LU-4499 nrs: adjust the order of REQ NRS initilization

[fs/lustre-release.git] / lustre / ptlrpc / nrs.c

diff --git a/lustre/ptlrpc/nrs.c b/lustre/ptlrpc/nrs.c
index 205762e..1b07c8a 100644 (file)
--- a/lustre/ptlrpc/nrs.c
+++ b/lustre/ptlrpc/nrs.c
@@ -239,8 +239,23 @@ static int nrs_policy_start_locked(struct ptlrpc_nrs_policy *policy, char *arg)
                if (nrs->nrs_policy_fallback == NULL)
                        RETURN(-EPERM);
 
-               if (policy->pol_state == NRS_POL_STATE_STARTED)
-                       RETURN(0);
+               if (policy->pol_state == NRS_POL_STATE_STARTED) {
+                       /**
+                        * If the policy argument now is different from the last time,
+                        * stop the policy first and start it again with the new
+                        * argument.
+                        */
+                       if ((arg != NULL) && (strlen(arg) >= NRS_POL_ARG_MAX))
+                               return -EINVAL;
+
+                       if ((arg == NULL && strlen(policy->pol_arg) == 0) ||
+                           (arg != NULL && strcmp(policy->pol_arg, arg) == 0))
+                               RETURN(0);
+
+                       rc = nrs_policy_stop_locked(policy);
+                       if (rc)
+                               RETURN(-EAGAIN);
+               }
        }
 
        /**
@@ -255,6 +270,14 @@ static int nrs_policy_start_locked(struct ptlrpc_nrs_policy *policy, char *arg)
                RETURN(-ENODEV);
        }
 
+       if (arg != NULL) {
+               if (strlen(arg) + 1 > sizeof(policy->pol_arg)) {
+                       CERROR("NRS: arg '%s' is too long\n", arg);
+                       GOTO(out, rc = -E2BIG);
+               }
+               strncpy(policy->pol_arg, arg, sizeof(policy->pol_arg));
+       }
+
        /**
         * Serialize policy starting across the NRS head
         */