[PATCH v2 pve-storage 2/2] add lvmqcow2 plugin: (lvm with external qcow2 snapshot)

Alexandre Derumier alexandre.derumier at groupe-cyllene.com
Mon Sep 30 13:31:53 CEST 2024


Signed-off-by: Alexandre Derumier <alexandre.derumier at groupe-cyllene.com>
---
 src/PVE/Storage.pm                |   2 +
 src/PVE/Storage/LvmQcow2Plugin.pm | 460 ++++++++++++++++++++++++++++++
 src/PVE/Storage/Makefile          |   3 +-
 3 files changed, 464 insertions(+), 1 deletion(-)
 create mode 100644 src/PVE/Storage/LvmQcow2Plugin.pm

diff --git a/src/PVE/Storage.pm b/src/PVE/Storage.pm
index 57b2038..119998f 100755
--- a/src/PVE/Storage.pm
+++ b/src/PVE/Storage.pm
@@ -28,6 +28,7 @@ use PVE::Storage::Plugin;
 use PVE::Storage::DirPlugin;
 use PVE::Storage::LVMPlugin;
 use PVE::Storage::LvmThinPlugin;
+use PVE::Storage::LvmQcow2Plugin;
 use PVE::Storage::NFSPlugin;
 use PVE::Storage::CIFSPlugin;
 use PVE::Storage::ISCSIPlugin;
@@ -54,6 +55,7 @@ our $KNOWN_EXPORT_FORMATS = ['raw+size', 'tar+size', 'qcow2+size', 'vmdk+size',
 PVE::Storage::DirPlugin->register();
 PVE::Storage::LVMPlugin->register();
 PVE::Storage::LvmThinPlugin->register();
+PVE::Storage::LvmQcow2Plugin->register();
 PVE::Storage::NFSPlugin->register();
 PVE::Storage::CIFSPlugin->register();
 PVE::Storage::ISCSIPlugin->register();
diff --git a/src/PVE/Storage/LvmQcow2Plugin.pm b/src/PVE/Storage/LvmQcow2Plugin.pm
new file mode 100644
index 0000000..68c8686
--- /dev/null
+++ b/src/PVE/Storage/LvmQcow2Plugin.pm
@@ -0,0 +1,460 @@
+package PVE::Storage::LvmQcow2Plugin;
+
+use strict;
+use warnings;
+
+use IO::File;
+
+use PVE::Tools qw(run_command trim);
+use PVE::Storage::Plugin;
+use PVE::Storage::LVMPlugin;
+use PVE::JSONSchema qw(get_standard_option);
+
+use base qw(PVE::Storage::LVMPlugin);
+
+# Configuration
+
+sub type {
+    return 'lvmqcow2';
+}
+
+sub plugindata {
+    return {
+	#container not yet implemented #need to implemented dm-qcow2
+	content => [ {images => 1, rootdir => 1}, { images => 1 }],
+    };
+}
+
+sub properties {
+    return {
+    };
+}
+
+sub options {
+    return {
+	vgname => { fixed => 1 },
+	nodes => { optional => 1 },
+	shared => { optional => 1 },
+	disable => { optional => 1 },
+	saferemove => { optional => 1 },
+	saferemove_throughput => { optional => 1 },
+	content => { optional => 1 },
+	base => { fixed => 1, optional => 1 },
+	tagged_only => { optional => 1 },
+	bwlimit => { optional => 1 },
+	snapext => { fixed => 1 },
+    };
+}
+
+# Storage implementation
+
+sub parse_volname {
+    my ($class, $volname) = @_;
+
+    PVE::Storage::Plugin::parse_lvm_name($volname);
+    my $format = $volname =~ m/^(.*)-snap-/ ? 'qcow2' : 'raw';
+
+    if ($volname =~ m/^((vm|base)-(\d+)-\S+)$/) {
+        return ('images', $1, $3, undef, undef, $2 eq 'base', $format);
+    }
+
+    die "unable to parse lvm volume name '$volname'\n";
+}
+
+sub filesystem_path {
+    my ($class, $scfg, $volname, $snapname, $current_snap) = @_;
+
+    my ($vtype, $name, $vmid) = $class->parse_volname($volname);
+
+    my $vg = $scfg->{vgname};
+
+    my $path = "/dev/$vg/$name";
+
+    if($snapname) {
+	$path = get_snap_volname($path, $snapname);
+    } elsif ($current_snap) {
