--- /dev/null
+From: Gerald Schaefer <geraldsc@de.ibm.com>
+Subject: zfcp: Send ELS ADISC from workqueue
+References: bnc#482818,LTC#51958
+
+Symptom: Remote port status change not handled
+ with high I/O load on other ports.
+Problem: The ELS ADISC command used for checking
+ the remote port status could not be sent
+ because of a full request queue.
+Solution: Move issing the ELS ADISC request to
+ a workqueue that can wait for a slot
+ in the request queue to become free.
+
+Acked-by: John Jolly <jjolly@suse.de>
+---
+ drivers/s390/scsi/zfcp_aux.c | 1 +
+ drivers/s390/scsi/zfcp_def.h | 1 +
+ drivers/s390/scsi/zfcp_ext.h | 1 +
+ drivers/s390/scsi/zfcp_fc.c | 28 ++++++++++++++++++----------
+ drivers/s390/scsi/zfcp_fsf.c | 18 ++++++------------
+ 5 files changed, 27 insertions(+), 22 deletions(-)
+
+--- a/drivers/s390/scsi/zfcp_aux.c
++++ b/drivers/s390/scsi/zfcp_aux.c
+@@ -611,6 +611,7 @@ struct zfcp_port *zfcp_port_enqueue(stru
+ init_waitqueue_head(&port->remove_wq);
+ INIT_LIST_HEAD(&port->unit_list_head);
+ INIT_WORK(&port->gid_pn_work, zfcp_erp_port_strategy_open_lookup);
++ INIT_WORK(&port->test_link_work, zfcp_fc_link_test_work);
+
+ port->adapter = adapter;
+ port->d_id = d_id;
+--- a/drivers/s390/scsi/zfcp_def.h
++++ b/drivers/s390/scsi/zfcp_def.h
+@@ -539,6 +539,7 @@ struct zfcp_port {
+ u32 maxframe_size;
+ u32 supported_classes;
+ struct work_struct gid_pn_work;
++ struct work_struct test_link_work;
+ };
+
+ struct zfcp_unit {
+--- a/drivers/s390/scsi/zfcp_ext.h
++++ b/drivers/s390/scsi/zfcp_ext.h
+@@ -101,6 +101,7 @@ extern void zfcp_fc_incoming_els(struct
+ extern int zfcp_fc_ns_gid_pn(struct zfcp_erp_action *);
+ extern void zfcp_fc_plogi_evaluate(struct zfcp_port *, struct fsf_plogi *);
+ extern void zfcp_test_link(struct zfcp_port *);
++extern void zfcp_fc_link_test_work(struct work_struct *);
+ extern void zfcp_fc_nameserver_init(struct zfcp_adapter *);
+
+ /* zfcp_fsf.c */
+--- a/drivers/s390/scsi/zfcp_fc.c
++++ b/drivers/s390/scsi/zfcp_fc.c
+@@ -415,19 +415,12 @@ static int zfcp_fc_adisc(struct zfcp_por
+ return zfcp_fsf_send_els(&adisc->els);
+ }
+
+-/**
+- * zfcp_test_link - lightweight link test procedure
+- * @port: port to be tested
+- *
+- * Test status of a link to a remote port using the ELS command ADISC.
+- * If there is a problem with the remote port, error recovery steps
+- * will be triggered.
+- */
+-void zfcp_test_link(struct zfcp_port *port)
++void zfcp_fc_link_test_work(struct work_struct *work)
+ {
++ struct zfcp_port *port =
++ container_of(work, struct zfcp_port, test_link_work);
+ int retval;
+
+- zfcp_port_get(port);
+ retval = zfcp_fc_adisc(port);
+ if (retval == 0)
+ return;
+@@ -438,6 +431,21 @@ void zfcp_test_link(struct zfcp_port *po
+ zfcp_erp_port_forced_reopen(port, 0, 65, NULL);
+ }
+
++/**
++ * zfcp_test_link - lightweight link test procedure
++ * @port: port to be tested
++ *
++ * Test status of a link to a remote port using the ELS command ADISC.
++ * If there is a problem with the remote port, error recovery steps
++ * will be triggered.
++ */
++void zfcp_test_link(struct zfcp_port *port)
++{
++ zfcp_port_get(port);
++ if (!queue_work(zfcp_data.work_queue, &port->test_link_work))
++ zfcp_port_put(port);
++}
++
+ static void zfcp_free_sg_env(struct zfcp_gpn_ft *gpn_ft, int buf_num)
+ {
+ struct scatterlist *sg = &gpn_ft->sg_req;
+--- a/drivers/s390/scsi/zfcp_fsf.c
++++ b/drivers/s390/scsi/zfcp_fsf.c
+@@ -654,14 +654,6 @@ static int zfcp_fsf_sbal_check(struct zf
+ return 0;
+ }
+
+-static int zfcp_fsf_sbal_available(struct zfcp_adapter *adapter)
+-{
+- unsigned int count = atomic_read(&adapter->req_q.count);
+- if (!count)
+- atomic_inc(&adapter->qdio_outb_full);
+- return count > 0;
+-}
+-
+ static int zfcp_fsf_req_sbal_get(struct zfcp_adapter *adapter)
+ {
+ long ret;
+@@ -1177,8 +1169,8 @@ int zfcp_fsf_send_els(struct zfcp_send_e
+ ZFCP_STATUS_COMMON_UNBLOCKED)))
+ return -EBUSY;
+
+- spin_lock(&adapter->req_q_lock);
+- if (!zfcp_fsf_sbal_available(adapter))
++ spin_lock_bh(&adapter->req_q_lock);
++ if (zfcp_fsf_req_sbal_get(adapter))
+ goto out;
+ req = zfcp_fsf_req_create(adapter, FSF_QTCB_SEND_ELS,
+ ZFCP_REQ_AUTO_CLEANUP, NULL);
+@@ -1211,7 +1203,7 @@ int zfcp_fsf_send_els(struct zfcp_send_e
+ failed_send:
+ zfcp_fsf_req_free(req);
+ out:
+- spin_unlock(&adapter->req_q_lock);
++ spin_unlock_bh(&adapter->req_q_lock);
+ return ret;
+ }
+
+@@ -2336,8 +2328,10 @@ int zfcp_fsf_send_fcp_command_task(struc
+ return -EBUSY;
+
+ spin_lock(&adapter->req_q_lock);
+- if (!zfcp_fsf_sbal_available(adapter))
++ if (atomic_read(&adapter->req_q.count) <= 0) {
++ atomic_inc(&adapter->qdio_outb_full);
+ goto out;
++ }
+ req = zfcp_fsf_req_create(adapter, FSF_QTCB_FCP_CMND, req_flags,
+ adapter->pool.fsf_req_scsi);
+ if (IS_ERR(req)) {
projects / people / pmueller / ipfire-2.x.git / blobdiff