dpll: change dpll_netdev_pin_handle_size() to assume DPLL_A_PIN_ID will be used

We plan to no longer hold RTNL in "ip link show", and use RCU instead.

Assume rtnl_fill_dpll_pin() will have to fill DPLL_A_PIN_ID.

It is fine to over-estimate skb size (by 8 bytes) in if_nlmsg_size().

Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://patch.msgid.link/20260521171440.114956-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/dpll/dpll_netlink.c b/drivers/dpll/dpll_netlink.c
index 53ca24d0f191bc3268340543769fd96c836f9318..095ef8703c0b2687178a46c5312319376d518f79 100644 (file)
--- a/drivers/dpll/dpll_netlink.c
+++ b/drivers/dpll/dpll_netlink.c
@@ -89,17 +89,6 @@ static struct dpll_pin *dpll_netdev_pin(const struct net_device *dev)
        return rcu_dereference_rtnl(dev->dpll_pin);
 }
 
-/**
- * dpll_netdev_pin_handle_size - get size of pin handle attribute of a netdev
- * @dev: netdev from which to get the pin
- *
- * Return: byte size of pin handle attribute, or 0 if @dev has no pin.
- */
-size_t dpll_netdev_pin_handle_size(const struct net_device *dev)
-{
-       return dpll_netdev_pin(dev) ? nla_total_size(4) : 0; /* DPLL_A_PIN_ID */
-}
-
 int dpll_netdev_add_pin_handle(struct sk_buff *msg,
                               const struct net_device *dev)
 {

diff --git a/include/linux/dpll.h b/include/linux/dpll.h
index 82dfadd9f593b780c11d1d05cd00b62a32d4f534..4071fd974dd714eca92cae70e40bcde5a87a4706 100644 (file)
--- a/include/linux/dpll.h
+++ b/include/linux/dpll.h
@@ -13,6 +13,7 @@
 #include <linux/netdevice.h>
 #include <linux/notifier.h>
 #include <linux/rtnetlink.h>
+#include <net/netlink.h>
 
 struct dpll_device;
 struct dpll_pin;
@@ -238,7 +239,11 @@ struct dpll_pin_notifier_info {
 void dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin);
 void dpll_netdev_pin_clear(struct net_device *dev);
 
-size_t dpll_netdev_pin_handle_size(const struct net_device *dev);
+static inline size_t dpll_netdev_pin_handle_size(void)
+{
+       return nla_total_size(4); /* DPLL_A_PIN_ID */
+}
+
 int dpll_netdev_add_pin_handle(struct sk_buff *msg,
                               const struct net_device *dev);
 
@@ -249,7 +254,7 @@ static inline void
 dpll_netdev_pin_set(struct net_device *dev, struct dpll_pin *dpll_pin) { }
 static inline void dpll_netdev_pin_clear(struct net_device *dev) { }
 
-static inline size_t dpll_netdev_pin_handle_size(const struct net_device *dev)
+static inline size_t dpll_netdev_pin_handle_size(void)
 {
        return 0;
 }

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 5e461c752df122e1afed8fdc82206a8d7e8f90c7..0aa429336ffe1015390be634fc4bacbbb9842a50 100644 (file)
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -1263,11 +1263,11 @@ static size_t rtnl_devlink_port_size(const struct net_device *dev)
        return size;
 }
 
-static size_t rtnl_dpll_pin_size(const struct net_device *dev)
+static size_t rtnl_dpll_pin_size(void)
 {
        size_t size = nla_total_size(0); /* nest IFLA_DPLL_PIN */
 
-       size += dpll_netdev_pin_handle_size(dev);
+       size += dpll_netdev_pin_handle_size();
 
        return size;
 }
@@ -1348,7 +1348,7 @@ static noinline size_t if_nlmsg_size(const struct net_device *dev,
               + nla_total_size(4)  /* IFLA_MAX_MTU */
               + nla_total_size(MAX_ADDR_LEN) /* IFLA_PERM_ADDRESS */
               + rtnl_devlink_port_size(dev)
-              + rtnl_dpll_pin_size(dev)
+              + rtnl_dpll_pin_size()
               + nla_total_size(8)  /* IFLA_MAX_PACING_OFFLOAD_HORIZON */
               + nla_total_size(2)  /* IFLA_HEADROOM */
               + nla_total_size(2)  /* IFLA_TAILROOM */