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

[Jiri Denemark]

On Mon, Sep 21, 2015 at 17:32:41 -0400, John Ferlan wrote:
> 
> 
> 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.

I think /* coverity[dead_error_begin] */ is the right solution in this
case.

Jirka