Add ACL_IS_TRIVIAL and ACL_IS_DIR flags as ACL-wide flags
in the system.nfs4_acl_xdr generated on getxattr requests.
This are non-RFC flags that are useful for userspace applications
(especially the ACL_IS_TRIVIAL flag as it can be used to avoid
relatively expensive ACL-related operations).
Also add system.nfs4_acl_xdr to xattr results if ACL is not trivial.
This duplicates POSIX ACL behavior where whether an ACL is
set on a path can be determined via listxattr(). Since the ACL
is not actually removed, we check whether the ZFS_ACL_TRIVIAL
is set. If the flag is not set, then we omit the xattr name from
the list. This allows users to determine whether ACL is trivial from
listxattr().
Signed-off-by: Andrew Walker <awalker@ixsystems.com>
29d6360344