IB/isert: Support T10-PI protected transactions

In case the Target core passed transport T10 protection
operation:

1. Register data buffer (data memory region)
2. Register protection buffer if exsists (prot memory region)
3. Register signature region (signature memory region)
   - use work request IB_WR_REG_SIG_MR
4. Execute RDMA
5. Upon RDMA completion check the signature status
   - if succeeded send good SCSI response
   - if failed send SCSI bad response with appropriate sense buffer

(Fix up compile error in isert_reg_sig_mr, and fix up incorrect
 se_cmd->prot_type -> TARGET_PROT_NORMAL comparision - nab)
(Fix failed sector assignment in isert_completion_rdma_* - Sagi + nab)
(Fix enum assignements for protection type - Sagi)
(Fix devision on 32-bit in isert_completion_rdma_* - Sagi + Fengguang)
(Fix context change for v3.14-rc6 code - nab)
(Fix iscsit_build_rsp_pdu inc_statsn flag usage - nab)

Signed-off-by: Sagi Grimberg <sagig@mellanox.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

2 files changed, 311 insertions, 29 deletions

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index 2eb07b943ed9..f82fe3dccabe 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -1552,6 +1552,10 @@ isert_unreg_rdma(struct isert_cmd *isert_cmd, struct isert_conn *isert_conn)
         if (wr->fr_desc) {
                 pr_debug("unreg_fastreg_cmd: %p free fr_desc %p\n",
                          isert_cmd, wr->fr_desc);
+                if (wr->fr_desc->ind & ISERT_PROTECTED) {
+                        isert_unmap_data_buf(isert_conn, &wr->prot);
+                        wr->fr_desc->ind &= ~ISERT_PROTECTED;
+                }
                 spin_lock_bh(&isert_conn->conn_lock);
                 list_add_tail(&wr->fr_desc->list, &isert_conn->conn_fr_pool);
                 spin_unlock_bh(&isert_conn->conn_lock);
@@ -1657,12 +1661,55 @@ static void
 isert_completion_rdma_write(struct iser_tx_desc *tx_desc,
                             struct isert_cmd *isert_cmd)
 {
+        struct isert_rdma_wr *wr = &isert_cmd->rdma_wr;
         struct iscsi_cmd *cmd = isert_cmd->iscsi_cmd;
+        struct se_cmd *se_cmd = &cmd->se_cmd;
         struct isert_conn *isert_conn = isert_cmd->conn;
         struct isert_device *device = isert_conn->conn_device;
+        struct ib_mr_status mr_status;
+        int ret = 0;
+
+        if (wr->fr_desc && wr->fr_desc->ind & ISERT_PROTECTED) {
+                ret = ib_check_mr_status(wr->fr_desc->pi_ctx->sig_mr,
+                                         IB_MR_CHECK_SIG_STATUS, &mr_status);
+                if (ret) {
+                        pr_err("ib_check_mr_status failed, ret %d\n", ret);
+                        goto fail_mr_status;
+                }
+                if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
+                        u32 block_size = se_cmd->se_dev->dev_attrib.block_size + 8;
+
+                        switch (mr_status.sig_err.err_type) {
+                        case IB_SIG_BAD_GUARD:
+                                se_cmd->pi_err = TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
+                                break;
+                        case IB_SIG_BAD_REFTAG:
+                                se_cmd->pi_err = TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
+                                break;
+                        case IB_SIG_BAD_APPTAG:
+                                se_cmd->pi_err = TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED;
+                                break;
+                        }
+                        se_cmd->bad_sector = mr_status.sig_err.sig_err_offset;
+                        do_div(se_cmd->bad_sector, block_size);
+
+                        pr_err("isert: PI error found type %d at sector 0x%llx "
+                               "expected 0x%x vs actual 0x%x\n",
+                               mr_status.sig_err.err_type,
+                               (unsigned long long)se_cmd->bad_sector,
+                               mr_status.sig_err.expected,
+                               mr_status.sig_err.actual);
+                        ret = 1;
+                }
+        }
 
