scripts/casper

   1 #!/bin/sh
   2
   3 # set -e
   4
   5 export PATH=/root/usr/bin:/root/usr/sbin:/root/bin:/root/sbin:/usr/bin:/usr/sbin:/bin:/sbin
   6
   7 mountpoint=/live_media
   8
   9 # Will be mounted if found as copy on write instead of tmpfs
  10 root_persistence="casper-rw"
  11
  12 # TODO
  13 ## Each file found with this pattern will be mounted directly in the
  14 ## mountpoint extracted from file name "${other_mounts_pattern}<mountpoint>"
  15 #other_mounts_pattern="casper-mount-"
  16 home_persistence="home-rw"
  17
  18 #overlay_method=unionfs
  19 #if [ "${DPKG_ARCH}" = "ia64" ] || [ "${DPKG_ARCH}" = "hppa" ] || [ "${DPKG_ARCH}" = "sparc" ]; then
  20 #    overlay_method=devmapper
  21 #fi
  22
  23 USERNAME="casper"
  24 USERFULLNAME="Live session user"
  25 HOST="live"
  26 BUILD_SYSTEM="Debian"
  27
  28 mkdir -p $mountpoint
  29
  30 [ -f /etc/casper.conf ] && . /etc/casper.conf
  31
  32 export USERNAME USERFULLNAME HOST BUILD_SYSTEM
  33
  34 if [ "${BUILD_SYSTEM}" == "Ubuntu" ]; then
  35     MP_QUIET="-Q"
  36 else
  37     MP_QUIET="-q"
  38 fi
  39
  40 # looking for casper specifics options as kernel parameters
  41 for x in $(cat /proc/cmdline); do
  42     case $x in
  43         netboot*)
  44             export NETBOOT=${x#netboot=} ;;
  45         toram)
  46             export TORAM=1 ;;
  47         show-cow)
  48             export SHOWCOW=1 ;;
  49         persistent)
  50             export PERSISTENT=1 ;;
  51         casper-getty)
  52             export CASPERGETTY=1 ;;
  53     esac
  54 done
  55
  56 # sort of compatibility with netboot.h from linux docs
  57 if [ -z "${NETBOOT}" ]; then
  58     if [ "${ROOT}" == "/dev/nfs" ]; then
  59         NETBOOT="nfs"
  60         export NETBOOT
  61     elif [ "${ROOT}" == "/dev/cifs" ]; then
  62         NETBOOT="cifs"
  63         export NETBOOT
  64     fi
  65 fi
  66
  67 is_casper_path() {
  68     path=$1
  69     if [ -d "$path/casper" ]; then
  70         if [ "$(echo $path/casper/*.cloop)" != "$path/casper/*.cloop" ] ||
  71             [ "$(echo $path/casper/*.squashfs)" != "$path/casper/*.squashfs" ] ||
  72             [ "$(echo $path/casper/*.ext2)" != "$path/casper/*.ext2" ] ||
  73             [ "$(echo $path/casper/*.dir)" != "$path/casper/*.dir" ]; then
  74             return 0
  75         fi
  76     fi
  77     return 1
  78 }
  79
  80 subdevices() {
  81     sysblock=$1
  82     r=""
  83     for dev in "${sysblock}" "${sysblock}"/*; do
  84         if [ -e "${dev}/dev" ]; then
  85             r="${r} ${dev}"
  86         fi
  87     done
  88     echo ${r}
  89 }
  90
  91 get_backing_device() {
  92     case "$1" in
  93         *.cloop)
  94             echo $(setup_loop "$1" "cloop" "/sys/block/cloop*")
  95             ;;
  96         *.squashfs|*.ext2)
  97             echo $(setup_loop "$1" "loop" "/sys/block/loop*")
  98             ;;
  99         *.dir)
 100             echo "directory"
 101             ;;
 102         *)
 103             panic "Unrecognized casper filesystem: $1"
 104             ;;
 105     esac
 106 }
 107
 108 match_files_in_dir() {
 109     # Does any files match pattern $1 ?
