Deprecate ListLocks and ClearLocks (#6233)

No locks are ever left in memory, we also
have a periodic interval of clearing stale locks
anyways. The lock instrumentation was not complete
and was seldom used.

Deprecate this for now and bring it back later if
it is really needed. This also in-turn seems to improve
performance slightly.

cmd/local-admin-client_test.go

@@ -17,10 +17,7 @@
 package cmd
 
 import (
-	"fmt"
-	"os"
 	"testing"
-	"time"
 )
 
 func TestLocalAdminClientSignalService(t *testing.T) {
@@ -31,10 +28,6 @@ func TestLocalAdminClientReInitFormat(t *testing.T) {
 	testAdminCmdRunnerReInitFormat(t, &localAdminClient{})
 }
 
-func TestLocalAdminClientListLocks(t *testing.T) {
-	testAdminCmdRunnerListLocks(t, &localAdminClient{})
-}
-
 func TestLocalAdminClientServerInfo(t *testing.T) {
 	testAdminCmdRunnerServerInfo(t, &localAdminClient{})
 }
@@ -50,91 +43,3 @@ func TestLocalAdminClientWriteTmpConfig(t *testing.T) {
 func TestLocalAdminClientCommitConfig(t *testing.T) {
 	testAdminCmdRunnerCommitConfig(t, &localAdminClient{})
 }
-
-func TestListLocksInfo(t *testing.T) {
-	// reset global variables to start afresh.
-	resetTestGlobals()
-	// Initialize minio server config.
-	rootPath, err := newTestConfig(globalMinioDefaultRegion)
-	if err != nil {
-		t.Fatal(err)
-	}
-	defer os.RemoveAll(rootPath)
-
-	// Initializing new XL objectLayer.
-	objAPI, _, xlErr := initTestXLObjLayer()
-	if xlErr != nil {
-		t.Fatalf("failed to init object layer")
-	}
-	// Make objLayer available to all internal services via globalObjectAPI.
-	globalObjLayerMutex.Lock()
-	globalObjectAPI = objAPI
-	globalObjLayerMutex.Unlock()
-	// Set globalIsXL to indicate that the setup uses an erasure code backend.
-	// initialize NSLock.
-	isDistXL := false
-	initNSLock(isDistXL)
-
-	var nsMutex *nsLockMap
-
-	nsMutex = objAPI.(*xlSets).sets[0].nsMutex
-
-	// Acquire a few locks to populate lock instrumentation.
-	// Take 10 read locks on bucket1/prefix1/obj1
-	for i := 0; i < 10; i++ {
-		readLk := nsMutex.NewNSLock("bucket1", "prefix1/obj1")
-		if readLk.GetRLock(newDynamicTimeout(60*time.Second, time.Second)) != nil {
-			t.Errorf("Failed to get read lock on iteration %d", i)
-		}
-	}
-
-	// Take write locks on bucket1/prefix/obj{11..19}
-	for i := 0; i < 10; i++ {
-		wrLk := nsMutex.NewNSLock("bucket1", fmt.Sprintf("prefix1/obj%d", 10+i))
-		if wrLk.GetLock(newDynamicTimeout(60*time.Second, time.Second)) != nil {
-			t.Errorf("Failed to get write lock on iteration %d", i)
-		}
-	}
-
-	client := &localAdminClient{}
-
-	testCases := []struct {
-		bucket   string
-		prefix   string
-		duration time.Duration
-		numLocks int
-	}{
-		// Test 1 - Matches all the locks acquired above.
-		{
-			bucket:   "bucket1",
-			prefix:   "prefix1",
-			duration: time.Duration(0 * time.Second),
-			numLocks: 20,
-		},
-		// Test 2 - Bucket doesn't match.
-		{
-			bucket:   "bucket",
-			prefix:   "prefix1",
-			duration: time.Duration(0 * time.Second),
-			numLocks: 0,
-		},
-		// Test 3 - Prefix doesn't match.
-		{
-			bucket:   "bucket1",
-			prefix:   "prefix11",
-			duration: time.Duration(0 * time.Second),
-			numLocks: 0,
-		},
-	}
-
-	for i, test := range testCases {
-		actual, err := client.ListLocks(test.bucket, test.prefix, test.duration)
-		if err != nil {
-			t.Fatalf("unexpected error %v", err)
-		}
-		if len(actual) != test.numLocks {
-			t.Errorf("Test %d - Expected %d locks but observed %d locks",
-				i+1, test.numLocks, len(actual))
-		}
-	}
-}