scsi_sysfs.c

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store_rescan_field (struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	scsi_rescan_device(dev);
	return count;
}
static DEVICE_ATTR(rescan, S_IWUSR, NULL, store_rescan_field);

static void sdev_store_delete_callback(struct device *dev)
{
	scsi_remove_device(to_scsi_device(dev));
}

static ssize_t sdev_store_delete(struct device *dev, struct device_attribute *attr, const char *buf,
				 size_t count)
{
	int rc;

	/* An attribute cannot be unregistered by one of its own methods,
	 * so we have to use this roundabout approach.
	 */
	rc = device_schedule_callback(dev, sdev_store_delete_callback);
	if (rc)
		count = rc;
	return count;
};
static DEVICE_ATTR(delete, S_IWUSR, NULL, sdev_store_delete);

static ssize_t
store_state_field(struct device *dev, struct device_attribute *attr, const char *buf, size_t count)
{
	int i;
	struct scsi_device *sdev = to_scsi_device(dev);
	enum scsi_device_state state = 0;

	for (i = 0; i < ARRAY_SIZE(sdev_states); i++) {
		const int len = strlen(sdev_states[i].name);
		if (strncmp(sdev_states[i].name, buf, len) == 0 &&
		   buf[len] == '\n') {
			state = sdev_states[i].value;
			break;
		}
	}
	if (!state)
		return -EINVAL;

	if (scsi_device_set_state(sdev, state))
		return -EINVAL;
	return count;
}

static ssize_t
show_state_field(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct scsi_device *sdev = to_scsi_device(dev);
	const char *name = scsi_device_state_name(sdev->sdev_state);

	if (!name)
		return -EINVAL;

	return snprintf(buf, 20, "%s\n", name);
}

static DEVICE_ATTR(state, S_IRUGO | S_IWUSR, show_state_field, store_state_field);

static ssize_t
show_queue_type_field(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct scsi_device *sdev = to_scsi_device(dev);
	const char *name = "none";

	if (sdev->ordered_tags)
		name = "ordered";
	else if (sdev->simple_tags)
		name = "simple";

	return snprintf(buf, 20, "%s\n", name);
}

static DEVICE_ATTR(queue_type, S_IRUGO, show_queue_type_field, NULL);

static ssize_t
show_iostat_counterbits(struct device *dev, struct device_attribute *attr, char *buf)
{
	return snprintf(buf, 20, "%d\n", (int)sizeof(atomic_t) * 8);
}

static DEVICE_ATTR(iocounterbits, S_IRUGO, show_iostat_counterbits, NULL);

#define show_sdev_iostat(field)						\
static ssize_t								\
show_iostat_##field(struct device *dev, struct device_attribute *attr, char *buf)			\
{									\
	struct scsi_device *sdev = to_scsi_device(dev);			\
	unsigned long long count = atomic_read(&sdev->field);		\
	return snprintf(buf, 20, "0x%llx\n", count);			\
}									\
static DEVICE_ATTR(field, S_IRUGO, show_iostat_##field, NULL)

show_sdev_iostat(iorequest_cnt);
show_sdev_iostat(iodone_cnt);
show_sdev_iostat(ioerr_cnt);

static ssize_t
sdev_show_modalias(struct device *dev, struct device_attribute *attr, char *buf)
{
	struct scsi_device *sdev;
	sdev = to_scsi_device(dev);
	return snprintf (buf, 20, SCSI_DEVICE_MODALIAS_FMT "\n", sdev->type);
}
static DEVICE_ATTR(modalias, S_IRUGO, sdev_show_modalias, NULL);

#define DECLARE_EVT_SHOW(name, Cap_name)				\
static ssize_t								\
sdev_show_evt_##name(struct device *dev, struct device_attribute *attr,	\
				char *buf)				\
{									\
	struct scsi_device *sdev = to_scsi_device(dev);			\
	int val = test_bit(SDEV_EVT_##Cap_name, sdev->supported_events);\
	return snprintf(buf, 20, "%d\n", val);				\
}

#define DECLARE_EVT_STORE(name, Cap_name)				\
static ssize_t								\
sdev_store_evt_##name(struct device *dev, struct device_attribute *attr, \
		      const char *buf, size_t count)			\
{									\
	struct scsi_device *sdev = to_scsi_device(dev);			\
	int val = simple_strtoul(buf, NULL, 0);				\
	if (val == 0)							\
		clear_bit(SDEV_EVT_##Cap_name, sdev->supported_events);	\
	else if (val == 1)						\
		set_bit(SDEV_EVT_##Cap_name, sdev->supported_events);	\
	else								\
		return -EINVAL;						\
	return count;							\
}