+fail_mr_status:
         device->unreg_rdma_mem(isert_cmd, isert_conn);
-        isert_put_response(isert_conn->conn, cmd);
+        if (ret)
+                transport_send_check_condition_and_sense(se_cmd,
+                                                         se_cmd->pi_err, 0);
+        else
+                isert_put_response(isert_conn->conn, cmd);
 }
 
 static void
@@ -1674,7 +1721,43 @@ isert_completion_rdma_read(struct iser_tx_desc *tx_desc,
         struct se_cmd *se_cmd = &cmd->se_cmd;
         struct isert_conn *isert_conn = isert_cmd->conn;
         struct isert_device *device = isert_conn->conn_device;
+        struct ib_mr_status mr_status;
+        int ret;
 
+        if (wr->fr_desc && wr->fr_desc->ind & ISERT_PROTECTED) {
+                ret = ib_check_mr_status(wr->fr_desc->pi_ctx->sig_mr,
+                                         IB_MR_CHECK_SIG_STATUS, &mr_status);
+                if (ret) {
+                        pr_err("ib_check_mr_status failed, ret %d\n", ret);
+                        goto fail_mr_status;
+                }
+                if (mr_status.fail_status & IB_MR_CHECK_SIG_STATUS) {
+                        u32 block_size = se_cmd->se_dev->dev_attrib.block_size + 8;
+
+                        switch (mr_status.sig_err.err_type) {
+                        case IB_SIG_BAD_GUARD:
+                                se_cmd->pi_err = TCM_LOGICAL_BLOCK_GUARD_CHECK_FAILED;
+                                break;
+                        case IB_SIG_BAD_REFTAG:
+                                se_cmd->pi_err = TCM_LOGICAL_BLOCK_REF_TAG_CHECK_FAILED;
+                                break;
+                        case IB_SIG_BAD_APPTAG:
+                                se_cmd->pi_err = TCM_LOGICAL_BLOCK_APP_TAG_CHECK_FAILED;
+                                break;
+                        }
+                        se_cmd->bad_sector = mr_status.sig_err.sig_err_offset;
+                        do_div(se_cmd->bad_sector, block_size);
+
+                        pr_err("isert: PI error found type %d at sector 0x%llx "
+                               "expected 0x%x vs actual 0x%x\n",
+                               mr_status.sig_err.err_type,
+                               (unsigned long long)se_cmd->bad_sector,
+                               mr_status.sig_err.expected,
+                               mr_status.sig_err.actual);
+                }
+        }
+
+fail_mr_status:
         iscsit_stop_dataout_timer(cmd);
         device->unreg_rdma_mem(isert_cmd, isert_conn);
         cmd->write_data_done = wr->data.len;
@@ -2349,9 +2432,12 @@ static int
 isert_fast_reg_mr(struct isert_conn *isert_conn,
                   struct fast_reg_descriptor *fr_desc,
                   struct isert_data_buf *mem,
+                  enum isert_indicator ind,
                   struct ib_sge *sge)
 {
         struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+        struct ib_mr *mr;
+        struct ib_fast_reg_page_list *frpl;
         struct ib_send_wr fr_wr, inv_wr;
         struct ib_send_wr *bad_wr, *wr = NULL;
         int ret, pagelist_len;
@@ -2362,39 +2448,51 @@ isert_fast_reg_mr(struct isert_conn *isert_conn,
                 sge->lkey = isert_conn->conn_mr->lkey;
                 sge->addr = ib_sg_dma_address(ib_dev, &mem->sg[0]);
                 sge->length = ib_sg_dma_len(ib_dev, &mem->sg[0]);
+                pr_debug("%s:%d sge: addr: 0x%llx  length: %u lkey: %x\n",
+                         __func__, __LINE__, sge->addr, sge->length,
+                         sge->lkey);
                 return 0;
         }
 
