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=-7.2 required=3.0 tests=BAYES_00,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 84025C63777 for ; Thu, 3 Dec 2020 04:08:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 39D6721D91 for ; Thu, 3 Dec 2020 04:08:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727846AbgLCEHt (ORCPT ); Wed, 2 Dec 2020 23:07:49 -0500 Received: from aserp2120.oracle.com ([141.146.126.78]:51510 "EHLO aserp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726071AbgLCEHr (ORCPT ); Wed, 2 Dec 2020 23:07:47 -0500 Received: from pps.filterd (aserp2120.oracle.com [127.0.0.1]) by aserp2120.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0B3457vJ020751; Thu, 3 Dec 2020 04:06:45 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=to : cc : subject : from : message-id : references : date : in-reply-to : mime-version : content-type; s=corp-2020-01-29; bh=Oww/8iFoOsE1zM3fFYoD3Oq4k1GA5uwflIdMRTl3mec=; b=fyla7Dqb2gXhO/cJjdl0yvSvOSu/pagItggvc1t2wSrUk/mP4xAnnh/0IhPPdR0aHoKe Ibni9NreZWk+zLuvcfCa9UZ9Td3PC0ZwRbDIBKx8hDDmtU9MxPotY8+daPljUXKy/0TM UaOQPNmirWNqgXI/lKF57lDeYMpkYIdC9w88WBiGgcCTHLSP4D3eZsEqh8M5orT9vFU+ 3J+CzrRyLqjh/Qe6oMbo3xP/R5oKlGlWp/1tjaNn3Ip0RGIGJw0oiZMFx543Fsil29AS pWLwKI7X8Uhs9ddrmZs4/E2NU7HFDKup2QFJ/eT8YkX9R/GtWlIEP+mjI/J6T8uSiuIw rQ== Received: from aserp3020.oracle.com (aserp3020.oracle.com [141.146.126.70]) by aserp2120.oracle.com with ESMTP id 353egkuqqv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 03 Dec 2020 04:06:45 +0000 Received: from pps.filterd (aserp3020.oracle.com [127.0.0.1]) by aserp3020.oracle.com (8.16.0.42/8.16.0.42) with SMTP id 0B340D7O085693; Thu, 3 Dec 2020 04:04:44 GMT Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by aserp3020.oracle.com with ESMTP id 3540f19ag8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Thu, 03 Dec 2020 04:04:44 +0000 Received: from abhmp0006.oracle.com (abhmp0006.oracle.com [141.146.116.12]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id 0B344aX8004987; Thu, 3 Dec 2020 04:04:38 GMT Received: from ca-mkp.ca.oracle.com (/10.159.214.123) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 02 Dec 2020 20:04:36 -0800 To: Christoph Hellwig Cc: Jens Axboe , "Martin K . Petersen" , Oleksii Kurochko , Sagi Grimberg , Mike Snitzer , Ilya Dryomov , Dongsheng Yang , ceph-devel@vger.kernel.org, dm-devel@redhat.com, linux-block@vger.kernel.org, linux-nvme@lists.infradead.org Subject: Re: [PATCH 1/4] block: add a hard-readonly flag to struct gendisk From: "Martin K. Petersen" Organization: Oracle Corporation Message-ID: References: <20201129181926.897775-1-hch@lst.de> <20201129181926.897775-2-hch@lst.de> Date: Wed, 02 Dec 2020 23:04:33 -0500 In-Reply-To: <20201129181926.897775-2-hch@lst.de> (Christoph Hellwig's message of "Sun, 29 Nov 2020 19:19:23 +0100") MIME-Version: 1.0 Content-Type: text/plain X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9823 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 malwarescore=0 phishscore=0 suspectscore=1 bulkscore=0 spamscore=0 adultscore=0 mlxlogscore=999 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012030021 X-Proofpoint-Virus-Version: vendor=nai engine=6000 definitions=9823 signatures=668682 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 mlxscore=0 bulkscore=0 suspectscore=1 phishscore=0 mlxlogscore=999 lowpriorityscore=0 malwarescore=0 priorityscore=1501 spamscore=0 impostorscore=0 clxscore=1011 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2009150000 definitions=main-2012030022 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org Hi Christoph! > - If BLKROSET is used to set a whole-disk device read-only, any > partitions will end up in a read-only state until the user > explicitly clears the flag. This no longer appears to be the case with your tweak. It's very common for database folks to twiddle the read-only state of block devices and partitions. I know that our users will find it very counter-intuitive that setting /dev/sda read-only won't prevent writes to /dev/sda1. > int bdev_read_only(struct block_device *bdev) > { > if (!bdev) > return 0; > - return bdev->bd_read_only; > + return bdev->bd_read_only || > + test_bit(GD_READ_ONLY, &bdev->bd_disk->state); > } I suggest doing bd->bd_read_only || get_disk_ro(...) here. That does take part0 into account. > static inline int get_disk_ro(struct gendisk *disk) > { > - return disk->part0->bd_read_only; > + return disk->part0->bd_read_only || > + test_bit(GD_READ_ONLY, &disk->state); > } > > extern void disk_block_events(struct gendisk *disk); -- Martin K. Petersen Oracle Linux Engineering