validate storage class across pools when setting config (#11320)

```
mc admin config set alias/ storage_class standard=EC:3
```

should only succeed if parity ratio is valid for all
server pools, if not we should fail proactively.

This PR also needs to bring other changes now that
we need to cater for variadic drive counts per pool.

Bonus fixes also various bugs reproduced with

- GetObjectWithPartNumber()
- CopyObjectPartWithOffsets()
- CopyObjectWithMetadata()
- PutObjectPart,PutObject with truncated streams

cmd/object-handlers_test.go

@@ -944,7 +944,12 @@ func testAPIGetObjectWithPartNumberHandler(obj ObjectLayer, instanceType, bucket
 		}
 
 		rs := partNumberToRangeSpec(oinfo, partNumber)
-		off, length, err := rs.GetOffsetLength(oinfo.Size)
+		size, err := oinfo.GetActualSize()
+		if err != nil {
+			t.Fatalf("Object: %s Object Index %d: Unexpected err: %v", object, oindex, err)
+		}
+
+		off, length, err := rs.GetOffsetLength(size)
 		if err != nil {
 			t.Fatalf("Object: %s Object Index %d: Unexpected err: %v", object, oindex, err)
 		}
@@ -955,6 +960,7 @@ func testAPIGetObjectWithPartNumberHandler(obj ObjectLayer, instanceType, bucket
 			readers = append(readers, NewDummyDataGen(p, cumulativeSum))
 			cumulativeSum += p
 		}
+
 		refReader := io.LimitReader(ioutilx.NewSkipReader(io.MultiReader(readers...), off), length)
 		if ok, msg := cmpReaders(refReader, rec.Body); !ok {
 			t.Fatalf("(%s) Object: %s ObjectIndex %d PartNumber: %d --> data mismatch! (msg: %s)", instanceType, oi.objectName, oindex, partNumber, msg)
@@ -1247,8 +1253,8 @@ func testAPIPutObjectStreamSigV4Handler(obj ObjectLayer, instanceType, bucketNam
 		apiRouter.ServeHTTP(rec, req)
 		// Assert the response code with the expected status.
 		if rec.Code != testCase.expectedRespStatus {
-			t.Errorf("Test %d %s: Expected the response status to be `%d`, but instead found `%d`",
-				i+1, instanceType, testCase.expectedRespStatus, rec.Code)
+			t.Errorf("Test %d %s: Expected the response status to be `%d`, but instead found `%d`: fault case %d",
+				i+1, instanceType, testCase.expectedRespStatus, rec.Code, testCase.fault)
 		}
 		// read the response body.
 		actualContent, err := ioutil.ReadAll(rec.Body)
@@ -1274,14 +1280,18 @@ func testAPIPutObjectStreamSigV4Handler(obj ObjectLayer, instanceType, bucketNam
 				t.Fatalf("Test %d: %s: ContentEncoding is set to \"%s\" which is unexpected, expected \"%s\"", i+1, instanceType, objInfo.ContentEncoding, expectedContentEncoding)
 			}
 			buffer := new(bytes.Buffer)
-			err = obj.GetObject(context.Background(), testCase.bucketName, testCase.objectName, 0, int64(testCase.dataLen), buffer, objInfo.ETag, opts)
+			r, err := obj.GetObjectNInfo(context.Background(), testCase.bucketName, testCase.objectName, nil, nil, readLock, opts)
 			if err != nil {
 				t.Fatalf("Test %d: %s: Failed to fetch the copied object: <ERROR> %s", i+1, instanceType, err)
 			}
+			if _, err = io.Copy(buffer, r); err != nil {
+				r.Close()
+				t.Fatalf("Test %d: %s: Failed to fetch the copied object: <ERROR> %s", i+1, instanceType, err)
+			}
+			r.Close()
 			if !bytes.Equal(testCase.data, buffer.Bytes()) {
 				t.Errorf("Test %d: %s: Data Mismatch: Data fetched back from the uploaded object doesn't match the original one.", i+1, instanceType)
 			}
-			buffer.Reset()
 		}
 	}
 }
@@ -1445,12 +1455,16 @@ func testAPIPutObjectHandler(obj ObjectLayer, instanceType, bucketName string, a
 		}
 		if testCase.expectedRespStatus == http.StatusOK {
 			buffer := new(bytes.Buffer)
-
 			// Fetch the object to check whether the content is same as the one uploaded via PutObject.
-			err = obj.GetObject(context.Background(), testCase.bucketName, testCase.objectName, 0, int64(len(bytesData)), buffer, "", opts)
+			gr, err := obj.GetObjectNInfo(context.Background(), testCase.bucketName, testCase.objectName, nil, nil, readLock, opts)
 			if err != nil {
 				t.Fatalf("Test %d: %s: Failed to fetch the copied object: <ERROR> %s", i+1, instanceType, err)
 			}
+			if _, err = io.Copy(buffer, gr); err != nil {
+				gr.Close()
+				t.Fatalf("Test %d: %s: Failed to fetch the copied object: <ERROR> %s", i+1, instanceType, err)
+			}
+			gr.Close()
 			if !bytes.Equal(bytesData, buffer.Bytes()) {
 				t.Errorf("Test %d: %s: Data Mismatch: Data fetched back from the uploaded object doesn't match the original one.", i+1, instanceType)
 			}
@@ -1490,10 +1504,15 @@ func testAPIPutObjectHandler(obj ObjectLayer, instanceType, bucketName string, a
 		if testCase.expectedRespStatus == http.StatusOK {
 			buffer := new(bytes.Buffer)
 			// Fetch the object to check whether the content is same as the one uploaded via PutObject.
-			err = obj.GetObject(context.Background(), testCase.bucketName, testCase.objectName, 0, int64(len(bytesData)), buffer, "", opts)
+			gr, err := obj.GetObjectNInfo(context.Background(), testCase.bucketName, testCase.objectName, nil, nil, readLock, opts)
 			if err != nil {
 				t.Fatalf("Test %d: %s: Failed to fetch the copied object: <ERROR> %s", i+1, instanceType, err)
 			}
+			if _, err = io.Copy(buffer, gr); err != nil {
+				gr.Close()
+				t.Fatalf("Test %d: %s: Failed to fetch the copied object: <ERROR> %s", i+1, instanceType, err)
+			}
+			gr.Close()
 			if !bytes.Equal(bytesData, buffer.Bytes()) {
 				t.Errorf("Test %d: %s: Data Mismatch: Data fetched back from the uploaded object doesn't match the original one.", i+1, instanceType)
 			}
@@ -1638,9 +1657,15 @@ func testAPICopyObjectPartHandlerSanity(obj ObjectLayer, instanceType, bucketNam
 	}
 
 	var buf bytes.Buffer
-	if err = obj.GetObject(context.Background(), bucketName, testObject, 0, int64(len(bytesData[0].byteData)), &buf, "", opts); err != nil {
+	r, err := obj.GetObjectNInfo(context.Background(), bucketName, testObject, nil, nil, readLock, ObjectOptions{})
+	if err != nil {
 		t.Fatalf("Test: %s reading completed file failed: <ERROR> %v", instanceType, err)
 	}
+	if _, err = io.Copy(&buf, r); err != nil {
+		r.Close()
+		t.Fatalf("Test %s: Failed to fetch the copied object: <ERROR> %s", instanceType, err)
+	}
+	r.Close()
 	if !bytes.Equal(buf.Bytes(), bytesData[0].byteData) {
 		t.Fatalf("Test: %s returned data is not expected corruption detected:", instanceType)
 	}
@@ -2035,6 +2060,7 @@ func testAPICopyObjectHandler(obj ObjectLayer, instanceType, bucketName string,
 		copySourceHeader     string // data for "X-Amz-Copy-Source" header. Contains the object to be copied in the URL.
 		copyModifiedHeader   string // data for "X-Amz-Copy-Source-If-Modified-Since" header
 		copyUnmodifiedHeader string // data for "X-Amz-Copy-Source-If-Unmodified-Since" header
+		copySourceSame       bool
 		metadataGarbage      bool
 		metadataReplace      bool
 		metadataCopy         bool
@@ -2079,6 +2105,7 @@ func testAPICopyObjectHandler(obj ObjectLayer, instanceType, bucketName string,
 			newObjectName:    objectName,
 			copySourceHeader: url.QueryEscape(SlashSeparator + bucketName + SlashSeparator + objectName),
 			accessKey:        credentials.AccessKey,
+			copySourceSame:   true,
 			secretKey:        credentials.SecretKey,
 
 			expectedRespStatus: http.StatusBadRequest,
@@ -2090,6 +2117,7 @@ func testAPICopyObjectHandler(obj ObjectLayer, instanceType, bucketName string,
 		4: {
 			bucketName:       bucketName,
 			newObjectName:    objectName,
+			copySourceSame:   true,
 			copySourceHeader: url.QueryEscape(bucketName + SlashSeparator + objectName),
 			accessKey:        credentials.AccessKey,
 			secretKey:        credentials.SecretKey,
@@ -2140,9 +2168,10 @@ func testAPICopyObjectHandler(obj ObjectLayer, instanceType, bucketName string,
 			metadata: map[string]string{
 				"Content-Type": "application/json",
 			},
-			metadataCopy: true,
-			accessKey:    credentials.AccessKey,
-			secretKey:    credentials.SecretKey,
+			copySourceSame: true,
+			metadataCopy:   true,
+			accessKey:      credentials.AccessKey,
+			secretKey:      credentials.SecretKey,
 
