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
  31 VERSION=@VERSION@
  32 mntbkpdir=@mntbkpdir@
  33 logdir=@logdir@
  34 fshashdir=@fshashdir@
  35 conf=@sysconfdir@/rsync-backup.conf
  36
  37 verbose=:
  38 dryrun=nil
  39
  40 ###--------------------------------------------------------------------------
  41 ### Utility functions.
  42
  43 RSYNCOPTS="--verbose"
  44
  45 do_rsync () {
  46   ## Run rsync(1) in an appropriate manner.  Configuration should ovrride
  47   ## this or set $RSYNCOPTS if it wants to do something weirder.  Arguments
  48   ## to this function are passed on to rsync.
  49
  50   rsync \
  51         --archive --hard-links --numeric-ids --del \
  52         --sparse --compress \
  53         --one-file-system \
  54         --partial \
  55         $RSYNCOPTS \
  56         --filter="dir-merge .rsync-backup" \
  57         "$@"
  58 }
  59
  60 log () {
  61   case $dryrun in
  62     t)
  63       echo >&2 "                *** $*"
  64       ;;
  65     nil)
  66       now=$(date +"%Y-%m-%d %H:%M:%S %z")
  67       echo >&9 "$now $*"
  68       ;;
  69   esac
  70 }
  71
  72 maybe () {
  73   ## Run CMD, if this isn't a dry run.
  74
  75   case $dryrun in
  76     t) echo >&2 "               +++ $*" ;;
  77     nil) "$@" ;;
  78   esac
  79 }
  80
  81 copy () {
  82   prefix=$1
  83   ## Copy lines from stdin to stdout, adding PREFIX.
  84
  85   while IFS= read -r line; do
  86     printf "%s %s\n" "$prefix" "$line"
  87   done
  88 }
  89
  90 run () {
  91   tag=$1 cmd=$2; shift 2
  92   ## Run CMD, logging its output in a pleasing manner.
  93
  94   case $dryrun in
  95     t)
  96       echo >&2 "                *** RUN $tag"
  97       echo >&2 "                +++ $cmd $*"
  98       rc=0
  99       ;;
 100     nil)
 101       log "BEGIN $tag"
 102       rc=$(
 103         { { { ( set +e
 104                 "$cmd" "$@" 3>&- 4>&- 5>&- 9>&-
 105                 echo $? >&5; ) |
 106               copy "|" >&4; } 2>&1 |
 107             copy "*" >&4; } 4>&1 |
 108           cat >&9; } 5>&1 </dev/null
 109       )
 110       case $rc in
 111         0) log "END $tag" ;;
 112         *) log "FAIL $tag (rc = $rc)" ;;
 113       esac
 114       ;;
 115   esac
 116   return $rc
 117 }
 118
 119 localp () {
 120   h=$1
 121   ## Answer whether H is a local host.
 122
 123   case $h in
 124     "$thishost") return 0 ;;
 125     *) return 1 ;;
 126   esac
 127 }
 128
 129 hostrun () {
 130   tag=$1 cmd=$2
 131   ## Run CMD on the current host.  If the host seems local then run the
 132   ## command through a local shell; otherwise run it through ssh(1).  Either
 133   ## way it will be processed by a shell.
 134
 135   if localp $host; then run "@$host: $tag" sh -c "$cmd"
 136   else run "@$host: $tag" ssh $userat$host "$cmd"
 137   fi
 138 }
 139
 140 _hostrun () {
 141   h=$1 cmd=$2
 142   ## Like hostrun, but without the complicated logging, and targetted at a
 143   ## specific host.
 144
 145   if localp $h; then sh -c "$cmd"
 146   else ssh $h "$cmd"
 147   fi
 148 }
 149
 150 hostpath () {
 151   path=$1
 152   ## Output (to stdout) either PATH or HOST:PATH, choosing the former if the
 153   ## current host is local.
 154
 155   if localp $host; then echo $path
 156   else echo $userat$host:$path
 157   fi
 158 }
 159
 160 defhook () {
 161   hook=$1
 162   ## Define a hook called HOOK.
