Hi all, this is a slight rework of the patches from Andreas to prepare for gfs2 using the iomap code. Note: I'd like to start with an immutable branch for iomap patches in either the XFS tree or a tree of mine at the beginning of the merge window so that we have a common base for the GFS2 and XFS iomap work. Changes since v1: - move code to a different spot in iomap.c to prefer for readpages inline data support - add a forward declaration for struct page to iomap.h - fix a typo in the dax_dev/bdev unioning - fix a comment typo
