[PATCH] xfs: mark ARM OABI as incompatible in Kconfig

[PATCH] xfs: mark ARM OABI as incompatible in Kconfig

[Eric Sandeen]

The old ARM OABI's structure alignment quirks break xfs disk structures,
let's just move on and disallow it rather than playing whack-a-mole
for the infrequent times someone selects this old config, which is
usually during "make randconfig" tests.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---

diff --git a/fs/xfs/Kconfig b/fs/xfs/Kconfig
index e685299eb3d2..043624bd4ab2 100644
--- a/fs/xfs/Kconfig
+++ b/fs/xfs/Kconfig
@@ -2,6 +2,8 @@
 config XFS_FS
 	tristate "XFS filesystem support"
 	depends on BLOCK
+	# We don't support OABI structure alignment on ARM
+	depends on (!ARM || AEABI)
 	select EXPORTFS
 	select LIBCRC32C
 	select FS_IOMAP

Re: [PATCH] xfs: mark ARM OABI as incompatible in Kconfig

[Darrick J. Wong]

On Mon, Feb 24, 2020 at 04:49:12PM -0800, Eric Sandeen wrote:
> The old ARM OABI's structure alignment quirks break xfs disk structures,
> let's just move on and disallow it rather than playing whack-a-mole
> for the infrequent times someone selects this old config, which is
> usually during "make randconfig" tests.
> 
> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
> ---
> 
> diff --git a/fs/xfs/Kconfig b/fs/xfs/Kconfig
> index e685299eb3d2..043624bd4ab2 100644
> --- a/fs/xfs/Kconfig
> +++ b/fs/xfs/Kconfig
> @@ -2,6 +2,8 @@
>  config XFS_FS
>  	tristate "XFS filesystem support"
>  	depends on BLOCK
> +	# We don't support OABI structure alignment on ARM

Should this limitation be documented in the help screen?

> +	depends on (!ARM || AEABI)
>  	select EXPORTFS
>  	select LIBCRC32C
>  	select FS_IOMAP
> 

Re: [PATCH] xfs: mark ARM OABI as incompatible in Kconfig

[Eric Sandeen]

On 2/24/20 4:55 PM, Darrick J. Wong wrote:
> On Mon, Feb 24, 2020 at 04:49:12PM -0800, Eric Sandeen wrote:
>> The old ARM OABI's structure alignment quirks break xfs disk structures,
>> let's just move on and disallow it rather than playing whack-a-mole
>> for the infrequent times someone selects this old config, which is
>> usually during "make randconfig" tests.
>>
>> Signed-off-by: Eric Sandeen <sandeen@redhat.com>
>> ---
>>
>> diff --git a/fs/xfs/Kconfig b/fs/xfs/Kconfig
>> index e685299eb3d2..043624bd4ab2 100644
>> --- a/fs/xfs/Kconfig
>> +++ b/fs/xfs/Kconfig
>> @@ -2,6 +2,8 @@
>>  config XFS_FS
>>  	tristate "XFS filesystem support"
>>  	depends on BLOCK
>> +	# We don't support OABI structure alignment on ARM
> 
> Should this limitation be documented in the help screen?

Yeah probably.

But now looking at

aa2dd0ad4d6d xfs: remove __arch_pack

hch indicates that some non-arm architectures have similar problems,
so is there any point to excluding this one config on this one arch?

-Eric

Re: [PATCH] xfs: mark ARM OABI as incompatible in Kconfig

[Christoph Hellwig]

On Mon, Feb 24, 2020 at 04:58:20PM -0800, Eric Sandeen wrote:
> Yeah probably.
> 
> But now looking at
> 
> aa2dd0ad4d6d xfs: remove __arch_pack
> 
> hch indicates that some non-arm architectures have similar problems,
> so is there any point to excluding this one config on this one arch?

Yes, I think we just need to be more careful with our newly added
structure layouts and whenever we do a major reorganization of an
existing one.