Merge branch 'devlink-allow-devlink-instances-to-change-network-namespace'

Jiri Pirko says:

====================
devlink: allow devlink instances to change network namespace

Devlink from the beginning counts with network namespaces, but the
instances has been fixed to init_net.

Implement change of network namespace as part of "devlink reload"
procedure like this:

$ ip netns add testns1
$ devlink/devlink dev reload netdevsim/netdevsim10 netns testns1

This command reloads device "netdevsim10" into network
namespace "testns1".

Note that "devlink reload" reinstantiates driver objects, effectively it
reloads the driver instance, including possible hw reset etc. Newly
created netdevices respect the network namespace of the parent devlink
instance and according to that, they are created in target network
namespace.

Driver is able to refuse to be reloaded into different namespace. That
is the case of mlx4 right now.

FIB entries and rules are replayed during FIB notifier registration
which is triggered during reload (driver instance init). FIB notifier
is also registered to the target network namespace, that allows user
to use netdevsim devlink resources to setup per-namespace limits of FIB
entries and FIB rules. In fact, with multiple netdevsim instances
in each network namespace, user might setup different limits.
This maintains and extends current netdevsim resources behaviour.

Patch 1 prepares netdevsim code for the follow-up changes in the
patchset. It does not change the behaviour, only moves pet-init_netns
accounting to netdevsim instance, which is also in init_netns.

Patches 2-5 prepare the FIB notifier making it per-netns and to behave
correctly upon error conditions.

Patch 6 just exports a devlink_net helper so it can be used in drivers.

Patches 7-9 do preparations in mlxsw driver.

Patches 10-13 do preparations in netdevsim driver, namely patch 12
implements proper devlink reload where the driver instance objects are
actually re-created as they should be.

Patch 14 actually implements the possibility to reload into a different
network namespace.

Patch 15 adds needed selftests for devlink reload into namespace for
netdevsim driver.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

7 files changed, 43 insertions, 30 deletions

diff --git a/include/linux/mroute_base.h b/include/linux/mroute_base.h
index 34de06b426ef..8071148f29a6 100644
--- a/include/linux/mroute_base.h
+++ b/include/linux/mroute_base.h
@@ -47,16 +47,16 @@ struct vif_entry_notifier_info {
 };
 
 static inline int mr_call_vif_notifier(struct notifier_block *nb,
-				       struct net *net,
 				       unsigned short family,
 				       enum fib_event_type event_type,
 				       struct vif_device *vif,
-				       unsigned short vif_index, u32 tb_id)
+				       unsigned short vif_index, u32 tb_id,
+				       struct netlink_ext_ack *extack)
 {
 	struct vif_entry_notifier_info info = {
 		.info = {
 			.family = family,
-			.net = net,
+			.extack = extack,
 		},
 		.dev = vif->dev,
 		.vif_index = vif_index,
@@ -64,7 +64,7 @@ static inline int mr_call_vif_notifier(struct notifier_block *nb,
 		.tb_id = tb_id,
 	};
 
-	return call_fib_notifier(nb, net, event_type, &info.info);
+	return call_fib_notifier(nb, event_type, &info.info);
 }
 
 static inline int mr_call_vif_notifiers(struct net *net,
@@ -77,7 +77,6 @@ static inline int mr_call_vif_notifiers(struct net *net,
 	struct vif_entry_notifier_info info = {
 		.info = {
 			.family = family,
-			.net = net,
 		},
 		.dev = vif->dev,
 		.vif_index = vif_index,
@@ -173,21 +172,21 @@ struct mfc_entry_notifier_info {
 };
 
 static inline int mr_call_mfc_notifier(struct notifier_block *nb,
-				       struct net *net,
 				       unsigned short family,
 				       enum fib_event_type event_type,
-				       struct mr_mfc *mfc, u32 tb_id)
+				       struct mr_mfc *mfc, u32 tb_id,
+				       struct netlink_ext_ack *extack)
 {
 	struct mfc_entry_notifier_info info = {
 		.info = {
 			.family = family,
-			.net = net,
+			.extack = extack,
 		},
 		.mfc = mfc,
 		.tb_id = tb_id
 	};
 
-	return call_fib_notifier(nb, net, event_type, &info.info);
+	return call_fib_notifier(nb, event_type, &info.info);
 }
 
 static inline int mr_call_mfc_notifiers(struct net *net,
@@ -199,7 +198,6 @@ static inline int mr_call_mfc_notifiers(struct net *net,
 	struct mfc_entry_notifier_info info = {
 		.info = {
 			.family = family,
-			.net = net,
 		},
 		.mfc = mfc,
 		.tb_id = tb_id
@@ -301,10 +299,11 @@ int mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
 
 int mr_dump(struct net *net, struct notifier_block *nb, unsigned short family,
 	    int (*rules_dump)(struct net *net,
-			      struct notifier_block *nb),
+			      struct notifier_block *nb,
+			      struct netlink_ext_ack *extack),
 	    struct mr_table *(*mr_iter)(struct net *net,
 					struct mr_table *mrt),
-	    rwlock_t *mrt_lock);
+	    rwlock_t *mrt_lock, struct netlink_ext_ack *extack);
 #else
 static inline void vif_device_init(struct vif_device *v,
 				   struct net_device *dev,
@@ -355,10 +354,11 @@ mr_rtm_dumproute(struct sk_buff *skb, struct netlink_callback *cb,
 static inline int mr_dump(struct net *net, struct notifier_block *nb,
 			  unsigned short family,
 			  int (*rules_dump)(struct net *net,
-					    struct notifier_block *nb),
+					    struct notifier_block *nb,
+					    struct netlink_ext_ack *extack),
 			  struct mr_table *(*mr_iter)(struct net *net,
 						      struct mr_table *mrt),
-			  rwlock_t *mrt_lock)
+			  rwlock_t *mrt_lock, struct netlink_ext_ack *extack)
 {
 	return -EINVAL;
 }
diff --git a/include/net/devlink.h b/include/net/devlink.h
index 23e4b65ec9df..3c9d4a063c98 100644
--- a/include/net/devlink.h
+++ b/include/net/devlink.h
@@ -643,7 +643,7 @@ enum devlink_trap_group_generic_id {
 	}
 
 struct devlink_ops {
-	int (*reload_down)(struct devlink *devlink,
+	int (*reload_down)(struct devlink *devlink, bool netns_change,
 			   struct netlink_ext_ack *extack);
 	int (*reload_up)(struct devlink *devlink,
 			 struct netlink_ext_ack *extack);
@@ -771,6 +771,7 @@ static inline struct devlink *netdev_to_devlink(struct net_device *dev)
 
 struct ib_device;
 
+struct net *devlink_net(const struct devlink *devlink);
 struct devlink *devlink_alloc(const struct devlink_ops *ops, size_t priv_size);
 int devlink_register(struct devlink *devlink, struct device *dev);
 void devlink_unregister(struct devlink *devlink);
diff --git a/include/net/fib_notifier.h b/include/net/fib_notifier.h
index c49d7bfb5c30..6d59221ff05a 100644
--- a/include/net/fib_notifier.h
+++ b/include/net/fib_notifier.h
@@ -8,7 +8,6 @@
 struct module;
 
 struct fib_notifier_info {
-	struct net *net;
 	int family;
 	struct netlink_ext_ack  *extack;
 };
@@ -30,19 +29,21 @@ struct fib_notifier_ops {
 	int family;
 	struct list_head list;
 	unsigned int (*fib_seq_read)(struct net *net);
-	int (*fib_dump)(struct net *net, struct notifier_block *nb);
+	int (*fib_dump)(struct net *net, struct notifier_block *nb,
+			struct netlink_ext_ack *extack);
 	struct module *owner;
 	struct rcu_head rcu;
 };
 
-int call_fib_notifier(struct notifier_block *nb, struct net *net,
+int call_fib_notifier(struct notifier_block *nb,
 		      enum fib_event_type event_type,
 		      struct fib_notifier_info *info);
 int call_fib_notifiers(struct net *net, enum fib_event_type event_type,
 		       struct fib_notifier_info *info);
-int register_fib_notifier(struct notifier_block *nb,
-			  void (*cb)(struct notifier_block *nb));
-int unregister_fib_notifier(struct notifier_block *nb);
+int register_fib_notifier(struct net *net, struct notifier_block *nb,
+			  void (*cb)(struct notifier_block *nb),
+			  struct netlink_ext_ack *extack);
+int unregister_fib_notifier(struct net *net, struct notifier_block *nb);
 struct fib_notifier_ops *
 fib_notifier_ops_register(const struct fib_notifier_ops *tmpl, struct net *net);
 void fib_notifier_ops_unregister(struct fib_notifier_ops *ops);
diff --git a/include/net/fib_rules.h b/include/net/fib_rules.h
index 20dcadd8eed9..54e227e6b06a 100644
--- a/include/net/fib_rules.h
+++ b/include/net/fib_rules.h
@@ -194,7 +194,8 @@ int fib_rules_lookup(struct fib_rules_ops *, struct flowi *, int flags,
 int fib_default_rule_add(struct fib_rules_ops *, u32 pref, u32 table,
 			 u32 flags);
 bool fib_rule_matchall(const struct fib_rule *rule);
-int fib_rules_dump(struct net *net, struct notifier_block *nb, int family);
+int fib_rules_dump(struct net *net, struct notifier_block *nb, int family,
+		   struct netlink_ext_ack *extack);
 unsigned int fib_rules_seq_read(struct net *net, int family);
 
 int fib_nl_newrule(struct sk_buff *skb, struct nlmsghdr *nlh,
diff --git a/include/net/ip6_fib.h b/include/net/ip6_fib.h
index 4b5656c71abc..5d1615463138 100644
--- a/include/net/ip6_fib.h
+++ b/include/net/ip6_fib.h
@@ -478,7 +478,7 @@ struct ipv6_route_iter {
 
 extern const struct seq_operations ipv6_route_seq_ops;
 
