[SCSI] Try LUN 1 and use bflags

Some devices report a peripheral qualifier of 3 for LUN 0; with the original
code, we would still try a REPORT_LUNS scan (if SCSI level is >= 3 or if we
have the BLIST_REPORTLUNS2 passed in), but NOT any sequential scan.
Also, the device at LUN 0 (which is not connected according to the PQ) is not
registered with the OS.

Unfortunately, SANs exist that are SCSI-2 and do NOT support REPORT_LUNS, but
report a unknown device with PQ 3 on LUN 0. We still need to scan them, and
most probably we even need BLIST_SPARSELUN (and BLIST_LARGELUN). See the bug
reference for an infamous example.

This is patch 1/3:
If we end up in sequential scan, at least try LUN 1 for devices
that reported a PQ of 3 for LUN 0.
Also return blacklist flags, even for PQ3 devices.

Signed-off-by: Kurt Garloff <garloff@suse.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

1 files changed, 4 insertions, 13 deletions

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index f14945996ede..820c4ad7b581 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -872,6 +872,8 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
         if (scsi_probe_lun(sdev, result, result_len, &bflags))
                 goto out_free_result;
 
+        if (bflagsp)
+                *bflagsp = bflags;
         /*
          * result contains valid SCSI INQUIRY data.
          */
@@ -912,8 +914,6 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
                         sdev->lockable = 0;
                         scsi_unlock_floptical(sdev, result);
                 }
-                if (bflagsp)
-                        *bflagsp = bflags;
         }
 
  out_free_result:
@@ -938,7 +938,6 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
  * scsi_sequential_lun_scan - sequentially scan a SCSI target
  * @starget:    pointer to target structure to scan
  * @bflags:     black/white list flag for LUN 0
- * @lun0_res:   result of scanning LUN 0
  *
  * Description:
  *     Generally, scan from LUN 1 (LUN 0 is assumed to already have been
@@ -948,8 +947,7 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
  *     Modifies sdevscan->lun.
  **/
 static void scsi_sequential_lun_scan(struct scsi_target *starget,
-                                     int bflags, int lun0_res, int scsi_level,
-                                     int rescan)
+                                     int bflags, int scsi_level, int rescan)
 {
         unsigned int sparse_lun, lun, max_dev_lun;
         struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
@@ -970,13 +968,6 @@ static void scsi_sequential_lun_scan(struct scsi_target *starget,
                 sparse_lun = 0;
 
         /*
-         * If not sparse lun and no device attached at LUN 0 do not scan
-         * any further.
-         */
-        if (!sparse_lun && (lun0_res != SCSI_SCAN_LUN_PRESENT))
-                return;
-
-        /*
          * If less than SCSI_1_CSS, and no special lun scaning, stop
          * scanning; this matches 2.4 behaviour, but could just be a bug
          * (to continue scanning a SCSI_1_CSS device).
@@ -1384,7 +1375,7 @@ static void __scsi_scan_target(struct device *parent, unsigned int channel,
                          * do a sequential scan.
                          */
                         scsi_sequential_lun_scan(starget, bflags,
-                                        res, starget->scsi_level, rescan);
+                                                 starget->scsi_level, rescan);
         }
 
  out_reap: