INSTALL/CreatePersistentImg.sh

   1 #!/bin/bash
   2
   3 size=1024
   4 fstype=ext4
   5 label=casper-rw
   6 config=''
   7 outputfile=persistence.dat
   8
   9 print_usage() {
  10     echo 'Usage:  sudo ./CreatePersistentImg.sh [ -s size ] [ -t fstype ] [ -l LABEL ] [ -c CFG ] [ -e ]'
  11     echo '  OPTION: (optional)'
  12     echo '   -s size in MB, default is 1024'
  13     echo '   -t filesystem type, default is ext4  ext2/ext3/ext4/xfs are supported now'
  14     echo '   -l label, default is casper-rw'
  15     echo '   -c configfile name inside the persistence file. File content is "/ union"'
  16     echo '   -o outputfile name, default is persistence.dat'
  17     echo '   -e enable encryption, disabled by default (only few distros support this)'
  18     echo ''
  19 }
  20
  21 print_err() {
  22     echo ""
  23     echo "$*"
  24     echo ""
  25 }
  26
  27 uid=$(id -u)
  28 if [ $uid -ne 0 ]; then
  29     print_err "Please use sudo or run the script as root."
  30     exit 1
  31 fi
  32
  33 while [ -n "$1" ]; do
  34     if [ "$1" = "-s" ]; then
  35         shift
  36         size=$1
  37     elif [ "$1" = "-t" ]; then
  38         shift
  39         fstype=$1
  40     elif [ "$1" = "-l" ]; then
  41         shift
  42         label=$1
  43     elif [ "$1" = "-c" ]; then
  44         shift
  45         config=$1
  46     elif [ "$1" = "-o" ]; then
  47         shift
  48         outputfile=$1
  49     elif [ "$1" = "-e" ]; then
  50         read -s -p "Encryption passphrase: " passphrase
  51         echo
  52     elif [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
  53         print_usage
  54         exit 0
  55     else
  56         print_usage
  57         exit 1
  58     fi
  59     shift
  60 done
  61
  62
  63 # check label
  64 if [ -z "$label" ]; then
  65     echo "The label can NOT be empty."
  66     exit 1
  67 fi
  68
  69 # check size
  70 if echo $size | grep -q "^[0-9][0-9]*$"; then
  71     vtMinSize=1
  72     if echo $fstype | grep -q '^xfs$'; then
  73         vtMinSize=16
  74     fi
  75
  76     if [ $size -lt $vtMinSize ]; then
  77         echo "size too small ($size)"
  78         exit 1
  79     fi
  80 else
  81     echo "Invalid size $size"
  82     exit 1
  83 fi
  84
  85
  86 # check file system type
  87 # nodiscard must be set for ext2/3/4
  88 # -K must be set for xfs
  89 if echo $fstype | grep -q '^ext[234]$'; then
  90     fsopt='-E nodiscard'
  91 elif [ "$fstype" = "xfs" ]; then
  92     fsopt='-K'
  93 else
  94     echo "unsupported file system $fstype"
  95     exit 1
  96 fi
  97
  98 if [ "$outputdir" != "persistence.dat" ]; then
  99     mkdir -p "$(dirname "$outputfile")"
 100 fi
 101
 102 # 00->ff avoid sparse file
 103 dd if=/dev/zero  bs=1M count=$size | tr '\000' '\377' > "$outputfile"
 104 sync
 105
 106 freeloop=$(losetup -f)
 107
 108 losetup $freeloop "$outputfile"
 109
 110 if [ ! -z "$passphrase" ]; then
 111     printf "$passphrase" | cryptsetup -q --verbose luksFormat $freeloop -
 112     printf "$passphrase" | cryptsetup -q --verbose luksOpen $freeloop persist_decrypted -
 113     _freeloop=$freeloop
 114     freeloop="/dev/mapper/persist_decrypted"
 115 fi
 116
 117 mkfs -t $fstype $fsopt -L $label $freeloop
 118
 119 sync
 120
 121 if [ -n "$config" ]; then
 122     if [ -d ./persist_tmp_mnt ]; then
 123         rm -rf ./persist_tmp_mnt
 124     fi
 125
 126     mkdir ./persist_tmp_mnt
 127     if mount $freeloop ./persist_tmp_mnt; then
 128         echo '/ union' > ./persist_tmp_mnt/$config
 129         sync
 130         umount ./persist_tmp_mnt
 131     fi
 132     rm -rf ./persist_tmp_mnt
 133 fi
 134
 135 if [ ! -z "$passphrase" ]; then
 136     cryptsetup luksClose $freeloop
 137     freeloop=$_freeloop
 138 fi
 139
 140 losetup -d $freeloop