Merge branch 'linus' into x86/urgent

1 files changed, 1231 insertions, 381 deletions

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index ab171274ef21..a8bf4ab01f86 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -14,6 +14,8 @@
 #include <linux/mempolicy.h>
 #include <linux/cpuset.h>
 #include <linux/mutex.h>
+#include <linux/bootmem.h>
+#include <linux/sysfs.h>
 
 #include <asm/page.h>
 #include <asm/pgtable.h>
@@ -22,30 +24,340 @@
 #include "internal.h"
 
 const unsigned long hugetlb_zero = 0, hugetlb_infinity = ~0UL;
-static unsigned long nr_huge_pages, free_huge_pages, resv_huge_pages;
-static unsigned long surplus_huge_pages;
-static unsigned long nr_overcommit_huge_pages;
-unsigned long max_huge_pages;
-unsigned long sysctl_overcommit_huge_pages;
-static struct list_head hugepage_freelists[MAX_NUMNODES];
-static unsigned int nr_huge_pages_node[MAX_NUMNODES];
-static unsigned int free_huge_pages_node[MAX_NUMNODES];
-static unsigned int surplus_huge_pages_node[MAX_NUMNODES];
 static gfp_t htlb_alloc_mask = GFP_HIGHUSER;
 unsigned long hugepages_treat_as_movable;
-static int hugetlb_next_nid;
+
+static int max_hstate;
+unsigned int default_hstate_idx;
+struct hstate hstates[HUGE_MAX_HSTATE];
+
+__initdata LIST_HEAD(huge_boot_pages);
+
+/* for command line parsing */
+static struct hstate * __initdata parsed_hstate;
+static unsigned long __initdata default_hstate_max_huge_pages;
+static unsigned long __initdata default_hstate_size;
+
+#define for_each_hstate(h) \
+	for ((h) = hstates; (h) < &hstates[max_hstate]; (h)++)
 
 /*
  * Protects updates to hugepage_freelists, nr_huge_pages, and free_huge_pages
  */
 static DEFINE_SPINLOCK(hugetlb_lock);
 
-static void clear_huge_page(struct page *page, unsigned long addr)
+/*
+ * Region tracking -- allows tracking of reservations and instantiated pages
+ *                    across the pages in a mapping.
+ *
+ * The region data structures are protected by a combination of the mmap_sem
+ * and the hugetlb_instantion_mutex.  To access or modify a region the caller
+ * must either hold the mmap_sem for write, or the mmap_sem for read and
+ * the hugetlb_instantiation mutex:
+ *
+ * 	down_write(&mm->mmap_sem);
+ * or
+ * 	down_read(&mm->mmap_sem);
+ * 	mutex_lock(&hugetlb_instantiation_mutex);
+ */
+struct file_region {
+	struct list_head link;
+	long from;
+	long to;
+};
+
+static long region_add(struct list_head *head, long f, long t)
+{
+	struct file_region *rg, *nrg, *trg;
+
+	/* Locate the region we are either in or before. */
+	list_for_each_entry(rg, head, link)
+		if (f <= rg->to)
+			break;
+
+	/* Round our left edge to the current segment if it encloses us. */
+	if (f > rg->from)
+		f = rg->from;
+
+	/* Check for and consume any regions we now overlap with. */
+	nrg = rg;
+	list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+		if (&rg->link == head)
+			break;
+		if (rg->from > t)
+			break;
+
+		/* If this area reaches higher then extend our area to
+		 * include it completely.  If this is not the first area
+		 * which we intend to reuse, free it. */
+		if (rg->to > t)
+			t = rg->to;
+		if (rg != nrg) {
+			list_del(&rg->link);
+			kfree(rg);
+		}
+	}
+	nrg->from = f;
+	nrg->to = t;
+	return 0;
+}
+
+static long region_chg(struct list_head *head, long f, long t)
+{
+	struct file_region *rg, *nrg;
+	long chg = 0;
+
+	/* Locate the region we are before or in. */
+	list_for_each_entry(rg, head, link)
+		if (f <= rg->to)
+			break;
+
+	/* If we are below the current region then a new region is required.
+	 * Subtle, allocate a new region at the position but make it zero
+	 * size such that we can guarantee to record the reservation. */
+	if (&rg->link == head || t < rg->from) {
+		nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
+		if (!nrg)
+			return -ENOMEM;
+		nrg->from = f;
+		nrg->to   = f;
+		INIT_LIST_HEAD(&nrg->link);
+		list_add(&nrg->link, rg->link.prev);
+
+		return t - f;
+	}
+
+	/* Round our left edge to the current segment if it encloses us. */
+	if (f > rg->from)
+		f = rg->from;
+	chg = t - f;
+
+	/* Check for and consume any regions we now overlap with. */
+	list_for_each_entry(rg, rg->link.prev, link) {
+		if (&rg->link == head)
+			break;
+		if (rg->from > t)
+			return chg;
+
+		/* We overlap with this area, if it extends futher than
+		 * us then we must extend ourselves.  Account for its
+		 * existing reservation. */
+		if (rg->to > t) {
+			chg += rg->to - t;
+			t = rg->to;
+		}
+		chg -= rg->to - rg->from;
+	}
+	return chg;
+}
+
+static long region_truncate(struct list_head *head, long end)
+{
+	struct file_region *rg, *trg;
+	long chg = 0;
+
+	/* Locate the region we are either in or before. */
+	list_for_each_entry(rg, head, link)
+		if (end <= rg->to)
+			break;
+	if (&rg->link == head)
+		return 0;
+
+	/* If we are in the middle of a region then adjust it. */
+	if (end > rg->from) {
+		chg = rg->to - end;
+		rg->to = end;
+		rg = list_entry(rg->link.next, typeof(*rg), link);
+	}
+
+	/* Drop any remaining regions. */
+	list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
+		if (&rg->link == head)
+			break;
+		chg += rg->to - rg->from;
+		list_del(&rg->link);
+		kfree(rg);
+	}
+	return chg;
+}
+
+static long region_count(struct list_head *head, long f, long t)
+{
+	struct file_region *rg;
+	long chg = 0;
+
+	/* Locate each segment we overlap with, and count that overlap. */
+	list_for_each_entry(rg, head, link) {
+		int seg_from;
+		int seg_to;
+
+		if (rg->to <= f)
+			continue;
+		if (rg->from >= t)
+			break;
+
+		seg_from = max(rg->from, f);
+		seg_to = min(rg->to, t);
+
+		chg += seg_to - seg_from;
+	}
+
+	return chg;
+}
+
+/*
+ * Convert the address within this vma to the page offset within
+ * the mapping, in pagecache page units; huge pages here.
+ */
+static pgoff_t vma_hugecache_offset(struct hstate *h,
+			struct vm_area_struct *vma, unsigned long address)
+{
+	return ((address - vma->vm_start) >> huge_page_shift(h)) +
+			(vma->vm_pgoff >> huge_page_order(h));
+}
+
+/*
+ * Flags for MAP_PRIVATE reservations.  These are stored in the bottom
+ * bits of the reservation map pointer, which are always clear due to
+ * alignment.
+ */
+#define HPAGE_RESV_OWNER    (1UL << 0)
+#define HPAGE_RESV_UNMAPPED (1UL << 1)
+#define HPAGE_RESV_MASK (HPAGE_RESV_OWNER | HPAGE_RESV_UNMAPPED)
+
+/*
+ * These helpers are used to track how many pages are reserved for
+ * faults in a MAP_PRIVATE mapping. Only the process that called mmap()
+ * is guaranteed to have their future faults succeed.
+ *
+ * With the exception of reset_vma_resv_huge_pages() which is called at fork(),
+ * the reserve counters are updated with the hugetlb_lock held. It is safe
+ * to reset the VMA at fork() time as it is not in use yet and there is no
+ * chance of the global counters getting corrupted as a result of the values.
+ *
+ * The private mapping reservation is represented in a subtly different
+ * manner to a shared mapping.  A shared mapping has a region map associated
+ * with the underlying file, this region map represents the backing file
+ * pages which have ever had a reservation assigned which this persists even
+ * after the page is instantiated.  A private mapping has a region map
+ * associated with the original mmap which is attached to all VMAs which
+ * reference it, this region map represents those offsets which have consumed
+ * reservation ie. where pages have been instantiated.
+ */
+static unsigned long get_vma_private_data(struct vm_area_struct *vma)
+{
+	return (unsigned long)vma->vm_private_data;
+}
+
+static void set_vma_private_data(struct vm_area_struct *vma,
+							unsigned long value)
+{
+	vma->vm_private_data = (void *)value;
+}
+
+struct resv_map {
+	struct kref refs;
+	struct list_head regions;
+};
+
+struct resv_map *resv_map_alloc(void)
+{
+	struct resv_map *resv_map = kmalloc(sizeof(*resv_map), GFP_KERNEL);
+	if (!resv_map)
+		return NULL;
+
+	kref_init(&resv_map->refs);
+	INIT_LIST_HEAD(&resv_map->regions);
+
+	return resv_map;
+}
+
+void resv_map_release(struct kref *ref)
+{
+	struct resv_map *resv_map = container_of(ref, struct resv_map, refs);
+
+	/* Clear out any active regions before we release the map. */
+	region_truncate(&resv_map->regions, 0);
+	kfree(resv_map);
+}
+
+static struct resv_map *vma_resv_map(struct vm_area_struct *vma)
+{
+	VM_BUG_ON(!is_vm_hugetlb_page(vma));
+	if (!(vma->vm_flags & VM_SHARED))
+		return (struct resv_map *)(get_vma_private_data(vma) &
+							~HPAGE_RESV_MASK);
+	return 0;
+}
+
+static void set_vma_resv_map(struct vm_area_struct *vma, struct resv_map *map)
+{
+	VM_BUG_ON(!is_vm_hugetlb_page(vma));
+	VM_BUG_ON(vma->vm_flags & VM_SHARED);
+
+	set_vma_private_data(vma, (get_vma_private_data(vma) &
+				HPAGE_RESV_MASK) | (unsigned long)map);
+}
+
+static void set_vma_resv_flags(struct vm_area_struct *vma, unsigned long flags)
+{
+	VM_BUG_ON(!is_vm_hugetlb_page(vma));
+	VM_BUG_ON(vma->vm_flags & VM_SHARED);
+
+	set_vma_private_data(vma, get_vma_private_data(vma) | flags);
+}
+
+static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag)
+{
+	VM_BUG_ON(!is_vm_hugetlb_page(vma));
+
+	return (get_vma_private_data(vma) & flag) != 0;
+}
+
+/* Decrement the reserved pages in the hugepage pool by one */
+static void decrement_hugepage_resv_vma(struct hstate *h,
+			struct vm_area_struct *vma)
+{
+	if (vma->vm_flags & VM_NORESERVE)
+		return;
+
+	if (vma->vm_flags & VM_SHARED) {
+		/* Shared mappings always use reserves */
+		h->resv_huge_pages--;
+	} else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+		/*
+		 * Only the process that called mmap() has reserves for
+		 * private mappings.
+		 */
+		h->resv_huge_pages--;
+	}
+}
+
+/* Reset counters to 0 and clear all HPAGE_RESV_* flags */
+void reset_vma_resv_huge_pages(struct vm_area_struct *vma)
+{
+	VM_BUG_ON(!is_vm_hugetlb_page(vma));
+	if (!(vma->vm_flags & VM_SHARED))
+		vma->vm_private_data = (void *)0;
+}
+
+/* Returns true if the VMA has associated reserve pages */
+static int vma_has_reserves(struct vm_area_struct *vma)
+{
+	if (vma->vm_flags & VM_SHARED)
+		return 1;
+	if (is_vma_resv_set(vma, HPAGE_RESV_OWNER))
+		return 1;
+	return 0;
+}
+
+static void clear_huge_page(struct page *page,
+			unsigned long addr, unsigned long sz)
 {
 	int i;
 
