fs/zfs/zfs_acl.c

/*
 * 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 (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
 * Copyright (c) 2013 by Delphix. All rights reserved.
 * Copyright 2020 Tintri by DDN, Inc. All rights reserved.
 * Copyright 2019-2023 RackTop Systems, Inc.
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/time.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <sys/resource.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/sid.h>
#include <sys/file.h>
#include <sys/stat.h>
#include <sys/kmem.h>
#include <sys/cmn_err.h>
#include <sys/errno.h>
#include <sys/unistd.h>
#include <sys/sdt.h>
#include <sys/fs/zfs.h>
#include <sys/mode.h>
#include <sys/policy.h>
#include <sys/zfs_znode.h>
#include <sys/zfs_fuid.h>
#include <sys/zfs_acl.h>
#include <sys/zfs_dir.h>
#include <sys/zfs_vfsops.h>
#include <sys/dmu.h>
#include <sys/dnode.h>
#include <sys/zap.h>
#include <sys/sa.h>
#include "fs/fs_subr.h"
#include <acl/acl_common.h>

#define	ALLOW	ACE_ACCESS_ALLOWED_ACE_TYPE
#define	DENY	ACE_ACCESS_DENIED_ACE_TYPE
#define	MAX_ACE_TYPE	ACE_SYSTEM_ALARM_CALLBACK_OBJECT_ACE_TYPE
#define	MIN_ACE_TYPE	ALLOW

#define	OWNING_GROUP		(ACE_GROUP|ACE_IDENTIFIER_GROUP)
#define	EVERYONE_ALLOW_MASK (ACE_READ_ACL|ACE_READ_ATTRIBUTES | \
    ACE_READ_NAMED_ATTRS|ACE_SYNCHRONIZE)
#define	EVERYONE_DENY_MASK (ACE_WRITE_ACL|ACE_WRITE_OWNER | \
    ACE_WRITE_ATTRIBUTES|ACE_WRITE_NAMED_ATTRS)
#define	OWNER_ALLOW_MASK (ACE_WRITE_ACL | ACE_WRITE_OWNER | \
    ACE_WRITE_ATTRIBUTES|ACE_WRITE_NAMED_ATTRS)

#define	ZFS_CHECKED_MASKS (ACE_READ_ACL|ACE_READ_ATTRIBUTES|ACE_READ_DATA| \
    ACE_READ_NAMED_ATTRS|ACE_WRITE_DATA|ACE_WRITE_ATTRIBUTES| \
    ACE_WRITE_NAMED_ATTRS|ACE_APPEND_DATA|ACE_EXECUTE|ACE_WRITE_OWNER| \
    ACE_WRITE_ACL|ACE_DELETE|ACE_DELETE_CHILD|ACE_SYNCHRONIZE)

#define	WRITE_MASK_DATA (ACE_WRITE_DATA|ACE_APPEND_DATA|ACE_WRITE_NAMED_ATTRS)
#define	WRITE_MASK_ATTRS (ACE_WRITE_ACL|ACE_WRITE_OWNER|ACE_WRITE_ATTRIBUTES| \
    ACE_DELETE|ACE_DELETE_CHILD)
#define	WRITE_MASK (WRITE_MASK_DATA|WRITE_MASK_ATTRS)

#define	OGE_CLEAR	(ACE_READ_DATA|ACE_LIST_DIRECTORY|ACE_WRITE_DATA| \
    ACE_ADD_FILE|ACE_APPEND_DATA|ACE_ADD_SUBDIRECTORY|ACE_EXECUTE)

#define	OKAY_MASK_BITS (ACE_READ_DATA|ACE_LIST_DIRECTORY|ACE_WRITE_DATA| \
    ACE_ADD_FILE|ACE_APPEND_DATA|ACE_ADD_SUBDIRECTORY|ACE_EXECUTE)

#define	ALL_INHERIT	(ACE_FILE_INHERIT_ACE|ACE_DIRECTORY_INHERIT_ACE | \
    ACE_NO_PROPAGATE_INHERIT_ACE|ACE_INHERIT_ONLY_ACE|ACE_INHERITED_ACE)

#define	RESTRICTED_CLEAR	(ACE_WRITE_ACL|ACE_WRITE_OWNER)

#define	V4_ACL_WIDE_FLAGS (ZFS_ACL_AUTO_INHERIT|ZFS_ACL_DEFAULTED|\
    ZFS_ACL_PROTECTED)

#define	ZFS_ACL_WIDE_FLAGS (V4_ACL_WIDE_FLAGS|ZFS_ACL_TRIVIAL|ZFS_INHERIT_ACE|\
    ZFS_ACL_OBJ_ACE)

#define	ALL_MODE_EXECS (S_IXUSR | S_IXGRP | S_IXOTH)

static uint16_t
zfs_ace_v0_get_type(void *acep)
{
	return (((zfs_oldace_t *)acep)->z_type);
}

static uint16_t
zfs_ace_v0_get_flags(void *acep)
{
	return (((zfs_oldace_t *)acep)->z_flags);
}

static uint32_t
zfs_ace_v0_get_mask(void *acep)
{
	return (((zfs_oldace_t *)acep)->z_access_mask);
}

static uint64_t
zfs_ace_v0_get_who(void *acep)
{
	return (((zfs_oldace_t *)acep)->z_fuid);
}

static void
zfs_ace_v0_set_type(void *acep, uint16_t type)
{
	((zfs_oldace_t *)acep)->z_type = type;
}

static void
zfs_ace_v0_set_flags(void *acep, uint16_t flags)
{
	((zfs_oldace_t *)acep)->z_flags = flags;
}

static void
zfs_ace_v0_set_mask(void *acep, uint32_t mask)
{
	((zfs_oldace_t *)acep)->z_access_mask = mask;
}

static void
zfs_ace_v0_set_who(void *acep, uint64_t who)
{
	((zfs_oldace_t *)acep)->z_fuid = who;
}

/*ARGSUSED*/
static size_t
zfs_ace_v0_size(void *acep)
{
	return (sizeof (zfs_oldace_t));
}

static size_t
zfs_ace_v0_abstract_size(void)
{
	return (sizeof (zfs_oldace_t));
}

static int
zfs_ace_v0_mask_off(void)
{
	return (offsetof(zfs_oldace_t, z_access_mask));
}

/*ARGSUSED*/
static int
zfs_ace_v0_data(void *acep, void **datap)
{
	*datap = NULL;
	return (0);
}

static acl_ops_t zfs_acl_v0_ops = {
	zfs_ace_v0_get_mask,
	zfs_ace_v0_set_mask,
	zfs_ace_v0_get_flags,
	zfs_ace_v0_set_flags,
	zfs_ace_v0_get_type,
	zfs_ace_v0_set_type,
	zfs_ace_v0_get_who,
	zfs_ace_v0_set_who,
	zfs_ace_v0_size,
	zfs_ace_v0_abstract_size,
	zfs_ace_v0_mask_off,
	zfs_ace_v0_data
};

static uint16_t
zfs_ace_fuid_get_type(void *acep)
{
	return (((zfs_ace_hdr_t *)acep)->z_type);
}

static uint16_t
zfs_ace_fuid_get_flags(void *acep)
{
	return (((zfs_ace_hdr_t *)acep)->z_flags);
}

static uint32_t
zfs_ace_fuid_get_mask(void *acep)
{
	return (((zfs_ace_hdr_t *)acep)->z_access_mask);
}

static uint64_t
zfs_ace_fuid_get_who(void *args)
{
	uint16_t entry_type;
	zfs_ace_t *acep = args;

	entry_type = acep->z_hdr.z_flags & ACE_TYPE_FLAGS;

	if (entry_type == ACE_OWNER || entry_type == OWNING_GROUP ||
	    entry_type == ACE_EVERYONE)
		return (-1);
	return (((zfs_ace_t *)acep)->z_fuid);
}

static void
zfs_ace_fuid_set_type(void *acep, uint16_t type)
{
	((zfs_ace_hdr_t *)acep)->z_type = type;
}

static void
zfs_ace_fuid_set_flags(void *acep, uint16_t flags)
{
	((zfs_ace_hdr_t *)acep)->z_flags = flags;
}

static void
zfs_ace_fuid_set_mask(void *acep, uint32_t mask)
{
	((zfs_ace_hdr_t *)acep)->z_access_mask = mask;
}

static void
zfs_ace_fuid_set_who(void *arg, uint64_t who)
{
	zfs_ace_t *acep = arg;

	uint16_t entry_type = acep->z_hdr.z_flags & ACE_TYPE_FLAGS;

	if (entry_type == ACE_OWNER || entry_type == OWNING_GROUP ||
	    entry_type == ACE_EVERYONE)
		return;
	acep->z_fuid = who;
}

static size_t
zfs_ace_fuid_size(void *acep)
{
	zfs_ace_hdr_t *zacep = acep;
	uint16_t entry_type;

	switch (zacep->z_type) {
	case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
	case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
	case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
	case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
		return (sizeof (zfs_object_ace_t));
	case ALLOW:
	case DENY:
		entry_type =
		    (((zfs_ace_hdr_t *)acep)->z_flags & ACE_TYPE_FLAGS);
		if (entry_type == ACE_OWNER ||
		    entry_type == OWNING_GROUP ||
		    entry_type == ACE_EVERYONE)
			return (sizeof (zfs_ace_hdr_t));
		/*FALLTHROUGH*/
	default:
		return (sizeof (zfs_ace_t));
	}
}

static size_t
zfs_ace_fuid_abstract_size(void)
{
	return (sizeof (zfs_ace_hdr_t));
}

static int
zfs_ace_fuid_mask_off(void)
{
	return (offsetof(zfs_ace_hdr_t, z_access_mask));
}

static int
zfs_ace_fuid_data(void *acep, void **datap)
{
	zfs_ace_t *zacep = acep;
	zfs_object_ace_t *zobjp;

	switch (zacep->z_hdr.z_type) {
	case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
	case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
	case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
	case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
		zobjp = acep;
		*datap = (caddr_t)zobjp + sizeof (zfs_ace_t);
		return (sizeof (zfs_object_ace_t) - sizeof (zfs_ace_t));
	default:
		*datap = NULL;
		return (0);
	}
}

static acl_ops_t zfs_acl_fuid_ops = {
	zfs_ace_fuid_get_mask,
	zfs_ace_fuid_set_mask,
	zfs_ace_fuid_get_flags,
	zfs_ace_fuid_set_flags,
	zfs_ace_fuid_get_type,
	zfs_ace_fuid_set_type,
	zfs_ace_fuid_get_who,
	zfs_ace_fuid_set_who,
	zfs_ace_fuid_size,
	zfs_ace_fuid_abstract_size,
	zfs_ace_fuid_mask_off,
	zfs_ace_fuid_data
};

/*
 * The following three functions are provided for compatibility with
 * older ZPL version in order to determine if the file use to have
 * an external ACL and what version of ACL previously existed on the
 * file.  Would really be nice to not need this, sigh.
 */
uint64_t
zfs_external_acl(znode_t *zp)
{
	zfs_acl_phys_t acl_phys;
	int error;

	if (zp->z_is_sa)
		return (0);

	/*
	 * Need to deal with a potential
	 * race where zfs_sa_upgrade could cause
	 * z_isa_sa to change.
	 *
	 * If the lookup fails then the state of z_is_sa should have
	 * changed.
	 */

	if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_ZNODE_ACL(zp->z_zfsvfs),
	    &acl_phys, sizeof (acl_phys))) == 0)
		return (acl_phys.z_acl_extern_obj);
	else {
		/*
		 * after upgrade the SA_ZPL_ZNODE_ACL should have been
		 * removed
		 */
		VERIFY(zp->z_is_sa && error == ENOENT);
		return (0);
	}
}

/*
 * Determine size of ACL in bytes
 *
 * This is more complicated than it should be since we have to deal
 * with old external ACLs.
 */
static int
zfs_acl_znode_info(znode_t *zp, int *aclsize, int *aclcount,
    zfs_acl_phys_t *aclphys)
{
	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
	uint64_t acl_count;
	int size;
	int error;

