diff options
Diffstat (limited to 'fs/btrfs/relocation.c')
| -rw-r--r-- | fs/btrfs/relocation.c | 4795 |
1 files changed, 2296 insertions, 2499 deletions
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 12096496cc99..5bfefc3e9c06 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -1,19 +1,6 @@ +// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2009 Oracle. All rights reserved. - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public - * License v2 as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU - * General Public License for more details. - * - * You should have received a copy of the GNU General Public - * License along with this program; if not, write to the - * Free Software Foundation, Inc., 59 Temple Place - Suite 330, - * Boston, MA 021110-1307, USA. */ #include <linux/sched.h> @@ -22,6 +9,7 @@ #include <linux/blkdev.h> #include <linux/rbtree.h> #include <linux/slab.h> +#include <linux/error-injection.h> #include "ctree.h" #include "disk-io.h" #include "transaction.h" @@ -30,101 +18,87 @@ #include "btrfs_inode.h" #include "async-thread.h" #include "free-space-cache.h" -#include "inode-map.h" - -/* - * backref_node, mapping_node and tree_block start with this - */ -struct tree_entry { - struct rb_node rb_node; - u64 bytenr; -}; - -/* - * present a tree block in the backref cache - */ -struct backref_node { - struct rb_node rb_node; - u64 bytenr; - - u64 new_bytenr; - /* objectid of tree block owner, can be not uptodate */ - u64 owner; - /* link to pending, changed or detached list */ - struct list_head list; - /* list of upper level blocks reference this block */ - struct list_head upper; - /* list of child blocks in the cache */ - struct list_head lower; - /* NULL if this node is not tree root */ - struct btrfs_root *root; - /* extent buffer got by COW the block */ - struct extent_buffer *eb; - /* level of tree block */ - unsigned int level:8; - /* is the block in non-reference counted tree */ - unsigned int cowonly:1; - /* 1 if no child node in the cache */ - unsigned int lowest:1; - /* is the extent buffer locked */ - unsigned int locked:1; - /* has the block been processed */ - unsigned int processed:1; - /* have backrefs of this block been checked */ - unsigned int checked:1; - /* - * 1 if corresponding block has been cowed but some upper - * level block pointers may not point to the new location - */ - unsigned int pending:1; - /* - * 1 if the backref node isn't connected to any other - * backref node. - */ - unsigned int detached:1; -}; +#include "qgroup.h" +#include "print-tree.h" +#include "delalloc-space.h" +#include "block-group.h" +#include "backref.h" +#include "misc.h" +#include "subpage.h" +#include "zoned.h" +#include "inode-item.h" +#include "space-info.h" +#include "fs.h" +#include "accessors.h" +#include "extent-tree.h" +#include "root-tree.h" +#include "file-item.h" +#include "relocation.h" +#include "super.h" +#include "tree-checker.h" +#include "raid-stripe-tree.h" /* - * present a block pointer in the backref cache + * Relocation overview + * + * [What does relocation do] + * + * The objective of relocation is to relocate all extents of the target block + * group to other block groups. + * This is utilized by resize (shrink only), profile converting, compacting + * space, or balance routine to spread chunks over devices. + * + * Before | After + * ------------------------------------------------------------------ + * BG A: 10 data extents | BG A: deleted + * BG B: 2 data extents | BG B: 10 data extents (2 old + 8 relocated) + * BG C: 1 extents | BG C: 3 data extents (1 old + 2 relocated) + * + * [How does relocation work] + * + * 1. Mark the target block group read-only + * New extents won't be allocated from the target block group. + * + * 2.1 Record each extent in the target block group + * To build a proper map of extents to be relocated. + * + * 2.2 Build data reloc tree and reloc trees + * Data reloc tree will contain an inode, recording all newly relocated + * data extents. + * There will be only one data reloc tree for one data block group. + * + * Reloc tree will be a special snapshot of its source tree, containing + * relocated tree blocks. + * Each tree referring to a tree block in target block group will get its + * reloc tree built. + * + * 2.3 Swap source tree with its corresponding reloc tree + * Each involved tree only refers to new extents after swap. + * + * 3. Cleanup reloc trees and data reloc tree. + * As old extents in the target block group are still referenced by reloc + * trees, we need to clean them up before really freeing the target block + * group. + * + * The main complexity is in steps 2.2 and 2.3. + * + * The entry point of relocation is relocate_block_group() function. */ -struct backref_edge { - struct list_head list[2]; - struct backref_node *node[2]; -}; - -#define LOWER 0 -#define UPPER 1 - -struct backref_cache { - /* red black tree of all backref nodes in the cache */ - struct rb_root rb_root; - /* for passing backref nodes to btrfs_reloc_cow_block */ - struct backref_node *path[BTRFS_MAX_LEVEL]; - /* - * list of blocks that have been cowed but some block - * pointers in upper level blocks may not reflect the - * new location - */ - struct list_head pending[BTRFS_MAX_LEVEL]; - /* list of backref nodes with no child node */ - struct list_head leaves; - /* list of blocks that have been cowed in current transaction */ - struct list_head changed; - /* list of detached backref node. */ - struct list_head detached; - - u64 last_trans; - - int nr_nodes; - int nr_edges; -}; +#define RELOCATION_RESERVED_NODES 256 /* * map address of tree root to tree */ struct mapping_node { - struct rb_node rb_node; - u64 bytenr; + union { + /* Use rb_simple_node for search/insert */ + struct { + struct rb_node rb_node; + u64 bytenr; + }; + + struct rb_simple_node simple_node; + }; void *data; }; @@ -137,11 +111,19 @@ struct mapping_tree { * present a tree block to process */ struct tree_block { - struct rb_node rb_node; - u64 bytenr; + union { + /* Use rb_simple_node for search/insert */ + struct { + struct rb_node rb_node; + u64 bytenr; + }; + + struct rb_simple_node simple_node; + }; + u64 owner; struct btrfs_key key; - unsigned int level:8; - unsigned int key_ready:1; + u8 level; + bool key_ready; }; #define MAX_EXTENTS 128 @@ -151,11 +133,18 @@ struct file_extent_cluster { u64 end; u64 boundary[MAX_EXTENTS]; unsigned int nr; + u64 owning_root; +}; + +/* Stages of data relocation. */ +enum reloc_stage { + MOVE_DATA_EXTENTS, + UPDATE_DATA_PTRS }; struct reloc_control { /* block group to relocate */ - struct btrfs_block_group_cache *block_group; + struct btrfs_block_group *block_group; /* extent tree */ struct btrfs_root *extent_root; /* inode for moving data */ @@ -163,7 +152,7 @@ struct reloc_control { struct btrfs_block_rsv *block_rsv; - struct backref_cache backref_cache; + struct btrfs_backref_cache backref_cache; struct file_extent_cluster cluster; /* tree blocks have been processed */ @@ -172,185 +161,53 @@ struct reloc_control { struct mapping_tree reloc_root_tree; /* list of reloc trees */ struct list_head reloc_roots; + /* list of subvolume trees that get relocated */ + struct list_head dirty_subvol_roots; /* size of metadata reservation for merging reloc trees */ u64 merging_rsv_size; /* size of relocated tree nodes */ u64 nodes_relocated; + /* reserved size for block group relocation*/ + u64 reserved_bytes; u64 search_start; u64 extents_found; - unsigned int stage:8; - unsigned int create_reloc_tree:1; - unsigned int merge_reloc_tree:1; - unsigned int found_file_extent:1; - unsigned int commit_transaction:1; + enum reloc_stage stage; + bool create_reloc_tree; + bool merge_reloc_tree; + bool found_file_extent; }; -/* stages of data relocation */ -#define MOVE_DATA_EXTENTS 0 -#define UPDATE_DATA_PTRS 1 - -static void remove_backref_node(struct backref_cache *cache, - struct backref_node *node); -static void __mark_block_processed(struct reloc_control *rc, - struct backref_node *node); - -static void mapping_tree_init(struct mapping_tree *tree) -{ - tree->rb_root = RB_ROOT; - spin_lock_init(&tree->lock); -} - -static void backref_cache_init(struct backref_cache *cache) -{ - int i; - cache->rb_root = RB_ROOT; - for (i = 0; i < BTRFS_MAX_LEVEL; i++) - INIT_LIST_HEAD(&cache->pending[i]); - INIT_LIST_HEAD(&cache->changed); - INIT_LIST_HEAD(&cache->detached); - INIT_LIST_HEAD(&cache->leaves); -} - -static void backref_cache_cleanup(struct backref_cache *cache) -{ - struct backref_node *node; - int i; - - while (!list_empty(&cache->detached)) { - node = list_entry(cache->detached.next, - struct backref_node, list); - remove_backref_node(cache, node); - } - - while (!list_empty(&cache->leaves)) { - node = list_entry(cache->leaves.next, - struct backref_node, lower); - remove_backref_node(cache, node); - } - - cache->last_trans = 0; - - for (i = 0; i < BTRFS_MAX_LEVEL; i++) - BUG_ON(!list_empty(&cache->pending[i])); - BUG_ON(!list_empty(&cache->changed)); - BUG_ON(!list_empty(&cache->detached)); - BUG_ON(!RB_EMPTY_ROOT(&cache->rb_root)); - BUG_ON(cache->nr_nodes); - BUG_ON(cache->nr_edges); -} - -static struct backref_node *alloc_backref_node(struct backref_cache *cache) -{ - struct backref_node *node; - - node = kzalloc(sizeof(*node), GFP_NOFS); - if (node) { - INIT_LIST_HEAD(&node->list); - INIT_LIST_HEAD(&node->upper); - INIT_LIST_HEAD(&node->lower); - RB_CLEAR_NODE(&node->rb_node); - cache->nr_nodes++; - } - return node; -} - -static void free_backref_node(struct backref_cache *cache, - struct backref_node *node) -{ - if (node) { - cache->nr_nodes--; - kfree(node); - } -} - -static struct backref_edge *alloc_backref_edge(struct backref_cache *cache) -{ - struct backref_edge *edge; - - edge = kzalloc(sizeof(*edge), GFP_NOFS); - if (edge) - cache->nr_edges++; - return edge; -} - -static void free_backref_edge(struct backref_cache *cache, - struct backref_edge *edge) -{ - if (edge) { - cache->nr_edges--; - kfree(edge); - } -} - -static struct rb_node *tree_insert(struct rb_root *root, u64 bytenr, - struct rb_node *node) -{ - struct rb_node **p = &root->rb_node; - struct rb_node *parent = NULL; - struct tree_entry *entry; - - while (*p) { - parent = *p; - entry = rb_entry(parent, struct tree_entry, rb_node); - - if (bytenr < entry->bytenr) - p = &(*p)->rb_left; - else if (bytenr > entry->bytenr) - p = &(*p)->rb_right; - else - return parent; - } - - rb_link_node(node, parent, p); - rb_insert_color(node, root); - return NULL; -} - -static struct rb_node *tree_search(struct rb_root *root, u64 bytenr) +static void mark_block_processed(struct reloc_control *rc, + struct btrfs_backref_node *node) { - struct rb_node *n = root->rb_node; - struct tree_entry *entry; - - while (n) { - entry = rb_entry(n, struct tree_entry, rb_node); + u32 blocksize; - if (bytenr < entry->bytenr) - n = n->rb_left; - else if (bytenr > entry->bytenr) - n = n->rb_right; - else - return n; + if (node->level == 0 || + in_range(node->bytenr, rc->block_group->start, + rc->block_group->length)) { + blocksize = rc->extent_root->fs_info->nodesize; + btrfs_set_extent_bit(&rc->processed_blocks, node->bytenr, + node->bytenr + blocksize - 1, EXTENT_DIRTY, + NULL); } - return NULL; -} - -static void backref_tree_panic(struct rb_node *rb_node, int errno, u64 bytenr) -{ - - struct btrfs_fs_info *fs_info = NULL; - struct backref_node *bnode = rb_entry(rb_node, struct backref_node, - rb_node); - if (bnode->root) - fs_info = bnode->root->fs_info; - btrfs_panic(fs_info, errno, "Inconsistency in backref cache " - "found at offset %llu\n", (unsigned long long)bytenr); + node->processed = 1; } /* * walk up backref nodes until reach node presents tree root */ -static struct backref_node *walk_up_backref(struct backref_node *node, - struct backref_edge *edges[], - int *index) +static struct btrfs_backref_node *walk_up_backref( + struct btrfs_backref_node *node, + struct btrfs_backref_edge *edges[], int *index) { - struct backref_edge *edge; + struct btrfs_backref_edge *edge; int idx = *index; while (!list_empty(&node->upper)) { - edge = list_entry(node->upper.next, - struct backref_edge, list[LOWER]); + edge = list_first_entry(&node->upper, struct btrfs_backref_edge, + list[LOWER]); edges[idx++] = edge; node = edge->node[UPPER]; } @@ -362,11 +219,11 @@ static struct backref_node *walk_up_backref(struct backref_node *node, /* * walk down backref nodes to find start of next reference path */ -static struct backref_node *walk_down_backref(struct backref_edge *edges[], - int *index) +static struct btrfs_backref_node *walk_down_backref( + struct btrfs_backref_edge *edges[], int *index) { - struct backref_edge *edge; - struct backref_node *lower; + struct btrfs_backref_edge *edge; + struct btrfs_backref_node *lower; int idx = *index; while (idx > 0) { @@ -376,8 +233,8 @@ static struct backref_node *walk_down_backref(struct backref_edge *edges[], idx--; continue; } - edge = list_entry(edge->list[LOWER].next, - struct backref_edge, list[LOWER]); + edge = list_first_entry(&edge->list[LOWER], struct btrfs_backref_edge, + list[LOWER]); edges[idx - 1] = edge; *index = idx; return edge->node[UPPER]; @@ -386,871 +243,259 @@ static struct backref_node *walk_down_backref(struct backref_edge *edges[], return NULL; } -static void unlock_node_buffer(struct backref_node *node) -{ - if (node->locked) { - btrfs_tree_unlock(node->eb); - node->locked = 0; - } -} - -static void drop_node_buffer(struct backref_node *node) +static bool reloc_root_is_dead(const struct btrfs_root *root) { - if (node->eb) { - unlock_node_buffer(node); - free_extent_buffer(node->eb); - node->eb = NULL; - } -} - -static void drop_backref_node(struct backref_cache *tree, - struct backref_node *node) -{ - BUG_ON(!list_empty(&node->upper)); - - drop_node_buffer(node); - list_del(&node->list); - list_del(&node->lower); - if (!RB_EMPTY_NODE(&node->rb_node)) - rb_erase(&node->rb_node, &tree->rb_root); - free_backref_node(tree, node); -} - -/* - * remove a backref node from the backref cache - */ -static void remove_backref_node(struct backref_cache *cache, - struct backref_node *node) -{ - struct backref_node *upper; - struct backref_edge *edge; - - if (!node) - return; - - BUG_ON(!node->lowest && !node->detached); - while (!list_empty(&node->upper)) { - edge = list_entry(node->upper.next, struct backref_edge, - list[LOWER]); - upper = edge->node[UPPER]; - list_del(&edge->list[LOWER]); - list_del(&edge->list[UPPER]); - free_backref_edge(cache, edge); - - if (RB_EMPTY_NODE(&upper->rb_node)) { - BUG_ON(!list_empty(&node->upper)); - drop_backref_node(cache, node); - node = upper; - node->lowest = 1; - continue; - } - /* - * add the node to leaf node list if no other - * child block cached. - */ - if (list_empty(&upper->lower)) { - list_add_tail(&upper->lower, &cache->leaves); - upper->lowest = 1; - } - } - - drop_backref_node(cache, node); -} - -static void update_backref_node(struct backref_cache *cache, - struct backref_node *node, u64 bytenr) -{ - struct rb_node *rb_node; - rb_erase(&node->rb_node, &cache->rb_root); - node->bytenr = bytenr; - rb_node = tree_insert(&cache->rb_root, node->bytenr, &node->rb_node); - if (rb_node) - backref_tree_panic(rb_node, -EEXIST, bytenr); + /* + * Pair with set_bit/clear_bit in clean_dirty_subvols and + * btrfs_update_reloc_root. We need to see the updated bit before + * trying to access reloc_root + */ + smp_rmb(); + if (test_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state)) + return true; + return false; } /* - * update backref cache after a transaction commit + * Check if this subvolume tree has valid reloc tree. + * + * Reloc tree after swap is considered dead, thus not considered as valid. + * This is enough for most callers, as they don't distinguish dead reloc root + * from no reloc root. But btrfs_should_ignore_reloc_root() below is a + * special case. */ -static int update_backref_cache(struct btrfs_trans_handle *trans, - struct backref_cache *cache) +static bool have_reloc_root(const struct btrfs_root *root) { - struct backref_node *node; - int level = 0; - - if (cache->last_trans == 0) { - cache->last_trans = trans->transid; - return 0; - } - - if (cache->last_trans == trans->transid) - return 0; - - /* - * detached nodes are used to avoid unnecessary backref - * lookup. transaction commit changes the extent tree. - * so the detached nodes are no longer useful. - */ - while (!list_empty(&cache->detached)) { - node = list_entry(cache->detached.next, - struct backref_node, list); - remove_backref_node(cache, node); - } - - while (!list_empty(&cache->changed)) { - node = list_entry(cache->changed.next, - struct backref_node, list); - list_del_init(&node->list); - BUG_ON(node->pending); - update_backref_node(cache, node, node->new_bytenr); - } - - /* - * some nodes can be left in the pending list if there were - * errors during processing the pending nodes. - */ - for (level = 0; level < BTRFS_MAX_LEVEL; level++) { - list_for_each_entry(node, &cache->pending[level], list) { - BUG_ON(!node->pending); - if (node->bytenr == node->new_bytenr) - continue; - update_backref_node(cache, node, node->new_bytenr); - } - } - - cache->last_trans = 0; - return 1; + if (reloc_root_is_dead(root)) + return false; + if (!root->reloc_root) + return false; + return true; } - -static int should_ignore_root(struct btrfs_root *root) +bool btrfs_should_ignore_reloc_root(const struct btrfs_root *root) { struct btrfs_root *reloc_root; - if (!root->ref_cows) - return 0; + if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) + return false; + + /* This root has been merged with its reloc tree, we can ignore it */ + if (reloc_root_is_dead(root)) + return true; reloc_root = root->reloc_root; if (!reloc_root) - return 0; + return false; - if (btrfs_root_last_snapshot(&reloc_root->root_item) == - root->fs_info->running_transaction->transid - 1) - return 0; + if (btrfs_header_generation(reloc_root->commit_root) == + root->fs_info->running_transaction->transid) + return false; /* - * if there is reloc tree and it was created in previous - * transaction backref lookup can find the reloc tree, - * so backref node for the fs tree root is useless for - * relocation. + * If there is reloc tree and it was created in previous transaction + * backref lookup can find the reloc tree, so backref node for the fs + * tree root is useless for relocation. */ - return 1; + return true; } + /* * find reloc tree by address of tree root */ -static struct btrfs_root *find_reloc_root(struct reloc_control *rc, - u64 bytenr) +struct btrfs_root *find_reloc_root(struct btrfs_fs_info *fs_info, u64 bytenr) { + struct reloc_control *rc = fs_info->reloc_ctl; struct rb_node *rb_node; struct mapping_node *node; struct btrfs_root *root = NULL; + ASSERT(rc); spin_lock(&rc->reloc_root_tree.lock); - rb_node = tree_search(&rc->reloc_root_tree.rb_root, bytenr); + rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root, bytenr); if (rb_node) { node = rb_entry(rb_node, struct mapping_node, rb_node); - root = (struct btrfs_root *)node->data; + root = node->data; } spin_unlock(&rc->reloc_root_tree.lock); - return root; -} - -static int is_cowonly_root(u64 root_objectid) -{ - if (root_objectid == BTRFS_ROOT_TREE_OBJECTID || - root_objectid == BTRFS_EXTENT_TREE_OBJECTID || - root_objectid == BTRFS_CHUNK_TREE_OBJECTID || - root_objectid == BTRFS_DEV_TREE_OBJECTID || - root_objectid == BTRFS_TREE_LOG_OBJECTID || - root_objectid == BTRFS_CSUM_TREE_OBJECTID) - return 1; - return 0; + return btrfs_grab_root(root); } -static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, - u64 root_objectid) -{ - struct btrfs_key key; - - key.objectid = root_objectid; - key.type = BTRFS_ROOT_ITEM_KEY; - if (is_cowonly_root(root_objectid)) - key.offset = 0; - else - key.offset = (u64)-1; - - return btrfs_read_fs_root_no_name(fs_info, &key); -} - -#ifdef BTRFS_COMPAT_EXTENT_TREE_V0 -static noinline_for_stack -struct btrfs_root *find_tree_root(struct reloc_control *rc, - struct extent_buffer *leaf, - struct btrfs_extent_ref_v0 *ref0) +/* + * For useless nodes, do two major clean ups: + * + * - Cleanup the children edges and nodes + * If child node is also orphan (no parent) during cleanup, then the child + * node will also be cleaned up. + * + * - Freeing up leaves (level 0), keeps nodes detached + * For nodes, the node is still cached as "detached" + * + * Return false if @node is not in the @useless_nodes list. + * Return true if @node is in the @useless_nodes list. + */ +static bool handle_useless_nodes(struct reloc_control *rc, + struct btrfs_backref_node *node) { - struct btrfs_root *root; - u64 root_objectid = btrfs_ref_root_v0(leaf, ref0); - u64 generation = btrfs_ref_generation_v0(leaf, ref0); + struct btrfs_backref_cache *cache = &rc->backref_cache; + struct list_head *useless_node = &cache->useless_node; + bool ret = false; - BUG_ON(root_objectid == BTRFS_TREE_RELOC_OBJECTID); + while (!list_empty(useless_node)) { + struct btrfs_backref_node *cur; - root = read_fs_root(rc->extent_root->fs_info, root_objectid); - BUG_ON(IS_ERR(root)); + cur = list_first_entry(useless_node, struct btrfs_backref_node, + list); + list_del_init(&cur->list); - if (root->ref_cows && - generation != btrfs_root_generation(&root->root_item)) - return NULL; + /* Only tree root nodes can be added to @useless_nodes */ + ASSERT(list_empty(&cur->upper)); - return root; -} -#endif + if (cur == node) + ret = true; -static noinline_for_stack -int find_inline_backref(struct extent_buffer *leaf, int slot, - unsigned long *ptr, unsigned long *end) -{ - struct btrfs_key key; - struct btrfs_extent_item *ei; - struct btrfs_tree_block_info *bi; - u32 item_size; + /* Cleanup the lower edges */ + while (!list_empty(&cur->lower)) { + struct btrfs_backref_edge *edge; + struct btrfs_backref_node *lower; - btrfs_item_key_to_cpu(leaf, &key, slot); + edge = list_first_entry(&cur->lower, struct btrfs_backref_edge, + list[UPPER]); + list_del(&edge->list[UPPER]); + list_del(&edge->list[LOWER]); + lower = edge->node[LOWER]; + btrfs_backref_free_edge(cache, edge); - item_size = btrfs_item_size_nr(leaf, slot); -#ifdef BTRFS_COMPAT_EXTENT_TREE_V0 - if (item_size < sizeof(*ei)) { - WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0)); - return 1; - } -#endif - ei = btrfs_item_ptr(leaf, slot, struct btrfs_extent_item); - WARN_ON(!