diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 832071bbb8c9061d3532c568b54d6de8a3f4ecd1..3b355be95171a10e26d076aa0184b670e8863196 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -2830,6 +2830,7 @@ static int handle_indirect_tree_backref(struct btrfs_backref_cache *cache, * * NOTE: Even if the function returned 0, @cur is not yet cached as its upper * links aren't yet bi-directional. Needs to finish such links. + * Use btrfs_backref_finish_upper_links() to finish such linkage. * * @path: Released path for indirect tree backref lookup * @iter: Released backref iter for extent tree search @@ -2957,3 +2958,108 @@ int btrfs_backref_add_tree_node(struct btrfs_backref_cache *cache, btrfs_backref_iter_release(iter); return ret; } + +/* + * Finish the upwards linkage created by btrfs_backref_add_tree_node() + */ +int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache, + struct btrfs_backref_node *start) +{ + struct list_head *useless_node = &cache->useless_node; + struct btrfs_backref_edge *edge; + struct rb_node *rb_node; + LIST_HEAD(pending_edge); + + ASSERT(start->checked); + + /* Insert this node to cache if it's not COW-only */ + if (!start->cowonly) { + rb_node = rb_simple_insert(&cache->rb_root, start->bytenr, + &start->rb_node); + if (rb_node) + btrfs_backref_panic(cache->fs_info, start->bytenr, + -EEXIST); + list_add_tail(&start->lower, &cache->leaves); + } + + /* + * Use breadth first search to iterate all related edges. + * + * The starting points are all the edges of this node + */ + list_for_each_entry(edge, &start->upper, list[LOWER]) + list_add_tail(&edge->list[UPPER], &pending_edge); + + while (!list_empty(&pending_edge)) { + struct btrfs_backref_node *upper; + struct btrfs_backref_node *lower; + struct rb_node *rb_node; + + edge = list_first_entry(&pending_edge, + struct btrfs_backref_edge, list[UPPER]); + list_del_init(&edge->list[UPPER]); + upper = edge->node[UPPER]; + lower = edge->node[LOWER]; + + /* Parent is detached, no need to keep any edges */ + if (upper->detached) { + list_del(&edge->list[LOWER]); + btrfs_backref_free_edge(cache, edge); + + /* Lower node is orphan, queue for cleanup */ + if (list_empty(&lower->upper)) + list_add(&lower->list, useless_node); + continue; + } + + /* + * All new nodes added in current build_backref_tree() haven't + * been linked to the cache rb tree. + * So if we have upper->rb_node populated, this means a cache + * hit. We only need to link the edge, as @upper and all its + * parents have already been linked. + */ + 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; + } + + /* Sanity check, we shouldn't have any unchecked nodes */ + if (!upper->checked) { + ASSERT(0); + return -EUCLEAN; + } + + /* Sanity check, COW-only node has non-COW-only parent */ + if (start->cowonly != upper->cowonly) { + ASSERT(0); + return -EUCLEAN; + } + + /* Only cache non-COW-only (subvolume trees) tree blocks */ + if (!upper->cowonly) { + rb_node = rb_simple_insert(&cache->rb_root, upper->bytenr, + &upper->rb_node); + if (rb_node) { + btrfs_backref_panic(cache->fs_info, + upper->bytenr, -EEXIST); + return -EUCLEAN; + } + } + + list_add_tail(&edge->list[UPPER], &upper->lower); + + /* + * Also queue all the parent edges of this uncached node + * to finish the upper linkage + */ + list_for_each_entry(edge, &upper->upper, list[LOWER]) + list_add_tail(&edge->list[UPPER], &pending_edge); + } + return 0; +} diff --git a/fs/btrfs/backref.h b/fs/btrfs/backref.h index 5839da215ff6247104d1d5d2f5debbc8c53f9772..80a43359d216b870581c3faba958641331385eba 100644 --- a/fs/btrfs/backref.h +++ b/fs/btrfs/backref.h @@ -369,4 +369,7 @@ int btrfs_backref_add_tree_node(struct btrfs_backref_cache *cache, struct btrfs_key *node_key, struct btrfs_backref_node *cur); +int btrfs_backref_finish_upper_links(struct btrfs_backref_cache *cache, + struct