 			expectedRespStatus: http.StatusBadRequest,
 		},
@@ -2306,8 +2335,16 @@ func testAPICopyObjectHandler(obj ObjectLayer, instanceType, bucketName string,
 		apiRouter.ServeHTTP(rec, req)
 		// Assert the response code with the expected status.
 		if rec.Code != testCase.expectedRespStatus {
-			t.Errorf("Test %d: %s:  Expected the response status to be `%d`, but instead found `%d`", i, instanceType, testCase.expectedRespStatus, rec.Code)
-			continue
+			if testCase.copySourceSame {
+				// encryption will rotate creds, so fail only for non-encryption scenario.
+				if GlobalKMS == nil {
+					t.Errorf("Test %d: %s:  Expected the response status to be `%d`, but instead found `%d`", i, instanceType, testCase.expectedRespStatus, rec.Code)
+					continue
+				}
+			} else {
+				t.Errorf("Test %d: %s:  Expected the response status to be `%d`, but instead found `%d`", i, instanceType, testCase.expectedRespStatus, rec.Code)
+				continue
+			}
 		}
 		if rec.Code == http.StatusOK {
 			var cpObjResp CopyObjectResponse
@@ -2319,21 +2356,18 @@ func testAPICopyObjectHandler(obj ObjectLayer, instanceType, bucketName string,
 			// testing whether the copy was successful.
 			// Note that this goes directly to the file system,
 			// so encryption/compression may interfere at some point.
-
-			globalCompressConfigMu.Lock()
-			cfg := globalCompressConfig
-			globalCompressConfigMu.Unlock()
-			if !cfg.Enabled {
-				err = obj.GetObject(context.Background(), testCase.bucketName, testCase.newObjectName, 0, int64(len(bytesData[0].byteData)), buffers[0], "", opts)
-				if err != nil {
-					t.Fatalf("Test %d: %s: Failed to fetch the copied object: <ERROR> %s", i, instanceType, err)
-				}
-				if !bytes.Equal(bytesData[0].byteData, buffers[0].Bytes()) {
-					t.Errorf("Test %d: %s: Data Mismatch: Data fetched back from the copied object doesn't match the original one.", i, instanceType)
-				}
-				buffers[0].Reset()
-			} else {
-				t.Log("object not validated due to compression")
+			buffers[0].Reset()
+			r, err := obj.GetObjectNInfo(context.Background(), testCase.bucketName, testCase.newObjectName, nil, nil, readLock, opts)
+			if err != nil {
+				t.Fatalf("Test %d: %s reading completed file failed: <ERROR> %v", i, instanceType, err)
+			}
+			if _, err = io.Copy(buffers[0], r); err != nil {
+				r.Close()
+				t.Fatalf("Test %d %s: Failed to fetch the copied object: <ERROR> %s", i, instanceType, err)
+			}
+			r.Close()
+			if !bytes.Equal(bytesData[0].byteData, buffers[0].Bytes()) {
+				t.Errorf("Test %d: %s: Data Mismatch: Data fetched back from the copied object doesn't match the original one.", i, instanceType)
 			}
 		}
 
@@ -2379,7 +2413,14 @@ func testAPICopyObjectHandler(obj ObjectLayer, instanceType, bucketName string,
 		// Call the ServeHTTP to execute the handler.
 		apiRouter.ServeHTTP(recV2, reqV2)
 		if recV2.Code != testCase.expectedRespStatus {
-			t.Errorf("Test %d: %s: Expected the response status to be `%d`, but instead found `%d`", i, instanceType, testCase.expectedRespStatus, recV2.Code)
+			if testCase.copySourceSame {
+				// encryption will rotate creds, so fail only for non-encryption scenario.
+				if GlobalKMS == nil {
+					t.Errorf("Test %d: %s:  Expected the response status to be `%d`, but instead found `%d`", i, instanceType, testCase.expectedRespStatus, rec.Code)
+				}
+			} else {
+				t.Errorf("Test %d: %s:  Expected the response status to be `%d`, but instead found `%d`", i+1, instanceType, testCase.expectedRespStatus, rec.Code)
+			}
 		}
 	}