From: David Woodhouse Subject: Re: [RFC] Reinstate NFS exportability for JFFS2. Date: Fri, 01 Aug 2008 01:52:56 +0100 Message-ID: <1217551976.3719.24.camel@shinybook.infradead.org> References: <1209670979.25560.587.camel@pmac.infradead.org> <20080501204820.GA5951@infradead.org> <1209681898.25560.613.camel@pmac.infradead.org> <18458.28833.539314.455215@notabene.brown> <1217541264.1126.15.camel@shinybook.infradead.org> <18578.21997.529551.676627@notabene.brown> <1217551230.3719.15.camel@shinybook.infradead.org> Mime-Version: 1.0 Content-Type: text/plain Cc: Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mtd@lists.infradead.org To: Neil Brown Return-path: Received: from bombadil.infradead.org ([18.85.46.34]:59635 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752431AbYHAAw6 (ORCPT ); Thu, 31 Jul 2008 20:52:58 -0400 In-Reply-To: <1217551230.3719.15.camel-Fexsq3y4057IgHVZqg5X0TlWvGAXklZc@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Fri, 2008-08-01 at 01:40 +0100, David Woodhouse wrote: > For any file system which has its own internal locking -- which includes > jffs2, btrfs, xfs, jfs, gfs*, ocfs* and probably others -- that > recursive call back into the file system will deadlock. It _would_ deadlock, I mean. They each have their own strategy to avoid it, for now. jffs2 and btrfs just don't provide export_ops so they avoid the problem, but we'd _like_ to be able to export them. xfs has the hack I've just transplanted. gfs2 has a 'lock is owned by me' check. Not sure about the others. -- David Woodhouse Open Source Technology Centre David.Woodhouse@intel.com Intel Corporation