xfs: factor mapping out of xfs_do_writepage

Separate out the bufferhead based mapping from the writepage code so
that we have a clear separation of the page operations and the
bufferhead state.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Dave Chinner 2016-02-15 17:21:37 +11:00 • committed by Dave Chinner
commit bfce7d2e2d