diff options
Diffstat (limited to 'drivers/scsi/scsi_transport_iscsi.c')
| -rw-r--r-- | drivers/scsi/scsi_transport_iscsi.c | 139 |
1 files changed, 137 insertions, 2 deletions
diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c index dfc726fa34e3..b2a803c51288 100644 --- a/drivers/scsi/scsi_transport_iscsi.c +++ b/drivers/scsi/scsi_transport_iscsi.c @@ -86,9 +86,17 @@ struct iscsi_internal { struct transport_container session_cont; }; +/* Worker to perform connection failure on unresponsive connections + * completely in kernel space. + */ +static void stop_conn_work_fn(struct work_struct *work); +static DECLARE_WORK(stop_conn_work, stop_conn_work_fn); + static atomic_t iscsi_session_nr; /* sysfs session id for next new session */ static struct workqueue_struct *iscsi_eh_timer_workq; +static struct workqueue_struct *iscsi_destroy_workq; + static DEFINE_IDA(iscsi_sess_ida); /* * list of registered transports and lock that must @@ -1609,8 +1617,10 @@ static struct sock *nls; static DEFINE_MUTEX(rx_queue_mutex); static LIST_HEAD(sesslist); +static LIST_HEAD(sessdestroylist); static DEFINE_SPINLOCK(sesslock); static LIST_HEAD(connlist); +static LIST_HEAD(connlist_err); static DEFINE_SPINLOCK(connlock); static uint32_t iscsi_conn_get_sid(struct iscsi_cls_conn *conn) @@ -2012,7 +2022,7 @@ static void __iscsi_unbind_session(struct work_struct *work) if (session->target_id == ISCSI_MAX_TARGET) { spin_unlock_irqrestore(&session->lock, flags); mutex_unlock(&ihost->mutex); - return; + goto unbind_session_exit; } target_id = session->target_id; @@ -2024,10 +2034,20 @@ static void __iscsi_unbind_session(struct work_struct *work) ida_simple_remove(&iscsi_sess_ida, target_id); scsi_remove_target(&session->dev); + +unbind_session_exit: iscsi_session_event(session, ISCSI_KEVENT_UNBIND_SESSION); ISCSI_DBG_TRANS_SESSION(session, "Completed target removal\n"); } +static void __iscsi_destroy_session(struct work_struct *work) +{ + struct iscsi_cls_session *session = + container_of(work, struct iscsi_cls_session, destroy_work); + + session->transport->destroy_session(session); +} + struct iscsi_cls_session * iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport, int dd_size) @@ -2050,6 +2070,7 @@ iscsi_alloc_session(struct Scsi_Host *shost, struct iscsi_transport *transport, INIT_WORK(&session->block_work, __iscsi_block_session); INIT_WORK(&session->unbind_work, __iscsi_unbind_session); INIT_WORK(&session->scan_work, iscsi_scan_session); + INIT_WORK(&session->destroy_work, __iscsi_destroy_session); spin_lock_init(&session->lock); /* this is released in the dev's release function */ @@ -2254,8 +2275,10 @@ iscsi_create_conn(struct iscsi_cls_session *session, int dd_size, uint32_t cid) mutex_init(&conn->ep_mutex); INIT_LIST_HEAD(&conn->conn_list); + INIT_LIST_HEAD(&conn->conn_list_err); 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)) @@ -2307,6 +2330,7 @@ int iscsi_destroy_conn(struct iscsi_cls_conn *conn) spin_lock_irqsave(&connlock, flags); list_del(&conn->conn_list); + list_del(&conn->conn_list_err); spin_unlock_irqrestore(&connlock, flags); transport_unregister_device(&conn->dev); @@ -2421,6 +2445,51 @@ int iscsi_offload_mesg(struct Scsi_Host *shost, } EXPORT_SYMBOL_GPL(iscsi_offload_mesg); +static void stop_conn_work_fn(struct work_struct *work) +{ + struct iscsi_cls_conn *conn, *tmp; + unsigned long flags; + LIST_HEAD(recovery_list); + + spin_lock_irqsave(&connlock, flags); + if (list_empty(&connlist_err)) { + spin_unlock_irqrestore(&connlock, flags); + return; + } + list_splice_init(&connlist_err, &recovery_list); + spin_unlock_irqrestore(&connlock, flags); + + list_for_each_entry_safe(conn, tmp, &recovery_list, conn_list_err) { + uint32_t sid = iscsi_conn_get_sid(conn); + struct iscsi_cls_session *session; + + mutex_lock(&rx_queue_mutex); + + session = iscsi_session_lookup(sid); + if (session) { + if (system_state != SYSTEM_RUNNING) { + session->recovery_tmo = 0; + conn->transport->stop_conn(conn, + STOP_CONN_TERM); + } else { + conn->transport->stop_conn(conn, + STOP_CONN_RECOVER); + } + } + + list_del_init(&conn->conn_list_err); + + mutex_unlock(&rx_queue_mutex); + + /* we don't want to hold rx_queue_mutex for too long, + * for instance if many conns failed at the same time, + * since this stall other iscsi