From 1d6165851cd8e3f919d446cd6da35dee44e8837e Mon Sep 17 00:00:00 2001
From: Dmitry Monakhov <dmonakhov@openvz.org>
Date: Wed, 27 Jan 2010 22:44:36 +0300
Subject: [PATCH] block: fix bio_add_page for non trivial merge_bvec_fn case

We have to properly decrease bi_size in order to merge_bvec_fn return
right result.  Otherwise this result in false merge rejects for two
absolutely valid bio_vecs.  This may cause significant performance
penalty for example fs_block_size == 1k and block device is raid0 with
small chunk_size = 8k. Then it is impossible to merge 7-th fs-block in
to bio which already has 6 fs-blocks.

Cc: <stable@kernel.org>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
---
Reading git-format-patch failed