namespaces: cleanup the code managed with PID_NS option

Just like with the user namespaces, move the namespace management code into
the separate .c file and mark the (already existing) PID_NS option as "depend
on NAMESPACES"

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Herbert Poetzl <herbert@13thfloor.at>
Cc: Kirill Korotaev <dev@sw.ru>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 181 deletions

diff --git a/kernel/pid.c b/kernel/pid.c
index 3b30bccdfcdc..939746fb4ce7 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -41,7 +41,6 @@
 static struct hlist_head *pid_hash;
 static int pidhash_shift;
 struct pid init_struct_pid = INIT_STRUCT_PID;
-static struct kmem_cache *pid_ns_cachep;
 
 int pid_max = PID_MAX_DEFAULT;
 
@@ -181,7 +180,7 @@ static int alloc_pidmap(struct pid_namespace *pid_ns)
         return -1;
 }
 
-static int next_pidmap(struct pid_namespace *pid_ns, int last)
+int next_pidmap(struct pid_namespace *pid_ns, int last)
 {
         int offset;
         struct pidmap *map, *end;
@@ -488,180 +487,6 @@ struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
 }
 EXPORT_SYMBOL_GPL(find_get_pid);
 
-struct pid_cache {
-        int nr_ids;
-        char name[16];
-        struct kmem_cache *cachep;
-        struct list_head list;
-};
-
-static LIST_HEAD(pid_caches_lh);
-static DEFINE_MUTEX(pid_caches_mutex);
-
-/*
- * creates the kmem cache to allocate pids from.
- * @nr_ids: the number of numerical ids this pid will have to carry
- */
-
-static struct kmem_cache *create_pid_cachep(int nr_ids)
-{
-        struct pid_cache *pcache;
-        struct kmem_cache *cachep;
-
-        mutex_lock(&pid_caches_mutex);
-        list_for_each_entry (pcache, &pid_caches_lh, list)
-                if (pcache->nr_ids == nr_ids)
-                        goto out;
-
-        pcache = kmalloc(sizeof(struct pid_cache), GFP_KERNEL);
-        if (pcache == NULL)
-                goto err_alloc;
-
-        snprintf(pcache->name, sizeof(pcache->name), "pid_%d", nr_ids);
-        cachep = kmem_cache_create(pcache->name,
-                        sizeof(struct pid) + (nr_ids - 1) * sizeof(struct upid),
-                        0, SLAB_HWCACHE_ALIGN, NULL);
-        if (cachep == NULL)
-                goto err_cachep;
-
-        pcache->nr_ids = nr_ids;
-        pcache->cachep = cachep;
-        list_add(&pcache->list, &pid_caches_lh);
-out:
-        mutex_unlock(&pid_caches_mutex);
-        return pcache->cachep;
-
-err_cachep:
-        kfree(pcache);
-err_alloc:
-        mutex_unlock(&pid_caches_mutex);
-        return NULL;
-}
-
-#ifdef CONFIG_PID_NS
-static struct pid_namespace *create_pid_namespace(int level)
-{
-        struct pid_namespace *ns;
-        int i;
-
-        ns = kmem_cache_alloc(pid_ns_cachep, GFP_KERNEL);
-        if (ns == NULL)
-                goto out;
-
-        ns->pidmap[0].page = kzalloc(PAGE_SIZE, GFP_KERNEL);
-        if (!ns->pidmap[0].page)
-                goto out_free;
-
-        ns->pid_cachep = create_pid_cachep(level + 1);
-        if (ns->pid_cachep == NULL)
-                goto out_free_map;
-
-        kref_init(&ns->kref);
-        ns->last_pid = 0;
-        ns->child_reaper = NULL;
-        ns->level = level;
-
-        set_bit(0, ns->pidmap[0].page);
-        atomic_set(&ns->pidmap[0].nr_free, BITS_PER_PAGE - 1);
-
-        for (i = 1; i < PIDMAP_ENTRIES; i++) {
