Re: [PATCH v2 1/3] block: provide helpers for reading block count

[Davidlohr Bueso]

On Thu, 23 Jun 2016, Arnd Bergmann wrote:

> Several drivers use an expensive do_div() to compute the number
> of logical or physical blocks in a blockdev, which can be done
> more efficiently using a shift, since the blocksize is always
> a power of two number.
>
> Let's introduce bdev_logical_block_count() and bdev_physical_block_count()
> helper functions mirroring the bdev_logical_block_size() and
> bdev_physical_block_size() interfaces for the block size.

> @@ -1226,6 +1226,13 @@ static inline unsigned short bdev_logical_block_size(struct block_device *bdev)
> 	return queue_logical_block_size(bdev_get_queue(bdev));
> }
>
> +static inline sector_t bdev_logical_block_count(struct block_device *bdev)

Curious, why not just return u64 instead for all these instead of sector_t (ie
dealing with lba, it reads weird)?

Thanks,
Davidlohr