Move the world out of /zfs/ and seperate out module build tree

1 files changed, 638 insertions, 0 deletions

diff --git a/module/zfs/include/sys/dmu.h b/module/zfs/include/sys/dmu.h
new file mode 100644
index 000000000..3b1e5c8fb
--- /dev/null
+++ b/module/zfs/include/sys/dmu.h
@@ -0,0 +1,638 @@
+/*
+ * 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 2008 Sun Microsystems, Inc.  All rights reserved.
+ * Use is subject to license terms.
+ */
+
+#ifndef	_SYS_DMU_H
+#define	_SYS_DMU_H
+
+/*
+ * This file describes the interface that the DMU provides for its
+ * consumers.
+ *
+ * The DMU also interacts with the SPA.  That interface is described in
+ * dmu_spa.h.
+ */
+
+#include <sys/inttypes.h>
+#include <sys/types.h>
+#include <sys/param.h>
+#include <sys/cred.h>
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+struct uio;
+struct page;
+struct vnode;
+struct spa;
+struct zilog;
+struct zio;
+struct blkptr;
+struct zap_cursor;
+struct dsl_dataset;
+struct dsl_pool;
+struct dnode;
+struct drr_begin;
+struct drr_end;
+struct zbookmark;
+struct spa;
+struct nvlist;
+struct objset_impl;
+
+typedef struct objset objset_t;
+typedef struct dmu_tx dmu_tx_t;
+typedef struct dsl_dir dsl_dir_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_OLDACL,			/* Old 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_DSL_PERMS,		/* ZAP */
+	DMU_OT_ACL,			/* ACL */
+	DMU_OT_SYSACL,			/* SYSACL */
+	DMU_OT_FUID,			/* FUID table (Packed NVLIST UINT8) */
+	DMU_OT_FUID_SIZE,		/* FUID table size UINT64 */
+	DMU_OT_NEXT_CLONES,		/* ZAP */
+	DMU_OT_SCRUB_QUEUE,		/* 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;
+
+void byteswap_uint64_array(void *buf, size_t size);
+void byteswap_uint32_array(void *buf, size_t size);
+void byteswap_uint16_array(void *buf, size_t size);
+void byteswap_uint8_array(void *buf, size_t size);
+void zap_byteswap(void *buf, size_t size);
+void zfs_oldacl_byteswap(void *buf, size_t size);
+void zfs_acl_byteswap(void *buf, size_t size);
+void zfs_znode_byteswap(void *buf, size_t size);
+
+#define	DS_MODE_NOHOLD		0	/* internal use only */
+#define	DS_MODE_USER		1	/* simple access, no special needs */
+#define	DS_MODE_OWNER		2	/* the "main" access, e.g. a mount */
+#define	DS_MODE_TYPE_MASK	0x3
+#define	DS_MODE_TYPE(x)		((x) & DS_MODE_TYPE_MASK)
+#define	DS_MODE_READONLY	0x8
+#define	DS_MODE_IS_READONLY(x)	((x) & DS_MODE_READONLY)
+#define	DS_MODE_INCONSISTENT	0x10
+#define	DS_MODE_IS_INCONSISTENT(x)	((x) & DS_MODE_INCONSISTENT)
+
+#define	DS_FIND_SNAPSHOTS	(1<<0)
+#define	DS_FIND_CHILDREN	(1<<1)
+
+/*
+ * The maximum number of bytes that can be accessed as part of one
+ * operation, including metadata.
+ */
+#define	DMU_MAX_ACCESS (10<<20) /* 10MB */
+#define	DMU_MAX_DELETEBLKCNT (20480) /* ~5MB of indirect blocks */
+
+/*
+ * Public routines to create, destroy, open, and close objsets.
