Re: [pve-devel] [PATCH v1 storage 2/9] add disk rename feature

[Fabian Ebner <f.ebner@proxmox.com>]

Am 19.07.21 um 16:52 schrieb Aaron Lauterer:
> Functionality has been added for the following storage types:
> 
> * directory ones, based on the default implementation:
>      * directory
>      * NFS
>      * CIFS
>      * gluster
> * ZFS
> * (thin) LVM
> * Ceph
> 
> A new feature `rename` has been introduced to mark which storage
> plugin supports the feature.
> 
> Version API and AGE have been bumped.
> 
> The storage gets locked and each plugin checks if the target volume
> already exists prior renaming.
> This is done because there could be a race condition from the time the
> external caller requests a new free disk name to the time the volume is
> actually renamed.
> 
> Signed-off-by: Aaron Lauterer <a.lauterer@proxmox.com>
> ---
> rfc -> v1:
> * reduced number of parameters to minimum needed, plugins infer needed
>    information themselves
> * added storage locking and checking if volume already exists
> * parse target_volname prior to renaming to check if valid
> 
> old dedicated API endpoint -> rfc:
> only do rename now but the rename function handles templates and returns
> the new volid as this can be differently handled on some storages.
> 
>   PVE/Storage.pm               | 20 +++++++++++--
>   PVE/Storage/LVMPlugin.pm     | 27 +++++++++++++++++
>   PVE/Storage/LvmThinPlugin.pm |  1 +
>   PVE/Storage/Plugin.pm        | 58 ++++++++++++++++++++++++++++++++++++
>   PVE/Storage/RBDPlugin.pm     | 29 ++++++++++++++++++
>   PVE/Storage/ZFSPoolPlugin.pm | 24 +++++++++++++++
>   6 files changed, 157 insertions(+), 2 deletions(-)
> 
> diff --git a/PVE/Storage.pm b/PVE/Storage.pm
> index afeb2e3..f6d86e1 100755
> --- a/PVE/Storage.pm
> +++ b/PVE/Storage.pm
> @@ -41,11 +41,11 @@ use PVE::Storage::PBSPlugin;
>   use PVE::Storage::BTRFSPlugin;
>   
>   # Storage API version. Increment it on changes in storage API interface.
> -use constant APIVER => 9;
> +use constant APIVER => 10;
>   # Age is the number of versions we're backward compatible with.
>   # This is like having 'current=APIVER' and age='APIAGE' in libtool,
>   # see https://www.gnu.org/software/libtool/manual/html_node/Libtool-versioning.html
> -use constant APIAGE => 0;
> +use constant APIAGE => 1;
>   
>   # load standard plugins
>   PVE::Storage::DirPlugin->register();
> @@ -360,6 +360,7 @@ sub volume_snapshot_needs_fsfreeze {
>   #            snapshot - taking a snapshot is possible
>   #            sparseinit - volume is sparsely initialized
>   #            template - conversion to base image is possible
> +#            rename - renaming volumes is possible
>   # $snap - check if the feature is supported for a given snapshot
>   # $running - if the guest owning the volume is running
>   # $opts - hash with further options:
> @@ -1868,6 +1869,21 @@ sub complete_volume {
>       return $res;
>   }
>   
> +sub rename_volume {
> +    my ($cfg, $source_volid, $target_volname) = @_;
> +
> +    my ($storeid) = parse_volume_id($source_volid);
> +
> +    activate_storage($cfg, $storeid);
> +
> +    my $scfg = storage_config($cfg, $storeid);
> +    my $plugin = PVE::Storage::Plugin->lookup($scfg->{type});
> +
> +    return $plugin->cluster_lock_storage($storeid, $scfg->{shared}, undef, sub {
> +	return $plugin->rename_volume($scfg, $storeid, $source_volid, $target_volname);

I know I suggested these parameters last time, but I hadn't worked it 
out in detail, and using $source_volname instead of $source_volid seems 
to be possible and nicer (would avoid some calls in the plugins AFAICS).

> +    });
> +}
> +
>   # Various io-heavy operations require io/bandwidth limits which can be
>   # configured on multiple levels: The global defaults in datacenter.cfg, and
>   # per-storage overrides. When we want to do a restore from storage A to storage
> diff --git a/PVE/Storage/LVMPlugin.pm b/PVE/Storage/LVMPlugin.pm
> index 3e5b6c8..7a13a96 100644
> --- a/PVE/Storage/LVMPlugin.pm
> +++ b/PVE/Storage/LVMPlugin.pm
> @@ -344,6 +344,16 @@ sub lvcreate {
>       run_command($cmd, errmsg => "lvcreate '$vg/$name' error");
>   }
>   
> +sub lvrename {
> +    my ($vg, $oldname, $newname) = @_;
> +
> +    my $cmd = ['/sbin/lvrename', $vg, $oldname, $newname];

