sched: Remove USER_SCHED

Remove the USER_SCHED feature. It has been scheduled to be removed in
2.6.34 as per http://marc.info/?l=linux-kernel&m=125728479022976&w=2

Signed-off-by: Dhaval Giani <dhaval.giani@gmail.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <1263990378.24844.3.camel@localhost>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 0 insertions, 305 deletions

diff --git a/kernel/user.c b/kernel/user.c
index 46d0165ca70c..766467b3bcb7 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -56,9 +56,6 @@ struct user_struct root_user = {
         .sigpending     = ATOMIC_INIT(0),
         .locked_shm     = 0,
         .user_ns        = &init_user_ns,
-#ifdef CONFIG_USER_SCHED
-        .tg             = &init_task_group,
-#endif
 };
 
 /*
@@ -75,268 +72,6 @@ static void uid_hash_remove(struct user_struct *up)
         put_user_ns(up->user_ns);
 }
 
-#ifdef CONFIG_USER_SCHED
-
-static void sched_destroy_user(struct user_struct *up)
-{
-        sched_destroy_group(up->tg);
-}
-
-static int sched_create_user(struct user_struct *up)
-{
-        int rc = 0;
-
-        up->tg = sched_create_group(&root_task_group);
-        if (IS_ERR(up->tg))
-                rc = -ENOMEM;
-
-        set_tg_uid(up);
-
-        return rc;
-}
-
-#else   /* CONFIG_USER_SCHED */
-
-static void sched_destroy_user(struct user_struct *up) { }
-static int sched_create_user(struct user_struct *up) { return 0; }
-
-#endif  /* CONFIG_USER_SCHED */
-
-#if defined(CONFIG_USER_SCHED) && defined(CONFIG_SYSFS)
-
-static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
-{
-        struct user_struct *user;
-        struct hlist_node *h;
-
-        hlist_for_each_entry(user, h, hashent, uidhash_node) {
-                if (user->uid == uid) {
-                        /* possibly resurrect an "almost deleted" object */
-                        if (atomic_inc_return(&user->__count) == 1)
-                                cancel_delayed_work(&user->work);
-                        return user;
-                }
-        }
-
-        return NULL;
-}
-
-static struct kset *uids_kset; /* represents the /sys/kernel/uids/ directory */
-static DEFINE_MUTEX(uids_mutex);
-
-static inline void uids_mutex_lock(void)
-{
-        mutex_lock(&uids_mutex);
-}
-
-static inline void uids_mutex_unlock(void)
-{
-        mutex_unlock(&uids_mutex);
-}
-
-/* uid directory attributes */
-#ifdef CONFIG_FAIR_GROUP_SCHED
-static ssize_t cpu_shares_show(struct kobject *kobj,
-                               struct kobj_attribute *attr,
-                               char *buf)
-{
-        struct user_struct *up = container_of(kobj, struct user_struct, kobj);
-
-        return sprintf(buf, "%lu\n", sched_group_shares(up->tg));
-}
-
-static ssize_t cpu_shares_store(struct kobject *kobj,
-                                struct kobj_attribute *attr,
-                                const char *buf, size_t size)
-{
-        struct user_struct *up = container_of(kobj, struct user_struct, kobj);
-        unsigned long shares;
-        int rc;
-
-        sscanf(buf, "%lu", &shares);
-
-        rc = sched_group_set_shares(up->tg, shares);
-
-        return (rc ? rc : size);
-}
-
-static struct kobj_attribute cpu_share_attr =
-        __ATTR(cpu_share, 0644, cpu_shares_show, cpu_shares_store);
-#endif
-
-#ifdef CONFIG_RT_GROUP_SCHED
-static ssize_t cpu_rt_runtime_show(struct kobject *kobj,
-                                   struct kobj_attribute *attr,
-                                   char *buf)
-{
-        struct user_struct *up = container_of(kobj, struct user_struct, kobj);
-
-        return sprintf(buf, "%ld\n", sched_group_rt_runtime(up->tg));
-}
-
-static ssize_t cpu_rt_runtime_store(struct kobject *kobj,
-                                    struct kobj_attribute *attr,
-                                    const char *buf, size_t size)
-{
-        struct user_struct *up = container_of(kobj, struct user_struct, kobj);
-        unsigned long rt_runtime;
-        int rc;
-
-        sscanf(buf, "%ld", &rt_runtime);
-
-        rc = sched_group_set_rt_runtime(up->tg, rt_runtime);
-
-        return (rc ? rc : size);
-}
-
-static struct kobj_attribute cpu_rt_runtime_attr =
-        __ATTR(cpu_rt_runtime, 0644, cpu_rt_runtime_show, cpu_rt_runtime_store);
-
-static ssize_t cpu_rt_period_show(struct kobject *kobj,
-                                   struct kobj_attribute *attr,