 163
 164   eval hk_$hook=
 165 }
 166
 167 addhook () {
 168   hook=$1 cmd=$2
 169   ## Add command CMD to the hook HOOK.
 170
 171   eval old=\$hk_$hook; new="$old $cmd"
 172   eval hk_$hook=\$new
 173 }
 174
 175 runhook () {
 176   hook=$1; shift 1
 177   ## Invoke HOOK, passing it the remaining arguments.
 178
 179   eval cmds=\$hk_$hook
 180   for cmd in $cmds; do
 181     if ! $cmd "$@"; then return $?; fi
 182   done
 183 }
 184
 185 ###--------------------------------------------------------------------------
 186 ### Database operations.
 187
 188 INDEXDB=@pkglocalstatedir@/index.db
 189
 190 insert_index () {
 191   host=$1 fs=$2 date=$3 vol=$4
 192
 193   if [ -f "$INDEXDB" ]; then
 194     sqlite3 "$INDEXDB" <<EOF
 195 INSERT INTO idx (host, fs, date, vol)
 196         VALUES ('$host', '$fs', '$date', '$vol');
 197 EOF
 198   fi
 199 }
 200
 201 delete_index () {
 202   host=$1 fs=$2 date=$3
 203
 204   if [ -f "$INDEXDB" ]; then
 205     sqlite3 "$INDEXDB" <<EOF
 206 DELETE FROM idx WHERE
 207         host = '$host' AND fs = '$fs' AND date = '$date';
 208 EOF
 209   fi
 210 }
 211
 212 ###--------------------------------------------------------------------------
 213 ### Snapshot handling.
 214
 215 ## Snapshot protocol.  Each snapshot type has a pair of functions snap_TYPE
 216 ## and unsnap_TYPE.  Each is given the current snapshot arguments and the
 217 ## filesystem name to back up.  The snap_TYPE function should create and
 218 ## mount the snapshot and output an rsync(1) path to where the filesystem can
 219 ## be copied; the unsnap_TYPE function should unmount and tear down the
 220 ## snapshot.
 221
 222 ## Fake snapshot by not doing anything.  Use only if you have no choice.
 223 snap_live () { hostpath "$2"; }
 224 unsnap_live () { :; }
 225
 226 ## Fake snapshot by remounting a live filesystem read-only.  Useful if the
 227 ## underlying storage isn't in LVM.
 228
 229 snap_ro () {
 230   fs=$1 mnt=$2
 231
 232   ## Place a marker in the filesystem so we know why it was made readonly.
 233   ## (Also this serves to ensure that the filesystem was writable before.)
 234   hostrun "snap-ro $mnt" "
 235         echo rsync-backup >$mnt/.lock
 236         mount -oremount,ro $mnt" || return $?
 237
 238   ## Done.
 239   hostpath $mnt
 240 }
 241
 242 unsnap_ro () {
 243   fs=$1 mnt=$2
 244
 245   ## Check that the filesystem still has our lock marker.
 246   hostrun "unsnap-ro $mnt" "
 247         case \$(cat $mnt/.lock) in
 248           rsync-backup) ;;
 249           *) echo unlocked by someone else; exit 31 ;;
 250         esac
 251         mount -oremount,rw $mnt
 252         rm $mnt/.lock" || return $?
 253 }
 254
 255 ## Snapshot using LVM.
 256
 257 SNAPSIZE="-l10%ORIGIN"
 258 SNAPDIR=@mntbkpdir@/snap
 259
 260 snap_lvm () {
 261   vg=$1 lv=$2
 262
 263   ## Make the snapshot.
 264   hostrun "snap-lvm $vg/$lv" "
 265         lvcreate --snapshot -n$lv.bkp $SNAPSIZE $vg/$lv
 266         mkdir -p $SNAPDIR/$lv
 267         mount -oro /dev/$vg/$lv.bkp $SNAPDIR/$lv" || return $?
 268
 269   ## Done.
 270   hostpath $SNAPDIR/$lv
 271 }
 272
 273 unsnap_lvm () {
 274   vg=$1 lv=$2
 275
 276   ## Remove the snapshot.  Sometimes LVM doesn't notice that the snapshot is
 277   ## no longer in open immdiately, so try several times.
