Re: [PATCH 1/1] scsi_dh: add ALUA notification for EMC Clariion devices

[Matthew Wilcox <matthew@wil.cx>]

On Tue, Sep 23, 2008 at 10:46:18AM -0400, Levy_Jerome@emc.com wrote:
> Adding sense code data decode and notification for optimal/non-optimal
> path changeover on Clariion devices. Unfortunately in the read sense
> code we can't do another inquiry, so we can't tell the user whether we
> are on the optimal or non-optimal path, only that a change has occurred.

I'm not sure that printk is the optimal user notification here.

What if we had a uevent so that udev could take action, such as issuing
an inquiry?

What if we scheduled some work so we could issue an inquiry and take
appropriate action?

>         case UNIT_ATTENTION:
> +                if (sense_hdr->asc == 0x2A && sense_hdr->ascq == 0x06)
> +                        /*
> +                         * ALUA status has changed. Report to host,
> +                         * no further action required... jml
> +                         */
> +                        sdev_printk(KERN_NOTICE, sdev,
> +                                    "%s: Asymmetric access state has
> changed.\n",
> +                                    CLARIION_NAME);
> +                        return SUCCESS;
> +                break;
>                 if (sense_hdr->asc == 0x29 && sense_hdr->ascq == 0x00)

-- 
Matthew Wilcox				Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours.  We can't possibly take such
a retrograde step."