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@gmail.com> --- 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