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

David Hildenbrand
2022-04-28T08:38:21Z

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 <khalid.aziz@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
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 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);
--
2.35.1