Merge branch 'akpm' (Andrew's patchbomb)

Merge misc updates from Andrew Morton:
 "About half of most of MM.  Going very early this time due to
  uncertainty over the coreautounifiednumasched things.  I'll send the
  other half of most of MM tomorrow.  The rest of MM awaits a slab merge
  from Pekka."

* emailed patches from Andrew Morton: (71 commits)
  memory_hotplug: ensure every online node has NORMAL memory
  memory_hotplug: handle empty zone when online_movable/online_kernel
  mm, memory-hotplug: dynamic configure movable memory and portion memory
  drivers/base/node.c: cleanup node_state_attr[]
  bootmem: fix wrong call parameter for free_bootmem()
  avr32, kconfig: remove HAVE_ARCH_BOOTMEM
  mm: cma: remove watermark hacks
  mm: cma: skip watermarks check for already isolated blocks in split_free_page()
  mm, oom: fix race when specifying a thread as the oom origin
  mm, oom: change type of oom_score_adj to short
  mm: cleanup register_node()
  mm, mempolicy: remove duplicate code
  mm/vmscan.c: try_to_freeze() returns boolean
  mm: introduce putback_movable_pages()
  virtio_balloon: introduce migration primitives to balloon pages
  mm: introduce compaction and migration for ballooned pages
  mm: introduce a common interface for balloon pages mobility
  mm: redefine address_space.assoc_mapping
  mm: adjust address_space_operations.migratepage() return code
  arch/sparc/kernel/sys_sparc_64.c: s/COLOUR/COLOR/
  ...

1 files changed, 19 insertions, 12 deletions

diff --git a/mm/swapfile.c b/mm/swapfile.c
index f91a25547ff..e97a0e5aea9 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1443,13 +1443,12 @@ static int setup_swap_extents(struct swap_info_struct *sis, sector_t *span)
 	return generic_swapfile_activate(sis, swap_file, span);
 }
 
-static void enable_swap_info(struct swap_info_struct *p, int prio,
+static void _enable_swap_info(struct swap_info_struct *p, int prio,
 				unsigned char *swap_map,
 				unsigned long *frontswap_map)
 {
 	int i, prev;
 
-	spin_lock(&swap_lock);
 	if (prio >= 0)
 		p->prio = prio;
 	else
@@ -1472,10 +1471,25 @@ static void enable_swap_info(struct swap_info_struct *p, int prio,
 		swap_list.head = swap_list.next = p->type;
 	else
 		swap_info[prev]->next = p->type;
+}
+
+static void enable_swap_info(struct swap_info_struct *p, int prio,
+				unsigned char *swap_map,
+				unsigned long *frontswap_map)
+{
+	spin_lock(&swap_lock);
+	_enable_swap_info(p, prio, swap_map, frontswap_map);
 	frontswap_init(p->type);
 	spin_unlock(&swap_lock);
 }
 
+static void reinsert_swap_info(struct swap_info_struct *p)
+{
+	spin_lock(&swap_lock);
+	_enable_swap_info(p, p->prio, p->swap_map, frontswap_map_get(p));
+	spin_unlock(&swap_lock);
+}
+
 SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 {
 	struct swap_info_struct *p = NULL;
@@ -1484,7 +1498,6 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	struct address_space *mapping;
 	struct inode *inode;
 	struct filename *pathname;
-	int oom_score_adj;
 	int i, type, prev;
 	int err;
 
@@ -1543,19 +1556,13 @@ SYSCALL_DEFINE1(swapoff, const char __user *, specialfile)
 	p->flags &= ~SWP_WRITEOK;
 	spin_unlock(&swap_lock);
 
-	oom_score_adj = test_set_oom_score_adj(OOM_SCORE_ADJ_MAX);
+	set_current_oom_origin();
 	err = try_to_unuse(type, false, 0); /* force all pages to be unused */
-	compare_swap_oom_score_adj(OOM_SCORE_ADJ_MAX, oom_score_adj);
+	clear_current_oom_origin();
 
 	if (err) {
-		/*
-		 * reading p->prio and p->swap_map outside the lock is
-		 * safe here because only sys_swapon and sys_swapoff
-		 * change them, and there can be no other sys_swapon or
-		 * sys_swapoff for this swap_info_struct at this point.
-		 */
 		/* re-insert swap space back into swap_list */
-		enable_swap_info(p, p->prio, p->swap_map, frontswap_map_get(p));
+		reinsert_swap_info(p);
 		goto out_dput;
 	}