Update ZFS from version 6 to 13 and bring some FreeBSD-specific changes.

This bring huge amount of changes, I'll enumerate only user-visible changes:

- Delegated Administration

	Allows regular users to perform ZFS operations, like file system
	creation, snapshot creation, etc.

- L2ARC

	Level 2 cache for ZFS - allows to use additional disks for cache.
	Huge performance improvements mostly for random read of mostly
	static content.

- slog

	Allow to use additional disks for ZFS Intent Log to speed up
	operations like fsync(2).

- vfs.zfs.super_owner

	Allows regular users to perform privileged operations on files stored
	on ZFS file systems owned by him. Very careful with this one.

- chflags(2)

	Not all the flags are supported. This still needs work.

- ZFSBoot

	Support to boot off of ZFS pool. Not finished, AFAIK.

	Submitted by:	dfr

- Snapshot properties

- New failure modes

	Before if write requested failed, system paniced. Now one
	can select from one of three failure modes:
	- panic - panic on write error
	- wait - wait for disk to reappear
	- continue - serve read requests if possible, block write requests

- Refquota, refreservation properties

	Just quota and reservation properties, but don't count space consumed
	by children file systems, clones and snapshots.

- Sparse volumes

	ZVOLs that don't reserve space in the pool.

- External attributes

	Compatible with extattr(2).

- NFSv4-ACLs

	Not sure about the status, might not be complete yet.

	Submitted by:	trasz

- Creation-time properties

- Regression tests for zpool(8) command.

