[SCSI] Better log messages for PQ3 devs

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 patch 2/3:
If a PQ3 device is found, log a message that describes the device
(INQUIRY DATA and C:B:T:U tuple) and make a suggestion for blacklisting
it.

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

1 files changed, 35 insertions, 3 deletions

diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 820c4ad7b581..5603dc6eca47 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -808,6 +808,29 @@ static inline void scsi_destroy_sdev(struct scsi_device *sdev)
         put_device(&sdev->sdev_gendev);
 }
 
+/** 
+ * scsi_inq_str - print INQUIRY data from min to max index,
+ * strip trailing whitespace
+ * @buf:   Output buffer with at least end-first+1 bytes of space
+ * @inq:   Inquiry buffer (input)
+ * @first: Offset of string into inq
+ * @end:   Index after last character in inq
+ */
+static unsigned char* scsi_inq_str(unsigned char* buf, unsigned char *inq,
+                                   unsigned first, unsigned end)
+{
+        unsigned term = 0, idx;
+        for (idx = 0; idx+first < end && idx+first < inq[4]+5; ++idx) {
+                if (inq[idx+first] > 0x20) {
+                        buf[idx] = inq[idx+first];
+                        term = idx+1;
+                } else {
+                        buf[idx] = ' ';
+                }
+        }
+        buf[term] = 0;
+        return buf;
+}
 
 /**
  * scsi_probe_and_add_lun - probe a LUN, if a LUN is found add it
@@ -888,9 +911,18 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget,
                  * logical disk configured at sdev->lun, but there
                  * is a target id responding.
                  */
-                SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO
-                                        "scsi scan: peripheral qualifier of 3,"
-                                        " no device added\n"));
+                SCSI_LOG_SCAN_BUS(2, sdev_printk(KERN_INFO, sdev, "scsi scan:"
+                                   " peripheral qualifier of 3, device not"
+                                   " added\n"))
+                if (lun == 0) {
+                        unsigned char vend[9], mod[17];
+                        SCSI_LOG_SCAN_BUS(1, sdev_printk(KERN_INFO, sdev,
+                                        "scsi scan: consider passing scsi_mod."
+                                        "dev_flags=%s:%s:0x240 or 0x800240\n",
+                                        scsi_inq_str(vend, result, 8, 16),
+                                        scsi_inq_str(mod, result, 16, 32)));
+                }
+                
                 res = SCSI_SCAN_TARGET_PRESENT;
                 goto out_free_result;
         }