fix: make sure to avoid calling RenameData() on disconnected disks. (#14094)

Large clusters with multiple sets, or multi-pool setups at times might
fail and report unexpected "file not found" errors. This can become
a problem during startup sequence when some files need to be created
at multiple locations.

- This PR ensures that we nil the erasure writers such that they
  are skipped in RenameData() call.

- RenameData() doesn't need to "Access()" calls for `.minio.sys`
  folders they always exist.

- Make sure PutObject() never returns ObjectNotFound{} for any
  errors, make sure it always returns "WriteQuorum" when renameData()
  fails with ObjectNotFound{}. Return appropriate errors for all
  other cases.

cmd/bitrot.go

@@ -119,8 +119,10 @@ func newBitrotReader(disk StorageAPI, data []byte, bucket string, filePath strin
 // Close all the readers.
 func closeBitrotReaders(rs []io.ReaderAt) {
 	for _, r := range rs {
-		if br, ok := r.(io.Closer); ok {
-			br.Close()
+		if r != nil {
+			if br, ok := r.(io.Closer); ok {
+				br.Close()
+			}
 		}
 	}
 }
@@ -128,8 +130,10 @@ func closeBitrotReaders(rs []io.ReaderAt) {
 // Close all the writers.
 func closeBitrotWriters(ws []io.Writer) {
 	for _, w := range ws {
-		if bw, ok := w.(io.Closer); ok {
-			bw.Close()
+		if w != nil {
+			if bw, ok := w.(io.Closer); ok {
+				bw.Close()
+			}
 		}
 	}
 }

cmd/erasure-decode.go

@@ -322,8 +322,8 @@ func (e Erasure) Heal(ctx context.Context, writers []io.Writer, readers []io.Rea
 			errs:        make([]error, len(writers)),
 		}
 
-		err = w.Write(ctx, bufs)
-		if err != nil {
+		if err = w.Write(ctx, bufs); err != nil {
+			logger.LogIf(ctx, err)
 			return err
 		}
 	}

cmd/erasure-encode.go

@@ -52,7 +52,10 @@ func (p *parallelWriter) Write(ctx context.Context, blocks [][]byte) error {
 			if p.errs[i] == nil {
 				if n != len(blocks[i]) {
 					p.errs[i] = io.ErrShortWrite
+					p.writers[i] = nil
 				}
+			} else {
+				p.writers[i] = nil
 			}
 		}(i)
 	}
@@ -93,6 +96,7 @@ func (e *Erasure) Encode(ctx context.Context, src io.Reader, writers []io.Writer
 		blocks, err = e.EncodeData(ctx, buf[:n])
 		if err != nil {
 			logger.LogIf(ctx, err)
+
 			return 0, err
 		}
 

cmd/erasure-healing.go

@@ -540,7 +540,7 @@ func (er erasureObjects) healObject(ctx context.Context, bucket string, object s
 
 			// If all disks are having errors, we give up.
 			if disksToHealCount == 0 {
-				return result, fmt.Errorf("all disks had write errors, unable to heal")
+				return result, fmt.Errorf("all disks had write errors, unable to heal %s/%s", bucket, object)
 			}
 
 		}

cmd/erasure-object.go

@@ -701,9 +701,10 @@ func (er erasureObjects) putMetacacheObject(ctx context.Context, key string, r *
 		if disk == nil {
 			continue
 		}
-
-		inlineBuffers[i] = bytes.NewBuffer(make([]byte, 0, shardFileSize))
-		writers[i] = newStreamingBitrotWriterBuffer(inlineBuffers[i], DefaultBitrotAlgorithm, erasure.ShardSize())
+		if disk.IsOnline() {
+			inlineBuffers[i] = bytes.NewBuffer(make([]byte, 0, shardFileSize))
+			writers[i] = newStreamingBitrotWriterBuffer(inlineBuffers[i], DefaultBitrotAlgorithm, erasure.ShardSize())
+		}
 	}
 
 	n, erasureErr := erasure.Encode(ctx, data, writers, buffer, writeQuorum)
@@ -720,6 +721,7 @@ func (er erasureObjects) putMetacacheObject(ctx context.Context, key string, r *
 
 	for i, w := range writers {
 		if w == nil {
+			// Make sure to avoid writing to disks which we couldn't complete in erasure.Encode()
 			onlineDisks[i] = nil
 			continue
 		}
@@ -930,6 +932,10 @@ func (er erasureObjects) putObject(ctx context.Context, bucket string, object st
 			continue
 		}
 
