xfs: send warning of project quota to userspace via netlink

Linux's quota subsystem has an ability to handle project quota. This
commit just utilizes the ability from xfs side.  dbus-monitor and
quota_nld shipped as part of quota-tools can be used for testing.
See the patch posting on the XFS list for details on testing.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

fs/xfs/xfs_trans_dquot.c

@@ -572,12 +572,16 @@ xfs_quota_warn(
 	struct xfs_dquot	*dqp,
 	int			type)
 {
-	/* no warnings for project quotas - we just return ENOSPC later */
+	enum quota_type qtype;
+
 	if (dqp->dq_flags & XFS_DQ_PROJ)
-		return;
-	quota_send_warning(make_kqid(&init_user_ns,
-				     (dqp->dq_flags & XFS_DQ_USER) ?
-				     USRQUOTA : GRPQUOTA,
+		qtype = PRJQUOTA;
+	else if (dqp->dq_flags & XFS_DQ_USER)
+		qtype = USRQUOTA;
+	else
+		qtype = GRPQUOTA;
+
+	quota_send_warning(make_kqid(&init_user_ns, qtype,
 				     be32_to_cpu(dqp->q_core.d_id)),
 			   mp->m_super->s_dev, type);
 }