module/os/freebsd/spl/spl_uio.c

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or https://opensource.org/licenses/CDDL-1.0.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21 /*
  22  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
  23  * Use is subject to license terms.
  24  */
  25
  26 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
  27 /* All Rights Reserved   */
  28
  29 /*
  30  * University Copyright- Copyright (c) 1982, 1986, 1988
  31  * The Regents of the University of California
  32  * All Rights Reserved
  33  *
  34  * University Acknowledgment- Portions of this document are derived from
  35  * software developed by the University of California, Berkeley, and its
  36  * contributors.
  37  */
  38
  39 /*
  40  * $FreeBSD$
  41  */
  42
  43 #include <sys/param.h>
  44 #include <sys/uio_impl.h>
  45 #include <sys/vnode.h>
  46 #include <sys/zfs_znode.h>
  47
  48 int
  49 zfs_uiomove(void *cp, size_t n, zfs_uio_rw_t dir, zfs_uio_t *uio)
  50 {
  51         ASSERT3U(zfs_uio_rw(uio), ==, dir);
  52         return (uiomove(cp, (int)n, GET_UIO_STRUCT(uio)));
  53 }
  54
  55 /*
  56  * same as zfs_uiomove() but doesn't modify uio structure.
  57  * return in cbytes how many bytes were copied.
  58  */
  59 int
  60 zfs_uiocopy(void *p, size_t n, zfs_uio_rw_t rw, zfs_uio_t *uio, size_t *cbytes)
  61 {
  62         struct iovec small_iovec[1];
  63         struct uio small_uio_clone;
  64         struct uio *uio_clone;
  65         int error;
  66
  67         ASSERT3U(zfs_uio_rw(uio), ==, rw);
  68         if (zfs_uio_iovcnt(uio) == 1) {
  69                 small_uio_clone = *(GET_UIO_STRUCT(uio));
  70                 small_iovec[0] = *(GET_UIO_STRUCT(uio)->uio_iov);
  71                 small_uio_clone.uio_iov = small_iovec;
  72                 uio_clone = &small_uio_clone;
  73         } else {
  74                 uio_clone = cloneuio(GET_UIO_STRUCT(uio));
  75         }
  76
  77         error = vn_io_fault_uiomove(p, n, uio_clone);
  78         *cbytes = zfs_uio_resid(uio) - uio_clone->uio_resid;
  79         if (uio_clone != &small_uio_clone)
  80                 free(uio_clone, M_IOV);
  81         return (error);
  82 }
  83
  84 /*
  85  * Drop the next n chars out of *uiop.
  86  */
  87 void
  88 zfs_uioskip(zfs_uio_t *uio, size_t n)
  89 {
  90         zfs_uio_seg_t segflg;
  91
  92         /* For the full compatibility with illumos. */
  93         if (n > zfs_uio_resid(uio))
  94                 return;
  95
  96         segflg = zfs_uio_segflg(uio);
  97         zfs_uio_segflg(uio) = UIO_NOCOPY;
  98         zfs_uiomove(NULL, n, zfs_uio_rw(uio), uio);
  99         zfs_uio_segflg(uio) = segflg;
 100 }
 101
 102 int
 103 zfs_uio_fault_move(void *p, size_t n, zfs_uio_rw_t dir, zfs_uio_t *uio)
 104 {
 105         ASSERT3U(zfs_uio_rw(uio), ==, dir);
 106         return (vn_io_fault_uiomove(p, n, GET_UIO_STRUCT(uio)));
 107 }