Problem Simulating REMOVAL Media

["Mukund JB." <mukundjb@esntechnologies.co.in>]

Dear Linux Kernel Govers,

Here I am making an attempt to simulate the Removable media in a Simple
block driver module.
It results in a segmentation fault raising the kernel module count to 1
which makes me to reboot it.

I am doing the following when trying to simulate the Removable media:

/******* Simple block Driver request ********/ 
static void sbd_request(request_queue_t *q)
{
    struct request *req;
    int status;

    while ((req = elv_next_request(q)) != NULL) {
      if (! blk_fs_request(req)) {
          printk (KERN_NOTICE "Skip non-CMD request\n");
          end_request(req, 0);
          continue;
      }

    /* Simple memcpy based on the request ; 
  Returns success or failure which is passed to end_that_request_first()
*/
      status = sbd_transfer(&Device, req->sector,
req->current_nr_sectors,
                 req->buffer, rq_data_dir(req));

      // end_request(req, 1);
      if(!end_that_request_first(req, status, req->current_nr_sectors))
{
                  blkdev_dequeue_request(req);
                  end_that_request_last(req);
            }
    }

I issue an IOCTL from the application after the module is loaded and
memory device is mounted.
The IOCTL code executed is as follows:

/* Simulate the Removal Media Disk */
Case REMOVE_MOUNTED_DISK:
            if(Device.bdev)
                  invalidate_bdev(Device.bdev,1);
            del_gendisk(Device.gd);
            put_disk(Device.gd);
            blk_cleanup_queue(Queue);
            vfree(Device.data);
            return 0;

After this, I get a segmentation fault either when I issue a 
#ls /mnt
	OR
When I try to unload the driver module?

Result is module cannot be unloaded, and some times it hangs the console
terminal.

Regards,
Mukund Jampala


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