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

This reverts commit 721fb891.

Commit 721fb891 ("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/20220126024436.13921-1-chenwandun@huawei.com
Fixes: 721fb891 ("mm/page_isolation: unset migratetype directly for non Buddy page")
Signed-off-by: NChen Wandun <chenwandun@huawei.com>
Reported-by: N"kernelci.org bot" <bot@kernelci.org>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Tested-by: NDong Aisheng <aisheng.dong@nxp.com>
Tested-by: NFrancesco Dolcini <francesco.dolcini@toradex.com>
Acked-by: NVlastimil Babka <vbabka@suse.cz>
Tested-by: NGuenter Roeck <linux@roeck-us.net>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

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);
 	}