LU-7848 target: Do not fail MDT-MDT connection

When one MDT restarts, and try to connect to another
MDT with the new cookie, let's do not fail it, otherwise
it might cause eviction between MDT.

Signed-off-by: Di Wang <di.wang@intel.com>
Change-Id: I3d2e0712ee0ed05bdf46c7781e190206a6dcfb1c
Reviewed-on: http://review.whamcloud.com/18800
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Mike Pershin <mike.pershin@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>

diff --git a/lustre/ldlm/ldlm_lib.c b/lustre/ldlm/ldlm_lib.c
index 2a92a17..3aea6a2 100644 (file)
--- a/lustre/ldlm/ldlm_lib.c
+++ b/lustre/ldlm/ldlm_lib.c
@@ -1117,25 +1117,43 @@ int target_handle_connect(struct ptlrpc_request *req)
                class_export_put(export);
                export = NULL;
                rc = -EALREADY;
                class_export_put(export);
                export = NULL;
                rc = -EALREADY;

-       } else if ((mds_conn || lw_client) && export->exp_connection != NULL) {
+       } else if ((mds_conn || lw_client ||
+                   data->ocd_connect_flags & OBD_CONNECT_MDS_MDS) &&
+                  export->exp_connection != NULL) {

                spin_unlock(&export->exp_lock);
                spin_unlock(&export->exp_lock);

-               if (req->rq_peer.nid != export->exp_connection->c_peer.nid)
+               if (req->rq_peer.nid != export->exp_connection->c_peer.nid) {

                        /* MDS or LWP reconnected after failover. */
                        LCONSOLE_WARN("%s: Received %s connection from "
                            "%s, removing former export from %s\n",
                            target->obd_name, mds_conn ? "MDS" : "LWP",
                            libcfs_nid2str(req->rq_peer.nid),
                            libcfs_nid2str(export->exp_connection->c_peer.nid));
                        /* MDS or LWP reconnected after failover. */
                        LCONSOLE_WARN("%s: Received %s connection from "
                            "%s, removing former export from %s\n",
                            target->obd_name, mds_conn ? "MDS" : "LWP",
                            libcfs_nid2str(req->rq_peer.nid),
                            libcfs_nid2str(export->exp_connection->c_peer.nid));

-               else
+               } else {

                        /* New MDS connection from the same NID. */
                        LCONSOLE_WARN("%s: Received new %s connection from "
                                "%s, removing former export from same NID\n",
                                target->obd_name, mds_conn ? "MDS" : "LWP",
                                libcfs_nid2str(req->rq_peer.nid));
                        /* New MDS connection from the same NID. */
                        LCONSOLE_WARN("%s: Received new %s connection from "
                                "%s, removing former export from same NID\n",
                                target->obd_name, mds_conn ? "MDS" : "LWP",
                                libcfs_nid2str(req->rq_peer.nid));

-                class_fail_export(export);
-                class_export_put(export);
-                export = NULL;
-                rc = 0;
+               }
+
+               if (req->rq_peer.nid == export->exp_connection->c_peer.nid &&
+                   data->ocd_connect_flags & OBD_CONNECT_MDS_MDS) {
+                       /* Because exports between MDTs will always be
+                        * kept, let's do not fail such export if they
+                        * come from the same NID, otherwise it might
+                        * cause eviction between MDTs, which might
+                        * cause namespace inconsistency */
+                       spin_lock(&export->exp_lock);
+                       export->exp_connecting = 1;
+                       spin_unlock(&export->exp_lock);
+                       conn.cookie = export->exp_handle.h_cookie;
+                       rc = EALREADY;
+               } else {
+                       class_fail_export(export);
+                       class_export_put(export);
+                       export = NULL;
+                       rc = 0;
+               }

         } else if (export->exp_connection != NULL &&
                    req->rq_peer.nid != export->exp_connection->c_peer.nid &&
                    (lustre_msg_get_op_flags(req->rq_reqmsg) &
         } else if (export->exp_connection != NULL &&
                    req->rq_peer.nid != export->exp_connection->c_peer.nid &&
                    (lustre_msg_get_op_flags(req->rq_reqmsg) &