RDS: IB: use address change event for failover/failback

The RDS active bonding code had few fundamental bugs which
have been addressed so the workaround(s) added can be removed.
These workaround are creating problems and races in connection
management code leading to occasional connections stalls.
Removal of these makes the code behavior predictable and clean.

Few notables fixes to mention here:
 - Taking care of all layers of events for ports before
   marking them up/down.
 - ARP cache related fixes.
 - Local loopback connection hang fix

Patch almost make RDS active bonding failover/failback path
as intended from the beginning.
i.e On failover/failback, the address change events needs to
be sent which then triggers all the necessary events to
re-establish the connection(s).

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 b0408e14fbf894e60bc0779b47760c08a3f281e6..467471b247a515287a0480e92f2ebc24313da540 100644 (file)
--- a/net/rds/ib.c
+++ b/net/rds/ib.c
@@ -55,7 +55,6 @@ unsigned int rds_ib_fmr_8k_pool_size = RDS_FMR_8K_POOL_SIZE;
 unsigned int rds_ib_retry_count = RDS_IB_DEFAULT_RETRY_COUNT;
 unsigned int rds_ib_active_bonding_enabled = 0;
 unsigned int rds_ib_active_bonding_fallback = 1;
-unsigned int rds_ib_active_bonding_reconnect_delay = 1;
 unsigned int rds_ib_active_bonding_trigger_delay_max_msecs; /* = 0; */
 unsigned int rds_ib_active_bonding_trigger_delay_min_msecs; /* = 0; */
 unsigned int rds_ib_rnr_retry_count = RDS_IB_DEFAULT_RNR_RETRY_COUNT;
@@ -78,8 +77,6 @@ MODULE_PARM_DESC(rds_ib_active_bonding_fallback, " Active Bonding failback Enabl
 module_param(rds_ib_active_bonding_failover_groups, charp, 0444);
 MODULE_PARM_DESC(rds_ib_active_bonding_failover_groups,
        "<ifname>[,<ifname>]*[;<ifname>[,<ifname>]*]*");
-module_param(rds_ib_active_bonding_reconnect_delay, int, 0444);
-MODULE_PARM_DESC(rds_ib_active_bonding_reconnect_delay, " Active Bonding reconnect delay");
 module_param(rds_ib_active_bonding_trigger_delay_max_msecs, int, 0444);
 MODULE_PARM_DESC(rds_ib_active_bonding_trigger_delay_max_msecs,
                " Active Bonding Max delay before active bonding is triggered(msecs)");
@@ -584,21 +581,6 @@ static int rds_ib_addr_exist(struct net_device *ndev,
        return found;
 }
 
-static void rds_ib_conn_drop(struct work_struct *_work)
-{
-       struct rds_ib_conn_drop_work    *work =
-               container_of(_work, struct rds_ib_conn_drop_work, work.work);
-       struct rds_connection   *conn = work->conn;
-
-       rds_rtd(RDS_RTD_CM_EXT,
-               "conn: %p, calling rds_conn_drop\n", conn);
-
-       conn->c_drop_source = DR_IB_ACTIVE_BOND_FAILOVER;
-       rds_conn_drop(conn);
-
-       kfree(work);
-}
-
 static void rds_ib_notify_addr_change(struct work_struct *_work)
 {
        struct rds_ib_addr_change_work  *work =
@@ -636,7 +618,6 @@ static int rds_ib_move_ip(char                      *from_dev,
        int                     ret = 0;
        u8                      active_port;
        struct in_device        *in_dev;
-       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;
@@ -762,39 +743,6 @@ static int rds_ib_move_ip(char                     *from_dev,
                if (!rds_ibdev)
                        goto out;
 
-               spin_lock_bh(&rds_ibdev->spinlock);
-               list_for_each_entry(ic, &rds_ibdev->conn_list, ib_node) {
-                       if (ic->conn->c_laddr == addr) {
-                               /*
-                                * For failover from HW PORT event, do
-                                * delayed connection drop, else call
-                                * inline
-                                */
-                               if (event_type == RDS_IB_PORT_EVENT_IB &&
-                                       failover) {
-                                       work = kzalloc(sizeof *work, GFP_ATOMIC);
-                                       if (!work) {
-                                               printk(KERN_ERR
-                                                       "RDS/IP: failed to allocate connection drop work\n");
-                                                       spin_unlock_bh(&rds_ibdev->spinlock);
-                                                       goto out;
-                                       }
-
-                                       work->conn = ic->conn;
-                                       INIT_DELAYED_WORK(&work->work, rds_ib_conn_drop);
-                                       queue_delayed_work(rds_aux_wq, &work->work,
-                                               msecs_to_jiffies(1000 * rds_ib_active_bonding_reconnect_delay));
-                               } else {
-                                       rds_rtd(RDS_RTD_CM_EXT,
-                                               "conn: %p, tos %d, calling rds_conn_drop\n",
-                                               ic->conn, ic->conn->c_tos);
-                                       ic->conn->c_drop_source = DR_IB_ACTIVE_BOND_FAILBACK;
-                                       rds_conn_drop(ic->conn);
-                               }
-                       }
-               }
-               spin_unlock_bh(&rds_ibdev->spinlock);
-
                work_addrchange = kzalloc(sizeof *work, GFP_ATOMIC);
                if (!work_addrchange) {
                        printk(KERN_WARNING "RDS/IP: failed to allocate work\n");