From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from 173-166-109-252-newengland.hfc.comcastbusiness.net ([173.166.109.252]:38624 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752017Ab1G0UFz (ORCPT ); Wed, 27 Jul 2011 16:05:55 -0400 Date: Wed, 27 Jul 2011 16:05:50 -0400 From: Christoph Hellwig To: Bryan Schumaker Cc: Christoph Hellwig , Justin Piszcz , "J. Bruce Fields" , linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, xfs@oss.sgi.com Subject: Re: 2.6.xx: NFS: directory motion/cam2 contains a readdir loop Message-ID: <20110727200550.GA23416@infradead.org> References: <20110727160752.GC974@fieldses.org> <20110727181111.GA23009@infradead.org> <20110727193937.GA5354@infradead.org> <20110727194722.GA9345@infradead.org> <4E306D09.5030704@netapp.com> <20110727200240.GA16054@infradead.org> Content-Type: text/plain; charset=us-ascii In-Reply-To: <20110727200240.GA16054@infradead.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Wed, Jul 27, 2011 at 04:02:40PM -0400, Christoph Hellwig wrote: > But looking closer at it it only prints the directory name and not that > of any of the matching cookies, making it pretty useless to debug any > problem. (and it makes my previous question to Justin look stupid..). > > > But so far I still stick to my previous theory that this sounds like > a directory offset getting reused. How is cache invalidation for > the array supposed to work? And maybe more importantly, given that he > can only reproduce it with a .38 client did any bugs get fixed in that > code recently that might lead to issues with the cache invalidation? Actually we won't even need cache invalidation bugs, see nfsd_buffered_readdir() - we might do multiple vfs_readdir calls to fill a single nfs reply, and between these two directory contents might have been completely replaced, in the worst (pathological case) you might get a second readdir having exactly the same offsets, but pointing to completely different inodes.