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Commit 01b291bd authored by James Bottomley's avatar James Bottomley
Browse files

[SCSI] fix check of PQ and PDT bits for WLUNs 



For IBM z series certain LUNs can no longer be accessed.

This is because kernel version 2.6.19 a check was introduced not to
create a generic SCSI device for devices that return PQ=1 and
PDT=0x1f. For WLUNs (see SAM-3, p. 41ff) generic SCSI devices should
be created unconditionally without looking at the PQ bit, so add a
check for WLUNs in with this test.

Acked-by: default avatarMartin Petermann <martin@linux.vnet.ibm.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent bb0003c1

drivers/scsi/scsi_scan.c

+2 −1
Original line number Diff line number Diff line
@@ -1080,7 +1080,8 @@ static int scsi_probe_and_add_lun(struct scsi_target *starget, 
	 * PDT=1Fh none (no FDD connected to the requested logical unit)

	 */

	if (((result[0] >> 5) == 1 || starget->pdt_1f_for_no_lun) &&

	     (result[0] & 0x1f) == 0x1f) {

	    (result[0] & 0x1f) == 0x1f &&

	    !scsi_is_wlun(lun)) {

		SCSI_LOG_SCAN_BUS(3, printk(KERN_INFO

					"scsi scan: peripheral device type"

					" of 31, no device added\n"));

include/scsi/scsi.h

+14 −0
Original line number Diff line number Diff line
@@ -308,6 +308,20 @@ struct scsi_lun { 
	__u8 scsi_lun[8];

};



/*

 * The Well Known LUNS (SAM-3) in our int representation of a LUN

 */

#define SCSI_W_LUN_BASE 0xc100

#define SCSI_W_LUN_REPORT_LUNS (SCSI_W_LUN_BASE + 1)

#define SCSI_W_LUN_ACCESS_CONTROL (SCSI_W_LUN_BASE + 2)

#define SCSI_W_LUN_TARGET_LOG_PAGE (SCSI_W_LUN_BASE + 3)



static inline int scsi_is_wlun(unsigned int lun)

{

	return (lun & 0xff00) == SCSI_W_LUN_BASE;

}





/*

 *  MESSAGE CODES

 */