forked from Minki/linux
[PATCH] RPC: separate TCP and UDP socket write paths
Split the RPC client's main socket write path into a TCP version and a UDP version to eliminate another dependency on the "xprt->stream" variable. Compiler optimization removes unneeded code from xs_sendpages, as this function is now called with some constant arguments. We can now cleanly perform transport protocol-specific return code testing and error recovery in each path. Test-plan: Millions of fsx operations. Performance characterization such as "sio" or "iozone". Examine oprofile results for any changes before and after this patch is applied. Version: Thu, 11 Aug 2005 16:08:46 -0400 Signed-off-by: Chuck Lever <cel@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever
Trond Myklebust
parent
b0d93ad511
commit
262965f53d
@ -40,6 +40,12 @@
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*/
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#define XS_MAX_RESVPORT (800U)
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/*
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* How many times to try sending a request on a socket before waiting
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* for the socket buffer to clear.
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*/
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#define XS_SENDMSG_RETRY (10U)
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#ifdef RPC_DEBUG
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# undef RPC_DEBUG_DATA
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# define RPCDBG_FACILITY RPCDBG_TRANS
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@ -114,13 +120,18 @@ static int xs_send_tail(struct socket *sock, struct xdr_buf *xdr, unsigned int b
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* @base: starting position in the buffer
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*
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*/
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static int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
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static inline int xs_sendpages(struct socket *sock, struct sockaddr *addr, int addrlen, struct xdr_buf *xdr, unsigned int base)
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{
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struct page **ppage = xdr->pages;
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unsigned int len, pglen = xdr->page_len;
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int err, ret = 0;
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ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
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if (unlikely(!sock))
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return -ENOTCONN;
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clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
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len = xdr->head[0].iov_len;
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if (base < len || (addr != NULL && base == 0)) {
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err = xs_send_head(sock, addr, addrlen, xdr, base, len);
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@ -187,140 +198,162 @@ out:
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}
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/**
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* xs_sendmsg - write an RPC request to a socket
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* @xprt: generic transport
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* @req: the RPC request to write
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* xs_nospace - place task on wait queue if transmit was incomplete
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* @task: task to put to sleep
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*
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*/
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static int xs_sendmsg(struct rpc_xprt *xprt, struct rpc_rqst *req)
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static void xs_nospace(struct rpc_task *task)
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{
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struct socket *sock = xprt->sock;
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struct xdr_buf *xdr = &req->rq_snd_buf;
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struct sockaddr *addr = NULL;
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int addrlen = 0;
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unsigned int skip;
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int result;
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struct rpc_rqst *req = task->tk_rqstp;
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struct rpc_xprt *xprt = req->rq_xprt;
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if (!sock)
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return -ENOTCONN;
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dprintk("RPC: %4d xmit incomplete (%u left of %u)\n",
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task->tk_pid, req->rq_slen - req->rq_bytes_sent,
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req->rq_slen);
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if (test_bit(SOCK_ASYNC_NOSPACE, &xprt->sock->flags)) {
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/* Protect against races with write_space */
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spin_lock_bh(&xprt->transport_lock);
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/* Don't race with disconnect */
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if (!xprt_connected(xprt))
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task->tk_status = -ENOTCONN;
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else if (test_bit(SOCK_NOSPACE, &xprt->sock->flags))
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xprt_wait_for_buffer_space(task);
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spin_unlock_bh(&xprt->transport_lock);
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} else
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/* Keep holding the socket if it is blocked */
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rpc_delay(task, HZ>>4);
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}
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/**
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* xs_udp_send_request - write an RPC request to a UDP socket
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* @task: address of RPC task that manages the state of an RPC request
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*
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* Return values:
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* 0: The request has been sent
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* EAGAIN: The socket was blocked, please call again later to
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* complete the request
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* ENOTCONN: Caller needs to invoke connect logic then call again
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* other: Some other error occured, the request was not sent
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*/
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static int xs_udp_send_request(struct rpc_task *task)
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{
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struct rpc_rqst *req = task->tk_rqstp;
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struct rpc_xprt *xprt = req->rq_xprt;