Obtained from:	OpenSolaris

6 files changed, 1619 insertions, 0 deletions

diff --git a/sys/cddl/boot/zfs/README b/sys/cddl/boot/zfs/README
new file mode 100644
index 0000000..4b62181
--- /dev/null
+++ b/sys/cddl/boot/zfs/README
@@ -0,0 +1,14 @@
+$FreeBSD$
+
+This directory contains various files derived from CDDL sources that
+are used by the ZFS bootstrap:
+
+    fletcher.c			checksum support
+    sha256.c			checksum support
+    lzjb.c			compression support
+    zfssubr.c			mostly checksum and compression support
+    zfsimpl.h			mostly describing the physical layout
+
+The files fletcher.c, lzjb.c and sha256.c are largely identical to the
+ZFS base code (with write support removed) and could be shared but
+that might complicate future imports from OpenSolaris.
diff --git a/sys/cddl/boot/zfs/fletcher.c b/sys/cddl/boot/zfs/fletcher.c
new file mode 100644
index 0000000..2b9728d
--- /dev/null
+++ b/sys/cddl/boot/zfs/fletcher.c
@@ -0,0 +1,60 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*#pragma ident	"%Z%%M%	%I%	%E% SMI"*/
+
+static void
+fletcher_2_native(const void *buf, uint64_t size, zio_cksum_t *zcp)
+{
+	const uint64_t *ip = buf;
+	const uint64_t *ipend = ip + (size / sizeof (uint64_t));
+	uint64_t a0, b0, a1, b1;
+
+	for (a0 = b0 = a1 = b1 = 0; ip < ipend; ip += 2) {
+		a0 += ip[0];
+		a1 += ip[1];
+		b0 += a0;
+		b1 += a1;
+	}
+
+	ZIO_SET_CHECKSUM(zcp, a0, a1, b0, b1);
+}
+
+static void
+fletcher_4_native(const void *buf, uint64_t size, zio_cksum_t *zcp)
+{
+	const uint32_t *ip = buf;
+	const uint32_t *ipend = ip + (size / sizeof (uint32_t));
+	uint64_t a, b, c, d;
+
+	for (a = b = c = d = 0; ip < ipend; ip++) {
+		a += ip[0];
+		b += a;
+		c += b;
+		d += c;
+	}
+
+	ZIO_SET_CHECKSUM(zcp, a, b, c, d);
+}
diff --git a/sys/cddl/boot/zfs/lzjb.c b/sys/cddl/boot/zfs/lzjb.c
new file mode 100644
index 0000000..1283a6c
--- /dev/null
+++ b/sys/cddl/boot/zfs/lzjb.c
@@ -0,0 +1,74 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*#pragma ident	"%Z%%M%	%I%	%E% SMI"*/
+
+/*
+ * We keep our own copy of this algorithm for 2 main reasons:
+ * 	1. If we didn't, anyone modifying common/os/compress.c would
+ *         directly break our on disk format
+ * 	2. Our version of lzjb does not have a number of checks that the
+ *         common/os version needs and uses
+ * In particular, we are adding the "feature" that compress() can
+ * take a destination buffer size and return -1 if the data will not
+ * compress to d_len or less.
+ */
+
+#define	MATCH_BITS	6
+#define	MATCH_MIN	3
+#define	MATCH_MAX	((1 << MATCH_BITS) + (MATCH_MIN - 1))
+#define	OFFSET_MASK	((1 << (16 - MATCH_BITS)) - 1)
+#define	LEMPEL_SIZE	256
+
+/*ARGSUSED*/
+static int
+lzjb_decompress(void *s_start, void *d_start, size_t s_len, size_t d_len, int n)
+{
+	unsigned char *src = s_start;
+	unsigned char *dst = d_start;
+	unsigned char *d_end = (unsigned char *)d_start + d_len;
+	unsigned char *cpy, copymap = 0;
+	int copymask = 1 << (NBBY - 1);
+
+	while (dst < d_end) {
+		if ((copymask <<= 1) == (1 << NBBY)) {
+			copymask = 1;
+			copymap = *src++;
+		}
+		if (copymap & copymask) {
+			int mlen = (src[0] >> (NBBY - MATCH_BITS)) + MATCH_MIN;
+			int offset = ((src[0] << NBBY) | src[1]) & OFFSET_MASK;
+			src += 2;
+			if ((cpy = dst - offset) < (unsigned char *)d_start)
+				return (-1);
+			while (--mlen >= 0 && dst < d_end)
+				*dst++ = *cpy++;
+		} else {
+			*dst++ = *src++;
+		}
+	}
+	return (0);
+}
diff --git a/sys/cddl/boot/zfs/sha256.c b/sys/cddl/boot/zfs/sha256.c
new file mode 100644
index 0000000..f0d83ac
--- /dev/null
+++ b/sys/cddl/boot/zfs/sha256.c
@@ -0,0 +1,127 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License, Version 1.0 only
+ * (the "License").  You may not use this file except in compliance
+ * with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/*#pragma ident	"%Z%%M%	%I%	%E% SMI"*/
+
+/*
+ * SHA-256 checksum, as specified in FIPS 180-2, available at:
+ * http://csrc.nist.gov/cryptval
+ *
+ * This is a very compact implementation of SHA-256.
+ * It is designed to be simple and portable, not to be fast.
+ */
+
+/*
+ * The literal definitions according to FIPS180-2 would be:
+ *
+ * 	Ch(x, y, z)     (((x) & (y)) ^ ((~(x)) & (z)))
+ * 	Maj(x, y, z)    (((x) & (y)) | ((x) & (z)) | ((y) & (z)))
+ *
+ * We use logical equivalents which require one less op.
+ */
+#define	Ch(x, y, z)	((z) ^ ((x) & ((y) ^ (z))))
+#define	Maj(x, y, z)	(((x) & (y)) ^ ((z) & ((x) ^ (y))))
+#define	Rot32(x, s)	(((x) >> s) | ((x) << (32 - s)))
+#define	SIGMA0(x)	(Rot32(x, 2) ^ Rot32(x, 13) ^ Rot32(x, 22))
+#define	SIGMA1(x)	(Rot32(x, 6) ^ Rot32(x, 11) ^ Rot32(x, 25))
+#define	sigma0(x)	(Rot32(x, 7) ^ Rot32(x, 18) ^ ((x) >> 3))
+#define	sigma1(x)	(Rot32(x, 17) ^ Rot32(x, 19) ^ ((x) >> 10))
+
+static const uint32_t SHA256_K[64] = {
+	0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
+	0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
+	0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
+	0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
+	0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
+	0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
+	0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
+	0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
+	0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
+	0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
+	0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
+	0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
+	0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
+	0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
+	0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
+	0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
+};
+
+static void
+SHA256Transform(uint32_t *H, const uint8_t *cp)
+{
+	uint32_t a, b, c, d, e, f, g, h, t, T1, T2, W[64];
+
+	for (t = 0; t < 16; t++, cp += 4)
+		W[t] = (cp[0] << 24) | (cp[1] << 16) | (cp[2] << 8) | cp[3];
+
+	for (t = 16; t < 64; t++)
+		W[t] = sigma1(W[t - 2]) + W[t - 7] +
+		    sigma0(W[t - 15]) + W[t - 16];
+
+	a = H[0]; b = H[1]; c = H[2]; d = H[3];
+	e = H[4]; f = H[5]; g = H[6]; h = H[7];
+
+	for (t = 0; t < 64; t++) {
+		T1 = h + SIGMA1(e) + Ch(e, f, g) + SHA256_K[t] + W[t];
+		T2 = SIGMA0(a) + Maj(a, b, c);
+		h = g; g = f; f = e; e = d + T1;
+		d = c; c = b; b = a; a = T1 + T2;
+	}
+
+	H[0] += a; H[1] += b; H[2] += c; H[3] += d;
+	H[4] += e; H[5] += f; H[6] += g; H[7] += h;
+}
+
+static void
+zio_checksum_SHA256(const void *buf, uint64_t size, zio_cksum_t *zcp)
+{
+	uint32_t H[8] = { 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
+	    0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19 };
+	uint8_t pad[128];
+	int padsize = size & 63;
+	int i;
+
+	for (i = 0; i < size - padsize; i += 64)
+		SHA256Transform(H, (uint8_t *)buf + i);
+
+	for (i = 0; i < padsize; i++)
+		pad[i] = ((uint8_t *)buf)[i];
+
+	for (pad[padsize++] = 0x80; (padsize & 63) != 56; padsize++)
+		pad[padsize] = 0;
+
+	for (i = 0; i < 8; i++)
+		pad[padsize++] = (size << 3) >> (56 - 8 * i);
+
+	for (i = 0; i < padsize; i += 64)
+		SHA256Transform(H, pad + i);
+
+	ZIO_SET_CHECKSUM(zcp,
+	    (uint64_t)H[0] << 32 | H[1],
+	    (uint64_t)H[2] << 32 | H[3],
