1 files changed, 42 insertions, 45 deletions

diff --git a/mm/fremap.c b/mm/fremap.c
index 3235fb77c133..d862be3bc3e3 100644
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -20,33 +20,32 @@
 #include <asm/cacheflush.h>
 #include <asm/tlbflush.h>
 
-static inline void zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
+static int zap_pte(struct mm_struct *mm, struct vm_area_struct *vma,
 			unsigned long addr, pte_t *ptep)
 {
 	pte_t pte = *ptep;
+	struct page *page = NULL;
 
-	if (pte_none(pte))
-		return;
 	if (pte_present(pte)) {
 		unsigned long pfn = pte_pfn(pte);
-
 		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, rss);
-			}
+		if (unlikely(!pfn_valid(pfn))) {
+			print_bad_pte(vma, pte, addr);
+			goto out;
 		}
+		page = pfn_to_page(pfn);
+		if (pte_dirty(pte))
+			set_page_dirty(page);
+		page_remove_rmap(page);
+		page_cache_release(page);
 	} else {
 		if (!pte_file(pte))
 			free_swap_and_cache(pte_to_swp_entry(pte));
 		pte_clear(mm, addr, ptep);
 	}
+out:
+	return !!page;
 }
 
 /*
@@ -64,21 +63,20 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	pud_t *pud;
 	pgd_t *pgd;
 	pte_t pte_val;
+	spinlock_t *ptl;
+
+	BUG_ON(vma->vm_flags & VM_RESERVED);
 
 	pgd = pgd_offset(mm, addr);
-	spin_lock(&mm->page_table_lock);
-	
 	pud = pud_alloc(mm, pgd, addr);
 	if (!pud)
-		goto err_unlock;
-
+		goto out;
 	pmd = pmd_alloc(mm, pud, addr);
 	if (!pmd)
-		goto err_unlock;
-
-	pte = pte_alloc_map(mm, pmd, addr);
+		goto out;
+	pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
 	if (!pte)
-		goto err_unlock;
+		goto out;
 
 	/*
 	 * This page may have been truncated. Tell the
@@ -88,26 +86,27 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma,
 	inode = vma->vm_file->f_mapping->host;
 	size = (i_size_read(inode) + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 	if (!page->mapping || page->index >= size)
-		goto err_unlock;
+		goto unlock;
+	err = -ENOMEM;
+	if (page_mapcount(page) > INT_MAX/2)
+		goto unlock;
 
-	zap_pte(mm, vma, addr, pte);
+	if (pte_none(*pte) || !zap_pte(mm, vma, addr, pte))
+		inc_mm_counter(mm, file_rss);
 
-	inc_mm_counter(mm,rss);
 	flush_icache_page(vma, page);
 	set_pte_at(mm, addr, pte, mk_pte(page, prot));
 	page_add_file_rmap(page);
 	pte_val = *pte;
-	pte_unmap(pte);
 	update_mmu_cache(vma, addr, pte_val);
-
 	err = 0;
-err_unlock:
-	spin_unlock(&mm->page_table_lock);
+unlock:
+	pte_unmap_unlock(pte, ptl);
+out:
 	return err;
 }
 EXPORT_SYMBOL(install_page);
 
-
 /*
  * Install a file pte to a given virtual memory address, release any
  * previously existing mapping.
@@ -121,37 +120,35 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma,
 	pud_t *pud;
 	pgd_t *pgd;
 	pte_t pte_val;
+	spinlock_t *ptl;
+
+	BUG_ON(vma->vm_flags & VM_RESERVED);
 
 	pgd = pgd_offset(mm, addr);
-	spin_lock(&mm->page_table_lock);
-	
 	pud = pud_alloc(mm, pgd, addr);
 	if (!pud)
-		goto err_unlock;
-
+		goto out;
 	pmd = pmd_alloc(mm, pud, addr);
 	if (!pmd)
-		goto err_unlock;
-
-	pte = pte_alloc_map(mm, pmd, addr);
+		goto out;
+	pte = pte_alloc_map_lock(mm, pmd, addr, &ptl);
 	if (!pte)
-		goto err_unlock;
+		goto out;
 
-	zap_pte(mm, vma, addr, pte);
+	if (!pte_none(*pte) && zap_pte(mm, vma, addr, pte)) {
+		update_hiwater_rss(mm);
+		dec_mm_counter(mm, file_rss);
+	}
 
 	set_pte_at(mm, addr, pte, pgoff_to_pte(pgoff));
 	pte_val = *pte;
-	pte_unmap(pte);
 	update_mmu_cache(vma, addr, pte_val);
-	spin_unlock(&mm->page_table_lock);
-	return 0;
-
-err_unlock:
-	spin_unlock(&mm->page_table_lock);
+	pte_unmap_unlock(pte, ptl);
+	err = 0;
+out:
 	return err;
 }
 
-
 /***
  * sys_remap_file_pages - remap arbitrary pages of a shared backing store
  *                        file within an existing vma.