diff options
Diffstat (limited to 'kernel/dnbd2.h')
| -rw-r--r-- | kernel/dnbd2.h | 118 |
1 files changed, 118 insertions, 0 deletions
diff --git a/kernel/dnbd2.h b/kernel/dnbd2.h new file mode 100644 index 0000000..cf693d9 --- /dev/null +++ b/kernel/dnbd2.h @@ -0,0 +1,118 @@ +/* + * 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 <asm/semaphore.h> +#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 */ + + 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; + + 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) */ +}; |