dasd.c

优龙2410linux2.6.8内核源代码

			   e.g. not _IN_IO */
			cqr->status = DASD_CQR_FAILED;
		cqr->stopclk = get_clock();
		rc = 1;
		break;
	case DASD_CQR_DONE:
	case DASD_CQR_FAILED:
		/* already finished - do nothing */
		break;
	default:
		DEV_MESSAGE(KERN_ALERT, device,
			    "invalid status %02x in request",
			    cqr->status);
		BUG();

	}
	spin_unlock_irqrestore(get_ccwdev_lock(device->cdev), flags);
	dasd_schedule_bh(device);
	return rc;
}

/*
 * SECTION: Block device operations (request queue, partitions, open, release).
 */

/*
 * Dasd request queue function. Called from ll_rw_blk.c
 */
static void
do_dasd_request(request_queue_t * queue)
{
	struct dasd_device *device;

	device = (struct dasd_device *) queue->queuedata;
	spin_lock(get_ccwdev_lock(device->cdev));
	/* Get new request from the block device request queue */
	__dasd_process_blk_queue(device);
	/* Now check if the head of the ccw queue needs to be started. */
	__dasd_start_head(device);
	spin_unlock(get_ccwdev_lock(device->cdev));
}

/*
 * Allocate and initialize request queue.
 */
static int
dasd_alloc_queue(struct dasd_device * device)
{
	device->request_queue = blk_init_queue(do_dasd_request,
					       &device->request_queue_lock);
	if (device->request_queue == NULL)
		return -ENOMEM;

	device->request_queue->queuedata = device;
#if 0
	elevator_exit(device->request_queue);
	rc = elevator_init(device->request_queue, &elevator_noop);
	if (rc) {
		blk_cleanup_queue(device->request_queue);
		return rc;
	}
#endif
	return 0;
}

/*
 * Allocate and initialize request queue.
 */
static void
dasd_setup_queue(struct dasd_device * device)
{
	int max;

	blk_queue_hardsect_size(device->request_queue, device->bp_block);
	max = device->discipline->max_blocks << device->s2b_shift;
	blk_queue_max_sectors(device->request_queue, max);
	blk_queue_max_phys_segments(device->request_queue, -1L);
	blk_queue_max_hw_segments(device->request_queue, -1L);
	blk_queue_max_segment_size(device->request_queue, -1L);
	blk_queue_segment_boundary(device->request_queue, -1L);
}

/*
 * Deactivate and free request queue.
 */
static void
dasd_free_queue(struct dasd_device * device)
{
	if (device->request_queue) {
		blk_cleanup_queue(device->request_queue);
		device->request_queue = NULL;
	}
}

/*
 * Flush request on the request queue.
 */
static void
dasd_flush_request_queue(struct dasd_device * device)
{
	struct request *req;

	if (!device->request_queue)
		return;
	
	spin_lock_irq(&device->request_queue_lock);
	while (!list_empty(&device->request_queue->queue_head)) {
		req = elv_next_request(device->request_queue);
		if (req == NULL)
			break;
		dasd_end_request(req, 0);
		blkdev_dequeue_request(req);
	}
	spin_unlock_irq(&device->request_queue_lock);
}

static int
dasd_open(struct inode *inp, struct file *filp)
{
	struct gendisk *disk = inp->i_bdev->bd_disk;
	struct dasd_device *device = disk->private_data;
	int rc;

        atomic_inc(&device->open_count);
	if (test_bit(DASD_FLAG_OFFLINE, &device->flags)) {
		rc = -ENODEV;
		goto unlock;
	}

	if (!try_module_get(device->discipline->owner)) {
		rc = -EINVAL;
		goto unlock;
	}

	if (dasd_probeonly) {
		MESSAGE(KERN_INFO,
			"No access to device %s due to probeonly mode",
			disk->disk_name);
		rc = -EPERM;
		goto out;
	}

