From afa0df5998131153ec3036f41e76ece33bf1334f Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Mon, 30 Sep 2019 10:15:09 +0200 Subject: [PATCH 1/3] net: push loops and nb calls into helper functions Push iterations over net namespaces and netdevices from register_netdevice_notifier() and unregister_netdevice_notifier() into helper functions. Along with that introduce continue_reverse macros to make the code a bit nicer allowing to get rid of "last" marks. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- include/linux/netdevice.h | 3 ++ include/net/net_namespace.h | 3 +- net/core/dev.c | 89 +++++++++++++++++++++++++------------ 3 files changed, 66 insertions(+), 29 deletions(-) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 48cc71aae466f..7b183f724fc4f 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2574,6 +2574,9 @@ extern rwlock_t dev_base_lock; /* Device list lock */ list_for_each_entry_safe(d, n, &(net)->dev_base_head, dev_list) #define for_each_netdev_continue(net, d) \ list_for_each_entry_continue(d, &(net)->dev_base_head, dev_list) +#define for_each_netdev_continue_reverse(net, d) \ + list_for_each_entry_continue_reverse(d, &(net)->dev_base_head, \ + dev_list) #define for_each_netdev_continue_rcu(net, d) \ list_for_each_entry_continue_rcu(d, &(net)->dev_base_head, dev_list) #define for_each_netdev_in_bond_rcu(bond, slave) \ diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index f8712bbeb2e03..c5a98e03591df 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -317,7 +317,8 @@ static inline struct net *read_pnet(const possible_net_t *pnet) /* Protected by net_rwsem */ #define for_each_net(VAR) \ list_for_each_entry(VAR, &net_namespace_list, list) - +#define for_each_net_continue_reverse(VAR) \ + list_for_each_entry_continue_reverse(VAR, &net_namespace_list, list) #define for_each_net_rcu(VAR) \ list_for_each_entry_rcu(VAR, &net_namespace_list, list) diff --git a/net/core/dev.c b/net/core/dev.c index 7a456c6a7ad83..a8b70cb6c732a 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1725,6 +1725,62 @@ static int call_netdevice_notifier(struct notifier_block *nb, unsigned long val, return nb->notifier_call(nb, val, &info); } +static int call_netdevice_register_notifiers(struct notifier_block *nb, + struct net_device *dev) +{ + int err; + + err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev); + err = notifier_to_errno(err); + if (err) + return err; + + if (!(dev->flags & IFF_UP)) + return 0; + + call_netdevice_notifier(nb, NETDEV_UP, dev); + return 0; +} + +static void call_netdevice_unregister_notifiers(struct notifier_block *nb, + struct net_device *dev) +{ + if (dev->flags & IFF_UP) { + call_netdevice_notifier(nb, NETDEV_GOING_DOWN, + dev); + call_netdevice_notifier(nb, NETDEV_DOWN, dev); + } + call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev); +} + +static int call_netdevice_register_net_notifiers(struct notifier_block *nb, + struct net *net) +{ + struct net_device *dev; + int err; + + for_each_netdev(net, dev) { + err = call_netdevice_register_notifiers(nb, dev); + if (err) + goto rollback; + } + return 0; + +rollback: + for_each_netdev_continue_reverse(net, dev) + call_netdevice_unregister_notifiers(nb, dev); + return err; +} + +static void call_netdevice_unregister_net_notifiers(struct notifier_block *nb, + struct net *net) +{ + struct net_device *dev; + + for_each_netdev(net, dev) + call_netdevice_unregister_notifiers(nb, dev); +} + static int dev_boot_phase = 1; /** @@ -1743,8 +1799,6 @@ static int dev_boot_phase = 1; int register_netdevice_notifier(struct notifier_block *nb) { - struct net_device *dev; - struct net_device *last; struct net *net; int err; @@ -1757,17 +1811,9 @@ int register_netdevice_notifier(struct notifier_block *nb) if (dev_boot_phase) goto unlock; for_each_net(net) { - for_each_netdev(net, dev) { - err = call_netdevice_notifier(nb, NETDEV_REGISTER, dev); - err = notifier_to_errno(err); - if (err) - goto rollback; - - if (!