[PATCH 1/2] mm: thp: Return the correct value for change_huge_pmd

[Mel Gorman <mgorman@xxxxxxx>]

The wrong value is being returned by change_huge_pmd since commit
10c1045f28e8 ("mm: numa: avoid unnecessary TLB flushes when setting
NUMA hinting entries") which allows a fallthrough that tries to adjust
non-existent PTEs. This patch corrects it.

Signed-off-by: Mel Gorman <mgorman@xxxxxxx>
---
 mm/huge_memory.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index fc00c8cb5a82..194c0f019774 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1482,6 +1482,7 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t 
*pmd,
 
        if (__pmd_trans_huge_lock(pmd, vma, &ptl) == 1) {
                pmd_t entry;
+               ret = 1;
 
                /*
                 * Avoid trapping faults against the zero page. The read-only
@@ -1490,11 +1491,10 @@ int change_huge_pmd(struct vm_area_struct *vma, pmd_t 
*pmd,
                 */
                if (prot_numa && is_huge_zero_pmd(*pmd)) {
                        spin_unlock(ptl);
-                       return 0;
+                       return ret;
                }
 
                if (!prot_numa || !pmd_protnone(*pmd)) {
-                       ret = 1;
                        entry = pmdp_get_and_clear_notify(mm, addr, pmd);
                        entry = pmd_modify(entry, newprot);
                        ret = HPAGE_PMD_NR;
-- 
2.1.2