[PATCH] RPC: introduce client-side transport switch

 Move the bulk of client-side socket-specific code into a separate source
 file, net/sunrpc/xprtsock.c.

 Test-plan:
 Millions of fsx operations.  Performance characterization such as "sio" or
 "iozone".  Destructive testing (unplugging the network temporarily, server
 reboots).  Connectathon with v2, v3, and v4.

 Version: Thu, 11 Aug 2005 16:03:38 -0400

 Signed-off-by: Chuck Lever <cel@netapp.com>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 43 insertions, 873 deletions

diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
index 67444f494fea..4342acf4d1cd 100644
--- a/net/sunrpc/xprt.c
+++ b/net/sunrpc/xprt.c
@@ -32,37 +32,16 @@
  *  tasks that rely on callbacks.
  *
  *  Copyright (C) 1995-1997, Olaf Kirch <okir@monad.swb.de>
- *
- *  TCP callback races fixes (C) 1998 Red Hat Software <alan@redhat.com>
- *  TCP send fixes (C) 1998 Red Hat Software <alan@redhat.com>
- *  TCP NFS related read + write fixes
- *   (C) 1999 Dave Airlie, University of Limerick, Ireland <airlied@linux.ie>
- *
- *  Rewrite of larges part of the code in order to stabilize TCP stuff.
- *  Fix behaviour when socket buffer is full.
- *   (C) 1999 Trond Myklebust <trond.myklebust@fys.uio.no>
  */
 
+#include <linux/module.h>
+
 #include <linux/types.h>
-#include <linux/slab.h>
-#include <linux/capability.h>
-#include <linux/sched.h>
-#include <linux/errno.h>
-#include <linux/socket.h>
-#include <linux/in.h>
-#include <linux/net.h>
-#include <linux/mm.h>
-#include <linux/udp.h>
-#include <linux/tcp.h>
-#include <linux/sunrpc/clnt.h>
-#include <linux/file.h>
+#include <linux/interrupt.h>
 #include <linux/workqueue.h>
 #include <linux/random.h>
 
-#include <net/sock.h>
-#include <net/checksum.h>
-#include <net/udp.h>
-#include <net/tcp.h>
+#include <linux/sunrpc/clnt.h>
 
 /*
  * Local variables
@@ -74,64 +53,17 @@
 #endif
 
 #define XPRT_MAX_BACKOFF        (8)
-#define XPRT_IDLE_TIMEOUT       (5*60*HZ)
-#define XPRT_MAX_RESVPORT       (800)
 
 /*
  * Local functions
  */
 static void     xprt_request_init(struct rpc_task *, struct rpc_xprt *);
 static inline void      do_xprt_reserve(struct rpc_task *);
-static void     xprt_disconnect(struct rpc_xprt *);
 static void     xprt_connect_status(struct rpc_task *task);
-static struct rpc_xprt * xprt_setup(int proto, struct sockaddr_in *ap,
-                                                struct rpc_timeout *to);
-static struct socket *xprt_create_socket(struct rpc_xprt *, int, int);
-static void     xprt_bind_socket(struct rpc_xprt *, struct socket *);
 static int      __xprt_get_cong(struct rpc_xprt *, struct rpc_task *);
 
 static int      xprt_clear_backlog(struct rpc_xprt *xprt);
 
-#ifdef RPC_DEBUG_DATA
-/*
- * Print the buffer contents (first 128 bytes only--just enough for
- * diropres return).
- */
-static void
-xprt_pktdump(char *msg, u32 *packet, unsigned int count)
-{
-        u8      *buf = (u8 *) packet;
-        int     j;
-
-        dprintk("RPC:      %s\n", msg);
-        for (j = 0; j < count && j < 128; j += 4) {
-                if (!(j & 31)) {
-                        if (j)
-                                dprintk("\n");
-                        dprintk("0x%04x ", j);
-                }
-                dprintk("%02x%02x%02x%02x ",
-                        buf[j], buf[j+1], buf[j+2], buf[j+3]);
-        }
-        dprintk("\n");
-}
-#else
-static inline void
-xprt_pktdump(char *msg, u32 *packet, unsigned int count)
-{
-        /* NOP */
-}
-#endif
-
-/*
- * Look up RPC transport given an INET socket
- */
-static inline struct rpc_xprt *
-xprt_from_sock(struct sock *sk)
-{
-        return (struct rpc_xprt *) sk->sk_user_data;
-}
-
 /*
  * Serialize write access to sockets, in order to prevent different
  * requests from interfering with each other.
@@ -235,62 +167,6 @@ xprt_release_write(struct rpc_xprt *xprt, struct rpc_task *task)
 }
 
