[RFC / PATCH] ubiformat: make it work on mtd parts > 2GiB

[Sebastian Andrzej Siewior]

Artem Bityutskiy wrote:
> On Tue, 2009-02-10 at 11:17 +0100, Sebastian Andrzej Siewior wrote:
>>> I do not think you need to make eraseblock number and offset to be
>>> unsigned. In fact, I'd like them to be signed, because this is the same
>>> we have in the kernel (in UBI/UBIFS), and I'd like to be more or less
>>> consistent.
>> That is a point. However those things should never be negative so maybe we 
>> could change this in kernel.
> 
> They should not indeed be negative. However, signed numbers are just
> much more appropriate when you write the code, because you may put an
> error code there if something goes wrong.
> 
> For example, the UBIFS Garbage collector returns the freed eraseblock
> number in case of success or a negative error code in case of failure.
> Compare:
> 
> int ubifs_garbage_collect(struct ubifs_info *c)
> 
> and
> 
> int ubifs_garbage_collect(struct ubifs_info *c, unsigned int *leb)
> 
> The first prototype is what we have now. The second is what we would
> have to have to be able to return LEB number and error code.
> 
> And vs. changing UBI/UBIFS - that would be really a lot of work.

Yup, thanks for info. That makes sense.

> Anyway, the thing is that 31-bit should be more than enough for
> eraseblock number.
For now :)

> 
>> While we here, I get a couple of "compare between signed and unsigned" 
>> warnings from gcc. I tried to clean them up but I end up with huge patches 
>> similar to this one. Are you aware of those or you simply don't get them?
> 
> I'd rather shut the warnings up by an gcc option - is there such an
> option?
You are using -W which deprecated and -Wextra is doing the same thing. One 
of the things -Wextra does is adding -Wsign-compare so you have to add 
-Wno-sign-compare to stop that.

Sebastian
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