DM: Inconsistency applies to tasks configured with both db and table rules in block-allow-list

[OliverS929]

What did you do?

Specified in config file:

block-allow-list:
  bw-rule-1:
    do-tables:
      - db-name: db1
        tbl_name: '*'
      - db-name: db2
        tbl_name: t1
     do-dbs:  [db1]

What did you expect to see?

Expect to see all tables in db1 and t1 in db2 are migrated.

What did you see instead?

tables in db1 are handled just fine, but t1 in db2 are ignored.

Versions of the cluster

DM version (run dmctl -V or dm-worker -V or dm-master -V):

8.5

Upstream MySQL/MariaDB server version:

8.0

Downstream TiDB cluster version (execute SELECT tidb_version(); in a MySQL client):

8.5

How did you deploy DM: tiup or manually?

tiup/manually

Other interesting information (system version, hardware config, etc):

>
>

current status of DM cluster (execute query-status <task-name> in dmctl)

Finished

[OliverS929]

This is likely due to the fact that DM uses ParseMySQLReplicationRules from tidb github.com/pingcap/tidb/pkg/util/table-filter, which utilizebothfilter in table and schema matching and requires both schemaRules and tableRules to be matched at the same time. In our case, migration rule of db2.t1 only exists in tableRules but not tableRules, and therefore would failed in both MatchTable and MatchSchema from bothfilter, implementations of which are:

func (f *bothFilter) MatchTable(schema string, table string) bool {
	return f.a.MatchTable(schema, table) && f.b.MatchTable(schema, table)
}

func (f *bothFilter) MatchSchema(schema string) bool {
	return f.a.MatchSchema(schema) && f.b.MatchSchema(schema)
}