[PATCH 0/4] scsi_debug: Unit Attention fixes/enhancements

[PATCH 0/4] scsi_debug: Unit Attention fixes/enhancements

[Ewan D. Milne]

From: "Ewan D. Milne" <emilne@redhat.com>

This patch series fixes a couple of problems in the code to generate UAs
when "virtual_gb" is changed, and adds the generation of a UA when "max_luns"
is changed.  It also adds the generation of a UA when a WRITE BUFFER
command is issued.

Patches were generated against jejb for-next branch, with Doug Gilbert's
earlier patches applied.

Ewan D. Milne (4):
  scsi_debug: Fixed missing "break;" in SDEBUG_UA_CAPACITY_CHANGED case
  scsi_debug: Added taking of sdebug_host_list_lock when changing
    capacity
  scsi_debug: Add REPORTED LUNS DATA HAS CHANGED Unit Attention
  scsi_debug: Implement WRITE BUFFER command

 drivers/scsi/scsi_debug.c | 131 ++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 128 insertions(+), 3 deletions(-)

-- 
1.7.11.7

[PATCH 1/4] scsi_debug: Fixed missing "break;" in SDEBUG_UA_CAPACITY_CHANGED case

[Ewan D. Milne]

From: "Ewan D. Milne" <emilne@redhat.com>

This eliminates a superfluous log message when the capacity is changed:

  "check_readiness: unexpected unit attention code=3"

Signed-off-by: Ewan D. Milne <emilne@redhat.com>
---
 drivers/scsi/scsi_debug.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index aa4b6b8..397cc10 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -817,6 +817,7 @@ static int check_readiness(struct scsi_cmnd *SCpnt, int uas_only,
 					UA_CHANGED_ASC, CAPACITY_CHANGED_ASCQ);
 			if (debug)
 				cp = "capacity data changed";
+			break;
 		default:
 			pr_warn("%s: unexpected unit attention code=%d\n",
 				__func__, k);
-- 
1.7.11.7

Re: [PATCH 1/4] scsi_debug: Fixed missing "break;" in SDEBUG_UA_CAPACITY_CHANGED case

[Douglas Gilbert]

On 14-12-04 11:49 AM, Ewan D. Milne wrote:
> From: "Ewan D. Milne" <emilne@redhat.com>
>
> This eliminates a superfluous log message when the capacity is changed:
>
>    "check_readiness: unexpected unit attention code=3"
>
> Signed-off-by: Ewan D. Milne <emilne@redhat.com>

Thanks.

Acked-by: Douglas Gilbert <dgilbert@interlog.com>

[PATCH 2/4] scsi_debug: Added taking of sdebug_host_list_lock when changing capacity

[Ewan D. Milne]

From: "Ewan D. Milne" <emilne@redhat.com>

All other traversals of the sdebug_host_list take the lock.

Signed-off-by: Ewan D. Milne <emilne@redhat.com>
---
 drivers/scsi/scsi_debug.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 397cc10..1a11466 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -4439,6 +4439,7 @@ static ssize_t virtual_gb_store(struct device_driver *ddp, const char *buf,
 			struct sdebug_host_info *sdhp;
 			struct sdebug_dev_info *dp;
 
+			spin_lock(&sdebug_host_list_lock);
 			list_for_each_entry(sdhp, &sdebug_host_list,
 					    host_list) {
 				list_for_each_entry(dp, &sdhp->dev_info_list,
@@ -4447,6 +4448,7 @@ static ssize_t virtual_gb_store(struct device_driver *ddp, const char *buf,
 						dp->uas_bm);
 				}
 			}
+			spin_unlock(&sdebug_host_list_lock);
 		}
 		return count;
 	}
-- 
1.7.11.7

Re: [PATCH 2/4] scsi_debug: Added taking of sdebug_host_list_lock when changing capacity

[Douglas Gilbert]

On 14-12-04 11:49 AM, Ewan D. Milne wrote:
> From: "Ewan D. Milne" <emilne@redhat.com>
>
> All other traversals of the sdebug_host_list take the lock.
>
> Signed-off-by: Ewan D. Milne <emilne@redhat.com>

Thanks.

