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LU-7362 lnet: Remove LASSERTS from router checker
[fs/lustre-release.git] / lnet / lnet / router.c
index e041a37..072adcc 100644 (file)
@@ -1,10 +1,9 @@
 /*
  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  *
- * Copyright (c) 2011, 2013, Intel Corporation.
+ * Copyright (c) 2011, 2015, Intel Corporation.
  *
- *   This file is part of Portals
- *   http://sourceforge.net/projects/sandiaportals/
+ *   This file is part of Lustre, https://wiki.hpdd.intel.com/
  *
  *   Portals is free software; you can redistribute it and/or
  *   modify it under the terms of version 2 of the GNU General Public
 #define DEBUG_SUBSYSTEM S_LNET
 #include <lnet/lib-lnet.h>
 
-#if defined(__KERNEL__) && defined(LNET_ROUTER)
-
 #define LNET_NRB_TINY_MIN      512     /* min value for each CPT */
 #define LNET_NRB_TINY          (LNET_NRB_TINY_MIN * 4)
 #define LNET_NRB_SMALL_MIN     4096    /* min value for each CPT */
 #define LNET_NRB_SMALL         (LNET_NRB_SMALL_MIN * 4)
+#define LNET_NRB_SMALL_PAGES   1
 #define LNET_NRB_LARGE_MIN     256     /* min value for each CPT */
 #define LNET_NRB_LARGE         (LNET_NRB_LARGE_MIN * 4)
+#define LNET_NRB_LARGE_PAGES   ((LNET_MTU + PAGE_CACHE_SIZE - 1) >> \
+                                 PAGE_CACHE_SHIFT)
 
 static char *forwarding = "";
 CFS_MODULE_PARM(forwarding, "s", charp, 0444,
@@ -70,21 +70,12 @@ lnet_peer_buffer_credits(lnet_ni_t *ni)
 
 /* forward ref's */
 static int lnet_router_checker(void *);
-#else
-
-int
-lnet_peer_buffer_credits(lnet_ni_t *ni)
-{
-        return 0;
-}
-
-#endif
 
 static int check_routers_before_use = 0;
 CFS_MODULE_PARM(check_routers_before_use, "i", int, 0444,
                "Assume routers are down and ping them before use");
 
-static int avoid_asym_router_failure = 1;
+int avoid_asym_router_failure = 1;
 CFS_MODULE_PARM(avoid_asym_router_failure, "i", int, 0644,
                "Avoid asymmetrical router failures (0 to disable)");
 
@@ -135,7 +126,7 @@ lnet_notify_locked(lnet_peer_t *lp, int notifylnd, int alive, cfs_time_t when)
        CDEBUG(D_NET, "set %s %d\n", libcfs_nid2str(lp->lp_nid), alive);
 }
 
-void
+static void
 lnet_ni_notify_locked(lnet_ni_t *ni, lnet_peer_t *lp)
 {
         int        alive;
@@ -145,7 +136,7 @@ lnet_ni_notify_locked(lnet_ni_t *ni, lnet_peer_t *lp)
          * NB individual events can be missed; the only guarantee is that you
          * always get the most recent news */
 
-       if (lp->lp_notifying)
+       if (lp->lp_notifying || ni == NULL)
                 return;
 
         lp->lp_notifying = 1;
@@ -245,10 +236,11 @@ lnet_find_net_locked (__u32 net)
 
 static void lnet_shuffle_seed(void)
 {
-        static int seeded = 0;
-        int lnd_type, seed[2];
-        struct timeval tv;
-        lnet_ni_t *ni;
+       static int seeded;
+       __u32 lnd_type;
+       __u32 seed[2];
+       struct timeval tv;
+       lnet_ni_t *ni;
        struct list_head *tmp;
 
         if (seeded)
@@ -273,8 +265,8 @@ static void lnet_shuffle_seed(void)
 }
 
 /* NB expects LNET_LOCK held */
-void
-lnet_add_route_to_rnet (lnet_remotenet_t *rnet, lnet_route_t *route)
+static void
+lnet_add_route_to_rnet(lnet_remotenet_t *rnet, lnet_route_t *route)
 {
        unsigned int      len = 0;
        unsigned int      offset = 0;
@@ -304,44 +296,44 @@ int
 lnet_add_route(__u32 net, unsigned int hops, lnet_nid_t gateway,
               unsigned int priority)
 {
-       struct list_head *e;
-       lnet_remotenet_t *rnet;
-       lnet_remotenet_t *rnet2;
-       lnet_route_t     *route;
-       lnet_ni_t        *ni;
-       int               add_route;
-       int               rc;
+       struct list_head        *e;
+       lnet_remotenet_t        *rnet;
+       lnet_remotenet_t        *rnet2;
+       lnet_route_t            *route;
+       lnet_ni_t               *ni;
+       int                     add_route;
+       int                     rc;
 
        CDEBUG(D_NET, "Add route: net %s hops %u priority %u gw %s\n",
               libcfs_net2str(net), hops, priority, libcfs_nid2str(gateway));
 
