Refine r301173 a bit.

- Don't execute any of g_mirror_shutdown_post_sync() when panicking. We
  cannot safely idle the mirror or stop synchronization in that state, and
  the current attempts to do so complicate debugging of gmirror itself.
- Check for a non-NULL panicstr instead of using SCHEDULER_STOPPED(). The
  latter was added for use in the locking primitives.

Reviewed by:	mav, pjd
MFC after:	2 weeks
Sponsored by:	Dell EMC Isilon

1 files changed, 4 insertions, 1 deletions

diff --git a/sys/geom/mirror/g_mirror.c b/sys/geom/mirror/g_mirror.c
index 02ca68b9cee8..f68a8926916c 100644
--- a/sys/geom/mirror/g_mirror.c
+++ b/sys/geom/mirror/g_mirror.c
@@ -3040,7 +3040,7 @@ g_mirror_destroy(struct g_mirror_softc *sc, int how)
 	g_topology_assert_not();
 	sx_assert(&sc->sc_lock, SX_XLOCKED);
 
-	if (sc->sc_provider_open != 0 || SCHEDULER_STOPPED()) {
+	if (sc->sc_provider_open != 0) {
 		switch (how) {
 		case G_MIRROR_DESTROY_SOFT:
 			G_MIRROR_DEBUG(1,
@@ -3374,6 +3374,9 @@ g_mirror_shutdown_post_sync(void *arg, int howto)
 	struct g_mirror_softc *sc;
 	int error;
 
+	if (panicstr != NULL)
+		return;
+
 	mp = arg;
 	g_topology_lock();
 	g_mirror_shutdown = 1;