[PATCH] slab IRQ fix

Patch from Manfred Spraul <manfred@colorfullife.com>

cache_alloc_refill() forgets to disable interrupts again on an error path.
This exposes us to slab corruption and it makes slab debugging go BUG (it
expects local irqs to be disabled).

mm/slab.c

@@ -1419,6 +1419,8 @@ static int cache_grow (kmem_cache_t * cachep, int flags)
 opps1:
 	kmem_freepages(cachep, objp);
 failed:
+	if (local_flags & __GFP_WAIT)
+		local_irq_disable();
 	return 0;
 }