From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-Id: <20120518212651.944059391@linuxfoundation.org> Date: Fri, 18 May 2012 14:27:19 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Ben Marzinski , Mike Snitzer , Alasdair G Kergon Subject: [ 30/47] dm mpath: check if scsi_dh module already loaded before trying to load In-Reply-To: <20120518212701.GA5023@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: 3.3-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: Greg Kroah-Hartman --- drivers/md/dm-mpath.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -698,8 +698,8 @@ static int parse_hw_handler(struct dm_ar 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;