[PATCH 0/10] XFS: clean up sync code

[Dave Chinner <david@xxxxxxxxxxxxx>]

xfs_sync and xfs_syncsub are multiplexed interfaces that
shares relatively little code between callers. because it is
a multiplexed interface, it's hard to tell what is executed
in each context it is called.

Factor out the sync code and explicitly call the sync functions
needed rather than the multiplexed interfaces. Once this is
done, we can remove xfs_syncsub and xfs_sync altogether.