[Ocfs2-tools-devel] [PATCH 05/23] libocfs2: Fill out the ocfs2_XXX_to_YYY() conversion APIs.

[Mark Fasheh]

On Mon, Aug 11, 2008 at 05:31:57PM -0700, Joel Becker wrote:
> ocfs2 often needs to convert sizes from clusters to blocks to bytes.  We
> only provided a few of these functions in ocfs2.h.  This adds the
> complete set:
> 
> ocfs2_clusters_to_blocks()
> ocfs2_blocks_to_clusters()
> ocfs2_clusters_to_bytes()
> ocfs2_bytes_to_clusters()
> ocfs2_blocks_to_bytes()
> ocfs2_bytes_to_blocks()
> ocfs2_clusters_in_blocks()
> ocfs2_clusters_in_bytes()
> ocfs2_blocks_in_bytes()
> 
> The container functions (ocfs2_XXX_in_YYY()) only go one direction; the
> other direction is answered correctly by ocfs2_YYY_to_XXX().
> 
> While we're here, we standardize the handling of value overflows.  Some
> of the existing functions would cast an uint64_t to uint32_t without
> checking.  The caller just gets the lower 32bits, regardless of how they
> wrapped.  All functions now return UINTxx_MAX on overflow.  This is not
> a value that can be checked - UINTxx_MAX could have been the exact
> answer - but it is a safer return than the lower 32bits.  Users of this
> function should prevent overflow by checking bounds before calling the
> conversion.

Great, that's exactly how things should happen imho.

Signed-off-by: Mark Fasheh <mfasheh at suse.com>

--
Mark Fasheh