kernel/drivers/staging/lustre/lnet/klnds/socklnd/socklnd_cb.c

   1 /*
   2  * Copyright (c) 2003, 2010, Oracle and/or its affiliates. All rights reserved.
   3  *
   4  * Copyright (c) 2011, 2012, Intel Corporation.
   5  *
   6  *   Author: Zach Brown <zab@zabbo.net>
   7  *   Author: Peter J. Braam <braam@clusterfs.com>
   8  *   Author: Phil Schwan <phil@clusterfs.com>
   9  *   Author: Eric Barton <eric@bartonsoftware.com>
  10  *
  11  *   This file is part of Portals, http://www.sf.net/projects/sandiaportals/
  12  *
  13  *   Portals is free software; you can redistribute it and/or
  14  *   modify it under the terms of version 2 of the GNU General Public
  15  *   License as published by the Free Software Foundation.
  16  *
  17  *   Portals is distributed in the hope that it will be useful,
  18  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  *   GNU General Public License for more details.
  21  *
  22  *   You should have received a copy of the GNU General Public License
  23  *   along with Portals; if not, write to the Free Software
  24  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  25  */
  26
  27 #include "socklnd.h"
  28
  29 ksock_tx_t *
  30 ksocknal_alloc_tx(int type, int size)
  31 {
  32         ksock_tx_t *tx = NULL;
  33
  34         if (type == KSOCK_MSG_NOOP) {
  35                 LASSERT(size == KSOCK_NOOP_TX_SIZE);
  36
  37                 /* searching for a noop tx in free list */
  38                 spin_lock(&ksocknal_data.ksnd_tx_lock);
  39
  40                 if (!list_empty(&ksocknal_data.ksnd_idle_noop_txs)) {
  41                         tx = list_entry(ksocknal_data.ksnd_idle_noop_txs. \
  42                                             next, ksock_tx_t, tx_list);
  43                         LASSERT(tx->tx_desc_size == size);
  44                         list_del(&tx->tx_list);
  45                 }
  46
  47                 spin_unlock(&ksocknal_data.ksnd_tx_lock);
  48         }
  49
  50         if (tx == NULL)
  51                 LIBCFS_ALLOC(tx, size);
  52
  53         if (tx == NULL)
  54                 return NULL;
  55
  56         atomic_set(&tx->tx_refcount, 1);
  57         tx->tx_zc_aborted = 0;
  58         tx->tx_zc_capable = 0;
  59         tx->tx_zc_checked = 0;
  60         tx->tx_desc_size  = size;
  61
  62         atomic_inc(&ksocknal_data.ksnd_nactive_txs);
  63
  64         return tx;
  65 }
  66
  67 ksock_tx_t *
  68 ksocknal_alloc_tx_noop(__u64 cookie, int nonblk)
  69 {
  70         ksock_tx_t *tx;
  71
  72         tx = ksocknal_alloc_tx(KSOCK_MSG_NOOP, KSOCK_NOOP_TX_SIZE);
  73         if (tx == NULL) {
  74                 CERROR("Can't allocate noop tx desc\n");
  75                 return NULL;
  76         }
  77
  78         tx->tx_conn     = NULL;
  79         tx->tx_lnetmsg  = NULL;
  80         tx->tx_kiov     = NULL;
  81         tx->tx_nkiov    = 0;
  82         tx->tx_iov      = tx->tx_frags.virt.iov;
  83         tx->tx_niov     = 1;
  84         tx->tx_nonblk   = nonblk;
  85
  86         socklnd_init_msg(&tx->tx_msg, KSOCK_MSG_NOOP);
  87         tx->tx_msg.ksm_zc_cookies[1] = cookie;
  88
  89         return tx;
  90 }
  91
  92
  93 void
  94 ksocknal_free_tx (ksock_tx_t *tx)
  95 {
  96         atomic_dec(&ksocknal_data.ksnd_nactive_txs);
  97
  98         if (tx->tx_lnetmsg == NULL && tx->tx_desc_size == KSOCK_NOOP_TX_SIZE) {
  99                 /* it's a noop tx */
 100                 spin_lock(&ksocknal_data.ksnd_tx_lock);
 101
 102                 list_add(&tx->tx_list, &ksocknal_data.ksnd_idle_noop_txs);
 103
 104                 spin_unlock(&ksocknal_data.ksnd_tx_lock);
 105         } else {
 106                 LIBCFS_FREE(tx, tx->tx_desc_size);
 107         }
 108 }
 109
 110 static int
 111 ksocknal_send_iov (ksock_conn_t *conn, ksock_tx_t *tx)
 112 {
 113         struct kvec  *iov = tx->tx_iov;
 114         int    nob;
 115         int    rc;
 116
 117         LASSERT (tx->tx_niov > 0);
 118
 119         /* Never touch tx->tx_iov inside ksocknal_lib_send_iov() */
 120         rc = ksocknal_lib_send_iov(conn, tx);
 121
 122         if (rc <= 0)                        /* sent nothing? */
 123                 return rc;
 124
 125         nob = rc;
 126         LASSERT (nob <= tx->tx_resid);
 127         tx->tx_resid -= nob;
 128
 129         /* "consume" iov */
 130         do {
 131                 LASSERT (tx->tx_niov > 0);
 132
 133                 if (nob < (int) iov->iov_len) {
 134                         iov->iov_base = (void *)((char *)iov->iov_base + nob);
 135                         iov->iov_len -= nob;
 136                         return rc;
 137                 }
 138
 139                 nob -= iov->iov_len;
 140                 tx->tx_iov = ++iov;
 141                 tx->tx_niov--;
 142         } while (nob != 0);
 143
 144         return rc;
 145 }
 146
 147 static int
 148 ksocknal_send_kiov (ksock_conn_t *conn, ksock_tx_t *tx)
 149 {
 150         lnet_kiov_t    *kiov = tx->tx_kiov;
 151         int     nob;
 152         int     rc;
 153
 154         LASSERT (tx->tx_niov == 0);
 155         LASSERT (tx->tx_nkiov > 0);
 156
 157         /* Never touch tx->tx_kiov inside ksocknal_lib_send_kiov() */
 158         rc = ksocknal_lib_send_kiov(conn, tx);
 159
 160         if (rc <= 0)                        /* sent nothing? */
 161                 return rc;
 162
 163         nob = rc;
 164         LASSERT (nob <= tx->tx_resid);
 165         tx->tx_resid -= nob;
 166
 167         /* "consume" kiov */
 168         do {
 169                 LASSERT(tx->tx_nkiov > 0);
 170
 171                 if (nob < (int)kiov->kiov_len) {
 172                         kiov->kiov_offset += nob;
 173                         kiov->kiov_len -= nob;
 174                         return rc;
 175                 }
 176
 177                 nob -= (int)kiov->kiov_len;
 178                 tx->tx_kiov = ++kiov;
 179                 tx->tx_nkiov--;
 180         } while (nob != 0);
 181
 182         return rc;
 183 }
 184
 185 static int
 186 ksocknal_transmit (ksock_conn_t *conn, ksock_tx_t *tx)
 187 {
 188         int      rc;
 189         int      bufnob;
 190
 191         if (ksocknal_data.ksnd_stall_tx != 0) {
 192                 set_current_state(TASK_UNINTERRUPTIBLE);
 193                 schedule_timeout(cfs_time_seconds(ksocknal_data.ksnd_stall_tx));
 194         }
 195
 196         LASSERT (tx->tx_resid != 0);
 197
 198         rc = ksocknal_connsock_addref(conn);
 199         if (rc != 0) {
 200                 LASSERT (conn->ksnc_closing);
 201                 return -ESHUTDOWN;
 202         }
 203
 204         do {
 205                 if (ksocknal_data.ksnd_enomem_tx > 0) {
 206                         /* testing... */
 207                         ksocknal_data.ksnd_enomem_tx--;
 208                         rc = -EAGAIN;
 209                 } else if (tx->tx_niov != 0) {
 210                         rc = ksocknal_send_iov (conn, tx);
 211                 } else {
 212                         rc = ksocknal_send_kiov (conn, tx);
 213                 }
 214
 215                 bufnob = conn->ksnc_sock->sk->sk_wmem_queued;
 216                 if (rc > 0)                  /* sent something? */
 217                         conn->ksnc_tx_bufnob += rc; /* account it */
 218
 219                 if (bufnob < conn->ksnc_tx_bufnob) {
 220                         /* allocated send buffer bytes < computed; infer
 221                          * something got ACKed */
 222                         conn->ksnc_tx_deadline =
 223                                 cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
 224                         conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
 225                         conn->ksnc_tx_bufnob = bufnob;
 226                         mb();
 227                 }
 228
 229                 if (rc <= 0) { /* Didn't write anything? */
 230
 231                         if (rc == 0) /* some stacks return 0 instead of -EAGAIN */
 232                                 rc = -EAGAIN;
 233
 234                         /* Check if EAGAIN is due to memory pressure */
 235                         if (rc == -EAGAIN && ksocknal_lib_memory_pressure(conn))
 236                                 rc = -ENOMEM;
 237
 238                         break;
 239                 }
 240
 241                 /* socket's wmem_queued now includes 'rc' bytes */
 242                 atomic_sub (rc, &conn->ksnc_tx_nob);
 243                 rc = 0;
 244
 245         } while (tx->tx_resid != 0);
 246
 247         ksocknal_connsock_decref(conn);
 248         return rc;
 249 }
 250
 251 static int
 252 ksocknal_recv_iov (ksock_conn_t *conn)
 253 {
 254         struct kvec *iov = conn->ksnc_rx_iov;
 255         int     nob;
 256         int     rc;
 257
 258         LASSERT (conn->ksnc_rx_niov > 0);
 259
 260         /* Never touch conn->ksnc_rx_iov or change connection
 261          * status inside ksocknal_lib_recv_iov */
 262         rc = ksocknal_lib_recv_iov(conn);
 263
 264         if (rc <= 0)
 265                 return rc;
 266
 267         /* received something... */
 268         nob = rc;
 269
 270         conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
 271         conn->ksnc_rx_deadline =
 272                 cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
 273         mb();                  /* order with setting rx_started */
 274         conn->ksnc_rx_started = 1;
 275
 276         conn->ksnc_rx_nob_wanted -= nob;
 277         conn->ksnc_rx_nob_left -= nob;
 278
 279         do {
 280                 LASSERT (conn->ksnc_rx_niov > 0);
 281
 282                 if (nob < (int)iov->iov_len) {
 283                         iov->iov_len -= nob;
 284                         iov->iov_base += nob;
 285                         return -EAGAIN;
 286                 }
 287
 288                 nob -= iov->iov_len;
 289                 conn->ksnc_rx_iov = ++iov;
 290                 conn->ksnc_rx_niov--;
 291         } while (nob != 0);
 292
 293         return rc;
 294 }
 295
 296 static int
 297 ksocknal_recv_kiov (ksock_conn_t *conn)
 298 {
 299         lnet_kiov_t   *kiov = conn->ksnc_rx_kiov;
 300         int     nob;
 301         int     rc;
 302         LASSERT (conn->ksnc_rx_nkiov > 0);
 303
 304         /* Never touch conn->ksnc_rx_kiov or change connection
 305          * status inside ksocknal_lib_recv_iov */
 306         rc = ksocknal_lib_recv_kiov(conn);
 307
 308         if (rc <= 0)
 309                 return rc;
 310
 311         /* received something... */
 312         nob = rc;
 313
 314         conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
 315         conn->ksnc_rx_deadline =
 316                 cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
 317         mb();                  /* order with setting rx_started */
 318         conn->ksnc_rx_started = 1;
 319
 320         conn->ksnc_rx_nob_wanted -= nob;
 321         conn->ksnc_rx_nob_left -= nob;
 322
 323         do {
 324                 LASSERT (conn->ksnc_rx_nkiov > 0);
 325
 326                 if (nob < (int) kiov->kiov_len) {
 327                         kiov->kiov_offset += nob;
 328                         kiov->kiov_len -= nob;
 329                         return -EAGAIN;
 330                 }
 331
 332                 nob -= kiov->kiov_len;
 333                 conn->ksnc_rx_kiov = ++kiov;
 334                 conn->ksnc_rx_nkiov--;
 335         } while (nob != 0);
 336
 337         return 1;
 338 }
 339
 340 static int
 341 ksocknal_receive (ksock_conn_t *conn)
 342 {
 343         /* Return 1 on success, 0 on EOF, < 0 on error.
