Reduce walk and open cost in fsgofer

Implement WalkGetAttr() to reuse the stat that is already
needed for Walk(). In addition, cache file QID, so it
doesn't need to stat the file to compute it.

open(2) time improved by 10%:

Baseline: 6780 ns
Change: 6083 ns

Also fixed file type which was not being set in all places.

PiperOrigin-RevId: 323102560

1 files changed, 41 insertions, 28 deletions

diff --git a/runsc/fsgofer/fsgofer_test.go b/runsc/fsgofer/fsgofer_test.go
index 5b37e6aa1..94f167417 100644
--- a/runsc/fsgofer/fsgofer_test.go
+++ b/runsc/fsgofer/fsgofer_test.go
@@ -32,7 +32,7 @@ import (
 var allOpenFlags = []p9.OpenFlags{p9.ReadOnly, p9.WriteOnly, p9.ReadWrite}
 
 var (
-	allTypes = []fileType{regular, directory, symlink}
+	allTypes = []uint32{syscall.S_IFREG, syscall.S_IFDIR, syscall.S_IFLNK}
 
 	// allConfs is set in init().
 	allConfs []Config
@@ -109,24 +109,37 @@ func testReadWrite(f p9.File, flags p9.OpenFlags, content []byte) error {
 }
 
 type state struct {
-	root *localFile
-	file *localFile
-	conf Config
-	ft   fileType
+	root     *localFile
+	file     *localFile
+	conf     Config
+	fileType uint32
 }
 
 func (s state) String() string {
-	return fmt.Sprintf("type(%v)", s.ft)
+	return fmt.Sprintf("type(%v)", s.fileType)
+}
+
+func typeName(fileType uint32) string {
+	switch fileType {
+	case syscall.S_IFREG:
+		return "file"
+	case syscall.S_IFDIR:
+		return "directory"
+	case syscall.S_IFLNK:
+		return "symlink"
+	default:
+		panic(fmt.Sprintf("invalid file type for test: %d", fileType))
+	}
 }
 
 func runAll(t *testing.T, test func(*testing.T, state)) {
 	runCustom(t, allTypes, allConfs, test)
 }
 
-func runCustom(t *testing.T, types []fileType, confs []Config, test func(*testing.T, state)) {
+func runCustom(t *testing.T, types []uint32, confs []Config, test func(*testing.T, state)) {
 	for _, c := range confs {
 		for _, ft := range types {
-			name := fmt.Sprintf("%s/%v", configTestName(&c), ft)
+			name := fmt.Sprintf("%s/%s", configTestName(&c), typeName(ft))
 			t.Run(name, func(t *testing.T) {
 				path, name, err := setup(ft)
 				if err != nil {
@@ -150,10 +163,10 @@ func runCustom(t *testing.T, types []fileType, confs []Config, test func(*testin
 				}
 
 				st := state{
-					root: root.(*localFile),
-					file: file.(*localFile),
-					conf: c,
-					ft:   ft,
+					root:     root.(*localFile),
+					file:     file.(*localFile),
+					conf:     c,
+					fileType: ft,
 				}
 				test(t, st)
 				file.Close()
@@ -163,7 +176,7 @@ func runCustom(t *testing.T, types []fileType, confs []Config, test func(*testin
 	}
 }
 
-func setup(ft fileType) (string, string, error) {
+func setup(fileType uint32) (string, string, error) {
 	path, err := ioutil.TempDir(testutil.TmpDir(), "root-")
 	if err != nil {
 		return "", "", fmt.Errorf("ioutil.TempDir() failed, err: %v", err)
@@ -181,26 +194,26 @@ func setup(ft fileType) (string, string, error) {
 	defer root.Close()
 
 	var name string
-	switch ft {
-	case regular:
+	switch fileType {
+	case syscall.S_IFREG:
 		name = "file"
 		_, f, _, _, err := root.Create(name, p9.ReadWrite, 0777, p9.UID(os.Getuid()), p9.GID(os.Getgid()))
 		if err != nil {
 			return "", "", fmt.Errorf("createFile(root, %q) failed, err: %v", "test", err)
 		}
 		defer f.Close()
-	case directory:
+	case syscall.S_IFDIR:
 		name = "dir"
 		if _, err := root.Mkdir(name, 0777, p9.UID(os.Getuid()), p9.GID(os.Getgid())); err != nil {
 			return "", "", fmt.Errorf("root.MkDir(%q) failed, err: %v", name, err)
 		}
-	case symlink:
+	case syscall.S_IFLNK:
 		name = "symlink"
 		if _, err := root.Symlink("/some/target", name, p9.UID(os.Getuid()), p9.GID(os.Getgid())); err != nil {
 			return "", "", fmt.Errorf("root.Symlink(%q) failed, err: %v", name, err)
 		}
 	default:
-		panic(fmt.Sprintf("unknown file type %v", ft))
+		panic(fmt.Sprintf("unknown file type %v", fileType))
 	}
 	return path, name, nil
 }
@@ -214,7 +227,7 @@ func createFile(dir *localFile, name string) (*localFile, error) {
 }
 
