diff options
Diffstat (limited to 'fs/btrfs/ctree.c')
| -rw-r--r-- | fs/btrfs/ctree.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index 0c5c28ff794f..e8b32641ea90 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -5490,6 +5490,139 @@ int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) return btrfs_next_old_leaf(root, path, 0); } +/* Release the path up to but not including the given level */ +static void btrfs_release_level(struct btrfs_path *path, int level) +{ + int i; + + for (i = 0; i < level; i++) { + path->slots[i] = 0; + if (!path->nodes[i]) + continue; + if (path->locks[i]) { + btrfs_tree_unlock_rw(path->nodes[i], path->locks[i]); + path->locks[i] = 0; + } + free_extent_buffer(path->nodes[i]); + path->nodes[i] = NULL; + } +} + +/* + * This function assumes 2 things + * + * 1) You are using path->keep_locks + * 2) You are not inserting items. + * + * If either of these are not true do not use this function. If you need a next + * leaf with either of these not being true then this function can be easily + * adapted to do that, but at the moment these are the limitations. + */ +int btrfs_next_leaf_write(struct btrfs_trans_handle *trans, + struct btrfs_root *root, struct btrfs_path *path, + int del) +{ + struct extent_buffer *b; + struct btrfs_key key; + u32 nritems; + int level = 1; + int slot; + int ret = 1; + int write_lock_level = BTRFS_MAX_LEVEL; + int ins_len = del ? -1 : 0; + + WARN_ON(!(path->keep_locks || path->really_keep_locks)); + + nritems = btrfs_header_nritems(path->nodes[0]); + btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); + + while (path->nodes[level]) { + nritems = btrfs_header_nritems(path->nodes[level]); + if (!(path->locks[level] & BTRFS_WRITE_LOCK)) { +search: + btrfs_release_path(path); + ret = btrfs_search_slot(trans, root, &key, path, + ins_len, 1); + if (ret < 0) + goto out; + level = 1; + continue; + } + + if (path->slots[level] >= nritems - 1) { + level++; + continue; + } + + btrfs_release_level(path, level); + break; + } + + if (!path->nodes[level]) { + ret = 1; + goto out; + } + + path->slots[level]++; + b = path->nodes[level]; + + while (b) { + level = btrfs_header_level(b); + + if (!should_cow_block(trans, root, b)) + goto cow_done; + + btrfs_set_path_blocking(path); + ret = btrfs_cow_block(trans, root, b, + path->nodes[level + 1], + path->slots[level + 1], &b); + if (ret) + goto out; +cow_done: + path->nodes[level] = b; + btrfs_clear_path_blocking(path, NULL, 0); + if (level != 0) { + ret = setup_nodes_for_search(trans, root, path, b, + level, ins_len, + &write_lock_level); + if (ret == -EAGAIN) + goto search; + if (ret) + goto out; + + b = path->nodes[level]; + slot = path->slots[level]; + + ret = read_block_for_search(trans, root, path, + &b, level, slot, &key, 0); + if (ret == -EAGAIN) + goto search; + if (ret) + goto out; + level = btrfs_header_level(b); + if (!btrfs_try_tree_write_lock(b)) { + btrfs_set_path_blocking(path); + btrfs_tree_lock(b); + btrfs_clear_path_blocking(path, b, + BTRFS_WRITE_LOCK); + } + path->locks[level] = BTRFS_WRITE_LOCK; + path->nodes[level] = b; + path->slots[level] = 0; + } else { + path->slots[level] = 0; + ret = 0; + break; + } + } + +out: + if (ret) + btrfs_release_path(path); + + return ret; +} + int btrfs_next_old_leaf(struct btrfs_root *root, struct btrfs_path *path, u64 time_seq) { |