net/sunrpc/xprtsock.c

   1 /*
   2  * linux/net/sunrpc/xprtsock.c
   3  *
   4  * Client-side transport implementation for sockets.
   5  *
   6  * TCP callback races fixes (C) 1998 Red Hat Software <alan@redhat.com>
   7  * TCP send fixes (C) 1998 Red Hat Software <alan@redhat.com>
   8  * TCP NFS related read + write fixes
   9  *  (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
  10  *
  11  * Rewrite of larges part of the code in order to stabilize TCP stuff.
  12  * Fix behaviour when socket buffer is full.
  13  *  (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
  14  *
  15  * IP socket transport implementation, (C) 2005 Chuck Lever <cel@netapp.com>
  16  */
  17
  18 #include <linux/types.h>
  19 #include <linux/slab.h>
  20 #include <linux/capability.h>
  21 #include <linux/sched.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/errno.h>
  24 #include <linux/socket.h>
  25 #include <linux/in.h>
  26 #include <linux/net.h>
  27 #include <linux/mm.h>
  28 #include <linux/udp.h>
  29 #include <linux/tcp.h>
  30 #include <linux/sunrpc/clnt.h>
  31 #include <linux/sunrpc/sched.h>
  32 #include <linux/file.h>
  33
  34 #include <net/sock.h>
  35 #include <net/checksum.h>
  36 #include <net/udp.h>
  37 #include <net/tcp.h>
  38
  39 /*
  40  * xprtsock tunables
  41  */
  42 unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  43 unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  44
  45 unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
  46 unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
  47
  48 /*
  49  * How many times to try sending a request on a socket before waiting
  50  * for the socket buffer to clear.
  51  */
  52 #define XS_SENDMSG_RETRY        (10U)
  53
  54 /*
  55  * Time out for an RPC UDP socket connect.  UDP socket connects are
  56  * synchronous, but we set a timeout anyway in case of resource
  57  * exhaustion on the local host.
  58  */
  59 #define XS_UDP_CONN_TO          (5U * HZ)
  60
  61 /*
  62  * Wait duration for an RPC TCP connection to be established.  Solaris
  63  * NFS over TCP uses 60 seconds, for example, which is in line with how
  64  * long a server takes to reboot.
  65  */
  66 #define XS_TCP_CONN_TO          (60U * HZ)
  67
  68 /*
  69  * Wait duration for a reply from the RPC portmapper.
  70  */
  71 #define XS_BIND_TO              (60U * HZ)
  72
  73 /*
  74  * Delay if a UDP socket connect error occurs.  This is most likely some
  75  * kind of resource problem on the local host.
  76  */
  77 #define XS_UDP_REEST_TO         (2U * HZ)
  78
  79 /*
  80  * The reestablish timeout allows clients to delay for a bit before attempting
  81  * to reconnect to a server that just dropped our connection.
  82  *
  83  * We implement an exponential backoff when trying to reestablish a TCP
  84  * transport connection with the server.  Some servers like to drop a TCP
  85  * connection when they are overworked, so we start with a short timeout and
  86  * increase over time if the server is down or not responding.
  87  */
  88 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
  89 #define XS_TCP_MAX_REEST_TO     (5U * 60 * HZ)
  90
  91 /*
  92  * TCP idle timeout; client drops the transport socket if it is idle
  93  * for this long.  Note that we also timeout UDP sockets to prevent
  94  * holding port numbers when there is no RPC traffic.
  95  */
  96 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
  97
  98 #ifdef RPC_DEBUG
  99 # undef  RPC_DEBUG_DATA
 100 # define RPCDBG_FACILITY        RPCDBG_TRANS
 101 #endif
 102
 103 #ifdef RPC_DEBUG_DATA
 104 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 105 {
 106         u8 *buf = (u8 *) packet;
 107         int j;
 108
 109         dprintk("RPC:      %s\n", msg);
 110         for (j = 0; j < count && j < 128; j += 4) {
 111                 if (!(j & 31)) {
 112                         if (j)
 113                                 dprintk("\n");
 114                         dprintk("0x%04x ", j);
 115                 }
 116                 dprintk("%02x%02x%02x%02x ",
 117                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
 118         }
 119         dprintk("\n");
 120 }
 121 #else
 122 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 123 {
 124         /* NOP */
 125 }
 126 #endif
 127
 128 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
 129
 130 static inline int xs_send_head(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, unsigned int len)
 131 {
 132         struct kvec iov = {
 133                 .iov_base       = xdr->head[0].iov_base + base,
 134                 .iov_len        = len - base,
 135         };
 136         struct msghdr msg = {
 137                 .msg_name       = addr,
 138                 .msg_namelen    = addrlen,
 139                 .msg_flags      = XS_SENDMSG_FLAGS,
 140         };
 141
 142         if (xdr->len > len)
 143                 msg.msg_flags |= MSG_MORE;
 144
 145         if (likely(iov.iov_len))
 146                 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
 147         return kernel_sendmsg(sock, &msg, NULL, 0, 0);
 148 }
 149
 150 static int xs_send_tail(struct socket *sock, struct xdr_buf *xdr, unsigned int base, unsigned int len)
 151 {
 152         struct kvec iov = {
 153                 .iov_base       = xdr->tail[0].iov_base + base,
 154                 .iov_len        = len - base,
 155         };
 156         struct msghdr msg = {
 157                 .msg_flags      = XS_SENDMSG_FLAGS,
 158         };
 159
 160         return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
 161 }
 162
 163 /**
 164  * xs_sendpages - write pages directly to a socket
 165  * @sock: socket to send on
 166  * @addr: UDP only -- address of destination
 167  * @addrlen: UDP only -- length of destination address
 168  * @xdr: buffer containing this request
 169  * @base: starting position in the buffer
 170  *
 171  */
 172 static inline int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
 173 {
 174         struct page **ppage = xdr->pages;
 175         unsigned int len, pglen = xdr->page_len;
 176         int err, ret = 0;
 177         ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
 178
 179         if (unlikely(!sock))
 180                 return -ENOTCONN;
 181
 182         clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
 183
 184         len = xdr->head[0].iov_len;
 185         if (base < len || (addr != NULL && base == 0)) {
