fs/zfs/zfs_acl.c

	zfs_acl.c revision 4929fd5ef3f018b490359eb4a2d95d22152325fb
/*
 * 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 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#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 "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
};

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));
}

static 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);
}

static 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;

    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, int 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 (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 (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.
 * Also, create FUIDs for any User/Group ACEs
 */
static uint64_t
zfs_mode_compute(znode_t *zp, zfs_acl_t *aclp)
{
    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 = (zp->z_phys->zp_mode & (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 owner@, group@ or everyone@ inherit only ACEs
         */
        if ((iflags & ACE_INHERIT_ONLY_ACE) &&
            (entry_type == ACE_OWNER || entry_type == ACE_EVERYONE ||
            entry_type == OWNING_GROUP))
            continue;

        if (entry_type == ACE_OWNER) {
            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) {
            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)
        zp->z_phys->zp_flags &= ~ZFS_NO_EXECS_DENIED;
    else
        zp->z_phys->zp_flags |= ZFS_NO_EXECS_DENIED;

    return (mode);
}

static zfs_acl_t *
zfs_acl_node_read_internal(znode_t *zp, boolean_t will_modify)
{
    zfs_acl_t   *aclp;
    zfs_acl_node_t  *aclnode;

    aclp = zfs_acl_alloc(zp->z_phys->zp_acl.z_acl_version);

    /*
     * Version 0 to 1 znode_acl_phys has the size/count fields swapped.
     * Version 0 didn't have a size field, only a count.
     */
    if (zp->z_phys->zp_acl.z_acl_version == ZFS_ACL_VERSION_INITIAL) {
        aclp->z_acl_count = zp->z_phys->zp_acl.z_acl_size;
        aclp->z_acl_bytes = ZFS_ACL_SIZE(aclp->z_acl_count);
    } else {
        aclp->z_acl_count = zp->z_phys->zp_acl.z_acl_count;
        aclp->z_acl_bytes = zp->z_phys->zp_acl.z_acl_size;
    }

    aclnode = zfs_acl_node_alloc(will_modify ? aclp->z_acl_bytes : 0);
    aclnode->z_ace_count = aclp->z_acl_count;
    if (will_modify) {
        bcopy(zp->z_phys->zp_acl.z_ace_data, aclnode->z_acldata,
            aclp->z_acl_bytes);
    } else {
        aclnode->z_size = aclp->z_acl_bytes;
        aclnode->z_acldata = &zp->z_phys->zp_acl.z_ace_data[0];
    }

    list_insert_head(&aclp->z_acl, aclnode);

    return (aclp);
}

/*
 * Read an external acl object.  If the intent is to modify, always
 * create a new acl and leave any cached acl in place.
 */
static int
zfs_acl_node_read(znode_t *zp, zfs_acl_t **aclpp, boolean_t will_modify)
{
    uint64_t extacl = zp->z_phys->zp_acl.z_acl_extern_obj;
    zfs_acl_t   *aclp;
    size_t      aclsize;
    size_t      acl_count;
    zfs_acl_node_t  *aclnode;
    int error;

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

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

    if (zp->z_phys->zp_acl.z_acl_extern_obj == 0) {
        *aclpp = zfs_acl_node_read_internal(zp, will_modify);
        if (!will_modify)
            zp->z_acl_cached = *aclpp;
        return (0);
    }

    aclp = zfs_acl_alloc(zp->z_phys->zp_acl.z_acl_version);
    if (zp->z_phys->zp_acl.z_acl_version == ZFS_ACL_VERSION_INITIAL) {
        zfs_acl_phys_v0_t *zacl0 =
            (zfs_acl_phys_v0_t *)&zp->z_phys->zp_acl;

        aclsize = ZFS_ACL_SIZE(zacl0->z_acl_count);
        acl_count = zacl0->z_acl_count;
    } else {
        aclsize = zp->z_phys->zp_acl.z_acl_size;
        acl_count = zp->z_phys->zp_acl.z_acl_count;
        if (aclsize == 0)
            aclsize = acl_count * sizeof (zfs_ace_t);
    }
    aclnode = zfs_acl_node_alloc(aclsize);
    list_insert_head(&aclp->z_acl, aclnode);
    error = dmu_read(zp->z_zfsvfs->z_os, extacl, 0,
        aclsize, aclnode->z_acldata, DMU_READ_PREFETCH);
    aclnode->z_ace_count = acl_count;
    aclp->z_acl_count = acl_count;
    aclp->z_acl_bytes = aclsize;

    if (error != 0) {
        zfs_acl_free(aclp);
        /* convert checksum errors into IO errors */
        if (error == ECKSUM)
            error = EIO;
        return (error);
    }

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

/*
 * 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;
    znode_phys_t    *zphys = zp->z_phys;
    zfs_acl_phys_t  *zacl = &zphys->zp_acl;
    zfsvfs_t    *zfsvfs = zp->z_zfsvfs;
    uint64_t    aoid = zphys->zp_acl.z_acl_extern_obj;
    uint64_t    off = 0;
    dmu_object_type_t otype;
    zfs_acl_node_t  *aclnode;

    dmu_buf_will_dirty(zp->z_dbuf, tx);

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

    zphys->zp_mode = zfs_mode_compute(zp, aclp);

    /*
     * Decide which object type to use.  If we are forced to
     * use old ACL format then transform ACL into zfs_oldace_t
     * layout.
     */
    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;
    }

    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 != zacl->z_acl_version) {
            error = dmu_object_free(zfsvfs->z_os,
                zp->z_phys->zp_acl.z_acl_extern_obj, 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_MAX_BONUSLEN : 0, tx);
        } else {
            (void) dmu_object_set_blocksize(zfsvfs->z_os, aoid,
                aclp->z_acl_bytes, 0, tx);
        }
        zphys->zp_acl.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 = zacl->z_ace_data;
        /*
         * Migrating back embedded?
         */
        if (zphys->zp_acl.z_acl_extern_obj) {
            error = dmu_object_free(zfsvfs->z_os,
                zp->z_phys->zp_acl.z_acl_extern_obj, tx);
            if (error)
                return (error);
            zphys->zp_acl.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) {
        zphys->zp_acl.z_acl_size = aclp->z_acl_count;
        zphys->zp_acl.z_acl_count = aclp->z_acl_bytes;
    } else {
        zphys->zp_acl.z_acl_size = aclp->z_acl_bytes;
        zphys->zp_acl.z_acl_count = aclp->z_acl_count;
    }

    zphys->zp_acl.z_acl_version = aclp->z_version;

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

    zp->z_phys->zp_flags |= aclp->z_hints;

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

    return (0);
}

/*
 * Update access mask for prepended ACE
 *
 * This applies the "groupmask" value for aclmode property.
 */
static void
zfs_acl_prepend_fixup(zfs_acl_t *aclp, void  *acep, void  *origacep,
    mode_t mode, uint64_t owner)
{
    int rmask, wmask, xmask;
    int user_ace;
    uint16_t aceflags;
    uint32_t origmask, acepmask;
    uint64_t fuid;

    aceflags = aclp->z_ops.ace_flags_get(acep);
    fuid = aclp->z_ops.ace_who_get(acep);
    origmask = aclp->z_ops.ace_mask_get(origacep);
    acepmask = aclp->z_ops.ace_mask_get(acep);

    user_ace = (!(aceflags &
        (ACE_OWNER|ACE_GROUP|ACE_IDENTIFIER_GROUP)));

    if (user_ace && (fuid == owner)) {
        rmask = S_IRUSR;
        wmask = S_IWUSR;
        xmask = S_IXUSR;
    } else {
        rmask = S_IRGRP;
        wmask = S_IWGRP;
        xmask = S_IXGRP;
    }

    if (origmask & ACE_READ_DATA) {
        if (mode & rmask) {
            acepmask &= ~ACE_READ_DATA;
        } else {
            acepmask |= ACE_READ_DATA;
        }
    }

    if (origmask & ACE_WRITE_DATA) {
        if (mode & wmask) {
            acepmask &= ~ACE_WRITE_DATA;
        } else {
            acepmask |= ACE_WRITE_DATA;
        }
    }

    if (origmask & ACE_APPEND_DATA) {
        if (mode & wmask) {
            acepmask &= ~ACE_APPEND_DATA;
        } else {
            acepmask |= ACE_APPEND_DATA;
        }
    }

    if (origmask & ACE_EXECUTE) {
        if (mode & xmask) {
            acepmask &= ~ACE_EXECUTE;
        } else {
            acepmask |= ACE_EXECUTE;
        }
    }
    aclp->z_ops.ace_mask_set(acep, acepmask);
}

/*
 * Apply mode to canonical six ACEs.
 */
static void
zfs_acl_fixup_canonical_six(zfs_acl_t *aclp, mode_t mode)
{
    zfs_acl_node_t *aclnode = list_tail(&aclp->z_acl);
    void    *acep;
    int maskoff = aclp->z_ops.ace_mask_off();
    size_t abstract_size = aclp->z_ops.ace_abstract_size();

    ASSERT(aclnode != NULL);

    acep = (void *)((caddr_t)aclnode->z_acldata +
        aclnode->z_size - (abstract_size * 6));

    /*
     * Fixup final ACEs to match the mode
     */

    adjust_ace_pair_common(acep, maskoff, abstract_size,
        (mode & 0700) >> 6);    /* owner@ */

    acep = (caddr_t)acep + (abstract_size * 2);

    adjust_ace_pair_common(acep, maskoff, abstract_size,
        (mode & 0070) >> 3);    /* group@ */

    acep = (caddr_t)acep + (abstract_size * 2);
    adjust_ace_pair_common(acep, maskoff,
        abstract_size, mode);   /* everyone@ */
}


static int
zfs_acl_ace_match(zfs_acl_t *aclp, void *acep, int allow_deny,
    int entry_type, int accessmask)
{
    uint32_t mask = aclp->z_ops.ace_mask_get(acep);
    uint16_t type = aclp->z_ops.ace_type_get(acep);
    uint16_t flags = aclp->z_ops.ace_flags_get(acep);

    return (mask == accessmask && type == allow_deny &&
        ((flags & ACE_TYPE_FLAGS) == entry_type));
}

