Re: [PATCH net-next V6 07/14] devlink: Add parent dev to devlink API

[Simon Horman <horms@kernel.org>]

On Sun, Jan 25, 2026 at 01:31:56PM +0200, Tariq Toukan wrote:
> From: Cosmin Ratiu <cratiu@nvidia.com>
> 
> Upcoming changes to the rate commands need the parent devlink specified.
> This change adds a nested 'parent-dev' attribute to the API and helpers
> to obtain and put a reference to the parent devlink instance in
> info->user_ptr[1].
> 
> To avoid deadlocks, the parent devlink is unlocked before obtaining the
> main devlink instance that is the target of the request.
> A reference to the parent is kept until the end of the request to avoid
> it suddenly disappearing.
> 
> This means that this reference is of limited use without additional
> protection.
> 
> Signed-off-by: Cosmin Ratiu <cratiu@nvidia.com>
> Reviewed-by: Carolina Jubran <cjubran@nvidia.com>
> Reviewed-by: Jiri Pirko <jiri@nvidia.com>
> Signed-off-by: Tariq Toukan <tariqt@nvidia.com>

...

Hi Cosmin, all,

The netlink_gen.[ch] and spec changes in this patch do not seem consistent.

$ tools/net/ynl/ynl-regen.sh -f
$ git diff
diff --git a/net/devlink/netlink_gen.c b/net/devlink/netlink_gen.c
index 6b691bdbf037..f4c61c2b4f22 100644
--- a/net/devlink/netlink_gen.c
+++ b/net/devlink/netlink_gen.c
@@ -39,11 +39,6 @@ devlink_attr_param_type_validate(const struct nlattr *attr,
 }

 /* Common nested types */
-const struct nla_policy devlink_dl_parent_dev_nl_policy[DEVLINK_ATTR_DEV_NAME + 1] = {
-       [DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING, },
-       [DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING, },
-};
-
 const struct nla_policy devlink_dl_port_function_nl_policy[DEVLINK_PORT_FN_ATTR_CAPS + 1] = {
        [DEVLINK_PORT_FUNCTION_ATTR_HW_ADDR] = { .type = NLA_BINARY, },
        [DEVLINK_PORT_FN_ATTR_STATE] = NLA_POLICY_MAX(NLA_U8, 1),
diff --git a/net/devlink/netlink_gen.h b/net/devlink/netlink_gen.h
index d4db82a00522..2817d53a0eba 100644
--- a/net/devlink/netlink_gen.h
+++ b/net/devlink/netlink_gen.h
@@ -13,7 +13,6 @@
 #include <uapi/linux/devlink.h>

 /* Common nested types */
-extern const struct nla_policy devlink_dl_parent_dev_nl_policy[DEVLINK_ATTR_DEV_NAME + 1];
 extern const struct nla_policy devlink_dl_port_function_nl_policy[DEVLINK_PORT_FN_ATTR_CAPS + 1];
 extern const struct nla_policy devlink_dl_rate_tc_bws_nl_policy[DEVLINK_RATE_TC_ATTR_BW + 1];
 extern const struct nla_policy devlink_dl_selftest_id_nl_policy[DEVLINK_ATTR_SELFTEST_ID_FLASH + 1];
@@ -30,19 +29,12 @@ int devlink_nl_pre_doit_dev_lock(const struct genl_split_ops *ops,
 int devlink_nl_pre_doit_port_optional(const struct genl_split_ops *ops,
                                      struct sk_buff *skb,
                                      struct genl_info *info);
-int devlink_nl_pre_doit_parent_dev_optional(const struct genl_split_ops *ops,
-                                           struct sk_buff *skb,
-                                           struct genl_info *info);
 void
 devlink_nl_post_doit(const struct genl_split_ops *ops, struct sk_buff *skb,
                     struct genl_info *info);
 void
 devlink_nl_post_doit_dev_lock(const struct genl_split_ops *ops,
                              struct sk_buff *skb, struct genl_info *info);
-void
-devlink_nl_post_doit_parent_dev_optional(const struct genl_split_ops *ops,
-                                        struct sk_buff *skb,
-                                        struct genl_info *info);

 int devlink_nl_get_doit(struct sk_buff *skb, struct genl_info *info);
 int devlink_nl_get_dumpit(struct sk_buff *skb, struct netlink_callback *cb);
;