int set_blocksize(struct block_device *bdev, int size)
{
- int oldsize;
-
/* Size must be a power of two, and between 512 and PAGE_SIZE */
if (size > PAGE_SIZE || size < 512 || (size & (size-1)))
return -EINVAL;
if (size < bdev_hardsect_size(bdev))
return -EINVAL;
- oldsize = bdev->bd_block_size;
- if (oldsize == size)
- return 0;
-
- /* Ok, we're actually changing the blocksize.. */
- sync_blockdev(bdev);
- bdev->bd_block_size = size;
- bdev->bd_inode->i_blkbits = blksize_bits(size);
- kill_bdev(bdev);
+ /* Don't change the size if it is same as current */
+ if (bdev->bd_block_size != size) {
+ sync_blockdev(bdev);
+ bdev->bd_block_size = size;
+ bdev->bd_inode->i_blkbits = blksize_bits(size);
+ kill_bdev(bdev);
+ }
return 0;
}
int sb_set_blocksize(struct super_block *sb, int size)
{
- int bits;
- if (set_blocksize(sb->s_bdev, size) < 0)
+ int bits = 9; /* 2^9 = 512 */
+
+ if (set_blocksize(sb->s_bdev, size))
return 0;
+ /* If we get here, we know size is power of two
+ * and it's value is between 512 and PAGE_SIZE */
sb->s_blocksize = size;
- for (bits = 9, size >>= 9; size >>= 1; bits++)
- ;
+ for (size >>= 10; size; size >>= 1)
+ ++bits;
sb->s_blocksize_bits = bits;
return sb->s_blocksize;
}