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|
//go:build linux
package dmflakey
import (
"errors"
"flag"
"fmt"
"os"
"os/exec"
"path/filepath"
"testing"
"time"
testutils "go.etcd.io/bbolt/tests/utils"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"golang.org/x/sys/unix"
)
func TestMain(m *testing.M) {
flag.Parse()
testutils.RequiresRoot()
os.Exit(m.Run())
}
func TestBasic(t *testing.T) {
for _, fsType := range []FSType{FSTypeEXT4, FSTypeXFS} {
t.Run(string(fsType), func(t *testing.T) {
tmpDir := t.TempDir()
flakey, err := InitFlakey("go-dmflakey", tmpDir, fsType, "")
require.NoError(t, err, "init flakey")
defer func() {
assert.NoError(t, flakey.Teardown())
}()
target := filepath.Join(tmpDir, "root")
require.NoError(t, os.MkdirAll(target, 0600))
require.NoError(t, mount(target, flakey.DevicePath(), ""))
defer func() {
assert.NoError(t, unmount(target))
}()
file := filepath.Join(target, "test")
assert.NoError(t, writeFile(file, []byte("hello, world"), 0600, true))
assert.NoError(t, unmount(target))
assert.NoError(t, flakey.Teardown())
})
}
}
func TestDropWritesExt4(t *testing.T) {
flakey, root := initFlakey(t, FSTypeEXT4)
// commit=1000 is to delay commit triggered by writeback thread
require.NoError(t, mount(root, flakey.DevicePath(), "commit=1000"))
// ensure testdir/f1 is synced.
target := filepath.Join(root, "testdir")
require.NoError(t, os.MkdirAll(target, 0600))
f1 := filepath.Join(target, "f1")
assert.NoError(t, writeFile(f1, []byte("hello, world from f1"), 0600, false))
require.NoError(t, syncfs(f1))
// testdir/f2 is created but without fsync
f2 := filepath.Join(target, "f2")
assert.NoError(t, writeFile(f2, []byte("hello, world from f2"), 0600, false))
// simulate power failure
assert.NoError(t, flakey.DropWrites())
assert.NoError(t, unmount(root))
assert.NoError(t, flakey.AllowWrites())
require.NoError(t, mount(root, flakey.DevicePath(), ""))
data, err := os.ReadFile(f1)
assert.NoError(t, err)
assert.Equal(t, "hello, world from f1", string(data))
_, err = os.ReadFile(f2)
assert.True(t, errors.Is(err, os.ErrNotExist))
}
func TestErrorWritesExt4(t *testing.T) {
flakey, root := initFlakey(t, FSTypeEXT4)
// commit=1000 is to delay commit triggered by writeback thread
require.NoError(t, mount(root, flakey.DevicePath(), "commit=1000"))
// inject IO failure on write
assert.NoError(t, flakey.ErrorWrites())
f1 := filepath.Join(root, "f1")
err := writeFile(f1, []byte("hello, world during failpoint"), 0600, true)
assert.ErrorContains(t, err, "input/output error")
// resume
assert.NoError(t, flakey.AllowWrites())
err = writeFile(f1, []byte("hello, world"), 0600, true)
assert.NoError(t, err)
assert.NoError(t, unmount(root))
require.NoError(t, mount(root, flakey.DevicePath(), ""))
data, err := os.ReadFile(f1)
assert.NoError(t, err)
assert.Equal(t, "hello, world", string(data))
}
func initFlakey(t *testing.T, fsType FSType) (_ Flakey, root string) {
tmpDir := t.TempDir()
target := filepath.Join(tmpDir, "root")
require.NoError(t, os.MkdirAll(target, 0600))
flakey, err := InitFlakey("go-dmflakey", tmpDir, fsType, "")
require.NoError(t, err, "init flakey")
t.Cleanup(func() {
assert.NoError(t, unmount(target))
assert.NoError(t, flakey.Teardown())
})
return flakey, target
}
func writeFile(name string, data []byte, perm os.FileMode, sync bool) error {
f, err := os.OpenFile(name, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, perm)
if err != nil {
return err
}
defer f.Close()
if _, err = f.Write(data); err != nil {
return err
}
if sync {
return f.Sync()
}
return nil
}
func syncfs(file string) error {
f, err := os.Open(file)
if err != nil {
return fmt.Errorf("failed to open %s: %w", file, err)
}
defer f.Close()
_, _, errno := unix.Syscall(unix.SYS_SYNCFS, uintptr(f.Fd()), 0, 0)
if errno != 0 {
return errno
}
return nil
}
func mount(target string, devPath string, opt string) error {
args := []string{"-o", opt, devPath, target}
output, err := exec.Command("mount", args...).CombinedOutput()
if err != nil {
return fmt.Errorf("failed to mount (args: %v) (out: %s): %w",
args, string(output), err)
}
return nil
}
func unmount(target string) error {
for i := 0; i < 50; i++ {
if err := unix.Unmount(target, 0); err != nil {
switch err {
case unix.EBUSY:
time.Sleep(500 * time.Millisecond)
continue
case unix.EINVAL:
default:
return fmt.Errorf("failed to umount %s: %w", target, err)
}
}
return nil
}
return unix.EBUSY
}
|
