Disk cleanup function - blkdev_disk_cleanup():
* Called when block device is being removed
* Called via __ledtrig_blkdev_disk_cleanup function pointer from
ledtrig_blkdev_disk_cleanup() in ledtrig-blkdev-core.c
Init function - blkdev_init():
* Initialize interval (convert default value to jiffies)
* Initialize __ledtrig_blkdev_disk_cleanup function pointer
* Register the block device LED trigger
Exit function - blkdev_exit():
* Unregister the LED trigger
* Set __ledtrig_blkdev_disk_cleanup back to NULL
Make LED trigger struct (ledtrig_blkdev_trigger) static (as it's now
referenced in blkdev_init()).
Signed-off-by: Ian Pilcher <arequipeno@xxxxxxxxx>
---
drivers/leds/trigger/ledtrig-blkdev.c | 65 ++++++++++++++++++++++++++-
1 file changed, 64 insertions(+), 1 deletion(-)
diff --git a/drivers/leds/trigger/ledtrig-blkdev.c b/drivers/leds/trigger/ledtrig-blkdev.c
index 4b88f877ee81..96ea694ce29f 100644
--- a/drivers/leds/trigger/ledtrig-blkdev.c
+++ b/drivers/leds/trigger/ledtrig-blkdev.c
@@ -435,6 +435,23 @@ static ssize_t unlink_device_store(struct device *const dev,
static DEVICE_ATTR_WO(unlink_device);
+/*
+ *
+ * Disassociate all LEDs from a block device (because it's going away)
+ *
+ */
+
+static void blkdev_disk_cleanup(struct gendisk *const gd)
+{
+ struct ledtrig_blkdev_link *link;
+ struct hlist_node *next;
+
+ hlist_for_each_entry_safe(link, next,
+ &gd->ledtrig->leds, disk_leds_node)
+ blkdev_disk_unlink_locked(link->led, link, gd->ledtrig);
+}
+
+
/*
*
* Disassociate an LED from the trigger
@@ -615,9 +632,55 @@ static const struct attribute_group *ledtrig_blkdev_attr_groups[] = {
NULL
};
-struct led_trigger ledtrig_blkdev_trigger = {
+static struct led_trigger ledtrig_blkdev_trigger = {
.name = "blkdev",
.activate = blkdev_activate,
.deactivate = blkdev_deactivate,
.groups = ledtrig_blkdev_attr_groups,
};
+
+static int __init blkdev_init(void)
+{
+ int ret;
+
+ ret = mutex_lock_interruptible(&ledtrig_blkdev_mutex);
+ if (ret != 0)
+ return ret;
+
+ ledtrig_blkdev_interval = msecs_to_jiffies(LEDTRIG_BLKDEV_INTERVAL);
+ __ledtrig_blkdev_disk_cleanup = blkdev_disk_cleanup;
+
+ /*
+ * Can't call led_trigger_register() with ledtrig_blkdev_mutex locked.
+ * If an LED has blkdev as its default_trigger, blkdev_activate() will
+ * be called for that LED, and it will try to lock the mutex, which will
+ * hang.
+ */
+ mutex_unlock(&ledtrig_blkdev_mutex);
+
+ ret = led_trigger_register(&ledtrig_blkdev_trigger);
+ if (ret != 0) {
+ mutex_lock(&ledtrig_blkdev_mutex);
+ __ledtrig_blkdev_disk_cleanup = NULL;
+ mutex_unlock(&ledtrig_blkdev_mutex);
+ }
+
+ return ret;
+}
+module_init(blkdev_init);
+
+static void __exit blkdev_exit(void)
+{
+ mutex_lock(&ledtrig_blkdev_mutex);
+
+ /*
+ * It's OK to call led_trigger_unregister() with the mutex locked,
+ * because the module can only be unloaded when no LEDs are using
+ * the blkdev trigger, so blkdev_deactivate() won't be called.
+ */
+ led_trigger_unregister(&ledtrig_blkdev_trigger);
+ __ledtrig_blkdev_disk_cleanup = NULL;
+
+ mutex_unlock(&ledtrig_blkdev_mutex);
+}
+module_exit(blkdev_exit);
--
2.31.1
