diff --git a/drivers/block/drbd/drbd_int.h b/drivers/block/drbd/drbd_int.h
index 819f9d0bc8756ff2c3fdc23a62b27b5d6dab35ea..74a7d0b70e2cc6b0647750572729da496a497daf 100644
--- a/drivers/block/drbd/drbd_int.h
+++ b/drivers/block/drbd/drbd_int.h
@@ -745,6 +745,8 @@ struct drbd_connection {
 	unsigned current_tle_writes;	/* writes seen within this tl epoch */
 
 	unsigned long last_reconnect_jif;
+	/* empty member on older kernels without blk_start_plug() */
+	struct blk_plug receiver_plug;
 	struct drbd_thread receiver;
 	struct drbd_thread worker;
 	struct drbd_thread ack_receiver;
@@ -1131,7 +1133,8 @@ extern void conn_send_sr_reply(struct drbd_connection *connection, enum drbd_sta
 extern int drbd_send_rs_deallocated(struct drbd_peer_device *, struct drbd_peer_request *);
 extern void drbd_backing_dev_free(struct drbd_device *device, struct drbd_backing_dev *ldev);
 extern void drbd_device_cleanup(struct drbd_device *device);
-void drbd_print_uuids(struct drbd_device *device, const char *text);
+extern void drbd_print_uuids(struct drbd_device *device, const char *text);
+extern void drbd_queue_unplug(struct drbd_device *device);
 
 extern void conn_md_sync(struct drbd_connection *connection);
 extern void drbd_md_write(struct drbd_device *device, void *buffer);
diff --git a/drivers/block/drbd/drbd_main.c b/drivers/block/drbd/drbd_main.c
index e2ed28d45ce12ce00725cd52da4f18f38daf54fd..a3b2ee74bba98ede9340dc29de7332b9c4f0bb08 100644
--- a/drivers/block/drbd/drbd_main.c
+++ b/drivers/block/drbd/drbd_main.c
@@ -1952,6 +1952,19 @@ static void drbd_release(struct gendisk *gd, fmode_t mode)
 	mutex_unlock(&drbd_main_mutex);
 }
 
+/* need to hold resource->req_lock */
+void drbd_queue_unplug(struct drbd_device *device)
+{
+	if (device->state.pdsk >= D_INCONSISTENT && device->state.conn >= C_CONNECTED) {
+		D_ASSERT(device, device->state.role == R_PRIMARY);
+		if (test_and_clear_bit(UNPLUG_REMOTE, &device->flags)) {
+			drbd_queue_work_if_unqueued(
+				&first_peer_device(device)->connection->sender_work,
+				&device->unplug_work);
+		}
+	}
+}
+
 static void drbd_set_defaults(struct drbd_device *device)
 {
 	/* Beware! The actual layout differs
diff --git a/drivers/block/drbd/drbd_receiver.c b/drivers/block/drbd/drbd_receiver.c
index ece6e5d7dc3f24f763718c0145b0f30b612ec517..1b3f439a3b237d37e4e32219eb45696d6e1dce27 100644
--- a/drivers/block/drbd/drbd_receiver.c
+++ b/drivers/block/drbd/drbd_receiver.c
@@ -1194,6 +1194,14 @@ static int decode_header(struct drbd_connection *connection, void *header, struc
 	return 0;
 }
 
+static void drbd_unplug_all_devices(struct drbd_connection *connection)
+{
+	if (current->plug == &connection->receiver_plug) {
+		blk_finish_plug(&connection->receiver_plug);
+		blk_start_plug(&connection->receiver_plug);
+	} /* else: maybe just schedule() ?? */
+}
+
 static int drbd_recv_header(struct drbd_connection *connection, struct packet_info *pi)
 {
 	void *buffer = connection->data.rbuf;
@@ -1209,6 +1217,36 @@ static int drbd_recv_header(struct drbd_connection *connection, struct packet_in
 	return err;
 }
 
+static int drbd_recv_header_maybe_unplug(struct drbd_connection *connection, struct packet_info *pi)
+{
+	void *buffer = connection->data.rbuf;
+	unsigned int size = drbd_header_size(connection);
+	int err;
+
+	err = drbd_recv_short(connection->data.socket, buffer, size, MSG_NOSIGNAL|MSG_DONTWAIT);
+	if (err != size) {
+		/* If we have nothing in the receive buffer now, to reduce
+		 * application latency, try to drain the backend queues as
+		 * quickly as possible, and let remote TCP know what we have
+		 * received so far. */
+		if (err == -EAGAIN) {
+			drbd_tcp_quickack(connection->data.socket);
+			drbd_unplug_all_devices(connection);
+		}
+		if (err > 0) {
+			buffer += err;
+			size -= err;
+		}
+		err = drbd_recv_all_warn(connection, buffer, size);
+		if (err)
+			return err;
+	}
+
+	err = decode_header(connection, connection->data.rbuf, pi);
+	connection->last_received = jiffies;
+
+	return err;
+}
 /* This is blkdev_issue_flush, but asynchronous.
  * We want to submit to all component volumes in parallel,
  * then wait for all completions.
@@ -4882,8 +4920,8 @@ static void drbdd(struct drbd_connection *connection)
 		struct data_cmd const *cmd;
 
