move page writeback acounting out of macros

page-writeback accounting is presently performed in the page-flags macros.
This is inconsistent and a bit ugly and makes it awkward to implement
per-backing_dev under-writeback page accounting.

So move this accounting down to the callsite(s).

Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 4 insertions, 0 deletions

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 51b3eb6ab445..63512a9ed57e 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -987,6 +987,8 @@ int test_clear_page_writeback(struct page *page)
         } else {
                 ret = TestClearPageWriteback(page);
         }
+        if (ret)
+                dec_zone_page_state(page, NR_WRITEBACK);
         return ret;
 }
 
@@ -1012,6 +1014,8 @@ int test_set_page_writeback(struct page *page)
         } else {
                 ret = TestSetPageWriteback(page);
         }
+        if (!ret)
+                inc_zone_page_state(page, NR_WRITEBACK);
         return ret;
 
 }