Example #1
0
static void iser_handle_comp_error(struct iser_desc *desc)
{
	struct iser_dto  *dto     = &desc->dto;
	struct iser_conn *ib_conn = dto->ib_conn;

	iser_dto_buffs_release(dto);

	if (desc->type == ISCSI_RX) {
		kfree(desc->data);
		kmem_cache_free(ig.desc_cache, desc);
		atomic_dec(&ib_conn->post_recv_buf_count);
	} else { 
		if (desc->type == ISCSI_TX_DATAOUT)
			kmem_cache_free(ig.desc_cache, desc);
		atomic_dec(&ib_conn->post_send_buf_count);
	}

	if (atomic_read(&ib_conn->post_recv_buf_count) == 0 &&
	    atomic_read(&ib_conn->post_send_buf_count) == 0) {
		
		if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
		    ISER_CONN_TERMINATING))
			iscsi_conn_failure(ib_conn->iser_conn->iscsi_conn,
					   ISCSI_ERR_CONN_FAILED);

		
		if (ib_conn->disc_evt_flag) {
			ib_conn->state = ISER_CONN_DOWN;
			wake_up_interruptible(&ib_conn->wait);
		}
	}
}
Example #2
0
void iser_snd_completion(struct iser_desc *tx_desc)
{
	struct iser_dto        *dto = &tx_desc->dto;
	struct iser_conn       *ib_conn = dto->ib_conn;
	struct iscsi_iser_conn *iser_conn = ib_conn->iser_conn;
	struct iscsi_conn      *conn = iser_conn->iscsi_conn;
	struct iscsi_task *task;
	int resume_tx = 0;

	iser_dbg("Initiator, Data sent dto=0x%p\n", dto);

	iser_dto_buffs_release(dto);

	if (tx_desc->type == ISCSI_TX_DATAOUT)
		kmem_cache_free(ig.desc_cache, tx_desc);

	if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
	    ISER_QP_MAX_REQ_DTOS)
		resume_tx = 1;

	atomic_dec(&ib_conn->post_send_buf_count);

	if (resume_tx) {
		iser_dbg("%ld resuming tx\n",jiffies);
		scsi_queue_work(conn->session->host, &conn->xmitwork);
	}

	if (tx_desc->type == ISCSI_TX_CONTROL) {
		/* this arithmetic is legal by libiscsi dd_data allocation */
		task = (void *) ((long)(void *)tx_desc -
				  sizeof(struct iscsi_task));
		if (task->hdr->itt == RESERVED_ITT)
			iscsi_put_task(task);
	}
}
Example #3
0
static void iser_handle_comp_error(struct iser_desc *desc)
{
	struct iser_dto  *dto     = &desc->dto;
	struct iser_conn *ib_conn = dto->ib_conn;

	iser_dto_buffs_release(dto);

	if (desc->type == ISCSI_RX) {
		kfree(desc->data);
		kmem_cache_free(ig.desc_cache, desc);
		atomic_dec(&ib_conn->post_recv_buf_count);
	} else { /* type is TX control/command/dataout */
		if (desc->type == ISCSI_TX_DATAOUT)
			kmem_cache_free(ig.desc_cache, desc);
		atomic_dec(&ib_conn->post_send_buf_count);
	}

	if (atomic_read(&ib_conn->post_recv_buf_count) == 0 &&
	    atomic_read(&ib_conn->post_send_buf_count) == 0) {
		/* getting here when the state is UP means that the conn is *
		 * being terminated asynchronously from the iSCSI layer's   *
		 * perspective.                                             */
		if (iser_conn_state_comp_exch(ib_conn, ISER_CONN_UP,
		    ISER_CONN_TERMINATING))
			iscsi2_conn_failure(ib_conn->iser_conn->iscsi_conn,
					   ISCSI_ERR_CONN_FAILED);

