Commit 097f171f authored by Jakub Kicinski's avatar Jakub Kicinski
Browse files

net: convert dev->rtnl_link_state to a bool 



netdevice reg_state was split into two 16 bit enums back in 2010
in commit a2835763 ("rtnetlink: handle rtnl_link netlink
notifications manually"). Since the split the fields have been
moved apart, and last year we converted reg_state to a normal
u8 in commit 4d42b37d ("net: convert dev->reg_state to u8").

rtnl_link_state being a 16 bitfield makes no sense. Convert it
to a single bool, it seems very unlikely after 15 years that
we'll need more values in it.

We could drop dev->rtnl_link_ops from the conditions but feels
like having it there more clearly points at the reason for this
hack.

Acked-by: default avatarStanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250410014246.780885-1-kuba@kernel.org


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent c26c192c

Documentation/networking/net_cachelines/net_device.rst

+1 −1
Original line number Diff line number Diff line
@@ -131,7 +131,7 @@ struct ref_tracker_dir refcnt_tracker 
struct list_head                    link_watch_list

enum:8                              reg_state

bool                                dismantle

enum:16                             rtnl_link_state

bool                                rtnl_link_initilizing

bool                                needs_free_netdev

void*priv_destructor                struct net_device

struct netpoll_info*                npinfo                                          read_mostly         napi_poll/napi_poll_lock

include/linux/netdevice.h

+2 −8
Original line number Diff line number Diff line
@@ -1946,9 +1946,6 @@ enum netdev_reg_state { 
 *

 *	@reg_state:		Register/unregister state machine

 *	@dismantle:		Device is going to be freed

 *	@rtnl_link_state:	This enum represents the phases of creating

 *				a new link

 *

 *	@needs_free_netdev:	Should unregister perform free_netdev?

 *	@priv_destructor:	Called from unregister

 *	@npinfo:		XXX: need comments on this one
@@ -2363,11 +2360,8 @@ struct net_device { 


	/** @moving_ns: device is changing netns, protected by @lock */

	bool moving_ns;



	enum {

		RTNL_LINK_INITIALIZED,

		RTNL_LINK_INITIALIZING,

	} rtnl_link_state:16;

	/** @rtnl_link_initializing: Device being created, suppress events */

	bool rtnl_link_initializing;



	bool needs_free_netdev;

	void (*priv_destructor)(struct net_device *dev);

net/core/dev.c

+2 −4
Original line number Diff line number Diff line
@@ -11110,8 +11110,7 @@ int register_netdevice(struct net_device *dev) 
	 *	Prevent userspace races by waiting until the network

	 *	device is fully setup before sending notifications.

	 */

	if (!dev->rtnl_link_ops ||

	    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)

	if (!(dev->rtnl_link_ops && dev->rtnl_link_initializing))

		rtmsg_ifinfo(RTM_NEWLINK, dev, ~0U, GFP_KERNEL, 0, NULL);



out:
@@ -12025,8 +12024,7 @@ void unregister_netdevice_many_notify(struct list_head *head, 
		 */

		call_netdevice_notifiers(NETDEV_UNREGISTER, dev);



		if (!dev->rtnl_link_ops ||

		    dev->rtnl_link_state == RTNL_LINK_INITIALIZED)

		if (!(dev->rtnl_link_ops && dev->rtnl_link_initializing))

			skb = rtmsg_ifinfo_build_skb(RTM_DELLINK, dev, ~0U, 0,

						     GFP_KERNEL, NULL, 0,

						     portid, nlh);

net/core/rtnetlink.c

+8 −7
Original line number Diff line number Diff line
@@ -3580,7 +3580,7 @@ static int rtnl_dellink(struct sk_buff *skb, struct nlmsghdr *nlh, 
int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm,

			u32 portid, const struct nlmsghdr *nlh)

{

	unsigned int old_flags;

	unsigned int old_flags, changed;

	int err;



	old_flags = dev->flags;
@@ -3591,12 +3591,13 @@ int rtnl_configure_link(struct net_device *dev, const struct ifinfomsg *ifm, 
			return err;

	}



	if (dev->rtnl_link_state == RTNL_LINK_INITIALIZED) {

		__dev_notify_flags(dev, old_flags, (old_flags ^ dev->flags), portid, nlh);

	} else {

		dev->rtnl_link_state = RTNL_LINK_INITIALIZED;

		__dev_notify_flags(dev, old_flags, ~0U, portid, nlh);

	changed = old_flags ^ dev->flags;

	if (dev->rtnl_link_initializing) {

		dev->rtnl_link_initializing = false;

		changed = ~0U;

	}



	__dev_notify_flags(dev, old_flags, changed, portid, nlh);

	return 0;

}

EXPORT_SYMBOL(rtnl_configure_link);
@@ -3654,7 +3655,7 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname, 


	dev_net_set(dev, net);

	dev->rtnl_link_ops = ops;

	dev->rtnl_link_state = RTNL_LINK_INITIALIZING;

	dev->rtnl_link_initializing = true;



	if (tb[IFLA_MTU]) {

		u32 mtu = nla_get_u32(tb[IFLA_MTU]);