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
   7  * TCP send fixes (C) 1998 Red Hat
   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  * IPv6 support contributed by Gilles Quillard, Bull Open Source, 2005.
  18  *   <gilles.quillard@bull.net>
  19  */
  20
  21 #include <linux/types.h>
  22 #include <linux/slab.h>
  23 #include <linux/module.h>
  24 #include <linux/capability.h>
  25 #include <linux/pagemap.h>
  26 #include <linux/errno.h>
  27 #include <linux/socket.h>
  28 #include <linux/in.h>
  29 #include <linux/net.h>
  30 #include <linux/mm.h>
  31 #include <linux/udp.h>
  32 #include <linux/tcp.h>
  33 #include <linux/sunrpc/clnt.h>
  34 #include <linux/sunrpc/sched.h>
  35 #include <linux/sunrpc/svcsock.h>
  36 #include <linux/sunrpc/xprtsock.h>
  37 #include <linux/file.h>
  38 #ifdef CONFIG_NFS_V4_1
  39 #include <linux/sunrpc/bc_xprt.h>
  40 #endif
  41
  42 #include <net/sock.h>
  43 #include <net/checksum.h>
  44 #include <net/udp.h>
  45 #include <net/tcp.h>
  46
  47 #include "sunrpc.h"
  48 /*
  49  * xprtsock tunables
  50  */
  51 unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  52 unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  53
  54 unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
  55 unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
  56
  57 #define XS_TCP_LINGER_TO        (15U * HZ)
  58 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
  59
  60 /*
  61  * We can register our own files under /proc/sys/sunrpc by
  62  * calling register_sysctl_table() again.  The files in that
  63  * directory become the union of all files registered there.
  64  *
  65  * We simply need to make sure that we don't collide with
  66  * someone else's file names!
  67  */
  68
  69 #ifdef RPC_DEBUG
  70
  71 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
  72 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
  73 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
  74 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
  75
  76 static struct ctl_table_header *sunrpc_table_header;
  77
  78 /*
  79  * FIXME: changing the UDP slot table size should also resize the UDP
  80  *        socket buffers for existing UDP transports
  81  */
  82 static ctl_table xs_tunables_table[] = {
  83         {
  84                 .procname       = "udp_slot_table_entries",
  85                 .data           = &xprt_udp_slot_table_entries,
  86                 .maxlen         = sizeof(unsigned int),
  87                 .mode           = 0644,
  88                 .proc_handler   = proc_dointvec_minmax,
  89                 .extra1         = &min_slot_table_size,
  90                 .extra2         = &max_slot_table_size
  91         },
  92         {
  93                 .procname       = "tcp_slot_table_entries",
  94                 .data           = &xprt_tcp_slot_table_entries,
  95                 .maxlen         = sizeof(unsigned int),
  96                 .mode           = 0644,
  97                 .proc_handler   = proc_dointvec_minmax,
  98                 .extra1         = &min_slot_table_size,
  99                 .extra2         = &max_slot_table_size
 100         },
 101         {
 102                 .procname       = "min_resvport",
 103                 .data           = &xprt_min_resvport,
 104                 .maxlen         = sizeof(unsigned int),
 105                 .mode           = 0644,
 106                 .proc_handler   = proc_dointvec_minmax,
 107                 .extra1         = &xprt_min_resvport_limit,
 108                 .extra2         = &xprt_max_resvport_limit
 109         },
 110         {
 111                 .procname       = "max_resvport",
 112                 .data           = &xprt_max_resvport,
 113                 .maxlen         = sizeof(unsigned int),
 114                 .mode           = 0644,
 115                 .proc_handler   = proc_dointvec_minmax,
 116                 .extra1         = &xprt_min_resvport_limit,
 117                 .extra2         = &xprt_max_resvport_limit
 118         },
 119         {
 120                 .procname       = "tcp_fin_timeout",
 121                 .data           = &xs_tcp_fin_timeout,
 122                 .maxlen         = sizeof(xs_tcp_fin_timeout),
 123                 .mode           = 0644,
 124                 .proc_handler   = proc_dointvec_jiffies,
 125         },
 126         { },
 127 };
 128
 129 static ctl_table sunrpc_table[] = {
 130         {
 131                 .procname       = "sunrpc",
 132                 .mode           = 0555,
 133                 .child          = xs_tunables_table
 134         },
 135         { },
 136 };
 137
 138 #endif
 139
 140 /*
 141  * Wait duration for a reply from the RPC portmapper.
 142  */
 143 #define XS_BIND_TO              (60U * HZ)
 144
 145 /*
 146  * Delay if a UDP socket connect error occurs.  This is most likely some
 147  * kind of resource problem on the local host.
 148  */
 149 #define XS_UDP_REEST_TO         (2U * HZ)
 150
 151 /*
 152  * The reestablish timeout allows clients to delay for a bit before attempting
 153  * to reconnect to a server that just dropped our connection.
 154  *
 155  * We implement an exponential backoff when trying to reestablish a TCP
 156  * transport connection with the server.  Some servers like to drop a TCP
 157  * connection when they are overworked, so we start with a short timeout and
 158  * increase over time if the server is down or not responding.
 159  */
 160 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
 161 #define XS_TCP_MAX_REEST_TO     (5U * 60 * HZ)
 162
 163 /*
 164  * TCP idle timeout; client drops the transport socket if it is idle
 165  * for this long.  Note that we also timeout UDP sockets to prevent
 166  * holding port numbers when there is no RPC traffic.
 167  */
 168 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
 169
 170 #ifdef RPC_DEBUG
 171 # undef  RPC_DEBUG_DATA
 172 # define RPCDBG_FACILITY        RPCDBG_TRANS
 173 #endif
 174
 175 #ifdef RPC_DEBUG_DATA
 176 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 177 {
 178         u8 *buf = (u8 *) packet;
 179         int j;
 180
 181         dprintk("RPC:       %s\n", msg);
 182         for (j = 0; j < count && j < 128; j += 4) {
 183                 if (!(j & 31)) {
 184                         if (j)
 185                                 dprintk("\n");
 186                         dprintk("0x%04x ", j);
 187                 }
 188                 dprintk("%02x%02x%02x%02x ",
 189                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
 190         }
 191         dprintk("\n");
 192 }
 193 #else
 194 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 195 {
 196         /* NOP */
 197 }
 198 #endif
 199
 200 struct sock_xprt {
 201         struct rpc_xprt         xprt;
 202
 203         /*
 204          * Network layer
 205          */
 206         struct socket *         sock;
 207         struct sock *           inet;
 208
 209         /*
 210          * State of TCP reply receive
 211          */
 212         __be32                  tcp_fraghdr,
 213                                 tcp_xid,
 214                                 tcp_calldir;
 215
 216         u32                     tcp_offset,
 217                                 tcp_reclen;
 218
 219         unsigned long           tcp_copied,
 220                                 tcp_flags;
 221
 222         /*
 223          * Connection of transports
 224          */
 225         struct delayed_work     connect_worker;
 226         struct sockaddr_storage srcaddr;
 227         unsigned short          srcport;
 228
 229         /*
 230          * UDP socket buffer size parameters
 231          */
 232         size_t                  rcvsize,
 233                                 sndsize;
 234
 235         /*
 236          * Saved socket callback addresses
 237          */
 238         void                    (*old_data_ready)(struct sock *, int);
 239         void                    (*old_state_change)(struct sock *);
 240         void                    (*old_write_space)(struct sock *);
 241         void                    (*old_error_report)(struct sock *);
 242 };
 243
 244 /*
 245  * TCP receive state flags
 246  */
 247 #define TCP_RCV_LAST_FRAG       (1UL << 0)
 248 #define TCP_RCV_COPY_FRAGHDR    (1UL << 1)
 249 #define TCP_RCV_COPY_XID        (1UL << 2)
 250 #define TCP_RCV_COPY_DATA       (1UL << 3)
 251 #define TCP_RCV_READ_CALLDIR    (1UL << 4)
 252 #define TCP_RCV_COPY_CALLDIR    (1UL << 5)
 253
 254 /*
 255  * TCP RPC flags
 256  */
 257 #define TCP_RPC_REPLY           (1UL << 6)
 258
 259 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
 260 {
 261         return (struct sockaddr *) &xprt->addr;
 262 }
 263
 264 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
 265 {
 266         return (struct sockaddr_in *) &xprt->addr;
 267 }
 268
 269 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
 270 {
 271         return (struct sockaddr_in6 *) &xprt->addr;
 272 }
 273
 274 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
 275 {
 276         struct sockaddr *sap = xs_addr(xprt);
 277         struct sockaddr_in6 *sin6;
 278         struct sockaddr_in *sin;
 279         char buf[128];
 280
 281         (void)rpc_ntop(sap, buf, sizeof(buf));
 282         xprt->address_strings[RPC_DISPLAY_ADDR] = kstrdup(buf, GFP_KERNEL);
 283
 284         switch (sap->sa_family) {
 285         case AF_INET:
 286                 sin = xs_addr_in(xprt);
 287                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 288                 break;
 289         case AF_INET6:
 290                 sin6 = xs_addr_in6(xprt);
 291                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 292                 break;
 293         default:
 294                 BUG();
 295         }
 296         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 297 }
 298
 299 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
 300 {
 301         struct sockaddr *sap = xs_addr(xprt);
 302         char buf[128];
 303
 304         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 305         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 306
 307         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 308         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 309 }
 310
 311 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
 312                                      const char *protocol,
 313                                      const char *netid)
 314 {
 315         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
 316         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
 317         xs_format_common_peer_addresses(xprt);
 318         xs_format_common_peer_ports(xprt);
 319 }
 320
 321 static void xs_update_peer_port(struct rpc_xprt *xprt)
 322 {
 323         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 324         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 325
 326         xs_format_common_peer_ports(xprt);
 327 }
 328
 329 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
 330 {
 331         unsigned int i;
 332
 333         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 334                 switch (i) {
 335                 case RPC_DISPLAY_PROTO:
 336                 case RPC_DISPLAY_NETID:
 337                         continue;
 338                 default:
 339                         kfree(xprt->address_strings[i]);
 340                 }
 341 }
 342
 343 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
 344
 345 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
 346 {
 347         struct msghdr msg = {
 348                 .msg_name       = addr,
 349                 .msg_namelen    = addrlen,
 350                 .msg_flags      = XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
 351         };
 352         struct kvec iov = {
 353                 .iov_base       = vec->iov_base + base,
