drbd: Actually send delay probes

Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>

drivers/block/drbd/drbd_int.h

@@ -925,9 +925,11 @@ struct drbd_conf {
 	unsigned int ko_count;
 	struct drbd_work  resync_work,
 			  unplug_work,
-			  md_sync_work;
+			  md_sync_work,
+			  delay_probe_work;
 	struct timer_list resync_timer;
 	struct timer_list md_sync_timer;
+	struct timer_list delay_probe_timer;
 
 	/* Used after attach while negotiating new disk state. */
 	union drbd_state new_state_tmp;
@@ -1047,6 +1049,8 @@ struct drbd_conf {
 	int data_delay;   /* Delay of packets on the data-sock behind meta-sock */
 	atomic_t delay_seq; /* To generate sequence numbers of delay probes */
 	struct timeval dps_time; /* delay-probes-start-time */
+	int dp_volume_last;  /* send_cnt of last delay probe */
+	int c_sync_rate; /* current resync rate after delay_probe magic */
 };
 
 static inline struct drbd_conf *minor_to_mdev(unsigned int minor)

drivers/block/drbd/drbd_main.c

@@ -2207,10 +2207,13 @@ static int drbd_send_delay_probe(struct drbd_conf *mdev, struct drbd_socket *ds)
 	}
 	mutex_unlock(&ds->mutex);
 
+	mdev->dp_volume_last = mdev->send_cnt;
+	mod_timer(&mdev->delay_probe_timer, jiffies + mdev->sync_conf.dp_interval * HZ / 10);
+
 	return ok;
 }
 
-static int drbd_send_dalay_probes(struct drbd_conf *mdev)
+static int drbd_send_delay_probes(struct drbd_conf *mdev)
 {
 	int ok;
 	atomic_inc(&mdev->delay_seq);
@@ -2350,6 +2353,30 @@ static int _drbd_send_zc_bio(struct drbd_conf *mdev, struct bio *bio)
 	return 1;
 }
 
+static void consider_delay_probes(struct drbd_conf *mdev)
+{
+	if (mdev->state.conn != C_SYNC_SOURCE)
+		return;
+
+	if (mdev->dp_volume_last + mdev->sync_conf.dp_volume * 2 < mdev->send_cnt)
+		drbd_send_delay_probes(mdev);
+}
+
+static int w_delay_probes(struct drbd_conf *mdev, struct drbd_work *w, int cancel)
+{
+	if (!cancel && mdev->state.conn == C_SYNC_SOURCE)
+		drbd_send_delay_probes(mdev);
+
+	return 1;
+}
+
+static void delay_probe_timer_fn(unsigned long data)
+{
+	struct drbd_conf *mdev = (struct drbd_conf *) data;
+
+	drbd_queue_work(&mdev->data.work, &mdev->delay_probe_work);
+}
+
 /* Used to send write requests
  * R_PRIMARY -> Peer	(P_DATA)
  */
@@ -2412,6 +2439,10 @@ int drbd_send_dblock(struct drbd_conf *mdev, struct drbd_request *req)
 	}
 
 	drbd_put_data_sock(mdev);
+
+	if (ok)
+		consider_delay_probes(mdev);
+
 	return ok;
 }
 
@@ -2457,6 +2488,10 @@ int drbd_send_block(struct drbd_conf *mdev, enum drbd_packets cmd,
 		ok = _drbd_send_zc_bio(mdev, e->private_bio);
 
 	drbd_put_data_sock(mdev);
+
+	if (ok)
+		consider_delay_probes(mdev);
+
 	return ok;
 }
 
@@ -2671,17 +2706,23 @@ void drbd_init_set_defaults(struct drbd_conf *mdev)
 	INIT_LIST_HEAD(&mdev->md_sync_work.list);
 	INIT_LIST_HEAD(&mdev->bm_io_work.w.list);
 	INIT_LIST_HEAD(&mdev->delay_probes);
+	INIT_LIST_HEAD(&mdev->delay_probe_work.list);
 
 	mdev->resync_work.cb  = w_resync_inactive;
 	mdev->unplug_work.cb  = w_send_write_hint;
 	mdev->md_sync_work.cb = w_md_sync;
 	mdev->bm_io_work.w.cb = w_bitmap_io;
+	mdev->delay_probe_work.cb = w_delay_probes;
 	init_timer(&mdev->resync_timer);
 	init_timer(&mdev->md_sync_timer);
+	init_timer(&mdev->delay_probe_timer);
 	mdev->resync_timer.function = resync_timer_fn;
 	mdev->resync_timer.data = (unsigned long) mdev;
 	mdev->md_sync_timer.function = md_sync_timer_fn;
 	mdev->md_sync_timer.data = (unsigned long) mdev;
+	mdev->delay_probe_timer.function = delay_probe_timer_fn;
+	mdev->delay_probe_timer.data = (unsigned long) mdev;
+
 
 	init_waitqueue_head(&mdev->misc_wait);
 	init_waitqueue_head(&mdev->state_wait);