GFS2: introduce bi_blocks for optimization

This patch introduces a new field in the bitmap structure called
bi_blocks. Its purpose is to save us from constantly multiplying
bi_len by the constant GFS2_NBBY. It also paves the way for more
optimization in a future patch.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

diff --git a/fs/gfs2/incore.h b/fs/gfs2/incore.h
index 26aabd7caba7edfd56c9d611df1732ac6b16a6a1..f1a3243dfaf2cdbba99a8352faca54dea3385a0e 100644 (file)
--- a/fs/gfs2/incore.h
+++ b/fs/gfs2/incore.h
@@ -71,6 +71,7 @@ struct gfs2_bitmap {
        u32 bi_offset;
        u32 bi_start;
        u32 bi_len;
+       u32 bi_blocks;
 };
 
 struct gfs2_rgrpd {

diff --git a/fs/gfs2/rgrp.c b/fs/gfs2/rgrp.c
index 7a6fa03bb32ab77791efdb2d51ef8366653e62ee..7d64a27683d925c5ab9a5b01dc389718a5f33408 100644 (file)
--- 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_len * GFS2_NBBY)
+       if (rbm->offset < rbm->bi->bi_blocks)
                return 0;
 
        /* Adjust for the size diff between gfs2_meta_header and gfs2_rgrp */
@@ -743,18 +743,21 @@ static int compute_bitstructs(struct gfs2_rgrpd *rgd)
                        bi->bi_offset = sizeof(struct gfs2_rgrp);
                        bi->bi_start = 0;
                        bi->bi_len = bytes;
+                       bi->bi_blocks = bytes * GFS2_NBBY;
                /* header block */
                } else if (x == 0) {
                        bytes = sdp->sd_sb.sb_bsize - sizeof(struct gfs2_rgrp);
                        bi->bi_offset = sizeof(struct gfs2_rgrp);
                        bi->bi_start = 0;
                        bi->bi_len = bytes;
+                       bi->bi_blocks = bytes * GFS2_NBBY;
                /* last block */
                } else if (x + 1 == length) {
                        bytes = bytes_left;
                        bi->bi_offset = sizeof(struct gfs2_meta_header);
                        bi->bi_start = rgd->rd_bitbytes - bytes_left;
                        bi->bi_len = bytes;
+                       bi->bi_blocks = bytes * GFS2_NBBY;
                /* other blocks */
                } else {
                        bytes = sdp->sd_sb.sb_bsize -
@@ -762,6 +765,7 @@ static int compute_bitstructs(struct gfs2_rgrpd *rgd)
                        bi->bi_offset = sizeof(struct gfs2_meta_header);
                        bi->bi_start = rgd->rd_bitbytes - bytes_left;
                        bi->bi_len = bytes;
+                       bi->bi_blocks = bytes * GFS2_NBBY;
                }
 
                bytes_left -= bytes;