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struct xdr_buf *xdr = &req->rq_snd_buf;
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int status;
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xs_pktdump("packet data:",
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req->rq_svec->iov_base,
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req->rq_svec->iov_len);
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/* For UDP, we need to provide an address */
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if (!xprt->stream) {
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addr = (struct sockaddr *) &xprt->addr;
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addrlen = sizeof(xprt->addr);
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}
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/* Don't repeat bytes */
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skip = req->rq_bytes_sent;
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req->rq_xtime = jiffies;
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status = xs_sendpages(xprt->sock, (struct sockaddr *) &xprt->addr,
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sizeof(xprt->addr), xdr, req->rq_bytes_sent);
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clear_bit(SOCK_ASYNC_NOSPACE, &sock->flags);
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result = xs_sendpages(sock, addr, addrlen, xdr, skip);
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dprintk("RPC: xs_udp_send_request(%u) = %d\n",
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xdr->len - req->rq_bytes_sent, status);
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dprintk("RPC: xs_sendmsg(%d) = %d\n", xdr->len - skip, result);
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if (likely(status >= (int) req->rq_slen))
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return 0;
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if (result >= 0)
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return result;
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/* Still some bytes left; set up for a retry later. */
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if (status > 0)
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status = -EAGAIN;
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switch (result) {
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switch (status) {
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case -ENETUNREACH:
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case -EPIPE:
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case -ECONNREFUSED:
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/* When the server has died, an ICMP port unreachable message
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* prompts ECONNREFUSED. */
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case -EAGAIN:
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break;
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case -ECONNRESET:
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case -ENOTCONN:
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case -EPIPE:
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/* connection broken */
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if (xprt->stream)
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result = -ENOTCONN;
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case -EAGAIN:
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xs_nospace(task);
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break;
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default:
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dprintk("RPC: sendmsg returned unrecognized error %d\n",
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-status);
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break;
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}
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return result;
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return status;
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}
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/**
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* xs_send_request - write an RPC request to a socket
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* xs_tcp_send_request - write an RPC request to a TCP socket
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* @task: address of RPC task that manages the state of an RPC request
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*
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* Return values:
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* 0: The request has been sent
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* EAGAIN: The socket was blocked, please call again later to
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* complete the request
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* other: Some other error occured, the request was not sent
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* 0: The request has been sent
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* EAGAIN: The socket was blocked, please call again later to
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* complete the request
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* ENOTCONN: Caller needs to invoke connect logic then call again
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* other: Some other error occured, the request was not sent
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*
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* XXX: In the case of soft timeouts, should we eventually give up
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* if the socket is not able to make progress?
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* if sendmsg is not able to make progress?
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*/
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static int xs_send_request(struct rpc_task *task)
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static int xs_tcp_send_request(struct rpc_task *task)
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{
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struct rpc_rqst *req = task->tk_rqstp;
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struct rpc_xprt *xprt = req->rq_xprt;
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struct xdr_buf *xdr = &req->rq_snd_buf;
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u32 *marker = req->rq_svec[0].iov_base;
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int status, retry = 0;
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/* set up everything as needed. */
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/* Write the record marker */
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if (xprt->stream) {
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u32 *marker = req->rq_svec[0].iov_base;
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*marker = htonl(0x80000000|(req->rq_slen-sizeof(*marker)));
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*marker = htonl(0x80000000|(req->rq_slen-sizeof(*marker)));
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}
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xs_pktdump("packet data:",
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req->rq_svec->iov_base,
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req->rq_svec->iov_len);
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/* Continue transmitting the packet/record. We must be careful
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* to cope with writespace callbacks arriving _after_ we have
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* called sendmsg().
