net: devlink: allow to change namespaces during reload

All devlink instances are created in init_net and stay there for a
lifetime. Allow user to be able to move devlink instances into
namespaces during devlink reload operation. That ensures proper
re-instantiation of driver objects, including netdevices.

Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/mellanox/mlx4/main.c b/drivers/net/ethernet/mellanox/mlx4/main.c
index fce9b3a..22c72fb 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx4/main.c
+++ b/drivers/net/ethernet/mellanox/mlx4/main.c
@@ -3935,13 +3935,17 @@ static void mlx4_restart_one_down(struct pci_dev *pdev);
 static int mlx4_restart_one_up(struct pci_dev *pdev, bool reload,
                               struct devlink *devlink);
 
-static int mlx4_devlink_reload_down(struct devlink *devlink,
+static int mlx4_devlink_reload_down(struct devlink *devlink, bool netns_change,
                                    struct netlink_ext_ack *extack)
 {
        struct mlx4_priv *priv = devlink_priv(devlink);
        struct mlx4_dev *dev = &priv->dev;
        struct mlx4_dev_persistent *persist = dev->persist;
 
+       if (netns_change) {
+               NL_SET_ERR_MSG_MOD(extack, "Namespace change is not supported");
+               return -EOPNOTSUPP;
+       }
        if (persist->num_vfs)
                mlx4_warn(persist->dev, "Reload performed on PF, will cause reset on operating Virtual Functions\n");
        mlx4_restart_one_down(persist->pdev);

diff --git a/drivers/net/ethernet/mellanox/mlxsw/core.c b/drivers/net/ethernet/mellanox/mlxsw/core.c
index 1e61a01..1c29522 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlxsw/core.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/core.c
@@ -985,6 +985,7 @@ mlxsw_devlink_info_get(struct devlink *devlink, struct devlink_info_req *req,
 
 static int
 mlxsw_devlink_core_bus_device_reload_down(struct devlink *devlink,
+                                         bool netns_change,
                                          struct netlink_ext_ack *extack)
 {
        struct mlxsw_core *mlxsw_core = devlink_priv(devlink);

diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
index 7de80fa..3f3c7cc 100644 (file)
--- a/drivers/net/netdevsim/dev.c
+++ b/drivers/net/netdevsim/dev.c
@@ -473,7 +473,7 @@ static int nsim_dev_reload_create(struct nsim_dev *nsim_dev,
                                  struct netlink_ext_ack *extack);
 static void nsim_dev_reload_destroy(struct nsim_dev *nsim_dev);
 
-static int nsim_dev_reload_down(struct devlink *devlink,
+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);

diff --git a/include/net/devlink.h b/include/net/devlink.h
index 5ac2be0..3c9d4a0 100644 (file)
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -643,7 +643,7 @@ enum devlink_trap_group_generic_id {
        }
 
 struct devlink_ops {
-       int (*reload_down)(struct devlink *devlink,
+       int (*reload_down)(struct devlink *devlink, bool netns_change,
                           struct netlink_ext_ack *extack);
        int (*reload_up)(struct devlink *devlink,
                         struct netlink_ext_ack *extack);

diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 580b7a2..b558ea8 100644 (file)
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -421,6 +421,10 @@ enum devlink_attr {
 
        DEVLINK_ATTR_RELOAD_FAILED,                     /* u8 0 or 1 */
 
+       DEVLINK_ATTR_NETNS_FD,                  /* u32 */
+       DEVLINK_ATTR_NETNS_PID,                 /* u32 */
+       DEVLINK_ATTR_NETNS_ID,                  /* u32 */
+
        /* add new attributes above here, update the policy in devlink.c */
 
        __DEVLINK_ATTR_MAX,

diff --git a/net/core/devlink.c b/net/core/devlink.c
index 362cbbc..c4d8c4a 100644 (file)
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -435,8 +435,16 @@ static void devlink_nl_post_doit(const struct genl_ops *ops,
 {
        struct devlink *devlink;
 
