Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "190 patches.

  Subsystems affected by this patch series: mm (hugetlb, userfaultfd,
  vmscan, kconfig, proc, z3fold, zbud, ras, mempolicy, memblock,
  migration, thp, nommu, kconfig, madvise, memory-hotplug, zswap,
  zsmalloc, zram, cleanups, kfence, and hmm), procfs, sysctl, misc,
  core-kernel, lib, lz4, checkpatch, init, kprobes, nilfs2, hfs,
  signals, exec, kcov, selftests, compress/decompress, and ipc"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (190 commits)
  ipc/util.c: use binary search for max_idx
  ipc/sem.c: use READ_ONCE()/WRITE_ONCE() for use_global_lock
  ipc: use kmalloc for msg_queue and shmid_kernel
  ipc sem: use kvmalloc for sem_undo allocation
  lib/decompressors: remove set but not used variabled 'level'
  selftests/vm/pkeys: exercise x86 XSAVE init state
  selftests/vm/pkeys: refill shadow register after implicit kernel write
  selftests/vm/pkeys: handle negative sys_pkey_alloc() return code
  selftests/vm/pkeys: fix alloc_random_pkey() to make it really, really random
  kcov: add __no_sanitize_coverage to fix noinstr for all architectures
  exec: remove checks in __register_bimfmt()
  x86: signal: don't do sas_ss_reset() until we are certain that sigframe won't be abandoned
  hfsplus: report create_date to kstat.btime
  hfsplus: remove unnecessary oom message
  nilfs2: remove redundant continue statement in a while-loop
  kprobes: remove duplicated strong free_insn_page in x86 and s390
  init: print out unknown kernel parameters
  checkpatch: do not complain about positive return values starting with EPOLL
  checkpatch: improve the indented label test
  checkpatch: scripts/spdxcheck.py now requires python3
  ...

1 files changed, 134 insertions, 169 deletions

diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index b5d95bf1025d..e32360e90274 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -121,8 +121,7 @@ enum zone_type policy_zone = 0;
  */
 static struct mempolicy default_policy = {
 	.refcnt = ATOMIC_INIT(1), /* never free it */
-	.mode = MPOL_PREFERRED,
-	.flags = MPOL_F_LOCAL,
+	.mode = MPOL_LOCAL,
 };
 
 static struct mempolicy preferred_node_policy[MAX_NUMNODES];
@@ -194,18 +193,17 @@ static int mpol_new_interleave(struct mempolicy *pol, const nodemask_t *nodes)
 {
 	if (nodes_empty(*nodes))
 		return -EINVAL;
-	pol->v.nodes = *nodes;
+	pol->nodes = *nodes;
 	return 0;
 }
 
 static int mpol_new_preferred(struct mempolicy *pol, const nodemask_t *nodes)
 {
-	if (!nodes)
-		pol->flags |= MPOL_F_LOCAL;	/* local allocation */
-	else if (nodes_empty(*nodes))
-		return -EINVAL;			/*  no allowed nodes */
-	else
-		pol->v.preferred_node = first_node(*nodes);
+	if (nodes_empty(*nodes))
+		return -EINVAL;
+
+	nodes_clear(pol->nodes);
+	node_set(first_node(*nodes), pol->nodes);
 	return 0;
 }
 
@@ -213,15 +211,14 @@ static int mpol_new_bind(struct mempolicy *pol, const nodemask_t *nodes)
 {
 	if (nodes_empty(*nodes))
 		return -EINVAL;
-	pol->v.nodes = *nodes;
+	pol->nodes = *nodes;
 	return 0;
 }
 
 /*
  * mpol_set_nodemask is called after mpol_new() to set up the nodemask, if
  * any, for the new policy.  mpol_new() has already validated the nodes
- * parameter with respect to the policy mode and flags.  But, we need to
- * handle an empty nodemask with MPOL_PREFERRED here.
+ * parameter with respect to the policy mode and flags.
  *
  * Must be called holding task's alloc_lock to protect task's mems_allowed
  * and mempolicy.  May also be called holding the mmap_lock for write.
@@ -231,33 +228,31 @@ static int mpol_set_nodemask(struct mempolicy *pol,
 {
 	int ret;
 
