bsd/isofs/cd9660/cd9660_bmap.c

   1 /*
   2  * Copyright (c) 2000-2003 Apple Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * The contents of this file constitute Original Code as defined in and
   7  * are subject to the Apple Public Source License Version 1.1 (the
   8  * "License").  You may not use this file except in compliance with the
   9  * License.  Please obtain a copy of the License at
  10  * http://www.apple.com/publicsource and read it before using this file.
  11  *
  12  * This Original Code and all software distributed under the License are
  13  * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  14  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  15  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  16  * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
  17  * License for the specific language governing rights and limitations
  18  * under the License.
  19  *
  20  * @APPLE_LICENSE_HEADER_END@
  21  */
  22 /*      $NetBSD: cd9660_bmap.c,v 1.5 1994/12/13 22:33:12 mycroft Exp $  */
  23
  24 /*-
  25  * Copyright (c) 1994
  26  *      The Regents of the University of California.  All rights reserved.
  27  *
  28  * This code is derived from software contributed to Berkeley
  29  * by Pace Willisson (pace@blitz.com).  The Rock Ridge Extension
  30  * Support code is derived from software contributed to Berkeley
  31  * by Atsushi Murai (amurai@spec.co.jp).
  32  *
  33  * Redistribution and use in source and binary forms, with or without
  34  * modification, are permitted provided that the following conditions
  35  * are met:
  36  * 1. Redistributions of source code must retain the above copyright
  37  *    notice, this list of conditions and the following disclaimer.
  38  * 2. Redistributions in binary form must reproduce the above copyright
  39  *    notice, this list of conditions and the following disclaimer in the
  40  *    documentation and/or other materials provided with the distribution.
  41  * 3. All advertising materials mentioning features or use of this software
  42  *    must display the following acknowledgement:
  43  *      This product includes software developed by the University of
  44  *      California, Berkeley and its contributors.
  45  * 4. Neither the name of the University nor the names of its contributors
  46  *    may be used to endorse or promote products derived from this software
  47  *    without specific prior written permission.
  48  *
  49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  59  * SUCH DAMAGE.
  60  *
  61  *      @(#)cd9660_bmap.c       8.4 (Berkeley) 12/5/94
  62  */
  63
  64 #include <sys/param.h>
  65 #include <sys/vnode.h>
  66 #include <sys/mount.h>
  67 #include <sys/namei.h>
  68 #include <sys/file.h>
  69
  70 #include <isofs/cd9660/iso.h>
  71 #include <isofs/cd9660/cd9660_node.h>
  72
  73
  74 /* blktooff converts a logical block number to a file offset */
  75 int
  76 cd9660_blktooff(struct vnop_blktooff_args *ap)
  77 {
  78         register struct iso_node *ip;
  79         register struct iso_mnt *imp;
  80
  81         if (ap->a_vp == NULL)
  82                 return (EINVAL);
  83
  84         ip = VTOI(ap->a_vp);
  85         imp = ip->i_mnt;
  86
  87         *ap->a_offset = (off_t)lblktosize(imp, ap->a_lblkno);
  88         return (0);
  89 }
  90
  91 /* offtoblk converts a file offset to a logical block number */
  92 int
  93 cd9660_offtoblk(struct vnop_offtoblk_args *ap)
  94 {
  95         register struct iso_node *ip;
  96         register struct iso_mnt *imp;
  97
  98         if (ap->a_vp == NULL)
  99                 return (EINVAL);
 100
 101         ip = VTOI(ap->a_vp);
 102         imp = ip->i_mnt;
 103
 104         *ap->a_lblkno = (daddr64_t)lblkno(imp, ap->a_offset);
 105         return (0);
 106 }
 107
 108 int
 109 cd9660_blockmap(struct vnop_blockmap_args *ap)
 110 {
 111         struct iso_node *ip = VTOI(ap->a_vp);
 112         size_t cbytes;
 113         int devBlockSize = 0;
 114         off_t offset = ap->a_foffset;
 115
 116         /*
 117          * Check for underlying vnode requests and ensure that logical
 118          * to physical mapping is requested.
 119          */
 120         if (ap->a_bpn == NULL)
 121                 return (0);
 122
 123         devBlockSize = vfs_devblocksize(vnode_mount(ap->a_vp));
 124
 125         /*
 126          * Associated files have an Apple Double header
 127          */
 128         if (ip->i_flag & ISO_ASSOCIATED) {
 129                 if (offset < ADH_SIZE) {
 130                         if (ap->a_run)
 131                                 *ap->a_run = 0;
 132                         *ap->a_bpn = (daddr64_t)-1;
 133                         goto out;
 134                 } else {
 135                         offset -= ADH_SIZE;
 136                 }
 137         }
 138
 139         *ap->a_bpn = (daddr64_t)(ip->iso_start + lblkno(ip->i_mnt, offset));
 140
 141         /*
 142          * Determine maximum number of contiguous bytes following the
 143          * requested offset.
 144          */
 145         if (ap->a_run) {
 146                 if (ip->i_size > offset)
 147                         cbytes = ip->i_size - offset;
 148                 else
 149                         cbytes = 0;
 150
 151                 cbytes = (cbytes + (devBlockSize - 1)) & ~(devBlockSize - 1);
 152
 153                 *ap->a_run = MIN(cbytes, ap->a_size);
 154         };
 155 out:
 156         if (ap->a_poff)
 157                 *(int *)ap->a_poff = (long)offset & (devBlockSize - 1);
 158
 159         return (0);
 160 }
 161