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/string.h>
  23 #include <linux/slab.h>
  24 #include <linux/module.h>
  25 #include <linux/capability.h>
  26 #include <linux/pagemap.h>
  27 #include <linux/errno.h>
  28 #include <linux/socket.h>
  29 #include <linux/in.h>
  30 #include <linux/net.h>
  31 #include <linux/mm.h>
  32 #include <linux/un.h>
  33 #include <linux/udp.h>
  34 #include <linux/tcp.h>
  35 #include <linux/sunrpc/clnt.h>
  36 #include <linux/sunrpc/addr.h>
  37 #include <linux/sunrpc/sched.h>
  38 #include <linux/sunrpc/svcsock.h>
  39 #include <linux/sunrpc/xprtsock.h>
  40 #include <linux/file.h>
  41 #ifdef CONFIG_SUNRPC_BACKCHANNEL
  42 #include <linux/sunrpc/bc_xprt.h>
  43 #endif
  44
  45 #include <net/sock.h>
  46 #include <net/checksum.h>
  47 #include <net/udp.h>
  48 #include <net/tcp.h>
  49
  50 #include <trace/events/sunrpc.h>
  51
  52 #include "sunrpc.h"
  53
  54 static void xs_close(struct rpc_xprt *xprt);
  55
  56 /*
  57  * xprtsock tunables
  58  */
  59 static unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
  60 static unsigned int xprt_tcp_slot_table_entries = RPC_MIN_SLOT_TABLE;
  61 static unsigned int xprt_max_tcp_slot_table_entries = RPC_MAX_SLOT_TABLE;
  62
  63 static unsigned int xprt_min_resvport = RPC_DEF_MIN_RESVPORT;
  64 static unsigned int xprt_max_resvport = RPC_DEF_MAX_RESVPORT;
  65
  66 #define XS_TCP_LINGER_TO        (15U * HZ)
  67 static unsigned int xs_tcp_fin_timeout __read_mostly = XS_TCP_LINGER_TO;
  68
  69 /*
  70  * We can register our own files under /proc/sys/sunrpc by
  71  * calling register_sysctl_table() again.  The files in that
  72  * directory become the union of all files registered there.
  73  *
  74  * We simply need to make sure that we don't collide with
  75  * someone else's file names!
  76  */
  77
  78 #ifdef RPC_DEBUG
  79
  80 static unsigned int min_slot_table_size = RPC_MIN_SLOT_TABLE;
  81 static unsigned int max_slot_table_size = RPC_MAX_SLOT_TABLE;
  82 static unsigned int max_tcp_slot_table_limit = RPC_MAX_SLOT_TABLE_LIMIT;
  83 static unsigned int xprt_min_resvport_limit = RPC_MIN_RESVPORT;
  84 static unsigned int xprt_max_resvport_limit = RPC_MAX_RESVPORT;
  85
  86 static struct ctl_table_header *sunrpc_table_header;
  87
  88 /*
  89  * FIXME: changing the UDP slot table size should also resize the UDP
  90  *        socket buffers for existing UDP transports
  91  */
  92 static struct ctl_table xs_tunables_table[] = {
  93         {
  94                 .procname       = "udp_slot_table_entries",
  95                 .data           = &xprt_udp_slot_table_entries,
  96                 .maxlen         = sizeof(unsigned int),
  97                 .mode           = 0644,
  98                 .proc_handler   = proc_dointvec_minmax,
  99                 .extra1         = &min_slot_table_size,
 100                 .extra2         = &max_slot_table_size
 101         },
 102         {
 103                 .procname       = "tcp_slot_table_entries",
 104                 .data           = &xprt_tcp_slot_table_entries,
 105                 .maxlen         = sizeof(unsigned int),
 106                 .mode           = 0644,
 107                 .proc_handler   = proc_dointvec_minmax,
 108                 .extra1         = &min_slot_table_size,
 109                 .extra2         = &max_slot_table_size
 110         },
 111         {
 112                 .procname       = "tcp_max_slot_table_entries",
 113                 .data           = &xprt_max_tcp_slot_table_entries,
 114                 .maxlen         = sizeof(unsigned int),
 115                 .mode           = 0644,
 116                 .proc_handler   = proc_dointvec_minmax,
 117                 .extra1         = &min_slot_table_size,
 118                 .extra2         = &max_tcp_slot_table_limit
 119         },
 120         {
 121                 .procname       = "min_resvport",
 122                 .data           = &xprt_min_resvport,
 123                 .maxlen         = sizeof(unsigned int),
 124                 .mode           = 0644,
 125                 .proc_handler   = proc_dointvec_minmax,
 126                 .extra1         = &xprt_min_resvport_limit,
 127                 .extra2         = &xprt_max_resvport_limit
 128         },
 129         {
 130                 .procname       = "max_resvport",
 131                 .data           = &xprt_max_resvport,
 132                 .maxlen         = sizeof(unsigned int),
 133                 .mode           = 0644,
 134                 .proc_handler   = proc_dointvec_minmax,
 135                 .extra1         = &xprt_min_resvport_limit,
 136                 .extra2         = &xprt_max_resvport_limit
 137         },
 138         {
 139                 .procname       = "tcp_fin_timeout",
 140                 .data           = &xs_tcp_fin_timeout,
 141                 .maxlen         = sizeof(xs_tcp_fin_timeout),
 142                 .mode           = 0644,
 143                 .proc_handler   = proc_dointvec_jiffies,
 144         },
 145         { },
 146 };
 147
 148 static struct ctl_table sunrpc_table[] = {
 149         {
 150                 .procname       = "sunrpc",
 151                 .mode           = 0555,
 152                 .child          = xs_tunables_table
 153         },
 154         { },
 155 };
 156
 157 #endif
 158
 159 /*
 160  * Wait duration for a reply from the RPC portmapper.
 161  */
 162 #define XS_BIND_TO              (60U * HZ)
 163
 164 /*
 165  * Delay if a UDP socket connect error occurs.  This is most likely some
 166  * kind of resource problem on the local host.
 167  */
 168 #define XS_UDP_REEST_TO         (2U * HZ)
 169
 170 /*
 171  * The reestablish timeout allows clients to delay for a bit before attempting
 172  * to reconnect to a server that just dropped our connection.
 173  *
 174  * We implement an exponential backoff when trying to reestablish a TCP
 175  * transport connection with the server.  Some servers like to drop a TCP
 176  * connection when they are overworked, so we start with a short timeout and
 177  * increase over time if the server is down or not responding.
 178  */
 179 #define XS_TCP_INIT_REEST_TO    (3U * HZ)
 180 #define XS_TCP_MAX_REEST_TO     (5U * 60 * HZ)
 181
 182 /*
 183  * TCP idle timeout; client drops the transport socket if it is idle
 184  * for this long.  Note that we also timeout UDP sockets to prevent
 185  * holding port numbers when there is no RPC traffic.
 186  */
 187 #define XS_IDLE_DISC_TO         (5U * 60 * HZ)
 188
 189 #ifdef RPC_DEBUG
 190 # undef  RPC_DEBUG_DATA
 191 # define RPCDBG_FACILITY        RPCDBG_TRANS
 192 #endif
 193
 194 #ifdef RPC_DEBUG_DATA
 195 static void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 196 {
 197         u8 *buf = (u8 *) packet;
 198         int j;
 199
 200         dprintk("RPC:       %s\n", msg);
 201         for (j = 0; j < count && j < 128; j += 4) {
 202                 if (!(j & 31)) {
 203                         if (j)
 204                                 dprintk("\n");
 205                         dprintk("0x%04x ", j);
 206                 }
 207                 dprintk("%02x%02x%02x%02x ",
 208                         buf[j], buf[j+1], buf[j+2], buf[j+3]);
 209         }
 210         dprintk("\n");
 211 }
 212 #else
 213 static inline void xs_pktdump(char *msg, u32 *packet, unsigned int count)
 214 {
 215         /* NOP */
 216 }
 217 #endif
 218
 219 struct sock_xprt {
 220         struct rpc_xprt         xprt;
 221
 222         /*
 223          * Network layer
 224          */
 225         struct socket *         sock;
 226         struct sock *           inet;
 227
 228         /*
 229          * State of TCP reply receive
 230          */
 231         __be32                  tcp_fraghdr,
 232                                 tcp_xid,
 233                                 tcp_calldir;
 234
 235         u32                     tcp_offset,
 236                                 tcp_reclen;
 237
 238         unsigned long           tcp_copied,
 239                                 tcp_flags;
 240
 241         /*
 242          * Connection of transports
 243          */
 244         struct delayed_work     connect_worker;
 245         struct sockaddr_storage srcaddr;
 246         unsigned short          srcport;
 247
 248         /*
 249          * UDP socket buffer size parameters
 250          */
 251         size_t                  rcvsize,
 252                                 sndsize;
 253
 254         /*
 255          * Saved socket callback addresses
 256          */
 257         void                    (*old_data_ready)(struct sock *);
 258         void                    (*old_state_change)(struct sock *);
 259         void                    (*old_write_space)(struct sock *);
 260         void                    (*old_error_report)(struct sock *);
 261 };
 262
 263 /*
 264  * TCP receive state flags
 265  */
 266 #define TCP_RCV_LAST_FRAG       (1UL << 0)
 267 #define TCP_RCV_COPY_FRAGHDR    (1UL << 1)
 268 #define TCP_RCV_COPY_XID        (1UL << 2)
 269 #define TCP_RCV_COPY_DATA       (1UL << 3)
 270 #define TCP_RCV_READ_CALLDIR    (1UL << 4)
 271 #define TCP_RCV_COPY_CALLDIR    (1UL << 5)
 272
 273 /*
 274  * TCP RPC flags
 275  */
 276 #define TCP_RPC_REPLY           (1UL << 6)
 277
 278 static inline struct rpc_xprt *xprt_from_sock(struct sock *sk)
 279 {
 280         return (struct rpc_xprt *) sk->sk_user_data;
 281 }
 282
 283 static inline struct sockaddr *xs_addr(struct rpc_xprt *xprt)
 284 {
 285         return (struct sockaddr *) &xprt->addr;
 286 }
 287
 288 static inline struct sockaddr_un *xs_addr_un(struct rpc_xprt *xprt)
 289 {
 290         return (struct sockaddr_un *) &xprt->addr;
 291 }
 292
 293 static inline struct sockaddr_in *xs_addr_in(struct rpc_xprt *xprt)
 294 {
 295         return (struct sockaddr_in *) &xprt->addr;
 296 }
 297
 298 static inline struct sockaddr_in6 *xs_addr_in6(struct rpc_xprt *xprt)
 299 {
 300         return (struct sockaddr_in6 *) &xprt->addr;
 301 }
 302
 303 static void xs_format_common_peer_addresses(struct rpc_xprt *xprt)
 304 {
 305         struct sockaddr *sap = xs_addr(xprt);
 306         struct sockaddr_in6 *sin6;
 307         struct sockaddr_in *sin;
 308         struct sockaddr_un *sun;
 309         char buf[128];
 310
 311         switch (sap->sa_family) {
 312         case AF_LOCAL:
 313                 sun = xs_addr_un(xprt);
 314                 strlcpy(buf, sun->sun_path, sizeof(buf));
 315                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 316                                                 kstrdup(buf, GFP_KERNEL);
 317                 break;
 318         case AF_INET:
 319                 (void)rpc_ntop(sap, buf, sizeof(buf));
 320                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 321                                                 kstrdup(buf, GFP_KERNEL);
 322                 sin = xs_addr_in(xprt);
 323                 snprintf(buf, sizeof(buf), "%08x", ntohl(sin->sin_addr.s_addr));
 324                 break;
 325         case AF_INET6:
 326                 (void)rpc_ntop(sap, buf, sizeof(buf));
 327                 xprt->address_strings[RPC_DISPLAY_ADDR] =
 328                                                 kstrdup(buf, GFP_KERNEL);
 329                 sin6 = xs_addr_in6(xprt);
 330                 snprintf(buf, sizeof(buf), "%pi6", &sin6->sin6_addr);
 331                 break;
 332         default:
 333                 BUG();
 334         }
 335
 336         xprt->address_strings[RPC_DISPLAY_HEX_ADDR] = kstrdup(buf, GFP_KERNEL);
 337 }
 338
 339 static void xs_format_common_peer_ports(struct rpc_xprt *xprt)
 340 {
 341         struct sockaddr *sap = xs_addr(xprt);
 342         char buf[128];
 343
 344         snprintf(buf, sizeof(buf), "%u", rpc_get_port(sap));
 345         xprt->address_strings[RPC_DISPLAY_PORT] = kstrdup(buf, GFP_KERNEL);
 346
 347         snprintf(buf, sizeof(buf), "%4hx", rpc_get_port(sap));
 348         xprt->address_strings[RPC_DISPLAY_HEX_PORT] = kstrdup(buf, GFP_KERNEL);
 349 }
 350
 351 static void xs_format_peer_addresses(struct rpc_xprt *xprt,
 352                                      const char *protocol,
 353                                      const char *netid)
 354 {
 355         xprt->address_strings[RPC_DISPLAY_PROTO] = protocol;
 356         xprt->address_strings[RPC_DISPLAY_NETID] = netid;
 357         xs_format_common_peer_addresses(xprt);
 358         xs_format_common_peer_ports(xprt);
 359 }
 360
 361 static void xs_update_peer_port(struct rpc_xprt *xprt)
 362 {
 363         kfree(xprt->address_strings[RPC_DISPLAY_HEX_PORT]);
 364         kfree(xprt->address_strings[RPC_DISPLAY_PORT]);
 365
 366         xs_format_common_peer_ports(xprt);
 367 }
 368
 369 static void xs_free_peer_addresses(struct rpc_xprt *xprt)
 370 {
 371         unsigned int i;
 372
 373         for (i = 0; i < RPC_DISPLAY_MAX; i++)
