From patchwork Thu Mar 31 00:57:48 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Fasheh X-Patchwork-Id: 8706781 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 BD8CDC0553 for ; Thu, 31 Mar 2016 00:57:56 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id BB54C20374 for ; Thu, 31 Mar 2016 00:57:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9022720357 for ; Thu, 31 Mar 2016 00:57:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751070AbcCaA5v (ORCPT ); Wed, 30 Mar 2016 20:57:51 -0400 Received: from mx2.suse.de ([195.135.220.15]:51925 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750905AbcCaA5u (ORCPT ); Wed, 30 Mar 2016 20:57:50 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (charybdis-ext.suse.de [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id BB1B3ABB0; Thu, 31 Mar 2016 00:57:47 +0000 (UTC) Date: Wed, 30 Mar 2016 17:57:48 -0700 From: Mark Fasheh To: linux-btrfs@vger.kernel.org Cc: clm@fb.com, jbacik@fb.com Subject: [PATCH] btrfs: handle non-fatal errors in btrfs_qgroup_inherit() Message-ID: <20160331005748.GI15881@wotan.suse.de> Reply-To: Mark Fasheh MIME-Version: 1.0 Content-Disposition: inline Organization: SUSE Labs User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Spam-Status: No, score=-7.9 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 create_pending_snapshot() will go readonly on _any_ error return from btrfs_qgroup_inherit(). If qgroups are enabled, a user can crash their fs by just making a snapshot and asking it to inherit from an invalid qgroup. For example: $ btrfs sub snap -i 1/10 /btrfs/ /btrfs/foo Will cause a transaction abort. Fix this by only throwing errors in btrfs_qgroup_inherit() when we know going readonly is acceptable. The following xfstests test case reproduces this bug: seq=`basename $0` seqres=$RESULT_DIR/$seq echo "QA output created by $seq" here=`pwd` tmp=/tmp/$$ status=1 # failure is the default! trap "_cleanup; exit \$status" 0 1 2 3 15 _cleanup() { cd / rm -f $tmp.* } # get standard environment, filters and checks . ./common/rc . ./common/filter # remove previous $seqres.full before test rm -f $seqres.full # real QA test starts here _supported_fs btrfs _supported_os Linux _require_scratch rm -f $seqres.full _scratch_mkfs _scratch_mount _run_btrfs_util_prog quota enable $SCRATCH_MNT # The qgroup '1/10' does not exist and should be silently ignored _run_btrfs_util_prog subvolume snapshot -i 1/10 $SCRATCH_MNT $SCRATCH_MNT/snap1 _scratch_unmount echo "Silence is golden" status=0 exit Signed-off-by: Mark Fasheh Reviewed-by: Qu Wenruo --- fs/btrfs/qgroup.c | 54 ++++++++++++++++++++++++++++++++---------------------- 1 file changed, 32 insertions(+), 22 deletions(-) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 994dab0..9e11955 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -1851,8 +1851,10 @@ out: } /* - * copy the acounting information between qgroups. This is necessary when a - * snapshot or a subvolume is created + * Copy the acounting information between qgroups. This is necessary + * when a snapshot or a subvolume is created. Throwing an error will + * cause a transaction abort so we take extra care here to only error + * when a readonly fs is a reasonable outcome. */ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 srcid, u64 objectid, @@ -1882,15 +1884,15 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, 2 * inherit->num_excl_copies; for (i = 0; i < nums; ++i) { srcgroup = find_qgroup_rb(fs_info, *i_qgroups); - if (!srcgroup) { - ret = -EINVAL; - goto out; - } - if ((srcgroup->qgroupid >> 48) <= (objectid >> 48)) { - ret = -EINVAL; - goto out; - } + /* + * Zero out invalid groups so we can ignore + * them later. + */ + if (!srcgroup || + ((srcgroup->qgroupid >> 48) <= (objectid >> 48))) + *i_qgroups = 0ULL; + ++i_qgroups; } } @@ -1925,17 +1927,19 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, */ if (inherit) { i_qgroups = (u64 *)(inherit + 1); - for (i = 0; i < inherit->num_qgroups; ++i) { + for (i = 0; i < inherit->num_qgroups; ++i, ++i_qgroups) { + if (*i_qgroups == 0) + continue; ret = add_qgroup_relation_item(trans, quota_root, objectid, *i_qgroups); - if (ret) + if (ret && ret != -EEXIST) goto out; ret = add_qgroup_relation_item(trans, quota_root, *i_qgroups, objectid); - if (ret) + if (ret && ret != -EEXIST) goto out; - ++i_qgroups; } + ret = 0; } @@ -1996,17 +2000,22 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, i_qgroups = (u64 *)(inherit + 1); for (i = 0; i < inherit->num_qgroups; ++i) { - ret = add_relation_rb(quota_root->fs_info, objectid, - *i_qgroups); - if (ret) - goto unlock; + if (*i_qgroups) { + ret = add_relation_rb(quota_root->fs_info, objectid, + *i_qgroups); + if (ret) + goto unlock; + } ++i_qgroups; } - for (i = 0; i < inherit->num_ref_copies; ++i) { + for (i = 0; i < inherit->num_ref_copies; ++i, i_qgroups += 2) { struct btrfs_qgroup *src; struct btrfs_qgroup *dst; + if (!i_qgroups[0] || !i_qgroups[1]) + continue; + src = find_qgroup_rb(fs_info, i_qgroups[0]); dst = find_qgroup_rb(fs_info, i_qgroups[1]); @@ -2017,12 +2026,14 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, dst->rfer = src->rfer - level_size; dst->rfer_cmpr = src->rfer_cmpr - level_size; - i_qgroups += 2; } - for (i = 0; i < inherit->num_excl_copies; ++i) { + for (i = 0; i < inherit->num_excl_copies; ++i, i_qgroups += 2) { struct btrfs_qgroup *src; struct btrfs_qgroup *dst; + if (!i_qgroups[0] || !i_qgroups[1]) + continue; + src = find_qgroup_rb(fs_info, i_qgroups[0]); dst = find_qgroup_rb(fs_info, i_qgroups[1]); @@ -2033,7 +2044,6 @@ int btrfs_qgroup_inherit(struct btrfs_trans_handle *trans, dst->excl = src->excl + level_size; dst->excl_cmpr = src->excl_cmpr + level_size; - i_qgroups += 2; } unlock: