On Thu, Dec 16, 2021 at 05:31:55PM -0600, Bob Pearson wrote:
> +/**
> + * rxe_pool_get_index - lookup object from index
> + * @pool: the object pool
> + * @index: the index of the object
> + *
> + * Returns: the object if the index exists in the pool
> + * and the reference count on the object is positive
> + * else NULL
> + */
> +void *rxe_pool_get_index(struct rxe_pool *pool, u32 index)
> {
> struct rxe_pool_elem *elem;
> void *obj;
>
> + elem = xa_load(&pool->xarray.xa, index);
> + if (elem && kref_get_unless_zero(&elem->ref_cnt))
> obj = elem->obj;
> + else
> obj = NULL;
>
> return obj;
> }
This has to hold some kind of lock to protect elem from free while
calling kref_get_unless_zero().
You can hold the xa_lock() around this, or use rcu_read_lock(), but
that requires using kfree_rcu to free the memory.
Jason
