[SCSI] scsi_debug: support REPORT TARGET PORT GROUPS

This patch adds support for REPORT TARGET PORT GROUPS. This is used
eg for the multipathing priority callout to determine the path
priority.
With this patch multipath-tools can use the existing mpath_prio_alua
callout to exercise the path priority grouping.

Signed-off-by: Hannes Reinecke <[e-mail]>
Signed-off-by: Douglas Gilbert <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/scsi_debug.c

···
 #include "scsi_debug.h"
 
 #define SCSI_DEBUG_VERSION "1.80"
-static const char * scsi_debug_version_date = "20060914";
+static const char * scsi_debug_version_date = "20061018";
 
 /* Additional Sense Code (ASC) used */
 #define NO_ADDITIONAL_SENSE 0x0
···
 			 struct sdebug_dev_info * devip);
 static int resp_start_stop(struct scsi_cmnd * scp,
 			   struct sdebug_dev_info * devip);
+static int resp_report_tgtpgs(struct scsi_cmnd * scp,
+			      struct sdebug_dev_info * devip);
 static int resp_readcap(struct scsi_cmnd * SCpnt,
 			struct sdebug_dev_info * devip);
 static int resp_readcap16(struct scsi_cmnd * SCpnt,
···
 static void __init init_all_queued(void);
 static void stop_all_queued(void);
 static int stop_queued_cmnd(struct scsi_cmnd * cmnd);
-static int inquiry_evpd_83(unsigned char * arr, int target_dev_id,
-			   int dev_id_num, const char * dev_id_str,
-			   int dev_id_str_len);
+static int inquiry_evpd_83(unsigned char * arr, int port_group_id,
+			   int target_dev_id, int dev_id_num,
+			   const char * dev_id_str, int dev_id_str_len);
 static int inquiry_evpd_88(unsigned char * arr, int target_dev_id);
 static int do_create_driverfs_files(void);
 static void do_remove_driverfs_files(void);
···
 			break;
 		}
 		errsts = resp_readcap16(SCpnt, devip);
+		break;
+	case MAINTENANCE_IN:
+		if (MI_REPORT_TARGET_PGS != cmd[1]) {
+			mk_sense_buffer(devip, ILLEGAL_REQUEST,
+					INVALID_OPCODE, 0);
+			errsts = check_condition_result;
+			break;
+		}
+		errsts = resp_report_tgtpgs(SCpnt, devip);
 		break;
 	case READ_16:
 	case READ_12:
···
 static const char * inq_product_id = "scsi_debug      ";
 static const char * inq_product_rev = "0004";
 
-static int inquiry_evpd_83(unsigned char * arr, int target_dev_id,
-			   int dev_id_num, const char * dev_id_str,
+static int inquiry_evpd_83(unsigned char * arr, int port_group_id,
+			   int target_dev_id, int dev_id_num,
+			   const char * dev_id_str,
 			   int dev_id_str_len)
 {
 	int num, port_a;
···
 	arr[num++] = (port_a >> 16) & 0xff;
 	arr[num++] = (port_a >> 8) & 0xff;
 	arr[num++] = port_a & 0xff;
+	/* NAA-5, Target port group identifier */
+	arr[num++] = 0x61;	/* proto=sas, binary */
+	arr[num++] = 0x95;	/* piv=1, target port group id */
+	arr[num++] = 0x0;
+	arr[num++] = 0x4;
+	arr[num++] = 0;
+	arr[num++] = 0;
+	arr[num++] = (port_group_id >> 8) & 0xff;
+	arr[num++] = port_group_id & 0xff;
 	/* NAA-5, Target device identifier */
 	arr[num++] = 0x61;	/* proto=sas, binary */
 	arr[num++] = 0xa3;	/* piv=1, target device, naa */
···
 			struct sdebug_dev_info * devip)
 {
 	unsigned char pq_pdt;
-	unsigned char arr[SDEBUG_MAX_INQ_ARR_SZ];
+	unsigned char * arr;
 	unsigned char *cmd = (unsigned char *)scp->cmnd;
-	int alloc_len, n;
+	int alloc_len, n, ret;
 
