mdw@git.distorted.org.uk Git - rsync-backup/blob - rsync-backup.in

   1 #! @BASH@
   2 ###
   3 ### Backup script
   4 ###
   5 ### (c) 2012 Mark Wooding
   6 ###
   7
   8 ###----- Licensing notice ---------------------------------------------------
   9 ###
  10 ### This file is part of the `rsync-backup' program.
  11 ###
  12 ### rsync-backup is free software; you can redistribute it and/or modify
  13 ### it under the terms of the GNU General Public License as published by
  14 ### the Free Software Foundation; either version 2 of the License, or
  15 ### (at your option) any later version.
  16 ###
  17 ### rsync-backup is distributed in the hope that it will be useful,
  18 ### but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ### MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ### GNU General Public License for more details.
  21 ###
  22 ### You should have received a copy of the GNU General Public License
  23 ### along with rsync-backup; if not, write to the Free Software Foundation,
  24 ### Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25
  26 set -e
  27
  28 thishost=$(hostname -s)
  29 quis=${0##*/}
  30 . @pkgdatadir@/lib.sh
  31
  32 verbose=:
  33 dryrun=nil
  34
  35 ###--------------------------------------------------------------------------
  36 ### Utility functions.
  37
  38 RSYNCOPTS="--verbose"
  39
  40 do_rsync () {
  41   ## Run rsync(1) in an appropriate manner.  Configuration should ovrride
  42   ## this or set $RSYNCOPTS if it wants to do something weirder.  Arguments
  43   ## to this function are passed on to rsync.
  44
  45   rsync \
  46         --archive --hard-links --numeric-ids --del \
  47         --sparse --compress \
  48         --one-file-system \
  49         --partial \
  50         $RSYNCOPTS \
  51         --filter="dir-merge .rsync-backup" \
  52         "$@"
  53 }
  54
  55 log () {
  56   case $dryrun in
  57     t)
  58       echo >&2 "                *** $*"
  59       ;;
  60     nil)
  61       now=$(date +"%Y-%m-%d %H:%M:%S %z")
  62       echo >&9 "$now $*"
  63       ;;
  64   esac
  65 }
  66
  67 maybe () {
  68   ## Run CMD, if this isn't a dry run.
  69
  70   case $dryrun in
  71     t) echo >&2 "               +++ $*" ;;
  72     nil) "$@" ;;
  73   esac
  74 }
  75
  76 copy () {
  77   prefix=$1
  78   ## Copy lines from stdin to stdout, adding PREFIX.
  79
  80   while IFS= read -r line; do
  81     printf "%s %s\n" "$prefix" "$line"
  82   done
  83 }
  84
  85 run () {
  86   tag=$1 cmd=$2; shift 2
  87   ## Run CMD, logging its output in a pleasing manner.
  88
  89   case $dryrun in
  90     t)
  91       echo >&2 "                *** RUN $tag"
  92       echo >&2 "                +++ $cmd $*"
  93       rc=0
  94       ;;
  95     nil)
  96       log "BEGIN $tag"
  97       rc=$(
  98         { { { ( set +e
  99                 "$cmd" "$@" 3>&- 4>&- 5>&- 9>&-
 100                 echo $? >&5; ) |
 101               copy "|" >&4; } 2>&1 |
 102             copy "*" >&4; } 4>&1 |
 103           cat >&9; } 5>&1 </dev/null
 104       )
 105       case $rc in
 106         0) log "END $tag" ;;
 107         *) log "FAIL $tag (rc = $rc)" ;;
 108       esac
 109       ;;
 110   esac
 111   return $rc
 112 }
 113
 114 localp () {
 115   h=$1
 116   ## Answer whether H is a local host.
 117
 118   case $h in
 119     "$thishost") return 0 ;;
 120     *) return 1 ;;
 121   esac
 122 }
 123
 124 hostrun () {
 125   tag=$1 cmd=$2
 126   ## Run CMD on the current host.  If the host seems local then run the
 127   ## command through a local shell; otherwise run it through ssh(1).  Either
 128   ## way it will be processed by a shell.
 129
 130   if localp $host; then run "@$host: $tag" sh -c "$cmd"
 131   else run "@$host: $tag" ssh $userat$host "$cmd"
 132   fi
 133 }
 134
 135 _hostrun () {
 136   h=$1 cmd=$2
 137   ## Like hostrun, but without the complicated logging, and targetted at a
 138   ## specific host.
