15d4f98a2SYan Zheng /* 25d4f98a2SYan Zheng * Copyright (C) 2009 Oracle. All rights reserved. 35d4f98a2SYan Zheng * 45d4f98a2SYan Zheng * This program is free software; you can redistribute it and/or 55d4f98a2SYan Zheng * modify it under the terms of the GNU General Public 65d4f98a2SYan Zheng * License v2 as published by the Free Software Foundation. 75d4f98a2SYan Zheng * 85d4f98a2SYan Zheng * This program is distributed in the hope that it will be useful, 95d4f98a2SYan Zheng * but WITHOUT ANY WARRANTY; without even the implied warranty of 105d4f98a2SYan Zheng * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 115d4f98a2SYan Zheng * General Public License for more details. 125d4f98a2SYan Zheng * 135d4f98a2SYan Zheng * You should have received a copy of the GNU General Public 145d4f98a2SYan Zheng * License along with this program; if not, write to the 155d4f98a2SYan Zheng * Free Software Foundation, Inc., 59 Temple Place - Suite 330, 165d4f98a2SYan Zheng * Boston, MA 021110-1307, USA. 175d4f98a2SYan Zheng */ 185d4f98a2SYan Zheng 195d4f98a2SYan Zheng #include <linux/sched.h> 205d4f98a2SYan Zheng #include <linux/pagemap.h> 215d4f98a2SYan Zheng #include <linux/writeback.h> 225d4f98a2SYan Zheng #include <linux/blkdev.h> 235d4f98a2SYan Zheng #include <linux/rbtree.h> 245a0e3ad6STejun Heo #include <linux/slab.h> 255d4f98a2SYan Zheng #include "ctree.h" 265d4f98a2SYan Zheng #include "disk-io.h" 275d4f98a2SYan Zheng #include "transaction.h" 285d4f98a2SYan Zheng #include "volumes.h" 295d4f98a2SYan Zheng #include "locking.h" 305d4f98a2SYan Zheng #include "btrfs_inode.h" 315d4f98a2SYan Zheng #include "async-thread.h" 325d4f98a2SYan Zheng 335d4f98a2SYan Zheng /* 345d4f98a2SYan Zheng * backref_node, mapping_node and tree_block start with this 355d4f98a2SYan Zheng */ 365d4f98a2SYan Zheng struct tree_entry { 375d4f98a2SYan Zheng struct rb_node rb_node; 385d4f98a2SYan Zheng u64 bytenr; 395d4f98a2SYan Zheng }; 405d4f98a2SYan Zheng 415d4f98a2SYan Zheng /* 425d4f98a2SYan Zheng * present a tree block in the backref cache 435d4f98a2SYan Zheng */ 445d4f98a2SYan Zheng struct backref_node { 455d4f98a2SYan Zheng struct rb_node rb_node; 465d4f98a2SYan Zheng u64 bytenr; 473fd0a558SYan, Zheng 483fd0a558SYan, Zheng u64 new_bytenr; 493fd0a558SYan, Zheng /* objectid of tree block owner, can be not uptodate */ 505d4f98a2SYan Zheng u64 owner; 513fd0a558SYan, Zheng /* link to pending, changed or detached list */ 523fd0a558SYan, Zheng struct list_head list; 535d4f98a2SYan Zheng /* list of upper level blocks reference this block */ 545d4f98a2SYan Zheng struct list_head upper; 555d4f98a2SYan Zheng /* list of child blocks in the cache */ 565d4f98a2SYan Zheng struct list_head lower; 575d4f98a2SYan Zheng /* NULL if this node is not tree root */ 585d4f98a2SYan Zheng struct btrfs_root *root; 595d4f98a2SYan Zheng /* extent buffer got by COW the block */ 605d4f98a2SYan Zheng struct extent_buffer *eb; 615d4f98a2SYan Zheng /* level of tree block */ 625d4f98a2SYan Zheng unsigned int level:8; 633fd0a558SYan, Zheng /* is the block in non-reference counted tree */ 643fd0a558SYan, Zheng unsigned int cowonly:1; 653fd0a558SYan, Zheng /* 1 if no child node in the cache */ 665d4f98a2SYan Zheng unsigned int lowest:1; 675d4f98a2SYan Zheng /* is the extent buffer locked */ 685d4f98a2SYan Zheng unsigned int locked:1; 695d4f98a2SYan Zheng /* has the block been processed */ 705d4f98a2SYan Zheng unsigned int processed:1; 715d4f98a2SYan Zheng /* have backrefs of this block been checked */ 725d4f98a2SYan Zheng unsigned int checked:1; 733fd0a558SYan, Zheng /* 743fd0a558SYan, Zheng * 1 if corresponding block has been cowed but some upper 753fd0a558SYan, Zheng * level block pointers may not point to the new location 763fd0a558SYan, Zheng */ 773fd0a558SYan, Zheng unsigned int pending:1; 783fd0a558SYan, Zheng /* 793fd0a558SYan, Zheng * 1 if the backref node isn't connected to any other 803fd0a558SYan, Zheng * backref node. 813fd0a558SYan, Zheng */ 823fd0a558SYan, Zheng unsigned int detached:1; 835d4f98a2SYan Zheng }; 845d4f98a2SYan Zheng 855d4f98a2SYan Zheng /* 865d4f98a2SYan Zheng * present a block pointer in the backref cache 875d4f98a2SYan Zheng */ 885d4f98a2SYan Zheng struct backref_edge { 895d4f98a2SYan Zheng struct list_head list[2]; 905d4f98a2SYan Zheng struct backref_node *node[2]; 915d4f98a2SYan Zheng }; 925d4f98a2SYan Zheng 935d4f98a2SYan Zheng #define LOWER 0 945d4f98a2SYan Zheng #define UPPER 1 955d4f98a2SYan Zheng 965d4f98a2SYan Zheng struct backref_cache { 975d4f98a2SYan Zheng /* red black tree of all backref nodes in the cache */ 985d4f98a2SYan Zheng struct rb_root rb_root; 993fd0a558SYan, Zheng /* for passing backref nodes to btrfs_reloc_cow_block */ 1003fd0a558SYan, Zheng struct backref_node *path[BTRFS_MAX_LEVEL]; 1013fd0a558SYan, Zheng /* 1023fd0a558SYan, Zheng * list of blocks that have been cowed but some block 1033fd0a558SYan, Zheng * pointers in upper level blocks may not reflect the 1043fd0a558SYan, Zheng * new location 1053fd0a558SYan, Zheng */ 1065d4f98a2SYan Zheng struct list_head pending[BTRFS_MAX_LEVEL]; 1073fd0a558SYan, Zheng /* list of backref nodes with no child node */ 1083fd0a558SYan, Zheng struct list_head leaves; 1093fd0a558SYan, Zheng /* list of blocks that have been cowed in current transaction */ 1103fd0a558SYan, Zheng struct list_head changed; 1113fd0a558SYan, Zheng /* list of detached backref node. */ 1123fd0a558SYan, Zheng struct list_head detached; 1133fd0a558SYan, Zheng 1143fd0a558SYan, Zheng u64 last_trans; 1153fd0a558SYan, Zheng 1163fd0a558SYan, Zheng int nr_nodes; 1173fd0a558SYan, Zheng int nr_edges; 1185d4f98a2SYan Zheng }; 1195d4f98a2SYan Zheng 1205d4f98a2SYan Zheng /* 1215d4f98a2SYan Zheng * map address of tree root to tree 1225d4f98a2SYan Zheng */ 1235d4f98a2SYan Zheng struct mapping_node { 1245d4f98a2SYan Zheng struct rb_node rb_node; 1255d4f98a2SYan Zheng u64 bytenr; 1265d4f98a2SYan Zheng void *data; 1275d4f98a2SYan Zheng }; 1285d4f98a2SYan Zheng 1295d4f98a2SYan Zheng struct mapping_tree { 1305d4f98a2SYan Zheng struct rb_root rb_root; 1315d4f98a2SYan Zheng spinlock_t lock; 1325d4f98a2SYan Zheng }; 1335d4f98a2SYan Zheng 1345d4f98a2SYan Zheng /* 1355d4f98a2SYan Zheng * present a tree block to process 1365d4f98a2SYan Zheng */ 1375d4f98a2SYan Zheng struct tree_block { 1385d4f98a2SYan Zheng struct rb_node rb_node; 1395d4f98a2SYan Zheng u64 bytenr; 1405d4f98a2SYan Zheng struct btrfs_key key; 1415d4f98a2SYan Zheng unsigned int level:8; 1425d4f98a2SYan Zheng unsigned int key_ready:1; 1435d4f98a2SYan Zheng }; 1445d4f98a2SYan Zheng 1450257bb82SYan, Zheng #define MAX_EXTENTS 128 1460257bb82SYan, Zheng 1470257bb82SYan, Zheng struct file_extent_cluster { 1480257bb82SYan, Zheng u64 start; 1490257bb82SYan, Zheng u64 end; 1500257bb82SYan, Zheng u64 boundary[MAX_EXTENTS]; 1510257bb82SYan, Zheng unsigned int nr; 1520257bb82SYan, Zheng }; 1530257bb82SYan, Zheng 1545d4f98a2SYan Zheng struct reloc_control { 1555d4f98a2SYan Zheng /* block group to relocate */ 1565d4f98a2SYan Zheng struct btrfs_block_group_cache *block_group; 1575d4f98a2SYan Zheng /* extent tree */ 1585d4f98a2SYan Zheng struct btrfs_root *extent_root; 1595d4f98a2SYan Zheng /* inode for moving data */ 1605d4f98a2SYan Zheng struct inode *data_inode; 1613fd0a558SYan, Zheng 1623fd0a558SYan, Zheng struct btrfs_block_rsv *block_rsv; 1633fd0a558SYan, Zheng 1643fd0a558SYan, Zheng struct backref_cache backref_cache; 1653fd0a558SYan, Zheng 1663fd0a558SYan, Zheng struct file_extent_cluster cluster; 1675d4f98a2SYan Zheng /* tree blocks have been processed */ 1685d4f98a2SYan Zheng struct extent_io_tree processed_blocks; 1695d4f98a2SYan Zheng /* map start of tree root to corresponding reloc tree */ 1705d4f98a2SYan Zheng struct mapping_tree reloc_root_tree; 1715d4f98a2SYan Zheng /* list of reloc trees */ 1725d4f98a2SYan Zheng struct list_head reloc_roots; 1733fd0a558SYan, Zheng /* size of metadata reservation for merging reloc trees */ 1743fd0a558SYan, Zheng u64 merging_rsv_size; 1753fd0a558SYan, Zheng /* size of relocated tree nodes */ 1763fd0a558SYan, Zheng u64 nodes_relocated; 1773fd0a558SYan, Zheng 1785d4f98a2SYan Zheng u64 search_start; 1795d4f98a2SYan Zheng u64 extents_found; 1803fd0a558SYan, Zheng 1813fd0a558SYan, Zheng int block_rsv_retries; 1823fd0a558SYan, Zheng 1833fd0a558SYan, Zheng unsigned int stage:8; 1843fd0a558SYan, Zheng unsigned int create_reloc_tree:1; 1853fd0a558SYan, Zheng unsigned int merge_reloc_tree:1; 1865d4f98a2SYan Zheng unsigned int found_file_extent:1; 1873fd0a558SYan, Zheng unsigned int commit_transaction:1; 1885d4f98a2SYan Zheng }; 1895d4f98a2SYan Zheng 1905d4f98a2SYan Zheng /* stages of data relocation */ 1915d4f98a2SYan Zheng #define MOVE_DATA_EXTENTS 0 1925d4f98a2SYan Zheng #define UPDATE_DATA_PTRS 1 1935d4f98a2SYan Zheng 1943fd0a558SYan, Zheng static void remove_backref_node(struct backref_cache *cache, 1953fd0a558SYan, Zheng struct backref_node *node); 1963fd0a558SYan, Zheng static void __mark_block_processed(struct reloc_control *rc, 1973fd0a558SYan, Zheng struct backref_node *node); 1985d4f98a2SYan Zheng 1995d4f98a2SYan Zheng static void mapping_tree_init(struct mapping_tree *tree) 2005d4f98a2SYan Zheng { 2016bef4d31SEric Paris tree->rb_root = RB_ROOT; 2025d4f98a2SYan Zheng spin_lock_init(&tree->lock); 2035d4f98a2SYan Zheng } 2045d4f98a2SYan Zheng 2055d4f98a2SYan Zheng static void backref_cache_init(struct backref_cache *cache) 2065d4f98a2SYan Zheng { 2075d4f98a2SYan Zheng int i; 2086bef4d31SEric Paris cache->rb_root = RB_ROOT; 2095d4f98a2SYan Zheng for (i = 0; i < BTRFS_MAX_LEVEL; i++) 2105d4f98a2SYan Zheng INIT_LIST_HEAD(&cache->pending[i]); 2113fd0a558SYan, Zheng INIT_LIST_HEAD(&cache->changed); 2123fd0a558SYan, Zheng INIT_LIST_HEAD(&cache->detached); 2133fd0a558SYan, Zheng INIT_LIST_HEAD(&cache->leaves); 2145d4f98a2SYan Zheng } 2155d4f98a2SYan Zheng 2163fd0a558SYan, Zheng static void backref_cache_cleanup(struct backref_cache *cache) 2175d4f98a2SYan Zheng { 2183fd0a558SYan, Zheng struct backref_node *node; 2193fd0a558SYan, Zheng int i; 2203fd0a558SYan, Zheng 2213fd0a558SYan, Zheng while (!list_empty(&cache->detached)) { 2223fd0a558SYan, Zheng node = list_entry(cache->detached.next, 2233fd0a558SYan, Zheng struct backref_node, list); 2243fd0a558SYan, Zheng remove_backref_node(cache, node); 2253fd0a558SYan, Zheng } 2263fd0a558SYan, Zheng 2273fd0a558SYan, Zheng while (!list_empty(&cache->leaves)) { 2283fd0a558SYan, Zheng node = list_entry(cache->leaves.next, 2293fd0a558SYan, Zheng struct backref_node, lower); 2303fd0a558SYan, Zheng remove_backref_node(cache, node); 2313fd0a558SYan, Zheng } 2323fd0a558SYan, Zheng 2333fd0a558SYan, Zheng cache->last_trans = 0; 2343fd0a558SYan, Zheng 2353fd0a558SYan, Zheng for (i = 0; i < BTRFS_MAX_LEVEL; i++) 2363fd0a558SYan, Zheng BUG_ON(!list_empty(&cache->pending[i])); 2373fd0a558SYan, Zheng BUG_ON(!list_empty(&cache->changed)); 2383fd0a558SYan, Zheng BUG_ON(!list_empty(&cache->detached)); 2393fd0a558SYan, Zheng BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root)); 2403fd0a558SYan, Zheng BUG_ON(cache->nr_nodes); 2413fd0a558SYan, Zheng BUG_ON(cache->nr_edges); 2423fd0a558SYan, Zheng } 2433fd0a558SYan, Zheng 2443fd0a558SYan, Zheng static struct backref_node *alloc_backref_node(struct backref_cache *cache) 2453fd0a558SYan, Zheng { 2463fd0a558SYan, Zheng struct backref_node *node; 2473fd0a558SYan, Zheng 2483fd0a558SYan, Zheng node = kzalloc(sizeof(*node), GFP_NOFS); 2493fd0a558SYan, Zheng if (node) { 2503fd0a558SYan, Zheng INIT_LIST_HEAD(&node->list); 2515d4f98a2SYan Zheng INIT_LIST_HEAD(&node->upper); 2525d4f98a2SYan Zheng INIT_LIST_HEAD(&node->lower); 2535d4f98a2SYan Zheng RB_CLEAR_NODE(&node->rb_node); 2543fd0a558SYan, Zheng cache->nr_nodes++; 2553fd0a558SYan, Zheng } 2563fd0a558SYan, Zheng return node; 2573fd0a558SYan, Zheng } 2583fd0a558SYan, Zheng 2593fd0a558SYan, Zheng static void free_backref_node(struct backref_cache *cache, 2603fd0a558SYan, Zheng struct backref_node *node) 2613fd0a558SYan, Zheng { 2623fd0a558SYan, Zheng if (node) { 2633fd0a558SYan, Zheng cache->nr_nodes--; 2643fd0a558SYan, Zheng kfree(node); 2653fd0a558SYan, Zheng } 2663fd0a558SYan, Zheng } 2673fd0a558SYan, Zheng 2683fd0a558SYan, Zheng static struct backref_edge *alloc_backref_edge(struct backref_cache *cache) 2693fd0a558SYan, Zheng { 2703fd0a558SYan, Zheng struct backref_edge *edge; 2713fd0a558SYan, Zheng 2723fd0a558SYan, Zheng edge = kzalloc(sizeof(*edge), GFP_NOFS); 2733fd0a558SYan, Zheng if (edge) 2743fd0a558SYan, Zheng cache->nr_edges++; 2753fd0a558SYan, Zheng return edge; 2763fd0a558SYan, Zheng } 2773fd0a558SYan, Zheng 2783fd0a558SYan, Zheng static void free_backref_edge(struct backref_cache *cache, 2793fd0a558SYan, Zheng struct backref_edge *edge) 2803fd0a558SYan, Zheng { 2813fd0a558SYan, Zheng if (edge) { 2823fd0a558SYan, Zheng cache->nr_edges--; 2833fd0a558SYan, Zheng kfree(edge); 2843fd0a558SYan, Zheng } 2855d4f98a2SYan Zheng } 2865d4f98a2SYan Zheng 2875d4f98a2SYan Zheng static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr, 2885d4f98a2SYan Zheng struct rb_node *node) 2895d4f98a2SYan Zheng { 2905d4f98a2SYan Zheng struct rb_node **p = &root->rb_node; 2915d4f98a2SYan Zheng struct rb_node *parent = NULL; 2925d4f98a2SYan Zheng struct tree_entry *entry; 2935d4f98a2SYan Zheng 2945d4f98a2SYan Zheng while (*p) { 2955d4f98a2SYan Zheng parent = *p; 2965d4f98a2SYan Zheng entry = rb_entry(parent, struct tree_entry, rb_node); 2975d4f98a2SYan Zheng 2985d4f98a2SYan Zheng if (bytenr < entry->bytenr) 2995d4f98a2SYan Zheng p = &(*p)->rb_left; 3005d4f98a2SYan Zheng else if (bytenr > entry->bytenr) 3015d4f98a2SYan Zheng p = &(*p)->rb_right; 3025d4f98a2SYan Zheng else 3035d4f98a2SYan Zheng return parent; 3045d4f98a2SYan Zheng } 3055d4f98a2SYan Zheng 3065d4f98a2SYan Zheng rb_link_node(node, parent, p); 3075d4f98a2SYan Zheng rb_insert_color(node, root); 3085d4f98a2SYan Zheng return NULL; 3095d4f98a2SYan Zheng } 3105d4f98a2SYan Zheng 3115d4f98a2SYan Zheng static struct rb_node *tree_search(struct rb_root *root, u64 bytenr) 3125d4f98a2SYan Zheng { 3135d4f98a2SYan Zheng struct rb_node *n = root->rb_node; 3145d4f98a2SYan Zheng struct tree_entry *entry; 3155d4f98a2SYan Zheng 3165d4f98a2SYan Zheng while (n) { 3175d4f98a2SYan Zheng entry = rb_entry(n, struct tree_entry, rb_node); 3185d4f98a2SYan Zheng 3195d4f98a2SYan Zheng if (bytenr < entry->bytenr) 3205d4f98a2SYan Zheng n = n->rb_left; 3215d4f98a2SYan Zheng else if (bytenr > entry->bytenr) 3225d4f98a2SYan Zheng n = n->rb_right; 3235d4f98a2SYan Zheng else 3245d4f98a2SYan Zheng return n; 3255d4f98a2SYan Zheng } 3265d4f98a2SYan Zheng return NULL; 3275d4f98a2SYan Zheng } 3285d4f98a2SYan Zheng 3295d4f98a2SYan Zheng /* 3305d4f98a2SYan Zheng * walk up backref nodes until reach node presents tree root 3315d4f98a2SYan Zheng */ 3325d4f98a2SYan Zheng static struct backref_node *walk_up_backref(struct backref_node *node, 3335d4f98a2SYan Zheng struct backref_edge *edges[], 3345d4f98a2SYan Zheng int *index) 3355d4f98a2SYan Zheng { 3365d4f98a2SYan Zheng struct backref_edge *edge; 3375d4f98a2SYan Zheng int idx = *index; 3385d4f98a2SYan Zheng 3395d4f98a2SYan Zheng while (!list_empty(&node->upper)) { 3405d4f98a2SYan Zheng edge = list_entry(node->upper.next, 3415d4f98a2SYan Zheng struct backref_edge, list[LOWER]); 3425d4f98a2SYan Zheng edges[idx++] = edge; 3435d4f98a2SYan Zheng node = edge->node[UPPER]; 3445d4f98a2SYan Zheng } 3453fd0a558SYan, Zheng BUG_ON(node->detached); 3465d4f98a2SYan Zheng *index = idx; 3475d4f98a2SYan Zheng return node; 3485d4f98a2SYan Zheng } 3495d4f98a2SYan Zheng 3505d4f98a2SYan Zheng /* 3515d4f98a2SYan Zheng * walk down backref nodes to find start of next reference path 3525d4f98a2SYan Zheng */ 3535d4f98a2SYan Zheng static struct backref_node *walk_down_backref(struct backref_edge *edges[], 3545d4f98a2SYan Zheng int *index) 3555d4f98a2SYan Zheng { 3565d4f98a2SYan Zheng struct backref_edge *edge; 3575d4f98a2SYan Zheng struct backref_node *lower; 3585d4f98a2SYan Zheng int idx = *index; 3595d4f98a2SYan Zheng 3605d4f98a2SYan Zheng while (idx > 0) { 3615d4f98a2SYan Zheng edge = edges[idx - 1]; 3625d4f98a2SYan Zheng lower = edge->node[LOWER]; 3635d4f98a2SYan Zheng if (list_is_last(&edge->list[LOWER], &lower->upper)) { 3645d4f98a2SYan Zheng idx--; 3655d4f98a2SYan Zheng continue; 3665d4f98a2SYan Zheng } 3675d4f98a2SYan Zheng edge = list_entry(edge->list[LOWER].next, 3685d4f98a2SYan Zheng struct backref_edge, list[LOWER]); 3695d4f98a2SYan Zheng edges[idx - 1] = edge; 3705d4f98a2SYan Zheng *index = idx; 3715d4f98a2SYan Zheng return edge->node[UPPER]; 3725d4f98a2SYan Zheng } 3735d4f98a2SYan Zheng *index = 0; 3745d4f98a2SYan Zheng return NULL; 3755d4f98a2SYan Zheng } 3765d4f98a2SYan Zheng 3773fd0a558SYan, Zheng static void unlock_node_buffer(struct backref_node *node) 3785d4f98a2SYan Zheng { 3795d4f98a2SYan Zheng if (node->locked) { 3805d4f98a2SYan Zheng btrfs_tree_unlock(node->eb); 3815d4f98a2SYan Zheng node->locked = 0; 3825d4f98a2SYan Zheng } 3833fd0a558SYan, Zheng } 3843fd0a558SYan, Zheng 3853fd0a558SYan, Zheng static void drop_node_buffer(struct backref_node *node) 3863fd0a558SYan, Zheng { 3873fd0a558SYan, Zheng if (node->eb) { 3883fd0a558SYan, Zheng unlock_node_buffer(node); 3895d4f98a2SYan Zheng free_extent_buffer(node->eb); 3905d4f98a2SYan Zheng node->eb = NULL; 3915d4f98a2SYan Zheng } 3925d4f98a2SYan Zheng } 3935d4f98a2SYan Zheng 3945d4f98a2SYan Zheng static void drop_backref_node(struct backref_cache *tree, 3955d4f98a2SYan Zheng struct backref_node *node) 3965d4f98a2SYan Zheng { 3975d4f98a2SYan Zheng BUG_ON(!list_empty(&node->upper)); 3985d4f98a2SYan Zheng 3995d4f98a2SYan Zheng drop_node_buffer(node); 4003fd0a558SYan, Zheng list_del(&node->list); 4015d4f98a2SYan Zheng list_del(&node->lower); 4023fd0a558SYan, Zheng if (!RB_EMPTY_NODE(&node->rb_node)) 4035d4f98a2SYan Zheng rb_erase(&node->rb_node, &tree->rb_root); 4043fd0a558SYan, Zheng free_backref_node(tree, node); 4055d4f98a2SYan Zheng } 4065d4f98a2SYan Zheng 4075d4f98a2SYan Zheng /* 4085d4f98a2SYan Zheng * remove a backref node from the backref cache 4095d4f98a2SYan Zheng */ 4105d4f98a2SYan Zheng static void remove_backref_node(struct backref_cache *cache, 4115d4f98a2SYan Zheng struct backref_node *node) 4125d4f98a2SYan Zheng { 4135d4f98a2SYan Zheng struct backref_node *upper; 4145d4f98a2SYan Zheng struct backref_edge *edge; 4155d4f98a2SYan Zheng 4165d4f98a2SYan Zheng if (!node) 4175d4f98a2SYan Zheng return; 4185d4f98a2SYan Zheng 4193fd0a558SYan, Zheng BUG_ON(!node->lowest && !node->detached); 4205d4f98a2SYan Zheng while (!list_empty(&node->upper)) { 4215d4f98a2SYan Zheng edge = list_entry(node->upper.next, struct backref_edge, 4225d4f98a2SYan Zheng list[LOWER]); 4235d4f98a2SYan Zheng upper = edge->node[UPPER]; 4245d4f98a2SYan Zheng list_del(&edge->list[LOWER]); 4255d4f98a2SYan Zheng list_del(&edge->list[UPPER]); 4263fd0a558SYan, Zheng free_backref_edge(cache, edge); 4273fd0a558SYan, Zheng 4283fd0a558SYan, Zheng if (RB_EMPTY_NODE(&upper->rb_node)) { 4293fd0a558SYan, Zheng BUG_ON(!list_empty(&node->upper)); 4303fd0a558SYan, Zheng drop_backref_node(cache, node); 4313fd0a558SYan, Zheng node = upper; 4323fd0a558SYan, Zheng node->lowest = 1; 4333fd0a558SYan, Zheng continue; 4343fd0a558SYan, Zheng } 4355d4f98a2SYan Zheng /* 4363fd0a558SYan, Zheng * add the node to leaf node list if no other 4375d4f98a2SYan Zheng * child block cached. 4385d4f98a2SYan Zheng */ 4395d4f98a2SYan Zheng if (list_empty(&upper->lower)) { 4403fd0a558SYan, Zheng list_add_tail(&upper->lower, &cache->leaves); 4415d4f98a2SYan Zheng upper->lowest = 1; 4425d4f98a2SYan Zheng } 4435d4f98a2SYan Zheng } 4443fd0a558SYan, Zheng 4455d4f98a2SYan Zheng drop_backref_node(cache, node); 4465d4f98a2SYan Zheng } 4475d4f98a2SYan Zheng 4483fd0a558SYan, Zheng static void update_backref_node(struct backref_cache *cache, 4493fd0a558SYan, Zheng struct backref_node *node, u64 bytenr) 4503fd0a558SYan, Zheng { 4513fd0a558SYan, Zheng struct rb_node *rb_node; 4523fd0a558SYan, Zheng rb_erase(&node->rb_node, &cache->rb_root); 4533fd0a558SYan, Zheng node->bytenr = bytenr; 4543fd0a558SYan, Zheng rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node); 4553fd0a558SYan, Zheng BUG_ON(rb_node); 4563fd0a558SYan, Zheng } 4573fd0a558SYan, Zheng 4583fd0a558SYan, Zheng /* 4593fd0a558SYan, Zheng * update backref cache after a transaction commit 4603fd0a558SYan, Zheng */ 4613fd0a558SYan, Zheng static int update_backref_cache(struct btrfs_trans_handle *trans, 4623fd0a558SYan, Zheng struct backref_cache *cache) 4633fd0a558SYan, Zheng { 4643fd0a558SYan, Zheng struct backref_node *node; 4653fd0a558SYan, Zheng int level = 0; 4663fd0a558SYan, Zheng 4673fd0a558SYan, Zheng if (cache->last_trans == 0) { 4683fd0a558SYan, Zheng cache->last_trans = trans->transid; 4693fd0a558SYan, Zheng return 0; 4703fd0a558SYan, Zheng } 4713fd0a558SYan, Zheng 4723fd0a558SYan, Zheng if (cache->last_trans == trans->transid) 4733fd0a558SYan, Zheng return 0; 4743fd0a558SYan, Zheng 4753fd0a558SYan, Zheng /* 4763fd0a558SYan, Zheng * detached nodes are used to avoid unnecessary backref 4773fd0a558SYan, Zheng * lookup. transaction commit changes the extent tree. 4783fd0a558SYan, Zheng * so the detached nodes are no longer useful. 4793fd0a558SYan, Zheng */ 4803fd0a558SYan, Zheng while (!list_empty(&cache->detached)) { 4813fd0a558SYan, Zheng node = list_entry(cache->detached.next, 4823fd0a558SYan, Zheng struct backref_node, list); 4833fd0a558SYan, Zheng remove_backref_node(cache, node); 4843fd0a558SYan, Zheng } 4853fd0a558SYan, Zheng 4863fd0a558SYan, Zheng while (!list_empty(&cache->changed)) { 4873fd0a558SYan, Zheng node = list_entry(cache->changed.next, 4883fd0a558SYan, Zheng struct backref_node, list); 4893fd0a558SYan, Zheng list_del_init(&node->list); 4903fd0a558SYan, Zheng BUG_ON(node->pending); 4913fd0a558SYan, Zheng update_backref_node(cache, node, node->new_bytenr); 4923fd0a558SYan, Zheng } 4933fd0a558SYan, Zheng 4943fd0a558SYan, Zheng /* 4953fd0a558SYan, Zheng * some nodes can be left in the pending list if there were 4963fd0a558SYan, Zheng * errors during processing the pending nodes. 4973fd0a558SYan, Zheng */ 4983fd0a558SYan, Zheng for (level = 0; level < BTRFS_MAX_LEVEL; level++) { 4993fd0a558SYan, Zheng list_for_each_entry(node, &cache->pending[level], list) { 5003fd0a558SYan, Zheng BUG_ON(!node->pending); 5013fd0a558SYan, Zheng if (node->bytenr == node->new_bytenr) 5023fd0a558SYan, Zheng continue; 5033fd0a558SYan, Zheng update_backref_node(cache, node, node->new_bytenr); 5043fd0a558SYan, Zheng } 5053fd0a558SYan, Zheng } 5063fd0a558SYan, Zheng 5073fd0a558SYan, Zheng cache->last_trans = 0; 5083fd0a558SYan, Zheng return 1; 5093fd0a558SYan, Zheng } 5103fd0a558SYan, Zheng 5113fd0a558SYan, Zheng static int should_ignore_root(struct btrfs_root *root) 5123fd0a558SYan, Zheng { 5133fd0a558SYan, Zheng struct btrfs_root *reloc_root; 5143fd0a558SYan, Zheng 5153fd0a558SYan, Zheng if (!root->ref_cows) 5163fd0a558SYan, Zheng return 0; 5173fd0a558SYan, Zheng 5183fd0a558SYan, Zheng reloc_root = root->reloc_root; 5193fd0a558SYan, Zheng if (!reloc_root) 5203fd0a558SYan, Zheng return 0; 5213fd0a558SYan, Zheng 5223fd0a558SYan, Zheng if (btrfs_root_last_snapshot(&reloc_root->root_item) == 5233fd0a558SYan, Zheng root->fs_info->running_transaction->transid - 1) 5243fd0a558SYan, Zheng return 0; 5253fd0a558SYan, Zheng /* 5263fd0a558SYan, Zheng * if there is reloc tree and it was created in previous 5273fd0a558SYan, Zheng * transaction backref lookup can find the reloc tree, 5283fd0a558SYan, Zheng * so backref node for the fs tree root is useless for 5293fd0a558SYan, Zheng * relocation. 