diff --git a/stand/common/disk.c b/stand/common/disk.c
index 4cb57d466a5e..57cb2065a7a6 100644
--- a/stand/common/disk.c
+++ b/stand/common/disk.c
@@ -86,7 +86,7 @@ ptblread(void *d, void *buf, size_t blocks, uint64_t offset)
 	struct open_disk *od;
 
 	dev = (struct disk_devdesc *)d;
-	od = (struct open_disk *)dev->d_opendata;
+	od = (struct open_disk *)dev->dd.d_opendata;
 
 	/*
 	 * The strategy function assumes the offset is in units of 512 byte
@@ -98,7 +98,7 @@ ptblread(void *d, void *buf, size_t blocks, uint64_t offset)
 	 * As the GPT backup partition is located at the end of the disk,
 	 * to avoid reading past disk end, flag bcache not to use RA.
 	 */
-	return (dev->d_dev->dv_strategy(dev, F_READ | F_NORA, offset,
+	return (dev->dd.d_dev->dv_strategy(dev, F_READ | F_NORA, offset,
 	    blocks * od->sectorsize, (char *)buf, NULL));
 }
 
@@ -114,7 +114,7 @@ ptable_print(void *arg, const char *pname, const struct ptable_entry *part)
 	int res;
 
 	pa = (struct print_args *)arg;
-	od = (struct open_disk *)pa->dev->d_opendata;
+	od = (struct open_disk *)pa->dev->dd.d_opendata;
 	sprintf(line, "  %s%s: %s", pa->prefix, pname,
 	    parttype2str(part->type));
 	if (pa->verbose)
@@ -127,8 +127,8 @@ ptable_print(void *arg, const char *pname, const struct ptable_entry *part)
 	res = 0;
 	if (part->type == PART_FREEBSD) {
 		/* Open slice with BSD label */
-		dev.d_dev = pa->dev->d_dev;
-		dev.d_unit = pa->dev->d_unit;
+		dev.dd.d_dev = pa->dev->dd.d_dev;
+		dev.dd.d_unit = pa->dev->dd.d_unit;
 		dev.d_slice = part->index;
 		dev.d_partition = -1;
 		if (disk_open(&dev, part->end - part->start + 1,
@@ -158,7 +158,7 @@ disk_print(struct disk_devdesc *dev, char *prefix, int verbose)
 	struct print_args pa;
 
 	/* Disk should be opened */
-	od = (struct open_disk *)dev->d_opendata;
+	od = (struct open_disk *)dev->dd.d_opendata;
 	pa.dev = dev;
 	pa.prefix = prefix;
 	pa.verbose = verbose;
@@ -171,8 +171,8 @@ disk_read(struct disk_devdesc *dev, void *buf, uint64_t offset, u_int blocks)
 	struct open_disk *od;
 	int ret;
 
-	od = (struct open_disk *)dev->d_opendata;
-	ret = dev->d_dev->dv_strategy(dev, F_READ, dev->d_offset + offset,
+	od = (struct open_disk *)dev->dd.d_opendata;
+	ret = dev->dd.d_dev->dv_strategy(dev, F_READ, dev->d_offset + offset,
 	    blocks * od->sectorsize, buf, NULL);
 
 	return (ret);
@@ -184,8 +184,8 @@ disk_write(struct disk_devdesc *dev, void *buf, uint64_t offset, u_int blocks)
 	struct open_disk *od;
 	int ret;
 
-	od = (struct open_disk *)dev->d_opendata;
-	ret = dev->d_dev->dv_strategy(dev, F_WRITE, dev->d_offset + offset,
+	od = (struct open_disk *)dev->dd.d_opendata;
+	ret = dev->dd.d_dev->dv_strategy(dev, F_WRITE, dev->d_offset + offset,
 	    blocks * od->sectorsize, buf, NULL);
 
 	return (ret);
@@ -194,7 +194,7 @@ disk_write(struct disk_devdesc *dev, void *buf, uint64_t offset, u_int blocks)
 int
 disk_ioctl(struct disk_devdesc *dev, u_long cmd, void *data)
 {
-	struct open_disk *od = dev->d_opendata;
+	struct open_disk *od = dev->dd.d_opendata;
 
 	if (od == NULL)
 		return (ENOTTY);
@@ -238,7 +238,7 @@ disk_open(struct disk_devdesc *dev, uint64_t mediasize, u_int sectorsize)
 		DEBUG("no memory");
 		return (ENOMEM);
 	}
-	dev->d_opendata = od;
+	dev->dd.d_opendata = od;
 	od->entrysize = 0;
 	od->mediasize = mediasize;
 	od->sectorsize = sectorsize;
@@ -348,7 +348,7 @@ disk_close(struct disk_devdesc *dev)
 {
 	struct open_disk *od;
 
-	od = (struct open_disk *)dev->d_opendata;
+	od = (struct open_disk *)dev->dd.d_opendata;
 	DEBUG("%s closed => %p", disk_fmtdev(dev), od);
 	ptable_close(od->table);
 	free(od);
@@ -361,7 +361,7 @@ disk_fmtdev(struct disk_devdesc *dev)
 	static char buf[128];
 	char *cp;
 
-	cp = buf + sprintf(buf, "%s%d", dev->d_dev->dv_name, dev->d_unit);
+	cp = buf + sprintf(buf, "%s%d", dev->dd.d_dev->dv_name, dev->dd.d_unit);
 	if (dev->d_slice >= 0) {
 #ifdef LOADER_GPT_SUPPORT
 		if (dev->d_partition == 255) {
@@ -423,7 +423,7 @@ disk_parsedev(struct disk_devdesc *dev, const char *devspec, const char **path)
 
 	if (*cp != '\0' && *cp != ':')
 		return (EINVAL);
-	dev->d_unit = unit;
+	dev->dd.d_unit = unit;
 	dev->d_slice = slice;
 	dev->d_partition = partition;
 	if (path != NULL)
diff --git a/stand/common/disk.h b/stand/common/disk.h
index 3ffe2871a9e5..8396c2702a39 100644
--- a/stand/common/disk.h
+++ b/stand/common/disk.h
@@ -83,10 +83,7 @@
 
 /* Note: Must match the 'struct devdesc' in stand.h */
 struct disk_devdesc {
-	struct devsw	*d_dev;
-	int		d_type;
-	int		d_unit;
-	void		*d_opendata;
+	struct devdesc	dd;
 	int		d_slice;
 	int		d_partition;
 	uint64_t	d_offset;
diff --git a/stand/efi/libefi/efipart.c b/stand/efi/libefi/efipart.c
index 5245e8bd0871..6838693a8646 100644
--- a/stand/efi/libefi/efipart.c
+++ b/stand/efi/libefi/efipart.c
@@ -744,8 +744,8 @@ efipart_print_common(struct devsw *dev, pdinfo_list_t *pdlist, int verbose)
 				continue;
 
 			pd->pd_blkio = blkio;
-			pd_dev.d_dev = dev;
-			pd_dev.d_unit = pd->pd_unit;
+			pd_dev.dd.d_dev = dev;
+			pd_dev.dd.d_unit = pd->pd_unit;
 			pd_dev.d_slice = -1;
 			pd_dev.d_partition = -1;
 			ret = disk_open(&pd_dev, blkio->Media->BlockSize *
@@ -820,7 +820,7 @@ efipart_open(struct open_file *f, ...)
 	if (pd->pd_bcache == NULL)
 		pd->pd_bcache = bcache_allocate();
 
-	if (dev->d_dev->dv_type == DEVT_DISK) {
+	if (dev->dd.d_dev->dv_type == DEVT_DISK) {
 		int rc;
 
 		rc = disk_open(dev,
@@ -859,7 +859,7 @@ efipart_close(struct open_file *f)
 		bcache_free(pd->pd_bcache);
 		pd->pd_bcache = NULL;
 	}
-	if (dev->d_dev->dv_type == DEVT_DISK)
+	if (dev->dd.d_dev->dv_type == DEVT_DISK)
 		return (disk_close(dev));
 	return (0);
 }
@@ -879,7 +879,7 @@ efipart_ioctl(struct open_file *f, u_long cmd, void *data)
 	if (pd == NULL)
 		return (EINVAL);
 
-	if (dev->d_dev->dv_type == DEVT_DISK) {
+	if (dev->dd.d_dev->dv_type == DEVT_DISK) {
 		rc = disk_ioctl(dev, cmd, data);
 		if (rc != ENOTTY)
 			return (rc);
@@ -966,7 +966,7 @@ efipart_strategy(void *devdata, int rw, daddr_t blk, size_t size,
 	bcd.dv_devdata = devdata;
 	bcd.dv_cache = pd->pd_bcache;
 
-	if (dev->d_dev->dv_type == DEVT_DISK) {
+	if (dev->dd.d_dev->dv_type == DEVT_DISK) {
 		daddr_t offset;
 
 		offset = dev->d_offset * pd->pd_blkio->Media->BlockSize;
@@ -1010,7 +1010,7 @@ efipart_realstrategy(void *devdata, int rw, daddr_t blk, size_t size,
 	 * partition.
 	 */
 	disk_blocks = 0;
-	if (dev->d_dev->dv_type == DEVT_DISK) {
+	if (dev->dd.d_dev->dv_type == DEVT_DISK) {
 		if (disk_ioctl(dev, DIOCGMEDIASIZE, &disk_blocks) == 0) {
 			/* DIOCGMEDIASIZE does return bytes. */
 			disk_blocks /= blkio->Media->BlockSize;
diff --git a/stand/efi/libefi/efizfs.c b/stand/efi/libefi/efizfs.c
index 58a0d6670adb..3d5400f43ee9 100644
--- a/stand/efi/libefi/efizfs.c
+++ b/stand/efi/libefi/efizfs.c
@@ -29,8 +29,7 @@
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
-#include <sys/disk.h>
-#include <stdint.h>
+#include <stand.h>
 
 #ifdef EFI_ZFS_BOOT
 #include <libzfs.h>
diff --git a/stand/efi/loader/main.c b/stand/efi/loader/main.c
index d03a56e6741f..ffa6934ba517 100644
--- a/stand/efi/loader/main.c
+++ b/stand/efi/loader/main.c
@@ -201,9 +201,9 @@ find_currdev(EFI_LOADED_IMAGE *img)
 	if (pool_guid != 0) {
 		struct zfs_devdesc currdev;
 
-		currdev.d_dev = &zfs_dev;
-		currdev.d_unit = 0;
-		currdev.d_type = currdev.d_dev->dv_type;
+		currdev.dd.d_dev = &zfs_dev;
+		currdev.dd.d_unit = 0;
+		currdev.dd.d_type = currdev.dd.d_dev->dv_type;
 		currdev.pool_guid = pool_guid;
 		currdev.root_guid = 0;
 		devname = efi_fmtdev(&currdev);
@@ -222,9 +222,9 @@ find_currdev(EFI_LOADED_IMAGE *img)
 	STAILQ_FOREACH(dp, pdi_list, pd_link) {
 		struct disk_devdesc currdev;
 
-		currdev.d_dev = &efipart_hddev;
-		currdev.d_type = currdev.d_dev->dv_type;
-		currdev.d_unit = dp->pd_unit;
+		currdev.dd.d_dev = &efipart_hddev;
+		currdev.dd.d_type = currdev.dd.d_dev->dv_type;
+		currdev.dd.d_unit = dp->pd_unit;
 		currdev.d_slice = -1;
 		currdev.d_partition = -1;
 
diff --git a/stand/i386/libi386/bioscd.c b/stand/i386/libi386/bioscd.c
index 2e8fc3b11b49..a451f16da64e 100644
--- a/stand/i386/libi386/bioscd.c
+++ b/stand/i386/libi386/bioscd.c
@@ -90,7 +90,7 @@ static struct bcinfo {
 } bcinfo [MAXBCDEV];
 static int nbcinfo = 0;
 
-#define	BC(dev)	(bcinfo[(dev)->d_unit])
+#define	BC(dev)	(bcinfo[(dev)->dd.d_unit])
 
 static int	bc_read(int unit, daddr_t dblk, int blks, caddr_t dest);
 static int	bc_init(void);
@@ -211,7 +211,7 @@ bc_open(struct open_file *f, ...)
 	va_start(ap, f);
 	dev = va_arg(ap, struct i386_devdesc *);
 	va_end(ap);
-	if (dev->d_unit >= nbcinfo) {
+	if (dev->dd.d_unit >= nbcinfo) {
 		DEBUG("attempt to open nonexistent disk");
 		return(ENXIO);
 	}
@@ -271,7 +271,7 @@ bc_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size,
 	if ((rw & F_MASK) != F_READ)
 		return(EROFS);
 	dev = (struct i386_devdesc *)devdata;
-	unit = dev->d_unit;
+	unit = dev->dd.d_unit;
 	blks = size / BIOSCD_SECSIZE;
 	if (dblk % (BIOSCD_SECSIZE / DEV_BSIZE) != 0)
 		return (EINVAL);
@@ -427,7 +427,7 @@ bc_getdev(struct i386_devdesc *dev)
     int major;
     int rootdev;
 
-    unit = dev->d_unit;
+    unit = dev->dd.d_unit;
     biosdev = bc_unit2bios(unit);
     DEBUG("unit %d BIOS device %d", unit, biosdev);
     if (biosdev == -1)				/* not a BIOS device */
diff --git a/stand/i386/libi386/biosdisk.c b/stand/i386/libi386/biosdisk.c
index 264451484b06..9adbe9d16b2a 100644
--- a/stand/i386/libi386/biosdisk.c
+++ b/stand/i386/libi386/biosdisk.c
@@ -120,7 +120,7 @@ static struct bdinfo
 } bdinfo [MAXBDDEV];
 static int nbdinfo = 0;
 
