[PATCH] mm/damon/reclaim: fix 'enabled' is incorrectly set because 'system_wq' is not initialized

From: Yuanzheng Song
Date: Fri Jul 15 2022 - 02:17:10 EST


The 'enabled' will be incorrectly set because the 'system_wq'
might not initialized yet. This results in 'enabled=true',
but the 'damon_reclaim_timer' is inactive. So fix it by moving
the judgment logic of the 'damon_reclaim_initialized' to the
start position of the enable_store().

Fixes: 294928293813 ("mm/damon/reclaim: schedule 'damon_reclaim_timer' only after 'system_wq' is initialized")
Signed-off-by: Yuanzheng Song <songyuanzheng@xxxxxxxxxx>
---
mm/damon/reclaim.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/mm/damon/reclaim.c b/mm/damon/reclaim.c
index e69b807fefe4..b13d5a02bf2e 100644
--- a/mm/damon/reclaim.c
+++ b/mm/damon/reclaim.c
@@ -374,13 +374,14 @@ static bool damon_reclaim_initialized;
static int damon_reclaim_enabled_store(const char *val,
const struct kernel_param *kp)
{
- int rc = param_set_bool(val, kp);
-
- if (rc < 0)
- return rc;
+ int rc;

/* system_wq might not initialized yet */
if (!damon_reclaim_initialized)
+ return -EINVAL;
+
+ rc = param_set_bool(val, kp);
+ if (rc < 0)
return rc;

schedule_delayed_work(&damon_reclaim_timer, 0);
--
2.25.1