LU-13116 ptlrpc: return error for conn with NULL export

In import_select_connection(), instead of asserting when export on
chosen connection is NULL, return an error.

Signed-off-by: Sebastien Buisson <sbuisson@ddn.com>
Change-Id: I60dcb26693f2ba177d612ded7efff9721febf601
Reviewed-on: https://review.whamcloud.com/37251
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-by: James Simmons <jsimmons@infradead.org>
Reviewed-by: Mike Pershin <mpershin@whamcloud.com>
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>

diff --git a/lustre/ptlrpc/import.c b/lustre/ptlrpc/import.c
index 1573efa..edb3f66 100644 (file)
--- a/lustre/ptlrpc/import.c
+++ b/lustre/ptlrpc/import.c
@@ -521,59 +521,63 @@ EXPORT_SYMBOL(ptlrpc_reconnect_import);
  */
 static int import_select_connection(struct obd_import *imp)
 {
-        struct obd_import_conn *imp_conn = NULL, *conn;
-        struct obd_export *dlmexp;
-        char *target_start;
-        int target_len, tried_all = 1;
-        ENTRY;
+       struct obd_import_conn *imp_conn = NULL, *conn;
+       struct obd_export *dlmexp;
+       char *target_start;
+       int target_len, tried_all = 1;
+       int rc = 0;
+       ENTRY;
 
        spin_lock(&imp->imp_lock);
 
        if (list_empty(&imp->imp_conn_list)) {
-               CERROR("%s: no connections available\n",
-                      imp->imp_obd->obd_name);
-               spin_unlock(&imp->imp_lock);
-               RETURN(-EINVAL);
+               rc = -EINVAL;
+               CERROR("%s: no connections available: rc = %d\n",
+                      imp->imp_obd->obd_name, rc);
+               GOTO(out_unlock, rc);
        }
 
        list_for_each_entry(conn, &imp->imp_conn_list, oic_item) {
                CDEBUG(D_HA, "%s: connect to NID %s last attempt %lld\n",
-                       imp->imp_obd->obd_name,
-                       libcfs_nid2str(conn->oic_conn->c_peer.nid),
-                       conn->oic_last_attempt);
+                      imp->imp_obd->obd_name,
+                      libcfs_nid2str(conn->oic_conn->c_peer.nid),
+                      conn->oic_last_attempt);
 
-                /* If we have not tried this connection since
-                   the last successful attempt, go with this one */
-                if ((conn->oic_last_attempt == 0) ||
+               /* If we have not tried this connection since
+                * the last successful attempt, go with this one
+                */
+               if ((conn->oic_last_attempt == 0) ||
                    conn->oic_last_attempt <= imp->imp_last_success_conn) {
-                        imp_conn = conn;
-                        tried_all = 0;
-                        break;
-                }
+                       imp_conn = conn;
+                       tried_all = 0;
+                       break;
+               }
 
-                /* If all of the connections have already been tried
-                   since the last successful connection; just choose the
-                   least recently used */
-                if (!imp_conn)
-                        imp_conn = conn;
+               /* If all of the connections have already been tried
+                * since the last successful connection; just choose the
+                * least recently used
+                */
+               if (!imp_conn)
+                       imp_conn = conn;
                else if (imp_conn->oic_last_attempt > conn->oic_last_attempt)
-                        imp_conn = conn;
-        }
+                       imp_conn = conn;
+       }
 