 	alloc_len = (cmd[3] << 8) + cmd[4];
-	memset(arr, 0, SDEBUG_MAX_INQ_ARR_SZ);
+	arr = kzalloc(SDEBUG_MAX_INQ_ARR_SZ, GFP_KERNEL);
 	if (devip->wlun)
 		pq_pdt = 0x1e;	/* present, wlun */
 	else if (scsi_debug_no_lun_0 && (0 == devip->lun))
···
 	if (0x2 & cmd[1]) {  /* CMDDT bit set */
 		mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
 			       	0);
+		kfree(arr);
 		return check_condition_result;
 	} else if (0x1 & cmd[1]) {  /* EVPD bit set */
-		int lu_id_num, target_dev_id, len;
+		int lu_id_num, port_group_id, target_dev_id, len;
 		char lu_id_str[6];
 		int host_no = devip->sdbg_host->shost->host_no;
 		
+		port_group_id = (((host_no + 1) & 0x7f) << 8) +
+		    (devip->channel & 0x7f);
 		if (0 == scsi_debug_vpd_use_hostno)
 			host_no = 0;
 		lu_id_num = devip->wlun ? -1 : (((host_no + 1) * 2000) +
···
 			memcpy(&arr[4], lu_id_str, len);
 		} else if (0x83 == cmd[2]) { /* device identification */
 			arr[1] = cmd[2];	/*sanity */
-			arr[3] = inquiry_evpd_83(&arr[4], target_dev_id,
-						 lu_id_num, lu_id_str, len);
+			arr[3] = inquiry_evpd_83(&arr[4], port_group_id,
+						 target_dev_id, lu_id_num,
+						 lu_id_str, len);
 		} else if (0x84 == cmd[2]) { /* Software interface ident. */
 			arr[1] = cmd[2];	/*sanity */
 			arr[3] = inquiry_evpd_84(&arr[4]);
···
 			/* Illegal request, invalid field in cdb */
 			mk_sense_buffer(devip, ILLEGAL_REQUEST,
 					INVALID_FIELD_IN_CDB, 0);
+			kfree(arr);
 			return check_condition_result;
 		}
 		len = min(((arr[2] << 8) + arr[3]) + 4, alloc_len);
-		return fill_from_dev_buffer(scp, arr,
+		ret = fill_from_dev_buffer(scp, arr,
 			    min(len, SDEBUG_MAX_INQ_ARR_SZ));
+		kfree(arr);
+		return ret;
 	}
 	/* drops through here for a standard inquiry */
 	arr[1] = DEV_REMOVEABLE(target) ? 0x80 : 0;	/* Removable disk */
 	arr[2] = scsi_debug_scsi_level;
 	arr[3] = 2;    /* response_data_format==2 */
 	arr[4] = SDEBUG_LONG_INQ_SZ - 5;
+	if (0 == scsi_debug_vpd_use_hostno)
+		arr[5] = 0x10; /* claim: implicit TGPS */
 	arr[6] = 0x10; /* claim: MultiP */
 	/* arr[6] |= 0x40; ... claim: EncServ (enclosure services) */
 	arr[7] = 0xa; /* claim: LINKED + CMDQUE */
···
 		arr[n++] = 0x3; arr[n++] = 0x60; /* SSC-2 no version */
 	}
 	arr[n++] = 0xc; arr[n++] = 0xf;  /* SAS-1.1 rev 10 */
-	return fill_from_dev_buffer(scp, arr,
+	ret = fill_from_dev_buffer(scp, arr,
 			    min(alloc_len, SDEBUG_LONG_INQ_SZ));
+	kfree(arr);
+	return ret;
 }
 
