Atomically check and set dropped zevent count

ratelimit_dropped isn't protected by a lock and is expected to be updated atomically. Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov> Signed-off-by: Ryan Moeller <ryan@iXsystems.com> Closes openzfs#11822
truenas · May 6, 2021 · 2ca4c2e · 2ca4c2e
1 parent 3edbb09
commit 2ca4c2e
Showing 1 changed file with 1 addition and 2 deletions.
diff --git a/module/zfs/fm.c b/module/zfs/fm.c
@@ -658,8 +658,7 @@ zfs_zevent_next(zfs_zevent_t *ze, nvlist_t **event, uint64_t *event_size,
 
 #ifdef _KERNEL
 	/* Include events dropped due to rate limiting */
-	*dropped += ratelimit_dropped;
-	ratelimit_dropped = 0;
+	*dropped += atomic_swap_64(&ratelimit_dropped, 0);
 #endif
 	ze->ze_dropped = 0;
 out: