Revert "mm/page_isolation: unset migratetype directly for non Buddy page"

This reverts commit 721fb89.

Commit 721fb89 ("mm/page_isolation: unset migratetype directly for
non Buddy page") will result memory that should in buddy disappear by
mistake.  move_freepages_block moves all pages in pageblock instead of
pages indicated by input parameter, so if input pages is not in buddy
but other pages in pageblock is in buddy, it will result in page out of
control.

Link: https://lkml.kernel.org/r/[email protected]
Fixes: 721fb89 ("mm/page_isolation: unset migratetype directly for non Buddy page")
Signed-off-by: Chen Wandun <[email protected]>
Reported-by: "kernelci.org bot" <[email protected]>
Acked-by: David Hildenbrand <[email protected]>
Tested-by: Dong Aisheng <[email protected]>
Tested-by: Francesco Dolcini <[email protected]>
Acked-by: Vlastimil Babka <[email protected]>
Tested-by: Guenter Roeck <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Author: Chen Wandun

mm/page_isolation.c

@@ -115,7 +115,7 @@ static void unset_migratetype_isolate(struct page *page, unsigned migratetype)
 	 * onlining - just onlined memory won't immediately be considered for
 	 * allocation.
 	 */
-	if (!isolated_page && PageBuddy(page)) {
+	if (!isolated_page) {
 		nr_pages = move_freepages_block(zone, page, migratetype, NULL);
 		__mod_zone_freepage_state(zone, nr_pages, migratetype);
 	}