Re: [PATCH RFC 1/2] add transport scan callout to fix sysfs layout when scanning from userspace

[Patrick Mansfield <patmans@us.ibm.com>]

On Tue, May 24, 2005 at 04:01:43PM -0700, Patrick Mansfield wrote:

> I was trying FC to see if it caused problems, instead of a different
> layout, no devices are found at all :-(

The qla2xxx_slave_alloc() is returning -ENXIO, and we don't output any
printks in that case for qla2xxx. I added a couple qla_printk's and got
lots of:

	qla2300 0000:01:0c.0: no rport for <7:0:0:0>

For:

	echo "- - -"  > /sys/class/scsi_host/hostX/scan

A change similar change what Mike C. did for iSCSI is needed for FC
transport, or any transport that has a "device" between the host and
target. For qla, we need to eventually call its slave_alloc() with a
target under an rport (so starget_to_rport() gets the rport).

Having a transportt->scan seems a bit high level, I have no better
suggestion, there should be a way to make this generic for all transports.

It is easy for iSCSI since it has a one-to-one mapping of scsi_host to
scsi_target: AFAICT you just call scsi_scan_target() once. FC has to
iterate over all rports, and call scsi_scan_target() for all targets, or
find the rport that matches the id.

Where is iscsi_register_transport? A current git tree? I should probably
be using that tree, still trying to get up to speed on git.

qla2xxx debug patch, but we should always print something when 
returning -ENXIO:

--- linux-2.6.12-rc4/drivers/scsi/qla2xxx/orig-qla_os.c	Fri May  6 22:20:31 2005
+++ linux-2.6.12-rc4/drivers/scsi/qla2xxx/qla_os.c	Tue May 24 16:58:14 2005
@@ -992,8 +992,12 @@ qla2xxx_slave_alloc(struct scsi_device *
 	fc_port_t *fcport;
 	int found;
 
-	if (!rport)
+	if (!rport) {
+		qla_printk(KERN_WARNING, ha,
+		    "no rport for <%d:%d:%d:%d>\n",
+		    sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
 		return -ENXIO;
+	}
 
 	found = 0;
 	list_for_each_entry(fcport, &ha->fcports, list) {
@@ -1003,8 +1007,12 @@ qla2xxx_slave_alloc(struct scsi_device *
 			break;
 		}
 	}
-	if (!found)
+	if (!found) {
+		qla_printk(KERN_WARNING, ha,
+		    "no device at <%d:%d:%d:%d>\n",
+		    sdev->host->host_no, sdev->channel, sdev->id, sdev->lun);
 		return -ENXIO;
+	}
 
 	sdev->hostdata = fcport;