On Tue, Mar 15, 2016 at 8:12 AM, Christoph Hellwig [off-list ref] wrote:

On Fri, Mar 11, 2016 at 05:24:45PM +0100, Andreas Gruenbacher wrote:

quoted

POSIX ACLs and RichACLs are different objects, with different members
and different algorithms operating on them. The only commonality is
that they are both kmalloc()ed, reference counted objects, and when an
inode is destroyed, both kinds of ACLs can be put in the same way,
avoiding an unnecessary if. What kind of common-code container beyond
that are you still dreaming about?

We still have a main object that is simply a list of ACEs.  But if that
doesn't work out (I suspect it should) I don't think the common base
object is a good idea.  It just leads to a lot of crazy container_of
calls.

There are two such container_of calls for POSIX ACLs in fs/jffs2/acl.c
[which could be replaced by get_acl()], two in fs/posix_acl.c for
POSIX ACLs, and two in fs/richacl.c for RichACLs. That's it.

If the common object abstraction doesn't work out we'll need
a procedural one instead that has common acl_* calls that decide what
do to based on the file system acl flag.

I've already made such abstractions where it made sense; if you can
find more, I don't see why we shouldn't add them.

Thanks,
Andreas