[libvirt] [PATCH v2] qemu: disable external snapshot of readonly disk

[Nikolay Shirokovskiy]

On 10.12.2018 20:23, John Ferlan wrote:
> 
> 
> On 11/9/18 3:00 AM, Nikolay Shirokovskiy wrote:
>> Disable external snapshot of readonly disk for inactive domains
>> as this operation is not very useful. As to active domains
>> such snapshot was not possible before already but error message was
>> not helpful so now it will be better.
>>
>> Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy at virtuozzo.com>
>> ---
>>
>> Diff from v1 [1]
>> ================
>>
>> - move check to qemuDomainSnapshotPrepareDiskExternal
>> - disable such snapshot for inactive domain as well
>>
>>
>> [1]  [PATCH] qemu: snapshot: better error for active external readonly disk
>> https://www.redhat.com/archives/libvir-list/2018-October/msg01322.html
>>   continues in
>> https://www.redhat.com/archives/libvir-list/2018-November/msg00265.html
>>
>>
>>  src/qemu/qemu_driver.c | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
> 
> Do you mind if I "merge" some details from the first patch on this to
> generate the following commit message?:
> 
>     Disable external snapshot of a readonly disk for domains as
>     this operation is not very useful. Such a snapshot is not
>     possible for active domains but the error message from QEMU
>     is more cryptic:
> 
>        error: internal error: unable to execute QEMU command 'transaction':
>                            Could not create file: Permission denied
> 
>     This error at least makes the error more understandable for
> active domains and disallows for inactive domains as well.

Not at all.

> 
> 
> Reviewed-by: John Ferlan <jferlan at redhat.com>
> 

Thanx, pushed.

Nikolay