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);
        }
 
 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);
 
        return 0;
 }
 
+/*
+ * 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.
                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);
                }