From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88B54C7112A for ; Sun, 14 Oct 2018 15:43:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5B12D20876 for ; Sun, 14 Oct 2018 15:43:22 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5B12D20876 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729207AbeJNXYn (ORCPT ); Sun, 14 Oct 2018 19:24:43 -0400 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:37000 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728020AbeJNXYm (ORCPT ); Sun, 14 Oct 2018 19:24:42 -0400 Received: from [2a02:8011:400e:2:cbab:f00:c93f:614] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.84_2) (envelope-from ) id 1gBiME-0004cj-S1; Sun, 14 Oct 2018 16:31:07 +0100 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gBiLP-0000D4-2Y; Sun, 14 Oct 2018 16:30:15 +0100 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Liu Bo" , "David Sterba" Date: Sun, 14 Oct 2018 16:25:40 +0100 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) Subject: [PATCH 3.16 056/366] Btrfs: fix unexpected cow in run_delalloc_nocow In-Reply-To: X-SA-Exim-Connect-IP: 2a02:8011:400e:2:cbab:f00:c93f:614 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.60-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Liu Bo commit 5811375325420052fcadd944792a416a43072b7f upstream. Fstests generic/475 provides a way to fail metadata reads while checking if checksum exists for the inode inside run_delalloc_nocow(), and csum_exist_in_range() interprets error (-EIO) as inode having checksum and makes its caller enter the cow path. In case of free space inode, this ends up with a warning in cow_file_range(). The same problem applies to btrfs_cross_ref_exist() since it may also read metadata in between. With this, run_delalloc_nocow() bails out when errors occur at the two places. Fixes: 17d217fe970d ("Btrfs: fix nodatasum handling in balancing code") Signed-off-by: Liu Bo Signed-off-by: David Sterba [bwh: Backported to 3.16: adjust context] Signed-off-by: Ben Hutchings --- --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1145,6 +1145,8 @@ static noinline int csum_exist_in_range( list_del(&sums->list); kfree(sums); } + if (ret < 0) + return ret; return 1; } @@ -1294,10 +1296,23 @@ next_slot: goto out_check; if (btrfs_extent_readonly(root, disk_bytenr)) goto out_check; - if (btrfs_cross_ref_exist(trans, root, ino, - found_key.offset - - extent_offset, disk_bytenr)) + ret = btrfs_cross_ref_exist(trans, root, ino, + found_key.offset - + extent_offset, disk_bytenr); + if (ret) { + /* + * ret could be -EIO if the above fails to read + * metadata. + */ + if (ret < 0) { + if (cow_start != (u64)-1) + cur_offset = cow_start; + goto error; + } + + WARN_ON_ONCE(nolock); goto out_check; + } disk_bytenr += extent_offset; disk_bytenr += cur_offset - found_key.offset; num_bytes = min(end + 1, extent_end) - cur_offset; @@ -1315,8 +1330,22 @@ next_slot: * this ensure that csum for a given extent are * either valid or do not exist. */ - if (csum_exist_in_range(root, disk_bytenr, num_bytes)) + ret = csum_exist_in_range(root, disk_bytenr, + num_bytes); + if (ret) { + + /* + * ret could be -EIO if the above fails to read + * metadata. + */ + if (ret < 0) { + if (cow_start != (u64)-1) + cur_offset = cow_start; + goto error; + } + WARN_ON_ONCE(nolock); goto out_check; + } nocow = 1; } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { extent_end = found_key.offset +