+        if (ind == ISERT_DATA_KEY_VALID) {
+                /* Registering data buffer */
+                mr = fr_desc->data_mr;
+                frpl = fr_desc->data_frpl;
+        } else {
+                /* Registering protection buffer */
+                mr = fr_desc->pi_ctx->prot_mr;
+                frpl = fr_desc->pi_ctx->prot_frpl;
+        }
+
         page_off = mem->offset % PAGE_SIZE;
 
         pr_debug("Use fr_desc %p sg_nents %d offset %u\n",
                  fr_desc, mem->nents, mem->offset);
 
         pagelist_len = isert_map_fr_pagelist(ib_dev, mem->sg, mem->nents,
-                                             &fr_desc->data_frpl->page_list[0]);
+                                             &frpl->page_list[0]);
 
         if (!(fr_desc->ind & ISERT_DATA_KEY_VALID)) {
                 memset(&inv_wr, 0, sizeof(inv_wr));
                 inv_wr.wr_id = ISER_FASTREG_LI_WRID;
                 inv_wr.opcode = IB_WR_LOCAL_INV;
-                inv_wr.ex.invalidate_rkey = fr_desc->data_mr->rkey;
+                inv_wr.ex.invalidate_rkey = mr->rkey;
                 wr = &inv_wr;
                 /* Bump the key */
-                key = (u8)(fr_desc->data_mr->rkey & 0x000000FF);
-                ib_update_fast_reg_key(fr_desc->data_mr, ++key);
+                key = (u8)(mr->rkey & 0x000000FF);
+                ib_update_fast_reg_key(mr, ++key);
         }
 
         /* Prepare FASTREG WR */
         memset(&fr_wr, 0, sizeof(fr_wr));
         fr_wr.wr_id = ISER_FASTREG_LI_WRID;
         fr_wr.opcode = IB_WR_FAST_REG_MR;
-        fr_wr.wr.fast_reg.iova_start =
-                fr_desc->data_frpl->page_list[0] + page_off;
-        fr_wr.wr.fast_reg.page_list = fr_desc->data_frpl;
+        fr_wr.wr.fast_reg.iova_start = frpl->page_list[0] + page_off;
+        fr_wr.wr.fast_reg.page_list = frpl;
         fr_wr.wr.fast_reg.page_list_len = pagelist_len;
         fr_wr.wr.fast_reg.page_shift = PAGE_SHIFT;
         fr_wr.wr.fast_reg.length = mem->len;
-        fr_wr.wr.fast_reg.rkey = fr_desc->data_mr->rkey;
+        fr_wr.wr.fast_reg.rkey = mr->rkey;
         fr_wr.wr.fast_reg.access_flags = IB_ACCESS_LOCAL_WRITE;
 
         if (!wr)
@@ -2407,18 +2505,158 @@ isert_fast_reg_mr(struct isert_conn *isert_conn,
                 pr_err("fast registration failed, ret:%d\n", ret);
                 return ret;
         }
-        fr_desc->ind &= ~ISERT_DATA_KEY_VALID;
+        fr_desc->ind &= ~ind;
 
-        sge->lkey = fr_desc->data_mr->lkey;
-        sge->addr = fr_desc->data_frpl->page_list[0] + page_off;
+        sge->lkey = mr->lkey;
+        sge->addr = frpl->page_list[0] + page_off;
         sge->length = mem->len;
 
-        pr_debug("RDMA ib_sge: addr: 0x%16llx  length: %u lkey: %08x\n",
-                 sge->addr, sge->length, sge->lkey);
+        pr_debug("%s:%d sge: addr: 0x%llx  length: %u lkey: %x\n",
+                 __func__, __LINE__, sge->addr, sge->length,
+                 sge->lkey);
 