 110
 111     local pattern="$1"
 112     if [ "$(echo $pattern)" != "$pattern" ]; then
 113         return 0
 114     fi
 115     return 1
 116 }
 117
 118 mount_images_in_directory() {
 119     directory="$1"
 120     rootmnt="$2"
 121     if match_files_in_dir "$directory/casper/*.cloop"; then
 122         # Let's hope there's just one matching *.cloop... FIXME
 123         setup_devmapper $(get_backing_device "$directory/casper/*.cloop") "$rootmnt"
 124     elif match_files_in_dir "$directory/casper/*.squashfs" ||
 125         match_files_in_dir "$directory/casper/*.ext2" ||
 126         match_files_in_dir "$directory/casper/*.dir"; then
 127         setup_unionfs "$directory/casper" "$rootmnt"
 128     else
 129         :
 130     fi
 131 }
 132
 133 sys2dev() {
 134     sysdev=${1#/sys}
 135     echo "/dev/$(udevinfo -q name -p ${sysdev} 2>/dev/null|| echo ${sysdev##*/})"
 136 }
 137
 138 setup_loop() {
 139     local fspath=$1
 140     local module=$2
 141     local pattern=$3
 142
 143     modprobe "${MP_QUIET}" -b "$module"
 144     udevsettle
 145
 146     for loopdev in $pattern; do
 147         if [ "$(cat $loopdev/size)" -eq 0 ]; then
 148             dev=$(sys2dev "${loopdev}")
 149             losetup "$dev" "$fspath"
 150             echo "$dev"
 151             return 0
 152         fi
 153     done
 154     panic "No loop devices available"
 155 }
 156
 157 get_fstype() {
 158     #FIXME# one use of this function expects "unknown" another does not!
 159     # which is it???
 160     local FSTYPE
 161     local FSSIZE
 162     eval $(fstype < $1)
 163     if [ "$FSTYPE" != "unknown" ]; then
 164         echo $FSTYPE
 165         return 0
 166     fi
 167     /lib/udev/vol_id -t $1 2>/dev/null
 168 }
 169
 170 setup_devmapper() {
 171     backdev="$1"
 172     rootmnt="$2"
 173
 174     modprobe "${MP_QUIET}" -b dm-mod
 175     COW_DEVICE=/dev/ram1
 176     COW_NAME="casper-cow"
 177
 178     BACKING_FILE_SIZE=$(blockdev --getsize "$backdev")
 179     MAX_COW_SIZE=$(blockdev --getsize "$COW_DEVICE")
 180     CHUNK_SIZE=8 # sectors
 181
 182     if [ -z "$COW_SIZE" -o "$COW_SIZE" -gt "$MAX_COW_SIZE" ]; then
 183         COW_SIZE=$MAX_COW_SIZE
 184     fi
 185
 186     echo "0 $COW_SIZE linear $COW_DEVICE 0" | dmsetup create $COW_NAME
 187
 188     echo "0 $BACKING_FILE_SIZE snapshot $backdev /dev/mapper/$COW_NAME p $CHUNK_SIZE" | \
 189         dmsetup create casper-snapshot
 190     if [ "$(get_fstype $backdev)" = "unknown" ]; then
 191         panic "Unknown file system type on $backdev"
 192     fi
 193     mount -t $(get_fstype "$backdev") /dev/mapper/casper-snapshot $rootmnt || panic "Can not mount /dev/mapper/casper/snapshot on $rootmnt"
 194
 195     mkdir -p "$rootmnt/rofs"
 196     echo "0 $BACKING_FILE_SIZE linear $backdev 0" | dmsetup create casper-backing
 197     mount -t $(get_fstype "$backdev") /dev/mapper/casper-backing "$rootmnt/rofs"
 198 }
 199
 200 where_is_mounted() {
 201     device=$1
 202     if grep -q "^$device " /proc/mounts; then
 203         grep "^$device " /proc/mounts | read d mountpoint rest
 204         echo $mountpoint
 205         return 0
 206     fi
 207     return 1
 208 }
 209
 210 copy_to_ram() {
 211     copyfrom="$1"
 212
 213     if [ ! -z "${2}" ] ; then
 214         # This will enable future rampersistence, todo yet
 215         copyto="${2}"
 216         moveit="False"
 217     else
 218         copyto="${copyfrom}_swap"
 219         moveit="True"
 220     fi
 221
 222     size=$(du -ks ${copyfrom} | cut -f1)
 223     size=$(expr ${size} + ${size}/20 ) # Fixme: 5% more to be sure
 224     needed_space=$(expr ${size} * 1024)
 225     freespace=$( expr $(awk '/MemFree/{print $2}' /proc/meminfo) + $( cat /proc/meminfo | grep Cached | head -n 1 | awk '/Cached/{print $2}' - ))
 226
 227     if [ ! ${freespace} -lt ${needed_space}  ] ; then
 228         [ "$quiet" != "y" ] && log_begin_msg "Not enough free memory to copy to ram"
 229         [ "$quiet" != "y" ] && log_end_msg
 230         return
 231     else
 232         [ "$quiet" != "y" ] && log_begin_msg "Copying live media to ram..."
