block.c revision 109462 
1/*
2 * Copyright (c) 2002 Juli Mallett.  All rights reserved.
3 *
4 * This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
5 * FreeBSD project.  Redistribution and use in source and binary forms, with
6 * or without modification, are permitted provided that the following
7 * conditions are met:
8 *
9 * 1. Redistribution of source code must retain the above copyright notice,
10 *    this list of conditions and the following disclaimer.
11 * 2. Redistribution in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
17 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
18 * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
19 * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
20 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
21 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
22 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
23 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
24 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25 * POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include <sys/cdefs.h>
29__FBSDID("$FreeBSD: head/lib/libufs/block.c 109462 2003-01-18 04:22:14Z jmallett $");
30
31#include <sys/param.h>
32#include <sys/mount.h>
33#include <sys/disklabel.h>
34#include <sys/stat.h>
35
36#include <ufs/ufs/ufsmount.h>
37#include <ufs/ufs/dinode.h>
38#include <ufs/ffs/fs.h>
39
40#include <errno.h>
41#include <stdio.h>
42#include <string.h>
43#include <unistd.h>
44
45#include <libufs.h>
46
47ssize_t
48bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
49{
50	char *buf;
51	ssize_t cnt;
52
53	ERROR(disk, NULL);
54
55	/*
56	 * For when we need to work with the data as a buffer.
57	 */
58	buf = data;
59
60	cnt = pread(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
61	/*
62	 * In case of failure, zero data, which must be fs_bsize.
63	 */
64	if (cnt != size) {
65		ERROR(disk, "short read from block device");
66		for (cnt = 0; cnt < disk->d_fs.fs_bsize; cnt++)
67			buf[cnt] = 0;
68		return -1;
69	}
70	return cnt;
71}
72
73ssize_t
74bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
75{
76	ssize_t cnt;
77
78	ERROR(disk, NULL);
79
80	cnt = pwrite(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
81	if (cnt != size) {
82		ERROR(disk, "short write to block device");
83		return -1;
84	}
85
86	return cnt;
87}
88