drivers/staging/lustre/lnet/klnds/socklnd/socklnd_lib-linux.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2012, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  */
  36
  37 #include "socklnd.h"
  38
  39 int
  40 ksocknal_lib_get_conn_addrs (ksock_conn_t *conn)
  41 {
  42         int rc = libcfs_sock_getaddr(conn->ksnc_sock, 1,
  43                                      &conn->ksnc_ipaddr,
  44                                      &conn->ksnc_port);
  45
  46         /* Didn't need the {get,put}connsock dance to deref ksnc_sock... */
  47         LASSERT (!conn->ksnc_closing);
  48
  49         if (rc != 0) {
  50                 CERROR ("Error %d getting sock peer IP\n", rc);
  51                 return rc;
  52         }
  53
  54         rc = libcfs_sock_getaddr(conn->ksnc_sock, 0,
  55                                  &conn->ksnc_myipaddr, NULL);
  56         if (rc != 0) {
  57                 CERROR ("Error %d getting sock local IP\n", rc);
  58                 return rc;
  59         }
  60
  61         return 0;
  62 }
  63
  64 int
  65 ksocknal_lib_zc_capable(ksock_conn_t *conn)
  66 {
  67         int  caps = conn->ksnc_sock->sk->sk_route_caps;
  68
  69         if (conn->ksnc_proto == &ksocknal_protocol_v1x)
  70                 return 0;
  71
  72         /* ZC if the socket supports scatter/gather and doesn't need software
  73          * checksums */
  74         return ((caps & NETIF_F_SG) != 0 && (caps & NETIF_F_ALL_CSUM) != 0);
  75 }
  76
  77 int
  78 ksocknal_lib_send_iov (ksock_conn_t *conn, ksock_tx_t *tx)
  79 {
  80         struct socket *sock = conn->ksnc_sock;
  81         int         nob;
  82         int         rc;
  83
  84         if (*ksocknal_tunables.ksnd_enable_csum && /* checksum enabled */
  85             conn->ksnc_proto == &ksocknal_protocol_v2x && /* V2.x connection  */
  86             tx->tx_nob == tx->tx_resid           && /* frist sending    */
  87             tx->tx_msg.ksm_csum == 0)                /* not checksummed  */
  88                 ksocknal_lib_csum_tx(tx);
  89
  90         /* NB we can't trust socket ops to either consume our iovs
  91          * or leave them alone. */
  92
  93         {
  94 #if SOCKNAL_SINGLE_FRAG_TX
  95                 struct iovec    scratch;
  96                 struct iovec   *scratchiov = &scratch;
  97                 unsigned int    niov = 1;
  98 #else
  99                 struct iovec   *scratchiov = conn->ksnc_scheduler->kss_scratch_iov;
 100                 unsigned int    niov = tx->tx_niov;
 101 #endif
 102                 struct msghdr msg = {
 103                         .msg_name       = NULL,
 104                         .msg_namelen    = 0,
 105                         .msg_iov        = scratchiov,
 106                         .msg_iovlen     = niov,
 107                         .msg_control    = NULL,
 108                         .msg_controllen = 0,
 109                         .msg_flags      = MSG_DONTWAIT
 110                 };
 111                 mm_segment_t oldmm = get_fs();
 112                 int  i;
 113
 114                 for (nob = i = 0; i < niov; i++) {
 115                         scratchiov[i] = tx->tx_iov[i];
 116                         nob += scratchiov[i].iov_len;
 117                 }
 118
 119                 if (!list_empty(&conn->ksnc_tx_queue) ||
 120                     nob < tx->tx_resid)
 121                         msg.msg_flags |= MSG_MORE;
 122
 123                 set_fs (KERNEL_DS);
 124                 rc = sock_sendmsg(sock, &msg, nob);
 125                 set_fs (oldmm);
 126         }
 127         return rc;
 128 }
 129
 130 int
 131 ksocknal_lib_send_kiov (ksock_conn_t *conn, ksock_tx_t *tx)
 132 {
 133         struct socket *sock = conn->ksnc_sock;
 134         lnet_kiov_t   *kiov = tx->tx_kiov;
 135         int         rc;
 136         int         nob;
 137
 138         /* Not NOOP message */
 139         LASSERT (tx->tx_lnetmsg != NULL);
 140
