From patchwork Tue Jul 16 22:54:04 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kamal Mostafa X-Patchwork-Id: 259546 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from huckleberry.canonical.com (huckleberry.canonical.com [91.189.94.19]) by ozlabs.org (Postfix) with ESMTP id A541C2C0102 for ; Wed, 17 Jul 2013 09:03:09 +1000 (EST) Received: from localhost ([127.0.0.1] helo=huckleberry.canonical.com) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UzEGs-0001qZ-Pq; Tue, 16 Jul 2013 23:03:02 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by huckleberry.canonical.com with esmtp (Exim 4.76) (envelope-from ) id 1UzE8E-0000Pg-Ef for kernel-team@lists.ubuntu.com; Tue, 16 Jul 2013 22:54:06 +0000 Received: from c-67-160-231-162.hsd1.ca.comcast.net ([67.160.231.162] helo=fourier) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1UzE8E-00046I-8K; Tue, 16 Jul 2013 22:54:06 +0000 Received: from kamal by fourier with local (Exim 4.80) (envelope-from ) id 1UzE8C-0007OC-CL; Tue, 16 Jul 2013 15:54:04 -0700 From: Kamal Mostafa To: Mikulas Patocka Subject: [ 3.8.y.z extended stable ] Patch "dm ioctl: set noio flag to avoid __vmalloc deadlock" has been added to staging queue Date: Tue, 16 Jul 2013 15:54:04 -0700 Message-Id: <1374015244-28371-1-git-send-email-kamal@canonical.com> X-Mailer: git-send-email 1.8.1.2 X-Extended-Stable: 3.8 Cc: Kamal Mostafa , kernel-team@lists.ubuntu.com, Alasdair G Kergon X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.14 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: kernel-team-bounces@lists.ubuntu.com Sender: kernel-team-bounces@lists.ubuntu.com This is a note to let you know that I have just added a patch titled dm ioctl: set noio flag to avoid __vmalloc deadlock to the linux-3.8.y-queue branch of the 3.8.y.z extended stable tree which can be found at: http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.8.y-queue This patch is scheduled to be released in version 3.8.13.5. If you, or anyone else, feels it should not be added to this tree, please reply to this email. For more information about the 3.8.y.z tree, see https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable Thanks. -Kamal ------ From ff1aaf9a90e1874ace1b722018aff5e1a61c00b0 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 10 Jul 2013 23:41:15 +0100 Subject: dm ioctl: set noio flag to avoid __vmalloc deadlock 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 [ kamal: backport to 3.8 (memalloc_noio_save is available in linux-3.8.y.z) ] Signed-off-by: Kamal Mostafa --- drivers/md/dm-ioctl.c | 3 +++ 1 file changed, 3 insertions(+) -- 1.8.1.2 diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index eee353d..4c260aa 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1585,7 +1585,10 @@ static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param, in dmi = kmalloc(tmp.data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); if (!dmi) { + unsigned noio_flag; + noio_flag = memalloc_noio_save(); dmi = __vmalloc(tmp.data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH, PAGE_KERNEL); + memalloc_noio_restore(noio_flag); *param_flags |= DM_PARAMS_VMALLOC; }