[pve-devel] [PATCH v2 guest-common 2/2] config: activate affected storages for snapshot operations

[Fabian Ebner]

For snapshot creation, the storage for the vmstate file is activated
via vdisk_alloc when the state file is created.

Do not activate the volumes themselves, as that has unnecessary side
effects (e.g. waiting for zvol device link for ZFS, mapping the volume
for RBD). If a storage can only do snapshot operations on a volume
that has been activated, it needs to activate the volume itself.

The actual implementation will be in the plugins to be able to skip
CD ROM drives and bind-mounts, etc.

Signed-off-by: Fabian Ebner <f.ebner at proxmox.com>
---
 src/PVE/AbstractConfig.pm | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/PVE/AbstractConfig.pm b/src/PVE/AbstractConfig.pm
index 0c40062..2d15388 100644
--- a/src/PVE/AbstractConfig.pm
+++ b/src/PVE/AbstractConfig.pm
@@ -786,6 +786,13 @@ sub __snapshot_commit {
     $class->lock_config($vmid, $updatefn);
 }
 
+# Activates the storages affected by the snapshot operations.
+sub __snapshot_activate_storages {
+    my ($class, $conf, $include_vmstate) = @_;
+
+    return; # FIXME PVE 8.x change to die 'implement me' and bump Breaks for older plugins
+}
+
 # Creates a snapshot for the VM/CT.
 sub snapshot_create {
     my ($class, $vmid, $snapname, $save_vmstate, $comment) = @_;
@@ -801,6 +808,8 @@ sub snapshot_create {
     my $drivehash = {};
 
     eval {
+	$class->__snapshot_activate_storages($conf, 0);
+
 	if ($freezefs) {
 	    $class->__snapshot_freeze($vmid, 0);
 	}
@@ -884,6 +893,8 @@ sub snapshot_delete {
 
     die "snapshot '$snapname' does not exist\n" if !defined($snap);
 
+    $class->__snapshot_activate_storages($snap, 1) if !$drivehash;
+
     $snapshot_delete_assert_not_needed_by_replication->($class, $vmid, $conf, $snap, $snapname)
 	if !$drivehash && !$force;
 
@@ -1085,6 +1096,8 @@ sub snapshot_rollback {
 	$snap = $get_snapshot_config->($conf);
 
 	if ($prepare) {
+	    $class->__snapshot_activate_storages($snap, 1);
+
 	    $rollback_remove_replication_snapshots->($class, $vmid, $snap, $snapname);
 
 	    $class->foreach_volume($snap, sub {
-- 
2.30.2