Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754994Ab2HPPHz (ORCPT ); Thu, 16 Aug 2012 11:07:55 -0400 Received: from mail-lpp01m010-f46.google.com ([209.85.215.46]:47166 "EHLO mail-lpp01m010-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753438Ab2HPPHx (ORCPT ); Thu, 16 Aug 2012 11:07:53 -0400 Date: Thu, 16 Aug 2012 19:07:49 +0400 From: Cyrill Gorcunov To: Al Viro Cc: James Bottomley , Pavel Emelianov , "J. Bruce Fields" , "linux-kernel@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" , Alexey Dobriyan , Andrew Morton , Matthew Helsley Subject: Re: [patch 4/8] fs, exportfs: Add export_encode_inode_fh helper Message-ID: <20120816150749.GC13382@moon> References: <20120816123814.GD1209@moon> <20120816134339.GQ23464@ZenIV.linux.org.uk> <502CF9DA.8030701@parallels.com> <20120816135019.GS23464@ZenIV.linux.org.uk> <20120816135448.GP32081@moon> <1345125779.3259.50.camel@dabdike.int.hansenpartnership.com> <20120816141553.GF1209@moon> <20120816144152.GT23464@ZenIV.linux.org.uk> <20120816144835.GC13066@moon> <20120816145527.GU23464@ZenIV.linux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120816145527.GU23464@ZenIV.linux.org.uk> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1325 Lines: 27 On Thu, Aug 16, 2012 at 03:55:27PM +0100, Al Viro wrote: > On Thu, Aug 16, 2012 at 06:48:35PM +0400, Cyrill Gorcunov wrote: > > > > Good luck doing that with e.g. VFAT... And then there's such thing > > > as filesystems that don't have ->encode_fh() for a lot of very good > > > > Wait, Al, it seems I messed up. If some fs has no encode_fh() implemented > > the default encoding with FILEID_INO32_GEN_PARENT will be used for that. > > ... which doesn't work for a lot of filesystems. Not if you want to be > able to decode the result afterwards and get something useful out of > that. Trying to implement ->fh_to_dentry(), especially with fhandle > generated by inode alone is going to be really interesting for a bunch > of stuff... hmm, yup (and Bruce just pointed me to exportfs_decode_fh). So, if fs doesn't provide encode_fh (and decode as well) but the FILEID_INO32_GEN_PARENT used instead, we will not be able to restore such inotify later. Then I suppose such application will be unrestorable at least for a while. Would not this be acceptable trade off? Cyrill -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/