 139
 140   if localp $h; then sh -c "$cmd"
 141   else ssh $h "$cmd"
 142   fi
 143 }
 144
 145 hostpath () {
 146   path=$1
 147   ## Output (to stdout) either PATH or HOST:PATH, choosing the former if the
 148   ## current host is local.
 149
 150   if localp $host; then echo $path
 151   else echo $userat$host:$path
 152   fi
 153 }
 154
 155 defhook () {
 156   hook=$1
 157   ## Define a hook called HOOK.
 158
 159   eval hk_$hook=
 160 }
 161
 162 addhook () {
 163   hook=$1 cmd=$2
 164   ## Add command CMD to the hook HOOK.
 165
 166   eval old=\$hk_$hook; new="$old $cmd"
 167   eval hk_$hook=\$new
 168 }
 169
 170 runhook () {
 171   hook=$1; shift 1
 172   ## Invoke HOOK, passing it the remaining arguments.
 173
 174   eval cmds=\$hk_$hook
 175   for cmd in $cmds; do
 176     if ! $cmd "$@"; then return $?; fi
 177   done
 178 }
 179
 180 ###--------------------------------------------------------------------------
 181 ### Database operations.
 182
 183 insert_index () {
 184   host=$1 fs=$2 date=$3 vol=$4
 185
 186   if [ -f "$INDEXDB" ]; then
 187     sqlite3 "$INDEXDB" <<EOF
 188 INSERT INTO idx (host, fs, date, vol)
 189         VALUES ('$host', '$fs', '$date', '$vol');
 190 EOF
 191   fi
 192 }
 193
 194 delete_index () {
 195   host=$1 fs=$2 date=$3
 196
 197   if [ -f "$INDEXDB" ]; then
 198     sqlite3 "$INDEXDB" <<EOF
 199 DELETE FROM idx WHERE
 200         host = '$host' AND fs = '$fs' AND date = '$date';
 201 EOF
 202   fi
 203 }
 204
 205 ###--------------------------------------------------------------------------
 206 ### Snapshot handling.
 207
 208 ## Snapshot protocol.  Each snapshot type has a pair of functions snap_TYPE
 209 ## and unsnap_TYPE.  Each is given the current snapshot arguments and the
 210 ## filesystem name to back up.  The snap_TYPE function should create and
 211 ## mount the snapshot and output an rsync(1) path to where the filesystem can
 212 ## be copied; the unsnap_TYPE function should unmount and tear down the
 213 ## snapshot.
 214
 215 ## Fake snapshot by not doing anything.  Use only if you have no choice.
 216 snap_live () { hostpath "$2"; }
 217 unsnap_live () { :; }
 218
 219 ## Fake snapshot by remounting a live filesystem read-only.  Useful if the
 220 ## underlying storage isn't in LVM.
 221
 222 snap_ro () {
 223   fs=$1 mnt=$2
 224
 225   ## Place a marker in the filesystem so we know why it was made readonly.
 226   ## (Also this serves to ensure that the filesystem was writable before.)
 227   hostrun "snap-ro $mnt" "
 228         echo rsync-backup >$mnt/.lock
 229         mount -oremount,ro $mnt" || return $?
 230
 231   ## Done.
 232   hostpath $mnt
 233 }
 234
 235 unsnap_ro () {
 236   fs=$1 mnt=$2
 237
 238   ## Check that the filesystem still has our lock marker.
 239   hostrun "unsnap-ro $mnt" "
 240         case \$(cat $mnt/.lock) in
 241           rsync-backup) ;;
 242           *) echo unlocked by someone else; exit 31 ;;
 243         esac
 244         mount -oremount,rw $mnt
 245         rm $mnt/.lock" || return $?
 246 }
 247
 248 ## Snapshot using LVM.
 249
 250 SNAPSIZE="-l10%ORIGIN"
 251
 252 snap_lvm () {
 253   vg=$1 lv=$2
 254
 255   ## Make the snapshot.
 256   hostrun "snap-lvm $vg/$lv" "
 257         lvcreate --snapshot -n$lv.bkp $SNAPSIZE $vg/$lv
 258         mkdir -p $SNAPDIR/$lv
 259         mount -oro /dev/$vg/$lv.bkp $SNAPDIR/$lv" || return $?
 260
 261   ## Done.
