Handle EBADF returns from open file attribute operations.

fuse/api.go

@@ -136,7 +136,7 @@ type FileSystem interface {
 
 // A File object should be returned from FileSystem.Open and
 // FileSystem.Create.  Include DefaultFile into the struct to inherit
-// a default null implementation.
+// a default null implementation.  
 //
 // TODO - should File be thread safe?
 // TODO - should we pass a *Context argument?
@@ -153,15 +153,17 @@ type File interface {
 
 	Read(*ReadIn, BufferPool) ([]byte, Status)
 	Write(*WriteIn, []byte) (written uint32, code Status)
-	Truncate(size uint64) Status
+	Flush() Status
+	Release()
+	Fsync(*FsyncIn) (code Status)
 
+	// The methods below may be called on closed files, due to
+	// concurrency.  In that case, you should return EBADF.
+	Truncate(size uint64) Status
 	GetAttr() (*os.FileInfo, Status)
 	Chown(uid uint32, gid uint32) Status
 	Chmod(perms uint32) Status
 	Utimens(atimeNs uint64, mtimeNs uint64) Status
-	Flush() Status
-	Release()
-	Fsync(*FsyncIn) (code Status)
 }
 
 // Wrap a File return in this to set FUSE flags.  Also used internally

fuse/cache_test.go

@@ -5,6 +5,7 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
+	"sync"
 	"testing"
 )
 
@@ -138,3 +139,48 @@ func TestNonseekable(t *testing.T) {
 		t.Errorf("file was opened nonseekable, but seek successful")
 	}
 }
+
+func TestGetAttrRace(t *testing.T) {
+	dir, err := ioutil.TempDir("", "go-fuse")
+	CheckSuccess(err)
+	defer os.RemoveAll(dir)
+	os.Mkdir(dir+"/mnt", 0755)
+	os.Mkdir(dir+"/orig", 0755)
+
+	fs := NewLoopbackFileSystem(dir + "/orig")
+	pfs := NewPathNodeFs(fs, nil)
+	state, conn, err := MountNodeFileSystem(dir+"/mnt", pfs,
+		&FileSystemOptions{})
+	CheckSuccess(err)
+	state.Debug = VerboseTest()
+	conn.Debug = VerboseTest()
+	pfs.Debug = VerboseTest()
+	go state.Loop()
+
+	defer state.Unmount()
+
+	var wg sync.WaitGroup
+
+	n := 100
+	wg.Add(n)
+	var statErr os.Error
+	for i := 0; i < n; i++ {
+		go func() {
+			defer wg.Done()
+			fn := dir + "/mnt/file"
+			err := ioutil.WriteFile(fn, []byte{42}, 0644)
+			if err != nil {
+				statErr = err
+				return
+			}
+			_, err = os.Lstat(fn)
+			if err != nil {
+				statErr = err
+			}
+		}()
+	}
+	wg.Wait()
+	if statErr != nil {
+		t.Error(statErr)
+	}
+}

fuse/fsops.go

@@ -172,6 +172,7 @@ func (me *FileSystemConnector) SetAttr(header *InHeader, input *SetAttrIn) (out
 	// Must call GetAttr(); the filesystem may override some of
 	// the changes we effect here.
 	fi, code := node.fsInode.GetAttr(f, &header.Context)
+	
 	if code.Ok() {
 		out = node.mount.fileInfoToAttr(fi, header.NodeId)
 	}

fuse/pathfs.go

@@ -566,7 +566,7 @@ func (me *pathInode) GetAttr(file File, context *Context) (fi *os.FileInfo, code
 		fi, code = file.GetAttr()
 	}
 
-	if file == nil || code == ENOSYS {
+	if file == nil || code == ENOSYS || code == EBADF {
 		fi, code = me.fs.GetAttr(me.GetPath(), context)
 	}
 
@@ -585,12 +585,12 @@ func (me *pathInode) Chmod(file File, perms uint32, context *Context) (code Stat
 	for _, f := range files {
 		// TODO - pass context
 		code = f.Chmod(perms)
-		if !code.Ok() {
-			break
+		if code.Ok() {
+			return
 		}
 	}
 
-	if len(files) == 0 || code == ENOSYS {
+	if len(files) == 0 || code == ENOSYS || code == EBADF {
 		code = me.fs.Chmod(me.GetPath(), perms, context)
 	}
 	return code
@@ -601,11 +601,11 @@ func (me *pathInode) Chown(file File, uid uint32, gid uint32, context *Context)
 	for _, f := range files {
 		// TODO - pass context
 		code = f.Chown(uid, gid)
-		if !code.Ok() {
-			break
+		if code.Ok() {
+			return code
 		}
 	}
-	if len(files) == 0 || code == ENOSYS {
+	if len(files) == 0 || code == ENOSYS || code == EBADF {
 		// TODO - can we get just FATTR_GID but not FATTR_UID ?
 		code = me.fs.Chown(me.GetPath(), uid, gid, context)
 	}
@@ -617,11 +617,11 @@ func (me *pathInode) Truncate(file File, size uint64, context *Context) (code St
 	for _, f := range files {
 		// TODO - pass context
 		code = f.Truncate(size)
-		if !code.Ok() {
-			break
+		if code.Ok() {
+			return code
 		}
 	}
-	if len(files) == 0 || code == ENOSYS {
+	if  len(files) == 0 || code == ENOSYS || code == EBADF {
 		code = me.fs.Truncate(me.GetPath(), size, context)
 	}
 	return code
@@ -632,11 +632,11 @@ func (me *pathInode) Utimens(file File, atime uint64, mtime uint64, context *Con
 	for _, f := range files {
 		// TODO - pass context
 		code = f.Utimens(atime, mtime)
-		if !code.Ok() {
-			break
+		if code.Ok() {
+			return code
 		}
 	}
-	if len(files) == 0 || code == ENOSYS {
+	if len(files) == 0 || code == ENOSYS || code == EBADF {
 		code = me.fs.Utimens(me.GetPath(), atime, mtime, context)
 	}
 	return code