get_old_root used used only by btrfs_search_old_slot to initialise the path structure. The old root is always a cloned buffer (either via alloc dummy or via btrfs_clone_extent_buffer) and its reference count is 2 - 1 from allocation 1 from extent_buffer_get call in get_old_root. This latter explicit ref count acquire operation is in fact unnecessary since the semantic is such that the newly allocated buffer is handed over to the btrfs_path for lifetime management. Considering this just remove the extra extent_buffer_get in get_old_root.
Signed-off-by: Nikolay Borisov <[email protected]> --- fs/btrfs/ctree.c | 1 - 1 file changed, 1 deletion(-) diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c index d436fb4c002e..4dc5d4becd49 100644 --- a/fs/btrfs/ctree.c +++ b/fs/btrfs/ctree.c @@ -1382,7 +1382,6 @@ get_old_root(struct btrfs_root *root, u64 time_seq) if (!eb) return NULL; - extent_buffer_get(eb); btrfs_tree_read_lock(eb); if (old_root) { btrfs_set_header_bytenr(eb, eb->start); -- 2.7.4
