int drbd_adm_disk_opts()

in drbd/drbd_nl.c [1565:1700]

• 108 lines of code
• 22 McCabe index (conditional complexity)

int drbd_adm_disk_opts(struct sk_buff *skb, struct genl_info *info)
{
	struct drbd_config_context adm_ctx;
	enum drbd_ret_code retcode;
	struct drbd_device *device;
	struct disk_conf *new_disk_conf, *old_disk_conf;
	struct fifo_buffer *old_plan = NULL, *new_plan = NULL;
	int err;
	unsigned int fifo_size;

	retcode = drbd_adm_prepare(&adm_ctx, skb, info, DRBD_ADM_NEED_MINOR);
	if (!adm_ctx.reply_skb)
		return retcode;
	if (retcode != NO_ERROR)
		goto finish;

	device = adm_ctx.device;
	mutex_lock(&adm_ctx.resource->adm_mutex);

	/* we also need a disk
	 * to change the options on */
	if (!get_ldev(device)) {
		retcode = ERR_NO_DISK;
		goto out;
	}

	new_disk_conf = kmalloc(sizeof(struct disk_conf), GFP_KERNEL);
	if (!new_disk_conf) {
		retcode = ERR_NOMEM;
		goto fail;
	}

	mutex_lock(&device->resource->conf_update);
	old_disk_conf = device->ldev->disk_conf;
	*new_disk_conf = *old_disk_conf;
	if (should_set_defaults(info))
		set_disk_conf_defaults(new_disk_conf);

	err = disk_conf_from_attrs_for_change(new_disk_conf, info);
	if (err && err != -ENOMSG) {
		retcode = ERR_MANDATORY_TAG;
		drbd_msg_put_info(adm_ctx.reply_skb, from_attrs_err_to_txt(err));
		goto fail_unlock;
	}

	if (!expect(new_disk_conf->resync_rate >= 1))
		new_disk_conf->resync_rate = 1;

	sanitize_disk_conf(device, new_disk_conf, device->ldev);

	if (new_disk_conf->c_plan_ahead > DRBD_C_PLAN_AHEAD_MAX)
		new_disk_conf->c_plan_ahead = DRBD_C_PLAN_AHEAD_MAX;

	fifo_size = (new_disk_conf->c_plan_ahead * 10 * SLEEP_TIME) / HZ;
	if (fifo_size != device->rs_plan_s->size) {
		new_plan = fifo_alloc(fifo_size);
		if (!new_plan) {
			drbd_err(device, "kmalloc of fifo_buffer failed");
			retcode = ERR_NOMEM;
			goto fail_unlock;
		}
	}

	err = disk_opts_check_al_size(device, new_disk_conf);
	if (err) {
		/* Could be just "busy". Ignore?
		 * Introduce dedicated error code? */
		drbd_msg_put_info(adm_ctx.reply_skb,
			"Try again without changing current al-extents setting");
		retcode = ERR_NOMEM;
		goto fail_unlock;
	}

	lock_all_resources();
	retcode = drbd_resync_after_valid(device, new_disk_conf->resync_after);
	if (retcode == NO_ERROR) {
		rcu_assign_pointer(device->ldev->disk_conf, new_disk_conf);
		drbd_resync_after_changed(device);
	}
	unlock_all_resources();

	if (retcode != NO_ERROR)
		goto fail_unlock;

	if (new_plan) {
		old_plan = device->rs_plan_s;
		rcu_assign_pointer(device->rs_plan_s, new_plan);
	}

	mutex_unlock(&device->resource->conf_update);

	if (new_disk_conf->al_updates)
		device->ldev->md.flags &= ~MDF_AL_DISABLED;
	else
		device->ldev->md.flags |= MDF_AL_DISABLED;

	if (new_disk_conf->md_flushes)
		clear_bit(MD_NO_FUA, &device->flags);
	else
		set_bit(MD_NO_FUA, &device->flags);

	if (write_ordering_changed(old_disk_conf, new_disk_conf))
		drbd_bump_write_ordering(device->resource, NULL, WO_BDEV_FLUSH);

	if (old_disk_conf->discard_zeroes_if_aligned != new_disk_conf->discard_zeroes_if_aligned
	||  old_disk_conf->disable_write_same != new_disk_conf->disable_write_same)
		drbd_reconsider_queue_parameters(device, device->ldev, NULL);

	drbd_md_sync(device);

	if (device->state.conn >= C_CONNECTED) {
		struct drbd_peer_device *peer_device;

		for_each_peer_device(peer_device, device)
			drbd_send_sync_param(peer_device);
	}

	synchronize_rcu();
	kfree(old_disk_conf);
	kfree(old_plan);
	mod_timer(&device->request_timer, jiffies + HZ);
	goto success;

fail_unlock:
	mutex_unlock(&device->resource->conf_update);
 fail:
	kfree(new_disk_conf);
	kfree(new_plan);
success:
	put_ldev(device);
 out:
	mutex_unlock(&adm_ctx.resource->adm_mutex);
 finish:
	drbd_adm_finish(&adm_ctx, info, retcode);
	return 0;
}