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=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY autolearn=no 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 387DAC35247 for ; Wed, 5 Feb 2020 02:30:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 05D1A21744 for ; Wed, 5 Feb 2020 02:30:22 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="BYwAMglq" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727887AbgBECaV (ORCPT ); Tue, 4 Feb 2020 21:30:21 -0500 Received: from userp2130.oracle.com ([156.151.31.86]:35634 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727674AbgBECaV (ORCPT ); Tue, 4 Feb 2020 21:30:21 -0500 Received: from pps.filterd (userp2130.oracle.com [127.0.0.1]) by userp2130.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 0152O7Kn194564; Wed, 5 Feb 2020 02:30:08 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=to : cc : subject : from : references : date : in-reply-to : message-id : mime-version : content-type; s=corp-2019-08-05; bh=Zg0+DiwI/K8/E+WQiW0JH09laZKD8erQQWdHWq52yFM=; b=BYwAMglqvTSNmTV4K9POC+0F49mrfGG8uo8WdQb4tzi3Npk5NQjSuWI7q3HE1y2KQPX0 6a5urVogIHmhvy1g6eKXtWCnFkoorkHQMS683MwCYedH4Dw5Cg8Mlyb1LM/tev5hbUWI aaeumizI5aCinFoaTty9BL3WBLG45tUPLNhDfCl0+FWxzZ1Sk9Blm56I+/vvpRjM/EDh wwjzSMy++ED6nJcHmdV31h11RZ3qndkjfvXoBuV9fO+pmCV5gMof6wlFimwEGd1SXFHO 7cNV/fPM2/4B5Gjj3TpfOWyoZaxdBvfjcAOdbDolGc59HK2pRnX589PSaxB0WEjC7hRh 2A== Received: from aserp3030.oracle.com (aserp3030.oracle.com [141.146.126.71]) by userp2130.oracle.com with ESMTP id 2xykbp09kk-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 05 Feb 2020 02:30:08 +0000 Received: from pps.filterd (aserp3030.oracle.com [127.0.0.1]) by aserp3030.oracle.com (8.16.0.27/8.16.0.27) with SMTP id 0152OFK3188262; Wed, 5 Feb 2020 02:30:07 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3030.oracle.com with ESMTP id 2xykbqnh2m-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 05 Feb 2020 02:30:07 +0000 Received: from abhmp0017.oracle.com (abhmp0017.oracle.com [141.146.116.23]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 0152U5YX025424; Wed, 5 Feb 2020 02:30:05 GMT Received: from ca-mkp.ca.oracle.com (/10.159.214.123) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 04 Feb 2020 18:30:04 -0800 To: AlexChen Cc: , , Bart Van Assche , , , , Subject: Re: [PATCH V2] scsi: add a new flag to set whether SCSI disks support WRITE_SAME_16 by default From: "Martin K. Petersen" Organization: Oracle Corporation References: <5E28118F.3070706@huawei.com> <5E3520A7.5030501@huawei.com> Date: Tue, 04 Feb 2020 21:30:02 -0500 In-Reply-To: <5E3520A7.5030501@huawei.com> (AlexChen's message of "Sat, 1 Feb 2020 14:54:31 +0800") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.1.92 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9521 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=0 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2002050018 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9521 signatures=668685 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1911140001 definitions=main-2002050018 Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org Hi Alex, > When the SCSI device is initialized, check whether it supports > WRITE_SAME_16 or WRITE_SAME_10 in the sd_read_write_same(). If the > back-end storage device does not support queries, it will not set > sdkp->ws16 as 1. Your proposed code change is fine and to the point. However, I'd like to understand why you are adding a workaround to the kernel instead of fixing the affected device? Implementing support for either WRITE SAME(10) or REPORT SUPPORTED OPERATION CODES is easy. And the latter in particular is beneficial for discovering several other SCSI protocol features. It's a good command to support in general. Also, we generally don't add features to the kernel without any users. So if you add a blacklist flag, I would expect to see a set of device strings to be added to scsi_devinfo.c. -- Martin K. Petersen Oracle Linux Engineering