further improvements to newXLStorage (#14166)

- create internal erasure volumes only if the disk is unformatted
- return a copy of format data in xlStorage.ReadAll
- parse env vars only once, to be re-used by xl-storage

cmd/common-main.go

@@ -40,6 +40,7 @@ import (
 	"syscall"
 	"time"
 
+	"github.com/dustin/go-humanize"
 	fcolor "github.com/fatih/color"
 	"github.com/go-openapi/loads"
 	"github.com/inconshreveable/mousetrap"
@@ -652,6 +653,16 @@ func handleCommonEnvVars() {
 		logger.Fatal(config.ErrInvalidFSOSyncValue(err), "Invalid MINIO_FS_OSYNC value in environment variable")
 	}
 
+	if rootDiskSize := env.Get(config.EnvRootDiskThresholdSize, ""); rootDiskSize != "" {
+		size, err := humanize.ParseBytes(rootDiskSize)
+		if err != nil {
+			logger.Fatal(err, fmt.Sprintf("Invalid %s value in environment variable", config.EnvRootDiskThresholdSize))
+		}
+		globalRootDiskThreshold = size
+	}
+
+	globalIsCICD = env.Get("MINIO_CI_CD", "") != ""
+
 	domains := env.Get(config.EnvDomain, "")
 	if len(domains) != 0 {
 		for _, domainName := range strings.Split(domains, config.ValueSeparator) {

cmd/globals.go

@@ -341,6 +341,10 @@ var (
 	// List of local drives to this node, this is only set during server startup.
 	globalLocalDrives []StorageAPI
 
+	// Is MINIO_CI_CD set?
+	globalIsCICD bool
+
+	globalRootDiskThreshold uint64
 	// Add new variable global values here.
 )
 

cmd/xl-storage.go

@@ -41,12 +41,10 @@ import (
 	jsoniter "github.com/json-iterator/go"
 	"github.com/minio/minio/internal/bucket/lifecycle"
 	"github.com/minio/minio/internal/color"
-	"github.com/minio/minio/internal/config"
 	"github.com/minio/minio/internal/disk"
 	xioutil "github.com/minio/minio/internal/ioutil"
 	"github.com/minio/minio/internal/logger"
 	"github.com/minio/pkg/console"
-	"github.com/minio/pkg/env"
 	"github.com/yargevad/filepathx"
 )
 
@@ -215,38 +213,32 @@ func newXLStorage(ep Endpoint) (s *xlStorage, err error) {
 	}
 
 	var rootDisk bool
-	if env.Get("MINIO_CI_CD", "") != "" {
+	if globalIsCICD {
 		rootDisk = true
 	} else {
 		rootDisk, err = disk.IsRootDisk(path, SlashSeparator)
 		if err != nil {
 			return nil, err
 		}
-		if !rootDisk {
-			// If for some reason we couldn't detect the
-			// root disk use - MINIO_ROOTDISK_THRESHOLD_SIZE
-			// to figure out if the disk is root disk or not.
-			if rootDiskSize := env.Get(config.EnvRootDiskThresholdSize, ""); rootDiskSize != "" {
+		if !rootDisk && globalRootDiskThreshold > 0 {
+			// If for some reason we couldn't detect the root disk
+			// use - MINIO_ROOTDISK_THRESHOLD_SIZE to figure out if
+			// this disk is a root disk.
 			info, err := disk.GetInfo(path)
 			if err != nil {
 				return nil, err
 			}
-				size, err := humanize.ParseBytes(rootDiskSize)
-				if err != nil {
-					return nil, err
-				}
-				// size of the disk is less than the threshold or
-				// equal to the size of the disk at path, treat
-				// such disks as rootDisks and reject them.
-				rootDisk = info.Total <= size
-			}
+
+			// treat those disks with size less than or equal to the
+			// threshold as rootDisks.
+			rootDisk = info.Total <= globalRootDiskThreshold
 		}
 	}
 
 	s = &xlStorage{
 		diskPath:   path,
 		endpoint:   ep,
-		globalSync: env.Get(config.EnvFSOSync, config.EnableOff) == config.EnableOn,
+		globalSync: globalFSOSync,
 		rootDisk:   rootDisk,
 		poolIndex:  -1,
 		setIndex:   -1,
@@ -285,6 +277,11 @@ func newXLStorage(ep Endpoint) (s *xlStorage, err error) {
 			return s, err
 		}
 		Remove(filePath)
+
+		// Create all necessary bucket folders if possible.
+		if err = makeFormatErasureMetaVolumes(s); err != nil {
+			return nil, err
+		}
 	} else {
 		format := &formatErasureV3{}
 		json := jsoniter.ConfigCompatibleWithStandardLibrary
@@ -296,11 +293,6 @@ func newXLStorage(ep Endpoint) (s *xlStorage, err error) {
 		s.formatLegacy = format.Erasure.DistributionAlgo == formatErasureVersionV2DistributionAlgoV1
 	}
 
-	// Create all necessary bucket folders if possible.
-	if err = makeFormatErasureMetaVolumes(s); err != nil {
-		return nil, err
-	}
-
 	// Success.
 	return s, nil
 }
@@ -1423,7 +1415,8 @@ func (s *xlStorage) ReadAll(ctx context.Context, volume string, path string) (bu
 	// in-case the caller is a network operation.
 	if volume == minioMetaBucket && path == formatConfigFile {
 		s.RLock()
-		formatData := s.formatData
+		formatData := make([]byte, len(s.formatData))
+		copy(formatData, s.formatData)
 		s.RUnlock()
 		if len(formatData) > 0 {
 			return formatData, nil