On 16.06.21 16:43, Julien Grall wrote:
> From: Julien Grall <jgrall@amazon.com>
> 
> Currently, only Live-Update request can be delayed. In a follow-up,
> we will want to delay more requests (e.g. transaction start).
> Therefore we want to preserve delayed requests across Live-Update.
> 
> Delayed requests are just complete "in" buffer. So the code is
> refactored to allow sharing the code to dump "in" buffer.
> 
> Signed-off-by: Julien Grall <jgrall@amazon.com>
> ---
>   tools/xenstore/xenstored_core.c | 42 +++++++++++++++++++++++++--------
>   1 file changed, 32 insertions(+), 10 deletions(-)
> 
> diff --git a/tools/xenstore/xenstored_core.c b/tools/xenstore/xenstored_core.c
> index 5b7ab7f74013..9eca58682b51 100644
> --- a/tools/xenstore/xenstored_core.c
> +++ b/tools/xenstore/xenstored_core.c
> @@ -2403,25 +2403,47 @@ const char *dump_state_global(FILE *fp)
>   	return NULL;
>   }
>   
> +static const char *dump_input_buffered_data(FILE *fp,
> +					    const struct buffered_data *in,
> +					    unsigned int *total_len)
> +{
> +	unsigned int hlen = in->inhdr ? in->used : sizeof(in->hdr);
> +
> +	*total_len += hlen;
> +	if (fp && fwrite(&in->hdr, hlen, 1, fp) != 1)
> +		return "Dump read data error";
> +	if (!in->inhdr && in->used) {
> +		*total_len += in->used;
> +		if (fp && fwrite(in->buffer, in->used, 1, fp) != 1)
> +			return "Dump read data error";
> +	}
> +
> +	return NULL;
> +}
> +
>   /* Called twice: first with fp == NULL to get length, then for writing data. */
>   const char *dump_state_buffered_data(FILE *fp, const struct connection *c,
>   				     struct xs_state_connection *sc)
>   {
>   	unsigned int len = 0, used;
> -	struct buffered_data *out, *in = c->in;
> +	struct buffered_data *out;
>   	bool partial = true;
> +	struct delayed_request *req;
> +	const char *ret;
>   
> -	if (in) {
> -		len = in->inhdr ? in->used : sizeof(in->hdr);
> -		if (fp && fwrite(&in->hdr, len, 1, fp) != 1)
> -			return "Dump read data error";
> -		if (!in->inhdr && in->used) {
> -			len += in->used;
> -			if (fp && fwrite(in->buffer, in->used, 1, fp) != 1)
> -				return "Dump read data error";
> -		}
> +	/* Dump any command that was delayed */
> +	list_for_each_entry(req, &c->delayed, list) {

Please add a comment here that the following if() serves especially to
avoid dumping the data for do_lu_start().

> +		if (req->func != process_delayed_message)
> +			continue;
> +
> +		assert(!req->in->inhdr);
> +		if ((ret = dump_input_buffered_data(fp, req->in, &len)))
> +			return ret;
>   	}
>   
> +	if (c->in && (ret = dump_input_buffered_data(fp, c->in, &len)))
> +		return ret;
> +
>   	if (sc) {
>   		sc->data_in_len = len;
>   		sc->data_resp_len = 0;
> 

Juergen