-                                   char *buf)
-{
-        struct user_struct *up = container_of(kobj, struct user_struct, kobj);
-
-        return sprintf(buf, "%lu\n", sched_group_rt_period(up->tg));
-}
-
-static ssize_t cpu_rt_period_store(struct kobject *kobj,
-                                    struct kobj_attribute *attr,
-                                    const char *buf, size_t size)
-{
-        struct user_struct *up = container_of(kobj, struct user_struct, kobj);
-        unsigned long rt_period;
-        int rc;
-
-        sscanf(buf, "%lu", &rt_period);
-
-        rc = sched_group_set_rt_period(up->tg, rt_period);
-
-        return (rc ? rc : size);
-}
-
-static struct kobj_attribute cpu_rt_period_attr =
-        __ATTR(cpu_rt_period, 0644, cpu_rt_period_show, cpu_rt_period_store);
-#endif
-
-/* default attributes per uid directory */
-static struct attribute *uids_attributes[] = {
-#ifdef CONFIG_FAIR_GROUP_SCHED
-        &cpu_share_attr.attr,
-#endif
-#ifdef CONFIG_RT_GROUP_SCHED
-        &cpu_rt_runtime_attr.attr,
-        &cpu_rt_period_attr.attr,
-#endif
-        NULL
-};
-
-/* the lifetime of user_struct is not managed by the core (now) */
-static void uids_release(struct kobject *kobj)
-{
-        return;
-}
-
-static struct kobj_type uids_ktype = {
-        .sysfs_ops = &kobj_sysfs_ops,
-        .default_attrs = uids_attributes,
-        .release = uids_release,
-};
-
-/*
- * Create /sys/kernel/uids/<uid>/cpu_share file for this user
- * We do not create this file for users in a user namespace (until
- * sysfs tagging is implemented).
- *
- * See Documentation/scheduler/sched-design-CFS.txt for ramifications.
- */
-static int uids_user_create(struct user_struct *up)
-{
-        struct kobject *kobj = &up->kobj;
-        int error;
-
-        memset(kobj, 0, sizeof(struct kobject));
-        if (up->user_ns != &init_user_ns)
-                return 0;
-        kobj->kset = uids_kset;
-        error = kobject_init_and_add(kobj, &uids_ktype, NULL, "%d", up->uid);
-        if (error) {
-                kobject_put(kobj);
-                goto done;
-        }
-
-        kobject_uevent(kobj, KOBJ_ADD);
-done:
-        return error;
-}
-
-/* create these entries in sysfs:
- *      "/sys/kernel/uids" directory
- *      "/sys/kernel/uids/0" directory (for root user)
- *      "/sys/kernel/uids/0/cpu_share" file (for root user)
- */
-int __init uids_sysfs_init(void)
-{
-        uids_kset = kset_create_and_add("uids", NULL, kernel_kobj);
-        if (!uids_kset)
-                return -ENOMEM;
-
-        return uids_user_create(&root_user);
-}
-
-/* delayed work function to remove sysfs directory for a user and free up
- * corresponding structures.
- */
-static void cleanup_user_struct(struct work_struct *w)
-{
-        struct user_struct *up = container_of(w, struct user_struct, work.work);
-        unsigned long flags;
-        int remove_user = 0;
-
-        /* Make uid_hash_remove() + sysfs_remove_file() + kobject_del()
-         * atomic.
-         */
-        uids_mutex_lock();
-
-        spin_lock_irqsave(&uidhash_lock, flags);
-        if (atomic_read(&up->__count) == 0) {
-                uid_hash_remove(up);
-                remove_user = 1;
-        }
-        spin_unlock_irqrestore(&uidhash_lock, flags);
-
-        if (!remove_user)
-                goto done;
-
-        if (up->user_ns == &init_user_ns) {
-                kobject_uevent(&up->kobj, KOBJ_REMOVE);
-                kobject_del(&up->kobj);
-                kobject_put(&up->kobj);
-        }
-
-        sched_destroy_user(up);
-        key_put(up->uid_keyring);
-        key_put(up->session_keyring);
-        kmem_cache_free(uid_cachep, up);
-
-done:
-        uids_mutex_unlock();
-}
-
-/* IRQs are disabled and uidhash_lock is held upon function entry.
- * IRQ state (as stored in flags) is restored and uidhash_lock released
- * upon function exit.
- */
-static void free_user(struct user_struct *up, unsigned long flags)
-{
-        INIT_DELAYED_WORK(&up->work, cleanup_user_struct);
-        schedule_delayed_work(&up->work, msecs_to_jiffies(1000));
-        spin_unlock_irqrestore(&uidhash_lock, flags);
-}
-
-#else   /* CONFIG_USER_SCHED && CONFIG_SYSFS */
-
 static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
 {
         struct user_struct *user;
@@ -352,11 +87,6 @@ static struct user_struct *uid_hash_find(uid_t uid, struct hlist_head *hashent)
         return NULL;
 }
 
