diff --git a/sys/arch/xen/xen/xbd.c b/sys/arch/xen/xen/xbd.c
index cd1efbd14678..c919d63dbdf6 100644
--- a/sys/arch/xen/xen/xbd.c
+++ b/sys/arch/xen/xen/xbd.c
@@ -1,4 +1,4 @@
-/* $NetBSD: xbd.c,v 1.26 2005/12/13 08:24:30 yamt Exp $ */
+/* $NetBSD: xbd.c,v 1.27 2005/12/26 10:36:47 yamt Exp $ */
 
 /*
  *
@@ -33,7 +33,7 @@
 
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xbd.c,v 1.26 2005/12/13 08:24:30 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xbd.c,v 1.27 2005/12/26 10:36:47 yamt Exp $");
 
 #include "xbd.h"
 #include "rnd.h"
@@ -1522,7 +1522,7 @@ xbdioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *l)
 {
 	struct	xbd_softc *xs;
 	struct	dk_softc *dksc;
-	int	ret;
+	int	error;
 	struct	disk *dk;
 
 	DPRINTF_FOLLOW(("xbdioctl(%d, %08lx, %p, %d, %p)\n",
@@ -1531,13 +1531,18 @@ xbdioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct lwp *l)
 	dksc = &xs->sc_dksc;
 	dk = &dksc->sc_dkdev;
 
+	KASSERT(bufq == dksc->sc_bufq);
+
 	switch (cmd) {
+	case DIOCSSTRATEGY:
+		error = EOPNOTSUPP;
+		break;
 	default:
-		ret = dk_ioctl(xs->sc_di, dksc, dev, cmd, data, flag, l);
+		error = dk_ioctl(xs->sc_di, dksc, dev, cmd, data, flag, l);
 		break;
 	}
 
-	return ret;
+	return error;
 }
 
 int
diff --git a/sys/dev/ata/wd.c b/sys/dev/ata/wd.c
index 644c1750939f..a85edaac5a80 100644
--- a/sys/dev/ata/wd.c
+++ b/sys/dev/ata/wd.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: wd.c,v 1.314 2005/12/11 12:21:14 christos Exp $ */
+/*	$NetBSD: wd.c,v 1.315 2005/12/26 10:36:47 yamt Exp $ */
 
 /*
  * Copyright (c) 1998, 2001 Manuel Bouyer.  All rights reserved.
@@ -66,7 +66,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: wd.c,v 1.314 2005/12/11 12:21:14 christos Exp $");
+__KERNEL_RCSID(0, "$NetBSD: wd.c,v 1.315 2005/12/26 10:36:47 yamt Exp $");
 
 #ifndef ATADEBUG
 #define ATADEBUG
@@ -1440,6 +1440,47 @@ bad:
 		return (dkwedge_list(&wd->sc_dk, dkwl, l));
 	    }
 
+	case DIOCGSTRATEGY:
+	    {
+		struct disk_strategy *dks = (void *)addr;
+
+		s = splbio();
+		strlcpy(dks->dks_name, bufq_getstrategyname(wd->sc_q),
+		    sizeof(dks->dks_name));
+		splx(s);
+		dks->dks_paramlen = 0;
+
+		return 0;
+	    }
+	
+	case DIOCSSTRATEGY:
+	    {
+		struct disk_strategy *dks = (void *)addr;
+		struct bufq_state *new;
+		struct bufq_state *old;
+
+		if ((flag & FWRITE) == 0) {
+			return EBADF;
+		}
+		if (dks->dks_param != NULL) {
+			return EINVAL;
+		}
+		dks->dks_name[sizeof(dks->dks_name) - 1] = 0; /* ensure term */
+		error = bufq_alloc(&new, dks->dks_name,
+		    BUFQ_EXACT|BUFQ_SORT_RAWBLOCK);
+		if (error) {
+			return error;
+		}
+		s = splbio();
+		old = wd->sc_q;
+		bufq_move(new, old);
+		wd->sc_q = new;
+		splx(s);
+		bufq_free(old);
+
+		return 0;
+	    }
+
 	default:
 		return ENOTTY;
 	}
diff --git a/sys/dev/dksubr.c b/sys/dev/dksubr.c
index bb63a42cb66c..fc4b3e3beb80 100644
--- a/sys/dev/dksubr.c
+++ b/sys/dev/dksubr.c
@@ -1,4 +1,4 @@
-/* $NetBSD: dksubr.c,v 1.20 2005/12/11 23:42:33 rpaulo Exp $ */
+/* $NetBSD: dksubr.c,v 1.21 2005/12/26 10:36:47 yamt Exp $ */
 
 /*-
  * Copyright (c) 1996, 1997, 1998, 1999, 2002 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: dksubr.c,v 1.20 2005/12/11 23:42:33 rpaulo Exp $");
+__KERNEL_RCSID(0, "$NetBSD: dksubr.c,v 1.21 2005/12/26 10:36:47 yamt Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -451,6 +451,49 @@ dk_ioctl(struct dk_intf *di, struct dk_softc *dksc, dev_t dev,
 		return (dkwedge_list(&dksc->sc_dkdev, dkwl, l));
 	    }
 
