diff options
Diffstat (limited to 'fs/btrfs/uuid-tree.c')
| -rw-r--r-- | fs/btrfs/uuid-tree.c | 38 |
1 files changed, 38 insertions, 0 deletions
diff --git a/fs/btrfs/uuid-tree.c b/fs/btrfs/uuid-tree.c index f24c14b9bb2f..43c17a1d3451 100644 --- a/fs/btrfs/uuid-tree.c +++ b/fs/btrfs/uuid-tree.c @@ -199,6 +199,44 @@ int btrfs_uuid_tree_remove(struct btrfs_trans_handle *trans, const u8 *uuid, u8 return 0; } +/* + * Check if we can add one root ID to a UUID key. + * If the key does not yet exists, we can, otherwise only if extended item does + * not exceeds the maximum item size permitted by the leaf size. + * + * Returns 0 on success, negative value on error. + */ +int btrfs_uuid_tree_check_overflow(struct btrfs_fs_info *fs_info, + const u8 *uuid, u8 type) +{ + BTRFS_PATH_AUTO_FREE(path); + int ret; + u32 item_size; + struct btrfs_key key; + + if (WARN_ON_ONCE(!fs_info->uuid_root)) + return -EINVAL; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + btrfs_uuid_to_key(uuid, type, &key); + ret = btrfs_search_slot(NULL, fs_info->uuid_root, &key, path, 0, 0); + if (ret < 0) + return ret; + if (ret > 0) + return 0; + + item_size = btrfs_item_size(path->nodes[0], path->slots[0]); + + if (sizeof(struct btrfs_item) + item_size + sizeof(u64) > + BTRFS_LEAF_DATA_SIZE(fs_info)) + return -EOVERFLOW; + + return 0; +} + static int btrfs_uuid_iter_rem(struct btrfs_root *uuid_root, u8 *uuid, u8 type, u64 subid) { |