From: Rusty Russell <rusty@rustcorp.com.au>
To: Mark Wu <dwu@redhat.com>
Cc: "Michael S. Tsirkin" <mst@redhat.com>,
virtualization@lists.linux-foundation.org, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org, Jens Axboe <axboe@kernel.dk>,
tj@kernel.org, Greg Kroah-Hartman <gregkh@suse.de>
Subject: Re: [PATCH 1/1] [virt] virtio-blk: Use ida to allocate disk index
Date: Thu, 09 Jun 2011 08:51:05 +0930 [thread overview]
Message-ID: <87mxhrgba6.fsf@rustcorp.com.au> (raw)
In-Reply-To: <4DEF744D.9040702@redhat.com>
On Wed, 08 Jun 2011 09:08:29 -0400, Mark Wu <dwu@redhat.com> wrote:
> Hi Rusty,
> Yes, I can't figure out an instance of disk probing in parallel either, but as
> per the following commit, I think we still need use lock for safety. What's your opinion?
>
> commit 4034cc68157bfa0b6622efe368488d3d3e20f4e6
> Author: Tejun Heo <tj@kernel.org>
> Date: Sat Feb 21 11:04:45 2009 +0900
>
> [SCSI] sd: revive sd_index_lock
>
> Commit f27bac2761cab5a2e212dea602d22457a9aa6943 which converted sd to
> use ida instead of idr incorrectly removed sd_index_lock around id
> allocation and free. idr/ida do have internal locks but they protect
> their free object lists not the allocation itself. The caller is
> responsible for that. This missing synchronization led to the same id
> being assigned to multiple devices leading to oops.
I'm confused. Tejun, Greg, anyone can probes happen in parallel?
If so, I'll have to review all my drivers.
Thanks,
Rusty.
next prev parent reply other threads:[~2011-06-08 23:27 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-06-01 7:24 [PATCH 1/1] [virt] virtio-blk: Use ida to allocate disk index Mark Wu
2011-06-01 8:25 ` Mark Wu
2011-06-02 10:34 ` Michael S. Tsirkin
2011-06-08 13:12 ` Mark Wu
2011-06-01 23:57 ` Rusty Russell
2011-06-08 13:08 ` Mark Wu
2011-06-08 23:21 ` Rusty Russell [this message]
2011-06-08 23:45 ` Greg KH
2011-06-09 9:14 ` Tejun Heo
2011-06-09 10:41 ` Mark Wu
2011-06-15 4:51 ` Rusty Russell
2011-06-15 7:06 ` Tejun Heo
2011-06-16 0:05 ` Rusty Russell
2011-06-16 7:46 ` Tejun Heo
2011-10-19 10:12 ` Michael S. Tsirkin
2011-10-24 10:02 ` Michael S. Tsirkin
2011-10-24 10:02 ` Jens Axboe
2011-10-25 1:07 ` Rusty Russell
2011-06-02 10:33 ` Michael S. Tsirkin
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