| Message ID | 20210914201713.14922-3-arequipeno@gmail.com |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce block device LED trigger | expand |
diff --git a/block/genhd.c b/block/genhd.c index 7b6e5e1cf956..ebea496bc283 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -1076,6 +1076,7 @@ struct class block_class = { .name = "block", .dev_uevent = block_uevent, }; +EXPORT_SYMBOL_NS_GPL(block_class, LEDTRIG_BLKDEV); static char *block_devnode(struct device *dev, umode_t *mode, kuid_t *uid, kgid_t *gid)
Export block_class to the LEDTRIG_BLKDEV namespace. The block device (blkdev) LED trigger periodically checks the activity counters of block devices and blinks LEDs to reflect that activity. The specific block device(s) checked can be configured through a sysfs API. Once an LED has been associated with the blkdev trigger, the LED can be "linked" to a block device by writing that device's name to the LED's link_device attribute. For example: echo sda > /sys/class/leds/<led>/link_device When a block device name is written to the sysfs attribute, the trigger uses class_find_device_by_name() to resolve the actual block_device structure: dev = class_find_device_by_name(&block_class, name); Exporting the block_class symbol makes it possible to build the LED trigger as a module. Signed-off-by: Ian Pilcher <arequipeno@gmail.com> --- block/genhd.c | 1 + 1 file changed, 1 insertion(+)