expose_nractive_in_mapping.diff

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 9b3c5df75..16fc88b3f 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -416,6 +416,8 @@ struct address_space {
        unsigned long           nrpages;        /* number of total pages */
        /* number of shadow or DAX exceptional entries */
        unsigned long           nrexceptional;
+       unsigned long           nractive;
+       unsigned long           nrinactive;
        pgoff_t                 writeback_index;/* writeback starts here */
        const struct address_space_operations *a_ops;   /* methods */
        unsigned long           flags;          /* error bits */
@@ -553,6 +555,15 @@ static inline void mapping_allow_writable(struct address_space *mapping)
        atomic_inc(&mapping->i_mmap_writable);
 }

+static inline void mapping_update_lru_size(struct address_space *mapping,
+                                          enum lru_list lru,
+                                          long nr)
+{
+       if (lru == LRU_ACTIVE_FILE)
+               mapping->nractive += nr;
+       else if (lru == LRU_INACTIVE_FILE)
+               mapping->nrinactive += nr;
+}
 /*
  * Use sequence counter to get consistent i_size on 32-bit processors.
  */
diff --git a/include/linux/mm_inline.h b/include/linux/mm_inline.h
index 10191c28f..08f05488e 100644
--- a/include/linux/mm_inline.h
+++ b/include/linux/mm_inline.h
@@ -47,22 +47,34 @@ static __always_inline void update_lru_size(struct lruvec *lruvec,
 static __always_inline void add_page_to_lru_list(struct page *page,
                                struct lruvec *lruvec, enum lru_list lru)
 {
-       update_lru_size(lruvec, lru, page_zonenum(page), hpage_nr_pages(page));
+       unsigned long nr = hpage_nr_pages(page);
+
+       if (page->mapping)
+               mapping_update_lru_size(page->mapping, lru, nr);
+       update_lru_size(lruvec, lru, page_zonenum(page), nr);
        list_add(&page->lru, &lruvec->lists[lru]);
 }

 static __always_inline void add_page_to_lru_list_tail(struct page *page,
                                struct lruvec *lruvec, enum lru_list lru)
 {
-       update_lru_size(lruvec, lru, page_zonenum(page), hpage_nr_pages(page));
+       unsigned long nr = hpage_nr_pages(page);
+
+       if (page->mapping)
+               mapping_update_lru_size(page->mapping, lru, nr);
+       update_lru_size(lruvec, lru, page_zonenum(page), nr);
        list_add_tail(&page->lru, &lruvec->lists[lru]);
 }

 static __always_inline void del_page_from_lru_list(struct page *page,
                                struct lruvec *lruvec, enum lru_list lru)
 {
+       unsigned long nr = hpage_nr_pages(page);
+
+       if (page->mapping)
+               mapping_update_lru_size(page->mapping, lru, -nr);
        list_del(&page->lru);
-       update_lru_size(lruvec, lru, page_zonenum(page), -hpage_nr_pages(page));
+       update_lru_size(lruvec, lru, page_zonenum(page), -nr);
 }
 }

 /**
diff --git a/mm/vmscan.c b/mm/vmscan.c
index 8e36afbb3..17e006d07 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -1689,6 +1689,8 @@ static unsigned long isolate_lru_pages(unsigned long nr_to_scan,
                        nr_taken += nr_pages;
                        nr_zone_taken[page_zonenum(page)] += nr_pages;
                        list_move(&page->lru, dst);
+                       if (page->mapping)
+                               mapping_update_lru_size(page->mapping, lru, -nr_pages);
                        break;

                case -EBUSY:
@@ -2036,6 +2038,8 @@ static unsigned move_active_pages_to_lru(struct lruvec *lruvec,
                SetPageLRU(page);

                nr_pages = hpage_nr_pages(page);
+               if (page->mapping)
+                       mapping_update_lru_size(page->mapping, lru, nr_pages);
                update_lru_size(lruvec, lru, page_zonenum(page), nr_pages);
                list_move(&page->lru, &lruvec->lists[lru]);