identify multipage ->writepages() calls

 NFS needs to be able to distinguish between single-page ->writepage() calls and
 multipage ->writepages() calls.

 For the single-page writepage calls NFS can kick off the I/O within the
 context of ->writepage().

 For multipage ->writepages calls, nfs_writepage() will leave the I/O pending
 and nfs_writepages() will kick off the I/O when it all has been queued up
 within NFS.

 Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
 Signed-off-by: Andrew Morton <akpm@osdl.org>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 64a36ba43b2f..b096159086e8 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -53,10 +53,11 @@ struct writeback_control {
         loff_t start;
         loff_t end;
 
-        unsigned nonblocking:1;                 /* Don't get stuck on request queues */
-        unsigned encountered_congestion:1;      /* An output: a queue is full */
-        unsigned for_kupdate:1;                 /* A kupdate writeback */
-        unsigned for_reclaim:1;                 /* Invoked from the page allocator */
+        unsigned nonblocking:1;         /* Don't get stuck on request queues */
+        unsigned encountered_congestion:1; /* An output: a queue is full */
+        unsigned for_kupdate:1;         /* A kupdate writeback */
+        unsigned for_reclaim:1;         /* Invoked from the page allocator */
+        unsigned for_writepages:1;      /* This is a writepages() call */
 };
 
 /*