[PATCH] mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro

[Jakov Novak]

Currently, khugepaged locks the khugepaged_mutex in two functions:
start_stop_khugepaged and khugepaged_min_free_kbytes_update. Remove
mutex_lock/mutex_unlock usage in these functions and replace it with the
guard macro. This makes the code more readable (removing a goto statement)
and makes it harder to introduce bugs in the future.
No functional changes introduced.

Signed-off-by: Jakov Novak <jakovnovak30@xxxxxxxxx>
---
 mm/khugepaged.c | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 617bca76db49..c583867f2e7a 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -3113,7 +3113,7 @@ int start_stop_khugepaged(void)
 {
 	int err = 0;
 
-	mutex_lock(&khugepaged_mutex);
+	guard(mutex)(&khugepaged_mutex);
 	if (hugepage_enabled()) {
 		if (!khugepaged_thread)
 			khugepaged_thread = kthread_run(khugepaged, NULL,
@@ -3122,7 +3122,7 @@ int start_stop_khugepaged(void)
 			pr_err("khugepaged: kthread_run(khugepaged) failed\n");
 			err = PTR_ERR(khugepaged_thread);
 			khugepaged_thread = NULL;
-			goto fail;
+			return err;
 		}
 
 		if (!list_empty(&khugepaged_scan.mm_head))
@@ -3132,17 +3132,14 @@ int start_stop_khugepaged(void)
 		khugepaged_thread = NULL;
 	}
 	set_recommended_min_free_kbytes();
-fail:
-	mutex_unlock(&khugepaged_mutex);
 	return err;
 }
 
 void khugepaged_min_free_kbytes_update(void)
 {
-	mutex_lock(&khugepaged_mutex);
+	guard(mutex)(&khugepaged_mutex);
 	if (hugepage_enabled() && khugepaged_thread)
 		set_recommended_min_free_kbytes();
-	mutex_unlock(&khugepaged_mutex);
 }
 
 bool current_is_khugepaged(void)
-- 
2.55.0