 344          * Caller checks ksnc_rx_nob_wanted to determine
 345          * progress/completion. */
 346         int     rc;
 347
 348         if (ksocknal_data.ksnd_stall_rx != 0) {
 349                 set_current_state(TASK_UNINTERRUPTIBLE);
 350                 schedule_timeout(cfs_time_seconds(ksocknal_data.ksnd_stall_rx));
 351         }
 352
 353         rc = ksocknal_connsock_addref(conn);
 354         if (rc != 0) {
 355                 LASSERT (conn->ksnc_closing);
 356                 return -ESHUTDOWN;
 357         }
 358
 359         for (;;) {
 360                 if (conn->ksnc_rx_niov != 0)
 361                         rc = ksocknal_recv_iov (conn);
 362                 else
 363                         rc = ksocknal_recv_kiov (conn);
 364
 365                 if (rc <= 0) {
 366                         /* error/EOF or partial receive */
 367                         if (rc == -EAGAIN) {
 368                                 rc = 1;
 369                         } else if (rc == 0 && conn->ksnc_rx_started) {
 370                                 /* EOF in the middle of a message */
 371                                 rc = -EPROTO;
 372                         }
 373                         break;
 374                 }
 375
 376                 /* Completed a fragment */
 377
 378                 if (conn->ksnc_rx_nob_wanted == 0) {
 379                         rc = 1;
 380                         break;
 381                 }
 382         }
 383
 384         ksocknal_connsock_decref(conn);
 385         return rc;
 386 }
 387
 388 void
 389 ksocknal_tx_done (lnet_ni_t *ni, ksock_tx_t *tx)
 390 {
 391         lnet_msg_t  *lnetmsg = tx->tx_lnetmsg;
 392         int       rc = (tx->tx_resid == 0 && !tx->tx_zc_aborted) ? 0 : -EIO;
 393
 394         LASSERT(ni != NULL || tx->tx_conn != NULL);
 395
 396         if (tx->tx_conn != NULL)
 397                 ksocknal_conn_decref(tx->tx_conn);
 398
 399         if (ni == NULL && tx->tx_conn != NULL)
 400                 ni = tx->tx_conn->ksnc_peer->ksnp_ni;
 401
 402         ksocknal_free_tx (tx);
 403         if (lnetmsg != NULL) /* KSOCK_MSG_NOOP go without lnetmsg */
 404                 lnet_finalize (ni, lnetmsg, rc);
 405 }
 406
 407 void
 408 ksocknal_txlist_done (lnet_ni_t *ni, struct list_head *txlist, int error)
 409 {
 410         ksock_tx_t *tx;
 411
 412         while (!list_empty (txlist)) {
 413                 tx = list_entry (txlist->next, ksock_tx_t, tx_list);
 414
 415                 if (error && tx->tx_lnetmsg != NULL) {
 416                         CNETERR("Deleting packet type %d len %d %s->%s\n",
 417                                 le32_to_cpu (tx->tx_lnetmsg->msg_hdr.type),
 418                                 le32_to_cpu (tx->tx_lnetmsg->msg_hdr.payload_length),
 419                                 libcfs_nid2str(le64_to_cpu(tx->tx_lnetmsg->msg_hdr.src_nid)),
 420                                 libcfs_nid2str(le64_to_cpu(tx->tx_lnetmsg->msg_hdr.dest_nid)));
 421                 } else if (error) {
 422                         CNETERR("Deleting noop packet\n");
 423                 }
 424
 425                 list_del (&tx->tx_list);
 426
 427                 LASSERT (atomic_read(&tx->tx_refcount) == 1);
 428                 ksocknal_tx_done (ni, tx);
 429         }
 430 }
 431
 432 static void
 433 ksocknal_check_zc_req(ksock_tx_t *tx)
 434 {
 435         ksock_conn_t   *conn = tx->tx_conn;
 436         ksock_peer_t   *peer = conn->ksnc_peer;
 437
 438         /* Set tx_msg.ksm_zc_cookies[0] to a unique non-zero cookie and add tx
 439          * to ksnp_zc_req_list if some fragment of this message should be sent
 440          * zero-copy.  Our peer will send an ACK containing this cookie when
 441          * she has received this message to tell us we can signal completion.
 442          * tx_msg.ksm_zc_cookies[0] remains non-zero while tx is on
 443          * ksnp_zc_req_list. */
 444         LASSERT (tx->tx_msg.ksm_type != KSOCK_MSG_NOOP);
 445         LASSERT (tx->tx_zc_capable);
 446
 447         tx->tx_zc_checked = 1;
 448
 449         if (conn->ksnc_proto == &ksocknal_protocol_v1x ||
 450             !conn->ksnc_zc_capable)
 451                 return;
 452
 453         /* assign cookie and queue tx to pending list, it will be released when
 454          * a matching ack is received. See ksocknal_handle_zcack() */
 455
 456         ksocknal_tx_addref(tx);
 457
 458         spin_lock(&peer->ksnp_lock);
 459
 460         /* ZC_REQ is going to be pinned to the peer */
 461         tx->tx_deadline =
 462                 cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
 463
 464         LASSERT (tx->tx_msg.ksm_zc_cookies[0] == 0);
 465
 466         tx->tx_msg.ksm_zc_cookies[0] = peer->ksnp_zc_next_cookie++;
 467
 468         if (peer->ksnp_zc_next_cookie == 0)
 469                 peer->ksnp_zc_next_cookie = SOCKNAL_KEEPALIVE_PING + 1;
 470
 471         list_add_tail(&tx->tx_zc_list, &peer->ksnp_zc_req_list);
 472
 473         spin_unlock(&peer->ksnp_lock);
 474 }
 475
 476 static void
 477 ksocknal_uncheck_zc_req(ksock_tx_t *tx)
 478 {
 479         ksock_peer_t   *peer = tx->tx_conn->ksnc_peer;
 480
 481         LASSERT(tx->tx_msg.ksm_type != KSOCK_MSG_NOOP);
 482         LASSERT(tx->tx_zc_capable);
 483
 484         tx->tx_zc_checked = 0;
 485
 486         spin_lock(&peer->ksnp_lock);
 487
 488         if (tx->tx_msg.ksm_zc_cookies[0] == 0) {
 489                 /* Not waiting for an ACK */
 490                 spin_unlock(&peer->ksnp_lock);
 491                 return;
 492         }
 493
 494         tx->tx_msg.ksm_zc_cookies[0] = 0;
 495         list_del(&tx->tx_zc_list);
 496
 497         spin_unlock(&peer->ksnp_lock);
 498
 499         ksocknal_tx_decref(tx);
 500 }
 501
 502 static int
 503 ksocknal_process_transmit (ksock_conn_t *conn, ksock_tx_t *tx)
 504 {
 505         int         rc;
 506
 507         if (tx->tx_zc_capable && !tx->tx_zc_checked)
 508                 ksocknal_check_zc_req(tx);
 509
 510         rc = ksocknal_transmit (conn, tx);
 511
 512         CDEBUG (D_NET, "send(%d) %d\n", tx->tx_resid, rc);
 513
 514         if (tx->tx_resid == 0) {
 515                 /* Sent everything OK */
 516                 LASSERT (rc == 0);
 517
 518                 return 0;
 519         }
 520
 521         if (rc == -EAGAIN)
 522                 return rc;
 523
 524         if (rc == -ENOMEM) {
 525                 static int counter;
 526
 527                 counter++;   /* exponential backoff warnings */
 528                 if ((counter & (-counter)) == counter)
 529                         CWARN("%u ENOMEM tx %p (%u allocated)\n",
 530                               counter, conn, atomic_read(&libcfs_kmemory));
 531
 532                 /* Queue on ksnd_enomem_conns for retry after a timeout */
 533                 spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
 534
 535                 /* enomem list takes over scheduler's ref... */
 536                 LASSERT (conn->ksnc_tx_scheduled);
 537                 list_add_tail(&conn->ksnc_tx_list,
 538                                   &ksocknal_data.ksnd_enomem_conns);
 539                 if (!cfs_time_aftereq(cfs_time_add(cfs_time_current(),
 540                                                    SOCKNAL_ENOMEM_RETRY),
 541                                    ksocknal_data.ksnd_reaper_waketime))
 542                         wake_up (&ksocknal_data.ksnd_reaper_waitq);
 543
 544                 spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
 545                 return rc;
 546         }
 547
 548         /* Actual error */
 549         LASSERT (rc < 0);
 550
 551         if (!conn->ksnc_closing) {
 552                 switch (rc) {
 553                 case -ECONNRESET:
 554                         LCONSOLE_WARN("Host %pI4h reset our connection while we were sending data; it may have rebooted.\n",
 555                                       &conn->ksnc_ipaddr);
 556                         break;
 557                 default:
 558                         LCONSOLE_WARN("There was an unexpected network error while writing to %pI4h: %d.\n",
 559                                       &conn->ksnc_ipaddr, rc);
 560                         break;
 561                 }
 562                 CDEBUG(D_NET, "[%p] Error %d on write to %s ip %pI4h:%d\n",
 563                        conn, rc,
 564                        libcfs_id2str(conn->ksnc_peer->ksnp_id),
 565                        &conn->ksnc_ipaddr,
 566                        conn->ksnc_port);
 567         }
 568
 569         if (tx->tx_zc_checked)
 570                 ksocknal_uncheck_zc_req(tx);
 571
 572         /* it's not an error if conn is being closed */
 573         ksocknal_close_conn_and_siblings (conn,
 574                                           (conn->ksnc_closing) ? 0 : rc);
 575
 576         return rc;
 577 }
 578
 579 static void
 580 ksocknal_launch_connection_locked (ksock_route_t *route)
 581 {
 582
 583         /* called holding write lock on ksnd_global_lock */
 584
 585         LASSERT (!route->ksnr_scheduled);
 586         LASSERT (!route->ksnr_connecting);
 587         LASSERT ((ksocknal_route_mask() & ~route->ksnr_connected) != 0);
 588
 589         route->ksnr_scheduled = 1;            /* scheduling conn for connd */
 590         ksocknal_route_addref(route);      /* extra ref for connd */
 591
 592         spin_lock_bh(&ksocknal_data.ksnd_connd_lock);
 593
 594         list_add_tail(&route->ksnr_connd_list,
 595                           &ksocknal_data.ksnd_connd_routes);
 596         wake_up(&ksocknal_data.ksnd_connd_waitq);
 597
 598         spin_unlock_bh(&ksocknal_data.ksnd_connd_lock);
 599 }
 600
 601 void
 602 ksocknal_launch_all_connections_locked (ksock_peer_t *peer)
 603 {
 604         ksock_route_t *route;
 605
 606         /* called holding write lock on ksnd_global_lock */
 607         for (;;) {
 608                 /* launch any/all connections that need it */
 609                 route = ksocknal_find_connectable_route_locked(peer);
 610                 if (route == NULL)
 611                         return;
 612
 613                 ksocknal_launch_connection_locked(route);
 614         }
 615 }
 616
 617 ksock_conn_t *
 618 ksocknal_find_conn_locked(ksock_peer_t *peer, ksock_tx_t *tx, int nonblk)
 619 {
 620         struct list_head       *tmp;
 621         ksock_conn_t     *conn;
 622         ksock_conn_t     *typed = NULL;
 623         ksock_conn_t     *fallback = NULL;
 624         int            tnob     = 0;
 625         int            fnob     = 0;
 626
 627         list_for_each (tmp, &peer->ksnp_conns) {
 628                 ksock_conn_t *c  = list_entry(tmp, ksock_conn_t, ksnc_list);
 629                 int        nob = atomic_read(&c->ksnc_tx_nob) +
 630                                     c->ksnc_sock->sk->sk_wmem_queued;
 631                 int        rc;
 632
 633                 LASSERT (!c->ksnc_closing);
 634                 LASSERT (c->ksnc_proto != NULL &&
 635                          c->ksnc_proto->pro_match_tx != NULL);
 636
 637                 rc = c->ksnc_proto->pro_match_tx(c, tx, nonblk);
 638
 639                 switch (rc) {
 640                 default:
 641                         LBUG();
 642                 case SOCKNAL_MATCH_NO: /* protocol rejected the tx */
 643                         continue;
 644
 645                 case SOCKNAL_MATCH_YES: /* typed connection */
 646                         if (typed == NULL || tnob > nob ||
 647                             (tnob == nob && *ksocknal_tunables.ksnd_round_robin &&
 648                              cfs_time_after(typed->ksnc_tx_last_post, c->ksnc_tx_last_post))) {
 649                                 typed = c;
 650                                 tnob  = nob;
 651                         }
 652                         break;
 653
 654                 case SOCKNAL_MATCH_MAY: /* fallback connection */
 655                         if (fallback == NULL || fnob > nob ||
 656                             (fnob == nob && *ksocknal_tunables.ksnd_round_robin &&
 657                              cfs_time_after(fallback->ksnc_tx_last_post, c->ksnc_tx_last_post))) {
 658                                 fallback = c;
 659                                 fnob     = nob;
 660                         }
 661                         break;
 662                 }
 663         }
 664
 665         /* prefer the typed selection */
 666         conn = (typed != NULL) ? typed : fallback;
 667
 668         if (conn != NULL)
 669                 conn->ksnc_tx_last_post = cfs_time_current();
 670
 671         return conn;
 672 }
 673
 674 void
 675 ksocknal_tx_prep(ksock_conn_t *conn, ksock_tx_t *tx)
 676 {
 677         conn->ksnc_proto->pro_pack(tx);
 678
 679         atomic_add (tx->tx_nob, &conn->ksnc_tx_nob);
 680         ksocknal_conn_addref(conn); /* +1 ref for tx */
 681         tx->tx_conn = conn;
 682 }
 683
 684 void
 685 ksocknal_queue_tx_locked (ksock_tx_t *tx, ksock_conn_t *conn)
 686 {
 687         ksock_sched_t *sched = conn->ksnc_scheduler;
 688         ksock_msg_t   *msg = &tx->tx_msg;
 689         ksock_tx_t    *ztx = NULL;
 690         int         bufnob = 0;
 691
 692         /* called holding global lock (read or irq-write) and caller may
 693          * not have dropped this lock between finding conn and calling me,
 694          * so we don't need the {get,put}connsock dance to deref
 695          * ksnc_sock... */
 696         LASSERT(!conn->ksnc_closing);
 697
 698         CDEBUG(D_NET, "Sending to %s ip %pI4h:%d\n",
 699                 libcfs_id2str(conn->ksnc_peer->ksnp_id),
 700                 &conn->ksnc_ipaddr,
 701                 conn->ksnc_port);
 702
 703         ksocknal_tx_prep(conn, tx);
 704
 705         /* Ensure the frags we've been given EXACTLY match the number of
 706          * bytes we want to send.  Many TCP/IP stacks disregard any total
 707          * size parameters passed to them and just look at the frags.
