[PATCH v3 0/5] scsi_debug: add write scattered support

[PATCH v3 0/5] scsi_debug: add write scattered support

[Douglas Gilbert]

While testing the WRITE SCATTERED command support in a new sg3_utils
utility (sg_write_x) it was helpful to have a target that supported
this command. This command might be attractive to other kernel
subsystems. Even if end devices don't support this command yet, it
would most likely be a performance win if SCSI LLDs supported it (by
breaking it down to a series of WRITE commands), as that would cut
down the overhead of the block layer, the ULD (e.g. sd) and the SCSI
midlevel.

Changes since v2:
  - remove over-zealous sanity check (lbdof >= bt_len) that rejected
    valid invocations
  - change a kzalloc() failure to return SCSI_MLQUEUE_HOST_BUSY as
    requested by reviewer

Changes since original version:
  - fix problem when fake_rw=1, identify media access commands
    better with following rename
  - rename FF_DIRECT_IO to FF_MEDIA_IO
  - apply reviewer suggestions (Bart Van Assche)
  - expand in-code comments

Douglas Gilbert (5):
  scsi_debug: tab, kstrto changes
  scsi_debug: fix group_number mask
  scsi_debug: do_device_access add sg offset argument
  scsi_debug: ARRAY_SIZE and FF_MEDIA_IO
  scsi_debug: add resp_write_scat function

 drivers/scsi/scsi_debug.c | 541 +++++++++++++++++++++++++++++++---------------
 1 file changed, 366 insertions(+), 175 deletions(-)

-- 
2.14.1

[PATCH v3 1/5] scsi_debug: tab, kstrto changes

[Douglas Gilbert]

Some of my development tools tend to add spaces (my preference) rather
than tabs (kernel convention). Running unexpand to clean these spaces
up found more of them than checkpatch.pl did. Then checkpatch.pl
complained about other style violations in those newly tabbed lines.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
---
 drivers/scsi/scsi_debug.c | 174 +++++++++++++++++++++++-----------------------
 1 file changed, 87 insertions(+), 87 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index e4f037f0f38b..80a775b6e648 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -304,8 +304,8 @@ struct opcode_info_t {
 	u32 flags;		/* OR-ed set of SDEB_F_* */
 	int (*pfp)(struct scsi_cmnd *, struct sdebug_dev_info *);
 	const struct opcode_info_t *arrp;  /* num_attached elements or NULL */
-	u8 len_mask[16];	/* len=len_mask[0], then mask for cdb[1]... */
-				/* ignore cdb bytes after position 15 */
+	u8 len_mask[16];	/* len_mask[0]-->cdb_len, then mask for cdb */
+				/* 1 to min(cdb_len, 15); ignore cdb[15...] */
 };
 
 /* SCSI opcodes (first byte of cdb) of interest mapped onto these indexes */
@@ -340,7 +340,7 @@ enum sdeb_opcode_index {
 	SDEB_I_WRITE_SAME = 27,		/* 10, 16 */
 	SDEB_I_SYNC_CACHE = 28,		/* 10 only */
 	SDEB_I_COMP_WRITE = 29,
-	SDEB_I_LAST_ELEMENT = 30,	/* keep this last */
+	SDEB_I_LAST_ELEMENT = 30,	/* keep this last (previous + 1) */
 };
 
 
@@ -1900,7 +1900,7 @@ static unsigned char ctrl_m_pg[] = {0xa, 10, 2, 0, 0, 0, 0, 0,
 static int resp_ctrl_m_pg(unsigned char * p, int pcontrol, int target)
 { 	/* Control mode page for mode_sense */
 	unsigned char ch_ctrl_m_pg[] = {/* 0xa, 10, */ 0x6, 0, 0, 0, 0, 0,
-				        0, 0, 0, 0};
+					0, 0, 0, 0};
 	unsigned char d_ctrl_m_pg[] = {0xa, 10, 2, 0, 0, 0, 0, 0,
 				     0, 0, 0x2, 0x4b};
 
@@ -2077,13 +2077,13 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		len = resp_disconnect_pg(ap, pcontrol, target);
 		offset += len;
 		break;
-        case 0x3:       /* Format device page, direct access */
+	case 0x3:       /* Format device page, direct access */
 		if (is_disk) {
 			len = resp_format_pg(ap, pcontrol, target);
 			offset += len;
 		} else
 			bad_pcode = true;
-                break;
+		break;
 	case 0x8:	/* Caching page, direct access */
 		if (is_disk) {
 			len = resp_caching_pg(ap, pcontrol, target);
@@ -2099,7 +2099,7 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		if ((subpcode > 0x2) && (subpcode < 0xff)) {
 			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
 			return check_condition_result;
-	        }
+		}
 		len = 0;
 		if ((0x0 == subpcode) || (0xff == subpcode))
 			len += resp_sas_sf_m_pg(ap + len, pcontrol, target);
@@ -2136,7 +2136,7 @@ static int resp_mode_sense(struct scsi_cmnd *scp,
 		} else {
 			mk_sense_invalid_fld(scp, SDEB_IN_CDB, 3, -1);
 			return check_condition_result;
-                }
+		}
 		break;
 	default:
 		bad_pcode = true;
@@ -2172,8 +2172,8 @@ static int resp_mode_select(struct scsi_cmnd *scp,
 		mk_sense_invalid_fld(scp, SDEB_IN_CDB, mselect6 ? 4 : 7, -1);
 		return check_condition_result;
 	}
-        res = fetch_to_dev_buffer(scp, arr, param_len);
-        if (-1 == res)
+	res = fetch_to_dev_buffer(scp, arr, param_len);
+	if (-1 == res)
 		return DID_ERROR << 16;
 	else if (sdebug_verbose && (res < param_len))
 		sdev_printk(KERN_INFO, scp->device,
@@ -2239,8 +2239,8 @@ static int resp_temp_l_pg(unsigned char * arr)
 				     0x0, 0x1, 0x3, 0x2, 0x0, 65,
 		};
 
-        memcpy(arr, temp_l_pg, sizeof(temp_l_pg));
-        return sizeof(temp_l_pg);
+	memcpy(arr, temp_l_pg, sizeof(temp_l_pg));
+	return sizeof(temp_l_pg);
 }
 
 static int resp_ie_l_pg(unsigned char * arr)
@@ -2248,18 +2248,18 @@ static int resp_ie_l_pg(unsigned char * arr)
 	unsigned char ie_l_pg[] = {0x0, 0x0, 0x3, 0x3, 0x0, 0x0, 38,
 		};
 
-        memcpy(arr, ie_l_pg, sizeof(ie_l_pg));
+	memcpy(arr, ie_l_pg, sizeof(ie_l_pg));
 	if (iec_m_pg[2] & 0x4) {	/* TEST bit set */
 		arr[4] = THRESHOLD_EXCEEDED;
 		arr[5] = 0xff;
 	}
-        return sizeof(ie_l_pg);
+	return sizeof(ie_l_pg);
 }
 
 #define SDEBUG_MAX_LSENSE_SZ 512
 
-static int resp_log_sense(struct scsi_cmnd * scp,
-                          struct sdebug_dev_info * devip)
+static int resp_log_sense(struct scsi_cmnd *scp,
+			  struct sdebug_dev_info *devip)
 {
 	int ppc, sp, pcode, subpcode, alloc_len, len, n;
 	unsigned char arr[SDEBUG_MAX_LSENSE_SZ];
@@ -3603,12 +3603,12 @@ static struct sdebug_dev_info *find_build_dev_info(struct scsi_device *sdev)
 	if (!sdbg_host) {
 		pr_err("Host info NULL\n");
 		return NULL;
-        }
+	}
 	list_for_each_entry(devip, &sdbg_host->dev_info_list, dev_list) {
 		if ((devip->used) && (devip->channel == sdev->channel) &&
-                    (devip->target == sdev->id) &&
-                    (devip->lun == sdev->lun))
-                        return devip;
+		    (devip->target == sdev->id) &&
+		    (devip->lun == sdev->lun))
+			return devip;
 		else {
 			if ((!devip->used) && (!open_devip))
 				open_devip = devip;
@@ -3848,8 +3848,8 @@ static int scsi_debug_bus_reset(struct scsi_cmnd * SCpnt)
 {
 	struct sdebug_host_info *sdbg_host;
 	struct sdebug_dev_info *devip;
-        struct scsi_device * sdp;
-        struct Scsi_Host * hp;
+	struct scsi_device *sdp;
+	struct Scsi_Host *hp;
 	int k = 0;
 
