ceph: add more debug info when decoding mdsmap

Show the laggy state.
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

fs/ceph/mdsmap.c

@@ -158,6 +158,7 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
 		void *pexport_targets = NULL;
 		struct ceph_timespec laggy_since;
 		struct ceph_mds_info *info;
+		bool laggy;
 
 		ceph_decode_need(p, end, sizeof(u64) + 1, bad);
 		global_id = ceph_decode_64(p);
@@ -190,6 +191,7 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
 		if (err)
 			goto corrupt;
 		ceph_decode_copy(p, &laggy_since, sizeof(laggy_since));
+		laggy = laggy_since.tv_sec != 0 || laggy_since.tv_nsec != 0;
 		*p += sizeof(u32);
 		ceph_decode_32_safe(p, end, namelen, bad);
 		*p += namelen;
@@ -207,10 +209,11 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
 			*p = info_end;
 		}
 
-		dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s\n",
+		dout("mdsmap_decode %d/%d %lld mds%d.%d %s %s%s\n",
 		     i+1, n, global_id, mds, inc,
 		     ceph_pr_addr(&addr),
-		     ceph_mds_state_name(state));
+		     ceph_mds_state_name(state),
+		     laggy ? "(laggy)" : "");
 
 		if (mds < 0 || state <= 0)
 			continue;
@@ -230,8 +233,7 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
 		info->global_id = global_id;
 		info->state = state;
 		info->addr = addr;
-		info->laggy = (laggy_since.tv_sec != 0 ||
-			       laggy_since.tv_nsec != 0);
+		info->laggy = laggy;
 		info->num_export_targets = num_export_targets;
 		if (num_export_targets) {
 			info->export_targets = kcalloc(num_export_targets,
@@ -355,6 +357,8 @@ struct ceph_mdsmap *ceph_mdsmap_decode(void **p, void *end)
 		m->m_damaged = false;
 	}
 bad_ext:
+	dout("mdsmap_decode m_enabled: %d, m_damaged: %d, m_num_laggy: %d\n",
+	     !!m->m_enabled, !!m->m_damaged, m->m_num_laggy);
 	*p = end;
 	dout("mdsmap_decode success epoch %u\n", m->m_epoch);
 	return m;