 233         mkdir "${copyto}"
 234         mount -t tmpfs -o size=${size}k /dev/shm ${copyto}
 235         cp -a ${copyfrom}/* ${copyto} # "cp -a" from busybox also copies hidden files
 236         umount ${copyfrom}
 237         if [ "${moveit}" == "True" ]; then
 238             mount -r -o move ${copyto} ${copyfrom}
 239             rmdir ${copyto}
 240         fi
 241         [ "$quiet" != "y" ] && log_end_msg
 242     fi
 243 }
 244
 245 find_cow_device() {
 246     pers_label="${1}"
 247     cow_backing="/${pers_label}-backing"
 248     for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop); do
 249         for dev in $(subdevices "${sysblock}"); do
 250             devname=$(sys2dev "${dev}")
 251             if [ "$(/lib/udev/vol_id -l $devname 2>/dev/null)" = "${pers_label}" ]; then
 252                 echo "$devname"
 253                 return
 254             elif [ "$(get_fstype ${devname})" = "vfat" ]; then
 255                 mkdir -p "${cow_backing}"
 256                 if where_is_mounted ${devname} > /dev/null; then
 257                     mount -o remount,rw ${devname} $(where_is_mounted ${devname}) || panic "Remounting failed"
 258                     mount -o bind $(where_is_mounted ${devname}) ${cow_backing} || panic "Cannot bind-mount"
 259                 else
 260                     mount -t $(get_fstype "${devname}") -o rw "${devname}" ${cow_backing} || panic "Cannot mount $devname on /cow-backing"
 261                 fi
 262
 263                 if [ -e "${cow_backing}/${pers_label}" ]; then
 264                     echo $(setup_loop "${cow_backing}/${pers_label}" "loop" "/sys/block/loop*")
 265                     return 0
 266                 else
 267                     umount ${cow_backing}
 268                 fi
 269             fi
 270         done
 271     done
 272 }
 273
 274 do_netmount() {
 275     rc=1
 276
 277     modprobe "${MP_QUIET}" af_packet # For DHCP
 278
 279     ipconfig ${DEVICE} /tmp/net-${DEVICE}.conf
 280
 281     if [ "${NFSROOT}" = "auto" ]; then
 282         NFSROOT=${ROOTSERVER}:${ROOTPATH}
 283     fi
 284
 285     [ "$quiet" != "y" ] && log_begin_msg "Trying netboot from ${NFSROOT}"
 286
 287     if [ "${NETBOOT}" != "nfs" ] && do_cifsmount ; then
 288         rc=0
 289     elif do_nfsmount ; then
 290         NETBOOT="nfs"
 291         export NETBOOT
 292         rc=0
 293     fi
 294
 295     [ "$quiet" != "y" ] && log_end_msg
 296     return ${rc}
 297 }
 298
 299 do_nfsmount() {
 300     rc=1
 301     modprobe "${MP_QUIET}" nfs
 302     if [ -z "${NFSOPTS}" ]; then
 303         NFSOPTS=""
 304     fi
 305
 306     [ "$quiet" != "y" ] && log_begin_msg "Trying nfsmount -o nolock -o ro ${NFSOPTS} ${NFSROOT} ${mountpoint}"
 307     # FIXME: This for loop is an ugly HACK round an nfs bug
 308     for i in 0 1 2 3 4 5 6 7 8 9 a b c d e f 10 11 12 13; do
 309         nfsmount -o nolock -o ro ${NFSOPTS} "${NFSROOT}" "${mountpoint}" && rc=0 && break
 310         sleep 1
 311     done
 312     return ${rc}
 313 }
 314
 315 do_cifsmount() {
 316     rc=1
 317     if [ -x "/sbin/mount.cifs" ]; then
 318         if [ -z "${NFSOPTS}" ]; then
 319             CIFSOPTS="-ouser=root,password="
 320         else
 321             CIFSOPTS="${NFSOPTS}"
 322         fi
 323
 324         [ "$quiet" != "y" ] && log_begin_msg "Trying mount.cifs ${NFSROOT} ${mountpoint} ${CIFSOPTS}"
 325         modprobe "${MP_QUIET}" cifs
 326
 327         if mount.cifs "${NFSROOT}" "${mountpoint}" "${CIFSOPTS}" ; then
 328             rc=0
 329         fi
 330     fi
 331     return ${rc}
 332 }
 333
 334 setup_unionfs() {
 335     image_directory="$1"
 336     rootmnt="$2"
 337
 338     modprobe "${MP_QUIET}" -b unionfs
 339
 340     # run-init can't deal with this, but we're going to move all of these
 341     # away before it runs anyway.
