diff --git a/mm/bootmem.c b/mm/bootmem.c
index a58699b..e8c5671 100644
--- a/mm/bootmem.c
+++ b/mm/bootmem.c
@@ -305,6 +305,7 @@
 				if (j + 16 < BITS_PER_LONG)
 					prefetchw(page + j + 16);
 				__ClearPageReserved(page + j);
+				set_page_count(page + j, 0);
 			}
 			__free_pages(page, order);
 			i += BITS_PER_LONG;
diff --git a/mm/filemap_xip.c b/mm/filemap_xip.c
index 8c199f5..9354ee2 100644
--- a/mm/filemap_xip.c
+++ b/mm/filemap_xip.c
@@ -174,6 +174,7 @@
 	unsigned long address;
 	pte_t *pte;
 	pte_t pteval;
+	struct page *page = ZERO_PAGE(address);
 
 	spin_lock(&mapping->i_mmap_lock);
 	vma_prio_tree_foreach(vma, &iter, &mapping->i_mmap, pgoff, pgoff) {
@@ -185,15 +186,17 @@
 		 * We need the page_table_lock to protect us from page faults,
 		 * munmap, fork, etc...
 		 */
-		pte = page_check_address(ZERO_PAGE(address), mm,
-					 address);
+		pte = page_check_address(page, mm, address);
 		if (!IS_ERR(pte)) {
 			/* Nuke the page table entry. */
 			flush_cache_page(vma, address, pte_pfn(*pte));
 			pteval = ptep_clear_flush(vma, address, pte);
+			page_remove_rmap(page);
+			dec_mm_counter(mm, file_rss);
 			BUG_ON(pte_dirty(pteval));
 			pte_unmap(pte);
 			spin_unlock(&mm->page_table_lock);
+			page_cache_release(page);
 		}
 	}
 	spin_unlock(&mapping->i_mmap_lock);
@@ -228,7 +231,7 @@
 
 	page = mapping->a_ops->get_xip_page(mapping, pgoff*(PAGE_SIZE/512), 0);
 	if (!IS_ERR(page)) {
-		return page;
+		goto out;
 	}
 	if (PTR_ERR(page) != -ENODATA)
 		return NULL;
@@ -249,6 +252,8 @@
 		page = ZERO_PAGE(address);
 	}
 
+out:
+	page_cache_get(page);
 	return page;
 }
 
diff --git a/mm/fremap.c b/mm/fremap.c
index fd7f2a1..224cc15 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -29,19 +29,20 @@
 		return;
 	if (pte_present(pte)) {
 		unsigned long pfn = pte_pfn(pte);
+		struct page *page;
 
 		flush_cache_page(vma, addr, pfn);
 		pte = ptep_clear_flush(vma, addr, ptep);
-		if (pfn_valid(pfn)) {
-			struct page *page = pfn_to_page(pfn);
-			if (!PageReserved(page)) {
-				if (pte_dirty(pte))
-					set_page_dirty(page);
-				page_remove_rmap(page);
-				page_cache_release(page);
-				dec_mm_counter(mm, file_rss);
-			}
+		if (unlikely(!pfn_valid(pfn))) {
+			print_bad_pte(vma, pte, addr);
+			return;
 		}
+		page = pfn_to_page(pfn);
+		if (pte_dirty(pte))
+			set_page_dirty(page);
+		page_remove_rmap(page);
+		page_cache_release(page);
+		dec_mm_counter(mm, file_rss);
 	} else {
 		if (!pte_file(pte))
 			free_swap_and_cache(pte_to_swp_entry(pte));
@@ -65,6 +66,8 @@
 	pgd_t *pgd;
 	pte_t pte_val;
 
+	BUG_ON(vma->vm_flags & VM_RESERVED);
+
 	pgd = pgd_offset(mm, addr);
 	spin_lock(&mm->page_table_lock);
 	
@@ -125,6 +128,8 @@
 	pgd_t *pgd;
 	pte_t pte_val;
 
