[Drbd-dev] always use REQ_OP_WRITE_ZEROES for zeroing offload

[Christoph Hellwig]

On Wed, Apr 05, 2017 at 07:40:36AM -0400, Martin K. Petersen wrote:
> > This series makes REQ_OP_WRITE_ZEROES the only zeroing offload
> > supported by the block layer, and switches existing implementations
> > of REQ_OP_DISCARD that correctly set discard_zeroes_data to it,
> > removes incorrect discard_zeroes_data, and also switches WRITE SAME
> > based zeroing in SCSI to this new method.
> 
> Very, very nice. I think this is the correct approach.
> 
> I'm going to send two follow-up patches that allow us to use UNMAP for
> discards and WRITE SAME w/ UNMAP for zeroout. That appears to be the
> preferred configuration for most storage devices.

Thanks, I'll resend it with your nitpicks fixed, your follow on
patches tacked on and the various reviewed-by tags in a bit.