maintenance operations. + * Give other users a chance to proceed. + */ + cond_resched(); + } +} + void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error) { struct nlmsghdr *nlh; @@ -2428,6 +2497,12 @@ void iscsi_conn_error_event(struct iscsi_cls_conn *conn, enum iscsi_err error) struct iscsi_uevent *ev; struct iscsi_internal *priv; int len = nlmsg_total_size(sizeof(*ev)); + unsigned long flags; + + spin_lock_irqsave(&connlock, flags); + list_add(&conn->conn_list_err, &connlist_err); + spin_unlock_irqrestore(&connlock, flags); + queue_work(system_unbound_wq, &stop_conn_work); priv = iscsi_if_transport_lookup(conn->transport); if (!priv) @@ -2757,11 +2832,19 @@ static int iscsi_if_destroy_conn(struct iscsi_transport *transport, struct iscsi_uevent *ev) { struct iscsi_cls_conn *conn; + unsigned long flags; conn = iscsi_conn_lookup(ev->u.d_conn.sid, ev->u.d_conn.cid); if (!conn) return -EINVAL; + spin_lock_irqsave(&connlock, flags); + if (!list_empty(&conn->conn_list_err)) { + spin_unlock_irqrestore(&connlock, flags); + return -EAGAIN; + } + spin_unlock_irqrestore(&connlock, flags); + ISCSI_DBG_TRANS_CONN(conn, "Destroying transport conn\n"); if (transport->destroy_conn) transport->destroy_conn(conn); @@ -3563,6 +3646,23 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group) else transport->destroy_session(session); break; + case ISCSI_UEVENT_DESTROY_SESSION_ASYNC: + session = iscsi_session_lookup(ev->u.d_session.sid); + if (!session) + err = -EINVAL; + else if (iscsi_session_has_conns(ev->u.d_session.sid)) + err = -EBUSY; + else { + unsigned long flags; + + /* Prevent this session from being found again */ + spin_lock_irqsave(&sesslock, flags); + list_move(&session->sess_list, &sessdestroylist); + spin_unlock_irqrestore(&sesslock, flags); + + queue_work(iscsi_destroy_workq, &session->destroy_work); + } + break; case ISCSI_UEVENT_UNBIND_SESSION: session = iscsi_session_lookup(ev->u.d_session.sid); if (session) @@ -3612,8 +3712,11 @@ iscsi_if_recv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, uint32_t *group) break; case ISCSI_UEVENT_START_CONN: conn = iscsi_conn_lookup(ev->u.start_conn.sid, ev->u.start_conn.cid); - if (conn) + if (conn) { ev->r.retcode = transport->start_conn(conn); + if (!ev->r.retcode) + conn->state = ISCSI_CONN_UP; + } else err = -EINVAL; break; @@ -3810,6 +3913,26 @@ iscsi_conn_attr(tcp_xmit_wsf, ISCSI_PARAM_TCP_XMIT_WSF); iscsi_conn_attr(tcp_recv_wsf, ISCSI_PARAM_TCP_RECV_WSF); iscsi_conn_attr(local_ipaddr, ISCSI_PARAM_LOCAL_IPADDR); +static const char *const connection_state_names[] = { + [ISCSI_CONN_UP] = "up", + [ISCSI_CONN_DOWN] = "down", + [ISCSI_CONN_FAILED] = "failed" +}; + +static ssize_t show_conn_state(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent); + const char *state = "unknown"; + + if (conn->state >= 0 && + conn->state < ARRAY_SIZE(connection_state_names)) + state = connection_state_names[conn->state]; + + return sprintf(buf, "%s\n", state); +} +static ISCSI_CLASS_ATTR(conn, state, S_IRUGO, show_conn_state, + NULL); #define iscsi_conn_ep_attr_show(param) \ static ssize_t show_conn_ep_param_##param(struct device *dev, \ @@ -3879,6 +4002,7 @@ static struct attribute *iscsi_conn_attrs[] = { &dev_attr_conn_tcp_xmit_wsf.attr, &dev_attr_conn_tcp_recv_wsf.attr, &dev_attr_conn_local_ipaddr.attr, + &dev_attr_conn_state.attr, NULL, }; @@ -3950,6 +4074,8 @@ static umode_t iscsi_conn_attr_is_visible(struct kobject *kobj, param = ISCSI_PARAM_TCP_RECV_WSF; else if (attr == &dev_attr_conn_local_ipaddr.attr) param = ISCSI_PARAM_LOCAL_IPADDR; + else if (attr == &dev_attr_conn_state.attr) + return S_IRUGO; else { WARN_ONCE(1, "Invalid conn attr"); return 0; @@ -4608,8 +4734,16 @@ static __init int iscsi_transport_init(void) goto release_nls; } + iscsi_destroy_workq = create_singlethread_workqueue("iscsi_destroy"); + if (!iscsi_destroy_workq) { + err = -ENOMEM; + goto destroy_wq; + } + return 0; +destroy_wq: + destroy_workqueue(iscsi_eh_timer_workq); release_nls: netlink_kernel_release(nls); unregister_flashnode_bus: @@ -4631,6 +4765,7 @@ unregister_transport_class: static void __exit iscsi_transport_exit(void) { + destroy_workqueue(iscsi_destroy_workq); destroy_workqueue(iscsi_eh_timer_workq); netlink_kernel_release(nls); bus_unregister(&iscsi_flashnode_bus); |