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