mm: vmscan: move set_task_reclaim_state() near flush_reclaim_state()

Move set_task_reclaim_state() near flush_reclaim_state() so that all
helpers manipulating reclaim_state are in close proximity.

Link: https://lkml.kernel.org/r/20230413104034.1086717-3-yosryahmed@google.comSigned-off-by: Yosry Ahmed <yosryahmed@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Lameter <cl@linux.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Peter Xu <peterx@redhat.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Tim Chen <tim.c.chen@linux.intel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

mm/vmscan.c

@@ -189,18 +189,6 @@ struct scan_control {
  */
 int vm_swappiness = 60;
 
-static void set_task_reclaim_state(struct task_struct *task,
-				   struct reclaim_state *rs)
-{
-	/* Check for an overwrite */
-	WARN_ON_ONCE(rs && task->reclaim_state);
-
-	/* Check for the nulling of an already-nulled member */
-	WARN_ON_ONCE(!rs && !task->reclaim_state);
-
-	task->reclaim_state = rs;
-}
-
 LIST_HEAD(shrinker_list);
 DEFINE_MUTEX(shrinker_mutex);
 DEFINE_SRCU(shrinker_srcu);
@@ -528,6 +516,18 @@ static bool writeback_throttling_sane(struct scan_control *sc)
 }
 #endif
 
+static void set_task_reclaim_state(struct task_struct *task,
+				   struct reclaim_state *rs)
+{
+	/* Check for an overwrite */
+	WARN_ON_ONCE(rs && task->reclaim_state);
+
+	/* Check for the nulling of an already-nulled member */
+	WARN_ON_ONCE(!rs && !task->reclaim_state);
+
+	task->reclaim_state = rs;
+}
+
 /*
  * flush_reclaim_state(): add pages reclaimed outside of LRU-based reclaim to
  * scan_control->nr_reclaimed.