Merge pull request #1182 from restic/fix-1167

local: do not create dirs below data/ for non-existing dir

internal/backend/local/local.go

@@ -25,6 +25,25 @@ var _ restic.Backend = &Local{}
 
 const defaultLayout = "default"
 
+// dirExists returns true if the name exists and is a directory.
+func dirExists(name string) bool {
+	f, err := fs.Open(name)
+	if err != nil {
+		return false
+	}
+
+	fi, err := f.Stat()
+	if err != nil {
+		return false
+	}
+
+	if err = f.Close(); err != nil {
+		return false
+	}
+
+	return fi.IsDir()
+}
+
 // Open opens the local backend as specified by config.
 func Open(cfg Config) (*Local, error) {
 	debug.Log("open local backend at %v (layout %q)", cfg.Path, cfg.Layout)
@@ -35,13 +54,20 @@ func Open(cfg Config) (*Local, error) {
 
 	be := &Local{Config: cfg, Layout: l}
 
-	// create paths for data and refs. MkdirAll does nothing if the directory already exists.
+	// if data dir exists, make sure that all subdirs also exist
+	datadir := be.Dirname(restic.Handle{Type: restic.DataFile})
+	if dirExists(datadir) {
 		for _, d := range be.Paths() {
+			if _, err := filepath.Rel(datadir, d); err != nil {
+				continue
+			}
+
 			err := fs.MkdirAll(d, backend.Modes.Dir)
 			if err != nil {
 				return nil, errors.Wrap(err, "MkdirAll")
 			}
 		}
+	}
 
 	return be, nil
 }

internal/backend/local/local_test.go

@@ -2,6 +2,8 @@ package local_test
 
 import (
 	"io/ioutil"
+	"os"
+	"path/filepath"
 	"testing"
 
 	"github.com/restic/restic/internal/backend/local"
@@ -59,3 +61,57 @@ func TestBackend(t *testing.T) {
 func BenchmarkBackend(t *testing.B) {
 	newTestSuite(t).RunBenchmarks(t)
 }
+
+func readdirnames(t testing.TB, dir string) []string {
+	f, err := os.Open(dir)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	entries, err := f.Readdirnames(-1)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = f.Close()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	return entries
+}
+
+func empty(t testing.TB, dir string) {
+	entries := readdirnames(t, dir)
+	if len(entries) != 0 {
+		t.Fatalf("directory %v is not empty, contains: %v", dir, entries)
+	}
+}
+
+func openclose(t testing.TB, dir string) {
+	cfg := local.Config{Path: dir}
+
+	be, err := local.Open(cfg)
+	if err != nil {
+		t.Logf("Open returned error %v", err)
+	}
+
+	if be != nil {
+		err = be.Close()
+		if err != nil {
+			t.Logf("Close returned error %v", err)
+		}
+	}
+}
+
+func TestOpenNotExistingDirectory(t *testing.T) {
+	dir, cleanup := TempDir(t)
+	defer cleanup()
+
+	// local.Open must not create any files dirs in the repo
+	openclose(t, filepath.Join(dir, "repo"))
+	empty(t, dir)
+
+	openclose(t, dir)
+	empty(t, dir)
+}

internal/backend/sftp/sftp.go

@@ -141,6 +141,10 @@ func (r *SFTP) checkDataSubdirs() error {
 
 	// check if all paths for data/ exist
 	entries, err := r.c.ReadDir(datadir)
+	if r.IsNotExist(err) {
+		return nil
+	}
+
 	if err != nil {
 		return err
 	}