1 files changed, 48 insertions, 20 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index f48693f75b37..932c26845e3e 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -429,11 +429,14 @@ static inline bool queue_pages_required(struct page *page,
 }
 
 /*
- * queue_pages_pmd() has three possible return values:
- * 1 - pages are placed on the right node or queued successfully.
- * 0 - THP was split.
- * -EIO - is migration entry or MPOL_MF_STRICT was specified and an existing
- *        page was already on a node that does not follow the policy.
+ * queue_pages_pmd() has four possible return values:
+ * 0 - pages are placed on the right node or queued successfully.
+ * 1 - there is unmovable page, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
+ *     specified.
+ * 2 - THP was split.
+ * -EIO - is migration entry or only MPOL_MF_STRICT was specified and an
+ *        existing page was already on a node that does not follow the
+ *        policy.
  */
 static int queue_pages_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr,
 				unsigned long end, struct mm_walk *walk)
@@ -451,19 +454,17 @@ static int queue_pages_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr,
 	if (is_huge_zero_page(page)) {
 		spin_unlock(ptl);
 		__split_huge_pmd(walk->vma, pmd, addr, false, NULL);
+		ret = 2;
 		goto out;
 	}
-	if (!queue_pages_required(page, qp)) {
-		ret = 1;
+	if (!queue_pages_required(page, qp))
 		goto unlock;
-	}
 
-	ret = 1;
 	flags = qp->flags;
 	/* go to thp migration */
 	if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
 		if (!vma_migratable(walk->vma)) {
-			ret = -EIO;
+			ret = 1;
 			goto unlock;
 		}
 
@@ -479,6 +480,13 @@ out:
 /*
  * Scan through pages checking if pages follow certain conditions,
  * and move them to the pagelist if they do.
+ *
+ * queue_pages_pte_range() has three possible return values:
+ * 0 - pages are placed on the right node or queued successfully.
+ * 1 - there is unmovable page, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
+ *     specified.
+ * -EIO - only MPOL_MF_STRICT was specified and an existing page was already
+ *        on a node that does not follow the policy.
  */
 static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
 			unsigned long end, struct mm_walk *walk)
@@ -488,17 +496,17 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
 	struct queue_pages *qp = walk->private;
 	unsigned long flags = qp->flags;
 	int ret;
+	bool has_unmovable = false;
 	pte_t *pte;
 	spinlock_t *ptl;
 
 	ptl = pmd_trans_huge_lock(pmd, vma);
 	if (ptl) {
 		ret = queue_pages_pmd(pmd, ptl, addr, end, walk);
-		if (ret > 0)
-			return 0;
-		else if (ret < 0)
+		if (ret != 2)
 			return ret;
 	}
+	/* THP was split, fall through to pte walk */
 
 	if (pmd_trans_unstable(pmd))
 		return 0;
@@ -519,14 +527,21 @@ static int queue_pages_pte_range(pmd_t *pmd, unsigned long addr,
 		if (!queue_pages_required(page, qp))
 			continue;
 		if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
-			if (!vma_migratable(vma))
+			/* MPOL_MF_STRICT must be specified if we get here */
+			if (!vma_migratable(vma)) {
+				has_unmovable = true;
 				break;
+			}
 			migrate_page_add(page, qp->pagelist, flags);
 		} else
 			break;
 	}
 	pte_unmap_unlock(pte - 1, ptl);
 	cond_resched();
+
+	if (has_unmovable)
+		return 1;
+
 	return addr != end ? -EIO : 0;
 }
 
@@ -639,7 +654,13 @@ static int queue_pages_test_walk(unsigned long start, unsigned long end,
  *
  * If pages found in a given range are on a set of nodes (determined by
  * @nodes and @flags,) it's isolated and queued to the pagelist which is
- * passed via @private.)
+ * passed via @private.
+ *
+ * queue_pages_range() has three possible return values:
+ * 1 - there is unmovable page, but MPOL_MF_MOVE* & MPOL_MF_STRICT were
+ *     specified.
+ * 0 - queue pages successfully or no misplaced page.
+ * -EIO - there is misplaced page and only MPOL_MF_STRICT was specified.
  */
 static int
 queue_pages_range(struct mm_struct *mm, unsigned long start, unsigned long end,
@@ -1182,6 +1203,7 @@ static long do_mbind(unsigned long start, unsigned long len,
 	struct mempolicy *new;
 	unsigned long end;
 	int err;
+	int ret;
 	LIST_HEAD(pagelist);
 
 	if (flags & ~(unsigned long)MPOL_MF_VALID)
@@ -1243,10 +1265,15 @@ static long do_mbind(unsigned long start, unsigned long len,
 	if (err)
 		goto mpol_out;
 
-	err = queue_pages_range(mm, start, end, nmask,
+	ret = queue_pages_range(mm, start, end, nmask,
 			  flags | MPOL_MF_INVERT, &pagelist);
-	if (!err)
-		err = mbind_range(mm, start, end, new);
+
+	if (ret < 0) {
+		err = -EIO;
+		goto up_out;
+	}
+
+	err = mbind_range(mm, start, end, new);
 
 	if (!err) {
 		int nr_failed = 0;
@@ -1259,13 +1286,14 @@ static long do_mbind(unsigned long start, unsigned long len,
 				putback_movable_pages(&pagelist);
 		}
 
-		if (nr_failed && (flags & MPOL_MF_STRICT))
+		if ((ret > 0) || (nr_failed && (flags & MPOL_MF_STRICT)))
 			err = -EIO;
 	} else
 		putback_movable_pages(&pagelist);
 
+up_out:
 	up_write(&mm->mmap_sem);
- mpol_out:
+mpol_out:
 	mpol_put(new);
 	return err;
 }