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From a0a6314ae774f8a5e52a599946aa2ad0db867b83 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Mon, 10 Oct 2022 15:18:57 +0200
Subject: [PATCH] block: fix leaking minors of hidden disks
Git-commit: a0a6314ae774f8a5e52a599946aa2ad0db867b83
Patch-mainline: v6.1-rc1
References: git-fixes

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 <dwagner@suse.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Daniel Wagner <dwagner@suse.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Link: https://lore.kernel.org/r/20221010131857.748129-1-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>

---
 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);
-- 
2.35.3