git.oblomov.eu Git - linux-2.6/blob - 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                 task->tk_bytes_sent += status;
 386                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 387                         req->rq_bytes_sent = 0;
 388                         return 0;
 389                 }
 390
 391                 status = -EAGAIN;
 392                 if (retry++ > XS_SENDMSG_RETRY)
 393                         break;
 394         }
 395
 396         switch (status) {
 397         case -EAGAIN:
 398                 xs_nospace(task);
 399                 break;
 400         case -ECONNREFUSED:
 401         case -ECONNRESET:
 402         case -ENOTCONN:
 403         case -EPIPE:
 404                 status = -ENOTCONN;
 405                 break;
 406         default:
 407                 dprintk("RPC:      sendmsg returned unrecognized error %d\n",
 408                         -status);
 409                 xprt_disconnect(xprt);
 410                 break;
 411         }
 412
 413         return status;
 414 }
 415
 416 /**
 417  * xs_close - close a socket
 418  * @xprt: transport
 419  *
 420  * This is used when all requests are complete; ie, no DRC state remains
 421  * on the server we want to save.
 422  */
 423 static void xs_close(struct rpc_xprt *xprt)
 424 {
 425         struct socket *sock = xprt->sock;
 426         struct sock *sk = xprt->inet;
 427
 428         if (!sk)
 429                 goto clear_close_wait;
 430
 431         dprintk("RPC:      xs_close xprt %p\n", xprt);
 432
 433         write_lock_bh(&sk->sk_callback_lock);
 434         xprt->inet = NULL;
 435         xprt->sock = NULL;
 436
 437         sk->sk_user_data = NULL;
 438         sk->sk_data_ready = xprt->old_data_ready;
 439         sk->sk_state_change = xprt->old_state_change;
 440         sk->sk_write_space = xprt->old_write_space;
 441         write_unlock_bh(&sk->sk_callback_lock);
 442
 443         sk->sk_no_check = 0;
 444
 445         sock_release(sock);
 446 clear_close_wait:
 447         smp_mb__before_clear_bit();
 448         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
 449         smp_mb__after_clear_bit();
 450 }
 451
 452 /**
 453  * xs_destroy - prepare to shutdown a transport
 454  * @xprt: doomed transport
 455  *
 456  */
 457 static void xs_destroy(struct rpc_xprt *xprt)
 458 {
 459         dprintk("RPC:      xs_destroy xprt %p\n", xprt);
 460
 461         cancel_delayed_work(&xprt->connect_worker);
 462         flush_scheduled_work();
 463
 464         xprt_disconnect(xprt);
 465         xs_close(xprt);
 466         kfree(xprt->slot);
 467 }
 468
 469 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
 470 {
 471         return (struct rpc_xprt *) sk->sk_user_data;
 472 }
 473
 474 /**
 475  * xs_udp_data_ready - "data ready" callback for UDP sockets
 476  * @sk: socket with data to read
 477  * @len: how much data to read
 478  *
 479  */
 480 static void xs_udp_data_ready(struct sock *sk, int len)
 481 {
 482         struct rpc_task *task;
 483         struct rpc_xprt *xprt;
 484         struct rpc_rqst *rovr;
 485         struct sk_buff *skb;
 486         int err, repsize, copied;
 487         u32 _xid, *xp;
 488
 489         read_lock(&sk->sk_callback_lock);
 490         dprintk("RPC:      xs_udp_data_ready...\n");
 491         if (!(xprt = xprt_from_sock(sk)))
 492                 goto out;
 493
 494         if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
 495                 goto out;
 496
 497         if (xprt->shutdown)
 498                 goto dropit;
 499
 500         repsize = skb->len - sizeof(struct udphdr);
 501         if (repsize < 4) {
 502                 dprintk("RPC:      impossible RPC reply size %d!\n", repsize);
 503                 goto dropit;
 504         }
 505
 506         /* Copy the XID from the skb... */
 507         xp = skb_header_pointer(skb, sizeof(struct udphdr),
 508                                 sizeof(_xid), &_xid);
 509         if (xp == NULL)
 510                 goto dropit;
 511
 512         /* Look up and lock the request corresponding to the given XID */
 513         spin_lock(&xprt->transport_lock);
 514         rovr = xprt_lookup_rqst(xprt, *xp);
 515         if (!rovr)
 516                 goto out_unlock;
 517         task = rovr->rq_task;
 518
 519         if ((copied = rovr->rq_private_buf.buflen) > repsize)
 520                 copied = repsize;
 521
 522         /* Suck it into the iovec, verify checksum if not done by hw. */
 523         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb))
 524                 goto out_unlock;
 525
 526         /* Something worked... */
 527         dst_confirm(skb->dst);
 528
 529         xprt_adjust_cwnd(task, copied);
 530         xprt_update_rtt(task);
 531         xprt_complete_rqst(task, copied);
 532
 533  out_unlock:
 534         spin_unlock(&xprt->transport_lock);
 535  dropit:
 536         skb_free_datagram(sk, skb);
 537  out:
 538         read_unlock(&sk->sk_callback_lock);
 539 }
 540
 541 static inline size_t xs_tcp_copy_data(skb_reader_t *desc, void *p, size_t len)
 542 {
 543         if (len > desc->count)
 544                 len = desc->count;
 545         if (skb_copy_bits(desc->skb, desc->offset, p, len)) {
 546                 dprintk("RPC:      failed to copy %zu bytes from skb. %zu bytes remain\n",
 547                                 len, desc->count);
 548                 return 0;
 549         }
 550         desc->offset += len;
 551         desc->count -= len;
 552         dprintk("RPC:      copied %zu bytes from skb. %zu bytes remain\n",
 553                         len, desc->count);
 554         return len;
 555 }
 556
 557 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc)
 558 {
 559         size_t len, used;
 560         char *p;
 561
 562         p = ((char *) &xprt->tcp_recm) + xprt->tcp_offset;
 563         len = sizeof(xprt->tcp_recm) - xprt->tcp_offset;
 564         used = xs_tcp_copy_data(desc, p, len);
 565         xprt->tcp_offset += used;
 566         if (used != len)
 567                 return;
 568
 569         xprt->tcp_reclen = ntohl(xprt->tcp_recm);
 570         if (xprt->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
 571                 xprt->tcp_flags |= XPRT_LAST_FRAG;
 572         else
 573                 xprt->tcp_flags &= ~XPRT_LAST_FRAG;
 574         xprt->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
 575
 576         xprt->tcp_flags &= ~XPRT_COPY_RECM;
 577         xprt->tcp_offset = 0;
 578
 579         /* Sanity check of the record length */
 580         if (unlikely(xprt->tcp_reclen < 4)) {
 581                 dprintk("RPC:      invalid TCP record fragment length\n");
 582                 xprt_disconnect(xprt);
 583                 return;
 584         }
 585         dprintk("RPC:      reading TCP record fragment of length %d\n",
 586                         xprt->tcp_reclen);
 587 }
 588
 589 static void xs_tcp_check_recm(struct rpc_xprt *xprt)
 590 {
 591         dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u, tcp_flags = %lx\n",
 592                         xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen, xprt->tcp_flags);
 593         if (xprt->tcp_offset == xprt->tcp_reclen) {
 594                 xprt->tcp_flags |= XPRT_COPY_RECM;
 595                 xprt->tcp_offset = 0;
 596                 if (xprt->tcp_flags & XPRT_LAST_FRAG) {
 597                         xprt->tcp_flags &= ~XPRT_COPY_DATA;
 598                         xprt->tcp_flags |= XPRT_COPY_XID;
 599                         xprt->tcp_copied = 0;
 600                 }
 601         }
 602 }
 603
 604 static inline void xs_tcp_read_xid(struct rpc_xprt *xprt, skb_reader_t *desc)
 605 {
 606         size_t len, used;
 607         char *p;
 608
 609         len = sizeof(xprt->tcp_xid) - xprt->tcp_offset;
 610         dprintk("RPC:      reading XID (%Zu bytes)\n", len);
 611         p = ((char *) &xprt->tcp_xid) + xprt->tcp_offset;
 612         used = xs_tcp_copy_data(desc, p, len);
 613         xprt->tcp_offset += used;
 614         if (used != len)
 615                 return;
 616         xprt->tcp_flags &= ~XPRT_COPY_XID;
 617         xprt->tcp_flags |= XPRT_COPY_DATA;
 618         xprt->tcp_copied = 4;
 619         dprintk("RPC:      reading reply for XID %08x\n",
 620                                                 ntohl(xprt->tcp_xid));
 621         xs_tcp_check_recm(xprt);
 622 }
 623
 624 static inline void xs_tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
 625 {
 626         struct rpc_rqst *req;
 627         struct xdr_buf *rcvbuf;
 628         size_t len;
 629         ssize_t r;
 630
 631         /* Find and lock the request corresponding to this xid */
 632         spin_lock(&xprt->transport_lock);
 633         req = xprt_lookup_rqst(xprt, xprt->tcp_xid);
 634         if (!req) {
 635                 xprt->tcp_flags &= ~XPRT_COPY_DATA;
 636                 dprintk("RPC:      XID %08x request not found!\n",
 637                                 ntohl(xprt->tcp_xid));
