDATE_DATA_PTRS)
1529 /* reloc trees always use full backref */
1530 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID)
1531 parent = leaf->start;
1535 nritems = btrfs_header_nritems(leaf);
1536 for (i = 0; i < nritems; i++) {
1538 btrfs_item_key_to_cpu(leaf, &key, i);
1539 if (key.type != BTRFS_EXTENT_DATA_KEY)
1541 fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item);
1542 if (btrfs_file_extent_type(leaf, fi) ==
1543 BTRFS_FILE_EXTENT_INLINE)
1545 bytenr = btrfs_file_extent_disk_bytenr(leaf, fi);
1546 num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi);
1549 if (!in_block_group(bytenr, rc->block_group))
1553 * if we are modifying block in fs tree, wait for readpage
1554 * to complete and drop the extent cache
1556 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) {
1558 inode = find_next_inode(root, key.objectid);
1560 } else if (inode && inode->i_ino < key.objectid) {
1561 btrfs_add_delayed_iput(inode);
1562 inode = find_next_inode(root, key.objectid);
1564 if (inode && inode->i_ino == key.objectid) {
1566 btrfs_file_extent_num_bytes(leaf, fi);
1567 WARN_ON(!IS_ALIGNED(key.offset,
1569 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1571 ret = try_lock_extent(&BTRFS_I(inode)->io_tree,
1577 btrfs_drop_extent_cache(inode, key.offset, end,
1579 unlock_extent(&BTRFS_I(inode)->io_tree,
1580 key.offset, end, GFP_NOFS);
1584 ret = get_new_location(rc->data_inode, &new_bytenr,
1592 btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr);
1595 key.offset -= btrfs_file_extent_offset(leaf, fi);
1596 ret = btrfs_inc_extent_ref(trans, root, new_bytenr,
1598 btrfs_header_owner(leaf),
1599 key.objectid, key.offset);
1602 ret = btrfs_free_extent(trans, root, bytenr, num_bytes,
1603 parent, btrfs_header_owner(leaf),
1604 key.objectid, key.offset);
1608 btrfs_mark_buffer_dirty(leaf);
1610 btrfs_add_delayed_iput(inode);
1614 static noinline_for_stack
1615 int memcmp_node_keys(struct extent_buffer *eb, int slot,
1616 struct btrfs_path *path, int level)
1618 struct btrfs_disk_key key1;
1619 struct btrfs_disk_key key2;
1620 btrfs_node_key(eb, &key1, slot);
1621 btrfs_node_key(path->nodes[level], &key2, path->slots[level]);
1622 return memcmp(&key1, &key2, sizeof(key1));
1626 * try to replace tree blocks in fs tree with the new blocks
1627 * in reloc tree. tree blocks haven't been modified since the
1628 * reloc tree was create can be replaced.
1630 * if a block was replaced, level of the block + 1 is returned.
1631 * if no block got replaced, 0 is returned. if there are other
1632 * errors, a negative error number is returned.
1634 static noinline_for_stack
1635 int replace_path(struct btrfs_trans_handle *trans,
1636 struct btrfs_root *dest, struct btrfs_root *src,
1637 struct btrfs_path *path, struct btrfs_key *next_key,
1638 int lowest_level, int max_level)
1640 struct extent_buffer *eb;
1641 struct extent_buffer *parent;
1642 struct btrfs_key key;
1654 BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID);
1655 BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID);
1657 last_snapshot = btrfs_root_last_snapshot(&src->root_item);
1659 slot = path->slots[lowest_level];
1660 btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot);
1662 eb = btrfs_lock_root_node(dest);
1663 btrfs_set_lock_blocking(eb);
1664 level = btrfs_header_level(eb);
1666 if (level < lowest_level) {
1667 btrfs_tree_unlock(eb);
1668 free_extent_buffer(eb);
1673 ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb);
1676 btrfs_set_lock_blocking(eb);
1679 next_key->objectid = (u64)-1;
1680 next_key->type = (u8)-1;
1681 next_key->offset = (u64)-1;
1686 level = btrfs_header_level(parent);
1687 BUG_ON(level < lowest_level);
1689 ret = btrfs_bin_search(parent, &key, level, &slot);
1690 if (ret && slot > 0)
1693 if (next_key && slot + 1 < btrfs_header_nritems(parent))
1694 btrfs_node_key_to_cpu(parent, next_key, slot + 1);
1696 old_bytenr = btrfs_node_blockptr(parent, slot);
1697 blocksize = btrfs_level_size(dest, level - 1);
1698 old_ptr_gen = btrfs_node_ptr_generation(parent, slot);
1700 if (level <= max_level) {
1701 eb = path->nodes[level];
1702 new_bytenr = btrfs_node_blockptr(eb,
1703 path->slots[level]);
1704 new_ptr_gen = btrfs_node_ptr_generation(eb,
1705 path->slots[level]);
1711 if (new_bytenr > 0 && new_bytenr == old_bytenr) {
1717 if (new_bytenr == 0 || old_ptr_gen > last_snapshot ||
1718 memcmp_node_keys(parent, slot, path, level)) {
1719 if (level <= lowest_level) {
1724 eb = read_tree_block(dest, old_bytenr, blocksize,
1726 btrfs_tree_lock(eb);
1728 ret = btrfs_cow_block(trans, dest, eb, parent,
1732 btrfs_set_lock_blocking(eb);
1734 btrfs_tree_unlock(parent);
1735 free_extent_buffer(parent);
1742 btrfs_tree_unlock(parent);
1743 free_extent_buffer(parent);
1748 btrfs_node_key_to_cpu(path->nodes[level], &key,
1749 path->slots[level]);
1750 btrfs_release_path(src, path);
1752 path->lowest_level = level;
1753 ret = btrfs_search_slot(trans, src, &key, path, 0, 1);
1754 path->lowest_level = 0;
1758 * swap blocks in fs tree and reloc tree.
1760 btrfs_set_node_blockptr(parent, slot, new_bytenr);
1761 btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen);
1762 btrfs_mark_buffer_dirty(parent);
1764 btrfs_set_node_blockptr(path->nodes[level],
1765 path->slots[level], old_bytenr);
1766 btrfs_set_node_ptr_generation(path->nodes[level],
1767 path->slots[level], old_ptr_gen);
1768 btrfs_mark_buffer_dirty(path->nodes[level]);
1770 ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize,
1771 path->nodes[level]->start,
1772 src->root_key.objectid, level - 1, 0);
1774 ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize,
1775 0, dest->root_key.objectid, level - 1,
1779 ret = btrfs_free_extent(trans, src, new_bytenr, blocksize,
1780 path->nodes[level]->start,
1781 src->root_key.objectid, level - 1, 0);
1784 ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize,
1785 0, dest->root_key.objectid, level - 1,
1789 btrfs_unlock_up_safe(path, 0);
1794 btrfs_tree_unlock(parent);
1795 free_extent_buffer(parent);
1800 * helper to find next relocated block in reloc tree
1802 static noinline_for_stack
1803 int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1806 struct extent_buffer *eb;
1811 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1813 for (i = 0; i < *level; i++) {
1814 free_extent_buffer(path->nodes[i]);
1815 path->nodes[i] = NULL;
1818 for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) {
1819 eb = path->nodes[i];
1820 nritems = btrfs_header_nritems(eb);
1821 while (path->slots[i] + 1 < nritems) {
1823 if (btrfs_node_ptr_generation(eb, path->slots[i]) <=
1830 free_extent_buffer(path->nodes[i]);
1831 path->nodes[i] = NULL;
1837 * walk down reloc tree to find relocated block of lowest level
1839 static noinline_for_stack
1840 int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path,
1843 struct extent_buffer *eb = NULL;
1851 last_snapshot = btrfs_root_last_snapshot(&root->root_item);
1853 for (i = *level; i > 0; i--) {
1854 eb = path->nodes[i];
1855 nritems = btrfs_header_nritems(eb);
1856 while (path->slots[i] < nritems) {
1857 ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]);
1858 if (ptr_gen > last_snapshot)
1862 if (path->slots[i] >= nritems) {
1873 bytenr = btrfs_node_blockptr(eb, path->slots[i]);
1874 blocksize = btrfs_level_size(root, i - 1);
1875 eb = read_tree_block(root, bytenr, blocksize, ptr_gen);
1876 BUG_ON(btrfs_header_level(eb) != i - 1);
1877 path->nodes[i - 1] = eb;
1878 path->slots[i - 1] = 0;
1884 * invalidate extent cache for file extents whose key in range of
1885 * [min_key, max_key)
1887 static int invalidate_extent_cache(struct btrfs_root *root,
1888 struct btrfs_key *min_key,
1889 struct btrfs_key *max_key)
1891 struct inode *inode = NULL;
1895 objectid = min_key->objectid;
1900 if (objectid > max_key->objectid)
1903 inode = find_next_inode(root, objectid);
1907 if (inode->i_ino > max_key->objectid) {
1912 objectid = inode->i_ino + 1;
1913 if (!S_ISREG(inode->i_mode))
1916 if (unlikely(min_key->objectid == inode->i_ino)) {
1917 if (min_key->type > BTRFS_EXTENT_DATA_KEY)
1919 if (min_key->type < BTRFS_EXTENT_DATA_KEY)
1922 start = min_key->offset;
1923 WARN_ON(!IS_ALIGNED(start, root->sectorsize));
1929 if (unlikely(max_key->objectid == inode->i_ino)) {
1930 if (max_key->type < BTRFS_EXTENT_DATA_KEY)
