xl: Quit early when EC config is incorrect (#16390)

Co-authored-by: Anis Elleuch <anis@min.io>

cmd/erasure-server-pool.go

@@ -94,11 +94,14 @@ func newErasureServerPools(ctx context.Context, endpointServerPools EndpointServ
 		// -- Default for Standard Storage class is, parity = 3 - disks 6, 7
 		// -- Default for Standard Storage class is, parity = 4 - disks 8 to 16
 		if commonParityDrives == 0 {
-			commonParityDrives = ecDrivesNoConfig(ep.DrivesPerSet)
+			commonParityDrives, err = ecDrivesNoConfig(ep.DrivesPerSet)
+			if err != nil {
+				return nil, err
+			}
 		}
 
 		if err = storageclass.ValidateParity(commonParityDrives, ep.DrivesPerSet); err != nil {
-			return nil, fmt.Errorf("parity validation returned an error %w <- (%d, %d), for pool(%s)", err, commonParityDrives, ep.DrivesPerSet, humanize.Ordinal(i+1))
+			return nil, fmt.Errorf("parity validation returned an error: %w <- (%d, %d), for pool(%s)", err, commonParityDrives, ep.DrivesPerSet, humanize.Ordinal(i+1))
 		}
 
 		storageDisks[i], formats[i], err = waitForFormatErasure(local, ep.Endpoints, i+1,

cmd/erasure-sets.go

@@ -354,10 +354,6 @@ func newErasureSets(ctx context.Context, endpoints PoolEndpoints, storageDisks [
 		endpointStrings[i] = endpoint.String()
 	}
 
-	if defaultParityCount == 0 {
-		logger.Error("Warning: Default parity set to 0. This can lead to data loss.")
-	}
-
 	// Initialize the erasure sets instance.
 	s := &erasureSets{
 		sets:               make([]*erasureObjects, setCount),

cmd/erasure-sets_test.go

@@ -191,7 +191,12 @@ func TestNewErasureSets(t *testing.T) {
 	}
 
 	ep := PoolEndpoints{Endpoints: endpoints}
-	if _, err := newErasureSets(ctx, ep, storageDisks, format, ecDrivesNoConfig(16), 0); err != nil {
+
+	parity, err := ecDrivesNoConfig(16)
+	if err != nil {
+		t.Fatalf("Unexpected error during EC drive config: %v", err)
+	}
+	if _, err := newErasureSets(ctx, ep, storageDisks, format, parity, 0); err != nil {
 		t.Fatalf("Unable to initialize erasure")
 	}
 }

cmd/format-erasure.go

@@ -741,7 +741,10 @@ func fixFormatErasureV3(storageDisks []StorageAPI, endpoints Endpoints, formats
 func initFormatErasure(ctx context.Context, storageDisks []StorageAPI, setCount, setDriveCount int, deploymentID, distributionAlgo string, sErrs []error) (*formatErasureV3, error) {
 	format := newFormatErasureV3(setCount, setDriveCount)
 	formats := make([]*formatErasureV3, len(storageDisks))
-	wantAtMost := ecDrivesNoConfig(setDriveCount)
+	wantAtMost, err := ecDrivesNoConfig(setDriveCount)
+	if err != nil {
+		return nil, err
+	}
 
 	for i := 0; i < setCount; i++ {
 		hostCount := make(map[string]int, setDriveCount)
@@ -795,13 +798,12 @@ func initFormatErasure(ctx context.Context, storageDisks []StorageAPI, setCount,
 
 // ecDrivesNoConfig returns the erasure coded drives in a set if no config has been set.
 // It will attempt to read it from env variable and fall back to drives/2.
-func ecDrivesNoConfig(setDriveCount int) int {
-	sc, _ := storageclass.LookupConfig(config.KVS{}, setDriveCount)
-	ecDrives := sc.GetParityForSC(storageclass.STANDARD)
-	if ecDrives < 0 {
-		ecDrives = storageclass.DefaultParityBlocks(setDriveCount)
+func ecDrivesNoConfig(setDriveCount int) (int, error) {
+	sc, err := storageclass.LookupConfig(config.KVS{}, setDriveCount)
+	if err != nil {
+		return 0, err
 	}
-	return ecDrives
+	return sc.GetParityForSC(storageclass.STANDARD), nil
 }
 
 // Make Erasure backend meta volumes.

cmd/server-main.go

@@ -722,6 +722,11 @@ func serverMain(ctx *cli.Context) {
 
 		// Prints the formatted startup message, if err is not nil then it prints additional information as well.
 		printStartupMessage(getAPIEndpoints(), err)
+
+		// Print a warning at the end of the startup banner so it is more noticeable
+		if globalStorageClass.GetParityForSC("") == 0 {
+			logger.Error("Warning: The standard parity is set to 0. This can lead to data loss.")
+		}
 	}()
 
 	region := globalSite.Region

internal/config/storageclass/storage-class.go

@@ -304,12 +304,7 @@ func LookupConfig(kvs config.KVS, setDriveCount int) (cfg Config, err error) {
 	// Validation is done after parsing both the storage classes. This is needed because we need one
 	// storage class value to deduce the correct value of the other storage class.
 	if err = validateParity(cfg.Standard.Parity, cfg.RRS.Parity, setDriveCount); err != nil {
-		cfg.RRS.Parity = defaultRRSParity
-		if setDriveCount == 1 {
-			cfg.RRS.Parity = 0
-		}
-		cfg.Standard.Parity = DefaultParityBlocks(setDriveCount)
-		return cfg, err
+		return Config{}, err
 	}
 
 	return cfg, nil