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References: <20220802034729.2566787-1-haowenchao@huawei.com> <3ba71030-982b-c98b-78ee-ceca74da3b57@oracle.com>
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From:   wenchao hao <haowenchao22@gmail.com>
Date:   Mon, 15 Aug 2022 00:56:10 +0800
Message-ID: <CAOptpSPLSbrQ8hgr275Ds7fwcBA_W9jYt0SFfhV-npPaz08S7g@mail.gmail.com>
Subject: Re: [PATCH v3] scsi: iscsi: Fix multiple iscsi session unbind event
 sent to userspace
To:     Mike Christie <michael.christie@oracle.com>
Cc:     Wenchao Hao <haowenchao@huawei.com>, Lee Duncan <lduncan@suse.com>,
        Chris Leech <cleech@redhat.com>,
        "James E . J . Bottomley" <jejb@linux.ibm.com>,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        open-iscsi@googlegroups.com, linux-scsi@vger.kernel.org,
        linux-kernel@vger.kernel.org, linfeilong@huawei.com
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On Fri, Aug 12, 2022 at 12:06 PM Mike Christie
<michael.christie@oracle.com> wrote:
>
> On 8/1/22 10:47 PM, Wenchao Hao wrote:
> > I found an issue that kernel would send ISCSI_KEVENT_UNBIND_SESSION
> > for multiple times which should be fixed.
> >
> > This patch introduce target_state in iscsi_cls_session to make
> > sure session would send only one ISCSI_KEVENT_UNBIND_SESSION.
> >
> > But this would break issue fixed in commit 13e60d3ba287 ("scsi: iscsi:
> > Report unbind session event when the target has been removed"). The issue
> > is iscsid died for any reason after it send unbind session to kernel, once
> > iscsid restart again, it loss kernel's ISCSI_KEVENT_UNBIND_SESSION event.
> >
> > Now kernel think iscsi_cls_session has already sent an
> > ISCSI_KEVENT_UNBIND_SESSION event and would not send it any more. Which
> > would cause userspace unable to logout. Actually the session is in
> > invalid state(it's target_id is INVALID), iscsid should not sync this
> > session in it's restart.
> >
> > So we need to check session's target state during iscsid restart,
> > if session is in unbound state, do not sync this session and perform
> > session teardown. It's reasonable because once a session is unbound, we
> > can not recover it any more(mainly because it's target id is INVALID)
> >
>
> I think we are ok now. Do you have a link to the userspace parts so
> I can make sure we have everything covered now?

I updated the PR on github: https://github.com/open-iscsi/open-iscsi/pull/339