Move unknown mountpoints before booting

If there are mountpoints outside of /root, which `run-init` does not
have in its whitelist, then `run-init` will refuse to boot and will
crash the kernel instead (process 1 will exit).

1 files changed, 14 insertions, 0 deletions

diff --git a/src/initrd/btrfs-create.sh b/src/initrd/btrfs-create.sh
index 567ad97..f47dfaf 100644
--- a/src/initrd/btrfs-create.sh
+++ b/src/initrd/btrfs-create.sh
@@ -71,6 +71,19 @@ init_samizdat()
   initialize_root_filesystem                       || return
 }
 
+movemounts()
+{
+    # Move mounted filesystems to the future root filesystem
+    while read dev mp rest; do
+        case "$mp" in
+            /root/*|/root|/|/proc|/dev|/dev/pts|/sys|/run) continue ;;
+            *) target=/root/$mp ;;
+        esac
+        mkdir -p "$target"
+        mount -n -o move "$mp" "$target"
+    done </proc/mounts
+}
+
 samizdat_movemounts()
 {
     local imgfile="$1" mountpoint
@@ -83,6 +96,7 @@ samizdat_movemounts()
     mkdir /root/cdrom
     mount -o move /cdrom /root/cdrom
     umount /plaintext
+    movemounts
     true
 }