[pve-devel] [PATCH v2 qemu-server] fix #4201: delete cloud-init disk on rollback

[pve-devel] [PATCH v2 qemu-server] fix #4201: delete cloud-init disk on rollback

[Mira Limbeck]

If the config doesn't contain the cloud-init disk anymore after the
rollback, we have to clean it up since otherwise no further disk can be
attached unless the one still existing on the storage is deleted.

Signed-off-by: Mira Limbeck <m.limbeck@proxmox.com>
---
v2:
 - chose the add_unused_volume way as @fiona recommended, the
   implementation is a lot cleaner, but contains a cloudinit regex

 - removed the 2nd patch for reusing already existing disks when
   adding a cloudinit disk

 PVE/QemuConfig.pm | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/PVE/QemuConfig.pm b/PVE/QemuConfig.pm
index 482c7ab..9fb8e9f 100644
--- a/PVE/QemuConfig.pm
+++ b/PVE/QemuConfig.pm
@@ -498,7 +498,7 @@ sub __snapshot_rollback_get_unused {
     $class->foreach_volume($conf, sub {
 	my ($vs, $volume) = @_;
 
-	return if PVE::QemuServer::drive_is_cdrom($volume);
+	return if PVE::QemuServer::drive_is_cdrom($volume, 1);
 
 	my $found = 0;
 	my $volid = $volume->{file};
@@ -507,7 +507,7 @@ sub __snapshot_rollback_get_unused {
 	    my ($ds, $drive) = @_;
 
 	    return if $found;
-	    return if PVE::QemuServer::drive_is_cdrom($drive);
+	    return if PVE::QemuServer::drive_is_cdrom($drive, 1);
 
 	    $found = 1
 		if ($drive->{file} && $drive->{file} eq $volid);
@@ -519,6 +519,19 @@ sub __snapshot_rollback_get_unused {
     return $unused;
 }
 
+sub add_unused_volume {
+    my ($class, $config, $volid) = @_;
+
+    if ($volid =~ m/vm-\d+-cloudinit/) {
+	print "found unused cloudinit disk '$volid', removing it\n";
+	my $storecfg = PVE::Storage::config();
+	PVE::Storage::vdisk_free($storecfg, $volid);
+	return undef;
+    } else {
+        return $class->SUPER::add_unused_volume($config, $volid);
+    }
+}
+
 # END implemented abstract methods from PVE::AbstractConfig
 
 sub has_cloudinit {
-- 
2.30.2

Re: [pve-devel] [PATCH v2 qemu-server] fix #4201: delete cloud-init disk on rollback

[Stefan Hanreich]

Test Setup:
I created a new VM, without any Cloud-Init drive, and immediately 
created a snapshot. Then I setup a Cloud-Init drive according to the PVE 
documentation via CLI. I created another snapshot of this state with a 
Cloud-Init drive.

What I tested:
- Rolling back to the older snapshot without Cloud-Init drive, it got 
successfully removed.
- Rolling back to the newer snapshot that includes a Cloud-Init drive, 
it successfully showed up afterwards.

I also tested both of those cases with Cloud-Init drives created from 
the Web UI, in case there are any differences.

Some additional tests including normal CD-ROM drives I did as well - 
just in case:
- Rolled back from a snapshot with only a Cloud-Init drive to a snapshot 
that contains only a CD-ROM drive, the CD-ROM drive showed up afterwards 
and removed the Cloud-Init drive successfully
- Rolled back from a snapshot with only a CD-ROM drive to a state that 
contains only a Cloud-Init drive, the Cloud-Init drive showed up 
afterwards and removed the CD-ROM drive successfully


Code LGTM


Reviewed-by: Stefan Hanreich <s.hanreich@proxmox.com>
Tested-by: Stefan Hanreich <s.hanreich@proxmox.com>

