Merge branch 'akpm' (patches from Andrew)

Merge updates from Andrew Morton:

 - a few misc things

 - a few Y2038 fixes

 - ntfs fixes

 - arch/sh tweaks

 - ocfs2 updates

 - most of MM

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (111 commits)
  mm/hmm.c: remove unused variables align_start and align_end
  fs/userfaultfd.c: remove redundant pointer uwq
  mm, vmacache: hash addresses based on pmd
  mm/list_lru: introduce list_lru_shrink_walk_irq()
  mm/list_lru.c: pass struct list_lru_node* as an argument to __list_lru_walk_one()
  mm/list_lru.c: move locking from __list_lru_walk_one() to its caller
  mm/list_lru.c: use list_lru_walk_one() in list_lru_walk_node()
  mm, swap: make CONFIG_THP_SWAP depend on CONFIG_SWAP
  mm/sparse: delete old sparse_init and enable new one
  mm/sparse: add new sparse_init_nid() and sparse_init()
  mm/sparse: move buffer init/fini to the common place
  mm/sparse: use the new sparse buffer functions in non-vmemmap
  mm/sparse: abstract sparse buffer allocations
  mm/hugetlb.c: don't zero 1GiB bootmem pages
  mm, page_alloc: double zone's batchsize
  mm/oom_kill.c: document oom_lock
  mm/hugetlb: remove gigantic page support for HIGHMEM
  mm, oom: remove sleep from under oom_lock
  kernel/dma: remove unsupported gfp_mask parameter from dma_alloc_from_contiguous()
  mm/cma: remove unsupported gfp_mask parameter from cma_alloc()
  ...

1 files changed, 47 insertions, 49 deletions

diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 7deb49f69e27..4eb6e824a80c 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1034,8 +1034,10 @@ static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start)
 	return pgdat;
 }
 
-static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
+static void rollback_node_hotadd(int nid)
 {
+	pg_data_t *pgdat = NODE_DATA(nid);
+
 	arch_refresh_nodedata(nid, NULL);
 	free_percpu(pgdat->per_cpu_nodestats);
 	arch_free_nodedata(pgdat);
@@ -1046,28 +1048,48 @@ static void rollback_node_hotadd(int nid, pg_data_t *pgdat)
 /**
  * try_online_node - online a node if offlined
  * @nid: the node ID
- *
+ * @start: start addr of the node
+ * @set_node_online: Whether we want to online the node
  * called by cpu_up() to online a node without onlined memory.
+ *
+ * Returns:
+ * 1 -> a new node has been allocated
+ * 0 -> the node is already online
+ * -ENOMEM -> the node could not be allocated
  */
-int try_online_node(int nid)
+static int __try_online_node(int nid, u64 start, bool set_node_online)
 {
-	pg_data_t	*pgdat;
-	int	ret;
+	pg_data_t *pgdat;
+	int ret = 1;
 
 	if (node_online(nid))
 		return 0;
 
-	mem_hotplug_begin();
-	pgdat = hotadd_new_pgdat(nid, 0);
+	pgdat = hotadd_new_pgdat(nid, start);
 	if (!pgdat) {
 		pr_err("Cannot online node %d due to NULL pgdat\n", nid);
 		ret = -ENOMEM;
 		goto out;
 	}
-	node_set_online(nid);
-	ret = register_one_node(nid);
-	BUG_ON(ret);
+
+	if (set_node_online) {
+		node_set_online(nid);
+		ret = register_one_node(nid);
+		BUG_ON(ret);
+	}
 out:
+	return ret;
+}
+
+/*
+ * Users of this function always want to online/register the node
+ */
+int try_online_node(int nid)
+{
+	int ret;
+
+	mem_hotplug_begin();
+	ret =  __try_online_node(nid, 0, true);
 	mem_hotplug_done();
 	return ret;
 }
@@ -1099,9 +1121,7 @@ static int online_memory_block(struct memory_block *mem, void *arg)
 int __ref add_memory_resource(int nid, struct resource *res, bool online)
 {
 	u64 start, size;
-	pg_data_t *pgdat = NULL;
-	bool new_pgdat;
-	bool new_node;
+	bool new_node = false;
 	int ret;
 
 	start = res->start;
@@ -1111,11 +1131,6 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
 	if (ret)
 		return ret;
 
-	{	/* Stupid hack to suppress address-never-null warning */
-		void *p = NODE_DATA(nid);
-		new_pgdat = !p;
-	}
-
 	mem_hotplug_begin();
 
 	/*
@@ -1126,48 +1141,31 @@ int __ref add_memory_resource(int nid, struct resource *res, bool online)
 	 */
 	memblock_add_node(start, size, nid);
 
-	new_node = !node_online(nid);
-	if (new_node) {
-		pgdat = hotadd_new_pgdat(nid, start);
-		ret = -ENOMEM;
-		if (!pgdat)
-			goto error;
-	}
+	ret = __try_online_node(nid, start, false);
+	if (ret < 0)
+		goto error;
+	new_node = ret;
 
 	/* call arch's memory hotadd */
 	ret = arch_add_memory(nid, start, size, NULL, true);
-
 	if (ret < 0)
 		goto error;
 
-	/* we online node here. we can't roll back from here. */
-	node_set_online(nid);
-
 	if (new_node) {
-		unsigned long start_pfn = start >> PAGE_SHIFT;
-		unsigned long nr_pages = size >> PAGE_SHIFT;
-
-		ret = __register_one_node(nid);
-		if (ret)
-			goto register_fail;
-
-		/*
-		 * link memory sections under this node. This is already
-		 * done when creatig memory section in register_new_memory
-		 * but that depends to have the node registered so offline
-		 * nodes have to go through register_node.
-		 * TODO clean up this mess.
-		 */
-		ret = link_mem_sections(nid, start_pfn, nr_pages, false);
-register_fail:
-		/*
-		 * If sysfs file of new node can't create, cpu on the node
+		/* If sysfs file of new node can't be created, cpu on the node
 		 * can't be hot-added. There is no rollback way now.
 		 * So, check by BUG_ON() to catch it reluctantly..
+		 * We online node here. We can't roll back from here.
 		 */
+		node_set_online(nid);
+		ret = __register_one_node(nid);
 		BUG_ON(ret);
 	}
 
+	/* link memory sections under this node.*/
+	ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1));
+	BUG_ON(ret);
+
 	/* create new memmap entry */
 	firmware_map_add_hotplug(start, start + size, "System RAM");
 
@@ -1180,8 +1178,8 @@ register_fail:
 
 error:
 	/* rollback pgdat allocation and others */
-	if (new_pgdat && pgdat)
-		rollback_node_hotadd(nid, pgdat);
+	if (new_node)
+		rollback_node_hotadd(nid);
 	memblock_remove(start, size);
 
 out: