If the ceph_mdsc_open_export_target_session() return fails, we should add mutex_lock(&session->s_mutex) on IS_ERR(tsession) block to avoid twice unlocking. because the session->s_mutex will be unlock at the out_unlock lable. -- v2 -> v3: - Rewrite solution, adding a mutex_lock(&session->s_mutex) to the IS_ERR(tsession) block. - Modify the comment more clearly. v1 -> v2: - add spin_lock(&ci->i_ceph_lock) before goto out_unlock lable Signed-off-by: Wu Bo <wubo40@xxxxxxxxxx> --- fs/ceph/caps.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 185db76..d27d778 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -3746,6 +3746,7 @@ 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; -- 1.8.3.1