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 while [ -n "$1" ]; do
  22     if [ "$1" = "-s" ]; then
  23         shift
  24         size=$1
  25     elif [ "$1" = "-t" ]; then
  26         shift
  27         fstype=$1
  28     elif [ "$1" = "-l" ]; then
  29         shift
  30         label=$1
  31     elif [ "$1" = "-c" ]; then
  32         shift
  33         config=$1
  34     elif [ "$1" = "-o" ]; then
  35         shift
  36         outputfile=$1
  37     elif [ "$1" = "-e" ]; then
  38         read -s -p "Encryption passphrase: " passphrase
  39         echo
  40     elif [ "$1" = "-h" ] || [ "$1" = "--help" ]; then
  41         print_usage
  42         exit 0
  43     else
  44         print_usage
  45         exit 1
  46     fi
  47     shift
  48 done
  49
  50
  51 # check label
  52 if [ -z "$label" ]; then
  53     echo "The label can NOT be empty."
  54     exit 1
  55 fi
  56
  57 # check size
  58 if echo $size | grep -q "^[0-9][0-9]*$"; then
  59     if [ $size -le 1 ]; then
  60         echo "Invalid size $size"
  61         exit 1
  62     fi
  63 else
  64     echo "Invalid size $size"
  65     exit 1
  66 fi
  67
  68
  69 # check file system type
  70 # nodiscard must be set for ext2/3/4
  71 # -K must be set for xfs
  72 if echo $fstype | grep -q '^ext[234]$'; then
  73     fsopt='-E nodiscard'
  74 elif [ "$fstype" = "xfs" ]; then
  75     fsopt='-K'
  76 else
  77     echo "unsupported file system $fstype"
  78     exit 1
  79 fi
  80
  81 if [ "$outputdir" != "persistence.dat" ]; then
  82     mkdir -p "$(dirname "$outputfile")"
  83 fi
  84
  85 # 00->ff avoid sparse file
  86 dd if=/dev/zero  bs=1M count=$size | tr '\000' '\377' > "$outputfile"
  87 sync
  88
  89 freeloop=$(losetup -f)
  90
  91 losetup $freeloop "$outputfile"
  92
  93 if [ ! -z "$passphrase" ]; then
  94     printf "$passphrase" | cryptsetup -q --verbose luksFormat $freeloop -
  95     printf "$passphrase" | cryptsetup -q --verbose luksOpen $freeloop persist_decrypted -
  96     _freeloop=$freeloop
  97     freeloop="/dev/mapper/persist_decrypted"
  98 fi
  99
 100 mkfs -t $fstype $fsopt -L $label $freeloop
 101
 102 sync
 103
 104 if [ -n "$config" ]; then
 105     if [ -d ./persist_tmp_mnt ]; then
 106         rm -rf ./persist_tmp_mnt
 107     fi
 108
 109     mkdir ./persist_tmp_mnt
 110     if mount $freeloop ./persist_tmp_mnt; then
 111         echo '/ union' > ./persist_tmp_mnt/$config
 112         sync
 113         umount ./persist_tmp_mnt
 114     fi
 115     rm -rf ./persist_tmp_mnt
 116 fi
 117
 118 if [ ! -z "$passphrase" ]; then
 119     cryptsetup luksClose $freeloop
 120     freeloop=$_freeloop
 121 fi
 122
 123 losetup -d $freeloop