memcg: add interface to move charge at task migration
[linux-2.6.git] / mm / hugetlb.c
index 72acbb2..3a5aeb3 100644 (file)
@@ -7,33 +7,43 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/mm.h>
+#include <linux/seq_file.h>
 #include <linux/sysctl.h>
 #include <linux/highmem.h>
+#include <linux/mmu_notifier.h>
 #include <linux/nodemask.h>
 #include <linux/pagemap.h>
 #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>
+#include <asm/io.h>
 
 #include <linux/hugetlb.h>
+#include <linux/node.h>
 #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
@@ -43,6 +53,16 @@ static DEFINE_SPINLOCK(hugetlb_lock);
 /*
  * 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;
@@ -165,31 +185,80 @@ static long region_truncate(struct list_head *head, long end)
        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 base page units.
+ * the mapping, in pagecache page units; huge pages here.
  */
-static pgoff_t vma_page_offset(struct vm_area_struct *vma,
-                               unsigned long address)
+static pgoff_t vma_hugecache_offset(struct hstate *h,
+                       struct vm_area_struct *vma, unsigned long address)
 {
-       return ((address - vma->vm_start) >> PAGE_SHIFT) +
-                                       (vma->vm_pgoff >> PAGE_SHIFT);
+       return ((address - vma->vm_start) >> huge_page_shift(h)) +
+                       (vma->vm_pgoff >> huge_page_order(h));
 }
 
 /*
- * Convert the address within this vma to the page offset within
- * the mapping, in pagecache page units; huge pages here.
+ * Return the size of the pages allocated when backing a VMA. In the majority
+ * cases this will be same size as used by the page table entries.
  */
-static pgoff_t vma_pagecache_offset(struct vm_area_struct *vma,
-                                       unsigned long address)
+unsigned long vma_kernel_pagesize(struct vm_area_struct *vma)
 {
-       return ((address - vma->vm_start) >> HPAGE_SHIFT) +
-                       (vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT));
+       struct hstate *hstate;
+
+       if (!is_vm_hugetlb_page(vma))
+               return PAGE_SIZE;
+
+       hstate = hstate_vma(vma);
+
+       return 1UL << (hstate->order + PAGE_SHIFT);
 }
+EXPORT_SYMBOL_GPL(vma_kernel_pagesize);
 
-#define HPAGE_RESV_OWNER    (1UL << (BITS_PER_LONG - 1))
-#define HPAGE_RESV_UNMAPPED (1UL << (BITS_PER_LONG - 2))
+/*
+ * Return the page size being used by the MMU to back a VMA. In the majority
+ * of cases, the page size used by the kernel matches the MMU size. On
+ * architectures where it differs, an architecture-specific version of this
+ * function is required.
+ */
+#ifndef vma_mmu_pagesize
+unsigned long vma_mmu_pagesize(struct vm_area_struct *vma)
+{
+       return vma_kernel_pagesize(vma);
+}
+#endif
+
+/*
+ * 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()
@@ -199,6 +268,15 @@ static pgoff_t vma_pagecache_offset(struct vm_area_struct *vma,
  * 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)
 {
@@ -211,28 +289,54 @@ static void set_vma_private_data(struct vm_area_struct *vma,
        vma->vm_private_data = (void *)value;
 }
 
-static unsigned long vma_resv_huge_pages(struct vm_area_struct *vma)
+struct resv_map {
+       struct kref refs;
+       struct list_head regions;
+};
+
+static 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;
+}
+
+static 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 get_vma_private_data(vma) & ~HPAGE_RESV_MASK;
-       return 0;
+       if (!(vma->vm_flags & VM_MAYSHARE))
+               return (struct resv_map *)(get_vma_private_data(vma) &
+                                                       ~HPAGE_RESV_MASK);
+       return NULL;
 }
 
-static void set_vma_resv_huge_pages(struct vm_area_struct *vma,
-                                                       unsigned long reserve)
+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);
+       VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
 
-       set_vma_private_data(vma,
-               (get_vma_private_data(vma) & HPAGE_RESV_MASK) | reserve);
+       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);
+       VM_BUG_ON(vma->vm_flags & VM_MAYSHARE);
 
        set_vma_private_data(vma, get_vma_private_data(vma) | flags);
 }
@@ -245,27 +349,21 @@ static int is_vma_resv_set(struct vm_area_struct *vma, unsigned long flag)
 }
 
 /* Decrement the reserved pages in the hugepage pool by one */
-static void decrement_hugepage_resv_vma(struct vm_area_struct *vma)
+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) {
+       if (vma->vm_flags & VM_MAYSHARE) {
                /* Shared mappings always use reserves */
-               resv_huge_pages--;
-       } else {
+               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.
                 */
-               if (is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
-                       unsigned long flags, reserve;
-                       resv_huge_pages--;
-                       flags = (unsigned long)vma->vm_private_data &
-                                                       HPAGE_RESV_MASK;
-                       reserve = (unsigned long)vma->vm_private_data - 1;
-                       vma->vm_private_data = (void *)(reserve | flags);
-               }
+               h->resv_huge_pages--;
        }
 }
 
@@ -273,70 +371,94 @@ static void decrement_hugepage_resv_vma(struct vm_area_struct *vma)
 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))
+       if (!(vma->vm_flags & VM_MAYSHARE))
                vma->vm_private_data = (void *)0;
 }
 
 /* Returns true if the VMA has associated reserve pages */
-static int vma_has_private_reserves(struct vm_area_struct *vma)
+static int vma_has_reserves(struct vm_area_struct *vma)
 {
-       if (vma->vm_flags & VM_SHARED)
-               return 0;
-       if (!vma_resv_huge_pages(vma))
-               return 0;
-       return 1;
+       if (vma->vm_flags & VM_MAYSHARE)
+               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)
+static void clear_gigantic_page(struct page *page,
+                       unsigned long addr, unsigned long sz)
 {
        int i;
+       struct page *p = page;
 
        might_sleep();
-       for (i = 0; i < (HPAGE_SIZE/PAGE_SIZE); i++) {
+       for (i = 0; i < sz/PAGE_SIZE; i++, p = mem_map_next(p, page, i)) {
+               cond_resched();
+               clear_user_highpage(p, addr + i * PAGE_SIZE);
+       }
+}
+static void clear_huge_page(struct page *page,
+                       unsigned long addr, unsigned long sz)
+{
+       int i;
+
+       if (unlikely(sz/PAGE_SIZE > MAX_ORDER_NR_PAGES)) {
+               clear_gigantic_page(page, addr, sz);
+               return;
+       }
+
+       might_sleep();
+       for (i = 0; i < sz/PAGE_SIZE; i++) {
                cond_resched();
                clear_user_highpage(page + i, addr + i * PAGE_SIZE);
        }
 }
 
+static void copy_gigantic_page(struct page *dst, struct page *src,
+                          unsigned long addr, struct vm_area_struct *vma)
+{
+       int i;
+       struct hstate *h = hstate_vma(vma);
+       struct page *dst_base = dst;
+       struct page *src_base = src;
+       might_sleep();
+       for (i = 0; i < pages_per_huge_page(h); ) {
+               cond_resched();
+               copy_user_highpage(dst, src, addr + i*PAGE_SIZE, vma);
+
+               i++;
+               dst = mem_map_next(dst, dst_base, i);
+               src = mem_map_next(src, src_base, i);
+       }
+}
 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);
+
+       if (unlikely(pages_per_huge_page(h) > MAX_ORDER_NR_PAGES)) {
+               copy_gigantic_page(dst, src, addr, vma);
+               return;
+       }
 
        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)
-{
-       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,
-                                         struct page, lru);
-                       list_del(&page->lru);
-                       free_huge_pages--;
-                       free_huge_pages_node[nid]--;
-                       break;
-               }
-       }
-       return page;
-}
-
-static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma,
+static struct page *dequeue_huge_page_vma(struct hstate *h,
+                               struct vm_area_struct *vma,
                                unsigned long address, int avoid_reserve)
 {
        int nid;
@@ -353,27 +475,27 @@ static struct page *dequeue_huge_page_vma(struct vm_area_struct *vma,
         * have no page reserves. This check ensures that reservations are
         * not "stolen". The child may still get SIGKILLed
         */
-       if (!vma_has_private_reserves(vma) &&
-                       free_huge_pages - resv_huge_pages == 0)
+       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 && free_huge_pages - resv_huge_pages == 0)
+       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]--;
+                       h->free_huge_pages--;
+                       h->free_huge_pages_node[nid]--;
 
                        if (!avoid_reserve)
-                               decrement_hugepage_resv_vma(vma);
+                               decrement_hugepage_resv_vma(h, vma);
 
                        break;
                }
@@ -382,12 +504,15 @@ 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++) {
+
+       VM_BUG_ON(h->order >= MAX_ORDER);
+
+       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);
@@ -395,11 +520,27 @@ 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;
 
@@ -409,106 +550,139 @@ 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)
                hugetlb_put_quota(mapping, 1);
 }
 
-/*
- * Increment or decrement surplus_huge_pages.  Keep node-specific counters
- * 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 void prep_new_huge_page(struct hstate *h, struct page *page, int nid)
 {
-       static int prev_nid;
-       int nid = prev_nid;
-       int ret = 0;
+       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 */
+}
 
-       VM_BUG_ON(delta != -1 && delta != 1);
-       do {
-               nid = next_node(nid, node_online_map);
-               if (nid == MAX_NUMNODES)
-                       nid = first_node(node_online_map);
+static void prep_compound_gigantic_page(struct page *page, unsigned long order)
+{
+       int i;
+       int nr_pages = 1 << order;
+       struct page *p = page + 1;
+
+       /* we rely on prep_new_huge_page to set the destructor */
+       set_compound_order(page, order);
+       __SetPageHead(page);
+       for (i = 1; i < nr_pages; i++, p = mem_map_next(p, page, i)) {
+               __SetPageTail(p);
+               p->first_page = page;
+       }
+}
 
-               /* To shrink on this node, there must be a surplus page */
-               if (delta < 0 && !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])
-                       continue;
+int PageHuge(struct page *page)
+{
+       compound_page_dtor *dtor;
 
-               surplus_huge_pages += delta;
-               surplus_huge_pages_node[nid] += delta;
-               ret = 1;
-               break;
-       } while (nid != prev_nid);
+       if (!PageCompound(page))
+               return 0;
 
-       prev_nid = nid;
-       return ret;
+       page = compound_head(page);
+       dtor = get_compound_page_dtor(page);
+
+       return dtor == free_huge_page;
 }
 
-static struct page *alloc_fresh_huge_page_node(int nid)
+static struct page *alloc_fresh_huge_page_node(struct hstate *h, int nid)
 {
        struct page *page;
 
-       page = alloc_pages_node(nid,
+       if (h->order >= MAX_ORDER)
+               return NULL;
+
+       page = alloc_pages_exact_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);
+                       __free_pages(page, huge_page_order(h));
                        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)
+/*
+ * common helper functions for hstate_next_node_to_{alloc|free}.
+ * We may have allocated or freed a huge page based on a different
+ * nodes_allowed previously, so h->next_node_to_{alloc|free} might
+ * be outside of *nodes_allowed.  Ensure that we use an allowed
+ * node for alloc or free.
+ */
+static int next_node_allowed(int nid, nodemask_t *nodes_allowed)
+{
+       nid = next_node(nid, *nodes_allowed);
+       if (nid == MAX_NUMNODES)
+               nid = first_node(*nodes_allowed);
+       VM_BUG_ON(nid >= MAX_NUMNODES);
+
+       return nid;
+}
+
+static int get_valid_node_allowed(int nid, nodemask_t *nodes_allowed)
+{
+       if (!node_isset(nid, *nodes_allowed))
+               nid = next_node_allowed(nid, nodes_allowed);
+       return nid;
+}
+
+/*
+ * returns the previously saved node ["this node"] from which to
+ * allocate a persistent huge page for the pool and advance the
+ * next node from which to allocate, handling wrap at end of node
+ * mask.
+ */
+static int hstate_next_node_to_alloc(struct hstate *h,
+                                       nodemask_t *nodes_allowed)
+{
+       int nid;
+
+       VM_BUG_ON(!nodes_allowed);
+
+       nid = get_valid_node_allowed(h->next_nid_to_alloc, nodes_allowed);
+       h->next_nid_to_alloc = next_node_allowed(nid, nodes_allowed);
+
+       return nid;
+}
+
+static int alloc_fresh_huge_page(struct hstate *h, nodemask_t *nodes_allowed)
 {
        struct page *page;
        int start_nid;
        int next_nid;
        int ret = 0;
 
-       start_nid = hugetlb_next_nid;
+       start_nid = hstate_next_node_to_alloc(h, nodes_allowed);
+       next_nid = start_nid;
 
        do {
-               page = alloc_fresh_huge_page_node(hugetlb_next_nid);
-               if (page)
+               page = alloc_fresh_huge_page_node(h, 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);
+                       break;
+               }
+               next_nid = hstate_next_node_to_alloc(h, nodes_allowed);
+       } while (next_nid != start_nid);
 
        if (ret)
                count_vm_event(HTLB_BUDDY_PGALLOC);
@@ -518,12 +692,76 @@ static int alloc_fresh_huge_page(void)
        return ret;
 }
 
-static struct page *alloc_buddy_huge_page(struct vm_area_struct *vma,
-                                               unsigned long address)
+/*
+ * helper for free_pool_huge_page() - return the previously saved
+ * node ["this node"] from which to free a huge page.  Advance the
+ * next node id whether or not we find a free huge page to free so
+ * that the next attempt to free addresses the next node.
+ */
+static int hstate_next_node_to_free(struct hstate *h, nodemask_t *nodes_allowed)
+{
+       int nid;
+
+       VM_BUG_ON(!nodes_allowed);
+
+       nid = get_valid_node_allowed(h->next_nid_to_free, nodes_allowed);
+       h->next_nid_to_free = next_node_allowed(nid, nodes_allowed);
+
+       return nid;
+}
+
+/*
+ * Free huge page from pool from next node to free.
+ * Attempt to keep persistent huge pages more or less
+ * balanced over allowed nodes.
+ * Called with hugetlb_lock locked.
+ */
+static int free_pool_huge_page(struct hstate *h, nodemask_t *nodes_allowed,
+                                                        bool acct_surplus)
+{
+       int start_nid;
+       int next_nid;
+       int ret = 0;
+
+       start_nid = hstate_next_node_to_free(h, nodes_allowed);
+       next_nid = start_nid;
+
+       do {
+               /*
+                * If we're returning unused surplus pages, only examine
+                * nodes with surplus pages.
+                */
+               if ((!acct_surplus || h->surplus_huge_pages_node[next_nid]) &&
+                   !list_empty(&h->hugepage_freelists[next_nid])) {
+                       struct page *page =
+                               list_entry(h->hugepage_freelists[next_nid].next,
+                                         struct page, lru);
+                       list_del(&page->lru);
+                       h->free_huge_pages--;
+                       h->free_huge_pages_node[next_nid]--;
+                       if (acct_surplus) {
+                               h->surplus_huge_pages--;
+                               h->surplus_huge_pages_node[next_nid]--;
+                       }
+                       update_and_free_page(h, page);
+                       ret = 1;
+                       break;
+               }
+               next_nid = hstate_next_node_to_free(h, nodes_allowed);
+       } while (next_nid != start_nid);
+
+       return ret;
+}
+
+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
@@ -548,18 +786,23 @@ 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));
+
+       if (page && arch_prepare_hugepage(page)) {
+               __free_pages(page, huge_page_order(h));
+               return NULL;
+       }
 