 374                 switch (i) {
 375                 case RPC_DISPLAY_PROTO:
 376                 case RPC_DISPLAY_NETID:
 377                         continue;
 378                 default:
 379                         kfree(xprt->address_strings[i]);
 380                 }
 381 }
 382
 383 #define XS_SENDMSG_FLAGS        (MSG_DONTWAIT | MSG_NOSIGNAL)
 384
 385 static int xs_send_kvec(struct socket *sock, struct sockaddr *addr, int addrlen, struct kvec *vec, unsigned int base, int more)
 386 {
 387         struct msghdr msg = {
 388                 .msg_name       = addr,
 389                 .msg_namelen    = addrlen,
 390                 .msg_flags      = XS_SENDMSG_FLAGS | (more ? MSG_MORE : 0),
 391         };
 392         struct kvec iov = {
 393                 .iov_base       = vec->iov_base + base,
 394                 .iov_len        = vec->iov_len - base,
 395         };
 396
 397         if (iov.iov_len != 0)
 398                 return kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);
 399         return kernel_sendmsg(sock, &msg, NULL, 0, 0);
 400 }
 401
 402 static int xs_send_pagedata(struct socket *sock, struct xdr_buf *xdr, unsigned int base, int more, bool zerocopy)
 403 {
 404         ssize_t (*do_sendpage)(struct socket *sock, struct page *page,
 405                         int offset, size_t size, int flags);
 406         struct page **ppage;
 407         unsigned int remainder;
 408         int err, sent = 0;
 409
 410         remainder = xdr->page_len - base;
 411         base += xdr->page_base;
 412         ppage = xdr->pages + (base >> PAGE_SHIFT);
 413         base &= ~PAGE_MASK;
 414         do_sendpage = sock->ops->sendpage;
 415         if (!zerocopy)
 416                 do_sendpage = sock_no_sendpage;
 417         for(;;) {
 418                 unsigned int len = min_t(unsigned int, PAGE_SIZE - base, remainder);
 419                 int flags = XS_SENDMSG_FLAGS;
 420
 421                 remainder -= len;
 422                 if (remainder != 0 || more)
 423                         flags |= MSG_MORE;
 424                 err = do_sendpage(sock, *ppage, base, len, flags);
 425                 if (remainder == 0 || err != len)
 426                         break;
 427                 sent += err;
 428                 ppage++;
 429                 base = 0;
 430         }
 431         if (sent == 0)
 432                 return err;
 433         if (err > 0)
 434                 sent += err;
 435         return sent;
 436 }
 437
 438 /**
 439  * xs_sendpages - write pages directly to a socket
 440  * @sock: socket to send on
 441  * @addr: UDP only -- address of destination
 442  * @addrlen: UDP only -- length of destination address
 443  * @xdr: buffer containing this request
 444  * @base: starting position in the buffer
 445  * @zerocopy: true if it is safe to use sendpage()
 446  *
 447  */
 448 static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base, bool zerocopy)
 449 {
 450         unsigned int remainder = xdr->len - base;
 451         int err, sent = 0;
 452
 453         if (unlikely(!sock))
 454                 return -ENOTSOCK;
 455
 456         clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
 457         if (base != 0) {
 458                 addr = NULL;
 459                 addrlen = 0;
 460         }
 461
 462         if (base < xdr->head[0].iov_len || addr != NULL) {
 463                 unsigned int len = xdr->head[0].iov_len - base;
 464                 remainder -= len;
 465                 err = xs_send_kvec(sock, addr, addrlen, &xdr->head[0], base, remainder != 0);
 466                 if (remainder == 0 || err != len)
 467                         goto out;
 468                 sent += err;
 469                 base = 0;
 470         } else
 471                 base -= xdr->head[0].iov_len;
 472
 473         if (base < xdr->page_len) {
 474                 unsigned int len = xdr->page_len - base;
 475                 remainder -= len;
 476                 err = xs_send_pagedata(sock, xdr, base, remainder != 0, zerocopy);
 477                 if (remainder == 0 || err != len)
 478                         goto out;
 479                 sent += err;
 480                 base = 0;
 481         } else
 482                 base -= xdr->page_len;
 483
 484         if (base >= xdr->tail[0].iov_len)
 485                 return sent;
 486         err = xs_send_kvec(sock, NULL, 0, &xdr->tail[0], base, 0);
 487 out:
 488         if (sent == 0)
 489                 return err;
 490         if (err > 0)
 491                 sent += err;
 492         return sent;
 493 }
 494
 495 static void xs_nospace_callback(struct rpc_task *task)
 496 {
 497         struct sock_xprt *transport = container_of(task->tk_rqstp->rq_xprt, struct sock_xprt, xprt);
 498
 499         transport->inet->sk_write_pending--;
 500         clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 501 }
 502
 503 /**
 504  * xs_nospace - place task on wait queue if transmit was incomplete
 505  * @task: task to put to sleep
 506  *
 507  */
 508 static int xs_nospace(struct rpc_task *task)
 509 {
 510         struct rpc_rqst *req = task->tk_rqstp;
 511         struct rpc_xprt *xprt = req->rq_xprt;
 512         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 513         struct sock *sk = transport->inet;
 514         int ret = -EAGAIN;
 515
 516         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
 517                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
 518                         req->rq_slen);
 519
 520         /* Protect against races with write_space */
 521         spin_lock_bh(&xprt->transport_lock);
 522
 523         /* Don't race with disconnect */
 524         if (xprt_connected(xprt)) {
 525                 if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
 526                         /*
 527                          * Notify TCP that we're limited by the application
 528                          * window size
 529                          */
 530                         set_bit(SOCK_NOSPACE, &transport->sock->flags);
 531                         sk->sk_write_pending++;
 532                         /* ...and wait for more buffer space */
 533                         xprt_wait_for_buffer_space(task, xs_nospace_callback);
 534                 }
 535         } else {
 536                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 537                 ret = -ENOTCONN;
 538         }
 539
 540         spin_unlock_bh(&xprt->transport_lock);
 541
 542         /* Race breaker in case memory is freed before above code is called */
 543         sk->sk_write_space(sk);
 544         return ret;
 545 }
 546
 547 /*
 548  * Construct a stream transport record marker in @buf.
 549  */
 550 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
 551 {
 552         u32 reclen = buf->len - sizeof(rpc_fraghdr);
 553         rpc_fraghdr *base = buf->head[0].iov_base;
 554         *base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
 555 }
 556
 557 /**
 558  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
 559  * @task: RPC task that manages the state of an RPC request
 560  *
 561  * Return values:
 562  *        0:    The request has been sent
 563  *   EAGAIN:    The socket was blocked, please call again later to
 564  *              complete the request
 565  * ENOTCONN:    Caller needs to invoke connect logic then call again
 566  *    other:    Some other error occured, the request was not sent
 567  */
 568 static int xs_local_send_request(struct rpc_task *task)
 569 {
 570         struct rpc_rqst *req = task->tk_rqstp;
 571         struct rpc_xprt *xprt = req->rq_xprt;
 572         struct sock_xprt *transport =
 573                                 container_of(xprt, struct sock_xprt, xprt);
 574         struct xdr_buf *xdr = &req->rq_snd_buf;
 575         int status;
 576
 577         xs_encode_stream_record_marker(&req->rq_snd_buf);
 578
 579         xs_pktdump("packet data:",
 580                         req->rq_svec->iov_base, req->rq_svec->iov_len);
 581
 582         status = xs_sendpages(transport->sock, NULL, 0,
 583                                                 xdr, req->rq_bytes_sent, true);
 584         dprintk("RPC:       %s(%u) = %d\n",
 585                         __func__, xdr->len - req->rq_bytes_sent, status);
 586         if (likely(status >= 0)) {
 587                 req->rq_bytes_sent += status;
 588                 req->rq_xmit_bytes_sent += status;
 589                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 590                         req->rq_bytes_sent = 0;
 591                         return 0;
 592                 }
 593                 status = -EAGAIN;
 594         }
 595
 596         switch (status) {
 597         case -ENOBUFS:
 598         case -EAGAIN:
 599                 status = xs_nospace(task);
 600                 break;
 601         default:
 602                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 603                         -status);
 604         case -EPIPE:
 605                 xs_close(xprt);
 606                 status = -ENOTCONN;
 607         }
 608
 609         return status;
 610 }
 611
 612 /**
 613  * xs_udp_send_request - write an RPC request to a UDP socket
 614  * @task: address of RPC task that manages the state of an RPC request
 615  *
 616  * Return values:
 617  *        0:    The request has been sent
 618  *   EAGAIN:    The socket was blocked, please call again later to
 619  *              complete the request
 620  * ENOTCONN:    Caller needs to invoke connect logic then call again
 621  *    other:    Some other error occurred, the request was not sent
 622  */
 623 static int xs_udp_send_request(struct rpc_task *task)
 624 {
 625         struct rpc_rqst *req = task->tk_rqstp;
 626         struct rpc_xprt *xprt = req->rq_xprt;
 627         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 628         struct xdr_buf *xdr = &req->rq_snd_buf;
 629         int status;
 630
 631         xs_pktdump("packet data:",
 632                                 req->rq_svec->iov_base,
 633                                 req->rq_svec->iov_len);
 634
 635         if (!xprt_bound(xprt))
 636                 return -ENOTCONN;
 637         status = xs_sendpages(transport->sock,
 638                               xs_addr(xprt),
 639                               xprt->addrlen, xdr,
 640                               req->rq_bytes_sent, true);
 641
 642         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
 643                         xdr->len - req->rq_bytes_sent, status);
 644
 645         if (status >= 0) {
 646                 req->rq_xmit_bytes_sent += status;
 647                 if (status >= req->rq_slen)
 648                         return 0;
 649                 /* Still some bytes left; set up for a retry later. */
 650                 status = -EAGAIN;
 651         }
 652
 653         switch (status) {
 654         case -ENOTSOCK:
 655                 status = -ENOTCONN;
 656                 /* Should we call xs_close() here? */
 657                 break;
 658         case -EAGAIN:
 659                 status = xs_nospace(task);
 660                 break;
 661         default:
 662                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 663                         -status);
 664         case -ENETUNREACH:
 665         case -ENOBUFS:
 666         case -EPIPE:
 667         case -ECONNREFUSED:
 668                 /* When the server has died, an ICMP port unreachable message
 669                  * prompts ECONNREFUSED. */
 670                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 671         }
 672
 673         return status;
 674 }
 675
 676 /**
 677  * xs_tcp_shutdown - gracefully shut down a TCP socket
 678  * @xprt: transport
 679  *
 680  * Initiates a graceful shutdown of the TCP socket by calling the
 681  * equivalent of shutdown(SHUT_WR);
 682  */
 683 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
 684 {
 685         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 686         struct socket *sock = transport->sock;
 687
 688         if (sock != NULL) {
 689                 kernel_sock_shutdown(sock, SHUT_WR);
 690                 trace_rpc_socket_shutdown(xprt, sock);
 691         }
 692 }
 693
 694 /**
 695  * xs_tcp_send_request - write an RPC request to a TCP socket
 696  * @task: address of RPC task that manages the state of an RPC request
 697  *
 698  * Return values:
 699  *        0:    The request has been sent
 700  *   EAGAIN:    The socket was blocked, please call again later to
 701  *              complete the request
 702  * ENOTCONN:    Caller needs to invoke connect logic then call again
 703  *    other:    Some other error occurred, the request was not sent
 704  *
 705  * XXX: In the case of soft timeouts, should we eventually give up
 706  *      if sendmsg is not able to make progress?
