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Re: allocate an official device major number for virtio device?

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On Wed, Mar 02, 2016 at 05:08:00PM -0800, Jin Qian wrote:
> Hi -
> 
> Can we allocate an official device major number for virtio devices?
> Currently it's using 240-254 (LOCAL/EXPERIMENTAL USE). The reason we
> ask for this is because userspace will need to treat virtio block
> devices differently and need a way to detect such device. For example,
> it checks major number to detect scsi and mmc device.
> 
> https://android-review.googlesource.com/#/c/195240
> 
> With dynamic major numbers 240-254, we might treat other devices as
> virtio block device incorrectly.

You shouldn't treat them incorrectly, devtmpfs handles this for you
automatically, so I'd recommend using the dynamic majors please.

And what in-kernel code is using the "experimental" range today?  Do you
have a pointer to that?  We should fix that now...

thanks,

greg k-h

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Thread

allocate an official device major number for virtio device? Jin Qian <jinqian@android.com> - 2016-03-03 02:10 +0100
  Re: allocate an official device major number for virtio device? Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-03 02:30 +0100
    Re: allocate an official device major number for virtio device? Jin Qian <jinqian@android.com> - 2016-03-03 02:50 +0100
      RE: allocate an official device major number for virtio device? "Ning, Yu" <yu.ning@intel.com> - 2016-03-03 05:00 +0100
        Re: allocate an official device major number for virtio device? One Thousand Gnomes <gnomes@lxorguk.ukuu.org.uk> - 2016-03-03 15:50 +0100
        Re: allocate an official device major number for virtio device? Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-03 18:20 +0100
          Re: allocate an official device major number for virtio device? Jin Qian <jinqian@android.com> - 2016-03-03 20:40 +0100
            Re: allocate an official device major number for virtio device? Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-03 21:10 +0100
              Re: allocate an official device major number for virtio device? Jeff Sharkey <jsharkey@android.com> - 2016-03-03 23:20 +0100
                Re: allocate an official device major number for virtio device? Richard Weinberger <richard.weinberger@gmail.com> - 2016-03-03 23:40 +0100
                Re: allocate an official device major number for virtio device? Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-03 23:50 +0100
      Re: allocate an official device major number for virtio device? Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-03-03 18:20 +0100

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