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scsi: scsi_debug: add cdb_len parameter 

While testing "sd: Micro-optimize READ / WRITE CDB encoding" patches it
was helpful to check various code paths associated with READ/WRITE 6, 10
and 16 byte cdb variants. There seems to be no user space "knobs" to
twiddle use_10_for_rw and friends in the scsi_device structure.  So add
a parameter to scsi_debug called "cdb_len" for this purpose.

[mkp: fixed typo]

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
This commit is contained in:
Douglas Gilbert 2017-12-05 00:05:49 -05:00 committed by Martin K. Petersen
parent 4b1d8e7861
commit 9b760fd877
1 changed files with 87 additions and 5 deletions
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92
drivers/scsi/scsi_debug.c
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@ -6,7 +6,7 @@
* anything out of the ordinary is seen.
* ^^^^^^^^^^^^^^^^^^^^^^^ Original ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
*
* Copyright (C) 2001 - 2016 Douglas Gilbert
* Copyright (C) 2001 - 2017 Douglas Gilbert
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@ -61,8 +61,8 @@
#include "scsi_logging.h"
/* make sure inq_product_rev string corresponds to this version */
#define SDEBUG_VERSION "1.86"
static const char *sdebug_version_date = "20160430";
#define SDEBUG_VERSION "0187" /* format to fit INQUIRY revision field */
static const char *sdebug_version_date = "20171202";
#define MY_NAME "scsi_debug"
@ -105,6 +105,7 @@ static const char *sdebug_version_date = "20160430";
* (id 0) containing 1 logical unit (lun 0). That is 1 device.
*/
#define DEF_ATO 1
#define DEF_CDB_LEN 10
#define DEF_JDELAY 1 /* if > 0 unit is a jiffy */
#define DEF_DEV_SIZE_MB 8
#define DEF_DIF 0
@ -571,6 +572,7 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
static int sdebug_add_host = DEF_NUM_HOST;
static int sdebug_ato = DEF_ATO;
static int sdebug_cdb_len = DEF_CDB_LEN;
static int sdebug_jdelay = DEF_JDELAY; /* if > 0 then unit is jiffies */
static int sdebug_dev_size_mb = DEF_DEV_SIZE_MB;
static int sdebug_dif = DEF_DIF;
@ -797,6 +799,61 @@ static int scsi_debug_ioctl(struct scsi_device *dev, int cmd, void __user *arg)
/* return -ENOTTY; // correct return but upsets fdisk */
}
static void config_cdb_len(struct scsi_device *sdev)
{
switch (sdebug_cdb_len) {
case 6: /* suggest 6 byte READ, WRITE and MODE SENSE/SELECT */
sdev->use_10_for_rw = false;
sdev->use_16_for_rw = false;
sdev->use_10_for_ms = false;
break;
case 10: /* suggest 10 byte RWs and 6 byte MODE SENSE/SELECT */
sdev->use_10_for_rw = true;
sdev->use_16_for_rw = false;
sdev->use_10_for_ms = false;
break;
case 12: /* suggest 10 byte RWs and 10 byte MODE SENSE/SELECT */
sdev->use_10_for_rw = true;
sdev->use_16_for_rw = false;
sdev->use_10_for_ms = true;
break;
case 16:
sdev->use_10_for_rw = false;
sdev->use_16_for_rw = true;
sdev->use_10_for_ms = true;
break;
case 32: /* No knobs to suggest this so same as 16 for now */
sdev->use_10_for_rw = false;
sdev->use_16_for_rw = true;
sdev->use_10_for_ms = true;
break;
default:
pr_warn("unexpected cdb_len=%d, force to 10\n",
sdebug_cdb_len);
sdev->use_10_for_rw = true;
sdev->use_16_for_rw = false;
sdev->use_10_for_ms = false;
sdebug_cdb_len = 10;
break;
}
}
static void all_config_cdb_len(void)
{
struct sdebug_host_info *sdbg_host;
struct Scsi_Host *shost;
struct scsi_device *sdev;
spin_lock(&sdebug_host_list_lock);
list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {
shost = sdbg_host->shost;
shost_for_each_device(sdev, shost) {
config_cdb_len(sdev);
}
}
spin_unlock(&sdebug_host_list_lock);
}
static void clear_luns_changed_on_target(struct sdebug_dev_info *devip)
{
struct sdebug_host_info *sdhp;