/*
 * Can prepended ACE be reused?
 */
static int
zfs_reuse_deny(zfs_acl_t *aclp, void *acep, void *prevacep)
{
    int okay_masks;
    uint16_t prevtype;
    uint16_t prevflags;
    uint16_t flags;
    uint32_t mask, prevmask;

    if (prevacep == NULL)
        return (B_FALSE);

    prevtype = aclp->z_ops.ace_type_get(prevacep);
    prevflags = aclp->z_ops.ace_flags_get(prevacep);
    flags = aclp->z_ops.ace_flags_get(acep);
    mask = aclp->z_ops.ace_mask_get(acep);
    prevmask = aclp->z_ops.ace_mask_get(prevacep);

    if (prevtype != DENY)
        return (B_FALSE);

    if (prevflags != (flags & ACE_IDENTIFIER_GROUP))
        return (B_FALSE);

    okay_masks = (mask & OKAY_MASK_BITS);

    if (prevmask & ~okay_masks)
        return (B_FALSE);

    return (B_TRUE);
}


/*
 * Insert new ACL node into chain of zfs_acl_node_t's
 *
 * This will result in two possible results.
 * 1. If the ACL is currently just a single zfs_acl_node and
 *    we are prepending the entry then current acl node will have
 *    a new node inserted above it.
 *
 * 2. If we are inserting in the middle of current acl node then
 *    the current node will be split in two and new node will be inserted
 *    in between the two split nodes.
 */
static zfs_acl_node_t *
zfs_acl_ace_insert(zfs_acl_t *aclp, void  *acep)
{
    zfs_acl_node_t  *newnode;
    zfs_acl_node_t  *trailernode = NULL;
    zfs_acl_node_t  *currnode = zfs_acl_curr_node(aclp);
    int     curr_idx = aclp->z_curr_node->z_ace_idx;
    int     trailer_count;
    size_t      oldsize;

    newnode = zfs_acl_node_alloc(aclp->z_ops.ace_size(acep));
    newnode->z_ace_count = 1;

    oldsize = currnode->z_size;

    if (curr_idx != 1) {
        trailernode = zfs_acl_node_alloc(0);
        trailernode->z_acldata = acep;

        trailer_count = currnode->z_ace_count - curr_idx + 1;
        currnode->z_ace_count = curr_idx - 1;
        currnode->z_size = (caddr_t)acep - (caddr_t)currnode->z_acldata;
        trailernode->z_size = oldsize - currnode->z_size;
        trailernode->z_ace_count = trailer_count;
    }

    aclp->z_acl_count += 1;
    aclp->z_acl_bytes += aclp->z_ops.ace_size(acep);

    if (curr_idx == 1)
        list_insert_before(&aclp->z_acl, currnode, newnode);
    else
        list_insert_after(&aclp->z_acl, currnode, newnode);
    if (trailernode) {
        list_insert_after(&aclp->z_acl, newnode, trailernode);
        aclp->z_curr_node = trailernode;
        trailernode->z_ace_idx = 1;
    }

    return (newnode);
}

/*
 * Prepend deny ACE
 */
static void *
zfs_acl_prepend_deny(uint64_t uid, zfs_acl_t *aclp, void *acep,
    mode_t mode)
{
    zfs_acl_node_t *aclnode;
    void  *newacep;
    uint64_t fuid;
    uint16_t flags;

    aclnode = zfs_acl_ace_insert(aclp, acep);
    newacep = aclnode->z_acldata;
    fuid = aclp->z_ops.ace_who_get(acep);
    flags = aclp->z_ops.ace_flags_get(acep);
    zfs_set_ace(aclp, newacep, 0, DENY, fuid, (flags & ACE_TYPE_FLAGS));
    zfs_acl_prepend_fixup(aclp, newacep, acep, mode, uid);

    return (newacep);
}

/*
 * Split an inherited ACE into inherit_only ACE
 * and original ACE with inheritance flags stripped off.
 */
static void
zfs_acl_split_ace(zfs_acl_t *aclp, zfs_ace_hdr_t *acep)
{
    zfs_acl_node_t *aclnode;
    zfs_acl_node_t *currnode;
    void  *newacep;
    uint16_t type, flags;
    uint32_t mask;
    uint64_t fuid;

    type = aclp->z_ops.ace_type_get(acep);
    flags = aclp->z_ops.ace_flags_get(acep);
    mask = aclp->z_ops.ace_mask_get(acep);
    fuid = aclp->z_ops.ace_who_get(acep);

    aclnode = zfs_acl_ace_insert(aclp, acep);
    newacep = aclnode->z_acldata;

    aclp->z_ops.ace_type_set(newacep, type);
    aclp->z_ops.ace_flags_set(newacep, flags | ACE_INHERIT_ONLY_ACE);
    aclp->z_ops.ace_mask_set(newacep, mask);
    aclp->z_ops.ace_type_set(newacep, type);
    aclp->z_ops.ace_who_set(newacep, fuid);
    aclp->z_next_ace = acep;
    flags &= ~ALL_INHERIT;
    aclp->z_ops.ace_flags_set(acep, flags);
    currnode = zfs_acl_curr_node(aclp);
    ASSERT(currnode->z_ace_idx >= 1);
    currnode->z_ace_idx -= 1;
}