	if (device->state < DASD_STATE_BASIC) {
		DBF_DEV_EVENT(DBF_ERR, device, " %s",
			      " Cannot open unrecognized device");
		rc = -ENODEV;
		goto out;
	}

	return 0;

out:
	module_put(device->discipline->owner);
unlock:
	atomic_dec(&device->open_count);
	return rc;
}

static int
dasd_release(struct inode *inp, struct file *filp)
{
	struct gendisk *disk = inp->i_bdev->bd_disk;
	struct dasd_device *device = disk->private_data;

	atomic_dec(&device->open_count);
	module_put(device->discipline->owner);
	return 0;
}

struct block_device_operations
dasd_device_operations = {
	.owner		= THIS_MODULE,
	.open		= dasd_open,
	.release	= dasd_release,
	.ioctl		= dasd_ioctl,
};


static void
dasd_exit(void)
{
#ifdef CONFIG_PROC_FS
	dasd_proc_exit();
#endif
	dasd_ioctl_exit();
	dasd_gendisk_exit();
	dasd_devmap_exit();
	devfs_remove("dasd");
	if (dasd_debug_area != NULL) {
		debug_unregister(dasd_debug_area);
		dasd_debug_area = NULL;
	}
}

/*
 * SECTION: common functions for ccw_driver use
 */

/* initial attempt at a probe function. this can be simplified once
 * the other detection code is gone */
int
dasd_generic_probe (struct ccw_device *cdev,
		    struct dasd_discipline *discipline)
{
	int ret;

	ret = dasd_add_sysfs_files(cdev);
	if (ret) {
		printk(KERN_WARNING
		       "dasd_generic_probe: could not add sysfs entries "
		       "for %s\n", cdev->dev.bus_id);
	}

	cdev->handler = &dasd_int_handler;

	return ret;
}

/* this will one day be called from a global not_oper handler.
 * It is also used by driver_unregister during module unload */
void
dasd_generic_remove (struct ccw_device *cdev)
{
	struct dasd_device *device;

	dasd_remove_sysfs_files(cdev);
	device = dasd_device_from_cdev(cdev);
	if (IS_ERR(device))
		return;
	if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
		/* Already doing offline processing */
		dasd_put_device(device);
		return;
	}
	/*
	 * This device is removed unconditionally. Set offline
	 * flag to prevent dasd_open from opening it while it is
	 * no quite down yet.
	 */
	dasd_set_target_state(device, DASD_STATE_NEW);
	/* dasd_delete_device destroys the device reference. */
	dasd_delete_device(device);
}

/* activate a device. This is called from dasd_{eckd,fba}_probe() when either
 * the device is detected for the first time and is supposed to be used
 * or the user has started activation through sysfs */
int
dasd_generic_set_online (struct ccw_device *cdev,
			 struct dasd_discipline *discipline)

{
	struct dasd_device *device;
	int rc;

	device = dasd_create_device(cdev);
	if (IS_ERR(device))
		return PTR_ERR(device);

	if (test_bit(DASD_FLAG_USE_DIAG, &device->flags)) {
	  	if (!dasd_diag_discipline_pointer) {
		        printk (KERN_WARNING
				"dasd_generic couldn't online device %s "
				"- discipline DIAG not available\n",
				cdev->dev.bus_id);
			dasd_delete_device(device);
			return -ENODEV;
		}
		discipline = dasd_diag_discipline_pointer;
	}
	device->discipline = discipline;

	rc = discipline->check_device(device);
	if (rc) {
		printk (KERN_WARNING
			"dasd_generic couldn't online device %s "
			"with discipline %s\n", 
			cdev->dev.bus_id, discipline->name);
		dasd_delete_device(device);
		return rc;
	}

	dasd_set_target_state(device, DASD_STATE_ONLINE);
	if (device->state <= DASD_STATE_KNOWN) {
		printk (KERN_WARNING
			"dasd_generic discipline not found for %s\n",
			cdev->dev.bus_id);
		rc = -ENODEV;
		dasd_set_target_state(device, DASD_STATE_NEW);
		dasd_delete_device(device);
	} else
		pr_debug("dasd_generic device %s found\n",
				cdev->dev.bus_id);

