// SPDX-License-Identifier: GPL-2.0
/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.gnu.org/licenses/gpl-2.0.html
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2015, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */

#define DEBUG_SUBSYSTEM S_LNET
#include <linux/log2.h>
#include <linux/ktime.h>

#include <linux/lnet/lib-lnet.h>
#include <uapi/linux/lnet/lnet-dlc.h>

#define D_LNI D_CONSOLE

struct lnet the_lnet;           /* THE state of the network */
EXPORT_SYMBOL(the_lnet);

static char *ip2nets = "";
module_param(ip2nets, charp, 0444);
MODULE_PARM_DESC(ip2nets, "LNET network <- IP table");

static char *networks = "";
module_param(networks, charp, 0444);
MODULE_PARM_DESC(networks, "local networks");

static char *routes = "";
module_param(routes, charp, 0444);
MODULE_PARM_DESC(routes, "routes to non-local networks");

static int rnet_htable_size = LNET_REMOTE_NETS_HASH_DEFAULT;
module_param(rnet_htable_size, int, 0444);
MODULE_PARM_DESC(rnet_htable_size, "size of remote network hash table");

static int lnet_ping(struct lnet_process_id id, int timeout_ms,
                     struct lnet_process_id __user *ids, int n_ids);

static char *
lnet_get_routes(void)
{
        return routes;
}

static char *
lnet_get_networks(void)
{
        char *nets;
        int rc;

        if (*networks && *ip2nets) {
                LCONSOLE_ERROR_MSG(0x101, "Please specify EITHER 'networks' or 'ip2nets' but not both at once\n");
                return NULL;
        }

        if (*ip2nets) {
                rc = lnet_parse_ip2nets(&nets, ip2nets);
                return !rc ? nets : NULL;
        }

        if (*networks)
                return networks;

        return "tcp";
}

static void
lnet_init_locks(void)
{
        spin_lock_init(&the_lnet.ln_eq_wait_lock);
        init_waitqueue_head(&the_lnet.ln_eq_waitq);
        init_waitqueue_head(&the_lnet.ln_rc_waitq);
        mutex_init(&the_lnet.ln_lnd_mutex);
        mutex_init(&the_lnet.ln_api_mutex);
}

static int
lnet_create_remote_nets_table(void)
{
        int i;
        struct list_head *hash;

        LASSERT(!the_lnet.ln_remote_nets_hash);
        LASSERT(the_lnet.ln_remote_nets_hbits > 0);
        hash = kvmalloc_array(LNET_REMOTE_NETS_HASH_SIZE, sizeof(*hash),
                              GFP_KERNEL);
        if (!hash) {
                CERROR("Failed to create remote nets hash table\n");
                return -ENOMEM;
        }

        for (i = 0; i < LNET_REMOTE_NETS_HASH_SIZE; i++)
                INIT_LIST_HEAD(&hash[i]);
        the_lnet.ln_remote_nets_hash = hash;
        return 0;
}

static void
lnet_destroy_remote_nets_table(void)
{
        int i;

        if (!the_lnet.ln_remote_nets_hash)
                return;

        for (i = 0; i < LNET_REMOTE_NETS_HASH_SIZE; i++)
                LASSERT(list_empty(&the_lnet.ln_remote_nets_hash[i]));

        kvfree(the_lnet.ln_remote_nets_hash);
        the_lnet.ln_remote_nets_hash = NULL;
}

static void
lnet_destroy_locks(void)
{
        if (the_lnet.ln_res_lock) {
                cfs_percpt_lock_free(the_lnet.ln_res_lock);
                the_lnet.ln_res_lock = NULL;
        }

        if (the_lnet.ln_net_lock) {
                cfs_percpt_lock_free(the_lnet.ln_net_lock);
                the_lnet.ln_net_lock = NULL;
        }
}

static int
lnet_create_locks(void)
{
        lnet_init_locks();

        the_lnet.ln_res_lock = cfs_percpt_lock_alloc(lnet_cpt_table());
        if (!the_lnet.ln_res_lock)
                goto failed;

        the_lnet.ln_net_lock = cfs_percpt_lock_alloc(lnet_cpt_table());
        if (!the_lnet.ln_net_lock)
                goto failed;

        return 0;

 failed:
        lnet_destroy_locks();
        return -ENOMEM;
}

static void lnet_assert_wire_constants(void)
{
        /*
         * Wire protocol assertions generated by 'wirecheck'
         * running on Linux robert.bartonsoftware.com 2.6.8-1.521
         * #1 Mon Aug 16 09:01:18 EDT 2004 i686 athlon i386 GNU/Linux
         * with gcc version 3.3.3 20040412 (Red Hat Linux 3.3.3-7)
         */

        /* Constants... */
        BUILD_BUG_ON(LNET_PROTO_TCP_MAGIC != 0xeebc0ded);
        BUILD_BUG_ON(LNET_PROTO_TCP_VERSION_MAJOR != 1);
        BUILD_BUG_ON(LNET_PROTO_TCP_VERSION_MINOR != 0);
        BUILD_BUG_ON(LNET_MSG_ACK != 0);
        BUILD_BUG_ON(LNET_MSG_PUT != 1);
        BUILD_BUG_ON(LNET_MSG_GET != 2);
        BUILD_BUG_ON(LNET_MSG_REPLY != 3);
        BUILD_BUG_ON(LNET_MSG_HELLO != 4);

        /* Checks for struct ptl_handle_wire_t */
        BUILD_BUG_ON((int)sizeof(struct lnet_handle_wire) != 16);
        BUILD_BUG_ON((int)offsetof(struct lnet_handle_wire, wh_interface_cookie) != 0);
        BUILD_BUG_ON((int)sizeof(((struct lnet_handle_wire *)0)->wh_interface_cookie) != 8);
        BUILD_BUG_ON((int)offsetof(struct lnet_handle_wire, wh_object_cookie) != 8);
        BUILD_BUG_ON((int)sizeof(((struct lnet_handle_wire *)0)->wh_object_cookie) != 8);

        /* Checks for struct struct lnet_magicversion */
        BUILD_BUG_ON((int)sizeof(struct lnet_magicversion) != 8);
        BUILD_BUG_ON((int)offsetof(struct lnet_magicversion, magic) != 0);
        BUILD_BUG_ON((int)sizeof(((struct lnet_magicversion *)0)->magic) != 4);
        BUILD_BUG_ON((int)offsetof(struct lnet_magicversion, version_major) != 4);
        BUILD_BUG_ON((int)sizeof(((struct lnet_magicversion *)0)->version_major) != 2);
        BUILD_BUG_ON((int)offsetof(struct lnet_magicversion, version_minor) != 6);
        BUILD_BUG_ON((int)sizeof(((struct lnet_magicversion *)0)->version_minor) != 2);

        /* Checks for struct struct lnet_hdr */
        BUILD_BUG_ON((int)sizeof(struct lnet_hdr) != 72);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, dest_nid) != 0);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->dest_nid) != 8);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, src_nid) != 8);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->src_nid) != 8);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, dest_pid) != 16);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->dest_pid) != 4);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, src_pid) != 20);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->src_pid) != 4);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, type) != 24);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->type) != 4);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, payload_length) != 28);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->payload_length) != 4);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg) != 32);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg) != 40);

        /* Ack */
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.ack.dst_wmd) != 32);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.ack.dst_wmd) != 16);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.ack.match_bits) != 48);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.ack.match_bits) != 8);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.ack.mlength) != 56);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.ack.mlength) != 4);

        /* Put */
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.put.ack_wmd) != 32);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.put.ack_wmd) != 16);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.put.match_bits) != 48);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.put.match_bits) != 8);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.put.hdr_data) != 56);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.put.hdr_data) != 8);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.put.ptl_index) != 64);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.put.ptl_index) != 4);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.put.offset) != 68);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.put.offset) != 4);

        /* Get */
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.get.return_wmd) != 32);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.get.return_wmd) != 16);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.get.match_bits) != 48);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.get.match_bits) != 8);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.get.ptl_index) != 56);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.get.ptl_index) != 4);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.get.src_offset) != 60);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.get.src_offset) != 4);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.get.sink_length) != 64);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.get.sink_length) != 4);

        /* Reply */
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.reply.dst_wmd) != 32);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.reply.dst_wmd) != 16);

        /* Hello */
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.hello.incarnation) != 32);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.hello.incarnation) != 8);
        BUILD_BUG_ON((int)offsetof(struct lnet_hdr, msg.hello.type) != 40);
        BUILD_BUG_ON((int)sizeof(((struct lnet_hdr *)0)->msg.hello.type) != 4);
}

static struct lnet_lnd *
lnet_find_lnd_by_type(__u32 type)
{
        struct lnet_lnd *lnd;
        struct list_head *tmp;

        /* holding lnd mutex */
        list_for_each(tmp, &the_lnet.ln_lnds) {
                lnd = list_entry(tmp, struct lnet_lnd, lnd_list);

                if (lnd->lnd_type == type)
                        return lnd;
        }

        return NULL;
}

void
lnet_register_lnd(struct lnet_lnd *lnd)
{
        mutex_lock(&the_lnet.ln_lnd_mutex);

        LASSERT(libcfs_isknown_lnd(lnd->lnd_type));
        LASSERT(!lnet_find_lnd_by_type(lnd->lnd_type));

        list_add_tail(&lnd->lnd_list, &the_lnet.ln_lnds);
        lnd->lnd_refcount = 0;

