[libvirt] [PATCH] qemu_blockjob: Remove image metadata on blockcommit

[Michal Privoznik]

On 9/16/19 9:40 AM, Peter Krempa wrote:
> On Mon, Sep 16, 2019 at 08:49:37 +0200, Michal Privoznik wrote:
>> When doing a blockcommit, the base and possibly top parent are
>> relabelled in qemuDomainBlockCommit(). However, once the block
>> job is finished, we need to remove the secdriver metadata
>> (XATTRs) created at the beginning.
>>
>> Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1741456
>>
>> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
>> ---
>>   src/qemu/qemu_blockjob.c | 19 +++++++++++++++++++
>>   1 file changed, 19 insertions(+)
>>
>> diff --git a/src/qemu/qemu_blockjob.c b/src/qemu/qemu_blockjob.c
>> index a991309ee7..47715f12f6 100644
>> --- a/src/qemu/qemu_blockjob.c
>> +++ b/src/qemu/qemu_blockjob.c
>> @@ -677,6 +677,25 @@ qemuBlockJobEventProcessLegacyCompleted(virQEMUDriverPtr driver,
>>               }
>>   
>>               virObjectUnref(disk->mirror);
>> +        } else if (job->type == QEMU_BLOCKJOB_TYPE_COMMIT) {
>> +            if (qemuSecurityMoveImageMetadata(driver, vm,
>> +                                              job->data.commit.base, NULL) < 0) {
>> +                VIR_WARN("Unable to remove disk metadata on "
>> +                         "vm %s from %s (disk target %s)",
>> +                         vm->def->name,
>> +                         NULLSTR(job->data.commit.base->path),
>> +                         disk->dst);
>> +            }
>> +            if (job->data.commit.topparent &&
>> +                job->data.commit.topparent != disk->src &&
>> +                qemuSecurityMoveImageMetadata(driver, vm,
>> +                                              job->data.commit.topparent, NULL) < 0) {
>> +                VIR_WARN("Unable to remove disk metadata on "
>> +                         "vm %s from %s (disk target %s)",
>> +                         vm->def->name,
>> +                         NULLSTR(job->data.commit.topparent->path),
>> +                         disk->dst);
>> +            }
> 
> NACK, the legacy block job handler was never designed to touch job->data
> in any way. I don't want to guarantee that the blockjob code bits work
> with the legacy code bits in any way.
> 
> Specifically the problem is that any of this data will NOT be available
> after libvirtd restart because all of the job tracking in the status XML
> is only done when QEMU_CAPS_BLOCKDEV is enabled.
> 

So how do you suggest I fix this? Steps to reproduce are here:

https://bugzilla.redhat.com/show_bug.cgi?id=1741456#c8

Michal