[patch] allow crash dumps to Linux swap partitions

[Don Lewis]

On 17 Feb, Doug Barton wrote:
> On 01/08/2012 12:35, Don Lewis wrote:
>> I've got a machine that is set up to dual boot both FreeBSD and Linux.
>> It is also disk space impaired, so to make the best use possible of the
>> available space, I have FreeBSD set up to swap to the Linux swap
>> partition. Until now I haven't had working crash dumps because geom
>> didn't permit crash dumps to Linux swap partitions. This patch removes
>> that limitation.  This could be useful for users of laptops who boot
>> multiple operating systems.
> 
> 
> So I gave this a try, and I'm getting this:
> 
> 
> GEOM_PART:dumpon:  ioctl(DIOCSKERNELDUMP)P: artition 'ad0s4' not
> suitable for kernel dumps (wrong type?)
> Operation not supported by device
> /etc/rc: WARNING: unable to specify /dev/ad0s7 as a dump device
> 
> I'm guessing that this is due to ad0s7 being in an extended partition.
> So I take it we have no support for dumping to logical partition?

I made the same change to g_part_ebr.c that I made to g_part_mbr.c but I
didn't have a way of testing it because I don't have any drives with
extended partitions.  Is the partition type 0x82?  Maybe there's another
problem in g_part_ebr_dumpto().  It's probably never been exercised
before.