Acked-by: Douglas Gilbert <dgilbert@interlog.com>

[PATCH 3/4] scsi_debug: Add REPORTED LUNS DATA HAS CHANGED Unit Attention

[Ewan D. Milne]

From: "Ewan D. Milne" <emilne@redhat.com>

Generate a REPORTED LUNS DATA HAS CHANGED Unit Attention if
sysfs "max_luns" is used to change the number of scsi_debug LUNs.
This is only done if scsi_debug_scsi_level is SPC-3 or above.
Additionally, implement SPC-4 behavior which only generates
this Unit Attention on the first LUN on the target to receive
a command after the change.  This condition is cleared when
a REPORT LUNS command is received.

Signed-off-by: Ewan D. Milne <emilne@redhat.com>
---
 drivers/scsi/scsi_debug.c | 56 ++++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 55 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 1a11466..648abf2 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -80,6 +80,8 @@ static const char *scsi_debug_version_date = "20141022";
 #define INVALID_FIELD_IN_PARAM_LIST 0x26
 #define UA_RESET_ASC 0x29
 #define UA_CHANGED_ASC 0x2a
+#define TARGET_CHANGED_ASC 0x3f
+#define LUNS_CHANGED_ASCQ 0x0e
 #define INSUFF_RES_ASC 0x55
 #define INSUFF_RES_ASCQ 0x3
 #define POWER_ON_RESET_ASCQ 0x0
@@ -181,7 +183,8 @@ static const char *scsi_debug_version_date = "20141022";
 #define SDEBUG_UA_BUS_RESET 1
 #define SDEBUG_UA_MODE_CHANGED 2
 #define SDEBUG_UA_CAPACITY_CHANGED 3
-#define SDEBUG_NUM_UAS 4
+#define SDEBUG_UA_LUNS_CHANGED 4
+#define SDEBUG_NUM_UAS 5
 
 /* for check_readiness() */
 #define UAS_ONLY 1	/* check for UAs only */
@@ -783,6 +786,22 @@ static int scsi_debug_ioctl(struct scsi_device *dev, int cmd, void __user *arg)
 	/* return -ENOTTY; // correct return but upsets fdisk */
 }
 
+static int clear_luns_changed_on_target(struct sdebug_dev_info *devip)
+{
+	struct sdebug_host_info *sdhp;
+	struct sdebug_dev_info *dp;
+
+	spin_lock(&sdebug_host_list_lock);
+	list_for_each_entry(sdhp, &sdebug_host_list, host_list) {
+		list_for_each_entry(dp, &sdhp->dev_info_list, dev_list) {
+			if ((devip->sdbg_host == dp->sdbg_host) &&
+			    (devip->target == dp->target))
+				clear_bit(SDEBUG_UA_LUNS_CHANGED, dp->uas_bm);
+		}
+	}
+	spin_unlock(&sdebug_host_list_lock);
+}
+
 static int check_readiness(struct scsi_cmnd *SCpnt, int uas_only,
 			   struct sdebug_dev_info * devip)
 {
@@ -818,6 +837,23 @@ static int check_readiness(struct scsi_cmnd *SCpnt, int uas_only,
 			if (debug)
 				cp = "capacity data changed";
 			break;
+		case SDEBUG_UA_LUNS_CHANGED:
+			/*
+			 * SPC-3 behavior is to report a UNIT ATTENTION with
+			 * ASC/ASCQ REPORTED LUNS DATA HAS CHANGED on every LUN
+			 * on the target, until a REPORT LUNS command is
+			 * received.  SPC-4 behavior is to report it only once.
+			 * NOTE:  scsi_debug_scsi_level does not use the same
+			 * values as struct scsi_device->scsi_level.
+			 */
+			if (scsi_debug_scsi_level >= 6)	/* SPC-4 and above */
+				clear_luns_changed_on_target(devip);
+			mk_sense_buffer(SCpnt, UNIT_ATTENTION,
+					TARGET_CHANGED_ASC,
+					LUNS_CHANGED_ASCQ);
+			if (debug)
+				cp = "reported luns data has changed";
+			break;
 		default:
 			pr_warn("%s: unexpected unit attention code=%d\n",
 				__func__, k);
@@ -3229,6 +3265,7 @@ static int resp_report_luns(struct scsi_cmnd * scp,
 	unsigned char arr[SDEBUG_RLUN_ARR_SZ];
 	unsigned char * max_addr;
 