 	might_sleep();
-	for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) {
+	for (i = 0; i < sz/PAGE_SIZE; i++) {
 		cond_resched();
 		clear_user_highpage(page + i, addr + i * PAGE_SIZE);
 	}
@@ -55,42 +367,44 @@ static void copy_huge_page(struct page *dst, struct page *src,
 			   unsigned long addr, struct vm_area_struct *vma)
 {
 	int i;
+	struct hstate *h = hstate_vma(vma);
 
 	might_sleep();
-	for (i = 0; i < HPAGE_SIZE/PAGE_SIZE; i++) {
+	for (i = 0; i < pages_per_huge_page(h); i++) {
 		cond_resched();
 		copy_user_highpage(dst + i, src + i, addr + i*PAGE_SIZE, vma);
 	}
 }
 
-static void enqueue_huge_page(struct page *page)
+static void enqueue_huge_page(struct hstate *h, struct page *page)
 {
 	int nid = page_to_nid(page);
-	list_add(&page->lru, &hugepage_freelists[nid]);
-	free_huge_pages++;
-	free_huge_pages_node[nid]++;
+	list_add(&page->lru, &h->hugepage_freelists[nid]);
+	h->free_huge_pages++;
+	h->free_huge_pages_node[nid]++;
 }
 
-static struct page *dequeue_huge_page(void)
+static struct page *dequeue_huge_page(struct hstate *h)
 {
 	int nid;
 	struct page *page = NULL;
 
 	for (nid = 0; nid < MAX_NUMNODES; ++nid) {
-		if (!list_empty(&hugepage_freelists[nid])) {
-			page = list_entry(hugepage_freelists[nid].next,
+		if (!list_empty(&h->hugepage_freelists[nid])) {
+			page = list_entry(h->hugepage_freelists[nid].next,
 					  struct page, lru);
 			list_del(&page->lru);
-			free_huge_pages--;
-			free_huge_pages_node[nid]--;
+			h->free_huge_pages--;
+			h->free_huge_pages_node[nid]--;
 			break;
 		}
 	}
 	return page;
 }
 
-static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma,
-				unsigned long address)
+static struct page *dequeue_huge_page_vma(struct hstate *h,
+				struct vm_area_struct *vma,
+				unsigned long address, int avoid_reserve)
 {
 	int nid;
 	struct page *page = NULL;
@@ -101,18 +415,33 @@ static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma,
 	struct zone *zone;
 	struct zoneref *z;
 
+	/*
+	 * A child process with MAP_PRIVATE mappings created by their parent
+	 * have no page reserves. This check ensures that reservations are
+	 * not "stolen". The child may still get SIGKILLed
+	 */
+	if (!vma_has_reserves(vma) &&
+			h->free_huge_pages - h->resv_huge_pages == 0)
+		return NULL;
+
+	/* If reserves cannot be used, ensure enough pages are in the pool */
+	if (avoid_reserve && h->free_huge_pages - h->resv_huge_pages == 0)
+		return NULL;
+
 	for_each_zone_zonelist_nodemask(zone, z, zonelist,
 						MAX_NR_ZONES - 1, nodemask) {
 		nid = zone_to_nid(zone);
 		if (cpuset_zone_allowed_softwall(zone, htlb_alloc_mask) &&
-		    !list_empty(&hugepage_freelists[nid])) {
-			page = list_entry(hugepage_freelists[nid].next,
+		    !list_empty(&h->hugepage_freelists[nid])) {
+			page = list_entry(h->hugepage_freelists[nid].next,
 					  struct page, lru);
 			list_del(&page->lru);
-			free_huge_pages--;
-			free_huge_pages_node[nid]--;
-			if (vma && vma->vm_flags & VM_MAYSHARE)
-				resv_huge_pages--;
+			h->free_huge_pages--;
+			h->free_huge_pages_node[nid]--;
+
+			if (!avoid_reserve)
+				decrement_hugepage_resv_vma(h, vma);
+
 			break;
 		}
 	}
@@ -120,12 +449,13 @@ static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma,
 	return page;
 }
 
-static void update_and_free_page(struct page *page)
+static void update_and_free_page(struct hstate *h, struct page *page)
 {
 	int i;
-	nr_huge_pages--;
-	nr_huge_pages_node[page_to_nid(page)]--;
-	for (i = 0; i < (HPAGE_SIZE / PAGE_SIZE); i++) {
+
+	h->nr_huge_pages--;
+	h->nr_huge_pages_node[page_to_nid(page)]--;
+	for (i = 0; i < pages_per_huge_page(h); i++) {
 		page[i].flags &= ~(1 << PG_locked | 1 << PG_error | 1 << PG_referenced |
 				1 << PG_dirty | 1 << PG_active | 1 << PG_reserved |
 				1 << PG_private | 1<< PG_writeback);
@@ -133,11 +463,27 @@ static void update_and_free_page(struct page *page)
 	set_compound_page_dtor(page, NULL);
 	set_page_refcounted(page);
 	arch_release_hugepage(page);
-	__free_pages(page, HUGETLB_PAGE_ORDER);
+	__free_pages(page, huge_page_order(h));
+}
+
+struct hstate *size_to_hstate(unsigned long size)
+{
+	struct hstate *h;
+
+	for_each_hstate(h) {
+		if (huge_page_size(h) == size)
+			return h;
+	}
+	return NULL;
 }
 
 static void free_huge_page(struct page *page)
 {
+	/*
+	 * Can't pass hstate in here because it is called from the
+	 * compound page destructor.
+	 */
+	struct hstate *h = page_hstate(page);
 	int nid = page_to_nid(page);
 	struct address_space *mapping;
 
@@ -147,12 +493,12 @@ static void free_huge_page(struct page *page)
 	INIT_LIST_HEAD(&page->lru);
 
 	spin_lock(&hugetlb_lock);
-	if (surplus_huge_pages_node[nid]) {
-		update_and_free_page(page);
-		surplus_huge_pages--;
-		surplus_huge_pages_node[nid]--;
+	if (h->surplus_huge_pages_node[nid] && huge_page_order(h) < MAX_ORDER) {
+		update_and_free_page(h, page);
+		h->surplus_huge_pages--;
+		h->surplus_huge_pages_node[nid]--;
 	} else {
-		enqueue_huge_page(page);
+		enqueue_huge_page(h, page);
 	}
 	spin_unlock(&hugetlb_lock);
 	if (mapping)
@@ -164,7 +510,7 @@ static void free_huge_page(struct page *page)
  * balanced by operating on them in a round-robin fashion.
  * Returns 1 if an adjustment was made.
  */
-static int adjust_pool_surplus(int delta)
+static int adjust_pool_surplus(struct hstate *h, int delta)
 {
 	static int prev_nid;
 	int nid = prev_nid;
@@ -177,15 +523,15 @@ static int adjust_pool_surplus(int delta)
 			nid = first_node(node_online_map);
 
 		/* To shrink on this node, there must be a surplus page */
-		if (delta < 0 && !surplus_huge_pages_node[nid])
+		if (delta < 0 && !h->surplus_huge_pages_node[nid])
 			continue;
 		/* Surplus cannot exceed the total number of pages */
-		if (delta > 0 && surplus_huge_pages_node[nid] >=
-						nr_huge_pages_node[nid])
+		if (delta > 0 && h->surplus_huge_pages_node[nid] >=
+						h->nr_huge_pages_node[nid])
 			continue;
 
-		surplus_huge_pages += delta;
-		surplus_huge_pages_node[nid] += delta;
+		h->surplus_huge_pages += delta;
+		h->surplus_huge_pages_node[nid] += delta;
 		ret = 1;
 		break;
 	} while (nid != prev_nid);
@@ -194,59 +540,74 @@ static int adjust_pool_surplus(int delta)
 	return ret;
 }
 
-static struct page *alloc_fresh_huge_page_node(int nid)
+static void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
+{
+	set_compound_page_dtor(page, free_huge_page);
+	spin_lock(&hugetlb_lock);
+	h->nr_huge_pages++;
+	h->nr_huge_pages_node[nid]++;
+	spin_unlock(&hugetlb_lock);
+	put_page(page); /* free it into the hugepage allocator */
+}
+
+static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
 {
 	struct page *page;
 