	ASSERT(MUTEX_HELD(&zp->z_acl_lock));
	if (zp->z_is_sa) {
		if ((error = sa_size(zp->z_sa_hdl, SA_ZPL_DACL_ACES(zfsvfs),
		    &size)) != 0)
			return (error);
		*aclsize = size;
		if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_DACL_COUNT(zfsvfs),
		    &acl_count, sizeof (acl_count))) != 0)
			return (error);
		*aclcount = acl_count;
	} else {
		if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_ZNODE_ACL(zfsvfs),
		    aclphys, sizeof (*aclphys))) != 0)
			return (error);

		if (aclphys->z_acl_version == ZFS_ACL_VERSION_INITIAL) {
			*aclsize = ZFS_ACL_SIZE(aclphys->z_acl_size);
			*aclcount = aclphys->z_acl_size;
		} else {
			*aclsize = aclphys->z_acl_size;
			*aclcount = aclphys->z_acl_count;
		}
	}
	return (0);
}

int
zfs_znode_acl_version(znode_t *zp)
{
	zfs_acl_phys_t acl_phys;

	if (zp->z_is_sa)
		return (ZFS_ACL_VERSION_FUID);
	else {
		int error;

		/*
		 * Need to deal with a potential
		 * race where zfs_sa_upgrade could cause
		 * z_isa_sa to change.
		 *
		 * If the lookup fails then the state of z_is_sa should have
		 * changed.
		 */
		if ((error = sa_lookup(zp->z_sa_hdl,
		    SA_ZPL_ZNODE_ACL(zp->z_zfsvfs),
		    &acl_phys, sizeof (acl_phys))) == 0)
			return (acl_phys.z_acl_version);
		else {
			/*
			 * After upgrade SA_ZPL_ZNODE_ACL should have
			 * been removed.
			 */
			VERIFY(zp->z_is_sa && error == ENOENT);
			return (ZFS_ACL_VERSION_FUID);
		}
	}
}

static int
zfs_acl_version(int version)
{
	if (version < ZPL_VERSION_FUID)
		return (ZFS_ACL_VERSION_INITIAL);
	else
		return (ZFS_ACL_VERSION_FUID);
}

static int
zfs_acl_version_zp(znode_t *zp)
{
	return (zfs_acl_version(zp->z_zfsvfs->z_version));
}

zfs_acl_t *
zfs_acl_alloc(int vers)
{
	zfs_acl_t *aclp;

	aclp = kmem_zalloc(sizeof (zfs_acl_t), KM_SLEEP);
	list_create(&aclp->z_acl, sizeof (zfs_acl_node_t),
	    offsetof(zfs_acl_node_t, z_next));
	aclp->z_version = vers;
	if (vers == ZFS_ACL_VERSION_FUID)
		aclp->z_ops = zfs_acl_fuid_ops;
	else
		aclp->z_ops = zfs_acl_v0_ops;
	return (aclp);
}

zfs_acl_node_t *
zfs_acl_node_alloc(size_t bytes)
{
	zfs_acl_node_t *aclnode;

	aclnode = kmem_zalloc(sizeof (zfs_acl_node_t), KM_SLEEP);
	if (bytes) {
		aclnode->z_acldata = kmem_alloc(bytes, KM_SLEEP);
		aclnode->z_allocdata = aclnode->z_acldata;
		aclnode->z_allocsize = bytes;
		aclnode->z_size = bytes;
	}

	return (aclnode);
}

static void
zfs_acl_node_free(zfs_acl_node_t *aclnode)
{
	if (aclnode->z_allocsize)
		kmem_free(aclnode->z_allocdata, aclnode->z_allocsize);
	kmem_free(aclnode, sizeof (zfs_acl_node_t));
}

static void
zfs_acl_release_nodes(zfs_acl_t *aclp)
{
	zfs_acl_node_t *aclnode;

	while (aclnode = list_head(&aclp->z_acl)) {
		list_remove(&aclp->z_acl, aclnode);
		zfs_acl_node_free(aclnode);
	}
	aclp->z_acl_count = 0;
	aclp->z_acl_bytes = 0;
}

void
zfs_acl_free(zfs_acl_t *aclp)
{
	zfs_acl_release_nodes(aclp);
	list_destroy(&aclp->z_acl);
	kmem_free(aclp, sizeof (zfs_acl_t));
}

static boolean_t
zfs_acl_valid_ace_type(uint_t type, uint_t flags)
{
	uint16_t entry_type;

	switch (type) {
	case ALLOW:
	case DENY:
	case ACE_SYSTEM_AUDIT_ACE_TYPE:
	case ACE_SYSTEM_ALARM_ACE_TYPE:
		entry_type = flags & ACE_TYPE_FLAGS;
		return (entry_type == ACE_OWNER ||
		    entry_type == OWNING_GROUP ||
		    entry_type == ACE_EVERYONE || entry_type == 0 ||
		    entry_type == ACE_IDENTIFIER_GROUP);
	default:
		if (type >= MIN_ACE_TYPE && type <= MAX_ACE_TYPE)
			return (B_TRUE);
	}
	return (B_FALSE);
}

static boolean_t
zfs_ace_valid(vtype_t obj_type, zfs_acl_t *aclp, uint16_t type, uint16_t iflags)
{
	/*
	 * first check type of entry
	 */

	if (!zfs_acl_valid_ace_type(type, iflags))
		return (B_FALSE);

	switch (type) {
	case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
	case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
	case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
	case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
		if (aclp->z_version < ZFS_ACL_VERSION_FUID)
			return (B_FALSE);
		aclp->z_hints |= ZFS_ACL_OBJ_ACE;
	}

	/*
	 * next check inheritance level flags
	 */

	if (obj_type == VDIR &&
	    (iflags & (ACE_FILE_INHERIT_ACE|ACE_DIRECTORY_INHERIT_ACE)))
		aclp->z_hints |= ZFS_INHERIT_ACE;

	if (iflags & (ACE_INHERIT_ONLY_ACE|ACE_NO_PROPAGATE_INHERIT_ACE)) {
		if ((iflags & (ACE_FILE_INHERIT_ACE|
		    ACE_DIRECTORY_INHERIT_ACE)) == 0) {
			return (B_FALSE);
		}
	}

	return (B_TRUE);
}

static void *
zfs_acl_next_ace(zfs_acl_t *aclp, void *start, uint64_t *who,
    uint32_t *access_mask, uint16_t *iflags, uint16_t *type)
{
	zfs_acl_node_t *aclnode;

	ASSERT(aclp);

	if (start == NULL) {
		aclnode = list_head(&aclp->z_acl);
		if (aclnode == NULL)
			return (NULL);

		aclp->z_next_ace = aclnode->z_acldata;
		aclp->z_curr_node = aclnode;
		aclnode->z_ace_idx = 0;
	}

	aclnode = aclp->z_curr_node;

	if (aclnode == NULL)
		return (NULL);

	if (aclnode->z_ace_idx >= aclnode->z_ace_count) {
		aclnode = list_next(&aclp->z_acl, aclnode);
		if (aclnode == NULL)
			return (NULL);
		else {
			aclp->z_curr_node = aclnode;
			aclnode->z_ace_idx = 0;
			aclp->z_next_ace = aclnode->z_acldata;
		}
	}

	if (aclnode->z_ace_idx < aclnode->z_ace_count) {
		void *acep = aclp->z_next_ace;
		size_t ace_size;

		/*
		 * Make sure we don't overstep our bounds
		 */
		ace_size = aclp->z_ops.ace_size(acep);

		if (((caddr_t)acep + ace_size) >
		    ((caddr_t)aclnode->z_acldata + aclnode->z_size)) {
			return (NULL);
		}

		*iflags = aclp->z_ops.ace_flags_get(acep);
		*type = aclp->z_ops.ace_type_get(acep);
		*access_mask = aclp->z_ops.ace_mask_get(acep);
		*who = aclp->z_ops.ace_who_get(acep);
		aclp->z_next_ace = (caddr_t)aclp->z_next_ace + ace_size;
		aclnode->z_ace_idx++;

		return ((void *)acep);
	}
	return (NULL);
}

/*ARGSUSED*/
static uint64_t
zfs_ace_walk(void *datap, uint64_t cookie, int aclcnt,
    uint16_t *flags, uint16_t *type, uint32_t *mask)
{
	zfs_acl_t *aclp = datap;
	zfs_ace_hdr_t *acep = (zfs_ace_hdr_t *)(uintptr_t)cookie;
	uint64_t who;

	acep = zfs_acl_next_ace(aclp, acep, &who, mask,
	    flags, type);
	return ((uint64_t)(uintptr_t)acep);
}

static zfs_acl_node_t *
zfs_acl_curr_node(zfs_acl_t *aclp)
{
	ASSERT(aclp->z_curr_node);
	return (aclp->z_curr_node);
}

/*
 * Copy ACE to internal ZFS format.
 * While processing the ACL each ACE will be validated for correctness.
 * ACE FUIDs will be created later.
 */
int
zfs_copy_ace_2_fuid(zfsvfs_t *zfsvfs, vtype_t obj_type, zfs_acl_t *aclp,
    void *datap, zfs_ace_t *z_acl, uint64_t aclcnt, size_t *size,
    zfs_fuid_info_t **fuidp, cred_t *cr)
{
	int i;
	uint16_t entry_type;
	zfs_ace_t *aceptr = z_acl;
	ace_t *acep = datap;
	zfs_object_ace_t *zobjacep;
	ace_object_t *aceobjp;

	for (i = 0; i != aclcnt; i++) {
		aceptr->z_hdr.z_access_mask = acep->a_access_mask;
		aceptr->z_hdr.z_flags = acep->a_flags;
		aceptr->z_hdr.z_type = acep->a_type;
		entry_type = aceptr->z_hdr.z_flags & ACE_TYPE_FLAGS;
		if (entry_type != ACE_OWNER && entry_type != OWNING_GROUP &&
		    entry_type != ACE_EVERYONE) {
			aceptr->z_fuid = zfs_fuid_create(zfsvfs, acep->a_who,
			    cr, (entry_type == 0) ?
			    ZFS_ACE_USER : ZFS_ACE_GROUP, fuidp);
		}

		/*
		 * Make sure ACE is valid
		 */
		if (zfs_ace_valid(obj_type, aclp, aceptr->z_hdr.z_type,
		    aceptr->z_hdr.z_flags) != B_TRUE)
			return (SET_ERROR(EINVAL));

		switch (acep->a_type) {
		case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
		case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
		case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
		case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
			zobjacep = (zfs_object_ace_t *)aceptr;
			aceobjp = (ace_object_t *)acep;

			bcopy(aceobjp->a_obj_type, zobjacep->z_object_type,
			    sizeof (aceobjp->a_obj_type));
			bcopy(aceobjp->a_inherit_obj_type,
			    zobjacep->z_inherit_type,
			    sizeof (aceobjp->a_inherit_obj_type));
			acep = (ace_t *)((caddr_t)acep + sizeof (ace_object_t));
			break;
		default:
			acep = (ace_t *)((caddr_t)acep + sizeof (ace_t));
		}

		aceptr = (zfs_ace_t *)((caddr_t)aceptr +
		    aclp->z_ops.ace_size(aceptr));
	}

	*size = (caddr_t)aceptr - (caddr_t)z_acl;

	return (0);
}

/*
 * Copy ZFS ACEs to fixed size ace_t layout
 */
static void
zfs_copy_fuid_2_ace(zfsvfs_t *zfsvfs, zfs_acl_t *aclp, cred_t *cr,
    void *datap, int filter)
{
	uint64_t who;
	uint32_t access_mask;
	uint16_t iflags, type;
	zfs_ace_hdr_t *zacep = NULL;
	ace_t *acep = datap;
	ace_object_t *objacep;
	zfs_object_ace_t *zobjacep;
	size_t ace_size;
	uint16_t entry_type;

	while (zacep = zfs_acl_next_ace(aclp, zacep,
	    &who, &access_mask, &iflags, &type)) {

		switch (type) {
		case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
		case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
		case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
		case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
			if (filter) {
				continue;
			}
			zobjacep = (zfs_object_ace_t *)zacep;
			objacep = (ace_object_t *)acep;
			bcopy(zobjacep->z_object_type,
			    objacep->a_obj_type,
			    sizeof (zobjacep->z_object_type));
			bcopy(zobjacep->z_inherit_type,
			    objacep->a_inherit_obj_type,
			    sizeof (zobjacep->z_inherit_type));
			ace_size = sizeof (ace_object_t);
			break;
		default:
			ace_size = sizeof (ace_t);
			break;
		}

		entry_type = (iflags & ACE_TYPE_FLAGS);
		if ((entry_type != ACE_OWNER &&
		    entry_type != OWNING_GROUP &&
		    entry_type != ACE_EVERYONE)) {
			acep->a_who = zfs_fuid_map_id(zfsvfs, who,
			    cr, (entry_type & ACE_IDENTIFIER_GROUP) ?
			    ZFS_ACE_GROUP : ZFS_ACE_USER);
		} else {
			acep->a_who = (uid_t)(int64_t)who;
		}
		acep->a_access_mask = access_mask;
		acep->a_flags = iflags;
		acep->a_type = type;
		acep = (ace_t *)((caddr_t)acep + ace_size);
	}
}

static int
zfs_copy_ace_2_oldace(vtype_t obj_type, zfs_acl_t *aclp, ace_t *acep,
    zfs_oldace_t *z_acl, int aclcnt, size_t *size)
{
	int i;
	zfs_oldace_t *aceptr = z_acl;

	for (i = 0; i != aclcnt; i++, aceptr++) {
		aceptr->z_access_mask = acep[i].a_access_mask;
		aceptr->z_type = acep[i].a_type;
		aceptr->z_flags = acep[i].a_flags;
		aceptr->z_fuid = acep[i].a_who;
		/*
		 * Make sure ACE is valid
		 */
		if (zfs_ace_valid(obj_type, aclp, aceptr->z_type,
		    aceptr->z_flags) != B_TRUE)
			return (SET_ERROR(EINVAL));
	}
	*size = (caddr_t)aceptr - (caddr_t)z_acl;
	return (0);
}

/*
 * convert old ACL format to new
 */
void
zfs_acl_xform(znode_t *zp, zfs_acl_t *aclp, cred_t *cr)
{
	zfs_oldace_t *oldaclp;
	int i;
	uint16_t type, iflags;
	uint32_t access_mask;
	uint64_t who;
	void *cookie = NULL;
	zfs_acl_node_t *newaclnode;

	ASSERT(aclp->z_version == ZFS_ACL_VERSION_INITIAL);
	/*
	 * First create the ACE in a contiguous piece of memory
	 * for zfs_copy_ace_2_fuid().
	 *
	 * We only convert an ACL once, so this won't happen
	 * everytime.
	 */
	oldaclp = kmem_alloc(sizeof (zfs_oldace_t) * aclp->z_acl_count,
	    KM_SLEEP);
	i = 0;
	while (cookie = zfs_acl_next_ace(aclp, cookie, &who,
	    &access_mask, &iflags, &type)) {
		oldaclp[i].z_flags = iflags;
		oldaclp[i].z_type = type;
		oldaclp[i].z_fuid = who;
		oldaclp[i++].z_access_mask = access_mask;
	}

	newaclnode = zfs_acl_node_alloc(aclp->z_acl_count *
	    sizeof (zfs_object_ace_t));
	aclp->z_ops = zfs_acl_fuid_ops;
	VERIFY(zfs_copy_ace_2_fuid(zp->z_zfsvfs, ZTOV(zp)->v_type, aclp,
	    oldaclp, newaclnode->z_acldata, aclp->z_acl_count,
	    &newaclnode->z_size, NULL, cr) == 0);
	newaclnode->z_ace_count = aclp->z_acl_count;
	aclp->z_version = ZFS_ACL_VERSION;
	kmem_free(oldaclp, aclp->z_acl_count * sizeof (zfs_oldace_t));

	/*
	 * Release all previous ACL nodes
	 */

	zfs_acl_release_nodes(aclp);

	list_insert_head(&aclp->z_acl, newaclnode);

	aclp->z_acl_bytes = newaclnode->z_size;
	aclp->z_acl_count = newaclnode->z_ace_count;

}

/*
 * Convert unix access mask to v4 access mask
 */
static uint32_t
zfs_unix_to_v4(uint32_t access_mask)
{
	uint32_t new_mask = 0;

	if (access_mask & S_IXOTH)
		new_mask |= ACE_EXECUTE;
	if (access_mask & S_IWOTH)
		new_mask |= ACE_WRITE_DATA;
	if (access_mask & S_IROTH)
		new_mask |= ACE_READ_DATA;
	return (new_mask);
}

static void
zfs_set_ace(zfs_acl_t *aclp, void *acep, uint32_t access_mask,
    uint16_t access_type, uint64_t fuid, uint16_t entry_type)
{
	uint16_t type = entry_type & ACE_TYPE_FLAGS;

	aclp->z_ops.ace_mask_set(acep, access_mask);
	aclp->z_ops.ace_type_set(acep, access_type);
	aclp->z_ops.ace_flags_set(acep, entry_type);
	if ((type != ACE_OWNER && type != OWNING_GROUP &&
	    type != ACE_EVERYONE))
		aclp->z_ops.ace_who_set(acep, fuid);
}

/*
 * Determine mode of file based on ACL.
 */
uint64_t
zfs_mode_compute(uint64_t fmode, zfs_acl_t *aclp,
    uint64_t *pflags, uint64_t fuid, uint64_t fgid)
{
	int		entry_type;
	mode_t		mode;
	mode_t		seen = 0;
	zfs_ace_hdr_t	*acep = NULL;
	uint64_t	who;
	uint16_t	iflags, type;
	uint32_t	access_mask;
	boolean_t	an_exec_denied = B_FALSE;

	mode = (fmode & (S_IFMT | S_ISUID | S_ISGID | S_ISVTX));

	while (acep = zfs_acl_next_ace(aclp, acep, &who,
	    &access_mask, &iflags, &type)) {

		if (!zfs_acl_valid_ace_type(type, iflags))
			continue;

		entry_type = (iflags & ACE_TYPE_FLAGS);

		/*
		 * Skip over any inherit_only ACEs
		 */
		if (iflags & ACE_INHERIT_ONLY_ACE)
			continue;

		if (entry_type == ACE_OWNER || (entry_type == 0 &&
		    who == fuid)) {
			if ((access_mask & ACE_READ_DATA) &&
			    (!(seen & S_IRUSR))) {
				seen |= S_IRUSR;
				if (type == ALLOW) {
					mode |= S_IRUSR;
				}
			}
			if ((access_mask & ACE_WRITE_DATA) &&
			    (!(seen & S_IWUSR))) {
				seen |= S_IWUSR;
				if (type == ALLOW) {
					mode |= S_IWUSR;
				}
			}
			if ((access_mask & ACE_EXECUTE) &&
			    (!(seen & S_IXUSR))) {
				seen |= S_IXUSR;
				if (type == ALLOW) {
					mode |= S_IXUSR;
				}
			}
		} else if (entry_type == OWNING_GROUP ||
		    (entry_type == ACE_IDENTIFIER_GROUP && who == fgid)) {
			if ((access_mask & ACE_READ_DATA) &&
			    (!(seen & S_IRGRP))) {
				seen |= S_IRGRP;
				if (type == ALLOW) {
					mode |= S_IRGRP;
				}
			}
			if ((access_mask & ACE_WRITE_DATA) &&
			    (!(seen & S_IWGRP))) {
				seen |= S_IWGRP;
				if (type == ALLOW) {
					mode |= S_IWGRP;
				}
			}
			if ((access_mask & ACE_EXECUTE) &&
			    (!(seen & S_IXGRP))) {
				seen |= S_IXGRP;
				if (type == ALLOW) {
					mode |= S_IXGRP;
				}
			}
		} else if (entry_type == ACE_EVERYONE) {
			if ((access_mask & ACE_READ_DATA)) {
				if (!(seen & S_IRUSR)) {
					seen |= S_IRUSR;
					if (type == ALLOW) {
						mode |= S_IRUSR;
					}
				}
				if (!(seen & S_IRGRP)) {
					seen |= S_IRGRP;
					if (type == ALLOW) {
						mode |= S_IRGRP;
					}
				}
				if (!(seen & S_IROTH)) {
					seen |= S_IROTH;
					if (type == ALLOW) {
						mode |= S_IROTH;
					}
				}
			}
			if ((access_mask & ACE_WRITE_DATA)) {
				if (!(seen & S_IWUSR)) {
					seen |= S_IWUSR;
					if (type == ALLOW) {
						mode |= S_IWUSR;
					}
				}
				if (!(seen & S_IWGRP)) {
					seen |= S_IWGRP;
					if (type == ALLOW) {
						mode |= S_IWGRP;
					}
				}
				if (!(seen & S_IWOTH)) {
					seen |= S_IWOTH;
					if (type == ALLOW) {
						mode |= S_IWOTH;
					}
				}
			}
			if ((access_mask & ACE_EXECUTE)) {
				if (!(seen & S_IXUSR)) {
					seen |= S_IXUSR;
					if (type == ALLOW) {
						mode |= S_IXUSR;
					}
				}
				if (!(seen & S_IXGRP)) {
					seen |= S_IXGRP;
					if (type == ALLOW) {
						mode |= S_IXGRP;
					}
				}
				if (!(seen & S_IXOTH)) {
					seen |= S_IXOTH;
					if (type == ALLOW) {
						mode |= S_IXOTH;
					}
				}
			}
		} else {
			/*
			 * Only care if this IDENTIFIER_GROUP or
			 * USER ACE denies execute access to someone,
			 * mode is not affected
			 */
			if ((access_mask & ACE_EXECUTE) && type == DENY)
				an_exec_denied = B_TRUE;
		}
	}

	/*
	 * Failure to allow is effectively a deny, so execute permission
	 * is denied if it was never mentioned or if we explicitly
	 * weren't allowed it.
	 */
	if (!an_exec_denied &&
	    ((seen & ALL_MODE_EXECS) != ALL_MODE_EXECS ||
	    (mode & ALL_MODE_EXECS) != ALL_MODE_EXECS))
		an_exec_denied = B_TRUE;

	if (an_exec_denied)
		*pflags &= ~ZFS_NO_EXECS_DENIED;
	else
		*pflags |= ZFS_NO_EXECS_DENIED;

	return (mode);
}

/*
 * Read an external acl object.  If the intent is to modify, always
 * create a new acl and leave any cached acl in place.
 */
int
zfs_acl_node_read(struct znode *zp, boolean_t have_lock, zfs_acl_t **aclpp,
    boolean_t will_modify)
{
	zfs_acl_t	*aclp;
	int		aclsize;
	int		acl_count;
	zfs_acl_node_t	*aclnode;
	zfs_acl_phys_t	znode_acl;
	int		version;
	int		error;
	boolean_t	drop_lock = B_FALSE;

	ASSERT(MUTEX_HELD(&zp->z_acl_lock));

	if (zp->z_acl_cached && !will_modify) {
		*aclpp = zp->z_acl_cached;
		return (0);
	}

	/*
	 * close race where znode could be upgrade while trying to
	 * read the znode attributes.
	 *
	 * But this could only happen if the file isn't already an SA
	 * znode
	 */
	if (!zp->z_is_sa && !have_lock) {
		mutex_enter(&zp->z_lock);
		drop_lock = B_TRUE;
	}
	version = zfs_znode_acl_version(zp);

	if ((error = zfs_acl_znode_info(zp, &aclsize,
	    &acl_count, &znode_acl)) != 0) {
		goto done;
	}

	aclp = zfs_acl_alloc(version);

	aclp->z_acl_count = acl_count;
	aclp->z_acl_bytes = aclsize;

	aclnode = zfs_acl_node_alloc(aclsize);
	aclnode->z_ace_count = aclp->z_acl_count;
	aclnode->z_size = aclsize;

	if (!zp->z_is_sa) {
		if (znode_acl.z_acl_extern_obj) {
			error = dmu_read(zp->z_zfsvfs->z_os,
			    znode_acl.z_acl_extern_obj, 0, aclnode->z_size,
			    aclnode->z_acldata, DMU_READ_PREFETCH);
		} else {
			bcopy(znode_acl.z_ace_data, aclnode->z_acldata,
			    aclnode->z_size);
		}
	} else {
		error = sa_lookup(zp->z_sa_hdl, SA_ZPL_DACL_ACES(zp->z_zfsvfs),
		    aclnode->z_acldata, aclnode->z_size);
	}

	if (error != 0) {
		zfs_acl_free(aclp);
		zfs_acl_node_free(aclnode);
		/* convert checksum errors into IO errors */
		if (error == ECKSUM)
			error = SET_ERROR(EIO);
		goto done;
	}

	list_insert_head(&aclp->z_acl, aclnode);

