dracut-initramfs-restore.sh

   1 #!/bin/bash
   2
   3 set -e
   4
   5 # do some sanity checks first
   6 [ -e /run/initramfs/bin/sh ] && exit 0
   7 [ -e /run/initramfs/.need_shutdown ] || exit 0
   8
   9 # SIGTERM signal is received upon forced shutdown: ignore the signal
  10 # We want to remain alive to be able to trap unpacking errors to avoid
  11 # switching root to an incompletely unpacked initramfs
  12 trap 'echo "Received SIGTERM signal, ignoring!" >&2' TERM
  13
  14 KERNEL_VERSION="$(uname -r)"
  15
  16 [[ $dracutbasedir ]] || dracutbasedir=/usr/lib/dracut
  17 SKIP="$dracutbasedir/skipcpio"
  18 [[ -x $SKIP ]] || SKIP="cat"
  19
  20 if [[ -d /efi/Default ]] || [[ -d /boot/Default ]] || [[ -d /boot/efi/Default ]]; then
  21     MACHINE_ID="Default"
  22 elif [[ -s /etc/machine-id ]]; then
  23     read -r MACHINE_ID < /etc/machine-id
  24     [[ $MACHINE_ID == "uninitialized" ]] && MACHINE_ID="Default"
  25 else
  26     MACHINE_ID="Default"
  27 fi
  28
  29 mount -o ro /boot &> /dev/null || true
  30
  31 if [[ -d /efi/loader/entries || -L /efi/loader/entries ]] \
  32     && [[ -d /efi/$MACHINE_ID || -L /efi/$MACHINE_ID ]]; then
  33     IMG="/efi/${MACHINE_ID}/${KERNEL_VERSION}/initrd"
  34 elif [[ -d /boot/loader/entries || -L /boot/loader/entries ]] \
  35     && [[ -d /boot/$MACHINE_ID || -L /boot/$MACHINE_ID ]]; then
  36     IMG="/boot/${MACHINE_ID}/${KERNEL_VERSION}/initrd"
  37 elif [[ -d /boot/efi/loader/entries || -L /boot/efi/loader/entries ]] \
  38     && [[ -d /boot/efi/$MACHINE_ID || -L /boot/efi/$MACHINE_ID ]]; then
  39     IMG="/boot/efi/$MACHINE_ID/$KERNEL_VERSION/initrd"
  40 elif [[ -f /lib/modules/${KERNEL_VERSION}/initrd ]]; then
  41     IMG="/lib/modules/${KERNEL_VERSION}/initrd"
  42 elif [[ -f /boot/initramfs-${KERNEL_VERSION}.img ]]; then
  43     IMG="/boot/initramfs-${KERNEL_VERSION}.img"
  44 elif mountpoint -q /efi; then
  45     IMG="/efi/$MACHINE_ID/$KERNEL_VERSION/initrd"
  46 elif mountpoint -q /boot/efi; then
  47     IMG="/boot/efi/$MACHINE_ID/$KERNEL_VERSION/initrd"
  48 else
  49     echo "No initramfs image found to restore!"
  50     exit 1
  51 fi
  52
  53 cd /run/initramfs
  54
  55 if (command -v zcat > /dev/null && $SKIP "$IMG" 2> /dev/null | zcat 2> /dev/null | cpio -id --no-absolute-filenames --quiet > /dev/null 2>&1) \
  56     || (command -v bzcat > /dev/null && $SKIP "$IMG" 2> /dev/null | bzcat 2> /dev/null | cpio -id --no-absolute-filenames --quiet > /dev/null 2>&1) \
  57     || (command -v xzcat > /dev/null && $SKIP "$IMG" 2> /dev/null | xzcat 2> /dev/null | cpio -id --no-absolute-filenames --quiet > /dev/null 2>&1) \
  58     || (command -v lz4 > /dev/null && $SKIP "$IMG" 2> /dev/null | lz4 -d -c 2> /dev/null | cpio -id --no-absolute-filenames --quiet > /dev/null 2>&1) \
  59     || (command -v lzop > /dev/null && $SKIP "$IMG" 2> /dev/null | lzop -d -c 2> /dev/null | cpio -id --no-absolute-filenames --quiet > /dev/null 2>&1) \
  60     || (command -v zstd > /dev/null && $SKIP "$IMG" 2> /dev/null | zstd -d -c 2> /dev/null | cpio -id --no-absolute-filenames --quiet > /dev/null 2>&1) \
  61     || ($SKIP "$IMG" 2> /dev/null | cpio -id --no-absolute-filenames --quiet > /dev/null 2>&1); then
  62     rm -f -- .need_shutdown
  63 else
  64     # something failed, so we clean up
  65     echo "Unpacking of $IMG to /run/initramfs failed" >&2
  66     rm -f -- /run/initramfs/shutdown
  67     exit 1
  68 fi
  69
  70 if [[ -d squash ]]; then
  71     if ! unsquashfs -no-xattrs -f -d . squash-root.img > /dev/null; then
  72         echo "Squash module is enabled for this initramfs but failed to unpack squash-root.img" >&2
  73         rm -f -- /run/initramfs/shutdown
  74         exit 1
  75     fi
  76 fi
  77
  78 if grep -q -w selinux /sys/kernel/security/lsm 2> /dev/null \
  79     && [ -e /etc/selinux/config -a -x /usr/sbin/setfiles ]; then
  80     . /etc/selinux/config
  81     if [[ $SELINUX != "disabled" && -n $SELINUXTYPE ]]; then
  82         /usr/sbin/setfiles -v -r /run/initramfs /etc/selinux/"${SELINUXTYPE}"/contexts/files/file_contexts /run/initramfs > /dev/null
  83     fi
  84 fi
  85
  86 exit 0