[libvirt] [PATCH]: Rework xenLinuxDomainDeviceID to support more devices

[Daniel P. Berrange]

On Tue, Aug 05, 2008 at 06:47:34AM -0400, Daniel Veillard wrote:
> On Tue, Aug 05, 2008 at 12:12:21PM +0200, Chris Lalancette wrote:
> > Recently upstream Xen added support for having xvd devices > 16.  For the most
> > part, this doesn't really concern libvirt, since for things like attach and
> > detach we just pass it through and let xend worry about whether it is supported
> > or not.  The one place this breaks down is in the stats collecting code, where
> > we need to figure out the device number so we can go digging in /sys for the
> > statistics.
> > 
> > To remedy this, I've re-written xenLinuxDomainDeviceID() to use regular
> > expressions to figure out the device number from the name.  The major advantage
> > is that now xenLinuxDomainDeviceID() looks fairly identical to
> > tools/python/xen/util/blkif.py (in the Xen sources), so that adding additional
> > devices in the future should be much easier.  It also reduces the size of the
> > code, and, in my opinion, the code complexity.
> > 
> > With this patch in place, I was able to get block statistics both on older style
> > devices (/dev/xvda) and on the new, expanded devices (/dev/xvdaa).
> 
>   Sounds good to me even if I don't grasp all the naming convention.
> 
> > Signed-off-by: Chris Lalancette <clalance at redhat.com>
> [...]
> > +        /* OK, we have a match; see if we have a partition */
> > +        *part = 0;
> > +        if (pmatch[1].rm_so != -1)
> > +            *part = strtol(path + pmatch[1].rm_so, NULL, 10);
> 
>  let's use __virStrToLong_i internally
> 
> I think it makes that code a bit more readable too, +1

It is more readable because it doesn't give as detailed error
reporting to the caller. I don't consider that a positive thing

Daniel
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