         return ret;
 }
 
+static inline enum ib_t10_dif_type
+se2ib_prot_type(enum target_prot_type prot_type)
+{
+        switch (prot_type) {
+        case TARGET_DIF_TYPE0_PROT:
+                return IB_T10DIF_NONE;
+        case TARGET_DIF_TYPE1_PROT:
+                return IB_T10DIF_TYPE1;
+        case TARGET_DIF_TYPE2_PROT:
+                return IB_T10DIF_TYPE2;
+        case TARGET_DIF_TYPE3_PROT:
+                return IB_T10DIF_TYPE3;
+        default:
+                return IB_T10DIF_NONE;
+        }
+}
+
+static int
+isert_set_sig_attrs(struct se_cmd *se_cmd, struct ib_sig_attrs *sig_attrs)
+{
+        enum ib_t10_dif_type ib_prot_type = se2ib_prot_type(se_cmd->prot_type);
+
+        sig_attrs->mem.sig_type = IB_SIG_TYPE_T10_DIF;
+        sig_attrs->wire.sig_type = IB_SIG_TYPE_T10_DIF;
+        sig_attrs->mem.sig.dif.pi_interval =
+                                se_cmd->se_dev->dev_attrib.block_size;
+        sig_attrs->wire.sig.dif.pi_interval =
+                                se_cmd->se_dev->dev_attrib.block_size;
+
+        switch (se_cmd->prot_op) {
+        case TARGET_PROT_DIN_INSERT:
+        case TARGET_PROT_DOUT_STRIP:
+                sig_attrs->mem.sig.dif.type = IB_T10DIF_NONE;
+                sig_attrs->wire.sig.dif.type = ib_prot_type;
+                sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
+                sig_attrs->wire.sig.dif.ref_tag = se_cmd->reftag_seed;
+                break;
+        case TARGET_PROT_DOUT_INSERT:
+        case TARGET_PROT_DIN_STRIP:
+                sig_attrs->mem.sig.dif.type = ib_prot_type;
+                sig_attrs->mem.sig.dif.bg_type = IB_T10DIF_CRC;
+                sig_attrs->mem.sig.dif.ref_tag = se_cmd->reftag_seed;
+                sig_attrs->wire.sig.dif.type = IB_T10DIF_NONE;
+                break;
+        case TARGET_PROT_DIN_PASS:
+        case TARGET_PROT_DOUT_PASS:
+                sig_attrs->mem.sig.dif.type = ib_prot_type;
+                sig_attrs->mem.sig.dif.bg_type = IB_T10DIF_CRC;
+                sig_attrs->mem.sig.dif.ref_tag = se_cmd->reftag_seed;
+                sig_attrs->wire.sig.dif.type = ib_prot_type;
+                sig_attrs->wire.sig.dif.bg_type = IB_T10DIF_CRC;
+                sig_attrs->wire.sig.dif.ref_tag = se_cmd->reftag_seed;
+                break;
+        default:
+                pr_err("Unsupported PI operation %d\n", se_cmd->prot_op);
+                return -EINVAL;
+        }
+
+        return 0;
+}
+
+static inline u8
+isert_set_prot_checks(u8 prot_checks)
+{
+        return (prot_checks & TARGET_DIF_CHECK_GUARD  ? 0xc0 : 0) |
+               (prot_checks & TARGET_DIF_CHECK_REFTAG ? 0x30 : 0) |
+               (prot_checks & TARGET_DIF_CHECK_REFTAG ? 0x0f : 0);
+}
+
+static int
+isert_reg_sig_mr(struct isert_conn *isert_conn, struct se_cmd *se_cmd,
+                 struct fast_reg_descriptor *fr_desc,
+                 struct ib_sge *data_sge, struct ib_sge *prot_sge,
