[PATCH 6.1.y] xfs: fix a resource leak in xfs_alloc_buftarg()

[Sasha Levin <sashal@kernel.org>]

From: Haoxiang Li <lihaoxiang@isrc.iscas.ac.cn>

[ Upstream commit 29a7b2614357393b176ef06ba5bc3ff5afc8df69 ]

In the error path, call fs_put_dax() to drop the DAX
device reference.

Fixes: 6f643c57d57c ("xfs: implement ->notify_failure() for XFS")
Cc: stable@vger.kernel.org
Signed-off-by: Haoxiang Li <lihaoxiang@isrc.iscas.ac.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
[ kept `kmem_free(btp)` and `return NULL` instead of `kfree(btp)`/`ERR_PTR(error)` ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/xfs/xfs_buf.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c
index 257945cdf63b8..34e476301342c 100644
--- a/fs/xfs/xfs_buf.c
+++ b/fs/xfs/xfs_buf.c
@@ -2036,6 +2036,7 @@ xfs_alloc_buftarg(
 error_lru:
 	list_lru_destroy(&btp->bt_lru);
 error_free:
+	fs_put_dax(btp->bt_daxdev, mp);
 	kmem_free(btp);
 	return NULL;
 }
-- 
2.53.0