From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Disseldorp <ddiss@suse.de>
Date: Sun, 25 Nov 2018 23:10:00 +0000
Subject: Re: SPC-3 persistent reservations race condition
Message-Id: <20181126001000.35e947d6@suse.de>
List-Id: <target-devel.vger.kernel.org>
References: <3ee76029-a49c-e5ce-39c8-62af5f4ce711@zoner.cz>
In-Reply-To: <3ee76029-a49c-e5ce-39c8-62af5f4ce711@zoner.cz>
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To: target-devel@vger.kernel.org

Hi Martin,

On Thu, 22 Nov 2018 19:47:19 +0100, Martin Svec wrote:
...
> Please download the trace from https://www.maatts.eu/lio-pr.pcap. It's a merge of captures of two
> target SAN interfaces (10.22.1.208, 10.22.2.208). The deadlock occured in 18:57:17 CET. I guess it
> was caused by packets 5979 and 5980:
> 
> 5979    62.915577    10.22.102.66    10.22.1.208    iSCSI    126    SCSI: Persistent Reserve Out
> LUN: 0x01 SCSI: Data Out LUN: 0x01 (Persistent Reserve Out Request Data)
> 5980    62.915722    10.22.102.52    10.22.2.208    iSCSI    126    SCSI: Persistent Reserve Out
> LUN: 0x01 SCSI: Data Out LUN: 0x01 (Persistent Reserve Out Request Data)

I've attempted to trigger this via a new libiscsi test published at:
https://github.com/ddiss/libiscsi/
branch: test_mpio_async_prout_preempt

I haven't had any luck so far against mainline kernel, but am interested
to hear whether you're able to trigger the deadlock against your target.
It can be run via:

# make
./test-tool/iscsi-test-cu -V --dataloss --test=SCSI.MultipathIO.ProutPreemptAsync \
	iscsi://$TARGET_IP/$IQN/$LUN \
	iscsi://$TARGET_IP/$IQN/$LUN

You can use different or matching portal IPs for the two iSCSI target
URIs above.

Cheers, David