/usr/sbin/snapmergepuppy (tahrpup)

#!/bin/ash
#2007 Lesser GPL licence v2 (http://www.fsf.org/licensing/licenses/lgpl.html)
#Barry Kauler www.puppylinux.com
#called from savepuppyd and rc.shutdown, to save tmpfs layer to permanent flash storage.
#updated 13 Sept 2007. copy-down only. flushing is done in petget.
#updated 24 Sept 2007. removed '-u' option when copy-down files.
#8 oct 2007: screen out /root/tmp when saving.
#4 nov 2007: reintroduce '-u' copy option.
#v4.01 19may2008 BK: now called from /sbin/pup_eventd daemon (savepuppyd now history).
#v4.01 19may2008 BK: if called from pup_eventd then X running: graceful exit if X shutdown.
#v409 BK: XRUNNING test should be 'pup_event_frontend_d'.
#v409 BK: save /var dir. previously screened out to save space, but prevents crontab from running.
#v412 /etc/DISTRO_SPECS, renamed pup_xxx.sfs, pup_save.2fs etc.
#w000 pup files renamed to woofr555.sfs, woofsave.2fs.
#w003 bug fix for .wh.__dir_opaque whiteout file.
#w003 screened out some dirs in /dev that should not be saved.
#v424 fix for more layers in unionfs/aufs.
#100222 shinobar: possible timezone problem with BOOTCONFIG. more file exclusions.
#100422 added ^root/ftpd exclusion.
#100429 modify 'trash' exclusion.
#100820 added /var/tmp exclusion (apparently filled by opera crashes).
#101221 yaf-splash fix.
#110206 Dougal: clean up some testing. speedup: LANG=C, also change to /bin/ash.
#110212 recent aufs: .wh.__dir_opaque name changed to .wh..wh..opq.
#110212 Jemimah: files may disappear, more efficient calc of free space, fix i/o err.
#110222 shinobar: remove all /dev, allow 'pup_ro10-19', exit code for no space
#110224 BK: revert remove all /dev, for now. 110503 added dev/snd
#110505 support sudo for non-root user.
#111229 rerwin: fix jemimah code (110212).
#120103 rerwin: screen out /.XLOADED when save.
#140102 SFR: various fixes + gettext
#140512 SFR: performance improvements

[ "`whoami`" != "root" ] && exec sudo -A ${0} ${@} #110505

export TEXTDOMAIN=snapmergepuppy
export OUTPUT_CHARSET=UTF-8

OLDLANG="$LANG"
export LANG=C #110206 Dougal: I **think** this should not cause problems with filenames

#variables created at bootup by 'init' script in initramfs...
. /etc/rc.d/PUPSTATE
. /etc/DISTRO_SPECS #v412
SAVEPART="`echo -n "$PUPSAVE" | cut -f 1 -d ','`"

#v3.02 first time, do not use '-u' option when saving, save everything...
NEXTPASSTHRU=""
[ -e /tmp/flagnextpassthru ] && NEXTPASSTHRU="yes"

RUNPS="`busybox ps`"
SHUTDOWN="no"
[ "`echo "$RUNPS" | grep 'rc.shutdown'`" != "" ] && SHUTDOWN="yes"
XRUNNING="no"
[ "`echo "$RUNPS" | grep 'pup_event_frontend_d'`" != "" ] && XRUNNING="yes"

PATH="/bin:/sbin:/usr/bin:/usr/sbin:/usr/X11R7/bin"
WD="`pwd`"

# all the action takes places inside $SNAP (ex: /initrd/pup_rw)
SNAP="`cat /sys/fs/aufs/si_*/br0 | head -1 | cut -f1 -d'='`"
cd $SNAP || exit 1

# files are copied from $SNAP/* to $BASE/ (ex: /initrd/pup_ro1)
BASE="`cat /sys/fs/aufs/si_*/br1 | head -1 | cut -f1 -d'='`"
BASEMTP="`df-FULL --output=target "$BASE" | tail -1`"

# Precautions
[ $PUPMODE -eq 3 -o $PUPMODE -eq 7 -o $PUPMODE -eq 13 ] || { echo "Wrong PUPMODE ($PUPMODE)!"; exit 1; }
mountpoint -q "$BASEMTP" || { echo "$BASEMTP is not mounted!"; exit 1; }

echo "Merging $SNAP onto $BASE..."

# =============================================================================
# WHITEOUTS
# =============================================================================

for XFL in /sys/fs/aufs/si_*/br[0-9]* #get aufs branch list
do
 XFN="${XFL##*/}"
 [ ${XFN:2} -lt 2 ] && continue
 SFSPoints="${SFSPoints}`cat ${XFL} | cut -f1 -d'='` "
done

find . -mount \( -regex '.*/\.wh\.[^/]*' -type f \) | sed -e 's/\.\///;s/\.wh\.//' |
while read -r N
do
 DN="${N%/*}"
 BN="${N##*/}"
 [ "$DN" = "$N" ] || [ "$DN" = "" ] && DN="."
 [ "$DN" = "." ] && continue
 [ "$BN" = ".wh.aufs" ] && continue #w003 aufs has file .wh..wh.aufs in /initrd/pup_rw.

