GFS2: optimize rbm_from_block wrt bi_start
authorBob Peterson <rpeterso@redhat.com>
Wed, 11 Sep 2013 18:44:01 +0000 (13:44 -0500)
committerSteven Whitehouse <swhiteho@redhat.com>
Tue, 17 Sep 2013 09:14:39 +0000 (10:14 +0100)
commit6aa7640f306a1dd0923d29d9190c5686907d5140
treede2d5f54bbbeccd2aaa996eeceba8bd696b7d978
parent0d0d110720d7960b77c03c9f2597faaff4b484ae
GFS2: optimize rbm_from_block wrt bi_start

In function gfs2_rbm_from_block, it starts by checking if the block
falls within the first bitmap. It does so by checking if the rbm's
offset is less than (rbm->bi->bi_start + rbm->bi->bi_len) * GFS2_NBBY.
However, the first bitmap will always have bi_start==0. Therefore
this is an unnecessary calculation in a function that gets called
billions of times. This patch removes the reference to bi_start.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
fs/gfs2/rgrp.c