C++ request_module函数代码示例

static int sound_mixer_ioctl(int mixdev, unsigned int cmd, caddr_t arg)
{
 	if (mixdev < 0 || mixdev >= MAX_MIXER_DEV)
 		return -ENXIO;
 	/* Try to load the mixer... */
 	if (mixer_devs[mixdev] == NULL) {
 		char modname[20];
 		sprintf(modname, "mixer%d", mixdev);
 		request_module(modname);
 	}
 	if (mixdev >= num_mixers || !mixer_devs[mixdev])
 		return -ENXIO;
	if (cmd == SOUND_MIXER_INFO)
		return get_mixer_info(mixdev, arg);
	if (cmd == SOUND_OLD_MIXER_INFO)
		return get_old_mixer_info(mixdev, arg);
	if (_SIOC_DIR(cmd) & _SIOC_WRITE)
		mixer_devs[mixdev]->modify_counter++;
	if (!mixer_devs[mixdev]->ioctl)
		return -EINVAL;
	return mixer_devs[mixdev]->ioctl(mixdev, cmd, arg);
}

int cx23885_ir_init(struct cx23885_dev *dev)
{
	switch (dev->board) {
	case CX23885_BOARD_HAUPPAUGE_HVR1250:
	case CX23885_BOARD_HAUPPAUGE_HVR1500:
	case CX23885_BOARD_HAUPPAUGE_HVR1500Q:
	case CX23885_BOARD_HAUPPAUGE_HVR1800:
	case CX23885_BOARD_HAUPPAUGE_HVR1200:
	case CX23885_BOARD_HAUPPAUGE_HVR1400:
	case CX23885_BOARD_HAUPPAUGE_HVR1270:
	case CX23885_BOARD_HAUPPAUGE_HVR1275:
	case CX23885_BOARD_HAUPPAUGE_HVR1255:
	case CX23885_BOARD_HAUPPAUGE_HVR1210:
		/* FIXME: Implement me */
		break;
	case CX23885_BOARD_DVICO_FUSIONHDTV_DVB_T_DUAL_EXP:
		request_module("ir-kbd-i2c");
		break;
	}

	return 0;
}

/* exported */
int __init snd_pmac_daca_init(struct snd_pmac *chip)
{
	int i, err;
	struct pmac_daca *mix;

#ifdef CONFIG_KMOD
	request_module("i2c-powermac");
#endif /* CONFIG_KMOD */

	mix = kzalloc(sizeof(*mix), GFP_KERNEL);
	if (! mix)
		return -ENOMEM;
	chip->mixer_data = mix;
	chip->mixer_free = daca_cleanup;
	mix->amp_on = 1; /* default on */

	mix->i2c.addr = DACA_I2C_ADDR;
	mix->i2c.init_client = daca_init_client;
	mix->i2c.name = "DACA";
	if ((err = snd_pmac_keywest_init(&mix->i2c)) < 0)
		return err;

	/*
	 * build mixers
	 */
	strcpy(chip->card->mixername, "PowerMac DACA");

	for (i = 0; i < ARRAY_SIZE(daca_mixers); i++) {
		if ((err = snd_ctl_add(chip->card, snd_ctl_new1(&daca_mixers[i], chip))) < 0)
			return err;
	}

#ifdef CONFIG_PM
	chip->resume = daca_resume;
#endif

	return 0;
}

static int phone_open(struct inode *inode, struct file *file)
{
	unsigned int minor = iminor(inode);
	int err = 0;
	struct phone_device *p;
	const struct file_operations *old_fops, *new_fops = NULL;

	if (minor >= PHONE_NUM_DEVICES)
		return -ENODEV;

	mutex_lock(&phone_lock);
	p = phone_device[minor];
	if (p)
		new_fops = fops_get(p->f_op);
	if (!new_fops) {
		mutex_unlock(&phone_lock);
		request_module("char-major-%d-%d", PHONE_MAJOR, minor);
		mutex_lock(&phone_lock);
		p = phone_device[minor];
		if (p == NULL || (new_fops = fops_get(p->f_op)) == NULL)
		{
			err=-ENODEV;
			goto end;
		}
	}
	old_fops = file->f_op;
	file->f_op = new_fops;
	if (p->open)
		err = p->open(p, file);	
	if (err) {
		fops_put(file->f_op);
		file->f_op = fops_get(old_fops);
	}
	fops_put(old_fops);
end:
	mutex_unlock(&phone_lock);
	return err;
}

