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
cd9660_bmap(struct vop_bmap_args * ap)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