+	    (uint64_t)H[4] << 32 | H[5],
+	    (uint64_t)H[6] << 32 | H[7]);
+}
diff --git a/sys/cddl/boot/zfs/zfsimpl.h b/sys/cddl/boot/zfs/zfsimpl.h
new file mode 100644
index 0000000..3d178b4
--- /dev/null
+++ b/sys/cddl/boot/zfs/zfsimpl.h
@@ -0,0 +1,1151 @@
+/*-
+ * Copyright (c) 2002 McAfee, Inc.
+ * All rights reserved.
+ *
+ * This software was developed for the FreeBSD Project by Marshall
+ * Kirk McKusick and McAfee Research,, the Security Research Division of
+ * McAfee, Inc. under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as
+ * part of the DARPA CHATS research program
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+/* CRC64 table */
+#define	ZFS_CRC64_POLY	0xC96C5795D7870F42ULL	/* ECMA-182, reflected form */
+
+/*
+ * Macros for various sorts of alignment and rounding when the alignment
+ * is known to be a power of 2.
+ */
+#define	P2ALIGN(x, align)		((x) & -(align))
+#define	P2PHASE(x, align)		((x) & ((align) - 1))
+#define	P2NPHASE(x, align)		(-(x) & ((align) - 1))
+#define	P2ROUNDUP(x, align)		(-(-(x) & -(align)))
+#define	P2END(x, align)			(-(~(x) & -(align)))
+#define	P2PHASEUP(x, align, phase)	((phase) - (((phase) - (x)) & -(align)))
+#define	P2CROSS(x, y, align)		(((x) ^ (y)) > (align) - 1)
+
+/*
+ * General-purpose 32-bit and 64-bit bitfield encodings.
+ */
+#define	BF32_DECODE(x, low, len)	P2PHASE((x) >> (low), 1U << (len))
+#define	BF64_DECODE(x, low, len)	P2PHASE((x) >> (low), 1ULL << (len))
+#define	BF32_ENCODE(x, low, len)	(P2PHASE((x), 1U << (len)) << (low))
+#define	BF64_ENCODE(x, low, len)	(P2PHASE((x), 1ULL << (len)) << (low))
+
+#define	BF32_GET(x, low, len)		BF32_DECODE(x, low, len)
+#define	BF64_GET(x, low, len)		BF64_DECODE(x, low, len)
+
+#define	BF32_SET(x, low, len, val)	\
+	((x) ^= BF32_ENCODE((x >> low) ^ (val), low, len))
+#define	BF64_SET(x, low, len, val)	\
+	((x) ^= BF64_ENCODE((x >> low) ^ (val), low, len))
+
+#define	BF32_GET_SB(x, low, len, shift, bias)	\
+	((BF32_GET(x, low, len) + (bias)) << (shift))
+#define	BF64_GET_SB(x, low, len, shift, bias)	\
+	((BF64_GET(x, low, len) + (bias)) << (shift))
+
+#define	BF32_SET_SB(x, low, len, shift, bias, val)	\
+	BF32_SET(x, low, len, ((val) >> (shift)) - (bias))
+#define	BF64_SET_SB(x, low, len, shift, bias, val)	\
+	BF64_SET(x, low, len, ((val) >> (shift)) - (bias))
+
+/*
+ * We currently support nine block sizes, from 512 bytes to 128K.
+ * We could go higher, but the benefits are near-zero and the cost
+ * of COWing a giant block to modify one byte would become excessive.
+ */
+#define	SPA_MINBLOCKSHIFT	9
+#define	SPA_MAXBLOCKSHIFT	17
+#define	SPA_MINBLOCKSIZE	(1ULL << SPA_MINBLOCKSHIFT)
+#define	SPA_MAXBLOCKSIZE	(1ULL << SPA_MAXBLOCKSHIFT)
+
+#define	SPA_BLOCKSIZES		(SPA_MAXBLOCKSHIFT - SPA_MINBLOCKSHIFT + 1)
+
+/*
+ * The DVA size encodings for LSIZE and PSIZE support blocks up to 32MB.
+ * The ASIZE encoding should be at least 64 times larger (6 more bits)
+ * to support up to 4-way RAID-Z mirror mode with worst-case gang block
+ * overhead, three DVAs per bp, plus one more bit in case we do anything
+ * else that expands the ASIZE.
+ */
+#define	SPA_LSIZEBITS		16	/* LSIZE up to 32M (2^16 * 512)	*/
+#define	SPA_PSIZEBITS		16	/* PSIZE up to 32M (2^16 * 512)	*/
+#define	SPA_ASIZEBITS		24	/* ASIZE up to 64 times larger	*/
+
+/*
+ * All SPA data is represented by 128-bit data virtual addresses (DVAs).
+ * The members of the dva_t should be considered opaque outside the SPA.
+ */
+typedef struct dva {
+	uint64_t	dva_word[2];
+} dva_t;
+
+/*
+ * Each block has a 256-bit checksum -- strong enough for cryptographic hashes.
+ */
+typedef struct zio_cksum {
+	uint64_t	zc_word[4];
+} zio_cksum_t;
+
+/*
+ * Each block is described by its DVAs, time of birth, checksum, etc.
+ * The word-by-word, bit-by-bit layout of the blkptr is as follows:
+ *
+ *	64	56	48	40	32	24	16	8	0
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * 0	|		vdev1		| GRID  |	  ASIZE		|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * 1	|G|			 offset1				|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * 2	|		vdev2		| GRID  |	  ASIZE		|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * 3	|G|			 offset2				|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * 4	|		vdev3		| GRID  |	  ASIZE		|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * 5	|G|			 offset3				|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * 6	|E| lvl | type	| cksum | comp	|     PSIZE	|     LSIZE	|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * 7	|			padding					|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * 8	|			padding					|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * 9	|			padding					|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * a	|			birth txg				|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * b	|			fill count				|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * c	|			checksum[0]				|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * d	|			checksum[1]				|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * e	|			checksum[2]				|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ * f	|			checksum[3]				|
+ *	+-------+-------+-------+-------+-------+-------+-------+-------+
+ *
+ * Legend:
+ *
+ * vdev		virtual device ID
+ * offset	offset into virtual device
+ * LSIZE	logical size
+ * PSIZE	physical size (after compression)
+ * ASIZE	allocated size (including RAID-Z parity and gang block headers)
+ * GRID		RAID-Z layout information (reserved for future use)
+ * cksum	checksum function
+ * comp		compression function
+ * G		gang block indicator
+ * E		endianness
+ * type		DMU object type
+ * lvl		level of indirection
+ * birth txg	transaction group in which the block was born
+ * fill count	number of non-zero blocks under this bp
+ * checksum[4]	256-bit checksum of the data this bp describes
+ */
+typedef struct blkptr {
+	dva_t		blk_dva[3];	/* 128-bit Data Virtual Address	*/
+	uint64_t	blk_prop;	/* size, compression, type, etc	*/
+	uint64_t	blk_pad[3];	/* Extra space for the future	*/
+	uint64_t	blk_birth;	/* transaction group at birth	*/
+	uint64_t	blk_fill;	/* fill count			*/
+	zio_cksum_t	blk_cksum;	/* 256-bit checksum		*/
+} blkptr_t;
+
+#define	SPA_BLKPTRSHIFT	7		/* blkptr_t is 128 bytes	*/
+#define	SPA_DVAS_PER_BP	3		/* Number of DVAs in a bp	*/
+
+/*
+ * Macros to get and set fields in a bp or DVA.
+ */
+#define	DVA_GET_ASIZE(dva)	\
+	BF64_GET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0)
+#define	DVA_SET_ASIZE(dva, x)	\
+	BF64_SET_SB((dva)->dva_word[0], 0, 24, SPA_MINBLOCKSHIFT, 0, x)
+
+#define	DVA_GET_GRID(dva)	BF64_GET((dva)->dva_word[0], 24, 8)
+#define	DVA_SET_GRID(dva, x)	BF64_SET((dva)->dva_word[0], 24, 8, x)
+
+#define	DVA_GET_VDEV(dva)	BF64_GET((dva)->dva_word[0], 32, 32)
+#define	DVA_SET_VDEV(dva, x)	BF64_SET((dva)->dva_word[0], 32, 32, x)
+
+#define	DVA_GET_OFFSET(dva)	\
+	BF64_GET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0)
+#define	DVA_SET_OFFSET(dva, x)	\
+	BF64_SET_SB((dva)->dva_word[1], 0, 63, SPA_MINBLOCKSHIFT, 0, x)
+
+#define	DVA_GET_GANG(dva)	BF64_GET((dva)->dva_word[1], 63, 1)
+#define	DVA_SET_GANG(dva, x)	BF64_SET((dva)->dva_word[1], 63, 1, x)
+
+#define	BP_GET_LSIZE(bp)	\
