[PATCH 3.16 343/346] xenbus: don't look up transaction IDs for ordinary writes

[Ben Hutchings]

3.16.39-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Jan Beulich <JBeulich@xxxxxxxx>

commit 9a035a40f7f3f6708b79224b86c5777a3334f7ea upstream.

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 SchÃtz <rschuetz@xxxxxxxxxxxxxx>
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Tested-by: Richard SchÃtz <rschuetz@xxxxxxxxxxxxxx>
Signed-off-by: David Vrabel <david.vrabel@xxxxxxxxxx>
Cc: Ed Swierk <eswierk@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/xen/xenbus/xenbus_dev_frontend.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/xen/xenbus/xenbus_dev_frontend.c
+++ b/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;