fix: http range request return status 500 (#5251)

When volume server unavailable for at least one chunk; was returning status 206.

Split `StreamContent` in two parts,
- first prepare, to get chunk info and return stream function
- then write chunk, with that stream function

That allow to catch error in first step before setting response status code in `processRangeRequest`

weed/filer/stream.go

@@ -3,13 +3,14 @@ package filer
 import (
 	"bytes"
 	"fmt"
-	"golang.org/x/exp/slices"
 	"io"
 	"math"
 	"strings"
 	"sync"
 	"time"
 
+	"golang.org/x/exp/slices"
+
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/pb/filer_pb"
 	"github.com/seaweedfs/seaweedfs/weed/stats"
@@ -66,13 +67,14 @@ func NewFileReader(filerClient filer_pb.FilerClient, entry *filer_pb.Entry) io.R
 	return NewChunkStreamReader(filerClient, entry.GetChunks())
 }
 
-func StreamContent(masterClient wdclient.HasLookupFileIdFunction, writer io.Writer, chunks []*filer_pb.FileChunk, offset int64, size int64) error {
-	return StreamContentWithThrottler(masterClient, writer, chunks, offset, size, 0)
-}
+type DoStreamContent func(writer io.Writer) error
 
-func StreamContentWithThrottler(masterClient wdclient.HasLookupFileIdFunction, writer io.Writer, chunks []*filer_pb.FileChunk, offset int64, size int64, downloadMaxBytesPs int64) error {
+func PrepareStreamContent(masterClient wdclient.HasLookupFileIdFunction, chunks []*filer_pb.FileChunk, offset int64, size int64) (DoStreamContent, error) {
+	return PrepareStreamContentWithThrottler(masterClient, chunks, offset, size, 0)
+}
 
-	glog.V(4).Infof("start to stream content for chunks: %d", len(chunks))
+func PrepareStreamContentWithThrottler(masterClient wdclient.HasLookupFileIdFunction, chunks []*filer_pb.FileChunk, offset int64, size int64, downloadMaxBytesPs int64) (DoStreamContent, error) {
+	glog.V(4).Infof("prepare to stream content for chunks: %d", len(chunks))
 	chunkViews := ViewFromChunks(masterClient.GetLookupFileIdFunction(), chunks, offset, size)
 
 	fileId2Url := make(map[string][]string)
@@ -91,15 +93,16 @@ func StreamContentWithThrottler(masterClient wdclient.HasLookupFileIdFunction, w
 		}
 		if err != nil {
 			glog.V(1).Infof("operation LookupFileId %s failed, err: %v", chunkView.FileId, err)
-			return err
+			return nil, err
 		} else if len(urlStrings) == 0 {
 			errUrlNotFound := fmt.Errorf("operation LookupFileId %s failed, err: urls not found", chunkView.FileId)
 			glog.Error(errUrlNotFound)
-			return errUrlNotFound
+			return nil, errUrlNotFound
 		}
 		fileId2Url[chunkView.FileId] = urlStrings
 	}
 
+	return func(writer io.Writer) error {
 		downloadThrottler := util.NewWriteThrottler(downloadMaxBytesPs)
 		remaining := size
 		for x := chunkViews.Front(); x != nil; x = x.Next {
@@ -136,7 +139,15 @@ func StreamContentWithThrottler(masterClient wdclient.HasLookupFileIdFunction, w
 		}
 
 		return nil
+	}, nil
+}
 
+func StreamContent(masterClient wdclient.HasLookupFileIdFunction, writer io.Writer, chunks []*filer_pb.FileChunk, offset int64, size int64) error {
+	streamFn, err := PrepareStreamContent(masterClient, chunks, offset, size)
+	if err != nil {
+		return err
+	}
+	return streamFn(writer)
 }
 
 // ----------------  ReadAllReader ----------------------------------

weed/server/common.go

@@ -6,7 +6,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"github.com/seaweedfs/seaweedfs/weed/s3api/s3_constants"
 	"io"
 	"io/fs"
 	"mime/multipart"
@@ -18,6 +17,9 @@ import (
 	"sync"
 	"time"
 
+	"github.com/seaweedfs/seaweedfs/weed/filer"
+	"github.com/seaweedfs/seaweedfs/weed/s3api/s3_constants"
+
 	"google.golang.org/grpc"
 
