ignore swapped drives instead of throwing errors (#13655)

- add checks such that swapped disks are detected
  and ignored - never used for normal operations.

- implement `unrecognizedDisk` to be ignored with
  all operations returning `errDiskNotFound`.

- also add checks such that we do not load unexpected
  disks while connecting automatically.

- additionally humanize the values when printing the errors.

Bonus: fixes handling of non-quorum situations in
getLatestFileInfo(), that does not work when 2 drives
are down, currently this function would return errors
incorrectly.

cmd/storage-interface.go

@@ -86,46 +86,163 @@ type StorageAPI interface {
 	SetDiskLoc(poolIdx, setIdx, diskIdx int)    // Set location indexes.
 }
 
-// storageReader is an io.Reader view of a disk
-type storageReader struct {
-	storage      StorageAPI
-	volume, path string
-	offset       int64
+type unrecognizedDisk struct {
+	storage StorageAPI
 }
 
-func (r *storageReader) Read(p []byte) (n int, err error) {
-	nn, err := r.storage.ReadFile(context.TODO(), r.volume, r.path, r.offset, p, nil)
-	r.offset += nn
-	n = int(nn)
+func (p *unrecognizedDisk) WalkDir(ctx context.Context, opts WalkDirOptions, wr io.Writer) (err error) {
+	return errDiskNotFound
+}
 
-	if err == io.ErrUnexpectedEOF && nn > 0 {
-		err = io.EOF
+func (p *unrecognizedDisk) String() string {
+	return p.storage.String()
+}
+
+func (p *unrecognizedDisk) IsOnline() bool {
+	return false
+}
+
+func (p *unrecognizedDisk) LastConn() time.Time {
+	return p.storage.LastConn()
+}
+
+func (p *unrecognizedDisk) IsLocal() bool {
+	return p.storage.IsLocal()
+}
+
+func (p *unrecognizedDisk) Endpoint() Endpoint {
+	return p.storage.Endpoint()
+}
+
+func (p *unrecognizedDisk) Hostname() string {
+	return p.storage.Hostname()
+}
+
+func (p *unrecognizedDisk) Healing() *healingTracker {
+	return nil
+}
+
+func (p *unrecognizedDisk) NSScanner(ctx context.Context, cache dataUsageCache, updates chan<- dataUsageEntry) (dataUsageCache, error) {
+	return dataUsageCache{}, errDiskNotFound
+}
+
+func (p *unrecognizedDisk) GetDiskLoc() (poolIdx, setIdx, diskIdx int) {
+	return -1, -1, -1
+}
+
+func (p *unrecognizedDisk) SetDiskLoc(poolIdx, setIdx, diskIdx int) {
+}
+
+func (p *unrecognizedDisk) Close() error {
+	return p.storage.Close()
+}
+
+func (p *unrecognizedDisk) GetDiskID() (string, error) {
+	return "", errDiskNotFound
+}
+
+func (p *unrecognizedDisk) SetDiskID(id string) {
+}
+
+func (p *unrecognizedDisk) DiskInfo(ctx context.Context) (info DiskInfo, err error) {
+	return info, errDiskNotFound
+}
+
+func (p *unrecognizedDisk) MakeVolBulk(ctx context.Context, volumes ...string) (err error) {
+	return errDiskNotFound
+}
+
+func (p *unrecognizedDisk) MakeVol(ctx context.Context, volume string) (err error) {
+	return errDiskNotFound
+}
+
+func (p *unrecognizedDisk) ListVols(ctx context.Context) ([]VolInfo, error) {
+	return nil, errDiskNotFound
+}
+
+func (p *unrecognizedDisk) StatVol(ctx context.Context, volume string) (vol VolInfo, err error) {
+	return vol, errDiskNotFound
+}
+
+func (p *unrecognizedDisk) DeleteVol(ctx context.Context, volume string, forceDelete bool) (err error) {
+	return errDiskNotFound
+}
+
+func (p *unrecognizedDisk) ListDir(ctx context.Context, volume, dirPath string, count int) ([]string, error) {
+	return nil, errDiskNotFound
+}
+
+func (p *unrecognizedDisk) ReadFile(ctx context.Context, volume string, path string, offset int64, buf []byte, verifier *BitrotVerifier) (n int64, err error) {
+	return 0, errDiskNotFound
+}
+
+func (p *unrecognizedDisk) AppendFile(ctx context.Context, volume string, path string, buf []byte) (err error) {
+	return errDiskNotFound
+}
+
+func (p *unrecognizedDisk) CreateFile(ctx context.Context, volume, path string, size int64, reader io.Reader) error {
+	return errDiskNotFound
+}
+
+func (p *unrecognizedDisk) ReadFileStream(ctx context.Context, volume, path string, offset, length int64) (io.ReadCloser, error) {
+	return nil, errDiskNotFound
+}
+
+func (p *unrecognizedDisk) RenameFile(ctx context.Context, srcVolume, srcPath, dstVolume, dstPath string) error {
+	return errDiskNotFound
+}
+
+func (p *unrecognizedDisk) RenameData(ctx context.Context, srcVolume, srcPath string, fi FileInfo, dstVolume, dstPath string) error {
+	return errDiskNotFound
+}
+
+func (p *unrecognizedDisk) CheckParts(ctx context.Context, volume string, path string, fi FileInfo) (err error) {
+	return errDiskNotFound
+}
+
+func (p *unrecognizedDisk) Delete(ctx context.Context, volume string, path string, recursive bool) (err error) {
+	return errDiskNotFound
+}
+
+// DeleteVersions deletes slice of versions, it can be same object
+// or multiple objects.
+func (p *unrecognizedDisk) DeleteVersions(ctx context.Context, volume string, versions []FileInfoVersions) (errs []error) {
+	errs = make([]error, len(versions))
+
+	for i := range errs {
+		errs[i] = errDiskNotFound
 	}
-	return
+	return errs
 }
 
