From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kani, Toshimitsu" Subject: Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Date: Mon, 13 Jun 2016 23:59:20 +0000 Message-ID: <1465861755.3504.185.camel@hpe.com> References: <1465856497-19698-1-git-send-email-toshi.kani@hpe.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: Content-Language: en-US Content-ID: Sender: linux-kernel-owner@vger.kernel.org To: "dan.j.williams@intel.com" Cc: "linux-kernel@vger.kernel.org" , "agk@redhat.com" , "linux-raid@vger.kernel.org" , "snitzer@redhat.com" , "viro@zeniv.linux.org.uk" , "axboe@kernel.dk" , "linux-nvdimm@lists.01.org" , "ross.zwisler@linux.intel.com" , "dm-devel@redhat.com" List-Id: dm-devel.ids T24gTW9uLCAyMDE2LTA2LTEzIGF0IDE2OjE4IC0wNzAwLCBEYW4gV2lsbGlhbXMgd3JvdGU6DQo+ IFRoYW5rcyBUb3NoaSENCj4gDQo+IE9uIE1vbiwgSnVuIDEzLCAyMDE2IGF0IDM6MjEgUE0sIFRv c2hpIEthbmkgPHRvc2hpLmthbmlAaHBlLmNvbT4gd3JvdGU6DQo+ID4gDQo+ID4gVGhpcyBwYXRj aC1zZXQgYWRkcyBEQVggc3VwcG9ydCB0byBkZXZpY2UtbWFwcGVyIGRtLWxpbmVhciBkZXZpY2Vz DQo+ID4gdXNlZCBieSBMVk0uwqDCoEl0IHdvcmtzIHdpdGggTFZNIGNvbW1hbmRzIGFzIGZvbGxv d3M6DQo+ID4gwqAtIENyZWF0aW9uIG9mIGEgbG9naWNhbCB2b2x1bWUgd2l0aCBhbGwgREFYIGNh cGFibGUgZGV2aWNlcyAoc3VjaA0KPiA+IMKgwqDCoGFzIHBtZW0pIHNldHMgdGhlIGxvZ2ljYWwg dm9sdW1lIERBWCBjYXBhYmxlIGFzIHdlbGwuDQo+ID4gwqAtIE9uY2UgYSBsb2dpY2FsIHZvbHVt ZSBpcyBzZXQgdG8gREFYIGNhcGFibGUsIHRoZSB2b2x1bWUgbWF5IG5vdA0KPiA+IMKgwqDCoGJl IGV4dGVuZGVkIHdpdGggbm9uLURBWCBjYXBhYmxlIGRldmljZXMuDQo+DQo+IEkgZG9uJ3QgbWlu ZCB0aGlzLCBidXQgaXQgc2VlbXMgYSBwb2xpY3kgZGVjaXNpb24gdGhhdCB0aGUga2VybmVsIGRv ZXMNCj4gbm90IG5lZWQgdG8gbWFrZS7CoMKgQSBzdWZmaWNpZW50bHkgc29waGlzdGljYXRlZCB1 c2VyIGNvdWxkIGNvcGUgd2l0aA0KPiBEQVggYmVpbmcgYXZhaWxhYmxlIGF0IHZhcnlpbmcgTEJB cy7CoMKgV291bGQgaXQgYmUgc3VmZmljaWVudCB0byBtb3ZlDQo+IHRoaXMgcG9saWN5IGRlY2lz aW9uIHRvIHVzZXJzcGFjZSB0b29saW5nPw0KDQpJIHRoaW5rIHRoaXMgaXMgYSBrZXJuZWwgcmVz dHJpY3Rpb24uIMKgV2hlbiBhIGJsb2NrIGRldmljZSBpcyBkZWNsYXJlZCBhcw0KREFYIGNhcGFi bGUsIGl0IHNob3VsZCBtZWFuIHRoYXQgdGhlIHdob2xlIGRldmljZSBpcyBEQVggY2FwYWJsZS4g wqBTbywgSQ0KdGhpbmsgd2UgbmVlZCB0byBhc3N1cmUgdGhlIHNhbWUgdG8gYSBtYXBwZWQgZGV2 aWNlLg0KDQpJbiBMVk0gbGV2ZWwsIGEgdm9sdW1lIGdyb3VwIG1heSBjb250YWluIGJvdGggREFY IGFuZCBub24tREFYIGNhcGFibGUNCmRldmljZXMuIMKgVGhlcmUgaXMgbm8gcmVzdHJpY3Rpb24g Zm9yIGNyZWF0aW5nL2V4dGVuZGluZyBhIHZvbHVtZSBncm91cC4NCg0KPiA+IFRoZSBkaXJlY3Rf YWNjZXNzIGludGVyZmFjZSBpcyBhZGRlZCB0byBkbSBhbmQgZG0tbGluZWFyIHRvIG1hcA0KPiA+ IGEgcmVxdWVzdCB0byBhIHRhcmdldCBkZXZpY2UuDQo+DQo+IEkgaGFkIGRtLWxpbmVhciBhbmQg bWQtcmFpZDAgc3VwcG9ydCBvbiBteSBsaXN0IG9mIHRoaW5ncyB0byBsb29rIGF0LA0KPiBkaWQg eW91IGhhdmUgcmFpZDAgaW4geW91ciBwbGFucz8NCg0KWWVzLCBJIGhvcGUgdG8gZXh0ZW5kIGZ1 