Whamcloud - gitweb
LU-11299 lnet: lnet_add/del_route()
[fs/lustre-release.git] / lnet / lnet / router.c
index 24fe7e7..4aefdf1 100644 (file)
@@ -3,7 +3,7 @@
  *
  * Copyright (c) 2011, 2017, Intel Corporation.
  *
- *   This file is part of Lustre, https://wiki.hpdd.intel.com/
+ *   This file is part of Lustre, https://wiki.whamcloud.com/
  *
  *   Portals is free software; you can redistribute it and/or
  *   modify it under the terms of version 2 of the GNU General Public
@@ -21,6 +21,8 @@
  */
 
 #define DEBUG_SUBSYSTEM S_LNET
+
+#include <linux/random.h>
 #include <lnet/lib-lnet.h>
 
 #define LNET_NRB_TINY_MIN      512     /* min value for each CPT */
@@ -68,9 +70,6 @@ lnet_peer_buffer_credits(struct lnet_net *net)
        return net->net_tunables.lct_peer_tx_credits;
 }
 
-/* forward ref's */
-static int lnet_router_checker(void *);
-
 static int check_routers_before_use;
 module_param(check_routers_before_use, int, 0444);
 MODULE_PARM_DESC(check_routers_before_use, "Assume routers are down and ping them before use");
@@ -115,7 +114,6 @@ lnet_notify_locked(struct lnet_peer_ni *lp, int notifylnd, int alive,
        spin_lock(&lp->lpni_lock);
 
        lp->lpni_timestamp = when; /* update timestamp */
-       lp->lpni_ping_deadline = 0;               /* disable ping timeout */
 
        if (lp->lpni_alive_count != 0 &&          /* got old news */
            (!lp->lpni_alive) == (!alive)) {      /* new date for old news */
@@ -191,53 +189,34 @@ lnet_ni_notify_locked(struct lnet_ni *ni, struct lnet_peer_ni *lp)
 }
 
 static void
-lnet_rtr_addref_locked(struct lnet_peer_ni *lp)
+lnet_rtr_addref_locked(struct lnet_peer *lp)
 {
-       LASSERT(atomic_read(&lp->lpni_refcount) > 0);
-       LASSERT(lp->lpni_rtr_refcount >= 0);
+       LASSERT(lp->lp_rtr_refcount >= 0);
 
        /* lnet_net_lock must be exclusively locked */
-       lp->lpni_rtr_refcount++;
-       if (lp->lpni_rtr_refcount == 1) {
-               struct list_head *pos;
-
-               /* a simple insertion sort */
-               list_for_each_prev(pos, &the_lnet.ln_routers) {
-                       struct lnet_peer_ni *rtr;
-
-                       rtr = list_entry(pos, struct lnet_peer_ni,
-                                        lpni_rtr_list);
-                       if (rtr->lpni_nid < lp->lpni_nid)
-                               break;
-               }
-
-               list_add(&lp->lpni_rtr_list, pos);
+       lp->lp_rtr_refcount++;
+       if (lp->lp_rtr_refcount == 1) {
+               list_add_tail(&lp->lp_rtr_list, &the_lnet.ln_routers);
                /* addref for the_lnet.ln_routers */
-               lnet_peer_ni_addref_locked(lp);
+               lnet_peer_addref_locked(lp);
                the_lnet.ln_routers_version++;
        }
 }
 
 static void
-lnet_rtr_decref_locked(struct lnet_peer_ni *lp)
+lnet_rtr_decref_locked(struct lnet_peer *lp)
 {
-       LASSERT(atomic_read(&lp->lpni_refcount) > 0);
-       LASSERT(lp->lpni_rtr_refcount > 0);
+       LASSERT(atomic_read(&lp->lp_refcount) > 0);
+       LASSERT(lp->lp_rtr_refcount > 0);
 
        /* lnet_net_lock must be exclusively locked */
-       lp->lpni_rtr_refcount--;
-       if (lp->lpni_rtr_refcount == 0) {
-               LASSERT(list_empty(&lp->lpni_routes));
-
-               if (lp->lpni_rcd != NULL) {
-                       list_add(&lp->lpni_rcd->rcd_list,
-                                &the_lnet.ln_rcd_deathrow);
-                       lp->lpni_rcd = NULL;
-               }
+       lp->lp_rtr_refcount--;
+       if (lp->lp_rtr_refcount == 0) {
+               LASSERT(list_empty(&lp->lp_routes));
 
-               list_del(&lp->lpni_rtr_list);
+               list_del(&lp->lp_rtr_list);
                /* decref for the_lnet.ln_routers */
-               lnet_peer_ni_decref_locked(lp);
+               lnet_peer_decref_locked(lp);
                the_lnet.ln_routers_version++;
        }
 }
@@ -264,27 +243,16 @@ lnet_find_rnet_locked(__u32 net)
 static void lnet_shuffle_seed(void)
 {
        static int seeded;
-       __u32 lnd_type;
-       __u32 seed[2];
-       struct timespec64 ts;
        struct lnet_ni *ni = NULL;
 
        if (seeded)
                return;
 
-       cfs_get_random_bytes(seed, sizeof(seed));
-
        /* Nodes with small feet have little entropy
         * the NID for this node gives the most entropy in the low bits */
-       while ((ni = lnet_get_next_ni_locked(NULL, ni))) {
-               lnd_type = LNET_NETTYP(LNET_NIDNET(ni->ni_nid));
-
-               if (lnd_type != LOLND)
-                       seed[0] ^= (LNET_NIDADDR(ni->ni_nid) | lnd_type);
-       }
+       while ((ni = lnet_get_next_ni_locked(NULL, ni)))
+               add_device_randomness(&ni->ni_nid, sizeof(ni->ni_nid));
 