	*aclpp = aclp;
	if (!will_modify)
		zp->z_acl_cached = aclp;
done:
	if (drop_lock)
		mutex_exit(&zp->z_lock);
	return (error);
}

/*ARGSUSED*/
void
zfs_acl_data_locator(void **dataptr, uint32_t *length, uint32_t buflen,
    boolean_t start, void *userdata)
{
	zfs_acl_locator_cb_t *cb = (zfs_acl_locator_cb_t *)userdata;

	if (start) {
		cb->cb_acl_node = list_head(&cb->cb_aclp->z_acl);
	} else {
		cb->cb_acl_node = list_next(&cb->cb_aclp->z_acl,
		    cb->cb_acl_node);
	}
	*dataptr = cb->cb_acl_node->z_acldata;
	*length = cb->cb_acl_node->z_size;
}

int
zfs_acl_chown_setattr(znode_t *zp)
{
	int error;
	zfs_acl_t *aclp;

	ASSERT(MUTEX_HELD(&zp->z_lock));
	ASSERT(MUTEX_HELD(&zp->z_acl_lock));

	if ((error = zfs_acl_node_read(zp, B_TRUE, &aclp, B_FALSE)) == 0)
		zp->z_mode = zfs_mode_compute(zp->z_mode, aclp,
		    &zp->z_pflags, zp->z_uid, zp->z_gid);
	return (error);
}

/*
 * common code for setting ACLs.
 *
 * This function is called from zfs_mode_update, zfs_perm_init, and zfs_setacl.
 * zfs_setacl passes a non-NULL inherit pointer (ihp) to indicate that it's
 * already checked the acl and knows whether to inherit.
 */
int
zfs_aclset_common(znode_t *zp, zfs_acl_t *aclp, cred_t *cr, dmu_tx_t *tx)
{
	int			error;
	zfsvfs_t		*zfsvfs = zp->z_zfsvfs;
	dmu_object_type_t	otype;
	zfs_acl_locator_cb_t	locate = { 0 };
	uint64_t		mode;
	sa_bulk_attr_t		bulk[5];
	uint64_t		ctime[2];
	int			count = 0;
	zfs_acl_phys_t		acl_phys;

	mode = zp->z_mode;

	mode = zfs_mode_compute(mode, aclp, &zp->z_pflags,
	    zp->z_uid, zp->z_gid);

	zp->z_mode = mode;
	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MODE(zfsvfs), NULL,
	    &mode, sizeof (mode));
	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
	    &zp->z_pflags, sizeof (zp->z_pflags));
	SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL,
	    &ctime, sizeof (ctime));

	if (zp->z_acl_cached) {
		zfs_acl_free(zp->z_acl_cached);
		zp->z_acl_cached = NULL;
	}

	/*
	 * Upgrade needed?
	 */
	if (!zfsvfs->z_use_fuids) {
		otype = DMU_OT_OLDACL;
	} else {
		if ((aclp->z_version == ZFS_ACL_VERSION_INITIAL) &&
		    (zfsvfs->z_version >= ZPL_VERSION_FUID))
			zfs_acl_xform(zp, aclp, cr);
		ASSERT(aclp->z_version >= ZFS_ACL_VERSION_FUID);
		otype = DMU_OT_ACL;
	}

	/*
	 * Arrgh, we have to handle old on disk format
	 * as well as newer (preferred) SA format.
	 */

	if (zp->z_is_sa) { /* the easy case, just update the ACL attribute */
		locate.cb_aclp = aclp;
		SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_DACL_ACES(zfsvfs),
		    zfs_acl_data_locator, &locate, aclp->z_acl_bytes);
		SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_DACL_COUNT(zfsvfs),
		    NULL, &aclp->z_acl_count, sizeof (uint64_t));
	} else { /* Painful legacy way */
		zfs_acl_node_t *aclnode;
		uint64_t off = 0;
		uint64_t aoid;

		if ((error = sa_lookup(zp->z_sa_hdl, SA_ZPL_ZNODE_ACL(zfsvfs),
		    &acl_phys, sizeof (acl_phys))) != 0)
			return (error);

		aoid = acl_phys.z_acl_extern_obj;

		if (aclp->z_acl_bytes > ZFS_ACE_SPACE) {
			/*
			 * If ACL was previously external and we are now
			 * converting to new ACL format then release old
			 * ACL object and create a new one.
			 */
			if (aoid &&
			    aclp->z_version != acl_phys.z_acl_version) {
				error = dmu_object_free(zfsvfs->z_os, aoid, tx);
				if (error)
					return (error);
				aoid = 0;
			}
			if (aoid == 0) {
				aoid = dmu_object_alloc(zfsvfs->z_os,
				    otype, aclp->z_acl_bytes,
				    otype == DMU_OT_ACL ?
				    DMU_OT_SYSACL : DMU_OT_NONE,
				    otype == DMU_OT_ACL ?
				    DN_OLD_MAX_BONUSLEN : 0, tx);
			} else {
				(void) dmu_object_set_blocksize(zfsvfs->z_os,
				    aoid, aclp->z_acl_bytes, 0, tx);
			}
			acl_phys.z_acl_extern_obj = aoid;
			for (aclnode = list_head(&aclp->z_acl); aclnode;
			    aclnode = list_next(&aclp->z_acl, aclnode)) {
				if (aclnode->z_ace_count == 0)
					continue;
				dmu_write(zfsvfs->z_os, aoid, off,
				    aclnode->z_size, aclnode->z_acldata, tx);
				off += aclnode->z_size;
			}
		} else {
			void *start = acl_phys.z_ace_data;
			/*
			 * Migrating back embedded?
			 */
			if (acl_phys.z_acl_extern_obj) {
				error = dmu_object_free(zfsvfs->z_os,
				    acl_phys.z_acl_extern_obj, tx);
				if (error)
					return (error);
				acl_phys.z_acl_extern_obj = 0;
			}

			for (aclnode = list_head(&aclp->z_acl); aclnode;
			    aclnode = list_next(&aclp->z_acl, aclnode)) {
				if (aclnode->z_ace_count == 0)
					continue;
				bcopy(aclnode->z_acldata, start,
				    aclnode->z_size);
				start = (caddr_t)start + aclnode->z_size;
			}
		}
		/*
		 * If Old version then swap count/bytes to match old
		 * layout of znode_acl_phys_t.
		 */
		if (aclp->z_version == ZFS_ACL_VERSION_INITIAL) {
			acl_phys.z_acl_size = aclp->z_acl_count;
			acl_phys.z_acl_count = aclp->z_acl_bytes;
		} else {
			acl_phys.z_acl_size = aclp->z_acl_bytes;
			acl_phys.z_acl_count = aclp->z_acl_count;
		}
		acl_phys.z_acl_version = aclp->z_version;

		SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_ZNODE_ACL(zfsvfs), NULL,
		    &acl_phys, sizeof (acl_phys));
	}

	/*
	 * Replace ACL wide bits, but first clear them.
	 */
	zp->z_pflags &= ~ZFS_ACL_WIDE_FLAGS;

	zp->z_pflags |= aclp->z_hints;

	if (ace_trivial_common(aclp, 0, zfs_ace_walk) == 0)
		zp->z_pflags |= ZFS_ACL_TRIVIAL;

	zfs_tstamp_update_setup(zp, STATE_CHANGED, NULL, ctime, B_TRUE);
	return (sa_bulk_update(zp->z_sa_hdl, bulk, count, tx));
}

static void
zfs_acl_chmod(vtype_t vtype, uint64_t mode, boolean_t split, boolean_t trim,
    zfs_acl_t *aclp)
{
	void		*acep = NULL;
	uint64_t	who;
	int		new_count, new_bytes;
	int		ace_size;
	int		entry_type;
	uint16_t	iflags, type;
	uint32_t	access_mask;
	zfs_acl_node_t	*newnode;
	size_t		abstract_size = aclp->z_ops.ace_abstract_size();
	void		*zacep;
	boolean_t	isdir;
	trivial_acl_t	masks;

	new_count = new_bytes = 0;

	isdir = (vtype == VDIR);

	acl_trivial_access_masks((mode_t)mode, isdir, &masks);

	newnode = zfs_acl_node_alloc((abstract_size * 6) + aclp->z_acl_bytes);

	zacep = newnode->z_acldata;
	if (masks.allow0) {
		zfs_set_ace(aclp, zacep, masks.allow0, ALLOW, -1, ACE_OWNER);
		zacep = (void *)((uintptr_t)zacep + abstract_size);
		new_count++;
		new_bytes += abstract_size;
	}
	if (masks.deny1) {
		zfs_set_ace(aclp, zacep, masks.deny1, DENY, -1, ACE_OWNER);
		zacep = (void *)((uintptr_t)zacep + abstract_size);
		new_count++;
		new_bytes += abstract_size;
	}
	if (masks.deny2) {
		zfs_set_ace(aclp, zacep, masks.deny2, DENY, -1, OWNING_GROUP);
		zacep = (void *)((uintptr_t)zacep + abstract_size);
		new_count++;
		new_bytes += abstract_size;
	}

	while (acep = zfs_acl_next_ace(aclp, acep, &who, &access_mask,
	    &iflags, &type)) {
		entry_type = (iflags & ACE_TYPE_FLAGS);
		/*
		 * ACEs used to represent the file mode may be divided
		 * into an equivalent pair of inherit-only and regular
		 * ACEs, if they are inheritable.
		 * Skip regular ACEs, which are replaced by the new mode.
		 */
		if (split && (entry_type == ACE_OWNER ||
		    entry_type == OWNING_GROUP ||
		    entry_type == ACE_EVERYONE)) {
			if (!isdir || !(iflags &
			    (ACE_FILE_INHERIT_ACE|ACE_DIRECTORY_INHERIT_ACE)))
				continue;
			/*
			 * We preserve owner@, group@, or @everyone
			 * permissions, if they are inheritable, by
			 * copying them to inherit_only ACEs. This
			 * prevents inheritable permissions from being
			 * altered along with the file mode.
			 */
			iflags |= ACE_INHERIT_ONLY_ACE;
		}

		/*
		 * If this ACL has any inheritable ACEs, mark that in
		 * the hints (which are later masked into the pflags)
		 * so create knows to do inheritance.
		 */
		if (isdir && (iflags &
		    (ACE_FILE_INHERIT_ACE|ACE_DIRECTORY_INHERIT_ACE)))
			aclp->z_hints |= ZFS_INHERIT_ACE;

		if ((type != ALLOW && type != DENY) ||
		    (iflags & ACE_INHERIT_ONLY_ACE)) {
			switch (type) {
			case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
			case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
			case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
			case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
				aclp->z_hints |= ZFS_ACL_OBJ_ACE;
				break;
			}
		} else {
			/*
			 * Limit permissions granted by ACEs to be no greater
			 * than permissions of the requested group mode.
			 * Applies when the "aclmode" property is set to
			 * "groupmask".
			 */
			if ((type == ALLOW) && trim)
				access_mask &= masks.group;
		}
		zfs_set_ace(aclp, zacep, access_mask, type, who, iflags);
		ace_size = aclp->z_ops.ace_size(acep);
		zacep = (void *)((uintptr_t)zacep + ace_size);
		new_count++;
		new_bytes += ace_size;
	}
	zfs_set_ace(aclp, zacep, masks.owner, ALLOW, -1, ACE_OWNER);
	zacep = (void *)((uintptr_t)zacep + abstract_size);
	zfs_set_ace(aclp, zacep, masks.group, ALLOW, -1, OWNING_GROUP);
	zacep = (void *)((uintptr_t)zacep + abstract_size);
	zfs_set_ace(aclp, zacep, masks.everyone, ALLOW, -1, ACE_EVERYONE);

	new_count += 3;
	new_bytes += abstract_size * 3;
	zfs_acl_release_nodes(aclp);
	aclp->z_acl_count = new_count;
	aclp->z_acl_bytes = new_bytes;
	newnode->z_ace_count = new_count;
	newnode->z_size = new_bytes;
	list_insert_tail(&aclp->z_acl, newnode);
}

int
zfs_acl_chmod_setattr(znode_t *zp, zfs_acl_t **aclp, uint64_t mode)
{
	int error = 0;

	mutex_enter(&zp->z_acl_lock);
	mutex_enter(&zp->z_lock);
	if (zp->z_zfsvfs->z_acl_mode == ZFS_ACL_DISCARD)
		*aclp = zfs_acl_alloc(zfs_acl_version_zp(zp));
	else
		error = zfs_acl_node_read(zp, B_TRUE, aclp, B_TRUE);

	if (error == 0) {
		(*aclp)->z_hints = zp->z_pflags & V4_ACL_WIDE_FLAGS;
		zfs_acl_chmod(ZTOV(zp)->v_type, mode, B_TRUE,
		    (zp->z_zfsvfs->z_acl_mode == ZFS_ACL_GROUPMASK), *aclp);
	}
	mutex_exit(&zp->z_lock);
	mutex_exit(&zp->z_acl_lock);

	return (error);
}

/*
 * Should ACE be inherited?
 */
static int
zfs_ace_can_use(vtype_t vtype, uint16_t acep_flags)
{
	int	iflags = (acep_flags & 0xf);

	if ((vtype == VDIR) && (iflags & ACE_DIRECTORY_INHERIT_ACE))
		return (1);
	else if (iflags & ACE_FILE_INHERIT_ACE)
		return (!((vtype == VDIR) &&
		    (iflags & ACE_NO_PROPAGATE_INHERIT_ACE)));
	return (0);
}