-#define	BD(dev)		(bdinfo[(dev)->d_unit])
+#define	BD(dev)		(bdinfo[(dev)->dd.d_unit])
 
 static int bd_read(struct disk_devdesc *dev, daddr_t dblk, int blks,
     caddr_t dest);
@@ -349,8 +349,8 @@ bd_print(int verbose)
 		    bdinfo[i].bd_sectorsize);
 		if ((ret = pager_output(line)) != 0)
 			break;
-		dev.d_dev = &biosdisk;
-		dev.d_unit = i;
+		dev.dd.d_dev = &biosdisk;
+		dev.dd.d_unit = i;
 		dev.d_slice = -1;
 		dev.d_partition = -1;
 		if (disk_open(&dev,
@@ -389,7 +389,7 @@ bd_open(struct open_file *f, ...)
 	dev = va_arg(ap, struct disk_devdesc *);
 	va_end(ap);
 
-	if (dev->d_unit < 0 || dev->d_unit >= nbdinfo)
+	if (dev->dd.d_unit < 0 || dev->dd.d_unit >= nbdinfo)
 		return (EIO);
 	BD(dev).bd_open++;
 	if (BD(dev).bd_bcache == NULL)
@@ -402,10 +402,10 @@ bd_open(struct open_file *f, ...)
 	 * During bd_probe() we tested if the mulitplication of bd_sectors
 	 * would overflow so it should be safe to perform here.
 	 */
-	disk.d_dev = dev->d_dev;
-	disk.d_type = dev->d_type;
-	disk.d_unit = dev->d_unit;
-	disk.d_opendata = NULL;
+	disk.dd.d_dev = dev->dd.d_dev;
+	disk.dd.d_type = dev->dd.d_type;
+	disk.dd.d_unit = dev->dd.d_unit;
+	disk.dd.d_opendata = NULL;
 	disk.d_slice = -1;
 	disk.d_partition = -1;
 	disk.d_offset = 0;
@@ -431,7 +431,7 @@ bd_open(struct open_file *f, ...)
 		return (err);
 
 	/* if we already know there is no GELI, skip the rest */
-	if (geli_status[dev->d_unit][dev->d_slice] != ISGELI_UNKNOWN)
+	if (geli_status[dev->dd.d_unit][dev->d_slice] != ISGELI_UNKNOWN)
 		return (err);
 
 	struct dsk dskp;
@@ -440,9 +440,9 @@ bd_open(struct open_file *f, ...)
 	struct pentry *entry;
 	int geli_part = 0;
 
-	dskp.drive = bd_unit2bios(dev->d_unit);
-	dskp.type = dev->d_type;
-	dskp.unit = dev->d_unit;
+	dskp.drive = bd_unit2bios(dev->dd.d_unit);
+	dskp.type = dev->dd.d_type;
+	dskp.unit = dev->dd.d_unit;
 	dskp.slice = dev->d_slice;
 	dskp.part = dev->d_partition;
 	dskp.start = dev->d_offset;
@@ -466,13 +466,13 @@ bd_open(struct open_file *f, ...)
 		dskp.slice = entry->part.index;
 		dskp.start = entry->part.start;
 		if (is_geli(&dskp) == 0) {
-			geli_status[dev->d_unit][dskp.slice] = ISGELI_YES;
+			geli_status[dev->dd.d_unit][dskp.slice] = ISGELI_YES;
 			return (0);
 		}
 		if (geli_taste(bios_read, &dskp,
 		    entry->part.end - entry->part.start) == 0) {
 			if (geli_havekey(&dskp) == 0) {
-				geli_status[dev->d_unit][dskp.slice] = ISGELI_YES;
+				geli_status[dev->dd.d_unit][dskp.slice] = ISGELI_YES;
 				geli_part++;
 				continue;
 			}
@@ -486,18 +486,18 @@ bd_open(struct open_file *f, ...)
 				    &dskp) == 0) {
 				setenv("kern.geom.eli.passphrase", gelipw, 1);
 				bzero(gelipw, sizeof(gelipw));
-				geli_status[dev->d_unit][dskp.slice] = ISGELI_YES;
+				geli_status[dev->dd.d_unit][dskp.slice] = ISGELI_YES;
 				geli_part++;
 				continue;
 			}
 		} else
-			geli_status[dev->d_unit][dskp.slice] = ISGELI_NO;
+			geli_status[dev->dd.d_unit][dskp.slice] = ISGELI_NO;
 	}
 
 	/* none of the partitions on this disk have GELI */
 	if (geli_part == 0) {
 		/* found no GELI */
-		geli_status[dev->d_unit][dev->d_slice] = ISGELI_NO;
+		geli_status[dev->dd.d_unit][dev->d_slice] = ISGELI_NO;
 	}
 #endif /* LOADER_GELI_SUPPORT */
 
@@ -834,10 +834,10 @@ bd_read(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest)
 	char *tmpbuf;
 
 	/* if we already know there is no GELI, skip the rest */
-	if (geli_status[dev->d_unit][dev->d_slice] != ISGELI_YES)
+	if (geli_status[dev->dd.d_unit][dev->d_slice] != ISGELI_YES)
 		return (bd_io(dev, dblk, blks, dest, 0));
 
-	if (geli_status[dev->d_unit][dev->d_slice] == ISGELI_YES) {
+	if (geli_status[dev->dd.d_unit][dev->d_slice] == ISGELI_YES) {
 		/*
 		 * Align reads to DEV_GELIBOOT_BSIZE bytes because partial
 		 * sectors cannot be decrypted. Round the requested LBA down to
@@ -871,9 +871,9 @@ bd_read(struct disk_devdesc *dev, daddr_t dblk, int blks, caddr_t dest)
 		if (err)
 			return (err);
 
-		dskp.drive = bd_unit2bios(dev->d_unit);
-		dskp.type = dev->d_type;
-		dskp.unit = dev->d_unit;
+		dskp.drive = bd_unit2bios(dev->dd.d_unit);
+		dskp.type = dev->dd.d_type;
+		dskp.unit = dev->dd.d_unit;
 		dskp.slice = dev->d_slice;
 		dskp.part = dev->d_partition;
 		dskp.start = dev->d_offset;
@@ -950,8 +950,8 @@ bd_getdev(struct i386_devdesc *d)
     int				i, unit;
 
     dev = (struct disk_devdesc *)d;
-    biosdev = bd_unit2bios(dev->d_unit);
-    DEBUG("unit %d BIOS device %d", dev->d_unit, biosdev);
+    biosdev = bd_unit2bios(dev->dd.d_unit);
+    DEBUG("unit %d BIOS device %d", dev->dd.d_unit, biosdev);
     if (biosdev == -1)				/* not a BIOS device */
 	return(-1);
     if (disk_open(dev, BD(dev).bd_sectors * BD(dev).bd_sectorsize,
@@ -962,7 +962,7 @@ bd_getdev(struct i386_devdesc *d)
 
     if (biosdev < 0x80) {
 	/* floppy (or emulated floppy) or ATAPI device */
-	if (bdinfo[dev->d_unit].bd_type == DT_ATAPI) {
+	if (bdinfo[dev->dd.d_unit].bd_type == DT_ATAPI) {
 	    /* is an ATAPI disk */
 	    major = WFDMAJOR;
 	} else {
@@ -996,9 +996,9 @@ bios_read(void *vdev __unused, void *xpriv, off_t off, void *buf, size_t bytes)
 	struct disk_devdesc dev;
 	struct dsk *priv = xpriv;
 
