This series cleans up the xfs writepage code and then lifts it to fs/iomap/ so that it could be use by other file systems. I've been wanting to [do] this for a while so that I could eventually convert gfs2 over to it, but I never got to it. Now Damien has a new zonefs file system for semi-raw access to zoned block devices that would like to use the iomap code instead of reinventing it, so I finally had to do the work. Changes since v1: - rebased to latest iomap-for-next - fix up a comment to use iomap instead of imap - update a commit log