		/* complete the termination process if disconnect event was delivered *
		 * note there are no more non completed posts to the QP               */
		if (ib_conn->disc_evt_flag) {
			ib_conn->state = ISER_CONN_DOWN;
			wake_up_interruptible(&ib_conn->wait);
		}
	}
}
Example #4
0
int iser_send_control(struct iscsi_conn *conn,
		      struct iscsi_mgmt_task *mtask)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iser_desc *mdesc = mtask->dd_data;
	struct iser_dto *send_dto = NULL;
	unsigned long data_seg_len;
	int err = 0;
	struct iser_regd_buf *regd_buf;
	struct iser_device *device;

	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
		return -EPERM;
	}

	if (iser_check_xmit(conn,mtask))
		return -ENOBUFS;

	/* build the tx desc regd header and add it to the tx desc dto */
	mdesc->type = ISCSI_TX_CONTROL;
	send_dto = &mdesc->dto;
	send_dto->ctask = NULL;
	iser_create_send_desc(iser_conn, mdesc);

	device = iser_conn->ib_conn->device;

	iser_reg_single(device, send_dto->regd[0], DMA_TO_DEVICE);

	data_seg_len = ntoh24(mtask->hdr->dlength);

	if (data_seg_len > 0) {
		regd_buf = &mdesc->data_regd_buf;
		memset(regd_buf, 0, sizeof(struct iser_regd_buf));
		regd_buf->device = device;
		regd_buf->virt_addr = mtask->data;
		regd_buf->data_size = mtask->data_count;
		iser_reg_single(device, regd_buf,
				DMA_TO_DEVICE);
		iser_dto_add_regd_buff(send_dto, regd_buf,
				       0,
				       data_seg_len);
	}

	if (iser_post_receive_control(conn) != 0) {
		iser_err("post_rcv_buff failed!\n");
		err = -ENOMEM;
		goto send_control_error;
	}

	err = iser_post_send(mdesc);
	if (!err)
		return 0;

send_control_error:
	iser_dto_buffs_release(send_dto);
	iser_err("conn %p failed err %d\n",conn, err);
	return err;
}
Example #5
0
/**
 * iser_rcv_dto_completion - recv DTO completion
 */
void iser_rcv_completion(struct iser_desc *rx_desc,
			 unsigned long dto_xfer_len)
{
	struct iser_dto        *dto = &rx_desc->dto;
	struct iscsi_iser_conn *conn = dto->ib_conn->iser_conn;
	struct iscsi_session *session = conn->iscsi_conn->session;
	struct iscsi_cmd_task *ctask;
	struct iscsi_iser_cmd_task *iser_ctask;
	struct iscsi_hdr *hdr;
	char   *rx_data = NULL;
	int     rx_data_len = 0;
	unsigned int itt;
	unsigned char opcode;

	hdr = &rx_desc->iscsi_header;

	iser_dbg("op 0x%x itt 0x%x\n", hdr->opcode,hdr->itt);

	if (dto_xfer_len > ISER_TOTAL_HEADERS_LEN) { /* we have data */
		rx_data_len = dto_xfer_len - ISER_TOTAL_HEADERS_LEN;
		rx_data     = dto->regd[1]->virt_addr;
		rx_data    += dto->offset[1];
	}

	opcode = hdr->opcode & ISCSI_OPCODE_MASK;

	if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
	        itt = hdr->itt & ISCSI_ITT_MASK; /* mask out cid and age bits */
		if (!(itt < session->cmds_max))
			iser_err("itt can't be matched to task!!!"
				 "conn %p opcode %d cmds_max %d itt %d\n",
				 conn->iscsi_conn,opcode,session->cmds_max,itt);
		/* use the mapping given with the cmds array indexed by itt */
		ctask = (struct iscsi_cmd_task *)session->cmds[itt];
		iser_ctask = ctask->dd_data;
		iser_dbg("itt %d ctask %p\n",itt,ctask);
		iser_ctask->status = ISER_TASK_STATUS_COMPLETED;
		iser_ctask_rdma_finalize(iser_ctask);
	}

	iser_dto_buffs_release(dto);

	iscsi_iser_recv(conn->iscsi_conn, hdr, rx_data, rx_data_len);

	kfree(rx_desc->data);
	kmem_cache_free(ig.desc_cache, rx_desc);

