feat: Single drive XL implementation (#14970)

Main motivation is move towards a common backend format
for all different types of modes in MinIO, allowing for
a simpler code and predictable behavior across all features.

This PR also brings features such as versioning, replication,
transitioning to single drive setups.

Makefile

@@ -53,7 +53,7 @@ test-iam: build ## verify IAM (external IDP, etcd backends)
 	@echo "Running tests for IAM (external IDP, etcd backends)"
 	@CGO_ENABLED=0 go test -tags kqueue -v -run TestIAM* ./cmd
 	@echo "Running tests for IAM (external IDP, etcd backends) with -race"
-	@CGO_ENABLED=1 go test -race -tags kqueue -v -run TestIAM* ./cmd
+	@GORACE=history_size=7 CGO_ENABLED=1 go test -race -tags kqueue -v -run TestIAM* ./cmd
 
 test-replication: install ## verify multi site replication
 	@echo "Running tests for replicating three sites"
@@ -73,18 +73,18 @@ test-site-replication-minio: install ## verify automatic site replication
 
 verify: ## verify minio various setups
 	@echo "Verifying build with race"
-	@CGO_ENABLED=1 go build -race -tags kqueue -trimpath --ldflags "$(LDFLAGS)" -o $(PWD)/minio 1>/dev/null
+	@GORACE=history_size=7 CGO_ENABLED=1 go build -race -tags kqueue -trimpath --ldflags "$(LDFLAGS)" -o $(PWD)/minio 1>/dev/null
 	@(env bash $(PWD)/buildscripts/verify-build.sh)
 
 verify-healing: ## verify healing and replacing disks with minio binary
 	@echo "Verify healing build with race"
-	@CGO_ENABLED=1 go build -race -tags kqueue -trimpath --ldflags "$(LDFLAGS)" -o $(PWD)/minio 1>/dev/null
+	@GORACE=history_size=7 CGO_ENABLED=1 go build -race -tags kqueue -trimpath --ldflags "$(LDFLAGS)" -o $(PWD)/minio 1>/dev/null
 	@(env bash $(PWD)/buildscripts/verify-healing.sh)
 	@(env bash $(PWD)/buildscripts/unaligned-healing.sh)
 
 verify-healing-inconsistent-versions: ## verify resolving inconsistent versions
 	@echo "Verify resolving inconsistent versions build with race"
-	@CGO_ENABLED=1 go build -race -tags kqueue -trimpath --ldflags "$(LDFLAGS)" -o $(PWD)/minio 1>/dev/null
+	@GORACE=history_size=7 CGO_ENABLED=1 go build -race -tags kqueue -trimpath --ldflags "$(LDFLAGS)" -o $(PWD)/minio 1>/dev/null
 	@(env bash $(PWD)/buildscripts/resolve-right-versions.sh)
 
 build: checks ## builds minio to $(PWD)

README.md

@@ -196,12 +196,6 @@ iptables -A INPUT -p tcp --dport 9000:9010 -j ACCEPT
 service iptables restart
 ```
 
-## Pre-existing data
-
-When deployed on a single drive, MinIO server lets clients access any pre-existing data in the data directory. For example, if MinIO is started with the command  `minio server /mnt/data`, any pre-existing data in the `/mnt/data` directory would be accessible to the clients.
-
-The above statement is also valid for all gateway backends.
-
 ## Test MinIO Connectivity
 
 ### Test using MinIO Console

buildscripts/race.sh

@@ -2,6 +2,7 @@
 
 set -e
 
+export GORACE="history_size=7"
 ## TODO remove `dsync` from race detector once this is merged and released https://go-review.googlesource.com/c/go/+/333529/
 for d in $(go list ./... | grep -v dsync); do
     CGO_ENABLED=1 go test -v -race --timeout 100m "$d"

cmd/admin-bucket-handlers.go

@@ -145,7 +145,7 @@ func (a adminAPIHandlers) SetRemoteTargetHandler(w http.ResponseWriter, r *http.
 	bucket := pathClean(vars["bucket"])
 	update := r.Form.Get("update") == "true"
 
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}
@@ -274,7 +274,8 @@ func (a adminAPIHandlers) ListRemoteTargetsHandler(w http.ResponseWriter, r *htt
 	vars := mux.Vars(r)
 	bucket := pathClean(vars["bucket"])
 	arnType := vars["type"]
-	if !globalIsErasure {
+
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}
@@ -314,7 +315,7 @@ func (a adminAPIHandlers) RemoveRemoteTargetHandler(w http.ResponseWriter, r *ht
 	bucket := pathClean(vars["bucket"])
 	arn := vars["arn"]
 
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}

cmd/admin-handlers-users-race_test.go

@@ -47,10 +47,10 @@ func TestIAMInternalIDPConcurrencyServerSuite(t *testing.T) {
 	}
 
 	baseTestCases := []TestSuiteCommon{
-		// Init and run test on FS backend with signature v4.
+		// Init and run test on ErasureSD backend with signature v4.
-		{serverType: "FS", signer: signerV4},
+		{serverType: "ErasureSD", signer: signerV4},
-		// Init and run test on FS backend, with tls enabled.
+		// Init and run test on ErasureSD backend, with tls enabled.
-		{serverType: "FS", signer: signerV4, secure: true},
+		{serverType: "ErasureSD", signer: signerV4, secure: true},
 		// Init and run test on Erasure backend.
 		{serverType: "Erasure", signer: signerV4},
 		// Init and run test on ErasureSet backend.

cmd/admin-handlers-users_test.go

@@ -102,10 +102,10 @@ func (s *TestSuiteIAM) iamSetup(c *check) {
 // common to tests.
 var iamTestSuites = func() []*TestSuiteIAM {
 	baseTestCases := []TestSuiteCommon{
-		// Init and run test on FS backend with signature v4.
+		// Init and run test on ErasureSD backend with signature v4.
-		{serverType: "FS", signer: signerV4},
+		{serverType: "ErasureSD", signer: signerV4},
-		// Init and run test on FS backend, with tls enabled.
+		// Init and run test on ErasureSD backend, with tls enabled.
-		{serverType: "FS", signer: signerV4, secure: true},
+		{serverType: "ErasureSD", signer: signerV4, secure: true},
 		// Init and run test on Erasure backend.
 		{serverType: "Erasure", signer: signerV4},
 		// Init and run test on ErasureSet backend.

cmd/admin-handlers.go

@@ -805,8 +805,7 @@ func (a adminAPIHandlers) HealHandler(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	// Check if this setup has an erasure coded backend.
+	if globalIsGateway {
-	if !globalIsErasure {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrHealNotImplemented), r.URL)
 		return
 	}
@@ -998,7 +997,7 @@ func (a adminAPIHandlers) BackgroundHealStatusHandler(w http.ResponseWriter, r *
 	}
 
 	// Check if this setup has an erasure coded backend.
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrHealNotImplemented), r.URL)
 		return
 	}
@@ -1078,7 +1077,7 @@ func (a adminAPIHandlers) ObjectSpeedtestHandler(w http.ResponseWriter, r *http.
 		return
 	}
 
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}
@@ -1228,7 +1227,7 @@ func (a adminAPIHandlers) DriveSpeedtestHandler(w http.ResponseWriter, r *http.R
 		return
 	}
 
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}

cmd/admin-router.go

@@ -170,7 +170,6 @@ func registerAdminRouter(router *mux.Router, enableConfigOps bool) {
 		// Set Group Status
 		adminRouter.Methods(http.MethodPut).Path(adminVersion+"/set-group-status").HandlerFunc(gz(httpTraceHdrs(adminAPI.SetGroupStatus))).Queries("group", "{group:.*}").Queries("status", "{status:.*}")
 
-		if globalIsDistErasure || globalIsErasure {
 		// GetBucketQuotaConfig
 		adminRouter.Methods(http.MethodGet).Path(adminVersion+"/get-bucket-quota").HandlerFunc(
 			gz(httpTraceHdrs(adminAPI.GetBucketQuotaConfigHandler))).Queries("bucket", "{bucket:.*}")
@@ -213,7 +212,6 @@ func registerAdminRouter(router *mux.Router, enableConfigOps bool) {
 		adminRouter.Methods(http.MethodPut).Path(adminVersion + "/site-replication/edit").HandlerFunc(gz(httpTraceHdrs(adminAPI.SiteReplicationEdit)))
 		adminRouter.Methods(http.MethodPut).Path(adminVersion + "/site-replication/peer/edit").HandlerFunc(gz(httpTraceHdrs(adminAPI.SRPeerEdit)))
 		adminRouter.Methods(http.MethodPut).Path(adminVersion + "/site-replication/peer/remove").HandlerFunc(gz(httpTraceHdrs(adminAPI.SRPeerRemove)))
-		}
 
 		if globalIsDistErasure {
 			// Top locks

cmd/bucket-handlers.go

@@ -1364,7 +1364,7 @@ func (api objectAPIHandlers) PutBucketObjectLockConfigHandler(w http.ResponseWri
 		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrServerNotInitialized), r.URL)
 		return
 	}
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}
@@ -1611,7 +1611,7 @@ func (api objectAPIHandlers) PutBucketReplicationConfigHandler(w http.ResponseWr
 		writeErrorResponse(ctx, w, errorCodes.ToAPIErr(ErrServerNotInitialized), r.URL)
 		return
 	}
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}

cmd/bucket-metadata-sys.go

@@ -127,20 +127,11 @@ func (sys *BucketMetadataSys) Update(ctx context.Context, bucket string, configF
 		meta.QuotaConfigJSON = configData
 		meta.QuotaConfigUpdatedAt = UTCNow()
 	case objectLockConfig:
-		if !globalIsErasure && !globalIsDistErasure {
-			return NotImplemented{}
-		}
 		meta.ObjectLockConfigXML = configData
 		meta.ObjectLockConfigUpdatedAt = UTCNow()
 	case bucketVersioningConfig:
-		if !globalIsErasure && !globalIsDistErasure {
-			return NotImplemented{}
-		}
 		meta.VersioningConfigXML = configData
 	case bucketReplicationConfig:
-		if !globalIsErasure && !globalIsDistErasure {
-			return NotImplemented{}
-		}
 		meta.ReplicationConfigXML = configData
 		meta.ReplicationConfigUpdatedAt = UTCNow()
 	case bucketTargetsFile:

cmd/bucket-replication.go

@@ -2187,10 +2187,6 @@ func (p *ReplicationPool) initResync(ctx context.Context, buckets []BucketInfo,
 	if objAPI == nil {
 		return errServerNotInitialized
 	}
-	// replication applies only to erasure coded setups
-	if !globalIsErasure {
-		return nil
-	}
 	// Load bucket metadata sys in background
 	go p.loadResync(ctx, buckets, objAPI)
 	return nil

cmd/bucket-targets.go

@@ -120,9 +120,6 @@ func (sys *BucketTargetSys) SetTarget(ctx context.Context, bucket string, tgt *m
 		return BucketRemoteConnectionErr{Bucket: tgt.TargetBucket, Err: err}
 	}
 	if tgt.Type == madmin.ReplicationService {
-		if !globalIsErasure {
-			return NotImplemented{Message: "Replication is not implemented in " + getMinioMode()}
-		}
 		if !globalBucketVersioningSys.Enabled(bucket) {
 			return BucketReplicationSourceNotVersioned{Bucket: bucket}
 		}
@@ -184,9 +181,6 @@ func (sys *BucketTargetSys) RemoveTarget(ctx context.Context, bucket, arnStr str
 	if globalIsGateway {
 		return nil
 	}
-	if !globalIsErasure {
-		return NotImplemented{Message: "Replication is not implemented in " + getMinioMode()}
-	}
 
 	if arnStr == "" {
 		return BucketRemoteArnInvalid{Bucket: bucket}

cmd/endpoint.go

@@ -582,7 +582,7 @@ func CreateEndpoints(serverAddr string, foundLocal bool, args ...[]string) (Endp
 			return endpoints, setupType, config.ErrInvalidFSEndpoint(nil).Msg("use path style endpoint for FS setup")
 		}
 		endpoints = append(endpoints, endpoint)
-		setupType = FSSetupType
+		setupType = ErasureSDSetupType
 
 		// Check for cross device mounts if any.
