IB/iser: New receive buffer posting logic (bcc60c38) · Commits · e / devices / android_kernel_teracube_2e

drivers/infiniband/ulp/iser/iscsi_iser.c

+1 −1

Original line number	Diff line number	Diff line
		@@ -283,7 +283,7 @@ iscsi_iser_conn_create(struct iscsi_cls_session *cls_session, uint32_t conn_idx)
		* due to issues with the login code re iser sematics
		* this not set in iscsi_conn_setup - FIXME
		*/
		conn->max_recv_dlength = 128;
		conn->max_recv_dlength = ISER_RECV_DATA_SEG_LEN;

		iser_conn = conn->dd_data;
		conn->dd_data = iser_conn;

drivers/infiniband/ulp/iser/iscsi_iser.h

+33 −7

Original line number	Diff line number	Diff line
		@@ -102,9 +102,9 @@
		#define ISER_MAX_TX_MISC_PDUS 6 /* NOOP_OUT(2), TEXT(1), *
		* SCSI_TMFUNC(2), LOGOUT(1) */

		#define ISER_QP_MAX_RECV_DTOS (ISCSI_DEF_XMIT_CMDS_MAX + \
		ISER_MAX_RX_MISC_PDUS + \
		ISER_MAX_TX_MISC_PDUS)
		#define ISER_QP_MAX_RECV_DTOS (ISCSI_DEF_XMIT_CMDS_MAX)

		#define ISER_MIN_POSTED_RX (ISCSI_DEF_XMIT_CMDS_MAX >> 2)

		/* the max TX (send) WR supported by the iSER QP is defined by *
		* max_send_wr = T * (1 + D) + C ; D is how many inflight dataouts we expect *
		@@ -132,6 +132,12 @@ struct iser_hdr {
		__be64 read_va;
		} __attribute__((packed));

		/* Constant PDU lengths calculations */
		#define ISER_HEADERS_LEN (sizeof(struct iser_hdr) + sizeof(struct iscsi_hdr))

		#define ISER_RECV_DATA_SEG_LEN 128
		#define ISER_RX_PAYLOAD_SIZE (ISER_HEADERS_LEN + ISER_RECV_DATA_SEG_LEN)
		#define ISER_RX_LOGIN_SIZE (ISER_HEADERS_LEN + ISCSI_DEF_MAX_RECV_SEG_LEN)

		/* Length of an object name string */
		#define ISER_OBJECT_NAME_SIZE 64
		@@ -212,7 +218,6 @@ struct iser_dto {
		};

		enum iser_desc_type {
		ISCSI_RX,
		ISCSI_TX_CONTROL ,
		ISCSI_TX_SCSI_COMMAND,
		ISCSI_TX_DATAOUT
		@@ -228,6 +233,17 @@ struct iser_desc {
		struct iser_dto dto;
		};

		#define ISER_RX_PAD_SIZE (256 - (ISER_RX_PAYLOAD_SIZE + \
		sizeof(u64) + sizeof(struct ib_sge)))
		struct iser_rx_desc {
		struct iser_hdr iser_header;
		struct iscsi_hdr iscsi_header;
		char data[ISER_RECV_DATA_SEG_LEN];
		u64 dma_addr;
		struct ib_sge rx_sg;
		char pad[ISER_RX_PAD_SIZE];
		} __attribute__((packed));

		struct iser_device {
		struct ib_device *ib_device;
		struct ib_pd *pd;
		@@ -256,6 +272,12 @@ struct iser_conn {
		struct iser_page_vec page_vec; / represents SG to fmr maps*
		* maps serialized as tx is*/
		struct list_head conn_list; /* entry in ig conn list */

		char *login_buf;
		u64 login_dma;
		unsigned int rx_desc_head;
		struct iser_rx_desc *rx_descs;
		struct ib_recv_wr rx_wr[ISER_MIN_POSTED_RX];
		};

		struct iscsi_iser_conn {
		@@ -319,8 +341,9 @@ void iser_conn_put(struct iser_conn *ib_conn);

		void iser_conn_terminate(struct iser_conn *ib_conn);

		void iser_rcv_completion(struct iser_desc *desc,
		unsigned long dto_xfer_len);
		void iser_rcv_completion(struct iser_rx_desc *desc,
		unsigned long dto_xfer_len,
		struct iser_conn *ib_conn);

		void iser_snd_completion(struct iser_desc *desc);

		@@ -332,6 +355,8 @@ void iser_dto_buffs_release(struct iser_dto *dto);

		int iser_regd_buff_release(struct iser_regd_buf *regd_buf);

		void iser_free_rx_descriptors(struct iser_conn *ib_conn);

		void iser_reg_single(struct iser_device *device,
		struct iser_regd_buf *regd_buf,
		enum dma_data_direction direction);
		@@ -353,7 +378,8 @@ int iser_reg_page_vec(struct iser_conn *ib_conn,

		void iser_unreg_mem(struct iser_mem_reg *mem_reg);

		int iser_post_recv(struct iser_desc *rx_desc);
		int iser_post_recvl(struct iser_conn *ib_conn);
		int iser_post_recvm(struct iser_conn *ib_conn, int count);
		int iser_post_send(struct iser_desc *tx_desc);

		int iser_conn_state_comp(struct iser_conn *ib_conn,

drivers/infiniband/ulp/iser/iser_initiator.c

+116 −119

Original line number	Diff line number	Diff line
		@@ -39,9 +39,6 @@

		#include "iscsi_iser.h"

		/* Constant PDU lengths calculations */
		#define ISER_TOTAL_HEADERS_LEN (sizeof (struct iser_hdr) + \
		sizeof (struct iscsi_hdr))

		/* iser_dto_add_regd_buff - increments the reference count for *
		* the registered buffer & adds it to the DTO object */
		@@ -172,78 +169,6 @@ iser_prepare_write_cmd(struct iscsi_task *task,
		return 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 = ISCSI_DEF_MAX_RECV_SEG_LEN;
		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;
		}

		/* creates a new tx descriptor and adds header regd buffer */
		static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
		struct iser_desc *tx_desc)
		@@ -254,7 +179,7 @@ static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
		memset(regd_hdr, 0, sizeof(struct iser_regd_buf));
		regd_hdr->device = iser_conn->ib_conn->device;
		regd_hdr->virt_addr = tx_desc; /* == &tx_desc->iser_header */
		regd_hdr->data_size = ISER_TOTAL_HEADERS_LEN;
		regd_hdr->data_size = ISER_HEADERS_LEN;

		send_dto->ib_conn = iser_conn->ib_conn;
		send_dto->notify_enable = 1;
		@@ -266,6 +191,72 @@ static void iser_create_send_desc(struct iscsi_iser_conn *iser_conn,
		iser_dto_add_regd_buff(send_dto, regd_hdr, 0, 0);
		}

		int iser_alloc_rx_descriptors(struct iser_conn *ib_conn)
		{
		int i, j;
		u64 dma_addr;
		struct iser_rx_desc *rx_desc;
		struct ib_sge *rx_sg;
		struct iser_device *device = ib_conn->device;

		ib_conn->rx_descs = kmalloc(ISER_QP_MAX_RECV_DTOS *
		sizeof(struct iser_rx_desc), GFP_KERNEL);
		if (!ib_conn->rx_descs)
		goto rx_desc_alloc_fail;

		rx_desc = ib_conn->rx_descs;

		for (i = 0; i < ISER_QP_MAX_RECV_DTOS; i++, rx_desc++) {
		dma_addr = ib_dma_map_single(device->ib_device, (void *)rx_desc,
		ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
		if (ib_dma_mapping_error(device->ib_device, dma_addr))
		goto rx_desc_dma_map_failed;

		rx_desc->dma_addr = dma_addr;

		rx_sg = &rx_desc->rx_sg;
		rx_sg->addr = rx_desc->dma_addr;
		rx_sg->length = ISER_RX_PAYLOAD_SIZE;
		rx_sg->lkey = device->mr->lkey;
		}

		ib_conn->rx_desc_head = 0;
		return 0;

