static ssize_t nvme_fc_nvme_discovery_store()

in host/fc.c [3776:3834]

• 42 lines of code
• 6 McCabe index (conditional complexity)

static ssize_t nvme_fc_nvme_discovery_store(struct device *dev,
		struct device_attribute *attr, const char *buf, size_t count)
{
	unsigned long flags;
	LIST_HEAD(local_disc_list);
	struct nvme_fc_lport *lport;
	struct nvme_fc_rport *rport;
	int failcnt = 0;

	spin_lock_irqsave(&nvme_fc_lock, flags);
restart:
	list_for_each_entry(lport, &nvme_fc_lport_list, port_list) {
		list_for_each_entry(rport, &lport->endp_list, endp_list) {
			if (!nvme_fc_lport_get(lport))
				continue;
			if (!nvme_fc_rport_get(rport)) {
				/*
				 * This is a temporary condition. Upon restart
				 * this rport will be gone from the list.
				 *
				 * Revert the lport put and retry.  Anything
				 * added to the list already will be skipped (as
				 * they are no longer list_empty).  Loops should
				 * resume at rports that were not yet seen.
				 */
				nvme_fc_lport_put(lport);

				if (failcnt++ < DISCOVERY_MAX_FAIL)
					goto restart;

				pr_err("nvme_discovery: too many reference "
				       "failures\n");
				goto process_local_list;
			}
			if (list_empty(&rport->disc_list))
				list_add_tail(&rport->disc_list,
					      &local_disc_list);
		}
	}

process_local_list:
	while (!list_empty(&local_disc_list)) {
		rport = list_first_entry(&local_disc_list,
					 struct nvme_fc_rport, disc_list);
		list_del_init(&rport->disc_list);
		spin_unlock_irqrestore(&nvme_fc_lock, flags);

		lport = rport->lport;
		/* signal discovery. Won't hurt if it repeats */
		nvme_fc_signal_discovery_scan(lport, rport);
		nvme_fc_rport_put(rport);
		nvme_fc_lport_put(lport);

		spin_lock_irqsave(&nvme_fc_lock, flags);
	}
	spin_unlock_irqrestore(&nvme_fc_lock, flags);

	return count;
}