        spin_lock(&hugetlb_lock);
        if (page) {
@@ -574,12 +817,12 @@ 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);
@@ -591,16 +834,16 @@ 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;
        }
 
@@ -611,7 +854,7 @@ 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
@@ -632,7 +875,8 @@ 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;
 
@@ -645,7 +889,7 @@ 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 */
@@ -653,7 +897,7 @@ 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 */
@@ -680,46 +924,33 @@ free:
  * When releasing a hugetlb pool reservation, any surplus pages that were
  * allocated to satisfy the reservation must be explicitly freed if they were
  * never used.
+ * Called with hugetlb_lock held.
  */
-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;
        unsigned long nr_pages;
 
-       /*
-        * We want to release as many surplus pages as possible, spread
-        * evenly across all nodes. Iterate across all nodes until we
-        * can no longer free unreserved surplus pages. This occurs when
-        * the nodes with surplus pages have no free pages.
-        */
-       unsigned long remaining_iterations = num_online_nodes();
-
        /* Uncommit the reservation */
-       resv_huge_pages -= unused_resv_pages;
+       h->resv_huge_pages -= unused_resv_pages;
 
-       nr_pages = min(unused_resv_pages, surplus_huge_pages);
+       /* Cannot return gigantic pages currently */
+       if (h->order >= MAX_ORDER)
+               return;
 
-       while (remaining_iterations-- && nr_pages) {
-               nid = next_node(nid, node_online_map);
-               if (nid == MAX_NUMNODES)
-                       nid = first_node(node_online_map);
+       nr_pages = min(unused_resv_pages, h->surplus_huge_pages);
 
-               if (!surplus_huge_pages_node[nid])
-                       continue;
-
-               if (!list_empty(&hugepage_freelists[nid])) {
-                       page = list_entry(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]--;
-                       nr_pages--;
-                       remaining_iterations = num_online_nodes();
-               }
+       /*
+        * We want to release as many surplus pages as possible, spread
+        * evenly across all nodes with memory. Iterate across these nodes
+        * until we can no longer free unreserved surplus pages. This occurs
+        * when the nodes with surplus pages have no free pages.
+        * free_pool_huge_page() will balance the the freed pages across the
+        * on-line nodes with memory and will handle the hstate accounting.
+        */
+       while (nr_pages--) {
+               if (!free_pool_huge_page(h, &node_states[N_HIGH_MEMORY], 1))
+                       break;
        }
 }
 
@@ -732,42 +963,58 @@ static void return_unused_surplus_pages(unsigned long unused_resv_pages)
  * an instantiated the change should be committed via vma_commit_reservation.
  * No action is required on failure.
  */
-static int vma_needs_reservation(struct vm_area_struct *vma, unsigned long addr)
+static long 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_pagecache_offset(vma, addr);
+       if (vma->vm_flags & VM_MAYSHARE) {
+               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;
-       }
+       } else if (!is_vma_resv_set(vma, HPAGE_RESV_OWNER)) {
+               return 1;
 
-       return 0;
+       } else  {
+               long 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 vm_area_struct *vma,
-                                                       unsigned long addr)
+static void vma_commit_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_pagecache_offset(vma, addr);
+       if (vma->vm_flags & VM_MAYSHARE) {
+               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(struct vm_area_struct *vma,
                                    unsigned long addr, int avoid_reserve)
 {
+       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;
+       long chg;
 
        /*
         * Processes that did not create the mapping will have no reserves and
@@ -776,7 +1023,7 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
         * MAP_NORESERVE mappings may also need pages and quota allocated
         * if no reserve mapping overlaps.
         */
-       chg = vma_needs_reservation(vma, addr);
+       chg = vma_needs_reservation(h, vma, addr);
        if (chg < 0)
                return ERR_PTR(chg);
        if (chg)
@@ -784,11 +1031,11 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
                        return ERR_PTR(-ENOSPC);
 
        spin_lock(&hugetlb_lock);
-       page = dequeue_huge_page_vma(vma, addr, avoid_reserve);
+       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(inode->i_mapping, chg);
                        return ERR_PTR(-VM_FAULT_OOM);
@@ -798,83 +1045,210 @@ static struct page *alloc_huge_page(struct vm_area_struct *vma,
        set_page_refcounted(page);
        set_page_private(page, (unsigned long) mapping);
 
-       vma_commit_reservation(vma, addr);
+       vma_commit_reservation(h, vma, addr);
 
        return page;
 }
 
-static int __init hugetlb_init(void)
+int __weak alloc_bootmem_huge_page(struct hstate *h)
 {
-       unsigned long i;
-
-       if (HPAGE_SHIFT == 0)
-               return 0;
+       struct huge_bootmem_page *m;
+       int nr_nodes = nodes_weight(node_states[N_HIGH_MEMORY]);
 
-       for (i = 0; i < MAX_NUMNODES; ++i)
-               INIT_LIST_HEAD(&hugepage_freelists[i]);
+       while (nr_nodes) {
+               void *addr;
 
-       hugetlb_next_nid = first_node(node_online_map);
+               addr = __alloc_bootmem_node_nopanic(
+                               NODE_DATA(hstate_next_node_to_alloc(h,
+                                               &node_states[N_HIGH_MEMORY])),
+                               huge_page_size(h), huge_page_size(h), 0);
 
-       for (i = 0; i < max_huge_pages; ++i) {
-               if (!alloc_fresh_huge_page())
-                       break;
+               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;
+                       goto found;
+               }
+               nr_nodes--;
        }
-       max_huge_pages = free_huge_pages = nr_huge_pages = i;
-       printk("Total HugeTLB memory allocated, %ld\n", free_huge_pages);
        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;
 }
-module_init(hugetlb_init);
 
-static int __init hugetlb_setup(char *s)
+static void prep_compound_huge_page(struct page *page, int order)
 {
-       if (sscanf(s, "%lu", &max_huge_pages) <= 0)
-               max_huge_pages = 0;
-       return 1;
+       if (unlikely(order > (MAX_ORDER - 1)))
+               prep_compound_gigantic_page(page, order);
+       else
+               prep_compound_page(page, order);
 }
-__setup("hugepages=", hugetlb_setup);
 