+	(BP_IS_HOLE(bp) ? 0 : \
+	BF64_GET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1))
+#define	BP_SET_LSIZE(bp, x)	\
+	BF64_SET_SB((bp)->blk_prop, 0, 16, SPA_MINBLOCKSHIFT, 1, x)
+
+#define	BP_GET_PSIZE(bp)	\
+	BF64_GET_SB((bp)->blk_prop, 16, 16, SPA_MINBLOCKSHIFT, 1)
+#define	BP_SET_PSIZE(bp, x)	\
+	BF64_SET_SB((bp)->blk_prop, 16, 16, SPA_MINBLOCKSHIFT, 1, x)
+
+#define	BP_GET_COMPRESS(bp)	BF64_GET((bp)->blk_prop, 32, 8)
+#define	BP_SET_COMPRESS(bp, x)	BF64_SET((bp)->blk_prop, 32, 8, x)
+
+#define	BP_GET_CHECKSUM(bp)	BF64_GET((bp)->blk_prop, 40, 8)
+#define	BP_SET_CHECKSUM(bp, x)	BF64_SET((bp)->blk_prop, 40, 8, x)
+
+#define	BP_GET_TYPE(bp)		BF64_GET((bp)->blk_prop, 48, 8)
+#define	BP_SET_TYPE(bp, x)	BF64_SET((bp)->blk_prop, 48, 8, x)
+
+#define	BP_GET_LEVEL(bp)	BF64_GET((bp)->blk_prop, 56, 5)
+#define	BP_SET_LEVEL(bp, x)	BF64_SET((bp)->blk_prop, 56, 5, x)
+
+#define	BP_GET_BYTEORDER(bp)	(0 - BF64_GET((bp)->blk_prop, 63, 1))
+#define	BP_SET_BYTEORDER(bp, x)	BF64_SET((bp)->blk_prop, 63, 1, x)
+
+#define	BP_GET_ASIZE(bp)	\
+	(DVA_GET_ASIZE(&(bp)->blk_dva[0]) + DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
+		DVA_GET_ASIZE(&(bp)->blk_dva[2]))
+
+#define	BP_GET_UCSIZE(bp) \
+	((BP_GET_LEVEL(bp) > 0 || dmu_ot[BP_GET_TYPE(bp)].ot_metadata) ? \
+	BP_GET_PSIZE(bp) : BP_GET_LSIZE(bp));
+
+#define	BP_GET_NDVAS(bp)	\
+	(!!DVA_GET_ASIZE(&(bp)->blk_dva[0]) + \
+	!!DVA_GET_ASIZE(&(bp)->blk_dva[1]) + \
+	!!DVA_GET_ASIZE(&(bp)->blk_dva[2]))
+
+#define	BP_COUNT_GANG(bp)	\
+	(DVA_GET_GANG(&(bp)->blk_dva[0]) + \
+	DVA_GET_GANG(&(bp)->blk_dva[1]) + \
+	DVA_GET_GANG(&(bp)->blk_dva[2]))
+
+#define	DVA_EQUAL(dva1, dva2)	\
+	((dva1)->dva_word[1] == (dva2)->dva_word[1] && \
+	(dva1)->dva_word[0] == (dva2)->dva_word[0])
+
+#define	ZIO_CHECKSUM_EQUAL(zc1, zc2) \
+	(0 == (((zc1).zc_word[0] - (zc2).zc_word[0]) | \
+	((zc1).zc_word[1] - (zc2).zc_word[1]) | \
+	((zc1).zc_word[2] - (zc2).zc_word[2]) | \
+	((zc1).zc_word[3] - (zc2).zc_word[3])))
+
+
+#define	DVA_IS_VALID(dva)	(DVA_GET_ASIZE(dva) != 0)
+
+#define	ZIO_SET_CHECKSUM(zcp, w0, w1, w2, w3)	\
+{						\
+	(zcp)->zc_word[0] = w0;			\
+	(zcp)->zc_word[1] = w1;			\
+	(zcp)->zc_word[2] = w2;			\
+	(zcp)->zc_word[3] = w3;			\
+}
+
+#define	BP_IDENTITY(bp)		(&(bp)->blk_dva[0])
+#define	BP_IS_GANG(bp)		DVA_GET_GANG(BP_IDENTITY(bp))
+#define	BP_IS_HOLE(bp)		((bp)->blk_birth == 0)
+#define	BP_IS_OLDER(bp, txg)	(!BP_IS_HOLE(bp) && (bp)->blk_birth < (txg))
+
+#define	BP_ZERO(bp)				\
+{						\
+	(bp)->blk_dva[0].dva_word[0] = 0;	\
+	(bp)->blk_dva[0].dva_word[1] = 0;	\
+	(bp)->blk_dva[1].dva_word[0] = 0;	\
+	(bp)->blk_dva[1].dva_word[1] = 0;	\
+	(bp)->blk_dva[2].dva_word[0] = 0;	\
+	(bp)->blk_dva[2].dva_word[1] = 0;	\
+	(bp)->blk_prop = 0;			\
+	(bp)->blk_pad[0] = 0;			\
+	(bp)->blk_pad[1] = 0;			\
+	(bp)->blk_pad[2] = 0;			\
+	(bp)->blk_birth = 0;			\
+	(bp)->blk_fill = 0;			\
+	ZIO_SET_CHECKSUM(&(bp)->blk_cksum, 0, 0, 0, 0);	\
+}
+
+#define	ZBT_MAGIC	0x210da7ab10c7a11ULL	/* zio data bloc tail */
+
+typedef struct zio_block_tail {
+	uint64_t	zbt_magic;	/* for validation, endianness	*/
+	zio_cksum_t	zbt_cksum;	/* 256-bit checksum		*/
+} zio_block_tail_t;
+
+#define	VDEV_SKIP_SIZE		(8 << 10)
+#define	VDEV_BOOT_HEADER_SIZE	(8 << 10)
+#define	VDEV_PHYS_SIZE		(112 << 10)
+#define	VDEV_UBERBLOCK_RING	(128 << 10)
+
+#define	VDEV_UBERBLOCK_SHIFT(vd)	\
+	MAX((vd)->vdev_top->vdev_ashift, UBERBLOCK_SHIFT)
+#define	VDEV_UBERBLOCK_COUNT(vd)	\
+	(VDEV_UBERBLOCK_RING >> VDEV_UBERBLOCK_SHIFT(vd))
+#define	VDEV_UBERBLOCK_OFFSET(vd, n)	\
+	offsetof(vdev_label_t, vl_uberblock[(n) << VDEV_UBERBLOCK_SHIFT(vd)])
+#define	VDEV_UBERBLOCK_SIZE(vd)		(1ULL << VDEV_UBERBLOCK_SHIFT(vd))
+
+/* ZFS boot block */
+#define	VDEV_BOOT_MAGIC		0x2f5b007b10cULL
+#define	VDEV_BOOT_VERSION	1		/* version number	*/
+
+typedef struct vdev_boot_header {
+	uint64_t	vb_magic;		/* VDEV_BOOT_MAGIC	*/
+	uint64_t	vb_version;		/* VDEV_BOOT_VERSION	*/
+	uint64_t	vb_offset;		/* start offset	(bytes) */
+	uint64_t	vb_size;		/* size (bytes)		*/
+	char		vb_pad[VDEV_BOOT_HEADER_SIZE - 4 * sizeof (uint64_t)];
+} vdev_boot_header_t;
+
+typedef struct vdev_phys {
+	char		vp_nvlist[VDEV_PHYS_SIZE - sizeof (zio_block_tail_t)];
+	zio_block_tail_t vp_zbt;
+} vdev_phys_t;
+
+typedef struct vdev_label {
+	char		vl_pad[VDEV_SKIP_SIZE];			/*   8K	*/
+	vdev_boot_header_t vl_boot_header;			/*   8K	*/
+	vdev_phys_t	vl_vdev_phys;				/* 112K	*/
+	char		vl_uberblock[VDEV_UBERBLOCK_RING];	/* 128K	*/
+} vdev_label_t;							/* 256K total */
+
+/*
+ * vdev_dirty() flags
+ */
+#define	VDD_METASLAB	0x01
+#define	VDD_DTL		0x02
+
+/*
+ * Size and offset of embedded boot loader region on each label.
+ * The total size of the first two labels plus the boot area is 4MB.
+ */
+#define	VDEV_BOOT_OFFSET	(2 * sizeof (vdev_label_t))
+#define	VDEV_BOOT_SIZE		(7ULL << 19)			/* 3.5M	*/
+
+/*
+ * Size of label regions at the start and end of each leaf device.
+ */
+#define	VDEV_LABEL_START_SIZE	(2 * sizeof (vdev_label_t) + VDEV_BOOT_SIZE)
+#define	VDEV_LABEL_END_SIZE	(2 * sizeof (vdev_label_t))
+#define	VDEV_LABELS		4
+
+enum zio_checksum {
+	ZIO_CHECKSUM_INHERIT = 0,
+	ZIO_CHECKSUM_ON,
+	ZIO_CHECKSUM_OFF,
+	ZIO_CHECKSUM_LABEL,
+	ZIO_CHECKSUM_GANG_HEADER,
+	ZIO_CHECKSUM_ZILOG,
+	ZIO_CHECKSUM_FLETCHER_2,
+	ZIO_CHECKSUM_FLETCHER_4,
+	ZIO_CHECKSUM_SHA256,
+	ZIO_CHECKSUM_FUNCTIONS
+};
+
+#define	ZIO_CHECKSUM_ON_VALUE	ZIO_CHECKSUM_FLETCHER_2
+#define	ZIO_CHECKSUM_DEFAULT	ZIO_CHECKSUM_ON
+
+enum zio_compress {
+	ZIO_COMPRESS_INHERIT = 0,
+	ZIO_COMPRESS_ON,
+	ZIO_COMPRESS_OFF,
+	ZIO_COMPRESS_LZJB,
+	ZIO_COMPRESS_EMPTY,
+	ZIO_COMPRESS_GZIP_1,
+	ZIO_COMPRESS_GZIP_2,
+	ZIO_COMPRESS_GZIP_3,
+	ZIO_COMPRESS_GZIP_4,
+	ZIO_COMPRESS_GZIP_5,
+	ZIO_COMPRESS_GZIP_6,
+	ZIO_COMPRESS_GZIP_7,
+	ZIO_COMPRESS_GZIP_8,
+	ZIO_COMPRESS_GZIP_9,
+	ZIO_COMPRESS_FUNCTIONS
+};
+
+#define	ZIO_COMPRESS_ON_VALUE	ZIO_COMPRESS_LZJB
+#define	ZIO_COMPRESS_DEFAULT	ZIO_COMPRESS_OFF
+
+/* nvlist pack encoding */
+#define	NV_ENCODE_NATIVE	0
+#define	NV_ENCODE_XDR		1
+
+typedef enum {
+	DATA_TYPE_UNKNOWN = 0,
+	DATA_TYPE_BOOLEAN,
+	DATA_TYPE_BYTE,
+	DATA_TYPE_INT16,
+	DATA_TYPE_UINT16,
+	DATA_TYPE_INT32,
+	DATA_TYPE_UINT32,
+	DATA_TYPE_INT64,
+	DATA_TYPE_UINT64,
+	DATA_TYPE_STRING,
+	DATA_TYPE_BYTE_ARRAY,
+	DATA_TYPE_INT16_ARRAY,
+	DATA_TYPE_UINT16_ARRAY,
+	DATA_TYPE_INT32_ARRAY,
+	DATA_TYPE_UINT32_ARRAY,
+	DATA_TYPE_INT64_ARRAY,
+	DATA_TYPE_UINT64_ARRAY,
+	DATA_TYPE_STRING_ARRAY,
+	DATA_TYPE_HRTIME,
+	DATA_TYPE_NVLIST,
+	DATA_TYPE_NVLIST_ARRAY,
+	DATA_TYPE_BOOLEAN_VALUE,
+	DATA_TYPE_INT8,
+	DATA_TYPE_UINT8,
+	DATA_TYPE_BOOLEAN_ARRAY,
+	DATA_TYPE_INT8_ARRAY,
+	DATA_TYPE_UINT8_ARRAY
+} data_type_t;
+
+/*
+ * On-disk version number.
+ */
+#define	ZFS_VERSION_1			1ULL
+#define	ZFS_VERSION_2			2ULL
+#define	ZFS_VERSION_3			3ULL
+#define	ZFS_VERSION_4			4ULL
+#define	ZFS_VERSION_5			5ULL
+#define	ZFS_VERSION_6			6ULL
+/*
+ * When bumping up ZFS_VERSION, make sure GRUB ZFS understand the on-disk
+ * format change. Go to usr/src/grub/grub-0.95/stage2/{zfs-include/, fsys_zfs*},
+ * and do the appropriate changes.
+ */
+#define	ZFS_VERSION			ZFS_VERSION_6
+#define	ZFS_VERSION_STRING		"6"
+
+/*
+ * Symbolic names for the changes that caused a ZFS_VERSION switch.
