if the ceph_mdsc_open_export_target_session() return fails, should add a lock to avoid twice unlocking. Because the lock will be released at the retry or out_unlock tag. -- v1 -> v2: add spin_lock(&ci->i_ceph_lock) before goto out_unlock tag. Signed-off-by: Wu Bo <wubo40@xxxxxxxxxx> --- fs/ceph/caps.c | 27 +++++++++++++++------------ 1 file changed, 15 insertions(+), 12 deletions(-) diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c index 185db76..414c0e2 100644 --- a/fs/ceph/caps.c +++ b/fs/ceph/caps.c @@ -3731,22 +3731,25 @@ static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex, /* open target session */ tsession = ceph_mdsc_open_export_target_session(mdsc, target); - if (!IS_ERR(tsession)) { - if (mds > target) { - mutex_lock(&session->s_mutex); - mutex_lock_nested(&tsession->s_mutex, - SINGLE_DEPTH_NESTING); - } else { - mutex_lock(&tsession->s_mutex); - mutex_lock_nested(&session->s_mutex, - SINGLE_DEPTH_NESTING); - } - new_cap = ceph_get_cap(mdsc, NULL); - } else { + if (IS_ERR(tsession)) { WARN_ON(1); tsession = NULL; target = -1; + mutex_lock(&session->s_mutex); + spin_lock(&ci->i_ceph_lock); + goto out_unlock; + } + + if (mds > target) { + mutex_lock(&session->s_mutex); + mutex_lock_nested(&tsession->s_mutex, + SINGLE_DEPTH_NESTING); + } else { + mutex_lock(&tsession->s_mutex); + mutex_lock_nested(&session->s_mutex, + SINGLE_DEPTH_NESTING); } + new_cap = ceph_get_cap(mdsc, NULL); goto retry; out_unlock: -- 1.8.3.1