C++ devfs_unregister函数代码示例

/*
 * The cleanup function is used to handle initialization failures as well.
 * Thefore, it must be careful to work correctly even if some of the items
 * have not been initialized
 */
void scull_cleanup_module(void)
{
    int i;

#ifndef CONFIG_DEVFS_FS
    /* cleanup_module is never called if registering failed */
    unregister_chrdev(scull_major, "scull");
#endif

    scull_remove_proc();
    if (scull_devices) {
        for (i=0; i<scull_nr_devs; i++) {
            scull_trim(scull_devices+i);
            /* the following line is only used for devfs */
            devfs_unregister(scull_devices[i].handle);
        }
        kfree(scull_devices);
    }

    /* and call the cleanup functions for friend devices */
    scull_p_cleanup();
    scull_access_cleanup();

    /* once again, only for devfs */
    devfs_unregister(scull_devfs_dir);

}

/*
 * This is called by cleanup_module or on failure.
 * It is required to never fail, even if nothing was initialized first
 */
void scull_access_cleanup(void)
{
    struct scull_listitem *lptr, *prev;

    scull_trim(&scull_s_device); /* disallocate it */
    scull_trim(&scull_u_device); /* disallocate it */
    scull_trim(&scull_w_device); /* disallocate it */

    /* all the cloned devices */
    prev=NULL;
    for (lptr = scull_c_head; lptr; lptr = lptr->next) {
        scull_trim(&(lptr->device));
        if (prev) kfree(prev);
        prev=lptr;
    }
    if (prev) kfree(prev);
    scull_c_head = NULL; /* overkill: we're unloading anyways */

    /* remove devfs entry points */
    devfs_unregister(scull_s_device.handle);
    devfs_unregister(scull_u_device.handle);
    devfs_unregister(scull_w_device.handle);
    devfs_unregister(scull_priv_handle);

    return;
}

void lvm_fs_remove_vg(vg_t *vg_ptr) {
	int i;

	if (!vg_ptr)
		return;

	devfs_unregister(ch_devfs_handle[vg_ptr->vg_number]);
	ch_devfs_handle[vg_ptr->vg_number] = NULL;

	/* remove lv's */
	for(i = 0; i < vg_ptr->lv_max; i++)
		if(vg_ptr->lv[i]) lvm_fs_remove_lv(vg_ptr, vg_ptr->lv[i]);

	/* must not remove directory before leaf nodes */
	devfs_unregister(vg_devfs_handle[vg_ptr->vg_number]);
	vg_devfs_handle[vg_ptr->vg_number] = NULL;

	/* remove pv's */
	for(i = 0; i < vg_ptr->pv_max; i++)
		if(vg_ptr->pv[i]) lvm_fs_remove_pv(vg_ptr, vg_ptr->pv[i]);

	if(vg_ptr->vg_dir_pde) {
		remove_proc_entry(LVM_LV_SUBDIR, vg_ptr->vg_dir_pde);
		vg_ptr->lv_subdir_pde = NULL;

		remove_proc_entry(LVM_PV_SUBDIR, vg_ptr->vg_dir_pde);
		vg_ptr->pv_subdir_pde = NULL;

		remove_proc_entry("group", vg_ptr->vg_dir_pde);
		vg_ptr->vg_dir_pde = NULL;

		remove_proc_entry(vg_ptr->vg_name, lvm_proc_vg_subdir);
	}
}

static void mtd_notify_remove(struct mtd_info* mtd)
{
	if (!mtd)
		return;

	devfs_unregister(devfs_rw_handle[mtd->index]);
	devfs_unregister(devfs_ro_handle[mtd->index]);
}

static void __exit
gpio_exit(void)
{
int i;
	for (i = 0; i < ARRAYSIZE(gpio_file); i++)
		devfs_unregister(gpio_file[i].handle);
	devfs_unregister(gpio_dir);
	devfs_unregister_chrdev(gpio_major, "gpio");
	sb_detach(gpio_sbh);}

void __exit fpga_exit(void)
{

#ifdef CONFIG_DEVFS_FS	
	devfs_unregister(devfs_fpgaraw);
	devfs_unregister(devfs_fpga_dir);
#endif
	unregister_chrdev(fpgaMajor, DEVICE_NAME);
}

void __exit s3c2410_adc_exit(void)
{
#ifdef CONFIG_DEVFS_FS	
	devfs_unregister(devfs_adcraw);
	devfs_unregister(devfs_adc_dir);
#endif
	unregister_chrdev(adcMajor, DEVICE_NAME);

	free_irq(IRQ_ADC_DONE, NULL);
}

static void __exit s3c2410_kbd_exit(void)
{

#ifdef CONFIG_DEVFS_FS	
	devfs_unregister(devfs_kbdraw);
	devfs_unregister(devfs_kbd_dir);
#endif
	unregister_chrdev(kbdMajor, DEVICE_NAME);

	free_irq(IRQ_KBD, s3c2410_isr_kbd);
}

static void __exit s3c2410_ts_exit(void)
{
#ifdef CONFIG_DEVFS_FS	
	devfs_unregister(devfs_tsraw);
	devfs_unregister(devfs_ts_dir);
#endif	
	unregister_chrdev(tsMajor, DEVICE_NAME);
#ifdef CONFIG_PM
	pm_unregister(tsdev.pm_dev);
#endif
	free_irq(IRQ_ADC_DONE, s3c2410_isr_adc);
	free_irq(IRQ_TC, s3c2410_isr_tc);
}

