tcm_fc: Convert ft_send_work to use target_submit_cmd

This patch converts the main ft_send_work() I/O path to use
target_submit_cmd() with a single se_cmd->cmd_kref reference
that is released via the existing ft_check_stop_free() response
path callback.

It also makes ft_send_tm() use transport_init_se_cmd() and
target_get_sess_cmd() to also use single se_cmd->cmd_kref
reference.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 13 insertions, 38 deletions

diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
index dbbbc8376d01..addc18f727ea 100644
--- a/drivers/target/tcm_fc/tfc_cmd.c
+++ b/drivers/target/tcm_fc/tfc_cmd.c
@@ -363,6 +363,11 @@ static void ft_send_tm(struct ft_cmd *cmd)
         struct ft_sess *sess;
         u8 tm_func;
 
+        transport_init_se_cmd(&cmd->se_cmd, &ft_configfs->tf_ops,
+                        cmd->sess->se_sess, 0, DMA_NONE, 0,
+                        &cmd->ft_sense_buffer[0]);
+        target_get_sess_cmd(cmd->sess->se_sess, &cmd->se_cmd, false);
+
         fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
 
         switch (fcp->fc_tm_flags) {
@@ -416,7 +421,6 @@ static void ft_send_tm(struct ft_cmd *cmd)
                         sess = cmd->sess;
                         transport_send_check_condition_and_sense(&cmd->se_cmd,
                                 cmd->se_cmd.scsi_sense_reason, 0);
-                        transport_generic_free_cmd(&cmd->se_cmd, 0);
                         ft_sess_put(sess);
                         return;
                 }
@@ -532,7 +536,6 @@ static void ft_send_work(struct work_struct *work)
 {
         struct ft_cmd *cmd = container_of(work, struct ft_cmd, work);
         struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
-        struct se_cmd *se_cmd;
         struct fcp_cmnd *fcp;
         int data_dir = 0;
         u32 data_len;
@@ -587,15 +590,6 @@ static void ft_send_work(struct work_struct *work)
                 data_len = ntohl(fcp->fc_dl);
                 cmd->cdb = fcp->fc_cdb;
         }
-
-        se_cmd = &cmd->se_cmd;
-        /*
-         * Initialize struct se_cmd descriptor from target_core_mod
-         * infrastructure
-         */
-        transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
-                              data_len, data_dir, task_attr,
-                              &cmd->ft_sense_buffer[0]);
         /*
          * Check for FCP task management flags
          */
@@ -603,39 +597,20 @@ static void ft_send_work(struct work_struct *work)
                 ft_send_tm(cmd);
                 return;
         }
-
         fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
-
         cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
-        ret = transport_lookup_cmd_lun(&cmd->se_cmd, cmd->lun);
+        /*
+         * Use a single se_cmd->cmd_kref as we expect to release se_cmd
+         * directly from ft_check_stop_free callback in response path.
+         */
+        ret = target_submit_cmd(&cmd->se_cmd, cmd->sess->se_sess, cmd->cdb,
+                                &cmd->ft_sense_buffer[0], cmd->lun, data_len,
+                                task_attr, data_dir, 0);
+        pr_debug("r_ctl %x alloc target_submit_cmd %d\n", fh->fh_r_ctl, ret);
         if (ret < 0) {
                 ft_dump_cmd(cmd, __func__);
-                transport_send_check_condition_and_sense(&cmd->se_cmd,
-                        cmd->se_cmd.scsi_sense_reason, 0);
-                return;
-        }
-
-        ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
-
-        pr_debug("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
-        ft_dump_cmd(cmd, __func__);
-
-        if (ret == -ENOMEM) {
-                transport_send_check_condition_and_sense(se_cmd,
-                                TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
-                transport_generic_free_cmd(se_cmd, 0);
-                return;
-        }
-        if (ret == -EINVAL) {
-                if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
-                        ft_queue_status(se_cmd);
-                else
-                        transport_send_check_condition_and_sense(se_cmd,
-                                        se_cmd->scsi_sense_reason, 0);
-                transport_generic_free_cmd(se_cmd, 0);
                 return;
         }
-        transport_handle_cdb_direct(se_cmd);
         return;
 
 err: