From 220e8d7720138f9de10072ba4d9596afa138235b Mon Sep 17 00:00:00 2001
From: Frederic Robra
Date: Wed, 4 Sep 2019 15:24:44 +0200
Subject: removed initial server and removed replacement of alt servers

---
 src/kernel/core.c  | 11 ++++-------
 src/kernel/dnbd3.h |  3 +--
 src/kernel/net.c   | 58 ++++++++++++++++--------------------------------------
 src/kernel/sysfs.c | 18 -----------------
 4 files changed, 22 insertions(+), 68 deletions(-)

diff --git a/src/kernel/core.c b/src/kernel/core.c
index 2f7ddcb..6e9ce2b 100644
--- a/src/kernel/core.c
+++ b/src/kernel/core.c
@@ -132,13 +132,9 @@ static int dnbd3_ioctl(struct block_device *bdev, fmode_t mode,
 			result = -EINVAL;
 		} else {
 			mutex_lock(&dev->device_lock);
-			if (sizeof(msg->host) != sizeof(dev->initial_server.host)) {
+			if (sizeof(msg->host) != sizeof(dnbd3_host_t)) {
 				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_unknown(&dev->initial_server)
 			dev->imgname = imgname;
 			dev->rid = msg->rid;
 			dev->use_server_provided_alts =
@@ -149,8 +145,9 @@ static int dnbd3_ioctl(struct block_device *bdev, fmode_t mode,
 			 */
 			memset(dev->alt_servers, 0, sizeof(dev->alt_servers[0])
 					* NUMBER_SERVERS);
-			memcpy(dev->alt_servers, &dev->initial_server,
-					sizeof(dev->alt_servers[0]));
+
+			memcpy(&dev->alt_servers[0].host, &msg->host,
+					sizeof(msg->host));
 
 			if (old_msg || msg->number_connections == 0) {
 				dev->number_connections = 4;
diff --git a/src/kernel/dnbd3.h b/src/kernel/dnbd3.h
index 6d8ceb2..e8eab9b 100644
--- a/src/kernel/dnbd3.h
+++ b/src/kernel/dnbd3.h
@@ -144,8 +144,7 @@ struct dnbd3_device {
 	uint8_t number_connections;
 	struct dnbd3_sock *socks;
 	char *imgname;
-	struct dnbd3_server initial_server;
-	struct dnbd3_server alt_servers[NUMBER_SERVERS];//TODO just add server to list do not remove
+	struct dnbd3_server alt_servers[NUMBER_SERVERS];
 	int new_servers_num;
 	dnbd3_server_entry_t new_servers[NUMBER_SERVERS];
 	bool update_available;
diff --git a/src/kernel/net.c b/src/kernel/net.c
index 061deb1..8f71b5a 100644
--- a/src/kernel/net.c
+++ b/src/kernel/net.c
@@ -291,32 +291,6 @@ static int dnbd3_compare_plan(const void *lhs, const void *rhs)
 	return l - r;
 }
 
-static void dnbd3_lock_all_socks(struct dnbd3_device *dev)
-{
-	int i;
-	for (i = 0; i < dev->number_connections; i++) {
-		mutex_lock(&dev->socks[i].tx_lock);
-	}
-}
-
-static void dnbd3_unlock_all_socks(struct dnbd3_device *dev)
-{
-	int i;
-	for (i = 0; i < dev->number_connections; i++) {
-		mutex_unlock(&dev->socks[i].tx_lock);
-	}
-}
-
-static void dnbd3_print_conenction_plan(struct dnbd3_device *dev,
-		struct dnbd3_server **plan)
-{
-	int i;
-	debug_dev(dev, "connection plan:");
-	for (i = 0; i < dev->number_connections; i++) {
-		debug_server(dev, plan[i], "server %d with avg rtt %llu:",
-				i, plan[i]->avg_rtt);
-	}
-}
 
 /**
  * dnbd3_adjust_connections - create a connection plan and connect
@@ -361,9 +335,17 @@ static int dnbd3_adjust_connections(struct dnbd3_device *dev) {
 
 		sort(plan, dev->number_connections, sizeof(struct dnbd3_server *),
 			&dnbd3_compare_plan, NULL);
-		dnbd3_print_conenction_plan(dev, plan);
 
