/*
 * 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) 2012, 2018 by Delphix. All rights reserved.
 * Copyright (c) 2014 Integros [integros.com]
 */

/* Portions Copyright 2007 Jeremy Teo */

#ifdef _KERNEL
#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/mntent.h>
#include <sys/mkdev.h>
#include <sys/u8_textprep.h>
#include <sys/dsl_dataset.h>
#include <sys/vfs.h>
#include <sys/vfs_opreg.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/kmem.h>
#include <sys/errno.h>
#include <sys/unistd.h>
#include <sys/mode.h>
#include <sys/atomic.h>
#include <vm/pvn.h>
#include "fs/fs_subr.h"
#include <sys/zfs_dir.h>
#include <sys/zfs_acl.h>
#include <sys/zfs_ioctl.h>
#include <sys/zfs_rlock.h>
#include <sys/zfs_fuid.h>
#include <sys/dnode.h>
#include <sys/fs/zfs.h>
#include <sys/kidmap.h>
#endif /* _KERNEL */

#include <sys/dmu.h>
#include <sys/dmu_objset.h>
#include <sys/dmu_tx.h>
#include <sys/refcount.h>
#include <sys/stat.h>
#include <sys/zap.h>
#include <sys/zfs_znode.h>
#include <sys/sa.h>
#include <sys/zfs_sa.h>
#include <sys/zfs_stat.h>

#include "zfs_prop.h"
#include "zfs_comutil.h"

/*
 * Define ZNODE_STATS to turn on statistic gathering. By default, it is only
 * turned on when DEBUG is also defined.
 */
#ifdef  DEBUG
#define ZNODE_STATS
#endif  /* DEBUG */

#ifdef  ZNODE_STATS
#define ZNODE_STAT_ADD(stat)                    ((stat)++)
#else
#define ZNODE_STAT_ADD(stat)                    /* nothing */
#endif  /* ZNODE_STATS */

/*
 * Functions needed for userland (ie: libzpool) are not put under
 * #ifdef_KERNEL; the rest of the functions have dependencies
 * (such as VFS logic) that will not compile easily in userland.
 */
#ifdef _KERNEL
/*
 * Needed to close a small window in zfs_znode_move() that allows the zfsvfs to
 * be freed before it can be safely accessed.
 */
krwlock_t zfsvfs_lock;

static kmem_cache_t *znode_cache = NULL;

/*
 * This is used by the test suite so that it can delay znodes from being
 * freed in order to inspect the unlinked set.
 */
int zfs_unlink_suspend_progress = 0;

/*ARGSUSED*/
static void
znode_evict_error(dmu_buf_t *dbuf, void *user_ptr)
{
        /*
         * We should never drop all dbuf refs without first clearing
         * the eviction callback.
         */
        panic("evicting znode %p\n", user_ptr);
}

/*
 * This callback is invoked when acquiring a RL_WRITER or RL_APPEND lock on
 * z_rangelock. It will modify the offset and length of the lock to reflect
 * znode-specific information, and convert RL_APPEND to RL_WRITER.  This is
 * called with the rangelock_t's rl_lock held, which avoids races.
 */
static void
zfs_rangelock_cb(locked_range_t *new, void *arg)
{
        znode_t *zp = arg;

        /*
         * If in append mode, convert to writer and lock starting at the
         * current end of file.
         */
        if (new->lr_type == RL_APPEND) {
                new->lr_offset = zp->z_size;
                new->lr_type = RL_WRITER;
        }

        /*
         * If we need to grow the block size then lock the whole file range.
         */
        uint64_t end_size = MAX(zp->z_size, new->lr_offset + new->lr_length);
        if (end_size > zp->z_blksz && (!ISP2(zp->z_blksz) ||
            zp->z_blksz < zp->z_zfsvfs->z_max_blksz)) {
                new->lr_offset = 0;
                new->lr_length = UINT64_MAX;
        }
}

/*ARGSUSED*/
static int
zfs_znode_cache_constructor(void *buf, void *arg, int kmflags)
{
        znode_t *zp = buf;

        ASSERT(!POINTER_IS_VALID(zp->z_zfsvfs));

        zp->z_vnode = vn_alloc(kmflags);
        if (zp->z_vnode == NULL) {
                return (-1);
        }
        ZTOV(zp)->v_data = zp;

        list_link_init(&zp->z_link_node);

        mutex_init(&zp->z_lock, NULL, MUTEX_DEFAULT, NULL);
        rw_init(&zp->z_parent_lock, NULL, RW_DEFAULT, NULL);
        rw_init(&zp->z_name_lock, NULL, RW_DEFAULT, NULL);
        rw_init(&zp->z_acl_lock, NULL, RW_DEFAULT, NULL);

        rangelock_init(&zp->z_rangelock, zfs_rangelock_cb, zp);

        zp->z_dirlocks = NULL;
        zp->z_acl_cached = NULL;
        zp->z_moved = 0;
        return (0);
}

/*ARGSUSED*/
static void
zfs_znode_cache_destructor(void *buf, void *arg)
{
        znode_t *zp = buf;

        ASSERT(!POINTER_IS_VALID(zp->z_zfsvfs));
        ASSERT(ZTOV(zp)->v_data == zp);
        vn_free(ZTOV(zp));
        ASSERT(!list_link_active(&zp->z_link_node));
        mutex_destroy(&zp->z_lock);
        rw_destroy(&zp->z_parent_lock);
        rw_destroy(&zp->z_name_lock);
        rw_destroy(&zp->z_acl_lock);
        rangelock_fini(&zp->z_rangelock);

        ASSERT(zp->z_dirlocks == NULL);
        ASSERT(zp->z_acl_cached == NULL);
}

#ifdef  ZNODE_STATS
static struct {
        uint64_t zms_zfsvfs_invalid;
        uint64_t zms_zfsvfs_recheck1;
        uint64_t zms_zfsvfs_unmounted;
        uint64_t zms_zfsvfs_recheck2;
        uint64_t zms_obj_held;
        uint64_t zms_vnode_locked;
        uint64_t zms_not_only_dnlc;
} znode_move_stats;
#endif  /* ZNODE_STATS */

static void
zfs_znode_move_impl(znode_t *ozp, znode_t *nzp)
{
        vnode_t *vp;

        /* Copy fields. */
        nzp->z_zfsvfs = ozp->z_zfsvfs;

        /* Swap vnodes. */
        vp = nzp->z_vnode;
        nzp->z_vnode = ozp->z_vnode;
        ozp->z_vnode = vp; /* let destructor free the overwritten vnode */
        ZTOV(ozp)->v_data = ozp;
        ZTOV(nzp)->v_data = nzp;

        nzp->z_id = ozp->z_id;
        ASSERT(ozp->z_dirlocks == NULL); /* znode not in use */
        nzp->z_unlinked = ozp->z_unlinked;
        nzp->z_atime_dirty = ozp->z_atime_dirty;
        nzp->z_zn_prefetch = ozp->z_zn_prefetch;
        nzp->z_blksz = ozp->z_blksz;
        nzp->z_seq = ozp->z_seq;
        nzp->z_mapcnt = ozp->z_mapcnt;
        nzp->z_gen = ozp->z_gen;
        nzp->z_sync_cnt = ozp->z_sync_cnt;
        nzp->z_is_sa = ozp->z_is_sa;
        nzp->z_sa_hdl = ozp->z_sa_hdl;
        bcopy(ozp->z_atime, nzp->z_atime, sizeof (uint64_t) * 2);
        nzp->z_links = ozp->z_links;
        nzp->z_size = ozp->z_size;
        nzp->z_pflags = ozp->z_pflags;
        nzp->z_uid = ozp->z_uid;
        nzp->z_gid = ozp->z_gid;
        nzp->z_mode = ozp->z_mode;

        /*
         * Since this is just an idle znode and kmem is already dealing with
         * memory pressure, release any cached ACL.
         */
        if (ozp->z_acl_cached) {
                zfs_acl_free(ozp->z_acl_cached);
                ozp->z_acl_cached = NULL;
        }

        sa_set_userp(nzp->z_sa_hdl, nzp);

        /*
         * Invalidate the original znode by clearing fields that provide a
         * pointer back to the znode. Set the low bit of the vfs pointer to
         * ensure that zfs_znode_move() recognizes the znode as invalid in any
         * subsequent callback.
         */
        ozp->z_sa_hdl = NULL;
        POINTER_INVALIDATE(&ozp->z_zfsvfs);

        /*
         * Mark the znode.
         */
        nzp->z_moved = 1;
        ozp->z_moved = (uint8_t)-1;
}

/*ARGSUSED*/
static kmem_cbrc_t
zfs_znode_move(void *buf, void *newbuf, size_t size, void *arg)
{
        znode_t *ozp = buf, *nzp = newbuf;
        zfsvfs_t *zfsvfs;
        vnode_t *vp;

        /*
         * The znode is on the file system's list of known znodes if the vfs
         * pointer is valid. We set the low bit of the vfs pointer when freeing
         * the znode to invalidate it, and the memory patterns written by kmem
         * (baddcafe and deadbeef) set at least one of the two low bits. A newly
         * created znode sets the vfs pointer last of all to indicate that the
         * znode is known and in a valid state to be moved by this function.
         */
        zfsvfs = ozp->z_zfsvfs;
        if (!POINTER_IS_VALID(zfsvfs)) {
                ZNODE_STAT_ADD(znode_move_stats.zms_zfsvfs_invalid);
                return (KMEM_CBRC_DONT_KNOW);
        }