static void vfio_platform_get_reset(struct vfio_platform_device *vdev,
				    struct device *dev)
{
	const char *compat;
	int (*reset)(struct vfio_platform_device *);
	int ret, i;

	ret = device_property_read_string(dev, "compatible", &compat);
	if (ret)
		return;

	for (i = 0 ; i < ARRAY_SIZE(reset_lookup_table); i++) {
		if (!strcmp(reset_lookup_table[i].compat, compat)) {
			request_module(reset_lookup_table[i].module_name);
			reset = __symbol_get(
				reset_lookup_table[i].reset_function_name);
			if (reset) {
				vdev->reset = reset;
				return;
			}
		}
	}
}

static int pppox_create(struct net *net, struct socket *sock, int protocol)
{
	int rc = -EPROTOTYPE;

	if (net != &init_net)
		return -EAFNOSUPPORT;

	if (protocol < 0 || protocol > PX_MAX_PROTO)
		goto out;

	rc = -EPROTONOSUPPORT;
	if (!pppox_protos[protocol])
		request_module("pppox-proto-%d", protocol);
	if (!pppox_protos[protocol] ||
	    !try_module_get(pppox_protos[protocol]->owner))
		goto out;

	rc = pppox_protos[protocol]->create(net, sock);

	module_put(pppox_protos[protocol]->owner);
out:
	return rc;
}

/**
 * Register available hash functions
 *
 * \retval		0
 */
int cfs_crypto_register(void)
{
	request_module("crc32c");

	adler32 = cfs_crypto_adler32_register();

#ifdef HAVE_CRC32
	crc32 = cfs_crypto_crc32_register();
#endif
#ifdef HAVE_PCLMULQDQ
#ifdef NEED_CRC32_ACCEL
	crc32_pclmul = cfs_crypto_crc32_pclmul_register();
#endif
#ifdef NEED_CRC32C_ACCEL
	crc32c_pclmul = cfs_crypto_crc32c_pclmul_register();
#endif
#endif /* HAVE_PCLMULQDQ */

	/* check all algorithms and do performance test */
	cfs_crypto_test_hashes();

	return 0;
}

struct v4l2_subdev *v4l2_spi_new_subdev(struct v4l2_device *v4l2_dev,
		struct spi_master *master, struct spi_board_info *info)
{
	struct v4l2_subdev *sd = NULL;
	struct spi_device *spi = NULL;

	BUG_ON(!v4l2_dev);

	if (info->modalias)
		request_module(info->modalias);

	spi = spi_new_device(master, info);

	if (spi == NULL || spi->dev.driver == NULL)
		goto error;

	if (!try_module_get(spi->dev.driver->owner))
		goto error;

	sd = spi_get_drvdata(spi);

	/* Register with the v4l2_device which increases the module's
	   use count as well. */
	if (v4l2_device_register_subdev(v4l2_dev, sd))
		sd = NULL;

	/* Decrease the module use count to match the first try_module_get. */
	module_put(spi->dev.driver->owner);

error:
	/* If we have a client but no subdev, then something went wrong and
	   we must unregister the client. */
	if (spi && sd == NULL)
		spi_unregister_device(spi);

	return sd;
}

/**
 *	ovs_vport_add - add vport device (for kernel callers)
 *
 * @parms: Information about new vport.
 *
 * Creates a new vport with the specified configuration (which is dependent on
 * device type).  ovs_mutex must be held.
 */
struct vport *ovs_vport_add(const struct vport_parms *parms)
{
	struct vport_ops *ops;
	struct vport *vport;

	ops = ovs_vport_lookup(parms);
	if (ops) {
		struct hlist_head *bucket;

		if (!try_module_get(ops->owner))
			return ERR_PTR(-EAFNOSUPPORT);

		vport = ops->create(parms);
		if (IS_ERR(vport)) {
			module_put(ops->owner);
			return vport;
		}

		bucket = hash_bucket(ovs_dp_get_net(vport->dp),
				     ovs_vport_name(vport));
		hlist_add_head_rcu(&vport->hash_node, bucket);
		return vport;
	}

	/* Unlock to attempt module load and return -EAGAIN if load
	 * was successful as we need to restart the port addition
	 * workflow.
	 */
	ovs_unlock();
	request_module("vport-type-%d", parms->type);
	ovs_lock();

	if (!ovs_vport_lookup(parms))
		return ERR_PTR(-EAFNOSUPPORT);
	else
		return ERR_PTR(-EAGAIN);
}

