[PATCH] xenbus: don't look up transaction IDs for ordinary writes

["Jan Beulich" <JBeulich@suse.com>]

This should really only be done for XS_TRANSACTION_END messages, or
else at least some of the xenstore-* tools don't work anymore.

Fixes: 0beef634b8 ("xenbus: don't BUG() on user mode induced condition")
Reported-by: Richard Schütz <rschuetz@uni-koblenz.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Tested-by: Richard Schütz <rschuetz@uni-koblenz.de>
---
 drivers/xen/xenbus/xenbus_dev_frontend.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- 4.8-rc2/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ 4.8-rc2-xen-xenbus-dev-write-oridinary/drivers/xen/xenbus/xenbus_dev_frontend.c
@@ -316,7 +316,7 @@ static int xenbus_write_transaction(unsi
 			rc = -ENOMEM;
 			goto out;
 		}
-	} else {
+	} else if (msg_type == XS_TRANSACTION_END) {
 		list_for_each_entry(trans, &u->transactions, list)
 			if (trans->handle.id == u->u.msg.tx_id)
 				break;