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From: Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <ede94233-e969-0de4-c8ee-a9ff91ce808a@redhat.com>
Date: Thu, 24 May 2018 08:04:59 +0200
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Subject: Re: [Qemu-devel] [PATCH] block: fix QEMU crash with scsi-hd and
 drive_del
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To: Greg Kurz <groug@kaod.org>, Stefan Hajnoczi <stefanha@redhat.com>
Cc: Kevin Wolf <kwolf@redhat.com>, qemu-devel@nongnu.org, Max Reitz <mreitz@redhat.com>

On 23/05/2018 16:46, Greg Kurz wrote:
> Maybe change bdrv_root_unref_child() to ensure we don't call
> bdrv_close() with pending I/O requests ?
> 
>  void bdrv_root_unref_child(BdrvChild *child)
>  {
>      BlockDriverState *child_bs;
>  
>      child_bs = child->bs;
> +    bdrv_drained_begin(child_bs);
>      bdrv_detach_child(child);
> +    bdrv_drained_end(child_bs);
>      bdrv_unref(child_bs);
>  }

Maybe bdrv_detach_child should do it.

Paolo