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LU-12678 lnet: convert lpni_refcount to a kref
[fs/lustre-release.git] / lnet / lnet / peer.c
index 5f6b3ad..678b1f4 100644 (file)
@@ -40,6 +40,7 @@
 #endif
 #include <linux/uaccess.h>
 
+#include <lnet/udsp.h>
 #include <lnet/lib-lnet.h>
 #include <uapi/linux/lnet/lnet-dlc.h>
 
@@ -168,7 +169,7 @@ lnet_peer_ni_alloc(lnet_nid_t nid)
        INIT_LIST_HEAD(&lpni->lpni_on_remote_peer_ni_list);
        INIT_LIST_HEAD(&lpni->lpni_rtr_pref_nids);
        LNetInvalidateMDHandle(&lpni->lpni_recovery_ping_mdh);
-       atomic_set(&lpni->lpni_refcount, 1);
+       kref_init(&lpni->lpni_kref);
        lpni->lpni_sel_priority = LNET_MAX_SELECTION_PRIORITY;
 
        spin_lock_init(&lpni->lpni_lock);
@@ -458,6 +459,10 @@ lnet_peer_del_locked(struct lnet_peer *peer)
 
        CDEBUG(D_NET, "peer %s\n", libcfs_nid2str(peer->lp_primary_nid));
 
+       spin_lock(&peer->lp_lock);
+       peer->lp_state |= LNET_PEER_MARK_DELETED;
+       spin_unlock(&peer->lp_lock);
+
        lpni = lnet_get_next_peer_ni_locked(peer, NULL, lpni);
        while (lpni != NULL) {
                lpni2 = lnet_get_next_peer_ni_locked(peer, NULL, lpni);
@@ -470,9 +475,41 @@ lnet_peer_del_locked(struct lnet_peer *peer)
        return rc2;
 }
 
+/*
+ * Discovering this peer is taking too long. Cancel any Ping or Push
+ * that discovery is waiting on by unlinking the relevant MDs. The
+ * lnet_discovery_event_handler() will proceed from here and complete
+ * the cleanup.
+ */
+static void lnet_peer_cancel_discovery(struct lnet_peer *lp)
+{
+       struct lnet_handle_md ping_mdh;
+       struct lnet_handle_md push_mdh;
+
+       LNetInvalidateMDHandle(&ping_mdh);
+       LNetInvalidateMDHandle(&push_mdh);
+
+       spin_lock(&lp->lp_lock);
+       if (lp->lp_state & LNET_PEER_PING_SENT) {
+               ping_mdh = lp->lp_ping_mdh;
+               LNetInvalidateMDHandle(&lp->lp_ping_mdh);
+       }
+       if (lp->lp_state & LNET_PEER_PUSH_SENT) {
+               push_mdh = lp->lp_push_mdh;
+               LNetInvalidateMDHandle(&lp->lp_push_mdh);
+       }
+       spin_unlock(&lp->lp_lock);
+
+       if (!LNetMDHandleIsInvalid(ping_mdh))
+               LNetMDUnlink(ping_mdh);
+       if (!LNetMDHandleIsInvalid(push_mdh))
+               LNetMDUnlink(push_mdh);
+}
+
 static int
 lnet_peer_del(struct lnet_peer *peer)
 {
+       lnet_peer_cancel_discovery(peer);
        lnet_net_lock(LNET_LOCK_EX);
        lnet_peer_del_locked(peer);
        lnet_net_unlock(LNET_LOCK_EX);
@@ -1058,6 +1095,12 @@ lnet_peer_ni_clr_non_mr_pref_nid(struct lnet_peer_ni *lpni)
        return rc;
 }
 
+void
+lnet_peer_ni_set_selection_priority(struct lnet_peer_ni *lpni, __u32 priority)
+{
+       lpni->lpni_sel_priority = priority;
+}
+
 /*
  * Clear the preferred NIDs from a non-multi-rail peer.
  */
@@ -1314,6 +1357,16 @@ LNetPrimaryNID(lnet_nid_t nid)
                rc = lnet_discover_peer_locked(lpni, cpt, true);
                if (rc)
                        goto out_decref;
+               /* The lpni (or lp) for this NID may have changed and our ref is
+                * the only thing keeping the old one around. Release the ref
+                * and lookup the lpni again
+                */
+               lnet_peer_ni_decref_locked(lpni);
+               lpni = lnet_find_peer_ni_locked(nid);
+               if (!lpni) {
+                       rc = -ENOENT;
+                       goto out_unlock;
+               }
                lp = lpni->lpni_peer_net->lpn_peer;
 
