md: raid0_make_request(): Replace chunksize_bits by chunksect_bits.
authorAndre Noll <maan@systemlinux.org>
Thu, 8 Jan 2009 21:31:06 +0000 (08:31 +1100)
committerNeilBrown <neilb@suse.de>
Thu, 8 Jan 2009 21:31:06 +0000 (08:31 +1100)
As ffz(~(2 * x)) = ffz(~x) + 1, we have

chunksect_bits = chunksize_bits + 1.

Fixup all users accordingly.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: NeilBrown <neilb@suse.de>
drivers/md/raid0.c

index 8ac6488..62a193c 100644 (file)
@@ -387,7 +387,7 @@ static int raid0_stop (mddev_t *mddev)
 static int raid0_make_request (struct request_queue *q, struct bio *bio)
 {
        mddev_t *mddev = q->queuedata;
-       unsigned int sect_in_chunk, chunksize_bits,  chunk_size, chunk_sects;
+       unsigned int sect_in_chunk, chunksect_bits, chunk_size, chunk_sects;
        raid0_conf_t *conf = mddev_to_conf(mddev);
        struct strip_zone *zone;
        mdk_rdev_t *tmp_dev;
@@ -409,7 +409,7 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 
        chunk_size = mddev->chunk_size >> 10;
        chunk_sects = mddev->chunk_size >> 9;
-       chunksize_bits = ffz(~chunk_size);
+       chunksect_bits = ffz(~chunk_sects);
        block = bio->bi_sector >> 1;
        
 
@@ -446,15 +446,15 @@ static int raid0_make_request (struct request_queue *q, struct bio *bio)
 
 
        {
-               sector_t x =  (block - zone->zone_offset) >> chunksize_bits;
+               sector_t x =  (block - zone->zone_offset) >> (chunksect_bits - 1);
 
                sector_div(x, zone->nb_dev);
                chunk = x;
 
-               x = block >> chunksize_bits;
+               x = block >> (chunksect_bits - 1);
                tmp_dev = zone->dev[sector_div(x, zone->nb_dev)];
        }
-       rsect = (((chunk << chunksize_bits) + zone->dev_offset)<<1)
+       rsect = (((chunk << (chunksect_bits - 1)) + zone->dev_offset)<<1)
                + sect_in_chunk;
  
        bio->bi_bdev = tmp_dev->bdev;