+	BUG_ON(vma->vm_flags & VM_RESERVED);
+
 	pgd = pgd_offset(mm, addr);
 	spin_lock(&mm->page_table_lock);
 	
diff --git a/mm/madvise.c b/mm/madvise.c
index 20e075d..17aaf3e 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -126,7 +126,7 @@
 			     unsigned long start, unsigned long end)
 {
 	*prev = vma;
-	if ((vma->vm_flags & VM_LOCKED) || is_vm_hugetlb_page(vma))
+	if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_RESERVED))
 		return -EINVAL;
 
 	if (unlikely(vma->vm_flags & VM_NONLINEAR)) {
diff --git a/mm/memory.c b/mm/memory.c
index da642b5..e83f944 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -343,6 +343,23 @@
 #define NO_RSS 2	/* Increment neither file_rss nor anon_rss */
 
 /*
+ * This function is called to print an error when a pte in a
+ * !VM_RESERVED region is found pointing to an invalid pfn (which
+ * is an error.
+ *
+ * The calling function must still handle the error.
+ */
+void print_bad_pte(struct vm_area_struct *vma, pte_t pte, unsigned long vaddr)
+{
+	printk(KERN_ERR "Bad pte = %08llx, process = %s, "
+			"vm_flags = %lx, vaddr = %lx\n",
+		(long long)pte_val(pte),
+		(vma->vm_mm == current->mm ? current->comm : "???"),
+		vma->vm_flags, vaddr);
+	dump_stack();
+}
+
+/*
  * copy one vm_area from one task to the other. Assumes the page tables
  * already present in the new task to be cleared in the whole range
  * covered by this vma.
@@ -353,9 +370,10 @@
 
 static inline int
 copy_one_pte(struct mm_struct *dst_mm, struct mm_struct *src_mm,
-		pte_t *dst_pte, pte_t *src_pte, unsigned long vm_flags,
+		pte_t *dst_pte, pte_t *src_pte, struct vm_area_struct *vma,
 		unsigned long addr)
 {
+	unsigned long vm_flags = vma->vm_flags;
 	pte_t pte = *src_pte;
 	struct page *page;
 	unsigned long pfn;
@@ -375,19 +393,23 @@
 		goto out_set_pte;
 	}
 
-	pfn = pte_pfn(pte);
-	/* the pte points outside of valid memory, the
-	 * mapping is assumed to be good, meaningful
-	 * and not mapped via rmap - duplicate the
-	 * mapping as is.
+	/* If the region is VM_RESERVED, the mapping is not
+	 * mapped via rmap - duplicate the pte as is.
 	 */
-	page = NULL;
-	if (pfn_valid(pfn))
-		page = pfn_to_page(pfn);
-
-	if (!page || PageReserved(page))
+	if (vm_flags & VM_RESERVED)
 		goto out_set_pte;
 
+	pfn = pte_pfn(pte);
+	/* If the pte points outside of valid memory but
+	 * the region is not VM_RESERVED, we have a problem.
+	 */
+	if (unlikely(!pfn_valid(pfn))) {
+		print_bad_pte(vma, pte, addr);
+		goto out_set_pte; /* try to do something sane */
+	}
+
+	page = pfn_to_page(pfn);
+
 	/*
 	 * If it's a COW mapping, write protect it both
 	 * in the parent and the child
@@ -418,7 +440,6 @@
 		unsigned long addr, unsigned long end)
 {
 	pte_t *src_pte, *dst_pte;
-	unsigned long vm_flags = vma->vm_flags;
 	int progress = 0;
 	int rss[NO_RSS+1], anon;
 
@@ -446,8 +467,7 @@
 			progress++;
 			continue;
 		}
-		anon = copy_one_pte(dst_mm, src_mm, dst_pte, src_pte,
-							vm_flags, addr);
+		anon = copy_one_pte(dst_mm, src_mm, dst_pte, src_pte, vma,addr);
 		rss[anon]++;
 		progress += 8;
 	} while (dst_pte++, src_pte++, addr += PAGE_SIZE, addr != end);
@@ -541,10 +561,12 @@
 	return 0;
 }
 
-static void zap_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
+static void zap_pte_range(struct mmu_gather *tlb,
+				struct vm_area_struct *vma, pmd_t *pmd,
 				unsigned long addr, unsigned long end,
 				struct zap_details *details)
 {
+	struct mm_struct *mm = tlb->mm;
 	pte_t *pte;
 	int file_rss = 0;
 	int anon_rss = 0;
@@ -556,11 +578,12 @@
 			continue;
 		if (pte_present(ptent)) {
 			struct page *page = NULL;
-			unsigned long pfn = pte_pfn(ptent);
-			if (pfn_valid(pfn)) {
-				page = pfn_to_page(pfn);
-				if (PageReserved(page))
-					page = NULL;
+			if (!(vma->vm_flags & VM_RESERVED)) {
+				unsigned long pfn = pte_pfn(ptent);
+				if (unlikely(!pfn_valid(pfn)))
+					print_bad_pte(vma, ptent, addr);
+				else
+					page = pfn_to_page(pfn);
 			}
 			if (unlikely(details) && page) {
 				/*
@@ -580,7 +603,7 @@
 				     page->index > details->last_index))
 					continue;
 			}
-			ptent = ptep_get_and_clear_full(tlb->mm, addr, pte,
+			ptent = ptep_get_and_clear_full(mm, addr, pte,
 							tlb->fullmm);
 			tlb_remove_tlb_entry(tlb, pte, addr);
 			if (unlikely(!page))
@@ -588,7 +611,7 @@
 			if (unlikely(details) && details->nonlinear_vma
 			    && linear_page_index(details->nonlinear_vma,
 						addr) != page->index)
-				set_pte_at(tlb->mm, addr, pte,
+				set_pte_at(mm, addr, pte,
 					   pgoff_to_pte(page->index));
 			if (PageAnon(page))
 				anon_rss++;
@@ -611,14 +634,15 @@
 			continue;
 		if (!pte_file(ptent))
 			free_swap_and_cache(pte_to_swp_entry(ptent));
-		pte_clear_full(tlb->mm, addr, pte, tlb->fullmm);
+		pte_clear_full(mm, addr, pte, tlb->fullmm);
 	} while (pte++, addr += PAGE_SIZE, addr != end);
 
-	add_mm_rss(tlb->mm, -file_rss, -anon_rss);
+	add_mm_rss(mm, -file_rss, -anon_rss);
 	pte_unmap(pte - 1);
 }
 
-static inline void zap_pmd_range(struct mmu_gather *tlb, pud_t *pud,
+static inline void zap_pmd_range(struct mmu_gather *tlb,
+				struct vm_area_struct *vma, pud_t *pud,
 				unsigned long addr, unsigned long end,
 				struct zap_details *details)
 {
@@ -630,11 +654,12 @@
 		next = pmd_addr_end(addr, end);
 		if (pmd_none_or_clear_bad(pmd))
 			continue;
-		zap_pte_range(tlb, pmd, addr, next, details);
+		zap_pte_range(tlb, vma, pmd, addr, next, details);
 	} while (pmd++, addr = next, addr != end);
 }
 
-static inline void zap_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
+static inline void zap_pud_range(struct mmu_gather *tlb,
+				struct vm_area_struct *vma, pgd_t *pgd,
 				unsigned long addr, unsigned long end,
 				struct zap_details *details)
 {
@@ -646,7 +671,7 @@
 		next = pud_addr_end(addr, end);
 		if (pud_none_or_clear_bad(pud))
 			continue;
-		zap_pmd_range(tlb, pud, addr, next, details);
+		zap_pmd_range(tlb, vma, pud, addr, next, details);
 	} while (pud++, addr = next, addr != end);
 }
 