        /*
         * Close a small window in which it's possible that the filesystem could
         * be unmounted and freed, and zfsvfs, though valid in the previous
         * statement, could point to unrelated memory by the time we try to
         * prevent the filesystem from being unmounted.
         */
        rw_enter(&zfsvfs_lock, RW_WRITER);
        if (zfsvfs != ozp->z_zfsvfs) {
                rw_exit(&zfsvfs_lock);
                ZNODE_STAT_ADD(znode_move_stats.zms_zfsvfs_recheck1);
                return (KMEM_CBRC_DONT_KNOW);
        }

        /*
         * If the znode is still valid, then so is the file system. We know that
         * no valid file system can be freed while we hold zfsvfs_lock, so we
         * can safely ensure that the filesystem is not and will not be
         * unmounted. The next statement is equivalent to ZFS_ENTER().
         */
        rrm_enter(&zfsvfs->z_teardown_lock, RW_READER, FTAG);
        if (zfsvfs->z_unmounted) {
                ZFS_EXIT(zfsvfs);
                rw_exit(&zfsvfs_lock);
                ZNODE_STAT_ADD(znode_move_stats.zms_zfsvfs_unmounted);
                return (KMEM_CBRC_DONT_KNOW);
        }
        rw_exit(&zfsvfs_lock);

        mutex_enter(&zfsvfs->z_znodes_lock);
        /*
         * Recheck the vfs pointer in case the znode was removed just before
         * acquiring the lock.
         */
        if (zfsvfs != ozp->z_zfsvfs) {
                mutex_exit(&zfsvfs->z_znodes_lock);
                ZFS_EXIT(zfsvfs);
                ZNODE_STAT_ADD(znode_move_stats.zms_zfsvfs_recheck2);
                return (KMEM_CBRC_DONT_KNOW);
        }

        /*
         * At this point we know that as long as we hold z_znodes_lock, the
         * znode cannot be freed and fields within the znode can be safely
         * accessed. Now, prevent a race with zfs_zget().
         */
        if (ZFS_OBJ_HOLD_TRYENTER(zfsvfs, ozp->z_id) == 0) {
                mutex_exit(&zfsvfs->z_znodes_lock);
                ZFS_EXIT(zfsvfs);
                ZNODE_STAT_ADD(znode_move_stats.zms_obj_held);
                return (KMEM_CBRC_LATER);
        }

        vp = ZTOV(ozp);
        if (mutex_tryenter(&vp->v_lock) == 0) {
                ZFS_OBJ_HOLD_EXIT(zfsvfs, ozp->z_id);
                mutex_exit(&zfsvfs->z_znodes_lock);
                ZFS_EXIT(zfsvfs);
                ZNODE_STAT_ADD(znode_move_stats.zms_vnode_locked);
                return (KMEM_CBRC_LATER);
        }

        /* Only move znodes that are referenced _only_ by the DNLC. */
        if (vp->v_count != 1 || !vn_in_dnlc(vp)) {
                mutex_exit(&vp->v_lock);
                ZFS_OBJ_HOLD_EXIT(zfsvfs, ozp->z_id);
                mutex_exit(&zfsvfs->z_znodes_lock);
                ZFS_EXIT(zfsvfs);
                ZNODE_STAT_ADD(znode_move_stats.zms_not_only_dnlc);
                return (KMEM_CBRC_LATER);
        }

        /*
         * The znode is known and in a valid state to move. We're holding the
         * locks needed to execute the critical section.
         */
        zfs_znode_move_impl(ozp, nzp);
        mutex_exit(&vp->v_lock);
        ZFS_OBJ_HOLD_EXIT(zfsvfs, ozp->z_id);

        list_link_replace(&ozp->z_link_node, &nzp->z_link_node);
        mutex_exit(&zfsvfs->z_znodes_lock);
        ZFS_EXIT(zfsvfs);

        return (KMEM_CBRC_YES);
}

void
zfs_znode_init(void)
{
        /*
         * Initialize zcache
         */
        rw_init(&zfsvfs_lock, NULL, RW_DEFAULT, NULL);
        ASSERT(znode_cache == NULL);
        znode_cache = kmem_cache_create("zfs_znode_cache",
            sizeof (znode_t), 0, zfs_znode_cache_constructor,
            zfs_znode_cache_destructor, NULL, NULL, NULL, 0);
        kmem_cache_set_move(znode_cache, zfs_znode_move);
}

void
zfs_znode_fini(void)
{
        /*
         * Cleanup vfs & vnode ops
         */
        zfs_remove_op_tables();

        /*
         * Cleanup zcache
         */
        if (znode_cache)
                kmem_cache_destroy(znode_cache);
        znode_cache = NULL;
        rw_destroy(&zfsvfs_lock);
}

struct vnodeops *zfs_dvnodeops;
struct vnodeops *zfs_fvnodeops;
struct vnodeops *zfs_symvnodeops;
struct vnodeops *zfs_xdvnodeops;
struct vnodeops *zfs_evnodeops;
struct vnodeops *zfs_sharevnodeops;

void
zfs_remove_op_tables()
{
        /*
         * Remove vfs ops
         */
        ASSERT(zfsfstype);
        (void) vfs_freevfsops_by_type(zfsfstype);
        zfsfstype = 0;

        /*
         * Remove vnode ops
         */
        if (zfs_dvnodeops)
                vn_freevnodeops(zfs_dvnodeops);
        if (zfs_fvnodeops)
                vn_freevnodeops(zfs_fvnodeops);
        if (zfs_symvnodeops)
                vn_freevnodeops(zfs_symvnodeops);
        if (zfs_xdvnodeops)
                vn_freevnodeops(zfs_xdvnodeops);
        if (zfs_evnodeops)
                vn_freevnodeops(zfs_evnodeops);
        if (zfs_sharevnodeops)
                vn_freevnodeops(zfs_sharevnodeops);

        zfs_dvnodeops = NULL;
        zfs_fvnodeops = NULL;
        zfs_symvnodeops = NULL;
        zfs_xdvnodeops = NULL;
        zfs_evnodeops = NULL;
        zfs_sharevnodeops = NULL;
}

extern const fs_operation_def_t zfs_dvnodeops_template[];
extern const fs_operation_def_t zfs_fvnodeops_template[];
extern const fs_operation_def_t zfs_xdvnodeops_template[];
extern const fs_operation_def_t zfs_symvnodeops_template[];
extern const fs_operation_def_t zfs_evnodeops_template[];
extern const fs_operation_def_t zfs_sharevnodeops_template[];

int
zfs_create_op_tables()
{
        int error;

        /*
         * zfs_dvnodeops can be set if mod_remove() calls mod_installfs()
         * due to a failure to remove the the 2nd modlinkage (zfs_modldrv).
         * In this case we just return as the ops vectors are already set up.
         */
        if (zfs_dvnodeops)
                return (0);

        error = vn_make_ops(MNTTYPE_ZFS, zfs_dvnodeops_template,
            &zfs_dvnodeops);
        if (error)
                return (error);

        error = vn_make_ops(MNTTYPE_ZFS, zfs_fvnodeops_template,
            &zfs_fvnodeops);
        if (error)
                return (error);

        error = vn_make_ops(MNTTYPE_ZFS, zfs_symvnodeops_template,
            &zfs_symvnodeops);
        if (error)
                return (error);

        error = vn_make_ops(MNTTYPE_ZFS, zfs_xdvnodeops_template,
            &zfs_xdvnodeops);
        if (error)
                return (error);

        error = vn_make_ops(MNTTYPE_ZFS, zfs_evnodeops_template,
            &zfs_evnodeops);
        if (error)
                return (error);

        error = vn_make_ops(MNTTYPE_ZFS, zfs_sharevnodeops_template,
            &zfs_sharevnodeops);

        return (error);
}

int
zfs_create_share_dir(zfsvfs_t *zfsvfs, dmu_tx_t *tx)
{
        zfs_acl_ids_t acl_ids;
        vattr_t vattr;
        znode_t *sharezp;
        vnode_t *vp;
        znode_t *zp;
        int error;

        vattr.va_mask = AT_MODE|AT_UID|AT_GID|AT_TYPE;
        vattr.va_type = VDIR;
        vattr.va_mode = S_IFDIR|0555;
        vattr.va_uid = crgetuid(kcred);
        vattr.va_gid = crgetgid(kcred);

        sharezp = kmem_cache_alloc(znode_cache, KM_SLEEP);
        ASSERT(!POINTER_IS_VALID(sharezp->z_zfsvfs));
        sharezp->z_moved = 0;
        sharezp->z_unlinked = 0;
        sharezp->z_atime_dirty = 0;
        sharezp->z_zfsvfs = zfsvfs;
        sharezp->z_is_sa = zfsvfs->z_use_sa;
        sharezp->z_pflags = 0;

        vp = ZTOV(sharezp);
        vn_reinit(vp);
        vp->v_type = VDIR;

        VERIFY(0 == zfs_acl_ids_create(sharezp, IS_ROOT_NODE, &vattr,
            kcred, NULL, &acl_ids));
        zfs_mknode(sharezp, &vattr, tx, kcred, IS_ROOT_NODE, &zp, &acl_ids);
        ASSERT3P(zp, ==, sharezp);
        ASSERT(!vn_in_dnlc(ZTOV(sharezp))); /* not valid to move */
        POINTER_INVALIDATE(&sharezp->z_zfsvfs);
        error = zap_add(zfsvfs->z_os, MASTER_NODE_OBJ,
            ZFS_SHARES_DIR, 8, 1, &sharezp->z_id, tx);
        zfsvfs->z_shares_dir = sharezp->z_id;

        zfs_acl_ids_free(&acl_ids);
        ZTOV(sharezp)->v_count = 0;
        sa_handle_destroy(sharezp->z_sa_hdl);
        kmem_cache_free(znode_cache, sharezp);

        return (error);
}

/*
 * define a couple of values we need available
 * for both 64 and 32 bit environments.
 */
#ifndef NBITSMINOR64
#define NBITSMINOR64    32
#endif
#ifndef MAXMAJ64
#define MAXMAJ64        0xffffffffUL
#endif
#ifndef MAXMIN64
#define MAXMIN64        0xffffffffUL
#endif

