Re: [PATCH 1/2] block: prevent block device lookups at the beginning of del_gendisk

On Fri, May 14, 2021 at 03:18:41PM +0200, Christoph Hellwig wrote:

As an artifact of how gendisk lookup used to work in earlier kernels,
GENHD_FL_UP is only cleared very late in del_gendisk, and a global lock
is used to prevent opens from succeeding while del_gendisk is tearing
down the gendisk.  Switch to clearing the flag early and under bd_mutex
so that callers can use bd_mutex to stabilize the flag, which removes
the need for the global mutex.

Signed-off-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Ming Lei <redacted>

-- 
Ming