Hello, On Mon, Mar 06, 2017 at 05:33:55PM +0100, Jan Kara wrote: > + disk->flags &= ~GENHD_FL_UP; > + /* > + * Make sure __blkdev_open() sees the disk is going away before > + * starting to unhash bdev inodes. > + */ > + smp_wmb(); But which rmb is this paired with? Without paring memory barriers don't do anything. Given that this isn't a super hot path, I think it'd be far better to stick to a simpler synchronization mechanism. Thanks. -- tejun