On Mon, Mar 19, 2018 at 08:52:24PM +0100, Christoph Hellwig wrote: > On Mon, Mar 19, 2018 at 07:36:50PM +0100, Jonas Rabenstein wrote: > > Allow modification of the shadow mbr. If the shadow mbr is not marked as > > done, this data will be presented read only as the device content. Only > > after marking the shadow mbr as done and unlocking a locking range the > > actual content is accessible. > > I hate doing this as an ioctls. Can we make this a sysfs binary file > so that people can use dd or cat to write the shadow mbr? I already thought about providing a sysfs interface for all that instead of using ioctls. But as I am pretty new to kernel programming I do not have all the required insight. Especially, as writing the mbr requires the sed-opal password I am unsure how a clean sysfs interface to provide the password together with a simple dd would look like. Moreover I already have a patch that changes the 'void *data' argument to setup_opal_dev to a kobject pointer. As far as I know, this is the first step to get into the sysfs hierarchy. But as I do not have access to an NVMe drive and have no idea about its implementation, this change works only for the scsi side. In other words, if someone could hint me in the right direction, I would be glad to (re)implement the ioctl interface for sysfs. Moreover, this would allow to export some additional information like the current state of the device (is it looke, is sed-opal enabled, whats the current state of mbr, etc.). - Jonas