 262   hostpath $SNAPDIR/$lv
 263 }
 264
 265 unsnap_lvm () {
 266   vg=$1 lv=$2
 267
 268   ## Remove the snapshot.  Sometimes LVM doesn't notice that the snapshot is
 269   ## no longer in open immdiately, so try several times.
 270   hostrun "unsnap-lvm $vg/$lv" "
 271         umount $SNAPDIR/$lv
 272         rc=1
 273         for i in 1 2 3 4; do
 274           if lvremove -f $vg/$lv.bkp; then rc=0; break; fi
 275           sleep 2
 276         done
 277         exit $rc" || return $?
 278 }
 279
 280 ## Complicated snapshot using LVM, where the volume group and filesystem are
 281 ## owned by different machines, so they need to be synchronized during the
 282 ## snapshot.
 283
 284 do_rfreezefs () {
 285   lvhost=$1 vg=$2 lv=$3 fshost=$4 fsdir=$5
 286
 287   ## Engage in the rfreezefs protocol with the filesystem host.  This
 288   ## involves some hairy plumbing.  We want to get exit statuses out of both
 289   ## halves.
 290   set +e
 291   ssh $fshost rfreezefs $fsdir | {
 292     set -e
 293
 294     ## Read the codebook from the remote end.
 295     ready=nil
 296     while read line; do
 297       set -- $line
 298       case "$1" in
 299         PORT) port=$2 ;;
 300         TOKEN) eval tok_$2=$3 ;;
 301         READY) ready=t; break ;;
 302         *)
 303           echo >&2 "$quis: unexpected keyword $1 (rfreezefs to $rhost)"
 304           exit 1
 305           ;;
 306       esac
 307     done
 308     case $ready in
 309       nil)
 310         echo >&2 "$quis: unexpected eof (rfreezefs to $rhost)"
 311         exit 1
 312         ;;
 313     esac
 314
 315     ## Connect to the filesystem host's TCP port and get it to freeze its
 316     ## filesystem.
 317     exec 3<>/dev/tcp/$fshost/$port
 318     echo $tok_FREEZE >&3
 319     read tok <&3
 320     case $tok in
 321       "$tok_FROZEN") ;;
 322       *)
 323         echo >&2 "$quis: unexpected token $tok (rfreezefs $fsdir on $fshost)"
 324         exit 1
 325         ;;
 326     esac
 327
 328     ## Get the volume host to create the snapshot.
 329     set +e
 330     _hostrun >&2 3>&- $userat$lvhost \
 331       "lvcreate --snapshot -n$lv.bkp $SNAPSIZE $vg/$lv"
 332     snaprc=$?
 333     set -e
 334
 335     ## The filesystem can thaw now.
 336     echo $tok_THAW >&3
 337     read tok <&3
 338     case $tok in
 339       "$tok_THAWED") ;;
 340       *)
 341         _hostrun >&2 3>&- $userat$lvhost "lvremove -f $vg/$lv.bkp" || :
 342         echo >&2 "$quis: unexpected token $tok (rfreezefs $fsdir on $fshost)"
 343         exit 1
 344         ;;
 345     esac
 346
 347     ## Done.
 348     exit $snaprc
 349   }
 350
 351   ## Sift through the wreckage to find out what happened.
 352   rc_rfreezefs=${PIPESTATUS[0]} rc_snapshot=${PIPESTATUS[1]}
 353   set -e
 354   case $rc_rfreezefs:$rc_snapshot in
 355     0:0)
 356       ;;
 357     112:*)
 358       echo >&2 "$quis: EMERGENCY failed to thaw $fsdir on $fshost!"
 359       exit 112
 360       ;;
 361     *)
 362       echo >&2 "$quis: failed to snapshot $vg/$lv ($fsdir on $fshost)"
 363       exit 1
 364       ;;
 365   esac
 366
 367   ## Mount the snapshot on the volume host.
 368   _hostrun >&2 $userat$lvhost "
 369         mkdir -p $SNAPDIR/$lv
 370         mount -oro /dev/$vg/$lv.bkp $SNAPDIR/$lv"
 371 }
 372
 373 snap_rfreezefs () {
 374   rhost=$1 vg=$2 lv=$3 rfs=$4
 375
 376   set -e
 377   run "snap-rfreezefs $host:$vg/$lv $rhost:$rfs" \
 378     do_rfreezefs $host $vg $lv $rhost $rfs || return $?
