Support MinIO to be deployed on more than 32 nodes (#8492)

This PR implements locking from a global entity into
a more localized set level entity, allowing for locks
to be held only on the resources which are writing
to a collection of disks rather than a global level.

In this process this PR also removes the top-level
limit of 32 nodes to an unlimited number of nodes. This
is a precursor change before bring in bucket expansion.

cmd/admin-handlers_test.go

@@ -27,7 +27,6 @@ import (
 	"net/url"
 	"sync"
 	"testing"
-	"time"
 
 	"github.com/gorilla/mux"
 	"github.com/minio/minio/pkg/auth"
@@ -68,10 +67,6 @@ func prepareAdminXLTestBed() (*adminXLTestBed, error) {
 	// code backend.
 	globalIsXL = true
 
-	// initialize NSLock.
-	isDistXL := false
-	initNSLock(isDistXL)
-
 	// Init global heal state
 	if globalIsXL {
 		globalAllHealState = initHealState()
@@ -345,46 +340,6 @@ func TestToAdminAPIErrCode(t *testing.T) {
 	}
 }
 
-func TestTopLockEntries(t *testing.T) {
-	t1 := UTCNow()
-	t2 := UTCNow().Add(10 * time.Second)
-	peerLocks := []*PeerLocks{
-		{
-			Addr: "1",
-			Locks: map[string][]lockRequesterInfo{
-				"1": {
-					{false, "node2", "ep2", "2", t2, t2, ""},
-					{true, "node1", "ep1", "1", t1, t1, ""},
-				},
-				"2": {
-					{false, "node2", "ep2", "2", t2, t2, ""},
-					{true, "node1", "ep1", "1", t1, t1, ""},
-				},
-			},
-		},
-		{
-			Addr: "2",
-			Locks: map[string][]lockRequesterInfo{
-				"1": {
-					{false, "node2", "ep2", "2", t2, t2, ""},
-					{true, "node1", "ep1", "1", t1, t1, ""},
-				},
-				"2": {
-					{false, "node2", "ep2", "2", t2, t2, ""},
-					{true, "node1", "ep1", "1", t1, t1, ""},
-				},
-			},
-		},
-	}
-	les := topLockEntries(peerLocks)
-	if len(les) != 2 {
-		t.Fatalf("Did not get 2 results")
-	}
-	if les[0].Timestamp.After(les[1].Timestamp) {
-		t.Fatalf("Got wrong sorted value")
-	}
-}
-
 func TestExtractHealInitParams(t *testing.T) {
 	mkParams := func(clientToken string, forceStart, forceStop bool) url.Values {
 		v := url.Values{}