remove unneeded comment

[pve-storage.git] / src / PVE / Storage / Plugin.pm

package PVE::Storage::Plugin;

use strict;
use warnings;

use Cwd qw(abs_path);
use Encode qw(decode);
use Fcntl ':mode';
use File::chdir;
use File::Path;
use File::Basename;
use File::stat qw();

use PVE::Tools qw(run_command);
use PVE::JSONSchema qw(get_standard_option register_standard_option);
use PVE::Cluster qw(cfs_register_file);

use JSON;

use base qw(PVE::SectionConfig);

use constant KNOWN_COMPRESSION_FORMATS =>  ( 'gz', 'lzo', 'zst');
use constant COMPRESSOR_RE => join( '|', KNOWN_COMPRESSION_FORMATS);

use constant LOG_EXT => ".log";
use constant NOTES_EXT => ".notes";

our @COMMON_TAR_FLAGS = qw(
    --one-file-system
    -p --sparse --numeric-owner --acls
    --xattrs --xattrs-include=user.* --xattrs-include=security.capability
    --warning=no-file-ignored --warning=no-xattr-write
);

our @SHARED_STORAGE = (
    'iscsi',
    'nfs',
    'cifs',
    'rbd',
    'cephfs',
    'iscsidirect',
    'glusterfs',
    'zfs',
    'drbd',
    'pbs',
);

our $QCOW2_PREALLOCATION = {
    off => 1,
    metadata => 1,
    falloc => 1,
    full => 1,
};

our $RAW_PREALLOCATION = {
    off => 1,
    falloc => 1,
    full => 1,
};

our $MAX_VOLUMES_PER_GUEST = 1024;

cfs_register_file ('storage.cfg',
		   sub { __PACKAGE__->parse_config(@_); },
		   sub { __PACKAGE__->write_config(@_); });

my %prune_option = (
    optional => 1,
    type => 'integer', minimum => '0',
    format_description => 'N',
);

our $prune_backups_format = {
    'keep-all' => {
	type => 'boolean',
	description => 'Keep all backups. Conflicts with the other options when true.',
	optional => 1,
    },
    'keep-last' => {
	%prune_option,
	description => 'Keep the last <N> backups.',
    },
    'keep-hourly' => {
	%prune_option,
	description => 'Keep backups for the last <N> different hours. If there is more' .
		       'than one backup for a single hour, only the latest one is kept.'
    },
    'keep-daily' => {
	%prune_option,
	description => 'Keep backups for the last <N> different days. If there is more' .
		       'than one backup for a single day, only the latest one is kept.'
    },
    'keep-weekly' => {
	%prune_option,
	description => 'Keep backups for the last <N> different weeks. If there is more' .
		       'than one backup for a single week, only the latest one is kept.'
    },
    'keep-monthly' => {
	%prune_option,
	description => 'Keep backups for the last <N> different months. If there is more' .
		       'than one backup for a single month, only the latest one is kept.'
    },
    'keep-yearly' => {
	%prune_option,
	description => 'Keep backups for the last <N> different years. If there is more' .
		       'than one backup for a single year, only the latest one is kept.'
    },
};
PVE::JSONSchema::register_format('prune-backups', $prune_backups_format, \&validate_prune_backups);
sub validate_prune_backups {
    my ($prune_backups) = @_;

    my $res = { $prune_backups->%* };

    my $keep_all = delete $res->{'keep-all'};

    if (scalar(grep { $_ > 0 } values %{$res}) == 0) {
	$res = { 'keep-all' => 1 };
    } elsif ($keep_all) {
	die "keep-all cannot be set together with other options.\n";
    }

    return $res;
}
register_standard_option('prune-backups', {
    description => "The retention options with shorter intervals are processed first " .
		   "with --keep-last being the very first one. Each option covers a " .
		   "specific period of time. We say that backups within this period " .
		   "are covered by this option. The next option does not take care " .
		   "of already covered backups and only considers older backups.",
    optional => 1,
    type => 'string',
    format => 'prune-backups',
});

my $defaultData = {
    propertyList => {
	type => { description => "Storage type." },
	storage => get_standard_option('pve-storage-id',
	    { completion => \&PVE::Storage::complete_storage }),
	nodes => get_standard_option('pve-node-list', { optional => 1 }),
	content => {
	    description => "Allowed content types.\n\nNOTE: the value " .
		"'rootdir' is used for Containers, and value 'images' for VMs.\n",
	    type => 'string', format => 'pve-storage-content-list',
	    optional => 1,
	    completion => \&PVE::Storage::complete_content_type,
	},
	disable => {
	    description => "Flag to disable the storage.",
	    type => 'boolean',
	    optional => 1,
	},
	maxfiles => {
	    description => "Deprecated: use 'prune-backups' instead. " .
		"Maximal number of backup files per VM. Use '0' for unlimited.",
	    type => 'integer',
	    minimum => 0,
	    optional => 1,
	},
	'prune-backups' => get_standard_option('prune-backups'),
	'max-protected-backups' => {
	    description => "Maximal number of protected backups per guest. Use '-1' for unlimited.",
	    type => 'integer',
	    minimum => -1,
	    optional => 1,
	    default => "Unlimited for users with Datastore.Allocate privilege, 5 for other users",
	},
	shared => {
	    description => "Mark storage as shared.",
	    type => 'boolean',
	    optional => 1,
	},
	subdir => {
	    description => "Subdir to mount.",
	    type => 'string', format => 'pve-storage-path',
	    optional => 1,
	},
	'format' => {
	    description => "Default image format.",
	    type => 'string', format => 'pve-storage-format',
	    optional => 1,
	},
	preallocation => {
	    description => "Preallocation mode for raw and qcow2 images. " .
		"Using 'metadata' on raw images results in preallocation=off.",
	    type => 'string', enum => ['off', 'metadata', 'falloc', 'full'],
	    default => 'metadata',
	    optional => 1,
	},
	'content-dirs' => {
	    description => "Overrides for default content type directories.",
	    type => "string", format => "pve-dir-override-list",
	    optional => 1,
	},
	options => {
	    description => "NFS/CIFS mount options (see 'man nfs' or 'man mount.cifs')",
	    type => 'string',
	    format => 'pve-storage-options',
	    optional => 1,
	},
    },
};

sub content_hash_to_string {
    my $hash = shift;

    my @cta;
    foreach my $ct (keys %$hash) {
	push @cta, $ct if $hash->{$ct};
    }

    return join(',', @cta);
}

sub valid_content_types {
    my ($type) = @_;

    my $def = $defaultData->{plugindata}->{$type};

    return {} if !$def;

    return $def->{content}->[0];
}

sub dirs_hash_to_string {
    my $hash = shift;

    return join(',', map { "$_=$hash->{$_}" } sort keys %$hash);
}

sub default_format {
    my ($scfg) = @_;

    my $type = $scfg->{type};
    my $def = $defaultData->{plugindata}->{$type};

    my $def_format = 'raw';
    my $valid_formats = [ $def_format ];

    if (defined($def->{format})) {
	$def_format = $scfg->{format} || $def->{format}->[1];
	$valid_formats = [ sort keys %{$def->{format}->[0]} ];
    }

    return wantarray ? ($def_format, $valid_formats) : $def_format;
}

PVE::JSONSchema::register_format('pve-storage-path', \&verify_path);
sub verify_path {
    my ($path, $noerr) = @_;

