Re: [PATCH 2.6.13 5/14] sas-class: sas_discover.c Discover process (end devices)

[Luben Tuikov <luben_tuikov@adaptec.com>]

On 09/13/05 15:22, James Bottomley wrote:
> On Mon, 2005-09-12 at 11:46 -0700, Patrick Mansfield wrote:
> 
>>Though we still have problems with scsi_report_lun_scan code like:
>>
>>                } else if (lun > sdev->host->max_lun) {
>>
>>max_lun just has to be large, at least greater than 0xc001 (49153), maybe
>>even 0xffffffff, correct?
>>
>>But then some sequential scanning could take a while. Maybe the above
>>check is not needed.
> 
> 
> Try this as a straw horse for doing full u64 luns.

James, this patch is wrong.

A SCSI LUN is not "u64 lun", it has never been and it will
never be.

A SCSI LUN is "u8 LUN[8]" -- it is this from the Application
Layer down to the _transport layer_ (if you cared to look at
_any_ LL transport).

(It is also capitalized since it is an abbreviation.)

To compare/print it, please use, as shown at the top of the
file "sas.h":

(be64_to_cpu(*(__be64 *)(_x)))

where _x is only the "LUN" of the definition above.

If you want to print it, please use "%016llx".

It also appears that you've never compiled your patch on
x86_64.

Alternatively, you can take a look at the SAS Layer.

	Luben

> 
> I've converted all the mid-layer and the ULDs; I ran out of steam at the
> lld's.
> 
> This should work transparently for all luns up to 255 (using
> representation 00b), so I've limited all of our sequential LUN scans to
> 255
> 
> This actually boots ... but I don't have a system with >1 LUN currently.
> 
> James

[cut]

> diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h
> --- a/include/scsi/scsi_device.h
> +++ b/include/scsi/scsi_device.h
> @@ -66,7 +66,8 @@ struct scsi_device {
>  					   jiffie count on our counter, they
>  					   could all be from the same event. */
>  
> -	unsigned int id, lun, channel;
> +	unsigned int id, channel;
> +	u64 lun;
>  
>  	unsigned int manufacturer;	/* Manufacturer of device, for using 
>  					 * vendor-specific cmd's */
> @@ -179,20 +180,20 @@ static inline struct scsi_target *scsi_t
>  extern struct scsi_device *__scsi_add_device(struct Scsi_Host *,
>  		uint, uint, uint, void *hostdata);
>  extern int scsi_add_device(struct Scsi_Host *host, uint channel,
> -			   uint target, uint lun);
> +			   uint target, u64 lun);
>  extern void scsi_remove_device(struct scsi_device *);
>  extern int scsi_device_cancel(struct scsi_device *, int);
>  
>  extern int scsi_device_get(struct scsi_device *);
>  extern void scsi_device_put(struct scsi_device *);
>  extern struct scsi_device *scsi_device_lookup(struct Scsi_Host *,
> -					      uint, uint, uint);
> +					      uint, uint, u64);
>  extern struct scsi_device *__scsi_device_lookup(struct Scsi_Host *,
> -						uint, uint, uint);
> +						uint, uint, u64);
>  extern struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *,
> -							uint);
> +							u64);
>  extern struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *,
> -							  uint);
> +							  u64);
>  extern void starget_for_each_device(struct scsi_target *, void *,
>  		     void (*fn)(struct scsi_device *, void *));
>  
> @@ -248,12 +249,13 @@ extern void scsi_device_resume(struct sc
>  extern void scsi_target_quiesce(struct scsi_target *);
>  extern void scsi_target_resume(struct scsi_target *);
>  extern void scsi_scan_target(struct device *parent, unsigned int channel,
> -			     unsigned int id, unsigned int lun, int rescan);
> +			     unsigned int id, u64 lun, int rescan);
>  extern void scsi_target_reap(struct scsi_target *);
>  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 void int_to_scsilun(u64, struct scsi_lun *);
> +extern u64 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 *);
> diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
> --- a/include/scsi/scsi_host.h
> +++ b/include/scsi/scsi_host.h
> @@ -494,7 +494,10 @@ struct Scsi_Host {
>  	 * or lun (i.e. 8 for normal systems).
>  	 */
>  	unsigned int max_id;
> -	unsigned int max_lun;
> +	#define SCSI_UNLIMITED_LUNS	(0xffffffffffffffffULL)
> +	/* Any luns beyond 255 *require* report luns to find */
> +	#define SCSI_SCAN_LIMIT_LUNS	256
> +	u64 max_lun;
>  	unsigned int max_channel;
>  
>  	/*
> 
> 
>