Re: [PATCH] Remove HFS support

[Daniel Axtens]

John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> writes:

>> On Aug 19, 2022, at 3:59 PM, Daniel Kiper <dkiper@net-space.pl> wrote:
>> 
>> On Fri, Aug 19, 2022 at 11:38:26PM +1000, Daniel Axtens wrote:
>>> HFS is so so very old now. According to Wikipedia, HFS was
>>> introduced in 1985 and the successor HFS+ came out in January
>>> 1998. Mac OS dropped support for writing HFS in 2009 and dropped
>>> support for reading HFS in 2019 with macOS 10.15.
>>> 
>>> Grub's support for it doesn't survive contact with a fuzzer, and
>>> the issues involve some horrible mess of mutual recursion that
>>> would be time-consuming to sort out.
>>> 
>>> HFS has been disabled under lockdown since commit 1c15848838d9
>>> ("fs/hfs: Disable under lockdown") which was part of an earlier
>>> spin of security fixes.
>>> 
>>> I think it's time to consign HFS to the dustbin of history. It's
>>> firmly in the category of retrocomputing at this stage.
>>> 
>>> This should not affect HFS+.
>>> 
>>> There's a little bit of mess remaining: the macbless runtime
>>> command and HFS+ need the HFS headers for embedded volume support.
>>> I don't think that's really deployed any more, as it would have
>>> been part of the HFS->HFS+ transition, but I'm not really game to
>>> mess with either, in particular as macbless writes(!) to disk live.
>>> (I'm fairly sure the grub-macbless tool invokes code from the
>>> macbless module as well.)
>>> 
>>> Signed-off-by: Daniel Axtens <dja@axtens.net>
>> 
>> Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
>> 
>> Daniel, thank you for preparing this patch!
>> 
>> If I do not hear any major objections in the following weeks I will
>> merge this patch or a variant of it in the second half of September.
>
> We’re still formatting our /boot partitions for Debian PowerPC for PowerMacs 
> using HFS, so this change would be a breaking change for us.
>

Really, plain HFS, not HFS+? Wowsers!

Just to be clear, by PowerMacs you mean Macs with PowerPC chips, so
machines last produced around 2006?

Have you checked that you can't boot them with HFS+? Because HFS+
came in 1998, which was (AFAICT) pretty early on in the G3 lifecycle. So
I'd be really surprised if the firmware didn't support booting from
HFS+. I'd be very keen to hear.

Anyway, if I've understood correctly, the _most recent_ PowerMacs date
from around 16 years ago, and potentially the machines broken by this
would be even older. I still think that's in the domain of
retrocomputing and I don't understand the use case for running modern
software on something where the performance per watt is worse than a
recent raspberry pi.

Kind regards,
Daniel