Force systems with kernel option "quiet" to display prompt for password

On systems that utilize TTY for password entry, if the kernel option "quiet" is set, the system would appear to freeze on a blank screen, when in fact it is waiting for password entry from the user. Since TTY is the fallback method, this has no effect on systemd or plymouth password prompting. By temporarily setting "printk" to "7", running the command, then resuming with the original "printk" state, the user can see the password prompt. Reviewed-by: Richard Laager <[email protected]> Reviewed-by: Brian Behlendorf <[email protected]> Signed-off-by: Garrett Fields <[email protected]> Closes openzfs#9731
ryao · Dec 18, 2019 · e8b199f · e8b199f
1 parent ad97643
commit e8b199f
Showing 1 changed file with 4 additions and 0 deletions.
diff --git a/contrib/initramfs/scripts/zfs.in b/contrib/initramfs/scripts/zfs.in
@@ -436,7 +436,11 @@ decrypt_fs()
 
 			# Prompt with ZFS tty, otherwise
 			else
+				# Setting "printk" temporarily to "7" will allow prompt even if kernel option "quiet"
+				storeprintk="$(awk '{print $1}' /proc/sys/kernel/printk)"
+				echo 7 > /proc/sys/kernel/printk
 				$ZFS load-key "${ENCRYPTIONROOT}"
+				echo "$storeprintk" > /proc/sys/kernel/printk
 			fi
 		fi
 	fi