From owner-svn-src-head@freebsd.org Tue Mar 31 02:26:06 2020 Return-Path: Delivered-To: svn-src-head@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id 2883227278B; Tue, 31 Mar 2020 02:26:06 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 48rtVL4nghz3xls; Tue, 31 Mar 2020 02:26:02 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id 561FBDB0; Tue, 31 Mar 2020 02:25:54 +0000 (UTC) (envelope-from markj@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id 02V2PstZ002634; Tue, 31 Mar 2020 02:25:54 GMT (envelope-from markj@FreeBSD.org) Received: (from markj@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id 02V2PsAC002633; Tue, 31 Mar 2020 02:25:54 GMT (envelope-from markj@FreeBSD.org) Message-Id: <202003310225.02V2PsAC002633@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: markj set sender to markj@FreeBSD.org using -f From: Mark Johnston Date: Tue, 31 Mar 2020 02:25:54 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r359477 - head/sys/netinet6 X-SVN-Group: head X-SVN-Commit-Author: markj X-SVN-Commit-Paths: head/sys/netinet6 X-SVN-Commit-Revision: 359477 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 31 Mar 2020 02:26:06 -0000 Author: markj Date: Tue Mar 31 02:25:53 2020 New Revision: 359477 URL: https://svnweb.freebsd.org/changeset/base/359477 Log: Use a dedicated taskqueue thread for in6m_release_task(). Interfaces may be detached from a taskqueue_thread task, for example by prison_complete(), so after r359438, when draining the queue we may end up deadlocking. Reported by: Jenkins via lwhsu MFC with: r359438 Modified: head/sys/netinet6/in6_mcast.c Modified: head/sys/netinet6/in6_mcast.c ============================================================================== --- head/sys/netinet6/in6_mcast.c Tue Mar 31 01:18:00 2020 (r359476) +++ head/sys/netinet6/in6_mcast.c Tue Mar 31 02:25:53 2020 (r359477) @@ -510,14 +510,19 @@ in6m_release(struct in6_multi *inm) } } -static struct task free_task; +/* + * Interface detach can happen in a taskqueue thread context, so we must use a + * dedicated thread to avoid deadlocks when draining in6m_release tasks. + */ +TASKQUEUE_DEFINE_THREAD(in6m_free); +static struct task in6m_free_task; static struct in6_multi_head in6m_free_list = SLIST_HEAD_INITIALIZER(); static void in6m_release_task(void *arg __unused, int pending __unused); static void in6m_init(void) { - TASK_INIT(&free_task, 0, in6m_release_task, NULL); + TASK_INIT(&in6m_free_task, 0, in6m_release_task, NULL); } SYSINIT(in6m_init, SI_SUB_TASKQ, SI_ORDER_ANY, in6m_init, NULL); @@ -529,13 +534,13 @@ in6m_release_list_deferred(struct in6_multi_head *inmh mtx_lock(&in6_multi_free_mtx); SLIST_CONCAT(&in6m_free_list, inmh, in6_multi, in6m_nrele); mtx_unlock(&in6_multi_free_mtx); - taskqueue_enqueue(taskqueue_thread, &free_task); + taskqueue_enqueue(taskqueue_in6m_free, &in6m_free_task); } void in6m_release_wait(void) { - taskqueue_drain_all(taskqueue_thread); + taskqueue_drain_all(taskqueue_in6m_free); } void