[SCSI] Log msg when getting Unit Attention

If the user accidentally changes LUN mappings or it occurs
due to a bug, then it can cause data corruption that can take
months and months to track down. This patch adds a log
message when getting REPORT_LUNS_DATA_CHANGED and it adds
a generic message for other Unit Attentions with asc == 0x3f.

We are working on adding support for handling of these errors,
but I think until then we should at least log a message so
tracking down problems as a result of one of these changes
is a little easier.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

diff --git a/drivers/scsi/scsi_error.c b/drivers/scsi/scsi_error.c
index a5d630f..c60cffb 100644 (file)
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -307,6 +307,19 @@ static int scsi_check_sense(struct scsi_cmnd *scmd)
                    (sshdr.asc == 0x04) && (sshdr.ascq == 0x02))
                        return FAILED;
 
+               if (sshdr.asc == 0x3f && sshdr.ascq == 0x0e)
+                       scmd_printk(KERN_WARNING, scmd,
+                                   "Warning! Received an indication that the "
+                                   "LUN assignments on this target have "
+                                   "changed. The Linux SCSI layer does not "
+                                   "automatically remap LUN assignments.\n");
+               else if (sshdr.asc == 0x3f)
+                       scmd_printk(KERN_WARNING, scmd,
+                                   "Warning! Received an indication that the "
+                                   "operating parameters on this target have "
+                                   "changed. The Linux SCSI layer does not "
+                                   "automatically adjust these parameters.\n");
+
                if (blk_barrier_rq(scmd->request))
                        /*
                         * barrier requests should always retry on UA