bsd/isofs/cd9660/cd9660_bmap.c

   1 /*
   2  * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. The rights granted to you under the License
  10  * may not be used to create, or enable the creation or redistribution of,
  11  * unlawful or unlicensed copies of an Apple operating system, or to
  12  * circumvent, violate, or enable the circumvention or violation of, any
  13  * terms of an Apple operating system software license agreement.
  14  *
  15  * Please obtain a copy of the License at
  16  * http://www.opensource.apple.com/apsl/ and read it before using this file.
  17  *
  18  * The Original Code and all software distributed under the License are
  19  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  20  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  21  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  22  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  23  * Please see the License for the specific language governing rights and
  24  * limitations under the License.
  25  *
  26  * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
  27  */
  28 /*      $NetBSD: cd9660_bmap.c,v 1.5 1994/12/13 22:33:12 mycroft Exp $  */
  29
  30 /*-
  31  * Copyright (c) 1994
  32  *      The Regents of the University of California.  All rights reserved.
  33  *
  34  * This code is derived from software contributed to Berkeley
  35  * by Pace Willisson (pace@blitz.com).  The Rock Ridge Extension
  36  * Support code is derived from software contributed to Berkeley
  37  * by Atsushi Murai (amurai@spec.co.jp).
  38  *
  39  * Redistribution and use in source and binary forms, with or without
  40  * modification, are permitted provided that the following conditions
  41  * are met:
  42  * 1. Redistributions of source code must retain the above copyright
  43  *    notice, this list of conditions and the following disclaimer.
  44  * 2. Redistributions in binary form must reproduce the above copyright
  45  *    notice, this list of conditions and the following disclaimer in the
  46  *    documentation and/or other materials provided with the distribution.
  47  * 3. All advertising materials mentioning features or use of this software
  48  *    must display the following acknowledgement:
  49  *      This product includes software developed by the University of
  50  *      California, Berkeley and its contributors.
  51  * 4. Neither the name of the University nor the names of its contributors
  52  *    may be used to endorse or promote products derived from this software
  53  *    without specific prior written permission.
  54  *
  55  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  56  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  57  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  58  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  59  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  60  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  61  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  62  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  63  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  64  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  65  * SUCH DAMAGE.
  66  *
  67  *      @(#)cd9660_bmap.c       8.4 (Berkeley) 12/5/94
  68  */
  69
  70 #include <sys/param.h>
  71 #include <sys/vnode.h>
  72 #include <sys/mount.h>
  73 #include <sys/namei.h>
  74 #include <sys/file.h>
  75
  76 #include <isofs/cd9660/iso.h>
  77 #include <isofs/cd9660/cd9660_node.h>
  78
  79
  80 /* blktooff converts a logical block number to a file offset */
  81 int
  82 cd9660_blktooff(struct vnop_blktooff_args *ap)
  83 {
  84         register struct iso_node *ip;
  85         register struct iso_mnt *imp;
  86
  87         if (ap->a_vp == NULL)
  88                 return (EINVAL);
  89
  90         ip = VTOI(ap->a_vp);
  91         imp = ip->i_mnt;
  92
  93         *ap->a_offset = (off_t)lblktosize(imp, ap->a_lblkno);
  94         return (0);
  95 }
  96
  97 /* offtoblk converts a file offset to a logical block number */
  98 int
  99 cd9660_offtoblk(struct vnop_offtoblk_args *ap)
 100 {
 101         register struct iso_node *ip;
 102         register struct iso_mnt *imp;
 103
 104         if (ap->a_vp == NULL)
 105                 return (EINVAL);
 106
 107         ip = VTOI(ap->a_vp);
 108         imp = ip->i_mnt;
 109
 110         *ap->a_lblkno = (daddr64_t)lblkno(imp, ap->a_offset);
 111         return (0);
 112 }
 113
 114 int
 115 cd9660_blockmap(struct vnop_blockmap_args *ap)
 116 {
 117         struct iso_node *ip = VTOI(ap->a_vp);
 118         size_t cbytes;
 119         int devBlockSize = 0;
 120         off_t offset = ap->a_foffset;
 121
 122         /*
 123          * Check for underlying vnode requests and ensure that logical
 124          * to physical mapping is requested.
 125          */
 126         if (ap->a_bpn == NULL)
 127                 return (0);
 128
 129         devBlockSize = vfs_devblocksize(vnode_mount(ap->a_vp));
 130
 131         /*
 132          * Associated files have an Apple Double header
 133          */
 134         if (ip->i_flag & ISO_ASSOCIATED) {
 135                 if (offset < ADH_SIZE) {
 136                         if (ap->a_run)
 137                                 *ap->a_run = 0;
 138                         *ap->a_bpn = (daddr64_t)-1;
 139                         goto out;
 140                 } else {
 141                         offset -= ADH_SIZE;
 142                 }
 143         }
 144
 145         *ap->a_bpn = (daddr64_t)(ip->iso_start + lblkno(ip->i_mnt, offset));
 146
 147         /*
 148          * Determine maximum number of contiguous bytes following the
 149          * requested offset.
 150          */
 151         if (ap->a_run) {
 152                 if (ip->i_size > offset)
 153                         cbytes = ip->i_size - offset;
 154                 else
 155                         cbytes = 0;
 156
 157                 cbytes = (cbytes + (devBlockSize - 1)) & ~(devBlockSize - 1);
 158
 159                 *ap->a_run = MIN(cbytes, ap->a_size);
 160         };
 161 out:
 162         if (ap->a_poff)
 163                 *(int *)ap->a_poff = (long)offset & (devBlockSize - 1);
 164
 165         return (0);
 166 }
 167