 func TestReadWrite(t *testing.T) {
-	runCustom(t, []fileType{directory}, rwConfs, func(t *testing.T, s state) {
+	runCustom(t, []uint32{syscall.S_IFDIR}, rwConfs, func(t *testing.T, s state) {
 		child, err := createFile(s.file, "test")
 		if err != nil {
 			t.Fatalf("%v: createFile() failed, err: %v", s, err)
@@ -244,7 +257,7 @@ func TestReadWrite(t *testing.T) {
 }
 
 func TestCreate(t *testing.T) {
-	runCustom(t, []fileType{directory}, rwConfs, func(t *testing.T, s state) {
+	runCustom(t, []uint32{syscall.S_IFDIR}, rwConfs, func(t *testing.T, s state) {
 		for i, flags := range allOpenFlags {
 			_, l, _, _, err := s.file.Create(fmt.Sprintf("test-%d", i), flags, 0777, p9.UID(os.Getuid()), p9.GID(os.Getgid()))
 			if err != nil {
@@ -261,7 +274,7 @@ func TestCreate(t *testing.T) {
 // TestReadWriteDup tests that a file opened in any mode can be dup'ed and
 // reopened in any other mode.
 func TestReadWriteDup(t *testing.T) {
-	runCustom(t, []fileType{directory}, rwConfs, func(t *testing.T, s state) {
+	runCustom(t, []uint32{syscall.S_IFDIR}, rwConfs, func(t *testing.T, s state) {
 		child, err := createFile(s.file, "test")
 		if err != nil {
 			t.Fatalf("%v: createFile() failed, err: %v", s, err)
@@ -303,7 +316,7 @@ func TestReadWriteDup(t *testing.T) {
 }
 
 func TestUnopened(t *testing.T) {
-	runCustom(t, []fileType{regular}, allConfs, func(t *testing.T, s state) {
+	runCustom(t, []uint32{syscall.S_IFREG}, allConfs, func(t *testing.T, s state) {
 		b := []byte("foobar")
 		if _, err := s.file.WriteAt(b, 0); err != syscall.EBADF {
 			t.Errorf("%v: WriteAt() should have failed, got: %v, expected: syscall.EBADF", s, err)
@@ -325,7 +338,7 @@ func TestUnopened(t *testing.T) {
 // was open with O_PATH, but Open() was not checking for it and allowing the
 // control file to be reused.
 func TestOpenOPath(t *testing.T) {
-	runCustom(t, []fileType{regular}, rwConfs, func(t *testing.T, s state) {
+	runCustom(t, []uint32{syscall.S_IFREG}, rwConfs, func(t *testing.T, s state) {
 		// Fist remove all permissions on the file.
 		if err := s.file.SetAttr(p9.SetAttrMask{Permissions: true}, p9.SetAttr{Permissions: p9.FileMode(0)}); err != nil {
 			t.Fatalf("SetAttr(): %v", err)
@@ -362,7 +375,7 @@ func TestSetAttrPerm(t *testing.T) {
 		valid := p9.SetAttrMask{Permissions: true}
 		attr := p9.SetAttr{Permissions: 0777}
 		got, err := SetGetAttr(s.file, valid, attr)
-		if s.ft == symlink {
+		if s.fileType == syscall.S_IFLNK {
 			if err == nil {
 				t.Fatalf("%v: SetGetAttr(valid, %v) should have failed", s, attr.Permissions)
 			}
@@ -383,7 +396,7 @@ func TestSetAttrSize(t *testing.T) {
 			valid := p9.SetAttrMask{Size: true}
 			attr := p9.SetAttr{Size: size}
 			got, err := SetGetAttr(s.file, valid, attr)
-			if s.ft == symlink || s.ft == directory {
+			if s.fileType == syscall.S_IFLNK || s.fileType == syscall.S_IFDIR {
 				if err == nil {
 					t.Fatalf("%v: SetGetAttr(valid, %v) should have failed", s, attr.Permissions)
 				}
@@ -465,7 +478,7 @@ func TestLink(t *testing.T) {
 		}
 
 		err = dir.Link(s.file, linkFile)
-		if s.ft == directory {
+		if s.fileType == syscall.S_IFDIR {
 			if err != syscall.EPERM {
 				t.Errorf("%v: Link(target, %s) should have failed, got: %v, expected: syscall.EPERM", s, linkFile, err)
 			}
@@ -523,7 +536,7 @@ func TestROMountPanics(t *testing.T) {
 }
 
 func TestWalkNotFound(t *testing.T) {
-	runCustom(t, []fileType{directory}, allConfs, func(t *testing.T, s state) {
+	runCustom(t, []uint32{syscall.S_IFDIR}, allConfs, func(t *testing.T, s state) {
 		if _, _, err := s.file.Walk([]string{"nobody-here"}); err != syscall.ENOENT {
 			t.Errorf("%v: Walk(%q) should have failed, got: %v, expected: syscall.ENOENT", s, "nobody-here", err)
 		}
@@ -544,7 +557,7 @@ func TestWalkDup(t *testing.T) {
 }
 
 func TestReaddir(t *testing.T) {
-	runCustom(t, []fileType{directory}, rwConfs, func(t *testing.T, s state) {
+	runCustom(t, []uint32{syscall.S_IFDIR}, rwConfs, func(t *testing.T, s state) {
 		name := "dir"
 		if _, err := s.file.Mkdir(name, 0777, p9.UID(os.Getuid()), p9.GID(os.Getgid())); err != nil {
 			t.Fatalf("%v: MkDir(%s) failed, err: %v", s, name, err)