Re: [9fans] venti

[erik quanstrom <quanstro@quanstro.net>]

> I do sometimes get errors like this from my fossil server:
> 	could not write super block; waiting 10 seconds
> 	blistAlloc: called on clean block
> but I've been assuming they are benign.  Am I wrong?

i looked into this.

/sys/src/cmd/fossil/cache.c:1210,1217
		if(p->index < 0){
			/*
			 * We don't know how to temporarily undo
			 * b's dependency on bb, so just don't write b yet.
			 */
			if(0) fprint(2, "blockWrite skipping %d %x %d %d; need to write %d %x %d\n",
				b->part, b->addr, b->vers, b->l.type, p->part, p->addr, bb->vers);
			return 0;
		}

what if bb == b?

it'd be interesting to see what that outputs with if(1).
i think _cacheLocalLookup is finding the superblock
itself.  perhaps no write between snaps meaning that
only the sb itself is dirty?

- erik