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 *, int);
 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         int ret = -EAGAIN;
 514
 515         dprintk("RPC: %5u xmit incomplete (%u left of %u)\n",
 516                         task->tk_pid, req->rq_slen - req->rq_bytes_sent,
 517                         req->rq_slen);
 518
 519         /* Protect against races with write_space */
 520         spin_lock_bh(&xprt->transport_lock);
 521
 522         /* Don't race with disconnect */
 523         if (xprt_connected(xprt)) {
 524                 if (test_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags)) {
 525                         /*
 526                          * Notify TCP that we're limited by the application
 527                          * window size
 528                          */
 529                         set_bit(SOCK_NOSPACE, &transport->sock->flags);
 530                         transport->inet->sk_write_pending++;
 531                         /* ...and wait for more buffer space */
 532                         xprt_wait_for_buffer_space(task, xs_nospace_callback);
 533                 }
 534         } else {
 535                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 536                 ret = -ENOTCONN;
 537         }
 538
 539         spin_unlock_bh(&xprt->transport_lock);
 540         return ret;
 541 }
 542
 543 /*
 544  * Construct a stream transport record marker in @buf.
 545  */
 546 static inline void xs_encode_stream_record_marker(struct xdr_buf *buf)
 547 {
 548         u32 reclen = buf->len - sizeof(rpc_fraghdr);
 549         rpc_fraghdr *base = buf->head[0].iov_base;
 550         *base = cpu_to_be32(RPC_LAST_STREAM_FRAGMENT | reclen);
 551 }
 552
 553 /**
 554  * xs_local_send_request - write an RPC request to an AF_LOCAL socket
 555  * @task: RPC task that manages the state of an RPC request
 556  *
 557  * Return values:
 558  *        0:    The request has been sent
 559  *   EAGAIN:    The socket was blocked, please call again later to
 560  *              complete the request
 561  * ENOTCONN:    Caller needs to invoke connect logic then call again
 562  *    other:    Some other error occured, the request was not sent
 563  */
 564 static int xs_local_send_request(struct rpc_task *task)
 565 {
 566         struct rpc_rqst *req = task->tk_rqstp;
 567         struct rpc_xprt *xprt = req->rq_xprt;
 568         struct sock_xprt *transport =
 569                                 container_of(xprt, struct sock_xprt, xprt);
 570         struct xdr_buf *xdr = &req->rq_snd_buf;
 571         int status;
 572
 573         xs_encode_stream_record_marker(&req->rq_snd_buf);
 574
 575         xs_pktdump("packet data:",
 576                         req->rq_svec->iov_base, req->rq_svec->iov_len);
 577
 578         status = xs_sendpages(transport->sock, NULL, 0,
 579                                                 xdr, req->rq_bytes_sent, true);
 580         dprintk("RPC:       %s(%u) = %d\n",
 581                         __func__, xdr->len - req->rq_bytes_sent, status);
 582         if (likely(status >= 0)) {
 583                 req->rq_bytes_sent += status;
 584                 req->rq_xmit_bytes_sent += status;
 585                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 586                         req->rq_bytes_sent = 0;
 587                         return 0;
 588                 }
 589                 status = -EAGAIN;
 590         }
 591
 592         switch (status) {
 593         case -EAGAIN:
 594                 status = xs_nospace(task);
 595                 break;
 596         default:
 597                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 598                         -status);
 599         case -EPIPE:
 600                 xs_close(xprt);
 601                 status = -ENOTCONN;
 602         }
 603
 604         return status;
 605 }
 606
 607 /**
 608  * xs_udp_send_request - write an RPC request to a UDP socket
 609  * @task: address of RPC task that manages the state of an RPC request
 610  *
 611  * Return values:
 612  *        0:    The request has been sent
 613  *   EAGAIN:    The socket was blocked, please call again later to
 614  *              complete the request
 615  * ENOTCONN:    Caller needs to invoke connect logic then call again
 616  *    other:    Some other error occurred, the request was not sent
 617  */
 618 static int xs_udp_send_request(struct rpc_task *task)
 619 {
 620         struct rpc_rqst *req = task->tk_rqstp;
 621         struct rpc_xprt *xprt = req->rq_xprt;
 622         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 623         struct xdr_buf *xdr = &req->rq_snd_buf;
 624         int status;
 625
 626         xs_pktdump("packet data:",
 627                                 req->rq_svec->iov_base,
 628                                 req->rq_svec->iov_len);
 629
 630         if (!xprt_bound(xprt))
 631                 return -ENOTCONN;
 632         status = xs_sendpages(transport->sock,
 633                               xs_addr(xprt),
 634                               xprt->addrlen, xdr,
 635                               req->rq_bytes_sent, true);
 636
 637         dprintk("RPC:       xs_udp_send_request(%u) = %d\n",
 638                         xdr->len - req->rq_bytes_sent, status);
 639
 640         if (status >= 0) {
 641                 req->rq_xmit_bytes_sent += status;
 642                 if (status >= req->rq_slen)
 643                         return 0;
 644                 /* Still some bytes left; set up for a retry later. */
 645                 status = -EAGAIN;
 646         }
 647
 648         switch (status) {
 649         case -ENOTSOCK:
 650                 status = -ENOTCONN;
 651                 /* Should we call xs_close() here? */
 652                 break;
 653         case -EAGAIN:
 654                 status = xs_nospace(task);
 655                 break;
 656         default:
 657                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 658                         -status);
 659         case -ENETUNREACH:
 660         case -EPIPE:
 661         case -ECONNREFUSED:
 662                 /* When the server has died, an ICMP port unreachable message
 663                  * prompts ECONNREFUSED. */
 664                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 665         }
 666
 667         return status;
 668 }
 669
 670 /**
 671  * xs_tcp_shutdown - gracefully shut down a TCP socket
 672  * @xprt: transport
 673  *
 674  * Initiates a graceful shutdown of the TCP socket by calling the
 675  * equivalent of shutdown(SHUT_WR);
 676  */
 677 static void xs_tcp_shutdown(struct rpc_xprt *xprt)
 678 {
 679         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 680         struct socket *sock = transport->sock;
 681
 682         if (sock != NULL) {
 683                 kernel_sock_shutdown(sock, SHUT_WR);
 684                 trace_rpc_socket_shutdown(xprt, sock);
 685         }
 686 }
 687
 688 /**
 689  * xs_tcp_send_request - write an RPC request to a TCP socket
 690  * @task: address of RPC task that manages the state of an RPC request
 691  *
 692  * Return values:
 693  *        0:    The request has been sent
 694  *   EAGAIN:    The socket was blocked, please call again later to
 695  *              complete the request
 696  * ENOTCONN:    Caller needs to invoke connect logic then call again
 697  *    other:    Some other error occurred, the request was not sent
 698  *
 699  * XXX: In the case of soft timeouts, should we eventually give up
 700  *      if sendmsg is not able to make progress?
 701  */
 702 static int xs_tcp_send_request(struct rpc_task *task)
 703 {
 704         struct rpc_rqst *req = task->tk_rqstp;
 705         struct rpc_xprt *xprt = req->rq_xprt;
 706         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 707         struct xdr_buf *xdr = &req->rq_snd_buf;
 708         bool zerocopy = true;
 709         int status;
 710
 711         xs_encode_stream_record_marker(&req->rq_snd_buf);
 712
 713         xs_pktdump("packet data:",
 714                                 req->rq_svec->iov_base,
 715                                 req->rq_svec->iov_len);
 716         /* Don't use zero copy if this is a resend. If the RPC call
 717          * completes while the socket holds a reference to the pages,
 718          * then we may end up resending corrupted data.
 719          */
 720         if (task->tk_flags & RPC_TASK_SENT)
 721                 zerocopy = false;
 722
 723         /* Continue transmitting the packet/record. We must be careful
 724          * to cope with writespace callbacks arriving _after_ we have
 725          * called sendmsg(). */
 726         while (1) {
 727                 status = xs_sendpages(transport->sock,
 728                                         NULL, 0, xdr, req->rq_bytes_sent,
 729                                         zerocopy);
 730
 731                 dprintk("RPC:       xs_tcp_send_request(%u) = %d\n",
 732                                 xdr->len - req->rq_bytes_sent, status);
 733
 734                 if (unlikely(status < 0))
 735                         break;
 736
 737                 /* If we've sent the entire packet, immediately
 738                  * reset the count of bytes sent. */
 739                 req->rq_bytes_sent += status;
 740                 req->rq_xmit_bytes_sent += status;
 741                 if (likely(req->rq_bytes_sent >= req->rq_slen)) {
 742                         req->rq_bytes_sent = 0;
 743                         return 0;
 744                 }
 745
 746                 if (status != 0)
 747                         continue;
 748                 status = -EAGAIN;
 749                 break;
 750         }
 751
 752         switch (status) {
 753         case -ENOTSOCK:
 754                 status = -ENOTCONN;
 755                 /* Should we call xs_close() here? */
 756                 break;
 757         case -EAGAIN:
 758                 status = xs_nospace(task);
 759                 break;
 760         default:
 761                 dprintk("RPC:       sendmsg returned unrecognized error %d\n",
 762                         -status);
 763         case -ECONNRESET:
 764                 xs_tcp_shutdown(xprt);
 765         case -ECONNREFUSED:
 766         case -ENOTCONN:
 767         case -EPIPE:
 768                 clear_bit(SOCK_ASYNC_NOSPACE, &transport->sock->flags);
 769         }
 770
 771         return status;
 772 }
 773
 774 /**
 775  * xs_tcp_release_xprt - clean up after a tcp transmission
 776  * @xprt: transport
 777  * @task: rpc task
 778  *
 779  * This cleans up if an error causes us to abort the transmission of a request.
 780  * In this case, the socket may need to be reset in order to avoid confusing
 781  * the server.
 782  */
 783 static void xs_tcp_release_xprt(struct rpc_xprt *xprt, struct rpc_task *task)
 784 {
 785         struct rpc_rqst *req;
 786
 787         if (task != xprt->snd_task)
 788                 return;
 789         if (task == NULL)
 790                 goto out_release;
 791         req = task->tk_rqstp;
 792         if (req == NULL)
 793                 goto out_release;
 794         if (req->rq_bytes_sent == 0)
 795                 goto out_release;
 796         if (req->rq_bytes_sent == req->rq_snd_buf.len)
 797                 goto out_release;
 798         set_bit(XPRT_CLOSE_WAIT, &xprt->state);
 799 out_release:
 800         xprt_release_xprt(xprt, task);
 801 }
 802
 803 static void xs_save_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 804 {
 805         transport->old_data_ready = sk->sk_data_ready;
 806         transport->old_state_change = sk->sk_state_change;
 807         transport->old_write_space = sk->sk_write_space;
 808         transport->old_error_report = sk->sk_error_report;
 809 }
 810
 811 static void xs_restore_old_callbacks(struct sock_xprt *transport, struct sock *sk)
 812 {
 813         sk->sk_data_ready = transport->old_data_ready;
 814         sk->sk_state_change = transport->old_state_change;
 815         sk->sk_write_space = transport->old_write_space;
 816         sk->sk_error_report = transport->old_error_report;
 817 }
 818
 819 /**
 820  * xs_error_report - callback to handle TCP socket state errors
 821  * @sk: socket
 822  *
 823  * Note: we don't call sock_error() since there may be a rpc_task
 824  * using the socket, and so we don't want to clear sk->sk_err.
 825  */
 826 static void xs_error_report(struct sock *sk)
 827 {
 828         struct rpc_xprt *xprt;
 829         int err;
 830
 831         read_lock_bh(&sk->sk_callback_lock);
 832         if (!(xprt = xprt_from_sock(sk)))
 833                 goto out;
 834
 835         err = -sk->sk_err;
 836         if (err == 0)
 837                 goto out;
 838         dprintk("RPC:       xs_error_report client %p, error=%d...\n",
 839                         xprt, -err);
 840         trace_rpc_socket_error(xprt, sk->sk_socket, err);
 841         xprt_wake_pending_tasks(xprt, err);
 842  out:
 843         read_unlock_bh(&sk->sk_callback_lock);
 844 }
 845
 846 static void xs_reset_transport(struct sock_xprt *transport)
 847 {
 848         struct socket *sock = transport->sock;
 849         struct sock *sk = transport->inet;
 850
 851         if (sk == NULL)
 852                 return;
 853
 854         transport->srcport = 0;
 855
 856         write_lock_bh(&sk->sk_callback_lock);
 857         transport->inet = NULL;
 858         transport->sock = NULL;
 859
 860         sk->sk_user_data = NULL;
 861
 862         xs_restore_old_callbacks(transport, sk);
 863         write_unlock_bh(&sk->sk_callback_lock);
 864
 865         sk->sk_no_check = 0;
 866
 867         trace_rpc_socket_close(&transport->xprt, sock);
 868         sock_release(sock);
 869 }
 870
 871 /**
 872  * xs_close - close a socket
 873  * @xprt: transport
 874  *
 875  * This is used when all requests are complete; ie, no DRC state remains
 876  * on the server we want to save.