1932 if (max_key->type > BTRFS_EXTENT_DATA_KEY) {
1935 if (max_key->offset == 0)
1937 end = max_key->offset;
1938 WARN_ON(!IS_ALIGNED(end, root->sectorsize));
1945 /* the lock_extent waits for readpage to complete */
1946 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
1947 btrfs_drop_extent_cache(inode, start, end, 1);
1948 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
1953 static int find_next_key(struct btrfs_path *path, int level,
1954 struct btrfs_key *key)
1957 while (level < BTRFS_MAX_LEVEL) {
1958 if (!path->nodes[level])
1960 if (path->slots[level] + 1 <
1961 btrfs_header_nritems(path->nodes[level])) {
1962 btrfs_node_key_to_cpu(path->nodes[level], key,
1963 path->slots[level] + 1);
1972 * merge the relocated tree blocks in reloc tree with corresponding
1975 static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
1976 struct btrfs_root *root)
1978 LIST_HEAD(inode_list);
1979 struct btrfs_key key;
1980 struct btrfs_key next_key;
1981 struct btrfs_trans_handle *trans;
1982 struct btrfs_root *reloc_root;
1983 struct btrfs_root_item *root_item;
1984 struct btrfs_path *path;
1985 struct extent_buffer *leaf;
1994 path = btrfs_alloc_path();
1998 reloc_root = root->reloc_root;
1999 root_item = &reloc_root->root_item;
2001 if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) {
2002 level = btrfs_root_level(root_item);
2003 extent_buffer_get(reloc_root->node);
2004 path->nodes[level] = reloc_root->node;
2005 path->slots[level] = 0;
2007 btrfs_disk_key_to_cpu(&key, &root_item->drop_progress);
2009 level = root_item->drop_level;
2011 path->lowest_level = level;
2012 ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0);
2013 path->lowest_level = 0;
2015 btrfs_free_path(path);
2019 btrfs_node_key_to_cpu(path->nodes[level], &next_key,
2020 path->slots[level]);
2021 WARN_ON(memcmp(&key, &next_key, sizeof(key)));
2023 btrfs_unlock_up_safe(path, 0);
2026 min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2027 memset(&next_key, 0, sizeof(next_key));
2030 trans = btrfs_start_transaction(root, 0);
2031 trans->block_rsv = rc->block_rsv;
2033 ret = btrfs_block_rsv_check(trans, root, rc->block_rsv,
2036 BUG_ON(ret != -EAGAIN);
2037 ret = btrfs_commit_transaction(trans, root);
2045 ret = walk_down_reloc_tree(reloc_root, path, &level);
2053 if (!find_next_key(path, level, &key) &&
2054 btrfs_comp_cpu_keys(&next_key, &key) >= 0) {
2057 ret = replace_path(trans, root, reloc_root, path,
2058 &next_key, level, max_level);
2067 btrfs_node_key_to_cpu(path->nodes[level], &key,
2068 path->slots[level]);
2072 ret = walk_up_reloc_tree(reloc_root, path, &level);
2078 * save the merging progress in the drop_progress.
2079 * this is OK since root refs == 1 in this case.
2081 btrfs_node_key(path->nodes[level], &root_item->drop_progress,
2082 path->slots[level]);
2083 root_item->drop_level = level;
2085 nr = trans->blocks_used;
2086 btrfs_end_transaction_throttle(trans, root);
2088 btrfs_btree_balance_dirty(root, nr);
2090 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2091 invalidate_extent_cache(root, &key, &next_key);
2095 * handle the case only one block in the fs tree need to be
2096 * relocated and the block is tree root.
2098 leaf = btrfs_lock_root_node(root);
2099 ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf);
2100 btrfs_tree_unlock(leaf);
2101 free_extent_buffer(leaf);
2105 btrfs_free_path(path);
2108 memset(&root_item->drop_progress, 0,
2109 sizeof(root_item->drop_progress));
2110 root_item->drop_level = 0;
2111 btrfs_set_root_refs(root_item, 0);
2112 btrfs_update_reloc_root(trans, root);
2115 nr = trans->blocks_used;
2116 btrfs_end_transaction_throttle(trans, root);
2118 btrfs_btree_balance_dirty(root, nr);
2120 if (replaced && rc->stage == UPDATE_DATA_PTRS)
2121 invalidate_extent_cache(root, &key, &next_key);
2126 static noinline_for_stack
2127 int prepare_to_merge(struct reloc_control *rc, int err)
2129 struct btrfs_root *root = rc->extent_root;
2130 struct btrfs_root *reloc_root;
2131 struct btrfs_trans_handle *trans;
2132 LIST_HEAD(reloc_roots);
2136 mutex_lock(&root->fs_info->trans_mutex);
2137 rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2;
2138 rc->merging_rsv_size += rc->nodes_relocated * 2;
2139 mutex_unlock(&root->fs_info->trans_mutex);
2142 num_bytes = rc->merging_rsv_size;
2143 ret = btrfs_block_rsv_add(NULL, root, rc->block_rsv,
2149 trans = btrfs_join_transaction(rc->extent_root, 1);
2150 if (IS_ERR(trans)) {
2152 btrfs_block_rsv_release(rc->extent_root,
2153 rc->block_rsv, num_bytes);
2154 return PTR_ERR(trans);
2158 if (num_bytes != rc->merging_rsv_size) {
2159 btrfs_end_transaction(trans, rc->extent_root);
2160 btrfs_block_rsv_release(rc->extent_root,
2161 rc->block_rsv, num_bytes);
2166 rc->merge_reloc_tree = 1;
2168 while (!list_empty(&rc->reloc_roots)) {
2169 reloc_root = list_entry(rc->reloc_roots.next,
2170 struct btrfs_root, root_list);
2171 list_del_init(&reloc_root->root_list);
2173 root = read_fs_root(reloc_root->fs_info,
2174 reloc_root->root_key.offset);
2175 BUG_ON(IS_ERR(root));
2176 BUG_ON(root->reloc_root != reloc_root);
2179 * set reference count to 1, so btrfs_recover_relocation
2180 * knows it should resumes merging
2183 btrfs_set_root_refs(&reloc_root->root_item, 1);
2184 btrfs_update_reloc_root(trans, root);
2186 list_add(&reloc_root->root_list, &reloc_roots);
2189 list_splice(&reloc_roots, &rc->reloc_roots);
2192 btrfs_commit_transaction(trans, rc->extent_root);
2194 btrfs_end_transaction(trans, rc->extent_root);
2198 static noinline_for_stack
2199 int merge_reloc_roots(struct reloc_control *rc)
2201 struct btrfs_root *root;
2202 struct btrfs_root *reloc_root;
2203 LIST_HEAD(reloc_roots);
2207 root = rc->extent_root;
2208 mutex_lock(&root->fs_info->trans_mutex);
2209 list_splice_init(&rc->reloc_roots, &reloc_roots);
2210 mutex_unlock(&root->fs_info->trans_mutex);
2212 while (!list_empty(&reloc_roots)) {
2214 reloc_root = list_entry(reloc_roots.next,
2215 struct btrfs_root, root_list);
2217 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
2218 root = read_fs_root(reloc_root->fs_info,
2219 reloc_root->root_key.offset);
2220 BUG_ON(IS_ERR(root));
2221 BUG_ON(root->reloc_root != reloc_root);
2223 ret = merge_reloc_root(rc, root);
2226 list_del_init(&reloc_root->root_list);
2228 btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0);
2235 BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root));
2239 static void free_block_list(struct rb_root *blocks)
2241 struct tree_block *block;
2242 struct rb_node *rb_node;
2243 while ((rb_node = rb_first(blocks))) {
2244 block = rb_entry(rb_node, struct tree_block, rb_node);
2245 rb_erase(rb_node, blocks);
2250 static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans,
2251 struct btrfs_root *reloc_root)
2253 struct btrfs_root *root;
2255 if (reloc_root->last_trans == trans->transid)
2258 root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset);
2259 BUG_ON(IS_ERR(root));
2260 BUG_ON(root->reloc_root != reloc_root);
2262 return btrfs_record_root_in_trans(trans, root);
2265 static noinline_for_stack
2266 struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans,
2267 struct reloc_control *rc,
2268 struct backref_node *node,
2269 struct backref_edge *edges[], int *nr)
2271 struct backref_node *next;
2272 struct btrfs_root *root;
2278 next = walk_up_backref(next, edges, &index);
2281 BUG_ON(!root->ref_cows);
2283 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) {
2284 record_reloc_root_in_trans(trans, root);
2288 btrfs_record_root_in_trans(trans, root);
2289 root = root->reloc_root;
2291 if (next->new_bytenr != root->node->start) {
2292 BUG_ON(next->new_bytenr);
2293 BUG_ON(!list_empty(&next->list));
2294 next->new_bytenr = root->node->start;
2296 list_add_tail(&next->list,
2297 &rc->backref_cache.changed);
2298 __mark_block_processed(rc, next);
2304 next = walk_down_backref(edges, &index);
2305 if (!next || next->level <= node->level)
2313 /* setup backref node path for btrfs_reloc_cow_block */
2315 rc->backref_cache.path[next->level] = next;
2318 next = edges[index]->node[UPPER];
2324 * select a tree root for relocation. return NULL if the block
2325 * is reference counted. we should use do_relocation() in this
2326 * case. return a tree root pointer if the block isn't reference
2327 * counted. return -ENOENT if the block is root of reloc tree.