-       ktime_get_ts64(&ts);
-       cfs_srand(ts.tv_sec ^ seed[0], ts.tv_nsec ^ seed[1]);
        seeded = 1;
        return;
 }
@@ -293,17 +261,20 @@ static void lnet_shuffle_seed(void)
 static void
 lnet_add_route_to_rnet(struct lnet_remotenet *rnet, struct lnet_route *route)
 {
-       unsigned int      len = 0;
-       unsigned int      offset = 0;
+       unsigned int len = 0;
+       unsigned int offset = 0;
        struct list_head *e;
 
        lnet_shuffle_seed();
 
-       list_for_each(e, &rnet->lrn_routes) {
+       list_for_each(e, &rnet->lrn_routes)
                len++;
-       }
 
-       /* len+1 positions to add a new entry, also prevents division by 0 */
+       /*
+        * Randomly adding routes to the list is done to ensure that when
+        * different nodes are using the same list of routers, they end up
+        * preferring different routers.
+        */
        offset = cfs_rand() % (len + 1);
        list_for_each(e, &rnet->lrn_routes) {
                if (offset == 0)
@@ -311,9 +282,18 @@ lnet_add_route_to_rnet(struct lnet_remotenet *rnet, struct lnet_route *route)
                offset--;
        }
        list_add(&route->lr_list, e);
-       list_add(&route->lr_gwlist, &route->lr_gateway->lpni_routes);
+       /*
+        * force a router check on the gateway to make sure the route is
+        * alive
+        */
+       route->lr_gateway->lp_rtrcheck_timestamp = 0;
 
        the_lnet.ln_remote_nets_version++;
+
+       /* add the route on the gateway list */
+       list_add(&route->lr_gwlist, &route->lr_gateway->lp_routes);
+
+       /* take a router reference count on the gateway */
        lnet_rtr_addref_locked(route->lr_gateway);
 }
 
@@ -321,16 +301,16 @@ int
 lnet_add_route(__u32 net, __u32 hops, lnet_nid_t gateway,
               unsigned int priority)
 {
-       struct list_head        *e;
-       struct lnet_remotenet   *rnet;
-       struct lnet_remotenet   *rnet2;
-       struct lnet_route               *route;
-       struct lnet_ni          *ni;
-       struct lnet_peer_ni     *lpni;
-       int                     add_route;
-       int                     rc;
-
-       CDEBUG(D_NET, "Add route: net %s hops %d priority %u gw %s\n",
+       struct list_head *route_entry;
+       struct lnet_remotenet *rnet;
+       struct lnet_remotenet *rnet2;
+       struct lnet_route *route;
+       struct lnet_peer_ni *lpni;
+       struct lnet_peer *gw;
+       int add_route;
+       int rc;
+
+       CDEBUG(D_NET, "Add route: remote net %s hops %d priority %u gw %s\n",
               libcfs_net2str(net), hops, priority, libcfs_nid2str(gateway));
 
        if (gateway == LNET_NID_ANY ||
@@ -341,7 +321,8 @@ lnet_add_route(__u32 net, __u32 hops, lnet_nid_t gateway,
            (hops != LNET_UNDEFINED_HOPS && (hops < 1 || hops > 255)))
                return -EINVAL;
 
-       if (lnet_islocalnet(net))       /* it's a local network */
+       /* it's a local network */
+       if (lnet_islocalnet(net))
                return -EEXIST;
 
        /* Assume net, route, all new */
@@ -359,12 +340,18 @@ lnet_add_route(__u32 net, __u32 hops, lnet_nid_t gateway,
 
        INIT_LIST_HEAD(&rnet->lrn_routes);
        rnet->lrn_net = net;
-       route->lr_hops = hops;
+       /* store the local and remote net that the route represents */
+       route->lr_lnet = LNET_NIDNET(gateway);
        route->lr_net = net;
        route->lr_priority = priority;
+       route->lr_hops = hops;
 
        lnet_net_lock(LNET_LOCK_EX);
 
+       /*
+        * lnet_nid2peerni_ex() grabs a ref on the lpni. We will need to
+        * lose that once we're done
+        */
        lpni = lnet_nid2peerni_ex(gateway, LNET_LOCK_EX);
        if (IS_ERR(lpni)) {
                lnet_net_unlock(LNET_LOCK_EX);
@@ -373,15 +360,16 @@ lnet_add_route(__u32 net, __u32 hops, lnet_nid_t gateway,
                LIBCFS_FREE(rnet, sizeof(*rnet));
 
                rc = PTR_ERR(lpni);
-               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;
        }
-       route->lr_gateway = lpni;
-       LASSERT(the_lnet.ln_state == LNET_STATE_RUNNING);
+
+       LASSERT(lpni->lpni_peer_net && lpni->lpni_peer_net->lpn_peer);
+       gw = lpni->lpni_peer_net->lpn_peer;
+
+       route->lr_gateway = gw;
 
        rnet2 = lnet_find_rnet_locked(net);
        if (rnet2 == NULL) {
@@ -392,35 +380,34 @@ lnet_add_route(__u32 net, __u32 hops, lnet_nid_t gateway,
 
        /* Search for a duplicate route (it's a NOOP if it is) */
        add_route = 1;
-       list_for_each(e, &rnet2->lrn_routes) {
+       list_for_each(route_entry, &rnet2->lrn_routes) {
                struct lnet_route *route2;
 
-               route2 = list_entry(e, struct lnet_route, lr_list);
+               route2 = list_entry(route_entry, struct lnet_route, lr_list);
                if (route2->lr_gateway == route->lr_gateway) {
                        add_route = 0;
                        break;
                }
 
                /* our lookups must be true */
-               LASSERT(route2->lr_gateway->lpni_nid != gateway);
+               LASSERT(route2->lr_gateway->lp_primary_nid != gateway);
        }
 