 638                 spin_unlock(&xprt->transport_lock);
 639                 return;
 640         }
 641
 642         rcvbuf = &req->rq_private_buf;
 643         len = desc->count;
 644         if (len > xprt->tcp_reclen - xprt->tcp_offset) {
 645                 skb_reader_t my_desc;
 646
 647                 len = xprt->tcp_reclen - xprt->tcp_offset;
 648                 memcpy(&my_desc, desc, sizeof(my_desc));
 649                 my_desc.count = len;
 650                 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
 651                                           &my_desc, xs_tcp_copy_data);
 652                 desc->count -= r;
 653                 desc->offset += r;
 654         } else
 655                 r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
 656                                           desc, xs_tcp_copy_data);
 657
 658         if (r > 0) {
 659                 xprt->tcp_copied += r;
 660                 xprt->tcp_offset += r;
 661         }
 662         if (r != len) {
 663                 /* Error when copying to the receive buffer,
 664                  * usually because we weren't able to allocate
 665                  * additional buffer pages. All we can do now
 666                  * is turn off XPRT_COPY_DATA, so the request
 667                  * will not receive any additional updates,
 668                  * and time out.
 669                  * Any remaining data from this record will
 670                  * be discarded.
 671                  */
 672                 xprt->tcp_flags &= ~XPRT_COPY_DATA;
 673                 dprintk("RPC:      XID %08x truncated request\n",
 674                                 ntohl(xprt->tcp_xid));
 675                 dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
 676                                 xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
 677                 goto out;
 678         }
 679
 680         dprintk("RPC:      XID %08x read %Zd bytes\n",
 681                         ntohl(xprt->tcp_xid), r);
 682         dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
 683                         xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
 684
 685         if (xprt->tcp_copied == req->rq_private_buf.buflen)
 686                 xprt->tcp_flags &= ~XPRT_COPY_DATA;
 687         else if (xprt->tcp_offset == xprt->tcp_reclen) {
 688                 if (xprt->tcp_flags & XPRT_LAST_FRAG)
 689                         xprt->tcp_flags &= ~XPRT_COPY_DATA;
 690         }
 691
 692 out:
 693         if (!(xprt->tcp_flags & XPRT_COPY_DATA))
 694                 xprt_complete_rqst(req->rq_task, xprt->tcp_copied);
 695         spin_unlock(&xprt->transport_lock);
 696         xs_tcp_check_recm(xprt);
 697 }
 698
 699 static inline void xs_tcp_read_discard(struct rpc_xprt *xprt, skb_reader_t *desc)
 700 {
 701         size_t len;
 702
 703         len = xprt->tcp_reclen - xprt->tcp_offset;
 704         if (len > desc->count)
 705                 len = desc->count;
 706         desc->count -= len;
 707         desc->offset += len;
 708         xprt->tcp_offset += len;
 709         dprintk("RPC:      discarded %Zu bytes\n", len);
 710         xs_tcp_check_recm(xprt);
 711 }
 712
 713 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
 714 {
 715         struct rpc_xprt *xprt = rd_desc->arg.data;
 716         skb_reader_t desc = {
 717                 .skb    = skb,
 718                 .offset = offset,
 719                 .count  = len,
 720                 .csum   = 0
 721         };
 722
 723         dprintk("RPC:      xs_tcp_data_recv started\n");
 724         do {
 725                 /* Read in a new fragment marker if necessary */
 726                 /* Can we ever really expect to get completely empty fragments? */
 727                 if (xprt->tcp_flags & XPRT_COPY_RECM) {
 728                         xs_tcp_read_fraghdr(xprt, &desc);
 729                         continue;
 730                 }
 731                 /* Read in the xid if necessary */
 732                 if (xprt->tcp_flags & XPRT_COPY_XID) {
 733                         xs_tcp_read_xid(xprt, &desc);
 734                         continue;
 735                 }
 736                 /* Read in the request data */
 737                 if (xprt->tcp_flags & XPRT_COPY_DATA) {
 738                         xs_tcp_read_request(xprt, &desc);
 739                         continue;
 740                 }
 741                 /* Skip over any trailing bytes on short reads */