5303fd0a558SYan, Zheng */ 5313fd0a558SYan, Zheng return 1; 5323fd0a558SYan, Zheng } 5333fd0a558SYan, Zheng 5345d4f98a2SYan Zheng /* 5355d4f98a2SYan Zheng * find reloc tree by address of tree root 5365d4f98a2SYan Zheng */ 5375d4f98a2SYan Zheng static struct btrfs_root *find_reloc_root(struct reloc_control *rc, 5385d4f98a2SYan Zheng u64 bytenr) 5395d4f98a2SYan Zheng { 5405d4f98a2SYan Zheng struct rb_node *rb_node; 5415d4f98a2SYan Zheng struct mapping_node *node; 5425d4f98a2SYan Zheng struct btrfs_root *root = NULL; 5435d4f98a2SYan Zheng 5445d4f98a2SYan Zheng spin_lock(&rc->reloc_root_tree.lock); 5455d4f98a2SYan Zheng rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr); 5465d4f98a2SYan Zheng if (rb_node) { 5475d4f98a2SYan Zheng node = rb_entry(rb_node, struct mapping_node, rb_node); 5485d4f98a2SYan Zheng root = (struct btrfs_root *)node->data; 5495d4f98a2SYan Zheng } 5505d4f98a2SYan Zheng spin_unlock(&rc->reloc_root_tree.lock); 5515d4f98a2SYan Zheng return root; 5525d4f98a2SYan Zheng } 5535d4f98a2SYan Zheng 5545d4f98a2SYan Zheng static int is_cowonly_root(u64 root_objectid) 5555d4f98a2SYan Zheng { 5565d4f98a2SYan Zheng if (root_objectid == BTRFS_ROOT_TREE_OBJECTID || 5575d4f98a2SYan Zheng root_objectid == BTRFS_EXTENT_TREE_OBJECTID || 5585d4f98a2SYan Zheng root_objectid == BTRFS_CHUNK_TREE_OBJECTID || 5595d4f98a2SYan Zheng root_objectid == BTRFS_DEV_TREE_OBJECTID || 5605d4f98a2SYan Zheng root_objectid == BTRFS_TREE_LOG_OBJECTID || 5615d4f98a2SYan Zheng root_objectid == BTRFS_CSUM_TREE_OBJECTID) 5625d4f98a2SYan Zheng return 1; 5635d4f98a2SYan Zheng return 0; 5645d4f98a2SYan Zheng } 5655d4f98a2SYan Zheng 5665d4f98a2SYan Zheng static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, 5675d4f98a2SYan Zheng u64 root_objectid) 5685d4f98a2SYan Zheng { 5695d4f98a2SYan Zheng struct btrfs_key key; 5705d4f98a2SYan Zheng 5715d4f98a2SYan Zheng key.objectid = root_objectid; 5725d4f98a2SYan Zheng key.type = BTRFS_ROOT_ITEM_KEY; 5735d4f98a2SYan Zheng if (is_cowonly_root(root_objectid)) 5745d4f98a2SYan Zheng key.offset = 0; 5755d4f98a2SYan Zheng else 5765d4f98a2SYan Zheng key.offset = (u64)-1; 5775d4f98a2SYan Zheng 5785d4f98a2SYan Zheng return btrfs_read_fs_root_no_name(fs_info, &key); 5795d4f98a2SYan Zheng } 5805d4f98a2SYan Zheng 5815d4f98a2SYan Zheng #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 5825d4f98a2SYan Zheng static noinline_for_stack 5835d4f98a2SYan Zheng struct btrfs_root *find_tree_root(struct reloc_control *rc, 5845d4f98a2SYan Zheng struct extent_buffer *leaf, 5855d4f98a2SYan Zheng struct btrfs_extent_ref_v0 *ref0) 5865d4f98a2SYan Zheng { 5875d4f98a2SYan Zheng struct btrfs_root *root; 5885d4f98a2SYan Zheng u64 root_objectid = btrfs_ref_root_v0(leaf, ref0); 5895d4f98a2SYan Zheng u64 generation = btrfs_ref_generation_v0(leaf, ref0); 5905d4f98a2SYan Zheng 5915d4f98a2SYan Zheng BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID); 5925d4f98a2SYan Zheng 5935d4f98a2SYan Zheng root = read_fs_root(rc->extent_root->fs_info, root_objectid); 5945d4f98a2SYan Zheng BUG_ON(IS_ERR(root)); 5955d4f98a2SYan Zheng 5965d4f98a2SYan Zheng if (root->ref_cows && 5975d4f98a2SYan Zheng generation != btrfs_root_generation(&root->root_item)) 5985d4f98a2SYan Zheng return NULL; 5995d4f98a2SYan Zheng 6005d4f98a2SYan Zheng return root; 6015d4f98a2SYan Zheng } 6025d4f98a2SYan Zheng #endif 6035d4f98a2SYan Zheng 6045d4f98a2SYan Zheng static noinline_for_stack 6055d4f98a2SYan Zheng int find_inline_backref(struct extent_buffer *leaf, int slot, 6065d4f98a2SYan Zheng unsigned long *ptr, unsigned long *end) 6075d4f98a2SYan Zheng { 6085d4f98a2SYan Zheng struct btrfs_extent_item *ei; 6095d4f98a2SYan Zheng struct btrfs_tree_block_info *bi; 6105d4f98a2SYan Zheng u32 item_size; 6115d4f98a2SYan Zheng 6125d4f98a2SYan Zheng item_size = btrfs_item_size_nr(leaf, slot); 6135d4f98a2SYan Zheng #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 6145d4f98a2SYan Zheng if (item_size < sizeof(*ei)) { 6155d4f98a2SYan Zheng WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0)); 6165d4f98a2SYan Zheng return 1; 6175d4f98a2SYan Zheng } 6185d4f98a2SYan Zheng #endif 6195d4f98a2SYan Zheng ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); 6205d4f98a2SYan Zheng WARN_ON(!(btrfs_extent_flags(leaf, ei) & 6215d4f98a2SYan Zheng BTRFS_EXTENT_FLAG_TREE_BLOCK)); 6225d4f98a2SYan Zheng 6235d4f98a2SYan Zheng if (item_size <= sizeof(*ei) + sizeof(*bi)) { 6245d4f98a2SYan Zheng WARN_ON(item_size < sizeof(*ei) + sizeof(*bi)); 6255d4f98a2SYan Zheng return 1; 6265d4f98a2SYan Zheng } 6275d4f98a2SYan Zheng 6285d4f98a2SYan Zheng bi = (struct btrfs_tree_block_info *)(ei + 1); 6295d4f98a2SYan Zheng *ptr = (unsigned long)(bi + 1); 6305d4f98a2SYan Zheng *end = (unsigned long)ei + item_size; 6315d4f98a2SYan Zheng return 0; 6325d4f98a2SYan Zheng } 6335d4f98a2SYan Zheng 6345d4f98a2SYan Zheng /* 6355d4f98a2SYan Zheng * build backref tree for a given tree block. root of the backref tree 6365d4f98a2SYan Zheng * corresponds the tree block, leaves of the backref tree correspond 6375d4f98a2SYan Zheng * roots of b-trees that reference the tree block. 6385d4f98a2SYan Zheng * 6395d4f98a2SYan Zheng * the basic idea of this function is check backrefs of a given block 6405d4f98a2SYan Zheng * to find upper level blocks that refernece the block, and then check 6415d4f98a2SYan Zheng * bakcrefs of these upper level blocks recursively. the recursion stop 6425d4f98a2SYan Zheng * when tree root is reached or backrefs for the block is cached. 6435d4f98a2SYan Zheng * 6445d4f98a2SYan Zheng * NOTE: if we find backrefs for a block are cached, we know backrefs 6455d4f98a2SYan Zheng * for all upper level blocks that directly/indirectly reference the 6465d4f98a2SYan Zheng * block are also cached. 6475d4f98a2SYan Zheng */ 6483fd0a558SYan, Zheng static noinline_for_stack 6493fd0a558SYan, Zheng struct backref_node *build_backref_tree(struct reloc_control *rc, 6505d4f98a2SYan Zheng struct btrfs_key *node_key, 6515d4f98a2SYan Zheng int level, u64 bytenr) 6525d4f98a2SYan Zheng { 6533fd0a558SYan, Zheng struct backref_cache *cache = &rc->backref_cache; 6545d4f98a2SYan Zheng struct btrfs_path *path1; 6555d4f98a2SYan Zheng struct btrfs_path *path2; 6565d4f98a2SYan Zheng struct extent_buffer *eb; 6575d4f98a2SYan Zheng struct btrfs_root *root; 6585d4f98a2SYan Zheng struct backref_node *cur; 6595d4f98a2SYan Zheng struct backref_node *upper; 6605d4f98a2SYan Zheng struct backref_node *lower; 6615d4f98a2SYan Zheng struct backref_node *node = NULL; 6625d4f98a2SYan Zheng struct backref_node *exist = NULL; 6635d4f98a2SYan Zheng struct backref_edge *edge; 6645d4f98a2SYan Zheng struct rb_node *rb_node; 6655d4f98a2SYan Zheng struct btrfs_key key; 6665d4f98a2SYan Zheng unsigned long end; 6675d4f98a2SYan Zheng unsigned long ptr; 6685d4f98a2SYan Zheng LIST_HEAD(list); 6693fd0a558SYan, Zheng LIST_HEAD(useless); 6703fd0a558SYan, Zheng int cowonly; 6715d4f98a2SYan Zheng int ret; 6725d4f98a2SYan Zheng int err = 0; 6735d4f98a2SYan Zheng 6745d4f98a2SYan Zheng path1 = btrfs_alloc_path(); 6755d4f98a2SYan Zheng path2 = btrfs_alloc_path(); 6765d4f98a2SYan Zheng if (!path1 || !path2) { 6775d4f98a2SYan Zheng err = -ENOMEM; 6785d4f98a2SYan Zheng goto out; 6795d4f98a2SYan Zheng } 6805d4f98a2SYan Zheng 6813fd0a558SYan, Zheng node = alloc_backref_node(cache); 6825d4f98a2SYan Zheng if (!node) { 6835d4f98a2SYan Zheng err = -ENOMEM; 6845d4f98a2SYan Zheng goto out; 6855d4f98a2SYan Zheng } 6865d4f98a2SYan Zheng 6875d4f98a2SYan Zheng node->bytenr = bytenr; 6885d4f98a2SYan Zheng node->level = level; 6895d4f98a2SYan Zheng node->lowest = 1; 6905d4f98a2SYan Zheng cur = node; 6915d4f98a2SYan Zheng again: 6925d4f98a2SYan Zheng end = 0; 6935d4f98a2SYan Zheng ptr = 0; 6945d4f98a2SYan Zheng key.objectid = cur->bytenr; 6955d4f98a2SYan Zheng key.type = BTRFS_EXTENT_ITEM_KEY; 6965d4f98a2SYan Zheng key.offset = (u64)-1; 6975d4f98a2SYan Zheng 6985d4f98a2SYan Zheng path1->search_commit_root = 1; 6995d4f98a2SYan Zheng path1->skip_locking = 1; 7005d4f98a2SYan Zheng ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1, 7015d4f98a2SYan Zheng 0, 0); 7025d4f98a2SYan Zheng if (ret < 0) { 7035d4f98a2SYan Zheng err = ret; 7045d4f98a2SYan Zheng goto out; 7055d4f98a2SYan Zheng } 7065d4f98a2SYan Zheng BUG_ON(!ret || !path1->slots[0]); 7075d4f98a2SYan Zheng 7085d4f98a2SYan Zheng path1->slots[0]--; 7095d4f98a2SYan Zheng 7105d4f98a2SYan Zheng WARN_ON(cur->checked); 7115d4f98a2SYan Zheng if (!list_empty(&cur->upper)) { 7125d4f98a2SYan Zheng /* 7135d4f98a2SYan Zheng * the backref was added previously when processsing 7145d4f98a2SYan Zheng * backref of type BTRFS_TREE_BLOCK_REF_KEY 7155d4f98a2SYan Zheng */ 7165d4f98a2SYan Zheng BUG_ON(!list_is_singular(&cur->upper)); 7175d4f98a2SYan Zheng edge = list_entry(cur->upper.next, struct backref_edge, 7185d4f98a2SYan Zheng list[LOWER]); 7195d4f98a2SYan Zheng BUG_ON(!list_empty(&edge->list[UPPER])); 7205d4f98a2SYan Zheng exist = edge->node[UPPER]; 7215d4f98a2SYan Zheng /* 7225d4f98a2SYan Zheng * add the upper level block to pending list if we need 7235d4f98a2SYan Zheng * check its backrefs 7245d4f98a2SYan Zheng */ 7255d4f98a2SYan Zheng if (!exist->checked) 7265d4f98a2SYan Zheng list_add_tail(&edge->list[UPPER], &list); 7275d4f98a2SYan Zheng } else { 7285d4f98a2SYan Zheng exist = NULL; 7295d4f98a2SYan Zheng } 7305d4f98a2SYan Zheng 7315d4f98a2SYan Zheng while (1) { 7325d4f98a2SYan Zheng cond_resched(); 7335d4f98a2SYan Zheng eb = path1->nodes[0]; 7345d4f98a2SYan Zheng 7355d4f98a2SYan Zheng if (ptr >= end) { 7365d4f98a2SYan Zheng if (path1->slots[0] >= btrfs_header_nritems(eb)) { 7375d4f98a2SYan Zheng ret = btrfs_next_leaf(rc->extent_root, path1); 7385d4f98a2SYan Zheng if (ret < 0) { 7395d4f98a2SYan Zheng err = ret; 7405d4f98a2SYan Zheng goto out; 7415d4f98a2SYan Zheng } 7425d4f98a2SYan Zheng if (ret > 0) 7435d4f98a2SYan Zheng break; 7445d4f98a2SYan Zheng eb = path1->nodes[0]; 7455d4f98a2SYan Zheng } 7465d4f98a2SYan Zheng 7475d4f98a2SYan Zheng btrfs_item_key_to_cpu(eb, &key, path1->slots[0]); 7485d4f98a2SYan Zheng if (key.objectid != cur->bytenr) { 7495d4f98a2SYan Zheng WARN_ON(exist); 7505d4f98a2SYan Zheng break; 7515d4f98a2SYan Zheng } 7525d4f98a2SYan Zheng 7535d4f98a2SYan Zheng if (key.type == BTRFS_EXTENT_ITEM_KEY) { 7545d4f98a2SYan Zheng ret = find_inline_backref(eb, path1->slots[0], 7555d4f98a2SYan Zheng &ptr, &end); 7565d4f98a2SYan Zheng if (ret) 7575d4f98a2SYan Zheng goto next; 7585d4f98a2SYan Zheng } 7595d4f98a2SYan Zheng } 7605d4f98a2SYan Zheng 7615d4f98a2SYan Zheng if (ptr < end) { 7625d4f98a2SYan Zheng /* update key for inline back ref */ 7635d4f98a2SYan Zheng struct btrfs_extent_inline_ref *iref; 7645d4f98a2SYan Zheng iref = (struct btrfs_extent_inline_ref *)ptr; 7655d4f98a2SYan Zheng key.type = btrfs_extent_inline_ref_type(eb, iref); 7665d4f98a2SYan Zheng key.offset = btrfs_extent_inline_ref_offset(eb, iref); 7675d4f98a2SYan Zheng WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY && 7685d4f98a2SYan Zheng key.type != BTRFS_SHARED_BLOCK_REF_KEY); 7695d4f98a2SYan Zheng } 7705d4f98a2SYan Zheng 7715d4f98a2SYan Zheng if (exist && 7725d4f98a2SYan Zheng ((key.type == BTRFS_TREE_BLOCK_REF_KEY && 7735d4f98a2SYan Zheng exist->owner == key.offset) || 7745d4f98a2SYan Zheng (key.type == BTRFS_SHARED_BLOCK_REF_KEY && 7755d4f98a2SYan Zheng exist->bytenr == key.offset))) { 7765d4f98a2SYan Zheng exist = NULL; 7775d4f98a2SYan Zheng goto next; 7785d4f98a2SYan Zheng } 7795d4f98a2SYan Zheng 7805d4f98a2SYan Zheng #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 7815d4f98a2SYan Zheng if (key.type == BTRFS_SHARED_BLOCK_REF_KEY || 7825d4f98a2SYan Zheng key.type == BTRFS_EXTENT_REF_V0_KEY) { 7833fd0a558SYan, Zheng if (key.type == BTRFS_EXTENT_REF_V0_KEY) { 7845d4f98a2SYan Zheng struct btrfs_extent_ref_v0 *ref0; 7855d4f98a2SYan Zheng ref0 = btrfs_item_ptr(eb, path1->slots[0], 7865d4f98a2SYan Zheng struct btrfs_extent_ref_v0); 7873fd0a558SYan, Zheng if (key.objectid == key.offset) { 788046f264fSYan, Zheng root = find_tree_root(rc, eb, ref0); 7893fd0a558SYan, Zheng if (root && !should_ignore_root(root)) 7905d4f98a2SYan Zheng cur->root = root; 7915d4f98a2SYan Zheng else 7923fd0a558SYan, Zheng list_add(&cur->list, &useless); 7935d4f98a2SYan Zheng break; 7945d4f98a2SYan Zheng } 795046f264fSYan, Zheng if (is_cowonly_root(btrfs_ref_root_v0(eb, 796046f264fSYan, Zheng ref0))) 797046f264fSYan, Zheng cur->cowonly = 1; 7983fd0a558SYan, Zheng } 7995d4f98a2SYan Zheng #else 8005d4f98a2SYan Zheng BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY); 8015d4f98a2SYan Zheng if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) { 8025d4f98a2SYan Zheng #endif 8035d4f98a2SYan Zheng if (key.objectid == key.offset) { 8045d4f98a2SYan Zheng /* 8055d4f98a2SYan Zheng * only root blocks of reloc trees use 8065d4f98a2SYan Zheng * backref of this type. 8075d4f98a2SYan Zheng */ 8085d4f98a2SYan Zheng root = find_reloc_root(rc, cur->bytenr); 8095d4f98a2SYan Zheng BUG_ON(!root); 8105d4f98a2SYan Zheng cur->root = root; 8115d4f98a2SYan Zheng break; 8125d4f98a2SYan Zheng } 8135d4f98a2SYan Zheng 8143fd0a558SYan, Zheng edge = alloc_backref_edge(cache); 8155d4f98a2SYan Zheng if (!edge) { 8165d4f98a2SYan Zheng err = -ENOMEM; 8175d4f98a2SYan Zheng goto out; 8185d4f98a2SYan Zheng } 8195d4f98a2SYan Zheng rb_node = tree_search(&cache->rb_root, key.offset); 8205d4f98a2SYan Zheng if (!rb_node) { 8213fd0a558SYan, Zheng upper = alloc_backref_node(cache); 8225d4f98a2SYan Zheng if (!upper) { 8233fd0a558SYan, Zheng free_backref_edge(cache, edge); 8245d4f98a2SYan Zheng err = -ENOMEM; 8255d4f98a2SYan Zheng goto out; 8265d4f98a2SYan Zheng } 8275d4f98a2SYan Zheng upper->bytenr = key.offset; 8285d4f98a2SYan Zheng upper->level = cur->level + 1; 8295d4f98a2SYan Zheng /* 8305d4f98a2SYan Zheng * backrefs for the upper level block isn't 8315d4f98a2SYan Zheng * cached, add the block to pending list 8325d4f98a2SYan Zheng */ 8335d4f98a2SYan Zheng list_add_tail(&edge->list[UPPER], &list); 8345d4f98a2SYan Zheng } else { 8355d4f98a2SYan Zheng upper = rb_entry(rb_node, struct backref_node, 8365d4f98a2SYan Zheng rb_node); 8373fd0a558SYan, Zheng BUG_ON(!upper->checked); 8385d4f98a2SYan Zheng INIT_LIST_HEAD(&edge->list[UPPER]); 8395d4f98a2SYan Zheng } 8403fd0a558SYan, Zheng list_add_tail(&edge->list[LOWER], &cur->upper); 8415d4f98a2SYan Zheng edge->node[LOWER] = cur; 8423fd0a558SYan, Zheng edge->node[UPPER] = upper; 8435d4f98a2SYan Zheng 8445d4f98a2SYan Zheng goto next; 8455d4f98a2SYan Zheng } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) { 8465d4f98a2SYan Zheng goto next; 8475d4f98a2SYan Zheng } 8485d4f98a2SYan Zheng 8495d4f98a2SYan Zheng /* key.type == BTRFS_TREE_BLOCK_REF_KEY */ 8505d4f98a2SYan Zheng root = read_fs_root(rc->extent_root->fs_info, key.offset); 8515d4f98a2SYan Zheng if (IS_ERR(root)) { 8525d4f98a2SYan Zheng err = PTR_ERR(root); 8535d4f98a2SYan Zheng goto out; 8545d4f98a2SYan Zheng } 8555d4f98a2SYan Zheng 8563fd0a558SYan, Zheng if (!root->ref_cows) 8573fd0a558SYan, Zheng cur->cowonly = 1; 8583fd0a558SYan, Zheng 8595d4f98a2SYan Zheng if (btrfs_root_level(&root->root_item) == cur->level) { 8605d4f98a2SYan Zheng /* tree root */ 8615d4f98a2SYan Zheng BUG_ON(btrfs_root_bytenr(&root->root_item) != 8625d4f98a2SYan Zheng cur->bytenr); 8633fd0a558SYan, Zheng if (should_ignore_root(root)) 8643fd0a558SYan, Zheng list_add(&cur->list, &useless); 8653fd0a558SYan, Zheng else 8665d4f98a2SYan Zheng cur->root = root; 8675d4f98a2SYan Zheng break; 8685d4f98a2SYan Zheng } 8695d4f98a2SYan Zheng 8705d4f98a2SYan Zheng level = cur->level + 1; 8715d4f98a2SYan Zheng 8725d4f98a2SYan Zheng /* 8735d4f98a2SYan Zheng * searching the tree to find upper level blocks 8745d4f98a2SYan Zheng * reference the block. 8755d4f98a2SYan Zheng */ 8765d4f98a2SYan Zheng path2->search_commit_root = 1; 8775d4f98a2SYan Zheng path2->skip_locking = 1; 8785d4f98a2SYan Zheng path2->lowest_level = level; 8795d4f98a2SYan Zheng ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0); 8805d4f98a2SYan Zheng path2->lowest_level = 0; 8815d4f98a2SYan Zheng if (ret < 0) { 8825d4f98a2SYan Zheng err = ret; 8835d4f98a2SYan Zheng goto out; 8845d4f98a2SYan Zheng } 88533c66f43SYan Zheng if (ret > 0 && path2->slots[level] > 0) 88633c66f43SYan Zheng path2->slots[level]--; 8875d4f98a2SYan Zheng 8885d4f98a2SYan Zheng eb = path2->nodes[level]; 8895d4f98a2SYan Zheng WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) != 8905d4f98a2SYan Zheng cur->bytenr); 8915d4f98a2SYan Zheng 8925d4f98a2SYan Zheng lower = cur; 8935d4f98a2SYan Zheng for (; level < BTRFS_MAX_LEVEL; level++) { 8945d4f98a2SYan Zheng if (!path2->nodes[level]) { 8955d4f98a2SYan Zheng BUG_ON(btrfs_root_bytenr(&root->root_item) != 8965d4f98a2SYan Zheng lower->bytenr); 8973fd0a558SYan, Zheng if (should_ignore_root(root)) 8983fd0a558SYan, Zheng list_add(&lower->list, &useless); 8993fd0a558SYan, Zheng else 9005d4f98a2SYan Zheng lower->root = root; 9015d4f98a2SYan Zheng break; 9025d4f98a2SYan Zheng } 9035d4f98a2SYan Zheng 9043fd0a558SYan, Zheng edge = alloc_backref_edge(cache); 9055d4f98a2SYan Zheng if (!edge) { 9065d4f98a2SYan Zheng err = -ENOMEM; 9075d4f98a2SYan Zheng goto out; 9085d4f98a2SYan Zheng } 9095d4f98a2SYan Zheng 9105d4f98a2SYan Zheng eb = path2->nodes[level]; 9115d4f98a2SYan Zheng rb_node = tree_search(&cache->rb_root, eb->start); 9125d4f98a2SYan Zheng if (!rb_node) { 9133fd0a558SYan, Zheng upper = alloc_backref_node(cache); 9145d4f98a2SYan Zheng if (!upper) { 9153fd0a558SYan, Zheng free_backref_edge(cache, edge); 9165d4f98a2SYan Zheng err = -ENOMEM; 9175d4f98a2SYan Zheng goto out; 9185d4f98a2SYan Zheng } 9195d4f98a2SYan Zheng upper->bytenr = eb->start; 9205d4f98a2SYan Zheng upper->owner = btrfs_header_owner(eb); 9215d4f98a2SYan Zheng upper->level = lower->level + 1; 9223fd0a558SYan, Zheng if (!root->ref_cows) 9233fd0a558SYan, Zheng upper->cowonly = 1; 9245d4f98a2SYan Zheng 9255d4f98a2SYan Zheng /* 9265d4f98a2SYan Zheng * if we know the block isn't shared 9275d4f98a2SYan Zheng * we can void checking its backrefs. 9285d4f98a2SYan Zheng */ 9295d4f98a2SYan Zheng if (btrfs_block_can_be_shared(root, eb)) 9305d4f98a2SYan Zheng upper->checked = 0; 9315d4f98a2SYan Zheng else 9325d4f98a2SYan Zheng upper->checked = 1; 9335d4f98a2SYan Zheng 9345d4f98a2SYan Zheng /* 9355d4f98a2SYan Zheng * add the block to pending list if we 9365d4f98a2SYan Zheng * need check its backrefs. only block 9375d4f98a2SYan Zheng * at 'cur->level + 1' is added to the 9385d4f98a2SYan Zheng * tail of pending list. this guarantees 9395d4f98a2SYan Zheng * we check backrefs from lower level 9405d4f98a2SYan Zheng * blocks to upper level blocks. 9415d4f98a2SYan Zheng */ 9425d4f98a2SYan Zheng if (!upper->checked && 9435d4f98a2SYan Zheng level == cur->level + 1) { 9445d4f98a2SYan Zheng list_add_tail(&edge->list[UPPER], 9455d4f98a2SYan Zheng &list); 9465d4f98a2SYan Zheng } else 9475d4f98a2SYan Zheng INIT_LIST_HEAD(&edge->list[UPPER]); 9485d4f98a2SYan Zheng } else { 9495d4f98a2SYan Zheng upper = rb_entry(rb_node, struct backref_node, 9505d4f98a2SYan Zheng rb_node); 9515d4f98a2SYan Zheng BUG_ON(!upper->checked); 9525d4f98a2SYan Zheng INIT_LIST_HEAD(&edge->list[UPPER]); 9533fd0a558SYan, Zheng if (!upper->owner) 9543fd0a558SYan, Zheng upper->owner = btrfs_header_owner(eb); 9555d4f98a2SYan Zheng } 9565d4f98a2SYan Zheng list_add_tail(&edge->list[LOWER], &lower->upper); 9575d4f98a2SYan Zheng edge->node[LOWER] = lower; 9583fd0a558SYan, Zheng edge->node[UPPER] = upper; 9595d4f98a2SYan Zheng 9605d4f98a2SYan Zheng if (rb_node) 9615d4f98a2SYan Zheng break; 9625d4f98a2SYan Zheng lower = upper; 9635d4f98a2SYan Zheng upper = NULL; 9645d4f98a2SYan Zheng } 9655d4f98a2SYan Zheng btrfs_release_path(root, path2); 9665d4f98a2SYan Zheng next: 9675d4f98a2SYan Zheng if (ptr < end) { 9685d4f98a2SYan Zheng ptr += btrfs_extent_inline_ref_size(key.type); 9695d4f98a2SYan Zheng if (ptr >= end) { 9705d4f98a2SYan Zheng WARN_ON(ptr > end); 9715d4f98a2SYan Zheng ptr = 0; 9725d4f98a2SYan Zheng end = 0; 9735d4f98a2SYan Zheng } 9745d4f98a2SYan Zheng } 9755d4f98a2SYan Zheng if (ptr >= end) 9765d4f98a2SYan Zheng path1->slots[0]++; 9775d4f98a2SYan Zheng } 9785d4f98a2SYan Zheng btrfs_release_path(rc->extent_root, path1); 9795d4f98a2SYan Zheng 9805d4f98a2SYan Zheng cur->checked = 1; 9815d4f98a2SYan Zheng WARN_ON(exist); 9825d4f98a2SYan Zheng 9835d4f98a2SYan Zheng /* the pending list isn't empty, take the first block to process */ 9845d4f98a2SYan Zheng if (!list_empty(&list)) { 9855d4f98a2SYan Zheng edge = list_entry(list.next, struct backref_edge, list[UPPER]); 9865d4f98a2SYan Zheng list_del_init(&edge->list[UPPER]); 9875d4f98a2SYan Zheng cur = edge->node[UPPER]; 9885d4f98a2SYan Zheng goto again; 9895d4f98a2SYan Zheng } 9905d4f98a2SYan Zheng 9915d4f98a2SYan Zheng /* 9925d4f98a2SYan Zheng * everything goes well, connect backref nodes and insert backref nodes 9935d4f98a2SYan Zheng * into the cache. 9945d4f98a2SYan Zheng */ 9955d4f98a2SYan Zheng BUG_ON(!node->checked); 9963fd0a558SYan, Zheng cowonly = node->cowonly; 9973fd0a558SYan, Zheng if (!cowonly) { 9983fd0a558SYan, Zheng rb_node = tree_insert(&cache->rb_root, node->bytenr, 9993fd0a558SYan, Zheng &node->rb_node); 10005d4f98a2SYan Zheng BUG_ON(rb_node); 10013fd0a558SYan, Zheng list_add_tail(&node->lower, &cache->leaves); 10023fd0a558SYan, Zheng } 10035d4f98a2SYan Zheng 10045d4f98a2SYan Zheng list_for_each_entry(edge, &node->upper, list[LOWER]) 10055d4f98a2SYan Zheng list_add_tail(&edge->list[UPPER], &list); 10065d4f98a2SYan Zheng 10075d4f98a2SYan Zheng while (!list_empty(&list)) { 10085d4f98a2SYan Zheng edge = list_entry(list.next, struct backref_edge, list[UPPER]); 10095d4f98a2SYan Zheng list_del_init(&edge->list[UPPER]); 10105d4f98a2SYan Zheng upper = edge->node[UPPER]; 10113fd0a558SYan, Zheng if (upper->detached) { 10123fd0a558SYan, Zheng list_del(&edge->list[LOWER]); 10133fd0a558SYan, Zheng lower = edge->node[LOWER]; 10143fd0a558SYan, Zheng free_backref_edge(cache, edge); 10153fd0a558SYan, Zheng if (list_empty(&lower->upper)) 10163fd0a558SYan, Zheng list_add(&lower->list, &useless); 10173fd0a558SYan, Zheng continue; 10183fd0a558SYan, Zheng } 10195d4f98a2SYan Zheng 10205d4f98a2SYan Zheng if (!RB_EMPTY_NODE(&upper->rb_node)) { 10215d4f98a2SYan Zheng if (upper->lowest) { 10225d4f98a2SYan Zheng list_del_init(&upper->lower); 10235d4f98a2SYan Zheng upper->lowest = 0; 10245d4f98a2SYan Zheng } 10255d4f98a2SYan Zheng 10265d4f98a2SYan Zheng list_add_tail(&edge->list[UPPER], &upper->lower); 10275d4f98a2SYan Zheng continue; 10285d4f98a2SYan Zheng } 10295d4f98a2SYan Zheng 10305d4f98a2SYan Zheng BUG_ON(!upper->checked); 10313fd0a558SYan, Zheng BUG_ON(cowonly != upper->cowonly); 10323fd0a558SYan, Zheng if (!cowonly) { 10335d4f98a2SYan Zheng rb_node = tree_insert(&cache->rb_root, upper->bytenr, 10345d4f98a2SYan Zheng &upper->rb_node); 10355d4f98a2SYan Zheng BUG_ON(rb_node); 10363fd0a558SYan, Zheng } 10375d4f98a2SYan Zheng 10385d4f98a2SYan Zheng list_add_tail(&edge->list[UPPER], &upper->lower); 10395d4f98a2SYan Zheng 10405d4f98a2SYan Zheng list_for_each_entry(edge, &upper->upper, list[LOWER]) 10415d4f98a2SYan Zheng list_add_tail(&edge->list[UPPER], &list); 10425d4f98a2SYan Zheng } 10433fd0a558SYan, Zheng /* 10443fd0a558SYan, Zheng * process useless backref nodes. backref nodes for tree leaves 10453fd0a558SYan, Zheng * are deleted from the cache. backref nodes for upper level 10463fd0a558SYan, Zheng * tree blocks are left in the cache to avoid unnecessary backref 10473fd0a558SYan, Zheng * lookup. 10483fd0a558SYan, Zheng */ 10493fd0a558SYan, Zheng while (!list_empty(&useless)) { 10503fd0a558SYan, Zheng upper = list_entry(useless.next, struct backref_node, list); 10513fd0a558SYan, Zheng list_del_init(&upper->list); 10523fd0a558SYan, Zheng BUG_ON(!list_empty(&upper->upper)); 10533fd0a558SYan, Zheng if (upper == node) 10543fd0a558SYan, Zheng node = NULL; 10553fd0a558SYan, Zheng if (upper->lowest) { 10563fd0a558SYan, Zheng list_del_init(&upper->lower); 10573fd0a558SYan, Zheng upper->lowest = 0; 10583fd0a558SYan, Zheng } 10593fd0a558SYan, Zheng while (!list_empty(&upper->lower)) { 10603fd0a558SYan, Zheng edge = list_entry(upper->lower.next, 10613fd0a558SYan, Zheng struct backref_edge, list[UPPER]); 10623fd0a558SYan, Zheng list_del(&edge->list[UPPER]); 10633fd0a558SYan, Zheng list_del(&edge->list[LOWER]); 10643fd0a558SYan, Zheng lower = edge->node[LOWER]; 10653fd0a558SYan, Zheng free_backref_edge(cache, edge); 10663fd0a558SYan, Zheng 10673fd0a558SYan, Zheng if (list_empty(&lower->upper)) 10683fd0a558SYan, Zheng list_add(&lower->list, &useless); 10693fd0a558SYan, Zheng } 10703fd0a558SYan, Zheng __mark_block_processed(rc, upper); 10713fd0a558SYan, Zheng if (upper->level > 0) { 10723fd0a558SYan, Zheng list_add(&upper->list, &cache->detached); 10733fd0a558SYan, Zheng upper->detached = 1; 10743fd0a558SYan, Zheng } else { 10753fd0a558SYan, Zheng rb_erase(&upper->rb_node, &cache->rb_root); 10763fd0a558SYan, Zheng free_backref_node(cache, upper); 10773fd0a558SYan, Zheng } 10783fd0a558SYan, Zheng } 10795d4f98a2SYan Zheng out: 10805d4f98a2SYan Zheng btrfs_free_path(path1); 10815d4f98a2SYan Zheng btrfs_free_path(path2); 10825d4f98a2SYan Zheng if (err) { 10833fd0a558SYan, Zheng while (!list_empty(&useless)) { 10843fd0a558SYan, Zheng lower = list_entry(useless.next, 10853fd0a558SYan, Zheng struct backref_node, upper); 10863fd0a558SYan, Zheng list_del_init(&lower->upper); 10873fd0a558SYan, Zheng } 10885d4f98a2SYan Zheng upper = node; 10893fd0a558SYan, Zheng INIT_LIST_HEAD(&list); 10905d4f98a2SYan Zheng while (upper) { 10915d4f98a2SYan Zheng if (RB_EMPTY_NODE(&upper->rb_node)) { 10925d4f98a2SYan Zheng list_splice_tail(&upper->upper, &list); 10933fd0a558SYan, Zheng free_backref_node(cache, upper); 10945d4f98a2SYan Zheng } 10955d4f98a2SYan Zheng 10965d4f98a2SYan Zheng if (list_empty(&list)) 10975d4f98a2SYan Zheng break; 10985d4f98a2SYan Zheng 10995d4f98a2SYan Zheng edge = list_entry(list.next, struct backref_edge, 11005d4f98a2SYan Zheng list[LOWER]); 11013fd0a558SYan, Zheng list_del(&edge->list[LOWER]); 11025d4f98a2SYan Zheng upper = edge->node[UPPER]; 11033fd0a558SYan, Zheng free_backref_edge(cache, edge); 11045d4f98a2SYan Zheng } 11055d4f98a2SYan Zheng return ERR_PTR(err); 11065d4f98a2SYan Zheng } 11073fd0a558SYan, Zheng BUG_ON(node && node->detached); 11085d4f98a2SYan Zheng return node; 11095d4f98a2SYan Zheng } 11105d4f98a2SYan Zheng 11115d4f98a2SYan Zheng /* 11123fd0a558SYan, Zheng * helper to add backref node for the newly created snapshot. 