xref: /freebsd/lib/libufs/block.c (revision a2b560cc69eb254c92caf2027a69cadf9865d273)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
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 #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/extattr.h>
38 #include <ufs/ufs/quota.h>
39 #include <ufs/ufs/ufsmount.h>
40 #include <ufs/ufs/dinode.h>
41 #include <ufs/ffs/fs.h>
42 
43 #include <errno.h>
44 #include <fcntl.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <unistd.h>
49 
50 #include <libufs.h>
51 
52 ssize_t
53 bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
54 {
55 	void *p2;
56 	ssize_t cnt;
57 
58 	ERROR(disk, NULL);
59 
60 	BUF_MALLOC(&p2, data, size);
61 	if (p2 == NULL) {
62 		ERROR(disk, "allocate bounce buffer");
63 		goto fail;
64 	}
65 	cnt = pread(disk->d_fd, p2, size, (off_t)(blockno * disk->d_bsize));
66 	if (cnt == -1) {
67 		ERROR(disk, "read error from block device");
68 		goto fail;
69 	}
70 	if (cnt == 0) {
71 		ERROR(disk, "end of file from block device");
72 		goto fail;
73 	}
74 	if ((size_t)cnt != size) {
75 		ERROR(disk, "short read or read error from block device");
76 		goto fail;
77 	}
78 	if (p2 != data) {
79 		memcpy(data, p2, size);
80 		free(p2);
81 	}
82 	return (cnt);
83 fail:	memset(data, 0, size);
84 	if (p2 != data) {
85 		free(p2);
86 	}
87 	return (-1);
88 }
89 
90 ssize_t
91 bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
92 {
93 	ssize_t cnt;
94 	int rv;
95 	void *p2;
96 
97 	ERROR(disk, NULL);
98 
99 	rv = ufs_disk_write(disk);
100 	if (rv == -1) {
101 		ERROR(disk, "failed to open disk for writing");
102 		return (-1);
103 	}
104 	BUF_MALLOC(&p2, data, size);
105 	if (p2 == NULL) {
106 		ERROR(disk, "allocate bounce buffer");
107 		return (-1);
108 	}
109 	if (p2 != data)
110 		memcpy(p2, data, size);
111 	cnt = pwrite(disk->d_fd, p2, size, (off_t)(blockno * disk->d_bsize));
112 	if (p2 != data)
113 		free(p2);
114 	if (cnt == -1) {
115 		ERROR(disk, "write error to block device");
116 		return (-1);
117 	}
118 	if ((size_t)cnt != size) {
119 		ERROR(disk, "short write to block device");
120 		return (-1);
121 	}
122 	return (cnt);
123 }
124 
125 #ifdef __FreeBSD_kernel__
126 
127 static int
128 berase_helper(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
129 {
130 	off_t ioarg[2];
131 
132 	ioarg[0] = blockno * disk->d_bsize;
133 	ioarg[1] = size;
134 	return (ioctl(disk->d_fd, DIOCGDELETE, ioarg));
135 }
136 
137 #else
138 
139 static int
140 berase_helper(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
141 {
142 	char *zero_chunk;
143 	off_t offset, zero_chunk_size, pwrite_size;
144 	int rv;
145 
146 	offset = blockno * disk->d_bsize;
147 	zero_chunk_size = 65536 * disk->d_bsize;
148 	zero_chunk = calloc(1, zero_chunk_size);
149 	if (zero_chunk == NULL) {
150 		ERROR(disk, "failed to allocate memory");
151 		return (-1);
152 	}
153 	while (size > 0) {
154 		pwrite_size = size;
155 		if (pwrite_size > zero_chunk_size)
156 			pwrite_size = zero_chunk_size;
157 		rv = pwrite(disk->d_fd, zero_chunk, pwrite_size, offset);
158 		if (rv == -1) {
159 			ERROR(disk, "failed writing to disk");
160 			break;
161 		}
162 		size -= rv;
163 		offset += rv;
164 		rv = 0;
165 	}
166 	free(zero_chunk);
167 	return (rv);
168 }
169 
170 #endif
171 
172 int
173 berase(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
174 {
175 	int rv;
176 
177 	ERROR(disk, NULL);
178 	rv = ufs_disk_write(disk);
179 	if (rv == -1) {
180 		ERROR(disk, "failed to open disk for writing");
181 		return(rv);
182 	}
183 	return (berase_helper(disk, blockno, size));
184 }
185