libiscsi.c

linux 内核源代码

	if (session->leadconn == conn) {
		/*
		 * leading connection? then give up on recovery.
		 */
		session->state = ISCSI_STATE_TERMINATE;
		wake_up(&conn->ehwait);
	}
	spin_unlock_bh(&session->lock);

	/*
	 * Block until all in-progress commands for this connection
	 * time out or fail.
	 */
	for (;;) {
		spin_lock_irqsave(session->host->host_lock, flags);
		if (!session->host->host_busy) { /* OK for ERL == 0 */
			spin_unlock_irqrestore(session->host->host_lock, flags);
			break;
		}
		spin_unlock_irqrestore(session->host->host_lock, flags);
		msleep_interruptible(500);
		printk(KERN_INFO "iscsi: scsi conn_destroy(): host_busy %d "
		       "host_failed %d\n", session->host->host_busy,
		       session->host->host_failed);
		/*
		 * force eh_abort() to unblock
		 */
		wake_up(&conn->ehwait);
	}

	/* flush queued up work because we free the connection below */
	scsi_flush_work(session->host);

	spin_lock_bh(&session->lock);
	kfree(conn->data);
	kfree(conn->persistent_address);
	__kfifo_put(session->mgmtpool.queue, (void*)&conn->login_mtask,
		    sizeof(void*));
	if (session->leadconn == conn)
		session->leadconn = NULL;
	spin_unlock_bh(&session->lock);

	kfifo_free(conn->mgmtqueue);

	iscsi_destroy_conn(cls_conn);
}
EXPORT_SYMBOL_GPL(iscsi_conn_teardown);

int iscsi_conn_start(struct iscsi_cls_conn *cls_conn)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_session *session = conn->session;

	if (!session) {
		printk(KERN_ERR "iscsi: can't start unbound connection\n");
		return -EPERM;
	}

	if ((session->imm_data_en || !session->initial_r2t_en) &&
	     session->first_burst > session->max_burst) {
		printk("iscsi: invalid burst lengths: "
		       "first_burst %d max_burst %d\n",
		       session->first_burst, session->max_burst);
		return -EINVAL;
	}

	spin_lock_bh(&session->lock);
	conn->c_stage = ISCSI_CONN_STARTED;
	session->state = ISCSI_STATE_LOGGED_IN;
	session->queued_cmdsn = session->cmdsn;

	switch(conn->stop_stage) {
	case STOP_CONN_RECOVER:
		/*
		 * unblock eh_abort() if it is blocked. re-try all
		 * commands after successful recovery
		 */
		conn->stop_stage = 0;
		conn->tmabort_state = TMABORT_INITIAL;
		session->age++;
		spin_unlock_bh(&session->lock);

		iscsi_unblock_session(session_to_cls(session));
		wake_up(&conn->ehwait);
		return 0;
	case STOP_CONN_TERM:
		conn->stop_stage = 0;
		break;
	default:
		break;
	}
	spin_unlock_bh(&session->lock);

	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_conn_start);

static void
flush_control_queues(struct iscsi_session *session, struct iscsi_conn *conn)
{
	struct iscsi_mgmt_task *mtask, *tmp;

	/* handle pending */
	while (__kfifo_get(conn->mgmtqueue, (void*)&mtask, sizeof(void*))) {
		if (mtask == conn->login_mtask)
			continue;
		debug_scsi("flushing pending mgmt task itt 0x%x\n", mtask->itt);
		__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
			    sizeof(void*));
	}

	/* handle running */
	list_for_each_entry_safe(mtask, tmp, &conn->mgmt_run_list, running) {
		debug_scsi("flushing running mgmt task itt 0x%x\n", mtask->itt);
		list_del(&mtask->running);

		if (mtask == conn->login_mtask)
			continue;
		__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
			   sizeof(void*));
	}

	conn->mtask = NULL;
}

/* Fail commands. Mutex and session lock held and recv side suspended */
static void fail_all_commands(struct iscsi_conn *conn)
{
	struct iscsi_cmd_task *ctask, *tmp;

	/* flush pending */
	list_for_each_entry_safe(ctask, tmp, &conn->xmitqueue, running) {
		debug_scsi("failing pending sc %p itt 0x%x\n", ctask->sc,
			   ctask->itt);
		fail_command(conn, ctask, DID_BUS_BUSY << 16);
	}

