FS: Use stable writes when not doing a bulk flush

If we're only doing a single write, and there are no other unstable
writes being queued up, we might want to just flip to using a stable
write RPC call.

Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/pagelist.c b/fs/nfs/pagelist.c
index 23e7944..fd85618 100644
--- a/fs/nfs/pagelist.c
+++ b/fs/nfs/pagelist.c
@@ -223,6 +223,7 @@
 	desc->pg_count = 0;
 	desc->pg_bsize = bsize;
 	desc->pg_base = 0;
+	desc->pg_moreio = 0;
 	desc->pg_inode = inode;
 	desc->pg_doio = doio;
 	desc->pg_ioflags = io_flags;
@@ -335,9 +336,11 @@
 			   struct nfs_page *req)
 {
 	while (!nfs_pageio_do_add_request(desc, req)) {
+		desc->pg_moreio = 1;
 		nfs_pageio_doio(desc);
 		if (desc->pg_error < 0)
 			return 0;
+		desc->pg_moreio = 0;
 	}
 	return 1;
 }