[PATCH] add AOP_TRUNCATED_PAGE, prepend AOP_ to WRITEPAGE_ACTIVATE

readpage(), prepare_write(), and commit_write() callers are updated to
understand the special return code AOP_TRUNCATED_PAGE in the style of
writepage() and WRITEPAGE_ACTIVATE.  AOP_TRUNCATED_PAGE tells the caller that
the callee has unlocked the page and that the operation should be tried again
with a new page.  OCFS2 uses this to detect and work around a lock inversion in
its aop methods.  There should be no change in behaviour for methods that don't
return AOP_TRUNCATED_PAGE.

WRITEPAGE_ACTIVATE is also prepended with AOP_ for consistency and they are
made enums so that kerneldoc can be used to document their semantics.

Signed-off-by: Zach Brown <zach.brown@oracle.com>

1 files changed, 0 insertions, 6 deletions

diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 343d883d69c5..64a36ba43b2f 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -60,12 +60,6 @@ struct writeback_control {
 };
 
 /*
- * ->writepage() return values (make these much larger than a pagesize, in
- * case some fs is returning number-of-bytes-written from writepage)
- */
-#define WRITEPAGE_ACTIVATE      0x80000 /* IO was not started: activate page */
-
-/*
  * fs/fs-writeback.c
  */     
 void writeback_inodes(struct writeback_control *wbc);