@@ -667,7 +692,7 @@
 		next = pgd_addr_end(addr, end);
 		if (pgd_none_or_clear_bad(pgd))
 			continue;
-		zap_pud_range(tlb, pgd, addr, next, details);
+		zap_pud_range(tlb, vma, pgd, addr, next, details);
 	} while (pgd++, addr = next, addr != end);
 	tlb_end_vma(tlb, vma);
 }
@@ -967,7 +992,7 @@
 			continue;
 		}
 
-		if (!vma || (vma->vm_flags & VM_IO)
+		if (!vma || (vma->vm_flags & (VM_IO | VM_RESERVED))
 				|| !(flags & vma->vm_flags))
 			return i ? : -EFAULT;
 
@@ -1027,8 +1052,7 @@
 			if (pages) {
 				pages[i] = page;
 				flush_dcache_page(page);
-				if (!PageReserved(page))
-					page_cache_get(page);
+				page_cache_get(page);
 			}
 			if (vmas)
 				vmas[i] = vma;
@@ -1051,7 +1075,11 @@
 	if (!pte)
 		return -ENOMEM;
 	do {
-		pte_t zero_pte = pte_wrprotect(mk_pte(ZERO_PAGE(addr), prot));
+		struct page *page = ZERO_PAGE(addr);
+		pte_t zero_pte = pte_wrprotect(mk_pte(page, prot));
+		page_cache_get(page);
+		page_add_file_rmap(page);
+		inc_mm_counter(mm, file_rss);
 		BUG_ON(!pte_none(*pte));
 		set_pte_at(mm, addr, pte, zero_pte);
 	} while (pte++, addr += PAGE_SIZE, addr != end);
@@ -1132,8 +1160,7 @@
 		return -ENOMEM;
 	do {
 		BUG_ON(!pte_none(*pte));
-		if (!pfn_valid(pfn) || PageReserved(pfn_to_page(pfn)))
-			set_pte_at(mm, addr, pte, pfn_pte(pfn, prot));
+		set_pte_at(mm, addr, pte, pfn_pte(pfn, prot));
 		pfn++;
 	} while (pte++, addr += PAGE_SIZE, addr != end);
 	pte_unmap(pte - 1);
@@ -1195,8 +1222,8 @@
 	 * rest of the world about it:
 	 *   VM_IO tells people not to look at these pages
 	 *	(accesses can have side effects).
-	 *   VM_RESERVED tells swapout not to try to touch
-	 *	this region.
+	 *   VM_RESERVED tells the core MM not to "manage" these pages
+         *	(e.g. refcount, mapcount, try to swap them out).
 	 */
 	vma->vm_flags |= VM_IO | VM_RESERVED;
 
@@ -1256,11 +1283,13 @@
 	pte_t entry;
 	int ret = VM_FAULT_MINOR;
 
+	BUG_ON(vma->vm_flags & VM_RESERVED);
+
 	if (unlikely(!pfn_valid(pfn))) {
 		/*
 		 * Page table corrupted: show pte and kill process.
 		 */
-		pte_ERROR(orig_pte);
+		print_bad_pte(vma, orig_pte, address);
 		ret = VM_FAULT_OOM;
 		goto unlock;
 	}
@@ -1284,8 +1313,7 @@
 	/*
 	 * Ok, we need to copy. Oh, well..
 	 */
-	if (!PageReserved(old_page))
-		page_cache_get(old_page);
+	page_cache_get(old_page);
 	pte_unmap(page_table);
 	spin_unlock(&mm->page_table_lock);
 
