Whamcloud - gitweb
LU-9679 modules: Use LIST_HEAD for declaring list_heads
[fs/lustre-release.git] / lnet / klnds / socklnd / socklnd_cb.c
index 60635d4..f7b39b7 100644 (file)
@@ -1,13 +1,14 @@
-/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
- * vim:expandtab:shiftwidth=8:tabstop=8:
+/*
+ * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
+ *
+ * Copyright (c) 2011, 2017, Intel Corporation.
  *
- * Copyright (C) 2001, 2002 Cluster File Systems, Inc.
  *   Author: Zach Brown <zab@zabbo.net>
  *   Author: Peter J. Braam <braam@clusterfs.com>
  *   Author: Phil Schwan <phil@clusterfs.com>
  *   Author: Eric Barton <eric@bartonsoftware.com>
  *
- *   This file is part of Portals, http://www.sf.net/projects/sandiaportals/
+ *   This file is part of Lustre, https://wiki.whamcloud.com/
  *
  *   Portals is free software; you can redistribute it and/or
  *   modify it under the terms of version 2 of the GNU General Public
 
 #include "socklnd.h"
 
-ksock_tx_t *
-ksocknal_alloc_tx (int size) 
+struct ksock_tx *
+ksocknal_alloc_tx(int type, int size)
 {
-        ksock_tx_t *tx = NULL;
+       struct ksock_tx *tx = NULL;
 
-        if (size == KSOCK_NOOP_TX_SIZE) {
-                /* searching for a noop tx in free list */
-                spin_lock(&ksocknal_data.ksnd_tx_lock);
+       if (type == KSOCK_MSG_NOOP) {
+               LASSERT(size == KSOCK_NOOP_TX_SIZE);
 
-                if (!list_empty(&ksocknal_data.ksnd_idle_noop_txs)) {
-                        tx = list_entry(ksocknal_data.ksnd_idle_noop_txs.next,
-                                        ksock_tx_t, tx_list);
-                        LASSERT(tx->tx_desc_size == size);
-                        list_del(&tx->tx_list);
-                }
-                             
-                spin_unlock(&ksocknal_data.ksnd_tx_lock);
+               /* searching for a noop tx in free list */
+               spin_lock(&ksocknal_data.ksnd_tx_lock);
+
+               if (!list_empty(&ksocknal_data.ksnd_idle_noop_txs)) {
+                       tx = list_entry(ksocknal_data.ksnd_idle_noop_txs.next,
+                                       struct ksock_tx, tx_list);
+                       LASSERT(tx->tx_desc_size == size);
+                       list_del(&tx->tx_list);
+               }
+
+               spin_unlock(&ksocknal_data.ksnd_tx_lock);
         }
-                
+
         if (tx == NULL)
                 LIBCFS_ALLOC(tx, size);
 
-        if (tx == NULL) 
+        if (tx == NULL)
                 return NULL;
 
-        atomic_set(&tx->tx_refcount, 1);
-        tx->tx_desc_size = size;
-        atomic_inc(&ksocknal_data.ksnd_nactive_txs);
+       atomic_set(&tx->tx_refcount, 1);
+       tx->tx_zc_aborted = 0;
+       tx->tx_zc_capable = 0;
+       tx->tx_zc_checked = 0;
+       tx->tx_hstatus = LNET_MSG_STATUS_OK;
+       tx->tx_desc_size  = size;
 
-        return tx;
+       atomic_inc(&ksocknal_data.ksnd_nactive_txs);
+
+       return tx;
 }
 
-void
-ksocknal_free_tx (ksock_tx_t *tx)
+struct ksock_tx *
+ksocknal_alloc_tx_noop(__u64 cookie, int nonblk)
 {
-        atomic_dec(&ksocknal_data.ksnd_nactive_txs);
+       struct ksock_tx *tx;
+
+        tx = ksocknal_alloc_tx(KSOCK_MSG_NOOP, KSOCK_NOOP_TX_SIZE);
+        if (tx == NULL) {
+                CERROR("Can't allocate noop tx desc\n");
+                return NULL;
+        }
 
-        if (tx->tx_desc_size == KSOCK_NOOP_TX_SIZE) {
-                /* it's a noop tx */
-                spin_lock(&ksocknal_data.ksnd_tx_lock);
+        tx->tx_conn     = NULL;
+        tx->tx_lnetmsg  = NULL;
+        tx->tx_kiov     = NULL;
+        tx->tx_nkiov    = 0;
+        tx->tx_iov      = tx->tx_frags.virt.iov;
+        tx->tx_niov     = 1;
+        tx->tx_nonblk   = nonblk;
 
-                list_add(&tx->tx_list, &ksocknal_data.ksnd_idle_noop_txs);
+       tx->tx_msg.ksm_csum = 0;
+       tx->tx_msg.ksm_type = KSOCK_MSG_NOOP;
+       tx->tx_msg.ksm_zc_cookies[0] = 0;
+        tx->tx_msg.ksm_zc_cookies[1] = cookie;
 
-                spin_unlock(&ksocknal_data.ksnd_tx_lock);
-        } else {
-                LIBCFS_FREE(tx, tx->tx_desc_size);
-        }
+        return tx;
 }
 
+
 void
-ksocknal_init_msg(ksock_msg_t *msg, int type)
+ksocknal_free_tx(struct ksock_tx *tx)
 {
-        msg->ksm_type           = type;
-        msg->ksm_csum           = 0;
-        msg->ksm_zc_req_cookie  = 0;
-        msg->ksm_zc_ack_cookie  = 0;
-}
+       atomic_dec(&ksocknal_data.ksnd_nactive_txs);
 
-int
-ksocknal_send_iov (ksock_conn_t *conn, ksock_tx_t *tx)
-{ 
-        struct iovec  *iov = tx->tx_iov;
-        int    nob;
-        int    rc;
+       if (tx->tx_lnetmsg == NULL && tx->tx_desc_size == KSOCK_NOOP_TX_SIZE) {
+               /* it's a noop tx */
+               spin_lock(&ksocknal_data.ksnd_tx_lock);
 
-        LASSERT (tx->tx_niov > 0);
+               list_add(&tx->tx_list, &ksocknal_data.ksnd_idle_noop_txs);
 
-        /* Never touch tx->tx_iov inside ksocknal_lib_send_iov() */
-        rc = ksocknal_lib_send_iov(conn, tx);
+               spin_unlock(&ksocknal_data.ksnd_tx_lock);
+       } else {
+               LIBCFS_FREE(tx, tx->tx_desc_size);
+       }
+}
 
-        if (rc <= 0)                            /* sent nothing? */ 
-                return (rc);
+static int
+ksocknal_send_iov(struct ksock_conn *conn, struct ksock_tx *tx,
+                 struct kvec *scratch_iov)
+{
+       struct kvec *iov = tx->tx_iov;
+       int    nob;
+       int    rc;
 
-        nob = rc; 
-        LASSERT (nob <= tx->tx_resid); 
-        tx->tx_resid -= nob;
+       LASSERT(tx->tx_niov > 0);
 
-        /* "consume" iov */ 
-        do { 
-                LASSERT (tx->tx_niov > 0); 
+       /* Never touch tx->tx_iov inside ksocknal_lib_send_iov() */
+       rc = ksocknal_lib_send_iov(conn, tx, scratch_iov);
 
-                if (nob < iov->iov_len) { 
-                        iov->iov_base = (void *)(((unsigned long)(iov->iov_base)) + nob); 
-                        iov->iov_len -= nob; 
-                        return (rc); 
-                } 
+       if (rc <= 0)                            /* sent nothing? */
+               return rc;
 
-                nob -= iov->iov_len; 
-                tx->tx_iov = ++iov; 
-                tx->tx_niov--; 
-        } while (nob != 0);
+       nob = rc;
+       LASSERT(nob <= tx->tx_resid);
+       tx->tx_resid -= nob;
 
-        return (rc);
-}
+       /* "consume" iov */
+       do {
+               LASSERT(tx->tx_niov > 0);
 
-int
-ksocknal_send_kiov (ksock_conn_t *conn, ksock_tx_t *tx)
-{ 
-        lnet_kiov_t    *kiov = tx->tx_kiov;
-        int     nob;
-        int     rc;
-
-        LASSERT (tx->tx_niov == 0); 
-        LASSERT (tx->tx_nkiov > 0);
-
-        /* Never touch tx->tx_kiov inside ksocknal_lib_send_kiov() */
-        rc = ksocknal_lib_send_kiov(conn, tx);
-
-        if (rc <= 0)                            /* sent nothing? */ 
-                return (rc); 
-        
-        nob = rc; 
-        LASSERT (nob <= tx->tx_resid); 
-        tx->tx_resid -= nob; 
-
-        /* "consume" kiov */ 
-        do { 
-                LASSERT(tx->tx_nkiov > 0); 
-
-                if (nob < kiov->kiov_len) { 
-                        kiov->kiov_offset += nob; 
-                        kiov->kiov_len -= nob; 
-                        return rc; 
-                } 
-
-                nob -= kiov->kiov_len; 
-                tx->tx_kiov = ++kiov; 
-                tx->tx_nkiov--; 
-        } while (nob != 0);
-
-        return (rc);
+               if (nob < (int) iov->iov_len) {
+                       iov->iov_base += nob;
+                       iov->iov_len -= nob;
+                       return rc;
+               }
+
+               nob -= iov->iov_len;
+               tx->tx_iov = ++iov;
+               tx->tx_niov--;
+       } while (nob != 0);
+
+       return rc;
 }
 
-int
-ksocknal_transmit (ksock_conn_t *conn, ksock_tx_t *tx)
+static int
+ksocknal_send_kiov(struct ksock_conn *conn, struct ksock_tx *tx,
+                  struct kvec *scratch_iov)
 {
-        int      rc;
-        int      bufnob;
-        
-        if (ksocknal_data.ksnd_stall_tx != 0) {
-                cfs_pause(cfs_time_seconds(ksocknal_data.ksnd_stall_tx));
-        }
+       lnet_kiov_t *kiov = tx->tx_kiov;
+       int nob;
+       int rc;
 
-        LASSERT (tx->tx_resid != 0);
+       LASSERT(tx->tx_niov == 0);
+       LASSERT(tx->tx_nkiov > 0);
 
-        rc = ksocknal_connsock_addref(conn);
-        if (rc != 0) {
-                LASSERT (conn->ksnc_closing);
-                return (-ESHUTDOWN);
-        }
+       /* Never touch tx->tx_kiov inside ksocknal_lib_send_kiov() */
+       rc = ksocknal_lib_send_kiov(conn, tx, scratch_iov);
 
-        do {
-                if (ksocknal_data.ksnd_enomem_tx > 0) {
-                        /* testing... */
-                        ksocknal_data.ksnd_enomem_tx--;
-                        rc = -EAGAIN;
-                } else if (tx->tx_niov != 0) {
-                        rc = ksocknal_send_iov (conn, tx);
-                } else {
-                        rc = ksocknal_send_kiov (conn, tx);
-                }
+       if (rc <= 0)                            /* sent nothing? */
+               return rc;
 
-                bufnob = SOCK_WMEM_QUEUED(conn->ksnc_sock);
-                if (rc > 0)                     /* sent something? */
-                        conn->ksnc_tx_bufnob += rc; /* account it */
-                
-                if (bufnob < conn->ksnc_tx_bufnob) {
-                        /* allocated send buffer bytes < computed; infer
-                         * something got ACKed */
-                        conn->ksnc_tx_deadline = 
-                                cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
-                        conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
-                        conn->ksnc_tx_bufnob = bufnob;
-                        mb();
-                }
+       nob = rc;
+       LASSERT(nob <= tx->tx_resid);
+       tx->tx_resid -= nob;
 
-                if (rc <= 0) { /* Didn't write anything? */
-                        ksock_sched_t *sched;
+       /* "consume" kiov */
+       do {
+               LASSERT(tx->tx_nkiov > 0);
 
-                        if (rc == 0) /* some stacks return 0 instead of -EAGAIN */
-                                rc = -EAGAIN;
+               if (nob < (int)kiov->kiov_len) {
+                       kiov->kiov_offset += nob;
+                       kiov->kiov_len -= nob;
+                       return rc;
+               }
 
-                        if (rc != -EAGAIN)
-                                break;
+               nob -= (int)kiov->kiov_len;
+               tx->tx_kiov = ++kiov;
+               tx->tx_nkiov--;
+       } while (nob != 0);
 
-                        /* Check if EAGAIN is due to memory pressure */
+       return rc;
+}
 
-                        sched = conn->ksnc_scheduler;
-                        spin_lock_bh (&sched->kss_lock);
-                                
-                        if (!SOCK_TEST_NOSPACE(conn->ksnc_sock) &&
-                            !conn->ksnc_tx_ready) {
-                                /* SOCK_NOSPACE is set when the socket fills
-                                 * and cleared in the write_space callback
-                                 * (which also sets ksnc_tx_ready).  If
-                                 * SOCK_NOSPACE and ksnc_tx_ready are BOTH
-                                 * zero, I didn't fill the socket and
-                                 * write_space won't reschedule me, so I
-                                 * return -ENOMEM to get my caller to retry
-                                 * after a timeout */
-                                rc = -ENOMEM;
-                        }
+static int
+ksocknal_transmit(struct ksock_conn *conn, struct ksock_tx *tx,
+                 struct kvec *scratch_iov)
+{
+       int     rc;
+       int     bufnob;
+
+       if (ksocknal_data.ksnd_stall_tx != 0) {
+               set_current_state(TASK_UNINTERRUPTIBLE);
+               schedule_timeout(cfs_time_seconds(ksocknal_data.ksnd_stall_tx));
+       }
+
+       LASSERT(tx->tx_resid != 0);
+
+       rc = ksocknal_connsock_addref(conn);
+       if (rc != 0) {
+               LASSERT(conn->ksnc_closing);
+               return -ESHUTDOWN;
+       }
+
+       do {
+               if (ksocknal_data.ksnd_enomem_tx > 0) {
+                       /* testing... */
+                       ksocknal_data.ksnd_enomem_tx--;
+                       rc = -EAGAIN;
+               } else if (tx->tx_niov != 0) {
+                       rc = ksocknal_send_iov(conn, tx, scratch_iov);
+               } else {
+                       rc = ksocknal_send_kiov(conn, tx, scratch_iov);
+               }
+
+               bufnob = conn->ksnc_sock->sk->sk_wmem_queued;
+               if (rc > 0)                     /* sent something? */
+                       conn->ksnc_tx_bufnob += rc; /* account it */
+
+               if (bufnob < conn->ksnc_tx_bufnob) {
+                       /* allocated send buffer bytes < computed; infer
+                        * something got ACKed */
+                       conn->ksnc_tx_deadline = ktime_get_seconds() +
+                                                lnet_get_lnd_timeout();
+                       conn->ksnc_peer->ksnp_last_alive = ktime_get_seconds();
+                       conn->ksnc_tx_bufnob = bufnob;
+                       smp_mb();
+               }
+
+               if (rc <= 0) { /* Didn't write anything? */
+                       /* some stacks return 0 instead of -EAGAIN */
+                       if (rc == 0)
+                               rc = -EAGAIN;
+
+                       /* Check if EAGAIN is due to memory pressure */
+                       if (rc == -EAGAIN && ksocknal_lib_memory_pressure(conn))
+                               rc = -ENOMEM;
+
+                       break;
+               }
+
+               /* socket's wmem_queued now includes 'rc' bytes */
+               atomic_sub (rc, &conn->ksnc_tx_nob);
+               rc = 0;
+
+       } while (tx->tx_resid != 0);
+
+       ksocknal_connsock_decref(conn);
+       return rc;
+}
 
-                        spin_unlock_bh (&sched->kss_lock);
-                        break;
-                }
+static int
+ksocknal_recv_iov(struct ksock_conn *conn, struct kvec *scratchiov)
+{
+       struct kvec *iov = conn->ksnc_rx_iov;
+       int     nob;
+       int     rc;
 
-                /* socket's wmem_queued now includes 'rc' bytes */
-                atomic_sub (rc, &conn->ksnc_tx_nob);
-                rc = 0;
+       LASSERT(conn->ksnc_rx_niov > 0);
 
-        } while (tx->tx_resid != 0);
+       /* Never touch conn->ksnc_rx_iov or change connection
+        * status inside ksocknal_lib_recv_iov */
+       rc = ksocknal_lib_recv_iov(conn, scratchiov);
 
-        ksocknal_connsock_decref(conn);
-        return (rc);
-}
+       if (rc <= 0)
+               return rc;
 
-int
-ksocknal_recv_iov (ksock_conn_t *conn)
-{ 
-        struct iovec *iov = conn->ksnc_rx_iov;
-        int     nob;
-        int     rc;
-
-        LASSERT (conn->ksnc_rx_niov > 0);
-
-        /* Never touch conn->ksnc_rx_iov or change connection 
-         * status inside ksocknal_lib_recv_iov */
-        rc = ksocknal_lib_recv_iov(conn); 
-
-        if (rc <= 0) 
-                return (rc); 
-
-        /* received something... */ 
-        nob = rc; 
-        
-        conn->ksnc_peer->ksnp_last_alive = cfs_time_current(); 
-        conn->ksnc_rx_deadline = 
-                cfs_time_shift(*ksocknal_tunables.ksnd_timeout); 
-        mb();                           /* order with setting rx_started */ 
-        conn->ksnc_rx_started = 1; 
-        
-        conn->ksnc_rx_nob_wanted -= nob; 
-        conn->ksnc_rx_nob_left -= nob;
-
-        do { 
-                LASSERT (conn->ksnc_rx_niov > 0); 
-
-                if (nob < iov->iov_len) { 
-                        iov->iov_len -= nob; 
-                        iov->iov_base = (void *)(((unsigned long)iov->iov_base) + nob); 
-                        return (-EAGAIN); 
-                } 
-
-                nob -= iov->iov_len; 
-                conn->ksnc_rx_iov = ++iov; 
-                conn->ksnc_rx_niov--; 
-        } while (nob != 0);
-
-        return (rc);
-}
+       /* received something... */
+       nob = rc;
 
-int
-ksocknal_recv_kiov (ksock_conn_t *conn)
-{
-        lnet_kiov_t   *kiov = conn->ksnc_rx_kiov;
-        int     nob;
-        int     rc;
-        LASSERT (conn->ksnc_rx_nkiov > 0);
-
-        /* Never touch conn->ksnc_rx_kiov or change connection 
-         * status inside ksocknal_lib_recv_iov */
-        rc = ksocknal_lib_recv_kiov(conn); 
-        
-        if (rc <= 0) 
-                return (rc); 
-        
-        /* received something... */ 
-        nob = rc; 
-
-        conn->ksnc_peer->ksnp_last_alive = cfs_time_current(); 
-        conn->ksnc_rx_deadline = 
-                cfs_time_shift(*ksocknal_tunables.ksnd_timeout); 
-        mb();                           /* order with setting rx_started */ 
-        conn->ksnc_rx_started = 1;
-
-        conn->ksnc_rx_nob_wanted -= nob; 
-        conn->ksnc_rx_nob_left -= nob; 
-        
-        do { 
-                LASSERT (conn->ksnc_rx_nkiov > 0); 
-
-                if (nob < kiov->kiov_len) { 
-                        kiov->kiov_offset += nob; 
-                        kiov->kiov_len -= nob; 
-                        return -EAGAIN; 
-                } 
-
-                nob -= kiov->kiov_len; 
-                conn->ksnc_rx_kiov = ++kiov; 
-                conn->ksnc_rx_nkiov--; 
-        } while (nob != 0);
+       conn->ksnc_peer->ksnp_last_alive = ktime_get_seconds();
+       conn->ksnc_rx_deadline = ktime_get_seconds() +
+                                lnet_get_lnd_timeout();
+       smp_mb();                       /* order with setting rx_started */
+       conn->ksnc_rx_started = 1;
 
-        return 1;
+       conn->ksnc_rx_nob_wanted -= nob;
+       conn->ksnc_rx_nob_left -= nob;
+
+       do {
+               LASSERT(conn->ksnc_rx_niov > 0);
+
+               if (nob < (int)iov->iov_len) {
+                       iov->iov_len -= nob;
+                       iov->iov_base += nob;
+                       return -EAGAIN;
+               }
+
+               nob -= iov->iov_len;
+               conn->ksnc_rx_iov = ++iov;
+               conn->ksnc_rx_niov--;
+       } while (nob != 0);
+
+       return rc;
 }
 
-int
-ksocknal_receive (ksock_conn_t *conn) 
+static int
+ksocknal_recv_kiov(struct ksock_conn *conn, struct page **rx_scratch_pgs,
+                  struct kvec *scratch_iov)
 {
-        /* Return 1 on success, 0 on EOF, < 0 on error.
-         * Caller checks ksnc_rx_nob_wanted to determine
-         * progress/completion. */
-        int     rc;
-        ENTRY;
-        
-        if (ksocknal_data.ksnd_stall_rx != 0) {
-                cfs_pause(cfs_time_seconds (ksocknal_data.ksnd_stall_rx));
-        }
+       lnet_kiov_t *kiov = conn->ksnc_rx_kiov;
+       int nob;
+       int rc;
+       LASSERT(conn->ksnc_rx_nkiov > 0);
 
-        rc = ksocknal_connsock_addref(conn);
-        if (rc != 0) {
-                LASSERT (conn->ksnc_closing);
-                return (-ESHUTDOWN);
-        }
+       /* Never touch conn->ksnc_rx_kiov or change connection
+        * status inside ksocknal_lib_recv_iov */
+       rc = ksocknal_lib_recv_kiov(conn, rx_scratch_pgs, scratch_iov);
 
-        for (;;) {
-                if (conn->ksnc_rx_niov != 0)
-                        rc = ksocknal_recv_iov (conn);
-                else
-                        rc = ksocknal_recv_kiov (conn);
-
-                if (rc <= 0) {
-                        /* error/EOF or partial receive */
-                        if (rc == -EAGAIN) {
-                                rc = 1;
-                        } else if (rc == 0 && conn->ksnc_rx_started) {
-                                /* EOF in the middle of a message */
-                                rc = -EPROTO;
-                        }
-                        break;
-                }
+       if (rc <= 0)
+               return rc;
 
-                /* Completed a fragment */
+       /* received something... */
+       nob = rc;
 
-                if (conn->ksnc_rx_nob_wanted == 0) {
-                        rc = 1;
-                        break;
-                }
-        }
+       conn->ksnc_peer->ksnp_last_alive = ktime_get_seconds();
+       conn->ksnc_rx_deadline = ktime_get_seconds() +
+                                lnet_get_lnd_timeout();
+       smp_mb();                       /* order with setting rx_started */
+       conn->ksnc_rx_started = 1;
+
+       conn->ksnc_rx_nob_wanted -= nob;
+       conn->ksnc_rx_nob_left -= nob;
+
+       do {
+               LASSERT(conn->ksnc_rx_nkiov > 0);
 