 static int resp_requests(struct scsi_cmnd * scp,
···
 	arr[11] = SECT_SIZE_PER(target) & 0xff;
 	return fill_from_dev_buffer(scp, arr,
 				    min(alloc_len, SDEBUG_READCAP16_ARR_SZ));
+}
+
+#define SDEBUG_MAX_TGTPGS_ARR_SZ 1412
+
+static int resp_report_tgtpgs(struct scsi_cmnd * scp,
+			      struct sdebug_dev_info * devip)
+{
+	unsigned char *cmd = (unsigned char *)scp->cmnd;
+	unsigned char * arr;
+	int host_no = devip->sdbg_host->shost->host_no;
+	int n, ret, alen, rlen;
+	int port_group_a, port_group_b, port_a, port_b;
+
+	alen = ((cmd[6] << 24) + (cmd[7] << 16) + (cmd[8] << 8)
+		+ cmd[9]);
+
+	arr = kzalloc(SDEBUG_MAX_TGTPGS_ARR_SZ, GFP_KERNEL);
+	/*
+	 * EVPD page 0x88 states we have two ports, one
+	 * real and a fake port with no device connected.
+	 * So we create two port groups with one port each
+	 * and set the group with port B to unavailable.
+	 */
+	port_a = 0x1; /* relative port A */
+	port_b = 0x2; /* relative port B */
+	port_group_a = (((host_no + 1) & 0x7f) << 8) +
+	    (devip->channel & 0x7f);
+	port_group_b = (((host_no + 1) & 0x7f) << 8) +
+	    (devip->channel & 0x7f) + 0x80;
+
+	/*
+	 * The asymmetric access state is cycled according to the host_id.
+	 */
+	n = 4;
+	if (0 == scsi_debug_vpd_use_hostno) {
+	    arr[n++] = host_no % 3; /* Asymm access state */
+	    arr[n++] = 0x0F; /* claim: all states are supported */
+	} else {
+	    arr[n++] = 0x0; /* Active/Optimized path */
+	    arr[n++] = 0x01; /* claim: only support active/optimized paths */
+	}
+	arr[n++] = (port_group_a >> 8) & 0xff;
+	arr[n++] = port_group_a & 0xff;
+	arr[n++] = 0;    /* Reserved */
+	arr[n++] = 0;    /* Status code */
+	arr[n++] = 0;    /* Vendor unique */
+	arr[n++] = 0x1;  /* One port per group */
+	arr[n++] = 0;    /* Reserved */
+	arr[n++] = 0;    /* Reserved */
+	arr[n++] = (port_a >> 8) & 0xff;
+	arr[n++] = port_a & 0xff;
+	arr[n++] = 3;    /* Port unavailable */
+	arr[n++] = 0x08; /* claim: only unavailalbe paths are supported */
+	arr[n++] = (port_group_b >> 8) & 0xff;
+	arr[n++] = port_group_b & 0xff;
+	arr[n++] = 0;    /* Reserved */
+	arr[n++] = 0;    /* Status code */
+	arr[n++] = 0;    /* Vendor unique */
+	arr[n++] = 0x1;  /* One port per group */
+	arr[n++] = 0;    /* Reserved */
+	arr[n++] = 0;    /* Reserved */
+	arr[n++] = (port_b >> 8) & 0xff;
+	arr[n++] = port_b & 0xff;
+
+	rlen = n - 4;
+	arr[0] = (rlen >> 24) & 0xff;
+	arr[1] = (rlen >> 16) & 0xff;
+	arr[2] = (rlen >> 8) & 0xff;
+	arr[3] = rlen & 0xff;
+
+	/*
+	 * Return the smallest value of either
+	 * - The allocated length
+	 * - The constructed command length
+	 * - The maximum array size
+	 */
+	rlen = min(alen,n);
+	ret = fill_from_dev_buffer(scp, arr,
+				   min(rlen, SDEBUG_MAX_TGTPGS_ARR_SZ));
+	kfree(arr);
+	return ret;
 }
 
 /* <<Following mode page info copied from ST318451LW>> */

include/scsi/scsi.h

···
 #define PERSISTENT_RESERVE_IN 0x5e
 #define PERSISTENT_RESERVE_OUT 0x5f
 #define REPORT_LUNS           0xa0
+#define MAINTENANCE_IN        0xa3
 #define MOVE_MEDIUM           0xa5
 #define EXCHANGE_MEDIUM       0xa6
 #define READ_12               0xa8
···
 #define SERVICE_ACTION_IN     0x9e
 /* values for service action in */
 #define	SAI_READ_CAPACITY_16  0x10
+/* values for maintenance in */
+#define MI_REPORT_TARGET_PGS  0x0a
 
 /* Values for T10/04-262r7 */
 #define	ATA_16		      0x85	/* 16-byte pass-thru */