iser-target: Add support for ISCSI_OP_TEXT opcode + payload handling

This patch adds isert_handle_text_cmd() to handle incoming
ISCSI_OP_TEXT PDU processing, along with isert_put_text_rsp()
for posting ISCSI_OP_TEXT_RSP ib_send_wr response.

It copies ISCSI_OP_TEXT payload using unsolicited payload at
&iser_rx_desc->data[0] into iscsi_cmd->text_in_ptr for usage
with outgoing isert_put_text_rsp() -> iscsit_build_text_rsp()

v2 changes:
  - Let iscsit_build_text_rsp() determine any extra padding

Reported-by: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Cc: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 88 insertions, 1 deletions

diff --git a/drivers/infiniband/ulp/isert/ib_isert.c b/drivers/infiniband/ulp/isert/ib_isert.c
index fa4251803577..f02bfcc282e5 100644
--- a/drivers/infiniband/ulp/isert/ib_isert.c
+++ b/drivers/infiniband/ulp/isert/ib_isert.c
@@ -1033,6 +1033,33 @@ isert_handle_nop_out(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
 }
 
 static int
+isert_handle_text_cmd(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
+                      struct iser_rx_desc *rx_desc, struct iscsi_text *hdr)
+{
+        struct iscsi_cmd *cmd = &isert_cmd->iscsi_cmd;
+        struct iscsi_conn *conn = isert_conn->conn;
+        u32 payload_length = ntoh24(hdr->dlength);
+        int rc;
+        unsigned char *text_in;
+
+        rc = iscsit_setup_text_cmd(conn, cmd, hdr);
+        if (rc < 0)
+                return rc;
+
+        text_in = kzalloc(payload_length, GFP_KERNEL);
+        if (!text_in) {
+                pr_err("Unable to allocate text_in of payload_length: %u\n",
+                       payload_length);
+                return -ENOMEM;
+        }
+        cmd->text_in_ptr = text_in;
+
+        memcpy(cmd->text_in_ptr, &rx_desc->data[0], payload_length);
+
+        return iscsit_process_text_cmd(conn, cmd, hdr);
+}
+
+static int
 isert_rx_opcode(struct isert_conn *isert_conn, struct iser_rx_desc *rx_desc,
                 uint32_t read_stag, uint64_t read_va,
                 uint32_t write_stag, uint64_t write_va)
@@ -1091,6 +1118,15 @@ isert_rx_opcode(struct isert_conn *isert_conn, struct iser_rx_desc *rx_desc,
                                                     SECONDS_FOR_LOGOUT_COMP *
                                                     HZ);
                 break;
+        case ISCSI_OP_TEXT:
+                cmd = iscsit_allocate_cmd(conn, GFP_KERNEL);
+                if (!cmd)
+                        break;
+
+                isert_cmd = container_of(cmd, struct isert_cmd, iscsi_cmd);
+                ret = isert_handle_text_cmd(isert_conn, isert_cmd,
+                                            rx_desc, (struct iscsi_text *)hdr);
+                break;
         default:
                 pr_err("Got unknown iSCSI OpCode: 0x%02x\n", opcode);
                 dump_stack();
@@ -1245,6 +1281,7 @@ isert_put_cmd(struct isert_cmd *isert_cmd)
                 break;
         case ISCSI_OP_REJECT:
         case ISCSI_OP_NOOP_OUT:
+        case ISCSI_OP_TEXT:
                 spin_lock_bh(&conn->cmd_lock);
                 if (!list_empty(&cmd->i_conn_node))
                         list_del(&cmd->i_conn_node);
@@ -1366,6 +1403,11 @@ isert_do_control_comp(struct work_struct *work)
                 isert_conn->logout_posted = true;
                 iscsit_logout_post_handler(cmd, cmd->conn);
                 break;
+        case ISTATE_SEND_TEXTRSP:
+                atomic_dec(&isert_conn->post_send_buf_count);
+                cmd->i_state = ISTATE_SENT_STATUS;
+                isert_completion_put(&isert_cmd->tx_desc, isert_cmd, ib_dev);
+                break;
         default:
                 pr_err("Unknown do_control_comp i_state %d\n", cmd->i_state);
                 dump_stack();
@@ -1383,7 +1425,8 @@ isert_response_completion(struct iser_tx_desc *tx_desc,
 
