mm/memory: fix folio_set_dirty() vs. folio_mark_dirty() in zap_pte_range()

The correct folio replacement for "set_page_dirty()" is
"folio_mark_dirty()", not "folio_set_dirty()".  Using the latter won't
properly inform the FS using the dirty_folio() callback.

This has been found by code inspection, but likely this can result in some
real trouble when zapping dirty PTEs that point at clean pagecache folios.

Yuezhang Mo said: "Without this fix, testing the latest exfat with
xfstests, test cases generic/029 and generic/030 will fail."

Link: https://lkml.kernel.org/r/[email protected]
Fixes: c462650 ("mm/memory: page_remove_rmap() -> folio_remove_rmap_pte()")
Signed-off-by: David Hildenbrand <[email protected]>
Reported-by: Ryan Roberts <[email protected]>
Closes: https://lkml.kernel.org/r/[email protected]
Reviewed-by: Ryan Roberts <[email protected]>
Cc: Matthew Wilcox (Oracle) <[email protected]>
Reviewed-by: Yuezhang Mo <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

Author: davidhildenbrand

mm/memory.c

@@ -1464,7 +1464,7 @@ static unsigned long zap_pte_range(struct mmu_gather *tlb,
 			delay_rmap = 0;
 			if (!folio_test_anon(folio)) {
 				if (pte_dirty(ptent)) {
-					folio_set_dirty(folio);
+					folio_mark_dirty(folio);
 					if (tlb_delay_rmap(tlb)) {
 						delay_rmap = 1;
 						force_flush = 1;