Re: [PATCH v2 1/3] scsi: protect req->aiocb with AioContext lock

[Eric Blake]

On Fri, Feb 10, 2023 at 09:32:36AM -0500, Stefan Hajnoczi wrote:
> If requests are being processed in the IOThread when a SCSIDevice is
> unplugged, scsi_device_purge_requests() -> scsi_req_cancel_async() races
> with I/O completion callbacks. Both threads load and store req->aiocb.
> This can lead to assert(r->req.aiocb == NULL) failures and undefined
> behavior.
> 
> Protect r->req.aiocb with the AioContext lock to prevent the race.

I understand that we're trying to get rid of this lock down the road,
but until then, properly using it to guard things is appropriate.

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
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