2329 static noinline_for_stack
2330 struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans,
2331 struct backref_node *node)
2333 struct backref_node *next;
2334 struct btrfs_root *root;
2335 struct btrfs_root *fs_root = NULL;
2336 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2342 next = walk_up_backref(next, edges, &index);
2346 /* no other choice for non-refernce counted tree */
2347 if (!root->ref_cows)
2350 if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID)
2356 next = walk_down_backref(edges, &index);
2357 if (!next || next->level <= node->level)
2362 return ERR_PTR(-ENOENT);
2366 static noinline_for_stack
2367 u64 calcu_metadata_size(struct reloc_control *rc,
2368 struct backref_node *node, int reserve)
2370 struct backref_node *next = node;
2371 struct backref_edge *edge;
2372 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2376 BUG_ON(reserve && node->processed);
2381 if (next->processed && (reserve || next != node))
2384 num_bytes += btrfs_level_size(rc->extent_root,
2387 if (list_empty(&next->upper))
2390 edge = list_entry(next->upper.next,
2391 struct backref_edge, list[LOWER]);
2392 edges[index++] = edge;
2393 next = edge->node[UPPER];
2395 next = walk_down_backref(edges, &index);
2400 static int reserve_metadata_space(struct btrfs_trans_handle *trans,
2401 struct reloc_control *rc,
2402 struct backref_node *node)
2404 struct btrfs_root *root = rc->extent_root;
2408 num_bytes = calcu_metadata_size(rc, node, 1) * 2;
2410 trans->block_rsv = rc->block_rsv;
2411 ret = btrfs_block_rsv_add(trans, root, rc->block_rsv, num_bytes);
2414 rc->commit_transaction = 1;
2421 static void release_metadata_space(struct reloc_control *rc,
2422 struct backref_node *node)
2424 u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2;
2425 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes);
2429 * relocate a block tree, and then update pointers in upper level
2430 * blocks that reference the block to point to the new location.
2432 * if called by link_to_upper, the block has already been relocated.
2433 * in that case this function just updates pointers.
2435 static int do_relocation(struct btrfs_trans_handle *trans,
2436 struct reloc_control *rc,
2437 struct backref_node *node,
2438 struct btrfs_key *key,
2439 struct btrfs_path *path, int lowest)
2441 struct backref_node *upper;
2442 struct backref_edge *edge;
2443 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2444 struct btrfs_root *root;
2445 struct extent_buffer *eb;
2454 BUG_ON(lowest && node->eb);
2456 path->lowest_level = node->level + 1;
2457 rc->backref_cache.path[node->level] = node;
2458 list_for_each_entry(edge, &node->upper, list[LOWER]) {
2461 upper = edge->node[UPPER];
2462 root = select_reloc_root(trans, rc, upper, edges, &nr);
2465 if (upper->eb && !upper->locked) {
2467 ret = btrfs_bin_search(upper->eb, key,
2468 upper->level, &slot);
2470 bytenr = btrfs_node_blockptr(upper->eb, slot);
2471 if (node->eb->start == bytenr)
2474 drop_node_buffer(upper);
2478 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2486 upper->eb = path->nodes[upper->level];
2487 path->nodes[upper->level] = NULL;
2489 BUG_ON(upper->eb != path->nodes[upper->level]);
2493 path->locks[upper->level] = 0;
2495 slot = path->slots[upper->level];
2496 btrfs_release_path(NULL, path);
2498 ret = btrfs_bin_search(upper->eb, key, upper->level,
2503 bytenr = btrfs_node_blockptr(upper->eb, slot);
2505 BUG_ON(bytenr != node->bytenr);
2507 if (node->eb->start == bytenr)
2511 blocksize = btrfs_level_size(root, node->level);
2512 generation = btrfs_node_ptr_generation(upper->eb, slot);
2513 eb = read_tree_block(root, bytenr, blocksize, generation);
2514 btrfs_tree_lock(eb);
2515 btrfs_set_lock_blocking(eb);
2518 ret = btrfs_cow_block(trans, root, eb, upper->eb,
2520 btrfs_tree_unlock(eb);
2521 free_extent_buffer(eb);
2526 BUG_ON(node->eb != eb);
2528 btrfs_set_node_blockptr(upper->eb, slot,
2530 btrfs_set_node_ptr_generation(upper->eb, slot,
2532 btrfs_mark_buffer_dirty(upper->eb);
2534 ret = btrfs_inc_extent_ref(trans, root,
2535 node->eb->start, blocksize,
2537 btrfs_header_owner(upper->eb),
2541 ret = btrfs_drop_subtree(trans, root, eb, upper->eb);
2545 if (!upper->pending)
2546 drop_node_buffer(upper);
2548 unlock_node_buffer(upper);
2553 if (!err && node->pending) {
2554 drop_node_buffer(node);
2555 list_move_tail(&node->list, &rc->backref_cache.changed);
2559 path->lowest_level = 0;
2560 BUG_ON(err == -ENOSPC);
2564 static int link_to_upper(struct btrfs_trans_handle *trans,
2565 struct reloc_control *rc,
2566 struct backref_node *node,
2567 struct btrfs_path *path)
2569 struct btrfs_key key;
2571 btrfs_node_key_to_cpu(node->eb, &key, 0);
2572 return do_relocation(trans, rc, node, &key, path, 0);
2575 static int finish_pending_nodes(struct btrfs_trans_handle *trans,
2576 struct reloc_control *rc,
2577 struct btrfs_path *path, int err)
2580 struct backref_cache *cache = &rc->backref_cache;
2581 struct backref_node *node;
2585 for (level = 0; level < BTRFS_MAX_LEVEL; level++) {
2586 while (!list_empty(&cache->pending[level])) {
2587 node = list_entry(cache->pending[level].next,
2588 struct backref_node, list);
2589 list_move_tail(&node->list, &list);
2590 BUG_ON(!node->pending);
2593 ret = link_to_upper(trans, rc, node, path);
2598 list_splice_init(&list, &cache->pending[level]);
2603 static void mark_block_processed(struct reloc_control *rc,
2604 u64 bytenr, u32 blocksize)
2606 set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1,
2607 EXTENT_DIRTY, GFP_NOFS);
2610 static void __mark_block_processed(struct reloc_control *rc,
2611 struct backref_node *node)
2614 if (node->level == 0 ||
2615 in_block_group(node->bytenr, rc->block_group)) {
2616 blocksize = btrfs_level_size(rc->extent_root, node->level);
2617 mark_block_processed(rc, node->bytenr, blocksize);
2619 node->processed = 1;
2623 * mark a block and all blocks directly/indirectly reference the block
2626 static void update_processed_blocks(struct reloc_control *rc,
2627 struct backref_node *node)
2629 struct backref_node *next = node;
2630 struct backref_edge *edge;
2631 struct backref_edge *edges[BTRFS_MAX_LEVEL - 1];
2637 if (next->processed)
2640 __mark_block_processed(rc, next);
2642 if (list_empty(&next->upper))
2645 edge = list_entry(next->upper.next,
2646 struct backref_edge, list[LOWER]);
2647 edges[index++] = edge;
2648 next = edge->node[UPPER];
2650 next = walk_down_backref(edges, &index);
2654 static int tree_block_processed(u64 bytenr, u32 blocksize,
2655 struct reloc_control *rc)
2657 if (test_range_bit(&rc->processed_blocks, bytenr,
2658 bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL))
2663 static int get_tree_block_key(struct reloc_control *rc,
2664 struct tree_block *block)
2666 struct extent_buffer *eb;
2668 BUG_ON(block->key_ready);
2669 eb = read_tree_block(rc->extent_root, block->bytenr,
2670 block->key.objectid, block->key.offset);
2671 WARN_ON(btrfs_header_level(eb) != block->level);
2672 if (block->level == 0)
2673 btrfs_item_key_to_cpu(eb, &block->key, 0);
2675 btrfs_node_key_to_cpu(eb, &block->key, 0);
2676 free_extent_buffer(eb);
2677 block->key_ready = 1;
2681 static int reada_tree_block(struct reloc_control *rc,
2682 struct tree_block *block)
2684 BUG_ON(block->key_ready);
2685 readahead_tree_block(rc->extent_root, block->bytenr,
2686 block->key.objectid, block->key.offset);
2691 * helper function to relocate a tree block
