Re: [PATCH net-next RFC v4 02/15] devlink: Add reload action limit level

Jiri Pirko
2020-09-14T13:19:55Z

Mon, Sep 14, 2020 at 08:07:49AM CEST, moshe@mellanox.com wrote:

[..]

>diff --git a/include/net/devlink.h b/include/net/devlink.h
>index b09db891db04..dddd9ee5b8a9 100644
>--- a/include/net/devlink.h
>+++ b/include/net/devlink.h
>@@ -1012,9 +1012,13 @@ enum devlink_trap_group_generic_id {
>
> struct devlink_ops {
> unsigned long supported_reload_actions;
>+ unsigned long supported_reload_action_limit_levels;
> int (*reload_down)(struct devlink *devlink, bool netns_change,
>- enum devlink_reload_action action, struct netlink_ext_ack *extack);
>+ enum devlink_reload_action action,
>+ enum devlink_reload_action_limit_level limit_level,
>+ struct netlink_ext_ack *extack);
> int (*reload_up)(struct devlink *devlink, enum devlink_reload_action action,
>+ enum devlink_reload_action_limit_level limit_level,
> struct netlink_ext_ack *extack, unsigned long *actions_performed);
> int (*port_type_set)(struct devlink_port *devlink_port,
> enum devlink_port_type port_type);
>diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
>index a6f64db0bdf3..b19686fd80ff 100644
>--- a/include/uapi/linux/devlink.h
>+++ b/include/uapi/linux/devlink.h
>@@ -287,6 +287,22 @@ enum devlink_reload_action {
> DEVLINK_RELOAD_ACTION_MAX = __DEVLINK_RELOAD_ACTION_MAX - 1
> };
>
>+/**
>+ * enum devlink_reload_action_limit_level - Reload action limit level.
>+ * @DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE: No constrains on action. Action may include
>+ * reset or downtime as needed.
>+ * @DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NO_RESET: No reset allowed, no down time allowed,
>+ * no link flap and no configuration is lost.
>+ */
>+enum devlink_reload_action_limit_level {
>+ DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE,
>+ DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NO_RESET,
>+
>+ /* Add new reload actions limit level above */
>+ __DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX,
>+ DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX = __DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX - 1
>+};
>+
> enum devlink_attr {
> /* don't change the order or add anything between, this is ABI! */
> DEVLINK_ATTR_UNSPEC,
>@@ -478,6 +494,7 @@ enum devlink_attr {
>
> DEVLINK_ATTR_RELOAD_ACTION, /* u8 */
> DEVLINK_ATTR_RELOAD_ACTIONS_PERFORMED, /* nested */
>+ DEVLINK_ATTR_RELOAD_ACTION_LIMIT_LEVEL, /* u8 */
>
> /* add new attributes above here, update the policy in devlink.c */
>
>diff --git a/net/core/devlink.c b/net/core/devlink.c
>index f4be1e1bf864..60aa0c4a3726 100644
>--- a/net/core/devlink.c
>+++ b/net/core/devlink.c
>@@ -468,6 +468,13 @@ devlink_reload_action_is_supported(struct devlink *devlink, enum devlink_reload_
> return test_bit(action, &devlink->ops->supported_reload_actions);
> }
>
>+static bool
>+devlink_reload_action_limit_level_is_supported(struct devlink *devlink,
>+ enum devlink_reload_action_limit_level limit_level)
>+{
>+ return test_bit(limit_level, &devlink->ops->supported_reload_action_limit_levels);
>+}
>+
> static int devlink_nl_fill(struct sk_buff *msg, struct devlink *devlink,
> enum devlink_command cmd, u32 portid,
> u32 seq, int flags)
>@@ -2975,22 +2982,23 @@ 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,
>- enum devlink_reload_action action, struct netlink_ext_ack *extack,
>- unsigned long *actions_performed)
>+ enum devlink_reload_action action,
>+ enum devlink_reload_action_limit_level limit_level,
>+ struct netlink_ext_ack *extack, unsigned long *actions_performed)
> {
> int err;
>
> if (!devlink->reload_enabled)
> return -EOPNOTSUPP;
>
>- err = devlink->ops->reload_down(devlink, !!dest_net, action, extack);
>+ err = devlink->ops->reload_down(devlink, !!dest_net, action, limit_level, 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, action, extack, actions_performed);
>+ err = devlink->ops->reload_up(devlink, action, limit_level, extack, actions_performed);
> devlink_reload_failed_set(devlink, !!err);
> return err;
> }
>@@ -3036,6 +3044,7 @@ devlink_nl_reload_actions_performed_fill(struct sk_buff *msg,
>
> static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
> {
>+ enum devlink_reload_action_limit_level limit_level;
> struct devlink *devlink = info->user_ptr[0];
> enum devlink_reload_action action;
> unsigned long actions_performed;
>@@ -3073,7 +3082,20 @@ static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info)
> return -EOPNOTSUPP;
> }
>
>- err = devlink_reload(devlink, dest_net, action, info->extack, &actions_performed);
>+ if (info->attrs[DEVLINK_ATTR_RELOAD_ACTION_LIMIT_LEVEL])
>+ limit_level = nla_get_u8(info->attrs[DEVLINK_ATTR_RELOAD_ACTION_LIMIT_LEVEL]);
>+ else
>+ limit_level = DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE;
>+
>+ if (limit_level > DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX) {

