[PATCH v2 7/8] scsi_transport_fc: Added a new sysfs attribute port_state

[Muneendra <muneendra.kumar@broadcom.com>]

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Added a new sysfs attribute port_state under fc_transport/target*/

With this new interface the user can move the port_state from
Marginal -> Online and Online->Marginal.

On Marginal :This interface will set SCMD_NORETRIES_ABORT bit in
scmd->state for all the pending io's on the scsi device associated
with target port.

On Online :This interface will clear SCMD_NORETRIES_ABORT bit in
scmd->state for all the pending io's on the scsi device associated
with target port.

Below is the interface provided to set the port state to Marginal
and Online.

echo "Marginal" >> /sys/class/fc_transport/targetX\:Y\:Z/port_state
echo "Online" >> /sys/class/fc_transport/targetX\:Y\:Z/port_state

Also made changes in fc_remote_port_delete,fc_user_scan_tgt,
fc_timeout_deleted_rport functions  to handle the new rport state
FC_PORTSTATE_MARGINAL.

Signed-off-by: Muneendra <muneendra.kumar@broadcom.com>

---
v2:
Changed from a noretries_abort attribute under fc_transport/target*/ to
port_state for changing the port_state to a marginal state
---
 drivers/scsi/scsi_transport_fc.c | 140 +++++++++++++++++++++++++++----
 1 file changed, 122 insertions(+), 18 deletions(-)

diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 2ff7f06203da..6fe2463c5a68 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -142,20 +142,23 @@ fc_enum_name_search(host_event_code, fc_host_event_code,
 static struct {
 	enum fc_port_state	value;
 	char			*name;
+	int			matchlen;
 } fc_port_state_names[] = {
-	{ FC_PORTSTATE_UNKNOWN,		"Unknown" },
-	{ FC_PORTSTATE_NOTPRESENT,	"Not Present" },
-	{ FC_PORTSTATE_ONLINE,		"Online" },
-	{ FC_PORTSTATE_OFFLINE,		"Offline" },
-	{ FC_PORTSTATE_BLOCKED,		"Blocked" },
-	{ FC_PORTSTATE_BYPASSED,	"Bypassed" },
-	{ FC_PORTSTATE_DIAGNOSTICS,	"Diagnostics" },
-	{ FC_PORTSTATE_LINKDOWN,	"Linkdown" },
-	{ FC_PORTSTATE_ERROR,		"Error" },
-	{ FC_PORTSTATE_LOOPBACK,	"Loopback" },
-	{ FC_PORTSTATE_DELETED,		"Deleted" },
+	{ FC_PORTSTATE_UNKNOWN,		"Unknown", 7},
+	{ FC_PORTSTATE_NOTPRESENT,	"Not Present", 11 },
+	{ FC_PORTSTATE_ONLINE,		"Online", 6 },
+	{ FC_PORTSTATE_OFFLINE,		"Offline", 7 },
+	{ FC_PORTSTATE_BLOCKED,		"Blocked", 7 },
+	{ FC_PORTSTATE_BYPASSED,	"Bypassed", 8 },
+	{ FC_PORTSTATE_DIAGNOSTICS,	"Diagnostics", 11 },
+	{ FC_PORTSTATE_LINKDOWN,	"Linkdown", 8 },
+	{ FC_PORTSTATE_ERROR,		"Error", 5 },
+	{ FC_PORTSTATE_LOOPBACK,	"Loopback", 8 },
+	{ FC_PORTSTATE_DELETED,		"Deleted", 7 },
+	{ FC_PORTSTATE_MARGINAL,	"Marginal", 8 },
 };
 fc_enum_name_search(port_state, fc_port_state, fc_port_state_names)
+fc_enum_name_match(port_state, fc_port_state, fc_port_state_names)
 #define FC_PORTSTATE_MAX_NAMELEN	20
 
