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Subject: Re: [PATCH 1/1] nvme-fcloop: verify wwnn and wwpn format
To:     Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
        Dongli Zhang <dongli.zhang@oracle.com>,
        "linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
        "james.smart@broadcom.com" <james.smart@broadcom.com>
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        "hch@lst.de" <hch@lst.de>, "sagi@grimberg.me" <sagi@grimberg.me>
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From:   Hannes Reinecke <hare@suse.de>
Message-ID: <6c646a1e-ab40-63a1-01cb-6cc2548a3853@suse.de>
Date:   Thu, 4 Jun 2020 16:03:38 +0200
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On 6/4/20 8:54 AM, Chaitanya Kulkarni wrote:
> On 6/3/20 11:46 PM, Dongli Zhang wrote:
>> May I get feedback for this?
>>
>> For the first time I use fcloop, I set:
>>
>> # echo "wwnn=0x3,wwpn=0x1" > /sys/class/fcloop/ctl/add_target_port
>>
>> However, I would not be able to move forward if I use "0x3" or "0x1" for nvme-fc
>> target or host further. Instead, the address and port should be
>> 0x0000000000000003 and 0x0000000000000001.
>>
>> This patch would sync the requirements of input format for nvme-fc and
>> nvme-fcloop, unless this would break existing test suite (e.g., blktest).
> If I remember correctly I don't think we have fc-loop testcases (correct
> me if I'm wrong).
> 
Well, I sent some testcases a while back (cf 'fcloop and ANA fixes').
Should I resend them?

> Not an fc expert, but having uniform format for the input make sense to
> me (unless there is an explicit reason). I'll let James have a final say.
> 

I would stick to use the full 64bit number for both wwpn and wwnn; one 
gets into too many arguments otherwise (big-endian? little-endian?).
And one could argue that '0x0000000000000001' is invalid anyway as per 
FC-FS3 a '0' in word 0 byte 0 means 'Name not present' :-)

Cheers,

Hannes
-- 
Dr. Hannes Reinecke            Teamlead Storage & Networking
hare@suse.de                               +49 911 74053 688
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