    # fixme: exclude more shell meta characters?
    # we need absolute paths
    if ($path !~ m|^/[^;\(\)]+|) {
	return undef if $noerr;
	die "value does not look like a valid absolute path\n";
    }
    return $path;
}

PVE::JSONSchema::register_format('pve-storage-server', \&verify_server);
sub verify_server {
    my ($server, $noerr) = @_;

    if (!(PVE::JSONSchema::pve_verify_ip($server, 1) ||
          PVE::JSONSchema::pve_verify_dns_name($server, 1)))
    {
	return undef if $noerr;
	die "value does not look like a valid server name or IP address\n";
    }
    return $server;
}

PVE::JSONSchema::register_format('pve-storage-vgname', \&parse_lvm_name);
sub parse_lvm_name {
    my ($name, $noerr) = @_;

    if ($name !~ m/^[a-z0-9][a-z0-9\-\_\.]*[a-z0-9]$/i) {
	return undef if $noerr;
	die "lvm name '$name' contains illegal characters\n";
    }

    return $name;
}

# fixme: do we need this
#PVE::JSONSchema::register_format('pve-storage-portal', \&verify_portal);
#sub verify_portal {
#    my ($portal, $noerr) = @_;
#
#    # IP with optional port
#    if ($portal !~ m/^\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}(:\d+)?$/) {
#	return undef if $noerr;
#	die "value does not look like a valid portal address\n";
#    }
#    return $portal;
#}

PVE::JSONSchema::register_format('pve-storage-portal-dns', \&verify_portal_dns);
sub verify_portal_dns {
    my ($portal, $noerr) = @_;

    # IP or DNS name with optional port
    if (!PVE::Tools::parse_host_and_port($portal)) {
	return undef if $noerr;
	die "value does not look like a valid portal address\n";
    }
    return $portal;
}

PVE::JSONSchema::register_format('pve-storage-content', \&verify_content);
sub verify_content {
    my ($ct, $noerr) = @_;

    my $valid_content = valid_content_types('dir'); # dir includes all types

    if (!$valid_content->{$ct}) {
	return undef if $noerr;
	die "invalid content type '$ct'\n";
    }

    return $ct;
}

PVE::JSONSchema::register_format('pve-storage-format', \&verify_format);
sub verify_format {
    my ($fmt, $noerr) = @_;

    if ($fmt !~ m/(raw|qcow2|vmdk|subvol)/) {
	return undef if $noerr;
	die "invalid format '$fmt'\n";
    }

    return $fmt;
}

PVE::JSONSchema::register_format('pve-storage-options', \&verify_options);
sub verify_options {
    my ($value, $noerr) = @_;

    # mount options (see man fstab)
    if ($value !~ m/^\S+$/) {
	return undef if $noerr;
	die "invalid options '$value'\n";
    }

    return $value;
}

PVE::JSONSchema::register_format('pve-volume-id', \&parse_volume_id);
sub parse_volume_id {
    my ($volid, $noerr) = @_;

    if ($volid =~ m/^([a-z][a-z0-9\-\_\.]*[a-z0-9]):(.+)$/i) {
	return wantarray ? ($1, $2) : $1;
    }
    return undef if $noerr;
    die "unable to parse volume ID '$volid'\n";
}

PVE::JSONSchema::register_format('pve-dir-override', \&verify_dir_override);
sub verify_dir_override {
    my ($value, $noerr) = @_;

    if ($value =~ m/^([a-z]+)=([^.]*(?:\.?[^.]+)+)$/) {
	my ($content_type, $relative_path) = ($1, $2);
	if (verify_content($content_type, $noerr)) {
	    # linux has 4k max-path, but limit total length to lower as its concat'd for full path
	    if (length($relative_path) < 1023 && !(grep { length($_) >= 255 } split('/', $relative_path))) {
		return $value;
	    }
	}
    }

    return undef if $noerr;
    die "invalid override '$value'\n";
}

sub private {
    return $defaultData;
}

sub parse_section_header {
    my ($class, $line) = @_;

    if ($line =~ m/^(\S+):\s*(\S+)\s*$/) {
	my ($type, $storeid) = (lc($1), $2);
	my $errmsg = undef; # set if you want to skip whole section
	eval { PVE::JSONSchema::parse_storage_id($storeid); };
	$errmsg = $@ if $@;
	my $config = {}; # to return additional attributes
	return ($type, $storeid, $errmsg, $config);
    }
    return undef;
}

sub decode_value {
    my ($class, $type, $key, $value) = @_;

    my $def = $defaultData->{plugindata}->{$type};

    if ($key eq 'content') {
	my $valid_content = $def->{content}->[0];

	my $res = {};

	foreach my $c (PVE::Tools::split_list($value)) {
	    if (!$valid_content->{$c}) {
		warn "storage does not support content type '$c'\n";
		next;
	    }
	    $res->{$c} = 1;
	}

	if ($res->{none} && scalar (keys %$res) > 1) {
	    die "unable to combine 'none' with other content types\n";
	}

	if (scalar(keys $res->%*) == 0 && !$valid_content->{none}) {
	    die "storage does not support content type 'none'\n";
	}

	return $res;
    } elsif ($key eq 'format') {
	my $valid_formats = $def->{format}->[0];

	if (!$valid_formats->{$value}) {
	    warn "storage does not support format '$value'\n";
	    next;
	}

	return $value;
    } elsif ($key eq 'nodes') {
	my $res = {};

	foreach my $node (PVE::Tools::split_list($value)) {
	    if (PVE::JSONSchema::pve_verify_node_name($node)) {
		$res->{$node} = 1;
	    }
	}

	# fixme:
	# no node restrictions for local storage
	#if ($storeid && $storeid eq 'local' && scalar(keys(%$res))) {
	#    die "storage '$storeid' does not allow node restrictions\n";
	#}

	return $res;
    } elsif ($key eq 'content-dirs') {
	my $valid_content = $def->{content}->[0];
	my $res = {};

	foreach my $dir (PVE::Tools::split_list($value)) {
	    my ($content, $path) = split(/=/, $dir, 2);

	    if (!$valid_content->{$content}) {
		warn "storage does not support content type '$content'\n";
		next;
	    }

	    $res->{$content} = $path;
	}

	return $res;
    }

    return $value;
}

sub encode_value {
    my ($class, $type, $key, $value) = @_;

    if ($key eq 'nodes') {
	return join(',', keys(%$value));
    } elsif ($key eq 'content') {
	my $res = content_hash_to_string($value) || 'none';
	return $res;
    } elsif ($key eq 'content-dirs') {
	my $res = dirs_hash_to_string($value);
	return $res;
    }

    return $value;
}

sub parse_config {
    my ($class, $filename, $raw) = @_;

    my $cfg = $class->SUPER::parse_config($filename, $raw);
    my $ids = $cfg->{ids};

