Re: [libvirt] [PATCH v3 3/4] monitor: Prevent removing fd from set during init
On 10/17/2012 12:02 AM, Eric Blake wrote:
On 10/16/2012 12:08 PM, Corey Bryant wrote:
> If an fd is added to an fd set via the command line, and it is not
> referenced by another command line option (ie. -drive), then clean
> it up after QEMU initialization is complete.
>
> Signed-off-by: Corey Bryant <coreyb(a)linux.vnet.ibm.com>
> ---
> v3:
> - This patch was split into it's own patch in v3
> (eblake(a)redhat.com, kwolf(a)redhat.com)
>
> monitor.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
Reviewed-by: Eric Blake <eblake(a)redhat.com>
Thanks!
>
> diff --git a/monitor.c b/monitor.c
> index 5d5de41..0dae7ac 100644
> --- a/monitor.c
> +++ b/monitor.c
> @@ -2105,8 +2105,9 @@ static void monitor_fdset_cleanup(MonFdset *mon_fdset)
> MonFdsetFd *mon_fdset_fd_next;
>
> QLIST_FOREACH_SAFE(mon_fdset_fd, &mon_fdset->fds, next,
mon_fdset_fd_next) {
> - if (mon_fdset_fd->removed ||
> - (QLIST_EMPTY(&mon_fdset->dup_fds) && mon_refcount ==
0)) {
> + if ((mon_fdset_fd->removed ||
> + (QLIST_EMPTY(&mon_fdset->dup_fds) && mon_refcount ==
0)) &&
> + runstate_is_running()) {
This condition looks sufficient for command line parsing; however, I
have to wonder if there are any long-term ill effects, such as if I
pause a guest, then close an fdset, where qemu keeps the fd open until I
continue the guest. But thinking a bit more, we never promised that
qemu would close fds right away, but only that it wouldn't leak fds by
closing them whenever qemu thinks it is convenient.
I can't think of any ill effects. I think you may be able to remove an
fd or fd set followed by adding a drive using that fd set, but that is
just a difference in behavior compared to when a guest is running.
> close(mon_fdset_fd->fd);
> g_free(mon_fdset_fd->opaque);
> QLIST_REMOVE(mon_fdset_fd, next);
>
--
Regards,
Corey Bryant