[PATCH] reiserfs v3 should throttle writers

[PATCH] reiserfs v3 should throttle writers

From: Chris Mason <mason@suse.com>

The v3 reiserfs_file_write func doesn't do any write throttling, which
leads to a variety of problems.  Here's a patch that makes
reiserfs_file_write call balance_dirty_pages_ratelimited, and exports that
func for module usage.