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Commit d9e5d618 authored by Hannes Reinecke's avatar Hannes Reinecke Committed by Christoph Hellwig
Browse files

scsi_scan: Fixup scsilun_to_int() 



scsilun_to_int() has an error which prevents it from generating
correct LUN numbers for 64bit values.
Also we should remove the misleading comment about portions of
the LUN being ignored; the initiator should treat the LUN as
an opaque value.
And, finally, the example given should use the correct
prefix (here: extended flat space addressing scheme).

This patch includes the modifications suggested by
Bart van Assche.

Cc: Bart van Assche <bvanassche@acm.org>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: default avatarHannes Reinecke <hare@suse.de>
Reviewed-by: default avatarJames Bottomley <jbottomley@parallels.com>
Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 1abf635d

drivers/scsi/scsi_scan.c

+10 −12
Original line number Diff line number Diff line
@@ -1263,14 +1263,15 @@ static void scsi_sequential_lun_scan(struct scsi_target *starget, 
 *     truncation before using this function.

 *

 * Notes:

 *     The struct scsi_lun is assumed to be four levels, with each level

 *     effectively containing a SCSI byte-ordered (big endian) short; the

 *     addressing bits of each level are ignored (the highest two bits).

 *     For a description of the LUN format, post SCSI-3 see the SCSI

 *     Architecture Model, for SCSI-3 see the SCSI Controller Commands.

 *

 *     Given a struct scsi_lun of: 0a 04 0b 03 00 00 00 00, this function returns

 *     the integer: 0x0b030a04

 *     Given a struct scsi_lun of: d2 04 0b 03 00 00 00 00, this function

 *     returns the integer: 0x0b03d204

 *

 *     This encoding will return a standard integer LUN for LUNs smaller

 *     than 256, which typically use a single level LUN structure with

 *     addressing method 0.

 **/

u64 scsilun_to_int(struct scsi_lun *scsilun)

{
@@ -1279,8 +1280,8 @@ u64 scsilun_to_int(struct scsi_lun *scsilun) 


	lun = 0;

	for (i = 0; i < sizeof(lun); i += 2)

		lun = lun | (((scsilun->scsi_lun[i] << 8) |

			      scsilun->scsi_lun[i + 1]) << (i * 8));

		lun = lun | (((u64)scsilun->scsi_lun[i] << ((i + 1) * 8)) |

			     ((u64)scsilun->scsi_lun[i + 1] << (i * 8)));

	return lun;

}

EXPORT_SYMBOL(scsilun_to_int);
@@ -1294,13 +1295,10 @@ EXPORT_SYMBOL(scsilun_to_int); 
 *     Reverts the functionality of the scsilun_to_int, which packed

 *     an 8-byte lun value into an int. This routine unpacks the int

 *     back into the lun value.

 *     Note: the scsilun_to_int() routine does not truly handle all

 *     8bytes of the lun value. This functions restores only as much

 *     as was set by the routine.

 *

 * Notes:

 *     Given an integer : 0x0b030a04,  this function returns a

 *     scsi_lun of : struct scsi_lun of: 0a 04 0b 03 00 00 00 00

 *     Given an integer : 0x0b03d204,  this function returns a

 *     struct scsi_lun of: d2 04 0b 03 00 00 00 00

 *

 **/

void int_to_scsilun(u64 lun, struct scsi_lun *scsilun)