On Thu, Aug 27, 2020 at 09:25:07AM +0200, Hannes Reinecke wrote: > Do you really need the mutex? > Wouldn't xa_store_range() be better and avoid the mutex? We need the mutex as we need to grab the kobject reference under it. xa_store_range is only available with a separate config option, and has really strange calling conventions. So I'd rather not pull it in here, especially as most cdev_add callers are for a single minor only anyway.