Merge tag 'v3.2.32' into v3.2-rt

This is the 3.2.32 stable release

4 files changed, 81 insertions, 45 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index 0f897b89bbc4..d6c0fdfd8027 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2429,8 +2429,8 @@ static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
 	 * from page cache lookup which is in HPAGE_SIZE units.
 	 */
 	address = address & huge_page_mask(h);
-	pgoff = ((address - vma->vm_start) >> PAGE_SHIFT)
-		+ (vma->vm_pgoff >> PAGE_SHIFT);
+	pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) +
+			vma->vm_pgoff;
 	mapping = vma->vm_file->f_dentry->d_inode->i_mapping;
 
 	/*
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 11b8d47dc6c1..4c82c2135bf0 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -607,24 +607,39 @@ check_range(struct mm_struct *mm, unsigned long start, unsigned long end,
 	return first;
 }
 
-/* Apply policy to a single VMA */
-static int policy_vma(struct vm_area_struct *vma, struct mempolicy *new)
+/*
+ * Apply policy to a single VMA
+ * This must be called with the mmap_sem held for writing.
+ */
+static int vma_replace_policy(struct vm_area_struct *vma,
+						struct mempolicy *pol)
 {
-	int err = 0;
-	struct mempolicy *old = vma->vm_policy;
+	int err;
+	struct mempolicy *old;
+	struct mempolicy *new;
 
 	pr_debug("vma %lx-%lx/%lx vm_ops %p vm_file %p set_policy %p\n",
 		 vma->vm_start, vma->vm_end, vma->vm_pgoff,
 		 vma->vm_ops, vma->vm_file,
 		 vma->vm_ops ? vma->vm_ops->set_policy : NULL);
 
-	if (vma->vm_ops && vma->vm_ops->set_policy)
+	new = mpol_dup(pol);
+	if (IS_ERR(new))
+		return PTR_ERR(new);
+
+	if (vma->vm_ops && vma->vm_ops->set_policy) {
 		err = vma->vm_ops->set_policy(vma, new);
-	if (!err) {
-		mpol_get(new);
-		vma->vm_policy = new;
-		mpol_put(old);
+		if (err)
+			goto err_out;
 	}
+
+	old = vma->vm_policy;
+	vma->vm_policy = new; /* protected by mmap_sem */
+	mpol_put(old);
+
+	return 0;
+ err_out:
+	mpol_put(new);
 	return err;
 }
 
@@ -675,7 +690,7 @@ static int mbind_range(struct mm_struct *mm, unsigned long start,
 			if (err)
 				goto out;
 		}
-		err = policy_vma(vma, new_pol);
+		err = vma_replace_policy(vma, new_pol);
 		if (err)
 			goto out;
 	}
@@ -1507,8 +1522,18 @@ struct mempolicy *get_vma_policy(struct task_struct *task,
 									addr);
 			if (vpol)
 				pol = vpol;
-		} else if (vma->vm_policy)
+		} else if (vma->vm_policy) {
 			pol = vma->vm_policy;
+
+			/*
+			 * shmem_alloc_page() passes MPOL_F_SHARED policy with
+			 * a pseudo vma whose vma->vm_ops=NULL. Take a reference
+			 * count on these policies which will be dropped by
+			 * mpol_cond_put() later
+			 */
+			if (mpol_needs_cond_ref(pol))
+				mpol_get(pol);
+		}
 	}
 	if (!pol)
 		pol = &default_policy;
@@ -2032,7 +2057,7 @@ int __mpol_equal(struct mempolicy *a, struct mempolicy *b)
  */
 
 /* lookup first element intersecting start-end */
-/* Caller holds sp->lock */
+/* Caller holds sp->mutex */
 static struct sp_node *
 sp_lookup(struct shared_policy *sp, unsigned long start, unsigned long end)
 {
@@ -2096,36 +2121,50 @@ mpol_shared_policy_lookup(struct shared_policy *sp, unsigned long idx)
 
 	if (!sp->root.rb_node)
 		return NULL;
-	spin_lock(&sp->lock);
+	mutex_lock(&sp->mutex);
 	sn = sp_lookup(sp, idx, idx+1);
 	if (sn) {
 		mpol_get(sn->policy);
 		pol = sn->policy;
 	}
-	spin_unlock(&sp->lock);
+	mutex_unlock(&sp->mutex);
 	return pol;
 }
 
+static void sp_free(struct sp_node *n)
+{
+	mpol_put(n->policy);
+	kmem_cache_free(sn_cache, n);
+}
+
 static void sp_delete(struct shared_policy *sp, struct sp_node *n)
 {
 	pr_debug("deleting %lx-l%lx\n", n->start, n->end);
 	rb_erase(&n->nd, &sp->root);
-	mpol_put(n->policy);
-	kmem_cache_free(sn_cache, n);
+	sp_free(n);
 }
 
 static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
 				struct mempolicy *pol)
 {
-	struct sp_node *n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
+	struct sp_node *n;
+	struct mempolicy *newpol;
 
