From patchwork Mon Dec 1 17:05:45 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Filipe Manana X-Patchwork-Id: 5414381 Return-Path: X-Original-To: patchwork-linux-btrfs@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 937029F30B for ; Mon, 1 Dec 2014 17:06:21 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7A2E5201F2 for ; Mon, 1 Dec 2014 17:06:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 970C2200F4 for ; Mon, 1 Dec 2014 17:06:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753359AbaLARGQ (ORCPT ); Mon, 1 Dec 2014 12:06:16 -0500 Received: from victor.provo.novell.com ([137.65.250.26]:45811 "EHLO prv3-mh.provo.novell.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752900AbaLARGP (ORCPT ); Mon, 1 Dec 2014 12:06:15 -0500 Received: from debian3.lan (prv-ext-foundry1int.gns.novell.com [137.65.251.240]) by prv3-mh.provo.novell.com with ESMTP (NOT encrypted); Mon, 01 Dec 2014 10:06:03 -0700 From: Filipe Manana To: linux-btrfs@vger.kernel.org Cc: Filipe Manana Subject: [PATCH] Btrfs: fix extent map leak on chunk allocation failure Date: Mon, 1 Dec 2014 17:05:45 +0000 Message-Id: <1417453545-31555-1-git-send-email-fdmanana@suse.com> X-Mailer: git-send-email 2.1.3 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, T_RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable 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 On error, after adding the extent map to the tree and to the pending chunks list, we would leave decrementing the extent map's refcount by 2 instead of 3 (our allocation + tree reference + list reference). Detected by 'rmmod btrfs': [20770.105881] kmem_cache_destroy btrfs_extent_map: Slab cache still has objects [20770.106127] CPU: 2 PID: 11093 Comm: rmmod Tainted: G W L 3.17.0-rc5-btrfs-next-1+ #1 [20770.106128] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [20770.106130] 0000000000000000 ffff8800ba867eb8 ffffffff813e7a13 ffff8800a2e11040 [20770.106132] ffff8800ba867ed0 ffffffff81105d0c 0000000000000000 ffff8800ba867ee0 [20770.106134] ffffffffa035d65e ffff8800ba867ef0 ffffffffa03b0654 ffff8800ba867f78 [20770.106136] Call Trace: [20770.106142] [] dump_stack+0x45/0x56 [20770.106145] [] kmem_cache_destroy+0x4b/0x90 [20770.106164] [] extent_map_exit+0x1a/0x1c [btrfs] [20770.106176] [] exit_btrfs_fs+0x27/0x9d3 [btrfs] [20770.106179] [] SyS_delete_module+0x153/0x1c4 [20770.106182] [] ? trace_hardirqs_on_thunk+0x3a/0x3c [20770.106184] [] system_call_fastpath+0x16/0x1b Signed-off-by: Filipe Manana --- fs/btrfs/volumes.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 66a5a1e..e936fe3 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -4496,6 +4496,8 @@ error_del_extent: free_extent_map(em); /* One for the tree reference */ free_extent_map(em); + /* One for the pending_chunks list reference */ + free_extent_map(em); error: kfree(devices_info); return ret;