/*
 * inherit inheritable ACEs from parent
 */
static zfs_acl_t *
zfs_acl_inherit(zfsvfs_t *zfsvfs, vtype_t vtype, zfs_acl_t *paclp,
    uint64_t mode, boolean_t *need_chmod)
{
	void		*pacep = NULL;
	void		*acep;
	zfs_acl_node_t  *aclnode;
	zfs_acl_t	*aclp = NULL;
	uint64_t	who;
	uint32_t	access_mask;
	uint16_t	iflags, newflags, type;
	size_t		ace_size;
	void		*data1, *data2;
	size_t		data1sz, data2sz;
	uint_t		aclinherit;
	boolean_t	isdir = (vtype == VDIR);
	boolean_t	isreg = (vtype == VREG);

	*need_chmod = B_TRUE;

	aclp = zfs_acl_alloc(paclp->z_version);
	aclinherit = zfsvfs->z_acl_inherit;
	if (aclinherit == ZFS_ACL_DISCARD || vtype == VLNK)
		return (aclp);

	while (pacep = zfs_acl_next_ace(paclp, pacep, &who,
	    &access_mask, &iflags, &type)) {

		/*
		 * don't inherit bogus ACEs
		 */
		if (!zfs_acl_valid_ace_type(type, iflags))
			continue;

		/*
		 * Check if ACE is inheritable by this vnode
		 */
		if ((aclinherit == ZFS_ACL_NOALLOW && type == ALLOW) ||
		    !zfs_ace_can_use(vtype, iflags))
			continue;

		/*
		 * If owner@, group@, or everyone@ inheritable
		 * then zfs_acl_chmod() isn't needed.
		 */
		if ((aclinherit == ZFS_ACL_PASSTHROUGH ||
		    aclinherit == ZFS_ACL_PASSTHROUGH_X) &&
		    ((iflags & (ACE_OWNER|ACE_EVERYONE)) ||
		    ((iflags & OWNING_GROUP) == OWNING_GROUP)) &&
		    (isreg || (isdir && (iflags & ACE_DIRECTORY_INHERIT_ACE))))
			*need_chmod = B_FALSE;

		/*
		 * Strip inherited execute permission from file if
		 * not in mode
		 */
		if (aclinherit == ZFS_ACL_PASSTHROUGH_X && type == ALLOW &&
		    !isdir && ((mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0)) {
			access_mask &= ~ACE_EXECUTE;
		}

		/*
		 * Strip write_acl and write_owner from permissions
		 * when inheriting an ACE
		 */
		if (aclinherit == ZFS_ACL_RESTRICTED && type == ALLOW) {
			access_mask &= ~RESTRICTED_CLEAR;
		}

		ace_size = aclp->z_ops.ace_size(pacep);
		aclnode = zfs_acl_node_alloc(ace_size);
		list_insert_tail(&aclp->z_acl, aclnode);
		acep = aclnode->z_acldata;

		zfs_set_ace(aclp, acep, access_mask, type,
		    who, iflags|ACE_INHERITED_ACE);

		/*
		 * Copy special opaque data if any
		 */
		if ((data1sz = paclp->z_ops.ace_data(pacep, &data1)) != 0) {
			VERIFY((data2sz = aclp->z_ops.ace_data(acep,
			    &data2)) == data1sz);
			bcopy(data1, data2, data2sz);
		}

		aclp->z_acl_count++;
		aclnode->z_ace_count++;
		aclp->z_acl_bytes += aclnode->z_size;
		newflags = aclp->z_ops.ace_flags_get(acep);

		/*
		 * If ACE is not to be inherited further, or if the vnode is
		 * not a directory, remove all inheritance flags
		 */
		if (!isdir || (iflags & ACE_NO_PROPAGATE_INHERIT_ACE)) {
			newflags &= ~ALL_INHERIT;
			aclp->z_ops.ace_flags_set(acep,
			    newflags|ACE_INHERITED_ACE);
			continue;
		}

		/*
		 * This directory has an inheritable ACE
		 */
		aclp->z_hints |= ZFS_INHERIT_ACE;

		/*
		 * If only FILE_INHERIT is set then turn on
		 * inherit_only
		 */
		if ((iflags & (ACE_FILE_INHERIT_ACE |
		    ACE_DIRECTORY_INHERIT_ACE)) == ACE_FILE_INHERIT_ACE) {
			newflags |= ACE_INHERIT_ONLY_ACE;
			aclp->z_ops.ace_flags_set(acep,
			    newflags|ACE_INHERITED_ACE);
		} else {
			newflags &= ~ACE_INHERIT_ONLY_ACE;
			aclp->z_ops.ace_flags_set(acep,
			    newflags|ACE_INHERITED_ACE);
		}
	}

	return (aclp);
}

/*
 * Create file system object initial permissions
 * including inheritable ACEs.
 * Also, create FUIDs for owner and group.
 */
int
zfs_acl_ids_create(znode_t *dzp, int flag, vattr_t *vap, cred_t *cr,
    vsecattr_t *vsecp, zfs_acl_ids_t *acl_ids)
{
	int		error;
	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
	zfs_acl_t	*paclp;
	gid_t		gid;
	boolean_t	need_chmod = B_TRUE;
	boolean_t	trim = B_FALSE;
	boolean_t	inherited = B_FALSE;

	bzero(acl_ids, sizeof (zfs_acl_ids_t));
	acl_ids->z_mode = MAKEIMODE(vap->va_type, vap->va_mode);

	if (vsecp)
		if ((error = zfs_vsec_2_aclp(zfsvfs, vap->va_type, vsecp, cr,
		    &acl_ids->z_fuidp, &acl_ids->z_aclp)) != 0)
			return (error);
	/*
	 * Determine uid and gid.
	 */
	if ((flag & IS_ROOT_NODE) || zfsvfs->z_replay ||
	    ((flag & IS_XATTR) && (vap->va_type == VDIR))) {
		acl_ids->z_fuid = zfs_fuid_create(zfsvfs,
		    (uint64_t)vap->va_uid, cr,
		    ZFS_OWNER, &acl_ids->z_fuidp);
		acl_ids->z_fgid = zfs_fuid_create(zfsvfs,
		    (uint64_t)vap->va_gid, cr,
		    ZFS_GROUP, &acl_ids->z_fuidp);
		gid = vap->va_gid;
	} else {
		acl_ids->z_fuid = zfs_fuid_create_cred(zfsvfs, ZFS_OWNER,
		    cr, &acl_ids->z_fuidp);
		acl_ids->z_fgid = 0;
		if (vap->va_mask & AT_GID)  {
			acl_ids->z_fgid = zfs_fuid_create(zfsvfs,
			    (uint64_t)vap->va_gid,
			    cr, ZFS_GROUP, &acl_ids->z_fuidp);
			gid = vap->va_gid;
			if (acl_ids->z_fgid != dzp->z_gid &&
			    !groupmember(vap->va_gid, cr) &&
			    secpolicy_vnode_create_gid(cr) != 0)
				acl_ids->z_fgid = 0;
		}
		if (acl_ids->z_fgid == 0) {
			if (dzp->z_mode & S_ISGID) {
				char		*domain;
				uint32_t	rid;

				acl_ids->z_fgid = dzp->z_gid;
				gid = zfs_fuid_map_id(zfsvfs, acl_ids->z_fgid,
				    cr, ZFS_GROUP);

				if (zfsvfs->z_use_fuids &&
				    IS_EPHEMERAL(acl_ids->z_fgid)) {
					domain = zfs_fuid_idx_domain(
					    &zfsvfs->z_fuid_idx,
					    FUID_INDEX(acl_ids->z_fgid));
					rid = FUID_RID(acl_ids->z_fgid);
					zfs_fuid_node_add(&acl_ids->z_fuidp,
					    domain, rid,
					    FUID_INDEX(acl_ids->z_fgid),
					    acl_ids->z_fgid, ZFS_GROUP);
				}
			} else {
				acl_ids->z_fgid = zfs_fuid_create_cred(zfsvfs,
				    ZFS_GROUP, cr, &acl_ids->z_fuidp);
				gid = crgetgid(cr);
			}
		}
	}

	/*
	 * If we're creating a directory, and the parent directory has the
	 * set-GID bit set, set in on the new directory.
	 * Otherwise, if the user is neither privileged nor a member of the
	 * file's new group, clear the file's set-GID bit.
	 */

	if (!(flag & IS_ROOT_NODE) && (dzp->z_mode & S_ISGID) &&
	    (vap->va_type == VDIR)) {
		acl_ids->z_mode |= S_ISGID;
	} else {
		if ((acl_ids->z_mode & S_ISGID) &&
		    secpolicy_vnode_setids_setgids(cr, gid) != 0)
			acl_ids->z_mode &= ~S_ISGID;
	}

	if (acl_ids->z_aclp == NULL) {
		mutex_enter(&dzp->z_acl_lock);
		mutex_enter(&dzp->z_lock);
		if (!(flag & IS_ROOT_NODE) &&
		    (dzp->z_pflags & ZFS_INHERIT_ACE) &&
		    !(dzp->z_pflags & ZFS_XATTR)) {
			VERIFY(0 == zfs_acl_node_read(dzp, B_TRUE,
			    &paclp, B_FALSE));
			acl_ids->z_aclp = zfs_acl_inherit(zfsvfs,
			    vap->va_type, paclp, acl_ids->z_mode, &need_chmod);
			inherited = B_TRUE;
		} else {
			acl_ids->z_aclp =
			    zfs_acl_alloc(zfs_acl_version_zp(dzp));
			acl_ids->z_aclp->z_hints |= ZFS_ACL_TRIVIAL;
		}
		mutex_exit(&dzp->z_lock);
		mutex_exit(&dzp->z_acl_lock);

		if (need_chmod) {
			if (vap->va_type == VDIR)
				acl_ids->z_aclp->z_hints |=
				    ZFS_ACL_AUTO_INHERIT;

			if (zfsvfs->z_acl_mode == ZFS_ACL_GROUPMASK &&
			    zfsvfs->z_acl_inherit != ZFS_ACL_PASSTHROUGH &&
			    zfsvfs->z_acl_inherit != ZFS_ACL_PASSTHROUGH_X)
				trim = B_TRUE;
			zfs_acl_chmod(vap->va_type, acl_ids->z_mode, B_FALSE,
			    trim, acl_ids->z_aclp);
		}
	}

	if (inherited || vsecp) {
		acl_ids->z_mode = zfs_mode_compute(acl_ids->z_mode,
		    acl_ids->z_aclp, &acl_ids->z_aclp->z_hints,
		    acl_ids->z_fuid, acl_ids->z_fgid);
		if (ace_trivial_common(acl_ids->z_aclp, 0, zfs_ace_walk) == 0)
			acl_ids->z_aclp->z_hints |= ZFS_ACL_TRIVIAL;
	}

	return (0);
}

/*
 * Free ACL and fuid_infop, but not the acl_ids structure
 */
void
zfs_acl_ids_free(zfs_acl_ids_t *acl_ids)
{
	if (acl_ids->z_aclp)
		zfs_acl_free(acl_ids->z_aclp);
	if (acl_ids->z_fuidp)
		zfs_fuid_info_free(acl_ids->z_fuidp);
	acl_ids->z_aclp = NULL;
	acl_ids->z_fuidp = NULL;
}

boolean_t
zfs_acl_ids_overquota(zfsvfs_t *zv, zfs_acl_ids_t *acl_ids, uint64_t projid)
{
	return (zfs_id_overquota(zv, DMU_USERUSED_OBJECT, acl_ids->z_fuid) ||
	    zfs_id_overquota(zv, DMU_GROUPUSED_OBJECT, acl_ids->z_fgid) ||
	    (projid != ZFS_DEFAULT_PROJID && projid != ZFS_INVALID_PROJID &&
	    zfs_id_overquota(zv, DMU_PROJECTUSED_OBJECT, projid)));
}

