Re: buffer_head.b_bsize type

[Andries Brouwer (aebr@win.tue.nl)]

On Thu, May 29, 2003 at 04:28:41AM -0700, William Lee Irwin III wrote:

> The thought behind my comment was that it didn't make sense to allow
> the representation to go negative. There of course shouldn't ever be
> any need to allow >= 2GB b_size to be representable.

Not about this particular case, but as a general remark:
Use of unsigned is dangerous - use of int is far preferable,
everywhere that is possible.

With ints the test a+b > c is equivalent to the test a > c-b.
Intuition works.

As soon as there is some unsigned in an expression comparisons
get counterintuitive because -1 is very large.
Thus, 1+sizeof(int) > 3 is true, but 1 > 3-sizeof(int) is false.

It has happened several times that kernel code was broken because
some variable (that always was nonnegative) was made unsigned.

Andries

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