+                 struct ib_sge *sig_sge)
+{
+        struct ib_send_wr sig_wr, inv_wr;
+        struct ib_send_wr *bad_wr, *wr = NULL;
+        struct pi_context *pi_ctx = fr_desc->pi_ctx;
+        struct ib_sig_attrs sig_attrs;
+        int ret;
+        u32 key;
+
+        memset(&sig_attrs, 0, sizeof(sig_attrs));
+        ret = isert_set_sig_attrs(se_cmd, &sig_attrs);
+        if (ret)
+                goto err;
+
+        sig_attrs.check_mask = isert_set_prot_checks(se_cmd->prot_checks);
+
+        if (!(fr_desc->ind & ISERT_SIG_KEY_VALID)) {
+                memset(&inv_wr, 0, sizeof(inv_wr));
+                inv_wr.opcode = IB_WR_LOCAL_INV;
+                inv_wr.ex.invalidate_rkey = pi_ctx->sig_mr->rkey;
+                wr = &inv_wr;
+                /* Bump the key */
+                key = (u8)(pi_ctx->sig_mr->rkey & 0x000000FF);
+                ib_update_fast_reg_key(pi_ctx->sig_mr, ++key);
+        }
+
+        memset(&sig_wr, 0, sizeof(sig_wr));
+        sig_wr.opcode = IB_WR_REG_SIG_MR;
+        sig_wr.sg_list = data_sge;
+        sig_wr.num_sge = 1;
+        sig_wr.wr.sig_handover.access_flags = IB_ACCESS_LOCAL_WRITE;
+        sig_wr.wr.sig_handover.sig_attrs = &sig_attrs;
+        sig_wr.wr.sig_handover.sig_mr = pi_ctx->sig_mr;
+        if (se_cmd->t_prot_sg)
+                sig_wr.wr.sig_handover.prot = prot_sge;
+
+        if (!wr)
+                wr = &sig_wr;
+        else
+                wr->next = &sig_wr;
+
+        ret = ib_post_send(isert_conn->conn_qp, wr, &bad_wr);
+        if (ret) {
+                pr_err("fast registration failed, ret:%d\n", ret);
+                goto err;
+        }
+        fr_desc->ind &= ~ISERT_SIG_KEY_VALID;
+
+        sig_sge->lkey = pi_ctx->sig_mr->lkey;
+        sig_sge->addr = 0;
+        sig_sge->length = se_cmd->data_length;
+        if (se_cmd->prot_op != TARGET_PROT_DIN_STRIP &&
+            se_cmd->prot_op != TARGET_PROT_DOUT_INSERT)
+                /*
+                 * We have protection guards on the wire
+                 * so we need to set a larget transfer
+                 */
+                sig_sge->length += se_cmd->prot_length;
+
+        pr_debug("sig_sge: addr: 0x%llx  length: %u lkey: %x\n",
+                 sig_sge->addr, sig_sge->length,
+                 sig_sge->lkey);
+err:
+        return ret;
+}
+
 static int
 isert_reg_rdma(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
                struct isert_rdma_wr *wr)
@@ -2426,6 +2664,7 @@ isert_reg_rdma(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
         struct se_cmd *se_cmd = &cmd->se_cmd;
         struct isert_cmd *isert_cmd = iscsit_priv_cmd(cmd);
         struct isert_conn *isert_conn = conn->context;
+        struct ib_sge data_sge;
         struct ib_send_wr *send_wr;
         struct fast_reg_descriptor *fr_desc = NULL;
         u32 offset;
@@ -2441,7 +2680,8 @@ isert_reg_rdma(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
         if (ret)
                 return ret;
 