-	dev.d_dev = &biosdisk;
-	dev.d_type = priv->type;
-	dev.d_unit = priv->unit;
+	dev.dd.d_dev = &biosdisk;
+	dev.dd.d_type = priv->type;
+	dev.dd.d_unit = priv->unit;
 	dev.d_slice = priv->slice;
 	dev.d_partition = priv->part;
 	dev.d_offset = priv->start;
diff --git a/stand/i386/libi386/bootinfo32.c b/stand/i386/libi386/bootinfo32.c
index 494688fd7cd8..a0eed8c0d1b5 100644
--- a/stand/i386/libi386/bootinfo32.c
+++ b/stand/i386/libi386/bootinfo32.c
@@ -181,16 +181,16 @@ bi_load32(char *args, int *howtop, int *bootdevp, vm_offset_t *bip, vm_offset_t
     /* XXX - use a default bootdev of 0.  Is this ok??? */
     bootdevnr = 0;
 
-    switch(rootdev->d_type) {
+    switch(rootdev->dd.d_type) {
     case DEVT_CD:
 	    /* Pass in BIOS device number. */
-	    bi.bi_bios_dev = bc_unit2bios(rootdev->d_unit);
+	    bi.bi_bios_dev = bc_unit2bios(rootdev->dd.d_unit);
 	    bootdevnr = bc_getdev(rootdev);
 	    break;
 
     case DEVT_DISK:
 	/* pass in the BIOS device number of the current disk */
-	bi.bi_bios_dev = bd_unit2bios(rootdev->d_unit);
+	bi.bi_bios_dev = bd_unit2bios(rootdev->dd.d_unit);
 	bootdevnr = bd_getdev(rootdev);
 	break;
 
@@ -199,7 +199,7 @@ bi_load32(char *args, int *howtop, int *bootdevp, vm_offset_t *bip, vm_offset_t
 	    break;
 
     default:
-	printf("WARNING - don't know how to boot from device type %d\n", rootdev->d_type);
+	printf("WARNING - don't know how to boot from device type %d\n", rootdev->dd.d_type);
     }
     if (bootdevnr == -1) {
 	printf("root device %s invalid\n", i386_fmtdev(rootdev));
diff --git a/stand/i386/libi386/devicename.c b/stand/i386/libi386/devicename.c
index c7705d71386f..b53b62778844 100644
--- a/stand/i386/libi386/devicename.c
+++ b/stand/i386/libi386/devicename.c
@@ -135,7 +135,7 @@ i386_parsedev(struct i386_devdesc **dev, const char *devspec, const char **path)
 	    goto fail;
 	}
 
-	idev->d_unit = unit;
+	idev->dd.d_unit = unit;
 	if (path != NULL)
 	    *path = (*cp == 0) ? cp : cp + 1;
 	break;
@@ -148,8 +148,8 @@ i386_parsedev(struct i386_devdesc **dev, const char *devspec, const char **path)
 	err = EINVAL;
 	goto fail;
     }
-    idev->d_dev = dv;
-    idev->d_type = dv->dv_type;
+    idev->dd.d_dev = dv;
+    idev->dd.d_type = dv->dv_type;
     if (dev == NULL) {
 	free(idev);
     } else {
@@ -169,14 +169,14 @@ i386_fmtdev(void *vdev)
     struct i386_devdesc	*dev = (struct i386_devdesc *)vdev;
     static char		buf[128];	/* XXX device length constant? */
 
-    switch(dev->d_type) {
+    switch(dev->dd.d_type) {
     case DEVT_NONE:
 	strcpy(buf, "(no device)");
 	break;
 
     case DEVT_CD:
     case DEVT_NET:
-	sprintf(buf, "%s%d:", dev->d_dev->dv_name, dev->d_unit);
+	sprintf(buf, "%s%d:", dev->dd.d_dev->dv_name, dev->dd.d_unit);
 	break;
 
     case DEVT_DISK:
diff --git a/stand/i386/libi386/libi386.h b/stand/i386/libi386/libi386.h
index a2b1ec1d831e..da1ba4d69007 100644
--- a/stand/i386/libi386/libi386.h
+++ b/stand/i386/libi386/libi386.h
@@ -33,10 +33,7 @@
  */
 /* Note: Must match the 'struct devdesc' in stand.h */
 struct i386_devdesc {
-    struct devsw	*d_dev;
-    int			d_type;
-    int			d_unit;
-    void		*d_opendata;
+    struct devdesc	dd;
     union 
     {
 	struct 
diff --git a/stand/i386/loader/chain.c b/stand/i386/loader/chain.c
index d6810ef67fce..5b615288de0c 100644
--- a/stand/i386/loader/chain.c
+++ b/stand/i386/loader/chain.c
@@ -111,7 +111,7 @@ command_chain(int argc, char *argv[])
 	relocater_data[0].dest = 0x7C00;
 	relocater_data[0].size = SECTOR_SIZE;
 
-	relocator_edx = bd_unit2bios(rootdev->d_unit);
+	relocator_edx = bd_unit2bios(rootdev->dd.d_unit);
 	relocator_esi = relocater_size;
 	relocator_ds = 0;
 	relocator_es = 0;
diff --git a/stand/i386/loader/main.c b/stand/i386/loader/main.c
index 635f16088988..dfa173be1557 100644
--- a/stand/i386/loader/main.c
+++ b/stand/i386/loader/main.c
@@ -254,18 +254,18 @@ extract_currdev(void)
     int				biosdev = -1;
 
     /* Assume we are booting from a BIOS disk by default */
-    new_currdev.d_dev = &biosdisk;
+    new_currdev.dd.d_dev = &biosdisk;
 