    # make sure we have a reasonable 'local:' storage
    # we want 'local' to be always the same 'type' (on all cluster nodes)
    if (!$ids->{local} || $ids->{local}->{type} ne 'dir' ||
	($ids->{local}->{path} && $ids->{local}->{path} ne '/var/lib/vz')) {
	$ids->{local} = {
	    type => 'dir',
	    priority => 0, # force first entry
	    path => '/var/lib/vz',
	    'prune-backups' => 'keep-all=1',
	    content => {
		backup => 1,
		images => 1,
		iso => 1,
		rootdir => 1,
		snippets => 1,
		vztmpl => 1,
	    },
	};
    }

    # make sure we have a path
    $ids->{local}->{path} = '/var/lib/vz' if !$ids->{local}->{path};

    # remove node restrictions for local storage
    delete($ids->{local}->{nodes});

    foreach my $storeid (keys %$ids) {
	my $d = $ids->{$storeid};
	my $type = $d->{type};

	my $def = $defaultData->{plugindata}->{$type};

	if ($def->{content}) {
	    $d->{content} = $def->{content}->[1] if !$d->{content};
	}
	if (grep { $_ eq $type }  @SHARED_STORAGE) {
	    $d->{shared} = 1;
	}
    }

    return $cfg;
}

sub preallocation_cmd_option {
    my ($scfg, $fmt) = @_;

    my $prealloc = $scfg->{preallocation};

    if ($fmt eq 'qcow2') {
	$prealloc = $prealloc // 'metadata';

	die "preallocation mode '$prealloc' not supported by format '$fmt'\n"
	    if !$QCOW2_PREALLOCATION->{$prealloc};

	return "preallocation=$prealloc";
    } elsif ($fmt eq 'raw') {
	$prealloc = $prealloc // 'off';
	$prealloc = 'off' if $prealloc eq 'metadata';

	die "preallocation mode '$prealloc' not supported by format '$fmt'\n"
	    if !$RAW_PREALLOCATION->{$prealloc};

	return "preallocation=$prealloc";
    }

    return;
}

# Storage implementation

# called during addition of storage (before the new storage config got written)
# die to abort addition if there are (grave) problems
# NOTE: runs in a storage config *locked* context
sub on_add_hook {
    my ($class, $storeid, $scfg, %param) = @_;

    # do nothing by default
    return undef;
}

# called during storage configuration update (before the updated storage config got written)
# die to abort the update if there are (grave) problems
# NOTE: runs in a storage config *locked* context
sub on_update_hook {
    my ($class, $storeid, $scfg, %param) = @_;

    # do nothing by default
    return undef;
}

# called during deletion of storage (before the new storage config got written)
# and if the activate check on addition fails, to cleanup all storage traces
# which on_add_hook may have created.
# die to abort deletion if there are (very grave) problems
# NOTE: runs in a storage config *locked* context
sub on_delete_hook {
    my ($class, $storeid, $scfg) = @_;

    # do nothing by default
    return undef;
}

sub cluster_lock_storage {
    my ($class, $storeid, $shared, $timeout, $func, @param) = @_;

    my $res;
    if (!$shared) {
	my $lockid = "pve-storage-$storeid";
	my $lockdir = "/var/lock/pve-manager";
	mkdir $lockdir;
	$res = PVE::Tools::lock_file("$lockdir/$lockid", $timeout, $func, @param);
	die $@ if $@;
    } else {
	$res = PVE::Cluster::cfs_lock_storage($storeid, $timeout, $func, @param);
	die $@ if $@;
    }
    return $res;
}

sub parse_name_dir {
    my $name = shift;

    if ($name =~ m!^((base-)?[^/\s]+\.(raw|qcow2|vmdk|subvol))$!) {
	return ($1, $3, $2); # (name, format, isBase)
    }

    die "unable to parse volume filename '$name'\n";
}

sub parse_volname {
    my ($class, $volname) = @_;

    if ($volname =~ m!^(\d+)/(\S+)/(\d+)/(\S+)$!) {
	my ($basedvmid, $basename) = ($1, $2);
	parse_name_dir($basename);
	my ($vmid, $name) = ($3, $4);
	my (undef, $format, $isBase) = parse_name_dir($name);
	return ('images', $name, $vmid, $basename, $basedvmid, $isBase, $format);
    } elsif ($volname =~ m!^(\d+)/(\S+)$!) {
	my ($vmid, $name) = ($1, $2);
	my (undef, $format, $isBase) = parse_name_dir($name);
	return ('images', $name, $vmid, undef, undef, $isBase, $format);
    } elsif ($volname =~ m!^iso/([^/]+$PVE::Storage::ISO_EXT_RE_0)$!) {
	return ('iso', $1);
    } elsif ($volname =~ m!^vztmpl/([^/]+$PVE::Storage::VZTMPL_EXT_RE_1)$!) {
	return ('vztmpl', $1);
    } elsif ($volname =~ m!^rootdir/(\d+)$!) {
	return ('rootdir', $1, $1);
    } elsif ($volname =~ m!^backup/([^/]+$PVE::Storage::BACKUP_EXT_RE_2)$!) {
	my $fn = $1;
	if ($fn =~ m/^vzdump-(openvz|lxc|qemu)-(\d+)-.+/) {
	    return ('backup', $fn, $2);
	}
	return ('backup', $fn);
    } elsif ($volname =~ m!^snippets/([^/]+)$!) {
	return ('snippets', $1);
    }

    die "unable to parse directory volume name '$volname'\n";
}

my $vtype_subdirs = {
    images => 'images',
    rootdir => 'private',
    iso => 'template/iso',
    vztmpl => 'template/cache',
    backup => 'dump',
    snippets => 'snippets',
};

sub get_vtype_subdirs {
    return $vtype_subdirs;
}

sub get_subdir {
    my ($class, $scfg, $vtype) = @_;

    my $path = $scfg->{path};

    die "storage definition has no path\n" if !$path;
    die "unknown vtype '$vtype'\n" if !exists($vtype_subdirs->{$vtype});

    my $subdir = $scfg->{"content-dirs"}->{$vtype} // $vtype_subdirs->{$vtype};

    return "$path/$subdir";
}

sub filesystem_path {
    my ($class, $scfg, $volname, $snapname) = @_;

    my ($vtype, $name, $vmid, undef, undef, $isBase, $format) =
	$class->parse_volname($volname);

    # Note: qcow2/qed has internal snapshot, so path is always
    # the same (with or without snapshot => same file).
    die "can't snapshot this image format\n"
	if defined($snapname) && $format !~ m/^(qcow2|qed)$/;

    my $dir = $class->get_subdir($scfg, $vtype);