 #110212 unionfs and early aufs: '.wh.__dir_opaque' marks ignore all contents in lower layers...
 if [ "$BN" = "__dir_opaque" ];then #w003
  #'.wh.__dir_opaque' marks ignore all contents in lower layers...
  rm -rf "${BASE}/${DN}" 2>/dev/null #wipe anything in save layer. 110212 delete entire dir.
  mkdir -p "${BASE}/${DN}" #jemimah: files sometimes mysteriously reappear if you don't delete and recreate the directory, aufs bug? 111229 rerwin: need -p, may have to create parent dir.
  #also need to save the whiteout file to block all lower layers (may be readonly)...
  touch "${BASE}/${DN}/.wh.__dir_opaque" 2>/dev/null
  rm -f "$SNAP/$DN/.wh.__dir_opaque" #should force aufs layer "reval".
  continue
 fi
 #110212 recent aufs: .wh.__dir_opaque name changed to .wh..wh..opq ...
 if [ "$BN" = ".wh..opq" ] ; then
  rm -rf "${BASE}/${DN}" 2>/dev/null  #wipe anything in save layer.
  mkdir -p "${BASE}/${DN}" #jemimah: files sometimes mysteriously reappear if you don't delete and recreate the directory, aufs bug? 111229 rerwin: need -p, may have to create parent dir.
  #also need to save the whiteout file to block all lower layers (may be readonly)...
  touch "${BASE}/${DN}/.wh..wh..opq" 2>/dev/null
  rm -f "$SNAP/$DN/.wh..wh..opq"  #should force aufs layer "reval".
  continue
 fi
 #comes in here with the '.wh.' prefix stripped off, leaving actual filename...
 rm -rf "$BASE/$N"

 #if file exists on a lower layer, have to save the whiteout file...
 #110206 Dougal: speedup and refine the search...
 for P in $SFSPoints
 do
   if [ -e "$P/$N" ] || [ -L "$P/$N" ] ; then   # SFR: broken symlinks also deserve to be processed ( '-e' won't detect them, needs to be also '-L')
     [ -d "${BASE}/${DN}" ] || mkdir -p "${BASE}/${DN}"
     touch "${BASE}/${DN}/.wh.${BN}"
     break
   fi
 done #110206 End Dougal.
 rm -f "$SNAP/$DN/.wh.$BN" #remove whiteout file. should force aufs layer "reval".
done

# =============================================================================
# DIRECTORIES
# =============================================================================

#110224 BK revert, leave save of /dev in for now, just take out some subdirs... 110503 added dev/snd
find . -mount -type d | tail +2 | sed -e 's/\.\///' | grep -v -E '^mnt|^initrd|^proc|^sys|^tmp|^root/tmp|^\.wh\.|/\.wh\.|^dev/\.|^dev/fd|^dev/pts|^dev/shm|^dev/snd|^var/tmp' |
while read -r N
do
 #v4.01 graceful exit if shutdown X (see /usr/X11R7/bin/restartwm,wmreboot,wmpoweroff)...
 [ "$XRUNNING" = "yes" ] && [ -f /tmp/wmexitmode.txt ] && exit
 mkdir -p "$BASE/$N"
 #i think nathan advised this, to handle non-root user (SFR: improved/simplified)
 chmod "$BASE/$N" --reference="$N"
 OWNERSHIP="`stat --format=%u:%g "$N"`"
 chown $OWNERSHIP "$BASE/$N"
 touch "$BASE/$N" --reference="$N"
done

# =============================================================================
# FILES
# =============================================================================

#100222 a quick hack: BOOTCONFIG written to in init, before timezone set, can cause trouble...
touch /etc/rc.d/BOOTCONFIG
FREEBASE=`df -B 1 | grep -w "$BASEMTP"| head -n 1 | tr -s ' ' | cut -f 4 -d ' '` #110212 Jemimah #110222 shinobar # SFR: result in bytes (see 'find' below)

rm -f /tmp/snapmergepuppy-nospace #110222 shinobar
rm -f /tmp/snapmergepuppy-error   #140102 SFR

