Merge remote-tracking branch 'scsi-queue/drivers-for-3.19' into for-linus

Conflicts:
	drivers/scsi/scsi_debug.c

Agreed and tested resolution to a merge problem between a fix in scsi_debug
and a driver update

Signed-off-by: James Bottomley <JBottomley@Parallels.com>

9 files changed, 144 insertions, 50 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_erp.c b/drivers/s390/scsi/zfcp_erp.c
index c82fe65c4128..2c5d4567d1da 100644
--- a/drivers/s390/scsi/zfcp_erp.c
+++ b/drivers/s390/scsi/zfcp_erp.c
@@ -821,11 +821,6 @@ static int zfcp_erp_port_forced_strategy_close(struct zfcp_erp_action *act)
 	return ZFCP_ERP_CONTINUES;
 }
 
-static void zfcp_erp_port_strategy_clearstati(struct zfcp_port *port)
-{
-	atomic_clear_mask(ZFCP_STATUS_COMMON_ACCESS_DENIED, &port->status);
-}
-
 static int zfcp_erp_port_forced_strategy(struct zfcp_erp_action *erp_action)
 {
 	struct zfcp_port *port = erp_action->port;
@@ -833,7 +828,6 @@ static int zfcp_erp_port_forced_strategy(struct zfcp_erp_action *erp_action)
 
 	switch (erp_action->step) {
 	case ZFCP_ERP_STEP_UNINITIALIZED:
-		zfcp_erp_port_strategy_clearstati(port);
 		if ((status & ZFCP_STATUS_PORT_PHYS_OPEN) &&
 		    (status & ZFCP_STATUS_COMMON_OPEN))
 			return zfcp_erp_port_forced_strategy_close(erp_action);
@@ -933,7 +927,6 @@ static int zfcp_erp_port_strategy(struct zfcp_erp_action *erp_action)
 
 	switch (erp_action->step) {
 	case ZFCP_ERP_STEP_UNINITIALIZED:
-		zfcp_erp_port_strategy_clearstati(port);
 		if (p_status & ZFCP_STATUS_COMMON_OPEN)
 			return zfcp_erp_port_strategy_close(erp_action);
 		break;
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_fsf.c b/drivers/s390/scsi/zfcp_fsf.c
index 0fe8d5d95119..21ec5e2f584c 100644
--- a/drivers/s390/scsi/zfcp_fsf.c
+++ b/drivers/s390/scsi/zfcp_fsf.c
@@ -1396,8 +1396,7 @@ static void zfcp_fsf_open_port_handler(struct zfcp_fsf_req *req)
 		port->handle = header->port_handle;
 		atomic_set_mask(ZFCP_STATUS_COMMON_OPEN |
 				ZFCP_STATUS_PORT_PHYS_OPEN, &port->status);
-		atomic_clear_mask(ZFCP_STATUS_COMMON_ACCESS_DENIED |
-		                  ZFCP_STATUS_COMMON_ACCESS_BOXED,
+		atomic_clear_mask(ZFCP_STATUS_COMMON_ACCESS_BOXED,
 		                  &port->status);
 		/* check whether D_ID has changed during open */
 		/*
diff --git a/drivers/s390/scsi/zfcp_scsi.c b/drivers/s390/scsi/zfcp_scsi.c
index b5dfa51f396f..75f4bfc2b98a 100644
--- a/drivers/s390/scsi/zfcp_scsi.c
+++ b/drivers/s390/scsi/zfcp_scsi.c
@@ -32,25 +32,6 @@ static bool allow_lun_scan = 1;
 module_param(allow_lun_scan, bool, 0600);
 MODULE_PARM_DESC(allow_lun_scan, "For NPIV, scan and attach all storage LUNs");
 
-static int zfcp_scsi_change_queue_depth(struct scsi_device *sdev, int depth,
-					int reason)
-{
-	switch (reason) {
-	case SCSI_QDEPTH_DEFAULT:
-		scsi_adjust_queue_depth(sdev, depth);
-		break;
-	case SCSI_QDEPTH_QFULL:
-		scsi_track_queue_full(sdev, depth);
-		break;
-	case SCSI_QDEPTH_RAMP_UP:
-		scsi_adjust_queue_depth(sdev, depth);
-		break;
-	default:
-		return -EOPNOTSUPP;
-	}
-	return sdev->queue_depth;
-}
-
 static void zfcp_scsi_slave_destroy(struct scsi_device *sdev)
 {
 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);
@@ -66,7 +47,7 @@ static void zfcp_scsi_slave_destroy(struct scsi_device *sdev)
 static int zfcp_scsi_slave_configure(struct scsi_device *sdp)
 {
 	if (sdp->tagged_supported)
-		scsi_adjust_queue_depth(sdp, default_depth);
+		scsi_change_queue_depth(sdp, default_depth);
 	return 0;
 }
 
@@ -305,7 +286,7 @@ static struct scsi_host_template zfcp_scsi_host_template = {
 	.slave_alloc		 = zfcp_scsi_slave_alloc,
 	.slave_configure	 = zfcp_scsi_slave_configure,
 	.slave_destroy		 = zfcp_scsi_slave_destroy,
-	.change_queue_depth	 = zfcp_scsi_change_queue_depth,
+	.change_queue_depth	 = scsi_change_queue_depth,
 	.proc_name		 = "zfcp",
 	.can_queue		 = 4096,
 	.this_id		 = -1,
@@ -320,6 +301,7 @@ static struct scsi_host_template zfcp_scsi_host_template = {
 	.use_clustering		 = 1,
 	.shost_attrs		 = zfcp_sysfs_shost_attrs,
 	.sdev_attrs		 = zfcp_sysfs_sdev_attrs,
+	.track_queue_depth	 = 1,
 };
 