@ -955,7 +1012,7 @@ static int fetch_to_dev_buffer(struct scsi_cmnd *scp, unsigned char *arr,
static char sdebug_inq_vendor_id[9] = "Linux ";
static char sdebug_inq_product_id[17] = "scsi_debug ";
static char sdebug_inq_product_rev[5] = "0186"; /* version less '.' */
static char sdebug_inq_product_rev[5] = SDEBUG_VERSION;
/* Use some locally assigned NAAs for SAS addresses. */
static const u64 naa3_comp_a = 0x3222222000000000ULL;
static const u64 naa3_comp_b = 0x3333333000000000ULL;
@ -1411,6 +1468,8 @@ static int resp_inquiry(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
memcpy(&arr[8], sdebug_inq_vendor_id, 8);
memcpy(&arr[16], sdebug_inq_product_id, 16);
memcpy(&arr[32], sdebug_inq_product_rev, 4);
/* Use Vendor Specific area to place driver date in ASCII hex */
memcpy(&arr[36], sdebug_version_date, 8);
/* version descriptors (2 bytes each) follow */
put_unaligned_be16(0xc0, arr + 58); /* SAM-6 no version claimed */
put_unaligned_be16(0x5c0, arr + 60); /* SPC-5 no version claimed */
@ -3660,6 +3719,7 @@ static int scsi_debug_slave_configure(struct scsi_device *sdp)
blk_queue_max_segment_size(sdp->request_queue, -1U);
if (sdebug_no_uld)
sdp->no_uld_attach = 1;
config_cdb_len(sdp);
return 0;
}
@ -4138,6 +4198,7 @@ static int schedule_resp(struct scsi_cmnd *cmnd, struct sdebug_dev_info *devip,
*/
module_param_named(add_host, sdebug_add_host, int, S_IRUGO | S_IWUSR);
module_param_named(ato, sdebug_ato, int, S_IRUGO);
module_param_named(cdb_len, sdebug_cdb_len, int, 0644);
module_param_named(clustering, sdebug_clustering, bool, S_IRUGO | S_IWUSR);
module_param_named(delay, sdebug_jdelay, int, S_IRUGO | S_IWUSR);
module_param_named(dev_size_mb, sdebug_dev_size_mb, int, S_IRUGO);
@ -4195,6 +4256,7 @@ MODULE_VERSION(SDEBUG_VERSION);
MODULE_PARM_DESC(add_host, "0..127 hosts allowed(def=1)");
MODULE_PARM_DESC(ato, "application tag ownership: 0=disk 1=host (def=1)");
MODULE_PARM_DESC(cdb_len, "suggest CDB lengths to drivers (def=10)");
MODULE_PARM_DESC(clustering, "when set enables larger transfers (def=0)");
MODULE_PARM_DESC(delay, "response delay (def=1 jiffy); 0:imm, -1,-2:tiny");
MODULE_PARM_DESC(dev_size_mb, "size in MiB of ram shared by devs(def=8)");
@ -4207,7 +4269,8 @@ MODULE_PARM_DESC(guard, "protection checksum: 0=crc, 1=ip (def=0)");
MODULE_PARM_DESC(host_lock, "host_lock is ignored (def=0)");
MODULE_PARM_DESC(inq_vendor, "SCSI INQUIRY vendor string (def=\"Linux\")");
MODULE_PARM_DESC(inq_product, "SCSI INQUIRY product string (def=\"scsi_debug\")");
MODULE_PARM_DESC(inq_rev, "SCSI INQUIRY revision string (def=\"0186\")");
MODULE_PARM_DESC(inq_rev, "SCSI INQUIRY revision string (def=\""
SDEBUG_VERSION "\")");
MODULE_PARM_DESC(lbpu, "enable LBP, support UNMAP command (def=0)");
MODULE_PARM_DESC(lbpws, "enable LBP, support WRITE SAME(16) with UNMAP bit (def=0)");
MODULE_PARM_DESC(lbpws10, "enable LBP, support WRITE SAME(10) with UNMAP bit (def=0)");
@ -4881,6 +4944,24 @@ static ssize_t uuid_ctl_show(struct device_driver *ddp, char *buf)
}
static DRIVER_ATTR_RO(uuid_ctl);
static ssize_t cdb_len_show(struct device_driver *ddp, char *buf)
{
return scnprintf(buf, PAGE_SIZE, "%d\n", sdebug_cdb_len);
}
static ssize_t cdb_len_store(struct device_driver *ddp, const char *buf,
size_t count)
{
int ret, n;
ret = kstrtoint(buf, 0, &n);
if (ret)
return ret;
sdebug_cdb_len = n;
all_config_cdb_len();
return count;
}
static DRIVER_ATTR_RW(cdb_len);
/* Note: The following array creates attribute files in the
/sys/bus/pseudo/drivers/scsi_debug directory. The advantage of these
@ -4920,6 +5001,7 @@ static struct attribute *sdebug_drv_attrs[] = {
&driver_attr_ndelay.attr,
&driver_attr_strict.attr,
&driver_attr_uuid_ctl.attr,
&driver_attr_cdb_len.attr,
NULL,
};
ATTRIBUTE_GROUPS(sdebug_drv);