	/* decrementing conn->post_recv_buf_count only --after-- freeing the   *
	 * task eliminates the need to worry on tasks which are completed in   *
	 * parallel to the execution of iser_conn_term. So the code that waits *
	 * for the posted rx bufs refcount to become zero handles everything   */
	atomic_dec(&conn->ib_conn->post_recv_buf_count);
}
Example #6
0
void iser_snd_completion(struct iser_desc *tx_desc)
{
	struct iser_dto        *dto = &tx_desc->dto;
	struct iser_conn       *ib_conn = dto->ib_conn;
	struct iscsi_iser_conn *iser_conn = ib_conn->iser_conn;
	struct iscsi_conn      *conn = iser_conn->iscsi_conn;
	struct iscsi_mgmt_task *mtask;
	int resume_tx = 0;

	iser_dbg("Initiator, Data sent dto=0x%p\n", dto);

	iser_dto_buffs_release(dto);

	if (tx_desc->type == ISCSI_TX_DATAOUT)
		kmem_cache_free(ig.desc_cache, tx_desc);

	if (atomic_read(&iser_conn->ib_conn->post_send_buf_count) ==
	    ISER_QP_MAX_REQ_DTOS)
		resume_tx = 1;

	atomic_dec(&ib_conn->post_send_buf_count);

	if (resume_tx) {
		iser_dbg("%ld resuming tx\n",jiffies);
		scsi_queue_work(conn->session->host, &conn->xmitwork);
	}

	if (tx_desc->type == ISCSI_TX_CONTROL) {
		/* this arithmetic is legal by libiscsi dd_data allocation */
		mtask = (void *) ((long)(void *)tx_desc -
				  sizeof(struct iscsi_mgmt_task));
		if (mtask->hdr->itt == cpu_to_be32(ISCSI_RESERVED_TAG)) {
			struct iscsi_session *session = conn->session;

			spin_lock(&conn->session->lock);
			list_del(&mtask->running);
			__kfifo_put(session->mgmtpool.queue, (void*)&mtask,
				    sizeof(void*));
			spin_unlock(&session->lock);
		}
	}
}
Example #7
0
/**
 * iser_send_data_out - send data out PDU
 */
int iser_send_data_out(struct iscsi_conn     *conn,
		       struct iscsi_cmd_task *ctask,
		       struct iscsi_data *hdr)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
	struct iser_desc *tx_desc = NULL;
	struct iser_dto *send_dto = NULL;
	unsigned long buf_offset;
	unsigned long data_seg_len;
	unsigned int itt;
	int err = 0;

	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
		return -EPERM;
	}

	if (iser_check_xmit(conn, ctask))
		return -ENOBUFS;

	itt = ntohl(hdr->itt);
	data_seg_len = ntoh24(hdr->dlength);
	buf_offset   = ntohl(hdr->offset);

	iser_dbg("%s itt %d dseg_len %d offset %d\n",
		 __func__,(int)itt,(int)data_seg_len,(int)buf_offset);

	tx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
	if (tx_desc == NULL) {
		iser_err("Failed to alloc desc for post dataout\n");
		return -ENOMEM;
	}

	tx_desc->type = ISCSI_TX_DATAOUT;
	memcpy(&tx_desc->iscsi_header, hdr, sizeof(struct iscsi_hdr));

	/* build the tx desc regd header and add it to the tx desc dto */
	send_dto = &tx_desc->dto;
	send_dto->ctask = iser_ctask;
	iser_create_send_desc(iser_conn, tx_desc);

	iser_reg_single(iser_conn->ib_conn->device,
			send_dto->regd[0], DMA_TO_DEVICE);