-        if (gateway == LNET_NID_ANY ||
-            LNET_NETTYP(LNET_NIDNET(gateway)) == LOLND ||
-            net == LNET_NIDNET(LNET_NID_ANY) ||
-            LNET_NETTYP(net) == LOLND ||
-            LNET_NIDNET(gateway) == net ||
-            hops < 1 || hops > 255)
-                return (-EINVAL);
-
-        if (lnet_islocalnet(net))               /* it's a local network */
-                return 0;                       /* ignore the route entry */
-
-        /* Assume net, route, all new */
-        LIBCFS_ALLOC(route, sizeof(*route));
-        LIBCFS_ALLOC(rnet, sizeof(*rnet));
-        if (route == NULL || rnet == NULL) {
-                CERROR("Out of memory creating route %s %d %s\n",
-                       libcfs_net2str(net), hops, libcfs_nid2str(gateway));
-                if (route != NULL)
-                        LIBCFS_FREE(route, sizeof(*route));
-                if (rnet != NULL)
-                        LIBCFS_FREE(rnet, sizeof(*rnet));
-                return -ENOMEM;
-        }
+       if (gateway == LNET_NID_ANY ||
+           LNET_NETTYP(LNET_NIDNET(gateway)) == LOLND ||
+           net == LNET_NIDNET(LNET_NID_ANY) ||
+           LNET_NETTYP(net) == LOLND ||
+           LNET_NIDNET(gateway) == net ||
+           hops < 1 || hops > 255)
+               return -EINVAL;
+
+       if (lnet_islocalnet(net))       /* it's a local network */
+               return -EEXIST;
+
+       /* Assume net, route, all new */
+       LIBCFS_ALLOC(route, sizeof(*route));
+       LIBCFS_ALLOC(rnet, sizeof(*rnet));
+       if (route == NULL || rnet == NULL) {
+               CERROR("Out of memory creating route %s %d %s\n",
+                      libcfs_net2str(net), hops, libcfs_nid2str(gateway));
+               if (route != NULL)
+                       LIBCFS_FREE(route, sizeof(*route));
+               if (rnet != NULL)
+                       LIBCFS_FREE(rnet, sizeof(*rnet));
+               return -ENOMEM;
+       }
 
        INIT_LIST_HEAD(&rnet->lrn_routes);
-        rnet->lrn_net = net;
-        route->lr_hops = hops;
+       rnet->lrn_net = net;
+       route->lr_hops = hops;
        route->lr_net = net;
        route->lr_priority = priority;
 
@@ -354,17 +346,15 @@ lnet_add_route(__u32 net, unsigned int hops, lnet_nid_t gateway,
                LIBCFS_FREE(route, sizeof(*route));
                LIBCFS_FREE(rnet, sizeof(*rnet));
 
-               if (rc == -EHOSTUNREACH) { /* gateway is not on a local net */
-                       return 0;       /* ignore the route entry */
-               } else {
-                       CERROR("Error %d creating route %s %d %s\n", rc,
-                              libcfs_net2str(net), hops,
-                              libcfs_nid2str(gateway));
-               }
-                return rc;
-        }
+               if (rc == -EHOSTUNREACH) /* gateway is not on a local net. */
+                       return rc;       /* ignore the route entry */
+               CERROR("Error %d creating route %s %d %s\n", rc,
+                       libcfs_net2str(net), hops,
+                       libcfs_nid2str(gateway));
+               return rc;
+       }
 
-        LASSERT (!the_lnet.ln_shutdown);
+       LASSERT(!the_lnet.ln_shutdown);
 
        rnet2 = lnet_find_net_locked(net);
        if (rnet2 == NULL) {
@@ -378,16 +368,16 @@ lnet_add_route(__u32 net, unsigned int hops, lnet_nid_t gateway,
        list_for_each(e, &rnet2->lrn_routes) {
                lnet_route_t *route2 = list_entry(e, lnet_route_t, lr_list);
 
-                if (route2->lr_gateway == route->lr_gateway) {
-                        add_route = 0;
-                        break;
-                }
+               if (route2->lr_gateway == route->lr_gateway) {
+                       add_route = 0;
+                       break;
+               }
 
-                /* our lookups must be true */
-                LASSERT (route2->lr_gateway->lp_nid != gateway);
-        }
+               /* our lookups must be true */
+               LASSERT(route2->lr_gateway->lp_nid != gateway);
+       }
 
-        if (add_route) {
+       if (add_route) {
                lnet_peer_addref_locked(route->lr_gateway); /* +1 for notify */
                lnet_add_route_to_rnet(rnet2, route);
 
@@ -405,13 +395,20 @@ lnet_add_route(__u32 net, unsigned int hops, lnet_nid_t gateway,
        lnet_peer_decref_locked(route->lr_gateway);
        lnet_net_unlock(LNET_LOCK_EX);
 
-       if (!add_route)
+       rc = 0;
+
+       if (!add_route) {
+               rc = -EEXIST;
                LIBCFS_FREE(route, sizeof(*route));
+       }
 
        if (rnet != rnet2)
                LIBCFS_FREE(rnet, sizeof(*rnet));
 
-       return 0;
+       /* indicate to startup the router checker if configured */
+       wake_up(&the_lnet.ln_rc_waitq);
+
+       return rc;
 }
 
 int
@@ -552,6 +549,42 @@ lnet_destroy_routes (void)
         lnet_del_route(LNET_NIDNET(LNET_NID_ANY), LNET_NID_ANY);
 }
 
+int lnet_get_rtr_pool_cfg(int idx, struct lnet_ioctl_pool_cfg *pool_cfg)
+{
+       int i, rc = -ENOENT, lidx, j;
+
+       if (the_lnet.ln_rtrpools == NULL)
+               return rc;
+
+       for (i = 0; i < LNET_NRBPOOLS; i++) {
+               lnet_rtrbufpool_t *rbp;
+
+               lnet_net_lock(LNET_LOCK_EX);
+               lidx = idx;
+               cfs_percpt_for_each(rbp, j, the_lnet.ln_rtrpools) {
+                       if (lidx-- == 0) {
+                               rc = 0;
+                               pool_cfg->pl_pools[i].pl_npages =
+                                       rbp[i].rbp_npages;
+                               pool_cfg->pl_pools[i].pl_nbuffers =
+                                       rbp[i].rbp_nbuffers;
+                               pool_cfg->pl_pools[i].pl_credits =
+                                       rbp[i].rbp_credits;
+                               pool_cfg->pl_pools[i].pl_mincredits =
+                                       rbp[i].rbp_mincredits;
+                               break;
+                       }
+               }
+               lnet_net_unlock(LNET_LOCK_EX);
+       }
+
+       lnet_net_lock(LNET_LOCK_EX);
+       pool_cfg->pl_routing = the_lnet.ln_routing;
+       lnet_net_unlock(LNET_LOCK_EX);
+
+       return rc;
+}
+
 int
 lnet_get_route(int idx, __u32 *net, __u32 *hops,
               lnet_nid_t *gateway, __u32 *alive, __u32 *priority)
@@ -580,7 +613,7 @@ lnet_get_route(int idx, __u32 *net, __u32 *hops,
                                        *hops     = route->lr_hops;
                                        *priority = route->lr_priority;
                                        *gateway  = route->lr_gateway->lp_nid;
-                                       *alive    = route->lr_gateway->lp_alive;
+                                       *alive    = lnet_is_route_alive(route);
                                        lnet_net_unlock(cpt);
                                        return 0;
                                }
@@ -600,14 +633,14 @@ lnet_swap_pinginfo(lnet_ping_info_t *info)
 
        __swab32s(&info->pi_magic);
        __swab32s(&info->pi_features);
-        __swab32s(&info->pi_pid);
-        __swab32s(&info->pi_nnis);
-        for (i = 0; i < info->pi_nnis && i < LNET_MAX_RTR_NIS; i++) {
-                stat = &info->pi_ni[i];
-                __swab64s(&stat->ns_nid);
-                __swab32s(&stat->ns_status);
-        }
-        return;
+       __swab32s(&info->pi_pid);
+       __swab32s(&info->pi_nnis);
+       for (i = 0; i < info->pi_nnis && i < LNET_MAX_RTR_NIS; i++) {
+               stat = &info->pi_ni[i];
+               __swab64s(&stat->ns_nid);
+               __swab32s(&stat->ns_status);
+       }
+       return;
 }
 
 /**
@@ -619,7 +652,7 @@ lnet_parse_rc_info(lnet_rc_data_t *rcd)
 {
        lnet_ping_info_t        *info = rcd->rcd_pinginfo;
        struct lnet_peer        *gw   = rcd->rcd_gateway;
-       lnet_route_t            *rtr;
+       lnet_route_t            *rte;
 
        if (!gw->lp_alive)
                return;
@@ -645,11 +678,16 @@ lnet_parse_rc_info(lnet_rc_data_t *rcd)
        if ((gw->lp_ping_feats & LNET_PING_FEAT_NI_STATUS) == 0)
                return; /* can't carry NI status info */
 
-       list_for_each_entry(rtr, &gw->lp_routes, lr_gwlist) {
+       list_for_each_entry(rte, &gw->lp_routes, lr_gwlist) {
                int     down = 0;
                int     up = 0;
                int     i;
 
+               if ((gw->lp_ping_feats & LNET_PING_FEAT_RTE_DISABLED) != 0) {
+                       rte->lr_downis = 1;
+                       continue;
+               }
+
                for (i = 0; i < info->pi_nnis && i < LNET_MAX_RTR_NIS; i++) {
                        lnet_ni_status_t *stat = &info->pi_ni[i];
                        lnet_nid_t       nid = stat->ns_nid;
@@ -670,7 +708,7 @@ lnet_parse_rc_info(lnet_rc_data_t *rcd)
                        }
 
                        if (stat->ns_status == LNET_NI_STATUS_UP) {
-                               if (LNET_NIDNET(nid) == rtr->lr_net) {
+                               if (LNET_NIDNET(nid) == rte->lr_net) {
                                        up = 1;
                                        break;
                                }
@@ -684,10 +722,15 @@ lnet_parse_rc_info(lnet_rc_data_t *rcd)
                }
 
                if (up) { /* ignore downed NIs if NI for dest network is up */
-                       rtr->lr_downis = 0;
+                       rte->lr_downis = 0;
                        continue;
                }
-               rtr->lr_downis = down;
+               /* if @down is zero and this route is single-hop, it means
+                * we can't find NI for target network */
+               if (down == 0 && rte->lr_hops == 1)
+                       down = 1;
+
+               rte->lr_downis = down;
        }
 }
 
@@ -744,7 +787,7 @@ lnet_router_checker_event(lnet_event_t *event)
        lnet_net_unlock(lp->lp_cpt);
 }
 
-void
+static void
 lnet_wait_known_routerstate(void)
 {
        lnet_peer_t      *rtr;
@@ -771,14 +814,27 @@ lnet_wait_known_routerstate(void)
                if (all_known)
                         return;
 
-#ifndef __KERNEL__
-                lnet_router_checker();
-#endif
-                cfs_pause(cfs_time_seconds(1));
-        }
+               set_current_state(TASK_UNINTERRUPTIBLE);
+               schedule_timeout(cfs_time_seconds(1));
+       }
 }
 
 void
+lnet_router_ni_update_locked(lnet_peer_t *gw, __u32 net)
+{
+       lnet_route_t *rte;
+
+       if ((gw->lp_ping_feats & LNET_PING_FEAT_NI_STATUS) != 0) {
+               list_for_each_entry(rte, &gw->lp_routes, lr_gwlist) {
+                       if (rte->lr_net == net) {
+                               rte->lr_downis = 0;
+                               break;
+                       }
+               }
+       }
+}
+
+static void
 lnet_update_ni_status_locked(void)
 {
        lnet_ni_t       *ni;
@@ -818,7 +874,7 @@ lnet_update_ni_status_locked(void)
        }
 }
 
-void
+static void
 lnet_destroy_rc_data(lnet_rc_data_t *rcd)
 {
        LASSERT(list_empty(&rcd->rcd_list));
@@ -839,7 +895,7 @@ lnet_destroy_rc_data(lnet_rc_data_t *rcd)
        LIBCFS_FREE(rcd, sizeof(*rcd));
 }
 
