Commit 25d7c363 authored by Tony Battersby's avatar Tony Battersby Committed by James Bottomley
Browse files

[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: default avatarTony Battersby <>
Signed-off-by: default avatarJames Bottomley <>
parent f28cd7cf
......@@ -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)
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;
......@@ -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;
......@@ -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
* 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 */
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