    $dir .= "/$vmid" if $vtype eq 'images';

    my $path = "$dir/$name";

    return wantarray ? ($path, $vmid, $vtype) : $path;
}

sub path {
    my ($class, $scfg, $volname, $storeid, $snapname) = @_;

    return $class->filesystem_path($scfg, $volname, $snapname);
}

sub create_base {
    my ($class, $storeid, $scfg, $volname) = @_;

    # this only works for file based storage types
    die "storage definition has no path\n" if !$scfg->{path};

    my ($vtype, $name, $vmid, $basename, $basevmid, $isBase, $format) =
	$class->parse_volname($volname);

    die "create_base on wrong vtype '$vtype'\n" if $vtype ne 'images';

    die "create_base not possible with base image\n" if $isBase;

    my $path = $class->filesystem_path($scfg, $volname);

    my ($size, undef, $used, $parent) = file_size_info($path);
    die "file_size_info on '$volname' failed\n" if !($format && defined($size));

    die "volname '$volname' contains wrong information about parent\n"
	if $basename && (!$parent || $parent ne "../$basevmid/$basename");

    my $newname = $name;
    $newname =~ s/^vm-/base-/;

    my $newvolname = $basename ? "$basevmid/$basename/$vmid/$newname" :
	"$vmid/$newname";

    my $newpath = $class->filesystem_path($scfg, $newvolname);

    die "file '$newpath' already exists\n" if -f $newpath;

    rename($path, $newpath) ||
	die "rename '$path' to '$newpath' failed - $!\n";

    # We try to protect base volume

    chmod(0444, $newpath); # nobody should write anything

    # also try to set immutable flag
    eval { run_command(['/usr/bin/chattr', '+i', $newpath]); };
    warn $@ if $@;

    return $newvolname;
}

my $get_vm_disk_number = sub {
    my ($disk_name, $scfg, $vmid, $suffix) = @_;

    my $disk_regex = qr/(vm|base)-$vmid-disk-(\d+)$suffix/;

    my $type = $scfg->{type};
    my $def = { %{$defaultData->{plugindata}->{$type}} };

    my $valid = $def->{format}[0];
    if ($valid->{subvol}) {
	$disk_regex = qr/(vm|base|subvol|basevol)-$vmid-disk-(\d+)/;
    }

    if ($disk_name =~ m/$disk_regex/) {
	return $2;
    }

    return undef;
};

sub get_next_vm_diskname {
    my ($disk_list, $storeid, $vmid, $fmt, $scfg, $add_fmt_suffix) = @_;

    $fmt //= '';
    my $prefix = ($fmt eq 'subvol') ? 'subvol' : 'vm';
    my $suffix = $add_fmt_suffix ? ".$fmt" : '';

    my $disk_ids = {};
    foreach my $disk (@$disk_list) {
	my $disknum = $get_vm_disk_number->($disk, $scfg, $vmid, $suffix);
	$disk_ids->{$disknum} = 1 if defined($disknum);
    }

    for (my $i = 0; $i < $MAX_VOLUMES_PER_GUEST; $i++) {
	if (!$disk_ids->{$i}) {
	    return "$prefix-$vmid-disk-$i$suffix";
	}
    }

    die "unable to allocate an image name for VM $vmid in storage '$storeid'\n"
}

sub find_free_diskname {
    my ($class, $storeid, $scfg, $vmid, $fmt, $add_fmt_suffix) = @_;

    my $disks = $class->list_images($storeid, $scfg, $vmid);

    my $disk_list = [ map { $_->{volid} } @$disks ];

    return get_next_vm_diskname($disk_list, $storeid, $vmid, $fmt, $scfg, $add_fmt_suffix);
}

sub clone_image {
    my ($class, $scfg, $storeid, $volname, $vmid, $snap) = @_;

    # this only works for file based storage types
    die "storage definition has no path\n" if !$scfg->{path};

    my ($vtype, $basename, $basevmid, undef, undef, $isBase, $format) =
	$class->parse_volname($volname);

    die "clone_image on wrong vtype '$vtype'\n" if $vtype ne 'images';

    die "this storage type does not support clone_image on snapshot\n" if $snap;

    die "this storage type does not support clone_image on subvolumes\n" if $format eq 'subvol';

    die "clone_image only works on base images\n" if !$isBase;

    my $imagedir = $class->get_subdir($scfg, 'images');
    $imagedir .= "/$vmid";

    mkpath $imagedir;

    my $name = $class->find_free_diskname($storeid, $scfg, $vmid, "qcow2", 1);

    warn "clone $volname: $vtype, $name, $vmid to $name (base=../$basevmid/$basename)\n";

    my $newvol = "$basevmid/$basename/$vmid/$name";

    my $path = $class->filesystem_path($scfg, $newvol);

    # Note: we use relative paths, so we need to call chdir before qemu-img
    eval {
	local $CWD = $imagedir;

	my $cmd = ['/usr/bin/qemu-img', 'create', '-b', "../$basevmid/$basename",
		   '-F', $format, '-f', 'qcow2', $path];

	run_command($cmd);
    };
    my $err = $@;

    die $err if $err;

    return $newvol;
}

sub alloc_image {
    my ($class, $storeid, $scfg, $vmid, $fmt, $name, $size) = @_;

    my $imagedir = $class->get_subdir($scfg, 'images');
    $imagedir .= "/$vmid";

    mkpath $imagedir;

    $name = $class->find_free_diskname($storeid, $scfg, $vmid, $fmt, 1) if !$name;

    my (undef, $tmpfmt) = parse_name_dir($name);

    die "illegal name '$name' - wrong extension for format ('$tmpfmt != '$fmt')\n"
	if $tmpfmt ne $fmt;

    my $path = "$imagedir/$name";

    die "disk image '$path' already exists\n" if -e $path;

    if ($fmt eq 'subvol') {
	# only allow this if size = 0, so that user knows what he is doing
	die "storage does not support subvol quotas\n" if $size != 0;

	my $old_umask = umask(0022);
	my $err;
	mkdir($path) or $err = "unable to create subvol '$path' - $!\n";
	umask $old_umask;
	die $err if $err;
    } else {
	my $cmd = ['/usr/bin/qemu-img', 'create'];

	my $prealloc_opt = preallocation_cmd_option($scfg, $fmt);
	push @$cmd, '-o', $prealloc_opt if defined($prealloc_opt);

	push @$cmd, '-f', $fmt, $path, "${size}K";

	eval { run_command($cmd, errmsg => "unable to create image"); };
	if ($@) {
	    unlink $path;
	    rmdir $imagedir;
	    die "$@";
	}
    }

    return "$vmid/$name";
}

sub free_image {
    my ($class, $storeid, $scfg, $volname, $isBase, $format) = @_;

    die "cannot remove protected volume '$volname' on '$storeid'\n"
	if $class->get_volume_attribute($scfg, $storeid, $volname, 'protected');

    my $path = $class->filesystem_path($scfg, $volname);

    if ($isBase) {
	# try to remove immutable flag
	eval { run_command(['/usr/bin/chattr', '-i', $path]); };
	warn $@ if $@;
    }

    if (defined($format) && ($format eq 'subvol')) {
	File::Path::remove_tree($path);
    } else {
	if (!(-f $path || -l $path)) {
	    warn "disk image '$path' does not exist\n";
	    return undef;
	}

	unlink($path) || die "unlink '$path' failed - $!\n";
    }

    # try to cleanup directory to not clutter storage with empty $vmid dirs if
    # all images from a guest got deleted
    my $dir = dirname($path);
    rmdir($dir);

    return undef;
}

sub file_size_info {
    my ($filename, $timeout) = @_;

    my $st = File::stat::stat($filename);

    if (!defined($st)) {
	my $extramsg = -l $filename ? ' - dangling symlink?' : '';
	warn "failed to stat '$filename'$extramsg\n";
	return undef;
    }

    if (S_ISDIR($st->mode)) {
	return wantarray ? (0, 'subvol', 0, undef, $st->ctime) : 1;
    }

    my $json = '';
    eval {
	run_command(['/usr/bin/qemu-img', 'info', '--output=json', $filename],
	    timeout => $timeout,
	    outfunc => sub { $json .= shift },
	    errfunc => sub { warn "$_[0]\n" }
	);
    };
    warn $@ if $@;

    my $info = eval { decode_json($json) };
    if (my $err = $@) {
	warn "could not parse qemu-img info command output for '$filename' - $err\n";
	return wantarray ? (undef, undef, undef, undef, $st->ctime) : undef;
    }

    my ($size, $format, $used, $parent) = $info->@{qw(virtual-size format actual-size backing-filename)};

    ($size) = ($size =~ /^(\d+)$/) or die "size '$size' not an integer\n"; # untaint
    # coerce back from string
    $size = int($size);
    ($used) = ($used =~ /^(\d+)$/) or die "used '$used' not an integer\n"; # untaint
    # coerce back from string
    $used = int($used);
    ($format) = ($format =~ /^(\S+)$/) or die "format '$format' includes whitespace\n"; # untaint
    if (defined($parent)) {
	($parent) = ($parent =~ /^(\S+)$/) or die "parent '$parent' includes whitespace\n"; # untaint
    }
    return wantarray ? ($size, $format, $used, $parent, $st->ctime) : $size;
}

# FIXME remove on the next APIAGE reset.
# Deprecated, use get_volume_attribute instead.
sub get_volume_notes {
    my ($class, $scfg, $storeid, $volname, $timeout) = @_;

    die "volume notes are not supported for $class";
}

# FIXME remove on the next APIAGE reset.
# Deprecated, use update_volume_attribute instead.
sub update_volume_notes {
    my ($class, $scfg, $storeid, $volname, $notes, $timeout) = @_;

    die "volume notes are not supported for $class";
}

# Returns undef if the attribute is not supported for the volume.
# Should die if there is an error fetching the attribute.
# Possible attributes:
# notes     - user-provided comments/notes.
# protected - not to be removed by free_image, and for backups, ignored when pruning.
sub get_volume_attribute {
    my ($class, $scfg, $storeid, $volname, $attribute) = @_;

    if ($attribute eq 'notes') {
	 my $notes = eval { $class->get_volume_notes($scfg, $storeid, $volname); };
	 if (my $err = $@) {
	     return if $err =~ m/^volume notes are not supported/;
	     die $err;
	 }
	 return $notes;
    }

    return;
}

# Dies if the attribute is not supported for the volume.
sub update_volume_attribute {
    my ($class, $scfg, $storeid, $volname, $attribute, $value) = @_;

    if ($attribute eq 'notes') {
	$class->update_volume_notes($scfg, $storeid, $volname, $value);
    }

    die "attribute '$attribute' is not supported for storage type '$scfg->{type}'\n";
}

sub volume_size_info {
    my ($class, $scfg, $storeid, $volname, $timeout) = @_;
    my $path = $class->filesystem_path($scfg, $volname);
    return file_size_info($path, $timeout);

}

sub volume_resize {
    my ($class, $scfg, $storeid, $volname, $size, $running) = @_;

    die "can't resize this image format\n" if $volname !~ m/\.(raw|qcow2)$/;

    return 1 if $running;

    my $path = $class->filesystem_path($scfg, $volname);

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

    my $cmd = ['/usr/bin/qemu-img', 'resize', '-f', $format, $path , $size];

    run_command($cmd, timeout => 10);

    return undef;
}

sub volume_snapshot {
    my ($class, $scfg, $storeid, $volname, $snap) = @_;

    die "can't snapshot this image format\n" if $volname !~ m/\.(qcow2|qed)$/;

    my $path = $class->filesystem_path($scfg, $volname);

    my $cmd = ['/usr/bin/qemu-img', 'snapshot','-c', $snap, $path];

    run_command($cmd);

    return undef;
}

# Asserts that a rollback to $snap on $volname is possible.
# If certain snapshots are preventing the rollback and $blockers is an array
# reference, the snapshot names can be pushed onto $blockers prior to dying.
sub volume_rollback_is_possible {
    my ($class, $scfg, $storeid, $volname, $snap, $blockers) = @_;

    return 1;
}

sub volume_snapshot_rollback {
    my ($class, $scfg, $storeid, $volname, $snap) = @_;

    die "can't rollback snapshot this image format\n" if $volname !~ m/\.(qcow2|qed)$/;

    my $path = $class->filesystem_path($scfg, $volname);

    my $cmd = ['/usr/bin/qemu-img', 'snapshot','-a', $snap, $path];

    run_command($cmd);

    return undef;
}

sub volume_snapshot_delete {
    my ($class, $scfg, $storeid, $volname, $snap, $running) = @_;

    die "can't delete snapshot for this image format\n" if $volname !~ m/\.(qcow2|qed)$/;

    return 1 if $running;

    my $path = $class->filesystem_path($scfg, $volname);

