[PATCH] qla2xxx: Return the fabric command state for non-task management requests

[PATCH] qla2xxx: Return the fabric command state for non-task management requests

[Spencer Baugh]

From: Dilip Kumar Uppugandla <dilip@purestorage.com>

Invoking get_cmd_state for qla2xxx always returns 0. Instead change it
to return the actual fabric state from qla_tgt_cmd. This will help with
debugging.

Signed-off-by: Dilip Kumar Uppugandla <dilip@purestorage.com>
Signed-off-by: Spencer Baugh <sbaugh@catern.com>
---
 drivers/scsi/qla2xxx/tcm_qla2xxx.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
index d9a8c60..e859586 100644
--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
+++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
@@ -420,6 +420,12 @@ static void tcm_qla2xxx_set_default_node_attrs(struct se_node_acl *nacl)
 
 static int tcm_qla2xxx_get_cmd_state(struct se_cmd *se_cmd)
 {
+	if (!(se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
+		struct qla_tgt_cmd *cmd = container_of(se_cmd,
+				struct qla_tgt_cmd, se_cmd);
+		return cmd->state;
+	}
+
 	return 0;
 }
 
-- 
2.4.3

Re: [PATCH] qla2xxx: Return the fabric command state for non-task management requests

[Himanshu Madhani]

On 7/21/15, 3:07 PM, "Spencer Baugh" <sbaugh@catern.com> wrote:

>From: Dilip Kumar Uppugandla <dilip@purestorage.com>
>
>Invoking get_cmd_state for qla2xxx always returns 0. Instead change it
>to return the actual fabric state from qla_tgt_cmd. This will help with
>debugging.
>
>Signed-off-by: Dilip Kumar Uppugandla <dilip@purestorage.com>
>Signed-off-by: Spencer Baugh <sbaugh@catern.com>
>---
> drivers/scsi/qla2xxx/tcm_qla2xxx.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
>diff --git a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
>b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
>index d9a8c60..e859586 100644
>--- a/drivers/scsi/qla2xxx/tcm_qla2xxx.c
>+++ b/drivers/scsi/qla2xxx/tcm_qla2xxx.c
>@@ -420,6 +420,12 @@ static void
>tcm_qla2xxx_set_default_node_attrs(struct se_node_acl *nacl)
> 
> static int tcm_qla2xxx_get_cmd_state(struct se_cmd *se_cmd)
> {
>+	if (!(se_cmd->se_cmd_flags & SCF_SCSI_TMR_CDB)) {
>+		struct qla_tgt_cmd *cmd = container_of(se_cmd,
>+				struct qla_tgt_cmd, se_cmd);
>+		return cmd->state;
>+	}
>+
> 	return 0;
> }
> 
>-- 
>2.4.3
>
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Looks Good. 

Acked-by: Himanshu Madhani <himanshu.madhani@qlogic.com>

>

Re: [PATCH] qla2xxx: Return the fabric command state for non-task management requests

[Christoph Hellwig]

On Tue, Jul 21, 2015 at 03:07:55PM -0700, Spencer Baugh wrote:
> From: Dilip Kumar Uppugandla <dilip@purestorage.com>
> 
> Invoking get_cmd_state for qla2xxx always returns 0. Instead change it
> to return the actual fabric state from qla_tgt_cmd. This will help with
> debugging.

I think the ->get_cmd_state callback should go away instead.  Returning
values with zero meaning to the core in a callback doesn't make much
sense.  I'd rather build some real structured debugging infrastructure,
so it would be useful if you could explain the use case for this.

Re: [PATCH] qla2xxx: Return the fabric command state for non-task management requests

[Christoph Hellwig]

Which debug printk do you care about?  I'd much prefer having a trace
point inside the driver which could even pretty print it instead of the
hack where a driver defined binary value is printed by the core.

Re: [PATCH] qla2xxx: Return the fabric command state for non-task management requests

[Quinn Tran]

Christoph,

Currently, the command state within TCM (se_cmd.t_state) only track
command states from the point of new to the Back End and from Back End up
to QLA driver.  From the debug perspective, that¹s only half the picture.
The other half comes from qla2xxx¹s private command state provided by this
patch.

Having another trace point that happens 5~10 seconds ago might be
difficult to back track.  For task management debugging, dumping the
current states (se_cmd + qla_tgt_cmd) of each command when the TMR is
received provides some benefit.

If you feel uncomfortable with the "driver defined binary", one
alternative would be to translate QLA¹s private command state into
se_cmd¹s new field.  This new file would be modify by the fabric layer
only.  This would limit any regression with existing se_cmd field
modification.


Regards,
Quinn Tran




On 7/24/15, 11:29 PM, "target-devel-owner@vger.kernel.org on behalf of
Christoph Hellwig" <target-devel-owner@vger.kernel.org on behalf of
hch@infradead.org> wrote:

>Which debug printk do you care about?  I'd much prefer having a trace
>point inside the driver which could even pretty print it instead of the
>hack where a driver defined binary value is printed by the core.
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