#define DECLARE_EVT(name, Cap_name)					\
	DECLARE_EVT_SHOW(name, Cap_name)				\
	DECLARE_EVT_STORE(name, Cap_name)				\
	static DEVICE_ATTR(evt_##name, S_IRUGO, sdev_show_evt_##name,	\
			   sdev_store_evt_##name);
#define REF_EVT(name) &dev_attr_evt_##name.attr

DECLARE_EVT(media_change, MEDIA_CHANGE)

/* Default template for device attributes.  May NOT be modified */
static struct attribute *scsi_sdev_attrs[] = {
	&dev_attr_device_blocked.attr,
	&dev_attr_type.attr,
	&dev_attr_scsi_level.attr,
	&dev_attr_vendor.attr,
	&dev_attr_model.attr,
	&dev_attr_rev.attr,
	&dev_attr_rescan.attr,
	&dev_attr_delete.attr,
	&dev_attr_state.attr,
	&dev_attr_timeout.attr,
	&dev_attr_iocounterbits.attr,
	&dev_attr_iorequest_cnt.attr,
	&dev_attr_iodone_cnt.attr,
	&dev_attr_ioerr_cnt.attr,
	&dev_attr_modalias.attr,
	REF_EVT(media_change),
	NULL
};

static struct attribute_group scsi_sdev_attr_group = {
	.attrs =	scsi_sdev_attrs,
};

static struct attribute_group *scsi_sdev_attr_groups[] = {
	&scsi_sdev_attr_group,
	NULL
};

static ssize_t sdev_store_queue_depth_rw(struct device *dev, struct device_attribute *attr, const char *buf,
					 size_t count)
{
	int depth, retval;
	struct scsi_device *sdev = to_scsi_device(dev);
	struct scsi_host_template *sht = sdev->host->hostt;

	if (!sht->change_queue_depth)
		return -EINVAL;

	depth = simple_strtoul(buf, NULL, 0);

	if (depth < 1)
		return -EINVAL;

	retval = sht->change_queue_depth(sdev, depth);
	if (retval < 0)
		return retval;

	return count;
}

static struct device_attribute sdev_attr_queue_depth_rw =
	__ATTR(queue_depth, S_IRUGO | S_IWUSR, sdev_show_queue_depth,
	       sdev_store_queue_depth_rw);

static ssize_t sdev_store_queue_type_rw(struct device *dev, struct device_attribute *attr, const char *buf,
					size_t count)
{
	struct scsi_device *sdev = to_scsi_device(dev);
	struct scsi_host_template *sht = sdev->host->hostt;
	int tag_type = 0, retval;
	int prev_tag_type = scsi_get_tag_type(sdev);

	if (!sdev->tagged_supported || !sht->change_queue_type)
		return -EINVAL;

	if (strncmp(buf, "ordered", 7) == 0)
		tag_type = MSG_ORDERED_TAG;
	else if (strncmp(buf, "simple", 6) == 0)
		tag_type = MSG_SIMPLE_TAG;
	else if (strncmp(buf, "none", 4) != 0)
		return -EINVAL;

	if (tag_type == prev_tag_type)
		return count;

	retval = sht->change_queue_type(sdev, tag_type);
	if (retval < 0)
		return retval;

	return count;
}

static struct device_attribute sdev_attr_queue_type_rw =
	__ATTR(queue_type, S_IRUGO | S_IWUSR, show_queue_type_field,
	       sdev_store_queue_type_rw);

/**
 * scsi_sysfs_add_sdev - add scsi device to sysfs
 * @sdev:	scsi_device to add
 *
 * Return value:
 * 	0 on Success / non-zero on Failure
 **/
int scsi_sysfs_add_sdev(struct scsi_device *sdev)
{
	int error, i;
	struct request_queue *rq = sdev->request_queue;

	if ((error = scsi_device_set_state(sdev, SDEV_RUNNING)) != 0)
		return error;

	error = device_add(&sdev->sdev_gendev);
	if (error) {
		put_device(sdev->sdev_gendev.parent);
		printk(KERN_INFO "error 1\n");
		return error;
	}
	error = class_device_add(&sdev->sdev_classdev);
	if (error) {
		printk(KERN_INFO "error 2\n");
		goto clean_device;
	}