        CDEBUG(D_NET, "%s LND registered\n", libcfs_lnd2str(lnd->lnd_type));

        mutex_unlock(&the_lnet.ln_lnd_mutex);
}
EXPORT_SYMBOL(lnet_register_lnd);

void
lnet_unregister_lnd(struct lnet_lnd *lnd)
{
        mutex_lock(&the_lnet.ln_lnd_mutex);

        LASSERT(lnet_find_lnd_by_type(lnd->lnd_type) == lnd);
        LASSERT(!lnd->lnd_refcount);

        list_del(&lnd->lnd_list);
        CDEBUG(D_NET, "%s LND unregistered\n", libcfs_lnd2str(lnd->lnd_type));

        mutex_unlock(&the_lnet.ln_lnd_mutex);
}
EXPORT_SYMBOL(lnet_unregister_lnd);

void
lnet_counters_get(struct lnet_counters *counters)
{
        struct lnet_counters *ctr;
        int i;

        memset(counters, 0, sizeof(*counters));

        lnet_net_lock(LNET_LOCK_EX);

        cfs_percpt_for_each(ctr, i, the_lnet.ln_counters) {
                counters->msgs_max     += ctr->msgs_max;
                counters->msgs_alloc   += ctr->msgs_alloc;
                counters->errors       += ctr->errors;
                counters->send_count   += ctr->send_count;
                counters->recv_count   += ctr->recv_count;
                counters->route_count  += ctr->route_count;
                counters->drop_count   += ctr->drop_count;
                counters->send_length  += ctr->send_length;
                counters->recv_length  += ctr->recv_length;
                counters->route_length += ctr->route_length;
                counters->drop_length  += ctr->drop_length;
        }
        lnet_net_unlock(LNET_LOCK_EX);
}
EXPORT_SYMBOL(lnet_counters_get);

void
lnet_counters_reset(void)
{
        struct lnet_counters *counters;
        int i;

        lnet_net_lock(LNET_LOCK_EX);

        cfs_percpt_for_each(counters, i, the_lnet.ln_counters)
                memset(counters, 0, sizeof(struct lnet_counters));

        lnet_net_unlock(LNET_LOCK_EX);
}

static char *
lnet_res_type2str(int type)
{
        switch (type) {
        default:
                LBUG();
        case LNET_COOKIE_TYPE_MD:
                return "MD";
        case LNET_COOKIE_TYPE_ME:
                return "ME";
        case LNET_COOKIE_TYPE_EQ:
                return "EQ";
        }
}

static void
lnet_res_container_cleanup(struct lnet_res_container *rec)
{
        int count = 0;

        if (!rec->rec_type) /* not set yet, it's uninitialized */
                return;

        while (!list_empty(&rec->rec_active)) {
                struct list_head *e = rec->rec_active.next;

                list_del_init(e);
                if (rec->rec_type == LNET_COOKIE_TYPE_EQ) {
                        kfree(list_entry(e, struct lnet_eq, eq_list));

                } else if (rec->rec_type == LNET_COOKIE_TYPE_MD) {
                        kfree(list_entry(e, struct lnet_libmd, md_list));

                } else { /* NB: Active MEs should be attached on portals */
                        LBUG();
                }
                count++;
        }

        if (count > 0) {
                /*
                 * Found alive MD/ME/EQ, user really should unlink/free
                 * all of them before finalize LNet, but if someone didn't,
                 * we have to recycle garbage for him
                 */
                CERROR("%d active elements on exit of %s container\n",
                       count, lnet_res_type2str(rec->rec_type));
        }

        kfree(rec->rec_lh_hash);
        rec->rec_lh_hash = NULL;

        rec->rec_type = 0; /* mark it as finalized */
}

static int
lnet_res_container_setup(struct lnet_res_container *rec, int cpt, int type)
{
        int rc = 0;
        int i;

        LASSERT(!rec->rec_type);

        rec->rec_type = type;
        INIT_LIST_HEAD(&rec->rec_active);
        rec->rec_lh_cookie = (cpt << LNET_COOKIE_TYPE_BITS) | type;

        /* Arbitrary choice of hash table size */
        rec->rec_lh_hash = kvmalloc_cpt(LNET_LH_HASH_SIZE * sizeof(rec->rec_lh_hash[0]),
                                        GFP_KERNEL, cpt);
        if (!rec->rec_lh_hash) {
                rc = -ENOMEM;
                goto out;
        }

        for (i = 0; i < LNET_LH_HASH_SIZE; i++)
                INIT_LIST_HEAD(&rec->rec_lh_hash[i]);

        return 0;

out:
        CERROR("Failed to setup %s resource container\n",
               lnet_res_type2str(type));
        lnet_res_container_cleanup(rec);
        return rc;
}

static void
lnet_res_containers_destroy(struct lnet_res_container **recs)
{
        struct lnet_res_container *rec;
        int i;

        cfs_percpt_for_each(rec, i, recs)
                lnet_res_container_cleanup(rec);

        cfs_percpt_free(recs);
}

static struct lnet_res_container **
lnet_res_containers_create(int type)
{
        struct lnet_res_container **recs;
        struct lnet_res_container *rec;
        int rc;
        int i;

        recs = cfs_percpt_alloc(lnet_cpt_table(), sizeof(*rec));
        if (!recs) {
                CERROR("Failed to allocate %s resource containers\n",
                       lnet_res_type2str(type));
                return NULL;
        }

        cfs_percpt_for_each(rec, i, recs) {
                rc = lnet_res_container_setup(rec, i, type);
                if (rc) {
                        lnet_res_containers_destroy(recs);
                        return NULL;
                }
        }

        return recs;
}

struct lnet_libhandle *
lnet_res_lh_lookup(struct lnet_res_container *rec, __u64 cookie)
{
        /* ALWAYS called with lnet_res_lock held */
        struct list_head *head;
        struct lnet_libhandle *lh;
        unsigned int hash;

        if ((cookie & LNET_COOKIE_MASK) != rec->rec_type)
                return NULL;

        hash = cookie >> (LNET_COOKIE_TYPE_BITS + LNET_CPT_BITS);
        head = &rec->rec_lh_hash[hash & LNET_LH_HASH_MASK];

        list_for_each_entry(lh, head, lh_hash_chain) {
                if (lh->lh_cookie == cookie)
                        return lh;
        }

        return NULL;
}

void
lnet_res_lh_initialize(struct lnet_res_container *rec,
                       struct lnet_libhandle *lh)
{
        /* ALWAYS called with lnet_res_lock held */
        unsigned int ibits = LNET_COOKIE_TYPE_BITS + LNET_CPT_BITS;
        unsigned int hash;

        lh->lh_cookie = rec->rec_lh_cookie;
        rec->rec_lh_cookie += 1 << ibits;

        hash = (lh->lh_cookie >> ibits) & LNET_LH_HASH_MASK;

        list_add(&lh->lh_hash_chain, &rec->rec_lh_hash[hash]);
}

static int lnet_unprepare(void);

static int
lnet_prepare(lnet_pid_t requested_pid)
{
        /* Prepare to bring up the network */
        struct lnet_res_container **recs;
        int rc = 0;

        if (requested_pid == LNET_PID_ANY) {
                /* Don't instantiate LNET just for me */
                return -ENETDOWN;
        }

        LASSERT(!the_lnet.ln_refcount);

        the_lnet.ln_routing = 0;

        LASSERT(!(requested_pid & LNET_PID_USERFLAG));
        the_lnet.ln_pid = requested_pid;

        INIT_LIST_HEAD(&the_lnet.ln_test_peers);
        INIT_LIST_HEAD(&the_lnet.ln_nis);
        INIT_LIST_HEAD(&the_lnet.ln_nis_cpt);
        INIT_LIST_HEAD(&the_lnet.ln_nis_zombie);
        INIT_LIST_HEAD(&the_lnet.ln_routers);
        INIT_LIST_HEAD(&the_lnet.ln_drop_rules);
        INIT_LIST_HEAD(&the_lnet.ln_delay_rules);

        rc = lnet_create_remote_nets_table();
        if (rc)
                goto failed;
        /*
         * NB the interface cookie in wire handles guards against delayed
         * replies and ACKs appearing valid after reboot.
         */
        the_lnet.ln_interface_cookie = ktime_get_ns();

        the_lnet.ln_counters = cfs_percpt_alloc(lnet_cpt_table(),
                                                sizeof(struct lnet_counters));
        if (!the_lnet.ln_counters) {
                CERROR("Failed to allocate counters for LNet\n");
                rc = -ENOMEM;
                goto failed;
        }

        rc = lnet_peer_tables_create();
        if (rc)
                goto failed;

        rc = lnet_msg_containers_create();
        if (rc)
                goto failed;

        rc = lnet_res_container_setup(&the_lnet.ln_eq_container, 0,
                                      LNET_COOKIE_TYPE_EQ);
        if (rc)
                goto failed;

        recs = lnet_res_containers_create(LNET_COOKIE_TYPE_ME);
        if (!recs) {
                rc = -ENOMEM;
                goto failed;
        }

        the_lnet.ln_me_containers = recs;

        recs = lnet_res_containers_create(LNET_COOKIE_TYPE_MD);
        if (!recs) {
                rc = -ENOMEM;
                goto failed;
        }

        the_lnet.ln_md_containers = recs;

        rc = lnet_portals_create();
        if (rc) {
                CERROR("Failed to create portals for LNet: %d\n", rc);
                goto failed;
        }

        return 0;

 failed:
        lnet_unprepare();
        return rc;
}

static int
lnet_unprepare(void)
{
        /*
         * NB no LNET_LOCK since this is the last reference.  All LND instances
         * have shut down already, so it is safe to unlink and free all
         * descriptors, even those that appear committed to a network op (eg MD
         * with non-zero pending count)
         */
        lnet_fail_nid(LNET_NID_ANY, 0);