/*
 * Try to set the server's pnfs module to the pnfs layout type specified by id.
 * Currently only one pNFS layout driver per filesystem is supported.
 *
 * @id layout type. Zero (illegal layout type) indicates pNFS not in use.
 */
void
set_pnfs_layoutdriver(struct nfs_server *server, u32 id)
{
    struct pnfs_layoutdriver_type *ld_type = NULL;

    if (id == 0)
        goto out_no_driver;
    if (!(server->nfs_client->cl_exchange_flags &
            (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) {
        printk(KERN_ERR "%s: id %u cl_exchange_flags 0x%x\n", __func__,
               id, server->nfs_client->cl_exchange_flags);
        goto out_no_driver;
    }
    ld_type = find_pnfs_driver(id);
    if (!ld_type) {
        request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id);
        ld_type = find_pnfs_driver(id);
        if (!ld_type) {
            dprintk("%s: No pNFS module found for %u.\n",
                    __func__, id);
            goto out_no_driver;
        }
    }
    if (!try_module_get(ld_type->owner)) {
        dprintk("%s: Could not grab reference on module\n", __func__);
        goto out_no_driver;
    }
    server->pnfs_curr_ld = ld_type;

    dprintk("%s: pNFS module for %u set\n", __func__, id);
    return;

out_no_driver:
    dprintk("%s: Using NFSv4 I/O\n", __func__);
    server->pnfs_curr_ld = NULL;
}

int parse_mtd_partitions(struct mtd_info *master, const char **types,
			 struct mtd_partition **pparts, unsigned long origin)
{
	struct mtd_part_parser *parser;
	int ret = 0;

	for ( ; ret <= 0 && *types; types++) {
		parser = get_partition_parser(*types);
		if (!parser && !request_module("%s", *types))
				parser = get_partition_parser(*types);
		if (!parser) {
			printk(KERN_NOTICE "%s partition parsing not available\n",
			       *types);
			continue;
		}
		ret = (*parser->parse_fn)(master, pparts, origin);
		if (ret > 0) {
			printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
			       ret, parser->name, master->name);
		}
		put_partition_parser(parser);
	}
	return ret;
}

/* Detect all FC Arbitrated Loops attached to the machine.
   fc4 module has done all the work for us... */
int __init fcal_detect(Scsi_Host_Template *tpnt)
{
	int nfcals = 0;
	fc_channel *fc;
	int fcalcount;
	int i;

	tpnt->proc_name = "fcal";
	fcalcount = 0;
	for_each_online_fc_channel(fc)
		if (fc->posmap)
			fcalcount++;
	FCALND(("%d channels online\n", fcalcount))
	if (!fcalcount) {
#if defined(MODULE) && defined(CONFIG_FC4_SOCAL_MODULE) && defined(CONFIG_KMOD)
		request_module("socal");
		
		for_each_online_fc_channel(fc)
			if (fc->posmap)
				fcalcount++;
		if (!fcalcount)
#endif
			return 0;
	}

struct v4l2_subdev *v4l2_i2c_new_subdev_board(struct v4l2_device *v4l2_dev,
		struct i2c_adapter *adapter, struct i2c_board_info *info,
		const unsigned short *probe_addrs)
{
	struct v4l2_subdev *sd = NULL;
	struct i2c_client *client;

	BUG_ON(!v4l2_dev);

	request_module(I2C_MODULE_PREFIX "%s", info->type);

	
	if (info->addr == 0 && probe_addrs)
		client = i2c_new_probed_device(adapter, info, probe_addrs,
					       NULL);
	else
		client = i2c_new_device(adapter, info);

	if (client == NULL || client->driver == NULL)
		goto error;

	
	if (!try_module_get(client->driver->driver.owner))
		goto error;
	sd = i2c_get_clientdata(client);

	if (v4l2_device_register_subdev(v4l2_dev, sd))
		sd = NULL;
	
	module_put(client->driver->driver.owner);

error:
	if (client && sd == NULL)
		i2c_unregister_device(client);
	return sd;
}

//.........这里部分代码省略.........
						&pinnacle_80e_dvb_config);
			if (!dvb->fe[0]) {
				result = -EINVAL;
				goto out_free;
			}
		}
		break;
	case EM28178_BOARD_PCTV_461E:
		{
			/* demod I2C adapter */
			struct i2c_adapter *i2c_adapter;
			struct i2c_client *client;
			struct i2c_board_info info;
			struct m88ts2022_config m88ts2022_config = {
				.clock = 27000000,
			};
			memset(&info, 0, sizeof(struct i2c_board_info));