2693 static int relocate_tree_block(struct btrfs_trans_handle *trans,
2694 struct reloc_control *rc,
2695 struct backref_node *node,
2696 struct btrfs_key *key,
2697 struct btrfs_path *path)
2699 struct btrfs_root *root;
2706 BUG_ON(node->processed);
2707 root = select_one_root(trans, node);
2708 if (root == ERR_PTR(-ENOENT)) {
2709 update_processed_blocks(rc, node);
2713 if (!root || root->ref_cows) {
2714 ret = reserve_metadata_space(trans, rc, node);
2721 if (root->ref_cows) {
2722 BUG_ON(node->new_bytenr);
2723 BUG_ON(!list_empty(&node->list));
2724 btrfs_record_root_in_trans(trans, root);
2725 root = root->reloc_root;
2726 node->new_bytenr = root->node->start;
2728 list_add_tail(&node->list, &rc->backref_cache.changed);
2730 path->lowest_level = node->level;
2731 ret = btrfs_search_slot(trans, root, key, path, 0, 1);
2732 btrfs_release_path(root, path);
2737 update_processed_blocks(rc, node);
2739 ret = do_relocation(trans, rc, node, key, path, 1);
2742 if (ret || node->level == 0 || node->cowonly) {
2744 release_metadata_space(rc, node);
2745 remove_backref_node(&rc->backref_cache, node);
2751 * relocate a list of blocks
2753 static noinline_for_stack
2754 int relocate_tree_blocks(struct btrfs_trans_handle *trans,
2755 struct reloc_control *rc, struct rb_root *blocks)
2757 struct backref_node *node;
2758 struct btrfs_path *path;
2759 struct tree_block *block;
2760 struct rb_node *rb_node;
2764 path = btrfs_alloc_path();
2768 rb_node = rb_first(blocks);
2770 block = rb_entry(rb_node, struct tree_block, rb_node);
2771 if (!block->key_ready)
2772 reada_tree_block(rc, block);
2773 rb_node = rb_next(rb_node);
2776 rb_node = rb_first(blocks);
2778 block = rb_entry(rb_node, struct tree_block, rb_node);
2779 if (!block->key_ready)
2780 get_tree_block_key(rc, block);
2781 rb_node = rb_next(rb_node);
2784 rb_node = rb_first(blocks);
2786 block = rb_entry(rb_node, struct tree_block, rb_node);
2788 node = build_backref_tree(rc, &block->key,
2789 block->level, block->bytenr);
2791 err = PTR_ERR(node);
2795 ret = relocate_tree_block(trans, rc, node, &block->key,
2798 if (ret != -EAGAIN || rb_node == rb_first(blocks))
2802 rb_node = rb_next(rb_node);
2805 free_block_list(blocks);
2806 err = finish_pending_nodes(trans, rc, path, err);
2808 btrfs_free_path(path);
2812 static noinline_for_stack
2813 int prealloc_file_extent_cluster(struct inode *inode,
2814 struct file_extent_cluster *cluster)
2819 u64 offset = BTRFS_I(inode)->index_cnt;
2824 BUG_ON(cluster->start != cluster->boundary[0]);
2825 mutex_lock(&inode->i_mutex);
2827 ret = btrfs_check_data_free_space(inode, cluster->end +
2828 1 - cluster->start);
2832 while (nr < cluster->nr) {
2833 start = cluster->boundary[nr] - offset;
2834 if (nr + 1 < cluster->nr)
2835 end = cluster->boundary[nr + 1] - 1 - offset;
2837 end = cluster->end - offset;
2839 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2840 num_bytes = end + 1 - start;
2841 ret = btrfs_prealloc_file_range(inode, 0, start,
2842 num_bytes, num_bytes,
2843 end + 1, &alloc_hint);
2844 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2849 btrfs_free_reserved_data_space(inode, cluster->end +
2850 1 - cluster->start);
2852 mutex_unlock(&inode->i_mutex);
2856 static noinline_for_stack
2857 int setup_extent_mapping(struct inode *inode, u64 start, u64 end,
2860 struct btrfs_root *root = BTRFS_I(inode)->root;
2861 struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree;
2862 struct extent_map *em;
2865 em = alloc_extent_map(GFP_NOFS);
2870 em->len = end + 1 - start;
2871 em->block_len = em->len;
2872 em->block_start = block_start;
2873 em->bdev = root->fs_info->fs_devices->latest_bdev;
2874 set_bit(EXTENT_FLAG_PINNED, &em->flags);
2876 lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2878 write_lock(&em_tree->lock);
2879 ret = add_extent_mapping(em_tree, em);
2880 write_unlock(&em_tree->lock);
2881 if (ret != -EEXIST) {
2882 free_extent_map(em);
2885 btrfs_drop_extent_cache(inode, start, end, 0);
2887 unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS);
2891 static int relocate_file_extent_cluster(struct inode *inode,
2892 struct file_extent_cluster *cluster)
2896 u64 offset = BTRFS_I(inode)->index_cnt;
2897 unsigned long index;
2898 unsigned long last_index;
2900 struct file_ra_state *ra;
2907 ra = kzalloc(sizeof(*ra), GFP_NOFS);
2911 ret = prealloc_file_extent_cluster(inode, cluster);
2915 file_ra_state_init(ra, inode->i_mapping);
2917 ret = setup_extent_mapping(inode, cluster->start - offset,
2918 cluster->end - offset, cluster->start);
2922 index = (cluster->start - offset) >> PAGE_CACHE_SHIFT;
2923 last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT;
2924 while (index <= last_index) {
2925 ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE);
2929 page = find_lock_page(inode->i_mapping, index);
2931 page_cache_sync_readahead(inode->i_mapping,
2933 last_index + 1 - index);
2934 page = grab_cache_page(inode->i_mapping, index);
2936 btrfs_delalloc_release_metadata(inode,
2943 if (PageReadahead(page)) {
2944 page_cache_async_readahead(inode->i_mapping,
2945 ra, NULL, page, index,
2946 last_index + 1 - index);
2949 if (!PageUptodate(page)) {
2950 btrfs_readpage(NULL, page);
2952 if (!PageUptodate(page)) {
2954 page_cache_release(page);
2955 btrfs_delalloc_release_metadata(inode,
2962 page_start = (u64)page->index << PAGE_CACHE_SHIFT;
2963 page_end = page_start + PAGE_CACHE_SIZE - 1;
2965 lock_extent(&BTRFS_I(inode)->io_tree,
2966 page_start, page_end, GFP_NOFS);
2968 set_page_extent_mapped(page);
2970 if (nr < cluster->nr &&
2971 page_start + offset == cluster->boundary[nr]) {
2972 set_extent_bits(&BTRFS_I(inode)->io_tree,
2973 page_start, page_end,
2974 EXTENT_BOUNDARY, GFP_NOFS);
2978 btrfs_set_extent_delalloc(inode, page_start, page_end, NULL);
2979 set_page_dirty(page);
2981 unlock_extent(&BTRFS_I(inode)->io_tree,
2982 page_start, page_end, GFP_NOFS);
2984 page_cache_release(page);
2987 balance_dirty_pages_ratelimited(inode->i_mapping);
2988 btrfs_throttle(BTRFS_I(inode)->root);
2990 WARN_ON(nr != cluster->nr);
2996 static noinline_for_stack
2997 int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key,
2998 struct file_extent_cluster *cluster)
3002 if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) {
3003 ret = relocate_file_extent_cluster(inode, cluster);
3010 cluster->start = extent_key->objectid;
3012 BUG_ON(cluster->nr >= MAX_EXTENTS);
3013 cluster->end = extent_key->objectid + extent_key->offset - 1;
3014 cluster->boundary[cluster->nr] = extent_key->objectid;
3017 if (cluster->nr >= MAX_EXTENTS) {
3018 ret = relocate_file_extent_cluster(inode, cluster);
3026 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3027 static int get_ref_objectid_v0(struct reloc_control *rc,
3028 struct btrfs_path *path,
3029 struct btrfs_key *extent_key,
3030 u64 *ref_objectid, int *path_change)
3032 struct btrfs_key key;
3033 struct extent_buffer *leaf;
3034 struct btrfs_extent_ref_v0 *ref0;
3038 leaf = path->nodes[0];
3039 slot = path->slots[0];
3041 if (slot >= btrfs_header_nritems(leaf)) {
3042 ret = btrfs_next_leaf(rc->extent_root, path);
3046 leaf = path->nodes[0];
3047 slot = path->slots[0];
3051 btrfs_item_key_to_cpu(leaf, &key, slot);
3052 if (key.objectid != extent_key->objectid)
3055 if (key.type != BTRFS_EXTENT_REF_V0_KEY) {
3059 ref0 = btrfs_item_ptr(leaf, slot,
3060 struct btrfs_extent_ref_v0);
3061 *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0);
3069 * helper to add a tree block to the list.
