From 04ba582cf57deacb07884b2d26ef60a591087dd3 Mon Sep 17 00:00:00 2001
From: Frederic Robra
Date: Tue, 9 Jul 2019 12:12:55 +0200
Subject: added worker for keepalive and discovery

---
 src/kernel/core.c  |  7 +++++++
 src/kernel/dnbd3.h |  4 +++-
 src/kernel/net.c   | 16 ++++++++--------
 3 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/src/kernel/core.c b/src/kernel/core.c
index 48f809b..1b0aa46 100644
--- a/src/kernel/core.c
+++ b/src/kernel/core.c
@@ -54,6 +54,8 @@
 
 #define DNBD3_CMD_REQUEUED 1
 
+
+struct workqueue_struct *dnbd3_wq;
 DEFINE_IDR(dnbd3_index_idr);
 DEFINE_MUTEX(dnbd3_index_mutex);
 
@@ -426,6 +428,8 @@ static int __init dnbd3_init(void)
 	int i;
 	printk(KERN_DEBUG "dnbd3: starting kernel module\n");
 
+	dnbd3_wq = alloc_workqueue("kdnbd3", WQ_MEM_RECLAIM | WQ_FREEZABLE, 1);
+
 	if (max_devs < 0) {
 		printk(KERN_ERR "dnbd3: max_devs must be >= 0\n");
 		return -EINVAL;
@@ -483,6 +487,7 @@ static void dnbd3_dev_remove(struct dnbd3_device *dnbd3)
 		disk->private_data = NULL;
 		put_disk(disk);
 	}
+	mutex_destroy(&dnbd3->device_lock);
 }
 
 static void dnbd3_put(struct dnbd3_device *dnbd3)
@@ -516,6 +521,8 @@ static void __exit dnbd3_exit(void)
 
 	kfree(device);
 
+	destroy_workqueue(dnbd3_wq);
+
 	printk(KERN_INFO "dnbd3: stopped kernel module\n");
 }
 
diff --git a/src/kernel/dnbd3.h b/src/kernel/dnbd3.h
index 57f26f6..0e39dfb 100644
--- a/src/kernel/dnbd3.h
+++ b/src/kernel/dnbd3.h
@@ -33,6 +33,9 @@
 
 #define NUMBER_CONNECTIONS 4
 
+
+extern struct workqueue_struct *dnbd3_wq;
+
 typedef struct dnbd3_server {
 	dnbd3_host_t host;
 	uint64_t rtts[4];		// Last four round trip time measurements in microsecond
@@ -90,7 +93,6 @@ typedef struct dnbd3_device {
 
 	struct work_struct discovery; // if in irq and need to send request
 	struct timer_list discovery_timer;
-
 	// process
 //	struct task_struct * thread_send;
 //	struct task_struct * thread_receive;
diff --git a/src/kernel/net.c b/src/kernel/net.c
index f44925f..921f0d3 100644
--- a/src/kernel/net.c
+++ b/src/kernel/net.c
@@ -31,8 +31,8 @@
 #define dnbd3_req_op(req)             req_op(req)
 #define dnbd3_sock_create(af,type,proto,sock) sock_create_kern(&init_net, (af) == HOST_IP4 ? AF_INET : AF_INET6, type, proto, sock)
 
-#define KEEPALIVE_TIMER (TIMER_INTERVAL_KEEPALIVE_PACKET * (jiffies + HZ))
-#define DISCOVERY_TIMER (TIMER_INTERVAL_PROBE_NORMAL * (jiffies + HZ))
+#define KEEPALIVE_TIMER (jiffies + (HZ * TIMER_INTERVAL_KEEPALIVE_PACKET))
+#define DISCOVERY_TIMER (jiffies + (HZ * TIMER_INTERVAL_PROBE_NORMAL))
 
 #define init_msghdr(h) do { \
         h.msg_name = NULL; \
@@ -43,6 +43,7 @@
 	} while (0)
 
 
+
 static void printHost(struct dnbd3_host_t *host, char *msg)
 {
 	if (host->type == HOST_IP4) {
@@ -239,8 +240,8 @@ error:
 void dnbd3_keepalive(struct timer_list *arg)
 {
 	struct dnbd3_sock *sock = container_of(arg, struct dnbd3_sock, keepalive_timer);
-	printk(KERN_DEBUG "dnbd3: schedule keepalive\n");
 //	schedule_work(&sock->keepalive);
+	queue_work(dnbd3_wq, &sock->keepalive);
 	sock->keepalive_timer.expires = KEEPALIVE_TIMER;
 	add_timer(&sock->keepalive_timer);
 }
@@ -249,6 +250,7 @@ static void keepalive(struct work_struct *work)
 {
 	struct dnbd3_sock *sock = container_of(work, struct dnbd3_sock, keepalive);
 	struct request *req;
+	printk(KERN_DEBUG "dnbd3: starting keepalive worker\n");
 	mutex_lock(&sock->lock);
 	req = kmalloc(sizeof(struct request), GFP_ATOMIC );
 	// send keepalive
@@ -266,8 +268,7 @@ static void keepalive(struct work_struct *work)
 void dnbd3_discovery(struct timer_list *arg)
 {
 	struct dnbd3_device *dev = container_of(arg, struct dnbd3_device, discovery_timer);
-	printk(KERN_DEBUG "dnbd3: schedule discovery\n");
-//	schedule_work(&dev->discovery);
+	queue_work(dnbd3_wq, &dev->discovery);
 	dev->discovery_timer.expires = DISCOVERY_TIMER;
 	add_timer(&dev->discovery_timer);
 }
@@ -277,12 +278,13 @@ static void discovery(struct work_struct *work)
 	struct dnbd3_device *dev = container_of(work, struct dnbd3_device, discovery);
 	dnbd3_sock *sock = &dev->socks[0]; // we use the first sock for discovery
 	struct request *req;
+	printk(KERN_DEBUG "dnbd3: starting discovery worker\n");
 	mutex_lock(&sock->lock);
 	req = kmalloc(sizeof(struct request), GFP_ATOMIC );
 	// send keepalive
 	if (req) {
 		dnbd3_cmd_to_priv(req, CMD_GET_SERVERS);
-		dnbd3_send_request(NULL, sock, req); // we do not need the device for keepalive
+		dnbd3_send_request(dev, sock, req); // we do not need the device for keepalive
 		kfree(req);
 	} else {
 		printk(KERN_WARNING "dnbd3: could not create get servers request\n");
@@ -468,7 +470,6 @@ static int dnbd3_socket_disconnect(dnbd3_device *dev, dnbd3_sock *sock)
 
 	// clear heartbeat timer
 	del_timer_sync(&sock->keepalive_timer);
-//	destroy_workqueue(&sock->keepalive);
 
 	if (sock->sock) {
 		kernel_sock_shutdown(sock->sock, SHUT_RDWR);
@@ -490,7 +491,6 @@ int dnbd3_net_disconnect(struct dnbd3_device *dev)
 	int i;
 	int result;
 	del_timer_sync(&dev->discovery_timer);
-//	destroy_workqueue(&dev->discovery);
 	for (i = 0; i < NUMBER_CONNECTIONS; i++) {
 		if (dev->socks[i].sock) {
 			if (dnbd3_socket_disconnect(dev, &dev->socks[i])) {
-- 
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