[PATCH v3 3/8] mm: use zone lock guard in unreserve_highatomic_pageblock()

[Dmitry Ilvokhin]

Use spinlock_irqsave zone lock guard in unreserve_highatomic_pageblock()
to replace the explicit lock/unlock pattern with automatic scope-based
cleanup.

Suggested-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
Signed-off-by: Dmitry Ilvokhin <d@xxxxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
---
 mm/page_alloc.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 14c172c9b6c6..2f4170ae60f5 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3478,7 +3478,6 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
 						bool force)
 {
 	struct zonelist *zonelist = ac->zonelist;
-	unsigned long flags;
 	struct zoneref *z;
 	struct zone *zone;
 	struct page *page;
@@ -3495,7 +3494,7 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
 					pageblock_nr_pages)
 			continue;
 
-		spin_lock_irqsave(&zone->lock, flags);
+		guard(spinlock_irqsave)(&zone->lock);
 		for (order = 0; order < NR_PAGE_ORDERS; order++) {
 			struct free_area *area = &(zone->free_area[order]);
 			unsigned long size;
@@ -3542,12 +3541,9 @@ static bool unreserve_highatomic_pageblock(const struct alloc_context *ac,
 			 * so this should not fail on zone boundaries.
 			 */
 			WARN_ON_ONCE(ret == -1);
-			if (ret > 0) {
-				spin_unlock_irqrestore(&zone->lock, flags);
+			if (ret > 0)
 				return ret;
-			}
 		}
-		spin_unlock_irqrestore(&zone->lock, flags);
 	}
 
 	return false;
-- 
2.52.0