Line data    Source code

       1             : /*      $OpenBSD: cd9660_bmap.c,v 1.9 2017/12/30 20:47:00 guenther Exp $        */
       2             : /*      $NetBSD: cd9660_bmap.c,v 1.7 1997/01/24 00:27:29 cgd Exp $      */
       3             : 
       4             : /*-
       5             :  * Copyright (c) 1994
       6             :  *      The Regents of the University of California.  All rights reserved.
       7             :  *
       8             :  * This code is derived from software contributed to Berkeley
       9             :  * by Pace Willisson (pace@blitz.com).  The Rock Ridge Extension
      10             :  * Support code is derived from software contributed to Berkeley
      11             :  * by Atsushi Murai (amurai@spec.co.jp).
      12             :  *
      13             :  * Redistribution and use in source and binary forms, with or without
      14             :  * modification, are permitted provided that the following conditions
      15             :  * are met:
      16             :  * 1. Redistributions of source code must retain the above copyright
      17             :  *    notice, this list of conditions and the following disclaimer.
      18             :  * 2. Redistributions in binary form must reproduce the above copyright
      19             :  *    notice, this list of conditions and the following disclaimer in the
      20             :  *    documentation and/or other materials provided with the distribution.
      21             :  * 3. Neither the name of the University nor the names of its contributors
      22             :  *    may be used to endorse or promote products derived from this software
      23             :  *    without specific prior written permission.
      24             :  *
      25             :  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
      26             :  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
      27             :  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
      28             :  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
      29             :  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
      30             :  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
      31             :  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
      32             :  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
      33             :  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
      34             :  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
      35             :  * SUCH DAMAGE.
      36             :  *
      37             :  *      @(#)cd9660_bmap.c       8.4 (Berkeley) 12/5/94
      38             :  */
      39             : 
      40             : #include <sys/param.h>
      41             : #include <sys/namei.h>
      42             : #include <sys/buf.h>
      43             : #include <sys/vnode.h>
      44             : #include <sys/lock.h>
      45             : #include <sys/mount.h>
      46             : 
      47             : #include <isofs/cd9660/iso.h>
      48             : #include <isofs/cd9660/cd9660_extern.h>
      49             : #include <isofs/cd9660/cd9660_node.h>
      50             : 
      51             : /*
      52             :  * Bmap converts a the logical block number of a file to its physical block
      53             :  * number on the disk. The conversion is done by using the logical block
      54             :  * number to index into the data block (extent) for the file.
      55             :  */
      56             : int
      57           0 : cd9660_bmap(v)
      58             :         void *v;
      59             : {
      60           0 :         struct vop_bmap_args *ap = v;
      61           0 :         struct iso_node *ip = VTOI(ap->a_vp);
      62           0 :         daddr_t lblkno = ap->a_bn;
      63             :         int bshift;
      64             : 
      65             :         /*
      66             :          * Check for underlying vnode requests and ensure that logical
      67             :          * to physical mapping is requested.
      68             :          */
      69           0 :         if (ap->a_vpp != NULL)
      70           0 :                 *ap->a_vpp = ip->i_devvp;
      71           0 :         if (ap->a_bnp == NULL)
      72           0 :                 return (0);
      73             : 
      74             :         /*
      75             :          * Compute the requested block number
      76             :          */
      77           0 :         bshift = ip->i_mnt->im_bshift;
      78           0 :         *ap->a_bnp = (ip->iso_start + lblkno) << (bshift - DEV_BSHIFT);
      79             : 
      80             :         /*
      81             :          * Determine maximum number of readahead blocks following the
      82             :          * requested block.
      83             :          */
      84           0 :         if (ap->a_runp) {
      85             :                 int nblk;
      86             : 
      87           0 :                 nblk = (ip->i_size >> bshift) - (lblkno + 1);
      88           0 :                 if (nblk <= 0)
      89           0 :                         *ap->a_runp = 0;
      90           0 :                 else if (nblk >= (MAXBSIZE >> bshift))
      91           0 :                         *ap->a_runp = (MAXBSIZE >> bshift) - 1;
      92             :                 else
      93           0 :                         *ap->a_runp = nblk;
      94           0 :         }
      95             : 
      96           0 :         return (0);
      97           0 : }