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/*
* kernel/devices.c
*/
#include "dnbd2.h"
#include "core.h"
#include "fops.h"
#include "sysfs.h"
#include "devices.h"
#include "servers.h"
#define TO_PERCENT 50
#define TO_JIFFIES 10
/*
* Activate the request-processing mechanism for @dev: dnbd2_requeue
* (timer) and dnbd2_tx_loop (thread). dnbd2_rx_loop is started
* afterwards by add_server on a per-server basis.
*/
int start_device(dnbd2_device_t *dev)
{
/* Start requeue timer. */
init_timer(&dev->requeue_timer);
dev->requeue_timer.data = (unsigned long)dev;
dev->requeue_timer.function = dnbd2_requeue_timer;
dev->requeue_timer.expires = jiffies + REQUEUE_INTERVAL;
add_timer(&dev->requeue_timer);
/* Start heartbeat timer. */
init_timer(&dev->hb_timer);
dev->hb_timer.data = (unsigned long)dev;
dev->hb_timer.function = dnbd2_hb_timer;
dev->hb_timer.expires = jiffies + HB_NORMAL_INTERVAL;
add_timer(&dev->hb_timer);
/* Start takeover timer. */
init_timer(&dev->to_timer);
dev->to_timer.data = (unsigned long)dev;
dev->to_timer.function = dnbd2_to_timer;
dev->to_timer.expires = jiffies + TO_INTERVAL;
add_timer(&dev->to_timer);
/* Start sending thread. */
dev->tx_signal = 0;
dev->tx_id = kernel_thread(dnbd2_tx_loop, dev, CLONE_KERNEL);
if (dev->tx_id < 0) {
del_timer(&dev->hb_timer);
del_timer(&dev->to_timer);
del_timer(&dev->requeue_timer);
return -1;
}
wait_for_completion(&dev->tx_start);
return 0;
}
/*
* Deactivate the request-processing mechanism for @dev. All
* dnbd2_rx_loop threads must be stopped beforehand by del_server.
*/
void stop_device(dnbd2_device_t *dev)
{
struct list_head *cur, *next;
struct request *req;
/* Stop heartbeat timer. */
del_timer(&dev->hb_timer);
/* Stop takeover timer. */
del_timer(&dev->to_timer);
/* Stop request processing. */
del_timer(&dev->requeue_timer);
dev->tx_signal = 1;
#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,27)
kill_proc_info(SIGKILL, 1, dev->tx_id);
#else
kill_proc(dev->tx_id, SIGKILL, 1);
#endif
wait_for_completion(&dev->tx_stop);
/* Empty pending-queue. */
list_for_each_safe(cur, next, &dev->pending_queue) {
req = blkdev_entry_to_request(cur);
list_del_init(&req->queuelist);
dnbd2_end_request(req, 0);
}
/* Empty send-queue. */
list_for_each_safe(cur, next, &dev->send_queue) {
req = blkdev_entry_to_request(cur);
list_del_init(&req->queuelist);
dnbd2_end_request(req, 0);
}
}
int add_device(dnbd2_device_t *dev, int minor)
{
struct request_queue *queue;
struct srv_info *srv_info;
struct gendisk *disk;
int i;
/*
* Prepare dnbd2_device_t. Please use the
* same order as in dnbd2.h.
*/
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20))
INIT_WORK(&dev->work, NULL, NULL);
#else
INIT_WORK(&dev->work, NULL);
#endif
spin_lock_init(&dev->kmap_lock);
for (i=0 ; i<POOL_SIZE ; i++)
dev->info_pool[i].cnt = -1;
dev->emergency = 0;
dev->running = 0;
dev->vid = 0;
dev->rid = 0;
atomic_set(&dev->refcnt, 0);
init_MUTEX(&dev->config_mutex);
spin_lock_init(&dev->blk_lock);
init_waitqueue_head(&dev->sender_wq);
spin_lock_init(&dev->send_queue_lock);
INIT_LIST_HEAD(&dev->send_queue);
dev->pending_reqs = 0;
spin_lock_init(&dev->pending_queue_lock);
INIT_LIST_HEAD(&dev->pending_queue);
dev->hb_interval = HB_NORMAL_INTERVAL;
init_completion(&dev->tx_start);
init_completion(&dev->tx_stop);
init_MUTEX(&dev->servers_mutex);
for_each_server(i) {
dev->emerg_list[i].ip = 0;
dev->emerg_list[i].port = 0;
srv_info = &dev->servers[i];
memset(srv_info, 0, sizeof(struct srv_info));
init_completion(&srv_info->rx_start);
init_completion(&srv_info->rx_stop);
init_waitqueue_head(&srv_info->wq);
#if (LINUX_VERSION_CODE < KERNEL_VERSION(2,6,20))
INIT_WORK(&srv_info->work, NULL, NULL);
#else
INIT_WORK(&srv_info->work, NULL);
#endif
/* Change in /<linuxheaders>/include/linux/workqueue.h */
srv_info->dev = dev;
}
dev->active_server = NULL;
dev->to_percent = TO_PERCENT;
dev->to_jiffies = TO_JIFFIES;
/* Prepare struct gendisk. */
disk = alloc_disk(1);
if (!disk) {
p("Could not alloc gendisk.\n");
goto out_nodisk;
}
dev->disk = disk;
disk->private_data = dev;
disk->major = dnbd2_major;
disk->first_minor = minor;
disk->fops = &dnbd2_fops;
sprintf(disk->disk_name, "vnbd%d", minor);
set_capacity(disk, 0);
set_disk_ro(disk, 1);
/* Prepare struct request_queue. */
queue = blk_init_queue(dnbd2_request, &dev->blk_lock);
if (!queue) {
p("Could not alloc request queue.\n");
goto out_noqueue;
}
/*
* Tell the block layer to give us only requests consisting of
* one segment of DNBD2_BLOCK_SIZE bytes.
*/
blk_queue_max_sectors(queue, DNBD2_BLOCK_SIZE/SECTOR_SIZE);
blk_queue_max_segment_size(queue, DNBD2_BLOCK_SIZE);
blk_queue_hardsect_size(queue, DNBD2_BLOCK_SIZE);
blk_queue_max_phys_segments(queue, 1);
blk_queue_max_hw_segments(queue, 1);
disk->queue = queue;
add_disk(disk);
if (start_sysfs(dev))
goto out_nosysfs;
if (start_device(dev))
goto out_nostart;
return 0;
out_nostart:
stop_sysfs(dev);
out_nosysfs:
blk_cleanup_queue(queue);
out_noqueue:
del_gendisk(disk);
put_disk(disk);
out_nodisk:
return -ENOMEM;
}
void del_device(dnbd2_device_t *dev)
{
int i;
for_each_server(i)
del_server(&dev->servers[i]);
stop_device(dev);
stop_sysfs(dev);
blk_cleanup_queue(dev->disk->queue);
del_gendisk(dev->disk);
put_disk(dev->disk);
}
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