Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756106AbaAWAoY (ORCPT ); Wed, 22 Jan 2014 19:44:24 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:38512 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756159AbaAWAoJ convert rfc822-to-8bit (ORCPT ); Wed, 22 Jan 2014 19:44:09 -0500 User-Agent: K-9 Mail for Android In-Reply-To: <52D3FF0E02000078001131A5@nat28.tlf.novell.com> References: <1389608052-7139-1-git-send-email-olaf@aepfle.de> <52D3DAEE0200007800112FD4@nat28.tlf.novell.com> <20140113120131.GA15623@aepfle.de> <52D3EB5F02000078001130B5@nat28.tlf.novell.com> <1389618054.13654.57.camel@kazak.uk.xensource.com> <52D3F535020000780011311B@nat28.tlf.novell.com> <52D3EE14.3080609@citrix.com> <52D3FF0E02000078001131A5@nat28.tlf.novell.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Subject: Re: [Xen-devel] [PATCH v2] xen-blkfront: remove type check from blkfront_setup_discard From: Konrad Rzeszutek Wilk Date: Mon, 13 Jan 2014 10:57:54 -0500 To: Jan Beulich , David Vrabel CC: boris.ostrovsky@oracle.com, linux-kernel@vger.kernel.org, Olaf Hering , Ian Campbell , xen-devel@lists.xen.org Message-ID: <9498309b-dd60-413f-9ab7-8e6ec6c9bcfa@email.android.com> X-Source-IP: ucsinet22.oracle.com [156.151.31.94] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Jan Beulich wrote: >>>> On 13.01.14 at 14:45, David Vrabel wrote: >> On 13/01/14 13:16, Jan Beulich wrote: >>>>>> On 13.01.14 at 14:00, Ian Campbell >wrote: >>>> On Mon, 2014-01-13 at 12:34 +0000, Jan Beulich wrote: >>>>>>>> On 13.01.14 at 13:01, Olaf Hering wrote: >>>>>> On Mon, Jan 13, Jan Beulich wrote: >>>>>> >>>>>>> You can't do this in one go - the first two and the last one may >be >>>>>>> set independently (and are independent in their meaning), and >>>>>>> hence need to be queried independently (xenbus_gather() fails >>>>>>> on the first absent value). >>>>>> >>>>>> Yes, thats the purpose. Since the properties are required its an >all or >>>>>> nothing thing. If they are truly optional then blkif.h should be >updated >>>>>> to say that. >>>>> >>>>> They _are_ optional. >>>> >>>> But is it true that either they are all present or they are all >absent? >>> >>> No, it's not. discard-secure is independent of the other two (but >>> those other two are tied together). >> >> Can we have a patch to blkif.h that clarifies this? >> >> e.g., >> >> feature-discard >> >> ... >> >> discard-granularity and discard-offset must also be present if >> feature-discard is enabled > >It would be "may" here too afaict. But I'll defer to Konrad, who >has done more work in this area... > >Jan > >> discard-secure may also be present if feature-discard is enabled. >> >> David > > > > >_______________________________________________ >Xen-devel mailing list >Xen-devel@lists.xen.org >http://lists.xen.org/xen-devel It is all 'may'. If there is just 'feature-discard' without any other options that is OK. -- 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/