From d90db3b1c8676bc88b4309c5a571333de2263b8e Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 15 Nov 2022 22:10:45 +0800
Subject: [PATCH] block: clear ->slave_dir when dropping the main slave_dir
 reference
Git-commit: d90db3b1c8676bc88b4309c5a571333de2263b8e
Patch-mainline: v6.2-rc1
References: git-fixes

Zero out the pointer to ->slave_dir so that the holder code doesn't
incorrectly treat the object as alive when add_disk failed or after
del_gendisk was called.

(Coly Li: rebased for Linux v5.14 based SUSE kernel)

Fixes: 89f871af1b26 ("dm: delay registering the gendisk")
Reported-by: Yu Kuai <yukuai3@huawei.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Mike Snitzer <snitzer@kernel.org>
Link: https://lore.kernel.org/r/20221115141054.1051801-2-yukuai1@huaweicloud.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>

---
 block/genhd.c |    1 +
 1 file changed, 1 insertion(+)

--- a/block/genhd.c
+++ b/block/genhd.c
@@ -620,6 +620,7 @@ void del_gendisk(struct gendisk *disk)
 
 	kobject_put(disk->part0->bd_holder_dir);
 	kobject_put(disk->slave_dir);
+	disk->slave_dir = NULL;
 
 	part_stat_set_all(disk->part0, 0);
 	disk->part0->bd_stamp = 0;