btrfs_backref_node *start); + #endif diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c index 275e4c9e96855cd03341520f09ed58d3242e89dc..a3e63b937290adb36980cf6a5a355f148eec4fc0 100644 --- a/fs/btrfs/relocation.c +++ b/fs/btrfs/relocation.c @@ -377,120 +377,6 @@ static struct btrfs_root *read_fs_root(struct btrfs_fs_info *fs_info, return btrfs_get_fs_root(fs_info, &key, false); } -/* - * In handle_one_tree_backref(), we have only linked the lower node to the edge, - * but the upper node hasn't been linked to the edge. - * This means we can only iterate through btrfs_backref_node::upper to reach - * parent edges, but not through btrfs_backref_node::lower to reach children - * edges. - * - * This function will finish the btrfs_backref_node::lower to related edges, - * so that backref cache can be bi-directionally iterated. - * - * Also, this will add the nodes to backref cache for the next run. - */ -static int finish_upper_links(struct btrfs_backref_cache *cache, - struct btrfs_backref_node *start) -{ - struct list_head *useless_node = &cache->useless_node; - struct btrfs_backref_edge *edge; - struct rb_node *rb_node; - LIST_HEAD(pending_edge); - - ASSERT(start->checked); - - /* Insert this node to cache if it's not COW-only */ - if (!start->cowonly) { - rb_node = rb_simple_insert(&cache->rb_root, start->bytenr, - &start->rb_node); - if (rb_node) - btrfs_backref_panic(cache->fs_info, start->bytenr, - -EEXIST); - list_add_tail(&start->lower, &cache->leaves); - } - - /* - * Use breadth first search to iterate all related edges. - * - * The starting points are all the edges of this node - */ - list_for_each_entry(edge, &start->upper, list[LOWER]) - list_add_tail(&edge->list[UPPER], &pending_edge); - - while (!list_empty(&pending_edge)) { - struct btrfs_backref_node *upper; - struct btrfs_backref_node *lower; - struct rb_node *rb_node; - - edge = list_first_entry(&pending_edge, - struct btrfs_backref_edge, list[UPPER]); - list_del_init(&edge->list[UPPER]); - upper = edge->node[UPPER]; - lower = edge->node[LOWER]; - - /* Parent is detached, no need to keep any edges */ - if (upper->detached) { - list_del(&edge->list[LOWER]); - btrfs_backref_free_edge(cache, edge); - - /* Lower node is orphan, queue for cleanup */ - if (list_empty(&lower->upper)) - list_add(&lower->list, useless_node); - continue; - } - - /* - * All new nodes added in current build_backref_tree() haven't - * been linked to the cache rb tree. - * So if we have upper->rb_node populated, this means a cache - * hit. We only need to link the edge, as @upper and all its - * parent have already been linked. - */ - 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; - } - - /* Sanity check, we shouldn't have any unchecked nodes */ - if (!upper->checked) { - ASSERT(0); - return -EUCLEAN; - } - - /* Sanity check, COW-only node has non-COW-only parent */ - if (start->cowonly != upper->cowonly) { - ASSERT(0); - return -EUCLEAN; - } - - /* Only cache non-COW-only (subvolume trees) tree blocks */ - if (!upper->cowonly) { - rb_node = rb_simple_insert(&cache->rb_root, upper->bytenr, - &upper->rb_node); - if (rb_node) { - btrfs_backref_panic(cache->fs_info, - upper->bytenr, -EEXIST); - return -EUCLEAN; - } - } - - list_add_tail(&edge->list[UPPER], &upper->lower); - - /* - * Also queue all the parent edges of this uncached node to - * finish the upper linkage - */ - list_for_each_entry(edge, &upper->upper, list[LOWER]) - list_add_tail(&edge->list[UPPER], &pending_edge); - } - return 0; -} - /* * For useless nodes, do two major clean ups: * @@ -634,7 +520,7 @@ static noinline_for_stack struct btrfs_backref_node *build_backref_tree( } while (edge); /* Finish the upper linkage of newly added edges/nodes */ - ret = finish_upper_links(cache, node); + ret = btrfs_backref_finish_upper_links(cache, node); if (ret < 0) { err = ret; goto out;