-        /* if not found, simply choose the current one */
-        if (!imp_conn || imp->imp_force_reconnect) {
-                LASSERT(imp->imp_conn_current);
-                imp_conn = imp->imp_conn_current;
-                tried_all = 0;
-        }
-        LASSERT(imp_conn->oic_conn);
-
-        /* If we've tried everything, and we're back to the beginning of the
-           list, increase our timeout and try again. It will be reset when
-           we do finally connect. (FIXME: really we should wait for all network
-           state associated with the last connection attempt to drain before
-           trying to reconnect on it.) */
-        if (tried_all && (imp->imp_conn_list.next == &imp_conn->oic_item)) {
+       /* if not found, simply choose the current one */
+       if (!imp_conn || imp->imp_force_reconnect) {
+               LASSERT(imp->imp_conn_current);
+               imp_conn = imp->imp_conn_current;
+               tried_all = 0;
+       }
+       LASSERT(imp_conn->oic_conn);
+
+       /* If we've tried everything, and we're back to the beginning of the
+        * list, increase our timeout and try again. It will be reset when
+        * we do finally connect. (FIXME: really we should wait for all network
+        * state associated with the last connection attempt to drain before
+        * trying to reconnect on it.)
+        */
+       if (tried_all && (imp->imp_conn_list.next == &imp_conn->oic_item)) {
                struct adaptive_timeout *at = &imp->imp_at.iat_net_latency;
                if (at_get(at) < CONNECTION_SWITCH_MAX) {
                        at_measured(at, at_get(at) + CONNECTION_SWITCH_INC);
@@ -582,46 +586,47 @@ static int import_select_connection(struct obd_import *imp)
                }
                LASSERT(imp_conn->oic_last_attempt);
                CDEBUG(D_HA, "%s: tried all connections, increasing latency "
-                       "to %ds\n", imp->imp_obd->obd_name, at_get(at));
+                      "to %ds\n", imp->imp_obd->obd_name, at_get(at));
        }
 
        imp_conn->oic_last_attempt = ktime_get_seconds();
 
-        /* switch connection, don't mind if it's same as the current one */
-        if (imp->imp_connection)
-                ptlrpc_connection_put(imp->imp_connection);
-        imp->imp_connection = ptlrpc_connection_addref(imp_conn->oic_conn);
-
-        dlmexp =  class_conn2export(&imp->imp_dlm_handle);
-        LASSERT(dlmexp != NULL);
-        if (dlmexp->exp_connection)
-                ptlrpc_connection_put(dlmexp->exp_connection);
-        dlmexp->exp_connection = ptlrpc_connection_addref(imp_conn->oic_conn);
-        class_export_put(dlmexp);
-
-        if (imp->imp_conn_current != imp_conn) {
-                if (imp->imp_conn_current) {
-                        deuuidify(obd2cli_tgt(imp->imp_obd), NULL,
-                                  &target_start, &target_len);
-
-                        CDEBUG(D_HA, "%s: Connection changing to"
-                               " %.*s (at %s)\n",
-                               imp->imp_obd->obd_name,
-                               target_len, target_start,
-                               libcfs_nid2str(imp_conn->oic_conn->c_peer.nid));
-                }
+       /* switch connection, don't mind if it's same as the current one */
+       if (imp->imp_connection)
+               ptlrpc_connection_put(imp->imp_connection);
+       imp->imp_connection = ptlrpc_connection_addref(imp_conn->oic_conn);
+
+       dlmexp = class_conn2export(&imp->imp_dlm_handle);
+       if (!dlmexp)
+               GOTO(out_unlock, rc = -EINVAL);
+       if (dlmexp->exp_connection)
+               ptlrpc_connection_put(dlmexp->exp_connection);
+       dlmexp->exp_connection = ptlrpc_connection_addref(imp_conn->oic_conn);
+       class_export_put(dlmexp);
+
+       if (imp->imp_conn_current != imp_conn) {
+               if (imp->imp_conn_current) {
+                       deuuidify(obd2cli_tgt(imp->imp_obd), NULL,
+                                 &target_start, &target_len);
+
+                       CDEBUG(D_HA, "%s: Connection changing to"
+                              " %.*s (at %s)\n",
+                              imp->imp_obd->obd_name,
+                              target_len, target_start,
+                              libcfs_nid2str(imp_conn->oic_conn->c_peer.nid));
+               }
 
-                imp->imp_conn_current = imp_conn;
-        }
+               imp->imp_conn_current = imp_conn;
+       }
 
        /* The below message is checked in conf-sanity.sh test_35[ab] */
-        CDEBUG(D_HA, "%s: import %p using connection %s/%s\n",
-               imp->imp_obd->obd_name, imp, imp_conn->oic_uuid.uuid,
-               libcfs_nid2str(imp_conn->oic_conn->c_peer.nid));
+       CDEBUG(D_HA, "%s: import %p using connection %s/%s\n",
+              imp->imp_obd->obd_name, imp, imp_conn->oic_uuid.uuid,
+              libcfs_nid2str(imp_conn->oic_conn->c_peer.nid));
 
+out_unlock:
        spin_unlock(&imp->imp_lock);
-
-       RETURN(0);
+       RETURN(rc);
 }
 
 /*