From 8fb65ce818b3e3c6f165b583b910af24000768a5 Mon Sep 17 00:00:00 2001 From: rgrimes Date: Tue, 24 May 1994 10:09:53 +0000 Subject: BSD 4.4 Lite Kernel Sources --- sys/isofs/cd9660/cd9660_bmap.c | 102 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 102 insertions(+) create mode 100644 sys/isofs/cd9660/cd9660_bmap.c (limited to 'sys/isofs/cd9660/cd9660_bmap.c') diff --git a/sys/isofs/cd9660/cd9660_bmap.c b/sys/isofs/cd9660/cd9660_bmap.c new file mode 100644 index 0000000..911eedf --- /dev/null +++ b/sys/isofs/cd9660/cd9660_bmap.c @@ -0,0 +1,102 @@ +/*- + * Copyright (c) 1994 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley + * by Pace Willisson (pace@blitz.com). The Rock Ridge Extension + * Support code is derived from software contributed to Berkeley + * by Atsushi Murai (amurai@spec.co.jp). + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. All advertising materials mentioning features or use of this software + * must display the following acknowledgement: + * This product includes software developed by the University of + * California, Berkeley and its contributors. + * 4. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * @(#)cd9660_bmap.c 8.3 (Berkeley) 1/23/94 + */ + +#include +#include +#include +#include +#include +#include + +#include +#include + +/* + * Bmap converts a the logical block number of a file to its physical block + * number on the disk. The conversion is done by using the logical block + * number to index into the data block (extent) for the file. + */ +int +cd9660_bmap(ap) + struct vop_bmap_args /* { + struct vnode *a_vp; + daddr_t a_bn; + struct vnode **a_vpp; + daddr_t *a_bnp; + int *a_runp; + } */ *ap; +{ + struct iso_node *ip = VTOI(ap->a_vp); + daddr_t lblkno = ap->a_bn; + long bsize; + + /* + * Check for underlying vnode requests and ensure that logical + * to physical mapping is requested. + */ + if (ap->a_vpp != NULL) + *ap->a_vpp = ip->i_devvp; + if (ap->a_bnp == NULL) + return (0); + + /* + * Compute the requested block number + */ + bsize = ip->i_mnt->logical_block_size; + *ap->a_bnp = (ip->iso_start + lblkno) * btodb(bsize); + + /* + * Determine maximum number of readahead blocks following the + * requested block. + */ + if (ap->a_runp) { + int nblk; + + nblk = (ip->i_size - (lblkno + 1) * bsize) / bsize; + if (nblk <= 0) + *ap->a_runp = 0; + else if (nblk >= MAXBSIZE/bsize) + *ap->a_runp = MAXBSIZE/bsize - 1; + else + *ap->a_runp = nblk; + } + + return 0; +} -- cgit v1.1