[pve-devel] [PATCH qemu-server 2/2] explain 'nocheck' in more places

["Fabian Grünbichler" <f.gruenbichler@proxmox.com>]

was only explained in git history and vm_stop, add comments in other
relevant places to avoid future breakage.

Signed-off-by: Fabian Grünbichler <f.gruenbichler@proxmox.com>
---
 PVE/API2/Qemu.pm   | 2 ++
 PVE/CLI/qm.pm      | 2 ++
 PVE/QemuMigrate.pm | 3 ++-
 PVE/QemuServer.pm  | 9 +++++++++
 4 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index 6bdcce21..badfc37b 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -3200,6 +3200,8 @@ __PACKAGE__->register_method({
 	raise_param_exc({ skiplock => "Only root may use this option." })
 	    if $skiplock && $authuser ne 'root@pam';
 
+	# nocheck is used as part of migration when config file might be still
+	# be on source node
 	my $nocheck = extract_param($param, 'nocheck');
 	raise_param_exc({ nocheck => "Only root may use this option." })
 	    if $nocheck && $authuser ne 'root@pam';
diff --git a/PVE/CLI/qm.pm b/PVE/CLI/qm.pm
index 66feecce..3e0f1289 100755
--- a/PVE/CLI/qm.pm
+++ b/PVE/CLI/qm.pm
@@ -426,6 +426,8 @@ __PACKAGE__->register_method ({
 		last;
 	    } elsif ($line =~ /^resume (\d+)$/) {
 		my $vmid = $1;
+		# check_running and vm_resume with nocheck, since local node
+		# might not have processed config move/rename yet
 		if (PVE::QemuServer::check_running($vmid, 1)) {
 		    eval { PVE::QemuServer::vm_resume($vmid, 1, 1); };
 		    if ($@) {
diff --git a/PVE/QemuMigrate.pm b/PVE/QemuMigrate.pm
index 5941cce6..5e466d95 100644
--- a/PVE/QemuMigrate.pm
+++ b/PVE/QemuMigrate.pm
@@ -1500,6 +1500,7 @@ sub phase3_cleanup {
 		    $self->{errors} = 1;
 		}
 	    } else {
+		# nocheck in case target node hasn't processed the config move/rename yet
 		my $cmd = [@{$self->{rem_ssh}}, 'qm', 'resume', $vmid, '--skiplock', '--nocheck'];
 		my $logf = sub {
 		    my $line = shift;
@@ -1561,7 +1562,7 @@ sub phase3_cleanup {
 	}
     };
 
-    # always stop local VM
+    # always stop local VM with nocheck, since config is moved already
     eval { PVE::QemuServer::vm_stop($self->{storecfg}, $vmid, 1, 1); };
     if (my $err = $@) {
 	$self->log('err', "stopping vm failed - $err");
diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index 29110c0f..e1ece548 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -2788,6 +2788,12 @@ sub check_local_storage_availability {
 sub check_running {
     my ($vmid, $nocheck, $node) = @_;
 
+    # $nocheck is set when called during a migration, in which case the config
+    # file might still or already reside on the *other* node
+    # - because rename has already happened, and current node is source
+    # - because rename hasn't happened yet, and current node is target
+    # - because rename has happened, current node is target, but hasn't yet
+    # processed it yet
     PVE::QemuConfig::assert_config_exists_on_node($vmid, $node) if !$nocheck;
     return PVE::QemuServer::Helpers::vm_running_locally($vmid);
 }
@@ -6359,6 +6365,9 @@ sub vm_suspend {
     }
 }
 
+# $nocheck is set when called as part of a migration - in this context the
+# location of the config file (source or target node) is not deterministic,
+# since migration cannot wait for pmxcfs to process the rename
 sub vm_resume {
     my ($vmid, $skiplock, $nocheck) = @_;
 
-- 
2.30.2