1 files changed, 19 insertions, 12 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index e3bccac1f025..b840afa89761 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -415,14 +415,8 @@ void global_dirty_limits(unsigned long *pbackground, unsigned long *pdirty)
 
         if (vm_dirty_bytes)
                 dirty = DIV_ROUND_UP(vm_dirty_bytes, PAGE_SIZE);
-        else {
-                int dirty_ratio;
-
-                dirty_ratio = vm_dirty_ratio;
-                if (dirty_ratio < 5)
-                        dirty_ratio = 5;
-                dirty = (dirty_ratio * available_memory) / 100;
-        }
+        else
+                dirty = (vm_dirty_ratio * available_memory) / 100;
 
         if (dirty_background_bytes)
                 background = DIV_ROUND_UP(dirty_background_bytes, PAGE_SIZE);
@@ -510,7 +504,7 @@ static void balance_dirty_pages(struct address_space *mapping,
                  * catch-up. This avoids (excessively) small writeouts
                  * when the bdi limits are ramping up.
                  */
-                if (nr_reclaimable + nr_writeback <
+                if (nr_reclaimable + nr_writeback <=
                                 (background_thresh + dirty_thresh) / 2)
                         break;
 
@@ -542,8 +536,8 @@ static void balance_dirty_pages(struct address_space *mapping,
                  * the last resort safeguard.
                  */
                 dirty_exceeded =
-                        (bdi_nr_reclaimable + bdi_nr_writeback >= bdi_thresh)
-                        || (nr_reclaimable + nr_writeback >= dirty_thresh);
+                        (bdi_nr_reclaimable + bdi_nr_writeback > bdi_thresh)
+                        || (nr_reclaimable + nr_writeback > dirty_thresh);
 
                 if (!dirty_exceeded)
                         break;
@@ -1121,6 +1115,7 @@ 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_zone_page_state(page, NR_DIRTIED);
                 __inc_bdi_stat(mapping->backing_dev_info, BDI_RECLAIMABLE);
                 task_dirty_inc(current);
                 task_io_account_write(PAGE_CACHE_SIZE);
@@ -1129,6 +1124,18 @@ void account_page_dirtied(struct page *page, struct address_space *mapping)
 EXPORT_SYMBOL(account_page_dirtied);
 
 /*
+ * Helper function for set_page_writeback family.
+ * NOTE: Unlike account_page_dirtied this does not rely on being atomic
+ * wrt interrupts.
+ */
+void account_page_writeback(struct page *page)
+{
+        inc_zone_page_state(page, NR_WRITEBACK);
+        inc_zone_page_state(page, NR_WRITTEN);
+}
+EXPORT_SYMBOL(account_page_writeback);
+
+/*
  * For address_spaces which do not use buffers.  Just tag the page as dirty in
  * its radix tree.
  *
@@ -1366,7 +1373,7 @@ int test_set_page_writeback(struct page *page)
                 ret = TestSetPageWriteback(page);
         }
         if (!ret)
-                inc_zone_page_state(page, NR_WRITEBACK);
+                account_page_writeback(page);
         return ret;
 
 }