/*
 * Are ACES started at index i, the canonical six ACES?
 */
static int
zfs_have_canonical_six(zfs_acl_t *aclp)
{
    void *acep;
    zfs_acl_node_t *aclnode = list_tail(&aclp->z_acl);
    int     i = 0;
    size_t abstract_size = aclp->z_ops.ace_abstract_size();

    ASSERT(aclnode != NULL);

    if (aclnode->z_ace_count < 6)
        return (0);

    acep = (void *)((caddr_t)aclnode->z_acldata +
        aclnode->z_size - (aclp->z_ops.ace_abstract_size() * 6));

    if ((zfs_acl_ace_match(aclp, (caddr_t)acep + (abstract_size * i++),
        DENY, ACE_OWNER, 0) &&
        zfs_acl_ace_match(aclp, (caddr_t)acep + (abstract_size * i++),
        ALLOW, ACE_OWNER, OWNER_ALLOW_MASK) &&
        zfs_acl_ace_match(aclp, (caddr_t)acep + (abstract_size * i++), DENY,
        OWNING_GROUP, 0) && zfs_acl_ace_match(aclp, (caddr_t)acep +
        (abstract_size * i++),
        ALLOW, OWNING_GROUP, 0) &&
        zfs_acl_ace_match(aclp, (caddr_t)acep + (abstract_size * i++),
        DENY, ACE_EVERYONE, EVERYONE_DENY_MASK) &&
        zfs_acl_ace_match(aclp, (caddr_t)acep + (abstract_size * i++),
        ALLOW, ACE_EVERYONE, EVERYONE_ALLOW_MASK))) {
        return (1);
    } else {
        return (0);
    }
}


/*
 * Apply step 1g, to group entries
 *
 * Need to deal with corner case where group may have
 * greater permissions than owner.  If so then limit
 * group permissions, based on what extra permissions
 * group has.
 */
static void
zfs_fixup_group_entries(zfs_acl_t *aclp, void *acep, void *prevacep,
    mode_t mode)
{
    uint32_t prevmask = aclp->z_ops.ace_mask_get(prevacep);
    uint32_t mask = aclp->z_ops.ace_mask_get(acep);
    uint16_t prevflags = aclp->z_ops.ace_flags_get(prevacep);
    mode_t extramode = (mode >> 3) & 07;
    mode_t ownermode = (mode >> 6);

    if (prevflags & ACE_IDENTIFIER_GROUP) {

        extramode &= ~ownermode;

        if (extramode) {
            if (extramode & S_IROTH) {
                prevmask &= ~ACE_READ_DATA;
                mask &= ~ACE_READ_DATA;
            }
            if (extramode & S_IWOTH) {
                prevmask &= ~(ACE_WRITE_DATA|ACE_APPEND_DATA);
                mask &= ~(ACE_WRITE_DATA|ACE_APPEND_DATA);
            }
            if (extramode & S_IXOTH) {
                prevmask  &= ~ACE_EXECUTE;
                mask &= ~ACE_EXECUTE;
            }
        }
    }
    aclp->z_ops.ace_mask_set(acep, mask);
    aclp->z_ops.ace_mask_set(prevacep, prevmask);
}

/*
 * Apply the chmod algorithm as described
 * in PSARC/2002/240
 */
static void
zfs_acl_chmod(zfsvfs_t *zfsvfs, uint64_t uid,
    uint64_t mode, zfs_acl_t *aclp)
{
    void        *acep = NULL, *prevacep = NULL;
    uint64_t    who;
    int         i;
    int         entry_type;
    int         reuse_deny;
    int         need_canonical_six = 1;
    uint16_t    iflags, type;
    uint32_t    access_mask;

    /*
     * If discard then just discard all ACL nodes which
     * represent the ACEs.
     *
     * New owner@/group@/everone@ ACEs will be added
     * later.
     */
    if (zfsvfs->z_acl_mode == ZFS_ACL_DISCARD)
        zfs_acl_release_nodes(aclp);

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

        entry_type = (iflags & ACE_TYPE_FLAGS);
        iflags = (iflags & ALL_INHERIT);

        if ((type != ALLOW && type != DENY) ||
            (iflags & ACE_INHERIT_ONLY_ACE)) {
            if (iflags)
                aclp->z_hints |= ZFS_INHERIT_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;
            }
            goto nextace;
        }

        /*
         * Need to split ace into two?
         */
        if ((iflags & (ACE_FILE_INHERIT_ACE|
            ACE_DIRECTORY_INHERIT_ACE)) &&
            (!(iflags & ACE_INHERIT_ONLY_ACE))) {
            zfs_acl_split_ace(aclp, acep);
            aclp->z_hints |= ZFS_INHERIT_ACE;
            goto nextace;
        }

        if (entry_type == ACE_OWNER || entry_type == ACE_EVERYONE ||
            (entry_type == OWNING_GROUP)) {
            access_mask &= ~OGE_CLEAR;
            aclp->z_ops.ace_mask_set(acep, access_mask);
            goto nextace;
        } else {
            reuse_deny = B_TRUE;
            if (type == ALLOW) {

