refactor delete_snapshot for readability

[pve-common.git] / src / PVE / AbstractConfig.pm

diff --git a/src/PVE/AbstractConfig.pm b/src/PVE/AbstractConfig.pm
index be6eb5cbb535b9d3fd42c65e6297f5737cfe2fb7..7395768bc3b9e0e50aac4982b0769f140f448580 100644 (file)
--- a/src/PVE/AbstractConfig.pm
+++ b/src/PVE/AbstractConfig.pm
@@ -136,9 +136,10 @@ sub remove_lock {
     $class->lock_config($vmid, sub {
        my $conf = $class->load_config($vmid);
        if (!$conf->{lock}) {
-           die "no lock found trying to remove lock '$lock'\n";
+           my $lockstring = defined($lock) ? "'$lock' " : "any";
+           die "no lock found trying to remove $lockstring lock\n";
        } elsif (defined($lock) && $conf->{lock} ne $lock) {
-           die "found lock '$conf->{lock}' trying to remove lock '$lock'\n";
+           die "found lock '$conf->{lock}' trying to remove '$lock' lock\n";
        }
        delete $conf->{lock};
        $class->write_config($vmid, $conf);
@@ -221,6 +222,14 @@ sub __snapshot_freeze {
     die "abstract method - implement me\n";
 }
 
+# Code run before and after creating all the volume snapshots
+# base: noop
+sub __snapshot_create_vol_snapshots_hook {
+    my ($class, $vmid, $snap, $running, $hook) = @_;
+
+    return;
+}
+
 # Create the volume snapshots for the VM/CT.
 sub __snapshot_create_vol_snapshot {
     my ($class, $vmid, $vs, $volume, $snapname) = @_;
@@ -230,7 +239,7 @@ sub __snapshot_create_vol_snapshot {
 
 # Remove a drive from the snapshot config.
 sub __snapshot_delete_remove_drive {
-    my ($class, $snap, $remove_drive) = @_;
+    my ($class, $snap, $drive) = @_;
 
     die "abstract method - implement me\n";
 }
@@ -277,6 +286,13 @@ sub __snapshot_rollback_vm_start {
     die "abstract method - implement me\n";
 }
 
+# Get list of volume IDs which are referenced in $conf, but not in $snap.
+sub __snapshot_rollback_get_unused {
+    my ($class, $conf, $snap) = @_;
+
+    die "abstract method - implement me\n";
+}
+
 # Iterate over all configured volumes, calling $func for each key/value pair.
 sub __snapshot_foreach_volume {
     my ($class, $conf, $func) = @_;
@@ -413,6 +429,8 @@ sub snapshot_create {
            $class->__snapshot_freeze($vmid, 0);
        }
 
+       $class->__snapshot_create_vol_snapshots_hook($vmid, $snap, $running, "before");
+
        $class->__snapshot_foreach_volume($snap, sub {
            my ($vs, $volume) = @_;
 
@@ -423,9 +441,11 @@ sub snapshot_create {
     my $err = $@;
 
     if ($running) {
+       $class->__snapshot_create_vol_snapshots_hook($vmid, $snap, $running, "after");
        if ($freezefs) {
            $class->__snapshot_freeze($vmid, 1);
        }
+       $class->__snapshot_create_vol_snapshots_hook($vmid, $snap, $running, "after-unfreeze");
     }
 
     if ($err) {
@@ -448,6 +468,9 @@ sub snapshot_delete {
     my $snap;
     my $unused = [];
 
+    $class->set_lock($vmid, 'snapshot-delete')
+       if (!$drivehash); # doesn't already have a 'snapshot' lock
+
     my $unlink_parent = sub {
        my ($confref, $new_parent) = @_;
 
@@ -460,55 +483,39 @@ sub snapshot_delete {
        }
     };
 
-    my $updatefn =  sub {
-       my ($remove_drive) = @_;
+    my $remove_drive = sub {
+       my ($drive) = @_;
 
        my $conf = $class->load_config($vmid);
+       $snap = $conf->{snapshots}->{$snapname};
+       die "snapshot '$snapname' does not exist\n" if !defined($snap);
 
-       if (!$drivehash) {
-           $class->check_lock($conf);
-           die "you can't delete a snapshot if vm is a template\n"
-               if $class->is_template($conf);
-       }
+       $class->__snapshot_delete_remove_drive($snap, $drive);
 
