bdi lifetime fix
From: Christoph Hellwig <hch@lst.de>
Date: 2021-08-16 12:27:55
Hi Jens, this series fixes a bdi lifetime issue. The bug report was triggered by the move of the bdi to the gendisk, but the underlying issue is much older. This supersedes the ealier "block: ensure the bdi is freed after inode_detach_wb" patch.