 354                 .iov_len        = vec->iov_len - base,
 355         };
 356
 357         if (iov.iov_len != 0)
 358                 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
 359         return kernel_sendmsg(sock, &msg, NULL, 0, 0);
 360 }
 361
 362 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more)
 363 {
 364         struct page **ppage;
 365         unsigned int remainder;
 366         int err, sent = 0;
 367
 368         remainder = xdr->page_len - base;
 369         base += xdr->page_base;
 370         ppage = xdr->pages + (base >> PAGE_SHIFT);
 371         base &= ~PAGE_MASK;
 372         for(;;) {
 373                 unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
 374                 int flags = XS_SENDMSG_FLAGS;
 375
 376                 remainder -= len;
 377                 if (remainder != 0 || more)
 378                         flags |= MSG_MORE;
 379                 err = sock->ops->sendpage(sock, *ppage, base, len, flags);
 380                 if (remainder == 0 || err != len)
 381                         break;
 382                 sent += err;
 383                 ppage++;
 384                 base = 0;
 385         }
 386         if (sent == 0)
 387                 return err;
 388         if (err > 0)
 389                 sent += err;
 390         return sent;
 391 }
 392
 393 /**
 394  * xs_sendpages - write pages directly to a socket
 395  * @sock: socket to send on
 396  * @addr: UDP only -- address of destination
 397  * @addrlen: UDP only -- length of destination address
 398  * @xdr: buffer containing this request
 399  * @base: starting position in the buffer
 400  *
 401  */
 402 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
 403 {
 404         unsigned int remainder = xdr->len - base;
 405         int err, sent = 0;
 406
 407         if (unlikely(!sock))
 408                 return -ENOTSOCK;
 409
 410         clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
 411         if (base != 0) {
 412                 addr = NULL;
 413                 addrlen = 0;
 414         }
 415
 416         if (base < xdr->head[0].iov_len || addr != NULL) {
 417                 unsigned int len = xdr->head[0].iov_len - base;
 418                 remainder -= len;
 419                 err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
 420                 if (remainder == 0 || err != len)
 421                         goto out;
 422                 sent += err;
 423                 base = 0;
 424         } else
 425                 base -= xdr->head[0].iov_len;
 426
 427         if (base < xdr->page_len) {
 428                 unsigned int len = xdr->page_len - base;
 429                 remainder -= len;
 430                 err = xs_send_pagedata(sock, xdr, base, remainder != 0);
 431                 if (remainder == 0 || err != len)
 432                         goto out;
 433                 sent += err;
 434                 base = 0;
 435         } else
 436                 base -= xdr->page_len;
 437
 438         if (base >= xdr->tail[0].iov_len)
 439                 return sent;
 440         err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
 441 out:
 442         if (sent == 0)
 443                 return err;
 444         if (err > 0)
 445                 sent += err;
 446         return sent;
 447 }
 448
 449 static void xs_nospace_callback(struct rpc_task *task)
 450 {
 451         struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
 452
 453         transport->inet->sk_write_pending--;
 454         clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 455 }
 456
 457 /**
 458  * xs_nospace - place task on wait queue if transmit was incomplete
 459  * @task: task to put to sleep
 460  *
 461  */
 462 static int xs_nospace(struct rpc_task *task)
 463 {
 464         struct rpc_rqst *req = task->tk_rqstp;
 465         struct rpc_xprt *xprt = req->rq_xprt;
 466         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 467         int ret = 0;
 468
 469         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
 470                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
 471                         req->rq_slen);
 472
 473         /* Protect against races with write_space */
 474         spin_lock_bh(&xprt->transport_lock);
 475
 476         /* Don't race with disconnect */
 477         if (xprt_connected(xprt)) {
 478                 if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
 479                         ret = -EAGAIN;
 480                         /*
 481                          * Notify TCP that we're limited by the application
 482                          * window size
 483                          */
 484                         set_bit(SOCK_NOSPACE, &transport->sock->flags);
 485                         transport->inet->sk_write_pending++;
 486                         /* ...and wait for more buffer space */
 487                         xprt_wait_for_buffer_space(task, xs_nospace_callback);
 488                 }
 489         } else {
 490                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 491                 ret = -ENOTCONN;
 492         }
 493
 494         spin_unlock_bh(&xprt->transport_lock);
 495         return ret;
 496 }
 497
 498 /**
 499  * xs_udp_send_request - write an RPC request to a UDP socket
 500  * @task: address of RPC task that manages the state of an RPC request
 501  *
 502  * Return values:
 503  *        0:    The request has been sent
 504  *   EAGAIN:    The socket was blocked, please call again later to
 505  *              complete the request
 506  * ENOTCONN:    Caller needs to invoke connect logic then call again
 507  *    other:    Some other error occured, the request was not sent
 508  */
 509 static int xs_udp_send_request(struct rpc_task *task)
 510 {
 511         struct rpc_rqst *req = task->tk_rqstp;
 512         struct rpc_xprt *xprt = req->rq_xprt;
 513         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 514         struct xdr_buf *xdr = &req->rq_snd_buf;
 515         int status;
 516
 517         xs_pktdump("packet data:",
 518                                 req->rq_svec->iov_base,
 519                                 req->rq_svec->iov_len);
 520
 521         if (!xprt_bound(xprt))
 522                 return -ENOTCONN;
 523         status = xs_sendpages(transport->sock,
 524                               xs_addr(xprt),
 525                               xprt->addrlen, xdr,
 526                               req->rq_bytes_sent);
 527
 528         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
 529                         xdr->len - req->rq_bytes_sent, status);
 530
 531         if (status >= 0) {
 532                 req->rq_xmit_bytes_sent += status;
 533                 if (status >= req->rq_slen)
 534                         return 0;
 535                 /* Still some bytes left; set up for a retry later. */
 536                 status = -EAGAIN;
 537         }
 538
 539         switch (status) {
 540         case -ENOTSOCK:
 541                 status = -ENOTCONN;
 542                 /* Should we call xs_close() here? */
 543                 break;
 544         case -EAGAIN:
 545                 status = xs_nospace(task);
 546                 break;
 547         default:
 548                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 549                         -status);
 550         case -ENETUNREACH:
 551         case -EPIPE:
 552         case -ECONNREFUSED:
 553                 /* When the server has died, an ICMP port unreachable message
 554                  * prompts ECONNREFUSED. */
 555                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 556         }
 557
 558         return status;
 559 }
 560
 561 /**
 562  * xs_tcp_shutdown - gracefully shut down a TCP socket
 563  * @xprt: transport
 564  *
 565  * Initiates a graceful shutdown of the TCP socket by calling the
 566  * equivalent of shutdown(SHUT_WR);
 567  */
 568 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
 569 {
 570         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 571         struct socket *sock = transport->sock;
 572
 573         if (sock != NULL)
 574                 kernel_sock_shutdown(sock, SHUT_WR);
 575 }
 576
 577 static inline void xs_encode_tcp_record_marker(struct xdr_buf *buf)
 578 {
 579         u32 reclen = buf->len - sizeof(rpc_fraghdr);
 580         rpc_fraghdr *base = buf->head[0].iov_base;
 581         *base = htonl(RPC_LAST_STREAM_FRAGMENT | reclen);
 582 }
 583
 584 /**
 585  * xs_tcp_send_request - write an RPC request to a TCP socket
 586  * @task: address of RPC task that manages the state of an RPC request
 587  *
 588  * Return values:
 589  *        0:    The request has been sent
 590  *   EAGAIN:    The socket was blocked, please call again later to
 591  *              complete the request
 592  * ENOTCONN:    Caller needs to invoke connect logic then call again
 593  *    other:    Some other error occured, the request was not sent
 594  *
 595  * XXX: In the case of soft timeouts, should we eventually give up
 596  *      if sendmsg is not able to make progress?
 597  */
 598 static int xs_tcp_send_request(struct rpc_task *task)
 599 {
 600         struct rpc_rqst *req = task->tk_rqstp;
 601         struct rpc_xprt *xprt = req->rq_xprt;
 602         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 603         struct xdr_buf *xdr = &req->rq_snd_buf;
 604         int status;
 605
 606         xs_encode_tcp_record_marker(&req->rq_snd_buf);
 607
 608         xs_pktdump("packet data:",
 609                                 req->rq_svec->iov_base,
 610                                 req->rq_svec->iov_len);
 611
 612         /* Continue transmitting the packet/record. We must be careful
 613          * to cope with writespace callbacks arriving _after_ we have
 614          * called sendmsg(). */
 615         while (1) {
 616                 status = xs_sendpages(transport->sock,
 617                                         NULL, 0, xdr, req->rq_bytes_sent);
 618
 619                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 620                                 xdr->len - req->rq_bytes_sent, status);
 621
 622                 if (unlikely(status < 0))
 623                         break;
 624
 625                 /* If we've sent the entire packet, immediately
 626                  * reset the count of bytes sent. */
 627                 req->rq_bytes_sent += status;
 628                 req->rq_xmit_bytes_sent += status;
 629                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 630                         req->rq_bytes_sent = 0;
 631                         return 0;
 632                 }
 633
 634                 if (status != 0)
 635                         continue;
 636                 status = -EAGAIN;
 637                 break;
 638         }
 639
 640         switch (status) {
 641         case -ENOTSOCK:
 642                 status = -ENOTCONN;
 643                 /* Should we call xs_close() here? */
 644                 break;
 645         case -EAGAIN:
 646                 status = xs_nospace(task);
 647                 break;
 648         default:
 649                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 650                         -status);
 651         case -ECONNRESET:
 652         case -EPIPE:
 653                 xs_tcp_shutdown(xprt);
 654         case -ECONNREFUSED:
 655         case -ENOTCONN:
 656                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 657         }
 658
 659         return status;
 660 }
 661
 662 /**
 663  * xs_tcp_release_xprt - clean up after a tcp transmission
 664  * @xprt: transport
 665  * @task: rpc task
 666  *
 667  * This cleans up if an error causes us to abort the transmission of a request.
 668  * In this case, the socket may need to be reset in order to avoid confusing
 669  * the server.
