[PATCH RFC 01/13] mm/rmap: fix missing swap_free() in try_to_unmap() after arch_unmap_one() failed

[David Hildenbrand <david@redhat.com>]

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")
Cc: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 mm/rmap.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/mm/rmap.c b/mm/rmap.c
index 6a1e8c7f6213..f825aeef61ca 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1625,6 +1625,7 @@ static bool try_to_unmap_one(struct page *page, 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);
-- 
2.35.1