From mboxrd@z Thu Jan 1 00:00:00 1970 From: sunwenjie Subject: [PATCH] vhostuser: fix deadlock when vhost unregister Date: Tue, 8 Jan 2019 19:45:09 +0800 Message-ID: <20190108114509.31489-1-findtheonlyway@gmail.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Cc: sunwenjie To: dev@dpdk.org Return-path: Received: from mail-pf1-f193.google.com (mail-pf1-f193.google.com [209.85.210.193]) by dpdk.org (Postfix) with ESMTP id 2245CDE0 for ; Tue, 8 Jan 2019 12:45:20 +0100 (CET) Received: by mail-pf1-f193.google.com with SMTP id z9so1829372pfi.2 for ; Tue, 08 Jan 2019 03:45:20 -0800 (PST) List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" When rte_vhost_driver_unregister delete the connection fd, fdset_try_del will always try and donot release the vhostuser.mutex if the fd is busy, but the fdset_event_dispatch will set the fd to busy and call vhost_user_msg_handler to get vhostuser.mutex, which will cause deadlock. To fix it: Unlock the vhost_user.mutex if fdset_try_del fail and relock it when retry. --- lib/librte_vhost/socket.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/lib/librte_vhost/socket.c b/lib/librte_vhost/socket.c index 9cf34ad17..a9effa115 100644 --- a/lib/librte_vhost/socket.c +++ b/lib/librte_vhost/socket.c @@ -961,13 +961,12 @@ rte_vhost_driver_unregister(const char *path) int count; struct vhost_user_connection *conn, *next; +again: pthread_mutex_lock(&vhost_user.mutex); for (i = 0; i < vhost_user.vsocket_cnt; i++) { struct vhost_user_socket *vsocket = vhost_user.vsockets[i]; - if (!strcmp(vsocket->path, path)) { -again: pthread_mutex_lock(&vsocket->conn_mutex); for (conn = TAILQ_FIRST(&vsocket->conn_list); conn != NULL; @@ -981,6 +980,7 @@ rte_vhost_driver_unregister(const char *path) */ if (fdset_try_del(&vhost_user.fdset, conn->connfd) == -1) { + pthread_mutex_unlock(&vhost_user.mutex); pthread_mutex_unlock( &vsocket->conn_mutex); goto again; -- 2.14.3 (Apple Git-98)