1 files changed, 40 insertions, 46 deletions

diff --git a/mm/fremap.c b/mm/fremap.c
index ab23a0673c35..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
@@ -88,29 +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 err_unlock;
+                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.
@@ -124,37 +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.