Commit 46db1b77 authored by Jakub Kicinski's avatar Jakub Kicinski Committed by David S. Miller
Browse files

devlink: expose get/put functions 



Allow those who hold implicit reference on a devlink instance
to try to take a full ref on it. This will be used from netdev
code which has an implicit ref because of driver call ordering.

Note that after recent changes devlink_unregister() may happen
before netdev unregister, but devlink_free() should still happen
after, so we are safe to try, but we can't just refcount_inc()
and assume it's not zero.

Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Reviewed-by: default avatarLeon Romanovsky <leonro@nvidia.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 095cfcfe

include/net/devlink.h

+12 −0
Original line number Diff line number Diff line
@@ -1726,6 +1726,9 @@ devlink_trap_policers_unregister(struct devlink *devlink, 


#if IS_ENABLED(CONFIG_NET_DEVLINK)



struct devlink *__must_check devlink_try_get(struct devlink *devlink);

void devlink_put(struct devlink *devlink);



void devlink_compat_running_version(struct net_device *dev,

				    char *buf, size_t len);

int devlink_compat_flash_update(struct net_device *dev, const char *file_name);
@@ -1736,6 +1739,15 @@ int devlink_compat_switch_id_get(struct net_device *dev, 


#else



static inline struct devlink *devlink_try_get(struct devlink *devlink)

{

	return NULL;

}



static inline void devlink_put(struct devlink *devlink)

{

}



static inline void

devlink_compat_running_version(struct net_device *dev, char *buf, size_t len)

{

net/core/devlink.c

+5 −3
Original line number Diff line number Diff line
@@ -182,15 +182,17 @@ struct net *devlink_net(const struct devlink *devlink) 
}

EXPORT_SYMBOL_GPL(devlink_net);



static void devlink_put(struct devlink *devlink)

void devlink_put(struct devlink *devlink)

{

	if (refcount_dec_and_test(&devlink->refcount))

		complete(&devlink->comp);

}



static bool __must_check devlink_try_get(struct devlink *devlink)

struct devlink *__must_check devlink_try_get(struct devlink *devlink)

{

	return refcount_inc_not_zero(&devlink->refcount);

	if (refcount_inc_not_zero(&devlink->refcount))

		return devlink;

	return NULL;

}



static struct devlink *devlink_get_from_attrs(struct net *net,