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	Version: linux-6.0.1 spark-3.0.0 hadoop-3.2.0-src hadoop-3.3.0-src spark-2.4.7 linux-4.15.13 hadoop-2.7.4-src Revert   Change

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  *  Shared Memory Communications over RDMA (SMC-R) and RoCE
  *
  *  AF_SMC protocol family socket handler keeping the AF_INET sock address type
  *  applies to SOCK_STREAM sockets only
  *  offers an alternative communication option for TCP-protocol sockets
  *  applicable with RoCE-cards only
  *
  *  Initial restrictions:
  *    - support for alternate links postponed
  *
  *  Copyright IBM Corp. 2016, 2018
  *
  *  Author(s):  Ursula Braun <ubraun@linux.vnet.ibm.com>
  *              based on prototype from Frank Blaschka
  */
 
 #define KMSG_COMPONENT "smc"
 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
 
 #include <linux/module.h>
 #include <linux/socket.h>
 #include <linux/workqueue.h>
 #include <linux/in.h>
 #include <linux/sched/signal.h>
 #include <linux/if_vlan.h>
 #include <linux/rcupdate_wait.h>
 #include <linux/ctype.h>
 
 #include <net/sock.h>
 #include <net/tcp.h>
 #include <net/smc.h>
 #include <asm/ioctls.h>
 
 #include <net/net_namespace.h>
 #include <net/netns/generic.h>
 #include "smc_netns.h"
 
 #include "smc.h"
 #include "smc_clc.h"
 #include "smc_llc.h"
 #include "smc_cdc.h"
 #include "smc_core.h"
 #include "smc_ib.h"
 #include "smc_ism.h"
 #include "smc_pnet.h"
 #include "smc_netlink.h"
 #include "smc_tx.h"
 #include "smc_rx.h"
 #include "smc_close.h"
 #include "smc_stats.h"
 #include "smc_tracepoint.h"
 #include "smc_sysctl.h"
 
 static DEFINE_MUTEX(smc_server_lgr_pending);    /* serialize link group
                          * creation on server
                          */
 static DEFINE_MUTEX(smc_client_lgr_pending);    /* serialize link group
                          * creation on client
                          */
 
 static struct workqueue_struct  *smc_tcp_ls_wq; /* wq for tcp listen work */
 struct workqueue_struct *smc_hs_wq; /* wq for handshake work */
 struct workqueue_struct *smc_close_wq;  /* wq for close work */
 
 static void smc_tcp_listen_work(struct work_struct *);
 static void smc_connect_work(struct work_struct *);
 
 int smc_nl_dump_hs_limitation(struct sk_buff *skb, struct netlink_callback *cb)
 {
     struct smc_nl_dmp_ctx *cb_ctx = smc_nl_dmp_ctx(cb);
     void *hdr;
 
     if (cb_ctx->pos[0])
         goto out;
 
     hdr = genlmsg_put(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq,
               &smc_gen_nl_family, NLM_F_MULTI,
               SMC_NETLINK_DUMP_HS_LIMITATION);
     if (!hdr)
         return -ENOMEM;
 
     if (nla_put_u8(skb, SMC_NLA_HS_LIMITATION_ENABLED,
                sock_net(skb->sk)->smc.limit_smc_hs))
         goto err;
 
     genlmsg_end(skb, hdr);
     cb_ctx->pos[0] = 1;
 out:
     return skb->len;
 err:
     genlmsg_cancel(skb, hdr);
     return -EMSGSIZE;
 }
 
 int smc_nl_enable_hs_limitation(struct sk_buff *skb, struct genl_info *info)
 {
     sock_net(skb->sk)->smc.limit_smc_hs = true;
     return 0;
 }
 
 int smc_nl_disable_hs_limitation(struct sk_buff *skb, struct genl_info *info)
 {
     sock_net(skb->sk)->smc.limit_smc_hs = false;
     return 0;
 }
 
 static void smc_set_keepalive(struct sock *sk, int val)
 {
     struct smc_sock *smc = smc_sk(sk);
 
     smc->clcsock->sk->sk_prot->keepalive(smc->clcsock->sk, val);
 }
 
 static struct sock *smc_tcp_syn_recv_sock(const struct sock *sk,
                       struct sk_buff *skb,
                       struct request_sock *req,
                       struct dst_entry *dst,
                       struct request_sock *req_unhash,
                       bool *own_req)
 {
     struct smc_sock *smc;
     struct sock *child;
 
     smc = smc_clcsock_user_data(sk);
 
     if (READ_ONCE(sk->sk_ack_backlog) + atomic_read(&smc->queued_smc_hs) >
                 sk->sk_max_ack_backlog)
         goto drop;
 
     if (sk_acceptq_is_full(&smc->sk)) {
         NET_INC_STATS(sock_net(sk), LINUX_MIB_LISTENOVERFLOWS);
         goto drop;
     }
 
     /* passthrough to original syn recv sock fct */
     child = smc->ori_af_ops->syn_recv_sock(sk, skb, req, dst, req_unhash,
                            own_req);
     /* child must not inherit smc or its ops */
     if (child) {
         rcu_assign_sk_user_data(child, NULL);
 
         /* v4-mapped sockets don't inherit parent ops. Don't restore. */
         if (inet_csk(child)->icsk_af_ops == inet_csk(sk)->icsk_af_ops)
             inet_csk(child)->icsk_af_ops = smc->ori_af_ops;
     }
     return child;
 
 drop:
     dst_release(dst);
     tcp_listendrop(sk);
     return NULL;
 }
 
 static bool smc_hs_congested(const struct sock *sk)
 {
     const struct smc_sock *smc;
 
     smc = smc_clcsock_user_data(sk);
 
     if (!smc)
         return true;
 
     if (workqueue_congested(WORK_CPU_UNBOUND, smc_hs_wq))
         return true;
 
     return false;
 }
 
 static struct smc_hashinfo smc_v4_hashinfo = {
     .lock = __RW_LOCK_UNLOCKED(smc_v4_hashinfo.lock),
 };
 
 static struct smc_hashinfo smc_v6_hashinfo = {
     .lock = __RW_LOCK_UNLOCKED(smc_v6_hashinfo.lock),
 };
 
 int smc_hash_sk(struct sock *sk)
 {
     struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
     struct hlist_head *head;
 
     head = &h->ht;
 
     write_lock_bh(&h->lock);
     sk_add_node(sk, head);
     write_unlock_bh(&h->lock);
     sock_prot_inuse_add(sock_net(sk), sk->sk_prot, 1);
 
     return 0;
 }
 EXPORT_SYMBOL_GPL(smc_hash_sk);
 
 void smc_unhash_sk(struct sock *sk)
 {
     struct smc_hashinfo *h = sk->sk_prot->h.smc_hash;
 
     write_lock_bh(&h->lock);
     if (sk_del_node_init(sk))
         sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
     write_unlock_bh(&h->lock);
 }
 EXPORT_SYMBOL_GPL(smc_unhash_sk);
 
 /* This will be called before user really release sock_lock. So do the
  * work which we didn't do because of user hold the sock_lock in the
  * BH context
  */
 static void smc_release_cb(struct sock *sk)
 {
     struct smc_sock *smc = smc_sk(sk);
 
     if (smc->conn.tx_in_release_sock) {
         smc_tx_pending(&smc->conn);
         smc->conn.tx_in_release_sock = false;
     }
 }
 
 struct proto smc_proto = {
     .name       = "SMC",
     .owner      = THIS_MODULE,
     .keepalive  = smc_set_keepalive,
     .hash       = smc_hash_sk,
     .unhash     = smc_unhash_sk,
     .release_cb = smc_release_cb,
     .obj_size   = sizeof(struct smc_sock),
     .h.smc_hash = &smc_v4_hashinfo,
     .slab_flags = SLAB_TYPESAFE_BY_RCU,
 };
 EXPORT_SYMBOL_GPL(smc_proto);
 
 struct proto smc_proto6 = {
     .name       = "SMC6",
     .owner      = THIS_MODULE,
     .keepalive  = smc_set_keepalive,
     .hash       = smc_hash_sk,
     .unhash     = smc_unhash_sk,
     .release_cb = smc_release_cb,
     .obj_size   = sizeof(struct smc_sock),
     .h.smc_hash = &smc_v6_hashinfo,
     .slab_flags = SLAB_TYPESAFE_BY_RCU,
 };
 EXPORT_SYMBOL_GPL(smc_proto6);
 
 static void smc_fback_restore_callbacks(struct smc_sock *smc)
 {
     struct sock *clcsk = smc->clcsock->sk;
 
     write_lock_bh(&clcsk->sk_callback_lock);
     clcsk->sk_user_data = NULL;
 
     smc_clcsock_restore_cb(&clcsk->sk_state_change, &smc->clcsk_state_change);
     smc_clcsock_restore_cb(&clcsk->sk_data_ready, &smc->clcsk_data_ready);
     smc_clcsock_restore_cb(&clcsk->sk_write_space, &smc->clcsk_write_space);
     smc_clcsock_restore_cb(&clcsk->sk_error_report, &smc->clcsk_error_report);
 
     write_unlock_bh(&clcsk->sk_callback_lock);
 }
 
 static void smc_restore_fallback_changes(struct smc_sock *smc)
 {
     if (smc->clcsock->file) { /* non-accepted sockets have no file yet */
         smc->clcsock->file->private_data = smc->sk.sk_socket;
         smc->clcsock->file = NULL;
         smc_fback_restore_callbacks(smc);
     }
 }
 
 static int __smc_release(struct smc_sock *smc)
 {
     struct sock *sk = &smc->sk;
     int rc = 0;
 
     if (!smc->use_fallback) {
         rc = smc_close_active(smc);
         sock_set_flag(sk, SOCK_DEAD);
         sk->sk_shutdown |= SHUTDOWN_MASK;
     } else {
         if (sk->sk_state != SMC_CLOSED) {
             if (sk->sk_state != SMC_LISTEN &&
                 sk->sk_state != SMC_INIT)
                 sock_put(sk); /* passive closing */
             if (sk->sk_state == SMC_LISTEN) {
                 /* wake up clcsock accept */
                 rc = kernel_sock_shutdown(smc->clcsock,
                               SHUT_RDWR);
             }
             sk->sk_state = SMC_CLOSED;
             sk->sk_state_change(sk);
         }
         smc_restore_fallback_changes(smc);
     }
 
     sk->sk_prot->unhash(sk);
 
     if (sk->sk_state == SMC_CLOSED) {
         if (smc->clcsock) {
             release_sock(sk);
             smc_clcsock_release(smc);
             lock_sock(sk);
         }
         if (!smc->use_fallback)
             smc_conn_free(&smc->conn);
     }
 
     return rc;
 }
 
 static int smc_release(struct socket *sock)
 {
     struct sock *sk = sock->sk;
     struct smc_sock *smc;
     int old_state, rc = 0;
 
     if (!sk)
         goto out;
 
     sock_hold(sk); /* sock_put below */
     smc = smc_sk(sk);
 
     old_state = sk->sk_state;
 
     /* cleanup for a dangling non-blocking connect */
     if (smc->connect_nonblock && old_state == SMC_INIT)
         tcp_abort(smc->clcsock->sk, ECONNABORTED);
 
     if (cancel_work_sync(&smc->connect_work))
         sock_put(&smc->sk); /* sock_hold in smc_connect for passive closing */
 
     if (sk->sk_state == SMC_LISTEN)
         /* smc_close_non_accepted() is called and acquires
          * sock lock for child sockets again
          */
         lock_sock_nested(sk, SINGLE_DEPTH_NESTING);
     else
         lock_sock(sk);
 
     if (old_state == SMC_INIT && sk->sk_state == SMC_ACTIVE &&
         !smc->use_fallback)
         smc_close_active_abort(smc);
 
     rc = __smc_release(smc);
 
     /* detach socket */
     sock_orphan(sk);
     sock->sk = NULL;
     release_sock(sk);
 
     sock_put(sk); /* sock_hold above */
     sock_put(sk); /* final sock_put */
 out:
     return rc;
 }
 
 static void smc_destruct(struct sock *sk)
 {
     if (sk->sk_state != SMC_CLOSED)
         return;
     if (!sock_flag(sk, SOCK_DEAD))
         return;
 
     sk_refcnt_debug_dec(sk);
 }
 
 static struct sock *smc_sock_alloc(struct net *net, struct socket *sock,
                    int protocol)
 {
     struct smc_sock *smc;
     struct proto *prot;
     struct sock *sk;
 
     prot = (protocol == SMCPROTO_SMC6) ? &smc_proto6 : &smc_proto;
     sk = sk_alloc(net, PF_SMC, GFP_KERNEL, prot, 0);
     if (!sk)
         return NULL;
 
     sock_init_data(sock, sk); /* sets sk_refcnt to 1 */
     sk->sk_state = SMC_INIT;
     sk->sk_destruct = smc_destruct;
     sk->sk_protocol = protocol;
     smc = smc_sk(sk);
     INIT_WORK(&smc->tcp_listen_work, smc_tcp_listen_work);
     INIT_WORK(&smc->connect_work, smc_connect_work);
     INIT_DELAYED_WORK(&smc->conn.tx_work, smc_tx_work);
     INIT_LIST_HEAD(&smc->accept_q);
     spin_lock_init(&smc->accept_q_lock);
     spin_lock_init(&smc->conn.send_lock);
     sk->sk_prot->hash(sk);
     sk_refcnt_debug_inc(sk);
     mutex_init(&smc->clcsock_release_lock);
     smc_init_saved_callbacks(smc);
 
     return sk;
 }
 
 static int smc_bind(struct socket *sock, struct sockaddr *uaddr,
             int addr_len)
 {
     struct sockaddr_in *addr = (struct sockaddr_in *)uaddr;
     struct sock *sk = sock->sk;
     struct smc_sock *smc;
     int rc;
 
     smc = smc_sk(sk);
 
     /* replicate tests from inet_bind(), to be safe wrt. future changes */
     rc = -EINVAL;
     if (addr_len < sizeof(struct sockaddr_in))
         goto out;
 
     rc = -EAFNOSUPPORT;
     if (addr->sin_family != AF_INET &&
         addr->sin_family != AF_INET6 &&
         addr->sin_family != AF_UNSPEC)
         goto out;
     /* accept AF_UNSPEC (mapped to AF_INET) only if s_addr is INADDR_ANY */
     if (addr->sin_family == AF_UNSPEC &&
         addr->sin_addr.s_addr != htonl(INADDR_ANY))
         goto out;
 
     lock_sock(sk);
 
