writeback: don't propagate AOP_WRITEPAGE_ACTIVATE

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>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 4073d53..3348521 100644 (file)
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -849,8 +849,10 @@ 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)) {