Re: [PATCH v4 08/10] migration: process_incoming_migration_co(): move colo part to colo

[Peter Xu <peterx@redhat.com>]

On Fri, Apr 28, 2023 at 10:49:26PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> +int coroutine_fn colo_incoming_co(void)
> +{
> +    MigrationIncomingState *mis = migration_incoming_get_current();
> +    Error *local_err = NULL;
> +    QemuThread th;
> +
> +    assert(!qemu_mutex_iothread_locked());

Is this assert reverted?  I assume it wants to guarantee BQL held rather
than not..

> +
> +    if (!migration_incoming_colo_enabled()) {
> +        return 0;
> +    }
> +
> +    /* Make sure all file formats throw away their mutable metadata */
> +    bdrv_activate_all(&local_err);
> +    if (local_err) {
> +        error_report_err(local_err);
> +        return -EINVAL;
> +    }
> +
> +    qemu_thread_create(&th, "COLO incoming", colo_process_incoming_thread,
> +                       mis, QEMU_THREAD_JOINABLE);
> +
> +    mis->colo_incoming_co = qemu_coroutine_self();
> +    qemu_coroutine_yield();
> +    mis->colo_incoming_co = NULL;
> +
> +    qemu_mutex_unlock_iothread();
> +    /* Wait checkpoint incoming thread exit before free resource */
> +    qemu_thread_join(&th);
> +    qemu_mutex_lock_iothread();
> +
> +    /* We hold the global iothread lock, so it is safe here */
> +    colo_release_ram_cache();
> +
> +    return 0;
> +}

-- 
Peter Xu