-       if (add_route) {
-               lnet_peer_ni_addref_locked(route->lr_gateway); /* +1 for notify */
+       /*
+        * It is possible to add multiple routes through the same peer,
+        * but it'll be using a different NID of that peer. When the
+        * gateway is discovered, discovery will consolidate the different
+        * peers into one peer. In this case the discovery code will have
+        * to move the routes from the peer that's being deleted to the
+        * consolidated peer lp_routes list
+        */
+       if (add_route)
                lnet_add_route_to_rnet(rnet2, route);
 
-               ni = lnet_get_next_ni_locked(route->lr_gateway->lpni_net, NULL);
-               lnet_net_unlock(LNET_LOCK_EX);
-
-               /* XXX Assume alive */
-               if (ni->ni_net->net_lnd->lnd_notify != NULL)
-                       (ni->ni_net->net_lnd->lnd_notify)(ni, gateway, 1);
-
-               lnet_net_lock(LNET_LOCK_EX);
-       }
-
-       /* -1 for notify or !add_route */
-       lnet_peer_ni_decref_locked(route->lr_gateway);
+       /*
+        * get rid of the reference on the lpni.
+        */
+       lnet_peer_ni_decref_locked(lpni);
        lnet_net_unlock(LNET_LOCK_EX);
 
        rc = 0;
@@ -433,80 +420,57 @@ lnet_add_route(__u32 net, __u32 hops, lnet_nid_t gateway,
        if (rnet != rnet2)
                LIBCFS_FREE(rnet, sizeof(*rnet));
 
-       /* indicate to startup the router checker if configured */
-       wake_up(&the_lnet.ln_rc_waitq);
+       /* kick start the monitor thread to handle the added route */
+       wake_up(&the_lnet.ln_mt_waitq);
 
        return rc;
 }
 
-int
-lnet_check_routes(void)
+static void
+lnet_del_route_from_rnet(lnet_nid_t gw_nid, struct list_head *route_list,
+                        struct list_head *zombies)
 {
-       struct lnet_remotenet *rnet;
-       struct lnet_route        *route;
-       struct lnet_route        *route2;
-       struct list_head *e1;
-       struct list_head *e2;
-       int               cpt;
-       struct list_head *rn_list;
-       int               i;
-
-       cpt = lnet_net_lock_current();
-
-       for (i = 0; i < LNET_REMOTE_NETS_HASH_SIZE; i++) {
-               rn_list = &the_lnet.ln_remote_nets_hash[i];
-               list_for_each(e1, rn_list) {
-                       rnet = list_entry(e1, struct lnet_remotenet, lrn_list);
-
-                       route2 = NULL;
-                       list_for_each(e2, &rnet->lrn_routes) {
-                               lnet_nid_t      nid1;
-                               lnet_nid_t      nid2;
-                               int             net;
-
-                               route = list_entry(e2, struct lnet_route,
-                                                  lr_list);
-
-                               if (route2 == NULL) {
-                                       route2 = route;
-                                       continue;
-                               }
-
-                               if (route->lr_gateway->lpni_net ==
-                                   route2->lr_gateway->lpni_net)
-                                       continue;
-
-                               nid1 = route->lr_gateway->lpni_nid;
-                               nid2 = route2->lr_gateway->lpni_nid;
-                               net = rnet->lrn_net;
+       struct lnet_peer *gateway;
+       struct lnet_route *route;
+       struct lnet_route *tmp;
+
+       list_for_each_entry_safe(route, tmp, route_list, lr_list) {
+               gateway = route->lr_gateway;
+               if (gw_nid != LNET_NID_ANY &&
+                   gw_nid != gateway->lp_primary_nid)
+                       continue;
 
-                               lnet_net_unlock(cpt);
+               /*
+                * move to zombie to delete outside the lock
+                * Note that this function is called with the
+                * ln_api_mutex held as well as the exclusive net
+                * lock. Adding to the remote net list happens
+                * under the same conditions. Same goes for the
+                * gateway router list
+                */
+               list_move(&route->lr_list, zombies);
+               the_lnet.ln_remote_nets_version++;
 
-                               CERROR("Routes to %s via %s and %s not "
-                                      "supported\n",
-                                      libcfs_net2str(net),
-                                      libcfs_nid2str(nid1),
-                                      libcfs_nid2str(nid2));
-                               return -EINVAL;
-                       }
-               }
+               list_del(&route->lr_gwlist);
+               lnet_rtr_decref_locked(gateway);
        }
-
-       lnet_net_unlock(cpt);
-       return 0;
 }
 
 int
 lnet_del_route(__u32 net, lnet_nid_t gw_nid)
 {
-       struct lnet_peer_ni     *gateway;
-       struct lnet_remotenet   *rnet;
-       struct lnet_route               *route;
-       struct list_head        *e1;
-       struct list_head        *e2;
-       int                     rc = -ENOENT;
-       struct list_head        *rn_list;
-       int                     idx = 0;
+       struct list_head rnet_zombies;
+       struct lnet_remotenet *rnet;
+       struct lnet_remotenet *tmp;
+       struct list_head *rn_list;
+       struct lnet_peer_ni *lpni;
+       struct lnet_route *route;
+       struct list_head zombies;
+       struct lnet_peer *lp;
+       int i = 0;
+
+       INIT_LIST_HEAD(&rnet_zombies);
+       INIT_LIST_HEAD(&zombies);
 
        CDEBUG(D_NET, "Del route: net %s : gw %s\n",
               libcfs_net2str(net), libcfs_nid2str(gw_nid));
@@ -515,60 +479,56 @@ lnet_del_route(__u32 net, lnet_nid_t gw_nid)
         * or a specific route entry actual NIDs) */
 
        lnet_net_lock(LNET_LOCK_EX);
-       if (net == LNET_NIDNET(LNET_NID_ANY))
-               rn_list = &the_lnet.ln_remote_nets_hash[0];
-       else
-               rn_list = lnet_net2rnethash(net);
 
