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.
Signed-off-by: Douglas Gilbert <dgilbert@xxxxxxxxxxxx>
---
drivers/scsi/scsi_debug.c | 86 +++++++++++++++++++++++++++++++++++++++++++++--
1 file changed, 83 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 09ba494f8896..a573012524b3 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -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 "1.87"
+static const char *sdebug_version_date = "20171105";
#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 +799,62 @@ 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;
@@ -3660,6 +3718,7 @@ 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;
}
@@ -4141,6 +4200,7 @@ 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, S_IRUGO | S_IWUSR);
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);
@@ -4192,6 +4252,7 @@ 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)");
@@ -4875,6 +4936,24 @@ 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 n;
+
+ if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
+ sdebug_cdb_len = n;
+ all_config_cdb_len();
+ return count;
+ }
+ return -EINVAL;
+}
+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
@@ -4914,6 +4993,7 @@ 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);
--
2.14.1