 670  */
 671 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 672 {
 673         struct rpc_rqst *req;
 674
 675         if (task != xprt->snd_task)
 676                 return;
 677         if (task == NULL)
 678                 goto out_release;
 679         req = task->tk_rqstp;
 680         if (req->rq_bytes_sent == 0)
 681                 goto out_release;
 682         if (req->rq_bytes_sent == req->rq_snd_buf.len)
 683                 goto out_release;
 684         set_bit(XPRT_CLOSE_WAIT, &task->tk_xprt->state);
 685 out_release:
 686         xprt_release_xprt(xprt, task);
 687 }
 688
 689 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 690 {
 691         transport->old_data_ready = sk->sk_data_ready;
 692         transport->old_state_change = sk->sk_state_change;
 693         transport->old_write_space = sk->sk_write_space;
 694         transport->old_error_report = sk->sk_error_report;
 695 }
 696
 697 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 698 {
 699         sk->sk_data_ready = transport->old_data_ready;
 700         sk->sk_state_change = transport->old_state_change;
 701         sk->sk_write_space = transport->old_write_space;
 702         sk->sk_error_report = transport->old_error_report;
 703 }
 704
 705 static void xs_reset_transport(struct sock_xprt *transport)
 706 {
 707         struct socket *sock = transport->sock;
 708         struct sock *sk = transport->inet;
 709
 710         if (sk == NULL)
 711                 return;
 712
 713         write_lock_bh(&sk->sk_callback_lock);
 714         transport->inet = NULL;
 715         transport->sock = NULL;
 716
 717         sk->sk_user_data = NULL;
 718
 719         xs_restore_old_callbacks(transport, sk);
 720         write_unlock_bh(&sk->sk_callback_lock);
 721
 722         sk->sk_no_check = 0;
 723
 724         sock_release(sock);
 725 }
 726
 727 /**
 728  * xs_close - close a socket
 729  * @xprt: transport
 730  *
 731  * This is used when all requests are complete; ie, no DRC state remains
 732  * on the server we want to save.
 733  *
 734  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
 735  * xs_reset_transport() zeroing the socket from underneath a writer.
 736  */
 737 static void xs_close(struct rpc_xprt *xprt)
 738 {
 739         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 740
 741         dprintk("RPC:       xs_close xprt %p\n", xprt);
 742
 743         xs_reset_transport(transport);
 744         xprt->reestablish_timeout = 0;
 745
 746         smp_mb__before_clear_bit();
 747         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
 748         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
 749         clear_bit(XPRT_CLOSING, &xprt->state);
 750         smp_mb__after_clear_bit();
 751         xprt_disconnect_done(xprt);
 752 }
 753
 754 static void xs_tcp_close(struct rpc_xprt *xprt)
 755 {
 756         if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
 757                 xs_close(xprt);
 758         else
 759                 xs_tcp_shutdown(xprt);
 760 }
 761
 762 /**
 763  * xs_destroy - prepare to shutdown a transport
 764  * @xprt: doomed transport
 765  *
 766  */
 767 static void xs_destroy(struct rpc_xprt *xprt)
 768 {
 769         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 770
 771         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
 772
 773         cancel_rearming_delayed_work(&transport->connect_worker);
 774
 775         xs_close(xprt);
 776         xs_free_peer_addresses(xprt);
 777         kfree(xprt->slot);
 778         kfree(xprt);
 779         module_put(THIS_MODULE);
 780 }
 781
 782 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
 783 {
 784         return (struct rpc_xprt *) sk->sk_user_data;
 785 }
 786
 787 /**
 788  * xs_udp_data_ready - "data ready" callback for UDP sockets
 789  * @sk: socket with data to read
 790  * @len: how much data to read
 791  *
 792  */
 793 static void xs_udp_data_ready(struct sock *sk, int len)
 794 {
 795         struct rpc_task *task;
 796         struct rpc_xprt *xprt;
 797         struct rpc_rqst *rovr;
 798         struct sk_buff *skb;
 799         int err, repsize, copied;
 800         u32 _xid;
 801         __be32 *xp;
 802
 803         read_lock(&sk->sk_callback_lock);
 804         dprintk("RPC:       xs_udp_data_ready...\n");
 805         if (!(xprt = xprt_from_sock(sk)))
 806                 goto out;
 807
 808         if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
 809                 goto out;
 810
 811         if (xprt->shutdown)
 812                 goto dropit;
 813
 814         repsize = skb->len - sizeof(struct udphdr);
 815         if (repsize < 4) {
 816                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
 817                 goto dropit;
 818         }
 819
 820         /* Copy the XID from the skb... */
 821         xp = skb_header_pointer(skb, sizeof(struct udphdr),
 822                                 sizeof(_xid), &_xid);
 823         if (xp == NULL)
 824                 goto dropit;
 825
 826         /* Look up and lock the request corresponding to the given XID */
 827         spin_lock(&xprt->transport_lock);
 828         rovr = xprt_lookup_rqst(xprt, *xp);
 829         if (!rovr)
 830                 goto out_unlock;
 831         task = rovr->rq_task;
 832
 833         if ((copied = rovr->rq_private_buf.buflen) > repsize)
 834                 copied = repsize;
 835
 836         /* Suck it into the iovec, verify checksum if not done by hw. */
 837         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
 838                 UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
 839                 goto out_unlock;
 840         }
 841
 842         UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
 843
 844         /* Something worked... */
 845         dst_confirm(skb_dst(skb));
 846
 847         xprt_adjust_cwnd(task, copied);
 848         xprt_complete_rqst(task, copied);
 849
 850  out_unlock:
 851         spin_unlock(&xprt->transport_lock);
 852  dropit:
 853         skb_free_datagram(sk, skb);
 854  out:
 855         read_unlock(&sk->sk_callback_lock);
 856 }
 857
 858 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
 859 {
 860         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 861         size_t len, used;
 862         char *p;
 863
 864         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
 865         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
 866         used = xdr_skb_read_bits(desc, p, len);
 867         transport->tcp_offset += used;
 868         if (used != len)
 869                 return;
 870
 871         transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
 872         if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
 873                 transport->tcp_flags |= TCP_RCV_LAST_FRAG;
 874         else
 875                 transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
 876         transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
 877
 878         transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
 879         transport->tcp_offset = 0;
 880
 881         /* Sanity check of the record length */
 882         if (unlikely(transport->tcp_reclen < 8)) {
 883                 dprintk("RPC:       invalid TCP record fragment length\n");
 884                 xprt_force_disconnect(xprt);
 885                 return;
 886         }
 887         dprintk("RPC:       reading TCP record fragment of length %d\n",
 888                         transport->tcp_reclen);
 889 }
 890
 891 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
 892 {
 893         if (transport->tcp_offset == transport->tcp_reclen) {
 894                 transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
 895                 transport->tcp_offset = 0;
 896                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
 897                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
 898                         transport->tcp_flags |= TCP_RCV_COPY_XID;
 899                         transport->tcp_copied = 0;
 900                 }
 901         }
 902 }
 903
 904 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
 905 {
 906         size_t len, used;
 907         char *p;
 908
 909         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
 910         dprintk("RPC:       reading XID (%Zu bytes)\n", len);
 911         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
 912         used = xdr_skb_read_bits(desc, p, len);
 913         transport->tcp_offset += used;
 914         if (used != len)
 915                 return;
 916         transport->tcp_flags &= ~TCP_RCV_COPY_XID;
 917         transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
 918         transport->tcp_copied = 4;
 919         dprintk("RPC:       reading %s XID %08x\n",
 920                         (transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
 921                                                               : "request with",
 922                         ntohl(transport->tcp_xid));
 923         xs_tcp_check_fraghdr(transport);
 924 }
 925
 926 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
 927                                        struct xdr_skb_reader *desc)
 928 {
 929         size_t len, used;
 930         u32 offset;
 931         char *p;
 932
 933         /*
 934          * We want transport->tcp_offset to be 8 at the end of this routine
 935          * (4 bytes for the xid and 4 bytes for the call/reply flag).
 936          * When this function is called for the first time,
 937          * transport->tcp_offset is 4 (after having already read the xid).
 938          */
 939         offset = transport->tcp_offset - sizeof(transport->tcp_xid);
 940         len = sizeof(transport->tcp_calldir) - offset;
 941         dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
 942         p = ((char *) &transport->tcp_calldir) + offset;
 943         used = xdr_skb_read_bits(desc, p, len);
 944         transport->tcp_offset += used;
 945         if (used != len)
 946                 return;
 947         transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
 948         /*
 949          * We don't yet have the XDR buffer, so we will write the calldir
 950          * out after we get the buffer from the 'struct rpc_rqst'
 951          */
 952         switch (ntohl(transport->tcp_calldir)) {
 953         case RPC_REPLY:
 954                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
 955                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
 956                 transport->tcp_flags |= TCP_RPC_REPLY;
 957                 break;
 958         case RPC_CALL:
 959                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
 960                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
 961                 transport->tcp_flags &= ~TCP_RPC_REPLY;
 962                 break;
 963         default:
 964                 dprintk("RPC:       invalid request message type\n");
 965                 xprt_force_disconnect(&transport->xprt);
 966         }
 967         xs_tcp_check_fraghdr(transport);
 968 }
 969
 970 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
 971                                      struct xdr_skb_reader *desc,
 972                                      struct rpc_rqst *req)
 973 {
 974         struct sock_xprt *transport =
 975                                 container_of(xprt, struct sock_xprt, xprt);
 976         struct xdr_buf *rcvbuf;
 977         size_t len;
 978         ssize_t r;
 979
 980         rcvbuf = &req->rq_private_buf;
 981
 982         if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
 983                 /*
 984                  * Save the RPC direction in the XDR buffer
 985                  */
 986                 memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
 987                         &transport->tcp_calldir,
 988                         sizeof(transport->tcp_calldir));
 989                 transport->tcp_copied += sizeof(transport->tcp_calldir);
 990                 transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
 991         }
 992
 993         len = desc->count;
 994         if (len > transport->tcp_reclen - transport->tcp_offset) {
 995                 struct xdr_skb_reader my_desc;
 996
 997                 len = transport->tcp_reclen - transport->tcp_offset;
 998                 memcpy(&my_desc, desc, sizeof(my_desc));
 999                 my_desc.count = len;
1000                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1001                                           &my_desc, xdr_skb_read_bits);
1002                 desc->count -= r;
1003                 desc->offset += r;
1004         } else
1005                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1006                                           desc, xdr_skb_read_bits);
1007
1008         if (r > 0) {
1009                 transport->tcp_copied += r;
1010                 transport->tcp_offset += r;
1011         }
1012         if (r != len) {
1013                 /* Error when copying to the receive buffer,
1014                  * usually because we weren't able to allocate
1015                  * additional buffer pages. All we can do now
1016                  * is turn off TCP_RCV_COPY_DATA, so the request
1017                  * will not receive any additional updates,
1018                  * and time out.
1019                  * Any remaining data from this record will
1020                  * be discarded.
1021                  */
1022                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1023                 dprintk("RPC:       XID %08x truncated request\n",
1024                                 ntohl(transport->tcp_xid));
1025                 dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1026                                 "tcp_offset = %u, tcp_reclen = %u\n",
1027                                 xprt, transport->tcp_copied,
1028                                 transport->tcp_offset, transport->tcp_reclen);
1029                 return;
1030         }
1031
1032         dprintk("RPC:       XID %08x read %Zd bytes\n",
1033                         ntohl(transport->tcp_xid), r);
1034         dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1035                         "tcp_reclen = %u\n", xprt, transport->tcp_copied,
1036                         transport->tcp_offset, transport->tcp_reclen);
1037
1038         if (transport->tcp_copied == req->rq_private_buf.buflen)
1039                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1040         else if (transport->tcp_offset == transport->tcp_reclen) {
1041                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1042                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1043         }
1044 }
1045
1046 /*
1047  * Finds the request corresponding to the RPC xid and invokes the common
1048  * tcp read code to read the data.
1049  */
1050 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1051                                     struct xdr_skb_reader *desc)
1052 {
1053         struct sock_xprt *transport =
1054                                 container_of(xprt, struct sock_xprt, xprt);
1055         struct rpc_rqst *req;
1056
1057         dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1058
1059         /* Find and lock the request corresponding to this xid */
1060         spin_lock(&xprt->transport_lock);
1061         req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1062         if (!req) {
1063                 dprintk("RPC:       XID %08x request not found!\n",
1064                                 ntohl(transport->tcp_xid));
1065                 spin_unlock(&xprt->transport_lock);
1066                 return -1;
1067         }
1068
1069         xs_tcp_read_common(xprt, desc, req);
1070
1071         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1072                 xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1073
1074         spin_unlock(&xprt->transport_lock);
1075         return 0;
1076 }
1077
1078 #if defined(CONFIG_NFS_V4_1)
1079 /*
1080  * Obtains an rpc_rqst previously allocated and invokes the common
1081  * tcp read code to read the data.  The result is placed in the callback
1082  * queue.
1083  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1084  * connection and return -1.
1085  */
1086 static inline int xs_tcp_read_callback(struct rpc_xprt *xprt,
1087                                        struct xdr_skb_reader *desc)
1088 {
1089         struct sock_xprt *transport =
1090                                 container_of(xprt, struct sock_xprt, xprt);
1091         struct rpc_rqst *req;
1092
1093         req = xprt_alloc_bc_request(xprt);
1094         if (req == NULL) {
1095                 printk(KERN_WARNING "Callback slot table overflowed\n");
1096                 xprt_force_disconnect(xprt);
1097                 return -1;
1098         }
1099
1100         req->rq_xid = transport->tcp_xid;
1101         dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1102         xs_tcp_read_common(xprt, desc, req);
1103
1104         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) {
1105                 struct svc_serv *bc_serv = xprt->bc_serv;
1106
1107                 /*
1108                  * Add callback request to callback list.  The callback
1109                  * service sleeps on the sv_cb_waitq waiting for new
1110                  * requests.  Wake it up after adding enqueing the
1111                  * request.
1112                  */
1113                 dprintk("RPC:       add callback request to list\n");
1114                 spin_lock(&bc_serv->sv_cb_lock);
1115                 list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
1116                 spin_unlock(&bc_serv->sv_cb_lock);
1117                 wake_up(&bc_serv->sv_cb_waitq);
1118         }
1119
1120         req->rq_private_buf.len = transport->tcp_copied;
1121
1122         return 0;
1123 }
1124
1125 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1126                                         struct xdr_skb_reader *desc)
1127 {
1128         struct sock_xprt *transport =
1129                                 container_of(xprt, struct sock_xprt, xprt);
1130
1131         return (transport->tcp_flags & TCP_RPC_REPLY) ?
1132                 xs_tcp_read_reply(xprt, desc) :
1133                 xs_tcp_read_callback(xprt, desc);
1134 }
1135 #else
1136 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1137                                         struct xdr_skb_reader *desc)
1138 {
1139         return xs_tcp_read_reply(xprt, desc);
1140 }
1141 #endif /* CONFIG_NFS_V4_1 */
1142
1143 /*
1144  * Read data off the transport.  This can be either an RPC_CALL or an
1145  * RPC_REPLY.  Relay the processing to helper functions.
1146  */
1147 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1148                                     struct xdr_skb_reader *desc)
1149 {
1150         struct sock_xprt *transport =
1151                                 container_of(xprt, struct sock_xprt, xprt);
1152
1153         if (_xs_tcp_read_data(xprt, desc) == 0)
1154                 xs_tcp_check_fraghdr(transport);
1155         else {
1156                 /*
1157                  * The transport_lock protects the request handling.
1158                  * There's no need to hold it to update the tcp_flags.
1159                  */
1160                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1161         }
1162 }
1163
1164 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1165 {
1166         size_t len;
1167
1168         len = transport->tcp_reclen - transport->tcp_offset;
1169         if (len > desc->count)
1170                 len = desc->count;
1171         desc->count -= len;
1172         desc->offset += len;
1173         transport->tcp_offset += len;
1174         dprintk("RPC:       discarded %Zu bytes\n", len);
1175         xs_tcp_check_fraghdr(transport);
1176 }
1177
1178 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1179 {
1180         struct rpc_xprt *xprt = rd_desc->arg.data;
1181         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1182         struct xdr_skb_reader desc = {
1183                 .skb    = skb,
1184                 .offset = offset,
1185                 .count  = len,
1186         };
1187
1188         dprintk("RPC:       xs_tcp_data_recv started\n");
1189         do {
1190                 /* Read in a new fragment marker if necessary */
1191                 /* Can we ever really expect to get completely empty fragments? */
1192                 if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1193                         xs_tcp_read_fraghdr(xprt, &desc);
1194                         continue;
1195                 }
1196                 /* Read in the xid if necessary */
1197                 if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1198                         xs_tcp_read_xid(transport, &desc);
1199                         continue;
1200                 }
1201                 /* Read in the call/reply flag */
1202                 if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1203                         xs_tcp_read_calldir(transport, &desc);
1204                         continue;
1205                 }
1206                 /* Read in the request data */
1207                 if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1208                         xs_tcp_read_data(xprt, &desc);
1209                         continue;
1210                 }
1211                 /* Skip over any trailing bytes on short reads */
1212                 xs_tcp_read_discard(transport, &desc);
1213         } while (desc.count);
1214         dprintk("RPC:       xs_tcp_data_recv done\n");
1215         return len - desc.count;
1216 }
1217
1218 /**
1219  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1220  * @sk: socket with data to read
1221  * @bytes: how much data to read
1222  *
1223  */
1224 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1225 {
1226         struct rpc_xprt *xprt;
1227         read_descriptor_t rd_desc;
1228         int read;
1229
1230         dprintk("RPC:       xs_tcp_data_ready...\n");
1231
1232         read_lock(&sk->sk_callback_lock);
1233         if (!(xprt = xprt_from_sock(sk)))
1234                 goto out;
1235         if (xprt->shutdown)
1236                 goto out;
1237
1238         /* Any data means we had a useful conversation, so
1239          * the we don't need to delay the next reconnect
1240          */
1241         if (xprt->reestablish_timeout)
1242                 xprt->reestablish_timeout = 0;
1243
1244         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1245         rd_desc.arg.data = xprt;
1246         do {
1247                 rd_desc.count = 65536;
1248                 read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1249         } while (read > 0);
1250 out:
1251         read_unlock(&sk->sk_callback_lock);
1252 }
1253
1254 /*
1255  * Do the equivalent of linger/linger2 handling for dealing with
1256  * broken servers that don't close the socket in a timely
1257  * fashion
1258  */
1259 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1260                 unsigned long timeout)
1261 {
1262         struct sock_xprt *transport;
1263
1264         if (xprt_test_and_set_connecting(xprt))
1265                 return;
1266         set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1267         transport = container_of(xprt, struct sock_xprt, xprt);
1268         queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1269                            timeout);
1270 }
1271
1272 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1273 {
1274         struct sock_xprt *transport;
1275
1276         transport = container_of(xprt, struct sock_xprt, xprt);
1277
1278         if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1279             !cancel_delayed_work(&transport->connect_worker))
1280                 return;
1281         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1282         xprt_clear_connecting(xprt);
1283 }
1284
1285 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1286 {
1287         smp_mb__before_clear_bit();
1288         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1289         clear_bit(XPRT_CLOSING, &xprt->state);
1290         smp_mb__after_clear_bit();
1291         /* Mark transport as closed and wake up all pending tasks */
1292         xprt_disconnect_done(xprt);
1293 }
1294
1295 /**
1296  * xs_tcp_state_change - callback to handle TCP socket state changes
1297  * @sk: socket whose state has changed
1298  *
1299  */
1300 static void xs_tcp_state_change(struct sock *sk)
1301 {
1302         struct rpc_xprt *xprt;
1303
1304         read_lock(&sk->sk_callback_lock);
1305         if (!(xprt = xprt_from_sock(sk)))
1306                 goto out;
1307         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1308         dprintk("RPC:       state %x conn %d dead %d zapped %d\n",
1309                         sk->sk_state, xprt_connected(xprt),
1310                         sock_flag(sk, SOCK_DEAD),
1311                         sock_flag(sk, SOCK_ZAPPED));
1312
1313         switch (sk->sk_state) {
1314         case TCP_ESTABLISHED:
1315                 spin_lock_bh(&xprt->transport_lock);
1316                 if (!xprt_test_and_set_connected(xprt)) {
1317                         struct sock_xprt *transport = container_of(xprt,
1318                                         struct sock_xprt, xprt);
1319
1320                         /* Reset TCP record info */
1321                         transport->tcp_offset = 0;
1322                         transport->tcp_reclen = 0;
1323                         transport->tcp_copied = 0;
1324                         transport->tcp_flags =
1325                                 TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1326
1327                         xprt_wake_pending_tasks(xprt, -EAGAIN);
1328                 }
1329                 spin_unlock_bh(&xprt->transport_lock);
1330                 break;
1331         case TCP_FIN_WAIT1:
1332                 /* The client initiated a shutdown of the socket */
1333                 xprt->connect_cookie++;
1334                 xprt->reestablish_timeout = 0;
1335                 set_bit(XPRT_CLOSING, &xprt->state);
1336                 smp_mb__before_clear_bit();
1337                 clear_bit(XPRT_CONNECTED, &xprt->state);
1338                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1339                 smp_mb__after_clear_bit();
1340                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1341                 break;
1342         case TCP_CLOSE_WAIT:
1343                 /* The server initiated a shutdown of the socket */
1344                 xprt_force_disconnect(xprt);
1345         case TCP_SYN_SENT:
1346                 xprt->connect_cookie++;
1347         case TCP_CLOSING:
1348                 /*
1349                  * If the server closed down the connection, make sure that
1350                  * we back off before reconnecting
1351                  */
1352                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1353                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1354                 break;
1355         case TCP_LAST_ACK:
1356                 set_bit(XPRT_CLOSING, &xprt->state);
1357                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1358                 smp_mb__before_clear_bit();
1359                 clear_bit(XPRT_CONNECTED, &xprt->state);
1360                 smp_mb__after_clear_bit();
1361                 break;
1362         case TCP_CLOSE:
1363                 xs_tcp_cancel_linger_timeout(xprt);
1364                 xs_sock_mark_closed(xprt);
1365         }
1366  out:
1367         read_unlock(&sk->sk_callback_lock);
1368 }
1369
1370 /**
1371  * xs_error_report - callback mainly for catching socket errors
1372  * @sk: socket
1373  */
1374 static void xs_error_report(struct sock *sk)
1375 {
1376         struct rpc_xprt *xprt;
1377
1378         read_lock(&sk->sk_callback_lock);
1379         if (!(xprt = xprt_from_sock(sk)))
1380                 goto out;
1381         dprintk("RPC:       %s client %p...\n"
1382                         "RPC:       error %d\n",
1383                         __func__, xprt, sk->sk_err);
1384         xprt_wake_pending_tasks(xprt, -EAGAIN);
1385 out:
1386         read_unlock(&sk->sk_callback_lock);
1387 }
1388
1389 static void xs_write_space(struct sock *sk)
1390 {
1391         struct socket *sock;
1392         struct rpc_xprt *xprt;
1393
1394         if (unlikely(!(sock = sk->sk_socket)))
1395                 return;
1396         clear_bit(SOCK_NOSPACE, &sock->flags);
1397
1398         if (unlikely(!(xprt = xprt_from_sock(sk))))
1399                 return;
1400         if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1401                 return;
1402
1403         xprt_write_space(xprt);
1404 }
1405
1406 /**
1407  * xs_udp_write_space - callback invoked when socket buffer space
1408  *                             becomes available
1409  * @sk: socket whose state has changed
1410  *
1411  * Called when more output buffer space is available for this socket.
