Re: f_ops flag to speed up compatible ioctls in linux kernel

Albert Cahalan
2004-09-01T15:47:10Z

Michael S. Tsirkin writes:
> Quoting Lee Revell [snip -- that was excessive]

>> By adding a new ioctl you are adding a new use of
>> the BKL. It has been suggested on dri-devel that
>> this should be fixed. Is this even possible?
>
> I dont know - can the lock be released before the
> call to filp->f_op->ioctl ?
>
> I assume the reason its there is for legacy
> code - existing ioctls may be assuming the BKL
> is taken, but maybe there could be another flag
> in f_ops to let sys_ioctl release the lock before
> doing the call ...
>
> Like this - would that be safe?

Yes. It is proven to work.