diff options
Diffstat (limited to 'src/kernel/block.c')
| -rw-r--r-- | src/kernel/block.c | 193 |
1 files changed, 193 insertions, 0 deletions
diff --git a/src/kernel/block.c b/src/kernel/block.c new file mode 100644 index 0000000..bd2f8d7 --- /dev/null +++ b/src/kernel/block.c @@ -0,0 +1,193 @@ +/* + * 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, +}; + + |