#!/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
use strict;
use Sys::Guestfs;
-use Sys::Guestfs::Lib qw(open_guest get_partitions);
+use Sys::Guestfs::Lib qw(feature_available);
use Pod::Usage;
use Getopt::Long;
-use Data::Dumper;
-use XML::Writer;
+use File::Basename qw(basename);
use POSIX qw(ceil);
use Locale::TextDomain 'libguestfs';
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
+
=back
=cut
"csv" => \$csv,
"human-readable|human|h" => \$human,
"inodes|i" => \$inodes,
+ "one-per-guest" => \$one_per_guest,
) 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;
-# Open the guest handle.
+# 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
+# create the libguestfs handle/appliance as few times as possible.
+#
+# If virt-df is called with no parameters, then run the libvirt
+# equivalent of "virsh list --all", get the XML for each domain, and
+# get the disk devices.
+#
+# If virt-df is called with parameters, assume it must either be a
+# single disk image filename, a list of disk image filenames, or a
+# single libvirt guest name. Construct disk devices accordingly.
+
+my @domains = ();
-if (@ARGV == 0) {
+if (@ARGV == 0) { # No params, use libvirt.
my $conn;
if ($uri) {
# https://bugzilla.redhat.com/show_bug.cgi?id=538041
@doms = grep { $_->get_id () != 0 } @doms;
- my @domnames = sort (map { $_->get_name () } @doms);
+ exit 0 unless @doms;
+
+ foreach my $dom (@doms) {
+ my @disks = get_disks_from_libvirt ($dom);
+ push @domains, { dom => $dom,
+ name => $dom->get_name (),
+ 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] ] }
+ } else {
+ my $conn;
- if (@domnames) {
- print_title ();
- foreach (@domnames) {
- eval { do_df ($_); };
- warn $@ if $@;
+ if ($uri) {
+ $conn = Sys::Virt->new (readonly => 1, address => $uri);
+ } else {
+ $conn = Sys::Virt->new (readonly => 1);
}
+
+ my $dom = $conn->get_domain_by_name ($ARGV[0])
+ or die __x("{name} is not the name of a libvirt domain\n",
+ name => $ARGV[0]);
+ my @disks = get_disks_from_libvirt ($dom);
+ push @domains, { dom => $dom,
+ name => $dom->get_name (),
+ disks => \@disks }
}
-} else {
- print_title ();
- do_df (@ARGV);
+} else { # >= 2 params, all disk images.
+ push @domains, { name => basename ($ARGV[0]),
+ disks => \@ARGV }
}
-sub do_df
+sub get_disks_from_libvirt
{
- my $g;
+ my $dom = shift;
+ my $xml = $dom->get_xml_description ();
- if ($uri) {
- $g = open_guest (\@_, address => $uri);
- } else {
- $g = open_guest (\@_);
+ my $p = XML::XPath->new (xml => $xml);
+ my @disks = $p->findnodes ('//devices/disk/source/@dev');
+ push (@disks, $p->findnodes ('//devices/disk/source/@file'));
+
+ # Code in Sys::Guestfs::Lib dies here if there are no disks at all.
+
+ return map { $_->getData } @disks;
+}
+
+# Sort the domains by name for display.
+@domains = sort { $a->{name} cmp $b->{name} } @domains;
+
+# Since we got this far, we're somewhat sure we're going to
+# get to print the result, so display the title.
+print_title ();
+
+# To minimize the number of times we have to launch the appliance,
+# shuffle as many domains together as we can, but not exceeding
+# MAX_DISKS per request. If --one-per-guest was requested then only
+# request disks from a single guest each time.
+if ($one_per_guest) {
+ foreach (@domains) {
+ my @request = ( $_ );
+ multi_df (@request);
+ }
+} else {
+ while (@domains) {
+ my $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);
}
+}
+
+sub multi_df
+{
+ local $_;
+ eval {
+ my $g = Sys::Guestfs->new ();
- $g->launch ();
-
- my @partitions = get_partitions ($g);
-
- # Think of a printable name for this domain. Just choose the
- # first parameter passed to this function, which will work for
- # most cases (it'll either be the domain name or the first disk
- # image name).
- my $domname = $_[0];
-
- # Mount each partition in turn, and if mountable, do a statvfs on it.
- foreach my $partition (@partitions) {
- my %stat;
- eval {
- $g->mount_ro ($partition, "/");
- %stat = $g->statvfs ("/");
- };
- if (!$@) {
- print_stat ($domname, $partition, \%stat);
+ my ($d, $disk);
+
+ foreach $d (@_) {
+ foreach $disk (@{$d->{disks}}) {
+ $g->add_drive_ro ($disk);
+ }
+ }
+
+ $g->launch ();
+ my $has_lvm2 = feature_available ($g, "lvm2");
+
+ my @devices = $g->list_devices ();
+ my @partitions = $g->list_partitions ();
+
+ my $n = 0;
+ foreach $d (@_) {
+ my $name = $d->{name};
+ 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 $has_lvm2;
+
+ # Find which whole devices (RHBZ#590167), partitions and LVs
+ # contain mountable filesystems. Stat those which are
+ # mountable, and ignore the others.
+ foreach (@devs) {
+ try_df ($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, $_);
+ }
+ }
+
+ $n += $nr_disks;
+ }
+ };
+ warn if $@;
+}
+
+sub filter_partitions
+{
+ my $devs = shift;
+ my @devs = @$devs;
+ my @r;
+
+ foreach my $p (@_) {
+ foreach my $d (@devs) {
+ if ($p =~ /^$d\d/) {
+ push @r, $p;
+ last;
+ }
}
- $g->umount_all ();
}
+
+ return @r;
+}
+
+# Calculate the canonical name for a device.
+# eg: /dev/vdb1 when offset = 1
+# => canonical name is /dev/sda1
+sub canonical_dev
+{
+ local $_;
+ my $dev = shift;
+ my $offset = shift;
+
+ return $dev unless $dev =~ m{^/dev/.d([a-z])(\d*)$};
+ my $disk = $1;
+ my $partnum = $2;
+
+ $disk = chr (ord ($disk) - $offset);
+
+ return "/dev/sd$disk$partnum"
+}
+
+sub try_df
+{
+ local $_;
+ my $domname = shift;
+ my $g = shift;
+ my $dev = shift;
+ my $display = shift || $dev;
+
+ my %stat;
+ eval {
+ $g->mount_ro ($dev, "/");
+ %stat = $g->statvfs ("/");
+ };
+ if (!$@) {
+ print_stat ($domname, $display, \%stat);
+ }
+ $g->umount_all ();
}
sub print_stat
{
my $domname = shift;
- my $partition = shift;
+ my $dev = shift;
my $stat = shift;
- my @cols = ($domname, $partition);
+ my @cols = ($domname, $dev);
if (!$inodes) {
my $bsize = $stat->{bsize}; # block size
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