From 8a71a522f69058af76c84d4157555f82074f1ade Mon Sep 17 00:00:00 2001
From: Frederic Robra
Date: Sun, 11 Aug 2019 16:07:05 +0200
Subject: added todos

---
 src/kernel/core.c  |  2 +-
 src/kernel/dnbd3.h | 10 ++++++++--
 src/kernel/net.c   | 26 ++++++++++++++++++++++++--
 3 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/src/kernel/core.c b/src/kernel/core.c
index cc19b58..8bb23d9 100644
--- a/src/kernel/core.c
+++ b/src/kernel/core.c
@@ -104,7 +104,7 @@ again:
 		}
 	}
 
-	if (!sock) {
+	if (!sock) { // TODO let the mq queues be the same number as NUMBER_CONNECTIONS than handle them
 		warn_dev(dev, "index is %d but no socket was found", index);
 		dev_err_ratelimited(disk_to_dev(dev->disk), "attempted send on invalid socket\n");
 		if (sock_alive > 0) {
diff --git a/src/kernel/dnbd3.h b/src/kernel/dnbd3.h
index edd19e1..2c3ec39 100644
--- a/src/kernel/dnbd3.h
+++ b/src/kernel/dnbd3.h
@@ -55,6 +55,11 @@
 #define DEBUG_FILE 1
 
 
+//TODO test with ip tables regel. jedes x paket an port 58007 zerstoeren
+// iptables -A OUTPUT -p tcp -m statistic --mode random --probability 0.1 -j REJECT  --reject-with tcp-reset
+//TODO setup mit 2 vms eine langsam eine schnell tc (traffic control)
+// -> geschwindigkkeit sollte in Richtung schnellen VM gehen mit 2 Queues
+
 extern struct workqueue_struct *dnbd3_wq;
 
 /**
@@ -68,7 +73,7 @@ struct dnbd3_server {
 	dnbd3_host_t host;
 	uint64_t rtts[4];
 	uint16_t protocol_version;
-	uint8_t failures;
+	uint16_t failures; // TODO failures runterzaehlen wenn wieder verbindung moeglich, seltener messen bei hohem failure count
 
 	/*
 	 * TODO would this help?
@@ -163,7 +168,7 @@ struct dnbd3_device {
 	struct dnbd3_sock socks[NUMBER_CONNECTIONS];
 	char *imgname;
 	struct dnbd3_server initial_server;
-	struct dnbd3_server alt_servers[NUMBER_SERVERS];
+	struct dnbd3_server alt_servers[NUMBER_SERVERS];//TODO just add server to list do not remove
 	int new_servers_num;
 	dnbd3_server_entry_t new_servers[NUMBER_SERVERS];
 	bool update_available;
@@ -188,6 +193,7 @@ struct dnbd3_device {
  * @requed: 'true' if the command is requed
  */
 struct dnbd3_cmd {
+	//TODO do we want the socket here (index)?
 	struct dnbd3_device *dnbd3;
 	struct mutex lock;
 	uint32_t cookie;
diff --git a/src/kernel/net.c b/src/kernel/net.c
index 2d0b6ad..5478e95 100644
--- a/src/kernel/net.c
+++ b/src/kernel/net.c
@@ -208,6 +208,10 @@ int dnbd3_send_request(struct dnbd3_sock *sock, struct request *req,
 	result = kernel_sendmsg(sock->sock, &msg, iov, iov_num, lng);
 	if (result != lng) {
 		error_sock(sock, "connection to server lost");
+		if (cmd) {
+			blk_mq_requeue_request(req, true);
+		}
+		sock->panic = true;
 		sock->server->failures++;
 		goto error;
 	}
@@ -823,7 +827,7 @@ static void dnbd3_adjust_connections(struct dnbd3_device *dev) {
 	uint64_t best_rtt = RTT_UNREACHABLE;
 	struct dnbd3_server *server, *existing_server;
 
-	/* connect empty sockets */
+	/* connect empty sockets */ //TODO check if panic worker connects at the same time, than we would have a problem
 	sock_alive = 0;
 	for (i = 0; i < NUMBER_CONNECTIONS; i++) {
 		if (!dnbd3_is_sock_alive(dev->socks[i])) {
@@ -1094,6 +1098,7 @@ static void dnbd3_merge_new_server(struct dnbd3_device *dev,
 //		existing_server->failures = 0; // reset failure count
 		return;
 	} else if (free_server) {
+		//TODO disconnect the server if it is connected
 		free_server->host = new_server->host;
 	} else if (failed_server) {
 		failed_server->host = new_server->host;
@@ -1357,6 +1362,13 @@ error:
 	return result;
 }
 
+static void dnbd3_clear_req(struct request *req, void *data, bool reserved)
+{
+	struct dnbd3_cmd *cmd = blk_mq_rq_to_pdu(req);
+
+	cmd->status = BLK_STS_IOERR;
+	blk_mq_complete_request(req);
+}
 
 /**
  * dnbd3_socket_disconnect - disconnect a socket or server
@@ -1406,7 +1418,6 @@ static int dnbd3_socket_disconnect(struct dnbd3_sock *sock)
 	}
 	mutex_unlock(&sock->tx_lock);
 	mutex_destroy(&sock->tx_lock);
-	blk_mq_update_nr_hw_queues(&dev->tag_set, sock_alive - 1);
 
 	cancel_work_sync(&sock->receive_worker);
 
@@ -1414,6 +1425,17 @@ static int dnbd3_socket_disconnect(struct dnbd3_sock *sock)
 		sock_release(sock->sock);
 		sock->sock = NULL;
 	}
+	debug_sock(sock, "update nr hw queues to %d", sock_alive -1);
+//	blk_mq_quiesce_queue(dev->disk->queue);
+//	debug_sock(sock, "busy iter");
+//	blk_mq_tagset_busy_iter(&dev->tag_set, dnbd3_clear_req, NULL);
+//	debug_sock(sock, "update");
+	//TODO can we just stop the failed queue?
+	blk_mq_update_nr_hw_queues(&dev->tag_set, sock_alive - 1);
+//	debug_sock(sock, "unquisco");
+//	blk_mq_unquiesce_queue(dev->disk->queue);
+//	debug_sock(sock, "donee");
+
 	sock->server = NULL;
 	sock->panic = false;
 	return 0;
-- 
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