 		drbd_thread_current_set_cpu(&connection->receiver);
-		update_receiver_timing_details(connection, drbd_recv_header);
-		if (drbd_recv_header(connection, &pi))
+		update_receiver_timing_details(connection, drbd_recv_header_maybe_unplug);
+		if (drbd_recv_header_maybe_unplug(connection, &pi))
 			goto err_out;
 
 		cmd = &drbd_cmd_handler[pi.cmd];
@@ -5375,8 +5413,11 @@ int drbd_receiver(struct drbd_thread *thi)
 		}
 	} while (h == 0);
 
-	if (h > 0)
+	if (h > 0) {
+		blk_start_plug(&connection->receiver_plug);
 		drbdd(connection);
+		blk_finish_plug(&connection->receiver_plug);
+	}
 
 	conn_disconnect(connection);
 
diff --git a/drivers/block/drbd/drbd_req.c b/drivers/block/drbd/drbd_req.c
index 447c975f54819bed6dbd5f44d8898234e0ce9e03..5cf43f13e7eb1cf9522e89dd6e73ee9889b2174c 100644
--- a/drivers/block/drbd/drbd_req.c
+++ b/drivers/block/drbd/drbd_req.c
@@ -1279,6 +1279,56 @@ static bool may_do_writes(struct drbd_device *device)
 	return s.disk == D_UP_TO_DATE || s.pdsk == D_UP_TO_DATE;
 }
 
+struct drbd_plug_cb {
+	struct blk_plug_cb cb;
+	struct drbd_request *most_recent_req;
+	/* do we need more? */
+};
+
+static void drbd_unplug(struct blk_plug_cb *cb, bool from_schedule)
+{
+	struct drbd_plug_cb *plug = container_of(cb, struct drbd_plug_cb, cb);
+	struct drbd_resource *resource = plug->cb.data;
+	struct drbd_request *req = plug->most_recent_req;
+
+	if (!req)
+		return;
+
+	spin_lock_irq(&resource->req_lock);
+	/* In case the sender did not process it yet, raise the flag to
+	 * have it followed with P_UNPLUG_REMOTE just after. */
+	req->rq_state |= RQ_UNPLUG;
+	/* but also queue a generic unplug */
+	drbd_queue_unplug(req->device);
+	spin_unlock_irq(&resource->req_lock);
+	kref_put(&req->kref, drbd_req_destroy);
+}
+
+static struct drbd_plug_cb* drbd_check_plugged(struct drbd_resource *resource)
+{
+	/* A lot of text to say
+	 * return (struct drbd_plug_cb*)blk_check_plugged(); */
+	struct drbd_plug_cb *plug;
+	struct blk_plug_cb *cb = blk_check_plugged(drbd_unplug, resource, sizeof(*plug));
+
+	if (cb)
+		plug = container_of(cb, struct drbd_plug_cb, cb);
+	else
+		plug = NULL;
+	return plug;
+}
+
+static void drbd_update_plug(struct drbd_plug_cb *plug, struct drbd_request *req)
+{
+	struct drbd_request *tmp = plug->most_recent_req;
+	/* Will be sent to some peer.
+	 * Remember to tag it with UNPLUG_REMOTE on unplug */
+	kref_get(&req->kref);
+	plug->most_recent_req = req;
+	if (tmp)
+		kref_put(&tmp->kref, drbd_req_destroy);
+}
+
 static void drbd_send_and_submit(struct drbd_device *device, struct drbd_request *req)
 {
 	struct drbd_resource *resource = device->resource;
@@ -1287,6 +1337,8 @@ static void drbd_send_and_submit(struct drbd_device *device, struct drbd_request
 	bool no_remote = false;
 	bool submit_private_bio = false;
 
+	struct drbd_plug_cb *plug = drbd_check_plugged(resource);
+
 	spin_lock_irq(&resource->req_lock);
 	if (rw == WRITE) {
 		/* This may temporarily give up the req_lock,
@@ -1351,6 +1403,9 @@ static void drbd_send_and_submit(struct drbd_device *device, struct drbd_request
 			no_remote = true;
 	}
 
