void ldom_set_var()

in kernel/ds.c [744:841]

• 85 lines of code
• 14 McCabe index (conditional complexity)

void ldom_set_var(const char *var, const char *value)
{
	struct ds_cap_state *cp;
	struct ds_info *dp;
	unsigned long flags;

	spin_lock_irqsave(&ds_lock, flags);
	cp = NULL;
	for (dp = ds_info_list; dp; dp = dp->next) {
		struct ds_cap_state *tmp;

		tmp = find_cap_by_string(dp, "var-config");
		if (tmp && tmp->state == CAP_STATE_REGISTERED) {
			cp = tmp;
			break;
		}
	}
	if (!cp) {
		for (dp = ds_info_list; dp; dp = dp->next) {
			struct ds_cap_state *tmp;

			tmp = find_cap_by_string(dp, "var-config-backup");
			if (tmp && tmp->state == CAP_STATE_REGISTERED) {
				cp = tmp;
				break;
			}
		}
	}
	spin_unlock_irqrestore(&ds_lock, flags);

	if (cp) {
		union {
			struct {
				struct ds_data		data;
				struct ds_var_set_msg	msg;
			} header;
			char			all[512];
		} pkt;
		char  *base, *p;
		int msg_len, loops;

		if (strlen(var) + strlen(value) + 2 >
		    sizeof(pkt) - sizeof(pkt.header)) {
			printk(KERN_ERR PFX
				"contents length: %zu, which more than max: %lu,"
				"so could not set (%s) variable to (%s).\n",
				strlen(var) + strlen(value) + 2,
				sizeof(pkt) - sizeof(pkt.header), var, value);
			return;
		}

		memset(&pkt, 0, sizeof(pkt));
		pkt.header.data.tag.type = DS_DATA;
		pkt.header.data.handle = cp->handle;
		pkt.header.msg.hdr.type = DS_VAR_SET_REQ;
		base = p = &pkt.header.msg.name_and_value[0];
		strcpy(p, var);
		p += strlen(var) + 1;
		strcpy(p, value);
		p += strlen(value) + 1;

		msg_len = (sizeof(struct ds_data) +
			   sizeof(struct ds_var_set_msg) +
			   (p - base));
		msg_len = (msg_len + 3) & ~3;
		pkt.header.data.tag.len = msg_len - sizeof(struct ds_msg_tag);

		mutex_lock(&ds_var_mutex);

		spin_lock_irqsave(&ds_lock, flags);
		ds_var_doorbell = 0;
		ds_var_response = -1;

		__ds_send(dp->lp, &pkt, msg_len);
		spin_unlock_irqrestore(&ds_lock, flags);

		loops = 1000;
		while (ds_var_doorbell == 0) {
			if (loops-- < 0)
				break;
			barrier();
			udelay(100);
		}

		mutex_unlock(&ds_var_mutex);

		if (ds_var_doorbell == 0 ||
		    ds_var_response != DS_VAR_SUCCESS)
			printk(KERN_ERR "ds-%llu: var-config [%s:%s] "
			       "failed, response(%d).\n",
			       dp->id, var, value,
			       ds_var_response);
	} else {
		printk(KERN_ERR PFX "var-config not registered so "
		       "could not set (%s) variable to (%s).\n",
		       var, value);
	}
}