 186                 err = xs_send_head(sock, addr, addrlen, xdr, base, len);
 187                 if (ret == 0)
 188                         ret = err;
 189                 else if (err > 0)
 190                         ret += err;
 191                 if (err != (len - base))
 192                         goto out;
 193                 base = 0;
 194         } else
 195                 base -= len;
 196
 197         if (unlikely(pglen == 0))
 198                 goto copy_tail;
 199         if (unlikely(base >= pglen)) {
 200                 base -= pglen;
 201                 goto copy_tail;
 202         }
 203         if (base || xdr->page_base) {
 204                 pglen -= base;
 205                 base += xdr->page_base;
 206                 ppage += base >> PAGE_CACHE_SHIFT;
 207                 base &= ~PAGE_CACHE_MASK;
 208         }
 209
 210         sendpage = sock->ops->sendpage ? : sock_no_sendpage;
 211         do {
 212                 int flags = XS_SENDMSG_FLAGS;
 213
 214                 len = PAGE_CACHE_SIZE;
 215                 if (base)
 216                         len -= base;
 217                 if (pglen < len)
 218                         len = pglen;
 219
 220                 if (pglen != len || xdr->tail[0].iov_len != 0)
 221                         flags |= MSG_MORE;
 222
 223                 /* Hmm... We might be dealing with highmem pages */
 224                 if (PageHighMem(*ppage))
 225                         sendpage = sock_no_sendpage;
 226                 err = sendpage(sock, *ppage, base, len, flags);
 227                 if (ret == 0)
 228                         ret = err;
 229                 else if (err > 0)
 230                         ret += err;
 231                 if (err != len)
 232                         goto out;
 233                 base = 0;
 234                 ppage++;
 235         } while ((pglen -= len) != 0);
 236 copy_tail:
 237         len = xdr->tail[0].iov_len;
 238         if (base < len) {
 239                 err = xs_send_tail(sock, xdr, base, len);
 240                 if (ret == 0)
 241                         ret = err;
 242                 else if (err > 0)
 243                         ret += err;
 244         }
 245 out:
 246         return ret;
 247 }
 248
 249 /**
 250  * xs_nospace - place task on wait queue if transmit was incomplete
 251  * @task: task to put to sleep
 252  *
 253  */
 254 static void xs_nospace(struct rpc_task *task)
 255 {
 256         struct rpc_rqst *req = task->tk_rqstp;
 257         struct rpc_xprt *xprt = req->rq_xprt;
 258
 259         dprintk("RPC: %4d xmit incomplete (%u left of %u)\n",
 260                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
 261                         req->rq_slen);
 262
 263         if (test_bit(SOCK_ASYNC_NOSPACE, &xprt->sock->flags)) {
 264                 /* Protect against races with write_space */
 265                 spin_lock_bh(&xprt->transport_lock);
 266
 267                 /* Don't race with disconnect */
 268                 if (!xprt_connected(xprt))
 269                         task->tk_status = -ENOTCONN;
 270                 else if (test_bit(SOCK_NOSPACE, &xprt->sock->flags))
 271                         xprt_wait_for_buffer_space(task);
 272
 273                 spin_unlock_bh(&xprt->transport_lock);
 274         } else
 275                 /* Keep holding the socket if it is blocked */
 276                 rpc_delay(task, HZ>>4);
 277 }
 278
 279 /**
 280  * xs_udp_send_request - write an RPC request to a UDP socket
 281  * @task: address of RPC task that manages the state of an RPC request
 282  *
 283  * Return values:
 284  *        0:    The request has been sent
 285  *   EAGAIN:    The socket was blocked, please call again later to
 286  *              complete the request
 287  * ENOTCONN:    Caller needs to invoke connect logic then call again
 288  *    other:    Some other error occured, the request was not sent
 289  */
 290 static int xs_udp_send_request(struct rpc_task *task)
 291 {
 292         struct rpc_rqst *req = task->tk_rqstp;
 293         struct rpc_xprt *xprt = req->rq_xprt;
 294         struct xdr_buf *xdr = &req->rq_snd_buf;
 295         int status;
 296
 297         xs_pktdump("packet data:",
 298                                 req->rq_svec->iov_base,
 299                                 req->rq_svec->iov_len);
 300
 301         req->rq_xtime = jiffies;
 302         status = xs_sendpages(xprt->sock, (struct sockaddr *) &xprt->addr,
 303                                 sizeof(xprt->addr), xdr, req->rq_bytes_sent);
 304
 305         dprintk("RPC:      xs_udp_send_request(%u) = %d\n",
 306                         xdr->len - req->rq_bytes_sent, status);
 307
 308         if (likely(status >= (int) req->rq_slen))
 309                 return 0;
 310
 311         /* Still some bytes left; set up for a retry later. */
 312         if (status > 0)
 313                 status = -EAGAIN;
 314
 315         switch (status) {
 316         case -ENETUNREACH:
 317         case -EPIPE:
 318         case -ECONNREFUSED:
 319                 /* When the server has died, an ICMP port unreachable message
 320                  * prompts ECONNREFUSED. */
 321                 break;
 322         case -EAGAIN:
 323                 xs_nospace(task);
 324                 break;
 325         default:
 326                 dprintk("RPC:      sendmsg returned unrecognized error %d\n",
 327                         -status);
 328                 break;
 329         }
 330
 331         return status;
 332 }
 333
 334 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
 335 {
 336         u32 reclen = buf->len - sizeof(rpc_fraghdr);
 337         rpc_fraghdr *base = buf->head[0].iov_base;
 338         *base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
 339 }
 340
 341 /**
 342  * xs_tcp_send_request - write an RPC request to a TCP socket
 343  * @task: address of RPC task that manages the state of an RPC request
 344  *
 345  * Return values:
 346  *        0:    The request has been sent
 347  *   EAGAIN:    The socket was blocked, please call again later to
 348  *              complete the request
 349  * ENOTCONN:    Caller needs to invoke connect logic then call again
 350  *    other:    Some other error occured, the request was not sent
 351  *
 352  * XXX: In the case of soft timeouts, should we eventually give up
 353  *      if sendmsg is not able to make progress?