 877  *
 878  * The caller _must_ be holding XPRT_LOCKED in order to avoid issues with
 879  * xs_reset_transport() zeroing the socket from underneath a writer.
 880  */
 881 static void xs_close(struct rpc_xprt *xprt)
 882 {
 883         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
 884
 885         dprintk("RPC:       xs_close xprt %p\n", xprt);
 886
 887         cancel_delayed_work_sync(&transport->connect_worker);
 888
 889         xs_reset_transport(transport);
 890         xprt->reestablish_timeout = 0;
 891
 892         smp_mb__before_clear_bit();
 893         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
 894         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
 895         clear_bit(XPRT_CLOSING, &xprt->state);
 896         smp_mb__after_clear_bit();
 897         xprt_disconnect_done(xprt);
 898 }
 899
 900 static void xs_tcp_close(struct rpc_xprt *xprt)
 901 {
 902         if (test_and_clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state))
 903                 xs_close(xprt);
 904         else
 905                 xs_tcp_shutdown(xprt);
 906 }
 907
 908 /**
 909  * xs_destroy - prepare to shutdown a transport
 910  * @xprt: doomed transport
 911  *
 912  */
 913 static void xs_destroy(struct rpc_xprt *xprt)
 914 {
 915         dprintk("RPC:       xs_destroy xprt %p\n", xprt);
 916
 917         xs_close(xprt);
 918         xs_free_peer_addresses(xprt);
 919         xprt_free(xprt);
 920         module_put(THIS_MODULE);
 921 }
 922
 923 static int xs_local_copy_to_xdr(struct xdr_buf *xdr, struct sk_buff *skb)
 924 {
 925         struct xdr_skb_reader desc = {
 926                 .skb            = skb,
 927                 .offset         = sizeof(rpc_fraghdr),
 928                 .count          = skb->len - sizeof(rpc_fraghdr),
 929         };
 930
 931         if (xdr_partial_copy_from_skb(xdr, 0, &desc, xdr_skb_read_bits) < 0)
 932                 return -1;
 933         if (desc.count)
 934                 return -1;
 935         return 0;
 936 }
 937
 938 /**
 939  * xs_local_data_ready - "data ready" callback for AF_LOCAL sockets
 940  * @sk: socket with data to read
 941  * @len: how much data to read
 942  *
 943  * Currently this assumes we can read the whole reply in a single gulp.
 944  */
 945 static void xs_local_data_ready(struct sock *sk, int len)
 946 {
 947         struct rpc_task *task;
 948         struct rpc_xprt *xprt;
 949         struct rpc_rqst *rovr;
 950         struct sk_buff *skb;
 951         int err, repsize, copied;
 952         u32 _xid;
 953         __be32 *xp;
 954
 955         read_lock_bh(&sk->sk_callback_lock);
 956         dprintk("RPC:       %s...\n", __func__);
 957         xprt = xprt_from_sock(sk);
 958         if (xprt == NULL)
 959                 goto out;
 960
 961         skb = skb_recv_datagram(sk, 0, 1, &err);
 962         if (skb == NULL)
 963                 goto out;
 964
 965         repsize = skb->len - sizeof(rpc_fraghdr);
 966         if (repsize < 4) {
 967                 dprintk("RPC:       impossible RPC reply size %d\n", repsize);
 968                 goto dropit;
 969         }
 970
 971         /* Copy the XID from the skb... */
 972         xp = skb_header_pointer(skb, sizeof(rpc_fraghdr), sizeof(_xid), &_xid);
 973         if (xp == NULL)
 974                 goto dropit;
 975
 976         /* Look up and lock the request corresponding to the given XID */
 977         spin_lock(&xprt->transport_lock);
 978         rovr = xprt_lookup_rqst(xprt, *xp);
 979         if (!rovr)
 980                 goto out_unlock;
 981         task = rovr->rq_task;
 982
 983         copied = rovr->rq_private_buf.buflen;
 984         if (copied > repsize)
 985                 copied = repsize;
 986
 987         if (xs_local_copy_to_xdr(&rovr->rq_private_buf, skb)) {
 988                 dprintk("RPC:       sk_buff copy failed\n");
 989                 goto out_unlock;
 990         }
 991
 992         xprt_complete_rqst(task, copied);
 993
 994  out_unlock:
 995         spin_unlock(&xprt->transport_lock);
 996  dropit:
 997         skb_free_datagram(sk, skb);
 998  out:
 999         read_unlock_bh(&sk->sk_callback_lock);
1000 }
1001
1002 /**
1003  * xs_udp_data_ready - "data ready" callback for UDP sockets
1004  * @sk: socket with data to read
1005  * @len: how much data to read
1006  *
1007  */
1008 static void xs_udp_data_ready(struct sock *sk, int len)
1009 {
1010         struct rpc_task *task;
1011         struct rpc_xprt *xprt;
1012         struct rpc_rqst *rovr;
1013         struct sk_buff *skb;
1014         int err, repsize, copied;
1015         u32 _xid;
1016         __be32 *xp;
1017
1018         read_lock_bh(&sk->sk_callback_lock);
1019         dprintk("RPC:       xs_udp_data_ready...\n");
1020         if (!(xprt = xprt_from_sock(sk)))
1021                 goto out;
1022
1023         if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
1024                 goto out;
1025
1026         repsize = skb->len - sizeof(struct udphdr);
1027         if (repsize < 4) {
1028                 dprintk("RPC:       impossible RPC reply size %d!\n", repsize);
1029                 goto dropit;
1030         }
1031
1032         /* Copy the XID from the skb... */
1033         xp = skb_header_pointer(skb, sizeof(struct udphdr),
1034                                 sizeof(_xid), &_xid);
1035         if (xp == NULL)
1036                 goto dropit;
1037
1038         /* Look up and lock the request corresponding to the given XID */
1039         spin_lock(&xprt->transport_lock);
1040         rovr = xprt_lookup_rqst(xprt, *xp);
1041         if (!rovr)
1042                 goto out_unlock;
1043         task = rovr->rq_task;
1044
1045         if ((copied = rovr->rq_private_buf.buflen) > repsize)
1046                 copied = repsize;
1047
1048         /* Suck it into the iovec, verify checksum if not done by hw. */
1049         if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb)) {
1050                 UDPX_INC_STATS_BH(sk, UDP_MIB_INERRORS);
1051                 goto out_unlock;
1052         }
1053
1054         UDPX_INC_STATS_BH(sk, UDP_MIB_INDATAGRAMS);
1055
1056         xprt_adjust_cwnd(xprt, task, copied);
1057         xprt_complete_rqst(task, copied);
1058
1059  out_unlock:
1060         spin_unlock(&xprt->transport_lock);
1061  dropit:
1062         skb_free_datagram(sk, skb);
1063  out:
1064         read_unlock_bh(&sk->sk_callback_lock);
1065 }
1066
1067 /*
1068  * Helper function to force a TCP close if the server is sending
1069  * junk and/or it has put us in CLOSE_WAIT
1070  */
1071 static void xs_tcp_force_close(struct rpc_xprt *xprt)
1072 {
1073         set_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1074         xprt_force_disconnect(xprt);
1075 }
1076
1077 static inline void xs_tcp_read_fraghdr(struct rpc_xprt *xprt, struct xdr_skb_reader *desc)
1078 {
1079         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1080         size_t len, used;
1081         char *p;
1082
1083         p = ((char *) &transport->tcp_fraghdr) + transport->tcp_offset;
1084         len = sizeof(transport->tcp_fraghdr) - transport->tcp_offset;
1085         used = xdr_skb_read_bits(desc, p, len);
1086         transport->tcp_offset += used;
1087         if (used != len)
1088                 return;
1089
1090         transport->tcp_reclen = ntohl(transport->tcp_fraghdr);
1091         if (transport->tcp_reclen & RPC_LAST_STREAM_FRAGMENT)
1092                 transport->tcp_flags |= TCP_RCV_LAST_FRAG;
1093         else
1094                 transport->tcp_flags &= ~TCP_RCV_LAST_FRAG;
1095         transport->tcp_reclen &= RPC_FRAGMENT_SIZE_MASK;
1096
1097         transport->tcp_flags &= ~TCP_RCV_COPY_FRAGHDR;
1098         transport->tcp_offset = 0;
1099
1100         /* Sanity check of the record length */
1101         if (unlikely(transport->tcp_reclen < 8)) {
1102                 dprintk("RPC:       invalid TCP record fragment length\n");
1103                 xs_tcp_force_close(xprt);
1104                 return;
1105         }
1106         dprintk("RPC:       reading TCP record fragment of length %d\n",
1107                         transport->tcp_reclen);
1108 }
1109
1110 static void xs_tcp_check_fraghdr(struct sock_xprt *transport)
1111 {
1112         if (transport->tcp_offset == transport->tcp_reclen) {
1113                 transport->tcp_flags |= TCP_RCV_COPY_FRAGHDR;
1114                 transport->tcp_offset = 0;
1115                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG) {
1116                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1117                         transport->tcp_flags |= TCP_RCV_COPY_XID;
1118                         transport->tcp_copied = 0;
1119                 }
1120         }
1121 }
1122
1123 static inline void xs_tcp_read_xid(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1124 {
1125         size_t len, used;
1126         char *p;
1127
1128         len = sizeof(transport->tcp_xid) - transport->tcp_offset;
1129         dprintk("RPC:       reading XID (%Zu bytes)\n", len);
1130         p = ((char *) &transport->tcp_xid) + transport->tcp_offset;
1131         used = xdr_skb_read_bits(desc, p, len);
1132         transport->tcp_offset += used;
1133         if (used != len)
1134                 return;
1135         transport->tcp_flags &= ~TCP_RCV_COPY_XID;
1136         transport->tcp_flags |= TCP_RCV_READ_CALLDIR;
1137         transport->tcp_copied = 4;
1138         dprintk("RPC:       reading %s XID %08x\n",
1139                         (transport->tcp_flags & TCP_RPC_REPLY) ? "reply for"
1140                                                               : "request with",
1141                         ntohl(transport->tcp_xid));
1142         xs_tcp_check_fraghdr(transport);
1143 }
1144
1145 static inline void xs_tcp_read_calldir(struct sock_xprt *transport,
1146                                        struct xdr_skb_reader *desc)
1147 {
1148         size_t len, used;
1149         u32 offset;
1150         char *p;
1151
1152         /*
1153          * We want transport->tcp_offset to be 8 at the end of this routine
1154          * (4 bytes for the xid and 4 bytes for the call/reply flag).
1155          * When this function is called for the first time,
1156          * transport->tcp_offset is 4 (after having already read the xid).
