[pve-devel] [PATCH qemu-server 1/1] make the timeout value editable when the VM is locked

[Daniel Tschlatscher <d.tschlatscher@proxmox.com>]

In some cases the VM could no longer start when the timeout value was
set to a very low value and afterwards, for example, hibernated. In
this case the VM is somewhat soft locked, because the API would not
allow changing the timeout value anymore. (The only way out here would
be to change the value manually in the config)

Signed-off-by: Daniel Tschlatscher <d.tschlatscher@proxmox.com>
---
To make it possible to change the timeout config value when the VM
is locked I created a function to tell whether the config should
be editable or not. This reduces clutter in the already rather long
invoking function. I also tried to keep it extensible for possible
existing values that could be included here/are added in the future.

Nonetheless, I am open to suggestions for a possibly more elegant
solution with this function.
Also, I am not quite sure about storing the "allowed" fields hardcoded
in the function. But I also didn't find where a good place to store 
such a "constant" in this repository would be.

 PVE/API2/Qemu.pm | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
index db21fd8..f37baa4 100644
--- a/PVE/API2/Qemu.pm
+++ b/PVE/API2/Qemu.pm
@@ -8,6 +8,7 @@ use POSIX;
 use IO::Socket::IP;
 use URI::Escape;
 use Crypt::OpenSSL::Random;
+use List::Util qw(first);
 
 use PVE::Cluster qw (cfs_read_file cfs_write_file);;
 use PVE::RRD;
@@ -625,6 +626,28 @@ my $check_vm_modify_config_perm = sub {
     return 1;
 };
 
+# Certain fields should still be editable when the VM is locked 
+# For now, this means that only if those certain fields are edited/deleted will the result be true
+sub skiplock_for_allowed_fields {
+    my ($param, @deleted) = @_;
+    
+    my @allowed = qw"timeout";
+    my $skiplock = 1;
+
+    my @to_check = @deleted;
+    for (keys %$param) {
+	push(@to_check, $_);
+    }
+
+    my $idx = 0;
+    while ($skiplock && $idx < keys @to_check) {
+	$skiplock = first { $_ eq $to_check[$idx] } @allowed;
+	$idx++;
+    }
+
+    return $skiplock;
+}
+
 __PACKAGE__->register_method({
     name => 'vmlist',
     path => '',
@@ -1455,7 +1478,9 @@ my $update_vm_api  = sub {
 	    push @delete, 'runningcpu' if $conf->{runningcpu};
 	}
 
-	PVE::QemuConfig->check_lock($conf) if !$skiplock;
+	if (!$skiplock && !skiplock_for_allowed_fields($param, @delete)) {
+	    PVE::QemuConfig->check_lock($conf);
+	}
 
 	foreach my $opt (keys %$revert) {
 	    if (defined($conf->{$opt})) {
-- 
2.30.2