	/* all data was registered for RDMA, we can use the lkey */
	iser_dto_add_regd_buff(send_dto,
			       &iser_ctask->rdma_regd[ISER_DIR_OUT],
			       buf_offset,
			       data_seg_len);

	if (buf_offset + data_seg_len > iser_ctask->data[ISER_DIR_OUT].data_len) {
		iser_err("Offset:%ld & DSL:%ld in Data-Out "
			 "inconsistent with total len:%ld, itt:%d\n",
			 buf_offset, data_seg_len,
			 iser_ctask->data[ISER_DIR_OUT].data_len, itt);
		err = -EINVAL;
		goto send_data_out_error;
	}
	iser_dbg("data-out itt: %d, offset: %ld, sz: %ld\n",
		 itt, buf_offset, data_seg_len);


	err = iser_post_send(tx_desc);
	if (!err)
		return 0;

send_data_out_error:
	iser_dto_buffs_release(send_dto);
	kmem_cache_free(ig.desc_cache, tx_desc);
	iser_err("conn %p failed err %d\n",conn, err);
	return err;
}
Example #8
0
/**
 * iser_send_command - send command PDU
 */
int iser_send_command(struct iscsi_conn     *conn,
		      struct iscsi_cmd_task *ctask)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iscsi_iser_cmd_task *iser_ctask = ctask->dd_data;
	struct iser_dto *send_dto = NULL;
	unsigned long edtl;
	int err = 0;
	struct iser_data_buf *data_buf;

	struct iscsi_cmd *hdr =  ctask->hdr;
	struct scsi_cmnd *sc  =  ctask->sc;

	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
		return -EPERM;
	}
	if (iser_check_xmit(conn, ctask))
		return -ENOBUFS;

	edtl = ntohl(hdr->data_length);

	/* build the tx desc regd header and add it to the tx desc dto */
	iser_ctask->desc.type = ISCSI_TX_SCSI_COMMAND;
	send_dto = &iser_ctask->desc.dto;
	send_dto->ctask = iser_ctask;
	iser_create_send_desc(iser_conn, &iser_ctask->desc);

	if (hdr->flags & ISCSI_FLAG_CMD_READ)
		data_buf = &iser_ctask->data[ISER_DIR_IN];
	else
		data_buf = &iser_ctask->data[ISER_DIR_OUT];

	if (sc->use_sg) { /* using a scatter list */
		data_buf->buf  = sc->request_buffer;
		data_buf->size = sc->use_sg;
	} else if (sc->request_bufflen) {
		/* using a single buffer - convert it into one entry SG */
		sg_init_one(&data_buf->sg_single,
			    sc->request_buffer, sc->request_bufflen);
		data_buf->buf   = &data_buf->sg_single;
		data_buf->size  = 1;
	}

	data_buf->data_len = sc->request_bufflen;

	if (hdr->flags & ISCSI_FLAG_CMD_READ) {
		err = iser_prepare_read_cmd(ctask, edtl);
		if (err)
			goto send_command_error;
	}
	if (hdr->flags & ISCSI_FLAG_CMD_WRITE) {
		err = iser_prepare_write_cmd(ctask,
					     ctask->imm_count,
				             ctask->imm_count +
					     ctask->unsol_count,
					     edtl);
		if (err)
			goto send_command_error;
	}

	iser_reg_single(iser_conn->ib_conn->device,
			send_dto->regd[0], DMA_TO_DEVICE);

	if (iser_post_receive_control(conn) != 0) {
		iser_err("post_recv failed!\n");
		err = -ENOMEM;
		goto send_command_error;
	}

	iser_ctask->status = ISER_TASK_STATUS_STARTED;

	err = iser_post_send(&iser_ctask->desc);
	if (!err)
		return 0;

send_command_error:
	iser_dto_buffs_release(send_dto);
	iser_err("conn %p failed ctask->itt %d err %d\n",conn, ctask->itt, err);
	return err;
}
Example #9
0
/**
 * iser_post_receive_control - allocates, initializes and posts receive DTO.
 */
static int iser_post_receive_control(struct iscsi_conn *conn)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iser_desc     *rx_desc;
	struct iser_regd_buf *regd_hdr;
	struct iser_regd_buf *regd_data;
	struct iser_dto      *recv_dto = NULL;
	struct iser_device  *device = iser_conn->ib_conn->device;
	int rx_data_size, err = 0;

	rx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
	if (rx_desc == NULL) {
		iser_err("Failed to alloc desc for post recv\n");
		return -ENOMEM;
	}
	rx_desc->type = ISCSI_RX;

