Re: [pve-devel] [PATCH v3 storage 3/4] storage_migrate: pull out import/export_prepare

[Fabian Ebner <f.ebner@proxmox.com>]

Am 22.12.21 um 14:52 schrieb Fabian Grünbichler:
> for re-use with remote migration, where import and export happen on
> different clusters connected via a websocket instead of SSH tunnel.
> 
> no semantic changes intended.
> 
> Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
> ---
> new in v3
> 
> using $opts across the board in storage_migrate to prevent future bugs
> where options get out of sync between helper calls..
> 
>   PVE/Storage.pm | 113 ++++++++++++++++++++++++++++++-------------------
>   1 file changed, 70 insertions(+), 43 deletions(-)
> 
> diff --git a/PVE/Storage.pm b/PVE/Storage.pm
> index 4f3a44a..976bd63 100755
> --- a/PVE/Storage.pm
> +++ b/PVE/Storage.pm
> @@ -651,16 +651,70 @@ sub storage_migrate_snapshot {
>       return $scfg->{type} eq 'zfspool' || $scfg->{type} eq 'btrfs';
>   }
>   
> -sub storage_migrate {
> -    my ($cfg, $volid, $target_sshinfo, $target_storeid, $opts, $logfunc) = @_;
> +my $volume_import_prepare = sub {
> +    my ($volid, $format, $path, $apiver, $opts) = @_;
>   
>       my $base_snapshot = $opts->{base_snapshot};
>       my $snapshot = $opts->{snapshot};
> -    my $ratelimit_bps = $opts->{ratelimit_bps};
> -    my $insecure = $opts->{insecure};
>       my $with_snapshots = $opts->{with_snapshots} ? 1 : 0;
> +    my $migration_snapshot = $opts->{migration_snapshot} ? 1 : 0;
>       my $allow_rename = $opts->{allow_rename} ? 1 : 0;
>   
> +    my $recv = ['pvesm', 'import', $volid, $format, $path, '-with-snapshots', $with_snapshots];
> +    if (defined($snapshot)) {
> +	push @$recv, '-snapshot', $snapshot;
> +    }
> +    if ($migration_snapshot) {
> +	push @$recv, '-delete-snapshot', $snapshot;
> +    }
> +    push @$recv, '-allow-rename', $allow_rename if $apiver >= 5;
> +
> +    if (defined($base_snapshot)) {
> +	# Check if the snapshot exists on the remote side:
> +	push @$recv, '-base', $base_snapshot if $apiver >= 9;
> +    }
> +
> +    return $recv;
> +};
> +
> +my $volume_export_prepare = sub {
> +    my ($cfg, $volid, $format, $logfunc, $opts) = @_;
> +    my $base_snapshot = $opts->{base_snapshot};
> +    my $snapshot = $opts->{snapshot};
> +    my $with_snapshots = $opts->{with_snapshots} ? 1 : 0;
> +    my $migration_snapshot = $opts->{migration_snapshot} ? 1 : 0;
> +    my $ratelimit_bps = $opts->{ratelimit_bps};
> +
> +    my $send = ['pvesm', 'export', $volid, $format, '-', '-with-snapshots', $with_snapshots];
> +    if (defined($snapshot)) {
> +	push @$send, '-snapshot', $snapshot;
> +    }
> +    if (defined($base_snapshot)) {
> +	push @$send, '-base', $base_snapshot;
> +    }
> +
> +    my @cstream;
> +    if (defined($ratelimit_bps)) {
> +	@cstream = [ '/usr/bin/cstream', '-t', $ratelimit_bps ];

Nit: It's Perl I guess and it seems to work, but assigning an array ref 
to an array looks weird to me. Why not keep the surrounding ( )? Or 
better, can't we just avoid wrapping the ref in an array altogether?