-       devlink = devlink_get_from_info(info);
-       if (~ops->internal_flags & DEVLINK_NL_FLAG_NO_LOCK)
+       /* When devlink changes netns, it would not be found
+        * by devlink_get_from_info(). So try if it is stored first.
+        */
+       if (ops->internal_flags & DEVLINK_NL_FLAG_NEED_DEVLINK) {
+               devlink = info->user_ptr[0];
+       } else {
+               devlink = devlink_get_from_info(info);
+               WARN_ON(IS_ERR(devlink));
+       }
+       if (!IS_ERR(devlink) && ~ops->internal_flags & DEVLINK_NL_FLAG_NO_LOCK)
                mutex_unlock(&devlink->lock);
        mutex_unlock(&devlink_mutex);
 }
@@ -2675,6 +2683,72 @@ devlink_resources_validate(struct devlink *devlink,
        return err;
 }
 
+static struct net *devlink_netns_get(struct sk_buff *skb,
+                                    struct genl_info *info)
+{
+       struct nlattr *netns_pid_attr = info->attrs[DEVLINK_ATTR_NETNS_PID];
+       struct nlattr *netns_fd_attr = info->attrs[DEVLINK_ATTR_NETNS_FD];
+       struct nlattr *netns_id_attr = info->attrs[DEVLINK_ATTR_NETNS_ID];
+       struct net *net;
+
+       if (!!netns_pid_attr + !!netns_fd_attr + !!netns_id_attr > 1) {
+               NL_SET_ERR_MSG(info->extack, "multiple netns identifying attributes specified");
+               return ERR_PTR(-EINVAL);
+       }
+
+       if (netns_pid_attr) {
+               net = get_net_ns_by_pid(nla_get_u32(netns_pid_attr));
+       } else if (netns_fd_attr) {
+               net = get_net_ns_by_fd(nla_get_u32(netns_fd_attr));
+       } else if (netns_id_attr) {
+               net = get_net_ns_by_id(sock_net(skb->sk),
+                                      nla_get_u32(netns_id_attr));
+               if (!net)
+                       net = ERR_PTR(-EINVAL);
+       } else {
+               WARN_ON(1);
+               net = ERR_PTR(-EINVAL);
+       }
+       if (IS_ERR(net)) {
+               NL_SET_ERR_MSG(info->extack, "Unknown network namespace");
+               return ERR_PTR(-EINVAL);
+       }
+       if (!netlink_ns_capable(skb, net->user_ns, CAP_NET_ADMIN)) {
+               put_net(net);
+               return ERR_PTR(-EPERM);
+       }
+       return net;
+}
+
+static void devlink_param_notify(struct devlink *devlink,
+                                unsigned int port_index,
+                                struct devlink_param_item *param_item,
+                                enum devlink_command cmd);
+
+static void devlink_reload_netns_change(struct devlink *devlink,
+                                       struct net *dest_net)
+{
+       struct devlink_param_item *param_item;
+
+       /* Userspace needs to be notified about devlink objects
+        * removed from original and entering new network namespace.
+        * The rest of the devlink objects are re-created during
+        * reload process so the notifications are generated separatelly.
+        */
+
+       list_for_each_entry(param_item, &devlink->param_list, list)
+               devlink_param_notify(devlink, 0, param_item,
+                                    DEVLINK_CMD_PARAM_DEL);
+       devlink_notify(devlink, DEVLINK_CMD_DEL);
+
+       devlink_net_set(devlink, dest_net);
+
+       devlink_notify(devlink, DEVLINK_CMD_NEW);
+       list_for_each_entry(param_item, &devlink->param_list, list)
+               devlink_param_notify(devlink, 0, param_item,
+                                    DEVLINK_CMD_PARAM_NEW);
+}
+
 static bool devlink_reload_supported(struct devlink *devlink)
 {
        return devlink->ops->reload_down && devlink->ops->reload_up;
@@ -2695,9 +2769,27 @@ bool devlink_is_reload_failed(const struct devlink *devlink)
 }
 EXPORT_SYMBOL_GPL(devlink_is_reload_failed);
 