 		if err = checkCrossDeviceMounts(endpoints); err != nil {

cmd/endpoint_test.go

@@ -231,10 +231,10 @@ func TestCreateEndpoints(t *testing.T) {
 	}{
 		{"localhost", [][]string{}, "", Endpoints{}, -1, fmt.Errorf("address localhost: missing port in address")},
 
-		// FS Setup
+		// Erasure Single Drive
 		{"localhost:9000", [][]string{{"http://localhost/d1"}}, "", Endpoints{}, -1, fmt.Errorf("use path style endpoint for FS setup")},
-		{":443", [][]string{{"/d1"}}, ":443", Endpoints{Endpoint{URL: &url.URL{Path: mustAbs("/d1")}, IsLocal: true}}, FSSetupType, nil},
+		{":443", [][]string{{"/d1"}}, ":443", Endpoints{Endpoint{URL: &url.URL{Path: mustAbs("/d1")}, IsLocal: true}}, ErasureSDSetupType, nil},
-		{"localhost:10000", [][]string{{"/d1"}}, "localhost:10000", Endpoints{Endpoint{URL: &url.URL{Path: mustAbs("/d1")}, IsLocal: true}}, FSSetupType, nil},
+		{"localhost:10000", [][]string{{"/d1"}}, "localhost:10000", Endpoints{Endpoint{URL: &url.URL{Path: mustAbs("/d1")}, IsLocal: true}}, ErasureSDSetupType, nil},
 		{"localhost:9000", [][]string{{"https://127.0.0.1:9000/d1", "https://localhost:9001/d1", "https://example.com/d1", "https://example.com/d2"}}, "", Endpoints{}, -1, fmt.Errorf("path '/d1' can not be served by different port on same address")},
 
 		// Erasure Setup with PathEndpointType

cmd/erasure-coding.go

@@ -41,7 +41,7 @@ type Erasure struct {
 // NewErasure creates a new ErasureStorage.
 func NewErasure(ctx context.Context, dataBlocks, parityBlocks int, blockSize int64) (e Erasure, err error) {
 	// Check the parameters for sanity now.
-	if dataBlocks <= 0 || parityBlocks <= 0 {
+	if dataBlocks <= 0 || parityBlocks < 0 {
 		return e, reedsolomon.ErrInvShardNum
 	}
 

cmd/erasure-metadata.go

@@ -99,7 +99,7 @@ func (fi FileInfo) IsValid() bool {
 		fi.Erasure.Index <= dataBlocks+parityBlocks &&
 		len(fi.Erasure.Distribution) == (dataBlocks+parityBlocks))
 	return ((dataBlocks >= parityBlocks) &&
-		(dataBlocks != 0) && (parityBlocks != 0) &&
+		(dataBlocks > 0) && (parityBlocks >= 0) &&
 		correctIndexes)
 }
 
@@ -284,7 +284,7 @@ func (fi FileInfo) ObjectToPartOffset(ctx context.Context, offset int64) (partIn
 
 func findFileInfoInQuorum(ctx context.Context, metaArr []FileInfo, modTime time.Time, quorum int) (FileInfo, error) {
 	// with less quorum return error.
-	if quorum < 2 {
+	if quorum < 1 {
 		return FileInfo{}, errErasureReadQuorum
 	}
 	metaHashes := make([]string, len(metaArr))
@@ -398,6 +398,10 @@ func writeUniqueFileInfo(ctx context.Context, disks []StorageAPI, bucket, prefix
 // readQuorum is the min required disks to read data.
 // writeQuorum is the min required disks to write data.
 func objectQuorumFromMeta(ctx context.Context, partsMetaData []FileInfo, errs []error, defaultParityCount int) (objectReadQuorum, objectWriteQuorum int, err error) {
+	if defaultParityCount == 0 {
+		return 1, 1, nil
+	}
+
 	// get the latest updated Metadata and a count of all the latest updated FileInfo(s)
 	latestFileInfo, err := getLatestFileInfo(ctx, partsMetaData, errs)
 	if err != nil {

cmd/erasure-object.go

@@ -1327,12 +1327,17 @@ func (er erasureObjects) DeleteObjects(ctx context.Context, bucket string, objec
 func (er erasureObjects) deletePrefix(ctx context.Context, bucket, prefix string) error {
 	disks := er.getDisks()
 	g := errgroup.WithNErrs(len(disks))
+	dirPrefix := encodeDirObject(prefix)
 	for index := range disks {
 		index := index
 		g.Go(func() error {
 			if disks[index] == nil {
 				return nil
 			}
+			// Deletes
+			// - The prefix and its children
+			// - The prefix__XLDIR__
+			defer disks[index].Delete(ctx, bucket, dirPrefix, true)
 			return disks[index].Delete(ctx, bucket, prefix, true)
 		}, index)
 	}

cmd/erasure-server-pool.go

@@ -61,6 +61,22 @@ func (z *erasureServerPools) SinglePool() bool {
 
 // Initialize new pool of erasure sets.
 func newErasureServerPools(ctx context.Context, endpointServerPools EndpointServerPools) (ObjectLayer, error) {
+	if endpointServerPools.NEndpoints() == 1 {
+		ep := endpointServerPools[0]
+		storageDisks, format, err := waitForFormatErasure(true, ep.Endpoints, 1, ep.SetCount, ep.DrivesPerSet, "", "")
+		if err != nil {
+			return nil, err
+		}
+
+		objLayer, err := newErasureSingle(ctx, storageDisks[0], format)
+		if err != nil {
+			return nil, err
+		}
+
+		globalLocalDrives = storageDisks
+		return objLayer, nil
+	}
+
 	var (
 		deploymentID       string
 		distributionAlgo   string
@@ -320,7 +336,7 @@ func (z *erasureServerPools) getServerPoolsAvailableSpace(ctx context.Context, b
 		nSets[index] = pool.setCount
 		g.Go(func() error {
 			// Get the set where it would be placed.
-			storageInfos[index] = getDiskInfos(ctx, pool.getHashedSet(object).getDisks())
+			storageInfos[index] = getDiskInfos(ctx, pool.getHashedSet(object).getDisks()...)
 			return nil
 		}, index)
 	}
@@ -933,7 +949,7 @@ func (z *erasureServerPools) PutObject(ctx context.Context, bucket string, objec
 	object = encodeDirObject(object)
 
 	if z.SinglePool() {
-		if !isMinioMetaBucketName(bucket) && !hasSpaceFor(getDiskInfos(ctx, z.serverPools[0].getHashedSet(object).getDisks()), data.Size()) {
+		if !isMinioMetaBucketName(bucket) && !hasSpaceFor(getDiskInfos(ctx, z.serverPools[0].getHashedSet(object).getDisks()...), data.Size()) {
 			return ObjectInfo{}, toObjectErr(errDiskFull)
 		}
 		return z.serverPools[0].PutObject(ctx, bucket, object, data, opts)
@@ -1325,7 +1341,7 @@ func (z *erasureServerPools) NewMultipartUpload(ctx context.Context, bucket, obj
 	}
 
 	if z.SinglePool() {
-		if !isMinioMetaBucketName(bucket) && !hasSpaceFor(getDiskInfos(ctx, z.serverPools[0].getHashedSet(object).getDisks()), -1) {
+		if !isMinioMetaBucketName(bucket) && !hasSpaceFor(getDiskInfos(ctx, z.serverPools[0].getHashedSet(object).getDisks()...), -1) {
 			return "", toObjectErr(errDiskFull)
 		}
 		return z.serverPools[0].NewMultipartUpload(ctx, bucket, object, opts)

cmd/erasure-sets.go

@@ -1252,7 +1252,7 @@ func (s *erasureSets) HealFormat(ctx context.Context, dryRun bool) (res madmin.H
 
 	defer func(storageDisks []StorageAPI) {
 		if err != nil {
-			closeStorageDisks(storageDisks)
+			closeStorageDisks(storageDisks...)
 		}
 	}(storageDisks)
 

cmd/erasure.go

@@ -79,7 +79,7 @@ func (er erasureObjects) NewNSLock(bucket string, objects ...string) RWLocker {
 // Shutdown function for object storage interface.
 func (er erasureObjects) Shutdown(ctx context.Context) error {
 	// Add any object layer shutdown activities here.
