From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Greear Subject: Re: 3.7.10+: BUG Dentry still in use [unmount of cifs cifs] Date: Thu, 07 Mar 2013 14:18:13 -0800 Message-ID: <51391225.1020403@candelatech.com> References: <51363F80.8070609@candelatech.com> <20130307191914.GA1652@mguzik.brq.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: linux-cifs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Linux Kernel Mailing List , Jeff Layton To: Mateusz Guzik Return-path: In-Reply-To: <20130307191914.GA1652-v5fTkemuj/HkZJWtSm8s3NvLeJWuRmrY@public.gmane.org> Sender: linux-cifs-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: On 03/07/2013 11:19 AM, Mateusz Guzik wrote: > On Tue, Mar 05, 2013 at 10:54:56AM -0800, Ben Greear wrote: >> In doing some CIFS testing (utilizing it's feature to bind to local >> address..but not sure that matters), we saw this error when trying >> to un-mount. >> >> Our kernel is patched (nfs, some networking related patches), but there >> are no out-of-kernel patches to CIFS, so I don't *think* this is anything >> we could have caused. >> >> This problem appears to be easily reproducible, so we will be happy >> to test patches if anyone has any suggestions. >> >> BUG: Dentry ffff8800c07e43c0{i=45762,n=cifs2-01.7.lf-data} still in use (1) [unmount of cifs cifs] > > We encountered similar panic, but it was related to writes. In our case > the problem was that some cifsInodeInfo holding dentry references were > still around (in slow-work queue) during superblock destruction in unmount. > > I reproduced the problem on 3.8 kernel (sorry, no 3.7 handy) with reads > as well, which should match your scenario. > > I attached a patch that deals with this problem by grabbing refcounts to > cifs superblock on cifsInodeInfo creation. This delays sb destruction > until all cifsInodeInfos are gone. I didn't test it on 3.7.10 kernel but > it should work fine. The 3.7.10 patch applied cleanly and appears to fix our problem. Thanks so much for the patch! Ben -- Ben Greear Candela Technologies Inc http://www.candelatech.com