From patchwork Wed Feb 13 02:57:17 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Martin K. Petersen" X-Patchwork-Id: 10809033 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id F24651575 for ; Wed, 13 Feb 2019 02:57:35 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E26A32C06F for ; Wed, 13 Feb 2019 02:57:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id D68882C075; Wed, 13 Feb 2019 02:57:35 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4399D2C070 for ; Wed, 13 Feb 2019 02:57:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388230AbfBMC5d (ORCPT ); Tue, 12 Feb 2019 21:57:33 -0500 Received: from userp2120.oracle.com ([156.151.31.85]:44064 "EHLO userp2120.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732214AbfBMC51 (ORCPT ); Tue, 12 Feb 2019 21:57:27 -0500 Received: from pps.filterd (userp2120.oracle.com [127.0.0.1]) by userp2120.oracle.com (8.16.0.27/8.16.0.27) with SMTP id x1D2sJMx043653; Wed, 13 Feb 2019 02:57:24 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : in-reply-to : references : mime-version : content-transfer-encoding; s=corp-2018-07-02; bh=n8ZhwwLZ+O77rNHP76IlYQc5TNriHiGwASwyYHk5D7g=; b=FEwoQyaMcP9mOwhSSqtKLm8RttU+SA7zj/Oi8pEckxAK/2pXLFHr9JZnYRQz3Dw/MEox GjAr9k/iHCVlSKVpaUCZuKHFJ1wGlLvpDgVa4hMWcvca9SDIenRhZVQ7e/cdcp+5iLxh zRz16Lhq9EDHU4m48MJD/zqquaMdPVRNTT32LJA9MHnow+jFte69W+ivVT5eUg5t/DCx K0YNhAtEUffXi4aWFG4PJ1DS9vDcstoKgueArCMSi0Yt9/iVDm/py3eBDmNcfRwFaCZz dOvPCP7PI0/R0uoLGzUCn+5VbYi3cDPSERZD35ltwV85f2TVCqq91VFeOqYTnQcoq86X BQ== Received: from aserv0022.oracle.com (aserv0022.oracle.com [141.146.126.234]) by userp2120.oracle.com with ESMTP id 2qhredygx6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 13 Feb 2019 02:57:23 +0000 Received: from userv0122.oracle.com (userv0122.oracle.com [156.151.31.75]) by aserv0022.oracle.com (8.14.4/8.14.4) with ESMTP id x1D2vMts020956 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 13 Feb 2019 02:57:22 GMT Received: from abhmp0018.oracle.com (abhmp0018.oracle.com [141.146.116.24]) by userv0122.oracle.com (8.14.4/8.14.4) with ESMTP id x1D2vLbJ021547; Wed, 13 Feb 2019 02:57:22 GMT Received: from ca-mkp.ca.oracle.com (/10.156.108.201) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Tue, 12 Feb 2019 18:57:21 -0800 From: "Martin K. Petersen" To: linux-scsi@vger.kernel.org, linux-block@vger.kernel.org Cc: "Martin K. Petersen" , Jeremy Cline , Oleksii Kurochko , stable@vger.kernel.org Subject: [PATCH v2] scsi: sd: block: Fix regressions in read-only block device handling Date: Tue, 12 Feb 2019 21:57:17 -0500 Message-Id: <20190213025717.20057-1-martin.petersen@oracle.com> X-Mailer: git-send-email 2.19.2 In-Reply-To: References: MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=9165 signatures=668683 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1902130017 Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Some devices come online in write protected state and switch to read-write once they are ready to process I/O requests. These devices broke with commit 20bd1d026aac ("scsi: sd: Keep disk read-only when re-reading partition") because we had no way to distinguish between a user decision to set a block_device read-only and the actual hardware device being write-protected. Because partitions are dropped and recreated on revalidate we are unable to persist any user-provided policy in hd_struct. Introduce a bitmap in struct gendisk to track the user configuration. This bitmap is updated when BLKROSET is called on a given disk or partition. A helper function, get_user_ro(), is provided to determine whether the ioctl has forced read-only state for a given block device. This helper is used by set_disk_ro() and add_partition() to ensure that both existing and newly created partitions will get the correct state. - If BLKROSET sets a whole disk device read-only, all partitions will now end up in a read-only state. - If BLKROSET sets a given partition read-only, that partition will remain read-only post revalidate. - Otherwise both the whole disk device and any partitions will reflect the write protect state of the underlying device. Cc: Jeremy Cline Cc: Oleksii Kurochko Cc: stable@vger.kernel.org # v4.16+ Reported-by: Oleksii Kurochko Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=201221 