From: Håkon Bugge <haakon.bugge@oracle.com>
Date: Thu, 7 Mar 2019 11:36:44 +0000 (+0100)
Subject: rds: ib: Flush ARP cache when needed
X-Git-Tag: v4.1.12-124.31.3~112
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=98954c41cdd34113e91ae20b3d916d75100236c6;p=users%2Fjedix%2Flinux-maple.git

rds: ib: Flush ARP cache when needed

During Active/Active fail-over and fail-back, the ARP cache may
contain stale entries. Hence flush the foreign address from the ARP
cache when the following events are received:

   * address change
   * address error
   * unreachable
   * disconnect

Orabug: 29391909

Suggested-by: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Signed-off-by: Håkon Bugge <haakon.bugge@oracle.com>
Tested-by: Rosa Lopez <rosa.lopez@oracle.com>
Reviewed-by: Dag Moxnes <dag.moxnes@oracle.com>
Signed-off-by: Brian Maly <brian.maly@oracle.com>
---

diff --git a/net/rds/rdma_transport.c b/net/rds/rdma_transport.c
index 3a02ba9f099b..259e9ece958d 100644
--- a/net/rds/rdma_transport.c
+++ b/net/rds/rdma_transport.c
@@ -126,6 +126,12 @@ int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
 			rds_rtd(RDS_RTD_CM, "Bailing, conn %p being shut down, ret: %d\n",
 				conn, ret);
 			conn->c_reconnect_racing = 1;
+			if (event->event == RDMA_CM_EVENT_ADDR_CHANGE ||
+			    event->event == RDMA_CM_EVENT_DISCONNECTED)
+				/* These events might indicate the IP being moved,
+				 * hence flush the address
+				 */
+				rds_ib_flush_arp_entry(&conn->c_faddr);
 			goto out;
 		}
 	}
@@ -225,6 +231,8 @@ int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
 
 	case RDMA_CM_EVENT_ADDR_ERROR:
 		if (conn) {
+			/* IP might have been moved so flush the ARP entry and retry */
+			rds_ib_flush_arp_entry(&conn->c_faddr);
 			rds_rtd_ptr(RDS_RTD_ERR,
 				    "ADDR_ERROR: conn %p, calling rds_conn_drop <%pI6c,%pI6c,%d>\n",
 				    conn, &conn->c_laddr,
@@ -238,6 +246,8 @@ int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
 	case RDMA_CM_EVENT_UNREACHABLE:
 	case RDMA_CM_EVENT_DEVICE_REMOVAL:
 		if (conn) {
+			/* IP might have been moved so flush the ARP entry and retry */
+			rds_ib_flush_arp_entry(&conn->c_faddr);
 			rds_rtd_ptr(RDS_RTD_ERR,
 				    "CONN/UNREACHABLE/RMVAL ERR: conn %p, calling rds_conn_drop <%pI6c,%pI6c,%d>\n",
 				    conn, &conn->c_laddr,
@@ -294,6 +304,8 @@ int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
 		break;
 
 	case RDMA_CM_EVENT_ADDR_CHANGE:
+		/* IP might have been moved so flush the ARP entry and retry */
+		rds_ib_flush_arp_entry(&conn->c_faddr);
 		rds_rtd_ptr(RDS_RTD_CM_EXT,
 			    "ADDR_CHANGE event <%pI6c,%pI6c>\n",
 			    &conn->c_laddr,
@@ -311,6 +323,8 @@ int rds_rdma_cm_event_handler_cmn(struct rdma_cm_id *cm_id,
 		break;
 
 	case RDMA_CM_EVENT_DISCONNECTED:
+		/* IP might have been moved so flush the ARP entry and retry */
+		rds_ib_flush_arp_entry(&conn->c_faddr);
 		rds_rtd_ptr(RDS_RTD_CM,
 			    "DISCONNECT event - dropping conn %p <%pI6c,%pI6c,%d>\n",
 			    conn, &conn->c_laddr, &conn->c_faddr, conn->c_tos);