 	"github.com/seaweedfs/seaweedfs/weed/glog"
@@ -282,7 +284,7 @@ func adjustHeaderContentDisposition(w http.ResponseWriter, r *http.Request, file
 	}
 }
 
-func processRangeRequest(r *http.Request, w http.ResponseWriter, totalSize int64, mimeType string, writeFn func(writer io.Writer, offset int64, size int64) error) error {
+func processRangeRequest(r *http.Request, w http.ResponseWriter, totalSize int64, mimeType string, prepareWriteFn func(offset int64, size int64) (filer.DoStreamContent, error)) error {
 	rangeReq := r.Header.Get("Range")
 	bufferedWriter := writePool.Get().(*bufio.Writer)
 	bufferedWriter.Reset(w)
@@ -293,7 +295,13 @@ func processRangeRequest(r *http.Request, w http.ResponseWriter, totalSize int64
 
 	if rangeReq == "" {
 		w.Header().Set("Content-Length", strconv.FormatInt(totalSize, 10))
-		if err := writeFn(bufferedWriter, 0, totalSize); err != nil {
+		writeFn, err := prepareWriteFn(0, totalSize)
+		if err != nil {
+			glog.Errorf("processRangeRequest: %v", err)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return fmt.Errorf("processRangeRequest: %v", err)
+		}
+		if err = writeFn(bufferedWriter); err != nil {
 			glog.Errorf("processRangeRequest: %v", err)
 			http.Error(w, err.Error(), http.StatusInternalServerError)
 			return fmt.Errorf("processRangeRequest: %v", err)
@@ -335,8 +343,14 @@ func processRangeRequest(r *http.Request, w http.ResponseWriter, totalSize int64
 		w.Header().Set("Content-Length", strconv.FormatInt(ra.length, 10))
 		w.Header().Set("Content-Range", ra.contentRange(totalSize))
 
+		writeFn, err := prepareWriteFn(ra.start, ra.length)
+		if err != nil {
+			glog.Errorf("processRangeRequest range[0]: %+v err: %v", w.Header(), err)
+			http.Error(w, err.Error(), http.StatusInternalServerError)
+			return fmt.Errorf("processRangeRequest: %v", err)
+		}
 		w.WriteHeader(http.StatusPartialContent)
-		err = writeFn(bufferedWriter, ra.start, ra.length)
+		err = writeFn(bufferedWriter)
 		if err != nil {
 			glog.Errorf("processRangeRequest range[0]: %+v err: %v", w.Header(), err)
 			http.Error(w, err.Error(), http.StatusInternalServerError)
@@ -346,11 +360,20 @@ func processRangeRequest(r *http.Request, w http.ResponseWriter, totalSize int64
 	}
 
 	// process multiple ranges
-	for _, ra := range ranges {
+	writeFnByRange := make(map[int](func(writer io.Writer) error))
+
+	for i, ra := range ranges {
 		if ra.start > totalSize {
 			http.Error(w, "Out of Range", http.StatusRequestedRangeNotSatisfiable)
 			return fmt.Errorf("out of range: %v", err)
 		}
+		writeFn, err := prepareWriteFn(ra.start, ra.length)
+		if err != nil {
+			glog.Errorf("processRangeRequest range[%d] err: %v", i, err)
+			http.Error(w, "Internal Error", http.StatusInternalServerError)
+			return fmt.Errorf("processRangeRequest range[%d] err: %v", i, err)
+		}
+		writeFnByRange[i] = writeFn
 	}
 	sendSize := rangesMIMESize(ranges, mimeType, totalSize)
 	pr, pw := io.Pipe()
@@ -359,13 +382,18 @@ func processRangeRequest(r *http.Request, w http.ResponseWriter, totalSize int64
 	sendContent := pr
 	defer pr.Close() // cause writing goroutine to fail and exit if CopyN doesn't finish.
 	go func() {
-		for _, ra := range ranges {
+		for i, ra := range ranges {
 			part, e := mw.CreatePart(ra.mimeHeader(mimeType, totalSize))
 			if e != nil {
 				pw.CloseWithError(e)
 				return
 			}
-			if e = writeFn(part, ra.start, ra.length); e != nil {
+			writeFn := writeFnByRange[i]
+			if writeFn == nil {
+				pw.CloseWithError(e)
+				return
+			}
+			if e = writeFn(part); e != nil {
 				pw.CloseWithError(e)
 				return
 			}

weed/server/filer_server_handlers_read.go

@@ -231,14 +231,16 @@ func (fs *FilerServer) GetOrHeadHandler(w http.ResponseWriter, r *http.Request)
 		}
 	}
 
