From f0eb94d1ef693651f62256ffb2c0201c6b2977cb Mon Sep 17 00:00:00 2001
From: Frederic Robra
Date: Tue, 27 Aug 2019 12:48:58 +0200
Subject: removed bug in timeout where look was not released

---
 src/kernel/net.c | 98 ++++++++++++++++++++++++++++++++++++++++++++++++++------
 1 file changed, 89 insertions(+), 9 deletions(-)

(limited to 'src/kernel/net.c')

diff --git a/src/kernel/net.c b/src/kernel/net.c
index 07f350e..79c860f 100644
--- a/src/kernel/net.c
+++ b/src/kernel/net.c
@@ -292,6 +292,7 @@ static int dnbd3_receive_cmd_get_block_mq(struct dnbd3_sock *sock,
 	void *kaddr;
 	uint32_t tag, cookie;
 	uint16_t hwq;
+	uint32_t remaining = reply->size;
 	int result = 0;
 	uint64_t handle;
 	dnbd3_init_msghdr(msg);
@@ -306,18 +307,23 @@ static int dnbd3_receive_cmd_get_block_mq(struct dnbd3_sock *sock,
 				blk_mq_unique_tag_to_tag(tag));
 	}
 	if (!req || !blk_mq_request_started(req)) {
-		dev_err(disk_to_dev(dev->disk), "unexpected reply (%d) %p\n",
-				tag, req);
-		return -EIO;
+		error_sock(sock, "unexpected reply (%d) %p", tag, req);
+		if (req) {
+			debug_sock(sock, "requeue request");
+			dnbd3_requeue_cmd(blk_mq_rq_to_pdu(req));
+		}
+//		return -EIO;
+		goto clear_socket;
 	}
 	cmd = blk_mq_rq_to_pdu(req);
 
 	mutex_lock(&cmd->lock);
 	if (cmd->cookie != cookie) {
-		dev_err(disk_to_dev(dev->disk), "double reply on req %p, cookie %u, handle cookie %u\n",
+		error_sock(sock, "double reply on req %p, cookie %u, handle cookie %u",
 				req, cmd->cookie, cookie);
 		mutex_unlock(&cmd->lock);
-		return -EIO;
+//		return -EIO;
+		goto clear_socket;
 	}
 
 	rq_for_each_segment(bvec_inst, req, iter) {
@@ -329,13 +335,18 @@ static int dnbd3_receive_cmd_get_block_mq(struct dnbd3_sock *sock,
 		iov.iov_len = bvec->bv_len;
 		result = kernel_recvmsg(sock->sock, &msg, &iov, 1, bvec->bv_len,
 				msg.msg_flags);
+		remaining -= result;
 		if (result != bvec->bv_len) {
 			kunmap(bvec->bv_page);
 			sigprocmask(SIG_SETMASK, &oldset, NULL );
 			error_sock(sock, "could not receive from net to block layer");
 			dnbd3_requeue_cmd(cmd);
 			mutex_unlock(&cmd->lock);
-			return -EIO;
+			if (result >= 0) {
+				goto clear_socket;
+			} else {
+				return result;
+			}
 		}
 		kunmap(bvec->bv_page);
 
@@ -344,6 +355,32 @@ static int dnbd3_receive_cmd_get_block_mq(struct dnbd3_sock *sock,
 	mutex_unlock(&cmd->lock);
 	dnbd3_end_cmd(cmd, 0);
 	return result;
+clear_socket:
+	warn_sock(sock, "caught an error while receiving block, clearing buffer");
+	char *buf = kmalloc(RTT_BLOCK_SIZE, GFP_KERNEL);
+	if (!buf) {
+		error_sock(sock, "kmalloc failed");
+		return -EIO;
+	}
+
+	iov.iov_base = buf;
+	iov.iov_len = RTT_BLOCK_SIZE;
+	while (remaining > 0) {
+		result = kernel_recvmsg(sock->sock, &msg, &iov, 1, iov.iov_len,
+				msg.msg_flags);
+		if (result <= 0) {
+			goto error;
+		}
+		remaining -= result;
+	}
+
+	debug_sock(sock, "cleared buffer %d bytes, reply size is %d", result,
+			reply->size);
+error:
+	if (buf) {
+		kfree(buf);
+	}
+	return -EIO;
 }
 
 
@@ -449,6 +486,7 @@ consume_payload:
 			mutex_unlock(&dev->device_lock);
 			return result;
 		}
+		remaining -= result;
 	}
 	mutex_unlock(&dev->device_lock);
 	return result;
@@ -684,7 +722,7 @@ error:
 			/* discovery takes care of to many failures */
 			sock->server->failures++;
 			warn_sock(sock, "receive error happened %d, total failures %d",
-					result, sock->server->failures);
+ 					result, sock->server->failures);
 		}
 		debug_sock(sock, "receive completed, waiting for next receive");
 	}
@@ -749,6 +787,34 @@ static struct dnbd3_server **dnbd3_sort_server(struct dnbd3_device *dev) {
 	return sorted_servers;
 }
 
+static int dnbd3_panic_connect(struct dnbd3_device *dev)
+{
+	struct dnbd3_server *working = NULL;
+	int i;
+	for (i = 0; i < NUMBER_CONNECTIONS; i++) {
+		if (dnbd3_is_sock_alive(dev->socks[i])) {
+			working = dev->socks[i].server;
+		}
+	}
+	if (working == NULL) {
+		for (i = 0; i < NUMBER_SERVERS; i++) {
+			if (!dnbd3_socket_connect(&dev->socks[0],
+					&dev->alt_servers[i])) {
+				working = &dev->alt_servers[i];
+			}
+		}
+	}
+	if (working == NULL) {
+		return -EIO;
+	}
+	for (i = 0; i < NUMBER_CONNECTIONS; i++) {
+		if (dev->socks[i].server != working) {
+			dnbd3_socket_connect(&dev->socks[i], working);
+		}
+	}
+	return 0;
+}
+
 /**
  * dnbd3_adjust_connections - create a connection plan and connect
  * @dev: the dnbd3 device
@@ -842,7 +908,13 @@ static void dnbd3_panic_worker(struct work_struct *work)
 				sock_alive);
 
 		mutex_lock(&dev->device_lock);
-		dnbd3_adjust_connections(dev);
+		if (dnbd3_adjust_connections(dev)) {
+			if (dnbd3_panic_connect(dev)) {
+				error_dev(dev, "failed to connect to any server");
+				dev->connected = false;
+			}
+
+		}
 		mutex_unlock(&dev->device_lock);
 	}
 }
@@ -1043,7 +1115,13 @@ static void dnbd3_discovery_worker(struct work_struct *work)
 
 
 	mutex_lock(&dev->device_lock);
-	dnbd3_adjust_connections(dev);
+	if (dnbd3_adjust_connections(dev)) {
+		if (dnbd3_panic_connect(dev)) {
+			error_dev(dev, "failed to connect to any server");
+			dev->connected = false;
+		}
+
+	}
 	mutex_unlock(&dev->device_lock);
 
 	dev->discovery_count++;
@@ -1283,6 +1361,7 @@ int dnbd3_net_connect(struct dnbd3_device *dev)
 		dnbd3_net_disconnect(dev);
 		return -ENOENT;
 	}
+	dev->connected = true;
 
 	debug_dev(dev, "connected, starting workers");
 	INIT_WORK(&dev->discovery_worker, dnbd3_discovery_worker);
@@ -1323,6 +1402,7 @@ int dnbd3_net_disconnect(struct dnbd3_device *dev)
 			}
 		}
 	}
+	dev->connected = false;
 	return result;
 }
 
-- 
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