AutoUnionFs: Allow removal of symlinks too.

Add a test for AutoUnionFs.

example/autounionfs/main.go

@@ -35,6 +35,7 @@ func main() {
 			AttrTimeout:     1.0,
 			NegativeTimeout: 1.0,
 		},
+		UpdateOnMount: true,
 	}
 
 	gofs := unionfs.NewAutoUnionFs(flag.Arg(1), options)

fuse/pathfilesystem.go

@@ -535,5 +535,4 @@ func (me *FileSystemConnector) getOpenFileData(nodeid uint64, fh uint64) (f File
 	}
 
 	return
-
 }

unionfs/autounion.go

@@ -32,6 +32,9 @@ type AutoUnionFs struct {
 type AutoUnionFsOptions struct {
 	UnionFsOptions
 	fuse.MountOptions
+
+	// If set, run updateKnownFses() after mounting.
+	UpdateOnMount bool
 }
 
 const (
@@ -52,7 +55,9 @@ func NewAutoUnionFs(directory string, options AutoUnionFsOptions) *AutoUnionFs {
 
 func (me *AutoUnionFs) Mount(connector *fuse.FileSystemConnector) fuse.Status {
 	me.connector = connector
+	if me.options.UpdateOnMount {
 		time.AfterFunc(0.1e9, func() { me.updateKnownFses() })
+	}
 	return fuse.OK
 }
 
@@ -62,25 +67,61 @@ func (me *AutoUnionFs) addAutomaticFs(roots []string) {
 	me.addFs(name, roots)
 }
 
-func (me *AutoUnionFs) addFs(name string, roots []string) bool {
-	if name == _CONFIG || name == _STATUS {
-		log.Println("Illegal name for overlay", roots)
-		return false
+func (me *AutoUnionFs) createFs(name string, roots []string) (*UnionFs, fuse.Status)  {
+        me.lock.Lock()
+        defer me.lock.Unlock()
+
+        used := make(map[string]string)
+        for workspace, v := range me.knownFileSystems {
+                used[v.Roots()[0]] = workspace
+        }
+
+        workspace, ok := used[roots[0]]
+        if ok {
+                log.Printf("Already have a union FS for directory %s in workspace %s",
+                        roots[0], workspace)
+                return nil, fuse.EBUSY
         }
 
-	me.lock.Lock()
         var gofs *UnionFs
         if me.knownFileSystems[name] == nil {
                 log.Println("Adding UnionFs for roots", roots)
                 gofs = NewUnionFs(roots, me.options.UnionFsOptions)
                 me.knownFileSystems[name] = gofs
         }
-	me.lock.Unlock()
 
+        return gofs, fuse.OK
+}
+
+func (me *AutoUnionFs) rmFs(name string) (code fuse.Status) {
+	me.lock.Lock()
+	defer me.lock.Unlock()
+
+	fs := me.knownFileSystems[name]
+	if fs == nil {
+		return fuse.ENOENT
+	}
+
+	code = me.connector.Unmount(name)
+	if code.Ok() {
+		me.knownFileSystems[name] = nil, false
+	} else {
+		log.Println("Unmount failed for %s.  Code %v", name, code)
+	}
+
+	return code
+}
+
+func (me *AutoUnionFs) addFs(name string, roots []string) (code fuse.Status) {
+	if name == _CONFIG || name == _STATUS {
+		log.Println("Illegal name for overlay", roots)
+		return fuse.EINVAL
+	}
+        gofs, code := me.createFs(name, roots)
 	if gofs != nil {
 		me.connector.Mount("/"+name, gofs, &me.options.MountOptions)
 	}
-	return true
+	return code
 }
 
 // TODO - should hide these methods.
@@ -152,15 +193,26 @@ func (me *AutoUnionFs) Symlink(pointedTo string, linkName string) (code fuse.Sta
 		}
 
 		name := comps[1]
-		if !me.addFs(name, roots) {
-			return fuse.EPERM
-		}
-		return fuse.OK
+		return me.addFs(name, roots)
 	}
 	return fuse.EPERM
 }
 
 
+func (me *AutoUnionFs) Unlink(path string) (code fuse.Status) {
+	comps := strings.Split(path, "/", -1)
+	if len(comps) != 2 {
+		return fuse.EPERM
+	}
+
+	if comps[0] == _CONFIG {
+		code = me.rmFs(comps[1])
+	} else {
+		code = fuse.ENOENT
+	}
+	return code
+}
+
 // Must define this, because ENOSYS will suspend all GetXAttr calls.
 func (me *AutoUnionFs) GetXAttr(name string, attr string) ([]byte, fuse.Status) {
 	return nil, syscall.ENODATA

unionfs/autounion_test.go

+package unionfs
+
+import (
+	"os"
+	"github.com/hanwen/go-fuse/fuse"
+	"io/ioutil"
+	"fmt"
+	"log"
+	"testing"
+	"time"
+)
+
+var _ = fmt.Print
+var _ = log.Print
+
+const entryTtl = 0.1
+
+var testAOpts = AutoUnionFsOptions{
+	UnionFsOptions: testOpts,
+	MountOptions: fuse.MountOptions{
+		EntryTimeout:    entryTtl,
+		AttrTimeout:     entryTtl,
+		NegativeTimeout: 0,
+	},
+}
+
+
+func WriteFile(name string, contents string) {
+	err := ioutil.WriteFile(name, []byte(contents), 0644)
+	CheckSuccess(err)
+}
+
+func setup(t *testing.T) (workdir string, state *fuse.MountState) {
+	wd := fuse.MakeTempDir()
+	err := os.Mkdir(wd+"/mount", 0700)
+	fuse.CheckSuccess(err)
+
+	err = os.Mkdir(wd+"/store", 0700)
+	fuse.CheckSuccess(err)
+
+	os.Mkdir(wd+"/ro", 0700)
+	fuse.CheckSuccess(err)
+	WriteFile(wd+"/ro/file1", "file1")
+	WriteFile(wd+"/ro/file2", "file2")
+
+	fs := NewAutoUnionFs(wd+"/store", testAOpts)
+	connector := fuse.NewFileSystemConnector(fs, &testAOpts.MountOptions)
+	state = fuse.NewMountState(connector)
+	state.Mount(wd + "/mount")
+	state.Debug = true
+	go state.Loop(false)
+
+	return wd, state
+}
+
+func TestAutoFsSymlink(t *testing.T) {
+	wd, state := setup(t)
+	defer state.Unmount()
+
+	err := os.Mkdir(wd+"/store/foo", 0755)
+	CheckSuccess(err)
+	os.Symlink(wd+"/ro", wd+"/store/foo/READONLY")
+	CheckSuccess(err)
+
+	err = os.Symlink(wd+"/store/foo", wd+"/mount/config/bar")
+	CheckSuccess(err)
+
+	fi, err := os.Lstat(wd+"/mount/bar/file1")
+	CheckSuccess(err)
+
+	err = os.Remove(wd+"/mount/config/bar")
+	CheckSuccess(err)
+
+	// Need time for the unmount to be noticed.
+	log.Println("sleeping...")
+	time.Sleep(entryTtl*2e9)
+
+	fi, _ = os.Lstat(wd+"/mount/foo")
+	if fi != nil {
+		t.Error("Should not have file:", fi)
+	}
+
+	_, err = ioutil.ReadDir(wd+"/mount/config")
+	CheckSuccess(err)
+
+	_, err = os.Lstat(wd+"/mount/foo/file1")
+	CheckSuccess(err)
+}
+
+func TestCreationChecks(t *testing.T) {
+	wd, state := setup(t)
+	defer state.Unmount()
+
+	err := os.Mkdir(wd+"/store/foo", 0755)
+	CheckSuccess(err)
+	os.Symlink(wd+"/ro", wd+"/store/foo/READONLY")
+	CheckSuccess(err)
+
+	err = os.Mkdir(wd+"/store/ws2", 0755)
+	CheckSuccess(err)
+	os.Symlink(wd+"/ro", wd+"/store/ws2/READONLY")
+	CheckSuccess(err)
+
+	err = os.Symlink(wd+"/store/foo", wd+"/mount/config/bar")
+	CheckSuccess(err)
+
+	err = os.Symlink(wd+"/store/foo", wd+"/mount/config/foo")
+	code := fuse.OsErrorToErrno(err)
+	if code != fuse.EBUSY {
+		t.Error("Should return EBUSY", err)
+	}
+
+	err = os.Symlink(wd+"/store/ws2", wd+"/mount/config/config")
+	code = fuse.OsErrorToErrno(err)
+	if code != fuse.EINVAL {
+		t.Error("Should return EINVAL", err)
+	}
+
+}