+	$path = $current_snap->{file};
+    }
+
+    return wantarray ? ($path, $vmid, $vtype) : $path;
+}
+
+sub create_base {
+    my ($class, $storeid, $scfg, $volname) = @_;
+
+    my $vg = $scfg->{vgname};
+
+    my ($vtype, $name, $vmid, $basename, $basevmid, $isBase) =
+        $class->parse_volname($volname);
+
+    die "create_base not possible with base image\n" if $isBase;
+
+    die "unable to create base volume - found snapshot" if $class->snapshot_exist($scfg, $storeid, $volname);
+
+    my $newname = $name;
+    $newname =~ s/^vm-/base-/;
+
+    my $cmd = ['/sbin/lvrename', $vg, $volname, $newname];
+    run_command($cmd, errmsg => "lvrename '$vg/$volname' => '$vg/$newname' error");
+
+    # set inactive, read-only flags
+    $cmd = ['/sbin/lvchange', '-an', '-pr', "$vg/$newname"];
+    eval { run_command($cmd); };
+    warn $@ if $@;
+
+    my $newvolname = $newname;
+
+    return $newvolname;
+}
+
+sub clone_image {
+    my ($class, $scfg, $storeid, $volname, $vmid, $snap) = @_;
+
+    die "can't clone images in lvm storage\n";
+}
+
+sub alloc_image {
+    my ($class, $storeid, $scfg, $vmid, $fmt, $name, $size) = @_;
+
+    die "unsupported format '$fmt'" if $fmt ne 'raw';
+
+    die "illegal name '$name' - should be 'vm-$vmid-*'\n"
+	if  $name && $name !~ m/^vm-$vmid-/;
+
+    my $vgs = PVE::Storage::LVMPlugin::lvm_vgs();
+
+    my $vg = $scfg->{vgname};
+
+    die "no such volume group '$vg'\n" if !defined ($vgs->{$vg});
+
+    my $free = int($vgs->{$vg}->{free});
+
+    die "not enough free space ($free < $size)\n" if $free < $size;
+
+    $name = $class->find_free_diskname($storeid, $scfg, $vmid)
+	if !$name;
+
+    my $tags = ["pve-vm-$vmid"];
+    if ($name =~ m/^(((vm|base)-(\d+)-disk-(\d+)))(-snap-(.*))?/) {
+        push @$tags, "\@pve-$1";
+    }
+
+    PVE::Storage::LVMPlugin::lvcreate($vg, $name, $size, $tags);
+
+    return $name;
+}
+
+sub volume_snapshot_info {
+    my ($class, $scfg, $storeid, $volname) = @_;
+
+    return $class->list_snapshots($scfg, $storeid, $volname);
+}
+
+sub activate_volume {
+    my ($class, $storeid, $scfg, $volname, $snapname, $cache) = @_;
+
+    my $lvm_activate_mode = 'ey';
+    my $tag = undef;
+
+    #activate volume && all volumes snapshots by tag
+    if($volname =~ m/^(((vm|base)-(\d+)-disk-(\d+)))(-snap-(.*))?/) {
+	$tag = "\@pve-vm-$4-disk-$5";
+    }
+
+    my $cmd = ['/sbin/lvchange', "-a$lvm_activate_mode", $tag];
+    run_command($cmd, errmsg => "can't activate LV '$tag'");
+
+    $cmd = ['/sbin/lvchange', '--refresh', $tag];
+    run_command($cmd, errmsg => "can't refresh LV '$tag' for activation");
+}
+
+sub deactivate_volume {
+    my ($class, $storeid, $scfg, $volname, $snapname, $cache) = @_;
+
+    my $tag = undef;
+    #deactivate volume && all volumes snasphots by tag
+    if($volname =~ m/^(((vm|base)-(\d+)-disk-(\d+)))(-snap-(.*))?/) {
+	$tag = "\@pve-vm-$4-disk-$5";
+    }
+
+    my $cmd = ['/sbin/lvchange', '-aln', $tag];
+    run_command($cmd, errmsg => "can't deactivate LV '$tag'");
+}
+
+sub volume_resize {
+    my ($class, $scfg, $storeid, $volname, $size, $running) = @_;
+
+    #we should resize the base image and parents snapshots,
+    #but how to manage rollback ?