        LASSERT(!the_lnet.ln_refcount);
        LASSERT(list_empty(&the_lnet.ln_test_peers));
        LASSERT(list_empty(&the_lnet.ln_nis));
        LASSERT(list_empty(&the_lnet.ln_nis_cpt));
        LASSERT(list_empty(&the_lnet.ln_nis_zombie));

        lnet_portals_destroy();

        if (the_lnet.ln_md_containers) {
                lnet_res_containers_destroy(the_lnet.ln_md_containers);
                the_lnet.ln_md_containers = NULL;
        }

        if (the_lnet.ln_me_containers) {
                lnet_res_containers_destroy(the_lnet.ln_me_containers);
                the_lnet.ln_me_containers = NULL;
        }

        lnet_res_container_cleanup(&the_lnet.ln_eq_container);

        lnet_msg_containers_destroy();
        lnet_peer_tables_destroy();
        lnet_rtrpools_free(0);

        if (the_lnet.ln_counters) {
                cfs_percpt_free(the_lnet.ln_counters);
                the_lnet.ln_counters = NULL;
        }
        lnet_destroy_remote_nets_table();

        return 0;
}

struct lnet_ni  *
lnet_net2ni_locked(__u32 net, int cpt)
{
        struct list_head *tmp;
        struct lnet_ni *ni;

        LASSERT(cpt != LNET_LOCK_EX);

        list_for_each(tmp, &the_lnet.ln_nis) {
                ni = list_entry(tmp, struct lnet_ni, ni_list);

                if (LNET_NIDNET(ni->ni_nid) == net) {
                        lnet_ni_addref_locked(ni, cpt);
                        return ni;
                }
        }

        return NULL;
}

struct lnet_ni *
lnet_net2ni(__u32 net)
{
        struct lnet_ni *ni;

        lnet_net_lock(0);
        ni = lnet_net2ni_locked(net, 0);
        lnet_net_unlock(0);

        return ni;
}
EXPORT_SYMBOL(lnet_net2ni);

static unsigned int
lnet_nid_cpt_hash(lnet_nid_t nid, unsigned int number)
{
        __u64 key = nid;
        unsigned int val;

        LASSERT(number >= 1 && number <= LNET_CPT_NUMBER);

        if (number == 1)
                return 0;

        val = hash_long(key, LNET_CPT_BITS);
        /* NB: LNET_CP_NUMBER doesn't have to be PO2 */
        if (val < number)
                return val;

        return (unsigned int)(key + val + (val >> 1)) % number;
}

int
lnet_cpt_of_nid_locked(lnet_nid_t nid)
{
        struct lnet_ni *ni;

        /* must called with hold of lnet_net_lock */
        if (LNET_CPT_NUMBER == 1)
                return 0; /* the only one */

        /* take lnet_net_lock(any) would be OK */
        if (!list_empty(&the_lnet.ln_nis_cpt)) {
                list_for_each_entry(ni, &the_lnet.ln_nis_cpt, ni_cptlist) {
                        if (LNET_NIDNET(ni->ni_nid) != LNET_NIDNET(nid))
                                continue;

                        LASSERT(ni->ni_cpts);
                        return ni->ni_cpts[lnet_nid_cpt_hash
                                           (nid, ni->ni_ncpts)];
                }
        }

        return lnet_nid_cpt_hash(nid, LNET_CPT_NUMBER);
}

int
lnet_cpt_of_nid(lnet_nid_t nid)
{
        int cpt;
        int cpt2;

        if (LNET_CPT_NUMBER == 1)
                return 0; /* the only one */

        if (list_empty(&the_lnet.ln_nis_cpt))
                return lnet_nid_cpt_hash(nid, LNET_CPT_NUMBER);

        cpt = lnet_net_lock_current();
        cpt2 = lnet_cpt_of_nid_locked(nid);
        lnet_net_unlock(cpt);

        return cpt2;
}
EXPORT_SYMBOL(lnet_cpt_of_nid);

int
lnet_islocalnet(__u32 net)
{
        struct lnet_ni *ni;
        int cpt;

        cpt = lnet_net_lock_current();

        ni = lnet_net2ni_locked(net, cpt);
        if (ni)
                lnet_ni_decref_locked(ni, cpt);

        lnet_net_unlock(cpt);

        return !!ni;
}

struct lnet_ni  *
lnet_nid2ni_locked(lnet_nid_t nid, int cpt)
{
        struct lnet_ni *ni;
        struct list_head *tmp;

        LASSERT(cpt != LNET_LOCK_EX);

        list_for_each(tmp, &the_lnet.ln_nis) {
                ni = list_entry(tmp, struct lnet_ni, ni_list);

                if (ni->ni_nid == nid) {
                        lnet_ni_addref_locked(ni, cpt);
                        return ni;
                }
        }

        return NULL;
}

int
lnet_islocalnid(lnet_nid_t nid)
{
        struct lnet_ni *ni;
        int cpt;

        cpt = lnet_net_lock_current();
        ni = lnet_nid2ni_locked(nid, cpt);
        if (ni)
                lnet_ni_decref_locked(ni, cpt);
        lnet_net_unlock(cpt);

        return !!ni;
}

int
lnet_count_acceptor_nis(void)
{
        /* Return the # of NIs that need the acceptor. */
        int count = 0;
        struct list_head *tmp;
        struct lnet_ni *ni;
        int cpt;

        cpt = lnet_net_lock_current();
        list_for_each(tmp, &the_lnet.ln_nis) {
                ni = list_entry(tmp, struct lnet_ni, ni_list);

                if (ni->ni_lnd->lnd_accept)
                        count++;
        }

        lnet_net_unlock(cpt);

        return count;
}

static struct lnet_ping_info *
lnet_ping_info_create(int num_ni)
{
        struct lnet_ping_info *ping_info;
        unsigned int infosz;

        infosz = offsetof(struct lnet_ping_info, pi_ni[num_ni]);
        ping_info = kvzalloc(infosz, GFP_KERNEL);
        if (!ping_info) {
                CERROR("Can't allocate ping info[%d]\n", num_ni);
                return NULL;
        }

        ping_info->pi_nnis = num_ni;
        ping_info->pi_pid = the_lnet.ln_pid;
        ping_info->pi_magic = LNET_PROTO_PING_MAGIC;
        ping_info->pi_features = LNET_PING_FEAT_NI_STATUS;

        return ping_info;
}

static inline int
lnet_get_ni_count(void)
{
        struct lnet_ni *ni;
        int count = 0;

        lnet_net_lock(0);

        list_for_each_entry(ni, &the_lnet.ln_nis, ni_list)
                count++;

        lnet_net_unlock(0);

        return count;
}

static inline void
lnet_ping_info_free(struct lnet_ping_info *pinfo)
{
        kvfree(pinfo);
}

static void
lnet_ping_info_destroy(void)
{
        struct lnet_ni *ni;

        lnet_net_lock(LNET_LOCK_EX);

        list_for_each_entry(ni, &the_lnet.ln_nis, ni_list) {
                lnet_ni_lock(ni);
                ni->ni_status = NULL;
                lnet_ni_unlock(ni);
        }

        lnet_ping_info_free(the_lnet.ln_ping_info);
        the_lnet.ln_ping_info = NULL;

        lnet_net_unlock(LNET_LOCK_EX);
}

static void
lnet_ping_event_handler(struct lnet_event *event)
{
        struct lnet_ping_info *pinfo = event->md.user_ptr;

        if (event->unlinked)
                pinfo->pi_features = LNET_PING_FEAT_INVAL;
}

static int
lnet_ping_info_setup(struct lnet_ping_info **ppinfo,
                     struct lnet_handle_md *md_handle,
                     int ni_count, bool set_eq)
{
        struct lnet_process_id id = {LNET_NID_ANY, LNET_PID_ANY};
        struct lnet_handle_me me_handle;
        struct lnet_md md = { NULL };
        int rc, rc2;

        if (set_eq) {
                rc = LNetEQAlloc(0, lnet_ping_event_handler,
                                 &the_lnet.ln_ping_target_eq);
                if (rc) {
                        CERROR("Can't allocate ping EQ: %d\n", rc);
                        return rc;
                }
        }

        *ppinfo = lnet_ping_info_create(ni_count);
        if (!*ppinfo) {
                rc = -ENOMEM;
                goto failed_0;
        }

        rc = LNetMEAttach(LNET_RESERVED_PORTAL, id,
                          LNET_PROTO_PING_MATCHBITS, 0,
                          LNET_UNLINK, LNET_INS_AFTER,
                          &me_handle);
        if (rc) {
                CERROR("Can't create ping ME: %d\n", rc);
                goto failed_1;
        }

