lock: improve locker initialization at init (#8776)

Use reference format to initialize lockers
during startup, also handle `nil` for NetLocker
in dsync and remove *errorLocker* implementation

Add further tuning parameters such as

 - DialTimeout is now 15 seconds from 30 seconds
 - KeepAliveTimeout is not 20 seconds, 5 seconds
   more than default 15 seconds
 - ResponseHeaderTimeout to 10 seconds
 - ExpectContinueTimeout is reduced to 3 seconds
 - DualStack is enabled by default remove setting
   it to `true`
 - Reduce IdleConnTimeout to 30 seconds from
   1 minute to avoid idleConn build up

Fixes #8773

cmd/server-main.go

@@ -200,9 +200,6 @@ func initSafeMode(buckets []BucketInfo) (err error) {
 		}
 	}(objLock)
 
-	// Calls New() and initializes all sub-systems.
-	newAllSubsystems()
-
 	// Migrate all backend configs to encrypted backend configs, optionally
 	// handles rotating keys for encryption.
 	if err = handleEncryptedConfigBackend(newObject, true); err != nil {
@@ -365,6 +362,16 @@ func serverMain(ctx *cli.Context) {
 	globalObjectAPI = newObject
 	globalObjLayerMutex.Unlock()
 
+	// Calls New() and initializes all sub-systems.
+	newAllSubsystems()
+
+	// Enable healing to heal drives if possible
+	if globalIsXL {
+		initBackgroundHealing()
+		initLocalDisksAutoHeal()
+		initGlobalHeal()
+	}
+
 	buckets, err := newObject.ListBuckets(context.Background())
 	if err != nil {
 		logger.Fatal(err, "Unable to list buckets")
@@ -391,12 +398,6 @@ func serverMain(ctx *cli.Context) {
 	initDataUsageStats()
 	initDailyLifecycle()
 
-	if globalIsXL {
-		initBackgroundHealing()
-		initLocalDisksAutoHeal()
-		initGlobalHeal()
-	}
-
 	// Disable safe mode operation, after all initialization is over.
 	globalObjLayerMutex.Lock()
 	globalSafeMode = false