-static unsigned int cpuset_mems_nr(unsigned int *array)
+/* Put bootmem huge pages into the standard lists after mem_map is up */
+static void __init gather_bootmem_prealloc(void)
 {
-       int node;
-       unsigned int nr = 0;
+       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_huge_page(page, h->order);
+               prep_new_huge_page(h, page, page_to_nid(page));
+       }
+}
 
-       for_each_node_mask(node, cpuset_current_mems_allowed)
-               nr += array[node];
+static void __init hugetlb_hstate_alloc_pages(struct hstate *h)
+{
+       unsigned long i;
 
-       return nr;
+       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,
+                                        &node_states[N_HIGH_MEMORY]))
+                       break;
+       }
+       h->max_huge_pages = i;
+}
+
+static void __init hugetlb_init_hstates(void)
+{
+       struct hstate *h;
+
+       for_each_hstate(h) {
+               /* oversize hugepages were init'ed in early boot */
+               if (h->order < MAX_ORDER)
+                       hugetlb_hstate_alloc_pages(h);
+       }
+}
+
+static char * __init memfmt(char *buf, unsigned long n)
+{
+       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);
+       }
 }
 
-#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,
+                                               nodemask_t *nodes_allowed)
 {
        int i;
 
-       for (i = 0; i < MAX_NUMNODES; ++i) {
+       if (h->order >= MAX_ORDER)
+               return;
+
+       for_each_node_mask(i, *nodes_allowed) {
                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,
+                                               nodemask_t *nodes_allowed)
 {
 }
 #endif
 
-#define persistent_huge_pages (nr_huge_pages - surplus_huge_pages)
-static unsigned long set_max_huge_pages(unsigned long count)
+/*
+ * Increment or decrement surplus_huge_pages.  Keep node-specific counters
+ * balanced by operating on them in a round-robin fashion.
+ * Returns 1 if an adjustment was made.
+ */
+static int adjust_pool_surplus(struct hstate *h, nodemask_t *nodes_allowed,
+                               int delta)
+{
+       int start_nid, next_nid;
+       int ret = 0;
+
+       VM_BUG_ON(delta != -1 && delta != 1);
+
+       if (delta < 0)
+               start_nid = hstate_next_node_to_alloc(h, nodes_allowed);
+       else
+               start_nid = hstate_next_node_to_free(h, nodes_allowed);
+       next_nid = start_nid;
+
+       do {
+               int nid = next_nid;
+               if (delta < 0)  {
+                       /*
+                        * To shrink on this node, there must be a surplus page
+                        */
+                       if (!h->surplus_huge_pages_node[nid]) {
+                               next_nid = hstate_next_node_to_alloc(h,
+                                                               nodes_allowed);
+                               continue;
+                       }
+               }
+               if (delta > 0) {
+                       /*
+                        * Surplus cannot exceed the total number of pages
+                        */
+                       if (h->surplus_huge_pages_node[nid] >=
+                                               h->nr_huge_pages_node[nid]) {
+                               next_nid = hstate_next_node_to_free(h,
+                                                               nodes_allowed);
+                               continue;
+                       }
+               }
+
+               h->surplus_huge_pages += delta;
+               h->surplus_huge_pages_node[nid] += delta;
+               ret = 1;
+               break;
+       } while (next_nid != start_nid);
+
+       return ret;
+}
+
+#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,
+                                               nodemask_t *nodes_allowed)
 {
        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
@@ -887,23 +1261,26 @@ 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, nodes_allowed, -1))
                        break;
        }
 
-       while (count > persistent_huge_pages) {
+       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, nodes_allowed);
                spin_lock(&hugetlb_lock);
                if (!ret)
                        goto out;
 
+               /* Bail for signals. Probably ctrl-c from user */
+               if (signal_pending(current))
+                       goto out;
        }
 
        /*
@@ -921,39 +1298,605 @@ 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();
-               if (!page)
+       try_to_free_low(h, min_count, nodes_allowed);
+       while (min_count < persistent_huge_pages(h)) {
+               if (!free_pool_huge_page(h, nodes_allowed, 0))
                        break;
-               update_and_free_page(page);
        }
-       while (count < persistent_huge_pages) {
-               if (!adjust_pool_surplus(1))
+       while (count < persistent_huge_pages(h)) {
+               if (!adjust_pool_surplus(h, nodes_allowed, 1))
                        break;
        }
 out:
-       ret = persistent_huge_pages;
+       ret = persistent_huge_pages(h);
        spin_unlock(&hugetlb_lock);
        return ret;
 }
 
-int hugetlb_sysctl_handler(struct ctl_table *table, int write,
-                          struct file *file, void __user *buffer,
-                          size_t *length, loff_t *ppos)
+#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_node_hstate(struct kobject *kobj, int *nidp);
+
+static struct hstate *kobj_to_hstate(struct kobject *kobj, int *nidp)
+{
+       int i;
+
+       for (i = 0; i < HUGE_MAX_HSTATE; i++)
+               if (hstate_kobjs[i] == kobj) {
+                       if (nidp)
+                               *nidp = NUMA_NO_NODE;
+                       return &hstates[i];
+               }
+
+       return kobj_to_node_hstate(kobj, nidp);
+}
+
+static ssize_t nr_hugepages_show_common(struct kobject *kobj,
+                                       struct kobj_attribute *attr, char *buf)
+{
+       struct hstate *h;
+       unsigned long nr_huge_pages;
+       int nid;
+
+       h = kobj_to_hstate(kobj, &nid);
+       if (nid == NUMA_NO_NODE)
+               nr_huge_pages = h->nr_huge_pages;
+       else
+               nr_huge_pages = h->nr_huge_pages_node[nid];
+
+       return sprintf(buf, "%lu\n", nr_huge_pages);
+}
+static ssize_t nr_hugepages_store_common(bool obey_mempolicy,
+                       struct kobject *kobj, struct kobj_attribute *attr,
+                       const char *buf, size_t len)
 {
-       proc_doulongvec_minmax(table, write, file, buffer, length, ppos);
-       max_huge_pages = set_max_huge_pages(max_huge_pages);
+       int err;
+       int nid;
+       unsigned long count;
+       struct hstate *h;
+       NODEMASK_ALLOC(nodemask_t, nodes_allowed, GFP_KERNEL | __GFP_NORETRY);
+
+       err = strict_strtoul(buf, 10, &count);
+       if (err)
+               return 0;
+
+       h = kobj_to_hstate(kobj, &nid);
+       if (nid == NUMA_NO_NODE) {
+               /*
+                * global hstate attribute
+                */
+               if (!(obey_mempolicy &&
+                               init_nodemask_of_mempolicy(nodes_allowed))) {
+                       NODEMASK_FREE(nodes_allowed);
+                       nodes_allowed = &node_states[N_HIGH_MEMORY];
+               }
+       } else if (nodes_allowed) {
+               /*
+                * per node hstate attribute: adjust count to global,
+                * but restrict alloc/free to the specified node.
+                */
+               count += h->nr_huge_pages - h->nr_huge_pages_node[nid];
+               init_nodemask_of_node(nodes_allowed, nid);
+       } else
+               nodes_allowed = &node_states[N_HIGH_MEMORY];
+
+       h->max_huge_pages = set_max_huge_pages(h, count, nodes_allowed);
+
+       if (nodes_allowed != &node_states[N_HIGH_MEMORY])
+               NODEMASK_FREE(nodes_allowed);
+
+       return len;
+}
+
+static ssize_t nr_hugepages_show(struct kobject *kobj,
+                                      struct kobj_attribute *attr, char *buf)
+{
+       return nr_hugepages_show_common(kobj, attr, buf);
+}
+
+static ssize_t nr_hugepages_store(struct kobject *kobj,
+              struct kobj_attribute *attr, const char *buf, size_t len)
+{
+       return nr_hugepages_store_common(false, kobj, attr, buf, len);
+}
+HSTATE_ATTR(nr_hugepages);
+
+#ifdef CONFIG_NUMA
+
+/*
+ * hstate attribute for optionally mempolicy-based constraint on persistent
+ * huge page alloc/free.
+ */
+static ssize_t nr_hugepages_mempolicy_show(struct kobject *kobj,
+                                      struct kobj_attribute *attr, char *buf)
+{
+       return nr_hugepages_show_common(kobj, attr, buf);
+}
+
+static ssize_t nr_hugepages_mempolicy_store(struct kobject *kobj,
+              struct kobj_attribute *attr, const char *buf, size_t len)
+{
+       return nr_hugepages_store_common(true, kobj, attr, buf, len);
+}
+HSTATE_ATTR(nr_hugepages_mempolicy);
+#endif
+
+
+static ssize_t nr_overcommit_hugepages_show(struct kobject *kobj,
+                                       struct kobj_attribute *attr, char *buf)
+{
+       struct hstate *h = kobj_to_hstate(kobj, NULL);
+       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, NULL);
+
+       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;
+       unsigned long free_huge_pages;
+       int nid;
+
+       h = kobj_to_hstate(kobj, &nid);
+       if (nid == NUMA_NO_NODE)
+               free_huge_pages = h->free_huge_pages;
+       else
+               free_huge_pages = h->free_huge_pages_node[nid];
+
+       return sprintf(buf, "%lu\n", 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, NULL);
+       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;
+       unsigned long surplus_huge_pages;
+       int nid;
+
+       h = kobj_to_hstate(kobj, &nid);
+       if (nid == NUMA_NO_NODE)
+               surplus_huge_pages = h->surplus_huge_pages;
+       else
+               surplus_huge_pages = h->surplus_huge_pages_node[nid];
+
+       return sprintf(buf, "%lu\n", 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,
+#ifdef CONFIG_NUMA
+       &nr_hugepages_mempolicy_attr.attr,
+#endif
+       NULL,
+};
+
+static struct attribute_group hstate_attr_group = {
+       .attrs = hstate_attrs,
+};
+
+static int hugetlb_sysfs_add_hstate(struct hstate *h, struct kobject *parent,
+                                   struct kobject **hstate_kobjs,
+                                   struct attribute_group *hstate_attr_group)
+{
+       int retval;
+       int hi = h - hstates;
+
+       hstate_kobjs[hi] = kobject_create_and_add(h->name, parent);
+       if (!hstate_kobjs[hi])
+               return -ENOMEM;
+
+       retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group);
+       if (retval)
+               kobject_put(hstate_kobjs[hi]);
+
+       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, hugepages_kobj,
+                                        hstate_kobjs, &hstate_attr_group);
+               if (err)
+                       printk(KERN_ERR "Hugetlb: Unable to add hstate %s",
+                                                               h->name);
+       }
+}
+
+#ifdef CONFIG_NUMA
+
+/*
+ * node_hstate/s - associate per node hstate attributes, via their kobjects,
+ * with node sysdevs in node_devices[] using a parallel array.  The array
+ * index of a node sysdev or _hstate == node id.
+ * This is here to avoid any static dependency of the node sysdev driver, in
+ * the base kernel, on the hugetlb module.
+ */
+struct node_hstate {
+       struct kobject          *hugepages_kobj;
+       struct kobject          *hstate_kobjs[HUGE_MAX_HSTATE];
+};
+struct node_hstate node_hstates[MAX_NUMNODES];
+
+/*
+ * A subset of global hstate attributes for node sysdevs
+ */
+static struct attribute *per_node_hstate_attrs[] = {
+       &nr_hugepages_attr.attr,
+       &free_hugepages_attr.attr,
+       &surplus_hugepages_attr.attr,
+       NULL,
+};
+
+static struct attribute_group per_node_hstate_attr_group = {
+       .attrs = per_node_hstate_attrs,
+};
+
+/*
+ * kobj_to_node_hstate - lookup global hstate for node sysdev hstate attr kobj.
+ * Returns node id via non-NULL nidp.
+ */
+static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
+{
+       int nid;
+
+       for (nid = 0; nid < nr_node_ids; nid++) {
+               struct node_hstate *nhs = &node_hstates[nid];
+               int i;
+               for (i = 0; i < HUGE_MAX_HSTATE; i++)
+                       if (nhs->hstate_kobjs[i] == kobj) {
+                               if (nidp)
+                                       *nidp = nid;
+                               return &hstates[i];
+                       }
+       }
+
+       BUG();
+       return NULL;
+}
+
+/*
+ * Unregister hstate attributes from a single node sysdev.
+ * No-op if no hstate attributes attached.
+ */
+void hugetlb_unregister_node(struct node *node)
+{
+       struct hstate *h;
+       struct node_hstate *nhs = &node_hstates[node->sysdev.id];
+
+       if (!nhs->hugepages_kobj)
+               return;         /* no hstate attributes */
+
+       for_each_hstate(h)
+               if (nhs->hstate_kobjs[h - hstates]) {
+                       kobject_put(nhs->hstate_kobjs[h - hstates]);
+                       nhs->hstate_kobjs[h - hstates] = NULL;
+               }
+
+       kobject_put(nhs->hugepages_kobj);
+       nhs->hugepages_kobj = NULL;
+}
+
+/*
+ * hugetlb module exit:  unregister hstate attributes from node sysdevs
+ * that have them.
+ */
+static void hugetlb_unregister_all_nodes(void)
+{
+       int nid;
+
+       /*
+        * disable node sysdev registrations.
+        */
+       register_hugetlbfs_with_node(NULL, NULL);
+
+       /*
+        * remove hstate attributes from any nodes that have them.
+        */
+       for (nid = 0; nid < nr_node_ids; nid++)
+               hugetlb_unregister_node(&node_devices[nid]);
+}
+
+/*
+ * Register hstate attributes for a single node sysdev.
+ * No-op if attributes already registered.
+ */
+void hugetlb_register_node(struct node *node)
+{
+       struct hstate *h;
+       struct node_hstate *nhs = &node_hstates[node->sysdev.id];
+       int err;
+
+       if (nhs->hugepages_kobj)
+               return;         /* already allocated */
+
+       nhs->hugepages_kobj = kobject_create_and_add("hugepages",
+                                                       &node->sysdev.kobj);
+       if (!nhs->hugepages_kobj)
+               return;
+
+       for_each_hstate(h) {
+               err = hugetlb_sysfs_add_hstate(h, nhs->hugepages_kobj,
+                                               nhs->hstate_kobjs,
+                                               &per_node_hstate_attr_group);
+               if (err) {
+                       printk(KERN_ERR "Hugetlb: Unable to add hstate %s"
+                                       " for node %d\n",
+                                               h->name, node->sysdev.id);
+                       hugetlb_unregister_node(node);
+                       break;
+               }
+       }
+}
+
+/*
+ * hugetlb init time:  register hstate attributes for all registered node
+ * sysdevs of nodes that have memory.  All on-line nodes should have
+ * registered their associated sysdev by this time.
+ */
+static void hugetlb_register_all_nodes(void)
+{
+       int nid;
+
+       for_each_node_state(nid, N_HIGH_MEMORY) {
+               struct node *node = &node_devices[nid];
+               if (node->sysdev.id == nid)
+                       hugetlb_register_node(node);
+       }
+
+       /*
+        * Let the node sysdev driver know we're here so it can
+        * [un]register hstate attributes on node hotplug.
+        */
+       register_hugetlbfs_with_node(hugetlb_register_node,
+                                    hugetlb_unregister_node);
+}
+#else  /* !CONFIG_NUMA */
+
+static struct hstate *kobj_to_node_hstate(struct kobject *kobj, int *nidp)
+{
+       BUG();
+       if (nidp)
+               *nidp = -1;
+       return NULL;
+}
+
+static void hugetlb_unregister_all_nodes(void) { }
+
+static void hugetlb_register_all_nodes(void) { }
+
+#endif
+
+static void __exit hugetlb_exit(void)
+{
+       struct hstate *h;
+
+       hugetlb_unregister_all_nodes();
+
+       for_each_hstate(h) {
+               kobject_put(hstate_kobjs[h - hstates]);
+       }
+
+       kobject_put(hugepages_kobj);
+}
+module_exit(hugetlb_exit);
+
+static int __init hugetlb_init(void)
+{
+       /* Some platform decide whether they support huge pages at boot
+        * time. On these, such as powerpc, HPAGE_SHIFT is set to 0 when
+        * there is no such support
+        */
+       if (HPAGE_SHIFT == 0)
+               return 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();
+
+       hugetlb_register_all_nodes();
+
        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->next_nid_to_alloc = first_node(node_states[N_HIGH_MEMORY]);
+       h->next_nid_to_free = first_node(node_states[N_HIGH_MEMORY]);
+       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);
+
+static unsigned int cpuset_mems_nr(unsigned int *array)
+{
+       int node;
+       unsigned int nr = 0;
+
+       for_each_node_mask(node, cpuset_current_mems_allowed)
+               nr += array[node];
+
+       return nr;
+}
+
+#ifdef CONFIG_SYSCTL
+static int hugetlb_sysctl_handler_common(bool obey_mempolicy,
+                        struct ctl_table *table, int write,
+                        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, buffer, length, ppos);
+
+       if (write) {
+               NODEMASK_ALLOC(nodemask_t, nodes_allowed,
+                                               GFP_KERNEL | __GFP_NORETRY);
+               if (!(obey_mempolicy &&
+                              init_nodemask_of_mempolicy(nodes_allowed))) {
+                       NODEMASK_FREE(nodes_allowed);
+                       nodes_allowed = &node_states[N_HIGH_MEMORY];
+               }
+               h->max_huge_pages = set_max_huge_pages(h, tmp, nodes_allowed);
+
+               if (nodes_allowed != &node_states[N_HIGH_MEMORY])
+                       NODEMASK_FREE(nodes_allowed);
+       }
+
+       return 0;
+}
+
+int hugetlb_sysctl_handler(struct ctl_table *table, int write,
+                         void __user *buffer, size_t *length, loff_t *ppos)
+{
+
+       return hugetlb_sysctl_handler_common(false, table, write,
+                                                       buffer, length, ppos);
+}
+
+#ifdef CONFIG_NUMA
+int hugetlb_mempolicy_sysctl_handler(struct ctl_table *table, int write,
+                         void __user *buffer, size_t *length, loff_t *ppos)
+{
+       return hugetlb_sysctl_handler_common(true, table, write,
+                                                       buffer, length, ppos);
+}
+#endif /* CONFIG_NUMA */
 