11133fd0a558SYan, Zheng * the backref node is created by cloning backref node that 11143fd0a558SYan, Zheng * corresponds to root of source tree 11153fd0a558SYan, Zheng */ 11163fd0a558SYan, Zheng static int clone_backref_node(struct btrfs_trans_handle *trans, 11173fd0a558SYan, Zheng struct reloc_control *rc, 11183fd0a558SYan, Zheng struct btrfs_root *src, 11193fd0a558SYan, Zheng struct btrfs_root *dest) 11203fd0a558SYan, Zheng { 11213fd0a558SYan, Zheng struct btrfs_root *reloc_root = src->reloc_root; 11223fd0a558SYan, Zheng struct backref_cache *cache = &rc->backref_cache; 11233fd0a558SYan, Zheng struct backref_node *node = NULL; 11243fd0a558SYan, Zheng struct backref_node *new_node; 11253fd0a558SYan, Zheng struct backref_edge *edge; 11263fd0a558SYan, Zheng struct backref_edge *new_edge; 11273fd0a558SYan, Zheng struct rb_node *rb_node; 11283fd0a558SYan, Zheng 11293fd0a558SYan, Zheng if (cache->last_trans > 0) 11303fd0a558SYan, Zheng update_backref_cache(trans, cache); 11313fd0a558SYan, Zheng 11323fd0a558SYan, Zheng rb_node = tree_search(&cache->rb_root, src->commit_root->start); 11333fd0a558SYan, Zheng if (rb_node) { 11343fd0a558SYan, Zheng node = rb_entry(rb_node, struct backref_node, rb_node); 11353fd0a558SYan, Zheng if (node->detached) 11363fd0a558SYan, Zheng node = NULL; 11373fd0a558SYan, Zheng else 11383fd0a558SYan, Zheng BUG_ON(node->new_bytenr != reloc_root->node->start); 11393fd0a558SYan, Zheng } 11403fd0a558SYan, Zheng 11413fd0a558SYan, Zheng if (!node) { 11423fd0a558SYan, Zheng rb_node = tree_search(&cache->rb_root, 11433fd0a558SYan, Zheng reloc_root->commit_root->start); 11443fd0a558SYan, Zheng if (rb_node) { 11453fd0a558SYan, Zheng node = rb_entry(rb_node, struct backref_node, 11463fd0a558SYan, Zheng rb_node); 11473fd0a558SYan, Zheng BUG_ON(node->detached); 11483fd0a558SYan, Zheng } 11493fd0a558SYan, Zheng } 11503fd0a558SYan, Zheng 11513fd0a558SYan, Zheng if (!node) 11523fd0a558SYan, Zheng return 0; 11533fd0a558SYan, Zheng 11543fd0a558SYan, Zheng new_node = alloc_backref_node(cache); 11553fd0a558SYan, Zheng if (!new_node) 11563fd0a558SYan, Zheng return -ENOMEM; 11573fd0a558SYan, Zheng 11583fd0a558SYan, Zheng new_node->bytenr = dest->node->start; 11593fd0a558SYan, Zheng new_node->level = node->level; 11603fd0a558SYan, Zheng new_node->lowest = node->lowest; 11613fd0a558SYan, Zheng new_node->root = dest; 11623fd0a558SYan, Zheng 11633fd0a558SYan, Zheng if (!node->lowest) { 11643fd0a558SYan, Zheng list_for_each_entry(edge, &node->lower, list[UPPER]) { 11653fd0a558SYan, Zheng new_edge = alloc_backref_edge(cache); 11663fd0a558SYan, Zheng if (!new_edge) 11673fd0a558SYan, Zheng goto fail; 11683fd0a558SYan, Zheng 11693fd0a558SYan, Zheng new_edge->node[UPPER] = new_node; 11703fd0a558SYan, Zheng new_edge->node[LOWER] = edge->node[LOWER]; 11713fd0a558SYan, Zheng list_add_tail(&new_edge->list[UPPER], 11723fd0a558SYan, Zheng &new_node->lower); 11733fd0a558SYan, Zheng } 11743fd0a558SYan, Zheng } 11753fd0a558SYan, Zheng 11763fd0a558SYan, Zheng rb_node = tree_insert(&cache->rb_root, new_node->bytenr, 11773fd0a558SYan, Zheng &new_node->rb_node); 11783fd0a558SYan, Zheng BUG_ON(rb_node); 11793fd0a558SYan, Zheng 11803fd0a558SYan, Zheng if (!new_node->lowest) { 11813fd0a558SYan, Zheng list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) { 11823fd0a558SYan, Zheng list_add_tail(&new_edge->list[LOWER], 11833fd0a558SYan, Zheng &new_edge->node[LOWER]->upper); 11843fd0a558SYan, Zheng } 11853fd0a558SYan, Zheng } 11863fd0a558SYan, Zheng return 0; 11873fd0a558SYan, Zheng fail: 11883fd0a558SYan, Zheng while (!list_empty(&new_node->lower)) { 11893fd0a558SYan, Zheng new_edge = list_entry(new_node->lower.next, 11903fd0a558SYan, Zheng struct backref_edge, list[UPPER]); 11913fd0a558SYan, Zheng list_del(&new_edge->list[UPPER]); 11923fd0a558SYan, Zheng free_backref_edge(cache, new_edge); 11933fd0a558SYan, Zheng } 11943fd0a558SYan, Zheng free_backref_node(cache, new_node); 11953fd0a558SYan, Zheng return -ENOMEM; 11963fd0a558SYan, Zheng } 11973fd0a558SYan, Zheng 11983fd0a558SYan, Zheng /* 11995d4f98a2SYan Zheng * helper to add 'address of tree root -> reloc tree' mapping 12005d4f98a2SYan Zheng */ 12015d4f98a2SYan Zheng static int __add_reloc_root(struct btrfs_root *root) 12025d4f98a2SYan Zheng { 12035d4f98a2SYan Zheng struct rb_node *rb_node; 12045d4f98a2SYan Zheng struct mapping_node *node; 12055d4f98a2SYan Zheng struct reloc_control *rc = root->fs_info->reloc_ctl; 12065d4f98a2SYan Zheng 12075d4f98a2SYan Zheng node = kmalloc(sizeof(*node), GFP_NOFS); 12085d4f98a2SYan Zheng BUG_ON(!node); 12095d4f98a2SYan Zheng 12105d4f98a2SYan Zheng node->bytenr = root->node->start; 12115d4f98a2SYan Zheng node->data = root; 12125d4f98a2SYan Zheng 12135d4f98a2SYan Zheng spin_lock(&rc->reloc_root_tree.lock); 12145d4f98a2SYan Zheng rb_node = tree_insert(&rc->reloc_root_tree.rb_root, 12155d4f98a2SYan Zheng node->bytenr, &node->rb_node); 12165d4f98a2SYan Zheng spin_unlock(&rc->reloc_root_tree.lock); 12175d4f98a2SYan Zheng BUG_ON(rb_node); 12185d4f98a2SYan Zheng 12195d4f98a2SYan Zheng list_add_tail(&root->root_list, &rc->reloc_roots); 12205d4f98a2SYan Zheng return 0; 12215d4f98a2SYan Zheng } 12225d4f98a2SYan Zheng 12235d4f98a2SYan Zheng /* 12245d4f98a2SYan Zheng * helper to update/delete the 'address of tree root -> reloc tree' 12255d4f98a2SYan Zheng * mapping 12265d4f98a2SYan Zheng */ 12275d4f98a2SYan Zheng static int __update_reloc_root(struct btrfs_root *root, int del) 12285d4f98a2SYan Zheng { 12295d4f98a2SYan Zheng struct rb_node *rb_node; 12305d4f98a2SYan Zheng struct mapping_node *node = NULL; 12315d4f98a2SYan Zheng struct reloc_control *rc = root->fs_info->reloc_ctl; 12325d4f98a2SYan Zheng 12335d4f98a2SYan Zheng spin_lock(&rc->reloc_root_tree.lock); 12345d4f98a2SYan Zheng rb_node = tree_search(&rc->reloc_root_tree.rb_root, 12355d4f98a2SYan Zheng root->commit_root->start); 12365d4f98a2SYan Zheng if (rb_node) { 12375d4f98a2SYan Zheng node = rb_entry(rb_node, struct mapping_node, rb_node); 12385d4f98a2SYan Zheng rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root); 12395d4f98a2SYan Zheng } 12405d4f98a2SYan Zheng spin_unlock(&rc->reloc_root_tree.lock); 12415d4f98a2SYan Zheng 12425d4f98a2SYan Zheng BUG_ON((struct btrfs_root *)node->data != root); 12435d4f98a2SYan Zheng 12445d4f98a2SYan Zheng if (!del) { 12455d4f98a2SYan Zheng spin_lock(&rc->reloc_root_tree.lock); 12465d4f98a2SYan Zheng node->bytenr = root->node->start; 12475d4f98a2SYan Zheng rb_node = tree_insert(&rc->reloc_root_tree.rb_root, 12485d4f98a2SYan Zheng node->bytenr, &node->rb_node); 12495d4f98a2SYan Zheng spin_unlock(&rc->reloc_root_tree.lock); 12505d4f98a2SYan Zheng BUG_ON(rb_node); 12515d4f98a2SYan Zheng } else { 12525d4f98a2SYan Zheng list_del_init(&root->root_list); 12535d4f98a2SYan Zheng kfree(node); 12545d4f98a2SYan Zheng } 12555d4f98a2SYan Zheng return 0; 12565d4f98a2SYan Zheng } 12575d4f98a2SYan Zheng 12583fd0a558SYan, Zheng static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans, 12593fd0a558SYan, Zheng struct btrfs_root *root, u64 objectid) 12605d4f98a2SYan Zheng { 12615d4f98a2SYan Zheng struct btrfs_root *reloc_root; 12625d4f98a2SYan Zheng struct extent_buffer *eb; 12635d4f98a2SYan Zheng struct btrfs_root_item *root_item; 12645d4f98a2SYan Zheng struct btrfs_key root_key; 12655d4f98a2SYan Zheng int ret; 12665d4f98a2SYan Zheng 12675d4f98a2SYan Zheng root_item = kmalloc(sizeof(*root_item), GFP_NOFS); 12685d4f98a2SYan Zheng BUG_ON(!root_item); 12695d4f98a2SYan Zheng 12705d4f98a2SYan Zheng root_key.objectid = BTRFS_TREE_RELOC_OBJECTID; 12715d4f98a2SYan Zheng root_key.type = BTRFS_ROOT_ITEM_KEY; 12723fd0a558SYan, Zheng root_key.offset = objectid; 12735d4f98a2SYan Zheng 12743fd0a558SYan, Zheng if (root->root_key.objectid == objectid) { 12753fd0a558SYan, Zheng /* called by btrfs_init_reloc_root */ 12765d4f98a2SYan Zheng ret = btrfs_copy_root(trans, root, root->commit_root, &eb, 12775d4f98a2SYan Zheng BTRFS_TREE_RELOC_OBJECTID); 12785d4f98a2SYan Zheng BUG_ON(ret); 12795d4f98a2SYan Zheng 12803fd0a558SYan, Zheng btrfs_set_root_last_snapshot(&root->root_item, 12813fd0a558SYan, Zheng trans->transid - 1); 12823fd0a558SYan, Zheng } else { 12833fd0a558SYan, Zheng /* 12843fd0a558SYan, Zheng * called by btrfs_reloc_post_snapshot_hook. 12853fd0a558SYan, Zheng * the source tree is a reloc tree, all tree blocks 12863fd0a558SYan, Zheng * modified after it was created have RELOC flag 12873fd0a558SYan, Zheng * set in their headers. so it's OK to not update 12883fd0a558SYan, Zheng * the 'last_snapshot'. 12893fd0a558SYan, Zheng */ 12903fd0a558SYan, Zheng ret = btrfs_copy_root(trans, root, root->node, &eb, 12913fd0a558SYan, Zheng BTRFS_TREE_RELOC_OBJECTID); 12923fd0a558SYan, Zheng BUG_ON(ret); 12933fd0a558SYan, Zheng } 12943fd0a558SYan, Zheng 12955d4f98a2SYan Zheng memcpy(root_item, &root->root_item, sizeof(*root_item)); 12965d4f98a2SYan Zheng btrfs_set_root_bytenr(root_item, eb->start); 12975d4f98a2SYan Zheng btrfs_set_root_level(root_item, btrfs_header_level(eb)); 12985d4f98a2SYan Zheng btrfs_set_root_generation(root_item, trans->transid); 12993fd0a558SYan, Zheng 13003fd0a558SYan, Zheng if (root->root_key.objectid == objectid) { 13013fd0a558SYan, Zheng btrfs_set_root_refs(root_item, 0); 13023fd0a558SYan, Zheng memset(&root_item->drop_progress, 0, 13033fd0a558SYan, Zheng sizeof(struct btrfs_disk_key)); 13045d4f98a2SYan Zheng root_item->drop_level = 0; 13053fd0a558SYan, Zheng } 13065d4f98a2SYan Zheng 13075d4f98a2SYan Zheng btrfs_tree_unlock(eb); 13085d4f98a2SYan Zheng free_extent_buffer(eb); 13095d4f98a2SYan Zheng 13105d4f98a2SYan Zheng ret = btrfs_insert_root(trans, root->fs_info->tree_root, 13115d4f98a2SYan Zheng &root_key, root_item); 13125d4f98a2SYan Zheng BUG_ON(ret); 13135d4f98a2SYan Zheng kfree(root_item); 13145d4f98a2SYan Zheng 13155d4f98a2SYan Zheng reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root, 13165d4f98a2SYan Zheng &root_key); 13175d4f98a2SYan Zheng BUG_ON(IS_ERR(reloc_root)); 13185d4f98a2SYan Zheng reloc_root->last_trans = trans->transid; 13193fd0a558SYan, Zheng return reloc_root; 13203fd0a558SYan, Zheng } 13213fd0a558SYan, Zheng 13223fd0a558SYan, Zheng /* 13233fd0a558SYan, Zheng * create reloc tree for a given fs tree. reloc tree is just a 13243fd0a558SYan, Zheng * snapshot of the fs tree with special root objectid. 13253fd0a558SYan, Zheng */ 13263fd0a558SYan, Zheng int btrfs_init_reloc_root(struct btrfs_trans_handle *trans, 13273fd0a558SYan, Zheng struct btrfs_root *root) 13283fd0a558SYan, Zheng { 13293fd0a558SYan, Zheng struct btrfs_root *reloc_root; 13303fd0a558SYan, Zheng struct reloc_control *rc = root->fs_info->reloc_ctl; 13313fd0a558SYan, Zheng int clear_rsv = 0; 13323fd0a558SYan, Zheng 13333fd0a558SYan, Zheng if (root->reloc_root) { 13343fd0a558SYan, Zheng reloc_root = root->reloc_root; 13353fd0a558SYan, Zheng reloc_root->last_trans = trans->transid; 13363fd0a558SYan, Zheng return 0; 13373fd0a558SYan, Zheng } 13383fd0a558SYan, Zheng 13393fd0a558SYan, Zheng if (!rc || !rc->create_reloc_tree || 13403fd0a558SYan, Zheng root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) 13413fd0a558SYan, Zheng return 0; 13423fd0a558SYan, Zheng 13433fd0a558SYan, Zheng if (!trans->block_rsv) { 13443fd0a558SYan, Zheng trans->block_rsv = rc->block_rsv; 13453fd0a558SYan, Zheng clear_rsv = 1; 13463fd0a558SYan, Zheng } 13473fd0a558SYan, Zheng reloc_root = create_reloc_root(trans, root, root->root_key.objectid); 13483fd0a558SYan, Zheng if (clear_rsv) 13493fd0a558SYan, Zheng trans->block_rsv = NULL; 13505d4f98a2SYan Zheng 13515d4f98a2SYan Zheng __add_reloc_root(reloc_root); 13525d4f98a2SYan Zheng root->reloc_root = reloc_root; 13535d4f98a2SYan Zheng return 0; 13545d4f98a2SYan Zheng } 13555d4f98a2SYan Zheng 13565d4f98a2SYan Zheng /* 13575d4f98a2SYan Zheng * update root item of reloc tree 13585d4f98a2SYan Zheng */ 13595d4f98a2SYan Zheng int btrfs_update_reloc_root(struct btrfs_trans_handle *trans, 13605d4f98a2SYan Zheng struct btrfs_root *root) 13615d4f98a2SYan Zheng { 13625d4f98a2SYan Zheng struct btrfs_root *reloc_root; 13635d4f98a2SYan Zheng struct btrfs_root_item *root_item; 13645d4f98a2SYan Zheng int del = 0; 13655d4f98a2SYan Zheng int ret; 13665d4f98a2SYan Zheng 13675d4f98a2SYan Zheng if (!root->reloc_root) 13685d4f98a2SYan Zheng return 0; 13695d4f98a2SYan Zheng 13705d4f98a2SYan Zheng reloc_root = root->reloc_root; 13715d4f98a2SYan Zheng root_item = &reloc_root->root_item; 13725d4f98a2SYan Zheng 13733fd0a558SYan, Zheng if (root->fs_info->reloc_ctl->merge_reloc_tree && 13743fd0a558SYan, Zheng btrfs_root_refs(root_item) == 0) { 13755d4f98a2SYan Zheng root->reloc_root = NULL; 13765d4f98a2SYan Zheng del = 1; 13775d4f98a2SYan Zheng } 13785d4f98a2SYan Zheng 13795d4f98a2SYan Zheng __update_reloc_root(reloc_root, del); 13805d4f98a2SYan Zheng 13815d4f98a2SYan Zheng if (reloc_root->commit_root != reloc_root->node) { 13825d4f98a2SYan Zheng btrfs_set_root_node(root_item, reloc_root->node); 13835d4f98a2SYan Zheng free_extent_buffer(reloc_root->commit_root); 13845d4f98a2SYan Zheng reloc_root->commit_root = btrfs_root_node(reloc_root); 13855d4f98a2SYan Zheng } 13865d4f98a2SYan Zheng 13875d4f98a2SYan Zheng ret = btrfs_update_root(trans, root->fs_info->tree_root, 13885d4f98a2SYan Zheng &reloc_root->root_key, root_item); 13895d4f98a2SYan Zheng BUG_ON(ret); 13905d4f98a2SYan Zheng return 0; 13915d4f98a2SYan Zheng } 13925d4f98a2SYan Zheng 13935d4f98a2SYan Zheng /* 13945d4f98a2SYan Zheng * helper to find first cached inode with inode number >= objectid 13955d4f98a2SYan Zheng * in a subvolume 13965d4f98a2SYan Zheng */ 13975d4f98a2SYan Zheng static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid) 13985d4f98a2SYan Zheng { 13995d4f98a2SYan Zheng struct rb_node *node; 14005d4f98a2SYan Zheng struct rb_node *prev; 14015d4f98a2SYan Zheng struct btrfs_inode *entry; 14025d4f98a2SYan Zheng struct inode *inode; 14035d4f98a2SYan Zheng 14045d4f98a2SYan Zheng spin_lock(&root->inode_lock); 14055d4f98a2SYan Zheng again: 14065d4f98a2SYan Zheng node = root->inode_tree.rb_node; 14075d4f98a2SYan Zheng prev = NULL; 14085d4f98a2SYan Zheng while (node) { 14095d4f98a2SYan Zheng prev = node; 14105d4f98a2SYan Zheng entry = rb_entry(node, struct btrfs_inode, rb_node); 14115d4f98a2SYan Zheng 14125d4f98a2SYan Zheng if (objectid < entry->vfs_inode.i_ino) 14135d4f98a2SYan Zheng node = node->rb_left; 14145d4f98a2SYan Zheng else if (objectid > entry->vfs_inode.i_ino) 14155d4f98a2SYan Zheng node = node->rb_right; 14165d4f98a2SYan Zheng else 14175d4f98a2SYan Zheng break; 14185d4f98a2SYan Zheng } 14195d4f98a2SYan Zheng if (!node) { 14205d4f98a2SYan Zheng while (prev) { 14215d4f98a2SYan Zheng entry = rb_entry(prev, struct btrfs_inode, rb_node); 14225d4f98a2SYan Zheng if (objectid <= entry->vfs_inode.i_ino) { 14235d4f98a2SYan Zheng node = prev; 14245d4f98a2SYan Zheng break; 14255d4f98a2SYan Zheng } 14265d4f98a2SYan Zheng prev = rb_next(prev); 14275d4f98a2SYan Zheng } 14285d4f98a2SYan Zheng } 14295d4f98a2SYan Zheng while (node) { 14305d4f98a2SYan Zheng entry = rb_entry(node, struct btrfs_inode, rb_node); 14315d4f98a2SYan Zheng inode = igrab(&entry->vfs_inode); 14325d4f98a2SYan Zheng if (inode) { 14335d4f98a2SYan Zheng spin_unlock(&root->inode_lock); 14345d4f98a2SYan Zheng return inode; 14355d4f98a2SYan Zheng } 14365d4f98a2SYan Zheng 14375d4f98a2SYan Zheng objectid = entry->vfs_inode.i_ino + 1; 14385d4f98a2SYan Zheng if (cond_resched_lock(&root->inode_lock)) 14395d4f98a2SYan Zheng goto again; 14405d4f98a2SYan Zheng 14415d4f98a2SYan Zheng node = rb_next(node); 14425d4f98a2SYan Zheng } 14435d4f98a2SYan Zheng spin_unlock(&root->inode_lock); 14445d4f98a2SYan Zheng return NULL; 14455d4f98a2SYan Zheng } 14465d4f98a2SYan Zheng 14475d4f98a2SYan Zheng static int in_block_group(u64 bytenr, 14485d4f98a2SYan Zheng struct btrfs_block_group_cache *block_group) 14495d4f98a2SYan Zheng { 14505d4f98a2SYan Zheng if (bytenr >= block_group->key.objectid && 14515d4f98a2SYan Zheng bytenr < block_group->key.objectid + block_group->key.offset) 14525d4f98a2SYan Zheng return 1; 14535d4f98a2SYan Zheng return 0; 14545d4f98a2SYan Zheng } 14555d4f98a2SYan Zheng 14565d4f98a2SYan Zheng /* 14575d4f98a2SYan Zheng * get new location of data 14585d4f98a2SYan Zheng */ 14595d4f98a2SYan Zheng static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr, 14605d4f98a2SYan Zheng u64 bytenr, u64 num_bytes) 14615d4f98a2SYan Zheng { 14625d4f98a2SYan Zheng struct btrfs_root *root = BTRFS_I(reloc_inode)->root; 14635d4f98a2SYan Zheng struct btrfs_path *path; 14645d4f98a2SYan Zheng struct btrfs_file_extent_item *fi; 14655d4f98a2SYan Zheng struct extent_buffer *leaf; 14665d4f98a2SYan Zheng int ret; 14675d4f98a2SYan Zheng 14685d4f98a2SYan Zheng path = btrfs_alloc_path(); 14695d4f98a2SYan Zheng if (!path) 14705d4f98a2SYan Zheng return -ENOMEM; 14715d4f98a2SYan Zheng 14725d4f98a2SYan Zheng bytenr -= BTRFS_I(reloc_inode)->index_cnt; 14735d4f98a2SYan Zheng ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino, 14745d4f98a2SYan Zheng bytenr, 0); 14755d4f98a2SYan Zheng if (ret < 0) 14765d4f98a2SYan Zheng goto out; 14775d4f98a2SYan Zheng if (ret > 0) { 14785d4f98a2SYan Zheng ret = -ENOENT; 14795d4f98a2SYan Zheng goto out; 14805d4f98a2SYan Zheng } 14815d4f98a2SYan Zheng 14825d4f98a2SYan Zheng leaf = path->nodes[0]; 14835d4f98a2SYan Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 14845d4f98a2SYan Zheng struct btrfs_file_extent_item); 14855d4f98a2SYan Zheng 14865d4f98a2SYan Zheng BUG_ON(btrfs_file_extent_offset(leaf, fi) || 14875d4f98a2SYan Zheng btrfs_file_extent_compression(leaf, fi) || 14885d4f98a2SYan Zheng btrfs_file_extent_encryption(leaf, fi) || 14895d4f98a2SYan Zheng btrfs_file_extent_other_encoding(leaf, fi)); 14905d4f98a2SYan Zheng 14915d4f98a2SYan Zheng if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) { 14925d4f98a2SYan Zheng ret = 1; 14935d4f98a2SYan Zheng goto out; 14945d4f98a2SYan Zheng } 14955d4f98a2SYan Zheng 14965d4f98a2SYan Zheng *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 14975d4f98a2SYan Zheng ret = 0; 14985d4f98a2SYan Zheng out: 14995d4f98a2SYan Zheng btrfs_free_path(path); 15005d4f98a2SYan Zheng return ret; 15015d4f98a2SYan Zheng } 15025d4f98a2SYan Zheng 15035d4f98a2SYan Zheng /* 15045d4f98a2SYan Zheng * update file extent items in the tree leaf to point to 15055d4f98a2SYan Zheng * the new locations. 15065d4f98a2SYan Zheng */ 15073fd0a558SYan, Zheng static noinline_for_stack 15083fd0a558SYan, Zheng int replace_file_extents(struct btrfs_trans_handle *trans, 15095d4f98a2SYan Zheng struct reloc_control *rc, 15105d4f98a2SYan Zheng struct btrfs_root *root, 15113fd0a558SYan, Zheng struct extent_buffer *leaf) 15125d4f98a2SYan Zheng { 15135d4f98a2SYan Zheng struct btrfs_key key; 15145d4f98a2SYan Zheng struct btrfs_file_extent_item *fi; 15155d4f98a2SYan Zheng struct inode *inode = NULL; 15165d4f98a2SYan Zheng u64 parent; 15175d4f98a2SYan Zheng u64 bytenr; 15183fd0a558SYan, Zheng u64 new_bytenr = 0; 15195d4f98a2SYan Zheng u64 num_bytes; 15205d4f98a2SYan Zheng u64 end; 15215d4f98a2SYan Zheng u32 nritems; 15225d4f98a2SYan Zheng u32 i; 15235d4f98a2SYan Zheng int ret; 15245d4f98a2SYan Zheng int first = 1; 15255d4f98a2SYan Zheng int dirty = 0; 15265d4f98a2SYan Zheng 15275d4f98a2SYan Zheng if (rc->stage != UPDATE_DATA_PTRS) 15285d4f98a2SYan Zheng return 0; 15295d4f98a2SYan Zheng 15305d4f98a2SYan Zheng /* reloc trees always use full backref */ 15315d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) 15325d4f98a2SYan Zheng parent = leaf->start; 15335d4f98a2SYan Zheng else 15345d4f98a2SYan Zheng parent = 0; 15355d4f98a2SYan Zheng 15365d4f98a2SYan Zheng nritems = btrfs_header_nritems(leaf); 15375d4f98a2SYan Zheng for (i = 0; i < nritems; i++) { 15385d4f98a2SYan Zheng cond_resched(); 15395d4f98a2SYan Zheng btrfs_item_key_to_cpu(leaf, &key, i); 15405d4f98a2SYan Zheng if (key.type != BTRFS_EXTENT_DATA_KEY) 15415d4f98a2SYan Zheng continue; 15425d4f98a2SYan Zheng fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); 15435d4f98a2SYan Zheng if (btrfs_file_extent_type(leaf, fi) == 15445d4f98a2SYan Zheng BTRFS_FILE_EXTENT_INLINE) 15455d4f98a2SYan Zheng continue; 15465d4f98a2SYan Zheng bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); 15475d4f98a2SYan Zheng num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); 15485d4f98a2SYan Zheng if (bytenr == 0) 15495d4f98a2SYan Zheng continue; 15505d4f98a2SYan Zheng if (!in_block_group(bytenr, rc->block_group)) 15515d4f98a2SYan Zheng continue; 15525d4f98a2SYan Zheng 15535d4f98a2SYan Zheng /* 15545d4f98a2SYan Zheng * if we are modifying block in fs tree, wait for readpage 15555d4f98a2SYan Zheng * to complete and drop the extent cache 15565d4f98a2SYan Zheng */ 15575d4f98a2SYan Zheng if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { 15585d4f98a2SYan Zheng if (first) { 15595d4f98a2SYan Zheng inode = find_next_inode(root, key.objectid); 15605d4f98a2SYan Zheng first = 0; 15615d4f98a2SYan Zheng } else if (inode && inode->i_ino < key.objectid) { 15623fd0a558SYan, Zheng btrfs_add_delayed_iput(inode); 15635d4f98a2SYan Zheng inode = find_next_inode(root, key.objectid); 15645d4f98a2SYan Zheng } 15655d4f98a2SYan Zheng if (inode && inode->i_ino == key.objectid) { 15665d4f98a2SYan Zheng end = key.offset + 15675d4f98a2SYan Zheng btrfs_file_extent_num_bytes(leaf, fi); 15685d4f98a2SYan Zheng WARN_ON(!IS_ALIGNED(key.offset, 15695d4f98a2SYan Zheng root->sectorsize)); 15705d4f98a2SYan Zheng WARN_ON(!IS_ALIGNED(end, root->sectorsize)); 15715d4f98a2SYan Zheng end--; 15725d4f98a2SYan Zheng ret = try_lock_extent(&BTRFS_I(inode)->io_tree, 15735d4f98a2SYan Zheng key.offset, end, 15745d4f98a2SYan Zheng GFP_NOFS); 15755d4f98a2SYan Zheng if (!ret) 15765d4f98a2SYan Zheng continue; 15775d4f98a2SYan Zheng 15785d4f98a2SYan Zheng btrfs_drop_extent_cache(inode, key.offset, end, 15795d4f98a2SYan Zheng 1); 15805d4f98a2SYan Zheng unlock_extent(&BTRFS_I(inode)->io_tree, 15815d4f98a2SYan Zheng key.offset, end, GFP_NOFS); 15825d4f98a2SYan Zheng } 15835d4f98a2SYan Zheng } 15845d4f98a2SYan Zheng 15855d4f98a2SYan Zheng ret = get_new_location(rc->data_inode, &new_bytenr, 15865d4f98a2SYan Zheng bytenr, num_bytes); 15873fd0a558SYan, Zheng if (ret > 0) { 15883fd0a558SYan, Zheng WARN_ON(1); 15895d4f98a2SYan Zheng continue; 15903fd0a558SYan, Zheng } 15915d4f98a2SYan Zheng BUG_ON(ret < 0); 15925d4f98a2SYan Zheng 15935d4f98a2SYan Zheng btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr); 15945d4f98a2SYan Zheng dirty = 1; 15955d4f98a2SYan Zheng 15965d4f98a2SYan Zheng key.offset -= btrfs_file_extent_offset(leaf, fi); 15975d4f98a2SYan Zheng ret = btrfs_inc_extent_ref(trans, root, new_bytenr, 15985d4f98a2SYan Zheng num_bytes, parent, 15995d4f98a2SYan Zheng btrfs_header_owner(leaf), 16005d4f98a2SYan Zheng key.objectid, key.offset); 16015d4f98a2SYan Zheng BUG_ON(ret); 16025d4f98a2SYan Zheng 16035d4f98a2SYan Zheng ret = btrfs_free_extent(trans, root, bytenr, num_bytes, 16045d4f98a2SYan Zheng parent, btrfs_header_owner(leaf), 16055d4f98a2SYan Zheng key.objectid, key.offset); 16065d4f98a2SYan Zheng BUG_ON(ret); 16075d4f98a2SYan Zheng } 16085d4f98a2SYan Zheng if (dirty) 16095d4f98a2SYan Zheng btrfs_mark_buffer_dirty(leaf); 16103fd0a558SYan, Zheng if (inode) 16113fd0a558SYan, Zheng btrfs_add_delayed_iput(inode); 16125d4f98a2SYan Zheng return 0; 16135d4f98a2SYan Zheng } 16145d4f98a2SYan Zheng 16155d4f98a2SYan Zheng static noinline_for_stack 16165d4f98a2SYan Zheng int memcmp_node_keys(struct extent_buffer *eb, int slot, 16175d4f98a2SYan Zheng struct btrfs_path *path, int level) 16185d4f98a2SYan Zheng { 16195d4f98a2SYan Zheng struct btrfs_disk_key key1; 16205d4f98a2SYan Zheng struct btrfs_disk_key key2; 16215d4f98a2SYan Zheng btrfs_node_key(eb, &key1, slot); 16225d4f98a2SYan Zheng btrfs_node_key(path->nodes[level], &key2, path->slots[level]); 16235d4f98a2SYan Zheng return memcmp(&key1, &key2, sizeof(key1)); 16245d4f98a2SYan Zheng } 16255d4f98a2SYan Zheng 16265d4f98a2SYan Zheng /* 16275d4f98a2SYan Zheng * try to replace tree blocks in fs tree with the new blocks 16285d4f98a2SYan Zheng * in reloc tree. tree blocks haven't been modified since the 16295d4f98a2SYan Zheng * reloc tree was create can be replaced. 