                /* Only try once if discovery is disabled */
@@ -1360,6 +1413,8 @@ lnet_peer_attach_peer_ni(struct lnet_peer *lp,
                                unsigned flags)
 {
        struct lnet_peer_table *ptable;
+       bool new_lpn = false;
+       int rc;
 
        /* Install the new peer_ni */
        lnet_net_lock(LNET_LOCK_EX);
@@ -1390,6 +1445,7 @@ lnet_peer_attach_peer_ni(struct lnet_peer *lp,
 
        /* Add peer_net to peer */
        if (!lpn->lpn_peer) {
+               new_lpn = true;
                lpn->lpn_peer = lp;
                list_add_tail(&lpn->lpn_peer_nets, &lp->lp_peer_nets);
                lnet_peer_addref_locked(lp);
@@ -1419,6 +1475,18 @@ lnet_peer_attach_peer_ni(struct lnet_peer *lp,
 
        lp->lp_nnis++;
 
+       /* apply UDSPs */
+       if (new_lpn) {
+               rc = lnet_udsp_apply_policies_on_lpn(lpn);
+               if (rc)
+                       CERROR("Failed to apply UDSPs on lpn %s\n",
+                              libcfs_net2str(lpn->lpn_net_id));
+       }
+       rc = lnet_udsp_apply_policies_on_lpni(lpni);
+       if (rc)
+               CERROR("Failed to apply UDSPs on lpni %s\n",
+                      libcfs_nid2str(lpni->lpni_nid));
+
        CDEBUG(D_NET, "peer %s NID %s flags %#x\n",
               libcfs_nid2str(lp->lp_primary_nid),
               libcfs_nid2str(lpni->lpni_nid), flags);
@@ -1805,14 +1873,16 @@ lnet_del_peer_ni(lnet_nid_t prim_nid, lnet_nid_t nid)
 }
 
 void
-lnet_destroy_peer_ni_locked(struct lnet_peer_ni *lpni)
+lnet_destroy_peer_ni_locked(struct kref *ref)
 {
+       struct lnet_peer_ni *lpni = container_of(ref, struct lnet_peer_ni,
+                                                lpni_kref);
        struct lnet_peer_table *ptable;
        struct lnet_peer_net *lpn;
 
        CDEBUG(D_NET, "%p nid %s\n", lpni, libcfs_nid2str(lpni->lpni_nid));
 
-       LASSERT(atomic_read(&lpni->lpni_refcount) == 0);
+       LASSERT(kref_read(&lpni->lpni_kref) == 0);
        LASSERT(list_empty(&lpni->lpni_txq));
        LASSERT(lpni->lpni_txqnob == 0);
        LASSERT(list_empty(&lpni->lpni_peer_nis));
@@ -2005,6 +2075,26 @@ __must_hold(&lp->lp_lock)
        return rc;
 }
 
+/* Add the message to the peer's lp_dc_pendq and queue the peer for discovery */
+void
+lnet_peer_queue_message(struct lnet_peer *lp, struct lnet_msg *msg)
+{
+       /* The discovery thread holds net_lock/EX and lp_lock when it splices
+        * the lp_dc_pendq onto a local list for resending. Thus, we do the same
+        * when adding to the list and queuing the peer to ensure that we do not
+        * strand any messages on the lp_dc_pendq. This scheme ensures the
+        * message will be resent even if the peer is already being discovered.
+        * Therefore we needn't check the return value of
+        * lnet_peer_queue_for_discovery(lp).
+        */
+       lnet_net_lock(LNET_LOCK_EX);
+       spin_lock(&lp->lp_lock);
+       list_add_tail(&msg->msg_list, &lp->lp_dc_pendq);
+       spin_unlock(&lp->lp_lock);
+       lnet_peer_queue_for_discovery(lp);
+       lnet_net_unlock(LNET_LOCK_EX);
+}
+
 /*
  * Queue a peer for the attention of the discovery thread.  Call with
  * lnet_net_lock/EX held. Returns 0 if the peer was queued, and
@@ -2927,6 +3017,72 @@ static bool lnet_is_nid_in_ping_info(lnet_nid_t nid, struct lnet_ping_info *pinf
        return false;
 }
 
