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-rw-r--r--drivers/s390/scsi/zfcp_aux.c6
-rw-r--r--drivers/s390/scsi/zfcp_ccw.c32
-rw-r--r--drivers/s390/scsi/zfcp_def.h3
-rw-r--r--drivers/s390/scsi/zfcp_ext.h1
-rw-r--r--drivers/s390/scsi/zfcp_fc.c52
-rw-r--r--drivers/s390/scsi/zfcp_sysfs.c10
6 files changed, 90 insertions, 14 deletions
diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 8004b071a9f2..01a73395a017 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -353,9 +353,11 @@ struct zfcp_adapter *zfcp_adapter_enqueue(struct ccw_device *ccw_device)
adapter->ccw_device = ccw_device;
INIT_WORK(&adapter->stat_work, _zfcp_status_read_scheduler);
- INIT_WORK(&adapter->scan_work, zfcp_fc_scan_ports);
+ INIT_DELAYED_WORK(&adapter->scan_work, zfcp_fc_scan_ports);
INIT_WORK(&adapter->ns_up_work, zfcp_fc_sym_name_update);
+ adapter->next_port_scan = jiffies;
+
if (zfcp_qdio_setup(adapter))
goto failed;
@@ -420,7 +422,7 @@ void zfcp_adapter_unregister(struct zfcp_adapter *adapter)
{
struct ccw_device *cdev = adapter->ccw_device;
- cancel_work_sync(&adapter->scan_work);
+ cancel_delayed_work_sync(&adapter->scan_work);
cancel_work_sync(&adapter->stat_work);
cancel_work_sync(&adapter->ns_up_work);
zfcp_destroy_adapter_work_queue(adapter);
diff --git a/drivers/s390/scsi/zfcp_ccw.c b/drivers/s390/scsi/zfcp_ccw.c
index f9879d400d0e..54c7b48fdb46 100644
--- a/drivers/s390/scsi/zfcp_ccw.c
+++ b/drivers/s390/scsi/zfcp_ccw.c
@@ -56,8 +56,22 @@ static int zfcp_ccw_activate(struct ccw_device *cdev, int clear, char *tag)
zfcp_erp_set_adapter_status(adapter, ZFCP_STATUS_COMMON_RUNNING);
zfcp_erp_adapter_reopen(adapter, ZFCP_STATUS_COMMON_ERP_FAILED,
tag);
+
+ /*
+ * We want to scan ports here, with some random backoff and without
+ * rate limit. Recovery has already scheduled a port scan for us,
+ * but with both random delay and rate limit. Nevertheless we get
+ * what we want here by flushing the scheduled work after sleeping
+ * an equivalent random time.
+ * Let the port scan random delay elapse first. If recovery finishes
+ * up to that point in time, that would be perfect for both recovery
+ * and port scan. If not, i.e. recovery takes ages, there was no
+ * point in waiting a random delay on top of the time consumed by
+ * recovery.
+ */
+ msleep(zfcp_fc_port_scan_backoff());
zfcp_erp_wait(adapter);
- flush_work(&adapter->scan_work); /* ok to call even if nothing queued */
+ flush_delayed_work(&adapter->scan_work);
zfcp_ccw_adapter_put(adapter);
@@ -162,11 +176,19 @@ static int zfcp_ccw_set_online(struct ccw_device *cdev)
adapter->req_no = 0;
zfcp_ccw_activate(cdev, 0, "ccsonl1");
- /* scan for remote ports
- either at the end of any successful adapter recovery
- or only after the adapter recovery for setting a device online */
+
+ /*
+ * We want to scan ports here, always, with some random delay and
+ * without rate limit - basically what zfcp_ccw_activate() has
+ * achieved for us. Not quite! That port scan depended on
+ * !no_auto_port_rescan. So let's cover the no_auto_port_rescan
+ * case here to make sure a port scan is done unconditionally.
+ * Since zfcp_ccw_activate() has waited the desired random time,
+ * we can immediately schedule and flush a port scan for the
+ * remaining cases.
