[PATCH] tools/xenstored: Stash the correct request in lu_status->in

[Julien Grall <julien@xxxxxxx>]

From: Julien Grall <jgrall@xxxxxxxxxx>

When Live-Updating with some load, Xenstored may hit the assert
req->in == lu_status->in in do_lu_start().

This is happening because the request is stashed when Live-Update
begins. This happens in a different request (see call lu_begin()
when select the new binary) from the one performing Live-Update.

To avoid the problem, stash the request in lu_start().

Fixes: 65f19ed62aa1 ("tools/xenstore: Don't assume conn->in points to the LU 
request")
Reported-by: Michael Kurth <mku@xxxxxxxxxx>
Signed-off-by: Julien Grall <jgrall@xxxxxxxxxx>

----

This was sadly missed because the on my testing the 2 requests were
residing at the same place in memory.

This was reproduced by creating domain while Live-Updating. Without
the patch, Xenstored will crash.
---
 tools/xenstore/xenstored_control.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/xenstore/xenstored_control.c 
b/tools/xenstore/xenstored_control.c
index a1b1bd5a718d..ff9863c17fa4 100644
--- a/tools/xenstore/xenstored_control.c
+++ b/tools/xenstore/xenstored_control.c
@@ -103,7 +103,6 @@ static const char *lu_begin(struct connection *conn)
        if (!lu_status)
                return "Allocation failure.";
        lu_status->conn = conn;
-       lu_status->in = conn->in;
        talloc_set_destructor(lu_status, lu_destroy);
 
        return NULL;
@@ -757,6 +756,7 @@ static const char *lu_start(const void *ctx, struct 
connection *conn,
        lu_status->force = force;
        lu_status->timeout = to;
        lu_status->started_at = time(NULL);
+       lu_status->in = conn->in;
 
        errno = delay_request(conn, conn->in, do_lu_start, conn, false);
 
-- 
2.17.1