+	if (plug != NULL && no_remote == false)
+		drbd_update_plug(plug, req);
+
 	/* If it took the fast path in drbd_request_prepare, add it here.
 	 * The slow path has added it already. */
 	if (list_empty(&req->req_pending_master_completion))
diff --git a/drivers/block/drbd/drbd_req.h b/drivers/block/drbd/drbd_req.h
index 9e1866ab238fc8e56c3a95f6bf0f9b4acf229da3..a2254f825601890fad999d9f7876b704b4a43c4d 100644
--- a/drivers/block/drbd/drbd_req.h
+++ b/drivers/block/drbd/drbd_req.h
@@ -212,6 +212,11 @@ enum drbd_req_state_bits {
 	/* Should call drbd_al_complete_io() for this request... */
 	__RQ_IN_ACT_LOG,
 
+	/* This was the most recent request during some blk_finish_plug()
+	 * or its implicit from-schedule equivalent.
+	 * We may use it as hint to send a P_UNPLUG_REMOTE */
+	__RQ_UNPLUG,
+
 	/* The peer has sent a retry ACK */
 	__RQ_POSTPONED,
 
@@ -249,6 +254,7 @@ enum drbd_req_state_bits {
 #define RQ_WSAME           (1UL << __RQ_WSAME)
 #define RQ_UNMAP           (1UL << __RQ_UNMAP)
 #define RQ_IN_ACT_LOG      (1UL << __RQ_IN_ACT_LOG)
+#define RQ_UNPLUG          (1UL << __RQ_UNPLUG)
 #define RQ_POSTPONED	   (1UL << __RQ_POSTPONED)
 #define RQ_COMPLETION_SUSP (1UL << __RQ_COMPLETION_SUSP)
 #define RQ_EXP_RECEIVE_ACK (1UL << __RQ_EXP_RECEIVE_ACK)
diff --git a/drivers/block/drbd/drbd_worker.c b/drivers/block/drbd/drbd_worker.c
index c268d886c4f0ecaed33a2c83826be8e4725f0dc7..2745db2255ed2126df0640f940a00f92f92acd0a 100644
--- a/drivers/block/drbd/drbd_worker.c
+++ b/drivers/block/drbd/drbd_worker.c
@@ -1382,18 +1382,22 @@ static int drbd_send_barrier(struct drbd_connection *connection)
 	return conn_send_command(connection, sock, P_BARRIER, sizeof(*p), NULL, 0);
 }
 
+static int pd_send_unplug_remote(struct drbd_peer_device *pd)
+{
+	struct drbd_socket *sock = &pd->connection->data;
+	if (!drbd_prepare_command(pd, sock))
+		return -EIO;
+	return drbd_send_command(pd, sock, P_UNPLUG_REMOTE, 0, NULL, 0);
+}
+
 int w_send_write_hint(struct drbd_work *w, int cancel)
 {
 	struct drbd_device *device =
 		container_of(w, struct drbd_device, unplug_work);
-	struct drbd_socket *sock;
 
 	if (cancel)
 		return 0;
-	sock = &first_peer_device(device)->connection->data;
-	if (!drbd_prepare_command(first_peer_device(device), sock))
-		return -EIO;
-	return drbd_send_command(first_peer_device(device), sock, P_UNPLUG_REMOTE, 0, NULL, 0);
+	return pd_send_unplug_remote(first_peer_device(device));
 }
 
 static void re_init_if_first_write(struct drbd_connection *connection, unsigned int epoch)
@@ -1455,6 +1459,7 @@ int w_send_dblock(struct drbd_work *w, int cancel)
 	struct drbd_device *device = req->device;
 	struct drbd_peer_device *const peer_device = first_peer_device(device);
 	struct drbd_connection *connection = peer_device->connection;
+	bool do_send_unplug = req->rq_state & RQ_UNPLUG;
 	int err;
 
 	if (unlikely(cancel)) {
@@ -1470,6 +1475,9 @@ int w_send_dblock(struct drbd_work *w, int cancel)
 	err = drbd_send_dblock(peer_device, req);
 	req_mod(req, err ? SEND_FAILED : HANDED_OVER_TO_NETWORK);
 
+	if (do_send_unplug && !err)
+		pd_send_unplug_remote(peer_device);
+
 	return err;
 }
 
@@ -1484,6 +1492,7 @@ int w_send_read_req(struct drbd_work *w, int cancel)
 	struct drbd_device *device = req->device;
 	struct drbd_peer_device *const peer_device = first_peer_device(device);
 	struct drbd_connection *connection = peer_device->connection;
+	bool do_send_unplug = req->rq_state & RQ_UNPLUG;
 	int err;
 
 	if (unlikely(cancel)) {
@@ -1501,6 +1510,9 @@ int w_send_read_req(struct drbd_work *w, int cancel)
 
 	req_mod(req, err ? SEND_FAILED : HANDED_OVER_TO_NETWORK);
 
+	if (do_send_unplug && !err)
+		pd_send_unplug_remote(peer_device);
+
 	return err;
 }