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: 8ddcd65 ("block: introduce GENHD_FL_HIDDEN") Reported-by: Daniel Wagner <[email protected]> Signed-off-by: Christoph Hellwig <[email protected]> Tested-by: Daniel Wagner <[email protected]> Reviewed-by: Keith Busch <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Jens Axboe <[email protected]>
josf · Oct 10, 2022 · a0a6314 · a0a6314
1 parent ca5eebd
commit a0a6314
Showing 1 changed file with 7 additions and 0 deletions.
diff --git 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);