Re: [PATCH v2] ext3, ext4: do_split() fix loop, with obvious unsignedwrap

[Bill Davidsen]

Theodore Tso wrote:
> On Tue, Dec 02, 2008 at 12:08:38PM -0500, Bill Davidsen wrote:
>   
> > Sorry, you are reading it wrong, the i values inside the loop are  
> > identical to those in the original. The value of i starts at count, and  
> > the test comes *before* the value is used inside the loop. The values of  
> > i inside the loop start at count-1 and go to zero, just as it did in the  
> > original. That's why the "i--" is there, the test is on the  
> > unincremented value range count to one, but the value inside the loop is  
> > correct (or at least is the same as the original patch).
> >     
>
> You're right; my bad.  But with something like this:
>
>   
> > > > +	for (i = count; i--; ) {
> > > >         
>
> ...where there is no third part of the for loop, and a decrement in
> the second part of the loop, just for clarity's sake, it's much better
> to write it as a while loop.
>   

I seriously disagree on that, writing it as a for makes it totally clear 
that the index initialization is part of the loop.
I know, looks funny, not the way we have always done it, not invented 
here...

--
Bill Davidsen <davidsen@xxxxxxx>
 "Woe unto the statesman who makes war without a reason that will still
 be valid when the war is over..." Otto von Bismark 


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