staging: lustre: reject invalid net configuration for lnet

Currently if there exists a route that goes over a
remote net and then this net is added dynamically as
a local net, then traffic stops because the code in
lnet_send() determines that the destination nid
can be reached from another local_ni, but the src_nid
is still stuck on the earlier NI, because the src_nid
is stored in the ptlrpc layer and is not updated
when a local NI is configured.

Signed-off-by: Amir Shehata <amir.shehata@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-5874
Reviewed-on: http://review.whamcloud.com/12912
Reviewed-by: Isaac Huang <he.huang@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/lustre/lnet/lnet/api-ni.c b/drivers/staging/lustre/lnet/lnet/api-ni.c
index 9497ce1cb4589425596640d4012c23909d0c16c2..62a9e45dfe54dbb51875d618b674444604142056 100644 (file)
--- a/drivers/staging/lustre/lnet/lnet/api-ni.c
+++ b/drivers/staging/lustre/lnet/lnet/api-ni.c
@@ -1756,6 +1756,7 @@ lnet_dyn_add_ni(lnet_pid_t requested_pid, char *nets,
        lnet_handle_md_t md_handle;
        struct lnet_ni *ni;
        struct list_head net_head;
+       lnet_remotenet_t *rnet;
        int rc;
 
        INIT_LIST_HEAD(&net_head);
@@ -1772,12 +1773,27 @@ lnet_dyn_add_ni(lnet_pid_t requested_pid, char *nets,
                goto failed0;
        }
 
+       ni = list_entry(net_head.next, struct lnet_ni, ni_list);
+
+       lnet_net_lock(LNET_LOCK_EX);
+       rnet = lnet_find_net_locked(LNET_NIDNET(ni->ni_nid));
+       lnet_net_unlock(LNET_LOCK_EX);
+       /*
+        * make sure that the net added doesn't invalidate the current
+        * configuration LNet is keeping
+        */
+       if (rnet) {
+               CERROR("Adding net %s will invalidate routing configuration\n",
+                      nets);
+               rc = -EUSERS;
+               goto failed0;
+       }
+
        rc = lnet_ping_info_setup(&pinfo, &md_handle, 1 + lnet_get_ni_count(),
                                  false);
        if (rc)
                goto failed0;
 
-       ni = list_entry(net_head.next, struct lnet_ni, ni_list);
        list_del_init(&ni->ni_list);
 
        rc = lnet_startup_lndni(ni, peer_timeout, peer_cr,