On 2018/08/09 16:08, Qu Wenruo wrote: > [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 but without any child (orphan group), it > won't be marked dirty during rescan, since we can not reach that qgroup. > > This will cause QGROUP_INFO items of orphan 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 orphan qgroups their QGROUP_INFO items will still get updated during > rescan. > > Reported-by: Misono Tomohiro <misono.tomoh...@jp.fujitsu.com> > Signed-off-by: Qu Wenruo <w...@suse.com> > --- > changelog: > v2: > Fix some grammar errors in commit message. > --- > 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); > } > Yes, this and previous patch [PATCH] btrfs: qgroup: Don't populating excl numbers for snapshot src if it belongs to other qgroups resolves the problem I see.
So, this will reset all the qgroup items not rescanned in first transaction commit by btrfs_run_qgroups(), but I don't think it is a problem. Tested-by/Reviewed-by: Misono Tomohiro <misono.tomoh...@jp.fujitsu.com> Thanks, Misono -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