+
+    die "can't resize if snasphots exist" if $class->snapshot_exist($scfg, $storeid, $volname);
+
+    return 1;
+}
+
+sub volume_snapshot {
+    my ($class, $scfg, $storeid, $volname, $snap) = @_;
+
+    $class->activate_volume($storeid, $scfg, $volname, undef, {});
+
+    my $current_path = $class->path($scfg, $volname, $storeid);
+    my $current_format = (PVE::Storage::Plugin::file_size_info($current_path))[1];
+    my $snappath = get_snap_volname($current_path, $snap);
+
+    my $snapvolname = get_snap_volname($volname, $snap);
+    #allocate lvm snapshot volume
+    my ($vtype, $name, $vmid, $basename, $basevmid, $isBase) =
+	$class->parse_volname($volname);
+    my $size = $class->volume_size_info($scfg, $storeid, $volname, 5);
+    #add 100M for qcow2 headers
+    $size = int($size/1024) + (100*1024);
+
+    $class->alloc_image($storeid, $scfg, $vmid, 'raw', $snapvolname, $size);
+
+    # create the qcow2 fs
+    eval {
+        my $cmd = ['/usr/bin/qemu-img', 'create', '-b', $current_path,
+                   '-F', $current_format, '-f', 'qcow2', $snappath];
+        my $options = "extended_l2=on,";
+        $options .= PVE::Storage::Plugin::preallocation_cmd_option($scfg, 'qcow2');
+        push @$cmd, '-o', $options;
+        run_command($cmd);
+    };
+    if ($@) {
+	eval { $class->free_image($storeid, $scfg, $snapvolname, 0) };
+	warn $@ if $@;
+    }
+}
+
+# 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) = @_;
+
+    my $path = $class->filesystem_path($scfg, $volname);
+    my $snappath = get_snap_volname($path, $snap);
+    my $currentpath = $class->path($scfg, $volname, $storeid);
+    return 1 if $currentpath eq $snappath;
+
+    die "can't rollback, '$snap' is not most recent snapshot on '$volname'\n";
+
+    return 1;
+}
+
+sub volume_snapshot_rollback {
+    my ($class, $scfg, $storeid, $volname, $snap) = @_;
+
+    $class->activate_volume($storeid, $scfg, $volname, undef, {});
+    #simply delete the current snapshot and recreate it
+
+    my $snapvolname = get_snap_volname($volname, $snap);
+
+    $class->free_image($storeid, $scfg, $snapvolname, 0);
+    $class->volume_snapshot($scfg, $storeid, $volname, $snap);
+}
+
+sub volume_snapshot_delete {
+    my ($class, $scfg, $storeid, $volname, $snap, $running) = @_;
+
+    return 1 if $running;
+
+    $class->activate_volume($storeid, $scfg, $volname, undef, {});
+
+    my $snapshots = $class->volume_snapshot_info($scfg, $storeid, $volname);
+    my $snappath = $snapshots->{$snap}->{file};
+    if(!$snappath) {
+	warn "$snap already deleted. skip\n";
+	return;
+    }
+
+    my $snapvolname = $snapshots->{$snap}->{volname};
+    my $parentsnap = $snapshots->{$snap}->{parent};
+    my $childsnap = $snapshots->{$snap}->{child};
+    die "error: can't find a parent for this snapshot" if !$parentsnap;
+
+    my $parentpath = $snapshots->{$parentsnap}->{file};
+    my $parentformat = $snapshots->{$parentsnap}->{'format'} if $parentsnap;