+ */
+int dmu_objset_open(const char *name, dmu_objset_type_t type, int mode,
+    objset_t **osp);
+int dmu_objset_open_ds(struct dsl_dataset *ds, dmu_objset_type_t type,
+    objset_t **osp);
+void dmu_objset_close(objset_t *os);
+int dmu_objset_evict_dbufs(objset_t *os);
+int dmu_objset_create(const char *name, dmu_objset_type_t type,
+    objset_t *clone_parent, uint64_t flags,
+    void (*func)(objset_t *os, void *arg, cred_t *cr, dmu_tx_t *tx), void *arg);
+int dmu_objset_destroy(const char *name);
+int dmu_snapshots_destroy(char *fsname, char *snapname);
+int dmu_objset_rollback(objset_t *os);
+int dmu_objset_snapshot(char *fsname, char *snapname, boolean_t recursive);
+int dmu_objset_rename(const char *name, const char *newname,
+    boolean_t recursive);
+int dmu_objset_find(char *name, int func(char *, void *), void *arg,
+    int flags);
+void dmu_objset_byteswap(void *buf, size_t size);
+
+typedef struct dmu_buf {
+	uint64_t db_object;		/* object that this buffer is part of */
+	uint64_t db_offset;		/* byte offset in this object */
+	uint64_t db_size;		/* size of buffer in bytes */
+	void *db_data;			/* data in buffer */
+} dmu_buf_t;
+
+typedef void dmu_buf_evict_func_t(struct dmu_buf *db, void *user_ptr);
+
+/*
+ * 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	DMU_POOL_L2CACHE		"l2cache"
+
+/* 4x8 zbookmark_t */
+#define	DMU_POOL_SCRUB_BOOKMARK		"scrub_bookmark"
+/* 1x8 zap obj DMU_OT_SCRUB_QUEUE */
+#define	DMU_POOL_SCRUB_QUEUE		"scrub_queue"
+/* 1x8 txg */
+#define	DMU_POOL_SCRUB_MIN_TXG		"scrub_min_txg"
+/* 1x8 txg */
+#define	DMU_POOL_SCRUB_MAX_TXG		"scrub_max_txg"
+/* 1x4 enum scrub_func */
+#define	DMU_POOL_SCRUB_FUNC		"scrub_func"
+/* 1x8 count */
+#define	DMU_POOL_SCRUB_ERRORS		"scrub_errors"
+
+/*
+ * Allocate an object from this objset.  The range of object numbers
+ * available is (0, DN_MAX_OBJECT).  Object 0 is the meta-dnode.
+ *
+ * The transaction must be assigned to a txg.  The newly allocated
+ * object will be "held" in the transaction (ie. you can modify the
+ * newly allocated object in this transaction).
+ *
+ * dmu_object_alloc() chooses an object and returns it in *objectp.
+ *
+ * dmu_object_claim() allocates a specific object number.  If that
+ * number is already allocated, it fails and returns EEXIST.
+ *
+ * Return 0 on success, or ENOSPC or EEXIST as specified above.
+ */
+uint64_t dmu_object_alloc(objset_t *os, dmu_object_type_t ot,
+    int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
+int dmu_object_claim(objset_t *os, uint64_t object, dmu_object_type_t ot,
+    int blocksize, dmu_object_type_t bonus_type, int bonus_len, dmu_tx_t *tx);
+int dmu_object_reclaim(objset_t *os, uint64_t object, dmu_object_type_t ot,
+    int blocksize, dmu_object_type_t bonustype, int bonuslen, dmu_tx_t *tx);
+
+/*
+ * Free an object from this objset.
+ *
+ * The object's data will be freed as well (ie. you don't need to call
+ * dmu_free(object, 0, -1, tx)).
+ *
+ * The object need not be held in the transaction.
+ *
+ * If there are any holds on this object's buffers (via dmu_buf_hold()),
+ * or tx holds on the object (via dmu_tx_hold_object()), you can not
+ * free it; it fails and returns EBUSY.
+ *
+ * If the object is not allocated, it fails and returns ENOENT.
+ *
+ * Return 0 on success, or EBUSY or ENOENT as specified above.
+ */
+int dmu_object_free(objset_t *os, uint64_t object, dmu_tx_t *tx);
+
+/*
+ * Find the next allocated or free object.
+ *
+ * The objectp parameter is in-out.  It will be updated to be the next
+ * object which is allocated.  Ignore objects which have not been
+ * modified since txg.
+ *
+ * XXX Can only be called on a objset with no dirty data.
+ *
+ * Returns 0 on success, or ENOENT if there are no more objects.
+ */
+int dmu_object_next(objset_t *os, uint64_t *objectp,
+    boolean_t hole, uint64_t txg);
+
+/*
+ * Set the data blocksize for an object.
