[libvirt] [PATCH 1/2] qemuDomainUndefineFlags: Grab QEMU_JOB_MODIFY

[John Ferlan]

On 08/07/2017 08:20 AM, Michal Privoznik wrote:
> This API is definitely modifying state of @vm. Therefore it
> should grab a job.
> 
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
>  src/qemu/qemu_driver.c | 23 ++++++++++++++---------
>  1 file changed, 14 insertions(+), 9 deletions(-)
> 

Not sure which of or if this patch from the two undefine series is
active, but I wonder how this "interacts or intersects" with:

https://www.redhat.com/archives/libvir-list/2017-July/msg00921.html

which was posted late last month... I looked at it, but really hadn't
dug into yet.  The summary of the linked patch is it's possible to run
an undefine while a define is occurring because locks are dropped during
launch processing. However, if there's a job, then wouldn't that mean
it'd be less likely or impossible to allow that undefine while the
define job was happening?  Of course as Martin notes RemoveInactive
cannot be run with a job, but the problem from the other patch is that
the RemoveInactive is at least partially successful.

I guess I just wanted to be sure to note the link between the two just
in case you were actively still thinking about this one (and had better
ideas for the other patch where I went with the first thing that came to
mind w/r/t using a flag).

John


> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c
> index b3f65f440..574c351ae 100644
> --- a/src/qemu/qemu_driver.c
> +++ b/src/qemu/qemu_driver.c
> @@ -7325,10 +7325,13 @@ qemuDomainUndefineFlags(virDomainPtr dom,
>      if (virDomainUndefineFlagsEnsureACL(dom->conn, vm->def) < 0)
>          goto cleanup;
>  
> +    if (qemuDomainObjBeginJob(driver, vm, QEMU_JOB_MODIFY) < 0)
> +        goto cleanup;
> +
>      if (!vm->persistent) {
>          virReportError(VIR_ERR_OPERATION_INVALID,
>                         "%s", _("cannot undefine transient domain"));
> -        goto cleanup;
> +        goto endjob;
>      }
>  
>      if (!virDomainObjIsActive(vm) &&
> @@ -7338,15 +7341,15 @@ qemuDomainUndefineFlags(virDomainPtr dom,
>                             _("cannot delete inactive domain with %d "
>                               "snapshots"),
>                             nsnapshots);
> -            goto cleanup;
> +            goto endjob;
>          }
>          if (qemuDomainSnapshotDiscardAllMetadata(driver, vm) < 0)
> -            goto cleanup;
> +            goto endjob;
>      }
>  
>      name = qemuDomainManagedSavePath(driver, vm);
>      if (name == NULL)
> -        goto cleanup;
> +        goto endjob;
>  
>      if (virFileExists(name)) {
>          if (flags & VIR_DOMAIN_UNDEFINE_MANAGED_SAVE) {
> @@ -7354,13 +7357,13 @@ qemuDomainUndefineFlags(virDomainPtr dom,
>                  virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>                                 _("Failed to remove domain managed "
>                                   "save image"));
> -                goto cleanup;
> +                goto endjob;
>              }
>          } else {
>              virReportError(VIR_ERR_OPERATION_INVALID, "%s",
>                             _("Refusing to undefine while domain managed "
>                               "save image exists"));
> -            goto cleanup;
> +            goto endjob;
>          }
>      }
>  
> @@ -7372,17 +7375,17 @@ qemuDomainUndefineFlags(virDomainPtr dom,
>                  virReportSystemError(errno,
>                                       _("failed to remove nvram: %s"),
>                                       vm->def->os.loader->nvram);
> -                goto cleanup;
> +                goto endjob;
>              }
>          } else if (!(flags & VIR_DOMAIN_UNDEFINE_KEEP_NVRAM)) {
>              virReportError(VIR_ERR_OPERATION_INVALID, "%s",
>                             _("cannot delete inactive domain with nvram"));
> -            goto cleanup;
> +            goto endjob;
>          }
>      }
>  
>      if (virDomainDeleteConfig(cfg->configDir, cfg->autostartDir, vm) < 0)
> -        goto cleanup;
> +        goto endjob;
>  
>      event = virDomainEventLifecycleNewFromObj(vm,
>                                       VIR_DOMAIN_EVENT_UNDEFINED,
> @@ -7399,6 +7402,8 @@ qemuDomainUndefineFlags(virDomainPtr dom,
>          qemuDomainRemoveInactive(driver, vm);
>  
>      ret = 0;
> + endjob:
> +    qemuDomainObjEndJob(driver, vm);
>  
>   cleanup:
>      VIR_FREE(name);
>