tcm_loop: kill tcm_loop_allocate_core_cmd

This function makes little sense as a separate abstraction as it's deeply
interwinded with the control flow of its only caller.  Merged it into
tcm_loop_queuecommand after factoring out a helper to convert the task
attribute representation.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

1 files changed, 59 insertions, 88 deletions

diff --git a/drivers/target/loopback/tcm_loop.c b/drivers/target/loopback/tcm_loop.c
index 7cfbcb00b3c3..b1edc517f4e3 100644
--- a/drivers/target/loopback/tcm_loop.c
+++ b/drivers/target/loopback/tcm_loop.c
@@ -49,81 +49,6 @@ static struct kmem_cache *tcm_loop_cmd_cache;
 static int tcm_loop_hba_no_cnt;
 
 /*
- * Allocate a tcm_loop cmd descriptor from target_core_mod code
- *
- * Can be called from interrupt context in tcm_loop_queuecommand() below
- */
-static struct se_cmd *tcm_loop_allocate_core_cmd(
-        struct tcm_loop_hba *tl_hba,
-        struct se_portal_group *se_tpg,
-        struct scsi_cmnd *sc)
-{
-        struct se_cmd *se_cmd;
-        struct se_session *se_sess;
-        struct tcm_loop_nexus *tl_nexus = tl_hba->tl_nexus;
-        struct tcm_loop_cmd *tl_cmd;
-        int sam_task_attr;
-
-        if (!tl_nexus) {
-                scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
-                                " does not exist\n");
-                set_host_byte(sc, DID_ERROR);
-                return NULL;
-        }
-        se_sess = tl_nexus->se_sess;
-
-        tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
-        if (!tl_cmd) {
-                pr_err("Unable to allocate struct tcm_loop_cmd\n");
-                set_host_byte(sc, DID_ERROR);
-                return NULL;
-        }
-        se_cmd = &tl_cmd->tl_se_cmd;
-        /*
-         * Save the pointer to struct scsi_cmnd *sc
-         */
-        tl_cmd->sc = sc;
-        /*
-         * Locate the SAM Task Attr from struct scsi_cmnd *
-         */
-        if (sc->device->tagged_supported) {
-                switch (sc->tag) {
-                case HEAD_OF_QUEUE_TAG:
-                        sam_task_attr = MSG_HEAD_TAG;
-                        break;
-                case ORDERED_QUEUE_TAG:
-                        sam_task_attr = MSG_ORDERED_TAG;
-                        break;
-                default:
-                        sam_task_attr = MSG_SIMPLE_TAG;
-                        break;
-                }
-        } else
-                sam_task_attr = MSG_SIMPLE_TAG;
-
-        /*
-         * Initialize struct se_cmd descriptor from target_core_mod infrastructure
-         */
-        transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
-                        scsi_bufflen(sc), sc->sc_data_direction, sam_task_attr,
-                        &tl_cmd->tl_sense_buf[0]);
-
-        if (scsi_bidi_cmnd(sc))
-                se_cmd->se_cmd_flags |= SCF_BIDI;
-
-        /*
-         * Locate the struct se_lun pointer and attach it to struct se_cmd
-         */
-        if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
-                kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
-                set_host_byte(sc, DID_NO_CONNECT);
-                return NULL;
-        }
-
-        return se_cmd;
-}
-
-/*
  * Called by struct target_core_fabric_ops->new_cmd_map()
  *
  * Always called in process context.  A non zero return value
@@ -263,6 +188,25 @@ static int tcm_loop_change_queue_depth(
 }
 
 /*
+ * Locate the SAM Task Attr from struct scsi_cmnd *
+ */
+static int tcm_loop_sam_attr(struct scsi_cmnd *sc)
+{
+        if (sc->device->tagged_supported) {
+                switch (sc->tag) {
+                case HEAD_OF_QUEUE_TAG:
+                        return MSG_HEAD_TAG;
+                case ORDERED_QUEUE_TAG:
+                        return MSG_ORDERED_TAG;
+                default:
+                        break;
+                }
+        }
+
+        return MSG_SIMPLE_TAG;
+}
+
+/*
  * Main entry point from struct scsi_host_template for incoming SCSI CDB+Data
  * from Linux/SCSI subsystem for SCSI low level device drivers (LLDs)
  */
@@ -274,6 +218,10 @@ static int tcm_loop_queuecommand(
         struct se_portal_group *se_tpg;
         struct tcm_loop_hba *tl_hba;
         struct tcm_loop_tpg *tl_tpg;
+        struct se_session *se_sess;
+        struct tcm_loop_nexus *tl_nexus;
+        struct tcm_loop_cmd *tl_cmd;
+
 
         pr_debug("tcm_loop_queuecommand() %d:%d:%d:%d got CDB: 0x%02x"
                 " scsi_buf_len: %u\n", sc->device->host->host_no,
@@ -290,24 +238,47 @@ static int tcm_loop_queuecommand(
          */
         if (!tl_tpg->tl_hba) {
                 set_host_byte(sc, DID_NO_CONNECT);
-                sc->scsi_done(sc);
-                return 0;
+                goto out_done;
         }
         se_tpg = &tl_tpg->tl_se_tpg;
-        /*
-         * Determine the SAM Task Attribute and allocate tl_cmd and
-         * tl_cmd->tl_se_cmd from TCM infrastructure
-         */
-        se_cmd = tcm_loop_allocate_core_cmd(tl_hba, se_tpg, sc);
-        if (!se_cmd) {
-                sc->scsi_done(sc);
-                return 0;
+
+        tl_nexus = tl_hba->tl_nexus;
+        if (!tl_nexus) {
+                scmd_printk(KERN_ERR, sc, "TCM_Loop I_T Nexus"
+                                " does not exist\n");
+                set_host_byte(sc, DID_ERROR);
+                goto out_done;
         }
-        /*
-         * Queue up the newly allocated to be processed in TCM thread context.
-        */
+        se_sess = tl_nexus->se_sess;
+
+        tl_cmd = kmem_cache_zalloc(tcm_loop_cmd_cache, GFP_ATOMIC);
+        if (!tl_cmd) {
+                pr_err("Unable to allocate struct tcm_loop_cmd\n");
+                set_host_byte(sc, DID_ERROR);
+                goto out_done;
+        }
+        se_cmd = &tl_cmd->tl_se_cmd;
+        tl_cmd->sc = sc;
+
+        transport_init_se_cmd(se_cmd, se_tpg->se_tpg_tfo, se_sess,
+                        scsi_bufflen(sc), sc->sc_data_direction,
+                        tcm_loop_sam_attr(sc), &tl_cmd->tl_sense_buf[0]);
+
+        if (scsi_bidi_cmnd(sc))
+                se_cmd->se_cmd_flags |= SCF_BIDI;
+
+        if (transport_lookup_cmd_lun(se_cmd, tl_cmd->sc->device->lun) < 0) {
+                kmem_cache_free(tcm_loop_cmd_cache, tl_cmd);
+                set_host_byte(sc, DID_NO_CONNECT);
+                goto out_done;
+        }
+
         transport_generic_handle_cdb_map(se_cmd);
         return 0;
+
+out_done:
+        sc->scsi_done(sc);
+        return 0;
 }
 
 /*