    $class->deactivate_volume($storeid, $scfg, $volname, $snap, {});

    my $cmd = ['/usr/bin/qemu-img', 'snapshot','-d', $snap, $path];

    run_command($cmd);

    return undef;
}

sub volume_snapshot_needs_fsfreeze {

    return 0;
}
sub storage_can_replicate {
    my ($class, $scfg, $storeid, $format) = @_;

    return 0;
}

sub volume_has_feature {
    my ($class, $scfg, $feature, $storeid, $volname, $snapname, $running, $opts) = @_;

    my $features = {
	snapshot => {
	    current => { qcow2 => 1 },
	    snap => { qcow2 => 1 },
	},
	clone => {
	    base => { qcow2 => 1, raw => 1, vmdk => 1 },
	},
	template => {
	    current => { qcow2 => 1, raw => 1, vmdk => 1, subvol => 1 },
	},
	copy => {
	    base => { qcow2 => 1, raw => 1, vmdk => 1 },
	    current => { qcow2 => 1, raw => 1, vmdk => 1 },
	    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},
	},
    };

    if ($feature eq 'clone') {
	if (
	    defined($opts->{valid_target_formats})
	    && !(grep { $_ eq 'qcow2' } @{$opts->{valid_target_formats}})
	) {
	    return 0; # clone_image creates a qcow2 volume
	}
    } elsif ($feature eq 'rename') {
	return 0 if $class->can('api') && $class->api() < 10;
    }


    my ($vtype, $name, $vmid, $basename, $basevmid, $isBase, $format) = $class->parse_volname($volname);

    my $key = undef;
    if($snapname){
	$key = 'snap';
    }else{
	$key =  $isBase ? 'base' : 'current';
    }

    return 1 if defined($features->{$feature}->{$key}->{$format});

    return undef;
}

sub list_images {
    my ($class, $storeid, $scfg, $vmid, $vollist, $cache) = @_;

    my $imagedir = $class->get_subdir($scfg, 'images');

    my ($defFmt, $vaidFmts) = default_format($scfg);
    my $fmts = join ('|', @$vaidFmts);

    my $res = [];

    foreach my $fn (<$imagedir/[0-9][0-9]*/*>) {

	next if $fn !~ m!^(/.+/(\d+)/([^/]+\.($fmts)))$!;
	$fn = $1; # untaint

	my $owner = $2;
	my $name = $3;

	next if !$vollist && defined($vmid) && ($owner ne $vmid);

	my ($size, $format, $used, $parent, $ctime) = file_size_info($fn);
	next if !($format && defined($size));

	my $volid;
	if ($parent && $parent =~ m!^../(\d+)/([^/]+\.($fmts))$!) {
	    my ($basevmid, $basename) = ($1, $2);
	    $volid = "$storeid:$basevmid/$basename/$owner/$name";
	} else {
	    $volid = "$storeid:$owner/$name";
	}

	if ($vollist) {
	    my $found = grep { $_ eq $volid } @$vollist;
	    next if !$found;
	}

	my $info = {
	    volid => $volid, format => $format,
	    size => $size, vmid => $owner, used => $used, parent => $parent
	};

	$info->{ctime} = $ctime if $ctime;

	push @$res, $info;
    }

    return $res;
}

# list templates ($tt = <iso|vztmpl|backup|snippets>)
my $get_subdir_files = sub {
    my ($sid, $path, $tt, $vmid) = @_;

    my $res = [];

    foreach my $fn (<$path/*>) {
	my $st = File::stat::stat($fn);

	next if (!$st || S_ISDIR($st->mode));

	my $info;

	if ($tt eq 'iso') {
	    next if $fn !~ m!/([^/]+$PVE::Storage::ISO_EXT_RE_0)$!i;

	    $info = { volid => "$sid:iso/$1", format => 'iso' };

	} elsif ($tt eq 'vztmpl') {
	    next if $fn !~ m!/([^/]+$PVE::Storage::VZTMPL_EXT_RE_1)$!;

	    $info = { volid => "$sid:vztmpl/$1", format => "t$2" };

	} elsif ($tt eq 'backup') {
	    next if $fn !~ m!/([^/]+$PVE::Storage::BACKUP_EXT_RE_2)$!;
	    my $original = $fn;
	    my $format = $2;
	    $fn = $1;

	    # only match for VMID now, to avoid false positives (VMID in parent directory name)
	    next if defined($vmid) && $fn !~ m/\S+-$vmid-\S+/;

	    $info = { volid => "$sid:backup/$fn", format => $format };

	    my $archive_info = eval { PVE::Storage::archive_info($fn) } // {};

	    $info->{ctime} = $archive_info->{ctime} if defined($archive_info->{ctime});
	    $info->{subtype} = $archive_info->{type} // 'unknown';

	    if (defined($vmid) || $fn =~ m!\-([1-9][0-9]{2,8})\-[^/]+\.${format}$!) {
		$info->{vmid} = $vmid // $1;
	    }

	    my $notes_fn = $original.NOTES_EXT;
	    if (-f $notes_fn) {
		my $notes = PVE::Tools::file_read_firstline($notes_fn);
		$info->{notes} = eval { decode('UTF-8', $notes, 1) } // $notes if defined($notes);
	    }

	    $info->{protected} = 1 if -e PVE::Storage::protection_file_path($original);
	} elsif ($tt eq 'snippets') {

	    $info = {
		volid => "$sid:snippets/". basename($fn),
		format => 'snippet',
	    };
	}

	$info->{size} = $st->size;
	$info->{ctime} //= $st->ctime;

	push @$res, $info;
    }

    return $res;
};

# If attributes are set on a volume, they should be included in the result.
# See get_volume_attribute for a list of possible attributes.
sub list_volumes {
    my ($class, $storeid, $scfg, $vmid, $content_types) = @_;

    my $res = [];
    my $vmlist = PVE::Cluster::get_vmlist();
    foreach my $type (@$content_types) {
	my $data;

	if ($type eq 'images' || $type eq 'rootdir') {
	    $data = $class->list_images($storeid, $scfg, $vmid);
	} elsif ($scfg->{path}) {
	    my $path = $class->get_subdir($scfg, $type);

	    if ($type eq 'iso' && !defined($vmid)) {
		$data = $get_subdir_files->($storeid, $path, 'iso');
	    } elsif ($type eq 'vztmpl'&& !defined($vmid)) {
		$data = $get_subdir_files->($storeid, $path, 'vztmpl');
	    } elsif ($type eq 'backup') {
		$data = $get_subdir_files->($storeid, $path, 'backup', $vmid);
	    } elsif ($type eq 'snippets') {
		$data = $get_subdir_files->($storeid, $path, 'snippets');
	    }
	}

	next if !$data;

	foreach my $item (@$data) {
	    if ($type eq 'images' || $type eq 'rootdir') {
		my $vminfo = $vmlist->{ids}->{$item->{vmid}};
		my $vmtype;
		if (defined($vminfo)) {
		    $vmtype = $vminfo->{type};
		}
		if (defined($vmtype) && $vmtype eq 'lxc') {
		    $item->{content} = 'rootdir';
		} else {
		    $item->{content} = 'images';
		}
		next if $type ne $item->{content};
	    } else {
		$item->{content} = $type;
	    }

	    push @$res, $item;
	}
    }

    return $res;
}

sub status {
    my ($class, $storeid, $scfg, $cache) = @_;

    my $path = $scfg->{path};

    die "storage definition has no path\n" if !$path;

    my $timeout = 2;
    my $res = PVE::Tools::df($path, $timeout);

    return undef if !$res || !$res->{total};

    return ($res->{total}, $res->{avail}, $res->{used}, 1);
}

# Returns a hash with the snapshot names as keys and the following data:
# id        - Unique id to distinguish different snapshots even if the have the same name.
# timestamp - Creation time of the snapshot (seconds since epoch).
# Returns an empty hash if the volume does not exist.
sub volume_snapshot_info {
    my ($class, $scfg, $storeid, $volname) = @_;

    die "volume_snapshot_info is not implemented for $class";
}

sub activate_storage {
    my ($class, $storeid, $scfg, $cache) = @_;

    my $path = $scfg->{path};

    die "storage definition has no path\n" if !$path;

