C++ dmu_tx_hold_zap函数代码示例

int
zfs_set_userquota(zfs_sb_t *zsb, zfs_userquota_prop_t type,
    const char *domain, uint64_t rid, uint64_t quota)
{
	char buf[32];
	int err;
	dmu_tx_t *tx;
	uint64_t *objp;
	boolean_t fuid_dirtied;

	if (type != ZFS_PROP_USERQUOTA && type != ZFS_PROP_GROUPQUOTA)
		return (SET_ERROR(EINVAL));

	if (zsb->z_version < ZPL_VERSION_USERSPACE)
		return (SET_ERROR(ENOTSUP));

	objp = (type == ZFS_PROP_USERQUOTA) ? &zsb->z_userquota_obj :
	    &zsb->z_groupquota_obj;

	err = id_to_fuidstr(zsb, domain, rid, buf, B_TRUE);
	if (err)
		return (err);
	fuid_dirtied = zsb->z_fuid_dirty;

	tx = dmu_tx_create(zsb->z_os);
	dmu_tx_hold_zap(tx, *objp ? *objp : DMU_NEW_OBJECT, B_TRUE, NULL);
	if (*objp == 0) {
		dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, B_TRUE,
		    zfs_userquota_prop_prefixes[type]);
	}
	if (fuid_dirtied)
		zfs_fuid_txhold(zsb, tx);
	err = dmu_tx_assign(tx, TXG_WAIT);
	if (err) {
		dmu_tx_abort(tx);
		return (err);
	}

	mutex_enter(&zsb->z_lock);
	if (*objp == 0) {
		*objp = zap_create(zsb->z_os, DMU_OT_USERGROUP_QUOTA,
		    DMU_OT_NONE, 0, tx);
		VERIFY(0 == zap_add(zsb->z_os, MASTER_NODE_OBJ,
		    zfs_userquota_prop_prefixes[type], 8, 1, objp, tx));
	}
	mutex_exit(&zsb->z_lock);

	if (quota == 0) {
		err = zap_remove(zsb->z_os, *objp, buf, tx);
		if (err == ENOENT)
			err = 0;
	} else {
		err = zap_update(zsb->z_os, *objp, buf, 8, 1, &quota, tx);
	}
	ASSERT(err == 0);
	if (fuid_dirtied)
		zfs_fuid_sync(zsb, tx);
	dmu_tx_commit(tx);
	return (err);
}

/*
 * Delete the entire contents of a directory.  Return a count
 * of the number of entries that could not be deleted. If we encounter
 * an error, return a count of at least one so that the directory stays
 * in the unlinked set.
 *
 * NOTE: this function assumes that the directory is inactive,
 *	so there is no need to lock its entries before deletion.
 *	Also, it assumes the directory contents is *only* regular
 *	files.
 */
static int
zfs_purgedir(znode_t *dzp)
{
	zap_cursor_t	zc;
	zap_attribute_t	zap;
	znode_t		*xzp;
	dmu_tx_t	*tx;
	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
	zfs_dirlock_t	dl;
	int skipped = 0;
	int error;

	for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
	    (error = zap_cursor_retrieve(&zc, &zap)) == 0;
	    zap_cursor_advance(&zc)) {
		error = zfs_zget(zfsvfs,
		    ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
		if (error) {
			skipped += 1;
			continue;
		}

/*
	    ASSERT((ZTOV(xzp)->v_type == VREG) ||
		    (ZTOV(xzp)->v_type == VLNK));
*/

		tx = dmu_tx_create(zfsvfs->z_os);
		dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
		dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
		dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
		dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
		/* Is this really needed ? */
		zfs_sa_upgrade_txholds(tx, xzp);
		error = dmu_tx_assign(tx, TXG_WAIT);
		if (error) {
			dmu_tx_abort(tx);
			//VN_RELE(ZTOV(xzp)); // async
			VN_RELE_ASYNC(ZTOV(xzp), dsl_pool_vnrele_taskq(dmu_objset_pool(zfsvfs->z_os)));
			skipped += 1;
			continue;
		}
		bzero(&dl, sizeof (dl));
		dl.dl_dzp = dzp;
		dl.dl_name = zap.za_name;

		error = zfs_link_destroy(&dl, xzp, tx, 0, NULL);
		if (error)
			skipped += 1;
		dmu_tx_commit(tx);