		rx_desc_dma_map_failed:
		rx_desc = ib_conn->rx_descs;
		for (j = 0; j < i; j++, rx_desc++)
		ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
		ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
		kfree(ib_conn->rx_descs);
		ib_conn->rx_descs = NULL;
		rx_desc_alloc_fail:
		iser_err("failed allocating rx descriptors / data buffers\n");
		return -ENOMEM;
		}

		void iser_free_rx_descriptors(struct iser_conn *ib_conn)
		{
		int i;
		struct iser_rx_desc *rx_desc;
		struct iser_device *device = ib_conn->device;

		if (ib_conn->login_buf) {
		ib_dma_unmap_single(device->ib_device, ib_conn->login_dma,
		ISER_RX_LOGIN_SIZE, DMA_FROM_DEVICE);
		kfree(ib_conn->login_buf);
		}

		if (!ib_conn->rx_descs)
		return;

		rx_desc = ib_conn->rx_descs;
		for (i = 0; i < ISER_QP_MAX_RECV_DTOS; i++, rx_desc++)
		ib_dma_unmap_single(device->ib_device, rx_desc->dma_addr,
		ISER_RX_PAYLOAD_SIZE, DMA_FROM_DEVICE);
		kfree(ib_conn->rx_descs);
		}

		/**
		* iser_conn_set_full_featured_mode - (iSER API)
		*/
		@@ -273,27 +264,20 @@ int iser_conn_set_full_featured_mode(struct iscsi_conn *conn)
		{
		struct iscsi_iser_conn *iser_conn = conn->dd_data;

		int i;
		/* no need to keep it in a var, we are after login so if this should
		* be negotiated, by now the result should be available here */
		int initial_post_recv_bufs_num = ISER_MAX_RX_MISC_PDUS;

		iser_dbg("Initially post: %d\n", initial_post_recv_bufs_num);
		iser_dbg("Initially post: %d\n", ISER_MIN_POSTED_RX);

		/* Check that there is no posted recv or send buffers left - */
		/* they must be consumed during the login phase */
		BUG_ON(atomic_read(&iser_conn->ib_conn->post_recv_buf_count) != 0);
		BUG_ON(atomic_read(&iser_conn->ib_conn->post_send_buf_count) != 0);

		if (iser_alloc_rx_descriptors(iser_conn->ib_conn))
		return -ENOMEM;

		/* Initial post receive buffers */
		for (i = 0; i < initial_post_recv_bufs_num; i++) {
		if (iser_post_receive_control(conn) != 0) {
		iser_err("Failed to post recv bufs at:%d conn:0x%p\n",
		i, conn);
		if (iser_post_recvm(iser_conn->ib_conn, ISER_MIN_POSTED_RX))
		return -ENOMEM;
		}
		}
		iser_dbg("Posted %d post recv bufs, conn:0x%p\n", i, conn);

		return 0;
		}

		@@ -321,7 +305,7 @@ int iser_send_command(struct iscsi_conn *conn,
		struct iscsi_iser_task *iser_task = task->dd_data;
		struct iser_dto *send_dto = NULL;
		unsigned long edtl;
		int err = 0;
		int err;
		struct iser_data_buf *data_buf;
		struct iscsi_cmd hdr = (struct iscsi_cmd )task->hdr;
		struct scsi_cmnd *sc = task->sc;
		@@ -371,12 +355,6 @@ int iser_send_command(struct iscsi_conn *conn,
		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_task->status = ISER_TASK_STATUS_STARTED;

		err = iser_post_send(&iser_task->desc);
		@@ -474,7 +452,7 @@ int iser_send_control(struct iscsi_conn *conn,
		struct iser_desc *mdesc = &iser_task->desc;
		struct iser_dto *send_dto = NULL;
		unsigned long data_seg_len;
		int err = 0;
		int err;
		struct iser_regd_buf *regd_buf;
		struct iser_device *device;

		@@ -511,9 +489,9 @@ int iser_send_control(struct iscsi_conn *conn,
		data_seg_len);
		}

		if (iser_post_receive_control(conn) != 0) {
		iser_err("post_rcv_buff failed!\n");
		err = -ENOMEM;
		if (task == conn->login_task) {
		err = iser_post_recvl(iser_conn->ib_conn);
		if (err)
		goto send_control_error;
		}