/*
 * Retrieve a file's ACL
 */
int
zfs_getacl(znode_t *zp, vsecattr_t *vsecp, boolean_t skipaclchk, cred_t *cr)
{
	zfs_acl_t	*aclp;
	ulong_t		mask;
	int		error;
	int		count = 0;
	int		largeace = 0;

	mask = vsecp->vsa_mask & (VSA_ACE | VSA_ACECNT |
	    VSA_ACE_ACLFLAGS | VSA_ACE_ALLTYPES);

	if (mask == 0)
		return (SET_ERROR(ENOSYS));

	if (error = zfs_zaccess(zp, ACE_READ_ACL, 0, skipaclchk, cr))
		return (error);

	mutex_enter(&zp->z_acl_lock);

	error = zfs_acl_node_read(zp, B_FALSE, &aclp, B_FALSE);
	if (error != 0) {
		mutex_exit(&zp->z_acl_lock);
		return (error);
	}

	/*
	 * Scan ACL to determine number of ACEs
	 */
	if ((zp->z_pflags & ZFS_ACL_OBJ_ACE) && !(mask & VSA_ACE_ALLTYPES)) {
		void *zacep = NULL;
		uint64_t who;
		uint32_t access_mask;
		uint16_t type, iflags;

		while (zacep = zfs_acl_next_ace(aclp, zacep,
		    &who, &access_mask, &iflags, &type)) {
			switch (type) {
			case ACE_ACCESS_ALLOWED_OBJECT_ACE_TYPE:
			case ACE_ACCESS_DENIED_OBJECT_ACE_TYPE:
			case ACE_SYSTEM_AUDIT_OBJECT_ACE_TYPE:
			case ACE_SYSTEM_ALARM_OBJECT_ACE_TYPE:
				largeace++;
				continue;
			default:
				count++;
			}
		}
		vsecp->vsa_aclcnt = count;
	} else
		count = (int)aclp->z_acl_count;

	if (mask & VSA_ACECNT) {
		vsecp->vsa_aclcnt = count;
	}

	if (mask & VSA_ACE) {
		size_t aclsz;

		aclsz = count * sizeof (ace_t) +
		    sizeof (ace_object_t) * largeace;

		vsecp->vsa_aclentp = kmem_alloc(aclsz, KM_SLEEP);
		vsecp->vsa_aclentsz = aclsz;

		if (aclp->z_version == ZFS_ACL_VERSION_FUID)
			zfs_copy_fuid_2_ace(zp->z_zfsvfs, aclp, cr,
			    vsecp->vsa_aclentp, !(mask & VSA_ACE_ALLTYPES));
		else {
			zfs_acl_node_t *aclnode;
			void *start = vsecp->vsa_aclentp;

			for (aclnode = list_head(&aclp->z_acl); aclnode;
			    aclnode = list_next(&aclp->z_acl, aclnode)) {
				bcopy(aclnode->z_acldata, start,
				    aclnode->z_size);
				start = (caddr_t)start + aclnode->z_size;
			}
			ASSERT((caddr_t)start - (caddr_t)vsecp->vsa_aclentp ==
			    aclp->z_acl_bytes);
		}
	}
	if (mask & VSA_ACE_ACLFLAGS) {
		vsecp->vsa_aclflags = 0;
		if (zp->z_pflags & ZFS_ACL_DEFAULTED)
			vsecp->vsa_aclflags |= ACL_DEFAULTED;
		if (zp->z_pflags & ZFS_ACL_PROTECTED)
			vsecp->vsa_aclflags |= ACL_PROTECTED;
		if (zp->z_pflags & ZFS_ACL_AUTO_INHERIT)
			vsecp->vsa_aclflags |= ACL_AUTO_INHERIT;
	}

	mutex_exit(&zp->z_acl_lock);

	return (0);
}

int
zfs_vsec_2_aclp(zfsvfs_t *zfsvfs, vtype_t obj_type,
    vsecattr_t *vsecp, cred_t *cr, zfs_fuid_info_t **fuidp, zfs_acl_t **zaclp)
{
	zfs_acl_t *aclp;
	zfs_acl_node_t *aclnode;
	int aclcnt = vsecp->vsa_aclcnt;
	int error;

	if (vsecp->vsa_aclcnt > MAX_ACL_ENTRIES || vsecp->vsa_aclcnt <= 0)
		return (SET_ERROR(EINVAL));

	aclp = zfs_acl_alloc(zfs_acl_version(zfsvfs->z_version));

	aclp->z_hints = 0;
	aclnode = zfs_acl_node_alloc(aclcnt * sizeof (zfs_object_ace_t));
	if (aclp->z_version == ZFS_ACL_VERSION_INITIAL) {
		if ((error = zfs_copy_ace_2_oldace(obj_type, aclp,
		    (ace_t *)vsecp->vsa_aclentp, aclnode->z_acldata,
		    aclcnt, &aclnode->z_size)) != 0) {
			zfs_acl_free(aclp);
			zfs_acl_node_free(aclnode);
			return (error);
		}
	} else {
		if ((error = zfs_copy_ace_2_fuid(zfsvfs, obj_type, aclp,
		    vsecp->vsa_aclentp, aclnode->z_acldata, aclcnt,
		    &aclnode->z_size, fuidp, cr)) != 0) {
			zfs_acl_free(aclp);
			zfs_acl_node_free(aclnode);
			return (error);
		}
	}
	aclp->z_acl_bytes = aclnode->z_size;
	aclnode->z_ace_count = aclcnt;
	aclp->z_acl_count = aclcnt;
	list_insert_head(&aclp->z_acl, aclnode);

	/*
	 * If flags are being set then add them to z_hints
	 */
	if (vsecp->vsa_mask & VSA_ACE_ACLFLAGS) {
		if (vsecp->vsa_aclflags & ACL_PROTECTED)
			aclp->z_hints |= ZFS_ACL_PROTECTED;
		if (vsecp->vsa_aclflags & ACL_DEFAULTED)
			aclp->z_hints |= ZFS_ACL_DEFAULTED;
		if (vsecp->vsa_aclflags & ACL_AUTO_INHERIT)
			aclp->z_hints |= ZFS_ACL_AUTO_INHERIT;
	}

	*zaclp = aclp;

	return (0);
}

/*
 * Set a file's ACL
 */
int
zfs_setacl(znode_t *zp, vsecattr_t *vsecp, boolean_t skipaclchk, cred_t *cr)
{
	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
	zilog_t		*zilog = zfsvfs->z_log;
	ulong_t		mask = vsecp->vsa_mask & (VSA_ACE | VSA_ACECNT);
	dmu_tx_t	*tx;
	int		error;
	zfs_acl_t	*aclp;
	zfs_fuid_info_t	*fuidp = NULL;
	boolean_t	fuid_dirtied;
	uint64_t	acl_obj;

	if (mask == 0)
		return (SET_ERROR(ENOSYS));

	if (zp->z_pflags & ZFS_IMMUTABLE)
		return (SET_ERROR(EPERM));

	if (error = zfs_zaccess(zp, ACE_WRITE_ACL, 0, skipaclchk, cr))
		return (error);

	error = zfs_vsec_2_aclp(zfsvfs, ZTOV(zp)->v_type, vsecp, cr, &fuidp,
	    &aclp);
	if (error)
		return (error);

	/*
	 * If ACL wide flags aren't being set then preserve any
	 * existing flags.
	 */
	if (!(vsecp->vsa_mask & VSA_ACE_ACLFLAGS)) {
		aclp->z_hints |=
		    (zp->z_pflags & V4_ACL_WIDE_FLAGS);
	}
top:
	mutex_enter(&zp->z_acl_lock);
	mutex_enter(&zp->z_lock);

	tx = dmu_tx_create(zfsvfs->z_os);

	dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_TRUE);

	fuid_dirtied = zfsvfs->z_fuid_dirty;
	if (fuid_dirtied)
		zfs_fuid_txhold(zfsvfs, tx);

	/*
	 * If old version and ACL won't fit in bonus and we aren't
	 * upgrading then take out necessary DMU holds
	 */

	if ((acl_obj = zfs_external_acl(zp)) != 0) {
		if (zfsvfs->z_version >= ZPL_VERSION_FUID &&
		    zfs_znode_acl_version(zp) <= ZFS_ACL_VERSION_INITIAL) {
			dmu_tx_hold_free(tx, acl_obj, 0,
			    DMU_OBJECT_END);
			dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
			    aclp->z_acl_bytes);
		} else {
			dmu_tx_hold_write(tx, acl_obj, 0, aclp->z_acl_bytes);
		}
	} else if (!zp->z_is_sa && aclp->z_acl_bytes > ZFS_ACE_SPACE) {
		dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, aclp->z_acl_bytes);
	}

	zfs_sa_upgrade_txholds(tx, zp);
	error = dmu_tx_assign(tx, TXG_NOWAIT);
	if (error) {
		mutex_exit(&zp->z_acl_lock);
		mutex_exit(&zp->z_lock);

		if (error == ERESTART) {
			dmu_tx_wait(tx);
			dmu_tx_abort(tx);
			goto top;
		}
		dmu_tx_abort(tx);
		zfs_acl_free(aclp);
		return (error);
	}

	error = zfs_aclset_common(zp, aclp, cr, tx);
	ASSERT(error == 0);
	ASSERT(zp->z_acl_cached == NULL);
	zp->z_acl_cached = aclp;

	if (fuid_dirtied)
		zfs_fuid_sync(zfsvfs, tx);

	zfs_log_acl(zilog, tx, zp, vsecp, fuidp);

	if (fuidp)
		zfs_fuid_info_free(fuidp);
	dmu_tx_commit(tx);
done:
	mutex_exit(&zp->z_lock);
	mutex_exit(&zp->z_acl_lock);

	return (error);
}

/*
 * Check accesses of interest (AoI) against attributes of the dataset
 * such as read-only.  Returns zero if no AoI conflict with dataset
 * attributes, otherwise an appropriate errno is returned.
 */
static int
zfs_zaccess_dataset_check(znode_t *zp, uint32_t v4_mode)
{
	if ((v4_mode & WRITE_MASK) &&
	    (zp->z_zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) &&
	    (!IS_DEVVP(ZTOV(zp)) ||
	    (IS_DEVVP(ZTOV(zp)) && (v4_mode & WRITE_MASK_ATTRS)))) {
		return (SET_ERROR(EROFS));
	}