 342     croot="/casper"
 343
 344     # Let's just mount the read-only file systems first
 345     rofsstring=""
 346     rofslist=""
 347     if [ "${NETBOOT}" == "nfs" ] ; then
 348         roopt="nfsro" # go aroung a bug in nfs-unionfs locking
 349     else
 350         roopt="ro"
 351     fi
 352
 353     mkdir -p "${croot}"
 354     for image_type in "ext2" "squashfs" "dir" ; do
 355         for image in "${image_directory}"/*."${image_type}"; do
 356             imagename=$(basename "${image}")
 357             if [ -d "${image}" ]; then
 358                 # it is a plain directory: do nothing
 359                 rofsstring="${image}=${roopt}:${rofsstring}"
 360                 rofslist="${image} ${rofslist}"
 361             elif [ -f "${image}" ]; then
 362                 backdev=$(get_backing_device "$image")
 363                 fstype=$(get_fstype "${backdev}")
 364                 if [ "${fstype}" = "unknown" ]; then
 365                     panic "Unknown file system type on ${backdev} (${image})"
 366                 fi
 367                 mkdir -p "${croot}/${imagename}"
 368                 mount -t "${fstype}" -o ro "${backdev}" "${croot}/${imagename}" || panic "Can not mount $backdev ($image) on ${croot}/${imagename}" && rofsstring="${croot}/${imagename}=${roopt}:${rofsstring}" && rofslist="${croot}/${imagename} ${rofslist}"
 369             fi
 370         done
 371     done
 372     rofsstring=${rofsstring%:}
 373
 374     mkdir -p /cow
 375     cowdevice="tmpfs"
 376     cow_fstype="tmpfs"
 377
 378     # Looking for "${root_persistence}" device or file
 379     if [ ! -z "${PERSISTENT}" ]; then
 380         cowprobe=$(find_cow_device "${root_persistence}")
 381         if [ -b "${cowprobe}" ]; then
 382             cowdevice=${cowprobe}
 383             cow_fstype=$(get_fstype "${cowprobe}")
 384         else
 385             [ "$quiet" != "y" ] &&    log_begin_msg "Unable to find the persistent medium"
 386         fi
 387     fi
 388
 389     mount ${cowdevice} -t ${cow_fstype} -o rw /cow || panic "Can not mount $cowdevice on /cow"
 390
 391     mount -t unionfs -o dirs=/cow=rw:$rofsstring unionfs "$rootmnt" || panic "Unionfs mount failed"
 392
 393     for d in ${rofslist}; do
 394         mkdir -p "${rootmnt}/casper/${d##*/}"
 395         case d in
 396             *.dir) mount -o bind "${d}" "${rootmnt}/casper/${d##*/}" ;;
 397             *) mount -o move "${d}" "${rootmnt}/casper/${d##*/}" ;;
 398         esac
 399     done
 400
 401     # Adding other custom mounts
 402     if [ ! -z "${PERSISTENT}" ]; then
 403         homecow=$(find_cow_device "${home_persistence}" )
 404         if [ -b "${homecow}" ]; then
 405             mount ${homecow} -t $(get_fstype "${homecow}") -o rw "${rootmnt}/home"
 406         else
 407             [ "$quiet" != "y" ] &&  log_begin_msg "Unable to find the persistent home medium"
 408         fi
 409     fi
 410
 411     if [ ! -z "${SHOWCOW}" ]; then
 412         mkdir -p "$rootmnt/cow"
 413         mount -o bind /cow "$rootmnt/cow"
 414     fi
 415 }
 416
 417 is_usb_device() {
 418     sysfs_path="${1#/sys}"
 419     if /lib/udev/path_id "${sysfs_path}" | grep -Eq "ID_PATH=(usb|pci-[^-]*-usb)"; then
 420         return 0
 421     fi
 422     return 1
 423 }
 424
 425 find_livefs() {
 426     mounted=
 427     for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop | grep -v ram); do
