[PATCH] mm/migrate: fix pmd_migration_entry_wait() (merge issue in linux-next)

[Dan Carpenter <dan.carpenter@xxxxxxxxxx>]

The "ptl = pmd_lock(mm, pmd);" line was accidentally deleted in the
linux-next merge for next-20211214.

Fixes: fd93c9fe58cc ("Merge branch 'akpm-current/current'")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
---
 mm/migrate.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/mm/migrate.c b/mm/migrate.c
index 8d93dfb0b9e1..c9296d63878d 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -339,6 +339,8 @@ void pmd_migration_entry_wait(struct mm_struct *mm, pmd_t *pmd)
 {
 	spinlock_t *ptl;
 	struct folio *folio;
+
+	ptl = pmd_lock(mm, pmd);
 	if (!is_pmd_migration_entry(*pmd))
 		goto unlock;
 	folio = page_folio(pfn_swap_entry_to_page(pmd_to_swp_entry(*pmd)));
-- 
2.20.1