sg.c

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	case SG_NEXT_CMD_LEN:
		result = get_user(val, ip);
		if (result)
			return result;
		sfp->next_cmd_len = (val > 0) ? val : 0;
		return 0;
	case SG_GET_VERSION_NUM:
		return put_user(sg_version_num, ip);
	case SG_GET_ACCESS_COUNT:
		/* faked - we don't have a real access count anymore */
		val = (sdp->device ? 1 : 0);
		return put_user(val, ip);
	case SG_GET_REQUEST_TABLE:
		if (!access_ok(VERIFY_WRITE, p, SZ_SG_REQ_INFO * SG_MAX_QUEUE))
			return -EFAULT;
		else {
			sg_req_info_t *rinfo;
			unsigned int ms;

			rinfo = kmalloc(SZ_SG_REQ_INFO * SG_MAX_QUEUE,
								GFP_KERNEL);
			if (!rinfo)
				return -ENOMEM;
			read_lock_irqsave(&sfp->rq_list_lock, iflags);
			for (srp = sfp->headrp, val = 0; val < SG_MAX_QUEUE;
			     ++val, srp = srp ? srp->nextrp : srp) {
				memset(&rinfo[val], 0, SZ_SG_REQ_INFO);
				if (srp) {
					rinfo[val].req_state = srp->done + 1;
					rinfo[val].problem =
					    srp->header.masked_status & 
					    srp->header.host_status & 
					    srp->header.driver_status;
					if (srp->done)
						rinfo[val].duration =
							srp->header.duration;
					else {
						ms = jiffies_to_msecs(jiffies);
						rinfo[val].duration =
						    (ms > srp->header.duration) ?
						    (ms - srp->header.duration) : 0;
					}
					rinfo[val].orphan = srp->orphan;
					rinfo[val].sg_io_owned =
							srp->sg_io_owned;
					rinfo[val].pack_id =
							srp->header.pack_id;
					rinfo[val].usr_ptr =
							srp->header.usr_ptr;
				}
			}
			read_unlock_irqrestore(&sfp->rq_list_lock, iflags);
			result = __copy_to_user(p, rinfo, 
						SZ_SG_REQ_INFO * SG_MAX_QUEUE);
			result = result ? -EFAULT : 0;
			kfree(rinfo);
			return result;
		}
	case SG_EMULATED_HOST:
		if (sdp->detached)
			return -ENODEV;
		return put_user(sdp->device->host->hostt->emulated, ip);
	case SG_SCSI_RESET:
		if (sdp->detached)
			return -ENODEV;
		if (filp->f_flags & O_NONBLOCK) {
			if (scsi_host_in_recovery(sdp->device->host))
				return -EBUSY;
		} else if (!scsi_block_when_processing_errors(sdp->device))
			return -EBUSY;
		result = get_user(val, ip);
		if (result)
			return result;
		if (SG_SCSI_RESET_NOTHING == val)
			return 0;
		switch (val) {
		case SG_SCSI_RESET_DEVICE:
			val = SCSI_TRY_RESET_DEVICE;
			break;
		case SG_SCSI_RESET_BUS:
			val = SCSI_TRY_RESET_BUS;
			break;
		case SG_SCSI_RESET_HOST:
			val = SCSI_TRY_RESET_HOST;
			break;
		default:
			return -EINVAL;
		}
		if (!capable(CAP_SYS_ADMIN) || !capable(CAP_SYS_RAWIO))
			return -EACCES;
		return (scsi_reset_provider(sdp->device, val) ==
			SUCCESS) ? 0 : -EIO;
	case SCSI_IOCTL_SEND_COMMAND:
		if (sdp->detached)
			return -ENODEV;
		if (read_only) {
			unsigned char opcode = WRITE_6;
			Scsi_Ioctl_Command __user *siocp = p;

