add-go-fuse-to-inject-filesystem-error

Author: qiffang

testutil/fs_hook.go

@@ -0,0 +1,200 @@
+package testutil
+
+import (
+	"fmt"
+	"path/filepath"
+	"time"
+
+	"github.com/hanwen/go-fuse/fuse"
+	"github.com/hanwen/go-fuse/fuse/nodefs"
+	"github.com/hanwen/go-fuse/fuse/pathfs"
+	log "github.com/sirupsen/logrus"
+)
+
+type HookFs struct {
+	Original   string
+	Mountpoint string
+	FsName     string
+	fs         pathfs.FileSystem
+	hook       Hook
+}
+
+func NewHookFs(original string, mountpoint string, hook Hook) (*HookFs, error) {
+	log.WithFields(log.Fields{
+		"original":   original,
+		"mountpoint": mountpoint,
+	}).Debug("Hooking a fs")
+
+	loopbackfs := pathfs.NewLoopbackFileSystem(original)
+	hookfs := &HookFs{
+		Original:   original,
+		Mountpoint: mountpoint,
+		FsName:     "hookfs",
+		fs:         loopbackfs,
+		hook:       hook,
+	}
+	return hookfs, nil
+}
+
+func (h *HookFs) String() string {
+	return fmt.Sprintf("HookFs{Original=%s, Mountpoint=%s, FsName=%s, Underlying fs=%s, hook=%s}",
+		h.Original, h.Mountpoint, h.FsName, h.fs.String(), h.hook)
+}
+
+func (h *HookFs) SetDebug(debug bool) {
+	h.fs.SetDebug(debug)
+}
+
+func (h *HookFs) GetAttr(name string, context *fuse.Context) (*fuse.Attr, fuse.Status) {
+	return h.fs.GetAttr(name, context)
+}
+
+func (h *HookFs) Chmod(name string, mode uint32, context *fuse.Context) fuse.Status {
+	return h.fs.Chmod(name, mode, context)
+}
+
+func (h *HookFs) Chown(name string, uid uint32, gid uint32, context *fuse.Context) fuse.Status {
+	return h.fs.Chown(name, uid, gid, context)
+}
+
+func (h *HookFs) Utimens(name string, Atime *time.Time, Mtime *time.Time, context *fuse.Context) fuse.Status {
+	return h.fs.Utimens(name, Atime, Mtime, context)
+}
+
+func (h *HookFs) Truncate(name string, size uint64, context *fuse.Context) fuse.Status {
+	return h.fs.Truncate(name, size, context)
+}
+
+func (h *HookFs) Access(name string, mode uint32, context *fuse.Context) fuse.Status {
+	return h.fs.Access(name, mode, context)
+}
+
+func (h *HookFs) Link(oldName string, newName string, context *fuse.Context) fuse.Status {
+	return h.fs.Link(oldName, newName, context)
+}
+
+func (h *HookFs) Mkdir(name string, mode uint32, context *fuse.Context) fuse.Status {
+	return h.fs.Mkdir(name, mode, context)
+}
+
+func (h *HookFs) Mknod(name string, mode uint32, dev uint32, context *fuse.Context) fuse.Status {
+	return h.fs.Mknod(name, mode, dev, context)
+}
+
+func (h *HookFs) Rename(oldName string, newName string, context *fuse.Context) fuse.Status {
+	hook, hookEnabled := h.hook.(HookOnRename)
+	if hookEnabled {
+		preHooked, err := hook.PreRename(oldName, newName)
+		if preHooked {
+			if err != nil {
+				return fuse.ToStatus(err)
+			}
+		}
+	}
+
+	status := h.fs.Rename(oldName, newName, context)
+
+	if hookEnabled {
+		postHooked, err := hook.PostRename(oldName, newName)
+		if postHooked {
+			if err != nil {
+				return fuse.ToStatus(err)
+			}
+		}
+	}
+
+	return status
+}
+
+func (h *HookFs) Rmdir(name string, context *fuse.Context) fuse.Status {
+	return h.fs.Rmdir(name, context)
+}
+
+func (h *HookFs) Unlink(name string, context *fuse.Context) fuse.Status {
+	return h.fs.Unlink(name, context)
+}
+
+func (h *HookFs) GetXAttr(name string, attribute string, context *fuse.Context) ([]byte, fuse.Status) {
+	return h.fs.GetXAttr(name, attribute, context)
+}
+
+func (h *HookFs) ListXAttr(name string, context *fuse.Context) ([]string, fuse.Status) {
+	return h.fs.ListXAttr(name, context)
+}
+
+func (h *HookFs) RemoveXAttr(name string, attr string, context *fuse.Context) fuse.Status {
+	return h.fs.RemoveXAttr(name, attr, context)
+}
+
+func (h *HookFs) SetXAttr(name string, attr string, data []byte, flags int, context *fuse.Context) fuse.Status {
+	return h.fs.SetXAttr(name, attr, data, flags, context)
+}
+
+func (h *HookFs) OnMount(nodeFs *pathfs.PathNodeFs) {
+	h.fs.OnMount(nodeFs)
+}
+
+func (h *HookFs) OnUnmount() {
+	h.fs.OnUnmount()
+}
+
+func (h *HookFs) Open(name string, flags uint32, context *fuse.Context) (nodefs.File, fuse.Status) {
+	return h.fs.Open(name, flags, context)
+}
+
+func (h *HookFs) Create(name string, flags uint32, mode uint32, context *fuse.Context) (nodefs.File, fuse.Status) {
+	return h.fs.Create(name, flags, mode, context)
+}
+
+func (h *HookFs) OpenDir(name string, context *fuse.Context) ([]fuse.DirEntry, fuse.Status) {
+	return h.fs.OpenDir(name, context)
+}
+
+func (h *HookFs) Symlink(value string, linkName string, context *fuse.Context) fuse.Status {
+	return h.fs.Symlink(value, linkName, context)
+}
+
+func (h *HookFs) Readlink(name string, context *fuse.Context) (string, fuse.Status) {
+	return h.fs.Readlink(name, context)
+}
+
+func (h *HookFs) StatFs(name string) *fuse.StatfsOut {
+	return h.fs.StatFs(name)
+}
+
+func (h *HookFs) NewServe() (*fuse.Server, error) {
+	server, err := newHookServer(h)
+	if err != nil {
+		return nil, err
+	}
+
+	return server, nil
+}
+
+//tests will want to run this in a  goroutine.
+func (h *HookFs) Start(server *fuse.Server) {
+	server.Serve()
+}
+
+func newHookServer(hookfs *HookFs) (*fuse.Server, error) {
+	opts := &nodefs.Options{
+		NegativeTimeout: time.Second,
+		AttrTimeout:     time.Second,
+		EntryTimeout:    time.Second,
+	}
+	pathFsOpts := &pathfs.PathNodeFsOptions{ClientInodes: true}
+	pathFs := pathfs.NewPathNodeFs(hookfs, pathFsOpts)
+	conn := nodefs.NewFileSystemConnector(pathFs.Root(), opts)
+	originalAbs, _ := filepath.Abs(hookfs.Original)
+	mOpts := &fuse.MountOptions{
+		AllowOther: true,
+		Name:       hookfs.FsName,
+		FsName:     originalAbs,
+	}
+	server, err := fuse.NewServer(conn.RawFS(), hookfs.Mountpoint, mOpts)
+	if err != nil {
+		return nil, err
+	}
+
+	return server, nil
+}

