Re: [PATCH 0/8] introduce dynamic device creation/removal

Sergey Senozhatsky
2015-02-28T03:34:15Z

On (02/27/15 14:51), Andrew Morton wrote:
> hoo boy. Creating a /dev node and doing ioctls on it is really old
> school. So old school that I've forgotten why we don't do it any more.
>
> Hopefully Alan can recall the thinking?
>

perhaps, something like

static struct class_attribute zram_class_attrs[] = {
__ATTR(zram_control, S_IWUSR | S_IRUGO,
zram_control_show, zram_control_store),
__ATTR_NULL,
};

struct class zram_class = {
.name = "zram-control",
.class_attrs = zram_class_attrs,
};

class_register(&zram_class);

or (even better) separate control files

static struct class_attribute zram_class_attrs[] = {
__ATTR(zram_add, ....),
__ATTR(zram_remove, ....),
__ATTR_NULL,
};

so we can just echo `device_id' to add/remove devices

echo 1 > /sys/class/zram-control/zram_add
echo 1 > /sys/class/zram-control/zram_remove

handling it in FOO_store() functions:

static ssize_t zram_add_store(struct class *class,
struct class_attribute *attr,
char *buf)

how about this?

-ss