From mboxrd@z Thu Jan  1 00:00:00 1970
From: sagi@grimberg.me (Sagi Grimberg)
Date: Fri, 15 Mar 2019 10:17:18 -0700
Subject: [PATCH v4 1/3] nvme: set 0 capacity if namespace block size
 exceeds PAGE_SIZE
In-Reply-To: <20190315162837.GA27308@lst.de>
References: <20190311220227.23656-1-sagi@grimberg.me>
 <20190311220227.23656-2-sagi@grimberg.me> <20190312143231.GA1149@lst.de>
 <8a80ce70-0b98-6c82-a47c-f312a41d2d2a@grimberg.me>
 <20190315162837.GA27308@lst.de>
Message-ID: <cd8a5428-602f-c9c9-3cf9-235d13a9451a@grimberg.me>


>>> I like the idea behind this, but it looks rather convoluted.  I think
>>> for the unusable namespace case we should warn and have a common label
>>> that just sets the capacity, not touching anything else.
>>>
>>> Does something like this work for you?
>>
>> No, this is what I had done originally, but we need to always have the
>> queue set to a decent block size, otherwise blk_queue_stack_limits()
>> panics on div by 0..
> 
> I actually tested it by manually hacking a 8k block size into nvmet
> and and it works just fine for me.  Where do you see a division by
> zero with this patch exactly?

You need your block size to exceed u16 bs.

Then run blktest/tests/nvme/009 with multipath on.