+/* Delete a peer that has been marked for deletion. NB: when this peer was added
+ * to the discovery queue a reference was taken that will prevent the peer from
+ * actually being freed by this function. After this function exits the
+ * discovery thread should call lnet_peer_discovery_complete() which will
+ * drop that reference as well as wake any waiters that may also be holding a
+ * ref on the peer
+ */
+static int lnet_peer_deletion(struct lnet_peer *lp)
+__must_hold(&lp->lp_lock)
+{
+       struct list_head rlist;
+       struct lnet_route *route, *tmp;
+       int sensitivity = lp->lp_health_sensitivity;
+
+       INIT_LIST_HEAD(&rlist);
+
+       lp->lp_state &= ~(LNET_PEER_DISCOVERING | LNET_PEER_FORCE_PING |
+                         LNET_PEER_FORCE_PUSH);
+       CDEBUG(D_NET, "peer %s(%p) state %#x\n",
+              libcfs_nid2str(lp->lp_primary_nid), lp, lp->lp_state);
+
+       /* no-op if lnet_peer_del() has already been called on this peer */
+       if (lp->lp_state & LNET_PEER_MARK_DELETED)
+               return 0;
+
+       if (the_lnet.ln_dc_state != LNET_DC_STATE_RUNNING)
+               return -ESHUTDOWN;
+
+       spin_unlock(&lp->lp_lock);
+
+       mutex_lock(&the_lnet.ln_api_mutex);
+
+       lnet_net_lock(LNET_LOCK_EX);
+       /* remove the peer from the discovery work
+        * queue if it's on there in preparation
+        * of deleting it.
+        */
+       if (!list_empty(&lp->lp_dc_list))
+               list_del(&lp->lp_dc_list);
+       list_for_each_entry_safe(route, tmp,
+                                &lp->lp_routes,
+                                lr_gwlist)
+               lnet_move_route(route, NULL, &rlist);
+       lnet_net_unlock(LNET_LOCK_EX);
+
+       /* lnet_peer_del() deletes all the peer NIs owned by this peer */
+       lnet_peer_del(lp);
+
+       list_for_each_entry_safe(route, tmp,
+                                &rlist, lr_list) {
+               /* re-add these routes */
+               lnet_add_route(route->lr_net,
+                              route->lr_hops,
+                              route->lr_nid,
+                              route->lr_priority,
+                              sensitivity);
+               LIBCFS_FREE(route, sizeof(*route));
+       }
+
+       mutex_unlock(&the_lnet.ln_api_mutex);
+
+       spin_lock(&lp->lp_lock);
+
+       return 0;
+}
+
 /*
  * Update a peer using the data received.
  */
@@ -3008,7 +3164,7 @@ __must_hold(&lp->lp_lock)
                rc = lnet_peer_merge_data(lp, pbuf);
        } else {
                lpni = lnet_find_peer_ni_locked(nid);
-               if (!lpni) {
+               if (!lpni || lp == lpni->lpni_peer_net->lpn_peer) {
                        rc = lnet_peer_set_primary_nid(lp, nid, flags);
                        if (rc) {
                                CERROR("Primary NID error %s versus %s: %d\n",
@@ -3017,6 +3173,8 @@ __must_hold(&lp->lp_lock)
                        } else {
                                rc = lnet_peer_merge_data(lp, pbuf);
                        }
+                       if (lpni)
+                               lnet_peer_ni_decref_locked(lpni);
                } else {
                        struct lnet_peer *new_lp;
                        new_lp = lpni->lpni_peer_net->lpn_peer;
@@ -3025,10 +3183,22 @@ __must_hold(&lp->lp_lock)
                         * should have discovery/MR enabled as well, since
                         * it's the same peer, which we're about to merge
                         */
+                       spin_lock(&lp->lp_lock);
+                       spin_lock(&new_lp->lp_lock);
                        if (!(lp->lp_state & LNET_PEER_NO_DISCOVERY))
                                new_lp->lp_state &= ~LNET_PEER_NO_DISCOVERY;
                        if (lp->lp_state & LNET_PEER_MULTI_RAIL)
                                new_lp->lp_state |= LNET_PEER_MULTI_RAIL;
+                       /* If we're processing a ping reply then we may be
+                        * about to send a push to the peer that we ping'd.
+                        * Since the ping reply that we're processing was
+                        * received by lp, we need to set the discovery source
+                        * NID for new_lp to the NID stored in lp.
+                        */
+                       if (lp->lp_disc_src_nid != LNET_NID_ANY)
+                               new_lp->lp_disc_src_nid = lp->lp_disc_src_nid;
+                       spin_unlock(&new_lp->lp_lock);
+                       spin_unlock(&lp->lp_lock);
 