+		if !disk.IsOnline() {
+			continue
+		}
+
 		if len(inlineBuffers) > 0 {
 			sz := shardFileSize
 			if sz < 0 {
@@ -939,6 +945,7 @@ func (er erasureObjects) putObject(ctx context.Context, bucket string, object st
 			writers[i] = newStreamingBitrotWriterBuffer(inlineBuffers[i], DefaultBitrotAlgorithm, erasure.ShardSize())
 			continue
 		}
+
 		writers[i] = newBitrotWriter(disk, minioMetaTmpBucket, tempErasureObj, shardFileSize, DefaultBitrotAlgorithm, erasure.ShardSize())
 	}
 
@@ -1012,6 +1019,9 @@ func (er erasureObjects) putObject(ctx context.Context, bucket string, object st
 
 	// Rename the successfully written temporary object to final location.
 	if onlineDisks, err = renameData(ctx, onlineDisks, minioMetaTmpBucket, tempObj, partsMetadata, bucket, object, writeQuorum); err != nil {
+		if errors.Is(err, errFileNotFound) {
+			return ObjectInfo{}, toObjectErr(errErasureWriteQuorum, bucket, object)
+		}
 		logger.LogIf(ctx, err)
 		return ObjectInfo{}, toObjectErr(err, bucket, object)
 	}

cmd/server-main.go

@@ -291,6 +291,7 @@ func configRetriableErrors(err error) bool {
 		errors.Is(err, io.ErrUnexpectedEOF) ||
 		errors.As(err, &rquorum) ||
 		errors.As(err, &wquorum) ||
+		isErrObjectNotFound(err) ||
 		isErrBucketNotFound(err) ||
 		errors.Is(err, os.ErrDeadlineExceeded)
 }

cmd/xl-storage.go

@@ -1984,6 +1984,14 @@ func (s *xlStorage) Delete(ctx context.Context, volume string, path string, recu
 	return s.deleteFile(volumeDir, filePath, recursive)
 }
 
+func skipAccessChecks(volume string) bool {
+	switch volume {
+	case minioMetaTmpBucket, minioMetaBucket, minioMetaMultipartBucket:
+		return true
+	}
+	return false
+}
+
 // RenameData - rename source path to destination path atomically, metadata and data directory.
 func (s *xlStorage) RenameData(ctx context.Context, srcVolume, srcPath string, fi FileInfo, dstVolume, dstPath string) (err error) {
 	defer func() {
@@ -2010,23 +2018,27 @@ func (s *xlStorage) RenameData(ctx context.Context, srcVolume, srcPath string, f
 		return err
 	}
 
-	// Stat a volume entry.
-	if err = Access(srcVolumeDir); err != nil {
-		if osIsNotExist(err) {
-			return errVolumeNotFound
-		} else if isSysErrIO(err) {
-			return errFaultyDisk
+	if !skipAccessChecks(srcVolume) {
+		// Stat a volume entry.
+		if err = Access(srcVolumeDir); err != nil {
+			if osIsNotExist(err) {
+				return errVolumeNotFound
+			} else if isSysErrIO(err) {
+				return errFaultyDisk
+			}
+			return err
 		}
-		return err
 	}
 
-	if err = Access(dstVolumeDir); err != nil {
-		if osIsNotExist(err) {
-			return errVolumeNotFound
-		} else if isSysErrIO(err) {
-			return errFaultyDisk
+	if !skipAccessChecks(dstVolume) {
+		if err = Access(dstVolumeDir); err != nil {
+			if osIsNotExist(err) {
+				return errVolumeNotFound
+			} else if isSysErrIO(err) {
+				return errFaultyDisk
+			}
+			return err
 		}
-		return err
 	}
 
 	srcFilePath := pathutil.Join(srcVolumeDir, pathJoin(srcPath, xlStorageFormatFile))
@@ -2237,7 +2249,8 @@ func (s *xlStorage) RenameData(ctx context.Context, srcVolume, srcPath string, f
 					s.deleteFile(dstVolumeDir, legacyDataPath, true)
 				}
 				s.deleteFile(dstVolumeDir, dstDataPath, false)
-				if err != errFileNotFound {
+				// Looks like srcFilePath is missing usually at .minio.sys/ ignore it.
+				if !errors.Is(err, errFileNotFound) {
 					logger.LogIf(ctx, err)
 				}
 				return osErrToFileErr(err)
@@ -2252,9 +2265,11 @@ func (s *xlStorage) RenameData(ctx context.Context, srcVolume, srcPath string, f
 			}
 			s.deleteFile(dstVolumeDir, dstFilePath, false)
 
-			if err != errFileNotFound {
+			// Looks like srcFilePath is missing usually at .minio.sys/ ignore it.
+			if !errors.Is(err, errFileNotFound) {
 				logger.LogIf(ctx, err)
 			}
+
 			return osErrToFileErr(err)
 		}