 742                 xs_tcp_read_discard(xprt, &desc);
 743         } while (desc.count);
 744         dprintk("RPC:      xs_tcp_data_recv done\n");
 745         return len - desc.count;
 746 }
 747
 748 /**
 749  * xs_tcp_data_ready - "data ready" callback for TCP sockets
 750  * @sk: socket with data to read
 751  * @bytes: how much data to read
 752  *
 753  */
 754 static void xs_tcp_data_ready(struct sock *sk, int bytes)
 755 {
 756         struct rpc_xprt *xprt;
 757         read_descriptor_t rd_desc;
 758
 759         read_lock(&sk->sk_callback_lock);
 760         dprintk("RPC:      xs_tcp_data_ready...\n");
 761         if (!(xprt = xprt_from_sock(sk)))
 762                 goto out;
 763         if (xprt->shutdown)
 764                 goto out;
 765
 766         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
 767         rd_desc.arg.data = xprt;
 768         rd_desc.count = 65536;
 769         tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
 770 out:
 771         read_unlock(&sk->sk_callback_lock);
 772 }
 773
 774 /**
 775  * xs_tcp_state_change - callback to handle TCP socket state changes
 776  * @sk: socket whose state has changed
 777  *
 778  */
 779 static void xs_tcp_state_change(struct sock *sk)
 780 {
 781         struct rpc_xprt *xprt;
 782
 783         read_lock(&sk->sk_callback_lock);
 784         if (!(xprt = xprt_from_sock(sk)))
 785                 goto out;
 786         dprintk("RPC:      xs_tcp_state_change client %p...\n", xprt);
 787         dprintk("RPC:      state %x conn %d dead %d zapped %d\n",
 788                                 sk->sk_state, xprt_connected(xprt),
 789                                 sock_flag(sk, SOCK_DEAD),
 790                                 sock_flag(sk, SOCK_ZAPPED));
 791
 792         switch (sk->sk_state) {
 793         case TCP_ESTABLISHED:
 794                 spin_lock_bh(&xprt->transport_lock);
 795                 if (!xprt_test_and_set_connected(xprt)) {
 796                         /* Reset TCP record info */
 797                         xprt->tcp_offset = 0;
 798                         xprt->tcp_reclen = 0;
 799                         xprt->tcp_copied = 0;
 800                         xprt->tcp_flags = XPRT_COPY_RECM | XPRT_COPY_XID;
 801                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
 802                         xprt_wake_pending_tasks(xprt, 0);
 803                 }
 804                 spin_unlock_bh(&xprt->transport_lock);
 805                 break;
 806         case TCP_SYN_SENT:
 807         case TCP_SYN_RECV:
 808                 break;
 809         case TCP_CLOSE_WAIT:
 810                 /* Try to schedule an autoclose RPC calls */
 811                 set_bit(XPRT_CLOSE_WAIT, &xprt->state);
 812                 if (test_and_set_bit(XPRT_LOCKED, &xprt->state) == 0)
 813                         schedule_work(&xprt->task_cleanup);
 814         default:
 815                 xprt_disconnect(xprt);
 816         }
 817  out:
 818         read_unlock(&sk->sk_callback_lock);
 819 }
 820
 821 /**
 822  * xs_udp_write_space - callback invoked when socket buffer space
 823  *                             becomes available
 824  * @sk: socket whose state has changed
 825  *
 826  * Called when more output buffer space is available for this socket.
 827  * We try not to wake our writers until they can make "significant"
 828  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
 829  * with a bunch of small requests.
 830  */
 831 static void xs_udp_write_space(struct sock *sk)
 832 {
 833         read_lock(&sk->sk_callback_lock);
 834
 835         /* from net/core/sock.c:sock_def_write_space */
 836         if (sock_writeable(sk)) {
 837                 struct socket *sock;
 838                 struct rpc_xprt *xprt;
 839
 840                 if (unlikely(!(sock = sk->sk_socket)))
 841                         goto out;
 842                 if (unlikely(!(xprt = xprt_from_sock(sk))))
 843                         goto out;
 844                 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
 845                         goto out;
 846
 847                 xprt_write_space(xprt);
 848         }
 849
 850  out:
 851         read_unlock(&sk->sk_callback_lock);
 852 }
 853
 854 /**
 855  * xs_tcp_write_space - callback invoked when socket buffer space
 856  *                             becomes available
 857  * @sk: socket whose state has changed
 858  *
 859  * Called when more output buffer space is available for this socket.