                /*
                 * Check preceding ACE if any, to see
                 * if we need to prepend a DENY ACE.
                 * This is only applicable when the acl_mode
                 * property == groupmask.
                 */
                if (zfsvfs->z_acl_mode == ZFS_ACL_GROUPMASK) {

                    reuse_deny = zfs_reuse_deny(aclp, acep,
                        prevacep);

                    if (!reuse_deny) {
                        prevacep =
                            zfs_acl_prepend_deny(uid,
                            aclp, acep, mode);
                    } else {
                        zfs_acl_prepend_fixup(
                            aclp, prevacep,
                            acep, mode, uid);
                    }
                    zfs_fixup_group_entries(aclp, acep,
                        prevacep, mode);
                }
            }
        }
nextace:
        prevacep = acep;
    }

    /*
     * Check out last six aces, if we have six.
     */

    if (aclp->z_acl_count >= 6) {
        if (zfs_have_canonical_six(aclp)) {
            need_canonical_six = 0;
        }
    }

    if (need_canonical_six) {
        size_t abstract_size = aclp->z_ops.ace_abstract_size();
        void *zacep;
        zfs_acl_node_t *aclnode =
            zfs_acl_node_alloc(abstract_size * 6);

        aclnode->z_size = abstract_size * 6;
        aclnode->z_ace_count = 6;
        aclp->z_acl_bytes += aclnode->z_size;
        list_insert_tail(&aclp->z_acl, aclnode);

        zacep = aclnode->z_acldata;

        i = 0;
        zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++),
            0, DENY, -1, ACE_OWNER);
        zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++),
            OWNER_ALLOW_MASK, ALLOW, -1, ACE_OWNER);
        zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++), 0,
            DENY, -1, OWNING_GROUP);
        zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++), 0,
            ALLOW, -1, OWNING_GROUP);
        zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++),
            EVERYONE_DENY_MASK, DENY, -1, ACE_EVERYONE);
        zfs_set_ace(aclp, (caddr_t)zacep + (abstract_size * i++),
            EVERYONE_ALLOW_MASK, ALLOW, -1, ACE_EVERYONE);
        aclp->z_acl_count += 6;
    }

    zfs_acl_fixup_canonical_six(aclp, mode);
}

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

    mutex_enter(&zp->z_lock);
    mutex_enter(&zp->z_acl_lock);
    *aclp = NULL;
    error = zfs_acl_node_read(zp, aclp, B_TRUE);
    if (error == 0) {
        (*aclp)->z_hints = zp->z_phys->zp_flags & V4_ACL_WIDE_FLAGS;
        zfs_acl_chmod(zp->z_zfsvfs, zp->z_phys->zp_uid, mode, *aclp);
    }
    mutex_exit(&zp->z_acl_lock);
    mutex_exit(&zp->z_lock);
    return (error);
}

/*
 * strip off write_owner and write_acl
 */
static void
zfs_restricted_update(zfsvfs_t *zfsvfs, zfs_acl_t *aclp, void *acep)
{
    uint32_t mask = aclp->z_ops.ace_mask_get(acep);

    if ((zfsvfs->z_acl_inherit == ZFS_ACL_RESTRICTED) &&
        (aclp->z_ops.ace_type_get(acep) == ALLOW)) {
        mask &= ~RESTRICTED_CLEAR;
        aclp->z_ops.ace_mask_set(acep, mask);
    }
}

/*
 * 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;
    void        *acep, *acep2;
    zfs_acl_node_t  *aclnode, *aclnode2;
    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;
    boolean_t   vdir = vtype == VDIR;
    boolean_t   vreg = vtype == VREG;
    boolean_t   passthrough, passthrough_x, noallow;

    passthrough_x =
        zfsvfs->z_acl_inherit == ZFS_ACL_PASSTHROUGH_X;
    passthrough = passthrough_x ||
        zfsvfs->z_acl_inherit == ZFS_ACL_PASSTHROUGH;
    noallow =
        zfsvfs->z_acl_inherit == ZFS_ACL_NOALLOW;

    *need_chmod = B_TRUE;
    pacep = NULL;
    aclp = zfs_acl_alloc(paclp->z_version);
    if (zfsvfs->z_acl_inherit == ZFS_ACL_DISCARD)
        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;

        if (noallow && type == ALLOW)
            continue;

        ace_size = aclp->z_ops.ace_size(pacep);

        if (!zfs_ace_can_use(vtype, iflags))
            continue;

        /*
         * If owner@, group@, or everyone@ inheritable
         * then zfs_acl_chmod() isn't needed.
         */
        if (passthrough &&
            ((iflags & (ACE_OWNER|ACE_EVERYONE)) ||
            ((iflags & OWNING_GROUP) ==
            OWNING_GROUP)) && (vreg || (vdir && (iflags &
            ACE_DIRECTORY_INHERIT_ACE)))) {
            *need_chmod = B_FALSE;

            if (!vdir && passthrough_x &&
                ((mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) {
                access_mask &= ~ACE_EXECUTE;
            }
        }

        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 (vdir)
            aclp->z_hints |= ZFS_INHERIT_ACE;

        if ((iflags & ACE_NO_PROPAGATE_INHERIT_ACE) || !vdir) {
            newflags &= ~ALL_INHERIT;
            aclp->z_ops.ace_flags_set(acep,
                newflags|ACE_INHERITED_ACE);
            zfs_restricted_update(zfsvfs, aclp, acep);
            continue;
        }

