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=-13.8 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 autolearn=unavailable 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 F4190C4167B for ; Tue, 8 Dec 2020 10:22:47 +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 990A023AA7 for ; Tue, 8 Dec 2020 10:22:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 990A023AA7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=9pc1ieZAO8+uczHwl/KlIoE+dFUdHxJp/0MPNwRewAo=; b=OjWvPMXX2hEVKaGgoicI47Me5 PFBv8bOPLGYtzSmhy6hV06MXqbb1P0riTOXyy68v00kljGKjCHwO8B/O8QHJJfhSYNhdVsVxYATt9 CNgzMxRFqMfq9j0N8IF/s+PKhaxZBb/rIM7cw+GZa2n8VFmfRYfWfPr687VgmYfCoJWOrLzqII5xj qUkmqpNyHfZSxizqCXNtqVHLpWbT9H37TRBUl2cX79yBzNoZW2LXcx6eleABc8hufU4vSI3VSm/km pWgrZw7gKpWOZPMixeLaThSbo+yFZwkIHWU+HAh0S1w1VHn7dXE0eH0IAUMsWdc0+6hHb43qSOvSD MARFQlOMQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kma8o-0002Cc-5K; Tue, 08 Dec 2020 10:22:42 +0000 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kma8l-0002C8-LJ for linux-nvme@lists.infradead.org; Tue, 08 Dec 2020 10:22:40 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607422958; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=CbRwXof5BfleheY9ylmF59cZ8VjqZIDWfRUHUpV3i68=; b=X9n+aHCSpDQudSgBodpLHQveaPVmfxYjf0sXWTMqVSt61ng6vQH3P5Sg+IUsvvRfE673af qNUKZJa9K11wS5tRA0WAw8vxWOW9IT6KYWFyNxSH41sjYUPwPcKXnLgieVVon7TAG8iQW8 lJmmuSz6GRjV8k441euadb6frOpBFAM= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-593-BAOAnsQvOaSGOX-DanZ9aA-1; Tue, 08 Dec 2020 05:22:35 -0500 X-MC-Unique: BAOAnsQvOaSGOX-DanZ9aA-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id F36BC107ACE6; Tue, 8 Dec 2020 10:22:33 +0000 (UTC) Received: from T590 (ovpn-12-237.pek2.redhat.com [10.72.12.237]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 3F6B260636; Tue, 8 Dec 2020 10:22:15 +0000 (UTC) Date: Tue, 8 Dec 2020 18:22:11 +0800 From: Ming Lei To: Christoph Hellwig Subject: Re: [PATCH 3/6] block: add a hard-readonly flag to struct gendisk Message-ID: <20201208102211.GC1202995@T590> References: <20201207131918.2252553-1-hch@lst.de> <20201207131918.2252553-4-hch@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201207131918.2252553-4-hch@lst.de> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201208_052239_753188_D9DE3B7D X-CRM114-Status: GOOD ( 32.87 ) 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: Jens Axboe , 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, Hannes Reinecke 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 On Mon, Dec 07, 2020 at 02:19:15PM +0100, Christoph Hellwig wrote: > Commit 20bd1d026aac ("scsi: sd: Keep disk read-only when re-reading > partition") addressed a long-standing problem with user read-only > policy being overridden as a result of a device-initiated revalidate. > The commit has since been reverted due to a regression that left some > USB devices read-only indefinitely. > > To fix the underlying problems with revalidate we need to keep track > of hardware state and user policy separately. > > The gendisk has been updated to reflect the current hardware state set > by the device driver. This is done to allow returning the device to > the hardware state once the user clears the BLKROSET flag. > > The resulting semantics are as follows: > > - If BLKROSET sets a given partition read-only, that partition will > remain read-only even if the underlying storage stack initiates a > revalidate. However, the BLKRRPART ioctl will cause the partition > table to be dropped and any user policy on partitions will be lost. > > - If BLKROSET has not been set, both the whole disk device and any > partitions will reflect the current write-protect state of the > underlying device. > > Based on a patch from Martin K. Petersen . > > Reported-by: Oleksii Kurochko > Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201221 > Signed-off-by: Christoph Hellwig > Reviewed-by: Hannes Reinecke > --- > block/blk-core.c | 2 +- > block/genhd.c | 33 +++++++++++++++++++-------------- > block/partitions/core.c | 3 +-- > include/linux/genhd.h | 6 ++++-- > 4 files changed, 25 insertions(+), 19 deletions(-) > > diff --git a/block/blk-core.c b/block/blk-core.c > index ad041e903b0a8f..ecd68415c6acad 100644 > --- a/block/blk-core.c > +++ b/block/blk-core.c > @@ -693,7 +693,7 @@ static inline bool should_fail_request(struct block_device *part, > > static inline bool bio_check_ro(struct bio *bio) > { > - if (op_is_write(bio_op(bio)) && bio->bi_bdev->bd_read_only) { > + if (op_is_write(bio_op(bio)) && bdev_read_only(bio->bi_bdev)) > char b[BDEVNAME_SIZE]; > > if (op_is_flush(bio->bi_opf) && !bio_sectors(bio)) > diff --git a/block/genhd.c b/block/genhd.c > index c87013879b8650..878f94727aaa96 100644 > --- a/block/genhd.c > +++ b/block/genhd.c > @@ -1425,27 +1425,32 @@ static void set_disk_ro_uevent(struct gendisk *gd, int ro) > kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp); > } > > -void set_disk_ro(struct gendisk *disk, int flag) > +/** > + * set_disk_ro - set a gendisk read-only > + * @disk: gendisk to operate on > + * @ready_only: %true to set the disk read-only, %false set the disk read/write > + * > + * This function is used to indicate whether a given disk device should have its > + * read-only flag set. set_disk_ro() is typically used by device drivers to > + * indicate whether the underlying physical device is write-protected. > + */ > +void set_disk_ro(struct gendisk *disk, bool read_only) > { > - struct disk_part_iter piter; > - struct block_device *part; > - > - if (disk->part0->bd_read_only != flag) { > - set_disk_ro_uevent(disk, flag); > - disk->part0->bd_read_only = flag; > + if (read_only) { > + if (test_and_set_bit(GD_READ_ONLY, &disk->state)) > + return; > + } else { > + if (!test_and_clear_bit(GD_READ_ONLY, &disk->state)) > + return; > } > - > - disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); > - while ((part = disk_part_iter_next(&piter))) > - part->bd_read_only = flag; > - disk_part_iter_exit(&piter); > + set_disk_ro_uevent(disk, read_only); > } > - > EXPORT_SYMBOL(set_disk_ro); > > int bdev_read_only(struct block_device *bdev) > { > - return bdev->bd_read_only; > + return bdev->bd_read_only || > + test_bit(GD_READ_ONLY, &bdev->bd_disk->state); > } > EXPORT_SYMBOL(bdev_read_only); Maybe one inline version can be added for fast path(bio_check_ro()), and the approach is good: Reviewed-by: Ming Lei -- Ming _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme