/*
* 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 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.
*
*/
#include "blk.h"
#include "net.h"
#include "sysfs.h"
#include <linux/pagemap.h>
int dnbd3_blk_add_device(dnbd3_device_t *dev, int minor)
{
struct gendisk *disk;
struct request_queue *blk_queue;
init_waitqueue_head(&dev->process_queue_send);
init_waitqueue_head(&dev->process_queue_receive);
init_waitqueue_head(&dev->process_queue_discover);
INIT_LIST_HEAD(&dev->request_queue_send);
INIT_LIST_HEAD(&dev->request_queue_receive);
memset(&dev->cur_server, 0, sizeof(dnbd3_server_t));
dev->better_sock = NULL;
dev->imgname = NULL;
dev->rid = 0;
dev->update_available = 0;
dev->alt_servers_num = 0;
memset(dev->alt_servers, 0, sizeof(dnbd3_server_t)*NUMBER_SERVERS);
dev->thread_send = NULL;
dev->thread_receive = NULL;
dev->thread_discover = NULL;
dev->discover = 0;
dev->panic = 0;
dev->panic_count = 0;
dev->reported_size = 0;
if (!(disk = alloc_disk(1)))
{
printk("ERROR: dnbd3 alloc_disk failed.\n");
return -EIO;
}
disk->major = major;
disk->first_minor = minor;
sprintf(disk->disk_name, "dnbd%d", minor);
set_capacity(disk, 0);
set_disk_ro(disk, 1);
disk->fops = &dnbd3_blk_ops;
spin_lock_init(&dev->blk_lock);
if ((blk_queue = blk_init_queue(&dnbd3_blk_request, &dev->blk_lock)) == NULL)
{
printk("ERROR: dnbd3 blk_init_queue failed.\n");
return -EIO;
}
blk_queue_logical_block_size(blk_queue, DNBD3_BLOCK_SIZE);
blk_queue_physical_block_size(blk_queue, DNBD3_BLOCK_SIZE);
disk->queue = blk_queue;
disk->private_data = dev;
queue_flag_set_unlocked(QUEUE_FLAG_NONROT, disk->queue);
dev->disk = disk;
add_disk(disk);
dnbd3_sysfs_init(dev);
return 0;
}
int dnbd3_blk_del_device(dnbd3_device_t *dev)
{
dnbd3_sysfs_exit(dev);
dnbd3_net_disconnect(dev);
del_gendisk(dev->disk);
put_disk(dev->disk);
blk_cleanup_queue(dev->disk->queue);
return 0;
}
struct block_device_operations dnbd3_blk_ops =
{ .owner = THIS_MODULE, .ioctl = dnbd3_blk_ioctl, };
int dnbd3_blk_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
{
int result = 0;
dnbd3_device_t *dev = bdev->bd_disk->private_data;
struct request_queue *blk_queue = dev->disk->queue;
char *imgname = NULL;
dnbd3_ioctl_t *msg = kmalloc(sizeof(dnbd3_ioctl_t), GFP_KERNEL);
if (msg == NULL) return -ENOMEM;
copy_from_user((char *)msg, (char *)arg, 2);
if (msg->len != sizeof(dnbd3_ioctl_t))
{
result = -ENOEXEC;
goto cleanup_return;
}
copy_from_user((char *)msg, (char *)arg, sizeof(dnbd3_ioctl_t));
if (msg->imgname != NULL && msg->imgnamelen > 0)
{
imgname = kmalloc(msg->imgnamelen + 1, GFP_KERNEL);
if (imgname == NULL)
{
result = -ENOMEM;
goto cleanup_return;
}
copy_from_user(imgname, msg->imgname, msg->imgnamelen);
imgname[msg->imgnamelen] = '\0';
//printk("IOCTL Image name of len %d is %s\n", (int)msg->imgnamelen, imgname);
}
switch (cmd)
{
case IOCTL_OPEN:
if (dev->imgname != NULL)
{
result = -EBUSY;
}