+	clear_luns_changed_on_target(devip);
 	alloc_len = cmd[9] + (cmd[8] << 8) + (cmd[7] << 16) + (cmd[6] << 24);
 	shortish = (alloc_len < 4);
 	if (shortish || (select_report > 2)) {
@@ -4369,10 +4406,27 @@ static ssize_t max_luns_store(struct device_driver *ddp, const char *buf,
 			      size_t count)
 {
         int n;
+	bool changed;
 
 	if ((count > 0) && (1 == sscanf(buf, "%d", &n)) && (n >= 0)) {
+		changed = (scsi_debug_max_luns != n);
 		scsi_debug_max_luns = n;
 		sdebug_max_tgts_luns();
+		if (changed && (scsi_debug_scsi_level >= 5)) {	/* >= SPC-3 */
+			struct sdebug_host_info *sdhp;
+			struct sdebug_dev_info *dp;
+
+			spin_lock(&sdebug_host_list_lock);
+			list_for_each_entry(sdhp, &sdebug_host_list,
+					    host_list) {
+				list_for_each_entry(dp, &sdhp->dev_info_list,
+						    dev_list) {
+					set_bit(SDEBUG_UA_LUNS_CHANGED,
+						dp->uas_bm);
+				}
+			}
+			spin_unlock(&sdebug_host_list_lock);
+		}
 		return count;
 	}
 	return -EINVAL;
-- 
1.7.11.7

Re: [PATCH 3/4] scsi_debug: Add REPORTED LUNS DATA HAS CHANGED Unit Attention

[Douglas Gilbert]

On 14-12-04 11:49 AM, Ewan D. Milne wrote:
> From: "Ewan D. Milne" <emilne@redhat.com>
>
> Generate a REPORTED LUNS DATA HAS CHANGED Unit Attention if
> sysfs "max_luns" is used to change the number of scsi_debug LUNs.
> This is only done if scsi_debug_scsi_level is SPC-3 or above.
> Additionally, implement SPC-4 behavior which only generates
> this Unit Attention on the first LUN on the target to receive
> a command after the change.  This condition is cleared when
> a REPORT LUNS command is received.
>
> Signed-off-by: Ewan D. Milne <emilne@redhat.com>

Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>

[PATCH 4/4] scsi_debug: Implement WRITE BUFFER command

[Ewan D. Milne]

From: "Ewan D. Milne" <emilne@redhat.com>

Accept the WRITE BUFFER command and do nothing other than
set the appropriate "microcode has been changed" UA on the LU.

>From an earlier patch by Doug Gilbert.