-	closeStorageDisks(er.getDisks())
+	closeStorageDisks(er.getDisks()...)
 	return nil
 }
 

cmd/format-erasure.go

@@ -40,6 +40,9 @@ const (
 	// Represents Erasure backend.
 	formatBackendErasure = "xl"
 
+	// Represents Erasure backend - single drive
+	formatBackendErasureSingle = "xl-single"
+
 	// formatErasureV1.Erasure.Version - version '1'.
 	formatErasureVersionV1 = "1"
 
@@ -146,6 +149,9 @@ func newFormatErasureV3(numSets int, setLen int) *formatErasureV3 {
 	format := &formatErasureV3{}
 	format.Version = formatMetaVersionV1
 	format.Format = formatBackendErasure
+	if setLen == 1 {
+		format.Format = formatBackendErasureSingle
+	}
 	format.ID = mustGetUUID()
 	format.Erasure.Version = formatErasureVersionV3
 	format.Erasure.DistributionAlgo = formatErasureVersionV3DistributionAlgoV3
@@ -170,8 +176,8 @@ func formatGetBackendErasureVersion(b []byte) (string, error) {
 	if meta.Version != formatMetaVersionV1 {
 		return "", fmt.Errorf(`format.Version expected: %s, got: %s`, formatMetaVersionV1, meta.Version)
 	}
-	if meta.Format != formatBackendErasure {
+	if meta.Format != formatBackendErasure && meta.Format != formatBackendErasureSingle {
-		return "", fmt.Errorf(`found backend type %s, expected %s`, meta.Format, formatBackendErasure)
+		return "", fmt.Errorf(`found backend type %s, expected %s or %s`, meta.Format, formatBackendErasure, formatBackendErasureSingle)
 	}
 	// Erasure backend found, proceed to detect version.
 	format := &formatErasureVersionDetect{}
@@ -291,7 +297,7 @@ func formatErasureMigrateV2ToV3(data []byte, export, version string) ([]byte, er
 func countErrs(errs []error, err error) int {
 	i := 0
 	for _, err1 := range errs {
-		if err1 == err {
+		if err1 == err || errors.Is(err1, err) {
 			i++
 		}
 	}
@@ -410,7 +416,7 @@ func checkFormatErasureValue(formatErasure *formatErasureV3, disk StorageAPI) er
 	if formatErasure.Version != formatMetaVersionV1 {
 		return fmt.Errorf("Unsupported version of backend format [%s] found on %s", formatErasure.Version, disk)
 	}
-	if formatErasure.Format != formatBackendErasure {
+	if formatErasure.Format != formatBackendErasure && formatErasure.Format != formatBackendErasureSingle {
 		return fmt.Errorf("Unsupported backend format [%s] found on %s", formatErasure.Format, disk)
 	}
 	if formatErasure.Erasure.Version != formatErasureVersionV3 {
@@ -643,7 +649,7 @@ func saveFormatErasureAll(ctx context.Context, storageDisks []StorageAPI, format
 }
 
 // relinquishes the underlying connection for all storage disks.
-func closeStorageDisks(storageDisks []StorageAPI) {
+func closeStorageDisks(storageDisks ...StorageAPI) {
 	var wg sync.WaitGroup
 	for _, disk := range storageDisks {
 		if disk == nil {

cmd/format-fs.go

@@ -240,6 +240,9 @@ func initFormatFS(ctx context.Context, fsPath string) (rlk *lock.RLockedFile, er
 		if err != nil {
 			return nil, err
 		}
+		if formatBackend == formatBackendErasureSingle {
+			return nil, errFreshDisk
+		}
 		if formatBackend != formatBackendFS {
 			return nil, fmt.Errorf(`%s file: expected format-type: %s, found: %s`, formatConfigFile, formatBackendFS, formatBackend)
 		}
@@ -319,6 +322,10 @@ func formatFSFixDeploymentID(ctx context.Context, fsFormatPath string) error {
 		rlk.Close()
 		return err
 	}
+	if formatBackend == formatBackendErasureSingle {
+		rlk.Close()
+		return errFreshDisk
+	}
 	if formatBackend != formatBackendFS {
 		rlk.Close()
 		return fmt.Errorf(`%s file: expected format-type: %s, found: %s`, formatConfigFile, formatBackendFS, formatBackend)

cmd/fs-v1-metadata_test.go

@@ -45,6 +45,8 @@ func TestFSV1MetadataObjInfo(t *testing.T) {
 
 // TestReadFSMetadata - readFSMetadata testing with a healthy and faulty disk
 func TestReadFSMetadata(t *testing.T) {
+	t.Skip()
+
 	disk := filepath.Join(globalTestTmpDir, "minio-"+nextSuffix())
 	defer os.RemoveAll(disk)
 
@@ -80,6 +82,7 @@ func TestReadFSMetadata(t *testing.T) {
 
 // TestWriteFSMetadata - tests of writeFSMetadata with healthy disk.
 func TestWriteFSMetadata(t *testing.T) {
+	t.Skip()
 	disk := filepath.Join(globalTestTmpDir, "minio-"+nextSuffix())
 	defer os.RemoveAll(disk)
 

cmd/fs-v1-multipart_test.go

@@ -32,6 +32,7 @@ import (
 
 // Tests cleanup multipart uploads for filesystem backend.
 func TestFSCleanupMultipartUploadsInRoutine(t *testing.T) {
+	t.Skip()
 	// Prepare for tests
 	disk := filepath.Join(globalTestTmpDir, "minio-"+nextSuffix())
 	defer os.RemoveAll(disk)
@@ -88,6 +89,7 @@ func TestFSCleanupMultipartUploadsInRoutine(t *testing.T) {
 
 // TestNewMultipartUploadFaultyDisk - test NewMultipartUpload with faulty disks
 func TestNewMultipartUploadFaultyDisk(t *testing.T) {
+	t.Skip()
 	// Prepare for tests
 	disk := filepath.Join(globalTestTmpDir, "minio-"+nextSuffix())
 	defer os.RemoveAll(disk)

cmd/fs-v1.go

@@ -142,6 +142,11 @@ func NewFSObjectLayer(fsPath string) (ObjectLayer, error) {
 		return nil, config.ErrUnableToWriteInBackend(err).Hint(hint)
 	}
 
+	fsFormatPath := pathJoin(fsPath, minioMetaBucket, formatConfigFile)
+	if _, err = fsStat(ctx, fsFormatPath); err != nil && os.IsNotExist(err) {
+		return nil, errFreshDisk
+	}
+
 	// Assign a new UUID for FS minio mode. Each server instance
 	// gets its own UUID for temporary file transaction.
 	fsUUID := mustGetUUID()

cmd/fs-v1_test.go

@@ -51,6 +51,8 @@ func TestNewFS(t *testing.T) {
 // TestFSShutdown - initialize a new FS object layer then calls
 // Shutdown to check returned results
 func TestFSShutdown(t *testing.T) {
+	t.Skip()
+
 	bucketName := "testbucket"
 	objectName := "object"
 	// Create and return an fsObject with its path in the disk
@@ -83,6 +85,8 @@ func TestFSShutdown(t *testing.T) {
 
 // TestFSGetBucketInfo - test GetBucketInfo with healty and faulty disks
 func TestFSGetBucketInfo(t *testing.T) {
+	t.Skip()
+
 	// Prepare for testing
 	disk := filepath.Join(globalTestTmpDir, "minio-"+nextSuffix())
 	defer os.RemoveAll(disk)
@@ -165,6 +169,7 @@ func TestFSPutObject(t *testing.T) {
 
 // TestFSDeleteObject - test fs.DeleteObject() with healthy and corrupted disks
 func TestFSDeleteObject(t *testing.T) {
+	t.Skip()
 	// Prepare for tests
 	disk := filepath.Join(globalTestTmpDir, "minio-"+nextSuffix())
 	defer os.RemoveAll(disk)
@@ -209,6 +214,7 @@ func TestFSDeleteObject(t *testing.T) {
 
 // TestFSDeleteBucket - tests for fs DeleteBucket
 func TestFSDeleteBucket(t *testing.T) {
+	t.Skip()
 	// Prepare for testing
 	disk := filepath.Join(globalTestTmpDir, "minio-"+nextSuffix())
 	defer os.RemoveAll(disk)
@@ -249,6 +255,7 @@ func TestFSDeleteBucket(t *testing.T) {
 
 // TestFSListBuckets - tests for fs ListBuckets
 func TestFSListBuckets(t *testing.T) {
+	t.Skip()
 	// Prepare for tests
 	disk := filepath.Join(globalTestTmpDir, "minio-"+nextSuffix())
 	defer os.RemoveAll(disk)

cmd/gateway-main.go

@@ -19,6 +19,7 @@ package cmd
 
 import (
 	"context"
+	"errors"
 	"fmt"
 	"io/ioutil"
 	"log"
@@ -32,6 +33,7 @@ import (
 	"github.com/minio/cli"
 	"github.com/minio/madmin-go"
 	"github.com/minio/minio/internal/color"
+	"github.com/minio/minio/internal/config"
 	xhttp "github.com/minio/minio/internal/http"
 	"github.com/minio/minio/internal/logger"
 	"github.com/minio/pkg/certs"
@@ -292,6 +294,9 @@ func StartGateway(ctx *cli.Context, gw Gateway) {
 		SecretKey: globalActiveCred.SecretKey,
 	})
 	if err != nil {
+		if errors.Is(err, errFreshDisk) {
+			err = config.ErrInvalidFSValue(err)
+		}
 		logger.FatalIf(err, "Unable to initialize gateway backend")
 	}
 	newObject = NewGatewayLayerWithLocker(newObject)

cmd/global-heal.go

@@ -340,7 +340,9 @@ func (er *erasureObjects) healErasureSet(ctx context.Context, buckets []string,
 // healObject heals given object path in deep to fix bitrot.
 func healObject(bucket, object, versionID string, scan madmin.HealScanMode) {
 	// Get background heal sequence to send elements to heal
+	globalHealStateLK.Lock()
 	bgSeq, ok := globalBackgroundHealState.getHealSequenceByToken(bgHealingUUID)
+	globalHealStateLK.Unlock()
 	if ok {
 		bgSeq.queueHealTask(healSource{
 			bucket:    bucket,

cmd/globals.go

@@ -74,6 +74,7 @@ const (
 	globalWindowsOSName            = "windows"
 	globalMacOSName                = "darwin"
 	globalMinioModeFS              = "mode-server-fs"
+	globalMinioModeErasureSD       = "mode-server-xl-single"
 	globalMinioModeErasure         = "mode-server-xl"
 	globalMinioModeDistErasure     = "mode-server-distributed-xl"
 	globalMinioModeGatewayPrefix   = "mode-gateway-"
@@ -141,6 +142,9 @@ var (
 	// Indicates if the running minio server is an erasure-code backend.
 	globalIsErasure = false
 
+	// Indicates if the running minio server is in single drive XL mode.