1157          */
1158         offset = transport->tcp_offset - sizeof(transport->tcp_xid);
1159         len = sizeof(transport->tcp_calldir) - offset;
1160         dprintk("RPC:       reading CALL/REPLY flag (%Zu bytes)\n", len);
1161         p = ((char *) &transport->tcp_calldir) + offset;
1162         used = xdr_skb_read_bits(desc, p, len);
1163         transport->tcp_offset += used;
1164         if (used != len)
1165                 return;
1166         transport->tcp_flags &= ~TCP_RCV_READ_CALLDIR;
1167         /*
1168          * We don't yet have the XDR buffer, so we will write the calldir
1169          * out after we get the buffer from the 'struct rpc_rqst'
1170          */
1171         switch (ntohl(transport->tcp_calldir)) {
1172         case RPC_REPLY:
1173                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1174                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1175                 transport->tcp_flags |= TCP_RPC_REPLY;
1176                 break;
1177         case RPC_CALL:
1178                 transport->tcp_flags |= TCP_RCV_COPY_CALLDIR;
1179                 transport->tcp_flags |= TCP_RCV_COPY_DATA;
1180                 transport->tcp_flags &= ~TCP_RPC_REPLY;
1181                 break;
1182         default:
1183                 dprintk("RPC:       invalid request message type\n");
1184                 xs_tcp_force_close(&transport->xprt);
1185         }
1186         xs_tcp_check_fraghdr(transport);
1187 }
1188
1189 static inline void xs_tcp_read_common(struct rpc_xprt *xprt,
1190                                      struct xdr_skb_reader *desc,
1191                                      struct rpc_rqst *req)
1192 {
1193         struct sock_xprt *transport =
1194                                 container_of(xprt, struct sock_xprt, xprt);
1195         struct xdr_buf *rcvbuf;
1196         size_t len;
1197         ssize_t r;
1198
1199         rcvbuf = &req->rq_private_buf;
1200
1201         if (transport->tcp_flags & TCP_RCV_COPY_CALLDIR) {
1202                 /*
1203                  * Save the RPC direction in the XDR buffer
1204                  */
1205                 memcpy(rcvbuf->head[0].iov_base + transport->tcp_copied,
1206                         &transport->tcp_calldir,
1207                         sizeof(transport->tcp_calldir));
1208                 transport->tcp_copied += sizeof(transport->tcp_calldir);
1209                 transport->tcp_flags &= ~TCP_RCV_COPY_CALLDIR;
1210         }
1211
1212         len = desc->count;
1213         if (len > transport->tcp_reclen - transport->tcp_offset) {
1214                 struct xdr_skb_reader my_desc;
1215
1216                 len = transport->tcp_reclen - transport->tcp_offset;
1217                 memcpy(&my_desc, desc, sizeof(my_desc));
1218                 my_desc.count = len;
1219                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1220                                           &my_desc, xdr_skb_read_bits);
1221                 desc->count -= r;
1222                 desc->offset += r;
1223         } else
1224                 r = xdr_partial_copy_from_skb(rcvbuf, transport->tcp_copied,
1225                                           desc, xdr_skb_read_bits);
1226
1227         if (r > 0) {
1228                 transport->tcp_copied += r;
1229                 transport->tcp_offset += r;
1230         }
1231         if (r != len) {
1232                 /* Error when copying to the receive buffer,
1233                  * usually because we weren't able to allocate
1234                  * additional buffer pages. All we can do now
1235                  * is turn off TCP_RCV_COPY_DATA, so the request
1236                  * will not receive any additional updates,
1237                  * and time out.
1238                  * Any remaining data from this record will
1239                  * be discarded.
1240                  */
1241                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1242                 dprintk("RPC:       XID %08x truncated request\n",
1243                                 ntohl(transport->tcp_xid));
1244                 dprintk("RPC:       xprt = %p, tcp_copied = %lu, "
1245                                 "tcp_offset = %u, tcp_reclen = %u\n",
1246                                 xprt, transport->tcp_copied,
1247                                 transport->tcp_offset, transport->tcp_reclen);
1248                 return;
1249         }
1250
1251         dprintk("RPC:       XID %08x read %Zd bytes\n",
1252                         ntohl(transport->tcp_xid), r);
1253         dprintk("RPC:       xprt = %p, tcp_copied = %lu, tcp_offset = %u, "
1254                         "tcp_reclen = %u\n", xprt, transport->tcp_copied,
1255                         transport->tcp_offset, transport->tcp_reclen);
1256
1257         if (transport->tcp_copied == req->rq_private_buf.buflen)
1258                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1259         else if (transport->tcp_offset == transport->tcp_reclen) {
1260                 if (transport->tcp_flags & TCP_RCV_LAST_FRAG)
1261                         transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1262         }
1263 }
1264
1265 /*
1266  * Finds the request corresponding to the RPC xid and invokes the common
1267  * tcp read code to read the data.
1268  */
1269 static inline int xs_tcp_read_reply(struct rpc_xprt *xprt,
1270                                     struct xdr_skb_reader *desc)
1271 {
1272         struct sock_xprt *transport =
1273                                 container_of(xprt, struct sock_xprt, xprt);
1274         struct rpc_rqst *req;
1275
1276         dprintk("RPC:       read reply XID %08x\n", ntohl(transport->tcp_xid));
1277
1278         /* Find and lock the request corresponding to this xid */
1279         spin_lock(&xprt->transport_lock);
1280         req = xprt_lookup_rqst(xprt, transport->tcp_xid);
1281         if (!req) {
1282                 dprintk("RPC:       XID %08x request not found!\n",
1283                                 ntohl(transport->tcp_xid));
1284                 spin_unlock(&xprt->transport_lock);
1285                 return -1;
1286         }
1287
1288         xs_tcp_read_common(xprt, desc, req);
1289
1290         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA))
1291                 xprt_complete_rqst(req->rq_task, transport->tcp_copied);
1292
1293         spin_unlock(&xprt->transport_lock);
1294         return 0;
1295 }
1296
1297 #if defined(CONFIG_SUNRPC_BACKCHANNEL)
1298 /*
1299  * Obtains an rpc_rqst previously allocated and invokes the common
1300  * tcp read code to read the data.  The result is placed in the callback
1301  * queue.
1302  * If we're unable to obtain the rpc_rqst we schedule the closing of the
1303  * connection and return -1.
1304  */
1305 static inline int xs_tcp_read_callback(struct rpc_xprt *xprt,
1306                                        struct xdr_skb_reader *desc)
1307 {
1308         struct sock_xprt *transport =
1309                                 container_of(xprt, struct sock_xprt, xprt);
1310         struct rpc_rqst *req;
1311
1312         req = xprt_alloc_bc_request(xprt);
1313         if (req == NULL) {
1314                 printk(KERN_WARNING "Callback slot table overflowed\n");
1315                 xprt_force_disconnect(xprt);
1316                 return -1;
1317         }
1318
1319         req->rq_xid = transport->tcp_xid;
1320         dprintk("RPC:       read callback  XID %08x\n", ntohl(req->rq_xid));
1321         xs_tcp_read_common(xprt, desc, req);
1322
1323         if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) {
1324                 struct svc_serv *bc_serv = xprt->bc_serv;
1325
1326                 /*
1327                  * Add callback request to callback list.  The callback
1328                  * service sleeps on the sv_cb_waitq waiting for new
1329                  * requests.  Wake it up after adding enqueing the
1330                  * request.
1331                  */
1332                 dprintk("RPC:       add callback request to list\n");
1333                 spin_lock(&bc_serv->sv_cb_lock);
1334                 list_add(&req->rq_bc_list, &bc_serv->sv_cb_list);
1335                 spin_unlock(&bc_serv->sv_cb_lock);
1336                 wake_up(&bc_serv->sv_cb_waitq);
1337         }
1338
1339         req->rq_private_buf.len = transport->tcp_copied;
1340
1341         return 0;
1342 }
1343
1344 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1345                                         struct xdr_skb_reader *desc)
1346 {
1347         struct sock_xprt *transport =
1348                                 container_of(xprt, struct sock_xprt, xprt);
1349
1350         return (transport->tcp_flags & TCP_RPC_REPLY) ?
1351                 xs_tcp_read_reply(xprt, desc) :
1352                 xs_tcp_read_callback(xprt, desc);
1353 }
1354 #else
1355 static inline int _xs_tcp_read_data(struct rpc_xprt *xprt,
1356                                         struct xdr_skb_reader *desc)
1357 {
1358         return xs_tcp_read_reply(xprt, desc);
1359 }
1360 #endif /* CONFIG_SUNRPC_BACKCHANNEL */
1361
1362 /*
1363  * Read data off the transport.  This can be either an RPC_CALL or an
1364  * RPC_REPLY.  Relay the processing to helper functions.
1365  */
1366 static void xs_tcp_read_data(struct rpc_xprt *xprt,
1367                                     struct xdr_skb_reader *desc)
1368 {
1369         struct sock_xprt *transport =
1370                                 container_of(xprt, struct sock_xprt, xprt);
1371
1372         if (_xs_tcp_read_data(xprt, desc) == 0)
1373                 xs_tcp_check_fraghdr(transport);
1374         else {
1375                 /*
1376                  * The transport_lock protects the request handling.
1377                  * There's no need to hold it to update the tcp_flags.
1378                  */
1379                 transport->tcp_flags &= ~TCP_RCV_COPY_DATA;
1380         }
1381 }
1382
1383 static inline void xs_tcp_read_discard(struct sock_xprt *transport, struct xdr_skb_reader *desc)
1384 {
1385         size_t len;
1386
1387         len = transport->tcp_reclen - transport->tcp_offset;
1388         if (len > desc->count)
1389                 len = desc->count;
1390         desc->count -= len;
1391         desc->offset += len;
1392         transport->tcp_offset += len;
1393         dprintk("RPC:       discarded %Zu bytes\n", len);
1394         xs_tcp_check_fraghdr(transport);
1395 }
1396
1397 static int xs_tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb, unsigned int offset, size_t len)
1398 {
1399         struct rpc_xprt *xprt = rd_desc->arg.data;
1400         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1401         struct xdr_skb_reader desc = {
1402                 .skb    = skb,
1403                 .offset = offset,
1404                 .count  = len,
1405         };
1406
1407         dprintk("RPC:       xs_tcp_data_recv started\n");
1408         do {
1409                 /* Read in a new fragment marker if necessary */
1410                 /* Can we ever really expect to get completely empty fragments? */
1411                 if (transport->tcp_flags & TCP_RCV_COPY_FRAGHDR) {
1412                         xs_tcp_read_fraghdr(xprt, &desc);
1413                         continue;
1414                 }
1415                 /* Read in the xid if necessary */
1416                 if (transport->tcp_flags & TCP_RCV_COPY_XID) {
1417                         xs_tcp_read_xid(transport, &desc);
1418                         continue;
1419                 }
1420                 /* Read in the call/reply flag */
1421                 if (transport->tcp_flags & TCP_RCV_READ_CALLDIR) {
1422                         xs_tcp_read_calldir(transport, &desc);
1423                         continue;
1424                 }
1425                 /* Read in the request data */
1426                 if (transport->tcp_flags & TCP_RCV_COPY_DATA) {
1427                         xs_tcp_read_data(xprt, &desc);
1428                         continue;
1429                 }
1430                 /* Skip over any trailing bytes on short reads */
1431                 xs_tcp_read_discard(transport, &desc);
1432         } while (desc.count);
1433         dprintk("RPC:       xs_tcp_data_recv done\n");
1434         return len - desc.count;
1435 }
1436
1437 /**
1438  * xs_tcp_data_ready - "data ready" callback for TCP sockets
1439  * @sk: socket with data to read
1440  * @bytes: how much data to read
1441  *
1442  */
