Re: epic fsck SIGSEGV!

From: Linus Torvalds <torvalds@linux-foundation.org>
Date: Dec 11, 2008, 20:18 UTC
Message-ID: <alpine.LFD.2.00.0812111212510.3340@localhost.localdomain>
In-Reply-To: <alpine.LFD.2.00.0812110928060.3340@localhost.localdomain>

On Thu, 11 Dec 2008, Linus Torvalds wrote:

> 
> But obviously the true test for fsck is some complex corruption, and I 
> didn't test that. I can't imagine that it introduces any new problems 
> though - but the bugs you can't imagine are always the worst ones ;)

Btw, even if it doesn't introduce any bugs, it _does_ change the order that we traverse things in. It shouldn't matter, of course, but because it always picks the last entry from the object array (it really treats the array as a stack), it ends up traversing parents of commits (and the entries in trees) by looking at the last parent (or entry) first.

The whole two-phase thing also means that rather traverse the references as we find them, we'll end up traversing things later in one group. Again, access ordering will change.

Absolutely nothing should care about this from a correctness angle, of course, but I thought I'd point it out because I think it will change the order that we print out errors in.

So if somebody has some test-case, and you get different output before-and-after, it's not necessarily any indication of a problem, just an effect of doing object traversal in slightly different order.

		Linus