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=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 2C28CC4167B for ; Tue, 8 Dec 2020 10:24:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E95CA23A9C for ; Tue, 8 Dec 2020 10:24:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728793AbgLHKYH (ORCPT ); Tue, 8 Dec 2020 05:24:07 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:29450 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728312AbgLHKYH (ORCPT ); Tue, 8 Dec 2020 05:24:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1607422960; 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=WFp3m/RcQ/90BClGrz1PtR9RXY2a1SVApEJ5pM7duiBwMQ9ZxzvzAOabKfF/laJObQgj5f 0MPS2dFOq/i3L/BmJ1akI8/otPPNiCCxzd5WZGk5TDUvEa8LYQw7FhVJfpqE59MCFym3WO 3pS7P9ywUF/mApQlU1/DFTZFqTN7F+Y= 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 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, Hannes Reinecke 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-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201207131918.2252553-4-hch@lst.de> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.11 Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.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