-lnet_rc_data_t *
+static lnet_rc_data_t *
 lnet_create_rc_data_locked(lnet_peer_t *gateway)
 {
        lnet_rc_data_t          *rcd = NULL;
@@ -967,7 +1023,7 @@ lnet_ping_router_locked (lnet_peer_t *rtr)
                 lnet_handle_md_t  mdh;
 
                 id.nid = rtr->lp_nid;
-                id.pid = LUSTRE_SRV_LNET_PID;
+               id.pid = LNET_PID_LUSTRE;
                 CDEBUG(D_NET, "Check: %s\n", libcfs_id2str(id));
 
                 rtr->lp_ping_notsent   = 1;
@@ -998,67 +1054,10 @@ int
 lnet_router_checker_start(void)
 {
        int                     rc;
-       int                     eqsz;
-#ifdef __KERNEL__
+       int                     eqsz = 0;
        struct task_struct     *task;
-#else /* __KERNEL__ */
-       lnet_peer_t            *rtr;
-       __u64                   version;
-       int                     nrtr = 0;
-       int                     router_checker_max_eqsize = 10240;
-
-        LASSERT (check_routers_before_use);
-        LASSERT (dead_router_check_interval > 0);
-
-       lnet_net_lock(0);
-
-        /* As an approximation, allow each router the same number of
-         * outstanding events as it is allowed outstanding sends */
-        eqsz = 0;
-        version = the_lnet.ln_routers_version;
-       list_for_each_entry(rtr, &the_lnet.ln_routers, lp_rtr_list) {
-                lnet_ni_t         *ni = rtr->lp_ni;
-                lnet_process_id_t  id;
-
-                nrtr++;
-                eqsz += ni->ni_peertxcredits;
 
-                /* one async ping reply per router */
-                id.nid = rtr->lp_nid;
-                id.pid = LUSTRE_SRV_LNET_PID;
-
-               lnet_net_unlock(0);
-
-                rc = LNetSetAsync(id, 1);
-                if (rc != 0) {
-                        CWARN("LNetSetAsync %s failed: %d\n",
-                              libcfs_id2str(id), rc);
-                        return rc;
-                }
-
-               lnet_net_lock(0);
-               /* NB router list doesn't change in userspace */
-               LASSERT(version == the_lnet.ln_routers_version);
-       }
-
-       lnet_net_unlock(0);
-
-        if (nrtr == 0) {
-                CDEBUG(D_NET,
-                       "No router found, not starting router checker\n");
-                return 0;
-        }
-
-        /* at least allow a SENT and a REPLY per router */
-        if (router_checker_max_eqsize < 2 * nrtr)
-                router_checker_max_eqsize = 2 * nrtr;
-
-        LASSERT (eqsz > 0);
-        if (eqsz > router_checker_max_eqsize)
-                eqsz = router_checker_max_eqsize;
-#endif
-
-        LASSERT (the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
+       LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
 
         if (check_routers_before_use &&
             dead_router_check_interval <= 0) {
@@ -1068,29 +1067,15 @@ lnet_router_checker_start(void)
                 return -EINVAL;
         }
 
-        if (!the_lnet.ln_routing &&
-            live_router_check_interval <= 0 &&
-            dead_router_check_interval <= 0)
-                return 0;
-
-#ifdef __KERNEL__
        sema_init(&the_lnet.ln_rc_signal, 0);
-        /* EQ size doesn't matter; the callback is guaranteed to get every
-         * event */
-       eqsz = 0;
-        rc = LNetEQAlloc(eqsz, lnet_router_checker_event,
-                         &the_lnet.ln_rc_eqh);
-#else
-        rc = LNetEQAlloc(eqsz, LNET_EQ_HANDLER_NONE,
-                         &the_lnet.ln_rc_eqh);
-#endif
-        if (rc != 0) {
-                CERROR("Can't allocate EQ(%d): %d\n", eqsz, rc);
-                return -ENOMEM;
-        }
 
-        the_lnet.ln_rc_state = LNET_RC_STATE_RUNNING;
-#ifdef __KERNEL__
+       rc = LNetEQAlloc(0, lnet_router_checker_event, &the_lnet.ln_rc_eqh);
+       if (rc != 0) {
+               CERROR("Can't allocate EQ(%d): %d\n", eqsz, rc);
+               return -ENOMEM;
+       }
+
+       the_lnet.ln_rc_state = LNET_RC_STATE_RUNNING;
        task = kthread_run(lnet_router_checker, NULL, "router_checker");
        if (IS_ERR(task)) {
                rc = PTR_ERR(task);
@@ -1102,7 +1087,6 @@ lnet_router_checker_start(void)
                the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
                return -ENOMEM;
        }
-#endif
 
         if (check_routers_before_use) {
                 /* Note that a helpful side-effect of pinging all known routers
@@ -1117,20 +1101,18 @@ lnet_router_checker_start(void)
 void
 lnet_router_checker_stop (void)
 {
-        int rc;
+       int rc;
 
-        if (the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN)
-                return;
+       if (the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN)
+               return;
 
-        LASSERT (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
+       LASSERT (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
        the_lnet.ln_rc_state = LNET_RC_STATE_STOPPING;
+       /* wakeup the RC thread if it's sleeping */
+       wake_up(&the_lnet.ln_rc_waitq);
 
-#ifdef __KERNEL__
        /* block until event callback signals exit */
        down(&the_lnet.ln_rc_signal);
-#else
-       lnet_router_checker();
-#endif
        LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
 
         rc = LNetEQFree(the_lnet.ln_rc_eqh);
@@ -1210,7 +1192,8 @@ lnet_prune_rc_data(int wait_unlink)
                i++;
                CDEBUG(((i & (-i)) == i) ? D_WARNING : D_NET,
                       "Waiting for rc buffers to unlink\n");
-               cfs_pause(cfs_time_seconds(1) / 4);
+               set_current_state(TASK_UNINTERRUPTIBLE);
+               schedule_timeout(cfs_time_seconds(1) / 4);
 
                lnet_net_lock(LNET_LOCK_EX);
        }
@@ -1218,20 +1201,40 @@ lnet_prune_rc_data(int wait_unlink)
        lnet_net_unlock(LNET_LOCK_EX);
 }
 
