C++ (Cpp) _kddm_grab_object_no_ft Examples

Example #1

/**
 * @author Pascal Gallard
 */
static struct task_kddm_object *task_writelock(pid_t pid, int nested)
{
	struct task_kddm_object *obj;

	/* Filter well known cases of no task kddm object. */
	if (!(pid & GLOBAL_PID_MASK))
		return NULL;

	obj = _kddm_grab_object_no_ft(task_kddm_set, pid);
	if (likely(obj)) {
		if (!nested)
			down_write(&obj->sem);
		else
			down_write_nested(&obj->sem, SINGLE_DEPTH_NESTING);
		if (obj->write_locked == 2) {
			/* Dying object */
			up_write(&obj->sem);
			_kddm_put_object(task_kddm_set, pid);
			return NULL;
		}
		/* Marker for unlock. Dirty but temporary. */
		obj->write_locked = 1;
	}

	return obj;
}

Example #2

File: shm_handler.c Project: jeanparpaillon/kerrighed-kernel

static struct kern_ipc_perm *kcb_ipc_shm_lock(struct ipc_ids *ids, int id)
{
	shmid_object_t *shp_object;
	struct shmid_kernel *shp;
	int index;

	rcu_read_lock();

	index = ipcid_to_idx(id);

	shp_object = _kddm_grab_object_no_ft(ids->krgops->data_kddm_set, index);

	if (!shp_object)
		goto error;

	shp = shp_object->local_shp;

	BUG_ON(!shp);

	mutex_lock(&shp->shm_perm.mutex);

	if (shp->shm_perm.deleted) {
		mutex_unlock(&shp->shm_perm.mutex);
		goto error;
	}

	return &(shp->shm_perm);

error:
	_kddm_put_object(ids->krgops->data_kddm_set, index);
	rcu_read_unlock();

	return ERR_PTR(-EINVAL);
}

Example #3

struct pid *krg_get_pid(int nr)
{
	struct pid_kddm_object *obj;
	struct pid *pid;

	rcu_read_lock();
	pid = find_kpid(nr);
	rcu_read_unlock();
	/*
	 * No need to get a reference on pid since we know that it is used on
	 * another node: nobody will free it for the moment.
	 */

	if (!pid)
		return no_pid(nr);

	spin_lock(&pid_kddm_lock);
	obj = pid->kddm_obj;
	BUG_ON(!obj);
	BUG_ON(obj->pid != pid);

	if (likely(obj->active)) {
		obj->attach_pending++;
		spin_unlock(&pid_kddm_lock);
		return pid;
	}
	/* Slow path: we must grab the kddm object. */
	spin_unlock(&pid_kddm_lock);

	obj = _kddm_grab_object_no_ft(pid_kddm_set, nr);
	if (IS_ERR(obj))
		return NULL;
	BUG_ON(obj != pid->kddm_obj);
	BUG_ON(obj->pid != pid);

	spin_lock(&pid_kddm_lock);
	__get_pid(obj);
	spin_unlock(&pid_kddm_lock);

	_kddm_put_object(pid_kddm_set, nr);

	return pid;
}

Example #4

static struct pid *no_pid(int nr)
{
	struct pid_namespace *ns;
	struct pid_kddm_object *obj;
	struct pid *pid;

	obj = _kddm_grab_object_no_ft(pid_kddm_set, nr);
	if (IS_ERR(obj))
		return NULL;
	BUG_ON(!obj);

	spin_lock(&pid_kddm_lock);
	rcu_read_lock();
	pid = find_kpid(nr); /* Double check once locked */
	rcu_read_unlock();
	/*
	 * No need to get a reference on pid since we know that it is used on
	 * another node: nobody will free it for the moment.
	 */

	if (!pid) {
		ns = find_get_krg_pid_ns();
		pid = __alloc_pid(ns, &nr);
		put_pid_ns(ns);
		if (!pid)
			goto out_unlock;
		obj->pid = pid;
		pid->kddm_obj = obj;
	}
	BUG_ON(pid->kddm_obj != obj);

	__get_pid(obj);

out_unlock:
	spin_unlock(&pid_kddm_lock);
	_kddm_put_object(pid_kddm_set, nr);

	return pid;
}

Example #5

File: shm_handler.c Project: jeanparpaillon/kerrighed-kernel

void krg_ipc_shm_destroy(struct ipc_namespace *ns, struct shmid_kernel *shp)
{
	struct kddm_set *mm_set;
	int index;
	key_t key;

	index = ipcid_to_idx(shp->shm_perm.id);
	key = shp->shm_perm.key;

	mm_set = shp->shm_file->f_dentry->d_inode->i_mapping->kddm_set;

	if (key != IPC_PRIVATE) {
		_kddm_grab_object_no_ft(shm_ids(ns).krgops->key_kddm_set, key);
		_kddm_remove_frozen_object(shm_ids(ns).krgops->key_kddm_set, key);
	}

	local_shm_unlock(shp);

	_kddm_remove_frozen_object(shm_ids(ns).krgops->data_kddm_set, index);
	_destroy_kddm_set(mm_set);

	krg_ipc_rmid(&shm_ids(ns), index);
}