From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030421Ab3HBKLT (ORCPT ); Fri, 2 Aug 2013 06:11:19 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:37381 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030386Ab3HBKLJ (ORCPT ); Fri, 2 Aug 2013 06:11:09 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Alasdair G Kergon Subject: [ 64/99] dm ioctl: set noio flag to avoid __vmalloc deadlock Date: Fri, 2 Aug 2013 18:08:17 +0800 Message-Id: <20130802100234.946549211@linuxfoundation.org> X-Mailer: git-send-email 1.8.3.4.841.g1a3f60e In-Reply-To: <20130802100225.478715166@linuxfoundation.org> References: <20130802100225.478715166@linuxfoundation.org> User-Agent: quilt/0.60-5.1.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.10-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka commit 1c0e883e86ece31880fac2f84b260545d66a39e0 upstream. Set noio flag while calling __vmalloc() because it doesn't fully respect gfp flags to avoid a possible deadlock (see commit 502624bdad3dba45dfaacaf36b7d83e39e74b2d2). This should be backported to stable kernels 3.8 and newer. The kernel 3.8 doesn't have memalloc_noio_save(), so we should set and restore process flag PF_MEMALLOC instead. Signed-off-by: Mikulas Patocka Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-ioctl.c | 3 +++ 1 file changed, 3 insertions(+) --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1644,7 +1644,10 @@ static int copy_params(struct dm_ioctl _ } if (!dmi) { + unsigned noio_flag; + noio_flag = memalloc_noio_save(); dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH, PAGE_KERNEL); + memalloc_noio_restore(noio_flag); if (dmi) *param_flags |= DM_PARAMS_VMALLOC; }