Re: [pve-devel] [PATCH qemu 1/2] PVE: Don't expect complete_cb to be called outside coroutine

[Wolfgang Bumiller <w.bumiller@proxmox.com>]

On Thu, Oct 22, 2020 at 02:11:17PM +0200, Stefan Reiter wrote:
> We're at the mercy of the rest of QEMU here, and it sometimes decides to
> call pvebackup_complete_cb from a coroutine. This really doesn't matter
> to us, so don't assert and crash on it.
> 
> Signed-off-by: Stefan Reiter <s.reiter@proxmox.com>
> ---
>  pve-backup.c | 7 +++----
>  1 file changed, 3 insertions(+), 4 deletions(-)
> 
> diff --git a/pve-backup.c b/pve-backup.c
> index 53cf23ed5a..9179754dcb 100644
> --- a/pve-backup.c
> +++ b/pve-backup.c
> @@ -318,19 +318,18 @@ static void coroutine_fn pvebackup_co_complete_stream(void *opaque)
>  
>  static void pvebackup_complete_cb(void *opaque, int ret)
>  {
> -    assert(!qemu_in_coroutine());
> -
>      PVEBackupDevInfo *di = opaque;
>      di->completed_ret = ret;
>  
>      /*
>       * Schedule stream cleanup in async coroutine. close_image and finish might
> -     * take a while, so we can't block on them here.
> +     * take a while, so we can't block on them here. This way it also doesn't
> +     * matter if we're already running in a coroutine or not.
>       * Note: di is a pointer to an entry in the global backup_state struct, so
>       * it stays valid.
>       */
>      Coroutine *co = qemu_coroutine_create(pvebackup_co_complete_stream, di);
> -    aio_co_schedule(qemu_get_aio_context(), co);
> +    aio_co_enter(qemu_get_aio_context(), co);

Shouldn't this be decided based on `qemu_in_coroutine()`? Or are we
allowed to call enter regardless, I forgot...?

>  }
>  
>  static void coroutine_fn pvebackup_co_cancel(void *opaque)
> -- 
> 2.20.1