-// storageWriter is a io.Writer view of a disk.
-type storageWriter struct {
-	storage      StorageAPI
-	volume, path string
+func (p *unrecognizedDisk) VerifyFile(ctx context.Context, volume, path string, fi FileInfo) error {
+	return errDiskNotFound
 }
 
-func (w *storageWriter) Write(p []byte) (n int, err error) {
-	err = w.storage.AppendFile(context.TODO(), w.volume, w.path, p)
-	if err == nil {
-		n = len(p)
-	}
-	return
+func (p *unrecognizedDisk) WriteAll(ctx context.Context, volume string, path string, b []byte) (err error) {
+	return errDiskNotFound
 }
 
-// StorageWriter returns a new io.Writer which appends data to the file
-// at the given disk, volume and path.
-func StorageWriter(storage StorageAPI, volume, path string) io.Writer {
-	return &storageWriter{storage, volume, path}
+func (p *unrecognizedDisk) DeleteVersion(ctx context.Context, volume, path string, fi FileInfo, forceDelMarker bool) (err error) {
+	return errDiskNotFound
 }
 
-// StorageReader returns a new io.Reader which reads data to the file
-// at the given disk, volume, path and offset.
-func StorageReader(storage StorageAPI, volume, path string, offset int64) io.Reader {
-	return &storageReader{storage, volume, path, offset}
+func (p *unrecognizedDisk) UpdateMetadata(ctx context.Context, volume, path string, fi FileInfo) (err error) {
+	return errDiskNotFound
+}
+
+func (p *unrecognizedDisk) WriteMetadata(ctx context.Context, volume, path string, fi FileInfo) (err error) {
+	return errDiskNotFound
+}
+
+func (p *unrecognizedDisk) ReadVersion(ctx context.Context, volume, path, versionID string, readData bool) (fi FileInfo, err error) {
+	return fi, errDiskNotFound
+}
+
+func (p *unrecognizedDisk) ReadAll(ctx context.Context, volume string, path string) (buf []byte, err error) {
+	return nil, errDiskNotFound
+}
+
+func (p *unrecognizedDisk) StatInfoFile(ctx context.Context, volume, path string, glob bool) (stat []StatInfo, err error) {
+	return nil, errDiskNotFound
 }