+	case DIOCGSTRATEGY:
+	    {
+		struct disk_strategy *dks = (void *)data;
+		int s;
+
+		s = splbio();
+		strlcpy(dks->dks_name, bufq_getstrategyname(dksc->sc_bufq),
+		    sizeof(dks->dks_name));
+		splx(s);
+		dks->dks_paramlen = 0;
+
+		return 0;
+	    }
+	
+	case DIOCSSTRATEGY:
+	    {
+		struct disk_strategy *dks = (void *)data;
+		struct bufq_state *new;
+		struct bufq_state *old;
+		int s;
+
+		if ((flag & FWRITE) == 0) {
+			return EBADF;
+		}
+		if (dks->dks_param != NULL) {
+			return EINVAL;
+		}
+		dks->dks_name[sizeof(dks->dks_name) - 1] = 0; /* ensure term */
+		error = bufq_alloc(&new, dks->dks_name,
+		    BUFQ_EXACT|BUFQ_SORT_RAWBLOCK);
+		if (error) {
+			return error;
+		}
+		s = splbio();
+		old = dksc->sc_bufq;
+		bufq_move(new, old);
+		dksc->sc_bufq = new;
+		splx(s);
+		bufq_free(old);
+
+		return 0;
+	    }
+
 	default:
 		error = ENOTTY;
 	}
diff --git a/sys/kern/subr_bufq.c b/sys/kern/subr_bufq.c
index a6ea1c1ba9c9..82917a292f75 100644
--- a/sys/kern/subr_bufq.c
+++ b/sys/kern/subr_bufq.c
@@ -1,4 +1,4 @@
-/*	$NetBSD: subr_bufq.c,v 1.11 2005/12/26 10:00:34 yamt Exp $	*/
+/*	$NetBSD: subr_bufq.c,v 1.12 2005/12/26 10:36:47 yamt Exp $	*/
 /*	NetBSD: subr_disk.c,v 1.70 2005/08/20 12:00:01 yamt Exp $	*/
 
 /*-
@@ -75,7 +75,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_bufq.c,v 1.11 2005/12/26 10:00:34 yamt Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_bufq.c,v 1.12 2005/12/26 10:36:47 yamt Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -214,7 +214,6 @@ bufq_free(struct bufq_state *bufq)
 	free(bufq, M_DEVBUF);
 }
 
-#if 0
 /*
  * get a strategy identifier of a buffer queue.
  */
@@ -237,7 +236,6 @@ bufq_move(struct bufq_state *dst, struct bufq_state *src)
 		BUFQ_PUT(dst, bp);
 	}
 }
-#endif
 
 static int
 docopy(char *buf, size_t *bufoffp, size_t buflen,
diff --git a/sys/sys/disk.h b/sys/sys/disk.h
index ce0bd444d18f..394cf010e68d 100644
--- a/sys/sys/disk.h
+++ b/sys/sys/disk.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: disk.h,v 1.31 2005/12/11 12:25:20 christos Exp $	*/
+/*	$NetBSD: disk.h,v 1.32 2005/12/26 10:36:47 yamt Exp $	*/
 
 /*-
  * Copyright (c) 1996, 1997, 2004 The NetBSD Foundation, Inc.
@@ -310,6 +310,13 @@ struct disk_badsecinfo {
 	caddr_t		dbsi_buffer;	/* region to copy disk_badsectors to */
 };
 
+#define	DK_STRATEGYNAMELEN	32
+struct disk_strategy {
+	char dks_name[DK_STRATEGYNAMELEN]; /* name of strategy */
+	char *dks_param;		/* notyet; should be NULL */
+	size_t dks_paramlen;		/* notyet; should be 0 */
+};
+
 #ifdef _KERNEL
 extern	int disk_count;			/* number of disks in global disklist */
 
diff --git a/sys/sys/dkio.h b/sys/sys/dkio.h
index 107d4f9a841e..f07f40ba5baf 100644
--- a/sys/sys/dkio.h
+++ b/sys/sys/dkio.h
@@ -1,4 +1,4 @@
-/*	$NetBSD: dkio.h,v 1.11 2005/12/11 12:25:20 christos Exp $	*/
+/*	$NetBSD: dkio.h,v 1.12 2005/12/26 10:36:47 yamt Exp $	*/
 
 /*
  * Copyright (c) 1987, 1988, 1993
@@ -94,4 +94,8 @@
 #define	DIOCDWEDGE	_IOW('d', 123, struct dkwedge_info)  /* del wedge */
 #define	DIOCLWEDGES	_IOWR('d', 124, struct dkwedge_list) /* list wedges */
 
+		/* disk buffer queue strategy */
+#define	DIOCGSTRATEGY	_IOR('d', 125, struct disk_strategy)
+#define	DIOCSSTRATEGY	_IOW('d', 126, struct disk_strategy)
+
 #endif /* _SYS_DKIO_H_ */