        /* initialize md content */
        md.start = *ppinfo;
        md.length = offsetof(struct lnet_ping_info,
                             pi_ni[(*ppinfo)->pi_nnis]);
        md.threshold = LNET_MD_THRESH_INF;
        md.max_size = 0;
        md.options = LNET_MD_OP_GET | LNET_MD_TRUNCATE |
                     LNET_MD_MANAGE_REMOTE;
        md.user_ptr  = NULL;
        md.eq_handle = the_lnet.ln_ping_target_eq;
        md.user_ptr = *ppinfo;

        rc = LNetMDAttach(me_handle, md, LNET_RETAIN, md_handle);
        if (rc) {
                CERROR("Can't attach ping MD: %d\n", rc);
                goto failed_2;
        }

        return 0;

failed_2:
        rc2 = LNetMEUnlink(me_handle);
        LASSERT(!rc2);
failed_1:
        lnet_ping_info_free(*ppinfo);
        *ppinfo = NULL;
failed_0:
        if (set_eq)
                LNetEQFree(the_lnet.ln_ping_target_eq);
        return rc;
}

static void
lnet_ping_md_unlink(struct lnet_ping_info *pinfo,
                    struct lnet_handle_md *md_handle)
{
        sigset_t blocked = cfs_block_allsigs();

        LNetMDUnlink(*md_handle);
        LNetInvalidateMDHandle(md_handle);

        /* NB md could be busy; this just starts the unlink */
        while (pinfo->pi_features != LNET_PING_FEAT_INVAL) {
                CDEBUG(D_NET, "Still waiting for ping MD to unlink\n");
                set_current_state(TASK_UNINTERRUPTIBLE);
                schedule_timeout(cfs_time_seconds(1));
        }

        cfs_restore_sigs(blocked);
}

static void
lnet_ping_info_install_locked(struct lnet_ping_info *ping_info)
{
        struct lnet_ni_status *ns;
        struct lnet_ni *ni;
        int i = 0;

        list_for_each_entry(ni, &the_lnet.ln_nis, ni_list) {
                LASSERT(i < ping_info->pi_nnis);

                ns = &ping_info->pi_ni[i];

                ns->ns_nid = ni->ni_nid;

                lnet_ni_lock(ni);
                ns->ns_status = (ni->ni_status) ?
                                 ni->ni_status->ns_status : LNET_NI_STATUS_UP;
                ni->ni_status = ns;
                lnet_ni_unlock(ni);

                i++;
        }

}

static void
lnet_ping_target_update(struct lnet_ping_info *pinfo,
                        struct lnet_handle_md md_handle)
{
        struct lnet_ping_info *old_pinfo = NULL;
        struct lnet_handle_md old_md;

        /* switch the NIs to point to the new ping info created */
        lnet_net_lock(LNET_LOCK_EX);

        if (!the_lnet.ln_routing)
                pinfo->pi_features |= LNET_PING_FEAT_RTE_DISABLED;
        lnet_ping_info_install_locked(pinfo);

        if (the_lnet.ln_ping_info) {
                old_pinfo = the_lnet.ln_ping_info;
                old_md = the_lnet.ln_ping_target_md;
        }
        the_lnet.ln_ping_target_md = md_handle;
        the_lnet.ln_ping_info = pinfo;

        lnet_net_unlock(LNET_LOCK_EX);

        if (old_pinfo) {
                /* unlink the old ping info */
                lnet_ping_md_unlink(old_pinfo, &old_md);
                lnet_ping_info_free(old_pinfo);
        }
}

static void
lnet_ping_target_fini(void)
{
        int rc;

        lnet_ping_md_unlink(the_lnet.ln_ping_info,
                            &the_lnet.ln_ping_target_md);

        rc = LNetEQFree(the_lnet.ln_ping_target_eq);
        LASSERT(!rc);

        lnet_ping_info_destroy();
}

static int
lnet_ni_tq_credits(struct lnet_ni *ni)
{
        int credits;

        LASSERT(ni->ni_ncpts >= 1);

        if (ni->ni_ncpts == 1)
                return ni->ni_maxtxcredits;

        credits = ni->ni_maxtxcredits / ni->ni_ncpts;
        credits = max(credits, 8 * ni->ni_peertxcredits);
        credits = min(credits, ni->ni_maxtxcredits);

        return credits;
}

static void
lnet_ni_unlink_locked(struct lnet_ni *ni)
{
        if (!list_empty(&ni->ni_cptlist)) {
                list_del_init(&ni->ni_cptlist);
                lnet_ni_decref_locked(ni, 0);
        }

        /* move it to zombie list and nobody can find it anymore */
        LASSERT(!list_empty(&ni->ni_list));
        list_move(&ni->ni_list, &the_lnet.ln_nis_zombie);
        lnet_ni_decref_locked(ni, 0);   /* drop ln_nis' ref */
}

static void
lnet_clear_zombies_nis_locked(void)
{
        int i;
        int islo;
        struct lnet_ni *ni;
        struct lnet_ni *temp;

        /*
         * Now wait for the NI's I just nuked to show up on ln_zombie_nis
         * and shut them down in guaranteed thread context
         */
        i = 2;
        list_for_each_entry_safe(ni, temp, &the_lnet.ln_nis_zombie, ni_list) {
                int *ref;
                int j;

                list_del_init(&ni->ni_list);
                cfs_percpt_for_each(ref, j, ni->ni_refs) {
                        if (!*ref)
                                continue;
                        /* still busy, add it back to zombie list */
                        list_add(&ni->ni_list, &the_lnet.ln_nis_zombie);
                        break;
                }

                if (!list_empty(&ni->ni_list)) {
                        lnet_net_unlock(LNET_LOCK_EX);
                        ++i;
                        if ((i & (-i)) == i) {
                                CDEBUG(D_WARNING, "Waiting for zombie LNI %s\n",
                                       libcfs_nid2str(ni->ni_nid));
                        }
                        set_current_state(TASK_UNINTERRUPTIBLE);
                        schedule_timeout(cfs_time_seconds(1));
                        lnet_net_lock(LNET_LOCK_EX);
                        continue;
                }

                ni->ni_lnd->lnd_refcount--;
                lnet_net_unlock(LNET_LOCK_EX);

                islo = ni->ni_lnd->lnd_type == LOLND;

                LASSERT(!in_interrupt());
                ni->ni_lnd->lnd_shutdown(ni);

                /*
                 * can't deref lnd anymore now; it might have unregistered
                 * itself...
                 */
                if (!islo)
                        CDEBUG(D_LNI, "Removed LNI %s\n",
                               libcfs_nid2str(ni->ni_nid));

                lnet_ni_free(ni);
                i = 2;

                lnet_net_lock(LNET_LOCK_EX);
        }
}

static void
lnet_shutdown_lndnis(void)
{
        struct lnet_ni *ni;
        struct lnet_ni *temp;
        int i;

        /* NB called holding the global mutex */

        /* All quiet on the API front */
        LASSERT(!the_lnet.ln_shutdown);
        LASSERT(!the_lnet.ln_refcount);
        LASSERT(list_empty(&the_lnet.ln_nis_zombie));

        lnet_net_lock(LNET_LOCK_EX);
        the_lnet.ln_shutdown = 1;       /* flag shutdown */

        /* Unlink NIs from the global table */
        list_for_each_entry_safe(ni, temp, &the_lnet.ln_nis, ni_list) {
                lnet_ni_unlink_locked(ni);
        }

        /* Drop the cached loopback NI. */
        if (the_lnet.ln_loni) {
                lnet_ni_decref_locked(the_lnet.ln_loni, 0);
                the_lnet.ln_loni = NULL;
        }

        lnet_net_unlock(LNET_LOCK_EX);

        /*
         * Clear lazy portals and drop delayed messages which hold refs
         * on their lnet_msg::msg_rxpeer
         */
        for (i = 0; i < the_lnet.ln_nportals; i++)
                LNetClearLazyPortal(i);

        /*
         * Clear the peer table and wait for all peers to go (they hold refs on
         * their NIs)
         */
        lnet_peer_tables_cleanup(NULL);

        lnet_net_lock(LNET_LOCK_EX);

        lnet_clear_zombies_nis_locked();
        the_lnet.ln_shutdown = 0;
        lnet_net_unlock(LNET_LOCK_EX);
}

/* shutdown down the NI and release refcount */
static void
lnet_shutdown_lndni(struct lnet_ni *ni)
{
        int i;

        lnet_net_lock(LNET_LOCK_EX);
        lnet_ni_unlink_locked(ni);
        lnet_net_unlock(LNET_LOCK_EX);

        /* clear messages for this NI on the lazy portal */
        for (i = 0; i < the_lnet.ln_nportals; i++)
                lnet_clear_lazy_portal(ni, i, "Shutting down NI");

        /* Do peer table cleanup for this ni */
        lnet_peer_tables_cleanup(ni);

        lnet_net_lock(LNET_LOCK_EX);
        lnet_clear_zombies_nis_locked();
        lnet_net_unlock(LNET_LOCK_EX);
}

static int
lnet_startup_lndni(struct lnet_ni *ni, struct lnet_ioctl_config_data *conf)
{
        struct lnet_ioctl_config_lnd_tunables *lnd_tunables = NULL;
        int rc = -EINVAL;
        int lnd_type;
        struct lnet_lnd *lnd;
        struct lnet_tx_queue *tq;
        int i;

        lnd_type = LNET_NETTYP(LNET_NIDNET(ni->ni_nid));