 860  * We try not to wake our writers until they can make "significant"
 861  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
 862  * with a bunch of small requests.
 863  */
 864 static void xs_tcp_write_space(struct sock *sk)
 865 {
 866         read_lock(&sk->sk_callback_lock);
 867
 868         /* from net/core/stream.c:sk_stream_write_space */
 869         if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk)) {
 870                 struct socket *sock;
 871                 struct rpc_xprt *xprt;
 872
 873                 if (unlikely(!(sock = sk->sk_socket)))
 874                         goto out;
 875                 if (unlikely(!(xprt = xprt_from_sock(sk))))
 876                         goto out;
 877                 if (unlikely(!test_and_clear_bit(SOCK_NOSPACE, &sock->flags)))
 878                         goto out;
 879
 880                 xprt_write_space(xprt);
 881         }
 882
 883  out:
 884         read_unlock(&sk->sk_callback_lock);
 885 }
 886
 887 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
 888 {
 889         struct sock *sk = xprt->inet;
 890
 891         if (xprt->rcvsize) {
 892                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
 893                 sk->sk_rcvbuf = xprt->rcvsize * xprt->max_reqs *  2;
 894         }
 895         if (xprt->sndsize) {
 896                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
 897                 sk->sk_sndbuf = xprt->sndsize * xprt->max_reqs * 2;
 898                 sk->sk_write_space(sk);
 899         }
 900 }
 901
 902 /**
 903  * xs_udp_set_buffer_size - set send and receive limits
 904  * @xprt: generic transport
 905  * @sndsize: requested size of send buffer, in bytes
 906  * @rcvsize: requested size of receive buffer, in bytes
 907  *
 908  * Set socket send and receive buffer size limits.
 909  */
 910 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
 911 {
 912         xprt->sndsize = 0;
 913         if (sndsize)
 914                 xprt->sndsize = sndsize + 1024;
 915         xprt->rcvsize = 0;
 916         if (rcvsize)
 917                 xprt->rcvsize = rcvsize + 1024;
 918
 919         xs_udp_do_set_buffer_size(xprt);
 920 }
 921
 922 /**
 923  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
 924  * @task: task that timed out
 925  *
 926  * Adjust the congestion window after a retransmit timeout has occurred.
 927  */
 928 static void xs_udp_timer(struct rpc_task *task)
 929 {
 930         xprt_adjust_cwnd(task, -ETIMEDOUT);
 931 }
 932
 933 static unsigned short xs_get_random_port(void)
 934 {
 935         unsigned short range = xprt_max_resvport - xprt_min_resvport;
 936         unsigned short rand = (unsigned short) net_random() % range;
 937         return rand + xprt_min_resvport;
 938 }
 939
 940 /**
 941  * xs_set_port - reset the port number in the remote endpoint address
 942  * @xprt: generic transport
 943  * @port: new port number
 944  *
 945  */
 946 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
 947 {
 948         dprintk("RPC:      setting port for xprt %p to %u\n", xprt, port);
 949         xprt->addr.sin_port = htons(port);
 950 }
 951
 952 static int xs_bindresvport(struct rpc_xprt *xprt, struct socket *sock)
 953 {
 954         struct sockaddr_in myaddr = {
 955                 .sin_family = AF_INET,
 956         };
 957         int err;
 958         unsigned short port = xprt->port;
 959
 960         do {
 961                 myaddr.sin_port = htons(port);
 962                 err = sock->ops->bind(sock, (struct sockaddr *) &myaddr,
 963                                                 sizeof(myaddr));
 964                 if (err == 0) {
 965                         xprt->port = port;
 966                         dprintk("RPC:      xs_bindresvport bound to port %u\n",
 967                                         port);
 968                         return 0;
 969                 }
 970                 if (port <= xprt_min_resvport)
 971                         port = xprt_max_resvport;
 972                 else
 973                         port--;
 974         } while (err == -EADDRINUSE && port != xprt->port);
 975
 976         dprintk("RPC:      can't bind to reserved port (%d).\n", -err);
 977         return err;
 978 }
 979
 980 /**
 981  * xs_udp_connect_worker - set up a UDP socket
 982  * @args: RPC transport to connect
 983  *
 984  * Invoked by a work queue tasklet.
