From patchwork Mon Feb 6 14:07:18 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Hocko X-Patchwork-Id: 724510 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3vH8T10WkBz9s2Q for ; Tue, 7 Feb 2017 01:08:21 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753617AbdBFOHw (ORCPT ); Mon, 6 Feb 2017 09:07:52 -0500 Received: from mail-wm0-f66.google.com ([74.125.82.66]:36008 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753780AbdBFOHh (ORCPT ); Mon, 6 Feb 2017 09:07:37 -0500 Received: by mail-wm0-f66.google.com with SMTP id r18so22175845wmd.3; Mon, 06 Feb 2017 06:07:35 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=HDDlwu0SkYfMELY0N2+CAjD1836h466f1Ls1SYKg1MA=; b=QjmOxE0ivhKShPLOf88bpF5Bw8AigbE8wnExc+1CMkhPtwVNeaD7I+dtS6euBhfcwS zysF8/hlMpTOOkppQDri1NdSUiZBUUoX3sIko1PpETsnuJRiJXKv/LKIKgPABd+ubnP8 2Ny+wm+VVl/o5Kb/XxDOetxR1KmoEcXETSaWibYBqLxxCxapC9aLjtrkA630TQm3a4bD Ek4ST9TgF7cdUYkJkkw4TpTxW9lO+U7jookPTiC92y6qtT/+uDRdfli7MyrGaHKgP9qh SaOncdYnQsrYgMtxLJXTzCVzeOe1Tnv0b2H/BAWgLz20D3fK/uE0rXx1vpTTbPabsQ7W sLCw== X-Gm-Message-State: AMke39mGYMjE6e7iwpxZBh8QqSnRCzRNA76KwNKfFo0u7iyWnAvOkk4S7RxUHUOHewZf6w== X-Received: by 10.28.51.205 with SMTP id z196mr8335483wmz.22.1486390054700; Mon, 06 Feb 2017 06:07:34 -0800 (PST) Received: from tiehlicka.suse.cz (prg-ext-pat.suse.com. [213.151.95.130]) by smtp.gmail.com with ESMTPSA id 191sm13112265wmo.21.2017.02.06.06.07.33 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 06 Feb 2017 06:07:34 -0800 (PST) From: Michal Hocko To: Andrew Morton , Cc: , Dave Chinner , djwong@kernel.org, "Theodore Ts'o" , Chris Mason , David Sterba , Jan Kara , ceph-devel@vger.kernel.org, cluster-devel@redhat.com, linux-nfs@vger.kernel.org, logfs@logfs.org, linux-xfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-btrfs@vger.kernel.org, linux-mtd@lists.infradead.org, reiserfs-devel@vger.kernel.org, linux-ntfs-dev@lists.sourceforge.net, linux-f2fs-devel@lists.sourceforge.net, linux-afs@lists.infradead.org, LKML , Michal Hocko Subject: [PATCH 6/6] jbd2: make the whole kjournald2 kthread NOFS safe Date: Mon, 6 Feb 2017 15:07:18 +0100 Message-Id: <20170206140718.16222-7-mhocko@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20170206140718.16222-1-mhocko@kernel.org> References: <20170206140718.16222-1-mhocko@kernel.org> Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org From: Michal Hocko kjournald2 is central to the transaction commit processing. As such any potential allocation from this kernel thread has to be GFP_NOFS. Make sure to mark the whole kernel thread GFP_NOFS by the memalloc_nofs_save. Suggested-by: Jan Kara Reviewed-by: Jan Kara Signed-off-by: Michal Hocko --- fs/jbd2/journal.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 704139625fbe..662531a70ce1 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -206,6 +206,13 @@ static int kjournald2(void *arg) wake_up(&journal->j_wait_done_commit); /* + * Make sure that no allocations from this kernel thread will ever recurse + * to the fs layer because we are responsible for the transaction commit + * and any fs involvement might get stuck waiting for the trasn. commit. + */ + memalloc_nofs_save(); + + /* * And now, wait forever for commit wakeup events. */ write_lock(&journal->j_state_lock);