		//VN_RELE(ZTOV(xzp)); // async
		VN_RELE_ASYNC(ZTOV(xzp), dsl_pool_vnrele_taskq(dmu_objset_pool(zfsvfs->z_os)));
	}
	zap_cursor_fini(&zc);
	if (error != ENOENT)
		skipped += 1;
	return (skipped);
}

int
zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr)
{
	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
	znode_t *xzp;
	dmu_tx_t *tx;
	int error;
	zfs_fuid_info_t *fuidp = NULL;

	*xvpp = NULL;

	/*
	 * In FreeBSD, access checking for creating an EA is being done
	 * in zfs_setextattr(),
	 */
#ifndef __FreeBSD__
	if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr))
		return (error);
#endif

	tx = dmu_tx_create(zfsvfs->z_os);
	dmu_tx_hold_bonus(tx, zp->z_id);
	dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
	if (IS_EPHEMERAL(crgetuid(cr)) || IS_EPHEMERAL(crgetgid(cr))) {
		if (zfsvfs->z_fuid_obj == 0) {
			dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
			dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
			    FUID_SIZE_ESTIMATE(zfsvfs));
			dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL);
		} else {
			dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj);
			dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0,
			    FUID_SIZE_ESTIMATE(zfsvfs));
		}
	}
	error = dmu_tx_assign(tx, zfsvfs->z_assign);
	if (error) {
		if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT)
			dmu_tx_wait(tx);
		dmu_tx_abort(tx);
		return (error);
	}
	zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, 0, NULL, &fuidp);
	ASSERT(xzp->z_phys->zp_parent == zp->z_id);
	dmu_buf_will_dirty(zp->z_dbuf, tx);
	zp->z_phys->zp_xattr = xzp->z_id;

	(void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp,
	    xzp, "", NULL, fuidp, vap);
	if (fuidp)
		zfs_fuid_info_free(fuidp);
	dmu_tx_commit(tx);

	*xvpp = ZTOV(xzp);

	return (0);
}

/*
 * Delete the entire contents of a directory.  Return a count
 * of the number of entries that could not be deleted. If we encounter
 * an error, return a count of at least one so that the directory stays
 * in the unlinked set.
 *
 * NOTE: this function assumes that the directory is inactive,
 *	so there is no need to lock its entries before deletion.
 *	Also, it assumes the directory contents is *only* regular
 *	files.
 */
static int
zfs_purgedir(znode_t *dzp)
{
	zap_cursor_t	zc;
	zap_attribute_t	zap;
	znode_t		*xzp;
	dmu_tx_t	*tx;
	zfsvfs_t	*zfsvfs = ZTOZSB(dzp);
	zfs_dirlock_t	dl;
	int skipped = 0;
	int error;

	for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
	    (error = zap_cursor_retrieve(&zc, &zap)) == 0;
	    zap_cursor_advance(&zc)) {
		error = zfs_zget(zfsvfs,
		    ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
		if (error) {
			skipped += 1;
			continue;
		}