-		dnbd3_lock_all_socks(dev);
+		/* lock all mutex at once, so nothing can be send */
+		debug_dev(dev, "connection plan:");
+		for (i = 0; i < dev->number_connections; i++) {
+			debug_server(dev, plan[i],
+					"server %d with avg rtt %llu:",
+					i, plan[i]->avg_rtt);
+
+			mutex_lock(&dev->socks[i].tx_lock);
+		}
+
 		alive = 0;
 		for (i = 0; i < dev->number_connections; i++) {
 			if (plan[i] != dev->socks[i].server ||
@@ -379,8 +361,9 @@ static int dnbd3_adjust_connections(struct dnbd3_device *dev) {
 			} else {
 				alive++;
 			}
+			mutex_unlock(&dev->socks[i].tx_lock);
 		}
-		dnbd3_unlock_all_socks(dev);
+
 		if (alive == 0) {
 			return -EIO;
 		}
@@ -540,10 +523,8 @@ static void dnbd3_merge_new_server(struct dnbd3_device *dev,
 		dnbd3_server_entry_t *new_server)
 {
 	int i;
-	struct dnbd3_server *existing_server, *free_server, *failed_server;
-	existing_server = NULL;
-	free_server = NULL;
-	failed_server = NULL;
+	struct dnbd3_server *existing_server = NULL;
+	struct dnbd3_server *free_server = NULL;
 
 	/* find servers in alternative servers */
 	for (i = 0; i < NUMBER_SERVERS; i++) {
@@ -557,8 +538,6 @@ static void dnbd3_merge_new_server(struct dnbd3_device *dev,
 			existing_server = &dev->alt_servers[i];
 		} else if (dev->alt_servers[i].host.type == 0) {
 			free_server = &dev->alt_servers[i];
-		} else if (dev->alt_servers[i].failures > 20) {
-			failed_server = &dev->alt_servers[i];
 		}
 	}
 
@@ -566,19 +545,16 @@ static void dnbd3_merge_new_server(struct dnbd3_device *dev,
 		if (new_server->failures == 1) { /* remove is requested */
 			info_server(dev, new_server,
 					"remove server is requested");
-			// adjust connection will remove it later
+			/* adjust connection will remove it later */
 			existing_server->host.type = 0;
 			dnbd3_set_rtt_unreachable(existing_server);
 		}
-//		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;
-		free_server = failed_server;
 	} else {
+		warn_dev(dev, "reached the maximum of %d servers",
+				NUMBER_SERVERS);
 		/* no server found to replace */
 		return;
 	}
diff --git a/src/kernel/sysfs.c b/src/kernel/sysfs.c
index bd23845..a780a21 100644
--- a/src/kernel/sysfs.c
+++ b/src/kernel/sysfs.c
@@ -29,16 +29,6 @@
 #define MIN(a,b) ((a) < (b) ? (a) : (b))
 #endif
 
-ssize_t show_initial_server_addr(char *buf, struct dnbd3_device *dev)
-{
-	if (dev->initial_server.host.type == HOST_IP4)
-		return MIN(snprintf(buf, PAGE_SIZE, "%pI4,%d\n", dev->initial_server.host.addr, (int)ntohs(dev->initial_server.host.port)), PAGE_SIZE);
-	else if (dev->initial_server.host.type == HOST_IP6)
-		return MIN(snprintf(buf, PAGE_SIZE, "%pI6,%d\n", dev->initial_server.host.addr, (int)ntohs(dev->initial_server.host.port)), PAGE_SIZE);
-	*buf = '\0';
-	return 0;
-}
-
 ssize_t show_connected_servers(char *buf, struct dnbd3_device *dev)
 {
 	int i, size = PAGE_SIZE, ret;
@@ -136,13 +126,6 @@ ssize_t show_update_available(char *buf, struct dnbd3_device *dev)
 	return MIN(snprintf(buf, PAGE_SIZE, "%d\n", dev->update_available), PAGE_SIZE);
 }
 
-struct device_attr_t initial_server =
-{
-	.attr = {.name = "initial_server", .mode = 0444 },
-	.show   = show_initial_server_addr,
-	.store  = NULL,
-};
-
 struct device_attr_t connected_server =
 {
 	.attr = {.name = "connected_server", .mode = 0444 },
@@ -200,7 +183,6 @@ ssize_t device_show(struct kobject *kobj, struct attribute *attr, char *buf)
 
 struct attribute *device_attrs[] =
 {
-	&initial_server.attr,
 	&connected_server.attr,
 //	&cur_server_rtt.attr,
 	&alt_server_num.attr,
-- 
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