	/* FIXME: we have to wait for the root device but we don't want
	 * to wait for each single device but for all at once. */
	wait_event(dasd_init_waitq, _wait_for_device(device));

	dasd_put_device(device);

	return rc;
}

int
dasd_generic_set_offline (struct ccw_device *cdev)
{
	struct dasd_device *device;
	int max_count;

	device = dasd_device_from_cdev(cdev);
	if (IS_ERR(device))
		return PTR_ERR(device);
	if (test_and_set_bit(DASD_FLAG_OFFLINE, &device->flags)) {
		/* Already doing offline processing */
		dasd_put_device(device);
		return 0;
	}
	/*
	 * We must make sure that this device is currently not in use.
	 * The open_count is increased for every opener, that includes
	 * the blkdev_get in dasd_scan_partitions. We are only interested
	 * in the other openers.
	 */
	max_count = device->bdev ? 0 : -1;
	if (atomic_read(&device->open_count) > max_count) {
		printk (KERN_WARNING "Can't offline dasd device with open"
			" count = %i.\n",
			atomic_read(&device->open_count));
		clear_bit(DASD_FLAG_OFFLINE, &device->flags);
		dasd_put_device(device);
		return -EBUSY;
	}
	dasd_set_target_state(device, DASD_STATE_NEW);
	/* dasd_delete_device destroys the device reference. */
	dasd_delete_device(device);

	return 0;
}

int
dasd_generic_notify(struct ccw_device *cdev, int event)
{
	struct dasd_device *device;
	struct dasd_ccw_req *cqr;
	unsigned long flags;
	int ret;

	device = dasd_device_from_cdev(cdev);
	if (IS_ERR(device))
		return 0;
	spin_lock_irqsave(get_ccwdev_lock(cdev), flags);
	ret = 0;
	switch (event) {
	case CIO_GONE:
	case CIO_NO_PATH:
		if (device->state < DASD_STATE_BASIC)
			break;
		/* Device is active. We want to keep it. */
		if (test_bit(DASD_FLAG_DSC_ERROR, &device->flags)) {
			list_for_each_entry(cqr, &device->ccw_queue, list)
				if (cqr->status == DASD_CQR_IN_IO)
					cqr->status = DASD_CQR_FAILED;
			device->stopped |= DASD_STOPPED_DC_EIO;
			dasd_schedule_bh(device);
		} else {
			list_for_each_entry(cqr, &device->ccw_queue, list)
				if (cqr->status == DASD_CQR_IN_IO)
					cqr->status = DASD_CQR_QUEUED;
			device->stopped |= DASD_STOPPED_DC_WAIT;
			dasd_set_timer(device, 0);
		}
		ret = 1;
		break;
	case CIO_OPER:
		/* FIXME: add a sanity check. */
		device->stopped &= ~(DASD_STOPPED_DC_WAIT|DASD_STOPPED_DC_EIO);
		dasd_schedule_bh(device);
		ret = 1;
		break;
	}
	spin_unlock_irqrestore(get_ccwdev_lock(cdev), flags);
	dasd_put_device(device);
	return ret;
}

