On 01/18/2012 05:04 PM, Ben Hutchings wrote:

quoted

 There is harm.  You'll be blacklisting also the standard block device
 ioctls, and those won't work on 32-on-64 anymore.  A system with 32-bit
 userland will likely not boot anymore.

It does (yes, I tested that myself now).  The standard block device
ioctls are handled without calling the driver's compat_ioctl.

What about the non-compat path when done by non-root?

* Does BLKROSET still return EACCES when run by non-root and without 
CAP_SYS_ADMIN?  I suspect your patch is changing it to EINVAL.

* Does BLKFLSBUF work when run by non-root but with CAP_SYS_ADMIN?

Paolo