+	if (h->order >= MAX_ORDER)
+		return NULL;
+
 	page = alloc_pages_node(nid,
 		htlb_alloc_mask|__GFP_COMP|__GFP_THISNODE|
 						__GFP_REPEAT|__GFP_NOWARN,
-		HUGETLB_PAGE_ORDER);
+		huge_page_order(h));
 	if (page) {
 		if (arch_prepare_hugepage(page)) {
 			__free_pages(page, HUGETLB_PAGE_ORDER);
 			return NULL;
 		}
-		set_compound_page_dtor(page, free_huge_page);
-		spin_lock(&hugetlb_lock);
-		nr_huge_pages++;
-		nr_huge_pages_node[nid]++;
-		spin_unlock(&hugetlb_lock);
-		put_page(page); /* free it into the hugepage allocator */
+		prep_new_huge_page(h, page, nid);
 	}
 
 	return page;
 }
 
-static int alloc_fresh_huge_page(void)
+/*
+ * Use a helper variable to find the next node and then
+ * copy it back to hugetlb_next_nid afterwards:
+ * otherwise there's a window in which a racer might
+ * pass invalid nid MAX_NUMNODES to alloc_pages_node.
+ * But we don't need to use a spin_lock here: it really
+ * doesn't matter if occasionally a racer chooses the
+ * same nid as we do.  Move nid forward in the mask even
+ * if we just successfully allocated a hugepage so that
+ * the next caller gets hugepages on the next node.
+ */
+static int hstate_next_node(struct hstate *h)
+{
+	int next_nid;
+	next_nid = next_node(h->hugetlb_next_nid, node_online_map);
+	if (next_nid == MAX_NUMNODES)
+		next_nid = first_node(node_online_map);
+	h->hugetlb_next_nid = next_nid;
+	return next_nid;
+}
+
+static int alloc_fresh_huge_page(struct hstate *h)
 {
 	struct page *page;
 	int start_nid;
 	int next_nid;
 	int ret = 0;
 
-	start_nid = hugetlb_next_nid;
+	start_nid = h->hugetlb_next_nid;
 
 	do {
-		page = alloc_fresh_huge_page_node(hugetlb_next_nid);
+		page = alloc_fresh_huge_page_node(h, h->hugetlb_next_nid);
 		if (page)
 			ret = 1;
-		/*
-		 * Use a helper variable to find the next node and then
-		 * copy it back to hugetlb_next_nid afterwards:
-		 * otherwise there's a window in which a racer might
-		 * pass invalid nid MAX_NUMNODES to alloc_pages_node.
-		 * But we don't need to use a spin_lock here: it really
-		 * doesn't matter if occasionally a racer chooses the
-		 * same nid as we do.  Move nid forward in the mask even
-		 * if we just successfully allocated a hugepage so that
-		 * the next caller gets hugepages on the next node.
-		 */
-		next_nid = next_node(hugetlb_next_nid, node_online_map);
-		if (next_nid == MAX_NUMNODES)
-			next_nid = first_node(node_online_map);
-		hugetlb_next_nid = next_nid;
-	} while (!page && hugetlb_next_nid != start_nid);
+		next_nid = hstate_next_node(h);
+	} while (!page && h->hugetlb_next_nid != start_nid);
 
 	if (ret)
 		count_vm_event(HTLB_BUDDY_PGALLOC);
@@ -256,12 +617,15 @@ static int alloc_fresh_huge_page(void)
 	return ret;
 }
 
-static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma,
-						unsigned long address)
+static struct page *alloc_buddy_huge_page(struct hstate *h,
+			struct vm_area_struct *vma, unsigned long address)
 {
 	struct page *page;
 	unsigned int nid;
 
+	if (h->order >= MAX_ORDER)
+		return NULL;
+
 	/*
 	 * Assume we will successfully allocate the surplus page to
 	 * prevent racing processes from causing the surplus to exceed
@@ -286,18 +650,18 @@ static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma,
 	 * per-node value is checked there.
 	 */
 	spin_lock(&hugetlb_lock);
-	if (surplus_huge_pages >= nr_overcommit_huge_pages) {
+	if (h->surplus_huge_pages >= h->nr_overcommit_huge_pages) {
 		spin_unlock(&hugetlb_lock);
 		return NULL;
 	} else {
-		nr_huge_pages++;
-		surplus_huge_pages++;
+		h->nr_huge_pages++;
+		h->surplus_huge_pages++;
 	}
 	spin_unlock(&hugetlb_lock);
 
 	page = alloc_pages(htlb_alloc_mask|__GFP_COMP|
 					__GFP_REPEAT|__GFP_NOWARN,
-					HUGETLB_PAGE_ORDER);
+					huge_page_order(h));
 
 	spin_lock(&hugetlb_lock);
 	if (page) {
@@ -312,12 +676,12 @@ static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma,
 		/*
 		 * We incremented the global counters already
 		 */
-		nr_huge_pages_node[nid]++;
-		surplus_huge_pages_node[nid]++;
+		h->nr_huge_pages_node[nid]++;
+		h->surplus_huge_pages_node[nid]++;
 		__count_vm_event(HTLB_BUDDY_PGALLOC);
 	} else {
-		nr_huge_pages--;
-		surplus_huge_pages--;
+		h->nr_huge_pages--;
+		h->surplus_huge_pages--;
 		__count_vm_event(HTLB_BUDDY_PGALLOC_FAIL);
 	}
 	spin_unlock(&hugetlb_lock);
@@ -329,16 +693,16 @@ static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma,
  * Increase the hugetlb pool such that it can accomodate a reservation
  * of size 'delta'.
  */
-static int gather_surplus_pages(int delta)
+static int gather_surplus_pages(struct hstate *h, int delta)
 {
 	struct list_head surplus_list;
 	struct page *page, *tmp;
 	int ret, i;
 	int needed, allocated;
 
-	needed = (resv_huge_pages + delta) - free_huge_pages;
+	needed = (h->resv_huge_pages + delta) - h->free_huge_pages;
 	if (needed <= 0) {
-		resv_huge_pages += delta;
+		h->resv_huge_pages += delta;
 		return 0;
 	}
 
@@ -349,7 +713,7 @@ static int gather_surplus_pages(int delta)
 retry:
 	spin_unlock(&hugetlb_lock);
 	for (i = 0; i < needed; i++) {
-		page = alloc_buddy_huge_page(NULL, 0);
+		page = alloc_buddy_huge_page(h, NULL, 0);
 		if (!page) {
 			/*
 			 * We were not able to allocate enough pages to
@@ -370,7 +734,8 @@ retry:
 	 * because either resv_huge_pages or free_huge_pages may have changed.
 	 */
 	spin_lock(&hugetlb_lock);
-	needed = (resv_huge_pages + delta) - (free_huge_pages + allocated);
+	needed = (h->resv_huge_pages + delta) -
+			(h->free_huge_pages + allocated);
 	if (needed > 0)
 		goto retry;
 
@@ -383,7 +748,7 @@ retry:
 	 * before they are reserved.
 	 */
 	needed += allocated;
-	resv_huge_pages += delta;
+	h->resv_huge_pages += delta;
 	ret = 0;
 free:
 	/* Free the needed pages to the hugetlb pool */
@@ -391,7 +756,7 @@ free:
 		if ((--needed) < 0)
 			break;
 		list_del(&page->lru);
-		enqueue_huge_page(page);
+		enqueue_huge_page(h, page);
 	}
 
 	/* Free unnecessary surplus pages to the buddy allocator */
@@ -419,7 +784,8 @@ free:
  * allocated to satisfy the reservation must be explicitly freed if they were
  * never used.
  */
-static void return_unused_surplus_pages(unsigned long unused_resv_pages)
+static void return_unused_surplus_pages(struct hstate *h,
+					unsigned long unused_resv_pages)
 {
 	static int nid = -1;
 	struct page *page;
@@ -434,114 +800,231 @@ static void return_unused_surplus_pages(unsigned long unused_resv_pages)
 	unsigned long remaining_iterations = num_online_nodes();
 
 	/* Uncommit the reservation */
-	resv_huge_pages -= unused_resv_pages;
+	h->resv_huge_pages -= unused_resv_pages;
+
+	/* Cannot return gigantic pages currently */
+	if (h->order >= MAX_ORDER)
+		return;
 
-	nr_pages = min(unused_resv_pages, surplus_huge_pages);
+	nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
 
 	while (remaining_iterations-- && nr_pages) {
 		nid = next_node(nid, node_online_map);
 		if (nid == MAX_NUMNODES)
 			nid = first_node(node_online_map);
 
-		if (!surplus_huge_pages_node[nid])
+		if (!h->surplus_huge_pages_node[nid])
 			continue;
 
-		if (!list_empty(&hugepage_freelists[nid])) {
-			page = list_entry(hugepage_freelists[nid].next,
+		if (!list_empty(&h->hugepage_freelists[nid])) {
+			page = list_entry(h->hugepage_freelists[nid].next,
 					  struct page, lru);
 			list_del(&page->lru);
-			update_and_free_page(page);
-			free_huge_pages--;
-			free_huge_pages_node[nid]--;
-			surplus_huge_pages--;
-			surplus_huge_pages_node[nid]--;
+			update_and_free_page(h, page);
+			h->free_huge_pages--;
+			h->free_huge_pages_node[nid]--;
+			h->surplus_huge_pages--;
+			h->surplus_huge_pages_node[nid]--;
 			nr_pages--;
 			remaining_iterations = num_online_nodes();
 		}
 	}
 }
 
