#!/usr/bin/perl -w
# virt-df
-# Copyright (C) 2009 Red Hat Inc.
+# Copyright (C) 2009-2010 Red Hat Inc.
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
=cut
+my $format;
+
+=item B<--format> raw
+
+Specify the format of disk images given on the command line. If this
+is omitted then the format is autodetected from the content of the
+disk image.
+
+If disk images are requested from libvirt, then this program asks
+libvirt for this information. In this case, the value of the format
+parameter is ignored.
+
+If working with untrusted raw-format guest disk images, you should
+ensure the format is always specified.
+
+=cut
+
my $human;
=item B<--human-readable> | B<-h>
Print inodes instead of blocks.
+=cut
+
+my $one_per_guest;
+
+=item B<--one-per-guest>
+
+Run one libguestfs appliance per guest. Normally C<virt-df> will
+add the disks from several guests to a single libguestfs appliance.
+
+You might use this option in the following circumstances:
+
+=over 4
+
+=item *
+
+If you think an untrusted guest might actively try to exploit the
+libguestfs appliance kernel, then this prevents one guest from
+interfering with the stats printed for another guest.
+
+=item *
+
+If the kernel has a bug which stops it from accessing a
+filesystem in one guest (see for example RHBZ#635373) then
+this allows libguestfs to continue and report stats for further
+guests.
+
+=back
+
+=cut
+
+my $uuid;
+
+=item B<--uuid>
+
+Print UUIDs instead of names. This is useful for following
+a guest even when the guest is migrated or renamed, or when
+two guests happen to have the same name.
+
+Note that only domains that we fetch from libvirt come with UUIDs.
+For disk images, we still print the disk image name even when
+this option is specified.
+
=back
=cut
"version" => \$version,
"connect|c=s" => \$uri,
"csv" => \$csv,
+ "format=s" => \$format,
"human-readable|human|h" => \$human,
"inodes|i" => \$inodes,
+ "one-per-guest" => \$one_per_guest,
+ "uuid" => \$uuid,
) or pod2usage (2);
pod2usage (1) if $help;
if ($version) {
# RHBZ#600977
die __"virt-df: cannot use -h and --csv options together\n" if $human && $csv;
+# RHBZ#635373
+#
+# Limit the number of devices we will ever add to the appliance. The
+# overall limit in current libguestfs is 25: 26 = number of letters in
+# the English alphabet since we are only confident that /dev/sd[a-z]
+# will work because of various limits, minus 1 because that may be
+# used by the ext2 initial filesystem.
+my $max_disks = 25;
+
# Get the list of domains and block devices.
#
# We can't use Sys::Guestfs::Lib::open_guest here because we want to
my @disks = get_disks_from_libvirt ($dom);
push @domains, { dom => $dom,
name => $dom->get_name (),
+ uuid => $dom->get_uuid_string (),
disks => \@disks }
}
} elsif (@ARGV == 1) { # One param, could be disk image or domname.
if (-e $ARGV[0]) {
push @domains, { name => basename ($ARGV[0]),
- disks => [ $ARGV[0] ] }
+ disks => [ [ $ARGV[0], $format ] ] }
} else {
my $conn;
my @disks = get_disks_from_libvirt ($dom);
push @domains, { dom => $dom,
name => $dom->get_name (),
+ uuid => $dom->get_uuid_string (),
disks => \@disks }
}
} else { # >= 2 params, all disk images.
+ my @disks = map { [ $_, $format ] } @ARGV;
push @domains, { name => basename ($ARGV[0]),
- disks => \@ARGV }
+ disks => \@disks }
}
sub get_disks_from_libvirt
my $xml = $dom->get_xml_description ();
my $p = XML::XPath->new (xml => $xml);
- my @disks = $p->findnodes ('//devices/disk/source/@dev');
- push (@disks, $p->findnodes ('//devices/disk/source/@file'));
+ my $nodes = $p->find ('//devices/disk');
+
+ my @disks;
+ my $node;
+ foreach $node ($nodes->get_nodelist) {
+ # The filename can be in dev or file attribute, hence:
+ my $filename = $p->find ('./source/@dev', $node);
+ unless ($filename) {
+ $filename = $p->find ('./source/@file', $node);
+ next unless $filename;
+ }
+ $filename = $filename->to_literal;
+
+ # Get the disk format (may not be set).
