RDS: IB: drop workaround for loopback connection hangs

There is no need to modify the ARP cache directly under the
assumption that it helps to speed up the failover/failback for
loopback connections. The ARP cache is properly updated by core
IPv4 code and one of the issue with RDS active bonding code
with arp has been addressed as part of
'commit 42a7becc725f ("RDS: IB: Make use of ARPOP_REQUEST instead
of ARPOP_REPLY in bonding code")'. Remove the workaround added as
part of bug 16979994 with patch "RDS: Local address resolution may
be delayed after IP has moved"

Orabug: 22347191

Tested-by: Michael Nowak <michael.nowak@oracle.com>
Tested-by: Rafael Alejandro Peralez <rafael.peralez@oracle.com>
Tested-by: Liwen Huang <liwen.huang@oracle.com>
Tested-by: Hong Liu <hong.x.liu@oracle.com>
Reviewed-by: Mukesh Kacker <mukesh.kacker@oracle.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@oracle.com>

diff --git a/net/rds/ib.c b/net/rds/ib.c
index e2234280b25e7e3db44ac2613b178aa2146c8e56..b0408e14fbf894e60bc0779b47760c08a3f281e6 100644 (file)
--- a/net/rds/ib.c
+++ b/net/rds/ib.c
@@ -584,26 +584,6 @@ static int rds_ib_addr_exist(struct net_device *ndev,
        return found;
 }
 
-static void rds_ib_update_arp_cache(struct net_device      *out_dev,
-                                       unsigned char      *dev_addr,
-                                       __be32             ip_addr)
-{
-       int ret = 0;
-       struct neighbour *neigh;
-
-       neigh = __neigh_lookup_errno(&arp_tbl, &ip_addr, out_dev);
-       if (!IS_ERR(neigh)) {
-               ret = neigh_update(neigh, dev_addr, NUD_STALE,
-                                       NEIGH_UPDATE_F_OVERRIDE |
-                                       NEIGH_UPDATE_F_ADMIN);
-               if (ret)
-                       printk(KERN_ERR "RDS/IB: neigh_update failed (%d) "
-                               "for out_dev %s IP %u.%u.%u.%u\n",
-                               ret, out_dev->name, NIPQUAD(ip_addr));
-               neigh_release(neigh);
-       }
-}
-
 static void rds_ib_conn_drop(struct work_struct *_work)
 {
        struct rds_ib_conn_drop_work    *work =
@@ -654,9 +634,9 @@ static int rds_ib_move_ip(char                      *from_dev,
        char                    to_dev2[2*IFNAMSIZ + 1];
        char                    *tmp_str;
        int                     ret = 0;
-       u8                      active_port, i, j, port = 0;
+       u8                      active_port;
        struct in_device        *in_dev;
-       struct rds_ib_connection *ic, *ic2;
+       struct rds_ib_connection *ic;
        struct rds_ib_device *rds_ibdev;
        struct rds_ib_conn_drop_work *work;
        struct rds_ib_addr_change_work *work_addrchange;
@@ -785,62 +765,6 @@ static int rds_ib_move_ip(char                     *from_dev,
                spin_lock_bh(&rds_ibdev->spinlock);
                list_for_each_entry(ic, &rds_ibdev->conn_list, ib_node) {
                        if (ic->conn->c_laddr == addr) {
-                               /* if local connection, update the ARP cache */
-                               if (ic->conn->c_loopback) {
-                                       for (i = 1; i <= ip_port_cnt; i++) {
-                                               if (ip_config[i].ip_addr ==
-                                                       ic->conn->c_faddr) {
-                                                       port = i;
-                                                       break;
-                                               }
-
-                                               for (j = 0; j < ip_config[i].alias_cnt; j++) {
-                                                       if (ip_config[i].aliases[j].ip_addr == ic->conn->c_faddr) {
-                                                               port = i;
-                                                               break;
-                                                       }
-                                               }
-                                       }
-
-                                       BUG_ON(!port);
-
-                                       rds_ib_update_arp_cache(
-                                               ip_config[from_port].dev,
-                                               ip_config[port].dev->dev_addr,
-                                               ic->conn->c_faddr);
-
-                                       rds_ib_update_arp_cache(
-                                               ip_config[to_port].dev,
-                                               ip_config[port].dev->dev_addr,
-                                               ic->conn->c_faddr);
-
-                                       rds_ib_update_arp_cache(
-                                               ip_config[from_port].dev,
-                                               ip_config[to_port].dev->dev_addr,
-                                               ic->conn->c_laddr);
-
-                                       rds_ib_update_arp_cache(
-                                               ip_config[to_port].dev,
-                                               ip_config[to_port].dev->dev_addr,
-                                               ic->conn->c_laddr);
-
-                                       list_for_each_entry(ic2,
-                                               &rds_ibdev->conn_list,
-                                                       ib_node) {
-                                               if (ic2->conn->c_laddr ==
-                                                       ic->conn->c_faddr &&
-                                                       ic2->conn->c_faddr ==
-                                                       ic->conn->c_laddr) {
-                                                       rds_rtd(RDS_RTD_CM_EXT_P,
-                                                               "conn:%p, tos %d, calling rds_conn_drop\n",
-                                                               ic2->conn,
-                                                               ic2->conn->c_tos);
-                                                       ic2->conn->c_drop_source = DR_IB_LOOPBACK_CONN_DROP;
-                                                       rds_conn_drop(ic2->conn);
-                                               }
-                                       }
-                               }
-
                                /*
                                 * For failover from HW PORT event, do
                                 * delayed connection drop, else call