     /* Check if socket is already active */
     rc = -EINVAL;
     if (sk->sk_state != SMC_INIT || smc->connect_nonblock)
         goto out_rel;
 
     smc->clcsock->sk->sk_reuse = sk->sk_reuse;
     rc = kernel_bind(smc->clcsock, uaddr, addr_len);
 
 out_rel:
     release_sock(sk);
 out:
     return rc;
 }
 
 static void smc_copy_sock_settings(struct sock *nsk, struct sock *osk,
                    unsigned long mask)
 {
     /* options we don't get control via setsockopt for */
     nsk->sk_type = osk->sk_type;
     nsk->sk_sndbuf = osk->sk_sndbuf;
     nsk->sk_rcvbuf = osk->sk_rcvbuf;
     nsk->sk_sndtimeo = osk->sk_sndtimeo;
     nsk->sk_rcvtimeo = osk->sk_rcvtimeo;
     nsk->sk_mark = osk->sk_mark;
     nsk->sk_priority = osk->sk_priority;
     nsk->sk_rcvlowat = osk->sk_rcvlowat;
     nsk->sk_bound_dev_if = osk->sk_bound_dev_if;
     nsk->sk_err = osk->sk_err;
 
     nsk->sk_flags &= ~mask;
     nsk->sk_flags |= osk->sk_flags & mask;
 }
 
 #define SK_FLAGS_SMC_TO_CLC ((1UL << SOCK_URGINLINE) | \
                  (1UL << SOCK_KEEPOPEN) | \
                  (1UL << SOCK_LINGER) | \
                  (1UL << SOCK_BROADCAST) | \
                  (1UL << SOCK_TIMESTAMP) | \
                  (1UL << SOCK_DBG) | \
                  (1UL << SOCK_RCVTSTAMP) | \
                  (1UL << SOCK_RCVTSTAMPNS) | \
                  (1UL << SOCK_LOCALROUTE) | \
                  (1UL << SOCK_TIMESTAMPING_RX_SOFTWARE) | \
                  (1UL << SOCK_RXQ_OVFL) | \
                  (1UL << SOCK_WIFI_STATUS) | \
                  (1UL << SOCK_NOFCS) | \
                  (1UL << SOCK_FILTER_LOCKED) | \
                  (1UL << SOCK_TSTAMP_NEW))
 /* copy only relevant settings and flags of SOL_SOCKET level from smc to
  * clc socket (since smc is not called for these options from net/core)
  */
 static void smc_copy_sock_settings_to_clc(struct smc_sock *smc)
 {
     smc_copy_sock_settings(smc->clcsock->sk, &smc->sk, SK_FLAGS_SMC_TO_CLC);
 }
 
 #define SK_FLAGS_CLC_TO_SMC ((1UL << SOCK_URGINLINE) | \
                  (1UL << SOCK_KEEPOPEN) | \
                  (1UL << SOCK_LINGER) | \
                  (1UL << SOCK_DBG))
 /* copy only settings and flags relevant for smc from clc to smc socket */
 static void smc_copy_sock_settings_to_smc(struct smc_sock *smc)
 {
     smc_copy_sock_settings(&smc->sk, smc->clcsock->sk, SK_FLAGS_CLC_TO_SMC);
 }
 
 /* register the new vzalloced sndbuf on all links */
 static int smcr_lgr_reg_sndbufs(struct smc_link *link,
                 struct smc_buf_desc *snd_desc)
 {
     struct smc_link_group *lgr = link->lgr;
     int i, rc = 0;
 
     if (!snd_desc->is_vm)
         return -EINVAL;
 
     /* protect against parallel smcr_link_reg_buf() */
     mutex_lock(&lgr->llc_conf_mutex);
     for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
         if (!smc_link_active(&lgr->lnk[i]))
             continue;
         rc = smcr_link_reg_buf(&lgr->lnk[i], snd_desc);
         if (rc)
             break;
     }
     mutex_unlock(&lgr->llc_conf_mutex);
     return rc;
 }
 
 /* register the new rmb on all links */
 static int smcr_lgr_reg_rmbs(struct smc_link *link,
                  struct smc_buf_desc *rmb_desc)
 {
     struct smc_link_group *lgr = link->lgr;
     int i, rc = 0;
 
     rc = smc_llc_flow_initiate(lgr, SMC_LLC_FLOW_RKEY);
     if (rc)
         return rc;
     /* protect against parallel smc_llc_cli_rkey_exchange() and
      * parallel smcr_link_reg_buf()
      */
     mutex_lock(&lgr->llc_conf_mutex);
     for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
         if (!smc_link_active(&lgr->lnk[i]))
             continue;
         rc = smcr_link_reg_buf(&lgr->lnk[i], rmb_desc);
         if (rc)
             goto out;
     }
 
     /* exchange confirm_rkey msg with peer */
     rc = smc_llc_do_confirm_rkey(link, rmb_desc);
     if (rc) {
         rc = -EFAULT;
         goto out;
     }
     rmb_desc->is_conf_rkey = true;
 out:
     mutex_unlock(&lgr->llc_conf_mutex);
     smc_llc_flow_stop(lgr, &lgr->llc_flow_lcl);
     return rc;
 }
 
 static int smcr_clnt_conf_first_link(struct smc_sock *smc)
 {
     struct smc_link *link = smc->conn.lnk;
     struct smc_llc_qentry *qentry;
     int rc;
 
     /* receive CONFIRM LINK request from server over RoCE fabric */
     qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
                   SMC_LLC_CONFIRM_LINK);
     if (!qentry) {
         struct smc_clc_msg_decline dclc;
 
         rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
                       SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
         return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
     }
     smc_llc_save_peer_uid(qentry);
     rc = smc_llc_eval_conf_link(qentry, SMC_LLC_REQ);
     smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
     if (rc)
         return SMC_CLC_DECL_RMBE_EC;
 
     rc = smc_ib_modify_qp_rts(link);
     if (rc)
         return SMC_CLC_DECL_ERR_RDYLNK;
 
     smc_wr_remember_qp_attr(link);
 
     /* reg the sndbuf if it was vzalloced */
     if (smc->conn.sndbuf_desc->is_vm) {
         if (smcr_link_reg_buf(link, smc->conn.sndbuf_desc))
             return SMC_CLC_DECL_ERR_REGBUF;
     }
 
     /* reg the rmb */
     if (smcr_link_reg_buf(link, smc->conn.rmb_desc))
         return SMC_CLC_DECL_ERR_REGBUF;
 
     /* confirm_rkey is implicit on 1st contact */
     smc->conn.rmb_desc->is_conf_rkey = true;
 
     /* send CONFIRM LINK response over RoCE fabric */
     rc = smc_llc_send_confirm_link(link, SMC_LLC_RESP);
     if (rc < 0)
         return SMC_CLC_DECL_TIMEOUT_CL;
 
     smc_llc_link_active(link);
     smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
 
     /* optional 2nd link, receive ADD LINK request from server */
     qentry = smc_llc_wait(link->lgr, NULL, SMC_LLC_WAIT_TIME,
                   SMC_LLC_ADD_LINK);
     if (!qentry) {
         struct smc_clc_msg_decline dclc;
 
         rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
                       SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
         if (rc == -EAGAIN)
             rc = 0; /* no DECLINE received, go with one link */
         return rc;
     }
     smc_llc_flow_qentry_clr(&link->lgr->llc_flow_lcl);
     smc_llc_cli_add_link(link, qentry);
     return 0;
 }
 
 static bool smc_isascii(char *hostname)
 {
     int i;
 
     for (i = 0; i < SMC_MAX_HOSTNAME_LEN; i++)
         if (!isascii(hostname[i]))
             return false;
     return true;
 }
 
 static void smc_conn_save_peer_info_fce(struct smc_sock *smc,
                     struct smc_clc_msg_accept_confirm *clc)
 {
     struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
         (struct smc_clc_msg_accept_confirm_v2 *)clc;
     struct smc_clc_first_contact_ext *fce;
     int clc_v2_len;
 
     if (clc->hdr.version == SMC_V1 ||
         !(clc->hdr.typev2 & SMC_FIRST_CONTACT_MASK))
         return;
 
     if (smc->conn.lgr->is_smcd) {
         memcpy(smc->conn.lgr->negotiated_eid, clc_v2->d1.eid,
                SMC_MAX_EID_LEN);
         clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
                      d1);
     } else {
         memcpy(smc->conn.lgr->negotiated_eid, clc_v2->r1.eid,
                SMC_MAX_EID_LEN);
         clc_v2_len = offsetofend(struct smc_clc_msg_accept_confirm_v2,
                      r1);
     }
     fce = (struct smc_clc_first_contact_ext *)(((u8 *)clc_v2) + clc_v2_len);
     smc->conn.lgr->peer_os = fce->os_type;
     smc->conn.lgr->peer_smc_release = fce->release;
     if (smc_isascii(fce->hostname))
         memcpy(smc->conn.lgr->peer_hostname, fce->hostname,
                SMC_MAX_HOSTNAME_LEN);
 }
 
 static void smcr_conn_save_peer_info(struct smc_sock *smc,
                      struct smc_clc_msg_accept_confirm *clc)
 {
     int bufsize = smc_uncompress_bufsize(clc->r0.rmbe_size);
 
     smc->conn.peer_rmbe_idx = clc->r0.rmbe_idx;
     smc->conn.local_tx_ctrl.token = ntohl(clc->r0.rmbe_alert_token);
     smc->conn.peer_rmbe_size = bufsize;
     atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
     smc->conn.tx_off = bufsize * (smc->conn.peer_rmbe_idx - 1);
 }
 
 static void smcd_conn_save_peer_info(struct smc_sock *smc,
                      struct smc_clc_msg_accept_confirm *clc)
 {
     int bufsize = smc_uncompress_bufsize(clc->d0.dmbe_size);
 
     smc->conn.peer_rmbe_idx = clc->d0.dmbe_idx;
     smc->conn.peer_token = clc->d0.token;
     /* msg header takes up space in the buffer */
     smc->conn.peer_rmbe_size = bufsize - sizeof(struct smcd_cdc_msg);
     atomic_set(&smc->conn.peer_rmbe_space, smc->conn.peer_rmbe_size);
     smc->conn.tx_off = bufsize * smc->conn.peer_rmbe_idx;
 }
 
 static void smc_conn_save_peer_info(struct smc_sock *smc,
                     struct smc_clc_msg_accept_confirm *clc)
 {
     if (smc->conn.lgr->is_smcd)
         smcd_conn_save_peer_info(smc, clc);
     else
         smcr_conn_save_peer_info(smc, clc);
     smc_conn_save_peer_info_fce(smc, clc);
 }
 
 static void smc_link_save_peer_info(struct smc_link *link,
                     struct smc_clc_msg_accept_confirm *clc,
                     struct smc_init_info *ini)
 {
     link->peer_qpn = ntoh24(clc->r0.qpn);
     memcpy(link->peer_gid, ini->peer_gid, SMC_GID_SIZE);
     memcpy(link->peer_mac, ini->peer_mac, sizeof(link->peer_mac));
     link->peer_psn = ntoh24(clc->r0.psn);
     link->peer_mtu = clc->r0.qp_mtu;
 }
 
 static void smc_stat_inc_fback_rsn_cnt(struct smc_sock *smc,
                        struct smc_stats_fback *fback_arr)
 {
     int cnt;
 
     for (cnt = 0; cnt < SMC_MAX_FBACK_RSN_CNT; cnt++) {
         if (fback_arr[cnt].fback_code == smc->fallback_rsn) {
             fback_arr[cnt].count++;
             break;
         }
         if (!fback_arr[cnt].fback_code) {
             fback_arr[cnt].fback_code = smc->fallback_rsn;
             fback_arr[cnt].count++;
             break;
         }
     }
 }
 
 static void smc_stat_fallback(struct smc_sock *smc)
 {
     struct net *net = sock_net(&smc->sk);
 
     mutex_lock(&net->smc.mutex_fback_rsn);
     if (smc->listen_smc) {
         smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->srv);
         net->smc.fback_rsn->srv_fback_cnt++;
     } else {
         smc_stat_inc_fback_rsn_cnt(smc, net->smc.fback_rsn->clnt);
         net->smc.fback_rsn->clnt_fback_cnt++;
     }
     mutex_unlock(&net->smc.mutex_fback_rsn);
 }
 
 /* must be called under rcu read lock */
 static void smc_fback_wakeup_waitqueue(struct smc_sock *smc, void *key)
 {
     struct socket_wq *wq;
     __poll_t flags;
 
     wq = rcu_dereference(smc->sk.sk_wq);
     if (!skwq_has_sleeper(wq))
         return;
 
     /* wake up smc sk->sk_wq */
     if (!key) {
         /* sk_state_change */
         wake_up_interruptible_all(&wq->wait);
     } else {
         flags = key_to_poll(key);
         if (flags & (EPOLLIN | EPOLLOUT))
             /* sk_data_ready or sk_write_space */
             wake_up_interruptible_sync_poll(&wq->wait, flags);
         else if (flags & EPOLLERR)
             /* sk_error_report */
             wake_up_interruptible_poll(&wq->wait, flags);
     }
 }
 
 static int smc_fback_mark_woken(wait_queue_entry_t *wait,
                 unsigned int mode, int sync, void *key)
 {
     struct smc_mark_woken *mark =
         container_of(wait, struct smc_mark_woken, wait_entry);
 
     mark->woken = true;
     mark->key = key;
     return 0;
 }
 
 static void smc_fback_forward_wakeup(struct smc_sock *smc, struct sock *clcsk,
                      void (*clcsock_callback)(struct sock *sk))
 {
     struct smc_mark_woken mark = { .woken = false };
     struct socket_wq *wq;
 
     init_waitqueue_func_entry(&mark.wait_entry,
                   smc_fback_mark_woken);
     rcu_read_lock();
     wq = rcu_dereference(clcsk->sk_wq);
     if (!wq)
         goto out;
     add_wait_queue(sk_sleep(clcsk), &mark.wait_entry);
     clcsock_callback(clcsk);
     remove_wait_queue(sk_sleep(clcsk), &mark.wait_entry);
 
     if (mark.woken)
         smc_fback_wakeup_waitqueue(smc, mark.key);
 out:
     rcu_read_unlock();
 }
 
 static void smc_fback_state_change(struct sock *clcsk)
 {
     struct smc_sock *smc;
 
     read_lock_bh(&clcsk->sk_callback_lock);
     smc = smc_clcsock_user_data(clcsk);
     if (smc)
         smc_fback_forward_wakeup(smc, clcsk,
                      smc->clcsk_state_change);
     read_unlock_bh(&clcsk->sk_callback_lock);
 }
 
 static void smc_fback_data_ready(struct sock *clcsk)
 {
     struct smc_sock *smc;
 
     read_lock_bh(&clcsk->sk_callback_lock);
     smc = smc_clcsock_user_data(clcsk);
     if (smc)
         smc_fback_forward_wakeup(smc, clcsk,
                      smc->clcsk_data_ready);
     read_unlock_bh(&clcsk->sk_callback_lock);
 }
 
 static void smc_fback_write_space(struct sock *clcsk)
 {
     struct smc_sock *smc;
 
     read_lock_bh(&clcsk->sk_callback_lock);
     smc = smc_clcsock_user_data(clcsk);
     if (smc)
         smc_fback_forward_wakeup(smc, clcsk,
                      smc->clcsk_write_space);
     read_unlock_bh(&clcsk->sk_callback_lock);
 }
 
 static void smc_fback_error_report(struct sock *clcsk)
 {
     struct smc_sock *smc;
 
     read_lock_bh(&clcsk->sk_callback_lock);
     smc = smc_clcsock_user_data(clcsk);
     if (smc)
         smc_fback_forward_wakeup(smc, clcsk,
                      smc->clcsk_error_report);
     read_unlock_bh(&clcsk->sk_callback_lock);
 }
 
 static void smc_fback_replace_callbacks(struct smc_sock *smc)
 {
     struct sock *clcsk = smc->clcsock->sk;
 
     write_lock_bh(&clcsk->sk_callback_lock);
     clcsk->sk_user_data = (void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
 
     smc_clcsock_replace_cb(&clcsk->sk_state_change, smc_fback_state_change,
                    &smc->clcsk_state_change);
     smc_clcsock_replace_cb(&clcsk->sk_data_ready, smc_fback_data_ready,
                    &smc->clcsk_data_ready);
     smc_clcsock_replace_cb(&clcsk->sk_write_space, smc_fback_write_space,
                    &smc->clcsk_write_space);
     smc_clcsock_replace_cb(&clcsk->sk_error_report, smc_fback_error_report,
                    &smc->clcsk_error_report);
 
     write_unlock_bh(&clcsk->sk_callback_lock);
 }
 
 static int smc_switch_to_fallback(struct smc_sock *smc, int reason_code)
 {
     int rc = 0;
 
     mutex_lock(&smc->clcsock_release_lock);
     if (!smc->clcsock) {
         rc = -EBADF;
         goto out;
     }
 
     smc->use_fallback = true;
     smc->fallback_rsn = reason_code;
     smc_stat_fallback(smc);
     trace_smc_switch_to_fallback(smc, reason_code);
     if (smc->sk.sk_socket && smc->sk.sk_socket->file) {
         smc->clcsock->file = smc->sk.sk_socket->file;
         smc->clcsock->file->private_data = smc->clcsock;
         smc->clcsock->wq.fasync_list =
             smc->sk.sk_socket->wq.fasync_list;
 
