From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:41788 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725878AbeHIJ1J (ORCPT ); Thu, 9 Aug 2018 05:27:09 -0400 Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id E49A0AE70 for ; Thu, 9 Aug 2018 07:03:41 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH] btrfs: qgroup: Dirty all qgroups before rescan Date: Thu, 9 Aug 2018 15:03:34 +0800 Message-Id: <20180809070334.6815-1-wqu@suse.com> Sender: linux-btrfs-owner@vger.kernel.org List-ID: [BUG] In the following case, rescan won't zero out the number of qgroup 1/0: ------ $ mkfs.btrfs -fq $DEV $ mount $DEV /mnt $ btrfs quota enable /mnt $ btrfs qgroup create 1/0 /mnt $ btrfs sub create /mnt/sub $ btrfs qgroup assign 0/257 1/0 /mnt $ dd if=/dev/urandom of=/mnt/sub/file bs=1k count=1000 $ btrfs sub snap /mnt/sub /mnt/snap $ btrfs quota rescan -w /mnt $ btrfs qgroup show -pcre /mnt qgroupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16.00KiB 16.00KiB none none --- --- 0/257 1016.00KiB 16.00KiB none none 1/0 --- 0/258 1016.00KiB 16.00KiB none none --- --- 1/0 1016.00KiB 16.00KiB none none --- 0/257 so far so good, but: $ btrfs qgroup remove 0/257 1/0 /mnt WARNING: quotas may be inconsistent, rescan needed $ btrfs quota rescan -w /mnt $ btrfs qgroup show -pcre /mnt qgoupid rfer excl max_rfer max_excl parent child -------- ---- ---- -------- -------- ------ ----- 0/5 16.00KiB 16.00KiB none none --- --- 0/257 1016.00KiB 16.00KiB none none --- --- 0/258 1016.00KiB 16.00KiB none none --- --- 1/0 1016.00KiB 16.00KiB none none --- --- ^^^^^^^^^^ ^^^^^^^^ not cleared ------ [CAUSE] Before rescan we call qgroup_rescan_zero_tracking() to zero out all qgroups' accounting numbers. However we don't mark all these qgroups dirty, but rely on rescan to mark qgroup dirty. If we have high level qgroup but without any child (orphan group), it won't be marked dirty during rescan, since we can reach that qgroup. This will cause QGROUP_INFO item of orphan qgroups never updated in quota tree, thus its number will stay the same in "btrfs qgroup show" output. [FIX] Just mark all qgroup dirty in qgroup_rescan_zero_tracking(), so even we have orphan qgroups their QGROUP_INFO item will still get updated during rescan. Reported-by: Misono Tomohiro Signed-off-by: Qu Wenruo --- fs/btrfs/qgroup.c | 1 + 1 file changed, 1 insertion(+) diff --git a/fs/btrfs/qgroup.c b/fs/btrfs/qgroup.c index 48c1c3e7baf3..5a5372b33d96 100644 --- a/fs/btrfs/qgroup.c +++ b/fs/btrfs/qgroup.c @@ -2864,6 +2864,7 @@ qgroup_rescan_zero_tracking(struct btrfs_fs_info *fs_info) qgroup->rfer_cmpr = 0; qgroup->excl = 0; qgroup->excl_cmpr = 0; + qgroup_dirty(fs_info, qgroup); } spin_unlock(&fs_info->qgroup_lock); } -- 2.18.0