dm io tracker: factor out IO tracker

Allow other code to use dm_io_tracker.

Signed-off-by: Mike Snitzer <snitzer@redhat.com>

Author: snitm

drivers/md/dm-cache-target.c

@@ -8,6 +8,7 @@
 #include "dm-bio-prison-v2.h"
 #include "dm-bio-record.h"
 #include "dm-cache-metadata.h"
+#include "dm-io-tracker.h"
 
 #include <linux/dm-io.h>
 #include <linux/dm-kcopyd.h>
@@ -39,77 +40,6 @@ DECLARE_DM_KCOPYD_THROTTLE_WITH_MODULE_PARM(cache_copy_throttle,
 
 /*----------------------------------------------------------------*/
 
-struct 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 void iot_init(struct io_tracker *iot)
-{
-	spin_lock_init(&iot->lock);
-	iot->in_flight = 0ul;
-	iot->idle_time = 0ul;
-	iot->last_update_time = jiffies;
-}
-
-static bool __iot_idle_for(struct io_tracker *iot, unsigned long jifs)
-{
-	if (iot->in_flight)
-		return false;
-
-	return time_after(jiffies, iot->idle_time + jifs);
-}
-
-static bool iot_idle_for(struct io_tracker *iot, unsigned long jifs)
-{
-	bool r;
-
-	spin_lock_irq(&iot->lock);
-	r = __iot_idle_for(iot, jifs);
-	spin_unlock_irq(&iot->lock);
-
-	return r;
-}
-
-static void iot_io_begin(struct io_tracker *iot, sector_t len)
-{
-	spin_lock_irq(&iot->lock);
-	iot->in_flight += len;
-	spin_unlock_irq(&iot->lock);
-}
-
-static void __iot_io_end(struct io_tracker *iot, sector_t len)
-{
-	if (!len)
-		return;
-
-	iot->in_flight -= len;
-	if (!iot->in_flight)
-		iot->idle_time = jiffies;
-}
-
-static void iot_io_end(struct io_tracker *iot, sector_t len)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&iot->lock, flags);
-	__iot_io_end(iot, len);
-	spin_unlock_irqrestore(&iot->lock, flags);
-}
-
-/*----------------------------------------------------------------*/
-
 /*
  * Represents a chunk of future work.  'input' allows continuations to pass
  * values between themselves, typically error values.
@@ -470,7 +400,7 @@ struct cache {
 	struct batcher committer;
 	struct work_struct commit_ws;
 
-	struct io_tracker tracker;
+	struct dm_io_tracker tracker;
 
 	mempool_t migration_pool;
 
@@ -866,15 +796,15 @@ static void accounted_begin(struct cache *cache, struct bio *bio)
 	if (accountable_bio(cache, bio)) {
 		pb = get_per_bio_data(bio);
 		pb->len = bio_sectors(bio);
-		iot_io_begin(&cache->tracker, pb->len);
+		dm_iot_io_begin(&cache->tracker, pb->len);
 	}
 }
 
 static void accounted_complete(struct cache *cache, struct bio *bio)
 {
 	struct per_bio_data *pb = get_per_bio_data(bio);
 
-	iot_io_end(&cache->tracker, pb->len);
+	dm_iot_io_end(&cache->tracker, pb->len);
 }
 
 static void accounted_request(struct cache *cache, struct bio *bio)
@@ -1642,7 +1572,7 @@ enum busy {
 
 static enum busy spare_migration_bandwidth(struct cache *cache)
 {
-	bool idle = iot_idle_for(&cache->tracker, HZ);
+	bool idle = dm_iot_idle_for(&cache->tracker, HZ);
 	sector_t current_volume = (atomic_read(&cache->nr_io_migrations) + 1) *
 		cache->sectors_per_block;
 
@@ -2603,7 +2533,7 @@ static int cache_create(struct cache_args *ca, struct cache **result)
 
 	batcher_init(&cache->committer, commit_op, cache,
 		     issue_op, cache, cache->wq);
-	iot_init(&cache->tracker);
+	dm_iot_init(&cache->tracker);
 
 	init_rwsem(&cache->background_work_lock);
 	prevent_background_work(cache);

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 <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 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