CIFS: Use pid saved from cifsFileInfo in writepages and set_file_size

We need it to make them work with mandatory locking style because
we can fail in a situation like when kernel need to flush dirty pages
and there is a lock held by a process who opened file.

Signed-off-by: Pavel Shilovsky <piastry@etersoft.ru>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h
index fd877c1..30699d9 100644
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -455,6 +455,14 @@
 	struct work_struct oplock_break; /* work for oplock breaks */
 };
 
+struct cifs_io_parms {
+	__u16 netfid;
+	__u32 pid;
+	__u64 offset;
+	unsigned int length;
+	struct cifsTconInfo *tcon;
+};
+
 /*
  * Take a reference on the file private data. Must be called with
  * cifs_file_list_lock held.