Index: g_concat.c
===================================================================
RCS file: /usr/repo/src/sys/geom/concat/g_concat.c,v
retrieving revision 1.23
diff -u -p -r1.23 g_concat.c
--- g_concat.c	27 Feb 2005 23:07:46 -0000	1.23
+++ g_concat.c	3 Apr 2005 14:22:21 -0000
@@ -213,6 +213,7 @@ g_concat_access(struct g_provider *pp, i
 static void
 g_concat_start(struct bio *bp)
 {
+	struct bio_queue_head queue;
 	struct g_concat_softc *sc;
 	struct g_concat_disk *disk;
 	struct g_provider *pp;
@@ -250,6 +251,7 @@ g_concat_start(struct bio *bp)
 	addr = bp->bio_data;
 	end = offset + length;
 
+	bioq_init(&queue);
 	for (no = 0; no < sc->sc_ndisks; no++) {
 		disk = &sc->sc_disks[no];
 		if (disk->d_end <= offset)
@@ -264,10 +266,18 @@ g_concat_start(struct bio *bp)
 
 		cbp = g_clone_bio(bp);
 		if (cbp == NULL) {
+			G_CONCAT_DEBUG(0, "Cannot allocate bio!");
+			for (cbp = bioq_first(&queue); cbp != NULL;
+			    cbp = bioq_first(&queue)) {
+				bioq_remove(&queue, cbp);
+				g_destroy_bio(cbp);
+			}
 			if (bp->bio_error == 0)
 				bp->bio_error = ENOMEM;
+			g_io_deliver(bp, bp->bio_error);
 			return;
 		}
+		bioq_insert_tail(&queue, cbp);
 		/*
 		 * Fill in the component buf structure.
 		 */
@@ -277,16 +287,21 @@ g_concat_start(struct bio *bp)
 		addr += len;
 		cbp->bio_length = len;
 		cbp->bio_to = disk->d_consumer->provider;
-		G_CONCAT_LOGREQ(cbp, "Sending request.");
-		g_io_request(cbp, disk->d_consumer);
+		cbp->bio_caller1 = disk;
 
 		if (length == 0)
 			break;
 	}
-
 	KASSERT(length == 0,
 	    ("Length is still greater than 0 (class=%s, name=%s).",
 	    bp->bio_to->geom->class->name, bp->bio_to->geom->name));
+	for (cbp = bioq_first(&queue); cbp != NULL; cbp = bioq_first(&queue)) {
+		bioq_remove(&queue, cbp);
+		G_CONCAT_LOGREQ(cbp, "Sending request.");
+		disk = cbp->bio_caller1;
+		cbp->bio_caller1 = NULL;
+		g_io_request(cbp, disk->d_consumer);
+	}
 }
 
 static void