From dc4fa29fe445933f51e08674f3b325547ba52de1 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Fri, 25 Jun 2021 12:10:26 -0400 Subject: dm io tracker: factor out IO tracker Allow other code to use dm_io_tracker. Signed-off-by: Mike Snitzer --- drivers/md/dm-io-tracker.h | 69 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 drivers/md/dm-io-tracker.h (limited to 'drivers/md/dm-io-tracker.h') diff --git a/drivers/md/dm-io-tracker.h b/drivers/md/dm-io-tracker.h new file mode 100644 index 000000000000..1dcf01f9f066 --- /dev/null +++ b/drivers/md/dm-io-tracker.h @@ -0,0 +1,69 @@ +/* + * Copyright (C) 2021 Red Hat, Inc. All rights reserved. + * + * This file is released under the GPL. + */ + +#ifndef DM_IO_TRACKER_H +#define DM_IO_TRACKER_H + +#include + +struct dm_io_tracker { + spinlock_t lock; + + /* + * Sectors of in-flight IO. + */ + sector_t in_flight; + + /* + * The time, in jiffies, when this device became idle + * (if it is indeed idle). + */ + unsigned long idle_time; + unsigned long last_update_time; +}; + +static inline void dm_iot_init(struct dm_io_tracker *iot) +{ + spin_lock_init(&iot->lock); + iot->in_flight = 0ul; + iot->idle_time = 0ul; + iot->last_update_time = jiffies; +} + +static inline bool dm_iot_idle_for(struct dm_io_tracker *iot, unsigned long j) +{ + bool r = false; + + spin_lock_irq(&iot->lock); + if (!iot->in_flight) + r = time_after(jiffies, iot->idle_time + j); + spin_unlock_irq(&iot->lock); + + return r; +} + +static inline void dm_iot_io_begin(struct dm_io_tracker *iot, sector_t len) +{ + spin_lock_irq(&iot->lock); + iot->in_flight += len; + spin_unlock_irq(&iot->lock); +} + +static inline void dm_iot_io_end(struct dm_io_tracker *iot, sector_t len) +{ + unsigned long flags; + + if (!len) + return; + + spin_lock_irqsave(&iot->lock, flags); + iot->in_flight -= len; + if (!iot->in_flight) + iot->idle_time = jiffies; + spin_unlock_irqrestore(&iot->lock, flags); +} + +#endif -- cgit v1.2.3