/*
 * Create special expldev for ZFS private use.
 * Can't use standard expldev since it doesn't do
 * what we want.  The standard expldev() takes a
 * dev32_t in LP64 and expands it to a long dev_t.
 * We need an interface that takes a dev32_t in ILP32
 * and expands it to a long dev_t.
 */
static uint64_t
zfs_expldev(dev_t dev)
{
#ifndef _LP64
        major_t major = (major_t)dev >> NBITSMINOR32 & MAXMAJ32;
        return (((uint64_t)major << NBITSMINOR64) |
            ((minor_t)dev & MAXMIN32));
#else
        return (dev);
#endif
}

/*
 * Special cmpldev for ZFS private use.
 * Can't use standard cmpldev since it takes
 * a long dev_t and compresses it to dev32_t in
 * LP64.  We need to do a compaction of a long dev_t
 * to a dev32_t in ILP32.
 */
dev_t
zfs_cmpldev(uint64_t dev)
{
#ifndef _LP64
        minor_t minor = (minor_t)dev & MAXMIN64;
        major_t major = (major_t)(dev >> NBITSMINOR64) & MAXMAJ64;

        if (major > MAXMAJ32 || minor > MAXMIN32)
                return (NODEV32);

        return (((dev32_t)major << NBITSMINOR32) | minor);
#else
        return (dev);
#endif
}

static void
zfs_znode_sa_init(zfsvfs_t *zfsvfs, znode_t *zp,
    dmu_buf_t *db, dmu_object_type_t obj_type, sa_handle_t *sa_hdl)
{
        ASSERT(!POINTER_IS_VALID(zp->z_zfsvfs) || (zfsvfs == zp->z_zfsvfs));
        ASSERT(MUTEX_HELD(ZFS_OBJ_MUTEX(zfsvfs, zp->z_id)));

        mutex_enter(&zp->z_lock);

        ASSERT(zp->z_sa_hdl == NULL);
        ASSERT(zp->z_acl_cached == NULL);
        if (sa_hdl == NULL) {
                VERIFY(0 == sa_handle_get_from_db(zfsvfs->z_os, db, zp,
                    SA_HDL_SHARED, &zp->z_sa_hdl));
        } else {
                zp->z_sa_hdl = sa_hdl;
                sa_set_userp(sa_hdl, zp);
        }

        zp->z_is_sa = (obj_type == DMU_OT_SA) ? B_TRUE : B_FALSE;

        /*
         * Slap on VROOT if we are the root znode
         */
        if (zp->z_id == zfsvfs->z_root)
                ZTOV(zp)->v_flag |= VROOT;

        mutex_exit(&zp->z_lock);
        vn_exists(ZTOV(zp));
}

void
zfs_znode_dmu_fini(znode_t *zp)
{
        ASSERT(MUTEX_HELD(ZFS_OBJ_MUTEX(zp->z_zfsvfs, zp->z_id)) ||
            zp->z_unlinked ||
            RW_WRITE_HELD(&zp->z_zfsvfs->z_teardown_inactive_lock));

        sa_handle_destroy(zp->z_sa_hdl);
        zp->z_sa_hdl = NULL;
}

/*
 * Construct a new znode/vnode and intialize.
 *
 * This does not do a call to dmu_set_user() that is
 * up to the caller to do, in case you don't want to
 * return the znode
 */
static znode_t *
zfs_znode_alloc(zfsvfs_t *zfsvfs, dmu_buf_t *db, int blksz,
    dmu_object_type_t obj_type, sa_handle_t *hdl)
{
        znode_t *zp;
        vnode_t *vp;
        uint64_t mode;
        uint64_t parent;
        uint64_t projid = ZFS_DEFAULT_PROJID;
        sa_bulk_attr_t bulk[11];
        int count = 0;

        zp = kmem_cache_alloc(znode_cache, KM_SLEEP);

        ASSERT(zp->z_dirlocks == NULL);
        ASSERT(!POINTER_IS_VALID(zp->z_zfsvfs));
        zp->z_moved = 0;

        /*
         * Defer setting z_zfsvfs until the znode is ready to be a candidate for
         * the zfs_znode_move() callback.
         */
        zp->z_sa_hdl = NULL;
        zp->z_unlinked = 0;
        zp->z_atime_dirty = 0;
        zp->z_mapcnt = 0;
        zp->z_id = db->db_object;
        zp->z_blksz = blksz;
        zp->z_seq = 0x7A4653;
        zp->z_sync_cnt = 0;

        vp = ZTOV(zp);
        vn_reinit(vp);

        zfs_znode_sa_init(zfsvfs, zp, db, obj_type, hdl);

        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MODE(zfsvfs), NULL, &mode, 8);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_GEN(zfsvfs), NULL, &zp->z_gen, 8);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
            &zp->z_size, 8);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
            &zp->z_links, 8);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs), NULL,
            &zp->z_pflags, 8);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_PARENT(zfsvfs), NULL, &parent, 8);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_ATIME(zfsvfs), NULL,
            &zp->z_atime, 16);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_UID(zfsvfs), NULL,
            &zp->z_uid, 8);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_GID(zfsvfs), NULL,
            &zp->z_gid, 8);

        if (sa_bulk_lookup(zp->z_sa_hdl, bulk, count) != 0 || zp->z_gen == 0 ||
            (dmu_objset_projectquota_enabled(zfsvfs->z_os) &&
            (zp->z_pflags & ZFS_PROJID) &&
            sa_lookup(zp->z_sa_hdl, SA_ZPL_PROJID(zfsvfs), &projid, 8) != 0)) {
                if (hdl == NULL)
                        sa_handle_destroy(zp->z_sa_hdl);
                kmem_cache_free(znode_cache, zp);
                return (NULL);
        }

        zp->z_projid = projid;
        zp->z_mode = mode;
        vp->v_vfsp = zfsvfs->z_parent->z_vfs;

        vp->v_type = IFTOVT((mode_t)mode);

        switch (vp->v_type) {
        case VDIR:
                if (zp->z_pflags & ZFS_XATTR) {
                        vn_setops(vp, zfs_xdvnodeops);
                        vp->v_flag |= V_XATTRDIR;
                } else {
                        vn_setops(vp, zfs_dvnodeops);
                }
                zp->z_zn_prefetch = B_TRUE; /* z_prefetch default is enabled */
                break;
        case VBLK:
        case VCHR:
                {
                        uint64_t rdev;
                        VERIFY(sa_lookup(zp->z_sa_hdl, SA_ZPL_RDEV(zfsvfs),
                            &rdev, sizeof (rdev)) == 0);

                        vp->v_rdev = zfs_cmpldev(rdev);
                }
                /*FALLTHROUGH*/
        case VFIFO:
        case VSOCK:
        case VDOOR:
                vn_setops(vp, zfs_fvnodeops);
                break;
        case VREG:
                vp->v_flag |= VMODSORT;
                if (parent == zfsvfs->z_shares_dir) {
                        ASSERT(zp->z_uid == 0 && zp->z_gid == 0);
                        vn_setops(vp, zfs_sharevnodeops);
                } else {
                        vn_setops(vp, zfs_fvnodeops);
                }
                break;
        case VLNK:
                vn_setops(vp, zfs_symvnodeops);
                break;
        default:
                vn_setops(vp, zfs_evnodeops);
                break;
        }

        mutex_enter(&zfsvfs->z_znodes_lock);
        list_insert_tail(&zfsvfs->z_all_znodes, zp);
        membar_producer();
        /*
         * Everything else must be valid before assigning z_zfsvfs makes the
         * znode eligible for zfs_znode_move().
         */
        zp->z_zfsvfs = zfsvfs;
        mutex_exit(&zfsvfs->z_znodes_lock);

        VFS_HOLD(zfsvfs->z_vfs);
        return (zp);
}

static uint64_t empty_xattr;
static uint64_t pad[4];
static zfs_acl_phys_t acl_phys;
/*
 * Create a new DMU object to hold a zfs znode.
 *
 *      IN:     dzp     - parent directory for new znode
 *              vap     - file attributes for new znode
 *              tx      - dmu transaction id for zap operations
 *              cr      - credentials of caller
 *              flag    - flags:
 *                        IS_ROOT_NODE  - new object will be root
 *                        IS_XATTR      - new object is an attribute
 *              bonuslen - length of bonus buffer
 *              setaclp  - File/Dir initial ACL
 *              fuidp    - Tracks fuid allocation.
 *
 *      OUT:    zpp     - allocated znode
 *
 */
void
zfs_mknode(znode_t *dzp, vattr_t *vap, dmu_tx_t *tx, cred_t *cr,
    uint_t flag, znode_t **zpp, zfs_acl_ids_t *acl_ids)
{
        uint64_t        crtime[2], atime[2], mtime[2], ctime[2];
        uint64_t        mode, size, links, parent, pflags;
        uint64_t        dzp_pflags = 0;
        uint64_t        projid = ZFS_DEFAULT_PROJID;
        uint64_t        rdev = 0;
        zfsvfs_t        *zfsvfs = dzp->z_zfsvfs;
        dmu_buf_t       *db;
        timestruc_t     now;
        uint64_t        gen, obj;
        int             bonuslen;
        int             dnodesize;
        sa_handle_t     *sa_hdl;
        dmu_object_type_t obj_type;
        sa_bulk_attr_t  *sa_attrs;
        int             cnt = 0;
        zfs_acl_locator_cb_t locate = { 0 };

