Re: [pve-devel] [PATCH v3 guest-common 1/1] guest helpers: add run_with_replication_guard

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

Am 22.02.22 um 11:27 schrieb Fabian Grünbichler:
> On February 22, 2022 10:41 am, Fabian Ebner wrote:
>> Am 21.02.22 um 12:58 schrieb Fabian Ebner:
>>> @@ -82,6 +83,18 @@ sub guest_migration_lock {
>>>      return $res;
>>>  }
>>>  
>>> +sub run_with_replication_guard {
>>> +    my ($vmid, $timeout, $log, $func, @param) = @_;
>>> +
>>> +    my $repl_conf = PVE::ReplicationConfig->new();
>>> +    if ($repl_conf->check_for_existing_jobs($vmid, 1)) {
>>> +	$log->("checking/waiting for active replication..") if $log;
>>> +	guest_migration_lock($vmid, $timeout, $func, @param);
>>
>> I wonder if we should unconditionally take the lock? If not, we can race
>> with a newly created replication job:
>> 1. snapshot deletion starts
>> 2. replication job is created
>> 3. replication job starts
>> 4. snapshot deletion runs into 'dataset is busy' error, because snapshot
>> is used by replication
> 
> that could also be solved by lock_config on the guest config when 
> creating/modifying a replication job, but unconditionally trying to 
> obtain the lock is also fine by me.
> 

Should be enough to do upon creation and would also fix a race between
creating a replication job and adding a non-replicatable disk.