PATCH [0/2] xfs: use the scalable vmap API

[Alex Elder <aelder@xxxxxxx>]

As requested, I am planning to re-apply Nick Piggin's commits that
replace XFS's vmap batching with the use of the scalable vmap API.
In order to avoid a later merge conflict, these patches apply
against v2.6.34-rc1 (I am going to update the XFS master branch
to that later today).

Though I made only minor modifications, I'm posting them for
review before recommitting them.

                                        -Alex