From eeb4683ad8c40a03a4e91463ec1d1b651974b744 Mon Sep 17 00:00:00 2001
From: Hanna Reitz <hreitz@redhat.com>
Date: Fri, 4 Feb 2022 12:10:06 +0100
Subject: [PATCH 3/8] block/nbd: Delete reconnect delay timer when done

RH-Author: Hanna Reitz <hreitz@redhat.com>
RH-MergeRequest: 74: block/nbd: Handle AioContext changes
RH-Commit: [1/6] 34f92910b6ffd256d781109a2b39737fc6ab449c (hreitz/qemu-kvm-c-9-s)
RH-Bugzilla: 2033626
RH-Acked-by: Miroslav Rezanina <mrezanin@redhat.com>
RH-Acked-by: Eric Blake <eblake@redhat.com>
RH-Acked-by: Stefan Hajnoczi <stefanha@redhat.com>

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).

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
(cherry picked from commit 3ce1fc16bad9c3f8b7b10b451a224d6d76e5c551)
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
---
 block/nbd.c | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/block/nbd.c b/block/nbd.c
index 5ef462db1b..b8e5a9b4cc 100644
--- a/block/nbd.c
+++ b/block/nbd.c
@@ -353,6 +353,13 @@ 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)
-- 
2.27.0