ceph: Hold caps_list_lock when adjusting caps_{use, total}_count

Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: NSage Weil <sage@inktank.com>

fs/ceph/caps.c

@@ -236,8 +236,10 @@ static struct ceph_cap *get_cap(struct ceph_mds_client *mdsc,
 	if (!ctx) {
 		cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
 		if (cap) {
+			spin_lock(&mdsc->caps_list_lock);
 			mdsc->caps_use_count++;
 			mdsc->caps_total_count++;
+			spin_unlock(&mdsc->caps_list_lock);
 		}
 		return cap;
 	}