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