cryptsetup refuses to luksFormat?

[Josef Wolf]

On Sat, Oct 21, 2023 at 08:10:43PM +0200, Josef Wolf wrote:
> Uh! It gets even more strange:
> 
>   # mount -o remount,ro /boot
>   # install -m0600 /dev/null /tmp/boot.tar
>   # tar -C /boot --acls --xattrs --one-file-system -cf /tmp/boot.tar .
>   # umount /boot/efi
>   # umount /boot
>   # mount /boot
>   mount: /boot: /dev/nvme0n1p3 already mounted or mount point busy
> 
> and again: no sign that the partition is in use:
> 
>   # grep nvme0n1p3 /proc/mounts
>   # lsof | grep nvme0n1p3
>   # lsof nvme0n1p3
>   # fuser nvme0n1p3

Coming closer:

   # mount -o remount,ro /boot
   # install -m0600 /dev/null /tmp/boot.tar
   # tar -C /boot --acls --xattrs --one-file-system -cf /tmp/boot.tar .
   # umount /boot/efi
   # mount -o remount,rw /boot    # <<<<------- notice this one!
   # umount /boot
   # mount /boot                  # <<<<------- Now it succeeds!


   # mount -o remount,ro /boot
   # install -m0600 /dev/null /tmp/boot.tar
   # tar -C /boot --acls --xattrs --one-file-system -cf /tmp/boot.tar .
   # umount /boot/efi
   # umount /boot
   # mount /boot
   mount: /boot: /dev/nvme0n1p3 already mounted or mount point busy

Partition originally was mounted read-write. umount while remounted read-only seems to
mess up things and mount looses track of was was going on..

-- 
Josef Wolf
jw at raven.inka.de