        ASSERT(vdir);

        newflags = aclp->z_ops.ace_flags_get(acep);
        if ((iflags & (ACE_FILE_INHERIT_ACE |
            ACE_DIRECTORY_INHERIT_ACE)) !=
            ACE_FILE_INHERIT_ACE) {
            aclnode2 = zfs_acl_node_alloc(ace_size);
            list_insert_tail(&aclp->z_acl, aclnode2);
            acep2 = aclnode2->z_acldata;
            zfs_set_ace(aclp, acep2,
                access_mask, type, who,
                iflags|ACE_INHERITED_ACE);
            newflags |= ACE_INHERIT_ONLY_ACE;
            aclp->z_ops.ace_flags_set(acep, newflags);
            newflags &= ~ALL_INHERIT;
            aclp->z_ops.ace_flags_set(acep2,
                newflags|ACE_INHERITED_ACE);

            /*
             * Copy special opaque data if any
             */
            if ((data1sz = aclp->z_ops.ace_data(acep,
                &data1)) != 0) {
                VERIFY((data2sz =
                    aclp->z_ops.ace_data(acep2,
                    &data2)) == data1sz);
                bcopy(data1, data2, data1sz);
            }
            aclp->z_acl_count++;
            aclnode2->z_ace_count++;
            aclp->z_acl_bytes += aclnode->z_size;
            zfs_restricted_update(zfsvfs, aclp, acep2);
        } 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.
 */
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;

    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 | IS_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_phys->zp_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_phys->zp_mode & S_ISGID) {
                acl_ids->z_fgid = dzp->z_phys->zp_gid;
                gid = zfs_fuid_map_id(zfsvfs, acl_ids->z_fgid,
                    cr, 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_phys->zp_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_lock);
        if (!(flag & IS_ROOT_NODE) && (ZTOV(dzp)->v_type == VDIR &&
            (dzp->z_phys->zp_flags & ZFS_INHERIT_ACE)) &&
            !(dzp->z_phys->zp_flags & ZFS_XATTR)) {
            mutex_enter(&dzp->z_acl_lock);
            VERIFY(0 == zfs_acl_node_read(dzp, &paclp, B_FALSE));
            mutex_exit(&dzp->z_acl_lock);
            acl_ids->z_aclp = zfs_acl_inherit(zfsvfs,
                vap->va_type, paclp, acl_ids->z_mode, &need_chmod);
        } else {
            acl_ids->z_aclp =
                zfs_acl_alloc(zfs_acl_version_zp(dzp));
        }
        mutex_exit(&dzp->z_lock);
        if (need_chmod) {
            acl_ids->z_aclp->z_hints = (vap->va_type == VDIR) ?
                ZFS_ACL_AUTO_INHERIT : 0;
            zfs_acl_chmod(zfsvfs, acl_ids->z_fuid,
                acl_ids->z_mode, acl_ids->z_aclp);
        }
    }

    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 *zfsvfs, zfs_acl_ids_t *acl_ids)
{
    return (zfs_usergroup_overquota(zfsvfs, B_FALSE, acl_ids->z_fuid) ||
        zfs_usergroup_overquota(zfsvfs, B_TRUE, acl_ids->z_fgid));
}

/*
 * Retrieve a files 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 (error = zfs_zaccess(zp, ACE_READ_ACL, 0, skipaclchk, cr))
        return (error);

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

    mutex_enter(&zp->z_acl_lock);

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

    /*
     * Scan ACL to determine number of ACEs
     */
    if ((zp->z_phys->zp_flags & 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 = aclp->z_acl_count;

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

    if (mask & VSA_ACE) {
        size_t aclsz;

        zfs_acl_node_t *aclnode = list_head(&aclp->z_acl);

        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 {
            bcopy(aclnode->z_acldata, vsecp->vsa_aclentp,
                count * sizeof (ace_t));
        }
    }
    if (mask & VSA_ACE_ACLFLAGS) {
        vsecp->vsa_aclflags = 0;
        if (zp->z_phys->zp_flags & ZFS_ACL_DEFAULTED)
            vsecp->vsa_aclflags |= ACL_DEFAULTED;
        if (zp->z_phys->zp_flags & ZFS_ACL_PROTECTED)
            vsecp->vsa_aclflags |= ACL_PROTECTED;
        if (zp->z_phys->zp_flags & 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 (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 files 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;

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

    if (zp->z_phys->zp_flags & ZFS_IMMUTABLE)
        return (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_phys->zp_flags & V4_ACL_WIDE_FLAGS);
    }
top:
    mutex_enter(&zp->z_lock);
    mutex_enter(&zp->z_acl_lock);

    tx = dmu_tx_create(zfsvfs->z_os);
    dmu_tx_hold_bonus(tx, zp->z_id);

    if (zp->z_phys->zp_acl.z_acl_extern_obj) {
        /* Are we upgrading ACL? */
        if (zfsvfs->z_version <= ZPL_VERSION_FUID &&
            zp->z_phys->zp_acl.z_acl_version ==
            ZFS_ACL_VERSION_INITIAL) {
            dmu_tx_hold_free(tx,
                zp->z_phys->zp_acl.z_acl_extern_obj,
                0, DMU_OBJECT_END);
            dmu_tx_hold_write(tx, DMU_NEW_OBJECT,
                0, aclp->z_acl_bytes);
        } else {
            dmu_tx_hold_write(tx,
                zp->z_phys->zp_acl.z_acl_extern_obj,
                0, aclp->z_acl_bytes);
        }
    } else if (aclp->z_acl_bytes > ZFS_ACE_SPACE) {
        dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0, aclp->z_acl_bytes);
    }
    fuid_dirtied = zfsvfs->z_fuid_dirty;
    if (fuid_dirtied)
        zfs_fuid_txhold(zfsvfs, tx);

