From patchwork Tue Aug 18 10:41:16 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michal Hocko X-Patchwork-Id: 7030491 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.136]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 5E213C05AC for ; Tue, 18 Aug 2015 10:41:38 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 81735206D6 for ; Tue, 18 Aug 2015 10:41:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A37C9206B8 for ; Tue, 18 Aug 2015 10:41:36 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752942AbbHRKlV (ORCPT ); Tue, 18 Aug 2015 06:41:21 -0400 Received: from mail-wi0-f175.google.com ([209.85.212.175]:34736 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751898AbbHRKlT (ORCPT ); Tue, 18 Aug 2015 06:41:19 -0400 Received: by wicne3 with SMTP id ne3so96855785wic.1; Tue, 18 Aug 2015 03:41:17 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent; bh=vTmadAb0c4sv+mOUHCUhScRyJ7PVRWqyEulxZO8Rmnk=; b=FrkWyFAKnaf2pXzFlK68PTXVMBcRt/ScwvBEiyUZlpTkgHAfb2UiSfHxYRHQ69SmWf l+BjTOvAgcTZg+6S+P9w9wFLO66fzkPflKvuWNwqrrgS5SJOYGPbN0u2sNWi3aGtmcQ6 59D8tX97Fr8dkbQUXT57Ol86LjmJEK5Qyz3LRVD+h2XRTv3NEW3Kk6bFHz3HDbzbuyhm el0wvPV/4dKBsKyXvftmBiBbbjSzOtXBcu3XVIV+4EGBYIKceub88yE2AnXuJYxOSe+K PgMeyDxvO4H7433+rrrfxDbQwoQ65rVzm8EqHYcUYwiA1RsXn98mJxKaGz2com7me5xG sF1A== X-Received: by 10.194.109.97 with SMTP id hr1mr12248289wjb.38.1439894477524; Tue, 18 Aug 2015 03:41:17 -0700 (PDT) Received: from localhost (bband-dyn181.95-103-48.t-com.sk. [95.103.48.181]) by smtp.gmail.com with ESMTPSA id h6sm20798312wiy.3.2015.08.18.03.41.16 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 18 Aug 2015 03:41:17 -0700 (PDT) Date: Tue, 18 Aug 2015 12:41:16 +0200 From: Michal Hocko To: LKML Cc: linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Andrew Morton , Johannes Weiner , Tetsuo Handa , Dave Chinner , Theodore Ts'o , linux-btrfs@vger.kernel.org, linux-ext4@vger.kernel.org, Jan Kara Subject: [RFC -v2 8/8] btrfs: use __GFP_NOFAIL in alloc_btrfs_bio Message-ID: <20150818104116.GG5033@dhcp22.suse.cz> References: <1438768284-30927-1-git-send-email-mhocko@kernel.org> <1438768284-30927-9-git-send-email-mhocko@kernel.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1438768284-30927-9-git-send-email-mhocko@kernel.org> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.3 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Michal Hocko alloc_btrfs_bio is relying on GFP_NOFS to allocate a bio but since "mm: page_alloc: do not lock up GFP_NOFS allocations upon OOM" this is allowed to fail which can lead to [ 37.928625] kernel BUG at fs/btrfs/extent_io.c:4045 This is clearly undesirable and the nofail behavior should be explicit if the allocation failure cannot be tolerated. Signed-off-by: Michal Hocko --- fs/btrfs/volumes.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 53af23f2c087..42b9949dd71d 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4914,9 +4914,7 @@ static struct btrfs_bio *alloc_btrfs_bio(int total_stripes, int real_stripes) * and the stripes */ sizeof(u64) * (total_stripes), - GFP_NOFS); - if (!bbio) - return NULL; + GFP_NOFS|__GFP_NOFAIL); atomic_set(&bbio->error, 0); atomic_set(&bbio->refs, 1);