From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nathan Scott Subject: Re: [RFC] Badness in __mutex_unlock_slowpath with XFS stress tests Date: Fri, 10 Mar 2006 09:30:42 +1100 Message-ID: <20060309223042.GC1135@frodo> References: <440FDF3E.8060400@in.ibm.com> <20060309120306.GA26682@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-fsdevel@vger.kernel.org, "linux-aio kvack.org" , lkml , suparna , akpm@osdl.org, linux-xfs@oss.sgi.com Return-path: Received: from omx2-ext.sgi.com ([192.48.171.19]:33458 "EHLO omx2.sgi.com") by vger.kernel.org with ESMTP id S1751136AbWCIWeh (ORCPT ); Thu, 9 Mar 2006 17:34:37 -0500 To: Christoph Hellwig , Suzuki Content-Disposition: inline In-Reply-To: <20060309120306.GA26682@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Thu, Mar 09, 2006 at 12:03:06PM +0000, Christoph Hellwig wrote: > On Thu, Mar 09, 2006 at 01:24:38PM +0530, Suzuki wrote: > > > > Missed out linux-aio & linux-fs-devel lists. Forwarding. > > > > Comments ? > > I've seen this too. The problem is that __generic_file_aio_read can return > with or without the i_mutex locked in the direct I/O case for filesystems > that set DIO_OWN_LOCKING. Not for reads AFAICT - __generic_file_aio_read + own-locking should always have released i_mutex at the end of the direct read - are you thinking of writes or have I missed something? > It's a nasty one and I haven't found a better solution > than copying lots of code from filemap.c into xfs. Er, eek? Hopefully thats not needed - from my reading of the code, all the i_mutex locking for direct reads lives inside direct-io.c, not filemap.c -- is the solution from my other mail not workable? (isn't it only writes that has the wierd buffered I/O fallback + i_sem/i_mutex locking interaction?). thanks. -- Nathan