/* SPDX-License-Identifier: GPL-2.0 */
/*
* This file is part of the Distributed Network Block Device 3
*
* Copyright(c) 2011-2012 Johann Latocha <johann@latocha.de>
*
* This file may be licensed under the terms 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 <dnbd3/config/client.h>
#include <linux/version.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/mutex.h>
#include <net/sock.h>
#include <dnbd3/config.h>
#include <dnbd3/types.h>
#include <dnbd3/shared/serialize.h>
#include <linux/blk-mq.h>
#if defined(RHEL_RELEASE_CODE) && defined(RHEL_RELEASE_VERSION)
#define RHEL_CHECK_VERSION(CONDITION) (CONDITION)
#else
#define RHEL_CHECK_VERSION(CONDITION) (0)
#endif
extern int major;
typedef struct {
unsigned long rtts[DISCOVER_HISTORY_SIZE]; // Last X round trip time measurements in µs
uint16_t protocol_version; // dnbd3 protocol version of this server
uint8_t failures; // How many times the server was unreachable
uint8_t best_count; // Number of times server measured best
struct sockaddr_storage host; // Address of server
} dnbd3_alt_server_t;
typedef struct {
// block
int index;
struct gendisk *disk;
struct blk_mq_tag_set tag_set;
struct request_queue *queue;
spinlock_t blk_lock;
// sysfs
struct kobject kobj;
char *imgname;
uint16_t rid;
struct socket *sock;
struct { // use blk_lock
unsigned long rtt;
struct sockaddr_storage host;
uint16_t protocol_version;
} cur_server;
serialized_buffer_t payload_buffer;
struct mutex alt_servers_lock;
dnbd3_alt_server_t alt_servers[NUMBER_SERVERS];
bool use_server_provided_alts;
bool panic;
u8 panic_count;
bool update_available;
atomic_t connection_lock;
// Size if image/device - this is 0 if the device is not in use,
// otherwise this is also the value we expect from alt servers.
uint64_t reported_size;
struct delayed_work keepalive_work;
// sending
struct workqueue_struct *send_wq;
spinlock_t send_queue_lock;
struct list_head send_queue;
struct mutex send_mutex;
struct work_struct send_work;
// receiving
struct workqueue_struct *recv_wq;
spinlock_t recv_queue_lock;
struct list_head recv_queue;
struct mutex recv_mutex;
struct work_struct recv_work;
// discover
atomic_t discover_running;
struct delayed_work discover_work;
u32 discover_interval;
u32 discover_count;
} dnbd3_device_t;
struct dnbd3_cmd {
u64 handle;
};
extern inline struct device *dnbd3_device_to_dev(dnbd3_device_t *dev);
extern inline int is_same_server(const struct sockaddr_storage *const x, const struct sockaddr_storage *const y);
extern int dnbd3_host_to_sockaddr(const dnbd3_host_t *host, struct sockaddr_storage *dest);
extern dnbd3_alt_server_t *get_existing_alt_from_host(const dnbd3_host_t *const host, dnbd3_device_t *const dev);
extern dnbd3_alt_server_t *get_existing_alt_from_addr(const struct sockaddr_storage *const addr,
dnbd3_device_t *const dev);
extern int dnbd3_add_server(dnbd3_device_t *dev, dnbd3_host_t *host);
extern int dnbd3_rem_server(dnbd3_device_t *dev, dnbd3_host_t *host);
#define dnbd3_flag_get(x) (atomic_cmpxchg(&(x), 0, 1) == 0)
#define dnbd3_flag_reset(x) atomic_set(&(x), 0)
#define dnbd3_flag_taken(x) (atomic_read(&(x)) != 0)
/*
* shims for making older kernels look like the current one, if possible, to avoid too
* much inline #ifdef which makes code harder to read.
*/
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 18, 0)
#define BLK_EH_DONE BLK_EH_NOT_HANDLED
#endif
#if LINUX_VERSION_CODE < KERNEL_VERSION(4, 13, 0)
#define blk_status_t int
#define BLK_STS_OK 0
#define BLK_STS_IOERR (-EIO)
#define BLK_STS_TIMEOUT (-ETIME)
#define BLK_STS_NOTSUPP (-ENOTSUPP)
#endif
#endif /* DNBD_H_ */
