From a0a6314ae774f8a5e52a599946aa2ad0db867b83 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 10 Oct 2022 15:18:57 +0200 Subject: [PATCH] block: fix leaking minors of hidden disks The major/minor of a hidden gendisk is not propagated to the block device because it is never registered using bdev_add. But the lack of bd_dev also causes the dynamic major minor number not to be freed. Assign bd_dev manually to ensure the dynamic major minor gets freed. Based on a patch by Keith Busch. Fixes: 8ddcd653257c ("block: introduce GENHD_FL_HIDDEN") Reported-by: Daniel Wagner Signed-off-by: Christoph Hellwig Tested-by: Daniel Wagner Reviewed-by: Keith Busch Link: https://lore.kernel.org/r/20221010131857.748129-1-hch@lst.de Signed-off-by: Jens Axboe --- block/genhd.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/block/genhd.c b/block/genhd.c index d6a21803a57e..dc9b61dfb692 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -507,6 +507,13 @@ int __must_check device_add_disk(struct device *parent, struct gendisk *disk, */ dev_set_uevent_suppress(ddev, 0); disk_uevent(disk, KOBJ_ADD); + } else { + /* + * Even if the block_device for a hidden gendisk is not + * registered, it needs to have a valid bd_dev so that the + * freeing of the dynamic major works. + */ + disk->part0->bd_dev = MKDEV(disk->major, disk->first_minor); } disk_update_readahead(disk);