[PATCH 2/5] allow activation of eh on DID_NO_CONNECT

[Bernd Schubert <bs@q-leap.de>]

Introduce a sysfs attribute to allow to activate the error handler for
these devices in case of DID_NO_CONNECT. This is useful for our parallel
scsi devices.

Signed-off-by: Bernd Schubert: <bs@q-leap.de>

---
 drivers/scsi/scsi_error.c  |    2 ++
 drivers/scsi/scsi_sysfs.c  |   28 ++++++++++++++++++++++++++++
 include/scsi/scsi_device.h |    1 +
 3 files changed, 31 insertions(+)

Index: linux-2.6/include/scsi/scsi_device.h
===================================================================
--- linux-2.6.orig/include/scsi/scsi_device.h
+++ linux-2.6/include/scsi/scsi_device.h
@@ -145,6 +145,7 @@ struct scsi_device {
 	unsigned retry_hwerror:1;	/* Retry HARDWARE_ERROR */
 	unsigned last_sector_bug:1;	/* do not use multisector accesses on
 					   SD_LAST_BUGGY_SECTORS */
+	unsigned eh_did_no_connect:1;	/* eh on DID_NO_CONNECT */
 
 	DECLARE_BITMAP(supported_events, SDEV_EVT_MAXBITS); /* supported events */
 	struct list_head event_list;	/* asserted events */
Index: linux-2.6/drivers/scsi/scsi_error.c
===================================================================
--- linux-2.6.orig/drivers/scsi/scsi_error.c
+++ linux-2.6/drivers/scsi/scsi_error.c
@@ -1359,6 +1359,8 @@ int scsi_decide_disposition(struct scsi_
 		 */
 		break;
 	case DID_NO_CONNECT:
+		if (scmd->device->eh_did_no_connect)
+			return FAILED;
 	case DID_BAD_TARGET:
 	case DID_ABORT:
 		/*
Index: linux-2.6/drivers/scsi/scsi_sysfs.c
===================================================================
--- linux-2.6.orig/drivers/scsi/scsi_sysfs.c
+++ linux-2.6/drivers/scsi/scsi_sysfs.c
@@ -565,6 +565,33 @@ sdev_rd_attr (rev, "%.4s\n");
  * TODO: can we make these symlinks to the block layer ones?
  */
 static ssize_t
+sdev_show_eh_dnc(struct device *dev, struct device_attribute *attr, char 
*buf)
+{
+	struct scsi_device *sdev;
+	sdev = to_scsi_device(dev);
+	return snprintf(buf, 20, "%d\n", sdev->eh_did_no_connect);
+}
+
+static ssize_t
+sdev_store_eh_dnc(struct device *dev, struct device_attribute *attr,
+		  const char *buf, size_t count)
+{
+	struct scsi_device *sdev;
+	int eh_dnc;
+	sdev = to_scsi_device(dev);
+	sscanf(buf, "%d\n", &eh_dnc);
+
+	if (eh_dnc != 0 && eh_dnc != 1)
+		return -EINVAL;
+
+	sdev->eh_did_no_connect = eh_dnc;
+	return count;
+}
+static DEVICE_ATTR(eh_did_no_connect, S_IRUGO | S_IWUSR,
+		   sdev_show_eh_dnc, sdev_store_eh_dnc);
+
+
+static ssize_t
 sdev_show_timeout (struct device *dev, struct device_attribute *attr, char 
*buf)
 {
 	struct scsi_device *sdev;
@@ -755,6 +782,7 @@ static struct attribute *scsi_sdev_attrs
 	&dev_attr_ioerr_cnt.attr,
 	&dev_attr_modalias.attr,
 	REF_EVT(media_change),
+	&dev_attr_eh_did_no_connect,
 	NULL
 };