-	/* if mode is MPOL_DEFAULT, pol is NULL. This is right. */
-	if (pol == NULL)
+	/*
+	 * Default (pol==NULL) resp. local memory policies are not a
+	 * subject of any remapping. They also do not need any special
+	 * constructor.
+	 */
+	if (!pol || pol->mode == MPOL_LOCAL)
 		return 0;
+
 	/* Check N_MEMORY */
 	nodes_and(nsc->mask1,
 		  cpuset_current_mems_allowed, node_states[N_MEMORY]);
 
 	VM_BUG_ON(!nodes);
-	if (pol->mode == MPOL_PREFERRED && nodes_empty(*nodes))
-		nodes = NULL;	/* explicit local allocation */
-	else {
-		if (pol->flags & MPOL_F_RELATIVE_NODES)
-			mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1);
-		else
-			nodes_and(nsc->mask2, *nodes, nsc->mask1);
 
-		if (mpol_store_user_nodemask(pol))
-			pol->w.user_nodemask = *nodes;
-		else
-			pol->w.cpuset_mems_allowed =
-						cpuset_current_mems_allowed;
-	}
+	if (pol->flags & MPOL_F_RELATIVE_NODES)
+		mpol_relative_nodemask(&nsc->mask2, nodes, &nsc->mask1);
+	else
+		nodes_and(nsc->mask2, *nodes, nsc->mask1);
 
-	if (nodes)
-		ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
+	if (mpol_store_user_nodemask(pol))
+		pol->w.user_nodemask = *nodes;
 	else
-		ret = mpol_ops[pol->mode].create(pol, NULL);
+		pol->w.cpuset_mems_allowed = cpuset_current_mems_allowed;
+
+	ret = mpol_ops[pol->mode].create(pol, &nsc->mask2);
 	return ret;
 }
 
@@ -290,13 +285,14 @@ static struct mempolicy *mpol_new(unsigned short mode, unsigned short flags,
 			if (((flags & MPOL_F_STATIC_NODES) ||
 			     (flags & MPOL_F_RELATIVE_NODES)))
 				return ERR_PTR(-EINVAL);
+
+			mode = MPOL_LOCAL;
 		}
 	} else if (mode == MPOL_LOCAL) {
 		if (!nodes_empty(*nodes) ||
 		    (flags & MPOL_F_STATIC_NODES) ||
 		    (flags & MPOL_F_RELATIVE_NODES))
 			return ERR_PTR(-EINVAL);
-		mode = MPOL_PREFERRED;
 	} else if (nodes_empty(*nodes))
 		return ERR_PTR(-EINVAL);
 	policy = kmem_cache_alloc(policy_cache, GFP_KERNEL);
@@ -330,7 +326,7 @@ static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
 	else if (pol->flags & MPOL_F_RELATIVE_NODES)
 		mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
 	else {
-		nodes_remap(tmp, pol->v.nodes, pol->w.cpuset_mems_allowed,
+		nodes_remap(tmp, pol->nodes, pol->w.cpuset_mems_allowed,
 								*nodes);
 		pol->w.cpuset_mems_allowed = *nodes;
 	}
@@ -338,31 +334,13 @@ static void mpol_rebind_nodemask(struct mempolicy *pol, const nodemask_t *nodes)
 	if (nodes_empty(tmp))
 		tmp = *nodes;
 
-	pol->v.nodes = tmp;
+	pol->nodes = tmp;
 }
 
 static void mpol_rebind_preferred(struct mempolicy *pol,
 						const nodemask_t *nodes)
 {
-	nodemask_t tmp;
-
-	if (pol->flags & MPOL_F_STATIC_NODES) {
-		int node = first_node(pol->w.user_nodemask);
-
-		if (node_isset(node, *nodes)) {
-			pol->v.preferred_node = node;
-			pol->flags &= ~MPOL_F_LOCAL;
-		} else
-			pol->flags |= MPOL_F_LOCAL;
-	} else if (pol->flags & MPOL_F_RELATIVE_NODES) {
-		mpol_relative_nodemask(&tmp, &pol->w.user_nodemask, nodes);
-		pol->v.preferred_node = first_node(tmp);
-	} else if (!(pol->flags & MPOL_F_LOCAL)) {
-		pol->v.preferred_node = node_remap(pol->v.preferred_node,
-						   pol->w.cpuset_mems_allowed,
-						   *nodes);
-		pol->w.cpuset_mems_allowed = *nodes;
-	}
+	pol->w.cpuset_mems_allowed = *nodes;
 }
 