1412  * We try not to wake our writers until they can make "significant"
1413  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1414  * with a bunch of small requests.
1415  */
1416 static void xs_udp_write_space(struct sock *sk)
1417 {
1418         read_lock(&sk->sk_callback_lock);
1419
1420         /* from net/core/sock.c:sock_def_write_space */
1421         if (sock_writeable(sk))
1422                 xs_write_space(sk);
1423
1424         read_unlock(&sk->sk_callback_lock);
1425 }
1426
1427 /**
1428  * xs_tcp_write_space - callback invoked when socket buffer space
1429  *                             becomes available
1430  * @sk: socket whose state has changed
1431  *
1432  * Called when more output buffer space is available for this socket.
1433  * We try not to wake our writers until they can make "significant"
1434  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1435  * with a bunch of small requests.
1436  */
1437 static void xs_tcp_write_space(struct sock *sk)
1438 {
1439         read_lock(&sk->sk_callback_lock);
1440
1441         /* from net/core/stream.c:sk_stream_write_space */
1442         if (sk_stream_wspace(sk) >= sk_stream_min_wspace(sk))
1443                 xs_write_space(sk);
1444
1445         read_unlock(&sk->sk_callback_lock);
1446 }
1447
1448 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1449 {
1450         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1451         struct sock *sk = transport->inet;
1452
1453         if (transport->rcvsize) {
1454                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1455                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1456         }
1457         if (transport->sndsize) {
1458                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1459                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1460                 sk->sk_write_space(sk);
1461         }
1462 }
1463
1464 /**
1465  * xs_udp_set_buffer_size - set send and receive limits
1466  * @xprt: generic transport
1467  * @sndsize: requested size of send buffer, in bytes
1468  * @rcvsize: requested size of receive buffer, in bytes
1469  *
1470  * Set socket send and receive buffer size limits.
1471  */
1472 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1473 {
1474         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1475
1476         transport->sndsize = 0;
1477         if (sndsize)
1478                 transport->sndsize = sndsize + 1024;
1479         transport->rcvsize = 0;
1480         if (rcvsize)
1481                 transport->rcvsize = rcvsize + 1024;
1482
1483         xs_udp_do_set_buffer_size(xprt);
1484 }
1485
1486 /**
1487  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1488  * @task: task that timed out
1489  *
1490  * Adjust the congestion window after a retransmit timeout has occurred.
1491  */
1492 static void xs_udp_timer(struct rpc_task *task)
1493 {
1494         xprt_adjust_cwnd(task, -ETIMEDOUT);
1495 }
1496
1497 static unsigned short xs_get_random_port(void)
1498 {
1499         unsigned short range = xprt_max_resvport - xprt_min_resvport;
1500         unsigned short rand = (unsigned short) net_random() % range;
1501         return rand + xprt_min_resvport;
1502 }
1503
1504 /**
1505  * xs_set_port - reset the port number in the remote endpoint address
1506  * @xprt: generic transport
1507  * @port: new port number
1508  *
1509  */
1510 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1511 {
1512         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1513
1514         rpc_set_port(xs_addr(xprt), port);
1515         xs_update_peer_port(xprt);
1516 }
1517
1518 static unsigned short xs_get_srcport(struct sock_xprt *transport, struct socket *sock)
1519 {
1520         unsigned short port = transport->srcport;
1521
1522         if (port == 0 && transport->xprt.resvport)
1523                 port = xs_get_random_port();
1524         return port;
1525 }
1526
1527 static unsigned short xs_next_srcport(struct sock_xprt *transport, struct socket *sock, unsigned short port)
1528 {
1529         if (transport->srcport != 0)
1530                 transport->srcport = 0;
1531         if (!transport->xprt.resvport)
1532                 return 0;
1533         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1534                 return xprt_max_resvport;
1535         return --port;
1536 }
1537
1538 static int xs_bind4(struct sock_xprt *transport, struct socket *sock)
1539 {
1540         struct sockaddr_in myaddr = {
1541                 .sin_family = AF_INET,
1542         };
1543         struct sockaddr_in *sa;
1544         int err, nloop = 0;
1545         unsigned short port = xs_get_srcport(transport, sock);
1546         unsigned short last;
1547
1548         sa = (struct sockaddr_in *)&transport->srcaddr;
1549         myaddr.sin_addr = sa->sin_addr;
1550         do {
1551                 myaddr.sin_port = htons(port);
1552                 err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1553                                                 sizeof(myaddr));
1554                 if (port == 0)
1555                         break;
1556                 if (err == 0) {
1557                         transport->srcport = port;
1558                         break;
1559                 }
1560                 last = port;
1561                 port = xs_next_srcport(transport, sock, port);
1562                 if (port > last)
1563                         nloop++;
1564         } while (err == -EADDRINUSE && nloop != 2);
1565         dprintk("RPC:       %s %pI4:%u: %s (%d)\n",
1566                         __func__, &myaddr.sin_addr,
1567                         port, err ? "failed" : "ok", err);
1568         return err;
1569 }
1570
1571 static int xs_bind6(struct sock_xprt *transport, struct socket *sock)
1572 {
1573         struct sockaddr_in6 myaddr = {
1574                 .sin6_family = AF_INET6,
1575         };
1576         struct sockaddr_in6 *sa;
1577         int err, nloop = 0;
1578         unsigned short port = xs_get_srcport(transport, sock);
1579         unsigned short last;
1580
1581         sa = (struct sockaddr_in6 *)&transport->srcaddr;
1582         myaddr.sin6_addr = sa->sin6_addr;
1583         do {
1584                 myaddr.sin6_port = htons(port);
1585                 err = kernel_bind(sock, (struct sockaddr *) &myaddr,
1586                                                 sizeof(myaddr));
1587                 if (port == 0)
1588                         break;
1589                 if (err == 0) {
1590                         transport->srcport = port;
1591                         break;
1592                 }
1593                 last = port;
1594                 port = xs_next_srcport(transport, sock, port);
1595                 if (port > last)
1596                         nloop++;
1597         } while (err == -EADDRINUSE && nloop != 2);
1598         dprintk("RPC:       xs_bind6 %pI6:%u: %s (%d)\n",
1599                 &myaddr.sin6_addr, port, err ? "failed" : "ok", err);
1600         return err;
1601 }
1602
1603 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1604 static struct lock_class_key xs_key[2];
1605 static struct lock_class_key xs_slock_key[2];
1606
1607 static inline void xs_reclassify_socket4(struct socket *sock)
1608 {
1609         struct sock *sk = sock->sk;
1610
1611         BUG_ON(sock_owned_by_user(sk));
1612         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1613                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1614 }
1615
1616 static inline void xs_reclassify_socket6(struct socket *sock)
1617 {
1618         struct sock *sk = sock->sk;
1619
1620         BUG_ON(sock_owned_by_user(sk));
1621         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1622                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1623 }
1624 #else
1625 static inline void xs_reclassify_socket4(struct socket *sock)
1626 {
1627 }
1628
1629 static inline void xs_reclassify_socket6(struct socket *sock)
1630 {
1631 }
1632 #endif
1633
1634 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1635 {
1636         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1637
1638         if (!transport->inet) {
1639                 struct sock *sk = sock->sk;
1640
1641                 write_lock_bh(&sk->sk_callback_lock);
1642
1643                 xs_save_old_callbacks(transport, sk);
1644
1645                 sk->sk_user_data = xprt;
1646                 sk->sk_data_ready = xs_udp_data_ready;
1647                 sk->sk_write_space = xs_udp_write_space;
1648                 sk->sk_error_report = xs_error_report;
1649                 sk->sk_no_check = UDP_CSUM_NORCV;
1650                 sk->sk_allocation = GFP_ATOMIC;
1651
1652                 xprt_set_connected(xprt);
1653
1654                 /* Reset to new socket */
1655                 transport->sock = sock;
1656                 transport->inet = sk;
1657
1658                 write_unlock_bh(&sk->sk_callback_lock);
1659         }
1660         xs_udp_do_set_buffer_size(xprt);
1661 }
1662
1663 /**
1664  * xs_udp_connect_worker4 - set up a UDP socket
1665  * @work: RPC transport to connect
1666  *
1667  * Invoked by a work queue tasklet.
