3 files changed, 16 insertions, 11 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 404e53bb212..253d205914b 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -915,6 +915,21 @@ static int shmem_writepage(struct page *page, struct writeback_control *wbc)
 	struct inode *inode;
 
 	BUG_ON(!PageLocked(page));
+	/*
+	 * shmem_backing_dev_info's capabilities prevent regular writeback or
+	 * sync from ever calling shmem_writepage; but a stacking filesystem
+	 * may use the ->writepage of its underlying filesystem, in which case
+	 * we want to do nothing when that underlying filesystem is tmpfs
+	 * (writing out to swap is useful as a response to memory pressure, but
+	 * of no use to stabilize the data) - just redirty the page, unlock it
+	 * and claim success in this case.  AOP_WRITEPAGE_ACTIVATE, and the
+	 * page_mapped check below, must be avoided unless we're in reclaim.
+	 */
+	if (!wbc->for_reclaim) {
+		set_page_dirty(page);
+		unlock_page(page);
+		return 0;
+	}
 	BUG_ON(page_mapped(page));
 
 	mapping = page->mapping;
diff --git a/mm/sparse-vmemmap.c b/mm/sparse-vmemmap.c
index d3b718b0c20..22620f6a976 100644
--- a/mm/sparse-vmemmap.c
+++ b/mm/sparse-vmemmap.c
@@ -24,6 +24,7 @@
 #include <linux/module.h>
 #include <linux/spinlock.h>
 #include <linux/vmalloc.h>
+#include <linux/sched.h>
 #include <asm/dma.h>
 #include <asm/pgalloc.h>
 #include <asm/pgtable.h>
diff --git a/mm/sparse.c b/mm/sparse.c
index 08fb14f5eea..e06f514fe04 100644
--- a/mm/sparse.c
+++ b/mm/sparse.c
@@ -220,12 +220,6 @@ static int __meminit sparse_init_one_section(struct mem_section *ms,
 	return 1;
 }
 
-__attribute__((weak)) __init
-void *alloc_bootmem_high_node(pg_data_t *pgdat, unsigned long size)
-{
-	return NULL;
-}
-
 static unsigned long usemap_size(void)
 {
 	unsigned long size_bytes;
@@ -267,11 +261,6 @@ struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid)
 	if (map)
 		return map;
 
-  	map = alloc_bootmem_high_node(NODE_DATA(nid),
-                       sizeof(struct page) * PAGES_PER_SECTION);
-	if (map)
-		return map;
-
 	map = alloc_bootmem_node(NODE_DATA(nid),
 			sizeof(struct page) * PAGES_PER_SECTION);
 	return map;