Commit 266deeea authored by Niklas Schnelle's avatar Niklas Schnelle Committed by David S. Miller
Browse files

s390/ism: Do not unregister clients with registered DMBs 



When ism_unregister_client() is called but the client still has DMBs
registered it returns -EBUSY and prints an error. This only happens
after the client has already been unregistered however. This is
unexpected as the unregister claims to have failed. Furthermore as this
implies a client bug a WARN() is more appropriate. Thus move the
deregistration after the check and use WARN().

Fixes: 89e7d2ba ("net/ism: Add new API for client registration")
Signed-off-by: default avatarNiklas Schnelle <schnelle@linux.ibm.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 76631ffa

drivers/s390/net/ism_drv.c

+13 −10
Original line number Diff line number Diff line
@@ -96,29 +96,32 @@ int ism_unregister_client(struct ism_client *client) 
	int rc = 0;



	mutex_lock(&ism_dev_list.mutex);

	mutex_lock(&clients_lock);

	clients[client->id] = NULL;

	if (client->id + 1 == max_client)

		max_client--;

	mutex_unlock(&clients_lock);

	list_for_each_entry(ism, &ism_dev_list.list, list) {

		spin_lock_irqsave(&ism->lock, flags);

		/* Stop forwarding IRQs and events */

		ism->subs[client->id] = NULL;

		for (int i = 0; i < ISM_NR_DMBS; ++i) {

			if (ism->sba_client_arr[i] == client->id) {

				pr_err("%s: attempt to unregister client '%s'"

				       "with registered dmb(s)\n", __func__,

				       client->name);

				WARN(1, "%s: attempt to unregister '%s' with registered dmb(s)\n",

				     __func__, client->name);

				rc = -EBUSY;

				goto out;

				goto err_reg_dmb;

			}

		}

		spin_unlock_irqrestore(&ism->lock, flags);

	}

out:

	mutex_unlock(&ism_dev_list.mutex);



	mutex_lock(&clients_lock);

	clients[client->id] = NULL;

	if (client->id + 1 == max_client)

		max_client--;

	mutex_unlock(&clients_lock);

	return rc;



err_reg_dmb:

	spin_unlock_irqrestore(&ism->lock, flags);

	mutex_unlock(&ism_dev_list.mutex);

	return rc;

}

EXPORT_SYMBOL_GPL(ism_unregister_client);