-        ksocknal_connsock_decref(conn);
-        RETURN (rc);
+               if (nob < (int) kiov->kiov_len) {
+                       kiov->kiov_offset += nob;
+                       kiov->kiov_len -= nob;
+                       return -EAGAIN;
+               }
+
+               nob -= kiov->kiov_len;
+               conn->ksnc_rx_kiov = ++kiov;
+               conn->ksnc_rx_nkiov--;
+       } while (nob != 0);
+
+       return 1;
+}
+
+static int
+ksocknal_receive(struct ksock_conn *conn, struct page **rx_scratch_pgs,
+                struct kvec *scratch_iov)
+{
+       /* Return 1 on success, 0 on EOF, < 0 on error.
+        * Caller checks ksnc_rx_nob_wanted to determine
+        * progress/completion. */
+       int     rc;
+       ENTRY;
+
+       if (ksocknal_data.ksnd_stall_rx != 0) {
+               set_current_state(TASK_UNINTERRUPTIBLE);
+               schedule_timeout(cfs_time_seconds(ksocknal_data.ksnd_stall_rx));
+       }
+
+       rc = ksocknal_connsock_addref(conn);
+       if (rc != 0) {
+               LASSERT(conn->ksnc_closing);
+               return -ESHUTDOWN;
+       }
+
+       for (;;) {
+               if (conn->ksnc_rx_niov != 0)
+                       rc = ksocknal_recv_iov(conn, scratch_iov);
+               else
+                       rc = ksocknal_recv_kiov(conn, rx_scratch_pgs,
+                                                scratch_iov);
+
+               if (rc <= 0) {
+                       /* error/EOF or partial receive */
+                       if (rc == -EAGAIN) {
+                               rc = 1;
+                       } else if (rc == 0 && conn->ksnc_rx_started) {
+                               /* EOF in the middle of a message */
+                               rc = -EPROTO;
+                       }
+                       break;
+               }
+
+               /* Completed a fragment */
+
+               if (conn->ksnc_rx_nob_wanted == 0) {
+                       rc = 1;
+                       break;
+               }
+       }
+
+       ksocknal_connsock_decref(conn);
+       RETURN(rc);
 }
 
 void
-ksocknal_tx_done (lnet_ni_t *ni, ksock_tx_t *tx)
+ksocknal_tx_done(struct lnet_ni *ni, struct ksock_tx *tx, int rc)
 {
-        lnet_msg_t  *lnetmsg = tx->tx_lnetmsg;
-        int          rc = (tx->tx_resid == 0) ? 0 : -EIO;
+       struct lnet_msg *lnetmsg = tx->tx_lnetmsg;
+       enum lnet_msg_hstatus hstatus = tx->tx_hstatus;
         ENTRY;
 
-        LASSERT(ni != NULL || tx->tx_conn != NULL);
+       LASSERT(ni != NULL || tx->tx_conn != NULL);
 
-        if (tx->tx_conn != NULL)
-                ksocknal_conn_decref(tx->tx_conn);
+       if (!rc && (tx->tx_resid != 0 || tx->tx_zc_aborted)) {
+               rc = -EIO;
+               if (hstatus == LNET_MSG_STATUS_OK)
+                       hstatus = LNET_MSG_STATUS_LOCAL_ERROR;
+       }
 
-        if (ni == NULL && tx->tx_conn != NULL) 
-                ni = tx->tx_conn->ksnc_peer->ksnp_ni;
+       if (tx->tx_conn != NULL)
+               ksocknal_conn_decref(tx->tx_conn);
 
-        ksocknal_free_tx (tx);
-        if (lnetmsg != NULL) /* KSOCK_MSG_NOOP go without lnetmsg */
-                lnet_finalize (ni, lnetmsg, rc);
+       ksocknal_free_tx(tx);
+       if (lnetmsg != NULL) { /* KSOCK_MSG_NOOP go without lnetmsg */
+               lnetmsg->msg_health_status = hstatus;
+               lnet_finalize(lnetmsg, rc);
+       }
 
-        EXIT;
+       EXIT;
 }
 
 void
-ksocknal_txlist_done (lnet_ni_t *ni, struct list_head *txlist, int error)
+ksocknal_txlist_done(struct lnet_ni *ni, struct list_head *txlist, int error)
 {
-        ksock_tx_t *tx;
-        
-        while (!list_empty (txlist)) {
-                tx = list_entry (txlist->next, ksock_tx_t, tx_list);
-
-                if (error && tx->tx_lnetmsg != NULL) {
-                        CDEBUG (D_NETERROR, "Deleting packet type %d len %d %s->%s\n",
-                                le32_to_cpu (tx->tx_lnetmsg->msg_hdr.type),
-                                le32_to_cpu (tx->tx_lnetmsg->msg_hdr.payload_length),
-                                libcfs_nid2str(le64_to_cpu(tx->tx_lnetmsg->msg_hdr.src_nid)),
-                                libcfs_nid2str(le64_to_cpu (tx->tx_lnetmsg->msg_hdr.dest_nid)));
-                } else if (error) {
-                        CDEBUG (D_NETERROR, "Deleting noop packet\n");
-                }
-
-                list_del (&tx->tx_list);
-
-                LASSERT (atomic_read(&tx->tx_refcount) == 1);
-                ksocknal_tx_done (ni, tx);
-        }
+       struct ksock_tx *tx;
+
+       while (!list_empty(txlist)) {
+               tx = list_entry(txlist->next, struct ksock_tx, tx_list);
+
+               if (error && tx->tx_lnetmsg != NULL) {
+                       CNETERR("Deleting packet type %d len %d %s->%s\n",
+                               le32_to_cpu(tx->tx_lnetmsg->msg_hdr.type),
+                               le32_to_cpu(tx->tx_lnetmsg->msg_hdr.payload_length),
+                               libcfs_nid2str(le64_to_cpu(tx->tx_lnetmsg->msg_hdr.src_nid)),
+                               libcfs_nid2str(le64_to_cpu(tx->tx_lnetmsg->msg_hdr.dest_nid)));
+               } else if (error) {
+                       CNETERR("Deleting noop packet\n");
+               }
+
+               list_del(&tx->tx_list);
+
+               if (tx->tx_hstatus == LNET_MSG_STATUS_OK) {
+                       if (error == -ETIMEDOUT)
+                               tx->tx_hstatus =
+                                 LNET_MSG_STATUS_LOCAL_TIMEOUT;
+                       else if (error == -ENETDOWN ||
+                                error == -EHOSTUNREACH ||
+                                error == -ENETUNREACH ||
+                                error == -ECONNREFUSED ||
+                                error == -ECONNRESET)
+                               tx->tx_hstatus = LNET_MSG_STATUS_REMOTE_DROPPED;
+                       /*
+                        * for all other errors we don't want to
+                        * retransmit
+                        */
+                       else if (error)
+                               tx->tx_hstatus = LNET_MSG_STATUS_LOCAL_ERROR;
+               }
+
+               LASSERT(atomic_read(&tx->tx_refcount) == 1);
+               ksocknal_tx_done(ni, tx, error);
+       }
 }
 
 static void
-ksocknal_check_zc_req(ksock_tx_t *tx)
+ksocknal_check_zc_req(struct ksock_tx *tx)
 {
-        ksock_conn_t   *conn = tx->tx_conn;
-        ksock_peer_t   *peer = conn->ksnc_peer;
-        lnet_kiov_t    *kiov = tx->tx_kiov;
-        int             nkiov = tx->tx_nkiov;
+       struct ksock_conn *conn = tx->tx_conn;
+       struct ksock_peer_ni *peer_ni = conn->ksnc_peer;
 
-        /* Set tx_msg.ksm_zc_req_cookie to a unique non-zero cookie and add tx
+        /* Set tx_msg.ksm_zc_cookies[0] to a unique non-zero cookie and add tx
          * to ksnp_zc_req_list if some fragment of this message should be sent
-         * zero-copy.  Our peer will send an ACK containing this cookie when
+         * zero-copy.  Our peer_ni will send an ACK containing this cookie when
          * she has received this message to tell us we can signal completion.
-         * tx_msg.ksm_zc_req_cookie remains non-zero while tx is on
+         * tx_msg.ksm_zc_cookies[0] remains non-zero while tx is on
          * ksnp_zc_req_list. */
+        LASSERT (tx->tx_msg.ksm_type != KSOCK_MSG_NOOP);
+        LASSERT (tx->tx_zc_capable);
 
-        if (conn->ksnc_proto != &ksocknal_protocol_v2x ||
+        tx->tx_zc_checked = 1;
+
+        if (conn->ksnc_proto == &ksocknal_protocol_v1x ||
             !conn->ksnc_zc_capable)
                 return;
-        
-        while (nkiov > 0) {
-                if (kiov->kiov_len >= *ksocknal_tunables.ksnd_zc_min_frag)
-                        break;
-                --nkiov;
-                ++kiov;
-        }
 
-        if (nkiov == 0)
-                return;
-        
         /* assign cookie and queue tx to pending list, it will be released when
-         * a matching ack is received. See ksocknal_handle_zc_ack() */
+         * a matching ack is received. See ksocknal_handle_zcack() */
 
         ksocknal_tx_addref(tx);
 
-        spin_lock(&peer->ksnp_lock);
-
-        LASSERT (tx->tx_msg.ksm_zc_req_cookie == 0);
-        tx->tx_msg.ksm_zc_req_cookie = peer->ksnp_zc_next_cookie++; 
-        list_add_tail(&tx->tx_zc_list, &peer->ksnp_zc_req_list);
-
-        spin_unlock(&peer->ksnp_lock);
-}
+       spin_lock(&peer_ni->ksnp_lock);
 
-static void
-ksocknal_unzc_req(ksock_tx_t *tx)
-{
-        ksock_peer_t   *peer = tx->tx_conn->ksnc_peer;
+        /* ZC_REQ is going to be pinned to the peer_ni */
+       tx->tx_deadline = ktime_get_seconds() +
+                         lnet_get_lnd_timeout();
 
-        spin_lock(&peer->ksnp_lock);
+        LASSERT (tx->tx_msg.ksm_zc_cookies[0] == 0);
 
-        if (tx->tx_msg.ksm_zc_req_cookie == 0) {
-                /* Not waiting for an ACK */
-                spin_unlock(&peer->ksnp_lock);
-                return;
-        }
+        tx->tx_msg.ksm_zc_cookies[0] = peer_ni->ksnp_zc_next_cookie++;
 
-        tx->tx_msg.ksm_zc_req_cookie = 0;
-        list_del(&tx->tx_zc_list);
+        if (peer_ni->ksnp_zc_next_cookie == 0)
+                peer_ni->ksnp_zc_next_cookie = SOCKNAL_KEEPALIVE_PING + 1;
 
-        spin_unlock(&peer->ksnp_lock);
+       list_add_tail(&tx->tx_zc_list, &peer_ni->ksnp_zc_req_list);
 
-        ksocknal_tx_decref(tx);
+       spin_unlock(&peer_ni->ksnp_lock);
 }
 
-int
-ksocknal_process_transmit (ksock_conn_t *conn, ksock_tx_t *tx)
+static void
+ksocknal_uncheck_zc_req(struct ksock_tx *tx)
 {
-        int            rc;
+       struct ksock_peer_ni *peer_ni = tx->tx_conn->ksnc_peer;
 
-        if (!tx->tx_checked_zc) {
-                tx->tx_checked_zc = 1;
-                ksocknal_check_zc_req(tx);
-        }
-      
-        rc = ksocknal_transmit (conn, tx);
+       LASSERT(tx->tx_msg.ksm_type != KSOCK_MSG_NOOP);
+       LASSERT(tx->tx_zc_capable);
 
-        CDEBUG (D_NET, "send(%d) %d\n", tx->tx_resid, rc);
+       tx->tx_zc_checked = 0;
 
-        if (tx->tx_resid == 0) {
-                /* Sent everything OK */
-                LASSERT (rc == 0);
+       spin_lock(&peer_ni->ksnp_lock);
 
-                return (0);
-        }
+       if (tx->tx_msg.ksm_zc_cookies[0] == 0) {
+               /* Not waiting for an ACK */
+               spin_unlock(&peer_ni->ksnp_lock);
+               return;
+       }
 
-        if (rc == -EAGAIN)
-                return (rc);
-
-        if (rc == -ENOMEM) {
-                static int counter;
-
-                counter++;   /* exponential backoff warnings */
-                if ((counter & (-counter)) == counter)
-                        CWARN("%u ENOMEM tx %p (%u allocated)\n",
-                              counter, conn, atomic_read(&libcfs_kmemory));
-
-                /* Queue on ksnd_enomem_conns for retry after a timeout */
-                spin_lock_bh (&ksocknal_data.ksnd_reaper_lock);
-
-                /* enomem list takes over scheduler's ref... */
-                LASSERT (conn->ksnc_tx_scheduled);
-                list_add_tail(&conn->ksnc_tx_list,
-                              &ksocknal_data.ksnd_enomem_conns);
-                if (!cfs_time_aftereq(cfs_time_add(cfs_time_current(),
-                                                   SOCKNAL_ENOMEM_RETRY),
-                                   ksocknal_data.ksnd_reaper_waketime))
-                        cfs_waitq_signal (&ksocknal_data.ksnd_reaper_waitq);
-                
-                spin_unlock_bh (&ksocknal_data.ksnd_reaper_lock);
-                return (rc);
-        }
+       tx->tx_msg.ksm_zc_cookies[0] = 0;
+       list_del(&tx->tx_zc_list);
 
-        /* Actual error */
-        LASSERT (rc < 0);
+       spin_unlock(&peer_ni->ksnp_lock);
 
-        if (!conn->ksnc_closing) {
-                switch (rc) {
-                case -ECONNRESET:
-                        LCONSOLE_WARN("Host %u.%u.%u.%u reset our connection "
-                                      "while we were sending data; it may have "
-                                      "rebooted.\n",
-                                      HIPQUAD(conn->ksnc_ipaddr));
-                        break;
-                default:
-                        LCONSOLE_WARN("There was an unexpected network error "
-                                      "while writing to %u.%u.%u.%u: %d.\n",
-                                      HIPQUAD(conn->ksnc_ipaddr), rc);
-                        break;
-                }
-                CDEBUG(D_NET, "[%p] Error %d on write to %s"
-                       " ip %d.%d.%d.%d:%d\n", conn, rc,
-                       libcfs_id2str(conn->ksnc_peer->ksnp_id),
-                       HIPQUAD(conn->ksnc_ipaddr),
-                       conn->ksnc_port);
-        } 
-          
-        ksocknal_unzc_req(tx);
-
-        /* it's not an error if conn is being closed */
-        ksocknal_close_conn_and_siblings (conn, 
-                                          (conn->ksnc_closing) ? 0 : rc);
-
-        return (rc);
+       ksocknal_tx_decref(tx);
 }
 
-void
-ksocknal_launch_connection_locked (ksock_route_t *route)
+static int
+ksocknal_process_transmit(struct ksock_conn *conn, struct ksock_tx *tx,
+                         struct kvec *scratch_iov)
+{
+       int rc;
+       bool error_sim = false;
+
+       if (lnet_send_error_simulation(tx->tx_lnetmsg, &tx->tx_hstatus)) {
+               error_sim = true;
+               rc = -EINVAL;
+               goto simulate_error;
+       }
+
+       if (tx->tx_zc_capable && !tx->tx_zc_checked)
+               ksocknal_check_zc_req(tx);
+
+       rc = ksocknal_transmit(conn, tx, scratch_iov);
+
+       CDEBUG(D_NET, "send(%d) %d\n", tx->tx_resid, rc);
+
+       if (tx->tx_resid == 0) {
+               /* Sent everything OK */
+               LASSERT(rc == 0);
+
+               return 0;
+       }
+
+       if (rc == -EAGAIN)
+               return rc;
+
+       if (rc == -ENOMEM) {
+               static int counter;
+
+               counter++;   /* exponential backoff warnings */
+               if ((counter & (-counter)) == counter)
+                       CWARN("%u ENOMEM tx %p (%u allocated)\n",
+                             counter, conn, atomic_read(&libcfs_kmemory));
+
+               /* Queue on ksnd_enomem_conns for retry after a timeout */
+               spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
+
+               /* enomem list takes over scheduler's ref... */
+               LASSERT(conn->ksnc_tx_scheduled);
+               list_add_tail(&conn->ksnc_tx_list,
+                                 &ksocknal_data.ksnd_enomem_conns);
+               if (ktime_get_seconds() + SOCKNAL_ENOMEM_RETRY <
+                   ksocknal_data.ksnd_reaper_waketime)
+                       wake_up(&ksocknal_data.ksnd_reaper_waitq);
+
+               spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
+
+               /*
+                * set the health status of the message which determines
+                * whether we should retry the transmit
+                */
+               tx->tx_hstatus = LNET_MSG_STATUS_LOCAL_ERROR;
+               return (rc);
+       }
+
+simulate_error:
+
+       /* Actual error */
+       LASSERT(rc < 0);
+
+       if (!error_sim) {
+               /*
+               * set the health status of the message which determines
+               * whether we should retry the transmit
+               */
+               if (rc == -ETIMEDOUT)
+                       tx->tx_hstatus = LNET_MSG_STATUS_REMOTE_TIMEOUT;
+               else
+                       tx->tx_hstatus = LNET_MSG_STATUS_LOCAL_ERROR;
+       }
+
+       if (!conn->ksnc_closing) {
+               switch (rc) {
+               case -ECONNRESET:
+                       LCONSOLE_WARN("Host %pI4h reset our connection "
+                                     "while we were sending data; it may have "
+                                     "rebooted.\n",
+                                     &conn->ksnc_ipaddr);
+                       break;
+               default:
+                       LCONSOLE_WARN("There was an unexpected network error "
+                                     "while writing to %pI4h: %d.\n",
+                                     &conn->ksnc_ipaddr, rc);
+                       break;
+               }
+               CDEBUG(D_NET, "[%p] Error %d on write to %s ip %pI4h:%d\n",
+                      conn, rc, libcfs_id2str(conn->ksnc_peer->ksnp_id),
+                      &conn->ksnc_ipaddr, conn->ksnc_port);
+       }
+
+       if (tx->tx_zc_checked)
+               ksocknal_uncheck_zc_req(tx);
+
+       /* it's not an error if conn is being closed */
+       ksocknal_close_conn_and_siblings(conn,
+                                         (conn->ksnc_closing) ? 0 : rc);
+
+       return rc;
+}
+
+static void
+ksocknal_launch_connection_locked(struct ksock_route *route)
 {
 
         /* called holding write lock on ksnd_global_lock */
@@ -580,147 +648,110 @@ ksocknal_launch_connection_locked (ksock_route_t *route)
         LASSERT (!route->ksnr_scheduled);
         LASSERT (!route->ksnr_connecting);
         LASSERT ((ksocknal_route_mask() & ~route->ksnr_connected) != 0);
-        
+
         route->ksnr_scheduled = 1;              /* scheduling conn for connd */
         ksocknal_route_addref(route);           /* extra ref for connd */
-        
-        spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
-        
-        list_add_tail (&route->ksnr_connd_list,
-                       &ksocknal_data.ksnd_connd_routes);
-        cfs_waitq_signal (&ksocknal_data.ksnd_connd_waitq);
-        
-        spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
+
+       spin_lock_bh(&ksocknal_data.ksnd_connd_lock);
+
+       list_add_tail(&route->ksnr_connd_list,
+                         &ksocknal_data.ksnd_connd_routes);
+       wake_up(&ksocknal_data.ksnd_connd_waitq);
+
+       spin_unlock_bh(&ksocknal_data.ksnd_connd_lock);
 }
 
-ksock_conn_t *
-ksocknal_find_conn_locked (int payload_nob, ksock_peer_t *peer)
+void
+ksocknal_launch_all_connections_locked(struct ksock_peer_ni *peer_ni)
 {
-        struct list_head *tmp;
-        ksock_conn_t     *typed = NULL;
-        int               tnob  = 0;
-        ksock_conn_t     *fallback = NULL;
-        int               fnob     = 0;
-        ksock_conn_t     *conn;
-
-        list_for_each (tmp, &peer->ksnp_conns) {
-                ksock_conn_t *c = list_entry(tmp, ksock_conn_t, ksnc_list);
-                int           hdr_nob = 0;
-#if SOCKNAL_ROUND_ROBIN
-                const int     nob = 0;
-#else
-                int           nob = atomic_read(&c->ksnc_tx_nob) +
-                                        SOCK_WMEM_QUEUED(c->ksnc_sock);
-#endif
-                LASSERT (!c->ksnc_closing);
-                LASSERT(c->ksnc_proto != NULL);
+       struct ksock_route *route;
 
-                if (fallback == NULL || nob < fnob) {
-                        fallback = c;
-                        fnob     = nob;
-                }
+        /* called holding write lock on ksnd_global_lock */
+        for (;;) {
+                /* launch any/all connections that need it */
+                route = ksocknal_find_connectable_route_locked(peer_ni);
+                if (route == NULL)
+                        return;
 
-                if (!*ksocknal_tunables.ksnd_typed_conns)
-                        continue;
+                ksocknal_launch_connection_locked(route);
+        }
+}
 
-                if (payload_nob == 0) {
-                        /* noop packet */
-                        hdr_nob = offsetof(ksock_msg_t, ksm_u);
-                } else {
-                        /* lnet packet */
-                        hdr_nob = (c->ksnc_proto == &ksocknal_protocol_v2x)?
-                                  offsetof(ksock_msg_t, ksm_u.lnetmsg.ksnm_payload):
-                                  sizeof(lnet_hdr_t);
-                }
+struct ksock_conn *
+ksocknal_find_conn_locked(struct ksock_peer_ni *peer_ni, struct ksock_tx *tx, int nonblk)
+{
+       struct list_head *tmp;
+       struct ksock_conn *conn;
+       struct ksock_conn *typed = NULL;
+       struct ksock_conn *fallback = NULL;
+       int tnob = 0;
+       int fnob = 0;
+
+       list_for_each(tmp, &peer_ni->ksnp_conns) {
+               struct ksock_conn *c = list_entry(tmp, struct ksock_conn,
+                                                 ksnc_list);
+               int nob = atomic_read(&c->ksnc_tx_nob) +
+                         c->ksnc_sock->sk->sk_wmem_queued;
+               int rc;
+
+                LASSERT (!c->ksnc_closing);
+                LASSERT (c->ksnc_proto != NULL &&
+                         c->ksnc_proto->pro_match_tx != NULL);
+
+                rc = c->ksnc_proto->pro_match_tx(c, tx, nonblk);
 
-                switch (c->ksnc_type) {
+                switch (rc) {
                 default:
-                        CERROR("ksnc_type bad: %u\n", c->ksnc_type);
                         LBUG();
-                case SOCKLND_CONN_ANY:
-                        break;
-                case SOCKLND_CONN_BULK_IN:
+                case SOCKNAL_MATCH_NO: /* protocol rejected the tx */
                         continue;
-                case SOCKLND_CONN_BULK_OUT:
-                        if ((hdr_nob + payload_nob) < *ksocknal_tunables.ksnd_min_bulk)
-                                continue;
-                        break;
-                case SOCKLND_CONN_CONTROL:
-                        if ((hdr_nob + payload_nob) >= *ksocknal_tunables.ksnd_min_bulk)
-                                continue;
+
+                case SOCKNAL_MATCH_YES: /* typed connection */
+                        if (typed == NULL || tnob > nob ||
+                            (tnob == nob && *ksocknal_tunables.ksnd_round_robin &&
+                            typed->ksnc_tx_last_post > c->ksnc_tx_last_post)) {
+                                typed = c;
+                                tnob  = nob;
+                        }
                         break;
-                }
 
-                if (typed == NULL || nob < tnob) {
-                        typed = c;
-                        tnob  = nob;
+                case SOCKNAL_MATCH_MAY: /* fallback connection */
+                        if (fallback == NULL || fnob > nob ||
+                            (fnob == nob && *ksocknal_tunables.ksnd_round_robin &&
+                            fallback->ksnc_tx_last_post > c->ksnc_tx_last_post)) {
+                                fallback = c;
+                                fnob     = nob;
+                        }
+                        break;
                 }
         }
 
         /* prefer the typed selection */
         conn = (typed != NULL) ? typed : fallback;
 