+/*
+ * Determine if the huge page at addr within the vma has an associated
+ * reservation.  Where it does not we will need to logically increase
+ * reservation and actually increase quota before an allocation can occur.
+ * Where any new reservation would be required the reservation change is
+ * prepared, but not committed.  Once the page has been quota'd allocated
+ * an instantiated the change should be committed via vma_commit_reservation.
+ * No action is required on failure.
+ */
+static int vma_needs_reservation(struct hstate *h,
+			struct vm_area_struct *vma, unsigned long addr)
+{
+	struct address_space *mapping = vma->vm_file->f_mapping;
+	struct inode *inode = mapping->host;
+
+	if (vma->vm_flags & VM_SHARED) {
+		pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+		return region_chg(&inode->i_mapping->private_list,
+							idx, idx + 1);
+
+	} else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+		return 1;
 
-static struct page *alloc_huge_page_shared(struct vm_area_struct *vma,
-						unsigned long addr)
+	} else  {
+		int err;
+		pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+		struct resv_map *reservations = vma_resv_map(vma);
+
+		err = region_chg(&reservations->regions, idx, idx + 1);
+		if (err < 0)
+			return err;
+		return 0;
+	}
+}
+static void vma_commit_reservation(struct hstate *h,
+			struct vm_area_struct *vma, unsigned long addr)
 {
-	struct page *page;
+	struct address_space *mapping = vma->vm_file->f_mapping;
+	struct inode *inode = mapping->host;
 
-	spin_lock(&hugetlb_lock);
-	page = dequeue_huge_page_vma(vma, addr);
-	spin_unlock(&hugetlb_lock);
-	return page ? page : ERR_PTR(-VM_FAULT_OOM);
+	if (vma->vm_flags & VM_SHARED) {
+		pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+		region_add(&inode->i_mapping->private_list, idx, idx + 1);
+
+	} else if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+		pgoff_t idx = vma_hugecache_offset(h, vma, addr);
+		struct resv_map *reservations = vma_resv_map(vma);
+
+		/* Mark this page used in the map. */
+		region_add(&reservations->regions, idx, idx + 1);
+	}
 }
 
-static struct page *alloc_huge_page_private(struct vm_area_struct *vma,
-						unsigned long addr)
+static struct page *alloc_huge_page(struct vm_area_struct *vma,
+				    unsigned long addr, int avoid_reserve)
 {
-	struct page *page = NULL;
+	struct hstate *h = hstate_vma(vma);
+	struct page *page;
+	struct address_space *mapping = vma->vm_file->f_mapping;
+	struct inode *inode = mapping->host;
+	unsigned int chg;
 
-	if (hugetlb_get_quota(vma->vm_file->f_mapping, 1))
-		return ERR_PTR(-VM_FAULT_SIGBUS);
+	/*
+	 * Processes that did not create the mapping will have no reserves and
+	 * will not have accounted against quota. Check that the quota can be
+	 * made before satisfying the allocation
+	 * MAP_NORESERVE mappings may also need pages and quota allocated
+	 * if no reserve mapping overlaps.
+	 */
+	chg = vma_needs_reservation(h, vma, addr);
+	if (chg < 0)
+		return ERR_PTR(chg);
+	if (chg)
+		if (hugetlb_get_quota(inode->i_mapping, chg))
+			return ERR_PTR(-ENOSPC);
 
 	spin_lock(&hugetlb_lock);
-	if (free_huge_pages > resv_huge_pages)
-		page = dequeue_huge_page_vma(vma, addr);
+	page = dequeue_huge_page_vma(h, vma, addr, avoid_reserve);
 	spin_unlock(&hugetlb_lock);
+
 	if (!page) {
-		page = alloc_buddy_huge_page(vma, addr);
+		page = alloc_buddy_huge_page(h, vma, addr);
 		if (!page) {
-			hugetlb_put_quota(vma->vm_file->f_mapping, 1);
+			hugetlb_put_quota(inode->i_mapping, chg);
 			return ERR_PTR(-VM_FAULT_OOM);
 		}
 	}
+
+	set_page_refcounted(page);
+	set_page_private(page, (unsigned long) mapping);
+
+	vma_commit_reservation(h, vma, addr);
+
 	return page;
 }
 
-static struct page *alloc_huge_page(struct vm_area_struct *vma,
-				    unsigned long addr)
+__attribute__((weak)) int alloc_bootmem_huge_page(struct hstate *h)
 {
-	struct page *page;
-	struct address_space *mapping = vma->vm_file->f_mapping;
+	struct huge_bootmem_page *m;
+	int nr_nodes = nodes_weight(node_online_map);
 
-	if (vma->vm_flags & VM_MAYSHARE)
-		page = alloc_huge_page_shared(vma, addr);
-	else
-		page = alloc_huge_page_private(vma, addr);
+	while (nr_nodes) {
+		void *addr;
+
+		addr = __alloc_bootmem_node_nopanic(
+				NODE_DATA(h->hugetlb_next_nid),
+				huge_page_size(h), huge_page_size(h), 0);
+
+		if (addr) {
+			/*
+			 * Use the beginning of the huge page to store the
+			 * huge_bootmem_page struct (until gather_bootmem
+			 * puts them into the mem_map).
+			 */
+			m = addr;
+			if (m)
+				goto found;
+		}
+		hstate_next_node(h);
+		nr_nodes--;
+	}
+	return 0;
+
+found:
+	BUG_ON((unsigned long)virt_to_phys(m) & (huge_page_size(h) - 1));
+	/* Put them into a private list first because mem_map is not up yet */
+	list_add(&m->list, &huge_boot_pages);
+	m->hstate = h;
+	return 1;
+}
 
-	if (!IS_ERR(page)) {
-		set_page_refcounted(page);
-		set_page_private(page, (unsigned long) mapping);
+/* Put bootmem huge pages into the standard lists after mem_map is up */
+static void __init gather_bootmem_prealloc(void)
+{
+	struct huge_bootmem_page *m;
+
+	list_for_each_entry(m, &huge_boot_pages, list) {
+		struct page *page = virt_to_page(m);
+		struct hstate *h = m->hstate;
+		__ClearPageReserved(page);
+		WARN_ON(page_count(page) != 1);
+		prep_compound_page(page, h->order);
+		prep_new_huge_page(h, page, page_to_nid(page));
 	}
-	return page;
 }
 
-static int __init hugetlb_init(void)
+static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
 {
 	unsigned long i;
 
-	if (HPAGE_SHIFT == 0)
-		return 0;
-
-	for (i = 0; i < MAX_NUMNODES; ++i)
-		INIT_LIST_HEAD(&hugepage_freelists[i]);
+	for (i = 0; i < h->max_huge_pages; ++i) {
+		if (h->order >= MAX_ORDER) {
+			if (!alloc_bootmem_huge_page(h))
+				break;
+		} else if (!alloc_fresh_huge_page(h))
+			break;
+	}
+	h->max_huge_pages = i;
+}
 
-	hugetlb_next_nid = first_node(node_online_map);
+static void __init hugetlb_init_hstates(void)
+{
+	struct hstate *h;
 
-	for (i = 0; i < max_huge_pages; ++i) {
-		if (!alloc_fresh_huge_page())
-			break;
+	for_each_hstate(h) {
+		/* oversize hugepages were init'ed in early boot */
+		if (h->order < MAX_ORDER)
+			hugetlb_hstate_alloc_pages(h);
 	}
-	max_huge_pages = free_huge_pages = nr_huge_pages = i;
-	printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages);
-	return 0;
 }
-module_init(hugetlb_init);
 
-static int __init hugetlb_setup(char *s)
+static char * __init memfmt(char *buf, unsigned long n)
 {
-	if (sscanf(s, "%lu", &max_huge_pages) <= 0)
-		max_huge_pages = 0;
-	return 1;
+	if (n >= (1UL << 30))
+		sprintf(buf, "%lu GB", n >> 30);
+	else if (n >= (1UL << 20))
+		sprintf(buf, "%lu MB", n >> 20);
+	else
+		sprintf(buf, "%lu KB", n >> 10);
+	return buf;
+}
+
+static void __init report_hugepages(void)
+{
+	struct hstate *h;
+
+	for_each_hstate(h) {
+		char buf[32];
+		printk(KERN_INFO "HugeTLB registered %s page size, "
+				 "pre-allocated %ld pages\n",
+			memfmt(buf, huge_page_size(h)),
+			h->free_huge_pages);
+	}
 }
-__setup("hugepages=", hugetlb_setup);
 
 static unsigned int cpuset_mems_nr(unsigned int *array)
 {
@@ -556,35 +1039,42 @@ static unsigned int cpuset_mems_nr(unsigned int *array)
 
 #ifdef CONFIG_SYSCTL
 #ifdef CONFIG_HIGHMEM
-static void try_to_free_low(unsigned long count)
+static void try_to_free_low(struct hstate *h, unsigned long count)
 {
 	int i;
 
+	if (h->order >= MAX_ORDER)
+		return;
+
 	for (i = 0; i < MAX_NUMNODES; ++i) {
 		struct page *page, *next;
-		list_for_each_entry_safe(page, next, &hugepage_freelists[i], lru) {
-			if (count >= nr_huge_pages)
+		struct list_head *freel = &h->hugepage_freelists[i];
+		list_for_each_entry_safe(page, next, freel, lru) {
+			if (count >= h->nr_huge_pages)
 				return;
 			if (PageHighMem(page))
 				continue;
 			list_del(&page->lru);
-			update_and_free_page(page);
-			free_huge_pages--;
-			free_huge_pages_node[page_to_nid(page)]--;
+			update_and_free_page(h, page);
+			h->free_huge_pages--;
+			h->free_huge_pages_node[page_to_nid(page)]--;
 		}
 	}
 }
 #else
-static inline void try_to_free_low(unsigned long count)
+static inline void try_to_free_low(struct hstate *h, unsigned long count)
 {
 }
 #endif
 
-#define persistent_huge_pages (nr_huge_pages - surplus_huge_pages)
-static unsigned long set_max_huge_pages(unsigned long count)
+#define persistent_huge_pages(h) (h->nr_huge_pages - h->surplus_huge_pages)
+static unsigned long set_max_huge_pages(struct hstate *h, unsigned long count)
 {
 	unsigned long min_count, ret;
 
