Re: regarding major number of block extended devt

[Jens Axboe <jens.axboe@oracle.com>]

On Thu, Sep 04 2008, Tejun Heo wrote:
> Hello,
> 
> H. Peter Anvin wrote:
> > Thinking about it some more, one invariant this is *guaranteed* to
> > violate is:
> > 
> >     partition_number = partition_device - master_device
> > 
> > Code that needs a partition number (which is common enough) are using
> > this invariant, because (a) it has held for 17 years and (b) because
> > there is still no alternative other that relying on fragile naming
> > scheme hacks.
> > 
> > (a) we can't do anything about, but (b) we can, by introducing a
> > partition number attribute in sysfs.
> 
> Yeah, that would certainly be a nice addition.  Also, if partitions
> are made proper classes, they'll be easily enumerable by
> /sys/block/*/partitions/*.
> 
> Jens, what do you think?

Agree, that addition definitely makes sense.

-- 
Jens Axboe