 /*
@@ -376,7 +354,7 @@ static void mpol_rebind_policy(struct mempolicy *pol, const nodemask_t *newmask)
 {
 	if (!pol)
 		return;
-	if (!mpol_store_user_nodemask(pol) && !(pol->flags & MPOL_F_LOCAL) &&
+	if (!mpol_store_user_nodemask(pol) &&
 	    nodes_equal(pol->w.cpuset_mems_allowed, *newmask))
 		return;
 
@@ -427,6 +405,9 @@ static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
 		.create = mpol_new_bind,
 		.rebind = mpol_rebind_nodemask,
 	},
+	[MPOL_LOCAL] = {
+		.rebind = mpol_rebind_default,
+	},
 };
 
 static int migrate_page_add(struct page *page, struct list_head *pagelist,
@@ -458,7 +439,8 @@ static inline bool queue_pages_required(struct page *page,
 
 /*
  * queue_pages_pmd() has four possible return values:
- * 0 - pages are placed on the right node or queued successfully.
+ * 0 - pages are placed on the right node or queued successfully, or
+ *     special page is met, i.e. huge zero page.
  * 1 - there is unmovable page, and MPOL_MF_MOVE* & MPOL_MF_STRICT were
  *     specified.
  * 2 - THP was split.
@@ -482,8 +464,7 @@ static int queue_pages_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr,
 	page = pmd_page(*pmd);
 	if (is_huge_zero_page(page)) {
 		spin_unlock(ptl);
-		__split_huge_pmd(walk->vma, pmd, addr, false, NULL);
-		ret = 2;
+		walk->action = ACTION_CONTINUE;
 		goto out;
 	}
 	if (!queue_pages_required(page, qp))
@@ -510,7 +491,8 @@ out:
  * 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.
+ * 0 - pages are placed on the right node or queued successfully, or
+ *     special page is met, i.e. zero page.
  * 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
@@ -917,12 +899,11 @@ static void get_policy_nodemask(struct mempolicy *p, nodemask_t *nodes)
 	switch (p->mode) {
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
-		*nodes = p->v.nodes;
-		break;
 	case MPOL_PREFERRED:
-		if (!(p->flags & MPOL_F_LOCAL))
-			node_set(p->v.preferred_node, *nodes);
-		/* else return empty node mask for local allocation */
+		*nodes = p->nodes;
+		break;
+	case MPOL_LOCAL:
+		/* return empty node mask for local allocation */
 		break;
 	default:
 		BUG();
@@ -1007,7 +988,7 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
 			*policy = err;
 		} else if (pol == current->mempolicy &&
 				pol->mode == MPOL_INTERLEAVE) {
-			*policy = next_node_in(current->il_prev, pol->v.nodes);
+			*policy = next_node_in(current->il_prev, pol->nodes);
 		} else {
 			err = -EINVAL;
 			goto out;
@@ -1460,26 +1441,38 @@ static int copy_nodes_to_user(unsigned long __user *mask, unsigned long maxnode,
 	return copy_to_user(mask, nodes_addr(*nodes), copy) ? -EFAULT : 0;
 }
 
