[ovs-dev] [PATCH] [PATCH ovn] ovn-nbctl: Monitor nb_cfg to detect and handle potential overflows

Numan Siddique numans at ovn.org
Thu Aug 19 15:28:29 UTC 2021


On Wed, Aug 18, 2021 at 8:44 PM <mheib at redhat.com> wrote:
>
> From: Mohammad Heib <mheib at redhat.com>
>
> ovn-nbctl sync command will increase nb_cfg value each time it is executed
> with a specific wait_type, this increment will be handled without testing
> the current nb_cfg value because it is not monitored and that could lead
> to an overflow issue if nb_cfg == LLONG_MAX.
>
> To avoid such potential overflow cases we must monitor the real value
> of nb_cfg each time sync is executed and if there is any overflow issue
> it will be handled by function nbctl_pre_execute later on the execution.
>
> Fixes: be3a60f8e6a3 ("ovn-nbctl: Deal with nb_cfg overflows.")
> Reported-at: https://bugzilla.redhat.com/show_bug.cgi?id=1979774
> Signed-off-by: Mohammad Heib <mheib at redhat.com>

Thanks for the patch and fixing this issue.

Would you mind adding a test case in tests/ovn-nbctl.at to make sure
that the nb_cfg value is wrapped when it is about to overflow.

Thanks
Numan

> ---
>  utilities/ovn-nbctl.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/utilities/ovn-nbctl.c b/utilities/ovn-nbctl.c
> index ada53b662d3c..69be775bc567 100644
> --- a/utilities/ovn-nbctl.c
> +++ b/utilities/ovn-nbctl.c
> @@ -830,6 +830,8 @@ static void
>  nbctl_pre_sync(struct ctl_context *base OVS_UNUSED)
>  {
>      force_wait = true;
> +    /* Monitor nb_cfg to detect and handle potential overflows. */
> +    ovsdb_idl_add_column(base->idl, &nbrec_nb_global_col_nb_cfg);
>  }
>
>  static void
> --
> 2.27.0
>
> _______________________________________________
> dev mailing list
> dev at openvswitch.org
> https://mail.openvswitch.org/mailman/listinfo/ovs-dev
>


More information about the dev mailing list