n Wed, 2012-07-18 at 18:49 +0200, olaf@xxxxxxxxx wrote: > From: Linda Xie <lxiep@xxxxxxxxxx> > > Expected result: > It should show something like this: > x1521p4:~ # cat /sys/class/scsi_host/host1/config > PARTITIONNAME='x1521p4' > NWSDNAME='X1521P4' > HOSTNAME='X1521P4' > DOMAINNAME='RCHLAND.IBM.COM' > NAMESERVERS='9.10.244.100 9.10.244.200' > > Actual result: > x1521p4:~ # cat /sys/class/scsi_host/host0/config > x1521p4:~ # > > This patch changes the size of the buffer used for transfering config > data to 4K. It was tested against 2.6.19-rc2 tree. > > Reported by IBM during SLES11 beta testing: So this patch just seems to blindly replace all occurrences of PAGE_SIZE with HOST_PAGE_SIZE which is utterly wrong. Only one of those needs to be changed, the one passed to ibmvscsi_do_host_config() which is what's visible to the server, all the rest is just sysfs attributes and should remain as-is. Additionally (not even mentioning that there is no explanation as to what the real problem is anywhere in the changeset) I don't like the fix. The root of the problem is that the MAD header has a 16-bit length field, so writing 0x10000 (64K PAGE_SIZE) into it doesn't quite work. So in addition to a better comment, I would suggest a fix more like this: scsi/ibmvscsi: Fix host config length field overflow The length field in the host config packet is only 16-bit long, so passing it 0x10000 (64K which is our standard PAGE_SIZE) doesn't work and result in an empty config from the server. Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx> CC: <stable@xxxxxxxxxxxxxxx> --- diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c index 3a6c474..337e8b3 100644 --- a/drivers/scsi/ibmvscsi/ibmvscsi.c +++ b/drivers/scsi/ibmvscsi/ibmvscsi.c @@ -1541,6 +1541,9 @@ static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata, host_config = &evt_struct->iu.mad.host_config; + /* The transport length field is only 16-bit */ + length = min(0xffff, length); + /* Set up a lun reset SRP command */ memset(host_config, 0x00, sizeof(*host_config)); host_config->common.type = VIOSRP_HOST_CONFIG_TYPE; -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