 int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
-                       struct file *file, void __user *buffer,
+                       void __user *buffer,
                        size_t *length, loff_t *ppos)
 {
-       proc_dointvec(table, write, file, buffer, length, ppos);
+       proc_dointvec(table, write, buffer, length, ppos);
        if (hugepages_treat_as_movable)
                htlb_alloc_mask = GFP_HIGHUSER_MOVABLE;
        else
@@ -962,51 +1905,66 @@ int hugetlb_treat_movable_handler(struct ctl_table *table, int write,
 }
 
 int hugetlb_overcommit_handler(struct ctl_table *table, int write,
-                       struct file *file, void __user *buffer,
+                       void __user *buffer,
                        size_t *length, loff_t *ppos)
 {
-       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);
+       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, buffer, length, ppos);
+
+       if (write) {
+               spin_lock(&hugetlb_lock);
+               h->nr_overcommit_huge_pages = tmp;
+               spin_unlock(&hugetlb_lock);
+       }
+
        return 0;
 }
 
 #endif /* CONFIG_SYSCTL */
 
-int hugetlb_report_meminfo(char *buf)
+void hugetlb_report_meminfo(struct seq_file *m)
 {
-       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);
+       struct hstate *h = &default_hstate;
+       seq_printf(m,
+                       "HugePages_Total:   %5lu\n"
+                       "HugePages_Free:    %5lu\n"
+                       "HugePages_Rsvd:    %5lu\n"
+                       "HugePages_Surp:    %5lu\n"
+                       "Hugepagesize:   %8lu kB\n",
+                       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(long delta)
+static int hugetlb_acct_memory(struct hstate *h, long delta)
 {
        int ret = -ENOMEM;
 
@@ -1029,29 +1987,62 @@ static int hugetlb_acct_memory(long delta)
         * semantics that cpuset has.
         */
        if (delta > 0) {
-               if (gather_surplus_pages(delta) < 0)
+               if (gather_surplus_pages(h, delta) < 0)
                        goto out;
 
-               if (delta > cpuset_mems_nr(free_huge_pages_node)) {
-                       return_unused_surplus_pages(delta);
+               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((unsigned long) -delta);
+               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)
 {
-       unsigned long reserve = vma_resv_huge_pages(vma);
-       if (reserve)
-               hugetlb_acct_memory(-reserve);
+       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);
+               }
+       }
 }
 
 /*
@@ -1066,8 +2057,9 @@ static int hugetlb_vm_op_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
        return 0;
 }
 
-struct vm_operations_struct hugetlb_vm_ops = {
+const struct vm_operations_struct hugetlb_vm_ops = {
        .fault = hugetlb_vm_op_fault,
+       .open = hugetlb_vm_op_open,
        .close = hugetlb_vm_op_close,
 };
 
@@ -1095,7 +2087,7 @@ static void set_huge_ptep_writable(struct vm_area_struct *vma,
 
        entry = pte_mkwrite(pte_mkdirty(huge_ptep_get(ptep)));
        if (huge_ptep_set_access_flags(vma, address, ptep, entry, 1)) {
-               update_mmu_cache(vma, address, entry);
+               update_mmu_cache(vma, address, ptep);
        }
 }
 
@@ -1107,14 +2099,16 @@ 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;
 
@@ -1150,6 +2144,9 @@ 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
@@ -1158,11 +2155,12 @@ 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));
 
+       mmu_notifier_invalidate_range_start(mm, start, end);
        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;
@@ -1202,6 +2200,7 @@ void __unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
        }
        spin_unlock(&mm->page_table_lock);
        flush_tlb_range(vma, start, end);
+       mmu_notifier_invalidate_range_end(mm, start, end);
        list_for_each_entry_safe(page, tmp, &page_list, lru) {
                list_del(&page->lru);
                put_page(page);
@@ -1211,19 +2210,9 @@ 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, struct page *ref_page)
 {
-       /*
-        * 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.
-        */
-       if (vma->vm_file) {
-               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);
-       }
+       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);
 }
 
