LU-14048 obd: fix race between connect vs disconnect

[fs/lustre-release.git] / lustre / ldlm / ldlm_lib.c

diff --git a/lustre/ldlm/ldlm_lib.c b/lustre/ldlm/ldlm_lib.c
index b0eea47..7dcba13 100644 (file)
--- a/lustre/ldlm/ldlm_lib.c
+++ b/lustre/ldlm/ldlm_lib.c
@@ -1097,6 +1097,7 @@ int target_handle_connect(struct ptlrpc_request *req)
        struct obd_connect_data *data, *tmpdata;
        int size, tmpsize;
        lnet_nid_t *client_nid = NULL;
+       struct ptlrpc_connection *pcon = NULL;
 
        ENTRY;
 
@@ -1476,7 +1477,16 @@ dont_check_exports:
         */
        ptlrpc_request_change_export(req, export);
 
+       pcon = ptlrpc_connection_get(req->rq_peer, req->rq_self, &cluuid);
+       if (pcon == NULL)
+               GOTO(out, rc = -ENOTCONN);
+
        spin_lock(&export->exp_lock);
+
+       if (export->exp_disconnected) {
+               spin_unlock(&export->exp_lock);
+               GOTO(out, rc = -ENODEV);
+       }
        if (export->exp_conn_cnt >= lustre_msg_get_conn_cnt(req->rq_reqmsg)) {
                spin_unlock(&export->exp_lock);
                CDEBUG(D_RPCTRACE,
@@ -1489,24 +1499,23 @@ dont_check_exports:
        }
        LASSERT(lustre_msg_get_conn_cnt(req->rq_reqmsg) > 0);
        export->exp_conn_cnt = lustre_msg_get_conn_cnt(req->rq_reqmsg);
-       spin_unlock(&export->exp_lock);
-
-       if (export->exp_connection != NULL) {
-               /* Check to see if connection came from another NID. */
-               if (export->exp_connection->c_peer.nid != req->rq_peer.nid)
-                       obd_nid_del(export->exp_obd, export);
 
+       /* Check to see if connection came from another NID. */
+       if (export->exp_connection != NULL &&
+           export->exp_connection->c_peer.nid != req->rq_peer.nid) {
+               obd_nid_del(export->exp_obd, export);
                ptlrpc_connection_put(export->exp_connection);
+               export->exp_connection = NULL;
        }
 
-       export->exp_connection = ptlrpc_connection_get(req->rq_peer,
-                                                      req->rq_self,
-                                                      &cluuid);
-       if (!export->exp_connection)
-               GOTO(out, rc = -ENOTCONN);
-
+       if (export->exp_connection == NULL) {
+               export->exp_connection = pcon;
+               pcon = NULL;
+       }
        obd_nid_add(export->exp_obd, export);
 
+       spin_unlock(&export->exp_lock);
+
        lustre_msg_set_handle(req->rq_repmsg, &conn);
 
        rc = rev_import_reconnect(export, req);
@@ -1582,6 +1591,8 @@ out:
                spin_unlock(&target->obd_dev_lock);
                class_decref(target, "find", current);
        }
+       if (pcon)
+               ptlrpc_connection_put(pcon);
        req->rq_status = rc;
        RETURN(rc);
 }