Re: [pve-devel] [PATCH storage] api: fix get content call for volumes

[Christian Ebner <c.ebner@proxmox.com>]

> On 06.03.2023 11:17 CET Fiona Ebner <f.ebner@proxmox.com> wrote:
> 
>  
> Am 06.03.23 um 10:37 schrieb Christian Ebner:
> > `pvesh get /nodes/{node}/storage/{storage}/content/{volume}` failed for
> > several storage types, because the respective storage plugins returned
> > only the volumes `size` on `volume_size_info` calls, while also the format
> > is required.
> > 
> > This patch fixes the issue by returning also `format` and `used`, the
> > latter also being a non-optional return value for the api call.
> > 
> > The issue was reported in the forum:
> > https://forum.proxmox.com/threads/pvesh-get-nodes-node-storage-storage-content-volume-returns-error.123747/
> > 
> > Signed-off-by: Christian Ebner <c.ebner@proxmox.com>
> > ---
> >  PVE/API2/Storage/Content.pm      | 2 +-
> >  PVE/Storage/ISCSIDirectPlugin.pm | 2 +-
> >  PVE/Storage/RBDPlugin.pm         | 2 +-
> >  PVE/Storage/ZFSPoolPlugin.pm     | 2 +-
> >  4 files changed, 4 insertions(+), 4 deletions(-)
> > 
> > diff --git a/PVE/API2/Storage/Content.pm b/PVE/API2/Storage/Content.pm
> > index fe0ad4a..36433ba 100644
> > --- a/PVE/API2/Storage/Content.pm
> > +++ b/PVE/API2/Storage/Content.pm
> > @@ -324,7 +324,7 @@ __PACKAGE__->register_method ({
> >  
> >  	my $path = PVE::Storage::path($cfg, $volid);
> >  	my ($size, $format, $used, $parent) =  PVE::Storage::volume_size_info($cfg, $volid);
> > -	die "volume_size_info on '$volid' failed\n" if !($format && $size);
> > +	die "volume_size_info on '$volid' failed\n" if !($format && $size && $used);
> 
> This change should be it's own patch and I think it's wrong. Can't $used
> be zero and valid, e.g. for a newly created empty image? You'd either
> need to use defined($used) or leave it as-is, i.e. not failing and
> defaulting to 0 when $used is undef. Even with the defined() check, this
> would break an external plugin that doesn't return $used. While I guess
> that could be tolerated, we might do it together with the next APIAGE
> reset and document that volume_size_info explicitly requires it.

Yes, this was a really sloppy oversight, only added after my testing. On the other hand, should the API call fail for volumes reporting $size = 0 here? Is this intentional or should this also be fixed?

> 
> >  
> >  	my $entry = {
> >  	    path => $path,
> > diff --git a/PVE/Storage/ISCSIDirectPlugin.pm b/PVE/Storage/ISCSIDirectPlugin.pm
> > index 9777969..eb329d4 100644
> > --- a/PVE/Storage/ISCSIDirectPlugin.pm
> > +++ b/PVE/Storage/ISCSIDirectPlugin.pm
> > @@ -208,7 +208,7 @@ sub volume_size_info {
> >      my $vollist = iscsi_ls($scfg,$storeid);
> >      my $info = $vollist->{$storeid}->{$volname};
> >  
> > -    return $info->{size};
> > +    return wantarray ? ($info->{size}, 'raw', 0, undef) : $info->{size};
> 
> Why return 0 for $used? Doesn't the API call then fail because of the
> check you added above?
> 
> >  }
> >  
> >  sub volume_resize {
> > diff --git a/PVE/Storage/RBDPlugin.pm b/PVE/Storage/RBDPlugin.pm
> > index 9047504..e69c44c 100644
> > --- a/PVE/Storage/RBDPlugin.pm
> > +++ b/PVE/Storage/RBDPlugin.pm
> > @@ -730,7 +730,7 @@ sub volume_size_info {
> >  
> >      my ($vtype, $name, $vmid) = $class->parse_volname($volname);
> >      my ($size, undef) = rbd_volume_info($scfg, $storeid, $name);
> > -    return $size;
> > +    return wantarray ? ($size, 'raw', 0, undef) : $size;
> 
> Also, always returning undef for the parent is also not correct for RBD
> and ZFS.

What's the cheapest way here to get the parent for ZFS and RBD?

> 
> >  }
> >  
> >  sub volume_resize {
> > diff --git a/PVE/Storage/ZFSPoolPlugin.pm b/PVE/Storage/ZFSPoolPlugin.pm
> > index 9fbd149..90fc576 100644
> > --- a/PVE/Storage/ZFSPoolPlugin.pm
> > +++ b/PVE/Storage/ZFSPoolPlugin.pm
> > @@ -452,7 +452,7 @@ sub volume_size_info {
> >      my $attr = $format eq 'subvol' ? 'refquota' : 'volsize';
> >      my $value = $class->zfs_get_properties($scfg, $attr, "$scfg->{pool}/$vname");
> >      if ($value =~ /^(\d+)$/) {
> > -	return $1;
> > +	return wantarray ? ($1, $format, 0, undef) : $1;
> >      }
> >  
> >      die "Could not get zfs volume size\n";