 278   hostrun "unsnap-lvm $vg/$lv" "
 279         umount $SNAPDIR/$lv
 280         rc=1
 281         for i in 1 2 3 4; do
 282           if lvremove -f $vg/$lv.bkp; then rc=0; break; fi
 283           sleep 2
 284         done
 285         exit $rc" || return $?
 286 }
 287
 288 ## Complicated snapshot using LVM, where the volume group and filesystem are
 289 ## owned by different machines, so they need to be synchronized during the
 290 ## snapshot.
 291
 292 do_rfreezefs () {
 293   lvhost=$1 vg=$2 lv=$3 fshost=$4 fsdir=$5
 294
 295   ## Engage in the rfreezefs protocol with the filesystem host.  This
 296   ## involves some hairy plumbing.  We want to get exit statuses out of both
 297   ## halves.
 298   set +e
 299   ssh $fshost rfreezefs $fsdir | {
 300     set -e
 301
 302     ## Read the codebook from the remote end.
 303     ready=nil
 304     while read line; do
 305       set -- $line
 306       case "$1" in
 307         PORT) port=$2 ;;
 308         TOKEN) eval tok_$2=$3 ;;
 309         READY) ready=t; break ;;
 310         *)
 311           echo >&2 "$quis: unexpected keyword $1 (rfreezefs to $rhost)"
 312           exit 1
 313           ;;
 314       esac
 315     done
 316     case $ready in
 317       nil)
 318         echo >&2 "$quis: unexpected eof (rfreezefs to $rhost)"
 319         exit 1
 320         ;;
 321     esac
 322
 323     ## Connect to the filesystem host's TCP port and get it to freeze its
 324     ## filesystem.
 325     exec 3<>/dev/tcp/$fshost/$port
 326     echo $tok_FREEZE >&3
 327     read tok <&3
 328     case $tok in
 329       "$tok_FROZEN") ;;
 330       *)
 331         echo >&2 "$quis: unexpected token $tok (rfreezefs $fsdir on $fshost)"
 332         exit 1
 333         ;;
 334     esac
 335
 336     ## Get the volume host to create the snapshot.
 337     set +e
 338     _hostrun >&2 3>&- $userat$lvhost \
 339       "lvcreate --snapshot -n$lv.bkp $SNAPSIZE $vg/$lv"
 340     snaprc=$?
 341     set -e
 342
 343     ## The filesystem can thaw now.
 344     echo $tok_THAW >&3
 345     read tok <&3
 346     case $tok in
 347       "$tok_THAWED") ;;
 348       *)
 349         _hostrun >&2 3>&- $userat$lvhost "lvremove -f $vg/$lv.bkp" || :
 350         echo >&2 "$quis: unexpected token $tok (rfreezefs $fsdir on $fshost)"
 351         exit 1
 352         ;;
 353     esac
 354
 355     ## Done.
 356     exit $snaprc
 357   }
 358
 359   ## Sift through the wreckage to find out what happened.
 360   rc_rfreezefs=${PIPESTATUS[0]} rc_snapshot=${PIPESTATUS[1]}
 361   set -e
 362   case $rc_rfreezefs:$rc_snapshot in
 363     0:0)
 364       ;;
 365     112:*)
 366       echo >&2 "$quis: EMERGENCY failed to thaw $fsdir on $fshost!"
 367       exit 112
 368       ;;
 369     *)
 370       echo >&2 "$quis: failed to snapshot $vg/$lv ($fsdir on $fshost)"
 371       exit 1
 372       ;;
 373   esac
 374
 375   ## Mount the snapshot on the volume host.
 376   _hostrun >&2 $userat$lvhost "
 377         mkdir -p $SNAPDIR/$lv
 378         mount -oro /dev/$vg/$lv.bkp $SNAPDIR/$lv"
 379 }
 380
 381 snap_rfreezefs () {
 382   rhost=$1 vg=$2 lv=$3 rfs=$4
 383
 384   set -e
 385   run "snap-rfreezefs $host:$vg/$lv $rhost:$rfs" \
 386     do_rfreezefs $host $vg $lv $rhost $rfs || return $?
