On Thu, Mar 30, 2017 at 12:06:41PM +0200, Lars Ellenberg wrote: > On Thu, Mar 23, 2017 at 10:33:40AM -0400, Christoph Hellwig wrote: > > It seems like DRBD assumes its on the wire TRIM request always zeroes data. > > Use that fact to implement REQ_OP_WRITE_ZEROES. > > > > XXX: will need a careful audit from the drbd team! > > Thanks, this one looks ok to me. So the DRBD protocol requires the TRIM operation to always zero? > The real question for me is, will the previous one (21/23) > return != 0 (some EOPNOTSUPP or else) to DRBD in more situations than > what we have now? No, blkdev_issue_zeroout should never return -EOPNOTSUPP. > Will it make an fstrim cause thinly provisioned > devices to suddenly be fully allocated? Not for SCSI devices. Yes for dm-thinp until it implements REQ_OP_WRITE_ZEROES, which will hopefully be soon.
