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/*
* kernel/dnbd2.h
*/
#include <linux/version.h>
#include <linux/workqueue.h>
#include <linux/completion.h>
#include <linux/blkdev.h>
#include <linux/types.h>
#include <linux/wait.h>
#include <linux/inet.h>
#include <linux/in.h>
#include <linux/version.h>
#include <linux/kthread.h>
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,26)
#include <linux/semaphore.h>
#else
#include <asm/semaphore.h>
#endif
#include <net/sock.h>
#include "../include/dnbd2.h"
#define LOG KERN_NOTICE "dnbd2: "
#define p(msg) printk(LOG msg);
#define SECTOR_SIZE 512
#define for_each_server(i) for (i=0 ; i<ALT_SERVERS_MAX ; i++)
/* max number of requests the driver can handle at once. */
#define POOL_SIZE 128
/* precision of sector_t for pretty-printing */
#ifdef CONFIG_LBD
# define SECT_PRECISION "%llu"
#else
# define SECT_PRECISION "%lu"
#endif
typedef struct dnbd2_device dnbd2_device_t;
/*
* We stick this structure to each request before enqueing it into the
* send-queue. It gives information on how to treat the request.
*/
struct req_info {
uint16_t time; /* enqueue time */
uint16_t cmd; /* command (CMD_XXX) */
int cnt; /* send count */
struct srv_info *dst; /* destination server */
struct srv_info *last_dst; /* last destination server */
};
/*
* Information about a server with which we communicate.
*/
struct srv_info {
dnbd2_device_t *dev;
struct kobject kobj;
struct work_struct work;
struct socket *sock; /* NULL iff server not configured */
uint32_t ip; /* network byte order */
uint32_t port; /* network byte order */
uint16_t min, max; /* min and max RTTs */
unsigned long srtt; /* SRTT (SRTT_SHIFT left-shifted) */
sector_t capacity; /* used when a CMD_GET_SIZE reply arrives */
wait_queue_head_t wq; /* used when a CMD_GET_SIZE reply arrives */
long rx_id; /* pid of dnbd2_rx_loop */
struct completion rx_start; /* dnbd2_rx_loop has started */
struct completion rx_stop; /* dnbd2_rx_loop has stopped */
struct task_struct *dnbd_thread_task;
unsigned long retries; /* number of requests retried */
unsigned long last_reply; /* time of last reply */
};
struct dnbd2_device {
struct work_struct work;
struct kobject kobj;
spinlock_t kmap_lock;
struct req_info info_pool[POOL_SIZE];
int running; /* device is running and capacity != 0 */
int emergency; /* device has lost contact to all servers */
uint16_t vid, rid; /* Volume-ID and Release-ID */
atomic_t refcnt; /* for open/release, see fops.c */
struct semaphore config_mutex; /* for open/release and sysfs-fops */
struct gendisk *disk; /* interface to the block layer */
spinlock_t blk_lock; /* queue-lock, shared with the block layer */
wait_queue_head_t sender_wq; /* wait-queue to notify dnbd2_tx_loop */
spinlock_t send_queue_lock;
struct list_head send_queue;
struct task_struct *dnbd_device_thread_task;
unsigned long pending_reqs; /* number of block requests pending */
spinlock_t pending_queue_lock;
struct list_head pending_queue;
struct timer_list requeue_timer; /* requeue timer */
struct timer_list to_timer; /* takeover timer */
struct timer_list hb_timer; /* heartbeat timer */
unsigned long hb_interval; /* HB_NORMAL_ or HB_EMERG_INTERVAL */
int tx_id; /* pid of dnbd2_tx_loop */
struct completion tx_start; /* dnbd2_tx_loop has started */
struct completion tx_stop; /* dnbd2_tx_loop has stopped */
int tx_signal; /* tells dnbd2_tx_loop to stop */
struct semaphore servers_mutex;
struct srv_info servers[ALT_SERVERS_MAX];
dnbd2_server_t emerg_list[ALT_SERVERS_MAX]; /* last servers known */
struct srv_info *active_server;
int to_percent; /* percent threshold for takeover (relativ) */
uint16_t to_jiffies; /* jiffies threshold for takeover (absolute) */
};
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