-#if SOCKNAL_ROUND_ROBIN
-        if (conn != NULL) {
-                /* round-robin all else being equal */
-                list_del (&conn->ksnc_list);
-                list_add_tail (&conn->ksnc_list, &peer->ksnp_conns);
-        }
-#endif
+        if (conn != NULL)
+               conn->ksnc_tx_last_post = ktime_get_seconds();
+
         return conn;
 }
 
 void
-ksocknal_next_mono_tx(ksock_conn_t *conn)
-{
-        ksock_tx_t     *tx = conn->ksnc_tx_mono;
-
-        /* Called holding BH lock: conn->ksnc_scheduler->kss_lock */
-        LASSERT(conn->ksnc_proto == &ksocknal_protocol_v2x);
-        LASSERT(!list_empty(&conn->ksnc_tx_queue));
-        LASSERT(tx != NULL);
-
-        if (tx->tx_list.next == &conn->ksnc_tx_queue) {
-                /* no more packets queued */
-                conn->ksnc_tx_mono = NULL;
-        } else {
-                conn->ksnc_tx_mono = list_entry(tx->tx_list.next, ksock_tx_t, tx_list);
-                LASSERT(conn->ksnc_tx_mono->tx_msg.ksm_type == tx->tx_msg.ksm_type);
-        }
-}
-
-int
-ksocknal_piggyback_zcack(ksock_conn_t *conn, __u64 cookie)
+ksocknal_tx_prep(struct ksock_conn *conn, struct ksock_tx *tx)
 {
-        ksock_tx_t     *tx = conn->ksnc_tx_mono;
-
-        /* Called holding BH lock: conn->ksnc_scheduler->kss_lock */
-
-        if (tx == NULL)
-                return 0;
-
-        if (tx->tx_msg.ksm_type == KSOCK_MSG_NOOP) {
-                /* tx is noop zc-ack, can't piggyback zc-ack cookie */
-                return 0;
-        }
-
-        LASSERT(tx->tx_msg.ksm_type == KSOCK_MSG_LNET);
-        LASSERT(tx->tx_msg.ksm_zc_ack_cookie == 0);
-
-        /* piggyback the zc-ack cookie */
-        tx->tx_msg.ksm_zc_ack_cookie = cookie;
-        ksocknal_next_mono_tx(conn);
+        conn->ksnc_proto->pro_pack(tx);
 
-        return 1;
+       atomic_add (tx->tx_nob, &conn->ksnc_tx_nob);
+        ksocknal_conn_addref(conn); /* +1 ref for tx */
+        tx->tx_conn = conn;
 }
 
 void
-ksocknal_queue_tx_locked (ksock_tx_t *tx, ksock_conn_t *conn)
+ksocknal_queue_tx_locked(struct ksock_tx *tx, struct ksock_conn *conn)
 {
-        ksock_sched_t *sched = conn->ksnc_scheduler;
-        ksock_msg_t   *msg = &tx->tx_msg;
-        ksock_tx_t    *ztx;
-        int            bufnob = 0;
+       struct ksock_sched *sched = conn->ksnc_scheduler;
+       struct ksock_msg *msg = &tx->tx_msg;
+       struct ksock_tx *ztx = NULL;
+       int bufnob = 0;
 
         /* called holding global lock (read or irq-write) and caller may
          * not have dropped this lock between finding conn and calling me,
@@ -728,133 +759,89 @@ ksocknal_queue_tx_locked (ksock_tx_t *tx, ksock_conn_t *conn)
          * ksnc_sock... */
         LASSERT(!conn->ksnc_closing);
 
-        CDEBUG (D_NET, "Sending to %s ip %d.%d.%d.%d:%d\n", 
-                libcfs_id2str(conn->ksnc_peer->ksnp_id),
-                HIPQUAD(conn->ksnc_ipaddr),
-                conn->ksnc_port);
+       CDEBUG(D_NET, "Sending to %s ip %pI4h:%d\n",
+              libcfs_id2str(conn->ksnc_peer->ksnp_id),
+              &conn->ksnc_ipaddr, conn->ksnc_port);
 
-        tx->tx_checked_zc = 0;
-        conn->ksnc_proto->pro_pack(tx);
+        ksocknal_tx_prep(conn, tx);
 
         /* Ensure the frags we've been given EXACTLY match the number of
          * bytes we want to send.  Many TCP/IP stacks disregard any total
-         * size parameters passed to them and just look at the frags. 
+        * size parameters passed to them and just look at the frags.
          *
          * We always expect at least 1 mapped fragment containing the
          * complete ksocknal message header. */
         LASSERT (lnet_iov_nob (tx->tx_niov, tx->tx_iov) +
-                 lnet_kiov_nob (tx->tx_nkiov, tx->tx_kiov) == tx->tx_nob);
+                 lnet_kiov_nob(tx->tx_nkiov, tx->tx_kiov) ==
+                 (unsigned int)tx->tx_nob);
         LASSERT (tx->tx_niov >= 1);
         LASSERT (tx->tx_resid == tx->tx_nob);
 
         CDEBUG (D_NET, "Packet %p type %d, nob %d niov %d nkiov %d\n",
-                tx, (tx->tx_lnetmsg != NULL)? tx->tx_lnetmsg->msg_hdr.type: 
-                                              KSOCK_MSG_NOOP, 
+                tx, (tx->tx_lnetmsg != NULL) ? tx->tx_lnetmsg->msg_hdr.type:
+                                               KSOCK_MSG_NOOP,
                 tx->tx_nob, tx->tx_niov, tx->tx_nkiov);
-        
-        atomic_add (tx->tx_nob, &conn->ksnc_tx_nob);
-        tx->tx_conn = conn;
-        ksocknal_conn_addref(conn); /* +1 ref for tx */
 
-        /* 
-         * NB Darwin: SOCK_WMEM_QUEUED()->sock_getsockopt() will take
-         * a blockable lock(socket lock), so SOCK_WMEM_QUEUED can't be
-         * put in spinlock. 
-         */
-        bufnob = SOCK_WMEM_QUEUED(conn->ksnc_sock);
-        spin_lock_bh (&sched->kss_lock);
-
-        if (list_empty(&conn->ksnc_tx_queue) && bufnob == 0) {
-                /* First packet starts the timeout */
-                conn->ksnc_tx_deadline = 
-                        cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
-                conn->ksnc_tx_bufnob = 0;
-                mb();    /* order with adding to tx_queue */
-        }
+       bufnob = conn->ksnc_sock->sk->sk_wmem_queued;
+       spin_lock_bh(&sched->kss_lock);
 
-        ztx = NULL;
+       if (list_empty(&conn->ksnc_tx_queue) && bufnob == 0) {
+               /* First packet starts the timeout */
+               conn->ksnc_tx_deadline = ktime_get_seconds() +
+                                        lnet_get_lnd_timeout();
+               if (conn->ksnc_tx_bufnob > 0) /* something got ACKed */
+                       conn->ksnc_peer->ksnp_last_alive = ktime_get_seconds();
+               conn->ksnc_tx_bufnob = 0;
+               smp_mb(); /* order with adding to tx_queue */
+       }
 
-        if (msg->ksm_type == KSOCK_MSG_NOOP) {
-                /* The packet is noop ZC ACK, try to piggyback the ack_cookie
-                 * on a normal packet so I don't need to send it */
-                LASSERT(msg->ksm_zc_req_cookie == 0);
-                LASSERT(msg->ksm_zc_ack_cookie != 0);
+       if (msg->ksm_type == KSOCK_MSG_NOOP) {
+               /* The packet is noop ZC ACK, try to piggyback the ack_cookie
+                * on a normal packet so I don't need to send it */
+                LASSERT (msg->ksm_zc_cookies[1] != 0);
+                LASSERT (conn->ksnc_proto->pro_queue_tx_zcack != NULL);
 
-                if (conn->ksnc_tx_mono != NULL) {
-                        if (ksocknal_piggyback_zcack(conn, msg->ksm_zc_ack_cookie)) {
-                                /* zc-ack cookie is piggybacked */
-                                atomic_sub (tx->tx_nob, &conn->ksnc_tx_nob);
-                                ztx = tx;       /* Put to freelist later */
-                        } else {
-                                /* no packet can piggyback zc-ack cookie */
-                                list_add_tail (&tx->tx_list, &conn->ksnc_tx_queue);
-                        }
-                } else {
-                        /* It's the first mono-packet */
-                        conn->ksnc_tx_mono = tx;
-                        list_add_tail (&tx->tx_list, &conn->ksnc_tx_queue);
-                }
+                if (conn->ksnc_proto->pro_queue_tx_zcack(conn, tx, 0))
+                        ztx = tx; /* ZC ACK piggybacked on ztx release tx later */
 
         } else {
                 /* It's a normal packet - can it piggback a noop zc-ack that
                  * has been queued already? */
-                LASSERT(msg->ksm_zc_ack_cookie == 0);
+                LASSERT (msg->ksm_zc_cookies[1] == 0);
+                LASSERT (conn->ksnc_proto->pro_queue_tx_msg != NULL);
 
-                if (conn->ksnc_proto == &ksocknal_protocol_v2x &&  /* V2.x packet */
-                    conn->ksnc_tx_mono != NULL) {          
-                        if (conn->ksnc_tx_mono->tx_msg.ksm_type == KSOCK_MSG_NOOP) {
-                                /* There is a noop zc-ack can be piggybacked */
-                                ztx = conn->ksnc_tx_mono;
-
-                                msg->ksm_zc_ack_cookie = ztx->tx_msg.ksm_zc_ack_cookie;
-                                ksocknal_next_mono_tx(conn);
-
-                                /* use tx to replace the noop zc-ack packet, ztx will
-                                 * be put to freelist later */
-                                list_add(&tx->tx_list, &ztx->tx_list);
-                                list_del(&ztx->tx_list);
-
-                                atomic_sub (ztx->tx_nob, &conn->ksnc_tx_nob);
-                        } else {
-                                /* no noop zc-ack packet, just enqueue it */
-                                LASSERT(conn->ksnc_tx_mono->tx_msg.ksm_type == KSOCK_MSG_LNET);
-                                list_add_tail (&tx->tx_list, &conn->ksnc_tx_queue);
-                        }
-
-                } else if (conn->ksnc_proto == &ksocknal_protocol_v2x) {
-                        /* it's the first mono-packet, enqueue it */
-                        conn->ksnc_tx_mono = tx;
-                        list_add_tail (&tx->tx_list, &conn->ksnc_tx_queue);
-                } else {
-                        /* V1.x packet, just enqueue it */
-                        list_add_tail (&tx->tx_list, &conn->ksnc_tx_queue);
-                }
+                ztx = conn->ksnc_proto->pro_queue_tx_msg(conn, tx);
+                /* ztx will be released later */
         }
 
-        if (ztx != NULL)
-                list_add_tail(&ztx->tx_list, &sched->kss_zombie_noop_txs);
-                
-        if (conn->ksnc_tx_ready &&      /* able to send */
-            !conn->ksnc_tx_scheduled) { /* not scheduled to send */
-                /* +1 ref for scheduler */
-                ksocknal_conn_addref(conn);
-                list_add_tail (&conn->ksnc_tx_list, 
-                               &sched->kss_tx_conns);
-                conn->ksnc_tx_scheduled = 1;
-                cfs_waitq_signal (&sched->kss_waitq);
+        if (ztx != NULL) {
+               atomic_sub (ztx->tx_nob, &conn->ksnc_tx_nob);
+               list_add_tail(&ztx->tx_list, &sched->kss_zombie_noop_txs);
         }
 
-        spin_unlock_bh (&sched->kss_lock);
+       if (conn->ksnc_tx_ready &&      /* able to send */
+           !conn->ksnc_tx_scheduled) { /* not scheduled to send */
+               /* +1 ref for scheduler */
+               ksocknal_conn_addref(conn);
+               list_add_tail(&conn->ksnc_tx_list,
+                                  &sched->kss_tx_conns);
+               conn->ksnc_tx_scheduled = 1;
+               wake_up(&sched->kss_waitq);
+       }
+
+       spin_unlock_bh(&sched->kss_lock);
 }
 
-ksock_route_t *
-ksocknal_find_connectable_route_locked (ksock_peer_t *peer)
+
+struct ksock_route *
+ksocknal_find_connectable_route_locked(struct ksock_peer_ni *peer_ni)
 {
-        struct list_head  *tmp;
-        ksock_route_t     *route;
-        
-        list_for_each (tmp, &peer->ksnp_routes) {
-                route = list_entry (tmp, ksock_route_t, ksnr_list);
+       time64_t now = ktime_get_seconds();
+       struct list_head *tmp;
+       struct ksock_route *route;
+
+       list_for_each(tmp, &peer_ni->ksnp_routes) {
+               route = list_entry(tmp, struct ksock_route, ksnr_list);
 
                 LASSERT (!route->ksnr_connecting || route->ksnr_scheduled);
 
@@ -865,144 +852,147 @@ ksocknal_find_connectable_route_locked (ksock_peer_t *peer)
                 if ((ksocknal_route_mask() & ~route->ksnr_connected) == 0)
                         continue;
 
-                /* too soon to retry this guy? */
                 if (!(route->ksnr_retry_interval == 0 || /* first attempt */
-                      cfs_time_aftereq (cfs_time_current(), 
-                                        route->ksnr_timeout)))
+                     now >= route->ksnr_timeout)) {
+                        CDEBUG(D_NET,
+                              "Too soon to retry route %pI4h "
+                              "(cnted %d, interval %lld, %lld secs later)\n",
+                              &route->ksnr_ipaddr,
+                               route->ksnr_connected,
+                               route->ksnr_retry_interval,
+                              route->ksnr_timeout - now);
                         continue;
-                
+                }
+
                 return (route);
         }
-        
+
         return (NULL);
 }
 
-ksock_route_t *
-ksocknal_find_connecting_route_locked (ksock_peer_t *peer)
+struct ksock_route *
+ksocknal_find_connecting_route_locked(struct ksock_peer_ni *peer_ni)
 {
-        struct list_head  *tmp;
-        ksock_route_t     *route;
+       struct list_head *tmp;
+       struct ksock_route *route;
 
-        list_for_each (tmp, &peer->ksnp_routes) {
-                route = list_entry (tmp, ksock_route_t, ksnr_list);
+       list_for_each(tmp, &peer_ni->ksnp_routes) {
+               route = list_entry(tmp, struct ksock_route, ksnr_list);
 
                 LASSERT (!route->ksnr_connecting || route->ksnr_scheduled);
-                
+
                 if (route->ksnr_scheduled)
                         return (route);
         }
-        
+
         return (NULL);
 }
 
 int
-ksocknal_launch_packet (lnet_ni_t *ni, ksock_tx_t *tx, lnet_process_id_t id)
+ksocknal_launch_packet(struct lnet_ni *ni, struct ksock_tx *tx,
+                      struct lnet_process_id id)
 {
-        ksock_peer_t     *peer;
-        ksock_conn_t     *conn;
-        ksock_route_t    *route;
-        rwlock_t         *g_lock;
-        int               retry;
-        int               rc;
-        
+       struct ksock_peer_ni *peer_ni;
+       struct ksock_conn *conn;
+       rwlock_t *g_lock;
+       int retry;
+       int rc;
+
         LASSERT (tx->tx_conn == NULL);
-        LASSERT (tx->tx_lnetmsg != NULL);
 
         g_lock = &ksocknal_data.ksnd_global_lock;
-        
+
         for (retry = 0;; retry = 1) {
-#if !SOCKNAL_ROUND_ROBIN
-                read_lock (g_lock);
-                peer = ksocknal_find_peer_locked(ni, id);
-                if (peer != NULL) {
-                        if (ksocknal_find_connectable_route_locked(peer) == NULL) {
-                                conn = ksocknal_find_conn_locked (tx->tx_lnetmsg->msg_len, peer);
+               read_lock(g_lock);
+                peer_ni = ksocknal_find_peer_locked(ni, id);
+                if (peer_ni != NULL) {
+                        if (ksocknal_find_connectable_route_locked(peer_ni) == NULL) {
+                                conn = ksocknal_find_conn_locked(peer_ni, tx, tx->tx_nonblk);
                                 if (conn != NULL) {
                                         /* I've got no routes that need to be
                                          * connecting and I do have an actual
                                          * connection... */
                                         ksocknal_queue_tx_locked (tx, conn);
-                                        read_unlock (g_lock);
+                                       read_unlock(g_lock);
                                         return (0);
                                 }
                         }
                 }
+
                 /* I'll need a write lock... */
-                read_unlock (g_lock);
-#endif
-                write_lock_bh (g_lock);
+               read_unlock(g_lock);
 
-                peer = ksocknal_find_peer_locked(ni, id);
-                if (peer != NULL) 
+               write_lock_bh(g_lock);
+
+                peer_ni = ksocknal_find_peer_locked(ni, id);
+                if (peer_ni != NULL)
                         break;
-                
-                write_unlock_bh (g_lock);
+
+               write_unlock_bh(g_lock);
 
                 if ((id.pid & LNET_PID_USERFLAG) != 0) {
                         CERROR("Refusing to create a connection to "
                                "userspace process %s\n", libcfs_id2str(id));
                         return -EHOSTUNREACH;
                 }
-                
+
                 if (retry) {
-                        CERROR("Can't find peer %s\n", libcfs_id2str(id));
+                        CERROR("Can't find peer_ni %s\n", libcfs_id2str(id));
                         return -EHOSTUNREACH;
                 }
-                
-                rc = ksocknal_add_peer(ni, id, 
+
+                rc = ksocknal_add_peer(ni, id,
                                        LNET_NIDADDR(id.nid),
                                        lnet_acceptor_port());
                 if (rc != 0) {
-                        CERROR("Can't add peer %s: %d\n",
+                        CERROR("Can't add peer_ni %s: %d\n",
                                libcfs_id2str(id), rc);
                         return rc;
                 }
         }
 
-        for (;;) {
-                /* launch any/all connections that need it */
-                route = ksocknal_find_connectable_route_locked (peer);
-                if (route == NULL)
-                        break;
-
-                ksocknal_launch_connection_locked (route);
-        }
+        ksocknal_launch_all_connections_locked(peer_ni);
 
-        conn = ksocknal_find_conn_locked (tx->tx_lnetmsg->msg_len, peer);
+        conn = ksocknal_find_conn_locked(peer_ni, tx, tx->tx_nonblk);
         if (conn != NULL) {
                 /* Connection exists; queue message on it */
                 ksocknal_queue_tx_locked (tx, conn);
-                write_unlock_bh (g_lock);
+               write_unlock_bh(g_lock);
                 return (0);
         }
 
-        if (peer->ksnp_accepting > 0 ||
-            ksocknal_find_connecting_route_locked (peer) != NULL) {
+        if (peer_ni->ksnp_accepting > 0 ||
+            ksocknal_find_connecting_route_locked (peer_ni) != NULL) {
+                /* the message is going to be pinned to the peer_ni */
+               tx->tx_deadline = ktime_get_seconds() +
+                                 lnet_get_lnd_timeout();
+
                 /* Queue the message until a connection is established */
-                list_add_tail (&tx->tx_list, &peer->ksnp_tx_queue);
-                write_unlock_bh (g_lock);
+               list_add_tail(&tx->tx_list, &peer_ni->ksnp_tx_queue);
+               write_unlock_bh(g_lock);
                 return 0;
         }
-        
-        write_unlock_bh (g_lock);
+
+       write_unlock_bh(g_lock);
 
         /* NB Routes may be ignored if connections to them failed recently */
-        CDEBUG(D_NETERROR, "No usable routes to %s\n", libcfs_id2str(id));
+        CNETERR("No usable routes to %s\n", libcfs_id2str(id));
+       tx->tx_hstatus = LNET_MSG_STATUS_REMOTE_ERROR;
         return (-EHOSTUNREACH);
 }
 
 int
-ksocknal_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
+ksocknal_send(struct lnet_ni *ni, void *private, struct lnet_msg *lntmsg)
 {
-        int               type = lntmsg->msg_type; 
-        lnet_process_id_t target = lntmsg->msg_target;
-        unsigned int      payload_niov = lntmsg->msg_niov; 
-        struct iovec     *payload_iov = lntmsg->msg_iov; 
+       int mpflag = 1;
+       int type = lntmsg->msg_type;
+       struct lnet_process_id target = lntmsg->msg_target;
+        unsigned int      payload_niov = lntmsg->msg_niov;
+       struct kvec *payload_iov = lntmsg->msg_iov;
         lnet_kiov_t      *payload_kiov = lntmsg->msg_kiov;
         unsigned int      payload_offset = lntmsg->msg_offset;
         unsigned int      payload_nob = lntmsg->msg_len;
-        ksock_tx_t       *tx;
+       struct ksock_tx *tx;
         int               desc_size;
         int               rc;
 
@@ -1012,23 +1002,27 @@ ksocknal_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
         CDEBUG(D_NET, "sending %u bytes in %d frags to %s\n",
                payload_nob, payload_niov, libcfs_id2str(target));
 
-        LASSERT (payload_nob == 0 || payload_niov > 0);
-        LASSERT (payload_niov <= LNET_MAX_IOV);
-        /* payload is either all vaddrs or all pages */
-        LASSERT (!(payload_kiov != NULL && payload_iov != NULL));
-        LASSERT (!in_interrupt ());
-        
-        if (payload_iov != NULL)
-                desc_size = offsetof(ksock_tx_t, 
-                                     tx_frags.virt.iov[1 + payload_niov]);
-        else
-                desc_size = offsetof(ksock_tx_t, 
-                                     tx_frags.paged.kiov[payload_niov]);
-        
-        tx = ksocknal_alloc_tx(desc_size);
+       LASSERT (payload_nob == 0 || payload_niov > 0);
+       LASSERT (payload_niov <= LNET_MAX_IOV);
+       /* payload is either all vaddrs or all pages */
+       LASSERT (!(payload_kiov != NULL && payload_iov != NULL));
+       LASSERT (!in_interrupt ());
+
+       if (payload_iov != NULL)
+               desc_size = offsetof(struct ksock_tx,
+                                    tx_frags.virt.iov[1 + payload_niov]);
+       else
+               desc_size = offsetof(struct ksock_tx,
+                                    tx_frags.paged.kiov[payload_niov]);
+
+        if (lntmsg->msg_vmflush)
+                mpflag = cfs_memory_pressure_get_and_set();
+        tx = ksocknal_alloc_tx(KSOCK_MSG_LNET, desc_size);
         if (tx == NULL) {
                 CERROR("Can't allocate tx desc type %d size %d\n",
                        type, desc_size);
+                if (lntmsg->msg_vmflush)
+                        cfs_memory_pressure_restore(mpflag);
                 return (-ENOMEM);
         }
 
@@ -1039,7 +1033,7 @@ ksocknal_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
                 tx->tx_kiov = NULL;
                 tx->tx_nkiov = 0;
                 tx->tx_iov = tx->tx_frags.virt.iov;
-                tx->tx_niov = 1 + 
+                tx->tx_niov = 1 +
                               lnet_extract_iov(payload_niov, &tx->tx_iov[1],
                                                payload_niov, payload_iov,
                                                payload_offset, payload_nob);
@@ -1050,49 +1044,58 @@ ksocknal_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
                 tx->tx_nkiov = lnet_extract_kiov(payload_niov, tx->tx_kiov,
                                                  payload_niov, payload_kiov,
                                                  payload_offset, payload_nob);
+
+                if (payload_nob >= *ksocknal_tunables.ksnd_zc_min_payload)
+                        tx->tx_zc_capable = 1;
         }
 
-        ksocknal_init_msg(&tx->tx_msg, KSOCK_MSG_LNET);
+       tx->tx_msg.ksm_csum = 0;
+       tx->tx_msg.ksm_type = KSOCK_MSG_LNET;
+       tx->tx_msg.ksm_zc_cookies[0] = 0;
+       tx->tx_msg.ksm_zc_cookies[1] = 0;
 
         /* The first fragment will be set later in pro_pack */
         rc = ksocknal_launch_packet(ni, tx, target);
+        if (!mpflag)
+                cfs_memory_pressure_restore(mpflag);
+
         if (rc == 0)
                 return (0);
-        
+
+       lntmsg->msg_health_status = tx->tx_hstatus;
         ksocknal_free_tx(tx);
         return (-EIO);
 }
 
 int
-ksocknal_thread_start (int (*fn)(void *arg), void *arg)
+ksocknal_thread_start(int (*fn)(void *arg), void *arg, char *name)
 {
-        long          pid = cfs_kernel_thread (fn, arg, 0);
+       struct task_struct *task = kthread_run(fn, arg, name);
 
-        if (pid < 0)
-                return ((int)pid);
+       if (IS_ERR(task))
+               return PTR_ERR(task);
 