+	globalIsErasureSD = false
+
 	// Indicates if the running minio is in gateway mode.
 	globalIsGateway = false
 

cmd/handler-api.go

@@ -116,10 +116,7 @@ func (t *apiConfig) init(cfg api.Config, setDriveCounts []int) {
 		//    + 2 * 10MiB (default erasure block size v1) + 2 * 1MiB (default erasure block size v2)
 		blockSize := xioutil.BlockSizeLarge + xioutil.BlockSizeSmall
 		apiRequestsMaxPerNode = int(maxMem / uint64(maxSetDrives*blockSize+int(blockSizeV1*2+blockSizeV2*2)))
-
-		if globalIsErasure {
 		logger.Info("Automatically configured API requests per node based on available memory on the system: %d", apiRequestsMaxPerNode)
-		}
 	} else {
 		apiRequestsMaxPerNode = cfg.RequestsMax
 		if len(globalEndpoints.Hostnames()) > 0 {

cmd/iam.go

@@ -314,18 +314,20 @@ func (sys *IAMSys) Init(ctx context.Context, objAPI ObjectLayer, etcdClient *etc
 		break
 	}
 
+	refreshInterval := sys.iamRefreshInterval
+
 	// Set up polling for expired accounts and credentials purging.
 	switch {
 	case sys.openIDConfig.ProviderEnabled():
 		go func() {
-			timer := time.NewTimer(sys.iamRefreshInterval)
+			timer := time.NewTimer(refreshInterval)
 			defer timer.Stop()
 			for {
 				select {
 				case <-timer.C:
 					sys.purgeExpiredCredentialsForExternalSSO(ctx)
 
-					timer.Reset(sys.iamRefreshInterval)
+					timer.Reset(refreshInterval)
 				case <-ctx.Done():
 					return
 				}
@@ -333,7 +335,7 @@ func (sys *IAMSys) Init(ctx context.Context, objAPI ObjectLayer, etcdClient *etc
 		}()
 	case sys.ldapConfig.Enabled:
 		go func() {
-			timer := time.NewTimer(sys.iamRefreshInterval)
+			timer := time.NewTimer(refreshInterval)
 			defer timer.Stop()
 
 			for {
@@ -342,7 +344,7 @@ func (sys *IAMSys) Init(ctx context.Context, objAPI ObjectLayer, etcdClient *etc
 					sys.purgeExpiredCredentialsForLDAP(ctx)
 					sys.updateGroupMembershipsForLDAP(ctx)
 
-					timer.Reset(sys.iamRefreshInterval)
+					timer.Reset(refreshInterval)
 				case <-ctx.Done():
 					return
 				}
@@ -717,7 +719,7 @@ func (sys *IAMSys) SetTempUser(ctx context.Context, accessKey string, cred auth.
 		return errServerNotInitialized
 	}
 
-	if globalAuthZPlugin != nil {
+	if newGlobalAuthZPluginFn() != nil {
 		// If OPA is set, we do not need to set a policy mapping.
 		policyName = ""
 	}
@@ -1690,8 +1692,8 @@ func (sys *IAMSys) GetCombinedPolicy(policies ...string) iampolicy.Policy {
 // IsAllowed - checks given policy args is allowed to continue the Rest API.
 func (sys *IAMSys) IsAllowed(args iampolicy.Args) bool {
 	// If opa is configured, use OPA always.
-	if globalAuthZPlugin != nil {
+	if authz := newGlobalAuthZPluginFn(); authz != nil {
-		ok, err := globalAuthZPlugin.IsAllowed(args)
+		ok, err := authz.IsAllowed(args)
 		if err != nil {
 			logger.LogIf(GlobalContext, err)
 		}

cmd/lock-rest-server.go

@@ -209,22 +209,7 @@ func (l *lockRESTServer) ForceUnlockHandler(w http.ResponseWriter, r *http.Reque
 // lockMaintenance loops over all locks and discards locks
 // that have not been refreshed for some time.
 func lockMaintenance(ctx context.Context) {
-	// Wait until the object API is ready
+	if !globalIsDistErasure {
-	// no need to start the lock maintenance
-	// if ObjectAPI is not initialized.
-
-	var objAPI ObjectLayer
-
-	for {
-		objAPI = newObjectLayerFn()
-		if objAPI == nil {
-			time.Sleep(time.Second)
-			continue
-		}
-		break
-	}
-
-	if _, ok := objAPI.(*erasureServerPools); !ok {
 		return
 	}
 

cmd/metacache-bucket.go

@@ -51,12 +51,14 @@ func newBucketMetacache(bucket string, cleanup bool) *bucketMetacache {
 	if cleanup {
 		// Recursively delete all caches.
 		objAPI := newObjectLayerFn()
-		ez, ok := objAPI.(*erasureServerPools)
+		if objAPI != nil {
+			ez, ok := objAPI.(renameAllStorager)
 			if ok {
 				ctx := context.Background()
 				ez.renameAll(ctx, minioMetaBucket, metacachePrefixForID(bucket, slashSeparator))
 			}
 		}
+	}
 	return &bucketMetacache{
 		bucket:     bucket,
 		caches:     make(map[string]metacache, 10),
@@ -207,9 +209,15 @@ func (b *bucketMetacache) cloneCaches() (map[string]metacache, map[string][]stri
 // Deletes are performed concurrently.
 func (b *bucketMetacache) deleteAll() {
 	ctx := context.Background()
-	ez, ok := newObjectLayerFn().(*erasureServerPools)
+
+	objAPI := newObjectLayerFn()
+	if objAPI == nil {
+		return
+	}
+
+	ez, ok := objAPI.(renameAllStorager)
 	if !ok {
-		logger.LogIf(ctx, errors.New("bucketMetacache: expected objAPI to be *erasurePools"))
+		logger.LogIf(ctx, errors.New("bucketMetacache: expected objAPI to be 'renameAllStorager'"))
 		return
 	}
 

cmd/metacache-manager.go

@@ -56,7 +56,7 @@ func (m *metacacheManager) initManager() {
 			objAPI = newObjectLayerFn()
 		}
 
-		if !globalIsErasure {
+		if globalIsGateway {
 			return
 		}
 

cmd/metacache-server-pool.go

@@ -259,6 +259,286 @@ func (z *erasureServerPools) listPath(ctx context.Context, o *listPathOptions) (
 	return entries, nil
 }
 
+// listPath will return the requested entries.
+// If no more entries are in the listing io.EOF is returned,
+// otherwise nil or an unexpected error is returned.
+// The listPathOptions given will be checked and modified internally.
+// Required important fields are Bucket, Prefix, Separator.
+// Other important fields are Limit, Marker.
+// List ID always derived from the Marker.
+func (es *erasureSingle) listPath(ctx context.Context, o *listPathOptions) (entries metaCacheEntriesSorted, err error) {
+	if err := checkListObjsArgs(ctx, o.Bucket, o.Prefix, o.Marker, es); err != nil {
+		return entries, err
+	}
+
+	// Marker is set validate pre-condition.
+	if o.Marker != "" && o.Prefix != "" {
+		// Marker not common with prefix is not implemented. Send an empty response
+		if !HasPrefix(o.Marker, o.Prefix) {
+			return entries, io.EOF
+		}
+	}
+
+	// With max keys of zero we have reached eof, return right here.
+	if o.Limit == 0 {
+		return entries, io.EOF
+	}
+
+	// For delimiter and prefix as '/' we do not list anything at all
+	// along // with the prefix. On a flat namespace with 'prefix'
+	// as '/' we don't have any entries, since all the keys are
+	// of form 'keyName/...'
+	if strings.HasPrefix(o.Prefix, SlashSeparator) {
+		return entries, io.EOF
+	}
+
+	// If delimiter is slashSeparator we must return directories of
+	// the non-recursive scan unless explicitly requested.
+	o.IncludeDirectories = o.Separator == slashSeparator
+	if (o.Separator == slashSeparator || o.Separator == "") && !o.Recursive {
+		o.Recursive = o.Separator != slashSeparator
+		o.Separator = slashSeparator
+	} else {
+		// Default is recursive, if delimiter is set then list non recursive.
+		o.Recursive = true
+	}
+
+	// Decode and get the optional list id from the marker.
+	o.parseMarker()
+	o.BaseDir = baseDirFromPrefix(o.Prefix)
+	o.Transient = o.Transient || isReservedOrInvalidBucket(o.Bucket, false)
+	o.SetFilter()
+	if o.Transient {
+		o.Create = false
+	}
+
+	// We have 2 cases:
+	// 1) Cold listing, just list.
+	// 2) Returning, but with no id. Start async listing.
+	// 3) Returning, with ID, stream from list.
+	//
+	// If we don't have a list id we must ask the server if it has a cache or create a new.
+	if o.ID != "" && !o.Transient {
+		// Create or ping with handout...
+		rpc := globalNotificationSys.restClientFromHash(pathJoin(o.Bucket, o.Prefix))
+		ctx, cancel := context.WithTimeout(ctx, 5*time.Second)
+		defer cancel()
+		var c *metacache
+		if rpc == nil {
+			resp := localMetacacheMgr.getBucket(ctx, o.Bucket).findCache(*o)
+			c = &resp
+		} else {
+			c, err = rpc.GetMetacacheListing(ctx, *o)
+		}
+		if err != nil {
+			if errors.Is(err, context.Canceled) {
+				// Context is canceled, return at once.
+				// request canceled, no entries to return
+				return entries, io.EOF
+			}
+			if !errors.Is(err, context.DeadlineExceeded) {
+				o.debugln("listPath: got error", err)
+			}
+			o.Transient = true
+			o.Create = false
+			o.ID = mustGetUUID()
+		} else {
+			if c.fileNotFound {
+				// No cache found, no entries found.
+				return entries, io.EOF
+			}
+			if c.status == scanStateError || c.status == scanStateNone {
+				o.ID = ""
+				o.Create = false
+				o.debugln("scan status", c.status, " - waiting a roundtrip to create")
+			} else {
+				// Continue listing
+				o.ID = c.id
+				go func(meta metacache) {
+					// Continuously update while we wait.
+					t := time.NewTicker(metacacheMaxClientWait / 10)
+					defer t.Stop()
+					select {
+					case <-ctx.Done():
+						// Request is done, stop updating.
+						return
+					case <-t.C:
+						meta.lastHandout = time.Now()
+						if rpc == nil {
+							meta, _ = localMetacacheMgr.updateCacheEntry(meta)
+						}
+						meta, _ = rpc.UpdateMetacacheListing(ctx, meta)
+					}
+				}(*c)
+			}
+		}
+
+		// We have an existing list ID, continue streaming.
+		if o.Create {
+			o.debugln("Creating", o)
+			entries, err = es.listAndSave(ctx, o)
+			if err == nil || err == io.EOF {
+				return entries, err
+			}
+			entries.truncate(0)
+		} else {
+			o.debugln("Resuming", o)
+			entries, err = es.streamMetadataParts(ctx, *o)
+			entries.reuse = true // We read from stream and are not sharing results.
+			if err == nil {
+				return entries, nil
+			}
+		}
+		if IsErr(err, []error{
+			nil,
+			context.Canceled,
+			context.DeadlineExceeded,
+			// io.EOF is expected and should be returned but no need to log it.
+			io.EOF,
+		}...) {
+			// Expected good errors we don't need to return error.
+			return entries, err
+		}
+		entries.truncate(0)
+		go func() {
+			rpc := globalNotificationSys.restClientFromHash(pathJoin(o.Bucket, o.Prefix))
+			if rpc != nil {
+				ctx, cancel := context.WithTimeout(GlobalContext, 5*time.Second)
+				defer cancel()
+				c, err := rpc.GetMetacacheListing(ctx, *o)
+				if err == nil {
+					c.error = "no longer used"
+					c.status = scanStateError
+					rpc.UpdateMetacacheListing(ctx, *c)
+				}
+			}
+		}()
+		o.ID = ""
+
+		if err != nil {
+			logger.LogIf(ctx, fmt.Errorf("Resuming listing from drives failed %w, proceeding to do raw listing", err))
+		}
+	}
+
+	// Do listing in-place.
+	// Create output for our results.
+	// Create filter for results.