 /*
@@ -1232,11 +2221,10 @@ void unmap_hugepage_range(struct vm_area_struct *vma, unsigned long start,
  * 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)
+static int unmap_ref_private(struct mm_struct *mm, struct vm_area_struct *vma,
+                               struct page *page, unsigned long address)
 {
+       struct hstate *h = hstate_vma(vma);
        struct vm_area_struct *iter_vma;
        struct address_space *mapping;
        struct prio_tree_iter iter;
@@ -1246,11 +2234,17 @@ int unmap_ref_private(struct mm_struct *mm,
         * vm_pgoff is in PAGE_SIZE units, hence the different calculation
         * from page cache lookup which is in HPAGE_SIZE units.
         */
-       address = address & huge_page_mask(hstate_vma(vma));
+       address = address & huge_page_mask(h);
        pgoff = ((address - vma->vm_start) >> PAGE_SHIFT)
                + (vma->vm_pgoff >> PAGE_SHIFT);
        mapping = (struct address_space *)page_private(page);
 
+       /*
+        * Take the mapping lock for the duration of the table walk. As
+        * this mapping should be shared between all the VMAs,
+        * __unmap_hugepage_range() is called as the lock is already held
+        */
+       spin_lock(&mapping->i_mmap_lock);
        vma_prio_tree_foreach(iter_vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
                /* Do not unmap the current VMA */
                if (iter_vma == vma)
@@ -1264,10 +2258,11 @@ int unmap_ref_private(struct mm_struct *mm,
                 * 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,
+                       __unmap_hugepage_range(iter_vma,
+                               address, address + huge_page_size(h),
                                page);
        }
+       spin_unlock(&mapping->i_mmap_lock);
 
        return 1;
 }
@@ -1276,6 +2271,7 @@ static int hugetlb_cow(struct mm_struct *mm, struct vm_area_struct *vma,
                        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;
@@ -1300,12 +2296,15 @@ retry_avoidcopy:
         * at the time of fork() could consume its reserves on COW instead
         * of the full address range.
         */
-       if (!(vma->vm_flags & VM_SHARED) &&
+       if (!(vma->vm_flags & VM_MAYSHARE) &&
                        is_vma_resv_set(vma, HPAGE_RESV_OWNER) &&
                        old_page != pagecache_page)
                outside_reserve = 1;
 
        page_cache_get(old_page);
+
+       /* Drop page_table_lock as buddy allocator may be called */
+       spin_unlock(&mm->page_table_lock);
        new_page = alloc_huge_page(vma, address, outside_reserve);
 
        if (IS_ERR(new_page)) {
@@ -1323,20 +2322,26 @@ retry_avoidcopy:
                        if (unmap_ref_private(mm, vma, old_page, address)) {
                                BUG_ON(page_count(old_page) != 1);
                                BUG_ON(huge_pte_none(pte));
+                               spin_lock(&mm->page_table_lock);
                                goto retry_avoidcopy;
                        }
                        WARN_ON_ONCE(1);
                }
 
+               /* Caller expects lock to be held */
+               spin_lock(&mm->page_table_lock);
                return -PTR_ERR(new_page);
        }
 
-       spin_unlock(&mm->page_table_lock);
        copy_huge_page(new_page, old_page, address, vma);
        __SetPageUptodate(new_page);
-       spin_lock(&mm->page_table_lock);
 
-       ptep = huge_pte_offset(mm, address & HPAGE_MASK);
+       /*
+        * Retake the page_table_lock to check for racing updates
+        * before the page tables are altered
+        */
+       spin_lock(&mm->page_table_lock);
+       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);
@@ -1351,21 +2356,42 @@ retry_avoidcopy:
 }
 
 /* Return the pagecache page at a given address within a VMA */
-static struct page *hugetlbfs_pagecache_page(struct vm_area_struct *vma,
-                       unsigned long address)
+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_pagecache_offset(vma, address);
+       idx = vma_hugecache_offset(h, vma, address);
 
        return find_lock_page(mapping, idx);
 }
 
+/*
+ * Return whether there is a pagecache page to back given address within VMA.
+ * Caller follow_hugetlb_page() holds page_table_lock so we cannot lock_page.
+ */
+static bool hugetlbfs_pagecache_present(struct hstate *h,
+                       struct vm_area_struct *vma, unsigned long address)
+{
+       struct address_space *mapping;
+       pgoff_t idx;
+       struct page *page;
+
+       mapping = vma->vm_file->f_mapping;
+       idx = vma_hugecache_offset(h, vma, address);
+
+       page = find_get_page(mapping, idx);
+       if (page)
+               put_page(page);
+       return page != NULL;
+}
+
 static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
-                       unsigned long address, pte_t *ptep, int write_access)
+                       unsigned long address, pte_t *ptep, unsigned int flags)
 {
+       struct hstate *h = hstate_vma(vma);
        int ret = VM_FAULT_SIGBUS;
        pgoff_t idx;
        unsigned long size;
@@ -1386,7 +2412,7 @@ static int hugetlb_no_page(struct mm_struct *mm, struct vm_area_struct *vma,
        }
 
        mapping = vma->vm_file->f_mapping;
-       idx = vma_pagecache_offset(vma, address);
+       idx = vma_hugecache_offset(h, vma, address);
 
        /*
         * Use page lock to guard against racing truncation
@@ -1395,7 +2421,7 @@ 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, 0);
@@ -1403,10 +2429,10 @@ retry:
                        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) {
+               if (vma->vm_flags & VM_MAYSHARE) {
                        int err;
                        struct inode *inode = mapping->host;
 
@@ -1419,14 +2445,26 @@ 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);
        }
 
+       /*
+        * If we are going to COW a private mapping later, we examine the
+        * pending reservations for this page now. This will ensure that
+        * any allocations necessary to record that reservation occur outside
+        * the spinlock.
+        */
+       if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED))
+               if (vma_needs_reservation(h, vma, address) < 0) {
+                       ret = VM_FAULT_OOM;
+                       goto backout_unlocked;
+               }
+
        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;
 
@@ -1438,7 +2476,7 @@ retry:
                                && (vma->vm_flags & VM_SHARED)));
        set_huge_pte_at(mm, address, ptep, new_pte);
 
-       if (write_access && !(vma->vm_flags & VM_SHARED)) {
+       if ((flags & FAULT_FLAG_WRITE) && !(vma->vm_flags & VM_SHARED)) {
                /* Optimization, do the COW without a second fault */
                ret = hugetlb_cow(mm, vma, address, ptep, new_pte, page);
        }
@@ -1450,20 +2488,23 @@ out:
 
 backout:
        spin_unlock(&mm->page_table_lock);
+backout_unlocked:
        unlock_page(page);
        put_page(page);
        goto out;
 }
 
 int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
-                       unsigned long address, int write_access)
+                       unsigned long address, unsigned int flags)
 {
        pte_t *ptep;
        pte_t entry;
        int ret;
+       struct page *pagecache_page = NULL;
        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;
 
