[PATCH AUTOSEL 5.6 123/606] ceph: fix double unlock in handle_cap_export()

Sasha Levin
2020-06-08T23:18:20Z

From: Wu Bo <wubo40@huawei.com>

[ Upstream commit 4d8e28ff3106b093d98bfd2eceb9b430c70a8758 ]

If the ceph_mdsc_open_export_target_session() return fails, it will
do a "goto retry", but the session mutex has already been unlocked.
Re-lock the mutex in that case to ensure that we don't unlock it
twice.

Signed-off-by: Wu Bo <wubo40@huawei.com>
Reviewed-by: "Yan, Zheng" <zyan@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/ceph/caps.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index d050acc1fd5d..f50204380a65 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -3707,6 +3707,7 @@ static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
WARN_ON(1);
tsession = NULL;
target = -1;
+ mutex_lock(&session->s_mutex);
}
goto retry;

--
2.25.1