else if (imgname == NULL)
{
result = -EINVAL;
}
else
{
memcpy(dev->cur_server.hostaddr, msg->addr, 16);
dev->cur_server.port = msg->port;
dev->cur_server.hostaddrtype = msg->addrtype;
dev->imgname = imgname;
dev->rid = msg->rid;
blk_queue->backing_dev_info.ra_pages = (msg->read_ahead_kb * 1024) / PAGE_CACHE_SIZE;
if (dnbd3_net_connect(dev) == 0)
{
result = 0;
imgname = NULL; // Prevent kfree at the end
}
else
{
result = -ENOENT;
dev->imgname = NULL;
}
}
break;
case IOCTL_CLOSE:
set_capacity(dev->disk, 0);
result = dnbd3_net_disconnect(dev);
dnbd3_blk_fail_all_requests(dev);
if (dev->imgname)
{
kfree(dev->imgname);
dev->imgname = NULL;
}
break;
case IOCTL_SWITCH:
dnbd3_net_disconnect(dev);
memcpy(dev->cur_server.hostaddr, msg->addr, 16);
dev->cur_server.port = msg->port;
dev->cur_server.hostaddrtype = msg->addrtype;
result = dnbd3_net_connect(dev);
break;
case BLKFLSBUF:
break;
default:
result = -EIO;
break;
}
cleanup_return:
if (msg) kfree(msg);
if (imgname) kfree(imgname);
return result;
}
void dnbd3_blk_request(struct request_queue *q)
{
struct request *req;
dnbd3_device_t *dev;
while ((req = blk_fetch_request(q)) != NULL)
{
dev = req->rq_disk->private_data;
if (dev->cur_server.hostaddrtype == 0)
{
__blk_end_request_all(req, -EIO);
continue;
}
if (req->cmd_type != REQ_TYPE_FS)
{
__blk_end_request_all(req, 0);
continue;
}
if (dev->panic_count >= 20)
{
__blk_end_request_all(req, -EIO);
continue;
}
if (rq_data_dir(req) != READ)
{
__blk_end_request_all(req, -EACCES);
continue;
}
list_add_tail(&req->queuelist, &dev->request_queue_send);
spin_unlock_irq(q->queue_lock);
wake_up(&dev->process_queue_send);
spin_lock_irq(q->queue_lock);
}
}
void dnbd3_blk_fail_all_requests(dnbd3_device_t *dev)
{
struct request *blk_request, *tmp_request;
struct request *blk_request2, *tmp_request2;
unsigned long flags;
struct list_head local_copy;
int dup;
INIT_LIST_HEAD(&local_copy);
spin_lock_irq(&dev->blk_lock);
list_for_each_entry_safe(blk_request, tmp_request, &dev->request_queue_receive, queuelist)
{
list_del_init(&blk_request->queuelist);
list_add(&blk_request->queuelist, &local_copy);
}
list_for_each_entry_safe(blk_request, tmp_request, &dev->request_queue_send, queuelist)
{
list_del_init(&blk_request->queuelist);
dup = 0;
list_for_each_entry_safe(blk_request2, tmp_request2, &local_copy, queuelist)
{
if (blk_request == blk_request2)
{
printk("WARNING: Request is in both lists!\n");
dup = 1;
}
}
if (!dup) list_add(&blk_request->queuelist, &local_copy);
}
spin_unlock_irq(&dev->blk_lock);
list_for_each_entry_safe(blk_request, tmp_request, &local_copy, queuelist)
{
list_del_init(&blk_request->queuelist);
if (blk_request->cmd_type == REQ_TYPE_FS)
{
spin_lock_irqsave(&dev->blk_lock, flags);
__blk_end_request_all(blk_request, -EIO);
spin_unlock_irqrestore(&dev->blk_lock, flags);
}
else if (blk_request->cmd_type == REQ_TYPE_SPECIAL)
{
kfree(blk_request);
}
}
}