-       $snap = $conf->{snapshots}->{$snapname};
+       $class->write_config($vmid, $conf);
+    };
 
-       die "snapshot '$snapname' does not exist\n" if !defined($snap);
+    #prepare
+    $class->lock_config($vmid, sub {
+       my $conf = $class->load_config($vmid);
 
-       # remove parent refs
-       if (!$prepare) {
-           &$unlink_parent($conf, $snap->{parent});
-           foreach my $sn (keys %{$conf->{snapshots}}) {
-               next if $sn eq $snapname;
-               &$unlink_parent($conf->{snapshots}->{$sn}, $snap->{parent});
-           }
-       }
+       die "you can't delete a snapshot if vm is a template\n"
+           if $class->is_template($conf);
 
-       if ($remove_drive) {
-           $class->__snapshot_delete_remove_drive($snap, $remove_drive);
-       }
+       $snap = $conf->{snapshots}->{$snapname};
+       die "snapshot '$snapname' does not exist\n" if !defined($snap);
 
-       if ($prepare) {
-           $snap->{snapstate} = 'delete';
-       } else {
-           delete $conf->{snapshots}->{$snapname};
-           delete $conf->{lock} if $drivehash;
-           foreach my $volid (@$unused) {
-               $class->add_unused_volume($conf, $volid);
-           }
-       }
+       $snap->{snapstate} = 'delete';
 
        $class->write_config($vmid, $conf);
-    };
-
-    $class->lock_config($vmid, $updatefn);
+    });
 
     # now remove vmstate file
     if ($snap->{vmstate}) {
        $class->__snapshot_delete_vmstate_file($snap, $force);
 
        # save changes (remove vmstate from snapshot)
-       $class->lock_config($vmid, $updatefn, 'vmstate') if !$force;
+       $class->lock_config($vmid, $remove_drive, 'vmstate') if !$force;
     };
 
     # now remove all volume snapshots
@@ -517,21 +524,39 @@ sub snapshot_delete {
 
        return if $snapname eq 'vzdump' && $vs ne 'rootfs' && !$volume->{backup};
        if (!$drivehash || $drivehash->{$vs}) {
-           eval { $class->__snapshot_delete_vol_snapshot($vmid, $vs, $volume, $snapname); };
+           eval { $class->__snapshot_delete_vol_snapshot($vmid, $vs, $volume, $snapname, $unused); };
            if (my $err = $@) {
                die $err if !$force;
                warn $err;
            }
        }
 
-       # save changes (remove mp from snapshot)
-       $class->lock_config($vmid, $updatefn, $vs) if !$force;
-       push @$unused, $volume->{volume};
+       # save changes (remove drive from snapshot)
+       $class->lock_config($vmid, $remove_drive, $vs) if !$force;
     });
 
     # now cleanup config
-    $prepare = 0;
-    $class->lock_config($vmid, $updatefn);
+    $class->lock_config($vmid, sub {
+       my $conf = $class->load_config($vmid);
+       $snap = $conf->{snapshots}->{$snapname};
+       die "snapshot '$snapname' does not exist\n" if !defined($snap);
+
+       # remove parent refs
+       &$unlink_parent($conf, $snap->{parent});
+       foreach my $sn (keys %{$conf->{snapshots}}) {
+           next if $sn eq $snapname;
+           &$unlink_parent($conf->{snapshots}->{$sn}, $snap->{parent});
+       }
+
+
+       delete $conf->{snapshots}->{$snapname};
+       delete $conf->{lock};
+       foreach my $volid (@$unused) {
+           $class->add_unused_volume($conf, $volid);
+       }
+
+       $class->write_config($vmid, $conf);
+    });
 }
 
 # Rolls back to a given snapshot.
@@ -591,6 +616,12 @@ sub snapshot_rollback {
        my $forcemachine;
 
        if (!$prepare) {
+           my $unused = $class->__snapshot_rollback_get_unused($conf, $snap);
+
+           foreach my $volid (@$unused) {
+               $class->add_unused_volume($conf, $volid);
+           }
+
            my $has_machine_config = defined($conf->{machine});
 
            # copy snapshot config to current config