1/*	$NetBSD: rawfs.c,v 1.7 2006/06/25 17:36:07 tsutsui Exp $	*/
2
3/*
4 * Copyright (c) 1995 Gordon W. Ross
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28/*
29 * Raw file system - for stream devices like tapes.
30 * No random access, only sequential read allowed.
31 * This exists only to allow upper level code to be
32 * shielded from the fact that the device must be
33 * read only with whole block position and size.
34 */
35
36#include <sys/param.h>
37
38#include <lib/libsa/stand.h>
39#include <hp300/stand/common/rawfs.h>
40
41extern int debug;
42
43/* Our devices are generally willing to do 8K transfers. */
44#define	RAWFS_BSIZE	0x2000
45
46/*
47 * In-core open file.
48 */
49struct rawfs_file {
50	daddr_t		fs_nextblk;	/* block number to read next */
51	int		fs_len;		/* amount left in f_buf */
52	char *		fs_ptr;		/* read pointer into f_buf */
53	char		fs_buf[RAWFS_BSIZE];
54};
55
56static int rawfs_get_block(struct open_file *);
57
58int
59rawfs_open(const char *path, struct open_file *f)
60{
61	struct rawfs_file *fs;
62
63	/*
64	 * The actual tape driver has already been opened.
65	 * Just allocate the I/O buffer, etc.
66	 */
67	fs = alloc(sizeof(struct rawfs_file));
68	fs->fs_nextblk = 0;
69	fs->fs_len = 0;
70	fs->fs_ptr = fs->fs_buf;
71
72#ifdef	DEBUG_RAWFS
73	printf("rawfs_open: fs=0x%x\n", (u_long)fs);
74#endif
75
76	f->f_fsdata = fs;
77	return 0;
78}
79
80int
81rawfs_close(struct open_file *f)
82{
83	struct rawfs_file *fs;
84
85	fs = (struct rawfs_file *) f->f_fsdata;
86	f->f_fsdata = (void *)0;
87
88#ifdef	DEBUG_RAWFS
89	printf("rawfs_close: fs=0x%x\n", (u_long)fs);
90#endif
91
92	if (fs != (struct rawfs_file *)0)
93		dealloc(fs, sizeof(*fs));
94
95	return 0;
96}
97
98int
99rawfs_read(struct open_file *f, void *start, u_int size, u_int *resid)
100{
101	struct rawfs_file *fs = (struct rawfs_file *)f->f_fsdata;
102	char *addr = start;
103	int error = 0;
104	size_t csize;
105
106#ifdef DEBUG_RAWFS
107	printf("rawfs_read: file=0x%x, start=0x%x, size=%d, resid=0x%x\n",
108	    (u_long)f, (u_long)start, size, resid);
109	printf("            fs=0x%x\n", (u_long)fs);
110#endif
111
112	while (size != 0) {
113
114		if (fs->fs_len == 0)
115			if ((error = rawfs_get_block(f)) != 0)
116				break;
117
118		if (fs->fs_len <= 0)
119			break;	/* EOF */
120
121		csize = size;
122		if (csize > fs->fs_len)
123			csize = fs->fs_len;
124
125		memcpy(addr, fs->fs_ptr, csize);
126		fs->fs_ptr += csize;
127		fs->fs_len -= csize;
128		addr += csize;
129		size -= csize;
130	}
131	if (resid)
132		*resid = size;
133	return error;
134}
135
136int
137rawfs_write(struct open_file *f, void *start, size_t size, size_t *resid)
138{
139
140#ifdef	DEBUG_RAWFS
141	printf("rawfs_write: YOU'RE NOT SUPPOSED TO GET HERE!\n");
142#endif
143	return EROFS;
144}
145
146off_t
147rawfs_seek(struct open_file *f, off_t offset, int where)
148{
149
150#ifdef	DEBUG_RAWFS
151	printf("rawfs_seek: YOU'RE NOT SUPPOSED TO GET HERE!\n");
152#endif
153	return EFTYPE;
154}
155
156int
157rawfs_stat(struct open_file *f, struct stat *sb)
158{
159
160#ifdef	DEBUG_RAWFS
161	printf("rawfs_stat: I'll let you live only because of exec.c\n");
162#endif
163	/*
164	 * Clear out the stat buffer so that the uid check
165	 * won't fail.  See sys/lib/libsa/exec.c
166	 */
167	memset(sb, 0, sizeof(*sb));
168
169	return EFTYPE;
170}
171
172/*
173 * Read a block from the underlying stream device
174 * (In our case, a tape drive.)
175 */
176static int
177rawfs_get_block(struct open_file *f)
178{
179	struct rawfs_file *fs;
180	int error;
181	size_t len;
182
183	fs = (struct rawfs_file *)f->f_fsdata;
184	fs->fs_ptr = fs->fs_buf;
185
186	twiddle();
187#ifdef DEBUG_RAWFS
188	printf("rawfs_get_block: calling strategy\n");
189#endif
190	error = f->f_dev->dv_strategy(f->f_devdata, F_READ,
191		fs->fs_nextblk, RAWFS_BSIZE, fs->fs_buf, &len);
192#ifdef DEBUG_RAWFS
193	printf("rawfs_get_block: strategy returned %d\n", error);
194#endif
195
196	if (!error) {
197		fs->fs_len = len;
198		fs->fs_nextblk += (RAWFS_BSIZE / DEV_BSIZE);
199	}
200
201	return error;
202}
203