@@ -1308,14 +1336,10 @@
 	spin_lock(&mm->page_table_lock);
 	page_table = pte_offset_map(pmd, address);
 	if (likely(pte_same(*page_table, orig_pte))) {
-		if (PageReserved(old_page))
+		page_remove_rmap(old_page);
+		if (!PageAnon(old_page)) {
 			inc_mm_counter(mm, anon_rss);
-		else {
-			page_remove_rmap(old_page);
-			if (!PageAnon(old_page)) {
-				inc_mm_counter(mm, anon_rss);
-				dec_mm_counter(mm, file_rss);
-			}
+			dec_mm_counter(mm, file_rss);
 		}
 		flush_cache_page(vma, address, pfn);
 		entry = mk_pte(new_page, vma->vm_page_prot);
@@ -1769,14 +1793,13 @@
 		unsigned long address, pte_t *page_table, pmd_t *pmd,
 		int write_access)
 {
+	struct page *page = ZERO_PAGE(addr);
 	pte_t entry;
 
 	/* Mapping of ZERO_PAGE - vm_page_prot is readonly */
-	entry = mk_pte(ZERO_PAGE(addr), vma->vm_page_prot);
+	entry = mk_pte(page, vma->vm_page_prot);
 
 	if (write_access) {
-		struct page *page;
-
 		/* Allocate our own private page. */
 		pte_unmap(page_table);
 		spin_unlock(&mm->page_table_lock);
@@ -1800,6 +1823,10 @@
 		lru_cache_add_active(page);
 		SetPageReferenced(page);
 		page_add_anon_rmap(page, vma, address);
+	} else {
+		inc_mm_counter(mm, file_rss);
+		page_add_file_rmap(page);
+		page_cache_get(page);
 	}
 
 	set_pte_at(mm, address, page_table, entry);
@@ -1916,7 +1943,7 @@
 			inc_mm_counter(mm, anon_rss);
 			lru_cache_add_active(new_page);
 			page_add_anon_rmap(new_page, vma, address);
-		} else if (!PageReserved(new_page)) {
+		} else if (!(vma->vm_flags & VM_RESERVED)) {
 			inc_mm_counter(mm, file_rss);
 			page_add_file_rmap(new_page);
 		}
@@ -1957,7 +1984,7 @@
 		/*
 		 * Page table corrupted: show pte and kill process.
 		 */
-		pte_ERROR(orig_pte);
+		print_bad_pte(vma, orig_pte, address);
 		return VM_FAULT_OOM;
 	}
 	/* We can then assume vm->vm_ops && vma->vm_ops->populate */
@@ -2232,7 +2259,7 @@
 	gate_vma.vm_start = FIXADDR_USER_START;
 	gate_vma.vm_end = FIXADDR_USER_END;
 	gate_vma.vm_page_prot = PAGE_READONLY;
-	gate_vma.vm_flags = 0;
+	gate_vma.vm_flags = VM_RESERVED;
 	return 0;
 }
 __initcall(gate_vma_init);
diff --git a/mm/mempolicy.c b/mm/mempolicy.c
index 43b1199..11d824f 100644
--- a/mm/mempolicy.c
+++ b/mm/mempolicy.c
@@ -223,13 +223,13 @@
 }
 
 /* Ensure all existing pages follow the policy. */
-static int check_pte_range(struct mm_struct *mm, pmd_t *pmd,
+static int check_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 		unsigned long addr, unsigned long end, nodemask_t *nodes)
 {
 	pte_t *orig_pte;
 	pte_t *pte;
 
-	spin_lock(&mm->page_table_lock);
+	spin_lock(&vma->vm_mm->page_table_lock);
 	orig_pte = pte = pte_offset_map(pmd, addr);
 	do {
 		unsigned long pfn;
@@ -238,18 +238,20 @@
 		if (!pte_present(*pte))
 			continue;
 		pfn = pte_pfn(*pte);
-		if (!pfn_valid(pfn))
+		if (!pfn_valid(pfn)) {
+			print_bad_pte(vma, *pte, addr);
 			continue;
+		}
 		nid = pfn_to_nid(pfn);
 		if (!node_isset(nid, *nodes))
 			break;
 	} while (pte++, addr += PAGE_SIZE, addr != end);
 	pte_unmap(orig_pte);
-	spin_unlock(&mm->page_table_lock);
+	spin_unlock(&vma->vm_mm->page_table_lock);
 	return addr != end;
 }
 
