From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Disseldorp <ddiss@suse.de>
Subject: Re: [PATCH 2/2] rbd: get rid of rbd_mapping::read_only
Date: Wed, 8 Nov 2017 19:32:42 +0100
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To: Ilya Dryomov <idryomov@gmail.com>
Cc: Ceph Development <ceph-devel@vger.kernel.org>

On Tue, 7 Nov 2017 17:56:51 +0100, Ilya Dryomov wrote:

> Heh, apparently I only tested writes and didn't do discards...  Writes
> go through blkdev_write_iter() but zeroout/discards seem to rely solely
> on FMODE_WRITE checks, which the block layer doesn't enforce.
> 
> I'd rather try to fix it in the block layer before working around it in
> krbd.  I'll work up a patch tomorrow.

FWIW I've pushed a blktests regression test for this to the
wip_ro_get_set_discard branch of my repo at:
https://github.com/ddiss/blktests.git

Cheers, David