1668  */
1669 static void xs_udp_connect_worker4(struct work_struct *work)
1670 {
1671         struct sock_xprt *transport =
1672                 container_of(work, struct sock_xprt, connect_worker.work);
1673         struct rpc_xprt *xprt = &transport->xprt;
1674         struct socket *sock = transport->sock;
1675         int err, status = -EIO;
1676
1677         if (xprt->shutdown)
1678                 goto out;
1679
1680         /* Start by resetting any existing state */
1681         xs_reset_transport(transport);
1682
1683         err = sock_create_kern(PF_INET, SOCK_DGRAM, IPPROTO_UDP, &sock);
1684         if (err < 0) {
1685                 dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1686                 goto out;
1687         }
1688         xs_reclassify_socket4(sock);
1689
1690         if (xs_bind4(transport, sock)) {
1691                 sock_release(sock);
1692                 goto out;
1693         }
1694
1695         dprintk("RPC:       worker connecting xprt %p via %s to "
1696                                 "%s (port %s)\n", xprt,
1697                         xprt->address_strings[RPC_DISPLAY_PROTO],
1698                         xprt->address_strings[RPC_DISPLAY_ADDR],
1699                         xprt->address_strings[RPC_DISPLAY_PORT]);
1700
1701         xs_udp_finish_connecting(xprt, sock);
1702         status = 0;
1703 out:
1704         xprt_clear_connecting(xprt);
1705         xprt_wake_pending_tasks(xprt, status);
1706 }
1707
1708 /**
1709  * xs_udp_connect_worker6 - set up a UDP socket
1710  * @work: RPC transport to connect
1711  *
1712  * Invoked by a work queue tasklet.
1713  */
1714 static void xs_udp_connect_worker6(struct work_struct *work)
1715 {
1716         struct sock_xprt *transport =
1717                 container_of(work, struct sock_xprt, connect_worker.work);
1718         struct rpc_xprt *xprt = &transport->xprt;
1719         struct socket *sock = transport->sock;
1720         int err, status = -EIO;
1721
1722         if (xprt->shutdown)
1723                 goto out;
1724
1725         /* Start by resetting any existing state */
1726         xs_reset_transport(transport);
1727
1728         err = sock_create_kern(PF_INET6, SOCK_DGRAM, IPPROTO_UDP, &sock);
1729         if (err < 0) {
1730                 dprintk("RPC:       can't create UDP transport socket (%d).\n", -err);
1731                 goto out;
1732         }
1733         xs_reclassify_socket6(sock);
1734
1735         if (xs_bind6(transport, sock) < 0) {
1736                 sock_release(sock);
1737                 goto out;
1738         }
1739
1740         dprintk("RPC:       worker connecting xprt %p via %s to "
1741                                 "%s (port %s)\n", xprt,
1742                         xprt->address_strings[RPC_DISPLAY_PROTO],
1743                         xprt->address_strings[RPC_DISPLAY_ADDR],
1744                         xprt->address_strings[RPC_DISPLAY_PORT]);
1745
1746         xs_udp_finish_connecting(xprt, sock);
1747         status = 0;
1748 out:
1749         xprt_clear_connecting(xprt);
1750         xprt_wake_pending_tasks(xprt, status);
1751 }
1752
1753 /*
1754  * We need to preserve the port number so the reply cache on the server can
1755  * find our cached RPC replies when we get around to reconnecting.
1756  */
1757 static void xs_abort_connection(struct rpc_xprt *xprt, struct sock_xprt *transport)
1758 {
1759         int result;
1760         struct sockaddr any;
1761
1762         dprintk("RPC:       disconnecting xprt %p to reuse port\n", xprt);
1763
1764         /*
1765          * Disconnect the transport socket by doing a connect operation
1766          * with AF_UNSPEC.  This should return immediately...
1767          */
1768         memset(&any, 0, sizeof(any));
1769         any.sa_family = AF_UNSPEC;
1770         result = kernel_connect(transport->sock, &any, sizeof(any), 0);
1771         if (!result)
1772                 xs_sock_mark_closed(xprt);
1773         else
1774                 dprintk("RPC:       AF_UNSPEC connect return code %d\n",
1775                                 result);
1776 }
1777
1778 static void xs_tcp_reuse_connection(struct rpc_xprt *xprt, struct sock_xprt *transport)
1779 {
1780         unsigned int state = transport->inet->sk_state;
1781
1782         if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED)
1783                 return;
1784         if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT))
1785                 return;
1786         xs_abort_connection(xprt, transport);
1787 }
1788
1789 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
1790 {
1791         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1792
1793         if (!transport->inet) {
1794                 struct sock *sk = sock->sk;
1795
1796                 write_lock_bh(&sk->sk_callback_lock);
1797
1798                 xs_save_old_callbacks(transport, sk);
1799
1800                 sk->sk_user_data = xprt;
1801                 sk->sk_data_ready = xs_tcp_data_ready;
1802                 sk->sk_state_change = xs_tcp_state_change;
1803                 sk->sk_write_space = xs_tcp_write_space;
1804                 sk->sk_error_report = xs_error_report;
1805                 sk->sk_allocation = GFP_ATOMIC;
1806
1807                 /* socket options */
1808                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
1809                 sock_reset_flag(sk, SOCK_LINGER);
1810                 tcp_sk(sk)->linger2 = 0;
1811                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
1812
1813                 xprt_clear_connected(xprt);
1814
1815                 /* Reset to new socket */
1816                 transport->sock = sock;
1817                 transport->inet = sk;
1818
1819                 write_unlock_bh(&sk->sk_callback_lock);
1820         }
1821
1822         if (!xprt_bound(xprt))
1823                 return -ENOTCONN;
1824
1825         /* Tell the socket layer to start connecting... */
1826         xprt->stat.connect_count++;
1827         xprt->stat.connect_start = jiffies;
1828         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
1829 }
1830
1831 /**
1832  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
1833  * @xprt: RPC transport to connect
1834  * @transport: socket transport to connect
1835  * @create_sock: function to create a socket of the correct type
1836  *
1837  * Invoked by a work queue tasklet.
1838  */
1839 static void xs_tcp_setup_socket(struct rpc_xprt *xprt,
1840                 struct sock_xprt *transport,
1841                 struct socket *(*create_sock)(struct rpc_xprt *,
1842                         struct sock_xprt *))
1843 {
1844         struct socket *sock = transport->sock;
1845         int status = -EIO;
1846
1847         if (xprt->shutdown)
1848                 goto out;
1849
1850         if (!sock) {
1851                 clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1852                 sock = create_sock(xprt, transport);
1853                 if (IS_ERR(sock)) {
1854                         status = PTR_ERR(sock);
1855                         goto out;
1856                 }
1857         } else {
1858                 int abort_and_exit;
1859
1860                 abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
1861                                 &xprt->state);
1862                 /* "close" the socket, preserving the local port */
1863                 xs_tcp_reuse_connection(xprt, transport);
1864
1865                 if (abort_and_exit)
1866                         goto out_eagain;
1867         }
1868
1869         dprintk("RPC:       worker connecting xprt %p via %s to "
1870                                 "%s (port %s)\n", xprt,
1871                         xprt->address_strings[RPC_DISPLAY_PROTO],
1872                         xprt->address_strings[RPC_DISPLAY_ADDR],
1873                         xprt->address_strings[RPC_DISPLAY_PORT]);
1874
1875         status = xs_tcp_finish_connecting(xprt, sock);
1876         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
1877                         xprt, -status, xprt_connected(xprt),
1878                         sock->sk->sk_state);
1879         switch (status) {
1880         default:
1881                 printk("%s: connect returned unhandled error %d\n",
1882                         __func__, status);
1883         case -EADDRNOTAVAIL:
1884                 /* We're probably in TIME_WAIT. Get rid of existing socket,
1885                  * and retry
1886                  */
1887                 set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1888                 xprt_force_disconnect(xprt);
1889                 break;
1890         case -ECONNREFUSED:
1891         case -ECONNRESET:
1892         case -ENETUNREACH:
1893                 /* retry with existing socket, after a delay */
1894         case 0:
1895         case -EINPROGRESS:
1896         case -EALREADY:
1897                 xprt_clear_connecting(xprt);
1898                 return;
1899         case -EINVAL:
1900                 /* Happens, for instance, if the user specified a link
1901                  * local IPv6 address without a scope-id.
1902                  */
1903                 goto out;
1904         }
1905 out_eagain:
1906         status = -EAGAIN;
1907 out:
1908         xprt_clear_connecting(xprt);
1909         xprt_wake_pending_tasks(xprt, status);
1910 }
1911
1912 static struct socket *xs_create_tcp_sock4(struct rpc_xprt *xprt,
1913                 struct sock_xprt *transport)
1914 {
1915         struct socket *sock;
1916         int err;
1917
1918         /* start from scratch */
1919         err = sock_create_kern(PF_INET, SOCK_STREAM, IPPROTO_TCP, &sock);
1920         if (err < 0) {
1921                 dprintk("RPC:       can't create TCP transport socket (%d).\n",
1922                                 -err);
1923                 goto out_err;
1924         }
1925         xs_reclassify_socket4(sock);
1926
1927         if (xs_bind4(transport, sock) < 0) {
1928                 sock_release(sock);
1929                 goto out_err;
1930         }
1931         return sock;
1932 out_err:
1933         return ERR_PTR(-EIO);
1934 }
1935
1936 /**
1937  * xs_tcp_connect_worker4 - connect a TCP socket to a remote endpoint
1938  * @work: RPC transport to connect
1939  *
1940  * Invoked by a work queue tasklet.