		ASSERT(S_ISREG(ZTOI(xzp)->i_mode) ||
		    S_ISLNK(ZTOI(xzp)->i_mode));

		tx = dmu_tx_create(zfsvfs->z_os);
		dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
		dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
		dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
		dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
		/* Is this really needed ? */
		zfs_sa_upgrade_txholds(tx, xzp);
		dmu_tx_mark_netfree(tx);
		error = dmu_tx_assign(tx, TXG_WAIT);
		if (error) {
			dmu_tx_abort(tx);
			zfs_iput_async(ZTOI(xzp));
			skipped += 1;
			continue;
		}
		bzero(&dl, sizeof (dl));
		dl.dl_dzp = dzp;
		dl.dl_name = zap.za_name;

		error = zfs_link_destroy(&dl, xzp, tx, 0, NULL);
		if (error)
			skipped += 1;
		dmu_tx_commit(tx);

		zfs_iput_async(ZTOI(xzp));
	}
	zap_cursor_fini(&zc);
	if (error != ENOENT)
		skipped += 1;
	return (skipped);
}

/*
 * Delete the entire contents of a directory.  Return a count
 * of the number of entries that could not be deleted. If we encounter
 * an error, return a count of at least one so that the directory stays
 * in the unlinked set.
 *
 * NOTE: this function assumes that the directory is inactive,
 *	so there is no need to lock its entries before deletion.
 *	Also, it assumes the directory contents is *only* regular
 *	files.
 */
static int
zfs_purgedir(znode_t *dzp)
{
    zap_cursor_t	zc;
    zap_attribute_t	zap;
    znode_t		*xzp;
    dmu_tx_t	*tx;
    zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
    int skipped = 0;
    int error;

    for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
            (error = zap_cursor_retrieve(&zc, &zap)) == 0;
            zap_cursor_advance(&zc)) {
        error = zfs_zget(zfsvfs,
                         ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
        if (error) {
            skipped += 1;
            continue;
        }

        vn_lock(ZTOV(xzp), LK_EXCLUSIVE | LK_RETRY);
        ASSERT((ZTOV(xzp)->v_type == VREG) ||
               (ZTOV(xzp)->v_type == VLNK));

        tx = dmu_tx_create(zfsvfs->z_os);
        dmu_tx_hold_sa(tx, dzp->z_sa_hdl, B_FALSE);
        dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
        dmu_tx_hold_sa(tx, xzp->z_sa_hdl, B_FALSE);
        dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
        /* Is this really needed ? */
        zfs_sa_upgrade_txholds(tx, xzp);
        dmu_tx_mark_netfree(tx);
        error = dmu_tx_assign(tx, TXG_WAIT);
        if (error) {
            dmu_tx_abort(tx);
            vput(ZTOV(xzp));
            skipped += 1;
            continue;
        }

        error = zfs_link_destroy(dzp, zap.za_name, xzp, tx, 0, NULL);
        if (error)
            skipped += 1;
        dmu_tx_commit(tx);

        vput(ZTOV(xzp));
    }
    zap_cursor_fini(&zc);
    if (error != ENOENT)
        skipped += 1;
    return (skipped);
}

int
zfs_set_version(zfs_sb_t *zsb, uint64_t newvers)
{
	int error;
	objset_t *os = zsb->z_os;
	dmu_tx_t *tx;

	if (newvers < ZPL_VERSION_INITIAL || newvers > ZPL_VERSION)
		return (SET_ERROR(EINVAL));

	if (newvers < zsb->z_version)
		return (SET_ERROR(EINVAL));

	if (zfs_spa_version_map(newvers) >
	    spa_version(dmu_objset_spa(zsb->z_os)))
		return (SET_ERROR(ENOTSUP));

	tx = dmu_tx_create(os);
	dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, B_FALSE, ZPL_VERSION_STR);
	if (newvers >= ZPL_VERSION_SA && !zsb->z_use_sa) {
		dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, B_TRUE,
		    ZFS_SA_ATTRS);
		dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
	}
	error = dmu_tx_assign(tx, TXG_WAIT);
	if (error) {
		dmu_tx_abort(tx);
		return (error);
	}

	error = zap_update(os, MASTER_NODE_OBJ, ZPL_VERSION_STR,
	    8, 1, &newvers, tx);

	if (error) {
		dmu_tx_commit(tx);
		return (error);
	}

	if (newvers >= ZPL_VERSION_SA && !zsb->z_use_sa) {
		uint64_t sa_obj;