    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);
    zp->z_acl_cached = aclp;

    if (fuid_dirtied)
        zfs_fuid_sync(zfsvfs, tx);

    zfs_time_stamper_locked(zp, STATE_CHANGED, 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_acl_lock);
    mutex_exit(&zp->z_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 (EROFS);
    }

    /*
     * Only check for READONLY on non-directories.
     */
    if ((v4_mode & WRITE_MASK_DATA) &&
        (((ZTOV(zp)->v_type != VDIR) &&
        (zp->z_phys->zp_flags & (ZFS_READONLY | ZFS_IMMUTABLE))) ||
        (ZTOV(zp)->v_type == VDIR &&
        (zp->z_phys->zp_flags & ZFS_IMMUTABLE)))) {
        return (EPERM);
    }

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

    if (((v4_mode & (ACE_READ_DATA|ACE_EXECUTE)) &&
        (zp->z_phys->zp_flags & ZFS_AV_QUARANTINED))) {
        return (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
 *  EACCESS     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;
    uid_t       uid = crgetuid(cr);
    uint64_t    who;
    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;
    uid_t       fowner;
    uid_t       gowner;

    zfs_fuid_map_ids(zp, cr, &fowner, &gowner);

    mutex_enter(&zp->z_acl_lock);

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

    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:
            if (uid == fowner)
                checkit = B_TRUE;
            break;
        case OWNING_GROUP:
            who = gowner;
            /*FALLTHROUGH*/
        case ACE_IDENTIFIER_GROUP:
            checkit = zfs_groupmember(zfsvfs, who, cr);
            break;
        case ACE_EVERYONE:
            checkit = B_TRUE;
            break;

        /* USER Entry */
        default:
            if (entry_type == 0) {
                uid_t newid;

                newid = zfs_fuid_map_id(zfsvfs, who, cr,
                    ZFS_ACE_USER);
                if (newid != IDMAP_WK_CREATOR_OWNER_UID &&
                    uid == newid)
                    checkit = B_TRUE;
                break;
            } else {
                mutex_exit(&zp->z_acl_lock);
                return (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 (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_phys->zp_uid, cr, ZFS_OWNER);

        return (
            secpolicy_vnode_access(cr, ZTOV(zp), owner, VREAD) == 0 ||
            secpolicy_vnode_access(cr, ZTOV(zp), owner, VWRITE) == 0 ||
            secpolicy_vnode_access(cr, ZTOV(zp), owner, VEXEC) == 0 ||
            secpolicy_vnode_chown(cr, owner) == 0 ||
            secpolicy_vnode_setdac(cr, owner) == 0 ||
            secpolicy_vnode_remove(cr) == 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);
    }

    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 (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 owner = B_FALSE;
    boolean_t groupmbr = B_FALSE;
    boolean_t is_attr;
    uid_t fowner;
    uid_t gowner;
    uid_t uid = crgetuid(cr);
    int error;

    if (zdp->z_phys->zp_flags & ZFS_AV_QUARANTINED)
        return (EACCES);

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

    mutex_enter(&zdp->z_acl_lock);

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

    if (FUID_INDEX(zdp->z_phys->zp_uid) != 0 ||
        FUID_INDEX(zdp->z_phys->zp_gid) != 0) {
        mutex_exit(&zdp->z_acl_lock);
        goto slow;
    }

    fowner = (uid_t)zdp->z_phys->zp_uid;
    gowner = (uid_t)zdp->z_phys->zp_gid;

    if (uid == fowner) {
        owner = B_TRUE;
        if (zdp->z_phys->zp_mode & S_IXUSR) {
            mutex_exit(&zdp->z_acl_lock);
            return (0);
        }
    }
    if (groupmember(gowner, cr)) {
        groupmbr = B_TRUE;
        if (zdp->z_phys->zp_mode & S_IXGRP) {
            mutex_exit(&zdp->z_acl_lock);
            return (0);
        }
    }
    if (!owner && !groupmbr) {
        if (zdp->z_phys->zp_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, B_FALSE, cr);
    ZFS_EXIT(zdp->z_zfsvfs);
    return (error);
}

/*
 * Determine whether Access should be granted/denied, invoking least
 * priv subsytem when a deny is determined.
 */
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;
    zfsvfs_t    *zfsvfs = zp->z_zfsvfs;
    boolean_t   check_privs;
    znode_t     *xzp;
    znode_t     *check_zp = zp;

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

    /*
     * If attribute then validate against base file
     */
    if (is_attr) {
        if ((error = zfs_zget(zp->z_zfsvfs,
            zp->z_phys->zp_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;
        }
    }