+	o.debugln("Raw List", o)
+	filterCh := make(chan metaCacheEntry, o.Limit)
+	listCtx, cancelList := context.WithCancel(ctx)
+	filteredResults := o.gatherResults(listCtx, filterCh)
+	var wg sync.WaitGroup
+	wg.Add(1)
+	var listErr error
+
+	go func(o listPathOptions) {
+		defer wg.Done()
+		o.Limit = 0
+		listErr = es.listMerged(listCtx, o, filterCh)
+		o.debugln("listMerged returned with", listErr)
+	}(*o)
+
+	entries, err = filteredResults()
+	cancelList()
+	wg.Wait()
+	if listErr != nil && !errors.Is(listErr, context.Canceled) {
+		return entries, listErr
+	}
+	entries.reuse = true
+	truncated := entries.len() > o.Limit || err == nil
+	entries.truncate(o.Limit)
+	if !o.Transient && truncated {
+		if o.ID == "" {
+			entries.listID = mustGetUUID()
+		} else {
+			entries.listID = o.ID
+		}
+	}
+	if !truncated {
+		return entries, io.EOF
+	}
+	return entries, nil
+}
+
+// listMerged will list across all sets and return a merged results stream.
+// The result channel is closed when no more results are expected.
+func (es *erasureSingle) listMerged(ctx context.Context, o listPathOptions, results chan<- metaCacheEntry) error {
+	var mu sync.Mutex
+	var wg sync.WaitGroup
+	var listErr error
+	var inputs []chan metaCacheEntry
+
+	innerResults := make(chan metaCacheEntry, 100)
+	inputs = append(inputs, innerResults)
+
+	mu.Lock()
+	listCtx, cancelList := context.WithCancel(ctx)
+	defer cancelList()
+
+	wg.Add(1)
+	go func() {
+		defer wg.Done()
+		err := es.listPathInner(listCtx, o, innerResults)
+		mu.Lock()
+		defer mu.Unlock()
+		listErr = err
+	}()
+	mu.Unlock()
+
+	// Do lifecycle filtering.
+	if o.Lifecycle != nil {
+		filterIn := make(chan metaCacheEntry, 10)
+		go filterLifeCycle(ctx, o.Bucket, *o.Lifecycle, o.Retention, filterIn, results)
+		// Replace results.
+		results = filterIn
+	}
+
+	// Gather results to a single channel.
+	err := mergeEntryChannels(ctx, inputs, results, func(existing, other *metaCacheEntry) (replace bool) {
+		// Pick object over directory
+		if existing.isDir() && !other.isDir() {
+			return true
+		}
+		if !existing.isDir() && other.isDir() {
+			return false
+		}
+		eMeta, err := existing.xlmeta()
+		if err != nil {
+			return true
+		}
+		oMeta, err := other.xlmeta()
+		if err != nil {
+			return false
+		}
+		// Replace if modtime is newer
+		if !oMeta.latestModtime().Equal(oMeta.latestModtime()) {
+			return oMeta.latestModtime().After(eMeta.latestModtime())
+		}
+		// Use NumVersions as a final tiebreaker.
+		return len(oMeta.versions) > len(eMeta.versions)
+	})
+
+	cancelList()
+	wg.Wait()
+	if err != nil {
+		return err
+	}
+	if listErr != nil {
+		if contextCanceled(ctx) {
+			return nil
+		}
+		if listErr.Error() == io.EOF.Error() {
+			return nil
+		}
+		logger.LogIf(ctx, listErr)
+		return listErr
+	}
+	if contextCanceled(ctx) {
+		return ctx.Err()
+	}
+	return nil
+}
+
 // listMerged will list across all sets and return a merged results stream.
 // The result channel is closed when no more results are expected.
 func (z *erasureServerPools) listMerged(ctx context.Context, o listPathOptions, results chan<- metaCacheEntry) error {
@@ -395,6 +675,73 @@ func filterLifeCycle(ctx context.Context, bucket string, lc lifecycle.Lifecycle,
 	}
 }
 
+func (es *erasureSingle) listAndSave(ctx context.Context, o *listPathOptions) (entries metaCacheEntriesSorted, err error) {
+	// Use ID as the object name...
+	o.pool = 0
+	o.set = 0
+	saver := es
+
+	// Disconnect from call above, but cancel on exit.
+	listCtx, cancel := context.WithCancel(GlobalContext)
+	saveCh := make(chan metaCacheEntry, metacacheBlockSize)
+	inCh := make(chan metaCacheEntry, metacacheBlockSize)
+	outCh := make(chan metaCacheEntry, o.Limit)
+
+	filteredResults := o.gatherResults(ctx, outCh)
+
+	mc := o.newMetacache()
+	meta := metaCacheRPC{meta: &mc, cancel: cancel, rpc: globalNotificationSys.restClientFromHash(pathJoin(o.Bucket, o.Prefix)), o: *o}
+
+	// Save listing...
+	go func() {
+		if err := saver.saveMetaCacheStream(listCtx, &meta, saveCh); err != nil {
+			meta.setErr(err.Error())
+		}
+		cancel()
+	}()
+
+	// Do listing...
+	go func(o listPathOptions) {
+		err := es.listMerged(listCtx, o, inCh)
+		if err != nil {
+			meta.setErr(err.Error())
+		}
+		o.debugln("listAndSave: listing", o.ID, "finished with ", err)
+	}(*o)
+
+	// Keep track of when we return since we no longer have to send entries to output.
+	var funcReturned bool
+	var funcReturnedMu sync.Mutex
+	defer func() {
+		funcReturnedMu.Lock()
+		funcReturned = true
+		funcReturnedMu.Unlock()
+	}()
+	// Write listing to results and saver.
+	go func() {
+		var returned bool
+		for entry := range inCh {
+			if !returned {
+				funcReturnedMu.Lock()
+				returned = funcReturned
+				funcReturnedMu.Unlock()
+				outCh <- entry
+				if returned {
+					close(outCh)
+				}
+			}
+			entry.reusable = returned
+			saveCh <- entry
+		}
+		if !returned {
+			close(outCh)
+		}
+		close(saveCh)
+	}()
+
+	return filteredResults()
+}
+
 func (z *erasureServerPools) listAndSave(ctx context.Context, o *listPathOptions) (entries metaCacheEntriesSorted, err error) {
 	// Use ID as the object name...
 	o.pool = z.getAvailablePoolIdx(ctx, minioMetaBucket, o.ID, 10<<20)

cmd/metacache-set.go

@@ -543,6 +543,170 @@ func (er *erasureObjects) streamMetadataParts(ctx context.Context, o listPathOpt
 	}
 }
 
+func (es *erasureSingle) streamMetadataParts(ctx context.Context, o listPathOptions) (entries metaCacheEntriesSorted, err error) {
+	retries := 0
+	rpc := globalNotificationSys.restClientFromHash(pathJoin(o.Bucket, o.Prefix))
+
+	for {
+		if contextCanceled(ctx) {
+			return entries, ctx.Err()
+		}
+
+		// If many failures, check the cache state.
+		if retries > 10 {
+			err := o.checkMetacacheState(ctx, rpc)
+			if err != nil {
+				return entries, fmt.Errorf("remote listing canceled: %w", err)
+			}
+			retries = 1
+		}
+
+		const retryDelay = 250 * time.Millisecond
+		// All operations are performed without locks, so we must be careful and allow for failures.
+		// Read metadata associated with the object from a disk.
+		if retries > 0 {
+			_, err := es.disk.ReadVersion(ctx, minioMetaBucket,
+				o.objectPath(0), "", false)
+			if err != nil {
+				time.Sleep(retryDelay)
+				retries++
+				continue
+			}
+		}
+
+		// Load first part metadata...
+		// Read metadata associated with the object from all disks.
+		fi, metaArr, onlineDisks, err := es.getObjectFileInfo(ctx, minioMetaBucket, o.objectPath(0), ObjectOptions{}, true)
+		if err != nil {
+			switch toObjectErr(err, minioMetaBucket, o.objectPath(0)).(type) {
+			case ObjectNotFound:
+				retries++
+				time.Sleep(retryDelay)
+				continue
+			case InsufficientReadQuorum:
+				retries++
+				time.Sleep(retryDelay)
+				continue
+			default:
+				return entries, fmt.Errorf("reading first part metadata: %w", err)
+			}
+		}
+
+		partN, err := o.findFirstPart(fi)
+		switch {
+		case err == nil:
+		case errors.Is(err, io.ErrUnexpectedEOF):
+			if retries == 10 {
+				err := o.checkMetacacheState(ctx, rpc)
+				if err != nil {
+					return entries, fmt.Errorf("remote listing canceled: %w", err)
+				}
+				retries = -1
+			}
+			retries++
+			time.Sleep(retryDelay)
+			continue
+		case errors.Is(err, io.EOF):
+			return entries, io.EOF
+		}
+
+		// We got a stream to start at.
+		loadedPart := 0
+		for {
+			if contextCanceled(ctx) {
+				return entries, ctx.Err()
+			}
+
+			if partN != loadedPart {
+				if retries > 10 {
+					err := o.checkMetacacheState(ctx, rpc)
+					if err != nil {
+						return entries, fmt.Errorf("waiting for next part %d: %w", partN, err)
+					}
+					retries = 1
+				}
+
+				if retries > 0 {
+					// Load from one disk only
+					_, err := es.disk.ReadVersion(ctx, minioMetaBucket,
+						o.objectPath(partN), "", false)
+					if err != nil {
+						time.Sleep(retryDelay)
+						retries++
+						continue
+					}
+				}
+
+				// Load partN metadata...
+				fi, metaArr, onlineDisks, err = es.getObjectFileInfo(ctx, minioMetaBucket, o.objectPath(partN), ObjectOptions{}, true)
+				if err != nil {
+					time.Sleep(retryDelay)
+					retries++
+					continue
+				}
+				loadedPart = partN
+				bi, err := getMetacacheBlockInfo(fi, partN)
+				logger.LogIf(ctx, err)
+				if err == nil {
+					if bi.pastPrefix(o.Prefix) {
+						return entries, io.EOF
+					}
+				}
+			}
+
+			pr, pw := io.Pipe()
+			go func() {
+				werr := es.getObjectWithFileInfo(ctx, minioMetaBucket, o.objectPath(partN), 0,
+					fi.Size, pw, fi, metaArr, onlineDisks)
+				pw.CloseWithError(werr)
+			}()
+
+			tmp := newMetacacheReader(pr)
+			e, err := tmp.filter(o)
+			pr.CloseWithError(err)
+			entries.o = append(entries.o, e.o...)
+			if o.Limit > 0 && entries.len() > o.Limit {
+				entries.truncate(o.Limit)
+				return entries, nil
+			}
+			if err == nil {
+				// We stopped within the listing, we are done for now...
+				return entries, nil
+			}
+			if err != nil && err.Error() != io.EOF.Error() {
+				switch toObjectErr(err, minioMetaBucket, o.objectPath(partN)).(type) {
+				case ObjectNotFound:
+					retries++
+					time.Sleep(retryDelay)
+					continue
+				case InsufficientReadQuorum:
+					retries++
+					time.Sleep(retryDelay)
+					continue
+				default:
+					logger.LogIf(ctx, err)
+					return entries, err
+				}
+			}
+
+			// We finished at the end of the block.
+			// And should not expect any more results.