+/* Basic parameter sanity check used by both mbind() and set_mempolicy() */
+static inline int sanitize_mpol_flags(int *mode, unsigned short *flags)
+{
+	*flags = *mode & MPOL_MODE_FLAGS;
+	*mode &= ~MPOL_MODE_FLAGS;
+	if ((unsigned int)(*mode) >= MPOL_MAX)
+		return -EINVAL;
+	if ((*flags & MPOL_F_STATIC_NODES) && (*flags & MPOL_F_RELATIVE_NODES))
+		return -EINVAL;
+
+	return 0;
+}
+
 static long kernel_mbind(unsigned long start, unsigned long len,
 			 unsigned long mode, const unsigned long __user *nmask,
 			 unsigned long maxnode, unsigned int flags)
 {
+	unsigned short mode_flags;
 	nodemask_t nodes;
+	int lmode = mode;
 	int err;
-	unsigned short mode_flags;
 
 	start = untagged_addr(start);
-	mode_flags = mode & MPOL_MODE_FLAGS;
-	mode &= ~MPOL_MODE_FLAGS;
-	if (mode >= MPOL_MAX)
-		return -EINVAL;
-	if ((mode_flags & MPOL_F_STATIC_NODES) &&
-	    (mode_flags & MPOL_F_RELATIVE_NODES))
-		return -EINVAL;
+	err = sanitize_mpol_flags(&lmode, &mode_flags);
+	if (err)
+		return err;
+
 	err = get_nodes(&nodes, nmask, maxnode);
 	if (err)
 		return err;
-	return do_mbind(start, len, mode, mode_flags, &nodes, flags);
+
+	return do_mbind(start, len, lmode, mode_flags, &nodes, flags);
 }
 
 SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
@@ -1493,20 +1486,20 @@ SYSCALL_DEFINE6(mbind, unsigned long, start, unsigned long, len,
 static long kernel_set_mempolicy(int mode, const unsigned long __user *nmask,
 				 unsigned long maxnode)
 {
-	int err;
+	unsigned short mode_flags;
 	nodemask_t nodes;
-	unsigned short flags;
+	int lmode = mode;
+	int err;
+
+	err = sanitize_mpol_flags(&lmode, &mode_flags);
+	if (err)
+		return err;
 
-	flags = mode & MPOL_MODE_FLAGS;
-	mode &= ~MPOL_MODE_FLAGS;
-	if ((unsigned int)mode >= MPOL_MAX)
-		return -EINVAL;
-	if ((flags & MPOL_F_STATIC_NODES) && (flags & MPOL_F_RELATIVE_NODES))
-		return -EINVAL;
 	err = get_nodes(&nodes, nmask, maxnode);
 	if (err)
 		return err;
-	return do_set_mempolicy(mode, flags, &nodes);
+
+	return do_set_mempolicy(lmode, mode_flags, &nodes);
 }
 
 SYSCALL_DEFINE3(set_mempolicy, int, mode, const unsigned long __user *, nmask,
@@ -1863,14 +1856,14 @@ static int apply_policy_zone(struct mempolicy *policy, enum zone_type zone)
 	BUG_ON(dynamic_policy_zone == ZONE_MOVABLE);
 
 	/*
-	 * if policy->v.nodes has movable memory only,
+	 * if policy->nodes has movable memory only,
 	 * we apply policy when gfp_zone(gfp) = ZONE_MOVABLE only.
 	 *
-	 * policy->v.nodes is intersect with node_states[N_MEMORY].
+	 * policy->nodes is intersect with node_states[N_MEMORY].
 	 * so if the following test fails, it implies
-	 * policy->v.nodes has movable memory only.
+	 * policy->nodes has movable memory only.
 	 */
-	if (!nodes_intersects(policy->v.nodes, node_states[N_HIGH_MEMORY]))
+	if (!nodes_intersects(policy->nodes, node_states[N_HIGH_MEMORY]))
 		dynamic_policy_zone = ZONE_MOVABLE;
 
 	return zone >= dynamic_policy_zone;
@@ -1885,8 +1878,8 @@ nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
 	/* Lower zones don't get a nodemask applied for MPOL_BIND */
 	if (unlikely(policy->mode == MPOL_BIND) &&
 			apply_policy_zone(policy, gfp_zone(gfp)) &&
-			cpuset_nodemask_valid_mems_allowed(&policy->v.nodes))
-		return &policy->v.nodes;
+			cpuset_nodemask_valid_mems_allowed(&policy->nodes))
+		return &policy->nodes;
 
 	return NULL;
 }
@@ -1894,9 +1887,9 @@ nodemask_t *policy_nodemask(gfp_t gfp, struct mempolicy *policy)
 /* Return the node id preferred by the given mempolicy, or the given id */
 static int policy_node(gfp_t gfp, struct mempolicy *policy, int nd)
 {
-	if (policy->mode == MPOL_PREFERRED && !(policy->flags & MPOL_F_LOCAL))
-		nd = policy->v.preferred_node;
-	else {
+	if (policy->mode == MPOL_PREFERRED) {
+		nd = first_node(policy->nodes);
+	} else {
 		/*
 		 * __GFP_THISNODE shouldn't even be used with the bind policy
 		 * because we might easily break the expectation to stay on the
@@ -1914,7 +1907,7 @@ static unsigned interleave_nodes(struct mempolicy *policy)
 	unsigned next;
 	struct task_struct *me = current;
 
-	next = next_node_in(me->il_prev, policy->v.nodes);
+	next = next_node_in(me->il_prev, policy->nodes);
 	if (next < MAX_NUMNODES)
 		me->il_prev = next;
 	return next;
@@ -1933,15 +1926,12 @@ unsigned int mempolicy_slab_node(void)
 		return node;
 
 	policy = current->mempolicy;
-	if (!policy || policy->flags & MPOL_F_LOCAL)
+	if (!policy)
 		return node;
 
 	switch (policy->mode) {
 	case MPOL_PREFERRED:
-		/*
-		 * handled MPOL_F_LOCAL above
-		 */
-		return policy->v.preferred_node;
+		return first_node(policy->nodes);
 
 	case MPOL_INTERLEAVE:
 		return interleave_nodes(policy);
@@ -1957,9 +1947,11 @@ unsigned int mempolicy_slab_node(void)
 		enum zone_type highest_zoneidx = gfp_zone(GFP_KERNEL);
 		zonelist = &NODE_DATA(node)->node_zonelists[ZONELIST_FALLBACK];
 		z = first_zones_zonelist(zonelist, highest_zoneidx,
-							&policy->v.nodes);
+							&policy->nodes);
 		return z->zone ? zone_to_nid(z->zone) : node;
 	}
+	case MPOL_LOCAL:
+		return node;
 
 	default:
 		BUG();
@@ -1968,12 +1960,12 @@ unsigned int mempolicy_slab_node(void)
 
 /*
  * Do static interleaving for a VMA with known offset @n.  Returns the n'th
- * node in pol->v.nodes (starting from n=0), wrapping around if n exceeds the
+ * node in pol->nodes (starting from n=0), wrapping around if n exceeds the
  * number of present nodes.
  */
 static unsigned offset_il_node(struct mempolicy *pol, unsigned long n)
 {
-	unsigned nnodes = nodes_weight(pol->v.nodes);
+	unsigned nnodes = nodes_weight(pol->nodes);
 	unsigned target;
 	int i;
 	int nid;
@@ -1981,9 +1973,9 @@ static unsigned offset_il_node(struct mempolicy *pol, unsigned long n)
 	if (!nnodes)
 		return numa_node_id();
 	target = (unsigned int)n % nnodes;
-	nid = first_node(pol->v.nodes);
+	nid = first_node(pol->nodes);
 	for (i = 0; i < target; i++)
-		nid = next_node(nid, pol->v.nodes);
+		nid = next_node(nid, pol->nodes);
 	return nid;
 }
 
@@ -2039,7 +2031,7 @@ int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags,
 	} else {
 		nid = policy_node(gfp_flags, *mpol, numa_node_id());
 		if ((*mpol)->mode == MPOL_BIND)
-			*nodemask = &(*mpol)->v.nodes;
+			*nodemask = &(*mpol)->nodes;
 	}
 	return nid;
 }
@@ -2063,7 +2055,6 @@ int huge_node(struct vm_area_struct *vma, unsigned long addr, gfp_t gfp_flags,
 bool init_nodemask_of_mempolicy(nodemask_t *mask)
 {
 	struct mempolicy *mempolicy;
-	int nid;
 
 	if (!(mask && current->mempolicy))
 		return false;
@@ -2072,16 +2063,13 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask)
 	mempolicy = current->mempolicy;
 	switch (mempolicy->mode) {
 	case MPOL_PREFERRED:
-		if (mempolicy->flags & MPOL_F_LOCAL)
-			nid = numa_node_id();
-		else
-			nid = mempolicy->v.preferred_node;
-		init_nodemask_of_node(mask, nid);
-		break;
-
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
-		*mask =  mempolicy->v.nodes;
+		*mask = mempolicy->nodes;
+		break;
+
+	case MPOL_LOCAL:
+		init_nodemask_of_node(mask, numa_node_id());
 		break;
 
 	default:
@@ -2094,16 +2082,16 @@ bool init_nodemask_of_mempolicy(nodemask_t *mask)
 #endif
 
