Re: [PATCH 2/2] io: follow coroutine AioContext in qio_channel_yield()

[Fabiano Rosas <farosas@suse.de>]

Stefan Hajnoczi <stefanha@redhat.com> writes:

> @@ -2089,10 +2088,6 @@ static void nbd_attach_aio_context(BlockDriverState *bs,
>       * the reconnect_delay_timer cannot be active here.
>       */
>      assert(!s->reconnect_delay_timer);
> -
> -    if (s->ioc) {
> -        qio_channel_attach_aio_context(s->ioc, new_context);
> -    }
>  }
>  
>  static void nbd_detach_aio_context(BlockDriverState *bs)
> @@ -2101,10 +2096,6 @@ static void nbd_detach_aio_context(BlockDriverState *bs)
>  
>      assert(!s->open_timer);
>      assert(!s->reconnect_delay_timer);
> -
> -    if (s->ioc) {
> -        qio_channel_detach_aio_context(s->ioc);
> -    }
>  }

The whole attach/detach functions could go away.

>  
>  static BlockDriver bdrv_nbd = {
> diff --git a/io/channel-command.c b/io/channel-command.c
> index 7ed726c802..1f61026222 100644
> --- a/io/channel-command.c
> +++ b/io/channel-command.c
> @@ -331,14 +331,21 @@ static int qio_channel_command_close(QIOChannel *ioc,
>  
>  
>  static void qio_channel_command_set_aio_fd_handler(QIOChannel *ioc,
> -                                                   AioContext *ctx,
> +                                                   AioContext *read_ctx,
>                                                     IOHandler *io_read,
> +                                                   AioContext *write_ctx,
>                                                     IOHandler *io_write,
>                                                     void *opaque)
>  {
>      QIOChannelCommand *cioc = QIO_CHANNEL_COMMAND(ioc);
> -    aio_set_fd_handler(ctx, cioc->readfd, io_read, NULL, NULL, NULL, opaque);
> -    aio_set_fd_handler(ctx, cioc->writefd, NULL, io_write, NULL, NULL, opaque);
> +    if (read_ctx) {
> +        aio_set_fd_handler(read_ctx, cioc->readfd, io_read, NULL,
> +                NULL, NULL, opaque);
> +    }
> +    if (write_ctx) {
> +        aio_set_fd_handler(write_ctx, cioc->writefd, NULL, io_write,
> +                NULL, NULL, opaque);
> +    }
>  }
>  
>  

...

> diff --git a/nbd/client.c b/nbd/client.c
> index 479208d5d9..81877d088d 100644
> --- a/nbd/client.c
> +++ b/nbd/client.c
> @@ -948,7 +948,7 @@ static int nbd_start_negotiate(AioContext *aio_context, QIOChannel *ioc,
>                  ioc = *outioc;
>                  if (aio_context) {
>                      qio_channel_set_blocking(ioc, false, NULL);
> -                    qio_channel_attach_aio_context(ioc, aio_context);
> +                    qio_channel_set_follow_coroutine_ctx(ioc, true);

This is actually unreachable, aio_context is always NULL here.

>                  }
>              } else {
>                  error_setg(errp, "Server does not support STARTTLS");