-                ns->pidmap[i].page = 0;
-                atomic_set(&ns->pidmap[i].nr_free, BITS_PER_PAGE);
-        }
-
-        return ns;
-
-out_free_map:
-        kfree(ns->pidmap[0].page);
-out_free:
-        kmem_cache_free(pid_ns_cachep, ns);
-out:
-        return ERR_PTR(-ENOMEM);
-}
-
-static void destroy_pid_namespace(struct pid_namespace *ns)
-{
-        int i;
-
-        for (i = 0; i < PIDMAP_ENTRIES; i++)
-                kfree(ns->pidmap[i].page);
-        kmem_cache_free(pid_ns_cachep, ns);
-}
-
-struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old_ns)
-{
-        struct pid_namespace *new_ns;
-
-        BUG_ON(!old_ns);
-        new_ns = get_pid_ns(old_ns);
-        if (!(flags & CLONE_NEWPID))
-                goto out;
-
-        new_ns = ERR_PTR(-EINVAL);
-        if (flags & CLONE_THREAD)
-                goto out_put;
-
-        new_ns = create_pid_namespace(old_ns->level + 1);
-        if (!IS_ERR(new_ns))
-                new_ns->parent = get_pid_ns(old_ns);
-
-out_put:
-        put_pid_ns(old_ns);
-out:
-        return new_ns;
-}
-
-void free_pid_ns(struct kref *kref)
-{
-        struct pid_namespace *ns, *parent;
-
-        ns = container_of(kref, struct pid_namespace, kref);
-
-        parent = ns->parent;
-        destroy_pid_namespace(ns);
-
-        if (parent != NULL)
-                put_pid_ns(parent);
-}
-#endif /* CONFIG_PID_NS */
-
-void zap_pid_ns_processes(struct pid_namespace *pid_ns)
-{
-        int nr;
-        int rc;
-
-        /*
-         * The last thread in the cgroup-init thread group is terminating.
-         * Find remaining pid_ts in the namespace, signal and wait for them
-         * to exit.
-         *
-         * Note:  This signals each threads in the namespace - even those that
-         *        belong to the same thread group, To avoid this, we would have
-         *        to walk the entire tasklist looking a processes in this
-         *        namespace, but that could be unnecessarily expensive if the
-         *        pid namespace has just a few processes. Or we need to
-         *        maintain a tasklist for each pid namespace.
-         *
-         */
-        read_lock(&tasklist_lock);
-        nr = next_pidmap(pid_ns, 1);
-        while (nr > 0) {
-                kill_proc_info(SIGKILL, SEND_SIG_PRIV, nr);
-                nr = next_pidmap(pid_ns, nr);
-        }
-        read_unlock(&tasklist_lock);
-
-        do {
-                clear_thread_flag(TIF_SIGPENDING);
-                rc = sys_wait4(-1, NULL, __WALL, NULL);
-        } while (rc != -ECHILD);
-
-
-        /* Child reaper for the pid namespace is going away */
-        pid_ns->child_reaper = NULL;
-        return;
-}
-
 /*
  * The pid hash table is scaled according to the amount of memory in the
  * machine.  From a minimum of 16 slots up to 4096 slots at one gigabyte or
@@ -694,9 +519,6 @@ void __init pidmap_init(void)
         set_bit(0, init_pid_ns.pidmap[0].page);
         atomic_dec(&init_pid_ns.pidmap[0].nr_free);
 
-        init_pid_ns.pid_cachep = create_pid_cachep(1);
-        if (init_pid_ns.pid_cachep == NULL)
-                panic("Can't create pid_1 cachep\n");
-
-        pid_ns_cachep = KMEM_CACHE(pid_namespace, SLAB_PANIC);
+        init_pid_ns.pid_cachep = KMEM_CACHE(pid,
+                        SLAB_HWCACHE_ALIGN | SLAB_PANIC);
 }