cnRoZXIgYW5kIHJhaWQwIGlzIGEgZ29vZCBjYW5kaWRhdGUuIMKgwqANCg0KVGhhbmtzLA0KLVRv c2hpDQo= From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from na01-bn1-obe.outbound.protection.outlook.com (mail-bn1bon0702.outbound.protection.outlook.com [IPv6:2a01:111:f400:fc10::1:702]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by ml01.01.org (Postfix) with ESMTPS id DADD91A1DF7 for ; Mon, 13 Jun 2016 16:59:46 -0700 (PDT) From: "Kani, Toshimitsu" Subject: Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Date: Mon, 13 Jun 2016 23:59:20 +0000 Message-ID: <1465861755.3504.185.camel@hpe.com> References: <1465856497-19698-1-git-send-email-toshi.kani@hpe.com> In-Reply-To: Content-Language: en-US Content-ID: MIME-Version: 1.0 List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Errors-To: linux-nvdimm-bounces@lists.01.org Sender: "Linux-nvdimm" To: "dan.j.williams@intel.com" Cc: "axboe@kernel.dk" , "snitzer@redhat.com" , "linux-nvdimm@lists.01.org" , "linux-kernel@vger.kernel.org" , "linux-raid@vger.kernel.org" , "dm-devel@redhat.com" , "viro@zeniv.linux.org.uk" , "agk@redhat.com" List-ID: T24gTW9uLCAyMDE2LTA2LTEzIGF0IDE2OjE4IC0wNzAwLCBEYW4gV2lsbGlhbXMgd3JvdGU6DQo+ IFRoYW5rcyBUb3NoaSENCj4gDQo+IE9uIE1vbiwgSnVuIDEzLCAyMDE2IGF0IDM6MjEgUE0sIFRv c2hpIEthbmkgPHRvc2hpLmthbmlAaHBlLmNvbT4gd3JvdGU6DQo+ID4gDQo+ID4gVGhpcyBwYXRj aC1zZXQgYWRkcyBEQVggc3VwcG9ydCB0byBkZXZpY2UtbWFwcGVyIGRtLWxpbmVhciBkZXZpY2Vz DQo+ID4gdXNlZCBieSBMVk0uwqDCoEl0IHdvcmtzIHdpdGggTFZNIGNvbW1hbmRzIGFzIGZvbGxv d3M6DQo+ID4gwqAtIENyZWF0aW9uIG9mIGEgbG9naWNhbCB2b2x1bWUgd2l0aCBhbGwgREFYIGNh cGFibGUgZGV2aWNlcyAoc3VjaA0KPiA+IMKgwqDCoGFzIHBtZW0pIHNldHMgdGhlIGxvZ2ljYWwg dm9sdW1lIERBWCBjYXBhYmxlIGFzIHdlbGwuDQo+ID4gwqAtIE9uY2UgYSBsb2dpY2FsIHZvbHVt ZSBpcyBzZXQgdG8gREFYIGNhcGFibGUsIHRoZSB2b2x1bWUgbWF5IG5vdA0KPiA+IMKgwqDCoGJl IGV4dGVuZGVkIHdpdGggbm9uLURBWCBjYXBhYmxlIGRldmljZXMuDQo+DQo+IEkgZG9uJ3QgbWlu ZCB0aGlzLCBidXQgaXQgc2VlbXMgYSBwb2xpY3kgZGVjaXNpb24gdGhhdCB0aGUga2VybmVsIGRv ZXMNCj4gbm90IG5lZWQgdG8gbWFrZS7CoMKgQSBzdWZmaWNpZW50bHkgc29waGlzdGljYXRlZCB1 c2VyIGNvdWxkIGNvcGUgd2l0aA0KPiBEQVggYmVpbmcgYXZhaWxhYmxlIGF0IHZhcnlpbmcgTEJB cy7CoMKgV291bGQgaXQgYmUgc3VmZmljaWVudCB0byBtb3ZlDQo+IHRoaXMgcG9saWN5IGRlY2lz aW9uIHRvIHVzZXJzcGFjZSB0b29saW5nPw0KDQpJIHRoaW5rIHRoaXMgaXMgYSBrZXJuZWwgcmVz dHJpY3Rpb24uIMKgV2hlbiBhIGJsb2NrIGRldmljZSBpcyBkZWNsYXJlZCBhcw0KREFYIGNhcGFi bGUsIGl0IHNob3VsZCBtZWFuIHRoYXQgdGhlIHdob2xlIGRldmljZSBpcyBEQVggY2FwYWJsZS4g wqBTbywgSQ0KdGhpbmsgd2UgbmVlZCB0byBhc3N1cmUgdGhlIHNhbWUgdG8gYSBtYXBwZWQgZGV2 aWNlLg0KDQpJbiBMVk0gbGV2ZWwsIGEgdm9sdW1lIGdyb3VwIG1heSBjb250YWluIGJvdGggREFY IGFuZCBub24tREFYIGNhcGFibGUNCmRldmljZXMuIMKgVGhlcmUgaXMgbm8gcmVzdHJpY3Rpb24g Zm9yIGNyZWF0aW5nL2V4dGVuZGluZyBhIHZvbHVtZSBncm91cC4NCg0KPiA+IFRoZSBkaXJlY3Rf YWNjZXNzIGludGVyZmFjZSBpcyBhZGRlZCB0byBkbSBhbmQgZG0tbGluZWFyIHRvIG1hcA0KPiA+ IGEgcmVxdWVzdCB0byBhIHRhcmdldCBkZXZpY2UuDQo+DQo+IEkgaGFkIGRtLWxpbmVhciBhbmQg bWQtcmFpZDAgc3VwcG9ydCBvbiBteSBsaXN0IG9mIHRoaW5ncyB0byBsb29rIGF0LA0KPiBkaWQg eW91IGhhdmUgcmFpZDAgaW4geW91ciBwbGFucz8NCg0KWWVzLCBJIGhvcGUgdG8gZXh0ZW5kIGZ1 cnRoZXIgYW5kIHJhaWQwIGlzIGEgZ29vZCBjYW5kaWRhdGUuIMKgwqANCg0KVGhhbmtzLA0KLVRv c2hpDQpfX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwpMaW51 eC1udmRpbW0gbWFpbGluZyBsaXN0CkxpbnV4LW52ZGltbUBsaXN0cy4wMS5vcmcKaHR0cHM6Ly9s aXN0cy4wMS5vcmcvbWFpbG1hbi9saXN0aW5mby9saW51eC1udmRpbW0K From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1422966AbcFMX7Z (ORCPT ); Mon, 13 Jun 2016 19:59:25 -0400 Received: from mail-bl2on0129.outbound.protection.outlook.com ([65.55.169.129]:59392 "EHLO na01-bl2-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1030193AbcFMX7X (ORCPT ); Mon, 13 Jun 2016 19:59:23 -0400 From: "Kani, Toshimitsu" To: "dan.j.williams@intel.com" CC: "linux-kernel@vger.kernel.org" , "agk@redhat.com" , "linux-raid@vger.kernel.org" , "snitzer@redhat.com" , "viro@zeniv.linux.org.uk" , "axboe@kernel.dk" , "linux-nvdimm@lists.01.org" , "ross.zwisler@linux.intel.com" , "dm-devel@redhat.com" Subject: Re: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Thread-Topic: [PATCH 0/6] Support DAX for device-mapper dm-linear devices Thread-Index: AQHRxcNvFc0gDtWw/UKSuO/qIYbBN5/oCDUAgAAIpoA= Date: Mon, 13 Jun 2016 23:59:20 +0000 Message-ID: <1465861755.3504.185.camel@hpe.com> References: <1465856497-19698-1-git-send-email-toshi.kani@hpe.com> In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: authentication-results: spf=none (sender IP is ) smtp.mailfrom=toshi.kani@hpe.com; x-originating-ip: [15.219.163.9] x-ms-office365-filtering-correlation-id: d9231c4a-aebd-40c5-45a8-08d393e6bc95 x-microsoft-exchange-diagnostics: 1;DF4PR84MB0011;5:CD0s9F89ejB0Sk4ZmT1MCLK/qIX3I1wn782dJz48/icOxTjn5L7CRly/DfarH+kUqxPMoa/3qFV7Ma+gtcUC2W5l7Z4L1vM3Ciz524jWisb2bZhqcr+NK6KbQeuvqNhRzYj5jQgrMWvVnky8L31hCQ==;24:j1HT98Gii/0TIfgT+b6B/OAM1+8DA9I+V96mgr0Ndm/rgdYA0TDBamhKUKz4nTXDwssZpLxRrV70LimLloIKy1SJrmVbs8rg2fgbMjcx6A8=;7:NqM8s0MmJqTXxnlw+OewlccmBYRLxUlJb3LZwLU1gF/cuHMPkdrX+a9fl+EJtkngWHgWtKHQ9qzgr/tD/IHfRvZd8++AlU7GB6oH2HxJJGMjqBTuFiT0/DZ2B3hfETd8mKAvctja287DsCEUxQsYBTBcW/mz0gnTrVWSs9drHtt1sxCKDhbvof4ErdqGJF2mVbsJP8lj/jD/b1wJzNCpjWN7tkWSOPtVupryjV870cA= x-microsoft-antispam: UriScan:;BCL:0;PCL:0;RULEID:;SRVR:DF4PR84MB0011; x-microsoft-antispam-prvs: x-exchange-antispam-report-test: UriScan:(227479698468861); x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(601004)(2401047)(8121501046)(5005006)(3002001)(10201501046);SRVR:DF4PR84MB0011;BCL:0;PCL:0;RULEID:;SRVR:DF4PR84MB0011; x-forefront-prvs: 