package/aufs2-util/src/aubrsync

   1 #!/bin/sh
   2
   3 # Copyright (C) 2005-2009 Junjiro Okajima
   4 #
   5 # This program, aufs is free software; you can redistribute it and/or modify
   6 # it under the terms of the GNU General Public License as published by
   7 # the Free Software Foundation; either version 2 of the License, or
   8 # (at your option) any later version.
   9 #
  10 # This program is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 # GNU General Public License for more details.
  14 #
  15 # You should have received a copy of the GNU General Public License
  16 # along with this program; if not, write to the Free Software
  17 # Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18
  19 #
  20 # The development of this script is sponcered by ASUSTek Computer Inc.
  21 # Kindly they agreed that I keep my aufs work as free software as it has
  22 # been.
  23 #
  24
  25 set -eu
  26 #set -x
  27
  28 me=$(basename $0)
  29 EEcho() # str
  30 {
  31         echo ${me}: $@ 1>&2
  32 }
  33
  34 f=/sbin/mount.aufs
  35 test ! -x $f && EEcho $f is not installed && exit 1
  36
  37 # special handling for backward compatibility.
  38 #
  39 # aufs in the donated eeepc is aufs1 20080211 without CONFIG_AUFS_COMPAT.
  40 # /etc/default/aufs was introduced in aufs1 20080922.
  41 # shwh/noshwh was introduced in aufs1 20080310 with CONFIG_AUFS_SHWH.
  42 # noshwh became always available regardless CONFIG_AUFS_SHWH in aufs1 20081117.
  43
  44 noshwh=1
  45 AUFS_VERSION=20080211
  46 f=/etc/default/aufs
  47 if [ -s $f ]
  48 then
  49         . $f
  50 else
  51         echo ${me}: warning, broken $f, assuming aufs is $AUFS_VERSION
  52         f=/usr/lib/aufs.shlib
  53         test ! -s $f && EEcho $f is not installed && exit 1
  54         . $f
  55
  56         case $AUFS_VERSION in
  57         200*) # aufs1
  58                 test $AUFS_VERSION -lt 20081117 && noshwh=0
  59                 ;;
  60         esac
  61         AUFS_SUPER_MAGIC=1635083891
  62         AUFS_SUPER_MAGIC_HEX=0x61756673
  63         AUFS_WH_PFX=.wh.
  64         AUFS_WH_PFX2=.wh..wh.
  65         AUFS_WH_DIROPQ=.wh..wh..opq
  66 fi
  67
  68 ########################################
  69
  70 _Rsync="rsync --exclude=lost+found"
  71 Rsync="$_Rsync -aHSx --devices --specials --delete-before"
  72 Copy="$Rsync"
  73 Move="$Copy"
  74 RsyncWh="$_Rsync -ptgoHx"
  75
  76 FindForRm() # rw
  77 {
  78         echo "find \"$1\" -xdev -depth \(
  79                 \( ! -type d
  80                         \( -name $AUFS_WH_DIROPQ
  81                         -o ! -name ${AUFS_WH_PFX2}\* \) \)
  82                 -o \( -type d
  83                         ! -name ${AUFS_WH_PFX2}\*
  84                         ! -wholename \"$1\"
  85                         ! -wholename \"$1/lost+found\" \)
  86                 \) -print0"
  87 }
  88
  89 MoveWh() # rw ro+wh
  90 {
  91         cd "$1"
  92         find . -xdev -name ${AUFS_WH_PFX}\* ! -name ${AUFS_WH_PFX2}\* \
  93                 -printf '%P\n' |
  94         while read wh
  95         do
  96                 f=$(echo "$wh" | sed -e '
  97                         s/^'${AUFS_WH_PFX}'//
  98                         t
  99                         s:/'${AUFS_WH_PFX}':/:
 100                         ')
 101                 test -e "$dst/$f" || echo "$wh"
 102         done |
 103         # -v
 104         $RsyncWh --files-from=- ./ "$2"
 105         cd "$OLDPWD"
 106 }
 107
 108 copy()
 109 {
 110         $Copy $@ "$mntpnt"/ "$dst"
 111 }
 112
 113 _move()
 114 {
 115         set +x
 116         test $hinotify -ne 1 && echo ${me}: warning, -i is not specified
 117         src_is_nfs=0
 118         test $(stat -f -c %T "$src") = nfs && src_is_nfs=1
 119         set $quiet
 120
 121         $Move $@ &&
 122         eval $(FindForRm "$src") |
 123         {
 124                 if [ $src_is_nfs -eq 1 ]
 125                 then
 126                         mount -o remount "$mntpnt"
 127                         mount -o remount "$src"
 128                 fi
 129                 xargs -r0 rm -fr #-v
 130         }
 131 }
 132
 133 move()
 134 {
 135         _move $@ "$mntpnt"/ "$dst"
 136 }
 137
 138 move_with_wh()
 139 {
 140         {
 141         set +x
 142         MoveWh "$src" "$dst"
 143         set $quiet
 144         } &&
 145         move --exclude=${AUFS_WH_PFX}\*
 146 }
 147
 148 # backward compatibility
 149 move_w()
 150 {
 151         move_with_wh $@
 152 }
 153
 154 Usage()
 155 {
 156         t=$(FindForRm src_branch | sed -e '
 157                 s/"//g
 158                 $b
 159                 s/$/ \\/')
 160
 161         cat <<- EOF
 162         $me Options move | move_with_wh | copy \\
 163                 mntpnt src_branch dst_branch [ options for rsync ]
 164
 165         generic form:
 166         $me [ -w | --wh ] [ -i | --inotify ] Options \\
 167                 mntpnt cmd [ parameters for cmd ]
 168
 169         Options:
 170                 [ -n | --dry_run ]
 171                 [ -q | --quiet ]
 172
 173         The dst_branch must be mounted as writable.
 174         During the operation, the mntpnt is set readonly.
 175         If you are opening a file for writing on the writable branch,
 176         you need to close the file before invoking this script.
 177         The -w or --wh option requires CONFIG_AUFS_SHWH enabled.
 178         The -i or --inotify option requires CONFIG_AUFS_HINOTIFY enabled.
 179
 180         'copy' is a shortcut for
 181                 $me mntpnt \\
 182                 $Copy mntpnt/ dst_branch
 183         'move' is a shortcut for
 184                 $me mntpnt \\
 185                 "$Move \\
 186                 mntpnt/ dst_branch && \\
 187                 $t |\\
 188                 xargs -r0 rm -fr"
 189                 Note: in most cases, you will need '-i' option, and
 190                       find(1) is invoked by $me only when rsync(1)
 191                       succeded.
 192         'move_with_wh' is a simple variation of 'move' which moves
 193         whiteouts separately before the actual 'move'.
 194
 195         If you execute this script under linux-2.6.24 or earlier, the
 196         kernel may produce a harmless warning "inotify.c:NNN
 197         set_dentry_child_flags()". The message was already removed in
 198         linux-2.6.25.
 199
 200         examples:
 201         - Copy and reflect all the modification (modifed files, newly
 202           created and removed ones) in the upper branch to the lower
 203           branch. This operation is for aufs which has only 2 branches,
 204           and mainly for a system shutdown script.
 205           All files on the upper branch remain.
 206
 207           $ sudo $me copy /your/aufs /your/upper_branch /your/lower_branch
 208
 209         - Like above (2 branches), move and reflect all modifications
 210           from upper to lower. Almost all files on the upper branch will
 211           be removed. You can still use this aufs after the
 212           operation. But the inode number may be changed. If your
 213           application which depends upon the inode number was running at
 214           that time, it may not work correctly.
 215
 216           $ sudo $me move /your/aufs /your/upper_branch /your/lower_branch
 217         EOF
 218
 219 #       - Like above (2 branches), generate a new middle layer like a
 220 #         snapshot including whiteouts and make the upper_branch almost
 221 #         empty, but untouch the lower_branch.
 222 #
 223 #         $ img=/hda1/a.ext2
 224 #         $ dd if=/dev/zero of=\$img bs=4k count=1k
 225 #         $ mkfs -t ext2 -F \$img
 226 #         $ sudo mount -o rw,loop \$img /your/new_branch
 227 #         $ sudo mount -o remount,ins:1:/your/new_branch=ro+wh /your/aufs
 228 #         $ sudo $me _move /your/aufs /your/upper_branch /your/lower_branch \\
 229 #               "--remove-source-files \\
 230 #               --exclude=$AUFS_WH_BASE \\
 231 #               --exclude=$AUFS_WH_PLINKDIR \\
 232 #               --exclude=$AUFS_WH_TMPDIR \\
 233 #               /your/upper_branch/ /your/new_branch; \\
 234 #               mount -o remount,ro /your/new_branch"
 235 #       EOF
 236 }
 237
 238 ########################################
 239
 240 wh=0
 241 hinotify=0
 242 quiet=-x
 243 dry_run=
 244 cmd=
 245 cmd_opts=
 246 for i
 247 do
 248         case $i in
 249         -w|--wh)        wh=1;;
 250         -i|--inotify)   hinotify=1;;
 251         -n|--dry_run)   dry_run=echo;;
 252         -q|--quiet)     quiet=+x;;
 253         -h|--help)      Usage; exit 0;;
 254         --)             shift; break;;
 255         *)              break;;
 256         esac
 257         shift
 258 done
 259
 260 test $# -lt 2 && Usage 1>&2 && exit 1
 261 case "$1" in
 262 _move|move|copy|move_w|move_with_wh)
 263         test $# -lt 4 && Usage 1>&2 && exit 1
 264         cmd=$1
 265         SetDir mntpnt "$2"
 266         SetDir src "$3"
 267         SetDir dst "$4"
 268         shift 4
 269         wh=0
 270         ;;
 271 *)
 272         SetDir mntpnt "$1"
 273         cmd="$2"
 274         shift 2
 275         ;;
 276 esac
 277 cmd_opts="$@"
 278
 279 case $(stat -f -c %T "$mntpnt") in
 280 aufs|UNKNOWN*${AUFS_SUPER_MAGIC_HEX}*)  ;;
 281 *)
 282         EEcho "$mntpnt" is not aufs
 283         exit 1
 284         ;;
 285 esac
 286
 287 cur_opts=$(MntOpts "$mntpnt")
 288 test ! "$cur_opts" &&
 289 EEcho bad /proc/mounts or "$mntpnt" is not mounted &&
 290 exit 1
 291 cur_opts="udba=reval,noshwh,$cur_opts"
 292 test $noshwh -eq 0 && cur_opts=$(echo $cur_opts | sed -e 's/,noshwh//')
 293
 294 # force flushing the pusedo-links
 295 tmp_opts="remount,ro,udba=reval,noshwh"
 296 test $noshwh -eq 0 && tmp_opts=$(echo $tmp_opts | sed -e 's/,noshwh//')
 297 test $wh -eq 1 && tmp_opts="$tmp_opts,shwh"
 298 test $hinotify -eq 1 && tmp_opts="$tmp_opts,udba=inotify"
 299
 300 # here we go
 301 trap "$dry_run mount -o remount,$cur_opts \"$mntpnt\"" EXIT
 302 set $quiet
 303 $dry_run mount -o $tmp_opts "$mntpnt"
 304 eval "$dry_run $cmd $cmd_opts"