+ * Used in the code when checking for presence or absence of a feature.
+ * Feel free to define multiple symbolic names for each version if there
+ * were multiple changes to on-disk structures during that version.
+ *
+ * NOTE: When checking the current ZFS_VERSION in your code, be sure
+ *       to use spa_version() since it reports the version of the
+ *       last synced uberblock.  Checking the in-flight version can
+ *       be dangerous in some cases.
+ */
+#define	ZFS_VERSION_INITIAL		ZFS_VERSION_1
+#define	ZFS_VERSION_DITTO_BLOCKS	ZFS_VERSION_2
+#define	ZFS_VERSION_SPARES		ZFS_VERSION_3
+#define	ZFS_VERSION_RAID6		ZFS_VERSION_3
+#define	ZFS_VERSION_BPLIST_ACCOUNT	ZFS_VERSION_3
+#define	ZFS_VERSION_RAIDZ_DEFLATE	ZFS_VERSION_3
+#define	ZFS_VERSION_DNODE_BYTES		ZFS_VERSION_3
+#define	ZFS_VERSION_ZPOOL_HISTORY	ZFS_VERSION_4
+#define	ZFS_VERSION_GZIP_COMPRESSION	ZFS_VERSION_5
+#define	ZFS_VERSION_BOOTFS		ZFS_VERSION_6
+
+/*
+ * The following are configuration names used in the nvlist describing a pool's
+ * configuration.
+ */
+#define	ZPOOL_CONFIG_VERSION		"version"
+#define	ZPOOL_CONFIG_POOL_NAME		"name"
+#define	ZPOOL_CONFIG_POOL_STATE		"state"
+#define	ZPOOL_CONFIG_POOL_TXG		"txg"
+#define	ZPOOL_CONFIG_POOL_GUID		"pool_guid"
+#define	ZPOOL_CONFIG_CREATE_TXG		"create_txg"
+#define	ZPOOL_CONFIG_TOP_GUID		"top_guid"
+#define	ZPOOL_CONFIG_VDEV_TREE		"vdev_tree"
+#define	ZPOOL_CONFIG_TYPE		"type"
+#define	ZPOOL_CONFIG_CHILDREN		"children"
+#define	ZPOOL_CONFIG_ID			"id"
+#define	ZPOOL_CONFIG_GUID		"guid"
+#define	ZPOOL_CONFIG_PATH		"path"
+#define	ZPOOL_CONFIG_DEVID		"devid"
+#define	ZPOOL_CONFIG_METASLAB_ARRAY	"metaslab_array"
+#define	ZPOOL_CONFIG_METASLAB_SHIFT	"metaslab_shift"
+#define	ZPOOL_CONFIG_ASHIFT		"ashift"
+#define	ZPOOL_CONFIG_ASIZE		"asize"
+#define	ZPOOL_CONFIG_DTL		"DTL"
+#define	ZPOOL_CONFIG_STATS		"stats"
+#define	ZPOOL_CONFIG_WHOLE_DISK		"whole_disk"
+#define	ZPOOL_CONFIG_OFFLINE		"offline"
+#define	ZPOOL_CONFIG_ERRCOUNT		"error_count"
+#define	ZPOOL_CONFIG_NOT_PRESENT	"not_present"
+#define	ZPOOL_CONFIG_SPARES		"spares"
+#define	ZPOOL_CONFIG_IS_SPARE		"is_spare"
+#define	ZPOOL_CONFIG_NPARITY		"nparity"
+#define	ZPOOL_CONFIG_HOSTID		"hostid"
+#define	ZPOOL_CONFIG_HOSTNAME		"hostname"
+#define	ZPOOL_CONFIG_TIMESTAMP		"timestamp" /* not stored on disk */
+
+#define	VDEV_TYPE_ROOT			"root"
+#define	VDEV_TYPE_MIRROR		"mirror"
+#define	VDEV_TYPE_REPLACING		"replacing"
+#define	VDEV_TYPE_RAIDZ			"raidz"
+#define	VDEV_TYPE_DISK			"disk"
+#define	VDEV_TYPE_FILE			"file"
+#define	VDEV_TYPE_MISSING		"missing"
+#define	VDEV_TYPE_SPARE			"spare"
+
+/*
+ * This is needed in userland to report the minimum necessary device size.
+ */
+#define	SPA_MINDEVSIZE		(64ULL << 20)
+
+/*
+ * The location of the pool configuration repository, shared between kernel and
+ * userland.
+ */
+#define	ZPOOL_CACHE_DIR		"/boot/zfs"
+#define	ZPOOL_CACHE_FILE	"zpool.cache"
+#define	ZPOOL_CACHE_TMP		".zpool.cache"
+
+#define	ZPOOL_CACHE		ZPOOL_CACHE_DIR "/" ZPOOL_CACHE_FILE
+
+/*
+ * vdev states are ordered from least to most healthy.
+ * A vdev that's CANT_OPEN or below is considered unusable.
+ */
+typedef enum vdev_state {
+	VDEV_STATE_UNKNOWN = 0,	/* Uninitialized vdev			*/
+	VDEV_STATE_CLOSED,	/* Not currently open			*/
+	VDEV_STATE_OFFLINE,	/* Not allowed to open			*/
+	VDEV_STATE_CANT_OPEN,	/* Tried to open, but failed		*/
+	VDEV_STATE_DEGRADED,	/* Replicated vdev with unhealthy kids	*/
+	VDEV_STATE_HEALTHY	/* Presumed good			*/
+} vdev_state_t;
+
+/*
+ * vdev aux states.  When a vdev is in the CANT_OPEN state, the aux field
+ * of the vdev stats structure uses these constants to distinguish why.
+ */
+typedef enum vdev_aux {
+	VDEV_AUX_NONE,		/* no error				*/
+	VDEV_AUX_OPEN_FAILED,	/* ldi_open_*() or vn_open() failed	*/
+	VDEV_AUX_CORRUPT_DATA,	/* bad label or disk contents		*/
+	VDEV_AUX_NO_REPLICAS,	/* insufficient number of replicas	*/
+	VDEV_AUX_BAD_GUID_SUM,	/* vdev guid sum doesn't match		*/
+	VDEV_AUX_TOO_SMALL,	/* vdev size is too small		*/
+	VDEV_AUX_BAD_LABEL,	/* the label is OK but invalid		*/
+	VDEV_AUX_VERSION_NEWER,	/* on-disk version is too new		*/
+	VDEV_AUX_VERSION_OLDER,	/* on-disk version is too old		*/
+	VDEV_AUX_SPARED		/* hot spare used in another pool	*/
+} vdev_aux_t;
+
+/*
+ * pool state.  The following states are written to disk as part of the normal
+ * SPA lifecycle: ACTIVE, EXPORTED, DESTROYED, SPARE.  The remaining states are
+ * software abstractions used at various levels to communicate pool state.
+ */
+typedef enum pool_state {
+	POOL_STATE_ACTIVE = 0,		/* In active use		*/
+	POOL_STATE_EXPORTED,		/* Explicitly exported		*/
+	POOL_STATE_DESTROYED,		/* Explicitly destroyed		*/
+	POOL_STATE_SPARE,		/* Reserved for hot spare use	*/
+	POOL_STATE_UNINITIALIZED,	/* Internal spa_t state		*/
+	POOL_STATE_UNAVAIL,		/* Internal libzfs state	*/
+	POOL_STATE_POTENTIALLY_ACTIVE	/* Internal libzfs state	*/
+} pool_state_t;
+
+/*
+ * The uberblock version is incremented whenever an incompatible on-disk
+ * format change is made to the SPA, DMU, or ZAP.
+ *
+ * Note: the first two fields should never be moved.  When a storage pool
+ * is opened, the uberblock must be read off the disk before the version
+ * can be checked.  If the ub_version field is moved, we may not detect
+ * version mismatch.  If the ub_magic field is moved, applications that
+ * expect the magic number in the first word won't work.
+ */
+#define	UBERBLOCK_MAGIC		0x00bab10c		/* oo-ba-bloc!	*/
+#define	UBERBLOCK_SHIFT		10			/* up to 1K	*/
+
+struct uberblock {
+	uint64_t	ub_magic;	/* UBERBLOCK_MAGIC		*/
+	uint64_t	ub_version;	/* ZFS_VERSION			*/
+	uint64_t	ub_txg;		/* txg of last sync		*/
+	uint64_t	ub_guid_sum;	/* sum of all vdev guids	*/
+	uint64_t	ub_timestamp;	/* UTC time of last sync	*/
+	blkptr_t	ub_rootbp;	/* MOS objset_phys_t		*/
+};
+
+/*
+ * Flags.
+ */
+#define	DNODE_MUST_BE_ALLOCATED	1
+#define	DNODE_MUST_BE_FREE	2
+
+/*
+ * Fixed constants.
+ */
+#define	DNODE_SHIFT		9	/* 512 bytes */
+#define	DN_MIN_INDBLKSHIFT	10	/* 1k */
+#define	DN_MAX_INDBLKSHIFT	14	/* 16k */
+#define	DNODE_BLOCK_SHIFT	14	/* 16k */
+#define	DNODE_CORE_SIZE		64	/* 64 bytes for dnode sans blkptrs */
+#define	DN_MAX_OBJECT_SHIFT	48	/* 256 trillion (zfs_fid_t limit) */
+#define	DN_MAX_OFFSET_SHIFT	64	/* 2^64 bytes in a dnode */
+
+/*
+ * Derived constants.
+ */
+#define	DNODE_SIZE	(1 << DNODE_SHIFT)
+#define	DN_MAX_NBLKPTR	((DNODE_SIZE - DNODE_CORE_SIZE) >> SPA_BLKPTRSHIFT)
+#define	DN_MAX_BONUSLEN	(DNODE_SIZE - DNODE_CORE_SIZE - (1 << SPA_BLKPTRSHIFT))
+#define	DN_MAX_OBJECT	(1ULL << DN_MAX_OBJECT_SHIFT)
+
+#define	DNODES_PER_BLOCK_SHIFT	(DNODE_BLOCK_SHIFT - DNODE_SHIFT)
+#define	DNODES_PER_BLOCK	(1ULL << DNODES_PER_BLOCK_SHIFT)
+#define	DNODES_PER_LEVEL_SHIFT	(DN_MAX_INDBLKSHIFT - SPA_BLKPTRSHIFT)
+
+/* The +2 here is a cheesy way to round up */
+#define	DN_MAX_LEVELS	(2 + ((DN_MAX_OFFSET_SHIFT - SPA_MINBLOCKSHIFT) / \
+	(DN_MIN_INDBLKSHIFT - SPA_BLKPTRSHIFT)))
+
+#define	DN_BONUS(dnp)	((void*)((dnp)->dn_bonus + \
+	(((dnp)->dn_nblkptr - 1) * sizeof (blkptr_t))))
+
+#define	DN_USED_BYTES(dnp) (((dnp)->dn_flags & DNODE_FLAG_USED_BYTES) ? \
