From patchwork Tue Dec 3 09:39:08 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11270877 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9E06E13B6 for ; Tue, 3 Dec 2019 09:39:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 73128206F0 for ; Tue, 3 Dec 2019 09:39:30 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="AYpVquDd" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726182AbfLCJj3 (ORCPT ); Tue, 3 Dec 2019 04:39:29 -0500 Received: from bombadil.infradead.org ([198.137.202.133]:33160 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726115AbfLCJj3 (ORCPT ); Tue, 3 Dec 2019 04:39:29 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.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:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=Tld7yeuyFzA1rKT+6njc/e7upZje2HvkNA0/lhtjung=; b=AYpVquDdaR80Q8mXlCflpdMaS/ +XKV25/4CARhT1oI2q5PMmtah1sNmGrL7xjku5mQmVC0vgj5Cm08+5myhLsqdSFYFXzZn1ucoSO1N prgLJ3AmYWt0faO+TR0Q+6MsbAo2MZTJDV/KilKn+P70uvW/xabjHKkCweDSzx9rf2448BvZBbY0W gTL5wjqrE2PoYud20ffOulT0f3w+S33RQpYmTA3Di6ltcA3V4j7jJdpDyS7iUqRAE1/QedbOrf/Mm LllovtJngGgxUMfdUIgOWcLdjcGQDKWhPitywgDkJnGwcgerS/BpvRtD+M58x9iEHp55fbhV97NXP Y0gl/X6g==; Received: from clnet-p19-102.ikbnet.co.at ([83.175.77.102] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1ic4eW-0002AR-OH; Tue, 03 Dec 2019 09:39:29 +0000 From: Christoph Hellwig To: Jens Axboe Cc: Damien Le Moal , Hans Holmberg , linux-block@vger.kernel.org Subject: [PATCH 8/8] block: set the zone size in blk_revalidate_disk_zones atomically Date: Tue, 3 Dec 2019 10:39:08 +0100 Message-Id: <20191203093908.24612-9-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191203093908.24612-1-hch@lst.de> References: <20191203093908.24612-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org The current zone revalidation code has a major problem in that it doesn't update the zone size and q->nr_zones atomically, leading to a short window where an out of bounds access to the zone arrays is possible. To fix this move the setting of the zone size into the crticial sections blk_revalidate_disk_zones so that it gets updated together with the zone bitmaps and q->nr_zones. This also slightly simplifies the caller as it deducts the zone size from the report_zones. This change also allows to check for a power of two zone size in generic code. Reported-by: Hans Holmberg Signed-off-by: Christoph Hellwig --- block/blk-zoned.c | 59 ++++++++++++++++++++--------------- drivers/block/null_blk_main.c | 3 +- drivers/scsi/sd_zbc.c | 2 -- 3 files changed, 35 insertions(+), 29 deletions(-) diff --git a/block/blk-zoned.c b/block/blk-zoned.c index 51d427659ce7..d00fcfd71dfe 100644 --- a/block/blk-zoned.c +++ b/block/blk-zoned.c @@ -343,6 +343,7 @@ struct blk_revalidate_zone_args { unsigned long *conv_zones_bitmap; unsigned long *seq_zones_wlock; unsigned int nr_zones; + sector_t zone_sectors; sector_t sector; }; @@ -355,25 +356,33 @@ static int blk_revalidate_zone_cb(struct blk_zone *zone, unsigned int idx, struct blk_revalidate_zone_args *args = data; struct gendisk *disk = args->disk; struct request_queue *q = disk->queue; - sector_t zone_sectors = blk_queue_zone_sectors(q); sector_t capacity = get_capacity(disk); /* * All zones must have the same size, with the exception on an eventual * smaller last zone. */ - if (zone->start + zone_sectors < capacity && - zone->len != zone_sectors) { - pr_warn("%s: Invalid zoned device with non constant zone size\n", - disk->disk_name); - return false; - } + if (zone->start == 0) { + if (zone->len == 0 || !is_power_of_2(zone->len)) { + pr_warn("%s: Invalid zoned device with non power of two zone size (%llu)\n", + disk->disk_name, zone->len); + return -ENODEV; + } - if (zone->start + zone->len >= capacity && - zone->len > zone_sectors) { - pr_warn("%s: Invalid zoned device with larger last zone size\n", - disk->disk_name); - return -ENODEV; + args->zone_sectors = zone->len; + args->nr_zones = (capacity + zone->len - 1) >> ilog2(zone->len); + } else if (zone->start + args->zone_sectors < capacity) { + if (zone->len != args->zone_sectors) { + pr_warn("%s: Invalid zoned device with non constant zone size\n", + disk->disk_name); + return -ENODEV; + } + } else { + if (zone->len > args->zone_sectors) { + pr_warn("%s: Invalid zoned device with larger last zone size\n", + disk->disk_name); + return -ENODEV; + } } /* Check for holes in the zone report */ @@ -428,9 +437,9 @@ int blk_revalidate_disk_zones(struct gendisk *disk) struct request_queue *q = disk->queue; struct blk_revalidate_zone_args args = { .disk = disk, - .nr_zones = blkdev_nr_zones(disk), }; - int ret = 0; + unsigned int noio_flag; + int ret; if (WARN_ON_ONCE(!blk_queue_is_zoned(q))) return -EIO; @@ -438,24 +447,22 @@ int blk_revalidate_disk_zones(struct gendisk *disk) return -EIO; /* - * Ensure that all memory allocations in this context are done as - * if GFP_NOIO was specified. + * Ensure that all memory allocations in this context are done as if + * GFP_NOIO was specified. */ - if (args.nr_zones) { - unsigned int noio_flag = memalloc_noio_save(); - - ret = disk->fops->report_zones(disk, 0, args.nr_zones, - blk_revalidate_zone_cb, &args); - memalloc_noio_restore(noio_flag); - } + noio_flag = memalloc_noio_save(); + ret = disk->fops->report_zones(disk, 0, UINT_MAX, + blk_revalidate_zone_cb, &args); + memalloc_noio_restore(noio_flag); /* - * Install the new bitmaps, making sure the queue is stopped and - * all I/Os are completed (i.e. a scheduler is not referencing the - * bitmaps). + * Install the new bitmaps and update nr_zones only once the queue is + * stopped and all I/Os are completed (i.e. a scheduler is not + * referencing the bitmaps). */ blk_mq_freeze_queue(q); if (ret >= 0) { + blk_queue_chunk_sectors(q, args.zone_sectors); q->nr_zones = args.nr_zones; swap(q->seq_zones_wlock, args.seq_zones_wlock); swap(q->conv_zones_bitmap, args.conv_zones_bitmap); diff --git a/drivers/block/null_blk_main.c b/drivers/block/null_blk_main.c index 068cd0ae6e2c..997b7dc095b9 100644 --- a/drivers/block/null_blk_main.c +++ b/drivers/block/null_blk_main.c @@ -1583,6 +1583,8 @@ static int null_gendisk_register(struct nullb *nullb) if (ret) return ret; } else { + blk_queue_chunk_sectors(nullb->q, + nullb->dev->zone_size_sects); nullb->q->nr_zones = blkdev_nr_zones(disk); } } @@ -1746,7 +1748,6 @@ static int null_add_dev(struct nullb_device *dev) if (rv) goto out_cleanup_blk_queue; - blk_queue_chunk_sectors(nullb->q, dev->zone_size_sects); nullb->q->limits.zoned = BLK_ZONED_HM; blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, nullb->q); blk_queue_required_elevator_features(nullb->q, diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c index 0e5ede48f045..27d72c1d4654 100644 --- a/drivers/scsi/sd_zbc.c +++ b/drivers/scsi/sd_zbc.c @@ -412,8 +412,6 @@ int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buf) goto err; /* The drive satisfies the kernel restrictions: set it up */ - blk_queue_chunk_sectors(sdkp->disk->queue, - logical_to_sectors(sdkp->device, zone_blocks)); blk_queue_flag_set(QUEUE_FLAG_ZONE_RESETALL, sdkp->disk->queue); blk_queue_required_elevator_features(sdkp->disk->queue, ELEVATOR_F_ZBD_SEQ_WRITE);