Re: [PATCH 08/10] RDMA/rxe: Use driver_unregister and new unregistration API

[Jason Gunthorpe <jgg@xxxxxxxx>]

On Tue, Feb 12, 2019 at 09:12:54PM -0700, Jason Gunthorpe wrote:

> diff --git a/drivers/infiniband/sw/rxe/rxe_pool.c b/drivers/infiniband/sw/rxe/rxe_pool.c
> index cd3f14629ba873..30470fb8c17a84 100644
> +++ b/drivers/infiniband/sw/rxe/rxe_pool.c
> @@ -398,25 +398,27 @@ void *rxe_alloc(struct rxe_pool *pool)
>  	kref_get(&pool->ref_cnt);
>  	read_unlock_irqrestore(&pool->pool_lock, flags);
>  
> -	kref_get(&pool->rxe->ref_cnt);
> +	if (!ib_device_try_get(&pool->rxe->ib_dev))
> +		goto out_put_pool;
>  
>  	if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
> -		goto out_put_pool;
> +		goto out_cnt;
>  
>  	elem = kmem_cache_zalloc(pool_cache(pool),
>  				 (pool->flags & RXE_POOL_ATOMIC) ?
>  				 GFP_ATOMIC : GFP_KERNEL);
>  	if (!elem)
> -		goto out_put_pool;
> +		goto out_cnt;
>  
>  	elem->pool = pool;
>  	kref_init(&elem->ref_cnt);
>  
>  	return elem;
>  
> -out_put_pool:
> +out_cnt:
>  	atomic_dec(&pool->num_elem);
> -	rxe_dev_put(pool->rxe);
> +	ib_device_put(&pool->rxe->ib_dev);
> +out_put_pool:
>  	rxe_pool_put(pool);
>  	return NULL;
>  }
> @@ -464,7 +466,7 @@ void rxe_elem_release(struct kref *kref)
>  	if (!(pool->flags & RXE_POOL_NO_ALLOC))
>  		kmem_cache_free(pool_cache(pool), elem);
>  	atomic_dec(&pool->num_elem);
> -	rxe_dev_put(pool->rxe);
> +	ib_device_put(&pool->rxe->ib_dev);
>  	rxe_pool_put(pool);
>  }

There is a small conflict with latest for-next here, this hunk is
needed:

@@ -435,19 +437,21 @@ int rxe_add_to_pool(struct rxe_pool *pool, struct rxe_pool_entry *elem)
        kref_get(&pool->ref_cnt);
        read_unlock_irqrestore(&pool->pool_lock, flags);
 
-       kref_get(&pool->rxe->ref_cnt);
+       if (!ib_device_try_get(&pool->rxe->ib_dev))
+               goto out_put_pool;
 
        if (atomic_inc_return(&pool->num_elem) > pool->max_elem)
-               goto out_put_pool;
+               goto out_cnt;
 
        elem->pool = pool;
        kref_init(&elem->ref_cnt);
 
        return 0;
 
-out_put_pool:
+out_cnt:
        atomic_dec(&pool->num_elem);
-       rxe_dev_put(pool->rxe);
+       ib_device_put(&pool->rxe->ib_dev);
+out_put_pool:
        rxe_pool_put(pool);
        return -EINVAL;
 }

Jason