[pve-devel] [PATCH storage v3] fix #4272: btrfs: add rename feature

[Aaron Lauterer]

gave it a try and it does what it should.
by enabling the rename feature only for `raw` we avoid potential 
pitfalls if we encounter a non regular situation on BTRFS. For example, 
an images/{vmid}/vm-{vmid}-disk-X.qcow2 file directly instead of the 
images/{vmid}/vm-{vmid}-disk-X/disk.raw as is the way the BTRFS plugin 
handles it in subvolumes.

But if we add the following diff, it seems to handle the case of a qcow2 
file in the same directory structure just fine:

diff --git a/src/PVE/Storage/BTRFSPlugin.pm b/src/PVE/Storage/BTRFSPlugin.pm
index 7376ae4..143442c 100644
--- a/src/PVE/Storage/BTRFSPlugin.pm
+++ b/src/PVE/Storage/BTRFSPlugin.pm
@@ -619,7 +619,7 @@ sub volume_has_feature {
             current => { qcow2 => 1, raw => 1, vmdk => 1 },
         },
         rename => {
-           current => { raw => 1 },
+           current => { qcow2 => 1, raw => 1},
         },
      };

@@ -939,6 +939,10 @@ sub rename_volume {

      my $format = ($class->parse_volname($source_volname))[6];

+    if ($format ne 'raw' && $format ne 'subvol') {
+       return $class->SUPER::rename_volume($scfg, $storeid, 
$source_volname, $target_vmid, $target_volname);
+    }
+
      my $ppath = $class->filesystem_path($scfg, $source_volname);

      $target_volname = $class->find_free_diskname($storeid, $scfg, 
$target_vmid, $format, 1)


Since we do have that in the other functions (alloc_image, free_image), 
we might want to add it here as well, just to be safe.

If we aren't concerned about this, then consider this:

Reviewed-By: Aaron Lauterer <a.lauterer at proxmox.com>
Tested-By: Aaron Lauterer <a.lauterer at proxmox.com>

On  2024-07-04  14:02, Maximiliano Sandoval wrote:
> Adds the ability to change the owner of a guest image.
> 
> Btrfs does not need special commands to rename a subvolume and this can
> be achieved the same as in Storage/plugin.pm's rename_volume taking
> special care of how the directory structure used by Btrfs.
> 
> Signed-off-by: Maximiliano Sandoval <m.sandoval at proxmox.com>
> ---
> Differences from v2:
>   - use indices instead of assigning to undef 5 times
> 
> Differences from v1:
>   - avoid assigning unused values of returned list to variables
> 
>   src/PVE/Storage/BTRFSPlugin.pm | 31 +++++++++++++++++++++++++++++++
>   1 file changed, 31 insertions(+)
> 
> diff --git a/src/PVE/Storage/BTRFSPlugin.pm b/src/PVE/Storage/BTRFSPlugin.pm
> index 42815cb..7376ae4 100644
> --- a/src/PVE/Storage/BTRFSPlugin.pm
> +++ b/src/PVE/Storage/BTRFSPlugin.pm
> @@ -618,6 +618,9 @@ sub volume_has_feature {
>   	    base => { qcow2 => 1, raw => 1, vmdk => 1 },
>   	    current => { qcow2 => 1, raw => 1, vmdk => 1 },
>   	},
> +	rename => {
> +	    current => { raw => 1 },
> +	},
>       };
>   
>       my ($vtype, $name, $vmid, $basename, $basevmid, $isBase, $format) = $class->parse_volname($volname);
> @@ -930,4 +933,32 @@ sub volume_import {
>       return "$storeid:$volname";
>   }
>   
> +sub rename_volume {
> +    my ($class, $scfg, $storeid, $source_volname, $target_vmid, $target_volname) = @_;
> +    die "no path found\n" if !$scfg->{path};
> +
> +    my $format = ($class->parse_volname($source_volname))[6];
> +
> +    my $ppath = $class->filesystem_path($scfg, $source_volname);
> +
> +    $target_volname = $class->find_free_diskname($storeid, $scfg, $target_vmid, $format, 1)
> +	if !$target_volname;
> +    $target_volname = "$target_vmid/$target_volname";
> +
> +    my $basedir = $class->get_subdir($scfg, 'images');
> +
> +    mkpath "${basedir}/${target_vmid}";
> +    my $source_dir = raw_name_to_dir($source_volname);
> +    my $target_dir = raw_name_to_dir($target_volname);
> +
> +    my $old_path = "${basedir}/${source_dir}";
> +    my $new_path = "${basedir}/${target_dir}";
> +
> +    die "target volume '${target_volname}' already exists\n" if -e $new_path;
> +    rename $old_path, $new_path ||
> +	die "rename '$old_path' to '$new_path' failed - $!\n";
> +
> +    return "${storeid}:$target_volname";
> +}
> +
>   1