 	++num_bus_resets;
@@ -3863,7 +3863,7 @@ static int scsi_debug_bus_reset(struct scsi_cmnd * SCpnt)
 		sdbg_host = *(struct sdebug_host_info **)shost_priv(hp);
 		if (sdbg_host) {
 			list_for_each_entry(devip,
-                                            &sdbg_host->dev_info_list,
+					    &sdbg_host->dev_info_list,
 					    dev_list) {
 				set_bit(SDEBUG_UA_BUS_RESET, devip->uas_bm);
 				++k;
@@ -3886,15 +3886,15 @@ static int scsi_debug_host_reset(struct scsi_cmnd * SCpnt)
 	++num_host_resets;
 	if ((SCpnt->device) && (SDEBUG_OPT_ALL_NOISE & sdebug_opts))
 		sdev_printk(KERN_INFO, SCpnt->device, "%s\n", __func__);
-        spin_lock(&sdebug_host_list_lock);
-        list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {
+	spin_lock(&sdebug_host_list_lock);
+	list_for_each_entry(sdbg_host, &sdebug_host_list, host_list) {
 		list_for_each_entry(devip, &sdbg_host->dev_info_list,
 				    dev_list) {
 			set_bit(SDEBUG_UA_BUS_RESET, devip->uas_bm);
 			++k;
 		}
-        }
-        spin_unlock(&sdebug_host_list_lock);
+	}
+	spin_unlock(&sdebug_host_list_lock);
 	stop_all_queued();
 	if (SDEBUG_OPT_RESET_NOISE & sdebug_opts)
 		sdev_printk(KERN_INFO, SCpnt->device,
@@ -3921,7 +3921,7 @@ static void __init sdebug_build_parts(unsigned char *ramp,
 	sectors_per_part = (num_sectors - sdebug_sectors_per)
 			   / sdebug_num_parts;
 	heads_by_sects = sdebug_heads * sdebug_sectors_per;
-        starts[0] = sdebug_sectors_per;
+	starts[0] = sdebug_sectors_per;
 	for (k = 1; k < sdebug_num_parts; ++k)
 		starts[k] = ((k * sectors_per_part) / heads_by_sects)
 			    * heads_by_sects;
@@ -4426,15 +4426,15 @@ static ssize_t opts_show(struct device_driver *ddp, char *buf)
 static ssize_t opts_store(struct device_driver *ddp, const char *buf,
 			  size_t count)
 {
-        int opts;
+	int opts;
 	char work[20];
 
-        if (1 == sscanf(buf, "%10s", work)) {
-		if (0 == strncasecmp(work,"0x", 2)) {
-			if (1 == sscanf(&work[2], "%x", &opts))
+	if (sscanf(buf, "%10s", work) == 1) {
+		if (strncasecmp(work, "0x", 2) == 0) {
+			if (kstrtoint(work + 2, 16, &opts) == 0)
 				goto opts_done;
 		} else {
-			if (1 == sscanf(work, "%d", &opts))
+			if (kstrtoint(work, 10, &opts) == 0)
 				goto opts_done;
 		}
 	}
@@ -4455,7 +4455,7 @@ static ssize_t ptype_show(struct device_driver *ddp, char *buf)
 static ssize_t ptype_store(struct device_driver *ddp, const char *buf,
 			   size_t count)
 {
-        int n;
+	int n;
 
 	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
 		sdebug_ptype = n;
@@ -4472,7 +4472,7 @@ static ssize_t dsense_show(struct device_driver *ddp, char *buf)
 static ssize_t dsense_store(struct device_driver *ddp, const char *buf,
 			    size_t count)
 {
-        int n;
+	int n;
 
 	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
 		sdebug_dsense = n;
@@ -4489,7 +4489,7 @@ static ssize_t fake_rw_show(struct device_driver *ddp, char *buf)
 static ssize_t fake_rw_store(struct device_driver *ddp, const char *buf,
 			     size_t count)
 {
-        int n;
+	int n;
 
 	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
 		n = (n > 0);
@@ -4522,7 +4522,7 @@ static ssize_t no_lun_0_show(struct device_driver *ddp, char *buf)
 static ssize_t no_lun_0_store(struct device_driver *ddp, const char *buf,
 			      size_t count)
 {
-        int n;
+	int n;
 
 	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
 		sdebug_no_lun_0 = n;
@@ -4539,7 +4539,7 @@ static ssize_t num_tgts_show(struct device_driver *ddp, char *buf)
 static ssize_t num_tgts_store(struct device_driver *ddp, const char *buf,
 			      size_t count)
 {
-        int n;
+	int n;
 
 	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
 		sdebug_num_tgts = n;
@@ -4569,7 +4569,7 @@ static ssize_t every_nth_show(struct device_driver *ddp, char *buf)
 static ssize_t every_nth_store(struct device_driver *ddp, const char *buf,
 			       size_t count)
 {
-        int nth;
+	int nth;
 
 	if ((count > 0) && (1 == sscanf(buf, "%d", &nth))) {
 		sdebug_every_nth = nth;
@@ -4591,7 +4591,7 @@ static ssize_t max_luns_show(struct device_driver *ddp, char *buf)
 static ssize_t max_luns_store(struct device_driver *ddp, const char *buf,
 			      size_t count)
 {
-        int n;
+	int n;
 	bool changed;
 
 	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
@@ -4678,7 +4678,7 @@ static ssize_t virtual_gb_show(struct device_driver *ddp, char *buf)
 static ssize_t virtual_gb_store(struct device_driver *ddp, const char *buf,
 				size_t count)
 {
-        int n;
+	int n;
 	bool changed;
 
 	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
@@ -5113,12 +5113,12 @@ static int __init scsi_debug_init(void)
 	host_to_add = sdebug_add_host;
 	sdebug_add_host = 0;
 
-        for (k = 0; k < host_to_add; k++) {
-                if (sdebug_add_adapter()) {
+	for (k = 0; k < host_to_add; k++) {
+		if (sdebug_add_adapter()) {
 			pr_err("sdebug_add_adapter failed k=%d\n", k);
-                        break;
-                }
-        }
+			break;
+		}
+	}
 
 	if (sdebug_verbose)
 		pr_info("built %d host(s)\n", sdebug_add_host);
@@ -5161,53 +5161,53 @@ module_exit(scsi_debug_exit);
 
 static void sdebug_release_adapter(struct device * dev)
 {
-        struct sdebug_host_info *sdbg_host;
+	struct sdebug_host_info *sdbg_host;
 
 	sdbg_host = to_sdebug_host(dev);
-        kfree(sdbg_host);
+	kfree(sdbg_host);
 }
 
 static int sdebug_add_adapter(void)
 {
 	int k, devs_per_host;
-        int error = 0;
-        struct sdebug_host_info *sdbg_host;
+	int error = 0;
+	struct sdebug_host_info *sdbg_host;
 	struct sdebug_dev_info *sdbg_devinfo, *tmp;
 
-        sdbg_host = kzalloc(sizeof(*sdbg_host),GFP_KERNEL);
-        if (NULL == sdbg_host) {
+	sdbg_host = kzalloc(sizeof(*sdbg_host), GFP_KERNEL);
+	if (sdbg_host == NULL) {
 		pr_err("out of memory at line %d\n", __LINE__);
-                return -ENOMEM;
-        }
+		return -ENOMEM;
+	}
 
