From: Cong Wang <xiyou.wangc...@gmail.com> Date: Wed, 5 Jul 2017 13:50:00 -0700
> We are not allowed to block on the RCU reader side, so can't > just hold the mutex as before. As a quick fix, convert it to > a spinlock. > > Fixes: d9f1f61c0801 ("tap: Extending tap device create/destroy APIs") > Reported-by: Christian Borntraeger <borntrae...@de.ibm.com> > Cc: Sainath Grandhi <sainath.gran...@intel.com> > Signed-off-by: Cong Wang <xiyou.wangc...@gmail.com> I agree with Eric that we should use idr_preload() and idr_preload_end() here so that we can still use GFP_KERNEL even though we're now using a spinlock instead of a mutex.