De man e2fsck :
-C fd
This option causes e2fsck to write completion information to the specified file descriptor so that the progress of the filesystem check can be monitored. This option is typically used by programs which are running e2fsck. If the file descriptor number is negative, then absolute value of the file descriptor will be used, and the progress information will be suppressed initially. It can later be enabled by sending the e2fsck process a SIGUSR1 signal. If the file descriptor specified is 0, e2fsck will print a completion bar as it goes about its business. This requires that e2fsck is running on a video console or terminal.
Observe especialmente a linha em negrito e tente e2fsck -C 0 . Aparentemente, você pode até mesmo ativar a saída da barra de progresso depois de executar o programa, enviando o processo para o sinal certo!
pkill -SIGUSR1 e2fsck