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/*
* 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
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