 
@@ -306,7 +309,7 @@ static void fc_scsi_scan_rport(struct work_struct *work);
  * Attribute counts pre object type...
  * Increase these values if you add attributes
  */
-#define FC_STARGET_NUM_ATTRS 	3
+#define FC_STARGET_NUM_ATTRS	4
 #define FC_RPORT_NUM_ATTRS	10
 #define FC_VPORT_NUM_ATTRS	9
 #define FC_HOST_NUM_ATTRS	29
@@ -358,10 +361,12 @@ static int fc_target_setup(struct transport_container *tc, struct device *dev,
 		fc_starget_node_name(starget) = rport->node_name;
 		fc_starget_port_name(starget) = rport->port_name;
 		fc_starget_port_id(starget) = rport->port_id;
+		fc_starget_port_state(starget) = rport->port_state;
 	} else {
 		fc_starget_node_name(starget) = -1;
 		fc_starget_port_name(starget) = -1;
 		fc_starget_port_id(starget) = -1;
+		fc_starget_port_state(starget) = FC_PORTSTATE_UNKNOWN;
 	}
 
 	return 0;
@@ -995,6 +1000,93 @@ static FC_DEVICE_ATTR(rport, fast_io_fail_tmo, S_IRUGO | S_IWUSR,
 /*
  * FC SCSI Target Attribute Management
  */
+static void scsi_target_chg_noretries_abort(struct scsi_target *starget, int set)
+{
+	struct scsi_device *sdev, *tmp;
+	struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
+	unsigned long flags;
+
+	spin_lock_irqsave(shost->host_lock, flags);
+	list_for_each_entry_safe(sdev, tmp, &starget->devices, same_target_siblings) {
+		if (sdev->sdev_state == SDEV_DEL)
+			continue;
+
+		spin_unlock_irqrestore(shost->host_lock, flags);
+		if (scsi_device_get(sdev))
+			continue;
+
+		spin_unlock_irqrestore(shost->host_lock, flags);
+		scsi_chg_noretries_abort_io_device(sdev, set);
+		spin_lock_irqsave(shost->host_lock, flags);
+		scsi_device_put(sdev);
+	}
+	spin_unlock_irqrestore(shost->host_lock, flags);
+}
+
+/*
+ * Sets port_state to Marginal/Online.
+ * On Marginal it Sets  no retries on abort in scmd->state for all
+ * outstanding io of all the scsi_devs
+ * This only allows ONLINE->MARGINAL and MARGINAL->ONLINE
+ */
+static ssize_t fc_target_set_marginal_state(struct device *dev,
+						struct device_attribute *attr,
+						const char *buf, size_t count)
+{
+	struct scsi_target *starget = transport_class_to_starget(dev);
+	struct fc_rport *rport = starget_to_rport(starget);
+	enum fc_port_state port_state;
+	int ret = 0;
+
+	ret = get_fc_port_state_match(buf, &port_state);
+
+	if (port_state == FC_PORTSTATE_MARGINAL) {
+
+		/*
+		 * Change the state to marginal only if the
+		 * current rport state is Online
+		 * Allow only Online->marginal
+		 */
+		if (rport->port_state == FC_PORTSTATE_ONLINE) {
+			rport->port_state = port_state;
+			scsi_target_chg_noretries_abort(starget, 1);
+		}
+
+	} else if (port_state == FC_PORTSTATE_ONLINE) {
+		/*
+		 * Change the state to Online only if the
+		 * current rport state is Marginal
+		 * Allow only  MArginal->Online
+		 */
+
+		if (rport->port_state == FC_PORTSTATE_MARGINAL) {
+			rport->port_state = port_state;
+			scsi_target_chg_noretries_abort(starget, 0);
+		}
+
+
+	} else
+		return -EINVAL;
+	return count;
+}
+
+static ssize_t
+fc_target_show_port_state(struct device *dev,
+				struct device_attribute *attr, char *buf)
+{
+	const char *name;
+	struct scsi_target *starget = transport_class_to_starget(dev);
+	struct fc_rport *rport = starget_to_rport(starget);
+
+	name = get_fc_port_state_name(rport->port_state);
+	if (!name)
+		return -EINVAL;
+
+	return snprintf(buf, 20, "%s\n", name);
+}
+
+static FC_DEVICE_ATTR(starget, port_state, 0444 | 0200,
+		fc_target_show_port_state, fc_target_set_marginal_state);
 
