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.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Andy Grover <agrover@xxxxxxxxxx>
Cc: David Disseldorp <ddiss@xxxxxxx>
---
drivers/target/target_core_transport.c | 30 +++---------------------------
1 file changed, 3 insertions(+), 27 deletions(-)
diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 8df03987bdb8..99531dc85f9c 100644
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -598,11 +598,6 @@ 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
@@ -629,17 +624,6 @@ static int transport_cmd_check_stop_to_fabric(struct se_cmd *cmd)
: 0;
}
-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);
@@ -675,8 +659,6 @@ static void transport_handle_abort(struct se_cmd *cmd)
{
bool ack_kref = cmd->se_cmd_flags & SCF_ACK_KREF;
- transport_lun_remove_cmd(cmd);
-
if (cmd->send_abort_response) {
cmd->scsi_status = SAM_STAT_TASK_ABORTED;
pr_debug("Setting SAM_STAT_TASK_ABORTED status for CDB: 0x%02x, ITT: 0x%08llx\n",
@@ -1747,7 +1729,6 @@ 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;
@@ -2022,7 +2003,6 @@ static void transport_complete_qf(struct se_cmd *cmd)
transport_handle_queue_full(cmd, cmd->se_dev);
return;
}
- transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
}
@@ -2096,7 +2076,6 @@ static void target_complete_ok_work(struct work_struct *work)
if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
- transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
return;
}
@@ -2122,7 +2101,6 @@ static void target_complete_ok_work(struct work_struct *work)
if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
- transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
return;
}
@@ -2147,7 +2125,6 @@ static void target_complete_ok_work(struct work_struct *work)
if (ret == -EAGAIN || ret == -ENOMEM)
goto queue_full;
- transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
return;
}
@@ -2183,7 +2160,6 @@ static void target_complete_ok_work(struct work_struct *work)
break;
}
- transport_lun_remove_cmd(cmd);
transport_cmd_check_stop_to_fabric(cmd);
return;
@@ -2498,9 +2474,6 @@ 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);
}
/*
* Since the iSCSI and iSER targets driver assume that a SCSI command
@@ -2573,6 +2546,9 @@ static void target_release_cmd_kref(struct kref *kref)
WARN_ON_ONCE(atomic_read(&se_cmd->tgt_ref) != 0);
+ 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);
if (likely(!list_empty(&se_cmd->se_cmd_list))) {
--
2.11.0
--
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