[PATCH atomic snapshot 3/4] storage snapshot: add optional atomic snapshot creation in snapshot_create

[Demayl]

Signed-off-by: Demayl <denis.kanchev at storpool.com>
---
 src/PVE/AbstractConfig.pm | 60 +++++++++++++++++++++++++++++++++------
 1 file changed, 51 insertions(+), 9 deletions(-)

diff --git a/src/PVE/AbstractConfig.pm b/src/PVE/AbstractConfig.pm
index 3d4fcbb..8bb271d 100644
--- a/src/PVE/AbstractConfig.pm
+++ b/src/PVE/AbstractConfig.pm
@@ -811,10 +811,39 @@ sub __snapshot_activate_storages {
     return;
 }
 
+sub get_atomic_snapshot_volumes {
+    my ($class, $conf) = @_;
+    my $volumes = {};
+    $class->foreach_volume(
+        $conf,
+        sub {
+            my ($key, $volume_string) = @_;
+            $volumes->{$key} = $volume_string;
+        }
+    );
+    return $volumes;
+}
+sub check_atomic_snapshots {
+    my ($class, $conf) = @_;
+    return PVE::Storage::volumes_atomic_snapshot_possible(
+        PVE::Storage::config(),
+        $class->get_atomic_snapshot_volumes($conf),
+    );
+}
+
+sub __snapshot_volumes_atomically {
+    my ($class, $voldata, $snapname) = @_;
+    PVE::Storage::volumes_atomic_snapshot($voldata, $snapname);
+    return { map { $_ => 1 } keys %{$voldata} };
+}
+
+
 # Creates a snapshot for the VM/CT.
+# Type can be either atomic or sequential
 sub snapshot_create {
-    my ($class, $vmid, $snapname, $save_vmstate, $comment) = @_;
+    my ($class, $vmid, $snapname, $save_vmstate, $comment, $type) = @_;
 
+    my $atomic = $type && $type eq 'atomic';
     my $snap = $class->__snapshot_prepare($vmid, $snapname, $save_vmstate, $comment);
 
     $save_vmstate = 0 if !$snap->{vmstate};
@@ -823,32 +852,45 @@ sub snapshot_create {
 
     my ($running, $freezefs) = $class->__snapshot_check_freeze_needed($vmid, $conf, $snap->{vmstate});
 
+    my ($can_atomic, undef, $vol_cfg) = $class->check_atomic_snapshots($snap);
+    if ($atomic && !$can_atomic) {
+	warn "snapshot create failed: starting cleanup\n";
+	eval { $class->snapshot_delete($vmid, $snapname, 1, {}); };
+	warn "$@" if $@;
+	die "atomic snapshot impossible for mixed storage\n";
+    }
+    my $is_atomic = $atomic && $can_atomic;
+
     my $drivehash = {};
 
     eval {
 	$class->__snapshot_activate_storages($conf, 0);
 
-	if ($freezefs) {
+	if ($freezefs && !$is_atomic) {
 	    $class->__snapshot_freeze($vmid, 0);
 	}
 
 	$class->__snapshot_create_vol_snapshots_hook($vmid, $snap, $running, "before");
 
-	$class->foreach_volume($snap, sub {
-	    my ($vs, $volume) = @_;
+	if ($is_atomic) {
+	    $drivehash = $class->__snapshot_volumes_atomically($vol_cfg, $snapname);
+	} else {
+	    $class->foreach_volume($snap, sub {
+		my ($vs, $volume) = @_;
 
-	    $class->__snapshot_create_vol_snapshot($vmid, $vs, $volume, $snapname);
-	    $drivehash->{$vs} = 1;
-	});
+		$class->__snapshot_create_vol_snapshot($vmid, $vs, $volume, $snapname);
+		$drivehash->{$vs} = 1;
+	    });
+	}
     };
     my $err = $@;
 
     if ($running) {
 	$class->__snapshot_create_vol_snapshots_hook($vmid, $snap, $running, "after");
-	if ($freezefs) {
+	if ($freezefs && !$is_atomic) {
 	    $class->__snapshot_freeze($vmid, 1);
+	    $class->__snapshot_create_vol_snapshots_hook($vmid, $snap, $running, "after-unfreeze");
 	}
-	$class->__snapshot_create_vol_snapshots_hook($vmid, $snap, $running, "after-unfreeze");
     }
 
     if ($err) {
-- 
2.43.0