From: Hannes Reinecke <hare@suse.de>
To: Keith Busch <keith.busch@intel.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>,
Christoph Hellwig <hch@lst.de>,
linux-scsi@vger.kernel.org,
Bart van Assche <bart.vanassche@sandisk.com>,
Hannes Reinecke <hare@suse.com>
Subject: Re: [PATCHv2] scsi: use 'scsi_device_from_queue()' for scsi_dh
Date: Fri, 17 Feb 2017 09:06:14 +0100 [thread overview]
Message-ID: <c889eed7-6262-2e54-0b1e-1d833c033324@suse.de> (raw)
In-Reply-To: <20170216170519.GA9630@localhost.localdomain>
On 02/16/2017 06:05 PM, Keith Busch wrote:
> On Thu, Feb 16, 2017 at 04:12:23PM +0100, Hannes Reinecke wrote:
>> The device handler needs to check if a given queue belongs to
>> a scsi device; only then does it make sense to attach a device
>> handler.
>>
>> Signed-off-by: Hannes Reinecke <hare@suse.com>
>
> The thing I don't like is that this still has dm-mpath directly calling
> into scsi. I don't think dm-mpath has any business calling protocol
> specific APIs, and doesn't help other protocols with similar needs.
>
> Can we solve this with an indirection layer instead?
>
> (untested; just checking if this direction is preferable)
We could, but why?
ATM we're only having SCSI devices able to use device handler; adding
another layer of indirection doesn't solve anything here.
Moving the infrastructure one level up will only make sense if we're
getting non-SCSI device handler (ANA?), but until then I'd think it's
just overengineering.
Cheers,
Hannes
--
Dr. Hannes Reinecke Teamlead Storage & Networking
hare@suse.de +49 911 74053 688
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: F. Imendörffer, J. Smithard, J. Guild, D. Upmanyu, G. Norton
HRB 21284 (AG Nürnberg)
next prev parent reply other threads:[~2017-02-17 8:06 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-16 15:12 [PATCHv2] scsi: use 'scsi_device_from_queue()' for scsi_dh Hannes Reinecke
2017-02-16 16:09 ` Bart Van Assche
2017-02-17 7:19 ` Hannes Reinecke
2017-02-16 17:05 ` Keith Busch
2017-02-16 17:13 ` Keith Busch
2017-02-17 8:06 ` Hannes Reinecke [this message]
2017-02-17 8:27 ` Christoph Hellwig
2017-02-19 5:59 ` Mike Snitzer
2017-02-19 5:59 ` Mike Snitzer
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