        ASSERT(vap && (vap->va_mask & (AT_TYPE|AT_MODE)) == (AT_TYPE|AT_MODE));

        if (zfsvfs->z_replay) {
                obj = vap->va_nodeid;
                now = vap->va_ctime;            /* see zfs_replay_create() */
                gen = vap->va_nblocks;          /* ditto */
                dnodesize = vap->va_fsid;       /* ditto */
        } else {
                obj = 0;
                gethrestime(&now);
                gen = dmu_tx_get_txg(tx);
                dnodesize = dmu_objset_dnodesize(zfsvfs->z_os);
        }

        if (dnodesize == 0)
                dnodesize = DNODE_MIN_SIZE;

        obj_type = zfsvfs->z_use_sa ? DMU_OT_SA : DMU_OT_ZNODE;
        bonuslen = (obj_type == DMU_OT_SA) ?
            DN_BONUS_SIZE(dnodesize) : ZFS_OLD_ZNODE_PHYS_SIZE;

        /*
         * Create a new DMU object.
         */
        /*
         * There's currently no mechanism for pre-reading the blocks that will
         * be needed to allocate a new object, so we accept the small chance
         * that there will be an i/o error and we will fail one of the
         * assertions below.
         */
        if (vap->va_type == VDIR) {
                if (zfsvfs->z_replay) {
                        VERIFY0(zap_create_claim_norm_dnsize(zfsvfs->z_os, obj,
                            zfsvfs->z_norm, DMU_OT_DIRECTORY_CONTENTS,
                            obj_type, bonuslen, dnodesize, tx));
                } else {
                        obj = zap_create_norm_dnsize(zfsvfs->z_os,
                            zfsvfs->z_norm, DMU_OT_DIRECTORY_CONTENTS,
                            obj_type, bonuslen, dnodesize, tx);
                }
        } else {
                if (zfsvfs->z_replay) {
                        VERIFY0(dmu_object_claim_dnsize(zfsvfs->z_os, obj,
                            DMU_OT_PLAIN_FILE_CONTENTS, 0,
                            obj_type, bonuslen, dnodesize, tx));
                } else {
                        obj = dmu_object_alloc_dnsize(zfsvfs->z_os,
                            DMU_OT_PLAIN_FILE_CONTENTS, 0,
                            obj_type, bonuslen, dnodesize, tx);
                }
        }

        ZFS_OBJ_HOLD_ENTER(zfsvfs, obj);
        VERIFY0(sa_buf_hold(zfsvfs->z_os, obj, NULL, &db));

        /*
         * If this is the root, fix up the half-initialized parent pointer
         * to reference the just-allocated physical data area.
         */
        if (flag & IS_ROOT_NODE) {
                dzp->z_id = obj;
        }

        /*
         * If parent is an xattr, so am I.
         */
        if (dzp->z_pflags & ZFS_XATTR) {
                flag |= IS_XATTR;
        }

        if (zfsvfs->z_use_fuids)
                pflags = ZFS_ARCHIVE | ZFS_AV_MODIFIED;
        else
                pflags = 0;

        if (vap->va_type == VDIR) {
                size = 2;               /* contents ("." and "..") */
                links = (flag & (IS_ROOT_NODE | IS_XATTR)) ? 2 : 1;
        } else {
                size = links = 0;
        }

        if (vap->va_type == VBLK || vap->va_type == VCHR) {
                rdev = zfs_expldev(vap->va_rdev);
        }

        parent = dzp->z_id;
        mode = acl_ids->z_mode;
        if (flag & IS_XATTR)
                pflags |= ZFS_XATTR;

        if (vap->va_type == VREG || vap->va_type == VDIR) {
                /*
                 * With ZFS_PROJID flag, we can easily know whether there is
                 * project ID stored on disk or not. See zfs_space_delta_cb().
                 */
                if (obj_type != DMU_OT_ZNODE &&
                    dmu_objset_projectquota_enabled(zfsvfs->z_os))
                        pflags |= ZFS_PROJID;

                /*
                 * Inherit project ID from parent if required.
                 */
                projid = zfs_inherit_projid(dzp);
                if (dzp->z_pflags & ZFS_PROJINHERIT)
                        pflags |= ZFS_PROJINHERIT;
        }

        /*
         * No execs denied will be deterimed when zfs_mode_compute() is called.
         */
        pflags |= acl_ids->z_aclp->z_hints &
            (ZFS_ACL_TRIVIAL|ZFS_INHERIT_ACE|ZFS_ACL_AUTO_INHERIT|
            ZFS_ACL_DEFAULTED|ZFS_ACL_PROTECTED);

        ZFS_TIME_ENCODE(&now, crtime);
        ZFS_TIME_ENCODE(&now, ctime);

        if (vap->va_mask & AT_ATIME) {
                ZFS_TIME_ENCODE(&vap->va_atime, atime);
        } else {
                ZFS_TIME_ENCODE(&now, atime);
        }

        if (vap->va_mask & AT_MTIME) {
                ZFS_TIME_ENCODE(&vap->va_mtime, mtime);
        } else {
                ZFS_TIME_ENCODE(&now, mtime);
        }

        /* Now add in all of the "SA" attributes */
        VERIFY(0 == sa_handle_get_from_db(zfsvfs->z_os, db, NULL, SA_HDL_SHARED,
            &sa_hdl));

        /*
         * Setup the array of attributes to be replaced/set on the new file
         *
         * order for  DMU_OT_ZNODE is critical since it needs to be constructed
         * in the old znode_phys_t format.  Don't change this ordering
         */
        sa_attrs = kmem_alloc(sizeof (sa_bulk_attr_t) * ZPL_END, KM_SLEEP);

        if (obj_type == DMU_OT_ZNODE) {
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_ATIME(zfsvfs),
                    NULL, &atime, 16);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_MTIME(zfsvfs),
                    NULL, &mtime, 16);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_CTIME(zfsvfs),
                    NULL, &ctime, 16);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_CRTIME(zfsvfs),
                    NULL, &crtime, 16);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_GEN(zfsvfs),
                    NULL, &gen, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_MODE(zfsvfs),
                    NULL, &mode, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_SIZE(zfsvfs),
                    NULL, &size, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_PARENT(zfsvfs),
                    NULL, &parent, 8);
        } else {
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_MODE(zfsvfs),
                    NULL, &mode, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_SIZE(zfsvfs),
                    NULL, &size, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_GEN(zfsvfs),
                    NULL, &gen, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_UID(zfsvfs),
                    NULL, &acl_ids->z_fuid, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_GID(zfsvfs),
                    NULL, &acl_ids->z_fgid, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_PARENT(zfsvfs),
                    NULL, &parent, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_FLAGS(zfsvfs),
                    NULL, &pflags, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_ATIME(zfsvfs),
                    NULL, &atime, 16);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_MTIME(zfsvfs),
                    NULL, &mtime, 16);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_CTIME(zfsvfs),
                    NULL, &ctime, 16);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_CRTIME(zfsvfs),
                    NULL, &crtime, 16);
        }

        SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_LINKS(zfsvfs), NULL, &links, 8);

        if (obj_type == DMU_OT_ZNODE) {
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_XATTR(zfsvfs), NULL,
                    &empty_xattr, 8);
        } else if (dmu_objset_projectquota_enabled(zfsvfs->z_os) &&
            pflags & ZFS_PROJID) {
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_PROJID(zfsvfs),
                    NULL, &projid, 8);
        }
        if (obj_type == DMU_OT_ZNODE ||
            (vap->va_type == VBLK || vap->va_type == VCHR)) {
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_RDEV(zfsvfs),
                    NULL, &rdev, 8);

        }
        if (obj_type == DMU_OT_ZNODE) {
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_FLAGS(zfsvfs),
                    NULL, &pflags, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_UID(zfsvfs), NULL,
                    &acl_ids->z_fuid, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_GID(zfsvfs), NULL,
                    &acl_ids->z_fgid, 8);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_PAD(zfsvfs), NULL, pad,
                    sizeof (uint64_t) * 4);
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_ZNODE_ACL(zfsvfs), NULL,
                    &acl_phys, sizeof (zfs_acl_phys_t));
        } else if (acl_ids->z_aclp->z_version >= ZFS_ACL_VERSION_FUID) {
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_DACL_COUNT(zfsvfs), NULL,
                    &acl_ids->z_aclp->z_acl_count, 8);
                locate.cb_aclp = acl_ids->z_aclp;
                SA_ADD_BULK_ATTR(sa_attrs, cnt, SA_ZPL_DACL_ACES(zfsvfs),
                    zfs_acl_data_locator, &locate,
                    acl_ids->z_aclp->z_acl_bytes);
                mode = zfs_mode_compute(mode, acl_ids->z_aclp, &pflags,
                    acl_ids->z_fuid, acl_ids->z_fgid);
        }

        VERIFY(sa_replace_all_by_template(sa_hdl, sa_attrs, cnt, tx) == 0);

        if (!(flag & IS_ROOT_NODE)) {
                *zpp = zfs_znode_alloc(zfsvfs, db, 0, obj_type, sa_hdl);
                ASSERT(*zpp != NULL);
        } else {
                /*
                 * If we are creating the root node, the "parent" we
                 * passed in is the znode for the root.
                 */
                *zpp = dzp;

                (*zpp)->z_sa_hdl = sa_hdl;
        }

        (*zpp)->z_pflags = pflags;
        (*zpp)->z_mode = mode;
        (*zpp)->z_dnodesize = dnodesize;
        (*zpp)->z_projid = projid;

        if (vap->va_mask & AT_XVATTR)
                zfs_xvattr_set(*zpp, (xvattr_t *)vap, tx);

        if (obj_type == DMU_OT_ZNODE ||
            acl_ids->z_aclp->z_version < ZFS_ACL_VERSION_FUID) {
                VERIFY0(zfs_aclset_common(*zpp, acl_ids->z_aclp, cr, tx));
        }
        kmem_free(sa_attrs, sizeof (sa_bulk_attr_t) * ZPL_END);
        ZFS_OBJ_HOLD_EXIT(zfsvfs, obj);
}

