> + spin_lock_init(&dev->zone_res_lock);
> + if (dev->memory_backed)
> dev->zone_locks = bitmap_zalloc(dev->nr_zones, GFP_KERNEL);
> + else
> + dev->zone_locks = kmalloc_array(dev->nr_zones,
> + sizeof(spinlock_t), GFP_KERNEL);
> + if (!dev->zone_locks) {
Using the same pointer for different types is pretty horrible. At very
least we should use a union.
But I think we'd end up with less contention if we add a new
struct nullb_zone
that contains the fields of blk_zone that we actuall care about plus:
union {
spinlock_t spinlock;
mutex_t mutex;
}
and then use the proper lock primitive also for the memory backed case.
