netdevsim: Forbid devlink reload when adding or deleting ports

In order to remove complexity in devlink core related to
devlink_reload_enable/disable, let's rewrite new_port/del_port
logic to rely on internal to netdevsim lcok.

We should protect only reload_down flow because it destroys nsim_dev,
which is needed for nsim_dev_port_add/nsim_dev_port_del to hold
port_list_lock.

Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/netdevsim/bus.c b/drivers/net/netdevsim/bus.c
index ff01e5bdc72ee926540b238c277919bc042660f4..a29ec264119dc7d71d50302f35e8fa9661249358 100644 (file)
--- a/drivers/net/netdevsim/bus.c
+++ b/drivers/net/netdevsim/bus.c
@@ -183,8 +183,6 @@ new_port_store(struct device *dev, struct device_attribute *attr,
               const char *buf, size_t count)
 {
        struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
-       struct nsim_dev *nsim_dev = dev_get_drvdata(dev);
-       struct devlink *devlink;
        unsigned int port_index;
        int ret;
 
@@ -195,12 +193,10 @@ new_port_store(struct device *dev, struct device_attribute *attr,
        if (ret)
                return ret;
 
-       devlink = priv_to_devlink(nsim_dev);
+       if (!mutex_trylock(&nsim_bus_dev->nsim_bus_reload_lock))
+               return -EBUSY;
 
-       mutex_lock(&nsim_bus_dev->nsim_bus_reload_lock);
-       devlink_reload_disable(devlink);
        ret = nsim_dev_port_add(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
-       devlink_reload_enable(devlink);
        mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
        return ret ? ret : count;
 }
@@ -212,8 +208,6 @@ del_port_store(struct device *dev, struct device_attribute *attr,
               const char *buf, size_t count)
 {
        struct nsim_bus_dev *nsim_bus_dev = to_nsim_bus_dev(dev);
-       struct nsim_dev *nsim_dev = dev_get_drvdata(dev);
-       struct devlink *devlink;
        unsigned int port_index;
        int ret;
 
@@ -224,12 +218,10 @@ del_port_store(struct device *dev, struct device_attribute *attr,
        if (ret)
                return ret;
 
-       devlink = priv_to_devlink(nsim_dev);
+       if (!mutex_trylock(&nsim_bus_dev->nsim_bus_reload_lock))
+               return -EBUSY;
 
-       mutex_lock(&nsim_bus_dev->nsim_bus_reload_lock);
-       devlink_reload_disable(devlink);
        ret = nsim_dev_port_del(nsim_bus_dev, NSIM_DEV_PORT_TYPE_PF, port_index);
-       devlink_reload_enable(devlink);
        mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
        return ret ? ret : count;
 }

diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index d538a39d42255b1c7dbd7eeb220c86845d085272..ff5714209b864e176a598d7cb022aaccbc795eb1 100644 (file)
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -864,16 +864,23 @@ static int nsim_dev_reload_down(struct devlink *devlink, bool netns_change,
                                struct netlink_ext_ack *extack)
 {
        struct nsim_dev *nsim_dev = devlink_priv(devlink);
+       struct nsim_bus_dev *nsim_bus_dev;
+
+       nsim_bus_dev = nsim_dev->nsim_bus_dev;
+       if (!mutex_trylock(&nsim_bus_dev->nsim_bus_reload_lock))
+               return -EOPNOTSUPP;
 
        if (nsim_dev->dont_allow_reload) {
                /* For testing purposes, user set debugfs dont_allow_reload
                 * value to true. So forbid it.
                 */
                NL_SET_ERR_MSG_MOD(extack, "User forbid the reload for testing purposes");
+               mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
                return -EOPNOTSUPP;
        }
 
        nsim_dev_reload_destroy(nsim_dev);
+       mutex_unlock(&nsim_bus_dev->nsim_bus_reload_lock);
        return 0;
 }