+	if (h->order >= MAX_ORDER)
+		return h->max_huge_pages;
+
 	/*
 	 * Increase the pool size
 	 * First take pages out of surplus state.  Then make up the
@@ -597,20 +1087,19 @@ static unsigned long set_max_huge_pages(unsigned long count)
 	 * within all the constraints specified by the sysctls.
 	 */
 	spin_lock(&hugetlb_lock);
-	while (surplus_huge_pages && count > persistent_huge_pages) {
-		if (!adjust_pool_surplus(-1))
+	while (h->surplus_huge_pages && count > persistent_huge_pages(h)) {
+		if (!adjust_pool_surplus(h, -1))
 			break;
 	}
 
-	while (count > persistent_huge_pages) {
-		int ret;
+	while (count > persistent_huge_pages(h)) {
 		/*
 		 * If this allocation races such that we no longer need the
 		 * page, free_huge_page will handle it by freeing the page
 		 * and reducing the surplus.
 		 */
 		spin_unlock(&hugetlb_lock);
-		ret = alloc_fresh_huge_page();
+		ret = alloc_fresh_huge_page(h);
 		spin_lock(&hugetlb_lock);
 		if (!ret)
 			goto out;
@@ -632,31 +1121,288 @@ static unsigned long set_max_huge_pages(unsigned long count)
 	 * and won't grow the pool anywhere else. Not until one of the
 	 * sysctls are changed, or the surplus pages go out of use.
 	 */
-	min_count = resv_huge_pages + nr_huge_pages - free_huge_pages;
+	min_count = h->resv_huge_pages + h->nr_huge_pages - h->free_huge_pages;
 	min_count = max(count, min_count);
-	try_to_free_low(min_count);
-	while (min_count < persistent_huge_pages) {
-		struct page *page = dequeue_huge_page();
+	try_to_free_low(h, min_count);
+	while (min_count < persistent_huge_pages(h)) {
+		struct page *page = dequeue_huge_page(h);
 		if (!page)
 			break;
-		update_and_free_page(page);
+		update_and_free_page(h, page);
 	}
-	while (count < persistent_huge_pages) {
-		if (!adjust_pool_surplus(1))
+	while (count < persistent_huge_pages(h)) {
+		if (!adjust_pool_surplus(h, 1))
 			break;
 	}
 out:
-	ret = persistent_huge_pages;
+	ret = persistent_huge_pages(h);
 	spin_unlock(&hugetlb_lock);
 	return ret;
 }
 
+#define HSTATE_ATTR_RO(_name) \
+	static struct kobj_attribute _name##_attr = __ATTR_RO(_name)
+
+#define HSTATE_ATTR(_name) \
+	static struct kobj_attribute _name##_attr = \
+		__ATTR(_name, 0644, _name##_show, _name##_store)
+
+static struct kobject *hugepages_kobj;
+static struct kobject *hstate_kobjs[HUGE_MAX_HSTATE];
+
+static struct hstate *kobj_to_hstate(struct kobject *kobj)
+{
+	int i;
+	for (i = 0; i < HUGE_MAX_HSTATE; i++)
+		if (hstate_kobjs[i] == kobj)
+			return &hstates[i];
+	BUG();
+	return NULL;
+}
+
+static ssize_t nr_hugepages_show(struct kobject *kobj,
+					struct kobj_attribute *attr, char *buf)
+{
+	struct hstate *h = kobj_to_hstate(kobj);
+	return sprintf(buf, "%lu\n", h->nr_huge_pages);
+}
+static ssize_t nr_hugepages_store(struct kobject *kobj,
+		struct kobj_attribute *attr, const char *buf, size_t count)
+{
+	int err;
+	unsigned long input;
+	struct hstate *h = kobj_to_hstate(kobj);
+
+	err = strict_strtoul(buf, 10, &input);
+	if (err)
+		return 0;
+
+	h->max_huge_pages = set_max_huge_pages(h, input);
+
+	return count;
+}
+HSTATE_ATTR(nr_hugepages);
+
+static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
+					struct kobj_attribute *attr, char *buf)
+{
+	struct hstate *h = kobj_to_hstate(kobj);
+	return sprintf(buf, "%lu\n", h->nr_overcommit_huge_pages);
+}
+static ssize_t nr_overcommit_hugepages_store(struct kobject *kobj,
+		struct kobj_attribute *attr, const char *buf, size_t count)
+{
+	int err;
+	unsigned long input;
+	struct hstate *h = kobj_to_hstate(kobj);
+
+	err = strict_strtoul(buf, 10, &input);
+	if (err)
+		return 0;
+
+	spin_lock(&hugetlb_lock);
+	h->nr_overcommit_huge_pages = input;
+	spin_unlock(&hugetlb_lock);
+
+	return count;
+}
+HSTATE_ATTR(nr_overcommit_hugepages);
+
+static ssize_t free_hugepages_show(struct kobject *kobj,
+					struct kobj_attribute *attr, char *buf)
+{
+	struct hstate *h = kobj_to_hstate(kobj);
+	return sprintf(buf, "%lu\n", h->free_huge_pages);
+}
+HSTATE_ATTR_RO(free_hugepages);
+
+static ssize_t resv_hugepages_show(struct kobject *kobj,
+					struct kobj_attribute *attr, char *buf)
+{
+	struct hstate *h = kobj_to_hstate(kobj);
+	return sprintf(buf, "%lu\n", h->resv_huge_pages);
+}
+HSTATE_ATTR_RO(resv_hugepages);
+
+static ssize_t surplus_hugepages_show(struct kobject *kobj,
+					struct kobj_attribute *attr, char *buf)
+{
+	struct hstate *h = kobj_to_hstate(kobj);
+	return sprintf(buf, "%lu\n", h->surplus_huge_pages);
+}
+HSTATE_ATTR_RO(surplus_hugepages);
+
+static struct attribute *hstate_attrs[] = {
+	&nr_hugepages_attr.attr,
+	&nr_overcommit_hugepages_attr.attr,
+	&free_hugepages_attr.attr,
+	&resv_hugepages_attr.attr,
+	&surplus_hugepages_attr.attr,
+	NULL,
+};
+
+static struct attribute_group hstate_attr_group = {
+	.attrs = hstate_attrs,
+};
+
+static int __init hugetlb_sysfs_add_hstate(struct hstate *h)
+{
+	int retval;
+
+	hstate_kobjs[h - hstates] = kobject_create_and_add(h->name,
+							hugepages_kobj);
+	if (!hstate_kobjs[h - hstates])
+		return -ENOMEM;
+
+	retval = sysfs_create_group(hstate_kobjs[h - hstates],
+							&hstate_attr_group);
+	if (retval)
+		kobject_put(hstate_kobjs[h - hstates]);
+
+	return retval;
+}
+
+static void __init hugetlb_sysfs_init(void)
+{
+	struct hstate *h;
+	int err;
+
+	hugepages_kobj = kobject_create_and_add("hugepages", mm_kobj);
+	if (!hugepages_kobj)
+		return;
+
+	for_each_hstate(h) {
+		err = hugetlb_sysfs_add_hstate(h);
+		if (err)
+			printk(KERN_ERR "Hugetlb: Unable to add hstate %s",
+								h->name);
+	}
+}
+
+static void __exit hugetlb_exit(void)
+{
+	struct hstate *h;
+
+	for_each_hstate(h) {
+		kobject_put(hstate_kobjs[h - hstates]);
+	}
+
+	kobject_put(hugepages_kobj);
+}
+module_exit(hugetlb_exit);
+
+static int __init hugetlb_init(void)
+{
+	BUILD_BUG_ON(HPAGE_SHIFT == 0);
+
+	if (!size_to_hstate(default_hstate_size)) {
+		default_hstate_size = HPAGE_SIZE;
+		if (!size_to_hstate(default_hstate_size))
+			hugetlb_add_hstate(HUGETLB_PAGE_ORDER);
+	}
+	default_hstate_idx = size_to_hstate(default_hstate_size) - hstates;
+	if (default_hstate_max_huge_pages)
+		default_hstate.max_huge_pages = default_hstate_max_huge_pages;
+
+	hugetlb_init_hstates();
+
+	gather_bootmem_prealloc();
+
+	report_hugepages();
+
+	hugetlb_sysfs_init();
+
+	return 0;
+}
+module_init(hugetlb_init);
+
+/* Should be called on processing a hugepagesz=... option */
+void __init hugetlb_add_hstate(unsigned order)
+{
+	struct hstate *h;
+	unsigned long i;
+
+	if (size_to_hstate(PAGE_SIZE << order)) {
+		printk(KERN_WARNING "hugepagesz= specified twice, ignoring\n");
+		return;
+	}
+	BUG_ON(max_hstate >= HUGE_MAX_HSTATE);
+	BUG_ON(order == 0);
+	h = &hstates[max_hstate++];
+	h->order = order;
+	h->mask = ~((1ULL << (order + PAGE_SHIFT)) - 1);
+	h->nr_huge_pages = 0;
+	h->free_huge_pages = 0;
+	for (i = 0; i < MAX_NUMNODES; ++i)
+		INIT_LIST_HEAD(&h->hugepage_freelists[i]);
+	h->hugetlb_next_nid = first_node(node_online_map);
+	snprintf(h->name, HSTATE_NAME_LEN, "hugepages-%lukB",
+					huge_page_size(h)/1024);
+
+	parsed_hstate = h;
+}
+
+static int __init hugetlb_nrpages_setup(char *s)
+{
+	unsigned long *mhp;
+	static unsigned long *last_mhp;
+
+	/*
+	 * !max_hstate means we haven't parsed a hugepagesz= parameter yet,
+	 * so this hugepages= parameter goes to the "default hstate".
+	 */
+	if (!max_hstate)
+		mhp = &default_hstate_max_huge_pages;
+	else
+		mhp = &parsed_hstate->max_huge_pages;
+
+	if (mhp == last_mhp) {
+		printk(KERN_WARNING "hugepages= specified twice without "
+			"interleaving hugepagesz=, ignoring\n");
+		return 1;
+	}
+
+	if (sscanf(s, "%lu", mhp) <= 0)
+		*mhp = 0;
+
+	/*
+	 * Global state is always initialized later in hugetlb_init.
+	 * But we need to allocate >= MAX_ORDER hstates here early to still
+	 * use the bootmem allocator.
+	 */
+	if (max_hstate && parsed_hstate->order >= MAX_ORDER)
+		hugetlb_hstate_alloc_pages(parsed_hstate);
+
+	last_mhp = mhp;
+
+	return 1;
+}
+__setup("hugepages=", hugetlb_nrpages_setup);
+
+static int __init hugetlb_default_setup(char *s)
+{
+	default_hstate_size = memparse(s, &s);
+	return 1;
+}
+__setup("default_hugepagesz=", hugetlb_default_setup);
+
 int hugetlb_sysctl_handler(struct ctl_table *table, int write,
 			   struct file *file, void __user *buffer,
 			   size_t *length, loff_t *ppos)
 {
+	struct hstate *h = &default_hstate;
+	unsigned long tmp;
+
+	if (!write)
+		tmp = h->max_huge_pages;
+
+	table->data = &tmp;
+	table->maxlen = sizeof(unsigned long);
 	proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
-	max_huge_pages = set_max_huge_pages(max_huge_pages);
+
+	if (write)
+		h->max_huge_pages = set_max_huge_pages(h, tmp);
+
 	return 0;
 }
 
