1 files changed, 13 insertions, 17 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 7262aacea8a2..e3bccac1f025 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -836,7 +836,8 @@ void tag_pages_for_writeback(struct address_space *mapping,
                 spin_unlock_irq(&mapping->tree_lock);
                 WARN_ON_ONCE(tagged > WRITEBACK_TAG_BATCH);
                 cond_resched();
-        } while (tagged >= WRITEBACK_TAG_BATCH);
+                /* We check 'start' to handle wrapping when end == ~0UL */
+        } while (tagged >= WRITEBACK_TAG_BATCH && start);
 }
 EXPORT_SYMBOL(tag_pages_for_writeback);
 
@@ -984,22 +985,16 @@ continue_unlock:
                                 }
                         }
 
-                        if (wbc->nr_to_write > 0) {
-                                if (--wbc->nr_to_write == 0 &&
-                                    wbc->sync_mode == WB_SYNC_NONE) {
-                                        /*
-                                         * We stop writing back only if we are
-                                         * not doing integrity sync. In case of
-                                         * integrity sync we have to keep going
-                                         * because someone may be concurrently
-                                         * dirtying pages, and we might have
-                                         * synced a lot of newly appeared dirty
-                                         * pages, but have not synced all of the
-                                         * old dirty pages.
-                                         */
-                                        done = 1;
-                                        break;
-                                }
+                        /*
+                         * We stop writing back only if we are not doing
+                         * integrity sync. In case of integrity sync we have to
+                         * keep going until we have written all the pages
+                         * we tagged for writeback prior to entering this loop.
+                         */
+                        if (--wbc->nr_to_write <= 0 &&
+                            wbc->sync_mode == WB_SYNC_NONE) {
+                                done = 1;
+                                break;
                         }
                 }
                 pagevec_release(&pvec);
@@ -1131,6 +1126,7 @@ void account_page_dirtied(struct page *page, struct address_space *mapping)
                 task_io_account_write(PAGE_CACHE_SIZE);
         }
 }
+EXPORT_SYMBOL(account_page_dirtied);
 
 /*
  * For address_spaces which do not use buffers.  Just tag the page as dirty in