> +	$logfunc->("using a bandwidth limit of $ratelimit_bps bps for transferring '$volid'") if $logfunc; > +    }
> +
> +    volume_snapshot($cfg, $volid, $snapshot) if $migration_snapshot;
> +
> +    if (defined($snapshot)) {
> +	activate_volumes($cfg, [$volid], $snapshot);
> +    } else {
> +	activate_volumes($cfg, [$volid]);
> +    }
> +
> +    return [ $send, @cstream ];
> +};
> +
> +sub storage_migrate {
> +    my ($cfg, $volid, $target_sshinfo, $target_storeid, $opts, $logfunc) = @_;
> +
> +    my $insecure = $opts->{insecure};
> +
>       my ($storeid, $volname) = parse_volume_id($volid);
>   
>       my $scfg = storage_config($cfg, $storeid);
> @@ -688,19 +742,12 @@ sub storage_migrate {
>       my $ssh_base = PVE::SSHInfo::ssh_info_to_command_base($target_sshinfo);
>       local $ENV{RSYNC_RSH} = PVE::Tools::cmd2string($ssh_base);
>   
> -    my @cstream;
> -    if (defined($ratelimit_bps)) {
> -	@cstream = ([ '/usr/bin/cstream', '-t', $ratelimit_bps ]);
> -	$logfunc->("using a bandwidth limit of $ratelimit_bps bps for transferring '$volid'") if $logfunc;
> +    if (!defined($opts->{snapshot})) {
> +	$opts->{migration_snapshot} = storage_migrate_snapshot($cfg, $target_storeid);
> +	$opts->{snapshot} = '__migration__' if $opts->{migration_snapshot};
>       }
>   
> -    my $migration_snapshot;
> -    if (!defined($snapshot)) {
> -	$migration_snapshot = storage_migrate_snapshot->($cfg, $target_storeid);
> -	$snapshot = '__migration__' if $migration_snapshot;
> -    }
> -
> -    my @formats = volume_transfer_formats($cfg, $volid, $target_volid, $snapshot, $base_snapshot, $with_snapshots);
> +    my @formats = volume_transfer_formats($cfg, $volid, $target_volid, $opts->{snapshot}, $opts->{base_snapshot}, $opts->{with_snapshots});
>       die "cannot migrate from storage type '$scfg->{type}' to '$tcfg->{type}'\n" if !@formats;
>       my $format = $formats[0];
>   
> @@ -715,22 +762,7 @@ sub storage_migrate {
>       my $match_api_version = sub { $target_apiver = $1 if $_[0] =~ m!^APIVER (\d+)$!; };
>       eval { run_command($get_api_version, logfunc => $match_api_version); };
>   
> -    my $send = ['pvesm', 'export', $volid, $format, '-', '-with-snapshots', $with_snapshots];
> -    my $recv = [@$ssh, '--', 'pvesm', 'import', $target_volid, $format, $import_fn, '-with-snapshots', $with_snapshots];
> -    if (defined($snapshot)) {
> -	push @$send, '-snapshot', $snapshot;
> -	push @$recv, '-snapshot', $snapshot;
> -    }
> -    if ($migration_snapshot) {
> -	push @$recv, '-delete-snapshot', $snapshot;
> -    }
> -    push @$recv, '-allow-rename', $allow_rename if $target_apiver >= 5;
> -
> -    if (defined($base_snapshot)) {
> -	# Check if the snapshot exists on the remote side:
> -	push @$send, '-base', $base_snapshot;
> -	push @$recv, '-base', $base_snapshot if $target_apiver >= 9;
> -    }
> +    my $recv = [ @$ssh, '--', $volume_import_prepare->($target_volid, $format, $import_fn, $target_apiver, $opts)->@* ];
>   
>       my $new_volid;
>       my $pattern = volume_imported_message(undef, 1);
> @@ -745,19 +777,13 @@ sub storage_migrate {
>   	}
>       };
>   
> -    volume_snapshot($cfg, $volid, $snapshot) if $migration_snapshot;
> -
> -    if (defined($snapshot)) {
> -	activate_volumes($cfg, [$volid], $snapshot);
> -    } else {
> -	activate_volumes($cfg, [$volid]);
> -    }
> +    my $cmds = [ $volume_export_prepare->($cfg, $volid, $format, $logfunc, $opts)->@* ];
>   
>       eval {
>   	if ($insecure) {
>   	    my $input = IO::File->new();
>   	    my $info = IO::File->new();
> -	    open3($input, $info, $info, @{$recv})
> +	    open3($input, $info, $info, @$recv)
>   		or die "receive command failed: $!\n";
>   	    close($input);
>   
> @@ -774,7 +800,7 @@ sub storage_migrate {
>   	    # we won't be reading from the socket
>   	    shutdown($socket, 0);
>   
> -	    eval { run_command([$send, @cstream], output => '>&'.fileno($socket), errfunc => $logfunc); };
> +	    eval { run_command($cmds, output => '>&'.fileno($socket), errfunc => $logfunc); };
>   	    my $send_error = $@;
>   
>   	    # don't close the connection entirely otherwise the receiving end
> @@ -795,7 +821,8 @@ sub storage_migrate {
>   
>   	    die $send_error if $send_error;
>   	} else {
> -	    run_command([$send, @cstream, $recv], logfunc => $match_volid_and_log);
> +	    push @$cmds, $recv;
> +	    run_command($cmds, logfunc => $match_volid_and_log);
>   	}
>   
>   	die "unable to get ID of the migrated volume\n"
> @@ -803,8 +830,8 @@ sub storage_migrate {
>       };
>       my $err = $@;
>       warn "send/receive failed, cleaning up snapshot(s)..\n" if $err;
> -    if ($migration_snapshot) {
> -	eval { volume_snapshot_delete($cfg, $volid, $snapshot, 0) };
> +    if ($opts->{migration_snapshot}) {
> +	eval { volume_snapshot_delete($cfg, $volid, $opts->{snapshot}, 0) };
>   	warn "could not remove source snapshot: $@\n" if $@;
>       }
>       die $err if $err;