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Date: Tue, 10 Jun 2014 10:08:46 +0200
From: Paolo Bonzini <pbonzini@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH] block/iscsi: fix potential segfault on
	early callback
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To: Peter Lieven <pl@kamp.de>, qemu-devel@nongnu.org
Cc: kwolf@redhat.com, stefanha@redhat.com

Il 10/06/2014 09:52, Peter Lieven ha scritto:
> it might happen in the future that a function directly invokes its callback.
> In this case we end up in a segfault because the iTask is gone when the BH
> is scheduled.
>
> Signed-off-by: Peter Lieven <pl@kamp.de>
> ---
>  block/iscsi.c |    5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/block/iscsi.c b/block/iscsi.c
> index 019b324..4bf4238 100644
> --- a/block/iscsi.c
> +++ b/block/iscsi.c
> @@ -146,6 +146,7 @@ iscsi_schedule_bh(IscsiAIOCB *acb)
>  static void iscsi_co_generic_bh_cb(void *opaque)
>  {
>      struct IscsiTask *iTask = opaque;
> +    iTask->complete = 1;
>      qemu_bh_delete(iTask->bh);
>      qemu_coroutine_enter(iTask->co, NULL);
>  }
> @@ -153,6 +154,7 @@ static void iscsi_co_generic_bh_cb(void *opaque)
>  static void iscsi_retry_timer_expired(void *opaque)
>  {
>      struct IscsiTask *iTask = opaque;
> +    iTask->complete = 1;
>      if (iTask->co) {
>          qemu_coroutine_enter(iTask->co, NULL);
>      }
> @@ -171,7 +173,6 @@ iscsi_co_generic_cb(struct iscsi_context *iscsi, int status,
>      struct IscsiTask *iTask = opaque;
>      struct scsi_task *task = command_data;
>
> -    iTask->complete = 1;
>      iTask->status = status;
>      iTask->do_retry = 0;
>      iTask->task = task;
> @@ -209,6 +210,8 @@ out:
>          iTask->bh = aio_bh_new(iTask->iscsilun->aio_context,
>                                 iscsi_co_generic_bh_cb, iTask);
>          qemu_bh_schedule(iTask->bh);
> +    } else {
> +        iTask->complete = 1;
>      }
>  }
>
>

Applied, thanks.  I'll leave the nfs patch to Kevin and/or Stefan.

Paolo