+ my $format = $p->find ('./driver/@type', $node);
+ $format = $format->to_literal if $format;
+
+ push @disks, [ $filename, $format ];
+ }
# Code in Sys::Guestfs::Lib dies here if there are no disks at all.
- return map { $_->getData } @disks;
+ return @disks;
}
# Sort the domains by name for display.
print_title ();
# To minimize the number of times we have to launch the appliance,
-# shuffle as many domains together as we can, but not exceeding 26
-# disks per request. (26 = # of letters in the English alphabet, and
-# we are only confident that /dev/sd[a-z] will work because of various
-# limits).
-my $n = 0;
-my @request = ();
-while (@domains) {
+# shuffle as many domains together as we can, but not exceeding
+# MAX_DISKS per request. If --one-per-guest was requested then only
+# request disks from a single guest each time.
+if ($one_per_guest) {
+ foreach (@domains) {
+ my @request = ( $_ );
+ multi_df (@request);
+ }
+} else {
while (@domains) {
- my $c = @{$domains[0]->{disks}};
- last if $n + $c > 26;
- push @request, shift @domains;
+ my $n = 0; # number of disks added so far
+ my @request = ();
+ while (@domains) {
+ my $c = @{$domains[0]->{disks}};
+ if ($c > $max_disks) {
+ warn __x("virt-df: ignoring {name}, it has too many disks ({c} > {max})",
+ name => $domains[0]->{name},
+ c => $c, max => $max_disks);
+ next;
+ }
+ last if $n + $c > $max_disks;
+ $n += $c;
+ push @request, shift (@domains);
+ }
+ multi_df (@request);
}
- multi_df (@request);
}
sub multi_df
{
local $_;
- my $g = Sys::Guestfs->new ();
-
- my ($d, $disk);
-
- foreach $d (@_) {
- foreach $disk (@{$d->{disks}}) {
- $g->add_drive_ro ($disk);
+ eval {
+ my $g = Sys::Guestfs->new ();
+
+ my ($d, $disk);
+
+ foreach $d (@_) {
+ foreach $disk (@{$d->{disks}}) {
+ my $filename = $disk->[0];
+ my $format = $disk->[1];
+ my @args = ($filename);
+ push @args, readonly => 1;
+ push @args, format => $format if defined $format;
+ $g->add_drive_opts (@args);
+ }
}
- }
- $g->launch ();
- my $has_lvm2 = feature_available ($g, "lvm2");
+ $g->launch ();
+ my $has_lvm2 = feature_available ($g, "lvm2");
- my @devices = $g->list_devices ();
- my @partitions = $g->list_partitions ();
+ my @devices = $g->list_devices ();
+ my @partitions = $g->list_partitions ();
- my $n = 0;
- foreach $d (@_) {
- my $name = $d->{name};
- my $nr_disks = @{$d->{disks}};
+ my $n = 0;
+ foreach $d (@_) {
+ my $name = $d->{name};
+ my $uuid = $d->{uuid};
+ my $nr_disks = @{$d->{disks}};
- # Filter LVM to only the devices applying to the original domain.
- my @devs = @devices[$n .. $n+$nr_disks-1];
- $g->lvm_set_filter (\@devs) if $has_lvm2;
+ # Filter LVM to only the devices applying to the original domain.
+ my @devs = @devices[$n .. $n+$nr_disks-1];
+ $g->lvm_set_filter (\@devs) if $has_lvm2;
- # Find which whole devices (RHBZ#590167), partitions and LVs
- # contain mountable filesystems. Stat those which are
- # mountable, and ignore the others.
