block.c revision 331722 
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: stable/11/lib/libufs/block.c 331722 2018-03-29 02:50:57Z eadler $");
30
31#include <sys/param.h>
32#include <sys/mount.h>
33#include <sys/disk.h>
34#include <sys/disklabel.h>
35#include <sys/stat.h>
36
37#include <ufs/ufs/ufsmount.h>
38#include <ufs/ufs/dinode.h>
39#include <ufs/ffs/fs.h>
40
41#include <errno.h>
42#include <fcntl.h>
43#include <stdio.h>
44#include <stdlib.h>
45#include <string.h>
46#include <unistd.h>
47
48#include <libufs.h>
49
50ssize_t
51bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
52{
53	void *p2;
54	ssize_t cnt;
55
56	ERROR(disk, NULL);
57
58	p2 = data;
59	/*
60	 * XXX: various disk controllers require alignment of our buffer
61	 * XXX: which is stricter than struct alignment.
62	 * XXX: Bounce the buffer if not 64 byte aligned.
63	 * XXX: this can be removed if/when the kernel is fixed
64	 */
65	if (((intptr_t)data) & 0x3f) {
66		p2 = malloc(size);
67		if (p2 == NULL) {
68			ERROR(disk, "allocate bounce buffer");
69			goto fail;
70		}
71	}
72	cnt = pread(disk->d_fd, p2, size, (off_t)(blockno * disk->d_bsize));
73	if (cnt == -1) {
74		ERROR(disk, "read error from block device");
75		goto fail;
76	}
77	if (cnt == 0) {
78		ERROR(disk, "end of file from block device");
79		goto fail;
80	}
81	if ((size_t)cnt != size) {
82		ERROR(disk, "short read or read error from block device");
83		goto fail;
84	}
85	if (p2 != data) {
86		memcpy(data, p2, size);
87		free(p2);
88	}
89	return (cnt);
90fail:	memset(data, 0, size);
91	if (p2 != data) {
92		free(p2);
93	}
94	return (-1);
95}
96
97ssize_t
98bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
99{
100	ssize_t cnt;
101	int rv;
102	void *p2 = NULL;
103
104	ERROR(disk, NULL);
105
106	rv = ufs_disk_write(disk);
107	if (rv == -1) {
108		ERROR(disk, "failed to open disk for writing");
109		return (-1);
110	}
111
112	/*
113	 * XXX: various disk controllers require alignment of our buffer
114	 * XXX: which is stricter than struct alignment.
115	 * XXX: Bounce the buffer if not 64 byte aligned.
116	 * XXX: this can be removed if/when the kernel is fixed
117	 */
118	if (((intptr_t)data) & 0x3f) {
119		p2 = malloc(size);
120		if (p2 == NULL) {
121			ERROR(disk, "allocate bounce buffer");
122			return (-1);
123		}
124		memcpy(p2, data, size);
125		data = p2;
126	}
127	cnt = pwrite(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
128	if (p2 != NULL)
129		free(p2);
130	if (cnt == -1) {
131		ERROR(disk, "write error to block device");
132		return (-1);
133	}
134	if ((size_t)cnt != size) {
135		ERROR(disk, "short write to block device");
136		return (-1);
137	}
138
139	return (cnt);
140}
141
142#ifdef __FreeBSD_kernel__
143
144static int
145berase_helper(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
146{
147	off_t ioarg[2];
148
149	ioarg[0] = blockno * disk->d_bsize;
150	ioarg[1] = size;
151	return (ioctl(disk->d_fd, DIOCGDELETE, ioarg));
152}
153
154#else
155
156static int
157berase_helper(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
158{
159	char *zero_chunk;
160	off_t offset, zero_chunk_size, pwrite_size;
161	int rv;
162
163	offset = blockno * disk->d_bsize;
164	zero_chunk_size = 65536 * disk->d_bsize;
165	zero_chunk = calloc(1, zero_chunk_size);
166	if (zero_chunk == NULL) {
167		ERROR(disk, "failed to allocate memory");
168		return (-1);
169	}
170	while (size > 0) {
171		pwrite_size = size;
172		if (pwrite_size > zero_chunk_size)
173			pwrite_size = zero_chunk_size;
174		rv = pwrite(disk->d_fd, zero_chunk, pwrite_size, offset);
175		if (rv == -1) {
176			ERROR(disk, "failed writing to disk");
177			break;
178		}
179		size -= rv;
180		offset += rv;
181		rv = 0;
182	}
183	free(zero_chunk);
184	return (rv);
185}
186
187#endif
188
189int
190berase(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
191{
192	int rv;
193
194	ERROR(disk, NULL);
195	rv = ufs_disk_write(disk);
196	if (rv == -1) {
197		ERROR(disk, "failed to open disk for writing");
198		return(rv);
199	}
200	return (berase_helper(disk, blockno, size));
201}
202