use strict;
use IO::File;
use Getopt::Std;
-
-#
-# Copyright (c) 2003 Silicon Graphics, Inc. All Rights Reserved.
-#
-# This program is free software; you can redistribute it and/or modify it
-# under the terms of version 2 of the GNU General Public License as
-# published by the Free Software Foundation.
-#
-# This program is distributed in the hope that it would be useful, but
-# WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
-#
-# Further, this software is distributed without any warranty that it is
-# free of the rightful claim of any third person regarding infringement
-# or the like. Any license provided herein, whether implied or
-# otherwise, applies only to this software file. Patent licenses, if
-# any, provided herein do not apply to combinations of this program with
-# other software, or any other product whatsoever.
-#
-# You should have received a copy of the GNU General Public License along
-# with this program; if not, write the Free Software Foundation, Inc., 59
-# Temple Place - Suite 330, Boston MA 02111-1307, USA.
-#
-# Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
-# Mountain View, CA 94043, or:
-#
-# http://www.sgi.com
-#
-# For further information regarding this notice, see:
-#
-# http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
#
-
+# Copyright (c) 2003-2004 Silicon Graphics, Inc. All Rights Reserved.
#
# Modify a filesystem's superblock and AGF metadata structures
# so that only a subset of the allocation groups will be used.
# the block addresses are large).
#
-my @sbprint = ( '"print fdblocks"', '"print agcount"' );
-my @agfprint = ( '"print freeblks"', '"print flcount"' );
-my @agfcommands = ( '"write freeblks 0"',
- '"write longest 0"', '"write flcount 0"',
- '"write bnolevel 1"', '"write cntlevel 1"',
- '"write flfirst 0"', '"write fllast 0"' );
-my @bnoprint = ( '"addr bnoroot"', '"print numrecs"' );
-my @bnocommands = ( '"addr bnoroot"', '"write numrecs 0"',
- '"write leftsib -1"', '"write rightsib -1"' );
-my @cntprint = ( '"addr cntroot"', '"print numrecs"' );
-my @cntcommands = ( '"addr cntroot"', '"write numrecs 0"',
- '"write leftsib -1"', '"write rightsib -1"' );
-
my %opt;
-getopts('cf:l:v', \%opt);
-die "Usage: ag-wipe [-f firstAG] [-l lastAG] [-cv] device\n" unless (@ARGV == 1);
+getopts('cf:l:qr:v', \%opt);
+
+die "Usage: $0 [-f AG] [-l AG] [-r bytes] [-cqv] device\n" unless (@ARGV == 1);
my $device = shift @ARGV;
die "$device: no such file\n" unless (-e $device);
+
my $clearall = defined($opt{'c'}) ? 1 : 0;
+my $retain = defined($opt{'r'}) ? $opt{'r'} : -1;
+my $quiet = defined($opt{'q'}) ? 1 : 0;
my $verbose = defined($opt{'v'}) ? 1 : 0;
my $nagfirst = defined($opt{'f'}) ? $opt{'f'} : 0;
my $naglast = defined($opt{'l'}) ? $opt{'l'} : 0;
+#
+# "clearall" means clear everything barring the final AG.
+# "retain" means clearall and retain a specified amount in the
+# second-from-last AG as well (value is the number of bytes).
+# [NB: retain with a value of zero is now the same as clearall].
+#
+if ($retain >= 0) {
+ $clearall = 1;
+}
+
sub xfs_db {
- my $xfsdb = "xfs_db -x $device";
+ my $xfsdb = 'xfs_db -x';
my %hash;
foreach (@_) {
$xfsdb .= ' -c ' . $_;
}
- print $xfsdb, "\n" if ($verbose);
+ print $xfsdb, ' ', $device, "\n" if ($verbose);
- die unless open(DB, "$xfsdb 2>/dev/null |");
+ die unless open(DB, "$xfsdb $device 2>/dev/null |");
while (<DB>) {
if (/^(\S+) = (.*)$/) {
print if ($verbose);
return %hash;
}
+
+#
+# Stage 1: Get control information from the superblock
+#
+
+my @sbprint = ( '"print fdblocks"', '"print agcount"', '"print blocksize"' );
+my @agffree = ( '"print freeblks"' );
+
my %sb = xfs_db 'sb', @sbprint;
print "=== Initially ", $sb{'fdblocks'}, " blocks free across ",
- $sb{'agcount'}, " AGs\n";
+ $sb{'agcount'}, " AGs\n" unless $quiet;
if ($clearall && ($nagfirst || $naglast)) {
- print STDERR " o Clearall specified with first/last AG, quiting\n";
+ print STDERR " o Clearall/retain specified with first/last AG\n";
exit(1);
}
if ($nagfirst >= $sb{'agcount'}) {
- print " o First AG number is too large, quiting\n";
+ print STDERR " o First AG number is too large\n";
exit(1);
}
if ($naglast >= $sb{'agcount'}) {
- print " o Last AG number is too large, quiting\n";
+ print STDERR " o Last AG number is too large\n";
exit(1);
}
if ($naglast - $nagfirst < 0) {
- print " o No AGs to clear, quiting\n";
+ print STDERR " o No AGs to clear\n";
exit(1);
}
if ($clearall) {
$naglast = $sb{'agcount'} - 2;
+ if ($retain > 0) {
+ my %check;
+
+ $naglast--;
+ $retain /= $sb{'blocksize'}; # convert to fsblocks
+ %check = xfs_db "'agf $naglast'", @agffree;
+ if ($check{'freeblks'} < $retain) {
+ print STDERR " o Insufficient space to retain\n";
+ exit(1);
+ }
+ }
}
+
+#
+# Stage 2: Wipe out all completely masked allocation groups.