-        INIT_LIST_HEAD(&sdbg_host->dev_info_list);
+	INIT_LIST_HEAD(&sdbg_host->dev_info_list);
 
 	devs_per_host = sdebug_num_tgts * sdebug_max_luns;
-        for (k = 0; k < devs_per_host; k++) {
+	for (k = 0; k < devs_per_host; k++) {
 		sdbg_devinfo = sdebug_device_create(sdbg_host, GFP_KERNEL);
 		if (!sdbg_devinfo) {
 			pr_err("out of memory at line %d\n", __LINE__);
-                        error = -ENOMEM;
+			error = -ENOMEM;
 			goto clean;
-                }
-        }
+		}
+	}
 
-        spin_lock(&sdebug_host_list_lock);
-        list_add_tail(&sdbg_host->host_list, &sdebug_host_list);
-        spin_unlock(&sdebug_host_list_lock);
+	spin_lock(&sdebug_host_list_lock);
+	list_add_tail(&sdbg_host->host_list, &sdebug_host_list);
+	spin_unlock(&sdebug_host_list_lock);
 
-        sdbg_host->dev.bus = &pseudo_lld_bus;
-        sdbg_host->dev.parent = pseudo_primary;
-        sdbg_host->dev.release = &sdebug_release_adapter;
+	sdbg_host->dev.bus = &pseudo_lld_bus;
+	sdbg_host->dev.parent = pseudo_primary;
+	sdbg_host->dev.release = &sdebug_release_adapter;
 	dev_set_name(&sdbg_host->dev, "adapter%d", sdebug_add_host);
 
-        error = device_register(&sdbg_host->dev);
+	error = device_register(&sdbg_host->dev);
 
-        if (error)
+	if (error)
 		goto clean;
 
 	++sdebug_add_host;
-        return error;
+	return error;
 
 clean:
 	list_for_each_entry_safe(sdbg_devinfo, tmp, &sdbg_host->dev_info_list,
@@ -5217,20 +5217,20 @@ static int sdebug_add_adapter(void)
 	}
 
 	kfree(sdbg_host);
-        return error;
+	return error;
 }
 
 static void sdebug_remove_adapter(void)
 {
-        struct sdebug_host_info * sdbg_host = NULL;
+	struct sdebug_host_info *sdbg_host = NULL;
 
-        spin_lock(&sdebug_host_list_lock);
-        if (!list_empty(&sdebug_host_list)) {
-                sdbg_host = list_entry(sdebug_host_list.prev,
-                                       struct sdebug_host_info, host_list);
+	spin_lock(&sdebug_host_list_lock);
+	if (!list_empty(&sdebug_host_list)) {
+		sdbg_host = list_entry(sdebug_host_list.prev,
+				       struct sdebug_host_info, host_list);
 		list_del(&sdbg_host->host_list);
 	}
-        spin_unlock(&sdebug_host_list_lock);
+	spin_unlock(&sdebug_host_list_lock);
 
 	if (!sdbg_host)
 		return;
@@ -5484,7 +5484,7 @@ static int sdebug_driver_probe(struct device * dev)
 	if (sdebug_mq_active)
 		hpnt->nr_hw_queues = submit_queues;
 
-        sdbg_host->shost = hpnt;
+	sdbg_host->shost = hpnt;
 	*((struct sdebug_host_info **)hpnt->hostdata) = sdbg_host;
 	if ((hpnt->this_id >= 0) && (sdebug_num_tgts > hpnt->this_id))
 		hpnt->max_id = sdebug_num_tgts + 1;
@@ -5542,12 +5542,12 @@ static int sdebug_driver_probe(struct device * dev)
 	sdebug_any_injecting_opt = !!(SDEBUG_OPT_ALL_INJECTING & sdebug_opts);
 	if (sdebug_every_nth)	/* need stats counters for every_nth */
 		sdebug_statistics = true;
-        error = scsi_add_host(hpnt, &sdbg_host->dev);
-        if (error) {
+	error = scsi_add_host(hpnt, &sdbg_host->dev);
+	if (error) {
 		pr_err("scsi_add_host failed\n");
-                error = -ENODEV;
+		error = -ENODEV;
 		scsi_host_put(hpnt);
-        } else
+	} else
 		scsi_scan_host(hpnt);
 
 	return error;
@@ -5555,7 +5555,7 @@ static int sdebug_driver_probe(struct device * dev)
 
 static int sdebug_driver_remove(struct device * dev)
 {
-        struct sdebug_host_info *sdbg_host;
+	struct sdebug_host_info *sdbg_host;
 	struct sdebug_dev_info *sdbg_devinfo, *tmp;
 
 	sdbg_host = to_sdebug_host(dev);
@@ -5565,16 +5565,16 @@ static int sdebug_driver_remove(struct device * dev)
 		return -ENODEV;
 	}
 
-        scsi_remove_host(sdbg_host->shost);
+	scsi_remove_host(sdbg_host->shost);
 
 	list_for_each_entry_safe(sdbg_devinfo, tmp, &sdbg_host->dev_info_list,
 				 dev_list) {
-                list_del(&sdbg_devinfo->dev_list);
-                kfree(sdbg_devinfo);
-        }
+		list_del(&sdbg_devinfo->dev_list);
+		kfree(sdbg_devinfo);
+	}
 
-        scsi_host_put(sdbg_host->shost);
-        return 0;
+	scsi_host_put(sdbg_host->shost);
+	return 0;
 }
 
 static int pseudo_lld_bus_match(struct device *dev,
-- 
2.14.1

[PATCH v3 2/5] scsi_debug: fix group_number mask

[Douglas Gilbert]

Various cdb masks incorrectly assumed the GROUP NUMBER field
was 5 bits long. It is actually 6 bits long. Correct.
Also fix mask failure (in same byte) to allow DLD0 in READ(16)
and WRITE(16).

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
---
 drivers/scsi/scsi_debug.c | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 80a775b6e648..428165dbd486 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -421,23 +421,23 @@ static const struct opcode_info_t mselect_iarr[1] = {
 
 static const struct opcode_info_t read_iarr[3] = {
 	{0, 0x28, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, NULL,/* READ(10) */
-	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x1f, 0xff, 0xff, 0xc7, 0, 0,
+	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0, 0,
 	     0, 0, 0, 0} },
 	{0, 0x8, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, NULL, /* READ(6) */
 	    {6,  0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 	{0, 0xa8, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, NULL,/* READ(12) */
-	    {12,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x9f,
+	    {12,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xbf,
 	     0xc7, 0, 0, 0, 0} },
 };
 
 static const struct opcode_info_t write_iarr[3] = {
 	{0, 0x2a, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, NULL,   /* 10 */
-	    {10,  0xfb, 0xff, 0xff, 0xff, 0xff, 0x1f, 0xff, 0xff, 0xc7, 0, 0,
+	    {10,  0xfb, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0, 0,
 	     0, 0, 0, 0} },
 	{0, 0xa, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, NULL,    /* 6 */
 	    {6,  0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 	{0, 0xaa, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, NULL,   /* 12 */
-	    {12,  0xfb, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x9f,
+	    {12,  0xfb, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xbf,
 	     0xc7, 0, 0, 0, 0} },
 };
 
@@ -449,7 +449,7 @@ static const struct opcode_info_t sa_in_iarr[1] = {
 
 static const struct opcode_info_t vl_iarr[1] = {	/* VARIABLE LENGTH */
 	{0, 0x7f, 0xb, F_SA_HIGH | F_D_OUT | FF_DIRECT_IO, resp_write_dt0,
-	    NULL, {32,  0xc7, 0, 0, 0, 0, 0x1f, 0x18, 0x0, 0xb, 0xfa,
+	    NULL, {32,  0xc7, 0, 0, 0, 0, 0x3f, 0x18, 0x0, 0xb, 0xfa,
 		   0, 0xff, 0xff, 0xff, 0xff} },	/* WRITE(32) */
 };
 
