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=-17.0 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 6B40CC433E6 for ; Sat, 9 Jan 2021 10:47:20 +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 2CE3823A23 for ; Sat, 9 Jan 2021 10:47:20 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2CE3823A23 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=wG03pQQYT9FEyK6AaengK4dfu28g6V8h39p3QAFLmOo=; b=sZU/5JnZeL3RpkmunW9hvQJrv PgECHpZjOlzndTugcdGTYI9zCxtZDtoPzICuNLZy1Z2Q9zLUKy+u6gN+0jhCCal4tj5JMHvl2FWjv EbKcl8272/gwxEqJVeJcjURbUNQ89GSGoCCI8zpXevE1GesMxa+zUkXUnwm/IMflpTZ3NEISAZ4aM Td+RaxeYlb5tqPsib0olJlhBhAb1Urvq5AD9BvRcI7fRk3scfagnfoIXiMbo8E+upOgVNZoYULZM5 BuUgjAyPYVERYgYEfOX+o62Eyke8bHAtkISpiEBLy85DGQZoH9ajj7Lbo0N9fSnHYN4BinIPKV9Zo EZjlmhzww==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kyBlr-00048F-BN; Sat, 09 Jan 2021 10:46:59 +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 1kyBlg-00044p-Hy for linux-nvme@merlin.infradead.org; Sat, 09 Jan 2021 10:46:48 +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=OuO8kXBwOVg2a0qlGOHd+KBfCRFHK5StyY10tKFHVS8=; b=VeZFfshSf9Ix0EcE41evKramMP jn5vZju+vCViJE/nGVWD9jxUQ4zuFVyTiarcua3S0nKzo7UtPQ3qIvoDASsUtzBegY+tOdk/8xOJU SYiCsPCW7JhSvmDRJr6Lorz+5qbHCPXUzOT+g++UB3pV/FLKrxmLDRt7hyQoDNuep1RFkMyXYIeP3 NbSdIibjh9ZG/rL8H6VX4+ebq8g12ZsuZ8yV1igsjWwJ+tzmCwWzJWONL0ss00jAta8hq2Gpvoi6u KxUiqhoHwmWMvQ0hEVuPfAn7NQKRcax/09Nx9Mv0b82q3hBiycqDf9GEL376cuzLHC4Vov+fP779e nSUoU8fw==; Received: from [2001:4bb8:19b:e528:4197:a20:99de:e7b0] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1kyBl7-000TC6-Dn; Sat, 09 Jan 2021 10:46:20 +0000 From: Christoph Hellwig To: Jens Axboe Subject: [PATCH 4/6] block: propagate BLKROSET on the whole device to all partitions Date: Sat, 9 Jan 2021 11:42:52 +0100 Message-Id: <20210109104254.1077093-5-hch@lst.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20210109104254.1077093-1-hch@lst.de> References: <20210109104254.1077093-1-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 e70bdc9b0893c1..10c76320510fef 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1658,8 +1658,7 @@ 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