	/* for the login sequence we must support rx of upto 8K; login is done
	 * after conn create/bind (connect) and conn stop/bind (reconnect),
	 * what's common for both schemes is that the connection is not started
	 */
	if (conn->c_stage != ISCSI_CONN_STARTED)
		rx_data_size = DEFAULT_MAX_RECV_DATA_SEGMENT_LENGTH;
	else /* FIXME till user space sets conn->max_recv_dlength correctly */
		rx_data_size = 128;

	rx_desc->data = kmalloc(rx_data_size, GFP_NOIO);
	if (rx_desc->data == NULL) {
		iser_err("Failed to alloc data buf for post recv\n");
		err = -ENOMEM;
		goto post_rx_kmalloc_failure;
	}

	recv_dto = &rx_desc->dto;
	recv_dto->ib_conn = iser_conn->ib_conn;
	recv_dto->regd_vector_len = 0;

	regd_hdr = &rx_desc->hdr_regd_buf;
	memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
	regd_hdr->device  = device;
	regd_hdr->virt_addr  = rx_desc; /* == &rx_desc->iser_header */
	regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;

	iser_reg_single(device, regd_hdr, DMA_FROM_DEVICE);

	iser_dto_add_regd_buff(recv_dto, regd_hdr, 0, 0);

	regd_data = &rx_desc->data_regd_buf;
	memset(regd_data, 0, sizeof(struct iser_regd_buf));
	regd_data->device  = device;
	regd_data->virt_addr  = rx_desc->data;
	regd_data->data_size  = rx_data_size;

	iser_reg_single(device, regd_data, DMA_FROM_DEVICE);

	iser_dto_add_regd_buff(recv_dto, regd_data, 0, 0);

	err = iser_post_recv(rx_desc);
	if (!err)
		return 0;

	/* iser_post_recv failed */
	iser_dto_buffs_release(recv_dto);
	kfree(rx_desc->data);
post_rx_kmalloc_failure:
	kmem_cache_free(ig.desc_cache, rx_desc);
	return err;
}
Example #10
0
/**
 * iser_rcv_dto_completion - recv DTO completion
 */
void iser_rcv_completion(struct iser_desc *rx_desc,
			 unsigned long dto_xfer_len)
{
	struct iser_dto *dto = &rx_desc->dto;
	struct iscsi_iser_conn *conn = dto->ib_conn->iser_conn;
	struct iscsi_task *task;
	struct iscsi_iser_task *iser_task;
	struct iscsi_hdr *hdr;
	char   *rx_data = NULL;
	int     rx_data_len = 0;
	unsigned char opcode;

	hdr = &rx_desc->iscsi_header;

	iser_dbg("op 0x%x itt 0x%x\n", hdr->opcode,hdr->itt);

	if (dto_xfer_len > ISER_TOTAL_HEADERS_LEN) { /* we have data */
		rx_data_len = dto_xfer_len - ISER_TOTAL_HEADERS_LEN;
		rx_data     = dto->regd[1]->virt_addr;
		rx_data    += dto->offset[1];
	}

	opcode = hdr->opcode & ISCSI_OPCODE_MASK;

	if (opcode == ISCSI_OP_SCSI_CMD_RSP) {
		spin_lock(&conn->iscsi_conn->session->lock);
		task = iscsi_itt_to_ctask(conn->iscsi_conn, hdr->itt);
		if (task)
			__iscsi_get_task(task);
		spin_unlock(&conn->iscsi_conn->session->lock);