@@ -1475,74 +2516,131 @@ int hugetlb_fault(struct mm_struct *mm, struct vm_area_struct *vma,
        mutex_lock(&hugetlb_instantiation_mutex);
        entry = huge_ptep_get(ptep);
        if (huge_pte_none(entry)) {
-               ret = hugetlb_no_page(mm, vma, address, ptep, write_access);
-               mutex_unlock(&hugetlb_instantiation_mutex);
-               return ret;
+               ret = hugetlb_no_page(mm, vma, address, ptep, flags);
+               goto out_mutex;
        }
 
        ret = 0;
 
+       /*
+        * If we are going to COW the mapping later, we examine the pending
+        * reservations for this page now. This will ensure that any
+        * allocations necessary to record that reservation occur outside the
+        * spinlock. For private mappings, we also lookup the pagecache
+        * page now as it is used to determine if a reservation has been
+        * consumed.
+        */
+       if ((flags & FAULT_FLAG_WRITE) && !pte_write(entry)) {
+               if (vma_needs_reservation(h, vma, address) < 0) {
+                       ret = VM_FAULT_OOM;
+                       goto out_mutex;
+               }
+
+               if (!(vma->vm_flags & VM_MAYSHARE))
+                       pagecache_page = hugetlbfs_pagecache_page(h,
+                                                               vma, address);
+       }
+
        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)) {
-                       struct page *page;
-                       page = hugetlbfs_pagecache_page(vma, address);
-                       ret = hugetlb_cow(mm, vma, address, ptep, entry, page);
-                       if (page) {
-                               unlock_page(page);
-                               put_page(page);
-                       }
+       if (unlikely(!pte_same(entry, huge_ptep_get(ptep))))
+               goto out_page_table_lock;
+
+
+       if (flags & FAULT_FLAG_WRITE) {
+               if (!pte_write(entry)) {
+                       ret = hugetlb_cow(mm, vma, address, ptep, entry,
+                                                       pagecache_page);
+                       goto out_page_table_lock;
                }
+               entry = pte_mkdirty(entry);
+       }
+       entry = pte_mkyoung(entry);
+       if (huge_ptep_set_access_flags(vma, address, ptep, entry,
+                                               flags & FAULT_FLAG_WRITE))
+               update_mmu_cache(vma, address, ptep);
+
+out_page_table_lock:
        spin_unlock(&mm->page_table_lock);
+
+       if (pagecache_page) {
+               unlock_page(pagecache_page);
+               put_page(pagecache_page);
+       }
+
+out_mutex:
        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,
-                       int write)
+                       unsigned int flags)
 {
        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) {
                pte_t *pte;
+               int absent;
                struct page *page;
 
                /*
                 * Some archs (sparc64, sh*) have multiple pte_ts to
-                * each hugepage.  We have to make * sure we get the
+                * 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));
+               absent = !pte || huge_pte_none(huge_ptep_get(pte));
+
+               /*
+                * When coredumping, it suits get_dump_page if we just return
+                * an error where there's an empty slot with no huge pagecache
+                * to back it.  This way, we avoid allocating a hugepage, and
+                * the sparse dumpfile avoids allocating disk blocks, but its
+                * huge holes still show up with zeroes where they need to be.
+                */
+               if (absent && (flags & FOLL_DUMP) &&
+                   !hugetlbfs_pagecache_present(h, vma, vaddr)) {
+                       remainder = 0;
+                       break;
+               }
 
-               if (!pte || huge_pte_none(huge_ptep_get(pte)) ||
-                   (write && !pte_write(huge_ptep_get(pte)))) {
+               if (absent ||
+                   ((flags & FOLL_WRITE) && !pte_write(huge_ptep_get(pte)))) {
                        int ret;
 
                        spin_unlock(&mm->page_table_lock);
-                       ret = hugetlb_fault(mm, vma, vaddr, write);
+                       ret = hugetlb_fault(mm, vma, vaddr,
+                               (flags & FOLL_WRITE) ? FAULT_FLAG_WRITE : 0);
                        spin_lock(&mm->page_table_lock);
                        if (!(ret & VM_FAULT_ERROR))
                                continue;
 
                        remainder = 0;
-                       if (!i)
-                               i = -EFAULT;
                        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) {
-                       get_page(page);
-                       pages[i] = page + pfn_offset;
+                       pages[i] = mem_map_offset(page, pfn_offset);
+                       get_page(pages[i]);
                }
 
                if (vmas)
@@ -1553,7 +2651,7 @@ 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.
@@ -1565,7 +2663,7 @@ same_page:
        *length = remainder;
        *position = vaddr;
 
-       return i;
+       return i ? i : -EFAULT;
 }
 
 void hugetlb_change_protection(struct vm_area_struct *vma,
@@ -1575,13 +2673,14 @@ 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;
@@ -1601,11 +2700,18 @@ void hugetlb_change_protection(struct vm_area_struct *vma,
 
 int hugetlb_reserve_pages(struct inode *inode,
                                        long from, long to,
-                                       struct vm_area_struct *vma)
+                                       struct vm_area_struct *vma,
+                                       int acctflag)
 {
        long ret, chg;
+       struct hstate *h = hstate_inode(inode);
 
-       if (vma && vma->vm_flags & VM_NORESERVE)
+       /*
+        * Only apply hugepage reservation if asked. At fault time, an
+        * attempt will be made for VM_NORESERVE to allocate a page
+        * and filesystem quota without using reserves
+        */
+       if (acctflag & VM_NORESERVE)
                return 0;
 
        /*
@@ -1614,37 +2720,61 @@ int hugetlb_reserve_pages(struct inode *inode,
         * 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 (!vma || vma->vm_flags & VM_SHARED)
+       if (!vma || vma->vm_flags & VM_MAYSHARE)
                chg = region_chg(&inode->i_mapping->private_list, from, to);
        else {
+               struct resv_map *resv_map = resv_map_alloc();
+               if (!resv_map)
+                       return -ENOMEM;
+
                chg = to - from;
-               set_vma_resv_huge_pages(vma, chg);
+
+               set_vma_resv_map(vma, resv_map);
                set_vma_resv_flags(vma, HPAGE_RESV_OWNER);
        }
 
        if (chg < 0)
                return chg;
 
+       /* There must be enough filesystem quota for the mapping */
        if (hugetlb_get_quota(inode->i_mapping, chg))
                return -ENOSPC;
-       ret = hugetlb_acct_memory(chg);
+
+       /*
+        * Check enough hugepages are available for the reservation.
+        * Hand back the quota if there are not
+        */
+       ret = hugetlb_acct_memory(h, chg);
        if (ret < 0) {
                hugetlb_put_quota(inode->i_mapping, chg);
                return ret;
        }
-       if (!vma || vma->vm_flags & VM_SHARED)
+
+       /*
+        * Account for the reservations made. Shared mappings record regions
+        * that have reservations as they are shared by multiple VMAs.
+        * When the last VMA disappears, the region map says how much
+        * the reservation was and the page cache tells how much of
+        * the reservation was consumed. Private mappings are per-VMA and
+        * only the consumed reservations are tracked. When the VMA
+        * disappears, the original reservation is the VMA size and the
+        * consumed reservations are stored in the map. Hence, nothing
+        * else has to be done for private mappings here
+        */
+       if (!vma || vma->vm_flags & VM_MAYSHARE)
                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) * freed);
        spin_unlock(&inode->i_lock);
 
        hugetlb_put_quota(inode->i_mapping, (chg - freed));
-       hugetlb_acct_memory(-(chg - freed));
+       hugetlb_acct_memory(h, -(chg - freed));
 }