     /* new-style boot loaders such as pxeldr and cdldr */
     if (kargs->bootinfo == 0) {
         if ((kargs->bootflags & KARGS_FLAGS_CD) != 0) {
 	    /* we are booting from a CD with cdboot */
-	    new_currdev.d_dev = &bioscd;
-	    new_currdev.d_unit = bc_bios2unit(initial_bootdev);
+	    new_currdev.dd.d_dev = &bioscd;
+	    new_currdev.dd.d_unit = bc_bios2unit(initial_bootdev);
 	} else if ((kargs->bootflags & KARGS_FLAGS_PXE) != 0) {
 	    /* we are booting from pxeldr */
-	    new_currdev.d_dev = &pxedisk;
-	    new_currdev.d_unit = 0;
+	    new_currdev.dd.d_dev = &pxedisk;
+	    new_currdev.dd.d_unit = 0;
 	} else {
 	    /* we don't know what our boot device is */
 	    new_currdev.d_kind.biosdisk.slice = -1;
@@ -295,7 +295,7 @@ extract_currdev(void)
 	    new_currdev.d_kind.zfs.pool_guid = kargs->zfspool;
 	    new_currdev.d_kind.zfs.root_guid = 0;
 	}
-	new_currdev.d_dev = &zfs_dev;
+	new_currdev.dd.d_dev = &zfs_dev;
 #endif
     } else if ((initial_bootdev & B_MAGICMASK) != B_DEVMAGIC) {
 	/* The passed-in boot device is bad */
@@ -316,21 +316,21 @@ extract_currdev(void)
 	if ((biosdev == 0) && (B_TYPE(initial_bootdev) != 2))	/* biosdev doesn't match major */
 	    biosdev = 0x80 + B_UNIT(initial_bootdev);		/* assume harddisk */
     }
-    new_currdev.d_type = new_currdev.d_dev->dv_type;
+    new_currdev.dd.d_type = new_currdev.dd.d_dev->dv_type;
 
     /*
      * If we are booting off of a BIOS disk and we didn't succeed in determining
      * which one we booted off of, just use disk0: as a reasonable default.
      */
-    if ((new_currdev.d_type == biosdisk.dv_type) &&
-	((new_currdev.d_unit = bd_bios2unit(biosdev)) == -1)) {
+    if ((new_currdev.dd.d_type == biosdisk.dv_type) &&
+	((new_currdev.dd.d_unit = bd_bios2unit(biosdev)) == -1)) {
 	printf("Can't work out which disk we are booting from.\n"
 	       "Guessed BIOS device 0x%x not found by probes, defaulting to disk0:\n", biosdev);
-	new_currdev.d_unit = 0;
+	new_currdev.dd.d_unit = 0;
     }
 
 #ifdef LOADER_ZFS_SUPPORT
-    if (new_currdev.d_type == DEVT_ZFS)
+    if (new_currdev.dd.d_type == DEVT_ZFS)
 	init_zfs_bootenv(zfs_fmtdev(&new_currdev));
 #endif
 
diff --git a/stand/mips/beri/loader/beri_disk_cfi.c b/stand/mips/beri/loader/beri_disk_cfi.c
index a21947fdfec6..76b7bb7a9a76 100644
--- a/stand/mips/beri/loader/beri_disk_cfi.c
+++ b/stand/mips/beri/loader/beri_disk_cfi.c
@@ -98,7 +98,7 @@ beri_cfi_disk_open(struct open_file *f, ...)
 	dev = va_arg(ap, struct disk_devdesc *);
 	va_end(ap);
 
-	if (dev->d_unit != 0)
+	if (dev->dd.d_unit != 0)
 		return (EIO);
 	return (disk_open(dev, cfi_get_mediasize(), cfi_get_sectorsize()));
 }
@@ -127,8 +127,8 @@ beri_cfi_disk_print(int verbose)
 	ret = pager_output(line);
 	if (ret != 0)
 		return (ret);
-	dev.d_dev = &beri_cfi_disk;
-	dev.d_unit = 0;
+	dev.dd.d_dev = &beri_cfi_disk;
+	dev.dd.d_unit = 0;
 	dev.d_slice = -1;
 	dev.d_partition = -1;
 	if (disk_open(&dev, cfi_get_mediasize(), cfi_get_sectorsize()) == 0) {
diff --git a/stand/mips/beri/loader/beri_disk_sdcard.c b/stand/mips/beri/loader/beri_disk_sdcard.c
index 266fb4a813f1..f577eaf55289 100644
--- a/stand/mips/beri/loader/beri_disk_sdcard.c
+++ b/stand/mips/beri/loader/beri_disk_sdcard.c
@@ -103,7 +103,7 @@ beri_sdcard_disk_open(struct open_file *f, ...)
 		return (ENXIO);
 	}
 
-	if (dev->d_unit != 0)
+	if (dev->dd.d_unit != 0)
 		return (EIO);
 	return (disk_open(dev, altera_sdcard_get_mediasize(),
 	    altera_sdcard_get_sectorsize()));
@@ -133,8 +133,8 @@ beri_sdcard_disk_print(int verbose)
 	ret = pager_output(line);
 	if (ret != 0)
 	    return (ret);
-	dev.d_dev = &beri_sdcard_disk;
-	dev.d_unit = 0;
+	dev.dd.d_dev = &beri_sdcard_disk;
+	dev.dd.d_unit = 0;
 	dev.d_slice = -1;
 	dev.d_partition = -1;
 	if (disk_open(&dev, altera_sdcard_get_mediasize(),
diff --git a/stand/mips/beri/loader/devicename.c b/stand/mips/beri/loader/devicename.c
index 968c946e82d8..4160bf66fb29 100644
--- a/stand/mips/beri/loader/devicename.c
+++ b/stand/mips/beri/loader/devicename.c
@@ -139,7 +139,7 @@ beri_arch_parsedev(struct disk_devdesc **dev, const char *devspec,
 	    goto fail;
 	}
 
-	idev->d_unit = unit;
+	idev->dd.d_unit = unit;
 	if (path != NULL)
 	    *path = (*cp == 0) ? cp : cp + 1;
 	break;
@@ -148,8 +148,8 @@ beri_arch_parsedev(struct disk_devdesc **dev, const char *devspec,
 	err = EINVAL;
 	goto fail;
     }
-    idev->d_dev = dv;
-    idev->d_type = dv->dv_type;
+    idev->dd.d_dev = dv;
+    idev->dd.d_type = dv->dv_type;
     if (dev == NULL) {
 	free(idev);
     } else {
@@ -175,7 +175,7 @@ beri_arch_fmtdev(void *vdev)
 	break;
 
     case DEVT_CD:
-	sprintf(buf, "%s%d:", dev->d_dev->dv_name, dev->d_unit);
+	sprintf(buf, "%s%d:", dev->dd.d_dev->dv_name, dev->dd.d_unit);
 	break;
 
     case DEVT_DISK:
@@ -183,7 +183,7 @@ beri_arch_fmtdev(void *vdev)
 
     case DEVT_NET:
     case DEVT_ZFS:
-	sprintf(buf, "%s%d:", dev->d_dev->dv_name, dev->d_unit);
+	sprintf(buf, "%s%d:", dev->dd.d_dev->dv_name, dev->dd.d_unit);
 	break;
     }
     return(buf);
diff --git a/stand/ofw/libofw/devicename.c b/stand/ofw/libofw/devicename.c
index c9814b76e97a..9d309a920db0 100644
--- a/stand/ofw/libofw/devicename.c
+++ b/stand/ofw/libofw/devicename.c
@@ -113,9 +113,9 @@ found:
 	return ENOMEM;
     }
     strcpy(idev->d_path, name);
-    idev->d_dev = dv;
-    idev->d_type = dv->dv_type;
-    if (idev->d_type == DEVT_ZFS) {
+    idev->dd.d_dev = dv;
+    idev->dd.d_type = dv->dv_type;
+    if (idev->dd.d_type == DEVT_ZFS) {
 	p = devspec + strlen(dv->dv_name);
 	err = zfs_parsedev((struct zfs_devdesc *)idev, p, path);
 	if (err != 0) {
diff --git a/stand/ofw/libofw/libofw.h b/stand/ofw/libofw/libofw.h
index d02fd6378274..a4bfc27699a4 100644
--- a/stand/ofw/libofw/libofw.h
+++ b/stand/ofw/libofw/libofw.h
@@ -27,14 +27,13 @@
 