	/* fail all other running */
	list_for_each_entry_safe(ctask, tmp, &conn->run_list, running) {
		debug_scsi("failing in progress sc %p itt 0x%x\n",
			   ctask->sc, ctask->itt);
		fail_command(conn, ctask, DID_BUS_BUSY << 16);
	}

	conn->ctask = NULL;
}

static void iscsi_start_session_recovery(struct iscsi_session *session,
					 struct iscsi_conn *conn, int flag)
{
	int old_stop_stage;

	mutex_lock(&session->eh_mutex);
	spin_lock_bh(&session->lock);
	if (conn->stop_stage == STOP_CONN_TERM) {
		spin_unlock_bh(&session->lock);
		mutex_unlock(&session->eh_mutex);
		return;
	}

	/*
	 * The LLD either freed/unset the lock on us, or userspace called
	 * stop but did not create a proper connection (connection was never
	 * bound or it was unbound then stop was called).
	 */
	if (!conn->recv_lock) {
		spin_unlock_bh(&session->lock);
		mutex_unlock(&session->eh_mutex);
		return;
	}

	/*
	 * When this is called for the in_login state, we only want to clean
	 * up the login task and connection. We do not need to block and set
	 * the recovery state again
	 */
	if (flag == STOP_CONN_TERM)
		session->state = ISCSI_STATE_TERMINATE;
	else if (conn->stop_stage != STOP_CONN_RECOVER)
		session->state = ISCSI_STATE_IN_RECOVERY;

	old_stop_stage = conn->stop_stage;
	conn->stop_stage = flag;
	conn->c_stage = ISCSI_CONN_STOPPED;
	spin_unlock_bh(&session->lock);

	iscsi_suspend_tx(conn);

	write_lock_bh(conn->recv_lock);
	set_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
	write_unlock_bh(conn->recv_lock);

	/*
	 * for connection level recovery we should not calculate
	 * header digest. conn->hdr_size used for optimization
	 * in hdr_extract() and will be re-negotiated at
	 * set_param() time.
	 */
	if (flag == STOP_CONN_RECOVER) {
		conn->hdrdgst_en = 0;
		conn->datadgst_en = 0;
		if (session->state == ISCSI_STATE_IN_RECOVERY &&
		    old_stop_stage != STOP_CONN_RECOVER) {
			debug_scsi("blocking session\n");
			iscsi_block_session(session_to_cls(session));
		}
	}

	/*
	 * flush queues.
	 */
	spin_lock_bh(&session->lock);
	fail_all_commands(conn);
	flush_control_queues(session, conn);
	spin_unlock_bh(&session->lock);
	mutex_unlock(&session->eh_mutex);
}

void iscsi_conn_stop(struct iscsi_cls_conn *cls_conn, int flag)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_session *session = conn->session;

	switch (flag) {
	case STOP_CONN_RECOVER:
	case STOP_CONN_TERM:
		iscsi_start_session_recovery(session, conn, flag);
		break;
	default:
		printk(KERN_ERR "iscsi: invalid stop flag %d\n", flag);
	}
}
EXPORT_SYMBOL_GPL(iscsi_conn_stop);

int iscsi_conn_bind(struct iscsi_cls_session *cls_session,
		    struct iscsi_cls_conn *cls_conn, int is_leading)
{
	struct iscsi_session *session = class_to_transport_session(cls_session);
	struct iscsi_conn *conn = cls_conn->dd_data;

	spin_lock_bh(&session->lock);
	if (is_leading)
		session->leadconn = conn;
	spin_unlock_bh(&session->lock);

	/*
	 * Unblock xmitworker(), Login Phase will pass through.
	 */
	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_rx);
	clear_bit(ISCSI_SUSPEND_BIT, &conn->suspend_tx);
	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_conn_bind);


int iscsi_set_param(struct iscsi_cls_conn *cls_conn,
		    enum iscsi_param param, char *buf, int buflen)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	struct iscsi_session *session = conn->session;
	uint32_t value;