 354  */
 355 static int xs_tcp_send_request(struct rpc_task *task)
 356 {
 357         struct rpc_rqst *req = task->tk_rqstp;
 358         struct rpc_xprt *xprt = req->rq_xprt;
 359         struct xdr_buf *xdr = &req->rq_snd_buf;
 360         int status, retry = 0;
 361
 362         xs_encode_tcp_record_marker(&req->rq_snd_buf);
 363
 364         xs_pktdump("packet data:",
 365                                 req->rq_svec->iov_base,
 366                                 req->rq_svec->iov_len);
 367
 368         /* Continue transmitting the packet/record. We must be careful
 369          * to cope with writespace callbacks arriving _after_ we have
 370          * called sendmsg(). */
 371         while (1) {
 372                 req->rq_xtime = jiffies;
 373                 status = xs_sendpages(xprt->sock, NULL, 0, xdr,
 374                                                 req->rq_bytes_sent);
 375
 376                 dprintk("RPC:      xs_tcp_send_request(%u) = %d\n",
 377                                 xdr->len - req->rq_bytes_sent, status);
 378
 379                 if (unlikely(status < 0))
 380                         break;
 381
 382                 /* If we've sent the entire packet, immediately
 383                  * reset the count of bytes sent. */
 384                 req->rq_bytes_sent += status;
 385                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 386                         req->rq_bytes_sent = 0;
 387                         return 0;
 388                 }
 389
 390                 status = -EAGAIN;
 391                 if (retry++ > XS_SENDMSG_RETRY)
 392                         break;
 393         }
 394
 395         switch (status) {
 396         case -EAGAIN:
 397                 xs_nospace(task);
 398                 break;
 399         case -ECONNREFUSED:
 400         case -ECONNRESET:
 401         case -ENOTCONN:
 402         case -EPIPE:
 403                 status = -ENOTCONN;
 404                 break;
 405         default:
 406                 dprintk("RPC:      sendmsg returned unrecognized error %d\n",
 407                         -status);
 408                 xprt_disconnect(xprt);
 409                 break;
 410         }
 411
 412         return status;
 413 }
 414
 415 /**
 416  * xs_close - close a socket
 417  * @xprt: transport
 418  *
 419  * This is used when all requests are complete; ie, no DRC state remains
 420  * on the server we want to save.
 421  */
 422 static void xs_close(struct rpc_xprt *xprt)
 423 {
 424         struct socket *sock = xprt->sock;
 425         struct sock *sk = xprt->inet;
 426
 427         if (!sk)
 428                 goto clear_close_wait;
 429
 430         dprintk("RPC:      xs_close xprt %p\n", xprt);
 431
 432         write_lock_bh(&sk->sk_callback_lock);
 433         xprt->inet = NULL;
 434         xprt->sock = NULL;
 435
 436         sk->sk_user_data = NULL;
 437         sk->sk_data_ready = xprt->old_data_ready;
 438         sk->sk_state_change = xprt->old_state_change;
 439         sk->sk_write_space = xprt->old_write_space;
 440         write_unlock_bh(&sk->sk_callback_lock);
 441
 442         sk->sk_no_check = 0;
 443
 444         sock_release(sock);
 445 clear_close_wait:
 446         smp_mb__before_clear_bit();
 447         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
 448         smp_mb__after_clear_bit();
 449 }
 450
 451 /**
 452  * xs_destroy - prepare to shutdown a transport
 453  * @xprt: doomed transport
 454  *
 455  */
 456 static void xs_destroy(struct rpc_xprt *xprt)
 457 {
 458         dprintk("RPC:      xs_destroy xprt %p\n", xprt);
 459
 460         cancel_delayed_work(&xprt->connect_worker);
 461         flush_scheduled_work();
 462
 463         xprt_disconnect(xprt);
 464         xs_close(xprt);
 465         kfree(xprt->slot);
 466 }
 467
 468 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
 469 {
 470         return (struct rpc_xprt *) sk->sk_user_data;
 471 }
 472
 473 /**
 474  * xs_udp_data_ready - "data ready" callback for UDP sockets
 475  * @sk: socket with data to read
 476  * @len: how much data to read
 477  *
 478  */
 479 static void xs_udp_data_ready(struct sock *sk, int len)
 480 {
 481         struct rpc_task *task;
 482         struct rpc_xprt *xprt;
 483         struct rpc_rqst *rovr;
 484         struct sk_buff *skb;
 485         int err, repsize, copied;
 486         u32 _xid, *xp;
 487
 488         read_lock(&sk->sk_callback_lock);
 489         dprintk("RPC:      xs_udp_data_ready...\n");
 490         if (!(xprt = xprt_from_sock(sk)))
 491                 goto out;
 492
 493         if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
 494                 goto out;
 495
 496         if (xprt->shutdown)
 497                 goto dropit;
 498
 499         repsize = skb->len - sizeof(struct udphdr);
 500         if (repsize < 4) {
 501                 dprintk("RPC:      impossible RPC reply size %d!\n", repsize);
 502                 goto dropit;
 503         }
 504
 505         /* Copy the XID from the skb... */
 506         xp = skb_header_pointer(skb, sizeof(struct udphdr),
 507                                 sizeof(_xid), &_xid);
 508         if (xp == NULL)
 509                 goto dropit;
 510
 511         /* Look up and lock the request corresponding to the given XID */
 512         spin_lock(&xprt->transport_lock);
 513         rovr = xprt_lookup_rqst(xprt, *xp);
 514         if (!rovr)
 515                 goto out_unlock;
 516         task = rovr->rq_task;
 517
 518         if ((copied = rovr->rq_private_buf.buflen) > repsize)
 519                 copied = repsize;
 520
 521         /* Suck it into the iovec, verify checksum if not done by hw. */
 522         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb))
 523                 goto out_unlock;
