mm: thp: Return the correct value for change_huge_pmd

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@suse.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 89b9075f8c11..626e93db28ba 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -1487,6 +1487,7 @@ 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
@@ -1495,11 +1496,10 @@ 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;