        LASSERT(libcfs_isknown_lnd(lnd_type));

        if (lnd_type == CIBLND || lnd_type == OPENIBLND ||
            lnd_type == IIBLND || lnd_type == VIBLND) {
                CERROR("LND %s obsoleted\n", libcfs_lnd2str(lnd_type));
                goto failed0;
        }

        /* Make sure this new NI is unique. */
        lnet_net_lock(LNET_LOCK_EX);
        rc = lnet_net_unique(LNET_NIDNET(ni->ni_nid), &the_lnet.ln_nis);
        lnet_net_unlock(LNET_LOCK_EX);
        if (!rc) {
                if (lnd_type == LOLND) {
                        lnet_ni_free(ni);
                        return 0;
                }

                CERROR("Net %s is not unique\n",
                       libcfs_net2str(LNET_NIDNET(ni->ni_nid)));
                rc = -EEXIST;
                goto failed0;
        }

        mutex_lock(&the_lnet.ln_lnd_mutex);
        lnd = lnet_find_lnd_by_type(lnd_type);

        if (!lnd) {
                mutex_unlock(&the_lnet.ln_lnd_mutex);
                rc = request_module("%s", libcfs_lnd2modname(lnd_type));
                mutex_lock(&the_lnet.ln_lnd_mutex);

                lnd = lnet_find_lnd_by_type(lnd_type);
                if (!lnd) {
                        mutex_unlock(&the_lnet.ln_lnd_mutex);
                        CERROR("Can't load LND %s, module %s, rc=%d\n",
                               libcfs_lnd2str(lnd_type),
                               libcfs_lnd2modname(lnd_type), rc);
                        rc = -EINVAL;
                        goto failed0;
                }
        }

        lnet_net_lock(LNET_LOCK_EX);
        lnd->lnd_refcount++;
        lnet_net_unlock(LNET_LOCK_EX);

        ni->ni_lnd = lnd;

        if (conf && conf->cfg_hdr.ioc_len > sizeof(*conf))
                lnd_tunables = (struct lnet_ioctl_config_lnd_tunables *)conf->cfg_bulk;

        if (lnd_tunables) {
                ni->ni_lnd_tunables = kzalloc(sizeof(*ni->ni_lnd_tunables),
                                              GFP_NOFS);
                if (!ni->ni_lnd_tunables) {
                        mutex_unlock(&the_lnet.ln_lnd_mutex);
                        rc = -ENOMEM;
                        goto failed0;
                }
                memcpy(ni->ni_lnd_tunables, lnd_tunables,
                       sizeof(*ni->ni_lnd_tunables));
        }

        /*
         * If given some LND tunable parameters, parse those now to
         * override the values in the NI structure.
         */
        if (conf) {
                if (conf->cfg_config_u.cfg_net.net_peer_rtr_credits >= 0)
                        ni->ni_peerrtrcredits =
                                conf->cfg_config_u.cfg_net.net_peer_rtr_credits;
                if (conf->cfg_config_u.cfg_net.net_peer_timeout >= 0)
                        ni->ni_peertimeout =
                                conf->cfg_config_u.cfg_net.net_peer_timeout;
                if (conf->cfg_config_u.cfg_net.net_peer_tx_credits != -1)
                        ni->ni_peertxcredits =
                                conf->cfg_config_u.cfg_net.net_peer_tx_credits;
                if (conf->cfg_config_u.cfg_net.net_max_tx_credits >= 0)
                        ni->ni_maxtxcredits =
                                conf->cfg_config_u.cfg_net.net_max_tx_credits;
        }

        rc = lnd->lnd_startup(ni);

        mutex_unlock(&the_lnet.ln_lnd_mutex);

        if (rc) {
                LCONSOLE_ERROR_MSG(0x105, "Error %d starting up LNI %s\n",
                                   rc, libcfs_lnd2str(lnd->lnd_type));
                lnet_net_lock(LNET_LOCK_EX);
                lnd->lnd_refcount--;
                lnet_net_unlock(LNET_LOCK_EX);
                goto failed0;
        }

        LASSERT(ni->ni_peertimeout <= 0 || lnd->lnd_query);

        lnet_net_lock(LNET_LOCK_EX);
        /* refcount for ln_nis */
        lnet_ni_addref_locked(ni, 0);
        list_add_tail(&ni->ni_list, &the_lnet.ln_nis);
        if (ni->ni_cpts) {
                lnet_ni_addref_locked(ni, 0);
                list_add_tail(&ni->ni_cptlist, &the_lnet.ln_nis_cpt);
        }

        lnet_net_unlock(LNET_LOCK_EX);

        if (lnd->lnd_type == LOLND) {
                lnet_ni_addref(ni);
                LASSERT(!the_lnet.ln_loni);
                the_lnet.ln_loni = ni;
                return 0;
        }

        if (!ni->ni_peertxcredits || !ni->ni_maxtxcredits) {
                LCONSOLE_ERROR_MSG(0x107, "LNI %s has no %scredits\n",
                                   libcfs_lnd2str(lnd->lnd_type),
                                   !ni->ni_peertxcredits ?
                                   "" : "per-peer ");
                /*
                 * shutdown the NI since if we get here then it must've already
                 * been started
                 */
                lnet_shutdown_lndni(ni);
                return -EINVAL;
        }

        cfs_percpt_for_each(tq, i, ni->ni_tx_queues) {
                tq->tq_credits_min =
                tq->tq_credits_max =
                tq->tq_credits = lnet_ni_tq_credits(ni);
        }

        CDEBUG(D_LNI, "Added LNI %s [%d/%d/%d/%d]\n",
               libcfs_nid2str(ni->ni_nid), ni->ni_peertxcredits,
               lnet_ni_tq_credits(ni) * LNET_CPT_NUMBER,
               ni->ni_peerrtrcredits, ni->ni_peertimeout);

        return 0;
failed0:
        lnet_ni_free(ni);
        return rc;
}

static int
lnet_startup_lndnis(struct list_head *nilist)
{
        struct lnet_ni *ni;
        int rc;
        int ni_count = 0;

        while (!list_empty(nilist)) {
                ni = list_entry(nilist->next, struct lnet_ni, ni_list);
                list_del(&ni->ni_list);
                rc = lnet_startup_lndni(ni, NULL);

                if (rc < 0)
                        goto failed;

                ni_count++;
        }

        return ni_count;
failed:
        lnet_shutdown_lndnis();

        return rc;
}

/**
 * Initialize LNet library.
 *
 * Automatically called at module loading time. Caller has to call
 * lnet_lib_exit() after a call to lnet_lib_init(), if and only if the
 * latter returned 0. It must be called exactly once.
 *
 * \retval 0 on success
 * \retval -ve on failures.
 */
int lnet_lib_init(void)
{
        int rc;

        lnet_assert_wire_constants();

        memset(&the_lnet, 0, sizeof(the_lnet));

        /* refer to global cfs_cpt_table for now */
        the_lnet.ln_cpt_table   = cfs_cpt_table;
        the_lnet.ln_cpt_number  = cfs_cpt_number(cfs_cpt_table);

        LASSERT(the_lnet.ln_cpt_number > 0);
        if (the_lnet.ln_cpt_number > LNET_CPT_MAX) {
                /* we are under risk of consuming all lh_cookie */
                CERROR("Can't have %d CPTs for LNet (max allowed is %d), please change setting of CPT-table and retry\n",
                       the_lnet.ln_cpt_number, LNET_CPT_MAX);
                return -E2BIG;
        }

        while ((1 << the_lnet.ln_cpt_bits) < the_lnet.ln_cpt_number)
                the_lnet.ln_cpt_bits++;

        rc = lnet_create_locks();
        if (rc) {
                CERROR("Can't create LNet global locks: %d\n", rc);
                return rc;
        }

        the_lnet.ln_refcount = 0;
        LNetInvalidateEQHandle(&the_lnet.ln_rc_eqh);
        INIT_LIST_HEAD(&the_lnet.ln_lnds);
        INIT_LIST_HEAD(&the_lnet.ln_rcd_zombie);
        INIT_LIST_HEAD(&the_lnet.ln_rcd_deathrow);

        /*
         * The hash table size is the number of bits it takes to express the set
         * ln_num_routes, minus 1 (better to under estimate than over so we
         * don't waste memory).
         */
        if (rnet_htable_size <= 0)
                rnet_htable_size = LNET_REMOTE_NETS_HASH_DEFAULT;
        else if (rnet_htable_size > LNET_REMOTE_NETS_HASH_MAX)
                rnet_htable_size = LNET_REMOTE_NETS_HASH_MAX;
        the_lnet.ln_remote_nets_hbits = max_t(int, 1,
                                           order_base_2(rnet_htable_size) - 1);

        /*
         * All LNDs apart from the LOLND are in separate modules.  They
         * register themselves when their module loads, and unregister
         * themselves when their module is unloaded.
         */
        lnet_register_lnd(&the_lolnd);
        return 0;
}

