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 19b2b99..6d9553b 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 8c5067c..58e4745 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 47efcfb..f18af6e 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;