(dev->flags & IFF_UP)) - continue; - - call_netdevice_notifier(nb, NETDEV_UP, dev); - } + err = call_netdevice_register_net_notifiers(nb, net); + if (err) + goto rollback; } unlock: @@ -1776,22 +1822,9 @@ int register_netdevice_notifier(struct notifier_block *nb) return err; rollback: - last = dev; - for_each_net(net) { - for_each_netdev(net, dev) { - if (dev == last) - goto outroll; - - if (dev->flags & IFF_UP) { - call_netdevice_notifier(nb, NETDEV_GOING_DOWN, - dev); - call_netdevice_notifier(nb, NETDEV_DOWN, dev); - } - call_netdevice_notifier(nb, NETDEV_UNREGISTER, dev); - } - } + for_each_net_continue_reverse(net) + call_netdevice_unregister_net_notifiers(nb, net); -outroll: raw_notifier_chain_unregister(&netdev_chain, nb); goto unlock; } From a30c7b429f2dd980202c912fcb76442364937b4d Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Mon, 30 Sep 2019 10:15:10 +0200 Subject: [PATCH 2/3] net: introduce per-netns netdevice notifiers Often the code for example in drivers is interested in getting notifier call only from certain network namespace. In addition to the existing global netdevice notifier chain introduce per-netns chains and allow users to register to that. Eventually this would eliminate unnecessary overhead in case there are many netdevices in many network namespaces. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- include/linux/netdevice.h | 3 ++ include/net/net_namespace.h | 3 ++ net/core/dev.c | 87 +++++++++++++++++++++++++++++++++++++ 3 files changed, 93 insertions(+) diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h index 7b183f724fc4f..fe45b2c72315f 100644 --- a/include/linux/netdevice.h +++ b/include/linux/netdevice.h @@ -2504,6 +2504,9 @@ const char *netdev_cmd_to_name(enum netdev_cmd cmd); int register_netdevice_notifier(struct notifier_block *nb); int unregister_netdevice_notifier(struct notifier_block *nb); +int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb); +int unregister_netdevice_notifier_net(struct net *net, + struct notifier_block *nb); struct netdev_notifier_info { struct net_device *dev; diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h index c5a98e03591df..5ac2bb16d4b3f 100644 --- a/include/net/net_namespace.h +++ b/include/net/net_namespace.h @@ -36,6 +36,7 @@ #include #include #include +#include struct user_namespace; struct proc_dir_entry; @@ -96,6 +97,8 @@ struct net { struct list_head dev_base_head; struct hlist_head *dev_name_head; struct hlist_head *dev_index_head; + struct raw_notifier_head netdev_chain; + unsigned int dev_base_seq; /* protected by rtnl_mutex */ int ifindex; unsigned int dev_unreg_count; diff --git a/net/core/dev.c b/net/core/dev.c index a8b70cb6c732a..c680225e0da84 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1874,6 +1874,80 @@ int unregister_netdevice_notifier(struct notifier_block *nb) } EXPORT_SYMBOL(unregister_netdevice_notifier); +/** + * register_netdevice_notifier_net - register a per-netns network notifier block + * @net: network namespace + * @nb: notifier + * + * Register a notifier to be called when network device events occur. + * The notifier passed is linked into the kernel structures and must + * not be reused until it has been unregistered. A negative errno code + * is returned on a failure. + * + * When registered all registration and up events are replayed + * to the new notifier to allow device to have a race free + * view of the network device list. + */ + +int register_netdevice_notifier_net(struct net *net, struct notifier_block *nb) +{ + int err; + + rtnl_lock(); + err = raw_notifier_chain_register(&net->netdev_chain, nb); + if (err) + goto unlock; + if (dev_boot_phase) + goto unlock; + + err = call_netdevice_register_net_notifiers(nb, net); + if (err) + goto chain_unregister; + +unlock: + rtnl_unlock(); + return err; + +chain_unregister: + raw_notifier_chain_unregister(&netdev_chain, nb); + goto unlock; +} +EXPORT_SYMBOL(register_netdevice_notifier_net); + +/** + * unregister_netdevice_notifier_net - unregister a per-netns + * network notifier block + * @net: network namespace + * @nb: notifier + * + * Unregister a notifier previously registered by + * register_netdevice_notifier(). The notifier is unlinked into the + * kernel structures and may then be reused. A negative errno code + * is returned on a failure. + * + * After unregistering unregister and down device events are synthesized + * for all devices on the device list to the removed notifier to remove + * the need for special case cleanup code. + */ + +int unregister_netdevice_notifier_net(struct net *net, + struct notifier_block *nb) +{ + int err; + + rtnl_lock(); + err = raw_notifier_chain_unregister(&net->netdev_chain, nb); + if (err) + goto unlock; + + call_netdevice_unregister_net_notifiers(nb, net); + +unlock: + rtnl_unlock(); + return err; +} +EXPORT_SYMBOL(unregister_netdevice_notifier_net); + /** * call_netdevice_notifiers_info - call all network notifier blocks * @val: value passed unmodified to notifier function @@ -1886,7 +1960,18 @@ EXPORT_SYMBOL(unregister_netdevice_notifier); static int call_netdevice_notifiers_info(unsigned long val, struct netdev_notifier_info *info) { + struct net *net = dev_net(info->dev); + int ret; + ASSERT_RTNL(); + + /* Run per-netns notifier block chain first, then run the global one. + * Hopefully, one day, the global one is going to be removed after + * all notifier block registrators get converted to be per-netns. + */ + ret = raw_notifier_call_chain(&net->netdev_chain, val, info); + if (ret & NOTIFY_STOP_MASK) + return ret; return raw_notifier_call_chain(&netdev_chain, val, info); } @@ -9785,6 +9870,8 @@ static int __net_init netdev_init(struct net *net) if (net->dev_index_head == NULL) goto err_idx; + RAW_INIT_NOTIFIER_HEAD(&net->netdev_chain); + return 0; err_idx: From f1cdaa077ccacb0d78a2da5c9df9b4aa7b7a0927 Mon Sep 17 00:00:00 2001 From: Jiri Pirko Date: Mon, 30 Sep 2019 10:15:11 +0200 Subject: [PATCH 3/3] mlxsw: spectrum: Use per-netns netdevice notifier registration The mlxsw_sp instance is not interested in events happening in other network namespaces. So use "_net" variants for netdevice notifier registration/unregistration and get only events which are happening in the net the instance is in. Signed-off-by: Jiri Pirko Signed-off-by: David S. Miller --- drivers/net/ethernet/mellanox/mlxsw/spectrum.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c index dcf9562bce8a9..a54a0dc82ff27 100644 --- a/drivers/net/ethernet/mellanox/mlxsw/spectrum.c +++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum.c @@ -4864,7 +4864,8 @@ static int mlxsw_sp_init(struct mlxsw_core *mlxsw_core, * respin. */ mlxsw_sp->netdevice_nb.notifier_call = mlxsw_sp_netdevice_event; - err = register_netdevice_notifier(&mlxsw_sp->netdevice_nb); + err = register_netdevice_notifier_net(&init_net, + &mlxsw_sp->netdevice_nb); if (err) { dev_err(mlxsw_sp->bus_info->dev, "Failed to register netdev notifier\n"); goto err_netdev_notifier; @@ -4887,7 +4888,8 @@ static int mlxsw_sp_init(struct mlxsw_core *mlxsw_core, err_ports_create: mlxsw_sp_dpipe_fini(mlxsw_sp); err_dpipe_init: - unregister_netdevice_notifier(&mlxsw_sp->netdevice_nb); + unregister_netdevice_notifier_net(&init_net, + &mlxsw_sp->netdevice_nb); err_netdev_notifier: if (mlxsw_sp->clock) mlxsw_sp->ptp_ops->fini(mlxsw_sp->ptp_state); @@ -4973,7 +4975,8 @@ static void mlxsw_sp_fini(struct mlxsw_core *mlxsw_core) mlxsw_sp_ports_remove(mlxsw_sp); mlxsw_sp_dpipe_fini(mlxsw_sp); - unregister_netdevice_notifier(&mlxsw_sp->netdevice_nb); + unregister_netdevice_notifier_net(&init_net, + &mlxsw_sp->netdevice_nb); if (mlxsw_sp->clock) { mlxsw_sp->ptp_ops->fini(mlxsw_sp->ptp_state); mlxsw_sp->ptp_ops->clock_fini(mlxsw_sp->clock);