 /*
- * Write data to socket.
- */
-static inline int
-xprt_sendmsg(struct rpc_xprt *xprt, struct rpc_rqst *req)
-{
-        struct socket   *sock = xprt->sock;
-        struct xdr_buf  *xdr = &req->rq_snd_buf;
-        struct sockaddr *addr = NULL;
-        int addrlen = 0;
-        unsigned int    skip;
-        int             result;
-
-        if (!sock)
-                return -ENOTCONN;
-
-        xprt_pktdump("packet data:",
-                                req->rq_svec->iov_base,
-                                req->rq_svec->iov_len);
-
-        /* For UDP, we need to provide an address */
-        if (!xprt->stream) {
-                addr = (struct sockaddr *) &xprt->addr;
-                addrlen = sizeof(xprt->addr);
-        }
-        /* Dont repeat bytes */
-        skip = req->rq_bytes_sent;
-
-        clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
-        result = xdr_sendpages(sock, addr, addrlen, xdr, skip, MSG_DONTWAIT);
-
-        dprintk("RPC:      xprt_sendmsg(%d) = %d\n", xdr->len - skip, result);
-
-        if (result >= 0)
-                return result;
-
-        switch (result) {
-        case -ECONNREFUSED:
-                /* When the server has died, an ICMP port unreachable message
-                 * prompts ECONNREFUSED.
-                 */
-        case -EAGAIN:
-                break;
-        case -ECONNRESET:
-        case -ENOTCONN:
-        case -EPIPE:
-                /* connection broken */
-                if (xprt->stream)
-                        result = -ENOTCONN;
-                break;
-        default:
-                printk(KERN_NOTICE "RPC: sendmsg returned error %d\n", -result);
-        }
-        return result;
-}
-
-/*
  * Van Jacobson congestion avoidance. Check if the congestion window
  * overflowed. Put the task to sleep if this is the case.
  */
@@ -405,48 +281,20 @@ int xprt_adjust_timeout(struct rpc_rqst *req)
         return status;
 }
 
-/*
- * Close down a transport socket
- */
-static void
-xprt_close(struct rpc_xprt *xprt)
-{
-        struct socket   *sock = xprt->sock;
-        struct sock     *sk = xprt->inet;
-
-        if (!sk)
-                return;
-
-        write_lock_bh(&sk->sk_callback_lock);
-        xprt->inet = NULL;
-        xprt->sock = NULL;
-
-        sk->sk_user_data    = NULL;
-        sk->sk_data_ready   = xprt->old_data_ready;
-        sk->sk_state_change = xprt->old_state_change;
-        sk->sk_write_space  = xprt->old_write_space;
-        write_unlock_bh(&sk->sk_callback_lock);
-
-        sk->sk_no_check  = 0;
-
-        sock_release(sock);
-}
-
 static void
 xprt_socket_autoclose(void *args)
 {
         struct rpc_xprt *xprt = (struct rpc_xprt *)args;
 
         xprt_disconnect(xprt);
-        xprt_close(xprt);
+        xprt->ops->close(xprt);
         xprt_release_write(xprt, NULL);
 }
 
 /*
  * Mark a transport as disconnected
  */
-static void
-xprt_disconnect(struct rpc_xprt *xprt)
+void xprt_disconnect(struct rpc_xprt *xprt)
 {
         dprintk("RPC:      disconnected transport %p\n", xprt);
         spin_lock_bh(&xprt->sock_lock);
@@ -479,57 +327,6 @@ out_abort:
         spin_unlock(&xprt->sock_lock);
 }
 
-static void xprt_socket_connect(void *args)
-{
-        struct rpc_xprt *xprt = (struct rpc_xprt *)args;
-        struct socket *sock = xprt->sock;
-        int status = -EIO;
-
-        if (xprt->shutdown || xprt->addr.sin_port == 0)
-                goto out;
-
-        /*
-         * Start by resetting any existing state
-         */
-        xprt_close(xprt);
-        sock = xprt_create_socket(xprt, xprt->prot, xprt->resvport);
-        if (sock == NULL) {
-                /* couldn't create socket or bind to reserved port;
-                 * this is likely a permanent error, so cause an abort */
-                goto out;
-        }
-        xprt_bind_socket(xprt, sock);
-        xprt_sock_setbufsize(xprt);
-
-        status = 0;
-        if (!xprt->stream)
-                goto out;
-
-        /*
-         * Tell the socket layer to start connecting...
-         */
-        status = sock->ops->connect(sock, (struct sockaddr *) &xprt->addr,
-                        sizeof(xprt->addr), O_NONBLOCK);
-        dprintk("RPC: %p  connect status %d connected %d sock state %d\n",
-                        xprt, -status, xprt_connected(xprt), sock->sk->sk_state);
-        if (status < 0) {
-                switch (status) {
-                        case -EINPROGRESS:
-                        case -EALREADY:
-                                goto out_clear;
-                }
-        }
-out:
-        if (status < 0)
-                rpc_wake_up_status(&xprt->pending, status);
-        else
-                rpc_wake_up(&xprt->pending);
-out_clear:
-        smp_mb__before_clear_bit();
-        clear_bit(XPRT_CONNECTING, &xprt->sockstate);
-        smp_mb__after_clear_bit();
-}
-
 /*
  * Attempt to connect a TCP socket.
  *
@@ -552,30 +349,16 @@ void xprt_connect(struct rpc_task *task)
         if (!xprt_lock_write(xprt, task))
                 return;
         if (xprt_connected(xprt))
-                goto out_write;
+                xprt_release_write(xprt, task);
+        else {
+                if (task->tk_rqstp)
+                        task->tk_rqstp->rq_bytes_sent = 0;
 