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

    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) {
        uid_t       owner;
        mode_t      checkmode = 0;

        owner = zfs_fuid_map_id(zfsvfs, check_zp->z_phys->zp_uid, cr,
            ZFS_OWNER);

        /*
         * 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;

        if (checkmode)
            error = secpolicy_vnode_access(cr, ZTOV(check_zp),
                owner, checkmode);

        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_setdac(cr, owner);

        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 = EACCES;
            }
        }
    }

    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));
}

static int
zfs_delete_final_check(znode_t *zp, znode_t *dzp,
    mode_t missing_perms, cred_t *cr)
{
    int error;
    uid_t downer;
    zfsvfs_t *zfsvfs = zp->z_zfsvfs;

    downer = zfs_fuid_map_id(zfsvfs, dzp->z_phys->zp_uid, cr, ZFS_OWNER);

    error = secpolicy_vnode_access(cr, ZTOV(dzp), downer, missing_perms);

    if (error == 0)
        error = zfs_sticky_remove_access(dzp, zp, cr);

    return (error);
}

/*
 * Determine whether Access should be granted/deny, without
 * consulting least priv subsystem.
 *
 *
 * The following chart is the recommended NFSv4 enforcement for
 * ability to delete an object.
 *
 *      -------------------------------------------------------
 *      |   Parent Dir  |           Target Object Permissions |
 *      |  permissions  |                                     |
 *      -------------------------------------------------------
 *      |               | ACL Allows | ACL Denies| Delete     |
 *      |               |  Delete    |  Delete   | unspecified|
 *      -------------------------------------------------------
 *      |  ACL Allows   | Permit     | Permit    | Permit     |
 *      |  DELETE_CHILD |                                     |
 *      -------------------------------------------------------
 *      |  ACL Denies   | Permit     | Deny      | Deny       |
 *      |  DELETE_CHILD |            |           |            |
 *      -------------------------------------------------------
 *      | ACL specifies |            |           |            |
 *      | only allow    | Permit     | Permit    | Permit     |
 *      | write and     |            |           |            |
 *      | execute       |            |           |            |
 *      -------------------------------------------------------
 *      | ACL denies    |            |           |            |
 *      | write and     | Permit     | Deny      | Deny       |
 *      | execute       |            |           |            |
 *      -------------------------------------------------------
 *         ^
 *         |
 *         No search privilege, can't even look up file?
 *
 */
int
zfs_zaccess_delete(znode_t *dzp, znode_t *zp, cred_t *cr)
{
    uint32_t dzp_working_mode = 0;
    uint32_t zp_working_mode = 0;
    int dzp_error, zp_error;
    mode_t missing_perms;
    boolean_t dzpcheck_privs = B_TRUE;
    boolean_t zpcheck_privs = B_TRUE;

    /*
     * We want specific DELETE permissions to
     * take precedence over WRITE/EXECUTE.  We don't
     * want an ACL such as this to mess us up.
     * user:joe:write_data:deny,user:joe:delete:allow
     *
     * However, deny permissions may ultimately be overridden
     * by secpolicy_vnode_access().
     *
     * We will ask for all of the necessary permissions and then
     * look at the working modes from the directory and target object
     * to determine what was found.
     */

    if (zp->z_phys->zp_flags & (ZFS_IMMUTABLE | ZFS_NOUNLINK))
        return (EPERM);

    /*
     * First row
     * If the directory permissions allow the delete, we are done.
     */
    if ((dzp_error = zfs_zaccess_common(dzp, ACE_DELETE_CHILD,
        &dzp_working_mode, &dzpcheck_privs, B_FALSE, cr)) == 0)
        return (0);

    /*
     * If target object has delete permission then we are done
     */
    if ((zp_error = zfs_zaccess_common(zp, ACE_DELETE, &zp_working_mode,
        &zpcheck_privs, B_FALSE, cr)) == 0)
        return (0);

    ASSERT(dzp_error && zp_error);

    if (!dzpcheck_privs)
        return (dzp_error);
    if (!zpcheck_privs)
        return (zp_error);

    /*
     * Second row
     *
     * If directory returns EACCES then delete_child was denied
     * due to deny delete_child.  In this case send the request through
     * secpolicy_vnode_remove().  We don't use zfs_delete_final_check()
     * since that *could* allow the delete based on write/execute permission
     * and we want delete permissions to override write/execute.
     */

    if (dzp_error == EACCES)
        return (secpolicy_vnode_remove(cr));

    /*
     * Third Row
     * only need to see if we have write/execute on directory.
     */

    if ((dzp_error = zfs_zaccess_common(dzp, ACE_EXECUTE|ACE_WRITE_DATA,
        &dzp_working_mode, &dzpcheck_privs, B_FALSE, cr)) == 0)
        return (zfs_sticky_remove_access(dzp, zp, cr));

    if (!dzpcheck_privs)
        return (dzp_error);

    /*
     * Fourth row
     */

    missing_perms = (dzp_working_mode & ACE_WRITE_DATA) ? VWRITE : 0;
    missing_perms |= (dzp_working_mode & ACE_EXECUTE) ? VEXEC : 0;

    ASSERT(missing_perms);

    return (zfs_delete_final_check(zp, dzp, missing_perms, 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_phys->zp_flags & ZFS_AV_QUARANTINED)
        return (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);
}