add necessary protection err, fileInfo slice reads and writes (#18854)

protection was in place. However, it covered only some
areas, so we re-arranged the code to ensure we could hold
locks properly.

Along with this, remove the DataShardFix code altogether,
in deployments with many drive replacements, this can affect
and lead to quorum loss.

cmd/common-main.go

@@ -69,8 +69,6 @@ import (
 // serverDebugLog will enable debug printing
 var serverDebugLog = env.Get("_MINIO_SERVER_DEBUG", config.EnableOff) == config.EnableOn
 
-var shardDiskTimeDelta time.Duration
-
 func init() {
 	if runtime.GOOS == "windows" {
 		if mousetrap.StartedByExplorer() {
@@ -107,12 +105,6 @@ func init() {
 	gob.Register(madmin.XFSErrorConfigs{})
 	gob.Register(map[string]interface{}{})
 
-	var err error
-	shardDiskTimeDelta, err = time.ParseDuration(env.Get("_MINIO_SHARD_DISKTIME_DELTA", "1m"))
-	if err != nil {
-		shardDiskTimeDelta = 1 * time.Minute
-	}
-
 	// All minio-go and madmin-go API operations shall be performed only once,
 	// another way to look at this is we are turning off retries.
 	minio.MaxRetry = 1