/* * 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 <linux/jiffies.h> 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 unsigned long dm_iot_idle_time(struct dm_io_tracker *iot) { unsigned long r = 0; spin_lock_irq(&iot->lock); if (!iot->in_flight) r = jiffies - iot->idle_time; 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