         /* There might be some wait entries remaining
          * in smc sk->sk_wq and they should be woken up
          * as clcsock's wait queue is woken up.
          */
         smc_fback_replace_callbacks(smc);
     }
 out:
     mutex_unlock(&smc->clcsock_release_lock);
     return rc;
 }
 
 /* fall back during connect */
 static int smc_connect_fallback(struct smc_sock *smc, int reason_code)
 {
     struct net *net = sock_net(&smc->sk);
     int rc = 0;
 
     rc = smc_switch_to_fallback(smc, reason_code);
     if (rc) { /* fallback fails */
         this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
         if (smc->sk.sk_state == SMC_INIT)
             sock_put(&smc->sk); /* passive closing */
         return rc;
     }
     smc_copy_sock_settings_to_clc(smc);
     smc->connect_nonblock = 0;
     if (smc->sk.sk_state == SMC_INIT)
         smc->sk.sk_state = SMC_ACTIVE;
     return 0;
 }
 
 /* decline and fall back during connect */
 static int smc_connect_decline_fallback(struct smc_sock *smc, int reason_code,
                     u8 version)
 {
     struct net *net = sock_net(&smc->sk);
     int rc;
 
     if (reason_code < 0) { /* error, fallback is not possible */
         this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
         if (smc->sk.sk_state == SMC_INIT)
             sock_put(&smc->sk); /* passive closing */
         return reason_code;
     }
     if (reason_code != SMC_CLC_DECL_PEERDECL) {
         rc = smc_clc_send_decline(smc, reason_code, version);
         if (rc < 0) {
             this_cpu_inc(net->smc.smc_stats->clnt_hshake_err_cnt);
             if (smc->sk.sk_state == SMC_INIT)
                 sock_put(&smc->sk); /* passive closing */
             return rc;
         }
     }
     return smc_connect_fallback(smc, reason_code);
 }
 
 static void smc_conn_abort(struct smc_sock *smc, int local_first)
 {
     struct smc_connection *conn = &smc->conn;
     struct smc_link_group *lgr = conn->lgr;
     bool lgr_valid = false;
 
     if (smc_conn_lgr_valid(conn))
         lgr_valid = true;
 
     smc_conn_free(conn);
     if (local_first && lgr_valid)
         smc_lgr_cleanup_early(lgr);
 }
 
 /* check if there is a rdma device available for this connection. */
 /* called for connect and listen */
 static int smc_find_rdma_device(struct smc_sock *smc, struct smc_init_info *ini)
 {
     /* PNET table look up: search active ib_device and port
      * within same PNETID that also contains the ethernet device
      * used for the internal TCP socket
      */
     smc_pnet_find_roce_resource(smc->clcsock->sk, ini);
     if (!ini->check_smcrv2 && !ini->ib_dev)
         return SMC_CLC_DECL_NOSMCRDEV;
     if (ini->check_smcrv2 && !ini->smcrv2.ib_dev_v2)
         return SMC_CLC_DECL_NOSMCRDEV;
     return 0;
 }
 
 /* check if there is an ISM device available for this connection. */
 /* called for connect and listen */
 static int smc_find_ism_device(struct smc_sock *smc, struct smc_init_info *ini)
 {
     /* Find ISM device with same PNETID as connecting interface  */
     smc_pnet_find_ism_resource(smc->clcsock->sk, ini);
     if (!ini->ism_dev[0])
         return SMC_CLC_DECL_NOSMCDDEV;
     else
         ini->ism_chid[0] = smc_ism_get_chid(ini->ism_dev[0]);
     return 0;
 }
 
 /* is chid unique for the ism devices that are already determined? */
 static bool smc_find_ism_v2_is_unique_chid(u16 chid, struct smc_init_info *ini,
                        int cnt)
 {
     int i = (!ini->ism_dev[0]) ? 1 : 0;
 
     for (; i < cnt; i++)
         if (ini->ism_chid[i] == chid)
             return false;
     return true;
 }
 
 /* determine possible V2 ISM devices (either without PNETID or with PNETID plus
  * PNETID matching net_device)
  */
 static int smc_find_ism_v2_device_clnt(struct smc_sock *smc,
                        struct smc_init_info *ini)
 {
     int rc = SMC_CLC_DECL_NOSMCDDEV;
     struct smcd_dev *smcd;
     int i = 1;
     u16 chid;
 
     if (smcd_indicated(ini->smc_type_v1))
         rc = 0;     /* already initialized for V1 */
     mutex_lock(&smcd_dev_list.mutex);
     list_for_each_entry(smcd, &smcd_dev_list.list, list) {
         if (smcd->going_away || smcd == ini->ism_dev[0])
             continue;
         chid = smc_ism_get_chid(smcd);
         if (!smc_find_ism_v2_is_unique_chid(chid, ini, i))
             continue;
         if (!smc_pnet_is_pnetid_set(smcd->pnetid) ||
             smc_pnet_is_ndev_pnetid(sock_net(&smc->sk), smcd->pnetid)) {
             ini->ism_dev[i] = smcd;
             ini->ism_chid[i] = chid;
             ini->is_smcd = true;
             rc = 0;
             i++;
             if (i > SMC_MAX_ISM_DEVS)
                 break;
         }
     }
     mutex_unlock(&smcd_dev_list.mutex);
     ini->ism_offered_cnt = i - 1;
     if (!ini->ism_dev[0] && !ini->ism_dev[1])
         ini->smcd_version = 0;
 
     return rc;
 }
 
 /* Check for VLAN ID and register it on ISM device just for CLC handshake */
 static int smc_connect_ism_vlan_setup(struct smc_sock *smc,
                       struct smc_init_info *ini)
 {
     if (ini->vlan_id && smc_ism_get_vlan(ini->ism_dev[0], ini->vlan_id))
         return SMC_CLC_DECL_ISMVLANERR;
     return 0;
 }
 
 static int smc_find_proposal_devices(struct smc_sock *smc,
                      struct smc_init_info *ini)
 {
     int rc = 0;
 
     /* check if there is an ism device available */
     if (!(ini->smcd_version & SMC_V1) ||
         smc_find_ism_device(smc, ini) ||
         smc_connect_ism_vlan_setup(smc, ini))
         ini->smcd_version &= ~SMC_V1;
     /* else ISM V1 is supported for this connection */
 
     /* check if there is an rdma device available */
     if (!(ini->smcr_version & SMC_V1) ||
         smc_find_rdma_device(smc, ini))
         ini->smcr_version &= ~SMC_V1;
     /* else RDMA is supported for this connection */
 
     ini->smc_type_v1 = smc_indicated_type(ini->smcd_version & SMC_V1,
                           ini->smcr_version & SMC_V1);
 
     /* check if there is an ism v2 device available */
     if (!(ini->smcd_version & SMC_V2) ||
         !smc_ism_is_v2_capable() ||
         smc_find_ism_v2_device_clnt(smc, ini))
         ini->smcd_version &= ~SMC_V2;
 
     /* check if there is an rdma v2 device available */
     ini->check_smcrv2 = true;
     ini->smcrv2.saddr = smc->clcsock->sk->sk_rcv_saddr;
     if (!(ini->smcr_version & SMC_V2) ||
         smc->clcsock->sk->sk_family != AF_INET ||
         !smc_clc_ueid_count() ||
         smc_find_rdma_device(smc, ini))
         ini->smcr_version &= ~SMC_V2;
     ini->check_smcrv2 = false;
 
     ini->smc_type_v2 = smc_indicated_type(ini->smcd_version & SMC_V2,
                           ini->smcr_version & SMC_V2);
 
     /* if neither ISM nor RDMA are supported, fallback */
     if (ini->smc_type_v1 == SMC_TYPE_N && ini->smc_type_v2 == SMC_TYPE_N)
         rc = SMC_CLC_DECL_NOSMCDEV;
 
     return rc;
 }
 
 /* cleanup temporary VLAN ID registration used for CLC handshake. If ISM is
  * used, the VLAN ID will be registered again during the connection setup.
  */
 static int smc_connect_ism_vlan_cleanup(struct smc_sock *smc,
                     struct smc_init_info *ini)
 {
     if (!smcd_indicated(ini->smc_type_v1))
         return 0;
     if (ini->vlan_id && smc_ism_put_vlan(ini->ism_dev[0], ini->vlan_id))
         return SMC_CLC_DECL_CNFERR;
     return 0;
 }
 
 #define SMC_CLC_MAX_ACCEPT_LEN \
     (sizeof(struct smc_clc_msg_accept_confirm_v2) + \
      sizeof(struct smc_clc_first_contact_ext) + \
      sizeof(struct smc_clc_msg_trail))
 
 /* CLC handshake during connect */
 static int smc_connect_clc(struct smc_sock *smc,
                struct smc_clc_msg_accept_confirm_v2 *aclc2,
                struct smc_init_info *ini)
 {
     int rc = 0;
 
     /* do inband token exchange */
     rc = smc_clc_send_proposal(smc, ini);
     if (rc)
         return rc;
     /* receive SMC Accept CLC message */
     return smc_clc_wait_msg(smc, aclc2, SMC_CLC_MAX_ACCEPT_LEN,
                 SMC_CLC_ACCEPT, CLC_WAIT_TIME);
 }
 
 void smc_fill_gid_list(struct smc_link_group *lgr,
                struct smc_gidlist *gidlist,
                struct smc_ib_device *known_dev, u8 *known_gid)
 {
     struct smc_init_info *alt_ini = NULL;
 
     memset(gidlist, 0, sizeof(*gidlist));
     memcpy(gidlist->list[gidlist->len++], known_gid, SMC_GID_SIZE);
 
     alt_ini = kzalloc(sizeof(*alt_ini), GFP_KERNEL);
     if (!alt_ini)
         goto out;
 
     alt_ini->vlan_id = lgr->vlan_id;
     alt_ini->check_smcrv2 = true;
     alt_ini->smcrv2.saddr = lgr->saddr;
     smc_pnet_find_alt_roce(lgr, alt_ini, known_dev);
 
     if (!alt_ini->smcrv2.ib_dev_v2)
         goto out;
 
     memcpy(gidlist->list[gidlist->len++], alt_ini->smcrv2.ib_gid_v2,
            SMC_GID_SIZE);
 
 out:
     kfree(alt_ini);
 }
 
 static int smc_connect_rdma_v2_prepare(struct smc_sock *smc,
                        struct smc_clc_msg_accept_confirm *aclc,
                        struct smc_init_info *ini)
 {
     struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
         (struct smc_clc_msg_accept_confirm_v2 *)aclc;
     struct smc_clc_first_contact_ext *fce =
         (struct smc_clc_first_contact_ext *)
             (((u8 *)clc_v2) + sizeof(*clc_v2));
 
     if (!ini->first_contact_peer || aclc->hdr.version == SMC_V1)
         return 0;
 
     if (fce->v2_direct) {
         memcpy(ini->smcrv2.nexthop_mac, &aclc->r0.lcl.mac, ETH_ALEN);
         ini->smcrv2.uses_gateway = false;
     } else {
         if (smc_ib_find_route(smc->clcsock->sk->sk_rcv_saddr,
                       smc_ib_gid_to_ipv4(aclc->r0.lcl.gid),
                       ini->smcrv2.nexthop_mac,
                       &ini->smcrv2.uses_gateway))
             return SMC_CLC_DECL_NOROUTE;
         if (!ini->smcrv2.uses_gateway) {
             /* mismatch: peer claims indirect, but its direct */
             return SMC_CLC_DECL_NOINDIRECT;
         }
     }
     return 0;
 }
 
 /* setup for RDMA connection of client */
 static int smc_connect_rdma(struct smc_sock *smc,
                 struct smc_clc_msg_accept_confirm *aclc,
                 struct smc_init_info *ini)
 {
     int i, reason_code = 0;
     struct smc_link *link;
     u8 *eid = NULL;
 
     ini->is_smcd = false;
     ini->ib_clcqpn = ntoh24(aclc->r0.qpn);
     ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
     memcpy(ini->peer_systemid, aclc->r0.lcl.id_for_peer, SMC_SYSTEMID_LEN);
     memcpy(ini->peer_gid, aclc->r0.lcl.gid, SMC_GID_SIZE);
     memcpy(ini->peer_mac, aclc->r0.lcl.mac, ETH_ALEN);
 
     reason_code = smc_connect_rdma_v2_prepare(smc, aclc, ini);
     if (reason_code)
         return reason_code;
 
     mutex_lock(&smc_client_lgr_pending);
     reason_code = smc_conn_create(smc, ini);
     if (reason_code) {
         mutex_unlock(&smc_client_lgr_pending);
         return reason_code;
     }
 
     smc_conn_save_peer_info(smc, aclc);
 
     if (ini->first_contact_local) {
         link = smc->conn.lnk;
     } else {
         /* set link that was assigned by server */
         link = NULL;
         for (i = 0; i < SMC_LINKS_PER_LGR_MAX; i++) {
             struct smc_link *l = &smc->conn.lgr->lnk[i];
 
             if (l->peer_qpn == ntoh24(aclc->r0.qpn) &&
                 !memcmp(l->peer_gid, &aclc->r0.lcl.gid,
                     SMC_GID_SIZE) &&
                 (aclc->hdr.version > SMC_V1 ||
                  !memcmp(l->peer_mac, &aclc->r0.lcl.mac,
                      sizeof(l->peer_mac)))) {
                 link = l;
                 break;
             }
         }
         if (!link) {
             reason_code = SMC_CLC_DECL_NOSRVLINK;
             goto connect_abort;
         }
         smc_switch_link_and_count(&smc->conn, link);
     }
 
