From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Layton Subject: Re: [2.6.39] CIFS write failures where 2.6.38 works Date: Thu, 23 Jun 2011 08:00:24 -0400 Message-ID: <20110623080024.7a1cab88@tlielax.poochiereds.net> References: <4DE6103E.6010100@hist.no> <4DE8B449.2000008@suse.de> <4DE8F989.50208@hist.no> <20110609182845.1ebfc678@tlielax.poochiereds.net> <20110622163612.45744bc2@tlielax.poochiereds.net> <4E0322B0.8030102@hist.no> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: Suresh Jayaraman , Linux Kernel Mailing List , linux-cifs To: Helge Hafting Return-path: In-Reply-To: <4E0322B0.8030102@hist.no> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-cifs.vger.kernel.org On Thu, 23 Jun 2011 13:25:36 +0200 Helge Hafting wrote: > On 22. juni 2011 22:36, Jeff Layton wrote: > > On Thu, 9 Jun 2011 18:28:45 -0400 > > Jeff Layton wrote: > > > >> On Fri, 03 Jun 2011 17:11:05 +0200 > >> Helge Hafting wrote: > >> > >>> On 03. juni 2011 12:15, Suresh Jayaraman wrote: > >>>> [Cc linux-cifs@vger.kernel.org] > >>>> > >>>> On 06/01/2011 03:41 PM, Helge Hafting wrote: > >>>>> At work I use cifs for accessing a windows server. This has worked fine > >>>>> for a long time, up to and including Debian's 2.6.38-2. > >>>>> > >>>>> I just installed Debians's 2.6.39-1, and had to give up on it. > >>>>> Mounting CIFS works, and I can see the files. But if I > >>>>> try to make a new file (with cp), I get a long delay. > >>>> > >>>> What is the security mechanism you are using? If you seeing the problem > >>>> with ntlm, could you try using ntlmv2 and see whether the problem is > >>>> reproducible? > >>> > >>> In the beginning, I did not specify the mechanism. So, whatever the > >>> default is. > >>> > >>> The fstab entry was like this: > >>> \\servername\resource /mountpoint cifs > >>> domain=MYDOMAIN,credentials=/etc/fstabcred,rw,noauto,iocharset=utf8,uid=username,gid=group,sockopt=TCP_NODELAY,users,file_mode=0640,dir_mode=0750,relatime > >>> 0 0 > >>> > >>> I looked at cifs options, and tried to add "sign" and "sec=ntlmv2i". It > >>> made no difference. Still failure with 2.6.39, and mounting with these > >>> new options works fine with 2.6.38 > >>> > >> > >> I think we need to understand what's happening on the wire. Are you > >> still able to reproduce this? If so, can you turn up debug logging and > >> reproduce this?. Instructions for how to do that are here: > >> > >> http://wiki.samba.org/index.php/LinuxCIFS_troubleshooting#Enabling_Debugging > >> > >> Also, it looks like someone opened a bug at kernel.org too: > >> > >> https://bugzilla.kernel.org/show_bug.cgi?id=36952 > >> > >> ...so if you can attach the resulting log there, that would be great. > >> > > > > I think that this is probably due to the change that added the > > page_mkwrite function to cifs.ko. Prior to that, cifs did single-page > > writes on signed connections. Now we do multi-page writes and windows > > servers apparently reject large write calls on signed connections. > > > > One way to test this theory would be to set the wsize to something > > smaller when you mount. For instance: > > > > wsize=16384 > > > > ...assuming that doesn't go over the server's MaxBufferSize, then that > > should act as a workaround. Can you try that and let me know if it > > helps? > > > Yes, that seemed to fix it. I added wsize=16384 and mounted using > debians 2.6.39-1-amd64 kernel. > > I tried a recursive copy of 26MB from one directory tree to another on > that mount. It completed in 24s with no error messages. 1MB/s is not > much, but there may be 40 other users. > > The server runs windows 2008r2, 64-bit. > Great, thanks for testing that. I've already sent Steve French a patch that should fix this in 3.0, but we'll need to do something different for 2.6.39 stable. I'll roll up a patch for that soon. BTW, 3.0 should have much improved write performance, even with signing enabled as that adds the capability to do async writes. -- Jeff Layton