* New file - include/linux/blk-ledtrig.h
Signed-off-by: Ian Pilcher <arequipeno@xxxxxxxxx>
---
block/blk-ledtrig.c | 152 ++++++++++++++++++++++++++++++++++++
include/linux/blk-ledtrig.h | 19 +++++
2 files changed, 171 insertions(+)
create mode 100644 include/linux/blk-ledtrig.h
diff --git a/block/blk-ledtrig.c b/block/blk-ledtrig.c
index 345a3b6bdbc6..c69ea1539336 100644
--- a/block/blk-ledtrig.c
+++ b/block/blk-ledtrig.c
@@ -6,9 +6,11 @@
* Copyright 2021 Ian Pilcher <arequipeno@xxxxxxxxx>
*/
+#include <linux/blk-ledtrig.h>
#include <linux/leds.h>
#include <linux/list.h>
#include <linux/mutex.h>
+#include <linux/slab.h>
/*
@@ -49,3 +51,153 @@ static struct blk_ledtrig *blk_ledtrig_find(const char *const name,
return NULL;
}
+
+
+/*
+ *
+ * Create a new trigger
+ *
+ */
+
+static int __blk_ledtrig_create(const char *const name, const size_t len)
+{
+ struct blk_ledtrig *t;
+ int ret;
+
+ if (len == 0) {
+ pr_warn("empty name specified for blockdev LED trigger\n");
+ ret = -EINVAL;
+ goto create_exit_return;
+ }
+
+ ret = mutex_lock_interruptible(&blk_ledtrig_list_mutex);
+ if (unlikely(ret != 0))
+ goto create_exit_return;
+
+ if (blk_ledtrig_find(name, len) != NULL) {
+ pr_warn("blockdev LED trigger named %.*s already exists\n",
+ (int)len, name);
+ ret = -EEXIST;
+ goto create_exit_unlock_list;
+ }
+
+ t = kzalloc(sizeof(*t) + len + 1, GFP_KERNEL);
+ if (unlikely(t == NULL)) {
+ ret = -ENOMEM;
+ goto create_exit_unlock_list;
+ }
+
+ memcpy(t->name, name, len);
+ t->trigger.name = t->name;
+ mutex_init(&t->refcount_mutex);
+
+ ret = led_trigger_register(&t->trigger);
+ if (ret != 0) {
+ if (likely(ret == -EEXIST)) {
+ pr_warn("LED trigger named %.*s already exists\n",
+ (int)len, name);
+ }
+ goto create_exit_free;
+ }
+
+ list_add(&t->list_node, &blk_ledtrig_list);
+ ret = 0;
+
+create_exit_free:
+ if (ret != 0)
+ kfree(t);
+create_exit_unlock_list:
+ mutex_unlock(&blk_ledtrig_list_mutex);
+create_exit_return:
+ return ret;
+}
+
+/**
+ * blk_ledtrig_create() - creates a new block device LED trigger
+ * @name: the name of the new trigger
+ *
+ * Context: Process context (can sleep). Takes and releases
+ * @blk_ledtrig_list_mutex.
+ *
+ * Return: 0 on success; -@errno on error
+ */
+int blk_ledtrig_create(const char *const name)
+{
+ return __blk_ledtrig_create(name, strlen(name));
+}
+EXPORT_SYMBOL_GPL(blk_ledtrig_create);
+
+
+/*
+ *
+ * Delete a trigger
+ *
+ */
+
+static int __blk_ledtrig_delete(const char *const name, const size_t len)
+{
+ struct blk_ledtrig *t;
+ int ret;
+
+ if (len == 0) {
+ pr_warn("empty name specified for blockdev LED trigger\n");
+ ret = -EINVAL;
+ goto delete_exit_return;
+ }
+
+ ret = mutex_lock_interruptible(&blk_ledtrig_list_mutex);
+ if (unlikely(ret != 0))
+ goto delete_exit_return;
+
+ t = blk_ledtrig_find(name, len);
+ if (t == NULL) {
+ pr_warn("blockdev LED trigger named %.*s doesn't exist\n",
+ (int)len, name);
+ ret = -ENODEV;
+ goto delete_exit_unlock_list;
+ }
+
+ ret = mutex_lock_interruptible(&t->refcount_mutex);
+ if (unlikely(ret != 0))
+ goto delete_exit_unlock_list;
+
+ if (WARN_ON(t->refcount < 0)) {
+ ret = -EBADFD;
+ goto delete_exit_unlock_refcount;
+ }
+
+ if (t->refcount > 0) {
+ pr_warn("blockdev LED trigger %s still in use\n", t->name);
+ ret = -EBUSY;
+ goto delete_exit_unlock_refcount;
+ }
+
+ led_trigger_unregister(&t->trigger);
+ list_del(&t->list_node);
+
+ ret = 0;
+
+delete_exit_unlock_refcount:
+ mutex_unlock(&t->refcount_mutex);
+ if (ret == 0)
+ kfree(t);
+delete_exit_unlock_list:
+ mutex_unlock(&blk_ledtrig_list_mutex);
+delete_exit_return:
+ return ret;
+}
+
+/**
+ * blk_ledtrig_delete() - deletes a block device LED trigger
+ * @name: the name of the trigger to be deleted
+ *
+ * Context: Process context (can sleep). Takes and releases
+ * @blk_ledtrig_list_mutex and trigger's @refcount_mutex.
+ *
+ * Return: 0 on success; -@errno on error
+ */
+int blk_ledtrig_delete(const char *const name)
+{
+ return __blk_ledtrig_delete(name, strlen(name));
+}
+EXPORT_SYMBOL_GPL(blk_ledtrig_delete);
diff --git a/include/linux/blk-ledtrig.h b/include/linux/blk-ledtrig.h
new file mode 100644
index 000000000000..6f73635f65ec
--- /dev/null
+++ b/include/linux/blk-ledtrig.h
@@ -0,0 +1,19 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+/*
+ * Block device LED triggers
+ *
+ * Copyright 2021 Ian Pilcher <arequipeno@xxxxxxxxx>
+ */
+
+#ifndef _LINUX_BLK_LEDTRIG_H
+#define _LINUX_BLK_LEDTRIG_H
+
+#ifdef CONFIG_BLK_LED_TRIGGERS
+
+int blk_ledtrig_create(const char *name);
+int blk_ledtrig_delete(const char *name);
+
+#endif // CONFIG_BLK_LED_TRIGGERS
+
+#endif // _LINUX_BLK_LEDTRIG_H
--
2.31.1