@@ -465,7 +465,7 @@ static const struct opcode_info_t maint_in_iarr[2] = {
 static const struct opcode_info_t write_same_iarr[1] = {
 	{0, 0x93, 0, F_D_OUT_MAYBE | FF_DIRECT_IO, resp_write_same_16, NULL,
 	    {16,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-	     0xff, 0xff, 0xff, 0x1f, 0xc7} },
+	     0xff, 0xff, 0xff, 0x3f, 0xc7} },
 };
 
 static const struct opcode_info_t reserve_iarr[1] = {
@@ -508,11 +508,11 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
 	     0, 0} },
 	{3, 0x88, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, read_iarr,
 	    {16,  0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-	     0xff, 0xff, 0xff, 0x9f, 0xc7} },		/* READ(16) */
+	     0xff, 0xff, 0xff, 0xff, 0xc7} },		/* READ(16) */
 /* 10 */
 	{3, 0x8a, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, write_iarr,
 	    {16,  0xfa, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-	     0xff, 0xff, 0xff, 0x9f, 0xc7} },		/* WRITE(16) */
+	     0xff, 0xff, 0xff, 0xff, 0xc7} },		/* WRITE(16) */
 	{0, 0x1b, 0, 0, resp_start_stop, NULL,		/* START STOP UNIT */
 	    {6,  0x1, 0, 0xf, 0xf7, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 	{1, 0x9e, 0x10, F_SA_LOW | F_D_IN, resp_readcap16, sa_in_iarr,
@@ -529,7 +529,7 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
 	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7,
 	     0, 0, 0, 0, 0, 0} },
 	{1, 0x7f, 0x9, F_SA_HIGH | F_D_IN | FF_DIRECT_IO, resp_read_dt0,
-	    vl_iarr, {32,  0xc7, 0, 0, 0, 0, 0x1f, 0x18, 0x0, 0x9, 0xfe, 0,
+	    vl_iarr, {32,  0xc7, 0, 0, 0, 0, 0x3f, 0x18, 0x0, 0x9, 0xfe, 0,
 		      0xff, 0xff, 0xff, 0xff} },/* VARIABLE LENGTH, READ(32) */
 	{1, 0x56, 0, F_D_OUT, NULL, reserve_iarr, /* RESERVE(10) */
 	    {10,  0xff, 0xff, 0xff, 0, 0, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0,
@@ -547,22 +547,22 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
 	{0, 0x1d, F_D_OUT, 0, NULL, NULL,	/* SEND DIAGNOSTIC */
 	    {6,  0xf7, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 	{0, 0x42, 0, F_D_OUT | FF_DIRECT_IO, resp_unmap, NULL, /* UNMAP */
-	    {10,  0x1, 0, 0, 0, 0, 0x1f, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
+	    {10,  0x1, 0, 0, 0, 0, 0x3f, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
 	{0, 0x53, 0, F_D_IN | F_D_OUT | FF_DIRECT_IO, resp_xdwriteread_10,
-	    NULL, {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x1f, 0xff, 0xff, 0xc7,
+	    NULL, {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7,
 		   0, 0, 0, 0, 0, 0} },
 	{0, 0x3b, 0, F_D_OUT_MAYBE, resp_write_buffer, NULL,
 	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0,
 	     0, 0, 0, 0} },			/* WRITE_BUFFER */
 	{1, 0x41, 0, F_D_OUT_MAYBE | FF_DIRECT_IO, resp_write_same_10,
-	    write_same_iarr, {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x1f, 0xff,
+	    write_same_iarr, {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff,
 			      0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
 	{0, 0x35, 0, F_DELAY_OVERR | FF_DIRECT_IO, NULL, NULL, /* SYNC_CACHE */
-	    {10,  0x7, 0xff, 0xff, 0xff, 0xff, 0x1f, 0xff, 0xff, 0xc7, 0, 0,
+	    {10,  0x7, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0, 0,
 	     0, 0, 0, 0} },
 	{0, 0x89, 0, F_D_OUT | FF_DIRECT_IO, resp_comp_write, NULL,
 	    {16,  0xf8, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0,
-	     0, 0xff, 0x1f, 0xc7} },		/* COMPARE AND WRITE */
+	     0, 0xff, 0x3f, 0xc7} },		/* COMPARE AND WRITE */
 
 /* 30 */
 	{0xff, 0, 0, 0, NULL, NULL,		/* terminating element */
-- 
2.14.1

[PATCH v3 3/5] scsi_debug: do_device_access add sg offset argument

[Douglas Gilbert]

WRITE SCATTERED needs to take several "bites" out of the data-out buffer.
Expand the do_device_access() function to take a sg_skip argument.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
---
 drivers/scsi/scsi_debug.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 428165dbd486..4cd703f0aac0 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -2353,8 +2353,8 @@ static int check_device_access_params(struct scsi_cmnd *scp,
 }
 
 /* Returns number of bytes copied or -1 if error. */
-static int do_device_access(struct scsi_cmnd *scmd, u64 lba, u32 num,
-			    bool do_write)
+static int do_device_access(struct scsi_cmnd *scmd, u32 sg_skip, u64 lba,
+			    u32 num, bool do_write)
 {
 	int ret;
 	u64 block, rest = 0;
@@ -2380,14 +2380,15 @@ static int do_device_access(struct scsi_cmnd *scmd, u64 lba, u32 num,
 
 	ret = sg_copy_buffer(sdb->table.sgl, sdb->table.nents,
 		   fake_storep + (block * sdebug_sector_size),
-		   (num - rest) * sdebug_sector_size, 0, do_write);
+		   (num - rest) * sdebug_sector_size, sg_skip, do_write);
 	if (ret != (num - rest) * sdebug_sector_size)
 		return ret;
 
 	if (rest) {
 		ret += sg_copy_buffer(sdb->table.sgl, sdb->table.nents,
 			    fake_storep, rest * sdebug_sector_size,
-			    (num - rest) * sdebug_sector_size, do_write);
+			    sg_skip + ((num - rest) * sdebug_sector_size),
+			    do_write);
 	}
 
 	return ret;
@@ -2648,7 +2649,7 @@ static int resp_read_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 		}
 	}
 
-	ret = do_device_access(scp, lba, num, false);
+	ret = do_device_access(scp, 0, lba, num, false);
 	read_unlock_irqrestore(&atomic_rw, iflags);
 	if (unlikely(ret == -1))
 		return DID_ERROR << 16;
@@ -2936,7 +2937,7 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 		}
 	}
 
-	ret = do_device_access(scp, lba, num, true);
+	ret = do_device_access(scp, 0, lba, num, true);
 	if (unlikely(scsi_debug_lbp()))
 		map_region(lba, num);
 	write_unlock_irqrestore(&atomic_rw, iflags);
@@ -3177,7 +3178,7 @@ static int resp_comp_write(struct scsi_cmnd *scp,
 	 * from data-in into arr. Safe (atomic) since write_lock held. */
 	fake_storep_hold = fake_storep;
 	fake_storep = arr;
-	ret = do_device_access(scp, 0, dnum, true);
+	ret = do_device_access(scp, 0, 0, dnum, true);
 	fake_storep = fake_storep_hold;
 	if (ret == -1) {
 		retval = DID_ERROR << 16;
-- 
2.14.1

[PATCH v3 4/5] scsi_debug: ARRAY_SIZE and FF_MEDIA_IO

[Douglas Gilbert]

Reviewer suggested using the ARRAY_SIZE macro. That reduced one of the subtle
inter-dependencies in the parser's tables.

