From 9ffadfbc092fc25d9639a019fb3079cf352ef978 Mon Sep 17 00:00:00 2001 From: Trond Myklebust Date: Sun, 29 May 2016 00:42:03 -0400 Subject: [PATCH] SUNRPC: Fix suspicious enobufs issues. The current test is racy when dealing with fast NICs. Signed-off-by: Trond Myklebust --- net/sunrpc/xprtsock.c | 31 +++++++++++++++++++++++++------ 1 file changed, 25 insertions(+), 6 deletions(-) diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 646170d0cb86..6b3efeb3edc5 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -642,6 +642,7 @@ static int xs_tcp_send_request(struct rpc_task *task) struct sock_xprt *transport = container_of(xprt, struct sock_xprt, xprt); struct xdr_buf *xdr = &req->rq_snd_buf; bool zerocopy = true; + bool vm_wait = false; int status; int sent; @@ -677,15 +678,33 @@ static int xs_tcp_send_request(struct rpc_task *task) return 0; } + WARN_ON_ONCE(sent == 0 && status == 0); + + if (status == -EAGAIN ) { + /* + * Return EAGAIN if we're sure we're hitting the + * socket send buffer limits. + */ + if (test_bit(SOCK_NOSPACE, &transport->sock->flags)) + break; + /* + * Did we hit a memory allocation failure? + */ + if (sent == 0) { + status = -ENOBUFS; + if (vm_wait) + break; + /* Retry, knowing now that we're below the + * socket send buffer limit + */ + vm_wait = true; + } + continue; + } if (status < 0) break; - if (sent == 0) { - status = -EAGAIN; - break; - } + vm_wait = false; } - if (status == -EAGAIN && sk_stream_is_writeable(transport->inet)) - status = -ENOBUFS; switch (status) { case -ENOTSOCK: -- 2.34.1