This allows LEDs to be controlled by block device activity. We already have ledtrig-disk (LED disk activity trigger), but the lower level disk drivers need to utilize ledtrig_disk_activity() to make the LED blink.
The LED block device trigger doesn't require the lower level drivers to have any instrumentation. The activity is collected by polling the disk stats. Example: echo block-nvme0n1 > /sys/class/leds/diy/trigger Cc: Frank Steiner <[email protected]> Cc: Jacek Anaszewski <[email protected]> Cc: Pavel Machek <[email protected]> Cc: Dan Murphy <[email protected]> Cc: Jens Axboe <[email protected]> Signed-off-by: Akinobu Mita <[email protected]> --- block/Makefile | 1 + block/blk-ledtrig.c | 219 ++++++++++++++++++++++++++++++++++++++++++++++++++ block/blk.h | 13 +++ block/genhd.c | 2 + include/linux/genhd.h | 4 + 5 files changed, 239 insertions(+) create mode 100644 block/blk-ledtrig.c diff --git a/block/Makefile b/block/Makefile index eee1b4c..c74d84e6 100644 --- a/block/Makefile +++ b/block/Makefile @@ -35,3 +35,4 @@ obj-$(CONFIG_BLK_DEBUG_FS) += blk-mq-debugfs.o obj-$(CONFIG_BLK_DEBUG_FS_ZONED)+= blk-mq-debugfs-zoned.o obj-$(CONFIG_BLK_SED_OPAL) += sed-opal.o obj-$(CONFIG_BLK_PM) += blk-pm.o +obj-$(CONFIG_LEDS_TRIGGERS) += blk-ledtrig.o diff --git a/block/blk-ledtrig.c b/block/blk-ledtrig.c new file mode 100644 index 0000000..da93b06 --- /dev/null +++ b/block/blk-ledtrig.c @@ -0,0 +1,219 @@ +// SPDX-License-Identifier: GPL-2.0 +// LED Kernel Blockdev Trigger +// Derived from ledtrig-netdev.c + +#include <linux/atomic.h> +#include <linux/genhd.h> +#include <linux/leds.h> +#include <linux/workqueue.h> + +struct blk_ledtrig_data { + struct delayed_work work; + struct led_classdev *led_cdev; + + atomic_t interval; + u64 last_activity; + + unsigned long mode; +#define BLK_LEDTRIG_READ BIT(0) +#define BLK_LEDTRIG_WRITE BIT(1) +#define BLK_LEDTRIG_DISCARD BIT(2) +}; + +static ssize_t blk_ledtrig_attr_show(struct device *dev, char *buf, + unsigned long blk_ledtrig) +{ + struct blk_ledtrig_data *trig_data = led_trigger_get_drvdata(dev); + + return sprintf(buf, "%u\n", test_bit(blk_ledtrig, &trig_data->mode)); +} + +static ssize_t blk_ledtrig_attr_store(struct device *dev, const char *buf, + size_t size, unsigned long blk_ledtrig) +{ + struct blk_ledtrig_data *trig_data = led_trigger_get_drvdata(dev); + unsigned long state; + int ret; + + ret = kstrtoul(buf, 0, &state); + if (ret) + return ret; + + if (state) + set_bit(blk_ledtrig, &trig_data->mode); + else + clear_bit(blk_ledtrig, &trig_data->mode); + + return size; +} + +static ssize_t read_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return blk_ledtrig_attr_show(dev, buf, BLK_LEDTRIG_READ); +} +static ssize_t read_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + return blk_ledtrig_attr_store(dev, buf, size, BLK_LEDTRIG_READ); +} +static DEVICE_ATTR_RW(read); + +static ssize_t write_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return blk_ledtrig_attr_show(dev, buf, BLK_LEDTRIG_WRITE); +} +static ssize_t write_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + return blk_ledtrig_attr_store(dev, buf, size, BLK_LEDTRIG_WRITE); +} +static DEVICE_ATTR_RW(write); + +static ssize_t discard_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + return blk_ledtrig_attr_show(dev, buf, BLK_LEDTRIG_DISCARD); +} +static ssize_t discard_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + return blk_ledtrig_attr_store(dev, buf, size, BLK_LEDTRIG_DISCARD); +} +static DEVICE_ATTR_RW(discard); + +static ssize_t interval_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct blk_ledtrig_data *trig_data = led_trigger_get_drvdata(dev); + + return sprintf(buf, "%u\n", + jiffies_to_msecs(atomic_read(&trig_data->interval))); +} +static ssize_t interval_store(struct device *dev, struct device_attribute *attr, + const char *buf, size_t size) +{ + struct blk_ledtrig_data *trig_data = led_trigger_get_drvdata(dev); + unsigned long value; + int ret; + + ret = kstrtoul(buf, 0, &value); + if (ret) + return ret; + + /* impose some basic bounds on the timer interval */ + if (value >= 5 && value <= 10000) { + cancel_delayed_work_sync(&trig_data->work); + atomic_set(&trig_data->interval, msecs_to_jiffies(value)); + schedule_delayed_work(&trig_data->work, + atomic_read(&trig_data->interval) * 2); + } + + return size; +} +static DEVICE_ATTR_RW(interval); + +static struct attribute *blk_ledtrig_attrs[] = { + &dev_attr_read.attr, + &dev_attr_write.attr, + &dev_attr_discard.attr, + &dev_attr_interval.attr, + NULL +}; +ATTRIBUTE_GROUPS(blk_ledtrig); + +static void blk_ledtrig_work(struct work_struct *work) +{ + struct blk_ledtrig_data *trig_data = + container_of(work, struct blk_ledtrig_data, work.work); + struct gendisk *disk = container_of(trig_data->led_cdev->trigger, + struct gendisk, led_trig); + u64 activity = 0; + + if (test_bit(BLK_LEDTRIG_READ, &trig_data->mode)) + activity += part_stat_read(&disk->part0, ios[STAT_READ]); + if (test_bit(BLK_LEDTRIG_WRITE, &trig_data->mode)) + activity += part_stat_read(&disk->part0, ios[STAT_WRITE]); + if (test_bit(BLK_LEDTRIG_DISCARD, &trig_data->mode)) + activity += part_stat_read(&disk->part0, ios[STAT_DISCARD]); + + if (trig_data->last_activity != activity) { + unsigned long interval; + + led_stop_software_blink(trig_data->led_cdev); + interval = jiffies_to_msecs(atomic_read(&trig_data->interval)); + led_blink_set_oneshot(trig_data->led_cdev, &interval, &interval, + 0); + + trig_data->last_activity = activity; + } + + schedule_delayed_work(&trig_data->work, + atomic_read(&trig_data->interval) * 2); +} + +static int blk_ledtrig_activate(struct led_classdev *led_cdev) +{ + struct blk_ledtrig_data *trig_data; + + trig_data = kzalloc(sizeof(*trig_data), GFP_KERNEL); + if (!trig_data) + return -ENOMEM; + + trig_data->mode = BLK_LEDTRIG_READ | BLK_LEDTRIG_WRITE | + BLK_LEDTRIG_DISCARD; + + atomic_set(&trig_data->interval, msecs_to_jiffies(50)); + trig_data->last_activity = 0; + trig_data->led_cdev = led_cdev; + + INIT_DELAYED_WORK(&trig_data->work, blk_ledtrig_work); + + led_set_trigger_data(led_cdev, trig_data); + + schedule_delayed_work(&trig_data->work, + atomic_read(&trig_data->interval) * 2); + + return 0; +} + +static void blk_ledtrig_deactivate(struct led_classdev *led_cdev) +{ + struct blk_ledtrig_data *trig_data = led_get_trigger_data(led_cdev); + + cancel_delayed_work_sync(&trig_data->work); + kfree(trig_data); +} + +int blk_ledtrig_register(struct gendisk *disk) +{ + int ret; + + disk->led_trig.name = kasprintf(GFP_KERNEL, "block-%s", + disk->disk_name); + if (!disk->led_trig.name) + return -ENOMEM; + + disk->led_trig.activate = blk_ledtrig_activate; + disk->led_trig.deactivate = blk_ledtrig_deactivate; + disk->led_trig.groups = blk_ledtrig_groups; + + ret = led_trigger_register(&disk->led_trig); + if (ret) { + kfree(disk->led_trig.name); + disk->led_trig.name = NULL; + } + + return ret; +} + +void blk_ledtrig_unregister(struct gendisk *disk) +{ + if (!disk->led_trig.name) + return; + + led_trigger_unregister(&disk->led_trig); + kfree(disk->led_trig.name); + disk->led_trig.name = NULL; +} diff --git a/block/blk.h b/block/blk.h index 7814aa2..dd4c230a 100644 --- a/block/blk.h +++ b/block/blk.h @@ -331,4 +331,17 @@ void blk_queue_free_zone_bitmaps(struct request_queue *q); static inline void blk_queue_free_zone_bitmaps(struct request_queue *q) {} #endif +#ifdef CONFIG_LEDS_TRIGGERS +int blk_ledtrig_register(struct gendisk *disk); +void blk_ledtrig_unregister(struct gendisk *disk); +#else +static inline int blk_ledtrig_register(struct gendisk *disk) +{ + return 0; +} +static inline void blk_ledtrig_unregister(struct gendisk *disk) +{ +} +#endif /* CONFIG_LEDS_TRIGGERS */ + #endif /* BLK_INTERNAL_H */ diff --git a/block/genhd.c b/block/genhd.c index 24654e1..dfd210c 100644 --- a/block/genhd.c +++ b/block/genhd.c @@ -745,6 +745,7 @@ static void __device_add_disk(struct device *parent, struct gendisk *disk, disk_add_events(disk); blk_integrity_add(disk); + blk_ledtrig_register(disk); } void device_add_disk(struct device *parent, struct gendisk *disk, @@ -766,6 +767,7 @@ void del_gendisk(struct gendisk *disk) struct disk_part_iter piter; struct hd_struct *part; + blk_ledtrig_unregister(disk); blk_integrity_del(disk); disk_del_events(disk); diff --git a/include/linux/genhd.h b/include/linux/genhd.h index 8b5330d..9250e9c 100644 --- a/include/linux/genhd.h +++ b/include/linux/genhd.h @@ -17,6 +17,7 @@ #include <linux/percpu-refcount.h> #include <linux/uuid.h> #include <linux/blk_types.h> +#include <linux/leds.h> #include <asm/local.h> #ifdef CONFIG_BLOCK @@ -219,6 +220,9 @@ struct gendisk { int node_id; struct badblocks *bb; struct lockdep_map lockdep_map; +#ifdef CONFIG_LEDS_TRIGGERS + struct led_trigger led_trig; +#endif }; static inline struct gendisk *part_to_disk(struct hd_struct *part) -- 2.7.4