It is important that commands which simulate media access, indicate this in the
flags for that command. The flag to do that was FF_DIRECT_IO. On reflection
FF_MEDIA_IO seems a more accurate description.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
Reviewed-by: Bart Van Assche <bart.vanassche@wdc.com>
---
 drivers/scsi/scsi_debug.c | 163 +++++++++++++++++++++++++---------------------
 1 file changed, 90 insertions(+), 73 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 4cd703f0aac0..3c56675c9b0c 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -232,7 +232,7 @@ static const char *sdebug_version_date = "20160430";
 #define F_M_ACCESS		0x800	/* media access */
 
 #define FF_RESPOND (F_RL_WLUN_OK | F_SKIP_UA | F_DELAY_OVERR)
-#define FF_DIRECT_IO (F_M_ACCESS | F_FAKE_RW)
+#define FF_MEDIA_IO (F_M_ACCESS | F_FAKE_RW)
 #define FF_SA (F_SA_HIGH | F_SA_LOW)
 
 #define SDEBUG_MAX_PARTS 4
@@ -322,12 +322,12 @@ enum sdeb_opcode_index {
 	SDEB_I_READ = 9,		/* 6, 10, 12, 16 */
 	SDEB_I_WRITE = 10,		/* 6, 10, 12, 16 */
 	SDEB_I_START_STOP = 11,
-	SDEB_I_SERV_ACT_IN = 12,	/* 12, 16 */
-	SDEB_I_SERV_ACT_OUT = 13,	/* 12, 16 */
+	SDEB_I_SERV_ACT_IN_16 = 12,	/* add ...SERV_ACT_IN_12 if needed */
+	SDEB_I_SERV_ACT_OUT_16 = 13,	/* add ...SERV_ACT_OUT_12 if needed */
 	SDEB_I_MAINT_IN = 14,
 	SDEB_I_MAINT_OUT = 15,
 	SDEB_I_VERIFY = 16,		/* 10 only */
-	SDEB_I_VARIABLE_LEN = 17,
+	SDEB_I_VARIABLE_LEN = 17,	/* READ(32), WRITE(32) */
 	SDEB_I_RESERVE = 18,		/* 6, 10 */
 	SDEB_I_RELEASE = 19,		/* 6, 10 */
 	SDEB_I_ALLOW_REMOVAL = 20,	/* PREVENT ALLOW MEDIUM REMOVAL */
@@ -372,12 +372,12 @@ static const unsigned char opcode_ind_arr[256] = {
 	0, 0, 0, 0, 0, SDEB_I_ATA_PT, 0, 0,
 	SDEB_I_READ, SDEB_I_COMP_WRITE, SDEB_I_WRITE, 0, 0, 0, 0, 0,
 	0, 0, 0, SDEB_I_WRITE_SAME, 0, 0, 0, 0,
-	0, 0, 0, 0, 0, 0, SDEB_I_SERV_ACT_IN, SDEB_I_SERV_ACT_OUT,
+	0, 0, 0, 0, 0, 0, SDEB_I_SERV_ACT_IN_16, SDEB_I_SERV_ACT_OUT_16,
 /* 0xa0; 0xa0->0xbf: 12 byte cdbs */
 	SDEB_I_REPORT_LUNS, SDEB_I_ATA_PT, 0, SDEB_I_MAINT_IN,
 	     SDEB_I_MAINT_OUT, 0, 0, 0,
-	SDEB_I_READ, SDEB_I_SERV_ACT_OUT, SDEB_I_WRITE, SDEB_I_SERV_ACT_IN,
-	     0, 0, 0, 0,
+	SDEB_I_READ, 0 /* SDEB_I_SERV_ACT_OUT_12 */, SDEB_I_WRITE,
+	     0 /* SDEB_I_SERV_ACT_IN_12 */, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, 0, 0, 0,
 	0, 0, 0, 0, 0, 0, 0, 0,
 /* 0xc0; 0xc0->0xff: vendor specific */
@@ -409,72 +409,78 @@ static int resp_xdwriteread_10(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_comp_write(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_write_buffer(struct scsi_cmnd *, struct sdebug_dev_info *);
 
-static const struct opcode_info_t msense_iarr[1] = {
+/*
+ * The following are overflow arrays for cdbs that "hit" the same index in
+ * the opcode_info_arr array. The most time sensitive (or commonly used) cdb
+ * should be placed in opcode_info_arr[], the others should be placed here.
+ */
+static const struct opcode_info_t msense_iarr[] = {
 	{0, 0x1a, 0, F_D_IN, NULL, NULL,
 	    {6,  0xe8, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 };
 
-static const struct opcode_info_t mselect_iarr[1] = {
+static const struct opcode_info_t mselect_iarr[] = {
 	{0, 0x15, 0, F_D_OUT, NULL, NULL,
 	    {6,  0xf1, 0, 0, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 };
 
-static const struct opcode_info_t read_iarr[3] = {
-	{0, 0x28, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, NULL,/* READ(10) */
+static const struct opcode_info_t read_iarr[] = {
+	{0, 0x28, 0, F_D_IN | FF_MEDIA_IO, resp_read_dt0, NULL,/* READ(10) */
 	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0, 0,
 	     0, 0, 0, 0} },
-	{0, 0x8, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, NULL, /* READ(6) */
+	{0, 0x8, 0, F_D_IN | FF_MEDIA_IO, resp_read_dt0, NULL, /* READ(6) */
 	    {6,  0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
-	{0, 0xa8, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, NULL,/* READ(12) */
+	{0, 0xa8, 0, F_D_IN | FF_MEDIA_IO, resp_read_dt0, NULL,/* READ(12) */
 	    {12,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xbf,
 	     0xc7, 0, 0, 0, 0} },
 };
 
-static const struct opcode_info_t write_iarr[3] = {
-	{0, 0x2a, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, NULL,   /* 10 */
-	    {10,  0xfb, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0, 0,
-	     0, 0, 0, 0} },
-	{0, 0xa, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, NULL,    /* 6 */
-	    {6,  0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
-	{0, 0xaa, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, NULL,   /* 12 */
-	    {12,  0xfb, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xbf,
-	     0xc7, 0, 0, 0, 0} },
+static const struct opcode_info_t write_iarr[] = {
+	{0, 0x2a, 0, F_D_OUT | FF_MEDIA_IO, resp_write_dt0,  /* WRITE(10) */
+	    NULL, {10,  0xfb, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7,
+		   0, 0, 0, 0, 0, 0} },
+	{0, 0xa, 0, F_D_OUT | FF_MEDIA_IO, resp_write_dt0,   /* WRITE(6) */
+	    NULL, {6,  0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0,
+		   0, 0, 0} },
+	{0, 0xaa, 0, F_D_OUT | FF_MEDIA_IO, resp_write_dt0,  /* WRITE(12) */
+	    NULL, {12,  0xfb, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+		   0xbf, 0xc7, 0, 0, 0, 0} },
 };
 
-static const struct opcode_info_t sa_in_iarr[1] = {
+static const struct opcode_info_t sa_in_16_iarr[] = {
 	{0, 0x9e, 0x12, F_SA_LOW | F_D_IN, resp_get_lba_status, NULL,
 	    {16,  0x12, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-	     0xff, 0xff, 0xff, 0, 0xc7} },
+	     0xff, 0xff, 0xff, 0, 0xc7} },	/* GET LBA STATUS(16) */
 };
 
-static const struct opcode_info_t vl_iarr[1] = {	/* VARIABLE LENGTH */
-	{0, 0x7f, 0xb, F_SA_HIGH | F_D_OUT | FF_DIRECT_IO, resp_write_dt0,
+static const struct opcode_info_t vl_iarr[] = {	/* VARIABLE LENGTH */
+	{0, 0x7f, 0xb, F_SA_HIGH | F_D_OUT | FF_MEDIA_IO, resp_write_dt0,
 	    NULL, {32,  0xc7, 0, 0, 0, 0, 0x3f, 0x18, 0x0, 0xb, 0xfa,
 		   0, 0xff, 0xff, 0xff, 0xff} },	/* WRITE(32) */
 };
 
-static const struct opcode_info_t maint_in_iarr[2] = {
+static const struct opcode_info_t maint_in_iarr[] = {	/* MAINT IN */
 	{0, 0xa3, 0xc, F_SA_LOW | F_D_IN, resp_rsup_opcodes, NULL,
 	    {12,  0xc, 0x87, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0,
-	     0xc7, 0, 0, 0, 0} },
+	     0xc7, 0, 0, 0, 0} }, /* REPORT SUPPORTED OPERATION CODES */
 	{0, 0xa3, 0xd, F_SA_LOW | F_D_IN, resp_rsup_tmfs, NULL,
 	    {12,  0xd, 0x80, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0, 0xc7, 0, 0,
-	     0, 0} },
+	     0, 0} },	/* REPORTED SUPPORTED TASK MANAGEMENT FUNCTIONS */
 };
 