-        if (task->tk_rqstp)
-                task->tk_rqstp->rq_bytes_sent = 0;
-
-        task->tk_timeout = RPC_CONNECT_TIMEOUT;
-        rpc_sleep_on(&xprt->pending, task, xprt_connect_status, NULL);
-        if (!test_and_set_bit(XPRT_CONNECTING, &xprt->sockstate)) {
-                /* Note: if we are here due to a dropped connection
-                 *       we delay reconnecting by RPC_REESTABLISH_TIMEOUT/HZ
-                 *       seconds
-                 */
-                if (xprt->sock != NULL)
-                        schedule_delayed_work(&xprt->sock_connect,
-                                        RPC_REESTABLISH_TIMEOUT);
-                else {
-                        schedule_work(&xprt->sock_connect);
-                        if (!RPC_IS_ASYNC(task))
-                                flush_scheduled_work();
-                }
+                task->tk_timeout = RPC_CONNECT_TIMEOUT;
+                rpc_sleep_on(&xprt->pending, task, xprt_connect_status, NULL);
+                xprt->ops->connect(task);
         }
         return;
- out_write:
-        xprt_release_write(xprt, task);
 }
 
 /*
@@ -624,8 +407,7 @@ xprt_connect_status(struct rpc_task *task)
 /*
  * Look up the RPC request corresponding to a reply, and then lock it.
  */
-static inline struct rpc_rqst *
-xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid)
+struct rpc_rqst *xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid)
 {
         struct list_head *pos;
         struct rpc_rqst *req = NULL;
@@ -644,8 +426,7 @@ xprt_lookup_rqst(struct rpc_xprt *xprt, u32 xid)
  * Complete reply received.
  * The TCP code relies on us to remove the request from xprt->pending.
  */
-static void
-xprt_complete_rqst(struct rpc_xprt *xprt, struct rpc_rqst *req, int copied)
+void xprt_complete_rqst(struct rpc_xprt *xprt, struct rpc_rqst *req, int copied)
 {
         struct rpc_task *task = req->rq_task;
         struct rpc_clnt *clnt = task->tk_client;
@@ -692,409 +473,6 @@ xprt_complete_rqst(struct rpc_xprt *xprt, struct rpc_rqst *req, int copied)
 }
 
