diff --git a/internal/fusefs/syscallerr.go b/internal/fusefs/syscallerr.go
new file mode 100644
index 0000000..e055acb
--- /dev/null
+++ b/internal/fusefs/syscallerr.go
@@ -0,0 +1,67 @@
+package fusefs
+import (
+	"go.arsenm.dev/infinitime/blefs"
+	"syscall"
+)
+
+func syscallErr(err error) syscall.Errno {
+	if err == nil {
+		return 0
+	}
+
+	switch err {
+	case blefs.FSError{0x02}: // filesystem error
+		return syscall.EIO // TODO
+	case blefs.FSError{0x05}: // read-only filesystem
+		return syscall.EROFS
+	case blefs.FSError{0x03}: // no such file
+		return syscall.ENOENT
+	case blefs.FSError{0x04}: // protocol error
+		return syscall.EPROTO
+	case blefs.FSError{-5}: // input/output error
+		return syscall.EIO
+	case blefs.FSError{-84}: // filesystem is corrupted
+		return syscall.ENOTRECOVERABLE // TODO
+	case blefs.FSError{-2}: // no such directory entry
+		return syscall.ENOENT
+	case blefs.FSError{-17}: // entry already exists
+		return syscall.EEXIST
+	case blefs.FSError{-20}: // entry is not a directory
+		return syscall.ENOTDIR
+	case blefs.FSError{-39}: // directory is not empty
+		return syscall.ENOTEMPTY
+	case blefs.FSError{-9}: // bad file number
+		return syscall.EBADF
+	case blefs.FSError{-27}: // file is too large
+		return syscall.EFBIG
+	case blefs.FSError{-22}: // invalid parameter
+		return syscall.EINVAL
+	case blefs.FSError{-28}: // no space left on device
+		return syscall.ENOSPC
+	case blefs.FSError{-12}: // no more memory available
+		return syscall.ENOMEM
+	case blefs.FSError{-61}: // no attr available
+		return syscall.ENODATA // TODO
+	case blefs.FSError{-36}: // file name is too long
+		return syscall.ENAMETOOLONG
+	case blefs.ErrFileNotExists: // file does not exist
+		return syscall.ENOENT
+	case blefs.ErrFileReadOnly: // file is read only
+		return syscall.EACCES
+	case blefs.ErrFileWriteOnly: // file is write only
+		return syscall.EACCES
+	case blefs.ErrInvalidOffset: // invalid file offset
+		return syscall.EFAULT  // TODO
+	case blefs.ErrOffsetChanged: // offset has already been changed
+		return syscall.ESPIPE
+	case blefs.ErrReadOpen: // only one file can be opened for reading at a time
+		return syscall.ENFILE
+	case blefs.ErrWriteOpen: // only one file can be opened for writing at a time
+		return syscall.ENFILE
+	case blefs.ErrNoRemoveRoot: // refusing to remove root directory
+		return syscall.EPERM
+	}
+
+	return syscall.EIO // TODO
+
+}