From: Kevin Wolf <kwolf@redhat.com>
To: John Snow <jsnow@redhat.com>
Cc: qemu-block@nongnu.org, vsementsov@virtuozzo.com,
stefanha@redhat.com, pbonzini@redhat.com, jcody@redhat.com,
qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH v3 0/6] jobs: fix transactional race condition
Date: Thu, 3 Nov 2016 14:21:59 +0100 [thread overview]
Message-ID: <20161103132159.GD5352@noname.redhat.com> (raw)
In-Reply-To: <1478109056-25198-1-git-send-email-jsnow@redhat.com>
Am 02.11.2016 um 18:50 hat John Snow geschrieben:
> There are a few problems with transactional job completion right now.
>
> First, if jobs complete so quickly they complete before remaining jobs
> get a chance to join the transaction, the completion mode can leave well
> known state and the QLIST can get corrupted and the transactional jobs
> can complete in batches or phases instead of all together.
>
> Second, if two or more jobs defer to the main loop at roughly the same
> time, it's possible for one job's cleanup to directly invoke the other
> job's cleanup from within the same thread, leading to a situation that
> will deadlock the entire transaction.
>
> Thanks to Vladimir for pointing out these modes of failure.
Patch 1-3 and 6:
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
prev parent reply other threads:[~2016-11-03 13:22 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-11-02 17:50 [Qemu-devel] [PATCH v3 0/6] jobs: fix transactional race condition John Snow
2016-11-02 17:50 ` [Qemu-devel] [PATCH v3 1/6] blockjob: fix dead pointer in txn list John Snow
2016-11-08 2:47 ` Jeff Cody
2016-11-02 17:50 ` [Qemu-devel] [PATCH v3 2/6] blockjob: add .clean property John Snow
2016-11-08 2:51 ` Jeff Cody
2016-11-02 17:50 ` [Qemu-devel] [PATCH v3 3/6] blockjob: add .start field John Snow
2016-11-08 2:58 ` Jeff Cody
2016-11-02 17:50 ` [Qemu-devel] [PATCH v3 4/6] blockjob: add block_job_start John Snow
2016-11-03 12:17 ` Kevin Wolf
2016-11-08 2:02 ` John Snow
2016-11-08 2:05 ` Jeff Cody
2016-11-08 2:20 ` John Snow
2016-11-08 9:16 ` Kevin Wolf
2016-11-02 17:50 ` [Qemu-devel] [PATCH v3 5/6] blockjob: refactor backup_start as backup_job_create John Snow
2016-11-03 13:17 ` Kevin Wolf
2016-11-08 5:41 ` John Snow
2016-11-08 9:11 ` Kevin Wolf
2016-11-08 15:24 ` John Snow
2016-11-08 18:30 ` Jeff Cody
2016-11-08 3:14 ` Jeff Cody
2016-11-02 17:50 ` [Qemu-devel] [PATCH v3 6/6] iotests: add transactional failure race test John Snow
2016-11-03 13:21 ` Kevin Wolf [this message]
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