16305d4f98a2SYan Zheng * 16315d4f98a2SYan Zheng * if a block was replaced, level of the block + 1 is returned. 16325d4f98a2SYan Zheng * if no block got replaced, 0 is returned. if there are other 16335d4f98a2SYan Zheng * errors, a negative error number is returned. 16345d4f98a2SYan Zheng */ 16353fd0a558SYan, Zheng static noinline_for_stack 16363fd0a558SYan, Zheng int replace_path(struct btrfs_trans_handle *trans, 16375d4f98a2SYan Zheng struct btrfs_root *dest, struct btrfs_root *src, 16385d4f98a2SYan Zheng struct btrfs_path *path, struct btrfs_key *next_key, 16395d4f98a2SYan Zheng int lowest_level, int max_level) 16405d4f98a2SYan Zheng { 16415d4f98a2SYan Zheng struct extent_buffer *eb; 16425d4f98a2SYan Zheng struct extent_buffer *parent; 16435d4f98a2SYan Zheng struct btrfs_key key; 16445d4f98a2SYan Zheng u64 old_bytenr; 16455d4f98a2SYan Zheng u64 new_bytenr; 16465d4f98a2SYan Zheng u64 old_ptr_gen; 16475d4f98a2SYan Zheng u64 new_ptr_gen; 16485d4f98a2SYan Zheng u64 last_snapshot; 16495d4f98a2SYan Zheng u32 blocksize; 16503fd0a558SYan, Zheng int cow = 0; 16515d4f98a2SYan Zheng int level; 16525d4f98a2SYan Zheng int ret; 16535d4f98a2SYan Zheng int slot; 16545d4f98a2SYan Zheng 16555d4f98a2SYan Zheng BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); 16565d4f98a2SYan Zheng BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID); 16575d4f98a2SYan Zheng 16585d4f98a2SYan Zheng last_snapshot = btrfs_root_last_snapshot(&src->root_item); 16593fd0a558SYan, Zheng again: 16605d4f98a2SYan Zheng slot = path->slots[lowest_level]; 16615d4f98a2SYan Zheng btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot); 16625d4f98a2SYan Zheng 16635d4f98a2SYan Zheng eb = btrfs_lock_root_node(dest); 16645d4f98a2SYan Zheng btrfs_set_lock_blocking(eb); 16655d4f98a2SYan Zheng level = btrfs_header_level(eb); 16665d4f98a2SYan Zheng 16675d4f98a2SYan Zheng if (level < lowest_level) { 16685d4f98a2SYan Zheng btrfs_tree_unlock(eb); 16695d4f98a2SYan Zheng free_extent_buffer(eb); 16705d4f98a2SYan Zheng return 0; 16715d4f98a2SYan Zheng } 16725d4f98a2SYan Zheng 16733fd0a558SYan, Zheng if (cow) { 16745d4f98a2SYan Zheng ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb); 16755d4f98a2SYan Zheng BUG_ON(ret); 16763fd0a558SYan, Zheng } 16775d4f98a2SYan Zheng btrfs_set_lock_blocking(eb); 16785d4f98a2SYan Zheng 16795d4f98a2SYan Zheng if (next_key) { 16805d4f98a2SYan Zheng next_key->objectid = (u64)-1; 16815d4f98a2SYan Zheng next_key->type = (u8)-1; 16825d4f98a2SYan Zheng next_key->offset = (u64)-1; 16835d4f98a2SYan Zheng } 16845d4f98a2SYan Zheng 16855d4f98a2SYan Zheng parent = eb; 16865d4f98a2SYan Zheng while (1) { 16875d4f98a2SYan Zheng level = btrfs_header_level(parent); 16885d4f98a2SYan Zheng BUG_ON(level < lowest_level); 16895d4f98a2SYan Zheng 16905d4f98a2SYan Zheng ret = btrfs_bin_search(parent, &key, level, &slot); 16915d4f98a2SYan Zheng if (ret && slot > 0) 16925d4f98a2SYan Zheng slot--; 16935d4f98a2SYan Zheng 16945d4f98a2SYan Zheng if (next_key && slot + 1 < btrfs_header_nritems(parent)) 16955d4f98a2SYan Zheng btrfs_node_key_to_cpu(parent, next_key, slot + 1); 16965d4f98a2SYan Zheng 16975d4f98a2SYan Zheng old_bytenr = btrfs_node_blockptr(parent, slot); 16985d4f98a2SYan Zheng blocksize = btrfs_level_size(dest, level - 1); 16995d4f98a2SYan Zheng old_ptr_gen = btrfs_node_ptr_generation(parent, slot); 17005d4f98a2SYan Zheng 17015d4f98a2SYan Zheng if (level <= max_level) { 17025d4f98a2SYan Zheng eb = path->nodes[level]; 17035d4f98a2SYan Zheng new_bytenr = btrfs_node_blockptr(eb, 17045d4f98a2SYan Zheng path->slots[level]); 17055d4f98a2SYan Zheng new_ptr_gen = btrfs_node_ptr_generation(eb, 17065d4f98a2SYan Zheng path->slots[level]); 17075d4f98a2SYan Zheng } else { 17085d4f98a2SYan Zheng new_bytenr = 0; 17095d4f98a2SYan Zheng new_ptr_gen = 0; 17105d4f98a2SYan Zheng } 17115d4f98a2SYan Zheng 17125d4f98a2SYan Zheng if (new_bytenr > 0 && new_bytenr == old_bytenr) { 17135d4f98a2SYan Zheng WARN_ON(1); 17145d4f98a2SYan Zheng ret = level; 17155d4f98a2SYan Zheng break; 17165d4f98a2SYan Zheng } 17175d4f98a2SYan Zheng 17185d4f98a2SYan Zheng if (new_bytenr == 0 || old_ptr_gen > last_snapshot || 17195d4f98a2SYan Zheng memcmp_node_keys(parent, slot, path, level)) { 17203fd0a558SYan, Zheng if (level <= lowest_level) { 17215d4f98a2SYan Zheng ret = 0; 17225d4f98a2SYan Zheng break; 17235d4f98a2SYan Zheng } 17245d4f98a2SYan Zheng 17255d4f98a2SYan Zheng eb = read_tree_block(dest, old_bytenr, blocksize, 17265d4f98a2SYan Zheng old_ptr_gen); 17275d4f98a2SYan Zheng btrfs_tree_lock(eb); 17283fd0a558SYan, Zheng if (cow) { 17295d4f98a2SYan Zheng ret = btrfs_cow_block(trans, dest, eb, parent, 17305d4f98a2SYan Zheng slot, &eb); 17315d4f98a2SYan Zheng BUG_ON(ret); 17325d4f98a2SYan Zheng } 17333fd0a558SYan, Zheng btrfs_set_lock_blocking(eb); 17345d4f98a2SYan Zheng 17355d4f98a2SYan Zheng btrfs_tree_unlock(parent); 17365d4f98a2SYan Zheng free_extent_buffer(parent); 17375d4f98a2SYan Zheng 17385d4f98a2SYan Zheng parent = eb; 17395d4f98a2SYan Zheng continue; 17405d4f98a2SYan Zheng } 17415d4f98a2SYan Zheng 17423fd0a558SYan, Zheng if (!cow) { 17433fd0a558SYan, Zheng btrfs_tree_unlock(parent); 17443fd0a558SYan, Zheng free_extent_buffer(parent); 17453fd0a558SYan, Zheng cow = 1; 17463fd0a558SYan, Zheng goto again; 17473fd0a558SYan, Zheng } 17483fd0a558SYan, Zheng 17495d4f98a2SYan Zheng btrfs_node_key_to_cpu(path->nodes[level], &key, 17505d4f98a2SYan Zheng path->slots[level]); 17515d4f98a2SYan Zheng btrfs_release_path(src, path); 17525d4f98a2SYan Zheng 17535d4f98a2SYan Zheng path->lowest_level = level; 17545d4f98a2SYan Zheng ret = btrfs_search_slot(trans, src, &key, path, 0, 1); 17555d4f98a2SYan Zheng path->lowest_level = 0; 17565d4f98a2SYan Zheng BUG_ON(ret); 17575d4f98a2SYan Zheng 17585d4f98a2SYan Zheng /* 17595d4f98a2SYan Zheng * swap blocks in fs tree and reloc tree. 17605d4f98a2SYan Zheng */ 17615d4f98a2SYan Zheng btrfs_set_node_blockptr(parent, slot, new_bytenr); 17625d4f98a2SYan Zheng btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen); 17635d4f98a2SYan Zheng btrfs_mark_buffer_dirty(parent); 17645d4f98a2SYan Zheng 17655d4f98a2SYan Zheng btrfs_set_node_blockptr(path->nodes[level], 17665d4f98a2SYan Zheng path->slots[level], old_bytenr); 17675d4f98a2SYan Zheng btrfs_set_node_ptr_generation(path->nodes[level], 17685d4f98a2SYan Zheng path->slots[level], old_ptr_gen); 17695d4f98a2SYan Zheng btrfs_mark_buffer_dirty(path->nodes[level]); 17705d4f98a2SYan Zheng 17715d4f98a2SYan Zheng ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize, 17725d4f98a2SYan Zheng path->nodes[level]->start, 17735d4f98a2SYan Zheng src->root_key.objectid, level - 1, 0); 17745d4f98a2SYan Zheng BUG_ON(ret); 17755d4f98a2SYan Zheng ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize, 17765d4f98a2SYan Zheng 0, dest->root_key.objectid, level - 1, 17775d4f98a2SYan Zheng 0); 17785d4f98a2SYan Zheng BUG_ON(ret); 17795d4f98a2SYan Zheng 17805d4f98a2SYan Zheng ret = btrfs_free_extent(trans, src, new_bytenr, blocksize, 17815d4f98a2SYan Zheng path->nodes[level]->start, 17825d4f98a2SYan Zheng src->root_key.objectid, level - 1, 0); 17835d4f98a2SYan Zheng BUG_ON(ret); 17845d4f98a2SYan Zheng 17855d4f98a2SYan Zheng ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize, 17865d4f98a2SYan Zheng 0, dest->root_key.objectid, level - 1, 17875d4f98a2SYan Zheng 0); 17885d4f98a2SYan Zheng BUG_ON(ret); 17895d4f98a2SYan Zheng 17905d4f98a2SYan Zheng btrfs_unlock_up_safe(path, 0); 17915d4f98a2SYan Zheng 17925d4f98a2SYan Zheng ret = level; 17935d4f98a2SYan Zheng break; 17945d4f98a2SYan Zheng } 17955d4f98a2SYan Zheng btrfs_tree_unlock(parent); 17965d4f98a2SYan Zheng free_extent_buffer(parent); 17975d4f98a2SYan Zheng return ret; 17985d4f98a2SYan Zheng } 17995d4f98a2SYan Zheng 18005d4f98a2SYan Zheng /* 18015d4f98a2SYan Zheng * helper to find next relocated block in reloc tree 18025d4f98a2SYan Zheng */ 18035d4f98a2SYan Zheng static noinline_for_stack 18045d4f98a2SYan Zheng int walk_up_reloc_tree(struct btrfs_root *root, struct btrfs_path *path, 18055d4f98a2SYan Zheng int *level) 18065d4f98a2SYan Zheng { 18075d4f98a2SYan Zheng struct extent_buffer *eb; 18085d4f98a2SYan Zheng int i; 18095d4f98a2SYan Zheng u64 last_snapshot; 18105d4f98a2SYan Zheng u32 nritems; 18115d4f98a2SYan Zheng 18125d4f98a2SYan Zheng last_snapshot = btrfs_root_last_snapshot(&root->root_item); 18135d4f98a2SYan Zheng 18145d4f98a2SYan Zheng for (i = 0; i < *level; i++) { 18155d4f98a2SYan Zheng free_extent_buffer(path->nodes[i]); 18165d4f98a2SYan Zheng path->nodes[i] = NULL; 18175d4f98a2SYan Zheng } 18185d4f98a2SYan Zheng 18195d4f98a2SYan Zheng for (i = *level; i < BTRFS_MAX_LEVEL && path->nodes[i]; i++) { 18205d4f98a2SYan Zheng eb = path->nodes[i]; 18215d4f98a2SYan Zheng nritems = btrfs_header_nritems(eb); 18225d4f98a2SYan Zheng while (path->slots[i] + 1 < nritems) { 18235d4f98a2SYan Zheng path->slots[i]++; 18245d4f98a2SYan Zheng if (btrfs_node_ptr_generation(eb, path->slots[i]) <= 18255d4f98a2SYan Zheng last_snapshot) 18265d4f98a2SYan Zheng continue; 18275d4f98a2SYan Zheng 18285d4f98a2SYan Zheng *level = i; 18295d4f98a2SYan Zheng return 0; 18305d4f98a2SYan Zheng } 18315d4f98a2SYan Zheng free_extent_buffer(path->nodes[i]); 18325d4f98a2SYan Zheng path->nodes[i] = NULL; 18335d4f98a2SYan Zheng } 18345d4f98a2SYan Zheng return 1; 18355d4f98a2SYan Zheng } 18365d4f98a2SYan Zheng 18375d4f98a2SYan Zheng /* 18385d4f98a2SYan Zheng * walk down reloc tree to find relocated block of lowest level 18395d4f98a2SYan Zheng */ 18405d4f98a2SYan Zheng static noinline_for_stack 18415d4f98a2SYan Zheng int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path, 18425d4f98a2SYan Zheng int *level) 18435d4f98a2SYan Zheng { 18445d4f98a2SYan Zheng struct extent_buffer *eb = NULL; 18455d4f98a2SYan Zheng int i; 18465d4f98a2SYan Zheng u64 bytenr; 18475d4f98a2SYan Zheng u64 ptr_gen = 0; 18485d4f98a2SYan Zheng u64 last_snapshot; 18495d4f98a2SYan Zheng u32 blocksize; 18505d4f98a2SYan Zheng u32 nritems; 18515d4f98a2SYan Zheng 18525d4f98a2SYan Zheng last_snapshot = btrfs_root_last_snapshot(&root->root_item); 18535d4f98a2SYan Zheng 18545d4f98a2SYan Zheng for (i = *level; i > 0; i--) { 18555d4f98a2SYan Zheng eb = path->nodes[i]; 18565d4f98a2SYan Zheng nritems = btrfs_header_nritems(eb); 18575d4f98a2SYan Zheng while (path->slots[i] < nritems) { 18585d4f98a2SYan Zheng ptr_gen = btrfs_node_ptr_generation(eb, path->slots[i]); 18595d4f98a2SYan Zheng if (ptr_gen > last_snapshot) 18605d4f98a2SYan Zheng break; 18615d4f98a2SYan Zheng path->slots[i]++; 18625d4f98a2SYan Zheng } 18635d4f98a2SYan Zheng if (path->slots[i] >= nritems) { 18645d4f98a2SYan Zheng if (i == *level) 18655d4f98a2SYan Zheng break; 18665d4f98a2SYan Zheng *level = i + 1; 18675d4f98a2SYan Zheng return 0; 18685d4f98a2SYan Zheng } 18695d4f98a2SYan Zheng if (i == 1) { 18705d4f98a2SYan Zheng *level = i; 18715d4f98a2SYan Zheng return 0; 18725d4f98a2SYan Zheng } 18735d4f98a2SYan Zheng 18745d4f98a2SYan Zheng bytenr = btrfs_node_blockptr(eb, path->slots[i]); 18755d4f98a2SYan Zheng blocksize = btrfs_level_size(root, i - 1); 18765d4f98a2SYan Zheng eb = read_tree_block(root, bytenr, blocksize, ptr_gen); 18775d4f98a2SYan Zheng BUG_ON(btrfs_header_level(eb) != i - 1); 18785d4f98a2SYan Zheng path->nodes[i - 1] = eb; 18795d4f98a2SYan Zheng path->slots[i - 1] = 0; 18805d4f98a2SYan Zheng } 18815d4f98a2SYan Zheng return 1; 18825d4f98a2SYan Zheng } 18835d4f98a2SYan Zheng 18845d4f98a2SYan Zheng /* 18855d4f98a2SYan Zheng * invalidate extent cache for file extents whose key in range of 18865d4f98a2SYan Zheng * [min_key, max_key) 18875d4f98a2SYan Zheng */ 18885d4f98a2SYan Zheng static int invalidate_extent_cache(struct btrfs_root *root, 18895d4f98a2SYan Zheng struct btrfs_key *min_key, 18905d4f98a2SYan Zheng struct btrfs_key *max_key) 18915d4f98a2SYan Zheng { 18925d4f98a2SYan Zheng struct inode *inode = NULL; 18935d4f98a2SYan Zheng u64 objectid; 18945d4f98a2SYan Zheng u64 start, end; 18955d4f98a2SYan Zheng 18965d4f98a2SYan Zheng objectid = min_key->objectid; 18975d4f98a2SYan Zheng while (1) { 18985d4f98a2SYan Zheng cond_resched(); 18995d4f98a2SYan Zheng iput(inode); 19005d4f98a2SYan Zheng 19015d4f98a2SYan Zheng if (objectid > max_key->objectid) 19025d4f98a2SYan Zheng break; 19035d4f98a2SYan Zheng 19045d4f98a2SYan Zheng inode = find_next_inode(root, objectid); 19055d4f98a2SYan Zheng if (!inode) 19065d4f98a2SYan Zheng break; 19075d4f98a2SYan Zheng 19085d4f98a2SYan Zheng if (inode->i_ino > max_key->objectid) { 19095d4f98a2SYan Zheng iput(inode); 19105d4f98a2SYan Zheng break; 19115d4f98a2SYan Zheng } 19125d4f98a2SYan Zheng 19135d4f98a2SYan Zheng objectid = inode->i_ino + 1; 19145d4f98a2SYan Zheng if (!S_ISREG(inode->i_mode)) 19155d4f98a2SYan Zheng continue; 19165d4f98a2SYan Zheng 19175d4f98a2SYan Zheng if (unlikely(min_key->objectid == inode->i_ino)) { 19185d4f98a2SYan Zheng if (min_key->type > BTRFS_EXTENT_DATA_KEY) 19195d4f98a2SYan Zheng continue; 19205d4f98a2SYan Zheng if (min_key->type < BTRFS_EXTENT_DATA_KEY) 19215d4f98a2SYan Zheng start = 0; 19225d4f98a2SYan Zheng else { 19235d4f98a2SYan Zheng start = min_key->offset; 19245d4f98a2SYan Zheng WARN_ON(!IS_ALIGNED(start, root->sectorsize)); 19255d4f98a2SYan Zheng } 19265d4f98a2SYan Zheng } else { 19275d4f98a2SYan Zheng start = 0; 19285d4f98a2SYan Zheng } 19295d4f98a2SYan Zheng 19305d4f98a2SYan Zheng if (unlikely(max_key->objectid == inode->i_ino)) { 19315d4f98a2SYan Zheng if (max_key->type < BTRFS_EXTENT_DATA_KEY) 19325d4f98a2SYan Zheng continue; 19335d4f98a2SYan Zheng if (max_key->type > BTRFS_EXTENT_DATA_KEY) { 19345d4f98a2SYan Zheng end = (u64)-1; 19355d4f98a2SYan Zheng } else { 19365d4f98a2SYan Zheng if (max_key->offset == 0) 19375d4f98a2SYan Zheng continue; 19385d4f98a2SYan Zheng end = max_key->offset; 19395d4f98a2SYan Zheng WARN_ON(!IS_ALIGNED(end, root->sectorsize)); 19405d4f98a2SYan Zheng end--; 19415d4f98a2SYan Zheng } 19425d4f98a2SYan Zheng } else { 19435d4f98a2SYan Zheng end = (u64)-1; 19445d4f98a2SYan Zheng } 19455d4f98a2SYan Zheng 19465d4f98a2SYan Zheng /* the lock_extent waits for readpage to complete */ 19475d4f98a2SYan Zheng lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); 19485d4f98a2SYan Zheng btrfs_drop_extent_cache(inode, start, end, 1); 19495d4f98a2SYan Zheng unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); 19505d4f98a2SYan Zheng } 19515d4f98a2SYan Zheng return 0; 19525d4f98a2SYan Zheng } 19535d4f98a2SYan Zheng 19545d4f98a2SYan Zheng static int find_next_key(struct btrfs_path *path, int level, 19555d4f98a2SYan Zheng struct btrfs_key *key) 19565d4f98a2SYan Zheng 19575d4f98a2SYan Zheng { 19585d4f98a2SYan Zheng while (level < BTRFS_MAX_LEVEL) { 19595d4f98a2SYan Zheng if (!path->nodes[level]) 19605d4f98a2SYan Zheng break; 19615d4f98a2SYan Zheng if (path->slots[level] + 1 < 19625d4f98a2SYan Zheng btrfs_header_nritems(path->nodes[level])) { 19635d4f98a2SYan Zheng btrfs_node_key_to_cpu(path->nodes[level], key, 19645d4f98a2SYan Zheng path->slots[level] + 1); 19655d4f98a2SYan Zheng return 0; 19665d4f98a2SYan Zheng } 19675d4f98a2SYan Zheng level++; 19685d4f98a2SYan Zheng } 19695d4f98a2SYan Zheng return 1; 19705d4f98a2SYan Zheng } 19715d4f98a2SYan Zheng 19725d4f98a2SYan Zheng /* 19735d4f98a2SYan Zheng * merge the relocated tree blocks in reloc tree with corresponding 19745d4f98a2SYan Zheng * fs tree. 19755d4f98a2SYan Zheng */ 19765d4f98a2SYan Zheng static noinline_for_stack int merge_reloc_root(struct reloc_control *rc, 19775d4f98a2SYan Zheng struct btrfs_root *root) 19785d4f98a2SYan Zheng { 19795d4f98a2SYan Zheng LIST_HEAD(inode_list); 19805d4f98a2SYan Zheng struct btrfs_key key; 19815d4f98a2SYan Zheng struct btrfs_key next_key; 19825d4f98a2SYan Zheng struct btrfs_trans_handle *trans; 19835d4f98a2SYan Zheng struct btrfs_root *reloc_root; 19845d4f98a2SYan Zheng struct btrfs_root_item *root_item; 19855d4f98a2SYan Zheng struct btrfs_path *path; 19863fd0a558SYan, Zheng struct extent_buffer *leaf; 19875d4f98a2SYan Zheng unsigned long nr; 19885d4f98a2SYan Zheng int level; 19895d4f98a2SYan Zheng int max_level; 19905d4f98a2SYan Zheng int replaced = 0; 19915d4f98a2SYan Zheng int ret; 19925d4f98a2SYan Zheng int err = 0; 19933fd0a558SYan, Zheng u32 min_reserved; 19945d4f98a2SYan Zheng 19955d4f98a2SYan Zheng path = btrfs_alloc_path(); 19965d4f98a2SYan Zheng if (!path) 19975d4f98a2SYan Zheng return -ENOMEM; 19985d4f98a2SYan Zheng 19995d4f98a2SYan Zheng reloc_root = root->reloc_root; 20005d4f98a2SYan Zheng root_item = &reloc_root->root_item; 20015d4f98a2SYan Zheng 20025d4f98a2SYan Zheng if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { 20035d4f98a2SYan Zheng level = btrfs_root_level(root_item); 20045d4f98a2SYan Zheng extent_buffer_get(reloc_root->node); 20055d4f98a2SYan Zheng path->nodes[level] = reloc_root->node; 20065d4f98a2SYan Zheng path->slots[level] = 0; 20075d4f98a2SYan Zheng } else { 20085d4f98a2SYan Zheng btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); 20095d4f98a2SYan Zheng 20105d4f98a2SYan Zheng level = root_item->drop_level; 20115d4f98a2SYan Zheng BUG_ON(level == 0); 20125d4f98a2SYan Zheng path->lowest_level = level; 20135d4f98a2SYan Zheng ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0); 201433c66f43SYan Zheng path->lowest_level = 0; 20155d4f98a2SYan Zheng if (ret < 0) { 20165d4f98a2SYan Zheng btrfs_free_path(path); 20175d4f98a2SYan Zheng return ret; 20185d4f98a2SYan Zheng } 20195d4f98a2SYan Zheng 20205d4f98a2SYan Zheng btrfs_node_key_to_cpu(path->nodes[level], &next_key, 20215d4f98a2SYan Zheng path->slots[level]); 20225d4f98a2SYan Zheng WARN_ON(memcmp(&key, &next_key, sizeof(key))); 20235d4f98a2SYan Zheng 20245d4f98a2SYan Zheng btrfs_unlock_up_safe(path, 0); 20255d4f98a2SYan Zheng } 20265d4f98a2SYan Zheng 20273fd0a558SYan, Zheng min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2; 20285d4f98a2SYan Zheng memset(&next_key, 0, sizeof(next_key)); 20295d4f98a2SYan Zheng 20305d4f98a2SYan Zheng while (1) { 2031a22285a6SYan, Zheng trans = btrfs_start_transaction(root, 0); 20323fd0a558SYan, Zheng trans->block_rsv = rc->block_rsv; 20333fd0a558SYan, Zheng 20343fd0a558SYan, Zheng ret = btrfs_block_rsv_check(trans, root, rc->block_rsv, 20353fd0a558SYan, Zheng min_reserved, 0); 20363fd0a558SYan, Zheng if (ret) { 20373fd0a558SYan, Zheng BUG_ON(ret != -EAGAIN); 20383fd0a558SYan, Zheng ret = btrfs_commit_transaction(trans, root); 20393fd0a558SYan, Zheng BUG_ON(ret); 20403fd0a558SYan, Zheng continue; 20413fd0a558SYan, Zheng } 20423fd0a558SYan, Zheng 20433fd0a558SYan, Zheng replaced = 0; 20445d4f98a2SYan Zheng max_level = level; 20455d4f98a2SYan Zheng 20465d4f98a2SYan Zheng ret = walk_down_reloc_tree(reloc_root, path, &level); 20475d4f98a2SYan Zheng if (ret < 0) { 20485d4f98a2SYan Zheng err = ret; 20495d4f98a2SYan Zheng goto out; 20505d4f98a2SYan Zheng } 20515d4f98a2SYan Zheng if (ret > 0) 20525d4f98a2SYan Zheng break; 20535d4f98a2SYan Zheng 20545d4f98a2SYan Zheng if (!find_next_key(path, level, &key) && 20555d4f98a2SYan Zheng btrfs_comp_cpu_keys(&next_key, &key) >= 0) { 20565d4f98a2SYan Zheng ret = 0; 20575d4f98a2SYan Zheng } else { 20583fd0a558SYan, Zheng ret = replace_path(trans, root, reloc_root, path, 20593fd0a558SYan, Zheng &next_key, level, max_level); 20605d4f98a2SYan Zheng } 20615d4f98a2SYan Zheng if (ret < 0) { 20625d4f98a2SYan Zheng err = ret; 20635d4f98a2SYan Zheng goto out; 20645d4f98a2SYan Zheng } 20655d4f98a2SYan Zheng 20665d4f98a2SYan Zheng if (ret > 0) { 20675d4f98a2SYan Zheng level = ret; 20685d4f98a2SYan Zheng btrfs_node_key_to_cpu(path->nodes[level], &key, 20695d4f98a2SYan Zheng path->slots[level]); 20705d4f98a2SYan Zheng replaced = 1; 20715d4f98a2SYan Zheng } 20725d4f98a2SYan Zheng 20735d4f98a2SYan Zheng ret = walk_up_reloc_tree(reloc_root, path, &level); 20745d4f98a2SYan Zheng if (ret > 0) 20755d4f98a2SYan Zheng break; 20765d4f98a2SYan Zheng 20775d4f98a2SYan Zheng BUG_ON(level == 0); 20785d4f98a2SYan Zheng /* 20795d4f98a2SYan Zheng * save the merging progress in the drop_progress. 