+/*
+ * This function is called to check if the RC should block indefinitely.
+ * It's called from lnet_router_checker() as well as being passed to
+ * wait_event_interruptible() to avoid the lost wake_up problem.
+ *
+ * When it's called from wait_event_interruptible() it is necessary to
+ * also not sleep if the rc state is not running to avoid a deadlock
+ * when the system is shutting down
+ */
+static inline bool
+lnet_router_checker_active(void)
+{
+       if (the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING)
+               return true;
+
+       /* Router Checker thread needs to run when routing is enabled in
+        * order to call lnet_update_ni_status_locked() */
+       if (the_lnet.ln_routing)
+               return true;
 
-#if defined(__KERNEL__) && defined(LNET_ROUTER)
+       return !list_empty(&the_lnet.ln_routers) &&
+               (live_router_check_interval > 0 ||
+                dead_router_check_interval > 0);
+}
 
 static int
 lnet_router_checker(void *arg)
 {
-        lnet_peer_t       *rtr;
+       lnet_peer_t       *rtr;
        struct list_head  *entry;
 
-        cfs_block_allsigs();
-
-        LASSERT (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
+       cfs_block_allsigs();
 
-        while (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING) {
+       while (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING) {
                __u64   version;
                int     cpt;
                int     cpt2;
@@ -1253,14 +1256,14 @@ rescan:
                                        goto rescan;
                        }
 
-                        lnet_ping_router_locked(rtr);
+                       lnet_ping_router_locked(rtr);
 
-                        /* NB dropped lock */
-                        if (version != the_lnet.ln_routers_version) {
-                                /* the routers list has changed */
-                                goto rescan;
-                        }
-                }
+                       /* NB dropped lock */
+                       if (version != the_lnet.ln_routers_version) {
+                               /* the routers list has changed */
+                               goto rescan;
+                       }
+               }
 
                if (the_lnet.ln_routing)
                        lnet_update_ni_status_locked();
@@ -1269,15 +1272,21 @@ rescan:
 
                lnet_prune_rc_data(0); /* don't wait for UNLINK */
 
-               /* Call cfs_pause() here always adds 1 to load average
+               /* Call schedule_timeout() here always adds 1 to load average
                 * because kernel counts # active tasks as nr_running
                 * + nr_uninterruptible. */
-               schedule_timeout_and_set_state(TASK_INTERRUPTIBLE,
-                                                  cfs_time_seconds(1));
+               /* if there are any routes then wakeup every second.  If
+                * there are no routes then sleep indefinitely until woken
+                * up by a user adding a route */
+               if (!lnet_router_checker_active())
+                       wait_event_interruptible(the_lnet.ln_rc_waitq,
+                                                lnet_router_checker_active());
+               else
+                       wait_event_interruptible_timeout(the_lnet.ln_rc_waitq,
+                                                        false,
+                                                        cfs_time_seconds(1));
        }
 
-       LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_STOPPING);
-
        lnet_prune_rc_data(1); /* wait for UNLINK */
 
        the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
@@ -1297,14 +1306,14 @@ lnet_destroy_rtrbuf(lnet_rtrbuf_t *rb, int npages)
         LIBCFS_FREE(rb, sz);
 }
 
-lnet_rtrbuf_t *
+static lnet_rtrbuf_t *
 lnet_new_rtrbuf(lnet_rtrbufpool_t *rbp, int cpt)
 {
-        int            npages = rbp->rbp_npages;
-        int            sz = offsetof(lnet_rtrbuf_t, rb_kiov[npages]);
-        struct page   *page;
-        lnet_rtrbuf_t *rb;
-        int            i;
+       int            npages = rbp->rbp_npages;
+       int            sz = offsetof(lnet_rtrbuf_t, rb_kiov[npages]);
+       struct page   *page;
+       lnet_rtrbuf_t *rb;
+       int            i;
 
        LIBCFS_CPT_ALLOC(rb, lnet_cpt_table(), cpt, sz);
        if (rb == NULL)
@@ -1331,82 +1340,126 @@ lnet_new_rtrbuf(lnet_rtrbufpool_t *rbp, int cpt)
         return rb;
 }
 
-void
-lnet_rtrpool_free_bufs(lnet_rtrbufpool_t *rbp)
+static void
+lnet_rtrpool_free_bufs(lnet_rtrbufpool_t *rbp, int cpt)
 {
-       int             npages = rbp->rbp_npages;
-       int             nbuffers = 0;
-       lnet_rtrbuf_t   *rb;
+       int              npages = rbp->rbp_npages;
+       lnet_rtrbuf_t    *rb;
+       struct list_head tmp;
 
        if (rbp->rbp_nbuffers == 0) /* not initialized or already freed */
                return;
 
-       LASSERT(list_empty(&rbp->rbp_msgs));
-       LASSERT(rbp->rbp_credits == rbp->rbp_nbuffers);
+       INIT_LIST_HEAD(&tmp);
 
-       while (!list_empty(&rbp->rbp_bufs)) {
-               LASSERT(rbp->rbp_credits > 0);
+       lnet_net_lock(cpt);
+       lnet_drop_routed_msgs_locked(&rbp->rbp_msgs, cpt);
+       list_splice_init(&rbp->rbp_bufs, &tmp);
+       rbp->rbp_req_nbuffers = 0;
+       rbp->rbp_nbuffers = rbp->rbp_credits = 0;
+       rbp->rbp_mincredits = 0;
+       lnet_net_unlock(cpt);
 
-               rb = list_entry(rbp->rbp_bufs.next,
-                               lnet_rtrbuf_t, rb_list);
+       /* Free buffers on the free list. */
+       while (!list_empty(&tmp)) {
+               rb = list_entry(tmp.next, lnet_rtrbuf_t, rb_list);
                list_del(&rb->rb_list);
                lnet_destroy_rtrbuf(rb, npages);
-               nbuffers++;
        }
-
-       LASSERT(rbp->rbp_nbuffers == nbuffers);
-       LASSERT(rbp->rbp_credits == nbuffers);
-
-       rbp->rbp_nbuffers = rbp->rbp_credits = 0;
 }
 
