Re: [PATCH] box: ensure fiber processing box.cfg doesn't process messages from iproto

[Serge Petrenko <sergepetrenko@tarantool.org>]

Hi!

12 нояб. 2018 г., в 14:40, Vladimir Davydov <vdavydov.dev@gmail.com> написал(а):
> 
> On Sat, Nov 10, 2018 at 02:24:36PM +0300, Serge Petrenko wrote:
>> 
>> diff --git a/src/box/gc.c b/src/box/gc.c
>> index 467eecb91..8f0ecb0b9 100644
>> --- a/src/box/gc.c
>> +++ b/src/box/gc.c
>> @@ -110,7 +110,7 @@ void
>> gc_set_wal_watcher(void)
>> {
> 
> Please add a comment to the code, otherwise the patch looks OK.

Added the comment, the diff’s below.

> 
>> 	wal_set_watcher(&gc.wal_watcher, "tx", gc_process_wal_event,
>> -			cbus_process, WAL_EVENT_GC);
>> +			NULL, WAL_EVENT_GC);
>> }
>> 
>> void


diff --git a/src/box/gc.c b/src/box/gc.c
index 467eecb91..cefe1553f 100644
--- a/src/box/gc.c
+++ b/src/box/gc.c
@@ -109,8 +109,18 @@ gc_process_wal_event(struct wal_watcher_msg *);
 void
 gc_set_wal_watcher(void)
 {
+	/*
+	 * Since the function is called from box_cfg() it is
+	 * important that we do not pass a message processing
+	 * callback to wal_set_watcher(). Doing so would cause
+	 * credentials corruption in the fiber executing
+	 * box_cfg() in case it processes some iproto messages.
+	 * Besides, by the time the function is called
+	 * tx_fiber_pool is already set up and it will process
+	 * all the messages directed to "tx" endpoint safely.
+	 */
 	wal_set_watcher(&gc.wal_watcher, "tx", gc_process_wal_event,
-			cbus_process, WAL_EVENT_GC);
+			NULL, WAL_EVENT_GC);
 }
 
 void
-- 
2.17.2 (Apple Git-113)