 524
 525         /* Something worked... */
 526         dst_confirm(skb->dst);
 527
 528         xprt_adjust_cwnd(task, copied);
 529         xprt_update_rtt(task);
 530         xprt_complete_rqst(task, copied);
 531
 532  out_unlock:
 533         spin_unlock(&xprt->transport_lock);
 534  dropit:
 535         skb_free_datagram(sk, skb);
 536  out:
 537         read_unlock(&sk->sk_callback_lock);
 538 }
 539
 540 static inline size_t xs_tcp_copy_data(skb_reader_t *desc, void *p, size_t len)
 541 {
 542         if (len > desc->count)
 543                 len = desc->count;
 544         if (skb_copy_bits(desc->skb, desc->offset, p, len)) {
 545                 dprintk("RPC:      failed to copy %zu bytes from skb. %zu bytes remain\n",
 546                                 len, desc->count);
 547                 return 0;
 548         }
 549         desc->offset += len;
 550         desc->count -= len;
 551         dprintk("RPC:      copied %zu bytes from skb. %zu bytes remain\n",
 552                         len, desc->count);
 553         return len;
 554 }
 555
 556 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc)
 557 {
 558         size_t len, used;
 559         char *p;
 560
 561         p = ((char *) &xprt->tcp_recm) + xprt->tcp_offset;
 562         len = sizeof(xprt->tcp_recm) - xprt->tcp_offset;
 563         used = xs_tcp_copy_data(desc, p, len);
 564         xprt->tcp_offset += used;
 565         if (used != len)
 566                 return;
 567
 568         xprt->tcp_reclen = ntohl(xprt->tcp_recm);
 569         if (xprt->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
 570                 xprt->tcp_flags |= XPRT_LAST_FRAG;
 571         else
 572                 xprt->tcp_flags &= ~XPRT_LAST_FRAG;
 573         xprt->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
 574
 575         xprt->tcp_flags &= ~XPRT_COPY_RECM;
 576         xprt->tcp_offset = 0;
 577
 578         /* Sanity check of the record length */
 579         if (unlikely(xprt->tcp_reclen < 4)) {
 580                 dprintk("RPC:      invalid TCP record fragment length\n");
 581                 xprt_disconnect(xprt);
 582                 return;
 583         }
 584         dprintk("RPC:      reading TCP record fragment of length %d\n",
 585                         xprt->tcp_reclen);
 586 }
 587
 588 static void xs_tcp_check_recm(struct rpc_xprt *xprt)
 589 {
 590         dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u, tcp_flags = %lx\n",
 591                         xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen, xprt->tcp_flags);
 592         if (xprt->tcp_offset == xprt->tcp_reclen) {
 593                 xprt->tcp_flags |= XPRT_COPY_RECM;
 594                 xprt->tcp_offset = 0;
 595                 if (xprt->tcp_flags & XPRT_LAST_FRAG) {
 596                         xprt->tcp_flags &= ~XPRT_COPY_DATA;
 597                         xprt->tcp_flags |= XPRT_COPY_XID;
 598                         xprt->tcp_copied = 0;
 599                 }
 600         }
 601 }
 602
 603 static inline void xs_tcp_read_xid(struct rpc_xprt *xprt, skb_reader_t *desc)
 604 {
 605         size_t len, used;
 606         char *p;
 607
 608         len = sizeof(xprt->tcp_xid) - xprt->tcp_offset;
 609         dprintk("RPC:      reading XID (%Zu bytes)\n", len);
 610         p = ((char *) &xprt->tcp_xid) + xprt->tcp_offset;
 611         used = xs_tcp_copy_data(desc, p, len);
 612         xprt->tcp_offset += used;
 613         if (used != len)
 614                 return;
 615         xprt->tcp_flags &= ~XPRT_COPY_XID;
 616         xprt->tcp_flags |= XPRT_COPY_DATA;
 617         xprt->tcp_copied = 4;
 618         dprintk("RPC:      reading reply for XID %08x\n",
 619                                                 ntohl(xprt->tcp_xid));
 620         xs_tcp_check_recm(xprt);
 621 }
 622
 623 static inline void xs_tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
 624 {
 625         struct rpc_rqst *req;
 626         struct xdr_buf *rcvbuf;
 627         size_t len;
 628         ssize_t r;
 629
 630         /* Find and lock the request corresponding to this xid */
 631         spin_lock(&xprt->transport_lock);
 632         req = xprt_lookup_rqst(xprt, xprt->tcp_xid);
 633         if (!req) {
 634                 xprt->tcp_flags &= ~XPRT_COPY_DATA;
 635                 dprintk("RPC:      XID %08x request not found!\n",
 636                                 ntohl(xprt->tcp_xid));
 637                 spin_unlock(&xprt->transport_lock);
 638                 return;
 639         }
 640
 641         rcvbuf = &req->rq_private_buf;
 642         len = desc->count;
 643         if (len > xprt->tcp_reclen - xprt->tcp_offset) {
 644                 skb_reader_t my_desc;
 645
 646                 len = xprt->tcp_reclen - xprt->tcp_offset;
 647                 memcpy(&my_desc, desc, sizeof(my_desc));
 648                 my_desc.count = len;
 649                 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
 650                                           &my_desc, xs_tcp_copy_data);
 651                 desc->count -= r;
 652                 desc->offset += r;
 653         } else
 654                 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
 655                                           desc, xs_tcp_copy_data);
 656
 657         if (r > 0) {
 658                 xprt->tcp_copied += r;
 659                 xprt->tcp_offset += r;
 660         }
 661         if (r != len) {
 662                 /* Error when copying to the receive buffer,
 663                  * usually because we weren't able to allocate
 664                  * additional buffer pages. All we can do now
 665                  * is turn off XPRT_COPY_DATA, so the request
 666                  * will not receive any additional updates,
 667                  * and time out.
