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     vtMinSize=1
  60     if echo $fstype | grep -q '^xfs$'; then
  61         vtMinSize=16
  62     fi
  63
  64     if [ $size -lt $vtMinSize ]; then
  65         echo "size too small ($size)"
  66         exit 1
  67     fi
  68 else
  69     echo "Invalid size $size"
  70     exit 1
  71 fi
  72
  73
  74 # check file system type
  75 # nodiscard must be set for ext2/3/4
  76 # -K must be set for xfs
  77 if echo $fstype | grep -q '^ext[234]$'; then
  78     fsopt='-E nodiscard'
  79 elif [ "$fstype" = "xfs" ]; then
  80     fsopt='-K'
  81 else
  82     echo "unsupported file system $fstype"
  83     exit 1
  84 fi
  85
  86 if [ "$outputdir" != "persistence.dat" ]; then
  87     mkdir -p "$(dirname "$outputfile")"
  88 fi
  89
  90 # 00->ff avoid sparse file
  91 dd if=/dev/zero  bs=1M count=$size | tr '\000' '\377' > "$outputfile"
  92 sync
  93
  94 freeloop=$(losetup -f)
  95
  96 losetup $freeloop "$outputfile"
  97
  98 if [ ! -z "$passphrase" ]; then
  99     printf "$passphrase" | cryptsetup -q --verbose luksFormat $freeloop -
 100     printf "$passphrase" | cryptsetup -q --verbose luksOpen $freeloop persist_decrypted -
 101     _freeloop=$freeloop
 102     freeloop="/dev/mapper/persist_decrypted"
 103 fi
 104
 105 mkfs -t $fstype $fsopt -L $label $freeloop
 106
 107 sync
 108
 109 if [ -n "$config" ]; then
 110     if [ -d ./persist_tmp_mnt ]; then
 111         rm -rf ./persist_tmp_mnt
 112     fi
 113
 114     mkdir ./persist_tmp_mnt
 115     if mount $freeloop ./persist_tmp_mnt; then
 116         echo '/ union' > ./persist_tmp_mnt/$config
 117         sync
 118         umount ./persist_tmp_mnt
 119     fi
 120     rm -rf ./persist_tmp_mnt
 121 fi
 122
 123 if [ ! -z "$passphrase" ]; then
 124     cryptsetup luksClose $freeloop
 125     freeloop=$_freeloop
 126 fi
 127
 128 losetup -d $freeloop