From patchwork Sat Jan 9 10:42:51 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 12008115 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=-16.8 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,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 ABD61C433DB for ; Sat, 9 Jan 2021 10:48:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 822FC23A1E for ; Sat, 9 Jan 2021 10:48:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726843AbhAIKsV (ORCPT ); Sat, 9 Jan 2021 05:48:21 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54590 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726541AbhAIKsU (ORCPT ); Sat, 9 Jan 2021 05:48:20 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 532B0C06179F; Sat, 9 Jan 2021 02:47:40 -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=Txv6EQ9gPaV4zZ3R/07xKBssgYf1qHOamsO3WQ5Virc=; b=vdL7EDVfs1JBqD2gJqh+nMGPOM 8AGpKaHriyLHGo359OoH80hrREqezfsuIBBS7Uf2xnuQi0AFEb3EVZPPZAANHknbAZLuEYfnpG8Dy UX0rLLw2ZwnysN71+JB2n2BabuKfaDmGgeKydp4PgjSa6dbaU30VIxwygB3R3kImZ/JjtKnPdZXd0 0xupqMbuH6OEflj3aJmeabtMy6uo+ZbCMIYdWdsizOX2hSAHc2NkB4sAzzgLgpgoj/0kKyZWQvKCl ZtEkAhLNwgP4s32pizfLIN3k7xGoW2y9svoCxpV0aMQKdb2Es92GK6jX771EtEk4bYCLkkJqGQA1e h12XtSzA==; 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 1kyBkd-000TAI-LX; Sat, 09 Jan 2021 10:45:53 +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, Ming Lei , Hannes Reinecke Subject: [PATCH 3/6] block: add a hard-readonly flag to struct gendisk Date: Sat, 9 Jan 2021 11:42:51 +0100 Message-Id: <20210109104254.1077093-4-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 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: Ming Lei Reviewed-by: Martin K. Petersen Reviewed-by: Hannes Reinecke --- block/blk-core.c | 4 +--- block/genhd.c | 33 +++++++++++++++++++-------------- block/partitions/core.c | 3 +-- include/linux/genhd.h | 6 ++++-- 4 files changed, 25 insertions(+), 21 deletions(-) diff --git a/block/blk-core.c b/block/blk-core.c index 7663a9b94b8002..08ff8ca325296e 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -694,9 +694,7 @@ static inline bool should_fail_request(struct block_device *part, static inline bool bio_check_ro(struct bio *bio, struct block_device *part) { - const int op = bio_op(bio); - - if (part->bd_read_only && op_is_write(op)) { + if (op_is_write(bio_op(bio)) && bdev_read_only(part)) { 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 4f90f80d7aa76d..e70bdc9b0893c1 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1634,27 +1634,32 @@ 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 e7d776db803b12..168d5906077cfd 100644 --- a/block/partitions/core.c +++ b/block/partitions/core.c @@ -195,7 +195,7 @@ 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, @@ -361,7 +361,6 @@ 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 809aaa32d53cba..a62ccbfac54b48 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -163,6 +163,7 @@ 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; @@ -249,11 +250,12 @@ 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);