 707  */
 708 static int xs_tcp_send_request(struct rpc_task *task)
 709 {
 710         struct rpc_rqst *req = task->tk_rqstp;
 711         struct rpc_xprt *xprt = req->rq_xprt;
 712         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 713         struct xdr_buf *xdr = &req->rq_snd_buf;
 714         bool zerocopy = true;
 715         int status;
 716
 717         xs_encode_stream_record_marker(&req->rq_snd_buf);
 718
 719         xs_pktdump("packet data:",
 720                                 req->rq_svec->iov_base,
 721                                 req->rq_svec->iov_len);
 722         /* Don't use zero copy if this is a resend. If the RPC call
 723          * completes while the socket holds a reference to the pages,
 724          * then we may end up resending corrupted data.
 725          */
 726         if (task->tk_flags & RPC_TASK_SENT)
 727                 zerocopy = false;
 728
 729         /* Continue transmitting the packet/record. We must be careful
 730          * to cope with writespace callbacks arriving _after_ we have
 731          * called sendmsg(). */
 732         while (1) {
 733                 status = xs_sendpages(transport->sock,
 734                                         NULL, 0, xdr, req->rq_bytes_sent,
 735                                         zerocopy);
 736
 737                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 738                                 xdr->len - req->rq_bytes_sent, status);
 739
 740                 if (unlikely(status < 0))
 741                         break;
 742
 743                 /* If we've sent the entire packet, immediately
 744                  * reset the count of bytes sent. */
 745                 req->rq_bytes_sent += status;
 746                 req->rq_xmit_bytes_sent += status;
 747                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 748                         req->rq_bytes_sent = 0;
 749                         return 0;
 750                 }
 751
 752                 if (status != 0)
 753                         continue;
 754                 status = -EAGAIN;
 755                 break;
 756         }
 757
 758         switch (status) {
 759         case -ENOTSOCK:
 760                 status = -ENOTCONN;
 761                 /* Should we call xs_close() here? */
 762                 break;
 763         case -ENOBUFS:
 764         case -EAGAIN:
 765                 status = xs_nospace(task);
 766                 break;
 767         default:
 768                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 769                         -status);
 770         case -ECONNRESET:
 771                 xs_tcp_shutdown(xprt);
 772         case -ECONNREFUSED:
 773         case -ENOTCONN:
 774         case -EPIPE:
 775                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 776         }
 777
 778         return status;
 779 }
 780
 781 /**
 782  * xs_tcp_release_xprt - clean up after a tcp transmission
 783  * @xprt: transport
 784  * @task: rpc task
 785  *
 786  * This cleans up if an error causes us to abort the transmission of a request.
 787  * In this case, the socket may need to be reset in order to avoid confusing
 788  * the server.
 789  */
 790 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 791 {
 792         struct rpc_rqst *req;
 793
 794         if (task != xprt->snd_task)
 795                 return;
 796         if (task == NULL)
 797                 goto out_release;
 798         req = task->tk_rqstp;
 799         if (req == NULL)
 800                 goto out_release;
 801         if (req->rq_bytes_sent == 0)
 802                 goto out_release;
 803         if (req->rq_bytes_sent == req->rq_snd_buf.len)
 804                 goto out_release;
 805         set_bit(XPRT_CLOSE_WAIT, &xprt->state);
 806 out_release:
 807         xprt_release_xprt(xprt, task);
 808 }
 809
 810 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 811 {
 812         transport->old_data_ready = sk->sk_data_ready;
 813         transport->old_state_change = sk->sk_state_change;
 814         transport->old_write_space = sk->sk_write_space;
 815         transport->old_error_report = sk->sk_error_report;
 816 }
 817
 818 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 819 {
 820         sk->sk_data_ready = transport->old_data_ready;
 821         sk->sk_state_change = transport->old_state_change;
 822         sk->sk_write_space = transport->old_write_space;
 823         sk->sk_error_report = transport->old_error_report;
 824 }
 825
 826 /**
 827  * xs_error_report - callback to handle TCP socket state errors
 828  * @sk: socket
 829  *
 830  * Note: we don't call sock_error() since there may be a rpc_task
 831  * using the socket, and so we don't want to clear sk->sk_err.
 832  */
 833 static void xs_error_report(struct sock *sk)
 834 {
 835         struct rpc_xprt *xprt;
 836         int err;
 837
 838         read_lock_bh(&sk->sk_callback_lock);
 839         if (!(xprt = xprt_from_sock(sk)))
 840                 goto out;
 841
 842         err = -sk->sk_err;
 843         if (err == 0)
 844                 goto out;
 845         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
 846                         xprt, -err);
 847         trace_rpc_socket_error(xprt, sk->sk_socket, err);
 848         xprt_wake_pending_tasks(xprt, err);
 849  out:
 850         read_unlock_bh(&sk->sk_callback_lock);
 851 }
 852
 853 static void xs_reset_transport(struct sock_xprt *transport)
 854 {
 855         struct socket *sock = transport->sock;
 856         struct sock *sk = transport->inet;
 857
 858         if (sk == NULL)
 859                 return;
 860
 861         transport->srcport = 0;
 862
 863         write_lock_bh(&sk->sk_callback_lock);
 864         transport->inet = NULL;
 865         transport->sock = NULL;
 866
 867         sk->sk_user_data = NULL;
 868
 869         xs_restore_old_callbacks(transport, sk);
 870         write_unlock_bh(&sk->sk_callback_lock);
 871
 872         trace_rpc_socket_close(&transport->xprt, sock);
 873         sock_release(sock);
 874 }
 875
 876 /**
 877  * xs_close - close a socket
 878  * @xprt: transport
 879  *
 880  * This is used when all requests are complete; ie, no DRC state remains
 881  * on the server we want to save.
 882  *
 883  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
 884  * xs_reset_transport() zeroing the socket from underneath a writer.
 885  */
 886 static void xs_close(struct rpc_xprt *xprt)
 887 {
 888         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 889
 890         dprintk("RPC:       xs_close xprt %p\n", xprt);
 891
 892         cancel_delayed_work_sync(&transport->connect_worker);
 893
 894         xs_reset_transport(transport);
 895         xprt->reestablish_timeout = 0;
 896
 897         smp_mb__before_atomic();
 898         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
 899         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
 900         clear_bit(XPRT_CLOSING, &xprt->state);
 901         smp_mb__after_atomic();
 902         xprt_disconnect_done(xprt);
 903 }
 904
 905 static void xs_tcp_close(struct rpc_xprt *xprt)
 906 {
 907         if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
 908                 xs_close(xprt);
 909         else
 910                 xs_tcp_shutdown(xprt);
 911 }
 912
 913 static void xs_xprt_free(struct rpc_xprt *xprt)
 914 {
 915         xs_free_peer_addresses(xprt);
 916         xprt_free(xprt);
 917 }
 918
 919 /**
 920  * xs_destroy - prepare to shutdown a transport
 921  * @xprt: doomed transport
 922  *
 923  */
 924 static void xs_destroy(struct rpc_xprt *xprt)
 925 {
 926         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
 927
 928         xs_close(xprt);
 929         xs_xprt_free(xprt);
 930         module_put(THIS_MODULE);
 931 }
 932
 933 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
 934 {
 935         struct xdr_skb_reader desc = {
 936                 .skb            = skb,
 937                 .offset         = sizeof(rpc_fraghdr),
 938                 .count          = skb->len - sizeof(rpc_fraghdr),
 939         };
 940
 941         if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
 942                 return -1;
 943         if (desc.count)
 944                 return -1;
 945         return 0;
 946 }
 947
 948 /**
 949  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
 950  * @sk: socket with data to read
 951  * @len: how much data to read
 952  *
 953  * Currently this assumes we can read the whole reply in a single gulp.
 954  */
 955 static void xs_local_data_ready(struct sock *sk)
 956 {
 957         struct rpc_task *task;
 958         struct rpc_xprt *xprt;
 959         struct rpc_rqst *rovr;
 960         struct sk_buff *skb;
 961         int err, repsize, copied;
 962         u32 _xid;
 963         __be32 *xp;
 964
 965         read_lock_bh(&sk->sk_callback_lock);
 966         dprintk("RPC:       %s...\n", __func__);
 967         xprt = xprt_from_sock(sk);
 968         if (xprt == NULL)
 969                 goto out;
 970
 971         skb = skb_recv_datagram(sk, 0, 1, &err);
 972         if (skb == NULL)
 973                 goto out;
 974
 975         repsize = skb->len - sizeof(rpc_fraghdr);
 976         if (repsize < 4) {
 977                 dprintk("RPC:       impossible RPC reply size %d\n", repsize);
 978                 goto dropit;
 979         }
 980
 981         /* Copy the XID from the skb... */
 982         xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
 983         if (xp == NULL)
 984                 goto dropit;
 985
 986         /* Look up and lock the request corresponding to the given XID */
 987         spin_lock(&xprt->transport_lock);
 988         rovr = xprt_lookup_rqst(xprt, *xp);
 989         if (!rovr)
 990                 goto out_unlock;
 991         task = rovr->rq_task;
 992
 993         copied = rovr->rq_private_buf.buflen;
 994         if (copied > repsize)
 995                 copied = repsize;
 996
 997         if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
 998                 dprintk("RPC:       sk_buff copy failed\n");
 999                 goto out_unlock;
1000         }
1001
1002         xprt_complete_rqst(task, copied);
1003
1004  out_unlock:
1005         spin_unlock(&xprt->transport_lock);
1006  dropit:
1007         skb_free_datagram(sk, skb);
1008  out:
1009         read_unlock_bh(&sk->sk_callback_lock);
1010 }
1011
1012 /**
1013  * xs_udp_data_ready - "data ready" callback for UDP sockets
1014  * @sk: socket with data to read
1015  * @len: how much data to read
1016  *
1017  */
1018 static void xs_udp_data_ready(struct sock *sk)
1019 {
1020         struct rpc_task *task;
1021         struct rpc_xprt *xprt;
1022         struct rpc_rqst *rovr;
1023         struct sk_buff *skb;
1024         int err, repsize, copied;
1025         u32 _xid;
1026         __be32 *xp;
1027
1028         read_lock_bh(&sk->sk_callback_lock);
1029         dprintk("RPC:       xs_udp_data_ready...\n");
1030         if (!(xprt = xprt_from_sock(sk)))
1031                 goto out;
1032
1033         if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
1034                 goto out;
1035
1036         repsize = skb->len - sizeof(struct udphdr);
1037         if (repsize < 4) {
1038                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1039                 goto dropit;
1040         }
1041
1042         /* Copy the XID from the skb... */
1043         xp = skb_header_pointer(skb, sizeof(struct udphdr),
1044                                 sizeof(_xid), &_xid);
1045         if (xp == NULL)
1046                 goto dropit;
1047
1048         /* Look up and lock the request corresponding to the given XID */
1049         spin_lock(&xprt->transport_lock);
1050         rovr = xprt_lookup_rqst(xprt, *xp);
1051         if (!rovr)
1052                 goto out_unlock;
1053         task = rovr->rq_task;
1054
1055         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1056                 copied = repsize;
1057
1058         /* Suck it into the iovec, verify checksum if not done by hw. */
1059         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1060                 UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1061                 goto out_unlock;
1062         }
1063
1064         UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1065
1066         xprt_adjust_cwnd(xprt, task, copied);
1067         xprt_complete_rqst(task, copied);
1068
1069  out_unlock:
1070         spin_unlock(&xprt->transport_lock);
1071  dropit:
1072         skb_free_datagram(sk, skb);
1073  out:
1074         read_unlock_bh(&sk->sk_callback_lock);
1075 }
1076
1077 /*
1078  * Helper function to force a TCP close if the server is sending
1079  * junk and/or it has put us in CLOSE_WAIT
1080  */
1081 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1082 {
1083         set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1084         xprt_force_disconnect(xprt);
1085 }
1086
1087 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1088 {
1089         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1090         size_t len, used;
1091         char *p;
1092
1093         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1094         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1095         used = xdr_skb_read_bits(desc, p, len);
1096         transport->tcp_offset += used;
1097         if (used != len)
1098                 return;
1099
1100         transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1101         if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1102                 transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1103         else
1104                 transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1105         transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1106
1107         transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1108         transport->tcp_offset = 0;
1109
1110         /* Sanity check of the record length */
1111         if (unlikely(transport->tcp_reclen < 8)) {
1112                 dprintk("RPC:       invalid TCP record fragment length\n");
1113                 xs_tcp_force_close(xprt);
1114                 return;
1115         }
1116         dprintk("RPC:       reading TCP record fragment of length %d\n",
1117                         transport->tcp_reclen);
1118 }
1119
1120 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1121 {
1122         if (transport->tcp_offset == transport->tcp_reclen) {
1123                 transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1124                 transport->tcp_offset = 0;
1125                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1126                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1127                         transport->tcp_flags |= TCP_RCV_COPY_XID;
1128                         transport->tcp_copied = 0;
1129                 }
1130         }
1131 }
1132
1133 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1134 {
1135         size_t len, used;
1136         char *p;
1137
1138         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1139         dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1140         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1141         used = xdr_skb_read_bits(desc, p, len);
1142         transport->tcp_offset += used;
1143         if (used != len)
1144                 return;
1145         transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1146         transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1147         transport->tcp_copied = 4;
1148         dprintk("RPC:       reading %s XID %08x\n",
1149                         (transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1150                                                               : "request with",
1151                         ntohl(transport->tcp_xid));
1152         xs_tcp_check_fraghdr(transport);
1153 }
1154
1155 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1156                                        struct xdr_skb_reader *desc)
1157 {
1158         size_t len, used;
1159         u32 offset;
1160         char *p;
1161
1162         /*
1163          * We want transport->tcp_offset to be 8 at the end of this routine
1164          * (4 bytes for the xid and 4 bytes for the call/reply flag).
1165          * When this function is called for the first time,
1166          * transport->tcp_offset is 4 (after having already read the xid).
1167          */
1168         offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1169         len = sizeof(transport->tcp_calldir) - offset;
1170         dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1171         p = ((char *) &transport->tcp_calldir) + offset;
1172         used = xdr_skb_read_bits(desc, p, len);
1173         transport->tcp_offset += used;
1174         if (used != len)
1175                 return;
1176         transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1177         /*
1178          * We don't yet have the XDR buffer, so we will write the calldir
1179          * out after we get the buffer from the 'struct rpc_rqst'
1180          */
1181         switch (ntohl(transport->tcp_calldir)) {
1182         case RPC_REPLY:
1183                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1184                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1185                 transport->tcp_flags |= TCP_RPC_REPLY;
1186                 break;
1187         case RPC_CALL:
1188                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1189                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1190                 transport->tcp_flags &= ~TCP_RPC_REPLY;
1191                 break;
1192         default:
1193                 dprintk("RPC:       invalid request message type\n");
1194                 xs_tcp_force_close(&transport->xprt);
1195         }
1196         xs_tcp_check_fraghdr(transport);
1197 }
1198
1199 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1200                                      struct xdr_skb_reader *desc,
1201                                      struct rpc_rqst *req)
1202 {
1203         struct sock_xprt *transport =
1204                                 container_of(xprt, struct sock_xprt, xprt);
1205         struct xdr_buf *rcvbuf;
1206         size_t len;
1207         ssize_t r;
1208
1209         rcvbuf = &req->rq_private_buf;
1210
1211         if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1212                 /*
1213                  * Save the RPC direction in the XDR buffer
1214                  */
1215                 memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1216                         &transport->tcp_calldir,
1217                         sizeof(transport->tcp_calldir));
1218                 transport->tcp_copied += sizeof(transport->tcp_calldir);
1219                 transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1220         }
1221
1222         len = desc->count;
1223         if (len > transport->tcp_reclen - transport->tcp_offset) {
1224                 struct xdr_skb_reader my_desc;
1225
1226                 len = transport->tcp_reclen - transport->tcp_offset;
1227                 memcpy(&my_desc, desc, sizeof(my_desc));
1228                 my_desc.count = len;
1229                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1230                                           &my_desc, xdr_skb_read_bits);
1231                 desc->count -= r;
1232                 desc->offset += r;
1233         } else
1234                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1235                                           desc, xdr_skb_read_bits);
1236
1237         if (r > 0) {
1238                 transport->tcp_copied += r;
1239                 transport->tcp_offset += r;
1240         }
1241         if (r != len) {
1242                 /* Error when copying to the receive buffer,
1243                  * usually because we weren't able to allocate
1244                  * additional buffer pages. All we can do now
1245                  * is turn off TCP_RCV_COPY_DATA, so the request
1246                  * will not receive any additional updates,
1247                  * and time out.
1248                  * Any remaining data from this record will
1249                  * be discarded.
1250                  */
1251                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1252                 dprintk("RPC:       XID %08x truncated request\n",
1253                                 ntohl(transport->tcp_xid));
1254                 dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1255                                 "tcp_offset = %u, tcp_reclen = %u\n",
1256                                 xprt, transport->tcp_copied,
1257                                 transport->tcp_offset, transport->tcp_reclen);
1258                 return;
1259         }
1260
1261         dprintk("RPC:       XID %08x read %Zd bytes\n",
1262                         ntohl(transport->tcp_xid), r);
1263         dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1264                         "tcp_reclen = %u\n", xprt, transport->tcp_copied,
1265                         transport->tcp_offset, transport->tcp_reclen);
1266
1267         if (transport->tcp_copied == req->rq_private_buf.buflen)
1268                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1269         else if (transport->tcp_offset == transport->tcp_reclen) {
1270                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1271                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1272         }
1273 }
1274
1275 /*
1276  * Finds the request corresponding to the RPC xid and invokes the common
1277  * tcp read code to read the data.
1278  */
1279 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1280                                     struct xdr_skb_reader *desc)
1281 {
1282         struct sock_xprt *transport =
1283                                 container_of(xprt, struct sock_xprt, xprt);
1284         struct rpc_rqst *req;
1285
1286         dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1287
1288         /* Find and lock the request corresponding to this xid */
1289         spin_lock(&xprt->transport_lock);
1290         req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1291         if (!req) {
1292                 dprintk("RPC:       XID %08x request not found!\n",
1293                                 ntohl(transport->tcp_xid));
1294                 spin_unlock(&xprt->transport_lock);
1295                 return -1;
1296         }
1297
1298         xs_tcp_read_common(xprt, desc, req);
1299
1300         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1301                 xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1302
1303         spin_unlock(&xprt->transport_lock);
1304         return 0;
1305 }
1306
1307 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1308 /*
1309  * Obtains an rpc_rqst previously allocated and invokes the common
1310  * tcp read code to read the data.  The result is placed in the callback
1311  * queue.
1312  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1313  * connection and return -1.
1314  */
1315 static int xs_tcp_read_callback(struct rpc_xprt *xprt,
1316                                        struct xdr_skb_reader *desc)
1317 {
1318         struct sock_xprt *transport =
1319                                 container_of(xprt, struct sock_xprt, xprt);
1320         struct rpc_rqst *req;
1321
1322         /* Look up and lock the request corresponding to the given XID */
1323         spin_lock(&xprt->transport_lock);
1324         req = xprt_lookup_bc_request(xprt, transport->tcp_xid);
1325         if (req == NULL) {
1326                 spin_unlock(&xprt->transport_lock);
1327                 printk(KERN_WARNING "Callback slot table overflowed\n");
1328                 xprt_force_disconnect(xprt);
1329                 return -1;
1330         }
1331
1332         dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1333         xs_tcp_read_common(xprt, desc, req);
1334
1335         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1336                 xprt_complete_bc_request(req, transport->tcp_copied);
1337         spin_unlock(&xprt->transport_lock);
1338
1339         return 0;
1340 }
1341
1342 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1343                                         struct xdr_skb_reader *desc)
1344 {
1345         struct sock_xprt *transport =
1346                                 container_of(xprt, struct sock_xprt, xprt);
1347
1348         return (transport->tcp_flags & TCP_RPC_REPLY) ?
1349                 xs_tcp_read_reply(xprt, desc) :
1350                 xs_tcp_read_callback(xprt, desc);
1351 }
1352 #else
1353 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1354                                         struct xdr_skb_reader *desc)
1355 {
1356         return xs_tcp_read_reply(xprt, desc);
1357 }
1358 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1359
1360 /*
1361  * Read data off the transport.  This can be either an RPC_CALL or an
1362  * RPC_REPLY.  Relay the processing to helper functions.
1363  */
1364 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1365                                     struct xdr_skb_reader *desc)
1366 {
1367         struct sock_xprt *transport =
1368                                 container_of(xprt, struct sock_xprt, xprt);
1369
1370         if (_xs_tcp_read_data(xprt, desc) == 0)
1371                 xs_tcp_check_fraghdr(transport);
1372         else {
1373                 /*
1374                  * The transport_lock protects the request handling.
1375                  * There's no need to hold it to update the tcp_flags.
1376                  */
1377                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1378         }
1379 }
1380
1381 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1382 {
1383         size_t len;
1384
1385         len = transport->tcp_reclen - transport->tcp_offset;
1386         if (len > desc->count)
1387                 len = desc->count;
1388         desc->count -= len;
1389         desc->offset += len;
1390         transport->tcp_offset += len;
1391         dprintk("RPC:       discarded %Zu bytes\n", len);
1392         xs_tcp_check_fraghdr(transport);
1393 }
1394
1395 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1396 {
1397         struct rpc_xprt *xprt = rd_desc->arg.data;
1398         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1399         struct xdr_skb_reader desc = {
1400                 .skb    = skb,
1401                 .offset = offset,
1402                 .count  = len,
1403         };
1404
1405         dprintk("RPC:       xs_tcp_data_recv started\n");
1406         do {
1407                 /* Read in a new fragment marker if necessary */
1408                 /* Can we ever really expect to get completely empty fragments? */
1409                 if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1410                         xs_tcp_read_fraghdr(xprt, &desc);
1411                         continue;
1412                 }
1413                 /* Read in the xid if necessary */
1414                 if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1415                         xs_tcp_read_xid(transport, &desc);
1416                         continue;
1417                 }
1418                 /* Read in the call/reply flag */
1419                 if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1420                         xs_tcp_read_calldir(transport, &desc);
1421                         continue;
1422                 }
1423                 /* Read in the request data */
1424                 if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1425                         xs_tcp_read_data(xprt, &desc);
1426                         continue;
1427                 }
1428                 /* Skip over any trailing bytes on short reads */
1429                 xs_tcp_read_discard(transport, &desc);
1430         } while (desc.count);
1431         dprintk("RPC:       xs_tcp_data_recv done\n");
1432         return len - desc.count;
1433 }
1434
1435 /**
1436  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1437  * @sk: socket with data to read
1438  * @bytes: how much data to read
1439  *
1440  */
1441 static void xs_tcp_data_ready(struct sock *sk)
1442 {
1443         struct rpc_xprt *xprt;
1444         read_descriptor_t rd_desc;
1445         int read;
1446
1447         dprintk("RPC:       xs_tcp_data_ready...\n");
1448
1449         read_lock_bh(&sk->sk_callback_lock);
1450         if (!(xprt = xprt_from_sock(sk)))
1451                 goto out;
1452         /* Any data means we had a useful conversation, so
1453          * the we don't need to delay the next reconnect
1454          */
1455         if (xprt->reestablish_timeout)
1456                 xprt->reestablish_timeout = 0;
1457
1458         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1459         rd_desc.arg.data = xprt;
1460         do {
1461                 rd_desc.count = 65536;
1462                 read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1463         } while (read > 0);
1464 out:
1465         read_unlock_bh(&sk->sk_callback_lock);
1466 }
1467
1468 /*
1469  * Do the equivalent of linger/linger2 handling for dealing with
1470  * broken servers that don't close the socket in a timely
1471  * fashion
1472  */
1473 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1474                 unsigned long timeout)
1475 {
1476         struct sock_xprt *transport;
1477
1478         if (xprt_test_and_set_connecting(xprt))
1479                 return;
1480         set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1481         transport = container_of(xprt, struct sock_xprt, xprt);
1482         queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1483                            timeout);
1484 }
1485
1486 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1487 {
1488         struct sock_xprt *transport;
1489
1490         transport = container_of(xprt, struct sock_xprt, xprt);
1491
1492         if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1493             !cancel_delayed_work(&transport->connect_worker))
1494                 return;
1495         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1496         xprt_clear_connecting(xprt);
1497 }
1498
1499 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1500 {
1501         smp_mb__before_atomic();
1502         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1503         clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1504         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1505         clear_bit(XPRT_CLOSING, &xprt->state);
1506         smp_mb__after_atomic();
1507 }
1508
1509 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1510 {
1511         xs_sock_reset_connection_flags(xprt);
1512         /* Mark transport as closed and wake up all pending tasks */
1513         xprt_disconnect_done(xprt);
1514 }
1515
1516 /**
1517  * xs_tcp_state_change - callback to handle TCP socket state changes
1518  * @sk: socket whose state has changed
1519  *
1520  */
1521 static void xs_tcp_state_change(struct sock *sk)
1522 {
1523         struct rpc_xprt *xprt;
1524
1525         read_lock_bh(&sk->sk_callback_lock);
1526         if (!(xprt = xprt_from_sock(sk)))
1527                 goto out;
1528         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1529         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1530                         sk->sk_state, xprt_connected(xprt),
1531                         sock_flag(sk, SOCK_DEAD),
1532                         sock_flag(sk, SOCK_ZAPPED),
1533                         sk->sk_shutdown);
1534
1535         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1536         switch (sk->sk_state) {
1537         case TCP_ESTABLISHED:
1538                 spin_lock(&xprt->transport_lock);
1539                 if (!xprt_test_and_set_connected(xprt)) {
1540                         struct sock_xprt *transport = container_of(xprt,
1541                                         struct sock_xprt, xprt);
1542
1543                         /* Reset TCP record info */
1544                         transport->tcp_offset = 0;
1545                         transport->tcp_reclen = 0;
1546                         transport->tcp_copied = 0;
1547                         transport->tcp_flags =
1548                                 TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1549                         xprt->connect_cookie++;
1550
1551                         xprt_wake_pending_tasks(xprt, -EAGAIN);
1552                 }
1553                 spin_unlock(&xprt->transport_lock);
1554                 break;
1555         case TCP_FIN_WAIT1:
1556                 /* The client initiated a shutdown of the socket */
1557                 xprt->connect_cookie++;
1558                 xprt->reestablish_timeout = 0;
1559                 set_bit(XPRT_CLOSING, &xprt->state);
1560                 smp_mb__before_atomic();
1561                 clear_bit(XPRT_CONNECTED, &xprt->state);
1562                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1563                 smp_mb__after_atomic();
1564                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1565                 break;
1566         case TCP_CLOSE_WAIT:
1567                 /* The server initiated a shutdown of the socket */
1568                 xprt->connect_cookie++;
1569                 clear_bit(XPRT_CONNECTED, &xprt->state);
1570                 xs_tcp_force_close(xprt);
1571         case TCP_CLOSING:
1572                 /*
1573                  * If the server closed down the connection, make sure that
1574                  * we back off before reconnecting
1575                  */
1576                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1577                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1578                 break;
1579         case TCP_LAST_ACK:
1580                 set_bit(XPRT_CLOSING, &xprt->state);
1581                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1582                 smp_mb__before_atomic();
1583                 clear_bit(XPRT_CONNECTED, &xprt->state);
1584                 smp_mb__after_atomic();
1585                 break;
1586         case TCP_CLOSE:
1587                 xs_tcp_cancel_linger_timeout(xprt);
1588                 xs_sock_mark_closed(xprt);
1589         }
1590  out:
1591         read_unlock_bh(&sk->sk_callback_lock);
1592 }
1593
1594 static void xs_write_space(struct sock *sk)
1595 {
1596         struct socket *sock;
1597         struct rpc_xprt *xprt;
1598
1599         if (unlikely(!(sock = sk->sk_socket)))
1600                 return;
1601         clear_bit(SOCK_NOSPACE, &sock->flags);
1602
1603         if (unlikely(!(xprt = xprt_from_sock(sk))))
1604                 return;
1605         if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1606                 return;
1607
1608         xprt_write_space(xprt);
1609 }
1610
1611 /**
1612  * xs_udp_write_space - callback invoked when socket buffer space
1613  *                             becomes available
1614  * @sk: socket whose state has changed
1615  *
1616  * Called when more output buffer space is available for this socket.
