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 37 #include <sys/param.h> 38 #include <sys/systm.h> 39 #include <sys/vnode.h> 40 #include <sys/mount.h> 41 42 #include <fs/cd9660/iso.h> 43 #include <fs/cd9660/cd9660_node.h> 44 45 /* 46 * Bmap converts the logical block number of a file to its physical 47 * block number on the disk. The conversion is done by using the 48 * logical block number to index into the data block (extent) for the 49 * file. 50 */ 51 int 52 cd9660_bmap(struct vop_bmap_args *ap) 53 { 54 struct iso_node *ip = VTOI(ap->a_vp); 55 daddr_t lblkno = ap->a_bn; 56 int bshift; 57 58 /* 59 * Check for underlying vnode requests and ensure that logical 60 * to physical mapping is requested. 61 */ 62 if (ap->a_bop != NULL) 63 *ap->a_bop = &ip->i_mnt->im_devvp->v_bufobj; 64 if (ap->a_bnp == NULL) 65 return (0); 66 67 /* 68 * Compute the requested block number 69 */ 70 bshift = ip->i_mnt->im_bshift; 71 *ap->a_bnp = (ip->iso_start + lblkno) << (bshift - DEV_BSHIFT); 72 73 /* 74 * Determine maximum number of readahead blocks following the 75 * requested block. 76 */ 77 if (ap->a_runp) { 78 int nblk; 79 80 nblk = (ip->i_size >> bshift) - (lblkno + 1); 81 if (nblk <= 0) 82 *ap->a_runp = 0; 83 else if (nblk >= (MAXBSIZE >> bshift)) 84 *ap->a_runp = (MAXBSIZE >> bshift) - 1; 85 else 86 *ap->a_runp = nblk; 87 } 88 89 if (ap->a_runb) { 90 *ap->a_runb = 0; 91 } 92 93 return 0; 94 } 95