1941  */
1942 static void xs_tcp_connect_worker4(struct work_struct *work)
1943 {
1944         struct sock_xprt *transport =
1945                 container_of(work, struct sock_xprt, connect_worker.work);
1946         struct rpc_xprt *xprt = &transport->xprt;
1947
1948         xs_tcp_setup_socket(xprt, transport, xs_create_tcp_sock4);
1949 }
1950
1951 static struct socket *xs_create_tcp_sock6(struct rpc_xprt *xprt,
1952                 struct sock_xprt *transport)
1953 {
1954         struct socket *sock;
1955         int err;
1956
1957         /* start from scratch */
1958         err = sock_create_kern(PF_INET6, SOCK_STREAM, IPPROTO_TCP, &sock);
1959         if (err < 0) {
1960                 dprintk("RPC:       can't create TCP transport socket (%d).\n",
1961                                 -err);
1962                 goto out_err;
1963         }
1964         xs_reclassify_socket6(sock);
1965
1966         if (xs_bind6(transport, sock) < 0) {
1967                 sock_release(sock);
1968                 goto out_err;
1969         }
1970         return sock;
1971 out_err:
1972         return ERR_PTR(-EIO);
1973 }
1974
1975 /**
1976  * xs_tcp_connect_worker6 - connect a TCP socket to a remote endpoint
1977  * @work: RPC transport to connect
1978  *
1979  * Invoked by a work queue tasklet.
1980  */
1981 static void xs_tcp_connect_worker6(struct work_struct *work)
1982 {
1983         struct sock_xprt *transport =
1984                 container_of(work, struct sock_xprt, connect_worker.work);
1985         struct rpc_xprt *xprt = &transport->xprt;
1986
1987         xs_tcp_setup_socket(xprt, transport, xs_create_tcp_sock6);
1988 }
1989
1990 /**
1991  * xs_connect - connect a socket to a remote endpoint
1992  * @task: address of RPC task that manages state of connect request
1993  *
1994  * TCP: If the remote end dropped the connection, delay reconnecting.
1995  *
1996  * UDP socket connects are synchronous, but we use a work queue anyway
1997  * to guarantee that even unprivileged user processes can set up a
1998  * socket on a privileged port.
1999  *
2000  * If a UDP socket connect fails, the delay behavior here prevents
2001  * retry floods (hard mounts).
2002  */
2003 static void xs_connect(struct rpc_task *task)
2004 {
2005         struct rpc_xprt *xprt = task->tk_xprt;
2006         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2007
2008         if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2009                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2010                                 "seconds\n",
2011                                 xprt, xprt->reestablish_timeout / HZ);
2012                 queue_delayed_work(rpciod_workqueue,
2013                                    &transport->connect_worker,
2014                                    xprt->reestablish_timeout);
2015                 xprt->reestablish_timeout <<= 1;
2016                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2017                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2018                 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2019                         xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2020         } else {
2021                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2022                 queue_delayed_work(rpciod_workqueue,
2023                                    &transport->connect_worker, 0);
2024         }
2025 }
2026
2027 /**
2028  * xs_udp_print_stats - display UDP socket-specifc stats
2029  * @xprt: rpc_xprt struct containing statistics
2030  * @seq: output file
2031  *
2032  */
2033 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2034 {
2035         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2036
2037         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %Lu %Lu\n",
2038                         transport->srcport,
2039                         xprt->stat.bind_count,
2040                         xprt->stat.sends,
2041                         xprt->stat.recvs,
2042                         xprt->stat.bad_xids,
2043                         xprt->stat.req_u,
2044                         xprt->stat.bklog_u);
2045 }
2046
2047 /**
2048  * xs_tcp_print_stats - display TCP socket-specifc stats
2049  * @xprt: rpc_xprt struct containing statistics
2050  * @seq: output file
2051  *
2052  */
2053 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2054 {
2055         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2056         long idle_time = 0;
2057
2058         if (xprt_connected(xprt))
2059                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2060
2061         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu %Lu %Lu\n",
2062                         transport->srcport,
2063                         xprt->stat.bind_count,
2064                         xprt->stat.connect_count,
2065                         xprt->stat.connect_time,
2066                         idle_time,
2067                         xprt->stat.sends,
2068                         xprt->stat.recvs,
2069                         xprt->stat.bad_xids,
2070                         xprt->stat.req_u,
2071                         xprt->stat.bklog_u);
2072 }
2073
2074 /*
2075  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2076  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2077  * to use the server side send routines.
2078  */
2079 static void *bc_malloc(struct rpc_task *task, size_t size)
2080 {
2081         struct page *page;
2082         struct rpc_buffer *buf;
2083
2084         BUG_ON(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2085         page = alloc_page(GFP_KERNEL);
2086
2087         if (!page)
2088                 return NULL;
2089
2090         buf = page_address(page);
2091         buf->len = PAGE_SIZE;
2092
2093         return buf->data;
2094 }
2095
2096 /*
2097  * Free the space allocated in the bc_alloc routine
2098  */
2099 static void bc_free(void *buffer)
2100 {
2101         struct rpc_buffer *buf;
2102
2103         if (!buffer)
2104                 return;
2105
2106         buf = container_of(buffer, struct rpc_buffer, data);
2107         free_page((unsigned long)buf);
2108 }
2109
2110 /*
2111  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2112  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2113  */
2114 static int bc_sendto(struct rpc_rqst *req)
2115 {
2116         int len;
2117         struct xdr_buf *xbufp = &req->rq_snd_buf;
2118         struct rpc_xprt *xprt = req->rq_xprt;
2119         struct sock_xprt *transport =
2120                                 container_of(xprt, struct sock_xprt, xprt);
2121         struct socket *sock = transport->sock;
2122         unsigned long headoff;
2123         unsigned long tailoff;
2124
2125         /*
2126          * Set up the rpc header and record marker stuff
2127          */
2128         xs_encode_tcp_record_marker(xbufp);
2129
2130         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2131         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2132         len = svc_send_common(sock, xbufp,
2133                               virt_to_page(xbufp->head[0].iov_base), headoff,
2134                               xbufp->tail[0].iov_base, tailoff);
2135
2136         if (len != xbufp->len) {
2137                 printk(KERN_NOTICE "Error sending entire callback!\n");
2138                 len = -EAGAIN;
2139         }
2140
2141         return len;
2142 }
2143
2144 /*
2145  * The send routine. Borrows from svc_send
2146  */
2147 static int bc_send_request(struct rpc_task *task)
2148 {
2149         struct rpc_rqst *req = task->tk_rqstp;
2150         struct svc_xprt *xprt;
2151         struct svc_sock         *svsk;
2152         u32                     len;
2153
2154         dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2155         /*
2156          * Get the server socket associated with this callback xprt
2157          */
2158         xprt = req->rq_xprt->bc_xprt;
2159         svsk = container_of(xprt, struct svc_sock, sk_xprt);
2160
2161         /*
2162          * Grab the mutex to serialize data as the connection is shared
2163          * with the fore channel
2164          */
2165         if (!mutex_trylock(&xprt->xpt_mutex)) {
2166                 rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2167                 if (!mutex_trylock(&xprt->xpt_mutex))
2168                         return -EAGAIN;
2169                 rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2170         }
2171         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2172                 len = -ENOTCONN;
2173         else
2174                 len = bc_sendto(req);
2175         mutex_unlock(&xprt->xpt_mutex);
2176
2177         if (len > 0)
2178                 len = 0;
2179
2180         return len;
2181 }
2182
2183 /*
2184  * The close routine. Since this is client initiated, we do nothing
2185  */
2186
2187 static void bc_close(struct rpc_xprt *xprt)
2188 {
2189 }
2190
2191 /*
2192  * The xprt destroy routine. Again, because this connection is client
2193  * initiated, we do nothing
2194  */
2195
2196 static void bc_destroy(struct rpc_xprt *xprt)
2197 {
2198 }
2199
2200 static struct rpc_xprt_ops xs_udp_ops = {
2201         .set_buffer_size        = xs_udp_set_buffer_size,
2202         .reserve_xprt           = xprt_reserve_xprt_cong,
2203         .release_xprt           = xprt_release_xprt_cong,
2204         .rpcbind                = rpcb_getport_async,
2205         .set_port               = xs_set_port,
2206         .connect                = xs_connect,
2207         .buf_alloc              = rpc_malloc,
2208         .buf_free               = rpc_free,
2209         .send_request           = xs_udp_send_request,
2210         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
2211         .timer                  = xs_udp_timer,
2212         .release_request        = xprt_release_rqst_cong,
2213         .close                  = xs_close,
2214         .destroy                = xs_destroy,
2215         .print_stats            = xs_udp_print_stats,
2216 };
2217
2218 static struct rpc_xprt_ops xs_tcp_ops = {
2219         .reserve_xprt           = xprt_reserve_xprt,
2220         .release_xprt           = xs_tcp_release_xprt,
2221         .rpcbind                = rpcb_getport_async,
2222         .set_port               = xs_set_port,
2223         .connect                = xs_connect,
2224         .buf_alloc              = rpc_malloc,
2225         .buf_free               = rpc_free,
2226         .send_request           = xs_tcp_send_request,
2227         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2228         .close                  = xs_tcp_close,
2229         .destroy                = xs_destroy,
2230         .print_stats            = xs_tcp_print_stats,
2231 };
2232
2233 /*
2234  * The rpc_xprt_ops for the server backchannel
2235  */
2236
2237 static struct rpc_xprt_ops bc_tcp_ops = {
2238         .reserve_xprt           = xprt_reserve_xprt,
2239         .release_xprt           = xprt_release_xprt,
2240         .buf_alloc              = bc_malloc,
2241         .buf_free               = bc_free,
2242         .send_request           = bc_send_request,
2243         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2244         .close                  = bc_close,
2245         .destroy                = bc_destroy,
2246         .print_stats            = xs_tcp_print_stats,
2247 };
2248
2249 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2250                                       unsigned int slot_table_size)
2251 {
2252         struct rpc_xprt *xprt;
2253         struct sock_xprt *new;
2254
2255         if (args->addrlen > sizeof(xprt->addr)) {
2256                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2257                 return ERR_PTR(-EBADF);
2258         }
2259
2260         new = kzalloc(sizeof(*new), GFP_KERNEL);
2261         if (new == NULL) {
2262                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2263                                 "rpc_xprt\n");
2264                 return ERR_PTR(-ENOMEM);
2265         }
2266         xprt = &new->xprt;
2267
2268         xprt->max_reqs = slot_table_size;
2269         xprt->slot = kcalloc(xprt->max_reqs, sizeof(struct rpc_rqst), GFP_KERNEL);
2270         if (xprt->slot == NULL) {
2271                 kfree(xprt);
2272                 dprintk("RPC:       xs_setup_xprt: couldn't allocate slot "
2273                                 "table\n");
2274                 return ERR_PTR(-ENOMEM);
2275         }
2276
2277         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2278         xprt->addrlen = args->addrlen;
2279         if (args->srcaddr)
2280                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2281