/**
 * Finalize LNet library.
 *
 * \pre lnet_lib_init() called with success.
 * \pre All LNet users called LNetNIFini() for matching LNetNIInit() calls.
 */
void lnet_lib_exit(void)
{
        LASSERT(!the_lnet.ln_refcount);

        while (!list_empty(&the_lnet.ln_lnds))
                lnet_unregister_lnd(list_entry(the_lnet.ln_lnds.next,
                                               struct lnet_lnd, lnd_list));
        lnet_destroy_locks();
}

/**
 * Set LNet PID and start LNet interfaces, routing, and forwarding.
 *
 * Users must call this function at least once before any other functions.
 * For each successful call there must be a corresponding call to
 * LNetNIFini(). For subsequent calls to LNetNIInit(), \a requested_pid is
 * ignored.
 *
 * The PID used by LNet may be different from the one requested.
 * See LNetGetId().
 *
 * \param requested_pid PID requested by the caller.
 *
 * \return >= 0 on success, and < 0 error code on failures.
 */
int
LNetNIInit(lnet_pid_t requested_pid)
{
        int im_a_router = 0;
        int rc;
        int ni_count;
        struct lnet_ping_info *pinfo;
        struct lnet_handle_md md_handle;
        struct list_head net_head;

        INIT_LIST_HEAD(&net_head);

        mutex_lock(&the_lnet.ln_api_mutex);

        CDEBUG(D_OTHER, "refs %d\n", the_lnet.ln_refcount);

        if (the_lnet.ln_refcount > 0) {
                rc = the_lnet.ln_refcount++;
                mutex_unlock(&the_lnet.ln_api_mutex);
                return rc;
        }

        rc = lnet_prepare(requested_pid);
        if (rc) {
                mutex_unlock(&the_lnet.ln_api_mutex);
                return rc;
        }

        /* Add in the loopback network */
        if (!lnet_ni_alloc(LNET_MKNET(LOLND, 0), NULL, &net_head)) {
                rc = -ENOMEM;
                goto err_empty_list;
        }

        /*
         * If LNet is being initialized via DLC it is possible
         * that the user requests not to load module parameters (ones which
         * are supported by DLC) on initialization.  Therefore, make sure not
         * to load networks, routes and forwarding from module parameters
         * in this case. On cleanup in case of failure only clean up
         * routes if it has been loaded
         */
        if (!the_lnet.ln_nis_from_mod_params) {
                rc = lnet_parse_networks(&net_head, lnet_get_networks());
                if (rc < 0)
                        goto err_empty_list;
        }

        ni_count = lnet_startup_lndnis(&net_head);
        if (ni_count < 0) {
                rc = ni_count;
                goto err_empty_list;
        }

        if (!the_lnet.ln_nis_from_mod_params) {
                rc = lnet_parse_routes(lnet_get_routes(), &im_a_router);
                if (rc)
                        goto err_shutdown_lndnis;

                rc = lnet_check_routes();
                if (rc)
                        goto err_destroy_routes;

                rc = lnet_rtrpools_alloc(im_a_router);
                if (rc)
                        goto err_destroy_routes;
        }

        rc = lnet_acceptor_start();
        if (rc)
                goto err_destroy_routes;

        the_lnet.ln_refcount = 1;
        /* Now I may use my own API functions... */

        rc = lnet_ping_info_setup(&pinfo, &md_handle, ni_count, true);
        if (rc)
                goto err_acceptor_stop;

        lnet_ping_target_update(pinfo, md_handle);

        rc = lnet_router_checker_start();
        if (rc)
                goto err_stop_ping;

        lnet_fault_init();
        lnet_router_debugfs_init();

        mutex_unlock(&the_lnet.ln_api_mutex);

        return 0;

err_stop_ping:
        lnet_ping_target_fini();
err_acceptor_stop:
        the_lnet.ln_refcount = 0;
        lnet_acceptor_stop();
err_destroy_routes:
        if (!the_lnet.ln_nis_from_mod_params)
                lnet_destroy_routes();
err_shutdown_lndnis:
        lnet_shutdown_lndnis();
err_empty_list:
        lnet_unprepare();
        LASSERT(rc < 0);
        mutex_unlock(&the_lnet.ln_api_mutex);
        while (!list_empty(&net_head)) {
                struct lnet_ni *ni;

                ni = list_entry(net_head.next, struct lnet_ni, ni_list);
                list_del_init(&ni->ni_list);
                lnet_ni_free(ni);
        }
        return rc;
}
EXPORT_SYMBOL(LNetNIInit);

/**
 * Stop LNet interfaces, routing, and forwarding.
 *
 * Users must call this function once for each successful call to LNetNIInit().
 * Once the LNetNIFini() operation has been started, the results of pending
 * API operations are undefined.
 *
 * \return always 0 for current implementation.
 */
int
LNetNIFini(void)
{
        mutex_lock(&the_lnet.ln_api_mutex);

        LASSERT(the_lnet.ln_refcount > 0);

        if (the_lnet.ln_refcount != 1) {
                the_lnet.ln_refcount--;
        } else {
                LASSERT(!the_lnet.ln_niinit_self);

                lnet_fault_fini();
                lnet_router_debugfs_fini();
                lnet_router_checker_stop();
                lnet_ping_target_fini();

                /* Teardown fns that use my own API functions BEFORE here */
                the_lnet.ln_refcount = 0;

                lnet_acceptor_stop();
                lnet_destroy_routes();
                lnet_shutdown_lndnis();
                lnet_unprepare();
        }

        mutex_unlock(&the_lnet.ln_api_mutex);
        return 0;
}
EXPORT_SYMBOL(LNetNIFini);

/**
 * Grabs the ni data from the ni structure and fills the out
 * parameters
 *
 * \param[in] ni network       interface structure
 * \param[out] config          NI configuration
 */
static void
lnet_fill_ni_info(struct lnet_ni *ni, struct lnet_ioctl_config_data *config)
{
        struct lnet_ioctl_config_lnd_tunables *lnd_cfg = NULL;
        struct lnet_ioctl_net_config *net_config;
        size_t min_size, tunable_size = 0;
        int i;

        if (!ni || !config)
                return;

        net_config = (struct lnet_ioctl_net_config *)config->cfg_bulk;
        if (!net_config)
                return;

        BUILD_BUG_ON(ARRAY_SIZE(ni->ni_interfaces) !=
                     ARRAY_SIZE(net_config->ni_interfaces));

        for (i = 0; i < ARRAY_SIZE(ni->ni_interfaces); i++) {
                if (!ni->ni_interfaces[i])
                        break;

                strncpy(net_config->ni_interfaces[i],
                        ni->ni_interfaces[i],
                        sizeof(net_config->ni_interfaces[i]));
        }

        config->cfg_nid = ni->ni_nid;
        config->cfg_config_u.cfg_net.net_peer_timeout = ni->ni_peertimeout;
        config->cfg_config_u.cfg_net.net_max_tx_credits = ni->ni_maxtxcredits;
        config->cfg_config_u.cfg_net.net_peer_tx_credits = ni->ni_peertxcredits;
        config->cfg_config_u.cfg_net.net_peer_rtr_credits = ni->ni_peerrtrcredits;

        net_config->ni_status = ni->ni_status->ns_status;

        if (ni->ni_cpts) {
                int num_cpts = min(ni->ni_ncpts, LNET_MAX_SHOW_NUM_CPT);

                for (i = 0; i < num_cpts; i++)
                        net_config->ni_cpts[i] = ni->ni_cpts[i];

                config->cfg_ncpts = num_cpts;
        }

        /*
         * See if user land tools sent in a newer and larger version
         * of struct lnet_tunables than what the kernel uses.
         */
        min_size = sizeof(*config) + sizeof(*net_config);

        if (config->cfg_hdr.ioc_len > min_size)
                tunable_size = config->cfg_hdr.ioc_len - min_size;

        /* Don't copy to much data to user space */
        min_size = min(tunable_size, sizeof(*ni->ni_lnd_tunables));
        lnd_cfg = (struct lnet_ioctl_config_lnd_tunables *)net_config->cfg_bulk;

        if (ni->ni_lnd_tunables && lnd_cfg && min_size) {
                memcpy(lnd_cfg, ni->ni_lnd_tunables, min_size);
                config->cfg_config_u.cfg_net.net_interface_count = 1;

                /* Tell user land that kernel side has less data */
                if (tunable_size > sizeof(*ni->ni_lnd_tunables)) {
                        min_size = tunable_size - sizeof(ni->ni_lnd_tunables);
                        config->cfg_hdr.ioc_len -= min_size;
                }
        }
}

static int
lnet_get_net_config(struct lnet_ioctl_config_data *config)
{
        struct lnet_ni *ni;
        struct list_head *tmp;
        int idx = config->cfg_count;
        int cpt, i = 0;
        int rc = -ENOENT;

        cpt = lnet_net_lock_current();

        list_for_each(tmp, &the_lnet.ln_nis) {
                if (i++ != idx)
                        continue;

                ni = list_entry(tmp, struct lnet_ni, ni_list);
                lnet_ni_lock(ni);
                lnet_fill_ni_info(ni, config);
                lnet_ni_unlock(ni);
                rc = 0;
                break;
        }

        lnet_net_unlock(cpt);
        return rc;
}

int
lnet_dyn_add_ni(lnet_pid_t requested_pid, struct lnet_ioctl_config_data *conf)
{
        char *nets = conf->cfg_config_u.cfg_net.net_intf;
        struct lnet_ping_info *pinfo;
        struct lnet_handle_md md_handle;
        struct lnet_ni *ni;
        struct list_head net_head;
        struct lnet_remotenet *rnet;
        int rc;