 668                  * Any remaining data from this record will
 669                  * be discarded.
 670                  */
 671                 xprt->tcp_flags &= ~XPRT_COPY_DATA;
 672                 dprintk("RPC:      XID %08x truncated request\n",
 673                                 ntohl(xprt->tcp_xid));
 674                 dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
 675                                 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
 676                 goto out;
 677         }
 678
 679         dprintk("RPC:      XID %08x read %Zd bytes\n",
 680                         ntohl(xprt->tcp_xid), r);
 681         dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
 682                         xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
 683
 684         if (xprt->tcp_copied == req->rq_private_buf.buflen)
 685                 xprt->tcp_flags &= ~XPRT_COPY_DATA;
 686         else if (xprt->tcp_offset == xprt->tcp_reclen) {
 687                 if (xprt->tcp_flags & XPRT_LAST_FRAG)
 688                         xprt->tcp_flags &= ~XPRT_COPY_DATA;
 689         }
 690
 691 out:
 692         if (!(xprt->tcp_flags & XPRT_COPY_DATA))
 693                 xprt_complete_rqst(req->rq_task, xprt->tcp_copied);
 694         spin_unlock(&xprt->transport_lock);
 695         xs_tcp_check_recm(xprt);
 696 }
 697
 698 static inline void xs_tcp_read_discard(struct rpc_xprt *xprt, skb_reader_t *desc)
 699 {
 700         size_t len;
 701
 702         len = xprt->tcp_reclen - xprt->tcp_offset;
 703         if (len > desc->count)
 704                 len = desc->count;
 705         desc->count -= len;
 706         desc->offset += len;
 707         xprt->tcp_offset += len;
 708         dprintk("RPC:      discarded %Zu bytes\n", len);
 709         xs_tcp_check_recm(xprt);
 710 }
 711
 712 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
 713 {
 714         struct rpc_xprt *xprt = rd_desc->arg.data;
 715         skb_reader_t desc = {
 716                 .skb    = skb,
 717                 .offset = offset,
 718                 .count  = len,
 719                 .csum   = 0
 720         };
 721
 722         dprintk("RPC:      xs_tcp_data_recv started\n");
 723         do {
 724                 /* Read in a new fragment marker if necessary */
 725                 /* Can we ever really expect to get completely empty fragments? */
 726                 if (xprt->tcp_flags & XPRT_COPY_RECM) {
 727                         xs_tcp_read_fraghdr(xprt, &desc);
 728                         continue;
 729                 }
 730                 /* Read in the xid if necessary */
 731                 if (xprt->tcp_flags & XPRT_COPY_XID) {
 732                         xs_tcp_read_xid(xprt, &desc);
 733                         continue;
 734                 }
 735                 /* Read in the request data */
 736                 if (xprt->tcp_flags & XPRT_COPY_DATA) {
 737                         xs_tcp_read_request(xprt, &desc);
 738                         continue;
 739                 }
 740                 /* Skip over any trailing bytes on short reads */
 741                 xs_tcp_read_discard(xprt, &desc);
 742         } while (desc.count);
 743         dprintk("RPC:      xs_tcp_data_recv done\n");
 744         return len - desc.count;
 745 }
 746
 747 /**
 748  * xs_tcp_data_ready - "data ready" callback for TCP sockets
 749  * @sk: socket with data to read
 750  * @bytes: how much data to read
 751  *
 752  */
 753 static void xs_tcp_data_ready(struct sock *sk, int bytes)
 754 {
 755         struct rpc_xprt *xprt;
 756         read_descriptor_t rd_desc;
 757
 758         read_lock(&sk->sk_callback_lock);
 759         dprintk("RPC:      xs_tcp_data_ready...\n");
 760         if (!(xprt = xprt_from_sock(sk)))
 761                 goto out;
 762         if (xprt->shutdown)
 763                 goto out;
 764
 765         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
 766         rd_desc.arg.data = xprt;
 767         rd_desc.count = 65536;
 768         tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
 769 out:
 770         read_unlock(&sk->sk_callback_lock);
 771 }
 772
 773 /**
 774  * xs_tcp_state_change - callback to handle TCP socket state changes
 775  * @sk: socket whose state has changed
 776  *
 777  */
 778 static void xs_tcp_state_change(struct sock *sk)
 779 {
 780         struct rpc_xprt *xprt;
 781
 782         read_lock(&sk->sk_callback_lock);
 783         if (!(xprt = xprt_from_sock(sk)))
 784                 goto out;
 785         dprintk("RPC:      xs_tcp_state_change client %p...\n", xprt);
 786         dprintk("RPC:      state %x conn %d dead %d zapped %d\n",
 787                                 sk->sk_state, xprt_connected(xprt),
 788                                 sock_flag(sk, SOCK_DEAD),
 789                                 sock_flag(sk, SOCK_ZAPPED));
 790
 791         switch (sk->sk_state) {
 792         case TCP_ESTABLISHED:
 793                 spin_lock_bh(&xprt->transport_lock);
 794                 if (!xprt_test_and_set_connected(xprt)) {
 795                         /* Reset TCP record info */
 796                         xprt->tcp_offset = 0;
 797                         xprt->tcp_reclen = 0;
 798                         xprt->tcp_copied = 0;
 799                         xprt->tcp_flags = XPRT_COPY_RECM | XPRT_COPY_XID;
 800                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
 801                         xprt_wake_pending_tasks(xprt, 0);
 802                 }
 803                 spin_unlock_bh(&xprt->transport_lock);
 804                 break;
 805         case TCP_SYN_SENT:
 806         case TCP_SYN_RECV:
 807                 break;
 808         case TCP_CLOSE_WAIT:
 809                 /* Try to schedule an autoclose RPC calls */
 810                 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
 811                 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
 812                         schedule_work(&xprt->task_cleanup);
 813         default:
 814                 xprt_disconnect(xprt);
 815         }
 816  out:
 817         read_unlock(&sk->sk_callback_lock);
 818 }
 819
 820 /**
 821  * xs_udp_write_space - callback invoked when socket buffer space
 822  *                             becomes available
 823  * @sk: socket whose state has changed
 824  *
 825  * Called when more output buffer space is available for this socket.
