DATA RACE in the Job's Warnings

[hawkingrei]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

 WARNING: DATA RACE
Read at 0x00c00ea158a0 by goroutine 193529:
  github.com/pingcap/tidb/parser/model.(*Job).String()
      parser/model/ddl.go:672 +0x4b1
  github.com/pingcap/tidb/ddl.(*worker).addPhysicalTableIndex()
      ddl/index.go:1719 +0x356
  github.com/pingcap/tidb/ddl.(*worker).addTableIndex()
      ddl/index.go:1733 +0x411
  github.com/pingcap/tidb/ddl.runReorgJobAndHandleErr.func1()
      ddl/index.go:928 +0x131
  github.com/pingcap/tidb/ddl.(*worker).runReorgJob.func1()
      ddl/reorg.go:211 +0x92
Previous write at 0x00c00ea158a0 by goroutine 193422:
  github.com/pingcap/tidb/parser/model.(*Job).SetWarnings()
      parser/model/ddl.go:598 +0x231
  github.com/pingcap/tidb/ddl.(*worker).mergeWarningsIntoJob()
      ddl/reorg.go:283 +0x137
  github.com/pingcap/tidb/ddl.(*worker).runReorgJob()
      ddl/reorg.go:264 +0xd10
  github.com/pingcap/tidb/ddl.runReorgJobAndHandleErr()
      ddl/index.go:923 +0x687
  github.com/pingcap/tidb/ddl.doReorgWorkForCreateIndex()
      ddl/index.go:856 +0xc48
  github.com/pingcap/tidb/ddl.(*worker).onCreateIndex()
      ddl/index.go:670 +0x11ad
  github.com/pingcap/tidb/ddl.(*worker).runDDLJob()
      ddl/ddl_worker.go:1011 +0x7f5
  github.com/pingcap/tidb/ddl.(*worker).HandleDDLJobTable()
      ddl/ddl_worker.go:763 +0x67c
  github.com/pingcap/tidb/ddl.(*ddl).delivery2worker.func1()
      ddl/job_table.go:271 +0xb45
  github.com/pingcap/tidb/util.(*WaitGroupWrapper).Run.func1()
      util/wait_group_wrapper.go:154 +0x73
Goroutine 193529 (running) created at:
  github.com/pingcap/tidb/ddl.(*worker).runReorgJob()
      ddl/reorg.go:209 +0x579
  github.com/pingcap/tidb/ddl.runReorgJobAndHandleErr()
      ddl/index.go:923 +0x687
  github.com/pingcap/tidb/ddl.doReorgWorkForCreateIndex()
      ddl/index.go:856 +0xc48
  github.com/pingcap/tidb/ddl.(*worker).onCreateIndex()
      ddl/index.go:670 +0x11ad
  github.com/pingcap/tidb/ddl.(*worker).runDDLJob()
      ddl/ddl_worker.go:1011 +0x7f5
  github.com/pingcap/tidb/ddl.(*worker).HandleDDLJobTable()
      ddl/ddl_worker.go:763 +0x67c
  github.com/pingcap/tidb/ddl.(*ddl).delivery2worker.func1()
      ddl/job_table.go:271 +0xb45
  github.com/pingcap/tidb/util.(*WaitGroupWrapper).Run.func1()
      util/wait_group_wrapper.go:154 +0x73
Goroutine 193422 (finished) created at:
  github.com/pingcap/tidb/util.(*WaitGroupWrapper).Run()
      util/wait_group_wrapper.go:152 +0xe4
  github.com/pingcap/tidb/ddl.(*ddl).delivery2worker()
      ddl/job_table.go:230 +0x1b7
  github.com/pingcap/tidb/ddl.(*ddl).loadDDLJobAndRun()
      ddl/job_table.go:223 +0x57c
  github.com/pingcap/tidb/ddl.(*ddl).startDispatchLoop()
      ddl/job_table.go:196 +0xad1
  github.com/pingcap/tidb/ddl.(*ddl).startDispatchLoop-fm()
      <autogenerated>:1 +0x39
  github.com/pingcap/tidb/util.(*WaitGroupWrapper).Run.func1()
      util/wait_group_wrapper.go:154 +0x73
================== 

2. What did you expect to see? (Required)

3. What did you see instead (Required)

4. What is your TiDB version? (Required)

[hawkingrei]

Here is the log

https://prow.pingcap.net/view/gs/pingcapprow/logs/tidb_race/1616303872333058048