 /*
- * Input handler for RPC replies. Called from a bottom half and hence
- * atomic.
- */
-static void
-udp_data_ready(struct sock *sk, int len)
-{
-        struct rpc_task *task;
-        struct rpc_xprt *xprt;
-        struct rpc_rqst *rovr;
-        struct sk_buff  *skb;
-        int err, repsize, copied;
-        u32 _xid, *xp;
-
-        read_lock(&sk->sk_callback_lock);
-        dprintk("RPC:      udp_data_ready...\n");
-        if (!(xprt = xprt_from_sock(sk))) {
-                printk("RPC:      udp_data_ready request not found!\n");
-                goto out;
-        }
-
-        dprintk("RPC:      udp_data_ready client %p\n", xprt);
-
-        if ((skb = skb_recv_datagram(sk, 0, 1, &err)) == NULL)
-                goto out;
-
-        if (xprt->shutdown)
-                goto dropit;
-
-        repsize = skb->len - sizeof(struct udphdr);
-        if (repsize < 4) {
-                printk("RPC: impossible RPC reply size %d!\n", repsize);
-                goto dropit;
-        }
-
-        /* Copy the XID from the skb... */
-        xp = skb_header_pointer(skb, sizeof(struct udphdr),
-                                sizeof(_xid), &_xid);
-        if (xp == NULL)
-                goto dropit;
-
-        /* Look up and lock the request corresponding to the given XID */
-        spin_lock(&xprt->sock_lock);
-        rovr = xprt_lookup_rqst(xprt, *xp);
-        if (!rovr)
-                goto out_unlock;
-        task = rovr->rq_task;
-
-        dprintk("RPC: %4d received reply\n", task->tk_pid);
-
-        if ((copied = rovr->rq_private_buf.buflen) > repsize)
-                copied = repsize;
-
-        /* Suck it into the iovec, verify checksum if not done by hw. */
-        if (csum_partial_copy_to_xdr(&rovr->rq_private_buf, skb))
-                goto out_unlock;
-
-        /* Something worked... */
-        dst_confirm(skb->dst);
-
-        xprt_complete_rqst(xprt, rovr, copied);
-
- out_unlock:
-        spin_unlock(&xprt->sock_lock);
- dropit:
-        skb_free_datagram(sk, skb);
- out:
-        read_unlock(&sk->sk_callback_lock);
-}
-
-/*
- * Copy from an skb into memory and shrink the skb.
- */
-static inline size_t
-tcp_copy_data(skb_reader_t *desc, void *p, size_t len)
-{
-        if (len > desc->count)
-                len = desc->count;
-        if (skb_copy_bits(desc->skb, desc->offset, p, len)) {
-                dprintk("RPC:      failed to copy %zu bytes from skb. %zu bytes remain\n",
-                                len, desc->count);
-                return 0;
-        }
-        desc->offset += len;
-        desc->count -= len;
-        dprintk("RPC:      copied %zu bytes from skb. %zu bytes remain\n",
-                        len, desc->count);
-        return len;
-}
-
-/*
- * TCP read fragment marker
- */
-static inline void
-tcp_read_fraghdr(struct rpc_xprt *xprt, skb_reader_t *desc)
-{
-        size_t len, used;
-        char *p;
-
-        p = ((char *) &xprt->tcp_recm) + xprt->tcp_offset;
-        len = sizeof(xprt->tcp_recm) - xprt->tcp_offset;
-        used = tcp_copy_data(desc, p, len);
-        xprt->tcp_offset += used;
-        if (used != len)
-                return;
-        xprt->tcp_reclen = ntohl(xprt->tcp_recm);
-        if (xprt->tcp_reclen & 0x80000000)
-                xprt->tcp_flags |= XPRT_LAST_FRAG;
-        else
-                xprt->tcp_flags &= ~XPRT_LAST_FRAG;
-        xprt->tcp_reclen &= 0x7fffffff;
-        xprt->tcp_flags &= ~XPRT_COPY_RECM;
-        xprt->tcp_offset = 0;
-        /* Sanity check of the record length */
-        if (xprt->tcp_reclen < 4) {
-                printk(KERN_ERR "RPC: Invalid TCP record fragment length\n");
-                xprt_disconnect(xprt);
-        }
-        dprintk("RPC:      reading TCP record fragment of length %d\n",
-                        xprt->tcp_reclen);
-}
-
-static void
-tcp_check_recm(struct rpc_xprt *xprt)
-{
-        dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u, tcp_flags = %lx\n",
-                        xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen, xprt->tcp_flags);
-        if (xprt->tcp_offset == xprt->tcp_reclen) {
-                xprt->tcp_flags |= XPRT_COPY_RECM;
-                xprt->tcp_offset = 0;
-                if (xprt->tcp_flags & XPRT_LAST_FRAG) {
-                        xprt->tcp_flags &= ~XPRT_COPY_DATA;
-                        xprt->tcp_flags |= XPRT_COPY_XID;
-                        xprt->tcp_copied = 0;
-                }
-        }
-}
-
-/*
- * TCP read xid
- */
-static inline void
-tcp_read_xid(struct rpc_xprt *xprt, skb_reader_t *desc)
-{
-        size_t len, used;
-        char *p;
-
-        len = sizeof(xprt->tcp_xid) - xprt->tcp_offset;
-        dprintk("RPC:      reading XID (%Zu bytes)\n", len);
-        p = ((char *) &xprt->tcp_xid) + xprt->tcp_offset;
-        used = tcp_copy_data(desc, p, len);
-        xprt->tcp_offset += used;
-        if (used != len)
-                return;
-        xprt->tcp_flags &= ~XPRT_COPY_XID;
-        xprt->tcp_flags |= XPRT_COPY_DATA;
-        xprt->tcp_copied = 4;
-        dprintk("RPC:      reading reply for XID %08x\n",
-                                                ntohl(xprt->tcp_xid));
-        tcp_check_recm(xprt);
-}
-
-/*
- * TCP read and complete request
- */
-static inline void
-tcp_read_request(struct rpc_xprt *xprt, skb_reader_t *desc)
-{
-        struct rpc_rqst *req;
-        struct xdr_buf *rcvbuf;
-        size_t len;
-        ssize_t r;
-
-        /* Find and lock the request corresponding to this xid */
-        spin_lock(&xprt->sock_lock);
-        req = xprt_lookup_rqst(xprt, xprt->tcp_xid);
-        if (!req) {
-                xprt->tcp_flags &= ~XPRT_COPY_DATA;
-                dprintk("RPC:      XID %08x request not found!\n",
-                                ntohl(xprt->tcp_xid));
-                spin_unlock(&xprt->sock_lock);
-                return;
-        }
-
-        rcvbuf = &req->rq_private_buf;
-        len = desc->count;
-        if (len > xprt->tcp_reclen - xprt->tcp_offset) {
-                skb_reader_t my_desc;
-
-                len = xprt->tcp_reclen - xprt->tcp_offset;
-                memcpy(&my_desc, desc, sizeof(my_desc));
-                my_desc.count = len;
-                r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
-                                          &my_desc, tcp_copy_data);
-                desc->count -= r;
-                desc->offset += r;
-        } else
-                r = xdr_partial_copy_from_skb(rcvbuf, xprt->tcp_copied,
-                                          desc, tcp_copy_data);
-
-        if (r > 0) {
-                xprt->tcp_copied += r;
-                xprt->tcp_offset += r;
-        }
-        if (r != len) {
-                /* Error when copying to the receive buffer,
-                 * usually because we weren't able to allocate
-                 * additional buffer pages. All we can do now
-                 * is turn off XPRT_COPY_DATA, so the request
-                 * will not receive any additional updates,
-                 * and time out.
-                 * Any remaining data from this record will
-                 * be discarded.
-                 */
-                xprt->tcp_flags &= ~XPRT_COPY_DATA;
-                dprintk("RPC:      XID %08x truncated request\n",
-                                ntohl(xprt->tcp_xid));
-                dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
-                                xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
-                goto out;
-        }
-
-        dprintk("RPC:      XID %08x read %Zd bytes\n",
-                        ntohl(xprt->tcp_xid), r);
-        dprintk("RPC:      xprt = %p, tcp_copied = %lu, tcp_offset = %u, tcp_reclen = %u\n",
-                        xprt, xprt->tcp_copied, xprt->tcp_offset, xprt->tcp_reclen);
-
-        if (xprt->tcp_copied == req->rq_private_buf.buflen)
-                xprt->tcp_flags &= ~XPRT_COPY_DATA;
-        else if (xprt->tcp_offset == xprt->tcp_reclen) {
-                if (xprt->tcp_flags & XPRT_LAST_FRAG)
-                        xprt->tcp_flags &= ~XPRT_COPY_DATA;
-        }
-
-out:
-        if (!(xprt->tcp_flags & XPRT_COPY_DATA)) {
-                dprintk("RPC: %4d received reply complete\n",
-                                req->rq_task->tk_pid);
-                xprt_complete_rqst(xprt, req, xprt->tcp_copied);
-        }
-        spin_unlock(&xprt->sock_lock);
-        tcp_check_recm(xprt);
-}
-
-/*
- * TCP discard extra bytes from a short read
- */
-static inline void
-tcp_read_discard(struct rpc_xprt *xprt, skb_reader_t *desc)
-{
-        size_t len;
-
-        len = xprt->tcp_reclen - xprt->tcp_offset;
-        if (len > desc->count)
-                len = desc->count;
-        desc->count -= len;
-        desc->offset += len;
-        xprt->tcp_offset += len;
-        dprintk("RPC:      discarded %Zu bytes\n", len);
-        tcp_check_recm(xprt);
-}
-
-/*
- * TCP record receive routine
- * We first have to grab the record marker, then the XID, then the data.
- */
-static int
-tcp_data_recv(read_descriptor_t *rd_desc, struct sk_buff *skb,
-                unsigned int offset, size_t len)
-{
-        struct rpc_xprt *xprt = rd_desc->arg.data;
-        skb_reader_t desc = {
-                .skb    = skb,
-                .offset = offset,
-                .count  = len,
-                .csum   = 0
-        };
-
-        dprintk("RPC:      tcp_data_recv\n");
-        do {
-                /* Read in a new fragment marker if necessary */
-                /* Can we ever really expect to get completely empty fragments? */
-                if (xprt->tcp_flags & XPRT_COPY_RECM) {
-                        tcp_read_fraghdr(xprt, &desc);
-                        continue;
-                }
-                /* Read in the xid if necessary */
-                if (xprt->tcp_flags & XPRT_COPY_XID) {
-                        tcp_read_xid(xprt, &desc);
-                        continue;
-                }
-                /* Read in the request data */
-                if (xprt->tcp_flags & XPRT_COPY_DATA) {
-                        tcp_read_request(xprt, &desc);
-                        continue;
-                }
-                /* Skip over any trailing bytes on short reads */
-                tcp_read_discard(xprt, &desc);
-        } while (desc.count);
-        dprintk("RPC:      tcp_data_recv done\n");
-        return len - desc.count;
-}
-
-static void tcp_data_ready(struct sock *sk, int bytes)
-{
-        struct rpc_xprt *xprt;
-        read_descriptor_t rd_desc;
-
-        read_lock(&sk->sk_callback_lock);
-        dprintk("RPC:      tcp_data_ready...\n");
-        if (!(xprt = xprt_from_sock(sk))) {
-                printk("RPC:      tcp_data_ready socket info not found!\n");
-                goto out;
-        }
-        if (xprt->shutdown)
-                goto out;
-
-        /* We use rd_desc to pass struct xprt to tcp_data_recv */
-        rd_desc.arg.data = xprt;
-        rd_desc.count = 65536;
-        tcp_read_sock(sk, &rd_desc, tcp_data_recv);
-out:
-        read_unlock(&sk->sk_callback_lock);
-}
-
-static void
-tcp_state_change(struct sock *sk)
-{
-        struct rpc_xprt *xprt;
-
-        read_lock(&sk->sk_callback_lock);
-        if (!(xprt = xprt_from_sock(sk)))
-                goto out;
-        dprintk("RPC:      tcp_state_change client %p...\n", xprt);
-        dprintk("RPC:      state %x conn %d dead %d zapped %d\n",
-                                sk->sk_state, xprt_connected(xprt),
-                                sock_flag(sk, SOCK_DEAD),
-                                sock_flag(sk, SOCK_ZAPPED));
-
-        switch (sk->sk_state) {
-        case TCP_ESTABLISHED:
-                spin_lock_bh(&xprt->sock_lock);
-                if (!xprt_test_and_set_connected(xprt)) {
-                        /* Reset TCP record info */
-                        xprt->tcp_offset = 0;
-                        xprt->tcp_reclen = 0;
-                        xprt->tcp_copied = 0;
-                        xprt->tcp_flags = XPRT_COPY_RECM | XPRT_COPY_XID;
-                        rpc_wake_up(&xprt->pending);
-                }
-                spin_unlock_bh(&xprt->sock_lock);
-                break;
-        case TCP_SYN_SENT:
-        case TCP_SYN_RECV:
-                break;
-        default:
-                xprt_disconnect(xprt);
-                break;
-        }
- out:
-        read_unlock(&sk->sk_callback_lock);
-}
-
-/*
- * Called when more output buffer space is available for this socket.
- * We try not to wake our writers until they can make "significant"
- * progress, otherwise we'll waste resources thrashing sock_sendmsg
- * with a bunch of small requests.
- */
-static void
-xprt_write_space(struct sock *sk)
-{
-        struct rpc_xprt *xprt;
-        struct socket   *sock;
-
-        read_lock(&sk->sk_callback_lock);
-        if (!(xprt = xprt_from_sock(sk)) || !(sock = sk->sk_socket))
-                goto out;
-        if (xprt->shutdown)
-                goto out;
-
-        /* Wait until we have enough socket memory */
-        if (xprt->stream) {
-                /* from net/core/stream.c:sk_stream_write_space */
-                if (sk_stream_wspace(sk) < sk_stream_min_wspace(sk))
-                        goto out;
-        } else {
-                /* from net/core/sock.c:sock_def_write_space */
-                if (!sock_writeable(sk))
-                        goto out;
-        }
-
-        if (!test_and_clear_bit(SOCK_NOSPACE, &sock->flags))
-                goto out;
-
-        spin_lock_bh(&xprt->sock_lock);
-        if (xprt->snd_task)
-                rpc_wake_up_task(xprt->snd_task);
-        spin_unlock_bh(&xprt->sock_lock);
-out:
-        read_unlock(&sk->sk_callback_lock);
-}
-
-/*
  * RPC receive timeout handler.
  */
 static void
@@ -1161,19 +539,10 @@ xprt_transmit(struct rpc_task *task)
         struct rpc_clnt *clnt = task->tk_client;
         struct rpc_rqst *req = task->tk_rqstp;
         struct rpc_xprt *xprt = req->rq_xprt;
-        int status, retry = 0;
-
+        int status;
 