        INIT_LIST_HEAD(&net_head);

        /* Create a ni structure for the network string */
        rc = lnet_parse_networks(&net_head, nets);
        if (rc <= 0)
                return !rc ? -EINVAL : rc;

        mutex_lock(&the_lnet.ln_api_mutex);

        if (rc > 1) {
                rc = -EINVAL; /* only add one interface per call */
                goto failed0;
        }

        ni = list_entry(net_head.next, struct lnet_ni, ni_list);

        lnet_net_lock(LNET_LOCK_EX);
        rnet = lnet_find_net_locked(LNET_NIDNET(ni->ni_nid));
        lnet_net_unlock(LNET_LOCK_EX);
        /*
         * make sure that the net added doesn't invalidate the current
         * configuration LNet is keeping
         */
        if (rnet) {
                CERROR("Adding net %s will invalidate routing configuration\n",
                       nets);
                rc = -EUSERS;
                goto failed0;
        }

        rc = lnet_ping_info_setup(&pinfo, &md_handle, 1 + lnet_get_ni_count(),
                                  false);
        if (rc)
                goto failed0;

        list_del_init(&ni->ni_list);

        rc = lnet_startup_lndni(ni, conf);
        if (rc)
                goto failed1;

        if (ni->ni_lnd->lnd_accept) {
                rc = lnet_acceptor_start();
                if (rc < 0) {
                        /* shutdown the ni that we just started */
                        CERROR("Failed to start up acceptor thread\n");
                        lnet_shutdown_lndni(ni);
                        goto failed1;
                }
        }

        lnet_ping_target_update(pinfo, md_handle);
        mutex_unlock(&the_lnet.ln_api_mutex);

        return 0;

failed1:
        lnet_ping_md_unlink(pinfo, &md_handle);
        lnet_ping_info_free(pinfo);
failed0:
        mutex_unlock(&the_lnet.ln_api_mutex);
        while (!list_empty(&net_head)) {
                ni = list_entry(net_head.next, struct lnet_ni, ni_list);
                list_del_init(&ni->ni_list);
                lnet_ni_free(ni);
        }
        return rc;
}

int
lnet_dyn_del_ni(__u32 net)
{
        struct lnet_ni *ni;
        struct lnet_ping_info *pinfo;
        struct lnet_handle_md md_handle;
        int rc;

        /* don't allow userspace to shutdown the LOLND */
        if (LNET_NETTYP(net) == LOLND)
                return -EINVAL;

        mutex_lock(&the_lnet.ln_api_mutex);
        /* create and link a new ping info, before removing the old one */
        rc = lnet_ping_info_setup(&pinfo, &md_handle,
                                  lnet_get_ni_count() - 1, false);
        if (rc)
                goto out;

        ni = lnet_net2ni(net);
        if (!ni) {
                rc = -EINVAL;
                goto failed;
        }

        /* decrement the reference counter taken by lnet_net2ni() */
        lnet_ni_decref_locked(ni, 0);

        lnet_shutdown_lndni(ni);

        if (!lnet_count_acceptor_nis())
                lnet_acceptor_stop();

        lnet_ping_target_update(pinfo, md_handle);
        goto out;
failed:
        lnet_ping_md_unlink(pinfo, &md_handle);
        lnet_ping_info_free(pinfo);
out:
        mutex_unlock(&the_lnet.ln_api_mutex);

        return rc;
}

/**
 * LNet ioctl handler.
 *
 */
int
LNetCtl(unsigned int cmd, void *arg)
{
        struct libcfs_ioctl_data *data = arg;
        struct lnet_ioctl_config_data *config;
        struct lnet_process_id id = {0};
        struct lnet_ni *ni;
        int rc;
        unsigned long secs_passed;

        BUILD_BUG_ON(LIBCFS_IOC_DATA_MAX <
                     sizeof(struct lnet_ioctl_net_config) +
                     sizeof(struct lnet_ioctl_config_data));

        switch (cmd) {
        case IOC_LIBCFS_GET_NI:
                rc = LNetGetId(data->ioc_count, &id);
                data->ioc_nid = id.nid;
                return rc;

        case IOC_LIBCFS_FAIL_NID:
                return lnet_fail_nid(data->ioc_nid, data->ioc_count);

        case IOC_LIBCFS_ADD_ROUTE:
                config = arg;

                if (config->cfg_hdr.ioc_len < sizeof(*config))
                        return -EINVAL;

                mutex_lock(&the_lnet.ln_api_mutex);
                rc = lnet_add_route(config->cfg_net,
                                    config->cfg_config_u.cfg_route.rtr_hop,
                                    config->cfg_nid,
                                    config->cfg_config_u.cfg_route.rtr_priority);
                if (!rc) {
                        rc = lnet_check_routes();
                        if (rc)
                                lnet_del_route(config->cfg_net,
                                               config->cfg_nid);
                }
                mutex_unlock(&the_lnet.ln_api_mutex);
                return rc;

        case IOC_LIBCFS_DEL_ROUTE:
                config = arg;

                if (config->cfg_hdr.ioc_len < sizeof(*config))
                        return -EINVAL;

                mutex_lock(&the_lnet.ln_api_mutex);
                rc = lnet_del_route(config->cfg_net, config->cfg_nid);
                mutex_unlock(&the_lnet.ln_api_mutex);
                return rc;

        case IOC_LIBCFS_GET_ROUTE:
                config = arg;

                if (config->cfg_hdr.ioc_len < sizeof(*config))
                        return -EINVAL;

                return lnet_get_route(config->cfg_count,
                                      &config->cfg_net,
                                      &config->cfg_config_u.cfg_route.rtr_hop,
                                      &config->cfg_nid,
                                      &config->cfg_config_u.cfg_route.rtr_flags,
                                      &config->cfg_config_u.cfg_route.rtr_priority);

        case IOC_LIBCFS_GET_NET: {
                size_t total = sizeof(*config) +
                               sizeof(struct lnet_ioctl_net_config);
                config = arg;

                if (config->cfg_hdr.ioc_len < total)
                        return -EINVAL;

                return lnet_get_net_config(config);
        }

        case IOC_LIBCFS_GET_LNET_STATS: {
                struct lnet_ioctl_lnet_stats *lnet_stats = arg;

                if (lnet_stats->st_hdr.ioc_len < sizeof(*lnet_stats))
                        return -EINVAL;

                lnet_counters_get(&lnet_stats->st_cntrs);
                return 0;
        }

        case IOC_LIBCFS_CONFIG_RTR:
                config = arg;

                if (config->cfg_hdr.ioc_len < sizeof(*config))
                        return -EINVAL;

                mutex_lock(&the_lnet.ln_api_mutex);
                if (config->cfg_config_u.cfg_buffers.buf_enable) {
                        rc = lnet_rtrpools_enable();
                        mutex_unlock(&the_lnet.ln_api_mutex);
                        return rc;
                }
                lnet_rtrpools_disable();
                mutex_unlock(&the_lnet.ln_api_mutex);
                return 0;

        case IOC_LIBCFS_ADD_BUF:
                config = arg;

                if (config->cfg_hdr.ioc_len < sizeof(*config))
                        return -EINVAL;

                mutex_lock(&the_lnet.ln_api_mutex);
                rc = lnet_rtrpools_adjust(config->cfg_config_u.cfg_buffers.buf_tiny,
                                          config->cfg_config_u.cfg_buffers.buf_small,
                                          config->cfg_config_u.cfg_buffers.buf_large);
                mutex_unlock(&the_lnet.ln_api_mutex);
                return rc;

        case IOC_LIBCFS_GET_BUF: {
                struct lnet_ioctl_pool_cfg *pool_cfg;
                size_t total = sizeof(*config) + sizeof(*pool_cfg);

                config = arg;

                if (config->cfg_hdr.ioc_len < total)
                        return -EINVAL;

                pool_cfg = (struct lnet_ioctl_pool_cfg *)config->cfg_bulk;
                return lnet_get_rtr_pool_cfg(config->cfg_count, pool_cfg);
        }

        case IOC_LIBCFS_GET_PEER_INFO: {
                struct lnet_ioctl_peer *peer_info = arg;

                if (peer_info->pr_hdr.ioc_len < sizeof(*peer_info))
                        return -EINVAL;

                return lnet_get_peer_info(peer_info->pr_count,
                        &peer_info->pr_nid,
                        peer_info->pr_lnd_u.pr_peer_credits.cr_aliveness,
                        &peer_info->pr_lnd_u.pr_peer_credits.cr_ncpt,
                        &peer_info->pr_lnd_u.pr_peer_credits.cr_refcount,
                        &peer_info->pr_lnd_u.pr_peer_credits.cr_ni_peer_tx_credits,
                        &peer_info->pr_lnd_u.pr_peer_credits.cr_peer_tx_credits,
                        &peer_info->pr_lnd_u.pr_peer_credits.cr_peer_rtr_credits,
                        &peer_info->pr_lnd_u.pr_peer_credits.cr_peer_min_rtr_credits,
                        &peer_info->pr_lnd_u.pr_peer_credits.cr_peer_tx_qnob);
        }

