From mboxrd@z Thu Jan  1 00:00:00 1970
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: Re: RFC: removing hardcoded "modprobe blktap" in
 xencommons
Date: Fri, 12 Jul 2013 14:00:20 -0400
Message-ID: <20130712180020.GB9829@phenom.dumpdata.com>
References: <20130712161255.GB4409@zion.uk.xensource.com>
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To: Wei Liu <wei.liu2@citrix.com>
Cc: George Dunlap <george.dunlap@eu.citrix.com>, Ian Jackson <Ian.Jackson@eu.citrix.com>, Jan Beulich <JBeulich@suse.com>, xen-devel@lists.xen.org
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On Fri, Jul 12, 2013 at 05:12:55PM +0100, Wei Liu wrote:
> Hi Jan
> 
> Back before 4.3 release you complaint about the hardcoded modprobe for
> blktap / blktap2 in xencommons script. I started to look into it this
> week and tried to do this modprobe automatically in libxl (that's the
> idea we discussed before 4.3 IIRC).
> 
> Unfortunately I didn't manage to find any canonical documents on how a
> user space process can trigger a modprobe. I've looked at kernel
> documentations and couldn't find any. Do you have any reference on how
> to do that?

Ian and George talked to me on IRC about this. What we found (thanks for
Greg KH's help) was that you can use 'MODULE_ALIAS("devname:XYZ")'.

If any user application did an fopen("/dev/XYZ") then said module would be
automatically loaded.

> 
> And, why do you think it is bad to have "modprobe blktap" in xencommons?
> What about not removing it?
> 
> 
> Wei.
> 
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