xref: /freebsd/lib/libufs/block.c (revision f0a75d274af375d15b97b830966b99a02b7db911)
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/disklabel.h>
34 #include <sys/stat.h>
35 
36 #include <ufs/ufs/ufsmount.h>
37 #include <ufs/ufs/dinode.h>
38 #include <ufs/ffs/fs.h>
39 
40 #include <errno.h>
41 #include <fcntl.h>
42 #include <stdio.h>
43 #include <stdlib.h>
44 #include <string.h>
45 #include <unistd.h>
46 
47 #include <libufs.h>
48 
49 ssize_t
50 bread(struct uufsd *disk, ufs2_daddr_t blockno, void *data, size_t size)
51 {
52 	void *p2;
53 	ssize_t cnt;
54 
55 	ERROR(disk, NULL);
56 
57 	p2 = data;
58 	/*
59 	 * XXX: various disk controllers require alignment of our buffer
60 	 * XXX: which is stricter than struct alignment.
61 	 * XXX: Bounce the buffer if not 64 byte aligned.
62 	 * XXX: this can be removed if/when the kernel is fixed
63 	 */
64 	if (((intptr_t)data) & 0x3f) {
65 		p2 = malloc(size);
66 		if (p2 == NULL)
67 			ERROR(disk, "allocate bounce buffer");
68 	}
69 	cnt = pread(disk->d_fd, p2, size, (off_t)(blockno * disk->d_bsize));
70 	if (cnt == -1) {
71 		ERROR(disk, "read error from block device");
72 		goto fail;
73 	}
74 	if (cnt == 0) {
75 		ERROR(disk, "end of file from block device");
76 		goto fail;
77 	}
78 	if ((size_t)cnt != size) {
79 		ERROR(disk, "short read or read error from block device");
80 		goto fail;
81 	}
82 	if (p2 != data) {
83 		memcpy(data, p2, size);
84 		free(p2);
85 	}
86 	return (cnt);
87 fail:	memset(data, 0, size);
88 	if (p2 != data) {
89 		free(p2);
90 	}
91 	return (-1);
92 }
93 
94 ssize_t
95 bwrite(struct uufsd *disk, ufs2_daddr_t blockno, const void *data, size_t size)
96 {
97 	ssize_t cnt;
98 	int rv;
99 	void *p2 = NULL;
100 
101 	ERROR(disk, NULL);
102 
103 	rv = ufs_disk_write(disk);
104 	if (rv == -1) {
105 		ERROR(disk, "failed to open disk for writing");
106 		return (-1);
107 	}
108 
109 	/*
110 	 * XXX: various disk controllers require alignment of our buffer
111 	 * XXX: which is stricter than struct alignment.
112 	 * XXX: Bounce the buffer if not 64 byte aligned.
113 	 * XXX: this can be removed if/when the kernel is fixed
114 	 */
115 	if (((intptr_t)data) & 0x3f) {
116 		p2 = malloc(size);
117 		if (p2 == NULL)
118 			ERROR(disk, "allocate bounce buffer");
119 		memcpy(p2, data, size);
120 		data = p2;
121 	}
122 	cnt = pwrite(disk->d_fd, data, size, (off_t)(blockno * disk->d_bsize));
123 	if (p2 != NULL)
124 		free(p2);
125 	if (cnt == -1) {
126 		ERROR(disk, "write error to block device");
127 		return (-1);
128 	}
129 	if ((size_t)cnt != size) {
130 		ERROR(disk, "short write to block device");
131 		return (-1);
132 	}
133 
134 	return (cnt);
135 }
136