target: More core cleanups from AGrover (round 2)

This patch contains the squashed version of second round of target core
cleanups and simplifications and Andy and Co.   It also contains a handful
of fixes to address bugs the original series and other minor cleanups.

Here is the condensed shortlog:

target: Remove unneeded casts to void*
target: Rename get_lun_for_{cmd,tmr} to lookup_{cmd,tmr}_lun
target: Make t_task a member of se_cmd, not a pointer
target: Handle functions returning "-2"
target: Use cmd->se_dev over cmd->se_lun->lun_se_dev
target: Embed qr in struct se_cmd
target: Replace embedded struct se_queue_req with a list_head
target: Rename list_heads that are nodes in struct se_cmd to "*_node"
target: Fold transport_device_setup_cmd() into lookup_{tmr,cmd}_lun()
target: Make t_mem_list and t_mem_list_bidi members of t_task
target: Add comment & cleanup transport_map_sg_to_mem()
target: Remove unneeded checks in transport_free_pages()

(Roland: Fix se_queue_req removal leftovers OOPs)
(nab: Fix transport_lookup_tmr_lun failure case)
(nab: Fix list_empty(&cmd->t_task.t_mem_bidi_list) inversion bugs)

Signed-off-by: Andy Grover <agrover@redhat.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

3 files changed, 18 insertions, 20 deletions

diff --git a/drivers/target/tcm_fc/tfc_cmd.c b/drivers/target/tcm_fc/tfc_cmd.c
index 19b2b9948314..6d9553bbba30 100644
--- a/drivers/target/tcm_fc/tfc_cmd.c
+++ b/drivers/target/tcm_fc/tfc_cmd.c
@@ -72,16 +72,16 @@ void ft_dump_cmd(struct ft_cmd *cmd, const char *caller)
                 caller, cmd, cmd->cdb);
         printk(KERN_INFO "%s: cmd %p lun %d\n", caller, cmd, cmd->lun);
 
-        task = se_cmd->t_task;
+        task = &se_cmd->t_task;
         printk(KERN_INFO "%s: cmd %p task %p se_num %u buf %p len %u se_cmd_flags <0x%x>\n",
                caller, cmd, task, task->t_tasks_se_num,
                task->t_task_buf, se_cmd->data_length, se_cmd->se_cmd_flags);
-        if (task->t_mem_list)
-                list_for_each_entry(mem, task->t_mem_list, se_list)
-                        printk(KERN_INFO "%s: cmd %p mem %p page %p "
-                               "len 0x%x off 0x%x\n",
-                               caller, cmd, mem,
-                               mem->se_page, mem->se_len, mem->se_off);
+
+        list_for_each_entry(mem, &task->t_mem_list, se_list)
+                printk(KERN_INFO "%s: cmd %p mem %p page %p "
+                       "len 0x%x off 0x%x\n",
+                       caller, cmd, mem,
+                       mem->se_page, mem->se_len, mem->se_off);
         sp = cmd->seq;
         if (sp) {
                 ep = fc_seq_exch(sp);
@@ -262,9 +262,9 @@ int ft_write_pending(struct se_cmd *se_cmd)
                                  * TCM/LIO target
                                  */
                                 transport_do_task_sg_chain(se_cmd);
-                                cmd->sg = se_cmd->t_task->t_tasks_sg_chained;
+                                cmd->sg = se_cmd->t_task.t_tasks_sg_chained;
                                 cmd->sg_cnt =
-                                        se_cmd->t_task->t_tasks_sg_chained_no;
+                                        se_cmd->t_task.t_tasks_sg_chained_no;
                         }
                         if (cmd->sg && lport->tt.ddp_setup(lport, ep->xid,
                                                     cmd->sg, cmd->sg_cnt))
@@ -438,7 +438,7 @@ static void ft_send_tm(struct ft_cmd *cmd)
         switch (fcp->fc_tm_flags) {
         case FCP_TMF_LUN_RESET:
                 cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
-                if (transport_get_lun_for_tmr(&cmd->se_cmd, cmd->lun) < 0) {
+                if (transport_lookup_tmr_lun(&cmd->se_cmd, cmd->lun) < 0) {
                         /*
                          * Make sure to clean up newly allocated TMR request
                          * since "unable to  handle TMR request because failed
@@ -637,7 +637,7 @@ static void ft_send_cmd(struct ft_cmd *cmd)
         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_get_lun_for_cmd(&cmd->se_cmd, cmd->lun);
+        ret = transport_lookup_cmd_lun(&cmd->se_cmd, cmd->lun);
         if (ret < 0) {
                 ft_dump_cmd(cmd, __func__);
                 transport_send_check_condition_and_sense(&cmd->se_cmd,
@@ -650,13 +650,13 @@ static void ft_send_cmd(struct ft_cmd *cmd)
         FT_IO_DBG("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
         ft_dump_cmd(cmd, __func__);
 
-        if (ret == -1) {
+        if (ret == -ENOMEM) {
                 transport_send_check_condition_and_sense(se_cmd,
                                 TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
                 transport_generic_free_cmd(se_cmd, 0, 1, 0);
                 return;
         }
-        if (ret == -2) {
+        if (ret == -EINVAL) {
                 if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
                         ft_queue_status(se_cmd);
                 else
diff --git a/drivers/target/tcm_fc/tfc_conf.c b/drivers/target/tcm_fc/tfc_conf.c
index 8c5067c65720..58e4745749db 100644
--- a/drivers/target/tcm_fc/tfc_conf.c
+++ b/drivers/target/tcm_fc/tfc_conf.c
@@ -331,7 +331,7 @@ static struct se_portal_group *ft_add_tpg(
         transport_init_queue_obj(&tpg->qobj);
 
         ret = core_tpg_register(&ft_configfs->tf_ops, wwn, &tpg->se_tpg,
-                                (void *)tpg, TRANSPORT_TPG_TYPE_NORMAL);
+                                tpg, TRANSPORT_TPG_TYPE_NORMAL);
         if (ret < 0) {
                 kfree(tpg);
                 return NULL;
diff --git a/drivers/target/tcm_fc/tfc_io.c b/drivers/target/tcm_fc/tfc_io.c
index 47efcfb9f4b8..f18af6e99b83 100644
--- a/drivers/target/tcm_fc/tfc_io.c
+++ b/drivers/target/tcm_fc/tfc_io.c
@@ -90,15 +90,14 @@ int ft_queue_data_in(struct se_cmd *se_cmd)
         lport = ep->lp;
         cmd->seq = lport->tt.seq_start_next(cmd->seq);
 
-        task = se_cmd->t_task;
-        BUG_ON(!task);
+        task = &se_cmd->t_task;
         remaining = se_cmd->data_length;
 
         /*
          * Setup to use first mem list entry if any.
          */
         if (task->t_tasks_se_num) {
-                mem = list_first_entry(task->t_mem_list,
+                mem = list_first_entry(&task->t_mem_list,
                          struct se_mem, se_list);
                 mem_len = mem->se_len;
                 mem_off = mem->se_off;
@@ -236,8 +235,7 @@ void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
         u32 f_ctl;
         void *buf;
 
-        task = se_cmd->t_task;
-        BUG_ON(!task);
+        task = &se_cmd->t_task;
 
         fh = fc_frame_header_get(fp);
         if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
@@ -315,7 +313,7 @@ void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
          * Setup to use first mem list entry if any.
          */
         if (task->t_tasks_se_num) {
-                mem = list_first_entry(task->t_mem_list,
+                mem = list_first_entry(&task->t_mem_list,
                                        struct se_mem, se_list);
                 mem_len = mem->se_len;
                 mem_off = mem->se_off;