0972DEC1D9 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(6009001)(7916002)(189002)(199003)(377454003)(377424004)(24454002)(33646002)(81156014)(81166006)(2950100001)(586003)(5004730100002)(3846002)(102836003)(6116002)(2900100001)(8676002)(122556002)(66066001)(86362001)(77096005)(4326007)(99286002)(19580405001)(36756003)(68736007)(19580395003)(5640700001)(189998001)(87936001)(2501003)(3660700001)(54356999)(3280700002)(2906002)(110136002)(101416001)(106356001)(5008740100001)(76176999)(103116003)(97736004)(105586002)(106116001)(50986999)(92566002)(5002640100001)(10400500002)(2351001)(8936002);DIR:OUT;SFP:1102;SCL:1;SRVR:DF4PR84MB0011;H:DF4PR84MB0010.NAMPRD84.PROD.OUTLOOK.COM;FPR:;SPF:None;PTR:InfoNoRecords;MX:1;A:1;LANG:en; spamdiagnosticoutput: 1:99 spamdiagnosticmetadata: NSPM Content-Type: text/plain; charset="utf-8" Content-ID: MIME-Version: 1.0 X-OriginatorOrg: hpe.com X-MS-Exchange-CrossTenant-originalarrivaltime: 13 Jun 2016 23:59:20.2688 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 105b2061-b669-4b31-92ac-24d304d195dc X-MS-Exchange-Transport-CrossTenantHeadersStamped: DF4PR84MB0011 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id u5DNxVfw013063 On Mon, 2016-06-13 at 16:18 -0700, Dan Williams wrote: > Thanks Toshi! > > On Mon, Jun 13, 2016 at 3:21 PM, Toshi Kani wrote: > > > > This patch-set adds DAX support to device-mapper dm-linear devices > > used by LVM.  It works with LVM commands as follows: > >  - Creation of a logical volume with all DAX capable devices (such > >    as pmem) sets the logical volume DAX capable as well. > >  - Once a logical volume is set to DAX capable, the volume may not > >    be extended with non-DAX capable devices. > > I don't mind this, but it seems a policy decision that the kernel does > not need to make.  A sufficiently sophisticated user could cope with > DAX being available at varying LBAs.  Would it be sufficient to move > this policy decision to userspace tooling? I think this is a kernel restriction.  When a block device is declared as DAX capable, it should mean that the whole device is DAX capable.  So, I think we need to assure the same to a mapped device. In LVM level, a volume group may contain both DAX and non-DAX capable devices.  There is no restriction for creating/extending a volume group. > > The direct_access interface is added to dm and dm-linear to map > > a request to a target device. > > I had dm-linear and md-raid0 support on my list of things to look at, > did you have raid0 in your plans? Yes, I hope to extend further and raid0 is a good candidate.    Thanks, -Toshi