On 4/7/17 12:01 PM, Bryant G. Ly wrote:
On 4/7/17 11:36 AM, Bart Van Assche wrote:
On Fri, 2017-04-07 at 11:12 -0500, Bryant G. Ly wrote:
So from this stack trace it looks like the ibmvscsis driver is
sending an
extra response through send_messages even though an abort was issued.
IBMi, reported this issue internally when they were testing the driver,
because their client didn't like getting a response back for the
aborted op.
They are only expecting a TMR from the abort request, NOT the
aborted op.
Hello Bryant,
What is the root cause of this behavior? Why is it that the behavior of
the ibmvscsi_tgt contradicts what has been implemented in the LIO core?
Sorry but the patch at the start of this thread looks to me like an
attempt to paper over the problem instead of addressing the root cause.
Thanks,
IBMi clients received a response for an aborted operation, so they
sent an abort tm request.
Afterwards they get a CRQ response to the op that they aborted. That
should not happen, because they are only supposed to get a response
for the tm request NOT the aborted operation.
Looking at the code it looks like it is due to send messages,
processing a response without checking to see if it was an aborted op.
This patch addresses a bug within the ibmvscsis driver and the fact
that it SENT a response to the aborted operation(which is wrong since)
without looking at what LIO core had done.
The driver isn't supposed to send any response to the aborted
operation, BUT only a response to the abort tm request, which LIO core
currently does.
-Bryant
I think I can clarify the issue here: ibmvscsis_tgt does not send the
response to the client until release_cmd time. The reason for this was
because if we did it at queue_status time, then the client would be free
to reuse the tag for that command, but we're still using the tag until
the command is released at release_cmd time, so we chose to delay
sending the response until then.
That then caused this issue, because release_cmd is always called, even
if queue_status is not. Perhaps it would be cleaner to set some sort of
status valid flag during queue_status instead of setting a flag in
aborted_task?
