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

[Christian Ebner]

> On 06.03.2023 11:52 CET Fiona Ebner <f.ebner at proxmox.com> wrote:
> 
>  
> Am 06.03.23 um 11:36 schrieb Christian Ebner:
> > 
> >> On 06.03.2023 11:17 CET Fiona Ebner <f.ebner at 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 at 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?
> 
> I don't think there are valid cases where $size is 0, or?
> 
> >>
> >>>  
> >>>  	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?
> 
> I think parse_volname() should already give it to you. It's encoded in
> the volume ID.

Okay, I will have a look and incorporate this in a version 2, thank you for the input!