diff options
Diffstat (limited to 'kernel/nsproxy.c')
| -rw-r--r-- | kernel/nsproxy.c | 40 |
1 files changed, 27 insertions, 13 deletions
diff --git a/kernel/nsproxy.c b/kernel/nsproxy.c index e981c61304f..c8ef7c2992e 100644 --- a/kernel/nsproxy.c +++ b/kernel/nsproxy.c @@ -26,19 +26,6 @@ static struct kmem_cache *nsproxy_cachep; struct nsproxy init_nsproxy = INIT_NSPROXY(init_nsproxy); -static inline void get_nsproxy(struct nsproxy *ns) -{ - atomic_inc(&ns->count); -} - -void get_task_namespaces(struct task_struct *tsk) -{ - struct nsproxy *ns = tsk->nsproxy; - if (ns) { - get_nsproxy(ns); - } -} - /* * creates a copy of "orig" with refcount 1. */ @@ -216,6 +203,33 @@ out: return err; } +void switch_task_namespaces(struct task_struct *p, struct nsproxy *new) +{ + struct nsproxy *ns; + + might_sleep(); + + ns = p->nsproxy; + + rcu_assign_pointer(p->nsproxy, new); + + if (ns && atomic_dec_and_test(&ns->count)) { + /* + * wait for others to get what they want from this nsproxy. + * + * cannot release this nsproxy via the call_rcu() since + * put_mnt_ns() will want to sleep + */ + synchronize_rcu(); + free_nsproxy(ns); + } +} + +void exit_task_namespaces(struct task_struct *p) +{ + switch_task_namespaces(p, NULL); +} + static int __init nsproxy_cache_init(void) { nsproxy_cachep = KMEM_CACHE(nsproxy, SLAB_PANIC); |