[v4,01/17] mm/rmap: fix missing swap_free() in try_to_unmap() after arch_unmap_one() failed

Commit Message

David Hildenbrand April 28, 2022, 8:34 a.m. UTC

In case arch_unmap_one() fails, we already did a swap_duplicate(). let's
undo that properly via swap_free().

Fixes: ca827d55ebaa ("mm, swap: Add infrastructure for saving page metadata on swap")
Reviewed-by: Khalid Aziz <[e-mail]>
Acked-by: Vlastimil Babka <[e-mail]>
Signed-off-by: David Hildenbrand <[e-mail]>
---
 mm/rmap.c | 1 +
 1 file changed, 1 insertion(+)

Patch

diff --git a/mm/rmap.c b/mm/rmap.c
index fedb82371efe..eb246fc8b089 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1637,6 +1637,7 @@  static bool try_to_unmap_one(struct folio *folio, struct vm_area_struct *vma,
 				break;
 			}
 			if (arch_unmap_one(mm, vma, address, pteval) < 0) {
+				swap_free(entry);
 				set_pte_at(mm, address, pvmw.pte, pteval);
 				ret = false;
 				page_vma_mapped_walk_done(&pvmw);