-static const struct opcode_info_t write_same_iarr[1] = {
-	{0, 0x93, 0, F_D_OUT_MAYBE | FF_DIRECT_IO, resp_write_same_16, NULL,
+static const struct opcode_info_t write_same_iarr[] = {
+	{0, 0x93, 0, F_D_OUT_MAYBE | FF_MEDIA_IO, resp_write_same_16, NULL,
 	    {16,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-	     0xff, 0xff, 0xff, 0x3f, 0xc7} },
+	     0xff, 0xff, 0xff, 0x3f, 0xc7} },		/* WRITE SAME(16) */
 };
 
-static const struct opcode_info_t reserve_iarr[1] = {
-	{0, 0x16, 0, F_D_OUT, NULL, NULL,	/* RESERVE(6) */
+static const struct opcode_info_t reserve_iarr[] = {
+	{0, 0x16, 0, F_D_OUT, NULL, NULL,		/* RESERVE(6) */
 	    {6,  0x1f, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 };
 
-static const struct opcode_info_t release_iarr[1] = {
-	{0, 0x17, 0, F_D_OUT, NULL, NULL,	/* RELEASE(6) */
+static const struct opcode_info_t release_iarr[] = {
+	{0, 0x17, 0, F_D_OUT, NULL, NULL,		/* RELEASE(6) */
 	    {6,  0x1f, 0xff, 0, 0, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 };
 
@@ -484,57 +490,66 @@ static const struct opcode_info_t release_iarr[1] = {
  * REPORT SUPPORTED OPERATION CODES. */
 static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
 /* 0 */
-	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL,
+	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL,	/* unknown opcodes */
 	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
-	{0, 0x12, 0, FF_RESPOND | F_D_IN, resp_inquiry, NULL,
+	{0, 0x12, 0, FF_RESPOND | F_D_IN, resp_inquiry, NULL, /* INQUIRY */
 	    {6,  0xe3, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 	{0, 0xa0, 0, FF_RESPOND | F_D_IN, resp_report_luns, NULL,
 	    {12,  0xe3, 0xff, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0, 0xc7, 0, 0,
-	     0, 0} },
+	     0, 0} },					/* REPORT LUNS */
 	{0, 0x3, 0, FF_RESPOND | F_D_IN, resp_requests, NULL,
 	    {6,  0xe1, 0, 0, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 	{0, 0x0, 0, F_M_ACCESS | F_RL_WLUN_OK, NULL, NULL,/* TEST UNIT READY */
 	    {6,  0, 0, 0, 0, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
-	{1, 0x5a, 0, F_D_IN, resp_mode_sense, msense_iarr,
-	    {10,  0xf8, 0xff, 0xff, 0, 0, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0,
-	     0} },
-	{1, 0x55, 0, F_D_OUT, resp_mode_select, mselect_iarr,
-	    {10,  0xf1, 0, 0, 0, 0, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
-	{0, 0x4d, 0, F_D_IN, resp_log_sense, NULL,
+/* 5 */
+	{ARRAY_SIZE(msense_iarr), 0x5a, 0, F_D_IN,	/* MODE SENSE(10) */
+	    resp_mode_sense, msense_iarr, {10,  0xf8, 0xff, 0xff, 0, 0, 0,
+		0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
+	{ARRAY_SIZE(mselect_iarr), 0x55, 0, F_D_OUT,	/* MODE SELECT(10) */
+	    resp_mode_select, mselect_iarr, {10,  0xf1, 0, 0, 0, 0, 0, 0xff,
+		0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
+	{0, 0x4d, 0, F_D_IN, resp_log_sense, NULL,	/* LOG SENSE */
 	    {10,  0xe3, 0xff, 0xff, 0, 0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0, 0,
 	     0, 0, 0} },
-	{0, 0x25, 0, F_D_IN, resp_readcap, NULL,
+	{0, 0x25, 0, F_D_IN, resp_readcap, NULL,    /* READ CAPACITY(10) */
 	    {10,  0xe1, 0xff, 0xff, 0xff, 0xff, 0, 0, 0x1, 0xc7, 0, 0, 0, 0,
 	     0, 0} },
-	{3, 0x88, 0, F_D_IN | FF_DIRECT_IO, resp_read_dt0, read_iarr,
-	    {16,  0xfe, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-	     0xff, 0xff, 0xff, 0xff, 0xc7} },		/* READ(16) */
+	{ARRAY_SIZE(read_iarr), 0x88, 0, F_D_IN | FF_MEDIA_IO, /* READ(16) */
+	    resp_read_dt0, read_iarr, {16,  0xfe, 0xff, 0xff, 0xff, 0xff,
+	    0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7} },
 /* 10 */
-	{3, 0x8a, 0, F_D_OUT | FF_DIRECT_IO, resp_write_dt0, write_iarr,
-	    {16,  0xfa, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-	     0xff, 0xff, 0xff, 0xff, 0xc7} },		/* WRITE(16) */
+	{ARRAY_SIZE(write_iarr), 0x8a, 0, F_D_OUT | FF_MEDIA_IO,
+	    resp_write_dt0, write_iarr,			/* WRITE(16) */
+		{16,  0xfa, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+		 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7} },		/* WRITE(16) */
 	{0, 0x1b, 0, 0, resp_start_stop, NULL,		/* START STOP UNIT */
 	    {6,  0x1, 0, 0xf, 0xf7, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
-	{1, 0x9e, 0x10, F_SA_LOW | F_D_IN, resp_readcap16, sa_in_iarr,
-	    {16,  0x10, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
-	     0xff, 0xff, 0xff, 0x1, 0xc7} },	/* READ CAPACITY(16) */
-	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL, /* SA OUT */
+	{ARRAY_SIZE(sa_in_16_iarr), 0x9e, 0x10, F_SA_LOW | F_D_IN,
+	    resp_readcap16, sa_in_16_iarr, /* SA_IN(16), READ CAPACITY(16) */
+		{16,  0x10, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+		 0xff, 0xff, 0xff, 0xff, 0x1, 0xc7} },
+	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL, /* SA_OUT(16) */
 	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
-	{2, 0xa3, 0xa, F_SA_LOW | F_D_IN, resp_report_tgtpgs, maint_in_iarr,
-	    {12,  0xea, 0, 0, 0, 0, 0xff, 0xff, 0xff, 0xff, 0, 0xc7, 0, 0, 0,
-	     0} },
+	{ARRAY_SIZE(maint_in_iarr), 0xa3, 0xa, F_SA_LOW | F_D_IN,
+	    resp_report_tgtpgs,	/* MAINT IN, REPORT TARGET PORT GROUPS */
+		maint_in_iarr, {12,  0xea, 0, 0, 0, 0, 0xff, 0xff, 0xff,
+				0xff, 0, 0xc7, 0, 0, 0, 0} },
+/* 15 */
 	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL, /* MAINT OUT */
 	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
-	{0, 0x2f, 0, F_D_OUT_MAYBE | FF_DIRECT_IO, NULL, NULL, /* VERIFY(10) */
+	{0, 0x2f, 0, F_D_OUT_MAYBE | FF_MEDIA_IO, NULL, NULL, /* VERIFY(10) */
 	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7,
 	     0, 0, 0, 0, 0, 0} },
-	{1, 0x7f, 0x9, F_SA_HIGH | F_D_IN | FF_DIRECT_IO, resp_read_dt0,
-	    vl_iarr, {32,  0xc7, 0, 0, 0, 0, 0x3f, 0x18, 0x0, 0x9, 0xfe, 0,
-		      0xff, 0xff, 0xff, 0xff} },/* VARIABLE LENGTH, READ(32) */
-	{1, 0x56, 0, F_D_OUT, NULL, reserve_iarr, /* RESERVE(10) */
+	{ARRAY_SIZE(vl_iarr), 0x7f, 0x9, F_SA_HIGH | F_D_IN | FF_MEDIA_IO,
+	    resp_read_dt0, vl_iarr,	/* VARIABLE LENGTH, READ(32) */
+	    {32,  0xc7, 0, 0, 0, 0, 0x3f, 0x18, 0x0, 0x9, 0xfe, 0, 0xff, 0xff,
+	     0xff, 0xff} },
+	{ARRAY_SIZE(reserve_iarr), 0x56, 0, F_D_OUT,
+	    NULL, reserve_iarr,	/* RESERVE(10) <no response function> */
 	    {10,  0xff, 0xff, 0xff, 0, 0, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0,
 	     0} },
-	{1, 0x57, 0, F_D_OUT, NULL, release_iarr, /* RELEASE(10) */
+	{ARRAY_SIZE(release_iarr), 0x57, 0, F_D_OUT,
+	    NULL, release_iarr, /* RELEASE(10) <no response function> */
 	    {10,  0x13, 0xff, 0xff, 0, 0, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0,
 	     0} },
 /* 20 */
@@ -546,21 +561,23 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
 	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
 	{0, 0x1d, F_D_OUT, 0, NULL, NULL,	/* SEND DIAGNOSTIC */
 	    {6,  0xf7, 0, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
-	{0, 0x42, 0, F_D_OUT | FF_DIRECT_IO, resp_unmap, NULL, /* UNMAP */
+	{0, 0x42, 0, F_D_OUT | FF_MEDIA_IO, resp_unmap, NULL, /* UNMAP */
 	    {10,  0x1, 0, 0, 0, 0, 0x3f, 0xff, 0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
-	{0, 0x53, 0, F_D_IN | F_D_OUT | FF_DIRECT_IO, resp_xdwriteread_10,
+/* 25 */
+	{0, 0x53, 0, F_D_IN | F_D_OUT | FF_MEDIA_IO, resp_xdwriteread_10,
 	    NULL, {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7,
-		   0, 0, 0, 0, 0, 0} },
+		   0, 0, 0, 0, 0, 0} },		/* XDWRITEREAD(10) */
 	{0, 0x3b, 0, F_D_OUT_MAYBE, resp_write_buffer, NULL,
 	    {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc7, 0, 0,
 	     0, 0, 0, 0} },			/* WRITE_BUFFER */
-	{1, 0x41, 0, F_D_OUT_MAYBE | FF_DIRECT_IO, resp_write_same_10,
-	    write_same_iarr, {10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff,
-			      0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
-	{0, 0x35, 0, F_DELAY_OVERR | FF_DIRECT_IO, NULL, NULL, /* SYNC_CACHE */
+	{ARRAY_SIZE(write_same_iarr), 0x41, 0, F_D_OUT_MAYBE | FF_MEDIA_IO,
+	    resp_write_same_10, write_same_iarr,	/* WRITE SAME(10) */
+		{10,  0xff, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0,
+		 0, 0, 0, 0, 0} },
+	{0, 0x35, 0, F_DELAY_OVERR | FF_MEDIA_IO, NULL, NULL, /* SYNC_CACHE */
 	    {10,  0x7, 0xff, 0xff, 0xff, 0xff, 0x3f, 0xff, 0xff, 0xc7, 0, 0,
 	     0, 0, 0, 0} },
-	{0, 0x89, 0, F_D_OUT | FF_DIRECT_IO, resp_comp_write, NULL,
+	{0, 0x89, 0, F_D_OUT | FF_MEDIA_IO, resp_comp_write, NULL,
 	    {16,  0xf8, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0, 0,
 	     0, 0xff, 0x3f, 0xc7} },		/* COMPARE AND WRITE */
 
