From 27784cd0f009f1750e9ad213b1c0910b98ffdb44 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Tue, 20 Apr 2021 15:49:48 +0200
Subject: [KERNEL] Improve debug output in net.c

---
 src/kernel/blk.c    |  4 ++--
 src/kernel/net.c    | 15 ++++++++++-----
 src/server/uplink.c |  1 +
 3 files changed, 13 insertions(+), 7 deletions(-)

diff --git a/src/kernel/blk.c b/src/kernel/blk.c
index 82469f4..d0a3b00 100644
--- a/src/kernel/blk.c
+++ b/src/kernel/blk.c
@@ -243,8 +243,8 @@ static int dnbd3_blk_ioctl(struct block_device *bdev, fmode_t mode, unsigned int
 						for (i = 0; i < NUMBER_SERVERS; ++i) {
 							alt_server = &dev->alt_servers[i];
 							if (is_same_server(&alt_server->host, &new_addr)) {
-								alt_server->rtts[0] = alt_server->rtts[1] = alt_server->rtts[2]
-									= alt_server->rtts[3] = 4;
+								alt_server->rtts[0] = alt_server->rtts[1]
+									= alt_server->rtts[2] = alt_server->rtts[3] = 4;
 								alt_server->best_count = 100;
 							} else {
 								alt_server->rtts[0] <<= 2;
diff --git a/src/kernel/net.c b/src/kernel/net.c
index b206d5a..0eb1d5e 100644
--- a/src/kernel/net.c
+++ b/src/kernel/net.c
@@ -471,7 +471,8 @@ static int dnbd3_net_send(void *data)
 	return 0;
 
 cleanup:
-	if (!atomic_read(&dev->connection_lock)) {
+	if (!atomic_read(&dev->connection_lock) && !kthread_should_stop()) {
+		dev_dbg(dnbd3_device_to_dev(dev), "send thread: Triggering panic mode...\n");
 		if (dev->sock)
 			kernel_sock_shutdown(dev->sock, SHUT_RDWR);
 		dev->panic = 1;
@@ -540,7 +541,6 @@ static int dnbd3_net_receive(void *data)
 				/* for all errors other than -EAGAIN, print message and abort thread */
 				if (!atomic_read(&dev->connection_lock))
 					dnbd3_dev_err_host_cur(dev, "connection to server lost (receive)\n");
-				ret = -ESHUTDOWN;
 				goto cleanup;
 			}
 		}
@@ -548,7 +548,7 @@ static int dnbd3_net_receive(void *data)
 		/* check if arrived data is valid */
 		if (ret != sizeof(dnbd3_reply)) {
 			if (!atomic_read(&dev->connection_lock))
-				dnbd3_dev_err_host_cur(dev, "recv msg header\n");
+				dnbd3_dev_err_host_cur(dev, "recv partial msg header (%d bytes)\n", ret);
 			ret = -EINVAL;
 			goto cleanup;
 		}
@@ -605,10 +605,14 @@ static int dnbd3_net_receive(void *data)
 						dnbd3_dev_dbg_host_cur(
 							dev, "remote peer has performed an orderly shutdown\n");
 						ret = 0;
+					} else if (ret < 0) {
+						if (!atomic_read(&dev->connection_lock))
+							dnbd3_dev_err_host_cur(dev,
+								"disconnect: receiving from net to block layer\n");
 					} else {
 						if (!atomic_read(&dev->connection_lock))
 							dnbd3_dev_err_host_cur(dev,
-									       "receiving from net to block layer\n");
+								"receiving from net to block layer (%d bytes)\n", ret);
 						ret = -EINVAL;
 					}
 					// Requeue request
@@ -696,7 +700,8 @@ static int dnbd3_net_receive(void *data)
 	return 0;
 
 cleanup:
-	if (!atomic_read(&dev->connection_lock)) {
+	if (!atomic_read(&dev->connection_lock) && !kthread_should_stop()) {
+		dev_dbg(dnbd3_device_to_dev(dev), "recv thread: Triggering panic mode...\n");
 		if (dev->sock)
 			kernel_sock_shutdown(dev->sock, SHUT_RDWR);
 		dev->panic = 1;
diff --git a/src/server/uplink.c b/src/server/uplink.c
index 11c9d05..4329663 100644
--- a/src/server/uplink.c
+++ b/src/server/uplink.c
@@ -973,6 +973,7 @@ static void handleReceive(dnbd3_uplink_t *uplink)
 	dnbd3_reply_t inReply;
 	int ret;
 	assert_uplink_thread();
+	assert( uplink->queueLen >= 0 );
 	for (;;) {
 		ret = dnbd3_read_reply( uplink->current.fd, &inReply, false );
 		if ( unlikely( ret == REPLY_INTR ) && likely( !_shutdown && !uplink->shutdown ) ) continue;
-- 
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