fs/9p: [fscache] wait for page write in cached mode

We need to call fscache_wait_on_page_write in launder_page
for fscache

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
diff --git a/fs/9p/vfs_addr.c b/fs/9p/vfs_addr.c
index b7f2a8e..637bd70 100644
--- a/fs/9p/vfs_addr.c
+++ b/fs/9p/vfs_addr.c
@@ -151,6 +151,8 @@
 
 static int v9fs_launder_page(struct page *page)
 {
+	struct inode *inode = page->mapping->host;
+	v9fs_fscache_wait_on_page_write(inode, page);
 	return 0;
 }