Comments inline
On 2/25/20 11:28 AM, Dominic Jäger wrote:
Move wipe_disks from PVE::Ceph::Tools to PVE::Diskmanage and improve it by
- Handling invalid parameters
- Adding options for wiping
- Making names clearer, especially the sub name to indicate that it works for
partitions, too.
- Use `blockdev` system call because it is easier to understand
- Adding tests
Relies on the corresponding patch in pve-manager.
Signed-off-by: Dominic Jäger <d.jae...@proxmox.com>
---
v1->v2:
- Fix typo
- Not only move the function but also improve it
PVE/Diskmanage.pm | 63 ++++++++++++++++++++++++++++++++++++++
test/disklist_test.pm | 71 +++++++++++++++++++++++++++++++++++++++++++
2 files changed, 134 insertions(+)
diff --git a/PVE/Diskmanage.pm b/PVE/Diskmanage.pm
index abb90a7..09d89a0 100644
--- a/PVE/Diskmanage.pm
+++ b/PVE/Diskmanage.pm
@@ -761,4 +761,67 @@ sub append_partition {
return $partition;
}
+sub get_blockdev_size {
+ my ($dev) = @_;
+ my $size = `blockdev --getsize64 $dev`;
this is prone to command injection, if somehow someone manages to
call this with $dev set to e.g., 'foo; rm -rf /*'
i'd rather leave that a read from sysfs or use run_command
if you really want to use blockdev
+ chomp $size;
+ return $size
+}
+
+# Wipe the first part of a device
+#
+# Calls dd and optionally wipefs. This is useful to clear off leftovers from
+# previous use as it avoids failing OSD and directory creation.
+#
+# $devices array of blockdevices (including partitions), e.g. ['/dev/sda3']
+# $options hash with
+# - {amount} number of bytes that will be deleted. Will wipe at most the
+# device size. Default: 209715200.
+# - {wipefs} additionally erase all available signatures from all devices.
+# Default: false
+sub wipe_blockdevices {
+ my ($devices, $options) = @_;
+
+ my @dd_cmd = qw(/bin/dd if=/dev/zero iflag=count_bytes conv=fdatasync);
+
+ my $max_amount = $options->{amount};
+ if (!defined $max_amount) {
+ $max_amount = 209715200;
+ } elsif ($max_amount !~ /^\d+$/) {
+ die "Dying because $max_amount is not a natural number ".
+ "and thus not a valid value for max_amount.";
+ }
nitpick: probably better to write as:
$max_amount = $options->{amount} // 209...;
die "[..]" if $max_amount !~ m/^[0-9]+$/;
+
+ foreach my $dev (@$devices) {
+ eval { assert_blockdev($dev) };
+ if ($@) {
+ warn "Skipping $dev because it is not a blockdevice";
+ next;
+ }
does it really make sense to skip 'invalid' devices?
we want to give a list of things to wipe and just skip one
if it is not a blockdev?
would it not be better to assert all devs first, and error out
if any of them is not a valid blockdev before actually wiping anything?
+
+ my $device_size = get_blockdev_size($dev);
+ my $amount;
+ if (defined $device_size) {
nit: please use brackets: defined($foo)
+ $amount = ($device_size < $max_amount) ? $device_size : $max_amount;
+ } else {
+ warn "Could not get size of $dev. Wiping nonetheless but dd might throw
errors.";
+ $amount = $max_amount;
when can this happen? are there blockdevs (asserted above) that have no
size?
if yes, does it really makes sense to write something to it?
+ }
+
+ print "Wiping device: $dev\n";
+ if ($options->{wipefs}) {
+ # wipefs location:
+ # - Debian 9: /sbin/wipefs
+ # - Debian 10: /usr/sbin/wipefs
+ # The symlink from /sbin to /usr/sbin makes this work for fresh PVE
the comment is odd:
pve6 here:
# which wipefs
/sbin/wipefs
# dpkg -S /sbin/wipefs
util-linux
# dpkg -L util-linux
/sbin/wipefs
/usr/share/bash[...]
/usr/share/man[...]
