Annotation of sys/arch/hp300/stand/libsa/rawfs.c, Revision 1.1.1.1
1.1 nbrk 1: /* $OpenBSD: rawfs.c,v 1.4 2006/08/17 06:31:10 miod Exp $ */
2: /* $NetBSD: rawfs.c,v 1.2 1996/10/06 19:07:53 thorpej Exp $ */
3:
4: /*
5: * Copyright (c) 1995 Gordon W. Ross
6: * All rights reserved.
7: *
8: * Redistribution and use in source and binary forms, with or without
9: * modification, are permitted provided that the following conditions
10: * are met:
11: * 1. Redistributions of source code must retain the above copyright
12: * notice, this list of conditions and the following disclaimer.
13: * 2. Redistributions 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: * 3. The name of the author may not be used to endorse or promote products
17: * derived from this software without specific prior written permission.
18: * 4. All advertising materials mentioning features or use of this software
19: * must display the following acknowledgement:
20: * This product includes software developed by Gordon W. Ross
21: *
22: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32: */
33:
34: /*
35: * Raw file system - for stream devices like tapes.
36: * No random access, only sequential read allowed.
37: * This exists only to allow upper level code to be
38: * shielded from the fact that the device must be
39: * read only with whole block position and size.
40: */
41:
42: #include <sys/param.h>
43:
44: #include <lib/libsa/stand.h>
45: #include "rawfs.h"
46:
47: extern int debug;
48:
49: /* Our devices are generally willing to do 8K transfers. */
50: #define RAWFS_BSIZE 0x2000
51:
52: /*
53: * In-core open file.
54: */
55: struct rawfs_file {
56: daddr_t fs_nextblk; /* block number to read next */
57: int fs_len; /* amount left in f_buf */
58: char * fs_ptr; /* read pointer into f_buf */
59: char fs_buf[RAWFS_BSIZE];
60: };
61:
62: static int
63: rawfs_get_block(struct open_file *);
64:
65: int
66: rawfs_open(char *path, struct open_file *f)
67: {
68: struct rawfs_file *fs;
69:
70: /*
71: * The actual tape driver has already been opened.
72: * Just allocate the I/O buffer, etc.
73: */
74: fs = alloc(sizeof(struct rawfs_file));
75: fs->fs_nextblk = 0;
76: fs->fs_len = 0;
77: fs->fs_ptr = fs->fs_buf;
78:
79: #ifdef DEBUG_RAWFS
80: printf("rawfs_open: fs=0x%x\n", (u_long)fs);
81: #endif
82:
83: f->f_fsdata = fs;
84: return (0);
85: }
86:
87: int
88: rawfs_close(struct open_file *f)
89: {
90: struct rawfs_file *fs;
91:
92: fs = (struct rawfs_file *) f->f_fsdata;
93: f->f_fsdata = (void *)0;
94:
95: #ifdef DEBUG_RAWFS
96: printf("rawfs_close: fs=0x%x\n", (u_long)fs);
97: #endif
98:
99: if (fs != (struct rawfs_file *)0)
100: free(fs, sizeof(*fs));
101:
102: return (0);
103: }
104:
105: int
106: rawfs_read(struct open_file *f, void *start, size_t size, size_t *resid)
107: {
108: struct rawfs_file *fs = (struct rawfs_file *)f->f_fsdata;
109: char *addr = start;
110: int error = 0;
111: size_t csize;
112:
113: #ifdef DEBUG_RAWFS
114: printf("rawfs_read: file=0x%x, start=0x%x, size=%d, resid=0x%x\n",
115: (u_long)f, (u_long)start, size, resid);
116: printf(" fs=0x%x\n", (u_long)fs);
117: #endif
118:
119: while (size != 0) {
120:
121: if (fs->fs_len == 0)
122: if ((error = rawfs_get_block(f)) != 0)
123: break;
124:
125: if (fs->fs_len <= 0)
126: break; /* EOF */
127:
128: csize = size;
129: if (csize > fs->fs_len)
130: csize = fs->fs_len;
131:
132: bcopy(fs->fs_ptr, addr, csize);
133: fs->fs_ptr += csize;
134: fs->fs_len -= csize;
135: addr += csize;
136: size -= csize;
137: }
138: if (resid)
139: *resid = size;
140: return (error);
141: }
142:
143: int
144: rawfs_write(struct open_file *f, void *start, size_t size, size_t *resid)
145: {
146: #ifdef DEBUG_RAWFS
147: printf("rawfs_write: YOU'RE NOT SUPPOSED TO GET HERE!\n");
148: #endif
149: return (EROFS);
150: }
151:
152: off_t
153: rawfs_seek(struct open_file *f, off_t offset, int where)
154: {
155: #ifdef DEBUG_RAWFS
156: printf("rawfs_seek: YOU'RE NOT SUPPOSED TO GET HERE!\n");
157: #endif
158: return (EFTYPE);
159: }
160:
161: int
162: rawfs_stat(struct open_file *f, struct stat *sb)
163: {
164: #ifdef DEBUG_RAWFS
165: printf("rawfs_stat: I'll let you live only because of exec.c\n");
166: #endif
167: /*
168: * Clear out the stat buffer so that the uid check
169: * won't fail. See sys/lib/libsa/exec.c
170: */
171: bzero(sb, sizeof(*sb));
172:
173: return (EFTYPE);
174: }
175:
176: /*
177: * Read a block from the underlying stream device
178: * (In our case, a tape drive.)
179: */
180: static int
181: rawfs_get_block(struct open_file *f)
182: {
183: struct rawfs_file *fs;
184: size_t len;
185: int error;
186:
187: fs = (struct rawfs_file *)f->f_fsdata;
188: fs->fs_ptr = fs->fs_buf;
189:
190: twiddle();
191: #ifdef DEBUG_RAWFS
192: printf("rawfs_get_block: calling strategy\n");
193: #endif
194: error = f->f_dev->dv_strategy(f->f_devdata, F_READ,
195: fs->fs_nextblk, RAWFS_BSIZE, fs->fs_buf, &len);
196: #ifdef DEBUG_RAWFS
197: printf("rawfs_get_block: strategy returned %d\n", error);
198: #endif
199:
200: if (!error) {
201: fs->fs_len = len;
202: fs->fs_nextblk += (RAWFS_BSIZE / DEV_BSIZE);
203: }
204:
205: return (error);
206: }
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