1617  * We try not to wake our writers until they can make "significant"
1618  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1619  * with a bunch of small requests.
1620  */
1621 static void xs_udp_write_space(struct sock *sk)
1622 {
1623         read_lock_bh(&sk->sk_callback_lock);
1624
1625         /* from net/core/sock.c:sock_def_write_space */
1626         if (sock_writeable(sk))
1627                 xs_write_space(sk);
1628
1629         read_unlock_bh(&sk->sk_callback_lock);
1630 }
1631
1632 /**
1633  * xs_tcp_write_space - callback invoked when socket buffer space
1634  *                             becomes available
1635  * @sk: socket whose state has changed
1636  *
1637  * Called when more output buffer space is available for this socket.
1638  * We try not to wake our writers until they can make "significant"
1639  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1640  * with a bunch of small requests.
1641  */
1642 static void xs_tcp_write_space(struct sock *sk)
1643 {
1644         read_lock_bh(&sk->sk_callback_lock);
1645
1646         /* from net/core/stream.c:sk_stream_write_space */
1647         if (sk_stream_is_writeable(sk))
1648                 xs_write_space(sk);
1649
1650         read_unlock_bh(&sk->sk_callback_lock);
1651 }
1652
1653 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1654 {
1655         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1656         struct sock *sk = transport->inet;
1657
1658         if (transport->rcvsize) {
1659                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1660                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1661         }
1662         if (transport->sndsize) {
1663                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1664                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1665                 sk->sk_write_space(sk);
1666         }
1667 }
1668
1669 /**
1670  * xs_udp_set_buffer_size - set send and receive limits
1671  * @xprt: generic transport
1672  * @sndsize: requested size of send buffer, in bytes
1673  * @rcvsize: requested size of receive buffer, in bytes
1674  *
1675  * Set socket send and receive buffer size limits.
1676  */
1677 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1678 {
1679         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1680
1681         transport->sndsize = 0;
1682         if (sndsize)
1683                 transport->sndsize = sndsize + 1024;
1684         transport->rcvsize = 0;
1685         if (rcvsize)
1686                 transport->rcvsize = rcvsize + 1024;
1687
1688         xs_udp_do_set_buffer_size(xprt);
1689 }
1690
1691 /**
1692  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1693  * @task: task that timed out
1694  *
1695  * Adjust the congestion window after a retransmit timeout has occurred.
1696  */
1697 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1698 {
1699         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1700 }
1701
1702 static unsigned short xs_get_random_port(void)
1703 {
1704         unsigned short range = xprt_max_resvport - xprt_min_resvport;
1705         unsigned short rand = (unsigned short) prandom_u32() % range;
1706         return rand + xprt_min_resvport;
1707 }
1708
1709 /**
1710  * xs_set_port - reset the port number in the remote endpoint address
1711  * @xprt: generic transport
1712  * @port: new port number
1713  *
1714  */
1715 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1716 {
1717         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1718
1719         rpc_set_port(xs_addr(xprt), port);
1720         xs_update_peer_port(xprt);
1721 }
1722
1723 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1724 {
1725         unsigned short port = transport->srcport;
1726
1727         if (port == 0 && transport->xprt.resvport)
1728                 port = xs_get_random_port();
1729         return port;
1730 }
1731
1732 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1733 {
1734         if (transport->srcport != 0)
1735                 transport->srcport = 0;
1736         if (!transport->xprt.resvport)
1737                 return 0;
1738         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1739                 return xprt_max_resvport;
1740         return --port;
1741 }
1742 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1743 {
1744         struct sockaddr_storage myaddr;
1745         int err, nloop = 0;
1746         unsigned short port = xs_get_srcport(transport);
1747         unsigned short last;
1748
1749         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1750         do {
1751                 rpc_set_port((struct sockaddr *)&myaddr, port);
1752                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1753                                 transport->xprt.addrlen);
1754                 if (port == 0)
1755                         break;
1756                 if (err == 0) {
1757                         transport->srcport = port;
1758                         break;
1759                 }
1760                 last = port;
1761                 port = xs_next_srcport(transport, port);
1762                 if (port > last)
1763                         nloop++;
1764         } while (err == -EADDRINUSE && nloop != 2);
1765
1766         if (myaddr.ss_family == AF_INET)
1767                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1768                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1769                                 port, err ? "failed" : "ok", err);
1770         else
1771                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1772                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1773                                 port, err ? "failed" : "ok", err);
1774         return err;
1775 }
1776
1777 /*
1778  * We don't support autobind on AF_LOCAL sockets
1779  */
1780 static void xs_local_rpcbind(struct rpc_task *task)
1781 {
1782         rcu_read_lock();
1783         xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
1784         rcu_read_unlock();
1785 }
1786
1787 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1788 {
1789 }
1790
1791 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1792 static struct lock_class_key xs_key[2];
1793 static struct lock_class_key xs_slock_key[2];
1794
1795 static inline void xs_reclassify_socketu(struct socket *sock)
1796 {
1797         struct sock *sk = sock->sk;
1798
1799         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1800                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1801 }
1802
1803 static inline void xs_reclassify_socket4(struct socket *sock)
1804 {
1805         struct sock *sk = sock->sk;
1806
1807         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1808                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1809 }
1810
1811 static inline void xs_reclassify_socket6(struct socket *sock)
1812 {
1813         struct sock *sk = sock->sk;
1814
1815         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1816                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1817 }
1818
1819 static inline void xs_reclassify_socket(int family, struct socket *sock)
1820 {
1821         WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1822         if (sock_owned_by_user(sock->sk))
1823                 return;
1824
1825         switch (family) {
1826         case AF_LOCAL:
1827                 xs_reclassify_socketu(sock);
1828                 break;
1829         case AF_INET:
1830                 xs_reclassify_socket4(sock);
1831                 break;
1832         case AF_INET6:
1833                 xs_reclassify_socket6(sock);
1834                 break;
1835         }
1836 }
1837 #else
1838 static inline void xs_reclassify_socketu(struct socket *sock)
1839 {
1840 }
1841
1842 static inline void xs_reclassify_socket4(struct socket *sock)
1843 {
1844 }
1845
1846 static inline void xs_reclassify_socket6(struct socket *sock)
1847 {
1848 }
1849
1850 static inline void xs_reclassify_socket(int family, struct socket *sock)
1851 {
1852 }
1853 #endif
1854
1855 static void xs_dummy_setup_socket(struct work_struct *work)
1856 {
1857 }
1858
1859 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1860                 struct sock_xprt *transport, int family, int type, int protocol)
1861 {
1862         struct socket *sock;
1863         int err;
1864
1865         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1866         if (err < 0) {
1867                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1868                                 protocol, -err);
1869                 goto out;
1870         }
1871         xs_reclassify_socket(family, sock);
1872
1873         err = xs_bind(transport, sock);
1874         if (err) {
1875                 sock_release(sock);
1876                 goto out;
1877         }
1878
1879         return sock;
1880 out:
1881         return ERR_PTR(err);
1882 }
1883
1884 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1885                                       struct socket *sock)
1886 {
1887         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1888                                                                         xprt);
1889
1890         if (!transport->inet) {
1891                 struct sock *sk = sock->sk;
1892
1893                 write_lock_bh(&sk->sk_callback_lock);
1894
1895                 xs_save_old_callbacks(transport, sk);
1896
1897                 sk->sk_user_data = xprt;
1898                 sk->sk_data_ready = xs_local_data_ready;
1899                 sk->sk_write_space = xs_udp_write_space;
1900                 sk->sk_error_report = xs_error_report;
1901                 sk->sk_allocation = GFP_ATOMIC;
1902
1903                 xprt_clear_connected(xprt);
1904
1905                 /* Reset to new socket */
1906                 transport->sock = sock;
1907                 transport->inet = sk;
1908
1909                 write_unlock_bh(&sk->sk_callback_lock);
1910         }
1911
1912         /* Tell the socket layer to start connecting... */
1913         xprt->stat.connect_count++;
1914         xprt->stat.connect_start = jiffies;
1915         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1916 }
1917
1918 /**
1919  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1920  * @xprt: RPC transport to connect
1921  * @transport: socket transport to connect
1922  * @create_sock: function to create a socket of the correct type
1923  */
1924 static int xs_local_setup_socket(struct sock_xprt *transport)
1925 {
1926         struct rpc_xprt *xprt = &transport->xprt;
1927         struct socket *sock;
1928         int status = -EIO;
1929
1930         current->flags |= PF_FSTRANS;
1931
1932         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1933         status = __sock_create(xprt->xprt_net, AF_LOCAL,
1934                                         SOCK_STREAM, 0, &sock, 1);
1935         if (status < 0) {
1936                 dprintk("RPC:       can't create AF_LOCAL "
1937                         "transport socket (%d).\n", -status);
1938                 goto out;
1939         }
1940         xs_reclassify_socketu(sock);
1941
1942         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1943                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1944
1945         status = xs_local_finish_connecting(xprt, sock);
1946         trace_rpc_socket_connect(xprt, sock, status);
1947         switch (status) {
1948         case 0:
1949                 dprintk("RPC:       xprt %p connected to %s\n",
1950                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1951                 xprt_set_connected(xprt);
1952         case -ENOBUFS:
1953                 break;
1954         case -ENOENT:
1955                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
1956                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1957                 break;
1958         case -ECONNREFUSED:
1959                 dprintk("RPC:       xprt %p: connection refused for %s\n",
1960                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1961                 break;
1962         default:
1963                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1964                                 __func__, -status,
1965                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
1966         }
1967
1968 out:
1969         xprt_clear_connecting(xprt);
1970         xprt_wake_pending_tasks(xprt, status);
1971         current->flags &= ~PF_FSTRANS;
1972         return status;
1973 }
1974
1975 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1976 {
1977         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1978         int ret;
1979
1980          if (RPC_IS_ASYNC(task)) {
1981                 /*
1982                  * We want the AF_LOCAL connect to be resolved in the
1983                  * filesystem namespace of the process making the rpc
1984                  * call.  Thus we connect synchronously.