	switch(param) {
	case ISCSI_PARAM_MAX_RECV_DLENGTH:
		sscanf(buf, "%d", &conn->max_recv_dlength);
		break;
	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
		sscanf(buf, "%d", &conn->max_xmit_dlength);
		break;
	case ISCSI_PARAM_HDRDGST_EN:
		sscanf(buf, "%d", &conn->hdrdgst_en);
		break;
	case ISCSI_PARAM_DATADGST_EN:
		sscanf(buf, "%d", &conn->datadgst_en);
		break;
	case ISCSI_PARAM_INITIAL_R2T_EN:
		sscanf(buf, "%d", &session->initial_r2t_en);
		break;
	case ISCSI_PARAM_MAX_R2T:
		sscanf(buf, "%d", &session->max_r2t);
		break;
	case ISCSI_PARAM_IMM_DATA_EN:
		sscanf(buf, "%d", &session->imm_data_en);
		break;
	case ISCSI_PARAM_FIRST_BURST:
		sscanf(buf, "%d", &session->first_burst);
		break;
	case ISCSI_PARAM_MAX_BURST:
		sscanf(buf, "%d", &session->max_burst);
		break;
	case ISCSI_PARAM_PDU_INORDER_EN:
		sscanf(buf, "%d", &session->pdu_inorder_en);
		break;
	case ISCSI_PARAM_DATASEQ_INORDER_EN:
		sscanf(buf, "%d", &session->dataseq_inorder_en);
		break;
	case ISCSI_PARAM_ERL:
		sscanf(buf, "%d", &session->erl);
		break;
	case ISCSI_PARAM_IFMARKER_EN:
		sscanf(buf, "%d", &value);
		BUG_ON(value);
		break;
	case ISCSI_PARAM_OFMARKER_EN:
		sscanf(buf, "%d", &value);
		BUG_ON(value);
		break;
	case ISCSI_PARAM_EXP_STATSN:
		sscanf(buf, "%u", &conn->exp_statsn);
		break;
	case ISCSI_PARAM_USERNAME:
		kfree(session->username);
		session->username = kstrdup(buf, GFP_KERNEL);
		if (!session->username)
			return -ENOMEM;
		break;
	case ISCSI_PARAM_USERNAME_IN:
		kfree(session->username_in);
		session->username_in = kstrdup(buf, GFP_KERNEL);
		if (!session->username_in)
			return -ENOMEM;
		break;
	case ISCSI_PARAM_PASSWORD:
		kfree(session->password);
		session->password = kstrdup(buf, GFP_KERNEL);
		if (!session->password)
			return -ENOMEM;
		break;
	case ISCSI_PARAM_PASSWORD_IN:
		kfree(session->password_in);
		session->password_in = kstrdup(buf, GFP_KERNEL);
		if (!session->password_in)
			return -ENOMEM;
		break;
	case ISCSI_PARAM_TARGET_NAME:
		/* this should not change between logins */
		if (session->targetname)
			break;

		session->targetname = kstrdup(buf, GFP_KERNEL);
		if (!session->targetname)
			return -ENOMEM;
		break;
	case ISCSI_PARAM_TPGT:
		sscanf(buf, "%d", &session->tpgt);
		break;
	case ISCSI_PARAM_PERSISTENT_PORT:
		sscanf(buf, "%d", &conn->persistent_port);
		break;
	case ISCSI_PARAM_PERSISTENT_ADDRESS:
		/*
		 * this is the address returned in discovery so it should
		 * not change between logins.
		 */
		if (conn->persistent_address)
			break;

		conn->persistent_address = kstrdup(buf, GFP_KERNEL);
		if (!conn->persistent_address)
			return -ENOMEM;
		break;
	default:
		return -ENOSYS;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_set_param);

int iscsi_session_get_param(struct iscsi_cls_session *cls_session,
			    enum iscsi_param param, char *buf)
{
	struct Scsi_Host *shost = iscsi_session_to_shost(cls_session);
	struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
	int len;

	switch(param) {
	case ISCSI_PARAM_INITIAL_R2T_EN:
		len = sprintf(buf, "%d\n", session->initial_r2t_en);
		break;
	case ISCSI_PARAM_MAX_R2T:
		len = sprintf(buf, "%hu\n", session->max_r2t);
		break;
	case ISCSI_PARAM_IMM_DATA_EN:
		len = sprintf(buf, "%d\n", session->imm_data_en);
		break;
	case ISCSI_PARAM_FIRST_BURST:
		len = sprintf(buf, "%u\n", session->first_burst);
		break;
	case ISCSI_PARAM_MAX_BURST:
		len = sprintf(buf, "%u\n", session->max_burst);
		break;
	case ISCSI_PARAM_PDU_INORDER_EN:
		len = sprintf(buf, "%d\n", session->pdu_inorder_en);
		break;
	case ISCSI_PARAM_DATASEQ_INORDER_EN:
		len = sprintf(buf, "%d\n", session->dataseq_inorder_en);
		break;
	case ISCSI_PARAM_ERL:
		len = sprintf(buf, "%d\n", session->erl);
		break;
	case ISCSI_PARAM_TARGET_NAME:
		len = sprintf(buf, "%s\n", session->targetname);
		break;
	case ISCSI_PARAM_TPGT:
		len = sprintf(buf, "%d\n", session->tpgt);
		break;
	case ISCSI_PARAM_USERNAME:
		len = sprintf(buf, "%s\n", session->username);
		break;
	case ISCSI_PARAM_USERNAME_IN:
		len = sprintf(buf, "%s\n", session->username_in);
		break;
	case ISCSI_PARAM_PASSWORD:
		len = sprintf(buf, "%s\n", session->password);
		break;
	case ISCSI_PARAM_PASSWORD_IN:
		len = sprintf(buf, "%s\n", session->password_in);
		break;
	default:
		return -ENOSYS;
	}