-int call_fib6_notifier(struct notifier_block *nb, struct net *net,
+int call_fib6_notifier(struct notifier_block *nb,
 		       enum fib_event_type event_type,
 		       struct fib_notifier_info *info);
 int call_fib6_notifiers(struct net *net, enum fib_event_type event_type,
@@ -488,7 +488,8 @@ int __net_init fib6_notifier_init(struct net *net);
 void __net_exit fib6_notifier_exit(struct net *net);
 
 unsigned int fib6_tables_seq_read(struct net *net);
-int fib6_tables_dump(struct net *net, struct notifier_block *nb);
+int fib6_tables_dump(struct net *net, struct notifier_block *nb,
+		     struct netlink_ext_ack *extack);
 
 void fib6_update_sernum(struct net *net, struct fib6_info *rt);
 void fib6_update_sernum_upto_root(struct net *net, struct fib6_info *rt);
@@ -504,7 +505,8 @@ static inline bool fib6_metric_locked(struct fib6_info *f6i, int metric)
 int fib6_rules_init(void);
 void fib6_rules_cleanup(void);
 bool fib6_rule_default(const struct fib_rule *rule);
-int fib6_rules_dump(struct net *net, struct notifier_block *nb);
+int fib6_rules_dump(struct net *net, struct notifier_block *nb,
+		    struct netlink_ext_ack *extack);
 unsigned int fib6_rules_seq_read(struct net *net);
 
 static inline bool fib6_rules_early_flow_dissect(struct net *net,
@@ -537,7 +539,8 @@ static inline bool fib6_rule_default(const struct fib_rule *rule)
 {
 	return true;
 }
-static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb)
+static inline int fib6_rules_dump(struct net *net, struct notifier_block *nb,
+				  struct netlink_ext_ack *extack)
 {
 	return 0;
 }
diff --git a/include/net/ip_fib.h b/include/net/ip_fib.h
index ab1ca9e238d2..52b2406a5dfc 100644
--- a/include/net/ip_fib.h
+++ b/include/net/ip_fib.h
@@ -219,7 +219,7 @@ struct fib_nh_notifier_info {
 	struct fib_nh *fib_nh;
 };
 
-int call_fib4_notifier(struct notifier_block *nb, struct net *net,
+int call_fib4_notifier(struct notifier_block *nb,
 		       enum fib_event_type event_type,
 		       struct fib_notifier_info *info);
 int call_fib4_notifiers(struct net *net, enum fib_event_type event_type,
@@ -229,7 +229,8 @@ int __net_init fib4_notifier_init(struct net *net);
 void __net_exit fib4_notifier_exit(struct net *net);
 
 void fib_info_notify_update(struct net *net, struct nl_info *info);
-void fib_notify(struct net *net, struct notifier_block *nb);
+int fib_notify(struct net *net, struct notifier_block *nb,
+	       struct netlink_ext_ack *extack);
 
 struct fib_table {
 	struct hlist_node	tb_hlist;
@@ -315,7 +316,8 @@ static inline bool fib4_rule_default(const struct fib_rule *rule)
 	return true;
 }
 
-static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb)
+static inline int fib4_rules_dump(struct net *net, struct notifier_block *nb,
+				  struct netlink_ext_ack *extack)
 {
 	return 0;
 }
@@ -377,7 +379,8 @@ out:
 }
 
 bool fib4_rule_default(const struct fib_rule *rule);
-int fib4_rules_dump(struct net *net, struct notifier_block *nb);
+int fib4_rules_dump(struct net *net, struct notifier_block *nb,
+		    struct netlink_ext_ack *extack);
 unsigned int fib4_rules_seq_read(struct net *net);
 
 static inline bool fib4_rules_early_flow_dissect(struct net *net,
diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index 580b7a2e40e1..b558ea88b766 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -421,6 +421,10 @@ enum devlink_attr {
 
 	DEVLINK_ATTR_RELOAD_FAILED,			/* u8 0 or 1 */
 
+	DEVLINK_ATTR_NETNS_FD,			/* u32 */
+	DEVLINK_ATTR_NETNS_PID,			/* u32 */
+	DEVLINK_ATTR_NETNS_ID,			/* u32 */
+
 	/* add new attributes above here, update the policy in devlink.c */
 
 	__DEVLINK_ATTR_MAX,