1 /*- 2 * SPDX-License-Identifier: BSD-3-Clause 3 * 4 * Copyright (c) 1994 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This code is derived from software contributed to Berkeley 8 * by Pace Willisson (pace@blitz.com). The Rock Ridge Extension 9 * Support code is derived from software contributed to Berkeley 10 * by Atsushi Murai (amurai@spec.co.jp). 11 * 12 * Redistribution and use in source and binary forms, with or without 13 * modification, are permitted provided that the following conditions 14 * are met: 15 * 1. Redistributions of source code must retain the above copyright 16 * notice, this list of conditions and the following disclaimer. 17 * 2. Redistributions in binary form must reproduce the above copyright 18 * notice, this list of conditions and the following disclaimer in the 19 * documentation and/or other materials provided with the distribution. 20 * 3. Neither the name of the University nor the names of its contributors 21 * may be used to endorse or promote products derived from this software 22 * without specific prior written permission. 23 * 24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 34 * SUCH DAMAGE. 35 * 36 * @(#)cd9660_bmap.c 8.3 (Berkeley) 1/23/94 37 */ 38 39 #include <sys/cdefs.h> 40 __FBSDID("$FreeBSD$"); 41 42 #include <sys/param.h> 43 #include <sys/systm.h> 44 #include <sys/vnode.h> 45 #include <sys/mount.h> 46 47 #include <fs/cd9660/iso.h> 48 #include <fs/cd9660/cd9660_node.h> 49 50 /* 51 * Bmap converts the logical block number of a file to its physical 52 * block number on the disk. The conversion is done by using the 53 * logical block number to index into the data block (extent) for the 54 * file. 55 */ 56 int 57 cd9660_bmap(ap) 58 struct vop_bmap_args /* { 59 struct vnode *a_vp; 60 daddr_t a_bn; 61 struct bufobj **a_bop; 62 daddr_t *a_bnp; 63 int *a_runp; 64 int *a_runb; 65 } */ *ap; 66 { 67 struct iso_node *ip = VTOI(ap->a_vp); 68 daddr_t lblkno = ap->a_bn; 69 int bshift; 70 71 /* 72 * Check for underlying vnode requests and ensure that logical 73 * to physical mapping is requested. 74 */ 75 if (ap->a_bop != NULL) 76 *ap->a_bop = &ip->i_mnt->im_devvp->v_bufobj; 77 if (ap->a_bnp == NULL) 78 return (0); 79 80 /* 81 * Compute the requested block number 82 */ 83 bshift = ip->i_mnt->im_bshift; 84 *ap->a_bnp = (ip->iso_start + lblkno) << (bshift - DEV_BSHIFT); 85 86 /* 87 * Determine maximum number of readahead blocks following the 88 * requested block. 89 */ 90 if (ap->a_runp) { 91 int nblk; 92 93 nblk = (ip->i_size >> bshift) - (lblkno + 1); 94 if (nblk <= 0) 95 *ap->a_runp = 0; 96 else if (nblk >= (MAXBSIZE >> bshift)) 97 *ap->a_runp = (MAXBSIZE >> bshift) - 1; 98 else 99 *ap->a_runp = nblk; 100 } 101 102 if (ap->a_runb) { 103 *ap->a_runb = 0; 104 } 105 106 return 0; 107 } 108