Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 7b2cc7dc authored by Bart Van Assche's avatar Bart Van Assche Committed by Martin K. Petersen
Browse files

scsi: target: Simplify the code for waiting for command completion 



Instead of embedding the completion that is used for waiting for command
completion in struct se_cmd, let the context that waits for command
completion allocate it. This makes it possible to have a single code path
for non-aborted and aborted commands in target_release_cmd_kref() and
avoids that transport_generic_free_cmd() has to call
cmd->se_tfo->release_cmd() directly. This patch does not change any
functionality. Note: transport_generic_free_cmd() only waits until the
se_cmd reference count has reached zero after it has set both
CMD_T_FABRIC_STOP and CMD_T_ABORTED.

Signed-off-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: default avatarMike Christie <mchristi@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent edf46eee

drivers/target/target_core_transport.c

+8 −16
Original line number Diff line number Diff line
@@ -1309,7 +1309,7 @@ void transport_init_se_cmd( 
	INIT_LIST_HEAD(&cmd->se_cmd_list);

	INIT_LIST_HEAD(&cmd->state_list);

	init_completion(&cmd->t_transport_stop_comp);

	init_completion(&cmd->cmd_wait_comp);

	cmd->compl = NULL;

	spin_lock_init(&cmd->t_state_lock);

	INIT_WORK(&cmd->work, NULL);

	kref_init(&cmd->cmd_kref);
@@ -2658,6 +2658,7 @@ static void target_wait_free_cmd(struct se_cmd *cmd, bool *aborted, bool *tas) 
 */

int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks)

{

	DECLARE_COMPLETION_ONSTACK(compl);

	int ret = 0;

	bool aborted = false, tas = false;
@@ -2676,12 +2677,13 @@ int transport_generic_free_cmd(struct se_cmd *cmd, int wait_for_tasks) 
		if (cmd->se_lun)

			transport_lun_remove_cmd(cmd);

	}

	if (aborted)

		cmd->compl = &compl;

	if (!aborted || tas)

		ret = target_put_sess_cmd(cmd);

	if (aborted) {

		pr_debug("Detected CMD_T_ABORTED for ITT: %llu\n", cmd->tag);

		wait_for_completion(&cmd->cmd_wait_comp);

		cmd->se_tfo->release_cmd(cmd);

		wait_for_completion(&compl);

		ret = 1;

	}

	return ret;
@@ -2742,31 +2744,21 @@ static void target_release_cmd_kref(struct kref *kref) 
{

	struct se_cmd *se_cmd = container_of(kref, struct se_cmd, cmd_kref);

	struct se_session *se_sess = se_cmd->se_sess;

	struct completion *compl = se_cmd->compl;

	unsigned long flags;

	bool fabric_stop;



	if (se_sess) {

		spin_lock_irqsave(&se_sess->sess_cmd_lock, flags);

		list_del_init(&se_cmd->se_cmd_list);

		if (list_empty(&se_sess->sess_cmd_list))

			wake_up(&se_sess->cmd_list_wq);



		spin_lock(&se_cmd->t_state_lock);

		fabric_stop = (se_cmd->transport_state & CMD_T_FABRIC_STOP) &&

			      (se_cmd->transport_state & CMD_T_ABORTED);

		spin_unlock(&se_cmd->t_state_lock);



		if (fabric_stop) {

			spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);

			target_free_cmd_mem(se_cmd);

			complete(&se_cmd->cmd_wait_comp);

			return;

		}

		spin_unlock_irqrestore(&se_sess->sess_cmd_lock, flags);

	}



	target_free_cmd_mem(se_cmd);

	se_cmd->se_tfo->release_cmd(se_cmd);

	if (compl)

		complete(compl);

}



/**

include/target/target_core_base.h

+1 −1
Original line number Diff line number Diff line
@@ -475,7 +475,7 @@ struct se_cmd { 
	struct se_session	*se_sess;

	struct se_tmr_req	*se_tmr_req;

	struct list_head	se_cmd_list;

	struct completion	cmd_wait_comp;

	struct completion	*compl;

	const struct target_core_fabric_ops *se_tfo;

	sense_reason_t		(*execute_cmd)(struct se_cmd *);

	sense_reason_t (*transport_complete_callback)(struct se_cmd *, bool, int *);