[PATCH 17/18] scsi: target: Remove sess_cmd_lock

[Mike Christie <michael.christie@oracle.com>]

We used to ue the sess_cmd_lock to grab a ref to the se_cmd and add it to
the se_cmd_list if the session was not being stopped. And if the cmd was
being completed while __target_check_io_state was being run then we held
the lock while taking a ref because we were looping over the se_cmd_list
and because we didn't remove the cmd from the list until after the last
ref was released in target_release_cmd_kref.

In:

Commit 6f55b06f9b07 ("scsi: target: Drop sess_cmd_lock from I/O path")

we switched from the sess list and lock use to the per cpu session
cmd_count, so the lock was no longer needed, but it didn't get removed
from __target_check_io_state. This patch removes the last target uses of
sess_cmd_lock.

Signed-off-by: Mike Christie <michael.christie@oracle.com>
---
 drivers/target/target_core_tmr.c       | 11 -----------
 drivers/target/target_core_transport.c |  1 -
 include/target/target_core_base.h      |  1 -
 3 files changed, 13 deletions(-)

diff --git a/drivers/target/target_core_tmr.c b/drivers/target/target_core_tmr.c
index 88d2a7839876..6fa037ffc119 100644
--- a/drivers/target/target_core_tmr.c
+++ b/drivers/target/target_core_tmr.c
@@ -71,10 +71,6 @@ static int target_check_cdb_and_preempt(struct list_head *list,
 static bool __target_check_io_state(struct se_cmd *se_cmd,
 				    struct se_session *tmr_sess, bool tas)
 {
-	struct se_session *sess = se_cmd->se_sess;
-
-	lockdep_assert_held(&sess->sess_cmd_lock);
-
 	/*
 	 * If command already reached CMD_T_COMPLETE state within
 	 * target_complete_cmd() or CMD_T_FABRIC_STOP due to shutdown,
@@ -137,9 +133,7 @@ void core_tmr_abort_task(
 			pr_err("ABORT_TASK: Found referenced %s task_tag: %llu\n",
 			       se_cmd->se_tfo->fabric_name, ref_tag);
 
-			spin_lock(&se_sess->sess_cmd_lock);
 			rc = __target_check_io_state(se_cmd, se_sess, 0);
-			spin_unlock(&se_sess->sess_cmd_lock);
 			if (!rc)
 				continue;
 
@@ -206,10 +200,7 @@ static void core_tmr_drain_tmr_list(
 		if (WARN_ON_ONCE(!sess))
 			continue;
 
-		spin_lock(&sess->sess_cmd_lock);
 		rc = __target_check_io_state(cmd, sess, 0);
-		spin_unlock(&sess->sess_cmd_lock);
-
 		if (!rc) {
 			printk("LUN_RESET TMR: non-zero kref_get_unless_zero\n");
 			continue;
@@ -310,9 +301,7 @@ static void core_tmr_drain_state_list(
 			if (WARN_ON_ONCE(!sess))
 				continue;
 
-			spin_lock(&sess->sess_cmd_lock);
 			rc = __target_check_io_state(cmd, tmr_sess, tas);
-			spin_unlock(&sess->sess_cmd_lock);
 			if (!rc)
 				continue;
 
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 692104325b38..c260cb60f5cb 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -277,7 +277,6 @@ void transport_init_session(struct se_session *se_sess)
 {
 	INIT_LIST_HEAD(&se_sess->sess_list);
 	INIT_LIST_HEAD(&se_sess->sess_acl_list);
-	spin_lock_init(&se_sess->sess_cmd_lock);
 }
 EXPORT_SYMBOL(transport_init_session);
 
diff --git a/include/target/target_core_base.h b/include/target/target_core_base.h
index 0a5b51f8e5e8..845db96f50dd 100644
--- a/include/target/target_core_base.h
+++ b/include/target/target_core_base.h
@@ -636,7 +636,6 @@ struct se_session {
 	void			*fabric_sess_ptr;
 	struct list_head	sess_list;
 	struct list_head	sess_acl_list;
-	spinlock_t		sess_cmd_lock;
 	void			*sess_cmd_map;
 	struct sbitmap_queue	sess_tag_pool;
 	struct target_cmd_counter *cmd_cnt;
-- 
2.31.1