Remove the code that clears .se_lun from
transport_cmd_check_stop_to_fabric() such that the
transport_lun_remove_cmd() call can be moved into
target_release_cmd_kref(). Because this guarantees that
transport_lun_remove_cmd() will be called exactly once, it is
safe to change the cmpxchg() call into a test of
se_cmd.lun_ref_active. Inline transport_lun_remove_cmd() because
it is not worth to keep it as a separate function.
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Cc: Nicholas Bellinger <nab@xxxxxxxxxxxxxxx>
Cc: Mike Christie <mchristi@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
drivers/target/target_core_transport.c | 31 +++-----------------------
1 file changed, 3 insertions(+), 28 deletions(-)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index b25d27e8ca20..6471ede00336 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -664,11 +664,6 @@ static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
target_remove_from_state_list(cmd);
- /*
- * Clear struct se_cmd->se_lun before the handoff to FE.
- */
- cmd->se_lun = NULL;
-
spin_lock_irqsave(&cmd->t_state_lock, flags);
/*
* Determine if frontend context caller is requesting the stopping of
@@ -696,17 +691,6 @@ static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
return cmd->se_tfo->check_stop_free(cmd);
}
-static void transport_lun_remove_cmd(struct se_cmd *cmd)
-{
- struct se_lun *lun = cmd->se_lun;
-
- if (!lun)
- return;
-
- if (cmpxchg(&cmd->lun_ref_active, true, false))
- percpu_ref_put(&lun->lun_ref);
-}
-
static void target_complete_failure_work(struct work_struct *work)
{
struct se_cmd *cmd = container_of(work, struct se_cmd, work);
@@ -797,8 +781,6 @@ static void target_handle_abort(struct se_cmd *cmd)
WARN_ON_ONCE(kref_read(&cmd->cmd_kref) == 0);
- transport_lun_remove_cmd(cmd);
-
transport_cmd_check_stop_to_fabric(cmd);
}
@@ -1711,7 +1693,6 @@ static void target_complete_tmr_failure(struct work_struct *work)
se_cmd->se_tmr_req->response = TMR_LUN_DOES_NOT_EXIST;
se_cmd->se_tfo->queue_tm_rsp(se_cmd);
- transport_lun_remove_cmd(se_cmd);
transport_cmd_check_stop_to_fabric(se_cmd);
}
@@ -1902,7 +1883,6 @@ void transport_generic_request_failure(struct se_cmd *cmd,
goto queue_full;
check_stop:
- transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
return;
@@ -2200,7 +2180,6 @@ static void transport_complete_qf(struct se_cmd *cmd)
transport_handle_queue_full(cmd, cmd->se_dev, ret, false);
return;
}
- transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
}
@@ -2295,7 +2274,6 @@ static void target_complete_ok_work(struct work_struct *work)
if (ret)
goto queue_full;
- transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
return;
}
@@ -2321,7 +2299,6 @@ static void target_complete_ok_work(struct work_struct *work)
if (ret)
goto queue_full;
- transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
return;
}
@@ -2357,7 +2334,6 @@ static void target_complete_ok_work(struct work_struct *work)
if (ret)
goto queue_full;
- transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
return;
}
@@ -2393,7 +2369,6 @@ static void target_complete_ok_work(struct work_struct *work)
break;
}
- transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
return;
@@ -2720,9 +2695,6 @@ int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)
*/
if (cmd->state_active)
target_remove_from_state_list(cmd);
-
- if (cmd->se_lun)
- transport_lun_remove_cmd(cmd);
}
if (aborted)
cmd->free_compl = &compl;
@@ -2794,6 +2766,9 @@ static void target_release_cmd_kref(struct kref *kref)
struct completion *abrt_compl = se_cmd->abrt_compl;
unsigned long flags;
+ if (se_cmd->lun_ref_active)
+ percpu_ref_put(&se_cmd->se_lun->lun_ref);
+
if (se_sess) {
spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);
list_del_init(&se_cmd->se_cmd_list);
--
2.20.1.495.gaa96b0ce6b-goog