- foreach (@devs) {
- try_df ($name, $g, $_, canonical_dev ($_, $n));
- }
- foreach (filter_partitions (\@devs, @partitions)) {
- try_df ($name, $g, $_, canonical_dev ($_, $n));
- }
- if ($has_lvm2) {
- foreach ($g->lvs ()) {
- try_df ($name, $g, $_);
+ # Find which whole devices (RHBZ#590167), partitions and LVs
+ # contain mountable filesystems. Stat those which are
+ # mountable, and ignore the others.
+ foreach (@devs) {
+ try_df ($name, $uuid, $g, $_, canonical_dev ($_, $n));
+ }
+ foreach (filter_partitions (\@devs, @partitions)) {
+ try_df ($name, $uuid, $g, $_, canonical_dev ($_, $n));
+ }
+ if ($has_lvm2) {
+ foreach ($g->lvs ()) {
+ try_df ($name, $uuid, $g, $_);
+ }
}
- }
- $n += $nr_disks;
- }
+ $n += $nr_disks;
+ }
+ };
+ warn if $@;
}
sub filter_partitions
{
local $_;
my $domname = shift;
+ my $domuuid = shift;
my $g = shift;
my $dev = shift;
my $display = shift || $dev;
%stat = $g->statvfs ("/");
};
if (!$@) {
- print_stat ($domname, $display, \%stat);
+ print_stat ($domname, $domuuid, $display, \%stat);
}
$g->umount_all ();
}
sub print_stat
{
my $domname = shift;
+ my $domuuid = shift;
my $dev = shift;
my $stat = shift;
- my @cols = ($domname, $dev);
+ my @cols;
+ if (!$uuid || !defined $domuuid) {
+ push @cols, $domname;
+ } else {
+ push @cols, $domuuid;
+ }
+ push @cols, $dev;
if (!$inodes) {
my $bsize = $stat->{bsize}; # block size
printf "%-36s%10s %10s %10s %5s\n",
$cols[1], $cols[2], $cols[3], $cols[4], $cols[5];
} else {
+ # Columns don't need special CSV quoting.
print (join (",", @cols), "\n");
}
}
printf ("%10s %10s %10s %5s\n", $_[2], $_[3], $_[4], $percent);
} else {
- printf ("\"%s\",\"%s\",%d,%d,%d,%.1f%%\n", @_);
+ # Need to quote libvirt domain and filesystem.
+ my $dom = shift;
+ my $fs = shift;
+ print csv_quote($dom), ",", csv_quote($fs), ",";
+ printf ("%d,%d,%d,%.1f%%\n", @_);
}
}
}
}
+# Quote field for CSV without using an external module.
+sub csv_quote
+{
+ local $_ = shift;
+
+ my $needs_quoting = /[ ",\n\0]/;
+ return $_ unless $needs_quoting;
+
+ my $i;
+ my $out = '"';
+ for ($i = 0; $i < length; ++$i) {
+ my $c = substr $_, $i, 1;
+ if ($c eq '"') {
+ $out .= '""';
+ } elsif ($c eq '\0') {
+ $out .= '"0';
+ } else {
+ $out .= $c;
+ }
+ }
+ $out .= '"';
+
+ return $out;
+}
+
=head1 NOTE ABOUT CSV FORMAT
Comma-separated values (CSV) is a deceptive format. It I<seems> like
Most spreadsheets and databases can import CSV directly.
+=head1 SHELL QUOTING
+
+Libvirt guest names can contain arbitrary characters, some of which
+have meaning to the shell such as C<#> and space. You may need to
+quote or escape these characters on the command line. See the shell
+manual page L<sh(1)> for details.
+
=head1 SEE ALSO
L<guestfs(3)>,
git.annexia.org / libguestfs.git / blobdiff