-again:
-       list_for_each(e1, rn_list) {
-               rnet = list_entry(e1, struct lnet_remotenet, lrn_list);
-
-               if (!(net == LNET_NIDNET(LNET_NID_ANY) ||
-                       net == rnet->lrn_net))
-                       continue;
-
-               list_for_each(e2, &rnet->lrn_routes) {
-                       route = list_entry(e2, struct lnet_route, lr_list);
+       lpni = lnet_find_peer_ni_locked(gw_nid);
+       if (lpni) {
+               lp = lpni->lpni_peer_net->lpn_peer;
+               LASSERT(lp);
+               gw_nid = lp->lp_primary_nid;
+               lnet_peer_ni_decref_locked(lpni);
+       }
 
-                       gateway = route->lr_gateway;
-                       if (!(gw_nid == LNET_NID_ANY ||
-                             gw_nid == gateway->lpni_nid))
-                               continue;
+       if (net != LNET_NIDNET(LNET_NID_ANY)) {
+               rnet = lnet_find_rnet_locked(net);
+               if (!rnet) {
+                       lnet_net_unlock(LNET_LOCK_EX);
+                       return -ENOENT;
+               }
+               lnet_del_route_from_rnet(gw_nid, &rnet->lrn_routes,
+                                        &zombies);
+               if (list_empty(&rnet->lrn_routes))
+                       list_move(&rnet->lrn_list, &rnet_zombies);
+               goto delete_zombies;
+       }
 
-                       list_del(&route->lr_list);
-                       list_del(&route->lr_gwlist);
-                       the_lnet.ln_remote_nets_version++;
+       for (i = 0; i < LNET_REMOTE_NETS_HASH_SIZE; i++) {
+               rn_list = &the_lnet.ln_remote_nets_hash[i];
 
+               list_for_each_entry_safe(rnet, tmp, rn_list, lrn_list) {
+                       lnet_del_route_from_rnet(gw_nid, &rnet->lrn_routes,
+                                                &zombies);
                        if (list_empty(&rnet->lrn_routes))
-                               list_del(&rnet->lrn_list);
-                       else
-                               rnet = NULL;
-
-                       lnet_rtr_decref_locked(gateway);
-                       lnet_peer_ni_decref_locked(gateway);
-
-                       lnet_net_unlock(LNET_LOCK_EX);
-
-                       LIBCFS_FREE(route, sizeof(*route));
+                               list_move(&rnet->lrn_list, &rnet_zombies);
+               }
+       }
 
-                       if (rnet != NULL)
-                               LIBCFS_FREE(rnet, sizeof(*rnet));
+delete_zombies:
+       lnet_net_unlock(LNET_LOCK_EX);
 
-                       rc = 0;
-                       lnet_net_lock(LNET_LOCK_EX);
-                       goto again;
-               }
+       while (!list_empty(&zombies)) {
+               route = list_first_entry(&zombies, struct lnet_route, lr_list);
+               list_del(&route->lr_list);
+               LIBCFS_FREE(route, sizeof(*route));
        }
 
-       if (net == LNET_NIDNET(LNET_NID_ANY) &&
-           ++idx < LNET_REMOTE_NETS_HASH_SIZE) {
-               rn_list = &the_lnet.ln_remote_nets_hash[idx];
-               goto again;
+       while (!list_empty(&rnet_zombies)) {
+               rnet = list_first_entry(&rnet_zombies, struct lnet_remotenet,
+                                       lrn_list);
+               list_del(&rnet->lrn_list);
+               LIBCFS_FREE(rnet, sizeof(*rnet));
        }
-       lnet_net_unlock(LNET_LOCK_EX);
 
-       return rc;
+       return 0;
 }
 
 void
@@ -577,29 +537,29 @@ 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 lnet_get_rtr_pool_cfg(int cpt, struct lnet_ioctl_pool_cfg *pool_cfg)
 {
+       struct lnet_rtrbufpool *rbp;
        int i, rc = -ENOENT, j;
 
        if (the_lnet.ln_rtrpools == NULL)
                return rc;
 
-       for (i = 0; i < LNET_NRBPOOLS; i++) {
-               struct lnet_rtrbufpool *rbp;
 
-               lnet_net_lock(LNET_LOCK_EX);
-               cfs_percpt_for_each(rbp, j, the_lnet.ln_rtrpools) {
-                       if (i++ != idx)
-                               continue;
+       cfs_percpt_for_each(rbp, i, the_lnet.ln_rtrpools) {
+               if (i != cpt)
+                       continue;
 
-                       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;
-                       rc = 0;
-                       break;
+               lnet_net_lock(i);
+               for (j = 0; j < LNET_NRBPOOLS; j++) {
+                       pool_cfg->pl_pools[j].pl_npages = rbp[j].rbp_npages;
+                       pool_cfg->pl_pools[j].pl_nbuffers = rbp[j].rbp_nbuffers;
+                       pool_cfg->pl_pools[j].pl_credits = rbp[j].rbp_credits;
+                       pool_cfg->pl_pools[j].pl_mincredits = rbp[j].rbp_mincredits;
                }
-               lnet_net_unlock(LNET_LOCK_EX);
+               lnet_net_unlock(i);
+               rc = 0;
+               break;
        }
 
        lnet_net_lock(LNET_LOCK_EX);
@@ -636,7 +596,7 @@ lnet_get_route(int idx, __u32 *net, __u32 *hops,
                                        *net      = rnet->lrn_net;
                                        *hops     = route->lr_hops;
                                        *priority = route->lr_priority;
-                                       *gateway  = route->lr_gateway->lpni_nid;
+                                       *gateway  = route->lr_gateway->lp_primary_nid;
                                        *alive    = lnet_is_route_alive(route);
                                        lnet_net_unlock(cpt);
                                        return 0;
@@ -672,108 +632,12 @@ lnet_swap_pinginfo(struct lnet_ping_buffer *pbuf)
 }
 
