From 6c6b3549142255c3fe4bab5560efdf8391c8d858 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 3 Dec 2019 10:39:08 +0100 Subject: block: set the zone size in blk_revalidate_disk_zones atomically MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 Reviewed-by: Javier González Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- drivers/block/null_blk_main.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'drivers/block') 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, -- cgit v1.2.3