Manjaro partition won't boot, etc dir missing

Hi,

I updated my nvidia drivers at the end of last week and yesterday couldn’t boot into manjaro. At the time I didn’t know the nvidia updates were bad for some people, so just went searching the web for solutions, and ended up chrooting from ubuntu into manjaro and running pacman -Syu, pacman -S udev , and pacman -Sy linux. I am not entirely sure what those commands did, yes I know I should have done my research. I certainly will next time.

This is when the problems really started. After that it seems like grub broke because I couldn’t see any boot options on startup. So I chroot into ubuntu from live usb and reinstall grub, and then I can boot into ubuntu. However when I mount manjaro to ubuntu it’s really screwed up. The entire etc dir is missing. /bin/bash is gone so when I chroot I have to use sbin's bash. Lots of other stuff missing as well. Needless to say I cannot boot into manjaro.

Is it worth trying to save this partition? Can anything be done to restore some of the directories and files that appear to be missing? And what did I do wrong?

Other details:

  • EFI desktop machine
  • My mounting procedure:

mount /dev/sda6 /mnt
mount /dev/sda1 /mnt/boot/efi
mount -t proc /proc /mnt/proc
mount --rbind /sys /mnt/sys
mount --rbind /dev /mnt/dev
mount --rbind /dev/pts /mnt/dev/pts

side question: when trying to umount dev and sys they always say they are busy. Is it ok to reboot while they are still mounted?