@@ -676,10 +1422,22 @@ int hugetlb_overcommit_handler(struct ctl_table *table, int write,
 			struct file *file, void __user *buffer,
 			size_t *length, loff_t *ppos)
 {
+	struct hstate *h = &default_hstate;
+	unsigned long tmp;
+
+	if (!write)
+		tmp = h->nr_overcommit_huge_pages;
+
+	table->data = &tmp;
+	table->maxlen = sizeof(unsigned long);
 	proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
-	spin_lock(&hugetlb_lock);
-	nr_overcommit_huge_pages = sysctl_overcommit_huge_pages;
-	spin_unlock(&hugetlb_lock);
+
+	if (write) {
+		spin_lock(&hugetlb_lock);
+		h->nr_overcommit_huge_pages = tmp;
+		spin_unlock(&hugetlb_lock);
+	}
+
 	return 0;
 }
 
@@ -687,34 +1445,118 @@ int hugetlb_overcommit_handler(struct ctl_table *table, int write,
 
 int hugetlb_report_meminfo(char *buf)
 {
+	struct hstate *h = &default_hstate;
 	return sprintf(buf,
 			"HugePages_Total: %5lu\n"
 			"HugePages_Free:  %5lu\n"
 			"HugePages_Rsvd:  %5lu\n"
 			"HugePages_Surp:  %5lu\n"
 			"Hugepagesize:    %5lu kB\n",
-			nr_huge_pages,
-			free_huge_pages,
-			resv_huge_pages,
-			surplus_huge_pages,
-			HPAGE_SIZE/1024);
+			h->nr_huge_pages,
+			h->free_huge_pages,
+			h->resv_huge_pages,
+			h->surplus_huge_pages,
+			1UL << (huge_page_order(h) + PAGE_SHIFT - 10));
 }
 
 int hugetlb_report_node_meminfo(int nid, char *buf)
 {
+	struct hstate *h = &default_hstate;
 	return sprintf(buf,
 		"Node %d HugePages_Total: %5u\n"
 		"Node %d HugePages_Free:  %5u\n"
 		"Node %d HugePages_Surp:  %5u\n",
-		nid, nr_huge_pages_node[nid],
-		nid, free_huge_pages_node[nid],
-		nid, surplus_huge_pages_node[nid]);
+		nid, h->nr_huge_pages_node[nid],
+		nid, h->free_huge_pages_node[nid],
+		nid, h->surplus_huge_pages_node[nid]);
 }
 
 /* Return the number pages of memory we physically have, in PAGE_SIZE units. */
 unsigned long hugetlb_total_pages(void)
 {
-	return nr_huge_pages * (HPAGE_SIZE / PAGE_SIZE);
+	struct hstate *h = &default_hstate;
+	return h->nr_huge_pages * pages_per_huge_page(h);
+}
+
+static int hugetlb_acct_memory(struct hstate *h, long delta)
+{
+	int ret = -ENOMEM;
+
+	spin_lock(&hugetlb_lock);
+	/*
+	 * When cpuset is configured, it breaks the strict hugetlb page
+	 * reservation as the accounting is done on a global variable. Such
+	 * reservation is completely rubbish in the presence of cpuset because
+	 * the reservation is not checked against page availability for the
+	 * current cpuset. Application can still potentially OOM'ed by kernel
+	 * with lack of free htlb page in cpuset that the task is in.
+	 * Attempt to enforce strict accounting with cpuset is almost
+	 * impossible (or too ugly) because cpuset is too fluid that
+	 * task or memory node can be dynamically moved between cpusets.
+	 *
+	 * The change of semantics for shared hugetlb mapping with cpuset is
+	 * undesirable. However, in order to preserve some of the semantics,
+	 * we fall back to check against current free page availability as
+	 * a best attempt and hopefully to minimize the impact of changing
+	 * semantics that cpuset has.
+	 */
+	if (delta > 0) {
+		if (gather_surplus_pages(h, delta) < 0)
+			goto out;
+
+		if (delta > cpuset_mems_nr(h->free_huge_pages_node)) {
+			return_unused_surplus_pages(h, delta);
+			goto out;
+		}
+	}
+
+	ret = 0;
+	if (delta < 0)
+		return_unused_surplus_pages(h, (unsigned long) -delta);
+
+out:
+	spin_unlock(&hugetlb_lock);
+	return ret;
+}
+
+static void hugetlb_vm_op_open(struct vm_area_struct *vma)
+{
+	struct resv_map *reservations = vma_resv_map(vma);
+
+	/*
+	 * This new VMA should share its siblings reservation map if present.
+	 * The VMA will only ever have a valid reservation map pointer where
+	 * it is being copied for another still existing VMA.  As that VMA
+	 * has a reference to the reservation map it cannot dissappear until
+	 * after this open call completes.  It is therefore safe to take a
+	 * new reference here without additional locking.
+	 */
+	if (reservations)
+		kref_get(&reservations->refs);
+}
+
+static void hugetlb_vm_op_close(struct vm_area_struct *vma)
+{
+	struct hstate *h = hstate_vma(vma);
+	struct resv_map *reservations = vma_resv_map(vma);
+	unsigned long reserve;
+	unsigned long start;
+	unsigned long end;
+
+	if (reservations) {
+		start = vma_hugecache_offset(h, vma, vma->vm_start);
+		end = vma_hugecache_offset(h, vma, vma->vm_end);
+
+		reserve = (end - start) -
+			region_count(&reservations->regions, start, end);
+
+		kref_put(&reservations->refs, resv_map_release);
+
+		if (reserve) {
+			hugetlb_acct_memory(h, -reserve);
+			hugetlb_put_quota(vma->vm_file->f_mapping, reserve);
+		}
+	}
 }
 
 /*
@@ -731,6 +1573,8 @@ static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
 
 struct vm_operations_struct hugetlb_vm_ops = {
 	.fault = hugetlb_vm_op_fault,
+	.open = hugetlb_vm_op_open,
+	.close = hugetlb_vm_op_close,
 };
 
 static pte_t make_huge_pte(struct vm_area_struct *vma, struct page *page,
@@ -769,14 +1613,16 @@ int copy_hugetlb_page_range(struct mm_struct *dst, struct mm_struct *src,
 	struct page *ptepage;
 	unsigned long addr;
 	int cow;
+	struct hstate *h = hstate_vma(vma);
+	unsigned long sz = huge_page_size(h);
 
 	cow = (vma->vm_flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
 
-	for (addr = vma->vm_start; addr < vma->vm_end; addr += HPAGE_SIZE) {
+	for (addr = vma->vm_start; addr < vma->vm_end; addr += sz) {
 		src_pte = huge_pte_offset(src, addr);
 		if (!src_pte)
 			continue;
-		dst_pte = huge_pte_alloc(dst, addr);
+		dst_pte = huge_pte_alloc(dst, addr, sz);
 		if (!dst_pte)
 			goto nomem;
 
@@ -804,7 +1650,7 @@ nomem:
 }
 
 void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
-			    unsigned long end)
+			    unsigned long end, struct page *ref_page)
 {
 	struct mm_struct *mm = vma->vm_mm;
 	unsigned long address;
@@ -812,6 +1658,9 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
 	pte_t pte;
 	struct page *page;
 	struct page *tmp;
+	struct hstate *h = hstate_vma(vma);
+	unsigned long sz = huge_page_size(h);
+
 	/*
 	 * A page gathering list, protected by per file i_mmap_lock. The
 	 * lock is used to avoid list corruption from multiple unmapping
@@ -820,11 +1669,11 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
 	LIST_HEAD(page_list);
 
 	WARN_ON(!is_vm_hugetlb_page(vma));
-	BUG_ON(start & ~HPAGE_MASK);
-	BUG_ON(end & ~HPAGE_MASK);
+	BUG_ON(start & ~huge_page_mask(h));
+	BUG_ON(end & ~huge_page_mask(h));
 
 	spin_lock(&mm->page_table_lock);
-	for (address = start; address < end; address += HPAGE_SIZE) {
+	for (address = start; address < end; address += sz) {
 		ptep = huge_pte_offset(mm, address);
 		if (!ptep)
 			continue;
@@ -832,6 +1681,27 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
 		if (huge_pmd_unshare(mm, &address, ptep))
 			continue;
 