 /**
- * parse router-checker pinginfo, record number of down NIs for remote
- * networks on that router.
+ * TODO: re-implement
  */
 static void
 lnet_parse_rc_info(struct lnet_rc_data *rcd)
 {
-       struct lnet_ping_buffer *pbuf = rcd->rcd_pingbuffer;
-       struct lnet_peer_ni     *gw   = rcd->rcd_gateway;
-       struct lnet_route               *rte;
-       int                     nnis;
-
-       if (!gw->lpni_alive || !pbuf)
-               return;
-
-       /*
-        * Protect gw->lpni_ping_feats. This can be set from
-        * lnet_notify_locked with different locks being held
-        */
-       spin_lock(&gw->lpni_lock);
-
-       if (pbuf->pb_info.pi_magic == __swab32(LNET_PROTO_PING_MAGIC))
-               lnet_swap_pinginfo(pbuf);
-
-       /* NB always racing with network! */
-       if (pbuf->pb_info.pi_magic != LNET_PROTO_PING_MAGIC) {
-               CDEBUG(D_NET, "%s: Unexpected magic %08x\n",
-                      libcfs_nid2str(gw->lpni_nid), pbuf->pb_info.pi_magic);
-               gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
-               goto out;
-       }
-
-       gw->lpni_ping_feats = pbuf->pb_info.pi_features;
-
-       /* Without NI status info there's nothing more to do. */
-       if ((gw->lpni_ping_feats & LNET_PING_FEAT_NI_STATUS) == 0)
-               goto out;
-
-       /* Determine the number of NIs for which there is data. */
-       nnis = pbuf->pb_info.pi_nnis;
-       if (pbuf->pb_nnis < nnis) {
-               if (rcd->rcd_nnis < nnis)
-                       rcd->rcd_nnis = nnis;
-               nnis = pbuf->pb_nnis;
-       }
-
-       list_for_each_entry(rte, &gw->lpni_routes, lr_gwlist) {
-               int     down = 0;
-               int     up = 0;
-               int     i;
-
-               /* If routing disabled then the route is down. */
-               if ((gw->lpni_ping_feats & LNET_PING_FEAT_RTE_DISABLED) != 0) {
-                       rte->lr_downis = 1;
-                       continue;
-               }
-
-               for (i = 0; i < nnis; i++) {
-                       struct lnet_ni_status *stat = &pbuf->pb_info.pi_ni[i];
-                       lnet_nid_t       nid = stat->ns_nid;
-
-                       if (nid == LNET_NID_ANY) {
-                               CDEBUG(D_NET, "%s: unexpected LNET_NID_ANY\n",
-                                      libcfs_nid2str(gw->lpni_nid));
-                               gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
-                               goto out;
-                       }
-
-                       if (LNET_NETTYP(LNET_NIDNET(nid)) == LOLND)
-                               continue;
-
-                       if (stat->ns_status == LNET_NI_STATUS_DOWN) {
-                               down++;
-                               continue;
-                       }
-
-                       if (stat->ns_status == LNET_NI_STATUS_UP) {
-                               if (LNET_NIDNET(nid) == rte->lr_net) {
-                                       up = 1;
-                                       break;
-                               }
-                               continue;
-                       }
-
-                       CDEBUG(D_NET, "%s: Unexpected status 0x%x\n",
-                              libcfs_nid2str(gw->lpni_nid), stat->ns_status);
-                       gw->lpni_ping_feats = LNET_PING_FEAT_INVAL;
-                       goto out;
-               }
-
-               if (up) { /* ignore downed NIs if NI for dest network is up */
-                       rte->lr_downis = 0;
-                       continue;
-               }
-               /* 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;
-       }
-out:
-       spin_unlock(&gw->lpni_lock);
+       rcd = rcd;
 }
 
 static void
@@ -805,7 +669,6 @@ lnet_router_checker_event(struct lnet_event *event)
        }
 
        if (event->type == LNET_EVENT_SEND) {
-               lp->lpni_ping_notsent = 0;
                if (event->status == 0)
                        goto out;
        }
@@ -832,28 +695,28 @@ lnet_router_checker_event(struct lnet_event *event)
 static void
 lnet_wait_known_routerstate(void)
 {
-       struct lnet_peer_ni *rtr;
+       struct lnet_peer *rtr;
        struct list_head *entry;
        int all_known;
 
-       LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING);
+       LASSERT(the_lnet.ln_mt_state == LNET_MT_STATE_RUNNING);
 
        for (;;) {
                int cpt = lnet_net_lock_current();
 
                all_known = 1;
                list_for_each(entry, &the_lnet.ln_routers) {
-                       rtr = list_entry(entry, struct lnet_peer_ni,
-                                        lpni_rtr_list);
+                       rtr = list_entry(entry, struct lnet_peer,
+                                        lp_rtr_list);
 
-                       spin_lock(&rtr->lpni_lock);
+                       spin_lock(&rtr->lp_lock);
 
-                       if (rtr->lpni_alive_count == 0) {
+                       if ((rtr->lp_state & LNET_PEER_DISCOVERED) == 0) {
                                all_known = 0;
-                               spin_unlock(&rtr->lpni_lock);
+                               spin_unlock(&rtr->lp_lock);
                                break;
                        }
-                       spin_unlock(&rtr->lpni_lock);
+                       spin_unlock(&rtr->lp_lock);
                }
 
                lnet_net_unlock(cpt);
@@ -866,17 +729,22 @@ lnet_wait_known_routerstate(void)
        }
 }
 