                        rc = lnet_peer_set_primary_data(new_lp, pbuf);
                        lnet_consolidate_routes_locked(lp, new_lp);
@@ -3318,37 +3488,6 @@ static void lnet_peer_discovery_error(struct lnet_peer *lp, int error)
 }
 
 /*
- * Discovering this peer is taking too long. Cancel any Ping or Push
- * that discovery is waiting on by unlinking the relevant MDs. The
- * lnet_discovery_event_handler() will proceed from here and complete
- * the cleanup.
- */
-static void lnet_peer_cancel_discovery(struct lnet_peer *lp)
-{
-       struct lnet_handle_md ping_mdh;
-       struct lnet_handle_md push_mdh;
-
-       LNetInvalidateMDHandle(&ping_mdh);
-       LNetInvalidateMDHandle(&push_mdh);
-
-       spin_lock(&lp->lp_lock);
-       if (lp->lp_state & LNET_PEER_PING_SENT) {
-               ping_mdh = lp->lp_ping_mdh;
-               LNetInvalidateMDHandle(&lp->lp_ping_mdh);
-       }
-       if (lp->lp_state & LNET_PEER_PUSH_SENT) {
-               push_mdh = lp->lp_push_mdh;
-               LNetInvalidateMDHandle(&lp->lp_push_mdh);
-       }
-       spin_unlock(&lp->lp_lock);
-
-       if (!LNetMDHandleIsInvalid(ping_mdh))
-               LNetMDUnlink(ping_mdh);
-       if (!LNetMDHandleIsInvalid(push_mdh))
-               LNetMDUnlink(push_mdh);
-}
-
-/*
  * Wait for work to be queued or some other change that must be
  * attended to. Returns non-zero if the discovery thread should shut
  * down.
@@ -3504,7 +3643,10 @@ static int lnet_peer_discovery(void *arg)
                        CDEBUG(D_NET, "peer %s(%p) state %#x\n",
                                libcfs_nid2str(lp->lp_primary_nid), lp,
                                lp->lp_state);
-                       if (lp->lp_state & LNET_PEER_DATA_PRESENT)
+                       if (lp->lp_state & (LNET_PEER_MARK_DELETION |
+                                           LNET_PEER_MARK_DELETED))
+                               rc = lnet_peer_deletion(lp);
+                       else if (lp->lp_state & LNET_PEER_DATA_PRESENT)
                                rc = lnet_peer_data_present(lp);
                        else if (lp->lp_state & LNET_PEER_PING_FAILED)
                                rc = lnet_peer_ping_failed(lp);
@@ -3537,49 +3679,6 @@ static int lnet_peer_discovery(void *arg)
                        if (the_lnet.ln_dc_state == LNET_DC_STATE_STOPPING)
                                break;
 
