Message-ID: <a4b285ba-4a46-c94b-444e-d3c4f42c42c5@acm.org>
Date:   Mon, 13 Dec 2021 21:04:29 -0800
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Subject: Re: [PATCH v3 3/3] blk-crypto: show crypto capabilities in sysfs
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To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     Eric Biggers <ebiggers@kernel.org>, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org, linux-api@vger.kernel.org,
        linux-scsi@vger.kernel.org, linux-mmc@vger.kernel.org,
        Hannes Reinecke <hare@suse.de>
References: <20211208013534.136590-1-ebiggers@kernel.org>
 <20211208013534.136590-4-ebiggers@kernel.org>
 <6ff4d074-7508-4f4c-de06-f36899668168@acm.org>
 <YbKT/lcp6iZ+lD4n@sol.localdomain> <YbL2uUqV0GWFOitE@kroah.com>
 <cb29756b-8b21-5b4d-f107-b5573945d7ab@acm.org> <YbSCYyAv1SmYy7mz@kroah.com>
From:   Bart Van Assche <bvanassche@acm.org>
In-Reply-To: <YbSCYyAv1SmYy7mz@kroah.com>
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On 12/11/21 02:50, Greg Kroah-Hartman wrote:
> On Fri, Dec 10, 2021 at 09:29:41AM -0800, Bart Van Assche wrote:
>> (b) No other block layer sysfs attribute follows this encoding scheme.
> 
> Then follow what they do.  Do they have multiple values in a single
> file?  If so, they are broken and we should change that.

Hi Greg,

The only other block layer sysfs attribute I know of that reports 
multiple values is the queue/scheduler attribute. Here is an example of 
the output that can be produced by reading that attribute:

# cat /sys/block/sda/queue/scheduler
[mq-deadline] kyber bfq none

I don't think that changing the behavior of that attribute is an option 
because that would break existing user space software, e.g. the 
https://github.com/osandov/blktests/ test suite.

Thanks,

Bart.