 708          *
 709          * We always expect at least 1 mapped fragment containing the
 710          * complete ksocknal message header. */
 711         LASSERT (lnet_iov_nob (tx->tx_niov, tx->tx_iov) +
 712                  lnet_kiov_nob(tx->tx_nkiov, tx->tx_kiov) ==
 713                  (unsigned int)tx->tx_nob);
 714         LASSERT (tx->tx_niov >= 1);
 715         LASSERT (tx->tx_resid == tx->tx_nob);
 716
 717         CDEBUG (D_NET, "Packet %p type %d, nob %d niov %d nkiov %d\n",
 718                 tx, (tx->tx_lnetmsg != NULL) ? tx->tx_lnetmsg->msg_hdr.type:
 719                                                KSOCK_MSG_NOOP,
 720                 tx->tx_nob, tx->tx_niov, tx->tx_nkiov);
 721
 722         /*
 723          * FIXME: SOCK_WMEM_QUEUED and SOCK_ERROR could block in __DARWIN8__
 724          * but they're used inside spinlocks a lot.
 725          */
 726         bufnob = conn->ksnc_sock->sk->sk_wmem_queued;
 727         spin_lock_bh(&sched->kss_lock);
 728
 729         if (list_empty(&conn->ksnc_tx_queue) && bufnob == 0) {
 730                 /* First packet starts the timeout */
 731                 conn->ksnc_tx_deadline =
 732                         cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
 733                 if (conn->ksnc_tx_bufnob > 0) /* something got ACKed */
 734                         conn->ksnc_peer->ksnp_last_alive = cfs_time_current();
 735                 conn->ksnc_tx_bufnob = 0;
 736                 mb(); /* order with adding to tx_queue */
 737         }
 738
 739         if (msg->ksm_type == KSOCK_MSG_NOOP) {
 740                 /* The packet is noop ZC ACK, try to piggyback the ack_cookie
 741                  * on a normal packet so I don't need to send it */
 742                 LASSERT (msg->ksm_zc_cookies[1] != 0);
 743                 LASSERT (conn->ksnc_proto->pro_queue_tx_zcack != NULL);
 744
 745                 if (conn->ksnc_proto->pro_queue_tx_zcack(conn, tx, 0))
 746                         ztx = tx; /* ZC ACK piggybacked on ztx release tx later */
 747
 748         } else {
 749                 /* It's a normal packet - can it piggback a noop zc-ack that
 750                  * has been queued already? */
 751                 LASSERT (msg->ksm_zc_cookies[1] == 0);
 752                 LASSERT (conn->ksnc_proto->pro_queue_tx_msg != NULL);
 753
 754                 ztx = conn->ksnc_proto->pro_queue_tx_msg(conn, tx);
 755                 /* ztx will be released later */
 756         }
 757
 758         if (ztx != NULL) {
 759                 atomic_sub (ztx->tx_nob, &conn->ksnc_tx_nob);
 760                 list_add_tail(&ztx->tx_list, &sched->kss_zombie_noop_txs);
 761         }
 762
 763         if (conn->ksnc_tx_ready &&      /* able to send */
 764             !conn->ksnc_tx_scheduled) { /* not scheduled to send */
 765                 /* +1 ref for scheduler */
 766                 ksocknal_conn_addref(conn);
 767                 list_add_tail (&conn->ksnc_tx_list,
 768                                    &sched->kss_tx_conns);
 769                 conn->ksnc_tx_scheduled = 1;
 770                 wake_up (&sched->kss_waitq);
 771         }
 772
 773         spin_unlock_bh(&sched->kss_lock);
 774 }
 775
 776
 777 ksock_route_t *
 778 ksocknal_find_connectable_route_locked (ksock_peer_t *peer)
 779 {
 780         unsigned long     now = cfs_time_current();
 781         struct list_head    *tmp;
 782         ksock_route_t *route;
 783
 784         list_for_each (tmp, &peer->ksnp_routes) {
 785                 route = list_entry (tmp, ksock_route_t, ksnr_list);
 786
 787                 LASSERT (!route->ksnr_connecting || route->ksnr_scheduled);
 788
 789                 if (route->ksnr_scheduled)      /* connections being established */
 790                         continue;
 791
 792                 /* all route types connected ? */
 793                 if ((ksocknal_route_mask() & ~route->ksnr_connected) == 0)
 794                         continue;
 795
 796                 if (!(route->ksnr_retry_interval == 0 || /* first attempt */
 797                       cfs_time_aftereq(now, route->ksnr_timeout))) {
 798                         CDEBUG(D_NET,
 799                                "Too soon to retry route %pI4h (cnted %d, interval %ld, %ld secs later)\n",
 800                                &route->ksnr_ipaddr,
 801                                route->ksnr_connected,
 802                                route->ksnr_retry_interval,
 803                                cfs_duration_sec(route->ksnr_timeout - now));
 804                         continue;
 805                 }
 806
 807                 return route;
 808         }
 809
 810         return NULL;
 811 }
 812
 813 ksock_route_t *
 814 ksocknal_find_connecting_route_locked (ksock_peer_t *peer)
 815 {
 816         struct list_head        *tmp;
 817         ksock_route_t     *route;
 818
 819         list_for_each (tmp, &peer->ksnp_routes) {
 820                 route = list_entry (tmp, ksock_route_t, ksnr_list);
 821
 822                 LASSERT (!route->ksnr_connecting || route->ksnr_scheduled);
 823
 824                 if (route->ksnr_scheduled)
 825                         return route;
 826         }
 827
 828         return NULL;
 829 }
 830
 831 int
 832 ksocknal_launch_packet (lnet_ni_t *ni, ksock_tx_t *tx, lnet_process_id_t id)
 833 {
 834         ksock_peer_t     *peer;
 835         ksock_conn_t     *conn;
 836         rwlock_t     *g_lock;
 837         int            retry;
 838         int            rc;
 839
 840         LASSERT (tx->tx_conn == NULL);
 841
 842         g_lock = &ksocknal_data.ksnd_global_lock;
 843
 844         for (retry = 0;; retry = 1) {
 845                 read_lock(g_lock);
 846                 peer = ksocknal_find_peer_locked(ni, id);
 847                 if (peer != NULL) {
 848                         if (ksocknal_find_connectable_route_locked(peer) == NULL) {
 849                                 conn = ksocknal_find_conn_locked(peer, tx, tx->tx_nonblk);
 850                                 if (conn != NULL) {
 851                                         /* I've got no routes that need to be
 852                                          * connecting and I do have an actual
 853                                          * connection... */
 854                                         ksocknal_queue_tx_locked (tx, conn);
 855                                         read_unlock(g_lock);
 856                                         return 0;
 857                                 }
 858                         }
 859                 }
 860
 861                 /* I'll need a write lock... */
 862                 read_unlock(g_lock);
 863
 864                 write_lock_bh(g_lock);
 865
 866                 peer = ksocknal_find_peer_locked(ni, id);
 867                 if (peer != NULL)
 868                         break;
 869
 870                 write_unlock_bh(g_lock);
 871
 872                 if ((id.pid & LNET_PID_USERFLAG) != 0) {
 873                         CERROR("Refusing to create a connection to userspace process %s\n",
 874                                libcfs_id2str(id));
 875                         return -EHOSTUNREACH;
 876                 }
 877
 878                 if (retry) {
 879                         CERROR("Can't find peer %s\n", libcfs_id2str(id));
 880                         return -EHOSTUNREACH;
 881                 }
 882
 883                 rc = ksocknal_add_peer(ni, id,
 884                                        LNET_NIDADDR(id.nid),
 885                                        lnet_acceptor_port());
 886                 if (rc != 0) {
 887                         CERROR("Can't add peer %s: %d\n",
 888                                libcfs_id2str(id), rc);
 889                         return rc;
 890                 }
 891         }
 892
 893         ksocknal_launch_all_connections_locked(peer);
 894
 895         conn = ksocknal_find_conn_locked(peer, tx, tx->tx_nonblk);
 896         if (conn != NULL) {
 897                 /* Connection exists; queue message on it */
 898                 ksocknal_queue_tx_locked (tx, conn);
 899                 write_unlock_bh(g_lock);
 900                 return 0;
 901         }
 902
 903         if (peer->ksnp_accepting > 0 ||
 904             ksocknal_find_connecting_route_locked (peer) != NULL) {
 905                 /* the message is going to be pinned to the peer */
 906                 tx->tx_deadline =
 907                         cfs_time_shift(*ksocknal_tunables.ksnd_timeout);
 908
 909                 /* Queue the message until a connection is established */
 910                 list_add_tail (&tx->tx_list, &peer->ksnp_tx_queue);
 911                 write_unlock_bh(g_lock);
 912                 return 0;
 913         }
 914
 915         write_unlock_bh(g_lock);
 916
 917         /* NB Routes may be ignored if connections to them failed recently */
 918         CNETERR("No usable routes to %s\n", libcfs_id2str(id));
 919         return -EHOSTUNREACH;
 920 }
 921
 922 int
 923 ksocknal_send(lnet_ni_t *ni, void *private, lnet_msg_t *lntmsg)
 924 {
 925         int            mpflag = 1;
 926         int            type = lntmsg->msg_type;
 927         lnet_process_id_t target = lntmsg->msg_target;
 928         unsigned int      payload_niov = lntmsg->msg_niov;
 929         struct kvec      *payload_iov = lntmsg->msg_iov;
 930         lnet_kiov_t      *payload_kiov = lntmsg->msg_kiov;
 931         unsigned int      payload_offset = lntmsg->msg_offset;
 932         unsigned int      payload_nob = lntmsg->msg_len;
 933         ksock_tx_t       *tx;
 934         int            desc_size;
 935         int            rc;
 936
 937         /* NB 'private' is different depending on what we're sending.
 938          * Just ignore it... */
 939
 940         CDEBUG(D_NET, "sending %u bytes in %d frags to %s\n",
 941                payload_nob, payload_niov, libcfs_id2str(target));
 942
 943         LASSERT (payload_nob == 0 || payload_niov > 0);
 944         LASSERT (payload_niov <= LNET_MAX_IOV);
 945         /* payload is either all vaddrs or all pages */
 946         LASSERT (!(payload_kiov != NULL && payload_iov != NULL));
 947         LASSERT (!in_interrupt ());
 948
 949         if (payload_iov != NULL)
 950                 desc_size = offsetof(ksock_tx_t,
 951                                      tx_frags.virt.iov[1 + payload_niov]);
 952         else
 953                 desc_size = offsetof(ksock_tx_t,
 954                                      tx_frags.paged.kiov[payload_niov]);
 955
 956         if (lntmsg->msg_vmflush)
 957                 mpflag = cfs_memory_pressure_get_and_set();
 958         tx = ksocknal_alloc_tx(KSOCK_MSG_LNET, desc_size);
 959         if (tx == NULL) {
 960                 CERROR("Can't allocate tx desc type %d size %d\n",
 961                        type, desc_size);
 962                 if (lntmsg->msg_vmflush)
 963                         cfs_memory_pressure_restore(mpflag);
 964                 return -ENOMEM;
 965         }
 966
 967         tx->tx_conn = NULL;                  /* set when assigned a conn */
 968         tx->tx_lnetmsg = lntmsg;
 969
 970         if (payload_iov != NULL) {
 971                 tx->tx_kiov = NULL;
 972                 tx->tx_nkiov = 0;
 973                 tx->tx_iov = tx->tx_frags.virt.iov;
 974                 tx->tx_niov = 1 +
 975                               lnet_extract_iov(payload_niov, &tx->tx_iov[1],
 976                                                payload_niov, payload_iov,
 977                                                payload_offset, payload_nob);
 978         } else {
 979                 tx->tx_niov = 1;
 980                 tx->tx_iov = &tx->tx_frags.paged.iov;
 981                 tx->tx_kiov = tx->tx_frags.paged.kiov;
 982                 tx->tx_nkiov = lnet_extract_kiov(payload_niov, tx->tx_kiov,
 983                                                  payload_niov, payload_kiov,
 984                                                  payload_offset, payload_nob);
 985
 986                 if (payload_nob >= *ksocknal_tunables.ksnd_zc_min_payload)
 987                         tx->tx_zc_capable = 1;
 988         }
 989
 990         socklnd_init_msg(&tx->tx_msg, KSOCK_MSG_LNET);
 991
 992         /* The first fragment will be set later in pro_pack */
 993         rc = ksocknal_launch_packet(ni, tx, target);
 994         if (!mpflag)
 995                 cfs_memory_pressure_restore(mpflag);
 996
 997         if (rc == 0)
 998                 return 0;
 999
1000         ksocknal_free_tx(tx);
1001         return -EIO;
1002 }
1003
1004 int
1005 ksocknal_thread_start(int (*fn)(void *arg), void *arg, char *name)
1006 {
1007         struct task_struct *task = kthread_run(fn, arg, "%s", name);
