Create a symlink from /sys/class/leds/<LED>/block_devices to each block
device that is associated with that LED
Ensure device LED is cleared when device is removed
Signed-off-by: Ian Pilcher <arequip...@gmail.com>
---
block/blk-ledtrig.c | 93 +++++++++++++++++++++++++++++++++++++++++++++
block/blk-ledtrig.h | 3 ++
block/genhd.c | 1 +
3 files changed, 97 insertions(+)
diff --git a/block/blk-ledtrig.c b/block/blk-ledtrig.c
index c5ad57ed9c3b..280fa9edc2dd 100644
--- a/block/blk-ledtrig.c
+++ b/block/blk-ledtrig.c
@@ -6,9 +6,13 @@
* Copyright 2021 Ian Pilcher <arequip...@gmail.com>
*/
+#include <linux/genhd.h>
#include <linux/leds.h>
#include <linux/mutex.h>
+#include "blk-ledtrig.h"
+
+
/*
*
* Trigger mutex and LED list
@@ -46,3 +50,92 @@ static struct blk_ledtrig_led *blk_ledtrig_find(const char
*const led_name,
return NULL;
}
+
+
+/*
+ *
+ * Clear a block device's LED
+ *
+ */
+
+// Also called from blk_ledtrig_dev_set()
+static void blk_ledtrig_dev_cleanup(struct gendisk *const disk,
+ struct blk_ledtrig_led *const old_led)
+{
+ sysfs_remove_link(old_led->dir, disk->disk_name);
+ list_del(&disk->led_dev_list_node);
+}
+
+// Also called from blk_ledtrig_deactivate()
+static void blk_ledtrig_dev_clear_locked(struct gendisk *const disk,
+ struct blk_ledtrig_led *const old_led)
+{
+ RCU_INIT_POINTER(disk->led, NULL);
+ if (old_led != NULL)
+ blk_ledtrig_dev_cleanup(disk, old_led);
+}
+
+// Also called from genhd.c:del_gendisk()
+void blk_ledtrig_dev_clear(struct gendisk *const disk)
+{
+ struct blk_ledtrig_led *old_led;
+
+ mutex_lock(&blk_ledtrig_mutex);
+ old_led = rcu_dereference_protected(disk->led,
+ lockdep_is_held(&blk_ledtrig_mutex));
+ blk_ledtrig_dev_clear_locked(disk, old_led);
+ mutex_unlock(&blk_ledtrig_mutex);
+}
+
+
+/*
+ *
+ * Set a block device's LED
+ *
+ */
+
+static int blk_ledtrig_dev_set(struct gendisk *const disk,
+ const char *const led_name,
+ const size_t name_len)
+{
+ struct blk_ledtrig_led *new_led, *old_led;
+ int ret;
+
+ ret = mutex_lock_interruptible(&blk_ledtrig_mutex);
+ if (ret != 0)
+ goto led_set_exit_return;
+
+ new_led = blk_ledtrig_find(led_name, name_len);
+ if (new_led == NULL) {
+ pr_info("no LED named %.*s associated with blkdev trigger\n",
+ (int)name_len, led_name);
+ ret = -ENODEV;
+ goto led_set_exit_unlock;
+ }
+
+ old_led = rcu_dereference_protected(disk->led,
+ lockdep_is_held(&blk_ledtrig_mutex));
+
+ if (old_led == new_led) {
+ ret = 0;
+ goto led_set_exit_unlock;
+ }
+
+ ret = sysfs_create_link(new_led->dir, &disk_to_dev(disk)->kobj,
+ disk->disk_name);
+ if (ret != 0)
+ goto led_set_exit_unlock;
+
+ if (old_led != NULL)
+ blk_ledtrig_dev_cleanup(disk, old_led);
+
+ rcu_assign_pointer(disk->led, new_led);
+ list_add(&disk->led_dev_list_node, &new_led->dev_list);
+
+ ret = 0;
+
+led_set_exit_unlock:
+ mutex_unlock(&blk_ledtrig_mutex);
+led_set_exit_return:
+ return ret;
+}
diff --git a/block/blk-ledtrig.h b/block/blk-ledtrig.h
index 95a79d2fe447..66a1302a4174 100644
--- a/block/blk-ledtrig.h
+++ b/block/blk-ledtrig.h
@@ -16,9 +16,12 @@ static inline void blk_ledtrig_disk_init(struct gendisk
*const disk)
RCU_INIT_POINTER(disk->led, NULL);
}
+void blk_ledtrig_dev_clear(struct gendisk *const disk);
+
#else // CONFIG_BLK_LED_TRIGGERS
static inline void blk_ledtrig_disk_init(const struct gendisk *disk) {}
+static inline void blk_ledtrig_dev_clear(const struct gendisk *disk) {}
#endif // CONFIG_BLK_LED_TRIGGERS
diff --git a/block/genhd.c b/block/genhd.c
index b168172e664b..9fa734aeab0f 100644
--- a/block/genhd.c
+++ b/block/genhd.c
@@ -583,6 +583,7 @@ void del_gendisk(struct gendisk *disk)
if (WARN_ON_ONCE(!disk->queue))
return;
+ blk_ledtrig_dev_clear(disk);
blk_integrity_del(disk);
disk_del_events(disk);
--
2.31.1
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