-	processRangeRequest(r, w, totalSize, mimeType, func(writer io.Writer, offset int64, size int64) error {
+	processRangeRequest(r, w, totalSize, mimeType, func(offset int64, size int64) (filer.DoStreamContent, error) {
 		if offset+size <= int64(len(entry.Content)) {
+			return func(writer io.Writer) error {
 				_, err := writer.Write(entry.Content[offset : offset+size])
 				if err != nil {
 					stats.FilerHandlerCounter.WithLabelValues(stats.ErrorWriteEntry).Inc()
 					glog.Errorf("failed to write entry content: %v", err)
 				}
 				return err
+			}, nil
 		}
 		chunks := entry.GetChunks()
 		if entry.IsInRemoteOnly() {
@@ -249,17 +251,25 @@ func (fs *FilerServer) GetOrHeadHandler(w http.ResponseWriter, r *http.Request)
 			}); err != nil {
 				stats.FilerHandlerCounter.WithLabelValues(stats.ErrorReadCache).Inc()
 				glog.Errorf("CacheRemoteObjectToLocalCluster %s: %v", entry.FullPath, err)
-				return fmt.Errorf("cache %s: %v", entry.FullPath, err)
+				return nil, fmt.Errorf("cache %s: %v", entry.FullPath, err)
 			} else {
 				chunks = resp.Entry.GetChunks()
 			}
 		}
 
-		err = filer.StreamContentWithThrottler(fs.filer.MasterClient, writer, chunks, offset, size, fs.option.DownloadMaxBytesPs)
+		streamFn, err := filer.PrepareStreamContentWithThrottler(fs.filer.MasterClient, chunks, offset, size, fs.option.DownloadMaxBytesPs)
+		if err != nil {
+			stats.FilerHandlerCounter.WithLabelValues(stats.ErrorReadStream).Inc()
+			glog.Errorf("failed to prepare stream content %s: %v", r.URL, err)
+			return nil, err
+		}
+		return func(writer io.Writer) error {
+			err := streamFn(writer)
 			if err != nil {
 				stats.FilerHandlerCounter.WithLabelValues(stats.ErrorReadStream).Inc()
 				glog.Errorf("failed to stream content %s: %v", r.URL, err)
 			}
 			return err
+		}, nil
 	})
 }

weed/server/volume_server_handlers_read.go

@@ -15,6 +15,7 @@ import (
 	"sync/atomic"
 	"time"
 
+	"github.com/seaweedfs/seaweedfs/weed/filer"
 	"github.com/seaweedfs/seaweedfs/weed/storage/types"
 	"github.com/seaweedfs/seaweedfs/weed/util/mem"
 
@@ -382,12 +383,14 @@ func writeResponseContent(filename, mimeType string, rs io.ReadSeeker, w http.Re
 		return nil
 	}
 
-	return processRangeRequest(r, w, totalSize, mimeType, func(writer io.Writer, offset int64, size int64) error {
+	return processRangeRequest(r, w, totalSize, mimeType, func(offset int64, size int64) (filer.DoStreamContent, error) {
+		return func(writer io.Writer) error {
 			if _, e = rs.Seek(offset, 0); e != nil {
 				return e
 			}
 			_, e = io.CopyN(writer, rs, size)
 			return e
+		}, nil
 	})
 }
 
@@ -409,8 +412,10 @@ func (vs *VolumeServer) streamWriteResponseContent(filename string, mimeType str
 		return
 	}
 
-	processRangeRequest(r, w, totalSize, mimeType, func(writer io.Writer, offset int64, size int64) error {
+	processRangeRequest(r, w, totalSize, mimeType, func(offset int64, size int64) (filer.DoStreamContent, error) {
+		return func(writer io.Writer) error {
 			return vs.store.ReadVolumeNeedleDataInto(volumeId, n, readOption, writer, offset, size)
+		}, nil
 	})
 
 }