Commit ad515cad authored by Wenchao Hao's avatar Wenchao Hao Committed by Martin K. Petersen
Browse files

scsi: iscsi: Add helper functions to manage iscsi_cls_conn 

 - iscsi_alloc_conn(): Allocate and initialize iscsi_cls_conn

 - iscsi_add_conn(): Expose iscsi_cls_conn to userspace via sysfs

 - iscsi_remove_conn(): Remove iscsi_cls_conn from sysfs

Link: https://lore.kernel.org/r/20220310015759.3296841-2-haowenchao@huawei.com


Reviewed-by: default avatarMike Christie <michael.christie@oracle.com>
Signed-off-by: default avatarWenchao Hao <haowenchao@huawei.com>
Signed-off-by: default avatarWu Bo <wubo40@huawei.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent e1b353e7

drivers/scsi/scsi_transport_iscsi.c

+97 −0
Original line number Diff line number Diff line
@@ -2317,6 +2317,103 @@ void iscsi_free_session(struct iscsi_cls_session *session) 
}

EXPORT_SYMBOL_GPL(iscsi_free_session);



/**

 * iscsi_alloc_conn - alloc iscsi class connection

 * @session: iscsi cls session

 * @dd_size: private driver data size

 * @cid: connection id

 */

struct iscsi_cls_conn *

iscsi_alloc_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid)

{

	struct iscsi_transport *transport = session->transport;

	struct iscsi_cls_conn *conn;



	conn = kzalloc(sizeof(*conn) + dd_size, GFP_KERNEL);

	if (!conn)

		return NULL;

	if (dd_size)

		conn->dd_data = &conn[1];



	mutex_init(&conn->ep_mutex);

	INIT_LIST_HEAD(&conn->conn_list);

	INIT_WORK(&conn->cleanup_work, iscsi_cleanup_conn_work_fn);

	conn->transport = transport;

	conn->cid = cid;

	conn->state = ISCSI_CONN_DOWN;



	/* this is released in the dev's release function */

	if (!get_device(&session->dev))

		goto free_conn;



	dev_set_name(&conn->dev, "connection%d:%u", session->sid, cid);

	device_initialize(&conn->dev);

	conn->dev.parent = &session->dev;

	conn->dev.release = iscsi_conn_release;



	return conn;



free_conn:

	kfree(conn);

	return NULL;

}

EXPORT_SYMBOL_GPL(iscsi_alloc_conn);



/**

 * iscsi_add_conn - add iscsi class connection

 * @conn: iscsi cls connection

 *

 * This will expose iscsi_cls_conn to sysfs so make sure the related

 * resources for sysfs attributes are initialized before calling this.

 */

int iscsi_add_conn(struct iscsi_cls_conn *conn)

{

	int err;

	unsigned long flags;

	struct iscsi_cls_session *session = iscsi_dev_to_session(conn->dev.parent);



	err = device_add(&conn->dev);

	if (err) {

		iscsi_cls_session_printk(KERN_ERR, session,

					 "could not register connection's dev\n");

		return err;

	}

	err = transport_register_device(&conn->dev);

	if (err) {

		iscsi_cls_session_printk(KERN_ERR, session,

					 "could not register transport's dev\n");

		device_del(&conn->dev);

		return err;

	}



	spin_lock_irqsave(&connlock, flags);

	list_add(&conn->conn_list, &connlist);

	spin_unlock_irqrestore(&connlock, flags);



	return 0;

}

EXPORT_SYMBOL_GPL(iscsi_add_conn);



/**

 * iscsi_remove_conn - remove iscsi class connection from sysfs

 * @conn: iscsi cls connection

 *

 * Remove iscsi_cls_conn from sysfs, and wait for previous

 * read/write of iscsi_cls_conn's attributes in sysfs to finish.

 */

void iscsi_remove_conn(struct iscsi_cls_conn *conn)

{

	unsigned long flags;



	spin_lock_irqsave(&connlock, flags);

	list_del(&conn->conn_list);

	spin_unlock_irqrestore(&connlock, flags);



	transport_unregister_device(&conn->dev);

	device_del(&conn->dev);

}

EXPORT_SYMBOL_GPL(iscsi_remove_conn);



/**

 * iscsi_create_conn - create iscsi class connection

 * @session: iscsi cls session

include/scsi/scsi_transport_iscsi.h

+4 −0
Original line number Diff line number Diff line
@@ -442,6 +442,10 @@ extern struct iscsi_cls_session *iscsi_create_session(struct Scsi_Host *shost, 
						unsigned int target_id);

extern void iscsi_remove_session(struct iscsi_cls_session *session);

extern void iscsi_free_session(struct iscsi_cls_session *session);

extern struct iscsi_cls_conn *iscsi_alloc_conn(struct iscsi_cls_session *sess,

						int dd_size, uint32_t cid);

extern int iscsi_add_conn(struct iscsi_cls_conn *conn);

extern void iscsi_remove_conn(struct iscsi_cls_conn *conn);

extern struct iscsi_cls_conn *iscsi_create_conn(struct iscsi_cls_session *sess,

						int dd_size, uint32_t cid);

extern void iscsi_put_conn(struct iscsi_cls_conn *conn);