 141         /* NB we can't trust socket ops to either consume our iovs
 142          * or leave them alone. */
 143         if (tx->tx_msg.ksm_zc_cookies[0] != 0) {
 144                 /* Zero copy is enabled */
 145                 struct sock   *sk = sock->sk;
 146                 struct page   *page = kiov->kiov_page;
 147                 int         offset = kiov->kiov_offset;
 148                 int         fragsize = kiov->kiov_len;
 149                 int         msgflg = MSG_DONTWAIT;
 150
 151                 CDEBUG(D_NET, "page %p + offset %x for %d\n",
 152                                page, offset, kiov->kiov_len);
 153
 154                 if (!list_empty(&conn->ksnc_tx_queue) ||
 155                     fragsize < tx->tx_resid)
 156                         msgflg |= MSG_MORE;
 157
 158                 if (sk->sk_prot->sendpage != NULL) {
 159                         rc = sk->sk_prot->sendpage(sk, page,
 160                                                    offset, fragsize, msgflg);
 161                 } else {
 162                         rc = cfs_tcp_sendpage(sk, page, offset, fragsize,
 163                                               msgflg);
 164                 }
 165         } else {
 166 #if SOCKNAL_SINGLE_FRAG_TX || !SOCKNAL_RISK_KMAP_DEADLOCK
 167                 struct iovec  scratch;
 168                 struct iovec *scratchiov = &scratch;
 169                 unsigned int  niov = 1;
 170 #else
 171 #ifdef CONFIG_HIGHMEM
 172 #warning "XXX risk of kmap deadlock on multiple frags..."
 173 #endif
 174                 struct iovec *scratchiov = conn->ksnc_scheduler->kss_scratch_iov;
 175                 unsigned int  niov = tx->tx_nkiov;
 176 #endif
 177                 struct msghdr msg = {
 178                         .msg_name       = NULL,
 179                         .msg_namelen    = 0,
 180                         .msg_iov        = scratchiov,
 181                         .msg_iovlen     = niov,
 182                         .msg_control    = NULL,
 183                         .msg_controllen = 0,
 184                         .msg_flags      = MSG_DONTWAIT
 185                 };
 186                 mm_segment_t  oldmm = get_fs();
 187                 int        i;
 188
 189                 for (nob = i = 0; i < niov; i++) {
 190                         scratchiov[i].iov_base = kmap(kiov[i].kiov_page) +
 191                                                  kiov[i].kiov_offset;
 192                         nob += scratchiov[i].iov_len = kiov[i].kiov_len;
 193                 }
 194
 195                 if (!list_empty(&conn->ksnc_tx_queue) ||
 196                     nob < tx->tx_resid)
 197                         msg.msg_flags |= MSG_MORE;
 198
 199                 set_fs (KERNEL_DS);
 200                 rc = sock_sendmsg(sock, &msg, nob);
 201                 set_fs (oldmm);
 202
 203                 for (i = 0; i < niov; i++)
 204                         kunmap(kiov[i].kiov_page);
 205         }
 206         return rc;
 207 }
 208
 209 void
 210 ksocknal_lib_eager_ack (ksock_conn_t *conn)
 211 {
 212         int         opt = 1;
 213         mm_segment_t   oldmm = get_fs();
 214         struct socket *sock = conn->ksnc_sock;
 215
 216         /* Remind the socket to ACK eagerly.  If I don't, the socket might
 217          * think I'm about to send something it could piggy-back the ACK
 218          * on, introducing delay in completing zero-copy sends in my
 219          * peer. */
 220
 221         set_fs(KERNEL_DS);
 222         sock->ops->setsockopt (sock, SOL_TCP, TCP_QUICKACK,
 223                                (char *)&opt, sizeof (opt));
 224         set_fs(oldmm);
 225 }
 226
 227 int
 228 ksocknal_lib_recv_iov (ksock_conn_t *conn)
 229 {
 230 #if SOCKNAL_SINGLE_FRAG_RX
 231         struct iovec  scratch;
 232         struct iovec *scratchiov = &scratch;
 233         unsigned int  niov = 1;
 234 #else
 235         struct iovec *scratchiov = conn->ksnc_scheduler->kss_scratch_iov;