		ASSERT3U(spa_version(dmu_objset_spa(zsb->z_os)), >=,
		    SPA_VERSION_SA);
		sa_obj = zap_create(os, DMU_OT_SA_MASTER_NODE,
		    DMU_OT_NONE, 0, tx);

		error = zap_add(os, MASTER_NODE_OBJ,
		    ZFS_SA_ATTRS, 8, 1, &sa_obj, tx);
		ASSERT0(error);

		VERIFY(0 == sa_set_sa_object(os, sa_obj));
		sa_register_update_callback(os, zfs_sa_upgrade);
	}

static int osd_declare_object_destroy(const struct lu_env *env,
				      struct dt_object *dt,
				      struct thandle *th)
{
	char			*buf = osd_oti_get(env)->oti_str;
	const struct lu_fid	*fid = lu_object_fid(&dt->do_lu);
	struct osd_object	*obj = osd_dt_obj(dt);
	struct osd_device	*osd = osd_obj2dev(obj);
	struct osd_thandle	*oh;
	int			 rc;
	uint64_t		 zapid;
	ENTRY;

	LASSERT(th != NULL);
	LASSERT(dt_object_exists(dt));

	oh = container_of0(th, struct osd_thandle, ot_super);
	LASSERT(oh->ot_tx != NULL);

	/* declare that we'll remove object from fid-dnode mapping */
	zapid = osd_get_name_n_idx(env, osd, fid, buf);
	dmu_tx_hold_bonus(oh->ot_tx, zapid);
	dmu_tx_hold_zap(oh->ot_tx, zapid, FALSE, buf);

	osd_declare_xattrs_destroy(env, obj, oh);

	/* declare that we'll remove object from inode accounting ZAPs */
	dmu_tx_hold_bonus(oh->ot_tx, osd->od_iusr_oid);
	dmu_tx_hold_zap(oh->ot_tx, osd->od_iusr_oid, FALSE, buf);
	dmu_tx_hold_bonus(oh->ot_tx, osd->od_igrp_oid);
	dmu_tx_hold_zap(oh->ot_tx, osd->od_igrp_oid, FALSE, buf);

	/* one less inode */
	rc = osd_declare_quota(env, osd, obj->oo_attr.la_uid,
			       obj->oo_attr.la_gid, -1, oh, false, NULL, false);
	if (rc)
		RETURN(rc);

	/* data to be truncated */
	rc = osd_declare_quota(env, osd, obj->oo_attr.la_uid,
			       obj->oo_attr.la_gid, 0, oh, true, NULL, false);
	if (rc)
		RETURN(rc);

	osd_object_set_destroy_type(obj);
	if (obj->oo_destroy == OSD_DESTROY_SYNC)
		dmu_tx_hold_free(oh->ot_tx, obj->oo_db->db_object,
				 0, DMU_OBJECT_END);
	else
		dmu_tx_hold_zap(oh->ot_tx, osd->od_unlinkedid, TRUE, NULL);

	RETURN(0);
}

/*
 * Delete the entire contents of a directory.  Return a count
 * of the number of entries that could not be deleted. If we encounter
 * an error, return a count of at least one so that the directory stays
 * in the unlinked set.
 *
 * NOTE: this function assumes that the directory is inactive,
 *	so there is no need to lock its entries before deletion.
 *	Also, it assumes the directory contents is *only* regular
 *	files.
 */
static int
zfs_purgedir(znode_t *dzp)
{
	zap_cursor_t	zc;
	zap_attribute_t	zap;
	znode_t		*xzp;
	dmu_tx_t	*tx;
	zfsvfs_t	*zfsvfs = dzp->z_zfsvfs;
	zfs_dirlock_t	dl;
	int skipped = 0;
	int error;

	for (zap_cursor_init(&zc, zfsvfs->z_os, dzp->z_id);
	    (error = zap_cursor_retrieve(&zc, &zap)) == 0;
	    zap_cursor_advance(&zc)) {
		error = zfs_zget(zfsvfs,
		    ZFS_DIRENT_OBJ(zap.za_first_integer), &xzp);
		if (error) {
			skipped += 1;
			continue;
		}

		ASSERT((ZTOV(xzp)->v_type == VREG) ||
		    (ZTOV(xzp)->v_type == VLNK));

		tx = dmu_tx_create(zfsvfs->z_os);
		dmu_tx_hold_bonus(tx, dzp->z_id);
		dmu_tx_hold_zap(tx, dzp->z_id, FALSE, zap.za_name);
		dmu_tx_hold_bonus(tx, xzp->z_id);
		dmu_tx_hold_zap(tx, zfsvfs->z_unlinkedobj, FALSE, NULL);
		error = dmu_tx_assign(tx, TXG_WAIT);
		if (error) {
			dmu_tx_abort(tx);
			VN_RELE(ZTOV(xzp));
			skipped += 1;
			continue;
		}
		bzero(&dl, sizeof (dl));
		dl.dl_dzp = dzp;
		dl.dl_name = zap.za_name;

		error = zfs_link_destroy(&dl, xzp, tx, 0, NULL);
		if (error)
			skipped += 1;
		dmu_tx_commit(tx);

		VN_RELE(ZTOV(xzp));
	}
	zap_cursor_fini(&zc);
	if (error != ENOENT)
		skipped += 1;
	return (skipped);
}

static void
__osd_xattr_declare_del(const struct lu_env *env, struct osd_object *obj,
			const char *name, struct osd_thandle *oh)
{
	struct osd_device *osd = osd_obj2dev(obj);
	dmu_tx_t          *tx = oh->ot_tx;
	uint64_t           xa_data_obj;
	int                rc;

	/* update SA_ZPL_DXATTR if xattr was in SA */
	dmu_tx_hold_sa(tx, obj->oo_sa_hdl, 0);

	if (obj->oo_xattr == ZFS_NO_OBJECT)
		return;

	rc = -zap_lookup(osd->od_os, obj->oo_xattr, name, 8, 1, &xa_data_obj);
	if (rc == 0) {
		/*
		 * Entry exists.
		 * We'll delete the existing object and ZAP entry.
		 */
		dmu_tx_hold_bonus(tx, xa_data_obj);
		dmu_tx_hold_free(tx, xa_data_obj, 0, DMU_OBJECT_END);
		dmu_tx_hold_zap(tx, obj->oo_xattr, FALSE, (char *) name);
		return;
	} else if (rc == -ENOENT) {
		/*
		 * Entry doesn't exist, nothing to be changed.
		 */
		return;
	}

	/* An error happened */
	tx->tx_err = -rc;
}

/*
 * Ensure the zap is flushed then inform the VFS of the capacity change.
 */
static int
zvol_update_volsize(uint64_t volsize, objset_t *os)
{
	dmu_tx_t *tx;
	int error;
	uint64_t txg;

	ASSERT(MUTEX_HELD(&zvol_state_lock));

	tx = dmu_tx_create(os);
	dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
	dmu_tx_mark_netfree(tx);
	error = dmu_tx_assign(tx, TXG_WAIT);
	if (error) {
		dmu_tx_abort(tx);
		return (SET_ERROR(error));
	}
	txg = dmu_tx_get_txg(tx);

	error = zap_update(os, ZVOL_ZAP_OBJ, "size", 8, 1,
	    &volsize, tx);
	dmu_tx_commit(tx);

	txg_wait_synced(dmu_objset_pool(os), txg);

	if (error == 0)
		error = dmu_free_long_range(os,
		    ZVOL_OBJ, volsize, DMU_OBJECT_END);

	return (error);
}

int
zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr)
{
	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
	znode_t *xzp;
	dmu_tx_t *tx;
	int error;
	zfs_acl_ids_t acl_ids;
	boolean_t fuid_dirtied;