 /*
  * Note: in the target show function we recognize when the remote
@@ -1037,6 +1129,13 @@ static FC_DEVICE_ATTR(starget, field, S_IRUGO,			\
 	if (i->f->show_starget_##field)					\
 		count++
 
+#define SETUP_PRIVATE_STARGET_ATTRIBUTE_RW(field)			\
+do {									\
+	i->private_starget_attrs[count] = device_attr_starget_##field; \
+	i->starget_attrs[count] = &i->private_starget_attrs[count];	\
+	count++;							\
+} while (0)
+
 #define SETUP_STARGET_ATTRIBUTE_RW(field)				\
 	i->private_starget_attrs[count] = device_attr_starget_##field; \
 	if (!i->f->set_starget_##field) {				\
@@ -2095,7 +2194,8 @@ fc_user_scan_tgt(struct Scsi_Host *shost, uint channel, uint id, u64 lun)
 		if (rport->scsi_target_id == -1)
 			continue;
 
-		if (rport->port_state != FC_PORTSTATE_ONLINE)
+		if ((rport->port_state != FC_PORTSTATE_ONLINE) &&
+			(rport->port_state != FC_PORTSTATE_MARGINAL))
 			continue;
 
 		if ((channel == rport->channel) &&
@@ -2198,7 +2298,7 @@ fc_attach_transport(struct fc_function_template *ft)
 	SETUP_STARGET_ATTRIBUTE_RD(node_name);
 	SETUP_STARGET_ATTRIBUTE_RD(port_name);
 	SETUP_STARGET_ATTRIBUTE_RD(port_id);
-
+	SETUP_PRIVATE_STARGET_ATTRIBUTE_RW(port_state);
 	BUG_ON(count > FC_STARGET_NUM_ATTRS);
 
 	i->starget_attrs[count] = NULL;
@@ -2958,7 +3058,8 @@ fc_remote_port_delete(struct fc_rport  *rport)
 
 	spin_lock_irqsave(shost->host_lock, flags);
 
-	if (rport->port_state != FC_PORTSTATE_ONLINE) {
+	if ((rport->port_state != FC_PORTSTATE_ONLINE) &&
+		(rport->port_state != FC_PORTSTATE_MARGINAL)) {
 		spin_unlock_irqrestore(shost->host_lock, flags);
 		return;
 	}
@@ -3100,7 +3201,8 @@ fc_timeout_deleted_rport(struct work_struct *work)
 	 * target, validate it still is. If not, tear down the
 	 * scsi_target on it.
 	 */
-	if ((rport->port_state == FC_PORTSTATE_ONLINE) &&
+	if (((rport->port_state == FC_PORTSTATE_ONLINE) ||
+		(rport->port_state == FC_PORTSTATE_MARGINAL)) &&
 	    (rport->scsi_target_id != -1) &&
 	    !(rport->roles & FC_PORT_ROLE_FCP_TARGET)) {
 		dev_printk(KERN_ERR, &rport->dev,
@@ -3243,7 +3345,8 @@ fc_scsi_scan_rport(struct work_struct *work)
 	struct fc_internal *i = to_fc_internal(shost->transportt);
 	unsigned long flags;
 
-	if ((rport->port_state == FC_PORTSTATE_ONLINE) &&
+	if (((rport->port_state == FC_PORTSTATE_ONLINE) ||
+		(rport->port_state == FC_PORTSTATE_ONLINE)) &&
 	    (rport->roles & FC_PORT_ROLE_FCP_TARGET) &&
 	    !(i->f->disable_target_scan)) {
 		scsi_scan_target(&rport->dev, rport->channel,
@@ -3747,7 +3850,8 @@ static blk_status_t fc_bsg_rport_prep(struct fc_rport *rport)
 	    !(rport->flags & FC_RPORT_FAST_FAIL_TIMEDOUT))
 		return BLK_STS_RESOURCE;
 
-	if (rport->port_state != FC_PORTSTATE_ONLINE)
+	if ((rport->port_state != FC_PORTSTATE_ONLINE) &&
+		(rport->port_state != FC_PORTSTATE_MARGINAL))
 		return BLK_STS_IOERR;
 
 	return BLK_STS_OK;
-- 
2.26.2


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