move inode to path lookup outside of open by id

examples/inodestat/main.go

@@ -32,16 +32,23 @@ func main() {
 		log.Fatalln("error parsing inode:", err)
 	}
 
-	f, err := scoutfs.OpenByID(dirf, u, os.O_RDONLY)
+	name, err := scoutfs.InoToPath(dirf, u)
+	if err != nil {
+		log.Fatalln("error getting pathname:", err)
+	}
+
+	f, err := scoutfs.OpenByID(dirf, u, os.O_RDONLY, name)
 	if err != nil {
 		log.Fatalln("error open by id:", err)
 	}
+	defer f.Close()
 
 	fi, err := f.Stat()
 	if err != nil {
 		log.Fatalln("error stat:", err)
 	}
 
+	fmt.Println("Full name relative to mount:", name)
 	fmt.Println("Name:", fi.Name())
 	fmt.Println("Size:", fi.Size())
 	fmt.Println("Mode:", fi.Mode())

scoutfs.go

@@ -181,14 +181,9 @@ func InoToPath(dirfd *os.File, ino uint64) (string, error) {
 // OpenByID will open a file by inode returning a typical *os.File
 // An open file within scoutfs is supplied for ioctls
 // (usually just the base mount point directory)
-// The filename is available through the *os.File and is populated with
-// the scoutfs InoToPath
-func OpenByID(dirfd *os.File, ino uint64, flags int) (*os.File, error) {
-	name, err := InoToPath(dirfd, ino)
-	if err != nil {
-		return nil, err
-	}
-
+// The filename supplied is used for the *os.File info, but can be "" if
+// not known or needed
+func OpenByID(dirfd *os.File, ino uint64, flags int, name string) (*os.File, error) {
 	fd, err := OpenByHandle(dirfd, ino, flags)
 	if err != nil {
 		return nil, err