	/*
	 * Intentionally allow ZFS_READONLY through here.
	 * See zfs_zaccess_common().
	 */
	if ((v4_mode & WRITE_MASK_DATA) &&
	    (zp->z_pflags & ZFS_IMMUTABLE)) {
		return (SET_ERROR(EPERM));
	}

	if ((v4_mode & (ACE_DELETE | ACE_DELETE_CHILD)) &&
	    (zp->z_pflags & ZFS_NOUNLINK)) {
		return (SET_ERROR(EPERM));
	}

	if (((v4_mode & (ACE_READ_DATA|ACE_EXECUTE)) &&
	    (zp->z_pflags & ZFS_AV_QUARANTINED))) {
		return (SET_ERROR(EACCES));
	}

	return (0);
}

/*
 * The primary usage of this function is to loop through all of the
 * ACEs in the znode, determining what accesses of interest (AoI) to
 * the caller are allowed or denied.  The AoI are expressed as bits in
 * the working_mode parameter.  As each ACE is processed, bits covered
 * by that ACE are removed from the working_mode.  This removal
 * facilitates two things.  The first is that when the working mode is
 * empty (= 0), we know we've looked at all the AoI. The second is
 * that the ACE interpretation rules don't allow a later ACE to undo
 * something granted or denied by an earlier ACE.  Removing the
 * discovered access or denial enforces this rule.  At the end of
 * processing the ACEs, all AoI that were found to be denied are
 * placed into the working_mode, giving the caller a mask of denied
 * accesses.  Returns:
 *	0		if all AoI granted
 *	EACCES		if the denied mask is non-zero
 *	other error	if abnormal failure (e.g., IO error)
 *
 * A secondary usage of the function is to determine if any of the
 * AoI are granted.  If an ACE grants any access in
 * the working_mode, we immediately short circuit out of the function.
 * This mode is chosen by setting anyaccess to B_TRUE.  The
 * working_mode is not a denied access mask upon exit if the function
 * is used in this manner.
 */
static int
zfs_zaccess_aces_check(znode_t *zp, uint32_t *working_mode,
    boolean_t anyaccess, cred_t *cr)
{
	zfsvfs_t	*zfsvfs = zp->z_zfsvfs;
	zfs_acl_t	*aclp;
	int		error;
	uint64_t	who;		/* FUID from the ACE */
	uint16_t	type, iflags;
	uint16_t	entry_type;
	uint32_t	access_mask;
	uint32_t	deny_mask = 0;
	zfs_ace_hdr_t	*acep = NULL;
	boolean_t	checkit;	/* ACE ID matches */

	mutex_enter(&zp->z_acl_lock);

	error = zfs_acl_node_read(zp, B_FALSE, &aclp, B_FALSE);
	if (error != 0) {
		mutex_exit(&zp->z_acl_lock);
		return (error);
	}

	ASSERT(zp->z_acl_cached);

	while (acep = zfs_acl_next_ace(aclp, acep, &who, &access_mask,
	    &iflags, &type)) {
		uint32_t mask_matched;

		if (!zfs_acl_valid_ace_type(type, iflags))
			continue;

		if (ZTOV(zp)->v_type == VDIR && (iflags & ACE_INHERIT_ONLY_ACE))
			continue;

		/* Skip ACE if it does not affect any AoI */
		mask_matched = (access_mask & *working_mode);
		if (!mask_matched)
			continue;

		entry_type = (iflags & ACE_TYPE_FLAGS);

		checkit = B_FALSE;

		switch (entry_type) {
		case ACE_OWNER:
			who = zp->z_uid;
			/*FALLTHROUGH*/
		case 0:	/* USER Entry */
			checkit = zfs_user_in_cred(zfsvfs, who, cr);
			break;
		case OWNING_GROUP:
			who = zp->z_gid;
			/*FALLTHROUGH*/
		case ACE_IDENTIFIER_GROUP:
			checkit = zfs_groupmember(zfsvfs, who, cr);
			break;
		case ACE_EVERYONE:
			checkit = B_TRUE;
			break;

		default:
			/*
			 * The zfs_acl_valid_ace_type check above
			 * should make this case impossible.
			 */
			mutex_exit(&zp->z_acl_lock);
			return (SET_ERROR(EIO));
		}

		if (checkit) {
			if (type == DENY) {
				DTRACE_PROBE3(zfs__ace__denies,
				    znode_t *, zp,
				    zfs_ace_hdr_t *, acep,
				    uint32_t, mask_matched);
				deny_mask |= mask_matched;
			} else {
				DTRACE_PROBE3(zfs__ace__allows,
				    znode_t *, zp,
				    zfs_ace_hdr_t *, acep,
				    uint32_t, mask_matched);
				if (anyaccess) {
					mutex_exit(&zp->z_acl_lock);
					return (0);
				}
			}
			*working_mode &= ~mask_matched;
		}

		/* Are we done? */
		if (*working_mode == 0)
			break;
	}

	mutex_exit(&zp->z_acl_lock);

	/* Put the found 'denies' back on the working mode */
	if (deny_mask) {
		*working_mode |= deny_mask;
		return (SET_ERROR(EACCES));
	} else if (*working_mode) {
		return (-1);
	}

	return (0);
}

/*
 * Return true if any access whatsoever granted, we don't actually
 * care what access is granted.
 */
boolean_t
zfs_has_access(znode_t *zp, cred_t *cr)
{
	uint32_t have = ACE_ALL_PERMS;

	if (zfs_zaccess_aces_check(zp, &have, B_TRUE, cr) != 0) {
		uid_t owner;

		owner = zfs_fuid_map_id(zp->z_zfsvfs, zp->z_uid, cr, ZFS_OWNER);
		return (secpolicy_vnode_any_access(cr, ZTOV(zp), owner) == 0);
	}
	return (B_TRUE);
}

static int
zfs_zaccess_common(znode_t *zp, uint32_t v4_mode, uint32_t *working_mode,
    boolean_t *check_privs, boolean_t skipaclchk, cred_t *cr)
{
	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
	int err;

	*working_mode = v4_mode;
	*check_privs = B_TRUE;

	/*
	 * Short circuit empty requests
	 */
	if (v4_mode == 0 || zfsvfs->z_replay) {
		*working_mode = 0;
		return (0);
	}

	if ((err = zfs_zaccess_dataset_check(zp, v4_mode)) != 0) {
		*check_privs = B_FALSE;
		return (err);
	}

	/*
	 * The caller requested that the ACL check be skipped.  This
	 * would only happen if the caller checked VOP_ACCESS() with a
	 * 32 bit ACE mask and already had the appropriate permissions.
	 */
	if (skipaclchk) {
		*working_mode = 0;
		return (0);
	}

	/*
	 * Note: ZFS_READONLY represents the "DOS R/O" attribute.
	 * When that flag is set, we should behave as if write access
	 * were not granted by anything in the ACL.  In particular:
	 * We _must_ allow writes after opening the file r/w, then
	 * setting the DOS R/O attribute, and writing some more.
	 * (Similar to how you can write after fchmod(fd, 0444).)
	 *
	 * Therefore ZFS_READONLY is ignored in the dataset check
	 * above, and checked here as if part of the ACL check.
	 * Also note: DOS R/O is ignored for directories.
	 */
	if ((v4_mode & WRITE_MASK_DATA) &&
	    (ZTOV(zp)->v_type != VDIR) &&
	    (zp->z_pflags & ZFS_READONLY)) {
		return (SET_ERROR(EPERM));
	}

	return (zfs_zaccess_aces_check(zp, working_mode, B_FALSE, cr));
}

static int
zfs_zaccess_append(znode_t *zp, uint32_t *working_mode, boolean_t *check_privs,
    cred_t *cr)
{
	if (*working_mode != ACE_WRITE_DATA)
		return (SET_ERROR(EACCES));

	return (zfs_zaccess_common(zp, ACE_APPEND_DATA, working_mode,
	    check_privs, B_FALSE, cr));
}

int
zfs_fastaccesschk_execute(znode_t *zdp, cred_t *cr, boolean_t skipaclchk)
{
	boolean_t owner = B_FALSE;
	boolean_t groupmbr = B_FALSE;
	boolean_t is_attr;
	uid_t uid = crgetuid(cr);
	int error;

	if (zdp->z_pflags & ZFS_AV_QUARANTINED)
		return (SET_ERROR(EACCES));

	is_attr = ((zdp->z_pflags & ZFS_XATTR) &&
	    (ZTOV(zdp)->v_type == VDIR));
	if (is_attr)
		goto slow;


	mutex_enter(&zdp->z_acl_lock);

	if (zdp->z_pflags & ZFS_NO_EXECS_DENIED) {
		mutex_exit(&zdp->z_acl_lock);
		return (0);
	}

	if (FUID_INDEX(zdp->z_uid) != 0 || FUID_INDEX(zdp->z_gid) != 0) {
		mutex_exit(&zdp->z_acl_lock);
		goto slow;
	}

	if (uid == zdp->z_uid) {
		owner = B_TRUE;
		if (zdp->z_mode & S_IXUSR) {
			mutex_exit(&zdp->z_acl_lock);
			return (0);
		} else {
			mutex_exit(&zdp->z_acl_lock);
			goto slow;
		}
	}
	if (groupmember(zdp->z_gid, cr)) {
		groupmbr = B_TRUE;
		if (zdp->z_mode & S_IXGRP) {
			mutex_exit(&zdp->z_acl_lock);
			return (0);
		} else {
			mutex_exit(&zdp->z_acl_lock);
			goto slow;
		}
	}
	if (!owner && !groupmbr) {
		if (zdp->z_mode & S_IXOTH) {
			mutex_exit(&zdp->z_acl_lock);
			return (0);
		}
	}

	mutex_exit(&zdp->z_acl_lock);

slow:
	DTRACE_PROBE(zfs__fastpath__execute__access__miss);
	ZFS_ENTER(zdp->z_zfsvfs);
	error = zfs_zaccess(zdp, ACE_EXECUTE, 0, skipaclchk, cr);
	ZFS_EXIT(zdp->z_zfsvfs);
	return (error);
}

/*
 * Determine whether Access should be granted/denied.
 *
 * The least priv subsystem is always consulted as a basic privilege
 * can define any form of access.
 */
int
zfs_zaccess(znode_t *zp, int mode, int flags, boolean_t skipaclchk, cred_t *cr)
{
	uint32_t	working_mode;
	int		error;
	int		is_attr;
	boolean_t	check_privs;
	znode_t		*xzp;
	znode_t		*check_zp = zp;
	mode_t		needed_bits;
	uid_t		owner;

	is_attr = ((zp->z_pflags & ZFS_XATTR) && (ZTOV(zp)->v_type == VDIR));

	/*
	 * If attribute then validate against base file
	 */
	if (is_attr) {
		uint64_t	parent;

		if ((error = sa_lookup(zp->z_sa_hdl,
		    SA_ZPL_PARENT(zp->z_zfsvfs), &parent,
		    sizeof (parent))) != 0)
			return (error);

		if ((error = zfs_zget(zp->z_zfsvfs,
		    parent, &xzp)) != 0)	{
			return (error);
		}

		check_zp = xzp;

		/*
		 * fixup mode to map to xattr perms
		 */

		if (mode & (ACE_WRITE_DATA|ACE_APPEND_DATA)) {
			mode &= ~(ACE_WRITE_DATA|ACE_APPEND_DATA);
			mode |= ACE_WRITE_NAMED_ATTRS;
		}

		if (mode & (ACE_READ_DATA|ACE_EXECUTE)) {
			mode &= ~(ACE_READ_DATA|ACE_EXECUTE);
			mode |= ACE_READ_NAMED_ATTRS;
		}
	}

	owner = zfs_fuid_map_id(zp->z_zfsvfs, zp->z_uid, cr, ZFS_OWNER);
	/*
	 * Map the bits required to the standard vnode flags VREAD|VWRITE|VEXEC
	 * in needed_bits.  Map the bits mapped by working_mode (currently
	 * missing) in missing_bits.
	 * Call secpolicy_vnode_access2() with (needed_bits & ~checkmode),
	 * needed_bits.
	 */
	needed_bits = 0;

	working_mode = mode;

	if ((working_mode & (ACE_READ_ACL|ACE_READ_ATTRIBUTES)) &&
	    owner == crgetuid(cr))
		working_mode &= ~(ACE_READ_ACL|ACE_READ_ATTRIBUTES);

	if (working_mode & (ACE_READ_DATA|ACE_READ_NAMED_ATTRS|
	    ACE_READ_ACL|ACE_READ_ATTRIBUTES|ACE_SYNCHRONIZE))
		needed_bits |= VREAD;
	if (working_mode & (ACE_WRITE_DATA|ACE_WRITE_NAMED_ATTRS|
	    ACE_APPEND_DATA|ACE_WRITE_ATTRIBUTES|ACE_SYNCHRONIZE))
		needed_bits |= VWRITE;
	if (working_mode & ACE_EXECUTE)
		needed_bits |= VEXEC;

	if ((error = zfs_zaccess_common(check_zp, mode, &working_mode,
	    &check_privs, skipaclchk, cr)) == 0) {
		if (is_attr)
			VN_RELE(ZTOV(xzp));
		return (secpolicy_vnode_access2(cr, ZTOV(zp), owner,
		    needed_bits, needed_bits));
	}

	if (error && !check_privs) {
		if (is_attr)
			VN_RELE(ZTOV(xzp));
		return (error);
	}

	if (error && (flags & V_APPEND)) {
		error = zfs_zaccess_append(zp, &working_mode, &check_privs, cr);
	}

	if (error && check_privs) {
		mode_t		checkmode = 0;

