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/link.c b/fs/cifs/link.c
index ce417a9..1a6a388 100644
--- a/fs/cifs/link.c
+++ b/fs/cifs/link.c
@@ -184,6 +184,7 @@
 	__u16 netfid = 0;
 	u8 *buf;
 	unsigned int bytes_written = 0;
+	struct cifs_io_parms io_parms;
 
 	buf = kmalloc(CIFS_MF_SYMLINK_FILE_SIZE, GFP_KERNEL);
 	if (!buf)
@@ -203,10 +204,13 @@
 		return rc;
 	}
 
-	rc = CIFSSMBWrite(xid, tcon, netfid,
-			  CIFS_MF_SYMLINK_FILE_SIZE /* length */,
-			  0 /* offset */,
-			  &bytes_written, buf, NULL, 0);
+	io_parms.netfid = netfid;
+	io_parms.pid = current->tgid;
+	io_parms.tcon = tcon;
+	io_parms.offset = 0;
+	io_parms.length = CIFS_MF_SYMLINK_FILE_SIZE;
+
+	rc = CIFSSMBWrite(xid, &io_parms, &bytes_written, buf, NULL, 0);
 	CIFSSMBClose(xid, tcon, netfid);
 	kfree(buf);
 	if (rc != 0)