Re: [PATCH 2/2] migration/rdma: zore out head.repeat to make the error more clear

[Fabiano Rosas <farosas@suse.de>]

Li Zhijian <lizhijian@fujitsu.com> writes:

> From: Li Zhijian <lizhijian@cn.fujitsu.com>
>
> Previously, we got a confusion error that complains
> the RDMAControlHeader.repeat:
> qemu-system-x86_64: rdma: Too many requests in this message (3638950032).Bailing.
>
> Actually, it's caused by an unexpected RDMAControlHeader.type.
> After this patch, error will become:
> qemu-system-x86_64: Unknown control message QEMU FILE
>
> Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com>
> ---
>  migration/rdma.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/migration/rdma.c b/migration/rdma.c
> index a2a3db35b1..3073d9953c 100644
> --- a/migration/rdma.c
> +++ b/migration/rdma.c
> @@ -2812,7 +2812,7 @@ static ssize_t qio_channel_rdma_writev(QIOChannel *ioc,
>          size_t remaining = iov[i].iov_len;
>          uint8_t * data = (void *)iov[i].iov_base;
>          while (remaining) {
> -            RDMAControlHeader head;
> +            RDMAControlHeader head = {};
>  
>              len = MIN(remaining, RDMA_SEND_INCREMENT);
>              remaining -= len;

I'm struggling to see how head is used before we set the type a couple
of lines below. Could you expand on it?

Also, a smoke test could have caught both issues early on. Is there any
reason for not having any?