aboutsummaryrefslogtreecommitdiffstats
path: root/include/linux/kobject_ns.h
diff options
context:
space:
mode:
authorAl Viro <viro@zeniv.linux.org.uk>2011-06-08 21:13:01 -0400
committerAl Viro <viro@zeniv.linux.org.uk>2011-06-12 17:45:41 -0400
commita685e08987d1edf1995b76511d4c98ea0e905377 (patch)
tree1d42593e2bc320f8d93b98851b2df0fd432e3859 /include/linux/kobject_ns.h
parentdde194a64bb5c3fd05d965775dc92e8a4920a53a (diff)
Delay struct net freeing while there's a sysfs instance refering to it
* new refcount in struct net, controlling actual freeing of the memory * new method in kobj_ns_type_operations (->drop_ns()) * ->current_ns() semantics change - it's supposed to be followed by corresponding ->drop_ns(). For struct net in case of CONFIG_NET_NS it bumps the new refcount; net_drop_ns() decrements it and calls net_free() if the last reference has been dropped. Method renamed to ->grab_current_ns(). * old net_free() callers call net_drop_ns() instead. * sysfs_exit_ns() is gone, along with a large part of callchain leading to it; now that the references stored in ->ns[...] stay valid we do not need to hunt them down and replace them with NULL. That fixes problems in sysfs_lookup() and sysfs_readdir(), along with getting rid of sb->s_instances abuse. Note that struct net *shutdown* logics has not changed - net_cleanup() is called exactly when it used to be called. The only thing postponed by having a sysfs instance refering to that struct net is actual freeing of memory occupied by struct net. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'include/linux/kobject_ns.h')
-rw-r--r--include/linux/kobject_ns.h10
1 files changed, 6 insertions, 4 deletions
diff --git a/include/linux/kobject_ns.h b/include/linux/kobject_ns.h
index 82cb5bf461fb..f66b065a8b5f 100644
--- a/include/linux/kobject_ns.h
+++ b/include/linux/kobject_ns.h
@@ -32,15 +32,17 @@ enum kobj_ns_type {
32 32
33/* 33/*
34 * Callbacks so sysfs can determine namespaces 34 * Callbacks so sysfs can determine namespaces
35 * @current_ns: return calling task's namespace 35 * @grab_current_ns: return a new reference to calling task's namespace
36 * @netlink_ns: return namespace to which a sock belongs (right?) 36 * @netlink_ns: return namespace to which a sock belongs (right?)
37 * @initial_ns: return the initial namespace (i.e. init_net_ns) 37 * @initial_ns: return the initial namespace (i.e. init_net_ns)
38 * @drop_ns: drops a reference to namespace
38 */ 39 */
39struct kobj_ns_type_operations { 40struct kobj_ns_type_operations {
40 enum kobj_ns_type type; 41 enum kobj_ns_type type;
41 const void *(*current_ns)(void); 42 void *(*grab_current_ns)(void);
42 const void *(*netlink_ns)(struct sock *sk); 43 const void *(*netlink_ns)(struct sock *sk);
43 const void *(*initial_ns)(void); 44 const void *(*initial_ns)(void);
45 void (*drop_ns)(void *);
44}; 46};
45 47
46int kobj_ns_type_register(const struct kobj_ns_type_operations *ops); 48int kobj_ns_type_register(const struct kobj_ns_type_operations *ops);
@@ -48,9 +50,9 @@ int kobj_ns_type_registered(enum kobj_ns_type type);
48const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent); 50const struct kobj_ns_type_operations *kobj_child_ns_ops(struct kobject *parent);
49const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj); 51const struct kobj_ns_type_operations *kobj_ns_ops(struct kobject *kobj);
50 52
51const void *kobj_ns_current(enum kobj_ns_type type); 53void *kobj_ns_grab_current(enum kobj_ns_type type);
52const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk); 54const void *kobj_ns_netlink(enum kobj_ns_type type, struct sock *sk);
53const void *kobj_ns_initial(enum kobj_ns_type type); 55const void *kobj_ns_initial(enum kobj_ns_type type);
54void kobj_ns_exit(enum kobj_ns_type type, const void *ns); 56void kobj_ns_drop(enum kobj_ns_type type, void *ns);
55 57
56#endif /* _LINUX_KOBJECT_NS_H */ 58#endif /* _LINUX_KOBJECT_NS_H */