1443 static void xs_tcp_data_ready(struct sock *sk, int bytes)
1444 {
1445         struct rpc_xprt *xprt;
1446         read_descriptor_t rd_desc;
1447         int read;
1448
1449         dprintk("RPC:       xs_tcp_data_ready...\n");
1450
1451         read_lock_bh(&sk->sk_callback_lock);
1452         if (!(xprt = xprt_from_sock(sk)))
1453                 goto out;
1454         /* Any data means we had a useful conversation, so
1455          * the we don't need to delay the next reconnect
1456          */
1457         if (xprt->reestablish_timeout)
1458                 xprt->reestablish_timeout = 0;
1459
1460         /* We use rd_desc to pass struct xprt to xs_tcp_data_recv */
1461         rd_desc.arg.data = xprt;
1462         do {
1463                 rd_desc.count = 65536;
1464                 read = tcp_read_sock(sk, &rd_desc, xs_tcp_data_recv);
1465         } while (read > 0);
1466 out:
1467         read_unlock_bh(&sk->sk_callback_lock);
1468 }
1469
1470 /*
1471  * Do the equivalent of linger/linger2 handling for dealing with
1472  * broken servers that don't close the socket in a timely
1473  * fashion
1474  */
1475 static void xs_tcp_schedule_linger_timeout(struct rpc_xprt *xprt,
1476                 unsigned long timeout)
1477 {
1478         struct sock_xprt *transport;
1479
1480         if (xprt_test_and_set_connecting(xprt))
1481                 return;
1482         set_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1483         transport = container_of(xprt, struct sock_xprt, xprt);
1484         queue_delayed_work(rpciod_workqueue, &transport->connect_worker,
1485                            timeout);
1486 }
1487
1488 static void xs_tcp_cancel_linger_timeout(struct rpc_xprt *xprt)
1489 {
1490         struct sock_xprt *transport;
1491
1492         transport = container_of(xprt, struct sock_xprt, xprt);
1493
1494         if (!test_bit(XPRT_CONNECTION_ABORT, &xprt->state) ||
1495             !cancel_delayed_work(&transport->connect_worker))
1496                 return;
1497         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1498         xprt_clear_connecting(xprt);
1499 }
1500
1501 static void xs_sock_reset_connection_flags(struct rpc_xprt *xprt)
1502 {
1503         smp_mb__before_clear_bit();
1504         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1505         clear_bit(XPRT_CONNECTION_CLOSE, &xprt->state);
1506         clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1507         clear_bit(XPRT_CLOSING, &xprt->state);
1508         smp_mb__after_clear_bit();
1509 }
1510
1511 static void xs_sock_mark_closed(struct rpc_xprt *xprt)
1512 {
1513         xs_sock_reset_connection_flags(xprt);
1514         /* Mark transport as closed and wake up all pending tasks */
1515         xprt_disconnect_done(xprt);
1516 }
1517
1518 /**
1519  * xs_tcp_state_change - callback to handle TCP socket state changes
1520  * @sk: socket whose state has changed
1521  *
1522  */
1523 static void xs_tcp_state_change(struct sock *sk)
1524 {
1525         struct rpc_xprt *xprt;
1526
1527         read_lock_bh(&sk->sk_callback_lock);
1528         if (!(xprt = xprt_from_sock(sk)))
1529                 goto out;
1530         dprintk("RPC:       xs_tcp_state_change client %p...\n", xprt);
1531         dprintk("RPC:       state %x conn %d dead %d zapped %d sk_shutdown %d\n",
1532                         sk->sk_state, xprt_connected(xprt),
1533                         sock_flag(sk, SOCK_DEAD),
1534                         sock_flag(sk, SOCK_ZAPPED),
1535                         sk->sk_shutdown);
1536
1537         trace_rpc_socket_state_change(xprt, sk->sk_socket);
1538         switch (sk->sk_state) {
1539         case TCP_ESTABLISHED:
1540                 spin_lock(&xprt->transport_lock);
1541                 if (!xprt_test_and_set_connected(xprt)) {
1542                         struct sock_xprt *transport = container_of(xprt,
1543                                         struct sock_xprt, xprt);
1544
1545                         /* Reset TCP record info */
1546                         transport->tcp_offset = 0;
1547                         transport->tcp_reclen = 0;
1548                         transport->tcp_copied = 0;
1549                         transport->tcp_flags =
1550                                 TCP_RCV_COPY_FRAGHDR | TCP_RCV_COPY_XID;
1551                         xprt->connect_cookie++;
1552
1553                         xprt_wake_pending_tasks(xprt, -EAGAIN);
1554                 }
1555                 spin_unlock(&xprt->transport_lock);
1556                 break;
1557         case TCP_FIN_WAIT1:
1558                 /* The client initiated a shutdown of the socket */
1559                 xprt->connect_cookie++;
1560                 xprt->reestablish_timeout = 0;
1561                 set_bit(XPRT_CLOSING, &xprt->state);
1562                 smp_mb__before_clear_bit();
1563                 clear_bit(XPRT_CONNECTED, &xprt->state);
1564                 clear_bit(XPRT_CLOSE_WAIT, &xprt->state);
1565                 smp_mb__after_clear_bit();
1566                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1567                 break;
1568         case TCP_CLOSE_WAIT:
1569                 /* The server initiated a shutdown of the socket */
1570                 xprt->connect_cookie++;
1571                 clear_bit(XPRT_CONNECTED, &xprt->state);
1572                 xs_tcp_force_close(xprt);
1573         case TCP_CLOSING:
1574                 /*
1575                  * If the server closed down the connection, make sure that
1576                  * we back off before reconnecting
1577                  */
1578                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
1579                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
1580                 break;
1581         case TCP_LAST_ACK:
1582                 set_bit(XPRT_CLOSING, &xprt->state);
1583                 xs_tcp_schedule_linger_timeout(xprt, xs_tcp_fin_timeout);
1584                 smp_mb__before_clear_bit();
1585                 clear_bit(XPRT_CONNECTED, &xprt->state);
1586                 smp_mb__after_clear_bit();
1587                 break;
1588         case TCP_CLOSE:
1589                 xs_tcp_cancel_linger_timeout(xprt);
1590                 xs_sock_mark_closed(xprt);
1591         }
1592  out:
1593         read_unlock_bh(&sk->sk_callback_lock);
1594 }
1595
1596 static void xs_write_space(struct sock *sk)
1597 {
1598         struct socket *sock;
1599         struct rpc_xprt *xprt;
1600
1601         if (unlikely(!(sock = sk->sk_socket)))
1602                 return;
1603         clear_bit(SOCK_NOSPACE, &sock->flags);
1604
1605         if (unlikely(!(xprt = xprt_from_sock(sk))))
1606                 return;
1607         if (test_and_clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags) == 0)
1608                 return;
1609
1610         xprt_write_space(xprt);
1611 }
1612
1613 /**
1614  * xs_udp_write_space - callback invoked when socket buffer space
1615  *                             becomes available
1616  * @sk: socket whose state has changed
1617  *
1618  * Called when more output buffer space is available for this socket.
1619  * We try not to wake our writers until they can make "significant"
1620  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1621  * with a bunch of small requests.
1622  */
1623 static void xs_udp_write_space(struct sock *sk)
1624 {
1625         read_lock_bh(&sk->sk_callback_lock);
1626
1627         /* from net/core/sock.c:sock_def_write_space */
1628         if (sock_writeable(sk))
1629                 xs_write_space(sk);
1630
1631         read_unlock_bh(&sk->sk_callback_lock);
1632 }
1633
1634 /**
1635  * xs_tcp_write_space - callback invoked when socket buffer space
1636  *                             becomes available
1637  * @sk: socket whose state has changed
1638  *
1639  * Called when more output buffer space is available for this socket.
1640  * We try not to wake our writers until they can make "significant"
1641  * progress, otherwise we'll waste resources thrashing kernel_sendmsg
1642  * with a bunch of small requests.
1643  */
1644 static void xs_tcp_write_space(struct sock *sk)
1645 {
1646         read_lock_bh(&sk->sk_callback_lock);
1647
1648         /* from net/core/stream.c:sk_stream_write_space */
1649         if (sk_stream_is_writeable(sk))
1650                 xs_write_space(sk);
1651
1652         read_unlock_bh(&sk->sk_callback_lock);
1653 }
1654
1655 static void xs_udp_do_set_buffer_size(struct rpc_xprt *xprt)
1656 {
1657         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1658         struct sock *sk = transport->inet;
1659
1660         if (transport->rcvsize) {
1661                 sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
1662                 sk->sk_rcvbuf = transport->rcvsize * xprt->max_reqs * 2;
1663         }
1664         if (transport->sndsize) {
1665                 sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
1666                 sk->sk_sndbuf = transport->sndsize * xprt->max_reqs * 2;
1667                 sk->sk_write_space(sk);
1668         }
1669 }
1670
1671 /**
1672  * xs_udp_set_buffer_size - set send and receive limits
1673  * @xprt: generic transport
1674  * @sndsize: requested size of send buffer, in bytes
1675  * @rcvsize: requested size of receive buffer, in bytes
1676  *
1677  * Set socket send and receive buffer size limits.
1678  */
1679 static void xs_udp_set_buffer_size(struct rpc_xprt *xprt, size_t sndsize, size_t rcvsize)
1680 {
1681         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1682
1683         transport->sndsize = 0;
1684         if (sndsize)
1685                 transport->sndsize = sndsize + 1024;
1686         transport->rcvsize = 0;
1687         if (rcvsize)
1688                 transport->rcvsize = rcvsize + 1024;
1689
1690         xs_udp_do_set_buffer_size(xprt);
1691 }
1692
1693 /**
1694  * xs_udp_timer - called when a retransmit timeout occurs on a UDP transport
1695  * @task: task that timed out
1696  *
1697  * Adjust the congestion window after a retransmit timeout has occurred.
1698  */
1699 static void xs_udp_timer(struct rpc_xprt *xprt, struct rpc_task *task)
1700 {
1701         xprt_adjust_cwnd(xprt, task, -ETIMEDOUT);
1702 }
1703
1704 static unsigned short xs_get_random_port(void)
1705 {
1706         unsigned short range = xprt_max_resvport - xprt_min_resvport;
1707         unsigned short rand = (unsigned short) prandom_u32() % range;
1708         return rand + xprt_min_resvport;
1709 }
1710
1711 /**
1712  * xs_set_port - reset the port number in the remote endpoint address
1713  * @xprt: generic transport
1714  * @port: new port number
1715  *
1716  */
1717 static void xs_set_port(struct rpc_xprt *xprt, unsigned short port)
1718 {
1719         dprintk("RPC:       setting port for xprt %p to %u\n", xprt, port);
1720
1721         rpc_set_port(xs_addr(xprt), port);
1722         xs_update_peer_port(xprt);
1723 }
1724
1725 static unsigned short xs_get_srcport(struct sock_xprt *transport)
1726 {
1727         unsigned short port = transport->srcport;
1728
1729         if (port == 0 && transport->xprt.resvport)
1730                 port = xs_get_random_port();
1731         return port;
1732 }
1733
1734 static unsigned short xs_next_srcport(struct sock_xprt *transport, unsigned short port)
1735 {
1736         if (transport->srcport != 0)
1737                 transport->srcport = 0;
1738         if (!transport->xprt.resvport)
1739                 return 0;
1740         if (port <= xprt_min_resvport || port > xprt_max_resvport)
1741                 return xprt_max_resvport;
1742         return --port;
1743 }
1744 static int xs_bind(struct sock_xprt *transport, struct socket *sock)
1745 {
1746         struct sockaddr_storage myaddr;
1747         int err, nloop = 0;
1748         unsigned short port = xs_get_srcport(transport);
1749         unsigned short last;
1750
1751         memcpy(&myaddr, &transport->srcaddr, transport->xprt.addrlen);
1752         do {
1753                 rpc_set_port((struct sockaddr *)&myaddr, port);
1754                 err = kernel_bind(sock, (struct sockaddr *)&myaddr,
1755                                 transport->xprt.addrlen);
1756                 if (port == 0)
1757                         break;
1758                 if (err == 0) {
1759                         transport->srcport = port;
1760                         break;
1761                 }
1762                 last = port;
1763                 port = xs_next_srcport(transport, port);
