Re: [PATCH] ALUA support for scsi_debug

Douglas Gilbert
2006-10-18T20:16:50Z

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Hannes Reinecke wrote:
> Hi all,
>
> I've hacked up scsi_debug to support REPORT TARGET PORT GROUPS.
> In combination with vpd_use_hostno=0 it'll now support multipathing
> nicely.
> Doug, there is reference to port_a and port_b in the VPD page support.
> However, port_b appearently is just a fake entry with no (virtual)
> device backing.
> We could eg use the 'channel' value to refer the relative port number,
> so that host & channel act as a fan-out for multipathing.
>
> James, please apply.

Not quite yet ...

Hannes,
Here is my counter patch for you to consider.
I suspect my machine was running into stack
problems so I moved some arrays onto the heap.

You will see some other small changes if you
compare the two patches. My patch is against
lk 2.6.19-rc2

Doug Gilbert

[-- Attachment #2: sdebug_2619rc2alua2.diff --]
[-- Type: text/x-patch, Size: 8548 bytes --]

--- linux/include/scsi/scsi.h 2006-10-18 15:35:44.000000000 -0400
+++ linux/include/scsi/scsi.h2619rc2alua 2006-10-18 15:36:26.000000000 -0400
@@ -97,6 +97,7 @@
#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
@@ -114,6 +115,8 @@
#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 */
--- linux/drivers/scsi/scsi_debug.c 2006-10-07 10:26:01.000000000 -0400
+++ linux/drivers/scsi/scsi_debug.c2619rc2alua2 2006-10-18 14:55:19.000000000 -0400
@@ -52,7 +52,7 @@
#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
@@ -254,6 +254,8 @@
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,
@@ -287,9 +289,9 @@
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 target_port_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);
@@ -422,6 +424,15 @@
}
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:
case READ_10:
@@ -665,8 +676,9 @@
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 target_port_id,
+ int target_dev_id, int dev_id_num,
+ const char * dev_id_str,
int dev_id_str_len)
{
int num, port_a;
@@ -720,6 +732,15 @@
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++] = (target_port_id >> 8) & 0xff;
+ arr[num++] = target_port_id & 0xff;
/* NAA-5, Target device identifier */
arr[num++] = 0x61; /* proto=sas, binary */
arr[num++] = 0xa3; /* piv=1, target device, naa */
@@ -928,12 +949,12 @@
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))
@@ -944,12 +965,14 @@
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, target_port_id, target_dev_id, len;
char lu_id_str[6];
int host_no = devip->sdbg_host->shost->host_no;

+ target_port_id = (host_no + 1);
if (0 == scsi_debug_vpd_use_hostno)
host_no = 0;
lu_id_num = devip->wlun ? -1 : (((host_no + 1) * 2000) +
@@ -977,8 +1000,9 @@
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], target_port_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]);
@@ -1012,17 +1036,22 @@
/* 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 */
@@ -1039,8 +1068,10 @@
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,
@@ -1171,6 +1202,73 @@
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 n, ret, alloc_len, rlen, target_port_id, target_dev_id, port_a;
+
+ alloc_len = ((cmd[6] << 24) + (cmd[7] << 16) + (cmd[8] << 8)
+ + cmd[9]);
+ if (alloc_len < 4 + 11) {
+ mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
+ 0);
+ return check_condition_result;
+ }
+
+ arr = kzalloc(SDEBUG_MAX_TGTPGS_ARR_SZ, GFP_KERNEL);
+ n = 4;
+ /*
+ * Each host has it's own target port group.
+ * The asymmetric access state is cycled according to the host_id.
+ */
+
+ /* Construct target port group descriptors */
+ target_dev_id = ((devip->sdbg_host->shost->host_no + 1) * 2000) +
+ (devip->target * 1000) - 3;
+ port_a = target_dev_id + 1;
+ target_port_id = devip->sdbg_host->shost->host_no + 1;
+ /* We can only support ALUA if the hostno is ignored */
+ if (0 == scsi_debug_vpd_use_hostno) {
+ arr[n++] = target_port_id % 4; /* Asymm access state */
+ arr[n++] = 0x0F; /* claim: all states are supported */
+ } else {
+ arr[n++] = 0x0; /* Optimal path */
+ arr[n++] = 0x08; /* We only have optimal paths */
+ }
+ arr[n++] = (target_port_id >> 8) & 0xff;
+ arr[n++] = target_port_id & 0xff;
+ arr[n++] = 0; /* Reserved */
+ arr[n++] = 0; /* Status code */
+ arr[n++] = 0; /* Vendor unique */
+ arr[n++] = 0x1; /* count. Why not scsi_debug_num_tgts? */
+ arr[n++] = 0; /* Reserved */
+ arr[n++] = 0; /* Reserved */
+ arr[n++] = (port_a >> 8) & 0xff;
+ arr[n++] = port_a & 0xff;
+
+ rlen = n - 4;
+ arr[0] = (rlen >> 24) & 0xff;
+ arr[1] = (rlen >> 16) & 0xff;
+ arr[2] = (rlen >> 8) & 0xff;
+ arr[3] = rlen & 0xff;
+
+ if (alloc_len < n) {
+ mk_sense_buffer(devip, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB,
+ 0);
+ kfree(arr);
+ return check_condition_result;
+ }
+
+ ret = fill_from_dev_buffer(scp, arr,
+ min(n, SDEBUG_MAX_TGTPGS_ARR_SZ));
+ kfree(arr);
+ return ret;
+}
+
/* <<Following mode page info copied from ST318451LW>> */

static int resp_err_recov_pg(unsigned char * p, int pcontrol, int target)