From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. Bruce Fields" Subject: Re: [PATCH -V14 0/11] Generic name to handle and open by handle syscalls Date: Tue, 6 Jul 2010 12:10:02 -0400 Message-ID: <20100706161002.GD7387@fieldses.org> References: <1276621981-2774-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> <871vbn2mk9.fsf@linux.vnet.ibm.com> <20100702064108.64034561@notabene.brown> <87iq4y29a6.fsf@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Neil Brown , hch@infradead.org, viro@zeniv.linux.org.uk, adilger@sun.com, corbet@lwn.net, serue@us.ibm.com, hooanon05@yahoo.co.jp, linux-fsdevel@vger.kernel.org, sfrench@us.ibm.com, philippe.deniel@CEA.FR, linux-kernel@vger.kernel.org To: "Aneesh Kumar K. V" Return-path: Received: from fieldses.org ([174.143.236.118]:58347 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754907Ab0GFQKU (ORCPT ); Tue, 6 Jul 2010 12:10:20 -0400 Content-Disposition: inline In-Reply-To: <87iq4y29a6.fsf@linux.vnet.ibm.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Fri, Jul 02, 2010 at 02:45:45AM +0530, Aneesh Kumar K. V wrote: > One use case i had was that if the userspace file server can directly > work with the returned file system UUID, I agree that the uuid should be split out from the rest of the filehandle, but ... > the it can build the file > handle for client in a single call. ... I don't understand why both need to come in the same system call. Is it purely an efficiency question? If so, why do you expect this to be significant? (I would have thought that the system call overhead is so small, and so many calls will already be required to perform the typical rpc, that this would be insignificant.) A filesystem uuid seems like a generally useful thing (maybe more so than a filehandle), so it'd seem worth figuring out how to export that separately. --b.