+ # 6 as well as upgraded ones
+ eval { run_command(['/sbin/wipefs', '-a', $dev]) };
+ warn $@ if $@;
+ }
+ # 1M seems reasonable for this case
+ eval { run_command([@dd_cmd, "count=$amount", "bs=1M", "of=${dev}"]) };
+ warn $@ if $@;
+ }
+}
+
1;
diff --git a/test/disklist_test.pm b/test/disklist_test.pm
index 9cb6763..280ea41 100644
--- a/test/disklist_test.pm
+++ b/test/disklist_test.pm
@@ -10,6 +10,7 @@ use PVE::Tools;
use Test::MockModule;
use Test::More;
+use Capture::Tiny;
use JSON;
use Data::Dumper;
@@ -248,4 +249,74 @@ while (readdir $dh) {
test_disk_list($dir);
}
+
+subtest 'wipe_blockdevices' => sub {
+
+ plan tests => 9;
+ sub wipe_helper {
+ my ($options, $devices) = @_;
+ $devices //= ['/dev/sdb'];
+ return Capture::Tiny::capture {
+ PVE::Diskmanage::wipe_blockdevices($devices, $options);
+ };
+ }
+
+ $diskmanage_module->mock('run_command' => sub { });
+ my $device_size = 0;
+ $diskmanage_module->mock('get_blockdev_size' => sub { return $device_size
});
+ {
+ eval { PVE::Diskmanage::wipe_blockdevices(['/dev/sdb'], {amount=>-3})};
+ like ($@, qr/-3 is not/, 'Die with negative amounts');
+ }
+ {
+ $diskmanage_module->mock('assert_blockdev' => sub { die });
+ my (undef, $stderr, undef) = wipe_helper();
+ like ($stderr, qr!Skipping /dev/sdb!, 'Skip invalid devices');
+ $diskmanage_module->mock('assert_blockdev' => sub { });
+ }
+ {
+ my ($stdout, undef, undef) = wipe_helper();
+ like ($stdout, qr!Wiping device: /dev/sdb\n!, 'Invoking with a disk');
+ }
+ {
+ my ($stdout, undef, undef) = wipe_helper(undef, ['/dev/sdb1']);
+ like ($stdout, qr!Wiping device: /dev/sdb1\n!, 'Invoking with a
partition');
+ }
+
+ $diskmanage_module->mock('run_command' => sub { print Dumper(@_) });
+ my $default_max_wipe_amount = 209715200;
+ {
+ $device_size = $default_max_wipe_amount-1;
+ my ($stdout, undef, undef) = wipe_helper();
+ like ($stdout, qr!count=$device_size!,
+ 'Device size is smaller than default maximum wipe amount');
+ }
+ {
+ $device_size = $default_max_wipe_amount+1;
+ my ($stdout, undef, undef) = wipe_helper();
+ like ($stdout, qr!count=$default_max_wipe_amount!,
+ 'Device size is bigger than default maximum wipe amount');
+ }
+
+ my $changed_max_wipe_amount = 50000;
+ {
+ $device_size = $changed_max_wipe_amount-1;
+ my ($stdout, undef, undef) =
wipe_helper({amount=>$changed_max_wipe_amount});
+ like ($stdout, qr!count=$device_size!,
+ 'Device size is smaller than changed maximum wipe amount');
+ }
+ {
+ $device_size = $changed_max_wipe_amount+1;
+ my ($stdout, undef, undef) =
wipe_helper({amount=>$changed_max_wipe_amount});
+ like ($stdout, qr!count=$changed_max_wipe_amount!,
+ 'Device size is bigger than changed maximum wipe amount');
+ }
+ {
+ $device_size = 0;
+ my ($stdout, $stderr, undef) = wipe_helper({wipefs=>1});
+ like ($stdout, qr!/wipefs!, 'Call wipefs');
+ }
+ $testcount++;
+};
+
done_testing($testcount);
good that you included tests :)
maybe it is my paranoia, but i would prefer to use a path that
is not a real blockdev e.g., /tmp/pve/fakeblock
just in case that run command is not actually mocked?
also i guess those tests only work if there is actually a /dev/sdb since
i do not see an 'assert_blockdev' mock at the beginning so the first
test would fail?
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