All of lore.kernel.org
 help / color / mirror / Atom feed
From: Quinn Tran <quinn.tran@qlogic.com>
To: Christoph Hellwig <hch@infradead.org>
Cc: Himanshu Madhani <himanshu.madhani@qlogic.com>,
	"target-devel@vger.kernel.org" <target-devel@vger.kernel.org>,
	"nab@linux-iscsi.org" <nab@linux-iscsi.org>,
	Giridhar Malavali <giridhar.malavali@qlogic.com>,
	linux-scsi <linux-scsi@vger.kernel.org>
Subject: Re: [PATCH 10/20] qla2xxx: Fix interaction issue between qla2xxx and Target Core Module
Date: Mon, 14 Dec 2015 21:59:11 +0000	[thread overview]
Message-ID: <D2947AEC.1B91E%quinn.tran@qlogic.com> (raw)
In-Reply-To: <20151214103449.GA8095@infradead.org>

[-- Attachment #1: Type: text/plain, Size: 1716 bytes --]

Christoph,  Thanks for reviewing.  I¹ll withdraw this patch.  Will rework
with new code and submit at a later time.

Regards,
Quinn Tran




On 12/14/15, 2:34 AM, "Christoph Hellwig" <hch@infradead.org> wrote:

>On Wed, Dec 09, 2015 at 10:07:32PM +0000, Quinn Tran wrote:
>> >Err, no.  Looking into the refcount inside a kref is never the
>> >right thing to do.
>> 
>> QT> even for debug purpose??
>
>No.  Please treat struct kref as opaque.
>
>> QT> These bits provide indication as to where the command has traversed
>>in
>> the QLA code.  Each bit is set one time. Due to the async nature of the
>> TMR code, it triggers QLA driver to repeat this specific free path in
>>the
>> double free case.  This BUG_ON allows us trap it early on.
>> 
>> In one of the corner case (below), I need to overloaded it + lock for
>>the
>> cleanup process.
>
>Setting bits fundamentaly is a read/modify/write cycle.  You either
>need to use {set,clear,test}_bit or lock around these manipulations.
>
>> QT> The cmd->aborted flag is used to track the CMD_T_ABORT flag at TCM
>> level.  If the command have been requested to be aborted by TCM or
>>already
>> aborted, we advance it to the ?free" state because our hardware have
>> already started freeing up resources associated to this
>>command/exchange.
>> In this specific case(above), a XFER RDY was aborted by the TMR.
>> Returning the cmd to TCM to generate SCSI Status would generate
>>erroneous
>> HW error due to freed resource.
>
>I really think this nees to be updated on top of Bat's changes as a
>start and re-reviewed.  The amoutn of special casing and second guessing
>here is simply not sustainable in the long run.


[-- Attachment #2: winmail.dat --]
[-- Type: application/ms-tnef, Size: 5204 bytes --]

  reply	other threads:[~2015-12-14 21:57 UTC|newest]

