svn commit: r218083 - projects/graid/head/sys/geom/raid

[Alexander Motin]

Author: mav
Date: Sun Jan 30 07:49:44 2011
New Revision: 218083
URL: http://svn.freebsd.org/changeset/base/218083

Log:
  Implement delayed until last provider close node destruction.
  Use it on system shutdown to gracefully stop rebuild and other processes
  and close lower level providers, allowing them do the same.

Modified:
  projects/graid/head/sys/geom/raid/g_raid.c

Modified: projects/graid/head/sys/geom/raid/g_raid.c
==============================================================================
--- projects/graid/head/sys/geom/raid/g_raid.c	Sun Jan 30 02:17:47 2011	(r218082)
+++ projects/graid/head/sys/geom/raid/g_raid.c	Sun Jan 30 07:49:44 2011	(r218083)
@@ -92,7 +92,7 @@ LIST_HEAD(, g_raid_tr_class) g_raid_tr_c
 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_pre_sync = NULL;
 static int g_raid_started = 0;
 
 static int g_raid_destroy_geom(struct gctl_req *req, struct g_class *mp,
@@ -1212,7 +1212,7 @@ process:
 					vol->v_timeout(vol, vol->v_to_arg);
 			}
 		}
-		if (sc->sc_stopping != 0)
+		if (sc->sc_stopping == G_RAID_DESTROY_HARD)
 			g_raid_destroy_node(sc, 1);	/* May not return. */
 	}
 }
@@ -1441,9 +1441,9 @@ g_raid_update_disk(struct g_raid_disk *d
 static int
 g_raid_access(struct g_provider *pp, int acr, int acw, int ace)
 {
-	struct g_raid_volume *vol;
+	struct g_raid_volume *vol, *vol1;
 	struct g_raid_softc *sc;
-	int dcr, dcw, dce;
+	int dcr, dcw, dce, opens, error = 0;
 
 	g_topology_assert();
 	G_RAID_DEBUG(2, "Access request for %s: r%dw%de%d.", pp->name, acr,
@@ -1460,14 +1460,35 @@ g_raid_access(struct g_provider *pp, int
 
 	g_topology_unlock();
 	sx_xlock(&sc->sc_lock);
+	/* Deny new opens while dying. */
+	if (sc->sc_stopping != 0 && (acr > 0 || acw > 0 || ace > 0)) {
+		error = ENXIO;
+		goto out;
+	}
 //	if (dcw == 0 && !vol->v_idle)
 //		g_raid_idle(vol, dcw);
 	vol->v_provider_open += acr + acw + ace;
+	/* Handle delayed node destruction. */
+	if (sc->sc_stopping == G_RAID_DESTROY_DELAYED &&
+	    vol->v_provider_open == 0) {
+		/* Count open volumes. */
+		opens = 0;
+		TAILQ_FOREACH(vol1, &sc->sc_volumes, v_next) {
+			if (vol1->v_provider_open != 0)
+				opens++;
+		}
+		if (opens == 0) {
+			sc->sc_stopping = G_RAID_DESTROY_HARD;
+			g_raid_event_send(sc, 0, 0);	/* Wake up worker. */
+		}
+	}
+	/* Handle open volume destruction. */
 	if (vol->v_stopping && vol->v_provider_open == 0)
 		g_raid_destroy_volume(vol);
+out:
 	sx_xunlock(&sc->sc_lock);
 	g_topology_lock();
-	return (0);
+	return (error);
 }
 
 struct g_raid_softc *
@@ -1612,7 +1633,7 @@ g_raid_destroy_node(struct g_raid_softc 
 	struct g_raid_disk *disk, *tmpd;
 	int error = 0;
 
-	sc->sc_stopping = 1;
+	sc->sc_stopping = G_RAID_DESTROY_HARD;
 	TAILQ_FOREACH_SAFE(vol, &sc->sc_volumes, v_next, tmpv) {
 		if (g_raid_destroy_volume(vol))
 			error = EBUSY;
@@ -1698,7 +1719,7 @@ g_raid_destroy_volume(struct g_raid_volu
 	}
 	G_RAID_DEBUG(2, "Volume %s destroyed.", vol->v_name);
 	free(vol, M_RAID);
-	if (sc->sc_stopping)
+	if (sc->sc_stopping == G_RAID_DESTROY_HARD)
 		g_raid_event_send(sc, 0, 0);	/* Wake up worker. */
 	return (0);
 }
@@ -1760,7 +1781,7 @@ g_raid_destroy(struct g_raid_softc *sc, 
 			G_RAID_DEBUG(1,
 			    "Node %s will be destroyed on last close.",
 			    sc->sc_name);
-//			sc->sc_stopping = 1;
+			sc->sc_stopping = G_RAID_DESTROY_DELAYED;
 			return (EBUSY);
 		case G_RAID_DESTROY_HARD:
 			G_RAID_DEBUG(1,
@@ -1770,7 +1791,7 @@ g_raid_destroy(struct g_raid_softc *sc, 
 	}
 
 	/* Mark node for destruction. */
-	sc->sc_stopping = 1;
+	sc->sc_stopping = G_RAID_DESTROY_HARD;
 	/* Wake up worker to let it selfdestruct. */
 	g_raid_event_send(sc, 0, 0);
 	/* Sleep until node destroyed. */
@@ -1970,7 +1991,6 @@ g_raid_dumpconf(struct sbuf *sb, const c
 	}
 }
 
-#if 0
 static void
 g_raid_shutdown_pre_sync(void *arg, int howto)
 {
@@ -1996,16 +2016,15 @@ g_raid_shutdown_pre_sync(void *arg, int 
 	g_topology_unlock();
 	PICKUP_GIANT();
 }
-#endif
 
 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_DEBUG(0, "Warning! Cannot register shutdown event.");
+	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_DEBUG(0, "Warning! Cannot register shutdown event.");
 	g_raid_started = 1;
 }
 
@@ -2013,8 +2032,8 @@ 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_pre_sync != NULL)
+		EVENTHANDLER_DEREGISTER(shutdown_pre_sync, g_raid_pre_sync);
 	g_raid_started = 0;
 }