On Fri, Jan 11, 2013 at 17:52:23 +0100, Michal Privoznik wrote:
> At the end of migration, it is important to stop NBD
> server and thus release all allocated resources.
> ---
> src/qemu/qemu_migration.c | 28 ++++++++++++++++++++++++++++
> 1 file changed, 28 insertions(+)
>
> diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
> index 86eb4c8..a1372ed 100644
> --- a/src/qemu/qemu_migration.c
> +++ b/src/qemu/qemu_migration.c
> @@ -1501,6 +1501,32 @@ cleanup:
> return ret;
> }
>
> +static void
> +qemuMigrationStopNBDServer(virQEMUDriverPtr driver,
> + virDomainObjPtr vm,
> + qemuMigrationCookiePtr mig)
> +{
> + qemuDomainObjPrivatePtr priv = vm->privateData;
> +
> + if (!mig->nbd)
> + return;
> +
> + if (mig->nbd->port != -1)
> + VIR_WARN("This is strange. NBD port was not -1 "
> + "when shutting NDB server down");
It's so strange we should not even pass the -1 port to finish phase. It
serves no purpose. However, we should remember that nbd server was
running and stop it in that case; relying on source daemon to tell us
that nbd server was running looks quite fragile.
> +
> + if (qemuDomainObjEnterMonitorAsync(driver, vm,
> + QEMU_ASYNC_JOB_MIGRATION_IN) < 0) {
> + VIR_WARN("Unable to enter monitor");
The function already reports an error or logs a warning, this extra
warning is useless.
> + return;
> + }
> +
> + if (qemuMonitorNBDServerStop(priv->mon) < 0)
> + VIR_WARN("Unable to stop NBD server");
Shouldn't this be fatal to the migration process?
> +
> + qemuDomainObjExitMonitorWithDriver(driver, vm);
> +}
> +
> /* Validate whether the domain is safe to migrate. If vm is NULL,
> * then this is being run in the v2 Prepare stage on the destination
> * (where we only have the target xml); if vm is provided, then this
> @@ -3891,6 +3917,8 @@ qemuMigrationFinish(virQEMUDriverPtr driver,
> VIR_WARN("unable to provide network data for relocation");
> }
>
> + qemuMigrationStopNBDServer(driver, vm, mig);
> +
> if (flags & VIR_MIGRATE_PERSIST_DEST) {
> virDomainDefPtr vmdef;
> if (vm->persistent)
BTW, Is the NBD server running as a thread within qemu? That is, when we
kill qemu process in case of failed or cancelled migration, we don't
need to explicitly stop the NBD server, do we?
Jirka
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