pactools/pt-pacman-cage

   1 #!/bin/bash
   2 #
   3 #   pacman-cage
   4 #
   5 #   Copyright (c) 2002-2006 by Andrew Rose <rose.andrew@gmail.com>
   6 #   I used Judds pacman-optimise as a framework.
   7 #
   8 #   This program is free software; you can redistribute it and/or modify
   9 #   it under the terms of the GNU General Public License as published by
  10 #   the Free Software Foundation; either version 2 of the License, or
  11 #   (at your option) any later version.
  12 #
  13 #   This program is distributed in the hope that it will be useful,
  14 #   but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 #   GNU General Public License for more details.
  17 #
  18 #   You should have received a copy of the GNU General Public License
  19 #   along with this program; if not, write to the Free Software
  20 #   Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  21 #   USA.
  22 #
  23
  24 myver='2.9.8.1'
  25 dbroot="/var/lib/pacman"
  26 pacmandb="/var/lib/pacman.db"
  27
  28 usage() {
  29         echo "pacman-cage $myver"
  30         echo "usage: $0 pacman_db_size(MB)"
  31         echo
  32         echo "pacman-cage creates a loopbacked filesystem in a contigious file."
  33         echo "This will give better response times when using pacman"
  34         echo "A safe value for pacman_db_size should be > 40"
  35         echo
  36         echo "If you are unsure, use this:"
  37         echo " $0 60"
  38         echo
  39 }
  40
  41 die() {
  42         echo "pacman-cage: $*" >&2
  43         exit 1
  44 }
  45
  46 die_r() {
  47         rm -f /tmp/pacman.lck
  48         die $*
  49 }
  50
  51 loop_check=`zcat /proc/config.gz | grep CONFIG_BLK_DEV_LOOP | cut -d\= -f2`
  52
  53 if [ "$loop_check" == "m" ]; then
  54         if [ `lsmod | grep loop | cut -d\  -f1` != "loop" ]; then
  55                 echo "Error. You have to load the module 'loop' in rc.conf."
  56                 exit 1
  57         fi
  58 fi
  59
  60 if [ "$loop_check" == "CONFIG_BLK_DEV_LOOP" ]; then
  61         echo "Error. Your kernel config doesn't include CONFIG_BLK_DEV_LOOP."
  62         exit 1
  63 fi
  64
  65
  66 if [ "$#" != "1" ]; then echo "wrong number of parameters" 1>&2 ; usage; exit 0; fi
  67
  68 if [ "$1" != "" ]; then
  69         if [ "$1" = "-h" -o "$1" = "--help" ]; then
  70                 usage
  71                 exit 0
  72         fi
  73         dbsize=$1
  74 fi
  75
  76 if [ "`id -u`" != 0 ]; then
  77         die "You must be root to cage the database"
  78 fi
  79
  80 # make sure pacman isn't running
  81 if [ -f /tmp/pacman.lck ]; then
  82         die "Pacman lockfile was found.  Cannot run while pacman is running."
  83 fi
  84 # make sure pacman.db hasnt already been made
  85 if [ -f $pacmandb ]; then
  86         die "$pacmandb already exists!."
  87 fi
  88
  89 if [ ! -d $dbroot ]; then
  90         die "$dbroot does not exist or is not a directory"
  91 fi
  92
  93 # don't let pacman run while we do this
  94 touch /tmp/pacman.lck
  95
  96 # step 1: sum the old db
  97 echo "==> md5sum'ing the old database..."
  98 find $dbroot -type f | sort | xargs md5sum >/tmp/pacsums.old
  99
 100 echo "==> creating pacman.db loopback file..."
 101 dd if=/dev/zero of=$pacmandb bs=1M count=$dbsize > /dev/null 2>&1
 102
 103 echo "==> creating ext2 -O dir_index -b 1024 -m 0 on $pacmandb..."
 104 yes | mkfs.ext2 -O dir_index -b 1024 -i 1024 -m 0 -F $pacmandb > /dev/null 2>&1
 105
 106 echo "==> creating temporary mount point /mnt/tmp-pacman.."
 107 mkdir /mnt/tmp-pacman
 108
 109 echo "==> mounting pacman.db to temporary mount point..."
 110 mount -o loop $pacmandb /mnt/tmp-pacman
 111
 112 echo "==> copying pacman database to temporary mount point..."
 113 cp -a /var/lib/pacman/. /mnt/tmp-pacman
 114
 115 echo "==> unmounting temporary mount point..."
 116 umount /mnt/tmp-pacman
 117
 118 echo "==> removing temporary mount point..."
 119 rmdir /mnt/tmp-pacman
 120
 121 echo "==> moving old /var/lib/pacman to /var/lib/pacman.bak..."
 122 mv /var/lib/pacman /var/lib/pacman.bak
 123
 124 echo "==> createing new pacman db mount point @ $dbroot..."
 125 mkdir $dbroot
 126
 127 echo "==> Mounting new pacman db..."
 128 mount -o loop $pacmandb $dbroot
 129
 130 echo "==> md5sum'ing the new database..."
 131 find $dbroot -type f | sort | xargs md5sum >/tmp/pacsums.new
 132
 133 echo "==> checking integrity..."
 134 diff /tmp/pacsums.old /tmp/pacsums.new >/dev/null 2>&1
 135 if [ $? -ne 0 ]; then
 136         # failed, move the old one back into place
 137         umount $dbroot
 138         rm $pacmandb
 139         mv $dbroot.bak $dbroot
 140         die_r "integrity check FAILED, reverting to old database"
 141 fi
 142
 143 echo "==> Updating /etc/fstab to reflect changes..."
 144 echo "$pacmandb $dbroot ext2 loop,defaults 0 0" >> /etc/fstab
 145
 146 rm -f /tmp/pacman.lck /tmp/pacsums.old /tmp/pacsums.new
 147
 148 echo
 149 echo "Finished.  Your pacman database has been caged!.  May the speedy pacman be with you."
 150 echo
 151
 152 exit 0