On 04/10/2017 11:07 AM, Christoph Hellwig wrote: > Now that we are using REQ_OP_WRITE_ZEROES for all zeroing needs in the > kernel there is very little use left for REQ_OP_WRITE_SAME. We only > have two callers left, and both just export optional protocol features > to remote systems: DRBD and the target code. > > Do we have any major users of those? If not removing it will clean up > a few warts in the block layer. I added the iblock write same support because for RBD/ceph we were going to pass it from rbd down to the OSD. We are using tcmu right now, so we no longer need iblock support.