From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031058Ab2ERDEh (ORCPT ); Thu, 17 May 2012 23:04:37 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:40459 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762553Ab2ERCwf (ORCPT ); Thu, 17 May 2012 22:52:35 -0400 Message-Id: <20120518023258.316703628@decadent.org.uk> User-Agent: quilt/0.60-1 Date: Fri, 18 May 2012 03:33:23 +0100 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Mike Snitzer , Ben Marzinski , Alasdair G Kergon Subject: [ 29/53] dm mpath: check if scsi_dh module already loaded before trying to load In-Reply-To: <20120518023254.339945758@decadent.org.uk> X-SA-Exim-Connect-IP: 192.168.4.185 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.2.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mike Snitzer commit 510193a2d3d2e03ae53b95c0ae4f33cdff02cbf8 upstream. If the requested scsi_dh module is already loaded then skip request_module(). Multipath table loads can hang in an unnecessary __request_module. Reported-by: Ben Marzinski Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon Signed-off-by: Ben Hutchings --- drivers/md/dm-mpath.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 922a338..754f38f 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -718,8 +718,8 @@ static int parse_hw_handler(struct dm_arg_set *as, struct multipath *m) return 0; m->hw_handler_name = kstrdup(dm_shift_arg(as), GFP_KERNEL); - request_module("scsi_dh_%s", m->hw_handler_name); - if (scsi_dh_handler_exist(m->hw_handler_name) == 0) { + if (!try_then_request_module(scsi_dh_handler_exist(m->hw_handler_name), + "scsi_dh_%s", m->hw_handler_name)) { ti->error = "unknown hardware handler type"; ret = -EINVAL; goto fail; -- 1.7.10