[PATCH 00/25] xfs_bmapi split and cleanups

[Christoph Hellwig]

This series, which is largely based on one that Dave published a couple month
ago, splits up the many armed hyrda called xfs_bmapi into multiple smaller
functions, and reduced stack usage in those pathes.

The main visible change to the rest of xfs is that there are three new
interfaces that replace xfs_bmapi:  xfs_bmapi_read to read extent maps,
xfs_bmapi_delay to add new unwritten extents, and xfs_bmapi to allocate
or convert real and unwrittent extents.