     /* create send buffer and rmb */
     if (smc_buf_create(smc, false)) {
         reason_code = SMC_CLC_DECL_MEM;
         goto connect_abort;
     }
 
     if (ini->first_contact_local)
         smc_link_save_peer_info(link, aclc, ini);
 
     if (smc_rmb_rtoken_handling(&smc->conn, link, aclc)) {
         reason_code = SMC_CLC_DECL_ERR_RTOK;
         goto connect_abort;
     }
 
     smc_close_init(smc);
     smc_rx_init(smc);
 
     if (ini->first_contact_local) {
         if (smc_ib_ready_link(link)) {
             reason_code = SMC_CLC_DECL_ERR_RDYLNK;
             goto connect_abort;
         }
     } else {
         /* reg sendbufs if they were vzalloced */
         if (smc->conn.sndbuf_desc->is_vm) {
             if (smcr_lgr_reg_sndbufs(link, smc->conn.sndbuf_desc)) {
                 reason_code = SMC_CLC_DECL_ERR_REGBUF;
                 goto connect_abort;
             }
         }
         if (smcr_lgr_reg_rmbs(link, smc->conn.rmb_desc)) {
             reason_code = SMC_CLC_DECL_ERR_REGBUF;
             goto connect_abort;
         }
     }
 
     if (aclc->hdr.version > SMC_V1) {
         struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
             (struct smc_clc_msg_accept_confirm_v2 *)aclc;
 
         eid = clc_v2->r1.eid;
         if (ini->first_contact_local)
             smc_fill_gid_list(link->lgr, &ini->smcrv2.gidlist,
                       link->smcibdev, link->gid);
     }
 
     reason_code = smc_clc_send_confirm(smc, ini->first_contact_local,
                        aclc->hdr.version, eid, ini);
     if (reason_code)
         goto connect_abort;
 
     smc_tx_init(smc);
 
     if (ini->first_contact_local) {
         /* QP confirmation over RoCE fabric */
         smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
         reason_code = smcr_clnt_conf_first_link(smc);
         smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
         if (reason_code)
             goto connect_abort;
     }
     mutex_unlock(&smc_client_lgr_pending);
 
     smc_copy_sock_settings_to_clc(smc);
     smc->connect_nonblock = 0;
     if (smc->sk.sk_state == SMC_INIT)
         smc->sk.sk_state = SMC_ACTIVE;
 
     return 0;
 connect_abort:
     smc_conn_abort(smc, ini->first_contact_local);
     mutex_unlock(&smc_client_lgr_pending);
     smc->connect_nonblock = 0;
 
     return reason_code;
 }
 
 /* The server has chosen one of the proposed ISM devices for the communication.
  * Determine from the CHID of the received CLC ACCEPT the ISM device chosen.
  */
 static int
 smc_v2_determine_accepted_chid(struct smc_clc_msg_accept_confirm_v2 *aclc,
                    struct smc_init_info *ini)
 {
     int i;
 
     for (i = 0; i < ini->ism_offered_cnt + 1; i++) {
         if (ini->ism_chid[i] == ntohs(aclc->d1.chid)) {
             ini->ism_selected = i;
             return 0;
         }
     }
 
     return -EPROTO;
 }
 
 /* setup for ISM connection of client */
 static int smc_connect_ism(struct smc_sock *smc,
                struct smc_clc_msg_accept_confirm *aclc,
                struct smc_init_info *ini)
 {
     u8 *eid = NULL;
     int rc = 0;
 
     ini->is_smcd = true;
     ini->first_contact_peer = aclc->hdr.typev2 & SMC_FIRST_CONTACT_MASK;
 
     if (aclc->hdr.version == SMC_V2) {
         struct smc_clc_msg_accept_confirm_v2 *aclc_v2 =
             (struct smc_clc_msg_accept_confirm_v2 *)aclc;
 
         rc = smc_v2_determine_accepted_chid(aclc_v2, ini);
         if (rc)
             return rc;
     }
     ini->ism_peer_gid[ini->ism_selected] = aclc->d0.gid;
 
     /* there is only one lgr role for SMC-D; use server lock */
     mutex_lock(&smc_server_lgr_pending);
     rc = smc_conn_create(smc, ini);
     if (rc) {
         mutex_unlock(&smc_server_lgr_pending);
         return rc;
     }
 
     /* Create send and receive buffers */
     rc = smc_buf_create(smc, true);
     if (rc) {
         rc = (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB : SMC_CLC_DECL_MEM;
         goto connect_abort;
     }
 
     smc_conn_save_peer_info(smc, aclc);
     smc_close_init(smc);
     smc_rx_init(smc);
     smc_tx_init(smc);
 
     if (aclc->hdr.version > SMC_V1) {
         struct smc_clc_msg_accept_confirm_v2 *clc_v2 =
             (struct smc_clc_msg_accept_confirm_v2 *)aclc;
 
         eid = clc_v2->d1.eid;
     }
 
     rc = smc_clc_send_confirm(smc, ini->first_contact_local,
                   aclc->hdr.version, eid, NULL);
     if (rc)
         goto connect_abort;
     mutex_unlock(&smc_server_lgr_pending);
 
     smc_copy_sock_settings_to_clc(smc);
     smc->connect_nonblock = 0;
     if (smc->sk.sk_state == SMC_INIT)
         smc->sk.sk_state = SMC_ACTIVE;
 
     return 0;
 connect_abort:
     smc_conn_abort(smc, ini->first_contact_local);
     mutex_unlock(&smc_server_lgr_pending);
     smc->connect_nonblock = 0;
 
     return rc;
 }
 
 /* check if received accept type and version matches a proposed one */
 static int smc_connect_check_aclc(struct smc_init_info *ini,
                   struct smc_clc_msg_accept_confirm *aclc)
 {
     if (aclc->hdr.typev1 != SMC_TYPE_R &&
         aclc->hdr.typev1 != SMC_TYPE_D)
         return SMC_CLC_DECL_MODEUNSUPP;
 
     if (aclc->hdr.version >= SMC_V2) {
         if ((aclc->hdr.typev1 == SMC_TYPE_R &&
              !smcr_indicated(ini->smc_type_v2)) ||
             (aclc->hdr.typev1 == SMC_TYPE_D &&
              !smcd_indicated(ini->smc_type_v2)))
             return SMC_CLC_DECL_MODEUNSUPP;
     } else {
         if ((aclc->hdr.typev1 == SMC_TYPE_R &&
              !smcr_indicated(ini->smc_type_v1)) ||
             (aclc->hdr.typev1 == SMC_TYPE_D &&
              !smcd_indicated(ini->smc_type_v1)))
             return SMC_CLC_DECL_MODEUNSUPP;
     }
 
     return 0;
 }
 
 /* perform steps before actually connecting */
 static int __smc_connect(struct smc_sock *smc)
 {
     u8 version = smc_ism_is_v2_capable() ? SMC_V2 : SMC_V1;
     struct smc_clc_msg_accept_confirm_v2 *aclc2;
     struct smc_clc_msg_accept_confirm *aclc;
     struct smc_init_info *ini = NULL;
     u8 *buf = NULL;
     int rc = 0;
 
     if (smc->use_fallback)
         return smc_connect_fallback(smc, smc->fallback_rsn);
 
     /* if peer has not signalled SMC-capability, fall back */
     if (!tcp_sk(smc->clcsock->sk)->syn_smc)
         return smc_connect_fallback(smc, SMC_CLC_DECL_PEERNOSMC);
 
     /* IPSec connections opt out of SMC optimizations */
     if (using_ipsec(smc))
         return smc_connect_decline_fallback(smc, SMC_CLC_DECL_IPSEC,
                             version);
 
     ini = kzalloc(sizeof(*ini), GFP_KERNEL);
     if (!ini)
         return smc_connect_decline_fallback(smc, SMC_CLC_DECL_MEM,
                             version);
 
     ini->smcd_version = SMC_V1 | SMC_V2;
     ini->smcr_version = SMC_V1 | SMC_V2;
     ini->smc_type_v1 = SMC_TYPE_B;
     ini->smc_type_v2 = SMC_TYPE_B;
 
     /* get vlan id from IP device */
     if (smc_vlan_by_tcpsk(smc->clcsock, ini)) {
         ini->smcd_version &= ~SMC_V1;
         ini->smcr_version = 0;
         ini->smc_type_v1 = SMC_TYPE_N;
         if (!ini->smcd_version) {
             rc = SMC_CLC_DECL_GETVLANERR;
             goto fallback;
         }
     }
 
     rc = smc_find_proposal_devices(smc, ini);
     if (rc)
         goto fallback;
 
     buf = kzalloc(SMC_CLC_MAX_ACCEPT_LEN, GFP_KERNEL);
     if (!buf) {
         rc = SMC_CLC_DECL_MEM;
         goto fallback;
     }
     aclc2 = (struct smc_clc_msg_accept_confirm_v2 *)buf;
     aclc = (struct smc_clc_msg_accept_confirm *)aclc2;
 
     /* perform CLC handshake */
     rc = smc_connect_clc(smc, aclc2, ini);
     if (rc) {
         /* -EAGAIN on timeout, see tcp_recvmsg() */
         if (rc == -EAGAIN) {
             rc = -ETIMEDOUT;
             smc->sk.sk_err = ETIMEDOUT;
         }
         goto vlan_cleanup;
     }
 
     /* check if smc modes and versions of CLC proposal and accept match */
     rc = smc_connect_check_aclc(ini, aclc);
     version = aclc->hdr.version == SMC_V1 ? SMC_V1 : SMC_V2;
     if (rc)
         goto vlan_cleanup;
 
     /* depending on previous steps, connect using rdma or ism */
     if (aclc->hdr.typev1 == SMC_TYPE_R) {
         ini->smcr_version = version;
         rc = smc_connect_rdma(smc, aclc, ini);
     } else if (aclc->hdr.typev1 == SMC_TYPE_D) {
         ini->smcd_version = version;
         rc = smc_connect_ism(smc, aclc, ini);
     }
     if (rc)
         goto vlan_cleanup;
 
     SMC_STAT_CLNT_SUCC_INC(sock_net(smc->clcsock->sk), aclc);
     smc_connect_ism_vlan_cleanup(smc, ini);
     kfree(buf);
     kfree(ini);
     return 0;
 
 vlan_cleanup:
     smc_connect_ism_vlan_cleanup(smc, ini);
     kfree(buf);
 fallback:
     kfree(ini);
     return smc_connect_decline_fallback(smc, rc, version);
 }
 
 static void smc_connect_work(struct work_struct *work)
 {
     struct smc_sock *smc = container_of(work, struct smc_sock,
                         connect_work);
     long timeo = smc->sk.sk_sndtimeo;
     int rc = 0;
 
     if (!timeo)
         timeo = MAX_SCHEDULE_TIMEOUT;
     lock_sock(smc->clcsock->sk);
     if (smc->clcsock->sk->sk_err) {
         smc->sk.sk_err = smc->clcsock->sk->sk_err;
     } else if ((1 << smc->clcsock->sk->sk_state) &
                     (TCPF_SYN_SENT | TCPF_SYN_RECV)) {
         rc = sk_stream_wait_connect(smc->clcsock->sk, &timeo);
         if ((rc == -EPIPE) &&
             ((1 << smc->clcsock->sk->sk_state) &
                     (TCPF_ESTABLISHED | TCPF_CLOSE_WAIT)))
             rc = 0;
     }
     release_sock(smc->clcsock->sk);
     lock_sock(&smc->sk);
     if (rc != 0 || smc->sk.sk_err) {
         smc->sk.sk_state = SMC_CLOSED;
         if (rc == -EPIPE || rc == -EAGAIN)
             smc->sk.sk_err = EPIPE;
         else if (rc == -ECONNREFUSED)
             smc->sk.sk_err = ECONNREFUSED;
         else if (signal_pending(current))
             smc->sk.sk_err = -sock_intr_errno(timeo);
         sock_put(&smc->sk); /* passive closing */
         goto out;
     }
 
     rc = __smc_connect(smc);
     if (rc < 0)
         smc->sk.sk_err = -rc;
 
 out:
     if (!sock_flag(&smc->sk, SOCK_DEAD)) {
         if (smc->sk.sk_err) {
             smc->sk.sk_state_change(&smc->sk);
         } else { /* allow polling before and after fallback decision */
             smc->clcsock->sk->sk_write_space(smc->clcsock->sk);
             smc->sk.sk_write_space(&smc->sk);
         }
     }
     release_sock(&smc->sk);
 }
 
 static int smc_connect(struct socket *sock, struct sockaddr *addr,
                int alen, int flags)
 {
     struct sock *sk = sock->sk;
     struct smc_sock *smc;
     int rc = -EINVAL;
 
     smc = smc_sk(sk);
 
     /* separate smc parameter checking to be safe */
     if (alen < sizeof(addr->sa_family))
         goto out_err;
     if (addr->sa_family != AF_INET && addr->sa_family != AF_INET6)
         goto out_err;
 
     lock_sock(sk);
     switch (sock->state) {
     default:
         rc = -EINVAL;
         goto out;
     case SS_CONNECTED:
         rc = sk->sk_state == SMC_ACTIVE ? -EISCONN : -EINVAL;
         goto out;
     case SS_CONNECTING:
         if (sk->sk_state == SMC_ACTIVE)
             goto connected;
         break;
     case SS_UNCONNECTED:
         sock->state = SS_CONNECTING;
         break;
     }
 
     switch (sk->sk_state) {
     default:
         goto out;
     case SMC_CLOSED:
         rc = sock_error(sk) ? : -ECONNABORTED;
         sock->state = SS_UNCONNECTED;
         goto out;
     case SMC_ACTIVE:
         rc = -EISCONN;
         goto out;
     case SMC_INIT:
         break;
     }
 
     smc_copy_sock_settings_to_clc(smc);
     tcp_sk(smc->clcsock->sk)->syn_smc = 1;
     if (smc->connect_nonblock) {
         rc = -EALREADY;
         goto out;
     }
     rc = kernel_connect(smc->clcsock, addr, alen, flags);
     if (rc && rc != -EINPROGRESS)
         goto out;
 
     if (smc->use_fallback) {
         sock->state = rc ? SS_CONNECTING : SS_CONNECTED;
         goto out;
     }
     sock_hold(&smc->sk); /* sock put in passive closing */
     if (flags & O_NONBLOCK) {
         if (queue_work(smc_hs_wq, &smc->connect_work))
             smc->connect_nonblock = 1;
         rc = -EINPROGRESS;
         goto out;
     } else {
         rc = __smc_connect(smc);
         if (rc < 0)
             goto out;
     }
 
 connected:
     rc = 0;
     sock->state = SS_CONNECTED;
 out:
     release_sock(sk);
 out_err:
     return rc;
 }
 
 static int smc_clcsock_accept(struct smc_sock *lsmc, struct smc_sock **new_smc)
 {
     struct socket *new_clcsock = NULL;
     struct sock *lsk = &lsmc->sk;
     struct sock *new_sk;
     int rc = -EINVAL;
 
     release_sock(lsk);
     new_sk = smc_sock_alloc(sock_net(lsk), NULL, lsk->sk_protocol);
     if (!new_sk) {
         rc = -ENOMEM;
         lsk->sk_err = ENOMEM;
         *new_smc = NULL;
         lock_sock(lsk);
         goto out;
     }
     *new_smc = smc_sk(new_sk);
 
     mutex_lock(&lsmc->clcsock_release_lock);
     if (lsmc->clcsock)
         rc = kernel_accept(lsmc->clcsock, &new_clcsock, SOCK_NONBLOCK);
     mutex_unlock(&lsmc->clcsock_release_lock);
     lock_sock(lsk);
     if  (rc < 0 && rc != -EAGAIN)
         lsk->sk_err = -rc;
     if (rc < 0 || lsk->sk_state == SMC_CLOSED) {
         new_sk->sk_prot->unhash(new_sk);
         if (new_clcsock)
             sock_release(new_clcsock);
         new_sk->sk_state = SMC_CLOSED;
         sock_set_flag(new_sk, SOCK_DEAD);
         sock_put(new_sk); /* final */
         *new_smc = NULL;
         goto out;
     }
 
     /* new clcsock has inherited the smc listen-specific sk_data_ready
      * function; switch it back to the original sk_data_ready function
      */
     new_clcsock->sk->sk_data_ready = lsmc->clcsk_data_ready;
 
     /* if new clcsock has also inherited the fallback-specific callback
      * functions, switch them back to the original ones.
      */
     if (lsmc->use_fallback) {
         if (lsmc->clcsk_state_change)
             new_clcsock->sk->sk_state_change = lsmc->clcsk_state_change;
         if (lsmc->clcsk_write_space)
             new_clcsock->sk->sk_write_space = lsmc->clcsk_write_space;
         if (lsmc->clcsk_error_report)
             new_clcsock->sk->sk_error_report = lsmc->clcsk_error_report;
     }
 
     (*new_smc)->clcsock = new_clcsock;
 out:
     return rc;
 }
 
 /* add a just created sock to the accept queue of the listen sock as
  * candidate for a following socket accept call from user space
  */
 static void smc_accept_enqueue(struct sock *parent, struct sock *sk)
 {
     struct smc_sock *par = smc_sk(parent);
 
     sock_hold(sk); /* sock_put in smc_accept_unlink () */
     spin_lock(&par->accept_q_lock);
     list_add_tail(&smc_sk(sk)->accept_q, &par->accept_q);
     spin_unlock(&par->accept_q_lock);
     sk_acceptq_added(parent);
 }
 
