fix: race condition in lockMap

[andyzhangx]

What type of PR is this?

/kind bug

What this PR does / why we need it:

fix: race condition in lockMap

lm.Lock() is intended for locking lm.mutexMap, while original logic in LockEntry does not lock lm.mutexMap well, in lm.lockEntry(entry), it's still accessing lm.mutexMap outside of lm.Lock() ... lm.Unlock()

This PR removes addEntry func invoke, make lm.mutexMap access inside of lm.Lock() ... lm.Unlock(), and then lock ougside.

Which issue(s) this PR fixes:

Fixes #

Special notes for your reviewer:

• original race condition logs in unit test with go test -race:

=== RUN   TestEnsureBackendPoolDeletedConcurrently
W1221 07:57:03.975735   26563 azure_vmssflex_cache.go:59] failed to get the ID of VMSS Flex
W1221 07:57:03.975783   26563 azure_vmssflex_cache.go:59] failed to get the ID of VMSS Flex
==================
WARNING: DATA RACE
Write at 0x00c000596510 by goroutine 719:
  runtime.mapassign_faststr()
      /usr/local/go/src/runtime/map_faststr.go:203 +0x0
  sigs.k8s.io/cloud-provider-azure/pkg/provider.(*lockMap).addEntry()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_utils.go:79 +0xca
  sigs.k8s.io/cloud-provider-azure/pkg/provider.(*lockMap).LockEntry()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_utils.go:60 +0x7a
  sigs.k8s.io/cloud-provider-azure/pkg/provider.(*ScaleSet).DeleteCacheForNode()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_vmss_cache.go:279 +0x412
  sigs.k8s.io/cloud-provider-azure/pkg/provider.(*ScaleSet).ensureBackendPoolDeleted.func2()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_vmss.go:1926 +0x4c
  runtime.deferreturn()
      /usr/local/go/src/runtime/panic.go:476 +0x32
  sigs.k8s.io/cloud-provider-azure/pkg/provider.(*ScaleSet).EnsureBackendPoolDeleted()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_vmss.go:2034 +0x2e9
  sigs.k8s.io/cloud-provider-azure/pkg/provider.TestEnsureBackendPoolDeletedConcurrently.func1()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_vmss_test.go:2717 +0x164
  k8s.io/apimachinery/pkg/util/errors.AggregateGoroutines.func1()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/vendor/k8s.io/apimachinery/pkg/util/errors/errors.go:237 +0x35
  k8s.io/apimachinery/pkg/util/errors.AggregateGoroutines.func2()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/vendor/k8s.io/apimachinery/pkg/util/errors/errors.go:237 +0x47

Previous read at 0x00c000596510 by goroutine 718:
  runtime.mapaccess1_faststr()
      /usr/local/go/src/runtime/map_faststr.go:13 +0x0
  sigs.k8s.io/cloud-provider-azure/pkg/provider.(*lockMap).lockEntry()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_utils.go:83 +0x138
  sigs.k8s.io/cloud-provider-azure/pkg/provider.(*lockMap).LockEntry()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_utils.go:64 +0x10f
  sigs.k8s.io/cloud-provider-azure/pkg/provider.(*ScaleSet).getVMManagementTypeByNodeName()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_vmss_cache.go:390 +0x127
  sigs.k8s.io/cloud-provider-azure/pkg/provider.(*ScaleSet).DeleteCacheForNode()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_vmss_cache.go:257 +0x78
  sigs.k8s.io/cloud-provider-azure/pkg/provider.(*ScaleSet).ensureBackendPoolDeleted.func2()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_vmss.go:1926 +0x4c
  runtime.deferreturn()
      /usr/local/go/src/runtime/panic.go:476 +0x32
  sigs.k8s.io/cloud-provider-azure/pkg/provider.(*ScaleSet).EnsureBackendPoolDeleted()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_vmss.go:2034 +0x2e9
  sigs.k8s.io/cloud-provider-azure/pkg/provider.TestEnsureBackendPoolDeletedConcurrently.func1()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_vmss_test.go:2717 +0x164
  k8s.io/apimachinery/pkg/util/errors.AggregateGoroutines.func1()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/vendor/k8s.io/apimachinery/pkg/util/errors/errors.go:237 +0x35
  k8s.io/apimachinery/pkg/util/errors.AggregateGoroutines.func2()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/vendor/k8s.io/apimachinery/pkg/util/errors/errors.go:237 +0x47

Goroutine 719 (running) created at:
  k8s.io/apimachinery/pkg/util/errors.AggregateGoroutines()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/vendor/k8s.io/apimachinery/pkg/util/errors/errors.go:237 +0x69
  sigs.k8s.io/cloud-provider-azure/pkg/provider.TestEnsureBackendPoolDeletedConcurrently()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_vmss_test.go:2721 +0x2bb9
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:1446 +0x216
  testing.(*T).Run.func1()
      /usr/local/go/src/testing/testing.go:1493 +0x47

Goroutine 718 (running) created at:
  k8s.io/apimachinery/pkg/util/errors.AggregateGoroutines()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/vendor/k8s.io/apimachinery/pkg/util/errors/errors.go:237 +0x69
  sigs.k8s.io/cloud-provider-azure/pkg/provider.TestEnsureBackendPoolDeletedConcurrently()
      /home/prow/go/src/sigs.k8s.io/cloud-provider-azure/pkg/provider/azure_vmss_test.go:2721 +0x2bb9
  testing.tRunner()
      /usr/local/go/src/testing/testing.go:1446 +0x216
  testing.(*T).Run.func1()
      /usr/local/go/src/testing/testing.go:1493 +0x47
==================
    testing.go:1319: race detected during execution of test
--- FAIL: TestEnsureBackendPoolDeletedConcurrently (0.01s)

Does this PR introduce a user-facing change?

fix: race condition in lockMap

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

fix: race condition in lockMap

[k8s-ci-robot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: andyzhangx

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• OWNERS [andyzhangx]

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[netlify]

✅ Deploy Preview for kubernetes-sigs-cloud-provide-azure canceled.

Name	Link
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[coveralls]

Coverage decreased (-0.001%) to 79.368% when pulling afc4cb3 on andyzhangx:fix-race-condition into 8eb4cb1 on kubernetes-sigs:master.

[andyzhangx]

/retest

[feiskyer]

Good catch. I thought race conditions should have already been covered since 'go test -race' is already running. Thanks for adding a new race condition test.

[feiskyer]

/lgtm