			if (copy_from_user(&opcode, siocp->data, 1))
				return -EFAULT;
			if (!sg_allow_access(opcode, sdp->device->type))
				return -EPERM;
		}
		return sg_scsi_ioctl(filp, sdp->device->request_queue, NULL, p);
	case SG_SET_DEBUG:
		result = get_user(val, ip);
		if (result)
			return result;
		sdp->sgdebug = (char) val;
		return 0;
	case SCSI_IOCTL_GET_IDLUN:
	case SCSI_IOCTL_GET_BUS_NUMBER:
	case SCSI_IOCTL_PROBE_HOST:
	case SG_GET_TRANSFORM:
		if (sdp->detached)
			return -ENODEV;
		return scsi_ioctl(sdp->device, cmd_in, p);
	case BLKSECTGET:
		return put_user(sdp->device->request_queue->max_sectors * 512,
				ip);
	default:
		if (read_only)
			return -EPERM;	/* don't know so take safe approach */
		return scsi_ioctl(sdp->device, cmd_in, p);
	}
}

#ifdef CONFIG_COMPAT
static long sg_compat_ioctl(struct file *filp, unsigned int cmd_in, unsigned long arg)
{
	Sg_device *sdp;
	Sg_fd *sfp;
	struct scsi_device *sdev;

	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
		return -ENXIO;

	sdev = sdp->device;
	if (sdev->host->hostt->compat_ioctl) { 
		int ret;

		ret = sdev->host->hostt->compat_ioctl(sdev, cmd_in, (void __user *)arg);

		return ret;
	}
	
	return -ENOIOCTLCMD;
}
#endif

static unsigned int
sg_poll(struct file *filp, poll_table * wait)
{
	unsigned int res = 0;
	Sg_device *sdp;
	Sg_fd *sfp;
	Sg_request *srp;
	int count = 0;
	unsigned long iflags;

	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))
	    || sfp->closed)
		return POLLERR;
	poll_wait(filp, &sfp->read_wait, wait);
	read_lock_irqsave(&sfp->rq_list_lock, iflags);
	for (srp = sfp->headrp; srp; srp = srp->nextrp) {
		/* if any read waiting, flag it */
		if ((0 == res) && (1 == srp->done) && (!srp->sg_io_owned))
			res = POLLIN | POLLRDNORM;
		++count;
	}
	read_unlock_irqrestore(&sfp->rq_list_lock, iflags);

	if (sdp->detached)
		res |= POLLHUP;
	else if (!sfp->cmd_q) {
		if (0 == count)
			res |= POLLOUT | POLLWRNORM;
	} else if (count < SG_MAX_QUEUE)
		res |= POLLOUT | POLLWRNORM;
	SCSI_LOG_TIMEOUT(3, printk("sg_poll: %s, res=0x%x\n",
				   sdp->disk->disk_name, (int) res));
	return res;
}

static int
sg_fasync(int fd, struct file *filp, int mode)
{
	int retval;
	Sg_device *sdp;
	Sg_fd *sfp;

	if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp)))
		return -ENXIO;
	SCSI_LOG_TIMEOUT(3, printk("sg_fasync: %s, mode=%d\n",
				   sdp->disk->disk_name, mode));

	retval = fasync_helper(fd, filp, mode, &sfp->async_qp);
	return (retval < 0) ? retval : 0;
}

static struct page *
sg_vma_nopage(struct vm_area_struct *vma, unsigned long addr, int *type)
{
	Sg_fd *sfp;
	struct page *page = NOPAGE_SIGBUS;
	unsigned long offset, len, sa;
	Sg_scatter_hold *rsv_schp;
	struct scatterlist *sg;
	int k;

	if ((NULL == vma) || (!(sfp = (Sg_fd *) vma->vm_private_data)))
		return page;
	rsv_schp = &sfp->reserve;
	offset = addr - vma->vm_start;
	if (offset >= rsv_schp->bufflen)
		return page;
	SCSI_LOG_TIMEOUT(3, printk("sg_vma_nopage: offset=%lu, scatg=%d\n",
				   offset, rsv_schp->k_use_sg));
	sg = rsv_schp->buffer;
	sa = vma->vm_start;
	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
	     ++k, sg = sg_next(sg)) {
		len = vma->vm_end - sa;
		len = (len < sg->length) ? len : sg->length;
		if (offset < len) {
			page = virt_to_page(page_address(sg_page(sg)) + offset);
			get_page(page);	/* increment page count */
			break;
		}
		sa += len;
		offset -= len;
	}

