From ec6c0ce8b1af8d9c36f4ec87cd384365cb2d9012 Mon Sep 17 00:00:00 2001
From: Frederic Robra
Date: Wed, 6 Nov 2019 20:23:47 +0100
Subject: removed bug when sending and at the same time socket closes down

---
 src/kernel/core.c     | 5 ++---
 src/kernel/dnbd3.h    | 1 +
 src/kernel/mq.c       | 2 +-
 src/kernel/net-txrx.c | 2 +-
 src/kernel/net.c      | 9 +++++----
 5 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/src/kernel/core.c b/src/kernel/core.c
index 874980b..4ef7221 100644
--- a/src/kernel/core.c
+++ b/src/kernel/core.c
@@ -272,7 +272,6 @@ int dnbd3_add_device(struct dnbd3_device *dev, int minor)
 	if (err < 0) {
 		goto out_free_disk;
 	}
-
 	dev->minor = minor;
 	dev->disk = disk;
 	dev->tag_set.ops = &dnbd3_mq_ops;
@@ -286,9 +285,9 @@ int dnbd3_add_device(struct dnbd3_device *dev, int minor)
 	dev->tag_set.driver_data = dev;
 
 	err = blk_mq_alloc_tag_set(&dev->tag_set);
-	if (err)
+	if (err) {
 		goto out_free_idr;
-
+	}
 	q = blk_mq_init_queue(&dev->tag_set);
 	if (IS_ERR(q)) {
 		err = PTR_ERR(q);
diff --git a/src/kernel/dnbd3.h b/src/kernel/dnbd3.h
index 437edec..f8d4bae 100644
--- a/src/kernel/dnbd3.h
+++ b/src/kernel/dnbd3.h
@@ -163,6 +163,7 @@ struct dnbd3_device {
  * @dnbd3: the dnbd3 device this command belongs to
  * @lock: mutex to lock the cmd
  * @cookie: the cookie of the command, this is set by the socket when sending
+ * @index: the queue_num of the requests this command belongs to
  * @requed: 'true' if the command is requed
  */
 struct dnbd3_cmd {
diff --git a/src/kernel/mq.c b/src/kernel/mq.c
index 34a8a5b..5b480de 100644
--- a/src/kernel/mq.c
+++ b/src/kernel/mq.c
@@ -109,7 +109,7 @@ void dndb3_reque_busy_requests(struct dnbd3_sock *sock)
 void dnbd3_requeue_cmd(struct dnbd3_cmd *cmd)
 {
 	struct request *req = blk_mq_rq_from_pdu(cmd);
-	if (!cmd->requed) {
+	if (!cmd->requed && blk_queued_rq(req)) {
 		cmd->requed = true;
 		blk_mq_requeue_request(req, true);
 	}
diff --git a/src/kernel/net-txrx.c b/src/kernel/net-txrx.c
index a0d75bb..4ca3fa5 100644
--- a/src/kernel/net-txrx.c
+++ b/src/kernel/net-txrx.c
@@ -122,7 +122,7 @@ int dnbd3_send_request(struct dnbd3_sock *sock, struct request *req,
 
 	switch (req_op(req)) {
 	case REQ_OP_READ:
-		debug_sock(sock, "request operation read %p", req);
+//		debug_sock(sock, "request operation read %p", req);
 		request.cmd = CMD_GET_BLOCK;
 		request.offset = blk_rq_pos(req) << 9; // * 512
 		request.size = blk_rq_bytes(req);
diff --git a/src/kernel/net.c b/src/kernel/net.c
index a837702..801c15c 100644
--- a/src/kernel/net.c
+++ b/src/kernel/net.c
@@ -81,10 +81,9 @@ static void dnbd3_timer(struct timer_list *arg)
 	}
 
 	/* start after 2 seconds */
-	if (dev->timer_count % TIMER_INTERVAL_PROBE_NORMAL == 2) {
+	if (!busy && dev->timer_count % TIMER_INTERVAL_PROBE_NORMAL == 2) {
 		queue_work(dnbd3_wq, &dev->discovery_worker);
 	}
-
 	dev->timer_count++;
 	dev->timer.expires = jiffies + HZ;
 	add_timer(&dev->timer);
@@ -108,11 +107,9 @@ static void dnbd3_receive_worker(struct work_struct *work)
 		result = dnbd3_receive_cmd(sock, &reply);
 		if (result == -EAGAIN) {
 			continue;
-
 		} else if (result <= 0) {
 			error_sock(sock, "connection to server lost %d", result);
 			goto error;
-
 		}
 
 		switch (reply.cmd) {
@@ -162,6 +159,10 @@ static void dnbd3_receive_worker(struct work_struct *work)
 error:
 		if (result == 0) {
 			info_sock(sock, "result is 0, socket seems to be down");
+			/* be sure nobody is sending on the socket */
+			while (unlikely(sock->pending)) {
+				msleep(50);
+			}
 			dnbd3_sock_release(sock);
 			break;
 		} else if (result < 0) {
-- 
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