 985  */
 986 static void xs_udp_connect_worker(void *args)
 987 {
 988         struct rpc_xprt *xprt = (struct rpc_xprt *) args;
 989         struct socket *sock = xprt->sock;
 990         int err, status = -EIO;
 991
 992         if (xprt->shutdown || xprt->addr.sin_port == 0)
 993                 goto out;
 994
 995         dprintk("RPC:      xs_udp_connect_worker for xprt %p\n", xprt);
 996
 997         /* Start by resetting any existing state */
 998         xs_close(xprt);
 999
1000         if ((err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock)) < 0) {
1001                 dprintk("RPC:      can't create UDP transport socket (%d).\n", -err);
1002                 goto out;
1003         }
1004
1005         if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
1006                 sock_release(sock);
1007                 goto out;
1008         }
1009
1010         if (!xprt->inet) {
1011                 struct sock *sk = sock->sk;
1012
1013                 write_lock_bh(&sk->sk_callback_lock);
1014
1015                 sk->sk_user_data = xprt;
1016                 xprt->old_data_ready = sk->sk_data_ready;
1017                 xprt->old_state_change = sk->sk_state_change;
1018                 xprt->old_write_space = sk->sk_write_space;
1019                 sk->sk_data_ready = xs_udp_data_ready;
1020                 sk->sk_write_space = xs_udp_write_space;
1021                 sk->sk_no_check = UDP_CSUM_NORCV;
1022                 sk->sk_allocation = GFP_ATOMIC;
1023
1024                 xprt_set_connected(xprt);
1025
1026                 /* Reset to new socket */
1027                 xprt->sock = sock;
1028                 xprt->inet = sk;
1029
1030                 write_unlock_bh(&sk->sk_callback_lock);
1031         }
1032         xs_udp_do_set_buffer_size(xprt);
1033         status = 0;
1034 out:
1035         xprt_wake_pending_tasks(xprt, status);
1036         xprt_clear_connecting(xprt);
1037 }
1038
1039 /*
1040  * We need to preserve the port number so the reply cache on the server can
1041  * find our cached RPC replies when we get around to reconnecting.
1042  */
1043 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt)
1044 {
1045         int result;
1046         struct socket *sock = xprt->sock;
1047         struct sockaddr any;
1048
1049         dprintk("RPC:      disconnecting xprt %p to reuse port\n", xprt);
1050
1051         /*
1052          * Disconnect the transport socket by doing a connect operation
1053          * with AF_UNSPEC.  This should return immediately...
1054          */
1055         memset(&any, 0, sizeof(any));
1056         any.sa_family = AF_UNSPEC;
1057         result = sock->ops->connect(sock, &any, sizeof(any), 0);
1058         if (result)
1059                 dprintk("RPC:      AF_UNSPEC connect return code %d\n",
1060                                 result);
1061 }
1062
1063 /**
1064  * xs_tcp_connect_worker - connect a TCP socket to a remote endpoint
1065  * @args: RPC transport to connect
1066  *
1067  * Invoked by a work queue tasklet.
1068  */
1069 static void xs_tcp_connect_worker(void *args)
1070 {
1071         struct rpc_xprt *xprt = (struct rpc_xprt *)args;
1072         struct socket *sock = xprt->sock;
1073         int err, status = -EIO;
1074
1075         if (xprt->shutdown || xprt->addr.sin_port == 0)
1076                 goto out;
1077
1078         dprintk("RPC:      xs_tcp_connect_worker for xprt %p\n", xprt);
1079
1080         if (!xprt->sock) {
1081                 /* start from scratch */
1082                 if ((err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock)) < 0) {
1083                         dprintk("RPC:      can't create TCP transport socket (%d).\n", -err);
1084                         goto out;
1085                 }
1086
1087                 if (xprt->resvport && xs_bindresvport(xprt, sock) < 0) {
1088                         sock_release(sock);
1089                         goto out;
1090                 }
1091         } else
1092                 /* "close" the socket, preserving the local port */
1093                 xs_tcp_reuse_connection(xprt);
1094
1095         if (!xprt->inet) {
1096                 struct sock *sk = sock->sk;
1097
1098                 write_lock_bh(&sk->sk_callback_lock);
1099
1100                 sk->sk_user_data = xprt;
1101                 xprt->old_data_ready = sk->sk_data_ready;
1102                 xprt->old_state_change = sk->sk_state_change;
1103                 xprt->old_write_space = sk->sk_write_space;
1104                 sk->sk_data_ready = xs_tcp_data_ready;
1105                 sk->sk_state_change = xs_tcp_state_change;
1106                 sk->sk_write_space = xs_tcp_write_space;
1107                 sk->sk_allocation = GFP_ATOMIC;
1108
1109                 /* socket options */