 /*
- * mempolicy_nodemask_intersects
+ * mempolicy_in_oom_domain
  *
- * If tsk's mempolicy is "default" [NULL], return 'true' to indicate default
- * policy.  Otherwise, check for intersection between mask and the policy
- * nodemask for 'bind' or 'interleave' policy.  For 'preferred' or 'local'
- * policy, always return true since it may allocate elsewhere on fallback.
+ * If tsk's mempolicy is "bind", check for intersection between mask and
+ * the policy nodemask. Otherwise, return true for all other policies
+ * including "interleave", as a tsk with "interleave" policy may have
+ * memory allocated from all nodes in system.
  *
  * Takes task_lock(tsk) to prevent freeing of its mempolicy.
  */
-bool mempolicy_nodemask_intersects(struct task_struct *tsk,
+bool mempolicy_in_oom_domain(struct task_struct *tsk,
 					const nodemask_t *mask)
 {
 	struct mempolicy *mempolicy;
@@ -2111,29 +2099,13 @@ bool mempolicy_nodemask_intersects(struct task_struct *tsk,
 
 	if (!mask)
 		return ret;
+
 	task_lock(tsk);
 	mempolicy = tsk->mempolicy;
-	if (!mempolicy)
-		goto out;
-
-	switch (mempolicy->mode) {
-	case MPOL_PREFERRED:
-		/*
-		 * MPOL_PREFERRED and MPOL_F_LOCAL are only preferred nodes to
-		 * allocate from, they may fallback to other nodes when oom.
-		 * Thus, it's possible for tsk to have allocated memory from
-		 * nodes in mask.
-		 */
-		break;
-	case MPOL_BIND:
-	case MPOL_INTERLEAVE:
-		ret = nodes_intersects(mempolicy->v.nodes, *mask);
-		break;
-	default:
-		BUG();
-	}
-out:
+	if (mempolicy && mempolicy->mode == MPOL_BIND)
+		ret = nodes_intersects(mempolicy->nodes, *mask);
 	task_unlock(tsk);
+
 	return ret;
 }
 
@@ -2204,8 +2176,8 @@ struct page *alloc_pages_vma(gfp_t gfp, int order, struct vm_area_struct *vma,
 		 * If the policy is interleave, or does not allow the current
 		 * node in its nodemask, we allocate the standard way.
 		 */
-		if (pol->mode == MPOL_PREFERRED && !(pol->flags & MPOL_F_LOCAL))
-			hpage_node = pol->v.preferred_node;
+		if (pol->mode == MPOL_PREFERRED)
+			hpage_node = first_node(pol->nodes);
 
 		nmask = policy_nodemask(gfp, pol);
 		if (!nmask || node_isset(hpage_node, *nmask)) {
@@ -2338,12 +2310,10 @@ bool __mpol_equal(struct mempolicy *a, struct mempolicy *b)
 	switch (a->mode) {
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
-		return !!nodes_equal(a->v.nodes, b->v.nodes);
 	case MPOL_PREFERRED:
-		/* a's ->flags is the same as b's */
-		if (a->flags & MPOL_F_LOCAL)
-			return true;
-		return a->v.preferred_node == b->v.preferred_node;
+		return !!nodes_equal(a->nodes, b->nodes);
+	case MPOL_LOCAL:
+		return true;
 	default:
 		BUG();
 		return false;
@@ -2481,16 +2451,17 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long
 		break;
 
 	case MPOL_PREFERRED:
-		if (pol->flags & MPOL_F_LOCAL)
-			polnid = numa_node_id();
-		else
-			polnid = pol->v.preferred_node;
+		polnid = first_node(pol->nodes);
+		break;
+
+	case MPOL_LOCAL:
+		polnid = numa_node_id();
 		break;
 
