From patchwork Thu Feb 1 00:09:13 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Liu Bo X-Patchwork-Id: 10194985 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4A4DD603B4 for ; Thu, 1 Feb 2018 01:12:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 29E842860F for ; Thu, 1 Feb 2018 01:12:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 1E6DB28874; Thu, 1 Feb 2018 01:12:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI, T_DKIM_INVALID, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 697E32860F for ; Thu, 1 Feb 2018 01:12:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755941AbeBABL7 (ORCPT ); Wed, 31 Jan 2018 20:11:59 -0500 Received: from aserp2130.oracle.com ([141.146.126.79]:52352 "EHLO aserp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755903AbeBABL6 (ORCPT ); Wed, 31 Jan 2018 20:11:58 -0500 Received: from pps.filterd (aserp2130.oracle.com [127.0.0.1]) by aserp2130.oracle.com (8.16.0.22/8.16.0.22) with SMTP id w1112I9W190438 for ; Thu, 1 Feb 2018 01:11:58 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : subject : date : message-id : in-reply-to : references; s=corp-2017-10-26; bh=0Vg6Cwl5/0OuAOpxou5j3rH41gCSDdAQbPx7RaqqPsQ=; b=YeVXxo98bnqQMRn1xrV09hT+7DvLUu4jLk/o44AJ1+R1JXfU85nyI0e4ibq+Ps5rGkRZ 2+nPjNVZX+oeke1fMnH8MigBmMprLjr0116VgJ+m8VWUZ47DO8tlR/vAwedtXHeyyoxC 2zah2ZZ6/BMApkEwTjR+wBAGY3gypBnvsTIjKbWmhJzxwZWuAqt4vUWXSYEBf4EcQIAo CWbKJZkF1TVXIpKrOU7Um6RlzxxLj9kLnBsQIaDAYG6xHhUXTzVVSnRaCQCXXc4GPgPN zR4JS7wytq6kodUDlcGt9R1KvIhtJ4pz4w6iRLZus67ekc/2IKPbyrXzJnOb1yni17P+ ug== Received: from userv0022.oracle.com (userv0022.oracle.com [156.151.31.74]) by aserp2130.oracle.com with ESMTP id 2fuqkfr7n6-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK) for ; Thu, 01 Feb 2018 01:11:57 +0000 Received: from userv0121.oracle.com (userv0121.oracle.com [156.151.31.72]) by userv0022.oracle.com (8.14.4/8.14.4) with ESMTP id w111Bv9J029299 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL) for ; Thu, 1 Feb 2018 01:11:57 GMT Received: from abhmp0002.oracle.com (abhmp0002.oracle.com [141.146.116.8]) by userv0121.oracle.com (8.14.4/8.13.8) with ESMTP id w111Buj5019862 for ; Thu, 1 Feb 2018 01:11:57 GMT Received: from dhcp-10-211-47-181.usdhcp.oraclecorp.com.com (/10.211.47.181) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Wed, 31 Jan 2018 17:11:56 -0800 From: Liu Bo To: linux-btrfs@vger.kernel.org Subject: [PATCH v2] Btrfs: fix unexpected cow in run_delalloc_nocow Date: Wed, 31 Jan 2018 17:09:13 -0700 Message-Id: <20180201000913.27378-1-bo.li.liu@oracle.com> X-Mailer: git-send-email 2.9.4 In-Reply-To: <20180125180256.10844-2-bo.li.liu@oracle.com> References: <20180125180256.10844-2-bo.li.liu@oracle.com> X-Proofpoint-Virus-Version: vendor=nai engine=5900 definitions=8791 signatures=668659 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 suspectscore=18 malwarescore=0 phishscore=0 bulkscore=0 spamscore=0 mlxscore=0 mlxlogscore=631 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1711220000 definitions=main-1802010012 Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 enters the cow path. In case of free space inode, this ends up with a warning in cow_file_range(). The same problem applies for 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. cc: v2.6.28+ Fixes: 17d217fe970d ("Btrfs: fix nodatasum handling in balancing code") Signed-off-by: Liu Bo --- v2: fix error handling after btrfs_cross_ref_exist(). fs/btrfs/inode.c | 37 ++++++++++++++++++++++++++++++++----- 1 file changed, 32 insertions(+), 5 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index e1a7f3c..8f2bd04 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1257,6 +1257,8 @@ static noinline int csum_exist_in_range(struct btrfs_fs_info *fs_info, list_del(&sums->list); kfree(sums); } + if (ret < 0) + return ret; return 1; } @@ -1386,10 +1388,23 @@ static noinline int run_delalloc_nocow(struct inode *inode, goto out_check; if (btrfs_extent_readonly(fs_info, disk_bytenr)) goto out_check; - if (btrfs_cross_ref_exist(root, ino, - found_key.offset - - extent_offset, disk_bytenr)) + ret = btrfs_cross_ref_exist(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; @@ -1407,10 +1422,22 @@ static noinline int run_delalloc_nocow(struct inode *inode, * this ensure that csum for a given extent are * either valid or do not exist. */ - if (csum_exist_in_range(fs_info, disk_bytenr, - num_bytes)) { + ret = csum_exist_in_range(fs_info, disk_bytenr, + num_bytes); + if (ret) { if (!nolock) btrfs_end_write_no_snapshotting(root); + + /* + * 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; } if (!btrfs_inc_nocow_writers(fs_info, disk_bytenr)) {