+ *
+ * The object cannot have any blocks allcated beyond the first.  If
+ * the first block is allocated already, the new size must be greater
+ * than the current block size.  If these conditions are not met,
+ * ENOTSUP will be returned.
+ *
+ * Returns 0 on success, or EBUSY if there are any holds on the object
+ * contents, or ENOTSUP as described above.
+ */
+int dmu_object_set_blocksize(objset_t *os, uint64_t object, uint64_t size,
+    int ibs, dmu_tx_t *tx);
+
+/*
+ * Set the checksum property on a dnode.  The new checksum algorithm will
+ * apply to all newly written blocks; existing blocks will not be affected.
+ */
+void dmu_object_set_checksum(objset_t *os, uint64_t object, uint8_t checksum,
+    dmu_tx_t *tx);
+
+/*
+ * Set the compress property on a dnode.  The new compression algorithm will
+ * apply to all newly written blocks; existing blocks will not be affected.
+ */
+void dmu_object_set_compress(objset_t *os, uint64_t object, uint8_t compress,
+    dmu_tx_t *tx);
+
+/*
+ * Decide how many copies of a given block we should make.  Can be from
+ * 1 to SPA_DVAS_PER_BP.
+ */
+int dmu_get_replication_level(struct objset_impl *, struct zbookmark *zb,
+    dmu_object_type_t ot);
+/*
+ * The bonus data is accessed more or less like a regular buffer.
+ * You must dmu_bonus_hold() to get the buffer, which will give you a
+ * dmu_buf_t with db_offset==-1ULL, and db_size = the size of the bonus
+ * data.  As with any normal buffer, you must call dmu_buf_read() to
+ * read db_data, dmu_buf_will_dirty() before modifying it, and the
+ * object must be held in an assigned transaction before calling
+ * dmu_buf_will_dirty.  You may use dmu_buf_set_user() on the bonus
+ * buffer as well.  You must release your hold with dmu_buf_rele().
+ */
+int dmu_bonus_hold(objset_t *os, uint64_t object, void *tag, dmu_buf_t **);
+int dmu_bonus_max(void);
+int dmu_set_bonus(dmu_buf_t *, int, dmu_tx_t *);
+
+/*
+ * Obtain the DMU buffer from the specified object which contains the
+ * specified offset.  dmu_buf_hold() puts a "hold" on the buffer, so
+ * that it will remain in memory.  You must release the hold with
+ * dmu_buf_rele().  You musn't access the dmu_buf_t after releasing your
+ * hold.  You must have a hold on any dmu_buf_t* you pass to the DMU.
+ *
+ * You must call dmu_buf_read, dmu_buf_will_dirty, or dmu_buf_will_fill
+ * on the returned buffer before reading or writing the buffer's
+ * db_data.  The comments for those routines describe what particular
+ * operations are valid after calling them.
+ *
+ * The object number must be a valid, allocated object number.
+ */
+int dmu_buf_hold(objset_t *os, uint64_t object, uint64_t offset,
+    void *tag, dmu_buf_t **);
+void dmu_buf_add_ref(dmu_buf_t *db, void* tag);
+void dmu_buf_rele(dmu_buf_t *db, void *tag);
+uint64_t dmu_buf_refcount(dmu_buf_t *db);
+
+/*
+ * dmu_buf_hold_array holds the DMU buffers which contain all bytes in a
+ * range of an object.  A pointer to an array of dmu_buf_t*'s is
+ * returned (in *dbpp).
+ *
+ * dmu_buf_rele_array releases the hold on an array of dmu_buf_t*'s, and
+ * frees the array.  The hold on the array of buffers MUST be released
+ * with dmu_buf_rele_array.  You can NOT release the hold on each buffer
+ * individually with dmu_buf_rele.
+ */
+int dmu_buf_hold_array_by_bonus(dmu_buf_t *db, uint64_t offset,
+    uint64_t length, int read, void *tag, int *numbufsp, dmu_buf_t ***dbpp);
+void dmu_buf_rele_array(dmu_buf_t **, int numbufs, void *tag);
+
+/*
+ * Returns NULL on success, or the existing user ptr if it's already
+ * been set.
+ *
+ * user_ptr is for use by the user and can be obtained via dmu_buf_get_user().
