Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758469Ab3CFPYp (ORCPT ); Wed, 6 Mar 2013 10:24:45 -0500 Received: from mail-lb0-f174.google.com ([209.85.217.174]:59212 "EHLO mail-lb0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757862Ab3CFPYn (ORCPT ); Wed, 6 Mar 2013 10:24:43 -0500 MIME-Version: 1.0 In-Reply-To: <20130306084004.05acd57c@tlielax.poochiereds.net> References: <1361446379-7970-1-git-send-email-jlayton@redhat.com> <20130306084004.05acd57c@tlielax.poochiereds.net> Date: Wed, 6 Mar 2013 10:24:41 -0500 Message-ID: Subject: Re: [PATCH] cifs: remove the sockopt= mount option From: Scott Lovenberg To: Jeff Layton Cc: Steve French , LKML , linux-fsdevel , linux-cifs@vger.kernel.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2467 Lines: 61 On Wed, Mar 6, 2013 at 8:40 AM, Jeff Layton wrote: > On Mon, 4 Mar 2013 16:08:30 -0600 > Steve French wrote: > >> Resending patch to a slightly broader list for last minute check if >> anyone objects. Although setting this particular socket option >> (TCP_NODELAY) may not be as useful when corking/uncorking explicitly, >> I want to doublecheck before removing them because there has been some >> utility to the server allowing override of various sockopt options. >> Samba server has long supported at least the following set of settable >> socket options (although I don't know if the defaults are frequently >> overridden now, by setting sockopts in smb.conf as used to be common >> for the server). >> >> SO_KEEPALIVE >> SO_REUSEADDR >> SO_BROADCAST >> TCP_NODELAY >> IPTOS_LOWDELAY >> IPTOS_THROUGHPUT >> SO_SNDBUF * >> SO_RCVBUF * >> SO_SNDLOWAT * >> SO_RCVLOWAT * >> >> * takes an integer argument rather than a boolean on/off >> >> Any objections to removing the ability to set socket options >> explicitly for the cifs network file system client? >> > > A couple of points... > > The sockopt= option was never documented in the mount.cifs manpage and > the only value it ever accepted was TCP_NODELAY. Now that we're > explicitly corking the socket, TCP_NODELAY has no effect. I don't think > there's any value in leaving in a "placeholder" socket= option. > After doing some research, I agree. I've been updating the socket options section of the Samba smb.conf man page and the performance section of the Samba HOWTO. The more research I do the more convinced that there is almost no reason to set most socket options on a modern Linux kernel or in Samba (server or client side). One thing pointed out to me in another thread is that the smbd server sets TCP_NODELAY by default. AIUI this was because the TCP_NODELAY option used to almost double the speed of SMB in some cases due to the way Microsoft's old TCP/IP stack sent ACKs. This is all to say that I think the "sockopt" option can go altogether since it's unlikely that any socket options will be needed in the future and the only one that was supported is now useless. -- Peace and Blessings, -Scott. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/