unionfs/unionfs_test.go

@@ -12,6 +12,7 @@ import (
 
 var _ = fmt.Print
 var _ = log.Print
+
 var CheckSuccess = fuse.CheckSuccess
 
 func TestFilePathHash(t *testing.T) {
@@ -19,15 +20,13 @@ func TestFilePathHash(t *testing.T) {
 	t.Log(filePathHash("xyz/abc"))
 }
 
-const entryTtl = 1
-
 var testOpts = UnionFsOptions{
 	DeletionCacheTTLSecs: entryTtl,
 	DeletionDirName:      "DELETIONS",
 	BranchCacheTTLSecs:   entryTtl,
 }
 
-func setup(t *testing.T) (workdir string, state *fuse.MountState) {
+func setupUfs(t *testing.T) (workdir string, state *fuse.MountState) {
 	wd := fuse.MakeTempDir()
 	err := os.Mkdir(wd+"/mount", 0700)
 	fuse.CheckSuccess(err)
@@ -119,7 +118,7 @@ func remove(path string) {
 }
 
 func TestSymlink(t *testing.T) {
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	err := os.Symlink("/foobar", wd+"/mount/link")
@@ -134,7 +133,7 @@ func TestSymlink(t *testing.T) {
 }
 
 func TestChtimes(t *testing.T) {
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	writeToFile(wd+"/ro/file", "a")
@@ -151,7 +150,7 @@ func TestChtimes(t *testing.T) {
 }
 
 func TestChmod(t *testing.T) {
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	ro_fn := wd + "/ro/file"
@@ -178,7 +177,7 @@ func TestChmod(t *testing.T) {
 }
 
 func TestBasic(t *testing.T) {
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	writeToFile(wd+"/rw/rw", "a")
@@ -241,7 +240,7 @@ func TestBasic(t *testing.T) {
 }
 
 func TestPromote(t *testing.T) {
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	err := os.Mkdir(wd+"/ro/subdir", 0755)
@@ -251,7 +250,7 @@ func TestPromote(t *testing.T) {
 }
 
 func TestCreate(t *testing.T) {
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	err := os.MkdirAll(wd+"/ro/subdir/sub2", 0755)
@@ -262,7 +261,7 @@ func TestCreate(t *testing.T) {
 }
 
 func TestOpenUndeletes(t *testing.T) {
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	writeToFile(wd+"/ro/file", "X")
@@ -274,7 +273,7 @@ func TestOpenUndeletes(t *testing.T) {
 }
 
 func TestMkdir(t *testing.T) {
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	dirname := wd + "/mount/subdir"
@@ -286,7 +285,7 @@ func TestMkdir(t *testing.T) {
 }
 
 func TestMkdirPromote(t *testing.T) {
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	dirname := wd + "/ro/subdir/subdir2"
@@ -321,7 +320,7 @@ func TestRename(t *testing.T) {
 
 	for i, c := range configs {
 		t.Log("Config", i, c)
-		wd, state := setup(t)
+		wd, state := setupUfs(t)
 		if c.f1_ro {
 			writeToFile(wd+"/ro/file1", "c1")
 		}
@@ -361,7 +360,7 @@ func TestRename(t *testing.T) {
 
 func TestWritableDir(t *testing.T) {
 	t.Log("TestWritableDir")
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	dirname := wd + "/ro/subdir"
@@ -377,7 +376,7 @@ func TestWritableDir(t *testing.T) {
 
 func TestTruncate(t *testing.T) {
 	t.Log("TestTruncate")
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	writeToFile(wd+"/ro/file", "hello")
@@ -394,7 +393,7 @@ func TestTruncate(t *testing.T) {
 
 func TestCopyChmod(t *testing.T) {
 	t.Log("TestCopyChmod")
-	wd, state := setup(t)
+	wd, state := setupUfs(t)
 	defer state.Unmount()
 
 	contents := "hello"