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

commit ede600e497b1461d06d22a7d17703d9096868bc3 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 9a20b9e3ebd0ee03303a0d10b0cee12069b03bf8..9aed5c7c2734e93d99a0f64ef9fef047f26d4d0b 100644 (file)
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -2861,6 +2861,8 @@ 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;
        }