+			bi, err := getMetacacheBlockInfo(fi, partN)
+			logger.LogIf(ctx, err)
+			if err != nil || bi.EOS {
+				// We are done and there are no more parts.
+				return entries, io.EOF
+			}
+			if bi.endedPrefix(o.Prefix) {
+				// Nothing more for prefix.
+				return entries, io.EOF
+			}
+			partN++
+			retries = 0
+		}
+	}
+}
+
 // getListQuorum interprets list quorum values and returns appropriate
 // acceptable quorum expected for list operations
 func getListQuorum(quorum string, driveCount int) int {
@@ -562,6 +726,53 @@ func getListQuorum(quorum string, driveCount int) int {
 	return 3
 }
 
+// Will return io.EOF if continuing would not yield more results.
+func (es *erasureSingle) listPathInner(ctx context.Context, o listPathOptions, results chan<- metaCacheEntry) (err error) {
+	defer close(results)
+	o.debugf(color.Green("listPath:")+" with options: %#v", o)
+
+	// How to resolve results.
+	resolver := metadataResolutionParams{
+		dirQuorum: 1,
+		objQuorum: 1,
+		bucket:    o.Bucket,
+	}
+
+	// Maximum versions requested for "latest" object
+	// resolution on versioned buckets, this is to be only
+	// used when o.Versioned is false
+	if !o.Versioned {
+		resolver.requestedVersions = 1
+	}
+
+	ctxDone := ctx.Done()
+	return listPathRaw(ctx, listPathRawOptions{
+		disks:        []StorageAPI{es.disk},
+		bucket:       o.Bucket,
+		path:         o.BaseDir,
+		recursive:    o.Recursive,
+		filterPrefix: o.FilterPrefix,
+		minDisks:     1,
+		forwardTo:    o.Marker,
+		agreed: func(entry metaCacheEntry) {
+			select {
+			case <-ctxDone:
+			case results <- entry:
+			}
+		},
+		partial: func(entries metaCacheEntries, nAgreed int, errs []error) {
+			// Results Disagree :-(
+			entry, ok := entries.resolve(&resolver)
+			if ok {
+				select {
+				case <-ctxDone:
+				case results <- *entry:
+				}
+			}
+		},
+	})
+}
+
 // Will return io.EOF if continuing would not yield more results.
 func (er *erasureObjects) listPath(ctx context.Context, o listPathOptions, results chan<- metaCacheEntry) (err error) {
 	defer close(results)
@@ -654,6 +865,133 @@ func (m *metaCacheRPC) setErr(err string) {
 	*m.meta = meta
 }
 
+func (es *erasureSingle) saveMetaCacheStream(ctx context.Context, mc *metaCacheRPC, entries <-chan metaCacheEntry) (err error) {
+	o := mc.o
+	o.debugf(color.Green("saveMetaCacheStream:")+" with options: %#v", o)
+
+	metaMu := &mc.mu
+	rpc := mc.rpc
+	cancel := mc.cancel
+	defer func() {
+		o.debugln(color.Green("saveMetaCacheStream:")+"err:", err)
+		if err != nil && !errors.Is(err, io.EOF) {
+			go mc.setErr(err.Error())
+			cancel()
+		}
+	}()
+
+	defer cancel()
+	// Save continuous updates
+	go func() {
+		var err error
+		ticker := time.NewTicker(10 * time.Second)
+		defer ticker.Stop()
+		var exit bool
+		for !exit {
+			select {
+			case <-ticker.C:
+			case <-ctx.Done():
+				exit = true
+			}
+			metaMu.Lock()
+			meta := *mc.meta
+			meta, err = o.updateMetacacheListing(meta, rpc)
+			if err == nil && time.Since(meta.lastHandout) > metacacheMaxClientWait {
+				cancel()
+				exit = true
+				meta.status = scanStateError
+				meta.error = fmt.Sprintf("listing canceled since time since last handout was %v ago", time.Since(meta.lastHandout).Round(time.Second))
+				o.debugln(color.Green("saveMetaCacheStream: ") + meta.error)
+				meta, err = o.updateMetacacheListing(meta, rpc)
+			}
+			if err == nil {
+				*mc.meta = meta
+				if meta.status == scanStateError {
+					cancel()
+					exit = true
+				}
+			}
+			metaMu.Unlock()
+		}
+	}()
+
+	const retryDelay = 200 * time.Millisecond
+	const maxTries = 5
+
+	// Keep destination...
+	// Write results to disk.
+	bw := newMetacacheBlockWriter(entries, func(b *metacacheBlock) error {
+		// if the block is 0 bytes and its a first block skip it.
+		// skip only this for Transient caches.
+		if len(b.data) == 0 && b.n == 0 && o.Transient {
+			return nil
+		}
+		o.debugln(color.Green("saveMetaCacheStream:")+" saving block", b.n, "to", o.objectPath(b.n))
+		r, err := hash.NewReader(bytes.NewReader(b.data), int64(len(b.data)), "", "", int64(len(b.data)))
+		logger.LogIf(ctx, err)
+		custom := b.headerKV()
+		_, err = es.putMetacacheObject(ctx, o.objectPath(b.n), NewPutObjReader(r), ObjectOptions{
+			UserDefined: custom,
+		})
+		if err != nil {
+			mc.setErr(err.Error())
+			cancel()
+			return err
+		}
+		if b.n == 0 {
+			return nil
+		}
+		// Update block 0 metadata.
+		var retries int
+		for {
+			meta := b.headerKV()
+			fi := FileInfo{
+				Metadata: make(map[string]string, len(meta)),
+			}
+			for k, v := range meta {
+				fi.Metadata[k] = v
+			}
+			err := es.updateObjectMeta(ctx, minioMetaBucket, o.objectPath(0), fi, es.disk)
+			if err == nil {
+				break
+			}
+			switch err.(type) {
+			case ObjectNotFound:
+				return err
+			case StorageErr:
+				return err
+			case InsufficientReadQuorum:
+			default:
+				logger.LogIf(ctx, err)
+			}
+			if retries >= maxTries {
+				return err
+			}
+			retries++
+			time.Sleep(retryDelay)
+		}
+		return nil
+	})
+
+	// Blocks while consuming entries or an error occurs.
+	err = bw.Close()
+	if err != nil {
+		mc.setErr(err.Error())
+	}
+	metaMu.Lock()
+	defer metaMu.Unlock()
+	if mc.meta.error != "" {
+		return err
+	}
+	// Save success
+	mc.meta.status = scanStateSuccess
+	meta, err := o.updateMetacacheListing(*mc.meta, rpc)
+	if err == nil {
+		*mc.meta = meta
+	}
+	return nil
+}
+
 func (er *erasureObjects) saveMetaCacheStream(ctx context.Context, mc *metaCacheRPC, entries <-chan metaCacheEntry) (err error) {
 	o := mc.o
 	o.debugf(color.Green("saveMetaCacheStream:")+" with options: %#v", o)

cmd/metacache.go

@@ -155,9 +155,9 @@ func (m *metacache) delete(ctx context.Context) {
 		logger.LogIf(ctx, errors.New("metacache.delete: no object layer"))
 		return
 	}
-	ez, ok := objAPI.(*erasureServerPools)
+	ez, ok := objAPI.(renameAllStorager)
 	if !ok {
-		logger.LogIf(ctx, errors.New("metacache.delete: expected objAPI to be *erasureServerPools"))
+		logger.LogIf(ctx, errors.New("metacache.delete: expected objAPI to be 'renameAllStorager'"))
 		return
 	}
 	ez.renameAll(ctx, minioMetaBucket, metacachePrefixForID(m.bucket, m.id))

cmd/metrics-v2.go

@@ -1365,7 +1365,7 @@ func getMinioHealingMetrics() *MetricsGroup {
 	mg := &MetricsGroup{}
 	mg.RegisterRead(func(_ context.Context) (metrics []Metric) {
 		metrics = make([]Metric, 0, 5)
-		if !globalIsErasure {
+		if globalIsGateway {
 			return
 		}
 		bgSeq, exists := globalBackgroundHealState.getHealSequenceByToken(bgHealingUUID)
@@ -1817,7 +1817,7 @@ func getClusterStorageMetrics() *MetricsGroup {
 	mg.RegisterRead(func(ctx context.Context) (metrics []Metric) {
 		objLayer := newObjectLayerFn()
 		// Service not initialized yet
-		if objLayer == nil || !globalIsErasure {
+		if objLayer == nil || globalIsGateway {
 			return
 		}
 

cmd/metrics.go

@@ -132,7 +132,7 @@ func nodeHealthMetricsPrometheus(ch chan<- prometheus.Metric) {
 // collects healing specific metrics for MinIO instance in Prometheus specific format
 // and sends to given channel
 func healingMetricsPrometheus(ch chan<- prometheus.Metric) {
-	if !globalIsErasure {
+	if globalIsGateway {
 		return
 	}
 	bgSeq, exists := globalBackgroundHealState.getHealSequenceByToken(bgHealingUUID)

cmd/object-api-listobjects_test.go

@@ -35,9 +35,6 @@ func TestListObjectsVersionedFolders(t *testing.T) {
 }
 
 func testListObjectsVersionedFolders(obj ObjectLayer, instanceType string, t1 TestErrHandler) {
-	if instanceType == FSTestStr {
-		return
-	}
 	t, _ := t1.(*testing.T)
 	testBuckets := []string{
 		// This bucket is used for testing ListObject operations.
@@ -317,9 +314,6 @@ func testListObjects(obj ObjectLayer, instanceType string, t1 TestErrHandler) {
 }
 
 func _testListObjects(obj ObjectLayer, instanceType string, t1 TestErrHandler, versioned bool) {
-	if instanceType == FSTestStr && versioned {
-		return
-	}
 	t, _ := t1.(*testing.T)
 	testBuckets := []string{
 		// This bucket is used for testing ListObject operations.
@@ -1020,10 +1014,6 @@ func TestDeleteObjectVersionMarker(t *testing.T) {
 }
 
 func testDeleteObjectVersion(obj ObjectLayer, instanceType string, t1 TestErrHandler) {
-	if instanceType == FSTestStr {
-		return
-	}
-
 	t, _ := t1.(*testing.T)
 
 	testBuckets := []string{
@@ -1101,10 +1091,6 @@ func TestListObjectVersions(t *testing.T) {
 
 // Unit test for ListObjectVersions
 func testListObjectVersions(obj ObjectLayer, instanceType string, t1 TestErrHandler) {
-	if instanceType == FSTestStr {
-		return
-	}
-
 	t, _ := t1.(*testing.T)
 	testBuckets := []string{
 		// This bucket is used for testing ListObject operations.
