From 3dcda423a8c3bfeacdb11cf164a717ce7ca78572 Mon Sep 17 00:00:00 2001
From: Frederic Robra
Date: Tue, 13 Aug 2019 15:13:04 +0200
Subject: changed strategy to connect to diffrent sockets

---
 src/kernel/core.c | 61 +++++++++++++++++++------------------------------------
 1 file changed, 21 insertions(+), 40 deletions(-)

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

diff --git a/src/kernel/core.c b/src/kernel/core.c
index 8bb23d9..6f0dab4 100644
--- a/src/kernel/core.c
+++ b/src/kernel/core.c
@@ -72,6 +72,8 @@ static void dnbd3_requeue_cmd(struct dnbd3_cmd *cmd)
 	if (!cmd->requed) {
 		cmd->requed = true;
 		blk_mq_requeue_request(req, true);
+	} else {
+		blk_mq_end_request(req, BLK_STS_IOERR);
 	}
 }
 
@@ -84,47 +86,22 @@ static int dnbd3_handle_cmd(struct dnbd3_cmd *cmd, int index)
 {
 	struct request *req = blk_mq_rq_from_pdu(cmd);
 	struct dnbd3_device *dev = cmd->dnbd3;
-	struct dnbd3_sock *sock = NULL;
-	bool first_try = true;
+	struct dnbd3_sock *sock = &dev->socks[index];
 	int ret = -1;
-	int i;
-	int sock_alive = 0;
 
-	debug_dev(dev, "handle request at position %lu, size %d, index %d",
-			blk_rq_pos(req), blk_rq_bytes(req), index);
+//	debug_dev(dev, "handle request at position %lu, size %d, index %d",
+//			blk_rq_pos(req), blk_rq_bytes(req), index);
 
-again:
 
-	for (i = 0; i < NUMBER_CONNECTIONS; i++) {
-		if (dnbd3_is_sock_alive(dev->socks[i])) {
-			if (index == sock_alive) {
-				sock = &dev->socks[i];
-			}
-			sock_alive++;
-		}
-	}
+	if (!(sock->server && sock->sock && !sock->panic)) {
+//		warn_dev(dev, "attempted send on invalid socket %d", index);
+		msleep(SOCKET_TIMEOUT_CLIENT_DATA * 1000);
 
-	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) {
-			blk_mq_update_nr_hw_queues(&dev->tag_set, sock_alive);
-			dnbd3_requeue_cmd(cmd);
-			ret = 0;
-			goto out;
-		}
-		if (first_try) {
-			debug_dev(dev, "no socket found, going to sleep");
-			msleep(SOCKET_TIMEOUT_CLIENT_DATA * 1000);
-			first_try = false;
-			goto again;
-		}
-		error_dev(dev, "failed to find a socket, end request");
-		blk_mq_end_request(req, BLK_STS_IOERR);
-		return -EINVAL;
+		dnbd3_requeue_cmd(cmd);
+		ret = 0;
+		goto out;
 	}
 
-
 	cmd->status = BLK_STS_OK;
 
 	mutex_lock(&sock->tx_lock);
@@ -164,7 +141,7 @@ static blk_status_t dnbd3_queue_rq(struct blk_mq_hw_ctx *hctx,
 	int ret;
 
 	mutex_lock(&cmd->lock);
-	cmd->requed = false;
+//	cmd->requed = false;
 
 	ret = dnbd3_handle_cmd(cmd, hctx->queue_num);
 	if (ret < 0) {
@@ -290,7 +267,6 @@ static int dnbd3_ioctl(struct block_device *bdev, fmode_t mode,
 		}
 	}
 
-	mutex_lock(&dev->device_lock);
 	switch (cmd) {
 	case IOCTL_OPEN:
 		debug_dev(dev, "ioctl open");
@@ -301,13 +277,14 @@ static int dnbd3_ioctl(struct block_device *bdev, fmode_t mode,
 		} else if (msg == NULL) {
 			result = -EINVAL;
 		} else {
+			mutex_lock(&dev->device_lock);
 			if (sizeof(msg->host) != sizeof(dev->initial_server.host)) {
 				warn_dev(dev, "odd size bug#1 triggered in ioctl");
 			}
 			memcpy(&dev->initial_server.host, &msg->host,
 					sizeof(msg->host));
 			dev->initial_server.failures = 0;
-			dnbd3_set_rtt_unreachable(&dev->initial_server)
+			dnbd3_set_rtt_unknown(&dev->initial_server)
 			dev->imgname = imgname;
 			dev->rid = msg->rid;
 			dev->use_server_provided_alts =
@@ -320,6 +297,9 @@ static int dnbd3_ioctl(struct block_device *bdev, fmode_t mode,
 					* NUMBER_SERVERS);
 			memcpy(dev->alt_servers, &dev->initial_server,
 					sizeof(dev->alt_servers[0]));
+
+			mutex_unlock(&dev->device_lock);
+
 			result = dnbd3_net_connect(dev);
 			imgname = NULL;
 		}
@@ -352,12 +332,14 @@ static int dnbd3_ioctl(struct block_device *bdev, fmode_t mode,
 		} else if (msg == NULL) {
 			result = -EINVAL;
 		} else {
+			mutex_lock(&dev->device_lock);
 			memcpy(&dev->new_servers[dev->new_servers_num].host,
 					&msg->host, sizeof(msg->host));
 			/* 0 = ADD, 1 = REM */
 			dev->new_servers[dev->new_servers_num].failures =
 					(cmd == IOCTL_ADD_SRV ? 0 : 1);
-			++dev->new_servers_num;
+			dev->new_servers_num++;
+			mutex_unlock(&dev->device_lock);
 			result = 0;
 		}
 		break;
@@ -372,7 +354,6 @@ static int dnbd3_ioctl(struct block_device *bdev, fmode_t mode,
 		result = -EIO;
 		break;
 	}
-	mutex_unlock(&dev->device_lock);
 error:
 	if (msg) kfree(msg);
 	if (imgname) kfree(imgname);
@@ -435,7 +416,7 @@ int dnbd3_add_device(struct dnbd3_device *dev, int minor)
 	dev->disk = disk;
 	dev->tag_set.ops = &dnbd3_mq_ops;
 	/* this can be changed later with blk_mq_update_nr_hw_queues() */
-	dev->tag_set.nr_hw_queues = 1;
+	dev->tag_set.nr_hw_queues = NUMBER_CONNECTIONS;
 	dev->tag_set.queue_depth = 128;
 	dev->tag_set.numa_node = NUMA_NO_NODE;
 	dev->tag_set.cmd_size = sizeof(struct dnbd3_cmd);
-- 
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