LU-2031 obdclass: check if client is connected to the target

When the client is notified by IR, it may not connect to the OST
yet, verify it before writing the new NID to the import.

Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Change-Id: Ia144b695443a9850ecccd0c8946de029492b4446
Reviewed-on: http://review.whamcloud.com/4525
Tested-by: Hudson
Tested-by: Maloo <whamcloud.maloo@gmail.com>
Reviewed-by: Niu Yawei <niu@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/mgc/mgc_request.c b/lustre/mgc/mgc_request.c
index bf02e4e..e293fa0 100644 (file)
--- a/lustre/mgc/mgc_request.c
+++ b/lustre/mgc/mgc_request.c
@@ -1371,11 +1371,20 @@ static int mgc_apply_recover_logs(struct obd_device *mgc,
                 pos += sprintf(params, "%s.import=%s", cname, "connection=");
                 uuid = buf + pos;
 
+               cfs_down_read(&obd->u.cli.cl_sem);
+               if (obd->u.cli.cl_import == NULL) {
+                       /* client does not connect to the OST yet */
+                       cfs_up_read(&obd->u.cli.cl_sem);
+                       rc = 0;
+                       continue;
+               }
+
                 /* TODO: iterate all nids to find one */
                 /* find uuid by nid */
                 rc = client_import_find_conn(obd->u.cli.cl_import,
                                              entry->u.nids[0],
                                              (struct obd_uuid *)uuid);
+               cfs_up_read(&obd->u.cli.cl_sem);
                 if (rc < 0) {
                         CERROR("mgc: cannot find uuid by nid %s\n",
                                libcfs_nid2str(entry->u.nids[0]));