xref: /freebsd/lib/libufs/block.c (revision 2be1a816b9ff69588e55be0a84cbe2a31efc0f2f)
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 	}
70 	cnt = pread(disk->d_fd, p2, size, (off_t)(blockno * disk->d_bsize));
71 	if (cnt == -1) {
72 		ERROR(disk, "read error from block device");
73 		goto fail;
74 	}
75 	if (cnt == 0) {
76 		ERROR(disk, "end of file from block device");
77 		goto fail;
78 	}
79 	if ((size_t)cnt != size) {
80 		ERROR(disk, "short read or read error from block device");
81 		goto fail;
82 	}
83 	if (p2 != data) {
84 		memcpy(data, p2, size);
85 		free(p2);
86 	}
87 	return (cnt);
88 fail:	memset(data, 0, size);
89 	if (p2 != data) {
90 		free(p2);
91 	}
92 	return (-1);
93 }
94 
95 ssize_t
96 bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
97 {
98 	ssize_t cnt;
99 	int rv;
100 	void *p2 = NULL;
101 
102 	ERROR(disk, NULL);
103 
104 	rv = ufs_disk_write(disk);
105 	if (rv == -1) {
106 		ERROR(disk, "failed to open disk for writing");
107 		return (-1);
108 	}
109 
110 	/*
111 	 * XXX: various disk controllers require alignment of our buffer
112 	 * XXX: which is stricter than struct alignment.
113 	 * XXX: Bounce the buffer if not 64 byte aligned.
114 	 * XXX: this can be removed if/when the kernel is fixed
115 	 */
116 	if (((intptr_t)data) & 0x3f) {
117 		p2 = malloc(size);
118 		if (p2 == NULL)
119 			ERROR(disk, "allocate bounce buffer");
120 		memcpy(p2, data, size);
121 		data = p2;
122 	}
123 	cnt = pwrite(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
124 	if (p2 != NULL)
125 		free(p2);
126 	if (cnt == -1) {
127 		ERROR(disk, "write error to block device");
128 		return (-1);
129 	}
130 	if ((size_t)cnt != size) {
131 		ERROR(disk, "short write to block device");
132 		return (-1);
133 	}
134 
135 	return (cnt);
136 }
137 
138 int
139 berase(struct uufsd *disk, ufs2_daddr_t blockno, ufs2_daddr_t size)
140 {
141 	off_t ioarg[2];
142 	int rv;
143 
144 	ERROR(disk, NULL);
145 	rv = ufs_disk_write(disk);
146 	if (rv == -1) {
147 		ERROR(disk, "failed to open disk for writing");
148 		return(rv);
149 	}
150 	ioarg[0] = blockno * disk->d_bsize;
151 	ioarg[1] = size;
152 	rv = ioctl(disk->d_fd, DIOCGDELETE, ioarg);
153 	return (rv);
154 }
155