		@@ -530,27 +508,34 @@ int iser_send_control(struct iscsi_conn *conn,
		/**
		* iser_rcv_dto_completion - recv DTO completion
		*/
		void iser_rcv_completion(struct iser_desc *rx_desc,
		unsigned long dto_xfer_len)
		void iser_rcv_completion(struct iser_rx_desc *rx_desc,
		unsigned long rx_xfer_len,
		struct iser_conn *ib_conn)
		{
		struct iser_dto *dto = &rx_desc->dto;
		struct iscsi_iser_conn *conn = dto->ib_conn->iser_conn;
		struct iscsi_iser_conn *conn = 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;
		u64 rx_dma;
		int rx_buflen, outstanding, count, err;

		hdr = &rx_desc->iscsi_header;
		/* differentiate between login to all other PDUs */
		if ((char *)rx_desc == ib_conn->login_buf) {
		rx_dma = ib_conn->login_dma;
		rx_buflen = ISER_RX_LOGIN_SIZE;
		} else {
		rx_dma = rx_desc->dma_addr;
		rx_buflen = ISER_RX_PAYLOAD_SIZE;
		}

		iser_dbg("op 0x%x itt 0x%x\n", hdr->opcode,hdr->itt);
		ib_dma_sync_single_for_cpu(ib_conn->device->ib_device, rx_dma,
		rx_buflen, DMA_FROM_DEVICE);

		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];
		}
		hdr = &rx_desc->iscsi_header;

		iser_dbg("op 0x%x itt 0x%x dlen %d\n", hdr->opcode,
		hdr->itt, (int)(rx_xfer_len - ISER_HEADERS_LEN));

		opcode = hdr->opcode & ISCSI_OPCODE_MASK;

		@@ -573,18 +558,30 @@ void iser_rcv_completion(struct iser_desc *rx_desc,
		iscsi_put_task(task);
		}
		}
		iser_dto_buffs_release(dto);

		iscsi_iser_recv(conn->iscsi_conn, hdr, rx_data, rx_data_len);
		iscsi_iser_recv(conn->iscsi_conn, hdr,
		rx_desc->data, rx_xfer_len - ISER_HEADERS_LEN);

		kfree(rx_desc->data);
		kmem_cache_free(ig.desc_cache, rx_desc);
		ib_dma_sync_single_for_device(ib_conn->device->ib_device, rx_dma,
		rx_buflen, DMA_FROM_DEVICE);

		/* 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 (rx_dma == ib_conn->login_dma)
		return;

		outstanding = atomic_read(&ib_conn->post_recv_buf_count);
		if (outstanding + ISER_MIN_POSTED_RX <= ISER_QP_MAX_RECV_DTOS) {
		count = min(ISER_QP_MAX_RECV_DTOS - outstanding,
		ISER_MIN_POSTED_RX);
		err = iser_post_recvm(ib_conn, count);
		if (err)
		iser_err("posting %d rx bufs err %d\n", count, err);
		}
		}

		void iser_snd_completion(struct iser_desc *tx_desc)

drivers/infiniband/ulp/iser/iser_verbs.c

+85 −49

Original line number	Diff line number	Diff line
		@@ -129,13 +129,23 @@ static int iser_create_ib_conn_res(struct iser_conn *ib_conn)
		{
		struct iser_device *device;
		struct ib_qp_init_attr init_attr;
		int ret;
		int ret = -ENOMEM;
		struct ib_fmr_pool_param params;