/*
 * Update in-core attributes.  It is assumed the caller will be doing an
 * sa_bulk_update to push the changes out.
 */
void
zfs_xvattr_set(znode_t *zp, xvattr_t *xvap, dmu_tx_t *tx)
{
        xoptattr_t *xoap;

        xoap = xva_getxoptattr(xvap);
        ASSERT(xoap);

        if (XVA_ISSET_REQ(xvap, XAT_CREATETIME)) {
                uint64_t times[2];
                ZFS_TIME_ENCODE(&xoap->xoa_createtime, times);
                (void) sa_update(zp->z_sa_hdl, SA_ZPL_CRTIME(zp->z_zfsvfs),
                    &times, sizeof (times), tx);
                XVA_SET_RTN(xvap, XAT_CREATETIME);
        }
        if (XVA_ISSET_REQ(xvap, XAT_READONLY)) {
                ZFS_ATTR_SET(zp, ZFS_READONLY, xoap->xoa_readonly,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_READONLY);
        }
        if (XVA_ISSET_REQ(xvap, XAT_HIDDEN)) {
                ZFS_ATTR_SET(zp, ZFS_HIDDEN, xoap->xoa_hidden,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_HIDDEN);
        }
        if (XVA_ISSET_REQ(xvap, XAT_SYSTEM)) {
                ZFS_ATTR_SET(zp, ZFS_SYSTEM, xoap->xoa_system,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_SYSTEM);
        }
        if (XVA_ISSET_REQ(xvap, XAT_ARCHIVE)) {
                ZFS_ATTR_SET(zp, ZFS_ARCHIVE, xoap->xoa_archive,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_ARCHIVE);
        }
        if (XVA_ISSET_REQ(xvap, XAT_IMMUTABLE)) {
                ZFS_ATTR_SET(zp, ZFS_IMMUTABLE, xoap->xoa_immutable,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_IMMUTABLE);
        }
        if (XVA_ISSET_REQ(xvap, XAT_NOUNLINK)) {
                ZFS_ATTR_SET(zp, ZFS_NOUNLINK, xoap->xoa_nounlink,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_NOUNLINK);
        }
        if (XVA_ISSET_REQ(xvap, XAT_APPENDONLY)) {
                ZFS_ATTR_SET(zp, ZFS_APPENDONLY, xoap->xoa_appendonly,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_APPENDONLY);
        }
        if (XVA_ISSET_REQ(xvap, XAT_NODUMP)) {
                ZFS_ATTR_SET(zp, ZFS_NODUMP, xoap->xoa_nodump,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_NODUMP);
        }
        if (XVA_ISSET_REQ(xvap, XAT_OPAQUE)) {
                ZFS_ATTR_SET(zp, ZFS_OPAQUE, xoap->xoa_opaque,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_OPAQUE);
        }
        if (XVA_ISSET_REQ(xvap, XAT_AV_QUARANTINED)) {
                ZFS_ATTR_SET(zp, ZFS_AV_QUARANTINED,
                    xoap->xoa_av_quarantined, zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_AV_QUARANTINED);
        }
        if (XVA_ISSET_REQ(xvap, XAT_AV_MODIFIED)) {
                ZFS_ATTR_SET(zp, ZFS_AV_MODIFIED, xoap->xoa_av_modified,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_AV_MODIFIED);
        }
        if (XVA_ISSET_REQ(xvap, XAT_AV_SCANSTAMP)) {
                zfs_sa_set_scanstamp(zp, xvap, tx);
                XVA_SET_RTN(xvap, XAT_AV_SCANSTAMP);
        }
        if (XVA_ISSET_REQ(xvap, XAT_REPARSE)) {
                ZFS_ATTR_SET(zp, ZFS_REPARSE, xoap->xoa_reparse,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_REPARSE);
        }
        if (XVA_ISSET_REQ(xvap, XAT_OFFLINE)) {
                ZFS_ATTR_SET(zp, ZFS_OFFLINE, xoap->xoa_offline,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_OFFLINE);
        }
        if (XVA_ISSET_REQ(xvap, XAT_SPARSE)) {
                ZFS_ATTR_SET(zp, ZFS_SPARSE, xoap->xoa_sparse,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_SPARSE);
        }
        if (XVA_ISSET_REQ(xvap, XAT_PROJINHERIT)) {
                ZFS_ATTR_SET(zp, ZFS_PROJINHERIT, xoap->xoa_projinherit,
                    zp->z_pflags, tx);
                XVA_SET_RTN(xvap, XAT_PROJINHERIT);
        }
}

int
zfs_zget(zfsvfs_t *zfsvfs, uint64_t obj_num, znode_t **zpp)
{
        dmu_object_info_t doi;
        dmu_buf_t       *db;
        znode_t         *zp;
        int err;
        sa_handle_t     *hdl;

        *zpp = NULL;

        ZFS_OBJ_HOLD_ENTER(zfsvfs, obj_num);

        err = sa_buf_hold(zfsvfs->z_os, obj_num, NULL, &db);
        if (err) {
                ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
                return (err);
        }

        dmu_object_info_from_db(db, &doi);
        if (doi.doi_bonus_type != DMU_OT_SA &&
            (doi.doi_bonus_type != DMU_OT_ZNODE ||
            (doi.doi_bonus_type == DMU_OT_ZNODE &&
            doi.doi_bonus_size < sizeof (znode_phys_t)))) {
                sa_buf_rele(db, NULL);
                ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
                return (SET_ERROR(EINVAL));
        }

        hdl = dmu_buf_get_user(db);
        if (hdl != NULL) {
                zp  = sa_get_userdata(hdl);


                /*
                 * Since "SA" does immediate eviction we
                 * should never find a sa handle that doesn't
                 * know about the znode.
                 */

                ASSERT3P(zp, !=, NULL);

                mutex_enter(&zp->z_lock);
                ASSERT3U(zp->z_id, ==, obj_num);
                if (zp->z_unlinked) {
                        err = SET_ERROR(ENOENT);
                } else {
                        VN_HOLD(ZTOV(zp));
                        *zpp = zp;
                        err = 0;
                }
                mutex_exit(&zp->z_lock);
                sa_buf_rele(db, NULL);
                ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
                return (err);
        }

        /*
         * Not found create new znode/vnode
         * but only if file exists.
         *
         * There is a small window where zfs_vget() could
         * find this object while a file create is still in
         * progress.  This is checked for in zfs_znode_alloc()
         *
         * if zfs_znode_alloc() fails it will drop the hold on the
         * bonus buffer.
         */
        zp = zfs_znode_alloc(zfsvfs, db, doi.doi_data_block_size,
            doi.doi_bonus_type, NULL);
        if (zp == NULL) {
                err = SET_ERROR(ENOENT);
        } else {
                if (zp->z_links == 0)
                        zp->z_unlinked = B_TRUE;
                *zpp = zp;
        }
        ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
        return (err);
}

int
zfs_rezget(znode_t *zp)
{
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        dmu_object_info_t doi;
        dmu_buf_t *db;
        uint64_t obj_num = zp->z_id;
        uint64_t mode;
        sa_bulk_attr_t bulk[10];
        int err;
        int count = 0;
        uint64_t gen;
        uint64_t projid = ZFS_DEFAULT_PROJID;

        ZFS_OBJ_HOLD_ENTER(zfsvfs, obj_num);

        rw_enter(&zp->z_acl_lock, RW_WRITER);
        if (zp->z_acl_cached) {
                zfs_acl_free(zp->z_acl_cached);
                zp->z_acl_cached = NULL;
        }
        rw_exit(&zp->z_acl_lock);

        ASSERT(zp->z_sa_hdl == NULL);
        err = sa_buf_hold(zfsvfs->z_os, obj_num, NULL, &db);
        if (err) {
                ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
                return (err);
        }

        dmu_object_info_from_db(db, &doi);
        if (doi.doi_bonus_type != DMU_OT_SA &&
            (doi.doi_bonus_type != DMU_OT_ZNODE ||
            (doi.doi_bonus_type == DMU_OT_ZNODE &&
            doi.doi_bonus_size < sizeof (znode_phys_t)))) {
                sa_buf_rele(db, NULL);
                ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
                return (SET_ERROR(EINVAL));
        }

        zfs_znode_sa_init(zfsvfs, zp, db, doi.doi_bonus_type, NULL);

        /* reload cached values */
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_GEN(zfsvfs), NULL,
            &gen, sizeof (gen));
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs), NULL,
            &zp->z_size, sizeof (zp->z_size));
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_LINKS(zfsvfs), NULL,
            &zp->z_links, sizeof (zp->z_links));
        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_ATIME(zfsvfs), NULL,
            &zp->z_atime, sizeof (zp->z_atime));
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_UID(zfsvfs), NULL,
            &zp->z_uid, sizeof (zp->z_uid));
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_GID(zfsvfs), NULL,
            &zp->z_gid, sizeof (zp->z_gid));
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MODE(zfsvfs), NULL,
            &mode, sizeof (mode));

        if (sa_bulk_lookup(zp->z_sa_hdl, bulk, count)) {
                zfs_znode_dmu_fini(zp);
                ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
                return (SET_ERROR(EIO));
        }

        if (dmu_objset_projectquota_enabled(zfsvfs->z_os)) {
                err = sa_lookup(zp->z_sa_hdl, SA_ZPL_PROJID(zfsvfs),
                    &projid, 8);
                if (err != 0 && err != ENOENT) {
                        zfs_znode_dmu_fini(zp);
                        ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
                        return (SET_ERROR(err));
                }
        }

        zp->z_projid = projid;
        zp->z_mode = mode;

        if (gen != zp->z_gen) {
                zfs_znode_dmu_fini(zp);
                ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);
                return (SET_ERROR(EIO));
        }

        zp->z_blksz = doi.doi_data_block_size;

