Re: [PATCH 22/23] drbd: implement REQ_OP_WRITE_ZEROES

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



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.

--
dm-devel mailing list
dm-devel@xxxxxxxxxx
https://www.redhat.com/mailman/listinfo/dm-devel



[Index of Archives]     [DM Crypt]     [Fedora Desktop]     [ATA RAID]     [Fedora Marketing]     [Fedora Packaging]     [Fedora SELinux]     [Yosemite Discussion]     [KDE Users]     [Fedora Docs]

  Powered by Linux