Thread overview: 51+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-12-08  0:48 [PATCH 00/20] qla2xxx: Patches for target-pending branch Himanshu Madhani
2015-12-08  0:48 ` [PATCH 01/20] qla2xxx: Enable Extended Login support Himanshu Madhani
2015-12-08 15:51   ` Hannes Reinecke
2015-12-08 19:35     ` Himanshu Madhani
2015-12-08  0:48 ` [PATCH 02/20] qla2xxx: Enable Exchange offload support Himanshu Madhani
2015-12-08 15:52   ` Hannes Reinecke
2015-12-08  0:48 ` [PATCH 03/20] qla2xxx: Enable Target counters in DebugFS Himanshu Madhani
2015-12-08 15:52   ` Hannes Reinecke
2015-12-08  0:48 ` [PATCH 04/20] qla2xxx: Add FW resource count " Himanshu Madhani
2015-12-08 15:53   ` Hannes Reinecke
2015-12-08  0:48 ` [PATCH 05/20] qla2xxx: Added interface to send ELS commands from driver Himanshu Madhani
2015-12-08  2:10   ` kbuild test robot
2015-12-08  2:10   ` [PATCH] qla2xxx: fix ifnullfree.cocci warnings kbuild test robot
2015-12-08 15:54   ` [PATCH 05/20] qla2xxx: Added interface to send ELS commands from driver Hannes Reinecke
2015-12-08  0:48 ` [PATCH 06/20] qla2xxx: Delete session if initiator is gone from FW Himanshu Madhani
2015-12-08  1:41   ` kbuild test robot
2015-12-08 15:58   ` Hannes Reinecke
2015-12-08  0:48 ` [PATCH 07/20] qla2xxx: Wait for all conflicts before ack'ing PLOGI Himanshu Madhani
2015-12-08 16:00   ` Hannes Reinecke
2015-12-08  0:48 ` [PATCH 08/20] qla2xxx: Replace QLA_TGT_STATE_ABORTED with a bit Himanshu Madhani
2015-12-08 16:01   ` Hannes Reinecke
2015-12-08  0:48 ` [PATCH 09/20] qla2xxx: Change check_stop_free to always return 1 Himanshu Madhani
2015-12-08  2:33   ` Christoph Hellwig
2015-12-09  6:56   ` Hannes Reinecke
2015-12-10  1:06     ` Quinn Tran
2015-12-08  0:48 ` [PATCH 10/20] qla2xxx: Fix interaction issue between qla2xxx and Target Core Module Himanshu Madhani
2015-12-08  2:37   ` Christoph Hellwig
2015-12-09 22:07     ` Quinn Tran
2015-12-14 10:34       ` Christoph Hellwig
2015-12-14 21:59         ` Quinn Tran [this message]
2015-12-09  7:01   ` Hannes Reinecke
2015-12-09 22:41     ` Quinn Tran
2015-12-08  0:48 ` [PATCH 11/20] qla2xxx: Add TAS detection for kernel 3.15 n newer Himanshu Madhani
2015-12-08  2:48   ` Christoph Hellwig
2015-12-09 20:24     ` Quinn Tran
2015-12-14 10:37       ` Christoph Hellwig
2015-12-14 22:00         ` Quinn Tran
2015-12-09  7:02   ` Hannes Reinecke
2015-12-08  0:48 ` [PATCH 12/20] target/tmr: LUN reset cause cmd premature free Himanshu Madhani
2015-12-08  2:48   ` Christoph Hellwig
2015-12-09 20:11     ` Quinn Tran
2016-01-04  7:44     ` Bart Van Assche
2015-12-09  7:03   ` Hannes Reinecke
2015-12-08  0:49 ` [PATCH 13/20] qla2xxx: Remove dependency on hardware_lock to reduce lock contention Himanshu Madhani
2015-12-08  0:49 ` [PATCH 14/20] qla2xxx: Add irq affinity notification Himanshu Madhani
2015-12-08  0:49 ` [PATCH 15/20] qla2xxx: Add selective command queuing Himanshu Madhani
2015-12-08  0:49 ` [PATCH 16/20] qla2xxx: Move atioq to a different lock to reduce lock contention Himanshu Madhani
2015-12-08  0:49 ` [PATCH 17/20] qla2xxx: Disable ZIO at start time Himanshu Madhani
2015-12-08  0:49 ` [PATCH 18/20] qla2xxx: Set all queues to 4k Himanshu Madhani
2015-12-08  0:49 ` [PATCH 19/20] qla2xxx: Add bulk send for atio & ctio completion paths Himanshu Madhani
2015-12-08  0:49 ` [PATCH 20/20] qla2xxx: Check for online flag instead of active reset when transmitting responses Himanshu Madhani

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=D2947AEC.1B91E%quinn.tran@qlogic.com \
    --to=quinn.tran@qlogic.com \
    --cc=giridhar.malavali@qlogic.com \
    --cc=hch@infradead.org \
    --cc=himanshu.madhani@qlogic.com \
    --cc=linux-scsi@vger.kernel.org \
    --cc=nab@linux-iscsi.org \
    --cc=target-devel@vger.kernel.org \
    --subject='Re: [PATCH 10/20] qla2xxx: Fix interaction issue between qla2xxx and Target Core Module' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.