[XFS updates] XFS development tree branch, master, updated. v2.6.28-rc3-20838-g5123bc3

[Felix Blyakher]

On Mar 31, 2009, at 2:11 AM, Christoph Hellwig wrote:

> On Mon, Mar 30, 2009 at 10:23:50PM -0500, xfs at oss.sgi.com wrote:
>> commit 8b112171734c791afaf43ccc8c6ec492e7006e44
>> Author: Felix Blyakher <felixb at sgi.com>
>> Date:   Fri Mar 27 17:28:43 2009 -0500
>>
>>    xfs: increase the maximum number of supported ACL entries
>>
>>    With big installation current 25 maximum number of
>>    supported ACL entries is not enough any more.
>>    Increase the limit to 100.
>>
>>    Signed-off-by: Felix Blyakher <felixb at sgi.com>
>
> Can you please send your patches through the usual review channels?

That wasn't intended for check in yet.

> The reason why we haven't done this before is becuase the obvious
> solutions break the disk format,

That was exactly the reason I hadn't sent it for review yet.
I stop short of sending it for review realizing that it's not
complete and more work may be needed. Unfortunately, it was
left in my tree.

> so this at least needs an explanation
> why it doesn't.

It does, though it's not as severe as other disk format changes.
I don't have a final solution yet, but since it's already escaped
in public, I may as well show my current thinking, and invite
comments.
So, the older kernels would be able to mount and work with the
new filesystem, with exception of seeing only first 25 ACL
entries. The user may still would like to mount it as such
confirming that he aware of consequences. This feature validation
would not follow the current scheme of black and white. With
the presence of the force_mount (new) option, we emit a warning
and allow to mount.
Comments?

Felix