-int uids_sysfs_init(void) { return 0; }
-static inline int uids_user_create(struct user_struct *up) { return 0; }
-static inline void uids_mutex_lock(void) { }
-static inline void uids_mutex_unlock(void) { }
-
 /* IRQs are disabled and uidhash_lock is held upon function entry.
  * IRQ state (as stored in flags) is restored and uidhash_lock released
  * upon function exit.
@@ -365,32 +95,11 @@ 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);
         kmem_cache_free(uid_cachep, up);
 }
 
-#endif
-
-#if defined(CONFIG_RT_GROUP_SCHED) && defined(CONFIG_USER_SCHED)
-/*
- * We need to check if a setuid can take place. This function should be called
- * before successfully completing the setuid.
- */
-int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
-{
-
-        return sched_rt_can_attach(up->tg, tsk);
-
-}
-#else
-int task_can_switch_user(struct user_struct *up, struct task_struct *tsk)
-{
-        return 1;
-}
-#endif
-
 /*
  * Locate the user_struct for the passed UID.  If found, take a ref on it.  The
  * caller must undo that ref with free_uid().
@@ -431,8 +140,6 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
         /* Make uid_hash_find() + uids_user_create() + uid_hash_insert()
          * atomic.
          */
-        uids_mutex_lock();
-
         spin_lock_irq(&uidhash_lock);
         up = uid_hash_find(uid, hashent);
         spin_unlock_irq(&uidhash_lock);
@@ -445,14 +152,8 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
                 new->uid = uid;
                 atomic_set(&new->__count, 1);
 
-                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;
-
                 /*
                  * Before adding this, check whether we raced
                  * on adding the same user already..
@@ -475,17 +176,11 @@ struct user_struct *alloc_uid(struct user_namespace *ns, uid_t uid)
                 spin_unlock_irq(&uidhash_lock);
         }
 
-        uids_mutex_unlock();
-
         return up;
 
-out_destoy_sched:
-        sched_destroy_user(new);
         put_user_ns(new->user_ns);
-out_free_user:
         kmem_cache_free(uid_cachep, new);
 out_unlock:
-        uids_mutex_unlock();
         return NULL;
 }