1110                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1111                 sock_reset_flag(sk, SOCK_LINGER);
1112                 tcp_sk(sk)->linger2 = 0;
1113                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1114
1115                 xprt_clear_connected(xprt);
1116
1117                 /* Reset to new socket */
1118                 xprt->sock = sock;
1119                 xprt->inet = sk;
1120
1121                 write_unlock_bh(&sk->sk_callback_lock);
1122         }
1123
1124         /* Tell the socket layer to start connecting... */
1125         xprt->stat.connect_count++;
1126         xprt->stat.connect_start = jiffies;
1127         status = sock->ops->connect(sock, (struct sockaddr *) &xprt->addr,
1128                         sizeof(xprt->addr), O_NONBLOCK);
1129         dprintk("RPC: %p  connect status %d connected %d sock state %d\n",
1130                         xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
1131         if (status < 0) {
1132                 switch (status) {
1133                         case -EINPROGRESS:
1134                         case -EALREADY:
1135                                 goto out_clear;
1136                         case -ECONNREFUSED:
1137                         case -ECONNRESET:
1138                                 /* retry with existing socket, after a delay */
1139                                 break;
1140                         default:
1141                                 /* get rid of existing socket, and retry */
1142                                 xs_close(xprt);
1143                                 break;
1144                 }
1145         }
1146 out:
1147         xprt_wake_pending_tasks(xprt, status);
1148 out_clear:
1149         xprt_clear_connecting(xprt);
1150 }
1151
1152 /**
1153  * xs_connect - connect a socket to a remote endpoint
1154  * @task: address of RPC task that manages state of connect request
1155  *
1156  * TCP: If the remote end dropped the connection, delay reconnecting.
1157  *
1158  * UDP socket connects are synchronous, but we use a work queue anyway
1159  * to guarantee that even unprivileged user processes can set up a
1160  * socket on a privileged port.
1161  *
1162  * If a UDP socket connect fails, the delay behavior here prevents
1163  * retry floods (hard mounts).
1164  */
1165 static void xs_connect(struct rpc_task *task)
1166 {
1167         struct rpc_xprt *xprt = task->tk_xprt;
1168
1169         if (xprt_test_and_set_connecting(xprt))
1170                 return;
1171
1172         if (xprt->sock != NULL) {
1173                 dprintk("RPC:      xs_connect delayed xprt %p for %lu seconds\n",
1174                                 xprt, xprt->reestablish_timeout / HZ);
1175                 schedule_delayed_work(&xprt->connect_worker,
1176                                         xprt->reestablish_timeout);
1177                 xprt->reestablish_timeout <<= 1;
1178                 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
1179                         xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
1180         } else {
1181                 dprintk("RPC:      xs_connect scheduled xprt %p\n", xprt);
1182                 schedule_work(&xprt->connect_worker);
1183
1184                 /* flush_scheduled_work can sleep... */
1185                 if (!RPC_IS_ASYNC(task))
1186                         flush_scheduled_work();
1187         }
1188 }
1189
1190 /**
1191  * xs_udp_print_stats - display UDP socket-specifc stats
1192  * @xprt: rpc_xprt struct containing statistics
1193  * @seq: output file
1194  *
1195  */
1196 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1197 {
1198         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
1199                         xprt->port,
1200                         xprt->stat.bind_count,
1201                         xprt->stat.sends,
1202                         xprt->stat.recvs,
1203                         xprt->stat.bad_xids,
1204                         xprt->stat.req_u,
1205                         xprt->stat.bklog_u);
1206 }
1207
1208 /**
1209  * xs_tcp_print_stats - display TCP socket-specifc stats
1210  * @xprt: rpc_xprt struct containing statistics
1211  * @seq: output file
1212  *
1213  */
1214 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
1215 {
1216         long idle_time = 0;
1217
1218         if (xprt_connected(xprt))
1219                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
1220
1221         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
1222                         xprt->port,
1223                         xprt->stat.bind_count,
1224                         xprt->stat.connect_count,
1225                         xprt->stat.connect_time,
1226                         idle_time,
