[PATCH] mm: tracking shared dirty pages

[linux-2.6-microblaze.git] / mm / mprotect.c

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 638edab..367b7f6 100644 (file)
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -123,8 +123,6 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
        unsigned long oldflags = vma->vm_flags;
        long nrpages = (end - start) >> PAGE_SHIFT;
        unsigned long charged = 0;
-       unsigned int mask;
-       pgprot_t newprot;
        pgoff_t pgoff;
        int error;
 
@@ -176,24 +174,21 @@ mprotect_fixup(struct vm_area_struct *vma, struct vm_area_struct **pprev,
        }
 
 success:
-       /* Don't make the VMA automatically writable if it's shared, but the
-        * backer wishes to know when pages are first written to */
-       mask = VM_READ|VM_WRITE|VM_EXEC|VM_SHARED;
-       if (vma->vm_ops && vma->vm_ops->page_mkwrite)
-               mask &= ~VM_SHARED;
-
-       newprot = protection_map[newflags & mask];
-
        /*
         * vm_flags and vm_page_prot are protected by the mmap_sem
         * held in write mode.
         */
        vma->vm_flags = newflags;
-       vma->vm_page_prot = newprot;
+       vma->vm_page_prot = protection_map[newflags &
+               (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)];
+       if (vma_wants_writenotify(vma))
+               vma->vm_page_prot = protection_map[newflags &
+                       (VM_READ|VM_WRITE|VM_EXEC)];
+
        if (is_vm_hugetlb_page(vma))
-               hugetlb_change_protection(vma, start, end, newprot);
+               hugetlb_change_protection(vma, start, end, vma->vm_page_prot);
        else
-               change_protection(vma, start, end, newprot);
+               change_protection(vma, start, end, vma->vm_page_prot);
        vm_stat_account(mm, oldflags, vma->vm_file, -nrpages);
        vm_stat_account(mm, newflags, vma->vm_file, nrpages);
        return 0;