[libvirt] [PATCH] Fix handling of VIR_EVENT_HANDLE_ERROR in QEMU monitor
Daniel Veillard
veillard at redhat.com
Thu Jun 2 12:59:18 UTC 2011
On Thu, Jun 02, 2011 at 11:52:10AM +0100, Daniel P. Berrange wrote:
> Commit 4454a9efc728b91e791b1f14c26ea23a19d57f48 introduced bad
> behaviour on the VIR_EVENT_HANDLE_ERROR condition. This condition
> is only hit when an invalid FD is used in poll() (typically due
> to a double-close bug). The QEMU monitor code was treating this
> condition as non-fatal, and thus libvirt would poll() in a fast
> loop forever burning 100% CPU. VIR_EVENT_HANDLE_ERROR must be
> handled in the same way as VIR_EVENT_HANDLE_HANGUP, killing the
> QEMU instance.
>
> * src/qemu/qemu_monitor.c: Treat VIR_EVENT_HANDLE_ERROR as EOF
> ---
> src/qemu/qemu_monitor.c | 9 +++++----
> 1 files changed, 5 insertions(+), 4 deletions(-)
>
> diff --git a/src/qemu/qemu_monitor.c b/src/qemu/qemu_monitor.c
> index 09a1b8e..26bb814 100644
> --- a/src/qemu/qemu_monitor.c
> +++ b/src/qemu/qemu_monitor.c
> @@ -535,14 +535,14 @@ qemuMonitorIO(int watch, int fd, int events, void *opaque) {
> #endif
>
> if (mon->fd != fd || mon->watch != watch) {
> - if (events & VIR_EVENT_HANDLE_HANGUP)
> + if (events & (VIR_EVENT_HANDLE_HANGUP | VIR_EVENT_HANDLE_ERROR))
> eof = true;
> qemuReportError(VIR_ERR_INTERNAL_ERROR,
> _("event from unexpected fd %d!=%d / watch %d!=%d"),
> mon->fd, fd, mon->watch, watch);
> error = true;
> } else if (mon->lastError.code != VIR_ERR_OK) {
> - if (events & VIR_EVENT_HANDLE_HANGUP)
> + if (events & (VIR_EVENT_HANDLE_HANGUP | VIR_EVENT_HANDLE_ERROR))
> eof = true;
> error = true;
> } else {
> @@ -581,8 +581,9 @@ qemuMonitorIO(int watch, int fd, int events, void *opaque) {
> if (!error && !eof &&
> events & VIR_EVENT_HANDLE_ERROR) {
> qemuReportError(VIR_ERR_INTERNAL_ERROR,
> - _("Error while waiting for monitor"));
> - error = 1;
> + _("Invalid file descriptor while waiting for monitor"));
> + eof = 1;
> + events &= ~VIR_EVENT_HANDLE_ERROR;
> }
> if (!error && events) {
> qemuReportError(VIR_ERR_INTERNAL_ERROR,
Hum, that serious ! ACK
Daniel
--
Daniel Veillard | libxml Gnome XML XSLT toolkit http://xmlsoft.org/
daniel at veillard.com | Rpmfind RPM search engine http://rpmfind.net/
http://veillard.com/ | virtualization library http://libvirt.org/
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