		BUG_ON(ib_conn->device == NULL);

		device = ib_conn->device;

		ib_conn->login_buf = kmalloc(ISER_RX_LOGIN_SIZE, GFP_KERNEL);
		if (!ib_conn->login_buf) {
		goto alloc_err;
		ret = -ENOMEM;
		}

		ib_conn->login_dma = ib_dma_map_single(ib_conn->device->ib_device,
		(void *)ib_conn->login_buf, ISER_RX_LOGIN_SIZE,
		DMA_FROM_DEVICE);

		ib_conn->page_vec = kmalloc(sizeof(struct iser_page_vec) +
		(sizeof(u64) * (ISCSI_ISER_SG_TABLESIZE +1)),
		GFP_KERNEL);
		@@ -174,7 +184,7 @@ static int iser_create_ib_conn_res(struct iser_conn *ib_conn)
		init_attr.cap.max_send_wr = ISER_QP_MAX_REQ_DTOS;
		init_attr.cap.max_recv_wr = ISER_QP_MAX_RECV_DTOS;
		init_attr.cap.max_send_sge = MAX_REGD_BUF_VECTOR_LEN;
		init_attr.cap.max_recv_sge = 2;
		init_attr.cap.max_recv_sge = 1;
		init_attr.sq_sig_type = IB_SIGNAL_REQ_WR;
		init_attr.qp_type = IB_QPT_RC;

		@@ -192,6 +202,7 @@ static int iser_create_ib_conn_res(struct iser_conn *ib_conn)
		(void)ib_destroy_fmr_pool(ib_conn->fmr_pool);
		fmr_pool_err:
		kfree(ib_conn->page_vec);
		kfree(ib_conn->login_buf);
		alloc_err:
		iser_err("unable to alloc mem or create resource, err %d\n", ret);
		return ret;
		@@ -314,7 +325,7 @@ static void iser_conn_release(struct iser_conn *ib_conn)
		mutex_lock(&ig.connlist_mutex);
		list_del(&ib_conn->conn_list);
		mutex_unlock(&ig.connlist_mutex);

		iser_free_rx_descriptors(ib_conn);
		iser_free_ib_conn_res(ib_conn);
		ib_conn->device = NULL;
		/* on EVENT_ADDR_ERROR there's no device yet for this conn */
		@@ -625,6 +636,60 @@ void iser_unreg_mem(struct iser_mem_reg *reg)
		reg->mem_h = NULL;
		}

		int iser_post_recvl(struct iser_conn *ib_conn)
		{
		struct ib_recv_wr rx_wr, *rx_wr_failed;
		struct ib_sge sge;
		int ib_ret;

		sge.addr = ib_conn->login_dma;
		sge.length = ISER_RX_LOGIN_SIZE;
		sge.lkey = ib_conn->device->mr->lkey;

		rx_wr.wr_id = (unsigned long)ib_conn->login_buf;
		rx_wr.sg_list = &sge;
		rx_wr.num_sge = 1;
		rx_wr.next = NULL;

		atomic_inc(&ib_conn->post_recv_buf_count);
		ib_ret = ib_post_recv(ib_conn->qp, &rx_wr, &rx_wr_failed);
		if (ib_ret) {
		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
		atomic_dec(&ib_conn->post_recv_buf_count);
		}
		return ib_ret;
		}

		int iser_post_recvm(struct iser_conn *ib_conn, int count)
		{
		struct ib_recv_wr rx_wr, rx_wr_failed;
		int i, ib_ret;
		unsigned int my_rx_head = ib_conn->rx_desc_head;
		struct iser_rx_desc *rx_desc;

		for (rx_wr = ib_conn->rx_wr, i = 0; i < count; i++, rx_wr++) {
		rx_desc = &ib_conn->rx_descs[my_rx_head];
		rx_wr->wr_id = (unsigned long)rx_desc;
		rx_wr->sg_list = &rx_desc->rx_sg;
		rx_wr->num_sge = 1;
		rx_wr->next = rx_wr + 1;
		my_rx_head = (my_rx_head + 1) & (ISER_QP_MAX_RECV_DTOS - 1);
		}

		rx_wr--;
		rx_wr->next = NULL; /* mark end of work requests list */

		atomic_add(count, &ib_conn->post_recv_buf_count);
		ib_ret = ib_post_recv(ib_conn->qp, ib_conn->rx_wr, &rx_wr_failed);
		if (ib_ret) {
		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
		atomic_sub(count, &ib_conn->post_recv_buf_count);
		} else
		ib_conn->rx_desc_head = my_rx_head;
		return ib_ret;
		}


