[PATCH AUTOSEL 5.4 32/49] ceph: fix double unlock in handle_cap_export()

* [PATCH AUTOSEL 5.4 32/49] ceph: fix double unlock in handle_cap_export()
       [not found] <20200514185311.20294-1-sashal@kernel.org>
@ 2020-05-14 18:52 ` Sasha Levin
  0 siblings, 0 replies; only message in thread
From: Sasha Levin @ 2020-05-14 18:52 UTC (permalink / raw)
  To: linux-kernel, stable
  Cc: Wu Bo, Yan, Zheng, Ilya Dryomov, Sasha Levin, ceph-devel

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 703945cce0e5d..2d602c2b0ff68 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -3693,6 +3693,7 @@ 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;
 
-- 
2.20.1

^ permalink raw reply related	[flat|nested] only message in thread