Re: [PATCH] fix dir2 shortform structures on ARM old ABI

[Eric Sandeen <sandeen@sandeen.net>]

Eric Sandeen wrote:
> Timothy Shimmin wrote:
>> David Chinner wrote:
>>> On Fri, May 02, 2008 at 03:55:45PM -0500, Eric Sandeen wrote:
>>>> Eric Sandeen wrote:
>>>>> Eric Sandeen wrote:
>>>>>> This should fix the longstanding issues with xfs and old ABI
>>>>>> arm boxes, which lead to various asserts and xfs shutdowns,
>>>>>> and for which an (incorrect) patch has been floating around
>>>>>> for years.  (Said patch made ARM internally consistent, but
>>>>>> altered the normal xfs on-disk format such that it looked
>>>>>> corrupted on other architectures):
>>>>>> http://lists.arm.linux.org.uk/lurker/message/20040311.002034.5ecf21a2.html
>>>>> ping again...
>>>> ping #3...
>>> <sigh>

Guys, this is SIMPLE, SAFE, and it fixes a CORRUPTION BUG.

is it EVER going to get checked in?

-Eric

>>> Looks like if I don't pick it up then nobody is going to answer.
>>> I'll run it through my ia64 and x86_64 test boxes and if it's ok
>>> then I'll commit it.
>>>
>> As it only defines __arch_pack for __arm__,
>> I literally can't see how on earth it won't pass for ia64 and x86-64,
>> though I realise (I guess) we need to test to be sure :)
>>
>> So Eric tested this on qemu-arm with success.
>> And there was a little debate over whether ARM-EABI would work
>> currently in XFS, 
>> with Luca Olivetti saying in one kernel he has success and in another
>> he doesn't. And Andre Draszik saying that for ARM-EABI it wouldn't
>> work.
> 
> The patch should only affect behavior on *old* abi:
> 
> +#if defined(__arm__) && !defined(__ARM_EABI__)
> 
> it is the only one with the unique alignment that matters here.
> 
> There *is* still another issue on some arm chips related to processor
> cache flushing; I didn't see the problem in qemu because it the emulator
> does not have this behavior.
> 
> But, it's a separate issue from the structure alignment this patch
> addresses.
> 
> One thing at a time. :)
> 
> Thanks,
> 
> -Eric
> 
>> That aside, Eric has tried out on ARM without EABI (old ABI) and has had success,
>> so it is at least useful for this case.
>> I don't see us doing any arm testing for this ourselves :)
>>
>> --Tim
>>
> 
>