1764                 if (port > last)
1765                         nloop++;
1766         } while (err == -EADDRINUSE && nloop != 2);
1767
1768         if (myaddr.ss_family == AF_INET)
1769                 dprintk("RPC:       %s %pI4:%u: %s (%d)\n", __func__,
1770                                 &((struct sockaddr_in *)&myaddr)->sin_addr,
1771                                 port, err ? "failed" : "ok", err);
1772         else
1773                 dprintk("RPC:       %s %pI6:%u: %s (%d)\n", __func__,
1774                                 &((struct sockaddr_in6 *)&myaddr)->sin6_addr,
1775                                 port, err ? "failed" : "ok", err);
1776         return err;
1777 }
1778
1779 /*
1780  * We don't support autobind on AF_LOCAL sockets
1781  */
1782 static void xs_local_rpcbind(struct rpc_task *task)
1783 {
1784         rcu_read_lock();
1785         xprt_set_bound(rcu_dereference(task->tk_client->cl_xprt));
1786         rcu_read_unlock();
1787 }
1788
1789 static void xs_local_set_port(struct rpc_xprt *xprt, unsigned short port)
1790 {
1791 }
1792
1793 #ifdef CONFIG_DEBUG_LOCK_ALLOC
1794 static struct lock_class_key xs_key[2];
1795 static struct lock_class_key xs_slock_key[2];
1796
1797 static inline void xs_reclassify_socketu(struct socket *sock)
1798 {
1799         struct sock *sk = sock->sk;
1800
1801         sock_lock_init_class_and_name(sk, "slock-AF_LOCAL-RPC",
1802                 &xs_slock_key[1], "sk_lock-AF_LOCAL-RPC", &xs_key[1]);
1803 }
1804
1805 static inline void xs_reclassify_socket4(struct socket *sock)
1806 {
1807         struct sock *sk = sock->sk;
1808
1809         sock_lock_init_class_and_name(sk, "slock-AF_INET-RPC",
1810                 &xs_slock_key[0], "sk_lock-AF_INET-RPC", &xs_key[0]);
1811 }
1812
1813 static inline void xs_reclassify_socket6(struct socket *sock)
1814 {
1815         struct sock *sk = sock->sk;
1816
1817         sock_lock_init_class_and_name(sk, "slock-AF_INET6-RPC",
1818                 &xs_slock_key[1], "sk_lock-AF_INET6-RPC", &xs_key[1]);
1819 }
1820
1821 static inline void xs_reclassify_socket(int family, struct socket *sock)
1822 {
1823         WARN_ON_ONCE(sock_owned_by_user(sock->sk));
1824         if (sock_owned_by_user(sock->sk))
1825                 return;
1826
1827         switch (family) {
1828         case AF_LOCAL:
1829                 xs_reclassify_socketu(sock);
1830                 break;
1831         case AF_INET:
1832                 xs_reclassify_socket4(sock);
1833                 break;
1834         case AF_INET6:
1835                 xs_reclassify_socket6(sock);
1836                 break;
1837         }
1838 }
1839 #else
1840 static inline void xs_reclassify_socketu(struct socket *sock)
1841 {
1842 }
1843
1844 static inline void xs_reclassify_socket4(struct socket *sock)
1845 {
1846 }
1847
1848 static inline void xs_reclassify_socket6(struct socket *sock)
1849 {
1850 }
1851
1852 static inline void xs_reclassify_socket(int family, struct socket *sock)
1853 {
1854 }
1855 #endif
1856
1857 static void xs_dummy_setup_socket(struct work_struct *work)
1858 {
1859 }
1860
1861 static struct socket *xs_create_sock(struct rpc_xprt *xprt,
1862                 struct sock_xprt *transport, int family, int type, int protocol)
1863 {
1864         struct socket *sock;
1865         int err;
1866
1867         err = __sock_create(xprt->xprt_net, family, type, protocol, &sock, 1);
1868         if (err < 0) {
1869                 dprintk("RPC:       can't create %d transport socket (%d).\n",
1870                                 protocol, -err);
1871                 goto out;
1872         }
1873         xs_reclassify_socket(family, sock);
1874
1875         err = xs_bind(transport, sock);
1876         if (err) {
1877                 sock_release(sock);
1878                 goto out;
1879         }
1880
1881         return sock;
1882 out:
1883         return ERR_PTR(err);
1884 }
1885
1886 static int xs_local_finish_connecting(struct rpc_xprt *xprt,
1887                                       struct socket *sock)
1888 {
1889         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
1890                                                                         xprt);
1891
1892         if (!transport->inet) {
1893                 struct sock *sk = sock->sk;
1894
1895                 write_lock_bh(&sk->sk_callback_lock);
1896
1897                 xs_save_old_callbacks(transport, sk);
1898
1899                 sk->sk_user_data = xprt;
1900                 sk->sk_data_ready = xs_local_data_ready;
1901                 sk->sk_write_space = xs_udp_write_space;
1902                 sk->sk_error_report = xs_error_report;
1903                 sk->sk_allocation = GFP_ATOMIC;
1904
1905                 xprt_clear_connected(xprt);
1906
1907                 /* Reset to new socket */
1908                 transport->sock = sock;
1909                 transport->inet = sk;
1910
1911                 write_unlock_bh(&sk->sk_callback_lock);
1912         }
1913
1914         /* Tell the socket layer to start connecting... */
1915         xprt->stat.connect_count++;
1916         xprt->stat.connect_start = jiffies;
1917         return kernel_connect(sock, xs_addr(xprt), xprt->addrlen, 0);
1918 }
1919
1920 /**
1921  * xs_local_setup_socket - create AF_LOCAL socket, connect to a local endpoint
1922  * @xprt: RPC transport to connect
1923  * @transport: socket transport to connect
1924  * @create_sock: function to create a socket of the correct type
1925  */
1926 static int xs_local_setup_socket(struct sock_xprt *transport)
1927 {
1928         struct rpc_xprt *xprt = &transport->xprt;
1929         struct socket *sock;
1930         int status = -EIO;
1931
1932         current->flags |= PF_FSTRANS;
1933
1934         clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
1935         status = __sock_create(xprt->xprt_net, AF_LOCAL,
1936                                         SOCK_STREAM, 0, &sock, 1);
1937         if (status < 0) {
1938                 dprintk("RPC:       can't create AF_LOCAL "
1939                         "transport socket (%d).\n", -status);
1940                 goto out;
1941         }
1942         xs_reclassify_socketu(sock);
1943
1944         dprintk("RPC:       worker connecting xprt %p via AF_LOCAL to %s\n",
1945                         xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1946
1947         status = xs_local_finish_connecting(xprt, sock);
1948         trace_rpc_socket_connect(xprt, sock, status);
1949         switch (status) {
1950         case 0:
1951                 dprintk("RPC:       xprt %p connected to %s\n",
1952                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1953                 xprt_set_connected(xprt);
1954                 break;
1955         case -ENOENT:
1956                 dprintk("RPC:       xprt %p: socket %s does not exist\n",
1957                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1958                 break;
1959         case -ECONNREFUSED:
1960                 dprintk("RPC:       xprt %p: connection refused for %s\n",
1961                                 xprt, xprt->address_strings[RPC_DISPLAY_ADDR]);
1962                 break;
1963         default:
1964                 printk(KERN_ERR "%s: unhandled error (%d) connecting to %s\n",
1965                                 __func__, -status,
1966                                 xprt->address_strings[RPC_DISPLAY_ADDR]);
1967         }
1968
1969 out:
1970         xprt_clear_connecting(xprt);
1971         xprt_wake_pending_tasks(xprt, status);
1972         current->flags &= ~PF_FSTRANS;
1973         return status;
1974 }
1975
1976 static void xs_local_connect(struct rpc_xprt *xprt, struct rpc_task *task)
1977 {
1978         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
1979         int ret;
1980
1981          if (RPC_IS_ASYNC(task)) {
1982                 /*
1983                  * We want the AF_LOCAL connect to be resolved in the
1984                  * filesystem namespace of the process making the rpc
1985                  * call.  Thus we connect synchronously.
1986                  *
1987                  * If we want to support asynchronous AF_LOCAL calls,
1988                  * we'll need to figure out how to pass a namespace to
1989                  * connect.
1990                  */
1991                 rpc_exit(task, -ENOTCONN);
1992                 return;
1993         }
1994         ret = xs_local_setup_socket(transport);
1995         if (ret && !RPC_IS_SOFTCONN(task))
1996                 msleep_interruptible(15000);
1997 }
1998
1999 #ifdef CONFIG_SUNRPC_SWAP
2000 static void xs_set_memalloc(struct rpc_xprt *xprt)
2001 {
2002         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2003                         xprt);
2004
2005         if (xprt->swapper)
2006                 sk_set_memalloc(transport->inet);
2007 }
2008
2009 /**
2010  * xs_swapper - Tag this transport as being used for swap.
2011  * @xprt: transport to tag
2012  * @enable: enable/disable
2013  *
2014  */
2015 int xs_swapper(struct rpc_xprt *xprt, int enable)
2016 {
2017         struct sock_xprt *transport = container_of(xprt, struct sock_xprt,
2018                         xprt);
2019         int err = 0;
2020
2021         if (enable) {
2022                 xprt->swapper++;
2023                 xs_set_memalloc(xprt);
2024         } else if (xprt->swapper) {
2025                 xprt->swapper--;
2026                 sk_clear_memalloc(transport->inet);
2027         }
2028
2029         return err;
2030 }
2031 EXPORT_SYMBOL_GPL(xs_swapper);
2032 #else
2033 static void xs_set_memalloc(struct rpc_xprt *xprt)
2034 {
2035 }
2036 #endif
2037
2038 static void xs_udp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2039 {
2040         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2041
2042         if (!transport->inet) {
2043                 struct sock *sk = sock->sk;
2044
2045                 write_lock_bh(&sk->sk_callback_lock);
2046
2047                 xs_save_old_callbacks(transport, sk);
2048
2049                 sk->sk_user_data = xprt;
2050                 sk->sk_data_ready = xs_udp_data_ready;
2051                 sk->sk_write_space = xs_udp_write_space;
2052                 sk->sk_no_check = UDP_CSUM_NORCV;
2053                 sk->sk_allocation = GFP_ATOMIC;
2054
2055                 xprt_set_connected(xprt);
2056
2057                 /* Reset to new socket */
2058                 transport->sock = sock;
2059                 transport->inet = sk;
2060
2061                 xs_set_memalloc(xprt);
2062
2063                 write_unlock_bh(&sk->sk_callback_lock);
2064         }
2065         xs_udp_do_set_buffer_size(xprt);
2066 }
2067
2068 static void xs_udp_setup_socket(struct work_struct *work)
2069 {
2070         struct sock_xprt *transport =
2071                 container_of(work, struct sock_xprt, connect_worker.work);
2072         struct rpc_xprt *xprt = &transport->xprt;
2073         struct socket *sock = transport->sock;
2074         int status = -EIO;
2075
2076         current->flags |= PF_FSTRANS;
2077
2078         /* Start by resetting any existing state */
2079         xs_reset_transport(transport);
2080         sock = xs_create_sock(xprt, transport,
2081                         xs_addr(xprt)->sa_family, SOCK_DGRAM, IPPROTO_UDP);
2082         if (IS_ERR(sock))
2083                 goto out;
2084
2085         dprintk("RPC:       worker connecting xprt %p via %s to "
2086                                 "%s (port %s)\n", xprt,
2087                         xprt->address_strings[RPC_DISPLAY_PROTO],
2088                         xprt->address_strings[RPC_DISPLAY_ADDR],
2089                         xprt->address_strings[RPC_DISPLAY_PORT]);
2090
2091         xs_udp_finish_connecting(xprt, sock);
2092         trace_rpc_socket_connect(xprt, sock, 0);
2093         status = 0;
2094 out:
2095         xprt_clear_connecting(xprt);
2096         xprt_wake_pending_tasks(xprt, status);
2097         current->flags &= ~PF_FSTRANS;
2098 }
2099
2100 /*
2101  * We need to preserve the port number so the reply cache on the server can
2102  * find our cached RPC replies when we get around to reconnecting.
2103  */
2104 static void xs_abort_connection(struct sock_xprt *transport)
2105 {
2106         int result;
2107         struct sockaddr any;
2108
2109         dprintk("RPC:       disconnecting xprt %p to reuse port\n", transport);
2110
2111         /*
2112          * Disconnect the transport socket by doing a connect operation
2113          * with AF_UNSPEC.  This should return immediately...
