Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:54361 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755525Ab2HTVwM (ORCPT ); Mon, 20 Aug 2012 17:52:12 -0400 Date: Mon, 20 Aug 2012 17:52:10 -0400 To: linux-nfs@vger.kernel.org Cc: NeilBrown , Malahal Naineni Subject: [PATCH] svcrpc: sends on closed socket should stop immediately Message-ID: <20120820215210.GJ5779@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii From: "J. Bruce Fields" Sender: linux-nfs-owner@vger.kernel.org List-ID: From: "J. Bruce Fields" svc_tcp_sendto sets XPT_CLOSE if we fail to transmit the entire reply. However, the XPT_CLOSE won't be acted on immediately. Meanwhile other threads could send further replies before the socket is really shut down. This can manifest as data corruption: for example, if a truncated read reply is followed by another rpc reply, that second reply will look to the client like further read data. Symptoms were data corruption preceded by svc_tcp_sendto logging something like kernel: rpc-srv/tcp: nfsd: sent only 963696 when sending 1048708 bytes - shutting down socket Cc: stable@vger.kernel.org Reported-by: Malahal Naineni Signed-off-by: J. Bruce Fields --- net/sunrpc/svc_xprt.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) Can anyone see a reason *not* to fail the send on a socket marked with XPT_CLOSE? diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c index 88f2bf6..0d693a8 100644 --- a/net/sunrpc/svc_xprt.c +++ b/net/sunrpc/svc_xprt.c @@ -794,7 +794,8 @@ int svc_send(struct svc_rqst *rqstp) /* Grab mutex to serialize outgoing data. */ mutex_lock(&xprt->xpt_mutex); - if (test_bit(XPT_DEAD, &xprt->xpt_flags)) + if (test_bit(XPT_DEAD, &xprt->xpt_flags) + || test_bit(XPT_CLOSE, &xprt->xpt_flags)) len = -ENOTCONN; else len = xprt->xpt_ops->xpo_sendto(rqstp); -- 1.7.9.5