From patchwork Mon Dec 7 13:19:15 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 339195 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=-16.7 required=3.0 tests=BAYES_00,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=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 70837C4361B for ; Mon, 7 Dec 2020 13:23:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3E46123436 for ; Mon, 7 Dec 2020 13:23:09 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726206AbgLGNWh (ORCPT ); Mon, 7 Dec 2020 08:22:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57806 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726136AbgLGNWg (ORCPT ); Mon, 7 Dec 2020 08:22:36 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 226CFC0613D1; Mon, 7 Dec 2020 05:21:56 -0800 (PST) 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=krDTBkn6Fvuu48M0DAGcGJkX1Vh5F9ONgeip8Q2IlTU=; b=oW0FG815AKU0SAD/baFOidcQes s58HY3Sur/51RswtRWwhUaflobxd+ahS2yP3JDCxkvSW5GSaPLOhDGsm/v2iLAdcna7ago7OcPTYN f0TB3An9LbW+c3uvjYjK70N6ZpI1g72xEqzLo2hdVD94CONyoAYezeTSK14NoxaoenDQhzHXp0Hjr vXEW77v5Ax9IeVG6EK0OZBXMvW5gtq6HPPvi0VC/IMCT3l4ndpmaFCZC4hGZDJLcA9LWrkYDuvQW6 2B4OEkO8NA+PymvinANn4TcNKPQ+JsnVladewZEBexBOKcwLuRA84rpgyeWjasXiAJzyBLG7gsKVO QdXGzGsw==; Received: from [2001:4bb8:188:f36:4fd9:254f:b3b5:5284] (helo=localhost) by casper.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1kmGSM-0006P8-8i; Mon, 07 Dec 2020 13:21:34 +0000 From: Christoph Hellwig To: Jens Axboe Cc: "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: [PATCH 3/6] block: add a hard-readonly flag to struct gendisk Date: Mon, 7 Dec 2020 14:19:15 +0100 Message-Id: <20201207131918.2252553-4-hch@lst.de> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201207131918.2252553-1-hch@lst.de> References: <20201207131918.2252553-1-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 Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org 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 Reviewed-by: Martin K. Petersen Reviewed-by: Ming Lei --- 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); diff --git a/block/partitions/core.c b/block/partitions/core.c index c88f03ddaefe29..278e2419b163bb 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -194,7 +194,7 @@ static ssize_t part_start_show(struct device *dev, static ssize_t part_ro_show(struct device *dev, struct device_attribute *attr, char *buf) { - return sprintf(buf, "%d\n", dev_to_bdev(dev)->bd_read_only); + return sprintf(buf, "%d\n", bdev_read_only(dev_to_bdev(dev))); } static ssize_t part_alignment_offset_show(struct device *dev, @@ -348,7 +348,6 @@ static struct block_device *add_partition(struct gendisk *disk, int partno, bdev->bd_start_sect = start; bdev_set_nr_sectors(bdev, len); - bdev->bd_read_only = get_disk_ro(disk); if (info) { err = -ENOMEM; diff --git a/include/linux/genhd.h b/include/linux/genhd.h index e8821bfe07b955..f364619092cca0 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -152,6 +152,7 @@ struct gendisk { int flags; unsigned long state; #define GD_NEED_PART_SCAN 0 +#define GD_READ_ONLY 1 struct kobject *slave_dir; struct timer_rand_state *random; @@ -238,11 +239,12 @@ static inline void add_disk_no_queue_reg(struct gendisk *disk) extern void del_gendisk(struct gendisk *gp); extern struct block_device *bdget_disk(struct gendisk *disk, int partno); -extern void set_disk_ro(struct gendisk *disk, int flag); +void set_disk_ro(struct gendisk *disk, bool read_only); static inline int get_disk_ro(struct gendisk *disk) { - return disk->part0->bd_read_only; + return disk->part0->bd_read_only || + test_bit(GD_READ_ONLY, &disk->state); } extern void disk_block_events(struct gendisk *disk);