From fa229bcba8f49eaaba2a69f57bb4ebac95387d92 Mon Sep 17 00:00:00 2001
From: mav <mav@FreeBSD.org>
Date: Mon, 29 Oct 2012 14:18:54 +0000
Subject: Make GEOM RAID more aggressive in marking volumes as clean on
 shutdown and move that action from shutdown_pre_sync to shutdown_post_sync
 stage to avoid extra flapping.

ZFS tends to not close devices on shutdown, that doesn't allow GEOM RAID
to shutdown gracefully.  To handle that, mark volume as clean just when
shutdown time comes and there are no active writes.

MFC after:	2 weeks
---
 sys/geom/raid/g_raid.c | 37 ++++++++++++++++++++-----------------
 1 file changed, 20 insertions(+), 17 deletions(-)

(limited to 'sys/geom/raid/g_raid.c')

diff --git a/sys/geom/raid/g_raid.c b/sys/geom/raid/g_raid.c
index d03c2e8..e720c07 100644
--- a/sys/geom/raid/g_raid.c
+++ b/sys/geom/raid/g_raid.c
@@ -108,8 +108,9 @@ LIST_HEAD(, g_raid_tr_class) g_raid_tr_classes =
 LIST_HEAD(, g_raid_volume) g_raid_volumes =
     LIST_HEAD_INITIALIZER(g_raid_volumes);
 
-static eventhandler_tag g_raid_pre_sync = NULL;
+static eventhandler_tag g_raid_post_sync = NULL;
 static int g_raid_started = 0;
+static int g_raid_shutdown = 0;
 
 static int g_raid_destroy_geom(struct gctl_req *req, struct g_class *mp,
     struct g_geom *gp);
@@ -881,7 +882,7 @@ g_raid_orphan(struct g_consumer *cp)
 	    G_RAID_EVENT_DISK);
 }
 
-static int
+static void
 g_raid_clean(struct g_raid_volume *vol, int acw)
 {
 	struct g_raid_softc *sc;
@@ -892,22 +893,21 @@ g_raid_clean(struct g_raid_volume *vol, int acw)
 	sx_assert(&sc->sc_lock, SX_XLOCKED);
 
 //	if ((sc->sc_flags & G_RAID_DEVICE_FLAG_NOFAILSYNC) != 0)
-//		return (0);
+//		return;
 	if (!vol->v_dirty)
-		return (0);
+		return;
 	if (vol->v_writes > 0)
-		return (0);
+		return;
 	if (acw > 0 || (acw == -1 &&
 	    vol->v_provider != NULL && vol->v_provider->acw > 0)) {
 		timeout = g_raid_clean_time - (time_uptime - vol->v_last_write);
-		if (timeout > 0)
-			return (timeout);
+		if (!g_raid_shutdown && timeout > 0)
+			return;
 	}
 	vol->v_dirty = 0;
 	G_RAID_DEBUG1(1, sc, "Volume %s marked as clean.",
 	    vol->v_name);
 	g_raid_write_metadata(sc, vol, NULL, NULL);
-	return (0);
 }
 
 static void
@@ -1520,8 +1520,7 @@ process:
 				g_raid_disk_done_request(bp);
 		} else if (rv == EWOULDBLOCK) {
 			TAILQ_FOREACH(vol, &sc->sc_volumes, v_next) {
-				if (vol->v_writes == 0 && vol->v_dirty)
-					g_raid_clean(vol, -1);
+				g_raid_clean(vol, -1);
 				if (bioq_first(&vol->v_inflight) == NULL &&
 				    vol->v_tr) {
 					t.tv_sec = g_raid_idle_threshold / 1000000;
@@ -1783,7 +1782,7 @@ g_raid_access(struct g_provider *pp, int acr, int acw, int ace)
 		error = ENXIO;
 		goto out;
 	}
-	if (dcw == 0 && vol->v_dirty)
+	if (dcw == 0)
 		g_raid_clean(vol, dcw);
 	vol->v_provider_open += acr + acw + ace;
 	/* Handle delayed node destruction. */
@@ -2379,21 +2378,25 @@ g_raid_dumpconf(struct sbuf *sb, const char *indent, struct g_geom *gp,
 }
 
 static void
-g_raid_shutdown_pre_sync(void *arg, int howto)
+g_raid_shutdown_post_sync(void *arg, int howto)
 {
 	struct g_class *mp;
 	struct g_geom *gp, *gp2;
 	struct g_raid_softc *sc;
+	struct g_raid_volume *vol;
 	int error;
 
 	mp = arg;
 	DROP_GIANT();
 	g_topology_lock();
+	g_raid_shutdown = 1;
 	LIST_FOREACH_SAFE(gp, &mp->geom, geom, gp2) {
 		if ((sc = gp->softc) == NULL)
 			continue;
 		g_topology_unlock();
 		sx_xlock(&sc->sc_lock);
+		TAILQ_FOREACH(vol, &sc->sc_volumes, v_next)
+			g_raid_clean(vol, -1);
 		g_cancel_event(sc);
 		error = g_raid_destroy(sc, G_RAID_DESTROY_DELAYED);
 		if (error != 0)
@@ -2408,9 +2411,9 @@ static void
 g_raid_init(struct g_class *mp)
 {
 
-	g_raid_pre_sync = EVENTHANDLER_REGISTER(shutdown_pre_sync,
-	    g_raid_shutdown_pre_sync, mp, SHUTDOWN_PRI_FIRST);
-	if (g_raid_pre_sync == NULL)
+	g_raid_post_sync = EVENTHANDLER_REGISTER(shutdown_post_sync,
+	    g_raid_shutdown_post_sync, mp, SHUTDOWN_PRI_FIRST);
+	if (g_raid_post_sync == NULL)
 		G_RAID_DEBUG(0, "Warning! Cannot register shutdown event.");
 	g_raid_started = 1;
 }
@@ -2419,8 +2422,8 @@ static void
 g_raid_fini(struct g_class *mp)
 {
 
-	if (g_raid_pre_sync != NULL)
-		EVENTHANDLER_DEREGISTER(shutdown_pre_sync, g_raid_pre_sync);
+	if (g_raid_post_sync != NULL)
+		EVENTHANDLER_DEREGISTER(shutdown_post_sync, g_raid_post_sync);
 	g_raid_started = 0;
 }
 
-- 
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