+		/*
+		 * If a reference page is supplied, it is because a specific
+		 * page is being unmapped, not a range. Ensure the page we
+		 * are about to unmap is the actual page of interest.
+		 */
+		if (ref_page) {
+			pte = huge_ptep_get(ptep);
+			if (huge_pte_none(pte))
+				continue;
+			page = pte_page(pte);
+			if (page != ref_page)
+				continue;
+
+			/*
+			 * Mark the VMA as having unmapped its page so that
+			 * future faults in this VMA will fail rather than
+			 * looking like data was lost
+			 */
+			set_vma_resv_flags(vma, HPAGE_RESV_UNMAPPED);
+		}
+
 		pte = huge_ptep_get_and_clear(mm, address, ptep);
 		if (huge_pte_none(pte))
 			continue;
@@ -850,31 +1720,71 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
 }
 
 void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
-			  unsigned long end)
+			  unsigned long end, struct page *ref_page)
 {
+	spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
+	__unmap_hugepage_range(vma, start, end, ref_page);
+	spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
+}
+
+/*
+ * This is called when the original mapper is failing to COW a MAP_PRIVATE
+ * mappping it owns the reserve page for. The intention is to unmap the page
+ * from other VMAs and let the children be SIGKILLed if they are faulting the
+ * same region.
+ */
+int unmap_ref_private(struct mm_struct *mm,
+					struct vm_area_struct *vma,
+					struct page *page,
+					unsigned long address)
+{
+	struct vm_area_struct *iter_vma;
+	struct address_space *mapping;
+	struct prio_tree_iter iter;
+	pgoff_t pgoff;
+
 	/*
-	 * It is undesirable to test vma->vm_file as it should be non-null
-	 * for valid hugetlb area. However, vm_file will be NULL in the error
-	 * cleanup path of do_mmap_pgoff. When hugetlbfs ->mmap method fails,
-	 * do_mmap_pgoff() nullifies vma->vm_file before calling this function
-	 * to clean up. Since no pte has actually been setup, it is safe to
-	 * do nothing in this case.
+	 * vm_pgoff is in PAGE_SIZE units, hence the different calculation
+	 * from page cache lookup which is in HPAGE_SIZE units.
 	 */
-	if (vma->vm_file) {
-		spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
-		__unmap_hugepage_range(vma, start, end);
-		spin_unlock(&vma->vm_file->f_mapping->i_mmap_lock);
+	address = address & huge_page_mask(hstate_vma(vma));
+	pgoff = ((address - vma->vm_start) >> PAGE_SHIFT)
+		+ (vma->vm_pgoff >> PAGE_SHIFT);
+	mapping = (struct address_space *)page_private(page);
+
+	vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
+		/* Do not unmap the current VMA */
+		if (iter_vma == vma)
+			continue;
+
+		/*
+		 * Unmap the page from other VMAs without their own reserves.
+		 * They get marked to be SIGKILLed if they fault in these
+		 * areas. This is because a future no-page fault on this VMA
+		 * could insert a zeroed page instead of the data existing
+		 * from the time of fork. This would look like data corruption
+		 */
+		if (!is_vma_resv_set(iter_vma, HPAGE_RESV_OWNER))
+			unmap_hugepage_range(iter_vma,
+				address, address + HPAGE_SIZE,
+				page);
 	}
+
+	return 1;
 }
 
 static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
-			unsigned long address, pte_t *ptep, pte_t pte)
+			unsigned long address, pte_t *ptep, pte_t pte,
+			struct page *pagecache_page)
 {
+	struct hstate *h = hstate_vma(vma);
 	struct page *old_page, *new_page;
 	int avoidcopy;
+	int outside_reserve = 0;
 
 	old_page = pte_page(pte);
 
+retry_avoidcopy:
 	/* If no-one else is actually using this page, avoid the copy
 	 * and just make the page writable */
 	avoidcopy = (page_count(old_page) == 1);
@@ -883,11 +1793,43 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
 		return 0;
 	}
 
+	/*
+	 * If the process that created a MAP_PRIVATE mapping is about to
+	 * perform a COW due to a shared page count, attempt to satisfy
+	 * the allocation without using the existing reserves. The pagecache
+	 * page is used to determine if the reserve at this address was
+	 * consumed or not. If reserves were used, a partial faulted mapping
+	 * at the time of fork() could consume its reserves on COW instead
+	 * of the full address range.
+	 */
+	if (!(vma->vm_flags & VM_SHARED) &&
+			is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
+			old_page != pagecache_page)
+		outside_reserve = 1;
+
 	page_cache_get(old_page);
-	new_page = alloc_huge_page(vma, address);
+	new_page = alloc_huge_page(vma, address, outside_reserve);
 
 	if (IS_ERR(new_page)) {
 		page_cache_release(old_page);
+
+		/*
+		 * If a process owning a MAP_PRIVATE mapping fails to COW,
+		 * it is due to references held by a child and an insufficient
+		 * huge page pool. To guarantee the original mappers
+		 * reliability, unmap the page from child processes. The child
+		 * may get SIGKILLed if it later faults.
+		 */
+		if (outside_reserve) {
+			BUG_ON(huge_pte_none(pte));
+			if (unmap_ref_private(mm, vma, old_page, address)) {
+				BUG_ON(page_count(old_page) != 1);
+				BUG_ON(huge_pte_none(pte));
+				goto retry_avoidcopy;
+			}
+			WARN_ON_ONCE(1);
+		}
+
 		return -PTR_ERR(new_page);
 	}
 
@@ -896,7 +1838,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
 	__SetPageUptodate(new_page);
 	spin_lock(&mm->page_table_lock);
 
-	ptep = huge_pte_offset(mm, address & HPAGE_MASK);
+	ptep = huge_pte_offset(mm, address & huge_page_mask(h));
 	if (likely(pte_same(huge_ptep_get(ptep), pte))) {
 		/* Break COW */
 		huge_ptep_clear_flush(vma, address, ptep);
@@ -910,19 +1852,44 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
 	return 0;
 }
 
+/* Return the pagecache page at a given address within a VMA */
+static struct page *hugetlbfs_pagecache_page(struct hstate *h,
+			struct vm_area_struct *vma, unsigned long address)
+{
+	struct address_space *mapping;
+	pgoff_t idx;
+
+	mapping = vma->vm_file->f_mapping;
+	idx = vma_hugecache_offset(h, vma, address);
+
+	return find_lock_page(mapping, idx);
+}
+
 static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			unsigned long address, pte_t *ptep, int write_access)
 {
+	struct hstate *h = hstate_vma(vma);
 	int ret = VM_FAULT_SIGBUS;
-	unsigned long idx;
+	pgoff_t idx;
 	unsigned long size;
 	struct page *page;
 	struct address_space *mapping;
 	pte_t new_pte;
 
+	/*
+	 * Currently, we are forced to kill the process in the event the
+	 * original mapper has unmapped pages from the child due to a failed
+	 * COW. Warn that such a situation has occured as it may not be obvious
+	 */
+	if (is_vma_resv_set(vma, HPAGE_RESV_UNMAPPED)) {
+		printk(KERN_WARNING
+			"PID %d killed due to inadequate hugepage pool\n",
+			current->pid);
+		return ret;
+	}
+
 	mapping = vma->vm_file->f_mapping;
-	idx = ((address - vma->vm_start) >> HPAGE_SHIFT)
-		+ (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
+	idx = vma_hugecache_offset(h, vma, address);
 
 	/*
 	 * Use page lock to guard against racing truncation
@@ -931,15 +1898,15 @@ static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
 retry:
 	page = find_lock_page(mapping, idx);
 	if (!page) {
-		size = i_size_read(mapping->host) >> HPAGE_SHIFT;
+		size = i_size_read(mapping->host) >> huge_page_shift(h);
 		if (idx >= size)
 			goto out;
-		page = alloc_huge_page(vma, address);
+		page = alloc_huge_page(vma, address, 0);
 		if (IS_ERR(page)) {
 			ret = -PTR_ERR(page);
 			goto out;
 		}
-		clear_huge_page(page, address);
+		clear_huge_page(page, address, huge_page_size(h));
 		__SetPageUptodate(page);
 
 		if (vma->vm_flags & VM_SHARED) {
@@ -955,14 +1922,14 @@ retry:
 			}
 
 			spin_lock(&inode->i_lock);
-			inode->i_blocks += BLOCKS_PER_HUGEPAGE;
+			inode->i_blocks += blocks_per_huge_page(h);
 			spin_unlock(&inode->i_lock);
 		} else
 			lock_page(page);
 	}
 
 	spin_lock(&mm->page_table_lock);
-	size = i_size_read(mapping->host) >> HPAGE_SHIFT;
+	size = i_size_read(mapping->host) >> huge_page_shift(h);
 	if (idx >= size)
 		goto backout;
 
@@ -976,7 +1943,7 @@ retry:
 
 	if (write_access && !(vma->vm_flags & VM_SHARED)) {
 		/* Optimization, do the COW without a second fault */
-		ret = hugetlb_cow(mm, vma, address, ptep, new_pte);
+		ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page);
 	}
 
 	spin_unlock(&mm->page_table_lock);
@@ -998,8 +1965,9 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	pte_t entry;
 	int ret;
 	static DEFINE_MUTEX(hugetlb_instantiation_mutex);
+	struct hstate *h = hstate_vma(vma);
 
-	ptep = huge_pte_alloc(mm, address);
+	ptep = huge_pte_alloc(mm, address, huge_page_size(h));
 	if (!ptep)
 		return VM_FAULT_OOM;
 