1985                  *
1986                  * If we want to support asynchronous AF_LOCAL calls,
1987                  * we'll need to figure out how to pass a namespace to
1988                  * connect.
1989                  */
1990                 rpc_exit(task, -ENOTCONN);
1991                 return;
1992         }
1993         ret = xs_local_setup_socket(transport);
1994         if (ret && !RPC_IS_SOFTCONN(task))
1995                 msleep_interruptible(15000);
1996 }
1997
1998 #ifdef CONFIG_SUNRPC_SWAP
1999 static void xs_set_memalloc(struct rpc_xprt *xprt)
2000 {
2001         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2002                         xprt);
2003
2004         if (xprt->swapper)
2005                 sk_set_memalloc(transport->inet);
2006 }
2007
2008 /**
2009  * xs_swapper - Tag this transport as being used for swap.
2010  * @xprt: transport to tag
2011  * @enable: enable/disable
2012  *
2013  */
2014 int xs_swapper(struct rpc_xprt *xprt, int enable)
2015 {
2016         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2017                         xprt);
2018         int err = 0;
2019
2020         if (enable) {
2021                 xprt->swapper++;
2022                 xs_set_memalloc(xprt);
2023         } else if (xprt->swapper) {
2024                 xprt->swapper--;
2025                 sk_clear_memalloc(transport->inet);
2026         }
2027
2028         return err;
2029 }
2030 EXPORT_SYMBOL_GPL(xs_swapper);
2031 #else
2032 static void xs_set_memalloc(struct rpc_xprt *xprt)
2033 {
2034 }
2035 #endif
2036
2037 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2038 {
2039         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2040
2041         if (!transport->inet) {
2042                 struct sock *sk = sock->sk;
2043
2044                 write_lock_bh(&sk->sk_callback_lock);
2045
2046                 xs_save_old_callbacks(transport, sk);
2047
2048                 sk->sk_user_data = xprt;
2049                 sk->sk_data_ready = xs_udp_data_ready;
2050                 sk->sk_write_space = xs_udp_write_space;
2051                 sk->sk_allocation = GFP_ATOMIC;
2052
2053                 xprt_set_connected(xprt);
2054
2055                 /* Reset to new socket */
2056                 transport->sock = sock;
2057                 transport->inet = sk;
2058
2059                 xs_set_memalloc(xprt);
2060
2061                 write_unlock_bh(&sk->sk_callback_lock);
2062         }
2063         xs_udp_do_set_buffer_size(xprt);
2064 }
2065
2066 static void xs_udp_setup_socket(struct work_struct *work)
2067 {
2068         struct sock_xprt *transport =
2069                 container_of(work, struct sock_xprt, connect_worker.work);
2070         struct rpc_xprt *xprt = &transport->xprt;
2071         struct socket *sock = transport->sock;
2072         int status = -EIO;
2073
2074         current->flags |= PF_FSTRANS;
2075
2076         /* Start by resetting any existing state */
2077         xs_reset_transport(transport);
2078         sock = xs_create_sock(xprt, transport,
2079                         xs_addr(xprt)->sa_family, SOCK_DGRAM, IPPROTO_UDP);
2080         if (IS_ERR(sock))
2081                 goto out;
2082
2083         dprintk("RPC:       worker connecting xprt %p via %s to "
2084                                 "%s (port %s)\n", xprt,
2085                         xprt->address_strings[RPC_DISPLAY_PROTO],
2086                         xprt->address_strings[RPC_DISPLAY_ADDR],
2087                         xprt->address_strings[RPC_DISPLAY_PORT]);
2088
2089         xs_udp_finish_connecting(xprt, sock);
2090         trace_rpc_socket_connect(xprt, sock, 0);
2091         status = 0;
2092 out:
2093         xprt_clear_connecting(xprt);
2094         xprt_wake_pending_tasks(xprt, status);
2095         current->flags &= ~PF_FSTRANS;
2096 }
2097
2098 /*
2099  * We need to preserve the port number so the reply cache on the server can
2100  * find our cached RPC replies when we get around to reconnecting.
2101  */
2102 static void xs_abort_connection(struct sock_xprt *transport)
2103 {
2104         int result;
2105         struct sockaddr any;
2106
2107         dprintk("RPC:       disconnecting xprt %p to reuse port\n", transport);
2108
2109         /*
2110          * Disconnect the transport socket by doing a connect operation
2111          * with AF_UNSPEC.  This should return immediately...
2112          */
2113         memset(&any, 0, sizeof(any));
2114         any.sa_family = AF_UNSPEC;
2115         result = kernel_connect(transport->sock, &any, sizeof(any), 0);
2116         trace_rpc_socket_reset_connection(&transport->xprt,
2117                         transport->sock, result);
2118         if (!result)
2119                 xs_sock_reset_connection_flags(&transport->xprt);
2120         dprintk("RPC:       AF_UNSPEC connect return code %d\n", result);
2121 }
2122
2123 static void xs_tcp_reuse_connection(struct sock_xprt *transport)
2124 {
2125         unsigned int state = transport->inet->sk_state;
2126
2127         if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) {
2128                 /* we don't need to abort the connection if the socket
2129                  * hasn't undergone a shutdown
2130                  */
2131                 if (transport->inet->sk_shutdown == 0)
2132                         return;
2133                 dprintk("RPC:       %s: TCP_CLOSEd and sk_shutdown set to %d\n",
2134                                 __func__, transport->inet->sk_shutdown);
2135         }
2136         if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
2137                 /* we don't need to abort the connection if the socket
2138                  * hasn't undergone a shutdown
2139                  */
2140                 if (transport->inet->sk_shutdown == 0)
2141                         return;
2142                 dprintk("RPC:       %s: ESTABLISHED/SYN_SENT "
2143                                 "sk_shutdown set to %d\n",
2144                                 __func__, transport->inet->sk_shutdown);
2145         }
2146         xs_abort_connection(transport);
2147 }
2148
2149 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2150 {
2151         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2152         int ret = -ENOTCONN;
2153
2154         if (!transport->inet) {
2155                 struct sock *sk = sock->sk;
2156                 unsigned int keepidle = xprt->timeout->to_initval / HZ;
2157                 unsigned int keepcnt = xprt->timeout->to_retries + 1;
2158                 unsigned int opt_on = 1;
2159
2160                 /* TCP Keepalive options */
2161                 kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2162                                 (char *)&opt_on, sizeof(opt_on));
2163                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2164                                 (char *)&keepidle, sizeof(keepidle));
2165                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2166                                 (char *)&keepidle, sizeof(keepidle));
2167                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2168                                 (char *)&keepcnt, sizeof(keepcnt));
2169
2170                 write_lock_bh(&sk->sk_callback_lock);
2171
2172                 xs_save_old_callbacks(transport, sk);
2173
2174                 sk->sk_user_data = xprt;
2175                 sk->sk_data_ready = xs_tcp_data_ready;
2176                 sk->sk_state_change = xs_tcp_state_change;
2177                 sk->sk_write_space = xs_tcp_write_space;
2178                 sk->sk_error_report = xs_error_report;
2179                 sk->sk_allocation = GFP_ATOMIC;
2180
2181                 /* socket options */
2182                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
2183                 sock_reset_flag(sk, SOCK_LINGER);
2184                 tcp_sk(sk)->linger2 = 0;
2185                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2186
2187                 xprt_clear_connected(xprt);
2188
2189                 /* Reset to new socket */
2190                 transport->sock = sock;
2191                 transport->inet = sk;
2192
2193                 write_unlock_bh(&sk->sk_callback_lock);
2194         }
2195
2196         if (!xprt_bound(xprt))
2197                 goto out;
2198
2199         xs_set_memalloc(xprt);
2200
2201         /* Tell the socket layer to start connecting... */
2202         xprt->stat.connect_count++;
2203         xprt->stat.connect_start = jiffies;
2204         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2205         switch (ret) {
2206         case 0:
2207         case -EINPROGRESS:
2208                 /* SYN_SENT! */
2209                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2210                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2211         }
2212 out:
2213         return ret;
2214 }
2215
2216 /**
2217  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2218  * @xprt: RPC transport to connect
2219  * @transport: socket transport to connect
2220  * @create_sock: function to create a socket of the correct type
2221  *
2222  * Invoked by a work queue tasklet.
2223  */
2224 static void xs_tcp_setup_socket(struct work_struct *work)
2225 {
2226         struct sock_xprt *transport =
2227                 container_of(work, struct sock_xprt, connect_worker.work);
2228         struct socket *sock = transport->sock;
2229         struct rpc_xprt *xprt = &transport->xprt;
2230         int status = -EIO;
2231
2232         current->flags |= PF_FSTRANS;
2233
2234         if (!sock) {
2235                 clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
2236                 sock = xs_create_sock(xprt, transport,
2237                                 xs_addr(xprt)->sa_family, SOCK_STREAM, IPPROTO_TCP);
2238                 if (IS_ERR(sock)) {
2239                         status = PTR_ERR(sock);
2240                         goto out;
2241                 }
2242         } else {
2243                 int abort_and_exit;
2244
2245                 abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
2246                                 &xprt->state);
2247                 /* "close" the socket, preserving the local port */
2248                 xs_tcp_reuse_connection(transport);
2249
2250                 if (abort_and_exit)
2251                         goto out_eagain;
2252         }
2253
2254         dprintk("RPC:       worker connecting xprt %p via %s to "
2255                                 "%s (port %s)\n", xprt,
2256                         xprt->address_strings[RPC_DISPLAY_PROTO],
2257                         xprt->address_strings[RPC_DISPLAY_ADDR],
2258                         xprt->address_strings[RPC_DISPLAY_PORT]);
2259
2260         status = xs_tcp_finish_connecting(xprt, sock);
2261         trace_rpc_socket_connect(xprt, sock, status);
2262         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2263                         xprt, -status, xprt_connected(xprt),
2264                         sock->sk->sk_state);
2265         switch (status) {
2266         default:
2267                 printk("%s: connect returned unhandled error %d\n",
2268                         __func__, status);
2269         case -EADDRNOTAVAIL:
2270                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2271                  * and retry
2272                  */
2273                 xs_tcp_force_close(xprt);
2274                 break;
2275         case 0:
2276         case -EINPROGRESS:
2277         case -EALREADY:
2278                 xprt_clear_connecting(xprt);
2279                 current->flags &= ~PF_FSTRANS;
2280                 return;
2281         case -EINVAL:
2282                 /* Happens, for instance, if the user specified a link
2283                  * local IPv6 address without a scope-id.
2284                  */
2285         case -ECONNREFUSED:
2286         case -ECONNRESET:
2287         case -ENETUNREACH:
2288         case -ENOBUFS:
2289                 /* retry with existing socket, after a delay */
2290                 goto out;
2291         }
2292 out_eagain:
2293         status = -EAGAIN;
2294 out:
2295         xprt_clear_connecting(xprt);
2296         xprt_wake_pending_tasks(xprt, status);
2297         current->flags &= ~PF_FSTRANS;
2298 }
2299
2300 /**
2301  * xs_connect - connect a socket to a remote endpoint
2302  * @xprt: pointer to transport structure
2303  * @task: address of RPC task that manages state of connect request
2304  *
2305  * TCP: If the remote end dropped the connection, delay reconnecting.
2306  *
2307  * UDP socket connects are synchronous, but we use a work queue anyway
2308  * to guarantee that even unprivileged user processes can set up a
2309  * socket on a privileged port.
2310  *
2311  * If a UDP socket connect fails, the delay behavior here prevents
2312  * retry floods (hard mounts).
