[PATCH v4 22/30] ovl: implement set acl method

[Miklos Szeredi]

On Thu, 29 Sept 2022 at 17:31, Christian Brauner <brauner at kernel.org> wrote:
>
> The current way of setting and getting posix acls through the generic
> xattr interface is error prone and type unsafe. The vfs needs to
> interpret and fixup posix acls before storing or reporting it to
> userspace. Various hacks exist to make this work. The code is hard to
> understand and difficult to maintain in it's current form. Instead of
> making this work by hacking posix acls through xattr handlers we are
> building a dedicated posix acl api around the get and set inode
> operations. This removes a lot of hackiness and makes the codepaths
> easier to maintain. A lot of background can be found in [1].
>
> In order to build a type safe posix api around get and set acl we need
> all filesystem to implement get and set acl.
>
> Now that we have added get and set acl inode operations that allow easy
> access to the dentry we give overlayfs it's own get and set acl inode
> operations.
>
> The set acl inode operation is duplicates most of the ovl posix acl
> xattr handler. The main difference being that the set acl inode
> operation relies on the new posix acl api. Once the vfs has been
> switched over the custom posix acl xattr handler will be removed
> completely.
>
> Note, until the vfs has been switched to the new posix acl api this
> patch is a non-functional change.
>
> Link: https://lore.kernel.org/all/20220801145520.1532837-1-brauner@kernel.org [1]
> Signed-off-by: Christian Brauner (Microsoft) <brauner at kernel.org>

Acked-by: Miklos Szeredi <mszeredi at redhat.com>

Thanks,
Miklos