	/* take a reference for the sdev_classdev; this is
	 * released by the sdev_class .release */
	get_device(&sdev->sdev_gendev);

	/* create queue files, which may be writable, depending on the host */
	if (sdev->host->hostt->change_queue_depth)
		error = device_create_file(&sdev->sdev_gendev, &sdev_attr_queue_depth_rw);
	else
		error = device_create_file(&sdev->sdev_gendev, &dev_attr_queue_depth);
	if (error) {
		__scsi_remove_device(sdev);
		goto out;
	}
	if (sdev->host->hostt->change_queue_type)
		error = device_create_file(&sdev->sdev_gendev, &sdev_attr_queue_type_rw);
	else
		error = device_create_file(&sdev->sdev_gendev, &dev_attr_queue_type);
	if (error) {
		__scsi_remove_device(sdev);
		goto out;
	}

	error = bsg_register_queue(rq, &sdev->sdev_gendev, NULL);

	if (error)
		sdev_printk(KERN_INFO, sdev,
			    "Failed to register bsg queue, errno=%d\n", error);

	/* we're treating error on bsg register as non-fatal, so pretend
	 * nothing went wrong */
	error = 0;

	/* add additional host specific attributes */
	if (sdev->host->hostt->sdev_attrs) {
		for (i = 0; sdev->host->hostt->sdev_attrs[i]; i++) {
			error = device_create_file(&sdev->sdev_gendev,
					sdev->host->hostt->sdev_attrs[i]);
			if (error) {
				__scsi_remove_device(sdev);
				goto out;
			}
		}
	}

	transport_add_device(&sdev->sdev_gendev);
 out:
	return error;

 clean_device:
	scsi_device_set_state(sdev, SDEV_CANCEL);

	device_del(&sdev->sdev_gendev);
	transport_destroy_device(&sdev->sdev_gendev);
	put_device(&sdev->sdev_gendev);

	return error;
}

void __scsi_remove_device(struct scsi_device *sdev)
{
	struct device *dev = &sdev->sdev_gendev;

	if (scsi_device_set_state(sdev, SDEV_CANCEL) != 0)
		return;

	bsg_unregister_queue(sdev->request_queue);
	class_device_unregister(&sdev->sdev_classdev);
	transport_remove_device(dev);
	device_del(dev);
	scsi_device_set_state(sdev, SDEV_DEL);
	if (sdev->host->hostt->slave_destroy)
		sdev->host->hostt->slave_destroy(sdev);
	transport_destroy_device(dev);
	put_device(dev);
}

/**
 * scsi_remove_device - unregister a device from the scsi bus
 * @sdev:	scsi_device to unregister
 **/
void scsi_remove_device(struct scsi_device *sdev)
{
	struct Scsi_Host *shost = sdev->host;

	mutex_lock(&shost->scan_mutex);
	__scsi_remove_device(sdev);
	mutex_unlock(&shost->scan_mutex);
}
EXPORT_SYMBOL(scsi_remove_device);

static void __scsi_remove_target(struct scsi_target *starget)
{
	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
	unsigned long flags;
	struct scsi_device *sdev;

	spin_lock_irqsave(shost->host_lock, flags);
	starget->reap_ref++;
 restart:
	list_for_each_entry(sdev, &shost->__devices, siblings) {
		if (sdev->channel != starget->channel ||
		    sdev->id != starget->id ||
		    sdev->sdev_state == SDEV_DEL)
			continue;
		spin_unlock_irqrestore(shost->host_lock, flags);
		scsi_remove_device(sdev);
		spin_lock_irqsave(shost->host_lock, flags);
		goto restart;
	}
	spin_unlock_irqrestore(shost->host_lock, flags);
	scsi_target_reap(starget);
}

static int __remove_child (struct device * dev, void * data)
{
	if (scsi_is_target_device(dev))
		__scsi_remove_target(to_scsi_target(dev));
	return 0;
}

