Exit on WAL commit failure (#405)

Author: benbjohnson

cmd/litefs/mount_linux.go

@@ -35,7 +35,9 @@ type MountCommand struct {
 
 	Config Config
 
-	OS          litefs.OS
+	OS   litefs.OS
+	Exit func(int)
+
 	Store       *litefs.Store
 	Leaser      litefs.Leaser
 	FileSystem  *fuse.FileSystem
@@ -52,6 +54,7 @@ func NewMountCommand() *MountCommand {
 		execCh: make(chan error),
 		Config: NewConfig(),
 		OS:     &internal.SystemOS{},
+		Exit:   os.Exit,
 	}
 }
 
@@ -351,6 +354,7 @@ func (c *MountCommand) initConsul(ctx context.Context) (err error) {
 func (c *MountCommand) initStore(ctx context.Context) error {
 	c.Store = litefs.NewStore(c.Config.Data.Dir, c.Config.Lease.Candidate)
 	c.Store.OS = c.OS
+	c.Store.Exit = c.Exit
 	c.Store.StrictVerify = c.Config.StrictVerify
 	c.Store.Compress = c.Config.Data.Compress
 	c.Store.Retention = c.Config.Data.Retention

cmd/litefs/mount_test.go

@@ -30,6 +30,7 @@ import (
 	main "github.com/superfly/litefs/cmd/litefs"
 	"github.com/superfly/litefs/internal"
 	"github.com/superfly/litefs/internal/testingutil"
+	"github.com/superfly/litefs/mock"
 	"github.com/superfly/ltx"
 	"golang.org/x/exp/slog"
 	"golang.org/x/net/http2"
@@ -328,6 +329,60 @@ func TestSingleNode_DropDB(t *testing.T) {
 	}
 }
 
+func TestSingleNode_ErrCommitWAL(t *testing.T) {
+	if !testingutil.IsWALMode() {
+		t.Skip("test failure only applies to WAL mode, skipping")
+	}
+
+	mos := mock.NewOS()
+	dir := t.TempDir()
+	cmd0 := newMountCommand(t, dir, nil)
+	cmd0.OS = mos
+	runMountCommand(t, cmd0)
+	db := testingutil.OpenSQLDB(t, filepath.Join(cmd0.Config.FUSE.Dir, "db"))
+
+	if _, err := db.Exec(`CREATE TABLE t (x)`); err != nil {
+		t.Fatal(err)
+	} else if _, err := db.Exec(`INSERT INTO t VALUES (100)`); err != nil {
+		t.Fatal(err)
+	}
+
+	var exitCode int
+	cmd0.Store.Exit = func(code int) {
+		exitCode = code
+	}
+	mos.OpenFunc = func(op, name string) (*os.File, error) {
+		if op == "COMMITWAL:WAL" {
+			return nil, fmt.Errorf("marker")
+		}
+		return os.Open(name)
+	}
+	if _, err := db.Exec(`INSERT INTO t VALUES (200)`); err != nil {
+		t.Fatal(err)
+	}
+
+	if got, want := exitCode, 99; got != want {
+		t.Fatalf("exit=%d, want=%d", got, want)
+	}
+	if err := db.Close(); err != nil {
+		t.Fatal(err)
+	} else if err := cmd0.Close(); err != nil {
+		t.Fatal(err)
+	}
+
+	// Restart the mount command.
+	cmd0 = runMountCommand(t, newMountCommand(t, dir, nil))
+	db = testingutil.OpenSQLDB(t, filepath.Join(cmd0.Config.FUSE.Dir, "db"))
+
+	// Ensure the second insert was not processed.
+	var x int
+	if err := db.QueryRow(`SELECT SUM(x) FROM t`).Scan(&x); err != nil {
+		t.Fatal(err)
+	} else if got, want := x, 100; got != want {
+		t.Fatalf("x=%d, want %d", got, want)
+	}
+}
+
 func TestSingleNode_BackupClient(t *testing.T) {
 	t.Run("OK", func(t *testing.T) {
 		cmd0 := newMountCommand(t, t.TempDir(), nil)