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*/
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* called sendmsg(). */
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while (1) {
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req->rq_xtime = jiffies;
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status = xs_sendmsg(xprt, req);
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status = xs_sendpages(xprt->sock, NULL, 0, xdr,
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req->rq_bytes_sent);
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if (status < 0)
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dprintk("RPC: xs_tcp_send_request(%u) = %d\n",
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xdr->len - req->rq_bytes_sent, status);
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if (unlikely(status < 0))
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break;
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if (xprt->stream) {
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req->rq_bytes_sent += status;
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/* If we've sent the entire packet, immediately
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* reset the count of bytes sent. */
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if (req->rq_bytes_sent >= req->rq_slen) {
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req->rq_bytes_sent = 0;
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return 0;
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}
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} else {
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if (status >= req->rq_slen)
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return 0;
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status = -EAGAIN;
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break;
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/* If we've sent the entire packet, immediately
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* reset the count of bytes sent. */
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req->rq_bytes_sent += status;
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if (likely(req->rq_bytes_sent >= req->rq_slen)) {
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req->rq_bytes_sent = 0;
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return 0;
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}
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dprintk("RPC: %4d xmit incomplete (%d left of %d)\n",
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task->tk_pid, req->rq_slen - req->rq_bytes_sent,
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req->rq_slen);
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status = -EAGAIN;
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if (retry++ > 50)
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if (retry++ > XS_SENDMSG_RETRY)
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break;
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}
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if (status == -EAGAIN) {
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if (test_bit(SOCK_ASYNC_NOSPACE, &xprt->sock->flags)) {
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/* Protect against races with write_space */
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spin_lock_bh(&xprt->transport_lock);
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/* Don't race with disconnect */
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if (!xprt_connected(xprt))
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task->tk_status = -ENOTCONN;
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else if (test_bit(SOCK_NOSPACE, &xprt->sock->flags))
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xprt_wait_for_buffer_space(task);
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spin_unlock_bh(&xprt->transport_lock);
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return status;
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}
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/* Keep holding the socket if it is blocked */
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rpc_delay(task, HZ>>4);
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switch (status) {
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case -EAGAIN:
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xs_nospace(task);
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break;
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case -ECONNREFUSED:
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case -ECONNRESET:
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case -ENOTCONN:
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case -EPIPE:
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status = -ENOTCONN;
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break;
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default:
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dprintk("RPC: sendmsg returned unrecognized error %d\n",
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-status);
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break;
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}
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return status;
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}
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@ -992,10 +1025,18 @@ static void xs_connect(struct rpc_task *task)
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}
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}
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static struct rpc_xprt_ops xs_ops = {
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static struct rpc_xprt_ops xs_udp_ops = {
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.set_buffer_size = xs_set_buffer_size,
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.connect = xs_connect,
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.send_request = xs_send_request,
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.send_request = xs_udp_send_request,
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.close = xs_close,
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.destroy = xs_destroy,
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};
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static struct rpc_xprt_ops xs_tcp_ops = {
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.set_buffer_size = xs_set_buffer_size,
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.connect = xs_connect,
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.send_request = xs_tcp_send_request,
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.close = xs_close,
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.destroy = xs_destroy,
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};
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@ -1033,7 +1074,7 @@ int xs_setup_udp(struct rpc_xprt *xprt, struct rpc_timeout *to)
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INIT_WORK(&xprt->connect_worker, xs_udp_connect_worker, xprt);
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xprt->ops = &xs_ops;
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xprt->ops = &xs_udp_ops;
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if (to)
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xprt->timeout = *to;
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@ -1072,7 +1113,7 @@ int xs_setup_tcp(struct rpc_xprt *xprt, struct rpc_timeout *to)
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INIT_WORK(&xprt->connect_worker, xs_tcp_connect_worker, xprt);
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xprt->ops = &xs_ops;
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xprt->ops = &xs_tcp_ops;
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if (to)
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xprt->timeout = *to;
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