[ Upstream commit 1118dce7 ]

Export these symbols such that UBIFS can implement
->migratepage.

Cc: stable@vger.kernel.org
Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>