Signed-off-by: Ewan D. Milne <emilne@redhat.com>
---
 drivers/scsi/scsi_debug.c | 74 +++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 71 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/scsi_debug.c b/drivers/scsi/scsi_debug.c
index 648abf2..5ac04d6 100644
--- a/drivers/scsi/scsi_debug.c
+++ b/drivers/scsi/scsi_debug.c
@@ -93,6 +93,8 @@ static const char *scsi_debug_version_date = "20141022";
 #define THRESHOLD_EXCEEDED 0x5d
 #define LOW_POWER_COND_ON 0x5e
 #define MISCOMPARE_VERIFY_ASC 0x1d
+#define MICROCODE_CHANGED_ASCQ 0x1	/* with TARGET_CHANGED_ASC */
+#define MICROCODE_CHANGED_WO_RESET_ASCQ 0x16
 
 /* Additional Sense Code Qualifier (ASCQ) */
 #define ACK_NAK_TO 0x3
@@ -184,7 +186,9 @@ static const char *scsi_debug_version_date = "20141022";
 #define SDEBUG_UA_MODE_CHANGED 2
 #define SDEBUG_UA_CAPACITY_CHANGED 3
 #define SDEBUG_UA_LUNS_CHANGED 4
-#define SDEBUG_NUM_UAS 5
+#define SDEBUG_UA_MICROCODE_CHANGED 5	/* simulate firmware change */
+#define SDEBUG_UA_MICROCODE_CHANGED_WO_RESET 6
+#define SDEBUG_NUM_UAS 7
 
 /* for check_readiness() */
 #define UAS_ONLY 1	/* check for UAs only */
@@ -330,6 +334,7 @@ static int resp_write_same_10(struct scsi_cmnd *, struct sdebug_dev_info *);
 static int resp_write_same_16(struct scsi_cmnd *, struct sdebug_dev_info *);
 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 *);
 
 struct opcode_info_t {
 	u8 num_attached;	/* 0 if this is it (i.e. a leaf); use 0xff
@@ -484,8 +489,9 @@ static const struct opcode_info_t opcode_info_arr[SDEB_I_LAST_ELEMENT + 1] = {
 	{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,
 		   0, 0, 0, 0, 0, 0} },
-	{0, 0, 0, F_INV_OP | FF_RESPOND, NULL, NULL, /* WRITE_BUFFER */
-	    {0,  0, 0, 0, 0, 0, 0, 0, 0, 0, 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,
 			      0xff, 0xc7, 0, 0, 0, 0, 0, 0} },
@@ -837,6 +843,19 @@ static int check_readiness(struct scsi_cmnd *SCpnt, int uas_only,
 			if (debug)
 				cp = "capacity data changed";
 			break;
+		case SDEBUG_UA_MICROCODE_CHANGED:
+			mk_sense_buffer(SCpnt, UNIT_ATTENTION,
+				 TARGET_CHANGED_ASC, MICROCODE_CHANGED_ASCQ);
+			if (debug)
+				cp = "microcode has been changed";
+			break;
+		case SDEBUG_UA_MICROCODE_CHANGED_WO_RESET:
+			mk_sense_buffer(SCpnt, UNIT_ATTENTION,
+					TARGET_CHANGED_ASC,
+					MICROCODE_CHANGED_WO_RESET_ASCQ);
+			if (debug)
+				cp = "microcode has been changed without reset";
+			break;
 		case SDEBUG_UA_LUNS_CHANGED:
 			/*
 			 * SPC-3 behavior is to report a UNIT ATTENTION with
@@ -3070,6 +3089,55 @@ resp_write_same_16(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 	return resp_write_same(scp, lba, num, ei_lba, unmap, ndob);
 }
 
+/* Note the mode field is in the same position as the (lower) service action
+ * field. For the Report supported operation codes command, SPC-4 suggests
+ * each mode of this command should be reported separately; for future. */
+static int
+resp_write_buffer(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
+{
+	u8 *cmd = scp->cmnd;
+	struct scsi_device *sdp = scp->device;
+	struct sdebug_dev_info *dp;
+	u8 mode;
+
+	mode = cmd[1] & 0x1f;
+	switch (mode) {
+	case 0x4:	/* download microcode (MC) and activate (ACT) */
+		/* set UAs on this device only */
+		set_bit(SDEBUG_UA_BUS_RESET, devip->uas_bm);
+		set_bit(SDEBUG_UA_MICROCODE_CHANGED, devip->uas_bm);
+		break;
+	case 0x5:	/* download MC, save and ACT */
+		set_bit(SDEBUG_UA_MICROCODE_CHANGED_WO_RESET, devip->uas_bm);
+		break;
+	case 0x6:	/* download MC with offsets and ACT */
+		/* set UAs on most devices (LUs) in this target */
+		list_for_each_entry(dp,
+				    &devip->sdbg_host->dev_info_list,
+				    dev_list)
+			if (dp->target == sdp->id) {
+				set_bit(SDEBUG_UA_BUS_RESET, dp->uas_bm);
+				if (devip != dp)
+					set_bit(SDEBUG_UA_MICROCODE_CHANGED,
+						dp->uas_bm);
+			}
+		break;
+	case 0x7:	/* download MC with offsets, save, and ACT */
+		/* set UA on all devices (LUs) in this target */
+		list_for_each_entry(dp,
+				    &devip->sdbg_host->dev_info_list,
+				    dev_list)
+			if (dp->target == sdp->id)
+				set_bit(SDEBUG_UA_MICROCODE_CHANGED_WO_RESET,
+					dp->uas_bm);
+		break;
+	default:
+		/* do nothing for this command for other mode values */
+		break;
+	}
+	return 0;
+}
+
 static int
 resp_comp_write(struct scsi_cmnd *scp, struct sdebug_dev_info *devip)
 {
-- 
1.7.11.7

Re: [PATCH 4/4] scsi_debug: Implement WRITE BUFFER command

[Douglas Gilbert]

On 14-12-04 11:49 AM, Ewan D. Milne wrote:
> From: "Ewan D. Milne" <emilne@redhat.com>
>
> Accept the WRITE BUFFER command and do nothing other than
> set the appropriate "microcode has been changed" UA on the LU.
>
>>From an earlier patch by Doug Gilbert.
>
> Signed-off-by: Ewan D. Milne <emilne@redhat.com>

Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Tested-by: Douglas Gilbert <dgilbert@interlog.com>

Re: [PATCH 0/4] scsi_debug: Unit Attention fixes/enhancements

[Douglas Gilbert]

On 14-12-04 11:49 AM, Ewan D. Milne wrote:
> From: "Ewan D. Milne" <emilne@redhat.com>
>
> This patch series fixes a couple of problems in the code to generate UAs
> when "virtual_gb" is changed, and adds the generation of a UA when "max_luns"
> is changed.  It also adds the generation of a UA when a WRITE BUFFER
> command is issued.
>
> Patches were generated against jejb for-next branch, with Doug Gilbert's
> earlier patches applied.
>
> Ewan D. Milne (4):
>    scsi_debug: Fixed missing "break;" in SDEBUG_UA_CAPACITY_CHANGED case
>    scsi_debug: Added taking of sdebug_host_list_lock when changing
>      capacity
>    scsi_debug: Add REPORTED LUNS DATA HAS CHANGED Unit Attention
>    scsi_debug: Implement WRITE BUFFER command
>
>   drivers/scsi/scsi_debug.c | 131 ++++++++++++++++++++++++++++++++++++++++++++--
>   1 file changed, 128 insertions(+), 3 deletions(-)

Great work. I have acked and tested each item (i.e. 1 through 4).

I have some other scsi_debug clean ups (e.g. neuter
the host_lock option) but they can wait until the 3.20 series.


BTW I did notice a small regression compared to the existing
"big switch" version of the scsi_debug driver: the VERIFY and the
PREVENT ALLOW MEDIUM REMOVAL commands were accepted (but did
little). Now they are rejected. If that bites anyone, it could
be corrected as a bug fix in 3.19 .

Doug Gilbert

Re: [PATCH 0/4] scsi_debug: Unit Attention fixes/enhancements

[Christoph Hellwig]

Thanks, applied patch 1 and 2 to drivers-for-3.19, the rest will go
into the 3.20 queue a soon as that opens.