Re: A few WARNS6 cleanups

[Peter Schuller <peter.schuller@xxxxxxxxxxxx>]

> But, consider where some of these problems reside.  From ufs/fs.h:
> 
> /*
>  * Super block for an FFS file system.
>  */
> struct fs {
> 	...
> 	int32_t	 fs_size;		/* number of blocks in fs */
> 	int32_t	 fs_dsize;		/* number of data blocks in fs */
> 	int32_t	 fs_ncg;		/* number of cylinder groups */
> 	int32_t	 fs_bsize;		/* size of basic blocks in fs */
> 	int32_t	 fs_fsize;		/* size of frag blocks in fs */
> 	int32_t	 fs_frag;		/* number of frags in a block in fs */
> 	...
> 
> None of these can ever be below zero, but they all must be signed for
> the sake of compatibility.

Without having looked at this stuff beyond newfs, it sounds to me like the
fundamental problem is the lack of a layer of abstraction between the on-disk
format and the format used for internal processing in the tools/kernel.

In my (not so informed, given my lack of experience with kernel/os programming)
opinion the proper fix would be to abstract away this whole thing to
deal with data types and structures that make logical and practical sence (e.g.,
uint64_t[1] to remain future proof). One would then have properly defined and
*explicit* bounds checking where it can be easily verified what is allowed
and what isn't. The limits of the underlying structure (on-disk for example)
then becomes an implementation detail rather than a design issue that prevents
proper writing of utilities.

[1] Or some generice size typedef; but then one run into a whole set of problems
with printf() and such not being independent of the actual types.

-- 
/ Peter Schuller, InfiDyne Technologies HB

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