20805d4f98a2SYan Zheng * this is OK since root refs == 1 in this case. 20815d4f98a2SYan Zheng */ 20825d4f98a2SYan Zheng btrfs_node_key(path->nodes[level], &root_item->drop_progress, 20835d4f98a2SYan Zheng path->slots[level]); 20845d4f98a2SYan Zheng root_item->drop_level = level; 20855d4f98a2SYan Zheng 20865d4f98a2SYan Zheng nr = trans->blocks_used; 20873fd0a558SYan, Zheng btrfs_end_transaction_throttle(trans, root); 20885d4f98a2SYan Zheng 20895d4f98a2SYan Zheng btrfs_btree_balance_dirty(root, nr); 20905d4f98a2SYan Zheng 20915d4f98a2SYan Zheng if (replaced && rc->stage == UPDATE_DATA_PTRS) 20925d4f98a2SYan Zheng invalidate_extent_cache(root, &key, &next_key); 20935d4f98a2SYan Zheng } 20945d4f98a2SYan Zheng 20955d4f98a2SYan Zheng /* 20965d4f98a2SYan Zheng * handle the case only one block in the fs tree need to be 20975d4f98a2SYan Zheng * relocated and the block is tree root. 20985d4f98a2SYan Zheng */ 20995d4f98a2SYan Zheng leaf = btrfs_lock_root_node(root); 21005d4f98a2SYan Zheng ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf); 21015d4f98a2SYan Zheng btrfs_tree_unlock(leaf); 21025d4f98a2SYan Zheng free_extent_buffer(leaf); 21035d4f98a2SYan Zheng if (ret < 0) 21045d4f98a2SYan Zheng err = ret; 21055d4f98a2SYan Zheng out: 21065d4f98a2SYan Zheng btrfs_free_path(path); 21075d4f98a2SYan Zheng 21085d4f98a2SYan Zheng if (err == 0) { 21095d4f98a2SYan Zheng memset(&root_item->drop_progress, 0, 21105d4f98a2SYan Zheng sizeof(root_item->drop_progress)); 21115d4f98a2SYan Zheng root_item->drop_level = 0; 21125d4f98a2SYan Zheng btrfs_set_root_refs(root_item, 0); 21133fd0a558SYan, Zheng btrfs_update_reloc_root(trans, root); 21145d4f98a2SYan Zheng } 21155d4f98a2SYan Zheng 21165d4f98a2SYan Zheng nr = trans->blocks_used; 21173fd0a558SYan, Zheng btrfs_end_transaction_throttle(trans, root); 21185d4f98a2SYan Zheng 21195d4f98a2SYan Zheng btrfs_btree_balance_dirty(root, nr); 21205d4f98a2SYan Zheng 21215d4f98a2SYan Zheng if (replaced && rc->stage == UPDATE_DATA_PTRS) 21225d4f98a2SYan Zheng invalidate_extent_cache(root, &key, &next_key); 21235d4f98a2SYan Zheng 21245d4f98a2SYan Zheng return err; 21255d4f98a2SYan Zheng } 21265d4f98a2SYan Zheng 21273fd0a558SYan, Zheng static noinline_for_stack 21283fd0a558SYan, Zheng int prepare_to_merge(struct reloc_control *rc, int err) 21295d4f98a2SYan Zheng { 21303fd0a558SYan, Zheng struct btrfs_root *root = rc->extent_root; 21313fd0a558SYan, Zheng struct btrfs_root *reloc_root; 21325d4f98a2SYan Zheng struct btrfs_trans_handle *trans; 21333fd0a558SYan, Zheng LIST_HEAD(reloc_roots); 21343fd0a558SYan, Zheng u64 num_bytes = 0; 21353fd0a558SYan, Zheng int ret; 21363fd0a558SYan, Zheng int retries = 0; 21373fd0a558SYan, Zheng 21383fd0a558SYan, Zheng mutex_lock(&root->fs_info->trans_mutex); 21393fd0a558SYan, Zheng rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2; 21403fd0a558SYan, Zheng rc->merging_rsv_size += rc->nodes_relocated * 2; 21413fd0a558SYan, Zheng mutex_unlock(&root->fs_info->trans_mutex); 21423fd0a558SYan, Zheng again: 21433fd0a558SYan, Zheng if (!err) { 21443fd0a558SYan, Zheng num_bytes = rc->merging_rsv_size; 21453fd0a558SYan, Zheng ret = btrfs_block_rsv_add(NULL, root, rc->block_rsv, 21463fd0a558SYan, Zheng num_bytes, &retries); 21473fd0a558SYan, Zheng if (ret) 21483fd0a558SYan, Zheng err = ret; 21493fd0a558SYan, Zheng } 21503fd0a558SYan, Zheng 21513fd0a558SYan, Zheng trans = btrfs_join_transaction(rc->extent_root, 1); 21523fd0a558SYan, Zheng 21533fd0a558SYan, Zheng if (!err) { 21543fd0a558SYan, Zheng if (num_bytes != rc->merging_rsv_size) { 21553fd0a558SYan, Zheng btrfs_end_transaction(trans, rc->extent_root); 21563fd0a558SYan, Zheng btrfs_block_rsv_release(rc->extent_root, 21573fd0a558SYan, Zheng rc->block_rsv, num_bytes); 21583fd0a558SYan, Zheng retries = 0; 21593fd0a558SYan, Zheng goto again; 21603fd0a558SYan, Zheng } 21613fd0a558SYan, Zheng } 21623fd0a558SYan, Zheng 21633fd0a558SYan, Zheng rc->merge_reloc_tree = 1; 21643fd0a558SYan, Zheng 21653fd0a558SYan, Zheng while (!list_empty(&rc->reloc_roots)) { 21663fd0a558SYan, Zheng reloc_root = list_entry(rc->reloc_roots.next, 21673fd0a558SYan, Zheng struct btrfs_root, root_list); 21683fd0a558SYan, Zheng list_del_init(&reloc_root->root_list); 21693fd0a558SYan, Zheng 21703fd0a558SYan, Zheng root = read_fs_root(reloc_root->fs_info, 21713fd0a558SYan, Zheng reloc_root->root_key.offset); 21723fd0a558SYan, Zheng BUG_ON(IS_ERR(root)); 21733fd0a558SYan, Zheng BUG_ON(root->reloc_root != reloc_root); 21743fd0a558SYan, Zheng 21753fd0a558SYan, Zheng /* 21763fd0a558SYan, Zheng * set reference count to 1, so btrfs_recover_relocation 21773fd0a558SYan, Zheng * knows it should resumes merging 21783fd0a558SYan, Zheng */ 21793fd0a558SYan, Zheng if (!err) 21803fd0a558SYan, Zheng btrfs_set_root_refs(&reloc_root->root_item, 1); 21813fd0a558SYan, Zheng btrfs_update_reloc_root(trans, root); 21823fd0a558SYan, Zheng 21833fd0a558SYan, Zheng list_add(&reloc_root->root_list, &reloc_roots); 21843fd0a558SYan, Zheng } 21853fd0a558SYan, Zheng 21863fd0a558SYan, Zheng list_splice(&reloc_roots, &rc->reloc_roots); 21873fd0a558SYan, Zheng 21883fd0a558SYan, Zheng if (!err) 21893fd0a558SYan, Zheng btrfs_commit_transaction(trans, rc->extent_root); 21903fd0a558SYan, Zheng else 21913fd0a558SYan, Zheng btrfs_end_transaction(trans, rc->extent_root); 21923fd0a558SYan, Zheng return err; 21933fd0a558SYan, Zheng } 21943fd0a558SYan, Zheng 21953fd0a558SYan, Zheng static noinline_for_stack 21963fd0a558SYan, Zheng int merge_reloc_roots(struct reloc_control *rc) 21973fd0a558SYan, Zheng { 21985d4f98a2SYan Zheng struct btrfs_root *root; 21995d4f98a2SYan Zheng struct btrfs_root *reloc_root; 22003fd0a558SYan, Zheng LIST_HEAD(reloc_roots); 22013fd0a558SYan, Zheng int found = 0; 22023fd0a558SYan, Zheng int ret; 22033fd0a558SYan, Zheng again: 22043fd0a558SYan, Zheng root = rc->extent_root; 22053fd0a558SYan, Zheng mutex_lock(&root->fs_info->trans_mutex); 22063fd0a558SYan, Zheng list_splice_init(&rc->reloc_roots, &reloc_roots); 22073fd0a558SYan, Zheng mutex_unlock(&root->fs_info->trans_mutex); 22085d4f98a2SYan Zheng 22093fd0a558SYan, Zheng while (!list_empty(&reloc_roots)) { 22103fd0a558SYan, Zheng found = 1; 22113fd0a558SYan, Zheng reloc_root = list_entry(reloc_roots.next, 22123fd0a558SYan, Zheng struct btrfs_root, root_list); 22135d4f98a2SYan Zheng 22145d4f98a2SYan Zheng if (btrfs_root_refs(&reloc_root->root_item) > 0) { 22155d4f98a2SYan Zheng root = read_fs_root(reloc_root->fs_info, 22165d4f98a2SYan Zheng reloc_root->root_key.offset); 22175d4f98a2SYan Zheng BUG_ON(IS_ERR(root)); 22185d4f98a2SYan Zheng BUG_ON(root->reloc_root != reloc_root); 22195d4f98a2SYan Zheng 22203fd0a558SYan, Zheng ret = merge_reloc_root(rc, root); 22213fd0a558SYan, Zheng BUG_ON(ret); 22223fd0a558SYan, Zheng } else { 22233fd0a558SYan, Zheng list_del_init(&reloc_root->root_list); 22243fd0a558SYan, Zheng } 22253fd0a558SYan, Zheng btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0); 22265d4f98a2SYan Zheng } 22275d4f98a2SYan Zheng 22283fd0a558SYan, Zheng if (found) { 22293fd0a558SYan, Zheng found = 0; 22303fd0a558SYan, Zheng goto again; 22315d4f98a2SYan Zheng } 22325d4f98a2SYan Zheng BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root)); 22335d4f98a2SYan Zheng return 0; 22345d4f98a2SYan Zheng } 22355d4f98a2SYan Zheng 22365d4f98a2SYan Zheng static void free_block_list(struct rb_root *blocks) 22375d4f98a2SYan Zheng { 22385d4f98a2SYan Zheng struct tree_block *block; 22395d4f98a2SYan Zheng struct rb_node *rb_node; 22405d4f98a2SYan Zheng while ((rb_node = rb_first(blocks))) { 22415d4f98a2SYan Zheng block = rb_entry(rb_node, struct tree_block, rb_node); 22425d4f98a2SYan Zheng rb_erase(rb_node, blocks); 22435d4f98a2SYan Zheng kfree(block); 22445d4f98a2SYan Zheng } 22455d4f98a2SYan Zheng } 22465d4f98a2SYan Zheng 22475d4f98a2SYan Zheng static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans, 22485d4f98a2SYan Zheng struct btrfs_root *reloc_root) 22495d4f98a2SYan Zheng { 22505d4f98a2SYan Zheng struct btrfs_root *root; 22515d4f98a2SYan Zheng 22525d4f98a2SYan Zheng if (reloc_root->last_trans == trans->transid) 22535d4f98a2SYan Zheng return 0; 22545d4f98a2SYan Zheng 22555d4f98a2SYan Zheng root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset); 22565d4f98a2SYan Zheng BUG_ON(IS_ERR(root)); 22575d4f98a2SYan Zheng BUG_ON(root->reloc_root != reloc_root); 22585d4f98a2SYan Zheng 22595d4f98a2SYan Zheng return btrfs_record_root_in_trans(trans, root); 22605d4f98a2SYan Zheng } 22615d4f98a2SYan Zheng 22623fd0a558SYan, Zheng static noinline_for_stack 22633fd0a558SYan, Zheng struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans, 22643fd0a558SYan, Zheng struct reloc_control *rc, 22655d4f98a2SYan Zheng struct backref_node *node, 22663fd0a558SYan, Zheng struct backref_edge *edges[], int *nr) 22675d4f98a2SYan Zheng { 22685d4f98a2SYan Zheng struct backref_node *next; 22695d4f98a2SYan Zheng struct btrfs_root *root; 22703fd0a558SYan, Zheng int index = 0; 22713fd0a558SYan, Zheng 22725d4f98a2SYan Zheng next = node; 22735d4f98a2SYan Zheng while (1) { 22745d4f98a2SYan Zheng cond_resched(); 22755d4f98a2SYan Zheng next = walk_up_backref(next, edges, &index); 22765d4f98a2SYan Zheng root = next->root; 22773fd0a558SYan, Zheng BUG_ON(!root); 22783fd0a558SYan, Zheng BUG_ON(!root->ref_cows); 22795d4f98a2SYan Zheng 22805d4f98a2SYan Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { 22815d4f98a2SYan Zheng record_reloc_root_in_trans(trans, root); 22825d4f98a2SYan Zheng break; 22835d4f98a2SYan Zheng } 22845d4f98a2SYan Zheng 22855d4f98a2SYan Zheng btrfs_record_root_in_trans(trans, root); 22863fd0a558SYan, Zheng root = root->reloc_root; 22873fd0a558SYan, Zheng 22883fd0a558SYan, Zheng if (next->new_bytenr != root->node->start) { 22893fd0a558SYan, Zheng BUG_ON(next->new_bytenr); 22903fd0a558SYan, Zheng BUG_ON(!list_empty(&next->list)); 22913fd0a558SYan, Zheng next->new_bytenr = root->node->start; 22923fd0a558SYan, Zheng next->root = root; 22933fd0a558SYan, Zheng list_add_tail(&next->list, 22943fd0a558SYan, Zheng &rc->backref_cache.changed); 22953fd0a558SYan, Zheng __mark_block_processed(rc, next); 22965d4f98a2SYan Zheng break; 22975d4f98a2SYan Zheng } 22985d4f98a2SYan Zheng 22993fd0a558SYan, Zheng WARN_ON(1); 23005d4f98a2SYan Zheng root = NULL; 23015d4f98a2SYan Zheng next = walk_down_backref(edges, &index); 23025d4f98a2SYan Zheng if (!next || next->level <= node->level) 23035d4f98a2SYan Zheng break; 23045d4f98a2SYan Zheng } 23053fd0a558SYan, Zheng if (!root) 23063fd0a558SYan, Zheng return NULL; 23075d4f98a2SYan Zheng 23085d4f98a2SYan Zheng *nr = index; 23093fd0a558SYan, Zheng next = node; 23103fd0a558SYan, Zheng /* setup backref node path for btrfs_reloc_cow_block */ 23113fd0a558SYan, Zheng while (1) { 23123fd0a558SYan, Zheng rc->backref_cache.path[next->level] = next; 23133fd0a558SYan, Zheng if (--index < 0) 23143fd0a558SYan, Zheng break; 23153fd0a558SYan, Zheng next = edges[index]->node[UPPER]; 23163fd0a558SYan, Zheng } 23175d4f98a2SYan Zheng return root; 23185d4f98a2SYan Zheng } 23195d4f98a2SYan Zheng 23203fd0a558SYan, Zheng /* 23213fd0a558SYan, Zheng * select a tree root for relocation. return NULL if the block 23223fd0a558SYan, Zheng * is reference counted. we should use do_relocation() in this 23233fd0a558SYan, Zheng * case. return a tree root pointer if the block isn't reference 23243fd0a558SYan, Zheng * counted. return -ENOENT if the block is root of reloc tree. 23253fd0a558SYan, Zheng */ 23265d4f98a2SYan Zheng static noinline_for_stack 23275d4f98a2SYan Zheng struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans, 23285d4f98a2SYan Zheng struct backref_node *node) 23295d4f98a2SYan Zheng { 23303fd0a558SYan, Zheng struct backref_node *next; 23313fd0a558SYan, Zheng struct btrfs_root *root; 23323fd0a558SYan, Zheng struct btrfs_root *fs_root = NULL; 23335d4f98a2SYan Zheng struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; 23343fd0a558SYan, Zheng int index = 0; 23353fd0a558SYan, Zheng 23363fd0a558SYan, Zheng next = node; 23373fd0a558SYan, Zheng while (1) { 23383fd0a558SYan, Zheng cond_resched(); 23393fd0a558SYan, Zheng next = walk_up_backref(next, edges, &index); 23403fd0a558SYan, Zheng root = next->root; 23413fd0a558SYan, Zheng BUG_ON(!root); 23423fd0a558SYan, Zheng 23433fd0a558SYan, Zheng /* no other choice for non-refernce counted tree */ 23443fd0a558SYan, Zheng if (!root->ref_cows) 23453fd0a558SYan, Zheng return root; 23463fd0a558SYan, Zheng 23473fd0a558SYan, Zheng if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) 23483fd0a558SYan, Zheng fs_root = root; 23493fd0a558SYan, Zheng 23503fd0a558SYan, Zheng if (next != node) 23513fd0a558SYan, Zheng return NULL; 23523fd0a558SYan, Zheng 23533fd0a558SYan, Zheng next = walk_down_backref(edges, &index); 23543fd0a558SYan, Zheng if (!next || next->level <= node->level) 23553fd0a558SYan, Zheng break; 23563fd0a558SYan, Zheng } 23573fd0a558SYan, Zheng 23583fd0a558SYan, Zheng if (!fs_root) 23593fd0a558SYan, Zheng return ERR_PTR(-ENOENT); 23603fd0a558SYan, Zheng return fs_root; 23615d4f98a2SYan Zheng } 23625d4f98a2SYan Zheng 23635d4f98a2SYan Zheng static noinline_for_stack 23643fd0a558SYan, Zheng u64 calcu_metadata_size(struct reloc_control *rc, 23653fd0a558SYan, Zheng struct backref_node *node, int reserve) 23665d4f98a2SYan Zheng { 23673fd0a558SYan, Zheng struct backref_node *next = node; 23683fd0a558SYan, Zheng struct backref_edge *edge; 23693fd0a558SYan, Zheng struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; 23703fd0a558SYan, Zheng u64 num_bytes = 0; 23713fd0a558SYan, Zheng int index = 0; 23725d4f98a2SYan Zheng 23733fd0a558SYan, Zheng BUG_ON(reserve && node->processed); 23743fd0a558SYan, Zheng 23753fd0a558SYan, Zheng while (next) { 23763fd0a558SYan, Zheng cond_resched(); 23775d4f98a2SYan Zheng while (1) { 23783fd0a558SYan, Zheng if (next->processed && (reserve || next != node)) 23795d4f98a2SYan Zheng break; 23805d4f98a2SYan Zheng 23813fd0a558SYan, Zheng num_bytes += btrfs_level_size(rc->extent_root, 23823fd0a558SYan, Zheng next->level); 23833fd0a558SYan, Zheng 23843fd0a558SYan, Zheng if (list_empty(&next->upper)) 23853fd0a558SYan, Zheng break; 23863fd0a558SYan, Zheng 23873fd0a558SYan, Zheng edge = list_entry(next->upper.next, 23883fd0a558SYan, Zheng struct backref_edge, list[LOWER]); 23893fd0a558SYan, Zheng edges[index++] = edge; 23903fd0a558SYan, Zheng next = edge->node[UPPER]; 23915d4f98a2SYan Zheng } 23923fd0a558SYan, Zheng next = walk_down_backref(edges, &index); 23933fd0a558SYan, Zheng } 23943fd0a558SYan, Zheng return num_bytes; 23953fd0a558SYan, Zheng } 23963fd0a558SYan, Zheng 23973fd0a558SYan, Zheng static int reserve_metadata_space(struct btrfs_trans_handle *trans, 23983fd0a558SYan, Zheng struct reloc_control *rc, 23993fd0a558SYan, Zheng struct backref_node *node) 24003fd0a558SYan, Zheng { 24013fd0a558SYan, Zheng struct btrfs_root *root = rc->extent_root; 24023fd0a558SYan, Zheng u64 num_bytes; 24033fd0a558SYan, Zheng int ret; 24043fd0a558SYan, Zheng 24053fd0a558SYan, Zheng num_bytes = calcu_metadata_size(rc, node, 1) * 2; 24063fd0a558SYan, Zheng 24073fd0a558SYan, Zheng trans->block_rsv = rc->block_rsv; 24083fd0a558SYan, Zheng ret = btrfs_block_rsv_add(trans, root, rc->block_rsv, num_bytes, 24093fd0a558SYan, Zheng &rc->block_rsv_retries); 24103fd0a558SYan, Zheng if (ret) { 24113fd0a558SYan, Zheng if (ret == -EAGAIN) 24123fd0a558SYan, Zheng rc->commit_transaction = 1; 24133fd0a558SYan, Zheng return ret; 24143fd0a558SYan, Zheng } 24153fd0a558SYan, Zheng 24163fd0a558SYan, Zheng rc->block_rsv_retries = 0; 24173fd0a558SYan, Zheng return 0; 24183fd0a558SYan, Zheng } 24193fd0a558SYan, Zheng 24203fd0a558SYan, Zheng static void release_metadata_space(struct reloc_control *rc, 24213fd0a558SYan, Zheng struct backref_node *node) 24223fd0a558SYan, Zheng { 24233fd0a558SYan, Zheng u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2; 24243fd0a558SYan, Zheng btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes); 24255d4f98a2SYan Zheng } 24265d4f98a2SYan Zheng 24275d4f98a2SYan Zheng /* 24285d4f98a2SYan Zheng * relocate a block tree, and then update pointers in upper level 24295d4f98a2SYan Zheng * blocks that reference the block to point to the new location. 24305d4f98a2SYan Zheng * 24315d4f98a2SYan Zheng * if called by link_to_upper, the block has already been relocated. 24325d4f98a2SYan Zheng * in that case this function just updates pointers. 24335d4f98a2SYan Zheng */ 24345d4f98a2SYan Zheng static int do_relocation(struct btrfs_trans_handle *trans, 24353fd0a558SYan, Zheng struct reloc_control *rc, 24365d4f98a2SYan Zheng struct backref_node *node, 24375d4f98a2SYan Zheng struct btrfs_key *key, 24385d4f98a2SYan Zheng struct btrfs_path *path, int lowest) 24395d4f98a2SYan Zheng { 24405d4f98a2SYan Zheng struct backref_node *upper; 24415d4f98a2SYan Zheng struct backref_edge *edge; 24425d4f98a2SYan Zheng struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; 24435d4f98a2SYan Zheng struct btrfs_root *root; 24445d4f98a2SYan Zheng struct extent_buffer *eb; 24455d4f98a2SYan Zheng u32 blocksize; 24465d4f98a2SYan Zheng u64 bytenr; 24475d4f98a2SYan Zheng u64 generation; 24485d4f98a2SYan Zheng int nr; 24495d4f98a2SYan Zheng int slot; 24505d4f98a2SYan Zheng int ret; 24515d4f98a2SYan Zheng int err = 0; 24525d4f98a2SYan Zheng 24535d4f98a2SYan Zheng BUG_ON(lowest && node->eb); 24545d4f98a2SYan Zheng 24555d4f98a2SYan Zheng path->lowest_level = node->level + 1; 24563fd0a558SYan, Zheng rc->backref_cache.path[node->level] = node; 24575d4f98a2SYan Zheng list_for_each_entry(edge, &node->upper, list[LOWER]) { 24585d4f98a2SYan Zheng cond_resched(); 24595d4f98a2SYan Zheng 24605d4f98a2SYan Zheng upper = edge->node[UPPER]; 24613fd0a558SYan, Zheng root = select_reloc_root(trans, rc, upper, edges, &nr); 24623fd0a558SYan, Zheng BUG_ON(!root); 24635d4f98a2SYan Zheng 24643fd0a558SYan, Zheng if (upper->eb && !upper->locked) { 24653fd0a558SYan, Zheng if (!lowest) { 24663fd0a558SYan, Zheng ret = btrfs_bin_search(upper->eb, key, 24673fd0a558SYan, Zheng upper->level, &slot); 24683fd0a558SYan, Zheng BUG_ON(ret); 24693fd0a558SYan, Zheng bytenr = btrfs_node_blockptr(upper->eb, slot); 24703fd0a558SYan, Zheng if (node->eb->start == bytenr) 24713fd0a558SYan, Zheng goto next; 24723fd0a558SYan, Zheng } 24735d4f98a2SYan Zheng drop_node_buffer(upper); 24743fd0a558SYan, Zheng } 24755d4f98a2SYan Zheng 24765d4f98a2SYan Zheng if (!upper->eb) { 24775d4f98a2SYan Zheng ret = btrfs_search_slot(trans, root, key, path, 0, 1); 24785d4f98a2SYan Zheng if (ret < 0) { 24795d4f98a2SYan Zheng err = ret; 24805d4f98a2SYan Zheng break; 24815d4f98a2SYan Zheng } 24825d4f98a2SYan Zheng BUG_ON(ret > 0); 24835d4f98a2SYan Zheng 24843fd0a558SYan, Zheng if (!upper->eb) { 24853fd0a558SYan, Zheng upper->eb = path->nodes[upper->level]; 24863fd0a558SYan, Zheng path->nodes[upper->level] = NULL; 24873fd0a558SYan, Zheng } else { 24883fd0a558SYan, Zheng BUG_ON(upper->eb != path->nodes[upper->level]); 24893fd0a558SYan, Zheng } 24903fd0a558SYan, Zheng 24913fd0a558SYan, Zheng upper->locked = 1; 24923fd0a558SYan, Zheng path->locks[upper->level] = 0; 24933fd0a558SYan, Zheng 24945d4f98a2SYan Zheng slot = path->slots[upper->level]; 24955d4f98a2SYan Zheng btrfs_release_path(NULL, path); 24965d4f98a2SYan Zheng } else { 24975d4f98a2SYan Zheng ret = btrfs_bin_search(upper->eb, key, upper->level, 24985d4f98a2SYan Zheng &slot); 24995d4f98a2SYan Zheng BUG_ON(ret); 25005d4f98a2SYan Zheng } 25015d4f98a2SYan Zheng 25025d4f98a2SYan Zheng bytenr = btrfs_node_blockptr(upper->eb, slot); 25033fd0a558SYan, Zheng if (lowest) { 25043fd0a558SYan, Zheng BUG_ON(bytenr != node->bytenr); 25055d4f98a2SYan Zheng } else { 25063fd0a558SYan, Zheng if (node->eb->start == bytenr) 25073fd0a558SYan, Zheng goto next; 25085d4f98a2SYan Zheng } 25095d4f98a2SYan Zheng 25105d4f98a2SYan Zheng blocksize = btrfs_level_size(root, node->level); 25115d4f98a2SYan Zheng generation = btrfs_node_ptr_generation(upper->eb, slot); 25125d4f98a2SYan Zheng eb = read_tree_block(root, bytenr, blocksize, generation); 25135d4f98a2SYan Zheng btrfs_tree_lock(eb); 25145d4f98a2SYan Zheng btrfs_set_lock_blocking(eb); 25155d4f98a2SYan Zheng 25165d4f98a2SYan Zheng if (!node->eb) { 25175d4f98a2SYan Zheng ret = btrfs_cow_block(trans, root, eb, upper->eb, 25185d4f98a2SYan Zheng slot, &eb); 25193fd0a558SYan, Zheng btrfs_tree_unlock(eb); 25203fd0a558SYan, Zheng free_extent_buffer(eb); 25215d4f98a2SYan Zheng if (ret < 0) { 25225d4f98a2SYan Zheng err = ret; 25233fd0a558SYan, Zheng goto next; 25245d4f98a2SYan Zheng } 25253fd0a558SYan, Zheng BUG_ON(node->eb != eb); 25265d4f98a2SYan Zheng } else { 25275d4f98a2SYan Zheng btrfs_set_node_blockptr(upper->eb, slot, 25285d4f98a2SYan Zheng node->eb->start); 25295d4f98a2SYan Zheng btrfs_set_node_ptr_generation(upper->eb, slot, 25305d4f98a2SYan Zheng trans->transid); 25315d4f98a2SYan Zheng btrfs_mark_buffer_dirty(upper->eb); 25325d4f98a2SYan Zheng 25335d4f98a2SYan Zheng ret = btrfs_inc_extent_ref(trans, root, 25345d4f98a2SYan Zheng node->eb->start, blocksize, 25355d4f98a2SYan Zheng upper->eb->start, 25365d4f98a2SYan Zheng btrfs_header_owner(upper->eb), 25375d4f98a2SYan Zheng node->level, 0); 25385d4f98a2SYan Zheng BUG_ON(ret); 25395d4f98a2SYan Zheng 25405d4f98a2SYan Zheng ret = btrfs_drop_subtree(trans, root, eb, upper->eb); 25415d4f98a2SYan Zheng BUG_ON(ret); 25425d4f98a2SYan Zheng } 25433fd0a558SYan, Zheng next: 25443fd0a558SYan, Zheng if (!upper->pending) 25453fd0a558SYan, Zheng drop_node_buffer(upper); 25463fd0a558SYan, Zheng else 25473fd0a558SYan, Zheng unlock_node_buffer(upper); 25483fd0a558SYan, Zheng if (err) 25493fd0a558SYan, Zheng break; 25505d4f98a2SYan Zheng } 25513fd0a558SYan, Zheng 25523fd0a558SYan, Zheng if (!err && node->pending) { 25533fd0a558SYan, Zheng drop_node_buffer(node); 25543fd0a558SYan, Zheng list_move_tail(&node->list, &rc->backref_cache.changed); 25553fd0a558SYan, Zheng node->pending = 0; 25565d4f98a2SYan Zheng } 25573fd0a558SYan, Zheng 25585d4f98a2SYan Zheng path->lowest_level = 0; 25593fd0a558SYan, Zheng BUG_ON(err == -ENOSPC); 25605d4f98a2SYan Zheng return err; 25615d4f98a2SYan Zheng } 25625d4f98a2SYan Zheng 25635d4f98a2SYan Zheng static int link_to_upper(struct btrfs_trans_handle *trans, 25643fd0a558SYan, Zheng struct reloc_control *rc, 25655d4f98a2SYan Zheng struct backref_node *node, 25665d4f98a2SYan Zheng struct btrfs_path *path) 25675d4f98a2SYan Zheng { 25685d4f98a2SYan Zheng struct btrfs_key key; 25695d4f98a2SYan Zheng 25705d4f98a2SYan Zheng btrfs_node_key_to_cpu(node->eb, &key, 0); 25713fd0a558SYan, Zheng return do_relocation(trans, rc, node, &key, path, 0); 25725d4f98a2SYan Zheng } 25735d4f98a2SYan Zheng 25745d4f98a2SYan Zheng static int finish_pending_nodes(struct btrfs_trans_handle *trans, 25753fd0a558SYan, Zheng struct reloc_control *rc, 25763fd0a558SYan, Zheng struct btrfs_path *path, int err) 25775d4f98a2SYan Zheng { 25783fd0a558SYan, Zheng LIST_HEAD(list); 25793fd0a558SYan, Zheng struct backref_cache *cache = &rc->backref_cache; 25805d4f98a2SYan Zheng struct backref_node *node; 25815d4f98a2SYan Zheng int level; 25825d4f98a2SYan Zheng int ret; 25835d4f98a2SYan Zheng 25845d4f98a2SYan Zheng for (level = 0; level < BTRFS_MAX_LEVEL; level++) { 25855d4f98a2SYan Zheng while (!list_empty(&cache->pending[level])) { 25865d4f98a2SYan Zheng node = list_entry(cache->pending[level].next, 25873fd0a558SYan, Zheng struct backref_node, list); 25883fd0a558SYan, Zheng list_move_tail(&node->list, &list); 25893fd0a558SYan, Zheng BUG_ON(!node->pending); 25905d4f98a2SYan Zheng 25913fd0a558SYan, Zheng if (!err) { 25923fd0a558SYan, Zheng ret = link_to_upper(trans, rc, node, path); 25935d4f98a2SYan Zheng if (ret < 0) 25945d4f98a2SYan Zheng err = ret; 25955d4f98a2SYan Zheng } 25965d4f98a2SYan Zheng } 25973fd0a558SYan, Zheng list_splice_init(&list, &cache->pending[level]); 25983fd0a558SYan, Zheng } 25995d4f98a2SYan Zheng return err; 26005d4f98a2SYan Zheng } 26015d4f98a2SYan Zheng 26025d4f98a2SYan Zheng static void mark_block_processed(struct reloc_control *rc, 26033fd0a558SYan, Zheng u64 bytenr, u32 blocksize) 26043fd0a558SYan, Zheng { 26053fd0a558SYan, Zheng set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1, 26063fd0a558SYan, Zheng EXTENT_DIRTY, GFP_NOFS); 26073fd0a558SYan, Zheng } 26083fd0a558SYan, Zheng 26093fd0a558SYan, Zheng static void __mark_block_processed(struct reloc_control *rc, 26105d4f98a2SYan Zheng struct backref_node *node) 26115d4f98a2SYan Zheng { 26125d4f98a2SYan Zheng u32 blocksize; 26135d4f98a2SYan Zheng if (node->level == 0 || 26145d4f98a2SYan Zheng in_block_group(node->bytenr, rc->block_group)) { 26155d4f98a2SYan Zheng blocksize = btrfs_level_size(rc->extent_root, node->level); 26163fd0a558SYan, Zheng mark_block_processed(rc, node->bytenr, blocksize); 26175d4f98a2SYan Zheng } 26185d4f98a2SYan Zheng node->processed = 1; 26195d4f98a2SYan Zheng } 26205d4f98a2SYan Zheng 26215d4f98a2SYan Zheng /* 26225d4f98a2SYan Zheng * mark a block and all blocks directly/indirectly reference the block 26235d4f98a2SYan Zheng * as processed. 