#Copy Files... v409 remove '^var'. w003 screen out some /dev files. 100222 shinobar: more exclusions. 100422 added ^root/ftpd. 100429 modify 'trash' exclusion. 100820 added var/tmp #110224 BK: revert, leave save of /dev in for now... 120103 rerwin: add .XLOADED # SFR: added dev/snd # SFR: added .crdownload
# SFR: move as much as possible into 'find' itself
# Limitation - files with newline (\n) in its name are processed wrong (but this is not a new issue)
find . -mount \
       -not -path . \
       -not -type d \
       -regextype posix-extended \
       -not \( -regex '.*/\.wh\.[^\]*' -type f \) \
       -not \( -regex '^./mnt.*|^./proc.*|^./sys.*|^./tmp.*|^./pup_.*|^./zdrv_.*|^./root/tmp.*|.*_zdrv_.*|^./dev/\..*|^./dev/fd.*|^./dev/pts.*|^./dev/snd.*|^./dev/shm.*|^./dev/tty.*|^./\.wh\..*|^./var/run.*|^./root/ftpd.*|^./var/tmp.*|.*\.XLOADED$' \) \
       -not \( -regex '.*\.thumbnails.*|.*\.part$|.*\.crdownload$' \) \
       -printf "%s %C@ %P\n" |
while read -r NSIZE NCTIME N
do
 #v4.01 graceful exit if shutdown X (see /usr/X11R7/bin/restartwm,wmreboot,wmpoweroff)...
 [ "$XRUNNING" = "yes" ] && [ -f /tmp/wmexitmode.txt ] && exit

 ([ ! -e "$N" ] && [ ! -L "$N" ]) && continue # SFR: skip non-existing files (btw, '-e' won't detect broken symlinks, so '-L' is necessary!)

 #stop saving if not enough room left in ${DISTRO_FILE_PREFIX}save file...
 if [ $((NSIZE+204800)) -gt $FREEBASE ]; then   # 204800 = 200K slack space
  FREEBASE=`df -B 1 | grep -w "$BASEMTP" | head -n 1 | tr -s ' ' | cut -f 4 -d ' '` #110212 Jemimah: this is very slow; try not to check every iteration #110222 shinobar: fix for pup_ro10 and more
  if [ $((NSIZE+204800)) -gt $FREEBASE ]; then  #110212 Jemimah.
   touch /tmp/snapmergepuppy-nospace  #110222 shinobar
   break
  fi
 else
  FREEBASE=$((FREEBASE-NSIZE)) #110212 Jemimah: keep track of the worst case
 fi

 ##v2.21 -u causes trouble if timezone malconfigured...
 [ -L "$BASE/$N" ] && rm -f "$BASE/$N"
 if [ -L "$N" -o "$NEXTPASSTHRU" = "" ];then
  #link, or first run of snapmergepuppy. no '-u' (update) option.
  [ -L "$N" ] && [ -d "$BASE/$N" ] && rm -rf "$BASE/$N" # SFR: in case if folder has been replaced with a symlink (cp won't overwrite a dir with a symlink)
  cp -a -f "$N" "$BASE/$N" 2>>/tmp/snapmergepuppy-error
  rm "$N"
 else
  [ ! -e "$BASE/$N" ] || [ ${NCTIME%%.*} -gt `stat -c %Z "$BASE/$N"` ] && { cp -a -f "$N" "$BASE/$N" 2>>/tmp/snapmergepuppy-error; rm "$N"; }
 fi

 DN="${N%/*}" #111229 rerwin: bugfix for jemimah code (110212) (SFR: improved performance)
 BN="${N##*/}" #111229  "
 [ "$DN" = "$N" ] || [ "$DN" = "" ] && DN="."
 [ -e "$BASE/$DN/.wh.${BN}" ] && rm "$BASE/$DN/.wh.${BN}" #110212 jemimah bugfix - I/O errors if you don't do this

done

# =============================================================================

touch /tmp/flagnextpassthru

# SFR: fix for .wh files not being created (in some cases) in pup_rw
# force re-evalution of all the layers
busybox mount -t aufs -o remount,udba=reval unionfs /

sync
cd "$WD"

# =============================================================================

error_msg () {
  if [ "$SHUTDOWN" = "no" -a "$XRUNNING" = "yes" ];then
    export DISPLAY=':0'
    /usr/lib/gtkdialog/box_splash -timeout 30 -close box -icon gtk-dialog-warning -bg red -text "$1"
  else
    echo "$1"
  fi
}

export LANG="$OLDLANG"
ERRSTATUS=0

if [ -f /tmp/snapmergepuppy-nospace ]; then #110222 shinobar
  ERRMSG="$(gettext 'WARNING!
Unable to save all files. You need to delete some.')"
  error_msg "$ERRMSG"
  ERRSTATUS=1
fi

sed -i '/No such file or directory/d' /tmp/snapmergepuppy-error # discard errors caused by bad timing

if [ -s /tmp/snapmergepuppy-error ]; then   #140102 SFR
  ERRMSG="$(gettext "WARNING!
There were some errors detected.
(see '/tmp/snapmergepuppy-error' for details)
Filesystem check of the savefile (pfix=fsck) is highly recommended.")"
  error_msg "$ERRMSG"
  ERRSTATUS=1
fi

exit $ERRSTATUS

# =============================================================================