[pve-devel] [PATCH] [FIX] Fix snapshot logic and enable lvmthin storage type.

[Gerrit Venema]

This enables the container to use the lvmthin storage type if one is set up.
It also fixes some logic in the handling of the freeze, errors on rollback
and the handling of the config sections to keep a correct tree of snapshots.

Signed-off-by: Gerrit Venema <gmoniker at gmail.com>
---
 src/PVE/LXC.pm | 54 +++++++++++++++++++++++++++---------------------------
 1 file changed, 27 insertions(+), 27 deletions(-)

diff --git a/src/PVE/LXC.pm b/src/PVE/LXC.pm
index 6023334..6bd0d5d 100644
--- a/src/PVE/LXC.pm
+++ b/src/PVE/LXC.pm
@@ -1795,11 +1795,12 @@ sub snapshot_create {
 	my $rootinfo = parse_ct_mountpoint($conf->{rootfs});
 	my $volid = $rootinfo->{volume};
 
+	PVE::Storage::volume_snapshot($storecfg, $volid, $snapname);
+
 	if ($running) {
 	    PVE::Tools::run_command(['/usr/bin/lxc-unfreeze', '-n', $vmid]);
 	};
 
-	PVE::Storage::volume_snapshot($storecfg, $volid, $snapname);
 	&$snapshot_commit($vmid, $snapname);
     };
     if(my $err = $@) {
@@ -1840,17 +1841,17 @@ sub snapshot_delete {
     my $del_snap =  sub {
 
 	check_lock($conf);
-
-	if ($conf->{parent} eq $snapname) {
-	    if ($conf->{snapshots}->{$snapname}->{snapname}) {
-		$conf->{parent} = $conf->{snapshots}->{$snapname}->{parent};
-	    } else {
-		delete $conf->{parent};
+	my $grand_parent = $conf->{snapshots}->{$snapname}->{parent};
+	foreach my $snapkey (keys %{$conf->{snapshots}}) {
+	    if ($conf->{snapshots}->{$snapkey}->{parent} eq $snapname) {
+		if ($grand_parent) {
+		    $conf->{snapshots}->{$snapkey}->{parent} = $grand_parent;
+		} else {
+	            delete $conf->{snapshots}->{$snapkey}->{parent};
+		}
 	    }
 	}
-
 	delete $conf->{snapshots}->{$snapname};
-
 	write_config($vmid, $conf);
     };
 
@@ -1904,30 +1905,25 @@ sub snapshot_rollback {
 
 	$conf->{lock} = 'rollback';
 
-	my $forcemachine;
-
-	# copy snapshot config to current config
-
-	my $tmp_conf = $conf;
-	&$snapshot_copy_config($tmp_conf->{snapshots}->{$snapname}, $conf);
-	$conf->{snapshots} = $tmp_conf->{snapshots};
-	delete $conf->{snaptime};
-	delete $conf->{snapname};
-	$conf->{parent} = $snapname;
-
 	write_config($vmid, $conf);
-    };
 
-    my $unlockfn = sub {
-	delete $conf->{lock};
-	write_config($vmid, $conf);
     };
 
     lock_container($vmid, 10, $updatefn);
 
-    PVE::Storage::volume_snapshot_rollback($storecfg, $volid, $snapname);
+    eval {
+        PVE::Storage::volume_snapshot_rollback($storecfg, $volid, $snapname);
+    };
+
+    die "Container stopped but the snapshot could not be rolled back.\n" . $@ if $@;
+
+    # copy snapshot config to current config
 
-    lock_container($vmid, 5, $unlockfn);
+    delete $conf->{parent};
+    $conf->{parent} = $snapname;
+    &$snapshot_copy_config($conf->{snapshots}->{$snapname}, $conf);
+    delete $conf->{lock};
+    write_config($vmid, $conf);
 }
 
 sub template_create {
@@ -2189,7 +2185,7 @@ sub mountpoint_mount {
 	    if ($scfg->{path}) {
 		push @extra_opts, '-o', 'loop';
 		$use_loopdev = 1;
-	    } elsif ($scfg->{type} eq 'drbd' || $scfg->{type} eq 'lvm' || $scfg->{type} eq 'rbd') {
+	    } elsif ($scfg->{type} eq 'lvmthin' || $scfg->{type} eq 'drbd' || $scfg->{type} eq 'lvm' || $scfg->{type} eq 'rbd') {
 		# do nothing
 	    } else {
 		die "unsupported storage type '$scfg->{type}'\n";
@@ -2321,6 +2317,10 @@ sub create_disks {
 							   undef, 0);
 			push @$chown_vollist, $volid;
 		    }
+		} elsif ($scfg->{type} eq 'lvmthin') {
+			$volid = PVE::Storage::vdisk_alloc($storecfg, $storage, $vmid, 'raw',
+							   undef, $size_kb);
+			format_disk($storecfg, $volid, $rootuid, $rootgid);
 		} elsif ($scfg->{type} eq 'zfspool') {
 
 		    $volid = PVE::Storage::vdisk_alloc($storecfg, $storage, $vmid, 'subvol',
-- 
2.1.4