1 files changed, 10 insertions, 19 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 69284d3b5e53..a2516d31db6c 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -786,7 +786,6 @@ static int vma_replace_policy(struct vm_area_struct *vma,
 static int mbind_range(struct mm_struct *mm, unsigned long start,
 		       unsigned long end, struct mempolicy *new_pol)
 {
-	struct vm_area_struct *next;
 	struct vm_area_struct *prev;
 	struct vm_area_struct *vma;
 	int err = 0;
@@ -801,8 +800,7 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
 	if (start > vma->vm_start)
 		prev = vma;
 
-	for (; vma && vma->vm_start < end; prev = vma, vma = next) {
-		next = vma->vm_next;
+	for (; vma && vma->vm_start < end; prev = vma, vma = vma->vm_next) {
 		vmstart = max(start, vma->vm_start);
 		vmend   = min(end, vma->vm_end);
 
@@ -817,10 +815,6 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
 				 anon_vma_name(vma));
 		if (prev) {
 			vma = prev;
-			next = vma->vm_next;
-			if (mpol_equal(vma_policy(vma), new_pol))
-				continue;
-			/* vma_merge() joined vma && vma->next, case 8 */
 			goto replace;
 		}
 		if (vma->vm_start != vmstart) {
@@ -907,17 +901,14 @@ static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
 static int lookup_node(struct mm_struct *mm, unsigned long addr)
 {
 	struct page *p = NULL;
-	int err;
+	int ret;
 
-	int locked = 1;
-	err = get_user_pages_locked(addr & PAGE_MASK, 1, 0, &p, &locked);
-	if (err > 0) {
-		err = page_to_nid(p);
+	ret = get_user_pages_fast(addr & PAGE_MASK, 1, 0, &p);
+	if (ret > 0) {
+		ret = page_to_nid(p);
 		put_page(p);
 	}
-	if (locked)
-		mmap_read_unlock(mm);
-	return err;
+	return ret;
 }
 
 /* Retrieve NUMA policy */
@@ -968,14 +959,14 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
 	if (flags & MPOL_F_NODE) {
 		if (flags & MPOL_F_ADDR) {
 			/*
-			 * Take a refcount on the mpol, lookup_node()
-			 * will drop the mmap_lock, so after calling
-			 * lookup_node() only "pol" remains valid, "vma"
-			 * is stale.
+			 * Take a refcount on the mpol, because we are about to
+			 * drop the mmap_lock, after which only "pol" remains
+			 * valid, "vma" is stale.
 			 */
 			pol_refcount = pol;
 			vma = NULL;
 			mpol_get(pol);
+			mmap_read_unlock(mm);
 			err = lookup_node(mm, addr);
 			if (err < 0)
 				goto out;