2114          */
2115         memset(&any, 0, sizeof(any));
2116         any.sa_family = AF_UNSPEC;
2117         result = kernel_connect(transport->sock, &any, sizeof(any), 0);
2118         trace_rpc_socket_reset_connection(&transport->xprt,
2119                         transport->sock, result);
2120         if (!result)
2121                 xs_sock_reset_connection_flags(&transport->xprt);
2122         dprintk("RPC:       AF_UNSPEC connect return code %d\n", result);
2123 }
2124
2125 static void xs_tcp_reuse_connection(struct sock_xprt *transport)
2126 {
2127         unsigned int state = transport->inet->sk_state;
2128
2129         if (state == TCP_CLOSE && transport->sock->state == SS_UNCONNECTED) {
2130                 /* we don't need to abort the connection if the socket
2131                  * hasn't undergone a shutdown
2132                  */
2133                 if (transport->inet->sk_shutdown == 0)
2134                         return;
2135                 dprintk("RPC:       %s: TCP_CLOSEd and sk_shutdown set to %d\n",
2136                                 __func__, transport->inet->sk_shutdown);
2137         }
2138         if ((1 << state) & (TCPF_ESTABLISHED|TCPF_SYN_SENT)) {
2139                 /* we don't need to abort the connection if the socket
2140                  * hasn't undergone a shutdown
2141                  */
2142                 if (transport->inet->sk_shutdown == 0)
2143                         return;
2144                 dprintk("RPC:       %s: ESTABLISHED/SYN_SENT "
2145                                 "sk_shutdown set to %d\n",
2146                                 __func__, transport->inet->sk_shutdown);
2147         }
2148         xs_abort_connection(transport);
2149 }
2150
2151 static int xs_tcp_finish_connecting(struct rpc_xprt *xprt, struct socket *sock)
2152 {
2153         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2154         int ret = -ENOTCONN;
2155
2156         if (!transport->inet) {
2157                 struct sock *sk = sock->sk;
2158                 unsigned int keepidle = xprt->timeout->to_initval / HZ;
2159                 unsigned int keepcnt = xprt->timeout->to_retries + 1;
2160                 unsigned int opt_on = 1;
2161
2162                 /* TCP Keepalive options */
2163                 kernel_setsockopt(sock, SOL_SOCKET, SO_KEEPALIVE,
2164                                 (char *)&opt_on, sizeof(opt_on));
2165                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPIDLE,
2166                                 (char *)&keepidle, sizeof(keepidle));
2167                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPINTVL,
2168                                 (char *)&keepidle, sizeof(keepidle));
2169                 kernel_setsockopt(sock, SOL_TCP, TCP_KEEPCNT,
2170                                 (char *)&keepcnt, sizeof(keepcnt));
2171
2172                 write_lock_bh(&sk->sk_callback_lock);
2173
2174                 xs_save_old_callbacks(transport, sk);
2175
2176                 sk->sk_user_data = xprt;
2177                 sk->sk_data_ready = xs_tcp_data_ready;
2178                 sk->sk_state_change = xs_tcp_state_change;
2179                 sk->sk_write_space = xs_tcp_write_space;
2180                 sk->sk_error_report = xs_error_report;
2181                 sk->sk_allocation = GFP_ATOMIC;
2182
2183                 /* socket options */
2184                 sk->sk_userlocks |= SOCK_BINDPORT_LOCK;
2185                 sock_reset_flag(sk, SOCK_LINGER);
2186                 tcp_sk(sk)->linger2 = 0;
2187                 tcp_sk(sk)->nonagle |= TCP_NAGLE_OFF;
2188
2189                 xprt_clear_connected(xprt);
2190
2191                 /* Reset to new socket */
2192                 transport->sock = sock;
2193                 transport->inet = sk;
2194
2195                 write_unlock_bh(&sk->sk_callback_lock);
2196         }
2197
2198         if (!xprt_bound(xprt))
2199                 goto out;
2200
2201         xs_set_memalloc(xprt);
2202
2203         /* Tell the socket layer to start connecting... */
2204         xprt->stat.connect_count++;
2205         xprt->stat.connect_start = jiffies;
2206         ret = kernel_connect(sock, xs_addr(xprt), xprt->addrlen, O_NONBLOCK);
2207         switch (ret) {
2208         case 0:
2209         case -EINPROGRESS:
2210                 /* SYN_SENT! */
2211                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2212                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2213         }
2214 out:
2215         return ret;
2216 }
2217
2218 /**
2219  * xs_tcp_setup_socket - create a TCP socket and connect to a remote endpoint
2220  * @xprt: RPC transport to connect
2221  * @transport: socket transport to connect
2222  * @create_sock: function to create a socket of the correct type
2223  *
2224  * Invoked by a work queue tasklet.
2225  */
2226 static void xs_tcp_setup_socket(struct work_struct *work)
2227 {
2228         struct sock_xprt *transport =
2229                 container_of(work, struct sock_xprt, connect_worker.work);
2230         struct socket *sock = transport->sock;
2231         struct rpc_xprt *xprt = &transport->xprt;
2232         int status = -EIO;
2233
2234         current->flags |= PF_FSTRANS;
2235
2236         if (!sock) {
2237                 clear_bit(XPRT_CONNECTION_ABORT, &xprt->state);
2238                 sock = xs_create_sock(xprt, transport,
2239                                 xs_addr(xprt)->sa_family, SOCK_STREAM, IPPROTO_TCP);
2240                 if (IS_ERR(sock)) {
2241                         status = PTR_ERR(sock);
2242                         goto out;
2243                 }
2244         } else {
2245                 int abort_and_exit;
2246
2247                 abort_and_exit = test_and_clear_bit(XPRT_CONNECTION_ABORT,
2248                                 &xprt->state);
2249                 /* "close" the socket, preserving the local port */
2250                 xs_tcp_reuse_connection(transport);
2251
2252                 if (abort_and_exit)
2253                         goto out_eagain;
2254         }
2255
2256         dprintk("RPC:       worker connecting xprt %p via %s to "
2257                                 "%s (port %s)\n", xprt,
2258                         xprt->address_strings[RPC_DISPLAY_PROTO],
2259                         xprt->address_strings[RPC_DISPLAY_ADDR],
2260                         xprt->address_strings[RPC_DISPLAY_PORT]);
2261
2262         status = xs_tcp_finish_connecting(xprt, sock);
2263         trace_rpc_socket_connect(xprt, sock, status);
2264         dprintk("RPC:       %p connect status %d connected %d sock state %d\n",
2265                         xprt, -status, xprt_connected(xprt),
2266                         sock->sk->sk_state);
2267         switch (status) {
2268         default:
2269                 printk("%s: connect returned unhandled error %d\n",
2270                         __func__, status);
2271         case -EADDRNOTAVAIL:
2272                 /* We're probably in TIME_WAIT. Get rid of existing socket,
2273                  * and retry
2274                  */
2275                 xs_tcp_force_close(xprt);
2276                 break;
2277         case 0:
2278         case -EINPROGRESS:
2279         case -EALREADY:
2280                 xprt_clear_connecting(xprt);
2281                 current->flags &= ~PF_FSTRANS;
2282                 return;
2283         case -EINVAL:
2284                 /* Happens, for instance, if the user specified a link
2285                  * local IPv6 address without a scope-id.
2286                  */
2287         case -ECONNREFUSED:
2288         case -ECONNRESET:
2289         case -ENETUNREACH:
2290                 /* retry with existing socket, after a delay */
2291                 goto out;
2292         }
2293 out_eagain:
2294         status = -EAGAIN;
2295 out:
2296         xprt_clear_connecting(xprt);
2297         xprt_wake_pending_tasks(xprt, status);
2298         current->flags &= ~PF_FSTRANS;
2299 }
2300
2301 /**
2302  * xs_connect - connect a socket to a remote endpoint
2303  * @xprt: pointer to transport structure
2304  * @task: address of RPC task that manages state of connect request
2305  *
2306  * TCP: If the remote end dropped the connection, delay reconnecting.
2307  *
2308  * UDP socket connects are synchronous, but we use a work queue anyway
2309  * to guarantee that even unprivileged user processes can set up a
2310  * socket on a privileged port.
2311  *
2312  * If a UDP socket connect fails, the delay behavior here prevents
2313  * retry floods (hard mounts).
2314  */
2315 static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task)
2316 {
2317         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2318
2319         if (transport->sock != NULL && !RPC_IS_SOFTCONN(task)) {
2320                 dprintk("RPC:       xs_connect delayed xprt %p for %lu "
2321                                 "seconds\n",
2322                                 xprt, xprt->reestablish_timeout / HZ);
2323                 queue_delayed_work(rpciod_workqueue,
2324                                    &transport->connect_worker,
2325                                    xprt->reestablish_timeout);
2326                 xprt->reestablish_timeout <<= 1;
2327                 if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO)
2328                         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2329                 if (xprt->reestablish_timeout > XS_TCP_MAX_REEST_TO)
2330                         xprt->reestablish_timeout = XS_TCP_MAX_REEST_TO;
2331         } else {
2332                 dprintk("RPC:       xs_connect scheduled xprt %p\n", xprt);
2333                 queue_delayed_work(rpciod_workqueue,
2334                                    &transport->connect_worker, 0);
2335         }
2336 }
2337
2338 /**
2339  * xs_local_print_stats - display AF_LOCAL socket-specifc stats
2340  * @xprt: rpc_xprt struct containing statistics
2341  * @seq: output file
2342  *
2343  */
2344 static void xs_local_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2345 {
2346         long idle_time = 0;
2347
2348         if (xprt_connected(xprt))
2349                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2350
2351         seq_printf(seq, "\txprt:\tlocal %lu %lu %lu %ld %lu %lu %lu "
2352                         "%llu %llu %lu %llu %llu\n",
2353                         xprt->stat.bind_count,
2354                         xprt->stat.connect_count,
2355                         xprt->stat.connect_time,
2356                         idle_time,
2357                         xprt->stat.sends,
2358                         xprt->stat.recvs,
2359                         xprt->stat.bad_xids,
2360                         xprt->stat.req_u,
2361                         xprt->stat.bklog_u,
2362                         xprt->stat.max_slots,
2363                         xprt->stat.sending_u,
2364                         xprt->stat.pending_u);
2365 }
2366
2367 /**
2368  * xs_udp_print_stats - display UDP socket-specifc stats
2369  * @xprt: rpc_xprt struct containing statistics
2370  * @seq: output file
2371  *
2372  */
2373 static void xs_udp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2374 {
2375         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2376
2377         seq_printf(seq, "\txprt:\tudp %u %lu %lu %lu %lu %llu %llu "
2378                         "%lu %llu %llu\n",
2379                         transport->srcport,
2380                         xprt->stat.bind_count,
2381                         xprt->stat.sends,
2382                         xprt->stat.recvs,
2383                         xprt->stat.bad_xids,
2384                         xprt->stat.req_u,
2385                         xprt->stat.bklog_u,
2386                         xprt->stat.max_slots,
2387                         xprt->stat.sending_u,
2388                         xprt->stat.pending_u);
2389 }
2390
2391 /**
2392  * xs_tcp_print_stats - display TCP socket-specifc stats
2393  * @xprt: rpc_xprt struct containing statistics
2394  * @seq: output file
2395  *
2396  */
2397 static void xs_tcp_print_stats(struct rpc_xprt *xprt, struct seq_file *seq)
2398 {
2399         struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt);
2400         long idle_time = 0;
2401
2402         if (xprt_connected(xprt))
2403                 idle_time = (long)(jiffies - xprt->last_used) / HZ;
2404
2405         seq_printf(seq, "\txprt:\ttcp %u %lu %lu %lu %ld %lu %lu %lu "
2406                         "%llu %llu %lu %llu %llu\n",
2407                         transport->srcport,
2408                         xprt->stat.bind_count,
2409                         xprt->stat.connect_count,
2410                         xprt->stat.connect_time,
2411                         idle_time,
2412                         xprt->stat.sends,
2413                         xprt->stat.recvs,
2414                         xprt->stat.bad_xids,
2415                         xprt->stat.req_u,
2416                         xprt->stat.bklog_u,
2417                         xprt->stat.max_slots,
2418                         xprt->stat.sending_u,
2419                         xprt->stat.pending_u);
2420 }
2421
2422 /*
2423  * Allocate a bunch of pages for a scratch buffer for the rpc code. The reason
2424  * we allocate pages instead doing a kmalloc like rpc_malloc is because we want
2425  * to use the server side send routines.
2426  */
2427 static void *bc_malloc(struct rpc_task *task, size_t size)
2428 {
2429         struct page *page;
2430         struct rpc_buffer *buf;
2431
2432         WARN_ON_ONCE(size > PAGE_SIZE - sizeof(struct rpc_buffer));
2433         if (size > PAGE_SIZE - sizeof(struct rpc_buffer))
2434                 return NULL;
2435
2436         page = alloc_page(GFP_KERNEL);
2437         if (!page)
2438                 return NULL;
2439
2440         buf = page_address(page);
2441         buf->len = PAGE_SIZE;
2442
2443         return buf->data;
2444 }
2445
2446 /*
2447  * Free the space allocated in the bc_alloc routine
2448  */
2449 static void bc_free(void *buffer)
2450 {
2451         struct rpc_buffer *buf;
2452
2453         if (!buffer)
2454                 return;
2455
2456         buf = container_of(buffer, struct rpc_buffer, data);
2457         free_page((unsigned long)buf);
2458 }
2459
2460 /*
2461  * Use the svc_sock to send the callback. Must be called with svsk->sk_mutex
2462  * held. Borrows heavily from svc_tcp_sendto and xs_tcp_send_request.
