proactive deep heal object when a bitrot is detected (#9192)

cmd/admin-heal-ops.go

@@ -306,6 +306,12 @@ func (ahs *allHealState) PopHealStatusJSON(path string,
 	return jbytes, ErrNone
 }
 
+// healSource denotes single entity and heal option.
+type healSource struct {
+	path string           // entity path (format, buckets, objects) to heal
+	opts *madmin.HealOpts // optional heal option overrides default setting
+}
+
 // healSequence - state for each heal sequence initiated on the
 // server.
 type healSequence struct {
@@ -316,7 +322,7 @@ type healSequence struct {
 	path string
 
 	// List of entities (format, buckets, objects) to heal
-	sourceCh chan string
+	sourceCh chan healSource
 
 	// Report healing progress
 	reportProgress bool
@@ -629,11 +635,19 @@ func (h *healSequence) healSequenceStart() {
 	}
 }
 
-func (h *healSequence) queueHealTask(path string, healType madmin.HealItemType) error {
+func (h *healSequence) queueHealTask(source healSource, healType madmin.HealItemType) error {
 	var respCh = make(chan healResult)
 	defer close(respCh)
 	// Send heal request
-	globalBackgroundHealRoutine.queueHealTask(healTask{path: path, responseCh: respCh, opts: h.settings})
+	task := healTask{
+		path:       source.path,
+		responseCh: respCh,
+		opts:       h.settings,
+	}
+	if source.opts != nil {
+		task.opts = *source.opts
+	}
+	globalBackgroundHealRoutine.queueHealTask(task)
 	// Wait for answer and push result to the client
 	res := <-respCh
 	if !h.reportProgress {
@@ -679,20 +693,20 @@ func (h *healSequence) healItemsFromSourceCh() error {
 
 	for {
 		select {
-		case path := <-h.sourceCh:
+		case source := <-h.sourceCh:
 			var itemType madmin.HealItemType
 			switch {
-			case path == nopHeal:
+			case source.path == nopHeal:
 				continue
-			case path == SlashSeparator:
+			case source.path == SlashSeparator:
 				itemType = madmin.HealItemMetadata
-			case !strings.Contains(path, SlashSeparator):
+			case !strings.Contains(source.path, SlashSeparator):
 				itemType = madmin.HealItemBucket
 			default:
 				itemType = madmin.HealItemObject
 			}
 
-			if err := h.queueHealTask(path, itemType); err != nil {
+			if err := h.queueHealTask(source, itemType); err != nil {
 				logger.LogIf(h.ctx, err)
 			}
 
@@ -768,7 +782,7 @@ func (h *healSequence) healMinioSysMeta(metaPrefix string) func() error {
 				return errHealStopSignalled
 			}
 
-			herr := h.queueHealTask(pathJoin(bucket, object), madmin.HealItemBucketMetadata)
+			herr := h.queueHealTask(healSource{path: pathJoin(bucket, object)}, madmin.HealItemBucketMetadata)
 			// Object might have been deleted, by the time heal
 			// was attempted we ignore this object an move on.
 			if isErrObjectNotFound(herr) {
@@ -792,7 +806,7 @@ func (h *healSequence) healDiskFormat() error {
 		return errServerNotInitialized
 	}
 
-	return h.queueHealTask(SlashSeparator, madmin.HealItemMetadata)
+	return h.queueHealTask(healSource{path: SlashSeparator}, madmin.HealItemMetadata)
 }
 
 // healBuckets - check for all buckets heal or just particular bucket.
@@ -834,7 +848,7 @@ func (h *healSequence) healBucket(bucket string, bucketsOnly bool) error {
 		return errServerNotInitialized
 	}
 
-	if err := h.queueHealTask(bucket, madmin.HealItemBucket); err != nil {
+	if err := h.queueHealTask(healSource{path: bucket}, madmin.HealItemBucket); err != nil {
 		return err
 	}
 
@@ -875,5 +889,5 @@ func (h *healSequence) healObject(bucket, object string) error {
 		return errHealStopSignalled
 	}
 
-	return h.queueHealTask(pathJoin(bucket, object), madmin.HealItemObject)
+	return h.queueHealTask(healSource{path: pathJoin(bucket, object)}, madmin.HealItemObject)
 }

cmd/background-newdisks-heal-ops.go

@@ -77,10 +77,10 @@ func monitorLocalDisksAndHeal(ctx context.Context, objAPI ObjectLayer) {
 			}
 
 			// Reformat disks
-			bgSeq.sourceCh <- SlashSeparator
+			bgSeq.sourceCh <- healSource{path: SlashSeparator}
 
 			// Ensure that reformatting disks is finished
-			bgSeq.sourceCh <- nopHeal
+			bgSeq.sourceCh <- healSource{path: nopHeal}
 
 			var erasureSetInZoneToHeal = make([][]int, len(localDisksInZoneHeal))
 			// Compute the list of erasure set to heal

cmd/bitrot-streaming.go

@@ -27,6 +27,14 @@ import (
 	"github.com/minio/minio/cmd/logger"
 )
 
+type errHashMismatch struct {
+	message string
+}
+
+func (err *errHashMismatch) Error() string {
+	return err.message
+}
+
 // Calculates bitrot in chunks and writes the hash into the stream.
 type streamingBitrotWriter struct {
 	iow       *io.PipeWriter
@@ -132,8 +140,8 @@ func (b *streamingBitrotReader) ReadAt(buf []byte, offset int64) (int, error) {
 	b.h.Write(buf)
 
 	if !bytes.Equal(b.h.Sum(nil), b.hashBytes) {
-		err = fmt.Errorf("hashes do not match expected %s, got %s",
-			hex.EncodeToString(b.hashBytes), hex.EncodeToString(b.h.Sum(nil)))
+		err := &errHashMismatch{fmt.Sprintf("hashes do not match expected %s, got %s",
+			hex.EncodeToString(b.hashBytes), hex.EncodeToString(b.h.Sum(nil)))}
 		logger.LogIf(context.Background(), err)
 		return 0, err
 	}

cmd/erasure-decode.go

@@ -18,12 +18,16 @@ package cmd
 
 import (
 	"context"
+	"errors"
 	"io"
 	"sync"
+	"sync/atomic"
 
 	"github.com/minio/minio/cmd/logger"
 )
 
+var errHealRequired = errors.New("heal required")
+
 // Reads in parallel from readers.
 type parallelReader struct {
 	readers       []io.ReaderAt
@@ -72,6 +76,7 @@ func (p *parallelReader) Read() ([][]byte, error) {
 		readTriggerCh <- true
 	}
 
+	healRequired := int32(0) // Atomic bool flag.
 	readerIndex := 0
 	var wg sync.WaitGroup
 	// if readTrigger is true, it implies next disk.ReadAt() should be tried
@@ -109,6 +114,9 @@ func (p *parallelReader) Read() ([][]byte, error) {
 			p.buf[i] = p.buf[i][:p.shardSize]
 			_, err := disk.ReadAt(p.buf[i], p.offset)
 			if err != nil {
+				if _, ok := err.(*errHashMismatch); ok {
+					atomic.StoreInt32(&healRequired, 1)
+				}
 				p.readers[i] = nil
 				// Since ReadAt returned error, trigger another read.
 				readTriggerCh <- true
@@ -126,24 +134,49 @@ func (p *parallelReader) Read() ([][]byte, error) {
 
 	if p.canDecode(newBuf) {
 		p.offset += p.shardSize
+		if healRequired != 0 {
+			return newBuf, errHealRequired
+		}
 		return newBuf, nil
 	}
 
 	return nil, errXLReadQuorum
 }
 
+type errDecodeHealRequired struct {
+	err error
+}
+
+func (err *errDecodeHealRequired) Error() string {
+	return err.err.Error()
+}
+
+func (err *errDecodeHealRequired) Unwrap() error {
+	return err.err
+}
+
 // Decode reads from readers, reconstructs data if needed and writes the data to the writer.
 func (e Erasure) Decode(ctx context.Context, writer io.Writer, readers []io.ReaderAt, offset, length, totalLength int64) error {
+	healRequired, err := e.decode(ctx, writer, readers, offset, length, totalLength)
+	if healRequired {
+		return &errDecodeHealRequired{err}
+	}
+
+	return err
+}
+
+// Decode reads from readers, reconstructs data if needed and writes the data to the writer.
+func (e Erasure) decode(ctx context.Context, writer io.Writer, readers []io.ReaderAt, offset, length, totalLength int64) (bool, error) {
 	if offset < 0 || length < 0 {
 		logger.LogIf(ctx, errInvalidArgument)
-		return errInvalidArgument
+		return false, errInvalidArgument
 	}
 	if offset+length > totalLength {
 		logger.LogIf(ctx, errInvalidArgument)
-		return errInvalidArgument
+		return false, errInvalidArgument
 	}
 	if length == 0 {
-		return nil
+		return false, nil
 	}
 
 	reader := newParallelReader(readers, e, offset, totalLength)
@@ -151,6 +184,7 @@ func (e Erasure) Decode(ctx context.Context, writer io.Writer, readers []io.Read
 	startBlock := offset / e.blockSize
 	endBlock := (offset + length) / e.blockSize
 
+	var healRequired bool
 	var bytesWritten int64
 	for block := startBlock; block <= endBlock; block++ {
 		var blockOffset, blockLength int64
@@ -173,21 +207,26 @@ func (e Erasure) Decode(ctx context.Context, writer io.Writer, readers []io.Read
 		}
 		bufs, err := reader.Read()
 		if err != nil {
-			return err
+			if errors.Is(err, errHealRequired) {
+				healRequired = true
+			} else {
+				return healRequired, err
+			}
 		}
 		if err = e.DecodeDataBlocks(bufs); err != nil {
 			logger.LogIf(ctx, err)
-			return err
+			return healRequired, err
 		}
 		n, err := writeDataBlocks(ctx, writer, bufs, e.dataBlocks, blockOffset, blockLength)
 		if err != nil {
-			return err
+			return healRequired, err
 		}
 		bytesWritten += n
 	}
 	if bytesWritten != length {
 		logger.LogIf(ctx, errLessData)
-		return errLessData
+		return healRequired, errLessData
 	}
-	return nil
+
+	return healRequired, nil
 }

cmd/global-heal.go

@@ -47,7 +47,7 @@ func newBgHealSequence(numDisks int) *healSequence {
 	}
 
 	return &healSequence{
-		sourceCh:    make(chan string),
+		sourceCh:    make(chan healSource),
 		startTime:   UTCNow(),
 		clientToken: bgHealingUUID,
 		settings:    hs,
@@ -101,19 +101,34 @@ func healErasureSet(ctx context.Context, setIndex int, xlObj *xlObjects) error {
 	// Heal all buckets with all objects
 	for _, bucket := range buckets {
 		// Heal current bucket
-		bgSeq.sourceCh <- bucket.Name
+		bgSeq.sourceCh <- healSource{
+			path: bucket.Name,
+		}
 
 		// List all objects in the current bucket and heal them
 		listDir := listDirFactory(ctx, xlObj.getLoadBalancedDisks()...)
 		walkResultCh := startTreeWalk(ctx, bucket.Name, "", "", true, listDir, nil)
 		for walkEntry := range walkResultCh {
-			bgSeq.sourceCh <- pathJoin(bucket.Name, walkEntry.entry)
+			bgSeq.sourceCh <- healSource{
+				path: pathJoin(bucket.Name, walkEntry.entry),
+			}
 		}
 	}
 
 	return nil
 }
 
+// deepHealObject heals given object path in deep to fix bitrot.
+func deepHealObject(objectPath string) {
+	// Get background heal sequence to send elements to heal
+	bgSeq, _ := globalBackgroundHealState.getHealSequenceByToken(bgHealingUUID)
+
+	bgSeq.sourceCh <- healSource{
+		path: objectPath,
+		opts: &madmin.HealOpts{ScanMode: madmin.HealDeepScan},
+	}
+}
+
 // Returns the duration to the next background healing round
 func durationToNextHealRound(lastHeal time.Time) time.Duration {
 	if lastHeal.IsZero() {

cmd/xl-sets.go

@@ -1863,7 +1863,7 @@ func (s *xlSets) healMRFRoutine() {
 		for _, u := range mrfUploads {
 			// Send an object to be healed with a timeout
 			select {
-			case bgSeq.sourceCh <- u:
+			case bgSeq.sourceCh <- healSource{path: u}:
 			case <-time.After(100 * time.Millisecond):
 			}
 

cmd/xl-v1-object.go

@@ -295,7 +295,13 @@ func (xl xlObjects) getObject(ctx context.Context, bucket, object string, startO
 		// we return from this function.
 		closeBitrotReaders(readers)
 		if err != nil {
-			return toObjectErr(err, bucket, object)
+			if decodeHealErr, ok := err.(*errDecodeHealRequired); ok {
+				go deepHealObject(pathJoin(bucket, object))
+				err = decodeHealErr.err
+			}
+			if err != nil {
+				return toObjectErr(err, bucket, object)
+			}
 		}
 		for i, r := range readers {
 			if r == nil {