[PATCHv2] block: fix leaking minors of hidden disks

[Keith Busch <kbusch@meta.com>]

From: Keith Busch <kbusch@kernel.org>

The major/minor of a hidden gendisk is not propagated to the block
device. This is required to suppress it from being visible. For these
disks, we need to handle freeing the dynamic minor directly when it's
released since bdev_free_inode() won't be able to.

Cc: Christoph Hellwig <hch@lst.de>
Reported-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
---
v1->v2:

  Actually check that the disk is hidden before assuming the minor needs
  to be freed.

 block/genhd.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/block/genhd.c b/block/genhd.c
index 514395361d7c..0afcdbb7575c 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -1166,6 +1166,8 @@ static void disk_release(struct device *dev)
 	if (test_bit(GD_ADDED, &disk->state) && disk->fops->free_disk)
 		disk->fops->free_disk(disk);
 
+	if ((disk->flags & GENHD_FL_HIDDEN) && disk->major == BLOCK_EXT_MAJOR)
+		blk_free_ext_minor(disk->first_minor);
 	iput(disk->part0->bd_inode);	/* frees the disk */
 }
 
-- 
2.30.2