2463  */
2464 static int bc_sendto(struct rpc_rqst *req)
2465 {
2466         int len;
2467         struct xdr_buf *xbufp = &req->rq_snd_buf;
2468         struct rpc_xprt *xprt = req->rq_xprt;
2469         struct sock_xprt *transport =
2470                                 container_of(xprt, struct sock_xprt, xprt);
2471         struct socket *sock = transport->sock;
2472         unsigned long headoff;
2473         unsigned long tailoff;
2474
2475         xs_encode_stream_record_marker(xbufp);
2476
2477         tailoff = (unsigned long)xbufp->tail[0].iov_base & ~PAGE_MASK;
2478         headoff = (unsigned long)xbufp->head[0].iov_base & ~PAGE_MASK;
2479         len = svc_send_common(sock, xbufp,
2480                               virt_to_page(xbufp->head[0].iov_base), headoff,
2481                               xbufp->tail[0].iov_base, tailoff);
2482
2483         if (len != xbufp->len) {
2484                 printk(KERN_NOTICE "Error sending entire callback!\n");
2485                 len = -EAGAIN;
2486         }
2487
2488         return len;
2489 }
2490
2491 /*
2492  * The send routine. Borrows from svc_send
2493  */
2494 static int bc_send_request(struct rpc_task *task)
2495 {
2496         struct rpc_rqst *req = task->tk_rqstp;
2497         struct svc_xprt *xprt;
2498         u32                     len;
2499
2500         dprintk("sending request with xid: %08x\n", ntohl(req->rq_xid));
2501         /*
2502          * Get the server socket associated with this callback xprt
2503          */
2504         xprt = req->rq_xprt->bc_xprt;
2505
2506         /*
2507          * Grab the mutex to serialize data as the connection is shared
2508          * with the fore channel
2509          */
2510         if (!mutex_trylock(&xprt->xpt_mutex)) {
2511                 rpc_sleep_on(&xprt->xpt_bc_pending, task, NULL);
2512                 if (!mutex_trylock(&xprt->xpt_mutex))
2513                         return -EAGAIN;
2514                 rpc_wake_up_queued_task(&xprt->xpt_bc_pending, task);
2515         }
2516         if (test_bit(XPT_DEAD, &xprt->xpt_flags))
2517                 len = -ENOTCONN;
2518         else
2519                 len = bc_sendto(req);
2520         mutex_unlock(&xprt->xpt_mutex);
2521
2522         if (len > 0)
2523                 len = 0;
2524
2525         return len;
2526 }
2527
2528 /*
2529  * The close routine. Since this is client initiated, we do nothing
2530  */
2531
2532 static void bc_close(struct rpc_xprt *xprt)
2533 {
2534 }
2535
2536 /*
2537  * The xprt destroy routine. Again, because this connection is client
2538  * initiated, we do nothing
2539  */
2540
2541 static void bc_destroy(struct rpc_xprt *xprt)
2542 {
2543 }
2544
2545 static struct rpc_xprt_ops xs_local_ops = {
2546         .reserve_xprt           = xprt_reserve_xprt,
2547         .release_xprt           = xs_tcp_release_xprt,
2548         .alloc_slot             = xprt_alloc_slot,
2549         .rpcbind                = xs_local_rpcbind,
2550         .set_port               = xs_local_set_port,
2551         .connect                = xs_local_connect,
2552         .buf_alloc              = rpc_malloc,
2553         .buf_free               = rpc_free,
2554         .send_request           = xs_local_send_request,
2555         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2556         .close                  = xs_close,
2557         .destroy                = xs_destroy,
2558         .print_stats            = xs_local_print_stats,
2559 };
2560
2561 static struct rpc_xprt_ops xs_udp_ops = {
2562         .set_buffer_size        = xs_udp_set_buffer_size,
2563         .reserve_xprt           = xprt_reserve_xprt_cong,
2564         .release_xprt           = xprt_release_xprt_cong,
2565         .alloc_slot             = xprt_alloc_slot,
2566         .rpcbind                = rpcb_getport_async,
2567         .set_port               = xs_set_port,
2568         .connect                = xs_connect,
2569         .buf_alloc              = rpc_malloc,
2570         .buf_free               = rpc_free,
2571         .send_request           = xs_udp_send_request,
2572         .set_retrans_timeout    = xprt_set_retrans_timeout_rtt,
2573         .timer                  = xs_udp_timer,
2574         .release_request        = xprt_release_rqst_cong,
2575         .close                  = xs_close,
2576         .destroy                = xs_destroy,
2577         .print_stats            = xs_udp_print_stats,
2578 };
2579
2580 static struct rpc_xprt_ops xs_tcp_ops = {
2581         .reserve_xprt           = xprt_reserve_xprt,
2582         .release_xprt           = xs_tcp_release_xprt,
2583         .alloc_slot             = xprt_lock_and_alloc_slot,
2584         .rpcbind                = rpcb_getport_async,
2585         .set_port               = xs_set_port,
2586         .connect                = xs_connect,
2587         .buf_alloc              = rpc_malloc,
2588         .buf_free               = rpc_free,
2589         .send_request           = xs_tcp_send_request,
2590         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2591         .close                  = xs_tcp_close,
2592         .destroy                = xs_destroy,
2593         .print_stats            = xs_tcp_print_stats,
2594 };
2595
2596 /*
2597  * The rpc_xprt_ops for the server backchannel
2598  */
2599
2600 static struct rpc_xprt_ops bc_tcp_ops = {
2601         .reserve_xprt           = xprt_reserve_xprt,
2602         .release_xprt           = xprt_release_xprt,
2603         .alloc_slot             = xprt_alloc_slot,
2604         .buf_alloc              = bc_malloc,
2605         .buf_free               = bc_free,
2606         .send_request           = bc_send_request,
2607         .set_retrans_timeout    = xprt_set_retrans_timeout_def,
2608         .close                  = bc_close,
2609         .destroy                = bc_destroy,
2610         .print_stats            = xs_tcp_print_stats,
2611 };
2612
2613 static int xs_init_anyaddr(const int family, struct sockaddr *sap)
2614 {
2615         static const struct sockaddr_in sin = {
2616                 .sin_family             = AF_INET,
2617                 .sin_addr.s_addr        = htonl(INADDR_ANY),
2618         };
2619         static const struct sockaddr_in6 sin6 = {
2620                 .sin6_family            = AF_INET6,
2621                 .sin6_addr              = IN6ADDR_ANY_INIT,
2622         };
2623
2624         switch (family) {
2625         case AF_LOCAL:
2626                 break;
2627         case AF_INET:
2628                 memcpy(sap, &sin, sizeof(sin));
2629                 break;
2630         case AF_INET6:
2631                 memcpy(sap, &sin6, sizeof(sin6));
2632                 break;
2633         default:
2634                 dprintk("RPC:       %s: Bad address family\n", __func__);
2635                 return -EAFNOSUPPORT;
2636         }
2637         return 0;
2638 }
2639
2640 static struct rpc_xprt *xs_setup_xprt(struct xprt_create *args,
2641                                       unsigned int slot_table_size,
2642                                       unsigned int max_slot_table_size)
2643 {
2644         struct rpc_xprt *xprt;
2645         struct sock_xprt *new;
2646
2647         if (args->addrlen > sizeof(xprt->addr)) {
2648                 dprintk("RPC:       xs_setup_xprt: address too large\n");
2649                 return ERR_PTR(-EBADF);
2650         }
2651
2652         xprt = xprt_alloc(args->net, sizeof(*new), slot_table_size,
2653                         max_slot_table_size);
2654         if (xprt == NULL) {
2655                 dprintk("RPC:       xs_setup_xprt: couldn't allocate "
2656                                 "rpc_xprt\n");
2657                 return ERR_PTR(-ENOMEM);
2658         }
2659
2660         new = container_of(xprt, struct sock_xprt, xprt);
2661         memcpy(&xprt->addr, args->dstaddr, args->addrlen);
2662         xprt->addrlen = args->addrlen;
2663         if (args->srcaddr)
2664                 memcpy(&new->srcaddr, args->srcaddr, args->addrlen);
2665         else {
2666                 int err;
2667                 err = xs_init_anyaddr(args->dstaddr->sa_family,
2668                                         (struct sockaddr *)&new->srcaddr);
2669                 if (err != 0) {
2670                         xprt_free(xprt);
2671                         return ERR_PTR(err);
2672                 }
2673         }
2674
2675         return xprt;
2676 }
2677
2678 static const struct rpc_timeout xs_local_default_timeout = {
2679         .to_initval = 10 * HZ,
2680         .to_maxval = 10 * HZ,
2681         .to_retries = 2,
2682 };
2683
2684 /**
2685  * xs_setup_local - Set up transport to use an AF_LOCAL socket
2686  * @args: rpc transport creation arguments
2687  *
2688  * AF_LOCAL is a "tpi_cots_ord" transport, just like TCP
2689  */
2690 static struct rpc_xprt *xs_setup_local(struct xprt_create *args)
2691 {
2692         struct sockaddr_un *sun = (struct sockaddr_un *)args->dstaddr;
2693         struct sock_xprt *transport;
2694         struct rpc_xprt *xprt;
2695         struct rpc_xprt *ret;
2696
2697         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2698                         xprt_max_tcp_slot_table_entries);
2699         if (IS_ERR(xprt))
2700                 return xprt;
2701         transport = container_of(xprt, struct sock_xprt, xprt);
2702
2703         xprt->prot = 0;
2704         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2705         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2706
2707         xprt->bind_timeout = XS_BIND_TO;
2708         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2709         xprt->idle_timeout = XS_IDLE_DISC_TO;
2710
2711         xprt->ops = &xs_local_ops;
2712         xprt->timeout = &xs_local_default_timeout;
2713
2714         INIT_DELAYED_WORK(&transport->connect_worker,
2715                         xs_dummy_setup_socket);
2716
2717         switch (sun->sun_family) {
2718         case AF_LOCAL:
2719                 if (sun->sun_path[0] != '/') {
2720                         dprintk("RPC:       bad AF_LOCAL address: %s\n",
2721                                         sun->sun_path);
2722                         ret = ERR_PTR(-EINVAL);
2723                         goto out_err;
2724                 }
2725                 xprt_set_bound(xprt);
2726                 xs_format_peer_addresses(xprt, "local", RPCBIND_NETID_LOCAL);
2727                 ret = ERR_PTR(xs_local_setup_socket(transport));
2728                 if (ret)
2729                         goto out_err;
2730                 break;
2731         default:
2732                 ret = ERR_PTR(-EAFNOSUPPORT);
2733                 goto out_err;
2734         }
2735
2736         dprintk("RPC:       set up xprt to %s via AF_LOCAL\n",
2737                         xprt->address_strings[RPC_DISPLAY_ADDR]);
2738
2739         if (try_module_get(THIS_MODULE))
2740                 return xprt;
2741         ret = ERR_PTR(-EINVAL);
2742 out_err:
2743         xprt_free(xprt);
2744         return ret;
2745 }
2746
2747 static const struct rpc_timeout xs_udp_default_timeout = {
2748         .to_initval = 5 * HZ,
2749         .to_maxval = 30 * HZ,
2750         .to_increment = 5 * HZ,
2751         .to_retries = 5,
2752 };
2753
2754 /**
2755  * xs_setup_udp - Set up transport to use a UDP socket
2756  * @args: rpc transport creation arguments
2757  *
2758  */
2759 static struct rpc_xprt *xs_setup_udp(struct xprt_create *args)
2760 {
2761         struct sockaddr *addr = args->dstaddr;
2762         struct rpc_xprt *xprt;
2763         struct sock_xprt *transport;
2764         struct rpc_xprt *ret;
2765
2766         xprt = xs_setup_xprt(args, xprt_udp_slot_table_entries,
2767                         xprt_udp_slot_table_entries);
2768         if (IS_ERR(xprt))
2769                 return xprt;
2770         transport = container_of(xprt, struct sock_xprt, xprt);
2771
2772         xprt->prot = IPPROTO_UDP;
2773         xprt->tsh_size = 0;
2774         /* XXX: header size can vary due to auth type, IPv6, etc. */
2775         xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
2776
2777         xprt->bind_timeout = XS_BIND_TO;
2778         xprt->reestablish_timeout = XS_UDP_REEST_TO;
2779         xprt->idle_timeout = XS_IDLE_DISC_TO;
2780
2781         xprt->ops = &xs_udp_ops;
2782
2783         xprt->timeout = &xs_udp_default_timeout;
2784
2785         switch (addr->sa_family) {
2786         case AF_INET:
2787                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2788                         xprt_set_bound(xprt);
2789
2790                 INIT_DELAYED_WORK(&transport->connect_worker,
2791                                         xs_udp_setup_socket);
2792                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP);
