Allow checking a read-only repo with --no-lock

cmd/restic/cmd_check.go

@@ -9,8 +9,9 @@ import (
 )
 
 type CmdCheck struct {
-	ReadData    bool `long:"read-data"   description:"Read data blobs" default:"false"`
-	CheckUnused bool `long:"check-unused" description:"Check for unused blobs" default:"false"`
+	ReadData    bool `long:"read-data"    default:"false" description:"Read data blobs"`
+	CheckUnused bool `long:"check-unused" default:"false" description:"Check for unused blobs"`
+	NoLock      bool `long:"no-lock"      default:"false" description:"Do not lock repository, this allows checking read-only"`
 
 	global *GlobalOptions
 }
@@ -39,11 +40,13 @@ func (cmd CmdCheck) Execute(args []string) error {
 		return err
 	}
 
-	cmd.global.Verbosef("Create exclusive lock for repository\n")
-	lock, err := lockRepoExclusive(repo)
-	defer unlockRepo(lock)
-	if err != nil {
-		return err
+	if !cmd.NoLock {
+		cmd.global.Verbosef("Create exclusive lock for repository\n")
+		lock, err := lockRepoExclusive(repo)
+		defer unlockRepo(lock)
+		if err != nil {
+			return err
+		}
 	}
 
 	chkr := checker.New(repo)

cmd/restic/integration_test.go

@@ -103,6 +103,16 @@ func cmdCheckOutput(t testing.TB, global GlobalOptions) string {
 	return string(buf.Bytes())
 }
 
+func cmdCheckNoLock(t testing.TB, global GlobalOptions) {
+	cmd := &CmdCheck{
+		global:      &global,
+		ReadData:    true,
+		CheckUnused: true,
+		NoLock:      true,
+	}
+	OK(t, cmd.Execute(nil))
+}
+
 func cmdRebuildIndex(t testing.TB, global GlobalOptions) {
 	global.stdout = ioutil.Discard
 	cmd := &CmdRebuildIndex{global: &global}
@@ -788,3 +798,20 @@ func TestOptimizeRemoveUnusedBlobs(t *testing.T) {
 		})
 	}
 }
+
+func TestCheckRestoreNoLock(t *testing.T) {
+	withTestEnvironment(t, func(env *testEnvironment, global GlobalOptions) {
+		datafile := filepath.Join("testdata", "repo-restore-permissions-test.tar.gz")
+		SetupTarTestFixture(t, env.base, datafile)
+
+		err := filepath.Walk(env.repo, func(p string, fi os.FileInfo, e error) error {
+			if e != nil {
+				return e
+			}
+			return os.Chmod(p, fi.Mode() & ^(os.FileMode(0222)))
+		})
+		OK(t, err)
+
+		cmdCheckNoLock(t, global)
+	})
+}