		/*
		 * First check for implicit owner permission on
		 * read_acl/read_attributes
		 */

		error = 0;
		ASSERT(working_mode != 0);

		if ((working_mode & (ACE_READ_ACL|ACE_READ_ATTRIBUTES) &&
		    owner == crgetuid(cr)))
			working_mode &= ~(ACE_READ_ACL|ACE_READ_ATTRIBUTES);

		if (working_mode & (ACE_READ_DATA|ACE_READ_NAMED_ATTRS|
		    ACE_READ_ACL|ACE_READ_ATTRIBUTES|ACE_SYNCHRONIZE))
			checkmode |= VREAD;
		if (working_mode & (ACE_WRITE_DATA|ACE_WRITE_NAMED_ATTRS|
		    ACE_APPEND_DATA|ACE_WRITE_ATTRIBUTES|ACE_SYNCHRONIZE))
			checkmode |= VWRITE;
		if (working_mode & ACE_EXECUTE)
			checkmode |= VEXEC;

		error = secpolicy_vnode_access2(cr, ZTOV(check_zp), owner,
		    needed_bits & ~checkmode, needed_bits);

		if (error == 0 && (working_mode & ACE_WRITE_OWNER))
			error = secpolicy_vnode_chown(cr, owner);
		if (error == 0 && (working_mode & ACE_WRITE_ACL))
			error = secpolicy_vnode_setdac3(cr, owner,
			    zp->z_zfsvfs->z_acl_implicit);

		if (error == 0 && (working_mode &
		    (ACE_DELETE|ACE_DELETE_CHILD)))
			error = secpolicy_vnode_remove(cr);

		if (error == 0 && (working_mode & ACE_SYNCHRONIZE)) {
			error = secpolicy_vnode_chown(cr, owner);
		}
		if (error == 0) {
			/*
			 * See if any bits other than those already checked
			 * for are still present.  If so then return EACCES
			 */
			if (working_mode & ~(ZFS_CHECKED_MASKS)) {
				error = SET_ERROR(EACCES);
			}
		}
	} else if (error == 0) {
		error = secpolicy_vnode_access2(cr, ZTOV(zp), owner,
		    needed_bits, needed_bits);
	}


	if (is_attr)
		VN_RELE(ZTOV(xzp));

	return (error);
}

/*
 * Translate traditional unix VREAD/VWRITE/VEXEC mode into
 * native ACL format and call zfs_zaccess()
 */
int
zfs_zaccess_rwx(znode_t *zp, mode_t mode, int flags, cred_t *cr)
{
	return (zfs_zaccess(zp, zfs_unix_to_v4(mode >> 6), flags, B_FALSE, cr));
}

/*
 * Access function for secpolicy_vnode_setattr
 */
int
zfs_zaccess_unix(znode_t *zp, mode_t mode, cred_t *cr)
{
	int v4_mode = zfs_unix_to_v4(mode >> 6);

	return (zfs_zaccess(zp, v4_mode, 0, B_FALSE, cr));
}

/* See zfs_zaccess_delete() */
int zfs_write_implies_delete_child = 1;

/*
 * Determine whether delete access should be granted.
 *
 * The following chart outlines how we handle delete permissions which is
 * how recent versions of windows (Windows 2008) handles it.  The efficiency
 * comes from not having to check the parent ACL where the object itself grants
 * delete:
 *
 *      -------------------------------------------------------
 *      |   Parent Dir  |      Target Object Permissions      |
 *      |  permissions  |                                     |
 *      -------------------------------------------------------
 *      |               | ACL Allows | ACL Denies| Delete     |
 *      |               |  Delete    |  Delete   | unspecified|
 *      -------------------------------------------------------
 *      | ACL Allows    | Permit     | Deny *    | Permit     |
 *      | DELETE_CHILD  |            |           |            |
 *      -------------------------------------------------------
 *      | ACL Denies    | Permit     | Deny      | Deny       |
 *      | DELETE_CHILD  |            |           |            |
 *      -------------------------------------------------------
 *      | ACL specifies |            |           |            |
 *      | only allow    | Permit     | Deny *    | Permit     |
 *      | write and     |            |           |            |
 *      | execute       |            |           |            |
 *      -------------------------------------------------------
 *      | ACL denies    |            |           |            |
 *      | write and     | Permit     | Deny      | Deny       |
 *      | execute       |            |           |            |
 *      -------------------------------------------------------
 *         ^
 *         |
 *         Re. execute permission on the directory:  if that's missing,
 *	   the vnode lookup of the target will fail before we get here.
 *
 * Re [*] in the table above:  NFSv4 would normally Permit delete for
 * these two cells of the matrix.
 * See acl.h for notes on which ACE_... flags should be checked for which
 * operations.  Specifically, the NFSv4 committee recommendation is in
 * conflict with the Windows interpretation of DENY ACEs, where DENY ACEs
 * should take precedence ahead of ALLOW ACEs.
 *
 * This implementation always consults the target object's ACL first.
 * If a DENY ACE is present on the target object that specifies ACE_DELETE,
 * delete access is denied.  If an ALLOW ACE with ACE_DELETE is present on
 * the target object, access is allowed.  If and only if no entries with
 * ACE_DELETE are present in the object's ACL, check the container's ACL
 * for entries with ACE_DELETE_CHILD.
 *
 * A summary of the logic implemented from the table above is as follows:
 *
 * First check for DENY ACEs that apply.
 * If either target or container has a deny, EACCES.
 *
 * Delete access can then be summarized as follows:
 * 1: The object to be deleted grants ACE_DELETE, or
 * 2: The containing directory grants ACE_DELETE_CHILD.
 * In a Windows system, that would be the end of the story.
 * In this system, (2) has some complications...
 * 2a: "sticky" bit on a directory adds restrictions, and
 * 2b: existing ACEs from previous versions of ZFS may
 * not carry ACE_DELETE_CHILD where they should, so we
 * also allow delete when ACE_WRITE_DATA is granted.
 *
 * Note: 2b is technically a work-around for a prior bug,
 * which hopefully can go away some day.  For those who
 * no longer need the work around, and for testing, this
 * work-around is made conditional via the tunable:
 * zfs_write_implies_delete_child
 */
int
zfs_zaccess_delete(znode_t *dzp, znode_t *zp, cred_t *cr)
{
	uint32_t wanted_dirperms;
	uint32_t dzp_working_mode = 0;
	uint32_t zp_working_mode = 0;
	int dzp_error, zp_error;
	boolean_t dzpcheck_privs;
	boolean_t zpcheck_privs;

	if (zp->z_pflags & (ZFS_IMMUTABLE | ZFS_NOUNLINK))
		return (SET_ERROR(EPERM));

	/*
	 * Case 1:
	 * If target object grants ACE_DELETE then we are done.  This is
	 * indicated by a return value of 0.  For this case we don't worry
	 * about the sticky bit because sticky only applies to the parent
	 * directory and this is the child access result.
	 *
	 * If we encounter a DENY ACE here, we're also done (EACCES).
	 * Note that if we hit a DENY ACE here (on the target) it should
	 * take precedence over a DENY ACE on the container, so that when
	 * we have more complete auditing support we will be able to
	 * report an access failure against the specific target.
	 * (This is part of why we're checking the target first.)
	 */
	zp_error = zfs_zaccess_common(zp, ACE_DELETE, &zp_working_mode,
	    &zpcheck_privs, B_FALSE, cr);
	if (zp_error == EACCES) {
		/* We hit a DENY ACE. */
		if (!zpcheck_privs)
			return (SET_ERROR(zp_error));
		return (secpolicy_vnode_remove(cr));

	}
	if (zp_error == 0)
		return (0);

	/*
	 * Case 2:
	 * If the containing directory grants ACE_DELETE_CHILD,
	 * or we're in backward compatibility mode and the
	 * containing directory has ACE_WRITE_DATA, allow.
	 * Case 2b is handled with wanted_dirperms.
	 */
	wanted_dirperms = ACE_DELETE_CHILD;
	if (zfs_write_implies_delete_child)
		wanted_dirperms |= ACE_WRITE_DATA;
	dzp_error = zfs_zaccess_common(dzp, wanted_dirperms,
	    &dzp_working_mode, &dzpcheck_privs, B_FALSE, cr);
	if (dzp_error == EACCES) {
		/* We hit a DENY ACE. */
		if (!dzpcheck_privs)
			return (SET_ERROR(dzp_error));
		return (secpolicy_vnode_remove(cr));
	}

	/*
	 * Cases 2a, 2b (continued)
	 *
	 * Note: dzp_working_mode now contains any permissions
	 * that were NOT granted.  Therefore, if any of the
	 * wanted_dirperms WERE granted, we will have:
	 *   dzp_working_mode != wanted_dirperms
	 * We're really asking if ANY of those permissions
	 * were granted, and if so, grant delete access.
	 */
	if (dzp_working_mode != wanted_dirperms)
		dzp_error = 0;

	/*
	 * dzp_error is 0 if the container granted us permissions to "modify".
	 * If we do not have permission via one or more ACEs, our current
	 * privileges may still permit us to modify the container.
	 *
	 * dzpcheck_privs is false when i.e. the FS is read-only.
	 * Otherwise, do privilege checks for the container.
	 */
	if (dzp_error != 0 && dzpcheck_privs) {
		uid_t owner;

		/*
		 * The secpolicy call needs the requested access and
		 * the current access mode of the container, but it
		 * only knows about Unix-style modes (VEXEC, VWRITE),
		 * so this must condense the fine-grained ACE bits into
		 * Unix modes.
		 *
		 * The VEXEC flag is easy, because we know that has
		 * always been checked before we get here (during the
		 * lookup of the target vnode).  The container has not
		 * granted us permissions to "modify", so we do not set
		 * the VWRITE flag in the current access mode.
		 */
		owner = zfs_fuid_map_id(dzp->z_zfsvfs, dzp->z_uid, cr,
		    ZFS_OWNER);
		dzp_error = secpolicy_vnode_access2(cr, ZTOV(dzp),
		    owner, VEXEC, VWRITE|VEXEC);
	}
	if (dzp_error != 0) {
		/*
		 * Note: We may have dzp_error = -1 here (from
		 * zfs_zacess_common).  Don't return that.
		 */
		return (SET_ERROR(EACCES));
	}

	/*
	 * At this point, we know that the directory permissions allow
	 * us to modify, but we still need to check for the additional
	 * restrictions that apply when the "sticky bit" is set.
	 *
	 * Yes, zfs_sticky_remove_access() also checks this bit, but
	 * checking it here and skipping the call below is nice when
	 * you're watching all of this with dtrace.
	 */
	if ((dzp->z_mode & S_ISVTX) == 0)
		return (0);

	/*
	 * zfs_sticky_remove_access will succeed if:
	 * 1. The sticky bit is absent.
	 * 2. We pass the sticky bit restrictions.
	 * 3. We have privileges that always allow file removal.
	 */
	return (zfs_sticky_remove_access(dzp, zp, cr));
}

int
zfs_zaccess_rename(znode_t *sdzp, znode_t *szp, znode_t *tdzp,
    znode_t *tzp, cred_t *cr)
{
	int add_perm;
	int error;

	if (szp->z_pflags & ZFS_AV_QUARANTINED)
		return (SET_ERROR(EACCES));

	add_perm = (ZTOV(szp)->v_type == VDIR) ?
	    ACE_ADD_SUBDIRECTORY : ACE_ADD_FILE;

	/*
	 * Rename permissions are combination of delete permission +
	 * add file/subdir permission.
	 */

	/*
	 * first make sure we do the delete portion.
	 *
	 * If that succeeds then check for add_file/add_subdir permissions
	 */

	if (error = zfs_zaccess_delete(sdzp, szp, cr))
		return (error);

	/*
	 * If we have a tzp, see if we can delete it?
	 */
	if (tzp) {
		if (error = zfs_zaccess_delete(tdzp, tzp, cr))
			return (error);
	}

	/*
	 * Now check for add permissions
	 */
	error = zfs_zaccess(tdzp, add_perm, 0, B_FALSE, cr);

	return (error);
}