-int
-lnet_rtrpool_alloc_bufs(lnet_rtrbufpool_t *rbp, int nbufs, int cpt)
+static int
+lnet_rtrpool_adjust_bufs(lnet_rtrbufpool_t *rbp, int nbufs, int cpt)
 {
-        lnet_rtrbuf_t *rb;
-        int            i;
+       struct list_head rb_list;
+       lnet_rtrbuf_t   *rb;
+       int             num_rb;
+       int             num_buffers = 0;
+       int             old_req_nbufs;
+       int             npages = rbp->rbp_npages;
 
-        if (rbp->rbp_nbuffers != 0) {
-                LASSERT (rbp->rbp_nbuffers == nbufs);
-                return 0;
-        }
+       lnet_net_lock(cpt);
+       /* If we are called for less buffers than already in the pool, we
+        * just lower the req_nbuffers number and excess buffers will be
+        * thrown away as they are returned to the free list.  Credits
+        * then get adjusted as well.
+        * If we already have enough buffers allocated to serve the
+        * increase requested, then we can treat that the same way as we
+        * do the decrease. */
+       num_rb = nbufs - rbp->rbp_nbuffers;
+       if (nbufs <= rbp->rbp_req_nbuffers || num_rb <= 0) {
+               rbp->rbp_req_nbuffers = nbufs;
+               lnet_net_unlock(cpt);
+               return 0;
+       }
+       /* store the older value of rbp_req_nbuffers and then set it to
+        * the new request to prevent lnet_return_rx_credits_locked() from
+        * freeing buffers that we need to keep around */
+       old_req_nbufs = rbp->rbp_req_nbuffers;
+       rbp->rbp_req_nbuffers = nbufs;
+       lnet_net_unlock(cpt);
 
-        for (i = 0; i < nbufs; i++) {
+       INIT_LIST_HEAD(&rb_list);
+
+       /* allocate the buffers on a local list first.  If all buffers are
+        * allocated successfully then join this list to the rbp buffer
+        * list.  If not then free all allocated buffers. */
+       while (num_rb-- > 0) {
                rb = lnet_new_rtrbuf(rbp, cpt);
+               if (rb == NULL) {
+                       CERROR("Failed to allocate %d route bufs of %d pages\n",
+                              nbufs, npages);
 
-                if (rb == NULL) {
-                        CERROR("Failed to allocate %d router bufs of %d pages\n",
-                               nbufs, rbp->rbp_npages);
-                        return -ENOMEM;
-                }
+                       lnet_net_lock(cpt);
+                       rbp->rbp_req_nbuffers = old_req_nbufs;
+                       lnet_net_unlock(cpt);
 
-               rbp->rbp_nbuffers++;
-               rbp->rbp_credits++;
-               rbp->rbp_mincredits++;
-               list_add(&rb->rb_list, &rbp->rbp_bufs);
+                       goto failed;
+               }
 
-                /* No allocation "under fire" */
-                /* Otherwise we'd need code to schedule blocked msgs etc */
-               LASSERT(!the_lnet.ln_routing);
+               list_add(&rb->rb_list, &rb_list);
+               num_buffers++;
        }
 
-       LASSERT(rbp->rbp_credits == nbufs);
+       lnet_net_lock(cpt);
+
+       list_splice_tail(&rb_list, &rbp->rbp_bufs);
+       rbp->rbp_nbuffers += num_buffers;
+       rbp->rbp_credits += num_buffers;
+       rbp->rbp_mincredits = rbp->rbp_credits;
+       /* We need to schedule blocked msg using the newly
+        * added buffers. */
+       while (!list_empty(&rbp->rbp_bufs) &&
+              !list_empty(&rbp->rbp_msgs))
+               lnet_schedule_blocked_locked(rbp);
+
+       lnet_net_unlock(cpt);
+
        return 0;
+
+failed:
+       while (!list_empty(&rb_list)) {
+               rb = list_entry(rb_list.next, lnet_rtrbuf_t, rb_list);
+               list_del(&rb->rb_list);
+               lnet_destroy_rtrbuf(rb, npages);
+       }
+
+       return -ENOMEM;
 }
 
-void
+static void
 lnet_rtrpool_init(lnet_rtrbufpool_t *rbp, int npages)
 {
        INIT_LIST_HEAD(&rbp->rbp_msgs);
        INIT_LIST_HEAD(&rbp->rbp_bufs);
 
-        rbp->rbp_npages = npages;
-        rbp->rbp_credits = 0;
-        rbp->rbp_mincredits = 0;
+       rbp->rbp_npages = npages;
+       rbp->rbp_credits = 0;
+       rbp->rbp_mincredits = 0;
 }
 
 void
-lnet_rtrpools_free(void)
+lnet_rtrpools_free(int keep_pools)
 {
        lnet_rtrbufpool_t *rtrp;
        int               i;
@@ -1415,17 +1468,19 @@ lnet_rtrpools_free(void)
                return;
 
        cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
-               lnet_rtrpool_free_bufs(&rtrp[0]);
-               lnet_rtrpool_free_bufs(&rtrp[1]);
-               lnet_rtrpool_free_bufs(&rtrp[2]);
+               lnet_rtrpool_free_bufs(&rtrp[LNET_TINY_BUF_IDX], i);
+               lnet_rtrpool_free_bufs(&rtrp[LNET_SMALL_BUF_IDX], i);
+               lnet_rtrpool_free_bufs(&rtrp[LNET_LARGE_BUF_IDX], i);
        }
 
-       cfs_percpt_free(the_lnet.ln_rtrpools);
-       the_lnet.ln_rtrpools = NULL;
+       if (!keep_pools) {
+               cfs_percpt_free(the_lnet.ln_rtrpools);
+               the_lnet.ln_rtrpools = NULL;
+       }
 }
 
 static int
-lnet_nrb_tiny_calculate(int npages)
+lnet_nrb_tiny_calculate(void)
 {
        int     nrbs = LNET_NRB_TINY;
 
