Implement encrypted cdrom ejection

This allows the cdrom to be copied onto the outer filesystem (mounted in
/outerfs) without storing unencrypted gpg keys there.

e.g.:

  samizdat-eject.sh /outerfs/samizdat.iso

This was necessary because the other method probably causes btrfs deadlocks.

We do end up copying data twice this way (or three times, probably --
if the ISO is saved), but not _from the cdrom_.  And we get to eject
immediately after the first copy.  Future copies will be from the hard
drive.  Not too bad.

1 files changed, 25 insertions, 1 deletions

diff --git a/old-school/lvm-create.sh b/old-school/lvm-create.sh
index ce0862e..916b888 100644
--- a/old-school/lvm-create.sh
+++ b/old-school/lvm-create.sh
@@ -53,12 +53,35 @@ init_samizdat()
 
   btrfs device add "$blockdev" /root || return
   mount -o rw,remount /root || return
+  samizdat_movemounts "$imgfile"
 
   initialize_root_filesystem || return
 
   bootdone root-mounted
 }
 
+samizdat_movemounts()
+{
+    local imgfile="$1" mountpoint
+
+    mountpoint=$(mountpoint_of "$imgfile") || return
+    mkdir /root/cdrom /root/outerfs
+    mount -o move /cdrom /root/cdrom
+    mount -o move "$mountpoint" /root/outerfs
+    mkdir /run/initramfs/samizdat
+    mv /var/log /run/initramfs/samizdat/log
+}
+
+mountpoint_of()
+{
+    local f="$1"
+    while ! mountpoint -q "$f"; do
+        f=$(dirname "$f")
+        [ "$f" != '.' ] || return 1
+    done
+    printf '%s\n' "$f"
+}
+
 initialize_root_filesystem()
 {
     rm -r /root/root
@@ -117,7 +140,7 @@ filesystem_incomplete()
 open_samizdat()
 {
   open_samizdat_blockdev "$@" || return
-  local blockdev=/dev/mapper/samizdatcrypt fs
+  local blockdev=/dev/mapper/samizdatcrypt imgfile="$1" fs
 
   # For this part, we don't necessarily need the cdrom.
   # Unfortunately the init_gpg code is still getting the GPG key there.
@@ -127,6 +150,7 @@ open_samizdat()
   modprobe btrfs || return
   btrfs device scan || return
   mount -t btrfs -o subvol=ROOT "$blockdev" /root || return
+  samizdat_movemounts "$imgfile"
   LoSetup -D
   bootdone root-mounted
 }