 387   hostpath $SNAPDIR/$lv
 388 }
 389
 390 unsnap_rfreezefs () {
 391
 392   ## Unshapping is the same as for plain LVM.
 393   rhost=$1 vg=$2 lv=$3 rfs=$4
 394   unsnap_lvm $vg $lv
 395 }
 396
 397 ###--------------------------------------------------------------------------
 398 ### Expiry computations.
 399
 400 parsedate () {
 401   date=$1
 402   ## Parse an ISO8601 DATE, and set YEAR, MONTH, DAY appropriately (and
 403   ## without leading zeros).
 404
 405   ## Extract the components of the date and trim leading zeros (which will
 406   ## cause things to be interpreted as octal and fail).
 407   year=${date%%-*} rest=${date#*-}; month=${rest%%-*} day=${rest#*-}
 408   year=${year#0} month=${month#0} day=${day#0}
 409 }
 410
 411 julian () {
 412   date=$1
 413   ## Convert an ISO8601 DATE to a Julian Day Number.
 414
 415   parsedate $date
 416
 417   ## The actual calculation: convert a (proleptic) Gregorian calendar date
 418   ## into a Julian day number.  This is taken from Wikipedia's page
 419   ## http://en.wikipedia.org/wiki/Julian_day#Calculation but the commentary
 420   ## is mine.  The epoch is 4713BC-01-01 (proleptic) Julian, or 4714BC-11-24
 421   ## proleptic Gregorian.
 422
 423   ## If the MONTH is January or February then set a = 1, otherwise set a = 0.
 424   a=$(( (14 - $month)/12 ))
 425
 426   ## Compute a year offset relative to 4799BC-03-01.  This puts the leap day
 427   ## as the very last day in a year, which is very convenient.  The offset
 428   ## here is sufficient to make all y values positive (within the range of
 429   ## the JDN calendar), and is a multiple of 400, which is the Gregorian
 430   ## cycle length.
 431   y=$(( $year + 4800 - $a ))
 432
 433   ## Compute the offset month number in that year.  These months count from
 434   ## zero, not one.
 435   m=$(( $month + 12*$a - 3 ))
 436
 437   ## Now for the main event.  The (153 m + 2)/5 term is a surprising but
 438   ## correct trick for obtaining the number of days in the first m months of
 439   ## the (shifted) year).  The magic offset 32045 is what you get when you
 440   ## plug the proper JDN epoch (year = -4713, month = 11, day = 24) into the
 441   ## above machinery.
 442   jdn=$(( $day + (153*$m + 2)/5 + 365*$y + $y/4 - $y/100 + $y/400 - 32045 ))
 443
 444   echo $jdn
 445 }
 446
 447 expire () {
 448   ## Read dates on stdin; write to stdout `EXPIRE date' for dates which
 449   ## should be expired and `RETAIN date' for dates which should be retained.
 450
 451   ## Get the current date and convert it into useful forms.
 452   now=$(date +%Y-%m-%d)
 453   parsedate $now
 454   now_jdn=$(julian $now) now_year=$year now_month=$month now_day=$day
 455   kept=:
 456
 457   ## Work through each date in the input.
 458   while read date; do
 459     keep=nil
 460
 461     ## Convert the date into a useful form.
 462     jdn=$(julian $date)
 463     parsedate $date
 464
 465     ## Work through the policy list.
 466     if [ $jdn -le $now_jdn ]; then
 467       while read ival age; do
 468
 469         ## Decide whether the policy entry applies to this date.
