Re: [PATCH v13 21/51] ext4: Add richacl feature flag

[Andreas Gruenbacher <agruenba@xxxxxxxxxx>]

Andreas,

On Wed, Nov 4, 2015 at 3:18 AM, Andreas Dilger <adilger@xxxxxxxxx> wrote:
> This patch confuses me.  I thought the whole point of INCOMPAT_RICHACL
> was that the filesystem should never, ever be mounted without ACL support
> because the ACLs will get confused without it.  In that case, it doesn't
> make sense to have a mount option that _has_ to be specified to mount the
> filesystem, and returns an error when trying to disable it.
>
> It makes more sense to just enable "acl" by default if INCOMPAT_RICHACL
> is set in the superblock and not need the mount option at all.

It's the commit message that's misleading here, I'll fix it. On
richacl filesystems, the acl mount option is always on. It's only on
POSIX ACL filesystems that the mount option can be used to turn POSIX
ACLs off (which arguably wasn't such a good idea, but there we have
it).

Thanks,
Andreas