	*xvpp = NULL;

	if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, 0, B_FALSE, cr))
		return (error);

	if ((error = zfs_acl_ids_create(zp, IS_XATTR, vap, cr, NULL,
	    &acl_ids)) != 0)
		return (error);
	if (zfs_acl_ids_overquota(zfsvfs, &acl_ids)) {
		zfs_acl_ids_free(&acl_ids);
		return (EDQUOT);
	}

	tx = dmu_tx_create(zfsvfs->z_os);
	dmu_tx_hold_bonus(tx, zp->z_id);
	dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
	fuid_dirtied = zfsvfs->z_fuid_dirty;
	if (fuid_dirtied)
		zfs_fuid_txhold(zfsvfs, tx);
	error = dmu_tx_assign(tx, TXG_NOWAIT);
	if (error) {
		zfs_acl_ids_free(&acl_ids);
		if (error == ERESTART)
			dmu_tx_wait(tx);
		dmu_tx_abort(tx);
		return (error);
	}
	zfs_mknode(zp, vap, tx, cr, IS_XATTR, &xzp, 0, &acl_ids);

	if (fuid_dirtied)
		zfs_fuid_sync(zfsvfs, tx);

	ASSERT(xzp->z_phys->zp_parent == zp->z_id);
	dmu_buf_will_dirty(zp->z_dbuf, tx);
	zp->z_phys->zp_xattr = xzp->z_id;

	(void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp,
	    xzp, "", NULL, acl_ids.z_fuidp, vap);

	zfs_acl_ids_free(&acl_ids);
	dmu_tx_commit(tx);

	*xvpp = ZTOV(xzp);

	return (0);
}

int
zvol_set_volsize(zfs_cmd_t *zc)
{
	zvol_state_t *zv;
	dev_t dev = zc->zc_dev;
	dmu_tx_t *tx;
	int error;
	dmu_object_info_t doi;

	mutex_enter(&zvol_state_lock);

	if ((zv = zvol_minor_lookup(zc->zc_name)) == NULL) {
		mutex_exit(&zvol_state_lock);
		return (ENXIO);
	}

	if ((error = dmu_object_info(zv->zv_objset, ZVOL_OBJ, &doi)) != 0 ||
	    (error = zvol_check_volsize(zc, doi.doi_data_block_size)) != 0) {
		mutex_exit(&zvol_state_lock);
		return (error);
	}

	if (zv->zv_readonly || (zv->zv_mode & DS_MODE_READONLY)) {
		mutex_exit(&zvol_state_lock);
		return (EROFS);
	}

	tx = dmu_tx_create(zv->zv_objset);
	dmu_tx_hold_zap(tx, ZVOL_ZAP_OBJ, TRUE, NULL);
	dmu_tx_hold_free(tx, ZVOL_OBJ, zc->zc_volsize, DMU_OBJECT_END);
	error = dmu_tx_assign(tx, TXG_WAIT);
	if (error) {
		dmu_tx_abort(tx);
		mutex_exit(&zvol_state_lock);
		return (error);
	}

	error = zap_update(zv->zv_objset, ZVOL_ZAP_OBJ, "size", 8, 1,
	    &zc->zc_volsize, tx);
	if (error == 0) {
		error = dmu_free_range(zv->zv_objset, ZVOL_OBJ, zc->zc_volsize,
		    DMU_OBJECT_END, tx);
	}

	dmu_tx_commit(tx);

	if (error == 0) {
		zv->zv_volsize = zc->zc_volsize;
		zvol_size_changed(zv, dev);
	}

	mutex_exit(&zvol_state_lock);

