Re: [PATCH v2] ext3, ext4: do_split() fix loop, with obviousunsigned wrap

From: Theodore Tso
Date: Tue Dec 02 2008 - 16:58:20 EST

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.

- Ted
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at