zfs-builds-mm/zfs-2.0.0-rc4/module/os/freebsd/spl/spl_uio.c
2020-10-22 14:20:35 +02:00

92 lines
2.4 KiB
C

/*
* CDDL HEADER START
*
* The contents of this file are subject to the terms of the
* Common Development and Distribution License (the "License").
* You may not use this file except in compliance with the License.
*
* You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
* or http://www.opensolaris.org/os/licensing.
* See the License for the specific language governing permissions
* and limitations under the License.
*
* When distributing Covered Code, include this CDDL HEADER in each
* file and include the License file at usr/src/OPENSOLARIS.LICENSE.
* If applicable, add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your own identifying
* information: Portions Copyright [yyyy] [name of copyright owner]
*
* CDDL HEADER END
*/
/*
* Copyright 2009 Sun Microsystems, Inc. All rights reserved.
* Use is subject to license terms.
*/
/* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/* All Rights Reserved */
/*
* University Copyright- Copyright (c) 1982, 1986, 1988
* The Regents of the University of California
* All Rights Reserved
*
* University Acknowledgment- Portions of this document are derived from
* software developed by the University of California, Berkeley, and its
* contributors.
*/
/*
* $FreeBSD$
*/
#include <sys/param.h>
#include <sys/uio.h>
#include <sys/vnode.h>
/*
* same as uiomove() but doesn't modify uio structure.
* return in cbytes how many bytes were copied.
*/
int
uiocopy(void *p, size_t n, enum uio_rw rw, struct uio *uio, size_t *cbytes)
{
struct iovec small_iovec[1];
struct uio small_uio_clone;
struct uio *uio_clone;
int error;
ASSERT3U(uio->uio_rw, ==, rw);
if (uio->uio_iovcnt == 1) {
small_uio_clone = *uio;
small_iovec[0] = *uio->uio_iov;
small_uio_clone.uio_iov = small_iovec;
uio_clone = &small_uio_clone;
} else {
uio_clone = cloneuio(uio);
}
error = vn_io_fault_uiomove(p, n, uio_clone);
*cbytes = uio->uio_resid - uio_clone->uio_resid;
if (uio_clone != &small_uio_clone)
free(uio_clone, M_IOV);
return (error);
}
/*
* Drop the next n chars out of *uiop.
*/
void
uioskip(uio_t *uio, size_t n)
{
enum uio_seg segflg;
/* For the full compatibility with illumos. */
if (n > uio->uio_resid)
return;
segflg = uio->uio_segflg;
uio->uio_segflg = UIO_NOCOPY;
uiomove(NULL, n, uio->uio_rw, uio);
uio->uio_segflg = segflg;
}