 236         unsigned int  niov = conn->ksnc_rx_niov;
 237 #endif
 238         struct iovec *iov = conn->ksnc_rx_iov;
 239         struct msghdr msg = {
 240                 .msg_name       = NULL,
 241                 .msg_namelen    = 0,
 242                 .msg_iov        = scratchiov,
 243                 .msg_iovlen     = niov,
 244                 .msg_control    = NULL,
 245                 .msg_controllen = 0,
 246                 .msg_flags      = 0
 247         };
 248         mm_segment_t oldmm = get_fs();
 249         int       nob;
 250         int       i;
 251         int       rc;
 252         int       fragnob;
 253         int       sum;
 254         __u32   saved_csum;
 255
 256         /* NB we can't trust socket ops to either consume our iovs
 257          * or leave them alone. */
 258         LASSERT (niov > 0);
 259
 260         for (nob = i = 0; i < niov; i++) {
 261                 scratchiov[i] = iov[i];
 262                 nob += scratchiov[i].iov_len;
 263         }
 264         LASSERT (nob <= conn->ksnc_rx_nob_wanted);
 265
 266         set_fs (KERNEL_DS);
 267         rc = sock_recvmsg (conn->ksnc_sock, &msg, nob, MSG_DONTWAIT);
 268         /* NB this is just a boolean..........................^ */
 269         set_fs (oldmm);
 270
 271         saved_csum = 0;
 272         if (conn->ksnc_proto == &ksocknal_protocol_v2x) {
 273                 saved_csum = conn->ksnc_msg.ksm_csum;
 274                 conn->ksnc_msg.ksm_csum = 0;
 275         }
 276
 277         if (saved_csum != 0) {
 278                 /* accumulate checksum */
 279                 for (i = 0, sum = rc; sum > 0; i++, sum -= fragnob) {
 280                         LASSERT (i < niov);
 281
 282                         fragnob = iov[i].iov_len;
 283                         if (fragnob > sum)
 284                                 fragnob = sum;
 285
 286                         conn->ksnc_rx_csum = ksocknal_csum(conn->ksnc_rx_csum,
 287                                                            iov[i].iov_base, fragnob);
 288                 }
 289                 conn->ksnc_msg.ksm_csum = saved_csum;
 290         }
 291
 292         return rc;
 293 }
 294
 295 static void
 296 ksocknal_lib_kiov_vunmap(void *addr)
 297 {
 298         if (addr == NULL)
 299                 return;
 300
 301         vunmap(addr);
 302 }
 303
 304 static void *
 305 ksocknal_lib_kiov_vmap(lnet_kiov_t *kiov, int niov,
 306                        struct iovec *iov, struct page **pages)
 307 {
 308         void         *addr;
 309         int            nob;
 310         int            i;
 311
 312         if (!*ksocknal_tunables.ksnd_zc_recv || pages == NULL)
 313                 return NULL;
 314
 315         LASSERT (niov <= LNET_MAX_IOV);
 316
 317         if (niov < 2 ||
 318             niov < *ksocknal_tunables.ksnd_zc_recv_min_nfrags)
 319                 return NULL;
 320
 321         for (nob = i = 0; i < niov; i++) {
 322                 if ((kiov[i].kiov_offset != 0 && i > 0) ||
 323                     (kiov[i].kiov_offset + kiov[i].kiov_len != PAGE_CACHE_SIZE && i < niov - 1))
 324                         return NULL;
 325
 326                 pages[i] = kiov[i].kiov_page;
 327                 nob += kiov[i].kiov_len;
 328         }
 329
 330         addr = vmap(pages, niov, VM_MAP, PAGE_KERNEL);
 331         if (addr == NULL)
 332                 return NULL;
 333
 334         iov->iov_base = addr + kiov[0].kiov_offset;
 335         iov->iov_len = nob;
 336
 337         return addr;
 338 }
 339
 340 int
 341 ksocknal_lib_recv_kiov (ksock_conn_t *conn)
 342 {
 343 #if SOCKNAL_SINGLE_FRAG_RX || !SOCKNAL_RISK_KMAP_DEADLOCK
 344         struct iovec   scratch;
 345         struct iovec  *scratchiov = &scratch;
 346         struct page  **pages      = NULL;
 347         unsigned int   niov       = 1;
 348 #else
 349 #ifdef CONFIG_HIGHMEM
 350 #warning "XXX risk of kmap deadlock on multiple frags..."