+    my $childpath = $snapshots->{$childsnap}->{file} if $childsnap;
+    my $childformat = $snapshots->{$childsnap}->{'format'} if $childsnap;
+
+    print "merge snapshot $snap to $parentsnap\n";
+    my $cmd = ['/usr/bin/qemu-img', 'commit', $snappath];
+    run_command($cmd);
+
+    #if we delete an intermediate snapshot, we need to link upper snapshot to base snapshot
+    if($childpath && -e $childpath) {
+	die "missing parentsnap snapshot to rebase child $childpath\n" if !$parentpath;
+	print "link $childsnap to $parentsnap\n";
+	$cmd = ['/usr/bin/qemu-img', 'rebase', '-u', '-b', $parentpath, '-F', $parentformat, '-f', $childformat, $childpath];
+	run_command($cmd);
+    }
+
+    #delete the snapshot
+    $class->free_image($storeid, $scfg, $snapvolname, 0);
+ 
+    return;
+}
+
+sub volume_has_feature {
+    my ($class, $scfg, $feature, $storeid, $volname, $snapname, $running) = @_;
+
+    my $features = {
+	snapshot => { current => 1 },
+#	clone => { base => 1, snap => 1},   #don't allow to clone as we can't activate the base between different host ?
+	template => { current => 1},
+	copy => { base => 1, current => 1, snap => 1},
+	sparseinit => { base => 1, current => 1},
+	rename => {current => 1},
+    };
+
+    my ($vtype, $name, $vmid, $basename, $basevmid, $isBase) =
+	$class->parse_volname($volname);
+
+    my $key = undef;
+    if($snapname){
+	$key = 'snap';
+    }else{
+	$key =  $isBase ? 'base' : 'current';
+    }
+    return 1 if $features->{$feature}->{$key};
+
+    return undef;
+}
+
+sub get_snap_volname {
+    my ($path, $snap) = @_;
+
+    my $basepath = "";
+    my $baseformat = "";
+    if ($path =~ m/^((.*)((vm|base)-(\d+)-disk-(\d+)))(-snap-([a-zA-Z0-9]+))?(\.(raw|qcow2))?/) {
+        $basepath = $1;
+        $baseformat = $8;
+    }
+    my $snapvolname = $basepath."-snap-$snap.qcow2";
+    return $snapvolname;
+}
+
+sub get_snapname_from_path {
+    my ($path) = @_;
+
+    if ($path =~ m/^((.*)((vm|base)-(\d+)-disk-(\d+)))(-snap-([a-zA-Z0-9]+))?(\.(raw|qcow2))?/) {
+        my $snapname = $7;
+        return $snapname;
+    }
+    die "can't parse snapname from path $path";
+}
+
+sub get_current_snapshot {
+    my ($class, $scfg, $storeid, $volname) = @_;
+
+    #get more recent ctime volume
+    return $class->list_snapshots($scfg, $storeid, $volname, 1);
+}
+my $check_tags = sub {
+    my ($tags) = @_;
+
+    return defined($tags) && $tags =~ /(^|,)pve-vm-\d+(,|$)/;
+};
+
+sub list_images {
+    my ($class, $storeid, $scfg, $vmid, $vollist, $cache) = @_;
+
+    my $vgname = $scfg->{vgname};
+
+    $cache->{lvs} = PVE::Storage::LVMPlugin::lvm_list_volumes() if !$cache->{lvs};
+
+    my $res = [];
+
+    if (my $dat = $cache->{lvs}->{$vgname}) {
+
+	foreach my $volname (keys %$dat) {
+
+	    next if $volname !~ m/^(vm|base)-(\d+)-/;
+	    my $owner = $2;
+
+	    my $info = $dat->{$volname};
+
+	    next if $scfg->{tagged_only} && !&$check_tags($info->{tags});
+
+	    # Allow mirrored and RAID LVs
