cdev.c

来自「基于linux-2.6.28的mtd驱动」· C语言 代码 · 共 1,011 行 · 第 1/2 页

		if (lnum < 0 || lnum >= vol->reserved_pebs) {
			err = -EINVAL;
			break;
		}

		dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
		err = ubi_eba_unmap_leb(ubi, vol, lnum);
		if (err)
			break;

		err = ubi_wl_flush(ubi);
		break;
	}
#endif

	default:
		err = -ENOTTY;
		break;
	}

	return err;
}

/**
 * verify_mkvol_req - verify volume creation request.
 * @ubi: UBI device description object
 * @req: the request to check
 *
 * This function zero if the request is correct, and %-EINVAL if not.
 */
static int verify_mkvol_req(const struct ubi_device *ubi,
			    const struct ubi_mkvol_req *req)
{
	int n, err = -EINVAL;

	if (req->bytes < 0 || req->alignment < 0 || req->vol_type < 0 ||
	    req->name_len < 0)
		goto bad;

	if ((req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots) &&
	    req->vol_id != UBI_VOL_NUM_AUTO)
		goto bad;

	if (req->alignment == 0)
		goto bad;

	if (req->bytes == 0)
		goto bad;

	if (req->vol_type != UBI_DYNAMIC_VOLUME &&
	    req->vol_type != UBI_STATIC_VOLUME)
		goto bad;

	if (req->alignment > ubi->leb_size)
		goto bad;

	n = req->alignment & (ubi->min_io_size - 1);
	if (req->alignment != 1 && n)
		goto bad;

	if (req->name_len > UBI_VOL_NAME_MAX) {
		err = -ENAMETOOLONG;
		goto bad;
	}

	n = strnlen(req->name, req->name_len + 1);
	if (n != req->name_len)
		goto bad;

	return 0;

bad:
	dbg_err("bad volume creation request");
	ubi_dbg_dump_mkvol_req(req);
	return err;
}

/**
 * verify_rsvol_req - verify volume re-size request.
 * @ubi: UBI device description object
 * @req: the request to check
 *
 * This function returns zero if the request is correct, and %-EINVAL if not.
 */
static int verify_rsvol_req(const struct ubi_device *ubi,
			    const struct ubi_rsvol_req *req)
{
	if (req->bytes <= 0)
		return -EINVAL;

	if (req->vol_id < 0 || req->vol_id >= ubi->vtbl_slots)
		return -EINVAL;

	return 0;
}

/**
 * rename_volumes - rename UBI volumes.
 * @ubi: UBI device description object
 * @req: volumes re-name request
 *
 * This is a helper function for the volume re-name IOCTL which validates the
 * the request, opens the volume and calls corresponding volumes management
 * function. Returns zero in case of success and a negative error code in case
 * of failure.
 */
static int rename_volumes(struct ubi_device *ubi,
			  struct ubi_rnvol_req *req)
{
	int i, n, err;
	struct list_head rename_list;
	struct ubi_rename_entry *re, *re1;

	if (req->count < 0 || req->count > UBI_MAX_RNVOL)
		return -EINVAL;

	if (req->count == 0)
		return 0;

	/* Validate volume IDs and names in the request */
	for (i = 0; i < req->count; i++) {
		if (req->ents[i].vol_id < 0 ||
		    req->ents[i].vol_id >= ubi->vtbl_slots)
			return -EINVAL;
		if (req->ents[i].name_len < 0)
			return -EINVAL;
		if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
			return -ENAMETOOLONG;
		req->ents[i].name[req->ents[i].name_len] = '\0';
		n = strlen(req->ents[i].name);
		if (n != req->ents[i].name_len)
			err = -EINVAL;
	}

	/* Make sure volume IDs and names are unique */
	for (i = 0; i < req->count - 1; i++) {
		for (n = i + 1; n < req->count; n++) {
			if (req->ents[i].vol_id == req->ents[n].vol_id) {
				dbg_err("duplicated volume id %d",
					req->ents[i].vol_id);
				return -EINVAL;
			}
			if (!strcmp(req->ents[i].name, req->ents[n].name)) {
				dbg_err("duplicated volume name \"%s\"",
					req->ents[i].name);
				return -EINVAL;
			}
		}
	}