			/* attach demod */
			dvb->fe[0] = dvb_attach(m88ds3103_attach,
					&pctv_461e_m88ds3103_config,
					&dev->i2c_adap[dev->def_i2c_bus],
					&i2c_adapter);
			if (dvb->fe[0] == NULL) {
				result = -ENODEV;
				goto out_free;
			}

			/* attach tuner */
			m88ts2022_config.fe = dvb->fe[0];
			strlcpy(info.type, "m88ts2022", I2C_NAME_SIZE);
			info.addr = 0x60;
			info.platform_data = &m88ts2022_config;
			request_module("m88ts2022");
			client = i2c_new_device(i2c_adapter, &info);
			if (client == NULL || client->dev.driver == NULL) {
				dvb_frontend_detach(dvb->fe[0]);
				result = -ENODEV;
				goto out_free;
			}

			if (!try_module_get(client->dev.driver->owner)) {
				i2c_unregister_device(client);
				dvb_frontend_detach(dvb->fe[0]);
				result = -ENODEV;
				goto out_free;
			}

			/* delegate signal strength measurement to tuner */
			dvb->fe[0]->ops.read_signal_strength =
					dvb->fe[0]->ops.tuner_ops.get_rf_strength;

			/* attach SEC */
			if (!dvb_attach(a8293_attach, dvb->fe[0],
					&dev->i2c_adap[dev->def_i2c_bus],
					&em28xx_a8293_config)) {
				module_put(client->dev.driver->owner);
				i2c_unregister_device(client);
				dvb_frontend_detach(dvb->fe[0]);
				result = -ENODEV;
				goto out_free;
			}

			dvb->i2c_client_tuner = client;
		}
		break;

/* Process one complete nfnetlink message. */
static int nfnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
{
	struct net *net = sock_net(skb->sk);
	const struct nfnl_callback *nc;
	const struct nfnetlink_subsystem *ss;
	int type, err;

	/* All the messages must at least contain nfgenmsg */
	if (nlmsg_len(nlh) < sizeof(struct nfgenmsg))
		return 0;

	type = nlh->nlmsg_type;
replay:
	rcu_read_lock();
	ss = nfnetlink_get_subsys(type);
	if (!ss) {
#ifdef CONFIG_MODULES
		rcu_read_unlock();
		request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type));
		rcu_read_lock();
		ss = nfnetlink_get_subsys(type);
		if (!ss)
#endif
		{
			rcu_read_unlock();
			return -EINVAL;
		}
	}

	nc = nfnetlink_find_client(type, ss);
	if (!nc) {
		rcu_read_unlock();
		return -EINVAL;
	}

	{
		int min_len = nlmsg_total_size(sizeof(struct nfgenmsg));
		u_int8_t cb_id = NFNL_MSG_TYPE(nlh->nlmsg_type);
		struct nlattr *cda[ss->cb[cb_id].attr_count + 1];
		struct nlattr *attr = (void *)nlh + min_len;
		int attrlen = nlh->nlmsg_len - min_len;
		__u8 subsys_id = NFNL_SUBSYS_ID(type);

		err = nla_parse(cda, ss->cb[cb_id].attr_count,
				attr, attrlen, ss->cb[cb_id].policy);
		if (err < 0) {
			rcu_read_unlock();
			return err;
		}

		if (nc->call_rcu) {
			err = nc->call_rcu(net->nfnl, skb, nlh,
					   (const struct nlattr **)cda);
			rcu_read_unlock();
		} else {
			rcu_read_unlock();
			nfnl_lock(subsys_id);
			if (rcu_dereference_protected(table[subsys_id].subsys,
				lockdep_is_held(&table[subsys_id].mutex)) != ss ||
			    nfnetlink_find_client(type, ss) != nc)
				err = -EAGAIN;
			else if (nc->call)
				err = nc->call(net->nfnl, skb, nlh,
						   (const struct nlattr **)cda);
			else
				err = -EINVAL;
			nfnl_unlock(subsys_id);
		}
		if (err == -EAGAIN)
			goto replay;
		return err;
	}
}