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      1  1.5   hannken /*	$NetBSD: cd9660_bmap.c,v 1.5 2014/06/14 07:39:28 hannken Exp $	*/
      2  1.1  jdolecek 
      3  1.1  jdolecek /*-
      4  1.1  jdolecek  * Copyright (c) 1994
      5  1.1  jdolecek  *	The Regents of the University of California.  All rights reserved.
      6  1.1  jdolecek  *
      7  1.1  jdolecek  * This code is derived from software contributed to Berkeley
      8  1.1  jdolecek  * by Pace Willisson (pace (at) blitz.com).  The Rock Ridge Extension
      9  1.1  jdolecek  * Support code is derived from software contributed to Berkeley
     10  1.1  jdolecek  * by Atsushi Murai (amurai (at) spec.co.jp).
     11  1.1  jdolecek  *
     12  1.1  jdolecek  * Redistribution and use in source and binary forms, with or without
     13  1.1  jdolecek  * modification, are permitted provided that the following conditions
     14  1.1  jdolecek  * are met:
     15  1.1  jdolecek  * 1. Redistributions of source code must retain the above copyright
     16  1.1  jdolecek  *    notice, this list of conditions and the following disclaimer.
     17  1.1  jdolecek  * 2. Redistributions in binary form must reproduce the above copyright
     18  1.1  jdolecek  *    notice, this list of conditions and the following disclaimer in the
     19  1.1  jdolecek  *    documentation and/or other materials provided with the distribution.
     20  1.2       agc  * 3. Neither the name of the University nor the names of its contributors
     21  1.1  jdolecek  *    may be used to endorse or promote products derived from this software
     22  1.1  jdolecek  *    without specific prior written permission.
     23  1.1  jdolecek  *
     24  1.1  jdolecek  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     25  1.1  jdolecek  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     26  1.1  jdolecek  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     27  1.1  jdolecek  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     28  1.1  jdolecek  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     29  1.1  jdolecek  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     30  1.1  jdolecek  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     31  1.1  jdolecek  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     32  1.1  jdolecek  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     33  1.1  jdolecek  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     34  1.1  jdolecek  * SUCH DAMAGE.
     35  1.1  jdolecek  *
     36  1.1  jdolecek  *	@(#)cd9660_bmap.c	8.4 (Berkeley) 12/5/94
     37  1.1  jdolecek  */
     38  1.1  jdolecek 
     39  1.1  jdolecek #include <sys/cdefs.h>
     40  1.5   hannken __KERNEL_RCSID(0, "$NetBSD: cd9660_bmap.c,v 1.5 2014/06/14 07:39:28 hannken Exp $");
     41  1.1  jdolecek 
     42  1.1  jdolecek #include <sys/param.h>
     43  1.1  jdolecek #include <sys/namei.h>
     44  1.1  jdolecek #include <sys/buf.h>
     45  1.1  jdolecek #include <sys/file.h>
     46  1.1  jdolecek #include <sys/vnode.h>
     47  1.1  jdolecek #include <sys/mount.h>
     48  1.1  jdolecek 
     49  1.1  jdolecek #include <fs/cd9660/iso.h>
     50  1.1  jdolecek #include <fs/cd9660/cd9660_extern.h>
     51  1.1  jdolecek #include <fs/cd9660/cd9660_node.h>
     52  1.1  jdolecek 
     53  1.1  jdolecek /*
     54  1.1  jdolecek  * Bmap converts a the logical block number of a file to its physical block
     55  1.1  jdolecek  * number on the disk. The conversion is done by using the logical block
     56  1.1  jdolecek  * number to index into the data block (extent) for the file.
     57  1.1  jdolecek  */
     58  1.1  jdolecek int
     59  1.4      matt cd9660_bmap(void *v)
     60  1.1  jdolecek {
     61  1.1  jdolecek 	struct vop_bmap_args /* {
     62  1.1  jdolecek 		struct vnode *a_vp;
     63  1.1  jdolecek 		daddr_t  a_bn;
     64  1.1  jdolecek 		struct vnode **a_vpp;
     65  1.1  jdolecek 		daddr_t *a_bnp;
     66  1.1  jdolecek 		int *a_runp;
     67  1.1  jdolecek 	} */ *ap = v;
     68  1.1  jdolecek 	struct iso_node *ip = VTOI(ap->a_vp);
     69  1.1  jdolecek 	daddr_t lblkno = ap->a_bn;
     70  1.1  jdolecek 	int bshift;
     71  1.1  jdolecek 
     72  1.1  jdolecek 	/*
     73  1.1  jdolecek 	 * Check for underlying vnode requests and ensure that logical
     74  1.1  jdolecek 	 * to physical mapping is requested.
     75  1.1  jdolecek 	 */
     76  1.1  jdolecek 	if (ap->a_vpp != NULL)
     77  1.5   hannken 		*ap->a_vpp = ip->i_mnt->im_devvp;
     78  1.1  jdolecek 	if (ap->a_bnp == NULL)
     79  1.1  jdolecek 		return (0);
     80  1.1  jdolecek 
     81  1.1  jdolecek 	/*
     82  1.1  jdolecek 	 * Compute the requested block number
     83  1.1  jdolecek 	 */
     84  1.1  jdolecek 	bshift = ip->i_mnt->im_bshift;
     85  1.1  jdolecek 	*ap->a_bnp = (ip->iso_start + lblkno) << (bshift - DEV_BSHIFT);
     86  1.1  jdolecek 
     87  1.1  jdolecek 	/*
     88  1.1  jdolecek 	 * Determine maximum number of readahead blocks following the
     89  1.1  jdolecek 	 * requested block.
     90  1.1  jdolecek 	 */
     91  1.1  jdolecek 	if (ap->a_runp) {
     92  1.1  jdolecek 		int nblk;
     93  1.1  jdolecek 
     94  1.1  jdolecek 		nblk = (ip->i_size >> bshift) - (lblkno + 1);
     95  1.1  jdolecek 		if (nblk <= 0)
     96  1.1  jdolecek 			*ap->a_runp = 0;
     97  1.1  jdolecek 		else if (nblk >= (MAXBSIZE >> bshift))
     98  1.1  jdolecek 			*ap->a_runp = (MAXBSIZE >> bshift) - 1;
     99  1.1  jdolecek 		else
    100  1.1  jdolecek 			*ap->a_runp = nblk;
    101  1.1  jdolecek 	}
    102  1.1  jdolecek 
    103  1.1  jdolecek 	return (0);
    104  1.1  jdolecek }
    105