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/*
* block.c
*
* Created on: Jun 26, 2019
* Author: fred
*/
#include "dnbd3.h"
#include "block.h"
static int dnbd3_open(struct block_device *bdev, fmode_t mode)
{
dnbd3_device_t *dev = bdev->bd_disk->private_data;
printk(KERN_DEBUG "dnbd3: open device %i\n", dev->minor);
//TODO can be removed?
return 0;
}
static void dnbd3_release(struct gendisk *disk, fmode_t mode)
{
dnbd3_device_t *dev = disk->private_data;
printk(KERN_DEBUG "dnbd3: release device %i\n", dev->minor);
//TODO can be removed?
}
void dnbd3_blk_fail_all_requests(dnbd3_device_t *dev)
{
printk(KERN_DEBUG "dnbd3: fail all requests device %i\n", dev->minor);
}
int dnbd3_net_connect(dnbd3_device_t *dev)
{
printk(KERN_DEBUG "dnbd3: net connect device %i\n", dev->minor);
return 0;
}
int dnbd3_net_disconnect(dnbd3_device_t *dev)
{
printk(KERN_DEBUG "dnbd3: net disconnect device %i\n", dev->minor);
return 0;
}
static int dnbd3_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
{
int result = -100;
dnbd3_device_t *dev = bdev->bd_disk->private_data;
char *imgname = NULL;
dnbd3_ioctl_t *msg = NULL;
printk(KERN_DEBUG "dnbd3: ioctl device %i, cmd %i, arg %lu\n", dev->minor, cmd, arg);
//unsigned long irqflags;
while (dev->disconnecting) {
// do nothing
}
if (arg != 0) {
msg = kmalloc(sizeof(*msg), GFP_KERNEL);
if (msg == NULL) return -ENOMEM;
if (copy_from_user((char *)msg, (char *)arg, 2) != 0 || msg->len != sizeof(*msg)) {
result = -ENOEXEC;
goto cleanup_return;
}
if (copy_from_user((char *)msg, (char *)arg, sizeof(*msg)) != 0) {
result = -ENOENT;
goto cleanup_return;
}
if (msg->imgname != NULL && msg->imgnamelen > 0) {
imgname = kmalloc(msg->imgnamelen + 1, GFP_KERNEL);
if (imgname == NULL) {
result = -ENOMEM;
goto cleanup_return;
}
if (copy_from_user(imgname, msg->imgname, msg->imgnamelen) != 0) {
result = -ENOENT;
goto cleanup_return;
}
imgname[msg->imgnamelen] = '\0';
printk(KERN_DEBUG "dnbd3: ioctl image name of len %i is %s\n", (int)msg->imgnamelen, imgname);
}
}
switch (cmd) {
case IOCTL_OPEN:
printk(KERN_DEBUG "dnbd3: ioctl open\n");
if (dev->imgname != NULL) {
result = -EBUSY;
} else if (imgname == NULL) {
result = -EINVAL;
} else if (msg == NULL) {
result = -EINVAL;
} else {
if (sizeof(msg->host) != sizeof(dev->cur_server.host)) {
printk(KERN_INFO "dnbd3: odd size bug#1 triggered in ioctl\n");
}
memcpy(&dev->cur_server.host, &msg->host, sizeof(msg->host));
dev->cur_server.failures = 0;
memcpy(&dev->initial_server, &dev->cur_server, sizeof(dev->initial_server));
dev->imgname = imgname;
dev->rid = msg->rid;
dev->use_server_provided_alts = msg->use_server_provided_alts;
// Forget all alt servers on explicit connect, set first al server to initial server
memset(dev->alt_servers, 0, sizeof(dev->alt_servers[0])*NUMBER_SERVERS);
memcpy(dev->alt_servers, &dev->initial_server, sizeof(dev->alt_servers[0]));
//#if LINUX_VERSION_CODE >= KERNEL_VERSION(4, 11, 0)
// if (blk_queue->backing_dev_info != NULL) {
// blk_queue->backing_dev_info->ra_pages = (msg->read_ahead_kb * 1024) / PAGE_SIZE;
// }
//#else
// blk_queue->backing_dev_info.ra_pages = (msg->read_ahead_kb * 1024) / PAGE_SIZE;
//#endif
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:
printk(KERN_DEBUG "dnbd3: ioctl close\n");
dnbd3_blk_fail_all_requests(dev);
result = dnbd3_net_disconnect(dev);
dnbd3_blk_fail_all_requests(dev);
set_capacity(dev->disk, 0);
if (dev->imgname) {
kfree(dev->imgname);
dev->imgname = NULL;
}
break;
case IOCTL_SWITCH:
printk(KERN_DEBUG "dnbd3: ioctl switch\n");
result = -EINVAL;
break;
case IOCTL_ADD_SRV:
case IOCTL_REM_SRV:
printk(KERN_DEBUG "dnbd3: ioctl add/rem srv\n");
if (dev->imgname == NULL) {
result = -ENOENT;
} else if (dev->new_servers_num >= NUMBER_SERVERS) {
result = -EAGAIN;
} else if (msg == NULL) {
result = -EINVAL;
} else {
memcpy(&dev->new_servers[dev->new_servers_num].host, &msg->host, sizeof(msg->host));
dev->new_servers[dev->new_servers_num].failures = (cmd == IOCTL_ADD_SRV ? 0 : 1); // 0 = ADD, 1 = REM
++dev->new_servers_num;
result = 0;
}
break;
case BLKFLSBUF:
printk(KERN_DEBUG "dnbd3: ioctl blkflsbuf\n");
result = 0;
break;
default:
printk(KERN_DEBUG "dnbd3: ioctl unhandled cmd\n");
result = -EIO;
break;
}
cleanup_return:
if (msg) kfree(msg);
if (imgname) kfree(imgname);
return result;
}
struct block_device_operations dnbd3_fops =
{
.owner = THIS_MODULE,
.open = dnbd3_open,
.release = dnbd3_release,
.ioctl = dnbd3_ioctl,
.compat_ioctl = dnbd3_ioctl,
};
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