@@ -1021,14 +1989,30 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
 	spin_lock(&mm->page_table_lock);
 	/* Check for a racing update before calling hugetlb_cow */
 	if (likely(pte_same(entry, huge_ptep_get(ptep))))
-		if (write_access && !pte_write(entry))
-			ret = hugetlb_cow(mm, vma, address, ptep, entry);
+		if (write_access && !pte_write(entry)) {
+			struct page *page;
+			page = hugetlbfs_pagecache_page(h, vma, address);
+			ret = hugetlb_cow(mm, vma, address, ptep, entry, page);
+			if (page) {
+				unlock_page(page);
+				put_page(page);
+			}
+		}
 	spin_unlock(&mm->page_table_lock);
 	mutex_unlock(&hugetlb_instantiation_mutex);
 
 	return ret;
 }
 
+/* Can be overriden by architectures */
+__attribute__((weak)) struct page *
+follow_huge_pud(struct mm_struct *mm, unsigned long address,
+	       pud_t *pud, int write)
+{
+	BUG();
+	return NULL;
+}
+
 int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			struct page **pages, struct vm_area_struct **vmas,
 			unsigned long *position, int *length, int i,
@@ -1037,6 +2021,7 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	unsigned long pfn_offset;
 	unsigned long vaddr = *position;
 	int remainder = *length;
+	struct hstate *h = hstate_vma(vma);
 
 	spin_lock(&mm->page_table_lock);
 	while (vaddr < vma->vm_end && remainder) {
@@ -1048,7 +2033,7 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 		 * each hugepage.  We have to make * sure we get the
 		 * first, for the page indexing below to work.
 		 */
-		pte = huge_pte_offset(mm, vaddr & HPAGE_MASK);
+		pte = huge_pte_offset(mm, vaddr & huge_page_mask(h));
 
 		if (!pte || huge_pte_none(huge_ptep_get(pte)) ||
 		    (write && !pte_write(huge_ptep_get(pte)))) {
@@ -1066,7 +2051,7 @@ int follow_hugetlb_page(struct mm_struct *mm, struct vm_area_struct *vma,
 			break;
 		}
 
-		pfn_offset = (vaddr & ~HPAGE_MASK) >> PAGE_SHIFT;
+		pfn_offset = (vaddr & ~huge_page_mask(h)) >> PAGE_SHIFT;
 		page = pte_page(huge_ptep_get(pte));
 same_page:
 		if (pages) {
@@ -1082,7 +2067,7 @@ same_page:
 		--remainder;
 		++i;
 		if (vaddr < vma->vm_end && remainder &&
-				pfn_offset < HPAGE_SIZE/PAGE_SIZE) {
+				pfn_offset < pages_per_huge_page(h)) {
 			/*
 			 * We use pfn_offset to avoid touching the pageframes
 			 * of this compound page.
@@ -1104,13 +2089,14 @@ void hugetlb_change_protection(struct vm_area_struct *vma,
 	unsigned long start = address;
 	pte_t *ptep;
 	pte_t pte;
+	struct hstate *h = hstate_vma(vma);
 
 	BUG_ON(address >= end);
 	flush_cache_range(vma, address, end);
 
 	spin_lock(&vma->vm_file->f_mapping->i_mmap_lock);
 	spin_lock(&mm->page_table_lock);
-	for (; address < end; address += HPAGE_SIZE) {
+	for (; address < end; address += huge_page_size(h)) {
 		ptep = huge_pte_offset(mm, address);
 		if (!ptep)
 			continue;
@@ -1128,195 +2114,59 @@ void hugetlb_change_protection(struct vm_area_struct *vma,
 	flush_tlb_range(vma, start, end);
 }
 
-struct file_region {
-	struct list_head link;
-	long from;
-	long to;
-};
-
-static long region_add(struct list_head *head, long f, long t)
-{
-	struct file_region *rg, *nrg, *trg;
-
-	/* Locate the region we are either in or before. */
-	list_for_each_entry(rg, head, link)
-		if (f <= rg->to)
-			break;
-
-	/* Round our left edge to the current segment if it encloses us. */
-	if (f > rg->from)
-		f = rg->from;
-
-	/* Check for and consume any regions we now overlap with. */
-	nrg = rg;
-	list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
-		if (&rg->link == head)
-			break;
-		if (rg->from > t)
-			break;
-
-		/* If this area reaches higher then extend our area to
-		 * include it completely.  If this is not the first area
-		 * which we intend to reuse, free it. */
-		if (rg->to > t)
-			t = rg->to;
-		if (rg != nrg) {
-			list_del(&rg->link);
-			kfree(rg);
-		}
-	}
-	nrg->from = f;
-	nrg->to = t;
-	return 0;
-}
-
-static long region_chg(struct list_head *head, long f, long t)
-{
-	struct file_region *rg, *nrg;
-	long chg = 0;
-
-	/* Locate the region we are before or in. */
-	list_for_each_entry(rg, head, link)
-		if (f <= rg->to)
-			break;
-
-	/* If we are below the current region then a new region is required.
-	 * Subtle, allocate a new region at the position but make it zero
-	 * size such that we can guarantee to record the reservation. */
-	if (&rg->link == head || t < rg->from) {
-		nrg = kmalloc(sizeof(*nrg), GFP_KERNEL);
-		if (!nrg)
-			return -ENOMEM;
-		nrg->from = f;
-		nrg->to   = f;
-		INIT_LIST_HEAD(&nrg->link);
-		list_add(&nrg->link, rg->link.prev);
-
-		return t - f;
-	}
-
-	/* Round our left edge to the current segment if it encloses us. */
-	if (f > rg->from)
-		f = rg->from;
-	chg = t - f;
-
-	/* Check for and consume any regions we now overlap with. */
-	list_for_each_entry(rg, rg->link.prev, link) {
-		if (&rg->link == head)
-			break;
-		if (rg->from > t)
-			return chg;
-
-		/* We overlap with this area, if it extends futher than
-		 * us then we must extend ourselves.  Account for its
-		 * existing reservation. */
-		if (rg->to > t) {
-			chg += rg->to - t;
-			t = rg->to;
-		}
-		chg -= rg->to - rg->from;
-	}
-	return chg;
-}
-
-static long region_truncate(struct list_head *head, long end)
+int hugetlb_reserve_pages(struct inode *inode,
+					long from, long to,
+					struct vm_area_struct *vma)
 {
-	struct file_region *rg, *trg;
-	long chg = 0;
+	long ret, chg;
+	struct hstate *h = hstate_inode(inode);
 
-	/* Locate the region we are either in or before. */
-	list_for_each_entry(rg, head, link)
-		if (end <= rg->to)
-			break;
-	if (&rg->link == head)
+	if (vma && vma->vm_flags & VM_NORESERVE)
 		return 0;
 
-	/* If we are in the middle of a region then adjust it. */
-	if (end > rg->from) {
-		chg = rg->to - end;
-		rg->to = end;
-		rg = list_entry(rg->link.next, typeof(*rg), link);
-	}
-
-	/* Drop any remaining regions. */
-	list_for_each_entry_safe(rg, trg, rg->link.prev, link) {
-		if (&rg->link == head)
-			break;
-		chg += rg->to - rg->from;
-		list_del(&rg->link);
-		kfree(rg);
-	}
-	return chg;
-}
-
-static int hugetlb_acct_memory(long delta)
-{
-	int ret = -ENOMEM;
-
-	spin_lock(&hugetlb_lock);
 	/*
-	 * When cpuset is configured, it breaks the strict hugetlb page
-	 * reservation as the accounting is done on a global variable. Such
-	 * reservation is completely rubbish in the presence of cpuset because
-	 * the reservation is not checked against page availability for the
-	 * current cpuset. Application can still potentially OOM'ed by kernel
-	 * with lack of free htlb page in cpuset that the task is in.
-	 * Attempt to enforce strict accounting with cpuset is almost
-	 * impossible (or too ugly) because cpuset is too fluid that
-	 * task or memory node can be dynamically moved between cpusets.
-	 *
-	 * The change of semantics for shared hugetlb mapping with cpuset is
-	 * undesirable. However, in order to preserve some of the semantics,
-	 * we fall back to check against current free page availability as
-	 * a best attempt and hopefully to minimize the impact of changing
-	 * semantics that cpuset has.
+	 * Shared mappings base their reservation on the number of pages that
+	 * are already allocated on behalf of the file. Private mappings need
+	 * to reserve the full area even if read-only as mprotect() may be
+	 * called to make the mapping read-write. Assume !vma is a shm mapping
 	 */
-	if (delta > 0) {
-		if (gather_surplus_pages(delta) < 0)
-			goto out;
-
-		if (delta > cpuset_mems_nr(free_huge_pages_node)) {
-			return_unused_surplus_pages(delta);
-			goto out;
-		}
-	}
-
-	ret = 0;
-	if (delta < 0)
-		return_unused_surplus_pages((unsigned long) -delta);
+	if (!vma || vma->vm_flags & VM_SHARED)
+		chg = region_chg(&inode->i_mapping->private_list, from, to);
+	else {
+		struct resv_map *resv_map = resv_map_alloc();
+		if (!resv_map)
+			return -ENOMEM;
 
-out:
-	spin_unlock(&hugetlb_lock);
-	return ret;
-}
+		chg = to - from;
 
-int hugetlb_reserve_pages(struct inode *inode, long from, long to)
-{
-	long ret, chg;
+		set_vma_resv_map(vma, resv_map);
+		set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
+	}
 
-	chg = region_chg(&inode->i_mapping->private_list, from, to);
 	if (chg < 0)
 		return chg;
 
 	if (hugetlb_get_quota(inode->i_mapping, chg))
 		return -ENOSPC;
-	ret = hugetlb_acct_memory(chg);
+	ret = hugetlb_acct_memory(h, chg);
 	if (ret < 0) {
 		hugetlb_put_quota(inode->i_mapping, chg);
 		return ret;
 	}
-	region_add(&inode->i_mapping->private_list, from, to);
+	if (!vma || vma->vm_flags & VM_SHARED)
+		region_add(&inode->i_mapping->private_list, from, to);
 	return 0;
 }
 
 void hugetlb_unreserve_pages(struct inode *inode, long offset, long freed)
 {
+	struct hstate *h = hstate_inode(inode);
 	long chg = region_truncate(&inode->i_mapping->private_list, offset);
 
 	spin_lock(&inode->i_lock);
-	inode->i_blocks -= BLOCKS_PER_HUGEPAGE * freed;
+	inode->i_blocks -= blocks_per_huge_page(h);
 	spin_unlock(&inode->i_lock);
 
 	hugetlb_put_quota(inode->i_mapping, (chg - freed));
-	hugetlb_acct_memory(-(chg - freed));
+	hugetlb_acct_memory(h, -(chg - freed));
 }