@@ -1886,16 +1872,14 @@ func testListObjectsContinuation(obj ObjectLayer, instanceType string, t1 TestEr
 
 // Initialize FS backend for the benchmark.
 func initFSObjectsB(disk string, t *testing.B) (obj ObjectLayer) {
-	var err error
+	obj, _, err := initObjectLayer(context.Background(), mustGetPoolEndpoints(disk))
-	obj, err = NewFSObjectLayer(disk)
 	if err != nil {
-		t.Fatal("Unexpected err: ", err)
+		t.Fatal(err)
 	}
 
 	newTestConfig(globalMinioDefaultRegion, obj)
 
 	initAllSubsystems()
-
 	return obj
 }
 

cmd/object-api-multipart_test.go

@@ -1620,8 +1620,6 @@ func testListObjectParts(obj ObjectLayer, instanceType string, t TestErrHandler)
 				t.Errorf("Test %d: %s: Expected Bucket to be \"%s\", but instead found it to be \"%s\"", i+1, instanceType, expectedResult.Bucket, actualResult.Bucket)
 			}
 
-			// ListObjectParts returns empty response always in FS mode
-			if instanceType != FSTestStr {
 			// Asserting IsTruncated.
 			if actualResult.IsTruncated != testCase.expectedResult.IsTruncated {
 				t.Errorf("Test %d: %s: Expected IsTruncated to be \"%v\", but found it to \"%v\"", i+1, instanceType, expectedResult.IsTruncated, actualResult.IsTruncated)
@@ -1652,8 +1650,6 @@ func testListObjectParts(obj ObjectLayer, instanceType string, t TestErrHandler)
 					t.Errorf("Test %d: %s: Part %d: Expected Etag to be \"%s\", but instead found \"%s\"", i+1, instanceType, j+1, expectedResult.Parts[j].ETag, actualMetaData.ETag)
 				}
 			}
-
-			}
 		}
 	}
 }

cmd/object-api-utils.go

@@ -950,7 +950,7 @@ func compressSelfTest() {
 
 // getDiskInfos returns the disk information for the provided disks.
 // If a disk is nil or an error is returned the result will be nil as well.
-func getDiskInfos(ctx context.Context, disks []StorageAPI) []*DiskInfo {
+func getDiskInfos(ctx context.Context, disks ...StorageAPI) []*DiskInfo {
 	res := make([]*DiskInfo, len(disks))
 	for i, disk := range disks {
 		if disk == nil {

cmd/object-handlers_test.go

@@ -1954,7 +1954,7 @@ func testAPICopyObjectPartHandler(obj ObjectLayer, instanceType, bucketName stri
 			if err != nil {
 				t.Fatalf("Test %d: %s: Failed to look for copied object part: <ERROR> %s", i+1, instanceType, err)
 			}
-			if instanceType != FSTestStr && len(results.Parts) != 1 {
+			if len(results.Parts) != 1 {
 				t.Fatalf("Test %d: %s: Expected only one entry returned %d entries", i+1, instanceType, len(results.Parts))
 			}
 		}

cmd/prepare-storage.go

@@ -150,13 +150,13 @@ func connectLoadInitFormats(verboseLogging bool, firstDisk bool, endpoints Endpo
 
 	defer func(storageDisks []StorageAPI) {
 		if err != nil {
-			closeStorageDisks(storageDisks)
+			closeStorageDisks(storageDisks...)
 		}
 	}(storageDisks)
 
 	for i, err := range errs {
-		if err != nil {
+		if err != nil && !errors.Is(err, errXLBackend) {
-			if err == errDiskNotFound && verboseLogging {
+			if errors.Is(err, errDiskNotFound) && verboseLogging {
 				logger.Error("Unable to connect to %s: %v", endpoints[i], isServerResolvable(endpoints[i], time.Second))
 			} else {
 				logger.Error("Unable to use the drive %s: %v", endpoints[i], err)
@@ -173,7 +173,7 @@ func connectLoadInitFormats(verboseLogging bool, firstDisk bool, endpoints Endpo
 	// Check if we have
 	for i, sErr := range sErrs {
 		// print the error, nonetheless, which is perhaps unhandled
-		if sErr != errUnformattedDisk && sErr != errDiskNotFound && verboseLogging {
+		if !errors.Is(sErr, errUnformattedDisk) && !errors.Is(sErr, errDiskNotFound) && verboseLogging {
 			if sErr != nil {
 				logger.Error("Unable to read 'format.json' from %s: %v\n", endpoints[i], sErr)
 			}

cmd/server-main.go

@@ -222,6 +222,7 @@ func serverHandleCmdArgs(ctx *cli.Context) {
 	if globalIsDistErasure {
 		globalIsErasure = true
 	}
+	globalIsErasureSD = (setupType == ErasureSDSetupType)
 }
 
 func serverHandleEnvVars() {
@@ -232,13 +233,11 @@ func serverHandleEnvVars() {
 var globalHealStateLK sync.RWMutex
 
 func initAllSubsystems() {
-	if globalIsErasure {
 	globalHealStateLK.Lock()
 	// New global heal state
 	globalAllHealState = newHealState(true)
 	globalBackgroundHealState = newHealState(false)
 	globalHealStateLK.Unlock()
-	}
 
 	// Create new notification system and initialize notification peer targets
 	globalNotificationSys = NewNotificationSys(globalEndpoints)
@@ -527,11 +526,8 @@ func serverMain(ctx *cli.Context) {
 	xhttp.SetMinIOVersion(Version)
 
 	// Enable background operations for erasure coding
-	if globalIsErasure {
 	initAutoHeal(GlobalContext, newObject)
 	initHealMRF(GlobalContext, newObject)
-	}
-
 	initBackgroundExpiry(GlobalContext, newObject)
 
 	if globalActiveCred.Equal(auth.DefaultCredentials) {
@@ -579,7 +575,6 @@ func serverMain(ctx *cli.Context) {
 	// Background all other operations such as initializing bucket metadata etc.
 	go func() {
 		// Initialize transition tier configuration manager
-		if globalIsErasure {
 		initBackgroundReplication(GlobalContext, newObject)
 		initBackgroundTransition(GlobalContext, newObject)
 
@@ -593,7 +588,6 @@ func serverMain(ctx *cli.Context) {
 				logger.FatalIf(err, "Unable to initialize remote tier pending deletes journal")
 			}
 		}()
-		}
 
 		// Initialize site replication manager.
 		globalSiteReplicationSys.Init(GlobalContext, newObject)
@@ -664,7 +658,13 @@ func newObjectLayer(ctx context.Context, endpointServerPools EndpointServerPools
 	// For FS only, directly use the disk.
 	if endpointServerPools.NEndpoints() == 1 {
 		// Initialize new FS object layer.
-		return NewFSObjectLayer(endpointServerPools[0].Endpoints[0].Path)
+		newObject, err = NewFSObjectLayer(endpointServerPools[0].Endpoints[0].Path)
+		if err == nil {
+			return newObject, nil
+		}
+		if err != nil && err != errFreshDisk {
+			return newObject, err
+		}
 	}
 
 	return newErasureServerPools(ctx, endpointServerPools)

cmd/server-main_test.go

@@ -27,7 +27,7 @@ import (
 func TestNewObjectLayer(t *testing.T) {
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
-	// Tests for FS object layer.
+	// Tests for ErasureSD object layer.
 	nDisks := 1
 	disks, err := getRandomDisks(nDisks)
 	if err != nil {
@@ -39,7 +39,7 @@ func TestNewObjectLayer(t *testing.T) {
 	if err != nil {
 		t.Fatal("Unexpected object layer initialization error", err)
 	}
-	_, ok := obj.(*FSObjects)
+	_, ok := obj.(*erasureSingle)
 	if !ok {
 		t.Fatal("Unexpected object layer detected", reflect.TypeOf(obj))
 	}

cmd/server_test.go

@@ -39,7 +39,7 @@ import (
 	"github.com/minio/pkg/bucket/policy"
 )
 
-// API suite container common to both FS and Erasure.
+// API suite container common to both ErasureSD and Erasure.
 type TestSuiteCommon struct {
 	serverType string
 	testServer TestServer
@@ -122,12 +122,12 @@ func runAllTests(suite *TestSuiteCommon, c *check) {
 
 func TestServerSuite(t *testing.T) {
 	testCases := []*TestSuiteCommon{
-		// Init and run test on FS backend with signature v4.
+		// Init and run test on ErasureSD backend with signature v4.
-		{serverType: "FS", signer: signerV4},
+		{serverType: "ErasureSD", signer: signerV4},
-		// Init and run test on FS backend with signature v2.
+		// Init and run test on ErasureSD backend with signature v2.
-		{serverType: "FS", signer: signerV2},
+		{serverType: "ErasureSD", signer: signerV2},
-		// Init and run test on FS backend, with tls enabled.
+		// Init and run test on ErasureSD backend, with tls enabled.
-		{serverType: "FS", signer: signerV4, secure: true},
+		{serverType: "ErasureSD", signer: signerV4, secure: true},
 		// Init and run test on Erasure backend.
 		{serverType: "Erasure", signer: signerV4},
 		// Init and run test on ErasureSet backend.

cmd/setup-type.go

@@ -27,6 +27,9 @@ const (
 	// FSSetupType - FS setup type enum.
 	FSSetupType
 
+	// ErasureSDSetupType - Erasure single drive setup enum.
+	ErasureSDSetupType
+
 	// ErasureSetupType - Erasure setup type enum.
 	ErasureSetupType
 
@@ -41,6 +44,8 @@ func (setupType SetupType) String() string {
 	switch setupType {
 	case FSSetupType:
 		return globalMinioModeFS
+	case ErasureSDSetupType:
+		return globalMinioModeErasureSD
 	case ErasureSetupType:
 		return globalMinioModeErasure
 	case DistErasureSetupType:

cmd/storage-errors.go

@@ -116,6 +116,12 @@ var errDoneForNow = errors.New("done for now")
 // to proceed to next entry.
 var errSkipFile = errors.New("skip this file")
 
+// Returned by FS drive mode when a fresh disk is specified.
+var errFreshDisk = errors.New("FS backend requires existing disk")
+
+// errXLBackend XL drive mode requires fresh deployment.
+var errXLBackend = errors.New("XL backend requires fresh disk")
+
 // StorageErr represents error generated by xlStorage call.
 type StorageErr string
 

cmd/storage-rest-server.go

@@ -1140,6 +1140,10 @@ func checkDiskFatalErrs(errs []error) error {
 		return errFaultyDisk
 	}
 
+	if countErrs(errs, errXLBackend) == len(errs) {
+		return errXLBackend
+	}
+
 	return nil
 }
 
@@ -1152,6 +1156,8 @@ func checkDiskFatalErrs(errs []error) error {
 // Do not like it :-(
 func logFatalErrs(err error, endpoint Endpoint, exit bool) {
 	switch {
+	case errors.Is(err, errXLBackend):
+		logger.Fatal(config.ErrInvalidXLValue(err), "Unable to initialize backend")
 	case errors.Is(err, errUnsupportedDisk):
 		var hint string
 		if endpoint.URL != nil {

cmd/sts-handlers.go

@@ -389,7 +389,7 @@ func (sts *stsAPIHandlers) AssumeRoleWithSSO(w http.ResponseWriter, r *http.Requ
 			policyName = globalIAMSys.CurrentPolicies(policies)
 		}
 
-		if globalAuthZPlugin == nil {
+		if newGlobalAuthZPluginFn() == nil {
 			if !ok {
 				writeSTSErrorResponse(ctx, w, true, ErrSTSInvalidParameterValue,
 					fmt.Errorf("%s claim missing from the JWT token, credentials will not be generated", iamPolicyClaimNameOpenID()))
@@ -598,7 +598,7 @@ func (sts *stsAPIHandlers) AssumeRoleWithLDAPIdentity(w http.ResponseWriter, r *
 
 	// Check if this user or their groups have a policy applied.
 	ldapPolicies, _ := globalIAMSys.PolicyDBGet(ldapUserDN, false, groupDistNames...)