-static inline int check_pmd_range(struct mm_struct *mm, pud_t *pud,
+static inline int check_pmd_range(struct vm_area_struct *vma, pud_t *pud,
 		unsigned long addr, unsigned long end, nodemask_t *nodes)
 {
 	pmd_t *pmd;
@@ -260,13 +262,13 @@
 		next = pmd_addr_end(addr, end);
 		if (pmd_none_or_clear_bad(pmd))
 			continue;
-		if (check_pte_range(mm, pmd, addr, next, nodes))
+		if (check_pte_range(vma, pmd, addr, next, nodes))
 			return -EIO;
 	} while (pmd++, addr = next, addr != end);
 	return 0;
 }
 
-static inline int check_pud_range(struct mm_struct *mm, pgd_t *pgd,
+static inline int check_pud_range(struct vm_area_struct *vma, pgd_t *pgd,
 		unsigned long addr, unsigned long end, nodemask_t *nodes)
 {
 	pud_t *pud;
@@ -277,24 +279,24 @@
 		next = pud_addr_end(addr, end);
 		if (pud_none_or_clear_bad(pud))
 			continue;
-		if (check_pmd_range(mm, pud, addr, next, nodes))
+		if (check_pmd_range(vma, pud, addr, next, nodes))
 			return -EIO;
 	} while (pud++, addr = next, addr != end);
 	return 0;
 }
 
-static inline int check_pgd_range(struct mm_struct *mm,
+static inline int check_pgd_range(struct vm_area_struct *vma,
 		unsigned long addr, unsigned long end, nodemask_t *nodes)
 {
 	pgd_t *pgd;
 	unsigned long next;
 
-	pgd = pgd_offset(mm, addr);
+	pgd = pgd_offset(vma->vm_mm, addr);
 	do {
 		next = pgd_addr_end(addr, end);
 		if (pgd_none_or_clear_bad(pgd))
 			continue;
-		if (check_pud_range(mm, pgd, addr, next, nodes))
+		if (check_pud_range(vma, pgd, addr, next, nodes))
 			return -EIO;
 	} while (pgd++, addr = next, addr != end);
 	return 0;
@@ -311,6 +313,8 @@
 	first = find_vma(mm, start);
 	if (!first)
 		return ERR_PTR(-EFAULT);
+	if (first->vm_flags & VM_RESERVED)
+		return ERR_PTR(-EACCES);
 	prev = NULL;
 	for (vma = first; vma && vma->vm_start < end; vma = vma->vm_next) {
 		if (!vma->vm_next && vma->vm_end < end)
@@ -323,8 +327,7 @@
 				endvma = end;
 			if (vma->vm_start > start)
 				start = vma->vm_start;
-			err = check_pgd_range(vma->vm_mm,
-					   start, endvma, nodes);
+			err = check_pgd_range(vma, start, endvma, nodes);
 			if (err) {
 				first = ERR_PTR(err);
 				break;
diff --git a/mm/mmap.c b/mm/mmap.c
index 459b9f0..8a11179 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1088,6 +1088,17 @@
 		error = file->f_op->mmap(file, vma);
 		if (error)
 			goto unmap_and_free_vma;
+		if ((vma->vm_flags & (VM_SHARED | VM_WRITE | VM_RESERVED))
+						== (VM_WRITE | VM_RESERVED)) {
+			printk(KERN_WARNING "program %s is using MAP_PRIVATE, "
+				"PROT_WRITE mmap of VM_RESERVED memory, which "
+				"is deprecated. Please report this to "
+				"linux-kernel@vger.kernel.org\n",current->comm);
+			if (vma->vm_ops && vma->vm_ops->close)
+				vma->vm_ops->close(vma);
+			error = -EACCES;
+			goto unmap_and_free_vma;
+		}
 	} else if (vm_flags & VM_SHARED) {
 		error = shmem_zero_setup(vma);
 		if (error)
diff --git a/mm/mprotect.c b/mm/mprotect.c
index b426f01..672a76f 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -125,6 +125,14 @@
 	 * a MAP_NORESERVE private mapping to writable will now reserve.
 	 */
 	if (newflags & VM_WRITE) {
+		if (oldflags & VM_RESERVED) {
+			BUG_ON(oldflags & VM_WRITE);
+			printk(KERN_WARNING "program %s is using MAP_PRIVATE, "
+				"PROT_WRITE mprotect of VM_RESERVED memory, "
+				"which is deprecated. Please report this to "
+				"linux-kernel@vger.kernel.org\n",current->comm);
+			return -EACCES;
+		}
 		if (!(oldflags & (VM_ACCOUNT|VM_WRITE|VM_SHARED|VM_HUGETLB))) {
 			charged = nrpages;
 			if (security_vm_enough_memory(charged))
diff --git a/mm/msync.c b/mm/msync.c
index 3b5f1c5..8603954 100644
--- a/mm/msync.c
+++ b/mm/msync.c
@@ -25,6 +25,7 @@
 static void msync_pte_range(struct vm_area_struct *vma, pmd_t *pmd,
 				unsigned long addr, unsigned long end)
 {
+	struct mm_struct *mm = vma->vm_mm;
 	pte_t *pte;
 	int progress = 0;
 