2793                 break;
2794         case AF_INET6:
2795                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2796                         xprt_set_bound(xprt);
2797
2798                 INIT_DELAYED_WORK(&transport->connect_worker,
2799                                         xs_udp_setup_socket);
2800                 xs_format_peer_addresses(xprt, "udp", RPCBIND_NETID_UDP6);
2801                 break;
2802         default:
2803                 ret = ERR_PTR(-EAFNOSUPPORT);
2804                 goto out_err;
2805         }
2806
2807         if (xprt_bound(xprt))
2808                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2809                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2810                                 xprt->address_strings[RPC_DISPLAY_PORT],
2811                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2812         else
2813                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2814                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2815                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2816
2817         if (try_module_get(THIS_MODULE))
2818                 return xprt;
2819         ret = ERR_PTR(-EINVAL);
2820 out_err:
2821         xprt_free(xprt);
2822         return ret;
2823 }
2824
2825 static const struct rpc_timeout xs_tcp_default_timeout = {
2826         .to_initval = 60 * HZ,
2827         .to_maxval = 60 * HZ,
2828         .to_retries = 2,
2829 };
2830
2831 /**
2832  * xs_setup_tcp - Set up transport to use a TCP socket
2833  * @args: rpc transport creation arguments
2834  *
2835  */
2836 static struct rpc_xprt *xs_setup_tcp(struct xprt_create *args)
2837 {
2838         struct sockaddr *addr = args->dstaddr;
2839         struct rpc_xprt *xprt;
2840         struct sock_xprt *transport;
2841         struct rpc_xprt *ret;
2842         unsigned int max_slot_table_size = xprt_max_tcp_slot_table_entries;
2843
2844         if (args->flags & XPRT_CREATE_INFINITE_SLOTS)
2845                 max_slot_table_size = RPC_MAX_SLOT_TABLE_LIMIT;
2846
2847         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2848                         max_slot_table_size);
2849         if (IS_ERR(xprt))
2850                 return xprt;
2851         transport = container_of(xprt, struct sock_xprt, xprt);
2852
2853         xprt->prot = IPPROTO_TCP;
2854         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2855         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2856
2857         xprt->bind_timeout = XS_BIND_TO;
2858         xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO;
2859         xprt->idle_timeout = XS_IDLE_DISC_TO;
2860
2861         xprt->ops = &xs_tcp_ops;
2862         xprt->timeout = &xs_tcp_default_timeout;
2863
2864         switch (addr->sa_family) {
2865         case AF_INET:
2866                 if (((struct sockaddr_in *)addr)->sin_port != htons(0))
2867                         xprt_set_bound(xprt);
2868
2869                 INIT_DELAYED_WORK(&transport->connect_worker,
2870                                         xs_tcp_setup_socket);
2871                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP);
2872                 break;
2873         case AF_INET6:
2874                 if (((struct sockaddr_in6 *)addr)->sin6_port != htons(0))
2875                         xprt_set_bound(xprt);
2876
2877                 INIT_DELAYED_WORK(&transport->connect_worker,
2878                                         xs_tcp_setup_socket);
2879                 xs_format_peer_addresses(xprt, "tcp", RPCBIND_NETID_TCP6);
2880                 break;
2881         default:
2882                 ret = ERR_PTR(-EAFNOSUPPORT);
2883                 goto out_err;
2884         }
2885
2886         if (xprt_bound(xprt))
2887                 dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2888                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2889                                 xprt->address_strings[RPC_DISPLAY_PORT],
2890                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2891         else
2892                 dprintk("RPC:       set up xprt to %s (autobind) via %s\n",
2893                                 xprt->address_strings[RPC_DISPLAY_ADDR],
2894                                 xprt->address_strings[RPC_DISPLAY_PROTO]);
2895
2896
2897         if (try_module_get(THIS_MODULE))
2898                 return xprt;
2899         ret = ERR_PTR(-EINVAL);
2900 out_err:
2901         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         if (args->bc_xprt->xpt_bc_xprt) {
2919                 /*
2920                  * This server connection already has a backchannel
2921                  * transport; we can't create a new one, as we wouldn't
2922                  * be able to match replies based on xid any more.  So,
2923                  * reuse the already-existing one:
2924                  */
2925                  return args->bc_xprt->xpt_bc_xprt;
2926         }
2927         xprt = xs_setup_xprt(args, xprt_tcp_slot_table_entries,
2928                         xprt_tcp_slot_table_entries);
2929         if (IS_ERR(xprt))
2930                 return xprt;
2931         transport = container_of(xprt, struct sock_xprt, xprt);
2932
2933         xprt->prot = IPPROTO_TCP;
2934         xprt->tsh_size = sizeof(rpc_fraghdr) / sizeof(u32);
2935         xprt->max_payload = RPC_MAX_FRAGMENT_SIZE;
2936         xprt->timeout = &xs_tcp_default_timeout;
2937
2938         /* backchannel */
2939         xprt_set_bound(xprt);
2940         xprt->bind_timeout = 0;
2941         xprt->reestablish_timeout = 0;
2942         xprt->idle_timeout = 0;
2943
2944         xprt->ops = &bc_tcp_ops;
2945
2946         switch (addr->sa_family) {
2947         case AF_INET:
2948                 xs_format_peer_addresses(xprt, "tcp",
2949                                          RPCBIND_NETID_TCP);
2950                 break;
2951         case AF_INET6:
2952                 xs_format_peer_addresses(xprt, "tcp",
2953                                    RPCBIND_NETID_TCP6);
2954                 break;
2955         default:
2956                 ret = ERR_PTR(-EAFNOSUPPORT);
2957                 goto out_err;
2958         }
2959
2960         dprintk("RPC:       set up xprt to %s (port %s) via %s\n",
2961                         xprt->address_strings[RPC_DISPLAY_ADDR],
2962                         xprt->address_strings[RPC_DISPLAY_PORT],
2963                         xprt->address_strings[RPC_DISPLAY_PROTO]);
2964
2965         /*
2966          * Once we've associated a backchannel xprt with a connection,
2967          * we want to keep it around as long as the connection lasts,
2968          * in case we need to start using it for a backchannel again;
2969          * this reference won't be dropped until bc_xprt is destroyed.
2970          */
2971         xprt_get(xprt);
2972         args->bc_xprt->xpt_bc_xprt = xprt;
2973         xprt->bc_xprt = args->bc_xprt;
2974         bc_sock = container_of(args->bc_xprt, struct svc_sock, sk_xprt);
2975         transport->sock = bc_sock->sk_sock;
2976         transport->inet = bc_sock->sk_sk;
2977
2978         /*
2979          * Since we don't want connections for the backchannel, we set
2980          * the xprt status to connected
2981          */
2982         xprt_set_connected(xprt);
2983
2984
2985         if (try_module_get(THIS_MODULE))
2986                 return xprt;
2987         xprt_put(xprt);
2988         ret = ERR_PTR(-EINVAL);
2989 out_err:
2990         xprt_free(xprt);
2991         return ret;
2992 }
2993
2994 static struct xprt_class        xs_local_transport = {
2995         .list           = LIST_HEAD_INIT(xs_local_transport.list),
2996         .name           = "named UNIX socket",
2997         .owner          = THIS_MODULE,
2998         .ident          = XPRT_TRANSPORT_LOCAL,
2999         .setup          = xs_setup_local,
3000 };
3001
3002 static struct xprt_class        xs_udp_transport = {
3003         .list           = LIST_HEAD_INIT(xs_udp_transport.list),
3004         .name           = "udp",
3005         .owner          = THIS_MODULE,
3006         .ident          = XPRT_TRANSPORT_UDP,
3007         .setup          = xs_setup_udp,
3008 };
3009
3010 static struct xprt_class        xs_tcp_transport = {
3011         .list           = LIST_HEAD_INIT(xs_tcp_transport.list),
3012         .name           = "tcp",
3013         .owner          = THIS_MODULE,
3014         .ident          = XPRT_TRANSPORT_TCP,
3015         .setup          = xs_setup_tcp,
3016 };
3017
3018 static struct xprt_class        xs_bc_tcp_transport = {
3019         .list           = LIST_HEAD_INIT(xs_bc_tcp_transport.list),
3020         .name           = "tcp NFSv4.1 backchannel",
3021         .owner          = THIS_MODULE,
3022         .ident          = XPRT_TRANSPORT_BC_TCP,
3023         .setup          = xs_setup_bc_tcp,
3024 };
3025
3026 /**
3027  * init_socket_xprt - set up xprtsock's sysctls, register with RPC client
3028  *
3029  */
3030 int init_socket_xprt(void)
3031 {
3032 #ifdef RPC_DEBUG
3033         if (!sunrpc_table_header)
3034                 sunrpc_table_header = register_sysctl_table(sunrpc_table);
3035 #endif
3036
3037         xprt_register_transport(&xs_local_transport);
3038         xprt_register_transport(&xs_udp_transport);
3039         xprt_register_transport(&xs_tcp_transport);
3040         xprt_register_transport(&xs_bc_tcp_transport);
3041
3042         return 0;
3043 }
3044
3045 /**
3046  * cleanup_socket_xprt - remove xprtsock's sysctls, unregister
3047  *
3048  */
3049 void cleanup_socket_xprt(void)
3050 {
3051 #ifdef RPC_DEBUG
3052         if (sunrpc_table_header) {
3053                 unregister_sysctl_table(sunrpc_table_header);
3054                 sunrpc_table_header = NULL;
3055         }
3056 #endif
3057
3058         xprt_unregister_transport(&xs_local_transport);
3059         xprt_unregister_transport(&xs_udp_transport);
3060         xprt_unregister_transport(&xs_tcp_transport);
3061         xprt_unregister_transport(&xs_bc_tcp_transport);
3062 }
3063
3064 static int param_set_uint_minmax(const char *val,
3065                 const struct kernel_param *kp,
3066                 unsigned int min, unsigned int max)
3067 {
3068         unsigned long num;
3069         int ret;
3070
3071         if (!val)
3072                 return -EINVAL;
3073         ret = strict_strtoul(val, 0, &num);
3074         if (ret == -EINVAL || num < min || num > max)
3075                 return -EINVAL;
3076         *((unsigned int *)kp->arg) = num;
3077         return 0;
3078 }
3079
3080 static int param_set_portnr(const char *val, const struct kernel_param *kp)
3081 {
3082         return param_set_uint_minmax(val, kp,
3083                         RPC_MIN_RESVPORT,
3084                         RPC_MAX_RESVPORT);
3085 }
3086
3087 static struct kernel_param_ops param_ops_portnr = {
3088         .set = param_set_portnr,
3089         .get = param_get_uint,
3090 };
3091
3092 #define param_check_portnr(name, p) \
3093         __param_check(name, p, unsigned int);
3094
3095 module_param_named(min_resvport, xprt_min_resvport, portnr, 0644);
3096 module_param_named(max_resvport, xprt_max_resvport, portnr, 0644);
3097
3098 static int param_set_slot_table_size(const char *val,
3099                                      const struct kernel_param *kp)
3100 {
3101         return param_set_uint_minmax(val, kp,
3102                         RPC_MIN_SLOT_TABLE,
3103                         RPC_MAX_SLOT_TABLE);
3104 }
3105
3106 static struct kernel_param_ops param_ops_slot_table_size = {
3107         .set = param_set_slot_table_size,
3108         .get = param_get_uint,
3109 };
3110
3111 #define param_check_slot_table_size(name, p) \
3112         __param_check(name, p, unsigned int);
3113
3114 static int param_set_max_slot_table_size(const char *val,
3115                                      const struct kernel_param *kp)
3116 {
3117         return param_set_uint_minmax(val, kp,
3118                         RPC_MIN_SLOT_TABLE,
3119                         RPC_MAX_SLOT_TABLE_LIMIT);
3120 }
3121
3122 static struct kernel_param_ops param_ops_max_slot_table_size = {
3123         .set = param_set_max_slot_table_size,
3124         .get = param_get_uint,
3125 };
3126
3127 #define param_check_max_slot_table_size(name, p) \
3128         __param_check(name, p, unsigned int);
3129
3130 module_param_named(tcp_slot_table_entries, xprt_tcp_slot_table_entries,
3131                    slot_table_size, 0644);
3132 module_param_named(tcp_max_slot_table_entries, xprt_max_tcp_slot_table_entries,
3133                    max_slot_table_size, 0644);
3134 module_param_named(udp_slot_table_entries, xprt_udp_slot_table_entries,
3135                    slot_table_size, 0644);
3136