3070 * the major work is getting the generation and level of the block
3072 static int add_tree_block(struct reloc_control *rc,
3073 struct btrfs_key *extent_key,
3074 struct btrfs_path *path,
3075 struct rb_root *blocks)
3077 struct extent_buffer *eb;
3078 struct btrfs_extent_item *ei;
3079 struct btrfs_tree_block_info *bi;
3080 struct tree_block *block;
3081 struct rb_node *rb_node;
3086 eb = path->nodes[0];
3087 item_size = btrfs_item_size_nr(eb, path->slots[0]);
3089 if (item_size >= sizeof(*ei) + sizeof(*bi)) {
3090 ei = btrfs_item_ptr(eb, path->slots[0],
3091 struct btrfs_extent_item);
3092 bi = (struct btrfs_tree_block_info *)(ei + 1);
3093 generation = btrfs_extent_generation(eb, ei);
3094 level = btrfs_tree_block_level(eb, bi);
3096 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3100 BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0));
3101 ret = get_ref_objectid_v0(rc, path, extent_key,
3105 BUG_ON(ref_owner >= BTRFS_MAX_LEVEL);
3106 level = (int)ref_owner;
3107 /* FIXME: get real generation */
3114 btrfs_release_path(rc->extent_root, path);
3116 BUG_ON(level == -1);
3118 block = kmalloc(sizeof(*block), GFP_NOFS);
3122 block->bytenr = extent_key->objectid;
3123 block->key.objectid = extent_key->offset;
3124 block->key.offset = generation;
3125 block->level = level;
3126 block->key_ready = 0;
3128 rb_node = tree_insert(blocks, block->bytenr, &block->rb_node);
3135 * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY
3137 static int __add_tree_block(struct reloc_control *rc,
3138 u64 bytenr, u32 blocksize,
3139 struct rb_root *blocks)
3141 struct btrfs_path *path;
3142 struct btrfs_key key;
3145 if (tree_block_processed(bytenr, blocksize, rc))
3148 if (tree_search(blocks, bytenr))
3151 path = btrfs_alloc_path();
3155 key.objectid = bytenr;
3156 key.type = BTRFS_EXTENT_ITEM_KEY;
3157 key.offset = blocksize;
3159 path->search_commit_root = 1;
3160 path->skip_locking = 1;
3161 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0);
3166 btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
3167 ret = add_tree_block(rc, &key, path, blocks);
3169 btrfs_free_path(path);
3174 * helper to check if the block use full backrefs for pointers in it
3176 static int block_use_full_backref(struct reloc_control *rc,
3177 struct extent_buffer *eb)
3182 if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) ||
3183 btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV)
3186 ret = btrfs_lookup_extent_info(NULL, rc->extent_root,
3187 eb->start, eb->len, NULL, &flags);
3190 if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)
3197 static int delete_block_group_cache(struct btrfs_fs_info *fs_info,
3198 struct inode *inode, u64 ino)
3200 struct btrfs_key key;
3201 struct btrfs_path *path;
3202 struct btrfs_root *root = fs_info->tree_root;
3203 struct btrfs_trans_handle *trans;
3211 key.type = BTRFS_INODE_ITEM_KEY;
3214 inode = btrfs_iget(fs_info->sb, &key, root, NULL);
3215 if (!inode || IS_ERR(inode) || is_bad_inode(inode)) {
3216 if (inode && !IS_ERR(inode))
3222 path = btrfs_alloc_path();
3228 trans = btrfs_join_transaction(root, 0);
3229 if (IS_ERR(trans)) {
3230 btrfs_free_path(path);
3231 ret = PTR_ERR(trans);
3235 ret = btrfs_truncate_free_space_cache(root, trans, path, inode);
3237 btrfs_free_path(path);
3238 nr = trans->blocks_used;
3239 btrfs_end_transaction(trans, root);
3240 btrfs_btree_balance_dirty(root, nr);
3247 * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY
3248 * this function scans fs tree to find blocks reference the data extent
3250 static int find_data_references(struct reloc_control *rc,
3251 struct btrfs_key *extent_key,
3252 struct extent_buffer *leaf,
3253 struct btrfs_extent_data_ref *ref,
3254 struct rb_root *blocks)
3256 struct btrfs_path *path;
3257 struct tree_block *block;
3258 struct btrfs_root *root;
3259 struct btrfs_file_extent_item *fi;
3260 struct rb_node *rb_node;
3261 struct btrfs_key key;
3272 ref_root = btrfs_extent_data_ref_root(leaf, ref);
3273 ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref);
3274 ref_offset = btrfs_extent_data_ref_offset(leaf, ref);
3275 ref_count = btrfs_extent_data_ref_count(leaf, ref);
3278 * This is an extent belonging to the free space cache, lets just delete
3279 * it and redo the search.