2313  */
2314 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2315 {
2316         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2317
2318         if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2319                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2320                                 "seconds\n",
2321                                 xprt, xprt->reestablish_timeout / HZ);
2322                 queue_delayed_work(rpciod_workqueue,
2323                                    &transport->connect_worker,
2324                                    xprt->reestablish_timeout);
2325                 xprt->reestablish_timeout <<= 1;
2326                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2327                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2328                 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2329                         xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2330         } else {
2331                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2332                 queue_delayed_work(rpciod_workqueue,
2333                                    &transport->connect_worker, 0);
2334         }
2335 }
2336
2337 /**
2338  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2339  * @xprt: rpc_xprt struct containing statistics
2340  * @seq: output file
2341  *
2342  */
2343 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2344 {
2345         long idle_time = 0;
2346
2347         if (xprt_connected(xprt))
2348                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2349
2350         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2351                         "%llu %llu %lu %llu %llu\n",
2352                         xprt->stat.bind_count,
2353                         xprt->stat.connect_count,
2354                         xprt->stat.connect_time,
2355                         idle_time,
2356                         xprt->stat.sends,
2357                         xprt->stat.recvs,
2358                         xprt->stat.bad_xids,
2359                         xprt->stat.req_u,
2360                         xprt->stat.bklog_u,
2361                         xprt->stat.max_slots,
2362                         xprt->stat.sending_u,
2363                         xprt->stat.pending_u);
2364 }
2365
2366 /**
2367  * xs_udp_print_stats - display UDP socket-specifc stats
2368  * @xprt: rpc_xprt struct containing statistics
2369  * @seq: output file
2370  *
2371  */
2372 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2373 {
2374         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2375
2376         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2377                         "%lu %llu %llu\n",
2378                         transport->srcport,
2379                         xprt->stat.bind_count,
2380                         xprt->stat.sends,
2381                         xprt->stat.recvs,
2382                         xprt->stat.bad_xids,
2383                         xprt->stat.req_u,
2384                         xprt->stat.bklog_u,
2385                         xprt->stat.max_slots,
2386                         xprt->stat.sending_u,
2387                         xprt->stat.pending_u);
2388 }
2389
2390 /**
2391  * xs_tcp_print_stats - display TCP socket-specifc stats
2392  * @xprt: rpc_xprt struct containing statistics
2393  * @seq: output file
2394  *
2395  */
2396 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2397 {
2398         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2399         long idle_time = 0;
2400
2401         if (xprt_connected(xprt))
2402                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2403
2404         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2405                         "%llu %llu %lu %llu %llu\n",
2406                         transport->srcport,
2407                         xprt->stat.bind_count,
2408                         xprt->stat.connect_count,
2409                         xprt->stat.connect_time,
2410                         idle_time,
2411                         xprt->stat.sends,
2412                         xprt->stat.recvs,
2413                         xprt->stat.bad_xids,
2414                         xprt->stat.req_u,
2415                         xprt->stat.bklog_u,
2416                         xprt->stat.max_slots,
2417                         xprt->stat.sending_u,
2418                         xprt->stat.pending_u);
2419 }
2420
2421 /*
2422  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2423  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2424  * to use the server side send routines.
2425  */
2426 static void *bc_malloc(struct rpc_task *task, size_t size)
2427 {
2428         struct page *page;
2429         struct rpc_buffer *buf;
2430
2431         WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2432         if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2433                 return NULL;
2434
2435         page = alloc_page(GFP_KERNEL);
2436         if (!page)
2437                 return NULL;
2438
2439         buf = page_address(page);
2440         buf->len = PAGE_SIZE;
2441
2442         return buf->data;
2443 }
2444
2445 /*
2446  * Free the space allocated in the bc_alloc routine
2447  */
2448 static void bc_free(void *buffer)
2449 {
2450         struct rpc_buffer *buf;
2451
2452         if (!buffer)
2453                 return;
2454
2455         buf = container_of(buffer, struct rpc_buffer, data);
2456         free_page((unsigned long)buf);
2457 }
2458
2459 /*
2460  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2461  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2462  */
2463 static int bc_sendto(struct rpc_rqst *req)
2464 {
2465         int len;
2466         struct xdr_buf *xbufp = &req->rq_snd_buf;
2467         struct rpc_xprt *xprt = req->rq_xprt;
2468         struct sock_xprt *transport =
2469                                 container_of(xprt, struct sock_xprt, xprt);
2470         struct socket *sock = transport->sock;
2471         unsigned long headoff;
2472         unsigned long tailoff;
2473
2474         xs_encode_stream_record_marker(xbufp);
2475
2476         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2477         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2478         len = svc_send_common(sock, xbufp,
2479                               virt_to_page(xbufp->head[0].iov_base), headoff,
2480                               xbufp->tail[0].iov_base, tailoff);
2481
2482         if (len != xbufp->len) {
2483                 printk(KERN_NOTICE "Error sending entire callback!\n");
2484                 len = -EAGAIN;
2485         }
2486
2487         return len;
2488 }
2489
2490 /*
2491  * The send routine. Borrows from svc_send
2492  */
2493 static int bc_send_request(struct rpc_task *task)
2494 {
2495         struct rpc_rqst *req = task->tk_rqstp;
2496         struct svc_xprt *xprt;
2497         u32                     len;
2498
2499         dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2500         /*
2501          * Get the server socket associated with this callback xprt
2502          */
2503         xprt = req->rq_xprt->bc_xprt;
2504
2505         /*
2506          * Grab the mutex to serialize data as the connection is shared
2507          * with the fore channel
2508          */
2509         if (!mutex_trylock(&xprt->xpt_mutex)) {
2510                 rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2511                 if (!mutex_trylock(&xprt->xpt_mutex))
2512                         return -EAGAIN;
2513                 rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2514         }
2515         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2516                 len = -ENOTCONN;
2517         else
2518                 len = bc_sendto(req);
2519         mutex_unlock(&xprt->xpt_mutex);
2520
2521         if (len > 0)
2522                 len = 0;
2523
2524         return len;
2525 }
2526
2527 /*
2528  * The close routine. Since this is client initiated, we do nothing
2529  */
2530
2531 static void bc_close(struct rpc_xprt *xprt)
2532 {
2533 }
2534
2535 /*
2536  * The xprt destroy routine. Again, because this connection is client
2537  * initiated, we do nothing
2538  */
2539
2540 static void bc_destroy(struct rpc_xprt *xprt)
2541 {
2542         dprintk("RPC:       bc_destroy xprt %p\n", xprt);
2543
2544         xs_xprt_free(xprt);
2545         module_put(THIS_MODULE);
2546 }
2547
2548 static struct rpc_xprt_ops xs_local_ops = {
2549         .reserve_xprt           = xprt_reserve_xprt,
2550         .release_xprt           = xs_tcp_release_xprt,
2551         .alloc_slot             = xprt_alloc_slot,
2552         .rpcbind                = xs_local_rpcbind,
2553         .set_port               = xs_local_set_port,
2554         .connect                = xs_local_connect,
2555         .buf_alloc              = rpc_malloc,
2556         .buf_free               = rpc_free,
2557         .send_request           = xs_local_send_request,
2558         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2559         .close                  = xs_close,
2560         .destroy                = xs_destroy,
2561         .print_stats            = xs_local_print_stats,
2562 };
2563
2564 static struct rpc_xprt_ops xs_udp_ops = {
2565         .set_buffer_size        = xs_udp_set_buffer_size,
2566         .reserve_xprt           = xprt_reserve_xprt_cong,
2567         .release_xprt           = xprt_release_xprt_cong,
2568         .alloc_slot             = xprt_alloc_slot,
2569         .rpcbind                = rpcb_getport_async,
2570         .set_port               = xs_set_port,
2571         .connect                = xs_connect,
2572         .buf_alloc              = rpc_malloc,
2573         .buf_free               = rpc_free,
2574         .send_request           = xs_udp_send_request,
2575         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
2576         .timer                  = xs_udp_timer,
2577         .release_request        = xprt_release_rqst_cong,
2578         .close                  = xs_close,
2579         .destroy                = xs_destroy,
2580         .print_stats            = xs_udp_print_stats,
2581 };
2582
2583 static struct rpc_xprt_ops xs_tcp_ops = {
2584         .reserve_xprt           = xprt_reserve_xprt,
2585         .release_xprt           = xs_tcp_release_xprt,
2586         .alloc_slot             = xprt_lock_and_alloc_slot,
2587         .rpcbind                = rpcb_getport_async,
2588         .set_port               = xs_set_port,
2589         .connect                = xs_connect,
2590         .buf_alloc              = rpc_malloc,
2591         .buf_free               = rpc_free,
2592         .send_request           = xs_tcp_send_request,
2593         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2594         .close                  = xs_tcp_close,
2595         .destroy                = xs_destroy,
2596         .print_stats            = xs_tcp_print_stats,
2597 };
2598
2599 /*
2600  * The rpc_xprt_ops for the server backchannel
2601  */
2602
2603 static struct rpc_xprt_ops bc_tcp_ops = {
2604         .reserve_xprt           = xprt_reserve_xprt,
2605         .release_xprt           = xprt_release_xprt,
2606         .alloc_slot             = xprt_alloc_slot,
2607         .buf_alloc              = bc_malloc,
2608         .buf_free               = bc_free,
2609         .send_request           = bc_send_request,
2610         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2611         .close                  = bc_close,
2612         .destroy                = bc_destroy,
2613         .print_stats            = xs_tcp_print_stats,
2614 };
2615
2616 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2617 {
2618         static const struct sockaddr_in sin = {
2619                 .sin_family             = AF_INET,
2620                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2621         };
2622         static const struct sockaddr_in6 sin6 = {
2623                 .sin6_family            = AF_INET6,
2624                 .sin6_addr              = IN6ADDR_ANY_INIT,
2625         };
2626
2627         switch (family) {
2628         case AF_LOCAL:
2629                 break;
2630         case AF_INET:
2631                 memcpy(sap, &sin, sizeof(sin));
2632                 break;
2633         case AF_INET6:
2634                 memcpy(sap, &sin6, sizeof(sin6));
2635                 break;
2636         default:
2637                 dprintk("RPC:       %s: Bad address family\n", __func__);
2638                 return -EAFNOSUPPORT;
2639         }
2640         return 0;
2641 }
2642
2643 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2644                                       unsigned int slot_table_size,
2645                                       unsigned int max_slot_table_size)
2646 {
2647         struct rpc_xprt *xprt;
2648         struct sock_xprt *new;
2649
2650         if (args->addrlen > sizeof(xprt->addr)) {
2651                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2652                 return ERR_PTR(-EBADF);
2653         }
2654
2655         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2656                         max_slot_table_size);
2657         if (xprt == NULL) {
2658                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2659                                 "rpc_xprt\n");
2660                 return ERR_PTR(-ENOMEM);
2661         }
2662
2663         new = container_of(xprt, struct sock_xprt, xprt);
2664         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2665         xprt->addrlen = args->addrlen;
2666         if (args->srcaddr)
2667                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2668         else {
2669                 int err;
2670                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2671                                         (struct sockaddr *)&new->srcaddr);
2672                 if (err != 0) {
2673                         xprt_free(xprt);
2674                         return ERR_PTR(err);
2675                 }
2676         }
2677
2678         return xprt;
2679 }
2680
2681 static const struct rpc_timeout xs_local_default_timeout = {
2682         .to_initval = 10 * HZ,
2683         .to_maxval = 10 * HZ,
2684         .to_retries = 2,
2685 };
2686
2687 /**
2688  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2689  * @args: rpc transport creation arguments
2690  *
2691  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2692  */
2693 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2694 {
2695         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2696         struct sock_xprt *transport;
2697         struct rpc_xprt *xprt;
2698         struct rpc_xprt *ret;
2699
2700         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2701                         xprt_max_tcp_slot_table_entries);
2702         if (IS_ERR(xprt))
2703                 return xprt;
2704         transport = container_of(xprt, struct sock_xprt, xprt);
2705
2706         xprt->prot = 0;
2707         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2708         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2709
2710         xprt->bind_timeout = XS_BIND_TO;
2711         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2712         xprt->idle_timeout = XS_IDLE_DISC_TO;
2713
2714         xprt->ops = &xs_local_ops;
2715         xprt->timeout = &xs_local_default_timeout;
2716
