/*
 * This file is part of the Distributed Network Block Device 3
 *
 * Copyright(c) 2019 Frederic Robra <frederic@robra.org>
 * Parts copyright 2011-2012 Johann Latocha <johann@latocha.de>
 *
 * This file may be licensed under the terms of of the
 * GNU General Public License Version 2 (the ``GPL'').
 *
 * Software distributed under the License is distributed
 * on an ``AS IS'' basis, WITHOUT WARRANTY OF ANY KIND, either
 * express or implied. See the GPL for the specific language
 * governing rights and limitations.
 *
 * You should have received a copy of the GPL along with this
 * program. If not, go to http://www.gnu.org/licenses/gpl.html
 * or write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 *
 */
#ifndef DNBD_H_
#define DNBD_H_

#include <linux/blk-mq.h>
#include <linux/types.h>
#include <linux/refcount.h>
#include <linux/blkdev.h>

#define KERNEL_MODULE
#include "types.h"
#include "serialize.h"


#define NUMBER_CONNECTIONS 4

typedef struct dnbd3_server {
	dnbd3_host_t host;
	uint64_t rtts[4];		// Last four round trip time measurements in microsecond
	uint16_t protocol_version;	// dnbd3 protocol version of this server
	uint8_t failures;			// How many times the server was unreachable
} dnbd3_server;


typedef struct dnbd3_sock {
	struct socket *sock;
	struct mutex lock;
	struct request *pending;
	struct dnbd3_server *server;
	uint32_t heartbeat_count;
	uint8_t panic, discover, panic_count;
//	struct dnbd3_device *container_of;
	struct work_struct keepalive;
	struct timer_list keepalive_timer;
} dnbd3_sock;

typedef struct dnbd3_device {
	int minor;
	struct blk_mq_tag_set tag_set;
	struct list_head list;

	// block
	struct gendisk *disk;

	// sysfs
	struct kobject kobj;

	struct mutex device_lock;

	// network
	dnbd3_sock socks[NUMBER_CONNECTIONS];
	char *imgname;
//	struct socket *sock;
//	struct mutex socket_lock;
//	struct request *pending;
	dnbd3_server initial_server;
//	dnbd3_server_t cur_server, initial_server;
//	uint64_t cur_rtt;
//	serialized_buffer_t payload_buffer;
	dnbd3_server alt_servers[NUMBER_SERVERS]; // array of alt servers
	int new_servers_num;	// number of new alt servers that are waiting to be copied to above array
	dnbd3_server_entry_t new_servers[NUMBER_SERVERS]; // pending new alt servers
//	uint8_t discover, panic, disconnecting, update_available, panic_count;
	uint8_t update_available;
	uint8_t use_server_provided_alts;
	uint16_t rid;
//	uint32_t heartbeat_count;
	uint64_t reported_size;
	// server switch
//	struct socket *better_sock;

	struct work_struct discovery; // if in irq and need to send request
	struct timer_list discovery_timer;

	// process
//	struct task_struct * thread_send;
//	struct task_struct * thread_receive;
//	struct task_struct *thread_discover;
//	struct timer_list hb_timer;
//	wait_queue_head_t process_queue_send;
//	wait_queue_head_t process_queue_receive;
//	wait_queue_head_t process_queue_discover;
//	struct list_head request_queue_send;
//	struct list_head request_queue_receive;

} dnbd3_device;


typedef struct dnbd3_cmd {
	struct dnbd3_device *dnbd3;
	struct mutex lock;
	int index;
	int cookie;
	blk_status_t status;
	unsigned long flags;
	uint32_t cmd_cookie;
} dnbd3_cmd;


#endif /* DNBD_H_ */