        /*
         * If the file has zero links, then it has been unlinked on the send
         * side and it must be in the received unlinked set.
         * We call zfs_znode_dmu_fini() now to prevent any accesses to the
         * stale data and to prevent automatical removal of the file in
         * zfs_zinactive().  The file will be removed either when it is removed
         * on the send side and the next incremental stream is received or
         * when the unlinked set gets processed.
         */
        zp->z_unlinked = (zp->z_links == 0);
        if (zp->z_unlinked)
                zfs_znode_dmu_fini(zp);

        ZFS_OBJ_HOLD_EXIT(zfsvfs, obj_num);

        return (0);
}

void
zfs_znode_delete(znode_t *zp, dmu_tx_t *tx)
{
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        objset_t *os = zfsvfs->z_os;
        uint64_t obj = zp->z_id;
        uint64_t acl_obj = zfs_external_acl(zp);

        ZFS_OBJ_HOLD_ENTER(zfsvfs, obj);
        if (acl_obj) {
                VERIFY(!zp->z_is_sa);
                VERIFY(0 == dmu_object_free(os, acl_obj, tx));
        }
        VERIFY(0 == dmu_object_free(os, obj, tx));
        zfs_znode_dmu_fini(zp);
        ZFS_OBJ_HOLD_EXIT(zfsvfs, obj);
        zfs_znode_free(zp);
}

void
zfs_zinactive(znode_t *zp)
{
        vnode_t *vp = ZTOV(zp);
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        uint64_t z_id = zp->z_id;

        ASSERT(zp->z_sa_hdl);

        /*
         * Don't allow a zfs_zget() while were trying to release this znode
         */
        ZFS_OBJ_HOLD_ENTER(zfsvfs, z_id);

        mutex_enter(&zp->z_lock);
        mutex_enter(&vp->v_lock);
        VN_RELE_LOCKED(vp);
        if (vp->v_count > 0 || vn_has_cached_data(vp)) {
                /*
                 * If the hold count is greater than zero, somebody has
                 * obtained a new reference on this znode while we were
                 * processing it here, so we are done.  If we still have
                 * mapped pages then we are also done, since we don't
                 * want to inactivate the znode until the pages get pushed.
                 *
                 * XXX - if vn_has_cached_data(vp) is true, but count == 0,
                 * this seems like it would leave the znode hanging with
                 * no chance to go inactive...
                 */
                mutex_exit(&vp->v_lock);
                mutex_exit(&zp->z_lock);
                ZFS_OBJ_HOLD_EXIT(zfsvfs, z_id);
                return;
        }
        mutex_exit(&vp->v_lock);

        /*
         * If this was the last reference to a file with no links, remove
         * the file from the file system unless the file system is mounted
         * read-only.  That can happen, for example, if the file system was
         * originally read-write, the file was opened, then unlinked and
         * the file system was made read-only before the file was finally
         * closed.  The file will remain in the unlinked set.
         */
        if (zp->z_unlinked) {
                ASSERT(!zfsvfs->z_issnap);
                if ((zfsvfs->z_vfs->vfs_flag & VFS_RDONLY) == 0 &&
                    !zfs_unlink_suspend_progress) {
                        mutex_exit(&zp->z_lock);
                        ZFS_OBJ_HOLD_EXIT(zfsvfs, z_id);
                        zfs_rmnode(zp);
                        return;
                }
        }

        mutex_exit(&zp->z_lock);
        zfs_znode_dmu_fini(zp);
        ZFS_OBJ_HOLD_EXIT(zfsvfs, z_id);
        zfs_znode_free(zp);
}

void
zfs_znode_free(znode_t *zp)
{
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;

        vn_invalid(ZTOV(zp));

        ASSERT(ZTOV(zp)->v_count == 0);

        mutex_enter(&zfsvfs->z_znodes_lock);
        POINTER_INVALIDATE(&zp->z_zfsvfs);
        list_remove(&zfsvfs->z_all_znodes, zp);
        mutex_exit(&zfsvfs->z_znodes_lock);

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

        kmem_cache_free(znode_cache, zp);

        VFS_RELE(zfsvfs->z_vfs);
}

void
zfs_tstamp_update_setup(znode_t *zp, uint_t flag, uint64_t mtime[2],
    uint64_t ctime[2], boolean_t have_tx)
{
        timestruc_t     now;

        gethrestime(&now);

        if (have_tx) {  /* will sa_bulk_update happen really soon? */
                zp->z_atime_dirty = 0;
                zp->z_seq++;
        } else {
                zp->z_atime_dirty = 1;
        }

        if (flag & AT_ATIME) {
                ZFS_TIME_ENCODE(&now, zp->z_atime);
        }

        if (flag & AT_MTIME) {
                ZFS_TIME_ENCODE(&now, mtime);
                if (zp->z_zfsvfs->z_use_fuids) {
                        zp->z_pflags |= (ZFS_ARCHIVE |
                            ZFS_AV_MODIFIED);
                }
        }

        if (flag & AT_CTIME) {
                ZFS_TIME_ENCODE(&now, ctime);
                if (zp->z_zfsvfs->z_use_fuids)
                        zp->z_pflags |= ZFS_ARCHIVE;
        }
}

/*
 * Grow the block size for a file.
 *
 *      IN:     zp      - znode of file to free data in.
 *              size    - requested block size
 *              tx      - open transaction.
 *
 * NOTE: this function assumes that the znode is write locked.
 */
void
zfs_grow_blocksize(znode_t *zp, uint64_t size, dmu_tx_t *tx)
{
        int             error;
        u_longlong_t    dummy;

        if (size <= zp->z_blksz)
                return;
        /*
         * If the file size is already greater than the current blocksize,
         * we will not grow.  If there is more than one block in a file,
         * the blocksize cannot change.
         */
        if (zp->z_blksz && zp->z_size > zp->z_blksz)
                return;

        error = dmu_object_set_blocksize(zp->z_zfsvfs->z_os, zp->z_id,
            size, 0, tx);

        if (error == ENOTSUP)
                return;
        ASSERT0(error);

        /* What blocksize did we actually get? */
        dmu_object_size_from_db(sa_get_db(zp->z_sa_hdl), &zp->z_blksz, &dummy);
}

/*
 * This is a dummy interface used when pvn_vplist_dirty() should *not*
 * be calling back into the fs for a putpage().  E.g.: when truncating
 * a file, the pages being "thrown away* don't need to be written out.
 */
/* ARGSUSED */
static int
zfs_no_putpage(vnode_t *vp, page_t *pp, u_offset_t *offp, size_t *lenp,
    int flags, cred_t *cr)
{
        ASSERT(0);
        return (0);
}

/*
 * Increase the file length
 *
 *      IN:     zp      - znode of file to free data in.
 *              end     - new end-of-file
 *
 *      RETURN: 0 on success, error code on failure
 */
static int
zfs_extend(znode_t *zp, uint64_t end)
{
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        dmu_tx_t *tx;
        locked_range_t *lr;
        uint64_t newblksz;
        int error;

        /*
         * We will change zp_size, lock the whole file.
         */
        lr = rangelock_enter(&zp->z_rangelock, 0, UINT64_MAX, RL_WRITER);

        /*
         * Nothing to do if file already at desired length.
         */
        if (end <= zp->z_size) {
                rangelock_exit(lr);
                return (0);
        }
        tx = dmu_tx_create(zfsvfs->z_os);
        dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
        zfs_sa_upgrade_txholds(tx, zp);
        if (end > zp->z_blksz &&
            (!ISP2(zp->z_blksz) || zp->z_blksz < zfsvfs->z_max_blksz)) {
                /*
                 * We are growing the file past the current block size.
                 */
                if (zp->z_blksz > zp->z_zfsvfs->z_max_blksz) {
                        /*
                         * File's blocksize is already larger than the
                         * "recordsize" property.  Only let it grow to
                         * the next power of 2.
                         */
                        ASSERT(!ISP2(zp->z_blksz));
                        newblksz = MIN(end, 1 << highbit64(zp->z_blksz));
                } else {
                        newblksz = MIN(end, zp->z_zfsvfs->z_max_blksz);
                }
                dmu_tx_hold_write(tx, zp->z_id, 0, newblksz);
        } else {
                newblksz = 0;
        }

        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
                dmu_tx_abort(tx);
                rangelock_exit(lr);
                return (error);
        }

        if (newblksz)
                zfs_grow_blocksize(zp, newblksz, tx);

        zp->z_size = end;

        VERIFY(0 == sa_update(zp->z_sa_hdl, SA_ZPL_SIZE(zp->z_zfsvfs),
            &zp->z_size, sizeof (zp->z_size), tx));

        rangelock_exit(lr);

        dmu_tx_commit(tx);

        return (0);
}

/*
 * Free space in a file.
 *
 *      IN:     zp      - znode of file to free data in.
 *              off     - start of section to free.
 *              len     - length of section to free.
 *
 *      RETURN: 0 on success, error code on failure
 */
static int
zfs_free_range(znode_t *zp, uint64_t off, uint64_t len)
{
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        locked_range_t *lr;
        int error;

        /*
         * Lock the range being freed.
         */
        lr = rangelock_enter(&zp->z_rangelock, off, len, RL_WRITER);

