From: Jakub Kicinski <kuba@kernel•org>
To: davem@davemloft•net
Cc: netdev@vger•kernel.org, jiri@resnulli•us, leon@kernel•org,
mkubecek@suse•cz, andrew@lunn•ch, f.fainelli@gmail•com,
Jakub Kicinski <kuba@kernel•org>
Subject: [PATCH net-next 3/4] devlink: expose get/put functions
Date: Fri, 29 Oct 2021 21:06:10 -0700 [thread overview]
Message-ID: <20211030040611.1751638-4-kuba@kernel.org> (raw)
In-Reply-To: <20211030040611.1751638-1-kuba@kernel.org>
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: Jakub Kicinski <kuba@kernel•org>
---
include/net/devlink.h | 12 ++++++++++++
net/core/devlink.c | 8 +++++---
2 files changed, 17 insertions(+), 3 deletions(-)
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 1b1317d378de..991ce48f77ca 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -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)
{
diff --git a/net/core/devlink.c b/net/core/devlink.c
index 2d8abe88c673..100d87fd3f65 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -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,
--
2.31.1
next prev parent reply other threads:[~2021-10-30 4:06 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-10-30 4:06 [PATCH net-next 0/4] improve ethtool/rtnl vs devlink locking Jakub Kicinski
2021-10-30 4:06 ` [PATCH net-next 1/4] ethtool: push the rtnl_lock into dev_ethtool() Jakub Kicinski
2021-10-30 4:06 ` [PATCH net-next 2/4] ethtool: handle info/flash data copying outside rtnl_lock Jakub Kicinski
2021-10-30 4:06 ` Jakub Kicinski [this message]
2021-10-30 4:06 ` [PATCH net-next 4/4] ethtool: don't drop the rtnl_lock half way thru the ioctl Jakub Kicinski
2021-10-30 8:50 ` kernel test robot
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