 379   hostpath $SNAPDIR/$lv
 380 }
 381
 382 unsnap_rfreezefs () {
 383
 384   ## Unshapping is the same as for plain LVM.
 385   rhost=$1 vg=$2 lv=$3 rfs=$4
 386   unsnap_lvm $vg $lv
 387 }
 388
 389 ###--------------------------------------------------------------------------
 390 ### Expiry computations.
 391
 392 expire () {
 393   ## Read dates on stdin; write to stdout `EXPIRE date' for dates which
 394   ## should be expired and `RETAIN date' for dates which should be retained.
 395
 396   ## Get the current date and convert it into useful forms.
 397   now=$(date +%Y-%m-%d)
 398   parsedate $now
 399   now_jdn=$(julian $now) now_year=$year now_month=$month now_day=$day
 400   kept=:
 401
 402   ## Work through each date in the input.
 403   while read date; do
 404     keep=nil
 405
 406     ## Convert the date into a useful form.
 407     jdn=$(julian $date)
 408     parsedate $date
 409
 410     ## Work through the policy list.
 411     if [ $jdn -le $now_jdn ]; then
 412       while read ival age; do
 413
 414         ## Decide whether the policy entry applies to this date.
 415         apply=nil
 416         case $age in
 417           forever)
 418             apply=t
 419             ;;
 420           year)
 421             if [ $year -eq $now_year ] ||
 422                ([ $year -eq $(( $now_year - 1 )) ] &&
 423                 [ $month -ge $now_month ])
 424             then apply=t; fi
 425             ;;
 426           month)
 427             if ([ $month -eq $now_month ] && [ $year -eq $now_year ]) ||
 428                ((([ $month -eq $(( $now_month - 1 )) ] &&
 429                   [ $year -eq $now_year ]) ||
 430                  ([ $month -eq 12 ] && [ $now_month -eq 1 ] &&
 431                   [ $year -eq $(( $now_year - 1 )) ])) &&
 432                 [ $day -ge $now_day ])
 433             then apply=t; fi
 434             ;;
 435           week)
 436             if [ $jdn -ge $(( $now_jdn - 7 )) ]; then apply=t; fi
 437             ;;
 438           *)
 439             echo >&2 "$quis: unknown age symbol \`$age'"
 440             exit 1
 441             ;;
 442         esac
 443         case $apply in nil) continue ;; esac
 444
 445         ## Find the interval marker for this date.
 446         case $ival in
 447           daily)
 448             marker=$date
 449             ;;
 450           weekly)
 451             ydn=$(julian $year-01-01)
 452             wk=$(( ($jdn - $ydn)/7 + 1 ))
 453             marker=$year-w$wk
 454             ;;
 455           monthly)
 456             marker=$year-$month
 457             ;;
 458           annually | yearly)
 459             marker=$year
 460             ;;
 461           *)
 462             echo >&2 "$quis: unknown interval symbol \`$ival'"
 463             exit 1
 464             ;;
 465         esac
 466
 467         ## See if we've alredy retained something in this interval.
 468         case $kept in
 469           *:"$marker":*) ;;
 470           *) keep=t kept=$kept$marker: ;;
 471         esac
 472
 473       done <<EOF
 474 $expire_policy
 475 EOF
 476     fi
 477
 478     case $keep in
 479       t) echo RETAIN $date ;;
 480       *) echo EXPIRE $date ;;
 481     esac
 482
 483   done
 484 }
 485
 486 ###--------------------------------------------------------------------------
 487 ### Actually taking backups of filesystems.
 488
 489 MAXLOG=14
 490 HASH=sha256
 491 unset VOLUME
 492
 493 bkprc=0
 494
 495 remote_fshash () {
 496   _hostrun $userat$host "
 497         umask 077
 498         mkdir -p $fshashdir
 499         cd ${snapmnt#*:}
 500         echo \"*** $host $fs $date\"; echo
 501         rsync -rx --filter='dir-merge .rsync-backup' ./ |
 502           fshash -c$fshashdir/$fs.bkp -a -H$HASH -frsync
 503   " >new.fshash
 504 }
 505
 506 local_fshash () {
 507   { echo "*** $host $fs $date"; echo
 508     fshash -c$STOREDIR/fshash.cache -H$HASH new/
 509   } >$localmap
 510 }
 511
 512 expire_backups () {
 513   { seen=:
 514     for i in *-*-*; do
 515       i=${i%%.*}
 516       case $i in *[!-0-9]*) continue ;; esac
 517       case $seen in *:"$i":*) continue ;; esac
 518       seen=$seen$i:
 519       echo $i
 520     done; } |
 521   expire |
 522   while read op date; do
 523     case $op,$dryrun in
 524       RETAIN,t)
 525         echo >&2 "              --- keep   $date"
 526         ;;
 527       EXPIRE,t)
 528         echo >&2 "              --- delete $date"
 529         ;;
 530       RETAIN,nil)
 531         echo "keep   $date"
 532         ;;
 533       EXPIRE,nil)
 534         echo "delete $date"
 535         $verbose -n "   expire $date..."
