On 2/26/22 3:04 PM, Mike Christie wrote:
> We currently allocate a workqueue per host and only use it for removing
> the target. For the session per host case we could be using this workqueue
> to be able to do recoveries (block, unblock, timeout handling) in
> parallel. To also allow offload drivers to do their session recoveries in
> parallel, this drops the per host workqueue and replaces it with a per
> session one.
>
> Signed-off-by: Mike Christie <michael.christie@xxxxxxxxxx>
> ---
> drivers/scsi/qla4xxx/ql4_os.c | 2 +-
> drivers/scsi/scsi_transport_iscsi.c | 19 ++++++++++++++-----
> include/scsi/scsi_transport_iscsi.h | 2 ++
> 3 files changed, 17 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/scsi/qla4xxx/ql4_os.c b/drivers/scsi/qla4xxx/ql4_os.c
> index 0ae936d839f1..955d8cb675f1 100644
> --- a/drivers/scsi/qla4xxx/ql4_os.c
> +++ b/drivers/scsi/qla4xxx/ql4_os.c
> @@ -5096,7 +5096,7 @@ int qla4xxx_unblock_flash_ddb(struct iscsi_cls_session *cls_session)
> ql4_printk(KERN_INFO, ha, "scsi%ld: %s: ddb[%d]"
> " start scan\n", ha->host_no, __func__,
> ddb_entry->fw_ddb_index);
> - scsi_queue_work(ha->host, &ddb_entry->sess->scan_work);
> + queue_work(ddb_entry->sess->workq, &ddb_entry->sess->scan_work);
> }
> return QLA_SUCCESS;
> }
> diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
> index 05cd4bca979e..ecb592a70e03 100644
> --- a/drivers/scsi/scsi_transport_iscsi.c
> +++ b/drivers/scsi/scsi_transport_iscsi.c
> @@ -2032,19 +2032,27 @@ EXPORT_SYMBOL_GPL(iscsi_alloc_session);
>
> int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
> {
> + struct Scsi_Host *shost = iscsi_session_to_shost(session);
> unsigned long flags;
> int id = 0;
> int err;
>
> session->sid = atomic_add_return(1, &iscsi_session_nr);
>
> + session->workq = alloc_workqueue("iscsi_ctrl_%d:%d",
> + WQ_SYSFS | WQ_MEM_RECLAIM | WQ_UNBOUND, 0,
> + shost->host_no, session->sid);
> + if (!session->workq)
> + return -ENOMEM;
> +
> if (target_id == ISCSI_MAX_TARGET) {
> id = ida_simple_get(&iscsi_sess_ida, 0, 0, GFP_KERNEL);
>
> if (id < 0) {
> iscsi_cls_session_printk(KERN_ERR, session,
> "Failure in Target ID Allocation\n");
> - return id;
> + err = id;
> + goto destroy_wq;
> }
> session->target_id = (unsigned int)id;
> session->ida_used = true;
> @@ -2078,7 +2086,8 @@ int iscsi_add_session(struct iscsi_cls_session *session, unsigned int target_id)
> release_ida:
> if (session->ida_used)
> ida_simple_remove(&iscsi_sess_ida, session->target_id);
> -
> +destroy_wq:
> + destroy_workqueue(session->workq);
> return err;
> }
> EXPORT_SYMBOL_GPL(iscsi_add_session);
> @@ -2177,6 +2186,8 @@ void iscsi_remove_session(struct iscsi_cls_session *session)
>
> transport_unregister_device(&session->dev);
>
> + destroy_workqueue(session->workq);
> +
> ISCSI_DBG_TRANS_SESSION(session, "Completing session removal\n");
> device_del(&session->dev);
> }
> @@ -3833,8 +3844,7 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group)
> case ISCSI_UEVENT_UNBIND_SESSION:
> session = iscsi_session_lookup(ev->u.d_session.sid);
> if (session)
> - scsi_queue_work(iscsi_session_to_shost(session),
> - &session->unbind_work);
> + queue_work(session->workq, &session->unbind_work);
> else
> err = -EINVAL;
> break;
> @@ -4707,7 +4717,6 @@ iscsi_register_transport(struct iscsi_transport *tt)
> INIT_LIST_HEAD(&priv->list);
> priv->iscsi_transport = tt;
> priv->t.user_scan = iscsi_user_scan;
> - priv->t.create_work_queue = 1;
>
> priv->dev.class = &iscsi_transport_class;
> dev_set_name(&priv->dev, "%s", tt->name);
> diff --git a/include/scsi/scsi_transport_iscsi.h b/include/scsi/scsi_transport_iscsi.h
> index 90b55db46d7c..7a0d24d3b916 100644
> --- a/include/scsi/scsi_transport_iscsi.h
> +++ b/include/scsi/scsi_transport_iscsi.h
> @@ -251,6 +251,8 @@ struct iscsi_cls_session {
> bool recovery_tmo_sysfs_override;
> struct delayed_work recovery_work;
>
> + struct workqueue_struct *workq;
> +
> unsigned int target_id;
> bool ida_used;
>
Reviewed-by: Chris Leech <cleech@xxxxxxxxxx>