26245d4f98a2SYan Zheng */ 26255d4f98a2SYan Zheng static void update_processed_blocks(struct reloc_control *rc, 26265d4f98a2SYan Zheng struct backref_node *node) 26275d4f98a2SYan Zheng { 26285d4f98a2SYan Zheng struct backref_node *next = node; 26295d4f98a2SYan Zheng struct backref_edge *edge; 26305d4f98a2SYan Zheng struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; 26315d4f98a2SYan Zheng int index = 0; 26325d4f98a2SYan Zheng 26335d4f98a2SYan Zheng while (next) { 26345d4f98a2SYan Zheng cond_resched(); 26355d4f98a2SYan Zheng while (1) { 26365d4f98a2SYan Zheng if (next->processed) 26375d4f98a2SYan Zheng break; 26385d4f98a2SYan Zheng 26393fd0a558SYan, Zheng __mark_block_processed(rc, next); 26405d4f98a2SYan Zheng 26415d4f98a2SYan Zheng if (list_empty(&next->upper)) 26425d4f98a2SYan Zheng break; 26435d4f98a2SYan Zheng 26445d4f98a2SYan Zheng edge = list_entry(next->upper.next, 26455d4f98a2SYan Zheng struct backref_edge, list[LOWER]); 26465d4f98a2SYan Zheng edges[index++] = edge; 26475d4f98a2SYan Zheng next = edge->node[UPPER]; 26485d4f98a2SYan Zheng } 26495d4f98a2SYan Zheng next = walk_down_backref(edges, &index); 26505d4f98a2SYan Zheng } 26515d4f98a2SYan Zheng } 26525d4f98a2SYan Zheng 26535d4f98a2SYan Zheng static int tree_block_processed(u64 bytenr, u32 blocksize, 26545d4f98a2SYan Zheng struct reloc_control *rc) 26555d4f98a2SYan Zheng { 26565d4f98a2SYan Zheng if (test_range_bit(&rc->processed_blocks, bytenr, 26579655d298SChris Mason bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL)) 26585d4f98a2SYan Zheng return 1; 26595d4f98a2SYan Zheng return 0; 26605d4f98a2SYan Zheng } 26615d4f98a2SYan Zheng 26625d4f98a2SYan Zheng static int get_tree_block_key(struct reloc_control *rc, 26635d4f98a2SYan Zheng struct tree_block *block) 26645d4f98a2SYan Zheng { 26655d4f98a2SYan Zheng struct extent_buffer *eb; 26665d4f98a2SYan Zheng 26675d4f98a2SYan Zheng BUG_ON(block->key_ready); 26685d4f98a2SYan Zheng eb = read_tree_block(rc->extent_root, block->bytenr, 26695d4f98a2SYan Zheng block->key.objectid, block->key.offset); 26705d4f98a2SYan Zheng WARN_ON(btrfs_header_level(eb) != block->level); 26715d4f98a2SYan Zheng if (block->level == 0) 26725d4f98a2SYan Zheng btrfs_item_key_to_cpu(eb, &block->key, 0); 26735d4f98a2SYan Zheng else 26745d4f98a2SYan Zheng btrfs_node_key_to_cpu(eb, &block->key, 0); 26755d4f98a2SYan Zheng free_extent_buffer(eb); 26765d4f98a2SYan Zheng block->key_ready = 1; 26775d4f98a2SYan Zheng return 0; 26785d4f98a2SYan Zheng } 26795d4f98a2SYan Zheng 26805d4f98a2SYan Zheng static int reada_tree_block(struct reloc_control *rc, 26815d4f98a2SYan Zheng struct tree_block *block) 26825d4f98a2SYan Zheng { 26835d4f98a2SYan Zheng BUG_ON(block->key_ready); 26845d4f98a2SYan Zheng readahead_tree_block(rc->extent_root, block->bytenr, 26855d4f98a2SYan Zheng block->key.objectid, block->key.offset); 26865d4f98a2SYan Zheng return 0; 26875d4f98a2SYan Zheng } 26885d4f98a2SYan Zheng 26895d4f98a2SYan Zheng /* 26905d4f98a2SYan Zheng * helper function to relocate a tree block 26915d4f98a2SYan Zheng */ 26925d4f98a2SYan Zheng static int relocate_tree_block(struct btrfs_trans_handle *trans, 26935d4f98a2SYan Zheng struct reloc_control *rc, 26945d4f98a2SYan Zheng struct backref_node *node, 26955d4f98a2SYan Zheng struct btrfs_key *key, 26965d4f98a2SYan Zheng struct btrfs_path *path) 26975d4f98a2SYan Zheng { 26985d4f98a2SYan Zheng struct btrfs_root *root; 26993fd0a558SYan, Zheng int release = 0; 27003fd0a558SYan, Zheng int ret = 0; 27015d4f98a2SYan Zheng 27023fd0a558SYan, Zheng if (!node) 27035d4f98a2SYan Zheng return 0; 27043fd0a558SYan, Zheng 27053fd0a558SYan, Zheng BUG_ON(node->processed); 27063fd0a558SYan, Zheng root = select_one_root(trans, node); 27073fd0a558SYan, Zheng if (root == ERR_PTR(-ENOENT)) { 27083fd0a558SYan, Zheng update_processed_blocks(rc, node); 27093fd0a558SYan, Zheng goto out; 27105d4f98a2SYan Zheng } 27115d4f98a2SYan Zheng 27123fd0a558SYan, Zheng if (!root || root->ref_cows) { 27133fd0a558SYan, Zheng ret = reserve_metadata_space(trans, rc, node); 27143fd0a558SYan, Zheng if (ret) 27155d4f98a2SYan Zheng goto out; 27163fd0a558SYan, Zheng release = 1; 27175d4f98a2SYan Zheng } 27183fd0a558SYan, Zheng 27193fd0a558SYan, Zheng if (root) { 27203fd0a558SYan, Zheng if (root->ref_cows) { 27213fd0a558SYan, Zheng BUG_ON(node->new_bytenr); 27223fd0a558SYan, Zheng BUG_ON(!list_empty(&node->list)); 27233fd0a558SYan, Zheng btrfs_record_root_in_trans(trans, root); 27243fd0a558SYan, Zheng root = root->reloc_root; 27253fd0a558SYan, Zheng node->new_bytenr = root->node->start; 27263fd0a558SYan, Zheng node->root = root; 27273fd0a558SYan, Zheng list_add_tail(&node->list, &rc->backref_cache.changed); 27283fd0a558SYan, Zheng } else { 27295d4f98a2SYan Zheng path->lowest_level = node->level; 27305d4f98a2SYan Zheng ret = btrfs_search_slot(trans, root, key, path, 0, 1); 27315d4f98a2SYan Zheng btrfs_release_path(root, path); 27323fd0a558SYan, Zheng if (ret > 0) 27335d4f98a2SYan Zheng ret = 0; 27343fd0a558SYan, Zheng } 27353fd0a558SYan, Zheng if (!ret) 27363fd0a558SYan, Zheng update_processed_blocks(rc, node); 27373fd0a558SYan, Zheng } else { 27383fd0a558SYan, Zheng ret = do_relocation(trans, rc, node, key, path, 1); 27393fd0a558SYan, Zheng } 27405d4f98a2SYan Zheng out: 27413fd0a558SYan, Zheng if (ret || node->level == 0 || node->cowonly) { 27423fd0a558SYan, Zheng if (release) 27433fd0a558SYan, Zheng release_metadata_space(rc, node); 27443fd0a558SYan, Zheng remove_backref_node(&rc->backref_cache, node); 27453fd0a558SYan, Zheng } 27465d4f98a2SYan Zheng return ret; 27475d4f98a2SYan Zheng } 27485d4f98a2SYan Zheng 27495d4f98a2SYan Zheng /* 27505d4f98a2SYan Zheng * relocate a list of blocks 27515d4f98a2SYan Zheng */ 27525d4f98a2SYan Zheng static noinline_for_stack 27535d4f98a2SYan Zheng int relocate_tree_blocks(struct btrfs_trans_handle *trans, 27545d4f98a2SYan Zheng struct reloc_control *rc, struct rb_root *blocks) 27555d4f98a2SYan Zheng { 27565d4f98a2SYan Zheng struct backref_node *node; 27575d4f98a2SYan Zheng struct btrfs_path *path; 27585d4f98a2SYan Zheng struct tree_block *block; 27595d4f98a2SYan Zheng struct rb_node *rb_node; 27605d4f98a2SYan Zheng int ret; 27615d4f98a2SYan Zheng int err = 0; 27625d4f98a2SYan Zheng 27635d4f98a2SYan Zheng path = btrfs_alloc_path(); 27645d4f98a2SYan Zheng if (!path) 27655d4f98a2SYan Zheng return -ENOMEM; 27665d4f98a2SYan Zheng 27675d4f98a2SYan Zheng rb_node = rb_first(blocks); 27685d4f98a2SYan Zheng while (rb_node) { 27695d4f98a2SYan Zheng block = rb_entry(rb_node, struct tree_block, rb_node); 27705d4f98a2SYan Zheng if (!block->key_ready) 27715d4f98a2SYan Zheng reada_tree_block(rc, block); 27725d4f98a2SYan Zheng rb_node = rb_next(rb_node); 27735d4f98a2SYan Zheng } 27745d4f98a2SYan Zheng 27755d4f98a2SYan Zheng rb_node = rb_first(blocks); 27765d4f98a2SYan Zheng while (rb_node) { 27775d4f98a2SYan Zheng block = rb_entry(rb_node, struct tree_block, rb_node); 27785d4f98a2SYan Zheng if (!block->key_ready) 27795d4f98a2SYan Zheng get_tree_block_key(rc, block); 27805d4f98a2SYan Zheng rb_node = rb_next(rb_node); 27815d4f98a2SYan Zheng } 27825d4f98a2SYan Zheng 27835d4f98a2SYan Zheng rb_node = rb_first(blocks); 27845d4f98a2SYan Zheng while (rb_node) { 27855d4f98a2SYan Zheng block = rb_entry(rb_node, struct tree_block, rb_node); 27865d4f98a2SYan Zheng 27873fd0a558SYan, Zheng node = build_backref_tree(rc, &block->key, 27885d4f98a2SYan Zheng block->level, block->bytenr); 27895d4f98a2SYan Zheng if (IS_ERR(node)) { 27905d4f98a2SYan Zheng err = PTR_ERR(node); 27915d4f98a2SYan Zheng goto out; 27925d4f98a2SYan Zheng } 27935d4f98a2SYan Zheng 27945d4f98a2SYan Zheng ret = relocate_tree_block(trans, rc, node, &block->key, 27955d4f98a2SYan Zheng path); 27965d4f98a2SYan Zheng if (ret < 0) { 27973fd0a558SYan, Zheng if (ret != -EAGAIN || rb_node == rb_first(blocks)) 27985d4f98a2SYan Zheng err = ret; 27995d4f98a2SYan Zheng goto out; 28005d4f98a2SYan Zheng } 28015d4f98a2SYan Zheng rb_node = rb_next(rb_node); 28025d4f98a2SYan Zheng } 28035d4f98a2SYan Zheng out: 28045d4f98a2SYan Zheng free_block_list(blocks); 28053fd0a558SYan, Zheng err = finish_pending_nodes(trans, rc, path, err); 28065d4f98a2SYan Zheng 28075d4f98a2SYan Zheng btrfs_free_path(path); 28085d4f98a2SYan Zheng return err; 28095d4f98a2SYan Zheng } 28105d4f98a2SYan Zheng 28115d4f98a2SYan Zheng static noinline_for_stack 2812efa56464SYan, Zheng int prealloc_file_extent_cluster(struct inode *inode, 2813efa56464SYan, Zheng struct file_extent_cluster *cluster) 2814efa56464SYan, Zheng { 2815efa56464SYan, Zheng u64 alloc_hint = 0; 2816efa56464SYan, Zheng u64 start; 2817efa56464SYan, Zheng u64 end; 2818efa56464SYan, Zheng u64 offset = BTRFS_I(inode)->index_cnt; 2819efa56464SYan, Zheng u64 num_bytes; 2820efa56464SYan, Zheng int nr = 0; 2821efa56464SYan, Zheng int ret = 0; 2822efa56464SYan, Zheng 2823efa56464SYan, Zheng BUG_ON(cluster->start != cluster->boundary[0]); 2824efa56464SYan, Zheng mutex_lock(&inode->i_mutex); 2825efa56464SYan, Zheng 2826efa56464SYan, Zheng ret = btrfs_check_data_free_space(inode, cluster->end + 2827efa56464SYan, Zheng 1 - cluster->start); 2828efa56464SYan, Zheng if (ret) 2829efa56464SYan, Zheng goto out; 2830efa56464SYan, Zheng 2831efa56464SYan, Zheng while (nr < cluster->nr) { 2832efa56464SYan, Zheng start = cluster->boundary[nr] - offset; 2833efa56464SYan, Zheng if (nr + 1 < cluster->nr) 2834efa56464SYan, Zheng end = cluster->boundary[nr + 1] - 1 - offset; 2835efa56464SYan, Zheng else 2836efa56464SYan, Zheng end = cluster->end - offset; 2837efa56464SYan, Zheng 2838efa56464SYan, Zheng lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); 2839efa56464SYan, Zheng num_bytes = end + 1 - start; 2840efa56464SYan, Zheng ret = btrfs_prealloc_file_range(inode, 0, start, 2841efa56464SYan, Zheng num_bytes, num_bytes, 2842efa56464SYan, Zheng end + 1, &alloc_hint); 2843efa56464SYan, Zheng unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); 2844efa56464SYan, Zheng if (ret) 2845efa56464SYan, Zheng break; 2846efa56464SYan, Zheng nr++; 2847efa56464SYan, Zheng } 2848efa56464SYan, Zheng btrfs_free_reserved_data_space(inode, cluster->end + 2849efa56464SYan, Zheng 1 - cluster->start); 2850efa56464SYan, Zheng out: 2851efa56464SYan, Zheng mutex_unlock(&inode->i_mutex); 2852efa56464SYan, Zheng return ret; 2853efa56464SYan, Zheng } 2854efa56464SYan, Zheng 2855efa56464SYan, Zheng static noinline_for_stack 28560257bb82SYan, Zheng int setup_extent_mapping(struct inode *inode, u64 start, u64 end, 28570257bb82SYan, Zheng u64 block_start) 28585d4f98a2SYan Zheng { 28595d4f98a2SYan Zheng struct btrfs_root *root = BTRFS_I(inode)->root; 28605d4f98a2SYan Zheng struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; 28615d4f98a2SYan Zheng struct extent_map *em; 28620257bb82SYan, Zheng int ret = 0; 28635d4f98a2SYan Zheng 28645d4f98a2SYan Zheng em = alloc_extent_map(GFP_NOFS); 28650257bb82SYan, Zheng if (!em) 28660257bb82SYan, Zheng return -ENOMEM; 28670257bb82SYan, Zheng 28685d4f98a2SYan Zheng em->start = start; 28690257bb82SYan, Zheng em->len = end + 1 - start; 28700257bb82SYan, Zheng em->block_len = em->len; 28710257bb82SYan, Zheng em->block_start = block_start; 28725d4f98a2SYan Zheng em->bdev = root->fs_info->fs_devices->latest_bdev; 28735d4f98a2SYan Zheng set_bit(EXTENT_FLAG_PINNED, &em->flags); 28745d4f98a2SYan Zheng 28755d4f98a2SYan Zheng lock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); 28765d4f98a2SYan Zheng while (1) { 2877890871beSChris Mason write_lock(&em_tree->lock); 28785d4f98a2SYan Zheng ret = add_extent_mapping(em_tree, em); 2879890871beSChris Mason write_unlock(&em_tree->lock); 28805d4f98a2SYan Zheng if (ret != -EEXIST) { 28815d4f98a2SYan Zheng free_extent_map(em); 28825d4f98a2SYan Zheng break; 28835d4f98a2SYan Zheng } 28845d4f98a2SYan Zheng btrfs_drop_extent_cache(inode, start, end, 0); 28855d4f98a2SYan Zheng } 28865d4f98a2SYan Zheng unlock_extent(&BTRFS_I(inode)->io_tree, start, end, GFP_NOFS); 28870257bb82SYan, Zheng return ret; 28880257bb82SYan, Zheng } 28895d4f98a2SYan Zheng 28900257bb82SYan, Zheng static int relocate_file_extent_cluster(struct inode *inode, 28910257bb82SYan, Zheng struct file_extent_cluster *cluster) 28920257bb82SYan, Zheng { 28930257bb82SYan, Zheng u64 page_start; 28940257bb82SYan, Zheng u64 page_end; 28950257bb82SYan, Zheng u64 offset = BTRFS_I(inode)->index_cnt; 28960257bb82SYan, Zheng unsigned long index; 28970257bb82SYan, Zheng unsigned long last_index; 28980257bb82SYan, Zheng struct page *page; 28990257bb82SYan, Zheng struct file_ra_state *ra; 29000257bb82SYan, Zheng int nr = 0; 29010257bb82SYan, Zheng int ret = 0; 29020257bb82SYan, Zheng 29030257bb82SYan, Zheng if (!cluster->nr) 29040257bb82SYan, Zheng return 0; 29050257bb82SYan, Zheng 29060257bb82SYan, Zheng ra = kzalloc(sizeof(*ra), GFP_NOFS); 29070257bb82SYan, Zheng if (!ra) 29080257bb82SYan, Zheng return -ENOMEM; 29090257bb82SYan, Zheng 2910efa56464SYan, Zheng ret = prealloc_file_extent_cluster(inode, cluster); 29110257bb82SYan, Zheng if (ret) 2912efa56464SYan, Zheng goto out; 29130257bb82SYan, Zheng 29140257bb82SYan, Zheng file_ra_state_init(ra, inode->i_mapping); 29150257bb82SYan, Zheng 2916efa56464SYan, Zheng ret = setup_extent_mapping(inode, cluster->start - offset, 2917efa56464SYan, Zheng cluster->end - offset, cluster->start); 2918efa56464SYan, Zheng if (ret) 2919efa56464SYan, Zheng goto out; 2920efa56464SYan, Zheng 2921efa56464SYan, Zheng index = (cluster->start - offset) >> PAGE_CACHE_SHIFT; 2922efa56464SYan, Zheng last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT; 29230257bb82SYan, Zheng while (index <= last_index) { 2924efa56464SYan, Zheng ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE); 2925efa56464SYan, Zheng if (ret) 2926efa56464SYan, Zheng goto out; 2927efa56464SYan, Zheng 29280257bb82SYan, Zheng page = find_lock_page(inode->i_mapping, index); 29290257bb82SYan, Zheng if (!page) { 29300257bb82SYan, Zheng page_cache_sync_readahead(inode->i_mapping, 29310257bb82SYan, Zheng ra, NULL, index, 29320257bb82SYan, Zheng last_index + 1 - index); 29330257bb82SYan, Zheng page = grab_cache_page(inode->i_mapping, index); 29340257bb82SYan, Zheng if (!page) { 2935efa56464SYan, Zheng btrfs_delalloc_release_metadata(inode, 2936efa56464SYan, Zheng PAGE_CACHE_SIZE); 29370257bb82SYan, Zheng ret = -ENOMEM; 2938efa56464SYan, Zheng goto out; 29390257bb82SYan, Zheng } 29400257bb82SYan, Zheng } 29410257bb82SYan, Zheng 29420257bb82SYan, Zheng if (PageReadahead(page)) { 29430257bb82SYan, Zheng page_cache_async_readahead(inode->i_mapping, 29440257bb82SYan, Zheng ra, NULL, page, index, 29450257bb82SYan, Zheng last_index + 1 - index); 29460257bb82SYan, Zheng } 29470257bb82SYan, Zheng 29480257bb82SYan, Zheng if (!PageUptodate(page)) { 29490257bb82SYan, Zheng btrfs_readpage(NULL, page); 29500257bb82SYan, Zheng lock_page(page); 29510257bb82SYan, Zheng if (!PageUptodate(page)) { 29520257bb82SYan, Zheng unlock_page(page); 29530257bb82SYan, Zheng page_cache_release(page); 2954efa56464SYan, Zheng btrfs_delalloc_release_metadata(inode, 2955efa56464SYan, Zheng PAGE_CACHE_SIZE); 29560257bb82SYan, Zheng ret = -EIO; 2957efa56464SYan, Zheng goto out; 29580257bb82SYan, Zheng } 29590257bb82SYan, Zheng } 29600257bb82SYan, Zheng 29610257bb82SYan, Zheng page_start = (u64)page->index << PAGE_CACHE_SHIFT; 29620257bb82SYan, Zheng page_end = page_start + PAGE_CACHE_SIZE - 1; 29630257bb82SYan, Zheng 29640257bb82SYan, Zheng lock_extent(&BTRFS_I(inode)->io_tree, 29650257bb82SYan, Zheng page_start, page_end, GFP_NOFS); 29660257bb82SYan, Zheng 29670257bb82SYan, Zheng set_page_extent_mapped(page); 29680257bb82SYan, Zheng 29690257bb82SYan, Zheng if (nr < cluster->nr && 29700257bb82SYan, Zheng page_start + offset == cluster->boundary[nr]) { 29710257bb82SYan, Zheng set_extent_bits(&BTRFS_I(inode)->io_tree, 29720257bb82SYan, Zheng page_start, page_end, 29730257bb82SYan, Zheng EXTENT_BOUNDARY, GFP_NOFS); 29740257bb82SYan, Zheng nr++; 29750257bb82SYan, Zheng } 29760257bb82SYan, Zheng 2977efa56464SYan, Zheng btrfs_set_extent_delalloc(inode, page_start, page_end, NULL); 29780257bb82SYan, Zheng set_page_dirty(page); 29790257bb82SYan, Zheng 29800257bb82SYan, Zheng unlock_extent(&BTRFS_I(inode)->io_tree, 29810257bb82SYan, Zheng page_start, page_end, GFP_NOFS); 29820257bb82SYan, Zheng unlock_page(page); 29830257bb82SYan, Zheng page_cache_release(page); 29840257bb82SYan, Zheng 29850257bb82SYan, Zheng index++; 2986efa56464SYan, Zheng balance_dirty_pages_ratelimited(inode->i_mapping); 2987efa56464SYan, Zheng btrfs_throttle(BTRFS_I(inode)->root); 29880257bb82SYan, Zheng } 29890257bb82SYan, Zheng WARN_ON(nr != cluster->nr); 2990efa56464SYan, Zheng out: 29910257bb82SYan, Zheng kfree(ra); 29920257bb82SYan, Zheng return ret; 29930257bb82SYan, Zheng } 29940257bb82SYan, Zheng 29950257bb82SYan, Zheng static noinline_for_stack 29960257bb82SYan, Zheng int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key, 29970257bb82SYan, Zheng struct file_extent_cluster *cluster) 29980257bb82SYan, Zheng { 29990257bb82SYan, Zheng int ret; 30000257bb82SYan, Zheng 30010257bb82SYan, Zheng if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) { 30020257bb82SYan, Zheng ret = relocate_file_extent_cluster(inode, cluster); 30030257bb82SYan, Zheng if (ret) 30040257bb82SYan, Zheng return ret; 30050257bb82SYan, Zheng cluster->nr = 0; 30060257bb82SYan, Zheng } 30070257bb82SYan, Zheng 30080257bb82SYan, Zheng if (!cluster->nr) 30090257bb82SYan, Zheng cluster->start = extent_key->objectid; 30100257bb82SYan, Zheng else 30110257bb82SYan, Zheng BUG_ON(cluster->nr >= MAX_EXTENTS); 30120257bb82SYan, Zheng cluster->end = extent_key->objectid + extent_key->offset - 1; 30130257bb82SYan, Zheng cluster->boundary[cluster->nr] = extent_key->objectid; 30140257bb82SYan, Zheng cluster->nr++; 30150257bb82SYan, Zheng 30160257bb82SYan, Zheng if (cluster->nr >= MAX_EXTENTS) { 30170257bb82SYan, Zheng ret = relocate_file_extent_cluster(inode, cluster); 30180257bb82SYan, Zheng if (ret) 30190257bb82SYan, Zheng return ret; 30200257bb82SYan, Zheng cluster->nr = 0; 30210257bb82SYan, Zheng } 30220257bb82SYan, Zheng return 0; 30235d4f98a2SYan Zheng } 30245d4f98a2SYan Zheng 30255d4f98a2SYan Zheng #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 30265d4f98a2SYan Zheng static int get_ref_objectid_v0(struct reloc_control *rc, 30275d4f98a2SYan Zheng struct btrfs_path *path, 30285d4f98a2SYan Zheng struct btrfs_key *extent_key, 30295d4f98a2SYan Zheng u64 *ref_objectid, int *path_change) 30305d4f98a2SYan Zheng { 30315d4f98a2SYan Zheng struct btrfs_key key; 30325d4f98a2SYan Zheng struct extent_buffer *leaf; 30335d4f98a2SYan Zheng struct btrfs_extent_ref_v0 *ref0; 30345d4f98a2SYan Zheng int ret; 30355d4f98a2SYan Zheng int slot; 30365d4f98a2SYan Zheng 30375d4f98a2SYan Zheng leaf = path->nodes[0]; 30385d4f98a2SYan Zheng slot = path->slots[0]; 30395d4f98a2SYan Zheng while (1) { 30405d4f98a2SYan Zheng if (slot >= btrfs_header_nritems(leaf)) { 30415d4f98a2SYan Zheng ret = btrfs_next_leaf(rc->extent_root, path); 30425d4f98a2SYan Zheng if (ret < 0) 30435d4f98a2SYan Zheng return ret; 30445d4f98a2SYan Zheng BUG_ON(ret > 0); 30455d4f98a2SYan Zheng leaf = path->nodes[0]; 30465d4f98a2SYan Zheng slot = path->slots[0]; 30475d4f98a2SYan Zheng if (path_change) 30485d4f98a2SYan Zheng *path_change = 1; 30495d4f98a2SYan Zheng } 30505d4f98a2SYan Zheng btrfs_item_key_to_cpu(leaf, &key, slot); 30515d4f98a2SYan Zheng if (key.objectid != extent_key->objectid) 30525d4f98a2SYan Zheng return -ENOENT; 30535d4f98a2SYan Zheng 30545d4f98a2SYan Zheng if (key.type != BTRFS_EXTENT_REF_V0_KEY) { 30555d4f98a2SYan Zheng slot++; 30565d4f98a2SYan Zheng continue; 30575d4f98a2SYan Zheng } 30585d4f98a2SYan Zheng ref0 = btrfs_item_ptr(leaf, slot, 30595d4f98a2SYan Zheng struct btrfs_extent_ref_v0); 30605d4f98a2SYan Zheng *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0); 30615d4f98a2SYan Zheng break; 30625d4f98a2SYan Zheng } 30635d4f98a2SYan Zheng return 0; 30645d4f98a2SYan Zheng } 30655d4f98a2SYan Zheng #endif 30665d4f98a2SYan Zheng 30675d4f98a2SYan Zheng /* 30685d4f98a2SYan Zheng * helper to add a tree block to the list. 30695d4f98a2SYan Zheng * the major work is getting the generation and level of the block 30705d4f98a2SYan Zheng */ 30715d4f98a2SYan Zheng static int add_tree_block(struct reloc_control *rc, 30725d4f98a2SYan Zheng struct btrfs_key *extent_key, 30735d4f98a2SYan Zheng struct btrfs_path *path, 30745d4f98a2SYan Zheng struct rb_root *blocks) 30755d4f98a2SYan Zheng { 30765d4f98a2SYan Zheng struct extent_buffer *eb; 30775d4f98a2SYan Zheng struct btrfs_extent_item *ei; 30785d4f98a2SYan Zheng struct btrfs_tree_block_info *bi; 30795d4f98a2SYan Zheng struct tree_block *block; 30805d4f98a2SYan Zheng struct rb_node *rb_node; 30815d4f98a2SYan Zheng u32 item_size; 30825d4f98a2SYan Zheng int level = -1; 30835d4f98a2SYan Zheng int generation; 30845d4f98a2SYan Zheng 30855d4f98a2SYan Zheng eb = path->nodes[0]; 30865d4f98a2SYan Zheng item_size = btrfs_item_size_nr(eb, path->slots[0]); 30875d4f98a2SYan Zheng 30885d4f98a2SYan Zheng if (item_size >= sizeof(*ei) + sizeof(*bi)) { 30895d4f98a2SYan Zheng ei = btrfs_item_ptr(eb, path->slots[0], 30905d4f98a2SYan Zheng struct btrfs_extent_item); 30915d4f98a2SYan Zheng bi = (struct btrfs_tree_block_info *)(ei + 1); 30925d4f98a2SYan Zheng generation = btrfs_extent_generation(eb, ei); 30935d4f98a2SYan Zheng level = btrfs_tree_block_level(eb, bi); 30945d4f98a2SYan Zheng } else { 30955d4f98a2SYan Zheng #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 30965d4f98a2SYan Zheng u64 ref_owner; 30975d4f98a2SYan Zheng int ret; 30985d4f98a2SYan Zheng 30995d4f98a2SYan Zheng BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0)); 31005d4f98a2SYan Zheng ret = get_ref_objectid_v0(rc, path, extent_key, 31015d4f98a2SYan Zheng &ref_owner, NULL); 31025d4f98a2SYan Zheng BUG_ON(ref_owner >= BTRFS_MAX_LEVEL); 31035d4f98a2SYan Zheng level = (int)ref_owner; 31045d4f98a2SYan Zheng /* FIXME: get real generation */ 31055d4f98a2SYan Zheng generation = 0; 31065d4f98a2SYan Zheng #else 31075d4f98a2SYan Zheng BUG(); 31085d4f98a2SYan Zheng #endif 31095d4f98a2SYan Zheng } 31105d4f98a2SYan Zheng 31115d4f98a2SYan Zheng btrfs_release_path(rc->extent_root, path); 31125d4f98a2SYan Zheng 31135d4f98a2SYan Zheng BUG_ON(level == -1); 31145d4f98a2SYan Zheng 31155d4f98a2SYan Zheng block = kmalloc(sizeof(*block), GFP_NOFS); 31165d4f98a2SYan Zheng if (!block) 31175d4f98a2SYan Zheng return -ENOMEM; 31185d4f98a2SYan Zheng 31195d4f98a2SYan Zheng block->bytenr = extent_key->objectid; 31205d4f98a2SYan Zheng block->key.objectid = extent_key->offset; 31215d4f98a2SYan Zheng block->key.offset = generation; 31225d4f98a2SYan Zheng block->level = level; 31235d4f98a2SYan Zheng block->key_ready = 0; 31245d4f98a2SYan Zheng 31255d4f98a2SYan Zheng rb_node = tree_insert(blocks, block->bytenr, &block->rb_node); 31265d4f98a2SYan Zheng BUG_ON(rb_node); 31275d4f98a2SYan Zheng 31285d4f98a2SYan Zheng return 0; 31295d4f98a2SYan Zheng } 31305d4f98a2SYan Zheng 31315d4f98a2SYan Zheng /* 31325d4f98a2SYan Zheng * helper to add tree blocks for backref of type BTRFS_SHARED_DATA_REF_KEY 31335d4f98a2SYan Zheng */ 31345d4f98a2SYan Zheng static int __add_tree_block(struct reloc_control *rc, 31355d4f98a2SYan Zheng u64 bytenr, u32 blocksize, 31365d4f98a2SYan Zheng struct rb_root *blocks) 31375d4f98a2SYan Zheng { 31385d4f98a2SYan Zheng struct btrfs_path *path; 31395d4f98a2SYan Zheng struct btrfs_key key; 31405d4f98a2SYan Zheng int ret; 31415d4f98a2SYan Zheng 31425d4f98a2SYan Zheng if (tree_block_processed(bytenr, blocksize, rc)) 31435d4f98a2SYan Zheng return 0; 31445d4f98a2SYan Zheng 31455d4f98a2SYan Zheng if (tree_search(blocks, bytenr)) 31465d4f98a2SYan Zheng return 0; 31475d4f98a2SYan Zheng 31485d4f98a2SYan Zheng path = btrfs_alloc_path(); 31495d4f98a2SYan Zheng if (!path) 31505d4f98a2SYan Zheng return -ENOMEM; 31515d4f98a2SYan Zheng 31525d4f98a2SYan Zheng key.objectid = bytenr; 31535d4f98a2SYan Zheng key.type = BTRFS_EXTENT_ITEM_KEY; 31545d4f98a2SYan Zheng key.offset = blocksize; 31555d4f98a2SYan Zheng 31565d4f98a2SYan Zheng path->search_commit_root = 1; 31575d4f98a2SYan Zheng path->skip_locking = 1; 31585d4f98a2SYan Zheng ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0); 31595d4f98a2SYan Zheng if (ret < 0) 31605d4f98a2SYan Zheng goto out; 31615d4f98a2SYan Zheng BUG_ON(ret); 31625d4f98a2SYan Zheng 31635d4f98a2SYan Zheng btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); 31645d4f98a2SYan Zheng ret = add_tree_block(rc, &key, path, blocks); 31655d4f98a2SYan Zheng out: 31665d4f98a2SYan Zheng btrfs_free_path(path); 31675d4f98a2SYan Zheng return ret; 31685d4f98a2SYan Zheng } 31695d4f98a2SYan Zheng 31705d4f98a2SYan Zheng /* 31715d4f98a2SYan Zheng * helper to check if the block use full backrefs for pointers in it 31725d4f98a2SYan Zheng */ 31735d4f98a2SYan Zheng static int block_use_full_backref(struct reloc_control *rc, 31745d4f98a2SYan Zheng struct extent_buffer *eb) 31755d4f98a2SYan Zheng { 31765d4f98a2SYan Zheng u64 flags; 31775d4f98a2SYan Zheng int ret; 31785d4f98a2SYan Zheng 31795d4f98a2SYan Zheng if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) || 31805d4f98a2SYan Zheng btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV) 31815d4f98a2SYan Zheng return 1; 31825d4f98a2SYan Zheng 31833fd0a558SYan, Zheng ret = btrfs_lookup_extent_info(NULL, rc->extent_root, 31843fd0a558SYan, Zheng eb->start, eb->len, NULL, &flags); 31855d4f98a2SYan Zheng BUG_ON(ret); 31865d4f98a2SYan Zheng 31875d4f98a2SYan Zheng if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) 31885d4f98a2SYan Zheng ret = 1; 31895d4f98a2SYan Zheng else 31905d4f98a2SYan Zheng ret = 0; 31915d4f98a2SYan Zheng return ret; 31925d4f98a2SYan Zheng } 31935d4f98a2SYan Zheng 31945d4f98a2SYan Zheng /* 31955d4f98a2SYan Zheng * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY 31965d4f98a2SYan Zheng * this function scans fs tree to find blocks reference the data extent 31975d4f98a2SYan Zheng */ 31985d4f98a2SYan Zheng static int find_data_references(struct reloc_control *rc, 31995d4f98a2SYan Zheng struct btrfs_key *extent_key, 32005d4f98a2SYan Zheng struct extent_buffer *leaf, 32015d4f98a2SYan Zheng struct btrfs_extent_data_ref *ref, 32025d4f98a2SYan Zheng struct rb_root *blocks) 32035d4f98a2SYan Zheng { 32045d4f98a2SYan Zheng struct btrfs_path *path; 32055d4f98a2SYan Zheng struct tree_block *block; 32065d4f98a2SYan Zheng struct btrfs_root *root; 32075d4f98a2SYan Zheng struct btrfs_file_extent_item *fi; 32085d4f98a2SYan Zheng struct rb_node *rb_node; 32095d4f98a2SYan Zheng struct btrfs_key key; 32105d4f98a2SYan Zheng u64 ref_root; 32115d4f98a2SYan Zheng u64 ref_objectid; 