| Message ID | 20210302122423.872326-1-martin@strongswan.org (mailing list archive) |
|---|---|
| State | Awaiting Upstream |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net] can: dev: Move device back to init netns on owning netns delete | expand |
On 3/2/21 1:24 PM, Martin Willi wrote: > When a non-initial netns is destroyed, the usual policy is to delete > all virtual network interfaces contained, but move physical interfaces > back to the initial netns. This keeps the physical interface visible > on the system. > > CAN devices are somewhat special, as they define rtnl_link_ops even > if they are physical devices. If a CAN interface is moved into a > non-initial netns, destroying that netns lets the interface vanish > instead of moving it back to the initial netns. default_device_exit() > skips CAN interfaces due to having rtnl_link_ops set. Reproducer: > > ip netns add foo > ip link set can0 netns foo > ip netns delete foo > > WARNING: CPU: 1 PID: 84 at net/core/dev.c:11030 ops_exit_list+0x38/0x60 > CPU: 1 PID: 84 Comm: kworker/u4:2 Not tainted 5.10.19 #1 > Workqueue: netns cleanup_net > [<c010e700>] (unwind_backtrace) from [<c010a1d8>] (show_stack+0x10/0x14) > [<c010a1d8>] (show_stack) from [<c086dc10>] (dump_stack+0x94/0xa8) > [<c086dc10>] (dump_stack) from [<c086b938>] (__warn+0xb8/0x114) > [<c086b938>] (__warn) from [<c086ba10>] (warn_slowpath_fmt+0x7c/0xac) > [<c086ba10>] (warn_slowpath_fmt) from [<c0629f20>] (ops_exit_list+0x38/0x60) > [<c0629f20>] (ops_exit_list) from [<c062a5c4>] (cleanup_net+0x230/0x380) > [<c062a5c4>] (cleanup_net) from [<c0142c20>] (process_one_work+0x1d8/0x438) > [<c0142c20>] (process_one_work) from [<c0142ee4>] (worker_thread+0x64/0x5a8) > [<c0142ee4>] (worker_thread) from [<c0148a98>] (kthread+0x148/0x14c) > [<c0148a98>] (kthread) from [<c0100148>] (ret_from_fork+0x14/0x2c) > > To properly restore physical CAN devices to the initial netns on owning > netns exit, introduce a flag on rtnl_link_ops that can be set by drivers. > For CAN devices setting this flag, default_device_exit() considers them > non-virtual, applying the usual namespace move. > > The issue was introduced in the commit mentioned below, as at that time > CAN devices did not have a dellink() operation. > > Fixes: e008b5fc8dc7 ("net: Simplfy default_device_exit and improve batching.") > Signed-off-by: Martin Willi <martin@strongswan.org> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> David, Jakub are you taking this patch? regards, Marc
From: Marc Kleine-Budde <mkl@pengutronix.de> Date: Wed, 3 Mar 2021 21:29:39 +0100 > Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> > > David, Jakub are you taking this patch? Nope, please take via the can tree, thanks!
On 03.03.2021 13:12:31, David Miller wrote: > From: Marc Kleine-Budde <mkl@pengutronix.de> > Date: Wed, 3 Mar 2021 21:29:39 +0100 > > > Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> > > > > David, Jakub are you taking this patch? > > Nope, please take via the can tree, thanks! Will do. Thanks, Marc
On 02.03.2021 13:24:23, Martin Willi wrote: > When a non-initial netns is destroyed, the usual policy is to delete > all virtual network interfaces contained, but move physical interfaces > back to the initial netns. This keeps the physical interface visible > on the system. > > CAN devices are somewhat special, as they define rtnl_link_ops even > if they are physical devices. If a CAN interface is moved into a > non-initial netns, destroying that netns lets the interface vanish > instead of moving it back to the initial netns. default_device_exit() > skips CAN interfaces due to having rtnl_link_ops set. Reproducer: > > ip netns add foo > ip link set can0 netns foo > ip netns delete foo > > WARNING: CPU: 1 PID: 84 at net/core/dev.c:11030 ops_exit_list+0x38/0x60 > CPU: 1 PID: 84 Comm: kworker/u4:2 Not tainted 5.10.19 #1 > Workqueue: netns cleanup_net > [<c010e700>] (unwind_backtrace) from [<c010a1d8>] (show_stack+0x10/0x14) > [<c010a1d8>] (show_stack) from [<c086dc10>] (dump_stack+0x94/0xa8) > [<c086dc10>] (dump_stack) from [<c086b938>] (__warn+0xb8/0x114) > [<c086b938>] (__warn) from [<c086ba10>] (warn_slowpath_fmt+0x7c/0xac) > [<c086ba10>] (warn_slowpath_fmt) from [<c0629f20>] (ops_exit_list+0x38/0x60) > [<c0629f20>] (ops_exit_list) from [<c062a5c4>] (cleanup_net+0x230/0x380) > [<c062a5c4>] (cleanup_net) from [<c0142c20>] (process_one_work+0x1d8/0x438) > [<c0142c20>] (process_one_work) from [<c0142ee4>] (worker_thread+0x64/0x5a8) > [<c0142ee4>] (worker_thread) from [<c0148a98>] (kthread+0x148/0x14c) > [<c0148a98>] (kthread) from [<c0100148>] (ret_from_fork+0x14/0x2c) > > To properly restore physical CAN devices to the initial netns on owning > netns exit, introduce a flag on rtnl_link_ops that can be set by drivers. > For CAN devices setting this flag, default_device_exit() considers them > non-virtual, applying the usual namespace move. > > The issue was introduced in the commit mentioned below, as at that time > CAN devices did not have a dellink() operation. > > Fixes: e008b5fc8dc7 ("net: Simplfy default_device_exit and improve batching.") > Signed-off-by: Martin Willi <martin@strongswan.org> applied to linux-can/testing Thanks, Marc
diff --git a/drivers/net/can/dev/netlink.c b/drivers/net/can/dev/netlink.c index 867f6be31230..f5d79e6e5483 100644 --- a/drivers/net/can/dev/netlink.c +++ b/drivers/net/can/dev/netlink.c @@ -355,6 +355,7 @@ static void can_dellink(struct net_device *dev, struct list_head *head) struct rtnl_link_ops can_link_ops __read_mostly = { .kind = "can", + .netns_refund = true, .maxtype = IFLA_CAN_MAX, .policy = can_policy, .setup = can_setup, diff --git a/include/net/rtnetlink.h b/include/net/rtnetlink.h index e2091bb2b3a8..4da61c950e93 100644 --- a/include/net/rtnetlink.h +++ b/include/net/rtnetlink.h @@ -33,6 +33,7 @@ static inline int rtnl_msg_family(const struct nlmsghdr *nlh) * * @list: Used internally * @kind: Identifier + * @netns_refund: Physical device, move to init_net on netns exit * @maxtype: Highest device specific netlink attribute number * @policy: Netlink policy for device specific attribute validation * @validate: Optional validation function for netlink/changelink parameters @@ -64,6 +65,7 @@ struct rtnl_link_ops { size_t priv_size; void (*setup)(struct net_device *dev); + bool netns_refund; unsigned int maxtype; const struct nla_policy *policy; int (*validate)(struct nlattr *tb[], diff --git a/net/core/dev.c b/net/core/dev.c index 6c5967e80132..a142a207fc1d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -11346,7 +11346,7 @@ static void __net_exit default_device_exit(struct net *net) continue; /* Leave virtual devices for the generic cleanup */ - if (dev->rtnl_link_ops) + if (dev->rtnl_link_ops && !dev->rtnl_link_ops->netns_refund) continue; /* Push remaining network devices to init_net */
When a non-initial netns is destroyed, the usual policy is to delete all virtual network interfaces contained, but move physical interfaces back to the initial netns. This keeps the physical interface visible on the system. CAN devices are somewhat special, as they define rtnl_link_ops even if they are physical devices. If a CAN interface is moved into a non-initial netns, destroying that netns lets the interface vanish instead of moving it back to the initial netns. default_device_exit() skips CAN interfaces due to having rtnl_link_ops set. Reproducer: ip netns add foo ip link set can0 netns foo ip netns delete foo WARNING: CPU: 1 PID: 84 at net/core/dev.c:11030 ops_exit_list+0x38/0x60 CPU: 1 PID: 84 Comm: kworker/u4:2 Not tainted 5.10.19 #1 Workqueue: netns cleanup_net [<c010e700>] (unwind_backtrace) from [<c010a1d8>] (show_stack+0x10/0x14) [<c010a1d8>] (show_stack) from [<c086dc10>] (dump_stack+0x94/0xa8) [<c086dc10>] (dump_stack) from [<c086b938>] (__warn+0xb8/0x114) [<c086b938>] (__warn) from [<c086ba10>] (warn_slowpath_fmt+0x7c/0xac) [<c086ba10>] (warn_slowpath_fmt) from [<c0629f20>] (ops_exit_list+0x38/0x60) [<c0629f20>] (ops_exit_list) from [<c062a5c4>] (cleanup_net+0x230/0x380) [<c062a5c4>] (cleanup_net) from [<c0142c20>] (process_one_work+0x1d8/0x438) [<c0142c20>] (process_one_work) from [<c0142ee4>] (worker_thread+0x64/0x5a8) [<c0142ee4>] (worker_thread) from [<c0148a98>] (kthread+0x148/0x14c) [<c0148a98>] (kthread) from [<c0100148>] (ret_from_fork+0x14/0x2c) To properly restore physical CAN devices to the initial netns on owning netns exit, introduce a flag on rtnl_link_ops that can be set by drivers. For CAN devices setting this flag, default_device_exit() considers them non-virtual, applying the usual namespace move. The issue was introduced in the commit mentioned below, as at that time CAN devices did not have a dellink() operation. Fixes: e008b5fc8dc7 ("net: Simplfy default_device_exit and improve batching.") Signed-off-by: Martin Willi <martin@strongswan.org> --- drivers/net/can/dev/netlink.c | 1 + include/net/rtnetlink.h | 2 ++ net/core/dev.c | 2 +- 3 files changed, 4 insertions(+), 1 deletion(-)