Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754623Ab0F0SRq (ORCPT ); Sun, 27 Jun 2010 14:17:46 -0400 Received: from e23smtp07.au.ibm.com ([202.81.31.140]:52430 "EHLO e23smtp07.au.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753837Ab0F0SRl convert rfc822-to-8bit (ORCPT ); Sun, 27 Jun 2010 14:17:41 -0400 From: "Aneesh Kumar K. V" To: Mingming Cao , Steve French , "DENIEL Philippe" Cc: David Howells , Jeff Layton , Jeff Layton , linux-cifs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, samba-technical@lists.samba.org, Suresh Jayaraman Subject: Re: [RFC][PATCH 06/10] cifs: define inode-level cache object and register them In-Reply-To: References: <20100625125306.7f9b1966@tlielax.poochiereds.net> <4C24A606.5040001@suse.de> <1277220214-3597-1-git-send-email-sjayaraman@suse.de> <9822.1277312573@redhat.com> <22697.1277470549@redhat.com> <18628.1277502398@redhat.com> <20100625182651.36800d06@tlielax.poochiereds.net> User-Agent: Notmuch/ (http://notmuchmail.org) Emacs/24.0.50.1 (i686-pc-linux-gnu) Date: Sun, 27 Jun 2010 23:47:21 +0530 Message-ID: <871vbscpce.fsf@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3227 Lines: 90 On Fri, 25 Jun 2010 17:52:24 -0700, Mingming Cao wrote: > > > Steve French wrote on 06/25/2010 04:05:30 PM: > > > Steve French > > 06/25/2010 04:05 PM > > > > To > > > > Jeff Layton , "Aneesh Kumar K.V" > > , Mingming Cao/Beaverton/IBM@IBMUS > > > > cc > > > > David Howells , Suresh Jayaraman > > , linux-cifs@vger.kernel.org, linux- > > fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, samba- > > technical@lists.samba.org, Jeff Layton > > > > Subject > > > > Re: [RFC][PATCH 06/10] cifs: define inode-level cache object and > > register them > > > > On Fri, Jun 25, 2010 at 5:26 PM, Jeff Layton wrote: > > > > > > On Fri, 25 Jun 2010 22:46:38 +0100 > > > David Howells wrote: > > > > > > > Jeff Layton wrote: > > > > > > > > > Looks like it mostly uses the ctime. IMO, the mtime would be a > better > > > > > choice since it changes less frequently, but I don't guess that it > > > > > matters very much. > > > > > > > > I'd've thought mtime changes more frequently since that's > > altered when data is > > > > written.  ctime is changed when attributes are changed. > > > > > > > > > > IIUC, updating mtime for a write is also an attribute change, and that > > > affects ctime. According to the stat(2) manpage: > > > > > >       The field st_ctime is changed by writing or by setting > >  inode  informa- > > >       tion (i.e., owner, group, link count, mode, etc.). > > > > > > > Note that Ext4 appears to have a file creation time field in its > inode > > > > (struct ext4_inode::i_crtime[_extra]).  Can Samba be made to use > that? > > > > > > > > > > Is it exposed to userspace in any (standard) way? It would be handy to > > > have that. While we're wishing...it might also be nice to have a > > > standard way to get at the i_generation from userspace too. > > > > > > > Yes - I have talked with MingMing and Aneesh about those (NFS may > > someday be able to use those too).  An obstacle in the past had been > > that samba server stores its own fake creation time in an ndr encoded > > xattr which complicates things. > > > > MingMing/Annesh - > > Xattr or other way to get at birth time? > > > > > > Not yet, > The ext4 file creation time only accesable from the kernel at the moment. > There were discussion > to make this information avaliable via xattr before, but was rejected, > since most people > agree that making this info avalibele via stat() is more standard. However > modifying stat() would imply > big interface change. thus no action has been taken yet. NFS ganesha pNFS also had a requirement for getting i_generation and inode number in userspace. So may be we should now look at updating stat or add a variant syscall that include i_generation and create time in the return value -aneesh -- 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/