cgofuse: refactor Gettattr

- Splits up the logic.
- Adds the new interfaces for time value getters.
- Accounts for active file handles.

internal/filesystem/cgofuse/stat.go

@@ -16,84 +16,40 @@ func (gw *goWrapper) Statfs(path string, stat *fuse.Statfs_t) int {
 
 func (gw *goWrapper) Getattr(path string, stat *fuse.Stat_t, fh uint64) int {
 	defer gw.systemLock.Access(path)()
-	goPath, err := fuseToGo(path)
-	if err != nil {
-		gw.log.Print(err)
-		// TODO: review; should we return the value raw or send err to a converter?
-		// ^ send a stacked err to a converter*
-		// (so that the trace contains both ops, parent-op+path-lexer+reason)
-		// TODO: re-read spec. This is the closest value that seemed appropriate
-		// but maybe ACCESS or NOENT makes more sense.
-		return -fuse.EINVAL
-	}
-
+	var (
+		info fs.FileInfo
+		err  error
+	)
 	if fh != errorHandle {
-		// TODO: fh lookup
+		info, err = gw.infoFromHandle(fh)
+	} else {
+		info, err = gw.infoFromPath(path)
 	}
-
-	// TODO: review
-	goStat, err := fs.Stat(gw.FS, goPath)
 	if err != nil {
-		errNo := interpretError(err)
-		// Don't flood the logs with "not found" errors.
-		if errNo != -fuse.ENOENT {
-			// TODO: [DBG] reduce this format
-			gw.log.Printf("path: %s\ngoPath: %s\nerr:%s", path, goPath, err)
-		}
-		return errNo
+		return interpretError(err)
 	}
-
-	// fsys.log.Printf("stat for %s\n%#v", path, goStat)
-
-	// TODO: don't change stat on the fuse object
-	// push changes back to fs.FS via extension
-	// fs.SetAttr, fs.SetAttrFuse(path, someOverlappingAttrType)
-
-	mTime := fuse.NewTimespec(goStat.ModTime())
-
-	// TODO: The fallback should be (optionally) set within the wrapper's constructor.
-	// Which itself should have a read-only default like this if not provided.
-	const fallbackPermissions = readAll | executeAll
 	var (
-		goMode          = goStat.Mode()
-		fuseType        = goToFuseFileType(goMode)
-		fusePermissions uint32
+		uid, gid, _ = fuse.Getcontext()
+		fctx        = fuseContext{uid: uid, gid: gid}
 	)
-	if goPermissions := goMode.Perm(); goPermissions != 0 {
-		fusePermissions = goToFusePermissions(goPermissions)
-	} else {
-		fusePermissions = fallbackPermissions
-	}
-	stat.Uid, stat.Gid, _ = fuse.Getcontext()
-	stat.Mode = fuseType | fusePermissions
-	stat.Size = goStat.Size()
-	// TODO: block size
-
-	// TODO: [devel] `File` needs extensions for these times and we should use them conditionally
-	// something like `if aTimer ok; stat.Atim = aTimer.Time()`
-	// For now we cheat and use the same value for all
-	stat.Atim, // XXX: This shouldn't even be legal syntax.
-		stat.Mtim,
-		stat.Ctim,
-		stat.Birthtim = mTime,
-		mTime,
-		mTime,
-		mTime
+	goToFuseStat(info, fctx, stat)
+	return operationSuccess
+}
 
-	/*
-		if path != "/" {
-			log.Printf("%s - mode pre conversion: %d, %s",
-				path,
-				goStat.Mode(), goStat.Mode())
-			log.Printf("%s - mode post conversion (masked): %d %d|%d",
-				path,
-				stat.Mode,
-				stat.Mode&fuselib.S_IFMT, stat.Mode&^fuselib.S_IFMT,
-			)
-		}
-	*/
+func (gw *goWrapper) infoFromHandle(fh uint64) (fs.FileInfo, error) {
+	file, err := gw.fileTable.get(fh)
+	if err != nil {
+		return nil, err
+	}
+	return file.goFile.Stat()
+}
 
-	return operationSuccess
+func (gw *goWrapper) infoFromPath(path string) (fs.FileInfo, error) {
+	goPath, err := fuseToGo(path)
+	if err != nil {
+		return nil, err
+	}
+	return fs.Stat(gw.FS, goPath)
 }
 
 func (gw *goWrapper) Utimens(path string, tmsp []fuse.Timespec) int {

internal/filesystem/cgofuse/translate.go

@@ -67,6 +67,39 @@ func fuseToGo(path string) (string, error) {
 	return path[1:], nil
 }
 
+func goToFuseStat(info fs.FileInfo, fctx fuseContext, stat *fuse.Stat_t) {
+	var (
+		goMode          = info.Mode()
+		fuseType        = goToFuseFileType(goMode)
+		fusePermissions uint32
+	)
+	if goPermissions := goMode.Perm(); goPermissions != 0 {
+		fusePermissions = goToFusePermissions(goPermissions)
+	} else {
+		// TODO: The fallback should be (optionally) set within the wrapper's constructor.
+		// Which itself should have a read-only default like this if not provided.
+		const fallbackPermissions = readAll | executeAll
+		fusePermissions = fallbackPermissions
+	}
+
+	stat.Mode = fuseType | fusePermissions
+	stat.Uid = fctx.uid
+	stat.Gid = fctx.gid
+	stat.Size = info.Size()
+
+	if atimer, ok := info.(filesystem.AccessTimer); ok {
+		stat.Atim = fuse.NewTimespec(atimer.AccessTime())
+	}
+	stat.Mtim = fuse.NewTimespec(info.ModTime())
+	if ctimer, ok := info.(filesystem.ChangeTimer); ok {
+		stat.Ctim = fuse.NewTimespec(ctimer.ChangeTime())
+	}
+	// TODO: Block size + others.
+	if crtimer, ok := info.(filesystem.CreationTimer); ok {
+		stat.Birthtim = fuse.NewTimespec(crtimer.CreationTime())
+	}
+}
+
 // [FileMode] to FUSE mode bits.
 func goToFuseFileType(m fs.FileMode) fileType {
 	switch m.Type() {