CIFS: Add SMB2 support for hardlink operation

Signed-off-by: Pavel Shilovsky <pshilovsky@samba.org>
Signed-off-by: Steve French <smfrench@gmail.com>

fs/cifs/smb2pdu.c

@@ -1709,3 +1709,34 @@ SMB2_rename(const unsigned int xid, struct cifs_tcon *tcon,
 	kfree(data);
 	return rc;
 }
+
+int
+SMB2_set_hardlink(const unsigned int xid, struct cifs_tcon *tcon,
+		  u64 persistent_fid, u64 volatile_fid, __le16 *target_file)
+{
+	struct smb2_file_link_info info;
+	void **data;
+	unsigned int size[2];
+	int rc;
+	int len = (2 * UniStrnlen((wchar_t *)target_file, PATH_MAX));
+
+	data = kmalloc(sizeof(void *) * 2, GFP_KERNEL);
+	if (!data)
+		return -ENOMEM;
+
+	info.ReplaceIfExists = 0; /* 1 = replace existing link with new */
+			      /* 0 = fail if link already exists */
+	info.RootDirectory = 0;  /* MBZ for network ops (why does spec say?) */
+	info.FileNameLength = cpu_to_le32(len);
+
+	data[0] = &info;
+	size[0] = sizeof(struct smb2_file_link_info);
+
+	data[1] = target_file;
+	size[1] = len + 2 /* null */;
+
+	rc = send_set_info(xid, tcon, persistent_fid, volatile_fid,
+			   FILE_LINK_INFORMATION, 2, data, size);
+	kfree(data);
+	return rc;
+}