Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

[linux-2.6.git] / mm / fremap.c

diff --git a/mm/fremap.c b/mm/fremap.c
index be09f92..653b56f 100644 (file)
--- a/mm/fremap.c
+++ b/mm/fremap.c
@@ -21,33 +21,29 @@
 #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);
+               flush_cache_page(vma, addr, pte_pfn(pte));
                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);
-                       }
+               page = vm_normal_page(vma, addr, pte);
+               if (page) {
+                       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));
                pte_clear(mm, addr, ptep);
        }
+       return !!page;
 }
 
 /*
@@ -61,57 +57,46 @@ int install_page(struct mm_struct *mm, struct vm_area_struct *vma,
        pgoff_t size;
        int err = -ENOMEM;
        pte_t *pte;
-       pmd_t *pmd;
-       pud_t *pud;
-       pgd_t *pgd;
        pte_t pte_val;
+       spinlock_t *ptl;
 
-       pgd = pgd_offset(mm, addr);
-       spin_lock(&mm->page_table_lock);
-
-       if (!vx_rsspages_avail(mm, 1))
-               goto err_unlock;
-       
-       pud = pud_alloc(mm, pgd, addr);
-       if (!pud)
-               goto err_unlock;
-
-       pmd = pmd_alloc(mm, pud, addr);
-       if (!pmd)
-               goto err_unlock;
-
-       pte = pte_alloc_map(mm, pmd, addr);
+       pte = get_locked_pte(mm, addr, &ptl);
        if (!pte)
-               goto err_unlock;
+               goto out;
 
        /*
         * This page may have been truncated. Tell the
         * caller about it.
         */
        err = -EINVAL;
-       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;
+       if (vma->vm_file) {
+               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 unlock;
+               err = -ENOMEM;
+               if (page_mapcount(page) > INT_MAX/2)
+                       goto unlock;
+               if (!vx_rsspages_avail(mm, 1))
+                       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.
@@ -121,41 +106,27 @@ int install_file_pte(struct mm_struct *mm, struct vm_area_struct *vma,
 {
        int err = -ENOMEM;
        pte_t *pte;
-       pmd_t *pmd;
-       pud_t *pud;
-       pgd_t *pgd;
        pte_t pte_val;
+       spinlock_t *ptl;
 
-       pgd = pgd_offset(mm, addr);
-       spin_lock(&mm->page_table_lock);
-       
-       pud = pud_alloc(mm, pgd, addr);
-       if (!pud)
-               goto err_unlock;
-
-       pmd = pmd_alloc(mm, pud, addr);
-       if (!pmd)
-               goto err_unlock;
-
-       pte = pte_alloc_map(mm, pmd, addr);
+       pte = get_locked_pte(mm, 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.
@@ -211,12 +182,10 @@ asmlinkage long sys_remap_file_pages(unsigned long start, unsigned long size,
         * Make sure the vma is shared, that it supports prefaulting,
         * and that the remapped range is valid and fully within
         * the single existing vma.  vm_private_data is used as a
-        * swapout cursor in a VM_NONLINEAR vma (unless VM_RESERVED
-        * or VM_LOCKED, but VM_LOCKED could be revoked later on).
+        * swapout cursor in a VM_NONLINEAR vma.
         */
        if (vma && (vma->vm_flags & VM_SHARED) &&
-               (!vma->vm_private_data ||
-                       (vma->vm_flags & (VM_NONLINEAR|VM_RESERVED))) &&
+               (!vma->vm_private_data || (vma->vm_flags & VM_NONLINEAR)) &&
                vma->vm_ops && vma->vm_ops->populate &&
                        end > start && start >= vma->vm_start &&
                                end <= vma->vm_end) {