2717         INIT_DELAYED_WORK(&transport->connect_worker,
2718                         xs_dummy_setup_socket);
2719
2720         switch (sun->sun_family) {
2721         case AF_LOCAL:
2722                 if (sun->sun_path[0] != '/') {
2723                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2724                                         sun->sun_path);
2725                         ret = ERR_PTR(-EINVAL);
2726                         goto out_err;
2727                 }
2728                 xprt_set_bound(xprt);
2729                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2730                 ret = ERR_PTR(xs_local_setup_socket(transport));
2731                 if (ret)
2732                         goto out_err;
2733                 break;
2734         default:
2735                 ret = ERR_PTR(-EAFNOSUPPORT);
2736                 goto out_err;
2737         }
2738
2739         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2740                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2741
2742         if (try_module_get(THIS_MODULE))
2743                 return xprt;
2744         ret = ERR_PTR(-EINVAL);
2745 out_err:
2746         xs_xprt_free(xprt);
2747         return ret;
2748 }
2749
2750 static const struct rpc_timeout xs_udp_default_timeout = {
2751         .to_initval = 5 * HZ,
2752         .to_maxval = 30 * HZ,
2753         .to_increment = 5 * HZ,
2754         .to_retries = 5,
2755 };
2756
2757 /**
2758  * xs_setup_udp - Set up transport to use a UDP socket
2759  * @args: rpc transport creation arguments
2760  *
2761  */
2762 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2763 {
2764         struct sockaddr *addr = args->dstaddr;
2765         struct rpc_xprt *xprt;
2766         struct sock_xprt *transport;
2767         struct rpc_xprt *ret;
2768
2769         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2770                         xprt_udp_slot_table_entries);
2771         if (IS_ERR(xprt))
2772                 return xprt;
2773         transport = container_of(xprt, struct sock_xprt, xprt);
2774
2775         xprt->prot = IPPROTO_UDP;
2776         xprt->tsh_size = 0;
2777         /* XXX: header size can vary due to auth type, IPv6, etc. */
2778         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2779
2780         xprt->bind_timeout = XS_BIND_TO;
2781         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2782         xprt->idle_timeout = XS_IDLE_DISC_TO;
2783
2784         xprt->ops = &xs_udp_ops;
2785
2786         xprt->timeout = &xs_udp_default_timeout;
2787
2788         switch (addr->sa_family) {
2789         case AF_INET:
2790                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2791                         xprt_set_bound(xprt);
2792
2793                 INIT_DELAYED_WORK(&transport->connect_worker,
2794                                         xs_udp_setup_socket);
2795                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2796                 break;
2797         case AF_INET6:
2798                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2799                         xprt_set_bound(xprt);
2800
2801                 INIT_DELAYED_WORK(&transport->connect_worker,
2802                                         xs_udp_setup_socket);
2803                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2804                 break;
2805         default:
2806                 ret = ERR_PTR(-EAFNOSUPPORT);
2807                 goto out_err;
2808         }
2809
2810         if (xprt_bound(xprt))
2811                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2812                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2813                                 xprt->address_strings[RPC_DISPLAY_PORT],
2814                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2815         else
2816                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2817                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2818                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2819
2820         if (try_module_get(THIS_MODULE))
2821                 return xprt;
2822         ret = ERR_PTR(-EINVAL);
2823 out_err:
2824         xs_xprt_free(xprt);
2825         return ret;
2826 }
2827
2828 static const struct rpc_timeout xs_tcp_default_timeout = {
2829         .to_initval = 60 * HZ,
2830         .to_maxval = 60 * HZ,
2831         .to_retries = 2,
2832 };
2833
2834 /**
2835  * xs_setup_tcp - Set up transport to use a TCP socket
2836  * @args: rpc transport creation arguments
2837  *
2838  */
2839 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2840 {
2841         struct sockaddr *addr = args->dstaddr;
2842         struct rpc_xprt *xprt;
2843         struct sock_xprt *transport;
2844         struct rpc_xprt *ret;
2845         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2846
2847         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2848                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2849
2850         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2851                         max_slot_table_size);
2852         if (IS_ERR(xprt))
2853                 return xprt;
2854         transport = container_of(xprt, struct sock_xprt, xprt);
2855
2856         xprt->prot = IPPROTO_TCP;
2857         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2858         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2859
2860         xprt->bind_timeout = XS_BIND_TO;
2861         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2862         xprt->idle_timeout = XS_IDLE_DISC_TO;
2863
2864         xprt->ops = &xs_tcp_ops;
2865         xprt->timeout = &xs_tcp_default_timeout;
2866
2867         switch (addr->sa_family) {
2868         case AF_INET:
2869                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2870                         xprt_set_bound(xprt);
2871
2872                 INIT_DELAYED_WORK(&transport->connect_worker,
2873                                         xs_tcp_setup_socket);
2874                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2875                 break;
2876         case AF_INET6:
2877                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2878                         xprt_set_bound(xprt);
2879
2880                 INIT_DELAYED_WORK(&transport->connect_worker,
2881                                         xs_tcp_setup_socket);
2882                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2883                 break;
2884         default:
2885                 ret = ERR_PTR(-EAFNOSUPPORT);
2886                 goto out_err;
2887         }
2888
2889         if (xprt_bound(xprt))
2890                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2891                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2892                                 xprt->address_strings[RPC_DISPLAY_PORT],
2893                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2894         else
2895                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2896                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2897                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2898
2899         if (try_module_get(THIS_MODULE))
2900                 return xprt;
2901         ret = ERR_PTR(-EINVAL);
2902 out_err:
2903         xs_xprt_free(xprt);
2904         return ret;
2905 }
2906
2907 /**
2908  * xs_setup_bc_tcp - Set up transport to use a TCP backchannel socket
2909  * @args: rpc transport creation arguments
2910  *
2911  */
2912 static struct rpc_xprt *xs_setup_bc_tcp(struct xprt_create *args)
2913 {
2914         struct sockaddr *addr = args->dstaddr;
2915         struct rpc_xprt *xprt;
2916         struct sock_xprt *transport;
2917         struct svc_sock *bc_sock;
2918         struct rpc_xprt *ret;
2919
2920         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2921                         xprt_tcp_slot_table_entries);
2922         if (IS_ERR(xprt))
2923                 return xprt;
2924         transport = container_of(xprt, struct sock_xprt, xprt);
2925
2926         xprt->prot = IPPROTO_TCP;
2927         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2928         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2929         xprt->timeout = &xs_tcp_default_timeout;
2930
2931         /* backchannel */
2932         xprt_set_bound(xprt);
2933         xprt->bind_timeout = 0;
2934         xprt->reestablish_timeout = 0;
2935         xprt->idle_timeout = 0;
2936
2937         xprt->ops = &bc_tcp_ops;
2938
2939         switch (addr->sa_family) {
2940         case AF_INET:
2941                 xs_format_peer_addresses(xprt, "tcp",
2942                                          RPCBIND_NETID_TCP);
2943                 break;
2944         case AF_INET6:
2945                 xs_format_peer_addresses(xprt, "tcp",
2946                                    RPCBIND_NETID_TCP6);
2947                 break;
2948         default:
2949                 ret = ERR_PTR(-EAFNOSUPPORT);
2950                 goto out_err;
2951         }
2952
2953         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2954                         xprt->address_strings[RPC_DISPLAY_ADDR],
2955                         xprt->address_strings[RPC_DISPLAY_PORT],
2956                         xprt->address_strings[RPC_DISPLAY_PROTO]);
2957
2958         /*
2959          * Once we've associated a backchannel xprt with a connection,
2960          * we want to keep it around as long as the connection lasts,
2961          * in case we need to start using it for a backchannel again;
2962          * this reference won't be dropped until bc_xprt is destroyed.
2963          */
2964         xprt_get(xprt);
2965         args->bc_xprt->xpt_bc_xprt = xprt;
2966         xprt->bc_xprt = args->bc_xprt;
2967         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2968         transport->sock = bc_sock->sk_sock;
2969         transport->inet = bc_sock->sk_sk;
2970
2971         /*
2972          * Since we don't want connections for the backchannel, we set
2973          * the xprt status to connected
2974          */
2975         xprt_set_connected(xprt);
2976
2977         if (try_module_get(THIS_MODULE))
2978                 return xprt;
2979
2980         args->bc_xprt->xpt_bc_xprt = NULL;
2981         xprt_put(xprt);
2982         ret = ERR_PTR(-EINVAL);
2983 out_err:
2984         xs_xprt_free(xprt);
2985         return ret;
2986 }
2987
2988 static struct xprt_class        xs_local_transport = {
2989         .list           = LIST_HEAD_INIT(xs_local_transport.list),
2990         .name           = "named UNIX socket",
2991         .owner          = THIS_MODULE,
2992         .ident          = XPRT_TRANSPORT_LOCAL,
2993         .setup          = xs_setup_local,
2994 };
2995
2996 static struct xprt_class        xs_udp_transport = {
2997         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
2998         .name           = "udp",
2999         .owner          = THIS_MODULE,
3000         .ident          = XPRT_TRANSPORT_UDP,
3001         .setup          = xs_setup_udp,
3002 };
3003
3004 static struct xprt_class        xs_tcp_transport = {
3005         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3006         .name           = "tcp",
3007         .owner          = THIS_MODULE,
3008         .ident          = XPRT_TRANSPORT_TCP,
3009         .setup          = xs_setup_tcp,
3010 };
3011
3012 static struct xprt_class        xs_bc_tcp_transport = {
3013         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3014         .name           = "tcp NFSv4.1 backchannel",
3015         .owner          = THIS_MODULE,
3016         .ident          = XPRT_TRANSPORT_BC_TCP,
3017         .setup          = xs_setup_bc_tcp,
3018 };
3019
3020 /**
3021  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3022  *
3023  */
3024 int init_socket_xprt(void)
3025 {
3026 #ifdef RPC_DEBUG
3027         if (!sunrpc_table_header)
3028                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3029 #endif
3030
3031         xprt_register_transport(&xs_local_transport);
3032         xprt_register_transport(&xs_udp_transport);
3033         xprt_register_transport(&xs_tcp_transport);
3034         xprt_register_transport(&xs_bc_tcp_transport);
3035
3036         return 0;
3037 }
3038
3039 /**
3040  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3041  *
3042  */
3043 void cleanup_socket_xprt(void)
3044 {
3045 #ifdef RPC_DEBUG
3046         if (sunrpc_table_header) {
3047                 unregister_sysctl_table(sunrpc_table_header);
3048                 sunrpc_table_header = NULL;
3049         }
3050 #endif
3051
3052         xprt_unregister_transport(&xs_local_transport);
3053         xprt_unregister_transport(&xs_udp_transport);
3054         xprt_unregister_transport(&xs_tcp_transport);
3055         xprt_unregister_transport(&xs_bc_tcp_transport);
3056 }
3057
3058 static int param_set_uint_minmax(const char *val,
3059                 const struct kernel_param *kp,
3060                 unsigned int min, unsigned int max)
3061 {
3062         unsigned int num;
3063         int ret;
3064
3065         if (!val)
3066                 return -EINVAL;
3067         ret = kstrtouint(val, 0, &num);
3068         if (ret == -EINVAL || num < min || num > max)
3069                 return -EINVAL;
3070         *((unsigned int *)kp->arg) = num;
3071         return 0;
3072 }
3073
3074 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3075 {
3076         return param_set_uint_minmax(val, kp,
3077                         RPC_MIN_RESVPORT,
3078                         RPC_MAX_RESVPORT);
3079 }
3080
3081 static struct kernel_param_ops param_ops_portnr = {
3082         .set = param_set_portnr,
3083         .get = param_get_uint,
3084 };
3085
3086 #define param_check_portnr(name, p) \
3087         __param_check(name, p, unsigned int);
3088
3089 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3090 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3091
3092 static int param_set_slot_table_size(const char *val,
3093                                      const struct kernel_param *kp)
3094 {
3095         return param_set_uint_minmax(val, kp,
3096                         RPC_MIN_SLOT_TABLE,
3097                         RPC_MAX_SLOT_TABLE);
3098 }
3099
3100 static struct kernel_param_ops param_ops_slot_table_size = {
3101         .set = param_set_slot_table_size,
3102         .get = param_get_uint,
3103 };
3104
3105 #define param_check_slot_table_size(name, p) \
3106         __param_check(name, p, unsigned int);
3107
3108 static int param_set_max_slot_table_size(const char *val,
3109                                      const struct kernel_param *kp)
3110 {
3111         return param_set_uint_minmax(val, kp,
3112                         RPC_MIN_SLOT_TABLE,
3113                         RPC_MAX_SLOT_TABLE_LIMIT);
3114 }
3115
3116 static struct kernel_param_ops param_ops_max_slot_table_size = {
3117         .set = param_set_max_slot_table_size,
3118         .get = param_get_uint,
3119 };
3120
3121 #define param_check_max_slot_table_size(name, p) \
3122         __param_check(name, p, unsigned int);
3123
3124 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3125                    slot_table_size, 0644);
3126 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3127                    max_slot_table_size, 0644);
3128 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3129                    slot_table_size, 0644);
3130