[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>

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 199b024..b0c59ae 100644 (file)
--- 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 7e8b204..ada72af 100644 (file)
--- 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 6c2d80b..45bb12b 100644 (file)
--- 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 */