+ *
+ * user_data_ptr_ptr should be NULL, or a pointer to a pointer which
+ * will be set to db->db_data when you are allowed to access it.  Note
+ * that db->db_data (the pointer) can change when you do dmu_buf_read(),
+ * dmu_buf_tryupgrade(), dmu_buf_will_dirty(), or dmu_buf_will_fill().
+ * *user_data_ptr_ptr will be set to the new value when it changes.
+ *
+ * If non-NULL, pageout func will be called when this buffer is being
+ * excised from the cache, so that you can clean up the data structure
+ * pointed to by user_ptr.
+ *
+ * dmu_evict_user() will call the pageout func for all buffers in a
+ * objset with a given pageout func.
+ */
+void *dmu_buf_set_user(dmu_buf_t *db, void *user_ptr, void *user_data_ptr_ptr,
+    dmu_buf_evict_func_t *pageout_func);
+/*
+ * set_user_ie is the same as set_user, but request immediate eviction
+ * when hold count goes to zero.
+ */
+void *dmu_buf_set_user_ie(dmu_buf_t *db, void *user_ptr,
+    void *user_data_ptr_ptr, dmu_buf_evict_func_t *pageout_func);
+void *dmu_buf_update_user(dmu_buf_t *db_fake, void *old_user_ptr,
+    void *user_ptr, void *user_data_ptr_ptr,
+    dmu_buf_evict_func_t *pageout_func);
+void dmu_evict_user(objset_t *os, dmu_buf_evict_func_t *func);
+
+/*
+ * Returns the user_ptr set with dmu_buf_set_user(), or NULL if not set.
+ */
+void *dmu_buf_get_user(dmu_buf_t *db);
+
+/*
+ * Indicate that you are going to modify the buffer's data (db_data).
+ *
+ * The transaction (tx) must be assigned to a txg (ie. you've called
+ * dmu_tx_assign()).  The buffer's object must be held in the tx
+ * (ie. you've called dmu_tx_hold_object(tx, db->db_object)).
+ */
+void dmu_buf_will_dirty(dmu_buf_t *db, dmu_tx_t *tx);
+
+/*
+ * You must create a transaction, then hold the objects which you will
+ * (or might) modify as part of this transaction.  Then you must assign
+ * the transaction to a transaction group.  Once the transaction has
+ * been assigned, you can modify buffers which belong to held objects as
+ * part of this transaction.  You can't modify buffers before the
+ * transaction has been assigned; you can't modify buffers which don't
+ * belong to objects which this transaction holds; you can't hold
+ * objects once the transaction has been assigned.  You may hold an
+ * object which you are going to free (with dmu_object_free()), but you
+ * don't have to.
+ *
+ * You can abort the transaction before it has been assigned.
+ *
+ * Note that you may hold buffers (with dmu_buf_hold) at any time,
+ * regardless of transaction state.
+ */
+
+#define	DMU_NEW_OBJECT	(-1ULL)
+#define	DMU_OBJECT_END	(-1ULL)
+
+dmu_tx_t *dmu_tx_create(objset_t *os);
+void dmu_tx_hold_write(dmu_tx_t *tx, uint64_t object, uint64_t off, int len);
+void dmu_tx_hold_free(dmu_tx_t *tx, uint64_t object, uint64_t off,
+    uint64_t len);
+void dmu_tx_hold_zap(dmu_tx_t *tx, uint64_t object, int add, char *name);
+void dmu_tx_hold_bonus(dmu_tx_t *tx, uint64_t object);
+void dmu_tx_abort(dmu_tx_t *tx);
+int dmu_tx_assign(dmu_tx_t *tx, uint64_t txg_how);
+void dmu_tx_wait(dmu_tx_t *tx);
+void dmu_tx_commit(dmu_tx_t *tx);
+
+/*
+ * Free up the data blocks for a defined range of a file.  If size is
+ * zero, the range from offset to end-of-file is freed.
+ */
+int dmu_free_range(objset_t *os, uint64_t object, uint64_t offset,
+	uint64_t size, dmu_tx_t *tx);
+int dmu_free_long_range(objset_t *os, uint64_t object, uint64_t offset,
+	uint64_t size);
+int dmu_free_object(objset_t *os, uint64_t object);
+
+/*
+ * Convenience functions.