 351 #endif
 352         struct iovec  *scratchiov = conn->ksnc_scheduler->kss_scratch_iov;
 353         struct page  **pages      = conn->ksnc_scheduler->kss_rx_scratch_pgs;
 354         unsigned int   niov       = conn->ksnc_rx_nkiov;
 355 #endif
 356         lnet_kiov_t   *kiov = conn->ksnc_rx_kiov;
 357         struct msghdr msg = {
 358                 .msg_name       = NULL,
 359                 .msg_namelen    = 0,
 360                 .msg_iov        = scratchiov,
 361                 .msg_control    = NULL,
 362                 .msg_controllen = 0,
 363                 .msg_flags      = 0
 364         };
 365         mm_segment_t oldmm = get_fs();
 366         int       nob;
 367         int       i;
 368         int       rc;
 369         void    *base;
 370         void    *addr;
 371         int       sum;
 372         int       fragnob;
 373
 374         /* NB we can't trust socket ops to either consume our iovs
 375          * or leave them alone. */
 376         addr = ksocknal_lib_kiov_vmap(kiov, niov, scratchiov, pages);
 377         if (addr != NULL) {
 378                 nob = scratchiov[0].iov_len;
 379                 msg.msg_iovlen = 1;
 380
 381         } else {
 382                 for (nob = i = 0; i < niov; i++) {
 383                         nob += scratchiov[i].iov_len = kiov[i].kiov_len;
 384                         scratchiov[i].iov_base = kmap(kiov[i].kiov_page) +
 385                                                  kiov[i].kiov_offset;
 386                 }
 387                 msg.msg_iovlen = niov;
 388         }
 389
 390         LASSERT (nob <= conn->ksnc_rx_nob_wanted);
 391
 392         set_fs (KERNEL_DS);
 393         rc = sock_recvmsg (conn->ksnc_sock, &msg, nob, MSG_DONTWAIT);
 394         /* NB this is just a boolean.......................^ */
 395         set_fs (oldmm);
 396
 397         if (conn->ksnc_msg.ksm_csum != 0) {
 398                 for (i = 0, sum = rc; sum > 0; i++, sum -= fragnob) {
 399                         LASSERT (i < niov);
 400
 401                         /* Dang! have to kmap again because I have nowhere to stash the
 402                          * mapped address.  But by doing it while the page is still
 403                          * mapped, the kernel just bumps the map count and returns me
 404                          * the address it stashed. */
 405                         base = kmap(kiov[i].kiov_page) + kiov[i].kiov_offset;
 406                         fragnob = kiov[i].kiov_len;
 407                         if (fragnob > sum)
 408                                 fragnob = sum;
 409
 410                         conn->ksnc_rx_csum = ksocknal_csum(conn->ksnc_rx_csum,
 411                                                            base, fragnob);
 412
 413                         kunmap(kiov[i].kiov_page);
 414                 }
 415         }
 416
 417         if (addr != NULL) {
 418                 ksocknal_lib_kiov_vunmap(addr);
 419         } else {
 420                 for (i = 0; i < niov; i++)
 421                         kunmap(kiov[i].kiov_page);
 422         }
 423
 424         return (rc);
 425 }
 426
 427 void
 428 ksocknal_lib_csum_tx(ksock_tx_t *tx)
 429 {
 430         int       i;
 431         __u32   csum;
 432         void    *base;
 433
 434         LASSERT(tx->tx_iov[0].iov_base == (void *)&tx->tx_msg);
 435         LASSERT(tx->tx_conn != NULL);
 436         LASSERT(tx->tx_conn->ksnc_proto == &ksocknal_protocol_v2x);
 437
 438         tx->tx_msg.ksm_csum = 0;
 439
 440         csum = ksocknal_csum(~0, (void *)tx->tx_iov[0].iov_base,
 441                              tx->tx_iov[0].iov_len);
 442
 443         if (tx->tx_kiov != NULL) {
 444                 for (i = 0; i < tx->tx_nkiov; i++) {
 445                         base = kmap(tx->tx_kiov[i].kiov_page) +
 446                                tx->tx_kiov[i].kiov_offset;
 447
 448                         csum = ksocknal_csum(csum, base, tx->tx_kiov[i].kiov_len);
 449
 450                         kunmap(tx->tx_kiov[i].kiov_page);
 451                 }
 452         } else {
 453                 for (i = 1; i < tx->tx_niov; i++)
 454                         csum = ksocknal_csum(csum, tx->tx_iov[i].iov_base,