 #include "openfirm.h"
 
-/* Note: Must match the 'struct devdesc' in stand.h */
 struct ofw_devdesc {
-	struct devsw	*d_dev;
-	int		d_type;
-	int		d_unit;
-	ihandle_t	d_handle;
+	struct devdesc			dd;
 	union {
-		char			d_path[256];
+		struct {
+			ihandle_t	d_handle;	
+			char		d_path[256];
+		};
 		struct {
 			uint64_t	pool_guid;
 			uint64_t	root_guid;
diff --git a/stand/sparc64/loader/main.c b/stand/sparc64/loader/main.c
index 4843aa98b1ff..edb9b4f0cdb8 100644
--- a/stand/sparc64/loader/main.c
+++ b/stand/sparc64/loader/main.c
@@ -806,8 +806,8 @@ sparc64_zfs_probe(void)
 	if (guid != 0) {
 		zfs_currdev.pool_guid = guid;
 		zfs_currdev.root_guid = 0;
-		zfs_currdev.d_dev = &zfs_dev;
-		zfs_currdev.d_type = zfs_currdev.d_dev->dv_type;
+		zfs_currdev.dd.d_dev = &zfs_dev;
+		zfs_currdev.dd.d_type = zfs_currdev.dd.d_dev->dv_type;
 	}
 }
 #endif /* LOADER_ZFS_SUPPORT */
diff --git a/stand/uboot/common/main.c b/stand/uboot/common/main.c
index a88a8bd0ae46..ffc76cae537d 100644
--- a/stand/uboot/common/main.c
+++ b/stand/uboot/common/main.c
@@ -318,7 +318,7 @@ print_disk_probe_info()
 		strcpy(partition, "<auto>");
 
 	printf("  Checking unit=%d slice=%s partition=%s...",
-	    currdev.d_unit, slice, partition);
+	    currdev.dd.d_unit, slice, partition);
 
 }
 
@@ -338,8 +338,8 @@ probe_disks(int devidx, int load_type, int load_unit, int load_slice,
 	if (load_type == -1) {
 		printf("  Probing all disk devices...\n");
 		/* Try each disk in succession until one works.  */
-		for (currdev.d_unit = 0; currdev.d_unit < UB_MAX_DEV;
-		     currdev.d_unit++) {
+		for (currdev.dd.d_unit = 0; currdev.dd.d_unit < UB_MAX_DEV;
+		     currdev.dd.d_unit++) {
 			print_disk_probe_info();
 			open_result = devsw[devidx]->dv_open(&f, &currdev);
 			if (open_result == 0) {
@@ -355,8 +355,8 @@ probe_disks(int devidx, int load_type, int load_unit, int load_slice,
 		printf("  Probing all %s devices...\n", device_typename(load_type));
 		/* Try each disk of given type in succession until one works. */
 		for (unit = 0; unit < UB_MAX_DEV; unit++) {
-			currdev.d_unit = uboot_diskgetunit(load_type, unit);
-			if (currdev.d_unit == -1)
+			currdev.dd.d_unit = uboot_diskgetunit(load_type, unit);
+			if (currdev.dd.d_unit == -1)
 				break;
 			print_disk_probe_info();
 			open_result = devsw[devidx]->dv_open(&f, &currdev);
@@ -369,7 +369,7 @@ probe_disks(int devidx, int load_type, int load_unit, int load_slice,
 		return (-1);
 	}
 
-	if ((currdev.d_unit = uboot_diskgetunit(load_type, load_unit)) != -1) {
+	if ((currdev.dd.d_unit = uboot_diskgetunit(load_type, load_unit)) != -1) {
 		print_disk_probe_info();
 		open_result = devsw[devidx]->dv_open(&f,&currdev);
 		if (open_result == 0) {
@@ -459,9 +459,9 @@ main(int argc, char **argv)
 
 		printf("Found U-Boot device: %s\n", devsw[i]->dv_name);
 
-		currdev.d_dev = devsw[i];
-		currdev.d_type = currdev.d_dev->dv_type;
-		currdev.d_unit = 0;
+		currdev.dd.d_dev = devsw[i];
+		currdev.dd.d_type = currdev.dd.d_dev->dv_type;
+		currdev.dd.d_unit = 0;
 
 		if ((load_type == -1 || (load_type & DEV_TYP_STOR)) &&
 		    strcmp(devsw[i]->dv_name, "disk") == 0) {
diff --git a/stand/uboot/lib/devicename.c b/stand/uboot/lib/devicename.c
index 9e68f9df9eb8..095a57f3dcc4 100644
--- a/stand/uboot/lib/devicename.c
+++ b/stand/uboot/lib/devicename.c
@@ -136,7 +136,7 @@ uboot_parsedev(struct uboot_devdesc **dev, const char *devspec,
 			err = EINVAL;
 			goto fail;
 		}
-		idev->d_unit = unit;
+		idev->dd.d_unit = unit;
 
 		if (path != NULL)
 			*path = (*cp == 0) ? cp : cp + 1;
@@ -146,8 +146,8 @@ uboot_parsedev(struct uboot_devdesc **dev, const char *devspec,
 		err = EINVAL;
 		goto fail;
 	}
-	idev->d_dev = dv;
-	idev->d_type = dv->dv_type;
+	idev->dd.d_dev = dv;
+	idev->dd.d_type = dv->dv_type;
 	if (dev == NULL) {
 		free(idev);
 	} else {
@@ -167,7 +167,7 @@ uboot_fmtdev(void *vdev)
 	struct uboot_devdesc *dev = (struct uboot_devdesc *)vdev;
 	static char buf[128];
 
-	switch(dev->d_type) {
+	switch(dev->dd.d_type) {
 	case DEVT_NONE:
 		strcpy(buf, "(no device)");
 		break;
@@ -178,7 +178,7 @@ uboot_fmtdev(void *vdev)
 #endif
 
 	case DEVT_NET:
-		sprintf(buf, "%s%d:", dev->d_dev->dv_name, dev->d_unit);
+		sprintf(buf, "%s%d:", dev->dd.d_dev->dv_name, dev->dd.d_unit);
 		break;
 	}
 	return(buf);
diff --git a/stand/uboot/lib/disk.c b/stand/uboot/lib/disk.c
index f5e44c749ba3..bf07d04f7e36 100644
--- a/stand/uboot/lib/disk.c
+++ b/stand/uboot/lib/disk.c
@@ -46,7 +46,7 @@ __FBSDID("$FreeBSD$");
 #include "libuboot.h"
 