testutil/hook.go

@@ -0,0 +1,10 @@
+package testutil
+
+type Hook interface{}
+
+type HookContext interface{}
+
+type HookOnRename interface {
+	PreRename(oldPatgh string, newPath string) (hooked bool, err error)
+	PostRename(oldPatgh string, newPath string) (hooked bool, err error)
+}

testutil/hook_test.go

@@ -0,0 +1,68 @@
+package testutil
+
+import (
+	"fmt"
+	"github.com/hanwen/go-fuse/fuse"
+	"log"
+	"os"
+	"syscall"
+	"testing"
+)
+
+func TestRenameHook_PreRenameHookRenameTest(t *testing.T) {
+	//init action
+	original := "/tmp/o"
+	mountpoint := "/tmp/m"
+	server := newFuseServer(t, original, mountpoint)
+	//remember to call unmount after you do not use it
+	defer cleanUp(server)
+
+	//normal logic
+	os.Create("/tmp/m/tsdb.txt")
+	//rename should be failed
+	err := os.Rename("/tmp/m/tsdb.txt", "/tmp/m/tsdbNew.txt")
+	NotOk(t, err)
+	fmt.Println(err)
+}
+
+func newFuseServer(t *testing.T, original,mountpoint string)(*fuse.Server){
+	createDirIfAbsent(original)
+	createDirIfAbsent(mountpoint)
+	fs, err :=  NewHookFs("/tmp/o", "/tmp/m", &TestRenameHook{})
+	Ok(t, err)
+	server, err := fs.NewServe()
+	if err != nil {
+		log.Fatal("please execute `fusermount -u $mountpoint`")
+	}
+	Ok(t, err)
+	go func(){
+		fs.Start(server)
+	}()
+
+	return server
+}
+
+func cleanUp(server *fuse.Server) {
+	err := server.Unmount()
+	if err != nil {
+		log.Fatal("umount failed, please umount the mountpoint by manual operation", err)
+	}
+}
+
+func createDirIfAbsent(name string) {
+	 _, err := os.Stat(name)
+	 if err != nil {
+	 	os.Mkdir(name, os.ModePerm)
+	 }
+}
+
+type TestRenameHook struct {}
+
+func (h *TestRenameHook) PreRename(oldPatgh string, newPath string) (hooked bool, err error) {
+	log.Printf("renamed file from %s to %s", oldPatgh, newPath)
+	return true, syscall.EIO
+}
+func (h *TestRenameHook) PostRename(oldPatgh string, newPath string) (hooked bool, err error) {
+	return false, nil
+}
+