-                       if (lp->lp_state & LNET_PEER_MARK_DELETION) {
-                               struct list_head rlist;
-                               struct lnet_route *route, *tmp;
-                               int sensitivity = lp->lp_health_sensitivity;
-
-                               INIT_LIST_HEAD(&rlist);
-
-                               /*
-                                * remove the peer from the discovery work
-                                * queue if it's on there in preparation
-                                * of deleting it.
-                                */
-                               if (!list_empty(&lp->lp_dc_list))
-                                       list_del(&lp->lp_dc_list);
-
-                               lnet_net_unlock(LNET_LOCK_EX);
-
-                               mutex_lock(&the_lnet.ln_api_mutex);
-
-                               lnet_net_lock(LNET_LOCK_EX);
-                               list_for_each_entry_safe(route, tmp,
-                                                        &lp->lp_routes,
-                                                        lr_gwlist)
-                                       lnet_move_route(route, NULL, &rlist);
-                               lnet_net_unlock(LNET_LOCK_EX);
-
-                               /* delete the peer */
-                               lnet_peer_del(lp);
-
-                               list_for_each_entry_safe(route, tmp,
-                                                        &rlist, lr_list) {
-                                       /* re-add these routes */
-                                       lnet_add_route(route->lr_net,
-                                                      route->lr_hops,
-                                                      route->lr_nid,
-                                                      route->lr_priority,
-                                                      sensitivity);
-                                       LIBCFS_FREE(route, sizeof(*route));
-                               }
-                               mutex_unlock(&the_lnet.ln_api_mutex);
-
-                               lnet_net_lock(LNET_LOCK_EX);
-                       }
                }
 
                lnet_net_unlock(LNET_LOCK_EX);
@@ -3706,7 +3805,7 @@ lnet_debug_peer(lnet_nid_t nid)
                aliveness = (lnet_is_peer_ni_alive(lp)) ? "up" : "down";
 
        CDEBUG(D_WARNING, "%-24s %4d %5s %5d %5d %5d %5d %5d %ld\n",
-              libcfs_nid2str(lp->lpni_nid), atomic_read(&lp->lpni_refcount),
+              libcfs_nid2str(lp->lpni_nid), kref_read(&lp->lpni_kref),
               aliveness, lp->lpni_net->net_tunables.lct_peer_tx_credits,
               lp->lpni_rtrcredits, lp->lpni_minrtrcredits,
               lp->lpni_txcredits, lp->lpni_mintxcredits, lp->lpni_txqnob);
@@ -3762,7 +3861,7 @@ int lnet_get_peer_ni_info(__u32 peer_index, __u64 *nid,
                                         lnet_is_peer_ni_alive(lp) ? "up" : "down");
 
                        *nid = lp->lpni_nid;
-                       *refcount = atomic_read(&lp->lpni_refcount);
+                       *refcount = kref_read(&lp->lpni_kref);
                        *ni_peer_tx_credits =
                                lp->lpni_net->net_tunables.lct_peer_tx_credits;
                        *peer_tx_credits = lp->lpni_txcredits;
@@ -3848,7 +3947,7 @@ int lnet_get_peer_info(struct lnet_ioctl_peer_cfg *cfg, void __user *bulk)
                        snprintf(lpni_info->cr_aliveness, LNET_MAX_STR_LEN,
                                lnet_is_peer_ni_alive(lpni) ? "up" : "down");
 
-               lpni_info->cr_refcount = atomic_read(&lpni->lpni_refcount);
+               lpni_info->cr_refcount = kref_read(&lpni->lpni_kref);
                lpni_info->cr_ni_peer_tx_credits = (lpni->lpni_net != NULL) ?
                        lpni->lpni_net->net_tunables.lct_peer_tx_credits : 0;
                lpni_info->cr_peer_tx_credits = lpni->lpni_txcredits;
@@ -3904,21 +4003,54 @@ out:
        return rc;
 }
 
+/* must hold net_lock/0 */
 void
-lnet_peer_ni_add_to_recoveryq_locked(struct lnet_peer_ni *lpni)
+lnet_peer_ni_add_to_recoveryq_locked(struct lnet_peer_ni *lpni,
+                                    struct list_head *recovery_queue,
+                                    time64_t now)
 {
        /* the mt could've shutdown and cleaned up the queues */
        if (the_lnet.ln_mt_state != LNET_MT_STATE_RUNNING)
                return;
 
