From e46c7287b1c27683a8e30ca825fb98e2b97f1099 Mon Sep 17 00:00:00 2001 From: Josef Bacik Date: Thu, 6 Apr 2017 17:02:00 -0400 Subject: nbd: add a basic netlink interface The existing ioctl interface for configuring NBD devices is a bit cumbersome and hard to extend. The other problem is we leave a userspace app sitting in it's syscall until the device disconnects, which is less than ideal. This patch introduces a netlink interface for adding and disconnecting nbd devices. This has the benefits of being easily extendable without breaking older userspace applications, and allows us to configure a nbd device without leaving a userspace app sitting waiting for the device to disconnect. With this interface we also gain the ability to configure more devices than are preallocated at insmod time. We also have gained the ability to not specify a particular device and be provided one for us so that userspace doesn't need to find a free device to configure. Signed-off-by: Josef Bacik Signed-off-by: Jens Axboe --- include/uapi/linux/nbd-netlink.h | 69 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 69 insertions(+) create mode 100644 include/uapi/linux/nbd-netlink.h (limited to 'include/uapi') diff --git a/include/uapi/linux/nbd-netlink.h b/include/uapi/linux/nbd-netlink.h new file mode 100644 index 000000000000..fd0f4e45f03e --- /dev/null +++ b/include/uapi/linux/nbd-netlink.h @@ -0,0 +1,69 @@ +/* + * Copyright (C) 2017 Facebook. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ +#ifndef _UAPILINUX_NBD_NETLINK_H +#define _UAPILINUX_NBD_NETLINK_H + +#define NBD_GENL_FAMILY_NAME "nbd" +#define NBD_GENL_VERSION 0x1 + +/* Configuration policy attributes, used for CONNECT */ +enum { + NBD_ATTR_UNSPEC, + NBD_ATTR_INDEX, + NBD_ATTR_SIZE_BYTES, + NBD_ATTR_BLOCK_SIZE_BYTES, + NBD_ATTR_TIMEOUT, + NBD_ATTR_SERVER_FLAGS, + NBD_ATTR_CLIENT_FLAGS, + NBD_ATTR_SOCKETS, + __NBD_ATTR_MAX, +}; +#define NBD_ATTR_MAX (__NBD_ATTR_MAX - 1) + +/* + * This is the format for multiple sockets with NBD_ATTR_SOCKETS + * + * [NBD_ATTR_SOCKETS] + * [NBD_SOCK_ITEM] + * [NBD_SOCK_FD] + * [NBD_SOCK_ITEM] + * [NBD_SOCK_FD] + */ +enum { + NBD_SOCK_ITEM_UNSPEC, + NBD_SOCK_ITEM, + __NBD_SOCK_ITEM_MAX, +}; +#define NBD_SOCK_ITEM_MAX (__NBD_SOCK_ITEM_MAX - 1) + +enum { + NBD_SOCK_UNSPEC, + NBD_SOCK_FD, + __NBD_SOCK_MAX, +}; +#define NBD_SOCK_MAX (__NBD_SOCK_MAX - 1) + +enum { + NBD_CMD_UNSPEC, + NBD_CMD_CONNECT, + NBD_CMD_DISCONNECT, + __NBD_CMD_MAX, +}; +#define NBD_CMD_MAX (__NBD_CMD_MAX - 1) + +#endif /* _UAPILINUX_NBD_NETLINK_H */ -- cgit v1.2.3