-        write_lock_bh (&ksocknal_data.ksnd_global_lock);
-        ksocknal_data.ksnd_nthreads++;
-        write_unlock_bh (&ksocknal_data.ksnd_global_lock);
-        return (0);
+       write_lock_bh(&ksocknal_data.ksnd_global_lock);
+       ksocknal_data.ksnd_nthreads++;
+       write_unlock_bh(&ksocknal_data.ksnd_global_lock);
+       return 0;
 }
 
 void
 ksocknal_thread_fini (void)
 {
-        write_lock_bh (&ksocknal_data.ksnd_global_lock);
+       write_lock_bh(&ksocknal_data.ksnd_global_lock);
         ksocknal_data.ksnd_nthreads--;
-        write_unlock_bh (&ksocknal_data.ksnd_global_lock);
+       write_unlock_bh(&ksocknal_data.ksnd_global_lock);
 }
 
 int
-ksocknal_new_packet (ksock_conn_t *conn, int nob_to_skip)
+ksocknal_new_packet(struct ksock_conn *conn, int nob_to_skip)
 {
         static char ksocknal_slop_buffer[4096];
-
-        int            nob;
-        unsigned int   niov;
-        int            skipped;
+       int nob;
+       unsigned int niov;
+       int skipped;
 
         LASSERT(conn->ksnc_proto != NULL);
 
@@ -1101,44 +1104,36 @@ ksocknal_new_packet (ksock_conn_t *conn, int nob_to_skip)
                 ksocknal_lib_eager_ack(conn);
         }
 
-        if (nob_to_skip == 0) {         /* right at next packet boundary now */
-                conn->ksnc_rx_started = 0;
-                mb ();                          /* racing with timeout thread */
-                
-                switch (conn->ksnc_proto->pro_version) {
-                case  KSOCK_PROTO_V2:
+       if (nob_to_skip == 0) {         /* right at next packet boundary now */
+               conn->ksnc_rx_started = 0;
+               smp_mb();                       /* racing with timeout thread */
+
+               switch (conn->ksnc_proto->pro_version) {
+               case  KSOCK_PROTO_V2:
+               case  KSOCK_PROTO_V3:
                         conn->ksnc_rx_state = SOCKNAL_RX_KSM_HEADER;
-                        conn->ksnc_rx_iov = (struct iovec *)&conn->ksnc_rx_iov_space;
+                       conn->ksnc_rx_iov = (struct kvec *)&conn->ksnc_rx_iov_space;
                         conn->ksnc_rx_iov[0].iov_base = (char *)&conn->ksnc_msg;
 
-                        if (conn->ksnc_type == SOCKLND_CONN_BULK_IN) {
-                                /* always expect lnet_hdr_t to avoid extra-read for better performance */
-                                conn->ksnc_rx_nob_wanted = offsetof(ksock_msg_t, ksm_u.lnetmsg.ksnm_payload);
-                                conn->ksnc_rx_nob_left = offsetof(ksock_msg_t, ksm_u.lnetmsg.ksnm_payload);
-                                conn->ksnc_rx_iov[0].iov_len  = offsetof(ksock_msg_t, ksm_u.lnetmsg.ksnm_payload);
-
-                        } else {
-                                /* can't make sure if it's noop or not */
-                                conn->ksnc_rx_nob_wanted = offsetof(ksock_msg_t, ksm_u);
-                                conn->ksnc_rx_nob_left = offsetof(ksock_msg_t, ksm_u);
-                                conn->ksnc_rx_iov[0].iov_len  = offsetof(ksock_msg_t, ksm_u);
-                        } 
+                       conn->ksnc_rx_nob_wanted = offsetof(struct ksock_msg, ksm_u);
+                       conn->ksnc_rx_nob_left = offsetof(struct ksock_msg, ksm_u);
+                       conn->ksnc_rx_iov[0].iov_len  = offsetof(struct ksock_msg, ksm_u);
                         break;
 
-                case KSOCK_PROTO_V1:
-                        /* Receiving bare lnet_hdr_t */
-                        conn->ksnc_rx_state = SOCKNAL_RX_LNET_HEADER;
-                        conn->ksnc_rx_nob_wanted = sizeof(lnet_hdr_t);
-                        conn->ksnc_rx_nob_left = sizeof(lnet_hdr_t);
+               case KSOCK_PROTO_V1:
+                       /* Receiving bare struct lnet_hdr */
+                       conn->ksnc_rx_state = SOCKNAL_RX_LNET_HEADER;
+                       conn->ksnc_rx_nob_wanted = sizeof(struct lnet_hdr);
+                       conn->ksnc_rx_nob_left = sizeof(struct lnet_hdr);
 
-                        conn->ksnc_rx_iov = (struct iovec *)&conn->ksnc_rx_iov_space;
-                        conn->ksnc_rx_iov[0].iov_base = (char *)&conn->ksnc_msg.ksm_u.lnetmsg;
-                        conn->ksnc_rx_iov[0].iov_len  = sizeof (lnet_hdr_t);
+                       conn->ksnc_rx_iov = (struct kvec *)&conn->ksnc_rx_iov_space;
+                       conn->ksnc_rx_iov[0].iov_base = (char *)&conn->ksnc_msg.ksm_u.lnetmsg;
+                       conn->ksnc_rx_iov[0].iov_len = sizeof(struct lnet_hdr);
                         break;
 
                 default:
                         LBUG ();
-                } 
+                }
                 conn->ksnc_rx_niov = 1;
 
                 conn->ksnc_rx_kiov = NULL;
@@ -1152,7 +1147,7 @@ ksocknal_new_packet (ksock_conn_t *conn, int nob_to_skip)
 
         conn->ksnc_rx_state = SOCKNAL_RX_SLOP;
         conn->ksnc_rx_nob_left = nob_to_skip;
-        conn->ksnc_rx_iov = (struct iovec *)&conn->ksnc_rx_iov_space;
+       conn->ksnc_rx_iov = (struct kvec *)&conn->ksnc_rx_iov_space;
         skipped = 0;
         niov = 0;
 
@@ -1166,7 +1161,7 @@ ksocknal_new_packet (ksock_conn_t *conn, int nob_to_skip)
                 nob_to_skip -=nob;
 
         } while (nob_to_skip != 0 &&    /* mustn't overflow conn's rx iov */
-                 niov < sizeof(conn->ksnc_rx_iov_space) / sizeof (struct iovec));
+                niov < sizeof(conn->ksnc_rx_iov_space) / sizeof(struct kvec));
 
         conn->ksnc_rx_niov = niov;
         conn->ksnc_rx_kiov = NULL;
@@ -1175,152 +1170,80 @@ ksocknal_new_packet (ksock_conn_t *conn, int nob_to_skip)
         return (0);
 }
 
-/* (Sink) handle incoming ZC request from sender */
 static int
-ksocknal_handle_zc_req(ksock_peer_t *peer, __u64 cookie)
+ksocknal_process_receive(struct ksock_conn *conn,
+                        struct page **rx_scratch_pgs,
+                        struct kvec *scratch_iov)
 {
-        ksock_conn_t   *conn;
-        ksock_tx_t     *tx;
-        ksock_sched_t  *sched;
-        int             rc;
-
-        read_lock (&ksocknal_data.ksnd_global_lock);
-
-        conn = ksocknal_find_conn_locked (0, peer);
-        if (conn == NULL) {
-                read_unlock (&ksocknal_data.ksnd_global_lock);
-                CERROR("Can't find connection to send zcack.\n");
-                return -ECONNRESET;
-        }
-
-        sched = conn->ksnc_scheduler;
-
-        spin_lock_bh (&sched->kss_lock);
-        rc = ksocknal_piggyback_zcack(conn, cookie);
-        spin_unlock_bh (&sched->kss_lock);
-
-        read_unlock (&ksocknal_data.ksnd_global_lock);
-        if (rc) {
-                /* Ack cookie is piggybacked */
-                return 0;
-        }
+       struct lnet_hdr *lhdr;
+       struct lnet_process_id *id;
+       int rc;
+
+       LASSERT (atomic_read(&conn->ksnc_conn_refcount) > 0);
+
+       /* NB: sched lock NOT held */
+       /* SOCKNAL_RX_LNET_HEADER is here for backward compatibility */
+       LASSERT(conn->ksnc_rx_state == SOCKNAL_RX_KSM_HEADER ||
+               conn->ksnc_rx_state == SOCKNAL_RX_LNET_PAYLOAD ||
+               conn->ksnc_rx_state == SOCKNAL_RX_LNET_HEADER ||
+               conn->ksnc_rx_state == SOCKNAL_RX_SLOP);
+ again:
+       if (conn->ksnc_rx_nob_wanted != 0) {
+               rc = ksocknal_receive(conn, rx_scratch_pgs,
+                                     scratch_iov);
 
-        tx = ksocknal_alloc_tx(KSOCK_NOOP_TX_SIZE);
-        if (tx == NULL) {
-                CERROR("Can't allocate noop tx desc\n");
-                return -ENOMEM;
-        }
+               if (rc <= 0) {
+                       struct lnet_process_id ksnp_id;
 
-        tx->tx_conn     = NULL;
-        tx->tx_lnetmsg  = NULL;
-        tx->tx_kiov     = NULL;
-        tx->tx_nkiov    = 0;
-        tx->tx_iov      = tx->tx_frags.virt.iov;
-        tx->tx_niov     = 1;
+                       ksnp_id = conn->ksnc_peer->ksnp_id;
 
-        ksocknal_init_msg(&tx->tx_msg, KSOCK_MSG_NOOP);
-        tx->tx_msg.ksm_zc_ack_cookie = cookie; /* incoming cookie */
+                       LASSERT(rc != -EAGAIN);
+                       if (rc == 0)
+                               CDEBUG(D_NET, "[%p] EOF from %s "
+                                      "ip %pI4h:%d\n", conn,
+                                       libcfs_id2str(ksnp_id),
+                                       &conn->ksnc_ipaddr,
+                                        conn->ksnc_port);
+                       else if (!conn->ksnc_closing)
+                               CERROR("[%p] Error %d on read from %s "
+                                      "ip %pI4h:%d\n", conn, rc,
+                                      libcfs_id2str(ksnp_id),
+                                      &conn->ksnc_ipaddr,
+                                      conn->ksnc_port);
 
-        read_lock (&ksocknal_data.ksnd_global_lock);
+                        /* it's not an error if conn is being closed */
+                        ksocknal_close_conn_and_siblings (conn,
+                                                          (conn->ksnc_closing) ? 0 : rc);
+                        return (rc == 0 ? -ESHUTDOWN : rc);
+                }
 
-        conn = ksocknal_find_conn_locked (0, peer);
-        if (conn == NULL) {
-                read_unlock (&ksocknal_data.ksnd_global_lock);
-                ksocknal_free_tx(tx);
-                CERROR("Can't find connection to send zcack.\n");
-                return -ECONNRESET;
-        }
-        ksocknal_queue_tx_locked(tx, conn);
-
-        read_unlock (&ksocknal_data.ksnd_global_lock);
-
-        return 0;
-}
-
-/* (Sender) handle ZC_ACK from sink */
-static int
-ksocknal_handle_zc_ack(ksock_peer_t *peer, __u64 cookie)
-{
-        ksock_tx_t             *tx;
-        struct list_head       *ctmp;
-
-        spin_lock(&peer->ksnp_lock);
-
-        list_for_each(ctmp, &peer->ksnp_zc_req_list) {
-                tx = list_entry (ctmp, ksock_tx_t, tx_zc_list); 
-                if (tx->tx_msg.ksm_zc_req_cookie != cookie) 
-                        continue;
-
-                tx->tx_msg.ksm_zc_req_cookie = 0;
-                list_del(&tx->tx_zc_list);
-
-                spin_unlock(&peer->ksnp_lock);
-
-                ksocknal_tx_decref(tx);
-                return 0;
-        }
-        spin_unlock(&peer->ksnp_lock);
-
-        return -EPROTO;
-}
-
-int
-ksocknal_process_receive (ksock_conn_t *conn)
-{
-        int           rc;
-        
-        LASSERT (atomic_read(&conn->ksnc_conn_refcount) > 0);
-
-        /* NB: sched lock NOT held */
-        /* SOCKNAL_RX_LNET_HEADER is here for backward compatability */
-        LASSERT (conn->ksnc_rx_state == SOCKNAL_RX_KSM_HEADER ||
-                 conn->ksnc_rx_state == SOCKNAL_RX_LNET_PAYLOAD ||
-                 conn->ksnc_rx_state == SOCKNAL_RX_LNET_HEADER ||
-                 conn->ksnc_rx_state == SOCKNAL_RX_SLOP);
- again:
-        if (conn->ksnc_rx_nob_wanted != 0) {
-                rc = ksocknal_receive(conn);
-
-                if (rc <= 0) {
-                        LASSERT (rc != -EAGAIN);
-
-                        if (rc == 0)
-                                CDEBUG (D_NET, "[%p] EOF from %s"
-                                        " ip %d.%d.%d.%d:%d\n", conn, 
-                                        libcfs_id2str(conn->ksnc_peer->ksnp_id),
-                                        HIPQUAD(conn->ksnc_ipaddr),
-                                        conn->ksnc_port);
-                        else if (!conn->ksnc_closing)
-                                CERROR ("[%p] Error %d on read from %s"
-                                        " ip %d.%d.%d.%d:%d\n",
-                                        conn, rc, 
-                                        libcfs_id2str(conn->ksnc_peer->ksnp_id),
-                                        HIPQUAD(conn->ksnc_ipaddr),
-                                        conn->ksnc_port);
-
-                        /* it's not an error if conn is being closed */
-                        ksocknal_close_conn_and_siblings (conn, 
-                                                          (conn->ksnc_closing) ? 0 : rc);
-                        return (rc == 0 ? -ESHUTDOWN : rc);
-                }
-                
-                if (conn->ksnc_rx_nob_wanted != 0) {
-                        /* short read */
-                        return (-EAGAIN);
-                }
+                if (conn->ksnc_rx_nob_wanted != 0) {
+                        /* short read */
+                        return (-EAGAIN);
+                }
         }
         switch (conn->ksnc_rx_state) {
         case SOCKNAL_RX_KSM_HEADER:
                 if (conn->ksnc_flip) {
                         __swab32s(&conn->ksnc_msg.ksm_type);
                         __swab32s(&conn->ksnc_msg.ksm_csum);
-                        __swab64s(&conn->ksnc_msg.ksm_zc_req_cookie);
-                        __swab64s(&conn->ksnc_msg.ksm_zc_ack_cookie);
-                } 
+                        __swab64s(&conn->ksnc_msg.ksm_zc_cookies[0]);
+                        __swab64s(&conn->ksnc_msg.ksm_zc_cookies[1]);
+                }
+
+                if (conn->ksnc_msg.ksm_type != KSOCK_MSG_NOOP &&
+                    conn->ksnc_msg.ksm_type != KSOCK_MSG_LNET) {
+                        CERROR("%s: Unknown message type: %x\n",
+                               libcfs_id2str(conn->ksnc_peer->ksnp_id),
+                               conn->ksnc_msg.ksm_type);
+                        ksocknal_new_packet(conn, 0);
+                        ksocknal_close_conn_and_siblings(conn, -EPROTO);
+                        return (-EPROTO);
+                }
 
                 if (conn->ksnc_msg.ksm_type == KSOCK_MSG_NOOP &&
                     conn->ksnc_msg.ksm_csum != 0 &&     /* has checksum */
-                    conn->ksnc_msg.ksm_csum != conn->ksnc_rx_csum) { 
+                    conn->ksnc_msg.ksm_csum != conn->ksnc_rx_csum) {
                         /* NOOP Checksum error */
                         CERROR("%s: Checksum error, wire:0x%08X data:0x%08X\n",
                                libcfs_id2str(conn->ksnc_peer->ksnp_id),
@@ -1330,55 +1253,55 @@ ksocknal_process_receive (ksock_conn_t *conn)
                         return (-EIO);
                 }
 
-                if (conn->ksnc_msg.ksm_zc_ack_cookie != 0) {
-                        LASSERT(conn->ksnc_proto == &ksocknal_protocol_v2x);
+                if (conn->ksnc_msg.ksm_zc_cookies[1] != 0) {
+                        __u64 cookie = 0;
+
+                        LASSERT (conn->ksnc_proto != &ksocknal_protocol_v1x);
+
+                        if (conn->ksnc_msg.ksm_type == KSOCK_MSG_NOOP)
+                                cookie = conn->ksnc_msg.ksm_zc_cookies[0];
+
+                        rc = conn->ksnc_proto->pro_handle_zcack(conn, cookie,
+                                               conn->ksnc_msg.ksm_zc_cookies[1]);
 
-                        rc = ksocknal_handle_zc_ack(conn->ksnc_peer,
-                                                    conn->ksnc_msg.ksm_zc_ack_cookie);
                         if (rc != 0) {
-                                CERROR("%s: Unknown zero copy ACK cookie: "LPU64"\n",
+                               CERROR("%s: Unknown ZC-ACK cookie: %llu, %llu\n",
                                        libcfs_id2str(conn->ksnc_peer->ksnp_id),
-                                       conn->ksnc_msg.ksm_zc_ack_cookie);
+                                       cookie, conn->ksnc_msg.ksm_zc_cookies[1]);
                                 ksocknal_new_packet(conn, 0);
                                 ksocknal_close_conn_and_siblings(conn, -EPROTO);
                                 return (rc);
                         }
                 }
 
-                if (conn->ksnc_msg.ksm_type == KSOCK_MSG_NOOP) { 
+                if (conn->ksnc_msg.ksm_type == KSOCK_MSG_NOOP) {
                         ksocknal_new_packet (conn, 0);
                         return 0;       /* NOOP is done and just return */
                 }
-                LASSERT (conn->ksnc_msg.ksm_type == KSOCK_MSG_LNET);
 
-                if (conn->ksnc_type == SOCKLND_CONN_BULK_IN) {
-                        conn->ksnc_rx_state = SOCKNAL_RX_LNET_HEADER;
-                        /* has read lnet_hdr_t already (re ksocknal_new_packet), fall through */
-                } else {
-                        conn->ksnc_rx_state = SOCKNAL_RX_LNET_HEADER;
-                        conn->ksnc_rx_nob_wanted = sizeof(ksock_lnet_msg_t);
-                        conn->ksnc_rx_nob_left = sizeof(ksock_lnet_msg_t);
-        
-                        conn->ksnc_rx_iov = (struct iovec *)&conn->ksnc_rx_iov_space;
-                        conn->ksnc_rx_iov[0].iov_base = (char *)&conn->ksnc_msg.ksm_u.lnetmsg;
-                        conn->ksnc_rx_iov[0].iov_len  = sizeof(ksock_lnet_msg_t);
-
-                        conn->ksnc_rx_niov = 1;
-                        conn->ksnc_rx_kiov = NULL;
-                        conn->ksnc_rx_nkiov = 0;
-
-                        goto again;     /* read lnet header now */
-                }
+                conn->ksnc_rx_state = SOCKNAL_RX_LNET_HEADER;
+               conn->ksnc_rx_nob_wanted = sizeof(struct ksock_lnet_msg);
+               conn->ksnc_rx_nob_left = sizeof(struct ksock_lnet_msg);
+
+               conn->ksnc_rx_iov = (struct kvec *)&conn->ksnc_rx_iov_space;
+                conn->ksnc_rx_iov[0].iov_base = (char *)&conn->ksnc_msg.ksm_u.lnetmsg;
+               conn->ksnc_rx_iov[0].iov_len  = sizeof(struct ksock_lnet_msg);
+
+                conn->ksnc_rx_niov = 1;
+                conn->ksnc_rx_kiov = NULL;
+                conn->ksnc_rx_nkiov = 0;
+
+                goto again;     /* read lnet header now */
 
         case SOCKNAL_RX_LNET_HEADER:
                 /* unpack message header */
                 conn->ksnc_proto->pro_unpack(&conn->ksnc_msg);
 
-                if ((conn->ksnc_peer->ksnp_id.pid & LNET_PID_USERFLAG) != 0) { 
-                        /* Userspace peer */
-                        lnet_process_id_t *id = &conn->ksnc_peer->ksnp_id;
-                        lnet_hdr_t        *lhdr = &conn->ksnc_msg.ksm_u.lnetmsg.ksnm_hdr;
-                        
+                if ((conn->ksnc_peer->ksnp_id.pid & LNET_PID_USERFLAG) != 0) {
+                        /* Userspace peer_ni */
+                        lhdr = &conn->ksnc_msg.ksm_u.lnetmsg.ksnm_hdr;
+                        id   = &conn->ksnc_peer->ksnp_id;
+
                         /* Substitute process ID assigned at connection time */
                         lhdr->src_pid = cpu_to_le32(id->pid);
                         lhdr->src_nid = cpu_to_le64(id->nid);
@@ -1386,9 +1309,9 @@ ksocknal_process_receive (ksock_conn_t *conn)
 
                 conn->ksnc_rx_state = SOCKNAL_RX_PARSE;
                 ksocknal_conn_addref(conn);     /* ++ref while parsing */
-                
-                rc = lnet_parse(conn->ksnc_peer->ksnp_ni, 
-                                &conn->ksnc_msg.ksm_u.lnetmsg.ksnm_hdr, 
+
+                rc = lnet_parse(conn->ksnc_peer->ksnp_ni,
+                                &conn->ksnc_msg.ksm_u.lnetmsg.ksnm_hdr,
                                 conn->ksnc_peer->ksnp_id.nid, conn, 0);
                 if (rc < 0) {
                         /* I just received garbage: give up on this conn */
@@ -1401,10 +1324,10 @@ ksocknal_process_receive (ksock_conn_t *conn)
                 /* I'm racing with ksocknal_recv() */
                 LASSERT (conn->ksnc_rx_state == SOCKNAL_RX_PARSE ||
                          conn->ksnc_rx_state == SOCKNAL_RX_LNET_PAYLOAD);
-                
+
                 if (conn->ksnc_rx_state != SOCKNAL_RX_LNET_PAYLOAD)
                         return 0;
-                
+
                 /* ksocknal_recv() got called */
                 goto again;
 
@@ -1414,21 +1337,30 @@ ksocknal_process_receive (ksock_conn_t *conn)
 
                 if (conn->ksnc_rx_nob_left == 0 &&   /* not truncating */
                     conn->ksnc_msg.ksm_csum != 0 &&  /* has checksum */
-                    conn->ksnc_msg.ksm_csum != conn->ksnc_rx_csum) { 
+                    conn->ksnc_msg.ksm_csum != conn->ksnc_rx_csum) {
                         CERROR("%s: Checksum error, wire:0x%08X data:0x%08X\n",
                                libcfs_id2str(conn->ksnc_peer->ksnp_id),
                                conn->ksnc_msg.ksm_csum, conn->ksnc_rx_csum);
                         rc = -EIO;
                 }
 
-                lnet_finalize(conn->ksnc_peer->ksnp_ni, conn->ksnc_cookie, rc);
+                if (rc == 0 && conn->ksnc_msg.ksm_zc_cookies[0] != 0) {
+                        LASSERT(conn->ksnc_proto != &ksocknal_protocol_v1x);
 
-                if (rc == 0 && conn->ksnc_msg.ksm_zc_req_cookie != 0) {
-                        LASSERT(conn->ksnc_proto == &ksocknal_protocol_v2x);
-                        rc = ksocknal_handle_zc_req(conn->ksnc_peer,
-                                                    conn->ksnc_msg.ksm_zc_req_cookie);
+                        lhdr = &conn->ksnc_msg.ksm_u.lnetmsg.ksnm_hdr;
+                        id   = &conn->ksnc_peer->ksnp_id;
+
+                        rc = conn->ksnc_proto->pro_handle_zcreq(conn,
+                                        conn->ksnc_msg.ksm_zc_cookies[0],
+                                        *ksocknal_tunables.ksnd_nonblk_zcack ||
+                                        le64_to_cpu(lhdr->src_nid) != id->nid);
                 }
 
