Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752957AbbHRKlW (ORCPT ); Tue, 18 Aug 2015 06:41:22 -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 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-Type: text/plain; charset=us-ascii 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-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1235 Lines: 41 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); -- 2.5.0 -- Michal Hocko SUSE Labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/