1 files changed, 11 insertions, 3 deletions

diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index c0c2bce6b0b7..c4c559a45dc8 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -37,6 +37,16 @@ struct anon_vma {
         atomic_t refcount;
 
         /*
+         * Count of child anon_vmas and VMAs which points to this anon_vma.
+         *
+         * This counter is used for making decision about reusing anon_vma
+         * instead of forking new one. See comments in function anon_vma_clone.
+         */
+        unsigned degree;
+
+        struct anon_vma *parent;        /* Parent of this anon_vma */
+
+        /*
          * NOTE: the LSB of the rb_root.rb_node is set by
          * mm_take_all_locks() _after_ taking the above lock. So the
          * rb_root must only be read/written after taking the above lock
@@ -188,7 +198,7 @@ int page_referenced(struct page *, int is_locked,
 int try_to_unmap(struct page *, enum ttu_flags flags);
 
 /*
- * Called from mm/filemap_xip.c to unmap empty zero page
+ * Used by uprobes to replace a userspace page safely
  */
 pte_t *__page_check_address(struct page *, struct mm_struct *,
                                 unsigned long, spinlock_t **, int);
@@ -236,7 +246,6 @@ int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
  * arg: passed to rmap_one() and invalid_vma()
  * rmap_one: executed on each vma where page is mapped
  * done: for checking traversing termination condition
- * file_nonlinear: for handling file nonlinear mapping
  * anon_lock: for getting anon_lock by optimized way rather than default
  * invalid_vma: for skipping uninterested vma
  */
@@ -245,7 +254,6 @@ struct rmap_walk_control {
         int (*rmap_one)(struct page *page, struct vm_area_struct *vma,
                                         unsigned long addr, void *arg);
         int (*done)(struct page *page);
-        int (*file_nonlinear)(struct page *, struct address_space *, void *arg);
         struct anon_vma *(*anon_lock)(struct page *page);
         bool (*invalid_vma)(struct vm_area_struct *vma, void *arg);
 };