+               if (rc && conn->ksnc_lnet_msg)
+                       conn->ksnc_lnet_msg->msg_health_status =
+                               LNET_MSG_STATUS_REMOTE_ERROR;
+               lnet_finalize(conn->ksnc_lnet_msg, rc);
+
                 if (rc != 0) {
                         ksocknal_new_packet(conn, 0);
                         ksocknal_close_conn_and_siblings (conn, rc);
@@ -1452,19 +1384,20 @@ ksocknal_process_receive (ksock_conn_t *conn)
 }
 
 int
-ksocknal_recv (lnet_ni_t *ni, void *private, lnet_msg_t *msg, int delayed,
-               unsigned int niov, struct iovec *iov, lnet_kiov_t *kiov,
-               unsigned int offset, unsigned int mlen, unsigned int rlen)
+ksocknal_recv(struct lnet_ni *ni, void *private, struct lnet_msg *msg,
+             int delayed, unsigned int niov, struct kvec *iov,
+             lnet_kiov_t *kiov, unsigned int offset, unsigned int mlen,
+             unsigned int rlen)
 {
-        ksock_conn_t  *conn = (ksock_conn_t *)private;
-        ksock_sched_t *sched = conn->ksnc_scheduler;
+       struct ksock_conn *conn = private;
+       struct ksock_sched *sched = conn->ksnc_scheduler;
 
         LASSERT (mlen <= rlen);
         LASSERT (niov <= LNET_MAX_IOV);
-        
-        conn->ksnc_cookie = msg;
-        conn->ksnc_rx_nob_wanted = mlen;
-        conn->ksnc_rx_nob_left   = rlen;
+
+       conn->ksnc_lnet_msg = msg;
+       conn->ksnc_rx_nob_wanted = mlen;
+       conn->ksnc_rx_nob_left   = rlen;
 
         if (mlen == 0 || iov != NULL) {
                 conn->ksnc_rx_nkiov = 0;
@@ -1477,659 +1410,365 @@ ksocknal_recv (lnet_ni_t *ni, void *private, lnet_msg_t *msg, int delayed,
                 conn->ksnc_rx_niov = 0;
                 conn->ksnc_rx_iov  = NULL;
                 conn->ksnc_rx_kiov = conn->ksnc_rx_iov_space.kiov;
-                conn->ksnc_rx_nkiov = 
+                conn->ksnc_rx_nkiov =
                         lnet_extract_kiov(LNET_MAX_IOV, conn->ksnc_rx_kiov,
                                           niov, kiov, offset, mlen);
         }
-        
-        LASSERT (mlen == 
+
+        LASSERT (mlen ==
                  lnet_iov_nob (conn->ksnc_rx_niov, conn->ksnc_rx_iov) +
                  lnet_kiov_nob (conn->ksnc_rx_nkiov, conn->ksnc_rx_kiov));
 
         LASSERT (conn->ksnc_rx_scheduled);
 
-        spin_lock_bh (&sched->kss_lock);
+       spin_lock_bh(&sched->kss_lock);
+
+       switch (conn->ksnc_rx_state) {
+       case SOCKNAL_RX_PARSE_WAIT:
+               list_add_tail(&conn->ksnc_rx_list, &sched->kss_rx_conns);
+               wake_up(&sched->kss_waitq);
+               LASSERT(conn->ksnc_rx_ready);
+               break;
 
-        switch (conn->ksnc_rx_state) {
-        case SOCKNAL_RX_PARSE_WAIT:
-                list_add_tail(&conn->ksnc_rx_list, &sched->kss_rx_conns);
-                cfs_waitq_signal (&sched->kss_waitq);
-                LASSERT (conn->ksnc_rx_ready);
-                break;
-                
         case SOCKNAL_RX_PARSE:
                 /* scheduler hasn't noticed I'm parsing yet */
                 break;
         }
 
         conn->ksnc_rx_state = SOCKNAL_RX_LNET_PAYLOAD;
-        
-        spin_unlock_bh (&sched->kss_lock);
-        ksocknal_conn_decref(conn);
-        return (0);
+
+       spin_unlock_bh(&sched->kss_lock);
+       ksocknal_conn_decref(conn);
+       return 0;
 }
 
 static inline int
-ksocknal_sched_cansleep(ksock_sched_t *sched)
+ksocknal_sched_cansleep(struct ksock_sched *sched)
 {
-        int           rc;
+       int           rc;
+
+       spin_lock_bh(&sched->kss_lock);
 
-        spin_lock_bh (&sched->kss_lock);
+       rc = (!ksocknal_data.ksnd_shuttingdown &&
+             list_empty(&sched->kss_rx_conns) &&
+             list_empty(&sched->kss_tx_conns));
 
-        rc = (!ksocknal_data.ksnd_shuttingdown &&
-              list_empty(&sched->kss_rx_conns) &&
-              list_empty(&sched->kss_tx_conns));
-        
-        spin_unlock_bh (&sched->kss_lock);
-        return (rc);
+       spin_unlock_bh(&sched->kss_lock);
+       return rc;
 }
 
-int ksocknal_scheduler (void *arg)
+int ksocknal_scheduler(void *arg)
 {
-        ksock_sched_t     *sched = (ksock_sched_t *)arg;
-        ksock_conn_t      *conn;
-        ksock_tx_t        *tx;
-        int                rc;
-        int                nloops = 0;
-        int                id = sched - ksocknal_data.ksnd_schedulers;
-        char               name[16];
-
-        snprintf (name, sizeof (name),"socknal_sd%02d", id);
-        cfs_daemonize (name);
-        cfs_block_allsigs ();
-
-#if defined(CONFIG_SMP) && defined(CPU_AFFINITY)
-        id = ksocknal_sched2cpu(id);
-        if (cpu_online(id)) {
-                cpumask_t m;
-                cpu_set(id, m);
-                set_cpus_allowed(current, m);
-        } else {
-                CERROR ("Can't set CPU affinity for %s to %d\n", name, id);
-        }
-#endif /* CONFIG_SMP && CPU_AFFINITY */
-
-        spin_lock_bh (&sched->kss_lock);
-
-        while (!ksocknal_data.ksnd_shuttingdown) {
-                int did_something = 0;
-
-                /* Ensure I progress everything semi-fairly */
-
-                if (!list_empty (&sched->kss_rx_conns)) {
-                        conn = list_entry(sched->kss_rx_conns.next,
-                                          ksock_conn_t, ksnc_rx_list);
-                        list_del(&conn->ksnc_rx_list);
-
-                        LASSERT(conn->ksnc_rx_scheduled);
-                        LASSERT(conn->ksnc_rx_ready);
-
-                        /* clear rx_ready in case receive isn't complete.
-                         * Do it BEFORE we call process_recv, since
-                         * data_ready can set it any time after we release
-                         * kss_lock. */
-                        conn->ksnc_rx_ready = 0;
-                        spin_unlock_bh (&sched->kss_lock);
-
-                        rc = ksocknal_process_receive(conn);
-
-                        spin_lock_bh (&sched->kss_lock);
-
-                        /* I'm the only one that can clear this flag */
-                        LASSERT(conn->ksnc_rx_scheduled);
-
-                        /* Did process_receive get everything it wanted? */
-                        if (rc == 0)
-                                conn->ksnc_rx_ready = 1;
-
-                        if (conn->ksnc_rx_state == SOCKNAL_RX_PARSE) {
-                                /* Conn blocked waiting for ksocknal_recv()
-                                 * I change its state (under lock) to signal
-                                 * it can be rescheduled */
-                                conn->ksnc_rx_state = SOCKNAL_RX_PARSE_WAIT;
-                        } else if (conn->ksnc_rx_ready) {
-                                /* reschedule for rx */
-                                list_add_tail (&conn->ksnc_rx_list,
-                                               &sched->kss_rx_conns);
-                        } else {
-                                conn->ksnc_rx_scheduled = 0;
-                                /* drop my ref */
-                                ksocknal_conn_decref(conn);
-                        }
-
-                        did_something = 1;
-                }
-
-                if (!list_empty (&sched->kss_tx_conns)) {
-                        CFS_LIST_HEAD    (zlist);
-
-                        if (!list_empty(&sched->kss_zombie_noop_txs)) {
-                                list_add(&zlist, &sched->kss_zombie_noop_txs); 
-                                list_del_init(&sched->kss_zombie_noop_txs);
-                        }
-
-                        conn = list_entry(sched->kss_tx_conns.next,
-                                          ksock_conn_t, ksnc_tx_list);
-                        list_del (&conn->ksnc_tx_list);
-                        
-                        LASSERT(conn->ksnc_tx_scheduled);
-                        LASSERT(conn->ksnc_tx_ready);
-                        LASSERT(!list_empty(&conn->ksnc_tx_queue));
-                        
-                        tx = list_entry(conn->ksnc_tx_queue.next,
-                                        ksock_tx_t, tx_list);
-
-                        if (conn->ksnc_tx_mono == tx)
-                                ksocknal_next_mono_tx(conn);
-
-                        /* dequeue now so empty list => more to send */
-                        list_del(&tx->tx_list);
-
-                        /* Clear tx_ready in case send isn't complete.  Do
-                         * it BEFORE we call process_transmit, since
-                         * write_space can set it any time after we release
-                         * kss_lock. */
-                        conn->ksnc_tx_ready = 0;
-                        spin_unlock_bh (&sched->kss_lock);
-
-                        if (!list_empty(&zlist)) {
-                                /* free zombie noop txs, it's fast because 
-                                 * noop txs are just put in freelist */
-                                ksocknal_txlist_done(NULL, &zlist, 0);
-                        }
-
-                        rc = ksocknal_process_transmit(conn, tx);
-
-                        if (rc == -ENOMEM || rc == -EAGAIN) {
-                                /* Incomplete send: replace tx on HEAD of tx_queue */
-                                spin_lock_bh (&sched->kss_lock);
-                                list_add (&tx->tx_list, &conn->ksnc_tx_queue);
-                        } else {
-                                /* Complete send; tx -ref */
-                                ksocknal_tx_decref (tx);
-
-                                spin_lock_bh (&sched->kss_lock);
-                                /* assume space for more */
-                                conn->ksnc_tx_ready = 1;
-                        }
-
-                        if (rc == -ENOMEM) {
-                                /* Do nothing; after a short timeout, this
-                                 * conn will be reposted on kss_tx_conns. */
-                        } else if (conn->ksnc_tx_ready &&
-                                   !list_empty (&conn->ksnc_tx_queue)) {
-                                /* reschedule for tx */
-                                list_add_tail (&conn->ksnc_tx_list, 
-                                               &sched->kss_tx_conns);
-                        } else {
-                                conn->ksnc_tx_scheduled = 0;
-                                /* drop my ref */
-                                ksocknal_conn_decref(conn);
-                        }
-                                
-                        did_something = 1;
-                }
-                if (!did_something ||           /* nothing to do */
-                    ++nloops == SOCKNAL_RESCHED) { /* hogging CPU? */
-                        spin_unlock_bh (&sched->kss_lock);
-
-                        nloops = 0;
-
-                        if (!did_something) {   /* wait for something to do */
-                                rc = wait_event_interruptible_exclusive(
-                                        sched->kss_waitq,
-                                        !ksocknal_sched_cansleep(sched));
-                                LASSERT (rc == 0);
-                        } else {
-                                our_cond_resched();
-                        }
-
-                        spin_lock_bh (&sched->kss_lock);
-                }
-        }
-
-        spin_unlock_bh (&sched->kss_lock);
-        ksocknal_thread_fini ();
-        return (0);
+       struct ksock_sched *sched;
+       struct ksock_conn *conn;
+       struct ksock_tx *tx;
+       int rc;
+       int nloops = 0;
+       long id = (long)arg;
+       struct page **rx_scratch_pgs;
+       struct kvec *scratch_iov;
+
+       sched = ksocknal_data.ksnd_schedulers[KSOCK_THREAD_CPT(id)];
+
+       LIBCFS_CPT_ALLOC(rx_scratch_pgs, lnet_cpt_table(), sched->kss_cpt,
+                        sizeof(*rx_scratch_pgs) * LNET_MAX_IOV);
+       if (!rx_scratch_pgs) {
+               CERROR("Unable to allocate scratch pages\n");
+               return -ENOMEM;
+       }
+
+       LIBCFS_CPT_ALLOC(scratch_iov, lnet_cpt_table(), sched->kss_cpt,
+                        sizeof(*scratch_iov) * LNET_MAX_IOV);
+       if (!scratch_iov) {
+               CERROR("Unable to allocate scratch iov\n");
+               return -ENOMEM;
+       }
+
+       cfs_block_allsigs();
+
+       rc = cfs_cpt_bind(lnet_cpt_table(), sched->kss_cpt);
+       if (rc != 0) {
+               CWARN("Can't set CPU partition affinity to %d: %d\n",
+                       sched->kss_cpt, rc);
+       }
+
+       spin_lock_bh(&sched->kss_lock);
+
+       while (!ksocknal_data.ksnd_shuttingdown) {
+               int did_something = 0;
+
+               /* Ensure I progress everything semi-fairly */
+
+               if (!list_empty(&sched->kss_rx_conns)) {
+                       conn = list_entry(sched->kss_rx_conns.next,
+                                         struct ksock_conn, ksnc_rx_list);
+                       list_del(&conn->ksnc_rx_list);
+
+                       LASSERT(conn->ksnc_rx_scheduled);
+                       LASSERT(conn->ksnc_rx_ready);
+
+                       /* clear rx_ready in case receive isn't complete.
+                        * Do it BEFORE we call process_recv, since
+                        * data_ready can set it any time after we release
+                        * kss_lock. */
+                       conn->ksnc_rx_ready = 0;
+                       spin_unlock_bh(&sched->kss_lock);
+
+                       rc = ksocknal_process_receive(conn, rx_scratch_pgs,
+                                                     scratch_iov);
+
+                       spin_lock_bh(&sched->kss_lock);
+
+                       /* I'm the only one that can clear this flag */
+                       LASSERT(conn->ksnc_rx_scheduled);
+
+                       /* Did process_receive get everything it wanted? */
+                       if (rc == 0)
+                               conn->ksnc_rx_ready = 1;
+
+                       if (conn->ksnc_rx_state == SOCKNAL_RX_PARSE) {
+                               /* Conn blocked waiting for ksocknal_recv()
+                                * I change its state (under lock) to signal
+                                * it can be rescheduled */
+                               conn->ksnc_rx_state = SOCKNAL_RX_PARSE_WAIT;
+                       } else if (conn->ksnc_rx_ready) {
+                               /* reschedule for rx */
+                               list_add_tail(&conn->ksnc_rx_list,
+                                                  &sched->kss_rx_conns);
+                       } else {
+                               conn->ksnc_rx_scheduled = 0;
+                               /* drop my ref */
+                               ksocknal_conn_decref(conn);
+                       }
+
+                       did_something = 1;
+               }
+
+               if (!list_empty(&sched->kss_tx_conns)) {
+                       LIST_HEAD(zlist);
+
+                       if (!list_empty(&sched->kss_zombie_noop_txs)) {
+                               list_add(&zlist,
+                                        &sched->kss_zombie_noop_txs);
+                               list_del_init(&sched->kss_zombie_noop_txs);
+                       }
+
+                       conn = list_entry(sched->kss_tx_conns.next,
+                                         struct ksock_conn, ksnc_tx_list);
+                       list_del(&conn->ksnc_tx_list);
+
+                       LASSERT(conn->ksnc_tx_scheduled);
+                       LASSERT(conn->ksnc_tx_ready);
+                       LASSERT(!list_empty(&conn->ksnc_tx_queue));
+
+                       tx = list_entry(conn->ksnc_tx_queue.next,
+                                       struct ksock_tx, tx_list);
+
+                       if (conn->ksnc_tx_carrier == tx)
+                               ksocknal_next_tx_carrier(conn);
+
+                       /* dequeue now so empty list => more to send */
+                       list_del(&tx->tx_list);
+
+                       /* Clear tx_ready in case send isn't complete.  Do
+                        * it BEFORE we call process_transmit, since
+                        * write_space can set it any time after we release
+                        * kss_lock. */
+                       conn->ksnc_tx_ready = 0;
+                       spin_unlock_bh(&sched->kss_lock);
+
+                       if (!list_empty(&zlist)) {
+                               /* free zombie noop txs, it's fast because
+                                * noop txs are just put in freelist */
+                               ksocknal_txlist_done(NULL, &zlist, 0);
+                       }
+
+                       rc = ksocknal_process_transmit(conn, tx, scratch_iov);
+
+                       if (rc == -ENOMEM || rc == -EAGAIN) {
+                               /* Incomplete send: replace tx on HEAD of tx_queue */
+                               spin_lock_bh(&sched->kss_lock);
+                               list_add(&tx->tx_list,
+                                        &conn->ksnc_tx_queue);
+                       } else {
+                               /* Complete send; tx -ref */
+                               ksocknal_tx_decref(tx);
+
+                               spin_lock_bh(&sched->kss_lock);
+                               /* assume space for more */
+                               conn->ksnc_tx_ready = 1;
+                       }
+
+                       if (rc == -ENOMEM) {
+                               /* Do nothing; after a short timeout, this
+                                * conn will be reposted on kss_tx_conns. */
+                       } else if (conn->ksnc_tx_ready &&
+                                  !list_empty(&conn->ksnc_tx_queue)) {
+                               /* reschedule for tx */
+                               list_add_tail(&conn->ksnc_tx_list,
+                                             &sched->kss_tx_conns);
+                       } else {
+                               conn->ksnc_tx_scheduled = 0;
+                               /* drop my ref */
+                               ksocknal_conn_decref(conn);
+                       }
+
+                       did_something = 1;
+               }
+               if (!did_something ||           /* nothing to do */
+                   ++nloops == SOCKNAL_RESCHED) { /* hogging CPU? */
+                       spin_unlock_bh(&sched->kss_lock);
+
+                       nloops = 0;
+
+                       if (!did_something) {   /* wait for something to do */
+                               rc = wait_event_interruptible_exclusive(
+                                       sched->kss_waitq,
+                                       !ksocknal_sched_cansleep(sched));
+                               LASSERT (rc == 0);
+                       } else {
+                               cond_resched();
+                       }
+
+                       spin_lock_bh(&sched->kss_lock);
+               }
+       }
+
+       spin_unlock_bh(&sched->kss_lock);
+       LIBCFS_FREE(rx_scratch_pgs, sizeof(*rx_scratch_pgs) *
+                   LNET_MAX_IOV);
+       LIBCFS_FREE(scratch_iov, sizeof(*scratch_iov) *
+                   LNET_MAX_IOV);
+       ksocknal_thread_fini();
+       return 0;
 }
 
 /*
  * Add connection to kss_rx_conns of scheduler
  * and wakeup the scheduler.
  */
-void ksocknal_read_callback (ksock_conn_t *conn)
+void ksocknal_read_callback(struct ksock_conn *conn)
 {
-        ksock_sched_t *sched; 
-        ENTRY;
+       struct ksock_sched *sched;
+       ENTRY;
 
-        sched = conn->ksnc_scheduler; 
+       sched = conn->ksnc_scheduler;
 
-        spin_lock_bh (&sched->kss_lock);
+       spin_lock_bh(&sched->kss_lock);
 
-        conn->ksnc_rx_ready = 1; 
+       conn->ksnc_rx_ready = 1;
 
-        if (!conn->ksnc_rx_scheduled) {  /* not being progressed */ 
-                list_add_tail(&conn->ksnc_rx_list, 
-                              &sched->kss_rx_conns); 
-                conn->ksnc_rx_scheduled = 1; 
-                /* extra ref for scheduler */ 
-                ksocknal_conn_addref(conn);
+       if (!conn->ksnc_rx_scheduled) {  /* not being progressed */
+               list_add_tail(&conn->ksnc_rx_list,
+                                 &sched->kss_rx_conns);
+               conn->ksnc_rx_scheduled = 1;
+               /* extra ref for scheduler */
+               ksocknal_conn_addref(conn);
 
-                cfs_waitq_signal (&sched->kss_waitq); 
-        } 
-        spin_unlock_bh (&sched->kss_lock);
+               wake_up (&sched->kss_waitq);
+       }
+       spin_unlock_bh(&sched->kss_lock);
 
-        EXIT;
-} 
+       EXIT;
+}
 
 /*
  * Add connection to kss_tx_conns of scheduler
  * and wakeup the scheduler.
  */
-void ksocknal_write_callback (ksock_conn_t *conn)
-{ 
-        ksock_sched_t *sched; 
-        ENTRY;
-        
-        sched = conn->ksnc_scheduler; 
-
-        spin_lock_bh (&sched->kss_lock);
-
-        conn->ksnc_tx_ready = 1; 
-
-        if (!conn->ksnc_tx_scheduled && // not being progressed 
-            !list_empty(&conn->ksnc_tx_queue)){//packets to send 
-                list_add_tail (&conn->ksnc_tx_list, 
-                               &sched->kss_tx_conns); 
-                conn->ksnc_tx_scheduled = 1; 
-                /* extra ref for scheduler */ 
-                ksocknal_conn_addref(conn); 
-
-                cfs_waitq_signal (&sched->kss_waitq); 
-        } 
-
-        spin_unlock_bh (&sched->kss_lock);
-
-        EXIT;
-}
-
-ksock_protocol_t *
-ksocknal_compat_protocol (ksock_hello_msg_t *hello)
-{
-        if ((hello->kshm_magic   == LNET_PROTO_MAGIC &&
-             hello->kshm_version == KSOCK_PROTO_V2) ||
-            (hello->kshm_magic   == __swab32(LNET_PROTO_MAGIC) &&
-             hello->kshm_version == __swab32(KSOCK_PROTO_V2)))
-                return &ksocknal_protocol_v2x;
-
-        if (hello->kshm_magic == le32_to_cpu(LNET_PROTO_TCP_MAGIC)) {
-                lnet_magicversion_t *hmv = (lnet_magicversion_t *)hello;
-
-                CLASSERT (sizeof (lnet_magicversion_t) ==
-                          offsetof (ksock_hello_msg_t, kshm_src_nid));
-
-                if (hmv->version_major == cpu_to_le16 (KSOCK_PROTO_V1_MAJOR) &&
-                    hmv->version_minor == cpu_to_le16 (KSOCK_PROTO_V1_MINOR))
-                        return &ksocknal_protocol_v1x;
-        }
-
-        return NULL;
-}
-
-static int
-ksocknal_send_hello_v1 (ksock_conn_t *conn, ksock_hello_msg_t *hello)
-{
-        cfs_socket_t        *sock = conn->ksnc_sock;
-        lnet_hdr_t          *hdr;
-        lnet_magicversion_t *hmv;
-        int                  rc;
-        int                  i;
-
-        CLASSERT(sizeof(lnet_magicversion_t) == offsetof(lnet_hdr_t, src_nid));
-
-        LIBCFS_ALLOC(hdr, sizeof(*hdr));
-        if (hdr == NULL) {
-                CERROR("Can't allocate lnet_hdr_t\n");
-                return -ENOMEM;
-        }
-
-        hmv = (lnet_magicversion_t *)&hdr->dest_nid;
-
-        /* Re-organize V2.x message header to V1.x (lnet_hdr_t)
-         * header and send out */
-        hmv->magic         = cpu_to_le32 (LNET_PROTO_TCP_MAGIC);
-        hmv->version_major = cpu_to_le16 (KSOCK_PROTO_V1_MAJOR);
-        hmv->version_minor = cpu_to_le16 (KSOCK_PROTO_V1_MINOR);
-
-        if (the_lnet.ln_testprotocompat != 0) {
-                /* single-shot proto check */
-                LNET_LOCK();
-                if ((the_lnet.ln_testprotocompat & 1) != 0) {
-                        hmv->version_major++;   /* just different! */
-                        the_lnet.ln_testprotocompat &= ~1;
-                }
-                if ((the_lnet.ln_testprotocompat & 2) != 0) {
-                        hmv->magic = LNET_PROTO_MAGIC;
-                        the_lnet.ln_testprotocompat &= ~2;
-                }
-                LNET_UNLOCK();
-        }
-
-        hdr->src_nid        = cpu_to_le64 (hello->kshm_src_nid);
-        hdr->src_pid        = cpu_to_le32 (hello->kshm_src_pid);
-        hdr->type           = cpu_to_le32 (LNET_MSG_HELLO);
-        hdr->payload_length = cpu_to_le32 (hello->kshm_nips * sizeof(__u32));
-        hdr->msg.hello.type = cpu_to_le32 (hello->kshm_ctype);
-        hdr->msg.hello.incarnation = cpu_to_le64 (hello->kshm_src_incarnation);
-
-        rc = libcfs_sock_write(sock, hdr, sizeof(*hdr), lnet_acceptor_timeout());
-
-        if (rc != 0) {
-                CDEBUG (D_NETERROR, "Error %d sending HELLO hdr to %u.%u.%u.%u/%d\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr), conn->ksnc_port);
-                goto out;
-        }
-
-        if (hello->kshm_nips == 0)
-                goto out;
-
-        for (i = 0; i < hello->kshm_nips; i++) {
-                hello->kshm_ips[i] = __cpu_to_le32 (hello->kshm_ips[i]);
-        }
-        
-        rc = libcfs_sock_write(sock, hello->kshm_ips,
-                               hello->kshm_nips * sizeof(__u32),
-                               lnet_acceptor_timeout());
-        if (rc != 0) {
-                CDEBUG (D_NETERROR, "Error %d sending HELLO payload (%d)"
-                        " to %u.%u.%u.%u/%d\n", rc, hello->kshm_nips, 
-                        HIPQUAD(conn->ksnc_ipaddr), conn->ksnc_port);
-        }
-out:
-        LIBCFS_FREE(hdr, sizeof(*hdr));
-
-        return rc;
-} 
-
-static int
-ksocknal_send_hello_v2 (ksock_conn_t *conn, ksock_hello_msg_t *hello)
+void ksocknal_write_callback(struct ksock_conn *conn)
 {
-        cfs_socket_t   *sock = conn->ksnc_sock;
-        int             rc;
-
-        hello->kshm_magic       = LNET_PROTO_MAGIC;
-        hello->kshm_version     = KSOCK_PROTO_V2;
-
-        if (the_lnet.ln_testprotocompat != 0) {
-                /* single-shot proto check */
-                LNET_LOCK();
-                if ((the_lnet.ln_testprotocompat & 1) != 0) {
-                        hello->kshm_version++;   /* just different! */
-                        the_lnet.ln_testprotocompat &= ~1;
-                }
-                LNET_UNLOCK();
-        }
-
-        rc = libcfs_sock_write(sock, hello, offsetof(ksock_hello_msg_t, kshm_ips),
-                               lnet_acceptor_timeout());
-
-        if (rc != 0) {
-                CDEBUG (D_NETERROR, "Error %d sending HELLO hdr to %u.%u.%u.%u/%d\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr), conn->ksnc_port);
-                return rc;
-        }
-
-        if (hello->kshm_nips == 0)
-                return 0;
+       struct ksock_sched *sched;
+       ENTRY;
 
-        rc = libcfs_sock_write(sock, hello->kshm_ips,
-                               hello->kshm_nips * sizeof(__u32),
-                               lnet_acceptor_timeout());
-        if (rc != 0) {
-                CDEBUG (D_NETERROR, "Error %d sending HELLO payload (%d)"
-                        " to %u.%u.%u.%u/%d\n", rc, hello->kshm_nips,
-                        HIPQUAD(conn->ksnc_ipaddr), conn->ksnc_port);
-        }
-
-        return rc;
-}
-
-static int
-ksocknal_recv_hello_v1(ksock_conn_t *conn, ksock_hello_msg_t *hello,int timeout)
-{
-        cfs_socket_t        *sock = conn->ksnc_sock;
-        lnet_hdr_t          *hdr;
-        int                  rc;
-        int                  i;
-
-        LIBCFS_ALLOC(hdr, sizeof(*hdr));
-        if (hdr == NULL) {
-                CERROR("Can't allocate lnet_hdr_t\n");
-                return -ENOMEM;
-        }
-
-        rc = libcfs_sock_read(sock, &hdr->src_nid,
-                              sizeof (*hdr) - offsetof (lnet_hdr_t, src_nid),
-                              timeout);
-        if (rc != 0) {
-                CERROR ("Error %d reading rest of HELLO hdr from %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
-                LASSERT (rc < 0 && rc != -EALREADY);
-                goto out;
-        }
+       sched = conn->ksnc_scheduler;
 
-        /* ...and check we got what we expected */
-        if (hdr->type != cpu_to_le32 (LNET_MSG_HELLO)) {
-                CERROR ("Expecting a HELLO hdr,"
-                        " but got type %d from %u.%u.%u.%u\n",
-                        le32_to_cpu (hdr->type),
-                        HIPQUAD(conn->ksnc_ipaddr));
-                rc = -EPROTO;
-                goto out;
-        }
+       spin_lock_bh(&sched->kss_lock);
 
-        hello->kshm_src_nid         = le64_to_cpu (hdr->src_nid);
-        hello->kshm_src_pid         = le32_to_cpu (hdr->src_pid);
-        hello->kshm_src_incarnation = le64_to_cpu (hdr->msg.hello.incarnation);
-        hello->kshm_ctype           = le32_to_cpu (hdr->msg.hello.type);
-        hello->kshm_nips            = le32_to_cpu (hdr->payload_length) /
-                                         sizeof (__u32);
-
-        if (hello->kshm_nips > LNET_MAX_INTERFACES) {
-                CERROR("Bad nips %d from ip %u.%u.%u.%u\n",
-                       hello->kshm_nips, HIPQUAD(conn->ksnc_ipaddr));
-                rc = -EPROTO;
-                goto out;
-        }
+       conn->ksnc_tx_ready = 1;
 
-        if (hello->kshm_nips == 0)
-                goto out;
+       if (!conn->ksnc_tx_scheduled && /* not being progressed */
+           !list_empty(&conn->ksnc_tx_queue)) { /* packets to send */
+               list_add_tail(&conn->ksnc_tx_list, &sched->kss_tx_conns);
+               conn->ksnc_tx_scheduled = 1;
+               /* extra ref for scheduler */
+               ksocknal_conn_addref(conn);
 
-        rc = libcfs_sock_read(sock, hello->kshm_ips,
-                              hello->kshm_nips * sizeof(__u32), timeout);
-        if (rc != 0) {
-                CERROR ("Error %d reading IPs from ip %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
-                LASSERT (rc < 0 && rc != -EALREADY);
-                goto out;
-        }
+               wake_up(&sched->kss_waitq);
+       }
 
-        for (i = 0; i < hello->kshm_nips; i++) {
-                hello->kshm_ips[i] = __le32_to_cpu(hello->kshm_ips[i]);
-                
-                if (hello->kshm_ips[i] == 0) {
-                        CERROR("Zero IP[%d] from ip %u.%u.%u.%u\n",
-                               i, HIPQUAD(conn->ksnc_ipaddr));
-                        rc = -EPROTO;
-                        break;
-                }
-        }
-out:
-        LIBCFS_FREE(hdr, sizeof(*hdr));
+       spin_unlock_bh(&sched->kss_lock);
 
-        return rc;
+       EXIT;
 }
 
-static int
-ksocknal_recv_hello_v2 (ksock_conn_t *conn, ksock_hello_msg_t *hello, int timeout) 
+static struct ksock_proto *
+ksocknal_parse_proto_version (struct ksock_hello_msg *hello)
 {
-        cfs_socket_t      *sock = conn->ksnc_sock;
-        int                rc;         
-        int                i;
+        __u32   version = 0;
 
         if (hello->kshm_magic == LNET_PROTO_MAGIC)
-                conn->ksnc_flip = 0;
-        else
-                conn->ksnc_flip = 1;
-
-        rc = libcfs_sock_read(sock, &hello->kshm_src_nid,
-                              offsetof(ksock_hello_msg_t, kshm_ips) -
-                                       offsetof(ksock_hello_msg_t, kshm_src_nid),
-                              timeout); 
-        if (rc != 0) {
-                CERROR ("Error %d reading HELLO from %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
-                LASSERT (rc < 0 && rc != -EALREADY);
-                return rc;
-        }
-
-        if (conn->ksnc_flip) {
-                __swab32s(&hello->kshm_src_pid);
-                __swab64s(&hello->kshm_src_nid);
-                __swab32s(&hello->kshm_dst_pid);
-                __swab64s(&hello->kshm_dst_nid);
-                __swab64s(&hello->kshm_src_incarnation);
-                __swab64s(&hello->kshm_dst_incarnation);
-                __swab32s(&hello->kshm_ctype);
-                __swab32s(&hello->kshm_nips);
-        }
-
-        if (hello->kshm_nips > LNET_MAX_INTERFACES) {
-                CERROR("Bad nips %d from ip %u.%u.%u.%u\n",
-                       hello->kshm_nips, HIPQUAD(conn->ksnc_ipaddr));
-                return -EPROTO;
-        }
+                version = hello->kshm_version;
+        else if (hello->kshm_magic == __swab32(LNET_PROTO_MAGIC))
+                version = __swab32(hello->kshm_version);
+
+        if (version != 0) {
+#if SOCKNAL_VERSION_DEBUG
+                if (*ksocknal_tunables.ksnd_protocol == 1)
+                        return NULL;
+
+                if (*ksocknal_tunables.ksnd_protocol == 2 &&
+                    version == KSOCK_PROTO_V3)
+                        return NULL;
+#endif
+                if (version == KSOCK_PROTO_V2)
+                        return &ksocknal_protocol_v2x;
 
-        if (hello->kshm_nips == 0)
-                return 0;
-        
-        rc = libcfs_sock_read(sock, hello->kshm_ips,
-                              hello->kshm_nips * sizeof(__u32), timeout);
-        if (rc != 0) {
-                CERROR ("Error %d reading IPs from ip %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
-                LASSERT (rc < 0 && rc != -EALREADY);
-                return rc;
-        }
+                if (version == KSOCK_PROTO_V3)
+                        return &ksocknal_protocol_v3x;
 
-        for (i = 0; i < hello->kshm_nips; i++) {
-                if (conn->ksnc_flip)
-                        __swab32s(&hello->kshm_ips[i]);
-                
-                if (hello->kshm_ips[i] == 0) {
-                        CERROR("Zero IP[%d] from ip %u.%u.%u.%u\n",
-                               i, HIPQUAD(conn->ksnc_ipaddr));
-                        return -EPROTO;
-                }
+                return NULL;
         }
 
-        return 0;
-}
-
-static void
-ksocknal_pack_msg_v1(ksock_tx_t *tx)
-{
-        /* V1.x has no KSOCK_MSG_NOOP */
-        LASSERT(tx->tx_msg.ksm_type != KSOCK_MSG_NOOP);
-        LASSERT(tx->tx_lnetmsg != NULL);
-
-        tx->tx_iov[0].iov_base = (void *)&tx->tx_lnetmsg->msg_hdr;
-        tx->tx_iov[0].iov_len  = sizeof(lnet_hdr_t);
-
-        tx->tx_resid = tx->tx_nob = tx->tx_lnetmsg->msg_len + sizeof(lnet_hdr_t);
-}
-
-static void
-ksocknal_pack_msg_v2(ksock_tx_t *tx)
-{
-        tx->tx_iov[0].iov_base = (void *)&tx->tx_msg;
+        if (hello->kshm_magic == le32_to_cpu(LNET_PROTO_TCP_MAGIC)) {
+               struct lnet_magicversion *hmv;
 
-        if (tx->tx_lnetmsg != NULL) {
-                LASSERT(tx->tx_msg.ksm_type != KSOCK_MSG_NOOP);
+               CLASSERT(sizeof(struct lnet_magicversion) ==
+                        offsetof(struct ksock_hello_msg, kshm_src_nid));
 
-                tx->tx_msg.ksm_u.lnetmsg.ksnm_hdr = tx->tx_lnetmsg->msg_hdr;
-                tx->tx_iov[0].iov_len = offsetof(ksock_msg_t, ksm_u.lnetmsg.ksnm_payload);
-                tx->tx_resid = tx->tx_nob = offsetof(ksock_msg_t,  ksm_u.lnetmsg.ksnm_payload) +
-                                            tx->tx_lnetmsg->msg_len;
-        } else {
-                LASSERT(tx->tx_msg.ksm_type == KSOCK_MSG_NOOP);
+               hmv = (struct lnet_magicversion *)hello;
 
-                tx->tx_iov[0].iov_len = offsetof(ksock_msg_t, ksm_u.lnetmsg.ksnm_hdr);
-                tx->tx_resid = tx->tx_nob = offsetof(ksock_msg_t,  ksm_u.lnetmsg.ksnm_hdr);
+                if (hmv->version_major == cpu_to_le16 (KSOCK_PROTO_V1_MAJOR) &&
+                    hmv->version_minor == cpu_to_le16 (KSOCK_PROTO_V1_MINOR))
+                        return &ksocknal_protocol_v1x;
         }
-        /* Don't checksum before start sending, because packet can be piggybacked with ACK */
-}
-
-static void
-ksocknal_unpack_msg_v1(ksock_msg_t *msg)
-{
-        msg->ksm_type           = KSOCK_MSG_LNET;
-        msg->ksm_csum           = 0;
-        msg->ksm_zc_req_cookie  = 0;
-        msg->ksm_zc_ack_cookie  = 0;
-}
 
-static void
-ksocknal_unpack_msg_v2(ksock_msg_t *msg)
-{
-        return;  /* Do nothing */
+        return NULL;
 }
 
-ksock_protocol_t  ksocknal_protocol_v1x =
-{
-        KSOCK_PROTO_V1,
-        ksocknal_send_hello_v1,
-        ksocknal_recv_hello_v1,
-        ksocknal_pack_msg_v1,
-        ksocknal_unpack_msg_v1
-};
-
-ksock_protocol_t  ksocknal_protocol_v2x =
-{
-        KSOCK_PROTO_V2,
-        ksocknal_send_hello_v2,
-        ksocknal_recv_hello_v2,
-        ksocknal_pack_msg_v2,
-        ksocknal_unpack_msg_v2
-};
-
 int
-ksocknal_send_hello (lnet_ni_t *ni, ksock_conn_t *conn,
-                     lnet_nid_t peer_nid, ksock_hello_msg_t *hello)
+ksocknal_send_hello(struct lnet_ni *ni, struct ksock_conn *conn,
+                   lnet_nid_t peer_nid, struct ksock_hello_msg *hello)
 {
-        /* CAVEAT EMPTOR: this byte flips 'ipaddrs' */
-        ksock_net_t         *net = (ksock_net_t *)ni->ni_data;
-        lnet_nid_t           srcnid;
+       /* CAVEAT EMPTOR: this byte flips 'ipaddrs' */
+       struct ksock_net *net = (struct ksock_net *)ni->ni_data;
 
-        LASSERT (0 <= hello->kshm_nips && hello->kshm_nips <= LNET_MAX_INTERFACES);
+       LASSERT(hello->kshm_nips <= LNET_INTERFACES_NUM);
 
-        /* No need for getconnsock/putconnsock */
-        LASSERT (!conn->ksnc_closing);
-        LASSERT (conn->ksnc_proto != NULL);
+       /* rely on caller to hold a ref on socket so it wouldn't disappear */
+       LASSERT(conn->ksnc_proto != NULL);
 
-        srcnid = lnet_ptlcompat_srcnid(ni->ni_nid, peer_nid);
+       hello->kshm_src_nid         = ni->ni_nid;
+       hello->kshm_dst_nid         = peer_nid;
+       hello->kshm_src_pid         = the_lnet.ln_pid;
 
-        hello->kshm_src_nid         = srcnid;
-        hello->kshm_dst_nid         = peer_nid;
-        hello->kshm_src_pid         = the_lnet.ln_pid;
+       hello->kshm_src_incarnation = net->ksnn_incarnation;
+       hello->kshm_ctype           = conn->ksnc_type;
 
-        hello->kshm_src_incarnation = net->ksnn_incarnation;
-        hello->kshm_ctype           = conn->ksnc_type;
-
-        return conn->ksnc_proto->pro_send_hello(conn, hello);
+       return conn->ksnc_proto->pro_send_hello(conn, hello);
 }
 
-int
+static int
 ksocknal_invert_type(int type)
 {
         switch (type)
@@ -2147,27 +1786,36 @@ ksocknal_invert_type(int type)
 }
 
 int
-ksocknal_recv_hello (lnet_ni_t *ni, ksock_conn_t *conn, 
-                     ksock_hello_msg_t *hello, lnet_process_id_t *peerid,
-                     __u64 *incarnation)
+ksocknal_recv_hello(struct lnet_ni *ni, struct ksock_conn *conn,
+                   struct ksock_hello_msg *hello,
+                   struct lnet_process_id *peerid,
+                   __u64 *incarnation)
 {
-        cfs_socket_t        *sock = conn->ksnc_sock;
-        int                  active;
+        /* Return < 0        fatal error
+         *        0          success
+         *        EALREADY   lost connection race
+         *        EPROTO     protocol version mismatch
+         */
+       struct socket        *sock = conn->ksnc_sock;
+        int                  active = (conn->ksnc_proto != NULL);
         int                  timeout;
-        int                  match = 0;
+        int                  proto_match;
         int                  rc;
-        ksock_protocol_t    *proto;
-        lnet_process_id_t    recv_id;
+       struct ksock_proto *proto;
+       struct lnet_process_id recv_id;
 
-        active = (peerid->nid != LNET_NID_ANY);
-        timeout = active ? *ksocknal_tunables.ksnd_timeout :
-                            lnet_acceptor_timeout();
+       /* socket type set on active connections - not set on passive */
+       LASSERT(!active == !(conn->ksnc_type != SOCKLND_CONN_NONE));
 
-        rc = libcfs_sock_read(sock, &hello->kshm_magic, sizeof (hello->kshm_magic), timeout);
+       timeout = active ? lnet_get_lnd_timeout() :
+                           lnet_acceptor_timeout();
+
+       rc = lnet_sock_read(sock, &hello->kshm_magic,
+                           sizeof(hello->kshm_magic), timeout);
         if (rc != 0) {
-                CERROR ("Error %d reading HELLO from %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
-                LASSERT (rc < 0 && rc != -EALREADY);
+               CERROR("Error %d reading HELLO from %pI4h\n",
+                      rc, &conn->ksnc_ipaddr);
+                LASSERT (rc < 0);
                 return rc;
         }
 
@@ -2175,162 +1823,128 @@ ksocknal_recv_hello (lnet_ni_t *ni, ksock_conn_t *conn,
             hello->kshm_magic != __swab32(LNET_PROTO_MAGIC) &&
             hello->kshm_magic != le32_to_cpu (LNET_PROTO_TCP_MAGIC)) {
                 /* Unexpected magic! */
-                if (active ||
-                    the_lnet.ln_ptlcompat == 0) {
-                        CERROR ("Bad magic(1) %#08x (%#08x expected) from "
-                                "%u.%u.%u.%u\n", __cpu_to_le32 (hello->kshm_magic),
-                                LNET_PROTO_TCP_MAGIC,
-                                HIPQUAD(conn->ksnc_ipaddr));
-                        return -EPROTO;
-                }
-
-                /* When portals compatibility is set, I may be passed a new
-                 * connection "blindly" by the acceptor, and I have to
-                 * determine if my peer has sent an acceptor connection request
-                 * or not.  This isn't a 'hello', so I'll get the acceptor to
-                 * look at it... */
-                rc = lnet_accept(ni, sock, hello->kshm_magic);
-                if (rc != 0)
-                        return -EPROTO;
-
-                /* ...and if it's OK I'm back to looking for a 'hello'... */
-                rc = libcfs_sock_read(sock, &hello->kshm_magic, 
-                                      sizeof (hello->kshm_magic), timeout);
-                if (rc != 0) {
-                        CERROR ("Error %d reading HELLO from %u.%u.%u.%u\n",
-                                rc, HIPQUAD(conn->ksnc_ipaddr));
-                        LASSERT (rc < 0 && rc != -EALREADY);
-                        return rc;
-                }
-        
-                /* Only need to check V1.x magic */
-                if (hello->kshm_magic != le32_to_cpu (LNET_PROTO_TCP_MAGIC)) {
-                        CERROR ("Bad magic(2) %#08x (%#08x expected) from "
-                                "%u.%u.%u.%u\n", __cpu_to_le32 (hello->kshm_magic),
-                                LNET_PROTO_TCP_MAGIC,
-                                HIPQUAD(conn->ksnc_ipaddr));
-                        return -EPROTO;
-                }
+                CERROR ("Bad magic(1) %#08x (%#08x expected) from "
+                       "%pI4h\n", __cpu_to_le32 (hello->kshm_magic),
+                       LNET_PROTO_TCP_MAGIC, &conn->ksnc_ipaddr);
+                return -EPROTO;
         }
 
-        rc = libcfs_sock_read(sock, &hello->kshm_version,
-                              sizeof(hello->kshm_version), timeout);
+       rc = lnet_sock_read(sock, &hello->kshm_version,
+                           sizeof(hello->kshm_version), timeout);
         if (rc != 0) {
-                CERROR ("Error %d reading HELLO from %u.%u.%u.%u\n",
-                        rc, HIPQUAD(conn->ksnc_ipaddr));
-                LASSERT (rc < 0 && rc != -EALREADY);
+               CERROR("Error %d reading HELLO from %pI4h\n",
+                      rc, &conn->ksnc_ipaddr);
+               LASSERT(rc < 0);
                 return rc;
         }
 
-        proto = ksocknal_compat_protocol(hello);
+        proto = ksocknal_parse_proto_version(hello);
         if (proto == NULL) {
-                if (!active) { 
-                        /* unknown protocol from peer, tell peer my protocol */
-                        conn->ksnc_proto = &ksocknal_protocol_v2x;
+                if (!active) {
+                        /* unknown protocol from peer_ni, tell peer_ni my protocol */
+                        conn->ksnc_proto = &ksocknal_protocol_v3x;
+#if SOCKNAL_VERSION_DEBUG
+                        if (*ksocknal_tunables.ksnd_protocol == 2)
+                                conn->ksnc_proto = &ksocknal_protocol_v2x;
+                        else if (*ksocknal_tunables.ksnd_protocol == 1)
+                                conn->ksnc_proto = &ksocknal_protocol_v1x;
+#endif
                         hello->kshm_nips = 0;
                         ksocknal_send_hello(ni, conn, ni->ni_nid, hello);
                 }
 
-                CERROR ("Unknown protocol version (%d.x expected)"
-                        " from %u.%u.%u.%u\n",
-                        conn->ksnc_proto->pro_version,
-                        HIPQUAD(conn->ksnc_ipaddr));
+               CERROR("Unknown protocol version (%d.x expected) from %pI4h\n",
+                      conn->ksnc_proto->pro_version, &conn->ksnc_ipaddr);
 
                 return -EPROTO;
         }
 
-        if (conn->ksnc_proto == proto)
-                match = 1;
-
+        proto_match = (conn->ksnc_proto == proto);
         conn->ksnc_proto = proto;
 
         /* receive the rest of hello message anyway */
         rc = conn->ksnc_proto->pro_recv_hello(conn, hello, timeout);
         if (rc != 0) {
-                CERROR("Error %d reading or checking hello from from %u.%u.%u.%u\n",
-                       rc, HIPQUAD(conn->ksnc_ipaddr));
+               CERROR("Error %d reading or checking hello from from %pI4h\n",
+                      rc, &conn->ksnc_ipaddr);
+                LASSERT (rc < 0);
                 return rc;
         }
 
+        *incarnation = hello->kshm_src_incarnation;
+
         if (hello->kshm_src_nid == LNET_NID_ANY) {
                 CERROR("Expecting a HELLO hdr with a NID, but got LNET_NID_ANY"
-                       "from %u.%u.%u.%u\n", HIPQUAD(conn->ksnc_ipaddr));
+                      "from %pI4h\n", &conn->ksnc_ipaddr);
                 return -EPROTO;
         }
 
-        if (conn->ksnc_port > LNET_ACCEPTOR_MAX_RESERVED_PORT) {          
-                /* Userspace NAL assigns peer process ID from socket */
+        if (!active &&
+            conn->ksnc_port > LNET_ACCEPTOR_MAX_RESERVED_PORT) {
+                /* Userspace NAL assigns peer_ni process ID from socket */
                 recv_id.pid = conn->ksnc_port | LNET_PID_USERFLAG;
                 recv_id.nid = LNET_MKNID(LNET_NIDNET(ni->ni_nid), conn->ksnc_ipaddr);
         } else {
                 recv_id.nid = hello->kshm_src_nid;
-
-                if (the_lnet.ln_ptlcompat > 1 && /* portals peers may exist */
-                    LNET_NIDNET(recv_id.nid) == 0) /* this is one */
-                        recv_id.pid = the_lnet.ln_pid; /* give it a sensible pid */
-                else
-                        recv_id.pid = hello->kshm_src_pid;
-
+                recv_id.pid = hello->kshm_src_pid;
         }
-        
-        if (!active) {                          /* don't know peer's nid yet */
+
+        if (!active) {
                 *peerid = recv_id;
-        } else if (peerid->pid != recv_id.pid ||
-                   !lnet_ptlcompat_matchnid(peerid->nid, recv_id.nid)) {
-                LCONSOLE_ERROR(0x130, "Connected successfully to %s on host "
-                               "%u.%u.%u.%u, but they claimed they were "
-                               "%s; please check your Lustre "
-                               "configuration.\n",
-                               libcfs_id2str(*peerid),
-                               HIPQUAD(conn->ksnc_ipaddr),
-                               libcfs_id2str(recv_id));
-                return -EPROTO;
-        }
 
-        if (conn->ksnc_type == SOCKLND_CONN_NONE) {
-                /* I've accepted this connection; peer determines type */
-                conn->ksnc_type = ksocknal_invert_type(hello->kshm_ctype);
-                if (conn->ksnc_type == SOCKLND_CONN_NONE) {
-                        CERROR ("Unexpected type %d from %s ip %u.%u.%u.%u\n",
-                                hello->kshm_ctype, libcfs_id2str(*peerid), 
-                                HIPQUAD(conn->ksnc_ipaddr));
-                        return -EPROTO;
-                }
-        } else if (hello->kshm_ctype == SOCKLND_CONN_NONE) {
-                if (match) {
-                        /* lost a connection race */
-                        return -EALREADY;
-                }
-                /* unmatched protocol get SOCKLND_CONN_NONE anyway */
-        } else if (ksocknal_invert_type(hello->kshm_ctype) != conn->ksnc_type) {
-                CERROR ("Mismatched types: me %d, %s ip %u.%u.%u.%u %d\n",
-                        conn->ksnc_type, libcfs_id2str(*peerid), 
-                        HIPQUAD(conn->ksnc_ipaddr),
-                        hello->kshm_ctype);
+               /* peer_ni determines type */
+               conn->ksnc_type = ksocknal_invert_type(hello->kshm_ctype);
+               if (conn->ksnc_type == SOCKLND_CONN_NONE) {
+                       CERROR("Unexpected type %d from %s ip %pI4h\n",
+                              hello->kshm_ctype, libcfs_id2str(*peerid),
+                              &conn->ksnc_ipaddr);
+                       return -EPROTO;
+               }
+               return 0;
+       }
+
+        if (peerid->pid != recv_id.pid ||
+            peerid->nid != recv_id.nid) {
+                LCONSOLE_ERROR_MSG(0x130, "Connected successfully to %s on host"
+                                  " %pI4h, but they claimed they were "
+                                   "%s; please check your Lustre "
+                                   "configuration.\n",
+                                   libcfs_id2str(*peerid),
+                                  &conn->ksnc_ipaddr,
+                                   libcfs_id2str(recv_id));
                 return -EPROTO;
         }
 
-        *incarnation = hello->kshm_src_incarnation;
+        if (hello->kshm_ctype == SOCKLND_CONN_NONE) {
+                /* Possible protocol mismatch or I lost the connection race */
+                return proto_match ? EALREADY : EPROTO;
+        }
 
-        return 0;
+       if (ksocknal_invert_type(hello->kshm_ctype) != conn->ksnc_type) {
+               CERROR("Mismatched types: me %d, %s ip %pI4h %d\n",
+                      conn->ksnc_type, libcfs_id2str(*peerid),
+                      &conn->ksnc_ipaddr,
+                      hello->kshm_ctype);
+               return -EPROTO;
+       }
+       return 0;
 }
 
-void
-ksocknal_connect (ksock_route_t *route)
+static int
+ksocknal_connect(struct ksock_route *route)
 {
-        CFS_LIST_HEAD    (zombies);
-        ksock_peer_t     *peer = route->ksnr_peer;
+       LIST_HEAD(zombies);
+       struct ksock_peer_ni *peer_ni = route->ksnr_peer;
         int               type;
         int               wanted;
-        cfs_socket_t     *sock;
-        cfs_time_t        deadline;
+       struct socket     *sock;
+       time64_t deadline;
         int               retry_later = 0;
         int               rc = 0;
 
-        deadline = cfs_time_add(cfs_time_current(), 
-                                cfs_time_seconds(*ksocknal_tunables.ksnd_timeout));
+       deadline = ktime_get_seconds() + lnet_get_lnd_timeout();
 
-        write_lock_bh (&ksocknal_data.ksnd_global_lock);
+       write_lock_bh(&ksocknal_data.ksnd_global_lock);
 
         LASSERT (route->ksnr_scheduled);
         LASSERT (!route->ksnr_connecting);
@@ -2340,25 +1954,25 @@ ksocknal_connect (ksock_route_t *route)
         for (;;) {
                 wanted = ksocknal_route_mask() & ~route->ksnr_connected;
 
-                /* stop connecting if peer/route got closed under me, or
+                /* stop connecting if peer_ni/route got closed under me, or
                  * route got connected while queued */
-                if (peer->ksnp_closing || route->ksnr_deleted ||
+                if (peer_ni->ksnp_closing || route->ksnr_deleted ||
                     wanted == 0) {
                         retry_later = 0;
                         break;
                 }
 
-                /* reschedule if peer is connecting to me */
-                if (peer->ksnp_accepting > 0) {
+                /* reschedule if peer_ni is connecting to me */
+                if (peer_ni->ksnp_accepting > 0) {
                         CDEBUG(D_NET,
-                               "peer %s(%d) already connecting to me, retry later.\n",
-                               libcfs_nid2str(peer->ksnp_id.nid), peer->ksnp_accepting);
+                               "peer_ni %s(%d) already connecting to me, retry later.\n",
+                               libcfs_nid2str(peer_ni->ksnp_id.nid), peer_ni->ksnp_accepting);
                         retry_later = 1;
                 }
 
                 if (retry_later) /* needs reschedule */
                         break;
-                        
+
                 if ((wanted & (1 << SOCKLND_CONN_ANY)) != 0) {
                         type = SOCKLND_CONN_ANY;
                 } else if ((wanted & (1 << SOCKLND_CONN_CONTROL)) != 0) {
@@ -2370,43 +1984,39 @@ ksocknal_connect (ksock_route_t *route)
                         type = SOCKLND_CONN_BULK_OUT;
                 }
 
-                write_unlock_bh (&ksocknal_data.ksnd_global_lock);
+               write_unlock_bh(&ksocknal_data.ksnd_global_lock);
 
-                if (cfs_time_aftereq(cfs_time_current(), deadline)) {
+               if (ktime_get_seconds() >= deadline) {
                         rc = -ETIMEDOUT;
-                        lnet_connect_console_error(rc, peer->ksnp_id.nid,
+                        lnet_connect_console_error(rc, peer_ni->ksnp_id.nid,
                                                    route->ksnr_ipaddr,
                                                    route->ksnr_port);
                         goto failed;
                 }
-                
-                rc = lnet_connect(&sock, peer->ksnp_id.nid,
-                                  route->ksnr_myipaddr, 
-                                  route->ksnr_ipaddr, route->ksnr_port);
-                if (rc != 0)
-                        goto failed;
 
-                rc = ksocknal_create_conn(peer->ksnp_ni, route, sock, type);
+               rc = lnet_connect(&sock, peer_ni->ksnp_id.nid,
+                                 route->ksnr_myipaddr,
+                                 route->ksnr_ipaddr, route->ksnr_port,
+                                 peer_ni->ksnp_ni->ni_net_ns);
+               if (rc != 0)
+                       goto failed;
 
+                rc = ksocknal_create_conn(peer_ni->ksnp_ni, route, sock, type);
                 if (rc < 0) {
-                        lnet_connect_console_error(rc, peer->ksnp_id.nid,
-                                                   route->ksnr_ipaddr, 
+                        lnet_connect_console_error(rc, peer_ni->ksnp_id.nid,
+                                                   route->ksnr_ipaddr,
                                                    route->ksnr_port);
                         goto failed;
                 }
 
-                /* rc == EALREADY means I lost a connection race and my
-                 * peer is connecting to me.
-                 * rc == EPROTO means my peer is speaking an older 
-                 * protocol version. */
-                LASSERT (rc == 0 || rc == EALREADY || rc == EPROTO);
-
-                retry_later = rc != 0;
+                /* A +ve RC means I have to retry because I lost the connection
+                 * race or I have to renegotiate protocol version */
+                retry_later = (rc != 0);
                 if (retry_later)
-                        CDEBUG(D_NET, "peer %s: conn race, retry later.\n",
-                               libcfs_nid2str(peer->ksnp_id.nid));
-                
-                write_lock_bh (&ksocknal_data.ksnd_global_lock);
+                        CDEBUG(D_NET, "peer_ni %s: conn race, retry later.\n",
+                               libcfs_nid2str(peer_ni->ksnp_id.nid));
+
+               write_lock_bh(&ksocknal_data.ksnd_global_lock);
         }
 
         route->ksnr_scheduled = 0;
@@ -2414,191 +2024,352 @@ ksocknal_connect (ksock_route_t *route)
 
         if (retry_later) {
                 /* re-queue for attention; this frees me up to handle
-                 * the peer's incoming connection request */
+                 * the peer_ni's incoming connection request */
+
+                if (rc == EALREADY ||
+                    (rc == 0 && peer_ni->ksnp_accepting > 0)) {
+                        /* We want to introduce a delay before next
+                         * attempt to connect if we lost conn race,
+                         * but the race is resolved quickly usually,
+                         * so min_reconnectms should be good heuristic */
+                       route->ksnr_retry_interval = *ksocknal_tunables.ksnd_min_reconnectms / 1000;
+                       route->ksnr_timeout = ktime_get_seconds() +
+                                             route->ksnr_retry_interval;
+                }
+
                 ksocknal_launch_connection_locked(route);
         }
 
-        write_unlock_bh (&ksocknal_data.ksnd_global_lock);
-        return;
+       write_unlock_bh(&ksocknal_data.ksnd_global_lock);
+        return retry_later;
 
  failed:
-        write_lock_bh (&ksocknal_data.ksnd_global_lock);
+       write_lock_bh(&ksocknal_data.ksnd_global_lock);
 
         route->ksnr_scheduled = 0;
         route->ksnr_connecting = 0;
 
-        /* This is a retry rather than a new connection */
-        route->ksnr_retry_interval *= 2;
-        route->ksnr_retry_interval = 
-                MAX(route->ksnr_retry_interval,
-                    cfs_time_seconds(*ksocknal_tunables.ksnd_min_reconnectms)/1000);
-        route->ksnr_retry_interval = 
-                MIN(route->ksnr_retry_interval,
-                    cfs_time_seconds(*ksocknal_tunables.ksnd_max_reconnectms)/1000);
-        
-        LASSERT (route->ksnr_retry_interval != 0);
-        route->ksnr_timeout = cfs_time_add(cfs_time_current(),
-                                           route->ksnr_retry_interval);
-
-        if (!list_empty(&peer->ksnp_tx_queue) &&
-            peer->ksnp_accepting == 0 &&
-            ksocknal_find_connecting_route_locked(peer) == NULL) {
+       /* This is a retry rather than a new connection */
+       route->ksnr_retry_interval *= 2;
+       route->ksnr_retry_interval =
+               max_t(time64_t, route->ksnr_retry_interval,
+                     *ksocknal_tunables.ksnd_min_reconnectms / 1000);
+       route->ksnr_retry_interval =
+               min_t(time64_t, route->ksnr_retry_interval,
+                     *ksocknal_tunables.ksnd_max_reconnectms / 1000);
+
+       LASSERT(route->ksnr_retry_interval);
+       route->ksnr_timeout = ktime_get_seconds() + route->ksnr_retry_interval;
+
+       if (!list_empty(&peer_ni->ksnp_tx_queue) &&
+            peer_ni->ksnp_accepting == 0 &&
+            ksocknal_find_connecting_route_locked(peer_ni) == NULL) {
+               struct ksock_conn *conn;
+
                 /* ksnp_tx_queue is queued on a conn on successful
-                 * connection */
-                LASSERT (list_empty (&peer->ksnp_conns));
+                 * connection for V1.x and V2.x */
+               if (!list_empty(&peer_ni->ksnp_conns)) {
+                       conn = list_entry(peer_ni->ksnp_conns.next,
+                                         struct ksock_conn, ksnc_list);
+                        LASSERT (conn->ksnc_proto == &ksocknal_protocol_v3x);
+                }
 
                 /* take all the blocked packets while I've got the lock and
                  * complete below... */
-                list_add(&zombies, &peer->ksnp_tx_queue);
-                list_del_init(&peer->ksnp_tx_queue);
+               list_splice_init(&peer_ni->ksnp_tx_queue, &zombies);
         }
 
-#if 0           /* irrelevent with only eager routes */
-        if (!route->ksnr_deleted) {
-                /* make this route least-favourite for re-selection */
-                list_del(&route->ksnr_list);
-                list_add_tail(&route->ksnr_list, &peer->ksnp_routes);
+       write_unlock_bh(&ksocknal_data.ksnd_global_lock);
+
+       ksocknal_peer_failed(peer_ni);
+       ksocknal_txlist_done(peer_ni->ksnp_ni, &zombies, rc);
+       return 0;
+}
+
+/*
+ * check whether we need to create more connds.
+ * It will try to create new thread if it's necessary, @timeout can
+ * be updated if failed to create, so caller wouldn't keep try while
+ * running out of resource.
+ */
+static int
+ksocknal_connd_check_start(time64_t sec, long *timeout)
+{
+       char name[16];
+        int rc;
+        int total = ksocknal_data.ksnd_connd_starting +
+                    ksocknal_data.ksnd_connd_running;
+
+        if (unlikely(ksocknal_data.ksnd_init < SOCKNAL_INIT_ALL)) {
+                /* still in initializing */
+                return 0;
+        }
+
+        if (total >= *ksocknal_tunables.ksnd_nconnds_max ||
+            total > ksocknal_data.ksnd_connd_connecting + SOCKNAL_CONND_RESV) {
+                /* can't create more connd, or still have enough
+                 * threads to handle more connecting */
+                return 0;
+        }
+
+        if (list_empty(&ksocknal_data.ksnd_connd_routes)) {
+                /* no pending connecting request */
+                return 0;
+        }
+
+        if (sec - ksocknal_data.ksnd_connd_failed_stamp <= 1) {
+                /* may run out of resource, retry later */
+                *timeout = cfs_time_seconds(1);
+                return 0;
         }
-#endif
-        write_unlock_bh (&ksocknal_data.ksnd_global_lock);
 
-        ksocknal_peer_failed(peer);
-        ksocknal_txlist_done(peer->ksnp_ni, &zombies, 1);
+        if (ksocknal_data.ksnd_connd_starting > 0) {
+                /* serialize starting to avoid flood */
+                return 0;
+        }
+
+        ksocknal_data.ksnd_connd_starting_stamp = sec;
+        ksocknal_data.ksnd_connd_starting++;
+       spin_unlock_bh(&ksocknal_data.ksnd_connd_lock);
+
+       /* NB: total is the next id */
+       snprintf(name, sizeof(name), "socknal_cd%02d", total);
+       rc = ksocknal_thread_start(ksocknal_connd, NULL, name);
+
+       spin_lock_bh(&ksocknal_data.ksnd_connd_lock);
+        if (rc == 0)
+                return 1;
+
+        /* we tried ... */
+        LASSERT(ksocknal_data.ksnd_connd_starting > 0);
+        ksocknal_data.ksnd_connd_starting--;
+       ksocknal_data.ksnd_connd_failed_stamp = ktime_get_real_seconds();
+
+        return 1;
 }
 
-static inline int
-ksocknal_connd_connect_route_locked(void)
+/*
+ * check whether current thread can exit, it will return 1 if there are too
+ * many threads and no creating in past 120 seconds.
+ * Also, this function may update @timeout to make caller come back
+ * again to recheck these conditions.
+ */
+static int
+ksocknal_connd_check_stop(time64_t sec, long *timeout)
 {
-        /* Only handle an outgoing connection request if there is someone left
-         * to handle incoming connections */
-        return !list_empty(&ksocknal_data.ksnd_connd_routes) &&
-                ((ksocknal_data.ksnd_connd_connecting + 1) <
-                 *ksocknal_tunables.ksnd_nconnds);
+        int val;
+
+        if (unlikely(ksocknal_data.ksnd_init < SOCKNAL_INIT_ALL)) {
+                /* still in initializing */
+                return 0;
+        }
+
+        if (ksocknal_data.ksnd_connd_starting > 0) {
+                /* in progress of starting new thread */
+                return 0;
+        }
+
+        if (ksocknal_data.ksnd_connd_running <=
+            *ksocknal_tunables.ksnd_nconnds) { /* can't shrink */
+                return 0;
+        }
+
+        /* created thread in past 120 seconds? */
+        val = (int)(ksocknal_data.ksnd_connd_starting_stamp +
+                    SOCKNAL_CONND_TIMEOUT - sec);
+
+        *timeout = (val > 0) ? cfs_time_seconds(val) :
+                               cfs_time_seconds(SOCKNAL_CONND_TIMEOUT);
+        if (val > 0)
+                return 0;
+
+        /* no creating in past 120 seconds */
+
+        return ksocknal_data.ksnd_connd_running >
+               ksocknal_data.ksnd_connd_connecting + SOCKNAL_CONND_RESV;
 }
 
-static inline int
-ksocknal_connd_ready(void)
+/* Go through connd_routes queue looking for a route that we can process
+ * right now, @timeout_p can be updated if we need to come back later */
+static struct ksock_route *
+ksocknal_connd_get_route_locked(signed long *timeout_p)
 {
-        int            rc;
-        
-        spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
-        
-        rc = ksocknal_data.ksnd_shuttingdown ||
-             !list_empty(&ksocknal_data.ksnd_connd_connreqs) ||
-             ksocknal_connd_connect_route_locked();
-        
-        spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
-
-        return rc;
+       time64_t now = ktime_get_seconds();
+       struct ksock_route *route;
+
+       /* connd_routes can contain both pending and ordinary routes */
+       list_for_each_entry(route, &ksocknal_data.ksnd_connd_routes,
+                                ksnr_connd_list) {
+
+               if (route->ksnr_retry_interval == 0 ||
+                   now >= route->ksnr_timeout)
+                       return route;
+
+               if (*timeout_p == MAX_SCHEDULE_TIMEOUT ||
+                   *timeout_p > cfs_time_seconds(route->ksnr_timeout - now))
+                       *timeout_p = cfs_time_seconds(route->ksnr_timeout - now);
+       }
+
+       return NULL;
 }
 
 int
-ksocknal_connd (void *arg)
+ksocknal_connd(void *arg)
 {
-        long               id = (long)arg;
-        char               name[16];
-        ksock_connreq_t   *cr;
-        ksock_route_t     *route;
-
-        snprintf (name, sizeof (name), "socknal_cd%02ld", id);
-        cfs_daemonize (name);
-        cfs_block_allsigs ();
+       spinlock_t *connd_lock = &ksocknal_data.ksnd_connd_lock;
+       struct ksock_connreq *cr;
+       wait_queue_entry_t wait;
+       int nloops = 0;
+       int cons_retry = 0;
 
-        spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
+       cfs_block_allsigs();
 
-        while (!ksocknal_data.ksnd_shuttingdown) {
+       init_waitqueue_entry(&wait, current);
 
-                if (!list_empty(&ksocknal_data.ksnd_connd_connreqs)) {
-                        /* Connection accepted by the listener */
-                        cr = list_entry(ksocknal_data.ksnd_connd_connreqs.next,
-                                        ksock_connreq_t, ksncr_list);
-                        
-                        list_del(&cr->ksncr_list);
-                        spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
-                        
-                        ksocknal_create_conn(cr->ksncr_ni, NULL, 
-                                             cr->ksncr_sock, SOCKLND_CONN_NONE);
-                        lnet_ni_decref(cr->ksncr_ni);
-                        LIBCFS_FREE(cr, sizeof(*cr));
-                        
-                        spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
-                }
+       spin_lock_bh(connd_lock);
 
-                if (ksocknal_connd_connect_route_locked()) {
-                        /* Connection request */
-                        route = list_entry (ksocknal_data.ksnd_connd_routes.next,
-                                            ksock_route_t, ksnr_connd_list);
+       LASSERT(ksocknal_data.ksnd_connd_starting > 0);
+       ksocknal_data.ksnd_connd_starting--;
+       ksocknal_data.ksnd_connd_running++;
 
-                        list_del (&route->ksnr_connd_list);
-                        ksocknal_data.ksnd_connd_connecting++;
-                        spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
+       while (!ksocknal_data.ksnd_shuttingdown) {
+               struct ksock_route *route = NULL;
+               time64_t sec = ktime_get_real_seconds();
+               long timeout = MAX_SCHEDULE_TIMEOUT;
+               int  dropped_lock = 0;
 
-                        ksocknal_connect (route);
-                        ksocknal_route_decref(route);
+               if (ksocknal_connd_check_stop(sec, &timeout)) {
+                       /* wakeup another one to check stop */
+                       wake_up(&ksocknal_data.ksnd_connd_waitq);
+                       break;
+               }
 
-                        spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
-                        ksocknal_data.ksnd_connd_connecting--;
+                if (ksocknal_connd_check_start(sec, &timeout)) {
+                        /* created new thread */
+                        dropped_lock = 1;
                 }
 
-                spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
+               if (!list_empty(&ksocknal_data.ksnd_connd_connreqs)) {
+                        /* Connection accepted by the listener */
+                       cr = list_entry(ksocknal_data.ksnd_connd_connreqs.next,
+                                       struct ksock_connreq, ksncr_list);
 
-                wait_event_interruptible_exclusive(
-                        ksocknal_data.ksnd_connd_waitq,
-                        ksocknal_connd_ready());
+                       list_del(&cr->ksncr_list);
+                       spin_unlock_bh(connd_lock);
+                       dropped_lock = 1;
 
-                spin_lock_bh (&ksocknal_data.ksnd_connd_lock);
-        }
+                       ksocknal_create_conn(cr->ksncr_ni, NULL,
+                                            cr->ksncr_sock, SOCKLND_CONN_NONE);
+                       lnet_ni_decref(cr->ksncr_ni);
+                       LIBCFS_FREE(cr, sizeof(*cr));
 
-        spin_unlock_bh (&ksocknal_data.ksnd_connd_lock);
+                       spin_lock_bh(connd_lock);
+                }
 
-        ksocknal_thread_fini ();
-        return (0);
+                /* Only handle an outgoing connection request if there
+                 * is a thread left to handle incoming connections and
+                 * create new connd */
+                if (ksocknal_data.ksnd_connd_connecting + SOCKNAL_CONND_RESV <
+                    ksocknal_data.ksnd_connd_running) {
+                        route = ksocknal_connd_get_route_locked(&timeout);
+                }
+                if (route != NULL) {
+                       list_del(&route->ksnr_connd_list);
+                        ksocknal_data.ksnd_connd_connecting++;
+                       spin_unlock_bh(connd_lock);
+                        dropped_lock = 1;
+
+                        if (ksocknal_connect(route)) {
+                                /* consecutive retry */
+                                if (cons_retry++ > SOCKNAL_INSANITY_RECONN) {
+                                        CWARN("massive consecutive "
+                                             "re-connecting to %pI4h\n",
+                                             &route->ksnr_ipaddr);
+                                        cons_retry = 0;
+                                }
+                        } else {
+                                cons_retry = 0;
+                        }
+
+                        ksocknal_route_decref(route);
+
+                       spin_lock_bh(connd_lock);
+                       ksocknal_data.ksnd_connd_connecting--;
+               }
+
+               if (dropped_lock) {
+                       if (++nloops < SOCKNAL_RESCHED)
+                               continue;
+                       spin_unlock_bh(connd_lock);
+                       nloops = 0;
+                       cond_resched();
+                       spin_lock_bh(connd_lock);
+                       continue;
+               }
+
+               /* Nothing to do for 'timeout'  */
+               set_current_state(TASK_INTERRUPTIBLE);
+               add_wait_queue_exclusive(&ksocknal_data.ksnd_connd_waitq, &wait);
+               spin_unlock_bh(connd_lock);
+
+               nloops = 0;
+               schedule_timeout(timeout);
+
+               set_current_state(TASK_RUNNING);
+               remove_wait_queue(&ksocknal_data.ksnd_connd_waitq, &wait);
+               spin_lock_bh(connd_lock);
+       }
+       ksocknal_data.ksnd_connd_running--;
+       spin_unlock_bh(connd_lock);
+
+       ksocknal_thread_fini();
+       return 0;
 }
 
-ksock_conn_t *
-ksocknal_find_timed_out_conn (ksock_peer_t *peer)
+static struct ksock_conn *
+ksocknal_find_timed_out_conn(struct ksock_peer_ni *peer_ni)
 {
         /* We're called with a shared lock on ksnd_global_lock */
-        ksock_conn_t      *conn;
-        struct list_head  *ctmp;
+       struct ksock_conn *conn;
+       struct list_head *ctmp;
+       struct ksock_tx *tx;
+
+       list_for_each(ctmp, &peer_ni->ksnp_conns) {
+               int error;
 
-        list_for_each (ctmp, &peer->ksnp_conns) {
-                int     error;
-                conn = list_entry (ctmp, ksock_conn_t, ksnc_list);
+               conn = list_entry(ctmp, struct ksock_conn, ksnc_list);
 
                 /* Don't need the {get,put}connsock dance to deref ksnc_sock */
                 LASSERT (!conn->ksnc_closing);
 
-                /* SOCK_ERROR will reset error code of socket in
-                 * some platform (like Darwin8.x) */
-                error = SOCK_ERROR(conn->ksnc_sock);
+               error = conn->ksnc_sock->sk->sk_err;
                 if (error != 0) {
                         ksocknal_conn_addref(conn);
 
                         switch (error) {
                         case ECONNRESET:
-                                CDEBUG(D_NETERROR, "A connection with %s "
-                                       "(%u.%u.%u.%u:%d) was reset; "
-                                       "it may have rebooted.\n",
-                                       libcfs_id2str(peer->ksnp_id),
-                                       HIPQUAD(conn->ksnc_ipaddr),
-                                       conn->ksnc_port);
+                                CNETERR("A connection with %s "
+                                       "(%pI4h:%d) was reset; "
+                                        "it may have rebooted.\n",
+                                        libcfs_id2str(peer_ni->ksnp_id),
+                                       &conn->ksnc_ipaddr,
+                                        conn->ksnc_port);
                                 break;
                         case ETIMEDOUT:
-                                CDEBUG(D_NETERROR, "A connection with %s "
-                                       "(%u.%u.%u.%u:%d) timed out; the "
-                                       "network or node may be down.\n",
-                                       libcfs_id2str(peer->ksnp_id),
-                                       HIPQUAD(conn->ksnc_ipaddr),
-                                       conn->ksnc_port);
+                                CNETERR("A connection with %s "
+                                       "(%pI4h:%d) timed out; the "
+                                        "network or node may be down.\n",
+                                        libcfs_id2str(peer_ni->ksnp_id),
+                                       &conn->ksnc_ipaddr,
+                                        conn->ksnc_port);
                                 break;
                         default:
-                                CDEBUG(D_NETERROR, "An unexpected network error %d "
-                                       "occurred with %s "
-                                       "(%u.%u.%u.%u:%d\n", error,
-                                       libcfs_id2str(peer->ksnp_id),
-                                       HIPQUAD(conn->ksnc_ipaddr),
-                                       conn->ksnc_port);
+                                CNETERR("An unexpected network error %d "
+                                        "occurred with %s "
+                                       "(%pI4h:%d\n", error,
+                                        libcfs_id2str(peer_ni->ksnp_id),
+                                       &conn->ksnc_ipaddr,
+                                        conn->ksnc_port);
                                 break;
                         }
 
@@ -2606,34 +2377,34 @@ ksocknal_find_timed_out_conn (ksock_peer_t *peer)
                 }
 
                 if (conn->ksnc_rx_started &&
-                    cfs_time_aftereq(cfs_time_current(),
-                                     conn->ksnc_rx_deadline)) {
+                   ktime_get_seconds() >= conn->ksnc_rx_deadline) {
                         /* Timed out incomplete incoming message */
                         ksocknal_conn_addref(conn);
-                        CDEBUG(D_NETERROR, "Timeout receiving from %s "
-                               "(%u.%u.%u.%u:%d), state %d wanted %d left %d\n",
-                               libcfs_id2str(peer->ksnp_id),
-                               HIPQUAD(conn->ksnc_ipaddr),
-                               conn->ksnc_port,
-                               conn->ksnc_rx_state,
-                               conn->ksnc_rx_nob_wanted,
-                               conn->ksnc_rx_nob_left);
+                       CNETERR("Timeout receiving from %s (%pI4h:%d), "
+                                "state %d wanted %d left %d\n",
+                                libcfs_id2str(peer_ni->ksnp_id),
+                               &conn->ksnc_ipaddr,
+                                conn->ksnc_port,
+                                conn->ksnc_rx_state,
+                                conn->ksnc_rx_nob_wanted,
+                                conn->ksnc_rx_nob_left);
                         return (conn);
                 }
 
-                if ((!list_empty(&conn->ksnc_tx_queue) ||
-                     SOCK_WMEM_QUEUED(conn->ksnc_sock) != 0) &&
-                    cfs_time_aftereq(cfs_time_current(),
-                                     conn->ksnc_tx_deadline)) {
+               if ((!list_empty(&conn->ksnc_tx_queue) ||
+                    conn->ksnc_sock->sk->sk_wmem_queued != 0) &&
+                   ktime_get_seconds() >= conn->ksnc_tx_deadline) {
                         /* Timed out messages queued for sending or
                          * buffered in the socket's send buffer */
                         ksocknal_conn_addref(conn);
-                        CDEBUG(D_NETERROR, "Timeout sending data to %s "
-                               "(%u.%u.%u.%u:%d) the network or that "
-                               "node may be down.\n",
-                               libcfs_id2str(peer->ksnp_id),
-                               HIPQUAD(conn->ksnc_ipaddr),
-                               conn->ksnc_port);
+                       list_for_each_entry(tx, &conn->ksnc_tx_queue,
+                                           tx_list)
+                               tx->tx_hstatus =
+                                       LNET_MSG_STATUS_LOCAL_TIMEOUT;
+                       CNETERR("Timeout sending data to %s (%pI4h:%d) "
+                                "the network or that node may be down.\n",
+                                libcfs_id2str(peer_ni->ksnp_id),
+                               &conn->ksnc_ipaddr, conn->ksnc_port);
                         return (conn);
                 }
         }
@@ -2641,136 +2412,290 @@ ksocknal_find_timed_out_conn (ksock_peer_t *peer)
         return (NULL);
 }
 
-void
-ksocknal_check_peer_timeouts (int idx)
+static inline void
+ksocknal_flush_stale_txs(struct ksock_peer_ni *peer_ni)
+{
+       struct ksock_tx *tx;
+       LIST_HEAD(stale_txs);
+
+       write_lock_bh(&ksocknal_data.ksnd_global_lock);
+
+       while (!list_empty(&peer_ni->ksnp_tx_queue)) {
+               tx = list_entry(peer_ni->ksnp_tx_queue.next,
+                               struct ksock_tx, tx_list);
+
+               if (ktime_get_seconds() < tx->tx_deadline)
+                       break;
+
+               tx->tx_hstatus = LNET_MSG_STATUS_LOCAL_TIMEOUT;
+
+               list_del(&tx->tx_list);
+               list_add_tail(&tx->tx_list, &stale_txs);
+       }
+
+       write_unlock_bh(&ksocknal_data.ksnd_global_lock);
+
+       ksocknal_txlist_done(peer_ni->ksnp_ni, &stale_txs, -ETIMEDOUT);
+}
+
+static int
+ksocknal_send_keepalive_locked(struct ksock_peer_ni *peer_ni)
+__must_hold(&ksocknal_data.ksnd_global_lock)
+{
+       struct ksock_sched *sched;
+       struct ksock_conn *conn;
+       struct ksock_tx *tx;
+
+       /* last_alive will be updated by create_conn */
+       if (list_empty(&peer_ni->ksnp_conns))
+                return 0;
+
+        if (peer_ni->ksnp_proto != &ksocknal_protocol_v3x)
+                return 0;
+
+        if (*ksocknal_tunables.ksnd_keepalive <= 0 ||
+           ktime_get_seconds() < peer_ni->ksnp_last_alive +
+                                 *ksocknal_tunables.ksnd_keepalive)
+                return 0;
+
+       if (ktime_get_seconds() < peer_ni->ksnp_send_keepalive)
+                return 0;
+
+        /* retry 10 secs later, so we wouldn't put pressure
+         * on this peer_ni if we failed to send keepalive this time */
+       peer_ni->ksnp_send_keepalive = ktime_get_seconds() + 10;
+
+        conn = ksocknal_find_conn_locked(peer_ni, NULL, 1);
+        if (conn != NULL) {
+                sched = conn->ksnc_scheduler;
+
+               spin_lock_bh(&sched->kss_lock);
+               if (!list_empty(&conn->ksnc_tx_queue)) {
+                       spin_unlock_bh(&sched->kss_lock);
+                       /* there is an queued ACK, don't need keepalive */
+                       return 0;
+               }
+
+               spin_unlock_bh(&sched->kss_lock);
+       }
+
+       read_unlock(&ksocknal_data.ksnd_global_lock);
+
+       /* cookie = 1 is reserved for keepalive PING */
+       tx = ksocknal_alloc_tx_noop(1, 1);
+       if (tx == NULL) {
+               read_lock(&ksocknal_data.ksnd_global_lock);
+               return -ENOMEM;
+       }
+
+       if (ksocknal_launch_packet(peer_ni->ksnp_ni, tx, peer_ni->ksnp_id) == 0) {
+               read_lock(&ksocknal_data.ksnd_global_lock);
+               return 1;
+       }
+
+       ksocknal_free_tx(tx);
+       read_lock(&ksocknal_data.ksnd_global_lock);
+
+       return -EIO;
+}
+
+
+static void
+ksocknal_check_peer_timeouts(int idx)
 {
-        struct list_head *peers = &ksocknal_data.ksnd_peers[idx];
-        struct list_head *ptmp;
-        ksock_peer_t     *peer;
-        ksock_conn_t     *conn;
+       struct list_head *peers = &ksocknal_data.ksnd_peers[idx];
+       struct ksock_peer_ni *peer_ni;
+       struct ksock_conn *conn;
+       struct ksock_tx *tx;
 
  again:
         /* NB. We expect to have a look at all the peers and not find any
          * connections to time out, so we just use a shared lock while we
          * take a look... */
-        read_lock (&ksocknal_data.ksnd_global_lock);
+       read_lock(&ksocknal_data.ksnd_global_lock);
+
+       list_for_each_entry(peer_ni, peers, ksnp_list) {
+               struct ksock_tx *tx_stale;
+               time64_t deadline = 0;
+               int resid = 0;
+               int n = 0;
+
+                if (ksocknal_send_keepalive_locked(peer_ni) != 0) {
+                       read_unlock(&ksocknal_data.ksnd_global_lock);
+                        goto again;
+                }
 
-        list_for_each (ptmp, peers) {
-                peer = list_entry (ptmp, ksock_peer_t, ksnp_list);
-                conn = ksocknal_find_timed_out_conn (peer);
+                conn = ksocknal_find_timed_out_conn (peer_ni);
 
                 if (conn != NULL) {
-                        read_unlock (&ksocknal_data.ksnd_global_lock);
+                       read_unlock(&ksocknal_data.ksnd_global_lock);
 
                         ksocknal_close_conn_and_siblings (conn, -ETIMEDOUT);
 
                         /* NB we won't find this one again, but we can't
-                         * just proceed with the next peer, since we dropped
+                         * just proceed with the next peer_ni, since we dropped
                          * ksnd_global_lock and it might be dead already! */
                         ksocknal_conn_decref(conn);
                         goto again;
                 }
+
+                /* we can't process stale txs right here because we're
+                 * holding only shared lock */
+               if (!list_empty(&peer_ni->ksnp_tx_queue)) {
+                       struct ksock_tx *tx;
+
+                       tx = list_entry(peer_ni->ksnp_tx_queue.next,
+                                       struct ksock_tx, tx_list);
+                       if (ktime_get_seconds() >= tx->tx_deadline) {
+                                ksocknal_peer_addref(peer_ni);
+                               read_unlock(&ksocknal_data.ksnd_global_lock);
+
+                                ksocknal_flush_stale_txs(peer_ni);
+
+                                ksocknal_peer_decref(peer_ni);
+                                goto again;
+                        }
+                }
+
+               if (list_empty(&peer_ni->ksnp_zc_req_list))
+                        continue;
+
+               tx_stale = NULL;
+               spin_lock(&peer_ni->ksnp_lock);
+               list_for_each_entry(tx, &peer_ni->ksnp_zc_req_list, tx_zc_list) {
+                       if (ktime_get_seconds() < tx->tx_deadline)
+                                break;
+                        /* ignore the TX if connection is being closed */
+                        if (tx->tx_conn->ksnc_closing)
+                                continue;
+                        n++;
+                       if (tx_stale == NULL)
+                               tx_stale = tx;
+                }
+
+               if (tx_stale == NULL) {
+                       spin_unlock(&peer_ni->ksnp_lock);
+                       continue;
+               }
+
+               deadline = tx_stale->tx_deadline;
+               resid    = tx_stale->tx_resid;
+               conn     = tx_stale->tx_conn;
+               ksocknal_conn_addref(conn);
+
+               spin_unlock(&peer_ni->ksnp_lock);
+               read_unlock(&ksocknal_data.ksnd_global_lock);
+
+               CERROR("Total %d stale ZC_REQs for peer_ni %s detected; the "
+                      "oldest(%p) timed out %lld secs ago, "
+                      "resid: %d, wmem: %d\n",
+                      n, libcfs_nid2str(peer_ni->ksnp_id.nid), tx_stale,
+                      ktime_get_seconds() - deadline,
+                      resid, conn->ksnc_sock->sk->sk_wmem_queued);
+
+                ksocknal_close_conn_and_siblings (conn, -ETIMEDOUT);
+                ksocknal_conn_decref(conn);
+                goto again;
         }
 
-        read_unlock (&ksocknal_data.ksnd_global_lock);
+       read_unlock(&ksocknal_data.ksnd_global_lock);
 }
 
-int
-ksocknal_reaper (void *arg)
+int ksocknal_reaper(void *arg)
 {
-        cfs_waitlink_t     wait;
-        ksock_conn_t      *conn;
-        ksock_sched_t     *sched;
-        struct list_head   enomem_conns;
-        int                nenomem_conns;
-        cfs_duration_t     timeout;
-        int                i;
-        int                peer_index = 0;
-        cfs_time_t         deadline = cfs_time_current();
-
-        cfs_daemonize ("socknal_reaper");
+       wait_queue_entry_t wait;
+       struct ksock_conn *conn;
+       struct ksock_sched *sched;
+       struct list_head enomem_conns;
+       int nenomem_conns;
+       time64_t timeout;
+       int i;
+       int peer_index = 0;
+       time64_t deadline = ktime_get_seconds();
+
         cfs_block_allsigs ();
 
-        CFS_INIT_LIST_HEAD(&enomem_conns);
-        cfs_waitlink_init (&wait);
+       INIT_LIST_HEAD(&enomem_conns);
+       init_waitqueue_entry(&wait, current);
 
-        spin_lock_bh (&ksocknal_data.ksnd_reaper_lock);
+       spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
 
         while (!ksocknal_data.ksnd_shuttingdown) {
+               if (!list_empty(&ksocknal_data.ksnd_deathrow_conns)) {
+                       conn = list_entry(ksocknal_data.ksnd_deathrow_conns.next,
+                                         struct ksock_conn, ksnc_list);
+                       list_del(&conn->ksnc_list);
 
-                if (!list_empty (&ksocknal_data.ksnd_deathrow_conns)) {
-                        conn = list_entry (ksocknal_data.ksnd_deathrow_conns.next,
-                                           ksock_conn_t, ksnc_list);
-                        list_del (&conn->ksnc_list);
-                        
-                        spin_unlock_bh (&ksocknal_data.ksnd_reaper_lock);
+                       spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
 
-                        ksocknal_terminate_conn (conn);
-                        ksocknal_conn_decref(conn);
+                       ksocknal_terminate_conn(conn);
+                       ksocknal_conn_decref(conn);
 
-                        spin_lock_bh (&ksocknal_data.ksnd_reaper_lock);
+                       spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
                         continue;
                 }
 
-                if (!list_empty (&ksocknal_data.ksnd_zombie_conns)) {
-                        conn = list_entry (ksocknal_data.ksnd_zombie_conns.next,
-                                           ksock_conn_t, ksnc_list);
-                        list_del (&conn->ksnc_list);
-                        
-                        spin_unlock_bh (&ksocknal_data.ksnd_reaper_lock);
+               if (!list_empty(&ksocknal_data.ksnd_zombie_conns)) {
+                       conn = list_entry(ksocknal_data.ksnd_zombie_conns.next,
+                                         struct ksock_conn, ksnc_list);
+                       list_del(&conn->ksnc_list);
 
-                        ksocknal_destroy_conn (conn);
+                       spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
 
-                        spin_lock_bh (&ksocknal_data.ksnd_reaper_lock);
+                       ksocknal_destroy_conn(conn);
+
+                       spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
                         continue;
                 }
 
-                if (!list_empty (&ksocknal_data.ksnd_enomem_conns)) {
-                        list_add(&enomem_conns, &ksocknal_data.ksnd_enomem_conns);
-                        list_del_init(&ksocknal_data.ksnd_enomem_conns);
+               if (!list_empty(&ksocknal_data.ksnd_enomem_conns)) {
+                       list_add(&enomem_conns,
+                                     &ksocknal_data.ksnd_enomem_conns);
+                       list_del_init(&ksocknal_data.ksnd_enomem_conns);
                 }
 
-                spin_unlock_bh (&ksocknal_data.ksnd_reaper_lock);
+               spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
 
                 /* reschedule all the connections that stalled with ENOMEM... */
                 nenomem_conns = 0;
-                while (!list_empty (&enomem_conns)) {
-                        conn = list_entry (enomem_conns.next,
-                                           ksock_conn_t, ksnc_tx_list);
-                        list_del (&conn->ksnc_tx_list);
+               while (!list_empty(&enomem_conns)) {
+                       conn = list_entry(enomem_conns.next,
+                                         struct ksock_conn, ksnc_tx_list);
+                       list_del(&conn->ksnc_tx_list);
 
                         sched = conn->ksnc_scheduler;
 
-                        spin_lock_bh (&sched->kss_lock);
+                       spin_lock_bh(&sched->kss_lock);
 
-                        LASSERT (conn->ksnc_tx_scheduled);
-                        conn->ksnc_tx_ready = 1;
-                        list_add_tail(&conn->ksnc_tx_list, &sched->kss_tx_conns);
-                        cfs_waitq_signal (&sched->kss_waitq);
+                       LASSERT(conn->ksnc_tx_scheduled);
+                       conn->ksnc_tx_ready = 1;
+                       list_add_tail(&conn->ksnc_tx_list,
+                                         &sched->kss_tx_conns);
+                       wake_up(&sched->kss_waitq);
 
-                        spin_unlock_bh (&sched->kss_lock);
+                       spin_unlock_bh(&sched->kss_lock);
                         nenomem_conns++;
                 }
 
                 /* careful with the jiffy wrap... */
-                while ((timeout = cfs_time_sub(deadline,
-                                               cfs_time_current())) <= 0) {
+               while ((timeout = deadline - ktime_get_seconds()) <= 0) {
                         const int n = 4;
                         const int p = 1;
                         int       chunk = ksocknal_data.ksnd_peer_hash_size;
+                       unsigned int lnd_timeout;
 
                         /* Time to check for timeouts on a few more peers: I do
-                         * checks every 'p' seconds on a proportion of the peer
+                         * checks every 'p' seconds on a proportion of the peer_ni
                          * table and I need to check every connection 'n' times
                          * within a timeout interval, to ensure I detect a
                          * timeout on any connection within (n+1)/n times the
                          * timeout interval. */
 
-                        if (*ksocknal_tunables.ksnd_timeout > n * p)
-                                chunk = (chunk * n * p) /
-                                        *ksocknal_tunables.ksnd_timeout;
-                        if (chunk == 0)
-                                chunk = 1;
+                       lnd_timeout = lnet_get_lnd_timeout();
+                       if (lnd_timeout > n * p)
+                               chunk = (chunk * n * p) / lnd_timeout;
+                       if (chunk == 0)
+                               chunk = 1;
 
                         for (i = 0; i < chunk; i++) {
                                 ksocknal_check_peer_timeouts (peer_index);
@@ -2778,7 +2703,7 @@ ksocknal_reaper (void *arg)
                                              ksocknal_data.ksnd_peer_hash_size;
                         }
 
-                        deadline = cfs_time_add(deadline, cfs_time_seconds(p));
+                       deadline += p;
                 }
 
                 if (nenomem_conns != 0) {
@@ -2787,25 +2712,25 @@ ksocknal_reaper (void *arg)
                          * if any go back on my enomem list. */
                         timeout = SOCKNAL_ENOMEM_RETRY;
                 }
-                ksocknal_data.ksnd_reaper_waketime =
-                        cfs_time_add(cfs_time_current(), timeout);
+               ksocknal_data.ksnd_reaper_waketime = ktime_get_seconds() +
+                                                    timeout;
 
-                set_current_state (TASK_INTERRUPTIBLE);
-                cfs_waitq_add (&ksocknal_data.ksnd_reaper_waitq, &wait);
+               set_current_state(TASK_INTERRUPTIBLE);
+               add_wait_queue(&ksocknal_data.ksnd_reaper_waitq, &wait);
 
-                if (!ksocknal_data.ksnd_shuttingdown &&
-                    list_empty (&ksocknal_data.ksnd_deathrow_conns) &&
-                    list_empty (&ksocknal_data.ksnd_zombie_conns))
-                        cfs_waitq_timedwait (&wait, CFS_TASK_INTERRUPTIBLE, timeout);
+               if (!ksocknal_data.ksnd_shuttingdown &&
+                   list_empty(&ksocknal_data.ksnd_deathrow_conns) &&
+                   list_empty(&ksocknal_data.ksnd_zombie_conns))
+                       schedule_timeout(cfs_time_seconds(timeout));
 
-                set_current_state (TASK_RUNNING);
-                cfs_waitq_del (&ksocknal_data.ksnd_reaper_waitq, &wait);
+               set_current_state(TASK_RUNNING);
+               remove_wait_queue(&ksocknal_data.ksnd_reaper_waitq, &wait);
 
-                spin_lock_bh (&ksocknal_data.ksnd_reaper_lock);
-        }
+               spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
+       }
 
-        spin_unlock_bh (&ksocknal_data.ksnd_reaper_lock);
+       spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
 
-        ksocknal_thread_fini ();
-        return (0);
+       ksocknal_thread_fini();
+       return 0;
 }