From 2ea24497a1b30dd03dd42b873fa5097913587f4d Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Mon, 10 Feb 2014 11:18:39 -0500 Subject: SUNRPC: RPC callbacks may be split across several TCP segments Since TCP is a stream protocol, our callback read code needs to take into account the fact that RPC callbacks are not always confined to a single TCP segment. This patch adds support for multiple TCP segments by ensuring that we only remove the rpc_rqst structure from the 'free backchannel requests' list once the data has been completely received. We rely on the fact that TCP data is ordered for the duration of the connection. Reported-by: shaobingqing Signed-off-by: Trond Myklebust --- net/sunrpc/xprtsock.c | 28 ++++++++-------------------- 1 file changed, 8 insertions(+), 20 deletions(-) (limited to 'net/sunrpc/xprtsock.c') diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 0addefc..966763d 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -1306,41 +1306,29 @@ static inline int xs_tcp_read_reply(struct rpc_xprt *xprt, * If we're unable to obtain the rpc_rqst we schedule the closing of the * connection and return -1. */ -static inline int xs_tcp_read_callback(struct rpc_xprt *xprt, +static int xs_tcp_read_callback(struct rpc_xprt *xprt, struct xdr_skb_reader *desc) { struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt); struct rpc_rqst *req; - req = xprt_alloc_bc_request(xprt); + /* Look up and lock the request corresponding to the given XID */ + spin_lock(&xprt->transport_lock); + req = xprt_lookup_bc_request(xprt, transport->tcp_xid); if (req == NULL) { + spin_unlock(&xprt->transport_lock); printk(KERN_WARNING "Callback slot table overflowed\n"); xprt_force_disconnect(xprt); return -1; } - req->rq_xid = transport->tcp_xid; dprintk("RPC: read callback XID %08x\n", ntohl(req->rq_xid)); xs_tcp_read_common(xprt, desc, req); - if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) { - struct svc_serv *bc_serv = xprt->bc_serv; - - /* - * Add callback request to callback list. The callback - * service sleeps on the sv_cb_waitq waiting for new - * requests. Wake it up after adding enqueing the - * request. - */ - dprintk("RPC: add callback request to list\n"); - spin_lock(&bc_serv->sv_cb_lock); - list_add(&req->rq_bc_list, &bc_serv->sv_cb_list); - spin_unlock(&bc_serv->sv_cb_lock); - wake_up(&bc_serv->sv_cb_waitq); - } - - req->rq_private_buf.len = transport->tcp_copied; + if (!(transport->tcp_flags & TCP_RCV_COPY_DATA)) + xprt_complete_bc_request(req, transport->tcp_copied); + spin_unlock(&xprt->transport_lock); return 0; } -- cgit v1.1