[dm-devel] rdac.c patch not quite right.

[Chaskiel Grundman <cg2v andrew cmu edu>]

commit 362d2e5f215894818b52a0d03b723b75917390fb
added the following block to rdac.c:

        } else if ((inq.PQ_PDT & 0x20) || (inq.PQ_PDT & 0x7f)) {
                /* LUN not connected*/
                ret = PATH_DOWN;
                goto done;
        }

I don't know what the intended effect actually was, but since
(inq.PQ_PDT & 0x20) will be true if (inq.PQ_PDT & 0x7f), the code is
incorrect as-is. I have some dell RDAC devices, but I cannot delete
targets on any of them to test this.

Update, after reading some scsi docs: If RDAC is using the standard
peripheral qualifier semantics, I think the following is what should be
used instead


        } else if ((inq.PQ_PDT & 0xE0) == 0x20 || inq.PQ_PDT == 0x7f) {

This form checks for the PQ bits being 001 or 011, and if 011, also
that the device type has the standard value for an unsupported
lun.

Alternatively,

        } else if ((inq.PQ_PDT & 0xC0) == 0x20) {

does not validate the device type bits in case the PQ is 011