         dprintk("RPC: %4d xprt_transmit(%u)\n", task->tk_pid, req->rq_slen);
 
-        /* set up everything as needed. */
-        /* Write the record marker */
-        if (xprt->stream) {
-                u32     *marker = req->rq_svec[0].iov_base;
-
-                *marker = htonl(0x80000000|(req->rq_slen-sizeof(*marker)));
-        }
-
         smp_rmb();
         if (!req->rq_received) {
                 if (list_empty(&req->rq_list)) {
@@ -1191,41 +560,9 @@ xprt_transmit(struct rpc_task *task)
         } else if (!req->rq_bytes_sent)
                 return;
 
-        /* Continue transmitting the packet/record. We must be careful
-         * to cope with writespace callbacks arriving _after_ we have
-         * called xprt_sendmsg().
-         */
-        while (1) {
-                req->rq_xtime = jiffies;
-                status = xprt_sendmsg(xprt, req);
-
-                if (status < 0)
-                        break;
-
-                if (xprt->stream) {
-                        req->rq_bytes_sent += status;
-
-                        /* If we've sent the entire packet, immediately
-                         * reset the count of bytes sent. */
-                        if (req->rq_bytes_sent >= req->rq_slen) {
-                                req->rq_bytes_sent = 0;
-                                goto out_receive;
-                        }
-                } else {
-                        if (status >= req->rq_slen)
-                                goto out_receive;
-                        status = -EAGAIN;
-                        break;
-                }
-
-                dprintk("RPC: %4d xmit incomplete (%d left of %d)\n",
-                                task->tk_pid, req->rq_slen - req->rq_bytes_sent,
-                                req->rq_slen);
-
-                status = -EAGAIN;
-                if (retry++ > 50)
-                        break;
-        }
+        status = xprt->ops->send_request(task);
+        if (!status)
+                goto out_receive;
 
         /* Note: at this point, task->tk_sleeping has not yet been set,
          *       hence there is no danger of the waking up task being put on
@@ -1234,26 +571,10 @@ xprt_transmit(struct rpc_task *task)
         task->tk_status = status;
 
         switch (status) {
-        case -EAGAIN:
-                if (test_bit(SOCK_ASYNC_NOSPACE, &xprt->sock->flags)) {
-                        /* Protect against races with xprt_write_space */
-                        spin_lock_bh(&xprt->sock_lock);
-                        /* Don't race with disconnect */
-                        if (!xprt_connected(xprt))
-                                task->tk_status = -ENOTCONN;
-                        else if (test_bit(SOCK_NOSPACE, &xprt->sock->flags)) {
-                                task->tk_timeout = req->rq_timeout;
-                                rpc_sleep_on(&xprt->pending, task, NULL, NULL);
-                        }
-                        spin_unlock_bh(&xprt->sock_lock);
-                        return;
-                }
-                /* Keep holding the socket if it is blocked */
-                rpc_delay(task, HZ>>4);
-                return;
         case -ECONNREFUSED:
                 task->tk_timeout = RPC_REESTABLISH_TIMEOUT;
                 rpc_sleep_on(&xprt->sending, task, NULL, NULL);
+        case -EAGAIN:
         case -ENOTCONN:
                 return;
         default:
@@ -1367,7 +688,8 @@ xprt_release(struct rpc_task *task)
                 list_del(&req->rq_list);
         xprt->last_used = jiffies;
         if (list_empty(&xprt->recv) && !xprt->shutdown)
-                mod_timer(&xprt->timer, xprt->last_used + XPRT_IDLE_TIMEOUT);
+                mod_timer(&xprt->timer,
+                                xprt->last_used + RPC_IDLE_DISCONNECT_TIMEOUT);
         spin_unlock_bh(&xprt->sock_lock);
         task->tk_rqstp = NULL;
         memset(req, 0, sizeof(*req));   /* mark unused */
@@ -1381,18 +703,6 @@ xprt_release(struct rpc_task *task)
 }
 
