feat(backups): block snapshot migration during backup

Related to zammad#16108

@xen-orchestra/backups/_runners/_vmRunners/_AbstractXapi.mjs

@@ -256,7 +256,15 @@ export const AbstractXapi = class AbstractXapiVmBackupRunner extends Abstract {
       }
 
       if (this._writers.size !== 0) {
-        await this._copy()
+        const { pool_migrate = null, migrate_send = null } = this._exportedVm.blocked_operations
+
+        const reason = 'VM migration is blocked during backup'
+        await this._exportedVm.update_blocked_operations({ pool_migrate: reason, migrate_send: reason })
+        try {
+          await this._copy()
+        } finally {
+          await this._exportedVm.update_blocked_operations({ pool_migrate, migrate_send })
+        }
       }
     } finally {
       if (startAfter) {

CHANGELOG.unreleased.md

@@ -9,6 +9,7 @@
 
 - [Host/Advanced] Display system disks health based on the _smartctl_ plugin. [#4458](https://github.com/vatesfr/xen-orchestra/issues/4458) (PR [#7060](https://github.com/vatesfr/xen-orchestra/pull/7060))
 - [Authentication] Failed attempts are now logged as XO tasks (PR [#7061](https://github.com/vatesfr/xen-orchestra/pull/7061))
+- [Backup] Prevent VMs from being migrated while they are backed up (PR [#7024](https://github.com/vatesfr/xen-orchestra/pull/7024))
 
 ### Bug fixes
 
@@ -34,6 +35,7 @@
 
 <!--packages-start-->
 
+- @xen-orchestra/backups minor
 - @xen-orchestra/mixins minor
 - @xen-orchestra/xapi minor
 - vhd-lib patch