/**
 * scsi_remove_target - try to remove a target and all its devices
 * @dev: generic starget or parent of generic stargets to be removed
 *
 * Note: This is slightly racy.  It is possible that if the user
 * requests the addition of another device then the target won't be
 * removed.
 */
void scsi_remove_target(struct device *dev)
{
	struct device *rdev;

	if (scsi_is_target_device(dev)) {
		__scsi_remove_target(to_scsi_target(dev));
		return;
	}

	rdev = get_device(dev);
	device_for_each_child(dev, NULL, __remove_child);
	put_device(rdev);
}
EXPORT_SYMBOL(scsi_remove_target);

int scsi_register_driver(struct device_driver *drv)
{
	drv->bus = &scsi_bus_type;

	return driver_register(drv);
}
EXPORT_SYMBOL(scsi_register_driver);

int scsi_register_interface(struct class_interface *intf)
{
	intf->class = &sdev_class;

	return class_interface_register(intf);
}
EXPORT_SYMBOL(scsi_register_interface);


static struct class_device_attribute *class_attr_overridden(
		struct class_device_attribute **attrs,
		struct class_device_attribute *attr)
{
	int i;

	if (!attrs)
		return NULL;
	for (i = 0; attrs[i]; i++)
		if (!strcmp(attrs[i]->attr.name, attr->attr.name))
			return attrs[i];
	return NULL;
}

static int class_attr_add(struct class_device *classdev,
		struct class_device_attribute *attr)
{
	struct class_device_attribute *base_attr;

	/*
	 * Spare the caller from having to copy things it's not interested in.
	 */
	base_attr = class_attr_overridden(scsi_sysfs_shost_attrs, attr);
	if (base_attr) {
		/* extend permissions */
		attr->attr.mode |= base_attr->attr.mode;

		/* override null show/store with default */
		if (!attr->show)
			attr->show = base_attr->show;
		if (!attr->store)
			attr->store = base_attr->store;
	}

	return class_device_create_file(classdev, attr);
}

/**
 * scsi_sysfs_add_host - add scsi host to subsystem
 * @shost:     scsi host struct to add to subsystem
 * @dev:       parent struct device pointer
 **/
int scsi_sysfs_add_host(struct Scsi_Host *shost)
{
	int error, i;

	if (shost->hostt->shost_attrs) {
		for (i = 0; shost->hostt->shost_attrs[i]; i++) {
			error = class_attr_add(&shost->shost_classdev,
					shost->hostt->shost_attrs[i]);
			if (error)
				return error;
		}
	}

	for (i = 0; scsi_sysfs_shost_attrs[i]; i++) {
		if (!class_attr_overridden(shost->hostt->shost_attrs,
					scsi_sysfs_shost_attrs[i])) {
			error = class_device_create_file(&shost->shost_classdev,
					scsi_sysfs_shost_attrs[i]);
			if (error)
				return error;
		}
	}

	transport_register_device(&shost->shost_gendev);
	return 0;
}

static struct device_type scsi_dev_type = {
	.name =		"scsi_device",
	.release =	scsi_device_dev_release,
	.groups =	scsi_sdev_attr_groups,
};

void scsi_sysfs_device_initialize(struct scsi_device *sdev)
{
	unsigned long flags;
	struct Scsi_Host *shost = sdev->host;
	struct scsi_target  *starget = sdev->sdev_target;

	device_initialize(&sdev->sdev_gendev);
	sdev->sdev_gendev.bus = &scsi_bus_type;
	sdev->sdev_gendev.type = &scsi_dev_type;
	sprintf(sdev->sdev_gendev.bus_id,"%d:%d:%d:%d",
		sdev->host->host_no, sdev->channel, sdev->id,
		sdev->lun);
	
	class_device_initialize(&sdev->sdev_classdev);
	sdev->sdev_classdev.dev = &sdev->sdev_gendev;
	sdev->sdev_classdev.class = &sdev_class;
	snprintf(sdev->sdev_classdev.class_id, BUS_ID_SIZE,
		 "%d:%d:%d:%d", sdev->host->host_no,
		 sdev->channel, sdev->id, sdev->lun);
	sdev->scsi_level = starget->scsi_level;
	transport_setup_device(&sdev->sdev_gendev);
	spin_lock_irqsave(shost->host_lock, flags);
	list_add_tail(&sdev->same_target_siblings, &starget->devices);
	list_add_tail(&sdev->siblings, &shost->__devices);
	spin_unlock_irqrestore(shost->host_lock, flags);
}

int scsi_is_sdev_device(const struct device *dev)
{
	return dev->type == &scsi_dev_type;
}
EXPORT_SYMBOL(scsi_is_sdev_device);

/* A blank transport template that is used in drivers that don't
 * yet implement Transport Attributes */
struct scsi_transport_template blank_transport_template = { { { {NULL, }, }, }, };