         if (cmd->i_state == ISTATE_SEND_TASKMGTRSP ||
             cmd->i_state == ISTATE_SEND_LOGOUTRSP ||
-            cmd->i_state == ISTATE_SEND_REJECT) {
+            cmd->i_state == ISTATE_SEND_REJECT ||
+            cmd->i_state == ISTATE_SEND_TEXTRSP) {
                 isert_unmap_tx_desc(tx_desc, ib_dev);
 
                 INIT_WORK(&isert_cmd->comp_work, isert_do_control_comp);
@@ -1709,6 +1752,47 @@ isert_put_reject(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
 }
 
 static int
+isert_put_text_rsp(struct iscsi_cmd *cmd, struct iscsi_conn *conn)
+{
+        struct isert_cmd *isert_cmd = container_of(cmd,
+                                struct isert_cmd, iscsi_cmd);
+        struct isert_conn *isert_conn = (struct isert_conn *)conn->context;
+        struct ib_send_wr *send_wr = &isert_cmd->tx_desc.send_wr;
+        struct iscsi_text_rsp *hdr =
+                (struct iscsi_text_rsp *)&isert_cmd->tx_desc.iscsi_header;
+        u32 txt_rsp_len;
+        int rc;
+
+        isert_create_send_desc(isert_conn, isert_cmd, &isert_cmd->tx_desc);
+        rc = iscsit_build_text_rsp(cmd, conn, hdr);
+        if (rc < 0)
+                return rc;
+
+        txt_rsp_len = rc;
+        isert_init_tx_hdrs(isert_conn, &isert_cmd->tx_desc);
+
+        if (txt_rsp_len) {
+                struct ib_device *ib_dev = isert_conn->conn_cm_id->device;
+                struct ib_sge *tx_dsg = &isert_cmd->tx_desc.tx_sg[1];
+                void *txt_rsp_buf = cmd->buf_ptr;
+
+                isert_cmd->pdu_buf_dma = ib_dma_map_single(ib_dev,
+                                txt_rsp_buf, txt_rsp_len, DMA_TO_DEVICE);
+
+                isert_cmd->pdu_buf_len = txt_rsp_len;
+                tx_dsg->addr    = isert_cmd->pdu_buf_dma;
+                tx_dsg->length  = txt_rsp_len;
+                tx_dsg->lkey    = isert_conn->conn_mr->lkey;
+                isert_cmd->tx_desc.num_sge = 2;
+        }
+        isert_init_send_wr(isert_cmd, send_wr);
+
+        pr_debug("Posting Text Response IB_WR_SEND >>>>>>>>>>>>>>>>>>>>>>\n");
+
+        return isert_post_response(isert_conn, isert_cmd);
+}
+
+static int
 isert_build_rdma_wr(struct isert_conn *isert_conn, struct isert_cmd *isert_cmd,
                     struct ib_sge *ib_sge, struct ib_send_wr *send_wr,
                     u32 data_left, u32 offset)
@@ -2006,6 +2090,9 @@ isert_response_queue(struct iscsi_conn *conn, struct iscsi_cmd *cmd, int state)
         case ISTATE_SEND_REJECT:
                 ret = isert_put_reject(cmd, conn);
                 break;
+        case ISTATE_SEND_TEXTRSP:
+                ret = isert_put_text_rsp(cmd, conn);
+                break;
         case ISTATE_SEND_STATUS:
                 /*
                  * Special case for sending non GOOD SCSI status from TX thread