1 files changed, 35 insertions, 15 deletions

diff --git a/mm/pagewalk.c b/mm/pagewalk.c
index ea0b9e606ad1..690af44609e2 100644
--- a/mm/pagewalk.c
+++ b/mm/pagewalk.c
@@ -46,6 +46,9 @@ again:
 				break;
 			continue;
 		}
+
+		walk->action = ACTION_SUBTREE;
+
 		/*
 		 * This implies that each ->pmd_entry() handler
 		 * needs to know about pmd_trans_huge() pmds
@@ -55,16 +58,21 @@ again:
 		if (err)
 			break;
 
+		if (walk->action == ACTION_AGAIN)
+			goto again;
+
 		/*
 		 * Check this here so we only break down trans_huge
 		 * pages when we _need_ to
 		 */
-		if (!ops->pte_entry)
+		if (walk->action == ACTION_CONTINUE ||
+		    !(ops->pte_entry))
 			continue;
 
 		split_huge_pmd(walk->vma, pmd, addr);
 		if (pmd_trans_unstable(pmd))
 			goto again;
+
 		err = walk_pte_range(pmd, addr, next, walk);
 		if (err)
 			break;
@@ -93,24 +101,25 @@ static int walk_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
 			continue;
 		}
 
-		if (ops->pud_entry) {
-			spinlock_t *ptl = pud_trans_huge_lock(pud, walk->vma);
+		walk->action = ACTION_SUBTREE;
 
-			if (ptl) {
-				err = ops->pud_entry(pud, addr, next, walk);
-				spin_unlock(ptl);
-				if (err)
-					break;
-				continue;
-			}
-		}
+		if (ops->pud_entry)
+			err = ops->pud_entry(pud, addr, next, walk);
+		if (err)
+			break;
+
+		if (walk->action == ACTION_AGAIN)
+			goto again;
+
+		if (walk->action == ACTION_CONTINUE ||
+		    !(ops->pmd_entry || ops->pte_entry))
+			continue;
 
 		split_huge_pud(walk->vma, pud, addr);
 		if (pud_none(*pud))
 			goto again;
 
-		if (ops->pmd_entry || ops->pte_entry)
-			err = walk_pmd_range(pud, addr, next, walk);
+		err = walk_pmd_range(pud, addr, next, walk);
 		if (err)
 			break;
 	} while (pud++, addr = next, addr != end);
@@ -136,7 +145,12 @@ static int walk_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
 				break;
 			continue;
 		}
-		if (ops->pmd_entry || ops->pte_entry)
+		if (ops->p4d_entry) {
+			err = ops->p4d_entry(p4d, addr, next, walk);
+			if (err)
+				break;
+		}
+		if (ops->pud_entry || ops->pmd_entry || ops->pte_entry)
 			err = walk_pud_range(p4d, addr, next, walk);
 		if (err)
 			break;
@@ -163,7 +177,13 @@ static int walk_pgd_range(unsigned long addr, unsigned long end,
 				break;
 			continue;
 		}
-		if (ops->pmd_entry || ops->pte_entry)
+		if (ops->pgd_entry) {
+			err = ops->pgd_entry(pgd, addr, next, walk);
+			if (err)
+				break;
+		}
+		if (ops->p4d_entry || ops->pud_entry || ops->pmd_entry ||
+		    ops->pte_entry)
 			err = walk_p4d_range(pgd, addr, next, walk);
 		if (err)
 			break;