From: Andrew Morton <akpm@linux-foundation.org>

This is a writeback-internal marker but we're propagating it all the way back
to userspace!.

Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---


diff -puN mm/page-writeback.c~writeback-dont-propagate-aop_writepage_activate mm/page-writeback.c
--- a/mm/page-writeback.c~writeback-dont-propagate-aop_writepage_activate
+++ a/mm/page-writeback.c
@@ -850,8 +850,10 @@ retry:
 
 			ret = (*writepage)(page, wbc, data);
 
-			if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE))
+			if (unlikely(ret == AOP_WRITEPAGE_ACTIVATE)) {
 				unlock_page(page);
+				ret = 0;
+			}
 			if (ret || (--(wbc->nr_to_write) <= 0))
 				done = 1;
 			if (wbc->nonblocking && bdi_write_congested(bdi)) {
_