 470         apply=nil
 471         case $age in
 472           forever)
 473             apply=t
 474             ;;
 475           year)
 476             if [ $year -eq $now_year ] ||
 477                ([ $year -eq $(( $now_year - 1 )) ] &&
 478                 [ $month -ge $now_month ])
 479             then apply=t; fi
 480             ;;
 481           month)
 482             if ([ $month -eq $now_month ] && [ $year -eq $now_year ]) ||
 483                ((([ $month -eq $(( $now_month - 1 )) ] &&
 484                   [ $year -eq $now_year ]) ||
 485                  ([ $month -eq 12 ] && [ $now_month -eq 1 ] &&
 486                   [ $year -eq $(( $now_year - 1 )) ])) &&
 487                 [ $day -ge $now_day ])
 488             then apply=t; fi
 489             ;;
 490           week)
 491             if [ $jdn -ge $(( $now_jdn - 7 )) ]; then apply=t; fi
 492             ;;
 493           *)
 494             echo >&2 "$quis: unknown age symbol \`$age'"
 495             exit 1
 496             ;;
 497         esac
 498         case $apply in nil) continue ;; esac
 499
 500         ## Find the interval marker for this date.
 501         case $ival in
 502           daily)
 503             marker=$date
 504             ;;
 505           weekly)
 506             ydn=$(julian $year-01-01)
 507             wk=$(( ($jdn - $ydn)/7 + 1 ))
 508             marker=$year-w$wk
 509             ;;
 510           monthly)
 511             marker=$year-$month
 512             ;;
 513           annually | yearly)
 514             marker=$year
 515             ;;
 516           *)
 517             echo >&2 "$quis: unknown interval symbol \`$ival'"
 518             exit 1
 519             ;;
 520         esac
 521
 522         ## See if we've alredy retained something in this interval.
 523         case $kept in
 524           *:"$marker":*) ;;
 525           *) keep=t kept=$kept$marker: ;;
 526         esac
 527
 528       done <<EOF
 529 $expire_policy
 530 EOF
 531     fi
 532
 533     case $keep in
 534       t) echo RETAIN $date ;;
 535       *) echo EXPIRE $date ;;
 536     esac
 537
 538   done
 539 }
 540
 541 ###--------------------------------------------------------------------------
 542 ### Actually taking backups of filesystems.
 543
 544 STOREDIR=@mntbkpdir@/store
 545 METADIR=@mntbkpdir@/meta
 546 MAXLOG=14
 547 HASH=sha256
 548 unset VOLUME
 549
 550 bkprc=0
 551
 552 remote_fshash () {
 553   _hostrun $userat$host "
 554         umask 077
 555         mkdir -p $fshashdir
 556         cd ${snapmnt#*:}
 557         echo \"*** $host $fs $date\"; echo
 558         rsync -rx --filter='dir-merge .rsync-backup' ./ |
 559           fshash -c$fshashdir/$fs.bkp -a -H$HASH -frsync
 560   " >new.fshash
 561 }
 562
 563 local_fshash () {
 564   { echo "*** $host $fs $date"; echo
 565     fshash -c$STOREDIR/fshash.cache -H$HASH new/
 566   } >$localmap
 567 }
 568
 569 expire_backups () {
 570   { seen=:
 571     for i in *-*-*; do
 572       i=${i%%.*}
 573       case $i in *[!-0-9]*) continue ;; esac
 574       case $seen in *:"$i":*) continue ;; esac
 575       seen=$seen$i:
 576       echo $i
 577     done; } |
 578   expire |
 579   while read op date; do
 580     case $op,$dryrun in
 581       RETAIN,t)
 582         echo >&2 "              --- keep   $date"
 583         ;;
 584       EXPIRE,t)
 585         echo >&2 "              --- delete $date"
 586         ;;
 587       RETAIN,nil)
 588         echo "keep   $date"
 589         ;;
 590       EXPIRE,nil)
 591         echo "delete $date"
 592         $verbose -n "   expire $date..."
 593         rm -rf $date $date.*
 594         delete_index $host $fs $date
 595         $verbose " done"
 596         ;;
 597     esac
 598   done
 599 }
 600
 601 ## Backup hooks.
 602 defhook setup
 603 defhook precommit
 604 defhook postcommit
 605
 606 backup_precommit_hook () {
 607   host=$1 fs=$2 date=$3
 608   ## Compatibility: You can override this hook in the configuration file for
 609   ## special effects; but it's better to use `addhook precommit'.
