3 files changed, 17 insertions, 15 deletions

diff --git a/fs/buffer.c b/fs/buffer.c
index a2fd743d97cb..73abe6d8218c 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -621,14 +621,7 @@ static void __set_page_dirty(struct page *page,
         spin_lock_irq(&mapping->tree_lock);
         if (page->mapping) {    /* Race with truncate? */
                 WARN_ON_ONCE(warn && !PageUptodate(page));
-
-                if (mapping_cap_account_dirty(mapping)) {
-                        __inc_zone_page_state(page, NR_FILE_DIRTY);
-                        __inc_bdi_stat(mapping->backing_dev_info,
-                                        BDI_RECLAIMABLE);
-                        task_dirty_inc(current);
-                        task_io_account_write(PAGE_CACHE_SIZE);
-                }
+                account_page_dirtied(page, mapping);
                 radix_tree_tag_set(&mapping->page_tree,
                                 page_index(page), PAGECACHE_TAG_DIRTY);
         }
diff --git a/include/linux/mm.h b/include/linux/mm.h
index b1ea37fc7a24..2223f8dfa568 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -834,6 +834,7 @@ int __set_page_dirty_nobuffers(struct page *page);
 int __set_page_dirty_no_writeback(struct page *page);
 int redirty_page_for_writepage(struct writeback_control *wbc,
                                 struct page *page);
+void account_page_dirtied(struct page *page, struct address_space *mapping);
 int set_page_dirty(struct page *page);
 int set_page_dirty_lock(struct page *page);
 int clear_page_dirty_for_io(struct page *page);
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 40ca7cdb653e..6aa92b03c747 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -1198,6 +1198,20 @@ int __set_page_dirty_no_writeback(struct page *page)
 }
 
 /*
+ * Helper function for set_page_dirty family.
+ * NOTE: This relies on being atomic wrt interrupts.
+ */
+void account_page_dirtied(struct page *page, struct address_space *mapping)
+{
+        if (mapping_cap_account_dirty(mapping)) {
+                __inc_zone_page_state(page, NR_FILE_DIRTY);
+                __inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
+                task_dirty_inc(current);
+                task_io_account_write(PAGE_CACHE_SIZE);
+        }
+}
+
+/*
  * For address_spaces which do not use buffers.  Just tag the page as dirty in
  * its radix tree.
  *
@@ -1226,13 +1240,7 @@ int __set_page_dirty_nobuffers(struct page *page)
                 if (mapping2) { /* Race with truncate? */
                         BUG_ON(mapping2 != mapping);
                         WARN_ON_ONCE(!PagePrivate(page) && !PageUptodate(page));
-                        if (mapping_cap_account_dirty(mapping)) {
-                                __inc_zone_page_state(page, NR_FILE_DIRTY);
-                                __inc_bdi_stat(mapping->backing_dev_info,
-                                                BDI_RECLAIMABLE);
-                                task_dirty_inc(current);
-                                task_io_account_write(PAGE_CACHE_SIZE);
-                        }
+                        account_page_dirtied(page, mapping);
                         radix_tree_tag_set(&mapping->page_tree,
                                 page_index(page), PAGECACHE_TAG_DIRTY);
                 }