    # this path test may hang indefinitely on unresponsive mounts
    my $timeout = 2;
    if (! PVE::Tools::run_fork_with_timeout($timeout, sub {-d $path})) {
	die "unable to activate storage '$storeid' - " .
	"directory '$path' does not exist or is unreachable\n";
    }

    # TODO: mkdir is basically deprecated since 8.0, but we don't warn here until 8.4 or 9.0, as we
    # only got the replacement in 8.0, so no real replacement window, and its really noisy.

    if (defined($scfg->{content})) {
	# (opt-out) create content dirs and check validity
	if (
	    (!defined($scfg->{'create-subdirs'}) || $scfg->{'create-subdirs'})
	    # FIXME The mkdir option is deprecated. Remove with PVE 9?
	    && (!defined($scfg->{mkdir}) || $scfg->{mkdir})
	) {
	    for my $vtype (sort keys %$vtype_subdirs) {
		# OpenVZMigrate uses backup (dump) dir
		if (
		    defined($scfg->{content}->{$vtype})
		    || ($vtype eq 'backup' && defined($scfg->{content}->{'rootdir'}))
		) {
		    my $subdir = $class->get_subdir($scfg, $vtype);
		    mkpath $subdir if $subdir ne $path;
		}
	    }
	}

	# check that content dirs are pairwise inequal
	my $resolved_subdirs = {};
	for my $vtype (sort keys $scfg->{content}->%*) {
	    my $subdir = $class->get_subdir($scfg, $vtype);
	    my $abs_subdir = abs_path($subdir);
	    next if !defined($abs_subdir);

	    die "storage '$storeid' uses directory $abs_subdir for multiple content types\n"
		if defined($abs_subdir) && defined($resolved_subdirs->{$abs_subdir});

	    $resolved_subdirs->{$abs_subdir} = 1;
	}
    }
}

sub deactivate_storage {
    my ($class, $storeid, $scfg, $cache) = @_;

    # do nothing by default
}

sub map_volume {
    my ($class, $storeid, $scfg, $volname, $snapname) = @_;

    my ($path) = $class->path($scfg, $volname, $storeid, $snapname);
    return $path;
}

sub unmap_volume {
    my ($class, $storeid, $scfg, $volname, $snapname) = @_;

    return 1;
}

sub activate_volume {
    my ($class, $storeid, $scfg, $volname, $snapname, $cache) = @_;

    my $path = $class->filesystem_path($scfg, $volname, $snapname);

    # check is volume exists
    if ($scfg->{path}) {
	die "volume '$storeid:$volname' does not exist\n" if ! -e $path;
    } else {
	die "volume '$storeid:$volname' does not exist\n" if ! -b $path;
    }
}

sub deactivate_volume {
    my ($class, $storeid, $scfg, $volname, $snapname, $cache) = @_;

    # do nothing by default
}

sub check_connection {
    my ($class, $storeid, $scfg) = @_;
    # do nothing by default
    return 1;
}

sub prune_backups {
    my ($class, $scfg, $storeid, $keep, $vmid, $type, $dryrun, $logfunc) = @_;

    $logfunc //= sub { print "$_[1]\n" };

    my $backups = $class->list_volumes($storeid, $scfg, $vmid, ['backup']);

    my $backup_groups = {};
    my $prune_list = [];

    foreach my $backup (@{$backups}) {
	my $volid = $backup->{volid};
	my $archive_info = eval { PVE::Storage::archive_info($volid) } // {};
	my $backup_type = $archive_info->{type} // 'unknown';
	my $backup_vmid = $archive_info->{vmid} // $backup->{vmid};

	next if defined($type) && $type ne $backup_type;

	my $prune_entry = {
	    ctime => $backup->{ctime},
	    type => $backup_type,
	    volid => $volid,
	};

	$prune_entry->{vmid} = $backup_vmid if defined($backup_vmid);

	if ($archive_info->{is_std_name}) {
	    die "internal error - got no VMID\n" if !defined($backup_vmid);
	    die "internal error - got wrong VMID '$backup_vmid' != '$vmid'\n"
		if defined($vmid) && $backup_vmid ne $vmid;

	    $prune_entry->{ctime} = $archive_info->{ctime};
	    my $group = "$backup_type/$backup_vmid";
	    push @{$backup_groups->{$group}}, $prune_entry;
	} else {
	    # ignore backups that don't use the standard naming scheme
	    $prune_entry->{mark} = 'renamed';
	}

	$prune_entry->{mark} = 'protected' if $backup->{protected};

	push @{$prune_list}, $prune_entry;
    }

    foreach my $backup_group (values %{$backup_groups}) {
	PVE::Storage::prune_mark_backup_group($backup_group, $keep);
    }

    my $failed;
    if (!$dryrun) {
	foreach my $prune_entry (@{$prune_list}) {
	    next if $prune_entry->{mark} ne 'remove';

	    my $volid = $prune_entry->{volid};
	    $logfunc->('info', "removing backup '$volid'");
	    eval {
		my (undef, $volname) = parse_volume_id($volid);
		my $archive_path = $class->filesystem_path($scfg, $volname);
		PVE::Storage::archive_remove($archive_path);
	    };
	    if (my $err = $@) {
		$logfunc->('err', "error when removing backup '$volid' - $err\n");
		$failed = 1;
	    }
	}
    }
    die "error pruning backups - check log\n" if $failed;

    return $prune_list;
}

# Import/Export interface:
#   Any path based storage is assumed to support 'raw' and 'tar' streams, so
#   the default implementations will return this if $scfg->{path} is set,
#   mimicking the old PVE::Storage::storage_migrate() function.
#
# Plugins may fall back to PVE::Storage::Plugin::volume_{export,import}...
#   functions in case the format doesn't match their specialized
#   implementations to reuse the raw/tar code.
#
# Format specification:
#   The following formats are all prefixed with image information in the form
#   of a 64 bit little endian unsigned integer (pack('Q<')) in order to be able
#   to preallocate the image on storages which require it.
#
#   raw+size: (image files only)
#     A raw binary data stream such as produced via `dd if=TheImageFile`.
#   qcow2+size, vmdk: (image files only)
#     A raw qcow2/vmdk/... file such as produced via `dd if=some.qcow2` for
#     files which are already in qcow2 format, or via `qemu-img convert`.
#     Note that these formats are only valid with $with_snapshots being true.
#   tar+size: (subvolumes only)
#     A GNU tar stream containing just the inner contents of the subvolume.
#     This does not distinguish between the contents of a privileged or
#     unprivileged container. In other words, this is from the root user
#     namespace's point of view with no uid-mapping in effect.
#     As produced via `tar -C vm-100-disk-1.subvol -cpf TheOutputFile.dat .`

