From patchwork Mon Jul 30 15:59:29 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Sage Weil X-Patchwork-Id: 1255161 Return-Path: X-Original-To: patchwork-ceph-devel@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id D6BFCDFE76 for ; Mon, 30 Jul 2012 15:59:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754144Ab2G3P7p (ORCPT ); Mon, 30 Jul 2012 11:59:45 -0400 Received: from cobra.newdream.net ([66.33.216.30]:45771 "EHLO cobra.newdream.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752936Ab2G3P7n (ORCPT ); Mon, 30 Jul 2012 11:59:43 -0400 Received: from nine.aon.corp.newdream.net (unknown [38.122.20.226]) by cobra.newdream.net (Postfix) with ESMTPA id 1494E8005F; Mon, 30 Jul 2012 08:59:43 -0700 (PDT) From: Sage Weil To: ceph-devel@vger.kernel.org Cc: Sage Weil Subject: [PATCH 6/8] libceph: avoid dropping con mutex before fault Date: Mon, 30 Jul 2012 08:59:29 -0700 Message-Id: <1343663971-3221-7-git-send-email-sage@inktank.com> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1343663971-3221-1-git-send-email-sage@inktank.com> References: <1343663971-3221-1-git-send-email-sage@inktank.com> Sender: ceph-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org The ceph_fault() function takes the con mutex, so we should avoid dropping it before calling it. This fixes a potential race with another thread calling ceph_con_close(), or _open(), or similar (we don't reverify con->state after retaking the lock). Add annotation so that lockdep realizes we will drop the mutex before returning. Signed-off-by: Sage Weil Reviewed-by: Alex Elder --- net/ceph/messenger.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c index feb5a2a..c3b628c 100644 --- a/net/ceph/messenger.c +++ b/net/ceph/messenger.c @@ -2336,7 +2336,6 @@ done_unlocked: return; fault: - mutex_unlock(&con->mutex); ceph_fault(con); /* error/fault path */ goto done_unlocked; } @@ -2347,9 +2346,8 @@ fault: * exponential backoff */ static void ceph_fault(struct ceph_connection *con) + __releases(con->mutex) { - mutex_lock(&con->mutex); - pr_err("%s%lld %s %s\n", ENTITY_NAME(con->peer_name), ceph_pr_addr(&con->peer_addr.in_addr), con->error_msg); dout("fault %p state %lu to peer %s\n",