 826  * We try not to wake our writers until they can make "significant"
 827  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
 828  * with a bunch of small requests.
 829  */
 830 static void xs_udp_write_space(struct sock *sk)
 831 {
 832         read_lock(&sk->sk_callback_lock);
 833
 834         /* from net/core/sock.c:sock_def_write_space */
 835         if (sock_writeable(sk)) {
 836                 struct socket *sock;
 837                 struct rpc_xprt *xprt;
 838
 839                 if (unlikely(!(sock = sk->sk_socket)))
 840                         goto out;
 841                 if (unlikely(!(xprt = xprt_from_sock(sk))))
 842                         goto out;
 843                 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
 844                         goto out;
 845
 846                 xprt_write_space(xprt);
 847         }
 848
 849  out:
 850         read_unlock(&sk->sk_callback_lock);
 851 }
 852
 853 /**
 854  * xs_tcp_write_space - callback invoked when socket buffer space
 855  *                             becomes available
 856  * @sk: socket whose state has changed
 857  *
 858  * Called when more output buffer space is available for this socket.
 859  * We try not to wake our writers until they can make "significant"
 860  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
 861  * with a bunch of small requests.
 862  */
 863 static void xs_tcp_write_space(struct sock *sk)
 864 {
 865         read_lock(&sk->sk_callback_lock);
 866
 867         /* from net/core/stream.c:sk_stream_write_space */
 868         if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
 869                 struct socket *sock;
 870                 struct rpc_xprt *xprt;
 871
 872                 if (unlikely(!(sock = sk->sk_socket)))
 873                         goto out;
 874                 if (unlikely(!(xprt = xprt_from_sock(sk))))
 875                         goto out;
 876                 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
 877                         goto out;
 878
 879                 xprt_write_space(xprt);
 880         }
 881
 882  out:
 883         read_unlock(&sk->sk_callback_lock);
 884 }
 885
 886 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
 887 {
 888         struct sock *sk = xprt->inet;
 889
 890         if (xprt->rcvsize) {
 891                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
 892                 sk->sk_rcvbuf = xprt->rcvsize * xprt->max_reqs *  2;
 893         }
 894         if (xprt->sndsize) {
 895                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
 896                 sk->sk_sndbuf = xprt->sndsize * xprt->max_reqs * 2;
 897                 sk->sk_write_space(sk);
 898         }
 899 }
 900
 901 /**
 902  * xs_udp_set_buffer_size - set send and receive limits
 903  * @xprt: generic transport
 904  * @sndsize: requested size of send buffer, in bytes
 905  * @rcvsize: requested size of receive buffer, in bytes
 906  *
 907  * Set socket send and receive buffer size limits.
 908  */
 909 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
 910 {
 911         xprt->sndsize = 0;
 912         if (sndsize)
 913                 xprt->sndsize = sndsize + 1024;
 914         xprt->rcvsize = 0;
 915         if (rcvsize)
 916                 xprt->rcvsize = rcvsize + 1024;
 917
 918         xs_udp_do_set_buffer_size(xprt);
 919 }
 920
 921 /**
 922  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
 923  * @task: task that timed out
 924  *
 925  * Adjust the congestion window after a retransmit timeout has occurred.
 926  */
 927 static void xs_udp_timer(struct rpc_task *task)
 928 {
 929         xprt_adjust_cwnd(task, -ETIMEDOUT);
 930 }
 931
 932 /**
 933  * xs_set_port - reset the port number in the remote endpoint address
 934  * @xprt: generic transport
 935  * @port: new port number
 936  *
 937  */
 938 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
 939 {
 940         dprintk("RPC:      setting port for xprt %p to %u\n", xprt, port);
 941         xprt->addr.sin_port = htons(port);
 942 }
 943
 944 static int xs_bindresvport(struct rpc_xprt *xprt, struct socket *sock)
 945 {
 946         struct sockaddr_in myaddr = {
 947                 .sin_family = AF_INET,
 948         };
 949         int err;
 950         unsigned short port = xprt->port;
 951
 952         do {
 953                 myaddr.sin_port = htons(port);
 954                 err = sock->ops->bind(sock, (struct sockaddr *) &myaddr,
 955                                                 sizeof(myaddr));
 956                 if (err == 0) {
 957                         xprt->port = port;
 958                         dprintk("RPC:      xs_bindresvport bound to port %u\n",
 959                                         port);
 960                         return 0;
 961                 }
 962                 if (port <= xprt_min_resvport)
 963                         port = xprt_max_resvport;
 964                 else
 965                         port--;
 966         } while (err == -EADDRINUSE && port != xprt->port);
 967
 968         dprintk("RPC:      can't bind to reserved port (%d).\n", -err);
 969         return err;
 970 }
 971
 972 /**
 973  * xs_udp_connect_worker - set up a UDP socket
 974  * @args: RPC transport to connect
 975  *
 976  * Invoked by a work queue tasklet.