-       if (list_empty(&lpni->lpni_recovery) &&
-           atomic_read(&lpni->lpni_healthv) < LNET_MAX_HEALTH_VALUE) {
-               CDEBUG(D_NET, "lpni %s added to recovery queue. Health = %d\n",
-                       libcfs_nid2str(lpni->lpni_nid),
-                       atomic_read(&lpni->lpni_healthv));
-               list_add_tail(&lpni->lpni_recovery, &the_lnet.ln_mt_peerNIRecovq);
-               lnet_peer_ni_addref_locked(lpni);
+       if (!list_empty(&lpni->lpni_recovery))
+               return;
+
+       if (atomic_read(&lpni->lpni_healthv) == LNET_MAX_HEALTH_VALUE)
+               return;
+
+       if (!lpni->lpni_last_alive) {
+               CDEBUG(D_NET,
+                      "lpni %s(%p) not eligible for recovery last alive %lld\n",
+                      libcfs_nid2str(lpni->lpni_nid), lpni,
+                      lpni->lpni_last_alive);
+               return;
        }
+
+       if (now > lpni->lpni_last_alive + lnet_recovery_limit) {
+               CDEBUG(D_NET, "lpni %s aged out last alive %lld\n",
+                      libcfs_nid2str(lpni->lpni_nid),
+                      lpni->lpni_last_alive);
+               /* Reset the ping count so that if this peer NI is added back to
+                * the recovery queue we will send the first ping right away.
+                */
+               lpni->lpni_ping_count = 0;
+               return;
+       }
+
+       /* This peer NI is going on the recovery queue, so take a ref on it */
+       lnet_peer_ni_addref_locked(lpni);
+
+       lnet_peer_ni_set_next_ping(lpni, now);
+
+       CDEBUG(D_NET, "%s added to recovery queue. ping count: %u next ping: %lld last alive: %lld health: %d\n",
+              libcfs_nid2str(lpni->lpni_nid),
+              lpni->lpni_ping_count,
+              lpni->lpni_next_ping,
+              lpni->lpni_last_alive,
+              atomic_read(&lpni->lpni_healthv));
+
+       list_add_tail(&lpni->lpni_recovery, recovery_queue);
 }
 
 /* Call with the ln_api_mutex held */
@@ -3931,10 +4063,13 @@ lnet_peer_ni_set_healthv(lnet_nid_t nid, int value, bool all)
        struct lnet_peer_ni *lpni;
        int lncpt;
        int cpt;
+       time64_t now;
 
        if (the_lnet.ln_state != LNET_STATE_RUNNING)
                return;
 
+       now = ktime_get_seconds();
+
        if (!all) {
                lnet_net_lock(LNET_LOCK_EX);
                lpni = lnet_find_peer_ni_locked(nid);
@@ -3943,7 +4078,8 @@ lnet_peer_ni_set_healthv(lnet_nid_t nid, int value, bool all)
                        return;
                }
                atomic_set(&lpni->lpni_healthv, value);
-               lnet_peer_ni_add_to_recoveryq_locked(lpni);
+               lnet_peer_ni_add_to_recoveryq_locked(lpni,
+                                            &the_lnet.ln_mt_peerNIRecovq, now);
                lnet_peer_ni_decref_locked(lpni);
                lnet_net_unlock(LNET_LOCK_EX);
                return;
@@ -3952,8 +4088,8 @@ lnet_peer_ni_set_healthv(lnet_nid_t nid, int value, bool all)
        lncpt = cfs_percpt_number(the_lnet.ln_peer_tables);
 
        /*
-        * Walk all the peers and reset the healhv for each one to the
-        * maximum value.
+        * Walk all the peers and reset the health value for each one to the
+        * specified value.
         */
        lnet_net_lock(LNET_LOCK_EX);
        for (cpt = 0; cpt < lncpt; cpt++) {
@@ -3963,7 +4099,8 @@ lnet_peer_ni_set_healthv(lnet_nid_t nid, int value, bool all)
                                list_for_each_entry(lpni, &lpn->lpn_peer_nis,
                                                    lpni_peer_nis) {
                                        atomic_set(&lpni->lpni_healthv, value);
-                                       lnet_peer_ni_add_to_recoveryq_locked(lpni);
+                                       lnet_peer_ni_add_to_recoveryq_locked(lpni,
+                                            &the_lnet.ln_mt_peerNIRecovq, now);
                                }
                        }
                }