static void devfs_unregister_card(struct em84xx *card)
{
#if LINUX_VERSION_CODE < KERNEL_VERSION(2,5,69)
    devfs_unregister(em8300_handle[0]);
    devfs_unregister(em8300_handle[1]);
    devfs_unregister(em8300_handle[2]);
    devfs_unregister(em8300_handle[3]);
#else
    devfs_remove("%s%d", REALMAGIC_DEVICE_NAME, 0);
    devfs_remove("%s%d", REALMAGIC_DEVICE_NAME, 1);
    devfs_remove("%s%d", REALMAGIC_DEVICE_NAME, 2);
    devfs_remove("%s%d", REALMAGIC_DEVICE_NAME, 3);
#endif
}

static void camera_disconnect(struct usb_device *dev, void *ptr)
{
	struct camera_state	*camera = (struct camera_state *) ptr;
	int			subminor = camera->subminor;

	down (&state_table_mutex);
	down (&camera->sem);

	devfs_unregister(camera->devfs); 

	/* If camera's not opened, we can clean up right away.
	 * Else apps see a disconnect on next I/O; the release cleans.
	 */
	if (!camera->buf) {
		minor_data [subminor] = NULL;
		kfree (camera);
		camera = NULL;
	} else
		camera->dev = NULL;

	info ("USB Camera #%d disconnected", subminor);
	usb_dec_dev_use (dev);

	if (camera != NULL)
		up (&camera->sem);
	up (&state_table_mutex);
}

static void
disconnect_scanner(struct usb_device *dev, void *ptr)
{
	struct scn_usb_data *scn = (struct scn_usb_data *) ptr;

	down (&scn_mutex);
	down (&(scn->sem));

	if(scn->intr_ep) {
		dbg("disconnect_scanner(%d): Unlinking IRQ URB", scn->scn_minor);
		usb_unlink_urb(&scn->scn_irq);
	}
        usb_driver_release_interface(&scanner_driver,
                &scn->scn_dev->actconfig->interface[scn->ifnum]);

	kfree(scn->ibuf);
	kfree(scn->obuf);

	dbg("disconnect_scanner: De-allocating minor:%d", scn->scn_minor);
	devfs_unregister(scn->devfs);
	p_scn_table[scn->scn_minor] = NULL;
	up (&(scn->sem));
	kfree (scn);
	up (&scn_mutex);
}

static void ipmi_smi_gone(int if_num)
{
	if (if_num > MAX_DEVICES)
		return;

	devfs_unregister(handles[if_num]);
}

/**
 *	skel_disconnect
 *
 *	Called by the usb core when the device is removed from the system.
 */
static void skel_disconnect(struct usb_device *udev, void *ptr)
{
	struct usb_skel *dev;
	int minor;

	dev = (struct usb_skel *)ptr;
	
	down (&minor_table_mutex);
	down (&dev->sem);
		
	minor = dev->minor;

	/* remove our devfs node */
	devfs_unregister(dev->devfs);

	/* if the device is not opened, then we clean up right now */
	if (!dev->open_count) {
		up (&dev->sem);
		skel_delete (dev);
	} else {
		dev->udev = NULL;
		up (&dev->sem);
	}

	info("USB Skeleton #%d now disconnected", minor);
	up (&minor_table_mutex);
}

int __init
init_module(void)
{  
    int rc;

    /* Get our definition */
    _gmodule = gmodule_get();
    if(!_gmodule) return -ENODEV;


    /* Register ourselves */
#ifdef GMODULE_CONFIG_DEVFS_FS
    devfs_handle = devfs_register(NULL, 
				  _gmodule->name, 
				  DEVFS_FL_NONE, 
				  _gmodule->major,
				  _gmodule->minor, 
				  S_IFCHR | S_IRUGO | S_IWUGO,
				  &_gmodule_fops, 
				  NULL);
    if(!devfs_handle) {
	printk(KERN_WARNING "%s: can't register device with devfs", 
	       _gmodule->name);
    }
    rc = 0;
#else
    rc = register_chrdev(_gmodule->major, 
			 _gmodule->name, 
			 &_gmodule_fops);
    if (rc < 0) {
	printk(KERN_WARNING "%s: can't get major %d",
	       _gmodule->name, _gmodule->major);
	return rc;
    }

    if(_gmodule->major == 0) {
	_gmodule->major = rc;
    }
#endif

    /* Specific module Initialization */
    if(_gmodule->init) {
	int rc;
	if((rc = _gmodule->init()) < 0) {
#ifdef GMODULE_CONFIG_DEVFS_FS
            if(devfs_handle) devfs_unregister(devfs_handle);
#else
            unregister_chrdev(_gmodule->major, _gmodule->name);
#endif
	    return rc;
	}
    }

    /* Add a /proc entry, if valid */
    if(_gmodule->pprint) {    
	_gmodule_create_proc();
    }

    return 0; /* succeed */
}