 /* remove a socket from the accept queue of its parental listening socket */
 static void smc_accept_unlink(struct sock *sk)
 {
     struct smc_sock *par = smc_sk(sk)->listen_smc;
 
     spin_lock(&par->accept_q_lock);
     list_del_init(&smc_sk(sk)->accept_q);
     spin_unlock(&par->accept_q_lock);
     sk_acceptq_removed(&smc_sk(sk)->listen_smc->sk);
     sock_put(sk); /* sock_hold in smc_accept_enqueue */
 }
 
 /* remove a sock from the accept queue to bind it to a new socket created
  * for a socket accept call from user space
  */
 struct sock *smc_accept_dequeue(struct sock *parent,
                 struct socket *new_sock)
 {
     struct smc_sock *isk, *n;
     struct sock *new_sk;
 
     list_for_each_entry_safe(isk, n, &smc_sk(parent)->accept_q, accept_q) {
         new_sk = (struct sock *)isk;
 
         smc_accept_unlink(new_sk);
         if (new_sk->sk_state == SMC_CLOSED) {
             new_sk->sk_prot->unhash(new_sk);
             if (isk->clcsock) {
                 sock_release(isk->clcsock);
                 isk->clcsock = NULL;
             }
             sock_put(new_sk); /* final */
             continue;
         }
         if (new_sock) {
             sock_graft(new_sk, new_sock);
             new_sock->state = SS_CONNECTED;
             if (isk->use_fallback) {
                 smc_sk(new_sk)->clcsock->file = new_sock->file;
                 isk->clcsock->file->private_data = isk->clcsock;
             }
         }
         return new_sk;
     }
     return NULL;
 }
 
 /* clean up for a created but never accepted sock */
 void smc_close_non_accepted(struct sock *sk)
 {
     struct smc_sock *smc = smc_sk(sk);
 
     sock_hold(sk); /* sock_put below */
     lock_sock(sk);
     if (!sk->sk_lingertime)
         /* wait for peer closing */
         sk->sk_lingertime = SMC_MAX_STREAM_WAIT_TIMEOUT;
     __smc_release(smc);
     release_sock(sk);
     sock_put(sk); /* sock_hold above */
     sock_put(sk); /* final sock_put */
 }
 
 static int smcr_serv_conf_first_link(struct smc_sock *smc)
 {
     struct smc_link *link = smc->conn.lnk;
     struct smc_llc_qentry *qentry;
     int rc;
 
     /* reg the sndbuf if it was vzalloced*/
     if (smc->conn.sndbuf_desc->is_vm) {
         if (smcr_link_reg_buf(link, smc->conn.sndbuf_desc))
             return SMC_CLC_DECL_ERR_REGBUF;
     }
 
     /* reg the rmb */
     if (smcr_link_reg_buf(link, smc->conn.rmb_desc))
         return SMC_CLC_DECL_ERR_REGBUF;
 
     /* send CONFIRM LINK request to client over the RoCE fabric */
     rc = smc_llc_send_confirm_link(link, SMC_LLC_REQ);
     if (rc < 0)
         return SMC_CLC_DECL_TIMEOUT_CL;
 
     /* receive CONFIRM LINK response from client over the RoCE fabric */
     qentry = smc_llc_wait(link->lgr, link, SMC_LLC_WAIT_TIME,
                   SMC_LLC_CONFIRM_LINK);
     if (!qentry) {
         struct smc_clc_msg_decline dclc;
 
         rc = smc_clc_wait_msg(smc, &dclc, sizeof(dclc),
                       SMC_CLC_DECLINE, CLC_WAIT_TIME_SHORT);
         return rc == -EAGAIN ? SMC_CLC_DECL_TIMEOUT_CL : rc;
     }
     smc_llc_save_peer_uid(qentry);
     rc = smc_llc_eval_conf_link(qentry, SMC_LLC_RESP);
     smc_llc_flow_qentry_del(&link->lgr->llc_flow_lcl);
     if (rc)
         return SMC_CLC_DECL_RMBE_EC;
 
     /* confirm_rkey is implicit on 1st contact */
     smc->conn.rmb_desc->is_conf_rkey = true;
 
     smc_llc_link_active(link);
     smcr_lgr_set_type(link->lgr, SMC_LGR_SINGLE);
 
     /* initial contact - try to establish second link */
     smc_llc_srv_add_link(link, NULL);
     return 0;
 }
 
 /* listen worker: finish */
 static void smc_listen_out(struct smc_sock *new_smc)
 {
     struct smc_sock *lsmc = new_smc->listen_smc;
     struct sock *newsmcsk = &new_smc->sk;
 
     if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
         atomic_dec(&lsmc->queued_smc_hs);
 
     if (lsmc->sk.sk_state == SMC_LISTEN) {
         lock_sock_nested(&lsmc->sk, SINGLE_DEPTH_NESTING);
         smc_accept_enqueue(&lsmc->sk, newsmcsk);
         release_sock(&lsmc->sk);
     } else { /* no longer listening */
         smc_close_non_accepted(newsmcsk);
     }
 
     /* Wake up accept */
     lsmc->sk.sk_data_ready(&lsmc->sk);
     sock_put(&lsmc->sk); /* sock_hold in smc_tcp_listen_work */
 }
 
 /* listen worker: finish in state connected */
 static void smc_listen_out_connected(struct smc_sock *new_smc)
 {
     struct sock *newsmcsk = &new_smc->sk;
 
     if (newsmcsk->sk_state == SMC_INIT)
         newsmcsk->sk_state = SMC_ACTIVE;
 
     smc_listen_out(new_smc);
 }
 
 /* listen worker: finish in error state */
 static void smc_listen_out_err(struct smc_sock *new_smc)
 {
     struct sock *newsmcsk = &new_smc->sk;
     struct net *net = sock_net(newsmcsk);
 
     this_cpu_inc(net->smc.smc_stats->srv_hshake_err_cnt);
     if (newsmcsk->sk_state == SMC_INIT)
         sock_put(&new_smc->sk); /* passive closing */
     newsmcsk->sk_state = SMC_CLOSED;
 
     smc_listen_out(new_smc);
 }
 
 /* listen worker: decline and fall back if possible */
 static void smc_listen_decline(struct smc_sock *new_smc, int reason_code,
                    int local_first, u8 version)
 {
     /* RDMA setup failed, switch back to TCP */
     smc_conn_abort(new_smc, local_first);
     if (reason_code < 0 ||
         smc_switch_to_fallback(new_smc, reason_code)) {
         /* error, no fallback possible */
         smc_listen_out_err(new_smc);
         return;
     }
     if (reason_code && reason_code != SMC_CLC_DECL_PEERDECL) {
         if (smc_clc_send_decline(new_smc, reason_code, version) < 0) {
             smc_listen_out_err(new_smc);
             return;
         }
     }
     smc_listen_out_connected(new_smc);
 }
 
 /* listen worker: version checking */
 static int smc_listen_v2_check(struct smc_sock *new_smc,
                    struct smc_clc_msg_proposal *pclc,
                    struct smc_init_info *ini)
 {
     struct smc_clc_smcd_v2_extension *pclc_smcd_v2_ext;
     struct smc_clc_v2_extension *pclc_v2_ext;
     int rc = SMC_CLC_DECL_PEERNOSMC;
 
     ini->smc_type_v1 = pclc->hdr.typev1;
     ini->smc_type_v2 = pclc->hdr.typev2;
     ini->smcd_version = smcd_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
     ini->smcr_version = smcr_indicated(ini->smc_type_v1) ? SMC_V1 : 0;
     if (pclc->hdr.version > SMC_V1) {
         if (smcd_indicated(ini->smc_type_v2))
             ini->smcd_version |= SMC_V2;
         if (smcr_indicated(ini->smc_type_v2))
             ini->smcr_version |= SMC_V2;
     }
     if (!(ini->smcd_version & SMC_V2) && !(ini->smcr_version & SMC_V2)) {
         rc = SMC_CLC_DECL_PEERNOSMC;
         goto out;
     }
     pclc_v2_ext = smc_get_clc_v2_ext(pclc);
     if (!pclc_v2_ext) {
         ini->smcd_version &= ~SMC_V2;
         ini->smcr_version &= ~SMC_V2;
         rc = SMC_CLC_DECL_NOV2EXT;
         goto out;
     }
     pclc_smcd_v2_ext = smc_get_clc_smcd_v2_ext(pclc_v2_ext);
     if (ini->smcd_version & SMC_V2) {
         if (!smc_ism_is_v2_capable()) {
             ini->smcd_version &= ~SMC_V2;
             rc = SMC_CLC_DECL_NOISM2SUPP;
         } else if (!pclc_smcd_v2_ext) {
             ini->smcd_version &= ~SMC_V2;
             rc = SMC_CLC_DECL_NOV2DEXT;
         } else if (!pclc_v2_ext->hdr.eid_cnt &&
                !pclc_v2_ext->hdr.flag.seid) {
             ini->smcd_version &= ~SMC_V2;
             rc = SMC_CLC_DECL_NOUEID;
         }
     }
     if (ini->smcr_version & SMC_V2) {
         if (!pclc_v2_ext->hdr.eid_cnt) {
             ini->smcr_version &= ~SMC_V2;
             rc = SMC_CLC_DECL_NOUEID;
         }
     }
 
 out:
     if (!ini->smcd_version && !ini->smcr_version)
         return rc;
 
     return 0;
 }
 
 /* listen worker: check prefixes */
 static int smc_listen_prfx_check(struct smc_sock *new_smc,
                  struct smc_clc_msg_proposal *pclc)
 {
     struct smc_clc_msg_proposal_prefix *pclc_prfx;
     struct socket *newclcsock = new_smc->clcsock;
 
     if (pclc->hdr.typev1 == SMC_TYPE_N)
         return 0;
     pclc_prfx = smc_clc_proposal_get_prefix(pclc);
     if (smc_clc_prfx_match(newclcsock, pclc_prfx))
         return SMC_CLC_DECL_DIFFPREFIX;
 
     return 0;
 }
 
 /* listen worker: initialize connection and buffers */
 static int smc_listen_rdma_init(struct smc_sock *new_smc,
                 struct smc_init_info *ini)
 {
     int rc;
 
     /* allocate connection / link group */
     rc = smc_conn_create(new_smc, ini);
     if (rc)
         return rc;
 
     /* create send buffer and rmb */
     if (smc_buf_create(new_smc, false))
         return SMC_CLC_DECL_MEM;
 
     return 0;
 }
 
 /* listen worker: initialize connection and buffers for SMC-D */
 static int smc_listen_ism_init(struct smc_sock *new_smc,
                    struct smc_init_info *ini)
 {
     int rc;
 
     rc = smc_conn_create(new_smc, ini);
     if (rc)
         return rc;
 
     /* Create send and receive buffers */
     rc = smc_buf_create(new_smc, true);
     if (rc) {
         smc_conn_abort(new_smc, ini->first_contact_local);
         return (rc == -ENOSPC) ? SMC_CLC_DECL_MAX_DMB :
                      SMC_CLC_DECL_MEM;
     }
 
     return 0;
 }
 
 static bool smc_is_already_selected(struct smcd_dev *smcd,
                     struct smc_init_info *ini,
                     int matches)
 {
     int i;
 
     for (i = 0; i < matches; i++)
         if (smcd == ini->ism_dev[i])
             return true;
 
     return false;
 }
 
 /* check for ISM devices matching proposed ISM devices */
 static void smc_check_ism_v2_match(struct smc_init_info *ini,
                    u16 proposed_chid, u64 proposed_gid,
                    unsigned int *matches)
 {
     struct smcd_dev *smcd;
 
     list_for_each_entry(smcd, &smcd_dev_list.list, list) {
         if (smcd->going_away)
             continue;
         if (smc_is_already_selected(smcd, ini, *matches))
             continue;
         if (smc_ism_get_chid(smcd) == proposed_chid &&
             !smc_ism_cantalk(proposed_gid, ISM_RESERVED_VLANID, smcd)) {
             ini->ism_peer_gid[*matches] = proposed_gid;
             ini->ism_dev[*matches] = smcd;
             (*matches)++;
             break;
         }
     }
 }
 
 static void smc_find_ism_store_rc(u32 rc, struct smc_init_info *ini)
 {
     if (!ini->rc)
         ini->rc = rc;
 }
 
 static void smc_find_ism_v2_device_serv(struct smc_sock *new_smc,
                     struct smc_clc_msg_proposal *pclc,
                     struct smc_init_info *ini)
 {
     struct smc_clc_smcd_v2_extension *smcd_v2_ext;
     struct smc_clc_v2_extension *smc_v2_ext;
     struct smc_clc_msg_smcd *pclc_smcd;
     unsigned int matches = 0;
     u8 smcd_version;
     u8 *eid = NULL;
     int i, rc;
 
     if (!(ini->smcd_version & SMC_V2) || !smcd_indicated(ini->smc_type_v2))
         goto not_found;
 
     pclc_smcd = smc_get_clc_msg_smcd(pclc);
     smc_v2_ext = smc_get_clc_v2_ext(pclc);
     smcd_v2_ext = smc_get_clc_smcd_v2_ext(smc_v2_ext);
 
     mutex_lock(&smcd_dev_list.mutex);
     if (pclc_smcd->ism.chid)
         /* check for ISM device matching proposed native ISM device */
         smc_check_ism_v2_match(ini, ntohs(pclc_smcd->ism.chid),
                        ntohll(pclc_smcd->ism.gid), &matches);
     for (i = 1; i <= smc_v2_ext->hdr.ism_gid_cnt; i++) {
         /* check for ISM devices matching proposed non-native ISM
          * devices
          */
         smc_check_ism_v2_match(ini,
                        ntohs(smcd_v2_ext->gidchid[i - 1].chid),
                        ntohll(smcd_v2_ext->gidchid[i - 1].gid),
                        &matches);
     }
     mutex_unlock(&smcd_dev_list.mutex);
 
     if (!ini->ism_dev[0]) {
         smc_find_ism_store_rc(SMC_CLC_DECL_NOSMCD2DEV, ini);
         goto not_found;
     }
 
     smc_ism_get_system_eid(&eid);
     if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext,
                    smcd_v2_ext->system_eid, eid))
         goto not_found;
 
     /* separate - outside the smcd_dev_list.lock */
     smcd_version = ini->smcd_version;
     for (i = 0; i < matches; i++) {
         ini->smcd_version = SMC_V2;
         ini->is_smcd = true;
         ini->ism_selected = i;
         rc = smc_listen_ism_init(new_smc, ini);
         if (rc) {
             smc_find_ism_store_rc(rc, ini);
             /* try next active ISM device */
             continue;
         }
         return; /* matching and usable V2 ISM device found */
     }
     /* no V2 ISM device could be initialized */
     ini->smcd_version = smcd_version;   /* restore original value */
     ini->negotiated_eid[0] = 0;
 
 not_found:
     ini->smcd_version &= ~SMC_V2;
     ini->ism_dev[0] = NULL;
     ini->is_smcd = false;
 }
 
 static void smc_find_ism_v1_device_serv(struct smc_sock *new_smc,
                     struct smc_clc_msg_proposal *pclc,
                     struct smc_init_info *ini)
 {
     struct smc_clc_msg_smcd *pclc_smcd = smc_get_clc_msg_smcd(pclc);
     int rc = 0;
 
     /* check if ISM V1 is available */
     if (!(ini->smcd_version & SMC_V1) || !smcd_indicated(ini->smc_type_v1))
         goto not_found;
     ini->is_smcd = true; /* prepare ISM check */
     ini->ism_peer_gid[0] = ntohll(pclc_smcd->ism.gid);
     rc = smc_find_ism_device(new_smc, ini);
     if (rc)
         goto not_found;
     ini->ism_selected = 0;
     rc = smc_listen_ism_init(new_smc, ini);
     if (!rc)
         return;     /* V1 ISM device found */
 
 not_found:
     smc_find_ism_store_rc(rc, ini);
     ini->smcd_version &= ~SMC_V1;
     ini->ism_dev[0] = NULL;
     ini->is_smcd = false;
 }
 
