md: Make calc_dev_sboffset() return a sector count.

As BLOCK_SIZE_BITS is 10 and

	MD_NEW_SIZE_SECTORS(2 * x) = 2 * NEW_SIZE_BLOCKS(x),

the return value of calc_dev_sboffset() doubles. Fix up all three
callers accordingly.

Signed-off-by: Andre Noll <maan@systemlinux.org>
Signed-off-by: Neil Brown <neilb@suse.de>

drivers/md/md.c

@@ -347,10 +347,11 @@ static struct mdk_personality *find_pers(int level, char *clevel)
 	return NULL;
 }
 
+/* return the offset of the super block in 512byte sectors */
 static inline sector_t calc_dev_sboffset(struct block_device *bdev)
 {
-	sector_t size = bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
-	return MD_NEW_SIZE_BLOCKS(size);
+	sector_t num_sectors = bdev->bd_inode->i_size / 512;
+	return MD_NEW_SIZE_SECTORS(num_sectors);
 }
 
 static sector_t calc_num_sectors(mdk_rdev_t *rdev, unsigned chunk_size)
@@ -673,7 +674,7 @@ static int super_90_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev, int minor_version
 	 *
 	 * It also happens to be a multiple of 4Kb.
 	 */
-	sb_offset = calc_dev_sboffset(rdev->bdev);
+	sb_offset = calc_dev_sboffset(rdev->bdev) / 2;
 	rdev->sb_offset = sb_offset;
 
 	ret = read_disk_sb(rdev, MD_SB_BYTES);
@@ -1006,7 +1007,7 @@ super_90_rdev_size_change(mdk_rdev_t *rdev, unsigned long long size)
 	size *= 2; /* convert to sectors */
 	if (rdev->mddev->bitmap_offset)
 		return 0; /* can't move bitmap */
-	rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
+	rdev->sb_offset = calc_dev_sboffset(rdev->bdev) / 2;
 	if (!size || size > rdev->sb_offset*2)
 		size = rdev->sb_offset*2;
 	md_super_write(rdev->mddev, rdev, rdev->sb_offset << 1, rdev->sb_size,
@@ -4356,7 +4357,7 @@ static int add_new_disk(mddev_t * mddev, mdu_disk_info_t *info)
 			printk(KERN_INFO "md: nonpersistent superblock ...\n");
 			rdev->sb_offset = rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;
 		} else 
-			rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
+			rdev->sb_offset = calc_dev_sboffset(rdev->bdev) / 2;
 		rdev->size = calc_num_sectors(rdev, mddev->chunk_size) / 2;
 
 		err = bind_rdev_to_array(rdev, mddev);
@@ -4423,7 +4424,7 @@ static int hot_add_disk(mddev_t * mddev, dev_t dev)
 	}
 
 	if (mddev->persistent)
-		rdev->sb_offset = calc_dev_sboffset(rdev->bdev);
+		rdev->sb_offset = calc_dev_sboffset(rdev->bdev) / 2;
 	else
 		rdev->sb_offset =
 			rdev->bdev->bd_inode->i_size >> BLOCK_SIZE_BITS;