1008
1009         if (IS_ERR(task))
1010                 return PTR_ERR(task);
1011
1012         write_lock_bh(&ksocknal_data.ksnd_global_lock);
1013         ksocknal_data.ksnd_nthreads++;
1014         write_unlock_bh(&ksocknal_data.ksnd_global_lock);
1015         return 0;
1016 }
1017
1018 void
1019 ksocknal_thread_fini (void)
1020 {
1021         write_lock_bh(&ksocknal_data.ksnd_global_lock);
1022         ksocknal_data.ksnd_nthreads--;
1023         write_unlock_bh(&ksocknal_data.ksnd_global_lock);
1024 }
1025
1026 int
1027 ksocknal_new_packet (ksock_conn_t *conn, int nob_to_skip)
1028 {
1029         static char ksocknal_slop_buffer[4096];
1030
1031         int         nob;
1032         unsigned int   niov;
1033         int         skipped;
1034
1035         LASSERT(conn->ksnc_proto != NULL);
1036
1037         if ((*ksocknal_tunables.ksnd_eager_ack & conn->ksnc_type) != 0) {
1038                 /* Remind the socket to ack eagerly... */
1039                 ksocknal_lib_eager_ack(conn);
1040         }
1041
1042         if (nob_to_skip == 0) {  /* right at next packet boundary now */
1043                 conn->ksnc_rx_started = 0;
1044                 mb();                  /* racing with timeout thread */
1045
1046                 switch (conn->ksnc_proto->pro_version) {
1047                 case  KSOCK_PROTO_V2:
1048                 case  KSOCK_PROTO_V3:
1049                         conn->ksnc_rx_state = SOCKNAL_RX_KSM_HEADER;
1050                         conn->ksnc_rx_iov = (struct kvec *)&conn->ksnc_rx_iov_space;
1051                         conn->ksnc_rx_iov[0].iov_base = &conn->ksnc_msg;
1052
1053                         conn->ksnc_rx_nob_wanted = offsetof(ksock_msg_t, ksm_u);
1054                         conn->ksnc_rx_nob_left = offsetof(ksock_msg_t, ksm_u);
1055                         conn->ksnc_rx_iov[0].iov_len  = offsetof(ksock_msg_t, ksm_u);
1056                         break;
1057
1058                 case KSOCK_PROTO_V1:
1059                         /* Receiving bare lnet_hdr_t */
1060                         conn->ksnc_rx_state = SOCKNAL_RX_LNET_HEADER;
1061                         conn->ksnc_rx_nob_wanted = sizeof(lnet_hdr_t);
1062                         conn->ksnc_rx_nob_left = sizeof(lnet_hdr_t);
1063
1064                         conn->ksnc_rx_iov = (struct kvec *)&conn->ksnc_rx_iov_space;
1065                         conn->ksnc_rx_iov[0].iov_base = &conn->ksnc_msg.ksm_u.lnetmsg;
1066                         conn->ksnc_rx_iov[0].iov_len  = sizeof (lnet_hdr_t);
1067                         break;
1068
1069                 default:
1070                         LBUG ();
1071                 }
1072                 conn->ksnc_rx_niov = 1;
1073
1074                 conn->ksnc_rx_kiov = NULL;
1075                 conn->ksnc_rx_nkiov = 0;
1076                 conn->ksnc_rx_csum = ~0;
1077                 return 1;
1078         }
1079
1080         /* Set up to skip as much as possible now.  If there's more left
1081          * (ran out of iov entries) we'll get called again */
1082
1083         conn->ksnc_rx_state = SOCKNAL_RX_SLOP;
1084         conn->ksnc_rx_nob_left = nob_to_skip;
1085         conn->ksnc_rx_iov = (struct kvec *)&conn->ksnc_rx_iov_space;
1086         skipped = 0;
1087         niov = 0;
1088
1089         do {
1090                 nob = min_t(int, nob_to_skip, sizeof(ksocknal_slop_buffer));
1091
1092                 conn->ksnc_rx_iov[niov].iov_base = ksocknal_slop_buffer;
1093                 conn->ksnc_rx_iov[niov].iov_len  = nob;
1094                 niov++;
1095                 skipped += nob;
1096                 nob_to_skip -=nob;
1097
1098         } while (nob_to_skip != 0 &&    /* mustn't overflow conn's rx iov */
1099                  niov < sizeof(conn->ksnc_rx_iov_space) / sizeof (struct iovec));
1100
1101         conn->ksnc_rx_niov = niov;
1102         conn->ksnc_rx_kiov = NULL;
1103         conn->ksnc_rx_nkiov = 0;
1104         conn->ksnc_rx_nob_wanted = skipped;
1105         return 0;
1106 }
1107
1108 static int
1109 ksocknal_process_receive (ksock_conn_t *conn)
1110 {
1111         lnet_hdr_t      *lhdr;
1112         lnet_process_id_t *id;
1113         int             rc;
1114
1115         LASSERT (atomic_read(&conn->ksnc_conn_refcount) > 0);
1116
1117         /* NB: sched lock NOT held */
1118         /* SOCKNAL_RX_LNET_HEADER is here for backward compatibility */
1119         LASSERT (conn->ksnc_rx_state == SOCKNAL_RX_KSM_HEADER ||
1120                  conn->ksnc_rx_state == SOCKNAL_RX_LNET_PAYLOAD ||
1121                  conn->ksnc_rx_state == SOCKNAL_RX_LNET_HEADER ||
1122                  conn->ksnc_rx_state == SOCKNAL_RX_SLOP);
1123  again:
1124         if (conn->ksnc_rx_nob_wanted != 0) {
1125                 rc = ksocknal_receive(conn);
1126
1127                 if (rc <= 0) {
1128                         LASSERT (rc != -EAGAIN);
1129
1130                         if (rc == 0)
1131                                 CDEBUG(D_NET, "[%p] EOF from %s ip %pI4h:%d\n",
1132                                        conn,
1133                                        libcfs_id2str(conn->ksnc_peer->ksnp_id),
1134                                        &conn->ksnc_ipaddr,
1135                                        conn->ksnc_port);
1136                         else if (!conn->ksnc_closing)
1137                                 CERROR("[%p] Error %d on read from %s ip %pI4h:%d\n",
1138                                        conn, rc,
1139                                        libcfs_id2str(conn->ksnc_peer->ksnp_id),
1140                                        &conn->ksnc_ipaddr,
1141                                        conn->ksnc_port);
1142
1143                         /* it's not an error if conn is being closed */
1144                         ksocknal_close_conn_and_siblings (conn,
1145                                                           (conn->ksnc_closing) ? 0 : rc);
1146                         return (rc == 0 ? -ESHUTDOWN : rc);
1147                 }
1148
1149                 if (conn->ksnc_rx_nob_wanted != 0) {
1150                         /* short read */
1151                         return -EAGAIN;
1152                 }
1153         }
1154         switch (conn->ksnc_rx_state) {
1155         case SOCKNAL_RX_KSM_HEADER:
1156                 if (conn->ksnc_flip) {
1157                         __swab32s(&conn->ksnc_msg.ksm_type);
1158                         __swab32s(&conn->ksnc_msg.ksm_csum);
1159                         __swab64s(&conn->ksnc_msg.ksm_zc_cookies[0]);
1160                         __swab64s(&conn->ksnc_msg.ksm_zc_cookies[1]);
1161                 }
1162
1163                 if (conn->ksnc_msg.ksm_type != KSOCK_MSG_NOOP &&
1164                     conn->ksnc_msg.ksm_type != KSOCK_MSG_LNET) {
1165                         CERROR("%s: Unknown message type: %x\n",
1166                                libcfs_id2str(conn->ksnc_peer->ksnp_id),
1167                                conn->ksnc_msg.ksm_type);
1168                         ksocknal_new_packet(conn, 0);
1169                         ksocknal_close_conn_and_siblings(conn, -EPROTO);
1170                         return -EPROTO;
1171                 }
1172
1173                 if (conn->ksnc_msg.ksm_type == KSOCK_MSG_NOOP &&
1174                     conn->ksnc_msg.ksm_csum != 0 &&     /* has checksum */
1175                     conn->ksnc_msg.ksm_csum != conn->ksnc_rx_csum) {
1176                         /* NOOP Checksum error */
1177                         CERROR("%s: Checksum error, wire:0x%08X data:0x%08X\n",
1178                                libcfs_id2str(conn->ksnc_peer->ksnp_id),
1179                                conn->ksnc_msg.ksm_csum, conn->ksnc_rx_csum);
1180                         ksocknal_new_packet(conn, 0);
1181                         ksocknal_close_conn_and_siblings(conn, -EPROTO);
1182                         return -EIO;
1183                 }
1184
1185                 if (conn->ksnc_msg.ksm_zc_cookies[1] != 0) {
1186                         __u64 cookie = 0;
1187
1188                         LASSERT (conn->ksnc_proto != &ksocknal_protocol_v1x);
1189
1190                         if (conn->ksnc_msg.ksm_type == KSOCK_MSG_NOOP)
1191                                 cookie = conn->ksnc_msg.ksm_zc_cookies[0];
1192
1193                         rc = conn->ksnc_proto->pro_handle_zcack(conn, cookie,
1194                                                conn->ksnc_msg.ksm_zc_cookies[1]);
1195
1196                         if (rc != 0) {
1197                                 CERROR("%s: Unknown ZC-ACK cookie: %llu, %llu\n",
1198                                        libcfs_id2str(conn->ksnc_peer->ksnp_id),
1199                                        cookie, conn->ksnc_msg.ksm_zc_cookies[1]);
1200                                 ksocknal_new_packet(conn, 0);
1201                                 ksocknal_close_conn_and_siblings(conn, -EPROTO);
1202                                 return rc;
1203                         }
1204                 }
1205
1206                 if (conn->ksnc_msg.ksm_type == KSOCK_MSG_NOOP) {
1207                         ksocknal_new_packet (conn, 0);
1208                         return 0;       /* NOOP is done and just return */
1209                 }
1210
1211                 conn->ksnc_rx_state = SOCKNAL_RX_LNET_HEADER;
1212                 conn->ksnc_rx_nob_wanted = sizeof(ksock_lnet_msg_t);
1213                 conn->ksnc_rx_nob_left = sizeof(ksock_lnet_msg_t);
1214
1215                 conn->ksnc_rx_iov = (struct kvec *)&conn->ksnc_rx_iov_space;
1216                 conn->ksnc_rx_iov[0].iov_base = &conn->ksnc_msg.ksm_u.lnetmsg;
1217                 conn->ksnc_rx_iov[0].iov_len  = sizeof(ksock_lnet_msg_t);
1218
1219                 conn->ksnc_rx_niov = 1;
1220                 conn->ksnc_rx_kiov = NULL;
1221                 conn->ksnc_rx_nkiov = 0;
1222
1223                 goto again;     /* read lnet header now */
1224
1225         case SOCKNAL_RX_LNET_HEADER:
1226                 /* unpack message header */
1227                 conn->ksnc_proto->pro_unpack(&conn->ksnc_msg);
1228
1229                 if ((conn->ksnc_peer->ksnp_id.pid & LNET_PID_USERFLAG) != 0) {
1230                         /* Userspace peer */
1231                         lhdr = &conn->ksnc_msg.ksm_u.lnetmsg.ksnm_hdr;
1232                         id   = &conn->ksnc_peer->ksnp_id;
1233
1234                         /* Substitute process ID assigned at connection time */
1235                         lhdr->src_pid = cpu_to_le32(id->pid);
1236                         lhdr->src_nid = cpu_to_le64(id->nid);
1237                 }
1238
1239                 conn->ksnc_rx_state = SOCKNAL_RX_PARSE;
1240                 ksocknal_conn_addref(conn);     /* ++ref while parsing */
1241
1242                 rc = lnet_parse(conn->ksnc_peer->ksnp_ni,
1243                                 &conn->ksnc_msg.ksm_u.lnetmsg.ksnm_hdr,
1244                                 conn->ksnc_peer->ksnp_id.nid, conn, 0);
1245                 if (rc < 0) {
1246                         /* I just received garbage: give up on this conn */
1247                         ksocknal_new_packet(conn, 0);
1248                         ksocknal_close_conn_and_siblings (conn, rc);
1249                         ksocknal_conn_decref(conn);
1250                         return -EPROTO;
1251                 }
1252
1253                 /* I'm racing with ksocknal_recv() */
1254                 LASSERT (conn->ksnc_rx_state == SOCKNAL_RX_PARSE ||
1255                          conn->ksnc_rx_state == SOCKNAL_RX_LNET_PAYLOAD);
1256
1257                 if (conn->ksnc_rx_state != SOCKNAL_RX_LNET_PAYLOAD)
1258                         return 0;
1259
1260                 /* ksocknal_recv() got called */
1261                 goto again;
1262
1263         case SOCKNAL_RX_LNET_PAYLOAD:
1264                 /* payload all received */
1265                 rc = 0;
1266
1267                 if (conn->ksnc_rx_nob_left == 0 &&   /* not truncating */
1268                     conn->ksnc_msg.ksm_csum != 0 &&  /* has checksum */
1269                     conn->ksnc_msg.ksm_csum != conn->ksnc_rx_csum) {
1270                         CERROR("%s: Checksum error, wire:0x%08X data:0x%08X\n",
1271                                libcfs_id2str(conn->ksnc_peer->ksnp_id),
1272                                conn->ksnc_msg.ksm_csum, conn->ksnc_rx_csum);
1273                         rc = -EIO;
1274                 }
1275
1276                 if (rc == 0 && conn->ksnc_msg.ksm_zc_cookies[0] != 0) {
1277                         LASSERT(conn->ksnc_proto != &ksocknal_protocol_v1x);
1278
1279                         lhdr = &conn->ksnc_msg.ksm_u.lnetmsg.ksnm_hdr;
1280                         id   = &conn->ksnc_peer->ksnp_id;
1281
1282                         rc = conn->ksnc_proto->pro_handle_zcreq(conn,
1283                                         conn->ksnc_msg.ksm_zc_cookies[0],
1284                                         *ksocknal_tunables.ksnd_nonblk_zcack ||
1285                                         le64_to_cpu(lhdr->src_nid) != id->nid);
1286                 }
1287
1288                 lnet_finalize(conn->ksnc_peer->ksnp_ni, conn->ksnc_cookie, rc);
1289
1290                 if (rc != 0) {
1291                         ksocknal_new_packet(conn, 0);
1292                         ksocknal_close_conn_and_siblings (conn, rc);
1293                         return -EPROTO;
1294                 }
1295                 /* Fall through */
1296
1297         case SOCKNAL_RX_SLOP:
1298                 /* starting new packet? */
1299                 if (ksocknal_new_packet (conn, conn->ksnc_rx_nob_left))
1300                         return 0;       /* come back later */
1301                 goto again;          /* try to finish reading slop now */
1302
1303         default:
1304                 break;
1305         }
1306
1307         /* Not Reached */
1308         LBUG ();
1309         return -EINVAL;                /* keep gcc happy */
1310 }
1311
1312 int
1313 ksocknal_recv (lnet_ni_t *ni, void *private, lnet_msg_t *msg, int delayed,
1314                unsigned int niov, struct kvec *iov, lnet_kiov_t *kiov,
1315                unsigned int offset, unsigned int mlen, unsigned int rlen)
1316 {
1317         ksock_conn_t  *conn = (ksock_conn_t *)private;
1318         ksock_sched_t *sched = conn->ksnc_scheduler;
1319
1320         LASSERT (mlen <= rlen);
1321         LASSERT (niov <= LNET_MAX_IOV);
1322
1323         conn->ksnc_cookie = msg;
1324         conn->ksnc_rx_nob_wanted = mlen;
1325         conn->ksnc_rx_nob_left   = rlen;
1326
1327         if (mlen == 0 || iov != NULL) {
1328                 conn->ksnc_rx_nkiov = 0;
1329                 conn->ksnc_rx_kiov = NULL;
1330                 conn->ksnc_rx_iov = conn->ksnc_rx_iov_space.iov;
1331                 conn->ksnc_rx_niov =
1332                         lnet_extract_iov(LNET_MAX_IOV, conn->ksnc_rx_iov,
1333                                          niov, iov, offset, mlen);
1334         } else {
1335                 conn->ksnc_rx_niov = 0;
1336                 conn->ksnc_rx_iov  = NULL;
1337                 conn->ksnc_rx_kiov = conn->ksnc_rx_iov_space.kiov;
1338                 conn->ksnc_rx_nkiov =
1339                         lnet_extract_kiov(LNET_MAX_IOV, conn->ksnc_rx_kiov,
1340                                           niov, kiov, offset, mlen);
1341         }
1342
1343         LASSERT (mlen ==
1344                  lnet_iov_nob (conn->ksnc_rx_niov, conn->ksnc_rx_iov) +
1345                  lnet_kiov_nob (conn->ksnc_rx_nkiov, conn->ksnc_rx_kiov));
1346
1347         LASSERT (conn->ksnc_rx_scheduled);
1348
1349         spin_lock_bh(&sched->kss_lock);
1350
1351         switch (conn->ksnc_rx_state) {
1352         case SOCKNAL_RX_PARSE_WAIT:
1353                 list_add_tail(&conn->ksnc_rx_list, &sched->kss_rx_conns);
1354                 wake_up (&sched->kss_waitq);
1355                 LASSERT (conn->ksnc_rx_ready);
1356                 break;
1357
1358         case SOCKNAL_RX_PARSE:
1359                 /* scheduler hasn't noticed I'm parsing yet */
1360                 break;
1361         }
1362
1363         conn->ksnc_rx_state = SOCKNAL_RX_LNET_PAYLOAD;
1364
1365         spin_unlock_bh(&sched->kss_lock);
1366         ksocknal_conn_decref(conn);
1367         return 0;
1368 }
1369
1370 static inline int
1371 ksocknal_sched_cansleep(ksock_sched_t *sched)
1372 {
1373         int        rc;
1374
1375         spin_lock_bh(&sched->kss_lock);
1376
1377         rc = !ksocknal_data.ksnd_shuttingdown &&
1378               list_empty(&sched->kss_rx_conns) &&
1379               list_empty(&sched->kss_tx_conns);
1380
1381         spin_unlock_bh(&sched->kss_lock);
1382         return rc;
1383 }
1384
1385 int ksocknal_scheduler(void *arg)
1386 {
1387         struct ksock_sched_info *info;
1388         ksock_sched_t           *sched;
1389         ksock_conn_t            *conn;
1390         ksock_tx_t              *tx;
1391         int                     rc;
1392         int                     nloops = 0;
1393         long                    id = (long)arg;
1394
1395         info = ksocknal_data.ksnd_sched_info[KSOCK_THREAD_CPT(id)];
1396         sched = &info->ksi_scheds[KSOCK_THREAD_SID(id)];
1397
1398         cfs_block_allsigs();
1399
1400         rc = cfs_cpt_bind(lnet_cpt_table(), info->ksi_cpt);
1401         if (rc != 0) {
1402                 CERROR("Can't set CPT affinity to %d: %d\n",
1403                        info->ksi_cpt, rc);
1404         }
1405
1406         spin_lock_bh(&sched->kss_lock);
1407
1408         while (!ksocknal_data.ksnd_shuttingdown) {
1409                 int did_something = 0;
1410
1411                 /* Ensure I progress everything semi-fairly */
1412
1413                 if (!list_empty (&sched->kss_rx_conns)) {
1414                         conn = list_entry(sched->kss_rx_conns.next,
1415                                               ksock_conn_t, ksnc_rx_list);
1416                         list_del(&conn->ksnc_rx_list);
1417
1418                         LASSERT(conn->ksnc_rx_scheduled);
1419                         LASSERT(conn->ksnc_rx_ready);
1420
1421                         /* clear rx_ready in case receive isn't complete.
1422                          * Do it BEFORE we call process_recv, since
1423                          * data_ready can set it any time after we release
1424                          * kss_lock. */
1425                         conn->ksnc_rx_ready = 0;
1426                         spin_unlock_bh(&sched->kss_lock);
1427
1428                         rc = ksocknal_process_receive(conn);
1429
1430                         spin_lock_bh(&sched->kss_lock);
1431
1432                         /* I'm the only one that can clear this flag */
1433                         LASSERT(conn->ksnc_rx_scheduled);
1434
1435                         /* Did process_receive get everything it wanted? */
1436                         if (rc == 0)
1437                                 conn->ksnc_rx_ready = 1;
1438
1439                         if (conn->ksnc_rx_state == SOCKNAL_RX_PARSE) {
1440                                 /* Conn blocked waiting for ksocknal_recv()
1441                                  * I change its state (under lock) to signal
1442                                  * it can be rescheduled */
1443                                 conn->ksnc_rx_state = SOCKNAL_RX_PARSE_WAIT;
1444                         } else if (conn->ksnc_rx_ready) {
1445                                 /* reschedule for rx */
1446                                 list_add_tail (&conn->ksnc_rx_list,
1447                                                    &sched->kss_rx_conns);
1448                         } else {
1449                                 conn->ksnc_rx_scheduled = 0;
1450                                 /* drop my ref */
1451                                 ksocknal_conn_decref(conn);
1452                         }
1453
1454                         did_something = 1;
1455                 }
1456
1457                 if (!list_empty (&sched->kss_tx_conns)) {
1458                         LIST_HEAD    (zlist);
1459
1460                         if (!list_empty(&sched->kss_zombie_noop_txs)) {
1461                                 list_add(&zlist,
1462                                              &sched->kss_zombie_noop_txs);
1463                                 list_del_init(&sched->kss_zombie_noop_txs);
1464                         }
1465
1466                         conn = list_entry(sched->kss_tx_conns.next,
1467                                               ksock_conn_t, ksnc_tx_list);
1468                         list_del (&conn->ksnc_tx_list);
1469
1470                         LASSERT(conn->ksnc_tx_scheduled);
1471                         LASSERT(conn->ksnc_tx_ready);
1472                         LASSERT(!list_empty(&conn->ksnc_tx_queue));
1473
1474                         tx = list_entry(conn->ksnc_tx_queue.next,
1475                                             ksock_tx_t, tx_list);
1476
1477                         if (conn->ksnc_tx_carrier == tx)
1478                                 ksocknal_next_tx_carrier(conn);
1479
1480                         /* dequeue now so empty list => more to send */
1481                         list_del(&tx->tx_list);
1482
1483                         /* Clear tx_ready in case send isn't complete.  Do
1484                          * it BEFORE we call process_transmit, since
1485                          * write_space can set it any time after we release
1486                          * kss_lock. */
1487                         conn->ksnc_tx_ready = 0;
1488                         spin_unlock_bh(&sched->kss_lock);
1489
1490                         if (!list_empty(&zlist)) {
1491                                 /* free zombie noop txs, it's fast because
1492                                  * noop txs are just put in freelist */
1493                                 ksocknal_txlist_done(NULL, &zlist, 0);
1494                         }
1495
1496                         rc = ksocknal_process_transmit(conn, tx);
1497
1498                         if (rc == -ENOMEM || rc == -EAGAIN) {
1499                                 /* Incomplete send: replace tx on HEAD of tx_queue */
1500                                 spin_lock_bh(&sched->kss_lock);
1501                                 list_add(&tx->tx_list,
1502                                              &conn->ksnc_tx_queue);
1503                         } else {
1504                                 /* Complete send; tx -ref */
1505                                 ksocknal_tx_decref(tx);
1506
1507                                 spin_lock_bh(&sched->kss_lock);
1508                                 /* assume space for more */
1509                                 conn->ksnc_tx_ready = 1;
1510                         }
1511
1512                         if (rc == -ENOMEM) {
1513                                 /* Do nothing; after a short timeout, this
1514                                  * conn will be reposted on kss_tx_conns. */
1515                         } else if (conn->ksnc_tx_ready &&
1516                                    !list_empty (&conn->ksnc_tx_queue)) {
1517                                 /* reschedule for tx */
1518                                 list_add_tail (&conn->ksnc_tx_list,
1519                                                    &sched->kss_tx_conns);
1520                         } else {
1521                                 conn->ksnc_tx_scheduled = 0;
1522                                 /* drop my ref */
1523                                 ksocknal_conn_decref(conn);
1524                         }
1525
1526                         did_something = 1;
1527                 }
1528                 if (!did_something ||      /* nothing to do */
1529                     ++nloops == SOCKNAL_RESCHED) { /* hogging CPU? */
1530                         spin_unlock_bh(&sched->kss_lock);
1531
1532                         nloops = 0;
1533
1534                         if (!did_something) {   /* wait for something to do */
1535                                 rc = wait_event_interruptible_exclusive(
1536                                         sched->kss_waitq,
1537                                         !ksocknal_sched_cansleep(sched));
1538                                 LASSERT (rc == 0);
1539                         } else {
1540                                 cond_resched();
1541                         }
1542
1543                         spin_lock_bh(&sched->kss_lock);
1544                 }
1545         }
1546
1547         spin_unlock_bh(&sched->kss_lock);
1548         ksocknal_thread_fini();
1549         return 0;
1550 }
1551
1552 /*
1553  * Add connection to kss_rx_conns of scheduler
1554  * and wakeup the scheduler.
1555  */
1556 void ksocknal_read_callback (ksock_conn_t *conn)
1557 {
1558         ksock_sched_t *sched;
1559
1560         sched = conn->ksnc_scheduler;
1561
1562         spin_lock_bh(&sched->kss_lock);
1563
1564         conn->ksnc_rx_ready = 1;
1565
1566         if (!conn->ksnc_rx_scheduled) {  /* not being progressed */
1567                 list_add_tail(&conn->ksnc_rx_list,
1568                                   &sched->kss_rx_conns);
1569                 conn->ksnc_rx_scheduled = 1;
1570                 /* extra ref for scheduler */
1571                 ksocknal_conn_addref(conn);
1572
1573                 wake_up (&sched->kss_waitq);
1574         }
1575         spin_unlock_bh(&sched->kss_lock);
1576 }
1577
1578 /*
1579  * Add connection to kss_tx_conns of scheduler
1580  * and wakeup the scheduler.
1581  */
1582 void ksocknal_write_callback (ksock_conn_t *conn)
1583 {
1584         ksock_sched_t *sched;
1585
1586         sched = conn->ksnc_scheduler;
1587
1588         spin_lock_bh(&sched->kss_lock);
1589
1590         conn->ksnc_tx_ready = 1;
1591
1592         if (!conn->ksnc_tx_scheduled && /* not being progressed */
1593             !list_empty(&conn->ksnc_tx_queue)) { /* packets to send */
1594                 list_add_tail (&conn->ksnc_tx_list,
1595                                    &sched->kss_tx_conns);
1596                 conn->ksnc_tx_scheduled = 1;
1597                 /* extra ref for scheduler */
1598                 ksocknal_conn_addref(conn);
1599
1600                 wake_up (&sched->kss_waitq);
1601         }
1602
1603         spin_unlock_bh(&sched->kss_lock);
1604 }
1605
1606 static ksock_proto_t *
1607 ksocknal_parse_proto_version (ksock_hello_msg_t *hello)
1608 {
1609         __u32   version = 0;
1610
1611         if (hello->kshm_magic == LNET_PROTO_MAGIC)
1612                 version = hello->kshm_version;
1613         else if (hello->kshm_magic == __swab32(LNET_PROTO_MAGIC))
1614                 version = __swab32(hello->kshm_version);
1615
1616         if (version != 0) {
1617 #if SOCKNAL_VERSION_DEBUG
1618                 if (*ksocknal_tunables.ksnd_protocol == 1)
1619                         return NULL;
1620
1621                 if (*ksocknal_tunables.ksnd_protocol == 2 &&
1622                     version == KSOCK_PROTO_V3)
1623                         return NULL;
1624 #endif
1625                 if (version == KSOCK_PROTO_V2)
1626                         return &ksocknal_protocol_v2x;
1627
1628                 if (version == KSOCK_PROTO_V3)
1629                         return &ksocknal_protocol_v3x;
1630
1631                 return NULL;
1632         }
1633
1634         if (hello->kshm_magic == le32_to_cpu(LNET_PROTO_TCP_MAGIC)) {
1635                 lnet_magicversion_t *hmv = (lnet_magicversion_t *)hello;
1636
1637                 CLASSERT (sizeof (lnet_magicversion_t) ==
1638                           offsetof (ksock_hello_msg_t, kshm_src_nid));
1639
1640                 if (hmv->version_major == cpu_to_le16 (KSOCK_PROTO_V1_MAJOR) &&
1641                     hmv->version_minor == cpu_to_le16 (KSOCK_PROTO_V1_MINOR))
1642                         return &ksocknal_protocol_v1x;
1643         }
1644
1645         return NULL;
1646 }
1647
1648 int
1649 ksocknal_send_hello (lnet_ni_t *ni, ksock_conn_t *conn,
1650                      lnet_nid_t peer_nid, ksock_hello_msg_t *hello)
1651 {
1652         /* CAVEAT EMPTOR: this byte flips 'ipaddrs' */
1653         ksock_net_t      *net = (ksock_net_t *)ni->ni_data;
1654
1655         LASSERT (hello->kshm_nips <= LNET_MAX_INTERFACES);
1656
1657         /* rely on caller to hold a ref on socket so it wouldn't disappear */
1658         LASSERT (conn->ksnc_proto != NULL);
1659
1660         hello->kshm_src_nid      = ni->ni_nid;
1661         hello->kshm_dst_nid      = peer_nid;
1662         hello->kshm_src_pid      = the_lnet.ln_pid;
1663
1664         hello->kshm_src_incarnation = net->ksnn_incarnation;
1665         hello->kshm_ctype          = conn->ksnc_type;
1666
1667         return conn->ksnc_proto->pro_send_hello(conn, hello);
1668 }
1669
1670 static int
1671 ksocknal_invert_type(int type)
1672 {
1673         switch (type) {
1674         case SOCKLND_CONN_ANY:
1675         case SOCKLND_CONN_CONTROL:
1676                 return type;
1677         case SOCKLND_CONN_BULK_IN:
1678                 return SOCKLND_CONN_BULK_OUT;
1679         case SOCKLND_CONN_BULK_OUT:
1680                 return SOCKLND_CONN_BULK_IN;
1681         default:
1682                 return SOCKLND_CONN_NONE;
1683         }
1684 }
1685
1686 int
1687 ksocknal_recv_hello (lnet_ni_t *ni, ksock_conn_t *conn,
1688                      ksock_hello_msg_t *hello, lnet_process_id_t *peerid,
1689                      __u64 *incarnation)
1690 {
1691         /* Return < 0   fatal error
1692          *      0         success
1693          *      EALREADY   lost connection race
1694          *      EPROTO     protocol version mismatch
1695          */
1696         struct socket   *sock = conn->ksnc_sock;
1697         int               active = (conn->ksnc_proto != NULL);
1698         int               timeout;
1699         int               proto_match;
1700         int               rc;
1701         ksock_proto_t       *proto;
1702         lnet_process_id_t    recv_id;
1703
1704         /* socket type set on active connections - not set on passive */
1705         LASSERT (!active == !(conn->ksnc_type != SOCKLND_CONN_NONE));
1706
1707         timeout = active ? *ksocknal_tunables.ksnd_timeout :
1708                             lnet_acceptor_timeout();
1709
1710         rc = libcfs_sock_read(sock, &hello->kshm_magic, sizeof (hello->kshm_magic), timeout);
1711         if (rc != 0) {
1712                 CERROR("Error %d reading HELLO from %pI4h\n",
1713                         rc, &conn->ksnc_ipaddr);
1714                 LASSERT (rc < 0);
1715                 return rc;
1716         }
1717
1718         if (hello->kshm_magic != LNET_PROTO_MAGIC &&
1719             hello->kshm_magic != __swab32(LNET_PROTO_MAGIC) &&
1720             hello->kshm_magic != le32_to_cpu (LNET_PROTO_TCP_MAGIC)) {
1721                 /* Unexpected magic! */
1722                 CERROR("Bad magic(1) %#08x (%#08x expected) from %pI4h\n",
1723                        __cpu_to_le32 (hello->kshm_magic),
1724                        LNET_PROTO_TCP_MAGIC,
1725                        &conn->ksnc_ipaddr);
1726                 return -EPROTO;
1727         }
1728
1729         rc = libcfs_sock_read(sock, &hello->kshm_version,
1730                               sizeof(hello->kshm_version), timeout);
1731         if (rc != 0) {
1732                 CERROR("Error %d reading HELLO from %pI4h\n",
1733                         rc, &conn->ksnc_ipaddr);
1734                 LASSERT (rc < 0);
1735                 return rc;
1736         }
1737
1738         proto = ksocknal_parse_proto_version(hello);
1739         if (proto == NULL) {
1740                 if (!active) {
1741                         /* unknown protocol from peer, tell peer my protocol */
1742                         conn->ksnc_proto = &ksocknal_protocol_v3x;
1743 #if SOCKNAL_VERSION_DEBUG
1744                         if (*ksocknal_tunables.ksnd_protocol == 2)
1745                                 conn->ksnc_proto = &ksocknal_protocol_v2x;
1746                         else if (*ksocknal_tunables.ksnd_protocol == 1)
1747                                 conn->ksnc_proto = &ksocknal_protocol_v1x;
1748 #endif
1749                         hello->kshm_nips = 0;
1750                         ksocknal_send_hello(ni, conn, ni->ni_nid, hello);
1751                 }
1752
1753                 CERROR("Unknown protocol version (%d.x expected) from %pI4h\n",
1754                        conn->ksnc_proto->pro_version,
1755                        &conn->ksnc_ipaddr);
1756
1757                 return -EPROTO;
1758         }
1759
1760         proto_match = (conn->ksnc_proto == proto);
1761         conn->ksnc_proto = proto;
1762
1763         /* receive the rest of hello message anyway */
1764         rc = conn->ksnc_proto->pro_recv_hello(conn, hello, timeout);
1765         if (rc != 0) {
1766                 CERROR("Error %d reading or checking hello from from %pI4h\n",
1767                        rc, &conn->ksnc_ipaddr);
1768                 LASSERT (rc < 0);
1769                 return rc;
1770         }
1771
1772         *incarnation = hello->kshm_src_incarnation;
1773
1774         if (hello->kshm_src_nid == LNET_NID_ANY) {
1775                 CERROR("Expecting a HELLO hdr with a NID, but got LNET_NID_ANY from %pI4h\n",
1776                        &conn->ksnc_ipaddr);
1777                 return -EPROTO;
1778         }
1779
1780         if (!active &&
1781             conn->ksnc_port > LNET_ACCEPTOR_MAX_RESERVED_PORT) {
1782                 /* Userspace NAL assigns peer process ID from socket */
1783                 recv_id.pid = conn->ksnc_port | LNET_PID_USERFLAG;
1784                 recv_id.nid = LNET_MKNID(LNET_NIDNET(ni->ni_nid), conn->ksnc_ipaddr);
1785         } else {
1786                 recv_id.nid = hello->kshm_src_nid;
1787                 recv_id.pid = hello->kshm_src_pid;
1788         }
1789
1790         if (!active) {
1791                 *peerid = recv_id;
1792
1793                 /* peer determines type */
1794                 conn->ksnc_type = ksocknal_invert_type(hello->kshm_ctype);
1795                 if (conn->ksnc_type == SOCKLND_CONN_NONE) {
1796                         CERROR("Unexpected type %d from %s ip %pI4h\n",
1797                                 hello->kshm_ctype, libcfs_id2str(*peerid),
1798                                 &conn->ksnc_ipaddr);
1799                         return -EPROTO;
1800                 }
1801
1802                 return 0;
1803         }
1804
1805         if (peerid->pid != recv_id.pid ||
1806             peerid->nid != recv_id.nid) {
1807                 LCONSOLE_ERROR_MSG(0x130, "Connected successfully to %s on host %pI4h, but they claimed they were %s; please check your Lustre configuration.\n",
1808                                    libcfs_id2str(*peerid),
1809                                    &conn->ksnc_ipaddr,
1810                                    libcfs_id2str(recv_id));
1811                 return -EPROTO;
1812         }
1813
1814         if (hello->kshm_ctype == SOCKLND_CONN_NONE) {
1815                 /* Possible protocol mismatch or I lost the connection race */
1816                 return proto_match ? EALREADY : EPROTO;
1817         }
1818
1819         if (ksocknal_invert_type(hello->kshm_ctype) != conn->ksnc_type) {
1820                 CERROR("Mismatched types: me %d, %s ip %pI4h %d\n",
1821                         conn->ksnc_type, libcfs_id2str(*peerid),
1822                         &conn->ksnc_ipaddr,
1823                         hello->kshm_ctype);
1824                 return -EPROTO;
1825         }
1826
1827         return 0;
1828 }
1829
1830 static int
1831 ksocknal_connect (ksock_route_t *route)
1832 {
1833         LIST_HEAD    (zombies);
1834         ksock_peer_t     *peer = route->ksnr_peer;
1835         int            type;
1836         int            wanted;
1837         struct socket     *sock;
1838         unsigned long   deadline;
1839         int            retry_later = 0;
1840         int            rc = 0;
1841
1842         deadline = cfs_time_add(cfs_time_current(),
1843                                 cfs_time_seconds(*ksocknal_tunables.ksnd_timeout));
1844
1845         write_lock_bh(&ksocknal_data.ksnd_global_lock);
1846
1847         LASSERT (route->ksnr_scheduled);
1848         LASSERT (!route->ksnr_connecting);
1849
1850         route->ksnr_connecting = 1;
1851
1852         for (;;) {
1853                 wanted = ksocknal_route_mask() & ~route->ksnr_connected;
1854
1855                 /* stop connecting if peer/route got closed under me, or
1856                  * route got connected while queued */
1857                 if (peer->ksnp_closing || route->ksnr_deleted ||
1858                     wanted == 0) {
1859                         retry_later = 0;
1860                         break;
1861                 }
1862
1863                 /* reschedule if peer is connecting to me */
1864                 if (peer->ksnp_accepting > 0) {
1865                         CDEBUG(D_NET,
1866                                "peer %s(%d) already connecting to me, retry later.\n",
1867                                libcfs_nid2str(peer->ksnp_id.nid), peer->ksnp_accepting);
1868                         retry_later = 1;
1869                 }
1870
1871                 if (retry_later) /* needs reschedule */
1872                         break;
1873
1874                 if ((wanted & (1 << SOCKLND_CONN_ANY)) != 0) {
1875                         type = SOCKLND_CONN_ANY;
1876                 } else if ((wanted & (1 << SOCKLND_CONN_CONTROL)) != 0) {
1877                         type = SOCKLND_CONN_CONTROL;
1878                 } else if ((wanted & (1 << SOCKLND_CONN_BULK_IN)) != 0) {
1879                         type = SOCKLND_CONN_BULK_IN;
1880                 } else {
1881                         LASSERT ((wanted & (1 << SOCKLND_CONN_BULK_OUT)) != 0);
1882                         type = SOCKLND_CONN_BULK_OUT;
1883                 }
1884
1885                 write_unlock_bh(&ksocknal_data.ksnd_global_lock);
1886
1887                 if (cfs_time_aftereq(cfs_time_current(), deadline)) {
1888                         rc = -ETIMEDOUT;
1889                         lnet_connect_console_error(rc, peer->ksnp_id.nid,
1890                                                    route->ksnr_ipaddr,
1891                                                    route->ksnr_port);
1892                         goto failed;
1893                 }
1894
1895                 rc = lnet_connect(&sock, peer->ksnp_id.nid,
1896                                   route->ksnr_myipaddr,
1897                                   route->ksnr_ipaddr, route->ksnr_port);
1898                 if (rc != 0)
1899                         goto failed;
1900
1901                 rc = ksocknal_create_conn(peer->ksnp_ni, route, sock, type);
1902                 if (rc < 0) {
1903                         lnet_connect_console_error(rc, peer->ksnp_id.nid,
1904                                                    route->ksnr_ipaddr,
1905                                                    route->ksnr_port);
1906                         goto failed;
1907                 }
1908
1909                 /* A +ve RC means I have to retry because I lost the connection
1910                  * race or I have to renegotiate protocol version */
1911                 retry_later = (rc != 0);
1912                 if (retry_later)
1913                         CDEBUG(D_NET, "peer %s: conn race, retry later.\n",
1914                                libcfs_nid2str(peer->ksnp_id.nid));
1915
1916                 write_lock_bh(&ksocknal_data.ksnd_global_lock);
1917         }
1918
1919         route->ksnr_scheduled = 0;
1920         route->ksnr_connecting = 0;
1921
1922         if (retry_later) {
1923                 /* re-queue for attention; this frees me up to handle
1924                  * the peer's incoming connection request */
1925
1926                 if (rc == EALREADY ||
1927                     (rc == 0 && peer->ksnp_accepting > 0)) {
1928                         /* We want to introduce a delay before next
1929                          * attempt to connect if we lost conn race,
1930                          * but the race is resolved quickly usually,
1931                          * so min_reconnectms should be good heuristic */
1932                         route->ksnr_retry_interval =
1933                                 cfs_time_seconds(*ksocknal_tunables.ksnd_min_reconnectms)/1000;
1934                         route->ksnr_timeout = cfs_time_add(cfs_time_current(),
1935                                                            route->ksnr_retry_interval);
1936                 }
1937
1938                 ksocknal_launch_connection_locked(route);
1939         }
1940
1941         write_unlock_bh(&ksocknal_data.ksnd_global_lock);
1942         return retry_later;
1943
1944  failed:
1945         write_lock_bh(&ksocknal_data.ksnd_global_lock);
1946
1947         route->ksnr_scheduled = 0;
1948         route->ksnr_connecting = 0;
1949
1950         /* This is a retry rather than a new connection */
1951         route->ksnr_retry_interval *= 2;
1952         route->ksnr_retry_interval =
1953                 max(route->ksnr_retry_interval,
1954                     cfs_time_seconds(*ksocknal_tunables.ksnd_min_reconnectms)/1000);
1955         route->ksnr_retry_interval =
1956                 min(route->ksnr_retry_interval,
1957                     cfs_time_seconds(*ksocknal_tunables.ksnd_max_reconnectms)/1000);
1958
1959         LASSERT (route->ksnr_retry_interval != 0);
1960         route->ksnr_timeout = cfs_time_add(cfs_time_current(),
1961                                            route->ksnr_retry_interval);
1962
1963         if (!list_empty(&peer->ksnp_tx_queue) &&
1964             peer->ksnp_accepting == 0 &&
1965             ksocknal_find_connecting_route_locked(peer) == NULL) {
1966                 ksock_conn_t *conn;
1967
1968                 /* ksnp_tx_queue is queued on a conn on successful
1969                  * connection for V1.x and V2.x */
1970                 if (!list_empty (&peer->ksnp_conns)) {
1971                         conn = list_entry(peer->ksnp_conns.next,
1972                                               ksock_conn_t, ksnc_list);
1973                         LASSERT (conn->ksnc_proto == &ksocknal_protocol_v3x);
1974                 }
1975
1976                 /* take all the blocked packets while I've got the lock and
1977                  * complete below... */
1978                 list_splice_init(&peer->ksnp_tx_queue, &zombies);
1979         }
1980
1981 #if 0      /* irrelevant with only eager routes */
1982         if (!route->ksnr_deleted) {
1983                 /* make this route least-favourite for re-selection */
1984                 list_del(&route->ksnr_list);
1985                 list_add_tail(&route->ksnr_list, &peer->ksnp_routes);
1986         }
1987 #endif
1988         write_unlock_bh(&ksocknal_data.ksnd_global_lock);
1989
1990         ksocknal_peer_failed(peer);
1991         ksocknal_txlist_done(peer->ksnp_ni, &zombies, 1);
1992         return 0;
1993 }
1994
1995 /*
1996  * check whether we need to create more connds.
1997  * It will try to create new thread if it's necessary, @timeout can
1998  * be updated if failed to create, so caller wouldn't keep try while
1999  * running out of resource.
2000  */
2001 static int
2002 ksocknal_connd_check_start(long sec, long *timeout)
2003 {
2004         char name[16];
2005         int rc;
2006         int total = ksocknal_data.ksnd_connd_starting +
2007                     ksocknal_data.ksnd_connd_running;
2008
2009         if (unlikely(ksocknal_data.ksnd_init < SOCKNAL_INIT_ALL)) {
2010                 /* still in initializing */
2011                 return 0;
2012         }
2013
2014         if (total >= *ksocknal_tunables.ksnd_nconnds_max ||
2015             total > ksocknal_data.ksnd_connd_connecting + SOCKNAL_CONND_RESV) {
2016                 /* can't create more connd, or still have enough
2017                  * threads to handle more connecting */
2018                 return 0;
2019         }
2020
2021         if (list_empty(&ksocknal_data.ksnd_connd_routes)) {
2022                 /* no pending connecting request */
2023                 return 0;
2024         }
2025
2026         if (sec - ksocknal_data.ksnd_connd_failed_stamp <= 1) {
2027                 /* may run out of resource, retry later */
2028                 *timeout = cfs_time_seconds(1);
2029                 return 0;
2030         }
2031
2032         if (ksocknal_data.ksnd_connd_starting > 0) {
2033                 /* serialize starting to avoid flood */
2034                 return 0;
2035         }
2036
2037         ksocknal_data.ksnd_connd_starting_stamp = sec;
2038         ksocknal_data.ksnd_connd_starting++;
2039         spin_unlock_bh(&ksocknal_data.ksnd_connd_lock);
2040
2041         /* NB: total is the next id */
2042         snprintf(name, sizeof(name), "socknal_cd%02d", total);
2043         rc = ksocknal_thread_start(ksocknal_connd, NULL, name);
2044
2045         spin_lock_bh(&ksocknal_data.ksnd_connd_lock);
2046         if (rc == 0)
2047                 return 1;
2048
2049         /* we tried ... */
2050         LASSERT(ksocknal_data.ksnd_connd_starting > 0);
2051         ksocknal_data.ksnd_connd_starting--;
2052         ksocknal_data.ksnd_connd_failed_stamp = get_seconds();
2053
2054         return 1;
2055 }
2056
2057 /*
2058  * check whether current thread can exit, it will return 1 if there are too
2059  * many threads and no creating in past 120 seconds.
2060  * Also, this function may update @timeout to make caller come back
2061  * again to recheck these conditions.
2062  */
2063 static int
2064 ksocknal_connd_check_stop(long sec, long *timeout)
2065 {
2066         int val;
2067
2068         if (unlikely(ksocknal_data.ksnd_init < SOCKNAL_INIT_ALL)) {
2069                 /* still in initializing */
2070                 return 0;
2071         }
2072
2073         if (ksocknal_data.ksnd_connd_starting > 0) {
2074                 /* in progress of starting new thread */
2075                 return 0;
2076         }
2077
2078         if (ksocknal_data.ksnd_connd_running <=
2079             *ksocknal_tunables.ksnd_nconnds) { /* can't shrink */
2080                 return 0;
2081         }
2082
2083         /* created thread in past 120 seconds? */
2084         val = (int)(ksocknal_data.ksnd_connd_starting_stamp +
2085                     SOCKNAL_CONND_TIMEOUT - sec);
2086
2087         *timeout = (val > 0) ? cfs_time_seconds(val) :
2088                                cfs_time_seconds(SOCKNAL_CONND_TIMEOUT);
2089         if (val > 0)
2090                 return 0;
2091
2092         /* no creating in past 120 seconds */
2093
2094         return ksocknal_data.ksnd_connd_running >
2095                ksocknal_data.ksnd_connd_connecting + SOCKNAL_CONND_RESV;
2096 }
2097
2098 /* Go through connd_routes queue looking for a route that we can process
2099  * right now, @timeout_p can be updated if we need to come back later */
2100 static ksock_route_t *
2101 ksocknal_connd_get_route_locked(signed long *timeout_p)
2102 {
2103         ksock_route_t *route;
2104         unsigned long     now;
2105
2106         now = cfs_time_current();
2107
2108         /* connd_routes can contain both pending and ordinary routes */
2109         list_for_each_entry (route, &ksocknal_data.ksnd_connd_routes,
2110                                  ksnr_connd_list) {
2111
2112                 if (route->ksnr_retry_interval == 0 ||
2113                     cfs_time_aftereq(now, route->ksnr_timeout))
2114                         return route;
2115
2116                 if (*timeout_p == MAX_SCHEDULE_TIMEOUT ||
2117                     (int)*timeout_p > (int)(route->ksnr_timeout - now))
2118                         *timeout_p = (int)(route->ksnr_timeout - now);
2119         }
2120
2121         return NULL;
2122 }
2123
2124 int
2125 ksocknal_connd (void *arg)
2126 {
2127         spinlock_t    *connd_lock = &ksocknal_data.ksnd_connd_lock;
2128         ksock_connreq_t   *cr;
2129         wait_queue_t     wait;
2130         int             nloops = 0;
2131         int             cons_retry = 0;
2132
2133         cfs_block_allsigs ();
2134
2135         init_waitqueue_entry(&wait, current);
2136
2137         spin_lock_bh(connd_lock);
2138
2139         LASSERT(ksocknal_data.ksnd_connd_starting > 0);
2140         ksocknal_data.ksnd_connd_starting--;
2141         ksocknal_data.ksnd_connd_running++;
2142
2143         while (!ksocknal_data.ksnd_shuttingdown) {
2144                 ksock_route_t *route = NULL;
2145                 long sec = get_seconds();
2146                 long timeout = MAX_SCHEDULE_TIMEOUT;
2147                 int  dropped_lock = 0;
2148
2149                 if (ksocknal_connd_check_stop(sec, &timeout)) {
2150                         /* wakeup another one to check stop */
2151                         wake_up(&ksocknal_data.ksnd_connd_waitq);
2152                         break;
2153                 }
2154
2155                 if (ksocknal_connd_check_start(sec, &timeout)) {
2156                         /* created new thread */
2157                         dropped_lock = 1;
2158                 }
2159
2160                 if (!list_empty(&ksocknal_data.ksnd_connd_connreqs)) {
2161                         /* Connection accepted by the listener */
2162                         cr = list_entry(ksocknal_data.ksnd_connd_connreqs. \
2163                                             next, ksock_connreq_t, ksncr_list);
2164
2165                         list_del(&cr->ksncr_list);
2166                         spin_unlock_bh(connd_lock);
2167                         dropped_lock = 1;
2168
2169                         ksocknal_create_conn(cr->ksncr_ni, NULL,
2170                                              cr->ksncr_sock, SOCKLND_CONN_NONE);
2171                         lnet_ni_decref(cr->ksncr_ni);
2172                         LIBCFS_FREE(cr, sizeof(*cr));
2173
2174                         spin_lock_bh(connd_lock);
2175                 }
2176
2177                 /* Only handle an outgoing connection request if there
2178                  * is a thread left to handle incoming connections and
2179                  * create new connd */
2180                 if (ksocknal_data.ksnd_connd_connecting + SOCKNAL_CONND_RESV <
2181                     ksocknal_data.ksnd_connd_running) {
2182                         route = ksocknal_connd_get_route_locked(&timeout);
2183                 }
2184                 if (route != NULL) {
2185                         list_del (&route->ksnr_connd_list);
2186                         ksocknal_data.ksnd_connd_connecting++;
2187                         spin_unlock_bh(connd_lock);
2188                         dropped_lock = 1;
2189
2190                         if (ksocknal_connect(route)) {
2191                                 /* consecutive retry */
2192                                 if (cons_retry++ > SOCKNAL_INSANITY_RECONN) {
2193                                         CWARN("massive consecutive re-connecting to %pI4h\n",
2194                                               &route->ksnr_ipaddr);
2195                                         cons_retry = 0;
2196                                 }
2197                         } else {
2198                                 cons_retry = 0;
2199                         }
2200
2201                         ksocknal_route_decref(route);
2202
2203                         spin_lock_bh(connd_lock);
2204                         ksocknal_data.ksnd_connd_connecting--;
2205                 }
2206
2207                 if (dropped_lock) {
2208                         if (++nloops < SOCKNAL_RESCHED)
2209                                 continue;
2210                         spin_unlock_bh(connd_lock);
2211                         nloops = 0;
2212                         cond_resched();
2213                         spin_lock_bh(connd_lock);
2214                         continue;
2215                 }
2216
2217                 /* Nothing to do for 'timeout'  */
2218                 set_current_state(TASK_INTERRUPTIBLE);
2219                 add_wait_queue_exclusive(&ksocknal_data.ksnd_connd_waitq, &wait);
2220                 spin_unlock_bh(connd_lock);
2221
2222                 nloops = 0;
2223                 schedule_timeout(timeout);
2224
2225                 remove_wait_queue(&ksocknal_data.ksnd_connd_waitq, &wait);
2226                 spin_lock_bh(connd_lock);
2227         }
2228         ksocknal_data.ksnd_connd_running--;
2229         spin_unlock_bh(connd_lock);
2230
2231         ksocknal_thread_fini();
2232         return 0;
2233 }
2234
2235 static ksock_conn_t *
2236 ksocknal_find_timed_out_conn (ksock_peer_t *peer)
2237 {
2238         /* We're called with a shared lock on ksnd_global_lock */
2239         ksock_conn_t      *conn;
2240         struct list_head        *ctmp;
2241
2242         list_for_each (ctmp, &peer->ksnp_conns) {
2243                 int     error;
2244                 conn = list_entry (ctmp, ksock_conn_t, ksnc_list);
2245
2246                 /* Don't need the {get,put}connsock dance to deref ksnc_sock */
2247                 LASSERT (!conn->ksnc_closing);
2248
2249                 /* SOCK_ERROR will reset error code of socket in
2250                  * some platform (like Darwin8.x) */
2251                 error = conn->ksnc_sock->sk->sk_err;
2252                 if (error != 0) {
2253                         ksocknal_conn_addref(conn);
2254
2255                         switch (error) {
2256                         case ECONNRESET:
2257                                 CNETERR("A connection with %s (%pI4h:%d) was reset; it may have rebooted.\n",
2258                                         libcfs_id2str(peer->ksnp_id),
2259                                         &conn->ksnc_ipaddr,
2260                                         conn->ksnc_port);
2261                                 break;
2262                         case ETIMEDOUT:
2263                                 CNETERR("A connection with %s (%pI4h:%d) timed out; the network or node may be down.\n",
2264                                         libcfs_id2str(peer->ksnp_id),
2265                                         &conn->ksnc_ipaddr,
2266                                         conn->ksnc_port);
2267                                 break;
2268                         default:
2269                                 CNETERR("An unexpected network error %d occurred with %s (%pI4h:%d\n",
2270                                         error,
2271                                         libcfs_id2str(peer->ksnp_id),
2272                                         &conn->ksnc_ipaddr,
2273                                         conn->ksnc_port);
2274                                 break;
2275                         }
2276
2277                         return conn;
2278                 }
2279
2280                 if (conn->ksnc_rx_started &&
2281                     cfs_time_aftereq(cfs_time_current(),
2282                                      conn->ksnc_rx_deadline)) {
2283                         /* Timed out incomplete incoming message */
2284                         ksocknal_conn_addref(conn);
2285                         CNETERR("Timeout receiving from %s (%pI4h:%d), state %d wanted %d left %d\n",
2286                                 libcfs_id2str(peer->ksnp_id),
2287                                 &conn->ksnc_ipaddr,
2288                                 conn->ksnc_port,
2289                                 conn->ksnc_rx_state,
2290                                 conn->ksnc_rx_nob_wanted,
2291                                 conn->ksnc_rx_nob_left);
2292                         return conn;
2293                 }
2294
2295                 if ((!list_empty(&conn->ksnc_tx_queue) ||
2296                      conn->ksnc_sock->sk->sk_wmem_queued != 0) &&
2297                     cfs_time_aftereq(cfs_time_current(),
2298                                      conn->ksnc_tx_deadline)) {
2299                         /* Timed out messages queued for sending or
2300                          * buffered in the socket's send buffer */
2301                         ksocknal_conn_addref(conn);
2302                         CNETERR("Timeout sending data to %s (%pI4h:%d) the network or that node may be down.\n",
2303                                 libcfs_id2str(peer->ksnp_id),
2304                                 &conn->ksnc_ipaddr,
2305                                 conn->ksnc_port);
2306                         return conn;
2307                 }
2308         }
2309
2310         return NULL;
2311 }
2312
2313 static inline void
2314 ksocknal_flush_stale_txs(ksock_peer_t *peer)
2315 {
2316         ksock_tx_t      *tx;
