--- g_cache.c	Tue Jul 11 05:55:45 2006
+++ sys/geom/cache/g_cache.c	Tue Jul 11 06:47:28 2006
@@ -101,6 +101,33 @@
 #define	OFF2BNO(off, sc)	((off) >> (sc)->sc_bshift)
 #define	BNO2OFF(bno, sc)	((bno) << (sc)->sc_bshift)
 
+static int
+g_cache_in_bucket(struct g_cache_softc *sc, struct g_cache_desc *dp)
+{
+	struct g_cache_desc *dp2;
+	int i;
+
+	for (i = 0; i < G_CACHE_BUCKETS; i++) {
+		LIST_FOREACH(dp2, &sc->sc_desclist[i], d_next) {
+			if (dp2 == dp)
+				return (1);
+		}
+	}
+	return (0);
+}
+
+static int
+g_cache_used(struct g_cache_softc *sc, struct g_cache_desc *dp)
+{
+	struct g_cache_desc *dp2;
+
+	TAILQ_FOREACH(dp2, &sc->sc_usedlist, d_used) {
+		KASSERT((dp2->d_flags & D_FLAG_USED), ("%s: dp2=%p no used flag", __func__, dp2));
+		if (dp2 == dp)
+			return (1);
+	}
+	return (0);
+}
 
 static struct g_cache_desc *
 g_cache_alloc(struct g_cache_softc *sc)
@@ -111,9 +138,16 @@
 
 	if (!TAILQ_EMPTY(&sc->sc_usedlist)) {
 		dp = TAILQ_FIRST(&sc->sc_usedlist);
+		if (!g_cache_used(sc, dp))
+			panic("%s: dp=%p not on used list", __func__, dp);
+		KASSERT((dp->d_flags & D_FLAG_USED), ("%s: dp=%p no used flag", __func__, dp));
 		TAILQ_REMOVE(&sc->sc_usedlist, dp, d_used);
 		sc->sc_nused--;
+		KASSERT(sc->sc_nused >= 0, ("%s: sc_nused < 0", __func__));
+		KASSERT(dp->d_flags == D_FLAG_USED, ("%s: dp=%p more flags 0x%x", __func__, dp, dp->d_flags));
 		dp->d_flags = 0;
+		if (!g_cache_in_bucket(sc, dp))
+			panic("%s: dp=%p not in bucket", __func__, dp);
 		LIST_REMOVE(dp, d_next);
 		return (dp);
 	}
@@ -124,7 +158,7 @@
 	dp = malloc(sizeof(*dp), M_GCACHE, M_NOWAIT | M_ZERO);
 	if (dp == NULL)
 		return (NULL);
-	dp->d_data = uma_zalloc(sc->sc_zone, M_NOWAIT);
+	dp->d_data = malloc(sc->sc_bsize, M_GCACHE, M_NOWAIT);
 	if (dp->d_data == NULL) {
 		free(dp, M_GCACHE);
 		return (NULL);
@@ -139,7 +173,11 @@
 
 	mtx_assert(&sc->sc_mtx, MA_OWNED);
 
-	uma_zfree(sc->sc_zone, dp->d_data);
+	if (g_cache_in_bucket(sc, dp))
+		panic("%s: dp=%p still in bucket", __func__, dp);
+	if (g_cache_used(sc, dp))
+		panic("%s: dp=%p still on used list", __func__, dp);
+	free(dp->d_data, M_GCACHE);
 	free(dp, M_GCACHE);
 	sc->sc_nent--;
 }
@@ -156,8 +194,14 @@
 	while (sc->sc_nused > n) {
 		KASSERT(!TAILQ_EMPTY(&sc->sc_usedlist), ("used list empty"));
 		dp = TAILQ_FIRST(&sc->sc_usedlist);
+		if (!g_cache_used(sc, dp))
+			panic("%s: dp=%p not on used list", __func__, dp);
+		KASSERT((dp->d_flags & D_FLAG_USED), ("%s: dp=%p no used flag", __func__, dp));
 		TAILQ_REMOVE(&sc->sc_usedlist, dp, d_used);
 		sc->sc_nused--;
+		KASSERT(sc->sc_nused >= 0, ("%s: sc_nused < 0", __func__));
+		if (!g_cache_in_bucket(sc, dp))
+			panic("%s: dp=%p not in bucket", __func__, dp);
 		LIST_REMOVE(dp, d_next);
 		g_cache_free(sc, dp);
 	}
@@ -194,8 +238,10 @@
 
