X-Git-Url: http://git.annexia.org/?p=libguestfs.git;a=blobdiff_plain;f=tools%2Fvirt-df;h=61fcfb8e76000dd600c412e65cdf3f023e9092a5;hp=b997691c7f8eb8fdf433764820e27746c5076d55;hb=61da709722ec244da1c3c7d4f1a8706f76687cb3;hpb=5477d98548661394cf0df3ce48929961e0d2a38f diff --git a/tools/virt-df b/tools/virt-df index b997691..61fcfb8 100755 --- a/tools/virt-df +++ b/tools/virt-df @@ -1,6 +1,6 @@ #!/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 @@ -20,12 +20,11 @@ use warnings; 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'; @@ -113,12 +112,31 @@ read L below. =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 sizes in human-readable format. +You are not allowed to use I<-h> and I<--csv> at the same time. + =cut my $inodes; @@ -127,6 +145,34 @@ my $inodes; Print inodes instead of blocks. +=cut + +my $one_per_guest; + +=item B<--one-per-guest> + +Run one libguestfs appliance per guest. Normally C 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 @@ -135,8 +181,10 @@ GetOptions ("help|?" => \$help, "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, ) or pod2usage (2); pod2usage (1) if $help; if ($version) { @@ -146,9 +194,34 @@ if ($version) { exit } -# Open the guest handle. +# 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 +# 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) { @@ -163,61 +236,225 @@ if (@ARGV == 0) { # https://bugzilla.redhat.com/show_bug.cgi?id=538041 @doms = grep { $_->get_id () != 0 } @doms; - my @domnames = map { $_->get_name () } @doms; + exit 0 unless @doms; - if (@domnames) { - print_title (); - foreach (@domnames) { - eval { do_df ($_); }; - warn $@ if $@; + 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], $format ] ] } + } else { + my $conn; + + if ($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. + my @disks = map { [ $_, $format ] } @ARGV; + push @domains, { name => basename ($ARGV[0]), + disks => \@disks } } -sub do_df +sub get_disks_from_libvirt { - my $g; + my $dom = shift; + my $xml = $dom->get_xml_description (); + + my $p = XML::XPath->new (xml => $xml); + 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 = $filename->to_literal; - if ($uri) { - $g = open_guest (\@_, address => $uri); - } else { - $g = open_guest (\@_); + # 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 ]; } - $g->launch (); - - my @partitions = get_partitions ($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); + # Code in Sys::Guestfs::Lib dies here if there are no disks at all. + + return @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 $g = Sys::Guestfs->new (); + + my ($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->umount_all (); + + $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; + } + } + } + + 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 @@ -277,6 +514,7 @@ sub print_title 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"); } } @@ -295,7 +533,11 @@ sub print_cols 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", @_); } } @@ -313,6 +555,31 @@ sub human_size } } +# 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 like @@ -337,6 +604,13 @@ for Perl or Python's built-in csv library). 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 for details. + =head1 SEE ALSO L,