	if (type)
		*type = VM_FAULT_MINOR;
	return page;
}

static struct vm_operations_struct sg_mmap_vm_ops = {
	.nopage = sg_vma_nopage,
};

static int
sg_mmap(struct file *filp, struct vm_area_struct *vma)
{
	Sg_fd *sfp;
	unsigned long req_sz, len, sa;
	Sg_scatter_hold *rsv_schp;
	int k;
	struct scatterlist *sg;

	if ((!filp) || (!vma) || (!(sfp = (Sg_fd *) filp->private_data)))
		return -ENXIO;
	req_sz = vma->vm_end - vma->vm_start;
	SCSI_LOG_TIMEOUT(3, printk("sg_mmap starting, vm_start=%p, len=%d\n",
				   (void *) vma->vm_start, (int) req_sz));
	if (vma->vm_pgoff)
		return -EINVAL;	/* want no offset */
	rsv_schp = &sfp->reserve;
	if (req_sz > rsv_schp->bufflen)
		return -ENOMEM;	/* cannot map more than reserved buffer */

	sa = vma->vm_start;
	sg = rsv_schp->buffer;
	for (k = 0; (k < rsv_schp->k_use_sg) && (sa < vma->vm_end);
	     ++k, sg = sg_next(sg)) {
		len = vma->vm_end - sa;
		len = (len < sg->length) ? len : sg->length;
		sa += len;
	}

	sfp->mmap_called = 1;
	vma->vm_flags |= VM_RESERVED;
	vma->vm_private_data = sfp;
	vma->vm_ops = &sg_mmap_vm_ops;
	return 0;
}

/* This function is a "bottom half" handler that is called by the
 * mid level when a command is completed (or has failed). */
static void
sg_cmd_done(void *data, char *sense, int result, int resid)
{
	Sg_request *srp = data;
	Sg_device *sdp = NULL;
	Sg_fd *sfp;
	unsigned long iflags;
	unsigned int ms;

	if (NULL == srp) {
		printk(KERN_ERR "sg_cmd_done: NULL request\n");
		return;
	}
	sfp = srp->parentfp;
	if (sfp)
		sdp = sfp->parentdp;
	if ((NULL == sdp) || sdp->detached) {
		printk(KERN_INFO "sg_cmd_done: device detached\n");
		return;
	}


	SCSI_LOG_TIMEOUT(4, printk("sg_cmd_done: %s, pack_id=%d, res=0x%x\n",
		sdp->disk->disk_name, srp->header.pack_id, result));
	srp->header.resid = resid;
	ms = jiffies_to_msecs(jiffies);
	srp->header.duration = (ms > srp->header.duration) ?
				(ms - srp->header.duration) : 0;
	if (0 != result) {
		struct scsi_sense_hdr sshdr;

		memcpy(srp->sense_b, sense, sizeof (srp->sense_b));
		srp->header.status = 0xff & result;
		srp->header.masked_status = status_byte(result);
		srp->header.msg_status = msg_byte(result);
		srp->header.host_status = host_byte(result);
		srp->header.driver_status = driver_byte(result);
		if ((sdp->sgdebug > 0) &&
		    ((CHECK_CONDITION == srp->header.masked_status) ||
		     (COMMAND_TERMINATED == srp->header.masked_status)))
			__scsi_print_sense("sg_cmd_done", sense,
					   SCSI_SENSE_BUFFERSIZE);

		/* Following if statement is a patch supplied by Eric Youngdale */
		if (driver_byte(result) != 0
		    && scsi_normalize_sense(sense, SCSI_SENSE_BUFFERSIZE, &sshdr)
		    && !scsi_sense_is_deferred(&sshdr)
		    && sshdr.sense_key == UNIT_ATTENTION
		    && sdp->device->removable) {
			/* Detected possible disc change. Set the bit - this */
			/* may be used if there are filesystems using this device */
			sdp->device->changed = 1;
		}
	}
	/* Rely on write phase to clean out srp status values, so no "else" */