 /* listen worker: register buffers */
 static int smc_listen_rdma_reg(struct smc_sock *new_smc, bool local_first)
 {
     struct smc_connection *conn = &new_smc->conn;
 
     if (!local_first) {
         /* reg sendbufs if they were vzalloced */
         if (conn->sndbuf_desc->is_vm) {
             if (smcr_lgr_reg_sndbufs(conn->lnk,
                          conn->sndbuf_desc))
                 return SMC_CLC_DECL_ERR_REGBUF;
         }
         if (smcr_lgr_reg_rmbs(conn->lnk, conn->rmb_desc))
             return SMC_CLC_DECL_ERR_REGBUF;
     }
 
     return 0;
 }
 
 static void smc_find_rdma_v2_device_serv(struct smc_sock *new_smc,
                      struct smc_clc_msg_proposal *pclc,
                      struct smc_init_info *ini)
 {
     struct smc_clc_v2_extension *smc_v2_ext;
     u8 smcr_version;
     int rc;
 
     if (!(ini->smcr_version & SMC_V2) || !smcr_indicated(ini->smc_type_v2))
         goto not_found;
 
     smc_v2_ext = smc_get_clc_v2_ext(pclc);
     if (!smc_clc_match_eid(ini->negotiated_eid, smc_v2_ext, NULL, NULL))
         goto not_found;
 
     /* prepare RDMA check */
     memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
     memcpy(ini->peer_gid, smc_v2_ext->roce, SMC_GID_SIZE);
     memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
     ini->check_smcrv2 = true;
     ini->smcrv2.clc_sk = new_smc->clcsock->sk;
     ini->smcrv2.saddr = new_smc->clcsock->sk->sk_rcv_saddr;
     ini->smcrv2.daddr = smc_ib_gid_to_ipv4(smc_v2_ext->roce);
     rc = smc_find_rdma_device(new_smc, ini);
     if (rc) {
         smc_find_ism_store_rc(rc, ini);
         goto not_found;
     }
     if (!ini->smcrv2.uses_gateway)
         memcpy(ini->smcrv2.nexthop_mac, pclc->lcl.mac, ETH_ALEN);
 
     smcr_version = ini->smcr_version;
     ini->smcr_version = SMC_V2;
     rc = smc_listen_rdma_init(new_smc, ini);
     if (!rc)
         rc = smc_listen_rdma_reg(new_smc, ini->first_contact_local);
     if (!rc)
         return;
     ini->smcr_version = smcr_version;
     smc_find_ism_store_rc(rc, ini);
 
 not_found:
     ini->smcr_version &= ~SMC_V2;
     ini->smcrv2.ib_dev_v2 = NULL;
     ini->check_smcrv2 = false;
 }
 
 static int smc_find_rdma_v1_device_serv(struct smc_sock *new_smc,
                     struct smc_clc_msg_proposal *pclc,
                     struct smc_init_info *ini)
 {
     int rc;
 
     if (!(ini->smcr_version & SMC_V1) || !smcr_indicated(ini->smc_type_v1))
         return SMC_CLC_DECL_NOSMCDEV;
 
     /* prepare RDMA check */
     memcpy(ini->peer_systemid, pclc->lcl.id_for_peer, SMC_SYSTEMID_LEN);
     memcpy(ini->peer_gid, pclc->lcl.gid, SMC_GID_SIZE);
     memcpy(ini->peer_mac, pclc->lcl.mac, ETH_ALEN);
     rc = smc_find_rdma_device(new_smc, ini);
     if (rc) {
         /* no RDMA device found */
         return SMC_CLC_DECL_NOSMCDEV;
     }
     rc = smc_listen_rdma_init(new_smc, ini);
     if (rc)
         return rc;
     return smc_listen_rdma_reg(new_smc, ini->first_contact_local);
 }
 
 /* determine the local device matching to proposal */
 static int smc_listen_find_device(struct smc_sock *new_smc,
                   struct smc_clc_msg_proposal *pclc,
                   struct smc_init_info *ini)
 {
     int prfx_rc;
 
     /* check for ISM device matching V2 proposed device */
     smc_find_ism_v2_device_serv(new_smc, pclc, ini);
     if (ini->ism_dev[0])
         return 0;
 
     /* check for matching IP prefix and subnet length (V1) */
     prfx_rc = smc_listen_prfx_check(new_smc, pclc);
     if (prfx_rc)
         smc_find_ism_store_rc(prfx_rc, ini);
 
     /* get vlan id from IP device */
     if (smc_vlan_by_tcpsk(new_smc->clcsock, ini))
         return ini->rc ?: SMC_CLC_DECL_GETVLANERR;
 
     /* check for ISM device matching V1 proposed device */
     if (!prfx_rc)
         smc_find_ism_v1_device_serv(new_smc, pclc, ini);
     if (ini->ism_dev[0])
         return 0;
 
     if (!smcr_indicated(pclc->hdr.typev1) &&
         !smcr_indicated(pclc->hdr.typev2))
         /* skip RDMA and decline */
         return ini->rc ?: SMC_CLC_DECL_NOSMCDDEV;
 
     /* check if RDMA V2 is available */
     smc_find_rdma_v2_device_serv(new_smc, pclc, ini);
     if (ini->smcrv2.ib_dev_v2)
         return 0;
 
     /* check if RDMA V1 is available */
     if (!prfx_rc) {
         int rc;
 
         rc = smc_find_rdma_v1_device_serv(new_smc, pclc, ini);
         smc_find_ism_store_rc(rc, ini);
         return (!rc) ? 0 : ini->rc;
     }
     return SMC_CLC_DECL_NOSMCDEV;
 }
 
 /* listen worker: finish RDMA setup */
 static int smc_listen_rdma_finish(struct smc_sock *new_smc,
                   struct smc_clc_msg_accept_confirm *cclc,
                   bool local_first,
                   struct smc_init_info *ini)
 {
     struct smc_link *link = new_smc->conn.lnk;
     int reason_code = 0;
 
     if (local_first)
         smc_link_save_peer_info(link, cclc, ini);
 
     if (smc_rmb_rtoken_handling(&new_smc->conn, link, cclc))
         return SMC_CLC_DECL_ERR_RTOK;
 
     if (local_first) {
         if (smc_ib_ready_link(link))
             return SMC_CLC_DECL_ERR_RDYLNK;
         /* QP confirmation over RoCE fabric */
         smc_llc_flow_initiate(link->lgr, SMC_LLC_FLOW_ADD_LINK);
         reason_code = smcr_serv_conf_first_link(new_smc);
         smc_llc_flow_stop(link->lgr, &link->lgr->llc_flow_lcl);
     }
     return reason_code;
 }
 
 /* setup for connection of server */
 static void smc_listen_work(struct work_struct *work)
 {
     struct smc_sock *new_smc = container_of(work, struct smc_sock,
                         smc_listen_work);
     struct socket *newclcsock = new_smc->clcsock;
     struct smc_clc_msg_accept_confirm *cclc;
     struct smc_clc_msg_proposal_area *buf;
     struct smc_clc_msg_proposal *pclc;
     struct smc_init_info *ini = NULL;
     u8 proposal_version = SMC_V1;
     u8 accept_version;
     int rc = 0;
 
     if (new_smc->listen_smc->sk.sk_state != SMC_LISTEN)
         return smc_listen_out_err(new_smc);
 
     if (new_smc->use_fallback) {
         smc_listen_out_connected(new_smc);
         return;
     }
 
     /* check if peer is smc capable */
     if (!tcp_sk(newclcsock->sk)->syn_smc) {
         rc = smc_switch_to_fallback(new_smc, SMC_CLC_DECL_PEERNOSMC);
         if (rc)
             smc_listen_out_err(new_smc);
         else
             smc_listen_out_connected(new_smc);
         return;
     }
 
     /* do inband token exchange -
      * wait for and receive SMC Proposal CLC message
      */
     buf = kzalloc(sizeof(*buf), GFP_KERNEL);
     if (!buf) {
         rc = SMC_CLC_DECL_MEM;
         goto out_decl;
     }
     pclc = (struct smc_clc_msg_proposal *)buf;
     rc = smc_clc_wait_msg(new_smc, pclc, sizeof(*buf),
                   SMC_CLC_PROPOSAL, CLC_WAIT_TIME);
     if (rc)
         goto out_decl;
 
     if (pclc->hdr.version > SMC_V1)
         proposal_version = SMC_V2;
 
     /* IPSec connections opt out of SMC optimizations */
     if (using_ipsec(new_smc)) {
         rc = SMC_CLC_DECL_IPSEC;
         goto out_decl;
     }
 
     ini = kzalloc(sizeof(*ini), GFP_KERNEL);
     if (!ini) {
         rc = SMC_CLC_DECL_MEM;
         goto out_decl;
     }
 
     /* initial version checking */
     rc = smc_listen_v2_check(new_smc, pclc, ini);
     if (rc)
         goto out_decl;
 
     mutex_lock(&smc_server_lgr_pending);
     smc_close_init(new_smc);
     smc_rx_init(new_smc);
     smc_tx_init(new_smc);
 
     /* determine ISM or RoCE device used for connection */
     rc = smc_listen_find_device(new_smc, pclc, ini);
     if (rc)
         goto out_unlock;
 
     /* send SMC Accept CLC message */
     accept_version = ini->is_smcd ? ini->smcd_version : ini->smcr_version;
     rc = smc_clc_send_accept(new_smc, ini->first_contact_local,
                  accept_version, ini->negotiated_eid);
     if (rc)
         goto out_unlock;
 
     /* SMC-D does not need this lock any more */
     if (ini->is_smcd)
         mutex_unlock(&smc_server_lgr_pending);
 
     /* receive SMC Confirm CLC message */
     memset(buf, 0, sizeof(*buf));
     cclc = (struct smc_clc_msg_accept_confirm *)buf;
     rc = smc_clc_wait_msg(new_smc, cclc, sizeof(*buf),
                   SMC_CLC_CONFIRM, CLC_WAIT_TIME);
     if (rc) {
         if (!ini->is_smcd)
             goto out_unlock;
         goto out_decl;
     }
 
     /* finish worker */
     if (!ini->is_smcd) {
         rc = smc_listen_rdma_finish(new_smc, cclc,
                         ini->first_contact_local, ini);
         if (rc)
             goto out_unlock;
         mutex_unlock(&smc_server_lgr_pending);
     }
     smc_conn_save_peer_info(new_smc, cclc);
     smc_listen_out_connected(new_smc);
     SMC_STAT_SERV_SUCC_INC(sock_net(newclcsock->sk), ini);
     goto out_free;
 
 out_unlock:
     mutex_unlock(&smc_server_lgr_pending);
 out_decl:
     smc_listen_decline(new_smc, rc, ini ? ini->first_contact_local : 0,
                proposal_version);
 out_free:
     kfree(ini);
     kfree(buf);
 }
 
 static void smc_tcp_listen_work(struct work_struct *work)
 {
     struct smc_sock *lsmc = container_of(work, struct smc_sock,
                          tcp_listen_work);
     struct sock *lsk = &lsmc->sk;
     struct smc_sock *new_smc;
     int rc = 0;
 
     lock_sock(lsk);
     while (lsk->sk_state == SMC_LISTEN) {
         rc = smc_clcsock_accept(lsmc, &new_smc);
         if (rc) /* clcsock accept queue empty or error */
             goto out;
         if (!new_smc)
             continue;
 
         if (tcp_sk(new_smc->clcsock->sk)->syn_smc)
             atomic_inc(&lsmc->queued_smc_hs);
 
         new_smc->listen_smc = lsmc;
         new_smc->use_fallback = lsmc->use_fallback;
         new_smc->fallback_rsn = lsmc->fallback_rsn;
         sock_hold(lsk); /* sock_put in smc_listen_work */
         INIT_WORK(&new_smc->smc_listen_work, smc_listen_work);
         smc_copy_sock_settings_to_smc(new_smc);
         new_smc->sk.sk_sndbuf = lsmc->sk.sk_sndbuf;
         new_smc->sk.sk_rcvbuf = lsmc->sk.sk_rcvbuf;
         sock_hold(&new_smc->sk); /* sock_put in passive closing */
         if (!queue_work(smc_hs_wq, &new_smc->smc_listen_work))
             sock_put(&new_smc->sk);
     }
 
 out:
     release_sock(lsk);
     sock_put(&lsmc->sk); /* sock_hold in smc_clcsock_data_ready() */
 }
 
 static void smc_clcsock_data_ready(struct sock *listen_clcsock)
 {
     struct smc_sock *lsmc;
 
     read_lock_bh(&listen_clcsock->sk_callback_lock);
     lsmc = smc_clcsock_user_data(listen_clcsock);
     if (!lsmc)
         goto out;
     lsmc->clcsk_data_ready(listen_clcsock);
     if (lsmc->sk.sk_state == SMC_LISTEN) {
         sock_hold(&lsmc->sk); /* sock_put in smc_tcp_listen_work() */
         if (!queue_work(smc_tcp_ls_wq, &lsmc->tcp_listen_work))
             sock_put(&lsmc->sk);
     }
 out:
     read_unlock_bh(&listen_clcsock->sk_callback_lock);
 }
 
 static int smc_listen(struct socket *sock, int backlog)
 {
     struct sock *sk = sock->sk;
     struct smc_sock *smc;
     int rc;
 
     smc = smc_sk(sk);
     lock_sock(sk);
 
     rc = -EINVAL;
     if ((sk->sk_state != SMC_INIT && sk->sk_state != SMC_LISTEN) ||
         smc->connect_nonblock || sock->state != SS_UNCONNECTED)
         goto out;
 
     rc = 0;
     if (sk->sk_state == SMC_LISTEN) {
         sk->sk_max_ack_backlog = backlog;
         goto out;
     }
     /* some socket options are handled in core, so we could not apply
      * them to the clc socket -- copy smc socket options to clc socket
      */
     smc_copy_sock_settings_to_clc(smc);
     if (!smc->use_fallback)
         tcp_sk(smc->clcsock->sk)->syn_smc = 1;
 
     /* save original sk_data_ready function and establish
      * smc-specific sk_data_ready function
      */
     write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
     smc->clcsock->sk->sk_user_data =
         (void *)((uintptr_t)smc | SK_USER_DATA_NOCOPY);
     smc_clcsock_replace_cb(&smc->clcsock->sk->sk_data_ready,
                    smc_clcsock_data_ready, &smc->clcsk_data_ready);
     write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
 
     /* save original ops */
     smc->ori_af_ops = inet_csk(smc->clcsock->sk)->icsk_af_ops;
 
     smc->af_ops = *smc->ori_af_ops;
     smc->af_ops.syn_recv_sock = smc_tcp_syn_recv_sock;
 
     inet_csk(smc->clcsock->sk)->icsk_af_ops = &smc->af_ops;
 
     if (smc->limit_smc_hs)
         tcp_sk(smc->clcsock->sk)->smc_hs_congested = smc_hs_congested;
 
     rc = kernel_listen(smc->clcsock, backlog);
     if (rc) {
         write_lock_bh(&smc->clcsock->sk->sk_callback_lock);
         smc_clcsock_restore_cb(&smc->clcsock->sk->sk_data_ready,
                        &smc->clcsk_data_ready);
         smc->clcsock->sk->sk_user_data = NULL;
         write_unlock_bh(&smc->clcsock->sk->sk_callback_lock);
         goto out;
     }
     sk->sk_max_ack_backlog = backlog;
     sk->sk_ack_backlog = 0;
     sk->sk_state = SMC_LISTEN;
 
 out:
     release_sock(sk);
     return rc;
 }
 
 static int smc_accept(struct socket *sock, struct socket *new_sock,
               int flags, bool kern)
 {
     struct sock *sk = sock->sk, *nsk;
     DECLARE_WAITQUEUE(wait, current);
     struct smc_sock *lsmc;
     long timeo;
     int rc = 0;
 
     lsmc = smc_sk(sk);
     sock_hold(sk); /* sock_put below */
     lock_sock(sk);
 
     if (lsmc->sk.sk_state != SMC_LISTEN) {
         rc = -EINVAL;
         release_sock(sk);
         goto out;
     }
 