+#
+
+my @agfprint = ( '"print freeblks"', '"print flcount"' );
+my @agfcommands = ( '"write freeblks 0"',
+ '"write longest 0"', '"write flcount 0"',
+ '"write bnolevel 1"', '"write cntlevel 1"',
+ '"write flfirst 0"', '"write fllast 0"' );
+my @bnoprint = ( '"addr bnoroot"', '"print numrecs"' );
+my @bnocommands = ( '"addr bnoroot"', '"write numrecs 0"',
+ '"write leftsib -1"', '"write rightsib -1"' );
+my @cntprint = ( '"addr cntroot"', '"print numrecs"' );
+my @cntcommands = ( '"addr cntroot"', '"write numrecs 0"',
+ '"write leftsib -1"', '"write rightsib -1"' );
+
print "=== Wiping ", $naglast - $nagfirst + 1,
- " AGs starting from AG #", $nagfirst, "\n";
+ " AGs starting from AG #", $nagfirst, "\n" unless $quiet;
my $ag = $nagfirst;
while ($ag <= $naglast) {
- my %btree;
- my %agf;
-
- print " o AG#", $ag, " AGF fields\n";
+ print " o AG#", $ag, " AGF fields\n" unless $quiet;
- %agf = xfs_db "'agf $ag'", @agfprint;
+ my %agf = xfs_db "'agf $ag'", @agfprint;
xfs_db "'agf $ag'", @agfcommands;
my $blockcnt = $agf{'freeblks'} + $agf{'flcount'};
$sb{'fdblocks'} -= $blockcnt;
- print " cleared ", $blockcnt, " blocks from AG#", $ag, "\n";
+ print " cleared ", $blockcnt, " blocks from AG#", $ag, "\n"
+ unless $quiet;
- %btree = xfs_db "'agf $ag'", @bnoprint;
- xfs_db "'agf $ag'", @bnocommands;
- print " cleared ", $btree{'numrecs'}, " BNO btree records in AG#",
- $ag, "\n";
+ my %btree = xfs_db "'agf $ag'", @bnoprint;
+ xfs_db "'agf $ag'", @bnocommands, "'agf $ag'", @cntcommands;
+ print " cleared ", $btree{'numrecs'}, " BNO/CNT btree recs in AG#",
+ $ag, "\n" unless $quiet;
- %btree = xfs_db "'agf $ag'", @cntprint;
- xfs_db "'agf $ag'", @cntcommands;
- print " cleared ", $btree{'numrecs'}, " CNT btree in AG#",
- $ag, "\n";
$ag++;
}
-print "=== Updating final freespace count, ", $sb{'fdblocks'}, " blocks\n";
+
+#
+# Stage 3: Wipe out any partially masked allocation group.
+#
+
+if ($retain > 0) {
+ print " o AG#", $ag, " AGF fields (partial)\n" unless $quiet;
+
+ my %ragf = xfs_db "'agf $ag'", '"print freeblks"',
+ '"addr bnoroot"', '"print recs[1].startblock"';
+ my $maskblks = $ragf{'freeblks'} - $retain;
+ my $newstart = $ragf{'recs[1].startblock'} + $maskblks;
+ xfs_db "'agf $ag'",
+ "'write freeblks $retain'", "'write longest $retain'",
+ "'agf $ag'", '"addr bnoroot"',
+ "'write recs[1].startblock $newstart'",
+ "'write recs[1].blockcount $retain'",
+ "'agf $ag'", '"addr cntroot"',
+ "'write recs[1].startblock $newstart'",
+ "'write recs[1].blockcount $retain'";
+
+ $sb{'fdblocks'} -= $maskblks;
+ print " cleared ", $maskblks, " blocks from AG#", $ag, "\n"
+ unless $quiet;
+}
+
+print "=== Updating final freespace count, ", $sb{'fdblocks'}, " blocks\n"
+ unless $quiet;
xfs_db "'sb 0'", "'write fdblocks $sb{'fdblocks'}'"