[libvirt] [PATCHv3 1/6] DO NOT APPLY UPSTREAM: Close callback race corruption crash reproducer.

[Eric Blake]

On 03/31/2013 10:20 AM, Peter Krempa wrote:
> ---
>  src/remote/remote_driver.c | 5 +++++
>  src/rpc/virnetclient.c     | 9 ++++++++-
>  2 files changed, 13 insertions(+), 1 deletion(-)

While I agree that this must not be applied upstream, I applied it
locally and was indeed able to more reliably reproduce the problems.
Thanks; having this patch in place locally will make the rest of my
review easier.

> 
> diff --git a/src/remote/remote_driver.c b/src/remote/remote_driver.c
> index 885120e..711143a 100644
> --- a/src/remote/remote_driver.c
> +++ b/src/remote/remote_driver.c
> @@ -1027,6 +1027,11 @@ doRemoteClose(virConnectPtr conn, struct private_data *priv)
>               (xdrproc_t) xdr_void, (char *) NULL) == -1)
>          ret = -1;
> 
> +    /* this is needed so that the remote side has the time to close the socket */
> +    printf("\n\n DEBUG: Connection close called, sleeping\n\n");
> +    sleep(1);
> +    printf("\n\n DEBUG: Finishing close\n\n");
> +
>  #ifdef WITH_GNUTLS
>      virObjectUnref(priv->tls);
>      priv->tls = NULL;
> diff --git a/src/rpc/virnetclient.c b/src/rpc/virnetclient.c
> index 010c5c3..51b80a2 100644
> --- a/src/rpc/virnetclient.c
> +++ b/src/rpc/virnetclient.c
> @@ -674,8 +674,15 @@ virNetClientCloseLocked(virNetClientPtr client)
>              virKeepAliveStop(ka);
>              virObjectUnref(ka);
>          }
> -        if (closeCb)
> +        if (closeCb) {
> +            /* the callback has to delay for a while until the connection object
> +             * is being freed in the original thread that closed the connection
> +             * */
> +            printf("\n\n DEBUG: calling the close callback\n\n");
> +            sleep(2);
>              closeCb(client, closeReason, closeOpaque);
> +            printf("\n\n DEBUG: callback returned\n\n");
> +        }
> 
>          virObjectLock(client);
>          virObjectUnref(client);
> 

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org

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