* allocation scenario when all but one out of 1 million PIDs possible are
* allocated already: the scanning of 32 list entries and at most PAGE_SIZE
* bytes. The typical fastpath is a single successful setbit. Freeing is O(1).
+ *
+ * Pid namespaces:
+ * (C) 2007 Pavel Emelyanov <xemul@openvz.org>, OpenVZ, SWsoft Inc.
+ * (C) 2007 Sukadev Bhattiprolu <sukadev@us.ibm.com>, IBM
+ * Many thanks to Oleg Nesterov for comments and help
+ *
*/
#include <linux/mm.h>
#include <linux/hash.h>
#include <linux/pid_namespace.h>
#include <linux/init_task.h>
+#include <linux/syscalls.h>
#define pid_hashfn(nr, ns) \
hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift)
.level = 0,
.child_reaper = &init_task,
};
+EXPORT_SYMBOL_GPL(init_pid_ns);
-int is_global_init(struct task_struct *tsk)
+int is_container_init(struct task_struct *tsk)
{
- return tsk == init_pid_ns.child_reaper;
+ int ret = 0;
+ struct pid *pid;
+
+ rcu_read_lock();
+ pid = task_pid(tsk);
+ if (pid != NULL && pid->numbers[pid->level].nr == 1)
+ ret = 1;
+ rcu_read_unlock();
+
+ return ret;
}
+EXPORT_SYMBOL(is_container_init);
/*
* Note: disable interrupts while the pidmap_lock is held as an
static __cacheline_aligned_in_smp DEFINE_SPINLOCK(pidmap_lock);
-static fastcall void free_pidmap(struct pid_namespace *pid_ns, int pid)
+static void free_pidmap(struct pid_namespace *pid_ns, int pid)
{
struct pidmap *map = pid_ns->pidmap + pid / BITS_PER_PAGE;
int offset = pid & BITS_PER_PAGE_MASK;
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;
return -1;
}
-fastcall void put_pid(struct pid *pid)
+void put_pid(struct pid *pid)
{
struct pid_namespace *ns;
if ((atomic_read(&pid->count) == 1) ||
atomic_dec_and_test(&pid->count)) {
kmem_cache_free(ns->pid_cachep, pid);
- if (ns != &init_pid_ns)
- put_pid_ns(ns);
+ put_pid_ns(ns);
}
}
EXPORT_SYMBOL_GPL(put_pid);
put_pid(pid);
}
-fastcall void free_pid(struct pid *pid)
+void free_pid(struct pid *pid)
{
/* We can be called with write_lock_irq(&tasklist_lock) held */
int i;
unsigned long flags;
spin_lock_irqsave(&pidmap_lock, flags);
- hlist_del_rcu(&pid->pid_chain);
+ for (i = 0; i <= pid->level; i++)
+ hlist_del_rcu(&pid->numbers[i].pid_chain);
spin_unlock_irqrestore(&pidmap_lock, flags);
for (i = 0; i <= pid->level; i++)
enum pid_type type;
int i, nr;
struct pid_namespace *tmp;
+ struct upid *upid;
pid = kmem_cache_alloc(ns->pid_cachep, GFP_KERNEL);
if (!pid)
tmp = tmp->parent;
}
- if (ns != &init_pid_ns)
- get_pid_ns(ns);
-
+ get_pid_ns(ns);
pid->level = ns->level;
- pid->nr = pid->numbers[0].nr;
atomic_set(&pid->count, 1);
for (type = 0; type < PIDTYPE_MAX; ++type)
INIT_HLIST_HEAD(&pid->tasks[type]);
spin_lock_irq(&pidmap_lock);
- hlist_add_head_rcu(&pid->pid_chain, &pid_hash[pid_hashfn(pid->nr, ns)]);
+ for (i = ns->level; i >= 0; i--) {
+ upid = &pid->numbers[i];
+ hlist_add_head_rcu(&upid->pid_chain,
+ &pid_hash[pid_hashfn(upid->nr, upid->ns)]);
+ }
spin_unlock_irq(&pidmap_lock);
out:
goto out;
}
-struct pid * fastcall find_pid(int nr)
+struct pid *find_pid_ns(int nr, struct pid_namespace *ns)
{
struct hlist_node *elem;
- struct pid *pid;
+ struct upid *pnr;
+
+ hlist_for_each_entry_rcu(pnr, elem,
+ &pid_hash[pid_hashfn(nr, ns)], pid_chain)
+ if (pnr->nr == nr && pnr->ns == ns)
+ return container_of(pnr, struct pid,
+ numbers[ns->level]);
- hlist_for_each_entry_rcu(pid, elem,
- &pid_hash[pid_hashfn(nr, &init_pid_ns)], pid_chain) {
- if (pid->nr == nr)
- return pid;
- }
return NULL;
}
+EXPORT_SYMBOL_GPL(find_pid_ns);
+
+struct pid *find_vpid(int nr)
+{
+ return find_pid_ns(nr, current->nsproxy->pid_ns);
+}
+EXPORT_SYMBOL_GPL(find_vpid);
+
+struct pid *find_pid(int nr)
+{
+ return find_pid_ns(nr, &init_pid_ns);
+}
EXPORT_SYMBOL_GPL(find_pid);
/*
* attach_pid() must be called with the tasklist_lock write-held.
*/
-int fastcall attach_pid(struct task_struct *task, enum pid_type type,
+int attach_pid(struct task_struct *task, enum pid_type type,
struct pid *pid)
{
struct pid_link *link;
return 0;
}
-void fastcall detach_pid(struct task_struct *task, enum pid_type type)
+void detach_pid(struct task_struct *task, enum pid_type type)
{
struct pid_link *link;
struct pid *pid;
}
/* transfer_pid is an optimization of attach_pid(new), detach_pid(old) */
-void fastcall transfer_pid(struct task_struct *old, struct task_struct *new,
+void transfer_pid(struct task_struct *old, struct task_struct *new,
enum pid_type type)
{
new->pids[type].pid = old->pids[type].pid;
old->pids[type].pid = NULL;
}
-struct task_struct * fastcall pid_task(struct pid *pid, enum pid_type type)
+struct task_struct *pid_task(struct pid *pid, enum pid_type type)
{
struct task_struct *result = NULL;
if (pid) {
}
return result;
}
+EXPORT_SYMBOL(pid_task);
/*
* Must be called under rcu_read_lock() or with tasklist_lock read-held.
*/
-struct task_struct *find_task_by_pid_type(int type, int nr)
+struct task_struct *find_task_by_pid_type_ns(int type, int nr,
+ struct pid_namespace *ns)
{
- return pid_task(find_pid(nr), type);
+ return pid_task(find_pid_ns(nr, ns), type);
}
-EXPORT_SYMBOL(find_task_by_pid_type);
+EXPORT_SYMBOL(find_task_by_pid_type_ns);
+
+struct task_struct *find_task_by_pid(pid_t nr)
+{
+ return find_task_by_pid_type_ns(PIDTYPE_PID, nr, &init_pid_ns);
+}
+EXPORT_SYMBOL(find_task_by_pid);
+
+struct task_struct *find_task_by_vpid(pid_t vnr)
+{
+ return find_task_by_pid_type_ns(PIDTYPE_PID, vnr,
+ current->nsproxy->pid_ns);
+}
+EXPORT_SYMBOL(find_task_by_vpid);
+
+struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns)
+{
+ return find_task_by_pid_type_ns(PIDTYPE_PID, nr, ns);
+}
+EXPORT_SYMBOL(find_task_by_pid_ns);
struct pid *get_task_pid(struct task_struct *task, enum pid_type type)
{
return pid;
}
-struct task_struct *fastcall get_pid_task(struct pid *pid, enum pid_type type)
+struct task_struct *get_pid_task(struct pid *pid, enum pid_type type)
{
struct task_struct *result;
rcu_read_lock();
struct pid *pid;
rcu_read_lock();
- pid = get_pid(find_pid(nr));
+ pid = get_pid(find_vpid(nr));
rcu_read_unlock();
return pid;
return nr;
}
+pid_t pid_vnr(struct pid *pid)
+{
+ return pid_nr_ns(pid, current->nsproxy->pid_ns);
+}
+EXPORT_SYMBOL_GPL(pid_vnr);
+
+pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
+{
+ return pid_nr_ns(task_pid(tsk), ns);
+}
+EXPORT_SYMBOL(task_pid_nr_ns);
+
+pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
+{
+ return pid_nr_ns(task_tgid(tsk), ns);
+}
+EXPORT_SYMBOL(task_tgid_nr_ns);
+
+pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
+{
+ return pid_nr_ns(task_pgrp(tsk), ns);
+}
+EXPORT_SYMBOL(task_pgrp_nr_ns);
+
+pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
+{
+ return pid_nr_ns(task_session(tsk), ns);
+}
+EXPORT_SYMBOL(task_session_nr_ns);
+
/*
* Used by proc to find the first pid that is greater then or equal to nr.
*
* If there is a pid at nr this function is exactly the same as find_pid.
*/
-struct pid *find_ge_pid(int nr)
+struct pid *find_ge_pid(int nr, struct pid_namespace *ns)
{
struct pid *pid;
do {
- pid = find_pid(nr);
+ pid = find_pid_ns(nr, ns);
if (pid)
break;
- nr = next_pidmap(task_active_pid_ns(current), nr);
+ nr = next_pidmap(ns, nr);
} while (nr > 0);
return pid;
}
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,
- /* FIXME add numerical ids here */
- sizeof(struct pid), 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;
-}
-
-struct pid_namespace *copy_pid_ns(unsigned long flags, struct pid_namespace *old_ns)
-{
- BUG_ON(!old_ns);
- get_pid_ns(old_ns);
- return old_ns;
-}
-
-void free_pid_ns(struct kref *kref)
-{
- struct pid_namespace *ns;
-
- ns = container_of(kref, struct pid_namespace, kref);
- kfree(ns);
-}
-
/*
* 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
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");
+ init_pid_ns.pid_cachep = KMEM_CACHE(pid,
+ SLAB_HWCACHE_ALIGN | SLAB_PANIC);
}