filestore, s3store: Handle errors when closing files

Fixes #698

pkg/filestore/filestore.go

@@ -160,12 +160,17 @@ func (upload *fileUpload) WriteChunk(ctx context.Context, offset int64, src io.R
 	if err != nil {
 		return 0, err
 	}
-	defer file.Close()
+	// Avoid the use of defer file.Close() here to ensure no errors are lost
+	// See https://github.com/tus/tusd/issues/698.
 
 	n, err := io.Copy(file, src)
-
 	upload.info.Offset += n
-	return n, err
+	if err != nil {
+		file.Close()
+		return n, err
+	}
+
+	return n, file.Close()
 }
 
 func (upload *fileUpload) GetReader(ctx context.Context) (io.ReadCloser, error) {
@@ -187,7 +192,14 @@ func (upload *fileUpload) ConcatUploads(ctx context.Context, uploads []handler.U
 	if err != nil {
 		return err
 	}
-	defer file.Close()
+	defer func() {
+		// Ensure that close error is propagated, if it occurs.
+		// See https://github.com/tus/tusd/issues/698.
+		cerr := file.Close()
+		if err == nil {
+			err = cerr
+		}
+	}()
 
 	for _, partialUpload := range uploads {
 		fileUpload := partialUpload.(*fileUpload)

pkg/s3store/s3store.go

@@ -500,10 +500,9 @@ func (upload *s3Upload) uploadParts(ctx context.Context, offset int64, src io.Re
 			upload.parts = append(upload.parts, part)
 
 			wg.Add(1)
-			go func(file io.ReadSeeker, part *s3Part, closePart func()) {
+			go func(file io.ReadSeeker, part *s3Part, closePart func() error) {
 				defer upload.store.releaseUploadSemaphore()
 				defer wg.Done()
-				defer closePart()
 
 				t := time.Now()
 				uploadPartInput := &s3.UploadPartInput{
@@ -519,17 +518,22 @@ func (upload *s3Upload) uploadParts(ctx context.Context, offset int64, src io.Re
 				} else {
 					part.etag = etag
 				}
+				if cerr := closePart(); cerr != nil && uploadErr == nil {
+					uploadErr = cerr
+				}
 			}(partfile, part, closePart)
 		} else {
 			wg.Add(1)
-			go func(file io.ReadSeeker, closePart func()) {
+			go func(file io.ReadSeeker, closePart func() error) {
 				defer upload.store.releaseUploadSemaphore()
 				defer wg.Done()
-				defer closePart()
 
 				if err := store.putIncompletePartForUpload(ctx, uploadId, file); err != nil {
 					uploadErr = err
 				}
+				if cerr := closePart(); cerr != nil && uploadErr == nil {
+					uploadErr = cerr
+				}
 				upload.incompletePartSize = partsize
 			}(partfile, closePart)
 		}

pkg/s3store/s3store_part_producer.go

@@ -24,7 +24,7 @@ type s3PartProducer struct {
 
 type fileChunk struct {
 	reader      io.ReadSeeker
-	closeReader func()
+	closeReader func() error
 	size        int64
 }
 
@@ -116,9 +116,11 @@ func (spp *s3PartProducer) nextPart(size int64) (fileChunk, bool, error) {
 
 		return fileChunk{
 			reader: file,
-			closeReader: func() {
-				file.Close()
-				os.Remove(file.Name())
+			closeReader: func() error {
+				if err := file.Close(); err != nil {
+					return err
+				}
+				return os.Remove(file.Name())
 			},
 			size: n,
 		}, true, nil
@@ -148,7 +150,7 @@ func (spp *s3PartProducer) nextPart(size int64) (fileChunk, bool, error) {
 		return fileChunk{
 			// buf does not get written to anymore, so we can turn it into a reader
 			reader:      bytes.NewReader(buf.Bytes()),
-			closeReader: func() {},
+			closeReader: func() error { return nil },
 			size:        n,
 		}, true, nil
 	}