3281 if (ref_root == BTRFS_ROOT_TREE_OBJECTID) {
3282 ret = delete_block_group_cache(rc->extent_root->fs_info,
3283 NULL, ref_objectid);
3289 path = btrfs_alloc_path();
3293 root = read_fs_root(rc->extent_root->fs_info, ref_root);
3295 err = PTR_ERR(root);
3299 key.objectid = ref_objectid;
3300 key.offset = ref_offset;
3301 key.type = BTRFS_EXTENT_DATA_KEY;
3303 path->search_commit_root = 1;
3304 path->skip_locking = 1;
3305 ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
3311 leaf = path->nodes[0];
3312 nritems = btrfs_header_nritems(leaf);
3314 * the references in tree blocks that use full backrefs
3315 * are not counted in
3317 if (block_use_full_backref(rc, leaf))
3321 rb_node = tree_search(blocks, leaf->start);
3326 path->slots[0] = nritems;
3329 while (ref_count > 0) {
3330 while (path->slots[0] >= nritems) {
3331 ret = btrfs_next_leaf(root, path);
3341 leaf = path->nodes[0];
3342 nritems = btrfs_header_nritems(leaf);
3345 if (block_use_full_backref(rc, leaf))
3349 rb_node = tree_search(blocks, leaf->start);
3354 path->slots[0] = nritems;
3358 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3359 if (key.objectid != ref_objectid ||
3360 key.type != BTRFS_EXTENT_DATA_KEY) {
3365 fi = btrfs_item_ptr(leaf, path->slots[0],
3366 struct btrfs_file_extent_item);
3368 if (btrfs_file_extent_type(leaf, fi) ==
3369 BTRFS_FILE_EXTENT_INLINE)
3372 if (btrfs_file_extent_disk_bytenr(leaf, fi) !=
3373 extent_key->objectid)
3376 key.offset -= btrfs_file_extent_offset(leaf, fi);
3377 if (key.offset != ref_offset)
3385 if (!tree_block_processed(leaf->start, leaf->len, rc)) {
3386 block = kmalloc(sizeof(*block), GFP_NOFS);
3391 block->bytenr = leaf->start;
3392 btrfs_item_key_to_cpu(leaf, &block->key, 0);
3394 block->key_ready = 1;
3395 rb_node = tree_insert(blocks, block->bytenr,
3402 path->slots[0] = nritems;
3408 btrfs_free_path(path);
3413 * hepler to find all tree blocks that reference a given data extent
3415 static noinline_for_stack
3416 int add_data_references(struct reloc_control *rc,
3417 struct btrfs_key *extent_key,
3418 struct btrfs_path *path,
3419 struct rb_root *blocks)
3421 struct btrfs_key key;
3422 struct extent_buffer *eb;
3423 struct btrfs_extent_data_ref *dref;
3424 struct btrfs_extent_inline_ref *iref;
3427 u32 blocksize = btrfs_level_size(rc->extent_root, 0);
3431 eb = path->nodes[0];
3432 ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
3433 end = ptr + btrfs_item_size_nr(eb, path->slots[0]);
3434 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3435 if (ptr + sizeof(struct btrfs_extent_item_v0) == end)
3439 ptr += sizeof(struct btrfs_extent_item);
3442 iref = (struct btrfs_extent_inline_ref *)ptr;
3443 key.type = btrfs_extent_inline_ref_type(eb, iref);
3444 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3445 key.offset = btrfs_extent_inline_ref_offset(eb, iref);
3446 ret = __add_tree_block(rc, key.offset, blocksize,
3448 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3449 dref = (struct btrfs_extent_data_ref *)(&iref->offset);
3450 ret = find_data_references(rc, extent_key,
3455 ptr += btrfs_extent_inline_ref_size(key.type);
3461 eb = path->nodes[0];
3462 if (path->slots[0] >= btrfs_header_nritems(eb)) {
3463 ret = btrfs_next_leaf(rc->extent_root, path);
3470 eb = path->nodes[0];
3473 btrfs_item_key_to_cpu(eb, &key, path->slots[0]);
3474 if (key.objectid != extent_key->objectid)
3477 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3478 if (key.type == BTRFS_SHARED_DATA_REF_KEY ||
3479 key.type == BTRFS_EXTENT_REF_V0_KEY) {
3481 BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY);
3482 if (key.type == BTRFS_SHARED_DATA_REF_KEY) {
3484 ret = __add_tree_block(rc, key.offset, blocksize,
3486 } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) {
3487 dref = btrfs_item_ptr(eb, path->slots[0],
3488 struct btrfs_extent_data_ref);
3489 ret = find_data_references(rc, extent_key,
3500 btrfs_release_path(rc->extent_root, path);
3502 free_block_list(blocks);
3507 * hepler to find next unprocessed extent
3509 static noinline_for_stack
3510 int find_next_extent(struct btrfs_trans_handle *trans,
3511 struct reloc_control *rc, struct btrfs_path *path,
3512 struct btrfs_key *extent_key)
3514 struct btrfs_key key;
3515 struct extent_buffer *leaf;
3516 u64 start, end, last;
3519 last = rc->block_group->key.objectid + rc->block_group->key.offset;
3522 if (rc->search_start >= last) {
3527 key.objectid = rc->search_start;
3528 key.type = BTRFS_EXTENT_ITEM_KEY;
3531 path->search_commit_root = 1;
3532 path->skip_locking = 1;
3533 ret = btrfs_search_slot(NULL, rc->extent_root, &key, path,
3538 leaf = path->nodes[0];
3539 if (path->slots[0] >= btrfs_header_nritems(leaf)) {
3540 ret = btrfs_next_leaf(rc->extent_root, path);
3543 leaf = path->nodes[0];
3546 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
3547 if (key.objectid >= last) {
3552 if (key.type != BTRFS_EXTENT_ITEM_KEY ||
3553 key.objectid + key.offset <= rc->search_start) {
3558 ret = find_first_extent_bit(&rc->processed_blocks,
3559 key.objectid, &start, &end,
3562 if (ret == 0 && start <= key.objectid) {
3563 btrfs_release_path(rc->extent_root, path);
3564 rc->search_start = end + 1;
3566 rc->search_start = key.objectid + key.offset;
3567 memcpy(extent_key, &key, sizeof(key));
3571 btrfs_release_path(rc->extent_root, path);
3575 static void set_reloc_control(struct reloc_control *rc)
3577 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3578 mutex_lock(&fs_info->trans_mutex);
3579 fs_info->reloc_ctl = rc;
3580 mutex_unlock(&fs_info->trans_mutex);
3583 static void unset_reloc_control(struct reloc_control *rc)
3585 struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
3586 mutex_lock(&fs_info->trans_mutex);
3587 fs_info->reloc_ctl = NULL;
3588 mutex_unlock(&fs_info->trans_mutex);
3591 static int check_extent_flags(u64 flags)
3593 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3594 (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3596 if (!(flags & BTRFS_EXTENT_FLAG_DATA) &&
3597 !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK))
3599 if ((flags & BTRFS_EXTENT_FLAG_DATA) &&
3600 (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF))
3605 static noinline_for_stack
3606 int prepare_to_relocate(struct reloc_control *rc)
3608 struct btrfs_trans_handle *trans;
3611 rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root);
3616 * reserve some space for creating reloc trees.
3617 * btrfs_init_reloc_root will use them when there
3618 * is no reservation in transaction handle.