 977  */
 978 static void xs_udp_connect_worker(void *args)
 979 {
 980         struct rpc_xprt *xprt = (struct rpc_xprt *) args;
 981         struct socket *sock = xprt->sock;
 982         int err, status = -EIO;
 983
 984         if (xprt->shutdown || xprt->addr.sin_port == 0)
 985                 goto out;
 986
 987         dprintk("RPC:      xs_udp_connect_worker for xprt %p\n", xprt);
 988
 989         /* Start by resetting any existing state */
 990         xs_close(xprt);
 991
 992         if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
 993                 dprintk("RPC:      can't create UDP transport socket (%d).\n", -err);
 994                 goto out;
 995         }
 996
 997         if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
 998                 sock_release(sock);
 999                 goto out;
1000         }
1001
1002         if (!xprt->inet) {
1003                 struct sock *sk = sock->sk;
1004
1005                 write_lock_bh(&sk->sk_callback_lock);
1006
1007                 sk->sk_user_data = xprt;
1008                 xprt->old_data_ready = sk->sk_data_ready;
1009                 xprt->old_state_change = sk->sk_state_change;
1010                 xprt->old_write_space = sk->sk_write_space;
1011                 sk->sk_data_ready = xs_udp_data_ready;
1012                 sk->sk_write_space = xs_udp_write_space;
1013                 sk->sk_no_check = UDP_CSUM_NORCV;
1014                 sk->sk_allocation = GFP_ATOMIC;
1015
1016                 xprt_set_connected(xprt);
1017
1018                 /* Reset to new socket */
1019                 xprt->sock = sock;
1020                 xprt->inet = sk;
1021
1022                 write_unlock_bh(&sk->sk_callback_lock);
1023         }
1024         xs_udp_do_set_buffer_size(xprt);
1025         status = 0;
1026 out:
1027         xprt_wake_pending_tasks(xprt, status);
1028         xprt_clear_connecting(xprt);
1029 }
1030
1031 /*
1032  * We need to preserve the port number so the reply cache on the server can
1033  * find our cached RPC replies when we get around to reconnecting.
1034  */
1035 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
1036 {
1037         int result;
1038         struct socket *sock = xprt->sock;
1039         struct sockaddr any;
1040
1041         dprintk("RPC:      disconnecting xprt %p to reuse port\n", xprt);
1042
1043         /*
1044          * Disconnect the transport socket by doing a connect operation
1045          * with AF_UNSPEC.  This should return immediately...
1046          */
1047         memset(&any, 0, sizeof(any));
1048         any.sa_family = AF_UNSPEC;
1049         result = sock->ops->connect(sock, &any, sizeof(any), 0);
1050         if (result)
1051                 dprintk("RPC:      AF_UNSPEC connect return code %d\n",
1052                                 result);
1053 }
1054
1055 /**
1056  * xs_tcp_connect_worker - connect a TCP socket to a remote endpoint
1057  * @args: RPC transport to connect
1058  *
1059  * Invoked by a work queue tasklet.
1060  */
1061 static void xs_tcp_connect_worker(void *args)
1062 {
1063         struct rpc_xprt *xprt = (struct rpc_xprt *)args;
1064         struct socket *sock = xprt->sock;
1065         int err, status = -EIO;
1066
1067         if (xprt->shutdown || xprt->addr.sin_port == 0)
1068                 goto out;
1069
1070         dprintk("RPC:      xs_tcp_connect_worker for xprt %p\n", xprt);
1071
1072         if (!xprt->sock) {
1073                 /* start from scratch */
1074                 if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1075                         dprintk("RPC:      can't create TCP transport socket (%d).\n", -err);
1076                         goto out;
1077                 }
1078
1079                 if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
1080                         sock_release(sock);
1081                         goto out;
1082                 }
1083         } else
1084                 /* "close" the socket, preserving the local port */
1085                 xs_tcp_reuse_connection(xprt);
1086
1087         if (!xprt->inet) {
1088                 struct sock *sk = sock->sk;
1089
1090                 write_lock_bh(&sk->sk_callback_lock);
1091
1092                 sk->sk_user_data = xprt;
1093                 xprt->old_data_ready = sk->sk_data_ready;
1094                 xprt->old_state_change = sk->sk_state_change;
1095                 xprt->old_write_space = sk->sk_write_space;
1096                 sk->sk_data_ready = xs_tcp_data_ready;
1097                 sk->sk_state_change = xs_tcp_state_change;
1098                 sk->sk_write_space = xs_tcp_write_space;
1099                 sk->sk_allocation = GFP_ATOMIC;
1100
1101                 /* socket options */
1102                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1103                 sock_reset_flag(sk, SOCK_LINGER);
1104                 tcp_sk(sk)->linger2 = 0;
1105                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1106
1107                 xprt_clear_connected(xprt);
1108
1109                 /* Reset to new socket */
1110                 xprt->sock = sock;
1111                 xprt->inet = sk;
1112
1113                 write_unlock_bh(&sk->sk_callback_lock);
1114         }
1115
1116         /* Tell the socket layer to start connecting... */
1117         status = sock->ops->connect(sock, (struct sockaddr *) &xprt->addr,
1118                         sizeof(xprt->addr), O_NONBLOCK);
1119         dprintk("RPC: %p  connect status %d connected %d sock state %d\n",
1120                         xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
1121         if (status < 0) {
1122                 switch (status) {
1123                         case -EINPROGRESS:
1124                         case -EALREADY:
1125                                 goto out_clear;
1126                         case -ECONNREFUSED:
1127                         case -ECONNRESET:
1128                                 /* retry with existing socket, after a delay */
1129                                 break;
1130                         default:
1131                                 /* get rid of existing socket, and retry */
1132                                 xs_close(xprt);
1133                                 break;
1134                 }
1135         }
1136 out:
1137         xprt_wake_pending_tasks(xprt, status);
1138 out_clear:
1139         xprt_clear_connecting(xprt);
1140 }
1141
1142 /**
1143  * xs_connect - connect a socket to a remote endpoint
1144  * @task: address of RPC task that manages state of connect request
1145  *
1146  * TCP: If the remote end dropped the connection, delay reconnecting.