        /*
         * Nothing to do if file already at desired length.
         */
        if (off >= zp->z_size) {
                rangelock_exit(lr);
                return (0);
        }

        if (off + len > zp->z_size)
                len = zp->z_size - off;

        error = dmu_free_long_range(zfsvfs->z_os, zp->z_id, off, len);

        rangelock_exit(lr);

        return (error);
}

/*
 * Truncate a file
 *
 *      IN:     zp      - znode of file to free data in.
 *              end     - new end-of-file.
 *
 *      RETURN: 0 on success, error code on failure
 */
static int
zfs_trunc(znode_t *zp, uint64_t end)
{
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        vnode_t *vp = ZTOV(zp);
        dmu_tx_t *tx;
        locked_range_t *lr;
        int error;
        sa_bulk_attr_t bulk[2];
        int count = 0;

        /*
         * We will change zp_size, lock the whole file.
         */
        lr = rangelock_enter(&zp->z_rangelock, 0, UINT64_MAX, RL_WRITER);

        /*
         * Nothing to do if file already at desired length.
         */
        if (end >= zp->z_size) {
                rangelock_exit(lr);
                return (0);
        }

        error = dmu_free_long_range(zfsvfs->z_os, zp->z_id, end,
            DMU_OBJECT_END);
        if (error) {
                rangelock_exit(lr);
                return (error);
        }
        tx = dmu_tx_create(zfsvfs->z_os);
        dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
        zfs_sa_upgrade_txholds(tx, zp);
        dmu_tx_mark_netfree(tx);
        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
                dmu_tx_abort(tx);
                rangelock_exit(lr);
                return (error);
        }

        zp->z_size = end;
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_SIZE(zfsvfs),
            NULL, &zp->z_size, sizeof (zp->z_size));

        if (end == 0) {
                zp->z_pflags &= ~ZFS_SPARSE;
                SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
                    NULL, &zp->z_pflags, 8);
        }
        VERIFY(sa_bulk_update(zp->z_sa_hdl, bulk, count, tx) == 0);

        dmu_tx_commit(tx);

        /*
         * Clear any mapped pages in the truncated region.  This has to
         * happen outside of the transaction to avoid the possibility of
         * a deadlock with someone trying to push a page that we are
         * about to invalidate.
         */
        if (vn_has_cached_data(vp)) {
                page_t *pp;
                uint64_t start = end & PAGEMASK;
                int poff = end & PAGEOFFSET;

                if (poff != 0 && (pp = page_lookup(vp, start, SE_SHARED))) {
                        /*
                         * We need to zero a partial page.
                         */
                        pagezero(pp, poff, PAGESIZE - poff);
                        start += PAGESIZE;
                        page_unlock(pp);
                }
                error = pvn_vplist_dirty(vp, start, zfs_no_putpage,
                    B_INVAL | B_TRUNC, NULL);
                ASSERT(error == 0);
        }

        rangelock_exit(lr);

        return (0);
}

/*
 * Free space in a file
 *
 *      IN:     zp      - znode of file to free data in.
 *              off     - start of range
 *              len     - end of range (0 => EOF)
 *              flag    - current file open mode flags.
 *              log     - TRUE if this action should be logged
 *
 *      RETURN: 0 on success, error code on failure
 */
int
zfs_freesp(znode_t *zp, uint64_t off, uint64_t len, int flag, boolean_t log)
{
        vnode_t *vp = ZTOV(zp);
        dmu_tx_t *tx;
        zfsvfs_t *zfsvfs = zp->z_zfsvfs;
        zilog_t *zilog = zfsvfs->z_log;
        uint64_t mode;
        uint64_t mtime[2], ctime[2];
        sa_bulk_attr_t bulk[3];
        int count = 0;
        int error;

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

        if (off > zp->z_size) {
                error =  zfs_extend(zp, off+len);
                if (error == 0 && log)
                        goto log;
                else
                        return (error);
        }

        /*
         * Check for any locks in the region to be freed.
         */

        if (MANDLOCK(vp, (mode_t)mode)) {
                uint64_t length = (len ? len : zp->z_size - off);
                if (error = chklock(vp, FWRITE, off, length, flag, NULL))
                        return (error);
        }

        if (len == 0) {
                error = zfs_trunc(zp, off);
        } else {
                if ((error = zfs_free_range(zp, off, len)) == 0 &&
                    off + len > zp->z_size)
                        error = zfs_extend(zp, off+len);
        }
        if (error || !log)
                return (error);
log:
        tx = dmu_tx_create(zfsvfs->z_os);
        dmu_tx_hold_sa(tx, zp->z_sa_hdl, B_FALSE);
        zfs_sa_upgrade_txholds(tx, zp);
        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
                dmu_tx_abort(tx);
                return (error);
        }

        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_MTIME(zfsvfs), NULL, mtime, 16);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_CTIME(zfsvfs), NULL, ctime, 16);
        SA_ADD_BULK_ATTR(bulk, count, SA_ZPL_FLAGS(zfsvfs),
            NULL, &zp->z_pflags, 8);
        zfs_tstamp_update_setup(zp, CONTENT_MODIFIED, mtime, ctime, B_TRUE);
        error = sa_bulk_update(zp->z_sa_hdl, bulk, count, tx);
        ASSERT(error == 0);

        zfs_log_truncate(zilog, tx, TX_TRUNCATE, zp, off, len);

        dmu_tx_commit(tx);
        return (0);
}

void
zfs_create_fs(objset_t *os, cred_t *cr, nvlist_t *zplprops, dmu_tx_t *tx)
{
        uint64_t        moid, obj, sa_obj, version;
        uint64_t        sense = ZFS_CASE_SENSITIVE;
        uint64_t        norm = 0;
        nvpair_t        *elem;
        int             error;
        int             i;
        znode_t         *rootzp = NULL;
        zfsvfs_t        *zfsvfs;
        vnode_t         *vp;
        vattr_t         vattr;
        znode_t         *zp;
        zfs_acl_ids_t   acl_ids;

        /*
         * First attempt to create master node.
         */
        /*
         * In an empty objset, there are no blocks to read and thus
         * there can be no i/o errors (which we assert below).
         */
        moid = MASTER_NODE_OBJ;
        error = zap_create_claim(os, moid, DMU_OT_MASTER_NODE,
            DMU_OT_NONE, 0, tx);
        ASSERT(error == 0);

        /*
         * Set starting attributes.
         */
        version = zfs_zpl_version_map(spa_version(dmu_objset_spa(os)));
        elem = NULL;
        while ((elem = nvlist_next_nvpair(zplprops, elem)) != NULL) {
                /* For the moment we expect all zpl props to be uint64_ts */
                uint64_t val;
                char *name;

                ASSERT(nvpair_type(elem) == DATA_TYPE_UINT64);
                VERIFY(nvpair_value_uint64(elem, &val) == 0);
                name = nvpair_name(elem);
                if (strcmp(name, zfs_prop_to_name(ZFS_PROP_VERSION)) == 0) {
                        if (val < version)
                                version = val;
                } else {
                        error = zap_update(os, moid, name, 8, 1, &val, tx);
                }
                ASSERT(error == 0);
                if (strcmp(name, zfs_prop_to_name(ZFS_PROP_NORMALIZE)) == 0)
                        norm = val;
                else if (strcmp(name, zfs_prop_to_name(ZFS_PROP_CASE)) == 0)
                        sense = val;
        }
        ASSERT(version != 0);
        error = zap_update(os, moid, ZPL_VERSION_STR, 8, 1, &version, tx);

        /*
         * Create zap object used for SA attribute registration
         */

        if (version >= ZPL_VERSION_SA) {
                sa_obj = zap_create(os, DMU_OT_SA_MASTER_NODE,
                    DMU_OT_NONE, 0, tx);
                error = zap_add(os, moid, ZFS_SA_ATTRS, 8, 1, &sa_obj, tx);
                ASSERT(error == 0);
        } else {
                sa_obj = 0;
        }
        /*
         * Create a delete queue.
         */
        obj = zap_create(os, DMU_OT_UNLINKED_SET, DMU_OT_NONE, 0, tx);

        error = zap_add(os, moid, ZFS_UNLINKED_SET, 8, 1, &obj, tx);
        ASSERT(error == 0);

        /*
         * Create root znode.  Create minimal znode/vnode/zfsvfs
         * to allow zfs_mknode to work.
         */
        vattr.va_mask = AT_MODE|AT_UID|AT_GID|AT_TYPE;
        vattr.va_type = VDIR;
        vattr.va_mode = S_IFDIR|0755;
        vattr.va_uid = crgetuid(cr);
        vattr.va_gid = crgetgid(cr);

        rootzp = kmem_cache_alloc(znode_cache, KM_SLEEP);
        ASSERT(!POINTER_IS_VALID(rootzp->z_zfsvfs));
        rootzp->z_moved = 0;
        rootzp->z_unlinked = 0;
        rootzp->z_atime_dirty = 0;
        rootzp->z_is_sa = USE_SA(version, os);
        rootzp->z_pflags = 0;

        vp = ZTOV(rootzp);
        vn_reinit(vp);
        vp->v_type = VDIR;

        zfsvfs = kmem_zalloc(sizeof (zfsvfs_t), KM_SLEEP);
        zfsvfs->z_os = os;
        zfsvfs->z_parent = zfsvfs;
        zfsvfs->z_version = version;
        zfsvfs->z_use_fuids = USE_FUIDS(version, os);
        zfsvfs->z_use_sa = USE_SA(version, os);
        zfsvfs->z_norm = norm;

        error = sa_setup(os, sa_obj, zfs_attr_table, ZPL_END,
            &zfsvfs->z_attr_table);

        ASSERT(error == 0);

