[PATCH qemu-server v2 2/3] fix #7743: api: disk import: avoid locking twice when importing from OVA or same VM

[Fiona Ebner <f.ebner@proxmox.com>]

When import_from_volid->() is called, the VM configuration of the
destination VM is already locked. In case the source volume belongs to
the same VM, there would be a second attempt to lock the config. In
particular, this also happens when importing from OVA, because the
source image is first extracted and belongs to the same VM.

The reason this fixes bug #7743, is that the API call will lock before
forking a worker in the POST case, making a second lock attempt from
the different process fail. In the PUT case, the second lock attempt
will still succeed, because the lock is cached within the process in
PVE::Tools::lock_file_full(). Commit "api: update vm: fork before
locking" will address this second part of the issue.

Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
Tested-by: Manuel Federanko <m.federanko@proxmox.com>
Reviewed-by: Dominik Csapak <d.csapak@proxmox.com>
---
 src/PVE/API2/Qemu.pm | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/PVE/API2/Qemu.pm b/src/PVE/API2/Qemu.pm
index e575d36b..b2a15d96 100644
--- a/src/PVE/API2/Qemu.pm
+++ b/src/PVE/API2/Qemu.pm
@@ -390,10 +390,13 @@ my $import_from_volid = sub {
     };
 
     my $cloned;
-    if ($running) {
-        $cloned = PVE::QemuConfig->lock_config_full($src_vmid, 30, $clonefn);
-    } elsif ($src_vmid) {
-        $cloned = PVE::QemuConfig->lock_config_shared($src_vmid, 30, $clonefn);
+    # The config is already locked for the destination.
+    if ($src_vmid && $src_vmid != $dest_info->{vmid}) {
+        if ($running) {
+            $cloned = PVE::QemuConfig->lock_config_full($src_vmid, 30, $clonefn);
+        } else {
+            $cloned = PVE::QemuConfig->lock_config_shared($src_vmid, 30, $clonefn);
+        }
     } else {
         $cloned = $clonefn->();
     }
-- 
2.47.3