[PATCH V3 10/10] nvmet: use xarray for ctrl ns storing

[Christoph Hellwig]

> index 9cdc39c8b729..2908acc7b1e2 100644
> --- a/drivers/nvme/target/core.c
> +++ b/drivers/nvme/target/core.c
> @@ -115,13 +115,14 @@ u16 nvmet_zero_sgl(struct nvmet_req *req, off_t off, size_t len)
>  
>  static unsigned int nvmet_max_nsid(struct nvmet_subsys *subsys)
>  {
> -	struct nvmet_ns *ns;
> +	unsigned long nsid = 0;
> +	struct nvmet_ns *cur;
> +	unsigned long idx;
>  
> -	if (list_empty(&subsys->namespaces))
> -		return 0;
> +	xa_for_each(&subsys->namespaces, idx, cur)
> +		nsid = cur->nsid;
>  
> -	ns = list_last_entry(&subsys->namespaces, struct nvmet_ns, dev_link);
> -	return ns->nsid;
> +	return nsid;
>  }

If Matthew wants to add a helper to return the highest id for an xarray
this would be the place to use it.


> +	ret = xa_insert(&subsys->namespaces, ns->nsid, ns, GFP_KERNEL);
> +	if (ret)
> +		goto out_dev_put;

I don't think out_dev_put is enough here as that fails to tear down
ns->ref.