From 79ebda933edbfdc26735f942de3c0c0739733644 Mon Sep 17 00:00:00 2001
From: Vitaliy Filippov <vitalif@yourcmc.ru>
Date: Mon, 28 Mar 2022 01:42:06 +0300
Subject: [PATCH] Fix a write hang with throttling due to timer reenterability
 / triggerability

---
 src/blockstore_write.cpp | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/blockstore_write.cpp b/src/blockstore_write.cpp
index 8915f422..916118dd 100644
--- a/src/blockstore_write.cpp
+++ b/src/blockstore_write.cpp
@@ -544,12 +544,13 @@ resume_4:
             if (ref_us > exec_us + throttle_threshold_us)
             {
                 // Pause reply
+                PRIV(op)->op_state = 5;
+                // Remember that the timer can in theory be called right here
                 tfd->set_timer_us(ref_us-exec_us, false, [this, op](int timer_id)
                 {
                     PRIV(op)->op_state++;
                     ringloop->wakeup();
                 });
-                PRIV(op)->op_state = 5;
                 return 1;
             }
         }