+	(dnp)->dn_used : (dnp)->dn_used << SPA_MINBLOCKSHIFT)
+
+#define	EPB(blkshift, typeshift)	(1 << (blkshift - typeshift))
+
+/* Is dn_used in bytes?  if not, it's in multiples of SPA_MINBLOCKSIZE */
+#define	DNODE_FLAG_USED_BYTES	(1<<0)
+
+typedef struct dnode_phys {
+	uint8_t dn_type;		/* dmu_object_type_t */
+	uint8_t dn_indblkshift;		/* ln2(indirect block size) */
+	uint8_t dn_nlevels;		/* 1=dn_blkptr->data blocks */
+	uint8_t dn_nblkptr;		/* length of dn_blkptr */
+	uint8_t dn_bonustype;		/* type of data in bonus buffer */
+	uint8_t	dn_checksum;		/* ZIO_CHECKSUM type */
+	uint8_t	dn_compress;		/* ZIO_COMPRESS type */
+	uint8_t dn_flags;		/* DNODE_FLAG_* */
+	uint16_t dn_datablkszsec;	/* data block size in 512b sectors */
+	uint16_t dn_bonuslen;		/* length of dn_bonus */
+	uint8_t dn_pad2[4];
+
+	/* accounting is protected by dn_dirty_mtx */
+	uint64_t dn_maxblkid;		/* largest allocated block ID */
+	uint64_t dn_used;		/* bytes (or sectors) of disk space */
+
+	uint64_t dn_pad3[4];
+
+	blkptr_t dn_blkptr[1];
+	uint8_t dn_bonus[DN_MAX_BONUSLEN];
+} dnode_phys_t;
+
+typedef enum dmu_object_type {
+	DMU_OT_NONE,
+	/* general: */
+	DMU_OT_OBJECT_DIRECTORY,	/* ZAP */
+	DMU_OT_OBJECT_ARRAY,		/* UINT64 */
+	DMU_OT_PACKED_NVLIST,		/* UINT8 (XDR by nvlist_pack/unpack) */
+	DMU_OT_PACKED_NVLIST_SIZE,	/* UINT64 */
+	DMU_OT_BPLIST,			/* UINT64 */
+	DMU_OT_BPLIST_HDR,		/* UINT64 */
+	/* spa: */
+	DMU_OT_SPACE_MAP_HEADER,	/* UINT64 */
+	DMU_OT_SPACE_MAP,		/* UINT64 */
+	/* zil: */
+	DMU_OT_INTENT_LOG,		/* UINT64 */
+	/* dmu: */
+	DMU_OT_DNODE,			/* DNODE */
+	DMU_OT_OBJSET,			/* OBJSET */
+	/* dsl: */
+	DMU_OT_DSL_DIR,			/* UINT64 */
+	DMU_OT_DSL_DIR_CHILD_MAP,	/* ZAP */
+	DMU_OT_DSL_DS_SNAP_MAP,		/* ZAP */
+	DMU_OT_DSL_PROPS,		/* ZAP */
+	DMU_OT_DSL_DATASET,		/* UINT64 */
+	/* zpl: */
+	DMU_OT_ZNODE,			/* ZNODE */
+	DMU_OT_ACL,			/* ACL */
+	DMU_OT_PLAIN_FILE_CONTENTS,	/* UINT8 */
+	DMU_OT_DIRECTORY_CONTENTS,	/* ZAP */
+	DMU_OT_MASTER_NODE,		/* ZAP */
+	DMU_OT_UNLINKED_SET,		/* ZAP */
+	/* zvol: */
+	DMU_OT_ZVOL,			/* UINT8 */
+	DMU_OT_ZVOL_PROP,		/* ZAP */
+	/* other; for testing only! */
+	DMU_OT_PLAIN_OTHER,		/* UINT8 */
+	DMU_OT_UINT64_OTHER,		/* UINT64 */
+	DMU_OT_ZAP_OTHER,		/* ZAP */
+	/* new object types: */
+	DMU_OT_ERROR_LOG,		/* ZAP */
+	DMU_OT_SPA_HISTORY,		/* UINT8 */
+	DMU_OT_SPA_HISTORY_OFFSETS,	/* spa_his_phys_t */
+	DMU_OT_POOL_PROPS,		/* ZAP */
+
+	DMU_OT_NUMTYPES
+} dmu_object_type_t;
+
+typedef enum dmu_objset_type {
+	DMU_OST_NONE,
+	DMU_OST_META,
+	DMU_OST_ZFS,
+	DMU_OST_ZVOL,
+	DMU_OST_OTHER,			/* For testing only! */
+	DMU_OST_ANY,			/* Be careful! */
+	DMU_OST_NUMTYPES
+} dmu_objset_type_t;
+
+/*
+ * Intent log header - this on disk structure holds fields to manage
+ * the log.  All fields are 64 bit to easily handle cross architectures.
+ */
+typedef struct zil_header {
+	uint64_t zh_claim_txg;	/* txg in which log blocks were claimed */
+	uint64_t zh_replay_seq;	/* highest replayed sequence number */
+	blkptr_t zh_log;	/* log chain */
+	uint64_t zh_claim_seq;	/* highest claimed sequence number */
+	uint64_t zh_pad[5];
+} zil_header_t;
+
+typedef struct objset_phys {
+	dnode_phys_t os_meta_dnode;
+	zil_header_t os_zil_header;
+	uint64_t os_type;
+	char os_pad[1024 - sizeof (dnode_phys_t) - sizeof (zil_header_t) -
+	    sizeof (uint64_t)];
+} objset_phys_t;
+
+typedef struct dsl_dir_phys {
+	uint64_t dd_creation_time; /* not actually used */
+	uint64_t dd_head_dataset_obj;
+	uint64_t dd_parent_obj;
+	uint64_t dd_clone_parent_obj;
+	uint64_t dd_child_dir_zapobj;
+	/*
+	 * how much space our children are accounting for; for leaf
+	 * datasets, == physical space used by fs + snaps
+	 */
+	uint64_t dd_used_bytes;
+	uint64_t dd_compressed_bytes;
+	uint64_t dd_uncompressed_bytes;
+	/* Administrative quota setting */
+	uint64_t dd_quota;
+	/* Administrative reservation setting */
+	uint64_t dd_reserved;
+	uint64_t dd_props_zapobj;
+	uint64_t dd_pad[21]; /* pad out to 256 bytes for good measure */
+} dsl_dir_phys_t;
+
+typedef struct dsl_dataset_phys {
+	uint64_t ds_dir_obj;
+	uint64_t ds_prev_snap_obj;
+	uint64_t ds_prev_snap_txg;
+	uint64_t ds_next_snap_obj;
+	uint64_t ds_snapnames_zapobj;	/* zap obj of snaps; ==0 for snaps */
+	uint64_t ds_num_children;	/* clone/snap children; ==0 for head */
+	uint64_t ds_creation_time;	/* seconds since 1970 */
+	uint64_t ds_creation_txg;
+	uint64_t ds_deadlist_obj;
+	uint64_t ds_used_bytes;
+	uint64_t ds_compressed_bytes;
+	uint64_t ds_uncompressed_bytes;
+	uint64_t ds_unique_bytes;	/* only relevant to snapshots */
+	/*
+	 * The ds_fsid_guid is a 56-bit ID that can change to avoid
+	 * collisions.  The ds_guid is a 64-bit ID that will never
+	 * change, so there is a small probability that it will collide.
+	 */
+	uint64_t ds_fsid_guid;
+	uint64_t ds_guid;
+	uint64_t ds_flags;
+	blkptr_t ds_bp;
+	uint64_t ds_pad[8]; /* pad out to 320 bytes for good measure */
+} dsl_dataset_phys_t;
+
+/*
+ * The names of zap entries in the DIRECTORY_OBJECT of the MOS.
+ */
+#define	DMU_POOL_DIRECTORY_OBJECT	1
+#define	DMU_POOL_CONFIG			"config"
+#define	DMU_POOL_ROOT_DATASET		"root_dataset"
+#define	DMU_POOL_SYNC_BPLIST		"sync_bplist"
+#define	DMU_POOL_ERRLOG_SCRUB		"errlog_scrub"
+#define	DMU_POOL_ERRLOG_LAST		"errlog_last"
+#define	DMU_POOL_SPARES			"spares"
+#define	DMU_POOL_DEFLATE		"deflate"
+#define	DMU_POOL_HISTORY		"history"
+#define	DMU_POOL_PROPS			"pool_props"
+
+#define	ZAP_MAGIC 0x2F52AB2ABULL
+
+#define	FZAP_BLOCK_SHIFT(zap)	((zap)->zap_block_shift)
+
+#define	ZAP_MAXCD		(uint32_t)(-1)
+#define	ZAP_HASHBITS		28
+#define	MZAP_ENT_LEN		64
+#define	MZAP_NAME_LEN		(MZAP_ENT_LEN - 8 - 4 - 2)
+#define	MZAP_MAX_BLKSHIFT	SPA_MAXBLOCKSHIFT
+#define	MZAP_MAX_BLKSZ		(1 << MZAP_MAX_BLKSHIFT)
+
+typedef struct mzap_ent_phys {
+	uint64_t mze_value;
+	uint32_t mze_cd;
+	uint16_t mze_pad;	/* in case we want to chain them someday */
+	char mze_name[MZAP_NAME_LEN];
+} mzap_ent_phys_t;
+
+typedef struct mzap_phys {
+	uint64_t mz_block_type;	/* ZBT_MICRO */
+	uint64_t mz_salt;
+	uint64_t mz_pad[6];
+	mzap_ent_phys_t mz_chunk[1];
+	/* actually variable size depending on block size */
+} mzap_phys_t;
+
+/*
+ * The (fat) zap is stored in one object. It is an array of
+ * 1<<FZAP_BLOCK_SHIFT byte blocks. The layout looks like one of:
+ *
+ * ptrtbl fits in first block:
+ * 	[zap_phys_t zap_ptrtbl_shift < 6] [zap_leaf_t] ...
+ *
+ * ptrtbl too big for first block:
+ * 	[zap_phys_t zap_ptrtbl_shift >= 6] [zap_leaf_t] [ptrtbl] ...
+ *
+ */
+
+#define	ZBT_LEAF		((1ULL << 63) + 0)
+#define	ZBT_HEADER		((1ULL << 63) + 1)
+#define	ZBT_MICRO		((1ULL << 63) + 3)
+/* any other values are ptrtbl blocks */
+
+/*
+ * the embedded pointer table takes up half a block:
+ * block size / entry size (2^3) / 2
+ */
+#define	ZAP_EMBEDDED_PTRTBL_SHIFT(zap) (FZAP_BLOCK_SHIFT(zap) - 3 - 1)
+
+/*
+ * The embedded pointer table starts half-way through the block.  Since
+ * the pointer table itself is half the block, it starts at (64-bit)
+ * word number (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap)).
+ */
+#define	ZAP_EMBEDDED_PTRTBL_ENT(zap, idx) \
+	((uint64_t *)(zap)->zap_phys) \
+	[(idx) + (1<<ZAP_EMBEDDED_PTRTBL_SHIFT(zap))]
+
+/*
+ * TAKE NOTE:
