On Mon, Aug 1, 2016 at 11:27 PM, Seth Forshee
<seth.forshee-Z7WLFzj8eWMS+FvcfC7Uqw@public.gmane.org> wrote:

> Support posix acls in fuse only when CONFIG_FUSE_FS_POSIX_ACL=y
> and default_permissions is used for the filesystem. When
> default_permissions is not used fuse cannot meaninfully support
> cals, as fuse_permission() only sends FUSE_PERMISSION from the
> access, faccessat, chdir, fchdir, and chroot system calls.
> Therefore whenever CONFIG_FUSE_FS_POSIX_ACL=n or
> default_permissions is not used fuse will return -EOPNOTSUPP
> whenever posix acl xattrs are read or written.

Which is breaking backward compatibilty.  Please don't do this without
good reason.

Even having "default_permissions" change behavior might cause
problems.