 /**
diff --git a/drivers/s390/scsi/zfcp_sysfs.c b/drivers/s390/scsi/zfcp_sysfs.c
index 672b57219e11..96a0be13e841 100644
--- a/drivers/s390/scsi/zfcp_sysfs.c
+++ b/drivers/s390/scsi/zfcp_sysfs.c
@@ -73,9 +73,7 @@ ZFCP_DEFINE_ATTR(zfcp_port, port, status, "0x%08x\n",
 ZFCP_DEFINE_ATTR(zfcp_port, port, in_recovery, "%d\n",
 		 (atomic_read(&port->status) &
 		  ZFCP_STATUS_COMMON_ERP_INUSE) != 0);
-ZFCP_DEFINE_ATTR(zfcp_port, port, access_denied, "%d\n",
-		 (atomic_read(&port->status) &
-		  ZFCP_STATUS_COMMON_ACCESS_DENIED) != 0);
+ZFCP_DEFINE_ATTR_CONST(port, access_denied, "%d\n", 0);
 
 ZFCP_DEFINE_ATTR(zfcp_unit, unit, status, "0x%08x\n",
 		 zfcp_unit_sdev_status(unit));
@@ -223,9 +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;
@@ -439,16 +441,15 @@ static ssize_t zfcp_sysfs_scsi_##_name##_show(struct device *dev,	\
 {                                                                        \
 	struct scsi_device *sdev = to_scsi_device(dev);			 \
 	struct zfcp_scsi_dev *zfcp_sdev = sdev_to_zfcp(sdev);		 \
-	struct zfcp_port *port = zfcp_sdev->port;			 \
 									 \
 	return sprintf(buf, _format, _value);                            \
 }                                                                        \
 static DEVICE_ATTR(_name, S_IRUGO, zfcp_sysfs_scsi_##_name##_show, NULL);
 
 ZFCP_DEFINE_SCSI_ATTR(hba_id, "%s\n",
-		      dev_name(&port->adapter->ccw_device->dev));
+		      dev_name(&zfcp_sdev->port->adapter->ccw_device->dev));
 ZFCP_DEFINE_SCSI_ATTR(wwpn, "0x%016llx\n",
-		      (unsigned long long) port->wwpn);
+		      (unsigned long long) zfcp_sdev->port->wwpn);
 
 static ssize_t zfcp_sysfs_scsi_fcp_lun_show(struct device *dev,
 					    struct device_attribute *attr,
@@ -460,6 +461,49 @@ static ssize_t zfcp_sysfs_scsi_fcp_lun_show(struct device *dev,
 }
 static DEVICE_ATTR(fcp_lun, S_IRUGO, zfcp_sysfs_scsi_fcp_lun_show, NULL);
 
+ZFCP_DEFINE_SCSI_ATTR(zfcp_access_denied, "%d\n",
+		      (atomic_read(&zfcp_sdev->status) &
+		       ZFCP_STATUS_COMMON_ACCESS_DENIED) != 0);
+
+static ssize_t zfcp_sysfs_scsi_zfcp_failed_show(struct device *dev,
+					   struct device_attribute *attr,
+					   char *buf)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	unsigned int status = atomic_read(&sdev_to_zfcp(sdev)->status);
+	unsigned int failed = status & ZFCP_STATUS_COMMON_ERP_FAILED ? 1 : 0;
+
+	return sprintf(buf, "%d\n", failed);
+}
+
+static ssize_t zfcp_sysfs_scsi_zfcp_failed_store(struct device *dev,
+					    struct device_attribute *attr,
+					    const char *buf, size_t count)
+{
+	struct scsi_device *sdev = to_scsi_device(dev);
+	unsigned long val;
+
+	if (kstrtoul(buf, 0, &val) || val != 0)
+		return -EINVAL;
+
+	zfcp_erp_set_lun_status(sdev, ZFCP_STATUS_COMMON_RUNNING);
+	zfcp_erp_lun_reopen(sdev, ZFCP_STATUS_COMMON_ERP_FAILED,
+			    "syufai3");
+	zfcp_erp_wait(sdev_to_zfcp(sdev)->port->adapter);
+
+	return count;
+}
+static DEVICE_ATTR(zfcp_failed, S_IWUSR | S_IRUGO,
+		   zfcp_sysfs_scsi_zfcp_failed_show,
+		   zfcp_sysfs_scsi_zfcp_failed_store);
+
+ZFCP_DEFINE_SCSI_ATTR(zfcp_in_recovery, "%d\n",
+		      (atomic_read(&zfcp_sdev->status) &
+		       ZFCP_STATUS_COMMON_ERP_INUSE) != 0);
+
+ZFCP_DEFINE_SCSI_ATTR(zfcp_status, "0x%08x\n",
+		      atomic_read(&zfcp_sdev->status));
+
 struct device_attribute *zfcp_sysfs_sdev_attrs[] = {
 	&dev_attr_fcp_lun,
 	&dev_attr_wwpn,
@@ -467,6 +511,10 @@ struct device_attribute *zfcp_sysfs_sdev_attrs[] = {
 	&dev_attr_read_latency,
 	&dev_attr_write_latency,
 	&dev_attr_cmd_latency,
+	&dev_attr_zfcp_access_denied,
+	&dev_attr_zfcp_failed,
+	&dev_attr_zfcp_in_recovery,
+	&dev_attr_zfcp_status,
 	NULL
 };