Again, not needed, devlink_reload_action_limit_level_is_supported() will
take case of it.

>+ NL_SET_ERR_MSG_MOD(info->extack, "Invalid limit level");
>+ return -EINVAL;
>+ } else if (!devlink_reload_action_limit_level_is_supported(devlink, limit_level)) {
>+ NL_SET_ERR_MSG_MOD(info->extack, "Requested limit level is not supported");

"..by the driver"?

>+ return -EOPNOTSUPP;
>+ }
>+ err = devlink_reload(devlink, dest_net, action, limit_level, info->extack,
>+ &actions_performed);
>
> if (dest_net)
> put_net(dest_net);
>@@ -7126,6 +7148,7 @@ static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
> [DEVLINK_ATTR_TRAP_POLICER_BURST] = { .type = NLA_U64 },
> [DEVLINK_ATTR_PORT_FUNCTION] = { .type = NLA_NESTED },
> [DEVLINK_ATTR_RELOAD_ACTION] = { .type = NLA_U8 },
>+ [DEVLINK_ATTR_RELOAD_ACTION_LIMIT_LEVEL] = { .type = NLA_U8 },
> };
>
> static const struct genl_ops devlink_nl_ops[] = {
>@@ -7462,6 +7485,10 @@ static int devlink_reload_actions_verify(struct devlink *devlink)
> if (WARN_ON(ops->supported_reload_actions >= BIT(__DEVLINK_RELOAD_ACTION_MAX) ||
> ops->supported_reload_actions <= BIT(DEVLINK_RELOAD_ACTION_UNSPEC)))
> return -EINVAL;
>+ if (WARN_ON(!ops->supported_reload_action_limit_levels ||
>+ ops->supported_reload_action_limit_levels >=
>+ BIT(__DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_MAX)))
>+ return -EINVAL;

I think that you can check some insane driver combinations like:
supports only driver-reinit, supports LEVEL_NO_RESET - that is
impossible and should be refused here.

Same goes to the actual user command call. If the user calls for
driver-reinit with LEVEL_NO_RESET, devlink should refuse with proper
extack

> return 0;
> }
>
>@@ -9756,7 +9783,8 @@ static void __net_exit devlink_pernet_pre_exit(struct net *net)
> if (WARN_ON(!devlink_reload_supported(devlink)))
> continue;
> err = devlink_reload(devlink, &init_net,
>- DEVLINK_RELOAD_ACTION_DRIVER_REINIT, NULL, NULL);
>+ DEVLINK_RELOAD_ACTION_DRIVER_REINIT,
>+ DEVLINK_RELOAD_ACTION_LIMIT_LEVEL_NONE, NULL, NULL);
> if (err && err != -EOPNOTSUPP)
> pr_warn("Failed to reload devlink instance into init_net\n");
> }
>--
>2.17.1
>