 455                                              tx->tx_iov[i].iov_len);
 456         }
 457
 458         if (*ksocknal_tunables.ksnd_inject_csum_error) {
 459                 csum++;
 460                 *ksocknal_tunables.ksnd_inject_csum_error = 0;
 461         }
 462
 463         tx->tx_msg.ksm_csum = csum;
 464 }
 465
 466 int
 467 ksocknal_lib_get_conn_tunables (ksock_conn_t *conn, int *txmem, int *rxmem, int *nagle)
 468 {
 469         mm_segment_t   oldmm = get_fs ();
 470         struct socket *sock = conn->ksnc_sock;
 471         int         len;
 472         int         rc;
 473
 474         rc = ksocknal_connsock_addref(conn);
 475         if (rc != 0) {
 476                 LASSERT (conn->ksnc_closing);
 477                 *txmem = *rxmem = *nagle = 0;
 478                 return (-ESHUTDOWN);
 479         }
 480
 481         rc = libcfs_sock_getbuf(sock, txmem, rxmem);
 482         if (rc == 0) {
 483                 len = sizeof(*nagle);
 484                 set_fs(KERNEL_DS);
 485                 rc = sock->ops->getsockopt(sock, SOL_TCP, TCP_NODELAY,
 486                                            (char *)nagle, &len);
 487                 set_fs(oldmm);
 488         }
 489
 490         ksocknal_connsock_decref(conn);
 491
 492         if (rc == 0)
 493                 *nagle = !*nagle;
 494         else
 495                 *txmem = *rxmem = *nagle = 0;
 496
 497         return (rc);
 498 }
 499
 500 int
 501 ksocknal_lib_setup_sock (struct socket *sock)
 502 {
 503         mm_segment_t    oldmm = get_fs ();
 504         int          rc;
 505         int          option;
 506         int          keep_idle;
 507         int          keep_intvl;
 508         int          keep_count;
 509         int          do_keepalive;
 510         struct linger   linger;
 511
 512         sock->sk->sk_allocation = GFP_NOFS;
 513
 514         /* Ensure this socket aborts active sends immediately when we close
 515          * it. */
 516
 517         linger.l_onoff = 0;
 518         linger.l_linger = 0;
 519
 520         set_fs (KERNEL_DS);
 521         rc = sock_setsockopt (sock, SOL_SOCKET, SO_LINGER,
 522                               (char *)&linger, sizeof (linger));
 523         set_fs (oldmm);
 524         if (rc != 0) {
 525                 CERROR ("Can't set SO_LINGER: %d\n", rc);
 526                 return (rc);
 527         }
 528
 529         option = -1;
 530         set_fs (KERNEL_DS);
 531         rc = sock->ops->setsockopt (sock, SOL_TCP, TCP_LINGER2,
 532                                     (char *)&option, sizeof (option));
 533         set_fs (oldmm);
 534         if (rc != 0) {
 535                 CERROR ("Can't set SO_LINGER2: %d\n", rc);
 536                 return (rc);
 537         }
 538
 539         if (!*ksocknal_tunables.ksnd_nagle) {
 540                 option = 1;
 541
 542                 set_fs (KERNEL_DS);
 543                 rc = sock->ops->setsockopt (sock, SOL_TCP, TCP_NODELAY,
 544                                             (char *)&option, sizeof (option));
 545                 set_fs (oldmm);
 546                 if (rc != 0) {
 547                         CERROR ("Can't disable nagle: %d\n", rc);
 548                         return (rc);
 549                 }
 550         }
 551
 552         rc = libcfs_sock_setbuf(sock,
 553                                 *ksocknal_tunables.ksnd_tx_buffer_size,
 554                                 *ksocknal_tunables.ksnd_rx_buffer_size);
 555         if (rc != 0) {
 556                 CERROR ("Can't set buffer tx %d, rx %d buffers: %d\n",
 557                         *ksocknal_tunables.ksnd_tx_buffer_size,
 558                         *ksocknal_tunables.ksnd_rx_buffer_size, rc);
 559                 return (rc);
 560         }
 561
 562 /* TCP_BACKOFF_* sockopt tunables unsupported in stock kernels */
 563
 564         /* snapshot tunables */
 565         keep_idle  = *ksocknal_tunables.ksnd_keepalive_idle;
 566         keep_count = *ksocknal_tunables.ksnd_keepalive_count;
 567         keep_intvl = *ksocknal_tunables.ksnd_keepalive_intvl;
 568
 569         do_keepalive = (keep_idle > 0 && keep_count > 0 && keep_intvl > 0);