        case IOC_LIBCFS_NOTIFY_ROUTER:
                secs_passed = (ktime_get_real_seconds() - data->ioc_u64[0]);
                secs_passed *= msecs_to_jiffies(MSEC_PER_SEC);

                return lnet_notify(NULL, data->ioc_nid, data->ioc_flags,
                                   jiffies - secs_passed);

        case IOC_LIBCFS_LNET_DIST:
                rc = LNetDist(data->ioc_nid, &data->ioc_nid, &data->ioc_u32[1]);
                if (rc < 0 && rc != -EHOSTUNREACH)
                        return rc;

                data->ioc_u32[0] = rc;
                return 0;

        case IOC_LIBCFS_TESTPROTOCOMPAT:
                lnet_net_lock(LNET_LOCK_EX);
                the_lnet.ln_testprotocompat = data->ioc_flags;
                lnet_net_unlock(LNET_LOCK_EX);
                return 0;

        case IOC_LIBCFS_LNET_FAULT:
                return lnet_fault_ctl(data->ioc_flags, data);

        case IOC_LIBCFS_PING:
                id.nid = data->ioc_nid;
                id.pid = data->ioc_u32[0];
                rc = lnet_ping(id, data->ioc_u32[1], /* timeout */
                               data->ioc_pbuf1,
                               data->ioc_plen1 / sizeof(struct lnet_process_id));
                if (rc < 0)
                        return rc;
                data->ioc_count = rc;
                return 0;

        default:
                ni = lnet_net2ni(data->ioc_net);
                if (!ni)
                        return -EINVAL;

                if (!ni->ni_lnd->lnd_ctl)
                        rc = -EINVAL;
                else
                        rc = ni->ni_lnd->lnd_ctl(ni, cmd, arg);

                lnet_ni_decref(ni);
                return rc;
        }
        /* not reached */
}
EXPORT_SYMBOL(LNetCtl);

void LNetDebugPeer(struct lnet_process_id id)
{
        lnet_debug_peer(id.nid);
}
EXPORT_SYMBOL(LNetDebugPeer);

/**
 * Retrieve the lnet_process_id ID of LNet interface at \a index. Note that
 * all interfaces share a same PID, as requested by LNetNIInit().
 *
 * \param index Index of the interface to look up.
 * \param id On successful return, this location will hold the
 * lnet_process_id ID of the interface.
 *
 * \retval 0 If an interface exists at \a index.
 * \retval -ENOENT If no interface has been found.
 */
int
LNetGetId(unsigned int index, struct lnet_process_id *id)
{
        struct lnet_ni *ni;
        struct list_head *tmp;
        int cpt;
        int rc = -ENOENT;

        LASSERT(the_lnet.ln_refcount > 0);

        cpt = lnet_net_lock_current();

        list_for_each(tmp, &the_lnet.ln_nis) {
                if (index--)
                        continue;

                ni = list_entry(tmp, struct lnet_ni, ni_list);

                id->nid = ni->ni_nid;
                id->pid = the_lnet.ln_pid;
                rc = 0;
                break;
        }

        lnet_net_unlock(cpt);
        return rc;
}
EXPORT_SYMBOL(LNetGetId);

static int lnet_ping(struct lnet_process_id id, int timeout_ms,
                     struct lnet_process_id __user *ids, int n_ids)
{
        struct lnet_handle_eq eqh;
        struct lnet_handle_md mdh;
        struct lnet_event event;
        struct lnet_md md = { NULL };
        int which;
        int unlinked = 0;
        int replied = 0;
        const int a_long_time = 60000; /* mS */
        int infosz;
        struct lnet_ping_info *info;
        struct lnet_process_id tmpid;
        int i;
        int nob;
        int rc;
        int rc2;
        sigset_t blocked;

        infosz = offsetof(struct lnet_ping_info, pi_ni[n_ids]);

        if (n_ids <= 0 ||
            id.nid == LNET_NID_ANY ||
            timeout_ms > 500000 ||            /* arbitrary limit! */
            n_ids > 20)                  /* arbitrary limit! */
                return -EINVAL;

        if (id.pid == LNET_PID_ANY)
                id.pid = LNET_PID_LUSTRE;

        info = kzalloc(infosz, GFP_KERNEL);
        if (!info)
                return -ENOMEM;

        /* NB 2 events max (including any unlink event) */
        rc = LNetEQAlloc(2, LNET_EQ_HANDLER_NONE, &eqh);
        if (rc) {
                CERROR("Can't allocate EQ: %d\n", rc);
                goto out_0;
        }

        /* initialize md content */
        md.start     = info;
        md.length    = infosz;
        md.threshold = 2; /*GET/REPLY*/
        md.max_size  = 0;
        md.options   = LNET_MD_TRUNCATE;
        md.user_ptr  = NULL;
        md.eq_handle = eqh;

        rc = LNetMDBind(md, LNET_UNLINK, &mdh);
        if (rc) {
                CERROR("Can't bind MD: %d\n", rc);
                goto out_1;
        }

        rc = LNetGet(LNET_NID_ANY, mdh, id,
                     LNET_RESERVED_PORTAL,
                     LNET_PROTO_PING_MATCHBITS, 0);

        if (rc) {
                /* Don't CERROR; this could be deliberate! */

                rc2 = LNetMDUnlink(mdh);
                LASSERT(!rc2);

                /* NB must wait for the UNLINK event below... */
                unlinked = 1;
                timeout_ms = a_long_time;
        }

        do {
                /* MUST block for unlink to complete */
                if (unlinked)
                        blocked = cfs_block_allsigs();

                rc2 = LNetEQPoll(&eqh, 1, timeout_ms, &event, &which);

                if (unlinked)
                        cfs_restore_sigs(blocked);

                CDEBUG(D_NET, "poll %d(%d %d)%s\n", rc2,
                       (rc2 <= 0) ? -1 : event.type,
                       (rc2 <= 0) ? -1 : event.status,
                       (rc2 > 0 && event.unlinked) ? " unlinked" : "");

                LASSERT(rc2 != -EOVERFLOW);     /* can't miss anything */

                if (rc2 <= 0 || event.status) {
                        /* timeout or error */
                        if (!replied && !rc)
                                rc = (rc2 < 0) ? rc2 :
                                     !rc2 ? -ETIMEDOUT :
                                     event.status;

                        if (!unlinked) {
                                /* Ensure completion in finite time... */
                                LNetMDUnlink(mdh);
                                /* No assertion (racing with network) */
                                unlinked = 1;
                                timeout_ms = a_long_time;
                        } else if (!rc2) {
                                /* timed out waiting for unlink */
                                CWARN("ping %s: late network completion\n",
                                      libcfs_id2str(id));
                        }
                } else if (event.type == LNET_EVENT_REPLY) {
                        replied = 1;
                        rc = event.mlength;
                }

        } while (rc2 <= 0 || !event.unlinked);

        if (!replied) {
                if (rc >= 0)
                        CWARN("%s: Unexpected rc >= 0 but no reply!\n",
                              libcfs_id2str(id));
                rc = -EIO;
                goto out_1;
        }

        nob = rc;
        LASSERT(nob >= 0 && nob <= infosz);

        rc = -EPROTO;                      /* if I can't parse... */

        if (nob < 8) {
                /* can't check magic/version */
                CERROR("%s: ping info too short %d\n",
                       libcfs_id2str(id), nob);
                goto out_1;
        }

        if (info->pi_magic == __swab32(LNET_PROTO_PING_MAGIC)) {
                lnet_swap_pinginfo(info);
        } else if (info->pi_magic != LNET_PROTO_PING_MAGIC) {
                CERROR("%s: Unexpected magic %08x\n",
                       libcfs_id2str(id), info->pi_magic);
                goto out_1;
        }

        if (!(info->pi_features & LNET_PING_FEAT_NI_STATUS)) {
                CERROR("%s: ping w/o NI status: 0x%x\n",
                       libcfs_id2str(id), info->pi_features);
                goto out_1;
        }

        if (nob < offsetof(struct lnet_ping_info, pi_ni[0])) {
                CERROR("%s: Short reply %d(%d min)\n", libcfs_id2str(id),
                       nob, (int)offsetof(struct lnet_ping_info, pi_ni[0]));
                goto out_1;
        }

        if (info->pi_nnis < n_ids)
                n_ids = info->pi_nnis;

        if (nob < offsetof(struct lnet_ping_info, pi_ni[n_ids])) {
                CERROR("%s: Short reply %d(%d expected)\n", libcfs_id2str(id),
                       nob, (int)offsetof(struct lnet_ping_info, pi_ni[n_ids]));
                goto out_1;
        }

        rc = -EFAULT;                      /* If I SEGV... */

        memset(&tmpid, 0, sizeof(tmpid));
        for (i = 0; i < n_ids; i++) {
                tmpid.pid = info->pi_pid;
                tmpid.nid = info->pi_ni[i].ns_nid;
                if (copy_to_user(&ids[i], &tmpid, sizeof(tmpid)))
                        goto out_1;
        }
        rc = info->pi_nnis;

 out_1:
        rc2 = LNetEQFree(eqh);
        if (rc2)
                CERROR("rc2 %d\n", rc2);
        LASSERT(!rc2);

 out_0:
        kfree(info);
        return rc;
}