+ * If zap_phys_t is modified, zap_byteswap() must be modified.
+ */
+typedef struct zap_phys {
+	uint64_t zap_block_type;	/* ZBT_HEADER */
+	uint64_t zap_magic;		/* ZAP_MAGIC */
+
+	struct zap_table_phys {
+		uint64_t zt_blk;	/* starting block number */
+		uint64_t zt_numblks;	/* number of blocks */
+		uint64_t zt_shift;	/* bits to index it */
+		uint64_t zt_nextblk;	/* next (larger) copy start block */
+		uint64_t zt_blks_copied; /* number source blocks copied */
+	} zap_ptrtbl;
+
+	uint64_t zap_freeblk;		/* the next free block */
+	uint64_t zap_num_leafs;		/* number of leafs */
+	uint64_t zap_num_entries;	/* number of entries */
+	uint64_t zap_salt;		/* salt to stir into hash function */
+	/*
+	 * This structure is followed by padding, and then the embedded
+	 * pointer table.  The embedded pointer table takes up second
+	 * half of the block.  It is accessed using the
+	 * ZAP_EMBEDDED_PTRTBL_ENT() macro.
+	 */
+} zap_phys_t;
+
+typedef struct zap_table_phys zap_table_phys_t;
+
+typedef struct fat_zap {
+	int zap_block_shift;			/* block size shift */
+	zap_phys_t *zap_phys;
+} fat_zap_t;
+
+#define	ZAP_LEAF_MAGIC 0x2AB1EAF
+
+/* chunk size = 24 bytes */
+#define	ZAP_LEAF_CHUNKSIZE 24
+
+/*
+ * The amount of space available for chunks is:
+ * block size (1<<l->l_bs) - hash entry size (2) * number of hash
+ * entries - header space (2*chunksize)
+ */
+#define	ZAP_LEAF_NUMCHUNKS(l) \
+	(((1<<(l)->l_bs) - 2*ZAP_LEAF_HASH_NUMENTRIES(l)) / \
+	ZAP_LEAF_CHUNKSIZE - 2)
+
+/*
+ * The amount of space within the chunk available for the array is:
+ * chunk size - space for type (1) - space for next pointer (2)
+ */
+#define	ZAP_LEAF_ARRAY_BYTES (ZAP_LEAF_CHUNKSIZE - 3)
+
+#define	ZAP_LEAF_ARRAY_NCHUNKS(bytes) \
+	(((bytes)+ZAP_LEAF_ARRAY_BYTES-1)/ZAP_LEAF_ARRAY_BYTES)
+
+/*
+ * Low water mark:  when there are only this many chunks free, start
+ * growing the ptrtbl.  Ideally, this should be larger than a
+ * "reasonably-sized" entry.  20 chunks is more than enough for the
+ * largest directory entry (MAXNAMELEN (256) byte name, 8-byte value),
+ * while still being only around 3% for 16k blocks.
+ */
+#define	ZAP_LEAF_LOW_WATER (20)
+
+/*
+ * The leaf hash table has block size / 2^5 (32) number of entries,
+ * which should be more than enough for the maximum number of entries,
+ * which is less than block size / CHUNKSIZE (24) / minimum number of
+ * chunks per entry (3).
+ */
+#define	ZAP_LEAF_HASH_SHIFT(l) ((l)->l_bs - 5)
+#define	ZAP_LEAF_HASH_NUMENTRIES(l) (1 << ZAP_LEAF_HASH_SHIFT(l))
+
+/*
+ * The chunks start immediately after the hash table.  The end of the
+ * hash table is at l_hash + HASH_NUMENTRIES, which we simply cast to a
+ * chunk_t.
+ */
+#define	ZAP_LEAF_CHUNK(l, idx) \
+	((zap_leaf_chunk_t *) \
+	((l)->l_phys->l_hash + ZAP_LEAF_HASH_NUMENTRIES(l)))[idx]
+#define	ZAP_LEAF_ENTRY(l, idx) (&ZAP_LEAF_CHUNK(l, idx).l_entry)
+
+typedef enum zap_chunk_type {
+	ZAP_CHUNK_FREE = 253,
+	ZAP_CHUNK_ENTRY = 252,
+	ZAP_CHUNK_ARRAY = 251,
+	ZAP_CHUNK_TYPE_MAX = 250
+} zap_chunk_type_t;
+
+/*
+ * TAKE NOTE:
+ * If zap_leaf_phys_t is modified, zap_leaf_byteswap() must be modified.
+ */
+typedef struct zap_leaf_phys {
+	struct zap_leaf_header {
+		uint64_t lh_block_type;		/* ZBT_LEAF */
+		uint64_t lh_pad1;
+		uint64_t lh_prefix;		/* hash prefix of this leaf */
+		uint32_t lh_magic;		/* ZAP_LEAF_MAGIC */
+		uint16_t lh_nfree;		/* number free chunks */
+		uint16_t lh_nentries;		/* number of entries */
+		uint16_t lh_prefix_len;		/* num bits used to id this */
+
+/* above is accessable to zap, below is zap_leaf private */
+
+		uint16_t lh_freelist;		/* chunk head of free list */
+		uint8_t lh_pad2[12];
+	} l_hdr; /* 2 24-byte chunks */
+
+	/*
+	 * The header is followed by a hash table with
+	 * ZAP_LEAF_HASH_NUMENTRIES(zap) entries.  The hash table is
+	 * followed by an array of ZAP_LEAF_NUMCHUNKS(zap)
+	 * zap_leaf_chunk structures.  These structures are accessed
+	 * with the ZAP_LEAF_CHUNK() macro.
+	 */
+
+	uint16_t l_hash[1];
+} zap_leaf_phys_t;
+
+typedef union zap_leaf_chunk {
+	struct zap_leaf_entry {
+		uint8_t le_type; 		/* always ZAP_CHUNK_ENTRY */
+		uint8_t le_int_size;		/* size of ints */
+		uint16_t le_next;		/* next entry in hash chain */
+		uint16_t le_name_chunk;		/* first chunk of the name */
+		uint16_t le_name_length;	/* bytes in name, incl null */
+		uint16_t le_value_chunk;	/* first chunk of the value */
+		uint16_t le_value_length;	/* value length in ints */
+		uint32_t le_cd;			/* collision differentiator */
+		uint64_t le_hash;		/* hash value of the name */
+	} l_entry;
+	struct zap_leaf_array {
+		uint8_t la_type;		/* always ZAP_CHUNK_ARRAY */
+		uint8_t la_array[ZAP_LEAF_ARRAY_BYTES];
+		uint16_t la_next;		/* next blk or CHAIN_END */
+	} l_array;
+	struct zap_leaf_free {
+		uint8_t lf_type;		/* always ZAP_CHUNK_FREE */
+		uint8_t lf_pad[ZAP_LEAF_ARRAY_BYTES];
+		uint16_t lf_next;	/* next in free list, or CHAIN_END */
+	} l_free;
+} zap_leaf_chunk_t;
+
+typedef struct zap_leaf {
+	int l_bs;			/* block size shift */
+	zap_leaf_phys_t *l_phys;
+} zap_leaf_t;
+
+/*
+ * Define special zfs pflags
+ */
+#define	ZFS_XATTR	0x1		/* is an extended attribute */
+#define	ZFS_INHERIT_ACE	0x2		/* ace has inheritable ACEs */
+#define	ZFS_ACL_TRIVIAL 0x4		/* files ACL is trivial */
+
+#define	MASTER_NODE_OBJ	1
+
+/*
+ * special attributes for master node.
+ */
+
+#define	ZFS_FSID		"FSID"
+#define	ZFS_UNLINKED_SET	"DELETE_QUEUE"
+#define	ZFS_ROOT_OBJ		"ROOT"
+#define	ZPL_VERSION_OBJ		"VERSION"
+#define	ZFS_PROP_BLOCKPERPAGE	"BLOCKPERPAGE"
+#define	ZFS_PROP_NOGROWBLOCKS	"NOGROWBLOCKS"
+
+#define	ZFS_FLAG_BLOCKPERPAGE	0x1
+#define	ZFS_FLAG_NOGROWBLOCKS	0x2
+
+/*
+ * ZPL version - rev'd whenever an incompatible on-disk format change
+ * occurs.  Independent of SPA/DMU/ZAP versioning.
+ */
+
+#define	ZPL_VERSION		1ULL
+
+/*
+ * The directory entry has the type (currently unused on Solaris) in the
+ * top 4 bits, and the object number in the low 48 bits.  The "middle"
+ * 12 bits are unused.
+ */
+#define	ZFS_DIRENT_TYPE(de) BF64_GET(de, 60, 4)
+#define	ZFS_DIRENT_OBJ(de) BF64_GET(de, 0, 48)
+#define	ZFS_DIRENT_MAKE(type, obj) (((uint64_t)type << 60) | obj)
+
+typedef struct ace {
+	uid_t		a_who;		/* uid or gid */
+	uint32_t	a_access_mask;	/* read,write,... */
+	uint16_t	a_flags;	/* see below */
+	uint16_t	a_type;		/* allow or deny */
+} ace_t;
+
+#define ACE_SLOT_CNT	6
+
+typedef struct zfs_znode_acl {
+	uint64_t	z_acl_extern_obj;	  /* ext acl pieces */
+	uint32_t	z_acl_count;		  /* Number of ACEs */
+	uint16_t	z_acl_version;		  /* acl version */
+	uint16_t	z_acl_pad;		  /* pad */
+	ace_t		z_ace_data[ACE_SLOT_CNT]; /* 6 standard ACEs */
+} zfs_znode_acl_t;
+
+/*
+ * This is the persistent portion of the znode.  It is stored
+ * in the "bonus buffer" of the file.  Short symbolic links
+ * are also stored in the bonus buffer.
+ */
+typedef struct znode_phys {
+	uint64_t zp_atime[2];		/*  0 - last file access time */
+	uint64_t zp_mtime[2];		/* 16 - last file modification time */
+	uint64_t zp_ctime[2];		/* 32 - last file change time */
+	uint64_t zp_crtime[2];		/* 48 - creation time */
+	uint64_t zp_gen;		/* 64 - generation (txg of creation) */
