[PATCH 5/5] scsi_transport_fc: Added a new sysfs attribute noretries_abort

[Muneendra <muneendra.kumar@xxxxxxxxxxxx>]

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

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.

Below is the interface provided to abort the io
echo 1 >> /sys/class/fc_transport/targetX\:Y\:Z/noretries_abort

Signed-off-by: Muneendra <muneendra.kumar@xxxxxxxxxxxx>
---
 drivers/scsi/scsi_transport_fc.c | 49 ++++++++++++++++++++++++++++++++++++++--
 1 file changed, 47 insertions(+), 2 deletions(-)

diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c
index 2732fa6..f7b00ae 100644
--- a/drivers/scsi/scsi_transport_fc.c
+++ b/drivers/scsi/scsi_transport_fc.c
@@ -305,7 +305,7 @@ struct device_attribute device_attr_##_prefix##_##_name = 	\
  * 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
@@ -994,6 +994,44 @@ static FC_DEVICE_ATTR(rport, fast_io_fail_tmo, S_IRUGO | S_IWUSR,
 /*
  * FC SCSI Target Attribute Management
  */
+static void scsi_target_set_noretries_abort(struct scsi_target *starget)
+{
+	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;
+		if (scsi_device_get(sdev))
+			continue;
+
+		spin_unlock_irqrestore(shost->host_lock, flags);
+		scsi_set_noretries_abort_io_device(sdev);
+		spin_lock_irqsave(shost->host_lock, flags);
+		scsi_device_put(sdev);
+	}
+	spin_unlock_irqrestore(shost->host_lock, flags);
+}
+
+/*
+ * Sets  no retries on abort in scmd->state for all
+ * outstanding io of all the scsi_devs
+ * write 1 to set the bit for all outstanding io's
+ */
+static ssize_t fc_target_set_noretries_abort(struct device *dev,
+						struct device_attribute *attr,
+						const char *buf, size_t count)
+{
+	struct scsi_target *starget = transport_class_to_starget(dev);
+
+	scsi_target_set_noretries_abort(starget);
+	return count;
+}
+
+static FC_DEVICE_ATTR(starget, noretries_abort, 0200,
+		NULL, fc_target_set_noretries_abort);
 
 /*
  * Note: in the target show function we recognize when the remote
@@ -1036,6 +1074,13 @@ 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) {				\
@@ -2197,7 +2242,7 @@ struct scsi_transport_template *
 	SETUP_STARGET_ATTRIBUTE_RD(node_name);
 	SETUP_STARGET_ATTRIBUTE_RD(port_name);
 	SETUP_STARGET_ATTRIBUTE_RD(port_id);
-
+	SETUP_PRIVATE_STARGET_ATTRIBUTE_RW(noretries_abort);
 	BUG_ON(count > FC_STARGET_NUM_ATTRS);
 
 	i->starget_attrs[count] = NULL;
-- 
1.8.3.1