summaryrefslogtreecommitdiffstats
path: root/lib/libufs/block.c
blob: c4ff3048270743b585296708b19518b73c6f37c8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
/*
 * Copyright (c) 2002 Juli Mallett.  All rights reserved.
 *
 * This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
 * FreeBSD project.  Redistribution and use in source and binary forms, with
 * or without modification, are permitted provided that the following
 * conditions are met:
 *
 * 1. Redistribution of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistribution 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.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include <sys/param.h>
#include <sys/mount.h>
#include <sys/disklabel.h>
#include <sys/stat.h>

#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/dinode.h>
#include <ufs/ffs/fs.h>

#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <libufs.h>

ssize_t
bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
{
	void *p2;
	ssize_t cnt;

	ERROR(disk, NULL);

	p2 = data;
	/*
	 * XXX: various disk controllers require alignment of our buffer
	 * XXX: which is stricter than struct alignment.
	 * XXX: Bounce the buffer if not 64 byte aligned.
	 * XXX: this can be removed if/when the kernel is fixed
	 */
	if (((intptr_t)data) & 0x3f) {
		p2 = malloc(size);
		if (p2 == NULL)
			ERROR(disk, "allocate bounce buffer");
	}
	cnt = pread(disk->d_fd, p2, size, (off_t)(blockno * disk->d_bsize));
	if (cnt == -1) {
		ERROR(disk, "read error from block device");
		goto fail;
	}
	if (cnt == 0) {
		ERROR(disk, "end of file from block device");
		goto fail;
	}
	if ((size_t)cnt != size) {
		ERROR(disk, "short read or read error from block device");
		goto fail;
	}
	if (p2 != data) {
		memcpy(data, p2, size);
		free(p2);
	}
	return (cnt);
fail:	memset(data, 0, size);
	if (p2 != data) {
		free(p2);
	}
	return (-1);
}

ssize_t
bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
{
	ssize_t cnt;
	int rv;
	void *p2 = NULL;

	ERROR(disk, NULL);

	rv = ufs_disk_write(disk);
	if (rv == -1) {
		ERROR(disk, "failed to open disk for writing");
		return (-1);
	}

	/*
	 * XXX: various disk controllers require alignment of our buffer
	 * XXX: which is stricter than struct alignment.
	 * XXX: Bounce the buffer if not 64 byte aligned.
	 * XXX: this can be removed if/when the kernel is fixed
	 */
	if (((intptr_t)data) & 0x3f) {
		p2 = malloc(size);
		if (p2 == NULL)
			ERROR(disk, "allocate bounce buffer");
		memcpy(p2, data, size);
		data = p2;
	}
	cnt = pwrite(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
	if (p2 != NULL)
		free(p2);
	if (cnt == -1) {
		ERROR(disk, "write error to block device");
		return (-1);
	}
	if ((size_t)cnt != size) {
		ERROR(disk, "short write to block device");
		return (-1);
	}

	return (cnt);
}
OpenPOWER on IntegriCloud