fix: refactor locks to apply them uniquely per node (#11052)

This refactor is done for few reasons below

- to avoid deadlocks in scenarios when number
  of nodes are smaller < actual erasure stripe
  count where in N participating local lockers
  can lead to deadlocks across systems.

- avoids expiry routines to run 1000 of separate
  network operations and routes per disk where
  as each of them are still accessing one single
  local entity.

- it is ideal to have since globalLockServer
  per instance.

- In a 32node deployment however, each server
  group is still concentrated towards the
  same set of lockers that partipicate during
  the write/read phase, unlike previous minio/dsync
  implementation - this potentially avoids send
  32 requests instead we will still send at max
  requests of unique nodes participating in a
  write/read phase.

- reduces overall chattiness on smaller setups.

cmd/local-locker.go

@@ -46,13 +46,12 @@ func isWriteLock(lri []lockRequesterInfo) bool {
 
 // localLocker implements Dsync.NetLocker
 type localLocker struct {
-	mutex    sync.Mutex
-	endpoint Endpoint
-	lockMap  map[string][]lockRequesterInfo
+	mutex   sync.Mutex
+	lockMap map[string][]lockRequesterInfo
 }
 
 func (l *localLocker) String() string {
-	return l.endpoint.String()
+	return globalEndpoints.Localhost()
 }
 
 func (l *localLocker) canTakeUnlock(resources ...string) bool {
@@ -194,7 +193,7 @@ func (l *localLocker) DupLockMap() map[string][]lockRequesterInfo {
 	l.mutex.Lock()
 	defer l.mutex.Unlock()
 
-	lockCopy := make(map[string][]lockRequesterInfo)
+	lockCopy := map[string][]lockRequesterInfo{}
 	for k, v := range l.lockMap {
 		lockCopy[k] = append(lockCopy[k], v...)
 	}
@@ -253,9 +252,8 @@ func (l *localLocker) removeEntryIfExists(nlrip nameLockRequesterInfoPair) {
 	}
 }
 
-func newLocker(endpoint Endpoint) *localLocker {
+func newLocker() *localLocker {
 	return &localLocker{
-		endpoint: endpoint,
-		lockMap:  make(map[string][]lockRequesterInfo),
+		lockMap: make(map[string][]lockRequesterInfo),
 	}
 }