	return (error);
}

void
zfs_fuid_txhold(zfsvfs_t *zfsvfs, dmu_tx_t *tx)
{
	if (zfsvfs->z_fuid_obj == 0) {
		dmu_tx_hold_bonus(tx, DMU_NEW_OBJECT);
		dmu_tx_hold_write(tx, DMU_NEW_OBJECT, 0,
		    FUID_SIZE_ESTIMATE(zfsvfs));
		dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, FALSE, NULL);
	} else {
		dmu_tx_hold_bonus(tx, zfsvfs->z_fuid_obj);
		dmu_tx_hold_write(tx, zfsvfs->z_fuid_obj, 0,
		    FUID_SIZE_ESTIMATE(zfsvfs));
	}
}

int
zfs_set_version(const char *name, uint64_t newvers)
{
	int error;
	objset_t *os;
	dmu_tx_t *tx;
	uint64_t curvers;

	/*
	 * XXX for now, require that the filesystem be unmounted.  Would
	 * be nice to find the zfsvfs_t and just update that if
	 * possible.
	 */

	if (newvers < ZPL_VERSION_INITIAL || newvers > ZPL_VERSION)
		return (EINVAL);

	error = dmu_objset_open(name, DMU_OST_ZFS, DS_MODE_PRIMARY, &os);
	if (error)
		return (error);

	error = zap_lookup(os, MASTER_NODE_OBJ, ZPL_VERSION_STR,
	    8, 1, &curvers);
	if (error)
		goto out;
	if (newvers < curvers) {
		error = EINVAL;
		goto out;
	}

	tx = dmu_tx_create(os);
	dmu_tx_hold_zap(tx, MASTER_NODE_OBJ, 0, ZPL_VERSION_STR);
	error = dmu_tx_assign(tx, TXG_WAIT);
	if (error) {
		dmu_tx_abort(tx);
		goto out;
	}
	error = zap_update(os, MASTER_NODE_OBJ, ZPL_VERSION_STR, 8, 1,
	    &newvers, tx);

	spa_history_internal_log(LOG_DS_UPGRADE,
	    dmu_objset_spa(os), tx, CRED(),
	    "oldver=%llu newver=%llu dataset = %llu", curvers, newvers,
	    dmu_objset_id(os));
	dmu_tx_commit(tx);

out:
	dmu_objset_close(os);
	return (error);
}

int
zfs_make_xattrdir(znode_t *zp, vattr_t *vap, vnode_t **xvpp, cred_t *cr)
{
	zfsvfs_t *zfsvfs = zp->z_zfsvfs;
	znode_t *xzp;
	dmu_tx_t *tx;
	uint64_t xoid;
	int error;

	*xvpp = NULL;

#ifndef __APPLE__
	/* In Mac OS X access preflighting is done above the file system. */
	if (error = zfs_zaccess(zp, ACE_WRITE_NAMED_ATTRS, cr))
		return (error);
#endif /*!__APPLE__*/

	tx = dmu_tx_create(zfsvfs->z_os);
	dmu_tx_hold_bonus(tx, zp->z_id);
	dmu_tx_hold_zap(tx, DMU_NEW_OBJECT, FALSE, NULL);
	error = dmu_tx_assign(tx, zfsvfs->z_assign);
	if (error) {
		if (error == ERESTART && zfsvfs->z_assign == TXG_NOWAIT)
			dmu_tx_wait(tx);
		dmu_tx_abort(tx);
		return (error);
	}
	zfs_mknode(zp, vap, &xoid, tx, cr, IS_XATTR, &xzp, 0);
	ASSERT(xzp->z_id == xoid);
	ASSERT(xzp->z_phys->zp_parent == zp->z_id);
	dmu_buf_will_dirty(zp->z_dbuf, tx);
	zp->z_phys->zp_xattr = xoid;

	(void) zfs_log_create(zfsvfs->z_log, tx, TX_MKXATTR, zp, xzp, "");
	dmu_tx_commit(tx);
#ifdef __APPLE__
	/*
	 * Obtain and attach the vnode after committing the transaction
	 */
	zfs_attach_vnode(xzp);
#endif
	*xvpp = ZTOV(xzp);

	return (0);
}