3620 ret = btrfs_block_rsv_add(NULL, rc->extent_root, rc->block_rsv,
3621 rc->extent_root->nodesize * 256);
3625 rc->block_rsv->refill_used = 1;
3626 btrfs_add_durable_block_rsv(rc->extent_root->fs_info, rc->block_rsv);
3628 memset(&rc->cluster, 0, sizeof(rc->cluster));
3629 rc->search_start = rc->block_group->key.objectid;
3630 rc->extents_found = 0;
3631 rc->nodes_relocated = 0;
3632 rc->merging_rsv_size = 0;
3634 rc->create_reloc_tree = 1;
3635 set_reloc_control(rc);
3637 trans = btrfs_join_transaction(rc->extent_root, 1);
3638 BUG_ON(IS_ERR(trans));
3639 btrfs_commit_transaction(trans, rc->extent_root);
3643 static noinline_for_stack int relocate_block_group(struct reloc_control *rc)
3645 struct rb_root blocks = RB_ROOT;
3646 struct btrfs_key key;
3647 struct btrfs_trans_handle *trans = NULL;
3648 struct btrfs_path *path;
3649 struct btrfs_extent_item *ei;
3656 path = btrfs_alloc_path();
3660 ret = prepare_to_relocate(rc);
3667 trans = btrfs_start_transaction(rc->extent_root, 0);
3669 if (update_backref_cache(trans, &rc->backref_cache)) {
3670 btrfs_end_transaction(trans, rc->extent_root);
3674 ret = find_next_extent(trans, rc, path, &key);
3680 rc->extents_found++;
3682 ei = btrfs_item_ptr(path->nodes[0], path->slots[0],
3683 struct btrfs_extent_item);
3684 item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]);
3685 if (item_size >= sizeof(*ei)) {
3686 flags = btrfs_extent_flags(path->nodes[0], ei);
3687 ret = check_extent_flags(flags);
3691 #ifdef BTRFS_COMPAT_EXTENT_TREE_V0
3693 int path_change = 0;
3696 sizeof(struct btrfs_extent_item_v0));
3697 ret = get_ref_objectid_v0(rc, path, &key, &ref_owner,
3699 if (ref_owner < BTRFS_FIRST_FREE_OBJECTID)
3700 flags = BTRFS_EXTENT_FLAG_TREE_BLOCK;
3702 flags = BTRFS_EXTENT_FLAG_DATA;
3705 btrfs_release_path(rc->extent_root, path);
3707 path->search_commit_root = 1;
3708 path->skip_locking = 1;
3709 ret = btrfs_search_slot(NULL, rc->extent_root,
3722 if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
3723 ret = add_tree_block(rc, &key, path, &blocks);
3724 } else if (rc->stage == UPDATE_DATA_PTRS &&
3725 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3726 ret = add_data_references(rc, &key, path, &blocks);
3728 btrfs_release_path(rc->extent_root, path);
3736 if (!RB_EMPTY_ROOT(&blocks)) {
3737 ret = relocate_tree_blocks(trans, rc, &blocks);
3739 if (ret != -EAGAIN) {
3743 rc->extents_found--;
3744 rc->search_start = key.objectid;
3748 ret = btrfs_block_rsv_check(trans, rc->extent_root,
3749 rc->block_rsv, 0, 5);
3751 if (ret != -EAGAIN) {
3756 rc->commit_transaction = 1;
3759 if (rc->commit_transaction) {
3760 rc->commit_transaction = 0;
3761 ret = btrfs_commit_transaction(trans, rc->extent_root);
3764 nr = trans->blocks_used;
3765 btrfs_end_transaction_throttle(trans, rc->extent_root);
3766 btrfs_btree_balance_dirty(rc->extent_root, nr);
3770 if (rc->stage == MOVE_DATA_EXTENTS &&
3771 (flags & BTRFS_EXTENT_FLAG_DATA)) {
3772 rc->found_file_extent = 1;
3773 ret = relocate_data_extent(rc->data_inode,
3774 &key, &rc->cluster);
3782 btrfs_release_path(rc->extent_root, path);
3783 clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY,
3787 nr = trans->blocks_used;
3788 btrfs_end_transaction_throttle(trans, rc->extent_root);
3789 btrfs_btree_balance_dirty(rc->extent_root, nr);
3793 ret = relocate_file_extent_cluster(rc->data_inode,
3799 rc->create_reloc_tree = 0;
3800 set_reloc_control(rc);
3802 backref_cache_cleanup(&rc->backref_cache);
3803 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3805 err = prepare_to_merge(rc, err);
3807 merge_reloc_roots(rc);
3809 rc->merge_reloc_tree = 0;
3810 unset_reloc_control(rc);
3811 btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1);
3813 /* get rid of pinned extents */
3814 trans = btrfs_join_transaction(rc->extent_root, 1);
3816 err = PTR_ERR(trans);
3818 btrfs_commit_transaction(trans, rc->extent_root);
3820 btrfs_free_block_rsv(rc->extent_root, rc->block_rsv);
3821 btrfs_free_path(path);
3825 static int __insert_orphan_inode(struct btrfs_trans_handle *trans,
3826 struct btrfs_root *root, u64 objectid)
3828 struct btrfs_path *path;
3829 struct btrfs_inode_item *item;
3830 struct extent_buffer *leaf;
3833 path = btrfs_alloc_path();
3837 ret = btrfs_insert_empty_inode(trans, root, path, objectid);
3841 leaf = path->nodes[0];
3842 item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item);
3843 memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item));
3844 btrfs_set_inode_generation(leaf, item, 1);
3845 btrfs_set_inode_size(leaf, item, 0);
3846 btrfs_set_inode_mode(leaf, item, S_IFREG | 0600);
3847 btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS |
3848 BTRFS_INODE_PREALLOC);
3849 btrfs_mark_buffer_dirty(leaf);
3850 btrfs_release_path(root, path);
3852 btrfs_free_path(path);
3857 * helper to create inode for data relocation.
3858 * the inode is in data relocation tree and its link count is 0
3860 static noinline_for_stack
3861 struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info,
3862 struct btrfs_block_group_cache *group)
3864 struct inode *inode = NULL;
3865 struct btrfs_trans_handle *trans;
3866 struct btrfs_root *root;
3867 struct btrfs_key key;
3869 u64 objectid = BTRFS_FIRST_FREE_OBJECTID;
3872 root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID);
3874 return ERR_CAST(root);
3876 trans = btrfs_start_transaction(root, 6);
3878 return ERR_CAST(trans);
3880 err = btrfs_find_free_objectid(trans, root, objectid, &objectid);
3884 err = __insert_orphan_inode(trans, root, objectid);
3887 key.objectid = objectid;
3888 key.type = BTRFS_INODE_ITEM_KEY;
3890 inode = btrfs_iget(root->fs_info->sb, &key, root, NULL);
3891 BUG_ON(IS_ERR(inode) || is_bad_inode(inode));
3892 BTRFS_I(inode)->index_cnt = group->key.objectid;
3894 err = btrfs_orphan_add(trans, inode);
3896 nr = trans->blocks_used;
3897 btrfs_end_transaction(trans, root);
3898 btrfs_btree_balance_dirty(root, nr);
3902 inode = ERR_PTR(err);
3907 static struct reloc_control *alloc_reloc_control(void)
3909 struct reloc_control *rc;
3911 rc = kzalloc(sizeof(*rc), GFP_NOFS);
3915 INIT_LIST_HEAD(&rc->reloc_roots);
3916 backref_cache_init(&rc->backref_cache);
3917 mapping_tree_init(&rc->reloc_root_tree);
3918 extent_io_tree_init(&rc->processed_blocks, NULL, GFP_NOFS);
3923 * function to relocate all extents in a block group.
3925 int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start)
3927 struct btrfs_fs_info *fs_info = extent_root->fs_info;
3928 struct reloc_control *rc;
3929 struct inode *inode;
3930 struct btrfs_path *path;
3935 rc = alloc_reloc_control();
3939 rc->extent_root = extent_root;
3941 rc->block_group = btrfs_lookup_block_group(fs_info, group_start);
3942 BUG_ON(!rc->block_group);
3944 if (!rc->block_group->ro) {
3945 ret = btrfs_set_block_group_ro(extent_root, rc->block_group);
3953 path = btrfs_alloc_path();
3959 inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group,
3961 btrfs_free_path(path);
3964 ret = delete_block_group_cache(fs_info, inode, 0);
3966 ret = PTR_ERR(inode);
3968 if (ret && ret != -ENOENT) {
3973 rc->data_inode = create_reloc_inode(fs_info, rc->block_group);
3974 if (IS_ERR(rc->data_inode)) {
3975 err = PTR_ERR(rc->data_inode);
3976 rc->data_inode = NULL;
3980 printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n",
3981 (unsigned long long)rc->block_group->key.objectid,
3982 (unsigned long long)rc->block_group->flags);
3984 btrfs_start_delalloc_inodes(fs_info->tree_root, 0);
3985 btrfs_wait_ordered_extents(fs_info->tree_root, 0, 0);
3988 mutex_lock(&fs_info->cleaner_mutex);
3990 btrfs_clean_old_snapshots(fs_info->tree_root);
3991 ret = relocate_block_group(rc);
3993 mutex_unlock(&fs_info->cleaner_mutex);
3999 if (rc->extents_found == 0)
4002 printk(KERN_INFO "btrfs: found %llu extents\n",
4003 (unsigned long long)rc->extents_found);
4005 if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) {
4006 btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1);
4007 invalidate_mapping_pages(rc->data_inode->i_mapping,
4009 rc->stage = UPDATE_DATA_PTRS;
4013 filemap_write_and_wait_range(fs_info->btree_inode->i_mapping,
4014 rc->block_group->key.objectid,
4015 rc->block_group->key.objectid +
4016 rc->block_group->key.offset - 1);
4018 WARN_ON(rc->block_group->pinned > 0);
4019 WARN_ON(rc->block_group->reserved > 0);
4020 WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0);
4023 btrfs_set_block_group_rw(extent_root, rc->block_group);
4024 iput(rc->data_inode);
4025 btrfs_put_block_group(rc->block_group);
4030 static noinline_for_stack int mark_garbage_root(struct btrfs_root *root)
4032 struct btrfs_trans_handle *trans;
4035 trans = btrfs_start_transaction(root->fs_info->tree_root, 0);
4037 memset(&root->root_item.drop_progress, 0,
4038 sizeof(root->root_item.drop_progress));
4039 root->root_item.drop_level = 0;
4040 btrfs_set_root_refs(&root->root_item, 0);
4041 ret = btrfs_update_root(trans, root->fs_info->tree_root,
4042 &root->root_key, &root->root_item);
4045 ret = btrfs_end_transaction(trans, root->fs_info->tree_root);
4051 * recover relocation interrupted by system crash.
