um: ubd: Set device serial attribute from cmdline

	/* name (and fd, below) of the file opened for writing, either the

	 * backing or the cow file. */

	char *file;

	char *serial;

	int count;

	int fd;

	__u64 size;

#define DEFAULT_UBD { \

	.file = 		NULL, \

	.serial =		NULL, \

	.count =		0, \

	.fd =			-1, \

	.size =			-1, \

{

	struct ubd *ubd_dev;

	struct openflags flags = global_openflags;

	char *backing_file;

	char *file, *backing_file, *serial;

	int n, err = 0, i;

	if(index_out) *index_out = -1;

	goto out;

break_loop:

	backing_file = strchr(str, ',');

	file = strsep(&str, ",:");

	if (*file == '\0')

		file = NULL;

	backing_file = strsep(&str, ",:");

	if (*backing_file == '\0')

		backing_file = NULL;

	if (backing_file == NULL)

		backing_file = strchr(str, ':');

	serial = strsep(&str, ",:");

	if (*serial == '\0')

		serial = NULL;

	if(backing_file != NULL){

		if(ubd_dev->no_cow){

	if (backing_file && ubd_dev->no_cow) {

		*error_out = "Can't specify both 'd' and a cow file";

		goto out;

	}

		else {

			*backing_file = '\0';

			backing_file++;

		}

	}

	err = 0;

	ubd_dev->file = str;

	ubd_dev->file = file;

	ubd_dev->cow.file = backing_file;

	ubd_dev->serial = serial;

	ubd_dev->boot_openflags = flags;

out:

	mutex_unlock(&ubd_lock);

__setup("ubd", ubd_setup);

__uml_help(ubd_setup,

"ubd<n><flags>=<filename>[(:|,)<filename2>]\n"

"ubd<n><flags>=<filename>[(:|,)<filename2>][(:|,)<serial>]\n"

"    This is used to associate a device with a file in the underlying\n"

"    filesystem. When specifying two filenames, the first one is the\n"

"    COW name and the second is the backing file name. As separator you can\n"

"    UMLs and file locking will be turned off - this is appropriate for a\n"

"    cluster filesystem and inappropriate at almost all other times.\n\n"

"    't' will disable trim/discard support on the device (enabled by default).\n\n"

"    An optional device serial number can be exposed using the serial parameter\n"

"    on the cmdline which is exposed as a sysfs entry. This is particularly\n"

"    useful when a unique number should be given to the device. Note when\n"

"    specifying a label, the filename2 must be also presented. It can be\n"

"    an empty string, in which case the backing file is not used:\n"

"       ubd0=File,,Serial\n"

);

static int udb_setup(char *str)

	*ubd_dev = ((struct ubd) DEFAULT_UBD);

}

static ssize_t serial_show(struct device *dev,

			   struct device_attribute *attr, char *buf)

{

	struct gendisk *disk = dev_to_disk(dev);

	struct ubd *ubd_dev = disk->private_data;

	if (!ubd_dev)

		return 0;

	return sprintf(buf, "%s", ubd_dev->serial);

}

static DEVICE_ATTR_RO(serial);

static struct attribute *ubd_attrs[] = {

	&dev_attr_serial.attr,

	NULL,

};

static umode_t ubd_attrs_are_visible(struct kobject *kobj,

				     struct attribute *a, int n)

{

	return a->mode;

}

static const struct attribute_group ubd_attr_group = {

	.attrs = ubd_attrs,

	.is_visible = ubd_attrs_are_visible,

};

static const struct attribute_group *ubd_attr_groups[] = {

	&ubd_attr_group,

	NULL,

};

static int ubd_disk_register(int major, u64 size, int unit,

			     struct gendisk **disk_out)

{

	disk->private_data = &ubd_devs[unit];

	disk->queue = ubd_devs[unit].queue;

	device_add_disk(parent, disk, NULL);

	device_add_disk(parent, disk, ubd_attr_groups);

	*disk_out = disk;

	return 0;