Don't close the same file descriptor more than once.

src/client.c

@@ -490,11 +490,19 @@ void client_cleanup(struct client* client,
 {
 	info("client cleanup for client %p", client);
 	
-	if (client->socket) { close(client->socket); }
+	if (client->socket) { 
+		close(client->socket); 
+		client->socket = -1;
+		debug("Closed client socket fd %d", client->socket);
+	}
 	if (client->mapped) {
 		munmap(client->mapped, client->serve->size);
 	}
-	if (client->fileno) { close(client->fileno); }
+	if (client->fileno) { 
+		close(client->fileno); 
+		client->fileno = -1;
+		debug("Closed client file fd %d", client->fileno );
+	}
 
 	if ( server_io_locked( client->serve ) ) { server_unlock_io( client->serve ); }
 	if ( server_acl_locked( client->serve ) ) { server_unlock_acl( client->serve ); }
@@ -517,6 +525,7 @@ void* client_serve(void* client_uncast)
 		),
 		"Couldn't open/mmap file %s: %s", client->serve->filename, strerror( errno )
 	);
+	debug( "Opened client file fd %d", client->fileno);
 	debug("client: sending hello");
 	client_send_hello(client);
 	
@@ -530,15 +539,6 @@ void* client_serve(void* client_uncast)
 		debug("client: control arrived" );
 		server_control_arrived( client->serve );
 	}
-	else {
-		warn( "client: control transfer failed." );
-	}
-
-	FATAL_IF_NEGATIVE(
-		close(client->socket),
-		"Couldn't close socket %d", 
-		client->socket
-	);
 
 	debug("Cleaning client %p up normally in thread %p", client, pthread_self());
 	client_cleanup(client, 0);

src/mode.c

@@ -426,6 +426,7 @@ int mode_serve( int argc, char *argv[] )
 	if ( err ) { exit_err( serve_help_text ); }
 
 	flexnbd = flexnbd_create_serving( ip_addr, ip_port, file, sock, default_deny, argc - optind, argv + optind, MAX_NBD_CLIENTS );
+	info( "Serving file %s", file );
 	flexnbd_serve( flexnbd );
 	flexnbd_destroy( flexnbd );
 

src/serve.c

@@ -505,6 +505,7 @@ void accept_nbd_client(
 
 	if ( !server_should_accept_client( params, client_address, s_client_address, 64 ) ) {
 		close( client_fd );
+		debug("Closed client socket fd %d", client_fd);
 		return;
 	}
 
@@ -512,6 +513,7 @@ void accept_nbd_client(
 	if (slot < 0) {
 		warn("too many clients to accept connection");
 		close(client_fd);
+		debug("Closed client socket fd %d", client_fd);
 		return;
 	}
 	
@@ -528,6 +530,7 @@ void accept_nbd_client(
 		debug( "Thread creation problem." );
 		client_destroy( client_params );
 		close(client_fd);
+		debug("Closed client socket fd %d", client_fd);
 		return;
 	}
 	
@@ -655,7 +658,7 @@ int server_accept( struct server * params )
 
 	if ( FD_ISSET( params->server_fd, &fds ) ){
 		client_fd = accept( params->server_fd, &client_address.generic, &socklen );
-		debug("Accepted nbd client socket");
+		debug("Accepted nbd client socket fd %d", client_fd);
 		accept_nbd_client(params, client_fd, &client_address);
 	}