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=-15.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED 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 A68E4C4361B for ; Tue, 8 Dec 2020 10:22:47 +0000 (UTC) Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [63.128.21.124]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 2AC4023A9B for ; Tue, 8 Dec 2020 10:22:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2AC4023A9B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=tempfail smtp.mailfrom=dm-devel-bounces@redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607422965; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:list-id:list-help: list-unsubscribe:list-subscribe:list-post; bh=Bf3JtLvimu9WWYlo5QGeMYJUn8rIuhsy43X38M6K70M=; b=JEhf71otn8bFpDVIuoLCKtJoAyW0fDfaJTzB0FSqR+xVBEOxhzDEgFRd5djP35/U7etwWG ms7VMRj2EZT9KV7cbC24ZGjkkuRN/kFZBmutJpi3B5j31KcX1C813QyrC0+5SgqLpXfd6R xL2/5YQwGcK7IAOzVNwGa3yb0rrSMFo= 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-44-KFc12HAUOLKdkipLlZTLXw-1; Tue, 08 Dec 2020 05:22:43 -0500 X-MC-Unique: KFc12HAUOLKdkipLlZTLXw-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 2C77C1005504; Tue, 8 Dec 2020 10:22:39 +0000 (UTC) Received: from colo-mx.corp.redhat.com (colo-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.21]) by smtp.corp.redhat.com (Postfix) with ESMTPS id B82655C1A1; Tue, 8 Dec 2020 10:22:38 +0000 (UTC) Received: from lists01.pubmisc.prod.ext.phx2.redhat.com (lists01.pubmisc.prod.ext.phx2.redhat.com [10.5.19.33]) by colo-mx.corp.redhat.com (Postfix) with ESMTP id 6F94D4E58E; Tue, 8 Dec 2020 10:22:37 +0000 (UTC) Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.phx2.redhat.com [10.5.11.11]) by lists01.pubmisc.prod.ext.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id 0B8AMYPP031855 for ; Tue, 8 Dec 2020 05:22:34 -0500 Received: by smtp.corp.redhat.com (Postfix) id F1B131346F; 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 Message-ID: <20201208102211.GC1202995@T590> References: <20201207131918.2252553-1-hch@lst.de> <20201207131918.2252553-4-hch@lst.de> MIME-Version: 1.0 In-Reply-To: <20201207131918.2252553-4-hch@lst.de> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 X-loop: dm-devel@redhat.com 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 Subject: Re: [dm-devel] [PATCH 3/6] block: add a hard-readonly flag to struct gendisk X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit 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 -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel