mm: rename alloc_demote_folio to alloc_migrate_folio

The alloc_demote_folio can also be used for general migration including
both demotion and promotion so it'd be better to rename it from
alloc_demote_folio to alloc_migrate_folio.

Link: https://lkml.kernel.org/r/[e-mail]
Signed-off-by: Honggyu Kim <[e-mail]>
Reviewed-by: SeongJae Park <[e-mail]>
Cc: Gregory Price <[e-mail]>
Cc: Hyeonggon Yoo <[e-mail]>
Cc: Hyeongtak Ji <[e-mail]>
Cc: Masami Hiramatsu (Google) <[e-mail]>
Cc: Mathieu Desnoyers <[e-mail]>
Cc: Rakie Kim <[e-mail]>
Cc: Steven Rostedt (Google) <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

mm/internal.h

···
         unsigned long, unsigned long);
 
 extern void set_pageblock_order(void);
-struct folio *alloc_demote_folio(struct folio *src, unsigned long private);
+struct folio *alloc_migrate_folio(struct folio *src, unsigned long private);
 unsigned long reclaim_pages(struct list_head *folio_list);
 unsigned int reclaim_clean_pages_from_list(struct zone *zone,
 					    struct list_head *folio_list);

mm/vmscan.c

···
 		mapping->a_ops->is_dirty_writeback(folio, dirty, writeback);
 }
 
-struct folio *alloc_demote_folio(struct folio *src, unsigned long private)
+struct folio *alloc_migrate_folio(struct folio *src, unsigned long private)
 {
 	struct folio *dst;
 	nodemask_t *allowed_mask;
···
 	node_get_allowed_targets(pgdat, &allowed_mask);
 
 	/* Demotion ignores all cpuset and mempolicy settings */
-	migrate_pages(demote_folios, alloc_demote_folio, NULL,
+	migrate_pages(demote_folios, alloc_migrate_folio, NULL,
 		      (unsigned long)&mtc, MIGRATE_ASYNC, MR_DEMOTION,
 		      &nr_succeeded);