btrfs: fix extent buffer leak after tree mod log failure at split_node()

At split_node(), if we fail to log the tree mod log copy operation, we
return without unlocking the split extent buffer we just allocated and
without decrementing the reference we own on it. Fix this by unlocking
it and decrementing the ref count before returning.

Fixes: 5de865eebb83 ("Btrfs: fix tree mod logging")
CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 7f7f13965fe9cb2e9a083fa579d4fc6dd78c9e87..8496535828de1001a518f43375213f404777f805 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -3053,6 +3053,8 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
 
        ret = btrfs_tree_mod_log_eb_copy(split, c, 0, mid, c_nritems - mid);
        if (ret) {
+               btrfs_tree_unlock(split);
+               free_extent_buffer(split);
                btrfs_abort_transaction(trans, ret);
                return ret;
        }