 #define stor_printf(fmt, args...) do {			\
-    printf("%s%d: ", dev->d_dev->dv_name, dev->d_unit);	\
+    printf("%s%d: ", dev->dd.d_dev->dv_name, dev->dd.d_unit);	\
     printf(fmt, ##args);				\
 } while (0)
 
@@ -65,7 +65,7 @@ static struct {
 	u_int		bsize;	/* block size */
 } stor_info[UB_MAX_DEV];
 
-#define	SI(dev)		(stor_info[(dev)->d_unit])
+#define	SI(dev)		(stor_info[(dev)->dd.d_unit])
 
 static int stor_info_no = 0;
 static int stor_opendev(struct disk_devdesc *);
@@ -190,7 +190,7 @@ stor_opendev(struct disk_devdesc *dev)
 {
 	int err;
 
-	if (dev->d_unit < 0 || dev->d_unit >= stor_info_no)
+	if (dev->dd.d_unit < 0 || dev->dd.d_unit >= stor_info_no)
 		return (EIO);
 
 	if (SI(dev).opened == 0) {
@@ -252,8 +252,8 @@ stor_print(int verbose)
 		return (ret);
 
 	for (i = 0; i < stor_info_no; i++) {
-		dev.d_dev = &uboot_storage;
-		dev.d_unit = i;
+		dev.dd.d_dev = &uboot_storage;
+		dev.dd.d_unit = i;
 		dev.d_slice = -1;
 		dev.d_partition = -1;
 		snprintf(line, sizeof(line), "\tdisk%d (%s)\n", i,
diff --git a/stand/uboot/lib/libuboot.h b/stand/uboot/lib/libuboot.h
index efb789099e46..221f48f78784 100644
--- a/stand/uboot/lib/libuboot.h
+++ b/stand/uboot/lib/libuboot.h
@@ -29,10 +29,7 @@
 
 /* Note: Must match the 'struct devdesc' in stand.h */
 struct uboot_devdesc {
-	struct devsw	*d_dev;
-	int		d_type;
-	int		d_unit;
-	void		*d_opendata;
+	struct devdesc		dd;
 	union {
 		struct {
 			int	slice;
diff --git a/stand/userboot/userboot/devicename.c b/stand/userboot/userboot/devicename.c
index efa5634e541e..c33614ee9335 100644
--- a/stand/userboot/userboot/devicename.c
+++ b/stand/userboot/userboot/devicename.c
@@ -139,7 +139,7 @@ userboot_parsedev(struct disk_devdesc **dev, const char *devspec, const char **p
 	    goto fail;
 	}
 
-	idev->d_unit = unit;
+	idev->dd.d_unit = unit;
 	if (path != NULL)
 	    *path = (*cp == 0) ? cp : cp + 1;
 	break;
@@ -158,8 +158,8 @@ userboot_parsedev(struct disk_devdesc **dev, const char *devspec, const char **p
 	err = EINVAL;
 	goto fail;
     }
-    idev->d_dev = dv;
-    idev->d_type = dv->dv_type;
+    idev->dd.d_dev = dv;
+    idev->dd.d_type = dv->dv_type;
     if (dev == NULL) {
 	free(idev);
     } else {
@@ -179,27 +179,27 @@ userboot_fmtdev(void *vdev)
     struct disk_devdesc	*dev = (struct disk_devdesc *)vdev;
     static char		buf[128];	/* XXX device length constant? */
 
-    switch(dev->d_type) {
+    switch(dev->dd.d_type) {
     case DEVT_NONE:
 	strcpy(buf, "(no device)");
 	break;
 
     case DEVT_CD:
-	sprintf(buf, "%s%d:", dev->d_dev->dv_name, dev->d_unit);
+	sprintf(buf, "%s%d:", dev->dd.d_dev->dv_name, dev->dd.d_unit);
 	break;
 
     case DEVT_DISK:
 	return (disk_fmtdev(vdev));
 
     case DEVT_NET:
-	sprintf(buf, "%s%d:", dev->d_dev->dv_name, dev->d_unit);
+	sprintf(buf, "%s%d:", dev->dd.d_dev->dv_name, dev->dd.d_unit);
 	break;
 
     case DEVT_ZFS:
 #if defined(USERBOOT_ZFS_SUPPORT)
 	return (zfs_fmtdev(vdev));
 #else
-	sprintf(buf, "%s%d:", dev->d_dev->dv_name, dev->d_unit);
+	sprintf(buf, "%s%d:", dev->dd.d_dev->dv_name, dev->dd.d_unit);
 #endif
 	break;
     }
diff --git a/stand/userboot/userboot/main.c b/stand/userboot/userboot/main.c
index 00ca2433b0a7..8243b4c71775 100644
--- a/stand/userboot/userboot/main.c
+++ b/stand/userboot/userboot/main.c
@@ -159,13 +159,14 @@ extract_currdev(void)
 	//bzero(&dev, sizeof(dev));
 
 #if defined(USERBOOT_ZFS_SUPPORT)
+	CT_ASSERT(sizeof(struct disk_devdesc) >= sizeof(struct zfs_devdesc));
 	if (userboot_zfs_found) {
 		struct zfs_devdesc zdev;
 	
 		/* Leave the pool/root guid's unassigned */
 		bzero(&zdev, sizeof(zdev));
-		zdev.d_dev = &zfs_dev;
-		zdev.d_type = zdev.d_dev->dv_type;
+		zdev.dd.d_dev = &zfs_dev;
+		zdev.dd.d_type = zdev.dd.d_dev->dv_type;
 		
 		dev = *(struct disk_devdesc *)&zdev;
 		init_zfs_bootenv(zfs_fmtdev(&dev));
@@ -173,23 +174,23 @@ extract_currdev(void)
 #endif
 
 	if (userboot_disk_maxunit > 0) {
-		dev.d_dev = &userboot_disk;
-		dev.d_type = dev.d_dev->dv_type;
-		dev.d_unit = 0;
+		dev.dd.d_dev = &userboot_disk;
+		dev.dd.d_type = dev.dd.d_dev->dv_type;
+		dev.dd.d_unit = 0;
 		dev.d_slice = 0;
 		dev.d_partition = 0;
 		/*
 		 * If we cannot auto-detect the partition type then
 		 * access the disk as a raw device.
 		 */
-		if (dev.d_dev->dv_open(NULL, &dev)) {
+		if (dev.dd.d_dev->dv_open(NULL, &dev)) {
 			dev.d_slice = -1;
 			dev.d_partition = -1;
 		}
 	} else {
-		dev.d_dev = &host_dev;
-		dev.d_type = dev.d_dev->dv_type;
-		dev.d_unit = 0;
+		dev.dd.d_dev = &host_dev;
+		dev.dd.d_type = dev.dd.d_dev->dv_type;
+		dev.dd.d_unit = 0;
 	}
 
