block.c revision 120874 
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 120874 2003-10-07 07:12:22Z phk $");
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 <fcntl.h>
42#include <stdio.h>
43#include <stdlib.h>
44#include <string.h>
45#include <unistd.h>
46
47#include <libufs.h>
48
49ssize_t
50bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
51{
52	void *p2;
53	ssize_t cnt;
54
55	ERROR(disk, NULL);
56
57	p2 = data;
58	/*
59	 * XXX: various disk controllers require alignment of our buffer
60	 * XXX: which is stricter than struct alignment.
61	 * XXX: Bounce the buffer if not 64 byte aligned.
62	 * XXX: this can be removed if/when the kernel is fixed
63	 */
64	if (((intptr_t)data) & 0x3f) {
65		p2 = malloc(size);
66		if (p2 == NULL)
67			ERROR(disk, "allocate bounce buffer");
68	}
69	cnt = pread(disk->d_fd, p2, size, (off_t)(blockno * disk->d_bsize));
70	if (cnt == -1) {
71		ERROR(disk, "read error from block device");
72		goto fail;
73	}
74	if (cnt == 0) {
75		ERROR(disk, "end of file from block device");
76		goto fail;
77	}
78	if ((size_t)cnt != size) {
79		ERROR(disk, "short read or read error from block device");
80		goto fail;
81	}
82	if (p2 != data) {
83		memcpy(data, p2, size);
84		free(p2);
85	}
86	return (cnt);
87fail:	memset(data, 0, size);
88	if (p2 != data) {
89		free(p2);
90	}
91	return (-1);
92}
93
94ssize_t
95bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
96{
97	ssize_t cnt;
98	int rv;
99	void *p2 = NULL;
100
101	ERROR(disk, NULL);
102
103	rv = ufs_disk_write(disk);
104	if (rv == -1) {
105		ERROR(disk, "failed to open disk for writing");
106		return (-1);
107	}
108
109	/*
110	 * XXX: various disk controllers require alignment of our buffer
111	 * XXX: which is stricter than struct alignment.
112	 * XXX: Bounce the buffer if not 64 byte aligned.
113	 * XXX: this can be removed if/when the kernel is fixed
114	 */
115	if (((intptr_t)data) & 0x3f) {
116		p2 = malloc(size);
117		if (p2 == NULL)
118			ERROR(disk, "allocate bounce buffer");
119		memcpy(p2, data, size);
120		data = p2;
121	}
122	cnt = pwrite(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
123	if (p2 != NULL)
124		free(p2);
125	if (cnt == -1) {
126		ERROR(disk, "write error to block device");
127		return (-1);
128	}
129	if ((size_t)cnt != size) {
130		ERROR(disk, "short write to block device");
131		return (-1);
132	}
133
134	return (cnt);
135}
136