[PATCH] zfcp: Report FCP LUN to SCSI midlayer

[PATCH] zfcp: Report FCP LUN to SCSI midlayer

[Swen Schillig]

From: Christof Schmitt <christof.schmitt@de.ibm.com>

When reporting SCSI devices to the SCSI midlayer, use the FCP LUN as
LUN reported to the SCSI layer. With this approach, zfcp does not have
to create unique LUNS, and this code can be removed.

Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
Signed-off-by: Swen Schillig <swen@vnet.ibm.com>

---

 drivers/s390/scsi/zfcp_aux.c |   22 ++++------------------
 drivers/scsi/scsi_scan.c     |    3 ++-
 include/scsi/scsi_device.h   |    1 +
 3 files changed, 7 insertions(+), 19 deletions(-)

diff --git a/drivers/s390/scsi/zfcp_aux.c b/drivers/s390/scsi/zfcp_aux.c
index 821cde6..c631cf7 100644
--- a/drivers/s390/scsi/zfcp_aux.c
+++ b/drivers/s390/scsi/zfcp_aux.c
@@ -815,9 +815,7 @@ zfcp_get_adapter_by_busid(char *bus_id)
 struct zfcp_unit *
 zfcp_unit_enqueue(struct zfcp_port *port, fcp_lun_t fcp_lun)
 {
-	struct zfcp_unit *unit, *tmp_unit;
-	unsigned int scsi_lun;
-	int found;
+	struct zfcp_unit *unit;

 	/*
 	 * check that there is no unit with this FCP_LUN already in list
@@ -863,22 +861,10 @@ zfcp_unit_enqueue(struct zfcp_port *port, fcp_lun_t fcp_lun)
 	}

 	zfcp_unit_get(unit);
-
-	scsi_lun = 0;
-	found = 0;
+	unit->scsi_lun = scsilun_to_int((struct scsi_lun *)&unit->fcp_lun);
+	
 	write_lock_irq(&zfcp_data.config_lock);
-	list_for_each_entry(tmp_unit, &port->unit_list_head, list) {
-		if (tmp_unit->scsi_lun != scsi_lun) {
-			found = 1;
-			break;
-		}
-		scsi_lun++;
-	}
-	unit->scsi_lun = scsi_lun;
-	if (found)
-		list_add_tail(&unit->list, &tmp_unit->list);
-	else
-		list_add_tail(&unit->list, &port->unit_list_head);
+	list_add_tail(&unit->list, &port->unit_list_head);
 	atomic_clear_mask(ZFCP_STATUS_COMMON_REMOVE, &unit->status);
 	atomic_set_mask(ZFCP_STATUS_COMMON_RUNNING, &unit->status);
 	write_unlock_irq(&zfcp_data.config_lock);
diff --git a/drivers/scsi/scsi_scan.c b/drivers/scsi/scsi_scan.c
index 662577f..cf95ad9 100644
--- a/drivers/scsi/scsi_scan.c
+++ b/drivers/scsi/scsi_scan.c
@@ -1213,7 +1213,7 @@ static void scsi_sequential_lun_scan(struct scsi_target *starget,
  *     Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
  *     the integer: 0x0b030a04
  **/
-static int scsilun_to_int(struct scsi_lun *scsilun)
+int scsilun_to_int(struct scsi_lun *scsilun)
 {
 	int i;
 	unsigned int lun;
@@ -1224,6 +1224,7 @@ static int scsilun_to_int(struct scsi_lun *scsilun)
 			      scsilun->scsi_lun[i + 1]) << (i * 8));
 	return lun;
 }
+EXPORT_SYMBOL(scsilun_to_int);

 /**
  * int_to_scsilun: reverts an int into a scsi_lun
diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
index 2f3c5b8..6fe1cf6 100644
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -287,6 +287,7 @@ extern void scsi_target_block(struct device *);
 extern void scsi_target_unblock(struct device *);
 extern void scsi_remove_target(struct device *);
 extern void int_to_scsilun(unsigned int, struct scsi_lun *);
+extern int scsilun_to_int(struct scsi_lun *);
 extern const char *scsi_device_state_name(enum scsi_device_state);
 extern int scsi_is_sdev_device(const struct device *);
 extern int scsi_is_target_device(const struct device *);

Re: [PATCH] zfcp: Report FCP LUN to SCSI midlayer

[Hannes Reinecke]

Swen Schillig wrote:
> From: Christof Schmitt <christof.schmitt@de.ibm.com>
> 
> When reporting SCSI devices to the SCSI midlayer, use the FCP LUN as
> LUN reported to the SCSI layer. With this approach, zfcp does not have
> to create unique LUNS, and this code can be removed.
> 
> Signed-off-by: Christof Schmitt <christof.schmitt@de.ibm.com>
> Signed-off-by: Swen Schillig <swen@vnet.ibm.com>
> 
Grand. Another zfcp-ism removed.

FWIW:

Signed-off-by: Hannes Reinecke <hare@suse.de>

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@suse.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Markus Rex, HRB 16746 (AG Nürnberg)
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Re: [PATCH] zfcp: Report FCP LUN to SCSI midlayer

[Stefan Richter]

Swen Schillig wrote:
> --- a/drivers/scsi/scsi_scan.c
> +++ b/drivers/scsi/scsi_scan.c
> @@ -1213,7 +1213,7 @@ static void scsi_sequential_lun_scan(struct scsi_target *starget,
>   *     Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns
>   *     the integer: 0x0b030a04
>   **/
> -static int scsilun_to_int(struct scsi_lun *scsilun)
> +int scsilun_to_int(struct scsi_lun *scsilun)
>  {
>  	int i;
>  	unsigned int lun;
> @@ -1224,6 +1224,7 @@ static int scsilun_to_int(struct scsi_lun *scsilun)
>  			      scsilun->scsi_lun[i + 1]) << (i * 8));
>  	return lun;
>  }
> +EXPORT_SYMBOL(scsilun_to_int);

This export will be useful for fw-sbp2 too.
-- 
Stefan Richter
-=====-=-=== -==- =--==
http://arcgraph.de/sr/

Re: [PATCH] zfcp: Report FCP LUN to SCSI midlayer

[Christoph Hellwig]

On Tue, Jun 19, 2007 at 10:25:30AM +0200, Swen Schillig wrote:
> +	unit->scsi_lun = scsilun_to_int((struct scsi_lun *)&unit->fcp_lun);
> +	

fcp_lun is an unsigned long long (and should be a __be64), so casting
this to a struct type is not very nice.  Care to add a version that takes
a __be64 intead?  In fact using that variant in scsi_scan.c might be
benefical aswell, so you could aswell just convert over the existing
scsilun_to_int.

Re: [PATCH] zfcp: Report FCP LUN to SCSI midlayer

[James Bottomley]

On Tue, 2007-06-19 at 18:12 +0100, Christoph Hellwig wrote:
> fcp_lun is an unsigned long long (and should be a __be64), so casting
> this to a struct type is not very nice.  Care to add a version that
> takes
> a __be64 intead?  In fact using that variant in scsi_scan.c might be
> benefical aswell, so you could aswell just convert over the existing
> scsilun_to_int. 

Actually, I don't think this is necessary for zfcp: all of these lun
values are input by a user and translated using a strtoull() so it's
going to get highly confusing trying to keep the be64 label [whether
it's desirable for s390 people to be entering BE LUN values is another
matter].  I'd really rather not encourage the use of __be64 u64 for SCSI
luns because it's asking for alignment issues ... instead, the internal
struct scsi_lun contains all the necessary information, and is a stream
of u8 in bus order.

James