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=-16.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT 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 D08C6C4361B for ; Tue, 8 Dec 2020 16:37:27 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 9506C233CF for ; Tue, 8 Dec 2020 16:37:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9506C233CF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To:Message-Id:Date: Subject:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=QFPHk/5e73HVpbePRcq09wsdDkaxTT41BPLTbUgsaPM=; b=RbTF5SorOczLHrGG9jNVooNJT wh6a7gQuftEj+XD2yGrPBGrXNuJxJG6Cg0/0o6oQDJXTMkYTAocMNHpUFIs8P7G+0cAcxiQGIUEUH KbJzbHuW14JHC5IhGdIWO7t8MySzdhOL6L1f/AgUwEldgulCVfOVZsnOK/JA9dnOF9aYIFZpVIgsh VrjSGVUSTGfmyEPDqQC8q4yoYEnZfnuShqnV3JkpGpFrezkHaFJh1HcE2vgzd3MoUBRjqfhfT4k3S rVZT5OUxGQdPT7p4QvkQh7Ev5oTUV6hiPe2ecTwwCUW9/nH5aKRcd3Uv9/nWAWXZAT89mky1DHf5G J7OZSAYGw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmfzQ-0002Cy-Fk; Tue, 08 Dec 2020 16:37:24 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmfzJ-00028b-OW for linux-nvme@merlin.infradead.org; Tue, 08 Dec 2020 16:37:17 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Content-Transfer-Encoding:MIME-Version: References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To: Content-Type:Content-ID:Content-Description; bh=elpIgX+cTsb2dqzbwyG4mhhxmB2j6M8UmSJFUU3cmP0=; b=ku/Ut2+yV4kFeNDDzU3/Gz0gty xKg3I1ZYaBfKuo8vMnrV/wa+5sdvtI2PqU0AYrGf3mU7w+pj9DFVIZWt3CAk70dXi2BwusOpNCG97 hbpVaV3f1thTtnt571Ucm6mf+53WHPZHNQlOe9gwFtSBdD8cPPbv+dNbWqjk/vDXIyfcN/+wKNl42 Vjm6YaZj9hVudn2S1PgeVPwyfE5mcCz1aSKFDfPTB0Z8Pu7jeRdKLwRKeGF80Or+HvuJkf79iNwd5 fHIcakd96svG/ThN9KKezO5QqtECF8R9/HMTrFCyX+7HJ+Wg13U+eZPPrQQeISP6RjKmr4k+nKHay bWj2U4Tg==; Received: from [2001:4bb8:188:f36:7a30:8a2b:aea3:231b] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmfzI-0001Nu-He; Tue, 08 Dec 2020 16:37:16 +0000 From: Christoph Hellwig To: Jens Axboe Subject: [PATCH 4/6] block: propagate BLKROSET on the whole device to all partitions Date: Tue, 8 Dec 2020 17:28:27 +0100 Message-Id: <20201208162829.2424563-5-hch@lst.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201208162829.2424563-1-hch@lst.de> References: <20201208162829.2424563-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sagi Grimberg , Mike Snitzer , Oleksii Kurochko , Dongsheng Yang , linux-block@vger.kernel.org, dm-devel@redhat.com, linux-nvme@lists.infradead.org, "Martin K . Petersen" , Ilya Dryomov , ceph-devel@vger.kernel.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org Change the policy so that a BLKROSET on the whole device also affects partitions. To quote Martin K. Petersen: 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. The existing behavior is inconsistent in the sense that doing: # blockdev --setro /dev/sda # echo foo > /dev/sda1 permits writes. But: # blockdev --setro /dev/sda # echo foo > /dev/sda1 doesn't. And a subsequent: # blockdev --setrw /dev/sda # echo foo > /dev/sda1 doesn't work either since sda1's read-only policy has been inherited from the whole-disk device. You need to do: # blockdev --rereadpt after setting the whole-disk device rw to effectuate the same change on the partitions, otherwise they are stuck being read-only indefinitely. However, setting the read-only policy on a partition does *not* require the revalidate step. As a matter of fact, doing the revalidate will blow away the policy setting you just made. So the user needs to take different actions depending on whether they are trying to read-protect a whole-disk device or a partition. Despite using the same ioctl. That is really confusing. I have lost count how many times our customers have had data clobbered because of ambiguity of the existing whole-disk device policy. The current behavior violates the principle of least surprise by letting the user think they write protected the whole disk when they actually didn't. Suggested-by: Martin K. Petersen Signed-off-by: Christoph Hellwig Reviewed-by: Martin K. Petersen --- block/genhd.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index d9f989c1514123..6e51ecb9280aca 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1656,8 +1656,7 @@ EXPORT_SYMBOL(set_disk_ro); int bdev_read_only(struct block_device *bdev) { - return bdev->bd_read_only || - test_bit(GD_READ_ONLY, &bdev->bd_disk->state); + return bdev->bd_read_only || get_disk_ro(bdev->bd_disk); } EXPORT_SYMBOL(bdev_read_only); -- 2.29.2 _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme