[nvmewin] ProcessIO Function

[Chang, Alex]

Yes, I'd agree make it as simple as possible. However, there are two
places in ProcessIo returning FALSE without calling StorPortNotification
to complete the request:
Failure on calling storportGetCurrentProcessorNumber.
Failure on calling NVMeMapCore2Queue.
We should complete the request when either one happens?
 
Thanks,
Alex

________________________________

From: Luse, Paul E [mailto:paul.e.luse at intel.com] 
Sent: Thursday, January 19, 2012 11:46 AM
To: Chang, Alex; nvmewin at lists.openfabrics.org
Subject: RE: ProcessIO Function


Ahh, OK thanks.  I'd prefer we simply have it by rule:
 
-         If process IO fails then the IO is complete to storport (if it
had an SRB) with the appropriate status
-         If process IO succeeds then the IO is in flight
 
If we add this flag then we also have to change the return value for
process IO so the caller know why it failed so it can return the IO, if
needed to storport.  No point in having every caller implement code for
'return status busy' when it can be done in one central location where
the error happens. Make sense?  
 
Thx
Paul
 
 
From: Chang, Alex [mailto:Alex.Chang at idt.com] 
Sent: Thursday, January 19, 2012 12:27 PM
To: Luse, Paul E; nvmewin at lists.openfabrics.org
Subject: RE: ProcessIO Function
 
Hi Paul,
 
Sorry, I did not mean init state machine. It's the new Format NVM state
machine. After Format NVM command completes successfully, Identify
commands are being issued to re-fetch the structures. We all call
ProcessIo to issue the commands and its return type is BOOLEAN, which
only indicates whether the command had been issued or not. In some error
cases, such as failure on getting CmdID, ProcessIo calls
StorPortNotification to complete the request and callers have no way to
tell if the request had been completed or not. To avoid complete the
request twice, I'd like to suggest adding one extra parameter in
ProcessIO like:
BOOLEAN
ProcessIo(
    __in PNVME_DEVICE_EXTENSION pAdapterExtension,
    __in PNVME_SRB_EXTENSION pSrbExtension,
    __in NVME_QUEUE_TYPE QueueType,
    __out RequestCompleted
)
Thanks,
Alex
________________________________

From: Luse, Paul E [mailto:paul.e.luse at intel.com] 
Sent: Thursday, January 19, 2012 11:06 AM
To: Chang, Alex; nvmewin at lists.openfabrics.org
Subject: RE: ProcessIO Function
Hi Alex-
 
I'm not totally sure I understand what you are trying to say but I think
I do.  What does "In SNTI codes" mean?  I assume you're saying that
there's some inconsistency with what some callers are assuming about the
return value from ProcessIO() and, if so, good catch!  Clearly we cannot
complete the same IO twice :-)  Haven't seen your formatNVM code yet but
if any of the sub-commands you need to issue as art of handling
formatNVM fails then you should fail the whole command gracefully.
Also, how does any of this relate to init state machine?
 
We may not have time to talk about this in the meeting so if you could
reply and identify specific cases where you see callers of ProcessIO
doing the wrong thing and propose a fix that would be great.  I don't
believe we want the caller to have to complete the IO if processIO
fails, procession should do that however just looking at the code
doesn't consistently do that.  We should scrub it so that callers know
that if procession fails that the IO has been completed and if it
completes the IO has been issued.  We should also fix procession to
complete all failures with appropriate error codes.
 
Thanks
Paul
 
From: Chang, Alex [mailto:Alex.Chang at idt.com] 
Sent: Thursday, January 19, 2012 11:40 AM
To: Luse, Paul E; nvmewin at lists.openfabrics.org
Subject: ProcessIO Function
 
Hi all
 
I tested Format NVM last night and it basically works fine. However,
when I re-visited the state machine, there is potential problem related
to ProcessIo function, which completes the request back to Storport in
error cases. The return value of ProcessIo only indicates whether the
command had been issued to controller or not. It does NOT tell if it
completes the request. In SNTI codes, Ray re-uses the Srb Extension to
issue command(s). If ProcessIO fails, ASSERTION is called. Should I do
the same if it fails when re-fetching Identify structures after Format
NVM succeeds? Question is we don't want to complete the same request
twice. We should talk about this later.
 
Thanks,
Alex
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