[libvirt] [PATCH 3/3] virsh: Notify users about disconnects

[John Ferlan]

On 09/17/2015 08:23 AM, Jiri Denemark wrote:
> After my "client rpc: Report proper error for keepalive disconnections"
> patch, virsh would no long print a warning when it closes a connection
> to a daemon after a keepalive timeout. Although the warning
> 
>     virsh # 2015-09-15 10:59:26.729+0000: 642080: info :
>     libvirt version: 1.2.19
>     2015-09-15 10:59:26.729+0000: 642080: warning :
>     virKeepAliveTimerInternal:143 : No response from client
>     0x7efdc0a46730 after 1 keepalive messages in 2 seconds
> 
> was pretty ugly, it was still useful. This patch brings the useful part
> back while making it much nicer:
> 
> virsh # error: Disconnected from qemu:///system due to keepalive timeout
> 
> Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
> ---
>  tools/virsh.c | 35 ++++++++++++++++++++++++++++++++---
>  1 file changed, 32 insertions(+), 3 deletions(-)
> 

Patch series seems reasonable to me, except for one minor thing....
Found by my coverity checker...  Naturally

> diff --git a/tools/virsh.c b/tools/virsh.c
> index bb12dec..23436ea 100644
> --- a/tools/virsh.c
> +++ b/tools/virsh.c
> @@ -95,12 +95,41 @@ static int disconnected; /* we may have been disconnected */
>   * handler, just save the fact it was raised.
>   */
>  static void
> -virshCatchDisconnect(virConnectPtr conn ATTRIBUTE_UNUSED,
> +virshCatchDisconnect(virConnectPtr conn,
>                       int reason,
> -                     void *opaque ATTRIBUTE_UNUSED)
> +                     void *opaque)
>  {
> -    if (reason != VIR_CONNECT_CLOSE_REASON_CLIENT)
> +    if (reason != VIR_CONNECT_CLOSE_REASON_CLIENT) {

[1]

> +        vshControl *ctl = opaque;
> +        const char *str = "unknown reason";
> +        virErrorPtr error;
> +        char *uri;
> +
> +        error = virSaveLastError();
> +        uri = virConnectGetURI(conn);
> +
> +        switch ((virConnectCloseReason) reason) {
> +        case VIR_CONNECT_CLOSE_REASON_ERROR:
> +            str = N_("Disconnected from %s due to I/O error");
> +            break;
> +        case VIR_CONNECT_CLOSE_REASON_EOF:
> +            str = N_("Disconnected from %s due to end of file");
> +            break;
> +        case VIR_CONNECT_CLOSE_REASON_KEEPALIVE:
> +            str = N_("Disconnected from %s due to keepalive timeout");
> +            break;
> +        case VIR_CONNECT_CLOSE_REASON_CLIENT:

[1]        ^^^ Coverity complains about DEADCODE

Other than setting str = NULL and testing for it later, I'm not exactly
sure of the 'best' course of action.  e.g., if (str) { vshError();
disconnected++; }

I think if this is handled, then the series is ACK-able.

John

> +        case VIR_CONNECT_CLOSE_REASON_LAST:
> +            break;
> +        }
> +        vshError(ctl, _(str), NULLSTR(uri));
> +
> +        if (error) {
> +            virSetError(error);
> +            virFreeError(error);
> +        }
>          disconnected++;
> +    }
>  }
>  
>  /* Main Function which should be used for connecting.
>