@@ -1444,7 +1499,7 @@ lnet_nrb_tiny_calculate(int npages)
 }
 
 static int
-lnet_nrb_small_calculate(int npages)
+lnet_nrb_small_calculate(void)
 {
        int     nrbs = LNET_NRB_SMALL;
 
@@ -1463,7 +1518,7 @@ lnet_nrb_small_calculate(int npages)
 }
 
 static int
-lnet_nrb_large_calculate(int npages)
+lnet_nrb_large_calculate(void)
 {
        int     nrbs = LNET_NRB_LARGE;
 
@@ -1485,38 +1540,36 @@ int
 lnet_rtrpools_alloc(int im_a_router)
 {
        lnet_rtrbufpool_t *rtrp;
-       int     large_pages = (LNET_MTU + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
-       int     small_pages = 1;
        int     nrb_tiny;
        int     nrb_small;
        int     nrb_large;
        int     rc;
        int     i;
 
-        if (!strcmp(forwarding, "")) {
-                /* not set either way */
-                if (!im_a_router)
-                        return 0;
-        } else if (!strcmp(forwarding, "disabled")) {
-                /* explicitly disabled */
-                return 0;
-        } else if (!strcmp(forwarding, "enabled")) {
-                /* explicitly enabled */
-        } else {
-                LCONSOLE_ERROR_MSG(0x10b, "'forwarding' not set to either "
-                                   "'enabled' or 'disabled'\n");
-                return -EINVAL;
-        }
+       if (!strcmp(forwarding, "")) {
+               /* not set either way */
+               if (!im_a_router)
+                       return 0;
+       } else if (!strcmp(forwarding, "disabled")) {
+               /* explicitly disabled */
+               return 0;
+       } else if (!strcmp(forwarding, "enabled")) {
+               /* explicitly enabled */
+       } else {
+               LCONSOLE_ERROR_MSG(0x10b, "'forwarding' not set to either "
+                                  "'enabled' or 'disabled'\n");
+               return -EINVAL;
+       }
 
-       nrb_tiny = lnet_nrb_tiny_calculate(0);
+       nrb_tiny = lnet_nrb_tiny_calculate();
        if (nrb_tiny < 0)
                return -EINVAL;
 
-       nrb_small = lnet_nrb_small_calculate(small_pages);
+       nrb_small = lnet_nrb_small_calculate();
        if (nrb_small < 0)
                return -EINVAL;
 
-       nrb_large = lnet_nrb_large_calculate(large_pages);
+       nrb_large = lnet_nrb_large_calculate();
        if (nrb_large < 0)
                return -EINVAL;
 
@@ -1530,18 +1583,23 @@ lnet_rtrpools_alloc(int im_a_router)
        }
 
        cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
-               lnet_rtrpool_init(&rtrp[0], 0);
-               rc = lnet_rtrpool_alloc_bufs(&rtrp[0], nrb_tiny, i);
+               lnet_rtrpool_init(&rtrp[LNET_TINY_BUF_IDX], 0);
+               rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_TINY_BUF_IDX],
+                                             nrb_tiny, i);
                if (rc != 0)
                        goto failed;
 
-               lnet_rtrpool_init(&rtrp[1], small_pages);
-               rc = lnet_rtrpool_alloc_bufs(&rtrp[1], nrb_small, i);
+               lnet_rtrpool_init(&rtrp[LNET_SMALL_BUF_IDX],
+                                 LNET_NRB_SMALL_PAGES);
+               rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_SMALL_BUF_IDX],
+                                             nrb_small, i);
                if (rc != 0)
                        goto failed;
 
-               lnet_rtrpool_init(&rtrp[2], large_pages);
-               rc = lnet_rtrpool_alloc_bufs(&rtrp[2], nrb_large, i);
+               lnet_rtrpool_init(&rtrp[LNET_LARGE_BUF_IDX],
+                                 LNET_NRB_LARGE_PAGES);
+               rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_LARGE_BUF_IDX],
+                                             nrb_large, i);
                if (rc != 0)
                        goto failed;
        }
@@ -1549,14 +1607,116 @@ lnet_rtrpools_alloc(int im_a_router)
        lnet_net_lock(LNET_LOCK_EX);
        the_lnet.ln_routing = 1;
        lnet_net_unlock(LNET_LOCK_EX);
-
        return 0;
 
  failed:
-       lnet_rtrpools_free();
+       lnet_rtrpools_free(0);
        return rc;
 }
 