$cmd is not used

> +    run_command(
> +	['/sbin/lvrename', $vg, $oldname, $newname],
> +	errmsg => "lvrename '${vg}/${oldname}' to '${newname}' error"
> +    );
> +}
> +
>   sub alloc_image {
>       my ($class, $storeid, $scfg, $vmid, $fmt, $name, $size) = @_;
>   
> @@ -589,6 +599,7 @@ sub volume_has_feature {
>   
>       my $features = {
>   	copy => { base => 1, current => 1},
> +	rename => {current => 1},
>       };
>   
>       my ($vtype, $name, $vmid, $basename, $basevmid, $isBase) =
> @@ -697,4 +708,20 @@ sub volume_import_write {
>   	input => '<&'.fileno($input_fh));
>   }
>   
> +sub rename_volume {
> +    my ($class, $scfg, $storeid, $source_volid, $target_volname) = @_;
> +
> +    $class->parse_volname($target_volname);
> +
> +    my (undef, $source_volname) =  PVE::Storage::Plugin::parse_volume_id($source_volid); > +
> +    my $vg = $scfg->{vgname};
> +    my $lvs = lvm_list_volumes($vg);
> +    die "target volume '${target_volname}' already exists\n"
> +	if ($lvs->{$vg}->{$target_volname});
> +
> +    lvrename($scfg->{vgname}, $source_volname, $target_volname);

Nit: $vg can be re-used

> +    return "${storeid}:${target_volname}";
> +}
> +
>   1;
> diff --git a/PVE/Storage/LvmThinPlugin.pm b/PVE/Storage/LvmThinPlugin.pm
> index 4ba6f90..c24af22 100644
> --- a/PVE/Storage/LvmThinPlugin.pm
> +++ b/PVE/Storage/LvmThinPlugin.pm
> @@ -355,6 +355,7 @@ sub volume_has_feature {
>   	template => { current => 1},
>   	copy => { base => 1, current => 1, snap => 1},
>   	sparseinit => { base => 1, current => 1},
> +	rename => {current => 1},
>       };
>   
>       my ($vtype, $name, $vmid, $basename, $basevmid, $isBase) =
> diff --git a/PVE/Storage/Plugin.pm b/PVE/Storage/Plugin.pm
> index 5c6c659..3f38a94 100644
> --- a/PVE/Storage/Plugin.pm
> +++ b/PVE/Storage/Plugin.pm
> @@ -967,6 +967,7 @@ sub volume_has_feature {
>   		  snap => {qcow2 => 1} },
>   	sparseinit => { base => {qcow2 => 1, raw => 1, vmdk => 1},
>   			current => {qcow2 => 1, raw => 1, vmdk => 1} },
> +	rename => { current =>{qcow2 => 1, raw => 1, vmdk => 1} },

Style nit: missing space

>       };
>   
>       # clone_image creates a qcow2 volume
> @@ -974,6 +975,14 @@ sub volume_has_feature {
>   		defined($opts->{valid_target_formats}) &&
>   		!(grep { $_ eq 'qcow2' } @{$opts->{valid_target_formats}});
>   
> +    if (
> +	$feature eq 'rename'
> +	&& $class->can('api')
> +	&& $class->api() < 9

Should be < 10 now like below.

> +    ) {
> +	return 0;
> +    }
> +
>       my ($vtype, $name, $vmid, $basename, $basevmid, $isBase, $format) =
>   	$class->parse_volname($volname);
>   
> @@ -1491,4 +1500,53 @@ sub volume_import_formats {
>       return ();
>   }
>   
> +sub rename_volume {
> +    my ($class, $scfg, $storeid, $source_volid, $target_volname) = @_;
> +    die "not implemented in storage plugin '$class'\n" if $class->can('api') && $class->api() < 10;

Could also die if there is no $scfg->{path} (so that PBS, ISCSI, etc. 
die if the method is ever called for them).

> +
> +    my $target_vmid;
> +
> +    if ($target_volname =~ m/^(base|vm)?-(\d+)-\S+$/) {
> +	$target_vmid = $2;
> +    } else {
> +	die "could not parse target vmid\n";
> +    }
> +
> +    $class->parse_volname("${target_vmid}/${target_volname}");

So the $target_volname that's passed in here is not an actual volname by 
our "definition", i.e. something that can be parsed by parse_volname. 
And passing in an actual volname like '123/vm-123-disk-0.raw' doesn't work.

> +
> +    my (undef, $source_volname) =  PVE::Storage::Plugin::parse_volume_id($source_volid);
> +    my (
> +	undef,
> +	$source_name,
> +	$source_vmid,
> +	$base_name,
> +	$base_vmid,
> +	undef,
> +	$format
> +    ) = $class->parse_volname($source_volname);
> +
> +    my $basedir = $class->get_subdir($scfg, 'images');
> +    # $source_volname includes the '<vmid>/' prefix
> +    my $sourcedir = "${basedir}/${source_vmid}";
> +    my $targetdir = "${basedir}/${target_vmid}";
> +
> +    mkpath $targetdir;
> +
> +    if ($target_volname !~ m/(vm|subsvol)-\d+-\S+\.(raw|qcow2|vmdk)$/) {
> +	$target_volname = "${target_volname}.${format}";
> +    }

parse_volname for the target didn't fail, so no need for this check.