-- 
2.14.1

[PATCH v3 5/5] scsi_debug: add resp_write_scat function

[Douglas Gilbert]

Add resp_write_scat() function to support decoding WRITE SCATTERED
(16 and 32). Also weave resp_write_scat() into the cdb decoding
logic.

Signed-off-by: Douglas Gilbert <dgilbert@interlog.com>
---
 drivers/scsi/scsi_debug.c | 179 +++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 176 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 3c56675c9b0c..32460c702c6a 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -93,6 +93,7 @@ static const char *sdebug_version_date = "20160430";
 #define MISCOMPARE_VERIFY_ASC 0x1d
 #define MICROCODE_CHANGED_ASCQ 0x1	/* with TARGET_CHANGED_ASC */
 #define MICROCODE_CHANGED_WO_RESET_ASCQ 0x16
+#define WRITE_ERROR_ASC 0xc
 
 /* Additional Sense Code Qualifier (ASCQ) */
 #define ACK_NAK_TO 0x3
@@ -327,7 +328,7 @@ enum sdeb_opcode_index {
 	SDEB_I_MAINT_IN = 14,
 	SDEB_I_MAINT_OUT = 15,
 	SDEB_I_VERIFY = 16,		/* 10 only */
-	SDEB_I_VARIABLE_LEN = 17,	/* READ(32), WRITE(32) */
+	SDEB_I_VARIABLE_LEN = 17,	/* READ(32), WRITE(32), WR_SCAT(32) */
 	SDEB_I_RESERVE = 18,		/* 6, 10 */
 	SDEB_I_RELEASE = 19,		/* 6, 10 */
 	SDEB_I_ALLOW_REMOVAL = 20,	/* PREVENT ALLOW MEDIUM REMOVAL */
@@ -396,6 +397,7 @@ static int resp_log_sense(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_readcap(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_read_dt0(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_write_dt0(struct scsi_cmnd *, struct sdebug_dev_info *);
+static int resp_write_scat(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_start_stop(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_readcap16(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_get_lba_status(struct scsi_cmnd *, struct sdebug_dev_info *);
@@ -457,6 +459,9 @@ static const struct opcode_info_t vl_iarr[] = {	/* VARIABLE LENGTH */
 	{0, 0x7f, 0xb, F_SA_HIGH | F_D_OUT | FF_MEDIA_IO, resp_write_dt0,
 	    NULL, {32,  0xc7, 0, 0, 0, 0, 0x3f, 0x18, 0x0, 0xb, 0xfa,
 		   0, 0xff, 0xff, 0xff, 0xff} },	/* WRITE(32) */
+	{0, 0x7f, 0x11, F_SA_HIGH | F_D_OUT | FF_MEDIA_IO, resp_write_scat,
+	    NULL, {32,  0xc7, 0, 0, 0, 0, 0x3f, 0x18, 0x0, 0x11, 0xf8,
+		   0, 0xff, 0xff, 0x0, 0x0} },	/* WRITE SCATTERED(32) */
 };
 
 static const struct opcode_info_t maint_in_iarr[] = {	/* MAINT IN */
@@ -528,8 +533,9 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
 	    resp_readcap16, sa_in_16_iarr, /* SA_IN(16), READ CAPACITY(16) */
 		{16,  0x10, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
 		 0xff, 0xff, 0xff, 0xff, 0x1, 0xc7} },
-	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL, /* SA_OUT(16) */
-	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0} },
+	{0, 0x9f, 0x12, F_SA_LOW | F_D_OUT | FF_MEDIA_IO, resp_write_scat,
+	    NULL, {16,  0x12, 0xf9, 0x0, 0xff, 0xff, 0, 0, 0xff, 0xff, 0xff,
+	    0xff, 0xff, 0xff, 0xff, 0xc7} },  /* SA_OUT(16), WRITE SCAT(16) */
 	{ARRAY_SIZE(maint_in_iarr), 0xa3, 0xa, F_SA_LOW | F_D_IN,
 	    resp_report_tgtpgs,	/* MAINT IN, REPORT TARGET PORT GROUPS */
 		maint_in_iarr, {12,  0xea, 0, 0, 0, 0, 0xff, 0xff, 0xff,
@@ -2988,6 +2994,173 @@ static int resp_write_dt0(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 	return 0;
 }
 