	return len;
}
EXPORT_SYMBOL_GPL(iscsi_session_get_param);

int iscsi_conn_get_param(struct iscsi_cls_conn *cls_conn,
			 enum iscsi_param param, char *buf)
{
	struct iscsi_conn *conn = cls_conn->dd_data;
	int len;

	switch(param) {
	case ISCSI_PARAM_MAX_RECV_DLENGTH:
		len = sprintf(buf, "%u\n", conn->max_recv_dlength);
		break;
	case ISCSI_PARAM_MAX_XMIT_DLENGTH:
		len = sprintf(buf, "%u\n", conn->max_xmit_dlength);
		break;
	case ISCSI_PARAM_HDRDGST_EN:
		len = sprintf(buf, "%d\n", conn->hdrdgst_en);
		break;
	case ISCSI_PARAM_DATADGST_EN:
		len = sprintf(buf, "%d\n", conn->datadgst_en);
		break;
	case ISCSI_PARAM_IFMARKER_EN:
		len = sprintf(buf, "%d\n", conn->ifmarker_en);
		break;
	case ISCSI_PARAM_OFMARKER_EN:
		len = sprintf(buf, "%d\n", conn->ofmarker_en);
		break;
	case ISCSI_PARAM_EXP_STATSN:
		len = sprintf(buf, "%u\n", conn->exp_statsn);
		break;
	case ISCSI_PARAM_PERSISTENT_PORT:
		len = sprintf(buf, "%d\n", conn->persistent_port);
		break;
	case ISCSI_PARAM_PERSISTENT_ADDRESS:
		len = sprintf(buf, "%s\n", conn->persistent_address);
		break;
	default:
		return -ENOSYS;
	}

	return len;
}
EXPORT_SYMBOL_GPL(iscsi_conn_get_param);

int iscsi_host_get_param(struct Scsi_Host *shost, enum iscsi_host_param param,
			 char *buf)
{
	struct iscsi_session *session = iscsi_hostdata(shost->hostdata);
	int len;

	switch (param) {
	case ISCSI_HOST_PARAM_NETDEV_NAME:
		if (!session->netdev)
			len = sprintf(buf, "%s\n", "default");
		else
			len = sprintf(buf, "%s\n", session->netdev);
		break;
	case ISCSI_HOST_PARAM_HWADDRESS:
		if (!session->hwaddress)
			len = sprintf(buf, "%s\n", "default");
		else
			len = sprintf(buf, "%s\n", session->hwaddress);
		break;
	case ISCSI_HOST_PARAM_INITIATOR_NAME:
		if (!session->initiatorname)
			len = sprintf(buf, "%s\n", "unknown");
		else
			len = sprintf(buf, "%s\n", session->initiatorname);
		break;

	default:
		return -ENOSYS;
	}

	return len;
}
EXPORT_SYMBOL_GPL(iscsi_host_get_param);

int iscsi_host_set_param(struct Scsi_Host *shost, enum iscsi_host_param param,
			 char *buf, int buflen)
{
	struct iscsi_session *session = iscsi_hostdata(shost->hostdata);

	switch (param) {
	case ISCSI_HOST_PARAM_NETDEV_NAME:
		if (!session->netdev)
			session->netdev = kstrdup(buf, GFP_KERNEL);
		break;
	case ISCSI_HOST_PARAM_HWADDRESS:
		if (!session->hwaddress)
			session->hwaddress = kstrdup(buf, GFP_KERNEL);
		break;
	case ISCSI_HOST_PARAM_INITIATOR_NAME:
		if (!session->initiatorname)
			session->initiatorname = kstrdup(buf, GFP_KERNEL);
		break;
	default:
		return -ENOSYS;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(iscsi_host_set_param);

MODULE_AUTHOR("Mike Christie");
MODULE_DESCRIPTION("iSCSI library functions");
MODULE_LICENSE("GPL");