Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756471Ab0F2WvR (ORCPT ); Tue, 29 Jun 2010 18:51:17 -0400 Received: from rcsinet10.oracle.com ([148.87.113.121]:59331 "EHLO rcsinet10.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755617Ab0F2WvP (ORCPT ); Tue, 29 Jun 2010 18:51:15 -0400 Date: Tue, 29 Jun 2010 15:48:44 -0700 From: Joel Becker To: David Howells Cc: Ulrich Drepper , viro@zeniv.linux.org.uk, smfrench@gmail.com, jlayton@redhat.com, mcao@us.ibm.com, aneesh.kumar@linux.vnet.ibm.com, linux-cifs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, samba-technical@lists.samba.org, sjayaraman@suse.de, linux-ext4@vger.kernel.org Subject: Re: [PATCH 3/3] Add a pair of system calls to make extended file stats available Message-ID: <20100629224844.GF4150@mail.oracle.com> Mail-Followup-To: David Howells , Ulrich Drepper , viro@zeniv.linux.org.uk, smfrench@gmail.com, jlayton@redhat.com, mcao@us.ibm.com, aneesh.kumar@linux.vnet.ibm.com, linux-cifs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, samba-technical@lists.samba.org, sjayaraman@suse.de, linux-ext4@vger.kernel.org References: <20100629200259.23196.81509.stgit@warthog.procyon.org.uk> <20100629200315.23196.68742.stgit@warthog.procyon.org.uk> <26026.1277851016@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <26026.1277851016@redhat.com> X-Burt-Line: Trees are cool. X-Red-Smith: Ninety feet between bases is perhaps as close as man has ever come to perfection. User-Agent: Mutt/1.5.20 (2009-06-14) X-Source-IP: acsmt355.oracle.com [141.146.40.155] X-Auth-Type: Internal IP X-CT-RefId: str=0001.0A090206.4C2A78B1.016E:SCFMA4539814,ss=1,fgs=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1248 Lines: 33 On Tue, Jun 29, 2010 at 11:36:56PM +0100, David Howells wrote: > Ulrich Drepper wrote: > > And while you're at it, maybe some spare fields at the end are nice. > > I made it so that the syscall can return variable length data: the main xstat > struct, plus extra records yet to be defined. They could even be variable > length and assembled/disassembled with something like the control message > macros for recvmsg(). The less variable length stuff the better, I think. At least, for the stuff stat(2) already returns, you should have a fixed-size structure. Even if I only pass the GIVE_ME_UIDS flag, I don't want to have to deal with the variable size stuff until I've actually asked for esoteric things. I'll know that the non-UIDS fields are garbage by the fact that I didn't ask for them. Joel -- "Time is an illusion, lunchtime doubly so." -Douglas Adams Joel Becker Consulting Software Developer Oracle E-mail: joel.becker@oracle.com Phone: (650) 506-8127 -- 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/