[SCSI] fix check of PQ and PDT bits for WLUNs

For IBM z series certain LUNs can no longer be accessed.

This is because kernel version 2.6.19 a check was introduced not to
create a generic SCSI device for devices that return PQ=1 and
PDT=0x1f. For WLUNs (see SAM-3, p. 41ff) generic SCSI devices should
be created unconditionally without looking at the PQ bit, so add a
check for WLUNs in with this test.

Acked-by: Martin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 84b4879cff11..34d0de6cd511 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1080,7 +1080,8 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
          * PDT=1Fh none (no FDD connected to the requested logical unit)
          */
         if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&
-             (result[0] & 0x1f) == 0x1f) {
+            (result[0] & 0x1f) == 0x1f &&
+            !scsi_is_wlun(lun)) {
                 SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
                                         "scsi scan: peripheral device type"
                                         " of 31, no device added\n"));