[PATCH RESEND 5/5] bridge_driver: Replace and drop networkKillDaemon

[Marc-André Lureau]

Hi

On Mon, Mar 23, 2020 at 5:14 PM Michal Privoznik <mprivozn at redhat.com> wrote:
>
> In the network driver code there's networkKillDaemon() which is
> the same as virProcessKillPainfully(). Replace the former with
> the later and drop what becomes unused function.
>
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
>  src/network/bridge_driver.c | 106 ++++++------------------------------
>  1 file changed, 18 insertions(+), 88 deletions(-)
>
> diff --git a/src/network/bridge_driver.c b/src/network/bridge_driver.c
> index ae52455761..f06099297a 100644
> --- a/src/network/bridge_driver.c
> +++ b/src/network/bridge_driver.c
> @@ -966,67 +966,6 @@ static int networkConnectIsAlive(virConnectPtr conn G_GNUC_UNUSED)
>  }
>
>
> -/* networkKillDaemon:
> - *
> - * kill the specified pid/name, and wait a bit to make sure it's dead.
> - */
> -static int
> -networkKillDaemon(pid_t pid,
> -                  const char *daemonName,
> -                  const char *networkName)
> -{
> -    size_t i;
> -    int ret = -1;
> -    const char *signame = "TERM";
> -
> -    /* send SIGTERM, then wait up to 3 seconds for the process to
> -     * disappear, send SIGKILL, then wait for up to another 2
> -     * seconds. If that fails, log a warning and continue, hoping
> -     * for the best.
> -     */
> -    for (i = 0; i < 25; i++) {
> -        int signum = 0;
> -        if (i == 0) {
> -            signum = SIGTERM;
> -        } else if (i == 15) {
> -            signum = SIGKILL;
> -            signame = "KILL";
> -        }
> -        if (kill(pid, signum) < 0) {
> -            if (errno == ESRCH) {
> -                ret = 0;
> -            } else {
> -                VIR_WARN("Failed to terminate %s process %d "
> -                         "for network '%s' with SIG%s: %s",
> -                         daemonName, pid, networkName, signame,
> -                         g_strerror(errno));
> -            }
> -            return ret;
> -        }
> -        /* NB: since networks have no reference count like
> -         * domains, there is no safe way to unlock the network
> -         * object temporarily, and so we can't follow the
> -         * procedure used by the qemu driver of 1) unlock driver
> -         * 2) sleep, 3) add ref to object 4) unlock object, 5)
> -         * re-lock driver, 6) re-lock object. We may need to add
> -         * that functionality eventually, but for now this
> -         * function is rarely used and, at worst, leaving the
> -         * network driver locked during this loop of sleeps will
> -         * have the effect of holding up any other thread trying
> -         * to make modifications to a network for up to 5 seconds;
> -         * since modifications to networks are much less common
> -         * than modifications to domains, this seems a reasonable
> -         * tradeoff in exchange for less code disruption.
> -         */
> -        g_usleep(20 * 1000);
> -    }
> -    VIR_WARN("Timed out waiting after SIG%s to %s process %d "
> -             "(network '%s')",
> -             signame, daemonName, pid, networkName);
> -    return ret;
> -}
> -
> -
>  /* the following does not build a file, it builds a list
>   * which is later saved into a file
>   */
> @@ -1832,12 +1771,11 @@ static int
>  networkRestartDhcpDaemon(virNetworkDriverStatePtr driver,
>                           virNetworkObjPtr obj)
>  {
> -    virNetworkDefPtr def = virNetworkObjGetDef(obj);
>      pid_t dnsmasqPid = virNetworkObjGetDnsmasqPid(obj);
>
>      /* if there is a running dnsmasq, kill it */
>      if (dnsmasqPid > 0) {
> -        networkKillDaemon(dnsmasqPid, "dnsmasq", def->name);
> +        virProcessKillPainfully(dnsmasqPid, false);

ok
Simiarly, it may be more consistent and solid to use virCommand
pidfile handling than dnsmasq pid-file.

>          virNetworkObjSetDnsmasqPid(obj, -1);
>      }
>      /* now start dnsmasq if it should be started */
> @@ -2066,23 +2004,19 @@ networkRefreshRadvd(virNetworkDriverStatePtr driver,
>  {
>      virNetworkDefPtr def = virNetworkObjGetDef(obj);
>      dnsmasqCapsPtr dnsmasq_caps = networkGetDnsmasqCaps(driver);
> -    char *radvdpidbase;
> +    g_autofree char *radvdpidbase = NULL;
> +    g_autofree char *pidfile = NULL;
>      pid_t radvdPid;
>
>      /* Is dnsmasq handling RA? */
>      if (DNSMASQ_RA_SUPPORT(dnsmasq_caps)) {
>          virObjectUnref(dnsmasq_caps);
> -        radvdPid = virNetworkObjGetRadvdPid(obj);
> -        if (radvdPid <= 0)
> -            return 0;
> -        /* radvd should not be running but in case it is */
> -        if ((networkKillDaemon(radvdPid, "radvd", def->name) >= 0) &&
> -            ((radvdpidbase = networkRadvdPidfileBasename(def->name))
> -             != NULL)) {
> -            virPidFileDelete(driver->pidDir, radvdpidbase);
> -            VIR_FREE(radvdpidbase);
> +        if ((radvdpidbase = networkRadvdPidfileBasename(def->name)) &&
> +            (pidfile = virPidFileBuildPath(driver->pidDir, radvdpidbase))) {
> +            /* radvd should not be running but in case it is */
> +            virPidFileForceCleanupPath(pidfile);
> +            virNetworkObjSetRadvdPid(obj, -1);
>          }


I doubt def->name can be NULL, thus all the if conditions seems
misleading to me. I guess the code inherits OOM handling.


> -        virNetworkObjSetRadvdPid(obj, -1);
>          return 0;
>      }
>      virObjectUnref(dnsmasq_caps);
> @@ -2110,23 +2044,19 @@ static int
>  networkRestartRadvd(virNetworkObjPtr obj)
>  {
>      virNetworkDefPtr def = virNetworkObjGetDef(obj);
> -    char *radvdpidbase;
> -    pid_t radvdPid = virNeworkObjGetRadvdPid(obj);
> +    g_autofree char *radvdpidbase = NULL;
> +    g_autofree char *pidfile = NULL;
>
> -    /* if there is a running radvd, kill it */
> -    if (radvdPid > 0) {
> -        /* essentially ignore errors from the following two functions,
> -         * since there's really no better recovery to be done than to
> -         * just push ahead (and that may be exactly what's needed).
> -         */
> -        if ((networkKillDaemon(radvdPid, "radvd", def->name) >= 0) &&
> -            ((radvdpidbase = networkRadvdPidfileBasename(def->name))
> -             != NULL)) {
> -            virPidFileDelete(driver->pidDir, radvdpidbase);
> -            VIR_FREE(radvdpidbase);
> -        }
> +    /* If there is a running radvd, kill it. Essentially ignore errors from the
> +     * following two functions, since there's really no better recovery to be
> +     * done than to just push ahead (and that may be exactly what's needed).
> +     */
> +    if ((radvdpidbase = networkRadvdPidfileBasename(def->name)) &&
> +        (pidfile = virPidFileBuildPath(driver->pidDir, radvdpidbase))) {
> +        virPidFileForceCleanupPath(pidfile);
>          virNetworkObjSetRadvdPid(obj, -1);
>      }
> +
>      /* now start radvd if it should be started */
>      return networkStartRadvd(obj);
>  }
> --
> 2.24.1
>

Reviewed-by: Marc-André Lureau <marcandre.lureau at redhat.com>


-- 
Marc-André Lureau