From mboxrd@z Thu Jan 1 00:00:00 1970 From: Steve French Subject: Re: [RFC][PATCH 06/10] cifs: define inode-level cache object and register them Date: Fri, 25 Jun 2010 18:05:30 -0500 Message-ID: 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> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE 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 To: Jeff Layton , "Aneesh Kumar K.V" , Mingming Cao Return-path: In-Reply-To: <20100625182651.36800d06@tlielax.poochiereds.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org 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 be= tter > > > choice since it changes less frequently, but I don't guess that i= t > > > matters very much. > > > > I'd've thought mtime changes more frequently since that's altered w= hen data is > > written. =A0ctime is changed when attributes are changed. > > > > IIUC, updating mtime for a write is also an attribute change, and tha= t > affects ctime. According to the stat(2) manpage: > > =A0 =A0 =A0 The field st_ctime is changed by writing or by setting =A0= inode =A0informa- > =A0 =A0 =A0 tion (i.e., owner, group, link count, mode, etc.). > > > Note that Ext4 appears to have a file creation time field in its in= ode > > (struct ext4_inode::i_crtime[_extra]). =A0Can Samba be made to use = that? > > > > Is it exposed to userspace in any (standard) way? It would be handy t= o > 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).=A0 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? -- Thanks, Steve