+static int
+lnet_rtrpools_adjust_helper(int tiny, int small, int large)
+{
+       int nrb = 0;
+       int rc = 0;
+       int i;
+       lnet_rtrbufpool_t *rtrp;
+
+       /* If the provided values for each buffer pool are different than the
+        * configured values, we need to take action. */
+       if (tiny >= 0) {
+               tiny_router_buffers = tiny;
+               nrb = lnet_nrb_tiny_calculate();
+               cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
+                       rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_TINY_BUF_IDX],
+                                                     nrb, i);
+                       if (rc != 0)
+                               return rc;
+               }
+       }
+       if (small >= 0) {
+               small_router_buffers = small;
+               nrb = lnet_nrb_small_calculate();
+               cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
+                       rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_SMALL_BUF_IDX],
+                                                     nrb, i);
+                       if (rc != 0)
+                               return rc;
+               }
+       }
+       if (large >= 0) {
+               large_router_buffers = large;
+               nrb = lnet_nrb_large_calculate();
+               cfs_percpt_for_each(rtrp, i, the_lnet.ln_rtrpools) {
+                       rc = lnet_rtrpool_adjust_bufs(&rtrp[LNET_LARGE_BUF_IDX],
+                                                     nrb, i);
+                       if (rc != 0)
+                               return rc;
+               }
+       }
+
+       return 0;
+}
+
+int
+lnet_rtrpools_adjust(int tiny, int small, int large)
+{
+       /* this function doesn't revert the changes if adding new buffers
+        * failed.  It's up to the user space caller to revert the
+        * changes. */
+
+       if (!the_lnet.ln_routing)
+               return 0;
+
+       return lnet_rtrpools_adjust_helper(tiny, small, large);
+}
+
+int
+lnet_rtrpools_enable(void)
+{
+       int rc;
+
+       if (the_lnet.ln_routing)
+               return 0;
+
+       if (the_lnet.ln_rtrpools == NULL)
+               /* If routing is turned off, and we have never
+                * initialized the pools before, just call the
+                * standard buffer pool allocation routine as
+                * if we are just configuring this for the first
+                * time. */
+               return lnet_rtrpools_alloc(1);
+
+       rc = lnet_rtrpools_adjust_helper(0, 0, 0);
+       if (rc != 0)
+               return rc;
+
+       lnet_net_lock(LNET_LOCK_EX);
+       the_lnet.ln_routing = 1;
+
+       the_lnet.ln_ping_info->pi_features &= ~LNET_PING_FEAT_RTE_DISABLED;
+       lnet_net_unlock(LNET_LOCK_EX);
+
+       return 0;
+}
+
+void
+lnet_rtrpools_disable(void)
+{
+       if (!the_lnet.ln_routing)
+               return;
+
+       lnet_net_lock(LNET_LOCK_EX);
+       the_lnet.ln_routing = 0;
+       the_lnet.ln_ping_info->pi_features |= LNET_PING_FEAT_RTE_DISABLED;
+
+       tiny_router_buffers = 0;
+       small_router_buffers = 0;
+       large_router_buffers = 0;
+       lnet_net_unlock(LNET_LOCK_EX);
+       lnet_rtrpools_free(1);
+}
+
 int
 lnet_notify(lnet_ni_t *ni, lnet_nid_t nid, int alive, cfs_time_t when)
 {
@@ -1628,133 +1788,3 @@ lnet_notify(lnet_ni_t *ni, lnet_nid_t nid, int alive, cfs_time_t when)
        return 0;
 }
 EXPORT_SYMBOL(lnet_notify);
-
-void
-lnet_get_tunables (void)
-{
-        return;
-}
-
-#else
-
-int
-lnet_notify (lnet_ni_t *ni, lnet_nid_t nid, int alive, cfs_time_t when)
-{
-        return -EOPNOTSUPP;
-}
-
-void
-lnet_router_checker (void)
-{
-        static time_t last = 0;
-        static int    running = 0;
-
-        time_t            now = cfs_time_current_sec();
-        int               interval = now - last;
-        int               rc;
-        __u64             version;
-        lnet_peer_t      *rtr;
-
-        /* It's no use to call me again within a sec - all intervals and
-         * timeouts are measured in seconds */
-        if (last != 0 && interval < 2)
-                return;
-
-        if (last != 0 &&
-            interval > MAX(live_router_check_interval,
-                           dead_router_check_interval))
-                CNETERR("Checker(%d/%d) not called for %d seconds\n",
-                        live_router_check_interval, dead_router_check_interval,
-                        interval);
-
-       LASSERT(LNET_CPT_NUMBER == 1);
-
-       lnet_net_lock(0);
-       LASSERT(!running); /* recursion check */
-       running = 1;
-       lnet_net_unlock(0);
-
-       last = now;
-
-       if (the_lnet.ln_rc_state == LNET_RC_STATE_STOPPING)
-               lnet_prune_rc_data(0); /* unlink all rcd and nowait */
-
-        /* consume all pending events */
-        while (1) {
-                int          i;
-                lnet_event_t ev;
-
-                /* NB ln_rc_eqh must be the 1st in 'eventqs' otherwise the
-                 * recursion breaker in LNetEQPoll would fail */
-                rc = LNetEQPoll(&the_lnet.ln_rc_eqh, 1, 0, &ev, &i);
-                if (rc == 0)   /* no event pending */
-                        break;
-
-                /* NB a lost SENT prevents me from pinging a router again */
-                if (rc == -EOVERFLOW) {
-                        CERROR("Dropped an event!!!\n");
-                        abort();
-                }
-
-                LASSERT (rc == 1);
-
-                lnet_router_checker_event(&ev);
-        }
-
-       if (the_lnet.ln_rc_state == LNET_RC_STATE_STOPPING) {
-               lnet_prune_rc_data(1); /* release rcd */
-               the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
-                running = 0;
-                return;
-        }
-
-        LASSERT (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
-
-       lnet_net_lock(0);
-
-       version = the_lnet.ln_routers_version;
-       list_for_each_entry(rtr, &the_lnet.ln_routers, lp_rtr_list) {
-               lnet_ping_router_locked(rtr);
-               LASSERT(version == the_lnet.ln_routers_version);
-       }
-
-       lnet_net_unlock(0);
-
-       running = 0; /* lock only needed for the recursion check */
-       return;
-}
-
-/* NB lnet_peers_start_down depends on me,
- * so must be called before any peer creation */
-void
-lnet_get_tunables (void)
-{
-        char *s;
-
-        s = getenv("LNET_ROUTER_PING_TIMEOUT");
-        if (s != NULL) router_ping_timeout = atoi(s);
-
-        s = getenv("LNET_LIVE_ROUTER_CHECK_INTERVAL");
-        if (s != NULL) live_router_check_interval = atoi(s);
-
-        s = getenv("LNET_DEAD_ROUTER_CHECK_INTERVAL");
-        if (s != NULL) dead_router_check_interval = atoi(s);
-
-        /* This replaces old lnd_notify mechanism */
-        check_routers_before_use = 1;
-        if (dead_router_check_interval <= 0)
-                dead_router_check_interval = 30;
-}
-
-void
-lnet_rtrpools_free(void)
-{
-}
-
-int
-lnet_rtrpools_alloc(int im_a_arouter)
-{
-        return 0;
-}
-
-#endif