+static int devlink_reload(struct devlink *devlink, struct net *dest_net,
+                         struct netlink_ext_ack *extack)
+{
+       int err;
+
+       err = devlink->ops->reload_down(devlink, !!dest_net, extack);
+       if (err)
+               return err;
+
+       if (dest_net && !net_eq(dest_net, devlink_net(devlink)))
+               devlink_reload_netns_change(devlink, dest_net);
+
+       err = devlink->ops->reload_up(devlink, extack);
+       devlink_reload_failed_set(devlink, !!err);
+       return err;
+}
+
 static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
 {
        struct devlink *devlink = info->user_ptr[0];
+       struct net *dest_net = NULL;
        int err;
 
        if (!devlink_reload_supported(devlink))
@@ -2708,11 +2800,20 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
                NL_SET_ERR_MSG_MOD(info->extack, "resources size validation failed");
                return err;
        }
-       err = devlink->ops->reload_down(devlink, info->extack);
-       if (err)
-               return err;
-       err = devlink->ops->reload_up(devlink, info->extack);
-       devlink_reload_failed_set(devlink, !!err);
+
+       if (info->attrs[DEVLINK_ATTR_NETNS_PID] ||
+           info->attrs[DEVLINK_ATTR_NETNS_FD] ||
+           info->attrs[DEVLINK_ATTR_NETNS_ID]) {
+               dest_net = devlink_netns_get(skb, info);
+               if (IS_ERR(dest_net))
+                       return PTR_ERR(dest_net);
+       }
+
+       err = devlink_reload(devlink, dest_net, info->extack);
+
+       if (dest_net)
+               put_net(dest_net);
+
        return err;
 }
 
@@ -5794,6 +5895,9 @@ static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
        [DEVLINK_ATTR_TRAP_NAME] = { .type = NLA_NUL_STRING },
        [DEVLINK_ATTR_TRAP_ACTION] = { .type = NLA_U8 },
        [DEVLINK_ATTR_TRAP_GROUP_NAME] = { .type = NLA_NUL_STRING },
+       [DEVLINK_ATTR_NETNS_PID] = { .type = NLA_U32 },
+       [DEVLINK_ATTR_NETNS_FD] = { .type = NLA_U32 },
+       [DEVLINK_ATTR_NETNS_ID] = { .type = NLA_U32 },
 };
 
 static const struct genl_ops devlink_nl_ops[] = {
@@ -8061,9 +8165,43 @@ int devlink_compat_switch_id_get(struct net_device *dev,
        return 0;
 }
 
+static void __net_exit devlink_pernet_pre_exit(struct net *net)
+{
+       struct devlink *devlink;
+       int err;
+
+       /* In case network namespace is getting destroyed, reload
+        * all devlink instances from this namespace into init_net.
+        */
+       mutex_lock(&devlink_mutex);
+       list_for_each_entry(devlink, &devlink_list, list) {
+               if (net_eq(devlink_net(devlink), net)) {
+                       if (WARN_ON(!devlink_reload_supported(devlink)))
+                               continue;
+                       err = devlink_reload(devlink, &init_net, NULL);
+                       if (err)
+                               pr_warn("Failed to reload devlink instance into init_net\n");
+               }
+       }
+       mutex_unlock(&devlink_mutex);
+}
+
+static struct pernet_operations devlink_pernet_ops __net_initdata = {
+       .pre_exit = devlink_pernet_pre_exit,
+};
+
 static int __init devlink_init(void)
 {
-       return genl_register_family(&devlink_nl_family);
+       int err;
+
+       err = genl_register_family(&devlink_nl_family);
+       if (err)
+               goto out;
+       err = register_pernet_subsys(&devlink_pernet_ops);
+
+out:
+       WARN_ON(err);
+       return err;
 }
 
 subsys_initcall(devlink_init);