     /* Wait for an incoming connection */
     timeo = sock_rcvtimeo(sk, flags & O_NONBLOCK);
     add_wait_queue_exclusive(sk_sleep(sk), &wait);
     while (!(nsk = smc_accept_dequeue(sk, new_sock))) {
         set_current_state(TASK_INTERRUPTIBLE);
         if (!timeo) {
             rc = -EAGAIN;
             break;
         }
         release_sock(sk);
         timeo = schedule_timeout(timeo);
         /* wakeup by sk_data_ready in smc_listen_work() */
         sched_annotate_sleep();
         lock_sock(sk);
         if (signal_pending(current)) {
             rc = sock_intr_errno(timeo);
             break;
         }
     }
     set_current_state(TASK_RUNNING);
     remove_wait_queue(sk_sleep(sk), &wait);
 
     if (!rc)
         rc = sock_error(nsk);
     release_sock(sk);
     if (rc)
         goto out;
 
     if (lsmc->sockopt_defer_accept && !(flags & O_NONBLOCK)) {
         /* wait till data arrives on the socket */
         timeo = msecs_to_jiffies(lsmc->sockopt_defer_accept *
                                 MSEC_PER_SEC);
         if (smc_sk(nsk)->use_fallback) {
             struct sock *clcsk = smc_sk(nsk)->clcsock->sk;
 
             lock_sock(clcsk);
             if (skb_queue_empty(&clcsk->sk_receive_queue))
                 sk_wait_data(clcsk, &timeo, NULL);
             release_sock(clcsk);
         } else if (!atomic_read(&smc_sk(nsk)->conn.bytes_to_rcv)) {
             lock_sock(nsk);
             smc_rx_wait(smc_sk(nsk), &timeo, smc_rx_data_available);
             release_sock(nsk);
         }
     }
 
 out:
     sock_put(sk); /* sock_hold above */
     return rc;
 }
 
 static int smc_getname(struct socket *sock, struct sockaddr *addr,
                int peer)
 {
     struct smc_sock *smc;
 
     if (peer && (sock->sk->sk_state != SMC_ACTIVE) &&
         (sock->sk->sk_state != SMC_APPCLOSEWAIT1))
         return -ENOTCONN;
 
     smc = smc_sk(sock->sk);
 
     return smc->clcsock->ops->getname(smc->clcsock, addr, peer);
 }
 
 static int smc_sendmsg(struct socket *sock, struct msghdr *msg, size_t len)
 {
     struct sock *sk = sock->sk;
     struct smc_sock *smc;
     int rc = -EPIPE;
 
     smc = smc_sk(sk);
     lock_sock(sk);
     if ((sk->sk_state != SMC_ACTIVE) &&
         (sk->sk_state != SMC_APPCLOSEWAIT1) &&
         (sk->sk_state != SMC_INIT))
         goto out;
 
     if (msg->msg_flags & MSG_FASTOPEN) {
         if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
             rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
             if (rc)
                 goto out;
         } else {
             rc = -EINVAL;
             goto out;
         }
     }
 
     if (smc->use_fallback) {
         rc = smc->clcsock->ops->sendmsg(smc->clcsock, msg, len);
     } else {
         rc = smc_tx_sendmsg(smc, msg, len);
         SMC_STAT_TX_PAYLOAD(smc, len, rc);
     }
 out:
     release_sock(sk);
     return rc;
 }
 
 static int smc_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
                int flags)
 {
     struct sock *sk = sock->sk;
     struct smc_sock *smc;
     int rc = -ENOTCONN;
 
     smc = smc_sk(sk);
     lock_sock(sk);
     if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
         /* socket was connected before, no more data to read */
         rc = 0;
         goto out;
     }
     if ((sk->sk_state == SMC_INIT) ||
         (sk->sk_state == SMC_LISTEN) ||
         (sk->sk_state == SMC_CLOSED))
         goto out;
 
     if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
         rc = 0;
         goto out;
     }
 
     if (smc->use_fallback) {
         rc = smc->clcsock->ops->recvmsg(smc->clcsock, msg, len, flags);
     } else {
         msg->msg_namelen = 0;
         rc = smc_rx_recvmsg(smc, msg, NULL, len, flags);
         SMC_STAT_RX_PAYLOAD(smc, rc, rc);
     }
 
 out:
     release_sock(sk);
     return rc;
 }
 
 static __poll_t smc_accept_poll(struct sock *parent)
 {
     struct smc_sock *isk = smc_sk(parent);
     __poll_t mask = 0;
 
     spin_lock(&isk->accept_q_lock);
     if (!list_empty(&isk->accept_q))
         mask = EPOLLIN | EPOLLRDNORM;
     spin_unlock(&isk->accept_q_lock);
 
     return mask;
 }
 
 static __poll_t smc_poll(struct file *file, struct socket *sock,
                  poll_table *wait)
 {
     struct sock *sk = sock->sk;
     struct smc_sock *smc;
     __poll_t mask = 0;
 
     if (!sk)
         return EPOLLNVAL;
 
     smc = smc_sk(sock->sk);
     if (smc->use_fallback) {
         /* delegate to CLC child sock */
         mask = smc->clcsock->ops->poll(file, smc->clcsock, wait);
         sk->sk_err = smc->clcsock->sk->sk_err;
     } else {
         if (sk->sk_state != SMC_CLOSED)
             sock_poll_wait(file, sock, wait);
         if (sk->sk_err)
             mask |= EPOLLERR;
         if ((sk->sk_shutdown == SHUTDOWN_MASK) ||
             (sk->sk_state == SMC_CLOSED))
             mask |= EPOLLHUP;
         if (sk->sk_state == SMC_LISTEN) {
             /* woken up by sk_data_ready in smc_listen_work() */
             mask |= smc_accept_poll(sk);
         } else if (smc->use_fallback) { /* as result of connect_work()*/
             mask |= smc->clcsock->ops->poll(file, smc->clcsock,
                                wait);
             sk->sk_err = smc->clcsock->sk->sk_err;
         } else {
             if ((sk->sk_state != SMC_INIT &&
                  atomic_read(&smc->conn.sndbuf_space)) ||
                 sk->sk_shutdown & SEND_SHUTDOWN) {
                 mask |= EPOLLOUT | EPOLLWRNORM;
             } else {
                 sk_set_bit(SOCKWQ_ASYNC_NOSPACE, sk);
                 set_bit(SOCK_NOSPACE, &sk->sk_socket->flags);
             }
             if (atomic_read(&smc->conn.bytes_to_rcv))
                 mask |= EPOLLIN | EPOLLRDNORM;
             if (sk->sk_shutdown & RCV_SHUTDOWN)
                 mask |= EPOLLIN | EPOLLRDNORM | EPOLLRDHUP;
             if (sk->sk_state == SMC_APPCLOSEWAIT1)
                 mask |= EPOLLIN;
             if (smc->conn.urg_state == SMC_URG_VALID)
                 mask |= EPOLLPRI;
         }
     }
 
     return mask;
 }
 
 static int smc_shutdown(struct socket *sock, int how)
 {
     struct sock *sk = sock->sk;
     bool do_shutdown = true;
     struct smc_sock *smc;
     int rc = -EINVAL;
     int old_state;
     int rc1 = 0;
 
     smc = smc_sk(sk);
 
     if ((how < SHUT_RD) || (how > SHUT_RDWR))
         return rc;
 
     lock_sock(sk);
 
     if (sock->state == SS_CONNECTING) {
         if (sk->sk_state == SMC_ACTIVE)
             sock->state = SS_CONNECTED;
         else if (sk->sk_state == SMC_PEERCLOSEWAIT1 ||
              sk->sk_state == SMC_PEERCLOSEWAIT2 ||
              sk->sk_state == SMC_APPCLOSEWAIT1 ||
              sk->sk_state == SMC_APPCLOSEWAIT2 ||
              sk->sk_state == SMC_APPFINCLOSEWAIT)
             sock->state = SS_DISCONNECTING;
     }
 
     rc = -ENOTCONN;
     if ((sk->sk_state != SMC_ACTIVE) &&
         (sk->sk_state != SMC_PEERCLOSEWAIT1) &&
         (sk->sk_state != SMC_PEERCLOSEWAIT2) &&
         (sk->sk_state != SMC_APPCLOSEWAIT1) &&
         (sk->sk_state != SMC_APPCLOSEWAIT2) &&
         (sk->sk_state != SMC_APPFINCLOSEWAIT))
         goto out;
     if (smc->use_fallback) {
         rc = kernel_sock_shutdown(smc->clcsock, how);
         sk->sk_shutdown = smc->clcsock->sk->sk_shutdown;
         if (sk->sk_shutdown == SHUTDOWN_MASK) {
             sk->sk_state = SMC_CLOSED;
             sk->sk_socket->state = SS_UNCONNECTED;
             sock_put(sk);
         }
         goto out;
     }
     switch (how) {
     case SHUT_RDWR:     /* shutdown in both directions */
         old_state = sk->sk_state;
         rc = smc_close_active(smc);
         if (old_state == SMC_ACTIVE &&
             sk->sk_state == SMC_PEERCLOSEWAIT1)
             do_shutdown = false;
         break;
     case SHUT_WR:
         rc = smc_close_shutdown_write(smc);
         break;
     case SHUT_RD:
         rc = 0;
         /* nothing more to do because peer is not involved */
         break;
     }
     if (do_shutdown && smc->clcsock)
         rc1 = kernel_sock_shutdown(smc->clcsock, how);
     /* map sock_shutdown_cmd constants to sk_shutdown value range */
     sk->sk_shutdown |= how + 1;
 
     if (sk->sk_state == SMC_CLOSED)
         sock->state = SS_UNCONNECTED;
     else
         sock->state = SS_DISCONNECTING;
 out:
     release_sock(sk);
     return rc ? rc : rc1;
 }
 
 static int __smc_getsockopt(struct socket *sock, int level, int optname,
                 char __user *optval, int __user *optlen)
 {
     struct smc_sock *smc;
     int val, len;
 
     smc = smc_sk(sock->sk);
 
     if (get_user(len, optlen))
         return -EFAULT;
 
     len = min_t(int, len, sizeof(int));
 
     if (len < 0)
         return -EINVAL;
 
     switch (optname) {
     case SMC_LIMIT_HS:
         val = smc->limit_smc_hs;
         break;
     default:
         return -EOPNOTSUPP;
     }
 
     if (put_user(len, optlen))
         return -EFAULT;
     if (copy_to_user(optval, &val, len))
         return -EFAULT;
 
     return 0;
 }
 
 static int __smc_setsockopt(struct socket *sock, int level, int optname,
                 sockptr_t optval, unsigned int optlen)
 {
     struct sock *sk = sock->sk;
     struct smc_sock *smc;
     int val, rc;
 
     smc = smc_sk(sk);
 
     lock_sock(sk);
     switch (optname) {
     case SMC_LIMIT_HS:
         if (optlen < sizeof(int)) {
             rc = -EINVAL;
             break;
         }
         if (copy_from_sockptr(&val, optval, sizeof(int))) {
             rc = -EFAULT;
             break;
         }
 
         smc->limit_smc_hs = !!val;
         rc = 0;
         break;
     default:
         rc = -EOPNOTSUPP;
         break;
     }
     release_sock(sk);
 
     return rc;
 }
 
 static int smc_setsockopt(struct socket *sock, int level, int optname,
               sockptr_t optval, unsigned int optlen)
 {
     struct sock *sk = sock->sk;
     struct smc_sock *smc;
     int val, rc;
 
     if (level == SOL_TCP && optname == TCP_ULP)
         return -EOPNOTSUPP;
     else if (level == SOL_SMC)
         return __smc_setsockopt(sock, level, optname, optval, optlen);
 
     smc = smc_sk(sk);
 
     /* generic setsockopts reaching us here always apply to the
      * CLC socket
      */
     mutex_lock(&smc->clcsock_release_lock);
     if (!smc->clcsock) {
         mutex_unlock(&smc->clcsock_release_lock);
         return -EBADF;
     }
     if (unlikely(!smc->clcsock->ops->setsockopt))
         rc = -EOPNOTSUPP;
     else
         rc = smc->clcsock->ops->setsockopt(smc->clcsock, level, optname,
                            optval, optlen);
     if (smc->clcsock->sk->sk_err) {
         sk->sk_err = smc->clcsock->sk->sk_err;
         sk_error_report(sk);
     }
     mutex_unlock(&smc->clcsock_release_lock);
 
     if (optlen < sizeof(int))
         return -EINVAL;
     if (copy_from_sockptr(&val, optval, sizeof(int)))
         return -EFAULT;
 
     lock_sock(sk);
     if (rc || smc->use_fallback)
         goto out;
     switch (optname) {
     case TCP_FASTOPEN:
     case TCP_FASTOPEN_CONNECT:
     case TCP_FASTOPEN_KEY:
     case TCP_FASTOPEN_NO_COOKIE:
         /* option not supported by SMC */
         if (sk->sk_state == SMC_INIT && !smc->connect_nonblock) {
             rc = smc_switch_to_fallback(smc, SMC_CLC_DECL_OPTUNSUPP);
         } else {
             rc = -EINVAL;
         }
         break;
     case TCP_NODELAY:
         if (sk->sk_state != SMC_INIT &&
             sk->sk_state != SMC_LISTEN &&
             sk->sk_state != SMC_CLOSED) {
             if (val) {
                 SMC_STAT_INC(smc, ndly_cnt);
                 smc_tx_pending(&smc->conn);
                 cancel_delayed_work(&smc->conn.tx_work);
             }
         }
         break;
     case TCP_CORK:
         if (sk->sk_state != SMC_INIT &&
             sk->sk_state != SMC_LISTEN &&
             sk->sk_state != SMC_CLOSED) {
             if (!val) {
                 SMC_STAT_INC(smc, cork_cnt);
                 smc_tx_pending(&smc->conn);
                 cancel_delayed_work(&smc->conn.tx_work);
             }
         }
         break;
     case TCP_DEFER_ACCEPT:
         smc->sockopt_defer_accept = val;
         break;
     default:
         break;
     }
 out:
     release_sock(sk);
 
     return rc;
 }
 
 static int smc_getsockopt(struct socket *sock, int level, int optname,
               char __user *optval, int __user *optlen)
 {
     struct smc_sock *smc;
     int rc;
 
     if (level == SOL_SMC)
         return __smc_getsockopt(sock, level, optname, optval, optlen);
 
     smc = smc_sk(sock->sk);
     mutex_lock(&smc->clcsock_release_lock);
     if (!smc->clcsock) {
         mutex_unlock(&smc->clcsock_release_lock);
         return -EBADF;
     }
     /* socket options apply to the CLC socket */
     if (unlikely(!smc->clcsock->ops->getsockopt)) {
         mutex_unlock(&smc->clcsock_release_lock);
         return -EOPNOTSUPP;
     }
     rc = smc->clcsock->ops->getsockopt(smc->clcsock, level, optname,
                        optval, optlen);
     mutex_unlock(&smc->clcsock_release_lock);
     return rc;
 }
 
 static int smc_ioctl(struct socket *sock, unsigned int cmd,
              unsigned long arg)
 {
     union smc_host_cursor cons, urg;
     struct smc_connection *conn;
     struct smc_sock *smc;
     int answ;
 
     smc = smc_sk(sock->sk);
     conn = &smc->conn;
     lock_sock(&smc->sk);
     if (smc->use_fallback) {
         if (!smc->clcsock) {
             release_sock(&smc->sk);
             return -EBADF;
         }
         answ = smc->clcsock->ops->ioctl(smc->clcsock, cmd, arg);
         release_sock(&smc->sk);
         return answ;
     }
     switch (cmd) {
     case SIOCINQ: /* same as FIONREAD */
         if (smc->sk.sk_state == SMC_LISTEN) {
             release_sock(&smc->sk);
             return -EINVAL;
         }
         if (smc->sk.sk_state == SMC_INIT ||
             smc->sk.sk_state == SMC_CLOSED)
             answ = 0;
         else
             answ = atomic_read(&smc->conn.bytes_to_rcv);
         break;
     case SIOCOUTQ:
         /* output queue size (not send + not acked) */
         if (smc->sk.sk_state == SMC_LISTEN) {
             release_sock(&smc->sk);
             return -EINVAL;
         }
         if (smc->sk.sk_state == SMC_INIT ||
             smc->sk.sk_state == SMC_CLOSED)
             answ = 0;
         else
             answ = smc->conn.sndbuf_desc->len -
                     atomic_read(&smc->conn.sndbuf_space);
         break;
     case SIOCOUTQNSD:
         /* output queue size (not send only) */
         if (smc->sk.sk_state == SMC_LISTEN) {
             release_sock(&smc->sk);
             return -EINVAL;
         }
         if (smc->sk.sk_state == SMC_INIT ||
             smc->sk.sk_state == SMC_CLOSED)
             answ = 0;
         else
             answ = smc_tx_prepared_sends(&smc->conn);
         break;
     case SIOCATMARK:
         if (smc->sk.sk_state == SMC_LISTEN) {
             release_sock(&smc->sk);
             return -EINVAL;
         }
         if (smc->sk.sk_state == SMC_INIT ||
             smc->sk.sk_state == SMC_CLOSED) {
             answ = 0;
         } else {
             smc_curs_copy(&cons, &conn->local_tx_ctrl.cons, conn);
             smc_curs_copy(&urg, &conn->urg_curs, conn);
             answ = smc_curs_diff(conn->rmb_desc->len,
                          &cons, &urg) == 1;
         }
         break;
     default:
         release_sock(&smc->sk);
         return -ENOIOCTLCMD;
     }
     release_sock(&smc->sk);
 
     return put_user(answ, (int __user *)arg);
 }
 
 static ssize_t smc_sendpage(struct socket *sock, struct page *page,
                 int offset, size_t size, int flags)
 {
     struct sock *sk = sock->sk;
     struct smc_sock *smc;
     int rc = -EPIPE;
 
     smc = smc_sk(sk);
     lock_sock(sk);
     if (sk->sk_state != SMC_ACTIVE) {
         release_sock(sk);
         goto out;
     }
     release_sock(sk);
     if (smc->use_fallback) {
         rc = kernel_sendpage(smc->clcsock, page, offset,
                      size, flags);
     } else {
         lock_sock(sk);
         rc = smc_tx_sendpage(smc, page, offset, size, flags);
         release_sock(sk);
         SMC_STAT_INC(smc, sendpage_cnt);
     }
 
 out:
     return rc;
 }
 
 /* Map the affected portions of the rmbe into an spd, note the number of bytes
  * to splice in conn->splice_pending, and press 'go'. Delays consumer cursor
  * updates till whenever a respective page has been fully processed.
  * Note that subsequent recv() calls have to wait till all splice() processing
  * completed.
  */
 static ssize_t smc_splice_read(struct socket *sock, loff_t *ppos,
                    struct pipe_inode_info *pipe, size_t len,
                    unsigned int flags)
 {
     struct sock *sk = sock->sk;
     struct smc_sock *smc;
     int rc = -ENOTCONN;
 
     smc = smc_sk(sk);
     lock_sock(sk);
     if (sk->sk_state == SMC_CLOSED && (sk->sk_shutdown & RCV_SHUTDOWN)) {
         /* socket was connected before, no more data to read */
         rc = 0;
         goto out;
     }
     if (sk->sk_state == SMC_INIT ||
         sk->sk_state == SMC_LISTEN ||
         sk->sk_state == SMC_CLOSED)
         goto out;
 
     if (sk->sk_state == SMC_PEERFINCLOSEWAIT) {
         rc = 0;
         goto out;
     }
 
     if (smc->use_fallback) {
         rc = smc->clcsock->ops->splice_read(smc->clcsock, ppos,
                             pipe, len, flags);
     } else {
         if (*ppos) {
             rc = -ESPIPE;
             goto out;
         }
         if (flags & SPLICE_F_NONBLOCK)
             flags = MSG_DONTWAIT;
         else
             flags = 0;
         SMC_STAT_INC(smc, splice_cnt);
         rc = smc_rx_recvmsg(smc, NULL, pipe, len, flags);
     }
 out:
     release_sock(sk);
 
     return rc;
 }
 
 /* must look like tcp */
 static const struct proto_ops smc_sock_ops = {
     .family     = PF_SMC,
     .owner      = THIS_MODULE,
     .release    = smc_release,
     .bind       = smc_bind,
     .connect    = smc_connect,
     .socketpair = sock_no_socketpair,
     .accept     = smc_accept,
     .getname    = smc_getname,
     .poll       = smc_poll,
     .ioctl      = smc_ioctl,
     .listen     = smc_listen,
     .shutdown   = smc_shutdown,
     .setsockopt = smc_setsockopt,
     .getsockopt = smc_getsockopt,
     .sendmsg    = smc_sendmsg,
     .recvmsg    = smc_recvmsg,
     .mmap       = sock_no_mmap,
     .sendpage   = smc_sendpage,
     .splice_read    = smc_splice_read,
 };
 
 static int __smc_create(struct net *net, struct socket *sock, int protocol,
             int kern, struct socket *clcsock)
 {
     int family = (protocol == SMCPROTO_SMC6) ? PF_INET6 : PF_INET;
     struct smc_sock *smc;
     struct sock *sk;
     int rc;
 
     rc = -ESOCKTNOSUPPORT;
     if (sock->type != SOCK_STREAM)
         goto out;
 
     rc = -EPROTONOSUPPORT;
     if (protocol != SMCPROTO_SMC && protocol != SMCPROTO_SMC6)
         goto out;
 
     rc = -ENOBUFS;
     sock->ops = &smc_sock_ops;
     sock->state = SS_UNCONNECTED;
     sk = smc_sock_alloc(net, sock, protocol);
     if (!sk)
         goto out;
 
     /* create internal TCP socket for CLC handshake and fallback */
     smc = smc_sk(sk);
     smc->use_fallback = false; /* assume rdma capability first */
     smc->fallback_rsn = 0;
 
     /* default behavior from limit_smc_hs in every net namespace */
     smc->limit_smc_hs = net->smc.limit_smc_hs;
 
     rc = 0;
     if (!clcsock) {
         rc = sock_create_kern(net, family, SOCK_STREAM, IPPROTO_TCP,
                       &smc->clcsock);
         if (rc) {
             sk_common_release(sk);
             goto out;
         }
     } else {
         smc->clcsock = clcsock;
     }
 
     smc->sk.sk_sndbuf = max(smc->clcsock->sk->sk_sndbuf, SMC_BUF_MIN_SIZE);
     smc->sk.sk_rcvbuf = max(smc->clcsock->sk->sk_rcvbuf, SMC_BUF_MIN_SIZE);
 
 out:
     return rc;
 }
 
 static int smc_create(struct net *net, struct socket *sock, int protocol,
               int kern)
 {
     return __smc_create(net, sock, protocol, kern, NULL);
 }
 
 static const struct net_proto_family smc_sock_family_ops = {
     .family = PF_SMC,
     .owner  = THIS_MODULE,
     .create = smc_create,
 };
 
 static int smc_ulp_init(struct sock *sk)
 {
     struct socket *tcp = sk->sk_socket;
     struct net *net = sock_net(sk);
     struct socket *smcsock;
     int protocol, ret;
 
     /* only TCP can be replaced */
     if (tcp->type != SOCK_STREAM || sk->sk_protocol != IPPROTO_TCP ||
         (sk->sk_family != AF_INET && sk->sk_family != AF_INET6))
         return -ESOCKTNOSUPPORT;
     /* don't handle wq now */
     if (tcp->state != SS_UNCONNECTED || !tcp->file || tcp->wq.fasync_list)
         return -ENOTCONN;
 
     if (sk->sk_family == AF_INET)
         protocol = SMCPROTO_SMC;
     else
         protocol = SMCPROTO_SMC6;
 
     smcsock = sock_alloc();
     if (!smcsock)
         return -ENFILE;
 
     smcsock->type = SOCK_STREAM;
     __module_get(THIS_MODULE); /* tried in __tcp_ulp_find_autoload */
     ret = __smc_create(net, smcsock, protocol, 1, tcp);
     if (ret) {
         sock_release(smcsock); /* module_put() which ops won't be NULL */
         return ret;
     }
 
     /* replace tcp socket to smc */
     smcsock->file = tcp->file;
     smcsock->file->private_data = smcsock;
     smcsock->file->f_inode = SOCK_INODE(smcsock); /* replace inode when sock_close */
     smcsock->file->f_path.dentry->d_inode = SOCK_INODE(smcsock); /* dput() in __fput */
     tcp->file = NULL;
 
     return ret;
 }
 
 static void smc_ulp_clone(const struct request_sock *req, struct sock *newsk,
               const gfp_t priority)
 {
     struct inet_connection_sock *icsk = inet_csk(newsk);
 
     /* don't inherit ulp ops to child when listen */
     icsk->icsk_ulp_ops = NULL;
 }
 
 static struct tcp_ulp_ops smc_ulp_ops __read_mostly = {
     .name       = "smc",
     .owner      = THIS_MODULE,
     .init       = smc_ulp_init,
     .clone      = smc_ulp_clone,
 };
 
 unsigned int smc_net_id;
 
 static __net_init int smc_net_init(struct net *net)
 {
     int rc;
 
     rc = smc_sysctl_net_init(net);
     if (rc)
         return rc;
     return smc_pnet_net_init(net);
 }
 
 static void __net_exit smc_net_exit(struct net *net)
 {
     smc_sysctl_net_exit(net);
     smc_pnet_net_exit(net);
 }
 
 static __net_init int smc_net_stat_init(struct net *net)
 {
     return smc_stats_init(net);
 }
 
 static void __net_exit smc_net_stat_exit(struct net *net)
 {
     smc_stats_exit(net);
 }
 
 static struct pernet_operations smc_net_ops = {
     .init = smc_net_init,
     .exit = smc_net_exit,
     .id   = &smc_net_id,
     .size = sizeof(struct smc_net),
 };
 
 static struct pernet_operations smc_net_stat_ops = {
     .init = smc_net_stat_init,
     .exit = smc_net_stat_exit,
 };
 
 static int __init smc_init(void)
 {
     int rc;
 
     rc = register_pernet_subsys(&smc_net_ops);
     if (rc)
         return rc;
 
     rc = register_pernet_subsys(&smc_net_stat_ops);
     if (rc)
         return rc;
 
     smc_ism_init();
     smc_clc_init();
 
     rc = smc_nl_init();
     if (rc)
         goto out_pernet_subsys;
 
     rc = smc_pnet_init();
     if (rc)
         goto out_nl;
 
     rc = -ENOMEM;
 
     smc_tcp_ls_wq = alloc_workqueue("smc_tcp_ls_wq", 0, 0);
     if (!smc_tcp_ls_wq)
         goto out_pnet;
 
     smc_hs_wq = alloc_workqueue("smc_hs_wq", 0, 0);
     if (!smc_hs_wq)
         goto out_alloc_tcp_ls_wq;
 
     smc_close_wq = alloc_workqueue("smc_close_wq", 0, 0);
     if (!smc_close_wq)
         goto out_alloc_hs_wq;
 
     rc = smc_core_init();
     if (rc) {
         pr_err("%s: smc_core_init fails with %d\n", __func__, rc);
         goto out_alloc_wqs;
     }
 
     rc = smc_llc_init();
     if (rc) {
         pr_err("%s: smc_llc_init fails with %d\n", __func__, rc);
         goto out_core;
     }
 
     rc = smc_cdc_init();
     if (rc) {
         pr_err("%s: smc_cdc_init fails with %d\n", __func__, rc);
         goto out_core;
     }
 
     rc = proto_register(&smc_proto, 1);
     if (rc) {
         pr_err("%s: proto_register(v4) fails with %d\n", __func__, rc);
         goto out_core;
     }
 
     rc = proto_register(&smc_proto6, 1);
     if (rc) {
         pr_err("%s: proto_register(v6) fails with %d\n", __func__, rc);
         goto out_proto;
     }
 
     rc = sock_register(&smc_sock_family_ops);
     if (rc) {
         pr_err("%s: sock_register fails with %d\n", __func__, rc);
         goto out_proto6;
     }
     INIT_HLIST_HEAD(&smc_v4_hashinfo.ht);
     INIT_HLIST_HEAD(&smc_v6_hashinfo.ht);
 
     rc = smc_ib_register_client();
     if (rc) {
         pr_err("%s: ib_register fails with %d\n", __func__, rc);
         goto out_sock;
     }
 
     rc = tcp_register_ulp(&smc_ulp_ops);
     if (rc) {
         pr_err("%s: tcp_ulp_register fails with %d\n", __func__, rc);
         goto out_ib;
     }
 
     static_branch_enable(&tcp_have_smc);
     return 0;
 
 out_ib:
     smc_ib_unregister_client();
 out_sock:
     sock_unregister(PF_SMC);
 out_proto6:
     proto_unregister(&smc_proto6);
 out_proto:
     proto_unregister(&smc_proto);
 out_core:
     smc_core_exit();
 out_alloc_wqs:
     destroy_workqueue(smc_close_wq);
 out_alloc_hs_wq:
     destroy_workqueue(smc_hs_wq);
 out_alloc_tcp_ls_wq:
     destroy_workqueue(smc_tcp_ls_wq);
 out_pnet:
     smc_pnet_exit();
 out_nl:
     smc_nl_exit();
 out_pernet_subsys:
     unregister_pernet_subsys(&smc_net_ops);
 
     return rc;
 }
 
 static void __exit smc_exit(void)
 {
     static_branch_disable(&tcp_have_smc);
     tcp_unregister_ulp(&smc_ulp_ops);
     sock_unregister(PF_SMC);
     smc_core_exit();
     smc_ib_unregister_client();
     destroy_workqueue(smc_close_wq);
     destroy_workqueue(smc_tcp_ls_wq);
     destroy_workqueue(smc_hs_wq);
     proto_unregister(&smc_proto6);
     proto_unregister(&smc_proto);
     smc_pnet_exit();
     smc_nl_exit();
     smc_clc_exit();
     unregister_pernet_subsys(&smc_net_stat_ops);
     unregister_pernet_subsys(&smc_net_ops);
     rcu_barrier();
 }
 
 module_init(smc_init);
 module_exit(smc_exit);
 
 MODULE_AUTHOR("Ursula Braun <ubraun@linux.vnet.ibm.com>");
 MODULE_DESCRIPTION("smc socket address family");
 MODULE_LICENSE("GPL");
 MODULE_ALIAS_NETPROTO(PF_SMC);
 MODULE_ALIAS_TCP_ULP("smc");
 MODULE_ALIAS_GENL_FAMILY(SMC_GENL_FAMILY_NAME);