	/* Create the re-name list */
	INIT_LIST_HEAD(&rename_list);
	for (i = 0; i < req->count; i++) {
		int vol_id = req->ents[i].vol_id;
		int name_len = req->ents[i].name_len;
		const char *name = req->ents[i].name;

		re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
		if (!re) {
			err = -ENOMEM;
			goto out_free;
		}

		re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
		if (IS_ERR(re->desc)) {
			err = PTR_ERR(re->desc);
			dbg_err("cannot open volume %d, error %d", vol_id, err);
			kfree(re);
			goto out_free;
		}

		/* Skip this re-naming if the name does not really change */
		if (re->desc->vol->name_len == name_len &&
		    !memcmp(re->desc->vol->name, name, name_len)) {
			ubi_close_volume(re->desc);
			kfree(re);
			continue;
		}

		re->new_name_len = name_len;
		memcpy(re->new_name, name, name_len);
		list_add_tail(&re->list, &rename_list);
		dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
			vol_id, re->desc->vol->name, name);
	}

	if (list_empty(&rename_list))
		return 0;

	/* Find out the volumes which have to be removed */
	list_for_each_entry(re, &rename_list, list) {
		struct ubi_volume_desc *desc;
		int no_remove_needed = 0;

		/*
		 * Volume @re->vol_id is going to be re-named to
		 * @re->new_name, while its current name is @name. If a volume
		 * with name @re->new_name currently exists, it has to be
		 * removed, unless it is also re-named in the request (@req).
		 */
		list_for_each_entry(re1, &rename_list, list) {
			if (re->new_name_len == re1->desc->vol->name_len &&
			    !memcmp(re->new_name, re1->desc->vol->name,
				    re1->desc->vol->name_len)) {
				no_remove_needed = 1;
				break;
			}
		}

		if (no_remove_needed)
			continue;

		/*
		 * It seems we need to remove volume with name @re->new_name,
		 * if it exists.
		 */
		desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name, UBI_EXCLUSIVE);
		if (IS_ERR(desc)) {
			err = PTR_ERR(desc);
			if (err == -ENODEV)
				/* Re-naming into a non-existing volume name */
				continue;

			/* The volume exists but busy, or an error occurred */
			dbg_err("cannot open volume \"%s\", error %d",
				re->new_name, err);
			goto out_free;
		}

		re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
		if (!re) {
			err = -ENOMEM;
			ubi_close_volume(desc);
			goto out_free;
		}

		re->remove = 1;
		re->desc = desc;
		list_add(&re->list, &rename_list);
		dbg_msg("will remove volume %d, name \"%s\"",
			re->desc->vol->vol_id, re->desc->vol->name);
	}

	mutex_lock(&ubi->volumes_mutex);
	err = ubi_rename_volumes(ubi, &rename_list);
	mutex_unlock(&ubi->volumes_mutex);

out_free:
	list_for_each_entry_safe(re, re1, &rename_list, list) {
		ubi_close_volume(re->desc);
		list_del(&re->list);
		kfree(re);
	}
	return err;
}

static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
			  unsigned int cmd, unsigned long arg)
{
	int err = 0;
	struct ubi_device *ubi;
	struct ubi_volume_desc *desc;
	void __user *argp = (void __user *)arg;

	if (!capable(CAP_SYS_RESOURCE))
		return -EPERM;

	ubi = ubi_get_by_major(imajor(inode));
	if (!ubi)
		return -ENODEV;

	switch (cmd) {
	/* Create volume command */
	case UBI_IOCMKVOL:
	{
		struct ubi_mkvol_req req;

		dbg_gen("create volume");
		err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
		if (err) {
			err = -EFAULT;
			break;
		}

		req.name[req.name_len] = '\0';
		err = verify_mkvol_req(ubi, &req);
		if (err)
			break;

		mutex_lock(&ubi->volumes_mutex);
		err = ubi_create_volume(ubi, &req);
		mutex_unlock(&ubi->volumes_mutex);
		if (err)
			break;

		err = put_user(req.vol_id, (__user int32_t *)argp);
		if (err)
			err = -EFAULT;

		break;
	}

	/* Remove volume command */
	case UBI_IOCRMVOL:
	{
		int vol_id;

		dbg_gen("remove volume");
		err = get_user(vol_id, (__user int32_t *)argp);
		if (err) {
			err = -EFAULT;
			break;
		}

		desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
		if (IS_ERR(desc)) {
			err = PTR_ERR(desc);
			break;
		}

		mutex_lock(&ubi->volumes_mutex);
		err = ubi_remove_volume(desc, 0);
		mutex_unlock(&ubi->volumes_mutex);