+ *
+ * Canfail routines will return 0 on success, or an errno if there is a
+ * nonrecoverable I/O error.
+ */
+int dmu_read(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
+	void *buf);
+void dmu_write(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
+	const void *buf, dmu_tx_t *tx);
+void dmu_prealloc(objset_t *os, uint64_t object, uint64_t offset, uint64_t size,
+	dmu_tx_t *tx);
+int dmu_read_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size);
+int dmu_write_uio(objset_t *os, uint64_t object, struct uio *uio, uint64_t size,
+    dmu_tx_t *tx);
+int dmu_write_pages(objset_t *os, uint64_t object, uint64_t offset,
+    uint64_t size, struct page *pp, dmu_tx_t *tx);
+
+extern int zfs_prefetch_disable;
+
+/*
+ * Asynchronously try to read in the data.
+ */
+void dmu_prefetch(objset_t *os, uint64_t object, uint64_t offset,
+    uint64_t len);
+
+typedef struct dmu_object_info {
+	/* All sizes are in bytes. */
+	uint32_t doi_data_block_size;
+	uint32_t doi_metadata_block_size;
+	uint64_t doi_bonus_size;
+	dmu_object_type_t doi_type;
+	dmu_object_type_t doi_bonus_type;
+	uint8_t doi_indirection;		/* 2 = dnode->indirect->data */
+	uint8_t doi_checksum;
+	uint8_t doi_compress;
+	uint8_t doi_pad[5];
+	/* Values below are number of 512-byte blocks. */
+	uint64_t doi_physical_blks;		/* data + metadata */
+	uint64_t doi_max_block_offset;
+} dmu_object_info_t;
+
+typedef void arc_byteswap_func_t(void *buf, size_t size);
+
+typedef struct dmu_object_type_info {
+	arc_byteswap_func_t	*ot_byteswap;
+	boolean_t		ot_metadata;
+	char			*ot_name;
+} dmu_object_type_info_t;
+
+extern const dmu_object_type_info_t dmu_ot[DMU_OT_NUMTYPES];
+
+/*
+ * Get information on a DMU object.
+ *
+ * Return 0 on success or ENOENT if object is not allocated.
+ *
+ * If doi is NULL, just indicates whether the object exists.
+ */
+int dmu_object_info(objset_t *os, uint64_t object, dmu_object_info_t *doi);
+void dmu_object_info_from_dnode(struct dnode *dn, dmu_object_info_t *doi);
+void dmu_object_info_from_db(dmu_buf_t *db, dmu_object_info_t *doi);
+void dmu_object_size_from_db(dmu_buf_t *db, uint32_t *blksize,
+    u_longlong_t *nblk512);
+
+typedef struct dmu_objset_stats {
+	uint64_t dds_num_clones; /* number of clones of this */
+	uint64_t dds_creation_txg;
+	uint64_t dds_guid;
+	dmu_objset_type_t dds_type;
+	uint8_t dds_is_snapshot;
+	uint8_t dds_inconsistent;
+	char dds_origin[MAXNAMELEN];
+} dmu_objset_stats_t;
+
+/*
+ * Get stats on a dataset.
+ */
+void dmu_objset_fast_stat(objset_t *os, dmu_objset_stats_t *stat);
+
+/*
+ * Add entries to the nvlist for all the objset's properties.  See
+ * zfs_prop_table[] and zfs(1m) for details on the properties.
+ */
+void dmu_objset_stats(objset_t *os, struct nvlist *nv);
+
+/*
+ * Get the space usage statistics for statvfs().
+ *
+ * refdbytes is the amount of space "referenced" by this objset.
+ * availbytes is the amount of space available to this objset, taking
+ * into account quotas & reservations, assuming that no other objsets
+ * use the space first.  These values correspond to the 'referenced' and
+ * 'available' properties, described in the zfs(1m) manpage.
+ *
+ * usedobjs and availobjs are the number of objects currently allocated,
+ * and available.
+ */
+void dmu_objset_space(objset_t *os, uint64_t *refdbytesp, uint64_t *availbytesp,
+    uint64_t *usedobjsp, uint64_t *availobjsp);
+
+/*
+ * The fsid_guid is a 56-bit ID that can change to avoid collisions.
+ * (Contrast with the ds_guid which is a 64-bit ID that will never
+ * change, so there is a small probability that it will collide.)