 570
 571         option = (do_keepalive ? 1 : 0);
 572         set_fs (KERNEL_DS);
 573         rc = sock_setsockopt (sock, SOL_SOCKET, SO_KEEPALIVE,
 574                               (char *)&option, sizeof (option));
 575         set_fs (oldmm);
 576         if (rc != 0) {
 577                 CERROR ("Can't set SO_KEEPALIVE: %d\n", rc);
 578                 return (rc);
 579         }
 580
 581         if (!do_keepalive)
 582                 return (0);
 583
 584         set_fs (KERNEL_DS);
 585         rc = sock->ops->setsockopt (sock, SOL_TCP, TCP_KEEPIDLE,
 586                                     (char *)&keep_idle, sizeof (keep_idle));
 587         set_fs (oldmm);
 588         if (rc != 0) {
 589                 CERROR ("Can't set TCP_KEEPIDLE: %d\n", rc);
 590                 return (rc);
 591         }
 592
 593         set_fs (KERNEL_DS);
 594         rc = sock->ops->setsockopt (sock, SOL_TCP, TCP_KEEPINTVL,
 595                                     (char *)&keep_intvl, sizeof (keep_intvl));
 596         set_fs (oldmm);
 597         if (rc != 0) {
 598                 CERROR ("Can't set TCP_KEEPINTVL: %d\n", rc);
 599                 return (rc);
 600         }
 601
 602         set_fs (KERNEL_DS);
 603         rc = sock->ops->setsockopt (sock, SOL_TCP, TCP_KEEPCNT,
 604                                     (char *)&keep_count, sizeof (keep_count));
 605         set_fs (oldmm);
 606         if (rc != 0) {
 607                 CERROR ("Can't set TCP_KEEPCNT: %d\n", rc);
 608                 return (rc);
 609         }
 610
 611         return (0);
 612 }
 613
 614 void
 615 ksocknal_lib_push_conn (ksock_conn_t *conn)
 616 {
 617         struct sock    *sk;
 618         struct tcp_sock *tp;
 619         int          nonagle;
 620         int          val = 1;
 621         int          rc;
 622         mm_segment_t    oldmm;
 623
 624         rc = ksocknal_connsock_addref(conn);
 625         if (rc != 0)                        /* being shut down */
 626                 return;
 627
 628         sk = conn->ksnc_sock->sk;
 629         tp = tcp_sk(sk);
 630
 631         lock_sock (sk);
 632         nonagle = tp->nonagle;
 633         tp->nonagle = 1;
 634         release_sock (sk);
 635
 636         oldmm = get_fs ();
 637         set_fs (KERNEL_DS);
 638
 639         rc = sk->sk_prot->setsockopt (sk, SOL_TCP, TCP_NODELAY,
 640                                       (char *)&val, sizeof (val));
 641         LASSERT (rc == 0);
 642
 643         set_fs (oldmm);
 644
 645         lock_sock (sk);
 646         tp->nonagle = nonagle;
 647         release_sock (sk);
 648
 649         ksocknal_connsock_decref(conn);
 650 }
 651
 652 extern void ksocknal_read_callback (ksock_conn_t *conn);
 653 extern void ksocknal_write_callback (ksock_conn_t *conn);
 654 /*
 655  * socket call back in Linux
 656  */
 657 static void
 658 ksocknal_data_ready (struct sock *sk, int n)
 659 {
 660         ksock_conn_t  *conn;
 661
 662         /* interleave correctly with closing sockets... */
 663         LASSERT(!in_irq());
 664         read_lock(&ksocknal_data.ksnd_global_lock);
 665
 666         conn = sk->sk_user_data;
 667         if (conn == NULL) {          /* raced with ksocknal_terminate_conn */
 668                 LASSERT (sk->sk_data_ready != &ksocknal_data_ready);
 669                 sk->sk_data_ready (sk, n);
 670         } else
 671                 ksocknal_read_callback(conn);
 672
 673         read_unlock(&ksocknal_data.ksnd_global_lock);
 674 }
 675
 676 static void
 677 ksocknal_write_space (struct sock *sk)
 678 {
 679         ksock_conn_t  *conn;
 680         int         wspace;
 681         int         min_wpace;
 682
 683         /* interleave correctly with closing sockets... */
 684         LASSERT(!in_irq());
 685         read_lock(&ksocknal_data.ksnd_global_lock);
 686
 687         conn = sk->sk_user_data;
 688         wspace = SOCKNAL_WSPACE(sk);
 689         min_wpace = SOCKNAL_MIN_WSPACE(sk);
 690
 691         CDEBUG(D_NET, "sk %p wspace %d low water %d conn %p%s%s%s\n",
 692                sk, wspace, min_wpace, conn,
 693                (conn == NULL) ? "" : (conn->ksnc_tx_ready ?