32125d4f98a2SYan Zheng u64 ref_offset; 32135d4f98a2SYan Zheng u32 ref_count; 32145d4f98a2SYan Zheng u32 nritems; 32155d4f98a2SYan Zheng int err = 0; 32165d4f98a2SYan Zheng int added = 0; 32175d4f98a2SYan Zheng int counted; 32185d4f98a2SYan Zheng int ret; 32195d4f98a2SYan Zheng 32205d4f98a2SYan Zheng path = btrfs_alloc_path(); 32215d4f98a2SYan Zheng if (!path) 32225d4f98a2SYan Zheng return -ENOMEM; 32235d4f98a2SYan Zheng 32245d4f98a2SYan Zheng ref_root = btrfs_extent_data_ref_root(leaf, ref); 32255d4f98a2SYan Zheng ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref); 32265d4f98a2SYan Zheng ref_offset = btrfs_extent_data_ref_offset(leaf, ref); 32275d4f98a2SYan Zheng ref_count = btrfs_extent_data_ref_count(leaf, ref); 32285d4f98a2SYan Zheng 32295d4f98a2SYan Zheng root = read_fs_root(rc->extent_root->fs_info, ref_root); 32305d4f98a2SYan Zheng if (IS_ERR(root)) { 32315d4f98a2SYan Zheng err = PTR_ERR(root); 32325d4f98a2SYan Zheng goto out; 32335d4f98a2SYan Zheng } 32345d4f98a2SYan Zheng 32355d4f98a2SYan Zheng key.objectid = ref_objectid; 32365d4f98a2SYan Zheng key.offset = ref_offset; 32375d4f98a2SYan Zheng key.type = BTRFS_EXTENT_DATA_KEY; 32385d4f98a2SYan Zheng 32395d4f98a2SYan Zheng path->search_commit_root = 1; 32405d4f98a2SYan Zheng path->skip_locking = 1; 32415d4f98a2SYan Zheng ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); 32425d4f98a2SYan Zheng if (ret < 0) { 32435d4f98a2SYan Zheng err = ret; 32445d4f98a2SYan Zheng goto out; 32455d4f98a2SYan Zheng } 32465d4f98a2SYan Zheng 32475d4f98a2SYan Zheng leaf = path->nodes[0]; 32485d4f98a2SYan Zheng nritems = btrfs_header_nritems(leaf); 32495d4f98a2SYan Zheng /* 32505d4f98a2SYan Zheng * the references in tree blocks that use full backrefs 32515d4f98a2SYan Zheng * are not counted in 32525d4f98a2SYan Zheng */ 32535d4f98a2SYan Zheng if (block_use_full_backref(rc, leaf)) 32545d4f98a2SYan Zheng counted = 0; 32555d4f98a2SYan Zheng else 32565d4f98a2SYan Zheng counted = 1; 32575d4f98a2SYan Zheng rb_node = tree_search(blocks, leaf->start); 32585d4f98a2SYan Zheng if (rb_node) { 32595d4f98a2SYan Zheng if (counted) 32605d4f98a2SYan Zheng added = 1; 32615d4f98a2SYan Zheng else 32625d4f98a2SYan Zheng path->slots[0] = nritems; 32635d4f98a2SYan Zheng } 32645d4f98a2SYan Zheng 32655d4f98a2SYan Zheng while (ref_count > 0) { 32665d4f98a2SYan Zheng while (path->slots[0] >= nritems) { 32675d4f98a2SYan Zheng ret = btrfs_next_leaf(root, path); 32685d4f98a2SYan Zheng if (ret < 0) { 32695d4f98a2SYan Zheng err = ret; 32705d4f98a2SYan Zheng goto out; 32715d4f98a2SYan Zheng } 32725d4f98a2SYan Zheng if (ret > 0) { 32735d4f98a2SYan Zheng WARN_ON(1); 32745d4f98a2SYan Zheng goto out; 32755d4f98a2SYan Zheng } 32765d4f98a2SYan Zheng 32775d4f98a2SYan Zheng leaf = path->nodes[0]; 32785d4f98a2SYan Zheng nritems = btrfs_header_nritems(leaf); 32795d4f98a2SYan Zheng added = 0; 32805d4f98a2SYan Zheng 32815d4f98a2SYan Zheng if (block_use_full_backref(rc, leaf)) 32825d4f98a2SYan Zheng counted = 0; 32835d4f98a2SYan Zheng else 32845d4f98a2SYan Zheng counted = 1; 32855d4f98a2SYan Zheng rb_node = tree_search(blocks, leaf->start); 32865d4f98a2SYan Zheng if (rb_node) { 32875d4f98a2SYan Zheng if (counted) 32885d4f98a2SYan Zheng added = 1; 32895d4f98a2SYan Zheng else 32905d4f98a2SYan Zheng path->slots[0] = nritems; 32915d4f98a2SYan Zheng } 32925d4f98a2SYan Zheng } 32935d4f98a2SYan Zheng 32945d4f98a2SYan Zheng btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 32955d4f98a2SYan Zheng if (key.objectid != ref_objectid || 32965d4f98a2SYan Zheng key.type != BTRFS_EXTENT_DATA_KEY) { 32975d4f98a2SYan Zheng WARN_ON(1); 32985d4f98a2SYan Zheng break; 32995d4f98a2SYan Zheng } 33005d4f98a2SYan Zheng 33015d4f98a2SYan Zheng fi = btrfs_item_ptr(leaf, path->slots[0], 33025d4f98a2SYan Zheng struct btrfs_file_extent_item); 33035d4f98a2SYan Zheng 33045d4f98a2SYan Zheng if (btrfs_file_extent_type(leaf, fi) == 33055d4f98a2SYan Zheng BTRFS_FILE_EXTENT_INLINE) 33065d4f98a2SYan Zheng goto next; 33075d4f98a2SYan Zheng 33085d4f98a2SYan Zheng if (btrfs_file_extent_disk_bytenr(leaf, fi) != 33095d4f98a2SYan Zheng extent_key->objectid) 33105d4f98a2SYan Zheng goto next; 33115d4f98a2SYan Zheng 33125d4f98a2SYan Zheng key.offset -= btrfs_file_extent_offset(leaf, fi); 33135d4f98a2SYan Zheng if (key.offset != ref_offset) 33145d4f98a2SYan Zheng goto next; 33155d4f98a2SYan Zheng 33165d4f98a2SYan Zheng if (counted) 33175d4f98a2SYan Zheng ref_count--; 33185d4f98a2SYan Zheng if (added) 33195d4f98a2SYan Zheng goto next; 33205d4f98a2SYan Zheng 33215d4f98a2SYan Zheng if (!tree_block_processed(leaf->start, leaf->len, rc)) { 33225d4f98a2SYan Zheng block = kmalloc(sizeof(*block), GFP_NOFS); 33235d4f98a2SYan Zheng if (!block) { 33245d4f98a2SYan Zheng err = -ENOMEM; 33255d4f98a2SYan Zheng break; 33265d4f98a2SYan Zheng } 33275d4f98a2SYan Zheng block->bytenr = leaf->start; 33285d4f98a2SYan Zheng btrfs_item_key_to_cpu(leaf, &block->key, 0); 33295d4f98a2SYan Zheng block->level = 0; 33305d4f98a2SYan Zheng block->key_ready = 1; 33315d4f98a2SYan Zheng rb_node = tree_insert(blocks, block->bytenr, 33325d4f98a2SYan Zheng &block->rb_node); 33335d4f98a2SYan Zheng BUG_ON(rb_node); 33345d4f98a2SYan Zheng } 33355d4f98a2SYan Zheng if (counted) 33365d4f98a2SYan Zheng added = 1; 33375d4f98a2SYan Zheng else 33385d4f98a2SYan Zheng path->slots[0] = nritems; 33395d4f98a2SYan Zheng next: 33405d4f98a2SYan Zheng path->slots[0]++; 33415d4f98a2SYan Zheng 33425d4f98a2SYan Zheng } 33435d4f98a2SYan Zheng out: 33445d4f98a2SYan Zheng btrfs_free_path(path); 33455d4f98a2SYan Zheng return err; 33465d4f98a2SYan Zheng } 33475d4f98a2SYan Zheng 33485d4f98a2SYan Zheng /* 33495d4f98a2SYan Zheng * hepler to find all tree blocks that reference a given data extent 33505d4f98a2SYan Zheng */ 33515d4f98a2SYan Zheng static noinline_for_stack 33525d4f98a2SYan Zheng int add_data_references(struct reloc_control *rc, 33535d4f98a2SYan Zheng struct btrfs_key *extent_key, 33545d4f98a2SYan Zheng struct btrfs_path *path, 33555d4f98a2SYan Zheng struct rb_root *blocks) 33565d4f98a2SYan Zheng { 33575d4f98a2SYan Zheng struct btrfs_key key; 33585d4f98a2SYan Zheng struct extent_buffer *eb; 33595d4f98a2SYan Zheng struct btrfs_extent_data_ref *dref; 33605d4f98a2SYan Zheng struct btrfs_extent_inline_ref *iref; 33615d4f98a2SYan Zheng unsigned long ptr; 33625d4f98a2SYan Zheng unsigned long end; 33633fd0a558SYan, Zheng u32 blocksize = btrfs_level_size(rc->extent_root, 0); 33645d4f98a2SYan Zheng int ret; 33655d4f98a2SYan Zheng int err = 0; 33665d4f98a2SYan Zheng 33675d4f98a2SYan Zheng eb = path->nodes[0]; 33685d4f98a2SYan Zheng ptr = btrfs_item_ptr_offset(eb, path->slots[0]); 33695d4f98a2SYan Zheng end = ptr + btrfs_item_size_nr(eb, path->slots[0]); 33705d4f98a2SYan Zheng #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 33715d4f98a2SYan Zheng if (ptr + sizeof(struct btrfs_extent_item_v0) == end) 33725d4f98a2SYan Zheng ptr = end; 33735d4f98a2SYan Zheng else 33745d4f98a2SYan Zheng #endif 33755d4f98a2SYan Zheng ptr += sizeof(struct btrfs_extent_item); 33765d4f98a2SYan Zheng 33775d4f98a2SYan Zheng while (ptr < end) { 33785d4f98a2SYan Zheng iref = (struct btrfs_extent_inline_ref *)ptr; 33795d4f98a2SYan Zheng key.type = btrfs_extent_inline_ref_type(eb, iref); 33805d4f98a2SYan Zheng if (key.type == BTRFS_SHARED_DATA_REF_KEY) { 33815d4f98a2SYan Zheng key.offset = btrfs_extent_inline_ref_offset(eb, iref); 33825d4f98a2SYan Zheng ret = __add_tree_block(rc, key.offset, blocksize, 33835d4f98a2SYan Zheng blocks); 33845d4f98a2SYan Zheng } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { 33855d4f98a2SYan Zheng dref = (struct btrfs_extent_data_ref *)(&iref->offset); 33865d4f98a2SYan Zheng ret = find_data_references(rc, extent_key, 33875d4f98a2SYan Zheng eb, dref, blocks); 33885d4f98a2SYan Zheng } else { 33895d4f98a2SYan Zheng BUG(); 33905d4f98a2SYan Zheng } 33915d4f98a2SYan Zheng ptr += btrfs_extent_inline_ref_size(key.type); 33925d4f98a2SYan Zheng } 33935d4f98a2SYan Zheng WARN_ON(ptr > end); 33945d4f98a2SYan Zheng 33955d4f98a2SYan Zheng while (1) { 33965d4f98a2SYan Zheng cond_resched(); 33975d4f98a2SYan Zheng eb = path->nodes[0]; 33985d4f98a2SYan Zheng if (path->slots[0] >= btrfs_header_nritems(eb)) { 33995d4f98a2SYan Zheng ret = btrfs_next_leaf(rc->extent_root, path); 34005d4f98a2SYan Zheng if (ret < 0) { 34015d4f98a2SYan Zheng err = ret; 34025d4f98a2SYan Zheng break; 34035d4f98a2SYan Zheng } 34045d4f98a2SYan Zheng if (ret > 0) 34055d4f98a2SYan Zheng break; 34065d4f98a2SYan Zheng eb = path->nodes[0]; 34075d4f98a2SYan Zheng } 34085d4f98a2SYan Zheng 34095d4f98a2SYan Zheng btrfs_item_key_to_cpu(eb, &key, path->slots[0]); 34105d4f98a2SYan Zheng if (key.objectid != extent_key->objectid) 34115d4f98a2SYan Zheng break; 34125d4f98a2SYan Zheng 34135d4f98a2SYan Zheng #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 34145d4f98a2SYan Zheng if (key.type == BTRFS_SHARED_DATA_REF_KEY || 34155d4f98a2SYan Zheng key.type == BTRFS_EXTENT_REF_V0_KEY) { 34165d4f98a2SYan Zheng #else 34175d4f98a2SYan Zheng BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY); 34185d4f98a2SYan Zheng if (key.type == BTRFS_SHARED_DATA_REF_KEY) { 34195d4f98a2SYan Zheng #endif 34205d4f98a2SYan Zheng ret = __add_tree_block(rc, key.offset, blocksize, 34215d4f98a2SYan Zheng blocks); 34225d4f98a2SYan Zheng } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { 34235d4f98a2SYan Zheng dref = btrfs_item_ptr(eb, path->slots[0], 34245d4f98a2SYan Zheng struct btrfs_extent_data_ref); 34255d4f98a2SYan Zheng ret = find_data_references(rc, extent_key, 34265d4f98a2SYan Zheng eb, dref, blocks); 34275d4f98a2SYan Zheng } else { 34285d4f98a2SYan Zheng ret = 0; 34295d4f98a2SYan Zheng } 34305d4f98a2SYan Zheng if (ret) { 34315d4f98a2SYan Zheng err = ret; 34325d4f98a2SYan Zheng break; 34335d4f98a2SYan Zheng } 34345d4f98a2SYan Zheng path->slots[0]++; 34355d4f98a2SYan Zheng } 34365d4f98a2SYan Zheng btrfs_release_path(rc->extent_root, path); 34375d4f98a2SYan Zheng if (err) 34385d4f98a2SYan Zheng free_block_list(blocks); 34395d4f98a2SYan Zheng return err; 34405d4f98a2SYan Zheng } 34415d4f98a2SYan Zheng 34425d4f98a2SYan Zheng /* 34435d4f98a2SYan Zheng * hepler to find next unprocessed extent 34445d4f98a2SYan Zheng */ 34455d4f98a2SYan Zheng static noinline_for_stack 34465d4f98a2SYan Zheng int find_next_extent(struct btrfs_trans_handle *trans, 34473fd0a558SYan, Zheng struct reloc_control *rc, struct btrfs_path *path, 34483fd0a558SYan, Zheng struct btrfs_key *extent_key) 34495d4f98a2SYan Zheng { 34505d4f98a2SYan Zheng struct btrfs_key key; 34515d4f98a2SYan Zheng struct extent_buffer *leaf; 34525d4f98a2SYan Zheng u64 start, end, last; 34535d4f98a2SYan Zheng int ret; 34545d4f98a2SYan Zheng 34555d4f98a2SYan Zheng last = rc->block_group->key.objectid + rc->block_group->key.offset; 34565d4f98a2SYan Zheng while (1) { 34575d4f98a2SYan Zheng cond_resched(); 34585d4f98a2SYan Zheng if (rc->search_start >= last) { 34595d4f98a2SYan Zheng ret = 1; 34605d4f98a2SYan Zheng break; 34615d4f98a2SYan Zheng } 34625d4f98a2SYan Zheng 34635d4f98a2SYan Zheng key.objectid = rc->search_start; 34645d4f98a2SYan Zheng key.type = BTRFS_EXTENT_ITEM_KEY; 34655d4f98a2SYan Zheng key.offset = 0; 34665d4f98a2SYan Zheng 34675d4f98a2SYan Zheng path->search_commit_root = 1; 34685d4f98a2SYan Zheng path->skip_locking = 1; 34695d4f98a2SYan Zheng ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 34705d4f98a2SYan Zheng 0, 0); 34715d4f98a2SYan Zheng if (ret < 0) 34725d4f98a2SYan Zheng break; 34735d4f98a2SYan Zheng next: 34745d4f98a2SYan Zheng leaf = path->nodes[0]; 34755d4f98a2SYan Zheng if (path->slots[0] >= btrfs_header_nritems(leaf)) { 34765d4f98a2SYan Zheng ret = btrfs_next_leaf(rc->extent_root, path); 34775d4f98a2SYan Zheng if (ret != 0) 34785d4f98a2SYan Zheng break; 34795d4f98a2SYan Zheng leaf = path->nodes[0]; 34805d4f98a2SYan Zheng } 34815d4f98a2SYan Zheng 34825d4f98a2SYan Zheng btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 34835d4f98a2SYan Zheng if (key.objectid >= last) { 34845d4f98a2SYan Zheng ret = 1; 34855d4f98a2SYan Zheng break; 34865d4f98a2SYan Zheng } 34875d4f98a2SYan Zheng 34885d4f98a2SYan Zheng if (key.type != BTRFS_EXTENT_ITEM_KEY || 34895d4f98a2SYan Zheng key.objectid + key.offset <= rc->search_start) { 34905d4f98a2SYan Zheng path->slots[0]++; 34915d4f98a2SYan Zheng goto next; 34925d4f98a2SYan Zheng } 34935d4f98a2SYan Zheng 34945d4f98a2SYan Zheng ret = find_first_extent_bit(&rc->processed_blocks, 34955d4f98a2SYan Zheng key.objectid, &start, &end, 34965d4f98a2SYan Zheng EXTENT_DIRTY); 34975d4f98a2SYan Zheng 34985d4f98a2SYan Zheng if (ret == 0 && start <= key.objectid) { 34995d4f98a2SYan Zheng btrfs_release_path(rc->extent_root, path); 35005d4f98a2SYan Zheng rc->search_start = end + 1; 35015d4f98a2SYan Zheng } else { 35025d4f98a2SYan Zheng rc->search_start = key.objectid + key.offset; 35033fd0a558SYan, Zheng memcpy(extent_key, &key, sizeof(key)); 35045d4f98a2SYan Zheng return 0; 35055d4f98a2SYan Zheng } 35065d4f98a2SYan Zheng } 35075d4f98a2SYan Zheng btrfs_release_path(rc->extent_root, path); 35085d4f98a2SYan Zheng return ret; 35095d4f98a2SYan Zheng } 35105d4f98a2SYan Zheng 35115d4f98a2SYan Zheng static void set_reloc_control(struct reloc_control *rc) 35125d4f98a2SYan Zheng { 35135d4f98a2SYan Zheng struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; 35145d4f98a2SYan Zheng mutex_lock(&fs_info->trans_mutex); 35155d4f98a2SYan Zheng fs_info->reloc_ctl = rc; 35165d4f98a2SYan Zheng mutex_unlock(&fs_info->trans_mutex); 35175d4f98a2SYan Zheng } 35185d4f98a2SYan Zheng 35195d4f98a2SYan Zheng static void unset_reloc_control(struct reloc_control *rc) 35205d4f98a2SYan Zheng { 35215d4f98a2SYan Zheng struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; 35225d4f98a2SYan Zheng mutex_lock(&fs_info->trans_mutex); 35235d4f98a2SYan Zheng fs_info->reloc_ctl = NULL; 35245d4f98a2SYan Zheng mutex_unlock(&fs_info->trans_mutex); 35255d4f98a2SYan Zheng } 35265d4f98a2SYan Zheng 35275d4f98a2SYan Zheng static int check_extent_flags(u64 flags) 35285d4f98a2SYan Zheng { 35295d4f98a2SYan Zheng if ((flags & BTRFS_EXTENT_FLAG_DATA) && 35305d4f98a2SYan Zheng (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) 35315d4f98a2SYan Zheng return 1; 35325d4f98a2SYan Zheng if (!(flags & BTRFS_EXTENT_FLAG_DATA) && 35335d4f98a2SYan Zheng !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) 35345d4f98a2SYan Zheng return 1; 35355d4f98a2SYan Zheng if ((flags & BTRFS_EXTENT_FLAG_DATA) && 35365d4f98a2SYan Zheng (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) 35375d4f98a2SYan Zheng return 1; 35385d4f98a2SYan Zheng return 0; 35395d4f98a2SYan Zheng } 35405d4f98a2SYan Zheng 35413fd0a558SYan, Zheng static noinline_for_stack 35423fd0a558SYan, Zheng int prepare_to_relocate(struct reloc_control *rc) 35433fd0a558SYan, Zheng { 35443fd0a558SYan, Zheng struct btrfs_trans_handle *trans; 35453fd0a558SYan, Zheng int ret; 35463fd0a558SYan, Zheng 35473fd0a558SYan, Zheng rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root); 35483fd0a558SYan, Zheng if (!rc->block_rsv) 35493fd0a558SYan, Zheng return -ENOMEM; 35503fd0a558SYan, Zheng 35513fd0a558SYan, Zheng /* 35523fd0a558SYan, Zheng * reserve some space for creating reloc trees. 35533fd0a558SYan, Zheng * btrfs_init_reloc_root will use them when there 35543fd0a558SYan, Zheng * is no reservation in transaction handle. 35553fd0a558SYan, Zheng */ 35563fd0a558SYan, Zheng ret = btrfs_block_rsv_add(NULL, rc->extent_root, rc->block_rsv, 35573fd0a558SYan, Zheng rc->extent_root->nodesize * 256, 35583fd0a558SYan, Zheng &rc->block_rsv_retries); 35593fd0a558SYan, Zheng if (ret) 35603fd0a558SYan, Zheng return ret; 35613fd0a558SYan, Zheng 35623fd0a558SYan, Zheng rc->block_rsv->refill_used = 1; 35633fd0a558SYan, Zheng btrfs_add_durable_block_rsv(rc->extent_root->fs_info, rc->block_rsv); 35643fd0a558SYan, Zheng 35653fd0a558SYan, Zheng memset(&rc->cluster, 0, sizeof(rc->cluster)); 35663fd0a558SYan, Zheng rc->search_start = rc->block_group->key.objectid; 35673fd0a558SYan, Zheng rc->extents_found = 0; 35683fd0a558SYan, Zheng rc->nodes_relocated = 0; 35693fd0a558SYan, Zheng rc->merging_rsv_size = 0; 35703fd0a558SYan, Zheng rc->block_rsv_retries = 0; 35713fd0a558SYan, Zheng 35723fd0a558SYan, Zheng rc->create_reloc_tree = 1; 35733fd0a558SYan, Zheng set_reloc_control(rc); 35743fd0a558SYan, Zheng 35753fd0a558SYan, Zheng trans = btrfs_join_transaction(rc->extent_root, 1); 35763fd0a558SYan, Zheng btrfs_commit_transaction(trans, rc->extent_root); 35773fd0a558SYan, Zheng return 0; 35783fd0a558SYan, Zheng } 357976dda93cSYan, Zheng 35805d4f98a2SYan Zheng static noinline_for_stack int relocate_block_group(struct reloc_control *rc) 35815d4f98a2SYan Zheng { 35825d4f98a2SYan Zheng struct rb_root blocks = RB_ROOT; 35835d4f98a2SYan Zheng struct btrfs_key key; 35845d4f98a2SYan Zheng struct btrfs_trans_handle *trans = NULL; 35855d4f98a2SYan Zheng struct btrfs_path *path; 35865d4f98a2SYan Zheng struct btrfs_extent_item *ei; 35875d4f98a2SYan Zheng unsigned long nr; 35885d4f98a2SYan Zheng u64 flags; 35895d4f98a2SYan Zheng u32 item_size; 35905d4f98a2SYan Zheng int ret; 35915d4f98a2SYan Zheng int err = 0; 35925d4f98a2SYan Zheng 35935d4f98a2SYan Zheng path = btrfs_alloc_path(); 35943fd0a558SYan, Zheng if (!path) 35955d4f98a2SYan Zheng return -ENOMEM; 35963fd0a558SYan, Zheng 35973fd0a558SYan, Zheng ret = prepare_to_relocate(rc); 35983fd0a558SYan, Zheng if (ret) { 35993fd0a558SYan, Zheng err = ret; 36003fd0a558SYan, Zheng goto out_free; 36012423fdfbSJiri Slaby } 36025d4f98a2SYan Zheng 36035d4f98a2SYan Zheng while (1) { 3604a22285a6SYan, Zheng trans = btrfs_start_transaction(rc->extent_root, 0); 36055d4f98a2SYan Zheng 36063fd0a558SYan, Zheng if (update_backref_cache(trans, &rc->backref_cache)) { 36073fd0a558SYan, Zheng btrfs_end_transaction(trans, rc->extent_root); 36083fd0a558SYan, Zheng continue; 36093fd0a558SYan, Zheng } 36103fd0a558SYan, Zheng 36113fd0a558SYan, Zheng ret = find_next_extent(trans, rc, path, &key); 36125d4f98a2SYan Zheng if (ret < 0) 36135d4f98a2SYan Zheng err = ret; 36145d4f98a2SYan Zheng if (ret != 0) 36155d4f98a2SYan Zheng break; 36165d4f98a2SYan Zheng 36175d4f98a2SYan Zheng rc->extents_found++; 36185d4f98a2SYan Zheng 36195d4f98a2SYan Zheng ei = btrfs_item_ptr(path->nodes[0], path->slots[0], 36205d4f98a2SYan Zheng struct btrfs_extent_item); 36213fd0a558SYan, Zheng item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]); 36225d4f98a2SYan Zheng if (item_size >= sizeof(*ei)) { 36235d4f98a2SYan Zheng flags = btrfs_extent_flags(path->nodes[0], ei); 36245d4f98a2SYan Zheng ret = check_extent_flags(flags); 36255d4f98a2SYan Zheng BUG_ON(ret); 36265d4f98a2SYan Zheng 36275d4f98a2SYan Zheng } else { 36285d4f98a2SYan Zheng #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 36295d4f98a2SYan Zheng u64 ref_owner; 36305d4f98a2SYan Zheng int path_change = 0; 36315d4f98a2SYan Zheng 36325d4f98a2SYan Zheng BUG_ON(item_size != 36335d4f98a2SYan Zheng sizeof(struct btrfs_extent_item_v0)); 36345d4f98a2SYan Zheng ret = get_ref_objectid_v0(rc, path, &key, &ref_owner, 36355d4f98a2SYan Zheng &path_change); 36365d4f98a2SYan Zheng if (ref_owner < BTRFS_FIRST_FREE_OBJECTID) 36375d4f98a2SYan Zheng flags = BTRFS_EXTENT_FLAG_TREE_BLOCK; 36385d4f98a2SYan Zheng else 36395d4f98a2SYan Zheng flags = BTRFS_EXTENT_FLAG_DATA; 36405d4f98a2SYan Zheng 36415d4f98a2SYan Zheng if (path_change) { 36425d4f98a2SYan Zheng btrfs_release_path(rc->extent_root, path); 36435d4f98a2SYan Zheng 36445d4f98a2SYan Zheng path->search_commit_root = 1; 36455d4f98a2SYan Zheng path->skip_locking = 1; 36465d4f98a2SYan Zheng ret = btrfs_search_slot(NULL, rc->extent_root, 36475d4f98a2SYan Zheng &key, path, 0, 0); 36485d4f98a2SYan Zheng if (ret < 0) { 36495d4f98a2SYan Zheng err = ret; 36505d4f98a2SYan Zheng break; 36515d4f98a2SYan Zheng } 36525d4f98a2SYan Zheng BUG_ON(ret > 0); 36535d4f98a2SYan Zheng } 36545d4f98a2SYan Zheng #else 36555d4f98a2SYan Zheng BUG(); 36565d4f98a2SYan Zheng #endif 36575d4f98a2SYan Zheng } 36585d4f98a2SYan Zheng 36595d4f98a2SYan Zheng if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { 36605d4f98a2SYan Zheng ret = add_tree_block(rc, &key, path, &blocks); 36615d4f98a2SYan Zheng } else if (rc->stage == UPDATE_DATA_PTRS && 36625d4f98a2SYan Zheng (flags & BTRFS_EXTENT_FLAG_DATA)) { 36635d4f98a2SYan Zheng ret = add_data_references(rc, &key, path, &blocks); 36645d4f98a2SYan Zheng } else { 36655d4f98a2SYan Zheng btrfs_release_path(rc->extent_root, path); 36665d4f98a2SYan Zheng ret = 0; 36675d4f98a2SYan Zheng } 36685d4f98a2SYan Zheng if (ret < 0) { 36693fd0a558SYan, Zheng err = ret; 36705d4f98a2SYan Zheng break; 36715d4f98a2SYan Zheng } 36725d4f98a2SYan Zheng 36735d4f98a2SYan Zheng if (!RB_EMPTY_ROOT(&blocks)) { 36745d4f98a2SYan Zheng ret = relocate_tree_blocks(trans, rc, &blocks); 36755d4f98a2SYan Zheng if (ret < 0) { 36763fd0a558SYan, Zheng if (ret != -EAGAIN) { 36775d4f98a2SYan Zheng err = ret; 36785d4f98a2SYan Zheng break; 36795d4f98a2SYan Zheng } 36803fd0a558SYan, Zheng rc->extents_found--; 36813fd0a558SYan, Zheng rc->search_start = key.objectid; 36823fd0a558SYan, Zheng } 36835d4f98a2SYan Zheng } 36845d4f98a2SYan Zheng 36853fd0a558SYan, Zheng ret = btrfs_block_rsv_check(trans, rc->extent_root, 36863fd0a558SYan, Zheng rc->block_rsv, 0, 5); 36873fd0a558SYan, Zheng if (ret < 0) { 36883fd0a558SYan, Zheng if (ret != -EAGAIN) { 36893fd0a558SYan, Zheng err = ret; 36903fd0a558SYan, Zheng WARN_ON(1); 36913fd0a558SYan, Zheng break; 36923fd0a558SYan, Zheng } 36933fd0a558SYan, Zheng rc->commit_transaction = 1; 36943fd0a558SYan, Zheng } 36953fd0a558SYan, Zheng 36963fd0a558SYan, Zheng if (rc->commit_transaction) { 36973fd0a558SYan, Zheng rc->commit_transaction = 0; 36983fd0a558SYan, Zheng ret = btrfs_commit_transaction(trans, rc->extent_root); 36993fd0a558SYan, Zheng BUG_ON(ret); 37003fd0a558SYan, Zheng } else { 37015d4f98a2SYan Zheng nr = trans->blocks_used; 37023fd0a558SYan, Zheng btrfs_end_transaction_throttle(trans, rc->extent_root); 37035d4f98a2SYan Zheng btrfs_btree_balance_dirty(rc->extent_root, nr); 37043fd0a558SYan, Zheng } 37053fd0a558SYan, Zheng trans = NULL; 37065d4f98a2SYan Zheng 37075d4f98a2SYan Zheng if (rc->stage == MOVE_DATA_EXTENTS && 37085d4f98a2SYan Zheng (flags & BTRFS_EXTENT_FLAG_DATA)) { 37095d4f98a2SYan Zheng rc->found_file_extent = 1; 37100257bb82SYan, Zheng ret = relocate_data_extent(rc->data_inode, 37113fd0a558SYan, Zheng &key, &rc->cluster); 37125d4f98a2SYan Zheng if (ret < 0) { 37135d4f98a2SYan Zheng err = ret; 37145d4f98a2SYan Zheng break; 37155d4f98a2SYan Zheng } 37165d4f98a2SYan Zheng } 37175d4f98a2SYan Zheng } 37183fd0a558SYan, Zheng 37193fd0a558SYan, Zheng btrfs_release_path(rc->extent_root, path); 37203fd0a558SYan, Zheng clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY, 37213fd0a558SYan, Zheng GFP_NOFS); 37225d4f98a2SYan Zheng 37235d4f98a2SYan Zheng if (trans) { 37245d4f98a2SYan Zheng nr = trans->blocks_used; 37253fd0a558SYan, Zheng btrfs_end_transaction_throttle(trans, rc->extent_root); 37265d4f98a2SYan Zheng btrfs_btree_balance_dirty(rc->extent_root, nr); 37275d4f98a2SYan Zheng } 37285d4f98a2SYan Zheng 37290257bb82SYan, Zheng if (!err) { 37303fd0a558SYan, Zheng ret = relocate_file_extent_cluster(rc->data_inode, 37313fd0a558SYan, Zheng &rc->cluster); 37320257bb82SYan, Zheng if (ret < 0) 37330257bb82SYan, Zheng err = ret; 37340257bb82SYan, Zheng } 37350257bb82SYan, Zheng 37363fd0a558SYan, Zheng rc->create_reloc_tree = 0; 37373fd0a558SYan, Zheng set_reloc_control(rc); 37380257bb82SYan, Zheng 37393fd0a558SYan, Zheng backref_cache_cleanup(&rc->backref_cache); 37403fd0a558SYan, Zheng btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1); 37415d4f98a2SYan Zheng 37423fd0a558SYan, Zheng err = prepare_to_merge(rc, err); 37435d4f98a2SYan Zheng 37445d4f98a2SYan Zheng merge_reloc_roots(rc); 37455d4f98a2SYan Zheng 37463fd0a558SYan, Zheng rc->merge_reloc_tree = 0; 37475d4f98a2SYan Zheng unset_reloc_control(rc); 37483fd0a558SYan, Zheng btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1); 37495d4f98a2SYan Zheng 37505d4f98a2SYan Zheng /* get rid of pinned extents */ 3751a22285a6SYan, Zheng trans = btrfs_join_transaction(rc->extent_root, 1); 37525d4f98a2SYan Zheng btrfs_commit_transaction(trans, rc->extent_root); 37533fd0a558SYan, Zheng out_free: 37543fd0a558SYan, Zheng btrfs_free_block_rsv(rc->extent_root, rc->block_rsv); 37553fd0a558SYan, Zheng btrfs_free_path(path); 37565d4f98a2SYan Zheng return err; 37575d4f98a2SYan Zheng } 37585d4f98a2SYan Zheng 37595d4f98a2SYan Zheng static int __insert_orphan_inode(struct btrfs_trans_handle *trans, 37600257bb82SYan, Zheng struct btrfs_root *root, u64 objectid) 37615d4f98a2SYan Zheng { 37625d4f98a2SYan Zheng struct btrfs_path *path; 37635d4f98a2SYan Zheng struct btrfs_inode_item *item; 37645d4f98a2SYan Zheng struct extent_buffer *leaf; 37655d4f98a2SYan Zheng int ret; 37665d4f98a2SYan Zheng 37675d4f98a2SYan Zheng path = btrfs_alloc_path(); 37685d4f98a2SYan Zheng if (!path) 37695d4f98a2SYan Zheng return -ENOMEM; 37705d4f98a2SYan Zheng 37715d4f98a2SYan Zheng ret = btrfs_insert_empty_inode(trans, root, path, objectid); 37725d4f98a2SYan Zheng if (ret) 37735d4f98a2SYan Zheng goto out; 37745d4f98a2SYan Zheng 37755d4f98a2SYan Zheng leaf = path->nodes[0]; 37765d4f98a2SYan Zheng item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); 37775d4f98a2SYan Zheng memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item)); 37785d4f98a2SYan Zheng btrfs_set_inode_generation(leaf, item, 1); 37790257bb82SYan, Zheng btrfs_set_inode_size(leaf, item, 0); 37805d4f98a2SYan Zheng btrfs_set_inode_mode(leaf, item, S_IFREG | 0600); 37813fd0a558SYan, Zheng btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS | 37823fd0a558SYan, Zheng BTRFS_INODE_PREALLOC); 37835d4f98a2SYan Zheng btrfs_mark_buffer_dirty(leaf); 37845d4f98a2SYan Zheng btrfs_release_path(root, path); 37855d4f98a2SYan Zheng out: 37865d4f98a2SYan Zheng btrfs_free_path(path); 37875d4f98a2SYan Zheng return ret; 37885d4f98a2SYan Zheng } 37895d4f98a2SYan Zheng 37905d4f98a2SYan Zheng /* 37915d4f98a2SYan Zheng * helper to create inode for data relocation. 