		/*
		 * The volume is deleted (unless an error occurred), and the
		 * 'struct ubi_volume' object will be freed when
		 * 'ubi_close_volume()' will call 'put_device()'.
		 */
		ubi_close_volume(desc);
		break;
	}

	/* Re-size volume command */
	case UBI_IOCRSVOL:
	{
		int pebs;
		uint64_t tmp;
		struct ubi_rsvol_req req;

		dbg_gen("re-size volume");
		err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
		if (err) {
			err = -EFAULT;
			break;
		}

		err = verify_rsvol_req(ubi, &req);
		if (err)
			break;

		desc = ubi_open_volume(ubi->ubi_num, req.vol_id, UBI_EXCLUSIVE);
		if (IS_ERR(desc)) {
			err = PTR_ERR(desc);
			break;
		}

		tmp = req.bytes;
		pebs = !!do_div(tmp, desc->vol->usable_leb_size);
		pebs += tmp;

		mutex_lock(&ubi->volumes_mutex);
		err = ubi_resize_volume(desc, pebs);
		mutex_unlock(&ubi->volumes_mutex);
		ubi_close_volume(desc);
		break;
	}

	/* Re-name volumes command */
	case UBI_IOCRNVOL:
	{
		struct ubi_rnvol_req *req;

		dbg_msg("re-name volumes");
		req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
		if (!req) {
			err = -ENOMEM;
			break;
		};

		err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
		if (err) {
			err = -EFAULT;
			kfree(req);
			break;
		}

		mutex_lock(&ubi->mult_mutex);
		err = rename_volumes(ubi, req);
		mutex_unlock(&ubi->mult_mutex);
		kfree(req);
		break;
	}

	default:
		err = -ENOTTY;
		break;
	}

	ubi_put_device(ubi);
	return err;
}

static int ctrl_cdev_ioctl(struct inode *inode, struct file *file,
			   unsigned int cmd, unsigned long arg)
{
	int err = 0;
	void __user *argp = (void __user *)arg;

	if (!capable(CAP_SYS_RESOURCE))
		return -EPERM;

	switch (cmd) {
	/* Attach an MTD device command */
	case UBI_IOCATT:
	{
		struct ubi_attach_req req;
		struct mtd_info *mtd;

		dbg_gen("attach MTD device");
		err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
		if (err) {
			err = -EFAULT;
			break;
		}

		if (req.mtd_num < 0 ||
		    (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
			err = -EINVAL;
			break;
		}

		mtd = get_mtd_device(NULL, req.mtd_num);
		if (IS_ERR(mtd)) {
			err = PTR_ERR(mtd);
			break;
		}

		/*
		 * Note, further request verification is done by
		 * 'ubi_attach_mtd_dev()'.
		 */
		mutex_lock(&ubi_devices_mutex);
		err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
		mutex_unlock(&ubi_devices_mutex);
		if (err < 0)
			put_mtd_device(mtd);
		else
			/* @err contains UBI device number */
			err = put_user(err, (__user int32_t *)argp);

		break;
	}

	/* Detach an MTD device command */
	case UBI_IOCDET:
	{
		int ubi_num;

		dbg_gen("dettach MTD device");
		err = get_user(ubi_num, (__user int32_t *)argp);
		if (err) {
			err = -EFAULT;
			break;
		}

		mutex_lock(&ubi_devices_mutex);
		err = ubi_detach_mtd_dev(ubi_num, 0);
		mutex_unlock(&ubi_devices_mutex);
		break;
	}

	default:
		err = -ENOTTY;
		break;
	}

	return err;
}

/* UBI control character device operations */
struct file_operations ubi_ctrl_cdev_operations = {
	.ioctl = ctrl_cdev_ioctl,
	.owner = THIS_MODULE,
};

/* UBI character device operations */
struct file_operations ubi_cdev_operations = {
	.owner = THIS_MODULE,
	.ioctl = ubi_cdev_ioctl,
	.llseek = no_llseek,
};

/* UBI volume character device operations */
struct file_operations ubi_vol_cdev_operations = {
	.owner   = THIS_MODULE,
	.open    = vol_cdev_open,
	.release = vol_cdev_release,
	.llseek  = vol_cdev_llseek,
	.read    = vol_cdev_read,
	.write   = vol_cdev_write,
	.ioctl   = vol_cdev_ioctl,
};