 	env_setenv("currdev", EV_VOLATILE, userboot_fmtdev(&dev),
diff --git a/stand/userboot/userboot/userboot_disk.c b/stand/userboot/userboot/userboot_disk.c
index fc21b5f1792d..149ba25dc059 100644
--- a/stand/userboot/userboot/userboot_disk.c
+++ b/stand/userboot/userboot/userboot_disk.c
@@ -135,8 +135,8 @@ userdisk_print(int verbose)
 		ret = pager_output(line);
 		if (ret != 0)
 			break;
-		dev.d_dev = &userboot_disk;
-		dev.d_unit = i;
+		dev.dd.d_dev = &userboot_disk;
+		dev.dd.d_unit = i;
 		dev.d_slice = -1;
 		dev.d_partition = -1;
 		if (disk_open(&dev, ud_info[i].mediasize,
@@ -164,13 +164,13 @@ userdisk_open(struct open_file *f, ...)
 	dev = va_arg(ap, struct disk_devdesc *);
 	va_end(ap);
 
-	if (dev->d_unit < 0 || dev->d_unit >= userdisk_maxunit)
+	if (dev->dd.d_unit < 0 || dev->dd.d_unit >= userdisk_maxunit)
 		return (EIO);
-	ud_info[dev->d_unit].ud_open++;
-	if (ud_info[dev->d_unit].ud_bcache == NULL)
-		ud_info[dev->d_unit].ud_bcache = bcache_allocate();
-	return (disk_open(dev, ud_info[dev->d_unit].mediasize,
-	    ud_info[dev->d_unit].sectorsize));
+	ud_info[dev->dd.d_unit].ud_open++;
+	if (ud_info[dev->dd.d_unit].ud_bcache == NULL)
+		ud_info[dev->dd.d_unit].ud_bcache = bcache_allocate();
+	return (disk_open(dev, ud_info[dev->dd.d_unit].mediasize,
+	    ud_info[dev->dd.d_unit].sectorsize));
 }
 
 static int
@@ -179,10 +179,10 @@ userdisk_close(struct open_file *f)
 	struct disk_devdesc *dev;
 
 	dev = (struct disk_devdesc *)f->f_devdata;
-	ud_info[dev->d_unit].ud_open--;
-	if (ud_info[dev->d_unit].ud_open == 0) {
-		bcache_free(ud_info[dev->d_unit].ud_bcache);
-		ud_info[dev->d_unit].ud_bcache = NULL;
+	ud_info[dev->dd.d_unit].ud_open--;
+	if (ud_info[dev->dd.d_unit].ud_open == 0) {
+		bcache_free(ud_info[dev->dd.d_unit].ud_bcache);
+		ud_info[dev->dd.d_unit].ud_bcache = NULL;
 	}
 	return (disk_close(dev));
 }
@@ -197,7 +197,7 @@ userdisk_strategy(void *devdata, int rw, daddr_t dblk, size_t size,
 	dev = (struct disk_devdesc *)devdata;
 	bcd.dv_strategy = userdisk_realstrategy;
 	bcd.dv_devdata = devdata;
-	bcd.dv_cache = ud_info[dev->d_unit].ud_bcache;
+	bcd.dv_cache = ud_info[dev->dd.d_unit].ud_bcache;
 	return (bcache_strategy(&bcd, rw, dblk + dev->d_offset,
 	    size, buf, rsize));
 }
@@ -218,8 +218,8 @@ userdisk_realstrategy(void *devdata, int rw, daddr_t dblk, size_t size,
 		return (EINVAL);
 	if (rsize)
 		*rsize = 0;
-	off = dblk * ud_info[dev->d_unit].sectorsize;
-	rc = CALLBACK(diskread, dev->d_unit, off, buf, size, &resid);
+	off = dblk * ud_info[dev->dd.d_unit].sectorsize;
+	rc = CALLBACK(diskread, dev->dd.d_unit, off, buf, size, &resid);
 	if (rc)
 		return (rc);
 	if (rsize)
@@ -238,5 +238,5 @@ userdisk_ioctl(struct open_file *f, u_long cmd, void *data)
 	if (rc != ENOTTY)
 		return (rc);
 
-	return (CALLBACK(diskioctl, dev->d_unit, cmd, data));
+	return (CALLBACK(diskioctl, dev->dd.d_unit, cmd, data));
 }
diff --git a/stand/zfs/libzfs.h b/stand/zfs/libzfs.h
index 7e89e7ec94e5..2da54d6f5120 100644
--- a/stand/zfs/libzfs.h
+++ b/stand/zfs/libzfs.h
@@ -38,12 +38,9 @@
  */
 /* Note: Must match the 'struct devdesc' in stand.h */
 struct zfs_devdesc {
-    struct devsw	*d_dev;
-    int			d_type;
-    int			d_unit;
-    void		*d_opendata;
-    uint64_t		pool_guid;
-    uint64_t		root_guid;
+	struct devdesc  dd;
+	uint64_t	pool_guid;
+	uint64_t	root_guid;
 };
 
 #ifdef LOADER_GELI_SUPPORT
diff --git a/stand/zfs/zfs.c b/stand/zfs/zfs.c
index 2b7bf228911b..297790a42bd1 100644
--- a/stand/zfs/zfs.c
+++ b/stand/zfs/zfs.c
@@ -687,8 +687,8 @@ zfs_parsedev(struct zfs_devdesc *dev, const char *devspec, const char **path)
 		return (rv);
 	if (path != NULL)
 		*path = (*end == '\0') ? end : end + 1;
-	dev->d_dev = &zfs_dev;
-	dev->d_type = zfs_dev.dv_type;
+	dev->dd.d_dev = &zfs_dev;
+	dev->dd.d_type = zfs_dev.dv_type;
 	return (0);
 }
 
@@ -701,7 +701,7 @@ zfs_fmtdev(void *vdev)
 	spa_t			*spa;
 
 	buf[0] = '\0';
-	if (dev->d_type != DEVT_ZFS)
+	if (dev->dd.d_type != DEVT_ZFS)
 		return (buf);
 
 	if (dev->pool_guid == 0) {
@@ -723,9 +723,9 @@ zfs_fmtdev(void *vdev)
 	}
 
 	if (rootname[0] == '\0')
-		sprintf(buf, "%s:%s:", dev->d_dev->dv_name, spa->spa_name);
+		sprintf(buf, "%s:%s:", dev->dd.d_dev->dv_name, spa->spa_name);
 	else
-		sprintf(buf, "%s:%s/%s:", dev->d_dev->dv_name, spa->spa_name,
+		sprintf(buf, "%s:%s/%s:", dev->dd.d_dev->dv_name, spa->spa_name,
 		    rootname);
 	return (buf);
 }