1227                         xprt->stat.sends,
1228                         xprt->stat.recvs,
1229                         xprt->stat.bad_xids,
1230                         xprt->stat.req_u,
1231                         xprt->stat.bklog_u);
1232 }
1233
1234 static struct rpc_xprt_ops xs_udp_ops = {
1235         .set_buffer_size        = xs_udp_set_buffer_size,
1236         .reserve_xprt           = xprt_reserve_xprt_cong,
1237         .release_xprt           = xprt_release_xprt_cong,
1238         .set_port               = xs_set_port,
1239         .connect                = xs_connect,
1240         .buf_alloc              = rpc_malloc,
1241         .buf_free               = rpc_free,
1242         .send_request           = xs_udp_send_request,
1243         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
1244         .timer                  = xs_udp_timer,
1245         .release_request        = xprt_release_rqst_cong,
1246         .close                  = xs_close,
1247         .destroy                = xs_destroy,
1248         .print_stats            = xs_udp_print_stats,
1249 };
1250
1251 static struct rpc_xprt_ops xs_tcp_ops = {
1252         .reserve_xprt           = xprt_reserve_xprt,
1253         .release_xprt           = xprt_release_xprt,
1254         .set_port               = xs_set_port,
1255         .connect                = xs_connect,
1256         .buf_alloc              = rpc_malloc,
1257         .buf_free               = rpc_free,
1258         .send_request           = xs_tcp_send_request,
1259         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
1260         .close                  = xs_close,
1261         .destroy                = xs_destroy,
1262         .print_stats            = xs_tcp_print_stats,
1263 };
1264
1265 /**
1266  * xs_setup_udp - Set up transport to use a UDP socket
1267  * @xprt: transport to set up
1268  * @to:   timeout parameters
1269  *
1270  */
1271 int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to)
1272 {
1273         size_t slot_table_size;
1274
1275         dprintk("RPC:      setting up udp-ipv4 transport...\n");
1276
1277         xprt->max_reqs = xprt_udp_slot_table_entries;
1278         slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
1279         xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
1280         if (xprt->slot == NULL)
1281                 return -ENOMEM;
1282         memset(xprt->slot, 0, slot_table_size);
1283
1284         xprt->prot = IPPROTO_UDP;
1285         xprt->port = xs_get_random_port();
1286         xprt->tsh_size = 0;
1287         xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
1288         /* XXX: header size can vary due to auth type, IPv6, etc. */
1289         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
1290
1291         INIT_WORK(&xprt->connect_worker, xs_udp_connect_worker, xprt);
1292         xprt->bind_timeout = XS_BIND_TO;
1293         xprt->connect_timeout = XS_UDP_CONN_TO;
1294         xprt->reestablish_timeout = XS_UDP_REEST_TO;
1295         xprt->idle_timeout = XS_IDLE_DISC_TO;
1296
1297         xprt->ops = &xs_udp_ops;
1298
1299         if (to)
1300                 xprt->timeout = *to;
1301         else
1302                 xprt_set_timeout(&xprt->timeout, 5, 5 * HZ);
1303
1304         return 0;
1305 }
1306
1307 /**
1308  * xs_setup_tcp - Set up transport to use a TCP socket
1309  * @xprt: transport to set up
1310  * @to: timeout parameters
1311  *
1312  */
1313 int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to)
1314 {
1315         size_t slot_table_size;
1316
1317         dprintk("RPC:      setting up tcp-ipv4 transport...\n");
1318
1319         xprt->max_reqs = xprt_tcp_slot_table_entries;
1320         slot_table_size = xprt->max_reqs * sizeof(xprt->slot[0]);
1321         xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
1322         if (xprt->slot == NULL)
1323                 return -ENOMEM;
1324         memset(xprt->slot, 0, slot_table_size);
1325
1326         xprt->prot = IPPROTO_TCP;
1327         xprt->port = xs_get_random_port();
1328         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
1329         xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
1330         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
1331
1332         INIT_WORK(&xprt->connect_worker, xs_tcp_connect_worker, xprt);
1333         xprt->bind_timeout = XS_BIND_TO;
1334         xprt->connect_timeout = XS_TCP_CONN_TO;
1335         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1336         xprt->idle_timeout = XS_IDLE_DISC_TO;
1337
1338         xprt->ops = &xs_tcp_ops;
1339
1340         if (to)
1341                 xprt->timeout = *to;
1342         else
1343                 xprt_set_timeout(&xprt->timeout, 2, 60 * HZ);
1344
1345         return 0;
1346 }