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