37925d4f98a2SYan Zheng * the inode is in data relocation tree and its link count is 0 37935d4f98a2SYan Zheng */ 37943fd0a558SYan, Zheng static noinline_for_stack 37953fd0a558SYan, Zheng struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info, 37965d4f98a2SYan Zheng struct btrfs_block_group_cache *group) 37975d4f98a2SYan Zheng { 37985d4f98a2SYan Zheng struct inode *inode = NULL; 37995d4f98a2SYan Zheng struct btrfs_trans_handle *trans; 38005d4f98a2SYan Zheng struct btrfs_root *root; 38015d4f98a2SYan Zheng struct btrfs_key key; 38025d4f98a2SYan Zheng unsigned long nr; 38035d4f98a2SYan Zheng u64 objectid = BTRFS_FIRST_FREE_OBJECTID; 38045d4f98a2SYan Zheng int err = 0; 38055d4f98a2SYan Zheng 38065d4f98a2SYan Zheng root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID); 38075d4f98a2SYan Zheng if (IS_ERR(root)) 38085d4f98a2SYan Zheng return ERR_CAST(root); 38095d4f98a2SYan Zheng 3810a22285a6SYan, Zheng trans = btrfs_start_transaction(root, 6); 38113fd0a558SYan, Zheng if (IS_ERR(trans)) 38123fd0a558SYan, Zheng return ERR_CAST(trans); 38135d4f98a2SYan Zheng 38145d4f98a2SYan Zheng err = btrfs_find_free_objectid(trans, root, objectid, &objectid); 38155d4f98a2SYan Zheng if (err) 38165d4f98a2SYan Zheng goto out; 38175d4f98a2SYan Zheng 38180257bb82SYan, Zheng err = __insert_orphan_inode(trans, root, objectid); 38195d4f98a2SYan Zheng BUG_ON(err); 38205d4f98a2SYan Zheng 38215d4f98a2SYan Zheng key.objectid = objectid; 38225d4f98a2SYan Zheng key.type = BTRFS_INODE_ITEM_KEY; 38235d4f98a2SYan Zheng key.offset = 0; 382473f73415SJosef Bacik inode = btrfs_iget(root->fs_info->sb, &key, root, NULL); 38255d4f98a2SYan Zheng BUG_ON(IS_ERR(inode) || is_bad_inode(inode)); 38265d4f98a2SYan Zheng BTRFS_I(inode)->index_cnt = group->key.objectid; 38275d4f98a2SYan Zheng 38285d4f98a2SYan Zheng err = btrfs_orphan_add(trans, inode); 38295d4f98a2SYan Zheng out: 38305d4f98a2SYan Zheng nr = trans->blocks_used; 38315d4f98a2SYan Zheng btrfs_end_transaction(trans, root); 38325d4f98a2SYan Zheng btrfs_btree_balance_dirty(root, nr); 38335d4f98a2SYan Zheng if (err) { 38345d4f98a2SYan Zheng if (inode) 38355d4f98a2SYan Zheng iput(inode); 38365d4f98a2SYan Zheng inode = ERR_PTR(err); 38375d4f98a2SYan Zheng } 38385d4f98a2SYan Zheng return inode; 38395d4f98a2SYan Zheng } 38405d4f98a2SYan Zheng 38413fd0a558SYan, Zheng static struct reloc_control *alloc_reloc_control(void) 38423fd0a558SYan, Zheng { 38433fd0a558SYan, Zheng struct reloc_control *rc; 38443fd0a558SYan, Zheng 38453fd0a558SYan, Zheng rc = kzalloc(sizeof(*rc), GFP_NOFS); 38463fd0a558SYan, Zheng if (!rc) 38473fd0a558SYan, Zheng return NULL; 38483fd0a558SYan, Zheng 38493fd0a558SYan, Zheng INIT_LIST_HEAD(&rc->reloc_roots); 38503fd0a558SYan, Zheng backref_cache_init(&rc->backref_cache); 38513fd0a558SYan, Zheng mapping_tree_init(&rc->reloc_root_tree); 38523fd0a558SYan, Zheng extent_io_tree_init(&rc->processed_blocks, NULL, GFP_NOFS); 38533fd0a558SYan, Zheng return rc; 38543fd0a558SYan, Zheng } 38553fd0a558SYan, Zheng 38565d4f98a2SYan Zheng /* 38575d4f98a2SYan Zheng * function to relocate all extents in a block group. 38585d4f98a2SYan Zheng */ 38595d4f98a2SYan Zheng int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start) 38605d4f98a2SYan Zheng { 38615d4f98a2SYan Zheng struct btrfs_fs_info *fs_info = extent_root->fs_info; 38625d4f98a2SYan Zheng struct reloc_control *rc; 38635d4f98a2SYan Zheng int ret; 3864f0486c68SYan, Zheng int rw = 0; 38655d4f98a2SYan Zheng int err = 0; 38665d4f98a2SYan Zheng 38673fd0a558SYan, Zheng rc = alloc_reloc_control(); 38685d4f98a2SYan Zheng if (!rc) 38695d4f98a2SYan Zheng return -ENOMEM; 38705d4f98a2SYan Zheng 3871f0486c68SYan, Zheng rc->extent_root = extent_root; 38723fd0a558SYan, Zheng 38735d4f98a2SYan Zheng rc->block_group = btrfs_lookup_block_group(fs_info, group_start); 38745d4f98a2SYan Zheng BUG_ON(!rc->block_group); 38755d4f98a2SYan Zheng 3876f0486c68SYan, Zheng if (!rc->block_group->ro) { 3877f0486c68SYan, Zheng ret = btrfs_set_block_group_ro(extent_root, rc->block_group); 3878f0486c68SYan, Zheng if (ret) { 3879f0486c68SYan, Zheng err = ret; 3880f0486c68SYan, Zheng goto out; 3881f0486c68SYan, Zheng } 3882f0486c68SYan, Zheng rw = 1; 3883f0486c68SYan, Zheng } 3884f0486c68SYan, Zheng 38855d4f98a2SYan Zheng rc->data_inode = create_reloc_inode(fs_info, rc->block_group); 38865d4f98a2SYan Zheng if (IS_ERR(rc->data_inode)) { 38875d4f98a2SYan Zheng err = PTR_ERR(rc->data_inode); 38885d4f98a2SYan Zheng rc->data_inode = NULL; 38895d4f98a2SYan Zheng goto out; 38905d4f98a2SYan Zheng } 38915d4f98a2SYan Zheng 38925d4f98a2SYan Zheng printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n", 38935d4f98a2SYan Zheng (unsigned long long)rc->block_group->key.objectid, 38945d4f98a2SYan Zheng (unsigned long long)rc->block_group->flags); 38955d4f98a2SYan Zheng 389624bbcf04SYan, Zheng btrfs_start_delalloc_inodes(fs_info->tree_root, 0); 389724bbcf04SYan, Zheng btrfs_wait_ordered_extents(fs_info->tree_root, 0, 0); 38985d4f98a2SYan Zheng 38995d4f98a2SYan Zheng while (1) { 390076dda93cSYan, Zheng mutex_lock(&fs_info->cleaner_mutex); 390176dda93cSYan, Zheng 390276dda93cSYan, Zheng btrfs_clean_old_snapshots(fs_info->tree_root); 39035d4f98a2SYan Zheng ret = relocate_block_group(rc); 390476dda93cSYan, Zheng 390576dda93cSYan, Zheng mutex_unlock(&fs_info->cleaner_mutex); 39065d4f98a2SYan Zheng if (ret < 0) { 39075d4f98a2SYan Zheng err = ret; 39083fd0a558SYan, Zheng goto out; 39095d4f98a2SYan Zheng } 39105d4f98a2SYan Zheng 39115d4f98a2SYan Zheng if (rc->extents_found == 0) 39125d4f98a2SYan Zheng break; 39135d4f98a2SYan Zheng 39145d4f98a2SYan Zheng printk(KERN_INFO "btrfs: found %llu extents\n", 39155d4f98a2SYan Zheng (unsigned long long)rc->extents_found); 39165d4f98a2SYan Zheng 39175d4f98a2SYan Zheng if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) { 39185d4f98a2SYan Zheng btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1); 39195d4f98a2SYan Zheng invalidate_mapping_pages(rc->data_inode->i_mapping, 39205d4f98a2SYan Zheng 0, -1); 39215d4f98a2SYan Zheng rc->stage = UPDATE_DATA_PTRS; 39225d4f98a2SYan Zheng } 39235d4f98a2SYan Zheng } 39245d4f98a2SYan Zheng 39250257bb82SYan, Zheng filemap_write_and_wait_range(fs_info->btree_inode->i_mapping, 39265d4f98a2SYan Zheng rc->block_group->key.objectid, 39275d4f98a2SYan Zheng rc->block_group->key.objectid + 39285d4f98a2SYan Zheng rc->block_group->key.offset - 1); 39295d4f98a2SYan Zheng 39305d4f98a2SYan Zheng WARN_ON(rc->block_group->pinned > 0); 39315d4f98a2SYan Zheng WARN_ON(rc->block_group->reserved > 0); 39325d4f98a2SYan Zheng WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0); 39335d4f98a2SYan Zheng out: 3934f0486c68SYan, Zheng if (err && rw) 3935f0486c68SYan, Zheng btrfs_set_block_group_rw(extent_root, rc->block_group); 39365d4f98a2SYan Zheng iput(rc->data_inode); 39375d4f98a2SYan Zheng btrfs_put_block_group(rc->block_group); 39385d4f98a2SYan Zheng kfree(rc); 39395d4f98a2SYan Zheng return err; 39405d4f98a2SYan Zheng } 39415d4f98a2SYan Zheng 394276dda93cSYan, Zheng static noinline_for_stack int mark_garbage_root(struct btrfs_root *root) 394376dda93cSYan, Zheng { 394476dda93cSYan, Zheng struct btrfs_trans_handle *trans; 394576dda93cSYan, Zheng int ret; 394676dda93cSYan, Zheng 3947a22285a6SYan, Zheng trans = btrfs_start_transaction(root->fs_info->tree_root, 0); 394876dda93cSYan, Zheng 394976dda93cSYan, Zheng memset(&root->root_item.drop_progress, 0, 395076dda93cSYan, Zheng sizeof(root->root_item.drop_progress)); 395176dda93cSYan, Zheng root->root_item.drop_level = 0; 395276dda93cSYan, Zheng btrfs_set_root_refs(&root->root_item, 0); 395376dda93cSYan, Zheng ret = btrfs_update_root(trans, root->fs_info->tree_root, 395476dda93cSYan, Zheng &root->root_key, &root->root_item); 395576dda93cSYan, Zheng BUG_ON(ret); 395676dda93cSYan, Zheng 395776dda93cSYan, Zheng ret = btrfs_end_transaction(trans, root->fs_info->tree_root); 395876dda93cSYan, Zheng BUG_ON(ret); 395976dda93cSYan, Zheng return 0; 396076dda93cSYan, Zheng } 396176dda93cSYan, Zheng 39625d4f98a2SYan Zheng /* 39635d4f98a2SYan Zheng * recover relocation interrupted by system crash. 39645d4f98a2SYan Zheng * 39655d4f98a2SYan Zheng * this function resumes merging reloc trees with corresponding fs trees. 39665d4f98a2SYan Zheng * this is important for keeping the sharing of tree blocks 39675d4f98a2SYan Zheng */ 39685d4f98a2SYan Zheng int btrfs_recover_relocation(struct btrfs_root *root) 39695d4f98a2SYan Zheng { 39705d4f98a2SYan Zheng LIST_HEAD(reloc_roots); 39715d4f98a2SYan Zheng struct btrfs_key key; 39725d4f98a2SYan Zheng struct btrfs_root *fs_root; 39735d4f98a2SYan Zheng struct btrfs_root *reloc_root; 39745d4f98a2SYan Zheng struct btrfs_path *path; 39755d4f98a2SYan Zheng struct extent_buffer *leaf; 39765d4f98a2SYan Zheng struct reloc_control *rc = NULL; 39775d4f98a2SYan Zheng struct btrfs_trans_handle *trans; 39785d4f98a2SYan Zheng int ret; 39795d4f98a2SYan Zheng int err = 0; 39805d4f98a2SYan Zheng 39815d4f98a2SYan Zheng path = btrfs_alloc_path(); 39825d4f98a2SYan Zheng if (!path) 39835d4f98a2SYan Zheng return -ENOMEM; 39845d4f98a2SYan Zheng 39855d4f98a2SYan Zheng key.objectid = BTRFS_TREE_RELOC_OBJECTID; 39865d4f98a2SYan Zheng key.type = BTRFS_ROOT_ITEM_KEY; 39875d4f98a2SYan Zheng key.offset = (u64)-1; 39885d4f98a2SYan Zheng 39895d4f98a2SYan Zheng while (1) { 39905d4f98a2SYan Zheng ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, 39915d4f98a2SYan Zheng path, 0, 0); 39925d4f98a2SYan Zheng if (ret < 0) { 39935d4f98a2SYan Zheng err = ret; 39945d4f98a2SYan Zheng goto out; 39955d4f98a2SYan Zheng } 39965d4f98a2SYan Zheng if (ret > 0) { 39975d4f98a2SYan Zheng if (path->slots[0] == 0) 39985d4f98a2SYan Zheng break; 39995d4f98a2SYan Zheng path->slots[0]--; 40005d4f98a2SYan Zheng } 40015d4f98a2SYan Zheng leaf = path->nodes[0]; 40025d4f98a2SYan Zheng btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); 40035d4f98a2SYan Zheng btrfs_release_path(root->fs_info->tree_root, path); 40045d4f98a2SYan Zheng 40055d4f98a2SYan Zheng if (key.objectid != BTRFS_TREE_RELOC_OBJECTID || 40065d4f98a2SYan Zheng key.type != BTRFS_ROOT_ITEM_KEY) 40075d4f98a2SYan Zheng break; 40085d4f98a2SYan Zheng 40095d4f98a2SYan Zheng reloc_root = btrfs_read_fs_root_no_radix(root, &key); 40105d4f98a2SYan Zheng if (IS_ERR(reloc_root)) { 40115d4f98a2SYan Zheng err = PTR_ERR(reloc_root); 40125d4f98a2SYan Zheng goto out; 40135d4f98a2SYan Zheng } 40145d4f98a2SYan Zheng 40155d4f98a2SYan Zheng list_add(&reloc_root->root_list, &reloc_roots); 40165d4f98a2SYan Zheng 40175d4f98a2SYan Zheng if (btrfs_root_refs(&reloc_root->root_item) > 0) { 40185d4f98a2SYan Zheng fs_root = read_fs_root(root->fs_info, 40195d4f98a2SYan Zheng reloc_root->root_key.offset); 40205d4f98a2SYan Zheng if (IS_ERR(fs_root)) { 402176dda93cSYan, Zheng ret = PTR_ERR(fs_root); 402276dda93cSYan, Zheng if (ret != -ENOENT) { 402376dda93cSYan, Zheng err = ret; 40245d4f98a2SYan Zheng goto out; 40255d4f98a2SYan Zheng } 402676dda93cSYan, Zheng mark_garbage_root(reloc_root); 402776dda93cSYan, Zheng } 40285d4f98a2SYan Zheng } 40295d4f98a2SYan Zheng 40305d4f98a2SYan Zheng if (key.offset == 0) 40315d4f98a2SYan Zheng break; 40325d4f98a2SYan Zheng 40335d4f98a2SYan Zheng key.offset--; 40345d4f98a2SYan Zheng } 40355d4f98a2SYan Zheng btrfs_release_path(root->fs_info->tree_root, path); 40365d4f98a2SYan Zheng 40375d4f98a2SYan Zheng if (list_empty(&reloc_roots)) 40385d4f98a2SYan Zheng goto out; 40395d4f98a2SYan Zheng 40403fd0a558SYan, Zheng rc = alloc_reloc_control(); 40415d4f98a2SYan Zheng if (!rc) { 40425d4f98a2SYan Zheng err = -ENOMEM; 40435d4f98a2SYan Zheng goto out; 40445d4f98a2SYan Zheng } 40455d4f98a2SYan Zheng 40465d4f98a2SYan Zheng rc->extent_root = root->fs_info->extent_root; 40475d4f98a2SYan Zheng 40485d4f98a2SYan Zheng set_reloc_control(rc); 40495d4f98a2SYan Zheng 40503fd0a558SYan, Zheng trans = btrfs_join_transaction(rc->extent_root, 1); 40513fd0a558SYan, Zheng 40523fd0a558SYan, Zheng rc->merge_reloc_tree = 1; 40533fd0a558SYan, Zheng 40545d4f98a2SYan Zheng while (!list_empty(&reloc_roots)) { 40555d4f98a2SYan Zheng reloc_root = list_entry(reloc_roots.next, 40565d4f98a2SYan Zheng struct btrfs_root, root_list); 40575d4f98a2SYan Zheng list_del(&reloc_root->root_list); 40585d4f98a2SYan Zheng 40595d4f98a2SYan Zheng if (btrfs_root_refs(&reloc_root->root_item) == 0) { 40605d4f98a2SYan Zheng list_add_tail(&reloc_root->root_list, 40615d4f98a2SYan Zheng &rc->reloc_roots); 40625d4f98a2SYan Zheng continue; 40635d4f98a2SYan Zheng } 40645d4f98a2SYan Zheng 40655d4f98a2SYan Zheng fs_root = read_fs_root(root->fs_info, 40665d4f98a2SYan Zheng reloc_root->root_key.offset); 40675d4f98a2SYan Zheng BUG_ON(IS_ERR(fs_root)); 40685d4f98a2SYan Zheng 40695d4f98a2SYan Zheng __add_reloc_root(reloc_root); 40705d4f98a2SYan Zheng fs_root->reloc_root = reloc_root; 40715d4f98a2SYan Zheng } 40725d4f98a2SYan Zheng 40735d4f98a2SYan Zheng btrfs_commit_transaction(trans, rc->extent_root); 40745d4f98a2SYan Zheng 40755d4f98a2SYan Zheng merge_reloc_roots(rc); 40765d4f98a2SYan Zheng 40775d4f98a2SYan Zheng unset_reloc_control(rc); 40785d4f98a2SYan Zheng 40793fd0a558SYan, Zheng trans = btrfs_join_transaction(rc->extent_root, 1); 40805d4f98a2SYan Zheng btrfs_commit_transaction(trans, rc->extent_root); 40815d4f98a2SYan Zheng out: 40825d4f98a2SYan Zheng kfree(rc); 40835d4f98a2SYan Zheng while (!list_empty(&reloc_roots)) { 40845d4f98a2SYan Zheng reloc_root = list_entry(reloc_roots.next, 40855d4f98a2SYan Zheng struct btrfs_root, root_list); 40865d4f98a2SYan Zheng list_del(&reloc_root->root_list); 40875d4f98a2SYan Zheng free_extent_buffer(reloc_root->node); 40885d4f98a2SYan Zheng free_extent_buffer(reloc_root->commit_root); 40895d4f98a2SYan Zheng kfree(reloc_root); 40905d4f98a2SYan Zheng } 40915d4f98a2SYan Zheng btrfs_free_path(path); 40925d4f98a2SYan Zheng 40935d4f98a2SYan Zheng if (err == 0) { 40945d4f98a2SYan Zheng /* cleanup orphan inode in data relocation tree */ 40955d4f98a2SYan Zheng fs_root = read_fs_root(root->fs_info, 40965d4f98a2SYan Zheng BTRFS_DATA_RELOC_TREE_OBJECTID); 40975d4f98a2SYan Zheng if (IS_ERR(fs_root)) 40985d4f98a2SYan Zheng err = PTR_ERR(fs_root); 4099d7ce5843SMiao Xie else 4100c71bf099SYan, Zheng btrfs_orphan_cleanup(fs_root); 41015d4f98a2SYan Zheng } 41025d4f98a2SYan Zheng return err; 41035d4f98a2SYan Zheng } 41045d4f98a2SYan Zheng 41055d4f98a2SYan Zheng /* 41065d4f98a2SYan Zheng * helper to add ordered checksum for data relocation. 41075d4f98a2SYan Zheng * 41085d4f98a2SYan Zheng * cloning checksum properly handles the nodatasum extents. 41095d4f98a2SYan Zheng * it also saves CPU time to re-calculate the checksum. 41105d4f98a2SYan Zheng */ 41115d4f98a2SYan Zheng int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len) 41125d4f98a2SYan Zheng { 41135d4f98a2SYan Zheng struct btrfs_ordered_sum *sums; 41145d4f98a2SYan Zheng struct btrfs_sector_sum *sector_sum; 41155d4f98a2SYan Zheng struct btrfs_ordered_extent *ordered; 41165d4f98a2SYan Zheng struct btrfs_root *root = BTRFS_I(inode)->root; 41175d4f98a2SYan Zheng size_t offset; 41185d4f98a2SYan Zheng int ret; 41195d4f98a2SYan Zheng u64 disk_bytenr; 41205d4f98a2SYan Zheng LIST_HEAD(list); 41215d4f98a2SYan Zheng 41225d4f98a2SYan Zheng ordered = btrfs_lookup_ordered_extent(inode, file_pos); 41235d4f98a2SYan Zheng BUG_ON(ordered->file_offset != file_pos || ordered->len != len); 41245d4f98a2SYan Zheng 41255d4f98a2SYan Zheng disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt; 41265d4f98a2SYan Zheng ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr, 41275d4f98a2SYan Zheng disk_bytenr + len - 1, &list); 41285d4f98a2SYan Zheng 41295d4f98a2SYan Zheng while (!list_empty(&list)) { 41305d4f98a2SYan Zheng sums = list_entry(list.next, struct btrfs_ordered_sum, list); 41315d4f98a2SYan Zheng list_del_init(&sums->list); 41325d4f98a2SYan Zheng 41335d4f98a2SYan Zheng sector_sum = sums->sums; 41345d4f98a2SYan Zheng sums->bytenr = ordered->start; 41355d4f98a2SYan Zheng 41365d4f98a2SYan Zheng offset = 0; 41375d4f98a2SYan Zheng while (offset < sums->len) { 41385d4f98a2SYan Zheng sector_sum->bytenr += ordered->start - disk_bytenr; 41395d4f98a2SYan Zheng sector_sum++; 41405d4f98a2SYan Zheng offset += root->sectorsize; 41415d4f98a2SYan Zheng } 41425d4f98a2SYan Zheng 41435d4f98a2SYan Zheng btrfs_add_ordered_sum(inode, ordered, sums); 41445d4f98a2SYan Zheng } 41455d4f98a2SYan Zheng btrfs_put_ordered_extent(ordered); 41465d4f98a2SYan Zheng return 0; 41475d4f98a2SYan Zheng } 41483fd0a558SYan, Zheng 41493fd0a558SYan, Zheng void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans, 41503fd0a558SYan, Zheng struct btrfs_root *root, struct extent_buffer *buf, 41513fd0a558SYan, Zheng struct extent_buffer *cow) 41523fd0a558SYan, Zheng { 41533fd0a558SYan, Zheng struct reloc_control *rc; 41543fd0a558SYan, Zheng struct backref_node *node; 41553fd0a558SYan, Zheng int first_cow = 0; 41563fd0a558SYan, Zheng int level; 41573fd0a558SYan, Zheng int ret; 41583fd0a558SYan, Zheng 41593fd0a558SYan, Zheng rc = root->fs_info->reloc_ctl; 41603fd0a558SYan, Zheng if (!rc) 41613fd0a558SYan, Zheng return; 41623fd0a558SYan, Zheng 41633fd0a558SYan, Zheng BUG_ON(rc->stage == UPDATE_DATA_PTRS && 41643fd0a558SYan, Zheng root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID); 41653fd0a558SYan, Zheng 41663fd0a558SYan, Zheng level = btrfs_header_level(buf); 41673fd0a558SYan, Zheng if (btrfs_header_generation(buf) <= 41683fd0a558SYan, Zheng btrfs_root_last_snapshot(&root->root_item)) 41693fd0a558SYan, Zheng first_cow = 1; 41703fd0a558SYan, Zheng 41713fd0a558SYan, Zheng if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID && 41723fd0a558SYan, Zheng rc->create_reloc_tree) { 41733fd0a558SYan, Zheng WARN_ON(!first_cow && level == 0); 41743fd0a558SYan, Zheng 41753fd0a558SYan, Zheng node = rc->backref_cache.path[level]; 41763fd0a558SYan, Zheng BUG_ON(node->bytenr != buf->start && 41773fd0a558SYan, Zheng node->new_bytenr != buf->start); 41783fd0a558SYan, Zheng 41793fd0a558SYan, Zheng drop_node_buffer(node); 41803fd0a558SYan, Zheng extent_buffer_get(cow); 41813fd0a558SYan, Zheng node->eb = cow; 41823fd0a558SYan, Zheng node->new_bytenr = cow->start; 41833fd0a558SYan, Zheng 41843fd0a558SYan, Zheng if (!node->pending) { 41853fd0a558SYan, Zheng list_move_tail(&node->list, 41863fd0a558SYan, Zheng &rc->backref_cache.pending[level]); 41873fd0a558SYan, Zheng node->pending = 1; 41883fd0a558SYan, Zheng } 41893fd0a558SYan, Zheng 41903fd0a558SYan, Zheng if (first_cow) 41913fd0a558SYan, Zheng __mark_block_processed(rc, node); 41923fd0a558SYan, Zheng 41933fd0a558SYan, Zheng if (first_cow && level > 0) 41943fd0a558SYan, Zheng rc->nodes_relocated += buf->len; 41953fd0a558SYan, Zheng } 41963fd0a558SYan, Zheng 41973fd0a558SYan, Zheng if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) { 41983fd0a558SYan, Zheng ret = replace_file_extents(trans, rc, root, cow); 41993fd0a558SYan, Zheng BUG_ON(ret); 42003fd0a558SYan, Zheng } 42013fd0a558SYan, Zheng } 42023fd0a558SYan, Zheng 42033fd0a558SYan, Zheng /* 42043fd0a558SYan, Zheng * called before creating snapshot. it calculates metadata reservation 42053fd0a558SYan, Zheng * requried for relocating tree blocks in the snapshot 42063fd0a558SYan, Zheng */ 42073fd0a558SYan, Zheng void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans, 42083fd0a558SYan, Zheng struct btrfs_pending_snapshot *pending, 42093fd0a558SYan, Zheng u64 *bytes_to_reserve) 42103fd0a558SYan, Zheng { 42113fd0a558SYan, Zheng struct btrfs_root *root; 42123fd0a558SYan, Zheng struct reloc_control *rc; 42133fd0a558SYan, Zheng 42143fd0a558SYan, Zheng root = pending->root; 42153fd0a558SYan, Zheng if (!root->reloc_root) 42163fd0a558SYan, Zheng return; 42173fd0a558SYan, Zheng 42183fd0a558SYan, Zheng rc = root->fs_info->reloc_ctl; 42193fd0a558SYan, Zheng if (!rc->merge_reloc_tree) 42203fd0a558SYan, Zheng return; 42213fd0a558SYan, Zheng 42223fd0a558SYan, Zheng root = root->reloc_root; 42233fd0a558SYan, Zheng BUG_ON(btrfs_root_refs(&root->root_item) == 0); 42243fd0a558SYan, Zheng /* 42253fd0a558SYan, Zheng * relocation is in the stage of merging trees. the space 42263fd0a558SYan, Zheng * used by merging a reloc tree is twice the size of 42273fd0a558SYan, Zheng * relocated tree nodes in the worst case. half for cowing 42283fd0a558SYan, Zheng * the reloc tree, half for cowing the fs tree. the space 42293fd0a558SYan, Zheng * used by cowing the reloc tree will be freed after the 42303fd0a558SYan, Zheng * tree is dropped. if we create snapshot, cowing the fs 42313fd0a558SYan, Zheng * tree may use more space than it frees. so we need 42323fd0a558SYan, Zheng * reserve extra space. 42333fd0a558SYan, Zheng */ 42343fd0a558SYan, Zheng *bytes_to_reserve += rc->nodes_relocated; 42353fd0a558SYan, Zheng } 42363fd0a558SYan, Zheng 42373fd0a558SYan, Zheng /* 42383fd0a558SYan, Zheng * called after snapshot is created. migrate block reservation 42393fd0a558SYan, Zheng * and create reloc root for the newly created snapshot 42403fd0a558SYan, Zheng */ 42413fd0a558SYan, Zheng void btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans, 42423fd0a558SYan, Zheng struct btrfs_pending_snapshot *pending) 42433fd0a558SYan, Zheng { 42443fd0a558SYan, Zheng struct btrfs_root *root = pending->root; 42453fd0a558SYan, Zheng struct btrfs_root *reloc_root; 42463fd0a558SYan, Zheng struct btrfs_root *new_root; 42473fd0a558SYan, Zheng struct reloc_control *rc; 42483fd0a558SYan, Zheng int ret; 42493fd0a558SYan, Zheng 42503fd0a558SYan, Zheng if (!root->reloc_root) 42513fd0a558SYan, Zheng return; 42523fd0a558SYan, Zheng 42533fd0a558SYan, Zheng rc = root->fs_info->reloc_ctl; 42543fd0a558SYan, Zheng rc->merging_rsv_size += rc->nodes_relocated; 42553fd0a558SYan, Zheng 42563fd0a558SYan, Zheng if (rc->merge_reloc_tree) { 42573fd0a558SYan, Zheng ret = btrfs_block_rsv_migrate(&pending->block_rsv, 42583fd0a558SYan, Zheng rc->block_rsv, 42593fd0a558SYan, Zheng rc->nodes_relocated); 42603fd0a558SYan, Zheng BUG_ON(ret); 42613fd0a558SYan, Zheng } 42623fd0a558SYan, Zheng 42633fd0a558SYan, Zheng new_root = pending->snap; 42643fd0a558SYan, Zheng reloc_root = create_reloc_root(trans, root->reloc_root, 42653fd0a558SYan, Zheng new_root->root_key.objectid); 42663fd0a558SYan, Zheng 42673fd0a558SYan, Zheng __add_reloc_root(reloc_root); 42683fd0a558SYan, Zheng new_root->reloc_root = reloc_root; 42693fd0a558SYan, Zheng 42703fd0a558SYan, Zheng if (rc->create_reloc_tree) { 42713fd0a558SYan, Zheng ret = clone_backref_node(trans, rc, root, reloc_root); 42723fd0a558SYan, Zheng BUG_ON(ret); 42733fd0a558SYan, Zheng } 42743fd0a558SYan, Zheng } 4275