[patch] allow crash dumps to Linux swap partitions

[Garrett Cooper]

On Sun, Jan 8, 2012 at 3:33 PM, Xin LI <delphij at gmail.com> wrote:
> On Sun, Jan 8, 2012 at 3:03 PM, Garrett Cooper <yanegomi at gmail.com> wrote:
>> On Sun, Jan 8, 2012 at 12:35 PM, Don Lewis <truckman at freebsd.org> 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.
>>
>>    Seems like a good idea, but could dumping to a Linux partition
>> confuse FreeBSD or vice versa?
>
> Unlikely, these are scratch spaces and validated upon boot (i.e. the
> dump saver would "taste" before saving).

So the answer is:
1. No for FreeBSD
2. It's unlikely that the Linux side will be affected
?
    I would just be concerned with some potentially more interesting
cases where the swap for a crashdump got partially overwritten, but
the same issue would exist I suppose with FreeBSD if someone whacked
the contents of a partition I suppose, e.g. it's not a big issue if
the tools that grok the crashdump fail gracefully.
Thanks!
-Garrett