On Wed, Oct 20, 2021 at 12:39:22AM +0800, Ming Lei wrote: > On Tue, Oct 19, 2021 at 08:50:24AM -0700, Luis Chamberlain wrote: > > So do you want to take the position: > > > > Hey driver authors: you cannot use any shared lock on module removal and > > on sysfs ops? > > IMO, yes, in your patch of 'zram: fix crashes with cpu hotplug multistate', > when you added mutex_lock(zram_index_mutex) to disksize_store() and > other attribute show() or store() method. You have added new deadlock > between hot_remove_store() and disksize_store() & others, which can't be > addressed by your approach of holding module refcnt. > > So far not see ltp tests covers hot add/remove interface yet. Care to show what commands to use to cause this deadlock with my patches? Luis