On Fri, Mar 15, 2024 at 02:23:07PM +0100, Christian Brauner wrote: > Now that we open block devices as files we need to deal with the > realities that closing is a deferred operation. An operation on the > block device such as e.g., freeze, thaw, or removal that runs > concurrently with umount, tries to acquire a stable reference on the > holder. The holder might already be gone though. Make that reliable by > grabbing a passive reference to the holder during bdev_open() and > releasing it during bdev_release(). Looks good: Reviewed-by: Christoph Hellwig <hch@xxxxxx> does bcachefs also need a fix for it's holder ops? Or does it get to keep the pieces as it has it's own NULL holder_ops and obviously doens't care about getting any of this right?