> +
> +    my $old_path = "${sourcedir}/${source_name}";
> +    my $new_path = "${targetdir}/${target_volname}";
> +
> +    die "target volume '${target_volname}' already exists\n" if -e $new_path;
> +
> +    my $base = $base_name ? "${base_vmid}/${base_name}/" : '';
> +
> +    rename($old_path, $new_path) ||
> +	die "rename '$old_path' to '$new_path' failed - $!\n";
> +
> +    return "${storeid}:${base}${target_vmid}/${target_volname}";
> +}
> +
>   1;
> diff --git a/PVE/Storage/RBDPlugin.pm b/PVE/Storage/RBDPlugin.pm
> index 86ea45a..6ae846a 100644
> --- a/PVE/Storage/RBDPlugin.pm
> +++ b/PVE/Storage/RBDPlugin.pm
> @@ -733,6 +733,7 @@ sub volume_has_feature {
>   	template => { current => 1},
>   	copy => { base => 1, current => 1, snap => 1},
>   	sparseinit => { base => 1, current => 1},
> +	rename => {current => 1},
>       };
>   
>       my ($vtype, $name, $vmid, $basename, $basevmid, $isBase) = $class->parse_volname($volname);
> @@ -748,4 +749,32 @@ sub volume_has_feature {
>       return undef;
>   }
>   
> +sub rename_volume {
> +    my ($class, $scfg, $storeid, $source_volid, $target_volname) = @_;
> +
> +    $class->parse_volname($target_volname);
> +
> +    my (undef, $source_volname) =  PVE::Storage::Plugin::parse_volume_id($source_volid);
> +    my (undef, undef, $source_vmid, $base_name) = $class->parse_volname($source_volname);
> +
> +    eval {
> +	my $cmd = $rbd_cmd->($scfg, $storeid, 'info', $target_volname);
> +	run_rbd_command($cmd, errmsg => "exist check",  quiet => 1, noerr => 1);
> +    };
> +    my $err = $@;
> +    die "target volume '${target_volname}' already exists\n"
> +	if !$err;
> +
> +    my $cmd = $rbd_cmd->($scfg, $storeid, 'rename', $source_volname, $target_volname);
> +
> +    run_rbd_command(
> +	$cmd,
> +	errmsg => "could not rename image '${source_volname}' to '${target_volname}'",
> +    );
> +
> +    $base_name = $base_name ? "${base_name}/" : '';
> +
> +    return "${storeid}:${base_name}${target_volname}";
> +}
> +
>   1;
> diff --git a/PVE/Storage/ZFSPoolPlugin.pm b/PVE/Storage/ZFSPoolPlugin.pm
> index 85e2211..ac375e8 100644
> --- a/PVE/Storage/ZFSPoolPlugin.pm
> +++ b/PVE/Storage/ZFSPoolPlugin.pm
> @@ -692,6 +692,7 @@ sub volume_has_feature {
>   	copy => { base => 1, current => 1},
>   	sparseinit => { base => 1, current => 1},
>   	replicate => { base => 1, current => 1},
> +	rename => {current => 1},
>       };
>   
>       my ($vtype, $name, $vmid, $basename, $basevmid, $isBase) =
> @@ -794,4 +795,27 @@ sub volume_import_formats {
>       return $class->volume_export_formats($scfg, $storeid, $volname, $snapshot, $base_snapshot, $with_snapshots);
>   }
>   
> +sub rename_volume {
> +    my ($class, $scfg, $storeid, $source_volid, $target_volname) = @_;
> +
> +    $class->parse_volname($target_volname);
> +
> +    my (undef, $source_volname) = PVE::Storage::Plugin::parse_volume_id($source_volid);
> +    my (undef, undef, $source_vmid, $base_name) = $class->parse_volname($source_volname);
> +
> +    my $pool = $scfg->{pool};
> +    my $source_zfspath = "${pool}/${source_volname}";
> +    my $target_zfspath = "${pool}/${target_volname}";
> +
> +    my $exists = 0 == run_command(['zfs', 'get', '-H', 'name', $target_zfspath],
> +				  noerr => 1, quiet => 1);
> +    die "target volume '${target_volname}' already exists\n" if $exists;
> +
> +    $class->zfs_request($scfg, 5, 'rename', ${source_zfspath}, ${target_zfspath});
> +
> +    $base_name = $base_name ? "${base_name}/" : '';
> +
> +    return "${storeid}:${base_name}${target_volname}";
> +}
> +
>   1;
>