grub + cryptsetup not booting after kernel update

Well, it seems that I shot myself in the foot. I compiled cryptsetup 1.6.1 from a tar-ball in the official repo. I built it with checkinstall. What I never suspected is that my nice little thing does not provide the appropriate hooks for initramfs-tools, which you can find in:

/usr/share/initramfs-tools/hooks/
(credits to:
Initramfs - Ubuntu Wiki
https://wiki.ubuntu.com/Initramfs )

I haven't tested the solution, but I uninstalled my own cryptsetup package (which I donate under the advice of not using it very much) and re-installed the version in the repos. It automatically created the executables in the mentioned directory above.

Also, I managed to load the dm-crypt, aes and xts modules into my image by modifying /etc/initramfs-tools/modules
(inspiration from
Custom kernel, encrypt hook not working... help. [SOLVED]
https://bbs.archlinux.org/viewtopic.php?id=157246:)
echo -e "crypto\nxts\ndm-crypt\naes" >> /etc/initramfs-tools/modules

Which I think is not really needed after installing the official cryptsetup, but I think it would be useful for someone trying to debug their own initrd.img

Now, I will restart my computer, and see if it works! Wish me luck.

[ UPDATE-1: DOES NOT WORK ]
It didn't work. I got to busybox, and now I had cryptsetup. After doing a cat /proc/modules, I saw dm_crypt

If someone would be so kind in telling me how to add the required things to my deb package or modify the current package to update it to version 1.6, I would appreciate it.

[UPDATE-2: slightly easier way to get chroot; just copy-paste to a file (or download chroot.sh and make executable]
#!/bin/bash
# Script made for Trisquel to chroot to a LVM on top of a LUKS using cryptsetup
# requires access to repositories with aptitude, cryptsetup and lvm2

# If you run this like ./chroot.sh m it's because you already unlocked the encrypted partition and know the name of the lvm volume of the boot partition

# Skip if the first argument given to chroot is "m"
if [[ "$1" != "m" ]]; then
echo "We are going to ask for all the data";
# Make sure that aptitude, cryptsetup and lvm2 are installed
[[ -z $(which aptitude) ]] && apt-get update && apt-get install aptitude;
[[ -z $(which vgscan) || -z $(which cryptsetup) ]] && aptitude install -y lvm2 cryptsetup;
# Load required modules (dm-crypt, aes, xts)
for i in {dm-crypt,aes,xts}; do
modprobe "$i";
done;

# Print name of current (un-encrypted) partitions
blkid | awk '{print $1}' | tr -d ':';
echo "Type the name of your encrypted partition (/dev/sdxY) ";
read encpart;
# Open the partition
cryptsetup luksOpen "$encpart" root;
# Make sure that lvm2 is installed
for lvgr in "$(vgscan | sed -n '/group/{s-.*group "\([^"]*\)".*-\1-g;p}')"; do
vgchange -a y all "$lvgr";
for lvdev in "$(lvscan | awk '{print $2}' | tr -d "'")"; do
list_lvm="$(printf "%s\n%s\n" $list_lvm $lvdev; printf "\n")";
done;
done;
echo -e "$list_lvm\nType the name of your root LVM partition from the list above (/dev/group/part) "
read rootpart;
echo -e "Type the name of your boot partition, if any (/dev/sdxY or /dev/group/part) ";
read bootpart;
fi;

if [[ "$1" == "m" ]]; then
rootpart="$2";
bootpart="$3";
fi;

# Mount $rootpart, $bootpart, dev, proc, sys, devpts, run
mount "$rootpart" /mnt && ([[ -n "$bootpart" ]] && mount "$bootpart" /mnt/boot) || mount -o bind /dev /mnt/dev; mount -t proc /proc /mnt/proc ; mount -t sysfs /sys /mnt/sys; mount -t devpts /dev/pts /mnt/dev/pts; mount -o bind /run /mnt/run; # [UPDATE-3: added run and dev/pts to the mounts]
echo "Ready to chroot";

chroot /mnt;

echo "Closed chroot, unmounting";
# Unmount everything
for i in {proc,sys,dev/pts,dev,boot,run,""}; do
umount /mnt/"$i";
done;

I cannot really help you (I have never used an encrypted partition) but I would like to know why you chose not to use the package shipped by Trisquel. Is it unsafe for some reason?

What happened when you ran update-grub? Once you had mounted everything, but before chroot, does blkid show the encrypted partition mounted ("/dev/mapper/Lap-root")?

It is unclear to me if your problem is solved or not?

If your problem is not solved, then don't panic...

I would recommend you to go the safe way:

If you have not damaged your encrypted partition, you should be safe. The boot loader is not on the encrypted partition. As I read your post, you haven't done anything bad with the encrypted partition. So that is good.

So, if you have another PC you can just take out your harddisk and mount it in another Trisquel-PC and boot with the working Trisquel. You should be able to unlock the drive on the other system and then you can make a backup of all your important stuff to a safe location. After that you can just put it back in your old PC and do a complete reinstallation of Trisquel - and learn from your mistake:)

Well, I restarted, did the cat /proc/modules again in busybox, and dm_crypt is not there. It is in my initrd.img file (zcat /boot/initrd.img | cpio -t)

Lessons to be learnt:
1) initramfs is in charge of loading modules, scripts and hooks into the initrd.img files. These are files containing the kernel.
2) if you get to busybox because your kernel was not loaded, don't panic, you just probably only need the appropriate modules, scripts and hooks (check How to solve boot problems with Ubuntu after kernel upgrade: www.dedoimedo.com/computers/ubuntu-initrd-bug.html).
3) you need to do a chroot environment with the required modules and decrypting your dm-crypt or LUKS partition (https://trisquel.info/en/forum/grub-cryptsetup-not-booting-after-kernel-update#comment-40597)
4) just to make sure, purge cryptsetup (aptitude purge cryptsetup cryptsetup-bin libcryptsetup4) and reinstall (aptitude install cryptsetup cryptsetup-bin+M libcryptsetup4+M)
5) just to make sure, try installing another kernel or purge and reinstall the one you have now (I'm not giving instructions for this in case you are a newbie, and want to take it easy, but if you really dare use aptitude search '~ilinux' --disable-columns -F '%p' | grep `image\|headers' to see which ones are installed)
6) use the name for the current unencrypted partition (I used "root" in step 3: cryptsetup luksOpen "$encpart" root) and modify your /etc/crypttab so that it says something like (le'ts say I used root):
root UUID=«uuid of your encrypted partition» none luks

(to get the UUID you can type blkid). You are free to check the man-pages of crypttab: man crypttab
7) make sure that you have an according entry in /etc/fstab
/dev/mapper/root «path to mount it» «type» «options» 0 1

«path to mount it», «type» and «options»: are usually already there, but if not, you need to know how you formatted and where installed the system in the first place. You are also free to check the man-pages of mount and fstab: man fstab && man mount.
8-optional) you can try to see if it is possible that the thing will work by installing qemu:
sudo qemu-system-x86_64 -hda /dev/sda -vnc :0 &
sudo vncviewer localhost

You will get a GUI showing the booting process of your computer. It may not have the nice looks of the original, but if it works to the point of asking you for your password again, you are probably fine.

If you still get to busybox (initramfs) shell, then you can avoid restarting if you unencrypt manually (see https://trisquel.info/en/forum/grub-cryptsetup-not-booting-after-kernel-update#comment-40635)

Thanks to BlinkingArrow (https://trisquel.info/en/users/blinkingarrow) and Liberty (https://trisquel.info/en/users/liberty).