From: Nikita Danilov <nikita@clusterfs.com>

Make the Locking document truer.

Signed-off-by: Andrew Morton <akpm@osdl.org>
---

 Documentation/filesystems/Locking |    8 ++++++--
 1 files changed, 6 insertions(+), 2 deletions(-)

diff -puN Documentation/filesystems/Locking~doc-locking-update Documentation/filesystems/Locking
--- 25/Documentation/filesystems/Locking~doc-locking-update	2005-04-26 20:41:20.744590488 -0700
+++ 25-akpm/Documentation/filesystems/Locking	2005-04-26 20:41:20.748589880 -0700
@@ -219,8 +219,12 @@ This may also be done to avoid internal 
 If the filesytem is called for sync then it must wait on any
 in-progress I/O and then start new I/O.
 
-The filesystem should unlock the page synchronously, before returning
-to the caller.
+The filesystem should unlock the page synchronously, before returning to the
+caller, unless ->writepage() returns special WRITEPAGE_ACTIVATE
+value. WRITEPAGE_ACTIVATE means that page cannot really be written out
+currently, and VM should stop calling ->writepage() on this page for some
+time. VM does this by moving page to the head of the active list, hence the
+name.
 
 Unless the filesystem is going to redirty_page_for_writepage(), unlock the page
 and return zero, writepage *must* run set_page_writeback() against the page,
_