Fix loopback file locking methods to correctly use the file handle.

Change-Id: I3a67066a6660481bdab81278a91027755973b496

fs/bridge.go

@@ -793,7 +793,7 @@ func (b *rawBridge) SetLk(cancel <-chan struct{}, input *fuse.LkIn) fuse.Status
 	if lops, ok := n.ops.(NodeSetlker); ok {
 		return errnoToStatus(lops.Setlk(&fuse.Context{Caller: input.Caller, Cancel: cancel}, f.file, input.Owner, &input.Lk, input.LkFlags))
 	}
-	if sl, ok := n.ops.(FileSetlker); ok {
+	if sl, ok := f.file.(FileSetlker); ok {
 		return errnoToStatus(sl.Setlk(&fuse.Context{Caller: input.Caller, Cancel: cancel}, input.Owner, &input.Lk, input.LkFlags))
 	}
 	return fuse.ENOTSUP
@@ -803,7 +803,7 @@ func (b *rawBridge) SetLkw(cancel <-chan struct{}, input *fuse.LkIn) fuse.Status
 	if lops, ok := n.ops.(NodeSetlkwer); ok {
 		return errnoToStatus(lops.Setlkw(&fuse.Context{Caller: input.Caller, Cancel: cancel}, f.file, input.Owner, &input.Lk, input.LkFlags))
 	}
-	if sl, ok := n.ops.(FileSetlkwer); ok {
+	if sl, ok := f.file.(FileSetlkwer); ok {
 		return errnoToStatus(sl.Setlkw(&fuse.Context{Caller: input.Caller, Cancel: cancel}, input.Owner, &input.Lk, input.LkFlags))
 	}
 	return fuse.ENOTSUP

fs/simple_test.go

@@ -57,6 +57,7 @@ func (tc *testCase) Clean() {
 
 type testOptions struct {
 	entryCache        bool
+	enableLocks       bool
 	attrCache         bool
 	suppressDebug     bool
 	testDir           string
@@ -112,6 +113,7 @@ func newTestCase(t *testing.T, opts *testOptions) *testCase {
 	mOpts := &fuse.MountOptions{
 		DirectMount:       opts.directMount,
 		DirectMountStrict: opts.directMountStrict,
+		EnableLocks:       opts.enableLocks,
 	}
 	if !opts.suppressDebug {
 		mOpts.Debug = testutil.VerboseTest()
@@ -390,7 +392,10 @@ func TestPosix(t *testing.T) {
 		t.Run(nm, func(t *testing.T) {
 			tc := newTestCase(t, &testOptions{
 				suppressDebug: noisy[nm],
-				attrCache:     true, entryCache: true})
+				attrCache:     true,
+				entryCache:    true,
+				enableLocks:   true,
+			})
 			defer tc.Clean()
 
 			fn(t, tc.mntDir)
@@ -429,7 +434,7 @@ func TestOpenDirectIO(t *testing.T) {
 //
 // Note: Run as
 //
-//     TMPDIR=/var/tmp go test -run TestFsstress
+//	TMPDIR=/var/tmp go test -run TestFsstress
 //
 // to make sure the backing filesystem is ext4. /tmp is tmpfs on modern Linux
 // distributions, and tmpfs does not reuse inode numbers, hiding the problem.

posixtest/test.go

@@ -16,6 +16,7 @@ import (
 	"testing"
 
 	"github.com/hanwen/go-fuse/v2/fuse"
+	"golang.org/x/sys/unix"
 )
 
 // All holds a map of all test functions
@@ -41,6 +42,8 @@ var All = map[string]func(*testing.T, string){
 	"OpenAt":                     OpenAt,
 	"Fallocate":                  Fallocate,
 	"DirSeek":                    DirSeek,
+	"FcntlFlockSetLk":            FcntlFlockSetLk,
+	"FcntlFlockLocksFile":        FcntlFlockLocksFile,
 }
 
 func DirectIO(t *testing.T, mnt string) {
@@ -631,3 +634,67 @@ func Fallocate(t *testing.T, mnt string) {
 			fi.Size())
 	}
 }
+
+func FcntlFlockSetLk(t *testing.T, mnt string) {
+	for i, cmd := range []int{syscall.F_SETLK, syscall.F_SETLKW} {
+		filename := mnt + fmt.Sprintf("/file%d", i)
+		f1, err := os.Create(filename)
+		if err != nil {
+			t.Fatalf("Open failed: %v", err)
+		}
+		defer f1.Close()
+		wlk := syscall.Flock_t{
+			Type:  syscall.F_WRLCK,
+			Start: 0,
+			Len:   0,
+		}
+		if err := syscall.FcntlFlock(f1.Fd(), cmd, &wlk); err != nil {
+			t.Fatalf("FcntlFlock failed: %v", err)
+		}
+
+		f2, err := os.OpenFile(filename, os.O_RDWR, 0766)
+		if err != nil {
+			t.Fatalf("Open failed: %v", err)
+		}
+		defer f2.Close()
+		lk := syscall.Flock_t{}
+		if err := syscall.FcntlFlock(f2.Fd(), unix.F_OFD_GETLK, &lk); err != nil {
+			t.Errorf("FcntlFlock failed: %v", err)
+		}
+		if lk.Type != syscall.F_WRLCK {
+			t.Errorf("got lk.Type=%v, want %v", lk.Type, syscall.F_WRLCK)
+
+		}
+	}
+}
+
+func FcntlFlockLocksFile(t *testing.T, mnt string) {
+	filename := mnt + "/test"
+	f1, err := os.Create(filename)
+	if err != nil {
+		t.Fatalf("Open failed: %v", err)
+	}
+	defer f1.Close()
+	wlk := syscall.Flock_t{
+		Type:  syscall.F_WRLCK,
+		Start: 0,
+		Len:   0,
+	}
+	if err := syscall.FcntlFlock(f1.Fd(), syscall.F_SETLK, &wlk); err != nil {
+		t.Fatalf("FcntlFlock failed: %v", err)
+	}
+
+	f2, err := os.OpenFile(filename, os.O_RDWR, 0766)
+	if err != nil {
+		t.Fatalf("Open failed: %v", err)
+	}
+	defer f2.Close()
+	rlk := syscall.Flock_t{
+		Type:  syscall.F_RDLCK,
+		Start: 0,
+		Len:   0,
+	}
+	if err := syscall.FcntlFlock(f2.Fd(), syscall.F_SETLK, &rlk); err != syscall.EAGAIN {
+		t.Errorf("FcntlFlock returned %v, expected EAGAIN", err)
+	}
+}