 	if (dp->d_flags & D_FLAG_USED) {
 		TAILQ_REMOVE(&sc->sc_usedlist, dp, d_used);
+		KASSERT(!(dp->d_flags & D_FLAG_INVALID), ("%s: dp=%p has invalid flag", __func__, dp));
 		TAILQ_INSERT_TAIL(&sc->sc_usedlist, dp, d_used);
 	} else if (OFF2BNO(off + len, sc) > dp->d_bno) {
+		KASSERT(!(dp->d_flags & D_FLAG_INVALID), ("%s: dp=%p has invalid flag", __func__, dp));
 		TAILQ_INSERT_TAIL(&sc->sc_usedlist, dp, d_used);
 		sc->sc_nused++;
 		dp->d_flags |= D_FLAG_USED;
@@ -224,12 +270,18 @@
 	dp->d_biolist = NULL;
 	if (dp->d_flags & D_FLAG_INVALID) {
 		sc->sc_invalid--;
+		KASSERT(sc->sc_invalid >= 0, ("%s: sc_invalid < 0", __func__));
 		g_cache_free(sc, dp);
 	} else if (bp->bio_error) {
+		if (!g_cache_in_bucket(sc, dp))
+			panic("%s: dp=%p not in bucket", __func__, dp);
 		LIST_REMOVE(dp, d_next);
 		if (dp->d_flags & D_FLAG_USED) {
+			if (!g_cache_used(sc, dp))
+				panic("%s: dp=%p not on used list", __func__, dp);
 			TAILQ_REMOVE(&sc->sc_usedlist, dp, d_used);
 			sc->sc_nused--;
+			KASSERT(sc->sc_nused >= 0, ("%s: sc_nused < 0", __func__));
 		}
 		g_cache_free(sc, dp);
 	}
@@ -290,6 +342,8 @@
 	G_CACHE_NEXT_BIO1(bp) = sc;
 	G_CACHE_NEXT_BIO2(bp) = NULL;
 	dp->d_biolist = bp;
+	if (g_cache_in_bucket(sc, dp))
+		panic("%s: dp=%p already in bucket", __func__, dp);
 	LIST_INSERT_HEAD(&sc->sc_desclist[G_CACHE_BUCKET(dp->d_bno)],
 	    dp, d_next);
 	mtx_unlock(&sc->sc_mtx);
@@ -315,10 +369,15 @@
 	lim = OFF2BNO(bp->bio_offset + bp->bio_length - 1, sc);
 	do {
 		if ((dp = g_cache_lookup(sc, bno)) != NULL) {
+			if (!g_cache_in_bucket(sc, dp))
+				panic("%s: dp=%p not in bucket", __func__, dp);
 			LIST_REMOVE(dp, d_next);
 			if (dp->d_flags & D_FLAG_USED) {
+				if (!g_cache_used(sc, dp))
+					panic("%s: dp=%p not on used list", __func__, dp);
 				TAILQ_REMOVE(&sc->sc_usedlist, dp, d_used);
 				sc->sc_nused--;
+				KASSERT(sc->sc_nused >= 0, ("%s: sc_nused < 0", __func__));
 			}
 			if (dp->d_biolist == NULL)
 				g_cache_free(sc, dp);
@@ -411,6 +470,9 @@
 			    dp->d_biolist != NULL ||
 			    time_uptime - dp->d_atime < g_cache_idletime)
 				continue;
+			if (g_cache_used(sc, dp))
+				panic("%s: dp=%p already on used list", __func__, dp);
+			KASSERT(!(dp->d_flags & D_FLAG_INVALID), ("%s: dp=%p has invalid flag", __func__, dp));
 			TAILQ_INSERT_TAIL(&sc->sc_usedlist, dp, d_used);
 			sc->sc_nused++;
 			dp->d_flags |= D_FLAG_USED;
@@ -509,8 +571,6 @@
 	sc->sc_type = type;
 	sc->sc_bshift = bshift;
 	sc->sc_bsize = 1 << bshift;
-	sc->sc_zone = uma_zcreate("gcache", sc->sc_bsize, NULL, NULL, NULL, NULL,
-	    UMA_ALIGN_PTR, 0);
 	mtx_init(&sc->sc_mtx, "GEOM CACHE mutex", NULL, MTX_DEF);
 	for (i = 0; i < G_CACHE_BUCKETS; i++)
 		LIST_INIT(&sc->sc_desclist[i]);
@@ -572,7 +632,7 @@
 {
 	struct g_geom *gp;
 	struct g_provider *pp;
-	struct g_cache_desc *dp, *dp2;
+	struct g_cache_desc *dp;
 	int i;
 
 	g_topology_assert();
@@ -595,16 +655,13 @@
 	callout_drain(&sc->sc_callout);
 	mtx_lock(&sc->sc_mtx);
 	for (i = 0; i < G_CACHE_BUCKETS; i++) {
-		dp = LIST_FIRST(&sc->sc_desclist[i]);
-		while (dp != NULL) {
-			dp2 = LIST_NEXT(dp, d_next);
+		while ((dp = LIST_FIRST(&sc->sc_desclist[i])) != NULL) {
+			LIST_REMOVE(dp, d_next);
 			g_cache_free(sc, dp);
-			dp = dp2;
 		}
 	}
 	mtx_unlock(&sc->sc_mtx);
 	mtx_destroy(&sc->sc_mtx);
-	uma_zdestroy(sc->sc_zone);
 	g_free(sc);
 	gp->softc = NULL;
 	g_wither_geom(gp, ENXIO);