From: Wu Bo <wubo40@huawei.com>
Date: Thu, 30 Apr 2020 06:12:49 +0000 (+0800)
Subject: ceph: fix double unlock in handle_cap_export()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4d8e28ff3106b093d98bfd2eceb9b430c70a8758;p=linux.git

ceph: fix double unlock in handle_cap_export()

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>
---

diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
index 1a8e20ef35bf6..5f3aa4d607def 100644
--- a/fs/ceph/caps.c
+++ b/fs/ceph/caps.c
@@ -3746,6 +3746,7 @@ retry:
 		WARN_ON(1);
 		tsession = NULL;
 		target = -1;
+		mutex_lock(&session->s_mutex);
 	}
 	goto retry;