		if (!task)
			iser_err("itt can't be matched to task!!! "
				 "conn %p opcode %d itt %d\n",
				 conn->iscsi_conn, opcode, hdr->itt);
		else {
			iser_task = task->dd_data;
			iser_dbg("itt %d task %p\n",hdr->itt, task);
			iser_task->status = ISER_TASK_STATUS_COMPLETED;
			iser_task_rdma_finalize(iser_task);
			iscsi_put_task(task);
		}
	}
	iser_dto_buffs_release(dto);

	iscsi_iser_recv(conn->iscsi_conn, hdr, rx_data, rx_data_len);

	kfree(rx_desc->data);
	kmem_cache_free(ig.desc_cache, rx_desc);

	/* decrementing conn->post_recv_buf_count only --after-- freeing the   *
	 * task eliminates the need to worry on tasks which are completed in   *
	 * parallel to the execution of iser_conn_term. So the code that waits *
	 * for the posted rx bufs refcount to become zero handles everything   */
	atomic_dec(&conn->ib_conn->post_recv_buf_count);

	/*
	 * if an unexpected PDU was received then the recv wr consumed must
	 * be replaced, this is done in the next send of a control-type PDU
	 */
	if (opcode == ISCSI_OP_NOOP_IN && hdr->itt == RESERVED_ITT) {
		/* nop-in with itt = 0xffffffff */
		atomic_inc(&conn->ib_conn->unexpected_pdu_count);
	}
	else if (opcode == ISCSI_OP_ASYNC_EVENT) {
		/* asyncronous message */
		atomic_inc(&conn->ib_conn->unexpected_pdu_count);
	}
	/* a reject PDU consumes the recv buf posted for the response */
}
Example #11
0
int iser_send_control(struct iscsi_conn *conn,
		      struct iscsi_task *task)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iscsi_iser_task *iser_task = task->dd_data;
	struct iser_desc *mdesc = &iser_task->desc;
	struct iser_dto *send_dto = NULL;
	unsigned long data_seg_len;
	int err = 0;
	struct iser_regd_buf *regd_buf;
	struct iser_device *device;
	unsigned char opcode;

	if (!iser_conn_state_comp(iser_conn->ib_conn, ISER_CONN_UP)) {
		iser_err("Failed to send, conn: 0x%p is not up\n", iser_conn->ib_conn);
		return -EPERM;
	}

	if (iser_check_xmit(conn, task))
		return -ENOBUFS;

	/* build the tx desc regd header and add it to the tx desc dto */
	mdesc->type = ISCSI_TX_CONTROL;
	send_dto = &mdesc->dto;
	send_dto->task = NULL;
	iser_create_send_desc(iser_conn, mdesc);

	device = iser_conn->ib_conn->device;

	iser_reg_single(device, send_dto->regd[0], DMA_TO_DEVICE);

	data_seg_len = ntoh24(task->hdr->dlength);

	if (data_seg_len > 0) {
		regd_buf = &mdesc->data_regd_buf;
		memset(regd_buf, 0, sizeof(struct iser_regd_buf));
		regd_buf->device = device;
		regd_buf->virt_addr = task->data;
		regd_buf->data_size = task->data_count;
		iser_reg_single(device, regd_buf,
				DMA_TO_DEVICE);
		iser_dto_add_regd_buff(send_dto, regd_buf,
				       0,
				       data_seg_len);
	}

	opcode = task->hdr->opcode & ISCSI_OPCODE_MASK;

