Re: [PATCH 1/7] block/nbd: Delete reconnect delay timer when done

2022-02-04 Thread Vladimir Sementsov-Ogievskiy

03.02.2022 19:30, Hanna Reitz wrote:

We start the reconnect delay timer to cancel the reconnection attempt
after a while.  Once nbd_co_do_establish_connection() has returned, this
attempt is over, and we no longer need the timer.

Delete it before returning from nbd_reconnect_attempt(), so that it does
not persist beyond the I/O request that was paused for reconnecting; we
do not want it to fire in a drained section, because all sort of things
can happen in such a section (e.g. the AioContext might be changed, and
we do not want the timer to fire in the wrong context; or the BDS might
even be deleted, and so the timer CB would access already-freed data).

Signed-off-by: Hanna Reitz


Reviewed-by: Vladimir Sementsov-Ogievskiy 

--
Best regards,
Vladimir



[PATCH 1/7] block/nbd: Delete reconnect delay timer when done

2022-02-03 Thread Hanna Reitz
We start the reconnect delay timer to cancel the reconnection attempt
after a while.  Once nbd_co_do_establish_connection() has returned, this
attempt is over, and we no longer need the timer.

Delete it before returning from nbd_reconnect_attempt(), so that it does
not persist beyond the I/O request that was paused for reconnecting; we
do not want it to fire in a drained section, because all sort of things
can happen in such a section (e.g. the AioContext might be changed, and
we do not want the timer to fire in the wrong context; or the BDS might
even be deleted, and so the timer CB would access already-freed data).

Signed-off-by: Hanna Reitz 
---
 block/nbd.c | 7 +++
 1 file changed, 7 insertions(+)

diff --git a/block/nbd.c b/block/nbd.c
index 63dbfa807d..16cd7fef77 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -381,6 +381,13 @@ static coroutine_fn void 
nbd_reconnect_attempt(BDRVNBDState *s)
 }
 
 nbd_co_do_establish_connection(s->bs, NULL);
+
+/*
+ * The reconnect attempt is done (maybe successfully, maybe not), so
+ * we no longer need this timer.  Delete it so it will not outlive
+ * this I/O request (so draining removes all timers).
+ */
+reconnect_delay_timer_del(s);
 }
 
 static coroutine_fn int nbd_receive_replies(BDRVNBDState *s, uint64_t handle)
-- 
2.34.1