[pve-devel] [PATCH v2 qemu-server 2/4] add NBD server unix socket support in vm_start

[Fabian Grünbichler]

On March 18, 2020 10:02 am, Stefan Reiter wrote:
> On 17/03/2020 20:56, Mira Limbeck wrote:
>> As the NBD server spawned by qemu can only listen on a single socket,
>> we're dependent on a version being passed to vm_start that indicates
>> which protocol can be used, TCP or Unix, by the source node.
>> 
>> The change in socket type (TCP to Unix) comes with a different URI. For
>> unix sockets it has the form: 'nbd:unix:<path/to/socket>:exportname=<device>'.
>> 
>> Signed-off-by: Mira Limbeck <m.limbeck at proxmox.com>
>> ---
>> v2:
>>   - added fallback to 0 if nbd_protocol_version is undefined
>>   - some cleanup regarding variables only used in one case
>> 
>>   PVE/QemuServer.pm | 34 ++++++++++++++++++++++++----------
>>   1 file changed, 24 insertions(+), 10 deletions(-)
>> 
>> diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
>> index 429ec05..2ef8bff 100644
>> --- a/PVE/QemuServer.pm
>> +++ b/PVE/QemuServer.pm
>> @@ -4707,7 +4707,8 @@ sub vmconfig_update_disk {
>>   
>>   sub vm_start {
>>       my ($storecfg, $vmid, $statefile, $skiplock, $migratedfrom, $paused,
>> -	$forcemachine, $spice_ticket, $migration_network, $migration_type, $targetstorage, $timeout) = @_;
>> +	$forcemachine, $spice_ticket, $migration_network, $migration_type,
>> +	$targetstorage, $timeout, $nbd_protocol_version) = @_;
>>   
>>       PVE::QemuConfig->lock_config($vmid, sub {
>>   	my $conf = PVE::QemuConfig->load_config($vmid, $migratedfrom);
>> @@ -4985,20 +4986,33 @@ sub vm_start {
>>   
>>   	#start nbd server for storage migration
>>   	if ($targetstorage) {
>> -	    my $nodename = nodename();
>> -	    my $localip = $get_migration_ip->($migration_network, $nodename);
>> -	    my $pfamily = PVE::Tools::get_host_address_family($nodename);
>> -	    my $storage_migrate_port = PVE::Tools::next_migrate_port($pfamily);
>> -
>> -	    mon_cmd($vmid, "nbd-server-start", addr => { type => 'inet', data => { host => "${localip}", port => "${storage_migrate_port}" } } );
>> +	    $nbd_protocol_version //= 0;
>> +
>> +	    my $migrate_storage_uri;
>> +	    # nbd_protocol_version > 0 for unix socket support
>> +	    if ($nbd_protocol_version > 0 && $migration_type eq 'secure') {
>> +		my $socket_path = "/run/qemu-server/$vmid\_nbd.migrate";
>> +		mon_cmd($vmid, "nbd-server-start", addr => { type => 'unix', data => { path => $socket_path } } );
>> +		$migrate_storage_uri = "nbd:unix:$socket_path";
>> +	    } else {
>> +		my $nodename = nodename();
>> +		my $localip = $get_migration_ip->($migration_network, $nodename);
>> +		my $pfamily = PVE::Tools::get_host_address_family($nodename);
>> +		my $storage_migrate_port = PVE::Tools::next_migrate_port($pfamily);
>>   
>> -	    $localip = "[$localip]" if Net::IP::ip_is_ipv6($localip);
>> +		mon_cmd($vmid, "nbd-server-start", addr => { type => 'inet', data => { host => "${localip}", port => "${storage_migrate_port}" } } );
>> +		$localip = "[$localip]" if Net::IP::ip_is_ipv6($localip);
>> +		$migrate_storage_uri = "nbd:${localip}:${storage_migrate_port}";
>> +	    }
>>   
>>   	    foreach my $opt (sort keys %$local_volumes) {
>>   		my $drivestr = $local_volumes->{$opt};
>>   		mon_cmd($vmid, "nbd-server-add", device => "drive-$opt", writable => JSON::true );
>> -		my $migrate_storage_uri = "nbd:${localip}:${storage_migrate_port}:exportname=drive-$opt";
>> -		print "storage migration listens on $migrate_storage_uri volume:$drivestr\n";
>> +		if ($nbd_protocol_version > 0 && $migration_type eq 'secure') {
>> +		    print "storage migration listens on $migrate_storage_uri:exportname=drive-$opt volume:$drivestr\n";
>> +		} else {
>> +		    print "storage migration listens on $migrate_storage_uri:exportname=drive-$opt volume:$drivestr\n";
>> +		}
> 
> What's the idea of this if?

thanks for catching, this was obviously a remnant of v1 where these two 
branches built the printed $migrate_storage_uri. pushed a followup:

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 21fb1b1..e022141 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -5008,11 +5008,7 @@ sub vm_start {
 	    foreach my $opt (sort keys %$local_volumes) {
 		my $drivestr = $local_volumes->{$opt};
 		mon_cmd($vmid, "nbd-server-add", device => "drive-$opt", writable => JSON::true );
-		if ($nbd_protocol_version > 0 && $migration_type eq 'secure') {
-		    print "storage migration listens on $migrate_storage_uri:exportname=drive-$opt volume:$drivestr\n";
-		} else {
-		    print "storage migration listens on $migrate_storage_uri:exportname=drive-$opt volume:$drivestr\n";
-		}
+		print "storage migration listens on $migrate_storage_uri:exportname=drive-$opt volume:$drivestr\n";
 	    }
 	}
 
> 
>>   	    }
>>   	}
>>   
>> 
>