		/**
		* iser_dto_to_iov - builds IOV from a dto descriptor
		*/
		@@ -665,39 +730,6 @@ static void iser_dto_to_iov(struct iser_dto dto, struct ib_sge iov, int iov_le
		}
		}

		/**
		* iser_post_recv - Posts a receive buffer.
		*
		* returns 0 on success, -1 on failure
		*/
		int iser_post_recv(struct iser_desc *rx_desc)
		{
		int ib_ret, ret_val = 0;
		struct ib_recv_wr recv_wr, *recv_wr_failed;
		struct ib_sge iov[2];
		struct iser_conn *ib_conn;
		struct iser_dto *recv_dto = &rx_desc->dto;

		/* Retrieve conn */
		ib_conn = recv_dto->ib_conn;

		iser_dto_to_iov(recv_dto, iov, 2);

		recv_wr.next = NULL;
		recv_wr.sg_list = iov;
		recv_wr.num_sge = recv_dto->regd_vector_len;
		recv_wr.wr_id = (unsigned long)rx_desc;

		atomic_inc(&ib_conn->post_recv_buf_count);
		ib_ret = ib_post_recv(ib_conn->qp, &recv_wr, &recv_wr_failed);
		if (ib_ret) {
		iser_err("ib_post_recv failed ret=%d\n", ib_ret);
		atomic_dec(&ib_conn->post_recv_buf_count);
		ret_val = -1;
		}

		return ret_val;
		}

		/**
		* iser_start_send - Initiate a Send DTO operation
		@@ -737,18 +769,17 @@ int iser_post_send(struct iser_desc *tx_desc)
		return ret_val;
		}

		static void iser_handle_comp_error(struct iser_desc *desc)
		static void iser_handle_comp_error(struct iser_desc *desc,
		struct iser_conn *ib_conn)
		{
		struct iser_dto *dto = &desc->dto;
		struct iser_conn *ib_conn = dto->ib_conn;
		struct iser_rx_desc rx = (struct iser_rx_desc )desc;
		struct iser_rx_desc *rx_first = ib_conn->rx_descs;
		struct iser_rx_desc *rx_last = rx_first + (ISER_QP_MAX_RECV_DTOS - 1);

		iser_dto_buffs_release(dto);

		if (desc->type == ISCSI_RX) {
		kfree(desc->data);
		kmem_cache_free(ig.desc_cache, desc);
		if ((char *)desc == ib_conn->login_buf \|\|
		(rx_first <= rx && rx <= rx_last))
		atomic_dec(&ib_conn->post_recv_buf_count);
		} else { /* type is TX control/command/dataout */
		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);
		@@ -780,20 +811,25 @@ static void iser_cq_tasklet_fn(unsigned long data)
		struct ib_wc wc;
		struct iser_desc *desc;
		unsigned long xfer_len;
		struct iser_conn *ib_conn;

		while (ib_poll_cq(cq, 1, &wc) == 1) {
		desc = (struct iser_desc *) (unsigned long) wc.wr_id;
		BUG_ON(desc == NULL);
		ib_conn = wc.qp->qp_context;

		if (wc.status == IB_WC_SUCCESS) {
		if (desc->type == ISCSI_RX) {
		if (wc.opcode == IB_WC_RECV) {
		xfer_len = (unsigned long)wc.byte_len;
		iser_rcv_completion(desc, xfer_len);
		iser_rcv_completion((struct iser_rx_desc *)desc,
		xfer_len, ib_conn);
		} else /* type == ISCSI_TX_CONTROL/SCSI_CMD/DOUT */
		iser_snd_completion(desc);
		} else {
		iser_err("comp w. error op %d status %d\n",desc->type,wc.status);
		iser_handle_comp_error(desc);
		if (wc.status != IB_WC_WR_FLUSH_ERR)
		iser_err("id %llx status %d vend_err %x\n",
		wc.wr_id, wc.status, wc.vendor_err);
		iser_handle_comp_error(desc, ib_conn);
		}
		}
		/* #warning "it is assumed here that arming CQ only once its empty" *