 536         rm -rf $date $date.*
 537         delete_index $host $fs $date
 538         $verbose " done"
 539         ;;
 540     esac
 541   done
 542 }
 543
 544 ## Backup hooks.
 545 defhook setup
 546 defhook precommit
 547 defhook postcommit
 548
 549 backup_precommit_hook () {
 550   host=$1 fs=$2 date=$3
 551   ## Compatibility: You can override this hook in the configuration file for
 552   ## special effects; but it's better to use `addhook precommit'.
 553
 554   :
 555 }
 556 addhook precommit backup_precommit_hook
 557
 558 backup_commit_hook () {
 559   host=$1 fs=$2 date=$3
 560   ## Compatibility: You can override this hook in the configuration file for
 561   ## special effects; but it's better to use `addhook commit'.
 562
 563   :
 564 }
 565 addhook commit backup_commit_hook
 566
 567 do_backup () {
 568   date=$1 fs=$2 fsarg=$3
 569   ## Back up FS on the current host.
 570
 571   set -e
 572   attempt=0
 573
 574   ## Run a hook beforehand.
 575   set +e; runhook setup $host $fs $date; rc=$?; set -e
 576   case $? in
 577     0) ;;
 578     99) log "BACKUP of $host:$fs SKIPPED by hook"; return 0 ;;
 579     *) log "BACKUP of $host:$fs FAILED (hook returns $?)"; return $? ;;
 580   esac
 581
 582   ## Report the start of this attempt.
 583   log "START BACKUP of $host:$fs"
 584
 585   ## Maybe we need to retry the backup.
 586   while :; do
 587
 588     ## Create and mount the remote snapshot.
 589     case $dryrun in
 590       t)
 591         maybe snap_$snap $fs $fsarg
 592         snapmnt="<snapshot>"
 593         ;;
 594       nil)
 595         snapmnt=$(snap_$snap $snapargs $fs $fsarg) || return $?
 596         ;;
 597     esac
 598     $verbose "  create snapshot"
 599
 600     ## Build the list of hardlink sources.
 601     linkdests=""
 602     for i in $host $like; do
 603       d=$STOREDIR/$i/$fs/last/
 604       if [ -d $d ]; then linkdests="$linkdests --link-dest=$d"; fi
 605     done
 606
 607     ## Copy files from the remote snapshot.
 608     maybe mkdir -p new/
 609     case $dryrun in
 610       t) $verbose "     running rsync" ;;
 611       nil) $verbose -n "        running rsync..." ;;
 612     esac
 613     set +e
 614     run "RSYNC of $host:$fs (snapshot on $snapmnt)" do_rsync \
 615       $linkdests \
 616       $rsyncargs \
 617       $snapmnt/ new/
 618     rc_rsync=$?
 619     set -e
 620     case $dryrun in nil) $verbose " done" ;; esac
 621
 622     ## Collect a map of the snapshot for verification purposes.
 623     set +e
 624     case $dryrun in
 625       t) $verbose "     remote fshash" ;;
 626       nil) $verbose -n "        remote fshash..." ;;
 627     esac
 628     run "@$host: fshash $fs" remote_fshash
 629     rc_fshash=$?
 630     set -e
 631     case $dryrun in nil) $verbose " done" ;; esac
 632
 633     ## Remove the snapshot.
 634     maybe unsnap_$snap $snapargs $fs $fsarg
 635     $verbose "  remove snapshot"
 636
 637     ## If we failed to copy, then give up.
 638     case $rc_rsync:$rc_fshash in
 639       0:0) ;;
 640       0:*) return $rc_fshash ;;
 641       *) return $rc_rsync ;;
 642     esac
 643
 644     ## Get a matching map of the files received.
