storage/xl: Return errVolumeAccessDenied if disks cannot be accessed. (#1621)

Fixes #1614

object-common-multipart.go

@@ -312,7 +312,7 @@ func listMetaBucketMultipartFiles(layer ObjectLayer, prefixPath string, markerPa
 				"marker":    markerPath,
 				"recursive": recursive,
 			}).Debugf("Walk resulted in an error %s", walkResult.err)
-			// 'File not found' or 'Disk not found' is a valid case.
+			// File not found or Disk not found is a valid case.
 			if walkResult.err == errFileNotFound || walkResult.err == errDiskNotFound {
 				return nil, true, nil
 			}

xl-erasure-v1-common.go

@@ -48,6 +48,43 @@ func listFileVersions(partsMetadata []xlMetaV1, errs []error) (versions []int64)
 	return versions
 }
 
+// errsToStorageErr - convert collection of errors into a single
+// error based on total errors and read quorum.
+func (xl XL) errsToStorageErr(errs []error) error {
+	notFoundCount := 0
+	diskNotFoundCount := 0
+	diskAccessDeniedCount := 0
+	for _, err := range errs {
+		if err == errFileNotFound {
+			notFoundCount++
+		} else if err == errDiskNotFound {
+			diskNotFoundCount++
+		} else if err == errVolumeAccessDenied {
+			diskAccessDeniedCount++
+		}
+	}
+	// If we have errors with 'file not found' greater than
+	// readQuroum, return as errFileNotFound.
+	if notFoundCount > len(xl.storageDisks)-xl.readQuorum {
+		return errFileNotFound
+	}
+	// If we have errors with disk not found equal to the
+	// number of disks, return as errDiskNotFound.
+	if diskNotFoundCount == len(xl.storageDisks) {
+		return errDiskNotFound
+	} else if diskNotFoundCount > len(xl.storageDisks)-xl.readQuorum {
+		// If we have errors with 'disk not found' greater than
+		// readQuroum, return as errFileNotFound.
+		return errFileNotFound
+	}
+	// If we have errors with disk not found equal to the
+	// number of disks, return as errDiskNotFound.
+	if diskAccessDeniedCount == len(xl.storageDisks) {
+		return errVolumeAccessDenied
+	}
+	return nil
+}
+
 // Returns slice of online disks needed.
 // - slice returing readable disks.
 // - xlMetaV1
@@ -55,27 +92,9 @@ func listFileVersions(partsMetadata []xlMetaV1, errs []error) (versions []int64)
 // - error if any.
 func (xl XL) listOnlineDisks(volume, path string) (onlineDisks []StorageAPI, mdata xlMetaV1, heal bool, err error) {
 	partsMetadata, errs := xl.getPartsMetadata(volume, path)
-	notFoundCount := 0
-	diskNotFoundCount := 0
-	for _, err := range errs {
-		if err == errFileNotFound || err == errDiskNotFound {
-			notFoundCount++
-			// If we have errors with 'file not found' or 'disk not found' greater than
-			// writeQuroum, return as errFileNotFound.
-			if notFoundCount > len(xl.storageDisks)-xl.readQuorum {
-				return nil, xlMetaV1{}, false, errFileNotFound
+	if err = xl.errsToStorageErr(errs); err != nil {
+		return nil, xlMetaV1{}, false, err
 	}
-		}
-		if err == errDiskNotFound {
-			diskNotFoundCount++
-			// If we have errors with disk not found equal to the
-			// number of disks, return as errDiskNotFound.
-			if diskNotFoundCount == len(xl.storageDisks) {
-				return nil, xlMetaV1{}, false, errDiskNotFound
-			}
-		}
-	}
-
 	highestVersion := int64(0)
 	onlineDisks = make([]StorageAPI, len(xl.storageDisks))
 	// List all the file versions from partsMetadata list.

xl-erasure-v1-createfile.go

@@ -62,13 +62,10 @@ func (xl XL) writeErasure(volume, path string, reader *io.PipeReader, wcloser *w
 	partsMetadata, errs := xl.getPartsMetadata(volume, path)
 	nsMutex.RUnlock(volume, path)
 
-	// Count errors other than fileNotFound, bigger than the allowed
-	// readQuorum, if yes throw an error.
-	metadataReadErrCount := 0
-	for _, err := range errs {
+	// Convert errs into meaningful err to be sent upwards if possible
+	// based on total number of errors and read quorum.
+	err := xl.errsToStorageErr(errs)
 	if err != nil && err != errFileNotFound {
-			metadataReadErrCount++
-			if metadataReadErrCount > xl.readQuorum {
 		log.WithFields(logrus.Fields{
 			"volume": volume,
 			"path":   path,
@@ -76,10 +73,7 @@ func (xl XL) writeErasure(volume, path string, reader *io.PipeReader, wcloser *w
 		reader.CloseWithError(err)
 		return
 	}
-		}
-	}
 
-	var err error
 	// List all the file versions on existing files.
 	versions := listFileVersions(partsMetadata, errs)
 	// Get highest file version.

xl-objects.go

@@ -93,12 +93,14 @@ func newXLObjects(exportPaths ...string) (ObjectLayer, error) {
 		} else {
 			log.Errorf("Unable to check backend format %s", err)
 			if err == errReadQuorum {
-				errMsg := fmt.Sprintf("Not all disks %s on command line are available to meet the read quroum.", exportPaths)
-				return nil, errors.New(errMsg)
-			}
-			if err == errDiskNotFound {
-				errMsg := fmt.Sprintf("All disks %s on command line are not available.", exportPaths)
-				return nil, errors.New(errMsg)
+				errMsg := fmt.Sprintf("Not all disks %s are available, did not meet read quroum.", exportPaths)
+				err = errors.New(errMsg)
+			} else if err == errDiskNotFound {
+				errMsg := fmt.Sprintf("Disks %s not found.", exportPaths)
+				err = errors.New(errMsg)
+			} else if err == errVolumeAccessDenied {
+				errMsg := fmt.Sprintf("Disks %s access permission denied.", exportPaths)
+				err = errors.New(errMsg)
 			}
 			return nil, err
 		}