Re: [PATCH v2 for-7.1 9/9] nbd: document what is protected by the CoMutexes

[Vladimir Sementsov-Ogievskiy]

14.04.2022 20:57, Paolo Bonzini wrote:
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
> ---
>   block/nbd.c | 8 +++++++-
>   1 file changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/block/nbd.c b/block/nbd.c
> index 31c684772e..d0d94b40bd 100644
> --- a/block/nbd.c
> +++ b/block/nbd.c
> @@ -81,12 +81,18 @@ typedef struct BDRVNBDState {
>       NBDClientRequest requests[MAX_NBD_REQUESTS];
>       QEMUTimer *reconnect_delay_timer;
>   
> +    /* Protects sending data on the socket.  */
>       CoMutex send_mutex;
> +
> +    /*
> +     * Protects receiving reply headers from the socket, as well as the
> +     * fields reply and requests[].receiving

I think, worth noting, that s->reply is used without mutex after 
nbd_receive_replies() success and till setting s->reply.handle to 0 in 
nbd_co_receive_one_chunk()..

Should "s->reply.handle = 0" be done under mutex as well? And may be, in same 
critical section as nbd_recv_coroutines_wake() ?

> +     */
>       CoMutex receive_mutex;
> +    NBDReply reply;
>   
>       QEMUTimer *open_timer;
>   
> -    NBDReply reply;
>       BlockDriverState *bs;
>   
>       /* Connection parameters */


--
Best regards,
Vladimir