4053 * this function resumes merging reloc trees with corresponding fs trees.
4054 * this is important for keeping the sharing of tree blocks
4056 int btrfs_recover_relocation(struct btrfs_root *root)
4058 LIST_HEAD(reloc_roots);
4059 struct btrfs_key key;
4060 struct btrfs_root *fs_root;
4061 struct btrfs_root *reloc_root;
4062 struct btrfs_path *path;
4063 struct extent_buffer *leaf;
4064 struct reloc_control *rc = NULL;
4065 struct btrfs_trans_handle *trans;
4069 path = btrfs_alloc_path();
4073 key.objectid = BTRFS_TREE_RELOC_OBJECTID;
4074 key.type = BTRFS_ROOT_ITEM_KEY;
4075 key.offset = (u64)-1;
4078 ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key,
4085 if (path->slots[0] == 0)
4089 leaf = path->nodes[0];
4090 btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
4091 btrfs_release_path(root->fs_info->tree_root, path);
4093 if (key.objectid != BTRFS_TREE_RELOC_OBJECTID ||
4094 key.type != BTRFS_ROOT_ITEM_KEY)
4097 reloc_root = btrfs_read_fs_root_no_radix(root, &key);
4098 if (IS_ERR(reloc_root)) {
4099 err = PTR_ERR(reloc_root);
4103 list_add(&reloc_root->root_list, &reloc_roots);
4105 if (btrfs_root_refs(&reloc_root->root_item) > 0) {
4106 fs_root = read_fs_root(root->fs_info,
4107 reloc_root->root_key.offset);
4108 if (IS_ERR(fs_root)) {
4109 ret = PTR_ERR(fs_root);
4110 if (ret != -ENOENT) {
4114 mark_garbage_root(reloc_root);
4118 if (key.offset == 0)
4123 btrfs_release_path(root->fs_info->tree_root, path);
4125 if (list_empty(&reloc_roots))
4128 rc = alloc_reloc_control();
4134 rc->extent_root = root->fs_info->extent_root;
4136 set_reloc_control(rc);
4138 trans = btrfs_join_transaction(rc->extent_root, 1);
4139 if (IS_ERR(trans)) {
4140 unset_reloc_control(rc);
4141 err = PTR_ERR(trans);
4145 rc->merge_reloc_tree = 1;
4147 while (!list_empty(&reloc_roots)) {
4148 reloc_root = list_entry(reloc_roots.next,
4149 struct btrfs_root, root_list);
4150 list_del(&reloc_root->root_list);
4152 if (btrfs_root_refs(&reloc_root->root_item) == 0) {
4153 list_add_tail(&reloc_root->root_list,
4158 fs_root = read_fs_root(root->fs_info,
4159 reloc_root->root_key.offset);
4160 BUG_ON(IS_ERR(fs_root));
4162 __add_reloc_root(reloc_root);
4163 fs_root->reloc_root = reloc_root;
4166 btrfs_commit_transaction(trans, rc->extent_root);
4168 merge_reloc_roots(rc);
4170 unset_reloc_control(rc);
4172 trans = btrfs_join_transaction(rc->extent_root, 1);
4174 err = PTR_ERR(trans);
4176 btrfs_commit_transaction(trans, rc->extent_root);
4180 while (!list_empty(&reloc_roots)) {
4181 reloc_root = list_entry(reloc_roots.next,
4182 struct btrfs_root, root_list);
4183 list_del(&reloc_root->root_list);
4184 free_extent_buffer(reloc_root->node);
4185 free_extent_buffer(reloc_root->commit_root);
4188 btrfs_free_path(path);
4191 /* cleanup orphan inode in data relocation tree */
4192 fs_root = read_fs_root(root->fs_info,
4193 BTRFS_DATA_RELOC_TREE_OBJECTID);
4194 if (IS_ERR(fs_root))
4195 err = PTR_ERR(fs_root);
4197 btrfs_orphan_cleanup(fs_root);
4203 * helper to add ordered checksum for data relocation.
4205 * cloning checksum properly handles the nodatasum extents.
4206 * it also saves CPU time to re-calculate the checksum.
4208 int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len)
4210 struct btrfs_ordered_sum *sums;
4211 struct btrfs_sector_sum *sector_sum;
4212 struct btrfs_ordered_extent *ordered;
4213 struct btrfs_root *root = BTRFS_I(inode)->root;
4219 ordered = btrfs_lookup_ordered_extent(inode, file_pos);
4220 BUG_ON(ordered->file_offset != file_pos || ordered->len != len);
4222 disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt;
4223 ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr,
4224 disk_bytenr + len - 1, &list);
4226 while (!list_empty(&list)) {
4227 sums = list_entry(list.next, struct btrfs_ordered_sum, list);
4228 list_del_init(&sums->list);
4230 sector_sum = sums->sums;
4231 sums->bytenr = ordered->start;
4234 while (offset < sums->len) {
4235 sector_sum->bytenr += ordered->start - disk_bytenr;
4237 offset += root->sectorsize;
4240 btrfs_add_ordered_sum(inode, ordered, sums);
4242 btrfs_put_ordered_extent(ordered);
4246 void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans,
4247 struct btrfs_root *root, struct extent_buffer *buf,
4248 struct extent_buffer *cow)
4250 struct reloc_control *rc;
4251 struct backref_node *node;
4256 rc = root->fs_info->reloc_ctl;
4260 BUG_ON(rc->stage == UPDATE_DATA_PTRS &&
4261 root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID);
4263 level = btrfs_header_level(buf);
4264 if (btrfs_header_generation(buf) <=
4265 btrfs_root_last_snapshot(&root->root_item))
4268 if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID &&
4269 rc->create_reloc_tree) {
4270 WARN_ON(!first_cow && level == 0);
4272 node = rc->backref_cache.path[level];
4273 BUG_ON(node->bytenr != buf->start &&
4274 node->new_bytenr != buf->start);
4276 drop_node_buffer(node);
4277 extent_buffer_get(cow);
4279 node->new_bytenr = cow->start;
4281 if (!node->pending) {
4282 list_move_tail(&node->list,
4283 &rc->backref_cache.pending[level]);
4288 __mark_block_processed(rc, node);
4290 if (first_cow && level > 0)
4291 rc->nodes_relocated += buf->len;
4294 if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) {
4295 ret = replace_file_extents(trans, rc, root, cow);
4301 * called before creating snapshot. it calculates metadata reservation
4302 * requried for relocating tree blocks in the snapshot
4304 void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans,
4305 struct btrfs_pending_snapshot *pending,
4306 u64 *bytes_to_reserve)
4308 struct btrfs_root *root;
4309 struct reloc_control *rc;
4311 root = pending->root;
4312 if (!root->reloc_root)
4315 rc = root->fs_info->reloc_ctl;
4316 if (!rc->merge_reloc_tree)
4319 root = root->reloc_root;
4320 BUG_ON(btrfs_root_refs(&root->root_item) == 0);
4322 * relocation is in the stage of merging trees. the space
4323 * used by merging a reloc tree is twice the size of
4324 * relocated tree nodes in the worst case. half for cowing
4325 * the reloc tree, half for cowing the fs tree. the space
4326 * used by cowing the reloc tree will be freed after the
4327 * tree is dropped. if we create snapshot, cowing the fs
4328 * tree may use more space than it frees. so we need
4329 * reserve extra space.
4331 *bytes_to_reserve += rc->nodes_relocated;
4335 * called after snapshot is created. migrate block reservation
4336 * and create reloc root for the newly created snapshot
4338 void btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans,
4339 struct btrfs_pending_snapshot *pending)
4341 struct btrfs_root *root = pending->root;
4342 struct btrfs_root *reloc_root;
4343 struct btrfs_root *new_root;
4344 struct reloc_control *rc;
4347 if (!root->reloc_root)
4350 rc = root->fs_info->reloc_ctl;
4351 rc->merging_rsv_size += rc->nodes_relocated;
4353 if (rc->merge_reloc_tree) {
4354 ret = btrfs_block_rsv_migrate(&pending->block_rsv,
4356 rc->nodes_relocated);
4360 new_root = pending->snap;
4361 reloc_root = create_reloc_root(trans, root->reloc_root,
4362 new_root->root_key.objectid);
4364 __add_reloc_root(reloc_root);
4365 new_root->reloc_root = reloc_root;
4367 if (rc->create_reloc_tree) {
4368 ret = clone_backref_node(trans, rc, root, reloc_root);