Re: [PATCH v2 11/15] leds: trigger: blkdev: Enable linking block devices to LEDs
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2021-09-10 06:49:05
Also in:
linux-block, lkml
On Thu, Sep 09, 2021 at 05:25:09PM -0500, Ian Pilcher wrote:
quoted hunk ↗ jump to hunk
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 <redacted> --- 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