[PATCH v2 6/7] mm/khugepaged: unmap pte before releasing vma write lock

[Nico Pache]

We are currently dropping the anon_vma write lock before unmapping the
PTE. Although this is safe, due to us still holding the mmap_write_lock,
its safer and less confusing to switch the order of these two operations.

Suggested-by: David Hildenbrand <david@xxxxxxxxxx>
Signed-off-by: Nico Pache <npache@xxxxxxxxxx>
---
 mm/khugepaged.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/khugepaged.c b/mm/khugepaged.c
index 655dbc90535a..40125dcb4de9 100644
--- a/mm/khugepaged.c
+++ b/mm/khugepaged.c
@@ -1546,10 +1546,10 @@ static enum scan_result collapse_huge_page(struct mm_struct *mm, unsigned long s
 
 	result = SCAN_SUCCEED;
 out_up_write:
-	if (anon_vma_locked)
-		anon_vma_unlock_write(vma->anon_vma);
 	if (pte)
 		pte_unmap(pte);
+	if (anon_vma_locked)
+		anon_vma_unlock_write(vma->anon_vma);
 	mmap_write_unlock(mm);
 out_nolock:
 	if (folio)
-- 
2.54.0