+/* TODO: reimplement */
 void
 lnet_router_ni_update_locked(struct lnet_peer_ni *gw, __u32 net)
 {
        struct lnet_route *rte;
+       struct lnet_peer *lp;
 
-       if ((gw->lpni_ping_feats & LNET_PING_FEAT_NI_STATUS) != 0) {
-               list_for_each_entry(rte, &gw->lpni_routes, lr_gwlist) {
-                       if (rte->lr_net == net) {
-                               rte->lr_downis = 0;
-                               break;
-                       }
+       if ((gw->lpni_ping_feats & LNET_PING_FEAT_NI_STATUS) != 0)
+               lp = gw->lpni_peer_net->lpn_peer;
+       else
+               return;
+
+       list_for_each_entry(rte, &lp->lp_routes, lr_gwlist) {
+               if (rte->lr_net == net) {
+                       rte->lr_downis = 0;
+                       break;
                }
        }
 }
@@ -921,214 +789,9 @@ lnet_update_ni_status_locked(void)
        }
 }
 
-static void
-lnet_destroy_rc_data(struct lnet_rc_data *rcd)
-{
-       LASSERT(list_empty(&rcd->rcd_list));
-       /* detached from network */
-       LASSERT(LNetMDHandleIsInvalid(rcd->rcd_mdh));
-
-       if (rcd->rcd_gateway != NULL) {
-               int cpt = rcd->rcd_gateway->lpni_cpt;
-
-               lnet_net_lock(cpt);
-               lnet_peer_ni_decref_locked(rcd->rcd_gateway);
-               lnet_net_unlock(cpt);
-       }
-
-       if (rcd->rcd_pingbuffer != NULL)
-               lnet_ping_buffer_decref(rcd->rcd_pingbuffer);
-
-       LIBCFS_FREE(rcd, sizeof(*rcd));
-}
-
-static struct lnet_rc_data *
-lnet_update_rc_data_locked(struct lnet_peer_ni *gateway)
+int lnet_router_pre_mt_start(void)
 {
-       struct lnet_handle_md mdh;
-       struct lnet_rc_data *rcd;
-       struct lnet_ping_buffer *pbuf = NULL;
-       int nnis = LNET_INTERFACES_MIN;
        int rc;
-       int i;
-
-       rcd = gateway->lpni_rcd;
-       if (rcd) {
-               nnis = rcd->rcd_nnis;
-               mdh = rcd->rcd_mdh;
-               LNetInvalidateMDHandle(&rcd->rcd_mdh);
-               pbuf = rcd->rcd_pingbuffer;
-               rcd->rcd_pingbuffer = NULL;
-       } else {
-               LNetInvalidateMDHandle(&mdh);
-       }
-
-       lnet_net_unlock(gateway->lpni_cpt);
-
-       if (rcd) {
-               LNetMDUnlink(mdh);
-               lnet_ping_buffer_decref(pbuf);
-       } else {
-               LIBCFS_ALLOC(rcd, sizeof(*rcd));
-               if (rcd == NULL)
-                       goto out;
-
-               LNetInvalidateMDHandle(&rcd->rcd_mdh);
-               INIT_LIST_HEAD(&rcd->rcd_list);
-               rcd->rcd_nnis = nnis;
-       }
-
-       pbuf = lnet_ping_buffer_alloc(nnis, GFP_NOFS);
-       if (pbuf == NULL)
-               goto out;
-
-       for (i = 0; i < nnis; i++) {
-               pbuf->pb_info.pi_ni[i].ns_nid = LNET_NID_ANY;
-               pbuf->pb_info.pi_ni[i].ns_status = LNET_NI_STATUS_INVALID;
-       }
-       rcd->rcd_pingbuffer = pbuf;
-
-       LASSERT(!LNetEQHandleIsInvalid(the_lnet.ln_rc_eqh));
-       rc = LNetMDBind((struct lnet_md){.start     = &pbuf->pb_info,
-                                   .user_ptr  = rcd,
-                                   .length    = LNET_PING_INFO_SIZE(nnis),
-                                   .threshold = LNET_MD_THRESH_INF,
-                                   .options   = LNET_MD_TRUNCATE,
-                                   .eq_handle = the_lnet.ln_rc_eqh},
-                       LNET_UNLINK,
-                       &rcd->rcd_mdh);
-       if (rc < 0) {
-               CERROR("Can't bind MD: %d\n", rc);
-               goto out_ping_buffer_decref;
-       }
-       LASSERT(rc == 0);
-
-       lnet_net_lock(gateway->lpni_cpt);
-       /* Check if this is still a router. */
-       if (!lnet_isrouter(gateway))
-               goto out_unlock;
-       /* Check if someone else installed router data. */
-       if (gateway->lpni_rcd && gateway->lpni_rcd != rcd)
-               goto out_unlock;
-
-       /* Install and/or update the router data. */
-       if (!gateway->lpni_rcd) {
-               lnet_peer_ni_addref_locked(gateway);
-               rcd->rcd_gateway = gateway;
-               gateway->lpni_rcd = rcd;
-       }
-       gateway->lpni_ping_notsent = 0;
-
-       return rcd;
-
-out_unlock:
-       lnet_net_unlock(gateway->lpni_cpt);
-       rc = LNetMDUnlink(mdh);
-       LASSERT(rc == 0);
-out_ping_buffer_decref:
-       lnet_ping_buffer_decref(pbuf);
-out:
-       if (rcd && rcd != gateway->lpni_rcd)
-               lnet_destroy_rc_data(rcd);
-       lnet_net_lock(gateway->lpni_cpt);
-       return gateway->lpni_rcd;
-}
-
-static int
-lnet_router_check_interval(struct lnet_peer_ni *rtr)
-{
-       int secs;
-
-       secs = rtr->lpni_alive ? live_router_check_interval :
-                              dead_router_check_interval;
-       if (secs < 0)
-               secs = 0;
-
-       return secs;
-}
-
-static void
-lnet_ping_router_locked(struct lnet_peer_ni *rtr)
-{
-       struct lnet_rc_data *rcd = NULL;
-       time64_t now = ktime_get_seconds();
-       time64_t secs;
-       struct lnet_ni *ni;
-
-       lnet_peer_ni_addref_locked(rtr);
-
-       if (rtr->lpni_ping_deadline != 0 && /* ping timed out? */
-           now >  rtr->lpni_ping_deadline)
-               lnet_notify_locked(rtr, 1, 0, now);
-
-       /* Run any outstanding notifications */
-       ni = lnet_get_next_ni_locked(rtr->lpni_net, NULL);
-       lnet_ni_notify_locked(ni, rtr);
-
-       if (!lnet_isrouter(rtr) ||
-           the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING) {
-               /* router table changed or router checker is shutting down */
-               lnet_peer_ni_decref_locked(rtr);
-               return;
-       }
-
-       rcd = rtr->lpni_rcd;
-       if (!rcd || rcd->rcd_nnis > rcd->rcd_pingbuffer->pb_nnis)
-               rcd = lnet_update_rc_data_locked(rtr);
-       if (rcd == NULL)
-               return;
-
-       secs = lnet_router_check_interval(rtr);
-
-       CDEBUG(D_NET,
-              "rtr %s %lld: deadline %lld ping_notsent %d alive %d "
-              "alive_count %d lpni_ping_timestamp %lld\n",
-              libcfs_nid2str(rtr->lpni_nid), secs,
-              rtr->lpni_ping_deadline, rtr->lpni_ping_notsent,
-              rtr->lpni_alive, rtr->lpni_alive_count, rtr->lpni_ping_timestamp);
-
-       if (secs != 0 && !rtr->lpni_ping_notsent &&
-           now > rtr->lpni_ping_timestamp + secs) {
-               int               rc;
-               struct lnet_process_id id;
-               struct lnet_handle_md mdh;
-
-               id.nid = rtr->lpni_nid;
-               id.pid = LNET_PID_LUSTRE;
-               CDEBUG(D_NET, "Check: %s\n", libcfs_id2str(id));
-
-               rtr->lpni_ping_notsent   = 1;
-               rtr->lpni_ping_timestamp = now;
-
-               mdh = rcd->rcd_mdh;
-
-               if (rtr->lpni_ping_deadline == 0) {
-                       rtr->lpni_ping_deadline = ktime_get_seconds() +
-                                                 router_ping_timeout;
-               }
-
-               lnet_net_unlock(rtr->lpni_cpt);
-
-               rc = LNetGet(LNET_NID_ANY, mdh, id, LNET_RESERVED_PORTAL,
-                            LNET_PROTO_PING_MATCHBITS, 0);
-
-               lnet_net_lock(rtr->lpni_cpt);
-               if (rc != 0)
-                       rtr->lpni_ping_notsent = 0; /* no event pending */
-       }
-
-       lnet_peer_ni_decref_locked(rtr);
-       return;
-}
-
-int
-lnet_router_checker_start(void)
-{
-       int                     rc;
-       int                     eqsz = 0;
-       struct task_struct     *task;
-
-       LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
 