2317         LIST_HEAD      (stale_txs);
2318
2319         write_lock_bh(&ksocknal_data.ksnd_global_lock);
2320
2321         while (!list_empty (&peer->ksnp_tx_queue)) {
2322                 tx = list_entry (peer->ksnp_tx_queue.next,
2323                                      ksock_tx_t, tx_list);
2324
2325                 if (!cfs_time_aftereq(cfs_time_current(),
2326                                       tx->tx_deadline))
2327                         break;
2328
2329                 list_del (&tx->tx_list);
2330                 list_add_tail (&tx->tx_list, &stale_txs);
2331         }
2332
2333         write_unlock_bh(&ksocknal_data.ksnd_global_lock);
2334
2335         ksocknal_txlist_done(peer->ksnp_ni, &stale_txs, 1);
2336 }
2337
2338 static int
2339 ksocknal_send_keepalive_locked(ksock_peer_t *peer)
2340 {
2341         ksock_sched_t  *sched;
2342         ksock_conn_t   *conn;
2343         ksock_tx_t     *tx;
2344
2345         if (list_empty(&peer->ksnp_conns)) /* last_alive will be updated by create_conn */
2346                 return 0;
2347
2348         if (peer->ksnp_proto != &ksocknal_protocol_v3x)
2349                 return 0;
2350
2351         if (*ksocknal_tunables.ksnd_keepalive <= 0 ||
2352             time_before(cfs_time_current(),
2353                         cfs_time_add(peer->ksnp_last_alive,
2354                                      cfs_time_seconds(*ksocknal_tunables.ksnd_keepalive))))
2355                 return 0;
2356
2357         if (time_before(cfs_time_current(), peer->ksnp_send_keepalive))
2358                 return 0;
2359
2360         /* retry 10 secs later, so we wouldn't put pressure
2361          * on this peer if we failed to send keepalive this time */
2362         peer->ksnp_send_keepalive = cfs_time_shift(10);
2363
2364         conn = ksocknal_find_conn_locked(peer, NULL, 1);
2365         if (conn != NULL) {
2366                 sched = conn->ksnc_scheduler;
2367
2368                 spin_lock_bh(&sched->kss_lock);
2369                 if (!list_empty(&conn->ksnc_tx_queue)) {
2370                         spin_unlock_bh(&sched->kss_lock);
2371                         /* there is an queued ACK, don't need keepalive */
2372                         return 0;
2373                 }
2374
2375                 spin_unlock_bh(&sched->kss_lock);
2376         }
2377
2378         read_unlock(&ksocknal_data.ksnd_global_lock);
2379
2380         /* cookie = 1 is reserved for keepalive PING */
2381         tx = ksocknal_alloc_tx_noop(1, 1);
2382         if (tx == NULL) {
2383                 read_lock(&ksocknal_data.ksnd_global_lock);
2384                 return -ENOMEM;
2385         }
2386
2387         if (ksocknal_launch_packet(peer->ksnp_ni, tx, peer->ksnp_id) == 0) {
2388                 read_lock(&ksocknal_data.ksnd_global_lock);
2389                 return 1;
2390         }
2391
2392         ksocknal_free_tx(tx);
2393         read_lock(&ksocknal_data.ksnd_global_lock);
2394
2395         return -EIO;
2396 }
2397
2398
2399 static void
2400 ksocknal_check_peer_timeouts (int idx)
2401 {
2402         struct list_head       *peers = &ksocknal_data.ksnd_peers[idx];
2403         ksock_peer_t     *peer;
2404         ksock_conn_t     *conn;
2405         ksock_tx_t       *tx;
2406
2407  again:
2408         /* NB. We expect to have a look at all the peers and not find any
2409          * connections to time out, so we just use a shared lock while we
2410          * take a look... */
2411         read_lock(&ksocknal_data.ksnd_global_lock);
2412
2413         list_for_each_entry(peer, peers, ksnp_list) {
2414                 unsigned long  deadline = 0;
2415                 int      resid = 0;
2416                 int      n     = 0;
2417
2418                 if (ksocknal_send_keepalive_locked(peer) != 0) {
2419                         read_unlock(&ksocknal_data.ksnd_global_lock);
2420                         goto again;
2421                 }
2422
2423                 conn = ksocknal_find_timed_out_conn (peer);
2424
2425                 if (conn != NULL) {
2426                         read_unlock(&ksocknal_data.ksnd_global_lock);
2427
2428                         ksocknal_close_conn_and_siblings (conn, -ETIMEDOUT);
2429
2430                         /* NB we won't find this one again, but we can't
2431                          * just proceed with the next peer, since we dropped
2432                          * ksnd_global_lock and it might be dead already! */
2433                         ksocknal_conn_decref(conn);
2434                         goto again;
2435                 }
2436
2437                 /* we can't process stale txs right here because we're
2438                  * holding only shared lock */
2439                 if (!list_empty (&peer->ksnp_tx_queue)) {
2440                         ksock_tx_t *tx =
2441                                 list_entry (peer->ksnp_tx_queue.next,
2442                                                 ksock_tx_t, tx_list);
2443
2444                         if (cfs_time_aftereq(cfs_time_current(),
2445                                              tx->tx_deadline)) {
2446
2447                                 ksocknal_peer_addref(peer);
2448                                 read_unlock(&ksocknal_data.ksnd_global_lock);
2449
2450                                 ksocknal_flush_stale_txs(peer);
2451
2452                                 ksocknal_peer_decref(peer);
2453                                 goto again;
2454                         }
2455                 }
2456
2457                 if (list_empty(&peer->ksnp_zc_req_list))
2458                         continue;
2459
2460                 spin_lock(&peer->ksnp_lock);
2461                 list_for_each_entry(tx, &peer->ksnp_zc_req_list, tx_zc_list) {
2462                         if (!cfs_time_aftereq(cfs_time_current(),
2463                                               tx->tx_deadline))
2464                                 break;
2465                         /* ignore the TX if connection is being closed */
2466                         if (tx->tx_conn->ksnc_closing)
2467                                 continue;
2468                         n++;
2469                 }
2470
2471                 if (n == 0) {
2472                         spin_unlock(&peer->ksnp_lock);
2473                         continue;
2474                 }
2475
2476                 tx = list_entry(peer->ksnp_zc_req_list.next,
2477                                     ksock_tx_t, tx_zc_list);
2478                 deadline = tx->tx_deadline;
2479                 resid    = tx->tx_resid;
2480                 conn     = tx->tx_conn;
2481                 ksocknal_conn_addref(conn);
2482
2483                 spin_unlock(&peer->ksnp_lock);
2484                 read_unlock(&ksocknal_data.ksnd_global_lock);
2485
2486                 CERROR("Total %d stale ZC_REQs for peer %s detected; the oldest(%p) timed out %ld secs ago, resid: %d, wmem: %d\n",
2487                        n, libcfs_nid2str(peer->ksnp_id.nid), tx,
2488                        cfs_duration_sec(cfs_time_current() - deadline),
2489                        resid, conn->ksnc_sock->sk->sk_wmem_queued);
2490
2491                 ksocknal_close_conn_and_siblings (conn, -ETIMEDOUT);
2492                 ksocknal_conn_decref(conn);
2493                 goto again;
2494         }
2495
2496         read_unlock(&ksocknal_data.ksnd_global_lock);
2497 }
2498
2499 int
2500 ksocknal_reaper (void *arg)
2501 {
2502         wait_queue_t     wait;
2503         ksock_conn_t      *conn;
2504         ksock_sched_t     *sched;
2505         struct list_head         enomem_conns;
2506         int             nenomem_conns;
2507         long     timeout;
2508         int             i;
2509         int             peer_index = 0;
2510         unsigned long    deadline = cfs_time_current();
2511
2512         cfs_block_allsigs ();
2513
2514         INIT_LIST_HEAD(&enomem_conns);
2515         init_waitqueue_entry(&wait, current);
2516
2517         spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
2518
2519         while (!ksocknal_data.ksnd_shuttingdown) {
2520
2521                 if (!list_empty (&ksocknal_data.ksnd_deathrow_conns)) {
2522                         conn = list_entry (ksocknal_data. \
2523                                                ksnd_deathrow_conns.next,
2524                                                ksock_conn_t, ksnc_list);
2525                         list_del (&conn->ksnc_list);
2526
2527                         spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
2528
2529                         ksocknal_terminate_conn(conn);
2530                         ksocknal_conn_decref(conn);
2531
2532                         spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
2533                         continue;
2534                 }
2535
2536                 if (!list_empty (&ksocknal_data.ksnd_zombie_conns)) {
2537                         conn = list_entry (ksocknal_data.ksnd_zombie_conns.\
2538                                                next, ksock_conn_t, ksnc_list);
2539                         list_del (&conn->ksnc_list);
2540
2541                         spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
2542
2543                         ksocknal_destroy_conn(conn);
2544
2545                         spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
2546                         continue;
2547                 }
2548
2549                 if (!list_empty (&ksocknal_data.ksnd_enomem_conns)) {
2550                         list_add(&enomem_conns,
2551                                      &ksocknal_data.ksnd_enomem_conns);
2552                         list_del_init(&ksocknal_data.ksnd_enomem_conns);
2553                 }
2554
2555                 spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
2556
2557                 /* reschedule all the connections that stalled with ENOMEM... */
2558                 nenomem_conns = 0;
2559                 while (!list_empty (&enomem_conns)) {
2560                         conn = list_entry (enomem_conns.next,
2561                                                ksock_conn_t, ksnc_tx_list);
2562                         list_del (&conn->ksnc_tx_list);
2563
2564                         sched = conn->ksnc_scheduler;
2565
2566                         spin_lock_bh(&sched->kss_lock);
2567
2568                         LASSERT(conn->ksnc_tx_scheduled);
2569                         conn->ksnc_tx_ready = 1;
2570                         list_add_tail(&conn->ksnc_tx_list,
2571                                           &sched->kss_tx_conns);
2572                         wake_up(&sched->kss_waitq);
2573
2574                         spin_unlock_bh(&sched->kss_lock);
2575                         nenomem_conns++;
2576                 }
2577
2578                 /* careful with the jiffy wrap... */
2579                 while ((timeout = cfs_time_sub(deadline,
2580                                                cfs_time_current())) <= 0) {
2581                         const int n = 4;
2582                         const int p = 1;
2583                         int       chunk = ksocknal_data.ksnd_peer_hash_size;
2584
2585                         /* Time to check for timeouts on a few more peers: I do
2586                          * checks every 'p' seconds on a proportion of the peer
2587                          * table and I need to check every connection 'n' times
2588                          * within a timeout interval, to ensure I detect a
2589                          * timeout on any connection within (n+1)/n times the
2590                          * timeout interval. */
2591
2592                         if (*ksocknal_tunables.ksnd_timeout > n * p)
2593                                 chunk = (chunk * n * p) /
2594                                         *ksocknal_tunables.ksnd_timeout;
2595                         if (chunk == 0)
2596                                 chunk = 1;
2597
2598                         for (i = 0; i < chunk; i++) {
2599                                 ksocknal_check_peer_timeouts (peer_index);
2600                                 peer_index = (peer_index + 1) %
2601                                              ksocknal_data.ksnd_peer_hash_size;
2602                         }
2603
2604                         deadline = cfs_time_add(deadline, cfs_time_seconds(p));
2605                 }
2606
2607                 if (nenomem_conns != 0) {
2608                         /* Reduce my timeout if I rescheduled ENOMEM conns.
2609                          * This also prevents me getting woken immediately
2610                          * if any go back on my enomem list. */
2611                         timeout = SOCKNAL_ENOMEM_RETRY;
2612                 }
2613                 ksocknal_data.ksnd_reaper_waketime =
2614                         cfs_time_add(cfs_time_current(), timeout);
2615
2616                 set_current_state (TASK_INTERRUPTIBLE);
2617                 add_wait_queue (&ksocknal_data.ksnd_reaper_waitq, &wait);
2618
2619                 if (!ksocknal_data.ksnd_shuttingdown &&
2620                     list_empty (&ksocknal_data.ksnd_deathrow_conns) &&
2621                     list_empty (&ksocknal_data.ksnd_zombie_conns))
2622                         schedule_timeout(timeout);
2623
2624                 set_current_state (TASK_RUNNING);
2625                 remove_wait_queue (&ksocknal_data.ksnd_reaper_waitq, &wait);
2626
2627                 spin_lock_bh(&ksocknal_data.ksnd_reaper_lock);
2628         }
2629
2630         spin_unlock_bh(&ksocknal_data.ksnd_reaper_lock);
2631
2632         ksocknal_thread_fini();
2633         return 0;
2634 }