 610
 611   :
 612 }
 613 addhook precommit backup_precommit_hook
 614
 615 backup_commit_hook () {
 616   host=$1 fs=$2 date=$3
 617   ## Compatibility: You can override this hook in the configuration file for
 618   ## special effects; but it's better to use `addhook commit'.
 619
 620   :
 621 }
 622 addhook commit backup_commit_hook
 623
 624 do_backup () {
 625   date=$1 fs=$2 fsarg=$3
 626   ## Back up FS on the current host.
 627
 628   set -e
 629   attempt=0
 630
 631   ## Run a hook beforehand.
 632   set +e; runhook setup $host $fs $date; rc=$?; set -e
 633   case $? in
 634     0) ;;
 635     99) log "BACKUP of $host:$fs SKIPPED by hook"; return 0 ;;
 636     *) log "BACKUP of $host:$fs FAILED (hook returns $?)"; return $? ;;
 637   esac
 638
 639   ## Report the start of this attempt.
 640   log "START BACKUP of $host:$fs"
 641
 642   ## Maybe we need to retry the backup.
 643   while :; do
 644
 645     ## Create and mount the remote snapshot.
 646     case $dryrun in
 647       t)
 648         maybe snap_$snap $fs $fsarg
 649         snapmnt="<snapshot>"
 650         ;;
 651       nil)
 652         snapmnt=$(snap_$snap $snapargs $fs $fsarg) || return $?
 653         ;;
 654     esac
 655     $verbose "  create snapshot"
 656
 657     ## Build the list of hardlink sources.
 658     linkdests=""
 659     for i in $host $like; do
 660       d=$STOREDIR/$i/$fs/last/
 661       if [ -d $d ]; then linkdests="$linkdests --link-dest=$d"; fi
 662     done
 663
 664     ## Copy files from the remote snapshot.
 665     maybe mkdir -p new/
 666     case $dryrun in
 667       t) $verbose "     running rsync" ;;
 668       nil) $verbose -n "        running rsync..." ;;
 669     esac
 670     set +e
 671     run "RSYNC of $host:$fs (snapshot on $snapmnt)" do_rsync \
 672       $linkdests \
 673       $rsyncargs \
 674       $snapmnt/ new/
 675     rc_rsync=$?
 676     set -e
 677     case $dryrun in nil) $verbose " done" ;; esac
 678
 679     ## Collect a map of the snapshot for verification purposes.
 680     set +e
 681     case $dryrun in
 682       t) $verbose "     remote fshash" ;;
 683       nil) $verbose -n "        remote fshash..." ;;
 684     esac
 685     run "@$host: fshash $fs" remote_fshash
 686     rc_fshash=$?
 687     set -e
 688     case $dryrun in nil) $verbose " done" ;; esac
 689
 690     ## Remove the snapshot.
 691     maybe unsnap_$snap $snapargs $fs $fsarg
 692     $verbose "  remove snapshot"
 693
 694     ## If we failed to copy, then give up.
 695     case $rc_rsync:$rc_fshash in
 696       0:0) ;;
 697       0:*) return $rc_fshash ;;
 698       *) return $rc_rsync ;;
 699     esac
 700
 701     ## Get a matching map of the files received.
 702     maybe mkdir -m750 -p $STOREDIR/tmp/
 703     localmap=$STOREDIR/tmp/fshash.$host.$fs.$date
 704     case $dryrun in
 705       t) $verbose "     local fshash" ;;
 706       nil) $verbose -n "        local fshash..." ;;
 707     esac
 708     run "local fshash $host:$fs" local_fshash || return $?
 709     case $dryrun in nil) $verbose " done" ;; esac
 710
 711     ## Compare the two maps.
 712     set +e
 713     run "compare fshash maps for $host:$fs" diff -u new.fshash $localmap
 714     rc_diff=$?
 715     set -e
 716     case $rc_diff in
 717       0)
 718         break
 719         ;;
 720       1)
 721         if [ $attempt -ge $retry ]; then return $rc; fi
 722         $verbose "      fshash mismatch; retrying"
 723         attempt=$(( $attempt + 1 ))
 724         ;;
 725       *)
 726         return $rc_diff
 727         ;;
 728     esac
 729   done
 730
 731   ## Glorious success.
 732   maybe rm -f $localmap
 733   $verbose "    fshash match"
 734
 735   ## Commit this backup.
 736   case $dryrun in
 737     nil)
 738       runhook precommit $host $fs $date
 739       mv new $date
 740       mv new.fshash $date.fshash
 741       insert_index $host $fs $date $VOLUME
 742       runhook commit $host $fs $date
 743       mkdir hack
 744       ln -s $date hack/last
 745       mv hack/last .
 746       rmdir hack
 747       ;;
 748   esac
 749   $verbose "    commit"
 750
 751   ## Expire old backups.
 752   case "${expire_policy+t},${default_policy+t}" in
 753     ,t) expire_policy=$default_policy ;;
 754   esac
 755   case "${expire_policy+t},$dryrun" in
 756     t,nil) run "expiry for $host:$fs" expire_backups ;;
 757     t,t) expire_backups ;;
 758   esac
 759   clear_policy=t
 760
 761   ## Report success.
 762   case $dryrun in
 763     t) log "END BACKUP of $host:$fs" ;;
 764     nil) log "SUCCESSFUL BACKUP of $host:$fs" ;;
 765   esac
 766 }
 767
 768 run_backup_cmd () {
 769   fs=$1 date=$2 cmd=$3; shift 3
 770   ## try_backup FS DATE COMMAND ARGS ...
 771   ##
 772   ## Run COMMAND ARGS to back up filesystem FS on the current host,
 773   ## maintaining a log, and checking whether it worked.  The caller has
 774   ## usually worked out the DATE in order to set up the filesystem, and we
 775   ## need it to name the log file properly.
 776
 777   ## Find a name for the log file.  In unusual circumstances, we may have
 778   ## deleted old logs from today, so just checking for an unused sequence
 779   ## number is insufficient.  Instead, check all of the logfiles for today,
 780   ## and use a sequence number that's larger than any of them.
 781   case $dryrun in
 782     t)
 783       log=/dev/null
 784       ;;
 785     nil)
 786       seq=1
 787       for i in "$logdir/$host/$fs.$date#"*; do
 788         tail=${i##*#}
 789         case "$tail" in [!1-9]* | *[!0-9]*) continue ;; esac
 790         if [ -f "$i" -a $tail -ge $seq ]; then seq=$(( tail + 1 )); fi
 791       done
 792       log="$logdir/$host/$fs.$date#$seq"
 793       ;;
 794   esac
 795
 796   ## Run the backup command.
 797   case $dryrun in nil) mkdir -p $logdir/$host ;; esac
 798   if ! "$cmd" "$@" 9>$log 1>&9; then
 799     echo >&2
 800     echo >&2 "$quis: backup of $host:$fs FAILED!"
 801     bkprc=1
 802   fi
 803
 804   ## Count up the logfiles.
 805   nlog=0
 806   for i in "$logdir/$host/$fs".*; do
 807     if [ ! -f "$i" ]; then continue; fi
 808     nlog=$(( nlog + 1 ))
 809   done
 810
 811   ## If there are too many, go through and delete some early ones.
 812   if [ $dryrun = nil ] && [ $nlog -gt $MAXLOG ]; then
 813     n=$(( nlog - MAXLOG ))
 814     for i in "$logdir/$host/$fs".*; do
 815       if [ ! -f "$i" ]; then continue; fi
 816       rm -f "$i"
 817       n=$(( n - 1 ))
 818       if [ $n -eq 0 ]; then break; fi
 819     done
 820   fi
 821 }
 822
 823 backup () {
 824   ## backup FS[:ARG] ...
 825   ##
 826   ## Back up the filesystems on the currently selected host using the
 827   ## currently selected snapshot type.
 828
 829   ## Make sure that there's a store volume.  We must do this here rather than
 830   ## in the main body of the script, since the configuration file needs a
 831   ## chance to override STOREDIR.
