[SCSI] move single_lun flag from scsi_device to scsi_target

Some SCSI tape medium changers that need the BLIST_SINGLELUN flag have
the medium changer at one LUN and the tape drive at a different LUN.
The inquiry string of the tape drive may be different from that of the
medium changer.  In order for single_lun to be effective, every
scsi_device under a given scsi_target must have it set.  This means that
there needs to be a blacklist entry for BOTH the medium changer AND the
tape drive, which is impractical because some medium changers may be
paired with a variety of different tape drive models.  It makes more
sense to put the single_lun flag in scsi_target instead of scsi_device,
which causes every device at a given target ID to inherit the single_lun
flag from one LUN.  This makes it possible to blacklist just the medium
changer and not the tape drive.

Signed-off-by: Tony Battersby <tonyb@cybernetics.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

3 files changed, 6 insertions, 6 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 199b02452259..b0c59ae63a2f 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -526,7 +526,7 @@ static void scsi_run_queue(struct request_queue *q)
         struct Scsi_Host *shost = sdev->host;
         unsigned long flags;
 
-        if (sdev->single_lun)
+        if (scsi_target(sdev)->single_lun)
                 scsi_single_lun_run(sdev);
 
         spin_lock_irqsave(shost->host_lock, flags);
@@ -1559,7 +1559,7 @@ static void scsi_request_fn(struct request_queue *q)
 
                 if (!scsi_host_queue_ready(q, shost, sdev))
                         goto not_ready;
-                if (sdev->single_lun) {
+                if (scsi_target(sdev)->single_lun) {
                         if (scsi_target(sdev)->starget_sdev_user &&
                             scsi_target(sdev)->starget_sdev_user != sdev)
                                 goto not_ready;
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 7e8b2045ccfa..ada72af0a6dd 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -865,7 +865,7 @@ static int scsi_add_lun(struct scsi_device *sdev, unsigned char *inq_result,
                 sdev->no_start_on_add = 1;
 
         if (*bflags & BLIST_SINGLELUN)
-                sdev->single_lun = 1;
+                scsi_target(sdev)->single_lun = 1;
 
         sdev->use_10_for_rw = 1;
 
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 6c2d80b36aa1..45bb12b54175 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -122,9 +122,6 @@ struct scsi_device {
         unsigned tagged_supported:1;    /* Supports SCSI-II tagged queuing */
         unsigned simple_tags:1; /* simple queue tag messages are enabled */
         unsigned ordered_tags:1;/* ordered queue tag messages are enabled */
-        unsigned single_lun:1;  /* Indicates we should only allow I/O to
-                                 * one of the luns for the device at a 
-                                 * time. */
         unsigned was_reset:1;   /* There was a bus reset on the bus for 
                                  * this device */
         unsigned expecting_cc_ua:1; /* Expecting a CHECK_CONDITION/UNIT_ATTN
@@ -202,6 +199,9 @@ struct scsi_target {
         unsigned int            id; /* target id ... replace
                                      * scsi_device.id eventually */
         unsigned int            create:1; /* signal that it needs to be added */
+        unsigned int            single_lun:1;   /* Indicates we should only
+                                                 * allow I/O to one of the luns
+                                                 * for the device at a time. */
         unsigned int            pdt_1f_for_no_lun;      /* PDT = 0x1f */
                                                 /* means no lun present */