fix possible crashes on deleteMarker replication (#11308)

Delete marker can have `metaSys` set to nil, that
can lead to crashes after the delete marker has
been healed.

Additionally also fix isObjectDangling check
for transitioned objects, that do not have parts
should be treated similar to Delete marker.

cmd/erasure-healing.go

@@ -25,6 +25,7 @@ import (
 	"time"
 
 	"github.com/minio/minio/cmd/logger"
+	"github.com/minio/minio/pkg/bucket/lifecycle"
 	"github.com/minio/minio/pkg/madmin"
 	"github.com/minio/minio/pkg/sync/errgroup"
 )
@@ -226,8 +227,6 @@ func (er erasureObjects) healObject(ctx context.Context, bucket string, object s
 	dryRun := opts.DryRun
 	scanMode := opts.ScanMode
 
-	dataBlocks := lfi.Erasure.DataBlocks
-
 	storageDisks := er.getDisks()
 	storageEndpoints := er.getEndpoints()
 
@@ -244,8 +243,8 @@ func (er erasureObjects) healObject(ctx context.Context, bucket string, object s
 		Bucket:       bucket,
 		Object:       object,
 		DiskCount:    len(storageDisks),
-		ParityBlocks: len(storageDisks) / 2,
-		DataBlocks:   len(storageDisks) / 2,
+		ParityBlocks: er.defaultParityCount,
+		DataBlocks:   len(storageDisks) - er.defaultParityCount,
 	}
 
 	// Loop to find number of disks with valid data, per-drive
@@ -316,7 +315,7 @@ func (er erasureObjects) healObject(ctx context.Context, bucket string, object s
 
 	// If less than read quorum number of disks have all the parts
 	// of the data, we can't reconstruct the erasure-coded data.
-	if numAvailableDisks < dataBlocks {
+	if numAvailableDisks < result.DataBlocks {
 		return er.purgeObjectDangling(ctx, bucket, object, versionID, partsMetadata, errs, dataErrs, opts)
 	}
 
@@ -333,7 +332,7 @@ func (er erasureObjects) healObject(ctx context.Context, bucket string, object s
 
 	// Latest FileInfo for reference. If a valid metadata is not
 	// present, it is as good as object not found.
-	latestMeta, err := pickValidFileInfo(ctx, partsMetadata, modTime, dataBlocks)
+	latestMeta, err := pickValidFileInfo(ctx, partsMetadata, modTime, result.DataBlocks)
 	if err != nil {
 		return result, toObjectErr(err, bucket, object, versionID)
 	}
@@ -363,7 +362,7 @@ func (er erasureObjects) healObject(ctx context.Context, bucket string, object s
 		dataDir = migrateDataDir
 	}
 
-	if !latestMeta.Deleted {
+	if !latestMeta.Deleted || latestMeta.TransitionStatus != lifecycle.TransitionComplete {
 		result.DataBlocks = latestMeta.Erasure.DataBlocks
 		result.ParityBlocks = latestMeta.Erasure.ParityBlocks
 
@@ -775,8 +774,10 @@ func isObjectDangling(metaArr []FileInfo, errs []error, dataErrs []error) (valid
 		break
 	}
 
-	if validMeta.Deleted {
-		// notFoundParts is ignored since a delete marker does not have any parts
+	if validMeta.Deleted || validMeta.TransitionStatus == lifecycle.TransitionComplete {
+		// notFoundParts is ignored since a
+		// - delete marker does not have any parts
+		// - transition status of complete has no parts
 		return validMeta, corruptedErasureMeta+notFoundErasureMeta > len(errs)/2
 	}
 

cmd/xl-storage-format-v1.go

@@ -182,10 +182,6 @@ func (m *xlMetaV1Object) ToFileInfo(volume, path string) (FileInfo, error) {
 	if !m.valid() {
 		return FileInfo{}, errFileCorrupt
 	}
-	var transitionStatus string
-	if st, ok := m.Meta[ReservedMetadataPrefixLower+"transition-status"]; ok {
-		transitionStatus = st
-	}
 	fi := FileInfo{
 		Volume:    volume,
 		Name:      path,
@@ -197,8 +193,8 @@ func (m *xlMetaV1Object) ToFileInfo(volume, path string) (FileInfo, error) {
 		VersionID: m.VersionID,
 		DataDir:   m.DataDir,
 	}
-	if transitionStatus != "" {
-		fi.TransitionStatus = transitionStatus
+	if st, ok := m.Meta[ReservedMetadataPrefixLower+"transition-status"]; ok {
+		fi.TransitionStatus = st
 	}
 	return fi, nil
 }

cmd/xl-storage-format-v2.go

@@ -260,6 +260,7 @@ func (z *xlMetaV2) AddVersion(fi FileInfo) error {
 		ventry.DeleteMarker = &xlMetaV2DeleteMarker{
 			VersionID: uv,
 			ModTime:   fi.ModTime.UnixNano(),
+			MetaSys:   make(map[string][]byte),
 		}
 	} else {
 		ventry.Type = ObjectType
@@ -355,13 +356,19 @@ func (j xlMetaV2DeleteMarker) ToFileInfo(volume, path string) (FileInfo, error)
 		versionID = uuid.UUID(j.VersionID).String()
 	}
 	fi := FileInfo{
-		Volume:                        volume,
-		Name:                          path,
-		ModTime:                       time.Unix(0, j.ModTime).UTC(),
-		VersionID:                     versionID,
-		Deleted:                       true,
-		DeleteMarkerReplicationStatus: string(j.MetaSys[xhttp.AmzBucketReplicationStatus]),
-		VersionPurgeStatus:            VersionPurgeStatusType(string(j.MetaSys[VersionPurgeStatusKey])),
+		Volume:    volume,
+		Name:      path,
+		ModTime:   time.Unix(0, j.ModTime).UTC(),
+		VersionID: versionID,
+		Deleted:   true,
+	}
+	for k, v := range j.MetaSys {
+		if strings.EqualFold(k, xhttp.AmzBucketReplicationStatus) {
+			fi.DeleteMarkerReplicationStatus = string(v)
+		}
+		if strings.EqualFold(k, VersionPurgeStatusKey) {
+			fi.VersionPurgeStatus = VersionPurgeStatusType(string(v))
+		}
 	}
 	return fi, nil
 }
@@ -408,12 +415,15 @@ func (j xlMetaV2Object) ToFileInfo(volume, path string) (FileInfo, error) {
 		fi.Metadata[k] = v
 	}
 	for k, v := range j.MetaSys {
-		if strings.HasPrefix(strings.ToLower(k), ReservedMetadataPrefixLower) {
-			fi.Metadata[k] = string(v)
+		if strings.EqualFold(strings.ToLower(k), ReservedMetadataPrefixLower+"transition-status") {
+			fi.TransitionStatus = string(v)
 		}
 		if strings.EqualFold(k, VersionPurgeStatusKey) {
 			fi.VersionPurgeStatus = VersionPurgeStatusType(string(v))
 		}
+		if strings.HasPrefix(strings.ToLower(k), ReservedMetadataPrefixLower) {
+			fi.Metadata[k] = string(v)
+		}
 	}
 	fi.Erasure.Algorithm = j.ErasureAlgorithm.String()
 	fi.Erasure.Index = j.ErasureIndex
@@ -426,9 +436,6 @@ func (j xlMetaV2Object) ToFileInfo(volume, path string) (FileInfo, error) {
 	}
 	fi.DataDir = uuid.UUID(j.DataDir).String()
 
-	if st, ok := j.MetaSys[ReservedMetadataPrefixLower+"transition-status"]; ok {
-		fi.TransitionStatus = string(st)
-	}
 	return fi, nil
 }
 

cmd/xl-storage.go

@@ -962,7 +962,7 @@ func (s *xlStorage) DeleteVersion(ctx context.Context, volume, path string, fi F
 	}
 
 	// when data-dir is specified. Transition leverages existing DeleteObject
-	// api call to mark object as deleted.When object is pending transition,
+	// api call to mark object as deleted. When object is pending transition,
 	// just update the metadata and avoid deleting data dir.
 	if dataDir != "" && fi.TransitionStatus != lifecycle.TransitionPending {
 		filePath := pathJoin(volumeDir, path, dataDir)
@@ -974,6 +974,7 @@ func (s *xlStorage) DeleteVersion(ctx context.Context, volume, path string, fi F
 			return err
 		}
 	}
+
 	// transitioned objects maintains metadata on the source cluster. When transition
 	// status is set, update the metadata to disk.
 	if !lastVersion || fi.TransitionStatus != "" {