xref: /freebsd/lib/libufs/block.c (revision 6ae1554a5d9b318f8ad53ccc39fa5a961403da73)
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("$FreeBSD$");
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 
50 ssize_t
51 bread(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);
90 fail:	memset(data, 0, size);
91 	if (p2 != data) {
92 		free(p2);
93 	}
94 	return (-1);
95 }
96 
97 ssize_t
98 bwrite(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 
144 static int
145 berase_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 
156 static int
157 berase_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 
189 int
190 berase(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