 428         devname=$(sys2dev "${sysblock}")
 429         fstype=$(get_fstype "${devname}")
 430         if /lib/udev/cdrom_id ${devname} > /dev/null; then
 431             mount -t ${fstype} -o ro "$devname" $mountpoint || continue
 432             if is_casper_path $mountpoint; then
 433                 echo $mountpoint
 434                 return
 435             else
 436                 umount $mountpoint
 437             fi
 438         elif is_usb_device "$sysblock"; then
 439             for dev in $(subdevices "${sysblock}"); do
 440                 devname=$(sys2dev "${dev}")
 441                 fstype=$(get_fstype "${devname}")
 442                 case ${fstype} in
 443                     vfat|iso9660|udf)
 444                         mount -t ${fstype} -o ro "${devname}" $mountpoint || continue
 445                         if is_casper_path $mountpoint; then
 446                             echo $mountpoint
 447                             return
 448                         else
 449                             umount $mountpoint
 450                         fi
 451                         ;;
 452                 esac
 453             done
 454         elif [ "${fstype}" = "squashfs" ||  \
 455                 "${fstype}" = "ext2" ]; then
 456
 457             # This is an ugly hack situation, the block device has
 458             # an image directly on it.  It's hopefully
 459             # casper, so take it and run with it.
 460
 461             ln -s "${devname}" "${devname}.${fstype}"
 462             echo "${devname}.${fstype}"
 463             return
 464         fi
 465     done
 466 }
 467
 468 set_usplash_timeout() {
 469     if [ -x /sbin/usplash_write ]; then
 470         /sbin/usplash_write "TIMEOUT 120"
 471     fi
 472 }
 473
 474 mountroot() {
 475     exec 6>&1
 476     exec 7>&2
 477     exec > casper.log
 478     exec 2>&1
 479
 480     set_usplash_timeout
 481     [ "$quiet" != "y" ] && log_begin_msg "Running /scripts/casper-premount"
 482     run_scripts /scripts/casper-premount
 483     [ "$quiet" != "y" ] && log_end_msg
 484
 485     # Needed here too because some things (*cough* udev *cough*)
 486     # changes the timeout
 487
 488     set_usplash_timeout
 489
 490     if [ ! -z "${NETBOOT}" ]; then
 491         if do_netmount ; then
 492             livefs_root="${mountpoint}"
 493         else
 494             panic "Unable to find a the network rootfs live file system"
 495         fi
 496     else
 497         # Scan local devices for the image
 498         for i in 0 1 2 3 4 5 6 7 8 9 a b c d e f 10 11 12 13; do
 499             livefs_root=$(find_livefs)
 500             if [ "${livefs_root}" ]; then
 501                 break
 502             fi
 503         done
 504
 505         if [ "$?" -gt 0 ]; then
 506             panic "Unable to find a medium containing a live file system"
 507         fi
 508
 509         if [ ! -z "${TORAM}" ]; then
 510             copy_to_ram "${livefs_root}"
 511         fi
 512     fi
 513     sleep 1
 514
 515     mount_images_in_directory "$livefs_root" "$rootmnt"
 516
 517     log_end_msg
 518
 519     maybe_break casper-bottom
 520     [ "$quiet" != "y" ] && log_begin_msg "Running /scripts/casper-bottom"
 521
 522     run_scripts /scripts/casper-bottom
 523     [ "$quiet" != "y" ] && log_end_msg
 524
 525     exec 1>&6 6>&-
 526     exec 2>&7 7>&-
 527     cp casper.log "${rootmnt}/var/log/"
 528 }