iscsi-target: Refactor RX PDU logic + export request PDU handling

This patch refactors existing traditional iscsi RX side PDU handling
to use iscsit_transport, and exports the necessary logic for external
transport modules.

This includes:

- Refactor iscsit_handle_scsi_cmd() into PDU setup / processing
- Add updated iscsit_handle_scsi_cmd() for tradtional iscsi code
- Add iscsit_set_unsoliticed_dataout() wrapper
- Refactor iscsit_handle_data_out() into PDU check / processing
- Add updated iscsit_handle_data_out() for tradtional iscsi code
- Add iscsit_handle_nop_out() + iscsit_handle_task_mgt_cmd() to
  accept pre-allocated struct iscsi_cmd
- Add iscsit_build_r2ts_for_cmd() caller for iscsi_target_transport
  to handle ISTATE_SEND_R2T for TX immediate queue
- Refactor main traditional iscsi iscsi_target_rx_thread() PDU switch
  into iscsi_target_rx_opcode() using iscsit_allocate_cmd()
- Turn iscsi_target_rx_thread() process context into NOP for
  ib_isert side work-queue.

v5 changes:

- Make iscsit_handle_scsi_cmd() static (Fengguang)
- Fix iscsit_handle_scsi_cmd() exception se_cmd leak (nab)

v3 changes:
- Add extra target_put_sess_cmd call in iscsit_add_reject_from_cmd
  after completion

v2 changes:

- Disable iscsit_ack_from_expstatsn() usage for RDMAExtentions=Yes
- Disable iscsit_allocate_datain_req() usage for RDMAExtentions=Yes
- Add target_get_sess_cmd() reference counting to
  iscsit_setup_scsi_cmd()
- Add TFO->lio_check_stop_free() fabric API caller
- Add export of iscsit_stop_dataout_timer() symbol
- Add iscsit_build_r2ts_for_cmd() for iscsit_transport->iscsit_get_dataout()
- Convert existing usage of iscsit_build_r2ts_for_cmd() to
  ->iscsit_get_dataout()
- Drop RDMAExtentions=Yes specific check in iscsit_build_r2ts_for_cmd()
- Fix RDMAExtentions -> RDMAExtensions typo (andy)
- Pass correct dump_payload value into iscsit_get_immediate_data()
  for iscsit_handle_scsi_cmd()

Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 8 insertions, 5 deletions

diff --git a/drivers/target/iscsi/iscsi_target_erl1.c b/drivers/target/iscsi/iscsi_target_erl1.c
index 0b52a2371305..7816af6cdd12 100644
--- a/drivers/target/iscsi/iscsi_target_erl1.c
+++ b/drivers/target/iscsi/iscsi_target_erl1.c
@@ -22,6 +22,7 @@
 #include <scsi/iscsi_proto.h>
 #include <target/target_core_base.h>
 #include <target/target_core_fabric.h>
+#include <target/iscsi/iscsi_transport.h>
 
 #include "iscsi_target_core.h"
 #include "iscsi_target_seq_pdu_list.h"
@@ -53,6 +54,9 @@ int iscsit_dump_data_payload(
         u32 length, padding, offset = 0, size;
         struct kvec iov;
 
+        if (conn->sess->sess_ops->RDMAExtensions)
+                return 0;
+
         length = (buf_len > OFFLOAD_BUF_SIZE) ? OFFLOAD_BUF_SIZE : buf_len;
 
         buf = kzalloc(length, GFP_ATOMIC);
@@ -919,6 +923,7 @@ int iscsit_execute_ooo_cmdsns(struct iscsi_session *sess)
 int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
 {
         struct se_cmd *se_cmd = &cmd->se_cmd;
+        struct iscsi_conn *conn = cmd->conn;
         int lr = 0;
 
         spin_lock_bh(&cmd->istate_lock);
@@ -981,7 +986,7 @@ int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
                                         return 0;
 
                                 iscsit_set_dataout_sequence_values(cmd);
-                                iscsit_build_r2ts_for_cmd(cmd, cmd->conn, false);
+                                conn->conn_transport->iscsit_get_dataout(conn, cmd, false);
                         }
                         return 0;
                 }
@@ -999,10 +1004,7 @@ int iscsit_execute_cmd(struct iscsi_cmd *cmd, int ooo)
                         if (transport_check_aborted_status(se_cmd, 1) != 0)
                                 return 0;
 
-                        iscsit_set_dataout_sequence_values(cmd);
-                        spin_lock_bh(&cmd->dataout_timeout_lock);
-                        iscsit_start_dataout_timer(cmd, cmd->conn);
-                        spin_unlock_bh(&cmd->dataout_timeout_lock);
+                        iscsit_set_unsoliticed_dataout(cmd);
                 }
                 return transport_handle_cdb_direct(&cmd->se_cmd);
 
@@ -1290,3 +1292,4 @@ void iscsit_stop_dataout_timer(struct iscsi_cmd *cmd)
                         cmd->init_task_tag);
         spin_unlock_bh(&cmd->dataout_timeout_lock);
 }
+EXPORT_SYMBOL(iscsit_stop_dataout_timer);