Re: [PATCH v2 for-7.1 8/9] nbd: take receive_mutex when reading requests[].receiving

[Eric Blake <eblake@redhat.com>]

On Thu, Apr 14, 2022 at 07:57:55PM +0200, Paolo Bonzini wrote:
> requests[].receiving is set by nbd_receive_replies() under the receive_mutex;
> Read it under the same mutex as well.  Waking up receivers on errors happens
> after each reply finishes processing, in nbd_co_receive_one_chunk().
> If there is no currently-active reply, there are two cases:
> 
> * either there is no active request at all, in which case no
> element of request[] can have .receiving = true
> 
> * or nbd_receive_replies() must be running and owns receive_mutex;
> in that case it will get back to nbd_co_receive_one_chunk() because
> the socket has been shutdown, and all waiting coroutines will wake up
> in turn.
> 
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>  block/nbd.c | 15 +++++++--------
>  1 file changed, 7 insertions(+), 8 deletions(-)

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

-- 
Eric Blake, Principal Software Engineer
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