@@ -37,7 +38,7 @@
 		if (progress >= 64) {
 			progress = 0;
 			if (need_resched() ||
-			    need_lockbreak(&vma->vm_mm->page_table_lock))
+			    need_lockbreak(&mm->page_table_lock))
 				break;
 		}
 		progress++;
@@ -46,11 +47,11 @@
 		if (!pte_maybe_dirty(*pte))
 			continue;
 		pfn = pte_pfn(*pte);
-		if (!pfn_valid(pfn))
+		if (unlikely(!pfn_valid(pfn))) {
+			print_bad_pte(vma, *pte, addr);
 			continue;
+		}
 		page = pfn_to_page(pfn);
-		if (PageReserved(page))
-			continue;
 
 		if (ptep_clear_flush_dirty(vma, addr, pte) ||
 		    page_test_and_clear_dirty(page))
@@ -58,7 +59,7 @@
 		progress += 3;
 	} while (pte++, addr += PAGE_SIZE, addr != end);
 	pte_unmap(pte - 1);
-	cond_resched_lock(&vma->vm_mm->page_table_lock);
+	cond_resched_lock(&mm->page_table_lock);
 	if (addr != end)
 		goto again;
 }
@@ -102,8 +103,10 @@
 
 	/* For hugepages we can't go walking the page table normally,
 	 * but that's ok, hugetlbfs is memory based, so we don't need
-	 * to do anything more on an msync() */
-	if (is_vm_hugetlb_page(vma))
+	 * to do anything more on an msync().
+	 * Can't do anything with VM_RESERVED regions either.
+	 */
+	if (vma->vm_flags & (VM_HUGETLB|VM_RESERVED))
 		return;
 
 	BUG_ON(addr >= end);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 6066323..0541288 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -114,7 +114,8 @@
 			1 << PG_reclaim |
 			1 << PG_slab    |
 			1 << PG_swapcache |
-			1 << PG_writeback);
+			1 << PG_writeback |
+			1 << PG_reserved );
 	set_page_count(page, 0);
 	reset_page_mapcount(page);
 	page->mapping = NULL;
@@ -244,7 +245,6 @@
 {
        if (PagePrivate(page)           &&
            (page_order(page) == order) &&
-           !PageReserved(page)         &&
             page_count(page) == 0)
                return 1;
        return 0;
@@ -327,7 +327,8 @@
 			1 << PG_reclaim	|
 			1 << PG_slab	|
 			1 << PG_swapcache |
-			1 << PG_writeback )))
+			1 << PG_writeback |
+			1 << PG_reserved )))
 		bad_page(function, page);
 	if (PageDirty(page))
 		__ClearPageDirty(page);
@@ -455,7 +456,8 @@
 			1 << PG_reclaim	|
 			1 << PG_slab    |
 			1 << PG_swapcache |
-			1 << PG_writeback )))
+			1 << PG_writeback |
+			1 << PG_reserved )))
 		bad_page(__FUNCTION__, page);
 
 	page->flags &= ~(1 << PG_uptodate | 1 << PG_error |
@@ -1016,7 +1018,7 @@
 
 fastcall void __free_pages(struct page *page, unsigned int order)
 {
-	if (!PageReserved(page) && put_page_testzero(page)) {
+	if (put_page_testzero(page)) {
 		if (order == 0)
 			free_hot_page(page);
 		else
@@ -1674,7 +1676,7 @@
 			continue;
 		page = pfn_to_page(pfn);
 		set_page_links(page, zone, nid, pfn);
-		set_page_count(page, 0);
+		set_page_count(page, 1);
 		reset_page_mapcount(page);
 		SetPageReserved(page);
 		INIT_LIST_HEAD(&page->lru);
diff --git a/mm/rmap.c b/mm/rmap.c
index 5047576..f69d534 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -443,8 +443,6 @@
 void page_add_anon_rmap(struct page *page,
 	struct vm_area_struct *vma, unsigned long address)
 {
-	BUG_ON(PageReserved(page));
-
 	if (atomic_inc_and_test(&page->_mapcount)) {
 		struct anon_vma *anon_vma = vma->anon_vma;
 
@@ -468,8 +466,7 @@
 void page_add_file_rmap(struct page *page)
 {
 	BUG_ON(PageAnon(page));
-	if (!pfn_valid(page_to_pfn(page)) || PageReserved(page))
-		return;
+	BUG_ON(!pfn_valid(page_to_pfn(page)));
 
 	if (atomic_inc_and_test(&page->_mapcount))
 		inc_page_state(nr_mapped);
@@ -483,8 +480,6 @@
  */
 void page_remove_rmap(struct page *page)
 {
-	BUG_ON(PageReserved(page));
-
 	if (atomic_add_negative(-1, &page->_mapcount)) {
 		BUG_ON(page_mapcount(page) < 0);
 		/*
@@ -640,13 +635,13 @@
 			continue;
 
 		pfn = pte_pfn(*pte);
-		if (!pfn_valid(pfn))
+		if (unlikely(!pfn_valid(pfn))) {
+			print_bad_pte(vma, *pte, address);
 			continue;
+		}
 
 		page = pfn_to_page(pfn);
 		BUG_ON(PageAnon(page));
-		if (PageReserved(page))
-			continue;
 
 		if (ptep_clear_flush_young(vma, address, pte))
 			continue;
@@ -808,7 +803,6 @@
 {
 	int ret;
 
-	BUG_ON(PageReserved(page));
 	BUG_ON(!PageLocked(page));
 
 	if (PageAnon(page))
diff --git a/mm/shmem.c b/mm/shmem.c
index 6796311..37777f4 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1506,8 +1506,10 @@
 			 */
 			if (!offset)
 				mark_page_accessed(page);
-		} else
+		} else {
 			page = ZERO_PAGE(0);
+			page_cache_get(page);
+		}
 
 		/*
 		 * Ok, we have the page, and it's up-to-date, so
diff --git a/mm/swap.c b/mm/swap.c
index 7771d28..21d15f9 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -48,7 +48,7 @@
 		}
 		return;
 	}
-	if (!PageReserved(page) && put_page_testzero(page))
+	if (put_page_testzero(page))
 		__page_cache_release(page);
 }
 EXPORT_SYMBOL(put_page);
@@ -215,7 +215,7 @@
 		struct page *page = pages[i];
 		struct zone *pagezone;
 
-		if (PageReserved(page) || !put_page_testzero(page))
+		if (!put_page_testzero(page))
 			continue;
 
 		pagezone = page_zone(page);