        /*
         * Fold case on file systems that are always or sometimes case
         * insensitive.
         */
        if (sense == ZFS_CASE_INSENSITIVE || sense == ZFS_CASE_MIXED)
                zfsvfs->z_norm |= U8_TEXTPREP_TOUPPER;

        mutex_init(&zfsvfs->z_znodes_lock, NULL, MUTEX_DEFAULT, NULL);
        list_create(&zfsvfs->z_all_znodes, sizeof (znode_t),
            offsetof(znode_t, z_link_node));

        for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
                mutex_init(&zfsvfs->z_hold_mtx[i], NULL, MUTEX_DEFAULT, NULL);

        rootzp->z_zfsvfs = zfsvfs;
        VERIFY(0 == zfs_acl_ids_create(rootzp, IS_ROOT_NODE, &vattr,
            cr, NULL, &acl_ids));
        zfs_mknode(rootzp, &vattr, tx, cr, IS_ROOT_NODE, &zp, &acl_ids);
        ASSERT3P(zp, ==, rootzp);
        ASSERT(!vn_in_dnlc(ZTOV(rootzp))); /* not valid to move */
        error = zap_add(os, moid, ZFS_ROOT_OBJ, 8, 1, &rootzp->z_id, tx);
        ASSERT(error == 0);
        zfs_acl_ids_free(&acl_ids);
        POINTER_INVALIDATE(&rootzp->z_zfsvfs);

        ZTOV(rootzp)->v_count = 0;
        sa_handle_destroy(rootzp->z_sa_hdl);
        kmem_cache_free(znode_cache, rootzp);

        /*
         * Create shares directory
         */

        error = zfs_create_share_dir(zfsvfs, tx);

        ASSERT(error == 0);

        for (i = 0; i != ZFS_OBJ_MTX_SZ; i++)
                mutex_destroy(&zfsvfs->z_hold_mtx[i]);
        kmem_free(zfsvfs, sizeof (zfsvfs_t));
}

#endif /* _KERNEL */

static int
zfs_sa_setup(objset_t *osp, sa_attr_type_t **sa_table)
{
        uint64_t sa_obj = 0;
        int error;

        error = zap_lookup(osp, MASTER_NODE_OBJ, ZFS_SA_ATTRS, 8, 1, &sa_obj);
        if (error != 0 && error != ENOENT)
                return (error);

        error = sa_setup(osp, sa_obj, zfs_attr_table, ZPL_END, sa_table);
        return (error);
}

static int
zfs_grab_sa_handle(objset_t *osp, uint64_t obj, sa_handle_t **hdlp,
    dmu_buf_t **db, void *tag)
{
        dmu_object_info_t doi;
        int error;

        if ((error = sa_buf_hold(osp, obj, tag, db)) != 0)
                return (error);

        dmu_object_info_from_db(*db, &doi);
        if ((doi.doi_bonus_type != DMU_OT_SA &&
            doi.doi_bonus_type != DMU_OT_ZNODE) ||
            doi.doi_bonus_type == DMU_OT_ZNODE &&
            doi.doi_bonus_size < sizeof (znode_phys_t)) {
                sa_buf_rele(*db, tag);
                return (SET_ERROR(ENOTSUP));
        }

        error = sa_handle_get(osp, obj, NULL, SA_HDL_PRIVATE, hdlp);
        if (error != 0) {
                sa_buf_rele(*db, tag);
                return (error);
        }

        return (0);
}

void
zfs_release_sa_handle(sa_handle_t *hdl, dmu_buf_t *db, void *tag)
{
        sa_handle_destroy(hdl);
        sa_buf_rele(db, tag);
}

/*
 * Given an object number, return its parent object number and whether
 * or not the object is an extended attribute directory.
 */
static int
zfs_obj_to_pobj(objset_t *osp, sa_handle_t *hdl, sa_attr_type_t *sa_table,
    uint64_t *pobjp, int *is_xattrdir)
{
        uint64_t parent;
        uint64_t pflags;
        uint64_t mode;
        uint64_t parent_mode;
        sa_bulk_attr_t bulk[3];
        sa_handle_t *sa_hdl;
        dmu_buf_t *sa_db;
        int count = 0;
        int error;

        SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_PARENT], NULL,
            &parent, sizeof (parent));
        SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_FLAGS], NULL,
            &pflags, sizeof (pflags));
        SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_MODE], NULL,
            &mode, sizeof (mode));

        if ((error = sa_bulk_lookup(hdl, bulk, count)) != 0)
                return (error);

        /*
         * When a link is removed its parent pointer is not changed and will
         * be invalid.  There are two cases where a link is removed but the
         * file stays around, when it goes to the delete queue and when there
         * are additional links.
         */
        error = zfs_grab_sa_handle(osp, parent, &sa_hdl, &sa_db, FTAG);
        if (error != 0)
                return (error);

        error = sa_lookup(sa_hdl, ZPL_MODE, &parent_mode, sizeof (parent_mode));
        zfs_release_sa_handle(sa_hdl, sa_db, FTAG);
        if (error != 0)
                return (error);

        *is_xattrdir = ((pflags & ZFS_XATTR) != 0) && S_ISDIR(mode);

        /*
         * Extended attributes can be applied to files, directories, etc.
         * Otherwise the parent must be a directory.
         */
        if (!*is_xattrdir && !S_ISDIR(parent_mode))
                return (SET_ERROR(EINVAL));

        *pobjp = parent;

        return (0);
}

/*
 * Given an object number, return some zpl level statistics
 */
static int
zfs_obj_to_stats_impl(sa_handle_t *hdl, sa_attr_type_t *sa_table,
    zfs_stat_t *sb)
{
        sa_bulk_attr_t bulk[4];
        int count = 0;

        SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_MODE], NULL,
            &sb->zs_mode, sizeof (sb->zs_mode));
        SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_GEN], NULL,
            &sb->zs_gen, sizeof (sb->zs_gen));
        SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_LINKS], NULL,
            &sb->zs_links, sizeof (sb->zs_links));
        SA_ADD_BULK_ATTR(bulk, count, sa_table[ZPL_CTIME], NULL,
            &sb->zs_ctime, sizeof (sb->zs_ctime));

        return (sa_bulk_lookup(hdl, bulk, count));
}

static int
zfs_obj_to_path_impl(objset_t *osp, uint64_t obj, sa_handle_t *hdl,
    sa_attr_type_t *sa_table, char *buf, int len)
{
        sa_handle_t *sa_hdl;
        sa_handle_t *prevhdl = NULL;
        dmu_buf_t *prevdb = NULL;
        dmu_buf_t *sa_db = NULL;
        char *path = buf + len - 1;
        int error;

        *path = '\0';
        sa_hdl = hdl;

        uint64_t deleteq_obj;
        VERIFY0(zap_lookup(osp, MASTER_NODE_OBJ,
            ZFS_UNLINKED_SET, sizeof (uint64_t), 1, &deleteq_obj));
        error = zap_lookup_int(osp, deleteq_obj, obj);
        if (error == 0) {
                return (ESTALE);
        } else if (error != ENOENT) {
                return (error);
        }
        error = 0;

        for (;;) {
                uint64_t pobj;
                char component[MAXNAMELEN + 2];
                size_t complen;
                int is_xattrdir;

                if (prevdb)
                        zfs_release_sa_handle(prevhdl, prevdb, FTAG);

                if ((error = zfs_obj_to_pobj(osp, sa_hdl, sa_table, &pobj,
                    &is_xattrdir)) != 0)
                        break;

                if (pobj == obj) {
                        if (path[0] != '/')
                                *--path = '/';
                        break;
                }

                component[0] = '/';
                if (is_xattrdir) {
                        (void) sprintf(component + 1, "<xattrdir>");
                } else {
                        error = zap_value_search(osp, pobj, obj,
                            ZFS_DIRENT_OBJ(-1ULL), component + 1);
                        if (error != 0)
                                break;
                }

                complen = strlen(component);
                path -= complen;
                ASSERT(path >= buf);
                bcopy(component, path, complen);
                obj = pobj;

                if (sa_hdl != hdl) {
                        prevhdl = sa_hdl;
                        prevdb = sa_db;
                }
                error = zfs_grab_sa_handle(osp, obj, &sa_hdl, &sa_db, FTAG);
                if (error != 0) {
                        sa_hdl = prevhdl;
                        sa_db = prevdb;
                        break;
                }
        }

        if (sa_hdl != NULL && sa_hdl != hdl) {
                ASSERT(sa_db != NULL);
                zfs_release_sa_handle(sa_hdl, sa_db, FTAG);
        }

        if (error == 0)
                (void) memmove(buf, path, buf + len - path);

        return (error);
}

int
zfs_obj_to_path(objset_t *osp, uint64_t obj, char *buf, int len)
{
        sa_attr_type_t *sa_table;
        sa_handle_t *hdl;
        dmu_buf_t *db;
        int error;

        error = zfs_sa_setup(osp, &sa_table);
        if (error != 0)
                return (error);

        error = zfs_grab_sa_handle(osp, obj, &hdl, &db, FTAG);
        if (error != 0)
                return (error);

        error = zfs_obj_to_path_impl(osp, obj, hdl, sa_table, buf, len);

        zfs_release_sa_handle(hdl, db, FTAG);
        return (error);
}

int
zfs_obj_to_stats(objset_t *osp, uint64_t obj, zfs_stat_t *sb,
    char *buf, int len)
{
        char *path = buf + len - 1;
        sa_attr_type_t *sa_table;
        sa_handle_t *hdl;
        dmu_buf_t *db;
        int error;

        *path = '\0';

        error = zfs_sa_setup(osp, &sa_table);
        if (error != 0)
                return (error);

        error = zfs_grab_sa_handle(osp, obj, &hdl, &db, FTAG);
        if (error != 0)
                return (error);

        error = zfs_obj_to_stats_impl(hdl, sa_table, sb);
        if (error != 0) {
                zfs_release_sa_handle(hdl, db, FTAG);
                return (error);
        }

        error = zfs_obj_to_path_impl(osp, obj, hdl, sa_table, buf, len);

        zfs_release_sa_handle(hdl, db, FTAG);
        return (error);
}