1147  *
1148  * UDP socket connects are synchronous, but we use a work queue anyway
1149  * to guarantee that even unprivileged user processes can set up a
1150  * socket on a privileged port.
1151  *
1152  * If a UDP socket connect fails, the delay behavior here prevents
1153  * retry floods (hard mounts).
1154  */
1155 static void xs_connect(struct rpc_task *task)
1156 {
1157         struct rpc_xprt *xprt = task->tk_xprt;
1158
1159         if (xprt_test_and_set_connecting(xprt))
1160                 return;
1161
1162         if (xprt->sock != NULL) {
1163                 dprintk("RPC:      xs_connect delayed xprt %p for %lu seconds\n",
1164                                 xprt, xprt->reestablish_timeout / HZ);
1165                 schedule_delayed_work(&xprt->connect_worker,
1166                                         xprt->reestablish_timeout);
1167                 xprt->reestablish_timeout <<= 1;
1168                 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
1169                         xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
1170         } else {
1171                 dprintk("RPC:      xs_connect scheduled xprt %p\n", xprt);
1172                 schedule_work(&xprt->connect_worker);
1173
1174                 /* flush_scheduled_work can sleep... */
1175                 if (!RPC_IS_ASYNC(task))
1176                         flush_scheduled_work();
1177         }
1178 }
1179
1180 static struct rpc_xprt_ops xs_udp_ops = {
1181         .set_buffer_size        = xs_udp_set_buffer_size,
1182         .reserve_xprt           = xprt_reserve_xprt_cong,
1183         .release_xprt           = xprt_release_xprt_cong,
1184         .set_port               = xs_set_port,
1185         .connect                = xs_connect,
1186         .buf_alloc              = rpc_malloc,
1187         .buf_free               = rpc_free,
1188         .send_request           = xs_udp_send_request,
1189         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
1190         .timer                  = xs_udp_timer,
1191         .release_request        = xprt_release_rqst_cong,
1192         .close                  = xs_close,
1193         .destroy                = xs_destroy,
1194 };
1195
1196 static struct rpc_xprt_ops xs_tcp_ops = {
1197         .reserve_xprt           = xprt_reserve_xprt,
1198         .release_xprt           = xprt_release_xprt,
1199         .set_port               = xs_set_port,
1200         .connect                = xs_connect,
1201         .buf_alloc              = rpc_malloc,
1202         .buf_free               = rpc_free,
1203         .send_request           = xs_tcp_send_request,
1204         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
1205         .close                  = xs_close,
1206         .destroy                = xs_destroy,
1207 };
1208
1209 /**
1210  * xs_setup_udp - Set up transport to use a UDP socket
1211  * @xprt: transport to set up
1212  * @to:   timeout parameters
1213  *
1214  */
1215 int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to)
1216 {
1217         size_t slot_table_size;
1218
1219         dprintk("RPC:      setting up udp-ipv4 transport...\n");
1220
1221         xprt->max_reqs = xprt_udp_slot_table_entries;
1222         slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
1223         xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
1224         if (xprt->slot == NULL)
1225                 return -ENOMEM;
1226         memset(xprt->slot, 0, slot_table_size);
1227
1228         xprt->prot = IPPROTO_UDP;
1229         xprt->port = xprt_max_resvport;
1230         xprt->tsh_size = 0;
1231         xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
1232         /* XXX: header size can vary due to auth type, IPv6, etc. */
1233         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
1234
1235         INIT_WORK(&xprt->connect_worker, xs_udp_connect_worker, xprt);
1236         xprt->bind_timeout = XS_BIND_TO;
1237         xprt->connect_timeout = XS_UDP_CONN_TO;
1238         xprt->reestablish_timeout = XS_UDP_REEST_TO;
1239         xprt->idle_timeout = XS_IDLE_DISC_TO;
1240
1241         xprt->ops = &xs_udp_ops;
1242
1243         if (to)
1244                 xprt->timeout = *to;
1245         else
1246                 xprt_set_timeout(&xprt->timeout, 5, 5 * HZ);
1247
1248         return 0;
1249 }
1250
1251 /**
1252  * xs_setup_tcp - Set up transport to use a TCP socket
1253  * @xprt: transport to set up
1254  * @to: timeout parameters
1255  *
1256  */
1257 int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to)
1258 {
1259         size_t slot_table_size;
1260
1261         dprintk("RPC:      setting up tcp-ipv4 transport...\n");
1262
1263         xprt->max_reqs = xprt_tcp_slot_table_entries;
1264         slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
1265         xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
1266         if (xprt->slot == NULL)
1267                 return -ENOMEM;
1268         memset(xprt->slot, 0, slot_table_size);
1269
1270         xprt->prot = IPPROTO_TCP;
1271         xprt->port = xprt_max_resvport;
1272         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
1273         xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
1274         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
1275
1276         INIT_WORK(&xprt->connect_worker, xs_tcp_connect_worker, xprt);
1277         xprt->bind_timeout = XS_BIND_TO;
1278         xprt->connect_timeout = XS_TCP_CONN_TO;
1279         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1280         xprt->idle_timeout = XS_IDLE_DISC_TO;
1281
1282         xprt->ops = &xs_tcp_ops;
1283
1284         if (to)
1285                 xprt->timeout = *to;
1286         else
1287                 xprt_set_timeout(&xprt->timeout, 2, 60 * HZ);
1288
1289         return 0;
1290 }