From 79d36aa260f49716ede72cd6bea5cf10aa688651 Mon Sep 17 00:00:00 2001
From: Simon Rettberg
Date: Tue, 17 Mar 2020 13:26:06 +0100
Subject: [SERVER] Make sure bgrWindowSize doesn't overwhelm uplink queue

---
 src/server/globals.c | 4 ++++
 src/server/uplink.c  | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/src/server/globals.c b/src/server/globals.c
index 98e0ddb..9914f89 100644
--- a/src/server/globals.c
+++ b/src/server/globals.c
@@ -138,6 +138,10 @@ void globals_loadConfig()
 	}
 	if ( _bgrWindowSize < 1 ) {
 		_bgrWindowSize = 1;
+	} else if ( _bgrWindowSize > UPLINK_MAX_QUEUE - 10 ) {
+		_bgrWindowSize = UPLINK_MAX_QUEUE - 10;
+		logadd( LOG_MINOR, "Limiting bgrWindowSize to %d, because of UPLINK_MAX_QUEUE",
+				_bgrWindowSize );
 	}
 	// Dump config as interpreted
 	char buffer[2000];
diff --git a/src/server/uplink.c b/src/server/uplink.c
index 9bf48d3..af854d6 100644
--- a/src/server/uplink.c
+++ b/src/server/uplink.c
@@ -786,6 +786,8 @@ static bool sendReplicationRequest(dnbd3_uplink_t *uplink)
 	const int lastBlockIndex = mapBytes - 1;
 	for ( int bc = 0; bc < numNewRequests; ++bc ) {
 		int endByte;
+		if ( UPLINK_MAX_QUEUE - uplink->queueLen < 10 )
+			break; // Don't overload queue
 		if ( _backgroundReplication == BGR_FULL ) { // Full mode: consider all blocks
 			endByte = uplink->nextReplicationIndex + mapBytes;
 		} else { // Hashblock based: Only look for match in current hash block
-- 
cgit v1.2.3-55-g7522