2282         return xprt;
2283 }
2284
2285 static const struct rpc_timeout xs_udp_default_timeout = {
2286         .to_initval = 5 * HZ,
2287         .to_maxval = 30 * HZ,
2288         .to_increment = 5 * HZ,
2289         .to_retries = 5,
2290 };
2291
2292 /**
2293  * xs_setup_udp - Set up transport to use a UDP socket
2294  * @args: rpc transport creation arguments
2295  *
2296  */
2297 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2298 {
2299         struct sockaddr *addr = args->dstaddr;
2300         struct rpc_xprt *xprt;
2301         struct sock_xprt *transport;
2302         struct rpc_xprt *ret;
2303
2304         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries);
2305         if (IS_ERR(xprt))
2306                 return xprt;
2307         transport = container_of(xprt, struct sock_xprt, xprt);
2308
2309         xprt->prot = IPPROTO_UDP;
2310         xprt->tsh_size = 0;
2311         /* XXX: header size can vary due to auth type, IPv6, etc. */
2312         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2313
2314         xprt->bind_timeout = XS_BIND_TO;
2315         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2316         xprt->idle_timeout = XS_IDLE_DISC_TO;
2317
2318         xprt->ops = &xs_udp_ops;
2319
2320         xprt->timeout = &xs_udp_default_timeout;
2321
2322         switch (addr->sa_family) {
2323         case AF_INET:
2324                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2325                         xprt_set_bound(xprt);
2326
2327                 INIT_DELAYED_WORK(&transport->connect_worker,
2328                                         xs_udp_connect_worker4);
2329                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2330                 break;
2331         case AF_INET6:
2332                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2333                         xprt_set_bound(xprt);
2334
2335                 INIT_DELAYED_WORK(&transport->connect_worker,
2336                                         xs_udp_connect_worker6);
2337                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2338                 break;
2339         default:
2340                 ret = ERR_PTR(-EAFNOSUPPORT);
2341                 goto out_err;
2342         }
2343
2344         if (xprt_bound(xprt))
2345                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2346                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2347                                 xprt->address_strings[RPC_DISPLAY_PORT],
2348                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2349         else
2350                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2351                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2352                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2353
2354         if (try_module_get(THIS_MODULE))
2355                 return xprt;
2356         ret = ERR_PTR(-EINVAL);
2357 out_err:
2358         kfree(xprt->slot);
2359         kfree(xprt);
2360         return ret;
2361 }
2362
2363 static const struct rpc_timeout xs_tcp_default_timeout = {
2364         .to_initval = 60 * HZ,
2365         .to_maxval = 60 * HZ,
2366         .to_retries = 2,
2367 };
2368
2369 /**
2370  * xs_setup_tcp - Set up transport to use a TCP socket
2371  * @args: rpc transport creation arguments
2372  *
2373  */
2374 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2375 {
2376         struct sockaddr *addr = args->dstaddr;
2377         struct rpc_xprt *xprt;
2378         struct sock_xprt *transport;
2379         struct rpc_xprt *ret;
2380
2381         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
2382         if (IS_ERR(xprt))
2383                 return xprt;
2384         transport = container_of(xprt, struct sock_xprt, xprt);
2385
2386         xprt->prot = IPPROTO_TCP;
2387         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2388         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2389
2390         xprt->bind_timeout = XS_BIND_TO;
2391         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2392         xprt->idle_timeout = XS_IDLE_DISC_TO;
2393
2394         xprt->ops = &xs_tcp_ops;
2395         xprt->timeout = &xs_tcp_default_timeout;
2396
2397         switch (addr->sa_family) {
2398         case AF_INET:
2399                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2400                         xprt_set_bound(xprt);
2401
2402                 INIT_DELAYED_WORK(&transport->connect_worker,
2403                                         xs_tcp_connect_worker4);
2404                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2405                 break;
2406         case AF_INET6:
2407                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2408                         xprt_set_bound(xprt);
2409
2410                 INIT_DELAYED_WORK(&transport->connect_worker,
2411                                         xs_tcp_connect_worker6);
2412                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2413                 break;
2414         default:
2415                 ret = ERR_PTR(-EAFNOSUPPORT);
2416                 goto out_err;
2417         }
2418
2419         if (xprt_bound(xprt))
2420                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2421                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2422                                 xprt->address_strings[RPC_DISPLAY_PORT],
2423                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2424         else
2425                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2426                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2427                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2428
2429
2430         if (try_module_get(THIS_MODULE))
2431                 return xprt;
2432         ret = ERR_PTR(-EINVAL);
2433 out_err:
2434         kfree(xprt->slot);
2435         kfree(xprt);
2436         return ret;
2437 }
2438
2439 /**
2440  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2441  * @args: rpc transport creation arguments
2442  *
2443  */
2444 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2445 {
2446         struct sockaddr *addr = args->dstaddr;
2447         struct rpc_xprt *xprt;
2448         struct sock_xprt *transport;
2449         struct svc_sock *bc_sock;
2450         struct rpc_xprt *ret;
2451
2452         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries);
2453         if (IS_ERR(xprt))
2454                 return xprt;
2455         transport = container_of(xprt, struct sock_xprt, xprt);
2456
2457         xprt->prot = IPPROTO_TCP;
2458         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2459         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2460         xprt->timeout = &xs_tcp_default_timeout;
2461
2462         /* backchannel */
2463         xprt_set_bound(xprt);
2464         xprt->bind_timeout = 0;
2465         xprt->reestablish_timeout = 0;
2466         xprt->idle_timeout = 0;
2467
2468         /*
2469          * The backchannel uses the same socket connection as the
2470          * forechannel
2471          */
2472         xprt->bc_xprt = args->bc_xprt;
2473         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2474         bc_sock->sk_bc_xprt = xprt;
2475         transport->sock = bc_sock->sk_sock;
2476         transport->inet = bc_sock->sk_sk;
2477
2478         xprt->ops = &bc_tcp_ops;
2479
2480         switch (addr->sa_family) {
2481         case AF_INET:
2482                 xs_format_peer_addresses(xprt, "tcp",
2483                                          RPCBIND_NETID_TCP);
2484                 break;
2485         case AF_INET6:
2486                 xs_format_peer_addresses(xprt, "tcp",
2487                                    RPCBIND_NETID_TCP6);
2488                 break;
2489         default:
2490                 ret = ERR_PTR(-EAFNOSUPPORT);
2491                 goto out_err;
2492         }
2493
2494         if (xprt_bound(xprt))
2495                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2496                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2497                                 xprt->address_strings[RPC_DISPLAY_PORT],
2498                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2499         else
2500                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2501                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2502                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2503
2504         /*
2505          * Since we don't want connections for the backchannel, we set
2506          * the xprt status to connected
2507          */
2508         xprt_set_connected(xprt);
2509
2510
2511         if (try_module_get(THIS_MODULE))
2512                 return xprt;
2513         ret = ERR_PTR(-EINVAL);
2514 out_err:
2515         kfree(xprt->slot);
2516         kfree(xprt);
2517         return ret;
2518 }
2519
2520 static struct xprt_class        xs_udp_transport = {
2521         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
2522         .name           = "udp",
2523         .owner          = THIS_MODULE,
2524         .ident          = XPRT_TRANSPORT_UDP,
2525         .setup          = xs_setup_udp,
2526 };
2527
2528 static struct xprt_class        xs_tcp_transport = {
2529         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
2530         .name           = "tcp",
2531         .owner          = THIS_MODULE,
2532         .ident          = XPRT_TRANSPORT_TCP,
2533         .setup          = xs_setup_tcp,
2534 };
2535
2536 static struct xprt_class        xs_bc_tcp_transport = {
2537         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
2538         .name           = "tcp NFSv4.1 backchannel",
2539         .owner          = THIS_MODULE,
2540         .ident          = XPRT_TRANSPORT_BC_TCP,
2541         .setup          = xs_setup_bc_tcp,
2542 };
2543
2544 /**
2545  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
2546  *
2547  */
2548 int init_socket_xprt(void)
2549 {
2550 #ifdef RPC_DEBUG
2551         if (!sunrpc_table_header)
2552                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
2553 #endif
2554
2555         xprt_register_transport(&xs_udp_transport);
2556         xprt_register_transport(&xs_tcp_transport);
2557         xprt_register_transport(&xs_bc_tcp_transport);
2558
2559         return 0;
2560 }
2561
2562 /**
2563  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
2564  *
2565  */
2566 void cleanup_socket_xprt(void)
2567 {
2568 #ifdef RPC_DEBUG
2569         if (sunrpc_table_header) {
2570                 unregister_sysctl_table(sunrpc_table_header);
2571                 sunrpc_table_header = NULL;
2572         }
2573 #endif
2574
2575         xprt_unregister_transport(&xs_udp_transport);
2576         xprt_unregister_transport(&xs_tcp_transport);
2577         xprt_unregister_transport(&xs_bc_tcp_transport);
2578 }
2579
2580 static int param_set_uint_minmax(const char *val, struct kernel_param *kp,
2581                 unsigned int min, unsigned int max)
2582 {
2583         unsigned long num;
2584         int ret;
2585
2586         if (!val)
2587                 return -EINVAL;
2588         ret = strict_strtoul(val, 0, &num);
2589         if (ret == -EINVAL || num < min || num > max)
2590                 return -EINVAL;
2591         *((unsigned int *)kp->arg) = num;
2592         return 0;
2593 }
2594
2595 static int param_set_portnr(const char *val, struct kernel_param *kp)
2596 {
2597         return param_set_uint_minmax(val, kp,
2598                         RPC_MIN_RESVPORT,
2599                         RPC_MAX_RESVPORT);
2600 }
2601
2602 static int param_get_portnr(char *buffer, struct kernel_param *kp)
2603 {
2604         return param_get_uint(buffer, kp);
2605 }
2606 #define param_check_portnr(name, p) \
2607         __param_check(name, p, unsigned int);
2608
2609 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
2610 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
2611
2612 static int param_set_slot_table_size(const char *val, struct kernel_param *kp)
2613 {
2614         return param_set_uint_minmax(val, kp,
2615                         RPC_MIN_SLOT_TABLE,
2616                         RPC_MAX_SLOT_TABLE);
2617 }
2618
2619 static int param_get_slot_table_size(char *buffer, struct kernel_param *kp)
2620 {
2621         return param_get_uint(buffer, kp);
2622 }
2623 #define param_check_slot_table_size(name, p) \
2624         __param_check(name, p, unsigned int);
2625
2626 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
2627                    slot_table_size, 0644);
2628 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
2629                    slot_table_size, 0644);
2630