+/*
+ * T10 has only specified WRITE SCATTERED(16) and WRITE SCATTERED(32).
+ * No READ GATHERED yet (requires bidi or long cdb holding gather list).
+ */
+static int resp_write_scat(struct scsi_cmnd *scp,
+			   struct sdebug_dev_info *devip)
+{
+	u8 *cmd = scp->cmnd;
+	u8 *lrdp = NULL;
+	u8 *up;
+	u8 wrprotect;
+	u16 lbdof, num_lrd, k;
+	u32 num, num_by, bt_len, lbdof_blen, sg_off, cum_lb;
+	u32 lb_size = sdebug_sector_size;
+	u32 ei_lba;
+	u64 lba;
+	unsigned long iflags;
+	int ret, res;
+	bool is_16;
+	static const u32 lrd_size = 32; /* + parameter list header size */
+
+	if (cmd[0] == VARIABLE_LENGTH_CMD) {
+		is_16 = false;
+		wrprotect = (cmd[10] >> 5) & 0x7;
+		lbdof = get_unaligned_be16(cmd + 12);
+		num_lrd = get_unaligned_be16(cmd + 16);
+		bt_len = get_unaligned_be32(cmd + 28);
+	} else {        /* that leaves WRITE SCATTERED(16) */
+		is_16 = true;
+		wrprotect = (cmd[2] >> 5) & 0x7;
+		lbdof = get_unaligned_be16(cmd + 4);
+		num_lrd = get_unaligned_be16(cmd + 8);
+		bt_len = get_unaligned_be32(cmd + 10);
+		if (unlikely(have_dif_prot)) {
+			if (sdebug_dif == T10_PI_TYPE2_PROTECTION &&
+			    wrprotect) {
+				mk_sense_invalid_opcode(scp);
+				return illegal_condition_result;
+			}
+			if ((sdebug_dif == T10_PI_TYPE1_PROTECTION ||
+			     sdebug_dif == T10_PI_TYPE3_PROTECTION) &&
+			     wrprotect == 0)
+				sdev_printk(KERN_ERR, scp->device,
+					    "Unprotected WR to DIF device\n");
+		}
+	}
+	if ((num_lrd == 0) || (bt_len == 0))
+		return 0;       /* T10 says these do-nothings are not errors */
+	if (lbdof == 0) {
+		if (sdebug_verbose)
+			sdev_printk(KERN_INFO, scp->device,
+				"%s: %s: LB Data Offset field bad\n",
+				my_name, __func__);
+		mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
+		return illegal_condition_result;
+	}
+	lbdof_blen = lbdof * lb_size;
+	if ((lrd_size + (num_lrd * lrd_size)) > lbdof_blen) {
+		if (sdebug_verbose)
+			sdev_printk(KERN_INFO, scp->device,
+				"%s: %s: LBA range descriptors don't fit\n",
+				my_name, __func__);
+		mk_sense_buffer(scp, ILLEGAL_REQUEST, INVALID_FIELD_IN_CDB, 0);
+		return illegal_condition_result;
+	}
+	lrdp = kzalloc(lbdof_blen, GFP_ATOMIC);
+	if (lrdp == NULL)
+		return SCSI_MLQUEUE_HOST_BUSY;
+	if (sdebug_verbose)
+		sdev_printk(KERN_INFO, scp->device,
+			"%s: %s: Fetch header+scatter_list, lbdof_blen=%u\n",
+			my_name, __func__, lbdof_blen);
+	res = fetch_to_dev_buffer(scp, lrdp, lbdof_blen);
+	if (res == -1) {
+		ret = DID_ERROR << 16;
+		goto err_out;
+	}
+
+	write_lock_irqsave(&atomic_rw, iflags);
+	sg_off = lbdof_blen;
+	/* Spec says Buffer xfer Length field in number of LBs in dout */
+	cum_lb = 0;
+	for (k = 0, up = lrdp + lrd_size; k < num_lrd; ++k, up += lrd_size) {
+		lba = get_unaligned_be64(up + 0);
+		num = get_unaligned_be32(up + 8);
+		if (sdebug_verbose)
+			sdev_printk(KERN_INFO, scp->device,
+				"%s: %s: k=%d  LBA=0x%llx num=%u  sg_off=%u\n",
+				my_name, __func__, k, lba, num, sg_off);
+		if (num == 0)
+			continue;
+		ret = check_device_access_params(scp, lba, num);
+		if (ret)
+			goto err_out_unlock;
+		num_by = num * lb_size;
+		ei_lba = is_16 ? 0 : get_unaligned_be32(up + 12);
+
+		if ((cum_lb + num) > bt_len) {
+			if (sdebug_verbose)
+				sdev_printk(KERN_INFO, scp->device,
+				    "%s: %s: sum of blocks > data provided\n",
+				    my_name, __func__);
+			mk_sense_buffer(scp, ILLEGAL_REQUEST, WRITE_ERROR_ASC,
+					0);
+			ret = illegal_condition_result;
+			goto err_out_unlock;
+		}
+
+		/* DIX + T10 DIF */
+		if (unlikely(sdebug_dix && scsi_prot_sg_count(scp))) {
+			int prot_ret = prot_verify_write(scp, lba, num,
+							 ei_lba);
+
+			if (prot_ret) {
+				mk_sense_buffer(scp, ILLEGAL_REQUEST, 0x10,
+						prot_ret);
+				ret = illegal_condition_result;
+				goto err_out_unlock;
+			}
+		}
+
+		ret = do_device_access(scp, sg_off, lba, num, true);
+		if (unlikely(scsi_debug_lbp()))
+			map_region(lba, num);
+		if (unlikely(-1 == ret)) {
+			ret = DID_ERROR << 16;
+			goto err_out_unlock;
+		} else if (unlikely(sdebug_verbose && (ret < num_by)))
+			sdev_printk(KERN_INFO, scp->device,
+			    "%s: write: cdb indicated=%u, IO sent=%d bytes\n",
+			    my_name, num_by, ret);
+
+		if (unlikely(sdebug_any_injecting_opt)) {
+			struct sdebug_queued_cmd *sqcp =
+				(struct sdebug_queued_cmd *)scp->host_scribble;
+
+			if (sqcp) {
+				if (sqcp->inj_recovered) {
+					mk_sense_buffer(scp, RECOVERED_ERROR,
+							THRESHOLD_EXCEEDED, 0);
+					ret = illegal_condition_result;
+					goto err_out_unlock;
+				} else if (sqcp->inj_dif) {
+					/* Logical block guard check failed */
+					mk_sense_buffer(scp, ABORTED_COMMAND,
+							0x10, 1);
+					ret = illegal_condition_result;
+					goto err_out_unlock;
+				} else if (sqcp->inj_dix) {
+					mk_sense_buffer(scp, ILLEGAL_REQUEST,
+							0x10, 1);
+					ret = illegal_condition_result;
+					goto err_out_unlock;
+				}
+			}
+		}
+		sg_off += num_by;
+		cum_lb += num;
+	}
+	ret = 0;
+err_out_unlock:
+	write_unlock_irqrestore(&atomic_rw, iflags);
+err_out:
+	kfree(lrdp);
+	return ret;
+}
+
 static int resp_write_same(struct scsi_cmnd *scp, u64 lba, u32 num,
 			   u32 ei_lba, bool unmap, bool ndob)
 {
-- 
2.14.1

Re: [PATCH v3 0/5] scsi_debug: add write scattered support

[Martin K. Petersen]

Douglas,

> While testing the WRITE SCATTERED command support in a new sg3_utils
> utility (sg_write_x) it was helpful to have a target that supported
> this command. This command might be attractive to other kernel
> subsystems. Even if end devices don't support this command yet, it
> would most likely be a performance win if SCSI LLDs supported it (by
> breaking it down to a series of WRITE commands), as that would cut
> down the overhead of the block layer, the ULD (e.g. sd) and the SCSI
> midlevel.

Applied to 4.16/scsi-queue, thanks!

-- 
Martin K. Petersen	Oracle Linux Engineering