/*
 * Automatically online either all dasd devices (dasd_autodetect) or
 * all devices specified with dasd= parameters.
 */
void
dasd_generic_auto_online (struct ccw_driver *dasd_discipline_driver)
{
	struct device_driver *drv;
	struct device *d, *dev;
	struct ccw_device *cdev;

	drv = get_driver(&dasd_discipline_driver->driver);
	down_read(&drv->bus->subsys.rwsem);
	dev = NULL;
	list_for_each_entry(d, &drv->devices, driver_list) {
		dev = get_device(d);
		if (!dev)
			continue;
		cdev = to_ccwdev(dev);
		if (dasd_autodetect || dasd_busid_known(cdev->dev.bus_id) == 0)
			ccw_device_set_online(cdev);
		put_device(dev);
	}
	up_read(&drv->bus->subsys.rwsem);
	put_driver(drv);
}

static int __init
dasd_init(void)
{
	int rc;

	init_waitqueue_head(&dasd_init_waitq);

	/* register 'common' DASD debug area, used for all DBF_XXX calls */
	dasd_debug_area = debug_register("dasd", 0, 2, 8 * sizeof (long));
	if (dasd_debug_area == NULL) {
		rc = -ENOMEM;
		goto failed;
	}
	debug_register_view(dasd_debug_area, &debug_hex_ascii_view);
	debug_set_level(dasd_debug_area, DBF_ERR);

	DBF_EVENT(DBF_EMERG, "%s", "debug area created");

	dasd_diag_discipline_pointer = NULL;

	rc = devfs_mk_dir("dasd");
	if (rc)
		goto failed;
	rc = dasd_devmap_init();
	if (rc)
		goto failed;
	rc = dasd_gendisk_init();
	if (rc)
		goto failed;
	rc = dasd_parse();
	if (rc)
		goto failed;
	rc = dasd_ioctl_init();
	if (rc)
		goto failed;
#ifdef CONFIG_PROC_FS
	rc = dasd_proc_init();
	if (rc)
		goto failed;
#endif

	return 0;
failed:
	MESSAGE(KERN_INFO, "%s", "initialization not performed due to errors");
	dasd_exit();
	return rc;
}

module_init(dasd_init);
module_exit(dasd_exit);

EXPORT_SYMBOL(dasd_debug_area);
EXPORT_SYMBOL(dasd_diag_discipline_pointer);

EXPORT_SYMBOL(dasd_add_request_head);
EXPORT_SYMBOL(dasd_add_request_tail);
EXPORT_SYMBOL(dasd_cancel_req);
EXPORT_SYMBOL(dasd_clear_timer);
EXPORT_SYMBOL(dasd_enable_device);
EXPORT_SYMBOL(dasd_int_handler);
EXPORT_SYMBOL(dasd_kfree_request);
EXPORT_SYMBOL(dasd_kick_device);
EXPORT_SYMBOL(dasd_kmalloc_request);
EXPORT_SYMBOL(dasd_schedule_bh);
EXPORT_SYMBOL(dasd_set_target_state);
EXPORT_SYMBOL(dasd_set_timer);
EXPORT_SYMBOL(dasd_sfree_request);
EXPORT_SYMBOL(dasd_sleep_on);
EXPORT_SYMBOL(dasd_sleep_on_immediatly);
EXPORT_SYMBOL(dasd_sleep_on_interruptible);
EXPORT_SYMBOL(dasd_smalloc_request);
EXPORT_SYMBOL(dasd_start_IO);
EXPORT_SYMBOL(dasd_term_IO);

EXPORT_SYMBOL_GPL(dasd_generic_probe);
EXPORT_SYMBOL_GPL(dasd_generic_remove);
EXPORT_SYMBOL_GPL(dasd_generic_notify);
EXPORT_SYMBOL_GPL(dasd_generic_set_online);
EXPORT_SYMBOL_GPL(dasd_generic_set_offline);
EXPORT_SYMBOL_GPL(dasd_generic_auto_online);

/*
 * Overrides for Emacs so that we follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-indent-level: 4
 * c-brace-imaginary-offset: 0
 * c-brace-offset: -4
 * c-argdecl-indent: 4
 * c-label-offset: -4
 * c-continued-statement-offset: 4
 * c-continued-brace-offset: 0
 * indent-tabs-mode: 1
 * tab-width: 8
 * End:
 */