 645     maybe mkdir -m750 -p $STOREDIR/tmp/
 646     localmap=$STOREDIR/tmp/fshash.$host.$fs.$date
 647     case $dryrun in
 648       t) $verbose "     local fshash" ;;
 649       nil) $verbose -n "        local fshash..." ;;
 650     esac
 651     run "local fshash $host:$fs" local_fshash || return $?
 652     case $dryrun in nil) $verbose " done" ;; esac
 653
 654     ## Compare the two maps.
 655     set +e
 656     run "compare fshash maps for $host:$fs" diff -u new.fshash $localmap
 657     rc_diff=$?
 658     set -e
 659     case $rc_diff in
 660       0)
 661         break
 662         ;;
 663       1)
 664         if [ $attempt -ge $retry ]; then return $rc; fi
 665         $verbose "      fshash mismatch; retrying"
 666         attempt=$(( $attempt + 1 ))
 667         ;;
 668       *)
 669         return $rc_diff
 670         ;;
 671     esac
 672   done
 673
 674   ## Glorious success.
 675   maybe rm -f $localmap
 676   $verbose "    fshash match"
 677
 678   ## Commit this backup.
 679   case $dryrun in
 680     nil)
 681       runhook precommit $host $fs $date
 682       mv new $date
 683       mv new.fshash $date.fshash
 684       insert_index $host $fs $date $VOLUME
 685       runhook commit $host $fs $date
 686       mkdir hack
 687       ln -s $date hack/last
 688       mv hack/last .
 689       rmdir hack
 690       ;;
 691   esac
 692   $verbose "    commit"
 693
 694   ## Expire old backups.
 695   case "${expire_policy+t},${default_policy+t}" in
 696     ,t) expire_policy=$default_policy ;;
 697   esac
 698   case "${expire_policy+t},$dryrun" in
 699     t,nil) run "expiry for $host:$fs" expire_backups ;;
 700     t,t) expire_backups ;;
 701   esac
 702   clear_policy=t
 703
 704   ## Report success.
 705   case $dryrun in
 706     t) log "END BACKUP of $host:$fs" ;;
 707     nil) log "SUCCESSFUL BACKUP of $host:$fs" ;;
 708   esac
 709 }
 710
 711 run_backup_cmd () {
 712   fs=$1 date=$2 cmd=$3; shift 3
 713   ## try_backup FS DATE COMMAND ARGS ...
 714   ##
 715   ## Run COMMAND ARGS to back up filesystem FS on the current host,
 716   ## maintaining a log, and checking whether it worked.  The caller has
 717   ## usually worked out the DATE in order to set up the filesystem, and we
 718   ## need it to name the log file properly.
 719
 720   ## Find a name for the log file.  In unusual circumstances, we may have
 721   ## deleted old logs from today, so just checking for an unused sequence
 722   ## number is insufficient.  Instead, check all of the logfiles for today,
 723   ## and use a sequence number that's larger than any of them.
 724   case $dryrun in
 725     t)
 726       log=/dev/null
 727       ;;
 728     nil)
 729       seq=1
 730       for i in "$logdir/$host/$fs.$date#"*; do
 731         tail=${i##*#}
 732         case "$tail" in [!1-9]* | *[!0-9]*) continue ;; esac
 733         if [ -f "$i" -a $tail -ge $seq ]; then seq=$(( tail + 1 )); fi
 734       done
 735       log="$logdir/$host/$fs.$date#$seq"
 736       ;;
 737   esac
 738
 739   ## Run the backup command.
 740   case $dryrun in nil) mkdir -p $logdir/$host ;; esac
 741   if ! "$cmd" "$@" 9>$log 1>&9; then
 742     echo >&2
 743     echo >&2 "$quis: backup of $host:$fs FAILED!"
 744     bkprc=1
 745   fi
 746
 747   ## Count up the logfiles.
 748   nlog=0
 749   for i in "$logdir/$host/$fs".*; do
 750     if [ ! -f "$i" ]; then continue; fi
 751     nlog=$(( nlog + 1 ))
 752   done
 753
 754   ## If there are too many, go through and delete some early ones.
 755   if [ $dryrun = nil ] && [ $nlog -gt $MAXLOG ]; then
 756     n=$(( nlog - MAXLOG ))
 757     for i in "$logdir/$host/$fs".*; do
 758       if [ ! -f "$i" ]; then continue; fi
 759       rm -f "$i"
 760       n=$(( n - 1 ))
 761       if [ $n -eq 0 ]; then break; fi
 762     done
 763   fi
 764 }
 765
 766 backup () {
 767   ## backup FS[:ARG] ...