        if (check_routers_before_use &&
            dead_router_check_interval <= 0) {
@@ -1138,153 +801,49 @@ lnet_router_checker_start(void)
                return -EINVAL;
        }
 
-       sema_init(&the_lnet.ln_rc_signal, 0);
-
        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);
+               CERROR("Can't allocate EQ(0): %d\n", 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);
-               CERROR("Can't start router checker thread: %d\n", rc);
-               /* block until event callback signals exit */
-               down(&the_lnet.ln_rc_signal);
-               rc = LNetEQFree(the_lnet.ln_rc_eqh);
-               LASSERT(rc == 0);
-               the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
-               return -ENOMEM;
-       }
+       return 0;
+}
 
+void lnet_router_post_mt_start(void)
+{
        if (check_routers_before_use) {
                /* Note that a helpful side-effect of pinging all known routers
                 * at startup is that it makes them drop stale connections they
                 * may have to a previous instance of me. */
                lnet_wait_known_routerstate();
        }
-
-       return 0;
 }
 
 void
-lnet_router_checker_stop (void)
+lnet_router_cleanup(void)
 {
        int rc;
 
-       if (the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN)
-               return;
-
-       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);
-
-       /* block until event callback signals exit */
-       down(&the_lnet.ln_rc_signal);
-       LASSERT(the_lnet.ln_rc_state == LNET_RC_STATE_SHUTDOWN);
-
        rc = LNetEQFree(the_lnet.ln_rc_eqh);
        LASSERT(rc == 0);
        return;
 }
 
-static void
+void
 lnet_prune_rc_data(int wait_unlink)
 {
-       struct lnet_rc_data *rcd;
-       struct lnet_rc_data *tmp;
-       struct lnet_peer_ni *lp;
-       struct list_head head;
-       int i = 2;
-
-       if (likely(the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING &&
-                  list_empty(&the_lnet.ln_rcd_deathrow) &&
-                  list_empty(&the_lnet.ln_rcd_zombie)))
-               return;
-
-       INIT_LIST_HEAD(&head);
-
-       lnet_net_lock(LNET_LOCK_EX);
-
-       if (the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING) {
-               /* router checker is stopping, prune all */
-               list_for_each_entry(lp, &the_lnet.ln_routers,
-                                   lpni_rtr_list) {
-                       if (lp->lpni_rcd == NULL)
-                               continue;
-
-                       LASSERT(list_empty(&lp->lpni_rcd->rcd_list));
-                       list_add(&lp->lpni_rcd->rcd_list,
-                                &the_lnet.ln_rcd_deathrow);
-                       lp->lpni_rcd = NULL;
-               }
-       }
-
-       /* unlink all RCDs on deathrow list */
-       list_splice_init(&the_lnet.ln_rcd_deathrow, &head);
-
-       if (!list_empty(&head)) {
-               lnet_net_unlock(LNET_LOCK_EX);
-
-               list_for_each_entry(rcd, &head, rcd_list)
-                       LNetMDUnlink(rcd->rcd_mdh);
-
-               lnet_net_lock(LNET_LOCK_EX);
-       }
-
-       list_splice_init(&head, &the_lnet.ln_rcd_zombie);
-
-       /* release all zombie RCDs */
-       while (!list_empty(&the_lnet.ln_rcd_zombie)) {
-               list_for_each_entry_safe(rcd, tmp, &the_lnet.ln_rcd_zombie,
-                                        rcd_list) {
-                       if (LNetMDHandleIsInvalid(rcd->rcd_mdh))
-                               list_move(&rcd->rcd_list, &head);
-               }
-
-               wait_unlink = wait_unlink &&
-                             !list_empty(&the_lnet.ln_rcd_zombie);
-
-               lnet_net_unlock(LNET_LOCK_EX);
-
-               while (!list_empty(&head)) {
-                       rcd = list_entry(head.next,
-                                        struct lnet_rc_data, rcd_list);
-                       list_del_init(&rcd->rcd_list);
-                       lnet_destroy_rc_data(rcd);
-               }
-
-               if (!wait_unlink)
-                       return;
-
-               i++;
-               CDEBUG(((i & (-i)) == i) ? D_WARNING : D_NET,
-                      "Waiting for rc buffers to unlink\n");
-               set_current_state(TASK_UNINTERRUPTIBLE);
-               schedule_timeout(cfs_time_seconds(1) / 4);
-
-               lnet_net_lock(LNET_LOCK_EX);
-       }
-
-       lnet_net_unlock(LNET_LOCK_EX);
+       wait_unlink = wait_unlink;
 }
 
 /*
- * 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
+ * This function is called from the monitor thread to check if there are
+ * any active routers that need to be checked.
  */
-static inline bool
+inline bool
 lnet_router_checker_active(void)
 {
-       if (the_lnet.ln_rc_state != LNET_RC_STATE_RUNNING)
+       if (the_lnet.ln_mt_state != LNET_MT_STATE_RUNNING)
                return true;
 
        /* Router Checker thread needs to run when routing is enabled in
@@ -1292,79 +851,47 @@ lnet_router_checker_active(void)
        if (the_lnet.ln_routing)
                return true;
 
+       /* if there are routers that need to be cleaned up then do so */
+       if (!list_empty(&the_lnet.ln_rcd_deathrow) ||
+           !list_empty(&the_lnet.ln_rcd_zombie))
+               return true;
+
        return !list_empty(&the_lnet.ln_routers) &&
                (live_router_check_interval > 0 ||
                 dead_router_check_interval > 0);
 }
 
-static int
-lnet_router_checker(void *arg)
+void
+lnet_check_routers(void)
 {
-       struct lnet_peer_ni *rtr;
+       struct lnet_peer *rtr;
        struct list_head *entry;
+       __u64   version;
+       int     cpt;
 
-       cfs_block_allsigs();
-
-       while (the_lnet.ln_rc_state == LNET_RC_STATE_RUNNING) {
-               __u64   version;
-               int     cpt;
-               int     cpt2;
-
-               cpt = lnet_net_lock_current();
+       cpt = lnet_net_lock_current();
 rescan:
-               version = the_lnet.ln_routers_version;
+       version = the_lnet.ln_routers_version;
 
-               list_for_each(entry, &the_lnet.ln_routers) {
-                       rtr = list_entry(entry, struct lnet_peer_ni,
-                                        lpni_rtr_list);
-
-                       cpt2 = rtr->lpni_cpt;
-                       if (cpt != cpt2) {
-                               lnet_net_unlock(cpt);
-                               cpt = cpt2;
-                               lnet_net_lock(cpt);
-                               /* the routers list has changed */
-                               if (version != the_lnet.ln_routers_version)
-                                       goto rescan;
-                       }
+       list_for_each(entry, &the_lnet.ln_routers) {
+               rtr = list_entry(entry, struct lnet_peer,
+                                lp_rtr_list);
 
-                       lnet_ping_router_locked(rtr);
+               /* TODO use discovery to determine if router is alive */
 
-                       /* 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();
-
-               lnet_net_unlock(cpt);
-
-               lnet_prune_rc_data(0); /* don't wait for UNLINK */
-
-               /* Call schedule_timeout() here always adds 1 to load average
-                * because kernel counts # active tasks as nr_running
-                * + nr_uninterruptible. */
-               /* 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));
        }
 
-       lnet_prune_rc_data(1); /* wait for UNLINK */
+       if (the_lnet.ln_routing)
+               lnet_update_ni_status_locked();
 
-       the_lnet.ln_rc_state = LNET_RC_STATE_SHUTDOWN;
-       up(&the_lnet.ln_rc_signal);
-       /* The unlink event callback will signal final completion */
-       return 0;
+       lnet_net_unlock(cpt);
+
+       lnet_prune_rc_data(0); /* don't wait for UNLINK */
 }
 
 void
@@ -1680,6 +1207,7 @@ lnet_rtrpools_alloc(int im_a_router)
        lnet_net_lock(LNET_LOCK_EX);
        the_lnet.ln_routing = 1;
        lnet_net_unlock(LNET_LOCK_EX);
+       wake_up(&the_lnet.ln_mt_waitq);
        return 0;
 
  failed: