-/*
- * Some shared mappigns will want the pages marked read-only
- * to track write events. If so, we'll downgrade vm_page_prot
- * to the private version (using protection_map[] without the
- * VM_SHARED bit).
- */
-static inline int vma_wants_writenotify(struct vm_area_struct *vma)
-{
- unsigned int vm_flags = vma->vm_flags;
-
- /* If it was private or non-writable, the write bit is already clear */
- if ((vm_flags & (VM_WRITE|VM_SHARED)) != ((VM_WRITE|VM_SHARED)))
- return 0;
-
- /* The backer wishes to know when pages are first written to? */
- if (vma->vm_ops && vma->vm_ops->page_mkwrite)
- return 1;
-
- /* The open routine did something to the protections already? */
- if (pgprot_val(vma->vm_page_prot) !=
- pgprot_val(protection_map[vm_flags &
- (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]))
- return 0;
-
- /* Specialty mapping? */
- if (vm_flags & (VM_PFNMAP|VM_INSERTPAGE))
- return 0;
-
- /* Can the mapping track the dirty pages? */
- return vma->vm_file && vma->vm_file->f_mapping &&
- mapping_cap_account_dirty(vma->vm_file->f_mapping);
-}
-