diff options
author | Qu Wenruo <wqu@suse.com> | 2020-03-05 09:22:43 +0300 |
---|---|---|
committer | David Sterba <dsterba@suse.com> | 2020-05-25 12:25:17 +0300 |
commit | 4d81ea8bb4fc40903f4950b082955c709d785467 (patch) | |
tree | 5daf5da5bb1dce144b22c422cffa2f0bbbe2b381 /fs/btrfs/relocation.c | |
parent | 4007ea87d900e20a7986cdcdcfdc866e8f8bd473 (diff) | |
download | linux-4d81ea8bb4fc40903f4950b082955c709d785467.tar.xz |
btrfs: reloc: refactor indirect tree backref processing into its own function
The processing of indirect tree backref (TREE_BLOCK_REF) is the most
complex work.
We need to grab the fs root, do a tree search to locate all its parent
nodes, link all needed edges, and put all uncached edges to pending edge
list.
This is definitely worth a helper function.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/relocation.c')
-rw-r--r-- | fs/btrfs/relocation.c | 294 |
1 files changed, 159 insertions, 135 deletions
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index ff0b2f9b68eb..18a4b3f57b14 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -774,6 +774,163 @@ static int handle_direct_tree_backref(struct backref_cache *cache, } /* + * Handle indirect tree backref + * + * Indirect tree backref means, we only know which tree the node belongs to. + * We still need to do a tree search to find out the parents. This is for + * TREE_BLOCK_REF backref (keyed or inlined). + * + * @ref_key: The same as @ref_key in handle_direct_tree_backref() + * @tree_key: The first key of this tree block. + * @path: A clean (released) path, to avoid allocating path everytime + * the function get called. + */ +static int handle_indirect_tree_backref(struct backref_cache *cache, + struct btrfs_path *path, + struct btrfs_key *ref_key, + struct btrfs_key *tree_key, + struct backref_node *cur) +{ + struct btrfs_fs_info *fs_info = cache->fs_info; + struct backref_node *upper; + struct backref_node *lower; + struct backref_edge *edge; + struct extent_buffer *eb; + struct btrfs_root *root; + struct rb_node *rb_node; + int level; + bool need_check = true; + int ret; + + root = read_fs_root(fs_info, ref_key->offset); + if (IS_ERR(root)) + return PTR_ERR(root); + if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) + cur->cowonly = 1; + + if (btrfs_root_level(&root->root_item) == cur->level) { + /* Tree root */ + ASSERT(btrfs_root_bytenr(&root->root_item) == cur->bytenr); + if (should_ignore_root(root)) { + btrfs_put_root(root); + list_add(&cur->list, &cache->useless_node); + } else { + cur->root = root; + } + return 0; + } + + level = cur->level + 1; + + /* Search the tree to find parent blocks referring to the block */ + path->search_commit_root = 1; + path->skip_locking = 1; + path->lowest_level = level; + ret = btrfs_search_slot(NULL, root, tree_key, path, 0, 0); + path->lowest_level = 0; + if (ret < 0) { + btrfs_put_root(root); + return ret; + } + if (ret > 0 && path->slots[level] > 0) + path->slots[level]--; + + eb = path->nodes[level]; + if (btrfs_node_blockptr(eb, path->slots[level]) != cur->bytenr) { + btrfs_err(fs_info, +"couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)", + cur->bytenr, level - 1, root->root_key.objectid, + tree_key->objectid, tree_key->type, tree_key->offset); + btrfs_put_root(root); + ret = -ENOENT; + goto out; + } + lower = cur; + + /* Add all nodes and edges in the path */ + for (; level < BTRFS_MAX_LEVEL; level++) { + if (!path->nodes[level]) { + ASSERT(btrfs_root_bytenr(&root->root_item) == + lower->bytenr); + if (should_ignore_root(root)) { + btrfs_put_root(root); + list_add(&lower->list, &cache->useless_node); + } else { + lower->root = root; + } + break; + } + + edge = alloc_backref_edge(cache); + if (!edge) { + btrfs_put_root(root); + ret = -ENOMEM; + goto out; + } + + eb = path->nodes[level]; + rb_node = tree_search(&cache->rb_root, eb->start); + if (!rb_node) { + upper = alloc_backref_node(cache); + if (!upper) { + btrfs_put_root(root); + free_backref_edge(cache, edge); + ret = -ENOMEM; + goto out; + } + upper->bytenr = eb->start; + upper->owner = btrfs_header_owner(eb); + upper->level = lower->level + 1; + if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) + upper->cowonly = 1; + + /* + * If we know the block isn't shared we can avoid + * 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 to check its + * backrefs, we only do this once while walking up a + * tree as we will catch anything else later on. + */ + if (!upper->checked && need_check) { + need_check = false; + list_add_tail(&edge->list[UPPER], + &cache->pending_edge); + } else { + if (upper->checked) + need_check = true; + INIT_LIST_HEAD(&edge->list[UPPER]); + } + } else { + upper = rb_entry(rb_node, struct backref_node, rb_node); + ASSERT(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) { + btrfs_put_root(root); + break; + } + lower = upper; + upper = NULL; + } +out: + btrfs_release_path(path); + 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. @@ -796,7 +953,6 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, struct backref_cache *cache = &rc->backref_cache; /* For searching parent of TREE_BLOCK_REF */ struct btrfs_path *path; - struct btrfs_root *root; struct backref_node *cur; struct backref_node *upper; struct backref_node *lower; @@ -807,7 +963,6 @@ struct backref_node *build_backref_tree(struct reloc_control *rc, int cowonly; int ret; int err = 0; - bool need_check = true; iter = btrfs_backref_iter_alloc(rc->extent_root->fs_info, GFP_NOFS); if (!iter) @@ -936,143 +1091,12 @@ again: * means the root objectid. We need to search the tree to get * its parent bytenr. */ - root = read_fs_root(rc->extent_root->fs_info, key.offset); - if (IS_ERR(root)) { - err = PTR_ERR(root); - goto out; - } - - if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state)) - cur->cowonly = 1; - - if (btrfs_root_level(&root->root_item) == cur->level) { - /* tree root */ - ASSERT(btrfs_root_bytenr(&root->root_item) == - cur->bytenr); - if (should_ignore_root(root)) { - btrfs_put_root(root); - list_add(&cur->list, &cache->useless_node); - } else { - cur->root = root; - } - break; - } - - level = cur->level + 1; - - /* Search the tree to find parent blocks referring the block. */ - path->search_commit_root = 1; - path->skip_locking = 1; - path->lowest_level = level; - ret = btrfs_search_slot(NULL, root, node_key, path, 0, 0); - path->lowest_level = 0; + ret = handle_indirect_tree_backref(cache, path, &key, node_key, + cur); if (ret < 0) { - btrfs_put_root(root); err = ret; goto out; } - if (ret > 0 && path->slots[level] > 0) - path->slots[level]--; - - eb = path->nodes[level]; - if (btrfs_node_blockptr(eb, path->slots[level]) != - cur->bytenr) { - btrfs_err(root->fs_info, - "couldn't find block (%llu) (level %d) in tree (%llu) with key (%llu %u %llu)", - cur->bytenr, level - 1, - root->root_key.objectid, - node_key->objectid, node_key->type, - node_key->offset); - btrfs_put_root(root); - err = -ENOENT; - goto out; - } - lower = cur; - need_check = true; - - /* Add all nodes and edges in the path */ - for (; level < BTRFS_MAX_LEVEL; level++) { - if (!path->nodes[level]) { - ASSERT(btrfs_root_bytenr(&root->root_item) == - lower->bytenr); - if (should_ignore_root(root)) { - btrfs_put_root(root); - list_add(&lower->list, - &cache->useless_node); - } else { - lower->root = root; - } - break; - } - - edge = alloc_backref_edge(cache); - if (!edge) { - btrfs_put_root(root); - err = -ENOMEM; - goto out; - } - - eb = path->nodes[level]; - rb_node = tree_search(&cache->rb_root, eb->start); - if (!rb_node) { - upper = alloc_backref_node(cache); - if (!upper) { - btrfs_put_root(root); - 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 (!test_bit(BTRFS_ROOT_REF_COWS, - &root->state)) - 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, we only do this once - * while walking up a tree as we will catch - * anything else later on. - */ - if (!upper->checked && need_check) { - need_check = false; - list_add_tail(&edge->list[UPPER], - &cache->pending_edge); - } else { - if (upper->checked) - need_check = true; - INIT_LIST_HEAD(&edge->list[UPPER]); - } - } else { - upper = rb_entry(rb_node, struct backref_node, - rb_node); - ASSERT(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) { - btrfs_put_root(root); - break; - } - lower = upper; - upper = NULL; - } - btrfs_release_path(path); } if (ret < 0) { err = ret; |