From: Amir Shehata <amir.shehata@intel.com>
Date: Tue, 2 Dec 2014 02:06:39 +0000 (-0800)
Subject: LU-5874 lnet: reject invalid net configuration
X-Git-Tag: 2.6.93~38
X-Git-Url: https://git.whamcloud.com/?p=fs%2Flustre-release.git;a=commitdiff_plain;h=4aebc21514f49453aeeca83c6f6279d473d61617

LU-5874 lnet: reject invalid net configuration

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>
Change-Id: Idd4ea9e131db127f541dd8d75b90ac509c16e2c3
Reviewed-on: http://review.whamcloud.com/12912
Tested-by: Jenkins
Reviewed-by: Isaac Huang <he.huang@intel.com>
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: James Simmons <uja.ornl@gmail.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
---

diff --git a/lnet/lnet/api-ni.c b/lnet/lnet/api-ni.c
index 75ff383..04ccd26 100644
--- a/lnet/lnet/api-ni.c
+++ b/lnet/lnet/api-ni.c
@@ -1992,6 +1992,7 @@ lnet_dyn_add_ni(lnet_pid_t requested_pid, char *nets,
 	struct lnet_ni		*ni;
 	struct list_head	net_head;
 	int			rc;
+	lnet_remotenet_t	*rnet;
 
 	INIT_LIST_HEAD(&net_head);
 
@@ -2007,12 +2008,25 @@ 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 != NULL) {
+		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 != 0)
 		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,