	if (sfp->closed) {	/* whoops this fd already released, cleanup */
		SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, freeing ...\n"));
		sg_finish_rem_req(srp);
		srp = NULL;
		if (NULL == sfp->headrp) {
			SCSI_LOG_TIMEOUT(1, printk("sg_cmd_done: already closed, final cleanup\n"));
			if (0 == sg_remove_sfp(sdp, sfp)) {	/* device still present */
				scsi_device_put(sdp->device);
			}
			sfp = NULL;
		}
	} else if (srp && srp->orphan) {
		if (sfp->keep_orphan)
			srp->sg_io_owned = 0;
		else {
			sg_finish_rem_req(srp);
			srp = NULL;
		}
	}
	if (sfp && srp) {
		/* Now wake up any sg_read() that is waiting for this packet. */
		kill_fasync(&sfp->async_qp, SIGPOLL, POLL_IN);
		write_lock_irqsave(&sfp->rq_list_lock, iflags);
		srp->done = 1;
		wake_up_interruptible(&sfp->read_wait);
		write_unlock_irqrestore(&sfp->rq_list_lock, iflags);
	}
}

static struct file_operations sg_fops = {
	.owner = THIS_MODULE,
	.read = sg_read,
	.write = sg_write,
	.poll = sg_poll,
	.ioctl = sg_ioctl,
#ifdef CONFIG_COMPAT
	.compat_ioctl = sg_compat_ioctl,
#endif
	.open = sg_open,
	.mmap = sg_mmap,
	.release = sg_release,
	.fasync = sg_fasync,
};

static struct class *sg_sysfs_class;

static int sg_sysfs_valid = 0;

static Sg_device *sg_alloc(struct gendisk *disk, struct scsi_device *scsidp)
{
	struct request_queue *q = scsidp->request_queue;
	Sg_device *sdp;
	unsigned long iflags;
	int error;
	u32 k;

	sdp = kzalloc(sizeof(Sg_device), GFP_KERNEL);
	if (!sdp) {
		printk(KERN_WARNING "kmalloc Sg_device failure\n");
		return ERR_PTR(-ENOMEM);
	}
	error = -ENOMEM;
	if (!idr_pre_get(&sg_index_idr, GFP_KERNEL)) {
		printk(KERN_WARNING "idr expansion Sg_device failure\n");
		goto out;
	}

	write_lock_irqsave(&sg_index_lock, iflags);
	error = idr_get_new(&sg_index_idr, sdp, &k);
	write_unlock_irqrestore(&sg_index_lock, iflags);

	if (error) {
		printk(KERN_WARNING "idr allocation Sg_device failure: %d\n",
		       error);
		goto out;
	}

	if (unlikely(k >= SG_MAX_DEVS))
		goto overflow;

	SCSI_LOG_TIMEOUT(3, printk("sg_alloc: dev=%d \n", k));
	sprintf(disk->disk_name, "sg%d", k);
	disk->first_minor = k;
	sdp->disk = disk;
	sdp->device = scsidp;
	init_waitqueue_head(&sdp->o_excl_wait);
	sdp->sg_tablesize = min(q->max_hw_segments, q->max_phys_segments);
	sdp->index = k;

	error = 0;
 out:
	if (error) {
		kfree(sdp);
		return ERR_PTR(error);
	}
	return sdp;

 overflow:
	sdev_printk(KERN_WARNING, scsidp,
		    "Unable to attach sg device type=%d, minor "
		    "number exceeds %d\n", scsidp->type, SG_MAX_DEVS - 1);
	error = -ENODEV;
	goto out;
}

static int
sg_add(struct class_device *cl_dev, struct class_interface *cl_intf)
{
	struct scsi_device *scsidp = to_scsi_device(cl_dev->dev);
	struct gendisk *disk;
	Sg_device *sdp = NULL;
	struct cdev * cdev = NULL;
	int error;
	unsigned long iflags;

	disk = alloc_disk(1);
	if (!disk) {
		printk(KERN_WARNING "alloc_disk failed\n");
		return -ENOMEM;
	}
	disk->major = SCSI_GENERIC_MAJOR;

	error = -ENOMEM;
	cdev = cdev_alloc();
	if (!cdev) {
		printk(KERN_WARNING "cdev_alloc failed\n");
		goto out;
	}
	cdev->owner = THIS_MODULE;
	cdev->ops = &sg_fops;

	sdp = sg_alloc(disk, scsidp);
	if (IS_ERR(sdp)) {
		printk(KERN_WARNING "sg_alloc failed\n");