From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:60776 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1725198AbeHJEsN (ORCPT ); Fri, 10 Aug 2018 00:48:13 -0400 Received: from relay1.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 42DD8AED4 for ; Fri, 10 Aug 2018 02:20:30 +0000 (UTC) From: Qu Wenruo To: linux-btrfs@vger.kernel.org Subject: [PATCH v3] btrfs: qgroup: Dirty all qgroups before rescan Date: Fri, 10 Aug 2018 10:20:26 +0800 Message-Id: <20180810022026.27989-1-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 qgroups dirty, but rely on rescan to mark qgroups dirty. If we have any high level qgroup without children, it won't be marked dirty during rescan, since we can not reach that qgroup. This will cause QGROUP_INFO items of childless qgroups never get updated in quota tree, thus their numbers will stay the same in "btrfs qgroup show" output. [FIX] Just mark all qgroups dirty in qgroup_rescan_zero_tracking(), so even we have childless qgroups, their QGROUP_INFO items will still get updated during rescan. Reported-by: Misono Tomohiro Signed-off-by: Qu Wenruo Reviewed-by: Misono Tomohiro Tested-by: Misono Tomohiro --- changelog: v2: Fix some grammar errors in commit message. v3: Fix the adjective used for qgroups without children, from "orphan" to "childless". Update tags. --- 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