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/20240122171751.272074-1-david@redhat.com
Fixes: c46265030b0f ("mm/memory: page_remove_rmap() -> folio_remove_rmap_pte()")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: Ryan Roberts <ryan.roberts@arm.com>
Closes: https://lkml.kernel.org/r/2445cedb-61fb-422c-8bfb-caf0a2beed62@arm.com
Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Yuezhang Mo <Yuezhang.Mo@sony.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/mm/memory.c b/mm/memory.c
index 7e1f4849463aa3645a0eead97f40a90caf5e6d5f..89bcae0b224d6d43b4720c5c71a6c528e683bafb 100644 (file)
--- a/mm/memory.c
+++ b/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;