From 6aa7640f306a1dd0923d29d9190c5686907d5140 Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Wed, 11 Sep 2013 13:44:01 -0500 Subject: [PATCH] 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 Signed-off-by: Steven Whitehouse --- fs/gfs2/rgrp.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c index 69317435faa7..7a6fa03bb32a 100644 --- a/fs/gfs2/rgrp.c +++ b/fs/gfs2/rgrp.c @@ -262,7 +262,7 @@ static int gfs2_rbm_from_block(struct gfs2_rbm *rbm, u64 block) rbm->bi = rbm->rgd->rd_bits; rbm->offset = (u32)(rblock); /* Check if the block is within the first block */ - if (rbm->offset < (rbm->bi->bi_start + rbm->bi->bi_len) * GFS2_NBBY) + if (rbm->offset < rbm->bi->bi_len * GFS2_NBBY) return 0; /* Adjust for the size diff between gfs2_meta_header and gfs2_rgrp */ -- 2.20.1