src/driver/vdi.c

   1 /*
   2  * vdi.h - The driver for virtual disks of VirtualBox
   3  *
   4  * This program is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #ifndef __KERNEL__
  19 #  define __KERNEL__
  20 #endif
  21 #ifndef MODULE
  22 #  define MODULE
  23 #endif
  24
  25 //TODO: Remove? #include <linux/config.h>
  26 #include <linux/module.h>
  27 #include <linux/init.h>
  28
  29
  30 #include <linux/blkdev.h>
  31 #include <linux/errno.h>
  32 #include <linux/fs.h>
  33 #include <linux/genhd.h>
  34 #include <linux/hdreg.h>
  35 #include <linux/kernel.h>
  36 #include <linux/types.h>
  37
  38 static int vdi_major;
  39
  40 #include "vdi.h"
  41
  42
  43 /*
  44  * Some disk parameters
  45  */
  46 static int major    = VDI_MAJOR;
  47 // TODO: Remove below variables?
  48 //static int size     = VDI_SIZE;
  49 //static int blksize  = VDI_BLKSIZE;
  50
  51 static vdi_dev vdi;
  52 static struct request_queue *Queue;
  53
  54 void vdi_request(request_queue_t *q)
  55 {
  56         struct request *req;
  57
  58         while ( (req = elv_next_request(q)) != NULL ) {
  59                 if (!blk_fs_request(req)) {
  60                         end_request(req, 0);
  61                         continue;
  62                 }
  63
  64                 printk("vdi request: sec %lu (nr, %u)\n", req->nr_sectors,
  65                        req->current_nr_sectors);
  66                 // TODO: send data to the daemon
  67
  68
  69                 end_request(req, 1);
  70     }
  71 }
  72
  73
  74 int vdi_ioctl (struct inode *inode, struct file *filp, unsigned int cmd,
  75                unsigned long arg)
  76 {
  77         // Unknown command
  78         return -ENOTTY;
  79 }
  80
  81
  82 static struct block_device_operations vdi_oper = {
  83         .owner = THIS_MODULE,
  84         .ioctl = vdi_ioctl
  85 };
  86
  87
  88 static int __init vdi_init(void)
  89 {
  90         // TODO: Remove this? int result, i;
  91
  92         vdi.size = VDI_SECTORS * VDI_HARDSECT_SIZE;
  93
  94         spin_lock_init(&vdi.lock);
  95
  96         Queue = blk_init_queue(vdi_request, &vdi.lock);
  97         if (Queue == NULL) {
  98                 printk(KERN_WARNING "vdi: Unable to create request queue.\n");
  99                 return -ENOMEM;
 100         }
 101         blk_queue_hardsect_size(Queue, VDI_HARDSECT_SIZE);
 102
 103
 104         /*
 105          * Register your major, and accept a dynamic number
 106          */
 107         major = register_blkdev(vdi_major, "vdi");
 108         if (major < 0) {
 109                 printk(KERN_WARNING "vdi: Unable to get major %d\n", major);
 110                 return major;
 111         }
 112
 113         // Create the gendisk structure
 114         vdi.gd = alloc_disk(16);
 115         if (!vdi.gd) {
 116                 // TODO: Unregister it
 117                 unregister_blkdev(major, "vdi");
 118         }
 119
 120         // Set gendisk fields
 121         vdi.gd->major        = major;
 122         vdi.gd->first_minor  = 0;
 123         vdi.gd->fops         = &vdi_oper;
 124         vdi.gd->private_data = &vdi;
 125         strcpy(vdi.gd->disk_name, "vdi0");
 126         set_capacity(vdi.gd, VDI_SECTORS*(VDI_HARDSECT_SIZE/KERNEL_SECTOR_SIZE));
 127         vdi.gd->queue = Queue;
 128
 129         add_disk(vdi.gd);
 130         printk("vdi: init complete\n");
 131         return 0; /* succeed */
 132 }
 133
 134 static void __exit vdi_exit(void)
 135 {
 136         del_gendisk(vdi.gd);
 137         put_disk(vdi.gd);
 138         unregister_blkdev(major, "vdi");
 139         blk_cleanup_queue(Queue);
 140         printk("vdi: exit complete\n");
 141 }
 142
 143 module_init(vdi_init);
 144 module_exit(vdi_exit);