[pve-devel] [PATCH qemu-server v4 13/27] backup: keep track of block-node size for fleecing

[Fiona Ebner]

For fleecing, the size needs to match exactly what QEMU sees. In
particular, EFI disks might be attached with a 'size=' option, meaning
that size can be different from the volume's size. Commit 36377acf
("backup: disk info: also keep track of size") introduced size
tracking and it was used for fleecing since then, but the accurate
size information needs to be queried via QMP.

Should also help with the following issue reported in the community
forum:
https://forum.proxmox.com/threads/152202

Signed-off-by: Fiona Ebner <f.ebner at proxmox.com>
---

Changes in v4:
* avoid needlessly passing in $task ($disks is enough)

 PVE/VZDump/QemuServer.pm | 31 +++++++++++++++++++++++++++++--
 1 file changed, 29 insertions(+), 2 deletions(-)

diff --git a/PVE/VZDump/QemuServer.pm b/PVE/VZDump/QemuServer.pm
index c46e607c..2157d411 100644
--- a/PVE/VZDump/QemuServer.pm
+++ b/PVE/VZDump/QemuServer.pm
@@ -551,7 +551,7 @@ my sub allocate_fleecing_images {
 		my $name = "vm-$vmid-fleece-$n";
 		$name .= ".$format" if $scfg->{path};
 
-		my $size = PVE::Tools::convert_size($di->{size}, 'b' => 'kb');
+		my $size = PVE::Tools::convert_size($di->{'block-node-size'}, 'b' => 'kb');
 
 		$di->{'fleece-volid'} = PVE::Storage::vdisk_alloc(
 		    $self->{storecfg}, $fleecing_storeid, $vmid, $format, $name, $size);
@@ -600,7 +600,7 @@ my sub attach_fleecing_images {
 	    my $drive = "file=$path,if=none,id=$devid,format=$format,discard=unmap";
 	    # Specify size explicitly, to make it work if storage backend rounded up size for
 	    # fleecing image when allocating.
-	    $drive .= ",size=$di->{size}" if $format eq 'raw';
+	    $drive .= ",size=$di->{'block-node-size'}" if $format eq 'raw';
 	    $drive =~ s/\\/\\\\/g;
 	    my $ret = PVE::QemuServer::Monitor::hmp_cmd($vmid, "drive_add auto \"$drive\"", 60);
 	    die "attaching fleecing image $volid failed - $ret\n" if $ret !~ m/OK/s;
@@ -626,6 +626,8 @@ my sub check_and_prepare_fleecing {
     }
 
     if ($use_fleecing) {
+	$self->query_block_node_sizes($vmid, $disks);
+
 	my ($default_format, $valid_formats) = PVE::Storage::storage_default_format(
 	    $self->{storecfg}, $fleecing_opts->{storage});
 	my $format = scalar(grep { $_ eq 'qcow2' } $valid_formats->@*) ? 'qcow2' : 'raw';
@@ -1042,6 +1044,31 @@ sub qga_fs_thaw {
     $self->logerr($@) if $@;
 }
 
+# The size for fleecing images needs to be exactly the same size as QEMU sees. E.g. EFI disk can bex
+# attached with a smaller size then the underyling image on the storage.
+sub query_block_node_sizes {
+    my ($self, $vmid, $disks) = @_;
+
+    my $block_info = mon_cmd($vmid, "query-block");
+    $block_info = { map { $_->{device} => $_ } $block_info->@* };
+
+    for my $diskinfo ($disks->@*) {
+	my $drive_key = $diskinfo->{virtdev};
+	$drive_key .= "-backup" if $drive_key eq 'tpmstate0';
+	my $block_node_size =
+	    eval { $block_info->{"drive-$drive_key"}->{inserted}->{image}->{'virtual-size'}; };
+	if (!$block_node_size) {
+	    $self->loginfo(
+		"could not determine block node size of drive '$drive_key' - using fallback");
+	    $block_node_size = $diskinfo->{size}
+		or die "could not determine size of drive '$drive_key'\n";
+	}
+	$diskinfo->{'block-node-size'} = $block_node_size;
+    }
+
+    return;
+}
+
 # we need a running QEMU/KVM process for backup, starts a paused (prelaunch)
 # one if VM isn't already running
 sub enforce_vm_running_for_backup {
-- 
2.39.5