 694                                       " ready" : " blocked"),
 695                (conn == NULL) ? "" : (conn->ksnc_tx_scheduled ?
 696                                       " scheduled" : " idle"),
 697                (conn == NULL) ? "" : (list_empty (&conn->ksnc_tx_queue) ?
 698                                       " empty" : " queued"));
 699
 700         if (conn == NULL) {          /* raced with ksocknal_terminate_conn */
 701                 LASSERT (sk->sk_write_space != &ksocknal_write_space);
 702                 sk->sk_write_space (sk);
 703
 704                 read_unlock(&ksocknal_data.ksnd_global_lock);
 705                 return;
 706         }
 707
 708         if (wspace >= min_wpace) {            /* got enough space */
 709                 ksocknal_write_callback(conn);
 710
 711                 /* Clear SOCK_NOSPACE _after_ ksocknal_write_callback so the
 712                  * ENOMEM check in ksocknal_transmit is race-free (think about
 713                  * it). */
 714
 715                 clear_bit (SOCK_NOSPACE, &sk->sk_socket->flags);
 716         }
 717
 718         read_unlock(&ksocknal_data.ksnd_global_lock);
 719 }
 720
 721 void
 722 ksocknal_lib_save_callback(struct socket *sock, ksock_conn_t *conn)
 723 {
 724         conn->ksnc_saved_data_ready = sock->sk->sk_data_ready;
 725         conn->ksnc_saved_write_space = sock->sk->sk_write_space;
 726 }
 727
 728 void
 729 ksocknal_lib_set_callback(struct socket *sock,  ksock_conn_t *conn)
 730 {
 731         sock->sk->sk_user_data = conn;
 732         sock->sk->sk_data_ready = ksocknal_data_ready;
 733         sock->sk->sk_write_space = ksocknal_write_space;
 734         return;
 735 }
 736
 737 void
 738 ksocknal_lib_reset_callback(struct socket *sock, ksock_conn_t *conn)
 739 {
 740         /* Remove conn's network callbacks.
 741          * NB I _have_ to restore the callback, rather than storing a noop,
 742          * since the socket could survive past this module being unloaded!! */
 743         sock->sk->sk_data_ready = conn->ksnc_saved_data_ready;
 744         sock->sk->sk_write_space = conn->ksnc_saved_write_space;
 745
 746         /* A callback could be in progress already; they hold a read lock
 747          * on ksnd_global_lock (to serialise with me) and NOOP if
 748          * sk_user_data is NULL. */
 749         sock->sk->sk_user_data = NULL;
 750
 751         return ;
 752 }
 753
 754 int
 755 ksocknal_lib_memory_pressure(ksock_conn_t *conn)
 756 {
 757         int         rc = 0;
 758         ksock_sched_t *sched;
 759
 760         sched = conn->ksnc_scheduler;
 761         spin_lock_bh(&sched->kss_lock);
 762
 763         if (!SOCK_TEST_NOSPACE(conn->ksnc_sock) &&
 764             !conn->ksnc_tx_ready) {
 765                 /* SOCK_NOSPACE is set when the socket fills
 766                  * and cleared in the write_space callback
 767                  * (which also sets ksnc_tx_ready).  If
 768                  * SOCK_NOSPACE and ksnc_tx_ready are BOTH
 769                  * zero, I didn't fill the socket and
 770                  * write_space won't reschedule me, so I
 771                  * return -ENOMEM to get my caller to retry
 772                  * after a timeout */
 773                 rc = -ENOMEM;
 774         }
 775
 776         spin_unlock_bh(&sched->kss_lock);
 777
 778         return rc;
 779 }