 	case MPOL_BIND:
 		/* Optimize placement among multiple nodes via NUMA balancing */
 		if (pol->flags & MPOL_F_MORON) {
-			if (node_isset(thisnid, pol->v.nodes))
+			if (node_isset(thisnid, pol->nodes))
 				break;
 			goto out;
 		}
@@ -2501,12 +2472,12 @@ int mpol_misplaced(struct page *page, struct vm_area_struct *vma, unsigned long
 		 * else select nearest allowed node, if any.
 		 * If no allowed nodes, use current [!misplaced].
 		 */
-		if (node_isset(curnid, pol->v.nodes))
+		if (node_isset(curnid, pol->nodes))
 			goto out;
 		z = first_zones_zonelist(
 				node_zonelist(numa_node_id(), GFP_HIGHUSER),
 				gfp_zone(GFP_HIGHUSER),
-				&pol->v.nodes);
+				&pol->nodes);
 		polnid = zone_to_nid(z->zone);
 		break;
 
@@ -2709,7 +2680,7 @@ int mpol_set_shared_policy(struct shared_policy *info,
 		 vma->vm_pgoff,
 		 sz, npol ? npol->mode : -1,
 		 npol ? npol->flags : -1,
-		 npol ? nodes_addr(npol->v.nodes)[0] : NUMA_NO_NODE);
+		 npol ? nodes_addr(npol->nodes)[0] : NUMA_NO_NODE);
 
 	if (npol) {
 		new = sp_alloc(vma->vm_pgoff, vma->vm_pgoff + sz, npol);
@@ -2807,7 +2778,7 @@ void __init numa_policy_init(void)
 			.refcnt = ATOMIC_INIT(1),
 			.mode = MPOL_PREFERRED,
 			.flags = MPOL_F_MOF | MPOL_F_MORON,
-			.v = { .preferred_node = nid, },
+			.nodes = nodemask_of_node(nid),
 		};
 	}
 
@@ -2851,9 +2822,6 @@ void numa_default_policy(void)
  * Parse and format mempolicy from/to strings
  */
 
-/*
- * "local" is implemented internally by MPOL_PREFERRED with MPOL_F_LOCAL flag.
- */
 static const char * const policy_modes[] =
 {
 	[MPOL_DEFAULT]    = "default",
@@ -2931,7 +2899,6 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
 		 */
 		if (nodelist)
 			goto out;
-		mode = MPOL_PREFERRED;
 		break;
 	case MPOL_DEFAULT:
 		/*
@@ -2970,12 +2937,14 @@ int mpol_parse_str(char *str, struct mempolicy **mpol)
 	 * Save nodes for mpol_to_str() to show the tmpfs mount options
 	 * for /proc/mounts, /proc/pid/mounts and /proc/pid/mountinfo.
 	 */
-	if (mode != MPOL_PREFERRED)
-		new->v.nodes = nodes;
-	else if (nodelist)
-		new->v.preferred_node = first_node(nodes);
-	else
-		new->flags |= MPOL_F_LOCAL;
+	if (mode != MPOL_PREFERRED) {
+		new->nodes = nodes;
+	} else if (nodelist) {
+		nodes_clear(new->nodes);
+		node_set(first_node(nodes), new->nodes);
+	} else {
+		new->mode = MPOL_LOCAL;
+	}
 
 	/*
 	 * Save nodes for contextualization: this will be used to "clone"
@@ -3021,16 +2990,12 @@ void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol)
 
 	switch (mode) {
 	case MPOL_DEFAULT:
+	case MPOL_LOCAL:
 		break;
 	case MPOL_PREFERRED:
-		if (flags & MPOL_F_LOCAL)
-			mode = MPOL_LOCAL;
-		else
-			node_set(pol->v.preferred_node, nodes);
-		break;
 	case MPOL_BIND:
 	case MPOL_INTERLEAVE:
-		nodes = pol->v.nodes;
+		nodes = pol->nodes;
 		break;
 	default:
 		WARN_ON_ONCE(1);