-	if len(ldapPolicies) == 0 && globalAuthZPlugin == nil {
+	if len(ldapPolicies) == 0 && newGlobalAuthZPluginFn() == nil {
 		writeSTSErrorResponse(ctx, w, true, ErrSTSInvalidParameterValue,
 			fmt.Errorf("expecting a policy to be set for user `%s` or one of their groups: `%s` - rejecting this request",
 				ldapUserDN, strings.Join(groupDistNames, "`,`")))

cmd/sts-handlers_test.go

@@ -42,10 +42,10 @@ func runAllIAMSTSTests(suite *TestSuiteIAM, c *check) {
 
 func TestIAMInternalIDPSTSServerSuite(t *testing.T) {
 	baseTestCases := []TestSuiteCommon{
-		// Init and run test on FS backend with signature v4.
+		// Init and run test on ErasureSD backend with signature v4.
-		{serverType: "FS", signer: signerV4},
+		{serverType: "ErasureSD", signer: signerV4},
-		// Init and run test on FS backend, with tls enabled.
+		// Init and run test on ErasureSD backend, with tls enabled.
-		{serverType: "FS", signer: signerV4, secure: true},
+		{serverType: "ErasureSD", signer: signerV4, secure: true},
 		// Init and run test on Erasure backend.
 		{serverType: "Erasure", signer: signerV4},
 		// Init and run test on ErasureSet backend.

cmd/test-utils_test.go

@@ -78,6 +78,8 @@ func TestMain(m *testing.M) {
 	// set to 'true' when testing is invoked
 	globalIsTesting = true
 
+	globalIsCICD = globalIsTesting
+
 	globalActiveCred = auth.Credentials{
 		AccessKey: auth.DefaultAccessKey,
 		SecretKey: auth.DefaultSecretKey,
@@ -191,10 +193,14 @@ func prepareFS() (ObjectLayer, string, error) {
 	if err != nil {
 		return nil, "", err
 	}
-	obj, err := NewFSObjectLayer(fsDirs[0])
+	obj, _, err := initObjectLayer(context.Background(), mustGetPoolEndpoints(fsDirs...))
 	if err != nil {
 		return nil, "", err
 	}
+
+	initAllSubsystems()
+
+	globalIAMSys.Init(context.Background(), obj, globalEtcdClient, 2*time.Second)
 	return obj, fsDirs[0], nil
 }
 
@@ -221,8 +227,7 @@ func prepareErasure16(ctx context.Context) (ObjectLayer, []string, error) {
 
 // Initialize FS objects.
 func initFSObjects(disk string, t *testing.T) (obj ObjectLayer) {
-	var err error
+	obj, _, err := initObjectLayer(context.Background(), mustGetPoolEndpoints(disk))
-	obj, err = NewFSObjectLayer(disk)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -242,8 +247,8 @@ type TestErrHandler interface {
 }
 
 const (
-	// FSTestStr is the string which is used as notation for Single node ObjectLayer in the unit tests.
+	// ErasureSDStr is the string which is used as notation for Single node ObjectLayer in the unit tests.
-	FSTestStr string = "FS"
+	ErasureSDStr string = "ErasureSD"
 
 	// ErasureTestStr is the string which is used as notation for Erasure ObjectLayer in the unit tests.
 	ErasureTestStr string = "Erasure"
@@ -1469,20 +1474,9 @@ func getRandomDisks(N int) ([]string, error) {
 
 // Initialize object layer with the supplied disks, objectLayer is nil upon any error.
 func newTestObjectLayer(ctx context.Context, endpointServerPools EndpointServerPools) (newObject ObjectLayer, err error) {
-	// For FS only, directly use the disk.
-	if endpointServerPools.NEndpoints() == 1 {
-		// Initialize new FS object layer.
-		return NewFSObjectLayer(endpointServerPools[0].Endpoints[0].Path)
-	}
-
-	z, err := newErasureServerPools(ctx, endpointServerPools)
-	if err != nil {
-		return nil, err
-	}
-
 	initAllSubsystems()
 
-	return z, nil
+	return newErasureServerPools(ctx, endpointServerPools)
 }
 
 // initObjectLayer - Instantiates object layer and returns it.
@@ -1750,7 +1744,7 @@ func ExecObjectLayerAPITest(t *testing.T, objAPITest objAPITestType, endpoints [
 	credentials := globalActiveCred
 
 	// Executing the object layer tests for single node setup.
-	objAPITest(objLayer, FSTestStr, bucketFS, fsAPIRouter, credentials, t)
+	objAPITest(objLayer, ErasureSDStr, bucketFS, fsAPIRouter, credentials, t)
 
 	objLayer, erasureDisks, err := prepareErasure16(ctx)
 	if err != nil {
@@ -1816,7 +1810,7 @@ func ExecObjectLayerTest(t TestErrHandler, objTest objTestType) {
 		globalIAMSys.Init(ctx, objLayer, globalEtcdClient, 2*time.Second)
 
 		// Executing the object layer tests for single node setup.
-		objTest(objLayer, FSTestStr, t)
+		objTest(objLayer, ErasureSDStr, t)
 
 		// Call clean up functions
 		cancel()

cmd/tier-handlers.go

@@ -74,7 +74,7 @@ func (api adminAPIHandlers) AddTierHandler(w http.ResponseWriter, r *http.Reques
 
 	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
 
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}
@@ -132,7 +132,7 @@ func (api adminAPIHandlers) ListTierHandler(w http.ResponseWriter, r *http.Reque
 
 	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
 
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}
@@ -158,7 +158,7 @@ func (api adminAPIHandlers) EditTierHandler(w http.ResponseWriter, r *http.Reque
 
 	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
 
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}
@@ -210,7 +210,7 @@ func (api adminAPIHandlers) RemoveTierHandler(w http.ResponseWriter, r *http.Req
 
 	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
 
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}
@@ -247,7 +247,7 @@ func (api adminAPIHandlers) VerifyTierHandler(w http.ResponseWriter, r *http.Req
 
 	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
 
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}
@@ -273,7 +273,7 @@ func (api adminAPIHandlers) TierStatsHandler(w http.ResponseWriter, r *http.Requ
 
 	defer logger.AuditLog(ctx, w, r, mustGetClaimsFromToken(r))
 
-	if !globalIsErasure {
+	if globalIsGateway {
 		writeErrorResponseJSON(ctx, w, errorCodes.ToAPIErr(ErrNotImplemented), r.URL)
 		return
 	}

cmd/utils.go

@@ -906,6 +906,8 @@ func getMinioMode() string {
 		mode = globalMinioModeErasure
 	} else if globalIsGateway {
 		mode = globalMinioModeGatewayPrefix + globalGatewayName
+	} else if globalIsErasureSD {
+		mode = globalMinioModeErasureSD
 	}
 	return mode
 }

cmd/xl-storage-format-utils.go

@@ -141,6 +141,9 @@ func getFileInfo(xlMetaBuf []byte, volume, path, versionID string, data bool) (F
 // Will return -1 for unknown values.
 func getXLDiskLoc(diskID string) (poolIdx, setIdx, diskIdx int) {
 	if api := newObjectLayerFn(); api != nil {
+		if globalIsErasureSD {
+			return 0, 0, 0
+		}
 		if ep, ok := api.(*erasureServerPools); ok {
 			if pool, set, disk, err := ep.getPoolAndSet(diskID); err == nil {
 				return pool, set, disk

cmd/xl-storage-format-v1.go

@@ -53,7 +53,7 @@ func isXLMetaFormatValid(version, format string) bool {
 // Verifies if the backend format metadata is sane by validating
 // the ErasureInfo, i.e. data and parity blocks.
 func isXLMetaErasureInfoValid(data, parity int) bool {
-	return ((data >= parity) && (data != 0) && (parity != 0))
+	return ((data >= parity) && (data > 0) && (parity >= 0))
 }
 
 //go:generate msgp -file=$GOFILE -unexported

cmd/xl-storage-format_test.go

@@ -62,13 +62,15 @@ func TestIsXLMetaErasureInfoValid(t *testing.T) {
 		{1, 5, 6, false},
 		{2, 5, 5, true},
 		{3, 0, 5, false},
-		{4, 5, 0, false},
+		{3, -1, 5, false},
-		{5, 5, 0, false},
+		{4, 5, -1, false},
-		{6, 5, 4, true},
+		{5, 5, 0, true},
+		{6, 5, 0, true},
+		{7, 5, 4, true},
 	}
 	for _, tt := range tests {
 		if got := isXLMetaErasureInfoValid(tt.data, tt.parity); got != tt.want {
-			t.Errorf("Test %d: Expected %v but received %v", tt.name, got, tt.want)
+			t.Errorf("Test %d: Expected %v but received %v -> %#v", tt.name, got, tt.want, tt)
 		}
 	}
 }

docs/config/README.md

@@ -309,7 +309,7 @@ Example: The following settings will increase the heal operation speed by allowi
 
 Once set the healer settings are automatically applied without the need for server restarts.
 
-> NOTE: Healing is not supported for gateway and single drive mode.
+> NOTE: Healing is not supported for Gateway deployments.
 
 ## Environment only settings (not in config)
 

docs/gateway/nas.md

@@ -1,5 +1,7 @@
 # MinIO NAS Gateway [![Slack](https://slack.min.io/slack?type=svg)](https://slack.min.io) 
 
+> NAS gateway is deprecated and will be removed in future, no more fresh deployments are supported.
+
 MinIO Gateway adds Amazon S3 compatibility to NAS storage. You may run multiple minio instances on the same shared NAS volume as a distributed object gateway.
 
 ## Support

internal/config/errors.go

@@ -19,6 +19,18 @@ package config
 
 // UI errors
 var (
+	ErrInvalidFSValue = newErrFn(
+		"Invalid drive path",
+		"Please provide an existing deployment with MinIO",
+		"MinIO does not support newer NAS gateway deployments anymore refer https://github.com/minio/minio/issues/14331",
+	)
+
+	ErrInvalidXLValue = newErrFn(
+		"Invalid drive path",
+		"Please provide a fresh drive for single drive MinIO setup",
+		"MinIO only supports fresh drive paths",
+	)
+
 	ErrInvalidBrowserValue = newErrFn(
 		"Invalid console value",
 		"Please check the passed value",