 768   ##
 769   ## Back up the filesystems on the currently selected host using the
 770   ## currently selected snapshot type.
 771
 772   ## Make sure that there's a store volume.  We must do this here rather than
 773   ## in the main body of the script, since the configuration file needs a
 774   ## chance to override STOREDIR.
 775   if ! [ -r $STOREDIR/.rsync-backup-store ]; then
 776     echo >&2 "$quis: no backup volume mounted"
 777     exit 15
 778   fi
 779
 780   ## Read the volume name if we don't have one already.  Again, this allows
 781   ## the configuration file to provide a volume name.
 782   case "${VOLUME+t}${VOLUME-nil}" in
 783     nil) VOLUME=$(cat $METADIR/volume) ;;
 784   esac
 785
 786   ## Back up each requested file system in turn.
 787   for fs in "$@"; do
 788
 789     ## Parse the argument.
 790     case $fs in
 791       *:*) fsarg=${fs#*:} fs=${fs%%:*} ;;
 792       *) fsarg="" ;;
 793     esac
 794     $verbose "  filesystem $fs"
 795
 796     ## Move to the store directory and set up somewhere to put this backup.
 797     cd $STOREDIR
 798     case $dryrun in
 799       nil)
 800         if [ ! -d $host ]; then
 801           mkdir -m755 $host
 802           chown root:root $host
 803         fi
 804         if [ ! -d $host/$fs ]; then
 805           mkdir -m750 $host/$fs
 806           chown root:backup $host/$fs
 807         fi
 808         ;;
 809     esac
 810     cd $host/$fs
 811
 812     ## Find out if we've already copied this filesystem today.
 813     date=$(date +%Y-%m-%d)
 814     if [ $dryrun = nil ] && [ -d $date ]; then
 815       $verbose "        already dumped"
 816       continue
 817     fi
 818
 819     ## Do the backup of this filesystem.
 820     run_backup_cmd $fs $date do_backup $date $fs $fsarg
 821   done
 822 }
 823
 824 ###--------------------------------------------------------------------------
 825 ### Configuration functions.
 826
 827 defhook start
 828 defhook end
 829
 830 done_first_host_p=nil
 831
 832 host () {
 833   host=$1
 834   like= userat=
 835   case $done_first_host_p in
 836     nil) runhook start; done_first_host_p=t ;;
 837   esac
 838   case "${expire_policy+t},${default_policy+t}" in
 839     t,) default_policy=$expire_policy ;;
 840   esac
 841   unset expire_policy
 842   $verbose "host $host"
 843 }
 844
 845 snaptype () { snap=$1; shift; snapargs="$*"; retry=0; }
 846 rsyncargs () { rsyncargs="$*"; }
 847 like () { like="$*"; }
 848 retry () { retry="$*"; }
 849 user () { userat="$*@"; }
 850
 851 retain () {
 852   case $clear_policy in t) unset expire_policy; clear_policy=nil ;; esac
 853   expire_policy="${expire_policy+$expire_policy
 854 }$*"
 855 }
 856
 857 ###--------------------------------------------------------------------------
 858 ### Read the configuration and we're done.
 859
 860 usage () {
 861   echo "usage: $quis [-nv] [-c CONF]"
 862 }
 863
 864 version () {
 865   echo "$quis version $VERSION"
 866 }
 867
 868 whine () { echo >&8 "$@"; }
 869
 870 while getopts "hVvc:n" opt; do
 871   case "$opt" in
 872     h) usage; exit 0 ;;
 873     V) version; config; exit 0 ;;
 874     v) verbose=whine ;;
 875     c) conf=$OPTARG ;;
 876     n) dryrun=t ;;
 877     *) exit 1 ;;
 878   esac
 879 done
 880 shift $((OPTIND - 1))
 881 case $# in 0) ;; *) usage >&2; exit 1 ;; esac
 882 exec 8>&1
 883
 884 . "$conf"
 885
 886 runhook end $bkprc
 887 case "$bkprc" in
 888   0) $verbose "All backups successful" ;;
 889   *) $verbose "Backups FAILED" ;;
 890 esac
 891
 892 ###----- That's all, folks --------------------------------------------------
 893
 894 exit $bkprc