 832   if ! [ -r $STOREDIR/.rsync-backup-store ]; then
 833     echo >&2 "$quis: no backup volume mounted"
 834     exit 15
 835   fi
 836
 837   ## Read the volume name if we don't have one already.  Again, this allows
 838   ## the configuration file to provide a volume name.
 839   case "${VOLUME+t}${VOLUME-nil}" in
 840     nil) VOLUME=$(cat $METADIR/volume) ;;
 841   esac
 842
 843   ## Back up each requested file system in turn.
 844   for fs in "$@"; do
 845
 846     ## Parse the argument.
 847     case $fs in
 848       *:*) fsarg=${fs#*:} fs=${fs%%:*} ;;
 849       *) fsarg="" ;;
 850     esac
 851     $verbose "  filesystem $fs"
 852
 853     ## Move to the store directory and set up somewhere to put this backup.
 854     cd $STOREDIR
 855     case $dryrun in
 856       nil)
 857         if [ ! -d $host ]; then
 858           mkdir -m755 $host
 859           chown root:root $host
 860         fi
 861         if [ ! -d $host/$fs ]; then
 862           mkdir -m750 $host/$fs
 863           chown root:backup $host/$fs
 864         fi
 865         ;;
 866     esac
 867     cd $host/$fs
 868
 869     ## Find out if we've already copied this filesystem today.
 870     date=$(date +%Y-%m-%d)
 871     if [ $dryrun = nil ] && [ -d $date ]; then
 872       $verbose "        already dumped"
 873       continue
 874     fi
 875
 876     ## Do the backup of this filesystem.
 877     run_backup_cmd $fs $date do_backup $date $fs $fsarg
 878   done
 879 }
 880
 881 ###--------------------------------------------------------------------------
 882 ### Configuration functions.
 883
 884 defhook start
 885 defhook end
 886
 887 done_first_host_p=nil
 888
 889 host () {
 890   host=$1
 891   like= userat=
 892   case $done_first_host_p in
 893     nil) runhook start; done_first_host_p=t ;;
 894   esac
 895   case "${expire_policy+t},${default_policy+t}" in
 896     t,) default_policy=$expire_policy ;;
 897   esac
 898   unset expire_policy
 899   $verbose "host $host"
 900 }
 901
 902 snaptype () { snap=$1; shift; snapargs="$*"; retry=0; }
 903 rsyncargs () { rsyncargs="$*"; }
 904 like () { like="$*"; }
 905 retry () { retry="$*"; }
 906 user () { userat="$*@"; }
 907
 908 retain () {
 909   case $clear_policy in t) unset expire_policy; clear_policy=nil ;; esac
 910   expire_policy="${expire_policy+$expire_policy
 911 }$*"
 912 }
 913
 914 ###--------------------------------------------------------------------------
 915 ### Read the configuration and we're done.
 916
 917 usage () {
 918   echo "usage: $quis [-nv] [-c CONF]"
 919 }
 920
 921 version () {
 922   echo "$quis version $VERSION"
 923 }
 924
 925 config () {
 926   echo
 927   cat <<EOF
 928 conf = $conf
 929 mntbkpdir = $mntbkpdir
 930 fshashdir = $fshashdir
 931 logdir = $logdir
 932 EOF
 933 }
 934
 935 whine () { echo >&8 "$@"; }
 936
 937 while getopts "hVvc:n" opt; do
 938   case "$opt" in
 939     h) usage; exit 0 ;;
 940     V) version; config; exit 0 ;;
 941     v) verbose=whine ;;
 942     c) conf=$OPTARG ;;
 943     n) dryrun=t ;;
 944     *) exit 1 ;;
 945   esac
 946 done
 947 shift $((OPTIND - 1))
 948 case $# in 0) ;; *) usage >&2; exit 1 ;; esac
 949 exec 8>&1
 950
 951 . "$conf"
 952
 953 runhook end $bkprc
 954 case "$bkprc" in
 955   0) $verbose "All backups successful" ;;
 956   *) $verbose "Backups FAILED" ;;
 957 esac
 958
 959 ###----- That's all, folks --------------------------------------------------
 960
 961 exit $bkprc