Set up activated LED:
* Allocate per-LED data structure
* Add LED to list of LEDs associated with blkdev trigger
* Create block_devices subdirectory for links to associated devices
Clean up deactivated LED:
* Clear LED of any associated devices
* Remove from LED from blkdev trigger list
* Remove block_devices subdirectory
* Wait for any blinks using LED to complete (synchronize_rcu())
* Free per-LED structure
Signed-off-by: Ian Pilcher <arequipeno@xxxxxxxxx>
---
block/blk-ledtrig.c | 95 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 95 insertions(+)
diff --git a/block/blk-ledtrig.c b/block/blk-ledtrig.c
index 1af94dc7ea51..f8cb6de203f8 100644
--- a/block/blk-ledtrig.c
+++ b/block/blk-ledtrig.c
@@ -13,6 +13,11 @@
#include "blk-ledtrig.h"
+// Default blink_on & blink_off values
+#define BLK_LEDTRIG_BLINK_ON 75
+#define BLK_LEDTRIG_BLINK_OFF 25
+#define BLK_LEDTRIG_BLINK_MAX 10000 // 10 seconds
+
/*
*
@@ -248,3 +253,93 @@ ssize_t blk_ledtrig_dev_led_show(struct device *const dev,
led_show_exit_return:
return ret;
}
+
+
+/*
+ *
+ * Associate an LED with the blkdev trigger
+ *
+ */
+
+// Helper function to create <LED>/blkdevs subdirectory - doesn't
+// swallow error code like kobject_create_and_add()
+static int blk_ledtrig_subdir_create(struct blk_ledtrig_led *const bd_led,
+ struct led_classdev *const led)
+{
+ int ret;
+
+ bd_led->dir = kobject_create();
+ if (bd_led->dir == NULL)
+ return -ENOMEM;
+
+ ret = kobject_add(bd_led->dir, &led->dev->kobj, "block_devices");
+ if (ret != 0)
+ kobject_put(bd_led->dir);
+
+ return ret;
+}
+
+static int blk_ledtrig_activate(struct led_classdev *const led)
+{
+ struct blk_ledtrig_led *bd_led;
+ int ret;
+
+ bd_led = kmalloc(sizeof(*bd_led), GFP_KERNEL);
+ if (bd_led == NULL) {
+ ret = -ENOMEM;
+ goto activate_exit_return;
+ }
+
+ bd_led->led = led;
+ bd_led->blink_on = BLK_LEDTRIG_BLINK_ON;
+ bd_led->blink_off = BLK_LEDTRIG_BLINK_OFF;
+ INIT_LIST_HEAD(&bd_led->dev_list);
+
+ ret = mutex_lock_interruptible(&blk_ledtrig_mutex);
+ if (ret != 0)
+ goto activate_exit_free;
+
+ ret = blk_ledtrig_subdir_create(bd_led, led);
+ if (ret != 0)
+ goto activate_exit_unlock;
+
+ list_add(&bd_led->leds_list_node, &blk_ledtrig_leds);
+ led_set_trigger_data(led, bd_led);
+ ret = 0;
+
+activate_exit_unlock:
+ mutex_unlock(&blk_ledtrig_mutex);
+activate_exit_free:
+ if (ret != 0)
+ kfree(bd_led);
+activate_exit_return:
+ return ret;
+}
+
+
+/*
+ *
+ * Disassociate an LED from the blkdev trigger
+ *
+ */
+
+static void blk_ledtrig_deactivate(struct led_classdev *const led)
+{
+ struct blk_ledtrig_led *const bd_led = led_get_trigger_data(led);
+ struct gendisk *disk, *next;
+
+ mutex_lock(&blk_ledtrig_mutex);
+
+ list_for_each_entry_safe(disk, next,
+ &bd_led->dev_list, led_dev_list_node) {
+
+ blk_ledtrig_dev_clear_locked(disk, bd_led);
+ }
+
+ list_del(&bd_led->leds_list_node);
+ kobject_put(bd_led->dir);
+
+ mutex_unlock(&blk_ledtrig_mutex);
+ synchronize_rcu();
+ kfree(bd_led);
+}
--
2.31.1
