User namespaces: set of cleanups (v2)

[mv-sheeva.git] / kernel / user.c

diff --git a/kernel/user.c b/kernel/user.c
index d476307dd4b00109975b09837b62cace9bd2048d..c0ef3a464438badd79da9bb4195e43dba8ce6437 100644 (file)
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -20,9 +20,9 @@
 
 struct user_namespace init_user_ns = {
        .kref = {
-               .refcount       = ATOMIC_INIT(2),
+               .refcount       = ATOMIC_INIT(1),
        },
-       .root_user = &root_user,
+       .creator = &root_user,
 };
 EXPORT_SYMBOL_GPL(init_user_ns);
 
@@ -48,12 +48,14 @@ static struct kmem_cache *uid_cachep;
  */
 static DEFINE_SPINLOCK(uidhash_lock);
 
+/* root_user.__count is 2, 1 for init task cred, 1 for init_user_ns->creator */
 struct user_struct root_user = {
-       .__count        = ATOMIC_INIT(1),
+       .__count        = ATOMIC_INIT(2),
        .processes      = ATOMIC_INIT(1),
        .files          = ATOMIC_INIT(0),
        .sigpending     = ATOMIC_INIT(0),
        .locked_shm     = 0,
+       .user_ns        = &init_user_ns,
 #ifdef CONFIG_USER_SCHED
        .tg             = &init_task_group,
 #endif
@@ -314,12 +316,13 @@ done:
  * IRQ state (as stored in flags) is restored and uidhash_lock released
  * upon function exit.
  */
-static inline void free_user(struct user_struct *up, unsigned long flags)
+static void free_user(struct user_struct *up, unsigned long flags)
 {
        /* restore back the count */
        atomic_inc(&up->__count);
        spin_unlock_irqrestore(&uidhash_lock, flags);
 
+       put_user_ns(up->user_ns);
        INIT_WORK(&up->work, remove_user_sysfs_dir);
        schedule_work(&up->work);
 }
@@ -335,13 +338,14 @@ static inline void uids_mutex_unlock(void) { }
  * IRQ state (as stored in flags) is restored and uidhash_lock released
  * upon function exit.
  */
-static inline void free_user(struct user_struct *up, unsigned long flags)
+static void free_user(struct user_struct *up, unsigned long flags)
 {
        uid_hash_remove(up);
        spin_unlock_irqrestore(&uidhash_lock, flags);
        sched_destroy_user(up);
        key_put(up->uid_keyring);
        key_put(up->session_keyring);
+       put_user_ns(up->user_ns);
        kmem_cache_free(uid_cachep, up);
 }
 
@@ -357,7 +361,7 @@ struct user_struct *find_user(uid_t uid)
 {
        struct user_struct *ret;
        unsigned long flags;
-       struct user_namespace *ns = current->nsproxy->user_ns;
+       struct user_namespace *ns = current_user()->user_ns;
 
        spin_lock_irqsave(&uidhash_lock, flags);
        ret = uid_hash_find(uid, uidhashentry(ns, uid));
@@ -404,6 +408,8 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
                if (sched_create_user(new) < 0)
                        goto out_free_user;
 
+               new->user_ns = get_user_ns(ns);
+
                if (uids_user_create(new))
                        goto out_destoy_sched;
 
@@ -427,7 +433,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
                        up = new;
                }
                spin_unlock_irq(&uidhash_lock);
-
        }
 
        uids_mutex_unlock();
@@ -436,6 +441,7 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
 
 out_destoy_sched:
        sched_destroy_user(new);
+       put_user_ns(new->user_ns);
 out_free_user:
        kmem_cache_free(uid_cachep, new);
 out_unlock:
@@ -443,33 +449,6 @@ out_unlock:
        return NULL;
 }
 
-#ifdef CONFIG_USER_NS
-void release_uids(struct user_namespace *ns)
-{
-       int i;
-       unsigned long flags;
-       struct hlist_head *head;
-       struct hlist_node *nd;
-
-       spin_lock_irqsave(&uidhash_lock, flags);
-       /*
-        * collapse the chains so that the user_struct-s will
-        * be still alive, but not in hashes. subsequent free_uid()
-        * will free them.
-        */
-       for (i = 0; i < UIDHASH_SZ; i++) {
-               head = ns->uidhash_table + i;
-               while (!hlist_empty(head)) {
-                       nd = head->first;
-                       hlist_del_init(nd);
-               }
-       }
-       spin_unlock_irqrestore(&uidhash_lock, flags);
-
-       free_uid(ns->root_user);
-}
-#endif
-
 static int __init uid_cache_init(void)
 {
        int n;