fix: return context error from context reader (#9507)

cmd/bucket-handlers.go

@@ -628,7 +628,7 @@ func (api objectAPIHandlers) PostPolicyBucketHandler(w http.ResponseWriter, r *h
 	bucket := mux.Vars(r)["bucket"]
 
 	// To detect if the client has disconnected.
-	r.Body = &detectDisconnect{r.Body, r.Context().Done()}
+	r.Body = &contextReader{r.Body, r.Context()}
 
 	// Require Content-Length to be set in the request
 	size := r.ContentLength

cmd/object-api-errors.go

@@ -17,6 +17,7 @@
 package cmd
 
 import (
+	"context"
 	"errors"
 	"fmt"
 	"io"
@@ -106,6 +107,8 @@ func toObjectErr(err error, params ...string) error {
 		err = InsufficientWriteQuorum{}
 	case io.ErrUnexpectedEOF, io.ErrShortWrite:
 		err = IncompleteBody{}
+	case context.Canceled, context.DeadlineExceeded:
+		err = IncompleteBody{}
 	}
 	return err
 }

cmd/object-api-utils.go

@@ -18,6 +18,7 @@ package cmd
 
 import (
 	"bytes"
+	"context"
 	"encoding/hex"
 	"fmt"
 	"io"
@@ -842,16 +843,17 @@ func newS2CompressReader(r io.Reader) io.ReadCloser {
 	return pr
 }
 
-// Returns error if the cancelCh has been closed (indicating that S3 client has disconnected)
+// Returns error if the context is canceled, indicating
-type detectDisconnect struct {
+// either client has disconnected
+type contextReader struct {
 	io.ReadCloser
-	cancelCh <-chan struct{}
+	ctx context.Context
 }
 
-func (d *detectDisconnect) Read(p []byte) (int, error) {
+func (d *contextReader) Read(p []byte) (int, error) {
 	select {
-	case <-d.cancelCh:
+	case <-d.ctx.Done():
-		return 0, io.ErrUnexpectedEOF
+		return 0, d.ctx.Err()
 	default:
 		return d.ReadCloser.Read(p)
 	}

cmd/object-handlers.go

@@ -1209,7 +1209,7 @@ func (api objectAPIHandlers) PutObjectHandler(w http.ResponseWriter, r *http.Req
 	}
 
 	// To detect if the client has disconnected.
-	r.Body = &detectDisconnect{r.Body, r.Context().Done()}
+	r.Body = &contextReader{r.Body, r.Context()}
 
 	// X-Amz-Copy-Source shouldn't be set for this call.
 	if _, ok := r.Header[xhttp.AmzCopySource]; ok {
@@ -1958,7 +1958,7 @@ func (api objectAPIHandlers) PutObjectPartHandler(w http.ResponseWriter, r *http
 	}
 
 	// To detect if the client has disconnected.
-	r.Body = &detectDisconnect{r.Body, r.Context().Done()}
+	r.Body = &contextReader{r.Body, r.Context()}
 
 	// X-Amz-Copy-Source shouldn't be set for this call.
 	if _, ok := r.Header[xhttp.AmzCopySource]; ok {