	/* post recv buffer for response if one is expected */
	if (!(opcode == ISCSI_OP_NOOP_OUT && task->hdr->itt == RESERVED_ITT)) {
		if (iser_post_receive_control(conn) != 0) {
			iser_err("post_rcv_buff failed!\n");
			err = -ENOMEM;
			goto send_control_error;
		}
	}

	err = iser_post_send(mdesc);
	if (!err)
		return 0;

send_control_error:
	iser_dto_buffs_release(send_dto);
	iser_err("conn %p failed err %d\n",conn, err);
	return err;
}
Example #12
0
/**
 * iser_post_receive_control - allocates, initializes and posts receive DTO.
 */
static int iser_post_receive_control(struct iscsi_conn *conn)
{
	struct iscsi_iser_conn *iser_conn = conn->dd_data;
	struct iser_desc     *rx_desc;
	struct iser_regd_buf *regd_hdr;
	struct iser_regd_buf *regd_data;
	struct iser_dto      *recv_dto = NULL;
	struct iser_device  *device = iser_conn->ib_conn->device;
	int rx_data_size, err;
	int posts, outstanding_unexp_pdus;

	/* for the login sequence we must support rx of upto 8K; login is done
	 * after conn create/bind (connect) and conn stop/bind (reconnect),
	 * what's common for both schemes is that the connection is not started
	 */
	if (conn->c_stage != ISCSI_CONN_STARTED)
		rx_data_size = ISCSI_DEF_MAX_RECV_SEG_LEN;
	else /* FIXME till user space sets conn->max_recv_dlength correctly */
		rx_data_size = 128;

	outstanding_unexp_pdus =
		atomic_xchg(&iser_conn->ib_conn->unexpected_pdu_count, 0);

	/*
	 * in addition to the response buffer, replace those consumed by
	 * unexpected pdus.
	 */
	for (posts = 0; posts < 1 + outstanding_unexp_pdus; posts++) {
		rx_desc = kmem_cache_alloc(ig.desc_cache, GFP_NOIO);
		if (rx_desc == NULL) {
			iser_err("Failed to alloc desc for post recv %d\n",
				 posts);
			err = -ENOMEM;
			goto post_rx_cache_alloc_failure;
		}
		rx_desc->type = ISCSI_RX;
		rx_desc->data = kmalloc(rx_data_size, GFP_NOIO);
		if (rx_desc->data == NULL) {
			iser_err("Failed to alloc data buf for post recv %d\n",
				 posts);
			err = -ENOMEM;
			goto post_rx_kmalloc_failure;
		}

		recv_dto = &rx_desc->dto;
		recv_dto->ib_conn = iser_conn->ib_conn;
		recv_dto->regd_vector_len = 0;

		regd_hdr = &rx_desc->hdr_regd_buf;
		memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
		regd_hdr->device  = device;
		regd_hdr->virt_addr  = rx_desc; /* == &rx_desc->iser_header */
		regd_hdr->data_size  = ISER_TOTAL_HEADERS_LEN;

		iser_reg_single(device, regd_hdr, DMA_FROM_DEVICE);

		iser_dto_add_regd_buff(recv_dto, regd_hdr, 0, 0);

		regd_data = &rx_desc->data_regd_buf;
		memset(regd_data, 0, sizeof(struct iser_regd_buf));
		regd_data->device  = device;
		regd_data->virt_addr  = rx_desc->data;
		regd_data->data_size  = rx_data_size;

		iser_reg_single(device, regd_data, DMA_FROM_DEVICE);

		iser_dto_add_regd_buff(recv_dto, regd_data, 0, 0);

		err = iser_post_recv(rx_desc);
		if (err) {
			iser_err("Failed iser_post_recv for post %d\n", posts);
			goto post_rx_post_recv_failure;
		}
	}
	/* all posts successful */
	return 0;

post_rx_post_recv_failure:
	iser_dto_buffs_release(recv_dto);
	kfree(rx_desc->data);
post_rx_kmalloc_failure:
	kmem_cache_free(ig.desc_cache, rx_desc);
post_rx_cache_alloc_failure:
	if (posts > 0) {
		/*
		 * response buffer posted, but did not replace all unexpected
		 * pdu recv bufs. Ignore error, retry occurs next send
		 */
		outstanding_unexp_pdus -= (posts - 1);
		err = 0;
	}
	atomic_add(outstanding_unexp_pdus,
		   &iser_conn->ib_conn->unexpected_pdu_count);

	return err;
}