X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=kernel%2Fpid.c;h=20d59fa2d493c7a20b83ff151745e38a847e0366;hb=f6837bfa6506892e889ec79d8ab29931b4468826;hp=4b17acdb862f5b1e917b492bc9118d895a27c0a7;hpb=b461cc03828c743aed6b3855b9ab0d39a9d54ec5;p=linux-2.6 diff --git a/kernel/pid.c b/kernel/pid.c index 4b17acdb86..20d59fa2d4 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -18,6 +18,12 @@ * 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 , OpenVZ, SWsoft Inc. + * (C) 2007 Sukadev Bhattiprolu , IBM + * Many thanks to Oleg Nesterov for comments and help + * */ #include @@ -28,6 +34,7 @@ #include #include #include +#include #define pid_hashfn(nr, ns) \ hash_long((unsigned long)nr + (unsigned long)ns, pidhash_shift) @@ -104,10 +111,11 @@ EXPORT_SYMBOL(is_container_init); 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 upid *upid) { - struct pidmap *map = pid_ns->pidmap + pid / BITS_PER_PAGE; - int offset = pid & BITS_PER_PAGE_MASK; + int nr = upid->nr; + struct pidmap *map = upid->ns->pidmap + nr / BITS_PER_PAGE; + int offset = nr & BITS_PER_PAGE_MASK; clear_bit(offset, map->page); atomic_inc(&map->nr_free); @@ -173,7 +181,7 @@ 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; @@ -191,7 +199,7 @@ static int next_pidmap(struct pid_namespace *pid_ns, int last) return -1; } -fastcall void put_pid(struct pid *pid) +void put_pid(struct pid *pid) { struct pid_namespace *ns; @@ -213,7 +221,7 @@ static void delayed_put_pid(struct rcu_head *rhp) 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; @@ -225,7 +233,7 @@ fastcall void free_pid(struct pid *pid) spin_unlock_irqrestore(&pidmap_lock, flags); for (i = 0; i <= pid->level; i++) - free_pidmap(pid->numbers[i].ns, pid->numbers[i].nr); + free_pidmap(pid->numbers + i); call_rcu(&pid->rcu, delayed_put_pid); } @@ -255,7 +263,6 @@ struct pid *alloc_pid(struct pid_namespace *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]); @@ -272,15 +279,15 @@ out: return pid; out_free: - for (i++; i <= ns->level; i++) - free_pidmap(pid->numbers[i].ns, pid->numbers[i].nr); + while (++i <= ns->level) + free_pidmap(pid->numbers + i); kmem_cache_free(ns->pid_cachep, pid); pid = NULL; goto out; } -struct pid * fastcall find_pid_ns(int nr, struct pid_namespace *ns) +struct pid *find_pid_ns(int nr, struct pid_namespace *ns) { struct hlist_node *elem; struct upid *pnr; @@ -295,10 +302,22 @@ struct pid * fastcall find_pid_ns(int nr, struct pid_namespace *ns) } 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, +void attach_pid(struct task_struct *task, enum pid_type type, struct pid *pid) { struct pid_link *link; @@ -306,11 +325,10 @@ int fastcall attach_pid(struct task_struct *task, enum pid_type type, link = &task->pids[type]; link->pid = pid; hlist_add_head_rcu(&link->node, &pid->tasks[type]); - - return 0; } -void fastcall detach_pid(struct task_struct *task, enum pid_type type) +static void __change_pid(struct task_struct *task, enum pid_type type, + struct pid *new) { struct pid_link *link; struct pid *pid; @@ -320,7 +338,7 @@ void fastcall detach_pid(struct task_struct *task, enum pid_type type) pid = link->pid; hlist_del_rcu(&link->node); - link->pid = NULL; + link->pid = new; for (tmp = PIDTYPE_MAX; --tmp >= 0; ) if (!hlist_empty(&pid->tasks[tmp])) @@ -329,16 +347,27 @@ void fastcall detach_pid(struct task_struct *task, enum pid_type type) free_pid(pid); } +void detach_pid(struct task_struct *task, enum pid_type type) +{ + __change_pid(task, type, NULL); +} + +void change_pid(struct task_struct *task, enum pid_type type, + struct pid *pid) +{ + __change_pid(task, type, pid); + attach_pid(task, type, 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; hlist_replace_rcu(&old->pids[type].node, &new->pids[type].node); - 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) { @@ -349,6 +378,7 @@ struct task_struct * fastcall pid_task(struct pid *pid, enum pid_type type) } return result; } +EXPORT_SYMBOL(pid_task); /* * Must be called under rcu_read_lock() or with tasklist_lock read-held. @@ -361,6 +391,19 @@ struct task_struct *find_task_by_pid_type_ns(int type, int nr, EXPORT_SYMBOL(find_task_by_pid_type_ns); +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) { struct pid *pid; @@ -370,7 +413,7 @@ 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(); @@ -405,6 +448,36 @@ pid_t pid_nr_ns(struct pid *pid, struct pid_namespace *ns) 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. * @@ -425,71 +498,6 @@ 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, - /* 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 @@ -522,7 +530,6 @@ 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"); + init_pid_ns.pid_cachep = KMEM_CACHE(pid, + SLAB_HWCACHE_ALIGN | SLAB_PANIC); }