+ */
zfcp_fc_inverse_conditional_port_scan(adapter);
- flush_work(&adapter->scan_work); /* ok to call even if nothing queued */
+ flush_delayed_work(&adapter->scan_work);
zfcp_ccw_adapter_put(adapter);
return 0;
}
diff --git a/drivers/s390/scsi/zfcp_def.h b/drivers/s390/scsi/zfcp_def.h
index d91173f326c5..b8e853e53546 100644
--- a/drivers/s390/scsi/zfcp_def.h
+++ b/drivers/s390/scsi/zfcp_def.h
@@ -186,12 +186,13 @@ struct zfcp_adapter {
struct fc_host_statistics *fc_stats;
struct fsf_qtcb_bottom_port *stats_reset_data;
unsigned long stats_reset;
- struct work_struct scan_work;
+ struct delayed_work scan_work;
struct work_struct ns_up_work;
struct service_level service_level;
struct workqueue_struct *work_queue;
struct device_dma_parameters dma_parms;
struct zfcp_fc_events events;
+ unsigned long next_port_scan;
};
struct zfcp_port {
diff --git a/drivers/s390/scsi/zfcp_ext.h b/drivers/s390/scsi/zfcp_ext.h
index a9c570a09b85..5b500652572b 100644
--- a/drivers/s390/scsi/zfcp_ext.h
+++ b/drivers/s390/scsi/zfcp_ext.h
@@ -85,6 +85,7 @@ extern void zfcp_fc_gs_destroy(struct zfcp_adapter *);
extern int zfcp_fc_exec_bsg_job(struct fc_bsg_job *);
extern int zfcp_fc_timeout_bsg_job(struct fc_bsg_job *);
extern void zfcp_fc_sym_name_update(struct work_struct *);
+extern unsigned int zfcp_fc_port_scan_backoff(void);
extern void zfcp_fc_conditional_port_scan(struct zfcp_adapter *);
extern void zfcp_fc_inverse_conditional_port_scan(struct zfcp_adapter *);
diff --git a/drivers/s390/scsi/zfcp_fc.c b/drivers/s390/scsi/zfcp_fc.c
index ca28e1c66115..25d49f32ca63 100644
--- a/drivers/s390/scsi/zfcp_fc.c
+++ b/drivers/s390/scsi/zfcp_fc.c
@@ -12,6 +12,7 @@
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/utsname.h>
+#include <linux/random.h>
#include <scsi/fc/fc_els.h>
#include <scsi/libfc.h>
#include "zfcp_ext.h"
@@ -31,12 +32,54 @@ module_param_named(no_auto_port_rescan, no_auto_port_rescan, bool, 0600);
MODULE_PARM_DESC(no_auto_port_rescan,
"no automatic port_rescan (default off)");
+static unsigned int port_scan_backoff = 500;
+module_param(port_scan_backoff, uint, 0600);
+MODULE_PARM_DESC(port_scan_backoff,
+ "upper limit of port scan random backoff in msecs (default 500)");
+
+static unsigned int port_scan_ratelimit = 60000;
+module_param(port_scan_ratelimit, uint, 0600);
+MODULE_PARM_DESC(port_scan_ratelimit,
+ "minimum interval between port scans in msecs (default 60000)");
+
+unsigned int zfcp_fc_port_scan_backoff(void)
+{
+ if (!port_scan_backoff)
+ return 0;
+ return get_random_int() % port_scan_backoff;
+}
+
+static void zfcp_fc_port_scan_time(struct zfcp_adapter *adapter)
+{
+ unsigned long interval = msecs_to_jiffies(port_scan_ratelimit);
+ unsigned long backoff = msecs_to_jiffies(zfcp_fc_port_scan_backoff());
+
+ adapter->next_port_scan = jiffies + interval + backoff;
+}
+
+static void zfcp_fc_port_scan(struct zfcp_adapter *adapter)
+{
+ unsigned long now = jiffies;
+ unsigned long next = adapter->next_port_scan;
+ unsigned long delay = 0, max;
+
+ /* delay only needed within waiting period */
+ if (time_before(now, next)) {
+ delay = next - now;
+ /* paranoia: never ever delay scans longer than specified */
+ max = msecs_to_jiffies(port_scan_ratelimit + port_scan_backoff);
+ delay = min(delay, max);
+ }
+
+ queue_delayed_work(adapter->work_queue, &adapter->scan_work, delay);
+}
+
void zfcp_fc_conditional_port_scan(struct zfcp_adapter *adapter)
{
if (no_auto_port_rescan)
return;
- queue_work(adapter->work_queue, &adapter->scan_work);
+ zfcp_fc_port_scan(adapter);
}
void zfcp_fc_inverse_conditional_port_scan(struct zfcp_adapter *adapter)
@@ -44,7 +87,7 @@ void zfcp_fc_inverse_conditional_port_scan(struct zfcp_adapter *adapter)
if (!no_auto_port_rescan)
return;
- queue_work(adapter->work_queue, &adapter->scan_work);
+ zfcp_fc_port_scan(adapter);
}
/**
@@ -680,12 +723,15 @@ static int zfcp_fc_eval_gpn_ft(struct zfcp_fc_req *fc_req,
*/
void zfcp_fc_scan_ports(struct work_struct *work)
{
- struct zfcp_adapter *adapter = container_of(work, struct zfcp_adapter,
+ struct delayed_work *dw = to_delayed_work(work);
+ struct zfcp_adapter *adapter = container_of(dw, struct zfcp_adapter,
scan_work);
int ret, i;
struct zfcp_fc_req *fc_req;
int chain, max_entries, buf_num, max_bytes;
+ zfcp_fc_port_scan_time(adapter);
+
chain = adapter->adapter_features & FSF_FEATURE_ELS_CT_CHAINED_SBALS;
buf_num = chain ? ZFCP_FC_GPN_FT_NUM_BUFS : 1;
max_entries = chain ? ZFCP_FC_GPN_FT_MAX_ENT : ZFCP_FC_GPN_FT_ENT_PAGE;
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index a488c09f6e25..96a0be13e841 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -221,9 +221,13 @@ static ssize_t zfcp_sysfs_port_rescan_store(struct device *dev,
if (!adapter)
return -ENODEV;
- /* sync the user-space- with the kernel-invocation of scan_work */
- queue_work(adapter->work_queue, &adapter->scan_work);
- flush_work(&adapter->scan_work);
+ /*
+ * Users wish is our command: immediately schedule and flush a
+ * worker to conduct a synchronous port scan, that is, neither
+ * a random delay nor a rate limit is applied here.
+ */
+ queue_delayed_work(adapter->work_queue, &adapter->scan_work, 0);
+ flush_delayed_work(&adapter->scan_work);
zfcp_ccw_adapter_put(adapter);
return (ssize_t) count;