 /*
- * Set default timeout parameters
- */
-static void
-xprt_default_timeout(struct rpc_timeout *to, int proto)
-{
-        if (proto == IPPROTO_UDP)
-                xprt_set_timeout(to, 5,  5 * HZ);
-        else
-                xprt_set_timeout(to, 2, 60 * HZ);
-}
-
-/*
  * Set constant timeout
  */
 void
@@ -1405,68 +715,51 @@ xprt_set_timeout(struct rpc_timeout *to, unsigned int retr, unsigned long incr)
         to->to_exponential = 0;
 }
 
-unsigned int xprt_udp_slot_table_entries = RPC_DEF_SLOT_TABLE;
-unsigned int xprt_tcp_slot_table_entries = RPC_DEF_SLOT_TABLE;
-
 /*
  * Initialize an RPC client
  */
 static struct rpc_xprt *
 xprt_setup(int proto, struct sockaddr_in *ap, struct rpc_timeout *to)
 {
+        int result;
         struct rpc_xprt *xprt;
-        unsigned int entries;
-        size_t slot_table_size;
         struct rpc_rqst *req;
 
-        dprintk("RPC:      setting up %s transport...\n",
-                                proto == IPPROTO_UDP? "UDP" : "TCP");
-
-        entries = (proto == IPPROTO_TCP)?
-                xprt_tcp_slot_table_entries : xprt_udp_slot_table_entries;
-
         if ((xprt = kmalloc(sizeof(struct rpc_xprt), GFP_KERNEL)) == NULL)
                 return ERR_PTR(-ENOMEM);
         memset(xprt, 0, sizeof(*xprt)); /* Nnnngh! */
-        xprt->max_reqs = entries;
-        slot_table_size = entries * sizeof(xprt->slot[0]);
-        xprt->slot = kmalloc(slot_table_size, GFP_KERNEL);
-        if (xprt->slot == NULL) {
-                kfree(xprt);
-                return ERR_PTR(-ENOMEM);
-        }
-        memset(xprt->slot, 0, slot_table_size);
 
         xprt->addr = *ap;
-        xprt->prot = proto;
-        xprt->stream = (proto == IPPROTO_TCP)? 1 : 0;
-        if (xprt->stream) {
-                xprt->cwnd = RPC_MAXCWND(xprt);
-                xprt->nocong = 1;
-                xprt->max_payload = (1U << 31) - 1;
-        } else {
-                xprt->cwnd = RPC_INITCWND;
-                xprt->max_payload = (1U << 16) - (MAX_HEADER << 3);
+
+        switch (proto) {
+        case IPPROTO_UDP:
+                result = xs_setup_udp(xprt, to);
+                break;
+        case IPPROTO_TCP:
+                result = xs_setup_tcp(xprt, to);
+                break;
+        default:
+                printk(KERN_ERR "RPC: unrecognized transport protocol: %d\n",
+                                proto);
+                result = -EIO;
+                break;
+        }
+        if (result) {
+                kfree(xprt);
+                return ERR_PTR(result);
         }
+
         spin_lock_init(&xprt->sock_lock);
         spin_lock_init(&xprt->xprt_lock);
         init_waitqueue_head(&xprt->cong_wait);
 
         INIT_LIST_HEAD(&xprt->free);
         INIT_LIST_HEAD(&xprt->recv);
-        INIT_WORK(&xprt->sock_connect, xprt_socket_connect, xprt);
         INIT_WORK(&xprt->task_cleanup, xprt_socket_autoclose, xprt);
         init_timer(&xprt->timer);
         xprt->timer.function = xprt_init_autodisconnect;
         xprt->timer.data = (unsigned long) xprt;
         xprt->last_used = jiffies;
-        xprt->port = XPRT_MAX_RESVPORT;
-
-        /* Set timeout parameters */
-        if (to) {
-                xprt->timeout = *to;
-        } else
-                xprt_default_timeout(&xprt->timeout, xprt->prot);
 
         rpc_init_wait_queue(&xprt->pending, "xprt_pending");
         rpc_init_wait_queue(&xprt->sending, "xprt_sending");
@@ -1474,14 +767,11 @@ xprt_setup(int proto, struct sockaddr_in *ap, struct rpc_timeout *to)
         rpc_init_priority_wait_queue(&xprt->backlog, "xprt_backlog");
 
         /* initialize free list */
-        for (req = &xprt->slot[entries-1]; req >= &xprt->slot[0]; req--)
+        for (req = &xprt->slot[xprt->max_reqs-1]; req >= &xprt->slot[0]; req--)
                 list_add(&req->rq_list, &xprt->free);
 
         xprt_init_xid(xprt);
 
