[libvirt] [PATCH] fix Xen event handling

[Daniel P. Berrange]

On Wed, Mar 11, 2009 at 02:27:39PM +0100, Daniel Veillard wrote:
>  As was reported on IRC and found by Dan Berrange, sometimes Xen event
> handling could start to go wild and block processing of requests in the
> daemon.
>  The fault at least on libvirt side is that we didn't filter out non
> read/write event requests when asking for watches in the xenstore. The
> provided patch seems to work for the person who reported the original
> problem,

ACK, looks good & reporter confirmed that it works.


> Index: src/xs_internal.c
> ===================================================================
> RCS file: /data/cvs/libxen/src/xs_internal.c,v
> retrieving revision 1.88
> diff -u -u -r1.88 xs_internal.c
> --- src/xs_internal.c	5 Feb 2009 18:14:00 -0000	1.88
> +++ src/xs_internal.c	11 Mar 2009 13:23:17 -0000
> @@ -1215,7 +1215,7 @@
>  static void
>  xenStoreWatchEvent(int watch ATTRIBUTE_UNUSED,
>                     int fd ATTRIBUTE_UNUSED,
> -                   int events ATTRIBUTE_UNUSED,
> +                   int events,
>                     void *data)
>  {
>      char		 **event;
> @@ -1226,8 +1226,12 @@
>  
>      virConnectPtr        conn = data;
>      xenUnifiedPrivatePtr priv = (xenUnifiedPrivatePtr) conn->privateData;
> +
>      if(!priv) return;
>  
> +    /* only set a watch on read and write events */
> +    if (events & (VIR_EVENT_HANDLE_ERROR | VIR_EVENT_HANDLE_HANGUP)) return;
> +
>      xenUnifiedLock(priv);
>  
>      if(!priv->xshandle)

> --
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> Libvir-list at redhat.com
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