From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mike Christie <mchristi@redhat.com>
Subject: Re: RFC: remove REQ_OP_WRITE_SAME
Date: Tue, 11 Apr 2017 11:49:46 -0500
Message-ID: <58ED092A.5080901@redhat.com>
References: <20170410160807.23674-1-hch@lst.de>
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To: Christoph Hellwig <hch@lst.de>, axboe@kernel.dk, martin.petersen@oracle.com, philipp.reisner@linbit.com, lars.ellenberg@linbit.com, target-devel@vger.kernel.org
Cc: linux-block@vger.kernel.org, linux-scsi@vger.kernel.org, drbd-dev@lists.linbit.com, dm-devel@redhat.com
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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.