-        if (wr->data.dma_nents != 1) {
+        if (wr->data.dma_nents != 1 ||
+            se_cmd->prot_op != TARGET_PROT_NORMAL) {
                 spin_lock_irqsave(&isert_conn->conn_lock, flags);
                 fr_desc = list_first_entry(&isert_conn->conn_fr_pool,
                                            struct fast_reg_descriptor, list);
@@ -2450,10 +2690,39 @@ isert_reg_rdma(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
                 wr->fr_desc = fr_desc;
         }
 
-        ret = isert_fast_reg_mr(isert_conn, fr_desc, &wr->data, &wr->s_ib_sge);
+        ret = isert_fast_reg_mr(isert_conn, fr_desc, &wr->data,
+                                ISERT_DATA_KEY_VALID, &data_sge);
         if (ret)
                 goto unmap_cmd;
 
+        if (se_cmd->prot_op != TARGET_PROT_NORMAL) {
+                struct ib_sge prot_sge, sig_sge;
+
+                if (se_cmd->t_prot_sg) {
+                        ret = isert_map_data_buf(isert_conn, isert_cmd,
+                                                 se_cmd->t_prot_sg,
+                                                 se_cmd->t_prot_nents,
+                                                 se_cmd->prot_length,
+                                                 0, wr->iser_ib_op, &wr->prot);
+                        if (ret)
+                                goto unmap_cmd;
+
+                        ret = isert_fast_reg_mr(isert_conn, fr_desc, &wr->prot,
+                                                ISERT_PROT_KEY_VALID, &prot_sge);
+                        if (ret)
+                                goto unmap_prot_cmd;
+                }
+
+                ret = isert_reg_sig_mr(isert_conn, se_cmd, fr_desc,
+                                       &data_sge, &prot_sge, &sig_sge);
+                if (ret)
+                        goto unmap_prot_cmd;
+
+                fr_desc->ind |= ISERT_PROTECTED;
+                memcpy(&wr->s_ib_sge, &sig_sge, sizeof(sig_sge));
+        } else
+                memcpy(&wr->s_ib_sge, &data_sge, sizeof(data_sge));
+
         wr->ib_sge = &wr->s_ib_sge;
         wr->send_wr_num = 1;
         memset(&wr->s_send_wr, 0, sizeof(*send_wr));
@@ -2468,8 +2737,8 @@ isert_reg_rdma(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
                 send_wr->opcode = IB_WR_RDMA_WRITE;
                 send_wr->wr.rdma.remote_addr = isert_cmd->read_va;
                 send_wr->wr.rdma.rkey = isert_cmd->read_stag;
-                send_wr->send_flags = 0;
-                send_wr->next = &isert_cmd->tx_desc.send_wr;
+                send_wr->send_flags = se_cmd->prot_op == TARGET_PROT_NORMAL ?
+                                      0 : IB_SEND_SIGNALED;
         } else {
                 send_wr->opcode = IB_WR_RDMA_READ;
                 send_wr->wr.rdma.remote_addr = isert_cmd->write_va;
@@ -2478,6 +2747,9 @@ isert_reg_rdma(struct iscsi_conn *conn, struct iscsi_cmd *cmd,
         }
 
         return 0;
+unmap_prot_cmd:
+        if (se_cmd->t_prot_sg)
+                isert_unmap_data_buf(isert_conn, &wr->prot);
 unmap_cmd:
         if (fr_desc) {
                 spin_lock_irqsave(&isert_conn->conn_lock, flags);
@@ -2509,15 +2781,19 @@ isert_put_datain(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
                 return rc;
         }
 
-        /*
-         * Build isert_conn->tx_desc for iSCSI response PDU and attach
-         */
-        isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
-        iscsit_build_rsp_pdu(cmd, conn, true, (struct iscsi_scsi_rsp *)
-                             &isert_cmd->tx_desc.iscsi_header);
-        isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
-        isert_init_send_wr(isert_conn, isert_cmd,
-                           &isert_cmd->tx_desc.send_wr, true);
+        if (se_cmd->prot_op == TARGET_PROT_NORMAL) {
+                /*
+                 * Build isert_conn->tx_desc for iSCSI response PDU and attach
+                 */
+                isert_create_send_desc(isert_conn, isert_cmd,
+                                       &isert_cmd->tx_desc);
+                iscsit_build_rsp_pdu(cmd, conn, true, (struct iscsi_scsi_rsp *)
+                                     &isert_cmd->tx_desc.iscsi_header);
+                isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
+                isert_init_send_wr(isert_conn, isert_cmd,
+                                   &isert_cmd->tx_desc.send_wr, true);
+                isert_cmd->rdma_wr.s_send_wr.next = &isert_cmd->tx_desc.send_wr;
+        }
 
         atomic_add(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
 
@@ -2526,8 +2802,13 @@ isert_put_datain(struct iscsi_conn *conn, struct iscsi_cmd *cmd)
                 pr_warn("ib_post_send() failed for IB_WR_RDMA_WRITE\n");
                 atomic_sub(wr->send_wr_num + 1, &isert_conn->post_send_buf_count);
         }
-        pr_debug("Cmd: %p posted RDMA_WRITE + Response for iSER Data READ\n",
-                 isert_cmd);
+
+        if (se_cmd->prot_op == TARGET_PROT_NORMAL)
+                pr_debug("Cmd: %p posted RDMA_WRITE + Response for iSER Data "
+                         "READ\n", isert_cmd);
+        else
+                pr_debug("Cmd: %p posted RDMA_WRITE for iSER Data READ\n",
+                         isert_cmd);
 
         return 1;
 }
diff --git a/drivers/infiniband/ulp/isert/ib_isert.h b/drivers/infiniband/ulp/isert/ib_isert.h
index a75b75fbc9d1..4c072ae34c01 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.h
+++ b/drivers/infiniband/ulp/isert/ib_isert.h
@@ -91,6 +91,7 @@ struct isert_rdma_wr {
         struct ib_send_wr       *send_wr;
         struct ib_send_wr       s_send_wr;
         struct isert_data_buf   data;
+        struct isert_data_buf   prot;
         struct fast_reg_descriptor *fr_desc;
 };