+ */
+uint64_t dmu_objset_fsid_guid(objset_t *os);
+
+int dmu_objset_is_snapshot(objset_t *os);
+
+extern struct spa *dmu_objset_spa(objset_t *os);
+extern struct zilog *dmu_objset_zil(objset_t *os);
+extern struct dsl_pool *dmu_objset_pool(objset_t *os);
+extern struct dsl_dataset *dmu_objset_ds(objset_t *os);
+extern void dmu_objset_name(objset_t *os, char *buf);
+extern dmu_objset_type_t dmu_objset_type(objset_t *os);
+extern uint64_t dmu_objset_id(objset_t *os);
+extern int dmu_snapshot_list_next(objset_t *os, int namelen, char *name,
+    uint64_t *id, uint64_t *offp, boolean_t *case_conflict);
+extern int dmu_snapshot_realname(objset_t *os, char *name, char *real,
+    int maxlen, boolean_t *conflict);
+extern int dmu_dir_list_next(objset_t *os, int namelen, char *name,
+    uint64_t *idp, uint64_t *offp);
+extern void dmu_objset_set_user(objset_t *os, void *user_ptr);
+extern void *dmu_objset_get_user(objset_t *os);
+
+/*
+ * Return the txg number for the given assigned transaction.
+ */
+uint64_t dmu_tx_get_txg(dmu_tx_t *tx);
+
+/*
+ * Synchronous write.
+ * If a parent zio is provided this function initiates a write on the
+ * provided buffer as a child of the parent zio.
+ * In the absence of a parent zio, the write is completed synchronously.
+ * At write completion, blk is filled with the bp of the written block.
+ * Note that while the data covered by this function will be on stable
+ * storage when the write completes this new data does not become a
+ * permanent part of the file until the associated transaction commits.
+ */
+typedef void dmu_sync_cb_t(dmu_buf_t *db, void *arg);
+int dmu_sync(struct zio *zio, dmu_buf_t *db,
+    struct blkptr *bp, uint64_t txg, dmu_sync_cb_t *done, void *arg);
+
+/*
+ * Find the next hole or data block in file starting at *off
+ * Return found offset in *off. Return ESRCH for end of file.
+ */
+int dmu_offset_next(objset_t *os, uint64_t object, boolean_t hole,
+    uint64_t *off);
+
+/*
+ * Initial setup and final teardown.
+ */
+extern void dmu_init(void);
+extern void dmu_fini(void);
+
+typedef void (*dmu_traverse_cb_t)(objset_t *os, void *arg, struct blkptr *bp,
+    uint64_t object, uint64_t offset, int len);
+void dmu_traverse_objset(objset_t *os, uint64_t txg_start,
+    dmu_traverse_cb_t cb, void *arg);
+
+int dmu_sendbackup(objset_t *tosnap, objset_t *fromsnap, boolean_t fromorigin,
+    struct vnode *vp, offset_t *off);
+
+typedef struct dmu_recv_cookie {
+	/*
+	 * This structure is opaque!
+	 *
+	 * If logical and real are different, we are recving the stream
+	 * into the "real" temporary clone, and then switching it with
+	 * the "logical" target.
+	 */
+	struct dsl_dataset *drc_logical_ds;
+	struct dsl_dataset *drc_real_ds;
+	struct drr_begin *drc_drrb;
+	char *drc_tosnap;
+	boolean_t drc_newfs;
+	boolean_t drc_force;
+} dmu_recv_cookie_t;
+
+int dmu_recv_begin(char *tofs, char *tosnap, struct drr_begin *,
+    boolean_t force, objset_t *origin, boolean_t online, dmu_recv_cookie_t *);
+int dmu_recv_stream(dmu_recv_cookie_t *drc, struct vnode *vp, offset_t *voffp);
+int dmu_recv_end(dmu_recv_cookie_t *drc);
+void dmu_recv_abort_cleanup(dmu_recv_cookie_t *drc);
+
+/* CRC64 table */
+#define	ZFS_CRC64_POLY	0xC96C5795D7870F42ULL	/* ECMA-182, reflected form */
+extern uint64_t zfs_crc64_table[256];
+
+#ifdef	__cplusplus
+}
+#endif
+
+#endif	/* _SYS_DMU_H */