+	uint64_t zp_mode;		/* 72 - file mode bits */
+	uint64_t zp_size;		/* 80 - size of file */
+	uint64_t zp_parent;		/* 88 - directory parent (`..') */
+	uint64_t zp_links;		/* 96 - number of links to file */
+	uint64_t zp_xattr;		/* 104 - DMU object for xattrs */
+	uint64_t zp_rdev;		/* 112 - dev_t for VBLK & VCHR files */
+	uint64_t zp_flags;		/* 120 - persistent flags */
+	uint64_t zp_uid;		/* 128 - file owner */
+	uint64_t zp_gid;		/* 136 - owning group */
+	uint64_t zp_pad[4];		/* 144 - future */
+	zfs_znode_acl_t zp_acl;		/* 176 - 263 ACL */
+	/*
+	 * Data may pad out any remaining bytes in the znode buffer, eg:
+	 *
+	 * |<---------------------- dnode_phys (512) ------------------------>|
+	 * |<-- dnode (192) --->|<----------- "bonus" buffer (320) ---------->|
+	 *			|<---- znode (264) ---->|<---- data (56) ---->|
+	 *
+	 * At present, we only use this space to store symbolic links.
+	 */
+} znode_phys_t;
+
+/*
+ * In-core vdev representation.
+ */
+struct vdev;
+typedef int vdev_read_t(struct vdev *vdev, void *priv, off_t offset, void *buf, size_t bytes);
+
+typedef STAILQ_HEAD(vdev_list, vdev) vdev_list_t;
+
+typedef struct vdev {
+	STAILQ_ENTRY(vdev) v_childlink;	/* link in parent's child list */
+	STAILQ_ENTRY(vdev) v_alllink;	/* link in global vdev list */
+	vdev_list_t	v_children;	/* children of this vdev */
+	char		*v_name;	/* vdev name */
+	uint64_t	v_guid;		/* vdev guid */
+	int		v_id;		/* index in parent */
+	vdev_state_t	v_state;	/* current state */
+	vdev_read_t	*v_read;	/* function to read from this vdev */
+	void		*v_read_priv;	/* private data for read function */
+} vdev_t;
+
+/*
+ * In-core pool representation.
+ */
+typedef STAILQ_HEAD(spa_list, spa) spa_list_t;
+
+typedef struct spa {
+	STAILQ_ENTRY(spa) spa_link;	/* link in global pool list */
+	char		*spa_name;	/* pool name */
+	uint64_t	spa_guid;	/* pool guid */
+	uint64_t	spa_txg;	/* most recent transaction */
+	struct uberblock spa_uberblock;	/* best uberblock so far */
+	vdev_list_t	spa_vdevs;	/* list of all toplevel vdevs */
+	objset_phys_t	spa_mos;	/* MOS for this pool */
+	objset_phys_t	spa_root_objset; /* current mounted ZPL objset */
+} spa_t;
diff --git a/sys/cddl/boot/zfs/zfssubr.c b/sys/cddl/boot/zfs/zfssubr.c
new file mode 100644
index 0000000..1c859c0
--- /dev/null
+++ b/sys/cddl/boot/zfs/zfssubr.c
@@ -0,0 +1,193 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+/*
+ * Copyright 2007 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+static uint64_t zfs_crc64_table[256];
+
+static void
+zfs_init_crc(void)
+{
+	int i, j;
+	uint64_t *ct;
+
+	/*
+	 * Calculate the crc64 table (used for the zap hash
+	 * function).
+	 */
+	if (zfs_crc64_table[128] != ZFS_CRC64_POLY) {
+		memset(zfs_crc64_table, 0, sizeof(zfs_crc64_table));
+		for (i = 0; i < 256; i++)
+			for (ct = zfs_crc64_table + i, *ct = i, j = 8; j > 0; j--)
+				*ct = (*ct >> 1) ^ (-(*ct & 1) & ZFS_CRC64_POLY);
+	}
+}
+
+static void
+zio_checksum_off(const void *buf, uint64_t size, zio_cksum_t *zcp)
+{
+	ZIO_SET_CHECKSUM(zcp, 0, 0, 0, 0);
+}
+
+/*
+ * Signature for checksum functions.
+ */
+typedef void zio_checksum_t(const void *data, uint64_t size, zio_cksum_t *zcp);
+
+/*
+ * Information about each checksum function.
+ */
+typedef struct zio_checksum_info {
+	zio_checksum_t	*ci_func[2]; /* checksum function for each byteorder */
+	int		ci_correctable;	/* number of correctable bits	*/
+	int		ci_zbt;		/* uses zio block tail?	*/
+	const char	*ci_name;	/* descriptive name */
+} zio_checksum_info_t;
+
+#include "fletcher.c"
+#include "sha256.c"
+
+static zio_checksum_info_t zio_checksum_table[ZIO_CHECKSUM_FUNCTIONS] = {
+	{{NULL,			NULL},			0, 0,	"inherit"},
+	{{NULL,			NULL},			0, 0,	"on"},
+	{{zio_checksum_off,	zio_checksum_off},	0, 0,	"off"},
+	{{zio_checksum_SHA256,	NULL},			1, 1,	"label"},
+	{{zio_checksum_SHA256,	NULL},			1, 1,	"gang_header"},
+	{{fletcher_2_native,	NULL},			0, 1,	"zilog"},
+	{{fletcher_2_native,	NULL},			0, 0,	"fletcher2"},
+	{{fletcher_4_native,	NULL},			1, 0,	"fletcher4"},
+	{{zio_checksum_SHA256,	NULL},			1, 0,	"SHA256"},
+};
+
+/*
+ * Common signature for all zio compress/decompress functions.
+ */
+typedef size_t zio_compress_func_t(void *src, void *dst,
+    size_t s_len, size_t d_len, int);
+typedef int zio_decompress_func_t(void *src, void *dst,
+    size_t s_len, size_t d_len, int);
+
+/*
+ * Information about each compression function.
+ */
+typedef struct zio_compress_info {
+	zio_compress_func_t	*ci_compress;	/* compression function */
+	zio_decompress_func_t	*ci_decompress;	/* decompression function */
+	int			ci_level;	/* level parameter */
+	const char		*ci_name;	/* algorithm name */
+} zio_compress_info_t;
+
+#include "lzjb.c"
+
+/*
+ * Compression vectors.
+ */
+static zio_compress_info_t zio_compress_table[ZIO_COMPRESS_FUNCTIONS] = {
+	{NULL,			NULL,			0,	"inherit"},
+	{NULL,			NULL,			0,	"on"},
+	{NULL,			NULL,			0,	"uncompressed"},
+	{NULL,			lzjb_decompress,	0,	"lzjb"},
+	{NULL,			NULL,			0,	"empty"},
+	{NULL,			NULL,			1,	"gzip-1"},
+	{NULL,			NULL,			2,	"gzip-2"},
+	{NULL,			NULL,			3,	"gzip-3"},
+	{NULL,			NULL,			4,	"gzip-4"},
+	{NULL,			NULL,			5,	"gzip-5"},
+	{NULL,			NULL,			6,	"gzip-6"},
+	{NULL,			NULL,			7,	"gzip-7"},
+	{NULL,			NULL,			8,	"gzip-8"},
+	{NULL,			NULL,			9,	"gzip-9"},
+};
+
+static int
+zio_checksum_error(const blkptr_t *bp, void *data)
+{
+	zio_cksum_t zc = bp->blk_cksum;
+	unsigned int checksum = BP_GET_CHECKSUM(bp);
+	uint64_t size = BP_GET_PSIZE(bp);
+	zio_block_tail_t *zbt = (zio_block_tail_t *)((char *)data + size) - 1;
+	zio_checksum_info_t *ci = &zio_checksum_table[checksum];
+	zio_cksum_t actual_cksum, expected_cksum;
+
+	if (checksum >= ZIO_CHECKSUM_FUNCTIONS || ci->ci_func[0] == NULL)
+		return (EINVAL);
+
+	if (ci->ci_zbt) {
+		expected_cksum = zbt->zbt_cksum;
+		zbt->zbt_cksum = zc;
+		ci->ci_func[0](data, size, &actual_cksum);
+		zbt->zbt_cksum = expected_cksum;
+		zc = expected_cksum;
+	} else {
+		/* ASSERT(!BP_IS_GANG(bp)); */
+		ci->ci_func[0](data, size, &actual_cksum);
+	}
+
+	if (!ZIO_CHECKSUM_EQUAL(actual_cksum, zc)) {
+		/*printf("ZFS: read checksum failed\n");*/
+		return (EIO);
+	}
+
+	return (0);
+}
+
+static int
+zio_decompress_data(int cpfunc, void *src, uint64_t srcsize,
+	void *dest, uint64_t destsize)
+{
+	zio_compress_info_t *ci = &zio_compress_table[cpfunc];
+
+	/* ASSERT((uint_t)cpfunc < ZIO_COMPRESS_FUNCTIONS); */
+	if (!ci->ci_decompress) {
+		printf("ZFS: unsupported compression algorithm %d\n", cpfunc);
+		return (EIO);
+	}
+
+	return (ci->ci_decompress(src, dest, srcsize, destsize, ci->ci_level));
+}
+
+static uint64_t
+zap_hash(uint64_t salt, const char *name)
+{
+	const uint8_t *cp;
+	uint8_t c;
+	uint64_t crc = salt;
+
+	/*ASSERT(crc != 0);*/
+	/*ASSERT(zfs_crc64_table[128] == ZFS_CRC64_POLY);*/
+	for (cp = (const uint8_t *)name; (c = *cp) != '\0'; cp++)
+		crc = (crc >> 8) ^ zfs_crc64_table[(crc ^ c) & 0xFF];
+
+	/*
+	 * Only use 28 bits, since we need 4 bits in the cookie for the
+	 * collision differentiator.  We MUST use the high bits, since
+	 * those are the onces that we first pay attention to when
+	 * chosing the bucket.
+	 */
+	crc &= ~((1ULL << (64 - ZAP_HASHBITS)) - 1);
+
+	return (crc);
+}