On 10/20/22 17:22, Mira Limbeck wrote:
> If the config doesn't contain the cloud-init disk anymore after the
> rollback, we have to clean it up since otherwise no further disk can be
> attached unless the one still existing on the storage is deleted.
>
> Signed-off-by: Mira Limbeck <m.limbeck@proxmox.com>
> ---
> v2:
>   - chose the add_unused_volume way as @fiona recommended, the
>     implementation is a lot cleaner, but contains a cloudinit regex
>
>   - removed the 2nd patch for reusing already existing disks when
>     adding a cloudinit disk
>
>   PVE/QemuConfig.pm | 17 +++++++++++++++--
>   1 file changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/PVE/QemuConfig.pm b/PVE/QemuConfig.pm
> index 482c7ab..9fb8e9f 100644
> --- a/PVE/QemuConfig.pm
> +++ b/PVE/QemuConfig.pm
> @@ -498,7 +498,7 @@ sub __snapshot_rollback_get_unused {
>       $class->foreach_volume($conf, sub {
>   	my ($vs, $volume) = @_;
>   
> -	return if PVE::QemuServer::drive_is_cdrom($volume);
> +	return if PVE::QemuServer::drive_is_cdrom($volume, 1);
>   
>   	my $found = 0;
>   	my $volid = $volume->{file};
> @@ -507,7 +507,7 @@ sub __snapshot_rollback_get_unused {
>   	    my ($ds, $drive) = @_;
>   
>   	    return if $found;
> -	    return if PVE::QemuServer::drive_is_cdrom($drive);
> +	    return if PVE::QemuServer::drive_is_cdrom($drive, 1);
>   
>   	    $found = 1
>   		if ($drive->{file} && $drive->{file} eq $volid);
> @@ -519,6 +519,19 @@ sub __snapshot_rollback_get_unused {
>       return $unused;
>   }
>   
> +sub add_unused_volume {
> +    my ($class, $config, $volid) = @_;
> +
> +    if ($volid =~ m/vm-\d+-cloudinit/) {
> +	print "found unused cloudinit disk '$volid', removing it\n";
> +	my $storecfg = PVE::Storage::config();
> +	PVE::Storage::vdisk_free($storecfg, $volid);
> +	return undef;
> +    } else {
> +        return $class->SUPER::add_unused_volume($config, $volid);
> +    }
> +}
> +
>   # END implemented abstract methods from PVE::AbstractConfig
>   
>   sub has_cloudinit {

Re: [pve-devel] [PATCH v2 qemu-server] fix #4201: delete cloud-init disk on rollback

[Mira Limbeck]

On 11/11/22 16:18, Stefan Hanreich wrote:
> Test Setup:
> I created a new VM, without any Cloud-Init drive, and immediately 
> created a snapshot. Then I setup a Cloud-Init drive according to the 
> PVE documentation via CLI. I created another snapshot of this state 
> with a Cloud-Init drive.
>
> What I tested:
> - Rolling back to the older snapshot without Cloud-Init drive, it got 
> successfully removed.
> - Rolling back to the newer snapshot that includes a Cloud-Init drive, 
> it successfully showed up afterwards.
>
> I also tested both of those cases with Cloud-Init drives created from 
> the Web UI, in case there are any differences.
>
> Some additional tests including normal CD-ROM drives I did as well - 
> just in case:
> - Rolled back from a snapshot with only a Cloud-Init drive to a 
> snapshot that contains only a CD-ROM drive, the CD-ROM drive showed up 
> afterwards and removed the Cloud-Init drive successfully
> - Rolled back from a snapshot with only a CD-ROM drive to a state that 
> contains only a Cloud-Init drive, the Cloud-Init drive showed up 
> afterwards and removed the CD-ROM drive successfully
>
>
> Code LGTM
>
>
> Reviewed-by: Stefan Hanreich <s.hanreich@proxmox.com>
> Tested-by: Stefan Hanreich <s.hanreich@proxmox.com>
>
Thanks for testing! Since it requires a rebase, I'll send a rebased v3 
with your R-b and T-b tags.