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 <tonyb@cybernetics.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent f28cd7cf

drivers/scsi/scsi_lib.c

+2 −2
Original line number Diff line number Diff line
@@ -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;

drivers/scsi/scsi_scan.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

include/scsi/scsi_device.h

+3 −3
Original line number Diff line number Diff line
@@ -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 */

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