# Plugins may reuse these helpers. Changes to the header format should be
# reflected by changes to the function prototypes.
sub write_common_header($$) {
    my ($fh, $image_size_in_bytes) = @_;
    syswrite($fh, pack("Q<", $image_size_in_bytes), 8);
}

sub read_common_header($) {
    my ($fh) = @_;
    sysread($fh, my $size, 8);
    $size = unpack('Q<', $size);
    die "import: no size found in export header, aborting.\n" if !defined($size);
    # Size is in bytes!
    return $size;
}

# Export a volume into a file handle as a stream of desired format.
sub volume_export {
    my ($class, $scfg, $storeid, $fh, $volname, $format, $snapshot, $base_snapshot, $with_snapshots) = @_;
    if ($scfg->{path} && !defined($snapshot) && !defined($base_snapshot)) {
	my $file = $class->path($scfg, $volname, $storeid)
	    or goto unsupported;
	my ($size, $file_format) = file_size_info($file);

	if ($format eq 'raw+size') {
	    goto unsupported if $with_snapshots || $file_format eq 'subvol';
	    write_common_header($fh, $size);
	    if ($file_format eq 'raw') {
		run_command(['dd', "if=$file", "bs=4k"], output => '>&'.fileno($fh));
	    } else {
		run_command(['qemu-img', 'convert', '-f', $file_format, '-O', 'raw', $file, '/dev/stdout'],
		            output => '>&'.fileno($fh));
	    }
	    return;
	} elsif ($format =~ /^(qcow2|vmdk)\+size$/) {
	    my $data_format = $1;
	    goto unsupported if !$with_snapshots || $file_format ne $data_format;
	    write_common_header($fh, $size);
	    run_command(['dd', "if=$file", "bs=4k"], output => '>&'.fileno($fh));
	    return;
	} elsif ($format eq 'tar+size') {
	    goto unsupported if $file_format ne 'subvol';
	    write_common_header($fh, $size);
	    run_command(['tar', @COMMON_TAR_FLAGS, '-cf', '-', '-C', $file, '.'],
	                output => '>&'.fileno($fh));
	    return;
	}
    }
 unsupported:
    die "volume export format $format not available for $class";
}

sub volume_export_formats {
    my ($class, $scfg, $storeid, $volname, $snapshot, $base_snapshot, $with_snapshots) = @_;
    if ($scfg->{path} && !defined($snapshot) && !defined($base_snapshot)) {
	my $file = $class->path($scfg, $volname, $storeid)
	    or return;
	my ($size, $format) = file_size_info($file);

	if ($with_snapshots) {
	    return ($format.'+size') if ($format eq 'qcow2' || $format eq 'vmdk');
	    return ();
	}
	return ('tar+size') if $format eq 'subvol';
	return ('raw+size');
    }
    return ();
}

# Import data from a stream, creating a new or replacing or adding to an existing volume.
sub volume_import {
    my ($class, $scfg, $storeid, $fh, $volname, $format, $snapshot, $base_snapshot, $with_snapshots, $allow_rename) = @_;

    die "volume import format '$format' not available for $class\n"
	if $format !~ /^(raw|tar|qcow2|vmdk)\+size$/;
    my $data_format = $1;

    die "format $format cannot be imported without snapshots\n"
	if !$with_snapshots && ($data_format eq 'qcow2' || $data_format eq 'vmdk');
    die "format $format cannot be imported with snapshots\n"
	if $with_snapshots && ($data_format eq 'raw' || $data_format eq 'tar');

    my ($vtype, $name, $vmid, $basename, $basevmid, $isBase, $file_format) =
	$class->parse_volname($volname);

    # XXX: Should we bother with conversion routines at this level? This won't
    # happen without manual CLI usage, so for now we just error out...
    die "cannot import format $format into a file of format $file_format\n"
	if $data_format ne $file_format && !($data_format eq 'tar' && $file_format eq 'subvol');

    # Check for an existing file first since interrupting alloc_image doesn't
    # free it.
    my $file = $class->path($scfg, $volname, $storeid);
    if (-e $file) {
	die "file '$file' already exists\n" if !$allow_rename;
	warn "file '$file' already exists - importing with a different name\n";
	$name = undef;
    }

    my ($size) = read_common_header($fh);
    $size = int($size/1024);

    eval {
	my $allocname = $class->alloc_image($storeid, $scfg, $vmid, $file_format, $name, $size);
	my $oldname = $volname;
	$volname = $allocname;
	if (defined($name) && $allocname ne $oldname) {
	    die "internal error: unexpected allocated name: '$allocname' != '$oldname'\n";
	}
	my $file = $class->path($scfg, $volname, $storeid)
	    or die "internal error: failed to get path to newly allocated volume $volname\n";
	if ($data_format eq 'raw' || $data_format eq 'qcow2' || $data_format eq 'vmdk') {
	    run_command(['dd', "of=$file", 'conv=sparse', 'bs=64k'],
	                input => '<&'.fileno($fh));
	} elsif ($data_format eq 'tar') {
	    run_command(['tar', @COMMON_TAR_FLAGS, '-C', $file, '-xf', '-'],
	                input => '<&'.fileno($fh));
	} else {
	    die "volume import format '$format' not available for $class";
	}
    };
    if (my $err = $@) {
	eval { $class->free_image($storeid, $scfg, $volname, 0, $file_format) };
	warn $@ if $@;
	die $err;
    }

    return "$storeid:$volname";
}

sub volume_import_formats {
    my ($class, $scfg, $storeid, $volname, $snapshot, $base_snapshot, $with_snapshots) = @_;
    if ($scfg->{path} && !defined($base_snapshot)) {
	my $format = ($class->parse_volname($volname))[6];
	if ($with_snapshots) {
	    return ($format.'+size') if ($format eq 'qcow2' || $format eq 'vmdk');
	    return ();
	}
	return ('tar+size') if $format eq 'subvol';
	return ('raw+size');
    }
    return ();
}

sub rename_volume {
    my ($class, $scfg, $storeid, $source_volname, $target_vmid, $target_volname) = @_;
    die "not implemented in storage plugin '$class'\n" if $class->can('api') && $class->api() < 10;
    die "no path found\n" if !$scfg->{path};

    my (
	undef,
	$source_image,
	$source_vmid,
	$base_name,
	$base_vmid,
	undef,
	$format
    ) = $class->parse_volname($source_volname);

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

    my $basedir = $class->get_subdir($scfg, 'images');

    mkpath "${basedir}/${target_vmid}";

    my $old_path = "${basedir}/${source_vmid}/${source_image}";
    my $new_path = "${basedir}/${target_vmid}/${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}";
}

sub config_aware_base_mkdir {
    my ($class, $scfg, $path) = @_;

    # FIXME the mkdir parameter is deprecated and create-base-path should be used
    if ($scfg->{'create-base-path'} // $scfg->{mkdir} // 1) {
	mkpath($path);
    }
}

1;