Use a delayed workqueue to periodically check configured block devices for activity since the last check. Blink LEDs associated with devices on which the configured type of activity (read/write) has occurred. Signed-off-by: Ian Pilcher <arequipeno@gmail.com> --- drivers/leds/trigger/ledtrig-blkdev.c | 87 +++++++++++++++++++++++++++ 1 file changed, 87 insertions(+) diff --git a/drivers/leds/trigger/ledtrig-blkdev.c b/drivers/leds/trigger/ledtrig-blkdev.c index fcae7ce63b92..e9c23824c33c 100644 --- a/drivers/leds/trigger/ledtrig-blkdev.c +++ b/drivers/leds/trigger/ledtrig-blkdev.c @@ -7,9 +7,11 @@ */ #include <linux/ctype.h> +#include <linux/genhd.h> #include <linux/leds.h> #include <linux/list.h> #include <linux/mutex.h> +#include <linux/part_stat.h> /* Default blink time & polling interval (milliseconds) */ #define LEDTRIG_BLKDEV_BLINK_MSEC 75 @@ -66,6 +68,9 @@ static unsigned int ledtrig_blkdev_count; /* How often to check for drive activity - in jiffies */ static unsigned int ledtrig_blkdev_interval; +static void blkdev_process(struct work_struct *const work); +static DECLARE_DELAYED_WORK(ledtrig_blkdev_work, blkdev_process); + /* * @@ -138,3 +143,85 @@ static bool blkdev_write_mode(const enum ledtrig_blkdev_mode mode) { return mode != LEDTRIG_BLKDEV_MODE_RO; } + + +/* + * + * Periodically check for device acitivity and blink LEDs + * + */ + +static void blkdev_blink(const struct ledtrig_blkdev_led *const led) +{ + unsigned long delay_on = READ_ONCE(led->blink_msec); + unsigned long delay_off = 1; /* 0 leaves LED turned on */ + + led_blink_set_oneshot(led->led_dev, &delay_on, &delay_off, 0); +} + +static void blkdev_update_disk(struct ledtrig_blkdev_disk *const disk, + const unsigned int generation) +{ + const struct block_device *const part0 = disk->gd->part0; + const unsigned long read_ios = part_stat_read(part0, ios[STAT_READ]); + const unsigned long write_ios = part_stat_read(part0, ios[STAT_WRITE]) + + part_stat_read(part0, ios[STAT_DISCARD]) + + part_stat_read(part0, ios[STAT_FLUSH]); + + if (disk->read_ios != read_ios) { + disk->read_act = true; + disk->read_ios = read_ios; + } else { + disk->read_act = false; + } + + if (disk->write_ios != write_ios) { + disk->write_act = true; + disk->write_ios = write_ios; + } else { + disk->write_act = false; + } + + disk->generation = generation; +} + +static void blkdev_process(struct work_struct *const work) +{ + static unsigned int generation; + + struct ledtrig_blkdev_led *led; + struct ledtrig_blkdev_link *link; + unsigned long delay; + + if (!mutex_trylock(&ledtrig_blkdev_mutex)) + goto exit_reschedule; + + hlist_for_each_entry(led, &ledtrig_blkdev_leds, leds_node) { + + hlist_for_each_entry(link, &led->disks, led_disks_node) { + + struct ledtrig_blkdev_disk *const disk = link->disk; + + if (disk->generation != generation) + blkdev_update_disk(disk, generation); + + if (disk->read_act && blkdev_read_mode(led->mode)) { + blkdev_blink(led); + break; + } + + if (disk->write_act && blkdev_write_mode(led->mode)) { + blkdev_blink(led); + break; + } + } + } + + ++generation; + + mutex_unlock(&ledtrig_blkdev_mutex); + +exit_reschedule: + delay = READ_ONCE(ledtrig_blkdev_interval); + WARN_ON_ONCE(!schedule_delayed_work(&ledtrig_blkdev_work, delay)); +} -- 2.31.1