On Thu, Sep 09, 2021 at 05:25:09PM -0500, Ian Pilcher wrote:
> Add /sys/class/leds/<led>/link_device sysfs attribute
>
> If this is the first LED associated with the device, create the
> /sys/block/<disk>/blkdev_leds directory. Otherwise, increment its
> reference count.
>
> Create symlinks in /sys/class/leds/<led>/block_devices and
> /sys/block/<disk>/blkdev_leds
>
> If this the first device associated with *any* LED, schedule delayed work
> to periodically check associated devices and blink LEDs
>
> Signed-off-by: Ian Pilcher <arequipeno@xxxxxxxxx>
> ---
> drivers/leds/trigger/ledtrig-blkdev.c | 160 ++++++++++++++++++++++++++
> 1 file changed, 160 insertions(+)
>
> diff --git a/drivers/leds/trigger/ledtrig-blkdev.c b/drivers/leds/trigger/ledtrig-blkdev.c
> index 6f78a9515976..26509837f037 100644
> --- a/drivers/leds/trigger/ledtrig-blkdev.c
> +++ b/drivers/leds/trigger/ledtrig-blkdev.c
> @@ -71,6 +71,9 @@ static unsigned int ledtrig_blkdev_interval;
> static void blkdev_process(struct work_struct *const work);
> static DECLARE_DELAYED_WORK(ledtrig_blkdev_work, blkdev_process);
>
> +/* Total number of device-to-LED associations */
> +static unsigned int ledtrig_blkdev_count;
> +
>
> /*
> *
> @@ -220,6 +223,162 @@ static int blkdev_activate(struct led_classdev *const led_dev)
> }
>
>
> +/*
> + *
> + * link_device sysfs attribute - assocate a block device with this LED
> + *
> + */
> +
> +/* Gets or allocs & initializes the blkdev disk for a gendisk */
> +static int blkdev_get_disk(struct gendisk *const gd)
> +{
> + struct ledtrig_blkdev_disk *disk;
> + struct kobject *dir;
> +
> + if (gd->ledtrig != NULL) {
> + kobject_get(gd->ledtrig->dir);
When do you decrement this kobject?
> + return 0;
> + }
> +
> + disk = kmalloc(sizeof(*disk), GFP_KERNEL);
> + if (disk == NULL)
> + return -ENOMEM;
> +
> + dir = kobject_create_and_add("linked_leds", &disk_to_dev(gd)->kobj);
> + if (dir == NULL) {
> + kfree(disk);
> + return -ENOMEM;
> + }
> +
> + INIT_HLIST_HEAD(&disk->leds);
> + disk->gd = gd;
> + disk->dir = dir;
> + disk->read_ios = 0;
> + disk->write_ios = 0;
> +
> + gd->ledtrig = disk;
> +
> + return 0;
> +}
> +
> +static void blkdev_put_disk(struct ledtrig_blkdev_disk *const disk)
> +{
> + kobject_put(disk->dir);
> +
> + if (hlist_empty(&disk->leds)) {
> + disk->gd->ledtrig = NULL;
> + kfree(disk);
This should happen in the kobject release function, not here, right?
Did you try this out with removable block devices yet?
thanks,
greg k-h