-        /* Check whether we want to use a reserved port */
-        xprt->resvport = capable(CAP_NET_BIND_SERVICE) ? 1 : 0;
-
         dprintk("RPC:      created transport %p with %u slots\n", xprt,
                         xprt->max_reqs);
         
@@ -1489,120 +779,6 @@ xprt_setup(int proto, struct sockaddr_in *ap, struct rpc_timeout *to)
 }
 
 /*
- * Bind to a reserved port
- */
-static inline int xprt_bindresvport(struct rpc_xprt *xprt, struct socket *sock)
-{
-        struct sockaddr_in myaddr = {
-                .sin_family = AF_INET,
-        };
-        int             err, port;
-
-        /* Were we already bound to a given port? Try to reuse it */
-        port = xprt->port;
-        do {
-                myaddr.sin_port = htons(port);
-                err = sock->ops->bind(sock, (struct sockaddr *) &myaddr,
-                                                sizeof(myaddr));
-                if (err == 0) {
-                        xprt->port = port;
-                        return 0;
-                }
-                if (--port == 0)
-                        port = XPRT_MAX_RESVPORT;
-        } while (err == -EADDRINUSE && port != xprt->port);
-
-        printk("RPC: Can't bind to reserved port (%d).\n", -err);
-        return err;
-}
-
-static void
-xprt_bind_socket(struct rpc_xprt *xprt, struct socket *sock)
-{
-        struct sock     *sk = sock->sk;
-
-        if (xprt->inet)
-                return;
-
-        write_lock_bh(&sk->sk_callback_lock);
-        sk->sk_user_data = xprt;
-        xprt->old_data_ready = sk->sk_data_ready;
-        xprt->old_state_change = sk->sk_state_change;
-        xprt->old_write_space = sk->sk_write_space;
-        if (xprt->prot == IPPROTO_UDP) {
-                sk->sk_data_ready = udp_data_ready;
-                sk->sk_no_check = UDP_CSUM_NORCV;
-                xprt_set_connected(xprt);
-        } else {
-                tcp_sk(sk)->nonagle = 1;        /* disable Nagle's algorithm */
-                sk->sk_data_ready = tcp_data_ready;
-                sk->sk_state_change = tcp_state_change;
-                xprt_clear_connected(xprt);
-        }
-        sk->sk_write_space = xprt_write_space;
-
-        /* Reset to new socket */
-        xprt->sock = sock;
-        xprt->inet = sk;
-        write_unlock_bh(&sk->sk_callback_lock);
-
-        return;
-}
-
-/*
- * Set socket buffer length
- */
-void
-xprt_sock_setbufsize(struct rpc_xprt *xprt)
-{
-        struct sock *sk = xprt->inet;
-
-        if (xprt->stream)
-                return;
-        if (xprt->rcvsize) {
-                sk->sk_userlocks |= SOCK_RCVBUF_LOCK;
-                sk->sk_rcvbuf = xprt->rcvsize * xprt->max_reqs *  2;
-        }
-        if (xprt->sndsize) {
-                sk->sk_userlocks |= SOCK_SNDBUF_LOCK;
-                sk->sk_sndbuf = xprt->sndsize * xprt->max_reqs * 2;
-                sk->sk_write_space(sk);
-        }
-}
-
-/*
- * Datastream sockets are created here, but xprt_connect will create
- * and connect stream sockets.
- */
-static struct socket * xprt_create_socket(struct rpc_xprt *xprt, int proto, int resvport)
-{
-        struct socket   *sock;
-        int             type, err;
-
-        dprintk("RPC:      xprt_create_socket(%s %d)\n",
-                           (proto == IPPROTO_UDP)? "udp" : "tcp", proto);
-
-        type = (proto == IPPROTO_UDP)? SOCK_DGRAM : SOCK_STREAM;
-
-        if ((err = sock_create_kern(PF_INET, type, proto, &sock)) < 0) {
-                printk("RPC: can't create socket (%d).\n", -err);
-                return NULL;
-        }
-
-        /* If the caller has the capability, bind to a reserved port */
-        if (resvport && xprt_bindresvport(xprt, sock) < 0) {
-                printk("RPC: can't bind to reserved port.\n");
-                goto failed;
-        }
-
-        return sock;
-
-failed:
-        sock_release(sock);
-        return NULL;
-}
-
-/*
  * Create an RPC client transport given the protocol and peer address.
  */
 struct rpc_xprt *
@@ -1631,10 +807,6 @@ xprt_shutdown(struct rpc_xprt *xprt)
         rpc_wake_up(&xprt->backlog);
         wake_up(&xprt->cong_wait);
         del_timer_sync(&xprt->timer);
-
-        /* synchronously wait for connect worker to finish */
-        cancel_delayed_work(&xprt->sock_connect);
-        flush_scheduled_work();
 }
 
 /*
@@ -1655,9 +827,7 @@ xprt_destroy(struct rpc_xprt *xprt)
 {
         dprintk("RPC:      destroying transport %p\n", xprt);
         xprt_shutdown(xprt);
-        xprt_disconnect(xprt);
-        xprt_close(xprt);
-        kfree(xprt->slot);
+        xprt->ops->destroy(xprt);
         kfree(xprt);
 
         return 0;