Re: [PATCH 03/10] tools/xenstore: Don't assume conn->in points to the LU request

[Juergen Gross]

On 24.06.21 09:56, Luca Fancellu wrote:

On 24 Jun 2021, at 08:34, Juergen Gross <jgr...@suse.com> wrote:

On 24.06.21 09:32, Juergen Gross wrote:

On 16.06.21 16:43, Julien Grall wrote:

From: Julien Grall <jgr...@amazon.com>

call_delayed() is currently assuming that conn->in is NULL when
handling delayed request. However, the connection is not paused.
Therefore new request can be processed and conn->in may be non-NULL
if we have only received a partial request.

Furthermore, as we overwrite conn->in, the current partial request
will not be transferred. This will result to corrupt the connection.

Rather than updating conn->in, stash the LU request in lu_status and
let each callback for delayed request to update conn->in when
necessary.

To keep a sane interface, the code to write the "OK" response the
LU request is moved in xenstored_core.c.

Fixes: c5ca1404b4 ("tools/xenstore: add support for delaying execution

of a xenstore request")

Fixes: ed6eebf17d ("tools/xenstore: dump the xenstore state for live

update")

Signed-off-by: Julien Grall <jgr...@amazon.com>

With dropping the conn parameter from call_delayed as already
mentioned by Luca you can add my:

Oh, please drop my request to delete the conn parameter, as it is being
used in patch 4 again.

Reviewed-by: Juergen Gross <jgr...@suse.com>

This stands, of course.

Hi Juergen,

I’m sorry but I don’t see when the parameter is used, in patch 4 we have this 
call:

line 2344:
         if (delayed_requests) {
             list_for_each_entry(conn, &connections, list) {
                 struct delayed_request *req, *tmp;

                 list_for_each_entry_safe(req, tmp,
                              &conn->delayed, list)
                     call_delayed(conn, req);
             }
         }

But call_delayed is still this one:

Line 273:
static void call_delayed(struct connection *conn, struct delayed_request *req)
{
     if (req->func(req)) {
         undelay_request(req);
         talloc_set_destructor(req, NULL);
     }
}

Am I missing something?

Hmm, I seem to have mixed up something.

Yes, you are right. So off with the conn parameter (again).


Juergen

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