+	n = kmem_cache_alloc(sn_cache, GFP_KERNEL);
 	if (!n)
 		return NULL;
+
+	newpol = mpol_dup(pol);
+	if (IS_ERR(newpol)) {
+		kmem_cache_free(sn_cache, n);
+		return NULL;
+	}
+	newpol->flags |= MPOL_F_SHARED;
+
 	n->start = start;
 	n->end = end;
-	mpol_get(pol);
-	pol->flags |= MPOL_F_SHARED;	/* for unref */
-	n->policy = pol;
+	n->policy = newpol;
+
 	return n;
 }
 
@@ -2133,10 +2172,10 @@ static struct sp_node *sp_alloc(unsigned long start, unsigned long end,
 static int shared_policy_replace(struct shared_policy *sp, unsigned long start,
 				 unsigned long end, struct sp_node *new)
 {
-	struct sp_node *n, *new2 = NULL;
+	struct sp_node *n;
+	int ret = 0;
 
-restart:
-	spin_lock(&sp->lock);
+	mutex_lock(&sp->mutex);
 	n = sp_lookup(sp, start, end);
 	/* Take care of old policies in the same range. */
 	while (n && n->start < end) {
@@ -2149,16 +2188,14 @@ restart:
 		} else {
 			/* Old policy spanning whole new range. */
 			if (n->end > end) {
+				struct sp_node *new2;
+				new2 = sp_alloc(end, n->end, n->policy);
 				if (!new2) {
-					spin_unlock(&sp->lock);
-					new2 = sp_alloc(end, n->end, n->policy);
-					if (!new2)
-						return -ENOMEM;
-					goto restart;
+					ret = -ENOMEM;
+					goto out;
 				}
 				n->end = start;
 				sp_insert(sp, new2);
-				new2 = NULL;
 				break;
 			} else
 				n->end = start;
@@ -2169,12 +2206,9 @@ restart:
 	}
 	if (new)
 		sp_insert(sp, new);
-	spin_unlock(&sp->lock);
-	if (new2) {
-		mpol_put(new2->policy);
-		kmem_cache_free(sn_cache, new2);
-	}
-	return 0;
+out:
+	mutex_unlock(&sp->mutex);
+	return ret;
 }
 
 /**
@@ -2192,7 +2226,7 @@ void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol)
 	int ret;
 
 	sp->root = RB_ROOT;		/* empty tree == default mempolicy */
-	spin_lock_init(&sp->lock);
+	mutex_init(&sp->mutex);
 
 	if (mpol) {
 		struct vm_area_struct pvma;
@@ -2246,7 +2280,7 @@ int mpol_set_shared_policy(struct shared_policy *info,
 	}
 	err = shared_policy_replace(info, vma->vm_pgoff, vma->vm_pgoff+sz, new);
 	if (err && new)
-		kmem_cache_free(sn_cache, new);
+		sp_free(new);
 	return err;
 }
 
@@ -2258,16 +2292,14 @@ void mpol_free_shared_policy(struct shared_policy *p)
 
 	if (!p->root.rb_node)
 		return;
-	spin_lock(&p->lock);
+	mutex_lock(&p->mutex);
 	next = rb_first(&p->root);
 	while (next) {
 		n = rb_entry(next, struct sp_node, nd);
 		next = rb_next(&n->nd);
-		rb_erase(&n->nd, &p->root);
-		mpol_put(n->policy);
-		kmem_cache_free(sn_cache, n);
+		sp_delete(p, n);
 	}
-	spin_unlock(&p->lock);
+	mutex_unlock(&p->mutex);
 }
 
 /* assumes fs == KERNEL_DS */
diff --git a/mm/slab.c b/mm/slab.c
index 6a8fd1bbe1c0..81d3481b7eb3 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1753,6 +1753,9 @@ void __init kmem_cache_init_late(void)
 	}
 	mutex_unlock(&cache_chain_mutex);
 
+	/* Annotate slab for lockdep -- annotate the malloc caches */
+	init_lock_keys();
+
 	/* Done! */
 	g_cpucache_up = FULL;
 
diff --git a/mm/truncate.c b/mm/truncate.c
index 632b15e29f74..00fb58a271a8 100644
--- a/mm/truncate.c
+++ b/mm/truncate.c
@@ -394,11 +394,12 @@ invalidate_complete_page2(struct address_space *mapping, struct page *page)
 	if (page_has_private(page) && !try_to_release_page(page, GFP_KERNEL))
 		return 0;
 
+	clear_page_mlock(page);
+
 	spin_lock_irq(&mapping->tree_lock);
 	if (PageDirty(page))
 		goto failed;
 
-	clear_page_mlock(page);
 	BUG_ON(page_has_private(page));
 	__delete_from_page_cache(page);
 	spin_unlock_irq(&mapping->tree_lock);