Fixes: 20bd1d026aac ("scsi: sd: Keep disk read-only when re-reading partition") Signed-off-by: Martin K. Petersen Reviewed-by: Hannes Reinecke --- v2: - Track user read-only state in a bitmap - Work around the regression that caused us to drop user preferences on revalidate --- block/genhd.c | 22 +++++++++++++++++----- block/ioctl.c | 4 ++++ block/partition-generic.c | 2 +- drivers/scsi/sd.c | 4 +--- include/linux/genhd.h | 2 ++ 5 files changed, 25 insertions(+), 9 deletions(-) diff --git a/block/genhd.c b/block/genhd.c index 1dd8fd6613b8..34667eb1d3cc 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1544,19 +1544,31 @@ void set_device_ro(struct block_device *bdev, int flag) EXPORT_SYMBOL(set_device_ro); +bool get_user_ro(struct gendisk *disk, unsigned int partno) +{ + /* Is the user read-only bit set for the whole disk device? */ + if (test_bit(0, disk->user_ro_bitmap)) + return true; + + /* Is the user read-only bit set for this particular partition? */ + if (test_bit(partno, disk->user_ro_bitmap)) + return true; + + return false; +} +EXPORT_SYMBOL(get_user_ro); + void set_disk_ro(struct gendisk *disk, int flag) { struct disk_part_iter piter; struct hd_struct *part; - if (disk->part0.policy != flag) { + if (disk->part0.policy != flag) set_disk_ro_uevent(disk, flag); - disk->part0.policy = flag; - } - disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); + disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY_PART0); while ((part = disk_part_iter_next(&piter))) - part->policy = flag; + part->policy = get_user_ro(disk, part->partno) ?: flag; disk_part_iter_exit(&piter); } diff --git a/block/ioctl.c b/block/ioctl.c index 4825c78a6baa..41206df89485 100644 --- a/block/ioctl.c +++ b/block/ioctl.c @@ -451,6 +451,10 @@ static int blkdev_roset(struct block_device *bdev, fmode_t mode, return ret; if (get_user(n, (int __user *)arg)) return -EFAULT; + if (n) + set_bit(bdev->bd_partno, bdev->bd_disk->user_ro_bitmap); + else + clear_bit(bdev->bd_partno, bdev->bd_disk->user_ro_bitmap); set_device_ro(bdev, n); return 0; } diff --git a/block/partition-generic.c b/block/partition-generic.c index 8e596a8dff32..c6a3c21c2496 100644 --- a/block/partition-generic.c +++ b/block/partition-generic.c @@ -338,7 +338,7 @@ struct hd_struct *add_partition(struct gendisk *disk, int partno, queue_limit_discard_alignment(&disk->queue->limits, start); p->nr_sects = len; p->partno = partno; - p->policy = get_disk_ro(disk); + p->policy = get_user_ro(disk, partno) ?: get_disk_ro(disk); if (info) { struct partition_meta_info *pinfo = alloc_part_info(disk); diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c index 67cc439b86e4..5dfe37b08d3b 100644 --- a/drivers/scsi/sd.c +++ b/drivers/scsi/sd.c @@ -2591,10 +2591,8 @@ sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer) int res; struct scsi_device *sdp = sdkp->device; struct scsi_mode_data data; - int disk_ro = get_disk_ro(sdkp->disk); int old_wp = sdkp->write_prot; - set_disk_ro(sdkp->disk, 0); if (sdp->skip_ms_page_3f) { sd_first_printk(KERN_NOTICE, sdkp, "Assuming Write Enabled\n"); return; @@ -2632,7 +2630,7 @@ sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer) "Test WP failed, assume Write Enabled\n"); } else { sdkp->write_prot = ((data.device_specific & 0x80) != 0); - set_disk_ro(sdkp->disk, sdkp->write_prot || disk_ro); + set_disk_ro(sdkp->disk, sdkp->write_prot); if (sdkp->first_scan || old_wp != sdkp->write_prot) { sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n", sdkp->write_prot ? "on" : "off"); diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 06c0fd594097..9645c2604465 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -194,6 +194,7 @@ struct gendisk { */ struct disk_part_tbl __rcu *part_tbl; struct hd_struct part0; + DECLARE_BITMAP(user_ro_bitmap, DISK_MAX_PARTS); const struct block_device_operations *fops; struct request_queue *queue; @@ -433,6 +434,7 @@ extern struct block_device *bdget_disk(struct gendisk *disk, int partno); extern void set_device_ro(struct block_device *bdev, int flag); extern void set_disk_ro(struct gendisk *disk, int flag); +extern bool get_user_ro(struct gendisk *disk, unsigned int partno); static inline int get_disk_ro(struct gendisk *disk) {