(btrfs_extent_flags(leaf, ei) & - BTRFS_EXTENT_FLAG_TREE_BLOCK)); - - if (key.type == BTRFS_EXTENT_ITEM_KEY && - item_size <= sizeof(*ei) + sizeof(*bi)) { - WARN_ON(item_size < sizeof(*ei) + sizeof(*bi)); - return 1; - } + /* Child node is also orphan, queue for cleanup */ + if (list_empty(&lower->upper)) + list_add(&lower->list, useless_node); + } + /* Mark this block processed for relocation */ + mark_block_processed(rc, cur); - if (key.type == BTRFS_EXTENT_ITEM_KEY) { - bi = (struct btrfs_tree_block_info *)(ei + 1); - *ptr = (unsigned long)(bi + 1); - } else { - *ptr = (unsigned long)(ei + 1); + /* + * Backref nodes for tree leaves are deleted from the cache. + * Backref nodes for upper level tree blocks are left in the + * cache to avoid unnecessary backref lookup. + */ + if (cur->level > 0) { + cur->detached = 1; + } else { + rb_erase(&cur->rb_node, &cache->rb_root); + btrfs_backref_free_node(cache, cur); + } } - *end = (unsigned long)ei + item_size; - return 0; + return ret; } /* - * build backref tree for a given tree block. root of the backref tree - * corresponds the tree block, leaves of the backref tree correspond - * roots of b-trees that reference the tree block. + * Build backref tree for a given tree block. Root of the backref tree + * corresponds the tree block, leaves of the backref tree correspond roots of + * b-trees that reference the tree block. * - * the basic idea of this function is check backrefs of a given block - * to find upper level blocks that refernece the block, and then check - * bakcrefs of these upper level blocks recursively. the recursion stop - * when tree root is reached or backrefs for the block is cached. + * The basic idea of this function is check backrefs of a given block to find + * upper level blocks that reference the block, and then check backrefs of + * these upper level blocks recursively. The recursion stops when tree root is + * reached or backrefs for the block is cached. * - * NOTE: if we find backrefs for a block are cached, we know backrefs - * for all upper level blocks that directly/indirectly reference the - * block are also cached. + * NOTE: if we find that backrefs for a block are cached, we know backrefs for + * all upper level blocks that directly/indirectly reference the block are also + * cached. */ -static noinline_for_stack -struct backref_node *build_backref_tree(struct reloc_control *rc, - struct btrfs_key *node_key, - int level, u64 bytenr) +static noinline_for_stack struct btrfs_backref_node *build_backref_tree( + struct btrfs_trans_handle *trans, + struct reloc_control *rc, struct btrfs_key *node_key, + int level, u64 bytenr) { - struct backref_cache *cache = &rc->backref_cache; - struct btrfs_path *path1; - struct btrfs_path *path2; - struct extent_buffer *eb; - struct btrfs_root *root; - struct backref_node *cur; - struct backref_node *upper; - struct backref_node *lower; - struct backref_node *node = NULL; - struct backref_node *exist = NULL; - struct backref_edge *edge; - struct rb_node *rb_node; - struct btrfs_key key; - unsigned long end; - unsigned long ptr; - LIST_HEAD(list); - LIST_HEAD(useless); - int cowonly; + struct btrfs_backref_iter *iter; + struct btrfs_backref_cache *cache = &rc->backref_cache; + /* For searching parent of TREE_BLOCK_REF */ + struct btrfs_path *path; + struct btrfs_backref_node *cur; + struct btrfs_backref_node *node = NULL; + struct btrfs_backref_edge *edge; int ret; - int err = 0; - path1 = btrfs_alloc_path(); - path2 = btrfs_alloc_path(); - if (!path1 || !path2) { - err = -ENOMEM; + iter = btrfs_backref_iter_alloc(rc->extent_root->fs_info); + if (!iter) + return ERR_PTR(-ENOMEM); + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; goto out; } - path1->reada = 1; - path2->reada = 2; - node = alloc_backref_node(cache); + node = btrfs_backref_alloc_node(cache, bytenr, level); if (!node) { - err = -ENOMEM; + ret = -ENOMEM; goto out; } - node->bytenr = bytenr; - node->level = level; - node->lowest = 1; cur = node; -again: - end = 0; - ptr = 0; - key.objectid = cur->bytenr; - key.type = BTRFS_METADATA_ITEM_KEY; - key.offset = (u64)-1; - - path1->search_commit_root = 1; - path1->skip_locking = 1; - ret = btrfs_search_slot(NULL, rc->extent_root, &key, path1, - 0, 0); - if (ret < 0) { - err = ret; - goto out; - } - BUG_ON(!ret || !path1->slots[0]); - - path1->slots[0]--; - - WARN_ON(cur->checked); - if (!list_empty(&cur->upper)) { - /* - * the backref was added previously when processing - * backref of type BTRFS_TREE_BLOCK_REF_KEY - */ - BUG_ON(!list_is_singular(&cur->upper)); - edge = list_entry(cur->upper.next, struct backref_edge, - list[LOWER]); - BUG_ON(!list_empty(&edge->list[UPPER])); - exist = edge->node[UPPER]; - /* - * add the upper level block to pending list if we need - * check its backrefs - */ - if (!exist->checked) - list_add_tail(&edge->list[UPPER], &list); - } else { - exist = NULL; - } - - while (1) { - cond_resched(); - eb = path1->nodes[0]; - - if (ptr >= end) { - if (path1->slots[0] >= btrfs_header_nritems(eb)) { - ret = btrfs_next_leaf(rc->extent_root, path1); - if (ret < 0) { - err = ret; - goto out; - } - if (ret > 0) - break; - eb = path1->nodes[0]; - } - - btrfs_item_key_to_cpu(eb, &key, path1->slots[0]); - if (key.objectid != cur->bytenr) { - WARN_ON(exist); - break; - } - - if (key.type == BTRFS_EXTENT_ITEM_KEY || - key.type == BTRFS_METADATA_ITEM_KEY) { - ret = find_inline_backref(eb, path1->slots[0], - &ptr, &end); - if (ret) - goto next; - } - } - - if (ptr < end) { - /* update key for inline back ref */ - struct btrfs_extent_inline_ref *iref; - iref = (struct btrfs_extent_inline_ref *)ptr; - key.type = btrfs_extent_inline_ref_type(eb, iref); - key.offset = btrfs_extent_inline_ref_offset(eb, iref); - WARN_ON(key.type != BTRFS_TREE_BLOCK_REF_KEY && - key.type != BTRFS_SHARED_BLOCK_REF_KEY); - } - - if (exist && - ((key.type == BTRFS_TREE_BLOCK_REF_KEY && - exist->owner == key.offset) || - (key.type == BTRFS_SHARED_BLOCK_REF_KEY && - exist->bytenr == key.offset))) { - exist = NULL; - goto next; - } - -#ifdef BTRFS_COMPAT_EXTENT_TREE_V0 - if (key.type == BTRFS_SHARED_BLOCK_REF_KEY || - key.type == BTRFS_EXTENT_REF_V0_KEY) { - if (key.type == BTRFS_EXTENT_REF_V0_KEY) { - struct btrfs_extent_ref_v0 *ref0; - ref0 = btrfs_item_ptr(eb, path1->slots[0], - struct btrfs_extent_ref_v0); - if (key.objectid == key.offset) { - root = find_tree_root(rc, eb, ref0); - if (root && !should_ignore_root(root)) - cur->root = root; - else - list_add(&cur->list, &useless); - break; - } - if (is_cowonly_root(btrfs_ref_root_v0(eb, - ref0))) - cur->cowonly = 1; - } -#else - BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY); - if (key.type == BTRFS_SHARED_BLOCK_REF_KEY) { -#endif - if (key.objectid == key.offset) { - /* - * only root blocks of reloc trees use - * backref of this type. - */ - root = find_reloc_root(rc, cur->bytenr); - BUG_ON(!root); - cur->root = root; - break; - } - - edge = alloc_backref_edge(cache); - if (!edge) { - err = -ENOMEM; - goto out; - } - rb_node = tree_search(&cache->rb_root, key.offset); - if (!rb_node) { - upper = alloc_backref_node(cache); - if (!upper) { - free_backref_edge(cache, edge); - err = -ENOMEM; - goto out; - } - upper->bytenr = key.offset; - upper->level = cur->level + 1; - /* - * backrefs for the upper level block isn't - * cached, add the block to pending list - */ - list_add_tail(&edge->list[UPPER], &list); - } else { - upper = rb_entry(rb_node, struct backref_node, - rb_node); - BUG_ON(!upper->checked); - INIT_LIST_HEAD(&edge->list[UPPER]); - } - list_add_tail(&edge->list[LOWER], &cur->upper); - edge->node[LOWER] = cur; - edge->node[UPPER] = upper; - - goto next; - } else if (key.type != BTRFS_TREE_BLOCK_REF_KEY) { - goto next; - } - /* key.type == BTRFS_TREE_BLOCK_REF_KEY */ - root = read_fs_root(rc->extent_root->fs_info, key.offset); - if (IS_ERR(root)) { - err = PTR_ERR(root); + /* Breadth-first search to build backref cache */ + do { + ret = btrfs_backref_add_tree_node(trans, cache, path, iter, + node_key, cur); + if (ret < 0) goto out; - } - - if (!root->ref_cows) - cur->cowonly = 1; - - if (btrfs_root_level(&root->root_item) == cur->level) { - /* tree root */ - BUG_ON(btrfs_root_bytenr(&root->root_item) != - cur->bytenr); - if (should_ignore_root(root)) - list_add(&cur->list, &useless); - else - cur->root = root; - break; - } - - level = cur->level + 1; + edge = list_first_entry_or_null(&cache->pending_edge, + struct btrfs_backref_edge, list[UPPER]); /* - * searching the tree to find upper level blocks - * reference the block. + * The pending list isn't empty, take the first block to + * process */ - path2->search_commit_root = 1; - path2->skip_locking = 1; - path2->lowest_level = level; - ret = btrfs_search_slot(NULL, root, node_key, path2, 0, 0); - path2->lowest_level = 0; - if (ret < 0) { - err = ret; - goto out; + if (edge) { + list_del_init(&edge->list[UPPER]); + cur = edge->node[UPPER]; } - if (ret > 0 && path2->slots[level] > 0) - path2->slots[level]--; - - eb = path2->nodes[level]; - WARN_ON(btrfs_node_blockptr(eb, path2->slots[level]) != - cur->bytenr); - - lower = cur; - for (; level < BTRFS_MAX_LEVEL; level++) { - if (!path2->nodes[level]) { - BUG_ON(btrfs_root_bytenr(&root->root_item) != - lower->bytenr); - if (should_ignore_root(root)) - list_add(&lower->list, &useless); - else - lower->root = root; - break; - } - - edge = alloc_backref_edge(cache); - if (!edge) { - err = -ENOMEM; - goto out; - } + } while (edge); - eb = path2->nodes[level]; - rb_node = tree_search(&cache->rb_root, eb->start); - if (!rb_node) { - upper = alloc_backref_node(cache); - if (!upper) { - free_backref_edge(cache, edge); - err = -ENOMEM; - goto out; - } - upper->bytenr = eb->start; - upper->owner = btrfs_header_owner(eb); - upper->level = lower->level + 1; - if (!root->ref_cows) - upper->cowonly = 1; - - /* - * if we know the block isn't shared - * we can void checking its backrefs. - */ - if (btrfs_block_can_be_shared(root, eb)) - upper->checked = 0; - else - upper->checked = 1; - - /* - * add the block to pending list if we - * need check its backrefs. only block - * at 'cur->level + 1' is added to the - * tail of pending list. this guarantees - * we check backrefs from lower level - * blocks to upper level blocks. - */ - if (!upper->checked && - level == cur->level + 1) { - list_add_tail(&edge->list[UPPER], - &list); - } else - INIT_LIST_HEAD(&edge->list[UPPER]); - } else { - upper = rb_entry(rb_node, struct backref_node, - rb_node); - BUG_ON(!upper->checked); - INIT_LIST_HEAD(&edge->list[UPPER]); - if (!upper->owner) - upper->owner = btrfs_header_owner(eb); - } - list_add_tail(&edge->list[LOWER], &lower->upper); - edge->node[LOWER] = lower; - edge->node[UPPER] = upper; - - if (rb_node) - break; - lower = upper; - upper = NULL; - } - btrfs_release_path(path2); -next: - if (ptr < end) { - ptr += btrfs_extent_inline_ref_size(key.type); - if (ptr >= end) { - WARN_ON(ptr > end); - ptr = 0; - end = 0; - } - } - if (ptr >= end) - path1->slots[0]++; - } - btrfs_release_path(path1); - - cur->checked = 1; - WARN_ON(exist); - - /* the pending list isn't empty, take the first block to process */ - if (!list_empty(&list)) { - edge = list_entry(list.next, struct backref_edge, list[UPPER]); - list_del_init(&edge->list[UPPER]); - cur = edge->node[UPPER]; - goto again; - } - - /* - * everything goes well, connect backref nodes and insert backref nodes - * into the cache. - */ - BUG_ON(!node->checked); - cowonly = node->cowonly; - if (!cowonly) { - rb_node = tree_insert(&cache->rb_root, node->bytenr, - &node->rb_node); - if (rb_node) - backref_tree_panic(rb_node, -EEXIST, node->bytenr); - list_add_tail(&node->lower, &cache->leaves); - } - - list_for_each_entry(edge, &node->upper, list[LOWER]) - list_add_tail(&edge->list[UPPER], &list); - - while (!list_empty(&list)) { - edge = list_entry(list.next, struct backref_edge, list[UPPER]); - list_del_init(&edge->list[UPPER]); - upper = edge->node[UPPER]; - if (upper->detached) { - list_del(&edge->list[LOWER]); - lower = edge->node[LOWER]; - free_backref_edge(cache, edge); - if (list_empty(&lower->upper)) - list_add(&lower->list, &useless); - continue; - } - - if (!RB_EMPTY_NODE(&upper->rb_node)) { - if (upper->lowest) { - list_del_init(&upper->lower); - upper->lowest = 0; - } - - list_add_tail(&edge->list[UPPER], &upper->lower); - continue; - } - - BUG_ON(!upper->checked); - BUG_ON(cowonly != upper->cowonly); - if (!cowonly) { - rb_node = tree_insert(&cache->rb_root, upper->bytenr, - &upper->rb_node); - if (rb_node) - backref_tree_panic(rb_node, -EEXIST, - upper->bytenr); - } - - list_add_tail(&edge->list[UPPER], &upper->lower); - - list_for_each_entry(edge, &upper->upper, list[LOWER]) - list_add_tail(&edge->list[UPPER], &list); - } - /* - * process useless backref nodes. backref nodes for tree leaves - * are deleted from the cache. backref nodes for upper level - * tree blocks are left in the cache to avoid unnecessary backref - * lookup. - */ - while (!list_empty(&useless)) { - upper = list_entry(useless.next, struct backref_node, list); - list_del_init(&upper->list); - BUG_ON(!list_empty(&upper->upper)); - if (upper == node) - node = NULL; - if (upper->lowest) { - list_del_init(&upper->lower); - upper->lowest = 0; - } - while (!list_empty(&upper->lower)) { - edge = list_entry(upper->lower.next, - struct backref_edge, list[UPPER]); - list_del(&edge->list[UPPER]); - list_del(&edge->list[LOWER]); - lower = edge->node[LOWER]; - free_backref_edge(cache, edge); + /* Finish the upper linkage of newly added edges/nodes */ + ret = btrfs_backref_finish_upper_links(cache, node); + if (ret < 0) + goto out; - if (list_empty(&lower->upper)) - list_add(&lower->list, &useless); - } - __mark_block_processed(rc, upper); - if (upper->level > 0) { - list_add(&upper->list, &cache->detached); - upper->detached = 1; - } else { - rb_erase(&upper->rb_node, &cache->rb_root); - free_backref_node(cache, upper); - } - } + if (handle_useless_nodes(rc, node)) + node = NULL; out: - btrfs_free_path(path1); - btrfs_free_path(path2); - if (err) { - while (!list_empty(&useless)) { - lower = list_entry(useless.next, - struct backref_node, upper); - list_del_init(&lower->upper); - } - upper = node; - INIT_LIST_HEAD(&list); - while (upper) { - if (RB_EMPTY_NODE(&upper->rb_node)) { - list_splice_tail(&upper->upper, &list); - free_backref_node(cache, upper); - } - - if (list_empty(&list)) - break; - - edge = list_entry(list.next, struct backref_edge, - list[LOWER]); - list_del(&edge->list[LOWER]); - upper = edge->node[UPPER]; - free_backref_edge(cache, edge); - } - return ERR_PTR(err); + btrfs_free_path(iter->path); + kfree(iter); + btrfs_free_path(path); + if (ret) { + btrfs_backref_error_cleanup(cache, node); + return ERR_PTR(ret); } - BUG_ON(node && node->detached); + ASSERT(!node || !node->detached); + ASSERT(list_empty(&cache->useless_node) && + list_empty(&cache->pending_edge)); return node; } /* - * helper to add backref node for the newly created snapshot. - * the backref node is created by cloning backref node that - * corresponds to root of source tree - */ -static int clone_backref_node(struct btrfs_trans_handle *trans, - struct reloc_control *rc, - struct btrfs_root *src, - struct btrfs_root *dest) -{ - struct btrfs_root *reloc_root = src->reloc_root; - struct backref_cache *cache = &rc->backref_cache; - struct backref_node *node = NULL; - struct backref_node *new_node; - struct backref_edge *edge; - struct backref_edge *new_edge; - struct rb_node *rb_node; - - if (cache->last_trans > 0) - update_backref_cache(trans, cache); - - rb_node = tree_search(&cache->rb_root, src->commit_root->start); - if (rb_node) { - node = rb_entry(rb_node, struct backref_node, rb_node); - if (node->detached) - node = NULL; - else - BUG_ON(node->new_bytenr != reloc_root->node->start); - } - - if (!node) { - rb_node = tree_search(&cache->rb_root, - reloc_root->commit_root->start); - if (rb_node) { - node = rb_entry(rb_node, struct backref_node, - rb_node); - BUG_ON(node->detached); - } - } - - if (!node) - return 0; - - new_node = alloc_backref_node(cache); - if (!new_node) - return -ENOMEM; - - new_node->bytenr = dest->node->start; - new_node->level = node->level; - new_node->lowest = node->lowest; - new_node->checked = 1; - new_node->root = dest; - - if (!node->lowest) { - list_for_each_entry(edge, &node->lower, list[UPPER]) { - new_edge = alloc_backref_edge(cache); - if (!new_edge) - goto fail; - - new_edge->node[UPPER] = new_node; - new_edge->node[LOWER] = edge->node[LOWER]; - list_add_tail(&new_edge->list[UPPER], - &new_node->lower); - } - } else { - list_add_tail(&new_node->lower, &cache->leaves); - } - - rb_node = tree_insert(&cache->rb_root, new_node->bytenr, - &new_node->rb_node); - if (rb_node) - backref_tree_panic(rb_node, -EEXIST, new_node->bytenr); - - if (!new_node->lowest) { - list_for_each_entry(new_edge, &new_node->lower, list[UPPER]) { - list_add_tail(&new_edge->list[LOWER], - &new_edge->node[LOWER]->upper); - } - } - return 0; -fail: - while (!list_empty(&new_node->lower)) { - new_edge = list_entry(new_node->lower.next, - struct backref_edge, list[UPPER]); - list_del(&new_edge->list[UPPER]); - free_backref_edge(cache, new_edge); - } - free_backref_node(cache, new_node); - return -ENOMEM; -} - -/* * helper to add 'address of tree root -> reloc tree' mapping */ -static int __must_check __add_reloc_root(struct btrfs_root *root) +static int __add_reloc_root(struct btrfs_root *root) { + struct btrfs_fs_info *fs_info = root->fs_info; struct rb_node *rb_node; struct mapping_node *node; - struct reloc_control *rc = root->fs_info->reloc_ctl; + struct reloc_control *rc = fs_info->reloc_ctl; node = kmalloc(sizeof(*node), GFP_NOFS); if (!node) return -ENOMEM; - node->bytenr = root->node->start; + node->bytenr = root->commit_root->start; node->data = root; spin_lock(&rc->reloc_root_tree.lock); - rb_node = tree_insert(&rc->reloc_root_tree.rb_root, - node->bytenr, &node->rb_node); + rb_node = rb_simple_insert(&rc->reloc_root_tree.rb_root, &node->simple_node); spin_unlock(&rc->reloc_root_tree.lock); if (rb_node) { - btrfs_panic(root->fs_info, -EEXIST, "Duplicate root found " - "for start=%llu while inserting into relocation " - "tree\n", node->bytenr); - kfree(node); + btrfs_err(fs_info, + "Duplicate root found for start=%llu while inserting into relocation tree", + node->bytenr); return -EEXIST; } @@ -1259,18 +504,62 @@ static int __must_check __add_reloc_root(struct btrfs_root *root) } /* - * helper to update/delete the 'address of tree root -> reloc tree' + * helper to delete the 'address of tree root -> reloc tree' * mapping */ -static int __update_reloc_root(struct btrfs_root *root, int del) +static void __del_reloc_root(struct btrfs_root *root) { + struct btrfs_fs_info *fs_info = root->fs_info; + struct rb_node *rb_node; + struct mapping_node AUTO_KFREE(node); + struct reloc_control *rc = fs_info->reloc_ctl; + bool put_ref = false; + + if (rc && root->node) { + spin_lock(&rc->reloc_root_tree.lock); + rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root, + root->commit_root->start); + if (rb_node) { + node = rb_entry(rb_node, struct mapping_node, rb_node); + rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root); + RB_CLEAR_NODE(&node->rb_node); + } + spin_unlock(&rc->reloc_root_tree.lock); + ASSERT(!node || (struct btrfs_root *)node->data == root); + } + + /* + * We only put the reloc root here if it's on the list. There's a lot + * of places where the pattern is to splice the rc->reloc_roots, process + * the reloc roots, and then add the reloc root back onto + * rc->reloc_roots. If we call __del_reloc_root while it's off of the + * list we don't want the reference being dropped, because the guy + * messing with the list is in charge of the reference. + */ + spin_lock(&fs_info->trans_lock); + if (!list_empty(&root->root_list)) { + put_ref = true; + list_del_init(&root->root_list); + } + spin_unlock(&fs_info->trans_lock); + if (put_ref) + btrfs_put_root(root); +} + +/* + * helper to update the 'address of tree root -> reloc tree' + * mapping + */ +static int __update_reloc_root(struct btrfs_root *root) +{ + struct btrfs_fs_info *fs_info = root->fs_info; struct rb_node *rb_node; struct mapping_node *node = NULL; - struct reloc_control *rc = root->fs_info->reloc_ctl; + struct reloc_control *rc = fs_info->reloc_ctl; spin_lock(&rc->reloc_root_tree.lock); - rb_node = tree_search(&rc->reloc_root_tree.rb_root, - root->commit_root->start); + rb_node = rb_simple_search(&rc->reloc_root_tree.rb_root, + root->commit_root->start); if (rb_node) { node = rb_entry(rb_node, struct mapping_node, rb_node); rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root); @@ -1281,49 +570,70 @@ static int __update_reloc_root(struct btrfs_root *root, int del) return 0; BUG_ON((struct btrfs_root *)node->data != root); - if (!del) { - spin_lock(&rc->reloc_root_tree.lock); - node->bytenr = root->node->start; - rb_node = tree_insert(&rc->reloc_root_tree.rb_root, - node->bytenr, &node->rb_node); - spin_unlock(&rc->reloc_root_tree.lock); - if (rb_node) - backref_tree_panic(rb_node, -EEXIST, node->bytenr); - } else { - spin_lock(&root->fs_info->trans_lock); - list_del_init(&root->root_list); - spin_unlock(&root->fs_info->trans_lock); - kfree(node); - } + spin_lock(&rc->reloc_root_tree.lock); + node->bytenr = root->node->start; + rb_node = rb_simple_insert(&rc->reloc_root_tree.rb_root, &node->simple_node); + spin_unlock(&rc->reloc_root_tree.lock); + if (rb_node) + btrfs_backref_panic(fs_info, node->bytenr, -EEXIST); return 0; } static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid) { + struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *reloc_root; struct extent_buffer *eb; - struct btrfs_root_item *root_item; + struct btrfs_root_item AUTO_KFREE(root_item); struct btrfs_key root_key; - u64 last_snap = 0; - int ret; + int ret = 0; root_item = kmalloc(sizeof(*root_item), GFP_NOFS); - BUG_ON(!root_item); + if (!root_item) + return ERR_PTR(-ENOMEM); root_key.objectid = BTRFS_TREE_RELOC_OBJECTID; root_key.type = BTRFS_ROOT_ITEM_KEY; root_key.offset = objectid; - if (root->root_key.objectid == objectid) { + if (btrfs_root_id(root) == objectid) { + u64 commit_root_gen; + + /* + * Relocation will wait for cleaner thread, and any half-dropped + * subvolume will be fully cleaned up at mount time. + * So here we shouldn't hit a subvolume with non-zero drop_progress. + * + * If this isn't the case, error out since it can make us attempt to + * drop references for extents that were already dropped before. + */ + if (unlikely(btrfs_disk_key_objectid(&root->root_item.drop_progress))) { + struct btrfs_key cpu_key; + + btrfs_disk_key_to_cpu(&cpu_key, &root->root_item.drop_progress); + btrfs_err(fs_info, + "cannot relocate partially dropped subvolume %llu, drop progress key " BTRFS_KEY_FMT, + objectid, BTRFS_KEY_FMT_VALUE(&cpu_key)); + return ERR_PTR(-EUCLEAN); + } + /* called by btrfs_init_reloc_root */ ret = btrfs_copy_root(trans, root, root->commit_root, &eb, BTRFS_TREE_RELOC_OBJECTID); - BUG_ON(ret); + if (ret) + return ERR_PTR(ret); - last_snap = btrfs_root_last_snapshot(&root->root_item); - btrfs_set_root_last_snapshot(&root->root_item, - trans->transid - 1); + /* + * Set the last_snapshot field to the generation of the commit + * root - like this ctree.c:btrfs_block_can_be_shared() behaves + * correctly (returns true) when the relocation root is created + * either inside the critical section of a transaction commit + * (through transaction.c:qgroup_account_snapshot()) and when + * it's created before the transaction commit is started. + */ + commit_root_gen = btrfs_header_generation(root->commit_root); + btrfs_set_root_last_snapshot(&root->root_item, commit_root_gen); } else { /* * called by btrfs_reloc_post_snapshot_hook. @@ -1334,74 +644,116 @@ static struct btrfs_root *create_reloc_root(struct btrfs_trans_handle *trans, */ ret = btrfs_copy_root(trans, root, root->node, &eb, BTRFS_TREE_RELOC_OBJECTID); - BUG_ON(ret); + if (ret) + return ERR_PTR(ret); } + /* + * We have changed references at this point, we must abort the + * transaction if anything fails (i.e. 'goto abort'). + */ + memcpy(root_item, &root->root_item, sizeof(*root_item)); btrfs_set_root_bytenr(root_item, eb->start); btrfs_set_root_level(root_item, btrfs_header_level(eb)); btrfs_set_root_generation(root_item, trans->transid); - if (root->root_key.objectid == objectid) { + if (btrfs_root_id(root) == objectid) { btrfs_set_root_refs(root_item, 0); memset(&root_item->drop_progress, 0, sizeof(struct btrfs_disk_key)); - root_item->drop_level = 0; - /* - * abuse rtransid, it is safe because it is impossible to - * receive data into a relocation tree. - */ - btrfs_set_root_rtransid(root_item, last_snap); - btrfs_set_root_otransid(root_item, trans->transid); + btrfs_set_root_drop_level(root_item, 0); } btrfs_tree_unlock(eb); free_extent_buffer(eb); - ret = btrfs_insert_root(trans, root->fs_info->tree_root, + ret = btrfs_insert_root(trans, fs_info->tree_root, &root_key, root_item); - BUG_ON(ret); - kfree(root_item); + if (ret) + goto abort; - reloc_root = btrfs_read_fs_root(root->fs_info->tree_root, &root_key); - BUG_ON(IS_ERR(reloc_root)); - reloc_root->last_trans = trans->transid; + reloc_root = btrfs_read_tree_root(fs_info->tree_root, &root_key); + if (IS_ERR(reloc_root)) { + ret = PTR_ERR(reloc_root); + goto abort; + } + set_bit(BTRFS_ROOT_SHAREABLE, &reloc_root->state); + btrfs_set_root_last_trans(reloc_root, trans->transid); return reloc_root; + +abort: + btrfs_abort_transaction(trans, ret); + return ERR_PTR(ret); } /* * create reloc tree for a given fs tree. reloc tree is just a * snapshot of the fs tree with special root objectid. + * + * The reloc_root comes out of here with two references, one for + * root->reloc_root, and another for being on the rc->reloc_roots list. */ int btrfs_init_reloc_root(struct btrfs_trans_handle *trans, struct btrfs_root *root) { + struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *reloc_root; - struct reloc_control *rc = root->fs_info->reloc_ctl; + struct reloc_control *rc = fs_info->reloc_ctl; + struct btrfs_block_rsv *rsv; int clear_rsv = 0; int ret; + if (!rc) + return 0; + + /* + * The subvolume has reloc tree but the swap is finished, no need to + * create/update the dead reloc tree + */ + if (reloc_root_is_dead(root)) + return 0; + + /* + * This is subtle but important. We do not do + * record_root_in_transaction for reloc roots, instead we record their + * corresponding fs root, and then here we update the last trans for the + * reloc root. This means that we have to do this for the entire life + * of the reloc root, regardless of which stage of the relocation we are + * in. + */ if (root->reloc_root) { reloc_root = root->reloc_root; - reloc_root->last_trans = trans->transid; + btrfs_set_root_last_trans(reloc_root, trans->transid); return 0; } - if (!rc || !rc->create_reloc_tree || - root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) + /* + * We are merging reloc roots, we do not need new reloc trees. Also + * reloc trees never need their own reloc tree. + */ + if (!rc->create_reloc_tree || btrfs_root_id(root) == BTRFS_TREE_RELOC_OBJECTID) return 0; - if (!trans->block_rsv) { + if (!trans->reloc_reserved) { + rsv = trans->block_rsv; trans->block_rsv = rc->block_rsv; clear_rsv = 1; } - reloc_root = create_reloc_root(trans, root, root->root_key.objectid); + reloc_root = create_reloc_root(trans, root, btrfs_root_id(root)); if (clear_rsv) - trans->block_rsv = NULL; + trans->block_rsv = rsv; + if (IS_ERR(reloc_root)) + return PTR_ERR(reloc_root); ret = __add_reloc_root(reloc_root); - BUG_ON(ret < 0); - root->reloc_root = reloc_root; + ASSERT(ret != -EEXIST); + if (ret) { + /* Pairs with create_reloc_root */ + btrfs_put_root(reloc_root); + return ret; + } + root->reloc_root = btrfs_grab_root(reloc_root); return 0; } @@ -1411,100 +763,47 @@ int btrfs_init_reloc_root(struct btrfs_trans_handle *trans, int btrfs_update_reloc_root(struct btrfs_trans_handle *trans, struct btrfs_root *root) { + struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *reloc_root; struct btrfs_root_item *root_item; - int del = 0; int ret; - if (!root->reloc_root) - goto out; + if (!have_reloc_root(root)) + return 0; reloc_root = root->reloc_root; root_item = &reloc_root->root_item; - if (root->fs_info->reloc_ctl->merge_reloc_tree && + /* + * We are probably ok here, but __del_reloc_root() will drop its ref of + * the root. We have the ref for root->reloc_root, but just in case + * hold it while we update the reloc root. + */ + btrfs_grab_root(reloc_root); + + /* root->reloc_root will stay until current relocation finished */ + if (fs_info->reloc_ctl && fs_info->reloc_ctl->merge_reloc_tree && btrfs_root_refs(root_item) == 0) { - root->reloc_root = NULL; - del = 1; + set_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state); + /* + * Mark the tree as dead before we change reloc_root so + * have_reloc_root will not touch it from now on. + */ + smp_wmb(); + __del_reloc_root(reloc_root); } - __update_reloc_root(reloc_root, del); - if (reloc_root->commit_root != reloc_root->node) { + __update_reloc_root(reloc_root); btrfs_set_root_node(root_item, reloc_root->node); free_extent_buffer(reloc_root->commit_root); reloc_root->commit_root = btrfs_root_node(reloc_root); } - ret = btrfs_update_root(trans, root->fs_info->tree_root, + ret = btrfs_update_root(trans, fs_info->tree_root, &reloc_root->root_key, root_item); - BUG_ON(ret); - -out: - return 0; -} - -/* - * helper to find first cached inode with inode number >= objectid - * in a subvolume - */ -static struct inode *find_next_inode(struct btrfs_root *root, u64 objectid) -{ - struct rb_node *node; - struct rb_node *prev; - struct btrfs_inode *entry; - struct inode *inode; - - spin_lock(&root->inode_lock); -again: - node = root->inode_tree.rb_node; - prev = NULL; - while (node) { - prev = node; - entry = rb_entry(node, struct btrfs_inode, rb_node); - - if (objectid < btrfs_ino(&entry->vfs_inode)) - node = node->rb_left; - else if (objectid > btrfs_ino(&entry->vfs_inode)) - node = node->rb_right; - else - break; - } - if (!node) { - while (prev) { - entry = rb_entry(prev, struct btrfs_inode, rb_node); - if (objectid <= btrfs_ino(&entry->vfs_inode)) { - node = prev; - break; - } - prev = rb_next(prev); - } - } - while (node) { - entry = rb_entry(node, struct btrfs_inode, rb_node); - inode = igrab(&entry->vfs_inode); - if (inode) { - spin_unlock(&root->inode_lock); - return inode; - } - - objectid = btrfs_ino(&entry->vfs_inode) + 1; - if (cond_resched_lock(&root->inode_lock)) - goto again; - - node = rb_next(node); - } - spin_unlock(&root->inode_lock); - return NULL; -} - -static int in_block_group(u64 bytenr, - struct btrfs_block_group_cache *block_group) -{ - if (bytenr >= block_group->key.objectid && - bytenr < block_group->key.objectid + block_group->key.offset) - return 1; - return 0; + btrfs_put_root(reloc_root); + return ret; } /* @@ -1514,7 +813,7 @@ static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr, u64 bytenr, u64 num_bytes) { struct btrfs_root *root = BTRFS_I(reloc_inode)->root; - struct btrfs_path *path; + BTRFS_PATH_AUTO_FREE(path); struct btrfs_file_extent_item *fi; struct extent_buffer *leaf; int ret; @@ -1523,15 +822,13 @@ static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr, if (!path) return -ENOMEM; - bytenr -= BTRFS_I(reloc_inode)->index_cnt; - ret = btrfs_lookup_file_extent(NULL, root, path, btrfs_ino(reloc_inode), - bytenr, 0); + bytenr -= BTRFS_I(reloc_inode)->reloc_block_group_start; + ret = btrfs_lookup_file_extent(NULL, root, path, + btrfs_ino(BTRFS_I(reloc_inode)), bytenr, 0); if (ret < 0) - goto out; - if (ret > 0) { - ret = -ENOENT; - goto out; - } + return ret; + if (ret > 0) + return -ENOENT; leaf = path->nodes[0]; fi = btrfs_item_ptr(leaf, path->slots[0], @@ -1542,16 +839,11 @@ static int get_new_location(struct inode *reloc_inode, u64 *new_bytenr, btrfs_file_extent_encryption(leaf, fi) || btrfs_file_extent_other_encoding(leaf, fi)); - if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) { - ret = 1; - goto out; - } + if (num_bytes != btrfs_file_extent_disk_num_bytes(leaf, fi)) + return -EINVAL; *new_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); - ret = 0; -out: - btrfs_free_path(path); - return ret; + return 0; } /* @@ -1564,9 +856,10 @@ int replace_file_extents(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *leaf) { + struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_key key; struct btrfs_file_extent_item *fi; - struct inode *inode = NULL; + struct btrfs_inode *inode = NULL; u64 parent; u64 bytenr; u64 new_bytenr = 0; @@ -1574,21 +867,22 @@ int replace_file_extents(struct btrfs_trans_handle *trans, u64 end; u32 nritems; u32 i; - int ret; + int ret = 0; int first = 1; - int dirty = 0; if (rc->stage != UPDATE_DATA_PTRS) return 0; /* reloc trees always use full backref */ - if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) + if (btrfs_root_id(root) == BTRFS_TREE_RELOC_OBJECTID) parent = leaf->start; else parent = 0; nritems = btrfs_header_nritems(leaf); for (i = 0; i < nritems; i++) { + struct btrfs_ref ref = { 0 }; + cond_resched(); btrfs_item_key_to_cpu(leaf, &key, i); if (key.type != BTRFS_EXTENT_DATA_KEY) @@ -1601,73 +895,97 @@ int replace_file_extents(struct btrfs_trans_handle *trans, num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); if (bytenr == 0) continue; - if (!in_block_group(bytenr, rc->block_group)) + if (!in_range(bytenr, rc->block_group->start, + rc->block_group->length)) continue; /* - * if we are modifying block in fs tree, wait for readpage + * if we are modifying block in fs tree, wait for read_folio * to complete and drop the extent cache */ - if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { + if (btrfs_root_id(root) != BTRFS_TREE_RELOC_OBJECTID) { if (first) { - inode = find_next_inode(root, key.objectid); + inode = btrfs_find_first_inode(root, key.objectid); first = 0; } else if (inode && btrfs_ino(inode) < key.objectid) { btrfs_add_delayed_iput(inode); - inode = find_next_inode(root, key.objectid); + inode = btrfs_find_first_inode(root, key.objectid); } if (inode && btrfs_ino(inode) == key.objectid) { + struct extent_state *cached_state = NULL; + end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); WARN_ON(!IS_ALIGNED(key.offset, - root->sectorsize)); - WARN_ON(!IS_ALIGNED(end, root->sectorsize)); + fs_info->sectorsize)); + WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize)); end--; - ret = try_lock_extent(&BTRFS_I(inode)->io_tree, - key.offset, end); - if (!ret) + /* Take mmap lock to serialize with reflinks. */ + if (!down_read_trylock(&inode->i_mmap_lock)) continue; + ret = btrfs_try_lock_extent(&inode->io_tree, key.offset, + end, &cached_state); + if (!ret) { + up_read(&inode->i_mmap_lock); + continue; + } - btrfs_drop_extent_cache(inode, key.offset, end, - 1); - unlock_extent(&BTRFS_I(inode)->io_tree, - key.offset, end); + btrfs_drop_extent_map_range(inode, key.offset, end, true); + btrfs_unlock_extent(&inode->io_tree, key.offset, end, + &cached_state); + up_read(&inode->i_mmap_lock); } } ret = get_new_location(rc->data_inode, &new_bytenr, bytenr, num_bytes); - if (ret > 0) { - WARN_ON(1); - continue; + if (ret) { + /* + * Don't have to abort since we've not changed anything + * in the file extent yet. + */ + break; } - BUG_ON(ret < 0); btrfs_set_file_extent_disk_bytenr(leaf, fi, new_bytenr); - dirty = 1; key.offset -= btrfs_file_extent_offset(leaf, fi); - ret = btrfs_inc_extent_ref(trans, root, new_bytenr, - num_bytes, parent, - btrfs_header_owner(leaf), - key.objectid, key.offset, 1); - BUG_ON(ret); - - ret = btrfs_free_extent(trans, root, bytenr, num_bytes, - parent, btrfs_header_owner(leaf), - key.objectid, key.offset, 1); - BUG_ON(ret); + ref.action = BTRFS_ADD_DELAYED_REF; + ref.bytenr = new_bytenr; + ref.num_bytes = num_bytes; + ref.parent = parent; + ref.owning_root = btrfs_root_id(root); + ref.ref_root = btrfs_header_owner(leaf); + btrfs_init_data_ref(&ref, key.objectid, key.offset, + btrfs_root_id(root), false); + ret = btrfs_inc_extent_ref(trans, &ref); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + break; + } + + ref.action = BTRFS_DROP_DELAYED_REF; + ref.bytenr = bytenr; + ref.num_bytes = num_bytes; + ref.parent = parent; + ref.owning_root = btrfs_root_id(root); + ref.ref_root = btrfs_header_owner(leaf); + btrfs_init_data_ref(&ref, key.objectid, key.offset, + btrfs_root_id(root), false); + ret = btrfs_free_extent(trans, &ref); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + break; + } } - if (dirty) - btrfs_mark_buffer_dirty(leaf); if (inode) btrfs_add_delayed_iput(inode); - return 0; + return ret; } -static noinline_for_stack -int memcmp_node_keys(struct extent_buffer *eb, int slot, - struct btrfs_path *path, int level) +static noinline_for_stack int memcmp_node_keys(const struct extent_buffer *eb, + int slot, const struct btrfs_path *path, + int level) { struct btrfs_disk_key key1; struct btrfs_disk_key key2; @@ -1686,13 +1004,15 @@ int memcmp_node_keys(struct extent_buffer *eb, int slot, * errors, a negative error number is returned. */ static noinline_for_stack -int replace_path(struct btrfs_trans_handle *trans, +int replace_path(struct btrfs_trans_handle *trans, struct reloc_control *rc, struct btrfs_root *dest, struct btrfs_root *src, struct btrfs_path *path, struct btrfs_key *next_key, int lowest_level, int max_level) { + struct btrfs_fs_info *fs_info = dest->fs_info; struct extent_buffer *eb; struct extent_buffer *parent; + struct btrfs_ref ref = { 0 }; struct btrfs_key key; u64 old_bytenr; u64 new_bytenr; @@ -1705,8 +1025,8 @@ int replace_path(struct btrfs_trans_handle *trans, int ret; int slot; - BUG_ON(src->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); - BUG_ON(dest->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID); + ASSERT(btrfs_root_id(src) == BTRFS_TREE_RELOC_OBJECTID); + ASSERT(btrfs_root_id(dest) != BTRFS_TREE_RELOC_OBJECTID); last_snapshot = btrfs_root_last_snapshot(&src->root_item); again: @@ -1714,7 +1034,6 @@ again: btrfs_node_key_to_cpu(path->nodes[lowest_level], &key, slot); eb = btrfs_lock_root_node(dest); - btrfs_set_lock_blocking(eb); level = btrfs_header_level(eb); if (level < lowest_level) { @@ -1724,10 +1043,14 @@ again: } if (cow) { - ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb); - BUG_ON(ret); + ret = btrfs_cow_block(trans, dest, eb, NULL, 0, &eb, + BTRFS_NESTING_COW); + if (ret) { + btrfs_tree_unlock(eb); + free_extent_buffer(eb); + return ret; + } } - btrfs_set_lock_blocking(eb); if (next_key) { next_key->objectid = (u64)-1; @@ -1738,9 +1061,11 @@ again: parent = eb; while (1) { level = btrfs_header_level(parent); - BUG_ON(level < lowest_level); + ASSERT(level >= lowest_level); - ret = btrfs_bin_search(parent, &key, level, &slot); + ret = btrfs_bin_search(parent, 0, &key, &slot); + if (ret < 0) + break; if (ret && slot > 0) slot--; @@ -1748,7 +1073,7 @@ again: btrfs_node_key_to_cpu(parent, next_key, slot + 1); old_bytenr = btrfs_node_blockptr(parent, slot); - blocksize = btrfs_level_size(dest, level - 1); + blocksize = fs_info->nodesize; old_ptr_gen = btrfs_node_ptr_generation(parent, slot); if (level <= max_level) { @@ -1762,8 +1087,7 @@ again: new_ptr_gen = 0; } - if (new_bytenr > 0 && new_bytenr == old_bytenr) { - WARN_ON(1); + if (WARN_ON(new_bytenr > 0 && new_bytenr == old_bytenr)) { ret = level; break; } @@ -1775,20 +1099,22 @@ again: break; } - eb = read_tree_block(dest, old_bytenr, blocksize, - old_ptr_gen); - if (!eb || !extent_buffer_uptodate(eb)) { - ret = (!eb) ? -ENOMEM : -EIO; - free_extent_buffer(eb); + eb = btrfs_read_node_slot(parent, slot); + if (IS_ERR(eb)) { + ret = PTR_ERR(eb); break; } btrfs_tree_lock(eb); if (cow) { ret = btrfs_cow_block(trans, dest, eb, parent, - slot, &eb); - BUG_ON(ret); + slot, &eb, + BTRFS_NESTING_COW); + if (ret) { + btrfs_tree_unlock(eb); + free_extent_buffer(eb); + break; + } } - btrfs_set_lock_blocking(eb); btrfs_tree_unlock(parent); free_extent_buffer(parent); @@ -1809,43 +1135,100 @@ again: btrfs_release_path(path); path->lowest_level = level; + set_bit(BTRFS_ROOT_RESET_LOCKDEP_CLASS, &src->state); ret = btrfs_search_slot(trans, src, &key, path, 0, 1); + clear_bit(BTRFS_ROOT_RESET_LOCKDEP_CLASS, &src->state); path->lowest_level = 0; - BUG_ON(ret); + if (ret) { + if (ret > 0) + ret = -ENOENT; + break; + } /* + * Info qgroup to trace both subtrees. + * + * We must trace both trees. + * 1) Tree reloc subtree + * If not traced, we will leak data numbers + * 2) Fs subtree + * If not traced, we will double count old data + * + * We don't scan the subtree right now, but only record + * the swapped tree blocks. + * The real subtree rescan is delayed until we have new + * CoW on the subtree root node before transaction commit. + */ + ret = btrfs_qgroup_add_swapped_blocks(dest, + rc->block_group, parent, slot, + path->nodes[level], path->slots[level], + last_snapshot); + if (ret < 0) + break; + /* * swap blocks in fs tree and reloc tree. */ btrfs_set_node_blockptr(parent, slot, new_bytenr); btrfs_set_node_ptr_generation(parent, slot, new_ptr_gen); - btrfs_mark_buffer_dirty(parent); btrfs_set_node_blockptr(path->nodes[level], path->slots[level], old_bytenr); btrfs_set_node_ptr_generation(path->nodes[level], path->slots[level], old_ptr_gen); - btrfs_mark_buffer_dirty(path->nodes[level]); - - ret = btrfs_inc_extent_ref(trans, src, old_bytenr, blocksize, - path->nodes[level]->start, - src->root_key.objectid, level - 1, 0, - 1); - BUG_ON(ret); - ret = btrfs_inc_extent_ref(trans, dest, new_bytenr, blocksize, - 0, dest->root_key.objectid, level - 1, - 0, 1); - BUG_ON(ret); - - ret = btrfs_free_extent(trans, src, new_bytenr, blocksize, - path->nodes[level]->start, - src->root_key.objectid, level - 1, 0, - 1); - BUG_ON(ret); - - ret = btrfs_free_extent(trans, dest, old_bytenr, blocksize, - 0, dest->root_key.objectid, level - 1, - 0, 1); - BUG_ON(ret); + + ref.action = BTRFS_ADD_DELAYED_REF; + ref.bytenr = old_bytenr; + ref.num_bytes = blocksize; + ref.parent = path->nodes[level]->start; + ref.owning_root = btrfs_root_id(src); + ref.ref_root = btrfs_root_id(src); + btrfs_init_tree_ref(&ref, level - 1, 0, true); + ret = btrfs_inc_extent_ref(trans, &ref); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + break; + } + + ref.action = BTRFS_ADD_DELAYED_REF; + ref.bytenr = new_bytenr; + ref.num_bytes = blocksize; + ref.parent = 0; + ref.owning_root = btrfs_root_id(dest); + ref.ref_root = btrfs_root_id(dest); + btrfs_init_tree_ref(&ref, level - 1, 0, true); + ret = btrfs_inc_extent_ref(trans, &ref); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + break; + } + + /* We don't know the real owning_root, use 0. */ + ref.action = BTRFS_DROP_DELAYED_REF; + ref.bytenr = new_bytenr; + ref.num_bytes = blocksize; + ref.parent = path->nodes[level]->start; + ref.owning_root = 0; + ref.ref_root = btrfs_root_id(src); + btrfs_init_tree_ref(&ref, level - 1, 0, true); + ret = btrfs_free_extent(trans, &ref); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + break; + } + + /* We don't know the real owning_root, use 0. */ + ref.action = BTRFS_DROP_DELAYED_REF; + ref.bytenr = old_bytenr; + ref.num_bytes = blocksize; + ref.parent = 0; + ref.owning_root = 0; + ref.ref_root = btrfs_root_id(dest); + btrfs_init_tree_ref(&ref, level - 1, 0, true); + ret = btrfs_free_extent(trans, &ref); + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + break; + } btrfs_unlock_up_safe(path, 0); @@ -1903,10 +1286,8 @@ int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path, { struct extent_buffer *eb = NULL; int i; - u64 bytenr; u64 ptr_gen = 0; u64 last_snapshot; - u32 blocksize; u32 nritems; last_snapshot = btrfs_root_last_snapshot(&root->root_item); @@ -1931,13 +1312,9 @@ int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path, return 0; } - bytenr = btrfs_node_blockptr(eb, path->slots[i]); - blocksize = btrfs_level_size(root, i - 1); - eb = read_tree_block(root, bytenr, blocksize, ptr_gen); - if (!eb || !extent_buffer_uptodate(eb)) { - free_extent_buffer(eb); - return -EIO; - } + eb = btrfs_read_node_slot(eb, path->slots[i]); + if (IS_ERR(eb)) + return PTR_ERR(eb); BUG_ON(btrfs_header_level(eb) != i - 1); path->nodes[i - 1] = eb; path->slots[i - 1] = 0; @@ -1950,34 +1327,38 @@ int walk_down_reloc_tree(struct btrfs_root *root, struct btrfs_path *path, * [min_key, max_key) */ static int invalidate_extent_cache(struct btrfs_root *root, - struct btrfs_key *min_key, - struct btrfs_key *max_key) + const struct btrfs_key *min_key, + const struct btrfs_key *max_key) { - struct inode *inode = NULL; + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_inode *inode = NULL; u64 objectid; u64 start, end; u64 ino; objectid = min_key->objectid; while (1) { + struct extent_state *cached_state = NULL; + cond_resched(); - iput(inode); + if (inode) + iput(&inode->vfs_inode); if (objectid > max_key->objectid) break; - inode = find_next_inode(root, objectid); + inode = btrfs_find_first_inode(root, objectid); if (!inode) break; ino = btrfs_ino(inode); if (ino > max_key->objectid) { - iput(inode); + iput(&inode->vfs_inode); break; } objectid = ino + 1; - if (!S_ISREG(inode->i_mode)) + if (!S_ISREG(inode->vfs_inode.i_mode)) continue; if (unlikely(min_key->objectid == ino)) { @@ -1987,7 +1368,7 @@ static int invalidate_extent_cache(struct btrfs_root *root, start = 0; else { start = min_key->offset; - WARN_ON(!IS_ALIGNED(start, root->sectorsize)); + WARN_ON(!IS_ALIGNED(start, fs_info->sectorsize)); } } else { start = 0; @@ -2002,17 +1383,17 @@ static int invalidate_extent_cache(struct btrfs_root *root, if (max_key->offset == 0) continue; end = max_key->offset; - WARN_ON(!IS_ALIGNED(end, root->sectorsize)); + WARN_ON(!IS_ALIGNED(end, fs_info->sectorsize)); end--; } } else { end = (u64)-1; } - /* the lock_extent waits for readpage to complete */ - lock_extent(&BTRFS_I(inode)->io_tree, start, end); - btrfs_drop_extent_cache(inode, start, end, 1); - unlock_extent(&BTRFS_I(inode)->io_tree, start, end); + /* the lock_extent waits for read_folio to complete */ + btrfs_lock_extent(&inode->io_tree, start, end, &cached_state); + btrfs_drop_extent_map_range(inode, start, end, true); + btrfs_unlock_extent(&inode->io_tree, start, end, &cached_state); } return 0; } @@ -2036,44 +1417,124 @@ static int find_next_key(struct btrfs_path *path, int level, } /* + * Insert current subvolume into reloc_control::dirty_subvol_roots + */ +static int insert_dirty_subvol(struct btrfs_trans_handle *trans, + struct reloc_control *rc, + struct btrfs_root *root) +{ + struct btrfs_root *reloc_root = root->reloc_root; + struct btrfs_root_item *reloc_root_item; + int ret; + + /* @root must be a subvolume tree root with a valid reloc tree */ + ASSERT(btrfs_root_id(root) != BTRFS_TREE_RELOC_OBJECTID); + ASSERT(reloc_root); + + reloc_root_item = &reloc_root->root_item; + memset(&reloc_root_item->drop_progress, 0, + sizeof(reloc_root_item->drop_progress)); + btrfs_set_root_drop_level(reloc_root_item, 0); + btrfs_set_root_refs(reloc_root_item, 0); + ret = btrfs_update_reloc_root(trans, root); + if (ret) + return ret; + + if (list_empty(&root->reloc_dirty_list)) { + btrfs_grab_root(root); + list_add_tail(&root->reloc_dirty_list, &rc->dirty_subvol_roots); + } + + return 0; +} + +static int clean_dirty_subvols(struct reloc_control *rc) +{ + struct btrfs_root *root; + struct btrfs_root *next; + int ret = 0; + int ret2; + + list_for_each_entry_safe(root, next, &rc->dirty_subvol_roots, + reloc_dirty_list) { + if (btrfs_root_id(root) != BTRFS_TREE_RELOC_OBJECTID) { + /* Merged subvolume, cleanup its reloc root */ + struct btrfs_root *reloc_root = root->reloc_root; + + list_del_init(&root->reloc_dirty_list); + root->reloc_root = NULL; + /* + * Need barrier to ensure clear_bit() only happens after + * root->reloc_root = NULL. Pairs with have_reloc_root. + */ + smp_wmb(); + clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE, &root->state); + if (reloc_root) { + /* + * btrfs_drop_snapshot drops our ref we hold for + * ->reloc_root. If it fails however we must + * drop the ref ourselves. + */ + ret2 = btrfs_drop_snapshot(reloc_root, false, true); + if (ret2 < 0) { + btrfs_put_root(reloc_root); + if (!ret) + ret = ret2; + } + } + btrfs_put_root(root); + } else { + /* Orphan reloc tree, just clean it up */ + ret2 = btrfs_drop_snapshot(root, false, true); + if (ret2 < 0) { + btrfs_put_root(root); + if (!ret) + ret = ret2; + } + } + } + return ret; +} + +/* * merge the relocated tree blocks in reloc tree with corresponding * fs tree. */ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc, struct btrfs_root *root) { - LIST_HEAD(inode_list); + struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; struct btrfs_key key; struct btrfs_key next_key; - struct btrfs_trans_handle *trans; + struct btrfs_trans_handle *trans = NULL; struct btrfs_root *reloc_root; struct btrfs_root_item *root_item; struct btrfs_path *path; struct extent_buffer *leaf; + int reserve_level; int level; int max_level; int replaced = 0; - int ret; - int err = 0; + int ret = 0; u32 min_reserved; path = btrfs_alloc_path(); if (!path) return -ENOMEM; - path->reada = 1; + path->reada = READA_FORWARD; reloc_root = root->reloc_root; root_item = &reloc_root->root_item; if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { level = btrfs_root_level(root_item); - extent_buffer_get(reloc_root->node); + refcount_inc(&reloc_root->node->refs); path->nodes[level] = reloc_root->node; path->slots[level] = 0; } else { btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); - level = root_item->drop_level; + level = btrfs_root_drop_level(root_item); BUG_ON(level == 0); path->lowest_level = level; ret = btrfs_search_slot(NULL, reloc_root, &key, path, 0, 0); @@ -2090,31 +1551,50 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc, btrfs_unlock_up_safe(path, 0); } - min_reserved = root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2; + /* + * In merge_reloc_root(), we modify the upper level pointer to swap the + * tree blocks between reloc tree and subvolume tree. Thus for tree + * block COW, we COW at most from level 1 to root level for each tree. + * + * Thus the needed metadata size is at most root_level * nodesize, + * and * 2 since we have two trees to COW. + */ + reserve_level = max_t(int, 1, btrfs_root_level(root_item)); + min_reserved = fs_info->nodesize * reserve_level * 2; memset(&next_key, 0, sizeof(next_key)); while (1) { + ret = btrfs_block_rsv_refill(fs_info, rc->block_rsv, + min_reserved, + BTRFS_RESERVE_FLUSH_LIMIT); + if (ret) + goto out; trans = btrfs_start_transaction(root, 0); - BUG_ON(IS_ERR(trans)); - trans->block_rsv = rc->block_rsv; - - ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved, - BTRFS_RESERVE_FLUSH_ALL); - if (ret) { - BUG_ON(ret != -EAGAIN); - ret = btrfs_commit_transaction(trans, root); - BUG_ON(ret); - continue; + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + trans = NULL; + goto out; } + /* + * At this point we no longer have a reloc_control, so we can't + * depend on btrfs_init_reloc_root to update our last_trans. + * + * But that's ok, we started the trans handle on our + * corresponding fs_root, which means it's been added to the + * dirty list. At commit time we'll still call + * btrfs_update_reloc_root() and update our root item + * appropriately. + */ + btrfs_set_root_last_trans(reloc_root, trans->transid); + trans->block_rsv = rc->block_rsv; + replaced = 0; max_level = level; ret = walk_down_reloc_tree(reloc_root, path, &level); - if (ret < 0) { - err = ret; + if (ret < 0) goto out; - } if (ret > 0) break; @@ -2122,14 +1602,11 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc, btrfs_comp_cpu_keys(&next_key, &key) >= 0) { ret = 0; } else { - ret = replace_path(trans, root, reloc_root, path, + ret = replace_path(trans, rc, root, reloc_root, path, &next_key, level, max_level); } - if (ret < 0) { - err = ret; + if (ret < 0) goto out; - } - if (ret > 0) { level = ret; btrfs_node_key_to_cpu(path->nodes[level], &key, @@ -2148,11 +1625,12 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc, */ btrfs_node_key(path->nodes[level], &root_item->drop_progress, path->slots[level]); - root_item->drop_level = level; + btrfs_set_root_drop_level(root_item, level); - btrfs_end_transaction_throttle(trans, root); + btrfs_end_transaction_throttle(trans); + trans = NULL; - btrfs_btree_balance_dirty(root); + btrfs_btree_balance_dirty(fs_info); if (replaced && rc->stage == UPDATE_DATA_PTRS) invalidate_extent_cache(root, &key, &next_key); @@ -2163,51 +1641,50 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc, * relocated and the block is tree root. */ leaf = btrfs_lock_root_node(root); - ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf); + ret = btrfs_cow_block(trans, root, leaf, NULL, 0, &leaf, + BTRFS_NESTING_COW); btrfs_tree_unlock(leaf); free_extent_buffer(leaf); - if (ret < 0) - err = ret; out: btrfs_free_path(path); - if (err == 0) { - memset(&root_item->drop_progress, 0, - sizeof(root_item->drop_progress)); - root_item->drop_level = 0; - btrfs_set_root_refs(root_item, 0); - btrfs_update_reloc_root(trans, root); + if (ret == 0) { + ret = insert_dirty_subvol(trans, rc, root); + if (ret) + btrfs_abort_transaction(trans, ret); } - btrfs_end_transaction_throttle(trans, root); + if (trans) + btrfs_end_transaction_throttle(trans); - btrfs_btree_balance_dirty(root); + btrfs_btree_balance_dirty(fs_info); if (replaced && rc->stage == UPDATE_DATA_PTRS) invalidate_extent_cache(root, &key, &next_key); - return err; + return ret; } static noinline_for_stack int prepare_to_merge(struct reloc_control *rc, int err) { struct btrfs_root *root = rc->extent_root; + struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *reloc_root; struct btrfs_trans_handle *trans; LIST_HEAD(reloc_roots); u64 num_bytes = 0; int ret; - mutex_lock(&root->fs_info->reloc_mutex); - rc->merging_rsv_size += root->nodesize * (BTRFS_MAX_LEVEL - 1) * 2; + mutex_lock(&fs_info->reloc_mutex); + rc->merging_rsv_size += fs_info->nodesize * (BTRFS_MAX_LEVEL - 1) * 2; rc->merging_rsv_size += rc->nodes_relocated * 2; - mutex_unlock(&root->fs_info->reloc_mutex); + mutex_unlock(&fs_info->reloc_mutex); again: if (!err) { num_bytes = rc->merging_rsv_size; - ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes, + ret = btrfs_block_rsv_add(fs_info, rc->block_rsv, num_bytes, BTRFS_RESERVE_FLUSH_ALL); if (ret) err = ret; @@ -2216,31 +1693,73 @@ again: trans = btrfs_join_transaction(rc->extent_root); if (IS_ERR(trans)) { if (!err) - btrfs_block_rsv_release(rc->extent_root, - rc->block_rsv, num_bytes); + btrfs_block_rsv_release(fs_info, rc->block_rsv, + num_bytes, NULL); return PTR_ERR(trans); } if (!err) { if (num_bytes != rc->merging_rsv_size) { - btrfs_end_transaction(trans, rc->extent_root); - btrfs_block_rsv_release(rc->extent_root, - rc->block_rsv, num_bytes); + btrfs_end_transaction(trans); + btrfs_block_rsv_release(fs_info, rc->block_rsv, + num_bytes, NULL); goto again; } } - rc->merge_reloc_tree = 1; + rc->merge_reloc_tree = true; while (!list_empty(&rc->reloc_roots)) { - reloc_root = list_entry(rc->reloc_roots.next, - struct btrfs_root, root_list); + reloc_root = list_first_entry(&rc->reloc_roots, + struct btrfs_root, root_list); list_del_init(&reloc_root->root_list); - root = read_fs_root(reloc_root->fs_info, - reloc_root->root_key.offset); - BUG_ON(IS_ERR(root)); - BUG_ON(root->reloc_root != reloc_root); + root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset, + false); + if (IS_ERR(root)) { + /* + * Even if we have an error we need this reloc root + * back on our list so we can clean up properly. + */ + list_add(&reloc_root->root_list, &reloc_roots); + btrfs_abort_transaction(trans, (int)PTR_ERR(root)); + if (!err) + err = PTR_ERR(root); + break; + } + + if (unlikely(root->reloc_root != reloc_root)) { + if (root->reloc_root) { + btrfs_err(fs_info, +"reloc tree mismatch, root %lld has reloc root key (%lld %u %llu) gen %llu, expect reloc root key (%lld %u %llu) gen %llu", + btrfs_root_id(root), + btrfs_root_id(root->reloc_root), + root->reloc_root->root_key.type, + root->reloc_root->root_key.offset, + btrfs_root_generation( + &root->reloc_root->root_item), + btrfs_root_id(reloc_root), + reloc_root->root_key.type, + reloc_root->root_key.offset, + btrfs_root_generation( + &reloc_root->root_item)); + } else { + btrfs_err(fs_info, +"reloc tree mismatch, root %lld has no reloc root, expect reloc root key (%lld %u %llu) gen %llu", + btrfs_root_id(root), + btrfs_root_id(reloc_root), + reloc_root->root_key.type, + reloc_root->root_key.offset, + btrfs_root_generation( + &reloc_root->root_item)); + } + list_add(&reloc_root->root_list, &reloc_roots); + btrfs_put_root(root); + btrfs_abort_transaction(trans, -EUCLEAN); + if (!err) + err = -EUCLEAN; + break; + } /* * set reference count to 1, so btrfs_recover_relocation @@ -2248,44 +1767,47 @@ again: */ if (!err) btrfs_set_root_refs(&reloc_root->root_item, 1); - btrfs_update_reloc_root(trans, root); + ret = btrfs_update_reloc_root(trans, root); + /* + * Even if we have an error we need this reloc root back on our + * list so we can clean up properly. + */ list_add(&reloc_root->root_list, &reloc_roots); + btrfs_put_root(root); + + if (unlikely(ret)) { + btrfs_abort_transaction(trans, ret); + if (!err) + err = ret; + break; + } } list_splice(&reloc_roots, &rc->reloc_roots); if (!err) - btrfs_commit_transaction(trans, rc->extent_root); + err = btrfs_commit_transaction(trans); else - btrfs_end_transaction(trans, rc->extent_root); + btrfs_end_transaction(trans); return err; } static noinline_for_stack void free_reloc_roots(struct list_head *list) { - struct btrfs_root *reloc_root; + struct btrfs_root *reloc_root, *tmp; - while (!list_empty(list)) { - reloc_root = list_entry(list->next, struct btrfs_root, - root_list); - __update_reloc_root(reloc_root, 1); - free_extent_buffer(reloc_root->node); - free_extent_buffer(reloc_root->commit_root); - kfree(reloc_root); - } + list_for_each_entry_safe(reloc_root, tmp, list, root_list) + __del_reloc_root(reloc_root); } static noinline_for_stack -int merge_reloc_roots(struct reloc_control *rc) +void merge_reloc_roots(struct reloc_control *rc) { - struct btrfs_trans_handle *trans; + struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; struct btrfs_root *root; struct btrfs_root *reloc_root; - u64 last_snap; - u64 otransid; - u64 objectid; LIST_HEAD(reloc_roots); int found = 0; int ret = 0; @@ -2298,65 +1820,60 @@ again: * adding their roots to the list while we are * doing this splice */ - mutex_lock(&root->fs_info->reloc_mutex); + mutex_lock(&fs_info->reloc_mutex); list_splice_init(&rc->reloc_roots, &reloc_roots); - mutex_unlock(&root->fs_info->reloc_mutex); + mutex_unlock(&fs_info->reloc_mutex); while (!list_empty(&reloc_roots)) { found = 1; - reloc_root = list_entry(reloc_roots.next, - struct btrfs_root, root_list); + reloc_root = list_first_entry(&reloc_roots, struct btrfs_root, root_list); + root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset, + false); if (btrfs_root_refs(&reloc_root->root_item) > 0) { - root = read_fs_root(reloc_root->fs_info, - reloc_root->root_key.offset); - BUG_ON(IS_ERR(root)); - BUG_ON(root->reloc_root != reloc_root); - + if (WARN_ON(IS_ERR(root))) { + /* + * For recovery we read the fs roots on mount, + * and if we didn't find the root then we marked + * the reloc root as a garbage root. For normal + * relocation obviously the root should exist in + * memory. However there's no reason we can't + * handle the error properly here just in case. + */ + ret = PTR_ERR(root); + goto out; + } + if (WARN_ON(root->reloc_root != reloc_root)) { + /* + * This can happen if on-disk metadata has some + * corruption, e.g. bad reloc tree key offset. + */ + ret = -EINVAL; + goto out; + } ret = merge_reloc_root(rc, root); - if (ret) + btrfs_put_root(root); + if (ret) { + if (list_empty(&reloc_root->root_list)) + list_add_tail(&reloc_root->root_list, + &reloc_roots); goto out; + } } else { - list_del_init(&reloc_root->root_list); - } - - /* - * we keep the old last snapshod transid in rtranid when we - * created the relocation tree. - */ - last_snap = btrfs_root_rtransid(&reloc_root->root_item); - otransid = btrfs_root_otransid(&reloc_root->root_item); - objectid = reloc_root->root_key.offset; - - ret = btrfs_drop_snapshot(reloc_root, rc->block_rsv, 0, 1); - if (ret < 0) { - if (list_empty(&reloc_root->root_list)) - list_add_tail(&reloc_root->root_list, - &reloc_roots); - goto out; - } else if (!ret) { - /* - * recover the last snapshot tranid to avoid - * the space balance break NOCOW. - */ - root = read_fs_root(rc->extent_root->fs_info, - objectid); - if (IS_ERR(root)) - continue; - - if (btrfs_root_refs(&root->root_item) == 0) - continue; - - trans = btrfs_join_transaction(root); - BUG_ON(IS_ERR(trans)); + if (!IS_ERR(root)) { + if (root->reloc_root == reloc_root) { + root->reloc_root = NULL; + btrfs_put_root(reloc_root); + } + clear_bit(BTRFS_ROOT_DEAD_RELOC_TREE, + &root->state); + btrfs_put_root(root); + } - /* Check if the fs/file tree was snapshoted or not. */ - if (btrfs_root_last_snapshot(&root->root_item) == - otransid - 1) - btrfs_set_root_last_snapshot(&root->root_item, - last_snap); - - btrfs_end_transaction(trans, root); + list_del_init(&reloc_root->root_list); + /* Don't forget to queue this reloc root for cleanup */ + list_add_tail(&reloc_root->reloc_dirty_list, + &rc->dirty_subvol_roots); } } @@ -2366,13 +1883,31 @@ again: } out: if (ret) { - btrfs_std_error(root->fs_info, ret); - if (!list_empty(&reloc_roots)) - free_reloc_roots(&reloc_roots); + btrfs_handle_fs_error(fs_info, ret, NULL); + free_reloc_roots(&reloc_roots); + + /* new reloc root may be added */ + mutex_lock(&fs_info->reloc_mutex); + list_splice_init(&rc->reloc_roots, &reloc_roots); + mutex_unlock(&fs_info->reloc_mutex); + free_reloc_roots(&reloc_roots); } - BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root)); - return ret; + /* + * We used to have + * + * BUG_ON(!RB_EMPTY_ROOT(&rc->reloc_root_tree.rb_root)); + * + * here, but it's wrong. If we fail to start the transaction in + * prepare_to_merge() we will have only 0 ref reloc roots, none of which + * have actually been removed from the reloc_root_tree rb tree. This is + * fine because we're bailing here, and we hold a reference on the root + * for the list that holds it, so these roots will be cleaned up when we + * do the reloc_dirty_list afterwards. Meanwhile the root->reloc_root + * will be cleaned up on unmount. + * + * The remaining nodes will be cleaned up by free_reloc_control. + */ } static void free_block_list(struct rb_root *blocks) @@ -2389,65 +1924,118 @@ static void free_block_list(struct rb_root *blocks) static int record_reloc_root_in_trans(struct btrfs_trans_handle *trans, struct btrfs_root *reloc_root) { + struct btrfs_fs_info *fs_info = reloc_root->fs_info; struct btrfs_root *root; + int ret; - if (reloc_root->last_trans == trans->transid) + if (btrfs_get_root_last_trans(reloc_root) == trans->transid) return 0; - root = read_fs_root(reloc_root->fs_info, reloc_root->root_key.offset); - BUG_ON(IS_ERR(root)); - BUG_ON(root->reloc_root != reloc_root); + root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset, false); - return btrfs_record_root_in_trans(trans, root); + /* + * This should succeed, since we can't have a reloc root without having + * already looked up the actual root and created the reloc root for this + * root. + * + * However if there's some sort of corruption where we have a ref to a + * reloc root without a corresponding root this could return ENOENT. + */ + if (IS_ERR(root)) { + DEBUG_WARN("error %ld reading root for reloc root", PTR_ERR(root)); + return PTR_ERR(root); + } + if (unlikely(root->reloc_root != reloc_root)) { + DEBUG_WARN("unexpected reloc root found"); + btrfs_err(fs_info, + "root %llu has two reloc roots associated with it", + reloc_root->root_key.offset); + btrfs_put_root(root); + return -EUCLEAN; + } + ret = btrfs_record_root_in_trans(trans, root); + btrfs_put_root(root); + + return ret; } static noinline_for_stack struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans, struct reloc_control *rc, - struct backref_node *node, - struct backref_edge *edges[], int *nr) + struct btrfs_backref_node *node, + struct btrfs_backref_edge *edges[]) { - struct backref_node *next; + struct btrfs_backref_node *next; struct btrfs_root *root; int index = 0; + int ret; - next = node; - while (1) { - cond_resched(); - next = walk_up_backref(next, edges, &index); - root = next->root; - BUG_ON(!root); - BUG_ON(!root->ref_cows); - - if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID) { - record_reloc_root_in_trans(trans, root); - break; - } + next = walk_up_backref(node, edges, &index); + root = next->root; - btrfs_record_root_in_trans(trans, root); - root = root->reloc_root; - - if (next->new_bytenr != root->node->start) { - BUG_ON(next->new_bytenr); - BUG_ON(!list_empty(&next->list)); - next->new_bytenr = root->node->start; - next->root = root; - list_add_tail(&next->list, - &rc->backref_cache.changed); - __mark_block_processed(rc, next); - break; - } + /* + * If there is no root, then our references for this block are + * incomplete, as we should be able to walk all the way up to a block + * that is owned by a root. + * + * This path is only for SHAREABLE roots, so if we come upon a + * non-SHAREABLE root then we have backrefs that resolve improperly. + * + * Both of these cases indicate file system corruption, or a bug in the + * backref walking code. + */ + if (unlikely(!root)) { + btrfs_err(trans->fs_info, + "bytenr %llu doesn't have a backref path ending in a root", + node->bytenr); + return ERR_PTR(-EUCLEAN); + } + if (unlikely(!test_bit(BTRFS_ROOT_SHAREABLE, &root->state))) { + btrfs_err(trans->fs_info, + "bytenr %llu has multiple refs with one ending in a non-shareable root", + node->bytenr); + return ERR_PTR(-EUCLEAN); + } - WARN_ON(1); - root = NULL; - next = walk_down_backref(edges, &index); - if (!next || next->level <= node->level) - break; + if (btrfs_root_id(root) == BTRFS_TREE_RELOC_OBJECTID) { + ret = record_reloc_root_in_trans(trans, root); + if (ret) + return ERR_PTR(ret); + goto found; } + + ret = btrfs_record_root_in_trans(trans, root); + if (ret) + return ERR_PTR(ret); + root = root->reloc_root; + + /* + * We could have raced with another thread which failed, so + * root->reloc_root may not be set, return ENOENT in this case. + */ if (!root) - return NULL; + return ERR_PTR(-ENOENT); - *nr = index; + if (unlikely(next->new_bytenr)) { + /* + * We just created the reloc root, so we shouldn't have + * ->new_bytenr set yet. If it is then we have multiple roots + * pointing at the same bytenr which indicates corruption, or + * we've made a mistake in the backref walking code. + */ + ASSERT(next->new_bytenr == 0); + btrfs_err(trans->fs_info, + "bytenr %llu possibly has multiple roots pointing at the same bytenr %llu", + node->bytenr, next->bytenr); + return ERR_PTR(-EUCLEAN); + } + + next->new_bytenr = root->node->start; + btrfs_put_root(next->root); + next->root = btrfs_grab_root(root); + ASSERT(next->root); + mark_block_processed(rc, next); +found: next = node; /* setup backref node path for btrfs_reloc_cow_block */ while (1) { @@ -2460,19 +2048,21 @@ struct btrfs_root *select_reloc_root(struct btrfs_trans_handle *trans, } /* - * select a tree root for relocation. return NULL if the block - * is reference counted. we should use do_relocation() in this - * case. return a tree root pointer if the block isn't reference - * counted. return -ENOENT if the block is root of reloc tree. + * Select a tree root for relocation. + * + * Return NULL if the block is not shareable. We should use do_relocation() in + * this case. + * + * Return a tree root pointer if the block is shareable. + * Return -ENOENT if the block is root of reloc tree. */ static noinline_for_stack -struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans, - struct backref_node *node) +struct btrfs_root *select_one_root(struct btrfs_backref_node *node) { - struct backref_node *next; + struct btrfs_backref_node *next; struct btrfs_root *root; struct btrfs_root *fs_root = NULL; - struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; + struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1]; int index = 0; next = node; @@ -2480,13 +2070,19 @@ struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans, cond_resched(); next = walk_up_backref(next, edges, &index); root = next->root; - BUG_ON(!root); - /* no other choice for non-references counted tree */ - if (!root->ref_cows) + /* + * This can occur if we have incomplete extent refs leading all + * the way up a particular path, in this case return -EUCLEAN. + */ + if (unlikely(!root)) + return ERR_PTR(-EUCLEAN); + + /* No other choice for non-shareable tree */ + if (!test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) return root; - if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) + if (btrfs_root_id(root) != BTRFS_TREE_RELOC_OBJECTID) fs_root = root; if (next != node) @@ -2502,32 +2098,31 @@ struct btrfs_root *select_one_root(struct btrfs_trans_handle *trans, return fs_root; } -static noinline_for_stack -u64 calcu_metadata_size(struct reloc_control *rc, - struct backref_node *node, int reserve) +static noinline_for_stack u64 calcu_metadata_size(struct reloc_control *rc, + struct btrfs_backref_node *node) { - struct backref_node *next = node; - struct backref_edge *edge; - struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; + struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; + struct btrfs_backref_node *next = node; + struct btrfs_backref_edge *edge; + struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1]; u64 num_bytes = 0; int index = 0; - BUG_ON(reserve && node->processed); + BUG_ON(node->processed); while (next) { cond_resched(); while (1) { - if (next->processed && (reserve || next != node)) + if (next->processed) break; - num_bytes += btrfs_level_size(rc->extent_root, - next->level); + num_bytes += fs_info->nodesize; if (list_empty(&next->upper)) break; - edge = list_entry(next->upper.next, - struct backref_edge, list[LOWER]); + edge = list_first_entry(&next->upper, struct btrfs_backref_edge, + list[LOWER]); edges[index++] = edge; next = edge->node[UPPER]; } @@ -2536,33 +2131,50 @@ u64 calcu_metadata_size(struct reloc_control *rc, return num_bytes; } -static int reserve_metadata_space(struct btrfs_trans_handle *trans, - struct reloc_control *rc, - struct backref_node *node) +static int refill_metadata_space(struct btrfs_trans_handle *trans, + struct reloc_control *rc, u64 num_bytes) { - struct btrfs_root *root = rc->extent_root; - u64 num_bytes; + struct btrfs_fs_info *fs_info = trans->fs_info; int ret; - num_bytes = calcu_metadata_size(rc, node, 1) * 2; - trans->block_rsv = rc->block_rsv; - ret = btrfs_block_rsv_add(root, rc->block_rsv, num_bytes, - BTRFS_RESERVE_FLUSH_ALL); + rc->reserved_bytes += num_bytes; + + /* + * We are under a transaction here so we can only do limited flushing. + * If we get an enospc just kick back -EAGAIN so we know to drop the + * transaction and try to refill when we can flush all the things. + */ + ret = btrfs_block_rsv_refill(fs_info, rc->block_rsv, num_bytes, + BTRFS_RESERVE_FLUSH_LIMIT); if (ret) { - if (ret == -EAGAIN) - rc->commit_transaction = 1; - return ret; + u64 tmp = fs_info->nodesize * RELOCATION_RESERVED_NODES; + + while (tmp <= rc->reserved_bytes) + tmp <<= 1; + /* + * only one thread can access block_rsv at this point, + * so we don't need hold lock to protect block_rsv. + * we expand more reservation size here to allow enough + * space for relocation and we will return earlier in + * enospc case. + */ + rc->block_rsv->size = tmp + fs_info->nodesize * + RELOCATION_RESERVED_NODES; + return -EAGAIN; } return 0; } -static void release_metadata_space(struct reloc_control *rc, - struct backref_node *node) +static int reserve_metadata_space(struct btrfs_trans_handle *trans, + struct reloc_control *rc, + struct btrfs_backref_node *node) { - u64 num_bytes = calcu_metadata_size(rc, node, 0) * 2; - btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, num_bytes); + u64 num_bytes; + + num_bytes = calcu_metadata_size(rc, node) * 2; + return refill_metadata_space(trans, rc, num_bytes); } /* @@ -2574,24 +2186,25 @@ static void release_metadata_space(struct reloc_control *rc, */ static int do_relocation(struct btrfs_trans_handle *trans, struct reloc_control *rc, - struct backref_node *node, + struct btrfs_backref_node *node, struct btrfs_key *key, struct btrfs_path *path, int lowest) { - struct backref_node *upper; - struct backref_edge *edge; - struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; + struct btrfs_backref_node *upper; + struct btrfs_backref_edge *edge; + struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1]; struct btrfs_root *root; struct extent_buffer *eb; u32 blocksize; u64 bytenr; - u64 generation; - int nr; int slot; - int ret; - int err = 0; + int ret = 0; - BUG_ON(lowest && node->eb); + /* + * If we are lowest then this is the first time we're processing this + * block, and thus shouldn't have an eb associated with it yet. + */ + ASSERT(!lowest || !node->eb); path->lowest_level = node->level + 1; rc->backref_cache.path[node->level] = node; @@ -2599,28 +2212,34 @@ static int do_relocation(struct btrfs_trans_handle *trans, cond_resched(); upper = edge->node[UPPER]; - root = select_reloc_root(trans, rc, upper, edges, &nr); - BUG_ON(!root); + root = select_reloc_root(trans, rc, upper, edges); + if (IS_ERR(root)) { + ret = PTR_ERR(root); + goto next; + } if (upper->eb && !upper->locked) { if (!lowest) { - ret = btrfs_bin_search(upper->eb, key, - upper->level, &slot); + ret = btrfs_bin_search(upper->eb, 0, key, &slot); + if (ret < 0) + goto next; BUG_ON(ret); bytenr = btrfs_node_blockptr(upper->eb, slot); if (node->eb->start == bytenr) goto next; } - drop_node_buffer(upper); + btrfs_backref_drop_node_buffer(upper); } if (!upper->eb) { ret = btrfs_search_slot(trans, root, key, path, 0, 1); - if (ret < 0) { - err = ret; + if (ret) { + if (ret > 0) + ret = -ENOENT; + + btrfs_release_path(path); break; } - BUG_ON(ret > 0); if (!upper->eb) { upper->eb = path->nodes[upper->level]; @@ -2635,80 +2254,100 @@ static int do_relocation(struct btrfs_trans_handle *trans, slot = path->slots[upper->level]; btrfs_release_path(path); } else { - ret = btrfs_bin_search(upper->eb, key, upper->level, - &slot); + ret = btrfs_bin_search(upper->eb, 0, key, &slot); + if (ret < 0) + goto next; BUG_ON(ret); } bytenr = btrfs_node_blockptr(upper->eb, slot); if (lowest) { - BUG_ON(bytenr != node->bytenr); + if (unlikely(bytenr != node->bytenr)) { + btrfs_err(root->fs_info, + "lowest leaf/node mismatch: bytenr %llu node->bytenr %llu slot %d upper %llu", + bytenr, node->bytenr, slot, + upper->eb->start); + ret = -EIO; + goto next; + } } else { if (node->eb->start == bytenr) goto next; } - blocksize = btrfs_level_size(root, node->level); - generation = btrfs_node_ptr_generation(upper->eb, slot); - eb = read_tree_block(root, bytenr, blocksize, generation); - if (!eb || !extent_buffer_uptodate(eb)) { - free_extent_buffer(eb); - err = -EIO; + blocksize = root->fs_info->nodesize; + eb = btrfs_read_node_slot(upper->eb, slot); + if (IS_ERR(eb)) { + ret = PTR_ERR(eb); goto next; } btrfs_tree_lock(eb); - btrfs_set_lock_blocking(eb); if (!node->eb) { ret = btrfs_cow_block(trans, root, eb, upper->eb, - slot, &eb); + slot, &eb, BTRFS_NESTING_COW); btrfs_tree_unlock(eb); free_extent_buffer(eb); - if (ret < 0) { - err = ret; + if (ret < 0) goto next; - } - BUG_ON(node->eb != eb); + /* + * We've just COWed this block, it should have updated + * the correct backref node entry. + */ + ASSERT(node->eb == eb); } else { + struct btrfs_ref ref = { + .action = BTRFS_ADD_DELAYED_REF, + .bytenr = node->eb->start, + .num_bytes = blocksize, + .parent = upper->eb->start, + .owning_root = btrfs_header_owner(upper->eb), + .ref_root = btrfs_header_owner(upper->eb), + }; + btrfs_set_node_blockptr(upper->eb, slot, node->eb->start); btrfs_set_node_ptr_generation(upper->eb, slot, trans->transid); - btrfs_mark_buffer_dirty(upper->eb); - - ret = btrfs_inc_extent_ref(trans, root, - node->eb->start, blocksize, - upper->eb->start, - btrfs_header_owner(upper->eb), - node->level, 0, 1); - BUG_ON(ret); - - ret = btrfs_drop_subtree(trans, root, eb, upper->eb); - BUG_ON(ret); + btrfs_mark_buffer_dirty(trans, upper->eb); + + btrfs_init_tree_ref(&ref, node->level, + btrfs_root_id(root), false); + ret = btrfs_inc_extent_ref(trans, &ref); + if (!ret) + ret = btrfs_drop_subtree(trans, root, eb, + upper->eb); + if (unlikely(ret)) + btrfs_abort_transaction(trans, ret); } next: if (!upper->pending) - drop_node_buffer(upper); + btrfs_backref_drop_node_buffer(upper); else - unlock_node_buffer(upper); - if (err) + btrfs_backref_unlock_node_buffer(upper); + if (ret) break; } - if (!err && node->pending) { - drop_node_buffer(node); - list_move_tail(&node->list, &rc->backref_cache.changed); + if (!ret && node->pending) { + btrfs_backref_drop_node_buffer(node); + list_del_init(&node->list); node->pending = 0; } path->lowest_level = 0; - BUG_ON(err == -ENOSPC); - return err; + + /* + * We should have allocated all of our space in the block rsv and thus + * shouldn't ENOSPC. + */ + ASSERT(ret != -ENOSPC); + return ret; } static int link_to_upper(struct btrfs_trans_handle *trans, struct reloc_control *rc, - struct backref_node *node, + struct btrfs_backref_node *node, struct btrfs_path *path) { struct btrfs_key key; @@ -2722,15 +2361,15 @@ static int finish_pending_nodes(struct btrfs_trans_handle *trans, struct btrfs_path *path, int err) { LIST_HEAD(list); - struct backref_cache *cache = &rc->backref_cache; - struct backref_node *node; + struct btrfs_backref_cache *cache = &rc->backref_cache; + struct btrfs_backref_node *node; int level; int ret; for (level = 0; level < BTRFS_MAX_LEVEL; level++) { while (!list_empty(&cache->pending[level])) { - node = list_entry(cache->pending[level].next, - struct backref_node, list); + node = list_first_entry(&cache->pending[level], + struct btrfs_backref_node, list); list_move_tail(&node->list, &list); BUG_ON(!node->pending); @@ -2745,35 +2384,16 @@ static int finish_pending_nodes(struct btrfs_trans_handle *trans, return err; } -static void mark_block_processed(struct reloc_control *rc, - u64 bytenr, u32 blocksize) -{ - set_extent_bits(&rc->processed_blocks, bytenr, bytenr + blocksize - 1, - EXTENT_DIRTY, GFP_NOFS); -} - -static void __mark_block_processed(struct reloc_control *rc, - struct backref_node *node) -{ - u32 blocksize; - if (node->level == 0 || - in_block_group(node->bytenr, rc->block_group)) { - blocksize = btrfs_level_size(rc->extent_root, node->level); - mark_block_processed(rc, node->bytenr, blocksize); - } - node->processed = 1; -} - /* * mark a block and all blocks directly/indirectly reference the block * as processed. */ static void update_processed_blocks(struct reloc_control *rc, - struct backref_node *node) + struct btrfs_backref_node *node) { - struct backref_node *next = node; - struct backref_edge *edge; - struct backref_edge *edges[BTRFS_MAX_LEVEL - 1]; + struct btrfs_backref_node *next = node; + struct btrfs_backref_edge *edge; + struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1]; int index = 0; while (next) { @@ -2782,13 +2402,13 @@ static void update_processed_blocks(struct reloc_control *rc, if (next->processed) break; - __mark_block_processed(rc, next); + mark_block_processed(rc, next); if (list_empty(&next->upper)) break; - edge = list_entry(next->upper.next, - struct backref_edge, list[LOWER]); + edge = list_first_entry(&next->upper, struct btrfs_backref_edge, + list[LOWER]); edges[index++] = edge; next = edge->node[UPPER]; } @@ -2796,48 +2416,39 @@ static void update_processed_blocks(struct reloc_control *rc, } } -static int tree_block_processed(u64 bytenr, u32 blocksize, - struct reloc_control *rc) +static int tree_block_processed(u64 bytenr, struct reloc_control *rc) { - if (test_range_bit(&rc->processed_blocks, bytenr, - bytenr + blocksize - 1, EXTENT_DIRTY, 1, NULL)) + u32 blocksize = rc->extent_root->fs_info->nodesize; + + if (btrfs_test_range_bit(&rc->processed_blocks, bytenr, + bytenr + blocksize - 1, EXTENT_DIRTY, NULL)) return 1; return 0; } -static int get_tree_block_key(struct reloc_control *rc, +static int get_tree_block_key(struct btrfs_fs_info *fs_info, struct tree_block *block) { + struct btrfs_tree_parent_check check = { + .level = block->level, + .owner_root = block->owner, + .transid = block->key.offset + }; struct extent_buffer *eb; - BUG_ON(block->key_ready); - eb = read_tree_block(rc->extent_root, block->bytenr, - block->key.objectid, block->key.offset); - if (!eb || !extent_buffer_uptodate(eb)) { + eb = read_tree_block(fs_info, block->bytenr, &check); + if (IS_ERR(eb)) + return PTR_ERR(eb); + if (unlikely(!extent_buffer_uptodate(eb))) { free_extent_buffer(eb); return -EIO; } - WARN_ON(btrfs_header_level(eb) != block->level); if (block->level == 0) btrfs_item_key_to_cpu(eb, &block->key, 0); else btrfs_node_key_to_cpu(eb, &block->key, 0); free_extent_buffer(eb); - block->key_ready = 1; - return 0; -} - -static int reada_tree_block(struct reloc_control *rc, - struct tree_block *block) -{ - BUG_ON(block->key_ready); - if (block->key.type == BTRFS_METADATA_ITEM_KEY) - readahead_tree_block(rc->extent_root, block->bytenr, - block->key.objectid, - rc->extent_root->leafsize); - else - readahead_tree_block(rc->extent_root, block->bytenr, - block->key.objectid, block->key.offset); + block->key_ready = true; return 0; } @@ -2846,46 +2457,82 @@ static int reada_tree_block(struct reloc_control *rc, */ static int relocate_tree_block(struct btrfs_trans_handle *trans, struct reloc_control *rc, - struct backref_node *node, + struct btrfs_backref_node *node, struct btrfs_key *key, struct btrfs_path *path) { struct btrfs_root *root; - int release = 0; int ret = 0; if (!node) return 0; - BUG_ON(node->processed); - root = select_one_root(trans, node); - if (root == ERR_PTR(-ENOENT)) { - update_processed_blocks(rc, node); + /* + * If we fail here we want to drop our backref_node because we are going + * to start over and regenerate the tree for it. + */ + ret = reserve_metadata_space(trans, rc, node); + if (ret) goto out; - } - if (!root || root->ref_cows) { - ret = reserve_metadata_space(trans, rc, node); - if (ret) - goto out; - release = 1; + BUG_ON(node->processed); + root = select_one_root(node); + if (IS_ERR(root)) { + ret = PTR_ERR(root); + + /* See explanation in select_one_root for the -EUCLEAN case. */ + ASSERT(ret == -ENOENT); + if (ret == -ENOENT) { + ret = 0; + update_processed_blocks(rc, node); + } + goto out; } if (root) { - if (root->ref_cows) { - BUG_ON(node->new_bytenr); - BUG_ON(!list_empty(&node->list)); - btrfs_record_root_in_trans(trans, root); + if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { + /* + * This block was the root block of a root, and this is + * the first time we're processing the block and thus it + * should not have had the ->new_bytenr modified. + * + * However in the case of corruption we could have + * multiple refs pointing to the same block improperly, + * and thus we would trip over these checks. ASSERT() + * for the developer case, because it could indicate a + * bug in the backref code, however error out for a + * normal user in the case of corruption. + */ + ASSERT(node->new_bytenr == 0); + if (unlikely(node->new_bytenr)) { + btrfs_err(root->fs_info, + "bytenr %llu has improper references to it", + node->bytenr); + ret = -EUCLEAN; + goto out; + } + ret = btrfs_record_root_in_trans(trans, root); + if (ret) + goto out; + /* + * Another thread could have failed, need to check if we + * have reloc_root actually set. + */ + if (!root->reloc_root) { + ret = -ENOENT; + goto out; + } root = root->reloc_root; node->new_bytenr = root->node->start; - node->root = root; - list_add_tail(&node->list, &rc->backref_cache.changed); + btrfs_put_root(node->root); + node->root = btrfs_grab_root(root); + ASSERT(node->root); } else { - path->lowest_level = node->level; - ret = btrfs_search_slot(trans, root, key, path, 0, 1); - btrfs_release_path(path); - if (ret > 0) - ret = 0; + btrfs_err(root->fs_info, + "bytenr %llu resolved to a non-shareable root", + node->bytenr); + ret = -EUCLEAN; + goto out; } if (!ret) update_processed_blocks(rc, node); @@ -2893,11 +2540,47 @@ static int relocate_tree_block(struct btrfs_trans_handle *trans, ret = do_relocation(trans, rc, node, key, path, 1); } out: - if (ret || node->level == 0 || node->cowonly) { - if (release) - release_metadata_space(rc, node); - remove_backref_node(&rc->backref_cache, node); + if (ret || node->level == 0) + btrfs_backref_cleanup_node(&rc->backref_cache, node); + return ret; +} + +static int relocate_cowonly_block(struct btrfs_trans_handle *trans, + struct reloc_control *rc, struct tree_block *block, + struct btrfs_path *path) +{ + struct btrfs_fs_info *fs_info = trans->fs_info; + struct btrfs_root *root; + u64 num_bytes; + int nr_levels; + int ret; + + root = btrfs_get_fs_root(fs_info, block->owner, true); + if (IS_ERR(root)) + return PTR_ERR(root); + + nr_levels = max(btrfs_header_level(root->node) - block->level, 0) + 1; + + num_bytes = fs_info->nodesize * nr_levels; + ret = refill_metadata_space(trans, rc, num_bytes); + if (ret) { + btrfs_put_root(root); + return ret; } + path->lowest_level = block->level; + if (root == root->fs_info->chunk_root) + btrfs_reserve_chunk_metadata(trans, false); + + ret = btrfs_search_slot(trans, root, &block->key, path, 0, 1); + path->lowest_level = 0; + btrfs_release_path(path); + + if (root == root->fs_info->chunk_root) + btrfs_trans_release_chunk_metadata(trans); + if (ret > 0) + ret = 0; + btrfs_put_root(root); + return ret; } @@ -2908,268 +2591,432 @@ static noinline_for_stack int relocate_tree_blocks(struct btrfs_trans_handle *trans, struct reloc_control *rc, struct rb_root *blocks) { - struct backref_node *node; + struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; + struct btrfs_backref_node *node; struct btrfs_path *path; struct tree_block *block; - struct rb_node *rb_node; - int ret; - int err = 0; + struct tree_block *next; + int ret = 0; path = btrfs_alloc_path(); if (!path) { - err = -ENOMEM; + ret = -ENOMEM; goto out_free_blocks; } - rb_node = rb_first(blocks); - while (rb_node) { - block = rb_entry(rb_node, struct tree_block, rb_node); + /* Kick in readahead for tree blocks with missing keys */ + rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) { if (!block->key_ready) - reada_tree_block(rc, block); - rb_node = rb_next(rb_node); + btrfs_readahead_tree_block(fs_info, block->bytenr, + block->owner, 0, + block->level); } - rb_node = rb_first(blocks); - while (rb_node) { - block = rb_entry(rb_node, struct tree_block, rb_node); + /* Get first keys */ + rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) { if (!block->key_ready) { - err = get_tree_block_key(rc, block); - if (err) + ret = get_tree_block_key(fs_info, block); + if (ret) goto out_free_path; } - rb_node = rb_next(rb_node); } - rb_node = rb_first(blocks); - while (rb_node) { - block = rb_entry(rb_node, struct tree_block, rb_node); + /* Do tree relocation */ + rbtree_postorder_for_each_entry_safe(block, next, blocks, rb_node) { + /* + * For COWonly blocks, or the data reloc tree, we only need to + * COW down to the block, there's no need to generate a backref + * tree. + */ + if (block->owner && + (!btrfs_is_fstree(block->owner) || + block->owner == BTRFS_DATA_RELOC_TREE_OBJECTID)) { + ret = relocate_cowonly_block(trans, rc, block, path); + if (ret) + break; + continue; + } - node = build_backref_tree(rc, &block->key, + node = build_backref_tree(trans, rc, &block->key, block->level, block->bytenr); if (IS_ERR(node)) { - err = PTR_ERR(node); + ret = PTR_ERR(node); goto out; } ret = relocate_tree_block(trans, rc, node, &block->key, path); - if (ret < 0) { - if (ret != -EAGAIN || rb_node == rb_first(blocks)) - err = ret; - goto out; - } - rb_node = rb_next(rb_node); + if (ret < 0) + break; } out: - err = finish_pending_nodes(trans, rc, path, err); + ret = finish_pending_nodes(trans, rc, path, ret); out_free_path: btrfs_free_path(path); out_free_blocks: free_block_list(blocks); - return err; + return ret; } -static noinline_for_stack -int prealloc_file_extent_cluster(struct inode *inode, - struct file_extent_cluster *cluster) +static noinline_for_stack int prealloc_file_extent_cluster(struct reloc_control *rc) { + const struct file_extent_cluster *cluster = &rc->cluster; + struct btrfs_inode *inode = BTRFS_I(rc->data_inode); u64 alloc_hint = 0; u64 start; u64 end; - u64 offset = BTRFS_I(inode)->index_cnt; + u64 offset = inode->reloc_block_group_start; u64 num_bytes; - int nr = 0; + int nr; int ret = 0; + u64 prealloc_start = cluster->start - offset; + u64 prealloc_end = cluster->end - offset; + u64 cur_offset = prealloc_start; - BUG_ON(cluster->start != cluster->boundary[0]); - mutex_lock(&inode->i_mutex); + /* + * For blocksize < folio size case (either bs < page size or large folios), + * beyond i_size, all blocks are filled with zero. + * + * If the current cluster covers the above range, btrfs_do_readpage() + * will skip the read, and relocate_one_folio() will later writeback + * the padding zeros as new data, causing data corruption. + * + * Here we have to invalidate the cache covering our cluster. + */ + ret = filemap_invalidate_inode(&inode->vfs_inode, true, prealloc_start, + prealloc_end); + if (ret < 0) + return ret; - ret = btrfs_check_data_free_space(inode, cluster->end + - 1 - cluster->start); + BUG_ON(cluster->start != cluster->boundary[0]); + ret = btrfs_alloc_data_chunk_ondemand(inode, + prealloc_end + 1 - prealloc_start); if (ret) - goto out; + return ret; + + btrfs_inode_lock(inode, 0); + for (nr = 0; nr < cluster->nr; nr++) { + struct extent_state *cached_state = NULL; - while (nr < cluster->nr) { start = cluster->boundary[nr] - offset; if (nr + 1 < cluster->nr) end = cluster->boundary[nr + 1] - 1 - offset; else end = cluster->end - offset; - lock_extent(&BTRFS_I(inode)->io_tree, start, end); + btrfs_lock_extent(&inode->io_tree, start, end, &cached_state); num_bytes = end + 1 - start; - ret = btrfs_prealloc_file_range(inode, 0, start, + ret = btrfs_prealloc_file_range(&inode->vfs_inode, 0, start, num_bytes, num_bytes, end + 1, &alloc_hint); - unlock_extent(&BTRFS_I(inode)->io_tree, start, end); + cur_offset = end + 1; + btrfs_unlock_extent(&inode->io_tree, start, end, &cached_state); if (ret) break; - nr++; } - btrfs_free_reserved_data_space(inode, cluster->end + - 1 - cluster->start); -out: - mutex_unlock(&inode->i_mutex); + btrfs_inode_unlock(inode, 0); + + if (cur_offset < prealloc_end) + btrfs_free_reserved_data_space_noquota(inode, + prealloc_end + 1 - cur_offset); return ret; } -static noinline_for_stack -int setup_extent_mapping(struct inode *inode, u64 start, u64 end, - u64 block_start) +static noinline_for_stack int setup_relocation_extent_mapping(struct reloc_control *rc) { - struct btrfs_root *root = BTRFS_I(inode)->root; - struct extent_map_tree *em_tree = &BTRFS_I(inode)->extent_tree; + struct btrfs_inode *inode = BTRFS_I(rc->data_inode); struct extent_map *em; + struct extent_state *cached_state = NULL; + u64 offset = inode->reloc_block_group_start; + u64 start = rc->cluster.start - offset; + u64 end = rc->cluster.end - offset; int ret = 0; - em = alloc_extent_map(); + em = btrfs_alloc_extent_map(); if (!em) return -ENOMEM; em->start = start; em->len = end + 1 - start; - em->block_len = em->len; - em->block_start = block_start; - em->bdev = root->fs_info->fs_devices->latest_bdev; - set_bit(EXTENT_FLAG_PINNED, &em->flags); + em->disk_bytenr = rc->cluster.start; + em->disk_num_bytes = em->len; + em->ram_bytes = em->len; + em->flags |= EXTENT_FLAG_PINNED; + + btrfs_lock_extent(&inode->io_tree, start, end, &cached_state); + ret = btrfs_replace_extent_map_range(inode, em, false); + btrfs_unlock_extent(&inode->io_tree, start, end, &cached_state); + btrfs_free_extent_map(em); - lock_extent(&BTRFS_I(inode)->io_tree, start, end); - while (1) { - write_lock(&em_tree->lock); - ret = add_extent_mapping(em_tree, em, 0); - write_unlock(&em_tree->lock); - if (ret != -EEXIST) { - free_extent_map(em); - break; - } - btrfs_drop_extent_cache(inode, start, end, 0); - } - unlock_extent(&BTRFS_I(inode)->io_tree, start, end); return ret; } -static int relocate_file_extent_cluster(struct inode *inode, - struct file_extent_cluster *cluster) +/* + * Allow error injection to test balance/relocation cancellation + */ +noinline int btrfs_should_cancel_balance(const struct btrfs_fs_info *fs_info) { - u64 page_start; - u64 page_end; - u64 offset = BTRFS_I(inode)->index_cnt; - unsigned long index; - unsigned long last_index; - struct page *page; - struct file_ra_state *ra; - gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); - int nr = 0; - int ret = 0; + return atomic_read(&fs_info->balance_cancel_req) || + atomic_read(&fs_info->reloc_cancel_req) || + fatal_signal_pending(current); +} +ALLOW_ERROR_INJECTION(btrfs_should_cancel_balance, TRUE); - if (!cluster->nr) - return 0; +static u64 get_cluster_boundary_end(const struct file_extent_cluster *cluster, + int cluster_nr) +{ + /* Last extent, use cluster end directly */ + if (cluster_nr >= cluster->nr - 1) + return cluster->end; - ra = kzalloc(sizeof(*ra), GFP_NOFS); - if (!ra) - return -ENOMEM; + /* Use next boundary start*/ + return cluster->boundary[cluster_nr + 1] - 1; +} - ret = prealloc_file_extent_cluster(inode, cluster); - if (ret) - goto out; +static int relocate_one_folio(struct reloc_control *rc, + struct file_ra_state *ra, + int *cluster_nr, u64 *file_offset_ret) +{ + const struct file_extent_cluster *cluster = &rc->cluster; + struct inode *inode = rc->data_inode; + struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); + const u64 orig_file_offset = *file_offset_ret; + u64 offset = BTRFS_I(inode)->reloc_block_group_start; + const pgoff_t last_index = (cluster->end - offset) >> PAGE_SHIFT; + const pgoff_t index = orig_file_offset >> PAGE_SHIFT; + gfp_t mask = btrfs_alloc_write_mask(inode->i_mapping); + struct folio *folio; + u64 folio_start; + u64 folio_end; + u64 cur; + int ret; + const bool use_rst = btrfs_need_stripe_tree_update(fs_info, rc->block_group->flags); - file_ra_state_init(ra, inode->i_mapping); + ASSERT(index <= last_index); +again: + folio = filemap_lock_folio(inode->i_mapping, index); + if (IS_ERR(folio)) { - ret = setup_extent_mapping(inode, cluster->start - offset, - cluster->end - offset, cluster->start); - if (ret) - goto out; + /* + * On relocation we're doing readahead on the relocation inode, + * but if the filesystem is backed by a RAID stripe tree we can + * get ENOENT (e.g. due to preallocated extents not being + * mapped in the RST) from the lookup. + * + * But readahead doesn't handle the error and submits invalid + * reads to the device, causing a assertion failures. + */ + if (!use_rst) + page_cache_sync_readahead(inode->i_mapping, ra, NULL, + index, last_index + 1 - index); + folio = __filemap_get_folio(inode->i_mapping, index, + FGP_LOCK | FGP_ACCESSED | FGP_CREAT, + mask); + if (IS_ERR(folio)) + return PTR_ERR(folio); + } + + if (folio_test_readahead(folio) && !use_rst) + page_cache_async_readahead(inode->i_mapping, ra, NULL, + folio, last_index + 1 - index); + + if (!folio_test_uptodate(folio)) { + btrfs_read_folio(NULL, folio); + folio_lock(folio); + if (unlikely(!folio_test_uptodate(folio))) { + ret = -EIO; + goto release_folio; + } + if (folio->mapping != inode->i_mapping) { + folio_unlock(folio); + folio_put(folio); + goto again; + } + } - index = (cluster->start - offset) >> PAGE_CACHE_SHIFT; - last_index = (cluster->end - offset) >> PAGE_CACHE_SHIFT; - while (index <= last_index) { - ret = btrfs_delalloc_reserve_metadata(inode, PAGE_CACHE_SIZE); + /* + * We could have lost folio private when we dropped the lock to read the + * folio above, make sure we set_folio_extent_mapped() here so we have any + * of the subpage blocksize stuff we need in place. + */ + ret = set_folio_extent_mapped(folio); + if (ret < 0) + goto release_folio; + + folio_start = folio_pos(folio); + folio_end = folio_start + folio_size(folio) - 1; + + /* + * Start from the cluster, as for subpage case, the cluster can start + * inside the folio. + */ + cur = max(folio_start, cluster->boundary[*cluster_nr] - offset); + while (cur <= folio_end) { + struct extent_state *cached_state = NULL; + u64 extent_start = cluster->boundary[*cluster_nr] - offset; + u64 extent_end = get_cluster_boundary_end(cluster, + *cluster_nr) - offset; + u64 clamped_start = max(folio_start, extent_start); + u64 clamped_end = min(folio_end, extent_end); + u32 clamped_len = clamped_end + 1 - clamped_start; + + /* Reserve metadata for this range */ + ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), + clamped_len, clamped_len, + false); if (ret) - goto out; + goto release_folio; - page = find_lock_page(inode->i_mapping, index); - if (!page) { - page_cache_sync_readahead(inode->i_mapping, - ra, NULL, index, - last_index + 1 - index); - page = find_or_create_page(inode->i_mapping, index, - mask); - if (!page) { - btrfs_delalloc_release_metadata(inode, - PAGE_CACHE_SIZE); - ret = -ENOMEM; - goto out; - } + /* Mark the range delalloc and dirty for later writeback */ + btrfs_lock_extent(&BTRFS_I(inode)->io_tree, clamped_start, + clamped_end, &cached_state); + ret = btrfs_set_extent_delalloc(BTRFS_I(inode), clamped_start, + clamped_end, 0, &cached_state); + if (ret) { + btrfs_clear_extent_bit(&BTRFS_I(inode)->io_tree, + clamped_start, clamped_end, + EXTENT_LOCKED | EXTENT_BOUNDARY, + &cached_state); + btrfs_delalloc_release_metadata(BTRFS_I(inode), + clamped_len, true); + btrfs_delalloc_release_extents(BTRFS_I(inode), + clamped_len); + goto release_folio; } + btrfs_folio_set_dirty(fs_info, folio, clamped_start, clamped_len); - if (PageReadahead(page)) { - page_cache_async_readahead(inode->i_mapping, - ra, NULL, page, index, - last_index + 1 - index); + /* + * Set the boundary if it's inside the folio. + * Data relocation requires the destination extents to have the + * same size as the source. + * EXTENT_BOUNDARY bit prevents current extent from being merged + * with previous extent. + */ + if (in_range(cluster->boundary[*cluster_nr] - offset, + folio_start, folio_size(folio))) { + u64 boundary_start = cluster->boundary[*cluster_nr] - + offset; + u64 boundary_end = boundary_start + + fs_info->sectorsize - 1; + + btrfs_set_extent_bit(&BTRFS_I(inode)->io_tree, + boundary_start, boundary_end, + EXTENT_BOUNDARY, NULL); } - - if (!PageUptodate(page)) { - btrfs_readpage(NULL, page); - lock_page(page); - if (!PageUptodate(page)) { - unlock_page(page); - page_cache_release(page); - btrfs_delalloc_release_metadata(inode, - PAGE_CACHE_SIZE); - ret = -EIO; - goto out; - } + btrfs_unlock_extent(&BTRFS_I(inode)->io_tree, clamped_start, clamped_end, + &cached_state); + btrfs_delalloc_release_extents(BTRFS_I(inode), clamped_len); + cur += clamped_len; + + /* Crossed extent end, go to next extent */ + if (cur >= extent_end) { + (*cluster_nr)++; + /* Just finished the last extent of the cluster, exit. */ + if (*cluster_nr >= cluster->nr) + break; } + } + folio_unlock(folio); + folio_put(folio); - page_start = page_offset(page); - page_end = page_start + PAGE_CACHE_SIZE - 1; + balance_dirty_pages_ratelimited(inode->i_mapping); + btrfs_throttle(fs_info); + if (btrfs_should_cancel_balance(fs_info)) + ret = -ECANCELED; + *file_offset_ret = folio_end + 1; + return ret; - lock_extent(&BTRFS_I(inode)->io_tree, page_start, page_end); +release_folio: + folio_unlock(folio); + folio_put(folio); + return ret; +} - set_page_extent_mapped(page); +static int relocate_file_extent_cluster(struct reloc_control *rc) +{ + struct inode *inode = rc->data_inode; + const struct file_extent_cluster *cluster = &rc->cluster; + u64 offset = BTRFS_I(inode)->reloc_block_group_start; + u64 cur_file_offset = cluster->start - offset; + struct file_ra_state AUTO_KFREE(ra); + int cluster_nr = 0; + int ret = 0; - if (nr < cluster->nr && - page_start + offset == cluster->boundary[nr]) { - set_extent_bits(&BTRFS_I(inode)->io_tree, - page_start, page_end, - EXTENT_BOUNDARY, GFP_NOFS); - nr++; - } + if (!cluster->nr) + return 0; + + ra = kzalloc(sizeof(*ra), GFP_NOFS); + if (!ra) + return -ENOMEM; - btrfs_set_extent_delalloc(inode, page_start, page_end, NULL); - set_page_dirty(page); + ret = prealloc_file_extent_cluster(rc); + if (ret) + return ret; + + file_ra_state_init(ra, inode->i_mapping); - unlock_extent(&BTRFS_I(inode)->io_tree, - page_start, page_end); - unlock_page(page); - page_cache_release(page); + ret = setup_relocation_extent_mapping(rc); + if (ret) + return ret; - index++; - balance_dirty_pages_ratelimited(inode->i_mapping); - btrfs_throttle(BTRFS_I(inode)->root); + while (cur_file_offset < cluster->end - offset) { + ret = relocate_one_folio(rc, ra, &cluster_nr, &cur_file_offset); + if (ret) + break; } - WARN_ON(nr != cluster->nr); -out: - kfree(ra); + if (ret == 0) + WARN_ON(cluster_nr != cluster->nr); return ret; } -static noinline_for_stack -int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key, - struct file_extent_cluster *cluster) +static noinline_for_stack int relocate_data_extent(struct reloc_control *rc, + const struct btrfs_key *extent_key) { + struct inode *inode = rc->data_inode; + struct file_extent_cluster *cluster = &rc->cluster; int ret; + struct btrfs_root *root = BTRFS_I(inode)->root; if (cluster->nr > 0 && extent_key->objectid != cluster->end + 1) { - ret = relocate_file_extent_cluster(inode, cluster); + ret = relocate_file_extent_cluster(rc); if (ret) return ret; cluster->nr = 0; } - if (!cluster->nr) + /* + * Under simple quotas, we set root->relocation_src_root when we find + * the extent. If adjacent extents have different owners, we can't merge + * them while relocating. Handle this by storing the owning root that + * started a cluster and if we see an extent from a different root break + * cluster formation (just like the above case of non-adjacent extents). + * + * Without simple quotas, relocation_src_root is always 0, so we should + * never see a mismatch, and it should have no effect on relocation + * clusters. + */ + if (cluster->nr > 0 && cluster->owning_root != root->relocation_src_root) { + u64 tmp = root->relocation_src_root; + + /* + * root->relocation_src_root is the state that actually affects + * the preallocation we do here, so set it to the root owning + * the cluster we need to relocate. + */ + root->relocation_src_root = cluster->owning_root; + ret = relocate_file_extent_cluster(rc); + if (ret) + return ret; + cluster->nr = 0; + /* And reset it back for the current extent's owning root. */ + root->relocation_src_root = tmp; + } + + if (!cluster->nr) { cluster->start = extent_key->objectid; + cluster->owning_root = root->relocation_src_root; + } else BUG_ON(cluster->nr >= MAX_EXTENTS); cluster->end = extent_key->objectid + extent_key->offset - 1; @@ -3177,7 +3024,7 @@ int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key, cluster->nr++; if (cluster->nr >= MAX_EXTENTS) { - ret = relocate_file_extent_cluster(inode, cluster); + ret = relocate_file_extent_cluster(rc); if (ret) return ret; cluster->nr = 0; @@ -3185,54 +3032,12 @@ int relocate_data_extent(struct inode *inode, struct btrfs_key *extent_key, return 0; } -#ifdef BTRFS_COMPAT_EXTENT_TREE_V0 -static int get_ref_objectid_v0(struct reloc_control *rc, - struct btrfs_path *path, - struct btrfs_key *extent_key, - u64 *ref_objectid, int *path_change) -{ - struct btrfs_key key; - struct extent_buffer *leaf; - struct btrfs_extent_ref_v0 *ref0; - int ret; - int slot; - - leaf = path->nodes[0]; - slot = path->slots[0]; - while (1) { - if (slot >= btrfs_header_nritems(leaf)) { - ret = btrfs_next_leaf(rc->extent_root, path); - if (ret < 0) - return ret; - BUG_ON(ret > 0); - leaf = path->nodes[0]; - slot = path->slots[0]; - if (path_change) - *path_change = 1; - } - btrfs_item_key_to_cpu(leaf, &key, slot); - if (key.objectid != extent_key->objectid) - return -ENOENT; - - if (key.type != BTRFS_EXTENT_REF_V0_KEY) { - slot++; - continue; - } - ref0 = btrfs_item_ptr(leaf, slot, - struct btrfs_extent_ref_v0); - *ref_objectid = btrfs_ref_objectid_v0(leaf, ref0); - break; - } - return 0; -} -#endif - /* * helper to add a tree block to the list. * the major work is getting the generation and level of the block */ static int add_tree_block(struct reloc_control *rc, - struct btrfs_key *extent_key, + const struct btrfs_key *extent_key, struct btrfs_path *path, struct rb_root *blocks) { @@ -3243,39 +3048,66 @@ static int add_tree_block(struct reloc_control *rc, struct rb_node *rb_node; u32 item_size; int level = -1; - int generation; + u64 generation; + u64 owner = 0; eb = path->nodes[0]; - item_size = btrfs_item_size_nr(eb, path->slots[0]); + item_size = btrfs_item_size(eb, path->slots[0]); if (extent_key->type == BTRFS_METADATA_ITEM_KEY || item_size >= sizeof(*ei) + sizeof(*bi)) { + unsigned long ptr = 0, end; + ei = btrfs_item_ptr(eb, path->slots[0], struct btrfs_extent_item); + end = (unsigned long)ei + item_size; if (extent_key->type == BTRFS_EXTENT_ITEM_KEY) { bi = (struct btrfs_tree_block_info *)(ei + 1); level = btrfs_tree_block_level(eb, bi); + ptr = (unsigned long)(bi + 1); } else { level = (int)extent_key->offset; + ptr = (unsigned long)(ei + 1); } generation = btrfs_extent_generation(eb, ei); - } else { -#ifdef BTRFS_COMPAT_EXTENT_TREE_V0 - u64 ref_owner; - int ret; - BUG_ON(item_size != sizeof(struct btrfs_extent_item_v0)); - ret = get_ref_objectid_v0(rc, path, extent_key, - &ref_owner, NULL); - if (ret < 0) - return ret; - BUG_ON(ref_owner >= BTRFS_MAX_LEVEL); - level = (int)ref_owner; - /* FIXME: get real generation */ - generation = 0; -#else - BUG(); -#endif + /* + * We're reading random blocks without knowing their owner ahead + * of time. This is ok most of the time, as all reloc roots and + * fs roots have the same lock type. However normal trees do + * not, and the only way to know ahead of time is to read the + * inline ref offset. We know it's an fs root if + * + * 1. There's more than one ref. + * 2. There's a SHARED_DATA_REF_KEY set. + * 3. FULL_BACKREF is set on the flags. + * + * Otherwise it's safe to assume that the ref offset == the + * owner of this block, so we can use that when calling + * read_tree_block. + */ + if (btrfs_extent_refs(eb, ei) == 1 && + !(btrfs_extent_flags(eb, ei) & + BTRFS_BLOCK_FLAG_FULL_BACKREF) && + ptr < end) { + struct btrfs_extent_inline_ref *iref; + int type; + + iref = (struct btrfs_extent_inline_ref *)ptr; + type = btrfs_get_extent_inline_ref_type(eb, iref, + BTRFS_REF_TYPE_BLOCK); + if (type == BTRFS_REF_TYPE_INVALID) + return -EINVAL; + if (type == BTRFS_TREE_BLOCK_REF_KEY) + owner = btrfs_extent_inline_ref_offset(eb, iref); + } + } else { + btrfs_print_leaf(eb); + btrfs_err(rc->block_group->fs_info, + "unrecognized tree backref at tree block %llu slot %u", + eb->start, path->slots[0]); + btrfs_release_path(path); + return -EUCLEAN; } btrfs_release_path(path); @@ -3287,14 +3119,16 @@ static int add_tree_block(struct reloc_control *rc, return -ENOMEM; block->bytenr = extent_key->objectid; - block->key.objectid = rc->extent_root->leafsize; + block->key.objectid = rc->extent_root->fs_info->nodesize; block->key.offset = generation; block->level = level; - block->key_ready = 0; + block->key_ready = false; + block->owner = owner; - rb_node = tree_insert(blocks, block->bytenr, &block->rb_node); + rb_node = rb_simple_insert(blocks, &block->simple_node); if (rb_node) - backref_tree_panic(rb_node, -EEXIST, block->bytenr); + btrfs_backref_panic(rc->extent_root->fs_info, block->bytenr, + -EEXIST); return 0; } @@ -3306,16 +3140,16 @@ static int __add_tree_block(struct reloc_control *rc, u64 bytenr, u32 blocksize, struct rb_root *blocks) { - struct btrfs_path *path; + struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; + BTRFS_PATH_AUTO_FREE(path); struct btrfs_key key; int ret; - bool skinny = btrfs_fs_incompat(rc->extent_root->fs_info, - SKINNY_METADATA); + bool skinny = btrfs_fs_incompat(fs_info, SKINNY_METADATA); - if (tree_block_processed(bytenr, blocksize, rc)) + if (tree_block_processed(bytenr, rc)) return 0; - if (tree_search(blocks, bytenr)) + if (rb_simple_search(blocks, bytenr)) return 0; path = btrfs_alloc_path(); @@ -3331,11 +3165,11 @@ again: key.offset = blocksize; } - path->search_commit_root = 1; - path->skip_locking = 1; + path->search_commit_root = true; + path->skip_locking = true; ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0); if (ret < 0) - goto out; + return ret; if (ret > 0 && skinny) { if (path->slots[0]) { @@ -3355,372 +3189,165 @@ again: goto again; } } - BUG_ON(ret); - - ret = add_tree_block(rc, &key, path, blocks); -out: - btrfs_free_path(path); - return ret; -} - -/* - * helper to check if the block use full backrefs for pointers in it - */ -static int block_use_full_backref(struct reloc_control *rc, - struct extent_buffer *eb) -{ - u64 flags; - int ret; - - if (btrfs_header_flag(eb, BTRFS_HEADER_FLAG_RELOC) || - btrfs_header_backref_rev(eb) < BTRFS_MIXED_BACKREF_REV) - return 1; - - ret = btrfs_lookup_extent_info(NULL, rc->extent_root, - eb->start, btrfs_header_level(eb), 1, - NULL, &flags); - BUG_ON(ret); + if (ret) { + ASSERT(ret == 1); + btrfs_print_leaf(path->nodes[0]); + btrfs_err(fs_info, + "tree block extent item (%llu) is not found in extent tree", + bytenr); + WARN_ON(1); + return -EINVAL; + } - if (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF) - ret = 1; - else - ret = 0; - return ret; + return add_tree_block(rc, &key, path, blocks); } -static int delete_block_group_cache(struct btrfs_fs_info *fs_info, - struct inode *inode, u64 ino) +static int delete_block_group_cache(struct btrfs_block_group *block_group, + struct inode *inode, + u64 ino) { - struct btrfs_key key; - struct btrfs_path *path; + struct btrfs_fs_info *fs_info = block_group->fs_info; struct btrfs_root *root = fs_info->tree_root; struct btrfs_trans_handle *trans; + struct btrfs_inode *btrfs_inode; int ret = 0; if (inode) goto truncate; - key.objectid = ino; - key.type = BTRFS_INODE_ITEM_KEY; - key.offset = 0; - - inode = btrfs_iget(fs_info->sb, &key, root, NULL); - if (IS_ERR(inode) || is_bad_inode(inode)) { - if (!IS_ERR(inode)) - iput(inode); + btrfs_inode = btrfs_iget(ino, root); + if (IS_ERR(btrfs_inode)) return -ENOENT; - } + inode = &btrfs_inode->vfs_inode; truncate: - ret = btrfs_check_trunc_cache_free_space(root, + ret = btrfs_check_trunc_cache_free_space(fs_info, &fs_info->global_block_rsv); if (ret) goto out; - path = btrfs_alloc_path(); - if (!path) { - ret = -ENOMEM; - goto out; - } - trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { - btrfs_free_path(path); ret = PTR_ERR(trans); goto out; } - ret = btrfs_truncate_free_space_cache(root, trans, path, inode); + ret = btrfs_truncate_free_space_cache(trans, block_group, inode); - btrfs_free_path(path); - btrfs_end_transaction(trans, root); - btrfs_btree_balance_dirty(root); + btrfs_end_transaction(trans); + btrfs_btree_balance_dirty(fs_info); out: iput(inode); return ret; } /* - * helper to add tree blocks for backref of type BTRFS_EXTENT_DATA_REF_KEY - * this function scans fs tree to find blocks reference the data extent + * Locate the free space cache EXTENT_DATA in root tree leaf and delete the + * cache inode, to avoid free space cache data extent blocking data relocation. */ -static int find_data_references(struct reloc_control *rc, - struct btrfs_key *extent_key, - struct extent_buffer *leaf, - struct btrfs_extent_data_ref *ref, - struct rb_root *blocks) +static int delete_v1_space_cache(struct extent_buffer *leaf, + struct btrfs_block_group *block_group, + u64 data_bytenr) { - struct btrfs_path *path; - struct tree_block *block; - struct btrfs_root *root; - struct btrfs_file_extent_item *fi; - struct rb_node *rb_node; + u64 space_cache_ino; + struct btrfs_file_extent_item *ei; struct btrfs_key key; - u64 ref_root; - u64 ref_objectid; - u64 ref_offset; - u32 ref_count; - u32 nritems; - int err = 0; - int added = 0; - int counted; + bool found = false; + int i; int ret; - ref_root = btrfs_extent_data_ref_root(leaf, ref); - ref_objectid = btrfs_extent_data_ref_objectid(leaf, ref); - ref_offset = btrfs_extent_data_ref_offset(leaf, ref); - ref_count = btrfs_extent_data_ref_count(leaf, ref); - - /* - * This is an extent belonging to the free space cache, lets just delete - * it and redo the search. - */ - if (ref_root == BTRFS_ROOT_TREE_OBJECTID) { - ret = delete_block_group_cache(rc->extent_root->fs_info, - NULL, ref_objectid); - if (ret != -ENOENT) - return ret; - ret = 0; - } - - path = btrfs_alloc_path(); - if (!path) - return -ENOMEM; - path->reada = 1; - - root = read_fs_root(rc->extent_root->fs_info, ref_root); - if (IS_ERR(root)) { - err = PTR_ERR(root); - goto out; - } - - key.objectid = ref_objectid; - key.type = BTRFS_EXTENT_DATA_KEY; - if (ref_offset > ((u64)-1 << 32)) - key.offset = 0; - else - key.offset = ref_offset; - - path->search_commit_root = 1; - path->skip_locking = 1; - ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); - if (ret < 0) { - err = ret; - goto out; - } - - leaf = path->nodes[0]; - nritems = btrfs_header_nritems(leaf); - /* - * the references in tree blocks that use full backrefs - * are not counted in - */ - if (block_use_full_backref(rc, leaf)) - counted = 0; - else - counted = 1; - rb_node = tree_search(blocks, leaf->start); - if (rb_node) { - if (counted) - added = 1; - else - path->slots[0] = nritems; - } - - while (ref_count > 0) { - while (path->slots[0] >= nritems) { - ret = btrfs_next_leaf(root, path); - if (ret < 0) { - err = ret; - goto out; - } - if (ret > 0) { - WARN_ON(1); - goto out; - } - - leaf = path->nodes[0]; - nritems = btrfs_header_nritems(leaf); - added = 0; + if (btrfs_header_owner(leaf) != BTRFS_ROOT_TREE_OBJECTID) + return 0; - if (block_use_full_backref(rc, leaf)) - counted = 0; - else - counted = 1; - rb_node = tree_search(blocks, leaf->start); - if (rb_node) { - if (counted) - added = 1; - else - path->slots[0] = nritems; - } - } + for (i = 0; i < btrfs_header_nritems(leaf); i++) { + u8 type; - btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); - if (key.objectid != ref_objectid || - key.type != BTRFS_EXTENT_DATA_KEY) { - WARN_ON(1); + btrfs_item_key_to_cpu(leaf, &key, i); + if (key.type != BTRFS_EXTENT_DATA_KEY) + continue; + ei = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); + type = btrfs_file_extent_type(leaf, ei); + + if ((type == BTRFS_FILE_EXTENT_REG || + type == BTRFS_FILE_EXTENT_PREALLOC) && + btrfs_file_extent_disk_bytenr(leaf, ei) == data_bytenr) { + found = true; + space_cache_ino = key.objectid; break; } - - fi = btrfs_item_ptr(leaf, path->slots[0], - struct btrfs_file_extent_item); - - if (btrfs_file_extent_type(leaf, fi) == - BTRFS_FILE_EXTENT_INLINE) - goto next; - - if (btrfs_file_extent_disk_bytenr(leaf, fi) != - extent_key->objectid) - goto next; - - key.offset -= btrfs_file_extent_offset(leaf, fi); - if (key.offset != ref_offset) - goto next; - - if (counted) - ref_count--; - if (added) - goto next; - - if (!tree_block_processed(leaf->start, leaf->len, rc)) { - block = kmalloc(sizeof(*block), GFP_NOFS); - if (!block) { - err = -ENOMEM; - break; - } - block->bytenr = leaf->start; - btrfs_item_key_to_cpu(leaf, &block->key, 0); - block->level = 0; - block->key_ready = 1; - rb_node = tree_insert(blocks, block->bytenr, - &block->rb_node); - if (rb_node) - backref_tree_panic(rb_node, -EEXIST, - block->bytenr); - } - if (counted) - added = 1; - else - path->slots[0] = nritems; -next: - path->slots[0]++; - } -out: - btrfs_free_path(path); - return err; + if (!found) + return -ENOENT; + ret = delete_block_group_cache(block_group, NULL, space_cache_ino); + return ret; } /* * helper to find all tree blocks that reference a given data extent */ -static noinline_for_stack -int add_data_references(struct reloc_control *rc, - struct btrfs_key *extent_key, - struct btrfs_path *path, - struct rb_root *blocks) +static noinline_for_stack int add_data_references(struct reloc_control *rc, + const struct btrfs_key *extent_key, + struct btrfs_path *path, + struct rb_root *blocks) { - struct btrfs_key key; - struct extent_buffer *eb; - struct btrfs_extent_data_ref *dref; - struct btrfs_extent_inline_ref *iref; - unsigned long ptr; - unsigned long end; - u32 blocksize = btrfs_level_size(rc->extent_root, 0); - int ret; - int err = 0; + struct btrfs_backref_walk_ctx ctx = { 0 }; + struct ulist_iterator leaf_uiter; + struct ulist_node *ref_node = NULL; + const u32 blocksize = rc->extent_root->fs_info->nodesize; + int ret = 0; - eb = path->nodes[0]; - ptr = btrfs_item_ptr_offset(eb, path->slots[0]); - end = ptr + btrfs_item_size_nr(eb, path->slots[0]); -#ifdef BTRFS_COMPAT_EXTENT_TREE_V0 - if (ptr + sizeof(struct btrfs_extent_item_v0) == end) - ptr = end; - else -#endif - ptr += sizeof(struct btrfs_extent_item); - - while (ptr < end) { - iref = (struct btrfs_extent_inline_ref *)ptr; - key.type = btrfs_extent_inline_ref_type(eb, iref); - if (key.type == BTRFS_SHARED_DATA_REF_KEY) { - key.offset = btrfs_extent_inline_ref_offset(eb, iref); - ret = __add_tree_block(rc, key.offset, blocksize, - blocks); - } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { - dref = (struct btrfs_extent_data_ref *)(&iref->offset); - ret = find_data_references(rc, extent_key, - eb, dref, blocks); - } else { - BUG(); - } - ptr += btrfs_extent_inline_ref_size(key.type); - } - WARN_ON(ptr > end); + btrfs_release_path(path); - while (1) { - cond_resched(); - eb = path->nodes[0]; - if (path->slots[0] >= btrfs_header_nritems(eb)) { - ret = btrfs_next_leaf(rc->extent_root, path); - if (ret < 0) { - err = ret; - break; - } - if (ret > 0) - break; - eb = path->nodes[0]; - } + ctx.bytenr = extent_key->objectid; + ctx.skip_inode_ref_list = true; + ctx.fs_info = rc->extent_root->fs_info; - btrfs_item_key_to_cpu(eb, &key, path->slots[0]); - if (key.objectid != extent_key->objectid) - break; + ret = btrfs_find_all_leafs(&ctx); + if (ret < 0) + return ret; -#ifdef BTRFS_COMPAT_EXTENT_TREE_V0 - if (key.type == BTRFS_SHARED_DATA_REF_KEY || - key.type == BTRFS_EXTENT_REF_V0_KEY) { -#else - BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY); - if (key.type == BTRFS_SHARED_DATA_REF_KEY) { -#endif - ret = __add_tree_block(rc, key.offset, blocksize, - blocks); - } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { - dref = btrfs_item_ptr(eb, path->slots[0], - struct btrfs_extent_data_ref); - ret = find_data_references(rc, extent_key, - eb, dref, blocks); - } else { - ret = 0; - } - if (ret) { - err = ret; + ULIST_ITER_INIT(&leaf_uiter); + while ((ref_node = ulist_next(ctx.refs, &leaf_uiter))) { + struct btrfs_tree_parent_check check = { 0 }; + struct extent_buffer *eb; + + eb = read_tree_block(ctx.fs_info, ref_node->val, &check); + if (IS_ERR(eb)) { + ret = PTR_ERR(eb); break; } - path->slots[0]++; + ret = delete_v1_space_cache(eb, rc->block_group, + extent_key->objectid); + free_extent_buffer(eb); + if (ret < 0) + break; + ret = __add_tree_block(rc, ref_node->val, blocksize, blocks); + if (ret < 0) + break; } - btrfs_release_path(path); - if (err) + if (ret < 0) free_block_list(blocks); - return err; + ulist_free(ctx.refs); + return ret; } /* * helper to find next unprocessed extent */ static noinline_for_stack -int find_next_extent(struct btrfs_trans_handle *trans, - struct reloc_control *rc, struct btrfs_path *path, +int find_next_extent(struct reloc_control *rc, struct btrfs_path *path, struct btrfs_key *extent_key) { + struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; struct btrfs_key key; struct extent_buffer *leaf; u64 start, end, last; int ret; - last = rc->block_group->key.objectid + rc->block_group->key.offset; + last = rc->block_group->start + rc->block_group->length; while (1) { + bool block_found; + cond_resched(); if (rc->search_start >= last) { ret = 1; @@ -3731,8 +3358,8 @@ int find_next_extent(struct btrfs_trans_handle *trans, key.type = BTRFS_EXTENT_ITEM_KEY; key.offset = 0; - path->search_commit_root = 1; - path->skip_locking = 1; + path->search_commit_root = true; + path->skip_locking = true; ret = btrfs_search_slot(NULL, rc->extent_root, &key, path, 0, 0); if (ret < 0) @@ -3765,17 +3392,17 @@ next: } if (key.type == BTRFS_METADATA_ITEM_KEY && - key.objectid + rc->extent_root->leafsize <= + key.objectid + fs_info->nodesize <= rc->search_start) { path->slots[0]++; goto next; } - ret = find_first_extent_bit(&rc->processed_blocks, - key.objectid, &start, &end, - EXTENT_DIRTY, NULL); + block_found = btrfs_find_first_extent_bit(&rc->processed_blocks, + key.objectid, &start, &end, + EXTENT_DIRTY, NULL); - if (ret == 0 && start <= key.objectid) { + if (block_found && start <= key.objectid) { btrfs_release_path(path); rc->search_start = end + 1; } else { @@ -3783,7 +3410,7 @@ next: rc->search_start = key.objectid + key.offset; else rc->search_start = key.objectid + - rc->extent_root->leafsize; + fs_info->nodesize; memcpy(extent_key, &key, sizeof(key)); return 0; } @@ -3810,49 +3437,32 @@ static void unset_reloc_control(struct reloc_control *rc) mutex_unlock(&fs_info->reloc_mutex); } -static int check_extent_flags(u64 flags) -{ - if ((flags & BTRFS_EXTENT_FLAG_DATA) && - (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) - return 1; - if (!(flags & BTRFS_EXTENT_FLAG_DATA) && - !(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)) - return 1; - if ((flags & BTRFS_EXTENT_FLAG_DATA) && - (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) - return 1; - return 0; -} - static noinline_for_stack int prepare_to_relocate(struct reloc_control *rc) { struct btrfs_trans_handle *trans; int ret; - rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root, + rc->block_rsv = btrfs_alloc_block_rsv(rc->extent_root->fs_info, BTRFS_BLOCK_RSV_TEMP); if (!rc->block_rsv) return -ENOMEM; - /* - * reserve some space for creating reloc trees. - * btrfs_init_reloc_root will use them when there - * is no reservation in transaction handle. - */ - ret = btrfs_block_rsv_add(rc->extent_root, rc->block_rsv, - rc->extent_root->nodesize * 256, - BTRFS_RESERVE_FLUSH_ALL); - if (ret) - return ret; - memset(&rc->cluster, 0, sizeof(rc->cluster)); - rc->search_start = rc->block_group->key.objectid; + rc->search_start = rc->block_group->start; rc->extents_found = 0; rc->nodes_relocated = 0; rc->merging_rsv_size = 0; + rc->reserved_bytes = 0; + rc->block_rsv->size = rc->extent_root->fs_info->nodesize * + RELOCATION_RESERVED_NODES; + ret = btrfs_block_rsv_refill(rc->extent_root->fs_info, + rc->block_rsv, rc->block_rsv->size, + BTRFS_RESERVE_FLUSH_ALL); + if (ret) + return ret; - rc->create_reloc_tree = 1; + rc->create_reloc_tree = true; set_reloc_control(rc); trans = btrfs_join_transaction(rc->extent_root); @@ -3865,19 +3475,23 @@ int prepare_to_relocate(struct reloc_control *rc) */ return PTR_ERR(trans); } - btrfs_commit_transaction(trans, rc->extent_root); - return 0; + + ret = btrfs_commit_transaction(trans); + if (ret) + unset_reloc_control(rc); + + return ret; } static noinline_for_stack int relocate_block_group(struct reloc_control *rc) { + struct btrfs_fs_info *fs_info = rc->extent_root->fs_info; struct rb_root blocks = RB_ROOT; struct btrfs_key key; struct btrfs_trans_handle *trans = NULL; - struct btrfs_path *path; + BTRFS_PATH_AUTO_FREE(path); struct btrfs_extent_item *ei; u64 flags; - u32 item_size; int ret; int err = 0; int progress = 0; @@ -3885,7 +3499,7 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc) path = btrfs_alloc_path(); if (!path) return -ENOMEM; - path->reada = 1; + path->reada = READA_FORWARD; ret = prepare_to_relocate(rc); if (ret) { @@ -3894,6 +3508,14 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc) } while (1) { + rc->reserved_bytes = 0; + ret = btrfs_block_rsv_refill(fs_info, rc->block_rsv, + rc->block_rsv->size, + BTRFS_RESERVE_FLUSH_ALL); + if (ret) { + err = ret; + break; + } progress++; trans = btrfs_start_transaction(rc->extent_root, 0); if (IS_ERR(trans)) { @@ -3902,12 +3524,11 @@ static noinline_for_stack int relocate_block_group(struct reloc_control *rc) break; } restart: - if (update_backref_cache(trans, &rc->backref_cache)) { - btrfs_end_transaction(trans, rc->extent_root); - continue; - } + if (rc->backref_cache.last_trans != trans->transid) + btrfs_backref_release_cache(&rc->backref_cache); + rc->backref_cache.last_trans = trans->transid; - ret = find_next_extent(trans, rc, path, &key); + ret = find_next_extent(rc, path, &key); if (ret < 0) err = ret; if (ret != 0) @@ -3917,42 +3538,21 @@ restart: ei = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_item); - item_size = btrfs_item_size_nr(path->nodes[0], path->slots[0]); - if (item_size >= sizeof(*ei)) { - flags = btrfs_extent_flags(path->nodes[0], ei); - ret = check_extent_flags(flags); - BUG_ON(ret); - - } else { -#ifdef BTRFS_COMPAT_EXTENT_TREE_V0 - u64 ref_owner; - int path_change = 0; - - BUG_ON(item_size != - sizeof(struct btrfs_extent_item_v0)); - ret = get_ref_objectid_v0(rc, path, &key, &ref_owner, - &path_change); - if (ref_owner < BTRFS_FIRST_FREE_OBJECTID) - flags = BTRFS_EXTENT_FLAG_TREE_BLOCK; - else - flags = BTRFS_EXTENT_FLAG_DATA; + flags = btrfs_extent_flags(path->nodes[0], ei); - if (path_change) { - btrfs_release_path(path); + /* + * If we are relocating a simple quota owned extent item, we + * need to note the owner on the reloc data root so that when + * we allocate the replacement item, we can attribute it to the + * correct eventual owner (rather than the reloc data root). + */ + if (btrfs_qgroup_mode(fs_info) == BTRFS_QGROUP_MODE_SIMPLE) { + struct btrfs_root *root = BTRFS_I(rc->data_inode)->root; + u64 owning_root_id = btrfs_get_extent_owner_root(fs_info, + path->nodes[0], + path->slots[0]); - path->search_commit_root = 1; - path->skip_locking = 1; - ret = btrfs_search_slot(NULL, rc->extent_root, - &key, path, 0, 0); - if (ret < 0) { - err = ret; - break; - } - BUG_ON(ret > 0); - } -#else - BUG(); -#endif + root->relocation_src_root = owning_root_id; } if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { @@ -3981,41 +3581,27 @@ restart: } } - ret = btrfs_block_rsv_check(rc->extent_root, rc->block_rsv, 5); - if (ret < 0) { - if (ret != -ENOSPC) { - err = ret; - WARN_ON(1); - break; - } - rc->commit_transaction = 1; - } - - if (rc->commit_transaction) { - rc->commit_transaction = 0; - ret = btrfs_commit_transaction(trans, rc->extent_root); - BUG_ON(ret); - } else { - btrfs_end_transaction_throttle(trans, rc->extent_root); - btrfs_btree_balance_dirty(rc->extent_root); - } + btrfs_end_transaction_throttle(trans); + btrfs_btree_balance_dirty(fs_info); trans = NULL; if (rc->stage == MOVE_DATA_EXTENTS && (flags & BTRFS_EXTENT_FLAG_DATA)) { - rc->found_file_extent = 1; - ret = relocate_data_extent(rc->data_inode, - &key, &rc->cluster); + rc->found_file_extent = true; + ret = relocate_data_extent(rc, &key); if (ret < 0) { err = ret; break; } } + if (btrfs_should_cancel_balance(fs_info)) { + err = -ECANCELED; + break; + } } if (trans && progress && err == -ENOSPC) { - ret = btrfs_force_chunk_alloc(trans, rc->extent_root, - rc->block_group->flags); - if (ret == 0) { + ret = btrfs_force_chunk_alloc(trans, rc->block_group->flags); + if (ret == 1) { err = 0; progress = 0; goto restart; @@ -4023,51 +3609,62 @@ restart: } btrfs_release_path(path); - clear_extent_bits(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY, - GFP_NOFS); + btrfs_clear_extent_bit(&rc->processed_blocks, 0, (u64)-1, EXTENT_DIRTY, NULL); if (trans) { - btrfs_end_transaction_throttle(trans, rc->extent_root); - btrfs_btree_balance_dirty(rc->extent_root); + btrfs_end_transaction_throttle(trans); + btrfs_btree_balance_dirty(fs_info); } if (!err) { - ret = relocate_file_extent_cluster(rc->data_inode, - &rc->cluster); + ret = relocate_file_extent_cluster(rc); if (ret < 0) err = ret; } - rc->create_reloc_tree = 0; + rc->create_reloc_tree = false; set_reloc_control(rc); - backref_cache_cleanup(&rc->backref_cache); - btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1); + btrfs_backref_release_cache(&rc->backref_cache); + btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1, NULL); + /* + * Even in the case when the relocation is cancelled, we should all go + * through prepare_to_merge() and merge_reloc_roots(). + * + * For error (including cancelled balance), prepare_to_merge() will + * mark all reloc trees orphan, then queue them for cleanup in + * merge_reloc_roots() + */ err = prepare_to_merge(rc, err); merge_reloc_roots(rc); - rc->merge_reloc_tree = 0; + rc->merge_reloc_tree = false; unset_reloc_control(rc); - btrfs_block_rsv_release(rc->extent_root, rc->block_rsv, (u64)-1); + btrfs_block_rsv_release(fs_info, rc->block_rsv, (u64)-1, NULL); /* get rid of pinned extents */ trans = btrfs_join_transaction(rc->extent_root); - if (IS_ERR(trans)) + if (IS_ERR(trans)) { err = PTR_ERR(trans); - else - btrfs_commit_transaction(trans, rc->extent_root); + goto out_free; + } + ret = btrfs_commit_transaction(trans); + if (ret && !err) + err = ret; out_free: - btrfs_free_block_rsv(rc->extent_root, rc->block_rsv); - btrfs_free_path(path); + ret = clean_dirty_subvols(rc); + if (ret < 0 && !err) + err = ret; + btrfs_free_block_rsv(fs_info, rc->block_rsv); return err; } static int __insert_orphan_inode(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid) { - struct btrfs_path *path; + BTRFS_PATH_AUTO_FREE(path); struct btrfs_inode_item *item; struct extent_buffer *leaf; int ret; @@ -4078,70 +3675,138 @@ static int __insert_orphan_inode(struct btrfs_trans_handle *trans, ret = btrfs_insert_empty_inode(trans, root, path, objectid); if (ret) - goto out; + return ret; leaf = path->nodes[0]; item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_inode_item); - memset_extent_buffer(leaf, 0, (unsigned long)item, sizeof(*item)); + memzero_extent_buffer(leaf, (unsigned long)item, sizeof(*item)); btrfs_set_inode_generation(leaf, item, 1); btrfs_set_inode_size(leaf, item, 0); btrfs_set_inode_mode(leaf, item, S_IFREG | 0600); btrfs_set_inode_flags(leaf, item, BTRFS_INODE_NOCOMPRESS | BTRFS_INODE_PREALLOC); - btrfs_mark_buffer_dirty(leaf); - btrfs_release_path(path); + return 0; +} + +static void delete_orphan_inode(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 objectid) +{ + BTRFS_PATH_AUTO_FREE(path); + struct btrfs_key key; + int ret = 0; + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + key.objectid = objectid; + key.type = BTRFS_INODE_ITEM_KEY; + key.offset = 0; + ret = btrfs_search_slot(trans, root, &key, path, -1, 1); + if (ret) { + if (ret > 0) + ret = -ENOENT; + goto out; + } + ret = btrfs_del_item(trans, root, path); out: - btrfs_free_path(path); - return ret; + if (ret) + btrfs_abort_transaction(trans, ret); } /* * helper to create inode for data relocation. * the inode is in data relocation tree and its link count is 0 */ -static noinline_for_stack -struct inode *create_reloc_inode(struct btrfs_fs_info *fs_info, - struct btrfs_block_group_cache *group) +static noinline_for_stack struct inode *create_reloc_inode( + const struct btrfs_block_group *group) { - struct inode *inode = NULL; + struct btrfs_fs_info *fs_info = group->fs_info; + struct btrfs_inode *inode = NULL; struct btrfs_trans_handle *trans; struct btrfs_root *root; - struct btrfs_key key; - u64 objectid = BTRFS_FIRST_FREE_OBJECTID; - int err = 0; - - root = read_fs_root(fs_info, BTRFS_DATA_RELOC_TREE_OBJECTID); - if (IS_ERR(root)) - return ERR_CAST(root); + u64 objectid; + int ret = 0; + root = btrfs_grab_root(fs_info->data_reloc_root); trans = btrfs_start_transaction(root, 6); - if (IS_ERR(trans)) + if (IS_ERR(trans)) { + btrfs_put_root(root); return ERR_CAST(trans); + } - err = btrfs_find_free_objectid(root, &objectid); - if (err) + ret = btrfs_get_free_objectid(root, &objectid); + if (ret) goto out; - err = __insert_orphan_inode(trans, root, objectid); - BUG_ON(err); + ret = __insert_orphan_inode(trans, root, objectid); + if (ret) + goto out; - key.objectid = objectid; - key.type = BTRFS_INODE_ITEM_KEY; - key.offset = 0; - inode = btrfs_iget(root->fs_info->sb, &key, root, NULL); - BUG_ON(IS_ERR(inode) || is_bad_inode(inode)); - BTRFS_I(inode)->index_cnt = group->key.objectid; + inode = btrfs_iget(objectid, root); + if (IS_ERR(inode)) { + delete_orphan_inode(trans, root, objectid); + ret = PTR_ERR(inode); + inode = NULL; + goto out; + } + inode->reloc_block_group_start = group->start; - err = btrfs_orphan_add(trans, inode); + ret = btrfs_orphan_add(trans, inode); out: - btrfs_end_transaction(trans, root); - btrfs_btree_balance_dirty(root); - if (err) { + btrfs_put_root(root); + btrfs_end_transaction(trans); + btrfs_btree_balance_dirty(fs_info); + if (ret) { if (inode) - iput(inode); - inode = ERR_PTR(err); + iput(&inode->vfs_inode); + return ERR_PTR(ret); + } + return &inode->vfs_inode; +} + +/* + * Mark start of chunk relocation that is cancellable. Check if the cancellation + * has been requested meanwhile and don't start in that case. + * NOTE: if this returns an error, reloc_chunk_end() must not be called. + * + * Return: + * 0 success + * -EINPROGRESS operation is already in progress, that's probably a bug + * -ECANCELED cancellation request was set before the operation started + */ +static int reloc_chunk_start(struct btrfs_fs_info *fs_info) +{ + if (test_and_set_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags)) { + /* This should not happen */ + btrfs_err(fs_info, "reloc already running, cannot start"); + return -EINPROGRESS; + } + + if (atomic_read(&fs_info->reloc_cancel_req) > 0) { + btrfs_info(fs_info, "chunk relocation canceled on start"); + /* On cancel, clear all requests. */ + clear_and_wake_up_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags); + atomic_set(&fs_info->reloc_cancel_req, 0); + return -ECANCELED; } - return inode; + return 0; +} + +/* + * Mark end of chunk relocation that is cancellable and wake any waiters. + * NOTE: call only if a previous call to reloc_chunk_start() succeeded. + */ +static void reloc_chunk_end(struct btrfs_fs_info *fs_info) +{ + ASSERT(test_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags)); + /* Requested after start, clear bit first so any waiters can continue */ + if (atomic_read(&fs_info->reloc_cancel_req) > 0) + btrfs_info(fs_info, "chunk relocation canceled during operation"); + clear_and_wake_up_bit(BTRFS_FS_RELOC_RUNNING, &fs_info->flags); + atomic_set(&fs_info->reloc_cancel_req, 0); } static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info) @@ -4153,139 +3818,220 @@ static struct reloc_control *alloc_reloc_control(struct btrfs_fs_info *fs_info) return NULL; INIT_LIST_HEAD(&rc->reloc_roots); - backref_cache_init(&rc->backref_cache); - mapping_tree_init(&rc->reloc_root_tree); - extent_io_tree_init(&rc->processed_blocks, - fs_info->btree_inode->i_mapping); + INIT_LIST_HEAD(&rc->dirty_subvol_roots); + btrfs_backref_init_cache(fs_info, &rc->backref_cache, true); + rc->reloc_root_tree.rb_root = RB_ROOT; + spin_lock_init(&rc->reloc_root_tree.lock); + btrfs_extent_io_tree_init(fs_info, &rc->processed_blocks, IO_TREE_RELOC_BLOCKS); return rc; } +static void free_reloc_control(struct reloc_control *rc) +{ + struct mapping_node *node, *tmp; + + free_reloc_roots(&rc->reloc_roots); + rbtree_postorder_for_each_entry_safe(node, tmp, + &rc->reloc_root_tree.rb_root, rb_node) + kfree(node); + + kfree(rc); +} + +/* + * Print the block group being relocated + */ +static void describe_relocation(struct btrfs_block_group *block_group) +{ + char buf[128] = "NONE"; + + btrfs_describe_block_groups(block_group->flags, buf, sizeof(buf)); + + btrfs_info(block_group->fs_info, "relocating block group %llu flags %s", + block_group->start, buf); +} + +static const char *stage_to_string(enum reloc_stage stage) +{ + if (stage == MOVE_DATA_EXTENTS) + return "move data extents"; + if (stage == UPDATE_DATA_PTRS) + return "update data pointers"; + return "unknown"; +} + /* * function to relocate all extents in a block group. */ -int btrfs_relocate_block_group(struct btrfs_root *extent_root, u64 group_start) +int btrfs_relocate_block_group(struct btrfs_fs_info *fs_info, u64 group_start, + bool verbose) { - struct btrfs_fs_info *fs_info = extent_root->fs_info; + struct btrfs_block_group *bg; + struct btrfs_root *extent_root = btrfs_extent_root(fs_info, group_start); struct reloc_control *rc; struct inode *inode; struct btrfs_path *path; int ret; - int rw = 0; - int err = 0; + bool bg_is_ro = false; + + /* + * This only gets set if we had a half-deleted snapshot on mount. We + * cannot allow relocation to start while we're still trying to clean up + * these pending deletions. + */ + ret = wait_on_bit(&fs_info->flags, BTRFS_FS_UNFINISHED_DROPS, TASK_INTERRUPTIBLE); + if (ret) + return ret; + + /* We may have been woken up by close_ctree, so bail if we're closing. */ + if (btrfs_fs_closing(fs_info)) + return -EINTR; + + bg = btrfs_lookup_block_group(fs_info, group_start); + if (!bg) + return -ENOENT; + + /* + * Relocation of a data block group creates ordered extents. Without + * sb_start_write(), we can freeze the filesystem while unfinished + * ordered extents are left. Such ordered extents can cause a deadlock + * e.g. when syncfs() is waiting for their completion but they can't + * finish because they block when joining a transaction, due to the + * fact that the freeze locks are being held in write mode. + */ + if (bg->flags & BTRFS_BLOCK_GROUP_DATA) + ASSERT(sb_write_started(fs_info->sb)); + + if (btrfs_pinned_by_swapfile(fs_info, bg)) { + btrfs_put_block_group(bg); + return -ETXTBSY; + } rc = alloc_reloc_control(fs_info); - if (!rc) + if (!rc) { + btrfs_put_block_group(bg); return -ENOMEM; + } - rc->extent_root = extent_root; + ret = reloc_chunk_start(fs_info); + if (ret < 0) + goto out_put_bg; - rc->block_group = btrfs_lookup_block_group(fs_info, group_start); - BUG_ON(!rc->block_group); + rc->extent_root = extent_root; + rc->block_group = bg; - if (!rc->block_group->ro) { - ret = btrfs_set_block_group_ro(extent_root, rc->block_group); - if (ret) { - err = ret; - goto out; - } - rw = 1; - } + ret = btrfs_inc_block_group_ro(rc->block_group, true); + if (ret) + goto out; + bg_is_ro = true; path = btrfs_alloc_path(); if (!path) { - err = -ENOMEM; + ret = -ENOMEM; goto out; } - inode = lookup_free_space_inode(fs_info->tree_root, rc->block_group, - path); + inode = lookup_free_space_inode(rc->block_group, path); btrfs_free_path(path); if (!IS_ERR(inode)) - ret = delete_block_group_cache(fs_info, inode, 0); + ret = delete_block_group_cache(rc->block_group, inode, 0); else ret = PTR_ERR(inode); - if (ret && ret != -ENOENT) { - err = ret; + if (ret && ret != -ENOENT) goto out; - } - rc->data_inode = create_reloc_inode(fs_info, rc->block_group); + rc->data_inode = create_reloc_inode(rc->block_group); if (IS_ERR(rc->data_inode)) { - err = PTR_ERR(rc->data_inode); + ret = PTR_ERR(rc->data_inode); rc->data_inode = NULL; goto out; } - printk(KERN_INFO "btrfs: relocating block group %llu flags %llu\n", - (unsigned long long)rc->block_group->key.objectid, - (unsigned long long)rc->block_group->flags); + if (verbose) + describe_relocation(rc->block_group); - ret = btrfs_start_all_delalloc_inodes(fs_info, 0); - if (ret < 0) { - err = ret; - goto out; - } - btrfs_wait_all_ordered_extents(fs_info, 0); + btrfs_wait_block_group_reservations(rc->block_group); + btrfs_wait_nocow_writers(rc->block_group); + btrfs_wait_ordered_roots(fs_info, U64_MAX, rc->block_group); + + ret = btrfs_zone_finish(rc->block_group); + WARN_ON(ret && ret != -EAGAIN); while (1) { + enum reloc_stage finishes_stage; + mutex_lock(&fs_info->cleaner_mutex); ret = relocate_block_group(rc); mutex_unlock(&fs_info->cleaner_mutex); - if (ret < 0) { - err = ret; - goto out; - } - - if (rc->extents_found == 0) - break; - - printk(KERN_INFO "btrfs: found %llu extents\n", - (unsigned long long)rc->extents_found); + finishes_stage = rc->stage; + /* + * We may have gotten ENOSPC after we already dirtied some + * extents. If writeout happens while we're relocating a + * different block group we could end up hitting the + * BUG_ON(rc->stage == UPDATE_DATA_PTRS) in + * btrfs_reloc_cow_block. Make sure we write everything out + * properly so we don't trip over this problem, and then break + * out of the loop if we hit an error. + */ if (rc->stage == MOVE_DATA_EXTENTS && rc->found_file_extent) { - btrfs_wait_ordered_range(rc->data_inode, 0, (u64)-1); + int wb_ret; + + wb_ret = btrfs_wait_ordered_range(BTRFS_I(rc->data_inode), 0, + (u64)-1); + if (wb_ret && ret == 0) + ret = wb_ret; invalidate_mapping_pages(rc->data_inode->i_mapping, 0, -1); rc->stage = UPDATE_DATA_PTRS; } - } - filemap_write_and_wait_range(fs_info->btree_inode->i_mapping, - rc->block_group->key.objectid, - rc->block_group->key.objectid + - rc->block_group->key.offset - 1); + if (ret < 0) + goto out; + + if (rc->extents_found == 0) + break; + + if (verbose) + btrfs_info(fs_info, "found %llu extents, stage: %s", + rc->extents_found, + stage_to_string(finishes_stage)); + } WARN_ON(rc->block_group->pinned > 0); WARN_ON(rc->block_group->reserved > 0); - WARN_ON(btrfs_block_group_used(&rc->block_group->item) > 0); + WARN_ON(rc->block_group->used > 0); out: - if (err && rw) - btrfs_set_block_group_rw(extent_root, rc->block_group); + if (ret && bg_is_ro) + btrfs_dec_block_group_ro(rc->block_group); iput(rc->data_inode); - btrfs_put_block_group(rc->block_group); - kfree(rc); - return err; + reloc_chunk_end(fs_info); +out_put_bg: + btrfs_put_block_group(bg); + free_reloc_control(rc); + return ret; } static noinline_for_stack int mark_garbage_root(struct btrfs_root *root) { + struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_trans_handle *trans; int ret, err; - trans = btrfs_start_transaction(root->fs_info->tree_root, 0); + trans = btrfs_start_transaction(fs_info->tree_root, 0); if (IS_ERR(trans)) return PTR_ERR(trans); memset(&root->root_item.drop_progress, 0, sizeof(root->root_item.drop_progress)); - root->root_item.drop_level = 0; + btrfs_set_root_drop_level(&root->root_item, 0); btrfs_set_root_refs(&root->root_item, 0); - ret = btrfs_update_root(trans, root->fs_info->tree_root, + ret = btrfs_update_root(trans, fs_info->tree_root, &root->root_key, &root->root_item); - err = btrfs_end_transaction(trans, root->fs_info->tree_root); + err = btrfs_end_transaction(trans); if (err) return err; return ret; @@ -4297,7 +4043,7 @@ static noinline_for_stack int mark_garbage_root(struct btrfs_root *root) * this function resumes merging reloc trees with corresponding fs trees. * this is important for keeping the sharing of tree blocks */ -int btrfs_recover_relocation(struct btrfs_root *root) +int btrfs_recover_relocation(struct btrfs_fs_info *fs_info) { LIST_HEAD(reloc_roots); struct btrfs_key key; @@ -4307,30 +4053,29 @@ int btrfs_recover_relocation(struct btrfs_root *root) struct extent_buffer *leaf; struct reloc_control *rc = NULL; struct btrfs_trans_handle *trans; - int ret; - int err = 0; + int ret2; + int ret = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; - path->reada = -1; + path->reada = READA_BACK; key.objectid = BTRFS_TREE_RELOC_OBJECTID; key.type = BTRFS_ROOT_ITEM_KEY; key.offset = (u64)-1; while (1) { - ret = btrfs_search_slot(NULL, root->fs_info->tree_root, &key, + ret = btrfs_search_slot(NULL, fs_info->tree_root, &key, path, 0, 0); - if (ret < 0) { - err = ret; + if (ret < 0) goto out; - } if (ret > 0) { if (path->slots[0] == 0) break; path->slots[0]--; } + ret = 0; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); btrfs_release_path(path); @@ -4339,28 +4084,28 @@ int btrfs_recover_relocation(struct btrfs_root *root) key.type != BTRFS_ROOT_ITEM_KEY) break; - reloc_root = btrfs_read_fs_root(root, &key); + reloc_root = btrfs_read_tree_root(fs_info->tree_root, &key); if (IS_ERR(reloc_root)) { - err = PTR_ERR(reloc_root); + ret = PTR_ERR(reloc_root); goto out; } + set_bit(BTRFS_ROOT_SHAREABLE, &reloc_root->state); list_add(&reloc_root->root_list, &reloc_roots); if (btrfs_root_refs(&reloc_root->root_item) > 0) { - fs_root = read_fs_root(root->fs_info, - reloc_root->root_key.offset); + fs_root = btrfs_get_fs_root(fs_info, + reloc_root->root_key.offset, false); if (IS_ERR(fs_root)) { ret = PTR_ERR(fs_root); - if (ret != -ENOENT) { - err = ret; + if (ret != -ENOENT) goto out; - } ret = mark_garbage_root(reloc_root); - if (ret < 0) { - err = ret; + if (ret < 0) goto out; - } + ret = 0; + } else { + btrfs_put_root(fs_root); } } @@ -4374,28 +4119,30 @@ int btrfs_recover_relocation(struct btrfs_root *root) if (list_empty(&reloc_roots)) goto out; - rc = alloc_reloc_control(root->fs_info); + rc = alloc_reloc_control(fs_info); if (!rc) { - err = -ENOMEM; + ret = -ENOMEM; goto out; } - rc->extent_root = root->fs_info->extent_root; + ret = reloc_chunk_start(fs_info); + if (ret < 0) + goto out_end; + + rc->extent_root = btrfs_extent_root(fs_info, 0); set_reloc_control(rc); trans = btrfs_join_transaction(rc->extent_root); if (IS_ERR(trans)) { - unset_reloc_control(rc); - err = PTR_ERR(trans); - goto out_free; + ret = PTR_ERR(trans); + goto out_unset; } - rc->merge_reloc_tree = 1; + rc->merge_reloc_tree = true; while (!list_empty(&reloc_roots)) { - reloc_root = list_entry(reloc_roots.next, - struct btrfs_root, root_list); + reloc_root = list_first_entry(&reloc_roots, struct btrfs_root, root_list); list_del(&reloc_root->root_list); if (btrfs_root_refs(&reloc_root->root_item) == 0) { @@ -4404,49 +4151,63 @@ int btrfs_recover_relocation(struct btrfs_root *root) continue; } - fs_root = read_fs_root(root->fs_info, - reloc_root->root_key.offset); + fs_root = btrfs_get_fs_root(fs_info, reloc_root->root_key.offset, + false); if (IS_ERR(fs_root)) { - err = PTR_ERR(fs_root); - goto out_free; + ret = PTR_ERR(fs_root); + list_add_tail(&reloc_root->root_list, &reloc_roots); + btrfs_end_transaction(trans); + goto out_unset; } - err = __add_reloc_root(reloc_root); - BUG_ON(err < 0); /* -ENOMEM or logic error */ - fs_root->reloc_root = reloc_root; + ret = __add_reloc_root(reloc_root); + ASSERT(ret != -EEXIST); + if (ret) { + list_add_tail(&reloc_root->root_list, &reloc_roots); + btrfs_put_root(fs_root); + btrfs_end_transaction(trans); + goto out_unset; + } + fs_root->reloc_root = btrfs_grab_root(reloc_root); + btrfs_put_root(fs_root); } - err = btrfs_commit_transaction(trans, rc->extent_root); - if (err) - goto out_free; + ret = btrfs_commit_transaction(trans); + if (ret) + goto out_unset; merge_reloc_roots(rc); unset_reloc_control(rc); trans = btrfs_join_transaction(rc->extent_root); - if (IS_ERR(trans)) - err = PTR_ERR(trans); - else - err = btrfs_commit_transaction(trans, rc->extent_root); -out_free: - kfree(rc); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out_clean; + } + ret = btrfs_commit_transaction(trans); +out_clean: + ret2 = clean_dirty_subvols(rc); + if (ret2 < 0 && !ret) + ret = ret2; +out_unset: + unset_reloc_control(rc); + reloc_chunk_end(fs_info); +out_end: + free_reloc_control(rc); out: - if (!list_empty(&reloc_roots)) - free_reloc_roots(&reloc_roots); + free_reloc_roots(&reloc_roots); btrfs_free_path(path); - if (err == 0) { + if (ret == 0) { /* cleanup orphan inode in data relocation tree */ - fs_root = read_fs_root(root->fs_info, - BTRFS_DATA_RELOC_TREE_OBJECTID); - if (IS_ERR(fs_root)) - err = PTR_ERR(fs_root); - else - err = btrfs_orphan_cleanup(fs_root); + fs_root = btrfs_grab_root(fs_info->data_reloc_root); + ASSERT(fs_root); + ret = btrfs_orphan_cleanup(fs_root); + btrfs_put_root(fs_root); } - return err; + return ret; } /* @@ -4455,71 +4216,90 @@ out: * cloning checksum properly handles the nodatasum extents. * it also saves CPU time to re-calculate the checksum. */ -int btrfs_reloc_clone_csums(struct inode *inode, u64 file_pos, u64 len) +int btrfs_reloc_clone_csums(struct btrfs_ordered_extent *ordered) { - struct btrfs_ordered_sum *sums; - struct btrfs_ordered_extent *ordered; - struct btrfs_root *root = BTRFS_I(inode)->root; - int ret; - u64 disk_bytenr; + struct btrfs_inode *inode = ordered->inode; + struct btrfs_fs_info *fs_info = inode->root->fs_info; + u64 disk_bytenr = ordered->file_offset + inode->reloc_block_group_start; + struct btrfs_root *csum_root = btrfs_csum_root(fs_info, disk_bytenr); LIST_HEAD(list); + int ret; - ordered = btrfs_lookup_ordered_extent(inode, file_pos); - BUG_ON(ordered->file_offset != file_pos || ordered->len != len); - - disk_bytenr = file_pos + BTRFS_I(inode)->index_cnt; - ret = btrfs_lookup_csums_range(root->fs_info->csum_root, disk_bytenr, - disk_bytenr + len - 1, &list, 0); - if (ret) - goto out; + ret = btrfs_lookup_csums_list(csum_root, disk_bytenr, + disk_bytenr + ordered->num_bytes - 1, + &list, false); + if (ret < 0) { + btrfs_mark_ordered_extent_error(ordered); + return ret; + } - disk_bytenr = ordered->start; while (!list_empty(&list)) { - sums = list_entry(list.next, struct btrfs_ordered_sum, list); - list_del_init(&sums->list); + struct btrfs_ordered_sum *sums = + list_first_entry(&list, struct btrfs_ordered_sum, list); - sums->bytenr = disk_bytenr; - disk_bytenr += sums->len; + list_del_init(&sums->list); - btrfs_add_ordered_sum(inode, ordered, sums); + /* + * We need to offset the new_bytenr based on where the csum is. + * We need to do this because we will read in entire prealloc + * extents but we may have written to say the middle of the + * prealloc extent, so we need to make sure the csum goes with + * the right disk offset. + * + * We can do this because the data reloc inode refers strictly + * to the on disk bytes, so we don't have to worry about + * disk_len vs real len like with real inodes since it's all + * disk length. + */ + sums->logical = ordered->disk_bytenr + sums->logical - disk_bytenr; + btrfs_add_ordered_sum(ordered, sums); } -out: - btrfs_put_ordered_extent(ordered); - return ret; + + return 0; } -void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans, - struct btrfs_root *root, struct extent_buffer *buf, - struct extent_buffer *cow) +int btrfs_reloc_cow_block(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + const struct extent_buffer *buf, + struct extent_buffer *cow) { + struct btrfs_fs_info *fs_info = root->fs_info; struct reloc_control *rc; - struct backref_node *node; + struct btrfs_backref_node *node; int first_cow = 0; int level; - int ret; + int ret = 0; - rc = root->fs_info->reloc_ctl; + rc = fs_info->reloc_ctl; if (!rc) - return; + return 0; - BUG_ON(rc->stage == UPDATE_DATA_PTRS && - root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID); + BUG_ON(rc->stage == UPDATE_DATA_PTRS && btrfs_is_data_reloc_root(root)); level = btrfs_header_level(buf); if (btrfs_header_generation(buf) <= btrfs_root_last_snapshot(&root->root_item)) first_cow = 1; - if (root->root_key.objectid == BTRFS_TREE_RELOC_OBJECTID && - rc->create_reloc_tree) { + if (btrfs_root_id(root) == BTRFS_TREE_RELOC_OBJECTID && rc->create_reloc_tree) { WARN_ON(!first_cow && level == 0); node = rc->backref_cache.path[level]; - BUG_ON(node->bytenr != buf->start && - node->new_bytenr != buf->start); - drop_node_buffer(node); - extent_buffer_get(cow); + /* + * If node->bytenr != buf->start and node->new_bytenr != + * buf->start then we've got the wrong backref node for what we + * expected to see here and the cache is incorrect. + */ + if (unlikely(node->bytenr != buf->start && node->new_bytenr != buf->start)) { + btrfs_err(fs_info, +"bytenr %llu was found but our backref cache was expecting %llu or %llu", + buf->start, node->bytenr, node->new_bytenr); + return -EUCLEAN; + } + + btrfs_backref_drop_node_buffer(node); + refcount_inc(&cow->refs); node->eb = cow; node->new_bytenr = cow->start; @@ -4530,34 +4310,30 @@ void btrfs_reloc_cow_block(struct btrfs_trans_handle *trans, } if (first_cow) - __mark_block_processed(rc, node); + mark_block_processed(rc, node); if (first_cow && level > 0) rc->nodes_relocated += buf->len; } - if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) { + if (level == 0 && first_cow && rc->stage == UPDATE_DATA_PTRS) ret = replace_file_extents(trans, rc, root, cow); - BUG_ON(ret); - } + return ret; } /* * called before creating snapshot. it calculates metadata reservation - * requried for relocating tree blocks in the snapshot + * required for relocating tree blocks in the snapshot */ -void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans, - struct btrfs_pending_snapshot *pending, +void btrfs_reloc_pre_snapshot(struct btrfs_pending_snapshot *pending, u64 *bytes_to_reserve) { - struct btrfs_root *root; - struct reloc_control *rc; + struct btrfs_root *root = pending->root; + struct reloc_control *rc = root->fs_info->reloc_ctl; - root = pending->root; - if (!root->reloc_root) + if (!rc || !have_reloc_root(root)) return; - rc = root->fs_info->reloc_ctl; if (!rc->merge_reloc_tree) return; @@ -4579,6 +4355,10 @@ void btrfs_reloc_pre_snapshot(struct btrfs_trans_handle *trans, /* * called after snapshot is created. migrate block reservation * and create reloc root for the newly created snapshot + * + * This is similar to btrfs_init_reloc_root(), we come out of here with two + * references held on the reloc_root, one for root->reloc_root and one for + * rc->reloc_roots. */ int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans, struct btrfs_pending_snapshot *pending) @@ -4586,10 +4366,10 @@ int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root *root = pending->root; struct btrfs_root *reloc_root; struct btrfs_root *new_root; - struct reloc_control *rc; + struct reloc_control *rc = root->fs_info->reloc_ctl; int ret; - if (!root->reloc_root) + if (!rc || !have_reloc_root(root)) return 0; rc = root->fs_info->reloc_ctl; @@ -4598,22 +4378,39 @@ int btrfs_reloc_post_snapshot(struct btrfs_trans_handle *trans, if (rc->merge_reloc_tree) { ret = btrfs_block_rsv_migrate(&pending->block_rsv, rc->block_rsv, - rc->nodes_relocated); + rc->nodes_relocated, true); if (ret) return ret; } new_root = pending->snap; - reloc_root = create_reloc_root(trans, root->reloc_root, - new_root->root_key.objectid); + reloc_root = create_reloc_root(trans, root->reloc_root, btrfs_root_id(new_root)); if (IS_ERR(reloc_root)) return PTR_ERR(reloc_root); ret = __add_reloc_root(reloc_root); - BUG_ON(ret < 0); - new_root->reloc_root = reloc_root; + ASSERT(ret != -EEXIST); + if (ret) { + /* Pairs with create_reloc_root */ + btrfs_put_root(reloc_root); + return ret; + } + new_root->reloc_root = btrfs_grab_root(reloc_root); + return 0; +} - if (rc->create_reloc_tree) - ret = clone_backref_node(trans, rc, root, reloc_root); - return ret; +/* + * Get the current bytenr for the block group which is being relocated. + * + * Return U64_MAX if no running relocation. + */ +u64 btrfs_get_reloc_bg_bytenr(const struct btrfs_fs_info *fs_info) +{ + u64 logical = U64_MAX; + + lockdep_assert_held(&fs_info->reloc_mutex); + + if (fs_info->reloc_ctl && fs_info->reloc_ctl->block_group) + logical = fs_info->reloc_ctl->block_group->start; + return logical; } |