+	    next if $info->{lv_type} !~ m/^[-mMrR]$/;
+
+	    my $volid = "$storeid:$volname";
+
+	    if ($vollist) {
+		my $found = grep { $_ eq $volid } @$vollist;
+		next if !$found;
+	    } else {
+		next if defined($vmid) && ($owner ne $vmid);
+	    }
+
+	    push @$res, {
+		volid => $volid, format => 'raw', size => $info->{lv_size}, vmid => $owner,
+		ctime => $info->{ctime},
+	    };
+	}
+    }
+
+    return $res;
+}
+
+sub list_snapshots {
+    my ($class, $scfg, $storeid, $volname, $current_only) = @_;
+
+    my $vgname = $scfg->{vgname};
+
+    my $basevolname = $volname;
+    my $lvs = PVE::Storage::LVMPlugin::lvm_list_volumes($vgname);
+
+    my $vg = $lvs->{$vgname};
+
+    my ($vtype, $name, $vmid, $basename, $basevmid, $isBase, $format) = $class->parse_volname($volname);
+    my $snapshots = $class->list_images($storeid, $scfg, $vmid);
+
+    my $info = {};
+    for my $snap (@$snapshots) {
+	my $snap_volid = $snap->{volid};
+	next if ($snap_volid !~ m/$basevolname/);
+
+	my $snapname = get_snapname_from_path($snap_volid);
+	my (undef, $snap_volname) = PVE::Storage::parse_volume_id($snap_volid);
+	my $snapfile = $class->filesystem_path($scfg, $snap_volname, $snapname);
+	$snapname = 'base' if !$snapname;
+	$info->{$snapname}->{file} = $snapfile;
+	$info->{$snapname}->{volname} = $snap_volname;
+	$info->{$snapname}->{volid} = $snap_volid;
+	$info->{$snapname}->{ctime} = $snap->{ctime};
+
+	if (!$current_only) {
+	    my (undef, $format, undef, $parentfile, undef) = PVE::Storage::Plugin::file_size_info($snapfile);
+	    next if !$parentfile && $snapname ne 'base';   #bad unlinked snasphot
+
+	    my $parentname = get_snapname_from_path($parentfile) if $parentfile;
+	    $parentname = 'base' if !$parentname && $parentfile;
+
+	    $info->{$snapname}->{'format'} = $format;
+	    $info->{$snapname}->{parent} = $parentname if $parentname;
+	    $info->{$parentname}->{child} = $snapname if $parentname;
+	}
+    }
+
+    my @snapshots_sorted = sort { $info->{$b}{ctime} <=> $info->{$a}{ctime} } keys %$info;
+    my $current_snapname = $snapshots_sorted[0];
+    my $current_snapshot = $info->{$current_snapname};
+    return $current_snapshot if $current_only;
+
+    $info->{current} = { %$current_snapshot };
+    return $info;
+}
+
+sub snapshot_exist {
+    my ($class, $scfg, $storeid, $volname) = @_;
+
+    my $basepath = $class->filesystem_path($scfg, $volname);
+    my $currentpath = $class->path($scfg, $volname, $storeid);
+
+    die "can't resize if snasphots exist" if $currentpath ne $basepath;
+
+}
+1;
diff --git a/src/PVE/Storage/Makefile b/src/PVE/Storage/Makefile
index d5cc942..1af8aab 100644
--- a/src/PVE/Storage/Makefile
+++ b/src/PVE/Storage/Makefile
@@ -14,7 +14,8 @@ SOURCES= \
 	PBSPlugin.pm \
 	BTRFSPlugin.pm \
 	LvmThinPlugin.pm \
-	ESXiPlugin.pm
+	ESXiPlugin.pm \
+	LvmQcow2Plugin.pm
 
 .PHONY: install
 install:
-- 
2.39.2




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