From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2CB3EC282D7 for ; Thu, 31 Jan 2019 01:25:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E84DA20B1F for ; Thu, 31 Jan 2019 01:25:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726464AbfAaBZe (ORCPT ); Wed, 30 Jan 2019 20:25:34 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:2710 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725535AbfAaBZe (ORCPT ); Wed, 30 Jan 2019 20:25:34 -0500 Received: from DGGEMS410-HUB.china.huawei.com (unknown [172.30.72.60]) by Forcepoint Email with ESMTP id DAD9FDAF8F2BBF840F65; Thu, 31 Jan 2019 09:25:31 +0800 (CST) Received: from [127.0.0.1] (10.184.189.120) by DGGEMS410-HUB.china.huawei.com (10.3.19.210) with Microsoft SMTP Server id 14.3.408.0; Thu, 31 Jan 2019 09:25:30 +0800 Subject: Re: block: Fix a WRITE SAME BUG_ON To: John Dorminy , "Martin K. Petersen" CC: Mike Snitzer , , , , Alasdair G Kergon References: <20190125021107.4595-1-zhangxiaoxu5@huawei.com> <20190128221441.GA24102@redhat.com> From: "zhangxiaoxu (A)" Message-ID: Date: Thu, 31 Jan 2019 08:58:24 +0800 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8"; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-Originating-IP: [10.184.189.120] X-CFilter-Loop: Reflected Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 1/30/2019 10:08 PM, John Dorminy wrote: > Alternately, could possibly WRITE_SAME bios be accepted with the > minimum sector size of the stack rather than the max, e.g. 512 in this > example rather than 4k? They'd need to have a granularity of the > larger sector size, though, presumabily necessitating new queue limits > write_same_{granularity,block_size}, which might be too much work. For > devices with bigger sectors, the block layer or DM would need to > expand the small-sector payload to an appropriate larger-sector > payload, but it would preserve the ability to use WRITE_SAME with > non-zero payloads. > > (I use WRITE_SAME to fill devices with a particular pattern in order > to catch failures to initialize disk structures appropriately, > personally, but it's just for convenience/speed.) I think two LBSs will produce ambiguity. Reference spec Information technology - SCSI Block Commands – 4 (SBC-4) ISO/IEC 14776-324:201x BSR INCITS 506:201x 5.50 WRITE SAME (10) command The WRITE SAME (10) command (see table 145) requests that the device server **transfer a single logical block** from the Data-Out Buffer and for each LBA in the specified range of LBAs: From mboxrd@z Thu Jan 1 00:00:00 1970 From: "zhangxiaoxu (A)" Subject: Re: block: Fix a WRITE SAME BUG_ON Date: Thu, 31 Jan 2019 08:58:24 +0800 Message-ID: References: <20190125021107.4595-1-zhangxiaoxu5@huawei.com> <20190128221441.GA24102@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8"; Format="flowed" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: Content-Language: en-US List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com To: John Dorminy , "Martin K. Petersen" Cc: axboe@kernel.dk, linux-block@vger.kernel.org, dm-devel@redhat.com, Alasdair G Kergon , Mike Snitzer List-Id: dm-devel.ids CgpPbiAxLzMwLzIwMTkgMTA6MDggUE0sIEpvaG4gRG9ybWlueSB3cm90ZToKPiBBbHRlcm5hdGVs eSwgY291bGQgcG9zc2libHkgV1JJVEVfU0FNRSBiaW9zIGJlIGFjY2VwdGVkIHdpdGggdGhlCj4g bWluaW11bSBzZWN0b3Igc2l6ZSBvZiB0aGUgc3RhY2sgcmF0aGVyIHRoYW4gdGhlIG1heCwgZS5n LiA1MTIgaW4gdGhpcwo+IGV4YW1wbGUgcmF0aGVyIHRoYW4gNGs/IFRoZXknZCBuZWVkIHRvIGhh dmUgYSBncmFudWxhcml0eSBvZiB0aGUKPiBsYXJnZXIgc2VjdG9yIHNpemUsIHRob3VnaCwgcHJl c3VtYWJpbHkgbmVjZXNzaXRhdGluZyBuZXcgcXVldWUgbGltaXRzCj4gd3JpdGVfc2FtZV97Z3Jh bnVsYXJpdHksYmxvY2tfc2l6ZX0sIHdoaWNoIG1pZ2h0IGJlIHRvbyBtdWNoIHdvcmsuIEZvcgo+ IGRldmljZXMgd2l0aCBiaWdnZXIgc2VjdG9ycywgdGhlIGJsb2NrIGxheWVyIG9yIERNIHdvdWxk IG5lZWQgdG8KPiBleHBhbmQgdGhlIHNtYWxsLXNlY3RvciBwYXlsb2FkIHRvIGFuIGFwcHJvcHJp YXRlIGxhcmdlci1zZWN0b3IKPiBwYXlsb2FkLCBidXQgaXQgd291bGQgcHJlc2VydmUgdGhlIGFi aWxpdHkgdG8gdXNlIFdSSVRFX1NBTUUgd2l0aAo+IG5vbi16ZXJvIHBheWxvYWRzLgo+IAo+IChJ IHVzZSBXUklURV9TQU1FIHRvIGZpbGwgZGV2aWNlcyB3aXRoIGEgcGFydGljdWxhciBwYXR0ZXJu IGluIG9yZGVyCj4gdG8gY2F0Y2ggZmFpbHVyZXMgdG8gaW5pdGlhbGl6ZSBkaXNrIHN0cnVjdHVy ZXMgYXBwcm9wcmlhdGVseSwKPiBwZXJzb25hbGx5LCBidXQgaXQncyBqdXN0IGZvciBjb252ZW5p ZW5jZS9zcGVlZC4pCkkgdGhpbmsgdHdvIExCU3Mgd2lsbCBwcm9kdWNlIGFtYmlndWl0eS4KUmVm ZXJlbmNlIHNwZWMKCUluZm9ybWF0aW9uIHRlY2hub2xvZ3kgLQoJU0NTSSBCbG9jayBDb21tYW5k cyDigJMgNCAoU0JDLTQpCglJU08vSUVDIDE0Nzc2LTMyNDoyMDF4CglCU1IgSU5DSVRTIDUwNjoy MDF4CjUuNTAgV1JJVEUgU0FNRSAoMTApIGNvbW1hbmQKVGhlIFdSSVRFIFNBTUUgKDEwKSBjb21t YW5kIChzZWUgdGFibGUgMTQ1KSByZXF1ZXN0cyB0aGF0IHRoZSBkZXZpY2Ugc2VydmVyCioqdHJh bnNmZXIgYSBzaW5nbGUgbG9naWNhbCBibG9jayoqIGZyb20gdGhlIERhdGEtT3V0IEJ1ZmZlciBh bmQgZm9yIGVhY2ggTEJBIGluCnRoZSBzcGVjaWZpZWQgcmFuZ2Ugb2YgTEJBczoKCgoKCi0tCmRt LWRldmVsIG1haWxpbmcgbGlzdApkbS1kZXZlbEByZWRoYXQuY29tCmh0dHBzOi8vd3d3LnJlZGhh dC5jb20vbWFpbG1hbi9saXN0aW5mby9kbS1kZXZlbA==