[PATCH 4.14-openela 005/190] btrfs: fix extent buffer leak after tree mod log failure at split_node()

[Sasha Levin <sashal@kernel.org>]

From: Filipe Manana <fdmanana@suse.com>

[ Upstream commit ede600e497b1461d06d22a7d17703d9096868bc3 ]

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: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/ctree.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index 156716f9e3e21..61ed69c688d58 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -3537,6 +3537,8 @@ static noinline int split_node(struct btrfs_trans_handle *trans,
 
 	ret = tree_mod_log_eb_copy(fs_info, split, c, 0, mid, c_nritems - mid);
 	if (ret) {
+		btrfs_tree_unlock(split);
+		free_extent_buffer(split);
 		btrfs_abort_transaction(trans, ret);
 		return ret;
 	}
-- 
2.43.0