xref: /freebsd/lib/libufs/block.c (revision dd41de95a84d979615a2ef11df6850622bf6184e)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2002 Juli Mallett.  All rights reserved.
5  *
6  * This software was written by Juli Mallett <jmallett@FreeBSD.org> for the
7  * FreeBSD project.  Redistribution and use in source and binary forms, with
8  * or without modification, are permitted provided that the following
9  * conditions are met:
10  *
11  * 1. Redistribution of source code must retain the above copyright notice,
12  *    this list of conditions and the following disclaimer.
13  * 2. Redistribution in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
20  * DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT,
21  * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
23  * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
25  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
26  * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  * POSSIBILITY OF SUCH DAMAGE.
28  */
29 
30 #include <sys/cdefs.h>
31 __FBSDID("$FreeBSD$");
32 
33 #include <sys/param.h>
34 #include <sys/mount.h>
35 #include <sys/disk.h>
36 #include <sys/disklabel.h>
37 #include <sys/stat.h>
38 
39 #include <ufs/ufs/extattr.h>
40 #include <ufs/ufs/quota.h>
41 #include <ufs/ufs/ufsmount.h>
42 #include <ufs/ufs/dinode.h>
43 #include <ufs/ffs/fs.h>
44 
45 #include <errno.h>
46 #include <fcntl.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50 #include <unistd.h>
51 
52 #include <libufs.h>
53 
54 ssize_t
55 bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
56 {
57 	void *p2;
58 	ssize_t cnt;
59 
60 	ERROR(disk, NULL);
61 
62 	p2 = data;
63 	/*
64 	 * XXX: various disk controllers require alignment of our buffer
65 	 * XXX: which is stricter than struct alignment.
66 	 * XXX: Bounce the buffer if not 64 byte aligned.
67 	 * XXX: this can be removed if/when the kernel is fixed
68 	 */
69 	if (((intptr_t)data) & 0x3f) {
70 		p2 = malloc(size);
71 		if (p2 == NULL) {
72 			ERROR(disk, "allocate bounce buffer");
73 			goto fail;
74 		}
75 	}
76 	cnt = pread(disk->d_fd, p2, size, (off_t)(blockno * disk->d_bsize));
77 	if (cnt == -1) {
78 		ERROR(disk, "read error from block device");
79 		goto fail;
80 	}
81 	if (cnt == 0) {
82 		ERROR(disk, "end of file from block device");
83 		goto fail;
84 	}
85 	if ((size_t)cnt != size) {
86 		ERROR(disk, "short read or read error from block device");
87 		goto fail;
88 	}
89 	if (p2 != data) {
90 		memcpy(data, p2, size);
91 		free(p2);
92 	}
93 	return (cnt);
94 fail:	memset(data, 0, size);
95 	if (p2 != data) {
96 		free(p2);
97 	}
98 	return (-1);
99 }
100 
101 ssize_t
102 bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
103 {
104 	ssize_t cnt;
105 	int rv;
106 	void *p2 = NULL;
107 
108 	ERROR(disk, NULL);
109 
110 	rv = ufs_disk_write(disk);
111 	if (rv == -1) {
112 		ERROR(disk, "failed to open disk for writing");
113 		return (-1);
114 	}
115 
116 	/*
117 	 * XXX: various disk controllers require alignment of our buffer
118 	 * XXX: which is stricter than struct alignment.
119 	 * XXX: Bounce the buffer if not 64 byte aligned.
120 	 * XXX: this can be removed if/when the kernel is fixed
121 	 */
122 	if (((intptr_t)data) & 0x3f) {
123 		p2 = malloc(size);
124 		if (p2 == NULL) {
125 			ERROR(disk, "allocate bounce buffer");
126 			return (-1);
127 		}
128 		memcpy(p2, data, size);
129 		data = p2;
130 	}
131 	cnt = pwrite(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
132 	if (p2 != NULL)
133 		free(p2);
134 	if (cnt == -1) {
135 		ERROR(disk, "write error to block device");
136 		return (-1);
137 	}
138 	if ((size_t)cnt != size) {
139 		ERROR(disk, "short write to block device");
140 		return (-1);
141 	}
142 
143 	return (cnt);
144 }
145 
146 #ifdef __FreeBSD_kernel__
147 
148 static int
149 berase_helper(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
150 {
151 	off_t ioarg[2];
152 
153 	ioarg[0] = blockno * disk->d_bsize;
154 	ioarg[1] = size;
155 	return (ioctl(disk->d_fd, DIOCGDELETE, ioarg));
156 }
157 
158 #else
159 
160 static int
161 berase_helper(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
162 {
163 	char *zero_chunk;
164 	off_t offset, zero_chunk_size, pwrite_size;
165 	int rv;
166 
167 	offset = blockno * disk->d_bsize;
168 	zero_chunk_size = 65536 * disk->d_bsize;
169 	zero_chunk = calloc(1, zero_chunk_size);
170 	if (zero_chunk == NULL) {
171 		ERROR(disk, "failed to allocate memory");
172 		return (-1);
173 	}
174 	while (size > 0) {
175 		pwrite_size = size;
176 		if (pwrite_size > zero_chunk_size)
177 			pwrite_size = zero_chunk_size;
178 		rv = pwrite(disk->d_fd, zero_chunk, pwrite_size, offset);
179 		if (rv == -1) {
180 			ERROR(disk, "failed writing to disk");
181 			break;
182 		}
183 		size -= rv;
184 		offset += rv;
185 		rv = 0;
186 	}
187 	free(zero_chunk);
188 	return (rv);
189 }
190 
191 #endif
192 
193 int
194 berase(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
195 {
196 	int rv;
197 
198 	ERROR(disk, NULL);
199 	rv = ufs_disk_write(disk);
200 	if (rv == -1) {
201 		ERROR(disk, "failed to open disk for writing");
202 		return(rv);
203 	}
204 	return (berase_helper(disk, blockno, size));
205 }
206