diff options
| -rw-r--r-- | fs/btrfs/ctree.c | 88 |
1 files changed, 65 insertions, 23 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 271b05e507d7..b8082762ca78 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -4127,28 +4127,44 @@ next: int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) { int slot; - int level = 1; + int level; struct extent_buffer *c; - struct extent_buffer *next = NULL; + struct extent_buffer *next; struct btrfs_key key; u32 nritems; int ret; + int old_spinning = path->leave_spinning; + int force_blocking = 0; nritems = btrfs_header_nritems(path->nodes[0]); if (nritems == 0) return 1; - btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); + /* + * we take the blocks in an order that upsets lockdep. Using + * blocking mode is the only way around it. + */ +#ifdef CONFIG_DEBUG_LOCK_ALLOC + force_blocking = 1; +#endif + btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); +again: + level = 1; + next = NULL; btrfs_release_path(root, path); + path->keep_locks = 1; + + if (!force_blocking) + path->leave_spinning = 1; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); path->keep_locks = 0; if (ret < 0) return ret; - btrfs_set_path_blocking(path); nritems = btrfs_header_nritems(path->nodes[0]); /* * by releasing the path above we dropped all our locks. A balance @@ -4158,19 +4174,24 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) */ if (nritems > 0 && path->slots[0] < nritems - 1) { path->slots[0]++; + ret = 0; goto done; } while (level < BTRFS_MAX_LEVEL) { - if (!path->nodes[level]) - return 1; + if (!path->nodes[level]) { + ret = 1; + goto done; + } slot = path->slots[level] + 1; c = path->nodes[level]; if (slot >= btrfs_header_nritems(c)) { level++; - if (level == BTRFS_MAX_LEVEL) - return 1; + if (level == BTRFS_MAX_LEVEL) { + ret = 1; + goto done; + } continue; } @@ -4179,16 +4200,22 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) free_extent_buffer(next); } - /* the path was set to blocking above */ - if (level == 1 && (path->locks[1] || path->skip_locking) && - path->reada) - reada_for_search(root, path, level, slot, 0); + next = c; + ret = read_block_for_search(NULL, root, path, &next, level, + slot, &key); + if (ret == -EAGAIN) + goto again; - next = read_node_slot(root, c, slot); if (!path->skip_locking) { - btrfs_assert_tree_locked(c); - btrfs_tree_lock(next); - btrfs_set_lock_blocking(next); + ret = btrfs_try_spin_lock(next); + if (!ret) { + btrfs_set_path_blocking(path); + btrfs_tree_lock(next); + if (!force_blocking) + btrfs_clear_path_blocking(path, next); + } + if (force_blocking) + btrfs_set_lock_blocking(next); } break; } @@ -4198,27 +4225,42 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) c = path->nodes[level]; if (path->locks[level]) btrfs_tree_unlock(c); + free_extent_buffer(c); path->nodes[level] = next; path->slots[level] = 0; if (!path->skip_locking) path->locks[level] = 1; + if (!level) break; - btrfs_set_path_blocking(path); - if (level == 1 && path->locks[1] && path->reada) - reada_for_search(root, path, level, slot, 0); - next = read_node_slot(root, next, 0); + ret = read_block_for_search(NULL, root, path, &next, level, + 0, &key); + if (ret == -EAGAIN) + goto again; + if (!path->skip_locking) { btrfs_assert_tree_locked(path->nodes[level]); - btrfs_tree_lock(next); - btrfs_set_lock_blocking(next); + ret = btrfs_try_spin_lock(next); + if (!ret) { + btrfs_set_path_blocking(path); + btrfs_tree_lock(next); + if (!force_blocking) + btrfs_clear_path_blocking(path, next); + } + if (force_blocking) + btrfs_set_lock_blocking(next); } } + ret = 0; done: unlock_up(path, 0, 1); - return 0; + path->leave_spinning = old_spinning; + if (!old_spinning) + btrfs_set_path_blocking(path); + + return ret; } /* |